1 //===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements semantic analysis for C++ declarations.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ASTLambda.h"
16 #include "clang/AST/ASTMutationListener.h"
17 #include "clang/AST/CXXInheritance.h"
18 #include "clang/AST/CharUnits.h"
19 #include "clang/AST/ComparisonCategories.h"
20 #include "clang/AST/EvaluatedExprVisitor.h"
21 #include "clang/AST/ExprCXX.h"
22 #include "clang/AST/RecordLayout.h"
23 #include "clang/AST/RecursiveASTVisitor.h"
24 #include "clang/AST/StmtVisitor.h"
25 #include "clang/AST/TypeLoc.h"
26 #include "clang/AST/TypeOrdering.h"
27 #include "clang/Basic/AttributeCommonInfo.h"
28 #include "clang/Basic/PartialDiagnostic.h"
29 #include "clang/Basic/TargetInfo.h"
30 #include "clang/Lex/LiteralSupport.h"
31 #include "clang/Lex/Preprocessor.h"
32 #include "clang/Sema/CXXFieldCollector.h"
33 #include "clang/Sema/DeclSpec.h"
34 #include "clang/Sema/Initialization.h"
35 #include "clang/Sema/Lookup.h"
36 #include "clang/Sema/ParsedTemplate.h"
37 #include "clang/Sema/Scope.h"
38 #include "clang/Sema/ScopeInfo.h"
39 #include "clang/Sema/SemaInternal.h"
40 #include "clang/Sema/Template.h"
41 #include "llvm/ADT/ScopeExit.h"
42 #include "llvm/ADT/SmallString.h"
43 #include "llvm/ADT/STLExtras.h"
44 #include "llvm/ADT/StringExtras.h"
45 #include <map>
46 #include <set>
47
48 using namespace clang;
49
50 //===----------------------------------------------------------------------===//
51 // CheckDefaultArgumentVisitor
52 //===----------------------------------------------------------------------===//
53
54 namespace {
55 /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
56 /// the default argument of a parameter to determine whether it
57 /// contains any ill-formed subexpressions. For example, this will
58 /// diagnose the use of local variables or parameters within the
59 /// default argument expression.
60 class CheckDefaultArgumentVisitor
61 : public ConstStmtVisitor<CheckDefaultArgumentVisitor, bool> {
62 Sema &S;
63 const Expr *DefaultArg;
64
65 public:
CheckDefaultArgumentVisitor(Sema & S,const Expr * DefaultArg)66 CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg)
67 : S(S), DefaultArg(DefaultArg) {}
68
69 bool VisitExpr(const Expr *Node);
70 bool VisitDeclRefExpr(const DeclRefExpr *DRE);
71 bool VisitCXXThisExpr(const CXXThisExpr *ThisE);
72 bool VisitLambdaExpr(const LambdaExpr *Lambda);
73 bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE);
74 };
75
76 /// VisitExpr - Visit all of the children of this expression.
VisitExpr(const Expr * Node)77 bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) {
78 bool IsInvalid = false;
79 for (const Stmt *SubStmt : Node->children())
80 IsInvalid |= Visit(SubStmt);
81 return IsInvalid;
82 }
83
84 /// VisitDeclRefExpr - Visit a reference to a declaration, to
85 /// determine whether this declaration can be used in the default
86 /// argument expression.
VisitDeclRefExpr(const DeclRefExpr * DRE)87 bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) {
88 const NamedDecl *Decl = DRE->getDecl();
89 if (const auto *Param = dyn_cast<ParmVarDecl>(Decl)) {
90 // C++ [dcl.fct.default]p9:
91 // [...] parameters of a function shall not be used in default
92 // argument expressions, even if they are not evaluated. [...]
93 //
94 // C++17 [dcl.fct.default]p9 (by CWG 2082):
95 // [...] A parameter shall not appear as a potentially-evaluated
96 // expression in a default argument. [...]
97 //
98 if (DRE->isNonOdrUse() != NOUR_Unevaluated)
99 return S.Diag(DRE->getBeginLoc(),
100 diag::err_param_default_argument_references_param)
101 << Param->getDeclName() << DefaultArg->getSourceRange();
102 } else if (const auto *VDecl = dyn_cast<VarDecl>(Decl)) {
103 // C++ [dcl.fct.default]p7:
104 // Local variables shall not be used in default argument
105 // expressions.
106 //
107 // C++17 [dcl.fct.default]p7 (by CWG 2082):
108 // A local variable shall not appear as a potentially-evaluated
109 // expression in a default argument.
110 //
111 // C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346):
112 // Note: A local variable cannot be odr-used (6.3) in a default argument.
113 //
114 if (VDecl->isLocalVarDecl() && !DRE->isNonOdrUse())
115 return S.Diag(DRE->getBeginLoc(),
116 diag::err_param_default_argument_references_local)
117 << VDecl->getDeclName() << DefaultArg->getSourceRange();
118 }
119
120 return false;
121 }
122
123 /// VisitCXXThisExpr - Visit a C++ "this" expression.
VisitCXXThisExpr(const CXXThisExpr * ThisE)124 bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) {
125 // C++ [dcl.fct.default]p8:
126 // The keyword this shall not be used in a default argument of a
127 // member function.
128 return S.Diag(ThisE->getBeginLoc(),
129 diag::err_param_default_argument_references_this)
130 << ThisE->getSourceRange();
131 }
132
VisitPseudoObjectExpr(const PseudoObjectExpr * POE)133 bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(
134 const PseudoObjectExpr *POE) {
135 bool Invalid = false;
136 for (const Expr *E : POE->semantics()) {
137 // Look through bindings.
138 if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) {
139 E = OVE->getSourceExpr();
140 assert(E && "pseudo-object binding without source expression?");
141 }
142
143 Invalid |= Visit(E);
144 }
145 return Invalid;
146 }
147
VisitLambdaExpr(const LambdaExpr * Lambda)148 bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) {
149 // C++11 [expr.lambda.prim]p13:
150 // A lambda-expression appearing in a default argument shall not
151 // implicitly or explicitly capture any entity.
152 if (Lambda->capture_begin() == Lambda->capture_end())
153 return false;
154
155 return S.Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
156 }
157 } // namespace
158
159 void
CalledDecl(SourceLocation CallLoc,const CXXMethodDecl * Method)160 Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
161 const CXXMethodDecl *Method) {
162 // If we have an MSAny spec already, don't bother.
163 if (!Method || ComputedEST == EST_MSAny)
164 return;
165
166 const FunctionProtoType *Proto
167 = Method->getType()->getAs<FunctionProtoType>();
168 Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
169 if (!Proto)
170 return;
171
172 ExceptionSpecificationType EST = Proto->getExceptionSpecType();
173
174 // If we have a throw-all spec at this point, ignore the function.
175 if (ComputedEST == EST_None)
176 return;
177
178 if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
179 EST = EST_BasicNoexcept;
180
181 switch (EST) {
182 case EST_Unparsed:
183 case EST_Uninstantiated:
184 case EST_Unevaluated:
185 llvm_unreachable("should not see unresolved exception specs here");
186
187 // If this function can throw any exceptions, make a note of that.
188 case EST_MSAny:
189 case EST_None:
190 // FIXME: Whichever we see last of MSAny and None determines our result.
191 // We should make a consistent, order-independent choice here.
192 ClearExceptions();
193 ComputedEST = EST;
194 return;
195 case EST_NoexceptFalse:
196 ClearExceptions();
197 ComputedEST = EST_None;
198 return;
199 // FIXME: If the call to this decl is using any of its default arguments, we
200 // need to search them for potentially-throwing calls.
201 // If this function has a basic noexcept, it doesn't affect the outcome.
202 case EST_BasicNoexcept:
203 case EST_NoexceptTrue:
204 case EST_NoThrow:
205 return;
206 // If we're still at noexcept(true) and there's a throw() callee,
207 // change to that specification.
208 case EST_DynamicNone:
209 if (ComputedEST == EST_BasicNoexcept)
210 ComputedEST = EST_DynamicNone;
211 return;
212 case EST_DependentNoexcept:
213 llvm_unreachable(
214 "should not generate implicit declarations for dependent cases");
215 case EST_Dynamic:
216 break;
217 }
218 assert(EST == EST_Dynamic && "EST case not considered earlier.");
219 assert(ComputedEST != EST_None &&
220 "Shouldn't collect exceptions when throw-all is guaranteed.");
221 ComputedEST = EST_Dynamic;
222 // Record the exceptions in this function's exception specification.
223 for (const auto &E : Proto->exceptions())
224 if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
225 Exceptions.push_back(E);
226 }
227
CalledStmt(Stmt * S)228 void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
229 if (!S || ComputedEST == EST_MSAny)
230 return;
231
232 // FIXME:
233 //
234 // C++0x [except.spec]p14:
235 // [An] implicit exception-specification specifies the type-id T if and
236 // only if T is allowed by the exception-specification of a function directly
237 // invoked by f's implicit definition; f shall allow all exceptions if any
238 // function it directly invokes allows all exceptions, and f shall allow no
239 // exceptions if every function it directly invokes allows no exceptions.
240 //
241 // Note in particular that if an implicit exception-specification is generated
242 // for a function containing a throw-expression, that specification can still
243 // be noexcept(true).
244 //
245 // Note also that 'directly invoked' is not defined in the standard, and there
246 // is no indication that we should only consider potentially-evaluated calls.
247 //
248 // Ultimately we should implement the intent of the standard: the exception
249 // specification should be the set of exceptions which can be thrown by the
250 // implicit definition. For now, we assume that any non-nothrow expression can
251 // throw any exception.
252
253 if (Self->canThrow(S))
254 ComputedEST = EST_None;
255 }
256
ConvertParamDefaultArgument(ParmVarDecl * Param,Expr * Arg,SourceLocation EqualLoc)257 ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
258 SourceLocation EqualLoc) {
259 if (RequireCompleteType(Param->getLocation(), Param->getType(),
260 diag::err_typecheck_decl_incomplete_type))
261 return true;
262
263 // C++ [dcl.fct.default]p5
264 // A default argument expression is implicitly converted (clause
265 // 4) to the parameter type. The default argument expression has
266 // the same semantic constraints as the initializer expression in
267 // a declaration of a variable of the parameter type, using the
268 // copy-initialization semantics (8.5).
269 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
270 Param);
271 InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
272 EqualLoc);
273 InitializationSequence InitSeq(*this, Entity, Kind, Arg);
274 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
275 if (Result.isInvalid())
276 return true;
277 Arg = Result.getAs<Expr>();
278
279 CheckCompletedExpr(Arg, EqualLoc);
280 Arg = MaybeCreateExprWithCleanups(Arg);
281
282 return Arg;
283 }
284
SetParamDefaultArgument(ParmVarDecl * Param,Expr * Arg,SourceLocation EqualLoc)285 void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
286 SourceLocation EqualLoc) {
287 // Add the default argument to the parameter
288 Param->setDefaultArg(Arg);
289
290 // We have already instantiated this parameter; provide each of the
291 // instantiations with the uninstantiated default argument.
292 UnparsedDefaultArgInstantiationsMap::iterator InstPos
293 = UnparsedDefaultArgInstantiations.find(Param);
294 if (InstPos != UnparsedDefaultArgInstantiations.end()) {
295 for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
296 InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
297
298 // We're done tracking this parameter's instantiations.
299 UnparsedDefaultArgInstantiations.erase(InstPos);
300 }
301 }
302
303 /// ActOnParamDefaultArgument - Check whether the default argument
304 /// provided for a function parameter is well-formed. If so, attach it
305 /// to the parameter declaration.
306 void
ActOnParamDefaultArgument(Decl * param,SourceLocation EqualLoc,Expr * DefaultArg)307 Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
308 Expr *DefaultArg) {
309 if (!param || !DefaultArg)
310 return;
311
312 ParmVarDecl *Param = cast<ParmVarDecl>(param);
313 UnparsedDefaultArgLocs.erase(Param);
314
315 auto Fail = [&] {
316 Param->setInvalidDecl();
317 Param->setDefaultArg(new (Context) OpaqueValueExpr(
318 EqualLoc, Param->getType().getNonReferenceType(), VK_RValue));
319 };
320
321 // Default arguments are only permitted in C++
322 if (!getLangOpts().CPlusPlus) {
323 Diag(EqualLoc, diag::err_param_default_argument)
324 << DefaultArg->getSourceRange();
325 return Fail();
326 }
327
328 // Check for unexpanded parameter packs.
329 if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
330 return Fail();
331 }
332
333 // C++11 [dcl.fct.default]p3
334 // A default argument expression [...] shall not be specified for a
335 // parameter pack.
336 if (Param->isParameterPack()) {
337 Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
338 << DefaultArg->getSourceRange();
339 // Recover by discarding the default argument.
340 Param->setDefaultArg(nullptr);
341 return;
342 }
343
344 ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc);
345 if (Result.isInvalid())
346 return Fail();
347
348 DefaultArg = Result.getAs<Expr>();
349
350 // Check that the default argument is well-formed
351 CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg);
352 if (DefaultArgChecker.Visit(DefaultArg))
353 return Fail();
354
355 SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
356 }
357
358 /// ActOnParamUnparsedDefaultArgument - We've seen a default
359 /// argument for a function parameter, but we can't parse it yet
360 /// because we're inside a class definition. Note that this default
361 /// argument will be parsed later.
ActOnParamUnparsedDefaultArgument(Decl * param,SourceLocation EqualLoc,SourceLocation ArgLoc)362 void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
363 SourceLocation EqualLoc,
364 SourceLocation ArgLoc) {
365 if (!param)
366 return;
367
368 ParmVarDecl *Param = cast<ParmVarDecl>(param);
369 Param->setUnparsedDefaultArg();
370 UnparsedDefaultArgLocs[Param] = ArgLoc;
371 }
372
373 /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
374 /// the default argument for the parameter param failed.
ActOnParamDefaultArgumentError(Decl * param,SourceLocation EqualLoc)375 void Sema::ActOnParamDefaultArgumentError(Decl *param,
376 SourceLocation EqualLoc) {
377 if (!param)
378 return;
379
380 ParmVarDecl *Param = cast<ParmVarDecl>(param);
381 Param->setInvalidDecl();
382 UnparsedDefaultArgLocs.erase(Param);
383 Param->setDefaultArg(new(Context)
384 OpaqueValueExpr(EqualLoc,
385 Param->getType().getNonReferenceType(),
386 VK_RValue));
387 }
388
389 /// CheckExtraCXXDefaultArguments - Check for any extra default
390 /// arguments in the declarator, which is not a function declaration
391 /// or definition and therefore is not permitted to have default
392 /// arguments. This routine should be invoked for every declarator
393 /// that is not a function declaration or definition.
CheckExtraCXXDefaultArguments(Declarator & D)394 void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
395 // C++ [dcl.fct.default]p3
396 // A default argument expression shall be specified only in the
397 // parameter-declaration-clause of a function declaration or in a
398 // template-parameter (14.1). It shall not be specified for a
399 // parameter pack. If it is specified in a
400 // parameter-declaration-clause, it shall not occur within a
401 // declarator or abstract-declarator of a parameter-declaration.
402 bool MightBeFunction = D.isFunctionDeclarationContext();
403 for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
404 DeclaratorChunk &chunk = D.getTypeObject(i);
405 if (chunk.Kind == DeclaratorChunk::Function) {
406 if (MightBeFunction) {
407 // This is a function declaration. It can have default arguments, but
408 // keep looking in case its return type is a function type with default
409 // arguments.
410 MightBeFunction = false;
411 continue;
412 }
413 for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
414 ++argIdx) {
415 ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
416 if (Param->hasUnparsedDefaultArg()) {
417 std::unique_ptr<CachedTokens> Toks =
418 std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
419 SourceRange SR;
420 if (Toks->size() > 1)
421 SR = SourceRange((*Toks)[1].getLocation(),
422 Toks->back().getLocation());
423 else
424 SR = UnparsedDefaultArgLocs[Param];
425 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
426 << SR;
427 } else if (Param->getDefaultArg()) {
428 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
429 << Param->getDefaultArg()->getSourceRange();
430 Param->setDefaultArg(nullptr);
431 }
432 }
433 } else if (chunk.Kind != DeclaratorChunk::Paren) {
434 MightBeFunction = false;
435 }
436 }
437 }
438
functionDeclHasDefaultArgument(const FunctionDecl * FD)439 static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
440 return std::any_of(FD->param_begin(), FD->param_end(), [](ParmVarDecl *P) {
441 return P->hasDefaultArg() && !P->hasInheritedDefaultArg();
442 });
443 }
444
445 /// MergeCXXFunctionDecl - Merge two declarations of the same C++
446 /// function, once we already know that they have the same
447 /// type. Subroutine of MergeFunctionDecl. Returns true if there was an
448 /// error, false otherwise.
MergeCXXFunctionDecl(FunctionDecl * New,FunctionDecl * Old,Scope * S)449 bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
450 Scope *S) {
451 bool Invalid = false;
452
453 // The declaration context corresponding to the scope is the semantic
454 // parent, unless this is a local function declaration, in which case
455 // it is that surrounding function.
456 DeclContext *ScopeDC = New->isLocalExternDecl()
457 ? New->getLexicalDeclContext()
458 : New->getDeclContext();
459
460 // Find the previous declaration for the purpose of default arguments.
461 FunctionDecl *PrevForDefaultArgs = Old;
462 for (/**/; PrevForDefaultArgs;
463 // Don't bother looking back past the latest decl if this is a local
464 // extern declaration; nothing else could work.
465 PrevForDefaultArgs = New->isLocalExternDecl()
466 ? nullptr
467 : PrevForDefaultArgs->getPreviousDecl()) {
468 // Ignore hidden declarations.
469 if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
470 continue;
471
472 if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
473 !New->isCXXClassMember()) {
474 // Ignore default arguments of old decl if they are not in
475 // the same scope and this is not an out-of-line definition of
476 // a member function.
477 continue;
478 }
479
480 if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
481 // If only one of these is a local function declaration, then they are
482 // declared in different scopes, even though isDeclInScope may think
483 // they're in the same scope. (If both are local, the scope check is
484 // sufficient, and if neither is local, then they are in the same scope.)
485 continue;
486 }
487
488 // We found the right previous declaration.
489 break;
490 }
491
492 // C++ [dcl.fct.default]p4:
493 // For non-template functions, default arguments can be added in
494 // later declarations of a function in the same
495 // scope. Declarations in different scopes have completely
496 // distinct sets of default arguments. That is, declarations in
497 // inner scopes do not acquire default arguments from
498 // declarations in outer scopes, and vice versa. In a given
499 // function declaration, all parameters subsequent to a
500 // parameter with a default argument shall have default
501 // arguments supplied in this or previous declarations. A
502 // default argument shall not be redefined by a later
503 // declaration (not even to the same value).
504 //
505 // C++ [dcl.fct.default]p6:
506 // Except for member functions of class templates, the default arguments
507 // in a member function definition that appears outside of the class
508 // definition are added to the set of default arguments provided by the
509 // member function declaration in the class definition.
510 for (unsigned p = 0, NumParams = PrevForDefaultArgs
511 ? PrevForDefaultArgs->getNumParams()
512 : 0;
513 p < NumParams; ++p) {
514 ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
515 ParmVarDecl *NewParam = New->getParamDecl(p);
516
517 bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
518 bool NewParamHasDfl = NewParam->hasDefaultArg();
519
520 if (OldParamHasDfl && NewParamHasDfl) {
521 unsigned DiagDefaultParamID =
522 diag::err_param_default_argument_redefinition;
523
524 // MSVC accepts that default parameters be redefined for member functions
525 // of template class. The new default parameter's value is ignored.
526 Invalid = true;
527 if (getLangOpts().MicrosoftExt) {
528 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
529 if (MD && MD->getParent()->getDescribedClassTemplate()) {
530 // Merge the old default argument into the new parameter.
531 NewParam->setHasInheritedDefaultArg();
532 if (OldParam->hasUninstantiatedDefaultArg())
533 NewParam->setUninstantiatedDefaultArg(
534 OldParam->getUninstantiatedDefaultArg());
535 else
536 NewParam->setDefaultArg(OldParam->getInit());
537 DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
538 Invalid = false;
539 }
540 }
541
542 // FIXME: If we knew where the '=' was, we could easily provide a fix-it
543 // hint here. Alternatively, we could walk the type-source information
544 // for NewParam to find the last source location in the type... but it
545 // isn't worth the effort right now. This is the kind of test case that
546 // is hard to get right:
547 // int f(int);
548 // void g(int (*fp)(int) = f);
549 // void g(int (*fp)(int) = &f);
550 Diag(NewParam->getLocation(), DiagDefaultParamID)
551 << NewParam->getDefaultArgRange();
552
553 // Look for the function declaration where the default argument was
554 // actually written, which may be a declaration prior to Old.
555 for (auto Older = PrevForDefaultArgs;
556 OldParam->hasInheritedDefaultArg(); /**/) {
557 Older = Older->getPreviousDecl();
558 OldParam = Older->getParamDecl(p);
559 }
560
561 Diag(OldParam->getLocation(), diag::note_previous_definition)
562 << OldParam->getDefaultArgRange();
563 } else if (OldParamHasDfl) {
564 // Merge the old default argument into the new parameter unless the new
565 // function is a friend declaration in a template class. In the latter
566 // case the default arguments will be inherited when the friend
567 // declaration will be instantiated.
568 if (New->getFriendObjectKind() == Decl::FOK_None ||
569 !New->getLexicalDeclContext()->isDependentContext()) {
570 // It's important to use getInit() here; getDefaultArg()
571 // strips off any top-level ExprWithCleanups.
572 NewParam->setHasInheritedDefaultArg();
573 if (OldParam->hasUnparsedDefaultArg())
574 NewParam->setUnparsedDefaultArg();
575 else if (OldParam->hasUninstantiatedDefaultArg())
576 NewParam->setUninstantiatedDefaultArg(
577 OldParam->getUninstantiatedDefaultArg());
578 else
579 NewParam->setDefaultArg(OldParam->getInit());
580 }
581 } else if (NewParamHasDfl) {
582 if (New->getDescribedFunctionTemplate()) {
583 // Paragraph 4, quoted above, only applies to non-template functions.
584 Diag(NewParam->getLocation(),
585 diag::err_param_default_argument_template_redecl)
586 << NewParam->getDefaultArgRange();
587 Diag(PrevForDefaultArgs->getLocation(),
588 diag::note_template_prev_declaration)
589 << false;
590 } else if (New->getTemplateSpecializationKind()
591 != TSK_ImplicitInstantiation &&
592 New->getTemplateSpecializationKind() != TSK_Undeclared) {
593 // C++ [temp.expr.spec]p21:
594 // Default function arguments shall not be specified in a declaration
595 // or a definition for one of the following explicit specializations:
596 // - the explicit specialization of a function template;
597 // - the explicit specialization of a member function template;
598 // - the explicit specialization of a member function of a class
599 // template where the class template specialization to which the
600 // member function specialization belongs is implicitly
601 // instantiated.
602 Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
603 << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
604 << New->getDeclName()
605 << NewParam->getDefaultArgRange();
606 } else if (New->getDeclContext()->isDependentContext()) {
607 // C++ [dcl.fct.default]p6 (DR217):
608 // Default arguments for a member function of a class template shall
609 // be specified on the initial declaration of the member function
610 // within the class template.
611 //
612 // Reading the tea leaves a bit in DR217 and its reference to DR205
613 // leads me to the conclusion that one cannot add default function
614 // arguments for an out-of-line definition of a member function of a
615 // dependent type.
616 int WhichKind = 2;
617 if (CXXRecordDecl *Record
618 = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
619 if (Record->getDescribedClassTemplate())
620 WhichKind = 0;
621 else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
622 WhichKind = 1;
623 else
624 WhichKind = 2;
625 }
626
627 Diag(NewParam->getLocation(),
628 diag::err_param_default_argument_member_template_redecl)
629 << WhichKind
630 << NewParam->getDefaultArgRange();
631 }
632 }
633 }
634
635 // DR1344: If a default argument is added outside a class definition and that
636 // default argument makes the function a special member function, the program
637 // is ill-formed. This can only happen for constructors.
638 if (isa<CXXConstructorDecl>(New) &&
639 New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
640 CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
641 OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
642 if (NewSM != OldSM) {
643 ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
644 assert(NewParam->hasDefaultArg());
645 Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
646 << NewParam->getDefaultArgRange() << NewSM;
647 Diag(Old->getLocation(), diag::note_previous_declaration);
648 }
649 }
650
651 const FunctionDecl *Def;
652 // C++11 [dcl.constexpr]p1: If any declaration of a function or function
653 // template has a constexpr specifier then all its declarations shall
654 // contain the constexpr specifier.
655 if (New->getConstexprKind() != Old->getConstexprKind()) {
656 Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
657 << New << static_cast<int>(New->getConstexprKind())
658 << static_cast<int>(Old->getConstexprKind());
659 Diag(Old->getLocation(), diag::note_previous_declaration);
660 Invalid = true;
661 } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
662 Old->isDefined(Def) &&
663 // If a friend function is inlined but does not have 'inline'
664 // specifier, it is a definition. Do not report attribute conflict
665 // in this case, redefinition will be diagnosed later.
666 (New->isInlineSpecified() ||
667 New->getFriendObjectKind() == Decl::FOK_None)) {
668 // C++11 [dcl.fcn.spec]p4:
669 // If the definition of a function appears in a translation unit before its
670 // first declaration as inline, the program is ill-formed.
671 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
672 Diag(Def->getLocation(), diag::note_previous_definition);
673 Invalid = true;
674 }
675
676 // C++17 [temp.deduct.guide]p3:
677 // Two deduction guide declarations in the same translation unit
678 // for the same class template shall not have equivalent
679 // parameter-declaration-clauses.
680 if (isa<CXXDeductionGuideDecl>(New) &&
681 !New->isFunctionTemplateSpecialization() && isVisible(Old)) {
682 Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
683 Diag(Old->getLocation(), diag::note_previous_declaration);
684 }
685
686 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
687 // argument expression, that declaration shall be a definition and shall be
688 // the only declaration of the function or function template in the
689 // translation unit.
690 if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
691 functionDeclHasDefaultArgument(Old)) {
692 Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
693 Diag(Old->getLocation(), diag::note_previous_declaration);
694 Invalid = true;
695 }
696
697 // C++11 [temp.friend]p4 (DR329):
698 // When a function is defined in a friend function declaration in a class
699 // template, the function is instantiated when the function is odr-used.
700 // The same restrictions on multiple declarations and definitions that
701 // apply to non-template function declarations and definitions also apply
702 // to these implicit definitions.
703 const FunctionDecl *OldDefinition = nullptr;
704 if (New->isThisDeclarationInstantiatedFromAFriendDefinition() &&
705 Old->isDefined(OldDefinition, true))
706 CheckForFunctionRedefinition(New, OldDefinition);
707
708 return Invalid;
709 }
710
711 NamedDecl *
ActOnDecompositionDeclarator(Scope * S,Declarator & D,MultiTemplateParamsArg TemplateParamLists)712 Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
713 MultiTemplateParamsArg TemplateParamLists) {
714 assert(D.isDecompositionDeclarator());
715 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
716
717 // The syntax only allows a decomposition declarator as a simple-declaration,
718 // a for-range-declaration, or a condition in Clang, but we parse it in more
719 // cases than that.
720 if (!D.mayHaveDecompositionDeclarator()) {
721 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
722 << Decomp.getSourceRange();
723 return nullptr;
724 }
725
726 if (!TemplateParamLists.empty()) {
727 // FIXME: There's no rule against this, but there are also no rules that
728 // would actually make it usable, so we reject it for now.
729 Diag(TemplateParamLists.front()->getTemplateLoc(),
730 diag::err_decomp_decl_template);
731 return nullptr;
732 }
733
734 Diag(Decomp.getLSquareLoc(),
735 !getLangOpts().CPlusPlus17
736 ? diag::ext_decomp_decl
737 : D.getContext() == DeclaratorContext::Condition
738 ? diag::ext_decomp_decl_cond
739 : diag::warn_cxx14_compat_decomp_decl)
740 << Decomp.getSourceRange();
741
742 // The semantic context is always just the current context.
743 DeclContext *const DC = CurContext;
744
745 // C++17 [dcl.dcl]/8:
746 // The decl-specifier-seq shall contain only the type-specifier auto
747 // and cv-qualifiers.
748 // C++2a [dcl.dcl]/8:
749 // If decl-specifier-seq contains any decl-specifier other than static,
750 // thread_local, auto, or cv-qualifiers, the program is ill-formed.
751 auto &DS = D.getDeclSpec();
752 {
753 SmallVector<StringRef, 8> BadSpecifiers;
754 SmallVector<SourceLocation, 8> BadSpecifierLocs;
755 SmallVector<StringRef, 8> CPlusPlus20Specifiers;
756 SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
757 if (auto SCS = DS.getStorageClassSpec()) {
758 if (SCS == DeclSpec::SCS_static) {
759 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
760 CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
761 } else {
762 BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
763 BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
764 }
765 }
766 if (auto TSCS = DS.getThreadStorageClassSpec()) {
767 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
768 CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
769 }
770 if (DS.hasConstexprSpecifier()) {
771 BadSpecifiers.push_back(
772 DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
773 BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
774 }
775 if (DS.isInlineSpecified()) {
776 BadSpecifiers.push_back("inline");
777 BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
778 }
779 if (!BadSpecifiers.empty()) {
780 auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
781 Err << (int)BadSpecifiers.size()
782 << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
783 // Don't add FixItHints to remove the specifiers; we do still respect
784 // them when building the underlying variable.
785 for (auto Loc : BadSpecifierLocs)
786 Err << SourceRange(Loc, Loc);
787 } else if (!CPlusPlus20Specifiers.empty()) {
788 auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
789 getLangOpts().CPlusPlus20
790 ? diag::warn_cxx17_compat_decomp_decl_spec
791 : diag::ext_decomp_decl_spec);
792 Warn << (int)CPlusPlus20Specifiers.size()
793 << llvm::join(CPlusPlus20Specifiers.begin(),
794 CPlusPlus20Specifiers.end(), " ");
795 for (auto Loc : CPlusPlus20SpecifierLocs)
796 Warn << SourceRange(Loc, Loc);
797 }
798 // We can't recover from it being declared as a typedef.
799 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
800 return nullptr;
801 }
802
803 // C++2a [dcl.struct.bind]p1:
804 // A cv that includes volatile is deprecated
805 if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
806 getLangOpts().CPlusPlus20)
807 Diag(DS.getVolatileSpecLoc(),
808 diag::warn_deprecated_volatile_structured_binding);
809
810 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
811 QualType R = TInfo->getType();
812
813 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
814 UPPC_DeclarationType))
815 D.setInvalidType();
816
817 // The syntax only allows a single ref-qualifier prior to the decomposition
818 // declarator. No other declarator chunks are permitted. Also check the type
819 // specifier here.
820 if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
821 D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
822 (D.getNumTypeObjects() == 1 &&
823 D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
824 Diag(Decomp.getLSquareLoc(),
825 (D.hasGroupingParens() ||
826 (D.getNumTypeObjects() &&
827 D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
828 ? diag::err_decomp_decl_parens
829 : diag::err_decomp_decl_type)
830 << R;
831
832 // In most cases, there's no actual problem with an explicitly-specified
833 // type, but a function type won't work here, and ActOnVariableDeclarator
834 // shouldn't be called for such a type.
835 if (R->isFunctionType())
836 D.setInvalidType();
837 }
838
839 // Build the BindingDecls.
840 SmallVector<BindingDecl*, 8> Bindings;
841
842 // Build the BindingDecls.
843 for (auto &B : D.getDecompositionDeclarator().bindings()) {
844 // Check for name conflicts.
845 DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
846 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
847 ForVisibleRedeclaration);
848 LookupName(Previous, S,
849 /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
850
851 // It's not permitted to shadow a template parameter name.
852 if (Previous.isSingleResult() &&
853 Previous.getFoundDecl()->isTemplateParameter()) {
854 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
855 Previous.getFoundDecl());
856 Previous.clear();
857 }
858
859 auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
860
861 // Find the shadowed declaration before filtering for scope.
862 NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
863 ? getShadowedDeclaration(BD, Previous)
864 : nullptr;
865
866 bool ConsiderLinkage = DC->isFunctionOrMethod() &&
867 DS.getStorageClassSpec() == DeclSpec::SCS_extern;
868 FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
869 /*AllowInlineNamespace*/false);
870
871 if (!Previous.empty()) {
872 auto *Old = Previous.getRepresentativeDecl();
873 Diag(B.NameLoc, diag::err_redefinition) << B.Name;
874 Diag(Old->getLocation(), diag::note_previous_definition);
875 } else if (ShadowedDecl && !D.isRedeclaration()) {
876 CheckShadow(BD, ShadowedDecl, Previous);
877 }
878 PushOnScopeChains(BD, S, true);
879 Bindings.push_back(BD);
880 ParsingInitForAutoVars.insert(BD);
881 }
882
883 // There are no prior lookup results for the variable itself, because it
884 // is unnamed.
885 DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
886 Decomp.getLSquareLoc());
887 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
888 ForVisibleRedeclaration);
889
890 // Build the variable that holds the non-decomposed object.
891 bool AddToScope = true;
892 NamedDecl *New =
893 ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
894 MultiTemplateParamsArg(), AddToScope, Bindings);
895 if (AddToScope) {
896 S->AddDecl(New);
897 CurContext->addHiddenDecl(New);
898 }
899
900 if (isInOpenMPDeclareTargetContext())
901 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
902
903 return New;
904 }
905
checkSimpleDecomposition(Sema & S,ArrayRef<BindingDecl * > Bindings,ValueDecl * Src,QualType DecompType,const llvm::APSInt & NumElems,QualType ElemType,llvm::function_ref<ExprResult (SourceLocation,Expr *,unsigned)> GetInit)906 static bool checkSimpleDecomposition(
907 Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
908 QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
909 llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
910 if ((int64_t)Bindings.size() != NumElems) {
911 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
912 << DecompType << (unsigned)Bindings.size()
913 << (unsigned)NumElems.getLimitedValue(UINT_MAX) << NumElems.toString(10)
914 << (NumElems < Bindings.size());
915 return true;
916 }
917
918 unsigned I = 0;
919 for (auto *B : Bindings) {
920 SourceLocation Loc = B->getLocation();
921 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
922 if (E.isInvalid())
923 return true;
924 E = GetInit(Loc, E.get(), I++);
925 if (E.isInvalid())
926 return true;
927 B->setBinding(ElemType, E.get());
928 }
929
930 return false;
931 }
932
checkArrayLikeDecomposition(Sema & S,ArrayRef<BindingDecl * > Bindings,ValueDecl * Src,QualType DecompType,const llvm::APSInt & NumElems,QualType ElemType)933 static bool checkArrayLikeDecomposition(Sema &S,
934 ArrayRef<BindingDecl *> Bindings,
935 ValueDecl *Src, QualType DecompType,
936 const llvm::APSInt &NumElems,
937 QualType ElemType) {
938 return checkSimpleDecomposition(
939 S, Bindings, Src, DecompType, NumElems, ElemType,
940 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
941 ExprResult E = S.ActOnIntegerConstant(Loc, I);
942 if (E.isInvalid())
943 return ExprError();
944 return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
945 });
946 }
947
checkArrayDecomposition(Sema & S,ArrayRef<BindingDecl * > Bindings,ValueDecl * Src,QualType DecompType,const ConstantArrayType * CAT)948 static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
949 ValueDecl *Src, QualType DecompType,
950 const ConstantArrayType *CAT) {
951 return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
952 llvm::APSInt(CAT->getSize()),
953 CAT->getElementType());
954 }
955
checkVectorDecomposition(Sema & S,ArrayRef<BindingDecl * > Bindings,ValueDecl * Src,QualType DecompType,const VectorType * VT)956 static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
957 ValueDecl *Src, QualType DecompType,
958 const VectorType *VT) {
959 return checkArrayLikeDecomposition(
960 S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
961 S.Context.getQualifiedType(VT->getElementType(),
962 DecompType.getQualifiers()));
963 }
964
checkComplexDecomposition(Sema & S,ArrayRef<BindingDecl * > Bindings,ValueDecl * Src,QualType DecompType,const ComplexType * CT)965 static bool checkComplexDecomposition(Sema &S,
966 ArrayRef<BindingDecl *> Bindings,
967 ValueDecl *Src, QualType DecompType,
968 const ComplexType *CT) {
969 return checkSimpleDecomposition(
970 S, Bindings, Src, DecompType, llvm::APSInt::get(2),
971 S.Context.getQualifiedType(CT->getElementType(),
972 DecompType.getQualifiers()),
973 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
974 return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
975 });
976 }
977
printTemplateArgs(const PrintingPolicy & PrintingPolicy,TemplateArgumentListInfo & Args,const TemplateParameterList * Params)978 static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
979 TemplateArgumentListInfo &Args,
980 const TemplateParameterList *Params) {
981 SmallString<128> SS;
982 llvm::raw_svector_ostream OS(SS);
983 bool First = true;
984 unsigned I = 0;
985 for (auto &Arg : Args.arguments()) {
986 if (!First)
987 OS << ", ";
988 Arg.getArgument().print(
989 PrintingPolicy, OS,
990 TemplateParameterList::shouldIncludeTypeForArgument(Params, I));
991 First = false;
992 I++;
993 }
994 return std::string(OS.str());
995 }
996
lookupStdTypeTraitMember(Sema & S,LookupResult & TraitMemberLookup,SourceLocation Loc,StringRef Trait,TemplateArgumentListInfo & Args,unsigned DiagID)997 static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
998 SourceLocation Loc, StringRef Trait,
999 TemplateArgumentListInfo &Args,
1000 unsigned DiagID) {
1001 auto DiagnoseMissing = [&] {
1002 if (DiagID)
1003 S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
1004 Args, /*Params*/ nullptr);
1005 return true;
1006 };
1007
1008 // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
1009 NamespaceDecl *Std = S.getStdNamespace();
1010 if (!Std)
1011 return DiagnoseMissing();
1012
1013 // Look up the trait itself, within namespace std. We can diagnose various
1014 // problems with this lookup even if we've been asked to not diagnose a
1015 // missing specialization, because this can only fail if the user has been
1016 // declaring their own names in namespace std or we don't support the
1017 // standard library implementation in use.
1018 LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
1019 Loc, Sema::LookupOrdinaryName);
1020 if (!S.LookupQualifiedName(Result, Std))
1021 return DiagnoseMissing();
1022 if (Result.isAmbiguous())
1023 return true;
1024
1025 ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
1026 if (!TraitTD) {
1027 Result.suppressDiagnostics();
1028 NamedDecl *Found = *Result.begin();
1029 S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
1030 S.Diag(Found->getLocation(), diag::note_declared_at);
1031 return true;
1032 }
1033
1034 // Build the template-id.
1035 QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
1036 if (TraitTy.isNull())
1037 return true;
1038 if (!S.isCompleteType(Loc, TraitTy)) {
1039 if (DiagID)
1040 S.RequireCompleteType(
1041 Loc, TraitTy, DiagID,
1042 printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1043 TraitTD->getTemplateParameters()));
1044 return true;
1045 }
1046
1047 CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
1048 assert(RD && "specialization of class template is not a class?");
1049
1050 // Look up the member of the trait type.
1051 S.LookupQualifiedName(TraitMemberLookup, RD);
1052 return TraitMemberLookup.isAmbiguous();
1053 }
1054
1055 static TemplateArgumentLoc
getTrivialIntegralTemplateArgument(Sema & S,SourceLocation Loc,QualType T,uint64_t I)1056 getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
1057 uint64_t I) {
1058 TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
1059 return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
1060 }
1061
1062 static TemplateArgumentLoc
getTrivialTypeTemplateArgument(Sema & S,SourceLocation Loc,QualType T)1063 getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
1064 return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
1065 }
1066
1067 namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1068
isTupleLike(Sema & S,SourceLocation Loc,QualType T,llvm::APSInt & Size)1069 static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
1070 llvm::APSInt &Size) {
1071 EnterExpressionEvaluationContext ContextRAII(
1072 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1073
1074 DeclarationName Value = S.PP.getIdentifierInfo("value");
1075 LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1076
1077 // Form template argument list for tuple_size<T>.
1078 TemplateArgumentListInfo Args(Loc, Loc);
1079 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1080
1081 // If there's no tuple_size specialization or the lookup of 'value' is empty,
1082 // it's not tuple-like.
1083 if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
1084 R.empty())
1085 return IsTupleLike::NotTupleLike;
1086
1087 // If we get this far, we've committed to the tuple interpretation, but
1088 // we can still fail if there actually isn't a usable ::value.
1089
1090 struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1091 LookupResult &R;
1092 TemplateArgumentListInfo &Args;
1093 ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1094 : R(R), Args(Args) {}
1095 Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
1096 SourceLocation Loc) override {
1097 return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1098 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1099 /*Params*/ nullptr);
1100 }
1101 } Diagnoser(R, Args);
1102
1103 ExprResult E =
1104 S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1105 if (E.isInvalid())
1106 return IsTupleLike::Error;
1107
1108 E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser);
1109 if (E.isInvalid())
1110 return IsTupleLike::Error;
1111
1112 return IsTupleLike::TupleLike;
1113 }
1114
1115 /// \return std::tuple_element<I, T>::type.
getTupleLikeElementType(Sema & S,SourceLocation Loc,unsigned I,QualType T)1116 static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
1117 unsigned I, QualType T) {
1118 // Form template argument list for tuple_element<I, T>.
1119 TemplateArgumentListInfo Args(Loc, Loc);
1120 Args.addArgument(
1121 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1122 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1123
1124 DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1125 LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1126 if (lookupStdTypeTraitMember(
1127 S, R, Loc, "tuple_element", Args,
1128 diag::err_decomp_decl_std_tuple_element_not_specialized))
1129 return QualType();
1130
1131 auto *TD = R.getAsSingle<TypeDecl>();
1132 if (!TD) {
1133 R.suppressDiagnostics();
1134 S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1135 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1136 /*Params*/ nullptr);
1137 if (!R.empty())
1138 S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1139 return QualType();
1140 }
1141
1142 return S.Context.getTypeDeclType(TD);
1143 }
1144
1145 namespace {
1146 struct InitializingBinding {
1147 Sema &S;
InitializingBinding__anonb2a824810811::InitializingBinding1148 InitializingBinding(Sema &S, BindingDecl *BD) : S(S) {
1149 Sema::CodeSynthesisContext Ctx;
1150 Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding;
1151 Ctx.PointOfInstantiation = BD->getLocation();
1152 Ctx.Entity = BD;
1153 S.pushCodeSynthesisContext(Ctx);
1154 }
~InitializingBinding__anonb2a824810811::InitializingBinding1155 ~InitializingBinding() {
1156 S.popCodeSynthesisContext();
1157 }
1158 };
1159 }
1160
checkTupleLikeDecomposition(Sema & S,ArrayRef<BindingDecl * > Bindings,VarDecl * Src,QualType DecompType,const llvm::APSInt & TupleSize)1161 static bool checkTupleLikeDecomposition(Sema &S,
1162 ArrayRef<BindingDecl *> Bindings,
1163 VarDecl *Src, QualType DecompType,
1164 const llvm::APSInt &TupleSize) {
1165 if ((int64_t)Bindings.size() != TupleSize) {
1166 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1167 << DecompType << (unsigned)Bindings.size()
1168 << (unsigned)TupleSize.getLimitedValue(UINT_MAX)
1169 << TupleSize.toString(10) << (TupleSize < Bindings.size());
1170 return true;
1171 }
1172
1173 if (Bindings.empty())
1174 return false;
1175
1176 DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1177
1178 // [dcl.decomp]p3:
1179 // The unqualified-id get is looked up in the scope of E by class member
1180 // access lookup ...
1181 LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1182 bool UseMemberGet = false;
1183 if (S.isCompleteType(Src->getLocation(), DecompType)) {
1184 if (auto *RD = DecompType->getAsCXXRecordDecl())
1185 S.LookupQualifiedName(MemberGet, RD);
1186 if (MemberGet.isAmbiguous())
1187 return true;
1188 // ... and if that finds at least one declaration that is a function
1189 // template whose first template parameter is a non-type parameter ...
1190 for (NamedDecl *D : MemberGet) {
1191 if (FunctionTemplateDecl *FTD =
1192 dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
1193 TemplateParameterList *TPL = FTD->getTemplateParameters();
1194 if (TPL->size() != 0 &&
1195 isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
1196 // ... the initializer is e.get<i>().
1197 UseMemberGet = true;
1198 break;
1199 }
1200 }
1201 }
1202 }
1203
1204 unsigned I = 0;
1205 for (auto *B : Bindings) {
1206 InitializingBinding InitContext(S, B);
1207 SourceLocation Loc = B->getLocation();
1208
1209 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1210 if (E.isInvalid())
1211 return true;
1212
1213 // e is an lvalue if the type of the entity is an lvalue reference and
1214 // an xvalue otherwise
1215 if (!Src->getType()->isLValueReferenceType())
1216 E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1217 E.get(), nullptr, VK_XValue,
1218 FPOptionsOverride());
1219
1220 TemplateArgumentListInfo Args(Loc, Loc);
1221 Args.addArgument(
1222 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1223
1224 if (UseMemberGet) {
1225 // if [lookup of member get] finds at least one declaration, the
1226 // initializer is e.get<i-1>().
1227 E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1228 CXXScopeSpec(), SourceLocation(), nullptr,
1229 MemberGet, &Args, nullptr);
1230 if (E.isInvalid())
1231 return true;
1232
1233 E = S.BuildCallExpr(nullptr, E.get(), Loc, None, Loc);
1234 } else {
1235 // Otherwise, the initializer is get<i-1>(e), where get is looked up
1236 // in the associated namespaces.
1237 Expr *Get = UnresolvedLookupExpr::Create(
1238 S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
1239 DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1240 UnresolvedSetIterator(), UnresolvedSetIterator());
1241
1242 Expr *Arg = E.get();
1243 E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
1244 }
1245 if (E.isInvalid())
1246 return true;
1247 Expr *Init = E.get();
1248
1249 // Given the type T designated by std::tuple_element<i - 1, E>::type,
1250 QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1251 if (T.isNull())
1252 return true;
1253
1254 // each vi is a variable of type "reference to T" initialized with the
1255 // initializer, where the reference is an lvalue reference if the
1256 // initializer is an lvalue and an rvalue reference otherwise
1257 QualType RefType =
1258 S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1259 if (RefType.isNull())
1260 return true;
1261 auto *RefVD = VarDecl::Create(
1262 S.Context, Src->getDeclContext(), Loc, Loc,
1263 B->getDeclName().getAsIdentifierInfo(), RefType,
1264 S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
1265 RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
1266 RefVD->setTSCSpec(Src->getTSCSpec());
1267 RefVD->setImplicit();
1268 if (Src->isInlineSpecified())
1269 RefVD->setInlineSpecified();
1270 RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1271
1272 InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
1273 InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
1274 InitializationSequence Seq(S, Entity, Kind, Init);
1275 E = Seq.Perform(S, Entity, Kind, Init);
1276 if (E.isInvalid())
1277 return true;
1278 E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
1279 if (E.isInvalid())
1280 return true;
1281 RefVD->setInit(E.get());
1282 S.CheckCompleteVariableDeclaration(RefVD);
1283
1284 E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
1285 DeclarationNameInfo(B->getDeclName(), Loc),
1286 RefVD);
1287 if (E.isInvalid())
1288 return true;
1289
1290 B->setBinding(T, E.get());
1291 I++;
1292 }
1293
1294 return false;
1295 }
1296
1297 /// Find the base class to decompose in a built-in decomposition of a class type.
1298 /// This base class search is, unfortunately, not quite like any other that we
1299 /// perform anywhere else in C++.
findDecomposableBaseClass(Sema & S,SourceLocation Loc,const CXXRecordDecl * RD,CXXCastPath & BasePath)1300 static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
1301 const CXXRecordDecl *RD,
1302 CXXCastPath &BasePath) {
1303 auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1304 CXXBasePath &Path) {
1305 return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1306 };
1307
1308 const CXXRecordDecl *ClassWithFields = nullptr;
1309 AccessSpecifier AS = AS_public;
1310 if (RD->hasDirectFields())
1311 // [dcl.decomp]p4:
1312 // Otherwise, all of E's non-static data members shall be public direct
1313 // members of E ...
1314 ClassWithFields = RD;
1315 else {
1316 // ... or of ...
1317 CXXBasePaths Paths;
1318 Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1319 if (!RD->lookupInBases(BaseHasFields, Paths)) {
1320 // If no classes have fields, just decompose RD itself. (This will work
1321 // if and only if zero bindings were provided.)
1322 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
1323 }
1324
1325 CXXBasePath *BestPath = nullptr;
1326 for (auto &P : Paths) {
1327 if (!BestPath)
1328 BestPath = &P;
1329 else if (!S.Context.hasSameType(P.back().Base->getType(),
1330 BestPath->back().Base->getType())) {
1331 // ... the same ...
1332 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1333 << false << RD << BestPath->back().Base->getType()
1334 << P.back().Base->getType();
1335 return DeclAccessPair();
1336 } else if (P.Access < BestPath->Access) {
1337 BestPath = &P;
1338 }
1339 }
1340
1341 // ... unambiguous ...
1342 QualType BaseType = BestPath->back().Base->getType();
1343 if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1344 S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1345 << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1346 return DeclAccessPair();
1347 }
1348
1349 // ... [accessible, implied by other rules] base class of E.
1350 S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
1351 *BestPath, diag::err_decomp_decl_inaccessible_base);
1352 AS = BestPath->Access;
1353
1354 ClassWithFields = BaseType->getAsCXXRecordDecl();
1355 S.BuildBasePathArray(Paths, BasePath);
1356 }
1357
1358 // The above search did not check whether the selected class itself has base
1359 // classes with fields, so check that now.
1360 CXXBasePaths Paths;
1361 if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
1362 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1363 << (ClassWithFields == RD) << RD << ClassWithFields
1364 << Paths.front().back().Base->getType();
1365 return DeclAccessPair();
1366 }
1367
1368 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1369 }
1370
checkMemberDecomposition(Sema & S,ArrayRef<BindingDecl * > Bindings,ValueDecl * Src,QualType DecompType,const CXXRecordDecl * OrigRD)1371 static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
1372 ValueDecl *Src, QualType DecompType,
1373 const CXXRecordDecl *OrigRD) {
1374 if (S.RequireCompleteType(Src->getLocation(), DecompType,
1375 diag::err_incomplete_type))
1376 return true;
1377
1378 CXXCastPath BasePath;
1379 DeclAccessPair BasePair =
1380 findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
1381 const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
1382 if (!RD)
1383 return true;
1384 QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
1385 DecompType.getQualifiers());
1386
1387 auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1388 unsigned NumFields =
1389 std::count_if(RD->field_begin(), RD->field_end(),
1390 [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1391 assert(Bindings.size() != NumFields);
1392 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1393 << DecompType << (unsigned)Bindings.size() << NumFields << NumFields
1394 << (NumFields < Bindings.size());
1395 return true;
1396 };
1397
1398 // all of E's non-static data members shall be [...] well-formed
1399 // when named as e.name in the context of the structured binding,
1400 // E shall not have an anonymous union member, ...
1401 unsigned I = 0;
1402 for (auto *FD : RD->fields()) {
1403 if (FD->isUnnamedBitfield())
1404 continue;
1405
1406 // All the non-static data members are required to be nameable, so they
1407 // must all have names.
1408 if (!FD->getDeclName()) {
1409 if (RD->isLambda()) {
1410 S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda);
1411 S.Diag(RD->getLocation(), diag::note_lambda_decl);
1412 return true;
1413 }
1414
1415 if (FD->isAnonymousStructOrUnion()) {
1416 S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1417 << DecompType << FD->getType()->isUnionType();
1418 S.Diag(FD->getLocation(), diag::note_declared_at);
1419 return true;
1420 }
1421
1422 // FIXME: Are there any other ways we could have an anonymous member?
1423 }
1424
1425 // We have a real field to bind.
1426 if (I >= Bindings.size())
1427 return DiagnoseBadNumberOfBindings();
1428 auto *B = Bindings[I++];
1429 SourceLocation Loc = B->getLocation();
1430
1431 // The field must be accessible in the context of the structured binding.
1432 // We already checked that the base class is accessible.
1433 // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
1434 // const_cast here.
1435 S.CheckStructuredBindingMemberAccess(
1436 Loc, const_cast<CXXRecordDecl *>(OrigRD),
1437 DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
1438 BasePair.getAccess(), FD->getAccess())));
1439
1440 // Initialize the binding to Src.FD.
1441 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1442 if (E.isInvalid())
1443 return true;
1444 E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1445 VK_LValue, &BasePath);
1446 if (E.isInvalid())
1447 return true;
1448 E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1449 CXXScopeSpec(), FD,
1450 DeclAccessPair::make(FD, FD->getAccess()),
1451 DeclarationNameInfo(FD->getDeclName(), Loc));
1452 if (E.isInvalid())
1453 return true;
1454
1455 // If the type of the member is T, the referenced type is cv T, where cv is
1456 // the cv-qualification of the decomposition expression.
1457 //
1458 // FIXME: We resolve a defect here: if the field is mutable, we do not add
1459 // 'const' to the type of the field.
1460 Qualifiers Q = DecompType.getQualifiers();
1461 if (FD->isMutable())
1462 Q.removeConst();
1463 B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1464 }
1465
1466 if (I != Bindings.size())
1467 return DiagnoseBadNumberOfBindings();
1468
1469 return false;
1470 }
1471
CheckCompleteDecompositionDeclaration(DecompositionDecl * DD)1472 void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
1473 QualType DecompType = DD->getType();
1474
1475 // If the type of the decomposition is dependent, then so is the type of
1476 // each binding.
1477 if (DecompType->isDependentType()) {
1478 for (auto *B : DD->bindings())
1479 B->setType(Context.DependentTy);
1480 return;
1481 }
1482
1483 DecompType = DecompType.getNonReferenceType();
1484 ArrayRef<BindingDecl*> Bindings = DD->bindings();
1485
1486 // C++1z [dcl.decomp]/2:
1487 // If E is an array type [...]
1488 // As an extension, we also support decomposition of built-in complex and
1489 // vector types.
1490 if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1491 if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1492 DD->setInvalidDecl();
1493 return;
1494 }
1495 if (auto *VT = DecompType->getAs<VectorType>()) {
1496 if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1497 DD->setInvalidDecl();
1498 return;
1499 }
1500 if (auto *CT = DecompType->getAs<ComplexType>()) {
1501 if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1502 DD->setInvalidDecl();
1503 return;
1504 }
1505
1506 // C++1z [dcl.decomp]/3:
1507 // if the expression std::tuple_size<E>::value is a well-formed integral
1508 // constant expression, [...]
1509 llvm::APSInt TupleSize(32);
1510 switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1511 case IsTupleLike::Error:
1512 DD->setInvalidDecl();
1513 return;
1514
1515 case IsTupleLike::TupleLike:
1516 if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1517 DD->setInvalidDecl();
1518 return;
1519
1520 case IsTupleLike::NotTupleLike:
1521 break;
1522 }
1523
1524 // C++1z [dcl.dcl]/8:
1525 // [E shall be of array or non-union class type]
1526 CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1527 if (!RD || RD->isUnion()) {
1528 Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1529 << DD << !RD << DecompType;
1530 DD->setInvalidDecl();
1531 return;
1532 }
1533
1534 // C++1z [dcl.decomp]/4:
1535 // all of E's non-static data members shall be [...] direct members of
1536 // E or of the same unambiguous public base class of E, ...
1537 if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1538 DD->setInvalidDecl();
1539 }
1540
1541 /// Merge the exception specifications of two variable declarations.
1542 ///
1543 /// This is called when there's a redeclaration of a VarDecl. The function
1544 /// checks if the redeclaration might have an exception specification and
1545 /// validates compatibility and merges the specs if necessary.
MergeVarDeclExceptionSpecs(VarDecl * New,VarDecl * Old)1546 void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
1547 // Shortcut if exceptions are disabled.
1548 if (!getLangOpts().CXXExceptions)
1549 return;
1550
1551 assert(Context.hasSameType(New->getType(), Old->getType()) &&
1552 "Should only be called if types are otherwise the same.");
1553
1554 QualType NewType = New->getType();
1555 QualType OldType = Old->getType();
1556
1557 // We're only interested in pointers and references to functions, as well
1558 // as pointers to member functions.
1559 if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1560 NewType = R->getPointeeType();
1561 OldType = OldType->castAs<ReferenceType>()->getPointeeType();
1562 } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1563 NewType = P->getPointeeType();
1564 OldType = OldType->castAs<PointerType>()->getPointeeType();
1565 } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1566 NewType = M->getPointeeType();
1567 OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
1568 }
1569
1570 if (!NewType->isFunctionProtoType())
1571 return;
1572
1573 // There's lots of special cases for functions. For function pointers, system
1574 // libraries are hopefully not as broken so that we don't need these
1575 // workarounds.
1576 if (CheckEquivalentExceptionSpec(
1577 OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1578 NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1579 New->setInvalidDecl();
1580 }
1581 }
1582
1583 /// CheckCXXDefaultArguments - Verify that the default arguments for a
1584 /// function declaration are well-formed according to C++
1585 /// [dcl.fct.default].
CheckCXXDefaultArguments(FunctionDecl * FD)1586 void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
1587 unsigned NumParams = FD->getNumParams();
1588 unsigned ParamIdx = 0;
1589
1590 // This checking doesn't make sense for explicit specializations; their
1591 // default arguments are determined by the declaration we're specializing,
1592 // not by FD.
1593 if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1594 return;
1595 if (auto *FTD = FD->getDescribedFunctionTemplate())
1596 if (FTD->isMemberSpecialization())
1597 return;
1598
1599 // Find first parameter with a default argument
1600 for (; ParamIdx < NumParams; ++ParamIdx) {
1601 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1602 if (Param->hasDefaultArg())
1603 break;
1604 }
1605
1606 // C++20 [dcl.fct.default]p4:
1607 // In a given function declaration, each parameter subsequent to a parameter
1608 // with a default argument shall have a default argument supplied in this or
1609 // a previous declaration, unless the parameter was expanded from a
1610 // parameter pack, or shall be a function parameter pack.
1611 for (; ParamIdx < NumParams; ++ParamIdx) {
1612 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1613 if (!Param->hasDefaultArg() && !Param->isParameterPack() &&
1614 !(CurrentInstantiationScope &&
1615 CurrentInstantiationScope->isLocalPackExpansion(Param))) {
1616 if (Param->isInvalidDecl())
1617 /* We already complained about this parameter. */;
1618 else if (Param->getIdentifier())
1619 Diag(Param->getLocation(),
1620 diag::err_param_default_argument_missing_name)
1621 << Param->getIdentifier();
1622 else
1623 Diag(Param->getLocation(),
1624 diag::err_param_default_argument_missing);
1625 }
1626 }
1627 }
1628
1629 /// Check that the given type is a literal type. Issue a diagnostic if not,
1630 /// if Kind is Diagnose.
1631 /// \return \c true if a problem has been found (and optionally diagnosed).
1632 template <typename... Ts>
CheckLiteralType(Sema & SemaRef,Sema::CheckConstexprKind Kind,SourceLocation Loc,QualType T,unsigned DiagID,Ts &&...DiagArgs)1633 static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
1634 SourceLocation Loc, QualType T, unsigned DiagID,
1635 Ts &&...DiagArgs) {
1636 if (T->isDependentType())
1637 return false;
1638
1639 switch (Kind) {
1640 case Sema::CheckConstexprKind::Diagnose:
1641 return SemaRef.RequireLiteralType(Loc, T, DiagID,
1642 std::forward<Ts>(DiagArgs)...);
1643
1644 case Sema::CheckConstexprKind::CheckValid:
1645 return !T->isLiteralType(SemaRef.Context);
1646 }
1647
1648 llvm_unreachable("unknown CheckConstexprKind");
1649 }
1650
1651 /// Determine whether a destructor cannot be constexpr due to
CheckConstexprDestructorSubobjects(Sema & SemaRef,const CXXDestructorDecl * DD,Sema::CheckConstexprKind Kind)1652 static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
1653 const CXXDestructorDecl *DD,
1654 Sema::CheckConstexprKind Kind) {
1655 auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
1656 const CXXRecordDecl *RD =
1657 T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
1658 if (!RD || RD->hasConstexprDestructor())
1659 return true;
1660
1661 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1662 SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
1663 << static_cast<int>(DD->getConstexprKind()) << !FD
1664 << (FD ? FD->getDeclName() : DeclarationName()) << T;
1665 SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
1666 << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
1667 }
1668 return false;
1669 };
1670
1671 const CXXRecordDecl *RD = DD->getParent();
1672 for (const CXXBaseSpecifier &B : RD->bases())
1673 if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
1674 return false;
1675 for (const FieldDecl *FD : RD->fields())
1676 if (!Check(FD->getLocation(), FD->getType(), FD))
1677 return false;
1678 return true;
1679 }
1680
1681 /// Check whether a function's parameter types are all literal types. If so,
1682 /// return true. If not, produce a suitable diagnostic and return false.
CheckConstexprParameterTypes(Sema & SemaRef,const FunctionDecl * FD,Sema::CheckConstexprKind Kind)1683 static bool CheckConstexprParameterTypes(Sema &SemaRef,
1684 const FunctionDecl *FD,
1685 Sema::CheckConstexprKind Kind) {
1686 unsigned ArgIndex = 0;
1687 const auto *FT = FD->getType()->castAs<FunctionProtoType>();
1688 for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
1689 e = FT->param_type_end();
1690 i != e; ++i, ++ArgIndex) {
1691 const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1692 SourceLocation ParamLoc = PD->getLocation();
1693 if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
1694 diag::err_constexpr_non_literal_param, ArgIndex + 1,
1695 PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
1696 FD->isConsteval()))
1697 return false;
1698 }
1699 return true;
1700 }
1701
1702 /// Check whether a function's return type is a literal type. If so, return
1703 /// true. If not, produce a suitable diagnostic and return false.
CheckConstexprReturnType(Sema & SemaRef,const FunctionDecl * FD,Sema::CheckConstexprKind Kind)1704 static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
1705 Sema::CheckConstexprKind Kind) {
1706 if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
1707 diag::err_constexpr_non_literal_return,
1708 FD->isConsteval()))
1709 return false;
1710 return true;
1711 }
1712
1713 /// Get diagnostic %select index for tag kind for
1714 /// record diagnostic message.
1715 /// WARNING: Indexes apply to particular diagnostics only!
1716 ///
1717 /// \returns diagnostic %select index.
getRecordDiagFromTagKind(TagTypeKind Tag)1718 static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
1719 switch (Tag) {
1720 case TTK_Struct: return 0;
1721 case TTK_Interface: return 1;
1722 case TTK_Class: return 2;
1723 default: llvm_unreachable("Invalid tag kind for record diagnostic!");
1724 }
1725 }
1726
1727 static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
1728 Stmt *Body,
1729 Sema::CheckConstexprKind Kind);
1730
1731 // Check whether a function declaration satisfies the requirements of a
1732 // constexpr function definition or a constexpr constructor definition. If so,
1733 // return true. If not, produce appropriate diagnostics (unless asked not to by
1734 // Kind) and return false.
1735 //
1736 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
CheckConstexprFunctionDefinition(const FunctionDecl * NewFD,CheckConstexprKind Kind)1737 bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
1738 CheckConstexprKind Kind) {
1739 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1740 if (MD && MD->isInstance()) {
1741 // C++11 [dcl.constexpr]p4:
1742 // The definition of a constexpr constructor shall satisfy the following
1743 // constraints:
1744 // - the class shall not have any virtual base classes;
1745 //
1746 // FIXME: This only applies to constructors and destructors, not arbitrary
1747 // member functions.
1748 const CXXRecordDecl *RD = MD->getParent();
1749 if (RD->getNumVBases()) {
1750 if (Kind == CheckConstexprKind::CheckValid)
1751 return false;
1752
1753 Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1754 << isa<CXXConstructorDecl>(NewFD)
1755 << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
1756 for (const auto &I : RD->vbases())
1757 Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1758 << I.getSourceRange();
1759 return false;
1760 }
1761 }
1762
1763 if (!isa<CXXConstructorDecl>(NewFD)) {
1764 // C++11 [dcl.constexpr]p3:
1765 // The definition of a constexpr function shall satisfy the following
1766 // constraints:
1767 // - it shall not be virtual; (removed in C++20)
1768 const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1769 if (Method && Method->isVirtual()) {
1770 if (getLangOpts().CPlusPlus20) {
1771 if (Kind == CheckConstexprKind::Diagnose)
1772 Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
1773 } else {
1774 if (Kind == CheckConstexprKind::CheckValid)
1775 return false;
1776
1777 Method = Method->getCanonicalDecl();
1778 Diag(Method->getLocation(), diag::err_constexpr_virtual);
1779
1780 // If it's not obvious why this function is virtual, find an overridden
1781 // function which uses the 'virtual' keyword.
1782 const CXXMethodDecl *WrittenVirtual = Method;
1783 while (!WrittenVirtual->isVirtualAsWritten())
1784 WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1785 if (WrittenVirtual != Method)
1786 Diag(WrittenVirtual->getLocation(),
1787 diag::note_overridden_virtual_function);
1788 return false;
1789 }
1790 }
1791
1792 // - its return type shall be a literal type;
1793 if (!CheckConstexprReturnType(*this, NewFD, Kind))
1794 return false;
1795 }
1796
1797 if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
1798 // A destructor can be constexpr only if the defaulted destructor could be;
1799 // we don't need to check the members and bases if we already know they all
1800 // have constexpr destructors.
1801 if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
1802 if (Kind == CheckConstexprKind::CheckValid)
1803 return false;
1804 if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
1805 return false;
1806 }
1807 }
1808
1809 // - each of its parameter types shall be a literal type;
1810 if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
1811 return false;
1812
1813 Stmt *Body = NewFD->getBody();
1814 assert(Body &&
1815 "CheckConstexprFunctionDefinition called on function with no body");
1816 return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1817 }
1818
1819 /// Check the given declaration statement is legal within a constexpr function
1820 /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1821 ///
1822 /// \return true if the body is OK (maybe only as an extension), false if we
1823 /// have diagnosed a problem.
CheckConstexprDeclStmt(Sema & SemaRef,const FunctionDecl * Dcl,DeclStmt * DS,SourceLocation & Cxx1yLoc,Sema::CheckConstexprKind Kind)1824 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1825 DeclStmt *DS, SourceLocation &Cxx1yLoc,
1826 Sema::CheckConstexprKind Kind) {
1827 // C++11 [dcl.constexpr]p3 and p4:
1828 // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1829 // contain only
1830 for (const auto *DclIt : DS->decls()) {
1831 switch (DclIt->getKind()) {
1832 case Decl::StaticAssert:
1833 case Decl::Using:
1834 case Decl::UsingShadow:
1835 case Decl::UsingDirective:
1836 case Decl::UnresolvedUsingTypename:
1837 case Decl::UnresolvedUsingValue:
1838 // - static_assert-declarations
1839 // - using-declarations,
1840 // - using-directives,
1841 continue;
1842
1843 case Decl::Typedef:
1844 case Decl::TypeAlias: {
1845 // - typedef declarations and alias-declarations that do not define
1846 // classes or enumerations,
1847 const auto *TN = cast<TypedefNameDecl>(DclIt);
1848 if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1849 // Don't allow variably-modified types in constexpr functions.
1850 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1851 TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1852 SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1853 << TL.getSourceRange() << TL.getType()
1854 << isa<CXXConstructorDecl>(Dcl);
1855 }
1856 return false;
1857 }
1858 continue;
1859 }
1860
1861 case Decl::Enum:
1862 case Decl::CXXRecord:
1863 // C++1y allows types to be defined, not just declared.
1864 if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
1865 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1866 SemaRef.Diag(DS->getBeginLoc(),
1867 SemaRef.getLangOpts().CPlusPlus14
1868 ? diag::warn_cxx11_compat_constexpr_type_definition
1869 : diag::ext_constexpr_type_definition)
1870 << isa<CXXConstructorDecl>(Dcl);
1871 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1872 return false;
1873 }
1874 }
1875 continue;
1876
1877 case Decl::EnumConstant:
1878 case Decl::IndirectField:
1879 case Decl::ParmVar:
1880 // These can only appear with other declarations which are banned in
1881 // C++11 and permitted in C++1y, so ignore them.
1882 continue;
1883
1884 case Decl::Var:
1885 case Decl::Decomposition: {
1886 // C++1y [dcl.constexpr]p3 allows anything except:
1887 // a definition of a variable of non-literal type or of static or
1888 // thread storage duration or [before C++2a] for which no
1889 // initialization is performed.
1890 const auto *VD = cast<VarDecl>(DclIt);
1891 if (VD->isThisDeclarationADefinition()) {
1892 if (VD->isStaticLocal()) {
1893 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1894 SemaRef.Diag(VD->getLocation(),
1895 diag::err_constexpr_local_var_static)
1896 << isa<CXXConstructorDecl>(Dcl)
1897 << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1898 }
1899 return false;
1900 }
1901 if (CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
1902 diag::err_constexpr_local_var_non_literal_type,
1903 isa<CXXConstructorDecl>(Dcl)))
1904 return false;
1905 if (!VD->getType()->isDependentType() &&
1906 !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1907 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1908 SemaRef.Diag(
1909 VD->getLocation(),
1910 SemaRef.getLangOpts().CPlusPlus20
1911 ? diag::warn_cxx17_compat_constexpr_local_var_no_init
1912 : diag::ext_constexpr_local_var_no_init)
1913 << isa<CXXConstructorDecl>(Dcl);
1914 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
1915 return false;
1916 }
1917 continue;
1918 }
1919 }
1920 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1921 SemaRef.Diag(VD->getLocation(),
1922 SemaRef.getLangOpts().CPlusPlus14
1923 ? diag::warn_cxx11_compat_constexpr_local_var
1924 : diag::ext_constexpr_local_var)
1925 << isa<CXXConstructorDecl>(Dcl);
1926 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1927 return false;
1928 }
1929 continue;
1930 }
1931
1932 case Decl::NamespaceAlias:
1933 case Decl::Function:
1934 // These are disallowed in C++11 and permitted in C++1y. Allow them
1935 // everywhere as an extension.
1936 if (!Cxx1yLoc.isValid())
1937 Cxx1yLoc = DS->getBeginLoc();
1938 continue;
1939
1940 default:
1941 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1942 SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1943 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
1944 }
1945 return false;
1946 }
1947 }
1948
1949 return true;
1950 }
1951
1952 /// Check that the given field is initialized within a constexpr constructor.
1953 ///
1954 /// \param Dcl The constexpr constructor being checked.
1955 /// \param Field The field being checked. This may be a member of an anonymous
1956 /// struct or union nested within the class being checked.
1957 /// \param Inits All declarations, including anonymous struct/union members and
1958 /// indirect members, for which any initialization was provided.
1959 /// \param Diagnosed Whether we've emitted the error message yet. Used to attach
1960 /// multiple notes for different members to the same error.
1961 /// \param Kind Whether we're diagnosing a constructor as written or determining
1962 /// whether the formal requirements are satisfied.
1963 /// \return \c false if we're checking for validity and the constructor does
1964 /// not satisfy the requirements on a constexpr constructor.
CheckConstexprCtorInitializer(Sema & SemaRef,const FunctionDecl * Dcl,FieldDecl * Field,llvm::SmallSet<Decl *,16> & Inits,bool & Diagnosed,Sema::CheckConstexprKind Kind)1965 static bool CheckConstexprCtorInitializer(Sema &SemaRef,
1966 const FunctionDecl *Dcl,
1967 FieldDecl *Field,
1968 llvm::SmallSet<Decl*, 16> &Inits,
1969 bool &Diagnosed,
1970 Sema::CheckConstexprKind Kind) {
1971 // In C++20 onwards, there's nothing to check for validity.
1972 if (Kind == Sema::CheckConstexprKind::CheckValid &&
1973 SemaRef.getLangOpts().CPlusPlus20)
1974 return true;
1975
1976 if (Field->isInvalidDecl())
1977 return true;
1978
1979 if (Field->isUnnamedBitfield())
1980 return true;
1981
1982 // Anonymous unions with no variant members and empty anonymous structs do not
1983 // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1984 // indirect fields don't need initializing.
1985 if (Field->isAnonymousStructOrUnion() &&
1986 (Field->getType()->isUnionType()
1987 ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1988 : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1989 return true;
1990
1991 if (!Inits.count(Field)) {
1992 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1993 if (!Diagnosed) {
1994 SemaRef.Diag(Dcl->getLocation(),
1995 SemaRef.getLangOpts().CPlusPlus20
1996 ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
1997 : diag::ext_constexpr_ctor_missing_init);
1998 Diagnosed = true;
1999 }
2000 SemaRef.Diag(Field->getLocation(),
2001 diag::note_constexpr_ctor_missing_init);
2002 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2003 return false;
2004 }
2005 } else if (Field->isAnonymousStructOrUnion()) {
2006 const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
2007 for (auto *I : RD->fields())
2008 // If an anonymous union contains an anonymous struct of which any member
2009 // is initialized, all members must be initialized.
2010 if (!RD->isUnion() || Inits.count(I))
2011 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2012 Kind))
2013 return false;
2014 }
2015 return true;
2016 }
2017
2018 /// Check the provided statement is allowed in a constexpr function
2019 /// definition.
2020 static bool
CheckConstexprFunctionStmt(Sema & SemaRef,const FunctionDecl * Dcl,Stmt * S,SmallVectorImpl<SourceLocation> & ReturnStmts,SourceLocation & Cxx1yLoc,SourceLocation & Cxx2aLoc,Sema::CheckConstexprKind Kind)2021 CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
2022 SmallVectorImpl<SourceLocation> &ReturnStmts,
2023 SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
2024 Sema::CheckConstexprKind Kind) {
2025 // - its function-body shall be [...] a compound-statement that contains only
2026 switch (S->getStmtClass()) {
2027 case Stmt::NullStmtClass:
2028 // - null statements,
2029 return true;
2030
2031 case Stmt::DeclStmtClass:
2032 // - static_assert-declarations
2033 // - using-declarations,
2034 // - using-directives,
2035 // - typedef declarations and alias-declarations that do not define
2036 // classes or enumerations,
2037 if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
2038 return false;
2039 return true;
2040
2041 case Stmt::ReturnStmtClass:
2042 // - and exactly one return statement;
2043 if (isa<CXXConstructorDecl>(Dcl)) {
2044 // C++1y allows return statements in constexpr constructors.
2045 if (!Cxx1yLoc.isValid())
2046 Cxx1yLoc = S->getBeginLoc();
2047 return true;
2048 }
2049
2050 ReturnStmts.push_back(S->getBeginLoc());
2051 return true;
2052
2053 case Stmt::CompoundStmtClass: {
2054 // C++1y allows compound-statements.
2055 if (!Cxx1yLoc.isValid())
2056 Cxx1yLoc = S->getBeginLoc();
2057
2058 CompoundStmt *CompStmt = cast<CompoundStmt>(S);
2059 for (auto *BodyIt : CompStmt->body()) {
2060 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
2061 Cxx1yLoc, Cxx2aLoc, Kind))
2062 return false;
2063 }
2064 return true;
2065 }
2066
2067 case Stmt::AttributedStmtClass:
2068 if (!Cxx1yLoc.isValid())
2069 Cxx1yLoc = S->getBeginLoc();
2070 return true;
2071
2072 case Stmt::IfStmtClass: {
2073 // C++1y allows if-statements.
2074 if (!Cxx1yLoc.isValid())
2075 Cxx1yLoc = S->getBeginLoc();
2076
2077 IfStmt *If = cast<IfStmt>(S);
2078 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
2079 Cxx1yLoc, Cxx2aLoc, Kind))
2080 return false;
2081 if (If->getElse() &&
2082 !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
2083 Cxx1yLoc, Cxx2aLoc, Kind))
2084 return false;
2085 return true;
2086 }
2087
2088 case Stmt::WhileStmtClass:
2089 case Stmt::DoStmtClass:
2090 case Stmt::ForStmtClass:
2091 case Stmt::CXXForRangeStmtClass:
2092 case Stmt::ContinueStmtClass:
2093 // C++1y allows all of these. We don't allow them as extensions in C++11,
2094 // because they don't make sense without variable mutation.
2095 if (!SemaRef.getLangOpts().CPlusPlus14)
2096 break;
2097 if (!Cxx1yLoc.isValid())
2098 Cxx1yLoc = S->getBeginLoc();
2099 for (Stmt *SubStmt : S->children())
2100 if (SubStmt &&
2101 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2102 Cxx1yLoc, Cxx2aLoc, Kind))
2103 return false;
2104 return true;
2105
2106 case Stmt::SwitchStmtClass:
2107 case Stmt::CaseStmtClass:
2108 case Stmt::DefaultStmtClass:
2109 case Stmt::BreakStmtClass:
2110 // C++1y allows switch-statements, and since they don't need variable
2111 // mutation, we can reasonably allow them in C++11 as an extension.
2112 if (!Cxx1yLoc.isValid())
2113 Cxx1yLoc = S->getBeginLoc();
2114 for (Stmt *SubStmt : S->children())
2115 if (SubStmt &&
2116 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2117 Cxx1yLoc, Cxx2aLoc, Kind))
2118 return false;
2119 return true;
2120
2121 case Stmt::GCCAsmStmtClass:
2122 case Stmt::MSAsmStmtClass:
2123 // C++2a allows inline assembly statements.
2124 case Stmt::CXXTryStmtClass:
2125 if (Cxx2aLoc.isInvalid())
2126 Cxx2aLoc = S->getBeginLoc();
2127 for (Stmt *SubStmt : S->children()) {
2128 if (SubStmt &&
2129 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2130 Cxx1yLoc, Cxx2aLoc, Kind))
2131 return false;
2132 }
2133 return true;
2134
2135 case Stmt::CXXCatchStmtClass:
2136 // Do not bother checking the language mode (already covered by the
2137 // try block check).
2138 if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
2139 cast<CXXCatchStmt>(S)->getHandlerBlock(),
2140 ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind))
2141 return false;
2142 return true;
2143
2144 default:
2145 if (!isa<Expr>(S))
2146 break;
2147
2148 // C++1y allows expression-statements.
2149 if (!Cxx1yLoc.isValid())
2150 Cxx1yLoc = S->getBeginLoc();
2151 return true;
2152 }
2153
2154 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2155 SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
2156 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2157 }
2158 return false;
2159 }
2160
2161 /// Check the body for the given constexpr function declaration only contains
2162 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2163 ///
2164 /// \return true if the body is OK, false if we have found or diagnosed a
2165 /// problem.
CheckConstexprFunctionBody(Sema & SemaRef,const FunctionDecl * Dcl,Stmt * Body,Sema::CheckConstexprKind Kind)2166 static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
2167 Stmt *Body,
2168 Sema::CheckConstexprKind Kind) {
2169 SmallVector<SourceLocation, 4> ReturnStmts;
2170
2171 if (isa<CXXTryStmt>(Body)) {
2172 // C++11 [dcl.constexpr]p3:
2173 // The definition of a constexpr function shall satisfy the following
2174 // constraints: [...]
2175 // - its function-body shall be = delete, = default, or a
2176 // compound-statement
2177 //
2178 // C++11 [dcl.constexpr]p4:
2179 // In the definition of a constexpr constructor, [...]
2180 // - its function-body shall not be a function-try-block;
2181 //
2182 // This restriction is lifted in C++2a, as long as inner statements also
2183 // apply the general constexpr rules.
2184 switch (Kind) {
2185 case Sema::CheckConstexprKind::CheckValid:
2186 if (!SemaRef.getLangOpts().CPlusPlus20)
2187 return false;
2188 break;
2189
2190 case Sema::CheckConstexprKind::Diagnose:
2191 SemaRef.Diag(Body->getBeginLoc(),
2192 !SemaRef.getLangOpts().CPlusPlus20
2193 ? diag::ext_constexpr_function_try_block_cxx20
2194 : diag::warn_cxx17_compat_constexpr_function_try_block)
2195 << isa<CXXConstructorDecl>(Dcl);
2196 break;
2197 }
2198 }
2199
2200 // - its function-body shall be [...] a compound-statement that contains only
2201 // [... list of cases ...]
2202 //
2203 // Note that walking the children here is enough to properly check for
2204 // CompoundStmt and CXXTryStmt body.
2205 SourceLocation Cxx1yLoc, Cxx2aLoc;
2206 for (Stmt *SubStmt : Body->children()) {
2207 if (SubStmt &&
2208 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2209 Cxx1yLoc, Cxx2aLoc, Kind))
2210 return false;
2211 }
2212
2213 if (Kind == Sema::CheckConstexprKind::CheckValid) {
2214 // If this is only valid as an extension, report that we don't satisfy the
2215 // constraints of the current language.
2216 if ((Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) ||
2217 (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
2218 return false;
2219 } else if (Cxx2aLoc.isValid()) {
2220 SemaRef.Diag(Cxx2aLoc,
2221 SemaRef.getLangOpts().CPlusPlus20
2222 ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
2223 : diag::ext_constexpr_body_invalid_stmt_cxx20)
2224 << isa<CXXConstructorDecl>(Dcl);
2225 } else if (Cxx1yLoc.isValid()) {
2226 SemaRef.Diag(Cxx1yLoc,
2227 SemaRef.getLangOpts().CPlusPlus14
2228 ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
2229 : diag::ext_constexpr_body_invalid_stmt)
2230 << isa<CXXConstructorDecl>(Dcl);
2231 }
2232
2233 if (const CXXConstructorDecl *Constructor
2234 = dyn_cast<CXXConstructorDecl>(Dcl)) {
2235 const CXXRecordDecl *RD = Constructor->getParent();
2236 // DR1359:
2237 // - every non-variant non-static data member and base class sub-object
2238 // shall be initialized;
2239 // DR1460:
2240 // - if the class is a union having variant members, exactly one of them
2241 // shall be initialized;
2242 if (RD->isUnion()) {
2243 if (Constructor->getNumCtorInitializers() == 0 &&
2244 RD->hasVariantMembers()) {
2245 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2246 SemaRef.Diag(
2247 Dcl->getLocation(),
2248 SemaRef.getLangOpts().CPlusPlus20
2249 ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
2250 : diag::ext_constexpr_union_ctor_no_init);
2251 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2252 return false;
2253 }
2254 }
2255 } else if (!Constructor->isDependentContext() &&
2256 !Constructor->isDelegatingConstructor()) {
2257 assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
2258
2259 // Skip detailed checking if we have enough initializers, and we would
2260 // allow at most one initializer per member.
2261 bool AnyAnonStructUnionMembers = false;
2262 unsigned Fields = 0;
2263 for (CXXRecordDecl::field_iterator I = RD->field_begin(),
2264 E = RD->field_end(); I != E; ++I, ++Fields) {
2265 if (I->isAnonymousStructOrUnion()) {
2266 AnyAnonStructUnionMembers = true;
2267 break;
2268 }
2269 }
2270 // DR1460:
2271 // - if the class is a union-like class, but is not a union, for each of
2272 // its anonymous union members having variant members, exactly one of
2273 // them shall be initialized;
2274 if (AnyAnonStructUnionMembers ||
2275 Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
2276 // Check initialization of non-static data members. Base classes are
2277 // always initialized so do not need to be checked. Dependent bases
2278 // might not have initializers in the member initializer list.
2279 llvm::SmallSet<Decl*, 16> Inits;
2280 for (const auto *I: Constructor->inits()) {
2281 if (FieldDecl *FD = I->getMember())
2282 Inits.insert(FD);
2283 else if (IndirectFieldDecl *ID = I->getIndirectMember())
2284 Inits.insert(ID->chain_begin(), ID->chain_end());
2285 }
2286
2287 bool Diagnosed = false;
2288 for (auto *I : RD->fields())
2289 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2290 Kind))
2291 return false;
2292 }
2293 }
2294 } else {
2295 if (ReturnStmts.empty()) {
2296 // C++1y doesn't require constexpr functions to contain a 'return'
2297 // statement. We still do, unless the return type might be void, because
2298 // otherwise if there's no return statement, the function cannot
2299 // be used in a core constant expression.
2300 bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
2301 (Dcl->getReturnType()->isVoidType() ||
2302 Dcl->getReturnType()->isDependentType());
2303 switch (Kind) {
2304 case Sema::CheckConstexprKind::Diagnose:
2305 SemaRef.Diag(Dcl->getLocation(),
2306 OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2307 : diag::err_constexpr_body_no_return)
2308 << Dcl->isConsteval();
2309 if (!OK)
2310 return false;
2311 break;
2312
2313 case Sema::CheckConstexprKind::CheckValid:
2314 // The formal requirements don't include this rule in C++14, even
2315 // though the "must be able to produce a constant expression" rules
2316 // still imply it in some cases.
2317 if (!SemaRef.getLangOpts().CPlusPlus14)
2318 return false;
2319 break;
2320 }
2321 } else if (ReturnStmts.size() > 1) {
2322 switch (Kind) {
2323 case Sema::CheckConstexprKind::Diagnose:
2324 SemaRef.Diag(
2325 ReturnStmts.back(),
2326 SemaRef.getLangOpts().CPlusPlus14
2327 ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2328 : diag::ext_constexpr_body_multiple_return);
2329 for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2330 SemaRef.Diag(ReturnStmts[I],
2331 diag::note_constexpr_body_previous_return);
2332 break;
2333
2334 case Sema::CheckConstexprKind::CheckValid:
2335 if (!SemaRef.getLangOpts().CPlusPlus14)
2336 return false;
2337 break;
2338 }
2339 }
2340 }
2341
2342 // C++11 [dcl.constexpr]p5:
2343 // if no function argument values exist such that the function invocation
2344 // substitution would produce a constant expression, the program is
2345 // ill-formed; no diagnostic required.
2346 // C++11 [dcl.constexpr]p3:
2347 // - every constructor call and implicit conversion used in initializing the
2348 // return value shall be one of those allowed in a constant expression.
2349 // C++11 [dcl.constexpr]p4:
2350 // - every constructor involved in initializing non-static data members and
2351 // base class sub-objects shall be a constexpr constructor.
2352 //
2353 // Note that this rule is distinct from the "requirements for a constexpr
2354 // function", so is not checked in CheckValid mode.
2355 SmallVector<PartialDiagnosticAt, 8> Diags;
2356 if (Kind == Sema::CheckConstexprKind::Diagnose &&
2357 !Expr::isPotentialConstantExpr(Dcl, Diags)) {
2358 SemaRef.Diag(Dcl->getLocation(),
2359 diag::ext_constexpr_function_never_constant_expr)
2360 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2361 for (size_t I = 0, N = Diags.size(); I != N; ++I)
2362 SemaRef.Diag(Diags[I].first, Diags[I].second);
2363 // Don't return false here: we allow this for compatibility in
2364 // system headers.
2365 }
2366
2367 return true;
2368 }
2369
2370 /// Get the class that is directly named by the current context. This is the
2371 /// class for which an unqualified-id in this scope could name a constructor
2372 /// or destructor.
2373 ///
2374 /// If the scope specifier denotes a class, this will be that class.
2375 /// If the scope specifier is empty, this will be the class whose
2376 /// member-specification we are currently within. Otherwise, there
2377 /// is no such class.
getCurrentClass(Scope *,const CXXScopeSpec * SS)2378 CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
2379 assert(getLangOpts().CPlusPlus && "No class names in C!");
2380
2381 if (SS && SS->isInvalid())
2382 return nullptr;
2383
2384 if (SS && SS->isNotEmpty()) {
2385 DeclContext *DC = computeDeclContext(*SS, true);
2386 return dyn_cast_or_null<CXXRecordDecl>(DC);
2387 }
2388
2389 return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2390 }
2391
2392 /// isCurrentClassName - Determine whether the identifier II is the
2393 /// name of the class type currently being defined. In the case of
2394 /// nested classes, this will only return true if II is the name of
2395 /// the innermost class.
isCurrentClassName(const IdentifierInfo & II,Scope * S,const CXXScopeSpec * SS)2396 bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
2397 const CXXScopeSpec *SS) {
2398 CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2399 return CurDecl && &II == CurDecl->getIdentifier();
2400 }
2401
2402 /// Determine whether the identifier II is a typo for the name of
2403 /// the class type currently being defined. If so, update it to the identifier
2404 /// that should have been used.
isCurrentClassNameTypo(IdentifierInfo * & II,const CXXScopeSpec * SS)2405 bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
2406 assert(getLangOpts().CPlusPlus && "No class names in C!");
2407
2408 if (!getLangOpts().SpellChecking)
2409 return false;
2410
2411 CXXRecordDecl *CurDecl;
2412 if (SS && SS->isSet() && !SS->isInvalid()) {
2413 DeclContext *DC = computeDeclContext(*SS, true);
2414 CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2415 } else
2416 CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2417
2418 if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2419 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2420 < II->getLength()) {
2421 II = CurDecl->getIdentifier();
2422 return true;
2423 }
2424
2425 return false;
2426 }
2427
2428 /// Determine whether the given class is a base class of the given
2429 /// class, including looking at dependent bases.
findCircularInheritance(const CXXRecordDecl * Class,const CXXRecordDecl * Current)2430 static bool findCircularInheritance(const CXXRecordDecl *Class,
2431 const CXXRecordDecl *Current) {
2432 SmallVector<const CXXRecordDecl*, 8> Queue;
2433
2434 Class = Class->getCanonicalDecl();
2435 while (true) {
2436 for (const auto &I : Current->bases()) {
2437 CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2438 if (!Base)
2439 continue;
2440
2441 Base = Base->getDefinition();
2442 if (!Base)
2443 continue;
2444
2445 if (Base->getCanonicalDecl() == Class)
2446 return true;
2447
2448 Queue.push_back(Base);
2449 }
2450
2451 if (Queue.empty())
2452 return false;
2453
2454 Current = Queue.pop_back_val();
2455 }
2456
2457 return false;
2458 }
2459
2460 /// Check the validity of a C++ base class specifier.
2461 ///
2462 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2463 /// and returns NULL otherwise.
2464 CXXBaseSpecifier *
CheckBaseSpecifier(CXXRecordDecl * Class,SourceRange SpecifierRange,bool Virtual,AccessSpecifier Access,TypeSourceInfo * TInfo,SourceLocation EllipsisLoc)2465 Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
2466 SourceRange SpecifierRange,
2467 bool Virtual, AccessSpecifier Access,
2468 TypeSourceInfo *TInfo,
2469 SourceLocation EllipsisLoc) {
2470 QualType BaseType = TInfo->getType();
2471 if (BaseType->containsErrors()) {
2472 // Already emitted a diagnostic when parsing the error type.
2473 return nullptr;
2474 }
2475 // C++ [class.union]p1:
2476 // A union shall not have base classes.
2477 if (Class->isUnion()) {
2478 Diag(Class->getLocation(), diag::err_base_clause_on_union)
2479 << SpecifierRange;
2480 return nullptr;
2481 }
2482
2483 if (EllipsisLoc.isValid() &&
2484 !TInfo->getType()->containsUnexpandedParameterPack()) {
2485 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2486 << TInfo->getTypeLoc().getSourceRange();
2487 EllipsisLoc = SourceLocation();
2488 }
2489
2490 SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2491
2492 if (BaseType->isDependentType()) {
2493 // Make sure that we don't have circular inheritance among our dependent
2494 // bases. For non-dependent bases, the check for completeness below handles
2495 // this.
2496 if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2497 if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2498 ((BaseDecl = BaseDecl->getDefinition()) &&
2499 findCircularInheritance(Class, BaseDecl))) {
2500 Diag(BaseLoc, diag::err_circular_inheritance)
2501 << BaseType << Context.getTypeDeclType(Class);
2502
2503 if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2504 Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2505 << BaseType;
2506
2507 return nullptr;
2508 }
2509 }
2510
2511 // Make sure that we don't make an ill-formed AST where the type of the
2512 // Class is non-dependent and its attached base class specifier is an
2513 // dependent type, which violates invariants in many clang code paths (e.g.
2514 // constexpr evaluator). If this case happens (in errory-recovery mode), we
2515 // explicitly mark the Class decl invalid. The diagnostic was already
2516 // emitted.
2517 if (!Class->getTypeForDecl()->isDependentType())
2518 Class->setInvalidDecl();
2519 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2520 Class->getTagKind() == TTK_Class,
2521 Access, TInfo, EllipsisLoc);
2522 }
2523
2524 // Base specifiers must be record types.
2525 if (!BaseType->isRecordType()) {
2526 Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2527 return nullptr;
2528 }
2529
2530 // C++ [class.union]p1:
2531 // A union shall not be used as a base class.
2532 if (BaseType->isUnionType()) {
2533 Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2534 return nullptr;
2535 }
2536
2537 // For the MS ABI, propagate DLL attributes to base class templates.
2538 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2539 if (Attr *ClassAttr = getDLLAttr(Class)) {
2540 if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2541 BaseType->getAsCXXRecordDecl())) {
2542 propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2543 BaseLoc);
2544 }
2545 }
2546 }
2547
2548 // C++ [class.derived]p2:
2549 // The class-name in a base-specifier shall not be an incompletely
2550 // defined class.
2551 if (RequireCompleteType(BaseLoc, BaseType,
2552 diag::err_incomplete_base_class, SpecifierRange)) {
2553 Class->setInvalidDecl();
2554 return nullptr;
2555 }
2556
2557 // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2558 RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
2559 assert(BaseDecl && "Record type has no declaration");
2560 BaseDecl = BaseDecl->getDefinition();
2561 assert(BaseDecl && "Base type is not incomplete, but has no definition");
2562 CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2563 assert(CXXBaseDecl && "Base type is not a C++ type");
2564
2565 // Microsoft docs say:
2566 // "If a base-class has a code_seg attribute, derived classes must have the
2567 // same attribute."
2568 const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2569 const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2570 if ((DerivedCSA || BaseCSA) &&
2571 (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2572 Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2573 Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2574 << CXXBaseDecl;
2575 return nullptr;
2576 }
2577
2578 // A class which contains a flexible array member is not suitable for use as a
2579 // base class:
2580 // - If the layout determines that a base comes before another base,
2581 // the flexible array member would index into the subsequent base.
2582 // - If the layout determines that base comes before the derived class,
2583 // the flexible array member would index into the derived class.
2584 if (CXXBaseDecl->hasFlexibleArrayMember()) {
2585 Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2586 << CXXBaseDecl->getDeclName();
2587 return nullptr;
2588 }
2589
2590 // C++ [class]p3:
2591 // If a class is marked final and it appears as a base-type-specifier in
2592 // base-clause, the program is ill-formed.
2593 if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2594 Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2595 << CXXBaseDecl->getDeclName()
2596 << FA->isSpelledAsSealed();
2597 Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2598 << CXXBaseDecl->getDeclName() << FA->getRange();
2599 return nullptr;
2600 }
2601
2602 if (BaseDecl->isInvalidDecl())
2603 Class->setInvalidDecl();
2604
2605 // Create the base specifier.
2606 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2607 Class->getTagKind() == TTK_Class,
2608 Access, TInfo, EllipsisLoc);
2609 }
2610
2611 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2612 /// one entry in the base class list of a class specifier, for
2613 /// example:
2614 /// class foo : public bar, virtual private baz {
2615 /// 'public bar' and 'virtual private baz' are each base-specifiers.
2616 BaseResult
ActOnBaseSpecifier(Decl * classdecl,SourceRange SpecifierRange,ParsedAttributes & Attributes,bool Virtual,AccessSpecifier Access,ParsedType basetype,SourceLocation BaseLoc,SourceLocation EllipsisLoc)2617 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2618 ParsedAttributes &Attributes,
2619 bool Virtual, AccessSpecifier Access,
2620 ParsedType basetype, SourceLocation BaseLoc,
2621 SourceLocation EllipsisLoc) {
2622 if (!classdecl)
2623 return true;
2624
2625 AdjustDeclIfTemplate(classdecl);
2626 CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2627 if (!Class)
2628 return true;
2629
2630 // We haven't yet attached the base specifiers.
2631 Class->setIsParsingBaseSpecifiers();
2632
2633 // We do not support any C++11 attributes on base-specifiers yet.
2634 // Diagnose any attributes we see.
2635 for (const ParsedAttr &AL : Attributes) {
2636 if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2637 continue;
2638 Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2639 ? (unsigned)diag::warn_unknown_attribute_ignored
2640 : (unsigned)diag::err_base_specifier_attribute)
2641 << AL << AL.getRange();
2642 }
2643
2644 TypeSourceInfo *TInfo = nullptr;
2645 GetTypeFromParser(basetype, &TInfo);
2646
2647 if (EllipsisLoc.isInvalid() &&
2648 DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2649 UPPC_BaseType))
2650 return true;
2651
2652 if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2653 Virtual, Access, TInfo,
2654 EllipsisLoc))
2655 return BaseSpec;
2656 else
2657 Class->setInvalidDecl();
2658
2659 return true;
2660 }
2661
2662 /// Use small set to collect indirect bases. As this is only used
2663 /// locally, there's no need to abstract the small size parameter.
2664 typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2665
2666 /// Recursively add the bases of Type. Don't add Type itself.
2667 static void
NoteIndirectBases(ASTContext & Context,IndirectBaseSet & Set,const QualType & Type)2668 NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2669 const QualType &Type)
2670 {
2671 // Even though the incoming type is a base, it might not be
2672 // a class -- it could be a template parm, for instance.
2673 if (auto Rec = Type->getAs<RecordType>()) {
2674 auto Decl = Rec->getAsCXXRecordDecl();
2675
2676 // Iterate over its bases.
2677 for (const auto &BaseSpec : Decl->bases()) {
2678 QualType Base = Context.getCanonicalType(BaseSpec.getType())
2679 .getUnqualifiedType();
2680 if (Set.insert(Base).second)
2681 // If we've not already seen it, recurse.
2682 NoteIndirectBases(Context, Set, Base);
2683 }
2684 }
2685 }
2686
2687 /// Performs the actual work of attaching the given base class
2688 /// specifiers to a C++ class.
AttachBaseSpecifiers(CXXRecordDecl * Class,MutableArrayRef<CXXBaseSpecifier * > Bases)2689 bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
2690 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2691 if (Bases.empty())
2692 return false;
2693
2694 // Used to keep track of which base types we have already seen, so
2695 // that we can properly diagnose redundant direct base types. Note
2696 // that the key is always the unqualified canonical type of the base
2697 // class.
2698 std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2699
2700 // Used to track indirect bases so we can see if a direct base is
2701 // ambiguous.
2702 IndirectBaseSet IndirectBaseTypes;
2703
2704 // Copy non-redundant base specifiers into permanent storage.
2705 unsigned NumGoodBases = 0;
2706 bool Invalid = false;
2707 for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2708 QualType NewBaseType
2709 = Context.getCanonicalType(Bases[idx]->getType());
2710 NewBaseType = NewBaseType.getLocalUnqualifiedType();
2711
2712 CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2713 if (KnownBase) {
2714 // C++ [class.mi]p3:
2715 // A class shall not be specified as a direct base class of a
2716 // derived class more than once.
2717 Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2718 << KnownBase->getType() << Bases[idx]->getSourceRange();
2719
2720 // Delete the duplicate base class specifier; we're going to
2721 // overwrite its pointer later.
2722 Context.Deallocate(Bases[idx]);
2723
2724 Invalid = true;
2725 } else {
2726 // Okay, add this new base class.
2727 KnownBase = Bases[idx];
2728 Bases[NumGoodBases++] = Bases[idx];
2729
2730 // Note this base's direct & indirect bases, if there could be ambiguity.
2731 if (Bases.size() > 1)
2732 NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2733
2734 if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2735 const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2736 if (Class->isInterface() &&
2737 (!RD->isInterfaceLike() ||
2738 KnownBase->getAccessSpecifier() != AS_public)) {
2739 // The Microsoft extension __interface does not permit bases that
2740 // are not themselves public interfaces.
2741 Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2742 << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2743 << RD->getSourceRange();
2744 Invalid = true;
2745 }
2746 if (RD->hasAttr<WeakAttr>())
2747 Class->addAttr(WeakAttr::CreateImplicit(Context));
2748 }
2749 }
2750 }
2751
2752 // Attach the remaining base class specifiers to the derived class.
2753 Class->setBases(Bases.data(), NumGoodBases);
2754
2755 // Check that the only base classes that are duplicate are virtual.
2756 for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2757 // Check whether this direct base is inaccessible due to ambiguity.
2758 QualType BaseType = Bases[idx]->getType();
2759
2760 // Skip all dependent types in templates being used as base specifiers.
2761 // Checks below assume that the base specifier is a CXXRecord.
2762 if (BaseType->isDependentType())
2763 continue;
2764
2765 CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2766 .getUnqualifiedType();
2767
2768 if (IndirectBaseTypes.count(CanonicalBase)) {
2769 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2770 /*DetectVirtual=*/true);
2771 bool found
2772 = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2773 assert(found);
2774 (void)found;
2775
2776 if (Paths.isAmbiguous(CanonicalBase))
2777 Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2778 << BaseType << getAmbiguousPathsDisplayString(Paths)
2779 << Bases[idx]->getSourceRange();
2780 else
2781 assert(Bases[idx]->isVirtual());
2782 }
2783
2784 // Delete the base class specifier, since its data has been copied
2785 // into the CXXRecordDecl.
2786 Context.Deallocate(Bases[idx]);
2787 }
2788
2789 return Invalid;
2790 }
2791
2792 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
2793 /// class, after checking whether there are any duplicate base
2794 /// classes.
ActOnBaseSpecifiers(Decl * ClassDecl,MutableArrayRef<CXXBaseSpecifier * > Bases)2795 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2796 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2797 if (!ClassDecl || Bases.empty())
2798 return;
2799
2800 AdjustDeclIfTemplate(ClassDecl);
2801 AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2802 }
2803
2804 /// Determine whether the type \p Derived is a C++ class that is
2805 /// derived from the type \p Base.
IsDerivedFrom(SourceLocation Loc,QualType Derived,QualType Base)2806 bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
2807 if (!getLangOpts().CPlusPlus)
2808 return false;
2809
2810 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2811 if (!DerivedRD)
2812 return false;
2813
2814 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2815 if (!BaseRD)
2816 return false;
2817
2818 // If either the base or the derived type is invalid, don't try to
2819 // check whether one is derived from the other.
2820 if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2821 return false;
2822
2823 // FIXME: In a modules build, do we need the entire path to be visible for us
2824 // to be able to use the inheritance relationship?
2825 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2826 return false;
2827
2828 return DerivedRD->isDerivedFrom(BaseRD);
2829 }
2830
2831 /// Determine whether the type \p Derived is a C++ class that is
2832 /// derived from the type \p Base.
IsDerivedFrom(SourceLocation Loc,QualType Derived,QualType Base,CXXBasePaths & Paths)2833 bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
2834 CXXBasePaths &Paths) {
2835 if (!getLangOpts().CPlusPlus)
2836 return false;
2837
2838 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2839 if (!DerivedRD)
2840 return false;
2841
2842 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2843 if (!BaseRD)
2844 return false;
2845
2846 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2847 return false;
2848
2849 return DerivedRD->isDerivedFrom(BaseRD, Paths);
2850 }
2851
BuildBasePathArray(const CXXBasePath & Path,CXXCastPath & BasePathArray)2852 static void BuildBasePathArray(const CXXBasePath &Path,
2853 CXXCastPath &BasePathArray) {
2854 // We first go backward and check if we have a virtual base.
2855 // FIXME: It would be better if CXXBasePath had the base specifier for
2856 // the nearest virtual base.
2857 unsigned Start = 0;
2858 for (unsigned I = Path.size(); I != 0; --I) {
2859 if (Path[I - 1].Base->isVirtual()) {
2860 Start = I - 1;
2861 break;
2862 }
2863 }
2864
2865 // Now add all bases.
2866 for (unsigned I = Start, E = Path.size(); I != E; ++I)
2867 BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2868 }
2869
2870
BuildBasePathArray(const CXXBasePaths & Paths,CXXCastPath & BasePathArray)2871 void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
2872 CXXCastPath &BasePathArray) {
2873 assert(BasePathArray.empty() && "Base path array must be empty!");
2874 assert(Paths.isRecordingPaths() && "Must record paths!");
2875 return ::BuildBasePathArray(Paths.front(), BasePathArray);
2876 }
2877 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2878 /// conversion (where Derived and Base are class types) is
2879 /// well-formed, meaning that the conversion is unambiguous (and
2880 /// that all of the base classes are accessible). Returns true
2881 /// and emits a diagnostic if the code is ill-formed, returns false
2882 /// otherwise. Loc is the location where this routine should point to
2883 /// if there is an error, and Range is the source range to highlight
2884 /// if there is an error.
2885 ///
2886 /// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the
2887 /// diagnostic for the respective type of error will be suppressed, but the
2888 /// check for ill-formed code will still be performed.
2889 bool
CheckDerivedToBaseConversion(QualType Derived,QualType Base,unsigned InaccessibleBaseID,unsigned AmbiguousBaseConvID,SourceLocation Loc,SourceRange Range,DeclarationName Name,CXXCastPath * BasePath,bool IgnoreAccess)2890 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2891 unsigned InaccessibleBaseID,
2892 unsigned AmbiguousBaseConvID,
2893 SourceLocation Loc, SourceRange Range,
2894 DeclarationName Name,
2895 CXXCastPath *BasePath,
2896 bool IgnoreAccess) {
2897 // First, determine whether the path from Derived to Base is
2898 // ambiguous. This is slightly more expensive than checking whether
2899 // the Derived to Base conversion exists, because here we need to
2900 // explore multiple paths to determine if there is an ambiguity.
2901 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2902 /*DetectVirtual=*/false);
2903 bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2904 if (!DerivationOkay)
2905 return true;
2906
2907 const CXXBasePath *Path = nullptr;
2908 if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2909 Path = &Paths.front();
2910
2911 // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2912 // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2913 // user to access such bases.
2914 if (!Path && getLangOpts().MSVCCompat) {
2915 for (const CXXBasePath &PossiblePath : Paths) {
2916 if (PossiblePath.size() == 1) {
2917 Path = &PossiblePath;
2918 if (AmbiguousBaseConvID)
2919 Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2920 << Base << Derived << Range;
2921 break;
2922 }
2923 }
2924 }
2925
2926 if (Path) {
2927 if (!IgnoreAccess) {
2928 // Check that the base class can be accessed.
2929 switch (
2930 CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2931 case AR_inaccessible:
2932 return true;
2933 case AR_accessible:
2934 case AR_dependent:
2935 case AR_delayed:
2936 break;
2937 }
2938 }
2939
2940 // Build a base path if necessary.
2941 if (BasePath)
2942 ::BuildBasePathArray(*Path, *BasePath);
2943 return false;
2944 }
2945
2946 if (AmbiguousBaseConvID) {
2947 // We know that the derived-to-base conversion is ambiguous, and
2948 // we're going to produce a diagnostic. Perform the derived-to-base
2949 // search just one more time to compute all of the possible paths so
2950 // that we can print them out. This is more expensive than any of
2951 // the previous derived-to-base checks we've done, but at this point
2952 // performance isn't as much of an issue.
2953 Paths.clear();
2954 Paths.setRecordingPaths(true);
2955 bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2956 assert(StillOkay && "Can only be used with a derived-to-base conversion");
2957 (void)StillOkay;
2958
2959 // Build up a textual representation of the ambiguous paths, e.g.,
2960 // D -> B -> A, that will be used to illustrate the ambiguous
2961 // conversions in the diagnostic. We only print one of the paths
2962 // to each base class subobject.
2963 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2964
2965 Diag(Loc, AmbiguousBaseConvID)
2966 << Derived << Base << PathDisplayStr << Range << Name;
2967 }
2968 return true;
2969 }
2970
2971 bool
CheckDerivedToBaseConversion(QualType Derived,QualType Base,SourceLocation Loc,SourceRange Range,CXXCastPath * BasePath,bool IgnoreAccess)2972 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2973 SourceLocation Loc, SourceRange Range,
2974 CXXCastPath *BasePath,
2975 bool IgnoreAccess) {
2976 return CheckDerivedToBaseConversion(
2977 Derived, Base, diag::err_upcast_to_inaccessible_base,
2978 diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2979 BasePath, IgnoreAccess);
2980 }
2981
2982
2983 /// Builds a string representing ambiguous paths from a
2984 /// specific derived class to different subobjects of the same base
2985 /// class.
2986 ///
2987 /// This function builds a string that can be used in error messages
2988 /// to show the different paths that one can take through the
2989 /// inheritance hierarchy to go from the derived class to different
2990 /// subobjects of a base class. The result looks something like this:
2991 /// @code
2992 /// struct D -> struct B -> struct A
2993 /// struct D -> struct C -> struct A
2994 /// @endcode
getAmbiguousPathsDisplayString(CXXBasePaths & Paths)2995 std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
2996 std::string PathDisplayStr;
2997 std::set<unsigned> DisplayedPaths;
2998 for (CXXBasePaths::paths_iterator Path = Paths.begin();
2999 Path != Paths.end(); ++Path) {
3000 if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
3001 // We haven't displayed a path to this particular base
3002 // class subobject yet.
3003 PathDisplayStr += "\n ";
3004 PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
3005 for (CXXBasePath::const_iterator Element = Path->begin();
3006 Element != Path->end(); ++Element)
3007 PathDisplayStr += " -> " + Element->Base->getType().getAsString();
3008 }
3009 }
3010
3011 return PathDisplayStr;
3012 }
3013
3014 //===----------------------------------------------------------------------===//
3015 // C++ class member Handling
3016 //===----------------------------------------------------------------------===//
3017
3018 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
ActOnAccessSpecifier(AccessSpecifier Access,SourceLocation ASLoc,SourceLocation ColonLoc,const ParsedAttributesView & Attrs)3019 bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
3020 SourceLocation ColonLoc,
3021 const ParsedAttributesView &Attrs) {
3022 assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
3023 AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
3024 ASLoc, ColonLoc);
3025 CurContext->addHiddenDecl(ASDecl);
3026 return ProcessAccessDeclAttributeList(ASDecl, Attrs);
3027 }
3028
3029 /// CheckOverrideControl - Check C++11 override control semantics.
CheckOverrideControl(NamedDecl * D)3030 void Sema::CheckOverrideControl(NamedDecl *D) {
3031 if (D->isInvalidDecl())
3032 return;
3033
3034 // We only care about "override" and "final" declarations.
3035 if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
3036 return;
3037
3038 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3039
3040 // We can't check dependent instance methods.
3041 if (MD && MD->isInstance() &&
3042 (MD->getParent()->hasAnyDependentBases() ||
3043 MD->getType()->isDependentType()))
3044 return;
3045
3046 if (MD && !MD->isVirtual()) {
3047 // If we have a non-virtual method, check if if hides a virtual method.
3048 // (In that case, it's most likely the method has the wrong type.)
3049 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
3050 FindHiddenVirtualMethods(MD, OverloadedMethods);
3051
3052 if (!OverloadedMethods.empty()) {
3053 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3054 Diag(OA->getLocation(),
3055 diag::override_keyword_hides_virtual_member_function)
3056 << "override" << (OverloadedMethods.size() > 1);
3057 } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3058 Diag(FA->getLocation(),
3059 diag::override_keyword_hides_virtual_member_function)
3060 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3061 << (OverloadedMethods.size() > 1);
3062 }
3063 NoteHiddenVirtualMethods(MD, OverloadedMethods);
3064 MD->setInvalidDecl();
3065 return;
3066 }
3067 // Fall through into the general case diagnostic.
3068 // FIXME: We might want to attempt typo correction here.
3069 }
3070
3071 if (!MD || !MD->isVirtual()) {
3072 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3073 Diag(OA->getLocation(),
3074 diag::override_keyword_only_allowed_on_virtual_member_functions)
3075 << "override" << FixItHint::CreateRemoval(OA->getLocation());
3076 D->dropAttr<OverrideAttr>();
3077 }
3078 if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3079 Diag(FA->getLocation(),
3080 diag::override_keyword_only_allowed_on_virtual_member_functions)
3081 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3082 << FixItHint::CreateRemoval(FA->getLocation());
3083 D->dropAttr<FinalAttr>();
3084 }
3085 return;
3086 }
3087
3088 // C++11 [class.virtual]p5:
3089 // If a function is marked with the virt-specifier override and
3090 // does not override a member function of a base class, the program is
3091 // ill-formed.
3092 bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
3093 if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
3094 Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
3095 << MD->getDeclName();
3096 }
3097
DiagnoseAbsenceOfOverrideControl(NamedDecl * D,bool Inconsistent)3098 void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) {
3099 if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
3100 return;
3101 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3102 if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
3103 return;
3104
3105 SourceLocation Loc = MD->getLocation();
3106 SourceLocation SpellingLoc = Loc;
3107 if (getSourceManager().isMacroArgExpansion(Loc))
3108 SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
3109 SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
3110 if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
3111 return;
3112
3113 if (MD->size_overridden_methods() > 0) {
3114 auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) {
3115 unsigned DiagID =
3116 Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation())
3117 ? DiagInconsistent
3118 : DiagSuggest;
3119 Diag(MD->getLocation(), DiagID) << MD->getDeclName();
3120 const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
3121 Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
3122 };
3123 if (isa<CXXDestructorDecl>(MD))
3124 EmitDiag(
3125 diag::warn_inconsistent_destructor_marked_not_override_overriding,
3126 diag::warn_suggest_destructor_marked_not_override_overriding);
3127 else
3128 EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding,
3129 diag::warn_suggest_function_marked_not_override_overriding);
3130 }
3131 }
3132
3133 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3134 /// function overrides a virtual member function marked 'final', according to
3135 /// C++11 [class.virtual]p4.
CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl * New,const CXXMethodDecl * Old)3136 bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
3137 const CXXMethodDecl *Old) {
3138 FinalAttr *FA = Old->getAttr<FinalAttr>();
3139 if (!FA)
3140 return false;
3141
3142 Diag(New->getLocation(), diag::err_final_function_overridden)
3143 << New->getDeclName()
3144 << FA->isSpelledAsSealed();
3145 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3146 return true;
3147 }
3148
InitializationHasSideEffects(const FieldDecl & FD)3149 static bool InitializationHasSideEffects(const FieldDecl &FD) {
3150 const Type *T = FD.getType()->getBaseElementTypeUnsafe();
3151 // FIXME: Destruction of ObjC lifetime types has side-effects.
3152 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3153 return !RD->isCompleteDefinition() ||
3154 !RD->hasTrivialDefaultConstructor() ||
3155 !RD->hasTrivialDestructor();
3156 return false;
3157 }
3158
getMSPropertyAttr(const ParsedAttributesView & list)3159 static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
3160 ParsedAttributesView::const_iterator Itr =
3161 llvm::find_if(list, [](const ParsedAttr &AL) {
3162 return AL.isDeclspecPropertyAttribute();
3163 });
3164 if (Itr != list.end())
3165 return &*Itr;
3166 return nullptr;
3167 }
3168
3169 // Check if there is a field shadowing.
CheckShadowInheritedFields(const SourceLocation & Loc,DeclarationName FieldName,const CXXRecordDecl * RD,bool DeclIsField)3170 void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
3171 DeclarationName FieldName,
3172 const CXXRecordDecl *RD,
3173 bool DeclIsField) {
3174 if (Diags.isIgnored(diag::warn_shadow_field, Loc))
3175 return;
3176
3177 // To record a shadowed field in a base
3178 std::map<CXXRecordDecl*, NamedDecl*> Bases;
3179 auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
3180 CXXBasePath &Path) {
3181 const auto Base = Specifier->getType()->getAsCXXRecordDecl();
3182 // Record an ambiguous path directly
3183 if (Bases.find(Base) != Bases.end())
3184 return true;
3185 for (const auto Field : Base->lookup(FieldName)) {
3186 if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
3187 Field->getAccess() != AS_private) {
3188 assert(Field->getAccess() != AS_none);
3189 assert(Bases.find(Base) == Bases.end());
3190 Bases[Base] = Field;
3191 return true;
3192 }
3193 }
3194 return false;
3195 };
3196
3197 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3198 /*DetectVirtual=*/true);
3199 if (!RD->lookupInBases(FieldShadowed, Paths))
3200 return;
3201
3202 for (const auto &P : Paths) {
3203 auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
3204 auto It = Bases.find(Base);
3205 // Skip duplicated bases
3206 if (It == Bases.end())
3207 continue;
3208 auto BaseField = It->second;
3209 assert(BaseField->getAccess() != AS_private);
3210 if (AS_none !=
3211 CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
3212 Diag(Loc, diag::warn_shadow_field)
3213 << FieldName << RD << Base << DeclIsField;
3214 Diag(BaseField->getLocation(), diag::note_shadow_field);
3215 Bases.erase(It);
3216 }
3217 }
3218 }
3219
3220 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3221 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3222 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
3223 /// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3224 /// present (but parsing it has been deferred).
3225 NamedDecl *
ActOnCXXMemberDeclarator(Scope * S,AccessSpecifier AS,Declarator & D,MultiTemplateParamsArg TemplateParameterLists,Expr * BW,const VirtSpecifiers & VS,InClassInitStyle InitStyle)3226 Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
3227 MultiTemplateParamsArg TemplateParameterLists,
3228 Expr *BW, const VirtSpecifiers &VS,
3229 InClassInitStyle InitStyle) {
3230 const DeclSpec &DS = D.getDeclSpec();
3231 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
3232 DeclarationName Name = NameInfo.getName();
3233 SourceLocation Loc = NameInfo.getLoc();
3234
3235 // For anonymous bitfields, the location should point to the type.
3236 if (Loc.isInvalid())
3237 Loc = D.getBeginLoc();
3238
3239 Expr *BitWidth = static_cast<Expr*>(BW);
3240
3241 assert(isa<CXXRecordDecl>(CurContext));
3242 assert(!DS.isFriendSpecified());
3243
3244 bool isFunc = D.isDeclarationOfFunction();
3245 const ParsedAttr *MSPropertyAttr =
3246 getMSPropertyAttr(D.getDeclSpec().getAttributes());
3247
3248 if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
3249 // The Microsoft extension __interface only permits public member functions
3250 // and prohibits constructors, destructors, operators, non-public member
3251 // functions, static methods and data members.
3252 unsigned InvalidDecl;
3253 bool ShowDeclName = true;
3254 if (!isFunc &&
3255 (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
3256 InvalidDecl = 0;
3257 else if (!isFunc)
3258 InvalidDecl = 1;
3259 else if (AS != AS_public)
3260 InvalidDecl = 2;
3261 else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
3262 InvalidDecl = 3;
3263 else switch (Name.getNameKind()) {
3264 case DeclarationName::CXXConstructorName:
3265 InvalidDecl = 4;
3266 ShowDeclName = false;
3267 break;
3268
3269 case DeclarationName::CXXDestructorName:
3270 InvalidDecl = 5;
3271 ShowDeclName = false;
3272 break;
3273
3274 case DeclarationName::CXXOperatorName:
3275 case DeclarationName::CXXConversionFunctionName:
3276 InvalidDecl = 6;
3277 break;
3278
3279 default:
3280 InvalidDecl = 0;
3281 break;
3282 }
3283
3284 if (InvalidDecl) {
3285 if (ShowDeclName)
3286 Diag(Loc, diag::err_invalid_member_in_interface)
3287 << (InvalidDecl-1) << Name;
3288 else
3289 Diag(Loc, diag::err_invalid_member_in_interface)
3290 << (InvalidDecl-1) << "";
3291 return nullptr;
3292 }
3293 }
3294
3295 // C++ 9.2p6: A member shall not be declared to have automatic storage
3296 // duration (auto, register) or with the extern storage-class-specifier.
3297 // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
3298 // data members and cannot be applied to names declared const or static,
3299 // and cannot be applied to reference members.
3300 switch (DS.getStorageClassSpec()) {
3301 case DeclSpec::SCS_unspecified:
3302 case DeclSpec::SCS_typedef:
3303 case DeclSpec::SCS_static:
3304 break;
3305 case DeclSpec::SCS_mutable:
3306 if (isFunc) {
3307 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
3308
3309 // FIXME: It would be nicer if the keyword was ignored only for this
3310 // declarator. Otherwise we could get follow-up errors.
3311 D.getMutableDeclSpec().ClearStorageClassSpecs();
3312 }
3313 break;
3314 default:
3315 Diag(DS.getStorageClassSpecLoc(),
3316 diag::err_storageclass_invalid_for_member);
3317 D.getMutableDeclSpec().ClearStorageClassSpecs();
3318 break;
3319 }
3320
3321 bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
3322 DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
3323 !isFunc);
3324
3325 if (DS.hasConstexprSpecifier() && isInstField) {
3326 SemaDiagnosticBuilder B =
3327 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
3328 SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
3329 if (InitStyle == ICIS_NoInit) {
3330 B << 0 << 0;
3331 if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
3332 B << FixItHint::CreateRemoval(ConstexprLoc);
3333 else {
3334 B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3335 D.getMutableDeclSpec().ClearConstexprSpec();
3336 const char *PrevSpec;
3337 unsigned DiagID;
3338 bool Failed = D.getMutableDeclSpec().SetTypeQual(
3339 DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3340 (void)Failed;
3341 assert(!Failed && "Making a constexpr member const shouldn't fail");
3342 }
3343 } else {
3344 B << 1;
3345 const char *PrevSpec;
3346 unsigned DiagID;
3347 if (D.getMutableDeclSpec().SetStorageClassSpec(
3348 *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3349 Context.getPrintingPolicy())) {
3350 assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
3351 "This is the only DeclSpec that should fail to be applied");
3352 B << 1;
3353 } else {
3354 B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3355 isInstField = false;
3356 }
3357 }
3358 }
3359
3360 NamedDecl *Member;
3361 if (isInstField) {
3362 CXXScopeSpec &SS = D.getCXXScopeSpec();
3363
3364 // Data members must have identifiers for names.
3365 if (!Name.isIdentifier()) {
3366 Diag(Loc, diag::err_bad_variable_name)
3367 << Name;
3368 return nullptr;
3369 }
3370
3371 IdentifierInfo *II = Name.getAsIdentifierInfo();
3372
3373 // Member field could not be with "template" keyword.
3374 // So TemplateParameterLists should be empty in this case.
3375 if (TemplateParameterLists.size()) {
3376 TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3377 if (TemplateParams->size()) {
3378 // There is no such thing as a member field template.
3379 Diag(D.getIdentifierLoc(), diag::err_template_member)
3380 << II
3381 << SourceRange(TemplateParams->getTemplateLoc(),
3382 TemplateParams->getRAngleLoc());
3383 } else {
3384 // There is an extraneous 'template<>' for this member.
3385 Diag(TemplateParams->getTemplateLoc(),
3386 diag::err_template_member_noparams)
3387 << II
3388 << SourceRange(TemplateParams->getTemplateLoc(),
3389 TemplateParams->getRAngleLoc());
3390 }
3391 return nullptr;
3392 }
3393
3394 if (SS.isSet() && !SS.isInvalid()) {
3395 // The user provided a superfluous scope specifier inside a class
3396 // definition:
3397 //
3398 // class X {
3399 // int X::member;
3400 // };
3401 if (DeclContext *DC = computeDeclContext(SS, false))
3402 diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3403 D.getName().getKind() ==
3404 UnqualifiedIdKind::IK_TemplateId);
3405 else
3406 Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3407 << Name << SS.getRange();
3408
3409 SS.clear();
3410 }
3411
3412 if (MSPropertyAttr) {
3413 Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3414 BitWidth, InitStyle, AS, *MSPropertyAttr);
3415 if (!Member)
3416 return nullptr;
3417 isInstField = false;
3418 } else {
3419 Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3420 BitWidth, InitStyle, AS);
3421 if (!Member)
3422 return nullptr;
3423 }
3424
3425 CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3426 } else {
3427 Member = HandleDeclarator(S, D, TemplateParameterLists);
3428 if (!Member)
3429 return nullptr;
3430
3431 // Non-instance-fields can't have a bitfield.
3432 if (BitWidth) {
3433 if (Member->isInvalidDecl()) {
3434 // don't emit another diagnostic.
3435 } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3436 // C++ 9.6p3: A bit-field shall not be a static member.
3437 // "static member 'A' cannot be a bit-field"
3438 Diag(Loc, diag::err_static_not_bitfield)
3439 << Name << BitWidth->getSourceRange();
3440 } else if (isa<TypedefDecl>(Member)) {
3441 // "typedef member 'x' cannot be a bit-field"
3442 Diag(Loc, diag::err_typedef_not_bitfield)
3443 << Name << BitWidth->getSourceRange();
3444 } else {
3445 // A function typedef ("typedef int f(); f a;").
3446 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3447 Diag(Loc, diag::err_not_integral_type_bitfield)
3448 << Name << cast<ValueDecl>(Member)->getType()
3449 << BitWidth->getSourceRange();
3450 }
3451
3452 BitWidth = nullptr;
3453 Member->setInvalidDecl();
3454 }
3455
3456 NamedDecl *NonTemplateMember = Member;
3457 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3458 NonTemplateMember = FunTmpl->getTemplatedDecl();
3459 else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3460 NonTemplateMember = VarTmpl->getTemplatedDecl();
3461
3462 Member->setAccess(AS);
3463
3464 // If we have declared a member function template or static data member
3465 // template, set the access of the templated declaration as well.
3466 if (NonTemplateMember != Member)
3467 NonTemplateMember->setAccess(AS);
3468
3469 // C++ [temp.deduct.guide]p3:
3470 // A deduction guide [...] for a member class template [shall be
3471 // declared] with the same access [as the template].
3472 if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3473 auto *TD = DG->getDeducedTemplate();
3474 // Access specifiers are only meaningful if both the template and the
3475 // deduction guide are from the same scope.
3476 if (AS != TD->getAccess() &&
3477 TD->getDeclContext()->getRedeclContext()->Equals(
3478 DG->getDeclContext()->getRedeclContext())) {
3479 Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3480 Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3481 << TD->getAccess();
3482 const AccessSpecDecl *LastAccessSpec = nullptr;
3483 for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3484 if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3485 LastAccessSpec = AccessSpec;
3486 }
3487 assert(LastAccessSpec && "differing access with no access specifier");
3488 Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3489 << AS;
3490 }
3491 }
3492 }
3493
3494 if (VS.isOverrideSpecified())
3495 Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
3496 AttributeCommonInfo::AS_Keyword));
3497 if (VS.isFinalSpecified())
3498 Member->addAttr(FinalAttr::Create(
3499 Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
3500 static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));
3501
3502 if (VS.getLastLocation().isValid()) {
3503 // Update the end location of a method that has a virt-specifiers.
3504 if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3505 MD->setRangeEnd(VS.getLastLocation());
3506 }
3507
3508 CheckOverrideControl(Member);
3509
3510 assert((Name || isInstField) && "No identifier for non-field ?");
3511
3512 if (isInstField) {
3513 FieldDecl *FD = cast<FieldDecl>(Member);
3514 FieldCollector->Add(FD);
3515
3516 if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3517 // Remember all explicit private FieldDecls that have a name, no side
3518 // effects and are not part of a dependent type declaration.
3519 if (!FD->isImplicit() && FD->getDeclName() &&
3520 FD->getAccess() == AS_private &&
3521 !FD->hasAttr<UnusedAttr>() &&
3522 !FD->getParent()->isDependentContext() &&
3523 !InitializationHasSideEffects(*FD))
3524 UnusedPrivateFields.insert(FD);
3525 }
3526 }
3527
3528 return Member;
3529 }
3530
3531 namespace {
3532 class UninitializedFieldVisitor
3533 : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3534 Sema &S;
3535 // List of Decls to generate a warning on. Also remove Decls that become
3536 // initialized.
3537 llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3538 // List of base classes of the record. Classes are removed after their
3539 // initializers.
3540 llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3541 // Vector of decls to be removed from the Decl set prior to visiting the
3542 // nodes. These Decls may have been initialized in the prior initializer.
3543 llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3544 // If non-null, add a note to the warning pointing back to the constructor.
3545 const CXXConstructorDecl *Constructor;
3546 // Variables to hold state when processing an initializer list. When
3547 // InitList is true, special case initialization of FieldDecls matching
3548 // InitListFieldDecl.
3549 bool InitList;
3550 FieldDecl *InitListFieldDecl;
3551 llvm::SmallVector<unsigned, 4> InitFieldIndex;
3552
3553 public:
3554 typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
UninitializedFieldVisitor(Sema & S,llvm::SmallPtrSetImpl<ValueDecl * > & Decls,llvm::SmallPtrSetImpl<QualType> & BaseClasses)3555 UninitializedFieldVisitor(Sema &S,
3556 llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3557 llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3558 : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3559 Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3560
3561 // Returns true if the use of ME is not an uninitialized use.
IsInitListMemberExprInitialized(MemberExpr * ME,bool CheckReferenceOnly)3562 bool IsInitListMemberExprInitialized(MemberExpr *ME,
3563 bool CheckReferenceOnly) {
3564 llvm::SmallVector<FieldDecl*, 4> Fields;
3565 bool ReferenceField = false;
3566 while (ME) {
3567 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3568 if (!FD)
3569 return false;
3570 Fields.push_back(FD);
3571 if (FD->getType()->isReferenceType())
3572 ReferenceField = true;
3573 ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3574 }
3575
3576 // Binding a reference to an uninitialized field is not an
3577 // uninitialized use.
3578 if (CheckReferenceOnly && !ReferenceField)
3579 return true;
3580
3581 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3582 // Discard the first field since it is the field decl that is being
3583 // initialized.
3584 for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3585 UsedFieldIndex.push_back((*I)->getFieldIndex());
3586 }
3587
3588 for (auto UsedIter = UsedFieldIndex.begin(),
3589 UsedEnd = UsedFieldIndex.end(),
3590 OrigIter = InitFieldIndex.begin(),
3591 OrigEnd = InitFieldIndex.end();
3592 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3593 if (*UsedIter < *OrigIter)
3594 return true;
3595 if (*UsedIter > *OrigIter)
3596 break;
3597 }
3598
3599 return false;
3600 }
3601
HandleMemberExpr(MemberExpr * ME,bool CheckReferenceOnly,bool AddressOf)3602 void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3603 bool AddressOf) {
3604 if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3605 return;
3606
3607 // FieldME is the inner-most MemberExpr that is not an anonymous struct
3608 // or union.
3609 MemberExpr *FieldME = ME;
3610
3611 bool AllPODFields = FieldME->getType().isPODType(S.Context);
3612
3613 Expr *Base = ME;
3614 while (MemberExpr *SubME =
3615 dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3616
3617 if (isa<VarDecl>(SubME->getMemberDecl()))
3618 return;
3619
3620 if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3621 if (!FD->isAnonymousStructOrUnion())
3622 FieldME = SubME;
3623
3624 if (!FieldME->getType().isPODType(S.Context))
3625 AllPODFields = false;
3626
3627 Base = SubME->getBase();
3628 }
3629
3630 if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) {
3631 Visit(Base);
3632 return;
3633 }
3634
3635 if (AddressOf && AllPODFields)
3636 return;
3637
3638 ValueDecl* FoundVD = FieldME->getMemberDecl();
3639
3640 if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3641 while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3642 BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3643 }
3644
3645 if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3646 QualType T = BaseCast->getType();
3647 if (T->isPointerType() &&
3648 BaseClasses.count(T->getPointeeType())) {
3649 S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3650 << T->getPointeeType() << FoundVD;
3651 }
3652 }
3653 }
3654
3655 if (!Decls.count(FoundVD))
3656 return;
3657
3658 const bool IsReference = FoundVD->getType()->isReferenceType();
3659
3660 if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3661 // Special checking for initializer lists.
3662 if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3663 return;
3664 }
3665 } else {
3666 // Prevent double warnings on use of unbounded references.
3667 if (CheckReferenceOnly && !IsReference)
3668 return;
3669 }
3670
3671 unsigned diag = IsReference
3672 ? diag::warn_reference_field_is_uninit
3673 : diag::warn_field_is_uninit;
3674 S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3675 if (Constructor)
3676 S.Diag(Constructor->getLocation(),
3677 diag::note_uninit_in_this_constructor)
3678 << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3679
3680 }
3681
HandleValue(Expr * E,bool AddressOf)3682 void HandleValue(Expr *E, bool AddressOf) {
3683 E = E->IgnoreParens();
3684
3685 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3686 HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3687 AddressOf /*AddressOf*/);
3688 return;
3689 }
3690
3691 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3692 Visit(CO->getCond());
3693 HandleValue(CO->getTrueExpr(), AddressOf);
3694 HandleValue(CO->getFalseExpr(), AddressOf);
3695 return;
3696 }
3697
3698 if (BinaryConditionalOperator *BCO =
3699 dyn_cast<BinaryConditionalOperator>(E)) {
3700 Visit(BCO->getCond());
3701 HandleValue(BCO->getFalseExpr(), AddressOf);
3702 return;
3703 }
3704
3705 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3706 HandleValue(OVE->getSourceExpr(), AddressOf);
3707 return;
3708 }
3709
3710 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3711 switch (BO->getOpcode()) {
3712 default:
3713 break;
3714 case(BO_PtrMemD):
3715 case(BO_PtrMemI):
3716 HandleValue(BO->getLHS(), AddressOf);
3717 Visit(BO->getRHS());
3718 return;
3719 case(BO_Comma):
3720 Visit(BO->getLHS());
3721 HandleValue(BO->getRHS(), AddressOf);
3722 return;
3723 }
3724 }
3725
3726 Visit(E);
3727 }
3728
CheckInitListExpr(InitListExpr * ILE)3729 void CheckInitListExpr(InitListExpr *ILE) {
3730 InitFieldIndex.push_back(0);
3731 for (auto Child : ILE->children()) {
3732 if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3733 CheckInitListExpr(SubList);
3734 } else {
3735 Visit(Child);
3736 }
3737 ++InitFieldIndex.back();
3738 }
3739 InitFieldIndex.pop_back();
3740 }
3741
CheckInitializer(Expr * E,const CXXConstructorDecl * FieldConstructor,FieldDecl * Field,const Type * BaseClass)3742 void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3743 FieldDecl *Field, const Type *BaseClass) {
3744 // Remove Decls that may have been initialized in the previous
3745 // initializer.
3746 for (ValueDecl* VD : DeclsToRemove)
3747 Decls.erase(VD);
3748 DeclsToRemove.clear();
3749
3750 Constructor = FieldConstructor;
3751 InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3752
3753 if (ILE && Field) {
3754 InitList = true;
3755 InitListFieldDecl = Field;
3756 InitFieldIndex.clear();
3757 CheckInitListExpr(ILE);
3758 } else {
3759 InitList = false;
3760 Visit(E);
3761 }
3762
3763 if (Field)
3764 Decls.erase(Field);
3765 if (BaseClass)
3766 BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3767 }
3768
VisitMemberExpr(MemberExpr * ME)3769 void VisitMemberExpr(MemberExpr *ME) {
3770 // All uses of unbounded reference fields will warn.
3771 HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3772 }
3773
VisitImplicitCastExpr(ImplicitCastExpr * E)3774 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3775 if (E->getCastKind() == CK_LValueToRValue) {
3776 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3777 return;
3778 }
3779
3780 Inherited::VisitImplicitCastExpr(E);
3781 }
3782
VisitCXXConstructExpr(CXXConstructExpr * E)3783 void VisitCXXConstructExpr(CXXConstructExpr *E) {
3784 if (E->getConstructor()->isCopyConstructor()) {
3785 Expr *ArgExpr = E->getArg(0);
3786 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3787 if (ILE->getNumInits() == 1)
3788 ArgExpr = ILE->getInit(0);
3789 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3790 if (ICE->getCastKind() == CK_NoOp)
3791 ArgExpr = ICE->getSubExpr();
3792 HandleValue(ArgExpr, false /*AddressOf*/);
3793 return;
3794 }
3795 Inherited::VisitCXXConstructExpr(E);
3796 }
3797
VisitCXXMemberCallExpr(CXXMemberCallExpr * E)3798 void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3799 Expr *Callee = E->getCallee();
3800 if (isa<MemberExpr>(Callee)) {
3801 HandleValue(Callee, false /*AddressOf*/);
3802 for (auto Arg : E->arguments())
3803 Visit(Arg);
3804 return;
3805 }
3806
3807 Inherited::VisitCXXMemberCallExpr(E);
3808 }
3809
VisitCallExpr(CallExpr * E)3810 void VisitCallExpr(CallExpr *E) {
3811 // Treat std::move as a use.
3812 if (E->isCallToStdMove()) {
3813 HandleValue(E->getArg(0), /*AddressOf=*/false);
3814 return;
3815 }
3816
3817 Inherited::VisitCallExpr(E);
3818 }
3819
VisitCXXOperatorCallExpr(CXXOperatorCallExpr * E)3820 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3821 Expr *Callee = E->getCallee();
3822
3823 if (isa<UnresolvedLookupExpr>(Callee))
3824 return Inherited::VisitCXXOperatorCallExpr(E);
3825
3826 Visit(Callee);
3827 for (auto Arg : E->arguments())
3828 HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3829 }
3830
VisitBinaryOperator(BinaryOperator * E)3831 void VisitBinaryOperator(BinaryOperator *E) {
3832 // If a field assignment is detected, remove the field from the
3833 // uninitiailized field set.
3834 if (E->getOpcode() == BO_Assign)
3835 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3836 if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3837 if (!FD->getType()->isReferenceType())
3838 DeclsToRemove.push_back(FD);
3839
3840 if (E->isCompoundAssignmentOp()) {
3841 HandleValue(E->getLHS(), false /*AddressOf*/);
3842 Visit(E->getRHS());
3843 return;
3844 }
3845
3846 Inherited::VisitBinaryOperator(E);
3847 }
3848
VisitUnaryOperator(UnaryOperator * E)3849 void VisitUnaryOperator(UnaryOperator *E) {
3850 if (E->isIncrementDecrementOp()) {
3851 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3852 return;
3853 }
3854 if (E->getOpcode() == UO_AddrOf) {
3855 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3856 HandleValue(ME->getBase(), true /*AddressOf*/);
3857 return;
3858 }
3859 }
3860
3861 Inherited::VisitUnaryOperator(E);
3862 }
3863 };
3864
3865 // Diagnose value-uses of fields to initialize themselves, e.g.
3866 // foo(foo)
3867 // where foo is not also a parameter to the constructor.
3868 // Also diagnose across field uninitialized use such as
3869 // x(y), y(x)
3870 // TODO: implement -Wuninitialized and fold this into that framework.
DiagnoseUninitializedFields(Sema & SemaRef,const CXXConstructorDecl * Constructor)3871 static void DiagnoseUninitializedFields(
3872 Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3873
3874 if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3875 Constructor->getLocation())) {
3876 return;
3877 }
3878
3879 if (Constructor->isInvalidDecl())
3880 return;
3881
3882 const CXXRecordDecl *RD = Constructor->getParent();
3883
3884 if (RD->isDependentContext())
3885 return;
3886
3887 // Holds fields that are uninitialized.
3888 llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3889
3890 // At the beginning, all fields are uninitialized.
3891 for (auto *I : RD->decls()) {
3892 if (auto *FD = dyn_cast<FieldDecl>(I)) {
3893 UninitializedFields.insert(FD);
3894 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3895 UninitializedFields.insert(IFD->getAnonField());
3896 }
3897 }
3898
3899 llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3900 for (auto I : RD->bases())
3901 UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3902
3903 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3904 return;
3905
3906 UninitializedFieldVisitor UninitializedChecker(SemaRef,
3907 UninitializedFields,
3908 UninitializedBaseClasses);
3909
3910 for (const auto *FieldInit : Constructor->inits()) {
3911 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3912 break;
3913
3914 Expr *InitExpr = FieldInit->getInit();
3915 if (!InitExpr)
3916 continue;
3917
3918 if (CXXDefaultInitExpr *Default =
3919 dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3920 InitExpr = Default->getExpr();
3921 if (!InitExpr)
3922 continue;
3923 // In class initializers will point to the constructor.
3924 UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3925 FieldInit->getAnyMember(),
3926 FieldInit->getBaseClass());
3927 } else {
3928 UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3929 FieldInit->getAnyMember(),
3930 FieldInit->getBaseClass());
3931 }
3932 }
3933 }
3934 } // namespace
3935
3936 /// Enter a new C++ default initializer scope. After calling this, the
3937 /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3938 /// parsing or instantiating the initializer failed.
ActOnStartCXXInClassMemberInitializer()3939 void Sema::ActOnStartCXXInClassMemberInitializer() {
3940 // Create a synthetic function scope to represent the call to the constructor
3941 // that notionally surrounds a use of this initializer.
3942 PushFunctionScope();
3943 }
3944
ActOnStartTrailingRequiresClause(Scope * S,Declarator & D)3945 void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
3946 if (!D.isFunctionDeclarator())
3947 return;
3948 auto &FTI = D.getFunctionTypeInfo();
3949 if (!FTI.Params)
3950 return;
3951 for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
3952 FTI.NumParams)) {
3953 auto *ParamDecl = cast<NamedDecl>(Param.Param);
3954 if (ParamDecl->getDeclName())
3955 PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
3956 }
3957 }
3958
ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr)3959 ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
3960 return ActOnRequiresClause(ConstraintExpr);
3961 }
3962
ActOnRequiresClause(ExprResult ConstraintExpr)3963 ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
3964 if (ConstraintExpr.isInvalid())
3965 return ExprError();
3966
3967 ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
3968 if (ConstraintExpr.isInvalid())
3969 return ExprError();
3970
3971 if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
3972 UPPC_RequiresClause))
3973 return ExprError();
3974
3975 return ConstraintExpr;
3976 }
3977
3978 /// This is invoked after parsing an in-class initializer for a
3979 /// non-static C++ class member, and after instantiating an in-class initializer
3980 /// in a class template. Such actions are deferred until the class is complete.
ActOnFinishCXXInClassMemberInitializer(Decl * D,SourceLocation InitLoc,Expr * InitExpr)3981 void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
3982 SourceLocation InitLoc,
3983 Expr *InitExpr) {
3984 // Pop the notional constructor scope we created earlier.
3985 PopFunctionScopeInfo(nullptr, D);
3986
3987 FieldDecl *FD = dyn_cast<FieldDecl>(D);
3988 assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
3989 "must set init style when field is created");
3990
3991 if (!InitExpr) {
3992 D->setInvalidDecl();
3993 if (FD)
3994 FD->removeInClassInitializer();
3995 return;
3996 }
3997
3998 if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
3999 FD->setInvalidDecl();
4000 FD->removeInClassInitializer();
4001 return;
4002 }
4003
4004 ExprResult Init = InitExpr;
4005 if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
4006 InitializedEntity Entity =
4007 InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
4008 InitializationKind Kind =
4009 FD->getInClassInitStyle() == ICIS_ListInit
4010 ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
4011 InitExpr->getBeginLoc(),
4012 InitExpr->getEndLoc())
4013 : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
4014 InitializationSequence Seq(*this, Entity, Kind, InitExpr);
4015 Init = Seq.Perform(*this, Entity, Kind, InitExpr);
4016 if (Init.isInvalid()) {
4017 FD->setInvalidDecl();
4018 return;
4019 }
4020 }
4021
4022 // C++11 [class.base.init]p7:
4023 // The initialization of each base and member constitutes a
4024 // full-expression.
4025 Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
4026 if (Init.isInvalid()) {
4027 FD->setInvalidDecl();
4028 return;
4029 }
4030
4031 InitExpr = Init.get();
4032
4033 FD->setInClassInitializer(InitExpr);
4034 }
4035
4036 /// Find the direct and/or virtual base specifiers that
4037 /// correspond to the given base type, for use in base initialization
4038 /// within a constructor.
FindBaseInitializer(Sema & SemaRef,CXXRecordDecl * ClassDecl,QualType BaseType,const CXXBaseSpecifier * & DirectBaseSpec,const CXXBaseSpecifier * & VirtualBaseSpec)4039 static bool FindBaseInitializer(Sema &SemaRef,
4040 CXXRecordDecl *ClassDecl,
4041 QualType BaseType,
4042 const CXXBaseSpecifier *&DirectBaseSpec,
4043 const CXXBaseSpecifier *&VirtualBaseSpec) {
4044 // First, check for a direct base class.
4045 DirectBaseSpec = nullptr;
4046 for (const auto &Base : ClassDecl->bases()) {
4047 if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
4048 // We found a direct base of this type. That's what we're
4049 // initializing.
4050 DirectBaseSpec = &Base;
4051 break;
4052 }
4053 }
4054
4055 // Check for a virtual base class.
4056 // FIXME: We might be able to short-circuit this if we know in advance that
4057 // there are no virtual bases.
4058 VirtualBaseSpec = nullptr;
4059 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
4060 // We haven't found a base yet; search the class hierarchy for a
4061 // virtual base class.
4062 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
4063 /*DetectVirtual=*/false);
4064 if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
4065 SemaRef.Context.getTypeDeclType(ClassDecl),
4066 BaseType, Paths)) {
4067 for (CXXBasePaths::paths_iterator Path = Paths.begin();
4068 Path != Paths.end(); ++Path) {
4069 if (Path->back().Base->isVirtual()) {
4070 VirtualBaseSpec = Path->back().Base;
4071 break;
4072 }
4073 }
4074 }
4075 }
4076
4077 return DirectBaseSpec || VirtualBaseSpec;
4078 }
4079
4080 /// Handle a C++ member initializer using braced-init-list syntax.
4081 MemInitResult
ActOnMemInitializer(Decl * ConstructorD,Scope * S,CXXScopeSpec & SS,IdentifierInfo * MemberOrBase,ParsedType TemplateTypeTy,const DeclSpec & DS,SourceLocation IdLoc,Expr * InitList,SourceLocation EllipsisLoc)4082 Sema::ActOnMemInitializer(Decl *ConstructorD,
4083 Scope *S,
4084 CXXScopeSpec &SS,
4085 IdentifierInfo *MemberOrBase,
4086 ParsedType TemplateTypeTy,
4087 const DeclSpec &DS,
4088 SourceLocation IdLoc,
4089 Expr *InitList,
4090 SourceLocation EllipsisLoc) {
4091 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4092 DS, IdLoc, InitList,
4093 EllipsisLoc);
4094 }
4095
4096 /// Handle a C++ member initializer using parentheses syntax.
4097 MemInitResult
ActOnMemInitializer(Decl * ConstructorD,Scope * S,CXXScopeSpec & SS,IdentifierInfo * MemberOrBase,ParsedType TemplateTypeTy,const DeclSpec & DS,SourceLocation IdLoc,SourceLocation LParenLoc,ArrayRef<Expr * > Args,SourceLocation RParenLoc,SourceLocation EllipsisLoc)4098 Sema::ActOnMemInitializer(Decl *ConstructorD,
4099 Scope *S,
4100 CXXScopeSpec &SS,
4101 IdentifierInfo *MemberOrBase,
4102 ParsedType TemplateTypeTy,
4103 const DeclSpec &DS,
4104 SourceLocation IdLoc,
4105 SourceLocation LParenLoc,
4106 ArrayRef<Expr *> Args,
4107 SourceLocation RParenLoc,
4108 SourceLocation EllipsisLoc) {
4109 Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
4110 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4111 DS, IdLoc, List, EllipsisLoc);
4112 }
4113
4114 namespace {
4115
4116 // Callback to only accept typo corrections that can be a valid C++ member
4117 // intializer: either a non-static field member or a base class.
4118 class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4119 public:
MemInitializerValidatorCCC(CXXRecordDecl * ClassDecl)4120 explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
4121 : ClassDecl(ClassDecl) {}
4122
ValidateCandidate(const TypoCorrection & candidate)4123 bool ValidateCandidate(const TypoCorrection &candidate) override {
4124 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
4125 if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
4126 return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
4127 return isa<TypeDecl>(ND);
4128 }
4129 return false;
4130 }
4131
clone()4132 std::unique_ptr<CorrectionCandidateCallback> clone() override {
4133 return std::make_unique<MemInitializerValidatorCCC>(*this);
4134 }
4135
4136 private:
4137 CXXRecordDecl *ClassDecl;
4138 };
4139
4140 }
4141
tryLookupCtorInitMemberDecl(CXXRecordDecl * ClassDecl,CXXScopeSpec & SS,ParsedType TemplateTypeTy,IdentifierInfo * MemberOrBase)4142 ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
4143 CXXScopeSpec &SS,
4144 ParsedType TemplateTypeTy,
4145 IdentifierInfo *MemberOrBase) {
4146 if (SS.getScopeRep() || TemplateTypeTy)
4147 return nullptr;
4148 for (auto *D : ClassDecl->lookup(MemberOrBase))
4149 if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
4150 return cast<ValueDecl>(D);
4151 return nullptr;
4152 }
4153
4154 /// Handle a C++ member initializer.
4155 MemInitResult
BuildMemInitializer(Decl * ConstructorD,Scope * S,CXXScopeSpec & SS,IdentifierInfo * MemberOrBase,ParsedType TemplateTypeTy,const DeclSpec & DS,SourceLocation IdLoc,Expr * Init,SourceLocation EllipsisLoc)4156 Sema::BuildMemInitializer(Decl *ConstructorD,
4157 Scope *S,
4158 CXXScopeSpec &SS,
4159 IdentifierInfo *MemberOrBase,
4160 ParsedType TemplateTypeTy,
4161 const DeclSpec &DS,
4162 SourceLocation IdLoc,
4163 Expr *Init,
4164 SourceLocation EllipsisLoc) {
4165 ExprResult Res = CorrectDelayedTyposInExpr(Init);
4166 if (!Res.isUsable())
4167 return true;
4168 Init = Res.get();
4169
4170 if (!ConstructorD)
4171 return true;
4172
4173 AdjustDeclIfTemplate(ConstructorD);
4174
4175 CXXConstructorDecl *Constructor
4176 = dyn_cast<CXXConstructorDecl>(ConstructorD);
4177 if (!Constructor) {
4178 // The user wrote a constructor initializer on a function that is
4179 // not a C++ constructor. Ignore the error for now, because we may
4180 // have more member initializers coming; we'll diagnose it just
4181 // once in ActOnMemInitializers.
4182 return true;
4183 }
4184
4185 CXXRecordDecl *ClassDecl = Constructor->getParent();
4186
4187 // C++ [class.base.init]p2:
4188 // Names in a mem-initializer-id are looked up in the scope of the
4189 // constructor's class and, if not found in that scope, are looked
4190 // up in the scope containing the constructor's definition.
4191 // [Note: if the constructor's class contains a member with the
4192 // same name as a direct or virtual base class of the class, a
4193 // mem-initializer-id naming the member or base class and composed
4194 // of a single identifier refers to the class member. A
4195 // mem-initializer-id for the hidden base class may be specified
4196 // using a qualified name. ]
4197
4198 // Look for a member, first.
4199 if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
4200 ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
4201 if (EllipsisLoc.isValid())
4202 Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
4203 << MemberOrBase
4204 << SourceRange(IdLoc, Init->getSourceRange().getEnd());
4205
4206 return BuildMemberInitializer(Member, Init, IdLoc);
4207 }
4208 // It didn't name a member, so see if it names a class.
4209 QualType BaseType;
4210 TypeSourceInfo *TInfo = nullptr;
4211
4212 if (TemplateTypeTy) {
4213 BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
4214 if (BaseType.isNull())
4215 return true;
4216 } else if (DS.getTypeSpecType() == TST_decltype) {
4217 BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
4218 } else if (DS.getTypeSpecType() == TST_decltype_auto) {
4219 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
4220 return true;
4221 } else {
4222 LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
4223 LookupParsedName(R, S, &SS);
4224
4225 TypeDecl *TyD = R.getAsSingle<TypeDecl>();
4226 if (!TyD) {
4227 if (R.isAmbiguous()) return true;
4228
4229 // We don't want access-control diagnostics here.
4230 R.suppressDiagnostics();
4231
4232 if (SS.isSet() && isDependentScopeSpecifier(SS)) {
4233 bool NotUnknownSpecialization = false;
4234 DeclContext *DC = computeDeclContext(SS, false);
4235 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
4236 NotUnknownSpecialization = !Record->hasAnyDependentBases();
4237
4238 if (!NotUnknownSpecialization) {
4239 // When the scope specifier can refer to a member of an unknown
4240 // specialization, we take it as a type name.
4241 BaseType = CheckTypenameType(ETK_None, SourceLocation(),
4242 SS.getWithLocInContext(Context),
4243 *MemberOrBase, IdLoc);
4244 if (BaseType.isNull())
4245 return true;
4246
4247 TInfo = Context.CreateTypeSourceInfo(BaseType);
4248 DependentNameTypeLoc TL =
4249 TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
4250 if (!TL.isNull()) {
4251 TL.setNameLoc(IdLoc);
4252 TL.setElaboratedKeywordLoc(SourceLocation());
4253 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4254 }
4255
4256 R.clear();
4257 R.setLookupName(MemberOrBase);
4258 }
4259 }
4260
4261 // If no results were found, try to correct typos.
4262 TypoCorrection Corr;
4263 MemInitializerValidatorCCC CCC(ClassDecl);
4264 if (R.empty() && BaseType.isNull() &&
4265 (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
4266 CCC, CTK_ErrorRecovery, ClassDecl))) {
4267 if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
4268 // We have found a non-static data member with a similar
4269 // name to what was typed; complain and initialize that
4270 // member.
4271 diagnoseTypo(Corr,
4272 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4273 << MemberOrBase << true);
4274 return BuildMemberInitializer(Member, Init, IdLoc);
4275 } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
4276 const CXXBaseSpecifier *DirectBaseSpec;
4277 const CXXBaseSpecifier *VirtualBaseSpec;
4278 if (FindBaseInitializer(*this, ClassDecl,
4279 Context.getTypeDeclType(Type),
4280 DirectBaseSpec, VirtualBaseSpec)) {
4281 // We have found a direct or virtual base class with a
4282 // similar name to what was typed; complain and initialize
4283 // that base class.
4284 diagnoseTypo(Corr,
4285 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4286 << MemberOrBase << false,
4287 PDiag() /*Suppress note, we provide our own.*/);
4288
4289 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
4290 : VirtualBaseSpec;
4291 Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
4292 << BaseSpec->getType() << BaseSpec->getSourceRange();
4293
4294 TyD = Type;
4295 }
4296 }
4297 }
4298
4299 if (!TyD && BaseType.isNull()) {
4300 Diag(IdLoc, diag::err_mem_init_not_member_or_class)
4301 << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
4302 return true;
4303 }
4304 }
4305
4306 if (BaseType.isNull()) {
4307 BaseType = Context.getTypeDeclType(TyD);
4308 MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
4309 if (SS.isSet()) {
4310 BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
4311 BaseType);
4312 TInfo = Context.CreateTypeSourceInfo(BaseType);
4313 ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
4314 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
4315 TL.setElaboratedKeywordLoc(SourceLocation());
4316 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4317 }
4318 }
4319 }
4320
4321 if (!TInfo)
4322 TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
4323
4324 return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4325 }
4326
4327 MemInitResult
BuildMemberInitializer(ValueDecl * Member,Expr * Init,SourceLocation IdLoc)4328 Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
4329 SourceLocation IdLoc) {
4330 FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
4331 IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
4332 assert((DirectMember || IndirectMember) &&
4333 "Member must be a FieldDecl or IndirectFieldDecl");
4334
4335 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4336 return true;
4337
4338 if (Member->isInvalidDecl())
4339 return true;
4340
4341 MultiExprArg Args;
4342 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4343 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4344 } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4345 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4346 } else {
4347 // Template instantiation doesn't reconstruct ParenListExprs for us.
4348 Args = Init;
4349 }
4350
4351 SourceRange InitRange = Init->getSourceRange();
4352
4353 if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4354 // Can't check initialization for a member of dependent type or when
4355 // any of the arguments are type-dependent expressions.
4356 DiscardCleanupsInEvaluationContext();
4357 } else {
4358 bool InitList = false;
4359 if (isa<InitListExpr>(Init)) {
4360 InitList = true;
4361 Args = Init;
4362 }
4363
4364 // Initialize the member.
4365 InitializedEntity MemberEntity =
4366 DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4367 : InitializedEntity::InitializeMember(IndirectMember,
4368 nullptr);
4369 InitializationKind Kind =
4370 InitList ? InitializationKind::CreateDirectList(
4371 IdLoc, Init->getBeginLoc(), Init->getEndLoc())
4372 : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4373 InitRange.getEnd());
4374
4375 InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4376 ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4377 nullptr);
4378 if (MemberInit.isInvalid())
4379 return true;
4380
4381 // C++11 [class.base.init]p7:
4382 // The initialization of each base and member constitutes a
4383 // full-expression.
4384 MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
4385 /*DiscardedValue*/ false);
4386 if (MemberInit.isInvalid())
4387 return true;
4388
4389 Init = MemberInit.get();
4390 }
4391
4392 if (DirectMember) {
4393 return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4394 InitRange.getBegin(), Init,
4395 InitRange.getEnd());
4396 } else {
4397 return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4398 InitRange.getBegin(), Init,
4399 InitRange.getEnd());
4400 }
4401 }
4402
4403 MemInitResult
BuildDelegatingInitializer(TypeSourceInfo * TInfo,Expr * Init,CXXRecordDecl * ClassDecl)4404 Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
4405 CXXRecordDecl *ClassDecl) {
4406 SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4407 if (!LangOpts.CPlusPlus11)
4408 return Diag(NameLoc, diag::err_delegating_ctor)
4409 << TInfo->getTypeLoc().getLocalSourceRange();
4410 Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4411
4412 bool InitList = true;
4413 MultiExprArg Args = Init;
4414 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4415 InitList = false;
4416 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4417 }
4418
4419 SourceRange InitRange = Init->getSourceRange();
4420 // Initialize the object.
4421 InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
4422 QualType(ClassDecl->getTypeForDecl(), 0));
4423 InitializationKind Kind =
4424 InitList ? InitializationKind::CreateDirectList(
4425 NameLoc, Init->getBeginLoc(), Init->getEndLoc())
4426 : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4427 InitRange.getEnd());
4428 InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4429 ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4430 Args, nullptr);
4431 if (DelegationInit.isInvalid())
4432 return true;
4433
4434 assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
4435 "Delegating constructor with no target?");
4436
4437 // C++11 [class.base.init]p7:
4438 // The initialization of each base and member constitutes a
4439 // full-expression.
4440 DelegationInit = ActOnFinishFullExpr(
4441 DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
4442 if (DelegationInit.isInvalid())
4443 return true;
4444
4445 // If we are in a dependent context, template instantiation will
4446 // perform this type-checking again. Just save the arguments that we
4447 // received in a ParenListExpr.
4448 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4449 // of the information that we have about the base
4450 // initializer. However, deconstructing the ASTs is a dicey process,
4451 // and this approach is far more likely to get the corner cases right.
4452 if (CurContext->isDependentContext())
4453 DelegationInit = Init;
4454
4455 return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4456 DelegationInit.getAs<Expr>(),
4457 InitRange.getEnd());
4458 }
4459
4460 MemInitResult
BuildBaseInitializer(QualType BaseType,TypeSourceInfo * BaseTInfo,Expr * Init,CXXRecordDecl * ClassDecl,SourceLocation EllipsisLoc)4461 Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
4462 Expr *Init, CXXRecordDecl *ClassDecl,
4463 SourceLocation EllipsisLoc) {
4464 SourceLocation BaseLoc
4465 = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4466
4467 if (!BaseType->isDependentType() && !BaseType->isRecordType())
4468 return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4469 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4470
4471 // C++ [class.base.init]p2:
4472 // [...] Unless the mem-initializer-id names a nonstatic data
4473 // member of the constructor's class or a direct or virtual base
4474 // of that class, the mem-initializer is ill-formed. A
4475 // mem-initializer-list can initialize a base class using any
4476 // name that denotes that base class type.
4477 bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
4478
4479 SourceRange InitRange = Init->getSourceRange();
4480 if (EllipsisLoc.isValid()) {
4481 // This is a pack expansion.
4482 if (!BaseType->containsUnexpandedParameterPack()) {
4483 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4484 << SourceRange(BaseLoc, InitRange.getEnd());
4485
4486 EllipsisLoc = SourceLocation();
4487 }
4488 } else {
4489 // Check for any unexpanded parameter packs.
4490 if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4491 return true;
4492
4493 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4494 return true;
4495 }
4496
4497 // Check for direct and virtual base classes.
4498 const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4499 const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4500 if (!Dependent) {
4501 if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4502 BaseType))
4503 return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4504
4505 FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4506 VirtualBaseSpec);
4507
4508 // C++ [base.class.init]p2:
4509 // Unless the mem-initializer-id names a nonstatic data member of the
4510 // constructor's class or a direct or virtual base of that class, the
4511 // mem-initializer is ill-formed.
4512 if (!DirectBaseSpec && !VirtualBaseSpec) {
4513 // If the class has any dependent bases, then it's possible that
4514 // one of those types will resolve to the same type as
4515 // BaseType. Therefore, just treat this as a dependent base
4516 // class initialization. FIXME: Should we try to check the
4517 // initialization anyway? It seems odd.
4518 if (ClassDecl->hasAnyDependentBases())
4519 Dependent = true;
4520 else
4521 return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4522 << BaseType << Context.getTypeDeclType(ClassDecl)
4523 << BaseTInfo->getTypeLoc().getLocalSourceRange();
4524 }
4525 }
4526
4527 if (Dependent) {
4528 DiscardCleanupsInEvaluationContext();
4529
4530 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4531 /*IsVirtual=*/false,
4532 InitRange.getBegin(), Init,
4533 InitRange.getEnd(), EllipsisLoc);
4534 }
4535
4536 // C++ [base.class.init]p2:
4537 // If a mem-initializer-id is ambiguous because it designates both
4538 // a direct non-virtual base class and an inherited virtual base
4539 // class, the mem-initializer is ill-formed.
4540 if (DirectBaseSpec && VirtualBaseSpec)
4541 return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4542 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4543
4544 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4545 if (!BaseSpec)
4546 BaseSpec = VirtualBaseSpec;
4547
4548 // Initialize the base.
4549 bool InitList = true;
4550 MultiExprArg Args = Init;
4551 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4552 InitList = false;
4553 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4554 }
4555
4556 InitializedEntity BaseEntity =
4557 InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4558 InitializationKind Kind =
4559 InitList ? InitializationKind::CreateDirectList(BaseLoc)
4560 : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4561 InitRange.getEnd());
4562 InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4563 ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4564 if (BaseInit.isInvalid())
4565 return true;
4566
4567 // C++11 [class.base.init]p7:
4568 // The initialization of each base and member constitutes a
4569 // full-expression.
4570 BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
4571 /*DiscardedValue*/ false);
4572 if (BaseInit.isInvalid())
4573 return true;
4574
4575 // If we are in a dependent context, template instantiation will
4576 // perform this type-checking again. Just save the arguments that we
4577 // received in a ParenListExpr.
4578 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4579 // of the information that we have about the base
4580 // initializer. However, deconstructing the ASTs is a dicey process,
4581 // and this approach is far more likely to get the corner cases right.
4582 if (CurContext->isDependentContext())
4583 BaseInit = Init;
4584
4585 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4586 BaseSpec->isVirtual(),
4587 InitRange.getBegin(),
4588 BaseInit.getAs<Expr>(),
4589 InitRange.getEnd(), EllipsisLoc);
4590 }
4591
4592 // Create a static_cast\<T&&>(expr).
CastForMoving(Sema & SemaRef,Expr * E,QualType T=QualType ())4593 static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4594 if (T.isNull()) T = E->getType();
4595 QualType TargetType = SemaRef.BuildReferenceType(
4596 T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4597 SourceLocation ExprLoc = E->getBeginLoc();
4598 TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4599 TargetType, ExprLoc);
4600
4601 return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4602 SourceRange(ExprLoc, ExprLoc),
4603 E->getSourceRange()).get();
4604 }
4605
4606 /// ImplicitInitializerKind - How an implicit base or member initializer should
4607 /// initialize its base or member.
4608 enum ImplicitInitializerKind {
4609 IIK_Default,
4610 IIK_Copy,
4611 IIK_Move,
4612 IIK_Inherit
4613 };
4614
4615 static bool
BuildImplicitBaseInitializer(Sema & SemaRef,CXXConstructorDecl * Constructor,ImplicitInitializerKind ImplicitInitKind,CXXBaseSpecifier * BaseSpec,bool IsInheritedVirtualBase,CXXCtorInitializer * & CXXBaseInit)4616 BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4617 ImplicitInitializerKind ImplicitInitKind,
4618 CXXBaseSpecifier *BaseSpec,
4619 bool IsInheritedVirtualBase,
4620 CXXCtorInitializer *&CXXBaseInit) {
4621 InitializedEntity InitEntity
4622 = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4623 IsInheritedVirtualBase);
4624
4625 ExprResult BaseInit;
4626
4627 switch (ImplicitInitKind) {
4628 case IIK_Inherit:
4629 case IIK_Default: {
4630 InitializationKind InitKind
4631 = InitializationKind::CreateDefault(Constructor->getLocation());
4632 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4633 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4634 break;
4635 }
4636
4637 case IIK_Move:
4638 case IIK_Copy: {
4639 bool Moving = ImplicitInitKind == IIK_Move;
4640 ParmVarDecl *Param = Constructor->getParamDecl(0);
4641 QualType ParamType = Param->getType().getNonReferenceType();
4642
4643 Expr *CopyCtorArg =
4644 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4645 SourceLocation(), Param, false,
4646 Constructor->getLocation(), ParamType,
4647 VK_LValue, nullptr);
4648
4649 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4650
4651 // Cast to the base class to avoid ambiguities.
4652 QualType ArgTy =
4653 SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4654 ParamType.getQualifiers());
4655
4656 if (Moving) {
4657 CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4658 }
4659
4660 CXXCastPath BasePath;
4661 BasePath.push_back(BaseSpec);
4662 CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4663 CK_UncheckedDerivedToBase,
4664 Moving ? VK_XValue : VK_LValue,
4665 &BasePath).get();
4666
4667 InitializationKind InitKind
4668 = InitializationKind::CreateDirect(Constructor->getLocation(),
4669 SourceLocation(), SourceLocation());
4670 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4671 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4672 break;
4673 }
4674 }
4675
4676 BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4677 if (BaseInit.isInvalid())
4678 return true;
4679
4680 CXXBaseInit =
4681 new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4682 SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4683 SourceLocation()),
4684 BaseSpec->isVirtual(),
4685 SourceLocation(),
4686 BaseInit.getAs<Expr>(),
4687 SourceLocation(),
4688 SourceLocation());
4689
4690 return false;
4691 }
4692
RefersToRValueRef(Expr * MemRef)4693 static bool RefersToRValueRef(Expr *MemRef) {
4694 ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4695 return Referenced->getType()->isRValueReferenceType();
4696 }
4697
4698 static bool
BuildImplicitMemberInitializer(Sema & SemaRef,CXXConstructorDecl * Constructor,ImplicitInitializerKind ImplicitInitKind,FieldDecl * Field,IndirectFieldDecl * Indirect,CXXCtorInitializer * & CXXMemberInit)4699 BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4700 ImplicitInitializerKind ImplicitInitKind,
4701 FieldDecl *Field, IndirectFieldDecl *Indirect,
4702 CXXCtorInitializer *&CXXMemberInit) {
4703 if (Field->isInvalidDecl())
4704 return true;
4705
4706 SourceLocation Loc = Constructor->getLocation();
4707
4708 if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4709 bool Moving = ImplicitInitKind == IIK_Move;
4710 ParmVarDecl *Param = Constructor->getParamDecl(0);
4711 QualType ParamType = Param->getType().getNonReferenceType();
4712
4713 // Suppress copying zero-width bitfields.
4714 if (Field->isZeroLengthBitField(SemaRef.Context))
4715 return false;
4716
4717 Expr *MemberExprBase =
4718 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4719 SourceLocation(), Param, false,
4720 Loc, ParamType, VK_LValue, nullptr);
4721
4722 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4723
4724 if (Moving) {
4725 MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4726 }
4727
4728 // Build a reference to this field within the parameter.
4729 CXXScopeSpec SS;
4730 LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4731 Sema::LookupMemberName);
4732 MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4733 : cast<ValueDecl>(Field), AS_public);
4734 MemberLookup.resolveKind();
4735 ExprResult CtorArg
4736 = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4737 ParamType, Loc,
4738 /*IsArrow=*/false,
4739 SS,
4740 /*TemplateKWLoc=*/SourceLocation(),
4741 /*FirstQualifierInScope=*/nullptr,
4742 MemberLookup,
4743 /*TemplateArgs=*/nullptr,
4744 /*S*/nullptr);
4745 if (CtorArg.isInvalid())
4746 return true;
4747
4748 // C++11 [class.copy]p15:
4749 // - if a member m has rvalue reference type T&&, it is direct-initialized
4750 // with static_cast<T&&>(x.m);
4751 if (RefersToRValueRef(CtorArg.get())) {
4752 CtorArg = CastForMoving(SemaRef, CtorArg.get());
4753 }
4754
4755 InitializedEntity Entity =
4756 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4757 /*Implicit*/ true)
4758 : InitializedEntity::InitializeMember(Field, nullptr,
4759 /*Implicit*/ true);
4760
4761 // Direct-initialize to use the copy constructor.
4762 InitializationKind InitKind =
4763 InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
4764
4765 Expr *CtorArgE = CtorArg.getAs<Expr>();
4766 InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4767 ExprResult MemberInit =
4768 InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4769 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4770 if (MemberInit.isInvalid())
4771 return true;
4772
4773 if (Indirect)
4774 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4775 SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4776 else
4777 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4778 SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4779 return false;
4780 }
4781
4782 assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&
4783 "Unhandled implicit init kind!");
4784
4785 QualType FieldBaseElementType =
4786 SemaRef.Context.getBaseElementType(Field->getType());
4787
4788 if (FieldBaseElementType->isRecordType()) {
4789 InitializedEntity InitEntity =
4790 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4791 /*Implicit*/ true)
4792 : InitializedEntity::InitializeMember(Field, nullptr,
4793 /*Implicit*/ true);
4794 InitializationKind InitKind =
4795 InitializationKind::CreateDefault(Loc);
4796
4797 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4798 ExprResult MemberInit =
4799 InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4800
4801 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4802 if (MemberInit.isInvalid())
4803 return true;
4804
4805 if (Indirect)
4806 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4807 Indirect, Loc,
4808 Loc,
4809 MemberInit.get(),
4810 Loc);
4811 else
4812 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4813 Field, Loc, Loc,
4814 MemberInit.get(),
4815 Loc);
4816 return false;
4817 }
4818
4819 if (!Field->getParent()->isUnion()) {
4820 if (FieldBaseElementType->isReferenceType()) {
4821 SemaRef.Diag(Constructor->getLocation(),
4822 diag::err_uninitialized_member_in_ctor)
4823 << (int)Constructor->isImplicit()
4824 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4825 << 0 << Field->getDeclName();
4826 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4827 return true;
4828 }
4829
4830 if (FieldBaseElementType.isConstQualified()) {
4831 SemaRef.Diag(Constructor->getLocation(),
4832 diag::err_uninitialized_member_in_ctor)
4833 << (int)Constructor->isImplicit()
4834 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4835 << 1 << Field->getDeclName();
4836 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4837 return true;
4838 }
4839 }
4840
4841 if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4842 // ARC and Weak:
4843 // Default-initialize Objective-C pointers to NULL.
4844 CXXMemberInit
4845 = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4846 Loc, Loc,
4847 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4848 Loc);
4849 return false;
4850 }
4851
4852 // Nothing to initialize.
4853 CXXMemberInit = nullptr;
4854 return false;
4855 }
4856
4857 namespace {
4858 struct BaseAndFieldInfo {
4859 Sema &S;
4860 CXXConstructorDecl *Ctor;
4861 bool AnyErrorsInInits;
4862 ImplicitInitializerKind IIK;
4863 llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4864 SmallVector<CXXCtorInitializer*, 8> AllToInit;
4865 llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4866
BaseAndFieldInfo__anonb2a824811211::BaseAndFieldInfo4867 BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4868 : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4869 bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4870 if (Ctor->getInheritedConstructor())
4871 IIK = IIK_Inherit;
4872 else if (Generated && Ctor->isCopyConstructor())
4873 IIK = IIK_Copy;
4874 else if (Generated && Ctor->isMoveConstructor())
4875 IIK = IIK_Move;
4876 else
4877 IIK = IIK_Default;
4878 }
4879
isImplicitCopyOrMove__anonb2a824811211::BaseAndFieldInfo4880 bool isImplicitCopyOrMove() const {
4881 switch (IIK) {
4882 case IIK_Copy:
4883 case IIK_Move:
4884 return true;
4885
4886 case IIK_Default:
4887 case IIK_Inherit:
4888 return false;
4889 }
4890
4891 llvm_unreachable("Invalid ImplicitInitializerKind!");
4892 }
4893
addFieldInitializer__anonb2a824811211::BaseAndFieldInfo4894 bool addFieldInitializer(CXXCtorInitializer *Init) {
4895 AllToInit.push_back(Init);
4896
4897 // Check whether this initializer makes the field "used".
4898 if (Init->getInit()->HasSideEffects(S.Context))
4899 S.UnusedPrivateFields.remove(Init->getAnyMember());
4900
4901 return false;
4902 }
4903
isInactiveUnionMember__anonb2a824811211::BaseAndFieldInfo4904 bool isInactiveUnionMember(FieldDecl *Field) {
4905 RecordDecl *Record = Field->getParent();
4906 if (!Record->isUnion())
4907 return false;
4908
4909 if (FieldDecl *Active =
4910 ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4911 return Active != Field->getCanonicalDecl();
4912
4913 // In an implicit copy or move constructor, ignore any in-class initializer.
4914 if (isImplicitCopyOrMove())
4915 return true;
4916
4917 // If there's no explicit initialization, the field is active only if it
4918 // has an in-class initializer...
4919 if (Field->hasInClassInitializer())
4920 return false;
4921 // ... or it's an anonymous struct or union whose class has an in-class
4922 // initializer.
4923 if (!Field->isAnonymousStructOrUnion())
4924 return true;
4925 CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4926 return !FieldRD->hasInClassInitializer();
4927 }
4928
4929 /// Determine whether the given field is, or is within, a union member
4930 /// that is inactive (because there was an initializer given for a different
4931 /// member of the union, or because the union was not initialized at all).
isWithinInactiveUnionMember__anonb2a824811211::BaseAndFieldInfo4932 bool isWithinInactiveUnionMember(FieldDecl *Field,
4933 IndirectFieldDecl *Indirect) {
4934 if (!Indirect)
4935 return isInactiveUnionMember(Field);
4936
4937 for (auto *C : Indirect->chain()) {
4938 FieldDecl *Field = dyn_cast<FieldDecl>(C);
4939 if (Field && isInactiveUnionMember(Field))
4940 return true;
4941 }
4942 return false;
4943 }
4944 };
4945 }
4946
4947 /// Determine whether the given type is an incomplete or zero-lenfgth
4948 /// array type.
isIncompleteOrZeroLengthArrayType(ASTContext & Context,QualType T)4949 static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
4950 if (T->isIncompleteArrayType())
4951 return true;
4952
4953 while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
4954 if (!ArrayT->getSize())
4955 return true;
4956
4957 T = ArrayT->getElementType();
4958 }
4959
4960 return false;
4961 }
4962
CollectFieldInitializer(Sema & SemaRef,BaseAndFieldInfo & Info,FieldDecl * Field,IndirectFieldDecl * Indirect=nullptr)4963 static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
4964 FieldDecl *Field,
4965 IndirectFieldDecl *Indirect = nullptr) {
4966 if (Field->isInvalidDecl())
4967 return false;
4968
4969 // Overwhelmingly common case: we have a direct initializer for this field.
4970 if (CXXCtorInitializer *Init =
4971 Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
4972 return Info.addFieldInitializer(Init);
4973
4974 // C++11 [class.base.init]p8:
4975 // if the entity is a non-static data member that has a
4976 // brace-or-equal-initializer and either
4977 // -- the constructor's class is a union and no other variant member of that
4978 // union is designated by a mem-initializer-id or
4979 // -- the constructor's class is not a union, and, if the entity is a member
4980 // of an anonymous union, no other member of that union is designated by
4981 // a mem-initializer-id,
4982 // the entity is initialized as specified in [dcl.init].
4983 //
4984 // We also apply the same rules to handle anonymous structs within anonymous
4985 // unions.
4986 if (Info.isWithinInactiveUnionMember(Field, Indirect))
4987 return false;
4988
4989 if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
4990 ExprResult DIE =
4991 SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
4992 if (DIE.isInvalid())
4993 return true;
4994
4995 auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
4996 SemaRef.checkInitializerLifetime(Entity, DIE.get());
4997
4998 CXXCtorInitializer *Init;
4999 if (Indirect)
5000 Init = new (SemaRef.Context)
5001 CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
5002 SourceLocation(), DIE.get(), SourceLocation());
5003 else
5004 Init = new (SemaRef.Context)
5005 CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
5006 SourceLocation(), DIE.get(), SourceLocation());
5007 return Info.addFieldInitializer(Init);
5008 }
5009
5010 // Don't initialize incomplete or zero-length arrays.
5011 if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
5012 return false;
5013
5014 // Don't try to build an implicit initializer if there were semantic
5015 // errors in any of the initializers (and therefore we might be
5016 // missing some that the user actually wrote).
5017 if (Info.AnyErrorsInInits)
5018 return false;
5019
5020 CXXCtorInitializer *Init = nullptr;
5021 if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
5022 Indirect, Init))
5023 return true;
5024
5025 if (!Init)
5026 return false;
5027
5028 return Info.addFieldInitializer(Init);
5029 }
5030
5031 bool
SetDelegatingInitializer(CXXConstructorDecl * Constructor,CXXCtorInitializer * Initializer)5032 Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
5033 CXXCtorInitializer *Initializer) {
5034 assert(Initializer->isDelegatingInitializer());
5035 Constructor->setNumCtorInitializers(1);
5036 CXXCtorInitializer **initializer =
5037 new (Context) CXXCtorInitializer*[1];
5038 memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
5039 Constructor->setCtorInitializers(initializer);
5040
5041 if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
5042 MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
5043 DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
5044 }
5045
5046 DelegatingCtorDecls.push_back(Constructor);
5047
5048 DiagnoseUninitializedFields(*this, Constructor);
5049
5050 return false;
5051 }
5052
SetCtorInitializers(CXXConstructorDecl * Constructor,bool AnyErrors,ArrayRef<CXXCtorInitializer * > Initializers)5053 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
5054 ArrayRef<CXXCtorInitializer *> Initializers) {
5055 if (Constructor->isDependentContext()) {
5056 // Just store the initializers as written, they will be checked during
5057 // instantiation.
5058 if (!Initializers.empty()) {
5059 Constructor->setNumCtorInitializers(Initializers.size());
5060 CXXCtorInitializer **baseOrMemberInitializers =
5061 new (Context) CXXCtorInitializer*[Initializers.size()];
5062 memcpy(baseOrMemberInitializers, Initializers.data(),
5063 Initializers.size() * sizeof(CXXCtorInitializer*));
5064 Constructor->setCtorInitializers(baseOrMemberInitializers);
5065 }
5066
5067 // Let template instantiation know whether we had errors.
5068 if (AnyErrors)
5069 Constructor->setInvalidDecl();
5070
5071 return false;
5072 }
5073
5074 BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
5075
5076 // We need to build the initializer AST according to order of construction
5077 // and not what user specified in the Initializers list.
5078 CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
5079 if (!ClassDecl)
5080 return true;
5081
5082 bool HadError = false;
5083
5084 for (unsigned i = 0; i < Initializers.size(); i++) {
5085 CXXCtorInitializer *Member = Initializers[i];
5086
5087 if (Member->isBaseInitializer())
5088 Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
5089 else {
5090 Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
5091
5092 if (IndirectFieldDecl *F = Member->getIndirectMember()) {
5093 for (auto *C : F->chain()) {
5094 FieldDecl *FD = dyn_cast<FieldDecl>(C);
5095 if (FD && FD->getParent()->isUnion())
5096 Info.ActiveUnionMember.insert(std::make_pair(
5097 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5098 }
5099 } else if (FieldDecl *FD = Member->getMember()) {
5100 if (FD->getParent()->isUnion())
5101 Info.ActiveUnionMember.insert(std::make_pair(
5102 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5103 }
5104 }
5105 }
5106
5107 // Keep track of the direct virtual bases.
5108 llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
5109 for (auto &I : ClassDecl->bases()) {
5110 if (I.isVirtual())
5111 DirectVBases.insert(&I);
5112 }
5113
5114 // Push virtual bases before others.
5115 for (auto &VBase : ClassDecl->vbases()) {
5116 if (CXXCtorInitializer *Value
5117 = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
5118 // [class.base.init]p7, per DR257:
5119 // A mem-initializer where the mem-initializer-id names a virtual base
5120 // class is ignored during execution of a constructor of any class that
5121 // is not the most derived class.
5122 if (ClassDecl->isAbstract()) {
5123 // FIXME: Provide a fixit to remove the base specifier. This requires
5124 // tracking the location of the associated comma for a base specifier.
5125 Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
5126 << VBase.getType() << ClassDecl;
5127 DiagnoseAbstractType(ClassDecl);
5128 }
5129
5130 Info.AllToInit.push_back(Value);
5131 } else if (!AnyErrors && !ClassDecl->isAbstract()) {
5132 // [class.base.init]p8, per DR257:
5133 // If a given [...] base class is not named by a mem-initializer-id
5134 // [...] and the entity is not a virtual base class of an abstract
5135 // class, then [...] the entity is default-initialized.
5136 bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
5137 CXXCtorInitializer *CXXBaseInit;
5138 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5139 &VBase, IsInheritedVirtualBase,
5140 CXXBaseInit)) {
5141 HadError = true;
5142 continue;
5143 }
5144
5145 Info.AllToInit.push_back(CXXBaseInit);
5146 }
5147 }
5148
5149 // Non-virtual bases.
5150 for (auto &Base : ClassDecl->bases()) {
5151 // Virtuals are in the virtual base list and already constructed.
5152 if (Base.isVirtual())
5153 continue;
5154
5155 if (CXXCtorInitializer *Value
5156 = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
5157 Info.AllToInit.push_back(Value);
5158 } else if (!AnyErrors) {
5159 CXXCtorInitializer *CXXBaseInit;
5160 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5161 &Base, /*IsInheritedVirtualBase=*/false,
5162 CXXBaseInit)) {
5163 HadError = true;
5164 continue;
5165 }
5166
5167 Info.AllToInit.push_back(CXXBaseInit);
5168 }
5169 }
5170
5171 // Fields.
5172 for (auto *Mem : ClassDecl->decls()) {
5173 if (auto *F = dyn_cast<FieldDecl>(Mem)) {
5174 // C++ [class.bit]p2:
5175 // A declaration for a bit-field that omits the identifier declares an
5176 // unnamed bit-field. Unnamed bit-fields are not members and cannot be
5177 // initialized.
5178 if (F->isUnnamedBitfield())
5179 continue;
5180
5181 // If we're not generating the implicit copy/move constructor, then we'll
5182 // handle anonymous struct/union fields based on their individual
5183 // indirect fields.
5184 if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
5185 continue;
5186
5187 if (CollectFieldInitializer(*this, Info, F))
5188 HadError = true;
5189 continue;
5190 }
5191
5192 // Beyond this point, we only consider default initialization.
5193 if (Info.isImplicitCopyOrMove())
5194 continue;
5195
5196 if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
5197 if (F->getType()->isIncompleteArrayType()) {
5198 assert(ClassDecl->hasFlexibleArrayMember() &&
5199 "Incomplete array type is not valid");
5200 continue;
5201 }
5202
5203 // Initialize each field of an anonymous struct individually.
5204 if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
5205 HadError = true;
5206
5207 continue;
5208 }
5209 }
5210
5211 unsigned NumInitializers = Info.AllToInit.size();
5212 if (NumInitializers > 0) {
5213 Constructor->setNumCtorInitializers(NumInitializers);
5214 CXXCtorInitializer **baseOrMemberInitializers =
5215 new (Context) CXXCtorInitializer*[NumInitializers];
5216 memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
5217 NumInitializers * sizeof(CXXCtorInitializer*));
5218 Constructor->setCtorInitializers(baseOrMemberInitializers);
5219
5220 // Constructors implicitly reference the base and member
5221 // destructors.
5222 MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
5223 Constructor->getParent());
5224 }
5225
5226 return HadError;
5227 }
5228
PopulateKeysForFields(FieldDecl * Field,SmallVectorImpl<const void * > & IdealInits)5229 static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
5230 if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
5231 const RecordDecl *RD = RT->getDecl();
5232 if (RD->isAnonymousStructOrUnion()) {
5233 for (auto *Field : RD->fields())
5234 PopulateKeysForFields(Field, IdealInits);
5235 return;
5236 }
5237 }
5238 IdealInits.push_back(Field->getCanonicalDecl());
5239 }
5240
GetKeyForBase(ASTContext & Context,QualType BaseType)5241 static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
5242 return Context.getCanonicalType(BaseType).getTypePtr();
5243 }
5244
GetKeyForMember(ASTContext & Context,CXXCtorInitializer * Member)5245 static const void *GetKeyForMember(ASTContext &Context,
5246 CXXCtorInitializer *Member) {
5247 if (!Member->isAnyMemberInitializer())
5248 return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
5249
5250 return Member->getAnyMember()->getCanonicalDecl();
5251 }
5252
AddInitializerToDiag(const Sema::SemaDiagnosticBuilder & Diag,const CXXCtorInitializer * Previous,const CXXCtorInitializer * Current)5253 static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag,
5254 const CXXCtorInitializer *Previous,
5255 const CXXCtorInitializer *Current) {
5256 if (Previous->isAnyMemberInitializer())
5257 Diag << 0 << Previous->getAnyMember();
5258 else
5259 Diag << 1 << Previous->getTypeSourceInfo()->getType();
5260
5261 if (Current->isAnyMemberInitializer())
5262 Diag << 0 << Current->getAnyMember();
5263 else
5264 Diag << 1 << Current->getTypeSourceInfo()->getType();
5265 }
5266
DiagnoseBaseOrMemInitializerOrder(Sema & SemaRef,const CXXConstructorDecl * Constructor,ArrayRef<CXXCtorInitializer * > Inits)5267 static void DiagnoseBaseOrMemInitializerOrder(
5268 Sema &SemaRef, const CXXConstructorDecl *Constructor,
5269 ArrayRef<CXXCtorInitializer *> Inits) {
5270 if (Constructor->getDeclContext()->isDependentContext())
5271 return;
5272
5273 // Don't check initializers order unless the warning is enabled at the
5274 // location of at least one initializer.
5275 bool ShouldCheckOrder = false;
5276 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5277 CXXCtorInitializer *Init = Inits[InitIndex];
5278 if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
5279 Init->getSourceLocation())) {
5280 ShouldCheckOrder = true;
5281 break;
5282 }
5283 }
5284 if (!ShouldCheckOrder)
5285 return;
5286
5287 // Build the list of bases and members in the order that they'll
5288 // actually be initialized. The explicit initializers should be in
5289 // this same order but may be missing things.
5290 SmallVector<const void*, 32> IdealInitKeys;
5291
5292 const CXXRecordDecl *ClassDecl = Constructor->getParent();
5293
5294 // 1. Virtual bases.
5295 for (const auto &VBase : ClassDecl->vbases())
5296 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
5297
5298 // 2. Non-virtual bases.
5299 for (const auto &Base : ClassDecl->bases()) {
5300 if (Base.isVirtual())
5301 continue;
5302 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
5303 }
5304
5305 // 3. Direct fields.
5306 for (auto *Field : ClassDecl->fields()) {
5307 if (Field->isUnnamedBitfield())
5308 continue;
5309
5310 PopulateKeysForFields(Field, IdealInitKeys);
5311 }
5312
5313 unsigned NumIdealInits = IdealInitKeys.size();
5314 unsigned IdealIndex = 0;
5315
5316 // Track initializers that are in an incorrect order for either a warning or
5317 // note if multiple ones occur.
5318 SmallVector<unsigned> WarnIndexes;
5319 // Correlates the index of an initializer in the init-list to the index of
5320 // the field/base in the class.
5321 SmallVector<std::pair<unsigned, unsigned>, 32> CorrelatedInitOrder;
5322
5323 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5324 const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]);
5325
5326 // Scan forward to try to find this initializer in the idealized
5327 // initializers list.
5328 for (; IdealIndex != NumIdealInits; ++IdealIndex)
5329 if (InitKey == IdealInitKeys[IdealIndex])
5330 break;
5331
5332 // If we didn't find this initializer, it must be because we
5333 // scanned past it on a previous iteration. That can only
5334 // happen if we're out of order; emit a warning.
5335 if (IdealIndex == NumIdealInits && InitIndex) {
5336 WarnIndexes.push_back(InitIndex);
5337
5338 // Move back to the initializer's location in the ideal list.
5339 for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
5340 if (InitKey == IdealInitKeys[IdealIndex])
5341 break;
5342
5343 assert(IdealIndex < NumIdealInits &&
5344 "initializer not found in initializer list");
5345 }
5346 CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex);
5347 }
5348
5349 if (WarnIndexes.empty())
5350 return;
5351
5352 // Sort based on the ideal order, first in the pair.
5353 llvm::sort(CorrelatedInitOrder,
5354 [](auto &LHS, auto &RHS) { return LHS.first < RHS.first; });
5355
5356 // Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to
5357 // emit the diagnostic before we can try adding notes.
5358 {
5359 Sema::SemaDiagnosticBuilder D = SemaRef.Diag(
5360 Inits[WarnIndexes.front() - 1]->getSourceLocation(),
5361 WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order
5362 : diag::warn_some_initializers_out_of_order);
5363
5364 for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) {
5365 if (CorrelatedInitOrder[I].second == I)
5366 continue;
5367 // Ideally we would be using InsertFromRange here, but clang doesn't
5368 // appear to handle InsertFromRange correctly when the source range is
5369 // modified by another fix-it.
5370 D << FixItHint::CreateReplacement(
5371 Inits[I]->getSourceRange(),
5372 Lexer::getSourceText(
5373 CharSourceRange::getTokenRange(
5374 Inits[CorrelatedInitOrder[I].second]->getSourceRange()),
5375 SemaRef.getSourceManager(), SemaRef.getLangOpts()));
5376 }
5377
5378 // If there is only 1 item out of order, the warning expects the name and
5379 // type of each being added to it.
5380 if (WarnIndexes.size() == 1) {
5381 AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1],
5382 Inits[WarnIndexes.front()]);
5383 return;
5384 }
5385 }
5386 // More than 1 item to warn, create notes letting the user know which ones
5387 // are bad.
5388 for (unsigned WarnIndex : WarnIndexes) {
5389 const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1];
5390 auto D = SemaRef.Diag(PrevInit->getSourceLocation(),
5391 diag::note_initializer_out_of_order);
5392 AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]);
5393 D << PrevInit->getSourceRange();
5394 }
5395 }
5396
5397 namespace {
CheckRedundantInit(Sema & S,CXXCtorInitializer * Init,CXXCtorInitializer * & PrevInit)5398 bool CheckRedundantInit(Sema &S,
5399 CXXCtorInitializer *Init,
5400 CXXCtorInitializer *&PrevInit) {
5401 if (!PrevInit) {
5402 PrevInit = Init;
5403 return false;
5404 }
5405
5406 if (FieldDecl *Field = Init->getAnyMember())
5407 S.Diag(Init->getSourceLocation(),
5408 diag::err_multiple_mem_initialization)
5409 << Field->getDeclName()
5410 << Init->getSourceRange();
5411 else {
5412 const Type *BaseClass = Init->getBaseClass();
5413 assert(BaseClass && "neither field nor base");
5414 S.Diag(Init->getSourceLocation(),
5415 diag::err_multiple_base_initialization)
5416 << QualType(BaseClass, 0)
5417 << Init->getSourceRange();
5418 }
5419 S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5420 << 0 << PrevInit->getSourceRange();
5421
5422 return true;
5423 }
5424
5425 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5426 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5427
CheckRedundantUnionInit(Sema & S,CXXCtorInitializer * Init,RedundantUnionMap & Unions)5428 bool CheckRedundantUnionInit(Sema &S,
5429 CXXCtorInitializer *Init,
5430 RedundantUnionMap &Unions) {
5431 FieldDecl *Field = Init->getAnyMember();
5432 RecordDecl *Parent = Field->getParent();
5433 NamedDecl *Child = Field;
5434
5435 while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5436 if (Parent->isUnion()) {
5437 UnionEntry &En = Unions[Parent];
5438 if (En.first && En.first != Child) {
5439 S.Diag(Init->getSourceLocation(),
5440 diag::err_multiple_mem_union_initialization)
5441 << Field->getDeclName()
5442 << Init->getSourceRange();
5443 S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5444 << 0 << En.second->getSourceRange();
5445 return true;
5446 }
5447 if (!En.first) {
5448 En.first = Child;
5449 En.second = Init;
5450 }
5451 if (!Parent->isAnonymousStructOrUnion())
5452 return false;
5453 }
5454
5455 Child = Parent;
5456 Parent = cast<RecordDecl>(Parent->getDeclContext());
5457 }
5458
5459 return false;
5460 }
5461 } // namespace
5462
5463 /// ActOnMemInitializers - Handle the member initializers for a constructor.
ActOnMemInitializers(Decl * ConstructorDecl,SourceLocation ColonLoc,ArrayRef<CXXCtorInitializer * > MemInits,bool AnyErrors)5464 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5465 SourceLocation ColonLoc,
5466 ArrayRef<CXXCtorInitializer*> MemInits,
5467 bool AnyErrors) {
5468 if (!ConstructorDecl)
5469 return;
5470
5471 AdjustDeclIfTemplate(ConstructorDecl);
5472
5473 CXXConstructorDecl *Constructor
5474 = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5475
5476 if (!Constructor) {
5477 Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5478 return;
5479 }
5480
5481 // Mapping for the duplicate initializers check.
5482 // For member initializers, this is keyed with a FieldDecl*.
5483 // For base initializers, this is keyed with a Type*.
5484 llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5485
5486 // Mapping for the inconsistent anonymous-union initializers check.
5487 RedundantUnionMap MemberUnions;
5488
5489 bool HadError = false;
5490 for (unsigned i = 0; i < MemInits.size(); i++) {
5491 CXXCtorInitializer *Init = MemInits[i];
5492
5493 // Set the source order index.
5494 Init->setSourceOrder(i);
5495
5496 if (Init->isAnyMemberInitializer()) {
5497 const void *Key = GetKeyForMember(Context, Init);
5498 if (CheckRedundantInit(*this, Init, Members[Key]) ||
5499 CheckRedundantUnionInit(*this, Init, MemberUnions))
5500 HadError = true;
5501 } else if (Init->isBaseInitializer()) {
5502 const void *Key = GetKeyForMember(Context, Init);
5503 if (CheckRedundantInit(*this, Init, Members[Key]))
5504 HadError = true;
5505 } else {
5506 assert(Init->isDelegatingInitializer());
5507 // This must be the only initializer
5508 if (MemInits.size() != 1) {
5509 Diag(Init->getSourceLocation(),
5510 diag::err_delegating_initializer_alone)
5511 << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5512 // We will treat this as being the only initializer.
5513 }
5514 SetDelegatingInitializer(Constructor, MemInits[i]);
5515 // Return immediately as the initializer is set.
5516 return;
5517 }
5518 }
5519
5520 if (HadError)
5521 return;
5522
5523 DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5524
5525 SetCtorInitializers(Constructor, AnyErrors, MemInits);
5526
5527 DiagnoseUninitializedFields(*this, Constructor);
5528 }
5529
5530 void
MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,CXXRecordDecl * ClassDecl)5531 Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
5532 CXXRecordDecl *ClassDecl) {
5533 // Ignore dependent contexts. Also ignore unions, since their members never
5534 // have destructors implicitly called.
5535 if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5536 return;
5537
5538 // FIXME: all the access-control diagnostics are positioned on the
5539 // field/base declaration. That's probably good; that said, the
5540 // user might reasonably want to know why the destructor is being
5541 // emitted, and we currently don't say.
5542
5543 // Non-static data members.
5544 for (auto *Field : ClassDecl->fields()) {
5545 if (Field->isInvalidDecl())
5546 continue;
5547
5548 // Don't destroy incomplete or zero-length arrays.
5549 if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5550 continue;
5551
5552 QualType FieldType = Context.getBaseElementType(Field->getType());
5553
5554 const RecordType* RT = FieldType->getAs<RecordType>();
5555 if (!RT)
5556 continue;
5557
5558 CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5559 if (FieldClassDecl->isInvalidDecl())
5560 continue;
5561 if (FieldClassDecl->hasIrrelevantDestructor())
5562 continue;
5563 // The destructor for an implicit anonymous union member is never invoked.
5564 if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5565 continue;
5566
5567 CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5568 assert(Dtor && "No dtor found for FieldClassDecl!");
5569 CheckDestructorAccess(Field->getLocation(), Dtor,
5570 PDiag(diag::err_access_dtor_field)
5571 << Field->getDeclName()
5572 << FieldType);
5573
5574 MarkFunctionReferenced(Location, Dtor);
5575 DiagnoseUseOfDecl(Dtor, Location);
5576 }
5577
5578 // We only potentially invoke the destructors of potentially constructed
5579 // subobjects.
5580 bool VisitVirtualBases = !ClassDecl->isAbstract();
5581
5582 // If the destructor exists and has already been marked used in the MS ABI,
5583 // then virtual base destructors have already been checked and marked used.
5584 // Skip checking them again to avoid duplicate diagnostics.
5585 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5586 CXXDestructorDecl *Dtor = ClassDecl->getDestructor();
5587 if (Dtor && Dtor->isUsed())
5588 VisitVirtualBases = false;
5589 }
5590
5591 llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5592
5593 // Bases.
5594 for (const auto &Base : ClassDecl->bases()) {
5595 const RecordType *RT = Base.getType()->getAs<RecordType>();
5596 if (!RT)
5597 continue;
5598
5599 // Remember direct virtual bases.
5600 if (Base.isVirtual()) {
5601 if (!VisitVirtualBases)
5602 continue;
5603 DirectVirtualBases.insert(RT);
5604 }
5605
5606 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5607 // If our base class is invalid, we probably can't get its dtor anyway.
5608 if (BaseClassDecl->isInvalidDecl())
5609 continue;
5610 if (BaseClassDecl->hasIrrelevantDestructor())
5611 continue;
5612
5613 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5614 assert(Dtor && "No dtor found for BaseClassDecl!");
5615
5616 // FIXME: caret should be on the start of the class name
5617 CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5618 PDiag(diag::err_access_dtor_base)
5619 << Base.getType() << Base.getSourceRange(),
5620 Context.getTypeDeclType(ClassDecl));
5621
5622 MarkFunctionReferenced(Location, Dtor);
5623 DiagnoseUseOfDecl(Dtor, Location);
5624 }
5625
5626 if (VisitVirtualBases)
5627 MarkVirtualBaseDestructorsReferenced(Location, ClassDecl,
5628 &DirectVirtualBases);
5629 }
5630
MarkVirtualBaseDestructorsReferenced(SourceLocation Location,CXXRecordDecl * ClassDecl,llvm::SmallPtrSetImpl<const RecordType * > * DirectVirtualBases)5631 void Sema::MarkVirtualBaseDestructorsReferenced(
5632 SourceLocation Location, CXXRecordDecl *ClassDecl,
5633 llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases) {
5634 // Virtual bases.
5635 for (const auto &VBase : ClassDecl->vbases()) {
5636 // Bases are always records in a well-formed non-dependent class.
5637 const RecordType *RT = VBase.getType()->castAs<RecordType>();
5638
5639 // Ignore already visited direct virtual bases.
5640 if (DirectVirtualBases && DirectVirtualBases->count(RT))
5641 continue;
5642
5643 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5644 // If our base class is invalid, we probably can't get its dtor anyway.
5645 if (BaseClassDecl->isInvalidDecl())
5646 continue;
5647 if (BaseClassDecl->hasIrrelevantDestructor())
5648 continue;
5649
5650 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5651 assert(Dtor && "No dtor found for BaseClassDecl!");
5652 if (CheckDestructorAccess(
5653 ClassDecl->getLocation(), Dtor,
5654 PDiag(diag::err_access_dtor_vbase)
5655 << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5656 Context.getTypeDeclType(ClassDecl)) ==
5657 AR_accessible) {
5658 CheckDerivedToBaseConversion(
5659 Context.getTypeDeclType(ClassDecl), VBase.getType(),
5660 diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5661 SourceRange(), DeclarationName(), nullptr);
5662 }
5663
5664 MarkFunctionReferenced(Location, Dtor);
5665 DiagnoseUseOfDecl(Dtor, Location);
5666 }
5667 }
5668
ActOnDefaultCtorInitializers(Decl * CDtorDecl)5669 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5670 if (!CDtorDecl)
5671 return;
5672
5673 if (CXXConstructorDecl *Constructor
5674 = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5675 SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5676 DiagnoseUninitializedFields(*this, Constructor);
5677 }
5678 }
5679
isAbstractType(SourceLocation Loc,QualType T)5680 bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
5681 if (!getLangOpts().CPlusPlus)
5682 return false;
5683
5684 const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5685 if (!RD)
5686 return false;
5687
5688 // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5689 // class template specialization here, but doing so breaks a lot of code.
5690
5691 // We can't answer whether something is abstract until it has a
5692 // definition. If it's currently being defined, we'll walk back
5693 // over all the declarations when we have a full definition.
5694 const CXXRecordDecl *Def = RD->getDefinition();
5695 if (!Def || Def->isBeingDefined())
5696 return false;
5697
5698 return RD->isAbstract();
5699 }
5700
RequireNonAbstractType(SourceLocation Loc,QualType T,TypeDiagnoser & Diagnoser)5701 bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
5702 TypeDiagnoser &Diagnoser) {
5703 if (!isAbstractType(Loc, T))
5704 return false;
5705
5706 T = Context.getBaseElementType(T);
5707 Diagnoser.diagnose(*this, Loc, T);
5708 DiagnoseAbstractType(T->getAsCXXRecordDecl());
5709 return true;
5710 }
5711
DiagnoseAbstractType(const CXXRecordDecl * RD)5712 void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
5713 // Check if we've already emitted the list of pure virtual functions
5714 // for this class.
5715 if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5716 return;
5717
5718 // If the diagnostic is suppressed, don't emit the notes. We're only
5719 // going to emit them once, so try to attach them to a diagnostic we're
5720 // actually going to show.
5721 if (Diags.isLastDiagnosticIgnored())
5722 return;
5723
5724 CXXFinalOverriderMap FinalOverriders;
5725 RD->getFinalOverriders(FinalOverriders);
5726
5727 // Keep a set of seen pure methods so we won't diagnose the same method
5728 // more than once.
5729 llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5730
5731 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5732 MEnd = FinalOverriders.end();
5733 M != MEnd;
5734 ++M) {
5735 for (OverridingMethods::iterator SO = M->second.begin(),
5736 SOEnd = M->second.end();
5737 SO != SOEnd; ++SO) {
5738 // C++ [class.abstract]p4:
5739 // A class is abstract if it contains or inherits at least one
5740 // pure virtual function for which the final overrider is pure
5741 // virtual.
5742
5743 //
5744 if (SO->second.size() != 1)
5745 continue;
5746
5747 if (!SO->second.front().Method->isPure())
5748 continue;
5749
5750 if (!SeenPureMethods.insert(SO->second.front().Method).second)
5751 continue;
5752
5753 Diag(SO->second.front().Method->getLocation(),
5754 diag::note_pure_virtual_function)
5755 << SO->second.front().Method->getDeclName() << RD->getDeclName();
5756 }
5757 }
5758
5759 if (!PureVirtualClassDiagSet)
5760 PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5761 PureVirtualClassDiagSet->insert(RD);
5762 }
5763
5764 namespace {
5765 struct AbstractUsageInfo {
5766 Sema &S;
5767 CXXRecordDecl *Record;
5768 CanQualType AbstractType;
5769 bool Invalid;
5770
AbstractUsageInfo__anonb2a824811511::AbstractUsageInfo5771 AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5772 : S(S), Record(Record),
5773 AbstractType(S.Context.getCanonicalType(
5774 S.Context.getTypeDeclType(Record))),
5775 Invalid(false) {}
5776
DiagnoseAbstractType__anonb2a824811511::AbstractUsageInfo5777 void DiagnoseAbstractType() {
5778 if (Invalid) return;
5779 S.DiagnoseAbstractType(Record);
5780 Invalid = true;
5781 }
5782
5783 void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5784 };
5785
5786 struct CheckAbstractUsage {
5787 AbstractUsageInfo &Info;
5788 const NamedDecl *Ctx;
5789
CheckAbstractUsage__anonb2a824811511::CheckAbstractUsage5790 CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5791 : Info(Info), Ctx(Ctx) {}
5792
Visit__anonb2a824811511::CheckAbstractUsage5793 void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5794 switch (TL.getTypeLocClass()) {
5795 #define ABSTRACT_TYPELOC(CLASS, PARENT)
5796 #define TYPELOC(CLASS, PARENT) \
5797 case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5798 #include "clang/AST/TypeLocNodes.def"
5799 }
5800 }
5801
Check__anonb2a824811511::CheckAbstractUsage5802 void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5803 Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
5804 for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5805 if (!TL.getParam(I))
5806 continue;
5807
5808 TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5809 if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5810 }
5811 }
5812
Check__anonb2a824811511::CheckAbstractUsage5813 void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5814 Visit(TL.getElementLoc(), Sema::AbstractArrayType);
5815 }
5816
Check__anonb2a824811511::CheckAbstractUsage5817 void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5818 // Visit the type parameters from a permissive context.
5819 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5820 TemplateArgumentLoc TAL = TL.getArgLoc(I);
5821 if (TAL.getArgument().getKind() == TemplateArgument::Type)
5822 if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5823 Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5824 // TODO: other template argument types?
5825 }
5826 }
5827
5828 // Visit pointee types from a permissive context.
5829 #define CheckPolymorphic(Type) \
5830 void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5831 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5832 }
5833 CheckPolymorphic(PointerTypeLoc)
CheckPolymorphic__anonb2a824811511::CheckAbstractUsage5834 CheckPolymorphic(ReferenceTypeLoc)
5835 CheckPolymorphic(MemberPointerTypeLoc)
5836 CheckPolymorphic(BlockPointerTypeLoc)
5837 CheckPolymorphic(AtomicTypeLoc)
5838
5839 /// Handle all the types we haven't given a more specific
5840 /// implementation for above.
5841 void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5842 // Every other kind of type that we haven't called out already
5843 // that has an inner type is either (1) sugar or (2) contains that
5844 // inner type in some way as a subobject.
5845 if (TypeLoc Next = TL.getNextTypeLoc())
5846 return Visit(Next, Sel);
5847
5848 // If there's no inner type and we're in a permissive context,
5849 // don't diagnose.
5850 if (Sel == Sema::AbstractNone) return;
5851
5852 // Check whether the type matches the abstract type.
5853 QualType T = TL.getType();
5854 if (T->isArrayType()) {
5855 Sel = Sema::AbstractArrayType;
5856 T = Info.S.Context.getBaseElementType(T);
5857 }
5858 CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
5859 if (CT != Info.AbstractType) return;
5860
5861 // It matched; do some magic.
5862 if (Sel == Sema::AbstractArrayType) {
5863 Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5864 << T << TL.getSourceRange();
5865 } else {
5866 Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5867 << Sel << T << TL.getSourceRange();
5868 }
5869 Info.DiagnoseAbstractType();
5870 }
5871 };
5872
CheckType(const NamedDecl * D,TypeLoc TL,Sema::AbstractDiagSelID Sel)5873 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5874 Sema::AbstractDiagSelID Sel) {
5875 CheckAbstractUsage(*this, D).Visit(TL, Sel);
5876 }
5877
5878 }
5879
5880 /// Check for invalid uses of an abstract type in a method declaration.
CheckAbstractClassUsage(AbstractUsageInfo & Info,CXXMethodDecl * MD)5881 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5882 CXXMethodDecl *MD) {
5883 // No need to do the check on definitions, which require that
5884 // the return/param types be complete.
5885 if (MD->doesThisDeclarationHaveABody())
5886 return;
5887
5888 // For safety's sake, just ignore it if we don't have type source
5889 // information. This should never happen for non-implicit methods,
5890 // but...
5891 if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5892 Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5893 }
5894
5895 /// Check for invalid uses of an abstract type within a class definition.
CheckAbstractClassUsage(AbstractUsageInfo & Info,CXXRecordDecl * RD)5896 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5897 CXXRecordDecl *RD) {
5898 for (auto *D : RD->decls()) {
5899 if (D->isImplicit()) continue;
5900
5901 // Methods and method templates.
5902 if (isa<CXXMethodDecl>(D)) {
5903 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5904 } else if (isa<FunctionTemplateDecl>(D)) {
5905 FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5906 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5907
5908 // Fields and static variables.
5909 } else if (isa<FieldDecl>(D)) {
5910 FieldDecl *FD = cast<FieldDecl>(D);
5911 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5912 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5913 } else if (isa<VarDecl>(D)) {
5914 VarDecl *VD = cast<VarDecl>(D);
5915 if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5916 Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5917
5918 // Nested classes and class templates.
5919 } else if (isa<CXXRecordDecl>(D)) {
5920 CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5921 } else if (isa<ClassTemplateDecl>(D)) {
5922 CheckAbstractClassUsage(Info,
5923 cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5924 }
5925 }
5926 }
5927
ReferenceDllExportedMembers(Sema & S,CXXRecordDecl * Class)5928 static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) {
5929 Attr *ClassAttr = getDLLAttr(Class);
5930 if (!ClassAttr)
5931 return;
5932
5933 assert(ClassAttr->getKind() == attr::DLLExport);
5934
5935 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
5936
5937 if (TSK == TSK_ExplicitInstantiationDeclaration)
5938 // Don't go any further if this is just an explicit instantiation
5939 // declaration.
5940 return;
5941
5942 // Add a context note to explain how we got to any diagnostics produced below.
5943 struct MarkingClassDllexported {
5944 Sema &S;
5945 MarkingClassDllexported(Sema &S, CXXRecordDecl *Class,
5946 SourceLocation AttrLoc)
5947 : S(S) {
5948 Sema::CodeSynthesisContext Ctx;
5949 Ctx.Kind = Sema::CodeSynthesisContext::MarkingClassDllexported;
5950 Ctx.PointOfInstantiation = AttrLoc;
5951 Ctx.Entity = Class;
5952 S.pushCodeSynthesisContext(Ctx);
5953 }
5954 ~MarkingClassDllexported() {
5955 S.popCodeSynthesisContext();
5956 }
5957 } MarkingDllexportedContext(S, Class, ClassAttr->getLocation());
5958
5959 if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
5960 S.MarkVTableUsed(Class->getLocation(), Class, true);
5961
5962 for (Decl *Member : Class->decls()) {
5963 // Defined static variables that are members of an exported base
5964 // class must be marked export too.
5965 auto *VD = dyn_cast<VarDecl>(Member);
5966 if (VD && Member->getAttr<DLLExportAttr>() &&
5967 VD->getStorageClass() == SC_Static &&
5968 TSK == TSK_ImplicitInstantiation)
5969 S.MarkVariableReferenced(VD->getLocation(), VD);
5970
5971 auto *MD = dyn_cast<CXXMethodDecl>(Member);
5972 if (!MD)
5973 continue;
5974
5975 if (Member->getAttr<DLLExportAttr>()) {
5976 if (MD->isUserProvided()) {
5977 // Instantiate non-default class member functions ...
5978
5979 // .. except for certain kinds of template specializations.
5980 if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5981 continue;
5982
5983 S.MarkFunctionReferenced(Class->getLocation(), MD);
5984
5985 // The function will be passed to the consumer when its definition is
5986 // encountered.
5987 } else if (MD->isExplicitlyDefaulted()) {
5988 // Synthesize and instantiate explicitly defaulted methods.
5989 S.MarkFunctionReferenced(Class->getLocation(), MD);
5990
5991 if (TSK != TSK_ExplicitInstantiationDefinition) {
5992 // Except for explicit instantiation defs, we will not see the
5993 // definition again later, so pass it to the consumer now.
5994 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
5995 }
5996 } else if (!MD->isTrivial() ||
5997 MD->isCopyAssignmentOperator() ||
5998 MD->isMoveAssignmentOperator()) {
5999 // Synthesize and instantiate non-trivial implicit methods, and the copy
6000 // and move assignment operators. The latter are exported even if they
6001 // are trivial, because the address of an operator can be taken and
6002 // should compare equal across libraries.
6003 S.MarkFunctionReferenced(Class->getLocation(), MD);
6004
6005 // There is no later point when we will see the definition of this
6006 // function, so pass it to the consumer now.
6007 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
6008 }
6009 }
6010 }
6011 }
6012
checkForMultipleExportedDefaultConstructors(Sema & S,CXXRecordDecl * Class)6013 static void checkForMultipleExportedDefaultConstructors(Sema &S,
6014 CXXRecordDecl *Class) {
6015 // Only the MS ABI has default constructor closures, so we don't need to do
6016 // this semantic checking anywhere else.
6017 if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft())
6018 return;
6019
6020 CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
6021 for (Decl *Member : Class->decls()) {
6022 // Look for exported default constructors.
6023 auto *CD = dyn_cast<CXXConstructorDecl>(Member);
6024 if (!CD || !CD->isDefaultConstructor())
6025 continue;
6026 auto *Attr = CD->getAttr<DLLExportAttr>();
6027 if (!Attr)
6028 continue;
6029
6030 // If the class is non-dependent, mark the default arguments as ODR-used so
6031 // that we can properly codegen the constructor closure.
6032 if (!Class->isDependentContext()) {
6033 for (ParmVarDecl *PD : CD->parameters()) {
6034 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
6035 S.DiscardCleanupsInEvaluationContext();
6036 }
6037 }
6038
6039 if (LastExportedDefaultCtor) {
6040 S.Diag(LastExportedDefaultCtor->getLocation(),
6041 diag::err_attribute_dll_ambiguous_default_ctor)
6042 << Class;
6043 S.Diag(CD->getLocation(), diag::note_entity_declared_at)
6044 << CD->getDeclName();
6045 return;
6046 }
6047 LastExportedDefaultCtor = CD;
6048 }
6049 }
6050
checkCUDADeviceBuiltinSurfaceClassTemplate(Sema & S,CXXRecordDecl * Class)6051 static void checkCUDADeviceBuiltinSurfaceClassTemplate(Sema &S,
6052 CXXRecordDecl *Class) {
6053 bool ErrorReported = false;
6054 auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
6055 ClassTemplateDecl *TD) {
6056 if (ErrorReported)
6057 return;
6058 S.Diag(TD->getLocation(),
6059 diag::err_cuda_device_builtin_surftex_cls_template)
6060 << /*surface*/ 0 << TD;
6061 ErrorReported = true;
6062 };
6063
6064 ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
6065 if (!TD) {
6066 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
6067 if (!SD) {
6068 S.Diag(Class->getLocation(),
6069 diag::err_cuda_device_builtin_surftex_ref_decl)
6070 << /*surface*/ 0 << Class;
6071 S.Diag(Class->getLocation(),
6072 diag::note_cuda_device_builtin_surftex_should_be_template_class)
6073 << Class;
6074 return;
6075 }
6076 TD = SD->getSpecializedTemplate();
6077 }
6078
6079 TemplateParameterList *Params = TD->getTemplateParameters();
6080 unsigned N = Params->size();
6081
6082 if (N != 2) {
6083 reportIllegalClassTemplate(S, TD);
6084 S.Diag(TD->getLocation(),
6085 diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
6086 << TD << 2;
6087 }
6088 if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
6089 reportIllegalClassTemplate(S, TD);
6090 S.Diag(TD->getLocation(),
6091 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6092 << TD << /*1st*/ 0 << /*type*/ 0;
6093 }
6094 if (N > 1) {
6095 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
6096 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
6097 reportIllegalClassTemplate(S, TD);
6098 S.Diag(TD->getLocation(),
6099 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6100 << TD << /*2nd*/ 1 << /*integer*/ 1;
6101 }
6102 }
6103 }
6104
checkCUDADeviceBuiltinTextureClassTemplate(Sema & S,CXXRecordDecl * Class)6105 static void checkCUDADeviceBuiltinTextureClassTemplate(Sema &S,
6106 CXXRecordDecl *Class) {
6107 bool ErrorReported = false;
6108 auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
6109 ClassTemplateDecl *TD) {
6110 if (ErrorReported)
6111 return;
6112 S.Diag(TD->getLocation(),
6113 diag::err_cuda_device_builtin_surftex_cls_template)
6114 << /*texture*/ 1 << TD;
6115 ErrorReported = true;
6116 };
6117
6118 ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
6119 if (!TD) {
6120 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
6121 if (!SD) {
6122 S.Diag(Class->getLocation(),
6123 diag::err_cuda_device_builtin_surftex_ref_decl)
6124 << /*texture*/ 1 << Class;
6125 S.Diag(Class->getLocation(),
6126 diag::note_cuda_device_builtin_surftex_should_be_template_class)
6127 << Class;
6128 return;
6129 }
6130 TD = SD->getSpecializedTemplate();
6131 }
6132
6133 TemplateParameterList *Params = TD->getTemplateParameters();
6134 unsigned N = Params->size();
6135
6136 if (N != 3) {
6137 reportIllegalClassTemplate(S, TD);
6138 S.Diag(TD->getLocation(),
6139 diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
6140 << TD << 3;
6141 }
6142 if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
6143 reportIllegalClassTemplate(S, TD);
6144 S.Diag(TD->getLocation(),
6145 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6146 << TD << /*1st*/ 0 << /*type*/ 0;
6147 }
6148 if (N > 1) {
6149 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
6150 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
6151 reportIllegalClassTemplate(S, TD);
6152 S.Diag(TD->getLocation(),
6153 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6154 << TD << /*2nd*/ 1 << /*integer*/ 1;
6155 }
6156 }
6157 if (N > 2) {
6158 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(2));
6159 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
6160 reportIllegalClassTemplate(S, TD);
6161 S.Diag(TD->getLocation(),
6162 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6163 << TD << /*3rd*/ 2 << /*integer*/ 1;
6164 }
6165 }
6166 }
6167
checkClassLevelCodeSegAttribute(CXXRecordDecl * Class)6168 void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) {
6169 // Mark any compiler-generated routines with the implicit code_seg attribute.
6170 for (auto *Method : Class->methods()) {
6171 if (Method->isUserProvided())
6172 continue;
6173 if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
6174 Method->addAttr(A);
6175 }
6176 }
6177
6178 /// Check class-level dllimport/dllexport attribute.
checkClassLevelDLLAttribute(CXXRecordDecl * Class)6179 void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) {
6180 Attr *ClassAttr = getDLLAttr(Class);
6181
6182 // MSVC inherits DLL attributes to partial class template specializations.
6183 if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && !ClassAttr) {
6184 if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
6185 if (Attr *TemplateAttr =
6186 getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
6187 auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
6188 A->setInherited(true);
6189 ClassAttr = A;
6190 }
6191 }
6192 }
6193
6194 if (!ClassAttr)
6195 return;
6196
6197 if (!Class->isExternallyVisible()) {
6198 Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
6199 << Class << ClassAttr;
6200 return;
6201 }
6202
6203 if (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
6204 !ClassAttr->isInherited()) {
6205 // Diagnose dll attributes on members of class with dll attribute.
6206 for (Decl *Member : Class->decls()) {
6207 if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
6208 continue;
6209 InheritableAttr *MemberAttr = getDLLAttr(Member);
6210 if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
6211 continue;
6212
6213 Diag(MemberAttr->getLocation(),
6214 diag::err_attribute_dll_member_of_dll_class)
6215 << MemberAttr << ClassAttr;
6216 Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
6217 Member->setInvalidDecl();
6218 }
6219 }
6220
6221 if (Class->getDescribedClassTemplate())
6222 // Don't inherit dll attribute until the template is instantiated.
6223 return;
6224
6225 // The class is either imported or exported.
6226 const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
6227
6228 // Check if this was a dllimport attribute propagated from a derived class to
6229 // a base class template specialization. We don't apply these attributes to
6230 // static data members.
6231 const bool PropagatedImport =
6232 !ClassExported &&
6233 cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
6234
6235 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
6236
6237 // Ignore explicit dllexport on explicit class template instantiation
6238 // declarations, except in MinGW mode.
6239 if (ClassExported && !ClassAttr->isInherited() &&
6240 TSK == TSK_ExplicitInstantiationDeclaration &&
6241 !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
6242 Class->dropAttr<DLLExportAttr>();
6243 return;
6244 }
6245
6246 // Force declaration of implicit members so they can inherit the attribute.
6247 ForceDeclarationOfImplicitMembers(Class);
6248
6249 // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
6250 // seem to be true in practice?
6251
6252 for (Decl *Member : Class->decls()) {
6253 VarDecl *VD = dyn_cast<VarDecl>(Member);
6254 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
6255
6256 // Only methods and static fields inherit the attributes.
6257 if (!VD && !MD)
6258 continue;
6259
6260 if (MD) {
6261 // Don't process deleted methods.
6262 if (MD->isDeleted())
6263 continue;
6264
6265 if (MD->isInlined()) {
6266 // MinGW does not import or export inline methods. But do it for
6267 // template instantiations.
6268 if (!Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
6269 TSK != TSK_ExplicitInstantiationDeclaration &&
6270 TSK != TSK_ExplicitInstantiationDefinition)
6271 continue;
6272
6273 // MSVC versions before 2015 don't export the move assignment operators
6274 // and move constructor, so don't attempt to import/export them if
6275 // we have a definition.
6276 auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
6277 if ((MD->isMoveAssignmentOperator() ||
6278 (Ctor && Ctor->isMoveConstructor())) &&
6279 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
6280 continue;
6281
6282 // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
6283 // operator is exported anyway.
6284 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
6285 (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
6286 continue;
6287 }
6288 }
6289
6290 // Don't apply dllimport attributes to static data members of class template
6291 // instantiations when the attribute is propagated from a derived class.
6292 if (VD && PropagatedImport)
6293 continue;
6294
6295 if (!cast<NamedDecl>(Member)->isExternallyVisible())
6296 continue;
6297
6298 if (!getDLLAttr(Member)) {
6299 InheritableAttr *NewAttr = nullptr;
6300
6301 // Do not export/import inline function when -fno-dllexport-inlines is
6302 // passed. But add attribute for later local static var check.
6303 if (!getLangOpts().DllExportInlines && MD && MD->isInlined() &&
6304 TSK != TSK_ExplicitInstantiationDeclaration &&
6305 TSK != TSK_ExplicitInstantiationDefinition) {
6306 if (ClassExported) {
6307 NewAttr = ::new (getASTContext())
6308 DLLExportStaticLocalAttr(getASTContext(), *ClassAttr);
6309 } else {
6310 NewAttr = ::new (getASTContext())
6311 DLLImportStaticLocalAttr(getASTContext(), *ClassAttr);
6312 }
6313 } else {
6314 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6315 }
6316
6317 NewAttr->setInherited(true);
6318 Member->addAttr(NewAttr);
6319
6320 if (MD) {
6321 // Propagate DLLAttr to friend re-declarations of MD that have already
6322 // been constructed.
6323 for (FunctionDecl *FD = MD->getMostRecentDecl(); FD;
6324 FD = FD->getPreviousDecl()) {
6325 if (FD->getFriendObjectKind() == Decl::FOK_None)
6326 continue;
6327 assert(!getDLLAttr(FD) &&
6328 "friend re-decl should not already have a DLLAttr");
6329 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6330 NewAttr->setInherited(true);
6331 FD->addAttr(NewAttr);
6332 }
6333 }
6334 }
6335 }
6336
6337 if (ClassExported)
6338 DelayedDllExportClasses.push_back(Class);
6339 }
6340
6341 /// Perform propagation of DLL attributes from a derived class to a
6342 /// templated base class for MS compatibility.
propagateDLLAttrToBaseClassTemplate(CXXRecordDecl * Class,Attr * ClassAttr,ClassTemplateSpecializationDecl * BaseTemplateSpec,SourceLocation BaseLoc)6343 void Sema::propagateDLLAttrToBaseClassTemplate(
6344 CXXRecordDecl *Class, Attr *ClassAttr,
6345 ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) {
6346 if (getDLLAttr(
6347 BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) {
6348 // If the base class template has a DLL attribute, don't try to change it.
6349 return;
6350 }
6351
6352 auto TSK = BaseTemplateSpec->getSpecializationKind();
6353 if (!getDLLAttr(BaseTemplateSpec) &&
6354 (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration ||
6355 TSK == TSK_ImplicitInstantiation)) {
6356 // The template hasn't been instantiated yet (or it has, but only as an
6357 // explicit instantiation declaration or implicit instantiation, which means
6358 // we haven't codegenned any members yet), so propagate the attribute.
6359 auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6360 NewAttr->setInherited(true);
6361 BaseTemplateSpec->addAttr(NewAttr);
6362
6363 // If this was an import, mark that we propagated it from a derived class to
6364 // a base class template specialization.
6365 if (auto *ImportAttr = dyn_cast<DLLImportAttr>(NewAttr))
6366 ImportAttr->setPropagatedToBaseTemplate();
6367
6368 // If the template is already instantiated, checkDLLAttributeRedeclaration()
6369 // needs to be run again to work see the new attribute. Otherwise this will
6370 // get run whenever the template is instantiated.
6371 if (TSK != TSK_Undeclared)
6372 checkClassLevelDLLAttribute(BaseTemplateSpec);
6373
6374 return;
6375 }
6376
6377 if (getDLLAttr(BaseTemplateSpec)) {
6378 // The template has already been specialized or instantiated with an
6379 // attribute, explicitly or through propagation. We should not try to change
6380 // it.
6381 return;
6382 }
6383
6384 // The template was previously instantiated or explicitly specialized without
6385 // a dll attribute, It's too late for us to add an attribute, so warn that
6386 // this is unsupported.
6387 Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class)
6388 << BaseTemplateSpec->isExplicitSpecialization();
6389 Diag(ClassAttr->getLocation(), diag::note_attribute);
6390 if (BaseTemplateSpec->isExplicitSpecialization()) {
6391 Diag(BaseTemplateSpec->getLocation(),
6392 diag::note_template_class_explicit_specialization_was_here)
6393 << BaseTemplateSpec;
6394 } else {
6395 Diag(BaseTemplateSpec->getPointOfInstantiation(),
6396 diag::note_template_class_instantiation_was_here)
6397 << BaseTemplateSpec;
6398 }
6399 }
6400
6401 /// Determine the kind of defaulting that would be done for a given function.
6402 ///
6403 /// If the function is both a default constructor and a copy / move constructor
6404 /// (due to having a default argument for the first parameter), this picks
6405 /// CXXDefaultConstructor.
6406 ///
6407 /// FIXME: Check that case is properly handled by all callers.
6408 Sema::DefaultedFunctionKind
getDefaultedFunctionKind(const FunctionDecl * FD)6409 Sema::getDefaultedFunctionKind(const FunctionDecl *FD) {
6410 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
6411 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
6412 if (Ctor->isDefaultConstructor())
6413 return Sema::CXXDefaultConstructor;
6414
6415 if (Ctor->isCopyConstructor())
6416 return Sema::CXXCopyConstructor;
6417
6418 if (Ctor->isMoveConstructor())
6419 return Sema::CXXMoveConstructor;
6420 }
6421
6422 if (MD->isCopyAssignmentOperator())
6423 return Sema::CXXCopyAssignment;
6424
6425 if (MD->isMoveAssignmentOperator())
6426 return Sema::CXXMoveAssignment;
6427
6428 if (isa<CXXDestructorDecl>(FD))
6429 return Sema::CXXDestructor;
6430 }
6431
6432 switch (FD->getDeclName().getCXXOverloadedOperator()) {
6433 case OO_EqualEqual:
6434 return DefaultedComparisonKind::Equal;
6435
6436 case OO_ExclaimEqual:
6437 return DefaultedComparisonKind::NotEqual;
6438
6439 case OO_Spaceship:
6440 // No point allowing this if <=> doesn't exist in the current language mode.
6441 if (!getLangOpts().CPlusPlus20)
6442 break;
6443 return DefaultedComparisonKind::ThreeWay;
6444
6445 case OO_Less:
6446 case OO_LessEqual:
6447 case OO_Greater:
6448 case OO_GreaterEqual:
6449 // No point allowing this if <=> doesn't exist in the current language mode.
6450 if (!getLangOpts().CPlusPlus20)
6451 break;
6452 return DefaultedComparisonKind::Relational;
6453
6454 default:
6455 break;
6456 }
6457
6458 // Not defaultable.
6459 return DefaultedFunctionKind();
6460 }
6461
DefineDefaultedFunction(Sema & S,FunctionDecl * FD,SourceLocation DefaultLoc)6462 static void DefineDefaultedFunction(Sema &S, FunctionDecl *FD,
6463 SourceLocation DefaultLoc) {
6464 Sema::DefaultedFunctionKind DFK = S.getDefaultedFunctionKind(FD);
6465 if (DFK.isComparison())
6466 return S.DefineDefaultedComparison(DefaultLoc, FD, DFK.asComparison());
6467
6468 switch (DFK.asSpecialMember()) {
6469 case Sema::CXXDefaultConstructor:
6470 S.DefineImplicitDefaultConstructor(DefaultLoc,
6471 cast<CXXConstructorDecl>(FD));
6472 break;
6473 case Sema::CXXCopyConstructor:
6474 S.DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
6475 break;
6476 case Sema::CXXCopyAssignment:
6477 S.DefineImplicitCopyAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
6478 break;
6479 case Sema::CXXDestructor:
6480 S.DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(FD));
6481 break;
6482 case Sema::CXXMoveConstructor:
6483 S.DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
6484 break;
6485 case Sema::CXXMoveAssignment:
6486 S.DefineImplicitMoveAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
6487 break;
6488 case Sema::CXXInvalid:
6489 llvm_unreachable("Invalid special member.");
6490 }
6491 }
6492
6493 /// Determine whether a type is permitted to be passed or returned in
6494 /// registers, per C++ [class.temporary]p3.
canPassInRegisters(Sema & S,CXXRecordDecl * D,TargetInfo::CallingConvKind CCK)6495 static bool canPassInRegisters(Sema &S, CXXRecordDecl *D,
6496 TargetInfo::CallingConvKind CCK) {
6497 if (D->isDependentType() || D->isInvalidDecl())
6498 return false;
6499
6500 // Clang <= 4 used the pre-C++11 rule, which ignores move operations.
6501 // The PS4 platform ABI follows the behavior of Clang 3.2.
6502 if (CCK == TargetInfo::CCK_ClangABI4OrPS4)
6503 return !D->hasNonTrivialDestructorForCall() &&
6504 !D->hasNonTrivialCopyConstructorForCall();
6505
6506 if (CCK == TargetInfo::CCK_MicrosoftWin64) {
6507 bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false;
6508 bool DtorIsTrivialForCall = false;
6509
6510 // If a class has at least one non-deleted, trivial copy constructor, it
6511 // is passed according to the C ABI. Otherwise, it is passed indirectly.
6512 //
6513 // Note: This permits classes with non-trivial copy or move ctors to be
6514 // passed in registers, so long as they *also* have a trivial copy ctor,
6515 // which is non-conforming.
6516 if (D->needsImplicitCopyConstructor()) {
6517 if (!D->defaultedCopyConstructorIsDeleted()) {
6518 if (D->hasTrivialCopyConstructor())
6519 CopyCtorIsTrivial = true;
6520 if (D->hasTrivialCopyConstructorForCall())
6521 CopyCtorIsTrivialForCall = true;
6522 }
6523 } else {
6524 for (const CXXConstructorDecl *CD : D->ctors()) {
6525 if (CD->isCopyConstructor() && !CD->isDeleted()) {
6526 if (CD->isTrivial())
6527 CopyCtorIsTrivial = true;
6528 if (CD->isTrivialForCall())
6529 CopyCtorIsTrivialForCall = true;
6530 }
6531 }
6532 }
6533
6534 if (D->needsImplicitDestructor()) {
6535 if (!D->defaultedDestructorIsDeleted() &&
6536 D->hasTrivialDestructorForCall())
6537 DtorIsTrivialForCall = true;
6538 } else if (const auto *DD = D->getDestructor()) {
6539 if (!DD->isDeleted() && DD->isTrivialForCall())
6540 DtorIsTrivialForCall = true;
6541 }
6542
6543 // If the copy ctor and dtor are both trivial-for-calls, pass direct.
6544 if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall)
6545 return true;
6546
6547 // If a class has a destructor, we'd really like to pass it indirectly
6548 // because it allows us to elide copies. Unfortunately, MSVC makes that
6549 // impossible for small types, which it will pass in a single register or
6550 // stack slot. Most objects with dtors are large-ish, so handle that early.
6551 // We can't call out all large objects as being indirect because there are
6552 // multiple x64 calling conventions and the C++ ABI code shouldn't dictate
6553 // how we pass large POD types.
6554
6555 // Note: This permits small classes with nontrivial destructors to be
6556 // passed in registers, which is non-conforming.
6557 bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64();
6558 uint64_t TypeSize = isAArch64 ? 128 : 64;
6559
6560 if (CopyCtorIsTrivial &&
6561 S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize)
6562 return true;
6563 return false;
6564 }
6565
6566 // Per C++ [class.temporary]p3, the relevant condition is:
6567 // each copy constructor, move constructor, and destructor of X is
6568 // either trivial or deleted, and X has at least one non-deleted copy
6569 // or move constructor
6570 bool HasNonDeletedCopyOrMove = false;
6571
6572 if (D->needsImplicitCopyConstructor() &&
6573 !D->defaultedCopyConstructorIsDeleted()) {
6574 if (!D->hasTrivialCopyConstructorForCall())
6575 return false;
6576 HasNonDeletedCopyOrMove = true;
6577 }
6578
6579 if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() &&
6580 !D->defaultedMoveConstructorIsDeleted()) {
6581 if (!D->hasTrivialMoveConstructorForCall())
6582 return false;
6583 HasNonDeletedCopyOrMove = true;
6584 }
6585
6586 if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() &&
6587 !D->hasTrivialDestructorForCall())
6588 return false;
6589
6590 for (const CXXMethodDecl *MD : D->methods()) {
6591 if (MD->isDeleted())
6592 continue;
6593
6594 auto *CD = dyn_cast<CXXConstructorDecl>(MD);
6595 if (CD && CD->isCopyOrMoveConstructor())
6596 HasNonDeletedCopyOrMove = true;
6597 else if (!isa<CXXDestructorDecl>(MD))
6598 continue;
6599
6600 if (!MD->isTrivialForCall())
6601 return false;
6602 }
6603
6604 return HasNonDeletedCopyOrMove;
6605 }
6606
6607 /// Report an error regarding overriding, along with any relevant
6608 /// overridden methods.
6609 ///
6610 /// \param DiagID the primary error to report.
6611 /// \param MD the overriding method.
6612 static bool
ReportOverrides(Sema & S,unsigned DiagID,const CXXMethodDecl * MD,llvm::function_ref<bool (const CXXMethodDecl *)> Report)6613 ReportOverrides(Sema &S, unsigned DiagID, const CXXMethodDecl *MD,
6614 llvm::function_ref<bool(const CXXMethodDecl *)> Report) {
6615 bool IssuedDiagnostic = false;
6616 for (const CXXMethodDecl *O : MD->overridden_methods()) {
6617 if (Report(O)) {
6618 if (!IssuedDiagnostic) {
6619 S.Diag(MD->getLocation(), DiagID) << MD->getDeclName();
6620 IssuedDiagnostic = true;
6621 }
6622 S.Diag(O->getLocation(), diag::note_overridden_virtual_function);
6623 }
6624 }
6625 return IssuedDiagnostic;
6626 }
6627
6628 /// Perform semantic checks on a class definition that has been
6629 /// completing, introducing implicitly-declared members, checking for
6630 /// abstract types, etc.
6631 ///
6632 /// \param S The scope in which the class was parsed. Null if we didn't just
6633 /// parse a class definition.
6634 /// \param Record The completed class.
CheckCompletedCXXClass(Scope * S,CXXRecordDecl * Record)6635 void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) {
6636 if (!Record)
6637 return;
6638
6639 if (Record->isAbstract() && !Record->isInvalidDecl()) {
6640 AbstractUsageInfo Info(*this, Record);
6641 CheckAbstractClassUsage(Info, Record);
6642 }
6643
6644 // If this is not an aggregate type and has no user-declared constructor,
6645 // complain about any non-static data members of reference or const scalar
6646 // type, since they will never get initializers.
6647 if (!Record->isInvalidDecl() && !Record->isDependentType() &&
6648 !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
6649 !Record->isLambda()) {
6650 bool Complained = false;
6651 for (const auto *F : Record->fields()) {
6652 if (F->hasInClassInitializer() || F->isUnnamedBitfield())
6653 continue;
6654
6655 if (F->getType()->isReferenceType() ||
6656 (F->getType().isConstQualified() && F->getType()->isScalarType())) {
6657 if (!Complained) {
6658 Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
6659 << Record->getTagKind() << Record;
6660 Complained = true;
6661 }
6662
6663 Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
6664 << F->getType()->isReferenceType()
6665 << F->getDeclName();
6666 }
6667 }
6668 }
6669
6670 if (Record->getIdentifier()) {
6671 // C++ [class.mem]p13:
6672 // If T is the name of a class, then each of the following shall have a
6673 // name different from T:
6674 // - every member of every anonymous union that is a member of class T.
6675 //
6676 // C++ [class.mem]p14:
6677 // In addition, if class T has a user-declared constructor (12.1), every
6678 // non-static data member of class T shall have a name different from T.
6679 DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
6680 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E;
6681 ++I) {
6682 NamedDecl *D = (*I)->getUnderlyingDecl();
6683 if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) &&
6684 Record->hasUserDeclaredConstructor()) ||
6685 isa<IndirectFieldDecl>(D)) {
6686 Diag((*I)->getLocation(), diag::err_member_name_of_class)
6687 << D->getDeclName();
6688 break;
6689 }
6690 }
6691 }
6692
6693 // Warn if the class has virtual methods but non-virtual public destructor.
6694 if (Record->isPolymorphic() && !Record->isDependentType()) {
6695 CXXDestructorDecl *dtor = Record->getDestructor();
6696 if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) &&
6697 !Record->hasAttr<FinalAttr>())
6698 Diag(dtor ? dtor->getLocation() : Record->getLocation(),
6699 diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
6700 }
6701
6702 if (Record->isAbstract()) {
6703 if (FinalAttr *FA = Record->getAttr<FinalAttr>()) {
6704 Diag(Record->getLocation(), diag::warn_abstract_final_class)
6705 << FA->isSpelledAsSealed();
6706 DiagnoseAbstractType(Record);
6707 }
6708 }
6709
6710 // Warn if the class has a final destructor but is not itself marked final.
6711 if (!Record->hasAttr<FinalAttr>()) {
6712 if (const CXXDestructorDecl *dtor = Record->getDestructor()) {
6713 if (const FinalAttr *FA = dtor->getAttr<FinalAttr>()) {
6714 Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class)
6715 << FA->isSpelledAsSealed()
6716 << FixItHint::CreateInsertion(
6717 getLocForEndOfToken(Record->getLocation()),
6718 (FA->isSpelledAsSealed() ? " sealed" : " final"));
6719 Diag(Record->getLocation(),
6720 diag::note_final_dtor_non_final_class_silence)
6721 << Context.getRecordType(Record) << FA->isSpelledAsSealed();
6722 }
6723 }
6724 }
6725
6726 // See if trivial_abi has to be dropped.
6727 if (Record->hasAttr<TrivialABIAttr>())
6728 checkIllFormedTrivialABIStruct(*Record);
6729
6730 // Set HasTrivialSpecialMemberForCall if the record has attribute
6731 // "trivial_abi".
6732 bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>();
6733
6734 if (HasTrivialABI)
6735 Record->setHasTrivialSpecialMemberForCall();
6736
6737 // Explicitly-defaulted secondary comparison functions (!=, <, <=, >, >=).
6738 // We check these last because they can depend on the properties of the
6739 // primary comparison functions (==, <=>).
6740 llvm::SmallVector<FunctionDecl*, 5> DefaultedSecondaryComparisons;
6741
6742 // Perform checks that can't be done until we know all the properties of a
6743 // member function (whether it's defaulted, deleted, virtual, overriding,
6744 // ...).
6745 auto CheckCompletedMemberFunction = [&](CXXMethodDecl *MD) {
6746 // A static function cannot override anything.
6747 if (MD->getStorageClass() == SC_Static) {
6748 if (ReportOverrides(*this, diag::err_static_overrides_virtual, MD,
6749 [](const CXXMethodDecl *) { return true; }))
6750 return;
6751 }
6752
6753 // A deleted function cannot override a non-deleted function and vice
6754 // versa.
6755 if (ReportOverrides(*this,
6756 MD->isDeleted() ? diag::err_deleted_override
6757 : diag::err_non_deleted_override,
6758 MD, [&](const CXXMethodDecl *V) {
6759 return MD->isDeleted() != V->isDeleted();
6760 })) {
6761 if (MD->isDefaulted() && MD->isDeleted())
6762 // Explain why this defaulted function was deleted.
6763 DiagnoseDeletedDefaultedFunction(MD);
6764 return;
6765 }
6766
6767 // A consteval function cannot override a non-consteval function and vice
6768 // versa.
6769 if (ReportOverrides(*this,
6770 MD->isConsteval() ? diag::err_consteval_override
6771 : diag::err_non_consteval_override,
6772 MD, [&](const CXXMethodDecl *V) {
6773 return MD->isConsteval() != V->isConsteval();
6774 })) {
6775 if (MD->isDefaulted() && MD->isDeleted())
6776 // Explain why this defaulted function was deleted.
6777 DiagnoseDeletedDefaultedFunction(MD);
6778 return;
6779 }
6780 };
6781
6782 auto CheckForDefaultedFunction = [&](FunctionDecl *FD) -> bool {
6783 if (!FD || FD->isInvalidDecl() || !FD->isExplicitlyDefaulted())
6784 return false;
6785
6786 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
6787 if (DFK.asComparison() == DefaultedComparisonKind::NotEqual ||
6788 DFK.asComparison() == DefaultedComparisonKind::Relational) {
6789 DefaultedSecondaryComparisons.push_back(FD);
6790 return true;
6791 }
6792
6793 CheckExplicitlyDefaultedFunction(S, FD);
6794 return false;
6795 };
6796
6797 auto CompleteMemberFunction = [&](CXXMethodDecl *M) {
6798 // Check whether the explicitly-defaulted members are valid.
6799 bool Incomplete = CheckForDefaultedFunction(M);
6800
6801 // Skip the rest of the checks for a member of a dependent class.
6802 if (Record->isDependentType())
6803 return;
6804
6805 // For an explicitly defaulted or deleted special member, we defer
6806 // determining triviality until the class is complete. That time is now!
6807 CXXSpecialMember CSM = getSpecialMember(M);
6808 if (!M->isImplicit() && !M->isUserProvided()) {
6809 if (CSM != CXXInvalid) {
6810 M->setTrivial(SpecialMemberIsTrivial(M, CSM));
6811 // Inform the class that we've finished declaring this member.
6812 Record->finishedDefaultedOrDeletedMember(M);
6813 M->setTrivialForCall(
6814 HasTrivialABI ||
6815 SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI));
6816 Record->setTrivialForCallFlags(M);
6817 }
6818 }
6819
6820 // Set triviality for the purpose of calls if this is a user-provided
6821 // copy/move constructor or destructor.
6822 if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor ||
6823 CSM == CXXDestructor) && M->isUserProvided()) {
6824 M->setTrivialForCall(HasTrivialABI);
6825 Record->setTrivialForCallFlags(M);
6826 }
6827
6828 if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() &&
6829 M->hasAttr<DLLExportAttr>()) {
6830 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
6831 M->isTrivial() &&
6832 (CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor ||
6833 CSM == CXXDestructor))
6834 M->dropAttr<DLLExportAttr>();
6835
6836 if (M->hasAttr<DLLExportAttr>()) {
6837 // Define after any fields with in-class initializers have been parsed.
6838 DelayedDllExportMemberFunctions.push_back(M);
6839 }
6840 }
6841
6842 // Define defaulted constexpr virtual functions that override a base class
6843 // function right away.
6844 // FIXME: We can defer doing this until the vtable is marked as used.
6845 if (M->isDefaulted() && M->isConstexpr() && M->size_overridden_methods())
6846 DefineDefaultedFunction(*this, M, M->getLocation());
6847
6848 if (!Incomplete)
6849 CheckCompletedMemberFunction(M);
6850 };
6851
6852 // Check the destructor before any other member function. We need to
6853 // determine whether it's trivial in order to determine whether the claas
6854 // type is a literal type, which is a prerequisite for determining whether
6855 // other special member functions are valid and whether they're implicitly
6856 // 'constexpr'.
6857 if (CXXDestructorDecl *Dtor = Record->getDestructor())
6858 CompleteMemberFunction(Dtor);
6859
6860 bool HasMethodWithOverrideControl = false,
6861 HasOverridingMethodWithoutOverrideControl = false;
6862 for (auto *D : Record->decls()) {
6863 if (auto *M = dyn_cast<CXXMethodDecl>(D)) {
6864 // FIXME: We could do this check for dependent types with non-dependent
6865 // bases.
6866 if (!Record->isDependentType()) {
6867 // See if a method overloads virtual methods in a base
6868 // class without overriding any.
6869 if (!M->isStatic())
6870 DiagnoseHiddenVirtualMethods(M);
6871 if (M->hasAttr<OverrideAttr>())
6872 HasMethodWithOverrideControl = true;
6873 else if (M->size_overridden_methods() > 0)
6874 HasOverridingMethodWithoutOverrideControl = true;
6875 }
6876
6877 if (!isa<CXXDestructorDecl>(M))
6878 CompleteMemberFunction(M);
6879 } else if (auto *F = dyn_cast<FriendDecl>(D)) {
6880 CheckForDefaultedFunction(
6881 dyn_cast_or_null<FunctionDecl>(F->getFriendDecl()));
6882 }
6883 }
6884
6885 if (HasOverridingMethodWithoutOverrideControl) {
6886 bool HasInconsistentOverrideControl = HasMethodWithOverrideControl;
6887 for (auto *M : Record->methods())
6888 DiagnoseAbsenceOfOverrideControl(M, HasInconsistentOverrideControl);
6889 }
6890
6891 // Check the defaulted secondary comparisons after any other member functions.
6892 for (FunctionDecl *FD : DefaultedSecondaryComparisons) {
6893 CheckExplicitlyDefaultedFunction(S, FD);
6894
6895 // If this is a member function, we deferred checking it until now.
6896 if (auto *MD = dyn_cast<CXXMethodDecl>(FD))
6897 CheckCompletedMemberFunction(MD);
6898 }
6899
6900 // ms_struct is a request to use the same ABI rules as MSVC. Check
6901 // whether this class uses any C++ features that are implemented
6902 // completely differently in MSVC, and if so, emit a diagnostic.
6903 // That diagnostic defaults to an error, but we allow projects to
6904 // map it down to a warning (or ignore it). It's a fairly common
6905 // practice among users of the ms_struct pragma to mass-annotate
6906 // headers, sweeping up a bunch of types that the project doesn't
6907 // really rely on MSVC-compatible layout for. We must therefore
6908 // support "ms_struct except for C++ stuff" as a secondary ABI.
6909 // Don't emit this diagnostic if the feature was enabled as a
6910 // language option (as opposed to via a pragma or attribute), as
6911 // the option -mms-bitfields otherwise essentially makes it impossible
6912 // to build C++ code, unless this diagnostic is turned off.
6913 if (Record->isMsStruct(Context) && !Context.getLangOpts().MSBitfields &&
6914 (Record->isPolymorphic() || Record->getNumBases())) {
6915 Diag(Record->getLocation(), diag::warn_cxx_ms_struct);
6916 }
6917
6918 checkClassLevelDLLAttribute(Record);
6919 checkClassLevelCodeSegAttribute(Record);
6920
6921 bool ClangABICompat4 =
6922 Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4;
6923 TargetInfo::CallingConvKind CCK =
6924 Context.getTargetInfo().getCallingConvKind(ClangABICompat4);
6925 bool CanPass = canPassInRegisters(*this, Record, CCK);
6926
6927 // Do not change ArgPassingRestrictions if it has already been set to
6928 // APK_CanNeverPassInRegs.
6929 if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs)
6930 Record->setArgPassingRestrictions(CanPass
6931 ? RecordDecl::APK_CanPassInRegs
6932 : RecordDecl::APK_CannotPassInRegs);
6933
6934 // If canPassInRegisters returns true despite the record having a non-trivial
6935 // destructor, the record is destructed in the callee. This happens only when
6936 // the record or one of its subobjects has a field annotated with trivial_abi
6937 // or a field qualified with ObjC __strong/__weak.
6938 if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee())
6939 Record->setParamDestroyedInCallee(true);
6940 else if (Record->hasNonTrivialDestructor())
6941 Record->setParamDestroyedInCallee(CanPass);
6942
6943 if (getLangOpts().ForceEmitVTables) {
6944 // If we want to emit all the vtables, we need to mark it as used. This
6945 // is especially required for cases like vtable assumption loads.
6946 MarkVTableUsed(Record->getInnerLocStart(), Record);
6947 }
6948
6949 if (getLangOpts().CUDA) {
6950 if (Record->hasAttr<CUDADeviceBuiltinSurfaceTypeAttr>())
6951 checkCUDADeviceBuiltinSurfaceClassTemplate(*this, Record);
6952 else if (Record->hasAttr<CUDADeviceBuiltinTextureTypeAttr>())
6953 checkCUDADeviceBuiltinTextureClassTemplate(*this, Record);
6954 }
6955 }
6956
6957 /// Look up the special member function that would be called by a special
6958 /// member function for a subobject of class type.
6959 ///
6960 /// \param Class The class type of the subobject.
6961 /// \param CSM The kind of special member function.
6962 /// \param FieldQuals If the subobject is a field, its cv-qualifiers.
6963 /// \param ConstRHS True if this is a copy operation with a const object
6964 /// on its RHS, that is, if the argument to the outer special member
6965 /// function is 'const' and this is not a field marked 'mutable'.
lookupCallFromSpecialMember(Sema & S,CXXRecordDecl * Class,Sema::CXXSpecialMember CSM,unsigned FieldQuals,bool ConstRHS)6966 static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember(
6967 Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM,
6968 unsigned FieldQuals, bool ConstRHS) {
6969 unsigned LHSQuals = 0;
6970 if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment)
6971 LHSQuals = FieldQuals;
6972
6973 unsigned RHSQuals = FieldQuals;
6974 if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
6975 RHSQuals = 0;
6976 else if (ConstRHS)
6977 RHSQuals |= Qualifiers::Const;
6978
6979 return S.LookupSpecialMember(Class, CSM,
6980 RHSQuals & Qualifiers::Const,
6981 RHSQuals & Qualifiers::Volatile,
6982 false,
6983 LHSQuals & Qualifiers::Const,
6984 LHSQuals & Qualifiers::Volatile);
6985 }
6986
6987 class Sema::InheritedConstructorInfo {
6988 Sema &S;
6989 SourceLocation UseLoc;
6990
6991 /// A mapping from the base classes through which the constructor was
6992 /// inherited to the using shadow declaration in that base class (or a null
6993 /// pointer if the constructor was declared in that base class).
6994 llvm::DenseMap<CXXRecordDecl *, ConstructorUsingShadowDecl *>
6995 InheritedFromBases;
6996
6997 public:
InheritedConstructorInfo(Sema & S,SourceLocation UseLoc,ConstructorUsingShadowDecl * Shadow)6998 InheritedConstructorInfo(Sema &S, SourceLocation UseLoc,
6999 ConstructorUsingShadowDecl *Shadow)
7000 : S(S), UseLoc(UseLoc) {
7001 bool DiagnosedMultipleConstructedBases = false;
7002 CXXRecordDecl *ConstructedBase = nullptr;
7003 UsingDecl *ConstructedBaseUsing = nullptr;
7004
7005 // Find the set of such base class subobjects and check that there's a
7006 // unique constructed subobject.
7007 for (auto *D : Shadow->redecls()) {
7008 auto *DShadow = cast<ConstructorUsingShadowDecl>(D);
7009 auto *DNominatedBase = DShadow->getNominatedBaseClass();
7010 auto *DConstructedBase = DShadow->getConstructedBaseClass();
7011
7012 InheritedFromBases.insert(
7013 std::make_pair(DNominatedBase->getCanonicalDecl(),
7014 DShadow->getNominatedBaseClassShadowDecl()));
7015 if (DShadow->constructsVirtualBase())
7016 InheritedFromBases.insert(
7017 std::make_pair(DConstructedBase->getCanonicalDecl(),
7018 DShadow->getConstructedBaseClassShadowDecl()));
7019 else
7020 assert(DNominatedBase == DConstructedBase);
7021
7022 // [class.inhctor.init]p2:
7023 // If the constructor was inherited from multiple base class subobjects
7024 // of type B, the program is ill-formed.
7025 if (!ConstructedBase) {
7026 ConstructedBase = DConstructedBase;
7027 ConstructedBaseUsing = D->getUsingDecl();
7028 } else if (ConstructedBase != DConstructedBase &&
7029 !Shadow->isInvalidDecl()) {
7030 if (!DiagnosedMultipleConstructedBases) {
7031 S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor)
7032 << Shadow->getTargetDecl();
7033 S.Diag(ConstructedBaseUsing->getLocation(),
7034 diag::note_ambiguous_inherited_constructor_using)
7035 << ConstructedBase;
7036 DiagnosedMultipleConstructedBases = true;
7037 }
7038 S.Diag(D->getUsingDecl()->getLocation(),
7039 diag::note_ambiguous_inherited_constructor_using)
7040 << DConstructedBase;
7041 }
7042 }
7043
7044 if (DiagnosedMultipleConstructedBases)
7045 Shadow->setInvalidDecl();
7046 }
7047
7048 /// Find the constructor to use for inherited construction of a base class,
7049 /// and whether that base class constructor inherits the constructor from a
7050 /// virtual base class (in which case it won't actually invoke it).
7051 std::pair<CXXConstructorDecl *, bool>
findConstructorForBase(CXXRecordDecl * Base,CXXConstructorDecl * Ctor) const7052 findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const {
7053 auto It = InheritedFromBases.find(Base->getCanonicalDecl());
7054 if (It == InheritedFromBases.end())
7055 return std::make_pair(nullptr, false);
7056
7057 // This is an intermediary class.
7058 if (It->second)
7059 return std::make_pair(
7060 S.findInheritingConstructor(UseLoc, Ctor, It->second),
7061 It->second->constructsVirtualBase());
7062
7063 // This is the base class from which the constructor was inherited.
7064 return std::make_pair(Ctor, false);
7065 }
7066 };
7067
7068 /// Is the special member function which would be selected to perform the
7069 /// specified operation on the specified class type a constexpr constructor?
7070 static bool
specialMemberIsConstexpr(Sema & S,CXXRecordDecl * ClassDecl,Sema::CXXSpecialMember CSM,unsigned Quals,bool ConstRHS,CXXConstructorDecl * InheritedCtor=nullptr,Sema::InheritedConstructorInfo * Inherited=nullptr)7071 specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
7072 Sema::CXXSpecialMember CSM, unsigned Quals,
7073 bool ConstRHS,
7074 CXXConstructorDecl *InheritedCtor = nullptr,
7075 Sema::InheritedConstructorInfo *Inherited = nullptr) {
7076 // If we're inheriting a constructor, see if we need to call it for this base
7077 // class.
7078 if (InheritedCtor) {
7079 assert(CSM == Sema::CXXDefaultConstructor);
7080 auto BaseCtor =
7081 Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first;
7082 if (BaseCtor)
7083 return BaseCtor->isConstexpr();
7084 }
7085
7086 if (CSM == Sema::CXXDefaultConstructor)
7087 return ClassDecl->hasConstexprDefaultConstructor();
7088 if (CSM == Sema::CXXDestructor)
7089 return ClassDecl->hasConstexprDestructor();
7090
7091 Sema::SpecialMemberOverloadResult SMOR =
7092 lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS);
7093 if (!SMOR.getMethod())
7094 // A constructor we wouldn't select can't be "involved in initializing"
7095 // anything.
7096 return true;
7097 return SMOR.getMethod()->isConstexpr();
7098 }
7099
7100 /// Determine whether the specified special member function would be constexpr
7101 /// if it were implicitly defined.
defaultedSpecialMemberIsConstexpr(Sema & S,CXXRecordDecl * ClassDecl,Sema::CXXSpecialMember CSM,bool ConstArg,CXXConstructorDecl * InheritedCtor=nullptr,Sema::InheritedConstructorInfo * Inherited=nullptr)7102 static bool defaultedSpecialMemberIsConstexpr(
7103 Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM,
7104 bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr,
7105 Sema::InheritedConstructorInfo *Inherited = nullptr) {
7106 if (!S.getLangOpts().CPlusPlus11)
7107 return false;
7108
7109 // C++11 [dcl.constexpr]p4:
7110 // In the definition of a constexpr constructor [...]
7111 bool Ctor = true;
7112 switch (CSM) {
7113 case Sema::CXXDefaultConstructor:
7114 if (Inherited)
7115 break;
7116 // Since default constructor lookup is essentially trivial (and cannot
7117 // involve, for instance, template instantiation), we compute whether a
7118 // defaulted default constructor is constexpr directly within CXXRecordDecl.
7119 //
7120 // This is important for performance; we need to know whether the default
7121 // constructor is constexpr to determine whether the type is a literal type.
7122 return ClassDecl->defaultedDefaultConstructorIsConstexpr();
7123
7124 case Sema::CXXCopyConstructor:
7125 case Sema::CXXMoveConstructor:
7126 // For copy or move constructors, we need to perform overload resolution.
7127 break;
7128
7129 case Sema::CXXCopyAssignment:
7130 case Sema::CXXMoveAssignment:
7131 if (!S.getLangOpts().CPlusPlus14)
7132 return false;
7133 // In C++1y, we need to perform overload resolution.
7134 Ctor = false;
7135 break;
7136
7137 case Sema::CXXDestructor:
7138 return ClassDecl->defaultedDestructorIsConstexpr();
7139
7140 case Sema::CXXInvalid:
7141 return false;
7142 }
7143
7144 // -- if the class is a non-empty union, or for each non-empty anonymous
7145 // union member of a non-union class, exactly one non-static data member
7146 // shall be initialized; [DR1359]
7147 //
7148 // If we squint, this is guaranteed, since exactly one non-static data member
7149 // will be initialized (if the constructor isn't deleted), we just don't know
7150 // which one.
7151 if (Ctor && ClassDecl->isUnion())
7152 return CSM == Sema::CXXDefaultConstructor
7153 ? ClassDecl->hasInClassInitializer() ||
7154 !ClassDecl->hasVariantMembers()
7155 : true;
7156
7157 // -- the class shall not have any virtual base classes;
7158 if (Ctor && ClassDecl->getNumVBases())
7159 return false;
7160
7161 // C++1y [class.copy]p26:
7162 // -- [the class] is a literal type, and
7163 if (!Ctor && !ClassDecl->isLiteral())
7164 return false;
7165
7166 // -- every constructor involved in initializing [...] base class
7167 // sub-objects shall be a constexpr constructor;
7168 // -- the assignment operator selected to copy/move each direct base
7169 // class is a constexpr function, and
7170 for (const auto &B : ClassDecl->bases()) {
7171 const RecordType *BaseType = B.getType()->getAs<RecordType>();
7172 if (!BaseType) continue;
7173
7174 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
7175 if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg,
7176 InheritedCtor, Inherited))
7177 return false;
7178 }
7179
7180 // -- every constructor involved in initializing non-static data members
7181 // [...] shall be a constexpr constructor;
7182 // -- every non-static data member and base class sub-object shall be
7183 // initialized
7184 // -- for each non-static data member of X that is of class type (or array
7185 // thereof), the assignment operator selected to copy/move that member is
7186 // a constexpr function
7187 for (const auto *F : ClassDecl->fields()) {
7188 if (F->isInvalidDecl())
7189 continue;
7190 if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer())
7191 continue;
7192 QualType BaseType = S.Context.getBaseElementType(F->getType());
7193 if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
7194 CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
7195 if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM,
7196 BaseType.getCVRQualifiers(),
7197 ConstArg && !F->isMutable()))
7198 return false;
7199 } else if (CSM == Sema::CXXDefaultConstructor) {
7200 return false;
7201 }
7202 }
7203
7204 // All OK, it's constexpr!
7205 return true;
7206 }
7207
7208 namespace {
7209 /// RAII object to register a defaulted function as having its exception
7210 /// specification computed.
7211 struct ComputingExceptionSpec {
7212 Sema &S;
7213
ComputingExceptionSpec__anonb2a824811e11::ComputingExceptionSpec7214 ComputingExceptionSpec(Sema &S, FunctionDecl *FD, SourceLocation Loc)
7215 : S(S) {
7216 Sema::CodeSynthesisContext Ctx;
7217 Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation;
7218 Ctx.PointOfInstantiation = Loc;
7219 Ctx.Entity = FD;
7220 S.pushCodeSynthesisContext(Ctx);
7221 }
~ComputingExceptionSpec__anonb2a824811e11::ComputingExceptionSpec7222 ~ComputingExceptionSpec() {
7223 S.popCodeSynthesisContext();
7224 }
7225 };
7226 }
7227
7228 static Sema::ImplicitExceptionSpecification
7229 ComputeDefaultedSpecialMemberExceptionSpec(
7230 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
7231 Sema::InheritedConstructorInfo *ICI);
7232
7233 static Sema::ImplicitExceptionSpecification
7234 ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
7235 FunctionDecl *FD,
7236 Sema::DefaultedComparisonKind DCK);
7237
7238 static Sema::ImplicitExceptionSpecification
computeImplicitExceptionSpec(Sema & S,SourceLocation Loc,FunctionDecl * FD)7239 computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, FunctionDecl *FD) {
7240 auto DFK = S.getDefaultedFunctionKind(FD);
7241 if (DFK.isSpecialMember())
7242 return ComputeDefaultedSpecialMemberExceptionSpec(
7243 S, Loc, cast<CXXMethodDecl>(FD), DFK.asSpecialMember(), nullptr);
7244 if (DFK.isComparison())
7245 return ComputeDefaultedComparisonExceptionSpec(S, Loc, FD,
7246 DFK.asComparison());
7247
7248 auto *CD = cast<CXXConstructorDecl>(FD);
7249 assert(CD->getInheritedConstructor() &&
7250 "only defaulted functions and inherited constructors have implicit "
7251 "exception specs");
7252 Sema::InheritedConstructorInfo ICI(
7253 S, Loc, CD->getInheritedConstructor().getShadowDecl());
7254 return ComputeDefaultedSpecialMemberExceptionSpec(
7255 S, Loc, CD, Sema::CXXDefaultConstructor, &ICI);
7256 }
7257
getImplicitMethodEPI(Sema & S,CXXMethodDecl * MD)7258 static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S,
7259 CXXMethodDecl *MD) {
7260 FunctionProtoType::ExtProtoInfo EPI;
7261
7262 // Build an exception specification pointing back at this member.
7263 EPI.ExceptionSpec.Type = EST_Unevaluated;
7264 EPI.ExceptionSpec.SourceDecl = MD;
7265
7266 // Set the calling convention to the default for C++ instance methods.
7267 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(
7268 S.Context.getDefaultCallingConvention(/*IsVariadic=*/false,
7269 /*IsCXXMethod=*/true));
7270 return EPI;
7271 }
7272
EvaluateImplicitExceptionSpec(SourceLocation Loc,FunctionDecl * FD)7273 void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD) {
7274 const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>();
7275 if (FPT->getExceptionSpecType() != EST_Unevaluated)
7276 return;
7277
7278 // Evaluate the exception specification.
7279 auto IES = computeImplicitExceptionSpec(*this, Loc, FD);
7280 auto ESI = IES.getExceptionSpec();
7281
7282 // Update the type of the special member to use it.
7283 UpdateExceptionSpec(FD, ESI);
7284 }
7285
CheckExplicitlyDefaultedFunction(Scope * S,FunctionDecl * FD)7286 void Sema::CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *FD) {
7287 assert(FD->isExplicitlyDefaulted() && "not explicitly-defaulted");
7288
7289 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
7290 if (!DefKind) {
7291 assert(FD->getDeclContext()->isDependentContext());
7292 return;
7293 }
7294
7295 if (DefKind.isSpecialMember()
7296 ? CheckExplicitlyDefaultedSpecialMember(cast<CXXMethodDecl>(FD),
7297 DefKind.asSpecialMember())
7298 : CheckExplicitlyDefaultedComparison(S, FD, DefKind.asComparison()))
7299 FD->setInvalidDecl();
7300 }
7301
CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl * MD,CXXSpecialMember CSM)7302 bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD,
7303 CXXSpecialMember CSM) {
7304 CXXRecordDecl *RD = MD->getParent();
7305
7306 assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&
7307 "not an explicitly-defaulted special member");
7308
7309 // Defer all checking for special members of a dependent type.
7310 if (RD->isDependentType())
7311 return false;
7312
7313 // Whether this was the first-declared instance of the constructor.
7314 // This affects whether we implicitly add an exception spec and constexpr.
7315 bool First = MD == MD->getCanonicalDecl();
7316
7317 bool HadError = false;
7318
7319 // C++11 [dcl.fct.def.default]p1:
7320 // A function that is explicitly defaulted shall
7321 // -- be a special member function [...] (checked elsewhere),
7322 // -- have the same type (except for ref-qualifiers, and except that a
7323 // copy operation can take a non-const reference) as an implicit
7324 // declaration, and
7325 // -- not have default arguments.
7326 // C++2a changes the second bullet to instead delete the function if it's
7327 // defaulted on its first declaration, unless it's "an assignment operator,
7328 // and its return type differs or its parameter type is not a reference".
7329 bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus20 && First;
7330 bool ShouldDeleteForTypeMismatch = false;
7331 unsigned ExpectedParams = 1;
7332 if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
7333 ExpectedParams = 0;
7334 if (MD->getNumParams() != ExpectedParams) {
7335 // This checks for default arguments: a copy or move constructor with a
7336 // default argument is classified as a default constructor, and assignment
7337 // operations and destructors can't have default arguments.
7338 Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
7339 << CSM << MD->getSourceRange();
7340 HadError = true;
7341 } else if (MD->isVariadic()) {
7342 if (DeleteOnTypeMismatch)
7343 ShouldDeleteForTypeMismatch = true;
7344 else {
7345 Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic)
7346 << CSM << MD->getSourceRange();
7347 HadError = true;
7348 }
7349 }
7350
7351 const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();
7352
7353 bool CanHaveConstParam = false;
7354 if (CSM == CXXCopyConstructor)
7355 CanHaveConstParam = RD->implicitCopyConstructorHasConstParam();
7356 else if (CSM == CXXCopyAssignment)
7357 CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam();
7358
7359 QualType ReturnType = Context.VoidTy;
7360 if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
7361 // Check for return type matching.
7362 ReturnType = Type->getReturnType();
7363
7364 QualType DeclType = Context.getTypeDeclType(RD);
7365 DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace());
7366 QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType);
7367
7368 if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
7369 Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
7370 << (CSM == CXXMoveAssignment) << ExpectedReturnType;
7371 HadError = true;
7372 }
7373
7374 // A defaulted special member cannot have cv-qualifiers.
7375 if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) {
7376 if (DeleteOnTypeMismatch)
7377 ShouldDeleteForTypeMismatch = true;
7378 else {
7379 Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
7380 << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14;
7381 HadError = true;
7382 }
7383 }
7384 }
7385
7386 // Check for parameter type matching.
7387 QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType();
7388 bool HasConstParam = false;
7389 if (ExpectedParams && ArgType->isReferenceType()) {
7390 // Argument must be reference to possibly-const T.
7391 QualType ReferentType = ArgType->getPointeeType();
7392 HasConstParam = ReferentType.isConstQualified();
7393
7394 if (ReferentType.isVolatileQualified()) {
7395 if (DeleteOnTypeMismatch)
7396 ShouldDeleteForTypeMismatch = true;
7397 else {
7398 Diag(MD->getLocation(),
7399 diag::err_defaulted_special_member_volatile_param) << CSM;
7400 HadError = true;
7401 }
7402 }
7403
7404 if (HasConstParam && !CanHaveConstParam) {
7405 if (DeleteOnTypeMismatch)
7406 ShouldDeleteForTypeMismatch = true;
7407 else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
7408 Diag(MD->getLocation(),
7409 diag::err_defaulted_special_member_copy_const_param)
7410 << (CSM == CXXCopyAssignment);
7411 // FIXME: Explain why this special member can't be const.
7412 HadError = true;
7413 } else {
7414 Diag(MD->getLocation(),
7415 diag::err_defaulted_special_member_move_const_param)
7416 << (CSM == CXXMoveAssignment);
7417 HadError = true;
7418 }
7419 }
7420 } else if (ExpectedParams) {
7421 // A copy assignment operator can take its argument by value, but a
7422 // defaulted one cannot.
7423 assert(CSM == CXXCopyAssignment && "unexpected non-ref argument");
7424 Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
7425 HadError = true;
7426 }
7427
7428 // C++11 [dcl.fct.def.default]p2:
7429 // An explicitly-defaulted function may be declared constexpr only if it
7430 // would have been implicitly declared as constexpr,
7431 // Do not apply this rule to members of class templates, since core issue 1358
7432 // makes such functions always instantiate to constexpr functions. For
7433 // functions which cannot be constexpr (for non-constructors in C++11 and for
7434 // destructors in C++14 and C++17), this is checked elsewhere.
7435 //
7436 // FIXME: This should not apply if the member is deleted.
7437 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
7438 HasConstParam);
7439 if ((getLangOpts().CPlusPlus20 ||
7440 (getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD)
7441 : isa<CXXConstructorDecl>(MD))) &&
7442 MD->isConstexpr() && !Constexpr &&
7443 MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
7444 Diag(MD->getBeginLoc(), MD->isConsteval()
7445 ? diag::err_incorrect_defaulted_consteval
7446 : diag::err_incorrect_defaulted_constexpr)
7447 << CSM;
7448 // FIXME: Explain why the special member can't be constexpr.
7449 HadError = true;
7450 }
7451
7452 if (First) {
7453 // C++2a [dcl.fct.def.default]p3:
7454 // If a function is explicitly defaulted on its first declaration, it is
7455 // implicitly considered to be constexpr if the implicit declaration
7456 // would be.
7457 MD->setConstexprKind(Constexpr ? (MD->isConsteval()
7458 ? ConstexprSpecKind::Consteval
7459 : ConstexprSpecKind::Constexpr)
7460 : ConstexprSpecKind::Unspecified);
7461
7462 if (!Type->hasExceptionSpec()) {
7463 // C++2a [except.spec]p3:
7464 // If a declaration of a function does not have a noexcept-specifier
7465 // [and] is defaulted on its first declaration, [...] the exception
7466 // specification is as specified below
7467 FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
7468 EPI.ExceptionSpec.Type = EST_Unevaluated;
7469 EPI.ExceptionSpec.SourceDecl = MD;
7470 MD->setType(Context.getFunctionType(ReturnType,
7471 llvm::makeArrayRef(&ArgType,
7472 ExpectedParams),
7473 EPI));
7474 }
7475 }
7476
7477 if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) {
7478 if (First) {
7479 SetDeclDeleted(MD, MD->getLocation());
7480 if (!inTemplateInstantiation() && !HadError) {
7481 Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM;
7482 if (ShouldDeleteForTypeMismatch) {
7483 Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM;
7484 } else {
7485 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
7486 }
7487 }
7488 if (ShouldDeleteForTypeMismatch && !HadError) {
7489 Diag(MD->getLocation(),
7490 diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM;
7491 }
7492 } else {
7493 // C++11 [dcl.fct.def.default]p4:
7494 // [For a] user-provided explicitly-defaulted function [...] if such a
7495 // function is implicitly defined as deleted, the program is ill-formed.
7496 Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
7497 assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl");
7498 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
7499 HadError = true;
7500 }
7501 }
7502
7503 return HadError;
7504 }
7505
7506 namespace {
7507 /// Helper class for building and checking a defaulted comparison.
7508 ///
7509 /// Defaulted functions are built in two phases:
7510 ///
7511 /// * First, the set of operations that the function will perform are
7512 /// identified, and some of them are checked. If any of the checked
7513 /// operations is invalid in certain ways, the comparison function is
7514 /// defined as deleted and no body is built.
7515 /// * Then, if the function is not defined as deleted, the body is built.
7516 ///
7517 /// This is accomplished by performing two visitation steps over the eventual
7518 /// body of the function.
7519 template<typename Derived, typename ResultList, typename Result,
7520 typename Subobject>
7521 class DefaultedComparisonVisitor {
7522 public:
7523 using DefaultedComparisonKind = Sema::DefaultedComparisonKind;
7524
DefaultedComparisonVisitor(Sema & S,CXXRecordDecl * RD,FunctionDecl * FD,DefaultedComparisonKind DCK)7525 DefaultedComparisonVisitor(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7526 DefaultedComparisonKind DCK)
7527 : S(S), RD(RD), FD(FD), DCK(DCK) {
7528 if (auto *Info = FD->getDefaultedFunctionInfo()) {
7529 // FIXME: Change CreateOverloadedBinOp to take an ArrayRef instead of an
7530 // UnresolvedSet to avoid this copy.
7531 Fns.assign(Info->getUnqualifiedLookups().begin(),
7532 Info->getUnqualifiedLookups().end());
7533 }
7534 }
7535
visit()7536 ResultList visit() {
7537 // The type of an lvalue naming a parameter of this function.
7538 QualType ParamLvalType =
7539 FD->getParamDecl(0)->getType().getNonReferenceType();
7540
7541 ResultList Results;
7542
7543 switch (DCK) {
7544 case DefaultedComparisonKind::None:
7545 llvm_unreachable("not a defaulted comparison");
7546
7547 case DefaultedComparisonKind::Equal:
7548 case DefaultedComparisonKind::ThreeWay:
7549 getDerived().visitSubobjects(Results, RD, ParamLvalType.getQualifiers());
7550 return Results;
7551
7552 case DefaultedComparisonKind::NotEqual:
7553 case DefaultedComparisonKind::Relational:
7554 Results.add(getDerived().visitExpandedSubobject(
7555 ParamLvalType, getDerived().getCompleteObject()));
7556 return Results;
7557 }
7558 llvm_unreachable("");
7559 }
7560
7561 protected:
getDerived()7562 Derived &getDerived() { return static_cast<Derived&>(*this); }
7563
7564 /// Visit the expanded list of subobjects of the given type, as specified in
7565 /// C++2a [class.compare.default].
7566 ///
7567 /// \return \c true if the ResultList object said we're done, \c false if not.
visitSubobjects(ResultList & Results,CXXRecordDecl * Record,Qualifiers Quals)7568 bool visitSubobjects(ResultList &Results, CXXRecordDecl *Record,
7569 Qualifiers Quals) {
7570 // C++2a [class.compare.default]p4:
7571 // The direct base class subobjects of C
7572 for (CXXBaseSpecifier &Base : Record->bases())
7573 if (Results.add(getDerived().visitSubobject(
7574 S.Context.getQualifiedType(Base.getType(), Quals),
7575 getDerived().getBase(&Base))))
7576 return true;
7577
7578 // followed by the non-static data members of C
7579 for (FieldDecl *Field : Record->fields()) {
7580 // Recursively expand anonymous structs.
7581 if (Field->isAnonymousStructOrUnion()) {
7582 if (visitSubobjects(Results, Field->getType()->getAsCXXRecordDecl(),
7583 Quals))
7584 return true;
7585 continue;
7586 }
7587
7588 // Figure out the type of an lvalue denoting this field.
7589 Qualifiers FieldQuals = Quals;
7590 if (Field->isMutable())
7591 FieldQuals.removeConst();
7592 QualType FieldType =
7593 S.Context.getQualifiedType(Field->getType(), FieldQuals);
7594
7595 if (Results.add(getDerived().visitSubobject(
7596 FieldType, getDerived().getField(Field))))
7597 return true;
7598 }
7599
7600 // form a list of subobjects.
7601 return false;
7602 }
7603
visitSubobject(QualType Type,Subobject Subobj)7604 Result visitSubobject(QualType Type, Subobject Subobj) {
7605 // In that list, any subobject of array type is recursively expanded
7606 const ArrayType *AT = S.Context.getAsArrayType(Type);
7607 if (auto *CAT = dyn_cast_or_null<ConstantArrayType>(AT))
7608 return getDerived().visitSubobjectArray(CAT->getElementType(),
7609 CAT->getSize(), Subobj);
7610 return getDerived().visitExpandedSubobject(Type, Subobj);
7611 }
7612
visitSubobjectArray(QualType Type,const llvm::APInt & Size,Subobject Subobj)7613 Result visitSubobjectArray(QualType Type, const llvm::APInt &Size,
7614 Subobject Subobj) {
7615 return getDerived().visitSubobject(Type, Subobj);
7616 }
7617
7618 protected:
7619 Sema &S;
7620 CXXRecordDecl *RD;
7621 FunctionDecl *FD;
7622 DefaultedComparisonKind DCK;
7623 UnresolvedSet<16> Fns;
7624 };
7625
7626 /// Information about a defaulted comparison, as determined by
7627 /// DefaultedComparisonAnalyzer.
7628 struct DefaultedComparisonInfo {
7629 bool Deleted = false;
7630 bool Constexpr = true;
7631 ComparisonCategoryType Category = ComparisonCategoryType::StrongOrdering;
7632
deleted__anonb2a824811f11::DefaultedComparisonInfo7633 static DefaultedComparisonInfo deleted() {
7634 DefaultedComparisonInfo Deleted;
7635 Deleted.Deleted = true;
7636 return Deleted;
7637 }
7638
add__anonb2a824811f11::DefaultedComparisonInfo7639 bool add(const DefaultedComparisonInfo &R) {
7640 Deleted |= R.Deleted;
7641 Constexpr &= R.Constexpr;
7642 Category = commonComparisonType(Category, R.Category);
7643 return Deleted;
7644 }
7645 };
7646
7647 /// An element in the expanded list of subobjects of a defaulted comparison, as
7648 /// specified in C++2a [class.compare.default]p4.
7649 struct DefaultedComparisonSubobject {
7650 enum { CompleteObject, Member, Base } Kind;
7651 NamedDecl *Decl;
7652 SourceLocation Loc;
7653 };
7654
7655 /// A visitor over the notional body of a defaulted comparison that determines
7656 /// whether that body would be deleted or constexpr.
7657 class DefaultedComparisonAnalyzer
7658 : public DefaultedComparisonVisitor<DefaultedComparisonAnalyzer,
7659 DefaultedComparisonInfo,
7660 DefaultedComparisonInfo,
7661 DefaultedComparisonSubobject> {
7662 public:
7663 enum DiagnosticKind { NoDiagnostics, ExplainDeleted, ExplainConstexpr };
7664
7665 private:
7666 DiagnosticKind Diagnose;
7667
7668 public:
7669 using Base = DefaultedComparisonVisitor;
7670 using Result = DefaultedComparisonInfo;
7671 using Subobject = DefaultedComparisonSubobject;
7672
7673 friend Base;
7674
DefaultedComparisonAnalyzer(Sema & S,CXXRecordDecl * RD,FunctionDecl * FD,DefaultedComparisonKind DCK,DiagnosticKind Diagnose=NoDiagnostics)7675 DefaultedComparisonAnalyzer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7676 DefaultedComparisonKind DCK,
7677 DiagnosticKind Diagnose = NoDiagnostics)
7678 : Base(S, RD, FD, DCK), Diagnose(Diagnose) {}
7679
visit()7680 Result visit() {
7681 if ((DCK == DefaultedComparisonKind::Equal ||
7682 DCK == DefaultedComparisonKind::ThreeWay) &&
7683 RD->hasVariantMembers()) {
7684 // C++2a [class.compare.default]p2 [P2002R0]:
7685 // A defaulted comparison operator function for class C is defined as
7686 // deleted if [...] C has variant members.
7687 if (Diagnose == ExplainDeleted) {
7688 S.Diag(FD->getLocation(), diag::note_defaulted_comparison_union)
7689 << FD << RD->isUnion() << RD;
7690 }
7691 return Result::deleted();
7692 }
7693
7694 return Base::visit();
7695 }
7696
7697 private:
getCompleteObject()7698 Subobject getCompleteObject() {
7699 return Subobject{Subobject::CompleteObject, RD, FD->getLocation()};
7700 }
7701
getBase(CXXBaseSpecifier * Base)7702 Subobject getBase(CXXBaseSpecifier *Base) {
7703 return Subobject{Subobject::Base, Base->getType()->getAsCXXRecordDecl(),
7704 Base->getBaseTypeLoc()};
7705 }
7706
getField(FieldDecl * Field)7707 Subobject getField(FieldDecl *Field) {
7708 return Subobject{Subobject::Member, Field, Field->getLocation()};
7709 }
7710
visitExpandedSubobject(QualType Type,Subobject Subobj)7711 Result visitExpandedSubobject(QualType Type, Subobject Subobj) {
7712 // C++2a [class.compare.default]p2 [P2002R0]:
7713 // A defaulted <=> or == operator function for class C is defined as
7714 // deleted if any non-static data member of C is of reference type
7715 if (Type->isReferenceType()) {
7716 if (Diagnose == ExplainDeleted) {
7717 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_reference_member)
7718 << FD << RD;
7719 }
7720 return Result::deleted();
7721 }
7722
7723 // [...] Let xi be an lvalue denoting the ith element [...]
7724 OpaqueValueExpr Xi(FD->getLocation(), Type, VK_LValue);
7725 Expr *Args[] = {&Xi, &Xi};
7726
7727 // All operators start by trying to apply that same operator recursively.
7728 OverloadedOperatorKind OO = FD->getOverloadedOperator();
7729 assert(OO != OO_None && "not an overloaded operator!");
7730 return visitBinaryOperator(OO, Args, Subobj);
7731 }
7732
7733 Result
visitBinaryOperator(OverloadedOperatorKind OO,ArrayRef<Expr * > Args,Subobject Subobj,OverloadCandidateSet * SpaceshipCandidates=nullptr)7734 visitBinaryOperator(OverloadedOperatorKind OO, ArrayRef<Expr *> Args,
7735 Subobject Subobj,
7736 OverloadCandidateSet *SpaceshipCandidates = nullptr) {
7737 // Note that there is no need to consider rewritten candidates here if
7738 // we've already found there is no viable 'operator<=>' candidate (and are
7739 // considering synthesizing a '<=>' from '==' and '<').
7740 OverloadCandidateSet CandidateSet(
7741 FD->getLocation(), OverloadCandidateSet::CSK_Operator,
7742 OverloadCandidateSet::OperatorRewriteInfo(
7743 OO, /*AllowRewrittenCandidates=*/!SpaceshipCandidates));
7744
7745 /// C++2a [class.compare.default]p1 [P2002R0]:
7746 /// [...] the defaulted function itself is never a candidate for overload
7747 /// resolution [...]
7748 CandidateSet.exclude(FD);
7749
7750 if (Args[0]->getType()->isOverloadableType())
7751 S.LookupOverloadedBinOp(CandidateSet, OO, Fns, Args);
7752 else if (OO == OO_EqualEqual ||
7753 !Args[0]->getType()->isFunctionPointerType()) {
7754 // FIXME: We determine whether this is a valid expression by checking to
7755 // see if there's a viable builtin operator candidate for it. That isn't
7756 // really what the rules ask us to do, but should give the right results.
7757 //
7758 // Note that the builtin operator for relational comparisons on function
7759 // pointers is the only known case which cannot be used.
7760 S.AddBuiltinOperatorCandidates(OO, FD->getLocation(), Args, CandidateSet);
7761 }
7762
7763 Result R;
7764
7765 OverloadCandidateSet::iterator Best;
7766 switch (CandidateSet.BestViableFunction(S, FD->getLocation(), Best)) {
7767 case OR_Success: {
7768 // C++2a [class.compare.secondary]p2 [P2002R0]:
7769 // The operator function [...] is defined as deleted if [...] the
7770 // candidate selected by overload resolution is not a rewritten
7771 // candidate.
7772 if ((DCK == DefaultedComparisonKind::NotEqual ||
7773 DCK == DefaultedComparisonKind::Relational) &&
7774 !Best->RewriteKind) {
7775 if (Diagnose == ExplainDeleted) {
7776 S.Diag(Best->Function->getLocation(),
7777 diag::note_defaulted_comparison_not_rewritten_callee)
7778 << FD;
7779 }
7780 return Result::deleted();
7781 }
7782
7783 // Throughout C++2a [class.compare]: if overload resolution does not
7784 // result in a usable function, the candidate function is defined as
7785 // deleted. This requires that we selected an accessible function.
7786 //
7787 // Note that this only considers the access of the function when named
7788 // within the type of the subobject, and not the access path for any
7789 // derived-to-base conversion.
7790 CXXRecordDecl *ArgClass = Args[0]->getType()->getAsCXXRecordDecl();
7791 if (ArgClass && Best->FoundDecl.getDecl() &&
7792 Best->FoundDecl.getDecl()->isCXXClassMember()) {
7793 QualType ObjectType = Subobj.Kind == Subobject::Member
7794 ? Args[0]->getType()
7795 : S.Context.getRecordType(RD);
7796 if (!S.isMemberAccessibleForDeletion(
7797 ArgClass, Best->FoundDecl, ObjectType, Subobj.Loc,
7798 Diagnose == ExplainDeleted
7799 ? S.PDiag(diag::note_defaulted_comparison_inaccessible)
7800 << FD << Subobj.Kind << Subobj.Decl
7801 : S.PDiag()))
7802 return Result::deleted();
7803 }
7804
7805 // C++2a [class.compare.default]p3 [P2002R0]:
7806 // A defaulted comparison function is constexpr-compatible if [...]
7807 // no overlod resolution performed [...] results in a non-constexpr
7808 // function.
7809 if (FunctionDecl *BestFD = Best->Function) {
7810 assert(!BestFD->isDeleted() && "wrong overload resolution result");
7811 // If it's not constexpr, explain why not.
7812 if (Diagnose == ExplainConstexpr && !BestFD->isConstexpr()) {
7813 if (Subobj.Kind != Subobject::CompleteObject)
7814 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_not_constexpr)
7815 << Subobj.Kind << Subobj.Decl;
7816 S.Diag(BestFD->getLocation(),
7817 diag::note_defaulted_comparison_not_constexpr_here);
7818 // Bail out after explaining; we don't want any more notes.
7819 return Result::deleted();
7820 }
7821 R.Constexpr &= BestFD->isConstexpr();
7822 }
7823
7824 if (OO == OO_Spaceship && FD->getReturnType()->isUndeducedAutoType()) {
7825 if (auto *BestFD = Best->Function) {
7826 // If any callee has an undeduced return type, deduce it now.
7827 // FIXME: It's not clear how a failure here should be handled. For
7828 // now, we produce an eager diagnostic, because that is forward
7829 // compatible with most (all?) other reasonable options.
7830 if (BestFD->getReturnType()->isUndeducedType() &&
7831 S.DeduceReturnType(BestFD, FD->getLocation(),
7832 /*Diagnose=*/false)) {
7833 // Don't produce a duplicate error when asked to explain why the
7834 // comparison is deleted: we diagnosed that when initially checking
7835 // the defaulted operator.
7836 if (Diagnose == NoDiagnostics) {
7837 S.Diag(
7838 FD->getLocation(),
7839 diag::err_defaulted_comparison_cannot_deduce_undeduced_auto)
7840 << Subobj.Kind << Subobj.Decl;
7841 S.Diag(
7842 Subobj.Loc,
7843 diag::note_defaulted_comparison_cannot_deduce_undeduced_auto)
7844 << Subobj.Kind << Subobj.Decl;
7845 S.Diag(BestFD->getLocation(),
7846 diag::note_defaulted_comparison_cannot_deduce_callee)
7847 << Subobj.Kind << Subobj.Decl;
7848 }
7849 return Result::deleted();
7850 }
7851 if (auto *Info = S.Context.CompCategories.lookupInfoForType(
7852 BestFD->getCallResultType())) {
7853 R.Category = Info->Kind;
7854 } else {
7855 if (Diagnose == ExplainDeleted) {
7856 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_cannot_deduce)
7857 << Subobj.Kind << Subobj.Decl
7858 << BestFD->getCallResultType().withoutLocalFastQualifiers();
7859 S.Diag(BestFD->getLocation(),
7860 diag::note_defaulted_comparison_cannot_deduce_callee)
7861 << Subobj.Kind << Subobj.Decl;
7862 }
7863 return Result::deleted();
7864 }
7865 } else {
7866 Optional<ComparisonCategoryType> Cat =
7867 getComparisonCategoryForBuiltinCmp(Args[0]->getType());
7868 assert(Cat && "no category for builtin comparison?");
7869 R.Category = *Cat;
7870 }
7871 }
7872
7873 // Note that we might be rewriting to a different operator. That call is
7874 // not considered until we come to actually build the comparison function.
7875 break;
7876 }
7877
7878 case OR_Ambiguous:
7879 if (Diagnose == ExplainDeleted) {
7880 unsigned Kind = 0;
7881 if (FD->getOverloadedOperator() == OO_Spaceship && OO != OO_Spaceship)
7882 Kind = OO == OO_EqualEqual ? 1 : 2;
7883 CandidateSet.NoteCandidates(
7884 PartialDiagnosticAt(
7885 Subobj.Loc, S.PDiag(diag::note_defaulted_comparison_ambiguous)
7886 << FD << Kind << Subobj.Kind << Subobj.Decl),
7887 S, OCD_AmbiguousCandidates, Args);
7888 }
7889 R = Result::deleted();
7890 break;
7891
7892 case OR_Deleted:
7893 if (Diagnose == ExplainDeleted) {
7894 if ((DCK == DefaultedComparisonKind::NotEqual ||
7895 DCK == DefaultedComparisonKind::Relational) &&
7896 !Best->RewriteKind) {
7897 S.Diag(Best->Function->getLocation(),
7898 diag::note_defaulted_comparison_not_rewritten_callee)
7899 << FD;
7900 } else {
7901 S.Diag(Subobj.Loc,
7902 diag::note_defaulted_comparison_calls_deleted)
7903 << FD << Subobj.Kind << Subobj.Decl;
7904 S.NoteDeletedFunction(Best->Function);
7905 }
7906 }
7907 R = Result::deleted();
7908 break;
7909
7910 case OR_No_Viable_Function:
7911 // If there's no usable candidate, we're done unless we can rewrite a
7912 // '<=>' in terms of '==' and '<'.
7913 if (OO == OO_Spaceship &&
7914 S.Context.CompCategories.lookupInfoForType(FD->getReturnType())) {
7915 // For any kind of comparison category return type, we need a usable
7916 // '==' and a usable '<'.
7917 if (!R.add(visitBinaryOperator(OO_EqualEqual, Args, Subobj,
7918 &CandidateSet)))
7919 R.add(visitBinaryOperator(OO_Less, Args, Subobj, &CandidateSet));
7920 break;
7921 }
7922
7923 if (Diagnose == ExplainDeleted) {
7924 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function)
7925 << FD << Subobj.Kind << Subobj.Decl;
7926
7927 // For a three-way comparison, list both the candidates for the
7928 // original operator and the candidates for the synthesized operator.
7929 if (SpaceshipCandidates) {
7930 SpaceshipCandidates->NoteCandidates(
7931 S, Args,
7932 SpaceshipCandidates->CompleteCandidates(S, OCD_AllCandidates,
7933 Args, FD->getLocation()));
7934 S.Diag(Subobj.Loc,
7935 diag::note_defaulted_comparison_no_viable_function_synthesized)
7936 << (OO == OO_EqualEqual ? 0 : 1);
7937 }
7938
7939 CandidateSet.NoteCandidates(
7940 S, Args,
7941 CandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args,
7942 FD->getLocation()));
7943 }
7944 R = Result::deleted();
7945 break;
7946 }
7947
7948 return R;
7949 }
7950 };
7951
7952 /// A list of statements.
7953 struct StmtListResult {
7954 bool IsInvalid = false;
7955 llvm::SmallVector<Stmt*, 16> Stmts;
7956
add__anonb2a824811f11::StmtListResult7957 bool add(const StmtResult &S) {
7958 IsInvalid |= S.isInvalid();
7959 if (IsInvalid)
7960 return true;
7961 Stmts.push_back(S.get());
7962 return false;
7963 }
7964 };
7965
7966 /// A visitor over the notional body of a defaulted comparison that synthesizes
7967 /// the actual body.
7968 class DefaultedComparisonSynthesizer
7969 : public DefaultedComparisonVisitor<DefaultedComparisonSynthesizer,
7970 StmtListResult, StmtResult,
7971 std::pair<ExprResult, ExprResult>> {
7972 SourceLocation Loc;
7973 unsigned ArrayDepth = 0;
7974
7975 public:
7976 using Base = DefaultedComparisonVisitor;
7977 using ExprPair = std::pair<ExprResult, ExprResult>;
7978
7979 friend Base;
7980
DefaultedComparisonSynthesizer(Sema & S,CXXRecordDecl * RD,FunctionDecl * FD,DefaultedComparisonKind DCK,SourceLocation BodyLoc)7981 DefaultedComparisonSynthesizer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7982 DefaultedComparisonKind DCK,
7983 SourceLocation BodyLoc)
7984 : Base(S, RD, FD, DCK), Loc(BodyLoc) {}
7985
7986 /// Build a suitable function body for this defaulted comparison operator.
build()7987 StmtResult build() {
7988 Sema::CompoundScopeRAII CompoundScope(S);
7989
7990 StmtListResult Stmts = visit();
7991 if (Stmts.IsInvalid)
7992 return StmtError();
7993
7994 ExprResult RetVal;
7995 switch (DCK) {
7996 case DefaultedComparisonKind::None:
7997 llvm_unreachable("not a defaulted comparison");
7998
7999 case DefaultedComparisonKind::Equal: {
8000 // C++2a [class.eq]p3:
8001 // [...] compar[e] the corresponding elements [...] until the first
8002 // index i where xi == yi yields [...] false. If no such index exists,
8003 // V is true. Otherwise, V is false.
8004 //
8005 // Join the comparisons with '&&'s and return the result. Use a right
8006 // fold (traversing the conditions right-to-left), because that
8007 // short-circuits more naturally.
8008 auto OldStmts = std::move(Stmts.Stmts);
8009 Stmts.Stmts.clear();
8010 ExprResult CmpSoFar;
8011 // Finish a particular comparison chain.
8012 auto FinishCmp = [&] {
8013 if (Expr *Prior = CmpSoFar.get()) {
8014 // Convert the last expression to 'return ...;'
8015 if (RetVal.isUnset() && Stmts.Stmts.empty())
8016 RetVal = CmpSoFar;
8017 // Convert any prior comparison to 'if (!(...)) return false;'
8018 else if (Stmts.add(buildIfNotCondReturnFalse(Prior)))
8019 return true;
8020 CmpSoFar = ExprResult();
8021 }
8022 return false;
8023 };
8024 for (Stmt *EAsStmt : llvm::reverse(OldStmts)) {
8025 Expr *E = dyn_cast<Expr>(EAsStmt);
8026 if (!E) {
8027 // Found an array comparison.
8028 if (FinishCmp() || Stmts.add(EAsStmt))
8029 return StmtError();
8030 continue;
8031 }
8032
8033 if (CmpSoFar.isUnset()) {
8034 CmpSoFar = E;
8035 continue;
8036 }
8037 CmpSoFar = S.CreateBuiltinBinOp(Loc, BO_LAnd, E, CmpSoFar.get());
8038 if (CmpSoFar.isInvalid())
8039 return StmtError();
8040 }
8041 if (FinishCmp())
8042 return StmtError();
8043 std::reverse(Stmts.Stmts.begin(), Stmts.Stmts.end());
8044 // If no such index exists, V is true.
8045 if (RetVal.isUnset())
8046 RetVal = S.ActOnCXXBoolLiteral(Loc, tok::kw_true);
8047 break;
8048 }
8049
8050 case DefaultedComparisonKind::ThreeWay: {
8051 // Per C++2a [class.spaceship]p3, as a fallback add:
8052 // return static_cast<R>(std::strong_ordering::equal);
8053 QualType StrongOrdering = S.CheckComparisonCategoryType(
8054 ComparisonCategoryType::StrongOrdering, Loc,
8055 Sema::ComparisonCategoryUsage::DefaultedOperator);
8056 if (StrongOrdering.isNull())
8057 return StmtError();
8058 VarDecl *EqualVD = S.Context.CompCategories.getInfoForType(StrongOrdering)
8059 .getValueInfo(ComparisonCategoryResult::Equal)
8060 ->VD;
8061 RetVal = getDecl(EqualVD);
8062 if (RetVal.isInvalid())
8063 return StmtError();
8064 RetVal = buildStaticCastToR(RetVal.get());
8065 break;
8066 }
8067
8068 case DefaultedComparisonKind::NotEqual:
8069 case DefaultedComparisonKind::Relational:
8070 RetVal = cast<Expr>(Stmts.Stmts.pop_back_val());
8071 break;
8072 }
8073
8074 // Build the final return statement.
8075 if (RetVal.isInvalid())
8076 return StmtError();
8077 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, RetVal.get());
8078 if (ReturnStmt.isInvalid())
8079 return StmtError();
8080 Stmts.Stmts.push_back(ReturnStmt.get());
8081
8082 return S.ActOnCompoundStmt(Loc, Loc, Stmts.Stmts, /*IsStmtExpr=*/false);
8083 }
8084
8085 private:
getDecl(ValueDecl * VD)8086 ExprResult getDecl(ValueDecl *VD) {
8087 return S.BuildDeclarationNameExpr(
8088 CXXScopeSpec(), DeclarationNameInfo(VD->getDeclName(), Loc), VD);
8089 }
8090
getParam(unsigned I)8091 ExprResult getParam(unsigned I) {
8092 ParmVarDecl *PD = FD->getParamDecl(I);
8093 return getDecl(PD);
8094 }
8095
getCompleteObject()8096 ExprPair getCompleteObject() {
8097 unsigned Param = 0;
8098 ExprResult LHS;
8099 if (isa<CXXMethodDecl>(FD)) {
8100 // LHS is '*this'.
8101 LHS = S.ActOnCXXThis(Loc);
8102 if (!LHS.isInvalid())
8103 LHS = S.CreateBuiltinUnaryOp(Loc, UO_Deref, LHS.get());
8104 } else {
8105 LHS = getParam(Param++);
8106 }
8107 ExprResult RHS = getParam(Param++);
8108 assert(Param == FD->getNumParams());
8109 return {LHS, RHS};
8110 }
8111
getBase(CXXBaseSpecifier * Base)8112 ExprPair getBase(CXXBaseSpecifier *Base) {
8113 ExprPair Obj = getCompleteObject();
8114 if (Obj.first.isInvalid() || Obj.second.isInvalid())
8115 return {ExprError(), ExprError()};
8116 CXXCastPath Path = {Base};
8117 return {S.ImpCastExprToType(Obj.first.get(), Base->getType(),
8118 CK_DerivedToBase, VK_LValue, &Path),
8119 S.ImpCastExprToType(Obj.second.get(), Base->getType(),
8120 CK_DerivedToBase, VK_LValue, &Path)};
8121 }
8122
getField(FieldDecl * Field)8123 ExprPair getField(FieldDecl *Field) {
8124 ExprPair Obj = getCompleteObject();
8125 if (Obj.first.isInvalid() || Obj.second.isInvalid())
8126 return {ExprError(), ExprError()};
8127
8128 DeclAccessPair Found = DeclAccessPair::make(Field, Field->getAccess());
8129 DeclarationNameInfo NameInfo(Field->getDeclName(), Loc);
8130 return {S.BuildFieldReferenceExpr(Obj.first.get(), /*IsArrow=*/false, Loc,
8131 CXXScopeSpec(), Field, Found, NameInfo),
8132 S.BuildFieldReferenceExpr(Obj.second.get(), /*IsArrow=*/false, Loc,
8133 CXXScopeSpec(), Field, Found, NameInfo)};
8134 }
8135
8136 // FIXME: When expanding a subobject, register a note in the code synthesis
8137 // stack to say which subobject we're comparing.
8138
buildIfNotCondReturnFalse(ExprResult Cond)8139 StmtResult buildIfNotCondReturnFalse(ExprResult Cond) {
8140 if (Cond.isInvalid())
8141 return StmtError();
8142
8143 ExprResult NotCond = S.CreateBuiltinUnaryOp(Loc, UO_LNot, Cond.get());
8144 if (NotCond.isInvalid())
8145 return StmtError();
8146
8147 ExprResult False = S.ActOnCXXBoolLiteral(Loc, tok::kw_false);
8148 assert(!False.isInvalid() && "should never fail");
8149 StmtResult ReturnFalse = S.BuildReturnStmt(Loc, False.get());
8150 if (ReturnFalse.isInvalid())
8151 return StmtError();
8152
8153 return S.ActOnIfStmt(Loc, false, Loc, nullptr,
8154 S.ActOnCondition(nullptr, Loc, NotCond.get(),
8155 Sema::ConditionKind::Boolean),
8156 Loc, ReturnFalse.get(), SourceLocation(), nullptr);
8157 }
8158
visitSubobjectArray(QualType Type,llvm::APInt Size,ExprPair Subobj)8159 StmtResult visitSubobjectArray(QualType Type, llvm::APInt Size,
8160 ExprPair Subobj) {
8161 QualType SizeType = S.Context.getSizeType();
8162 Size = Size.zextOrTrunc(S.Context.getTypeSize(SizeType));
8163
8164 // Build 'size_t i$n = 0'.
8165 IdentifierInfo *IterationVarName = nullptr;
8166 {
8167 SmallString<8> Str;
8168 llvm::raw_svector_ostream OS(Str);
8169 OS << "i" << ArrayDepth;
8170 IterationVarName = &S.Context.Idents.get(OS.str());
8171 }
8172 VarDecl *IterationVar = VarDecl::Create(
8173 S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType,
8174 S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None);
8175 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
8176 IterationVar->setInit(
8177 IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
8178 Stmt *Init = new (S.Context) DeclStmt(DeclGroupRef(IterationVar), Loc, Loc);
8179
8180 auto IterRef = [&] {
8181 ExprResult Ref = S.BuildDeclarationNameExpr(
8182 CXXScopeSpec(), DeclarationNameInfo(IterationVarName, Loc),
8183 IterationVar);
8184 assert(!Ref.isInvalid() && "can't reference our own variable?");
8185 return Ref.get();
8186 };
8187
8188 // Build 'i$n != Size'.
8189 ExprResult Cond = S.CreateBuiltinBinOp(
8190 Loc, BO_NE, IterRef(),
8191 IntegerLiteral::Create(S.Context, Size, SizeType, Loc));
8192 assert(!Cond.isInvalid() && "should never fail");
8193
8194 // Build '++i$n'.
8195 ExprResult Inc = S.CreateBuiltinUnaryOp(Loc, UO_PreInc, IterRef());
8196 assert(!Inc.isInvalid() && "should never fail");
8197
8198 // Build 'a[i$n]' and 'b[i$n]'.
8199 auto Index = [&](ExprResult E) {
8200 if (E.isInvalid())
8201 return ExprError();
8202 return S.CreateBuiltinArraySubscriptExpr(E.get(), Loc, IterRef(), Loc);
8203 };
8204 Subobj.first = Index(Subobj.first);
8205 Subobj.second = Index(Subobj.second);
8206
8207 // Compare the array elements.
8208 ++ArrayDepth;
8209 StmtResult Substmt = visitSubobject(Type, Subobj);
8210 --ArrayDepth;
8211
8212 if (Substmt.isInvalid())
8213 return StmtError();
8214
8215 // For the inner level of an 'operator==', build 'if (!cmp) return false;'.
8216 // For outer levels or for an 'operator<=>' we already have a suitable
8217 // statement that returns as necessary.
8218 if (Expr *ElemCmp = dyn_cast<Expr>(Substmt.get())) {
8219 assert(DCK == DefaultedComparisonKind::Equal &&
8220 "should have non-expression statement");
8221 Substmt = buildIfNotCondReturnFalse(ElemCmp);
8222 if (Substmt.isInvalid())
8223 return StmtError();
8224 }
8225
8226 // Build 'for (...) ...'
8227 return S.ActOnForStmt(Loc, Loc, Init,
8228 S.ActOnCondition(nullptr, Loc, Cond.get(),
8229 Sema::ConditionKind::Boolean),
8230 S.MakeFullDiscardedValueExpr(Inc.get()), Loc,
8231 Substmt.get());
8232 }
8233
visitExpandedSubobject(QualType Type,ExprPair Obj)8234 StmtResult visitExpandedSubobject(QualType Type, ExprPair Obj) {
8235 if (Obj.first.isInvalid() || Obj.second.isInvalid())
8236 return StmtError();
8237
8238 OverloadedOperatorKind OO = FD->getOverloadedOperator();
8239 BinaryOperatorKind Opc = BinaryOperator::getOverloadedOpcode(OO);
8240 ExprResult Op;
8241 if (Type->isOverloadableType())
8242 Op = S.CreateOverloadedBinOp(Loc, Opc, Fns, Obj.first.get(),
8243 Obj.second.get(), /*PerformADL=*/true,
8244 /*AllowRewrittenCandidates=*/true, FD);
8245 else
8246 Op = S.CreateBuiltinBinOp(Loc, Opc, Obj.first.get(), Obj.second.get());
8247 if (Op.isInvalid())
8248 return StmtError();
8249
8250 switch (DCK) {
8251 case DefaultedComparisonKind::None:
8252 llvm_unreachable("not a defaulted comparison");
8253
8254 case DefaultedComparisonKind::Equal:
8255 // Per C++2a [class.eq]p2, each comparison is individually contextually
8256 // converted to bool.
8257 Op = S.PerformContextuallyConvertToBool(Op.get());
8258 if (Op.isInvalid())
8259 return StmtError();
8260 return Op.get();
8261
8262 case DefaultedComparisonKind::ThreeWay: {
8263 // Per C++2a [class.spaceship]p3, form:
8264 // if (R cmp = static_cast<R>(op); cmp != 0)
8265 // return cmp;
8266 QualType R = FD->getReturnType();
8267 Op = buildStaticCastToR(Op.get());
8268 if (Op.isInvalid())
8269 return StmtError();
8270
8271 // R cmp = ...;
8272 IdentifierInfo *Name = &S.Context.Idents.get("cmp");
8273 VarDecl *VD =
8274 VarDecl::Create(S.Context, S.CurContext, Loc, Loc, Name, R,
8275 S.Context.getTrivialTypeSourceInfo(R, Loc), SC_None);
8276 S.AddInitializerToDecl(VD, Op.get(), /*DirectInit=*/false);
8277 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(VD), Loc, Loc);
8278
8279 // cmp != 0
8280 ExprResult VDRef = getDecl(VD);
8281 if (VDRef.isInvalid())
8282 return StmtError();
8283 llvm::APInt ZeroVal(S.Context.getIntWidth(S.Context.IntTy), 0);
8284 Expr *Zero =
8285 IntegerLiteral::Create(S.Context, ZeroVal, S.Context.IntTy, Loc);
8286 ExprResult Comp;
8287 if (VDRef.get()->getType()->isOverloadableType())
8288 Comp = S.CreateOverloadedBinOp(Loc, BO_NE, Fns, VDRef.get(), Zero, true,
8289 true, FD);
8290 else
8291 Comp = S.CreateBuiltinBinOp(Loc, BO_NE, VDRef.get(), Zero);
8292 if (Comp.isInvalid())
8293 return StmtError();
8294 Sema::ConditionResult Cond = S.ActOnCondition(
8295 nullptr, Loc, Comp.get(), Sema::ConditionKind::Boolean);
8296 if (Cond.isInvalid())
8297 return StmtError();
8298
8299 // return cmp;
8300 VDRef = getDecl(VD);
8301 if (VDRef.isInvalid())
8302 return StmtError();
8303 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, VDRef.get());
8304 if (ReturnStmt.isInvalid())
8305 return StmtError();
8306
8307 // if (...)
8308 return S.ActOnIfStmt(Loc, /*IsConstexpr=*/false, Loc, InitStmt, Cond, Loc,
8309 ReturnStmt.get(),
8310 /*ElseLoc=*/SourceLocation(), /*Else=*/nullptr);
8311 }
8312
8313 case DefaultedComparisonKind::NotEqual:
8314 case DefaultedComparisonKind::Relational:
8315 // C++2a [class.compare.secondary]p2:
8316 // Otherwise, the operator function yields x @ y.
8317 return Op.get();
8318 }
8319 llvm_unreachable("");
8320 }
8321
8322 /// Build "static_cast<R>(E)".
buildStaticCastToR(Expr * E)8323 ExprResult buildStaticCastToR(Expr *E) {
8324 QualType R = FD->getReturnType();
8325 assert(!R->isUndeducedType() && "type should have been deduced already");
8326
8327 // Don't bother forming a no-op cast in the common case.
8328 if (E->isRValue() && S.Context.hasSameType(E->getType(), R))
8329 return E;
8330 return S.BuildCXXNamedCast(Loc, tok::kw_static_cast,
8331 S.Context.getTrivialTypeSourceInfo(R, Loc), E,
8332 SourceRange(Loc, Loc), SourceRange(Loc, Loc));
8333 }
8334 };
8335 }
8336
8337 /// Perform the unqualified lookups that might be needed to form a defaulted
8338 /// comparison function for the given operator.
lookupOperatorsForDefaultedComparison(Sema & Self,Scope * S,UnresolvedSetImpl & Operators,OverloadedOperatorKind Op)8339 static void lookupOperatorsForDefaultedComparison(Sema &Self, Scope *S,
8340 UnresolvedSetImpl &Operators,
8341 OverloadedOperatorKind Op) {
8342 auto Lookup = [&](OverloadedOperatorKind OO) {
8343 Self.LookupOverloadedOperatorName(OO, S, Operators);
8344 };
8345
8346 // Every defaulted operator looks up itself.
8347 Lookup(Op);
8348 // ... and the rewritten form of itself, if any.
8349 if (OverloadedOperatorKind ExtraOp = getRewrittenOverloadedOperator(Op))
8350 Lookup(ExtraOp);
8351
8352 // For 'operator<=>', we also form a 'cmp != 0' expression, and might
8353 // synthesize a three-way comparison from '<' and '=='. In a dependent
8354 // context, we also need to look up '==' in case we implicitly declare a
8355 // defaulted 'operator=='.
8356 if (Op == OO_Spaceship) {
8357 Lookup(OO_ExclaimEqual);
8358 Lookup(OO_Less);
8359 Lookup(OO_EqualEqual);
8360 }
8361 }
8362
CheckExplicitlyDefaultedComparison(Scope * S,FunctionDecl * FD,DefaultedComparisonKind DCK)8363 bool Sema::CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *FD,
8364 DefaultedComparisonKind DCK) {
8365 assert(DCK != DefaultedComparisonKind::None && "not a defaulted comparison");
8366
8367 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(FD->getLexicalDeclContext());
8368 assert(RD && "defaulted comparison is not defaulted in a class");
8369
8370 // Perform any unqualified lookups we're going to need to default this
8371 // function.
8372 if (S) {
8373 UnresolvedSet<32> Operators;
8374 lookupOperatorsForDefaultedComparison(*this, S, Operators,
8375 FD->getOverloadedOperator());
8376 FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create(
8377 Context, Operators.pairs()));
8378 }
8379
8380 // C++2a [class.compare.default]p1:
8381 // A defaulted comparison operator function for some class C shall be a
8382 // non-template function declared in the member-specification of C that is
8383 // -- a non-static const member of C having one parameter of type
8384 // const C&, or
8385 // -- a friend of C having two parameters of type const C& or two
8386 // parameters of type C.
8387 QualType ExpectedParmType1 = Context.getRecordType(RD);
8388 QualType ExpectedParmType2 =
8389 Context.getLValueReferenceType(ExpectedParmType1.withConst());
8390 if (isa<CXXMethodDecl>(FD))
8391 ExpectedParmType1 = ExpectedParmType2;
8392 for (const ParmVarDecl *Param : FD->parameters()) {
8393 if (!Param->getType()->isDependentType() &&
8394 !Context.hasSameType(Param->getType(), ExpectedParmType1) &&
8395 !Context.hasSameType(Param->getType(), ExpectedParmType2)) {
8396 // Don't diagnose an implicit 'operator=='; we will have diagnosed the
8397 // corresponding defaulted 'operator<=>' already.
8398 if (!FD->isImplicit()) {
8399 Diag(FD->getLocation(), diag::err_defaulted_comparison_param)
8400 << (int)DCK << Param->getType() << ExpectedParmType1
8401 << !isa<CXXMethodDecl>(FD)
8402 << ExpectedParmType2 << Param->getSourceRange();
8403 }
8404 return true;
8405 }
8406 }
8407 if (FD->getNumParams() == 2 &&
8408 !Context.hasSameType(FD->getParamDecl(0)->getType(),
8409 FD->getParamDecl(1)->getType())) {
8410 if (!FD->isImplicit()) {
8411 Diag(FD->getLocation(), diag::err_defaulted_comparison_param_mismatch)
8412 << (int)DCK
8413 << FD->getParamDecl(0)->getType()
8414 << FD->getParamDecl(0)->getSourceRange()
8415 << FD->getParamDecl(1)->getType()
8416 << FD->getParamDecl(1)->getSourceRange();
8417 }
8418 return true;
8419 }
8420
8421 // ... non-static const member ...
8422 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
8423 assert(!MD->isStatic() && "comparison function cannot be a static member");
8424 if (!MD->isConst()) {
8425 SourceLocation InsertLoc;
8426 if (FunctionTypeLoc Loc = MD->getFunctionTypeLoc())
8427 InsertLoc = getLocForEndOfToken(Loc.getRParenLoc());
8428 // Don't diagnose an implicit 'operator=='; we will have diagnosed the
8429 // corresponding defaulted 'operator<=>' already.
8430 if (!MD->isImplicit()) {
8431 Diag(MD->getLocation(), diag::err_defaulted_comparison_non_const)
8432 << (int)DCK << FixItHint::CreateInsertion(InsertLoc, " const");
8433 }
8434
8435 // Add the 'const' to the type to recover.
8436 const auto *FPT = MD->getType()->castAs<FunctionProtoType>();
8437 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
8438 EPI.TypeQuals.addConst();
8439 MD->setType(Context.getFunctionType(FPT->getReturnType(),
8440 FPT->getParamTypes(), EPI));
8441 }
8442 } else {
8443 // A non-member function declared in a class must be a friend.
8444 assert(FD->getFriendObjectKind() && "expected a friend declaration");
8445 }
8446
8447 // C++2a [class.eq]p1, [class.rel]p1:
8448 // A [defaulted comparison other than <=>] shall have a declared return
8449 // type bool.
8450 if (DCK != DefaultedComparisonKind::ThreeWay &&
8451 !FD->getDeclaredReturnType()->isDependentType() &&
8452 !Context.hasSameType(FD->getDeclaredReturnType(), Context.BoolTy)) {
8453 Diag(FD->getLocation(), diag::err_defaulted_comparison_return_type_not_bool)
8454 << (int)DCK << FD->getDeclaredReturnType() << Context.BoolTy
8455 << FD->getReturnTypeSourceRange();
8456 return true;
8457 }
8458 // C++2a [class.spaceship]p2 [P2002R0]:
8459 // Let R be the declared return type [...]. If R is auto, [...]. Otherwise,
8460 // R shall not contain a placeholder type.
8461 if (DCK == DefaultedComparisonKind::ThreeWay &&
8462 FD->getDeclaredReturnType()->getContainedDeducedType() &&
8463 !Context.hasSameType(FD->getDeclaredReturnType(),
8464 Context.getAutoDeductType())) {
8465 Diag(FD->getLocation(),
8466 diag::err_defaulted_comparison_deduced_return_type_not_auto)
8467 << (int)DCK << FD->getDeclaredReturnType() << Context.AutoDeductTy
8468 << FD->getReturnTypeSourceRange();
8469 return true;
8470 }
8471
8472 // For a defaulted function in a dependent class, defer all remaining checks
8473 // until instantiation.
8474 if (RD->isDependentType())
8475 return false;
8476
8477 // Determine whether the function should be defined as deleted.
8478 DefaultedComparisonInfo Info =
8479 DefaultedComparisonAnalyzer(*this, RD, FD, DCK).visit();
8480
8481 bool First = FD == FD->getCanonicalDecl();
8482
8483 // If we want to delete the function, then do so; there's nothing else to
8484 // check in that case.
8485 if (Info.Deleted) {
8486 if (!First) {
8487 // C++11 [dcl.fct.def.default]p4:
8488 // [For a] user-provided explicitly-defaulted function [...] if such a
8489 // function is implicitly defined as deleted, the program is ill-formed.
8490 //
8491 // This is really just a consequence of the general rule that you can
8492 // only delete a function on its first declaration.
8493 Diag(FD->getLocation(), diag::err_non_first_default_compare_deletes)
8494 << FD->isImplicit() << (int)DCK;
8495 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8496 DefaultedComparisonAnalyzer::ExplainDeleted)
8497 .visit();
8498 return true;
8499 }
8500
8501 SetDeclDeleted(FD, FD->getLocation());
8502 if (!inTemplateInstantiation() && !FD->isImplicit()) {
8503 Diag(FD->getLocation(), diag::warn_defaulted_comparison_deleted)
8504 << (int)DCK;
8505 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8506 DefaultedComparisonAnalyzer::ExplainDeleted)
8507 .visit();
8508 }
8509 return false;
8510 }
8511
8512 // C++2a [class.spaceship]p2:
8513 // The return type is deduced as the common comparison type of R0, R1, ...
8514 if (DCK == DefaultedComparisonKind::ThreeWay &&
8515 FD->getDeclaredReturnType()->isUndeducedAutoType()) {
8516 SourceLocation RetLoc = FD->getReturnTypeSourceRange().getBegin();
8517 if (RetLoc.isInvalid())
8518 RetLoc = FD->getBeginLoc();
8519 // FIXME: Should we really care whether we have the complete type and the
8520 // 'enumerator' constants here? A forward declaration seems sufficient.
8521 QualType Cat = CheckComparisonCategoryType(
8522 Info.Category, RetLoc, ComparisonCategoryUsage::DefaultedOperator);
8523 if (Cat.isNull())
8524 return true;
8525 Context.adjustDeducedFunctionResultType(
8526 FD, SubstAutoType(FD->getDeclaredReturnType(), Cat));
8527 }
8528
8529 // C++2a [dcl.fct.def.default]p3 [P2002R0]:
8530 // An explicitly-defaulted function that is not defined as deleted may be
8531 // declared constexpr or consteval only if it is constexpr-compatible.
8532 // C++2a [class.compare.default]p3 [P2002R0]:
8533 // A defaulted comparison function is constexpr-compatible if it satisfies
8534 // the requirements for a constexpr function [...]
8535 // The only relevant requirements are that the parameter and return types are
8536 // literal types. The remaining conditions are checked by the analyzer.
8537 if (FD->isConstexpr()) {
8538 if (CheckConstexprReturnType(*this, FD, CheckConstexprKind::Diagnose) &&
8539 CheckConstexprParameterTypes(*this, FD, CheckConstexprKind::Diagnose) &&
8540 !Info.Constexpr) {
8541 Diag(FD->getBeginLoc(),
8542 diag::err_incorrect_defaulted_comparison_constexpr)
8543 << FD->isImplicit() << (int)DCK << FD->isConsteval();
8544 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8545 DefaultedComparisonAnalyzer::ExplainConstexpr)
8546 .visit();
8547 }
8548 }
8549
8550 // C++2a [dcl.fct.def.default]p3 [P2002R0]:
8551 // If a constexpr-compatible function is explicitly defaulted on its first
8552 // declaration, it is implicitly considered to be constexpr.
8553 // FIXME: Only applying this to the first declaration seems problematic, as
8554 // simple reorderings can affect the meaning of the program.
8555 if (First && !FD->isConstexpr() && Info.Constexpr)
8556 FD->setConstexprKind(ConstexprSpecKind::Constexpr);
8557
8558 // C++2a [except.spec]p3:
8559 // If a declaration of a function does not have a noexcept-specifier
8560 // [and] is defaulted on its first declaration, [...] the exception
8561 // specification is as specified below
8562 if (FD->getExceptionSpecType() == EST_None) {
8563 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
8564 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
8565 EPI.ExceptionSpec.Type = EST_Unevaluated;
8566 EPI.ExceptionSpec.SourceDecl = FD;
8567 FD->setType(Context.getFunctionType(FPT->getReturnType(),
8568 FPT->getParamTypes(), EPI));
8569 }
8570
8571 return false;
8572 }
8573
DeclareImplicitEqualityComparison(CXXRecordDecl * RD,FunctionDecl * Spaceship)8574 void Sema::DeclareImplicitEqualityComparison(CXXRecordDecl *RD,
8575 FunctionDecl *Spaceship) {
8576 Sema::CodeSynthesisContext Ctx;
8577 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringImplicitEqualityComparison;
8578 Ctx.PointOfInstantiation = Spaceship->getEndLoc();
8579 Ctx.Entity = Spaceship;
8580 pushCodeSynthesisContext(Ctx);
8581
8582 if (FunctionDecl *EqualEqual = SubstSpaceshipAsEqualEqual(RD, Spaceship))
8583 EqualEqual->setImplicit();
8584
8585 popCodeSynthesisContext();
8586 }
8587
DefineDefaultedComparison(SourceLocation UseLoc,FunctionDecl * FD,DefaultedComparisonKind DCK)8588 void Sema::DefineDefaultedComparison(SourceLocation UseLoc, FunctionDecl *FD,
8589 DefaultedComparisonKind DCK) {
8590 assert(FD->isDefaulted() && !FD->isDeleted() &&
8591 !FD->doesThisDeclarationHaveABody());
8592 if (FD->willHaveBody() || FD->isInvalidDecl())
8593 return;
8594
8595 SynthesizedFunctionScope Scope(*this, FD);
8596
8597 // Add a context note for diagnostics produced after this point.
8598 Scope.addContextNote(UseLoc);
8599
8600 {
8601 // Build and set up the function body.
8602 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
8603 SourceLocation BodyLoc =
8604 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
8605 StmtResult Body =
8606 DefaultedComparisonSynthesizer(*this, RD, FD, DCK, BodyLoc).build();
8607 if (Body.isInvalid()) {
8608 FD->setInvalidDecl();
8609 return;
8610 }
8611 FD->setBody(Body.get());
8612 FD->markUsed(Context);
8613 }
8614
8615 // The exception specification is needed because we are defining the
8616 // function. Note that this will reuse the body we just built.
8617 ResolveExceptionSpec(UseLoc, FD->getType()->castAs<FunctionProtoType>());
8618
8619 if (ASTMutationListener *L = getASTMutationListener())
8620 L->CompletedImplicitDefinition(FD);
8621 }
8622
8623 static Sema::ImplicitExceptionSpecification
ComputeDefaultedComparisonExceptionSpec(Sema & S,SourceLocation Loc,FunctionDecl * FD,Sema::DefaultedComparisonKind DCK)8624 ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
8625 FunctionDecl *FD,
8626 Sema::DefaultedComparisonKind DCK) {
8627 ComputingExceptionSpec CES(S, FD, Loc);
8628 Sema::ImplicitExceptionSpecification ExceptSpec(S);
8629
8630 if (FD->isInvalidDecl())
8631 return ExceptSpec;
8632
8633 // The common case is that we just defined the comparison function. In that
8634 // case, just look at whether the body can throw.
8635 if (FD->hasBody()) {
8636 ExceptSpec.CalledStmt(FD->getBody());
8637 } else {
8638 // Otherwise, build a body so we can check it. This should ideally only
8639 // happen when we're not actually marking the function referenced. (This is
8640 // only really important for efficiency: we don't want to build and throw
8641 // away bodies for comparison functions more than we strictly need to.)
8642
8643 // Pretend to synthesize the function body in an unevaluated context.
8644 // Note that we can't actually just go ahead and define the function here:
8645 // we are not permitted to mark its callees as referenced.
8646 Sema::SynthesizedFunctionScope Scope(S, FD);
8647 EnterExpressionEvaluationContext Context(
8648 S, Sema::ExpressionEvaluationContext::Unevaluated);
8649
8650 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
8651 SourceLocation BodyLoc =
8652 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
8653 StmtResult Body =
8654 DefaultedComparisonSynthesizer(S, RD, FD, DCK, BodyLoc).build();
8655 if (!Body.isInvalid())
8656 ExceptSpec.CalledStmt(Body.get());
8657
8658 // FIXME: Can we hold onto this body and just transform it to potentially
8659 // evaluated when we're asked to define the function rather than rebuilding
8660 // it? Either that, or we should only build the bits of the body that we
8661 // need (the expressions, not the statements).
8662 }
8663
8664 return ExceptSpec;
8665 }
8666
CheckDelayedMemberExceptionSpecs()8667 void Sema::CheckDelayedMemberExceptionSpecs() {
8668 decltype(DelayedOverridingExceptionSpecChecks) Overriding;
8669 decltype(DelayedEquivalentExceptionSpecChecks) Equivalent;
8670
8671 std::swap(Overriding, DelayedOverridingExceptionSpecChecks);
8672 std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks);
8673
8674 // Perform any deferred checking of exception specifications for virtual
8675 // destructors.
8676 for (auto &Check : Overriding)
8677 CheckOverridingFunctionExceptionSpec(Check.first, Check.second);
8678
8679 // Perform any deferred checking of exception specifications for befriended
8680 // special members.
8681 for (auto &Check : Equivalent)
8682 CheckEquivalentExceptionSpec(Check.second, Check.first);
8683 }
8684
8685 namespace {
8686 /// CRTP base class for visiting operations performed by a special member
8687 /// function (or inherited constructor).
8688 template<typename Derived>
8689 struct SpecialMemberVisitor {
8690 Sema &S;
8691 CXXMethodDecl *MD;
8692 Sema::CXXSpecialMember CSM;
8693 Sema::InheritedConstructorInfo *ICI;
8694
8695 // Properties of the special member, computed for convenience.
8696 bool IsConstructor = false, IsAssignment = false, ConstArg = false;
8697
SpecialMemberVisitor__anonb2a824812511::SpecialMemberVisitor8698 SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
8699 Sema::InheritedConstructorInfo *ICI)
8700 : S(S), MD(MD), CSM(CSM), ICI(ICI) {
8701 switch (CSM) {
8702 case Sema::CXXDefaultConstructor:
8703 case Sema::CXXCopyConstructor:
8704 case Sema::CXXMoveConstructor:
8705 IsConstructor = true;
8706 break;
8707 case Sema::CXXCopyAssignment:
8708 case Sema::CXXMoveAssignment:
8709 IsAssignment = true;
8710 break;
8711 case Sema::CXXDestructor:
8712 break;
8713 case Sema::CXXInvalid:
8714 llvm_unreachable("invalid special member kind");
8715 }
8716
8717 if (MD->getNumParams()) {
8718 if (const ReferenceType *RT =
8719 MD->getParamDecl(0)->getType()->getAs<ReferenceType>())
8720 ConstArg = RT->getPointeeType().isConstQualified();
8721 }
8722 }
8723
getDerived__anonb2a824812511::SpecialMemberVisitor8724 Derived &getDerived() { return static_cast<Derived&>(*this); }
8725
8726 /// Is this a "move" special member?
isMove__anonb2a824812511::SpecialMemberVisitor8727 bool isMove() const {
8728 return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment;
8729 }
8730
8731 /// Look up the corresponding special member in the given class.
lookupIn__anonb2a824812511::SpecialMemberVisitor8732 Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class,
8733 unsigned Quals, bool IsMutable) {
8734 return lookupCallFromSpecialMember(S, Class, CSM, Quals,
8735 ConstArg && !IsMutable);
8736 }
8737
8738 /// Look up the constructor for the specified base class to see if it's
8739 /// overridden due to this being an inherited constructor.
lookupInheritedCtor__anonb2a824812511::SpecialMemberVisitor8740 Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) {
8741 if (!ICI)
8742 return {};
8743 assert(CSM == Sema::CXXDefaultConstructor);
8744 auto *BaseCtor =
8745 cast<CXXConstructorDecl>(MD)->getInheritedConstructor().getConstructor();
8746 if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first)
8747 return MD;
8748 return {};
8749 }
8750
8751 /// A base or member subobject.
8752 typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
8753
8754 /// Get the location to use for a subobject in diagnostics.
getSubobjectLoc__anonb2a824812511::SpecialMemberVisitor8755 static SourceLocation getSubobjectLoc(Subobject Subobj) {
8756 // FIXME: For an indirect virtual base, the direct base leading to
8757 // the indirect virtual base would be a more useful choice.
8758 if (auto *B = Subobj.dyn_cast<CXXBaseSpecifier*>())
8759 return B->getBaseTypeLoc();
8760 else
8761 return Subobj.get<FieldDecl*>()->getLocation();
8762 }
8763
8764 enum BasesToVisit {
8765 /// Visit all non-virtual (direct) bases.
8766 VisitNonVirtualBases,
8767 /// Visit all direct bases, virtual or not.
8768 VisitDirectBases,
8769 /// Visit all non-virtual bases, and all virtual bases if the class
8770 /// is not abstract.
8771 VisitPotentiallyConstructedBases,
8772 /// Visit all direct or virtual bases.
8773 VisitAllBases
8774 };
8775
8776 // Visit the bases and members of the class.
visit__anonb2a824812511::SpecialMemberVisitor8777 bool visit(BasesToVisit Bases) {
8778 CXXRecordDecl *RD = MD->getParent();
8779
8780 if (Bases == VisitPotentiallyConstructedBases)
8781 Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases;
8782
8783 for (auto &B : RD->bases())
8784 if ((Bases == VisitDirectBases || !B.isVirtual()) &&
8785 getDerived().visitBase(&B))
8786 return true;
8787
8788 if (Bases == VisitAllBases)
8789 for (auto &B : RD->vbases())
8790 if (getDerived().visitBase(&B))
8791 return true;
8792
8793 for (auto *F : RD->fields())
8794 if (!F->isInvalidDecl() && !F->isUnnamedBitfield() &&
8795 getDerived().visitField(F))
8796 return true;
8797
8798 return false;
8799 }
8800 };
8801 }
8802
8803 namespace {
8804 struct SpecialMemberDeletionInfo
8805 : SpecialMemberVisitor<SpecialMemberDeletionInfo> {
8806 bool Diagnose;
8807
8808 SourceLocation Loc;
8809
8810 bool AllFieldsAreConst;
8811
SpecialMemberDeletionInfo__anonb2a824812611::SpecialMemberDeletionInfo8812 SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
8813 Sema::CXXSpecialMember CSM,
8814 Sema::InheritedConstructorInfo *ICI, bool Diagnose)
8815 : SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose),
8816 Loc(MD->getLocation()), AllFieldsAreConst(true) {}
8817
inUnion__anonb2a824812611::SpecialMemberDeletionInfo8818 bool inUnion() const { return MD->getParent()->isUnion(); }
8819
getEffectiveCSM__anonb2a824812611::SpecialMemberDeletionInfo8820 Sema::CXXSpecialMember getEffectiveCSM() {
8821 return ICI ? Sema::CXXInvalid : CSM;
8822 }
8823
8824 bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType);
8825
visitBase__anonb2a824812611::SpecialMemberDeletionInfo8826 bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); }
visitField__anonb2a824812611::SpecialMemberDeletionInfo8827 bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); }
8828
8829 bool shouldDeleteForBase(CXXBaseSpecifier *Base);
8830 bool shouldDeleteForField(FieldDecl *FD);
8831 bool shouldDeleteForAllConstMembers();
8832
8833 bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
8834 unsigned Quals);
8835 bool shouldDeleteForSubobjectCall(Subobject Subobj,
8836 Sema::SpecialMemberOverloadResult SMOR,
8837 bool IsDtorCallInCtor);
8838
8839 bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
8840 };
8841 }
8842
8843 /// Is the given special member inaccessible when used on the given
8844 /// sub-object.
isAccessible(Subobject Subobj,CXXMethodDecl * target)8845 bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
8846 CXXMethodDecl *target) {
8847 /// If we're operating on a base class, the object type is the
8848 /// type of this special member.
8849 QualType objectTy;
8850 AccessSpecifier access = target->getAccess();
8851 if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
8852 objectTy = S.Context.getTypeDeclType(MD->getParent());
8853 access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
8854
8855 // If we're operating on a field, the object type is the type of the field.
8856 } else {
8857 objectTy = S.Context.getTypeDeclType(target->getParent());
8858 }
8859
8860 return S.isMemberAccessibleForDeletion(
8861 target->getParent(), DeclAccessPair::make(target, access), objectTy);
8862 }
8863
8864 /// Check whether we should delete a special member due to the implicit
8865 /// definition containing a call to a special member of a subobject.
shouldDeleteForSubobjectCall(Subobject Subobj,Sema::SpecialMemberOverloadResult SMOR,bool IsDtorCallInCtor)8866 bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
8867 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR,
8868 bool IsDtorCallInCtor) {
8869 CXXMethodDecl *Decl = SMOR.getMethod();
8870 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
8871
8872 int DiagKind = -1;
8873
8874 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
8875 DiagKind = !Decl ? 0 : 1;
8876 else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
8877 DiagKind = 2;
8878 else if (!isAccessible(Subobj, Decl))
8879 DiagKind = 3;
8880 else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
8881 !Decl->isTrivial()) {
8882 // A member of a union must have a trivial corresponding special member.
8883 // As a weird special case, a destructor call from a union's constructor
8884 // must be accessible and non-deleted, but need not be trivial. Such a
8885 // destructor is never actually called, but is semantically checked as
8886 // if it were.
8887 DiagKind = 4;
8888 }
8889
8890 if (DiagKind == -1)
8891 return false;
8892
8893 if (Diagnose) {
8894 if (Field) {
8895 S.Diag(Field->getLocation(),
8896 diag::note_deleted_special_member_class_subobject)
8897 << getEffectiveCSM() << MD->getParent() << /*IsField*/true
8898 << Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false;
8899 } else {
8900 CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
8901 S.Diag(Base->getBeginLoc(),
8902 diag::note_deleted_special_member_class_subobject)
8903 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
8904 << Base->getType() << DiagKind << IsDtorCallInCtor
8905 << /*IsObjCPtr*/false;
8906 }
8907
8908 if (DiagKind == 1)
8909 S.NoteDeletedFunction(Decl);
8910 // FIXME: Explain inaccessibility if DiagKind == 3.
8911 }
8912
8913 return true;
8914 }
8915
8916 /// Check whether we should delete a special member function due to having a
8917 /// direct or virtual base class or non-static data member of class type M.
shouldDeleteForClassSubobject(CXXRecordDecl * Class,Subobject Subobj,unsigned Quals)8918 bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
8919 CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) {
8920 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
8921 bool IsMutable = Field && Field->isMutable();
8922
8923 // C++11 [class.ctor]p5:
8924 // -- any direct or virtual base class, or non-static data member with no
8925 // brace-or-equal-initializer, has class type M (or array thereof) and
8926 // either M has no default constructor or overload resolution as applied
8927 // to M's default constructor results in an ambiguity or in a function
8928 // that is deleted or inaccessible
8929 // C++11 [class.copy]p11, C++11 [class.copy]p23:
8930 // -- a direct or virtual base class B that cannot be copied/moved because
8931 // overload resolution, as applied to B's corresponding special member,
8932 // results in an ambiguity or a function that is deleted or inaccessible
8933 // from the defaulted special member
8934 // C++11 [class.dtor]p5:
8935 // -- any direct or virtual base class [...] has a type with a destructor
8936 // that is deleted or inaccessible
8937 if (!(CSM == Sema::CXXDefaultConstructor &&
8938 Field && Field->hasInClassInitializer()) &&
8939 shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable),
8940 false))
8941 return true;
8942
8943 // C++11 [class.ctor]p5, C++11 [class.copy]p11:
8944 // -- any direct or virtual base class or non-static data member has a
8945 // type with a destructor that is deleted or inaccessible
8946 if (IsConstructor) {
8947 Sema::SpecialMemberOverloadResult SMOR =
8948 S.LookupSpecialMember(Class, Sema::CXXDestructor,
8949 false, false, false, false, false);
8950 if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
8951 return true;
8952 }
8953
8954 return false;
8955 }
8956
shouldDeleteForVariantObjCPtrMember(FieldDecl * FD,QualType FieldType)8957 bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember(
8958 FieldDecl *FD, QualType FieldType) {
8959 // The defaulted special functions are defined as deleted if this is a variant
8960 // member with a non-trivial ownership type, e.g., ObjC __strong or __weak
8961 // type under ARC.
8962 if (!FieldType.hasNonTrivialObjCLifetime())
8963 return false;
8964
8965 // Don't make the defaulted default constructor defined as deleted if the
8966 // member has an in-class initializer.
8967 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer())
8968 return false;
8969
8970 if (Diagnose) {
8971 auto *ParentClass = cast<CXXRecordDecl>(FD->getParent());
8972 S.Diag(FD->getLocation(),
8973 diag::note_deleted_special_member_class_subobject)
8974 << getEffectiveCSM() << ParentClass << /*IsField*/true
8975 << FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true;
8976 }
8977
8978 return true;
8979 }
8980
8981 /// Check whether we should delete a special member function due to the class
8982 /// having a particular direct or virtual base class.
shouldDeleteForBase(CXXBaseSpecifier * Base)8983 bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
8984 CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
8985 // If program is correct, BaseClass cannot be null, but if it is, the error
8986 // must be reported elsewhere.
8987 if (!BaseClass)
8988 return false;
8989 // If we have an inheriting constructor, check whether we're calling an
8990 // inherited constructor instead of a default constructor.
8991 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
8992 if (auto *BaseCtor = SMOR.getMethod()) {
8993 // Note that we do not check access along this path; other than that,
8994 // this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false);
8995 // FIXME: Check that the base has a usable destructor! Sink this into
8996 // shouldDeleteForClassSubobject.
8997 if (BaseCtor->isDeleted() && Diagnose) {
8998 S.Diag(Base->getBeginLoc(),
8999 diag::note_deleted_special_member_class_subobject)
9000 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
9001 << Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false
9002 << /*IsObjCPtr*/false;
9003 S.NoteDeletedFunction(BaseCtor);
9004 }
9005 return BaseCtor->isDeleted();
9006 }
9007 return shouldDeleteForClassSubobject(BaseClass, Base, 0);
9008 }
9009
9010 /// Check whether we should delete a special member function due to the class
9011 /// having a particular non-static data member.
shouldDeleteForField(FieldDecl * FD)9012 bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
9013 QualType FieldType = S.Context.getBaseElementType(FD->getType());
9014 CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
9015
9016 if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType))
9017 return true;
9018
9019 if (CSM == Sema::CXXDefaultConstructor) {
9020 // For a default constructor, all references must be initialized in-class
9021 // and, if a union, it must have a non-const member.
9022 if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
9023 if (Diagnose)
9024 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
9025 << !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0;
9026 return true;
9027 }
9028 // C++11 [class.ctor]p5: any non-variant non-static data member of
9029 // const-qualified type (or array thereof) with no
9030 // brace-or-equal-initializer does not have a user-provided default
9031 // constructor.
9032 if (!inUnion() && FieldType.isConstQualified() &&
9033 !FD->hasInClassInitializer() &&
9034 (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
9035 if (Diagnose)
9036 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
9037 << !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1;
9038 return true;
9039 }
9040
9041 if (inUnion() && !FieldType.isConstQualified())
9042 AllFieldsAreConst = false;
9043 } else if (CSM == Sema::CXXCopyConstructor) {
9044 // For a copy constructor, data members must not be of rvalue reference
9045 // type.
9046 if (FieldType->isRValueReferenceType()) {
9047 if (Diagnose)
9048 S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
9049 << MD->getParent() << FD << FieldType;
9050 return true;
9051 }
9052 } else if (IsAssignment) {
9053 // For an assignment operator, data members must not be of reference type.
9054 if (FieldType->isReferenceType()) {
9055 if (Diagnose)
9056 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
9057 << isMove() << MD->getParent() << FD << FieldType << /*Reference*/0;
9058 return true;
9059 }
9060 if (!FieldRecord && FieldType.isConstQualified()) {
9061 // C++11 [class.copy]p23:
9062 // -- a non-static data member of const non-class type (or array thereof)
9063 if (Diagnose)
9064 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
9065 << isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1;
9066 return true;
9067 }
9068 }
9069
9070 if (FieldRecord) {
9071 // Some additional restrictions exist on the variant members.
9072 if (!inUnion() && FieldRecord->isUnion() &&
9073 FieldRecord->isAnonymousStructOrUnion()) {
9074 bool AllVariantFieldsAreConst = true;
9075
9076 // FIXME: Handle anonymous unions declared within anonymous unions.
9077 for (auto *UI : FieldRecord->fields()) {
9078 QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
9079
9080 if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType))
9081 return true;
9082
9083 if (!UnionFieldType.isConstQualified())
9084 AllVariantFieldsAreConst = false;
9085
9086 CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
9087 if (UnionFieldRecord &&
9088 shouldDeleteForClassSubobject(UnionFieldRecord, UI,
9089 UnionFieldType.getCVRQualifiers()))
9090 return true;
9091 }
9092
9093 // At least one member in each anonymous union must be non-const
9094 if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
9095 !FieldRecord->field_empty()) {
9096 if (Diagnose)
9097 S.Diag(FieldRecord->getLocation(),
9098 diag::note_deleted_default_ctor_all_const)
9099 << !!ICI << MD->getParent() << /*anonymous union*/1;
9100 return true;
9101 }
9102
9103 // Don't check the implicit member of the anonymous union type.
9104 // This is technically non-conformant, but sanity demands it.
9105 return false;
9106 }
9107
9108 if (shouldDeleteForClassSubobject(FieldRecord, FD,
9109 FieldType.getCVRQualifiers()))
9110 return true;
9111 }
9112
9113 return false;
9114 }
9115
9116 /// C++11 [class.ctor] p5:
9117 /// A defaulted default constructor for a class X is defined as deleted if
9118 /// X is a union and all of its variant members are of const-qualified type.
shouldDeleteForAllConstMembers()9119 bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
9120 // This is a silly definition, because it gives an empty union a deleted
9121 // default constructor. Don't do that.
9122 if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) {
9123 bool AnyFields = false;
9124 for (auto *F : MD->getParent()->fields())
9125 if ((AnyFields = !F->isUnnamedBitfield()))
9126 break;
9127 if (!AnyFields)
9128 return false;
9129 if (Diagnose)
9130 S.Diag(MD->getParent()->getLocation(),
9131 diag::note_deleted_default_ctor_all_const)
9132 << !!ICI << MD->getParent() << /*not anonymous union*/0;
9133 return true;
9134 }
9135 return false;
9136 }
9137
9138 /// Determine whether a defaulted special member function should be defined as
9139 /// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
9140 /// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
ShouldDeleteSpecialMember(CXXMethodDecl * MD,CXXSpecialMember CSM,InheritedConstructorInfo * ICI,bool Diagnose)9141 bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
9142 InheritedConstructorInfo *ICI,
9143 bool Diagnose) {
9144 if (MD->isInvalidDecl())
9145 return false;
9146 CXXRecordDecl *RD = MD->getParent();
9147 assert(!RD->isDependentType() && "do deletion after instantiation");
9148 if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl())
9149 return false;
9150
9151 // C++11 [expr.lambda.prim]p19:
9152 // The closure type associated with a lambda-expression has a
9153 // deleted (8.4.3) default constructor and a deleted copy
9154 // assignment operator.
9155 // C++2a adds back these operators if the lambda has no lambda-capture.
9156 if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() &&
9157 (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
9158 if (Diagnose)
9159 Diag(RD->getLocation(), diag::note_lambda_decl);
9160 return true;
9161 }
9162
9163 // For an anonymous struct or union, the copy and assignment special members
9164 // will never be used, so skip the check. For an anonymous union declared at
9165 // namespace scope, the constructor and destructor are used.
9166 if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
9167 RD->isAnonymousStructOrUnion())
9168 return false;
9169
9170 // C++11 [class.copy]p7, p18:
9171 // If the class definition declares a move constructor or move assignment
9172 // operator, an implicitly declared copy constructor or copy assignment
9173 // operator is defined as deleted.
9174 if (MD->isImplicit() &&
9175 (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
9176 CXXMethodDecl *UserDeclaredMove = nullptr;
9177
9178 // In Microsoft mode up to MSVC 2013, a user-declared move only causes the
9179 // deletion of the corresponding copy operation, not both copy operations.
9180 // MSVC 2015 has adopted the standards conforming behavior.
9181 bool DeletesOnlyMatchingCopy =
9182 getLangOpts().MSVCCompat &&
9183 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);
9184
9185 if (RD->hasUserDeclaredMoveConstructor() &&
9186 (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) {
9187 if (!Diagnose) return true;
9188
9189 // Find any user-declared move constructor.
9190 for (auto *I : RD->ctors()) {
9191 if (I->isMoveConstructor()) {
9192 UserDeclaredMove = I;
9193 break;
9194 }
9195 }
9196 assert(UserDeclaredMove);
9197 } else if (RD->hasUserDeclaredMoveAssignment() &&
9198 (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) {
9199 if (!Diagnose) return true;
9200
9201 // Find any user-declared move assignment operator.
9202 for (auto *I : RD->methods()) {
9203 if (I->isMoveAssignmentOperator()) {
9204 UserDeclaredMove = I;
9205 break;
9206 }
9207 }
9208 assert(UserDeclaredMove);
9209 }
9210
9211 if (UserDeclaredMove) {
9212 Diag(UserDeclaredMove->getLocation(),
9213 diag::note_deleted_copy_user_declared_move)
9214 << (CSM == CXXCopyAssignment) << RD
9215 << UserDeclaredMove->isMoveAssignmentOperator();
9216 return true;
9217 }
9218 }
9219
9220 // Do access control from the special member function
9221 ContextRAII MethodContext(*this, MD);
9222
9223 // C++11 [class.dtor]p5:
9224 // -- for a virtual destructor, lookup of the non-array deallocation function
9225 // results in an ambiguity or in a function that is deleted or inaccessible
9226 if (CSM == CXXDestructor && MD->isVirtual()) {
9227 FunctionDecl *OperatorDelete = nullptr;
9228 DeclarationName Name =
9229 Context.DeclarationNames.getCXXOperatorName(OO_Delete);
9230 if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
9231 OperatorDelete, /*Diagnose*/false)) {
9232 if (Diagnose)
9233 Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
9234 return true;
9235 }
9236 }
9237
9238 SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose);
9239
9240 // Per DR1611, do not consider virtual bases of constructors of abstract
9241 // classes, since we are not going to construct them.
9242 // Per DR1658, do not consider virtual bases of destructors of abstract
9243 // classes either.
9244 // Per DR2180, for assignment operators we only assign (and thus only
9245 // consider) direct bases.
9246 if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases
9247 : SMI.VisitPotentiallyConstructedBases))
9248 return true;
9249
9250 if (SMI.shouldDeleteForAllConstMembers())
9251 return true;
9252
9253 if (getLangOpts().CUDA) {
9254 // We should delete the special member in CUDA mode if target inference
9255 // failed.
9256 // For inherited constructors (non-null ICI), CSM may be passed so that MD
9257 // is treated as certain special member, which may not reflect what special
9258 // member MD really is. However inferCUDATargetForImplicitSpecialMember
9259 // expects CSM to match MD, therefore recalculate CSM.
9260 assert(ICI || CSM == getSpecialMember(MD));
9261 auto RealCSM = CSM;
9262 if (ICI)
9263 RealCSM = getSpecialMember(MD);
9264
9265 return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD,
9266 SMI.ConstArg, Diagnose);
9267 }
9268
9269 return false;
9270 }
9271
DiagnoseDeletedDefaultedFunction(FunctionDecl * FD)9272 void Sema::DiagnoseDeletedDefaultedFunction(FunctionDecl *FD) {
9273 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
9274 assert(DFK && "not a defaultable function");
9275 assert(FD->isDefaulted() && FD->isDeleted() && "not defaulted and deleted");
9276
9277 if (DFK.isSpecialMember()) {
9278 ShouldDeleteSpecialMember(cast<CXXMethodDecl>(FD), DFK.asSpecialMember(),
9279 nullptr, /*Diagnose=*/true);
9280 } else {
9281 DefaultedComparisonAnalyzer(
9282 *this, cast<CXXRecordDecl>(FD->getLexicalDeclContext()), FD,
9283 DFK.asComparison(), DefaultedComparisonAnalyzer::ExplainDeleted)
9284 .visit();
9285 }
9286 }
9287
9288 /// Perform lookup for a special member of the specified kind, and determine
9289 /// whether it is trivial. If the triviality can be determined without the
9290 /// lookup, skip it. This is intended for use when determining whether a
9291 /// special member of a containing object is trivial, and thus does not ever
9292 /// perform overload resolution for default constructors.
9293 ///
9294 /// If \p Selected is not \c NULL, \c *Selected will be filled in with the
9295 /// member that was most likely to be intended to be trivial, if any.
9296 ///
9297 /// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to
9298 /// determine whether the special member is trivial.
findTrivialSpecialMember(Sema & S,CXXRecordDecl * RD,Sema::CXXSpecialMember CSM,unsigned Quals,bool ConstRHS,Sema::TrivialABIHandling TAH,CXXMethodDecl ** Selected)9299 static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD,
9300 Sema::CXXSpecialMember CSM, unsigned Quals,
9301 bool ConstRHS,
9302 Sema::TrivialABIHandling TAH,
9303 CXXMethodDecl **Selected) {
9304 if (Selected)
9305 *Selected = nullptr;
9306
9307 switch (CSM) {
9308 case Sema::CXXInvalid:
9309 llvm_unreachable("not a special member");
9310
9311 case Sema::CXXDefaultConstructor:
9312 // C++11 [class.ctor]p5:
9313 // A default constructor is trivial if:
9314 // - all the [direct subobjects] have trivial default constructors
9315 //
9316 // Note, no overload resolution is performed in this case.
9317 if (RD->hasTrivialDefaultConstructor())
9318 return true;
9319
9320 if (Selected) {
9321 // If there's a default constructor which could have been trivial, dig it
9322 // out. Otherwise, if there's any user-provided default constructor, point
9323 // to that as an example of why there's not a trivial one.
9324 CXXConstructorDecl *DefCtor = nullptr;
9325 if (RD->needsImplicitDefaultConstructor())
9326 S.DeclareImplicitDefaultConstructor(RD);
9327 for (auto *CI : RD->ctors()) {
9328 if (!CI->isDefaultConstructor())
9329 continue;
9330 DefCtor = CI;
9331 if (!DefCtor->isUserProvided())
9332 break;
9333 }
9334
9335 *Selected = DefCtor;
9336 }
9337
9338 return false;
9339
9340 case Sema::CXXDestructor:
9341 // C++11 [class.dtor]p5:
9342 // A destructor is trivial if:
9343 // - all the direct [subobjects] have trivial destructors
9344 if (RD->hasTrivialDestructor() ||
9345 (TAH == Sema::TAH_ConsiderTrivialABI &&
9346 RD->hasTrivialDestructorForCall()))
9347 return true;
9348
9349 if (Selected) {
9350 if (RD->needsImplicitDestructor())
9351 S.DeclareImplicitDestructor(RD);
9352 *Selected = RD->getDestructor();
9353 }
9354
9355 return false;
9356
9357 case Sema::CXXCopyConstructor:
9358 // C++11 [class.copy]p12:
9359 // A copy constructor is trivial if:
9360 // - the constructor selected to copy each direct [subobject] is trivial
9361 if (RD->hasTrivialCopyConstructor() ||
9362 (TAH == Sema::TAH_ConsiderTrivialABI &&
9363 RD->hasTrivialCopyConstructorForCall())) {
9364 if (Quals == Qualifiers::Const)
9365 // We must either select the trivial copy constructor or reach an
9366 // ambiguity; no need to actually perform overload resolution.
9367 return true;
9368 } else if (!Selected) {
9369 return false;
9370 }
9371 // In C++98, we are not supposed to perform overload resolution here, but we
9372 // treat that as a language defect, as suggested on cxx-abi-dev, to treat
9373 // cases like B as having a non-trivial copy constructor:
9374 // struct A { template<typename T> A(T&); };
9375 // struct B { mutable A a; };
9376 goto NeedOverloadResolution;
9377
9378 case Sema::CXXCopyAssignment:
9379 // C++11 [class.copy]p25:
9380 // A copy assignment operator is trivial if:
9381 // - the assignment operator selected to copy each direct [subobject] is
9382 // trivial
9383 if (RD->hasTrivialCopyAssignment()) {
9384 if (Quals == Qualifiers::Const)
9385 return true;
9386 } else if (!Selected) {
9387 return false;
9388 }
9389 // In C++98, we are not supposed to perform overload resolution here, but we
9390 // treat that as a language defect.
9391 goto NeedOverloadResolution;
9392
9393 case Sema::CXXMoveConstructor:
9394 case Sema::CXXMoveAssignment:
9395 NeedOverloadResolution:
9396 Sema::SpecialMemberOverloadResult SMOR =
9397 lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS);
9398
9399 // The standard doesn't describe how to behave if the lookup is ambiguous.
9400 // We treat it as not making the member non-trivial, just like the standard
9401 // mandates for the default constructor. This should rarely matter, because
9402 // the member will also be deleted.
9403 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
9404 return true;
9405
9406 if (!SMOR.getMethod()) {
9407 assert(SMOR.getKind() ==
9408 Sema::SpecialMemberOverloadResult::NoMemberOrDeleted);
9409 return false;
9410 }
9411
9412 // We deliberately don't check if we found a deleted special member. We're
9413 // not supposed to!
9414 if (Selected)
9415 *Selected = SMOR.getMethod();
9416
9417 if (TAH == Sema::TAH_ConsiderTrivialABI &&
9418 (CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor))
9419 return SMOR.getMethod()->isTrivialForCall();
9420 return SMOR.getMethod()->isTrivial();
9421 }
9422
9423 llvm_unreachable("unknown special method kind");
9424 }
9425
findUserDeclaredCtor(CXXRecordDecl * RD)9426 static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) {
9427 for (auto *CI : RD->ctors())
9428 if (!CI->isImplicit())
9429 return CI;
9430
9431 // Look for constructor templates.
9432 typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter;
9433 for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) {
9434 if (CXXConstructorDecl *CD =
9435 dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl()))
9436 return CD;
9437 }
9438
9439 return nullptr;
9440 }
9441
9442 /// The kind of subobject we are checking for triviality. The values of this
9443 /// enumeration are used in diagnostics.
9444 enum TrivialSubobjectKind {
9445 /// The subobject is a base class.
9446 TSK_BaseClass,
9447 /// The subobject is a non-static data member.
9448 TSK_Field,
9449 /// The object is actually the complete object.
9450 TSK_CompleteObject
9451 };
9452
9453 /// Check whether the special member selected for a given type would be trivial.
checkTrivialSubobjectCall(Sema & S,SourceLocation SubobjLoc,QualType SubType,bool ConstRHS,Sema::CXXSpecialMember CSM,TrivialSubobjectKind Kind,Sema::TrivialABIHandling TAH,bool Diagnose)9454 static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc,
9455 QualType SubType, bool ConstRHS,
9456 Sema::CXXSpecialMember CSM,
9457 TrivialSubobjectKind Kind,
9458 Sema::TrivialABIHandling TAH, bool Diagnose) {
9459 CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl();
9460 if (!SubRD)
9461 return true;
9462
9463 CXXMethodDecl *Selected;
9464 if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(),
9465 ConstRHS, TAH, Diagnose ? &Selected : nullptr))
9466 return true;
9467
9468 if (Diagnose) {
9469 if (ConstRHS)
9470 SubType.addConst();
9471
9472 if (!Selected && CSM == Sema::CXXDefaultConstructor) {
9473 S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor)
9474 << Kind << SubType.getUnqualifiedType();
9475 if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD))
9476 S.Diag(CD->getLocation(), diag::note_user_declared_ctor);
9477 } else if (!Selected)
9478 S.Diag(SubobjLoc, diag::note_nontrivial_no_copy)
9479 << Kind << SubType.getUnqualifiedType() << CSM << SubType;
9480 else if (Selected->isUserProvided()) {
9481 if (Kind == TSK_CompleteObject)
9482 S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided)
9483 << Kind << SubType.getUnqualifiedType() << CSM;
9484 else {
9485 S.Diag(SubobjLoc, diag::note_nontrivial_user_provided)
9486 << Kind << SubType.getUnqualifiedType() << CSM;
9487 S.Diag(Selected->getLocation(), diag::note_declared_at);
9488 }
9489 } else {
9490 if (Kind != TSK_CompleteObject)
9491 S.Diag(SubobjLoc, diag::note_nontrivial_subobject)
9492 << Kind << SubType.getUnqualifiedType() << CSM;
9493
9494 // Explain why the defaulted or deleted special member isn't trivial.
9495 S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI,
9496 Diagnose);
9497 }
9498 }
9499
9500 return false;
9501 }
9502
9503 /// Check whether the members of a class type allow a special member to be
9504 /// trivial.
checkTrivialClassMembers(Sema & S,CXXRecordDecl * RD,Sema::CXXSpecialMember CSM,bool ConstArg,Sema::TrivialABIHandling TAH,bool Diagnose)9505 static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD,
9506 Sema::CXXSpecialMember CSM,
9507 bool ConstArg,
9508 Sema::TrivialABIHandling TAH,
9509 bool Diagnose) {
9510 for (const auto *FI : RD->fields()) {
9511 if (FI->isInvalidDecl() || FI->isUnnamedBitfield())
9512 continue;
9513
9514 QualType FieldType = S.Context.getBaseElementType(FI->getType());
9515
9516 // Pretend anonymous struct or union members are members of this class.
9517 if (FI->isAnonymousStructOrUnion()) {
9518 if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(),
9519 CSM, ConstArg, TAH, Diagnose))
9520 return false;
9521 continue;
9522 }
9523
9524 // C++11 [class.ctor]p5:
9525 // A default constructor is trivial if [...]
9526 // -- no non-static data member of its class has a
9527 // brace-or-equal-initializer
9528 if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) {
9529 if (Diagnose)
9530 S.Diag(FI->getLocation(), diag::note_nontrivial_default_member_init)
9531 << FI;
9532 return false;
9533 }
9534
9535 // Objective C ARC 4.3.5:
9536 // [...] nontrivally ownership-qualified types are [...] not trivially
9537 // default constructible, copy constructible, move constructible, copy
9538 // assignable, move assignable, or destructible [...]
9539 if (FieldType.hasNonTrivialObjCLifetime()) {
9540 if (Diagnose)
9541 S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership)
9542 << RD << FieldType.getObjCLifetime();
9543 return false;
9544 }
9545
9546 bool ConstRHS = ConstArg && !FI->isMutable();
9547 if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS,
9548 CSM, TSK_Field, TAH, Diagnose))
9549 return false;
9550 }
9551
9552 return true;
9553 }
9554
9555 /// Diagnose why the specified class does not have a trivial special member of
9556 /// the given kind.
DiagnoseNontrivial(const CXXRecordDecl * RD,CXXSpecialMember CSM)9557 void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) {
9558 QualType Ty = Context.getRecordType(RD);
9559
9560 bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment);
9561 checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM,
9562 TSK_CompleteObject, TAH_IgnoreTrivialABI,
9563 /*Diagnose*/true);
9564 }
9565
9566 /// Determine whether a defaulted or deleted special member function is trivial,
9567 /// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12,
9568 /// C++11 [class.copy]p25, and C++11 [class.dtor]p5.
SpecialMemberIsTrivial(CXXMethodDecl * MD,CXXSpecialMember CSM,TrivialABIHandling TAH,bool Diagnose)9569 bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
9570 TrivialABIHandling TAH, bool Diagnose) {
9571 assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough");
9572
9573 CXXRecordDecl *RD = MD->getParent();
9574
9575 bool ConstArg = false;
9576
9577 // C++11 [class.copy]p12, p25: [DR1593]
9578 // A [special member] is trivial if [...] its parameter-type-list is
9579 // equivalent to the parameter-type-list of an implicit declaration [...]
9580 switch (CSM) {
9581 case CXXDefaultConstructor:
9582 case CXXDestructor:
9583 // Trivial default constructors and destructors cannot have parameters.
9584 break;
9585
9586 case CXXCopyConstructor:
9587 case CXXCopyAssignment: {
9588 // Trivial copy operations always have const, non-volatile parameter types.
9589 ConstArg = true;
9590 const ParmVarDecl *Param0 = MD->getParamDecl(0);
9591 const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>();
9592 if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) {
9593 if (Diagnose)
9594 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
9595 << Param0->getSourceRange() << Param0->getType()
9596 << Context.getLValueReferenceType(
9597 Context.getRecordType(RD).withConst());
9598 return false;
9599 }
9600 break;
9601 }
9602
9603 case CXXMoveConstructor:
9604 case CXXMoveAssignment: {
9605 // Trivial move operations always have non-cv-qualified parameters.
9606 const ParmVarDecl *Param0 = MD->getParamDecl(0);
9607 const RValueReferenceType *RT =
9608 Param0->getType()->getAs<RValueReferenceType>();
9609 if (!RT || RT->getPointeeType().getCVRQualifiers()) {
9610 if (Diagnose)
9611 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
9612 << Param0->getSourceRange() << Param0->getType()
9613 << Context.getRValueReferenceType(Context.getRecordType(RD));
9614 return false;
9615 }
9616 break;
9617 }
9618
9619 case CXXInvalid:
9620 llvm_unreachable("not a special member");
9621 }
9622
9623 if (MD->getMinRequiredArguments() < MD->getNumParams()) {
9624 if (Diagnose)
9625 Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(),
9626 diag::note_nontrivial_default_arg)
9627 << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange();
9628 return false;
9629 }
9630 if (MD->isVariadic()) {
9631 if (Diagnose)
9632 Diag(MD->getLocation(), diag::note_nontrivial_variadic);
9633 return false;
9634 }
9635
9636 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
9637 // A copy/move [constructor or assignment operator] is trivial if
9638 // -- the [member] selected to copy/move each direct base class subobject
9639 // is trivial
9640 //
9641 // C++11 [class.copy]p12, C++11 [class.copy]p25:
9642 // A [default constructor or destructor] is trivial if
9643 // -- all the direct base classes have trivial [default constructors or
9644 // destructors]
9645 for (const auto &BI : RD->bases())
9646 if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(),
9647 ConstArg, CSM, TSK_BaseClass, TAH, Diagnose))
9648 return false;
9649
9650 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
9651 // A copy/move [constructor or assignment operator] for a class X is
9652 // trivial if
9653 // -- for each non-static data member of X that is of class type (or array
9654 // thereof), the constructor selected to copy/move that member is
9655 // trivial
9656 //
9657 // C++11 [class.copy]p12, C++11 [class.copy]p25:
9658 // A [default constructor or destructor] is trivial if
9659 // -- for all of the non-static data members of its class that are of class
9660 // type (or array thereof), each such class has a trivial [default
9661 // constructor or destructor]
9662 if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose))
9663 return false;
9664
9665 // C++11 [class.dtor]p5:
9666 // A destructor is trivial if [...]
9667 // -- the destructor is not virtual
9668 if (CSM == CXXDestructor && MD->isVirtual()) {
9669 if (Diagnose)
9670 Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD;
9671 return false;
9672 }
9673
9674 // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
9675 // A [special member] for class X is trivial if [...]
9676 // -- class X has no virtual functions and no virtual base classes
9677 if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) {
9678 if (!Diagnose)
9679 return false;
9680
9681 if (RD->getNumVBases()) {
9682 // Check for virtual bases. We already know that the corresponding
9683 // member in all bases is trivial, so vbases must all be direct.
9684 CXXBaseSpecifier &BS = *RD->vbases_begin();
9685 assert(BS.isVirtual());
9686 Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1;
9687 return false;
9688 }
9689
9690 // Must have a virtual method.
9691 for (const auto *MI : RD->methods()) {
9692 if (MI->isVirtual()) {
9693 SourceLocation MLoc = MI->getBeginLoc();
9694 Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0;
9695 return false;
9696 }
9697 }
9698
9699 llvm_unreachable("dynamic class with no vbases and no virtual functions");
9700 }
9701
9702 // Looks like it's trivial!
9703 return true;
9704 }
9705
9706 namespace {
9707 struct FindHiddenVirtualMethod {
9708 Sema *S;
9709 CXXMethodDecl *Method;
9710 llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
9711 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
9712
9713 private:
9714 /// Check whether any most overridden method from MD in Methods
CheckMostOverridenMethods__anonb2a824812711::FindHiddenVirtualMethod9715 static bool CheckMostOverridenMethods(
9716 const CXXMethodDecl *MD,
9717 const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) {
9718 if (MD->size_overridden_methods() == 0)
9719 return Methods.count(MD->getCanonicalDecl());
9720 for (const CXXMethodDecl *O : MD->overridden_methods())
9721 if (CheckMostOverridenMethods(O, Methods))
9722 return true;
9723 return false;
9724 }
9725
9726 public:
9727 /// Member lookup function that determines whether a given C++
9728 /// method overloads virtual methods in a base class without overriding any,
9729 /// to be used with CXXRecordDecl::lookupInBases().
operator ()__anonb2a824812711::FindHiddenVirtualMethod9730 bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
9731 RecordDecl *BaseRecord =
9732 Specifier->getType()->castAs<RecordType>()->getDecl();
9733
9734 DeclarationName Name = Method->getDeclName();
9735 assert(Name.getNameKind() == DeclarationName::Identifier);
9736
9737 bool foundSameNameMethod = false;
9738 SmallVector<CXXMethodDecl *, 8> overloadedMethods;
9739 for (Path.Decls = BaseRecord->lookup(Name).begin();
9740 Path.Decls != DeclContext::lookup_iterator(); ++Path.Decls) {
9741 NamedDecl *D = *Path.Decls;
9742 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
9743 MD = MD->getCanonicalDecl();
9744 foundSameNameMethod = true;
9745 // Interested only in hidden virtual methods.
9746 if (!MD->isVirtual())
9747 continue;
9748 // If the method we are checking overrides a method from its base
9749 // don't warn about the other overloaded methods. Clang deviates from
9750 // GCC by only diagnosing overloads of inherited virtual functions that
9751 // do not override any other virtual functions in the base. GCC's
9752 // -Woverloaded-virtual diagnoses any derived function hiding a virtual
9753 // function from a base class. These cases may be better served by a
9754 // warning (not specific to virtual functions) on call sites when the
9755 // call would select a different function from the base class, were it
9756 // visible.
9757 // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example.
9758 if (!S->IsOverload(Method, MD, false))
9759 return true;
9760 // Collect the overload only if its hidden.
9761 if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods))
9762 overloadedMethods.push_back(MD);
9763 }
9764 }
9765
9766 if (foundSameNameMethod)
9767 OverloadedMethods.append(overloadedMethods.begin(),
9768 overloadedMethods.end());
9769 return foundSameNameMethod;
9770 }
9771 };
9772 } // end anonymous namespace
9773
9774 /// Add the most overriden methods from MD to Methods
AddMostOverridenMethods(const CXXMethodDecl * MD,llvm::SmallPtrSetImpl<const CXXMethodDecl * > & Methods)9775 static void AddMostOverridenMethods(const CXXMethodDecl *MD,
9776 llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) {
9777 if (MD->size_overridden_methods() == 0)
9778 Methods.insert(MD->getCanonicalDecl());
9779 else
9780 for (const CXXMethodDecl *O : MD->overridden_methods())
9781 AddMostOverridenMethods(O, Methods);
9782 }
9783
9784 /// Check if a method overloads virtual methods in a base class without
9785 /// overriding any.
FindHiddenVirtualMethods(CXXMethodDecl * MD,SmallVectorImpl<CXXMethodDecl * > & OverloadedMethods)9786 void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD,
9787 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
9788 if (!MD->getDeclName().isIdentifier())
9789 return;
9790
9791 CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
9792 /*bool RecordPaths=*/false,
9793 /*bool DetectVirtual=*/false);
9794 FindHiddenVirtualMethod FHVM;
9795 FHVM.Method = MD;
9796 FHVM.S = this;
9797
9798 // Keep the base methods that were overridden or introduced in the subclass
9799 // by 'using' in a set. A base method not in this set is hidden.
9800 CXXRecordDecl *DC = MD->getParent();
9801 DeclContext::lookup_result R = DC->lookup(MD->getDeclName());
9802 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
9803 NamedDecl *ND = *I;
9804 if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I))
9805 ND = shad->getTargetDecl();
9806 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
9807 AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods);
9808 }
9809
9810 if (DC->lookupInBases(FHVM, Paths))
9811 OverloadedMethods = FHVM.OverloadedMethods;
9812 }
9813
NoteHiddenVirtualMethods(CXXMethodDecl * MD,SmallVectorImpl<CXXMethodDecl * > & OverloadedMethods)9814 void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD,
9815 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
9816 for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) {
9817 CXXMethodDecl *overloadedMD = OverloadedMethods[i];
9818 PartialDiagnostic PD = PDiag(
9819 diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
9820 HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType());
9821 Diag(overloadedMD->getLocation(), PD);
9822 }
9823 }
9824
9825 /// Diagnose methods which overload virtual methods in a base class
9826 /// without overriding any.
DiagnoseHiddenVirtualMethods(CXXMethodDecl * MD)9827 void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) {
9828 if (MD->isInvalidDecl())
9829 return;
9830
9831 if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation()))
9832 return;
9833
9834 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
9835 FindHiddenVirtualMethods(MD, OverloadedMethods);
9836 if (!OverloadedMethods.empty()) {
9837 Diag(MD->getLocation(), diag::warn_overloaded_virtual)
9838 << MD << (OverloadedMethods.size() > 1);
9839
9840 NoteHiddenVirtualMethods(MD, OverloadedMethods);
9841 }
9842 }
9843
checkIllFormedTrivialABIStruct(CXXRecordDecl & RD)9844 void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) {
9845 auto PrintDiagAndRemoveAttr = [&](unsigned N) {
9846 // No diagnostics if this is a template instantiation.
9847 if (!isTemplateInstantiation(RD.getTemplateSpecializationKind())) {
9848 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
9849 diag::ext_cannot_use_trivial_abi) << &RD;
9850 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
9851 diag::note_cannot_use_trivial_abi_reason) << &RD << N;
9852 }
9853 RD.dropAttr<TrivialABIAttr>();
9854 };
9855
9856 // Ill-formed if the copy and move constructors are deleted.
9857 auto HasNonDeletedCopyOrMoveConstructor = [&]() {
9858 // If the type is dependent, then assume it might have
9859 // implicit copy or move ctor because we won't know yet at this point.
9860 if (RD.isDependentType())
9861 return true;
9862 if (RD.needsImplicitCopyConstructor() &&
9863 !RD.defaultedCopyConstructorIsDeleted())
9864 return true;
9865 if (RD.needsImplicitMoveConstructor() &&
9866 !RD.defaultedMoveConstructorIsDeleted())
9867 return true;
9868 for (const CXXConstructorDecl *CD : RD.ctors())
9869 if (CD->isCopyOrMoveConstructor() && !CD->isDeleted())
9870 return true;
9871 return false;
9872 };
9873
9874 if (!HasNonDeletedCopyOrMoveConstructor()) {
9875 PrintDiagAndRemoveAttr(0);
9876 return;
9877 }
9878
9879 // Ill-formed if the struct has virtual functions.
9880 if (RD.isPolymorphic()) {
9881 PrintDiagAndRemoveAttr(1);
9882 return;
9883 }
9884
9885 for (const auto &B : RD.bases()) {
9886 // Ill-formed if the base class is non-trivial for the purpose of calls or a
9887 // virtual base.
9888 if (!B.getType()->isDependentType() &&
9889 !B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) {
9890 PrintDiagAndRemoveAttr(2);
9891 return;
9892 }
9893
9894 if (B.isVirtual()) {
9895 PrintDiagAndRemoveAttr(3);
9896 return;
9897 }
9898 }
9899
9900 for (const auto *FD : RD.fields()) {
9901 // Ill-formed if the field is an ObjectiveC pointer or of a type that is
9902 // non-trivial for the purpose of calls.
9903 QualType FT = FD->getType();
9904 if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) {
9905 PrintDiagAndRemoveAttr(4);
9906 return;
9907 }
9908
9909 if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>())
9910 if (!RT->isDependentType() &&
9911 !cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) {
9912 PrintDiagAndRemoveAttr(5);
9913 return;
9914 }
9915 }
9916 }
9917
ActOnFinishCXXMemberSpecification(Scope * S,SourceLocation RLoc,Decl * TagDecl,SourceLocation LBrac,SourceLocation RBrac,const ParsedAttributesView & AttrList)9918 void Sema::ActOnFinishCXXMemberSpecification(
9919 Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac,
9920 SourceLocation RBrac, const ParsedAttributesView &AttrList) {
9921 if (!TagDecl)
9922 return;
9923
9924 AdjustDeclIfTemplate(TagDecl);
9925
9926 for (const ParsedAttr &AL : AttrList) {
9927 if (AL.getKind() != ParsedAttr::AT_Visibility)
9928 continue;
9929 AL.setInvalid();
9930 Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL;
9931 }
9932
9933 ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
9934 // strict aliasing violation!
9935 reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
9936 FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
9937
9938 CheckCompletedCXXClass(S, cast<CXXRecordDecl>(TagDecl));
9939 }
9940
9941 /// Find the equality comparison functions that should be implicitly declared
9942 /// in a given class definition, per C++2a [class.compare.default]p3.
findImplicitlyDeclaredEqualityComparisons(ASTContext & Ctx,CXXRecordDecl * RD,llvm::SmallVectorImpl<FunctionDecl * > & Spaceships)9943 static void findImplicitlyDeclaredEqualityComparisons(
9944 ASTContext &Ctx, CXXRecordDecl *RD,
9945 llvm::SmallVectorImpl<FunctionDecl *> &Spaceships) {
9946 DeclarationName EqEq = Ctx.DeclarationNames.getCXXOperatorName(OO_EqualEqual);
9947 if (!RD->lookup(EqEq).empty())
9948 // Member operator== explicitly declared: no implicit operator==s.
9949 return;
9950
9951 // Traverse friends looking for an '==' or a '<=>'.
9952 for (FriendDecl *Friend : RD->friends()) {
9953 FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Friend->getFriendDecl());
9954 if (!FD) continue;
9955
9956 if (FD->getOverloadedOperator() == OO_EqualEqual) {
9957 // Friend operator== explicitly declared: no implicit operator==s.
9958 Spaceships.clear();
9959 return;
9960 }
9961
9962 if (FD->getOverloadedOperator() == OO_Spaceship &&
9963 FD->isExplicitlyDefaulted())
9964 Spaceships.push_back(FD);
9965 }
9966
9967 // Look for members named 'operator<=>'.
9968 DeclarationName Cmp = Ctx.DeclarationNames.getCXXOperatorName(OO_Spaceship);
9969 for (NamedDecl *ND : RD->lookup(Cmp)) {
9970 // Note that we could find a non-function here (either a function template
9971 // or a using-declaration). Neither case results in an implicit
9972 // 'operator=='.
9973 if (auto *FD = dyn_cast<FunctionDecl>(ND))
9974 if (FD->isExplicitlyDefaulted())
9975 Spaceships.push_back(FD);
9976 }
9977 }
9978
9979 /// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
9980 /// special functions, such as the default constructor, copy
9981 /// constructor, or destructor, to the given C++ class (C++
9982 /// [special]p1). This routine can only be executed just before the
9983 /// definition of the class is complete.
AddImplicitlyDeclaredMembersToClass(CXXRecordDecl * ClassDecl)9984 void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
9985 // Don't add implicit special members to templated classes.
9986 // FIXME: This means unqualified lookups for 'operator=' within a class
9987 // template don't work properly.
9988 if (!ClassDecl->isDependentType()) {
9989 if (ClassDecl->needsImplicitDefaultConstructor()) {
9990 ++getASTContext().NumImplicitDefaultConstructors;
9991
9992 if (ClassDecl->hasInheritedConstructor())
9993 DeclareImplicitDefaultConstructor(ClassDecl);
9994 }
9995
9996 if (ClassDecl->needsImplicitCopyConstructor()) {
9997 ++getASTContext().NumImplicitCopyConstructors;
9998
9999 // If the properties or semantics of the copy constructor couldn't be
10000 // determined while the class was being declared, force a declaration
10001 // of it now.
10002 if (ClassDecl->needsOverloadResolutionForCopyConstructor() ||
10003 ClassDecl->hasInheritedConstructor())
10004 DeclareImplicitCopyConstructor(ClassDecl);
10005 // For the MS ABI we need to know whether the copy ctor is deleted. A
10006 // prerequisite for deleting the implicit copy ctor is that the class has
10007 // a move ctor or move assignment that is either user-declared or whose
10008 // semantics are inherited from a subobject. FIXME: We should provide a
10009 // more direct way for CodeGen to ask whether the constructor was deleted.
10010 else if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
10011 (ClassDecl->hasUserDeclaredMoveConstructor() ||
10012 ClassDecl->needsOverloadResolutionForMoveConstructor() ||
10013 ClassDecl->hasUserDeclaredMoveAssignment() ||
10014 ClassDecl->needsOverloadResolutionForMoveAssignment()))
10015 DeclareImplicitCopyConstructor(ClassDecl);
10016 }
10017
10018 if (getLangOpts().CPlusPlus11 &&
10019 ClassDecl->needsImplicitMoveConstructor()) {
10020 ++getASTContext().NumImplicitMoveConstructors;
10021
10022 if (ClassDecl->needsOverloadResolutionForMoveConstructor() ||
10023 ClassDecl->hasInheritedConstructor())
10024 DeclareImplicitMoveConstructor(ClassDecl);
10025 }
10026
10027 if (ClassDecl->needsImplicitCopyAssignment()) {
10028 ++getASTContext().NumImplicitCopyAssignmentOperators;
10029
10030 // If we have a dynamic class, then the copy assignment operator may be
10031 // virtual, so we have to declare it immediately. This ensures that, e.g.,
10032 // it shows up in the right place in the vtable and that we diagnose
10033 // problems with the implicit exception specification.
10034 if (ClassDecl->isDynamicClass() ||
10035 ClassDecl->needsOverloadResolutionForCopyAssignment() ||
10036 ClassDecl->hasInheritedAssignment())
10037 DeclareImplicitCopyAssignment(ClassDecl);
10038 }
10039
10040 if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) {
10041 ++getASTContext().NumImplicitMoveAssignmentOperators;
10042
10043 // Likewise for the move assignment operator.
10044 if (ClassDecl->isDynamicClass() ||
10045 ClassDecl->needsOverloadResolutionForMoveAssignment() ||
10046 ClassDecl->hasInheritedAssignment())
10047 DeclareImplicitMoveAssignment(ClassDecl);
10048 }
10049
10050 if (ClassDecl->needsImplicitDestructor()) {
10051 ++getASTContext().NumImplicitDestructors;
10052
10053 // If we have a dynamic class, then the destructor may be virtual, so we
10054 // have to declare the destructor immediately. This ensures that, e.g., it
10055 // shows up in the right place in the vtable and that we diagnose problems
10056 // with the implicit exception specification.
10057 if (ClassDecl->isDynamicClass() ||
10058 ClassDecl->needsOverloadResolutionForDestructor())
10059 DeclareImplicitDestructor(ClassDecl);
10060 }
10061 }
10062
10063 // C++2a [class.compare.default]p3:
10064 // If the member-specification does not explicitly declare any member or
10065 // friend named operator==, an == operator function is declared implicitly
10066 // for each defaulted three-way comparison operator function defined in
10067 // the member-specification
10068 // FIXME: Consider doing this lazily.
10069 // We do this during the initial parse for a class template, not during
10070 // instantiation, so that we can handle unqualified lookups for 'operator=='
10071 // when parsing the template.
10072 if (getLangOpts().CPlusPlus20 && !inTemplateInstantiation()) {
10073 llvm::SmallVector<FunctionDecl *, 4> DefaultedSpaceships;
10074 findImplicitlyDeclaredEqualityComparisons(Context, ClassDecl,
10075 DefaultedSpaceships);
10076 for (auto *FD : DefaultedSpaceships)
10077 DeclareImplicitEqualityComparison(ClassDecl, FD);
10078 }
10079 }
10080
10081 unsigned
ActOnReenterTemplateScope(Decl * D,llvm::function_ref<Scope * ()> EnterScope)10082 Sema::ActOnReenterTemplateScope(Decl *D,
10083 llvm::function_ref<Scope *()> EnterScope) {
10084 if (!D)
10085 return 0;
10086 AdjustDeclIfTemplate(D);
10087
10088 // In order to get name lookup right, reenter template scopes in order from
10089 // outermost to innermost.
10090 SmallVector<TemplateParameterList *, 4> ParameterLists;
10091 DeclContext *LookupDC = dyn_cast<DeclContext>(D);
10092
10093 if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
10094 for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i)
10095 ParameterLists.push_back(DD->getTemplateParameterList(i));
10096
10097 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
10098 if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate())
10099 ParameterLists.push_back(FTD->getTemplateParameters());
10100 } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
10101 LookupDC = VD->getDeclContext();
10102
10103 if (VarTemplateDecl *VTD = VD->getDescribedVarTemplate())
10104 ParameterLists.push_back(VTD->getTemplateParameters());
10105 else if (auto *PSD = dyn_cast<VarTemplatePartialSpecializationDecl>(D))
10106 ParameterLists.push_back(PSD->getTemplateParameters());
10107 }
10108 } else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
10109 for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i)
10110 ParameterLists.push_back(TD->getTemplateParameterList(i));
10111
10112 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
10113 if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate())
10114 ParameterLists.push_back(CTD->getTemplateParameters());
10115 else if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
10116 ParameterLists.push_back(PSD->getTemplateParameters());
10117 }
10118 }
10119 // FIXME: Alias declarations and concepts.
10120
10121 unsigned Count = 0;
10122 Scope *InnermostTemplateScope = nullptr;
10123 for (TemplateParameterList *Params : ParameterLists) {
10124 // Ignore explicit specializations; they don't contribute to the template
10125 // depth.
10126 if (Params->size() == 0)
10127 continue;
10128
10129 InnermostTemplateScope = EnterScope();
10130 for (NamedDecl *Param : *Params) {
10131 if (Param->getDeclName()) {
10132 InnermostTemplateScope->AddDecl(Param);
10133 IdResolver.AddDecl(Param);
10134 }
10135 }
10136 ++Count;
10137 }
10138
10139 // Associate the new template scopes with the corresponding entities.
10140 if (InnermostTemplateScope) {
10141 assert(LookupDC && "no enclosing DeclContext for template lookup");
10142 EnterTemplatedContext(InnermostTemplateScope, LookupDC);
10143 }
10144
10145 return Count;
10146 }
10147
ActOnStartDelayedMemberDeclarations(Scope * S,Decl * RecordD)10148 void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
10149 if (!RecordD) return;
10150 AdjustDeclIfTemplate(RecordD);
10151 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
10152 PushDeclContext(S, Record);
10153 }
10154
ActOnFinishDelayedMemberDeclarations(Scope * S,Decl * RecordD)10155 void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
10156 if (!RecordD) return;
10157 PopDeclContext();
10158 }
10159
10160 /// This is used to implement the constant expression evaluation part of the
10161 /// attribute enable_if extension. There is nothing in standard C++ which would
10162 /// require reentering parameters.
ActOnReenterCXXMethodParameter(Scope * S,ParmVarDecl * Param)10163 void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) {
10164 if (!Param)
10165 return;
10166
10167 S->AddDecl(Param);
10168 if (Param->getDeclName())
10169 IdResolver.AddDecl(Param);
10170 }
10171
10172 /// ActOnStartDelayedCXXMethodDeclaration - We have completed
10173 /// parsing a top-level (non-nested) C++ class, and we are now
10174 /// parsing those parts of the given Method declaration that could
10175 /// not be parsed earlier (C++ [class.mem]p2), such as default
10176 /// arguments. This action should enter the scope of the given
10177 /// Method declaration as if we had just parsed the qualified method
10178 /// name. However, it should not bring the parameters into scope;
10179 /// that will be performed by ActOnDelayedCXXMethodParameter.
ActOnStartDelayedCXXMethodDeclaration(Scope * S,Decl * MethodD)10180 void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
10181 }
10182
10183 /// ActOnDelayedCXXMethodParameter - We've already started a delayed
10184 /// C++ method declaration. We're (re-)introducing the given
10185 /// function parameter into scope for use in parsing later parts of
10186 /// the method declaration. For example, we could see an
10187 /// ActOnParamDefaultArgument event for this parameter.
ActOnDelayedCXXMethodParameter(Scope * S,Decl * ParamD)10188 void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
10189 if (!ParamD)
10190 return;
10191
10192 ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
10193
10194 S->AddDecl(Param);
10195 if (Param->getDeclName())
10196 IdResolver.AddDecl(Param);
10197 }
10198
10199 /// ActOnFinishDelayedCXXMethodDeclaration - We have finished
10200 /// processing the delayed method declaration for Method. The method
10201 /// declaration is now considered finished. There may be a separate
10202 /// ActOnStartOfFunctionDef action later (not necessarily
10203 /// immediately!) for this method, if it was also defined inside the
10204 /// class body.
ActOnFinishDelayedCXXMethodDeclaration(Scope * S,Decl * MethodD)10205 void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
10206 if (!MethodD)
10207 return;
10208
10209 AdjustDeclIfTemplate(MethodD);
10210
10211 FunctionDecl *Method = cast<FunctionDecl>(MethodD);
10212
10213 // Now that we have our default arguments, check the constructor
10214 // again. It could produce additional diagnostics or affect whether
10215 // the class has implicitly-declared destructors, among other
10216 // things.
10217 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
10218 CheckConstructor(Constructor);
10219
10220 // Check the default arguments, which we may have added.
10221 if (!Method->isInvalidDecl())
10222 CheckCXXDefaultArguments(Method);
10223 }
10224
10225 // Emit the given diagnostic for each non-address-space qualifier.
10226 // Common part of CheckConstructorDeclarator and CheckDestructorDeclarator.
checkMethodTypeQualifiers(Sema & S,Declarator & D,unsigned DiagID)10227 static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) {
10228 const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
10229 if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) {
10230 bool DiagOccured = false;
10231 FTI.MethodQualifiers->forEachQualifier(
10232 [DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName,
10233 SourceLocation SL) {
10234 // This diagnostic should be emitted on any qualifier except an addr
10235 // space qualifier. However, forEachQualifier currently doesn't visit
10236 // addr space qualifiers, so there's no way to write this condition
10237 // right now; we just diagnose on everything.
10238 S.Diag(SL, DiagID) << QualName << SourceRange(SL);
10239 DiagOccured = true;
10240 });
10241 if (DiagOccured)
10242 D.setInvalidType();
10243 }
10244 }
10245
10246 /// CheckConstructorDeclarator - Called by ActOnDeclarator to check
10247 /// the well-formedness of the constructor declarator @p D with type @p
10248 /// R. If there are any errors in the declarator, this routine will
10249 /// emit diagnostics and set the invalid bit to true. In any case, the type
10250 /// will be updated to reflect a well-formed type for the constructor and
10251 /// returned.
CheckConstructorDeclarator(Declarator & D,QualType R,StorageClass & SC)10252 QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
10253 StorageClass &SC) {
10254 bool isVirtual = D.getDeclSpec().isVirtualSpecified();
10255
10256 // C++ [class.ctor]p3:
10257 // A constructor shall not be virtual (10.3) or static (9.4). A
10258 // constructor can be invoked for a const, volatile or const
10259 // volatile object. A constructor shall not be declared const,
10260 // volatile, or const volatile (9.3.2).
10261 if (isVirtual) {
10262 if (!D.isInvalidType())
10263 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
10264 << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
10265 << SourceRange(D.getIdentifierLoc());
10266 D.setInvalidType();
10267 }
10268 if (SC == SC_Static) {
10269 if (!D.isInvalidType())
10270 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
10271 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10272 << SourceRange(D.getIdentifierLoc());
10273 D.setInvalidType();
10274 SC = SC_None;
10275 }
10276
10277 if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
10278 diagnoseIgnoredQualifiers(
10279 diag::err_constructor_return_type, TypeQuals, SourceLocation(),
10280 D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(),
10281 D.getDeclSpec().getRestrictSpecLoc(),
10282 D.getDeclSpec().getAtomicSpecLoc());
10283 D.setInvalidType();
10284 }
10285
10286 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor);
10287
10288 // C++0x [class.ctor]p4:
10289 // A constructor shall not be declared with a ref-qualifier.
10290 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
10291 if (FTI.hasRefQualifier()) {
10292 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
10293 << FTI.RefQualifierIsLValueRef
10294 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
10295 D.setInvalidType();
10296 }
10297
10298 // Rebuild the function type "R" without any type qualifiers (in
10299 // case any of the errors above fired) and with "void" as the
10300 // return type, since constructors don't have return types.
10301 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
10302 if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType())
10303 return R;
10304
10305 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
10306 EPI.TypeQuals = Qualifiers();
10307 EPI.RefQualifier = RQ_None;
10308
10309 return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI);
10310 }
10311
10312 /// CheckConstructor - Checks a fully-formed constructor for
10313 /// well-formedness, issuing any diagnostics required. Returns true if
10314 /// the constructor declarator is invalid.
CheckConstructor(CXXConstructorDecl * Constructor)10315 void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
10316 CXXRecordDecl *ClassDecl
10317 = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
10318 if (!ClassDecl)
10319 return Constructor->setInvalidDecl();
10320
10321 // C++ [class.copy]p3:
10322 // A declaration of a constructor for a class X is ill-formed if
10323 // its first parameter is of type (optionally cv-qualified) X and
10324 // either there are no other parameters or else all other
10325 // parameters have default arguments.
10326 if (!Constructor->isInvalidDecl() &&
10327 Constructor->hasOneParamOrDefaultArgs() &&
10328 Constructor->getTemplateSpecializationKind() !=
10329 TSK_ImplicitInstantiation) {
10330 QualType ParamType = Constructor->getParamDecl(0)->getType();
10331 QualType ClassTy = Context.getTagDeclType(ClassDecl);
10332 if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
10333 SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
10334 const char *ConstRef
10335 = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
10336 : " const &";
10337 Diag(ParamLoc, diag::err_constructor_byvalue_arg)
10338 << FixItHint::CreateInsertion(ParamLoc, ConstRef);
10339
10340 // FIXME: Rather that making the constructor invalid, we should endeavor
10341 // to fix the type.
10342 Constructor->setInvalidDecl();
10343 }
10344 }
10345 }
10346
10347 /// CheckDestructor - Checks a fully-formed destructor definition for
10348 /// well-formedness, issuing any diagnostics required. Returns true
10349 /// on error.
CheckDestructor(CXXDestructorDecl * Destructor)10350 bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
10351 CXXRecordDecl *RD = Destructor->getParent();
10352
10353 if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) {
10354 SourceLocation Loc;
10355
10356 if (!Destructor->isImplicit())
10357 Loc = Destructor->getLocation();
10358 else
10359 Loc = RD->getLocation();
10360
10361 // If we have a virtual destructor, look up the deallocation function
10362 if (FunctionDecl *OperatorDelete =
10363 FindDeallocationFunctionForDestructor(Loc, RD)) {
10364 Expr *ThisArg = nullptr;
10365
10366 // If the notional 'delete this' expression requires a non-trivial
10367 // conversion from 'this' to the type of a destroying operator delete's
10368 // first parameter, perform that conversion now.
10369 if (OperatorDelete->isDestroyingOperatorDelete()) {
10370 QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
10371 if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) {
10372 // C++ [class.dtor]p13:
10373 // ... as if for the expression 'delete this' appearing in a
10374 // non-virtual destructor of the destructor's class.
10375 ContextRAII SwitchContext(*this, Destructor);
10376 ExprResult This =
10377 ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation());
10378 assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?");
10379 This = PerformImplicitConversion(This.get(), ParamType, AA_Passing);
10380 if (This.isInvalid()) {
10381 // FIXME: Register this as a context note so that it comes out
10382 // in the right order.
10383 Diag(Loc, diag::note_implicit_delete_this_in_destructor_here);
10384 return true;
10385 }
10386 ThisArg = This.get();
10387 }
10388 }
10389
10390 DiagnoseUseOfDecl(OperatorDelete, Loc);
10391 MarkFunctionReferenced(Loc, OperatorDelete);
10392 Destructor->setOperatorDelete(OperatorDelete, ThisArg);
10393 }
10394 }
10395
10396 return false;
10397 }
10398
10399 /// CheckDestructorDeclarator - Called by ActOnDeclarator to check
10400 /// the well-formednes of the destructor declarator @p D with type @p
10401 /// R. If there are any errors in the declarator, this routine will
10402 /// emit diagnostics and set the declarator to invalid. Even if this happens,
10403 /// will be updated to reflect a well-formed type for the destructor and
10404 /// returned.
CheckDestructorDeclarator(Declarator & D,QualType R,StorageClass & SC)10405 QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
10406 StorageClass& SC) {
10407 // C++ [class.dtor]p1:
10408 // [...] A typedef-name that names a class is a class-name
10409 // (7.1.3); however, a typedef-name that names a class shall not
10410 // be used as the identifier in the declarator for a destructor
10411 // declaration.
10412 QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
10413 if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
10414 Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
10415 << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
10416 else if (const TemplateSpecializationType *TST =
10417 DeclaratorType->getAs<TemplateSpecializationType>())
10418 if (TST->isTypeAlias())
10419 Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
10420 << DeclaratorType << 1;
10421
10422 // C++ [class.dtor]p2:
10423 // A destructor is used to destroy objects of its class type. A
10424 // destructor takes no parameters, and no return type can be
10425 // specified for it (not even void). The address of a destructor
10426 // shall not be taken. A destructor shall not be static. A
10427 // destructor can be invoked for a const, volatile or const
10428 // volatile object. A destructor shall not be declared const,
10429 // volatile or const volatile (9.3.2).
10430 if (SC == SC_Static) {
10431 if (!D.isInvalidType())
10432 Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
10433 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10434 << SourceRange(D.getIdentifierLoc())
10435 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
10436
10437 SC = SC_None;
10438 }
10439 if (!D.isInvalidType()) {
10440 // Destructors don't have return types, but the parser will
10441 // happily parse something like:
10442 //
10443 // class X {
10444 // float ~X();
10445 // };
10446 //
10447 // The return type will be eliminated later.
10448 if (D.getDeclSpec().hasTypeSpecifier())
10449 Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
10450 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
10451 << SourceRange(D.getIdentifierLoc());
10452 else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
10453 diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals,
10454 SourceLocation(),
10455 D.getDeclSpec().getConstSpecLoc(),
10456 D.getDeclSpec().getVolatileSpecLoc(),
10457 D.getDeclSpec().getRestrictSpecLoc(),
10458 D.getDeclSpec().getAtomicSpecLoc());
10459 D.setInvalidType();
10460 }
10461 }
10462
10463 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor);
10464
10465 // C++0x [class.dtor]p2:
10466 // A destructor shall not be declared with a ref-qualifier.
10467 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
10468 if (FTI.hasRefQualifier()) {
10469 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
10470 << FTI.RefQualifierIsLValueRef
10471 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
10472 D.setInvalidType();
10473 }
10474
10475 // Make sure we don't have any parameters.
10476 if (FTIHasNonVoidParameters(FTI)) {
10477 Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
10478
10479 // Delete the parameters.
10480 FTI.freeParams();
10481 D.setInvalidType();
10482 }
10483
10484 // Make sure the destructor isn't variadic.
10485 if (FTI.isVariadic) {
10486 Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
10487 D.setInvalidType();
10488 }
10489
10490 // Rebuild the function type "R" without any type qualifiers or
10491 // parameters (in case any of the errors above fired) and with
10492 // "void" as the return type, since destructors don't have return
10493 // types.
10494 if (!D.isInvalidType())
10495 return R;
10496
10497 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
10498 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
10499 EPI.Variadic = false;
10500 EPI.TypeQuals = Qualifiers();
10501 EPI.RefQualifier = RQ_None;
10502 return Context.getFunctionType(Context.VoidTy, None, EPI);
10503 }
10504
extendLeft(SourceRange & R,SourceRange Before)10505 static void extendLeft(SourceRange &R, SourceRange Before) {
10506 if (Before.isInvalid())
10507 return;
10508 R.setBegin(Before.getBegin());
10509 if (R.getEnd().isInvalid())
10510 R.setEnd(Before.getEnd());
10511 }
10512
extendRight(SourceRange & R,SourceRange After)10513 static void extendRight(SourceRange &R, SourceRange After) {
10514 if (After.isInvalid())
10515 return;
10516 if (R.getBegin().isInvalid())
10517 R.setBegin(After.getBegin());
10518 R.setEnd(After.getEnd());
10519 }
10520
10521 /// CheckConversionDeclarator - Called by ActOnDeclarator to check the
10522 /// well-formednes of the conversion function declarator @p D with
10523 /// type @p R. If there are any errors in the declarator, this routine
10524 /// will emit diagnostics and return true. Otherwise, it will return
10525 /// false. Either way, the type @p R will be updated to reflect a
10526 /// well-formed type for the conversion operator.
CheckConversionDeclarator(Declarator & D,QualType & R,StorageClass & SC)10527 void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
10528 StorageClass& SC) {
10529 // C++ [class.conv.fct]p1:
10530 // Neither parameter types nor return type can be specified. The
10531 // type of a conversion function (8.3.5) is "function taking no
10532 // parameter returning conversion-type-id."
10533 if (SC == SC_Static) {
10534 if (!D.isInvalidType())
10535 Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
10536 << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10537 << D.getName().getSourceRange();
10538 D.setInvalidType();
10539 SC = SC_None;
10540 }
10541
10542 TypeSourceInfo *ConvTSI = nullptr;
10543 QualType ConvType =
10544 GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI);
10545
10546 const DeclSpec &DS = D.getDeclSpec();
10547 if (DS.hasTypeSpecifier() && !D.isInvalidType()) {
10548 // Conversion functions don't have return types, but the parser will
10549 // happily parse something like:
10550 //
10551 // class X {
10552 // float operator bool();
10553 // };
10554 //
10555 // The return type will be changed later anyway.
10556 Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
10557 << SourceRange(DS.getTypeSpecTypeLoc())
10558 << SourceRange(D.getIdentifierLoc());
10559 D.setInvalidType();
10560 } else if (DS.getTypeQualifiers() && !D.isInvalidType()) {
10561 // It's also plausible that the user writes type qualifiers in the wrong
10562 // place, such as:
10563 // struct S { const operator int(); };
10564 // FIXME: we could provide a fixit to move the qualifiers onto the
10565 // conversion type.
10566 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
10567 << SourceRange(D.getIdentifierLoc()) << 0;
10568 D.setInvalidType();
10569 }
10570
10571 const auto *Proto = R->castAs<FunctionProtoType>();
10572
10573 // Make sure we don't have any parameters.
10574 if (Proto->getNumParams() > 0) {
10575 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
10576
10577 // Delete the parameters.
10578 D.getFunctionTypeInfo().freeParams();
10579 D.setInvalidType();
10580 } else if (Proto->isVariadic()) {
10581 Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
10582 D.setInvalidType();
10583 }
10584
10585 // Diagnose "&operator bool()" and other such nonsense. This
10586 // is actually a gcc extension which we don't support.
10587 if (Proto->getReturnType() != ConvType) {
10588 bool NeedsTypedef = false;
10589 SourceRange Before, After;
10590
10591 // Walk the chunks and extract information on them for our diagnostic.
10592 bool PastFunctionChunk = false;
10593 for (auto &Chunk : D.type_objects()) {
10594 switch (Chunk.Kind) {
10595 case DeclaratorChunk::Function:
10596 if (!PastFunctionChunk) {
10597 if (Chunk.Fun.HasTrailingReturnType) {
10598 TypeSourceInfo *TRT = nullptr;
10599 GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT);
10600 if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange());
10601 }
10602 PastFunctionChunk = true;
10603 break;
10604 }
10605 LLVM_FALLTHROUGH;
10606 case DeclaratorChunk::Array:
10607 NeedsTypedef = true;
10608 extendRight(After, Chunk.getSourceRange());
10609 break;
10610
10611 case DeclaratorChunk::Pointer:
10612 case DeclaratorChunk::BlockPointer:
10613 case DeclaratorChunk::Reference:
10614 case DeclaratorChunk::MemberPointer:
10615 case DeclaratorChunk::Pipe:
10616 extendLeft(Before, Chunk.getSourceRange());
10617 break;
10618
10619 case DeclaratorChunk::Paren:
10620 extendLeft(Before, Chunk.Loc);
10621 extendRight(After, Chunk.EndLoc);
10622 break;
10623 }
10624 }
10625
10626 SourceLocation Loc = Before.isValid() ? Before.getBegin() :
10627 After.isValid() ? After.getBegin() :
10628 D.getIdentifierLoc();
10629 auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl);
10630 DB << Before << After;
10631
10632 if (!NeedsTypedef) {
10633 DB << /*don't need a typedef*/0;
10634
10635 // If we can provide a correct fix-it hint, do so.
10636 if (After.isInvalid() && ConvTSI) {
10637 SourceLocation InsertLoc =
10638 getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc());
10639 DB << FixItHint::CreateInsertion(InsertLoc, " ")
10640 << FixItHint::CreateInsertionFromRange(
10641 InsertLoc, CharSourceRange::getTokenRange(Before))
10642 << FixItHint::CreateRemoval(Before);
10643 }
10644 } else if (!Proto->getReturnType()->isDependentType()) {
10645 DB << /*typedef*/1 << Proto->getReturnType();
10646 } else if (getLangOpts().CPlusPlus11) {
10647 DB << /*alias template*/2 << Proto->getReturnType();
10648 } else {
10649 DB << /*might not be fixable*/3;
10650 }
10651
10652 // Recover by incorporating the other type chunks into the result type.
10653 // Note, this does *not* change the name of the function. This is compatible
10654 // with the GCC extension:
10655 // struct S { &operator int(); } s;
10656 // int &r = s.operator int(); // ok in GCC
10657 // S::operator int&() {} // error in GCC, function name is 'operator int'.
10658 ConvType = Proto->getReturnType();
10659 }
10660
10661 // C++ [class.conv.fct]p4:
10662 // The conversion-type-id shall not represent a function type nor
10663 // an array type.
10664 if (ConvType->isArrayType()) {
10665 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
10666 ConvType = Context.getPointerType(ConvType);
10667 D.setInvalidType();
10668 } else if (ConvType->isFunctionType()) {
10669 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
10670 ConvType = Context.getPointerType(ConvType);
10671 D.setInvalidType();
10672 }
10673
10674 // Rebuild the function type "R" without any parameters (in case any
10675 // of the errors above fired) and with the conversion type as the
10676 // return type.
10677 if (D.isInvalidType())
10678 R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo());
10679
10680 // C++0x explicit conversion operators.
10681 if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus20)
10682 Diag(DS.getExplicitSpecLoc(),
10683 getLangOpts().CPlusPlus11
10684 ? diag::warn_cxx98_compat_explicit_conversion_functions
10685 : diag::ext_explicit_conversion_functions)
10686 << SourceRange(DS.getExplicitSpecRange());
10687 }
10688
10689 /// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
10690 /// the declaration of the given C++ conversion function. This routine
10691 /// is responsible for recording the conversion function in the C++
10692 /// class, if possible.
ActOnConversionDeclarator(CXXConversionDecl * Conversion)10693 Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
10694 assert(Conversion && "Expected to receive a conversion function declaration");
10695
10696 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
10697
10698 // Make sure we aren't redeclaring the conversion function.
10699 QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
10700 // C++ [class.conv.fct]p1:
10701 // [...] A conversion function is never used to convert a
10702 // (possibly cv-qualified) object to the (possibly cv-qualified)
10703 // same object type (or a reference to it), to a (possibly
10704 // cv-qualified) base class of that type (or a reference to it),
10705 // or to (possibly cv-qualified) void.
10706 QualType ClassType
10707 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
10708 if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
10709 ConvType = ConvTypeRef->getPointeeType();
10710 if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
10711 Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
10712 /* Suppress diagnostics for instantiations. */;
10713 else if (Conversion->size_overridden_methods() != 0)
10714 /* Suppress diagnostics for overriding virtual function in a base class. */;
10715 else if (ConvType->isRecordType()) {
10716 ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
10717 if (ConvType == ClassType)
10718 Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
10719 << ClassType;
10720 else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType))
10721 Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
10722 << ClassType << ConvType;
10723 } else if (ConvType->isVoidType()) {
10724 Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
10725 << ClassType << ConvType;
10726 }
10727
10728 if (FunctionTemplateDecl *ConversionTemplate
10729 = Conversion->getDescribedFunctionTemplate())
10730 return ConversionTemplate;
10731
10732 return Conversion;
10733 }
10734
10735 namespace {
10736 /// Utility class to accumulate and print a diagnostic listing the invalid
10737 /// specifier(s) on a declaration.
10738 struct BadSpecifierDiagnoser {
BadSpecifierDiagnoser__anonb2a824812b11::BadSpecifierDiagnoser10739 BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID)
10740 : S(S), Diagnostic(S.Diag(Loc, DiagID)) {}
~BadSpecifierDiagnoser__anonb2a824812b11::BadSpecifierDiagnoser10741 ~BadSpecifierDiagnoser() {
10742 Diagnostic << Specifiers;
10743 }
10744
check__anonb2a824812b11::BadSpecifierDiagnoser10745 template<typename T> void check(SourceLocation SpecLoc, T Spec) {
10746 return check(SpecLoc, DeclSpec::getSpecifierName(Spec));
10747 }
check__anonb2a824812b11::BadSpecifierDiagnoser10748 void check(SourceLocation SpecLoc, DeclSpec::TST Spec) {
10749 return check(SpecLoc,
10750 DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy()));
10751 }
check__anonb2a824812b11::BadSpecifierDiagnoser10752 void check(SourceLocation SpecLoc, const char *Spec) {
10753 if (SpecLoc.isInvalid()) return;
10754 Diagnostic << SourceRange(SpecLoc, SpecLoc);
10755 if (!Specifiers.empty()) Specifiers += " ";
10756 Specifiers += Spec;
10757 }
10758
10759 Sema &S;
10760 Sema::SemaDiagnosticBuilder Diagnostic;
10761 std::string Specifiers;
10762 };
10763 }
10764
10765 /// Check the validity of a declarator that we parsed for a deduction-guide.
10766 /// These aren't actually declarators in the grammar, so we need to check that
10767 /// the user didn't specify any pieces that are not part of the deduction-guide
10768 /// grammar.
CheckDeductionGuideDeclarator(Declarator & D,QualType & R,StorageClass & SC)10769 void Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
10770 StorageClass &SC) {
10771 TemplateName GuidedTemplate = D.getName().TemplateName.get().get();
10772 TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl();
10773 assert(GuidedTemplateDecl && "missing template decl for deduction guide");
10774
10775 // C++ [temp.deduct.guide]p3:
10776 // A deduction-gide shall be declared in the same scope as the
10777 // corresponding class template.
10778 if (!CurContext->getRedeclContext()->Equals(
10779 GuidedTemplateDecl->getDeclContext()->getRedeclContext())) {
10780 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope)
10781 << GuidedTemplateDecl;
10782 Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here);
10783 }
10784
10785 auto &DS = D.getMutableDeclSpec();
10786 // We leave 'friend' and 'virtual' to be rejected in the normal way.
10787 if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() ||
10788 DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() ||
10789 DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) {
10790 BadSpecifierDiagnoser Diagnoser(
10791 *this, D.getIdentifierLoc(),
10792 diag::err_deduction_guide_invalid_specifier);
10793
10794 Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec());
10795 DS.ClearStorageClassSpecs();
10796 SC = SC_None;
10797
10798 // 'explicit' is permitted.
10799 Diagnoser.check(DS.getInlineSpecLoc(), "inline");
10800 Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn");
10801 Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr");
10802 DS.ClearConstexprSpec();
10803
10804 Diagnoser.check(DS.getConstSpecLoc(), "const");
10805 Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict");
10806 Diagnoser.check(DS.getVolatileSpecLoc(), "volatile");
10807 Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic");
10808 Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned");
10809 DS.ClearTypeQualifiers();
10810
10811 Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex());
10812 Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign());
10813 Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth());
10814 Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType());
10815 DS.ClearTypeSpecType();
10816 }
10817
10818 if (D.isInvalidType())
10819 return;
10820
10821 // Check the declarator is simple enough.
10822 bool FoundFunction = false;
10823 for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) {
10824 if (Chunk.Kind == DeclaratorChunk::Paren)
10825 continue;
10826 if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) {
10827 Diag(D.getDeclSpec().getBeginLoc(),
10828 diag::err_deduction_guide_with_complex_decl)
10829 << D.getSourceRange();
10830 break;
10831 }
10832 if (!Chunk.Fun.hasTrailingReturnType()) {
10833 Diag(D.getName().getBeginLoc(),
10834 diag::err_deduction_guide_no_trailing_return_type);
10835 break;
10836 }
10837
10838 // Check that the return type is written as a specialization of
10839 // the template specified as the deduction-guide's name.
10840 ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType();
10841 TypeSourceInfo *TSI = nullptr;
10842 QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI);
10843 assert(TSI && "deduction guide has valid type but invalid return type?");
10844 bool AcceptableReturnType = false;
10845 bool MightInstantiateToSpecialization = false;
10846 if (auto RetTST =
10847 TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>()) {
10848 TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName();
10849 bool TemplateMatches =
10850 Context.hasSameTemplateName(SpecifiedName, GuidedTemplate);
10851 if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches)
10852 AcceptableReturnType = true;
10853 else {
10854 // This could still instantiate to the right type, unless we know it
10855 // names the wrong class template.
10856 auto *TD = SpecifiedName.getAsTemplateDecl();
10857 MightInstantiateToSpecialization = !(TD && isa<ClassTemplateDecl>(TD) &&
10858 !TemplateMatches);
10859 }
10860 } else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) {
10861 MightInstantiateToSpecialization = true;
10862 }
10863
10864 if (!AcceptableReturnType) {
10865 Diag(TSI->getTypeLoc().getBeginLoc(),
10866 diag::err_deduction_guide_bad_trailing_return_type)
10867 << GuidedTemplate << TSI->getType()
10868 << MightInstantiateToSpecialization
10869 << TSI->getTypeLoc().getSourceRange();
10870 }
10871
10872 // Keep going to check that we don't have any inner declarator pieces (we
10873 // could still have a function returning a pointer to a function).
10874 FoundFunction = true;
10875 }
10876
10877 if (D.isFunctionDefinition())
10878 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function);
10879 }
10880
10881 //===----------------------------------------------------------------------===//
10882 // Namespace Handling
10883 //===----------------------------------------------------------------------===//
10884
10885 /// Diagnose a mismatch in 'inline' qualifiers when a namespace is
10886 /// reopened.
DiagnoseNamespaceInlineMismatch(Sema & S,SourceLocation KeywordLoc,SourceLocation Loc,IdentifierInfo * II,bool * IsInline,NamespaceDecl * PrevNS)10887 static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc,
10888 SourceLocation Loc,
10889 IdentifierInfo *II, bool *IsInline,
10890 NamespaceDecl *PrevNS) {
10891 assert(*IsInline != PrevNS->isInline());
10892
10893 if (PrevNS->isInline())
10894 // The user probably just forgot the 'inline', so suggest that it
10895 // be added back.
10896 S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
10897 << FixItHint::CreateInsertion(KeywordLoc, "inline ");
10898 else
10899 S.Diag(Loc, diag::err_inline_namespace_mismatch);
10900
10901 S.Diag(PrevNS->getLocation(), diag::note_previous_definition);
10902 *IsInline = PrevNS->isInline();
10903 }
10904
10905 /// ActOnStartNamespaceDef - This is called at the start of a namespace
10906 /// definition.
ActOnStartNamespaceDef(Scope * NamespcScope,SourceLocation InlineLoc,SourceLocation NamespaceLoc,SourceLocation IdentLoc,IdentifierInfo * II,SourceLocation LBrace,const ParsedAttributesView & AttrList,UsingDirectiveDecl * & UD)10907 Decl *Sema::ActOnStartNamespaceDef(
10908 Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc,
10909 SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace,
10910 const ParsedAttributesView &AttrList, UsingDirectiveDecl *&UD) {
10911 SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
10912 // For anonymous namespace, take the location of the left brace.
10913 SourceLocation Loc = II ? IdentLoc : LBrace;
10914 bool IsInline = InlineLoc.isValid();
10915 bool IsInvalid = false;
10916 bool IsStd = false;
10917 bool AddToKnown = false;
10918 Scope *DeclRegionScope = NamespcScope->getParent();
10919
10920 NamespaceDecl *PrevNS = nullptr;
10921 if (II) {
10922 // C++ [namespace.def]p2:
10923 // The identifier in an original-namespace-definition shall not
10924 // have been previously defined in the declarative region in
10925 // which the original-namespace-definition appears. The
10926 // identifier in an original-namespace-definition is the name of
10927 // the namespace. Subsequently in that declarative region, it is
10928 // treated as an original-namespace-name.
10929 //
10930 // Since namespace names are unique in their scope, and we don't
10931 // look through using directives, just look for any ordinary names
10932 // as if by qualified name lookup.
10933 LookupResult R(*this, II, IdentLoc, LookupOrdinaryName,
10934 ForExternalRedeclaration);
10935 LookupQualifiedName(R, CurContext->getRedeclContext());
10936 NamedDecl *PrevDecl =
10937 R.isSingleResult() ? R.getRepresentativeDecl() : nullptr;
10938 PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
10939
10940 if (PrevNS) {
10941 // This is an extended namespace definition.
10942 if (IsInline != PrevNS->isInline())
10943 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II,
10944 &IsInline, PrevNS);
10945 } else if (PrevDecl) {
10946 // This is an invalid name redefinition.
10947 Diag(Loc, diag::err_redefinition_different_kind)
10948 << II;
10949 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
10950 IsInvalid = true;
10951 // Continue on to push Namespc as current DeclContext and return it.
10952 } else if (II->isStr("std") &&
10953 CurContext->getRedeclContext()->isTranslationUnit()) {
10954 // This is the first "real" definition of the namespace "std", so update
10955 // our cache of the "std" namespace to point at this definition.
10956 PrevNS = getStdNamespace();
10957 IsStd = true;
10958 AddToKnown = !IsInline;
10959 } else {
10960 // We've seen this namespace for the first time.
10961 AddToKnown = !IsInline;
10962 }
10963 } else {
10964 // Anonymous namespaces.
10965
10966 // Determine whether the parent already has an anonymous namespace.
10967 DeclContext *Parent = CurContext->getRedeclContext();
10968 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
10969 PrevNS = TU->getAnonymousNamespace();
10970 } else {
10971 NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
10972 PrevNS = ND->getAnonymousNamespace();
10973 }
10974
10975 if (PrevNS && IsInline != PrevNS->isInline())
10976 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II,
10977 &IsInline, PrevNS);
10978 }
10979
10980 NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
10981 StartLoc, Loc, II, PrevNS);
10982 if (IsInvalid)
10983 Namespc->setInvalidDecl();
10984
10985 ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
10986 AddPragmaAttributes(DeclRegionScope, Namespc);
10987
10988 // FIXME: Should we be merging attributes?
10989 if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
10990 PushNamespaceVisibilityAttr(Attr, Loc);
10991
10992 if (IsStd)
10993 StdNamespace = Namespc;
10994 if (AddToKnown)
10995 KnownNamespaces[Namespc] = false;
10996
10997 if (II) {
10998 PushOnScopeChains(Namespc, DeclRegionScope);
10999 } else {
11000 // Link the anonymous namespace into its parent.
11001 DeclContext *Parent = CurContext->getRedeclContext();
11002 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
11003 TU->setAnonymousNamespace(Namespc);
11004 } else {
11005 cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
11006 }
11007
11008 CurContext->addDecl(Namespc);
11009
11010 // C++ [namespace.unnamed]p1. An unnamed-namespace-definition
11011 // behaves as if it were replaced by
11012 // namespace unique { /* empty body */ }
11013 // using namespace unique;
11014 // namespace unique { namespace-body }
11015 // where all occurrences of 'unique' in a translation unit are
11016 // replaced by the same identifier and this identifier differs
11017 // from all other identifiers in the entire program.
11018
11019 // We just create the namespace with an empty name and then add an
11020 // implicit using declaration, just like the standard suggests.
11021 //
11022 // CodeGen enforces the "universally unique" aspect by giving all
11023 // declarations semantically contained within an anonymous
11024 // namespace internal linkage.
11025
11026 if (!PrevNS) {
11027 UD = UsingDirectiveDecl::Create(Context, Parent,
11028 /* 'using' */ LBrace,
11029 /* 'namespace' */ SourceLocation(),
11030 /* qualifier */ NestedNameSpecifierLoc(),
11031 /* identifier */ SourceLocation(),
11032 Namespc,
11033 /* Ancestor */ Parent);
11034 UD->setImplicit();
11035 Parent->addDecl(UD);
11036 }
11037 }
11038
11039 ActOnDocumentableDecl(Namespc);
11040
11041 // Although we could have an invalid decl (i.e. the namespace name is a
11042 // redefinition), push it as current DeclContext and try to continue parsing.
11043 // FIXME: We should be able to push Namespc here, so that the each DeclContext
11044 // for the namespace has the declarations that showed up in that particular
11045 // namespace definition.
11046 PushDeclContext(NamespcScope, Namespc);
11047 return Namespc;
11048 }
11049
11050 /// getNamespaceDecl - Returns the namespace a decl represents. If the decl
11051 /// is a namespace alias, returns the namespace it points to.
getNamespaceDecl(NamedDecl * D)11052 static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
11053 if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
11054 return AD->getNamespace();
11055 return dyn_cast_or_null<NamespaceDecl>(D);
11056 }
11057
11058 /// ActOnFinishNamespaceDef - This callback is called after a namespace is
11059 /// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
ActOnFinishNamespaceDef(Decl * Dcl,SourceLocation RBrace)11060 void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
11061 NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
11062 assert(Namespc && "Invalid parameter, expected NamespaceDecl");
11063 Namespc->setRBraceLoc(RBrace);
11064 PopDeclContext();
11065 if (Namespc->hasAttr<VisibilityAttr>())
11066 PopPragmaVisibility(true, RBrace);
11067 // If this namespace contains an export-declaration, export it now.
11068 if (DeferredExportedNamespaces.erase(Namespc))
11069 Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
11070 }
11071
getStdBadAlloc() const11072 CXXRecordDecl *Sema::getStdBadAlloc() const {
11073 return cast_or_null<CXXRecordDecl>(
11074 StdBadAlloc.get(Context.getExternalSource()));
11075 }
11076
getStdAlignValT() const11077 EnumDecl *Sema::getStdAlignValT() const {
11078 return cast_or_null<EnumDecl>(StdAlignValT.get(Context.getExternalSource()));
11079 }
11080
getStdNamespace() const11081 NamespaceDecl *Sema::getStdNamespace() const {
11082 return cast_or_null<NamespaceDecl>(
11083 StdNamespace.get(Context.getExternalSource()));
11084 }
11085
lookupStdExperimentalNamespace()11086 NamespaceDecl *Sema::lookupStdExperimentalNamespace() {
11087 if (!StdExperimentalNamespaceCache) {
11088 if (auto Std = getStdNamespace()) {
11089 LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"),
11090 SourceLocation(), LookupNamespaceName);
11091 if (!LookupQualifiedName(Result, Std) ||
11092 !(StdExperimentalNamespaceCache =
11093 Result.getAsSingle<NamespaceDecl>()))
11094 Result.suppressDiagnostics();
11095 }
11096 }
11097 return StdExperimentalNamespaceCache;
11098 }
11099
11100 namespace {
11101
11102 enum UnsupportedSTLSelect {
11103 USS_InvalidMember,
11104 USS_MissingMember,
11105 USS_NonTrivial,
11106 USS_Other
11107 };
11108
11109 struct InvalidSTLDiagnoser {
11110 Sema &S;
11111 SourceLocation Loc;
11112 QualType TyForDiags;
11113
operator ()__anonb2a824812c11::InvalidSTLDiagnoser11114 QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "",
11115 const VarDecl *VD = nullptr) {
11116 {
11117 auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported)
11118 << TyForDiags << ((int)Sel);
11119 if (Sel == USS_InvalidMember || Sel == USS_MissingMember) {
11120 assert(!Name.empty());
11121 D << Name;
11122 }
11123 }
11124 if (Sel == USS_InvalidMember) {
11125 S.Diag(VD->getLocation(), diag::note_var_declared_here)
11126 << VD << VD->getSourceRange();
11127 }
11128 return QualType();
11129 }
11130 };
11131 } // namespace
11132
CheckComparisonCategoryType(ComparisonCategoryType Kind,SourceLocation Loc,ComparisonCategoryUsage Usage)11133 QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind,
11134 SourceLocation Loc,
11135 ComparisonCategoryUsage Usage) {
11136 assert(getLangOpts().CPlusPlus &&
11137 "Looking for comparison category type outside of C++.");
11138
11139 // Use an elaborated type for diagnostics which has a name containing the
11140 // prepended 'std' namespace but not any inline namespace names.
11141 auto TyForDiags = [&](ComparisonCategoryInfo *Info) {
11142 auto *NNS =
11143 NestedNameSpecifier::Create(Context, nullptr, getStdNamespace());
11144 return Context.getElaboratedType(ETK_None, NNS, Info->getType());
11145 };
11146
11147 // Check if we've already successfully checked the comparison category type
11148 // before. If so, skip checking it again.
11149 ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind);
11150 if (Info && FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)]) {
11151 // The only thing we need to check is that the type has a reachable
11152 // definition in the current context.
11153 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
11154 return QualType();
11155
11156 return Info->getType();
11157 }
11158
11159 // If lookup failed
11160 if (!Info) {
11161 std::string NameForDiags = "std::";
11162 NameForDiags += ComparisonCategories::getCategoryString(Kind);
11163 Diag(Loc, diag::err_implied_comparison_category_type_not_found)
11164 << NameForDiags << (int)Usage;
11165 return QualType();
11166 }
11167
11168 assert(Info->Kind == Kind);
11169 assert(Info->Record);
11170
11171 // Update the Record decl in case we encountered a forward declaration on our
11172 // first pass. FIXME: This is a bit of a hack.
11173 if (Info->Record->hasDefinition())
11174 Info->Record = Info->Record->getDefinition();
11175
11176 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
11177 return QualType();
11178
11179 InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags(Info)};
11180
11181 if (!Info->Record->isTriviallyCopyable())
11182 return UnsupportedSTLError(USS_NonTrivial);
11183
11184 for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) {
11185 CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl();
11186 // Tolerate empty base classes.
11187 if (Base->isEmpty())
11188 continue;
11189 // Reject STL implementations which have at least one non-empty base.
11190 return UnsupportedSTLError();
11191 }
11192
11193 // Check that the STL has implemented the types using a single integer field.
11194 // This expectation allows better codegen for builtin operators. We require:
11195 // (1) The class has exactly one field.
11196 // (2) The field is an integral or enumeration type.
11197 auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end();
11198 if (std::distance(FIt, FEnd) != 1 ||
11199 !FIt->getType()->isIntegralOrEnumerationType()) {
11200 return UnsupportedSTLError();
11201 }
11202
11203 // Build each of the require values and store them in Info.
11204 for (ComparisonCategoryResult CCR :
11205 ComparisonCategories::getPossibleResultsForType(Kind)) {
11206 StringRef MemName = ComparisonCategories::getResultString(CCR);
11207 ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR);
11208
11209 if (!ValInfo)
11210 return UnsupportedSTLError(USS_MissingMember, MemName);
11211
11212 VarDecl *VD = ValInfo->VD;
11213 assert(VD && "should not be null!");
11214
11215 // Attempt to diagnose reasons why the STL definition of this type
11216 // might be foobar, including it failing to be a constant expression.
11217 // TODO Handle more ways the lookup or result can be invalid.
11218 if (!VD->isStaticDataMember() ||
11219 !VD->isUsableInConstantExpressions(Context))
11220 return UnsupportedSTLError(USS_InvalidMember, MemName, VD);
11221
11222 // Attempt to evaluate the var decl as a constant expression and extract
11223 // the value of its first field as a ICE. If this fails, the STL
11224 // implementation is not supported.
11225 if (!ValInfo->hasValidIntValue())
11226 return UnsupportedSTLError();
11227
11228 MarkVariableReferenced(Loc, VD);
11229 }
11230
11231 // We've successfully built the required types and expressions. Update
11232 // the cache and return the newly cached value.
11233 FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)] = true;
11234 return Info->getType();
11235 }
11236
11237 /// Retrieve the special "std" namespace, which may require us to
11238 /// implicitly define the namespace.
getOrCreateStdNamespace()11239 NamespaceDecl *Sema::getOrCreateStdNamespace() {
11240 if (!StdNamespace) {
11241 // The "std" namespace has not yet been defined, so build one implicitly.
11242 StdNamespace = NamespaceDecl::Create(Context,
11243 Context.getTranslationUnitDecl(),
11244 /*Inline=*/false,
11245 SourceLocation(), SourceLocation(),
11246 &PP.getIdentifierTable().get("std"),
11247 /*PrevDecl=*/nullptr);
11248 getStdNamespace()->setImplicit(true);
11249 }
11250
11251 return getStdNamespace();
11252 }
11253
isStdInitializerList(QualType Ty,QualType * Element)11254 bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
11255 assert(getLangOpts().CPlusPlus &&
11256 "Looking for std::initializer_list outside of C++.");
11257
11258 // We're looking for implicit instantiations of
11259 // template <typename E> class std::initializer_list.
11260
11261 if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
11262 return false;
11263
11264 ClassTemplateDecl *Template = nullptr;
11265 const TemplateArgument *Arguments = nullptr;
11266
11267 if (const RecordType *RT = Ty->getAs<RecordType>()) {
11268
11269 ClassTemplateSpecializationDecl *Specialization =
11270 dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
11271 if (!Specialization)
11272 return false;
11273
11274 Template = Specialization->getSpecializedTemplate();
11275 Arguments = Specialization->getTemplateArgs().data();
11276 } else if (const TemplateSpecializationType *TST =
11277 Ty->getAs<TemplateSpecializationType>()) {
11278 Template = dyn_cast_or_null<ClassTemplateDecl>(
11279 TST->getTemplateName().getAsTemplateDecl());
11280 Arguments = TST->getArgs();
11281 }
11282 if (!Template)
11283 return false;
11284
11285 if (!StdInitializerList) {
11286 // Haven't recognized std::initializer_list yet, maybe this is it.
11287 CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
11288 if (TemplateClass->getIdentifier() !=
11289 &PP.getIdentifierTable().get("initializer_list") ||
11290 !getStdNamespace()->InEnclosingNamespaceSetOf(
11291 TemplateClass->getDeclContext()))
11292 return false;
11293 // This is a template called std::initializer_list, but is it the right
11294 // template?
11295 TemplateParameterList *Params = Template->getTemplateParameters();
11296 if (Params->getMinRequiredArguments() != 1)
11297 return false;
11298 if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
11299 return false;
11300
11301 // It's the right template.
11302 StdInitializerList = Template;
11303 }
11304
11305 if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl())
11306 return false;
11307
11308 // This is an instance of std::initializer_list. Find the argument type.
11309 if (Element)
11310 *Element = Arguments[0].getAsType();
11311 return true;
11312 }
11313
LookupStdInitializerList(Sema & S,SourceLocation Loc)11314 static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
11315 NamespaceDecl *Std = S.getStdNamespace();
11316 if (!Std) {
11317 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
11318 return nullptr;
11319 }
11320
11321 LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
11322 Loc, Sema::LookupOrdinaryName);
11323 if (!S.LookupQualifiedName(Result, Std)) {
11324 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
11325 return nullptr;
11326 }
11327 ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
11328 if (!Template) {
11329 Result.suppressDiagnostics();
11330 // We found something weird. Complain about the first thing we found.
11331 NamedDecl *Found = *Result.begin();
11332 S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
11333 return nullptr;
11334 }
11335
11336 // We found some template called std::initializer_list. Now verify that it's
11337 // correct.
11338 TemplateParameterList *Params = Template->getTemplateParameters();
11339 if (Params->getMinRequiredArguments() != 1 ||
11340 !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
11341 S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
11342 return nullptr;
11343 }
11344
11345 return Template;
11346 }
11347
BuildStdInitializerList(QualType Element,SourceLocation Loc)11348 QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
11349 if (!StdInitializerList) {
11350 StdInitializerList = LookupStdInitializerList(*this, Loc);
11351 if (!StdInitializerList)
11352 return QualType();
11353 }
11354
11355 TemplateArgumentListInfo Args(Loc, Loc);
11356 Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
11357 Context.getTrivialTypeSourceInfo(Element,
11358 Loc)));
11359 return Context.getCanonicalType(
11360 CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
11361 }
11362
isInitListConstructor(const FunctionDecl * Ctor)11363 bool Sema::isInitListConstructor(const FunctionDecl *Ctor) {
11364 // C++ [dcl.init.list]p2:
11365 // A constructor is an initializer-list constructor if its first parameter
11366 // is of type std::initializer_list<E> or reference to possibly cv-qualified
11367 // std::initializer_list<E> for some type E, and either there are no other
11368 // parameters or else all other parameters have default arguments.
11369 if (!Ctor->hasOneParamOrDefaultArgs())
11370 return false;
11371
11372 QualType ArgType = Ctor->getParamDecl(0)->getType();
11373 if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
11374 ArgType = RT->getPointeeType().getUnqualifiedType();
11375
11376 return isStdInitializerList(ArgType, nullptr);
11377 }
11378
11379 /// Determine whether a using statement is in a context where it will be
11380 /// apply in all contexts.
IsUsingDirectiveInToplevelContext(DeclContext * CurContext)11381 static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
11382 switch (CurContext->getDeclKind()) {
11383 case Decl::TranslationUnit:
11384 return true;
11385 case Decl::LinkageSpec:
11386 return IsUsingDirectiveInToplevelContext(CurContext->getParent());
11387 default:
11388 return false;
11389 }
11390 }
11391
11392 namespace {
11393
11394 // Callback to only accept typo corrections that are namespaces.
11395 class NamespaceValidatorCCC final : public CorrectionCandidateCallback {
11396 public:
ValidateCandidate(const TypoCorrection & candidate)11397 bool ValidateCandidate(const TypoCorrection &candidate) override {
11398 if (NamedDecl *ND = candidate.getCorrectionDecl())
11399 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
11400 return false;
11401 }
11402
clone()11403 std::unique_ptr<CorrectionCandidateCallback> clone() override {
11404 return std::make_unique<NamespaceValidatorCCC>(*this);
11405 }
11406 };
11407
11408 }
11409
TryNamespaceTypoCorrection(Sema & S,LookupResult & R,Scope * Sc,CXXScopeSpec & SS,SourceLocation IdentLoc,IdentifierInfo * Ident)11410 static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
11411 CXXScopeSpec &SS,
11412 SourceLocation IdentLoc,
11413 IdentifierInfo *Ident) {
11414 R.clear();
11415 NamespaceValidatorCCC CCC{};
11416 if (TypoCorrection Corrected =
11417 S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC,
11418 Sema::CTK_ErrorRecovery)) {
11419 if (DeclContext *DC = S.computeDeclContext(SS, false)) {
11420 std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
11421 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
11422 Ident->getName().equals(CorrectedStr);
11423 S.diagnoseTypo(Corrected,
11424 S.PDiag(diag::err_using_directive_member_suggest)
11425 << Ident << DC << DroppedSpecifier << SS.getRange(),
11426 S.PDiag(diag::note_namespace_defined_here));
11427 } else {
11428 S.diagnoseTypo(Corrected,
11429 S.PDiag(diag::err_using_directive_suggest) << Ident,
11430 S.PDiag(diag::note_namespace_defined_here));
11431 }
11432 R.addDecl(Corrected.getFoundDecl());
11433 return true;
11434 }
11435 return false;
11436 }
11437
ActOnUsingDirective(Scope * S,SourceLocation UsingLoc,SourceLocation NamespcLoc,CXXScopeSpec & SS,SourceLocation IdentLoc,IdentifierInfo * NamespcName,const ParsedAttributesView & AttrList)11438 Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc,
11439 SourceLocation NamespcLoc, CXXScopeSpec &SS,
11440 SourceLocation IdentLoc,
11441 IdentifierInfo *NamespcName,
11442 const ParsedAttributesView &AttrList) {
11443 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
11444 assert(NamespcName && "Invalid NamespcName.");
11445 assert(IdentLoc.isValid() && "Invalid NamespceName location.");
11446
11447 // This can only happen along a recovery path.
11448 while (S->isTemplateParamScope())
11449 S = S->getParent();
11450 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
11451
11452 UsingDirectiveDecl *UDir = nullptr;
11453 NestedNameSpecifier *Qualifier = nullptr;
11454 if (SS.isSet())
11455 Qualifier = SS.getScopeRep();
11456
11457 // Lookup namespace name.
11458 LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
11459 LookupParsedName(R, S, &SS);
11460 if (R.isAmbiguous())
11461 return nullptr;
11462
11463 if (R.empty()) {
11464 R.clear();
11465 // Allow "using namespace std;" or "using namespace ::std;" even if
11466 // "std" hasn't been defined yet, for GCC compatibility.
11467 if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
11468 NamespcName->isStr("std")) {
11469 Diag(IdentLoc, diag::ext_using_undefined_std);
11470 R.addDecl(getOrCreateStdNamespace());
11471 R.resolveKind();
11472 }
11473 // Otherwise, attempt typo correction.
11474 else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
11475 }
11476
11477 if (!R.empty()) {
11478 NamedDecl *Named = R.getRepresentativeDecl();
11479 NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>();
11480 assert(NS && "expected namespace decl");
11481
11482 // The use of a nested name specifier may trigger deprecation warnings.
11483 DiagnoseUseOfDecl(Named, IdentLoc);
11484
11485 // C++ [namespace.udir]p1:
11486 // A using-directive specifies that the names in the nominated
11487 // namespace can be used in the scope in which the
11488 // using-directive appears after the using-directive. During
11489 // unqualified name lookup (3.4.1), the names appear as if they
11490 // were declared in the nearest enclosing namespace which
11491 // contains both the using-directive and the nominated
11492 // namespace. [Note: in this context, "contains" means "contains
11493 // directly or indirectly". ]
11494
11495 // Find enclosing context containing both using-directive and
11496 // nominated namespace.
11497 DeclContext *CommonAncestor = NS;
11498 while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
11499 CommonAncestor = CommonAncestor->getParent();
11500
11501 UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
11502 SS.getWithLocInContext(Context),
11503 IdentLoc, Named, CommonAncestor);
11504
11505 if (IsUsingDirectiveInToplevelContext(CurContext) &&
11506 !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
11507 Diag(IdentLoc, diag::warn_using_directive_in_header);
11508 }
11509
11510 PushUsingDirective(S, UDir);
11511 } else {
11512 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
11513 }
11514
11515 if (UDir)
11516 ProcessDeclAttributeList(S, UDir, AttrList);
11517
11518 return UDir;
11519 }
11520
PushUsingDirective(Scope * S,UsingDirectiveDecl * UDir)11521 void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
11522 // If the scope has an associated entity and the using directive is at
11523 // namespace or translation unit scope, add the UsingDirectiveDecl into
11524 // its lookup structure so qualified name lookup can find it.
11525 DeclContext *Ctx = S->getEntity();
11526 if (Ctx && !Ctx->isFunctionOrMethod())
11527 Ctx->addDecl(UDir);
11528 else
11529 // Otherwise, it is at block scope. The using-directives will affect lookup
11530 // only to the end of the scope.
11531 S->PushUsingDirective(UDir);
11532 }
11533
ActOnUsingDeclaration(Scope * S,AccessSpecifier AS,SourceLocation UsingLoc,SourceLocation TypenameLoc,CXXScopeSpec & SS,UnqualifiedId & Name,SourceLocation EllipsisLoc,const ParsedAttributesView & AttrList)11534 Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS,
11535 SourceLocation UsingLoc,
11536 SourceLocation TypenameLoc, CXXScopeSpec &SS,
11537 UnqualifiedId &Name,
11538 SourceLocation EllipsisLoc,
11539 const ParsedAttributesView &AttrList) {
11540 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
11541
11542 if (SS.isEmpty()) {
11543 Diag(Name.getBeginLoc(), diag::err_using_requires_qualname);
11544 return nullptr;
11545 }
11546
11547 switch (Name.getKind()) {
11548 case UnqualifiedIdKind::IK_ImplicitSelfParam:
11549 case UnqualifiedIdKind::IK_Identifier:
11550 case UnqualifiedIdKind::IK_OperatorFunctionId:
11551 case UnqualifiedIdKind::IK_LiteralOperatorId:
11552 case UnqualifiedIdKind::IK_ConversionFunctionId:
11553 break;
11554
11555 case UnqualifiedIdKind::IK_ConstructorName:
11556 case UnqualifiedIdKind::IK_ConstructorTemplateId:
11557 // C++11 inheriting constructors.
11558 Diag(Name.getBeginLoc(),
11559 getLangOpts().CPlusPlus11
11560 ? diag::warn_cxx98_compat_using_decl_constructor
11561 : diag::err_using_decl_constructor)
11562 << SS.getRange();
11563
11564 if (getLangOpts().CPlusPlus11) break;
11565
11566 return nullptr;
11567
11568 case UnqualifiedIdKind::IK_DestructorName:
11569 Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange();
11570 return nullptr;
11571
11572 case UnqualifiedIdKind::IK_TemplateId:
11573 Diag(Name.getBeginLoc(), diag::err_using_decl_template_id)
11574 << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
11575 return nullptr;
11576
11577 case UnqualifiedIdKind::IK_DeductionGuideName:
11578 llvm_unreachable("cannot parse qualified deduction guide name");
11579 }
11580
11581 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
11582 DeclarationName TargetName = TargetNameInfo.getName();
11583 if (!TargetName)
11584 return nullptr;
11585
11586 // Warn about access declarations.
11587 if (UsingLoc.isInvalid()) {
11588 Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11
11589 ? diag::err_access_decl
11590 : diag::warn_access_decl_deprecated)
11591 << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
11592 }
11593
11594 if (EllipsisLoc.isInvalid()) {
11595 if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
11596 DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
11597 return nullptr;
11598 } else {
11599 if (!SS.getScopeRep()->containsUnexpandedParameterPack() &&
11600 !TargetNameInfo.containsUnexpandedParameterPack()) {
11601 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
11602 << SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc());
11603 EllipsisLoc = SourceLocation();
11604 }
11605 }
11606
11607 NamedDecl *UD =
11608 BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc,
11609 SS, TargetNameInfo, EllipsisLoc, AttrList,
11610 /*IsInstantiation*/false);
11611 if (UD)
11612 PushOnScopeChains(UD, S, /*AddToContext*/ false);
11613
11614 return UD;
11615 }
11616
11617 /// Determine whether a using declaration considers the given
11618 /// declarations as "equivalent", e.g., if they are redeclarations of
11619 /// the same entity or are both typedefs of the same type.
11620 static bool
IsEquivalentForUsingDecl(ASTContext & Context,NamedDecl * D1,NamedDecl * D2)11621 IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) {
11622 if (D1->getCanonicalDecl() == D2->getCanonicalDecl())
11623 return true;
11624
11625 if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
11626 if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2))
11627 return Context.hasSameType(TD1->getUnderlyingType(),
11628 TD2->getUnderlyingType());
11629
11630 return false;
11631 }
11632
11633
11634 /// Determines whether to create a using shadow decl for a particular
11635 /// decl, given the set of decls existing prior to this using lookup.
CheckUsingShadowDecl(UsingDecl * Using,NamedDecl * Orig,const LookupResult & Previous,UsingShadowDecl * & PrevShadow)11636 bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
11637 const LookupResult &Previous,
11638 UsingShadowDecl *&PrevShadow) {
11639 // Diagnose finding a decl which is not from a base class of the
11640 // current class. We do this now because there are cases where this
11641 // function will silently decide not to build a shadow decl, which
11642 // will pre-empt further diagnostics.
11643 //
11644 // We don't need to do this in C++11 because we do the check once on
11645 // the qualifier.
11646 //
11647 // FIXME: diagnose the following if we care enough:
11648 // struct A { int foo; };
11649 // struct B : A { using A::foo; };
11650 // template <class T> struct C : A {};
11651 // template <class T> struct D : C<T> { using B::foo; } // <---
11652 // This is invalid (during instantiation) in C++03 because B::foo
11653 // resolves to the using decl in B, which is not a base class of D<T>.
11654 // We can't diagnose it immediately because C<T> is an unknown
11655 // specialization. The UsingShadowDecl in D<T> then points directly
11656 // to A::foo, which will look well-formed when we instantiate.
11657 // The right solution is to not collapse the shadow-decl chain.
11658 if (!getLangOpts().CPlusPlus11 && CurContext->isRecord()) {
11659 DeclContext *OrigDC = Orig->getDeclContext();
11660
11661 // Handle enums and anonymous structs.
11662 if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
11663 CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
11664 while (OrigRec->isAnonymousStructOrUnion())
11665 OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
11666
11667 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
11668 if (OrigDC == CurContext) {
11669 Diag(Using->getLocation(),
11670 diag::err_using_decl_nested_name_specifier_is_current_class)
11671 << Using->getQualifierLoc().getSourceRange();
11672 Diag(Orig->getLocation(), diag::note_using_decl_target);
11673 Using->setInvalidDecl();
11674 return true;
11675 }
11676
11677 Diag(Using->getQualifierLoc().getBeginLoc(),
11678 diag::err_using_decl_nested_name_specifier_is_not_base_class)
11679 << Using->getQualifier()
11680 << cast<CXXRecordDecl>(CurContext)
11681 << Using->getQualifierLoc().getSourceRange();
11682 Diag(Orig->getLocation(), diag::note_using_decl_target);
11683 Using->setInvalidDecl();
11684 return true;
11685 }
11686 }
11687
11688 if (Previous.empty()) return false;
11689
11690 NamedDecl *Target = Orig;
11691 if (isa<UsingShadowDecl>(Target))
11692 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
11693
11694 // If the target happens to be one of the previous declarations, we
11695 // don't have a conflict.
11696 //
11697 // FIXME: but we might be increasing its access, in which case we
11698 // should redeclare it.
11699 NamedDecl *NonTag = nullptr, *Tag = nullptr;
11700 bool FoundEquivalentDecl = false;
11701 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
11702 I != E; ++I) {
11703 NamedDecl *D = (*I)->getUnderlyingDecl();
11704 // We can have UsingDecls in our Previous results because we use the same
11705 // LookupResult for checking whether the UsingDecl itself is a valid
11706 // redeclaration.
11707 if (isa<UsingDecl>(D) || isa<UsingPackDecl>(D))
11708 continue;
11709
11710 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
11711 // C++ [class.mem]p19:
11712 // If T is the name of a class, then [every named member other than
11713 // a non-static data member] shall have a name different from T
11714 if (RD->isInjectedClassName() && !isa<FieldDecl>(Target) &&
11715 !isa<IndirectFieldDecl>(Target) &&
11716 !isa<UnresolvedUsingValueDecl>(Target) &&
11717 DiagnoseClassNameShadow(
11718 CurContext,
11719 DeclarationNameInfo(Using->getDeclName(), Using->getLocation())))
11720 return true;
11721 }
11722
11723 if (IsEquivalentForUsingDecl(Context, D, Target)) {
11724 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I))
11725 PrevShadow = Shadow;
11726 FoundEquivalentDecl = true;
11727 } else if (isEquivalentInternalLinkageDeclaration(D, Target)) {
11728 // We don't conflict with an existing using shadow decl of an equivalent
11729 // declaration, but we're not a redeclaration of it.
11730 FoundEquivalentDecl = true;
11731 }
11732
11733 if (isVisible(D))
11734 (isa<TagDecl>(D) ? Tag : NonTag) = D;
11735 }
11736
11737 if (FoundEquivalentDecl)
11738 return false;
11739
11740 if (FunctionDecl *FD = Target->getAsFunction()) {
11741 NamedDecl *OldDecl = nullptr;
11742 switch (CheckOverload(nullptr, FD, Previous, OldDecl,
11743 /*IsForUsingDecl*/ true)) {
11744 case Ovl_Overload:
11745 return false;
11746
11747 case Ovl_NonFunction:
11748 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11749 break;
11750
11751 // We found a decl with the exact signature.
11752 case Ovl_Match:
11753 // If we're in a record, we want to hide the target, so we
11754 // return true (without a diagnostic) to tell the caller not to
11755 // build a shadow decl.
11756 if (CurContext->isRecord())
11757 return true;
11758
11759 // If we're not in a record, this is an error.
11760 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11761 break;
11762 }
11763
11764 Diag(Target->getLocation(), diag::note_using_decl_target);
11765 Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
11766 Using->setInvalidDecl();
11767 return true;
11768 }
11769
11770 // Target is not a function.
11771
11772 if (isa<TagDecl>(Target)) {
11773 // No conflict between a tag and a non-tag.
11774 if (!Tag) return false;
11775
11776 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11777 Diag(Target->getLocation(), diag::note_using_decl_target);
11778 Diag(Tag->getLocation(), diag::note_using_decl_conflict);
11779 Using->setInvalidDecl();
11780 return true;
11781 }
11782
11783 // No conflict between a tag and a non-tag.
11784 if (!NonTag) return false;
11785
11786 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11787 Diag(Target->getLocation(), diag::note_using_decl_target);
11788 Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
11789 Using->setInvalidDecl();
11790 return true;
11791 }
11792
11793 /// Determine whether a direct base class is a virtual base class.
isVirtualDirectBase(CXXRecordDecl * Derived,CXXRecordDecl * Base)11794 static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) {
11795 if (!Derived->getNumVBases())
11796 return false;
11797 for (auto &B : Derived->bases())
11798 if (B.getType()->getAsCXXRecordDecl() == Base)
11799 return B.isVirtual();
11800 llvm_unreachable("not a direct base class");
11801 }
11802
11803 /// Builds a shadow declaration corresponding to a 'using' declaration.
BuildUsingShadowDecl(Scope * S,UsingDecl * UD,NamedDecl * Orig,UsingShadowDecl * PrevDecl)11804 UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
11805 UsingDecl *UD,
11806 NamedDecl *Orig,
11807 UsingShadowDecl *PrevDecl) {
11808 // If we resolved to another shadow declaration, just coalesce them.
11809 NamedDecl *Target = Orig;
11810 if (isa<UsingShadowDecl>(Target)) {
11811 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
11812 assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
11813 }
11814
11815 NamedDecl *NonTemplateTarget = Target;
11816 if (auto *TargetTD = dyn_cast<TemplateDecl>(Target))
11817 NonTemplateTarget = TargetTD->getTemplatedDecl();
11818
11819 UsingShadowDecl *Shadow;
11820 if (NonTemplateTarget && isa<CXXConstructorDecl>(NonTemplateTarget)) {
11821 bool IsVirtualBase =
11822 isVirtualDirectBase(cast<CXXRecordDecl>(CurContext),
11823 UD->getQualifier()->getAsRecordDecl());
11824 Shadow = ConstructorUsingShadowDecl::Create(
11825 Context, CurContext, UD->getLocation(), UD, Orig, IsVirtualBase);
11826 } else {
11827 Shadow = UsingShadowDecl::Create(Context, CurContext, UD->getLocation(), UD,
11828 Target);
11829 }
11830 UD->addShadowDecl(Shadow);
11831
11832 Shadow->setAccess(UD->getAccess());
11833 if (Orig->isInvalidDecl() || UD->isInvalidDecl())
11834 Shadow->setInvalidDecl();
11835
11836 Shadow->setPreviousDecl(PrevDecl);
11837
11838 if (S)
11839 PushOnScopeChains(Shadow, S);
11840 else
11841 CurContext->addDecl(Shadow);
11842
11843
11844 return Shadow;
11845 }
11846
11847 /// Hides a using shadow declaration. This is required by the current
11848 /// using-decl implementation when a resolvable using declaration in a
11849 /// class is followed by a declaration which would hide or override
11850 /// one or more of the using decl's targets; for example:
11851 ///
11852 /// struct Base { void foo(int); };
11853 /// struct Derived : Base {
11854 /// using Base::foo;
11855 /// void foo(int);
11856 /// };
11857 ///
11858 /// The governing language is C++03 [namespace.udecl]p12:
11859 ///
11860 /// When a using-declaration brings names from a base class into a
11861 /// derived class scope, member functions in the derived class
11862 /// override and/or hide member functions with the same name and
11863 /// parameter types in a base class (rather than conflicting).
11864 ///
11865 /// There are two ways to implement this:
11866 /// (1) optimistically create shadow decls when they're not hidden
11867 /// by existing declarations, or
11868 /// (2) don't create any shadow decls (or at least don't make them
11869 /// visible) until we've fully parsed/instantiated the class.
11870 /// The problem with (1) is that we might have to retroactively remove
11871 /// a shadow decl, which requires several O(n) operations because the
11872 /// decl structures are (very reasonably) not designed for removal.
11873 /// (2) avoids this but is very fiddly and phase-dependent.
HideUsingShadowDecl(Scope * S,UsingShadowDecl * Shadow)11874 void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
11875 if (Shadow->getDeclName().getNameKind() ==
11876 DeclarationName::CXXConversionFunctionName)
11877 cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
11878
11879 // Remove it from the DeclContext...
11880 Shadow->getDeclContext()->removeDecl(Shadow);
11881
11882 // ...and the scope, if applicable...
11883 if (S) {
11884 S->RemoveDecl(Shadow);
11885 IdResolver.RemoveDecl(Shadow);
11886 }
11887
11888 // ...and the using decl.
11889 Shadow->getUsingDecl()->removeShadowDecl(Shadow);
11890
11891 // TODO: complain somehow if Shadow was used. It shouldn't
11892 // be possible for this to happen, because...?
11893 }
11894
11895 /// Find the base specifier for a base class with the given type.
findDirectBaseWithType(CXXRecordDecl * Derived,QualType DesiredBase,bool & AnyDependentBases)11896 static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived,
11897 QualType DesiredBase,
11898 bool &AnyDependentBases) {
11899 // Check whether the named type is a direct base class.
11900 CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified()
11901 .getUnqualifiedType();
11902 for (auto &Base : Derived->bases()) {
11903 CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified();
11904 if (CanonicalDesiredBase == BaseType)
11905 return &Base;
11906 if (BaseType->isDependentType())
11907 AnyDependentBases = true;
11908 }
11909 return nullptr;
11910 }
11911
11912 namespace {
11913 class UsingValidatorCCC final : public CorrectionCandidateCallback {
11914 public:
UsingValidatorCCC(bool HasTypenameKeyword,bool IsInstantiation,NestedNameSpecifier * NNS,CXXRecordDecl * RequireMemberOf)11915 UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation,
11916 NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf)
11917 : HasTypenameKeyword(HasTypenameKeyword),
11918 IsInstantiation(IsInstantiation), OldNNS(NNS),
11919 RequireMemberOf(RequireMemberOf) {}
11920
ValidateCandidate(const TypoCorrection & Candidate)11921 bool ValidateCandidate(const TypoCorrection &Candidate) override {
11922 NamedDecl *ND = Candidate.getCorrectionDecl();
11923
11924 // Keywords are not valid here.
11925 if (!ND || isa<NamespaceDecl>(ND))
11926 return false;
11927
11928 // Completely unqualified names are invalid for a 'using' declaration.
11929 if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier())
11930 return false;
11931
11932 // FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would
11933 // reject.
11934
11935 if (RequireMemberOf) {
11936 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
11937 if (FoundRecord && FoundRecord->isInjectedClassName()) {
11938 // No-one ever wants a using-declaration to name an injected-class-name
11939 // of a base class, unless they're declaring an inheriting constructor.
11940 ASTContext &Ctx = ND->getASTContext();
11941 if (!Ctx.getLangOpts().CPlusPlus11)
11942 return false;
11943 QualType FoundType = Ctx.getRecordType(FoundRecord);
11944
11945 // Check that the injected-class-name is named as a member of its own
11946 // type; we don't want to suggest 'using Derived::Base;', since that
11947 // means something else.
11948 NestedNameSpecifier *Specifier =
11949 Candidate.WillReplaceSpecifier()
11950 ? Candidate.getCorrectionSpecifier()
11951 : OldNNS;
11952 if (!Specifier->getAsType() ||
11953 !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType))
11954 return false;
11955
11956 // Check that this inheriting constructor declaration actually names a
11957 // direct base class of the current class.
11958 bool AnyDependentBases = false;
11959 if (!findDirectBaseWithType(RequireMemberOf,
11960 Ctx.getRecordType(FoundRecord),
11961 AnyDependentBases) &&
11962 !AnyDependentBases)
11963 return false;
11964 } else {
11965 auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext());
11966 if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD))
11967 return false;
11968
11969 // FIXME: Check that the base class member is accessible?
11970 }
11971 } else {
11972 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
11973 if (FoundRecord && FoundRecord->isInjectedClassName())
11974 return false;
11975 }
11976
11977 if (isa<TypeDecl>(ND))
11978 return HasTypenameKeyword || !IsInstantiation;
11979
11980 return !HasTypenameKeyword;
11981 }
11982
clone()11983 std::unique_ptr<CorrectionCandidateCallback> clone() override {
11984 return std::make_unique<UsingValidatorCCC>(*this);
11985 }
11986
11987 private:
11988 bool HasTypenameKeyword;
11989 bool IsInstantiation;
11990 NestedNameSpecifier *OldNNS;
11991 CXXRecordDecl *RequireMemberOf;
11992 };
11993 } // end anonymous namespace
11994
11995 /// Builds a using declaration.
11996 ///
11997 /// \param IsInstantiation - Whether this call arises from an
11998 /// instantiation of an unresolved using declaration. We treat
11999 /// the lookup differently for these declarations.
BuildUsingDeclaration(Scope * S,AccessSpecifier AS,SourceLocation UsingLoc,bool HasTypenameKeyword,SourceLocation TypenameLoc,CXXScopeSpec & SS,DeclarationNameInfo NameInfo,SourceLocation EllipsisLoc,const ParsedAttributesView & AttrList,bool IsInstantiation)12000 NamedDecl *Sema::BuildUsingDeclaration(
12001 Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
12002 bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
12003 DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
12004 const ParsedAttributesView &AttrList, bool IsInstantiation) {
12005 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
12006 SourceLocation IdentLoc = NameInfo.getLoc();
12007 assert(IdentLoc.isValid() && "Invalid TargetName location.");
12008
12009 // FIXME: We ignore attributes for now.
12010
12011 // For an inheriting constructor declaration, the name of the using
12012 // declaration is the name of a constructor in this class, not in the
12013 // base class.
12014 DeclarationNameInfo UsingName = NameInfo;
12015 if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName)
12016 if (auto *RD = dyn_cast<CXXRecordDecl>(CurContext))
12017 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
12018 Context.getCanonicalType(Context.getRecordType(RD))));
12019
12020 // Do the redeclaration lookup in the current scope.
12021 LookupResult Previous(*this, UsingName, LookupUsingDeclName,
12022 ForVisibleRedeclaration);
12023 Previous.setHideTags(false);
12024 if (S) {
12025 LookupName(Previous, S);
12026
12027 // It is really dumb that we have to do this.
12028 LookupResult::Filter F = Previous.makeFilter();
12029 while (F.hasNext()) {
12030 NamedDecl *D = F.next();
12031 if (!isDeclInScope(D, CurContext, S))
12032 F.erase();
12033 // If we found a local extern declaration that's not ordinarily visible,
12034 // and this declaration is being added to a non-block scope, ignore it.
12035 // We're only checking for scope conflicts here, not also for violations
12036 // of the linkage rules.
12037 else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() &&
12038 !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary))
12039 F.erase();
12040 }
12041 F.done();
12042 } else {
12043 assert(IsInstantiation && "no scope in non-instantiation");
12044 if (CurContext->isRecord())
12045 LookupQualifiedName(Previous, CurContext);
12046 else {
12047 // No redeclaration check is needed here; in non-member contexts we
12048 // diagnosed all possible conflicts with other using-declarations when
12049 // building the template:
12050 //
12051 // For a dependent non-type using declaration, the only valid case is
12052 // if we instantiate to a single enumerator. We check for conflicts
12053 // between shadow declarations we introduce, and we check in the template
12054 // definition for conflicts between a non-type using declaration and any
12055 // other declaration, which together covers all cases.
12056 //
12057 // A dependent typename using declaration will never successfully
12058 // instantiate, since it will always name a class member, so we reject
12059 // that in the template definition.
12060 }
12061 }
12062
12063 // Check for invalid redeclarations.
12064 if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword,
12065 SS, IdentLoc, Previous))
12066 return nullptr;
12067
12068 // Check for bad qualifiers.
12069 if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo,
12070 IdentLoc))
12071 return nullptr;
12072
12073 DeclContext *LookupContext = computeDeclContext(SS);
12074 NamedDecl *D;
12075 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
12076 if (!LookupContext || EllipsisLoc.isValid()) {
12077 if (HasTypenameKeyword) {
12078 // FIXME: not all declaration name kinds are legal here
12079 D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
12080 UsingLoc, TypenameLoc,
12081 QualifierLoc,
12082 IdentLoc, NameInfo.getName(),
12083 EllipsisLoc);
12084 } else {
12085 D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
12086 QualifierLoc, NameInfo, EllipsisLoc);
12087 }
12088 D->setAccess(AS);
12089 CurContext->addDecl(D);
12090 return D;
12091 }
12092
12093 auto Build = [&](bool Invalid) {
12094 UsingDecl *UD =
12095 UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
12096 UsingName, HasTypenameKeyword);
12097 UD->setAccess(AS);
12098 CurContext->addDecl(UD);
12099 UD->setInvalidDecl(Invalid);
12100 return UD;
12101 };
12102 auto BuildInvalid = [&]{ return Build(true); };
12103 auto BuildValid = [&]{ return Build(false); };
12104
12105 if (RequireCompleteDeclContext(SS, LookupContext))
12106 return BuildInvalid();
12107
12108 // Look up the target name.
12109 LookupResult R(*this, NameInfo, LookupOrdinaryName);
12110
12111 // Unlike most lookups, we don't always want to hide tag
12112 // declarations: tag names are visible through the using declaration
12113 // even if hidden by ordinary names, *except* in a dependent context
12114 // where it's important for the sanity of two-phase lookup.
12115 if (!IsInstantiation)
12116 R.setHideTags(false);
12117
12118 // For the purposes of this lookup, we have a base object type
12119 // equal to that of the current context.
12120 if (CurContext->isRecord()) {
12121 R.setBaseObjectType(
12122 Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
12123 }
12124
12125 LookupQualifiedName(R, LookupContext);
12126
12127 // Try to correct typos if possible. If constructor name lookup finds no
12128 // results, that means the named class has no explicit constructors, and we
12129 // suppressed declaring implicit ones (probably because it's dependent or
12130 // invalid).
12131 if (R.empty() &&
12132 NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) {
12133 // HACK 2017-01-08: Work around an issue with libstdc++'s detection of
12134 // ::gets. Sometimes it believes that glibc provides a ::gets in cases where
12135 // it does not. The issue was fixed in libstdc++ 6.3 (2016-12-21) and later.
12136 auto *II = NameInfo.getName().getAsIdentifierInfo();
12137 if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") &&
12138 CurContext->isStdNamespace() &&
12139 isa<TranslationUnitDecl>(LookupContext) &&
12140 getSourceManager().isInSystemHeader(UsingLoc))
12141 return nullptr;
12142 UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(),
12143 dyn_cast<CXXRecordDecl>(CurContext));
12144 if (TypoCorrection Corrected =
12145 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC,
12146 CTK_ErrorRecovery)) {
12147 // We reject candidates where DroppedSpecifier == true, hence the
12148 // literal '0' below.
12149 diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
12150 << NameInfo.getName() << LookupContext << 0
12151 << SS.getRange());
12152
12153 // If we picked a correction with no attached Decl we can't do anything
12154 // useful with it, bail out.
12155 NamedDecl *ND = Corrected.getCorrectionDecl();
12156 if (!ND)
12157 return BuildInvalid();
12158
12159 // If we corrected to an inheriting constructor, handle it as one.
12160 auto *RD = dyn_cast<CXXRecordDecl>(ND);
12161 if (RD && RD->isInjectedClassName()) {
12162 // The parent of the injected class name is the class itself.
12163 RD = cast<CXXRecordDecl>(RD->getParent());
12164
12165 // Fix up the information we'll use to build the using declaration.
12166 if (Corrected.WillReplaceSpecifier()) {
12167 NestedNameSpecifierLocBuilder Builder;
12168 Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
12169 QualifierLoc.getSourceRange());
12170 QualifierLoc = Builder.getWithLocInContext(Context);
12171 }
12172
12173 // In this case, the name we introduce is the name of a derived class
12174 // constructor.
12175 auto *CurClass = cast<CXXRecordDecl>(CurContext);
12176 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
12177 Context.getCanonicalType(Context.getRecordType(CurClass))));
12178 UsingName.setNamedTypeInfo(nullptr);
12179 for (auto *Ctor : LookupConstructors(RD))
12180 R.addDecl(Ctor);
12181 R.resolveKind();
12182 } else {
12183 // FIXME: Pick up all the declarations if we found an overloaded
12184 // function.
12185 UsingName.setName(ND->getDeclName());
12186 R.addDecl(ND);
12187 }
12188 } else {
12189 Diag(IdentLoc, diag::err_no_member)
12190 << NameInfo.getName() << LookupContext << SS.getRange();
12191 return BuildInvalid();
12192 }
12193 }
12194
12195 if (R.isAmbiguous())
12196 return BuildInvalid();
12197
12198 if (HasTypenameKeyword) {
12199 // If we asked for a typename and got a non-type decl, error out.
12200 if (!R.getAsSingle<TypeDecl>()) {
12201 Diag(IdentLoc, diag::err_using_typename_non_type);
12202 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
12203 Diag((*I)->getUnderlyingDecl()->getLocation(),
12204 diag::note_using_decl_target);
12205 return BuildInvalid();
12206 }
12207 } else {
12208 // If we asked for a non-typename and we got a type, error out,
12209 // but only if this is an instantiation of an unresolved using
12210 // decl. Otherwise just silently find the type name.
12211 if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
12212 Diag(IdentLoc, diag::err_using_dependent_value_is_type);
12213 Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
12214 return BuildInvalid();
12215 }
12216 }
12217
12218 // C++14 [namespace.udecl]p6:
12219 // A using-declaration shall not name a namespace.
12220 if (R.getAsSingle<NamespaceDecl>()) {
12221 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
12222 << SS.getRange();
12223 return BuildInvalid();
12224 }
12225
12226 // C++14 [namespace.udecl]p7:
12227 // A using-declaration shall not name a scoped enumerator.
12228 if (auto *ED = R.getAsSingle<EnumConstantDecl>()) {
12229 if (cast<EnumDecl>(ED->getDeclContext())->isScoped()) {
12230 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_scoped_enum)
12231 << SS.getRange();
12232 return BuildInvalid();
12233 }
12234 }
12235
12236 UsingDecl *UD = BuildValid();
12237
12238 // Some additional rules apply to inheriting constructors.
12239 if (UsingName.getName().getNameKind() ==
12240 DeclarationName::CXXConstructorName) {
12241 // Suppress access diagnostics; the access check is instead performed at the
12242 // point of use for an inheriting constructor.
12243 R.suppressDiagnostics();
12244 if (CheckInheritingConstructorUsingDecl(UD))
12245 return UD;
12246 }
12247
12248 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
12249 UsingShadowDecl *PrevDecl = nullptr;
12250 if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl))
12251 BuildUsingShadowDecl(S, UD, *I, PrevDecl);
12252 }
12253
12254 return UD;
12255 }
12256
BuildUsingPackDecl(NamedDecl * InstantiatedFrom,ArrayRef<NamedDecl * > Expansions)12257 NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
12258 ArrayRef<NamedDecl *> Expansions) {
12259 assert(isa<UnresolvedUsingValueDecl>(InstantiatedFrom) ||
12260 isa<UnresolvedUsingTypenameDecl>(InstantiatedFrom) ||
12261 isa<UsingPackDecl>(InstantiatedFrom));
12262
12263 auto *UPD =
12264 UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions);
12265 UPD->setAccess(InstantiatedFrom->getAccess());
12266 CurContext->addDecl(UPD);
12267 return UPD;
12268 }
12269
12270 /// Additional checks for a using declaration referring to a constructor name.
CheckInheritingConstructorUsingDecl(UsingDecl * UD)12271 bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
12272 assert(!UD->hasTypename() && "expecting a constructor name");
12273
12274 const Type *SourceType = UD->getQualifier()->getAsType();
12275 assert(SourceType &&
12276 "Using decl naming constructor doesn't have type in scope spec.");
12277 CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
12278
12279 // Check whether the named type is a direct base class.
12280 bool AnyDependentBases = false;
12281 auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0),
12282 AnyDependentBases);
12283 if (!Base && !AnyDependentBases) {
12284 Diag(UD->getUsingLoc(),
12285 diag::err_using_decl_constructor_not_in_direct_base)
12286 << UD->getNameInfo().getSourceRange()
12287 << QualType(SourceType, 0) << TargetClass;
12288 UD->setInvalidDecl();
12289 return true;
12290 }
12291
12292 if (Base)
12293 Base->setInheritConstructors();
12294
12295 return false;
12296 }
12297
12298 /// Checks that the given using declaration is not an invalid
12299 /// redeclaration. Note that this is checking only for the using decl
12300 /// itself, not for any ill-formedness among the UsingShadowDecls.
CheckUsingDeclRedeclaration(SourceLocation UsingLoc,bool HasTypenameKeyword,const CXXScopeSpec & SS,SourceLocation NameLoc,const LookupResult & Prev)12301 bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
12302 bool HasTypenameKeyword,
12303 const CXXScopeSpec &SS,
12304 SourceLocation NameLoc,
12305 const LookupResult &Prev) {
12306 NestedNameSpecifier *Qual = SS.getScopeRep();
12307
12308 // C++03 [namespace.udecl]p8:
12309 // C++0x [namespace.udecl]p10:
12310 // A using-declaration is a declaration and can therefore be used
12311 // repeatedly where (and only where) multiple declarations are
12312 // allowed.
12313 //
12314 // That's in non-member contexts.
12315 if (!CurContext->getRedeclContext()->isRecord()) {
12316 // A dependent qualifier outside a class can only ever resolve to an
12317 // enumeration type. Therefore it conflicts with any other non-type
12318 // declaration in the same scope.
12319 // FIXME: How should we check for dependent type-type conflicts at block
12320 // scope?
12321 if (Qual->isDependent() && !HasTypenameKeyword) {
12322 for (auto *D : Prev) {
12323 if (!isa<TypeDecl>(D) && !isa<UsingDecl>(D) && !isa<UsingPackDecl>(D)) {
12324 bool OldCouldBeEnumerator =
12325 isa<UnresolvedUsingValueDecl>(D) || isa<EnumConstantDecl>(D);
12326 Diag(NameLoc,
12327 OldCouldBeEnumerator ? diag::err_redefinition
12328 : diag::err_redefinition_different_kind)
12329 << Prev.getLookupName();
12330 Diag(D->getLocation(), diag::note_previous_definition);
12331 return true;
12332 }
12333 }
12334 }
12335 return false;
12336 }
12337
12338 for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
12339 NamedDecl *D = *I;
12340
12341 bool DTypename;
12342 NestedNameSpecifier *DQual;
12343 if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
12344 DTypename = UD->hasTypename();
12345 DQual = UD->getQualifier();
12346 } else if (UnresolvedUsingValueDecl *UD
12347 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
12348 DTypename = false;
12349 DQual = UD->getQualifier();
12350 } else if (UnresolvedUsingTypenameDecl *UD
12351 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
12352 DTypename = true;
12353 DQual = UD->getQualifier();
12354 } else continue;
12355
12356 // using decls differ if one says 'typename' and the other doesn't.
12357 // FIXME: non-dependent using decls?
12358 if (HasTypenameKeyword != DTypename) continue;
12359
12360 // using decls differ if they name different scopes (but note that
12361 // template instantiation can cause this check to trigger when it
12362 // didn't before instantiation).
12363 if (Context.getCanonicalNestedNameSpecifier(Qual) !=
12364 Context.getCanonicalNestedNameSpecifier(DQual))
12365 continue;
12366
12367 Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
12368 Diag(D->getLocation(), diag::note_using_decl) << 1;
12369 return true;
12370 }
12371
12372 return false;
12373 }
12374
12375
12376 /// Checks that the given nested-name qualifier used in a using decl
12377 /// in the current context is appropriately related to the current
12378 /// scope. If an error is found, diagnoses it and returns true.
CheckUsingDeclQualifier(SourceLocation UsingLoc,bool HasTypename,const CXXScopeSpec & SS,const DeclarationNameInfo & NameInfo,SourceLocation NameLoc)12379 bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
12380 bool HasTypename,
12381 const CXXScopeSpec &SS,
12382 const DeclarationNameInfo &NameInfo,
12383 SourceLocation NameLoc) {
12384 DeclContext *NamedContext = computeDeclContext(SS);
12385
12386 if (!CurContext->isRecord()) {
12387 // C++03 [namespace.udecl]p3:
12388 // C++0x [namespace.udecl]p8:
12389 // A using-declaration for a class member shall be a member-declaration.
12390
12391 // If we weren't able to compute a valid scope, it might validly be a
12392 // dependent class scope or a dependent enumeration unscoped scope. If
12393 // we have a 'typename' keyword, the scope must resolve to a class type.
12394 if ((HasTypename && !NamedContext) ||
12395 (NamedContext && NamedContext->getRedeclContext()->isRecord())) {
12396 auto *RD = NamedContext
12397 ? cast<CXXRecordDecl>(NamedContext->getRedeclContext())
12398 : nullptr;
12399 if (RD && RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), RD))
12400 RD = nullptr;
12401
12402 Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
12403 << SS.getRange();
12404
12405 // If we have a complete, non-dependent source type, try to suggest a
12406 // way to get the same effect.
12407 if (!RD)
12408 return true;
12409
12410 // Find what this using-declaration was referring to.
12411 LookupResult R(*this, NameInfo, LookupOrdinaryName);
12412 R.setHideTags(false);
12413 R.suppressDiagnostics();
12414 LookupQualifiedName(R, RD);
12415
12416 if (R.getAsSingle<TypeDecl>()) {
12417 if (getLangOpts().CPlusPlus11) {
12418 // Convert 'using X::Y;' to 'using Y = X::Y;'.
12419 Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround)
12420 << 0 // alias declaration
12421 << FixItHint::CreateInsertion(SS.getBeginLoc(),
12422 NameInfo.getName().getAsString() +
12423 " = ");
12424 } else {
12425 // Convert 'using X::Y;' to 'typedef X::Y Y;'.
12426 SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc());
12427 Diag(InsertLoc, diag::note_using_decl_class_member_workaround)
12428 << 1 // typedef declaration
12429 << FixItHint::CreateReplacement(UsingLoc, "typedef")
12430 << FixItHint::CreateInsertion(
12431 InsertLoc, " " + NameInfo.getName().getAsString());
12432 }
12433 } else if (R.getAsSingle<VarDecl>()) {
12434 // Don't provide a fixit outside C++11 mode; we don't want to suggest
12435 // repeating the type of the static data member here.
12436 FixItHint FixIt;
12437 if (getLangOpts().CPlusPlus11) {
12438 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
12439 FixIt = FixItHint::CreateReplacement(
12440 UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = ");
12441 }
12442
12443 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
12444 << 2 // reference declaration
12445 << FixIt;
12446 } else if (R.getAsSingle<EnumConstantDecl>()) {
12447 // Don't provide a fixit outside C++11 mode; we don't want to suggest
12448 // repeating the type of the enumeration here, and we can't do so if
12449 // the type is anonymous.
12450 FixItHint FixIt;
12451 if (getLangOpts().CPlusPlus11) {
12452 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
12453 FixIt = FixItHint::CreateReplacement(
12454 UsingLoc,
12455 "constexpr auto " + NameInfo.getName().getAsString() + " = ");
12456 }
12457
12458 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
12459 << (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable
12460 << FixIt;
12461 }
12462 return true;
12463 }
12464
12465 // Otherwise, this might be valid.
12466 return false;
12467 }
12468
12469 // The current scope is a record.
12470
12471 // If the named context is dependent, we can't decide much.
12472 if (!NamedContext) {
12473 // FIXME: in C++0x, we can diagnose if we can prove that the
12474 // nested-name-specifier does not refer to a base class, which is
12475 // still possible in some cases.
12476
12477 // Otherwise we have to conservatively report that things might be
12478 // okay.
12479 return false;
12480 }
12481
12482 if (!NamedContext->isRecord()) {
12483 // Ideally this would point at the last name in the specifier,
12484 // but we don't have that level of source info.
12485 Diag(SS.getRange().getBegin(),
12486 diag::err_using_decl_nested_name_specifier_is_not_class)
12487 << SS.getScopeRep() << SS.getRange();
12488 return true;
12489 }
12490
12491 if (!NamedContext->isDependentContext() &&
12492 RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
12493 return true;
12494
12495 if (getLangOpts().CPlusPlus11) {
12496 // C++11 [namespace.udecl]p3:
12497 // In a using-declaration used as a member-declaration, the
12498 // nested-name-specifier shall name a base class of the class
12499 // being defined.
12500
12501 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
12502 cast<CXXRecordDecl>(NamedContext))) {
12503 if (CurContext == NamedContext) {
12504 Diag(NameLoc,
12505 diag::err_using_decl_nested_name_specifier_is_current_class)
12506 << SS.getRange();
12507 return true;
12508 }
12509
12510 if (!cast<CXXRecordDecl>(NamedContext)->isInvalidDecl()) {
12511 Diag(SS.getRange().getBegin(),
12512 diag::err_using_decl_nested_name_specifier_is_not_base_class)
12513 << SS.getScopeRep()
12514 << cast<CXXRecordDecl>(CurContext)
12515 << SS.getRange();
12516 }
12517 return true;
12518 }
12519
12520 return false;
12521 }
12522
12523 // C++03 [namespace.udecl]p4:
12524 // A using-declaration used as a member-declaration shall refer
12525 // to a member of a base class of the class being defined [etc.].
12526
12527 // Salient point: SS doesn't have to name a base class as long as
12528 // lookup only finds members from base classes. Therefore we can
12529 // diagnose here only if we can prove that that can't happen,
12530 // i.e. if the class hierarchies provably don't intersect.
12531
12532 // TODO: it would be nice if "definitely valid" results were cached
12533 // in the UsingDecl and UsingShadowDecl so that these checks didn't
12534 // need to be repeated.
12535
12536 llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases;
12537 auto Collect = [&Bases](const CXXRecordDecl *Base) {
12538 Bases.insert(Base);
12539 return true;
12540 };
12541
12542 // Collect all bases. Return false if we find a dependent base.
12543 if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect))
12544 return false;
12545
12546 // Returns true if the base is dependent or is one of the accumulated base
12547 // classes.
12548 auto IsNotBase = [&Bases](const CXXRecordDecl *Base) {
12549 return !Bases.count(Base);
12550 };
12551
12552 // Return false if the class has a dependent base or if it or one
12553 // of its bases is present in the base set of the current context.
12554 if (Bases.count(cast<CXXRecordDecl>(NamedContext)) ||
12555 !cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase))
12556 return false;
12557
12558 Diag(SS.getRange().getBegin(),
12559 diag::err_using_decl_nested_name_specifier_is_not_base_class)
12560 << SS.getScopeRep()
12561 << cast<CXXRecordDecl>(CurContext)
12562 << SS.getRange();
12563
12564 return true;
12565 }
12566
ActOnAliasDeclaration(Scope * S,AccessSpecifier AS,MultiTemplateParamsArg TemplateParamLists,SourceLocation UsingLoc,UnqualifiedId & Name,const ParsedAttributesView & AttrList,TypeResult Type,Decl * DeclFromDeclSpec)12567 Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS,
12568 MultiTemplateParamsArg TemplateParamLists,
12569 SourceLocation UsingLoc, UnqualifiedId &Name,
12570 const ParsedAttributesView &AttrList,
12571 TypeResult Type, Decl *DeclFromDeclSpec) {
12572 // Skip up to the relevant declaration scope.
12573 while (S->isTemplateParamScope())
12574 S = S->getParent();
12575 assert((S->getFlags() & Scope::DeclScope) &&
12576 "got alias-declaration outside of declaration scope");
12577
12578 if (Type.isInvalid())
12579 return nullptr;
12580
12581 bool Invalid = false;
12582 DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
12583 TypeSourceInfo *TInfo = nullptr;
12584 GetTypeFromParser(Type.get(), &TInfo);
12585
12586 if (DiagnoseClassNameShadow(CurContext, NameInfo))
12587 return nullptr;
12588
12589 if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
12590 UPPC_DeclarationType)) {
12591 Invalid = true;
12592 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
12593 TInfo->getTypeLoc().getBeginLoc());
12594 }
12595
12596 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
12597 TemplateParamLists.size()
12598 ? forRedeclarationInCurContext()
12599 : ForVisibleRedeclaration);
12600 LookupName(Previous, S);
12601
12602 // Warn about shadowing the name of a template parameter.
12603 if (Previous.isSingleResult() &&
12604 Previous.getFoundDecl()->isTemplateParameter()) {
12605 DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
12606 Previous.clear();
12607 }
12608
12609 assert(Name.Kind == UnqualifiedIdKind::IK_Identifier &&
12610 "name in alias declaration must be an identifier");
12611 TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
12612 Name.StartLocation,
12613 Name.Identifier, TInfo);
12614
12615 NewTD->setAccess(AS);
12616
12617 if (Invalid)
12618 NewTD->setInvalidDecl();
12619
12620 ProcessDeclAttributeList(S, NewTD, AttrList);
12621 AddPragmaAttributes(S, NewTD);
12622
12623 CheckTypedefForVariablyModifiedType(S, NewTD);
12624 Invalid |= NewTD->isInvalidDecl();
12625
12626 bool Redeclaration = false;
12627
12628 NamedDecl *NewND;
12629 if (TemplateParamLists.size()) {
12630 TypeAliasTemplateDecl *OldDecl = nullptr;
12631 TemplateParameterList *OldTemplateParams = nullptr;
12632
12633 if (TemplateParamLists.size() != 1) {
12634 Diag(UsingLoc, diag::err_alias_template_extra_headers)
12635 << SourceRange(TemplateParamLists[1]->getTemplateLoc(),
12636 TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc());
12637 }
12638 TemplateParameterList *TemplateParams = TemplateParamLists[0];
12639
12640 // Check that we can declare a template here.
12641 if (CheckTemplateDeclScope(S, TemplateParams))
12642 return nullptr;
12643
12644 // Only consider previous declarations in the same scope.
12645 FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
12646 /*ExplicitInstantiationOrSpecialization*/false);
12647 if (!Previous.empty()) {
12648 Redeclaration = true;
12649
12650 OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
12651 if (!OldDecl && !Invalid) {
12652 Diag(UsingLoc, diag::err_redefinition_different_kind)
12653 << Name.Identifier;
12654
12655 NamedDecl *OldD = Previous.getRepresentativeDecl();
12656 if (OldD->getLocation().isValid())
12657 Diag(OldD->getLocation(), diag::note_previous_definition);
12658
12659 Invalid = true;
12660 }
12661
12662 if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
12663 if (TemplateParameterListsAreEqual(TemplateParams,
12664 OldDecl->getTemplateParameters(),
12665 /*Complain=*/true,
12666 TPL_TemplateMatch))
12667 OldTemplateParams =
12668 OldDecl->getMostRecentDecl()->getTemplateParameters();
12669 else
12670 Invalid = true;
12671
12672 TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
12673 if (!Invalid &&
12674 !Context.hasSameType(OldTD->getUnderlyingType(),
12675 NewTD->getUnderlyingType())) {
12676 // FIXME: The C++0x standard does not clearly say this is ill-formed,
12677 // but we can't reasonably accept it.
12678 Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
12679 << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
12680 if (OldTD->getLocation().isValid())
12681 Diag(OldTD->getLocation(), diag::note_previous_definition);
12682 Invalid = true;
12683 }
12684 }
12685 }
12686
12687 // Merge any previous default template arguments into our parameters,
12688 // and check the parameter list.
12689 if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
12690 TPC_TypeAliasTemplate))
12691 return nullptr;
12692
12693 TypeAliasTemplateDecl *NewDecl =
12694 TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
12695 Name.Identifier, TemplateParams,
12696 NewTD);
12697 NewTD->setDescribedAliasTemplate(NewDecl);
12698
12699 NewDecl->setAccess(AS);
12700
12701 if (Invalid)
12702 NewDecl->setInvalidDecl();
12703 else if (OldDecl) {
12704 NewDecl->setPreviousDecl(OldDecl);
12705 CheckRedeclarationModuleOwnership(NewDecl, OldDecl);
12706 }
12707
12708 NewND = NewDecl;
12709 } else {
12710 if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) {
12711 setTagNameForLinkagePurposes(TD, NewTD);
12712 handleTagNumbering(TD, S);
12713 }
12714 ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
12715 NewND = NewTD;
12716 }
12717
12718 PushOnScopeChains(NewND, S);
12719 ActOnDocumentableDecl(NewND);
12720 return NewND;
12721 }
12722
ActOnNamespaceAliasDef(Scope * S,SourceLocation NamespaceLoc,SourceLocation AliasLoc,IdentifierInfo * Alias,CXXScopeSpec & SS,SourceLocation IdentLoc,IdentifierInfo * Ident)12723 Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
12724 SourceLocation AliasLoc,
12725 IdentifierInfo *Alias, CXXScopeSpec &SS,
12726 SourceLocation IdentLoc,
12727 IdentifierInfo *Ident) {
12728
12729 // Lookup the namespace name.
12730 LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
12731 LookupParsedName(R, S, &SS);
12732
12733 if (R.isAmbiguous())
12734 return nullptr;
12735
12736 if (R.empty()) {
12737 if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
12738 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
12739 return nullptr;
12740 }
12741 }
12742 assert(!R.isAmbiguous() && !R.empty());
12743 NamedDecl *ND = R.getRepresentativeDecl();
12744
12745 // Check if we have a previous declaration with the same name.
12746 LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName,
12747 ForVisibleRedeclaration);
12748 LookupName(PrevR, S);
12749
12750 // Check we're not shadowing a template parameter.
12751 if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) {
12752 DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl());
12753 PrevR.clear();
12754 }
12755
12756 // Filter out any other lookup result from an enclosing scope.
12757 FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false,
12758 /*AllowInlineNamespace*/false);
12759
12760 // Find the previous declaration and check that we can redeclare it.
12761 NamespaceAliasDecl *Prev = nullptr;
12762 if (PrevR.isSingleResult()) {
12763 NamedDecl *PrevDecl = PrevR.getRepresentativeDecl();
12764 if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
12765 // We already have an alias with the same name that points to the same
12766 // namespace; check that it matches.
12767 if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
12768 Prev = AD;
12769 } else if (isVisible(PrevDecl)) {
12770 Diag(AliasLoc, diag::err_redefinition_different_namespace_alias)
12771 << Alias;
12772 Diag(AD->getLocation(), diag::note_previous_namespace_alias)
12773 << AD->getNamespace();
12774 return nullptr;
12775 }
12776 } else if (isVisible(PrevDecl)) {
12777 unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl())
12778 ? diag::err_redefinition
12779 : diag::err_redefinition_different_kind;
12780 Diag(AliasLoc, DiagID) << Alias;
12781 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
12782 return nullptr;
12783 }
12784 }
12785
12786 // The use of a nested name specifier may trigger deprecation warnings.
12787 DiagnoseUseOfDecl(ND, IdentLoc);
12788
12789 NamespaceAliasDecl *AliasDecl =
12790 NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
12791 Alias, SS.getWithLocInContext(Context),
12792 IdentLoc, ND);
12793 if (Prev)
12794 AliasDecl->setPreviousDecl(Prev);
12795
12796 PushOnScopeChains(AliasDecl, S);
12797 return AliasDecl;
12798 }
12799
12800 namespace {
12801 struct SpecialMemberExceptionSpecInfo
12802 : SpecialMemberVisitor<SpecialMemberExceptionSpecInfo> {
12803 SourceLocation Loc;
12804 Sema::ImplicitExceptionSpecification ExceptSpec;
12805
SpecialMemberExceptionSpecInfo__anonb2a824813511::SpecialMemberExceptionSpecInfo12806 SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD,
12807 Sema::CXXSpecialMember CSM,
12808 Sema::InheritedConstructorInfo *ICI,
12809 SourceLocation Loc)
12810 : SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {}
12811
12812 bool visitBase(CXXBaseSpecifier *Base);
12813 bool visitField(FieldDecl *FD);
12814
12815 void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
12816 unsigned Quals);
12817
12818 void visitSubobjectCall(Subobject Subobj,
12819 Sema::SpecialMemberOverloadResult SMOR);
12820 };
12821 }
12822
visitBase(CXXBaseSpecifier * Base)12823 bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) {
12824 auto *RT = Base->getType()->getAs<RecordType>();
12825 if (!RT)
12826 return false;
12827
12828 auto *BaseClass = cast<CXXRecordDecl>(RT->getDecl());
12829 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
12830 if (auto *BaseCtor = SMOR.getMethod()) {
12831 visitSubobjectCall(Base, BaseCtor);
12832 return false;
12833 }
12834
12835 visitClassSubobject(BaseClass, Base, 0);
12836 return false;
12837 }
12838
visitField(FieldDecl * FD)12839 bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) {
12840 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) {
12841 Expr *E = FD->getInClassInitializer();
12842 if (!E)
12843 // FIXME: It's a little wasteful to build and throw away a
12844 // CXXDefaultInitExpr here.
12845 // FIXME: We should have a single context note pointing at Loc, and
12846 // this location should be MD->getLocation() instead, since that's
12847 // the location where we actually use the default init expression.
12848 E = S.BuildCXXDefaultInitExpr(Loc, FD).get();
12849 if (E)
12850 ExceptSpec.CalledExpr(E);
12851 } else if (auto *RT = S.Context.getBaseElementType(FD->getType())
12852 ->getAs<RecordType>()) {
12853 visitClassSubobject(cast<CXXRecordDecl>(RT->getDecl()), FD,
12854 FD->getType().getCVRQualifiers());
12855 }
12856 return false;
12857 }
12858
visitClassSubobject(CXXRecordDecl * Class,Subobject Subobj,unsigned Quals)12859 void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class,
12860 Subobject Subobj,
12861 unsigned Quals) {
12862 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
12863 bool IsMutable = Field && Field->isMutable();
12864 visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable));
12865 }
12866
visitSubobjectCall(Subobject Subobj,Sema::SpecialMemberOverloadResult SMOR)12867 void SpecialMemberExceptionSpecInfo::visitSubobjectCall(
12868 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) {
12869 // Note, if lookup fails, it doesn't matter what exception specification we
12870 // choose because the special member will be deleted.
12871 if (CXXMethodDecl *MD = SMOR.getMethod())
12872 ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD);
12873 }
12874
tryResolveExplicitSpecifier(ExplicitSpecifier & ExplicitSpec)12875 bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) {
12876 llvm::APSInt Result;
12877 ExprResult Converted = CheckConvertedConstantExpression(
12878 ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool);
12879 ExplicitSpec.setExpr(Converted.get());
12880 if (Converted.isUsable() && !Converted.get()->isValueDependent()) {
12881 ExplicitSpec.setKind(Result.getBoolValue()
12882 ? ExplicitSpecKind::ResolvedTrue
12883 : ExplicitSpecKind::ResolvedFalse);
12884 return true;
12885 }
12886 ExplicitSpec.setKind(ExplicitSpecKind::Unresolved);
12887 return false;
12888 }
12889
ActOnExplicitBoolSpecifier(Expr * ExplicitExpr)12890 ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) {
12891 ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved);
12892 if (!ExplicitExpr->isTypeDependent())
12893 tryResolveExplicitSpecifier(ES);
12894 return ES;
12895 }
12896
12897 static Sema::ImplicitExceptionSpecification
ComputeDefaultedSpecialMemberExceptionSpec(Sema & S,SourceLocation Loc,CXXMethodDecl * MD,Sema::CXXSpecialMember CSM,Sema::InheritedConstructorInfo * ICI)12898 ComputeDefaultedSpecialMemberExceptionSpec(
12899 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
12900 Sema::InheritedConstructorInfo *ICI) {
12901 ComputingExceptionSpec CES(S, MD, Loc);
12902
12903 CXXRecordDecl *ClassDecl = MD->getParent();
12904
12905 // C++ [except.spec]p14:
12906 // An implicitly declared special member function (Clause 12) shall have an
12907 // exception-specification. [...]
12908 SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation());
12909 if (ClassDecl->isInvalidDecl())
12910 return Info.ExceptSpec;
12911
12912 // FIXME: If this diagnostic fires, we're probably missing a check for
12913 // attempting to resolve an exception specification before it's known
12914 // at a higher level.
12915 if (S.RequireCompleteType(MD->getLocation(),
12916 S.Context.getRecordType(ClassDecl),
12917 diag::err_exception_spec_incomplete_type))
12918 return Info.ExceptSpec;
12919
12920 // C++1z [except.spec]p7:
12921 // [Look for exceptions thrown by] a constructor selected [...] to
12922 // initialize a potentially constructed subobject,
12923 // C++1z [except.spec]p8:
12924 // The exception specification for an implicitly-declared destructor, or a
12925 // destructor without a noexcept-specifier, is potentially-throwing if and
12926 // only if any of the destructors for any of its potentially constructed
12927 // subojects is potentially throwing.
12928 // FIXME: We respect the first rule but ignore the "potentially constructed"
12929 // in the second rule to resolve a core issue (no number yet) that would have
12930 // us reject:
12931 // struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; };
12932 // struct B : A {};
12933 // struct C : B { void f(); };
12934 // ... due to giving B::~B() a non-throwing exception specification.
12935 Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases
12936 : Info.VisitAllBases);
12937
12938 return Info.ExceptSpec;
12939 }
12940
12941 namespace {
12942 /// RAII object to register a special member as being currently declared.
12943 struct DeclaringSpecialMember {
12944 Sema &S;
12945 Sema::SpecialMemberDecl D;
12946 Sema::ContextRAII SavedContext;
12947 bool WasAlreadyBeingDeclared;
12948
DeclaringSpecialMember__anonb2a824813611::DeclaringSpecialMember12949 DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM)
12950 : S(S), D(RD, CSM), SavedContext(S, RD) {
12951 WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second;
12952 if (WasAlreadyBeingDeclared)
12953 // This almost never happens, but if it does, ensure that our cache
12954 // doesn't contain a stale result.
12955 S.SpecialMemberCache.clear();
12956 else {
12957 // Register a note to be produced if we encounter an error while
12958 // declaring the special member.
12959 Sema::CodeSynthesisContext Ctx;
12960 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember;
12961 // FIXME: We don't have a location to use here. Using the class's
12962 // location maintains the fiction that we declare all special members
12963 // with the class, but (1) it's not clear that lying about that helps our
12964 // users understand what's going on, and (2) there may be outer contexts
12965 // on the stack (some of which are relevant) and printing them exposes
12966 // our lies.
12967 Ctx.PointOfInstantiation = RD->getLocation();
12968 Ctx.Entity = RD;
12969 Ctx.SpecialMember = CSM;
12970 S.pushCodeSynthesisContext(Ctx);
12971 }
12972 }
~DeclaringSpecialMember__anonb2a824813611::DeclaringSpecialMember12973 ~DeclaringSpecialMember() {
12974 if (!WasAlreadyBeingDeclared) {
12975 S.SpecialMembersBeingDeclared.erase(D);
12976 S.popCodeSynthesisContext();
12977 }
12978 }
12979
12980 /// Are we already trying to declare this special member?
isAlreadyBeingDeclared__anonb2a824813611::DeclaringSpecialMember12981 bool isAlreadyBeingDeclared() const {
12982 return WasAlreadyBeingDeclared;
12983 }
12984 };
12985 }
12986
CheckImplicitSpecialMemberDeclaration(Scope * S,FunctionDecl * FD)12987 void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) {
12988 // Look up any existing declarations, but don't trigger declaration of all
12989 // implicit special members with this name.
12990 DeclarationName Name = FD->getDeclName();
12991 LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName,
12992 ForExternalRedeclaration);
12993 for (auto *D : FD->getParent()->lookup(Name))
12994 if (auto *Acceptable = R.getAcceptableDecl(D))
12995 R.addDecl(Acceptable);
12996 R.resolveKind();
12997 R.suppressDiagnostics();
12998
12999 CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/false);
13000 }
13001
setupImplicitSpecialMemberType(CXXMethodDecl * SpecialMem,QualType ResultTy,ArrayRef<QualType> Args)13002 void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
13003 QualType ResultTy,
13004 ArrayRef<QualType> Args) {
13005 // Build an exception specification pointing back at this constructor.
13006 FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem);
13007
13008 LangAS AS = getDefaultCXXMethodAddrSpace();
13009 if (AS != LangAS::Default) {
13010 EPI.TypeQuals.addAddressSpace(AS);
13011 }
13012
13013 auto QT = Context.getFunctionType(ResultTy, Args, EPI);
13014 SpecialMem->setType(QT);
13015 }
13016
DeclareImplicitDefaultConstructor(CXXRecordDecl * ClassDecl)13017 CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
13018 CXXRecordDecl *ClassDecl) {
13019 // C++ [class.ctor]p5:
13020 // A default constructor for a class X is a constructor of class X
13021 // that can be called without an argument. If there is no
13022 // user-declared constructor for class X, a default constructor is
13023 // implicitly declared. An implicitly-declared default constructor
13024 // is an inline public member of its class.
13025 assert(ClassDecl->needsImplicitDefaultConstructor() &&
13026 "Should not build implicit default constructor!");
13027
13028 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor);
13029 if (DSM.isAlreadyBeingDeclared())
13030 return nullptr;
13031
13032 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
13033 CXXDefaultConstructor,
13034 false);
13035
13036 // Create the actual constructor declaration.
13037 CanQualType ClassType
13038 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
13039 SourceLocation ClassLoc = ClassDecl->getLocation();
13040 DeclarationName Name
13041 = Context.DeclarationNames.getCXXConstructorName(ClassType);
13042 DeclarationNameInfo NameInfo(Name, ClassLoc);
13043 CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
13044 Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(),
13045 /*TInfo=*/nullptr, ExplicitSpecifier(),
13046 /*isInline=*/true, /*isImplicitlyDeclared=*/true,
13047 Constexpr ? ConstexprSpecKind::Constexpr
13048 : ConstexprSpecKind::Unspecified);
13049 DefaultCon->setAccess(AS_public);
13050 DefaultCon->setDefaulted();
13051
13052 if (getLangOpts().CUDA) {
13053 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor,
13054 DefaultCon,
13055 /* ConstRHS */ false,
13056 /* Diagnose */ false);
13057 }
13058
13059 setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, None);
13060
13061 // We don't need to use SpecialMemberIsTrivial here; triviality for default
13062 // constructors is easy to compute.
13063 DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
13064
13065 // Note that we have declared this constructor.
13066 ++getASTContext().NumImplicitDefaultConstructorsDeclared;
13067
13068 Scope *S = getScopeForContext(ClassDecl);
13069 CheckImplicitSpecialMemberDeclaration(S, DefaultCon);
13070
13071 if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
13072 SetDeclDeleted(DefaultCon, ClassLoc);
13073
13074 if (S)
13075 PushOnScopeChains(DefaultCon, S, false);
13076 ClassDecl->addDecl(DefaultCon);
13077
13078 return DefaultCon;
13079 }
13080
DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,CXXConstructorDecl * Constructor)13081 void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
13082 CXXConstructorDecl *Constructor) {
13083 assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
13084 !Constructor->doesThisDeclarationHaveABody() &&
13085 !Constructor->isDeleted()) &&
13086 "DefineImplicitDefaultConstructor - call it for implicit default ctor");
13087 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
13088 return;
13089
13090 CXXRecordDecl *ClassDecl = Constructor->getParent();
13091 assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
13092
13093 SynthesizedFunctionScope Scope(*this, Constructor);
13094
13095 // The exception specification is needed because we are defining the
13096 // function.
13097 ResolveExceptionSpec(CurrentLocation,
13098 Constructor->getType()->castAs<FunctionProtoType>());
13099 MarkVTableUsed(CurrentLocation, ClassDecl);
13100
13101 // Add a context note for diagnostics produced after this point.
13102 Scope.addContextNote(CurrentLocation);
13103
13104 if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) {
13105 Constructor->setInvalidDecl();
13106 return;
13107 }
13108
13109 SourceLocation Loc = Constructor->getEndLoc().isValid()
13110 ? Constructor->getEndLoc()
13111 : Constructor->getLocation();
13112 Constructor->setBody(new (Context) CompoundStmt(Loc));
13113 Constructor->markUsed(Context);
13114
13115 if (ASTMutationListener *L = getASTMutationListener()) {
13116 L->CompletedImplicitDefinition(Constructor);
13117 }
13118
13119 DiagnoseUninitializedFields(*this, Constructor);
13120 }
13121
ActOnFinishDelayedMemberInitializers(Decl * D)13122 void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
13123 // Perform any delayed checks on exception specifications.
13124 CheckDelayedMemberExceptionSpecs();
13125 }
13126
13127 /// Find or create the fake constructor we synthesize to model constructing an
13128 /// object of a derived class via a constructor of a base class.
13129 CXXConstructorDecl *
findInheritingConstructor(SourceLocation Loc,CXXConstructorDecl * BaseCtor,ConstructorUsingShadowDecl * Shadow)13130 Sema::findInheritingConstructor(SourceLocation Loc,
13131 CXXConstructorDecl *BaseCtor,
13132 ConstructorUsingShadowDecl *Shadow) {
13133 CXXRecordDecl *Derived = Shadow->getParent();
13134 SourceLocation UsingLoc = Shadow->getLocation();
13135
13136 // FIXME: Add a new kind of DeclarationName for an inherited constructor.
13137 // For now we use the name of the base class constructor as a member of the
13138 // derived class to indicate a (fake) inherited constructor name.
13139 DeclarationName Name = BaseCtor->getDeclName();
13140
13141 // Check to see if we already have a fake constructor for this inherited
13142 // constructor call.
13143 for (NamedDecl *Ctor : Derived->lookup(Name))
13144 if (declaresSameEntity(cast<CXXConstructorDecl>(Ctor)
13145 ->getInheritedConstructor()
13146 .getConstructor(),
13147 BaseCtor))
13148 return cast<CXXConstructorDecl>(Ctor);
13149
13150 DeclarationNameInfo NameInfo(Name, UsingLoc);
13151 TypeSourceInfo *TInfo =
13152 Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc);
13153 FunctionProtoTypeLoc ProtoLoc =
13154 TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>();
13155
13156 // Check the inherited constructor is valid and find the list of base classes
13157 // from which it was inherited.
13158 InheritedConstructorInfo ICI(*this, Loc, Shadow);
13159
13160 bool Constexpr =
13161 BaseCtor->isConstexpr() &&
13162 defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor,
13163 false, BaseCtor, &ICI);
13164
13165 CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create(
13166 Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo,
13167 BaseCtor->getExplicitSpecifier(), /*isInline=*/true,
13168 /*isImplicitlyDeclared=*/true,
13169 Constexpr ? BaseCtor->getConstexprKind() : ConstexprSpecKind::Unspecified,
13170 InheritedConstructor(Shadow, BaseCtor),
13171 BaseCtor->getTrailingRequiresClause());
13172 if (Shadow->isInvalidDecl())
13173 DerivedCtor->setInvalidDecl();
13174
13175 // Build an unevaluated exception specification for this fake constructor.
13176 const FunctionProtoType *FPT = TInfo->getType()->castAs<FunctionProtoType>();
13177 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
13178 EPI.ExceptionSpec.Type = EST_Unevaluated;
13179 EPI.ExceptionSpec.SourceDecl = DerivedCtor;
13180 DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(),
13181 FPT->getParamTypes(), EPI));
13182
13183 // Build the parameter declarations.
13184 SmallVector<ParmVarDecl *, 16> ParamDecls;
13185 for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) {
13186 TypeSourceInfo *TInfo =
13187 Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc);
13188 ParmVarDecl *PD = ParmVarDecl::Create(
13189 Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr,
13190 FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr);
13191 PD->setScopeInfo(0, I);
13192 PD->setImplicit();
13193 // Ensure attributes are propagated onto parameters (this matters for
13194 // format, pass_object_size, ...).
13195 mergeDeclAttributes(PD, BaseCtor->getParamDecl(I));
13196 ParamDecls.push_back(PD);
13197 ProtoLoc.setParam(I, PD);
13198 }
13199
13200 // Set up the new constructor.
13201 assert(!BaseCtor->isDeleted() && "should not use deleted constructor");
13202 DerivedCtor->setAccess(BaseCtor->getAccess());
13203 DerivedCtor->setParams(ParamDecls);
13204 Derived->addDecl(DerivedCtor);
13205
13206 if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI))
13207 SetDeclDeleted(DerivedCtor, UsingLoc);
13208
13209 return DerivedCtor;
13210 }
13211
NoteDeletedInheritingConstructor(CXXConstructorDecl * Ctor)13212 void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) {
13213 InheritedConstructorInfo ICI(*this, Ctor->getLocation(),
13214 Ctor->getInheritedConstructor().getShadowDecl());
13215 ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI,
13216 /*Diagnose*/true);
13217 }
13218
DefineInheritingConstructor(SourceLocation CurrentLocation,CXXConstructorDecl * Constructor)13219 void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation,
13220 CXXConstructorDecl *Constructor) {
13221 CXXRecordDecl *ClassDecl = Constructor->getParent();
13222 assert(Constructor->getInheritedConstructor() &&
13223 !Constructor->doesThisDeclarationHaveABody() &&
13224 !Constructor->isDeleted());
13225 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
13226 return;
13227
13228 // Initializations are performed "as if by a defaulted default constructor",
13229 // so enter the appropriate scope.
13230 SynthesizedFunctionScope Scope(*this, Constructor);
13231
13232 // The exception specification is needed because we are defining the
13233 // function.
13234 ResolveExceptionSpec(CurrentLocation,
13235 Constructor->getType()->castAs<FunctionProtoType>());
13236 MarkVTableUsed(CurrentLocation, ClassDecl);
13237
13238 // Add a context note for diagnostics produced after this point.
13239 Scope.addContextNote(CurrentLocation);
13240
13241 ConstructorUsingShadowDecl *Shadow =
13242 Constructor->getInheritedConstructor().getShadowDecl();
13243 CXXConstructorDecl *InheritedCtor =
13244 Constructor->getInheritedConstructor().getConstructor();
13245
13246 // [class.inhctor.init]p1:
13247 // initialization proceeds as if a defaulted default constructor is used to
13248 // initialize the D object and each base class subobject from which the
13249 // constructor was inherited
13250
13251 InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow);
13252 CXXRecordDecl *RD = Shadow->getParent();
13253 SourceLocation InitLoc = Shadow->getLocation();
13254
13255 // Build explicit initializers for all base classes from which the
13256 // constructor was inherited.
13257 SmallVector<CXXCtorInitializer*, 8> Inits;
13258 for (bool VBase : {false, true}) {
13259 for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) {
13260 if (B.isVirtual() != VBase)
13261 continue;
13262
13263 auto *BaseRD = B.getType()->getAsCXXRecordDecl();
13264 if (!BaseRD)
13265 continue;
13266
13267 auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor);
13268 if (!BaseCtor.first)
13269 continue;
13270
13271 MarkFunctionReferenced(CurrentLocation, BaseCtor.first);
13272 ExprResult Init = new (Context) CXXInheritedCtorInitExpr(
13273 InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second);
13274
13275 auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc);
13276 Inits.push_back(new (Context) CXXCtorInitializer(
13277 Context, TInfo, VBase, InitLoc, Init.get(), InitLoc,
13278 SourceLocation()));
13279 }
13280 }
13281
13282 // We now proceed as if for a defaulted default constructor, with the relevant
13283 // initializers replaced.
13284
13285 if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) {
13286 Constructor->setInvalidDecl();
13287 return;
13288 }
13289
13290 Constructor->setBody(new (Context) CompoundStmt(InitLoc));
13291 Constructor->markUsed(Context);
13292
13293 if (ASTMutationListener *L = getASTMutationListener()) {
13294 L->CompletedImplicitDefinition(Constructor);
13295 }
13296
13297 DiagnoseUninitializedFields(*this, Constructor);
13298 }
13299
DeclareImplicitDestructor(CXXRecordDecl * ClassDecl)13300 CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
13301 // C++ [class.dtor]p2:
13302 // If a class has no user-declared destructor, a destructor is
13303 // declared implicitly. An implicitly-declared destructor is an
13304 // inline public member of its class.
13305 assert(ClassDecl->needsImplicitDestructor());
13306
13307 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor);
13308 if (DSM.isAlreadyBeingDeclared())
13309 return nullptr;
13310
13311 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
13312 CXXDestructor,
13313 false);
13314
13315 // Create the actual destructor declaration.
13316 CanQualType ClassType
13317 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
13318 SourceLocation ClassLoc = ClassDecl->getLocation();
13319 DeclarationName Name
13320 = Context.DeclarationNames.getCXXDestructorName(ClassType);
13321 DeclarationNameInfo NameInfo(Name, ClassLoc);
13322 CXXDestructorDecl *Destructor =
13323 CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
13324 QualType(), nullptr, /*isInline=*/true,
13325 /*isImplicitlyDeclared=*/true,
13326 Constexpr ? ConstexprSpecKind::Constexpr
13327 : ConstexprSpecKind::Unspecified);
13328 Destructor->setAccess(AS_public);
13329 Destructor->setDefaulted();
13330
13331 if (getLangOpts().CUDA) {
13332 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor,
13333 Destructor,
13334 /* ConstRHS */ false,
13335 /* Diagnose */ false);
13336 }
13337
13338 setupImplicitSpecialMemberType(Destructor, Context.VoidTy, None);
13339
13340 // We don't need to use SpecialMemberIsTrivial here; triviality for
13341 // destructors is easy to compute.
13342 Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
13343 Destructor->setTrivialForCall(ClassDecl->hasAttr<TrivialABIAttr>() ||
13344 ClassDecl->hasTrivialDestructorForCall());
13345
13346 // Note that we have declared this destructor.
13347 ++getASTContext().NumImplicitDestructorsDeclared;
13348
13349 Scope *S = getScopeForContext(ClassDecl);
13350 CheckImplicitSpecialMemberDeclaration(S, Destructor);
13351
13352 // We can't check whether an implicit destructor is deleted before we complete
13353 // the definition of the class, because its validity depends on the alignment
13354 // of the class. We'll check this from ActOnFields once the class is complete.
13355 if (ClassDecl->isCompleteDefinition() &&
13356 ShouldDeleteSpecialMember(Destructor, CXXDestructor))
13357 SetDeclDeleted(Destructor, ClassLoc);
13358
13359 // Introduce this destructor into its scope.
13360 if (S)
13361 PushOnScopeChains(Destructor, S, false);
13362 ClassDecl->addDecl(Destructor);
13363
13364 return Destructor;
13365 }
13366
DefineImplicitDestructor(SourceLocation CurrentLocation,CXXDestructorDecl * Destructor)13367 void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
13368 CXXDestructorDecl *Destructor) {
13369 assert((Destructor->isDefaulted() &&
13370 !Destructor->doesThisDeclarationHaveABody() &&
13371 !Destructor->isDeleted()) &&
13372 "DefineImplicitDestructor - call it for implicit default dtor");
13373 if (Destructor->willHaveBody() || Destructor->isInvalidDecl())
13374 return;
13375
13376 CXXRecordDecl *ClassDecl = Destructor->getParent();
13377 assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
13378
13379 SynthesizedFunctionScope Scope(*this, Destructor);
13380
13381 // The exception specification is needed because we are defining the
13382 // function.
13383 ResolveExceptionSpec(CurrentLocation,
13384 Destructor->getType()->castAs<FunctionProtoType>());
13385 MarkVTableUsed(CurrentLocation, ClassDecl);
13386
13387 // Add a context note for diagnostics produced after this point.
13388 Scope.addContextNote(CurrentLocation);
13389
13390 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
13391 Destructor->getParent());
13392
13393 if (CheckDestructor(Destructor)) {
13394 Destructor->setInvalidDecl();
13395 return;
13396 }
13397
13398 SourceLocation Loc = Destructor->getEndLoc().isValid()
13399 ? Destructor->getEndLoc()
13400 : Destructor->getLocation();
13401 Destructor->setBody(new (Context) CompoundStmt(Loc));
13402 Destructor->markUsed(Context);
13403
13404 if (ASTMutationListener *L = getASTMutationListener()) {
13405 L->CompletedImplicitDefinition(Destructor);
13406 }
13407 }
13408
CheckCompleteDestructorVariant(SourceLocation CurrentLocation,CXXDestructorDecl * Destructor)13409 void Sema::CheckCompleteDestructorVariant(SourceLocation CurrentLocation,
13410 CXXDestructorDecl *Destructor) {
13411 if (Destructor->isInvalidDecl())
13412 return;
13413
13414 CXXRecordDecl *ClassDecl = Destructor->getParent();
13415 assert(Context.getTargetInfo().getCXXABI().isMicrosoft() &&
13416 "implicit complete dtors unneeded outside MS ABI");
13417 assert(ClassDecl->getNumVBases() > 0 &&
13418 "complete dtor only exists for classes with vbases");
13419
13420 SynthesizedFunctionScope Scope(*this, Destructor);
13421
13422 // Add a context note for diagnostics produced after this point.
13423 Scope.addContextNote(CurrentLocation);
13424
13425 MarkVirtualBaseDestructorsReferenced(Destructor->getLocation(), ClassDecl);
13426 }
13427
13428 /// Perform any semantic analysis which needs to be delayed until all
13429 /// pending class member declarations have been parsed.
ActOnFinishCXXMemberDecls()13430 void Sema::ActOnFinishCXXMemberDecls() {
13431 // If the context is an invalid C++ class, just suppress these checks.
13432 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) {
13433 if (Record->isInvalidDecl()) {
13434 DelayedOverridingExceptionSpecChecks.clear();
13435 DelayedEquivalentExceptionSpecChecks.clear();
13436 return;
13437 }
13438 checkForMultipleExportedDefaultConstructors(*this, Record);
13439 }
13440 }
13441
ActOnFinishCXXNonNestedClass()13442 void Sema::ActOnFinishCXXNonNestedClass() {
13443 referenceDLLExportedClassMethods();
13444
13445 if (!DelayedDllExportMemberFunctions.empty()) {
13446 SmallVector<CXXMethodDecl*, 4> WorkList;
13447 std::swap(DelayedDllExportMemberFunctions, WorkList);
13448 for (CXXMethodDecl *M : WorkList) {
13449 DefineDefaultedFunction(*this, M, M->getLocation());
13450
13451 // Pass the method to the consumer to get emitted. This is not necessary
13452 // for explicit instantiation definitions, as they will get emitted
13453 // anyway.
13454 if (M->getParent()->getTemplateSpecializationKind() !=
13455 TSK_ExplicitInstantiationDefinition)
13456 ActOnFinishInlineFunctionDef(M);
13457 }
13458 }
13459 }
13460
referenceDLLExportedClassMethods()13461 void Sema::referenceDLLExportedClassMethods() {
13462 if (!DelayedDllExportClasses.empty()) {
13463 // Calling ReferenceDllExportedMembers might cause the current function to
13464 // be called again, so use a local copy of DelayedDllExportClasses.
13465 SmallVector<CXXRecordDecl *, 4> WorkList;
13466 std::swap(DelayedDllExportClasses, WorkList);
13467 for (CXXRecordDecl *Class : WorkList)
13468 ReferenceDllExportedMembers(*this, Class);
13469 }
13470 }
13471
AdjustDestructorExceptionSpec(CXXDestructorDecl * Destructor)13472 void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) {
13473 assert(getLangOpts().CPlusPlus11 &&
13474 "adjusting dtor exception specs was introduced in c++11");
13475
13476 if (Destructor->isDependentContext())
13477 return;
13478
13479 // C++11 [class.dtor]p3:
13480 // A declaration of a destructor that does not have an exception-
13481 // specification is implicitly considered to have the same exception-
13482 // specification as an implicit declaration.
13483 const auto *DtorType = Destructor->getType()->castAs<FunctionProtoType>();
13484 if (DtorType->hasExceptionSpec())
13485 return;
13486
13487 // Replace the destructor's type, building off the existing one. Fortunately,
13488 // the only thing of interest in the destructor type is its extended info.
13489 // The return and arguments are fixed.
13490 FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo();
13491 EPI.ExceptionSpec.Type = EST_Unevaluated;
13492 EPI.ExceptionSpec.SourceDecl = Destructor;
13493 Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI));
13494
13495 // FIXME: If the destructor has a body that could throw, and the newly created
13496 // spec doesn't allow exceptions, we should emit a warning, because this
13497 // change in behavior can break conforming C++03 programs at runtime.
13498 // However, we don't have a body or an exception specification yet, so it
13499 // needs to be done somewhere else.
13500 }
13501
13502 namespace {
13503 /// An abstract base class for all helper classes used in building the
13504 // copy/move operators. These classes serve as factory functions and help us
13505 // avoid using the same Expr* in the AST twice.
13506 class ExprBuilder {
13507 ExprBuilder(const ExprBuilder&) = delete;
13508 ExprBuilder &operator=(const ExprBuilder&) = delete;
13509
13510 protected:
assertNotNull(Expr * E)13511 static Expr *assertNotNull(Expr *E) {
13512 assert(E && "Expression construction must not fail.");
13513 return E;
13514 }
13515
13516 public:
ExprBuilder()13517 ExprBuilder() {}
~ExprBuilder()13518 virtual ~ExprBuilder() {}
13519
13520 virtual Expr *build(Sema &S, SourceLocation Loc) const = 0;
13521 };
13522
13523 class RefBuilder: public ExprBuilder {
13524 VarDecl *Var;
13525 QualType VarType;
13526
13527 public:
build(Sema & S,SourceLocation Loc) const13528 Expr *build(Sema &S, SourceLocation Loc) const override {
13529 return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc));
13530 }
13531
RefBuilder(VarDecl * Var,QualType VarType)13532 RefBuilder(VarDecl *Var, QualType VarType)
13533 : Var(Var), VarType(VarType) {}
13534 };
13535
13536 class ThisBuilder: public ExprBuilder {
13537 public:
build(Sema & S,SourceLocation Loc) const13538 Expr *build(Sema &S, SourceLocation Loc) const override {
13539 return assertNotNull(S.ActOnCXXThis(Loc).getAs<Expr>());
13540 }
13541 };
13542
13543 class CastBuilder: public ExprBuilder {
13544 const ExprBuilder &Builder;
13545 QualType Type;
13546 ExprValueKind Kind;
13547 const CXXCastPath &Path;
13548
13549 public:
build(Sema & S,SourceLocation Loc) const13550 Expr *build(Sema &S, SourceLocation Loc) const override {
13551 return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type,
13552 CK_UncheckedDerivedToBase, Kind,
13553 &Path).get());
13554 }
13555
CastBuilder(const ExprBuilder & Builder,QualType Type,ExprValueKind Kind,const CXXCastPath & Path)13556 CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind,
13557 const CXXCastPath &Path)
13558 : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {}
13559 };
13560
13561 class DerefBuilder: public ExprBuilder {
13562 const ExprBuilder &Builder;
13563
13564 public:
build(Sema & S,SourceLocation Loc) const13565 Expr *build(Sema &S, SourceLocation Loc) const override {
13566 return assertNotNull(
13567 S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get());
13568 }
13569
DerefBuilder(const ExprBuilder & Builder)13570 DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13571 };
13572
13573 class MemberBuilder: public ExprBuilder {
13574 const ExprBuilder &Builder;
13575 QualType Type;
13576 CXXScopeSpec SS;
13577 bool IsArrow;
13578 LookupResult &MemberLookup;
13579
13580 public:
build(Sema & S,SourceLocation Loc) const13581 Expr *build(Sema &S, SourceLocation Loc) const override {
13582 return assertNotNull(S.BuildMemberReferenceExpr(
13583 Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(),
13584 nullptr, MemberLookup, nullptr, nullptr).get());
13585 }
13586
MemberBuilder(const ExprBuilder & Builder,QualType Type,bool IsArrow,LookupResult & MemberLookup)13587 MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow,
13588 LookupResult &MemberLookup)
13589 : Builder(Builder), Type(Type), IsArrow(IsArrow),
13590 MemberLookup(MemberLookup) {}
13591 };
13592
13593 class MoveCastBuilder: public ExprBuilder {
13594 const ExprBuilder &Builder;
13595
13596 public:
build(Sema & S,SourceLocation Loc) const13597 Expr *build(Sema &S, SourceLocation Loc) const override {
13598 return assertNotNull(CastForMoving(S, Builder.build(S, Loc)));
13599 }
13600
MoveCastBuilder(const ExprBuilder & Builder)13601 MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13602 };
13603
13604 class LvalueConvBuilder: public ExprBuilder {
13605 const ExprBuilder &Builder;
13606
13607 public:
build(Sema & S,SourceLocation Loc) const13608 Expr *build(Sema &S, SourceLocation Loc) const override {
13609 return assertNotNull(
13610 S.DefaultLvalueConversion(Builder.build(S, Loc)).get());
13611 }
13612
LvalueConvBuilder(const ExprBuilder & Builder)13613 LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13614 };
13615
13616 class SubscriptBuilder: public ExprBuilder {
13617 const ExprBuilder &Base;
13618 const ExprBuilder &Index;
13619
13620 public:
build(Sema & S,SourceLocation Loc) const13621 Expr *build(Sema &S, SourceLocation Loc) const override {
13622 return assertNotNull(S.CreateBuiltinArraySubscriptExpr(
13623 Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get());
13624 }
13625
SubscriptBuilder(const ExprBuilder & Base,const ExprBuilder & Index)13626 SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index)
13627 : Base(Base), Index(Index) {}
13628 };
13629
13630 } // end anonymous namespace
13631
13632 /// When generating a defaulted copy or move assignment operator, if a field
13633 /// should be copied with __builtin_memcpy rather than via explicit assignments,
13634 /// do so. This optimization only applies for arrays of scalars, and for arrays
13635 /// of class type where the selected copy/move-assignment operator is trivial.
13636 static StmtResult
buildMemcpyForAssignmentOp(Sema & S,SourceLocation Loc,QualType T,const ExprBuilder & ToB,const ExprBuilder & FromB)13637 buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T,
13638 const ExprBuilder &ToB, const ExprBuilder &FromB) {
13639 // Compute the size of the memory buffer to be copied.
13640 QualType SizeType = S.Context.getSizeType();
13641 llvm::APInt Size(S.Context.getTypeSize(SizeType),
13642 S.Context.getTypeSizeInChars(T).getQuantity());
13643
13644 // Take the address of the field references for "from" and "to". We
13645 // directly construct UnaryOperators here because semantic analysis
13646 // does not permit us to take the address of an xvalue.
13647 Expr *From = FromB.build(S, Loc);
13648 From = UnaryOperator::Create(
13649 S.Context, From, UO_AddrOf, S.Context.getPointerType(From->getType()),
13650 VK_RValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides());
13651 Expr *To = ToB.build(S, Loc);
13652 To = UnaryOperator::Create(
13653 S.Context, To, UO_AddrOf, S.Context.getPointerType(To->getType()),
13654 VK_RValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides());
13655
13656 const Type *E = T->getBaseElementTypeUnsafe();
13657 bool NeedsCollectableMemCpy =
13658 E->isRecordType() &&
13659 E->castAs<RecordType>()->getDecl()->hasObjectMember();
13660
13661 // Create a reference to the __builtin_objc_memmove_collectable function
13662 StringRef MemCpyName = NeedsCollectableMemCpy ?
13663 "__builtin_objc_memmove_collectable" :
13664 "__builtin_memcpy";
13665 LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc,
13666 Sema::LookupOrdinaryName);
13667 S.LookupName(R, S.TUScope, true);
13668
13669 FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>();
13670 if (!MemCpy)
13671 // Something went horribly wrong earlier, and we will have complained
13672 // about it.
13673 return StmtError();
13674
13675 ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy,
13676 VK_RValue, Loc, nullptr);
13677 assert(MemCpyRef.isUsable() && "Builtin reference cannot fail");
13678
13679 Expr *CallArgs[] = {
13680 To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc)
13681 };
13682 ExprResult Call = S.BuildCallExpr(/*Scope=*/nullptr, MemCpyRef.get(),
13683 Loc, CallArgs, Loc);
13684
13685 assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
13686 return Call.getAs<Stmt>();
13687 }
13688
13689 /// Builds a statement that copies/moves the given entity from \p From to
13690 /// \c To.
13691 ///
13692 /// This routine is used to copy/move the members of a class with an
13693 /// implicitly-declared copy/move assignment operator. When the entities being
13694 /// copied are arrays, this routine builds for loops to copy them.
13695 ///
13696 /// \param S The Sema object used for type-checking.
13697 ///
13698 /// \param Loc The location where the implicit copy/move is being generated.
13699 ///
13700 /// \param T The type of the expressions being copied/moved. Both expressions
13701 /// must have this type.
13702 ///
13703 /// \param To The expression we are copying/moving to.
13704 ///
13705 /// \param From The expression we are copying/moving from.
13706 ///
13707 /// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
13708 /// Otherwise, it's a non-static member subobject.
13709 ///
13710 /// \param Copying Whether we're copying or moving.
13711 ///
13712 /// \param Depth Internal parameter recording the depth of the recursion.
13713 ///
13714 /// \returns A statement or a loop that copies the expressions, or StmtResult(0)
13715 /// if a memcpy should be used instead.
13716 static StmtResult
buildSingleCopyAssignRecursively(Sema & S,SourceLocation Loc,QualType T,const ExprBuilder & To,const ExprBuilder & From,bool CopyingBaseSubobject,bool Copying,unsigned Depth=0)13717 buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T,
13718 const ExprBuilder &To, const ExprBuilder &From,
13719 bool CopyingBaseSubobject, bool Copying,
13720 unsigned Depth = 0) {
13721 // C++11 [class.copy]p28:
13722 // Each subobject is assigned in the manner appropriate to its type:
13723 //
13724 // - if the subobject is of class type, as if by a call to operator= with
13725 // the subobject as the object expression and the corresponding
13726 // subobject of x as a single function argument (as if by explicit
13727 // qualification; that is, ignoring any possible virtual overriding
13728 // functions in more derived classes);
13729 //
13730 // C++03 [class.copy]p13:
13731 // - if the subobject is of class type, the copy assignment operator for
13732 // the class is used (as if by explicit qualification; that is,
13733 // ignoring any possible virtual overriding functions in more derived
13734 // classes);
13735 if (const RecordType *RecordTy = T->getAs<RecordType>()) {
13736 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
13737
13738 // Look for operator=.
13739 DeclarationName Name
13740 = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
13741 LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
13742 S.LookupQualifiedName(OpLookup, ClassDecl, false);
13743
13744 // Prior to C++11, filter out any result that isn't a copy/move-assignment
13745 // operator.
13746 if (!S.getLangOpts().CPlusPlus11) {
13747 LookupResult::Filter F = OpLookup.makeFilter();
13748 while (F.hasNext()) {
13749 NamedDecl *D = F.next();
13750 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
13751 if (Method->isCopyAssignmentOperator() ||
13752 (!Copying && Method->isMoveAssignmentOperator()))
13753 continue;
13754
13755 F.erase();
13756 }
13757 F.done();
13758 }
13759
13760 // Suppress the protected check (C++ [class.protected]) for each of the
13761 // assignment operators we found. This strange dance is required when
13762 // we're assigning via a base classes's copy-assignment operator. To
13763 // ensure that we're getting the right base class subobject (without
13764 // ambiguities), we need to cast "this" to that subobject type; to
13765 // ensure that we don't go through the virtual call mechanism, we need
13766 // to qualify the operator= name with the base class (see below). However,
13767 // this means that if the base class has a protected copy assignment
13768 // operator, the protected member access check will fail. So, we
13769 // rewrite "protected" access to "public" access in this case, since we
13770 // know by construction that we're calling from a derived class.
13771 if (CopyingBaseSubobject) {
13772 for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
13773 L != LEnd; ++L) {
13774 if (L.getAccess() == AS_protected)
13775 L.setAccess(AS_public);
13776 }
13777 }
13778
13779 // Create the nested-name-specifier that will be used to qualify the
13780 // reference to operator=; this is required to suppress the virtual
13781 // call mechanism.
13782 CXXScopeSpec SS;
13783 const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
13784 SS.MakeTrivial(S.Context,
13785 NestedNameSpecifier::Create(S.Context, nullptr, false,
13786 CanonicalT),
13787 Loc);
13788
13789 // Create the reference to operator=.
13790 ExprResult OpEqualRef
13791 = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*IsArrow=*/false,
13792 SS, /*TemplateKWLoc=*/SourceLocation(),
13793 /*FirstQualifierInScope=*/nullptr,
13794 OpLookup,
13795 /*TemplateArgs=*/nullptr, /*S*/nullptr,
13796 /*SuppressQualifierCheck=*/true);
13797 if (OpEqualRef.isInvalid())
13798 return StmtError();
13799
13800 // Build the call to the assignment operator.
13801
13802 Expr *FromInst = From.build(S, Loc);
13803 ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr,
13804 OpEqualRef.getAs<Expr>(),
13805 Loc, FromInst, Loc);
13806 if (Call.isInvalid())
13807 return StmtError();
13808
13809 // If we built a call to a trivial 'operator=' while copying an array,
13810 // bail out. We'll replace the whole shebang with a memcpy.
13811 CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(Call.get());
13812 if (CE && CE->getMethodDecl()->isTrivial() && Depth)
13813 return StmtResult((Stmt*)nullptr);
13814
13815 // Convert to an expression-statement, and clean up any produced
13816 // temporaries.
13817 return S.ActOnExprStmt(Call);
13818 }
13819
13820 // - if the subobject is of scalar type, the built-in assignment
13821 // operator is used.
13822 const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
13823 if (!ArrayTy) {
13824 ExprResult Assignment = S.CreateBuiltinBinOp(
13825 Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc));
13826 if (Assignment.isInvalid())
13827 return StmtError();
13828 return S.ActOnExprStmt(Assignment);
13829 }
13830
13831 // - if the subobject is an array, each element is assigned, in the
13832 // manner appropriate to the element type;
13833
13834 // Construct a loop over the array bounds, e.g.,
13835 //
13836 // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
13837 //
13838 // that will copy each of the array elements.
13839 QualType SizeType = S.Context.getSizeType();
13840
13841 // Create the iteration variable.
13842 IdentifierInfo *IterationVarName = nullptr;
13843 {
13844 SmallString<8> Str;
13845 llvm::raw_svector_ostream OS(Str);
13846 OS << "__i" << Depth;
13847 IterationVarName = &S.Context.Idents.get(OS.str());
13848 }
13849 VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
13850 IterationVarName, SizeType,
13851 S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
13852 SC_None);
13853
13854 // Initialize the iteration variable to zero.
13855 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
13856 IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
13857
13858 // Creates a reference to the iteration variable.
13859 RefBuilder IterationVarRef(IterationVar, SizeType);
13860 LvalueConvBuilder IterationVarRefRVal(IterationVarRef);
13861
13862 // Create the DeclStmt that holds the iteration variable.
13863 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
13864
13865 // Subscript the "from" and "to" expressions with the iteration variable.
13866 SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal);
13867 MoveCastBuilder FromIndexMove(FromIndexCopy);
13868 const ExprBuilder *FromIndex;
13869 if (Copying)
13870 FromIndex = &FromIndexCopy;
13871 else
13872 FromIndex = &FromIndexMove;
13873
13874 SubscriptBuilder ToIndex(To, IterationVarRefRVal);
13875
13876 // Build the copy/move for an individual element of the array.
13877 StmtResult Copy =
13878 buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(),
13879 ToIndex, *FromIndex, CopyingBaseSubobject,
13880 Copying, Depth + 1);
13881 // Bail out if copying fails or if we determined that we should use memcpy.
13882 if (Copy.isInvalid() || !Copy.get())
13883 return Copy;
13884
13885 // Create the comparison against the array bound.
13886 llvm::APInt Upper
13887 = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
13888 Expr *Comparison = BinaryOperator::Create(
13889 S.Context, IterationVarRefRVal.build(S, Loc),
13890 IntegerLiteral::Create(S.Context, Upper, SizeType, Loc), BO_NE,
13891 S.Context.BoolTy, VK_RValue, OK_Ordinary, Loc, S.CurFPFeatureOverrides());
13892
13893 // Create the pre-increment of the iteration variable. We can determine
13894 // whether the increment will overflow based on the value of the array
13895 // bound.
13896 Expr *Increment = UnaryOperator::Create(
13897 S.Context, IterationVarRef.build(S, Loc), UO_PreInc, SizeType, VK_LValue,
13898 OK_Ordinary, Loc, Upper.isMaxValue(), S.CurFPFeatureOverrides());
13899
13900 // Construct the loop that copies all elements of this array.
13901 return S.ActOnForStmt(
13902 Loc, Loc, InitStmt,
13903 S.ActOnCondition(nullptr, Loc, Comparison, Sema::ConditionKind::Boolean),
13904 S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get());
13905 }
13906
13907 static StmtResult
buildSingleCopyAssign(Sema & S,SourceLocation Loc,QualType T,const ExprBuilder & To,const ExprBuilder & From,bool CopyingBaseSubobject,bool Copying)13908 buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
13909 const ExprBuilder &To, const ExprBuilder &From,
13910 bool CopyingBaseSubobject, bool Copying) {
13911 // Maybe we should use a memcpy?
13912 if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() &&
13913 T.isTriviallyCopyableType(S.Context))
13914 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
13915
13916 StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From,
13917 CopyingBaseSubobject,
13918 Copying, 0));
13919
13920 // If we ended up picking a trivial assignment operator for an array of a
13921 // non-trivially-copyable class type, just emit a memcpy.
13922 if (!Result.isInvalid() && !Result.get())
13923 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
13924
13925 return Result;
13926 }
13927
DeclareImplicitCopyAssignment(CXXRecordDecl * ClassDecl)13928 CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
13929 // Note: The following rules are largely analoguous to the copy
13930 // constructor rules. Note that virtual bases are not taken into account
13931 // for determining the argument type of the operator. Note also that
13932 // operators taking an object instead of a reference are allowed.
13933 assert(ClassDecl->needsImplicitCopyAssignment());
13934
13935 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment);
13936 if (DSM.isAlreadyBeingDeclared())
13937 return nullptr;
13938
13939 QualType ArgType = Context.getTypeDeclType(ClassDecl);
13940 LangAS AS = getDefaultCXXMethodAddrSpace();
13941 if (AS != LangAS::Default)
13942 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
13943 QualType RetType = Context.getLValueReferenceType(ArgType);
13944 bool Const = ClassDecl->implicitCopyAssignmentHasConstParam();
13945 if (Const)
13946 ArgType = ArgType.withConst();
13947
13948 ArgType = Context.getLValueReferenceType(ArgType);
13949
13950 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
13951 CXXCopyAssignment,
13952 Const);
13953
13954 // An implicitly-declared copy assignment operator is an inline public
13955 // member of its class.
13956 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
13957 SourceLocation ClassLoc = ClassDecl->getLocation();
13958 DeclarationNameInfo NameInfo(Name, ClassLoc);
13959 CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create(
13960 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
13961 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
13962 /*isInline=*/true,
13963 Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified,
13964 SourceLocation());
13965 CopyAssignment->setAccess(AS_public);
13966 CopyAssignment->setDefaulted();
13967 CopyAssignment->setImplicit();
13968
13969 if (getLangOpts().CUDA) {
13970 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment,
13971 CopyAssignment,
13972 /* ConstRHS */ Const,
13973 /* Diagnose */ false);
13974 }
13975
13976 setupImplicitSpecialMemberType(CopyAssignment, RetType, ArgType);
13977
13978 // Add the parameter to the operator.
13979 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
13980 ClassLoc, ClassLoc,
13981 /*Id=*/nullptr, ArgType,
13982 /*TInfo=*/nullptr, SC_None,
13983 nullptr);
13984 CopyAssignment->setParams(FromParam);
13985
13986 CopyAssignment->setTrivial(
13987 ClassDecl->needsOverloadResolutionForCopyAssignment()
13988 ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment)
13989 : ClassDecl->hasTrivialCopyAssignment());
13990
13991 // Note that we have added this copy-assignment operator.
13992 ++getASTContext().NumImplicitCopyAssignmentOperatorsDeclared;
13993
13994 Scope *S = getScopeForContext(ClassDecl);
13995 CheckImplicitSpecialMemberDeclaration(S, CopyAssignment);
13996
13997 if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment)) {
13998 ClassDecl->setImplicitCopyAssignmentIsDeleted();
13999 SetDeclDeleted(CopyAssignment, ClassLoc);
14000 }
14001
14002 if (S)
14003 PushOnScopeChains(CopyAssignment, S, false);
14004 ClassDecl->addDecl(CopyAssignment);
14005
14006 return CopyAssignment;
14007 }
14008
14009 /// Diagnose an implicit copy operation for a class which is odr-used, but
14010 /// which is deprecated because the class has a user-declared copy constructor,
14011 /// copy assignment operator, or destructor.
diagnoseDeprecatedCopyOperation(Sema & S,CXXMethodDecl * CopyOp)14012 static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp) {
14013 assert(CopyOp->isImplicit());
14014
14015 CXXRecordDecl *RD = CopyOp->getParent();
14016 CXXMethodDecl *UserDeclaredOperation = nullptr;
14017
14018 // In Microsoft mode, assignment operations don't affect constructors and
14019 // vice versa.
14020 if (RD->hasUserDeclaredDestructor()) {
14021 UserDeclaredOperation = RD->getDestructor();
14022 } else if (!isa<CXXConstructorDecl>(CopyOp) &&
14023 RD->hasUserDeclaredCopyConstructor() &&
14024 !S.getLangOpts().MSVCCompat) {
14025 // Find any user-declared copy constructor.
14026 for (auto *I : RD->ctors()) {
14027 if (I->isCopyConstructor()) {
14028 UserDeclaredOperation = I;
14029 break;
14030 }
14031 }
14032 assert(UserDeclaredOperation);
14033 } else if (isa<CXXConstructorDecl>(CopyOp) &&
14034 RD->hasUserDeclaredCopyAssignment() &&
14035 !S.getLangOpts().MSVCCompat) {
14036 // Find any user-declared move assignment operator.
14037 for (auto *I : RD->methods()) {
14038 if (I->isCopyAssignmentOperator()) {
14039 UserDeclaredOperation = I;
14040 break;
14041 }
14042 }
14043 assert(UserDeclaredOperation);
14044 }
14045
14046 if (UserDeclaredOperation) {
14047 bool UDOIsUserProvided = UserDeclaredOperation->isUserProvided();
14048 bool UDOIsDestructor = isa<CXXDestructorDecl>(UserDeclaredOperation);
14049 bool IsCopyAssignment = !isa<CXXConstructorDecl>(CopyOp);
14050 unsigned DiagID =
14051 (UDOIsUserProvided && UDOIsDestructor)
14052 ? diag::warn_deprecated_copy_with_user_provided_dtor
14053 : (UDOIsUserProvided && !UDOIsDestructor)
14054 ? diag::warn_deprecated_copy_with_user_provided_copy
14055 : (!UDOIsUserProvided && UDOIsDestructor)
14056 ? diag::warn_deprecated_copy_with_dtor
14057 : diag::warn_deprecated_copy;
14058 S.Diag(UserDeclaredOperation->getLocation(), DiagID)
14059 << RD << IsCopyAssignment;
14060 }
14061 }
14062
DefineImplicitCopyAssignment(SourceLocation CurrentLocation,CXXMethodDecl * CopyAssignOperator)14063 void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
14064 CXXMethodDecl *CopyAssignOperator) {
14065 assert((CopyAssignOperator->isDefaulted() &&
14066 CopyAssignOperator->isOverloadedOperator() &&
14067 CopyAssignOperator->getOverloadedOperator() == OO_Equal &&
14068 !CopyAssignOperator->doesThisDeclarationHaveABody() &&
14069 !CopyAssignOperator->isDeleted()) &&
14070 "DefineImplicitCopyAssignment called for wrong function");
14071 if (CopyAssignOperator->willHaveBody() || CopyAssignOperator->isInvalidDecl())
14072 return;
14073
14074 CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
14075 if (ClassDecl->isInvalidDecl()) {
14076 CopyAssignOperator->setInvalidDecl();
14077 return;
14078 }
14079
14080 SynthesizedFunctionScope Scope(*this, CopyAssignOperator);
14081
14082 // The exception specification is needed because we are defining the
14083 // function.
14084 ResolveExceptionSpec(CurrentLocation,
14085 CopyAssignOperator->getType()->castAs<FunctionProtoType>());
14086
14087 // Add a context note for diagnostics produced after this point.
14088 Scope.addContextNote(CurrentLocation);
14089
14090 // C++11 [class.copy]p18:
14091 // The [definition of an implicitly declared copy assignment operator] is
14092 // deprecated if the class has a user-declared copy constructor or a
14093 // user-declared destructor.
14094 if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit())
14095 diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator);
14096
14097 // C++0x [class.copy]p30:
14098 // The implicitly-defined or explicitly-defaulted copy assignment operator
14099 // for a non-union class X performs memberwise copy assignment of its
14100 // subobjects. The direct base classes of X are assigned first, in the
14101 // order of their declaration in the base-specifier-list, and then the
14102 // immediate non-static data members of X are assigned, in the order in
14103 // which they were declared in the class definition.
14104
14105 // The statements that form the synthesized function body.
14106 SmallVector<Stmt*, 8> Statements;
14107
14108 // The parameter for the "other" object, which we are copying from.
14109 ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
14110 Qualifiers OtherQuals = Other->getType().getQualifiers();
14111 QualType OtherRefType = Other->getType();
14112 if (const LValueReferenceType *OtherRef
14113 = OtherRefType->getAs<LValueReferenceType>()) {
14114 OtherRefType = OtherRef->getPointeeType();
14115 OtherQuals = OtherRefType.getQualifiers();
14116 }
14117
14118 // Our location for everything implicitly-generated.
14119 SourceLocation Loc = CopyAssignOperator->getEndLoc().isValid()
14120 ? CopyAssignOperator->getEndLoc()
14121 : CopyAssignOperator->getLocation();
14122
14123 // Builds a DeclRefExpr for the "other" object.
14124 RefBuilder OtherRef(Other, OtherRefType);
14125
14126 // Builds the "this" pointer.
14127 ThisBuilder This;
14128
14129 // Assign base classes.
14130 bool Invalid = false;
14131 for (auto &Base : ClassDecl->bases()) {
14132 // Form the assignment:
14133 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
14134 QualType BaseType = Base.getType().getUnqualifiedType();
14135 if (!BaseType->isRecordType()) {
14136 Invalid = true;
14137 continue;
14138 }
14139
14140 CXXCastPath BasePath;
14141 BasePath.push_back(&Base);
14142
14143 // Construct the "from" expression, which is an implicit cast to the
14144 // appropriately-qualified base type.
14145 CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals),
14146 VK_LValue, BasePath);
14147
14148 // Dereference "this".
14149 DerefBuilder DerefThis(This);
14150 CastBuilder To(DerefThis,
14151 Context.getQualifiedType(
14152 BaseType, CopyAssignOperator->getMethodQualifiers()),
14153 VK_LValue, BasePath);
14154
14155 // Build the copy.
14156 StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType,
14157 To, From,
14158 /*CopyingBaseSubobject=*/true,
14159 /*Copying=*/true);
14160 if (Copy.isInvalid()) {
14161 CopyAssignOperator->setInvalidDecl();
14162 return;
14163 }
14164
14165 // Success! Record the copy.
14166 Statements.push_back(Copy.getAs<Expr>());
14167 }
14168
14169 // Assign non-static members.
14170 for (auto *Field : ClassDecl->fields()) {
14171 // FIXME: We should form some kind of AST representation for the implied
14172 // memcpy in a union copy operation.
14173 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
14174 continue;
14175
14176 if (Field->isInvalidDecl()) {
14177 Invalid = true;
14178 continue;
14179 }
14180
14181 // Check for members of reference type; we can't copy those.
14182 if (Field->getType()->isReferenceType()) {
14183 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14184 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
14185 Diag(Field->getLocation(), diag::note_declared_at);
14186 Invalid = true;
14187 continue;
14188 }
14189
14190 // Check for members of const-qualified, non-class type.
14191 QualType BaseType = Context.getBaseElementType(Field->getType());
14192 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
14193 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14194 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
14195 Diag(Field->getLocation(), diag::note_declared_at);
14196 Invalid = true;
14197 continue;
14198 }
14199
14200 // Suppress assigning zero-width bitfields.
14201 if (Field->isZeroLengthBitField(Context))
14202 continue;
14203
14204 QualType FieldType = Field->getType().getNonReferenceType();
14205 if (FieldType->isIncompleteArrayType()) {
14206 assert(ClassDecl->hasFlexibleArrayMember() &&
14207 "Incomplete array type is not valid");
14208 continue;
14209 }
14210
14211 // Build references to the field in the object we're copying from and to.
14212 CXXScopeSpec SS; // Intentionally empty
14213 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
14214 LookupMemberName);
14215 MemberLookup.addDecl(Field);
14216 MemberLookup.resolveKind();
14217
14218 MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup);
14219
14220 MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup);
14221
14222 // Build the copy of this field.
14223 StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType,
14224 To, From,
14225 /*CopyingBaseSubobject=*/false,
14226 /*Copying=*/true);
14227 if (Copy.isInvalid()) {
14228 CopyAssignOperator->setInvalidDecl();
14229 return;
14230 }
14231
14232 // Success! Record the copy.
14233 Statements.push_back(Copy.getAs<Stmt>());
14234 }
14235
14236 if (!Invalid) {
14237 // Add a "return *this;"
14238 ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
14239
14240 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
14241 if (Return.isInvalid())
14242 Invalid = true;
14243 else
14244 Statements.push_back(Return.getAs<Stmt>());
14245 }
14246
14247 if (Invalid) {
14248 CopyAssignOperator->setInvalidDecl();
14249 return;
14250 }
14251
14252 StmtResult Body;
14253 {
14254 CompoundScopeRAII CompoundScope(*this);
14255 Body = ActOnCompoundStmt(Loc, Loc, Statements,
14256 /*isStmtExpr=*/false);
14257 assert(!Body.isInvalid() && "Compound statement creation cannot fail");
14258 }
14259 CopyAssignOperator->setBody(Body.getAs<Stmt>());
14260 CopyAssignOperator->markUsed(Context);
14261
14262 if (ASTMutationListener *L = getASTMutationListener()) {
14263 L->CompletedImplicitDefinition(CopyAssignOperator);
14264 }
14265 }
14266
DeclareImplicitMoveAssignment(CXXRecordDecl * ClassDecl)14267 CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
14268 assert(ClassDecl->needsImplicitMoveAssignment());
14269
14270 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment);
14271 if (DSM.isAlreadyBeingDeclared())
14272 return nullptr;
14273
14274 // Note: The following rules are largely analoguous to the move
14275 // constructor rules.
14276
14277 QualType ArgType = Context.getTypeDeclType(ClassDecl);
14278 LangAS AS = getDefaultCXXMethodAddrSpace();
14279 if (AS != LangAS::Default)
14280 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
14281 QualType RetType = Context.getLValueReferenceType(ArgType);
14282 ArgType = Context.getRValueReferenceType(ArgType);
14283
14284 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14285 CXXMoveAssignment,
14286 false);
14287
14288 // An implicitly-declared move assignment operator is an inline public
14289 // member of its class.
14290 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
14291 SourceLocation ClassLoc = ClassDecl->getLocation();
14292 DeclarationNameInfo NameInfo(Name, ClassLoc);
14293 CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create(
14294 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
14295 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
14296 /*isInline=*/true,
14297 Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified,
14298 SourceLocation());
14299 MoveAssignment->setAccess(AS_public);
14300 MoveAssignment->setDefaulted();
14301 MoveAssignment->setImplicit();
14302
14303 if (getLangOpts().CUDA) {
14304 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment,
14305 MoveAssignment,
14306 /* ConstRHS */ false,
14307 /* Diagnose */ false);
14308 }
14309
14310 // Build an exception specification pointing back at this member.
14311 FunctionProtoType::ExtProtoInfo EPI =
14312 getImplicitMethodEPI(*this, MoveAssignment);
14313 MoveAssignment->setType(Context.getFunctionType(RetType, ArgType, EPI));
14314
14315 // Add the parameter to the operator.
14316 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
14317 ClassLoc, ClassLoc,
14318 /*Id=*/nullptr, ArgType,
14319 /*TInfo=*/nullptr, SC_None,
14320 nullptr);
14321 MoveAssignment->setParams(FromParam);
14322
14323 MoveAssignment->setTrivial(
14324 ClassDecl->needsOverloadResolutionForMoveAssignment()
14325 ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment)
14326 : ClassDecl->hasTrivialMoveAssignment());
14327
14328 // Note that we have added this copy-assignment operator.
14329 ++getASTContext().NumImplicitMoveAssignmentOperatorsDeclared;
14330
14331 Scope *S = getScopeForContext(ClassDecl);
14332 CheckImplicitSpecialMemberDeclaration(S, MoveAssignment);
14333
14334 if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
14335 ClassDecl->setImplicitMoveAssignmentIsDeleted();
14336 SetDeclDeleted(MoveAssignment, ClassLoc);
14337 }
14338
14339 if (S)
14340 PushOnScopeChains(MoveAssignment, S, false);
14341 ClassDecl->addDecl(MoveAssignment);
14342
14343 return MoveAssignment;
14344 }
14345
14346 /// Check if we're implicitly defining a move assignment operator for a class
14347 /// with virtual bases. Such a move assignment might move-assign the virtual
14348 /// base multiple times.
checkMoveAssignmentForRepeatedMove(Sema & S,CXXRecordDecl * Class,SourceLocation CurrentLocation)14349 static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class,
14350 SourceLocation CurrentLocation) {
14351 assert(!Class->isDependentContext() && "should not define dependent move");
14352
14353 // Only a virtual base could get implicitly move-assigned multiple times.
14354 // Only a non-trivial move assignment can observe this. We only want to
14355 // diagnose if we implicitly define an assignment operator that assigns
14356 // two base classes, both of which move-assign the same virtual base.
14357 if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() ||
14358 Class->getNumBases() < 2)
14359 return;
14360
14361 llvm::SmallVector<CXXBaseSpecifier *, 16> Worklist;
14362 typedef llvm::DenseMap<CXXRecordDecl*, CXXBaseSpecifier*> VBaseMap;
14363 VBaseMap VBases;
14364
14365 for (auto &BI : Class->bases()) {
14366 Worklist.push_back(&BI);
14367 while (!Worklist.empty()) {
14368 CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val();
14369 CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl();
14370
14371 // If the base has no non-trivial move assignment operators,
14372 // we don't care about moves from it.
14373 if (!Base->hasNonTrivialMoveAssignment())
14374 continue;
14375
14376 // If there's nothing virtual here, skip it.
14377 if (!BaseSpec->isVirtual() && !Base->getNumVBases())
14378 continue;
14379
14380 // If we're not actually going to call a move assignment for this base,
14381 // or the selected move assignment is trivial, skip it.
14382 Sema::SpecialMemberOverloadResult SMOR =
14383 S.LookupSpecialMember(Base, Sema::CXXMoveAssignment,
14384 /*ConstArg*/false, /*VolatileArg*/false,
14385 /*RValueThis*/true, /*ConstThis*/false,
14386 /*VolatileThis*/false);
14387 if (!SMOR.getMethod() || SMOR.getMethod()->isTrivial() ||
14388 !SMOR.getMethod()->isMoveAssignmentOperator())
14389 continue;
14390
14391 if (BaseSpec->isVirtual()) {
14392 // We're going to move-assign this virtual base, and its move
14393 // assignment operator is not trivial. If this can happen for
14394 // multiple distinct direct bases of Class, diagnose it. (If it
14395 // only happens in one base, we'll diagnose it when synthesizing
14396 // that base class's move assignment operator.)
14397 CXXBaseSpecifier *&Existing =
14398 VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI))
14399 .first->second;
14400 if (Existing && Existing != &BI) {
14401 S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times)
14402 << Class << Base;
14403 S.Diag(Existing->getBeginLoc(), diag::note_vbase_moved_here)
14404 << (Base->getCanonicalDecl() ==
14405 Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl())
14406 << Base << Existing->getType() << Existing->getSourceRange();
14407 S.Diag(BI.getBeginLoc(), diag::note_vbase_moved_here)
14408 << (Base->getCanonicalDecl() ==
14409 BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl())
14410 << Base << BI.getType() << BaseSpec->getSourceRange();
14411
14412 // Only diagnose each vbase once.
14413 Existing = nullptr;
14414 }
14415 } else {
14416 // Only walk over bases that have defaulted move assignment operators.
14417 // We assume that any user-provided move assignment operator handles
14418 // the multiple-moves-of-vbase case itself somehow.
14419 if (!SMOR.getMethod()->isDefaulted())
14420 continue;
14421
14422 // We're going to move the base classes of Base. Add them to the list.
14423 for (auto &BI : Base->bases())
14424 Worklist.push_back(&BI);
14425 }
14426 }
14427 }
14428 }
14429
DefineImplicitMoveAssignment(SourceLocation CurrentLocation,CXXMethodDecl * MoveAssignOperator)14430 void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
14431 CXXMethodDecl *MoveAssignOperator) {
14432 assert((MoveAssignOperator->isDefaulted() &&
14433 MoveAssignOperator->isOverloadedOperator() &&
14434 MoveAssignOperator->getOverloadedOperator() == OO_Equal &&
14435 !MoveAssignOperator->doesThisDeclarationHaveABody() &&
14436 !MoveAssignOperator->isDeleted()) &&
14437 "DefineImplicitMoveAssignment called for wrong function");
14438 if (MoveAssignOperator->willHaveBody() || MoveAssignOperator->isInvalidDecl())
14439 return;
14440
14441 CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
14442 if (ClassDecl->isInvalidDecl()) {
14443 MoveAssignOperator->setInvalidDecl();
14444 return;
14445 }
14446
14447 // C++0x [class.copy]p28:
14448 // The implicitly-defined or move assignment operator for a non-union class
14449 // X performs memberwise move assignment of its subobjects. The direct base
14450 // classes of X are assigned first, in the order of their declaration in the
14451 // base-specifier-list, and then the immediate non-static data members of X
14452 // are assigned, in the order in which they were declared in the class
14453 // definition.
14454
14455 // Issue a warning if our implicit move assignment operator will move
14456 // from a virtual base more than once.
14457 checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation);
14458
14459 SynthesizedFunctionScope Scope(*this, MoveAssignOperator);
14460
14461 // The exception specification is needed because we are defining the
14462 // function.
14463 ResolveExceptionSpec(CurrentLocation,
14464 MoveAssignOperator->getType()->castAs<FunctionProtoType>());
14465
14466 // Add a context note for diagnostics produced after this point.
14467 Scope.addContextNote(CurrentLocation);
14468
14469 // The statements that form the synthesized function body.
14470 SmallVector<Stmt*, 8> Statements;
14471
14472 // The parameter for the "other" object, which we are move from.
14473 ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
14474 QualType OtherRefType =
14475 Other->getType()->castAs<RValueReferenceType>()->getPointeeType();
14476
14477 // Our location for everything implicitly-generated.
14478 SourceLocation Loc = MoveAssignOperator->getEndLoc().isValid()
14479 ? MoveAssignOperator->getEndLoc()
14480 : MoveAssignOperator->getLocation();
14481
14482 // Builds a reference to the "other" object.
14483 RefBuilder OtherRef(Other, OtherRefType);
14484 // Cast to rvalue.
14485 MoveCastBuilder MoveOther(OtherRef);
14486
14487 // Builds the "this" pointer.
14488 ThisBuilder This;
14489
14490 // Assign base classes.
14491 bool Invalid = false;
14492 for (auto &Base : ClassDecl->bases()) {
14493 // C++11 [class.copy]p28:
14494 // It is unspecified whether subobjects representing virtual base classes
14495 // are assigned more than once by the implicitly-defined copy assignment
14496 // operator.
14497 // FIXME: Do not assign to a vbase that will be assigned by some other base
14498 // class. For a move-assignment, this can result in the vbase being moved
14499 // multiple times.
14500
14501 // Form the assignment:
14502 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
14503 QualType BaseType = Base.getType().getUnqualifiedType();
14504 if (!BaseType->isRecordType()) {
14505 Invalid = true;
14506 continue;
14507 }
14508
14509 CXXCastPath BasePath;
14510 BasePath.push_back(&Base);
14511
14512 // Construct the "from" expression, which is an implicit cast to the
14513 // appropriately-qualified base type.
14514 CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath);
14515
14516 // Dereference "this".
14517 DerefBuilder DerefThis(This);
14518
14519 // Implicitly cast "this" to the appropriately-qualified base type.
14520 CastBuilder To(DerefThis,
14521 Context.getQualifiedType(
14522 BaseType, MoveAssignOperator->getMethodQualifiers()),
14523 VK_LValue, BasePath);
14524
14525 // Build the move.
14526 StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType,
14527 To, From,
14528 /*CopyingBaseSubobject=*/true,
14529 /*Copying=*/false);
14530 if (Move.isInvalid()) {
14531 MoveAssignOperator->setInvalidDecl();
14532 return;
14533 }
14534
14535 // Success! Record the move.
14536 Statements.push_back(Move.getAs<Expr>());
14537 }
14538
14539 // Assign non-static members.
14540 for (auto *Field : ClassDecl->fields()) {
14541 // FIXME: We should form some kind of AST representation for the implied
14542 // memcpy in a union copy operation.
14543 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
14544 continue;
14545
14546 if (Field->isInvalidDecl()) {
14547 Invalid = true;
14548 continue;
14549 }
14550
14551 // Check for members of reference type; we can't move those.
14552 if (Field->getType()->isReferenceType()) {
14553 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14554 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
14555 Diag(Field->getLocation(), diag::note_declared_at);
14556 Invalid = true;
14557 continue;
14558 }
14559
14560 // Check for members of const-qualified, non-class type.
14561 QualType BaseType = Context.getBaseElementType(Field->getType());
14562 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
14563 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14564 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
14565 Diag(Field->getLocation(), diag::note_declared_at);
14566 Invalid = true;
14567 continue;
14568 }
14569
14570 // Suppress assigning zero-width bitfields.
14571 if (Field->isZeroLengthBitField(Context))
14572 continue;
14573
14574 QualType FieldType = Field->getType().getNonReferenceType();
14575 if (FieldType->isIncompleteArrayType()) {
14576 assert(ClassDecl->hasFlexibleArrayMember() &&
14577 "Incomplete array type is not valid");
14578 continue;
14579 }
14580
14581 // Build references to the field in the object we're copying from and to.
14582 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
14583 LookupMemberName);
14584 MemberLookup.addDecl(Field);
14585 MemberLookup.resolveKind();
14586 MemberBuilder From(MoveOther, OtherRefType,
14587 /*IsArrow=*/false, MemberLookup);
14588 MemberBuilder To(This, getCurrentThisType(),
14589 /*IsArrow=*/true, MemberLookup);
14590
14591 assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue
14592 "Member reference with rvalue base must be rvalue except for reference "
14593 "members, which aren't allowed for move assignment.");
14594
14595 // Build the move of this field.
14596 StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType,
14597 To, From,
14598 /*CopyingBaseSubobject=*/false,
14599 /*Copying=*/false);
14600 if (Move.isInvalid()) {
14601 MoveAssignOperator->setInvalidDecl();
14602 return;
14603 }
14604
14605 // Success! Record the copy.
14606 Statements.push_back(Move.getAs<Stmt>());
14607 }
14608
14609 if (!Invalid) {
14610 // Add a "return *this;"
14611 ExprResult ThisObj =
14612 CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
14613
14614 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
14615 if (Return.isInvalid())
14616 Invalid = true;
14617 else
14618 Statements.push_back(Return.getAs<Stmt>());
14619 }
14620
14621 if (Invalid) {
14622 MoveAssignOperator->setInvalidDecl();
14623 return;
14624 }
14625
14626 StmtResult Body;
14627 {
14628 CompoundScopeRAII CompoundScope(*this);
14629 Body = ActOnCompoundStmt(Loc, Loc, Statements,
14630 /*isStmtExpr=*/false);
14631 assert(!Body.isInvalid() && "Compound statement creation cannot fail");
14632 }
14633 MoveAssignOperator->setBody(Body.getAs<Stmt>());
14634 MoveAssignOperator->markUsed(Context);
14635
14636 if (ASTMutationListener *L = getASTMutationListener()) {
14637 L->CompletedImplicitDefinition(MoveAssignOperator);
14638 }
14639 }
14640
DeclareImplicitCopyConstructor(CXXRecordDecl * ClassDecl)14641 CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
14642 CXXRecordDecl *ClassDecl) {
14643 // C++ [class.copy]p4:
14644 // If the class definition does not explicitly declare a copy
14645 // constructor, one is declared implicitly.
14646 assert(ClassDecl->needsImplicitCopyConstructor());
14647
14648 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor);
14649 if (DSM.isAlreadyBeingDeclared())
14650 return nullptr;
14651
14652 QualType ClassType = Context.getTypeDeclType(ClassDecl);
14653 QualType ArgType = ClassType;
14654 bool Const = ClassDecl->implicitCopyConstructorHasConstParam();
14655 if (Const)
14656 ArgType = ArgType.withConst();
14657
14658 LangAS AS = getDefaultCXXMethodAddrSpace();
14659 if (AS != LangAS::Default)
14660 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
14661
14662 ArgType = Context.getLValueReferenceType(ArgType);
14663
14664 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14665 CXXCopyConstructor,
14666 Const);
14667
14668 DeclarationName Name
14669 = Context.DeclarationNames.getCXXConstructorName(
14670 Context.getCanonicalType(ClassType));
14671 SourceLocation ClassLoc = ClassDecl->getLocation();
14672 DeclarationNameInfo NameInfo(Name, ClassLoc);
14673
14674 // An implicitly-declared copy constructor is an inline public
14675 // member of its class.
14676 CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
14677 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
14678 ExplicitSpecifier(),
14679 /*isInline=*/true,
14680 /*isImplicitlyDeclared=*/true,
14681 Constexpr ? ConstexprSpecKind::Constexpr
14682 : ConstexprSpecKind::Unspecified);
14683 CopyConstructor->setAccess(AS_public);
14684 CopyConstructor->setDefaulted();
14685
14686 if (getLangOpts().CUDA) {
14687 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor,
14688 CopyConstructor,
14689 /* ConstRHS */ Const,
14690 /* Diagnose */ false);
14691 }
14692
14693 setupImplicitSpecialMemberType(CopyConstructor, Context.VoidTy, ArgType);
14694
14695 // Add the parameter to the constructor.
14696 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
14697 ClassLoc, ClassLoc,
14698 /*IdentifierInfo=*/nullptr,
14699 ArgType, /*TInfo=*/nullptr,
14700 SC_None, nullptr);
14701 CopyConstructor->setParams(FromParam);
14702
14703 CopyConstructor->setTrivial(
14704 ClassDecl->needsOverloadResolutionForCopyConstructor()
14705 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor)
14706 : ClassDecl->hasTrivialCopyConstructor());
14707
14708 CopyConstructor->setTrivialForCall(
14709 ClassDecl->hasAttr<TrivialABIAttr>() ||
14710 (ClassDecl->needsOverloadResolutionForCopyConstructor()
14711 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor,
14712 TAH_ConsiderTrivialABI)
14713 : ClassDecl->hasTrivialCopyConstructorForCall()));
14714
14715 // Note that we have declared this constructor.
14716 ++getASTContext().NumImplicitCopyConstructorsDeclared;
14717
14718 Scope *S = getScopeForContext(ClassDecl);
14719 CheckImplicitSpecialMemberDeclaration(S, CopyConstructor);
14720
14721 if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) {
14722 ClassDecl->setImplicitCopyConstructorIsDeleted();
14723 SetDeclDeleted(CopyConstructor, ClassLoc);
14724 }
14725
14726 if (S)
14727 PushOnScopeChains(CopyConstructor, S, false);
14728 ClassDecl->addDecl(CopyConstructor);
14729
14730 return CopyConstructor;
14731 }
14732
DefineImplicitCopyConstructor(SourceLocation CurrentLocation,CXXConstructorDecl * CopyConstructor)14733 void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
14734 CXXConstructorDecl *CopyConstructor) {
14735 assert((CopyConstructor->isDefaulted() &&
14736 CopyConstructor->isCopyConstructor() &&
14737 !CopyConstructor->doesThisDeclarationHaveABody() &&
14738 !CopyConstructor->isDeleted()) &&
14739 "DefineImplicitCopyConstructor - call it for implicit copy ctor");
14740 if (CopyConstructor->willHaveBody() || CopyConstructor->isInvalidDecl())
14741 return;
14742
14743 CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
14744 assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
14745
14746 SynthesizedFunctionScope Scope(*this, CopyConstructor);
14747
14748 // The exception specification is needed because we are defining the
14749 // function.
14750 ResolveExceptionSpec(CurrentLocation,
14751 CopyConstructor->getType()->castAs<FunctionProtoType>());
14752 MarkVTableUsed(CurrentLocation, ClassDecl);
14753
14754 // Add a context note for diagnostics produced after this point.
14755 Scope.addContextNote(CurrentLocation);
14756
14757 // C++11 [class.copy]p7:
14758 // The [definition of an implicitly declared copy constructor] is
14759 // deprecated if the class has a user-declared copy assignment operator
14760 // or a user-declared destructor.
14761 if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit())
14762 diagnoseDeprecatedCopyOperation(*this, CopyConstructor);
14763
14764 if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false)) {
14765 CopyConstructor->setInvalidDecl();
14766 } else {
14767 SourceLocation Loc = CopyConstructor->getEndLoc().isValid()
14768 ? CopyConstructor->getEndLoc()
14769 : CopyConstructor->getLocation();
14770 Sema::CompoundScopeRAII CompoundScope(*this);
14771 CopyConstructor->setBody(
14772 ActOnCompoundStmt(Loc, Loc, None, /*isStmtExpr=*/false).getAs<Stmt>());
14773 CopyConstructor->markUsed(Context);
14774 }
14775
14776 if (ASTMutationListener *L = getASTMutationListener()) {
14777 L->CompletedImplicitDefinition(CopyConstructor);
14778 }
14779 }
14780
DeclareImplicitMoveConstructor(CXXRecordDecl * ClassDecl)14781 CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
14782 CXXRecordDecl *ClassDecl) {
14783 assert(ClassDecl->needsImplicitMoveConstructor());
14784
14785 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor);
14786 if (DSM.isAlreadyBeingDeclared())
14787 return nullptr;
14788
14789 QualType ClassType = Context.getTypeDeclType(ClassDecl);
14790
14791 QualType ArgType = ClassType;
14792 LangAS AS = getDefaultCXXMethodAddrSpace();
14793 if (AS != LangAS::Default)
14794 ArgType = Context.getAddrSpaceQualType(ClassType, AS);
14795 ArgType = Context.getRValueReferenceType(ArgType);
14796
14797 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14798 CXXMoveConstructor,
14799 false);
14800
14801 DeclarationName Name
14802 = Context.DeclarationNames.getCXXConstructorName(
14803 Context.getCanonicalType(ClassType));
14804 SourceLocation ClassLoc = ClassDecl->getLocation();
14805 DeclarationNameInfo NameInfo(Name, ClassLoc);
14806
14807 // C++11 [class.copy]p11:
14808 // An implicitly-declared copy/move constructor is an inline public
14809 // member of its class.
14810 CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
14811 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
14812 ExplicitSpecifier(),
14813 /*isInline=*/true,
14814 /*isImplicitlyDeclared=*/true,
14815 Constexpr ? ConstexprSpecKind::Constexpr
14816 : ConstexprSpecKind::Unspecified);
14817 MoveConstructor->setAccess(AS_public);
14818 MoveConstructor->setDefaulted();
14819
14820 if (getLangOpts().CUDA) {
14821 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor,
14822 MoveConstructor,
14823 /* ConstRHS */ false,
14824 /* Diagnose */ false);
14825 }
14826
14827 setupImplicitSpecialMemberType(MoveConstructor, Context.VoidTy, ArgType);
14828
14829 // Add the parameter to the constructor.
14830 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
14831 ClassLoc, ClassLoc,
14832 /*IdentifierInfo=*/nullptr,
14833 ArgType, /*TInfo=*/nullptr,
14834 SC_None, nullptr);
14835 MoveConstructor->setParams(FromParam);
14836
14837 MoveConstructor->setTrivial(
14838 ClassDecl->needsOverloadResolutionForMoveConstructor()
14839 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor)
14840 : ClassDecl->hasTrivialMoveConstructor());
14841
14842 MoveConstructor->setTrivialForCall(
14843 ClassDecl->hasAttr<TrivialABIAttr>() ||
14844 (ClassDecl->needsOverloadResolutionForMoveConstructor()
14845 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor,
14846 TAH_ConsiderTrivialABI)
14847 : ClassDecl->hasTrivialMoveConstructorForCall()));
14848
14849 // Note that we have declared this constructor.
14850 ++getASTContext().NumImplicitMoveConstructorsDeclared;
14851
14852 Scope *S = getScopeForContext(ClassDecl);
14853 CheckImplicitSpecialMemberDeclaration(S, MoveConstructor);
14854
14855 if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
14856 ClassDecl->setImplicitMoveConstructorIsDeleted();
14857 SetDeclDeleted(MoveConstructor, ClassLoc);
14858 }
14859
14860 if (S)
14861 PushOnScopeChains(MoveConstructor, S, false);
14862 ClassDecl->addDecl(MoveConstructor);
14863
14864 return MoveConstructor;
14865 }
14866
DefineImplicitMoveConstructor(SourceLocation CurrentLocation,CXXConstructorDecl * MoveConstructor)14867 void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
14868 CXXConstructorDecl *MoveConstructor) {
14869 assert((MoveConstructor->isDefaulted() &&
14870 MoveConstructor->isMoveConstructor() &&
14871 !MoveConstructor->doesThisDeclarationHaveABody() &&
14872 !MoveConstructor->isDeleted()) &&
14873 "DefineImplicitMoveConstructor - call it for implicit move ctor");
14874 if (MoveConstructor->willHaveBody() || MoveConstructor->isInvalidDecl())
14875 return;
14876
14877 CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
14878 assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor");
14879
14880 SynthesizedFunctionScope Scope(*this, MoveConstructor);
14881
14882 // The exception specification is needed because we are defining the
14883 // function.
14884 ResolveExceptionSpec(CurrentLocation,
14885 MoveConstructor->getType()->castAs<FunctionProtoType>());
14886 MarkVTableUsed(CurrentLocation, ClassDecl);
14887
14888 // Add a context note for diagnostics produced after this point.
14889 Scope.addContextNote(CurrentLocation);
14890
14891 if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false)) {
14892 MoveConstructor->setInvalidDecl();
14893 } else {
14894 SourceLocation Loc = MoveConstructor->getEndLoc().isValid()
14895 ? MoveConstructor->getEndLoc()
14896 : MoveConstructor->getLocation();
14897 Sema::CompoundScopeRAII CompoundScope(*this);
14898 MoveConstructor->setBody(ActOnCompoundStmt(
14899 Loc, Loc, None, /*isStmtExpr=*/ false).getAs<Stmt>());
14900 MoveConstructor->markUsed(Context);
14901 }
14902
14903 if (ASTMutationListener *L = getASTMutationListener()) {
14904 L->CompletedImplicitDefinition(MoveConstructor);
14905 }
14906 }
14907
isImplicitlyDeleted(FunctionDecl * FD)14908 bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
14909 return FD->isDeleted() && FD->isDefaulted() && isa<CXXMethodDecl>(FD);
14910 }
14911
DefineImplicitLambdaToFunctionPointerConversion(SourceLocation CurrentLocation,CXXConversionDecl * Conv)14912 void Sema::DefineImplicitLambdaToFunctionPointerConversion(
14913 SourceLocation CurrentLocation,
14914 CXXConversionDecl *Conv) {
14915 SynthesizedFunctionScope Scope(*this, Conv);
14916 assert(!Conv->getReturnType()->isUndeducedType());
14917
14918 QualType ConvRT = Conv->getType()->castAs<FunctionType>()->getReturnType();
14919 CallingConv CC =
14920 ConvRT->getPointeeType()->castAs<FunctionType>()->getCallConv();
14921
14922 CXXRecordDecl *Lambda = Conv->getParent();
14923 FunctionDecl *CallOp = Lambda->getLambdaCallOperator();
14924 FunctionDecl *Invoker = Lambda->getLambdaStaticInvoker(CC);
14925
14926 if (auto *TemplateArgs = Conv->getTemplateSpecializationArgs()) {
14927 CallOp = InstantiateFunctionDeclaration(
14928 CallOp->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
14929 if (!CallOp)
14930 return;
14931
14932 Invoker = InstantiateFunctionDeclaration(
14933 Invoker->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
14934 if (!Invoker)
14935 return;
14936 }
14937
14938 if (CallOp->isInvalidDecl())
14939 return;
14940
14941 // Mark the call operator referenced (and add to pending instantiations
14942 // if necessary).
14943 // For both the conversion and static-invoker template specializations
14944 // we construct their body's in this function, so no need to add them
14945 // to the PendingInstantiations.
14946 MarkFunctionReferenced(CurrentLocation, CallOp);
14947
14948 // Fill in the __invoke function with a dummy implementation. IR generation
14949 // will fill in the actual details. Update its type in case it contained
14950 // an 'auto'.
14951 Invoker->markUsed(Context);
14952 Invoker->setReferenced();
14953 Invoker->setType(Conv->getReturnType()->getPointeeType());
14954 Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation()));
14955
14956 // Construct the body of the conversion function { return __invoke; }.
14957 Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(),
14958 VK_LValue, Conv->getLocation());
14959 assert(FunctionRef && "Can't refer to __invoke function?");
14960 Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get();
14961 Conv->setBody(CompoundStmt::Create(Context, Return, Conv->getLocation(),
14962 Conv->getLocation()));
14963 Conv->markUsed(Context);
14964 Conv->setReferenced();
14965
14966 if (ASTMutationListener *L = getASTMutationListener()) {
14967 L->CompletedImplicitDefinition(Conv);
14968 L->CompletedImplicitDefinition(Invoker);
14969 }
14970 }
14971
14972
14973
DefineImplicitLambdaToBlockPointerConversion(SourceLocation CurrentLocation,CXXConversionDecl * Conv)14974 void Sema::DefineImplicitLambdaToBlockPointerConversion(
14975 SourceLocation CurrentLocation,
14976 CXXConversionDecl *Conv)
14977 {
14978 assert(!Conv->getParent()->isGenericLambda());
14979
14980 SynthesizedFunctionScope Scope(*this, Conv);
14981
14982 // Copy-initialize the lambda object as needed to capture it.
14983 Expr *This = ActOnCXXThis(CurrentLocation).get();
14984 Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get();
14985
14986 ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
14987 Conv->getLocation(),
14988 Conv, DerefThis);
14989
14990 // If we're not under ARC, make sure we still get the _Block_copy/autorelease
14991 // behavior. Note that only the general conversion function does this
14992 // (since it's unusable otherwise); in the case where we inline the
14993 // block literal, it has block literal lifetime semantics.
14994 if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
14995 BuildBlock = ImplicitCastExpr::Create(
14996 Context, BuildBlock.get()->getType(), CK_CopyAndAutoreleaseBlockObject,
14997 BuildBlock.get(), nullptr, VK_RValue, FPOptionsOverride());
14998
14999 if (BuildBlock.isInvalid()) {
15000 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
15001 Conv->setInvalidDecl();
15002 return;
15003 }
15004
15005 // Create the return statement that returns the block from the conversion
15006 // function.
15007 StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get());
15008 if (Return.isInvalid()) {
15009 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
15010 Conv->setInvalidDecl();
15011 return;
15012 }
15013
15014 // Set the body of the conversion function.
15015 Stmt *ReturnS = Return.get();
15016 Conv->setBody(CompoundStmt::Create(Context, ReturnS, Conv->getLocation(),
15017 Conv->getLocation()));
15018 Conv->markUsed(Context);
15019
15020 // We're done; notify the mutation listener, if any.
15021 if (ASTMutationListener *L = getASTMutationListener()) {
15022 L->CompletedImplicitDefinition(Conv);
15023 }
15024 }
15025
15026 /// Determine whether the given list arguments contains exactly one
15027 /// "real" (non-default) argument.
hasOneRealArgument(MultiExprArg Args)15028 static bool hasOneRealArgument(MultiExprArg Args) {
15029 switch (Args.size()) {
15030 case 0:
15031 return false;
15032
15033 default:
15034 if (!Args[1]->isDefaultArgument())
15035 return false;
15036
15037 LLVM_FALLTHROUGH;
15038 case 1:
15039 return !Args[0]->isDefaultArgument();
15040 }
15041
15042 return false;
15043 }
15044
15045 ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc,QualType DeclInitType,NamedDecl * FoundDecl,CXXConstructorDecl * Constructor,MultiExprArg ExprArgs,bool HadMultipleCandidates,bool IsListInitialization,bool IsStdInitListInitialization,bool RequiresZeroInit,unsigned ConstructKind,SourceRange ParenRange)15046 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
15047 NamedDecl *FoundDecl,
15048 CXXConstructorDecl *Constructor,
15049 MultiExprArg ExprArgs,
15050 bool HadMultipleCandidates,
15051 bool IsListInitialization,
15052 bool IsStdInitListInitialization,
15053 bool RequiresZeroInit,
15054 unsigned ConstructKind,
15055 SourceRange ParenRange) {
15056 bool Elidable = false;
15057
15058 // C++0x [class.copy]p34:
15059 // When certain criteria are met, an implementation is allowed to
15060 // omit the copy/move construction of a class object, even if the
15061 // copy/move constructor and/or destructor for the object have
15062 // side effects. [...]
15063 // - when a temporary class object that has not been bound to a
15064 // reference (12.2) would be copied/moved to a class object
15065 // with the same cv-unqualified type, the copy/move operation
15066 // can be omitted by constructing the temporary object
15067 // directly into the target of the omitted copy/move
15068 if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor &&
15069 Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
15070 Expr *SubExpr = ExprArgs[0];
15071 Elidable = SubExpr->isTemporaryObject(
15072 Context, cast<CXXRecordDecl>(FoundDecl->getDeclContext()));
15073 }
15074
15075 return BuildCXXConstructExpr(ConstructLoc, DeclInitType,
15076 FoundDecl, Constructor,
15077 Elidable, ExprArgs, HadMultipleCandidates,
15078 IsListInitialization,
15079 IsStdInitListInitialization, RequiresZeroInit,
15080 ConstructKind, ParenRange);
15081 }
15082
15083 ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc,QualType DeclInitType,NamedDecl * FoundDecl,CXXConstructorDecl * Constructor,bool Elidable,MultiExprArg ExprArgs,bool HadMultipleCandidates,bool IsListInitialization,bool IsStdInitListInitialization,bool RequiresZeroInit,unsigned ConstructKind,SourceRange ParenRange)15084 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
15085 NamedDecl *FoundDecl,
15086 CXXConstructorDecl *Constructor,
15087 bool Elidable,
15088 MultiExprArg ExprArgs,
15089 bool HadMultipleCandidates,
15090 bool IsListInitialization,
15091 bool IsStdInitListInitialization,
15092 bool RequiresZeroInit,
15093 unsigned ConstructKind,
15094 SourceRange ParenRange) {
15095 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl)) {
15096 Constructor = findInheritingConstructor(ConstructLoc, Constructor, Shadow);
15097 if (DiagnoseUseOfDecl(Constructor, ConstructLoc))
15098 return ExprError();
15099 }
15100
15101 return BuildCXXConstructExpr(
15102 ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs,
15103 HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization,
15104 RequiresZeroInit, ConstructKind, ParenRange);
15105 }
15106
15107 /// BuildCXXConstructExpr - Creates a complete call to a constructor,
15108 /// including handling of its default argument expressions.
15109 ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc,QualType DeclInitType,CXXConstructorDecl * Constructor,bool Elidable,MultiExprArg ExprArgs,bool HadMultipleCandidates,bool IsListInitialization,bool IsStdInitListInitialization,bool RequiresZeroInit,unsigned ConstructKind,SourceRange ParenRange)15110 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
15111 CXXConstructorDecl *Constructor,
15112 bool Elidable,
15113 MultiExprArg ExprArgs,
15114 bool HadMultipleCandidates,
15115 bool IsListInitialization,
15116 bool IsStdInitListInitialization,
15117 bool RequiresZeroInit,
15118 unsigned ConstructKind,
15119 SourceRange ParenRange) {
15120 assert(declaresSameEntity(
15121 Constructor->getParent(),
15122 DeclInitType->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) &&
15123 "given constructor for wrong type");
15124 MarkFunctionReferenced(ConstructLoc, Constructor);
15125 if (getLangOpts().CUDA && !CheckCUDACall(ConstructLoc, Constructor))
15126 return ExprError();
15127 if (getLangOpts().SYCLIsDevice &&
15128 !checkSYCLDeviceFunction(ConstructLoc, Constructor))
15129 return ExprError();
15130
15131 return CheckForImmediateInvocation(
15132 CXXConstructExpr::Create(
15133 Context, DeclInitType, ConstructLoc, Constructor, Elidable, ExprArgs,
15134 HadMultipleCandidates, IsListInitialization,
15135 IsStdInitListInitialization, RequiresZeroInit,
15136 static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
15137 ParenRange),
15138 Constructor);
15139 }
15140
BuildCXXDefaultInitExpr(SourceLocation Loc,FieldDecl * Field)15141 ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) {
15142 assert(Field->hasInClassInitializer());
15143
15144 // If we already have the in-class initializer nothing needs to be done.
15145 if (Field->getInClassInitializer())
15146 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
15147
15148 // If we might have already tried and failed to instantiate, don't try again.
15149 if (Field->isInvalidDecl())
15150 return ExprError();
15151
15152 // Maybe we haven't instantiated the in-class initializer. Go check the
15153 // pattern FieldDecl to see if it has one.
15154 CXXRecordDecl *ParentRD = cast<CXXRecordDecl>(Field->getParent());
15155
15156 if (isTemplateInstantiation(ParentRD->getTemplateSpecializationKind())) {
15157 CXXRecordDecl *ClassPattern = ParentRD->getTemplateInstantiationPattern();
15158 DeclContext::lookup_result Lookup =
15159 ClassPattern->lookup(Field->getDeclName());
15160
15161 FieldDecl *Pattern = nullptr;
15162 for (auto L : Lookup) {
15163 if (isa<FieldDecl>(L)) {
15164 Pattern = cast<FieldDecl>(L);
15165 break;
15166 }
15167 }
15168 assert(Pattern && "We must have set the Pattern!");
15169
15170 if (!Pattern->hasInClassInitializer() ||
15171 InstantiateInClassInitializer(Loc, Field, Pattern,
15172 getTemplateInstantiationArgs(Field))) {
15173 // Don't diagnose this again.
15174 Field->setInvalidDecl();
15175 return ExprError();
15176 }
15177 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
15178 }
15179
15180 // DR1351:
15181 // If the brace-or-equal-initializer of a non-static data member
15182 // invokes a defaulted default constructor of its class or of an
15183 // enclosing class in a potentially evaluated subexpression, the
15184 // program is ill-formed.
15185 //
15186 // This resolution is unworkable: the exception specification of the
15187 // default constructor can be needed in an unevaluated context, in
15188 // particular, in the operand of a noexcept-expression, and we can be
15189 // unable to compute an exception specification for an enclosed class.
15190 //
15191 // Any attempt to resolve the exception specification of a defaulted default
15192 // constructor before the initializer is lexically complete will ultimately
15193 // come here at which point we can diagnose it.
15194 RecordDecl *OutermostClass = ParentRD->getOuterLexicalRecordContext();
15195 Diag(Loc, diag::err_default_member_initializer_not_yet_parsed)
15196 << OutermostClass << Field;
15197 Diag(Field->getEndLoc(),
15198 diag::note_default_member_initializer_not_yet_parsed);
15199 // Recover by marking the field invalid, unless we're in a SFINAE context.
15200 if (!isSFINAEContext())
15201 Field->setInvalidDecl();
15202 return ExprError();
15203 }
15204
FinalizeVarWithDestructor(VarDecl * VD,const RecordType * Record)15205 void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
15206 if (VD->isInvalidDecl()) return;
15207 // If initializing the variable failed, don't also diagnose problems with
15208 // the desctructor, they're likely related.
15209 if (VD->getInit() && VD->getInit()->containsErrors())
15210 return;
15211
15212 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
15213 if (ClassDecl->isInvalidDecl()) return;
15214 if (ClassDecl->hasIrrelevantDestructor()) return;
15215 if (ClassDecl->isDependentContext()) return;
15216
15217 if (VD->isNoDestroy(getASTContext()))
15218 return;
15219
15220 CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
15221
15222 // If this is an array, we'll require the destructor during initialization, so
15223 // we can skip over this. We still want to emit exit-time destructor warnings
15224 // though.
15225 if (!VD->getType()->isArrayType()) {
15226 MarkFunctionReferenced(VD->getLocation(), Destructor);
15227 CheckDestructorAccess(VD->getLocation(), Destructor,
15228 PDiag(diag::err_access_dtor_var)
15229 << VD->getDeclName() << VD->getType());
15230 DiagnoseUseOfDecl(Destructor, VD->getLocation());
15231 }
15232
15233 if (Destructor->isTrivial()) return;
15234
15235 // If the destructor is constexpr, check whether the variable has constant
15236 // destruction now.
15237 if (Destructor->isConstexpr()) {
15238 bool HasConstantInit = false;
15239 if (VD->getInit() && !VD->getInit()->isValueDependent())
15240 HasConstantInit = VD->evaluateValue();
15241 SmallVector<PartialDiagnosticAt, 8> Notes;
15242 if (!VD->evaluateDestruction(Notes) && VD->isConstexpr() &&
15243 HasConstantInit) {
15244 Diag(VD->getLocation(),
15245 diag::err_constexpr_var_requires_const_destruction) << VD;
15246 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
15247 Diag(Notes[I].first, Notes[I].second);
15248 }
15249 }
15250
15251 if (!VD->hasGlobalStorage()) return;
15252
15253 // Emit warning for non-trivial dtor in global scope (a real global,
15254 // class-static, function-static).
15255 Diag(VD->getLocation(), diag::warn_exit_time_destructor);
15256
15257 // TODO: this should be re-enabled for static locals by !CXAAtExit
15258 if (!VD->isStaticLocal())
15259 Diag(VD->getLocation(), diag::warn_global_destructor);
15260 }
15261
15262 /// Given a constructor and the set of arguments provided for the
15263 /// constructor, convert the arguments and add any required default arguments
15264 /// to form a proper call to this constructor.
15265 ///
15266 /// \returns true if an error occurred, false otherwise.
CompleteConstructorCall(CXXConstructorDecl * Constructor,QualType DeclInitType,MultiExprArg ArgsPtr,SourceLocation Loc,SmallVectorImpl<Expr * > & ConvertedArgs,bool AllowExplicit,bool IsListInitialization)15267 bool Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
15268 QualType DeclInitType, MultiExprArg ArgsPtr,
15269 SourceLocation Loc,
15270 SmallVectorImpl<Expr *> &ConvertedArgs,
15271 bool AllowExplicit,
15272 bool IsListInitialization) {
15273 // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
15274 unsigned NumArgs = ArgsPtr.size();
15275 Expr **Args = ArgsPtr.data();
15276
15277 const auto *Proto = Constructor->getType()->castAs<FunctionProtoType>();
15278 unsigned NumParams = Proto->getNumParams();
15279
15280 // If too few arguments are available, we'll fill in the rest with defaults.
15281 if (NumArgs < NumParams)
15282 ConvertedArgs.reserve(NumParams);
15283 else
15284 ConvertedArgs.reserve(NumArgs);
15285
15286 VariadicCallType CallType =
15287 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
15288 SmallVector<Expr *, 8> AllArgs;
15289 bool Invalid = GatherArgumentsForCall(Loc, Constructor,
15290 Proto, 0,
15291 llvm::makeArrayRef(Args, NumArgs),
15292 AllArgs,
15293 CallType, AllowExplicit,
15294 IsListInitialization);
15295 ConvertedArgs.append(AllArgs.begin(), AllArgs.end());
15296
15297 DiagnoseSentinelCalls(Constructor, Loc, AllArgs);
15298
15299 CheckConstructorCall(Constructor, DeclInitType,
15300 llvm::makeArrayRef(AllArgs.data(), AllArgs.size()),
15301 Proto, Loc);
15302
15303 return Invalid;
15304 }
15305
15306 static inline bool
CheckOperatorNewDeleteDeclarationScope(Sema & SemaRef,const FunctionDecl * FnDecl)15307 CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
15308 const FunctionDecl *FnDecl) {
15309 const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
15310 if (isa<NamespaceDecl>(DC)) {
15311 return SemaRef.Diag(FnDecl->getLocation(),
15312 diag::err_operator_new_delete_declared_in_namespace)
15313 << FnDecl->getDeclName();
15314 }
15315
15316 if (isa<TranslationUnitDecl>(DC) &&
15317 FnDecl->getStorageClass() == SC_Static) {
15318 return SemaRef.Diag(FnDecl->getLocation(),
15319 diag::err_operator_new_delete_declared_static)
15320 << FnDecl->getDeclName();
15321 }
15322
15323 return false;
15324 }
15325
RemoveAddressSpaceFromPtr(Sema & SemaRef,const PointerType * PtrTy)15326 static CanQualType RemoveAddressSpaceFromPtr(Sema &SemaRef,
15327 const PointerType *PtrTy) {
15328 auto &Ctx = SemaRef.Context;
15329 Qualifiers PtrQuals = PtrTy->getPointeeType().getQualifiers();
15330 PtrQuals.removeAddressSpace();
15331 return Ctx.getPointerType(Ctx.getCanonicalType(Ctx.getQualifiedType(
15332 PtrTy->getPointeeType().getUnqualifiedType(), PtrQuals)));
15333 }
15334
15335 static inline bool
CheckOperatorNewDeleteTypes(Sema & SemaRef,const FunctionDecl * FnDecl,CanQualType ExpectedResultType,CanQualType ExpectedFirstParamType,unsigned DependentParamTypeDiag,unsigned InvalidParamTypeDiag)15336 CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
15337 CanQualType ExpectedResultType,
15338 CanQualType ExpectedFirstParamType,
15339 unsigned DependentParamTypeDiag,
15340 unsigned InvalidParamTypeDiag) {
15341 QualType ResultType =
15342 FnDecl->getType()->castAs<FunctionType>()->getReturnType();
15343
15344 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
15345 // The operator is valid on any address space for OpenCL.
15346 // Drop address space from actual and expected result types.
15347 if (const auto *PtrTy = ResultType->getAs<PointerType>())
15348 ResultType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
15349
15350 if (auto ExpectedPtrTy = ExpectedResultType->getAs<PointerType>())
15351 ExpectedResultType = RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy);
15352 }
15353
15354 // Check that the result type is what we expect.
15355 if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType) {
15356 // Reject even if the type is dependent; an operator delete function is
15357 // required to have a non-dependent result type.
15358 return SemaRef.Diag(
15359 FnDecl->getLocation(),
15360 ResultType->isDependentType()
15361 ? diag::err_operator_new_delete_dependent_result_type
15362 : diag::err_operator_new_delete_invalid_result_type)
15363 << FnDecl->getDeclName() << ExpectedResultType;
15364 }
15365
15366 // A function template must have at least 2 parameters.
15367 if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
15368 return SemaRef.Diag(FnDecl->getLocation(),
15369 diag::err_operator_new_delete_template_too_few_parameters)
15370 << FnDecl->getDeclName();
15371
15372 // The function decl must have at least 1 parameter.
15373 if (FnDecl->getNumParams() == 0)
15374 return SemaRef.Diag(FnDecl->getLocation(),
15375 diag::err_operator_new_delete_too_few_parameters)
15376 << FnDecl->getDeclName();
15377
15378 QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
15379 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
15380 // The operator is valid on any address space for OpenCL.
15381 // Drop address space from actual and expected first parameter types.
15382 if (const auto *PtrTy =
15383 FnDecl->getParamDecl(0)->getType()->getAs<PointerType>())
15384 FirstParamType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
15385
15386 if (auto ExpectedPtrTy = ExpectedFirstParamType->getAs<PointerType>())
15387 ExpectedFirstParamType =
15388 RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy);
15389 }
15390
15391 // Check that the first parameter type is what we expect.
15392 if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
15393 ExpectedFirstParamType) {
15394 // The first parameter type is not allowed to be dependent. As a tentative
15395 // DR resolution, we allow a dependent parameter type if it is the right
15396 // type anyway, to allow destroying operator delete in class templates.
15397 return SemaRef.Diag(FnDecl->getLocation(), FirstParamType->isDependentType()
15398 ? DependentParamTypeDiag
15399 : InvalidParamTypeDiag)
15400 << FnDecl->getDeclName() << ExpectedFirstParamType;
15401 }
15402
15403 return false;
15404 }
15405
15406 static bool
CheckOperatorNewDeclaration(Sema & SemaRef,const FunctionDecl * FnDecl)15407 CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
15408 // C++ [basic.stc.dynamic.allocation]p1:
15409 // A program is ill-formed if an allocation function is declared in a
15410 // namespace scope other than global scope or declared static in global
15411 // scope.
15412 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
15413 return true;
15414
15415 CanQualType SizeTy =
15416 SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
15417
15418 // C++ [basic.stc.dynamic.allocation]p1:
15419 // The return type shall be void*. The first parameter shall have type
15420 // std::size_t.
15421 if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
15422 SizeTy,
15423 diag::err_operator_new_dependent_param_type,
15424 diag::err_operator_new_param_type))
15425 return true;
15426
15427 // C++ [basic.stc.dynamic.allocation]p1:
15428 // The first parameter shall not have an associated default argument.
15429 if (FnDecl->getParamDecl(0)->hasDefaultArg())
15430 return SemaRef.Diag(FnDecl->getLocation(),
15431 diag::err_operator_new_default_arg)
15432 << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
15433
15434 return false;
15435 }
15436
15437 static bool
CheckOperatorDeleteDeclaration(Sema & SemaRef,FunctionDecl * FnDecl)15438 CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) {
15439 // C++ [basic.stc.dynamic.deallocation]p1:
15440 // A program is ill-formed if deallocation functions are declared in a
15441 // namespace scope other than global scope or declared static in global
15442 // scope.
15443 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
15444 return true;
15445
15446 auto *MD = dyn_cast<CXXMethodDecl>(FnDecl);
15447
15448 // C++ P0722:
15449 // Within a class C, the first parameter of a destroying operator delete
15450 // shall be of type C *. The first parameter of any other deallocation
15451 // function shall be of type void *.
15452 CanQualType ExpectedFirstParamType =
15453 MD && MD->isDestroyingOperatorDelete()
15454 ? SemaRef.Context.getCanonicalType(SemaRef.Context.getPointerType(
15455 SemaRef.Context.getRecordType(MD->getParent())))
15456 : SemaRef.Context.VoidPtrTy;
15457
15458 // C++ [basic.stc.dynamic.deallocation]p2:
15459 // Each deallocation function shall return void
15460 if (CheckOperatorNewDeleteTypes(
15461 SemaRef, FnDecl, SemaRef.Context.VoidTy, ExpectedFirstParamType,
15462 diag::err_operator_delete_dependent_param_type,
15463 diag::err_operator_delete_param_type))
15464 return true;
15465
15466 // C++ P0722:
15467 // A destroying operator delete shall be a usual deallocation function.
15468 if (MD && !MD->getParent()->isDependentContext() &&
15469 MD->isDestroyingOperatorDelete() &&
15470 !SemaRef.isUsualDeallocationFunction(MD)) {
15471 SemaRef.Diag(MD->getLocation(),
15472 diag::err_destroying_operator_delete_not_usual);
15473 return true;
15474 }
15475
15476 return false;
15477 }
15478
15479 /// CheckOverloadedOperatorDeclaration - Check whether the declaration
15480 /// of this overloaded operator is well-formed. If so, returns false;
15481 /// otherwise, emits appropriate diagnostics and returns true.
CheckOverloadedOperatorDeclaration(FunctionDecl * FnDecl)15482 bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
15483 assert(FnDecl && FnDecl->isOverloadedOperator() &&
15484 "Expected an overloaded operator declaration");
15485
15486 OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
15487
15488 // C++ [over.oper]p5:
15489 // The allocation and deallocation functions, operator new,
15490 // operator new[], operator delete and operator delete[], are
15491 // described completely in 3.7.3. The attributes and restrictions
15492 // found in the rest of this subclause do not apply to them unless
15493 // explicitly stated in 3.7.3.
15494 if (Op == OO_Delete || Op == OO_Array_Delete)
15495 return CheckOperatorDeleteDeclaration(*this, FnDecl);
15496
15497 if (Op == OO_New || Op == OO_Array_New)
15498 return CheckOperatorNewDeclaration(*this, FnDecl);
15499
15500 // C++ [over.oper]p6:
15501 // An operator function shall either be a non-static member
15502 // function or be a non-member function and have at least one
15503 // parameter whose type is a class, a reference to a class, an
15504 // enumeration, or a reference to an enumeration.
15505 if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
15506 if (MethodDecl->isStatic())
15507 return Diag(FnDecl->getLocation(),
15508 diag::err_operator_overload_static) << FnDecl->getDeclName();
15509 } else {
15510 bool ClassOrEnumParam = false;
15511 for (auto Param : FnDecl->parameters()) {
15512 QualType ParamType = Param->getType().getNonReferenceType();
15513 if (ParamType->isDependentType() || ParamType->isRecordType() ||
15514 ParamType->isEnumeralType()) {
15515 ClassOrEnumParam = true;
15516 break;
15517 }
15518 }
15519
15520 if (!ClassOrEnumParam)
15521 return Diag(FnDecl->getLocation(),
15522 diag::err_operator_overload_needs_class_or_enum)
15523 << FnDecl->getDeclName();
15524 }
15525
15526 // C++ [over.oper]p8:
15527 // An operator function cannot have default arguments (8.3.6),
15528 // except where explicitly stated below.
15529 //
15530 // Only the function-call operator allows default arguments
15531 // (C++ [over.call]p1).
15532 if (Op != OO_Call) {
15533 for (auto Param : FnDecl->parameters()) {
15534 if (Param->hasDefaultArg())
15535 return Diag(Param->getLocation(),
15536 diag::err_operator_overload_default_arg)
15537 << FnDecl->getDeclName() << Param->getDefaultArgRange();
15538 }
15539 }
15540
15541 static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
15542 { false, false, false }
15543 #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
15544 , { Unary, Binary, MemberOnly }
15545 #include "clang/Basic/OperatorKinds.def"
15546 };
15547
15548 bool CanBeUnaryOperator = OperatorUses[Op][0];
15549 bool CanBeBinaryOperator = OperatorUses[Op][1];
15550 bool MustBeMemberOperator = OperatorUses[Op][2];
15551
15552 // C++ [over.oper]p8:
15553 // [...] Operator functions cannot have more or fewer parameters
15554 // than the number required for the corresponding operator, as
15555 // described in the rest of this subclause.
15556 unsigned NumParams = FnDecl->getNumParams()
15557 + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
15558 if (Op != OO_Call &&
15559 ((NumParams == 1 && !CanBeUnaryOperator) ||
15560 (NumParams == 2 && !CanBeBinaryOperator) ||
15561 (NumParams < 1) || (NumParams > 2))) {
15562 // We have the wrong number of parameters.
15563 unsigned ErrorKind;
15564 if (CanBeUnaryOperator && CanBeBinaryOperator) {
15565 ErrorKind = 2; // 2 -> unary or binary.
15566 } else if (CanBeUnaryOperator) {
15567 ErrorKind = 0; // 0 -> unary
15568 } else {
15569 assert(CanBeBinaryOperator &&
15570 "All non-call overloaded operators are unary or binary!");
15571 ErrorKind = 1; // 1 -> binary
15572 }
15573
15574 return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
15575 << FnDecl->getDeclName() << NumParams << ErrorKind;
15576 }
15577
15578 // Overloaded operators other than operator() cannot be variadic.
15579 if (Op != OO_Call &&
15580 FnDecl->getType()->castAs<FunctionProtoType>()->isVariadic()) {
15581 return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
15582 << FnDecl->getDeclName();
15583 }
15584
15585 // Some operators must be non-static member functions.
15586 if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
15587 return Diag(FnDecl->getLocation(),
15588 diag::err_operator_overload_must_be_member)
15589 << FnDecl->getDeclName();
15590 }
15591
15592 // C++ [over.inc]p1:
15593 // The user-defined function called operator++ implements the
15594 // prefix and postfix ++ operator. If this function is a member
15595 // function with no parameters, or a non-member function with one
15596 // parameter of class or enumeration type, it defines the prefix
15597 // increment operator ++ for objects of that type. If the function
15598 // is a member function with one parameter (which shall be of type
15599 // int) or a non-member function with two parameters (the second
15600 // of which shall be of type int), it defines the postfix
15601 // increment operator ++ for objects of that type.
15602 if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
15603 ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
15604 QualType ParamType = LastParam->getType();
15605
15606 if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) &&
15607 !ParamType->isDependentType())
15608 return Diag(LastParam->getLocation(),
15609 diag::err_operator_overload_post_incdec_must_be_int)
15610 << LastParam->getType() << (Op == OO_MinusMinus);
15611 }
15612
15613 return false;
15614 }
15615
15616 static bool
checkLiteralOperatorTemplateParameterList(Sema & SemaRef,FunctionTemplateDecl * TpDecl)15617 checkLiteralOperatorTemplateParameterList(Sema &SemaRef,
15618 FunctionTemplateDecl *TpDecl) {
15619 TemplateParameterList *TemplateParams = TpDecl->getTemplateParameters();
15620
15621 // Must have one or two template parameters.
15622 if (TemplateParams->size() == 1) {
15623 NonTypeTemplateParmDecl *PmDecl =
15624 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(0));
15625
15626 // The template parameter must be a char parameter pack.
15627 if (PmDecl && PmDecl->isTemplateParameterPack() &&
15628 SemaRef.Context.hasSameType(PmDecl->getType(), SemaRef.Context.CharTy))
15629 return false;
15630
15631 // C++20 [over.literal]p5:
15632 // A string literal operator template is a literal operator template
15633 // whose template-parameter-list comprises a single non-type
15634 // template-parameter of class type.
15635 //
15636 // As a DR resolution, we also allow placeholders for deduced class
15637 // template specializations.
15638 if (SemaRef.getLangOpts().CPlusPlus20 &&
15639 !PmDecl->isTemplateParameterPack() &&
15640 (PmDecl->getType()->isRecordType() ||
15641 PmDecl->getType()->getAs<DeducedTemplateSpecializationType>()))
15642 return false;
15643 } else if (TemplateParams->size() == 2) {
15644 TemplateTypeParmDecl *PmType =
15645 dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(0));
15646 NonTypeTemplateParmDecl *PmArgs =
15647 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(1));
15648
15649 // The second template parameter must be a parameter pack with the
15650 // first template parameter as its type.
15651 if (PmType && PmArgs && !PmType->isTemplateParameterPack() &&
15652 PmArgs->isTemplateParameterPack()) {
15653 const TemplateTypeParmType *TArgs =
15654 PmArgs->getType()->getAs<TemplateTypeParmType>();
15655 if (TArgs && TArgs->getDepth() == PmType->getDepth() &&
15656 TArgs->getIndex() == PmType->getIndex()) {
15657 if (!SemaRef.inTemplateInstantiation())
15658 SemaRef.Diag(TpDecl->getLocation(),
15659 diag::ext_string_literal_operator_template);
15660 return false;
15661 }
15662 }
15663 }
15664
15665 SemaRef.Diag(TpDecl->getTemplateParameters()->getSourceRange().getBegin(),
15666 diag::err_literal_operator_template)
15667 << TpDecl->getTemplateParameters()->getSourceRange();
15668 return true;
15669 }
15670
15671 /// CheckLiteralOperatorDeclaration - Check whether the declaration
15672 /// of this literal operator function is well-formed. If so, returns
15673 /// false; otherwise, emits appropriate diagnostics and returns true.
CheckLiteralOperatorDeclaration(FunctionDecl * FnDecl)15674 bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
15675 if (isa<CXXMethodDecl>(FnDecl)) {
15676 Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
15677 << FnDecl->getDeclName();
15678 return true;
15679 }
15680
15681 if (FnDecl->isExternC()) {
15682 Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
15683 if (const LinkageSpecDecl *LSD =
15684 FnDecl->getDeclContext()->getExternCContext())
15685 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
15686 return true;
15687 }
15688
15689 // This might be the definition of a literal operator template.
15690 FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();
15691
15692 // This might be a specialization of a literal operator template.
15693 if (!TpDecl)
15694 TpDecl = FnDecl->getPrimaryTemplate();
15695
15696 // template <char...> type operator "" name() and
15697 // template <class T, T...> type operator "" name() are the only valid
15698 // template signatures, and the only valid signatures with no parameters.
15699 //
15700 // C++20 also allows template <SomeClass T> type operator "" name().
15701 if (TpDecl) {
15702 if (FnDecl->param_size() != 0) {
15703 Diag(FnDecl->getLocation(),
15704 diag::err_literal_operator_template_with_params);
15705 return true;
15706 }
15707
15708 if (checkLiteralOperatorTemplateParameterList(*this, TpDecl))
15709 return true;
15710
15711 } else if (FnDecl->param_size() == 1) {
15712 const ParmVarDecl *Param = FnDecl->getParamDecl(0);
15713
15714 QualType ParamType = Param->getType().getUnqualifiedType();
15715
15716 // Only unsigned long long int, long double, any character type, and const
15717 // char * are allowed as the only parameters.
15718 if (ParamType->isSpecificBuiltinType(BuiltinType::ULongLong) ||
15719 ParamType->isSpecificBuiltinType(BuiltinType::LongDouble) ||
15720 Context.hasSameType(ParamType, Context.CharTy) ||
15721 Context.hasSameType(ParamType, Context.WideCharTy) ||
15722 Context.hasSameType(ParamType, Context.Char8Ty) ||
15723 Context.hasSameType(ParamType, Context.Char16Ty) ||
15724 Context.hasSameType(ParamType, Context.Char32Ty)) {
15725 } else if (const PointerType *Ptr = ParamType->getAs<PointerType>()) {
15726 QualType InnerType = Ptr->getPointeeType();
15727
15728 // Pointer parameter must be a const char *.
15729 if (!(Context.hasSameType(InnerType.getUnqualifiedType(),
15730 Context.CharTy) &&
15731 InnerType.isConstQualified() && !InnerType.isVolatileQualified())) {
15732 Diag(Param->getSourceRange().getBegin(),
15733 diag::err_literal_operator_param)
15734 << ParamType << "'const char *'" << Param->getSourceRange();
15735 return true;
15736 }
15737
15738 } else if (ParamType->isRealFloatingType()) {
15739 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
15740 << ParamType << Context.LongDoubleTy << Param->getSourceRange();
15741 return true;
15742
15743 } else if (ParamType->isIntegerType()) {
15744 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
15745 << ParamType << Context.UnsignedLongLongTy << Param->getSourceRange();
15746 return true;
15747
15748 } else {
15749 Diag(Param->getSourceRange().getBegin(),
15750 diag::err_literal_operator_invalid_param)
15751 << ParamType << Param->getSourceRange();
15752 return true;
15753 }
15754
15755 } else if (FnDecl->param_size() == 2) {
15756 FunctionDecl::param_iterator Param = FnDecl->param_begin();
15757
15758 // First, verify that the first parameter is correct.
15759
15760 QualType FirstParamType = (*Param)->getType().getUnqualifiedType();
15761
15762 // Two parameter function must have a pointer to const as a
15763 // first parameter; let's strip those qualifiers.
15764 const PointerType *PT = FirstParamType->getAs<PointerType>();
15765
15766 if (!PT) {
15767 Diag((*Param)->getSourceRange().getBegin(),
15768 diag::err_literal_operator_param)
15769 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15770 return true;
15771 }
15772
15773 QualType PointeeType = PT->getPointeeType();
15774 // First parameter must be const
15775 if (!PointeeType.isConstQualified() || PointeeType.isVolatileQualified()) {
15776 Diag((*Param)->getSourceRange().getBegin(),
15777 diag::err_literal_operator_param)
15778 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15779 return true;
15780 }
15781
15782 QualType InnerType = PointeeType.getUnqualifiedType();
15783 // Only const char *, const wchar_t*, const char8_t*, const char16_t*, and
15784 // const char32_t* are allowed as the first parameter to a two-parameter
15785 // function
15786 if (!(Context.hasSameType(InnerType, Context.CharTy) ||
15787 Context.hasSameType(InnerType, Context.WideCharTy) ||
15788 Context.hasSameType(InnerType, Context.Char8Ty) ||
15789 Context.hasSameType(InnerType, Context.Char16Ty) ||
15790 Context.hasSameType(InnerType, Context.Char32Ty))) {
15791 Diag((*Param)->getSourceRange().getBegin(),
15792 diag::err_literal_operator_param)
15793 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15794 return true;
15795 }
15796
15797 // Move on to the second and final parameter.
15798 ++Param;
15799
15800 // The second parameter must be a std::size_t.
15801 QualType SecondParamType = (*Param)->getType().getUnqualifiedType();
15802 if (!Context.hasSameType(SecondParamType, Context.getSizeType())) {
15803 Diag((*Param)->getSourceRange().getBegin(),
15804 diag::err_literal_operator_param)
15805 << SecondParamType << Context.getSizeType()
15806 << (*Param)->getSourceRange();
15807 return true;
15808 }
15809 } else {
15810 Diag(FnDecl->getLocation(), diag::err_literal_operator_bad_param_count);
15811 return true;
15812 }
15813
15814 // Parameters are good.
15815
15816 // A parameter-declaration-clause containing a default argument is not
15817 // equivalent to any of the permitted forms.
15818 for (auto Param : FnDecl->parameters()) {
15819 if (Param->hasDefaultArg()) {
15820 Diag(Param->getDefaultArgRange().getBegin(),
15821 diag::err_literal_operator_default_argument)
15822 << Param->getDefaultArgRange();
15823 break;
15824 }
15825 }
15826
15827 StringRef LiteralName
15828 = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
15829 if (LiteralName[0] != '_' &&
15830 !getSourceManager().isInSystemHeader(FnDecl->getLocation())) {
15831 // C++11 [usrlit.suffix]p1:
15832 // Literal suffix identifiers that do not start with an underscore
15833 // are reserved for future standardization.
15834 Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved)
15835 << StringLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName);
15836 }
15837
15838 return false;
15839 }
15840
15841 /// ActOnStartLinkageSpecification - Parsed the beginning of a C++
15842 /// linkage specification, including the language and (if present)
15843 /// the '{'. ExternLoc is the location of the 'extern', Lang is the
15844 /// language string literal. LBraceLoc, if valid, provides the location of
15845 /// the '{' brace. Otherwise, this linkage specification does not
15846 /// have any braces.
ActOnStartLinkageSpecification(Scope * S,SourceLocation ExternLoc,Expr * LangStr,SourceLocation LBraceLoc)15847 Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
15848 Expr *LangStr,
15849 SourceLocation LBraceLoc) {
15850 StringLiteral *Lit = cast<StringLiteral>(LangStr);
15851 if (!Lit->isAscii()) {
15852 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii)
15853 << LangStr->getSourceRange();
15854 return nullptr;
15855 }
15856
15857 StringRef Lang = Lit->getString();
15858 LinkageSpecDecl::LanguageIDs Language;
15859 if (Lang == "C")
15860 Language = LinkageSpecDecl::lang_c;
15861 else if (Lang == "C++")
15862 Language = LinkageSpecDecl::lang_cxx;
15863 else {
15864 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown)
15865 << LangStr->getSourceRange();
15866 return nullptr;
15867 }
15868
15869 // FIXME: Add all the various semantics of linkage specifications
15870
15871 LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc,
15872 LangStr->getExprLoc(), Language,
15873 LBraceLoc.isValid());
15874 CurContext->addDecl(D);
15875 PushDeclContext(S, D);
15876 return D;
15877 }
15878
15879 /// ActOnFinishLinkageSpecification - Complete the definition of
15880 /// the C++ linkage specification LinkageSpec. If RBraceLoc is
15881 /// valid, it's the position of the closing '}' brace in a linkage
15882 /// specification that uses braces.
ActOnFinishLinkageSpecification(Scope * S,Decl * LinkageSpec,SourceLocation RBraceLoc)15883 Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
15884 Decl *LinkageSpec,
15885 SourceLocation RBraceLoc) {
15886 if (RBraceLoc.isValid()) {
15887 LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
15888 LSDecl->setRBraceLoc(RBraceLoc);
15889 }
15890 PopDeclContext();
15891 return LinkageSpec;
15892 }
15893
ActOnEmptyDeclaration(Scope * S,const ParsedAttributesView & AttrList,SourceLocation SemiLoc)15894 Decl *Sema::ActOnEmptyDeclaration(Scope *S,
15895 const ParsedAttributesView &AttrList,
15896 SourceLocation SemiLoc) {
15897 Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc);
15898 // Attribute declarations appertain to empty declaration so we handle
15899 // them here.
15900 ProcessDeclAttributeList(S, ED, AttrList);
15901
15902 CurContext->addDecl(ED);
15903 return ED;
15904 }
15905
15906 /// Perform semantic analysis for the variable declaration that
15907 /// occurs within a C++ catch clause, returning the newly-created
15908 /// variable.
BuildExceptionDeclaration(Scope * S,TypeSourceInfo * TInfo,SourceLocation StartLoc,SourceLocation Loc,IdentifierInfo * Name)15909 VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
15910 TypeSourceInfo *TInfo,
15911 SourceLocation StartLoc,
15912 SourceLocation Loc,
15913 IdentifierInfo *Name) {
15914 bool Invalid = false;
15915 QualType ExDeclType = TInfo->getType();
15916
15917 // Arrays and functions decay.
15918 if (ExDeclType->isArrayType())
15919 ExDeclType = Context.getArrayDecayedType(ExDeclType);
15920 else if (ExDeclType->isFunctionType())
15921 ExDeclType = Context.getPointerType(ExDeclType);
15922
15923 // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
15924 // The exception-declaration shall not denote a pointer or reference to an
15925 // incomplete type, other than [cv] void*.
15926 // N2844 forbids rvalue references.
15927 if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
15928 Diag(Loc, diag::err_catch_rvalue_ref);
15929 Invalid = true;
15930 }
15931
15932 if (ExDeclType->isVariablyModifiedType()) {
15933 Diag(Loc, diag::err_catch_variably_modified) << ExDeclType;
15934 Invalid = true;
15935 }
15936
15937 QualType BaseType = ExDeclType;
15938 int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
15939 unsigned DK = diag::err_catch_incomplete;
15940 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
15941 BaseType = Ptr->getPointeeType();
15942 Mode = 1;
15943 DK = diag::err_catch_incomplete_ptr;
15944 } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
15945 // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
15946 BaseType = Ref->getPointeeType();
15947 Mode = 2;
15948 DK = diag::err_catch_incomplete_ref;
15949 }
15950 if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
15951 !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
15952 Invalid = true;
15953
15954 if (!Invalid && Mode != 1 && BaseType->isSizelessType()) {
15955 Diag(Loc, diag::err_catch_sizeless) << (Mode == 2 ? 1 : 0) << BaseType;
15956 Invalid = true;
15957 }
15958
15959 if (!Invalid && !ExDeclType->isDependentType() &&
15960 RequireNonAbstractType(Loc, ExDeclType,
15961 diag::err_abstract_type_in_decl,
15962 AbstractVariableType))
15963 Invalid = true;
15964
15965 // Only the non-fragile NeXT runtime currently supports C++ catches
15966 // of ObjC types, and no runtime supports catching ObjC types by value.
15967 if (!Invalid && getLangOpts().ObjC) {
15968 QualType T = ExDeclType;
15969 if (const ReferenceType *RT = T->getAs<ReferenceType>())
15970 T = RT->getPointeeType();
15971
15972 if (T->isObjCObjectType()) {
15973 Diag(Loc, diag::err_objc_object_catch);
15974 Invalid = true;
15975 } else if (T->isObjCObjectPointerType()) {
15976 // FIXME: should this be a test for macosx-fragile specifically?
15977 if (getLangOpts().ObjCRuntime.isFragile())
15978 Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
15979 }
15980 }
15981
15982 VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
15983 ExDeclType, TInfo, SC_None);
15984 ExDecl->setExceptionVariable(true);
15985
15986 // In ARC, infer 'retaining' for variables of retainable type.
15987 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
15988 Invalid = true;
15989
15990 if (!Invalid && !ExDeclType->isDependentType()) {
15991 if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
15992 // Insulate this from anything else we might currently be parsing.
15993 EnterExpressionEvaluationContext scope(
15994 *this, ExpressionEvaluationContext::PotentiallyEvaluated);
15995
15996 // C++ [except.handle]p16:
15997 // The object declared in an exception-declaration or, if the
15998 // exception-declaration does not specify a name, a temporary (12.2) is
15999 // copy-initialized (8.5) from the exception object. [...]
16000 // The object is destroyed when the handler exits, after the destruction
16001 // of any automatic objects initialized within the handler.
16002 //
16003 // We just pretend to initialize the object with itself, then make sure
16004 // it can be destroyed later.
16005 QualType initType = Context.getExceptionObjectType(ExDeclType);
16006
16007 InitializedEntity entity =
16008 InitializedEntity::InitializeVariable(ExDecl);
16009 InitializationKind initKind =
16010 InitializationKind::CreateCopy(Loc, SourceLocation());
16011
16012 Expr *opaqueValue =
16013 new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
16014 InitializationSequence sequence(*this, entity, initKind, opaqueValue);
16015 ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue);
16016 if (result.isInvalid())
16017 Invalid = true;
16018 else {
16019 // If the constructor used was non-trivial, set this as the
16020 // "initializer".
16021 CXXConstructExpr *construct = result.getAs<CXXConstructExpr>();
16022 if (!construct->getConstructor()->isTrivial()) {
16023 Expr *init = MaybeCreateExprWithCleanups(construct);
16024 ExDecl->setInit(init);
16025 }
16026
16027 // And make sure it's destructable.
16028 FinalizeVarWithDestructor(ExDecl, recordType);
16029 }
16030 }
16031 }
16032
16033 if (Invalid)
16034 ExDecl->setInvalidDecl();
16035
16036 return ExDecl;
16037 }
16038
16039 /// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
16040 /// handler.
ActOnExceptionDeclarator(Scope * S,Declarator & D)16041 Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
16042 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
16043 bool Invalid = D.isInvalidType();
16044
16045 // Check for unexpanded parameter packs.
16046 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
16047 UPPC_ExceptionType)) {
16048 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
16049 D.getIdentifierLoc());
16050 Invalid = true;
16051 }
16052
16053 IdentifierInfo *II = D.getIdentifier();
16054 if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
16055 LookupOrdinaryName,
16056 ForVisibleRedeclaration)) {
16057 // The scope should be freshly made just for us. There is just no way
16058 // it contains any previous declaration, except for function parameters in
16059 // a function-try-block's catch statement.
16060 assert(!S->isDeclScope(PrevDecl));
16061 if (isDeclInScope(PrevDecl, CurContext, S)) {
16062 Diag(D.getIdentifierLoc(), diag::err_redefinition)
16063 << D.getIdentifier();
16064 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
16065 Invalid = true;
16066 } else if (PrevDecl->isTemplateParameter())
16067 // Maybe we will complain about the shadowed template parameter.
16068 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
16069 }
16070
16071 if (D.getCXXScopeSpec().isSet() && !Invalid) {
16072 Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
16073 << D.getCXXScopeSpec().getRange();
16074 Invalid = true;
16075 }
16076
16077 VarDecl *ExDecl = BuildExceptionDeclaration(
16078 S, TInfo, D.getBeginLoc(), D.getIdentifierLoc(), D.getIdentifier());
16079 if (Invalid)
16080 ExDecl->setInvalidDecl();
16081
16082 // Add the exception declaration into this scope.
16083 if (II)
16084 PushOnScopeChains(ExDecl, S);
16085 else
16086 CurContext->addDecl(ExDecl);
16087
16088 ProcessDeclAttributes(S, ExDecl, D);
16089 return ExDecl;
16090 }
16091
ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,Expr * AssertExpr,Expr * AssertMessageExpr,SourceLocation RParenLoc)16092 Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
16093 Expr *AssertExpr,
16094 Expr *AssertMessageExpr,
16095 SourceLocation RParenLoc) {
16096 StringLiteral *AssertMessage =
16097 AssertMessageExpr ? cast<StringLiteral>(AssertMessageExpr) : nullptr;
16098
16099 if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
16100 return nullptr;
16101
16102 return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr,
16103 AssertMessage, RParenLoc, false);
16104 }
16105
BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,Expr * AssertExpr,StringLiteral * AssertMessage,SourceLocation RParenLoc,bool Failed)16106 Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
16107 Expr *AssertExpr,
16108 StringLiteral *AssertMessage,
16109 SourceLocation RParenLoc,
16110 bool Failed) {
16111 assert(AssertExpr != nullptr && "Expected non-null condition");
16112 if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() &&
16113 !Failed) {
16114 // In a static_assert-declaration, the constant-expression shall be a
16115 // constant expression that can be contextually converted to bool.
16116 ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
16117 if (Converted.isInvalid())
16118 Failed = true;
16119
16120 ExprResult FullAssertExpr =
16121 ActOnFinishFullExpr(Converted.get(), StaticAssertLoc,
16122 /*DiscardedValue*/ false,
16123 /*IsConstexpr*/ true);
16124 if (FullAssertExpr.isInvalid())
16125 Failed = true;
16126 else
16127 AssertExpr = FullAssertExpr.get();
16128
16129 llvm::APSInt Cond;
16130 if (!Failed && VerifyIntegerConstantExpression(
16131 AssertExpr, &Cond,
16132 diag::err_static_assert_expression_is_not_constant)
16133 .isInvalid())
16134 Failed = true;
16135
16136 if (!Failed && !Cond) {
16137 SmallString<256> MsgBuffer;
16138 llvm::raw_svector_ostream Msg(MsgBuffer);
16139 if (AssertMessage)
16140 AssertMessage->printPretty(Msg, nullptr, getPrintingPolicy());
16141
16142 Expr *InnerCond = nullptr;
16143 std::string InnerCondDescription;
16144 std::tie(InnerCond, InnerCondDescription) =
16145 findFailedBooleanCondition(Converted.get());
16146 if (InnerCond && isa<ConceptSpecializationExpr>(InnerCond)) {
16147 // Drill down into concept specialization expressions to see why they
16148 // weren't satisfied.
16149 Diag(StaticAssertLoc, diag::err_static_assert_failed)
16150 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
16151 ConstraintSatisfaction Satisfaction;
16152 if (!CheckConstraintSatisfaction(InnerCond, Satisfaction))
16153 DiagnoseUnsatisfiedConstraint(Satisfaction);
16154 } else if (InnerCond && !isa<CXXBoolLiteralExpr>(InnerCond)
16155 && !isa<IntegerLiteral>(InnerCond)) {
16156 Diag(StaticAssertLoc, diag::err_static_assert_requirement_failed)
16157 << InnerCondDescription << !AssertMessage
16158 << Msg.str() << InnerCond->getSourceRange();
16159 } else {
16160 Diag(StaticAssertLoc, diag::err_static_assert_failed)
16161 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
16162 }
16163 Failed = true;
16164 }
16165 } else {
16166 ExprResult FullAssertExpr = ActOnFinishFullExpr(AssertExpr, StaticAssertLoc,
16167 /*DiscardedValue*/false,
16168 /*IsConstexpr*/true);
16169 if (FullAssertExpr.isInvalid())
16170 Failed = true;
16171 else
16172 AssertExpr = FullAssertExpr.get();
16173 }
16174
16175 Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
16176 AssertExpr, AssertMessage, RParenLoc,
16177 Failed);
16178
16179 CurContext->addDecl(Decl);
16180 return Decl;
16181 }
16182
16183 /// Perform semantic analysis of the given friend type declaration.
16184 ///
16185 /// \returns A friend declaration that.
CheckFriendTypeDecl(SourceLocation LocStart,SourceLocation FriendLoc,TypeSourceInfo * TSInfo)16186 FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart,
16187 SourceLocation FriendLoc,
16188 TypeSourceInfo *TSInfo) {
16189 assert(TSInfo && "NULL TypeSourceInfo for friend type declaration");
16190
16191 QualType T = TSInfo->getType();
16192 SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();
16193
16194 // C++03 [class.friend]p2:
16195 // An elaborated-type-specifier shall be used in a friend declaration
16196 // for a class.*
16197 //
16198 // * The class-key of the elaborated-type-specifier is required.
16199 if (!CodeSynthesisContexts.empty()) {
16200 // Do not complain about the form of friend template types during any kind
16201 // of code synthesis. For template instantiation, we will have complained
16202 // when the template was defined.
16203 } else {
16204 if (!T->isElaboratedTypeSpecifier()) {
16205 // If we evaluated the type to a record type, suggest putting
16206 // a tag in front.
16207 if (const RecordType *RT = T->getAs<RecordType>()) {
16208 RecordDecl *RD = RT->getDecl();
16209
16210 SmallString<16> InsertionText(" ");
16211 InsertionText += RD->getKindName();
16212
16213 Diag(TypeRange.getBegin(),
16214 getLangOpts().CPlusPlus11 ?
16215 diag::warn_cxx98_compat_unelaborated_friend_type :
16216 diag::ext_unelaborated_friend_type)
16217 << (unsigned) RD->getTagKind()
16218 << T
16219 << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc),
16220 InsertionText);
16221 } else {
16222 Diag(FriendLoc,
16223 getLangOpts().CPlusPlus11 ?
16224 diag::warn_cxx98_compat_nonclass_type_friend :
16225 diag::ext_nonclass_type_friend)
16226 << T
16227 << TypeRange;
16228 }
16229 } else if (T->getAs<EnumType>()) {
16230 Diag(FriendLoc,
16231 getLangOpts().CPlusPlus11 ?
16232 diag::warn_cxx98_compat_enum_friend :
16233 diag::ext_enum_friend)
16234 << T
16235 << TypeRange;
16236 }
16237
16238 // C++11 [class.friend]p3:
16239 // A friend declaration that does not declare a function shall have one
16240 // of the following forms:
16241 // friend elaborated-type-specifier ;
16242 // friend simple-type-specifier ;
16243 // friend typename-specifier ;
16244 if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc)
16245 Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T;
16246 }
16247
16248 // If the type specifier in a friend declaration designates a (possibly
16249 // cv-qualified) class type, that class is declared as a friend; otherwise,
16250 // the friend declaration is ignored.
16251 return FriendDecl::Create(Context, CurContext,
16252 TSInfo->getTypeLoc().getBeginLoc(), TSInfo,
16253 FriendLoc);
16254 }
16255
16256 /// Handle a friend tag declaration where the scope specifier was
16257 /// templated.
ActOnTemplatedFriendTag(Scope * S,SourceLocation FriendLoc,unsigned TagSpec,SourceLocation TagLoc,CXXScopeSpec & SS,IdentifierInfo * Name,SourceLocation NameLoc,const ParsedAttributesView & Attr,MultiTemplateParamsArg TempParamLists)16258 Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
16259 unsigned TagSpec, SourceLocation TagLoc,
16260 CXXScopeSpec &SS, IdentifierInfo *Name,
16261 SourceLocation NameLoc,
16262 const ParsedAttributesView &Attr,
16263 MultiTemplateParamsArg TempParamLists) {
16264 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
16265
16266 bool IsMemberSpecialization = false;
16267 bool Invalid = false;
16268
16269 if (TemplateParameterList *TemplateParams =
16270 MatchTemplateParametersToScopeSpecifier(
16271 TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true,
16272 IsMemberSpecialization, Invalid)) {
16273 if (TemplateParams->size() > 0) {
16274 // This is a declaration of a class template.
16275 if (Invalid)
16276 return nullptr;
16277
16278 return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name,
16279 NameLoc, Attr, TemplateParams, AS_public,
16280 /*ModulePrivateLoc=*/SourceLocation(),
16281 FriendLoc, TempParamLists.size() - 1,
16282 TempParamLists.data()).get();
16283 } else {
16284 // The "template<>" header is extraneous.
16285 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
16286 << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
16287 IsMemberSpecialization = true;
16288 }
16289 }
16290
16291 if (Invalid) return nullptr;
16292
16293 bool isAllExplicitSpecializations = true;
16294 for (unsigned I = TempParamLists.size(); I-- > 0; ) {
16295 if (TempParamLists[I]->size()) {
16296 isAllExplicitSpecializations = false;
16297 break;
16298 }
16299 }
16300
16301 // FIXME: don't ignore attributes.
16302
16303 // If it's explicit specializations all the way down, just forget
16304 // about the template header and build an appropriate non-templated
16305 // friend. TODO: for source fidelity, remember the headers.
16306 if (isAllExplicitSpecializations) {
16307 if (SS.isEmpty()) {
16308 bool Owned = false;
16309 bool IsDependent = false;
16310 return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
16311 Attr, AS_public,
16312 /*ModulePrivateLoc=*/SourceLocation(),
16313 MultiTemplateParamsArg(), Owned, IsDependent,
16314 /*ScopedEnumKWLoc=*/SourceLocation(),
16315 /*ScopedEnumUsesClassTag=*/false,
16316 /*UnderlyingType=*/TypeResult(),
16317 /*IsTypeSpecifier=*/false,
16318 /*IsTemplateParamOrArg=*/false);
16319 }
16320
16321 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
16322 ElaboratedTypeKeyword Keyword
16323 = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
16324 QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
16325 *Name, NameLoc);
16326 if (T.isNull())
16327 return nullptr;
16328
16329 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
16330 if (isa<DependentNameType>(T)) {
16331 DependentNameTypeLoc TL =
16332 TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
16333 TL.setElaboratedKeywordLoc(TagLoc);
16334 TL.setQualifierLoc(QualifierLoc);
16335 TL.setNameLoc(NameLoc);
16336 } else {
16337 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
16338 TL.setElaboratedKeywordLoc(TagLoc);
16339 TL.setQualifierLoc(QualifierLoc);
16340 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(NameLoc);
16341 }
16342
16343 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
16344 TSI, FriendLoc, TempParamLists);
16345 Friend->setAccess(AS_public);
16346 CurContext->addDecl(Friend);
16347 return Friend;
16348 }
16349
16350 assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?");
16351
16352
16353
16354 // Handle the case of a templated-scope friend class. e.g.
16355 // template <class T> class A<T>::B;
16356 // FIXME: we don't support these right now.
16357 Diag(NameLoc, diag::warn_template_qualified_friend_unsupported)
16358 << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext);
16359 ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
16360 QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
16361 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
16362 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
16363 TL.setElaboratedKeywordLoc(TagLoc);
16364 TL.setQualifierLoc(SS.getWithLocInContext(Context));
16365 TL.setNameLoc(NameLoc);
16366
16367 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
16368 TSI, FriendLoc, TempParamLists);
16369 Friend->setAccess(AS_public);
16370 Friend->setUnsupportedFriend(true);
16371 CurContext->addDecl(Friend);
16372 return Friend;
16373 }
16374
16375 /// Handle a friend type declaration. This works in tandem with
16376 /// ActOnTag.
16377 ///
16378 /// Notes on friend class templates:
16379 ///
16380 /// We generally treat friend class declarations as if they were
16381 /// declaring a class. So, for example, the elaborated type specifier
16382 /// in a friend declaration is required to obey the restrictions of a
16383 /// class-head (i.e. no typedefs in the scope chain), template
16384 /// parameters are required to match up with simple template-ids, &c.
16385 /// However, unlike when declaring a template specialization, it's
16386 /// okay to refer to a template specialization without an empty
16387 /// template parameter declaration, e.g.
16388 /// friend class A<T>::B<unsigned>;
16389 /// We permit this as a special case; if there are any template
16390 /// parameters present at all, require proper matching, i.e.
16391 /// template <> template \<class T> friend class A<int>::B;
ActOnFriendTypeDecl(Scope * S,const DeclSpec & DS,MultiTemplateParamsArg TempParams)16392 Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
16393 MultiTemplateParamsArg TempParams) {
16394 SourceLocation Loc = DS.getBeginLoc();
16395
16396 assert(DS.isFriendSpecified());
16397 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
16398
16399 // C++ [class.friend]p3:
16400 // A friend declaration that does not declare a function shall have one of
16401 // the following forms:
16402 // friend elaborated-type-specifier ;
16403 // friend simple-type-specifier ;
16404 // friend typename-specifier ;
16405 //
16406 // Any declaration with a type qualifier does not have that form. (It's
16407 // legal to specify a qualified type as a friend, you just can't write the
16408 // keywords.)
16409 if (DS.getTypeQualifiers()) {
16410 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
16411 Diag(DS.getConstSpecLoc(), diag::err_friend_decl_spec) << "const";
16412 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
16413 Diag(DS.getVolatileSpecLoc(), diag::err_friend_decl_spec) << "volatile";
16414 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
16415 Diag(DS.getRestrictSpecLoc(), diag::err_friend_decl_spec) << "restrict";
16416 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
16417 Diag(DS.getAtomicSpecLoc(), diag::err_friend_decl_spec) << "_Atomic";
16418 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
16419 Diag(DS.getUnalignedSpecLoc(), diag::err_friend_decl_spec) << "__unaligned";
16420 }
16421
16422 // Try to convert the decl specifier to a type. This works for
16423 // friend templates because ActOnTag never produces a ClassTemplateDecl
16424 // for a TUK_Friend.
16425 Declarator TheDeclarator(DS, DeclaratorContext::Member);
16426 TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
16427 QualType T = TSI->getType();
16428 if (TheDeclarator.isInvalidType())
16429 return nullptr;
16430
16431 if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
16432 return nullptr;
16433
16434 // This is definitely an error in C++98. It's probably meant to
16435 // be forbidden in C++0x, too, but the specification is just
16436 // poorly written.
16437 //
16438 // The problem is with declarations like the following:
16439 // template <T> friend A<T>::foo;
16440 // where deciding whether a class C is a friend or not now hinges
16441 // on whether there exists an instantiation of A that causes
16442 // 'foo' to equal C. There are restrictions on class-heads
16443 // (which we declare (by fiat) elaborated friend declarations to
16444 // be) that makes this tractable.
16445 //
16446 // FIXME: handle "template <> friend class A<T>;", which
16447 // is possibly well-formed? Who even knows?
16448 if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
16449 Diag(Loc, diag::err_tagless_friend_type_template)
16450 << DS.getSourceRange();
16451 return nullptr;
16452 }
16453
16454 // C++98 [class.friend]p1: A friend of a class is a function
16455 // or class that is not a member of the class . . .
16456 // This is fixed in DR77, which just barely didn't make the C++03
16457 // deadline. It's also a very silly restriction that seriously
16458 // affects inner classes and which nobody else seems to implement;
16459 // thus we never diagnose it, not even in -pedantic.
16460 //
16461 // But note that we could warn about it: it's always useless to
16462 // friend one of your own members (it's not, however, worthless to
16463 // friend a member of an arbitrary specialization of your template).
16464
16465 Decl *D;
16466 if (!TempParams.empty())
16467 D = FriendTemplateDecl::Create(Context, CurContext, Loc,
16468 TempParams,
16469 TSI,
16470 DS.getFriendSpecLoc());
16471 else
16472 D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);
16473
16474 if (!D)
16475 return nullptr;
16476
16477 D->setAccess(AS_public);
16478 CurContext->addDecl(D);
16479
16480 return D;
16481 }
16482
ActOnFriendFunctionDecl(Scope * S,Declarator & D,MultiTemplateParamsArg TemplateParams)16483 NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
16484 MultiTemplateParamsArg TemplateParams) {
16485 const DeclSpec &DS = D.getDeclSpec();
16486
16487 assert(DS.isFriendSpecified());
16488 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
16489
16490 SourceLocation Loc = D.getIdentifierLoc();
16491 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
16492
16493 // C++ [class.friend]p1
16494 // A friend of a class is a function or class....
16495 // Note that this sees through typedefs, which is intended.
16496 // It *doesn't* see through dependent types, which is correct
16497 // according to [temp.arg.type]p3:
16498 // If a declaration acquires a function type through a
16499 // type dependent on a template-parameter and this causes
16500 // a declaration that does not use the syntactic form of a
16501 // function declarator to have a function type, the program
16502 // is ill-formed.
16503 if (!TInfo->getType()->isFunctionType()) {
16504 Diag(Loc, diag::err_unexpected_friend);
16505
16506 // It might be worthwhile to try to recover by creating an
16507 // appropriate declaration.
16508 return nullptr;
16509 }
16510
16511 // C++ [namespace.memdef]p3
16512 // - If a friend declaration in a non-local class first declares a
16513 // class or function, the friend class or function is a member
16514 // of the innermost enclosing namespace.
16515 // - The name of the friend is not found by simple name lookup
16516 // until a matching declaration is provided in that namespace
16517 // scope (either before or after the class declaration granting
16518 // friendship).
16519 // - If a friend function is called, its name may be found by the
16520 // name lookup that considers functions from namespaces and
16521 // classes associated with the types of the function arguments.
16522 // - When looking for a prior declaration of a class or a function
16523 // declared as a friend, scopes outside the innermost enclosing
16524 // namespace scope are not considered.
16525
16526 CXXScopeSpec &SS = D.getCXXScopeSpec();
16527 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
16528 assert(NameInfo.getName());
16529
16530 // Check for unexpanded parameter packs.
16531 if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
16532 DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
16533 DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
16534 return nullptr;
16535
16536 // The context we found the declaration in, or in which we should
16537 // create the declaration.
16538 DeclContext *DC;
16539 Scope *DCScope = S;
16540 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
16541 ForExternalRedeclaration);
16542
16543 // There are five cases here.
16544 // - There's no scope specifier and we're in a local class. Only look
16545 // for functions declared in the immediately-enclosing block scope.
16546 // We recover from invalid scope qualifiers as if they just weren't there.
16547 FunctionDecl *FunctionContainingLocalClass = nullptr;
16548 if ((SS.isInvalid() || !SS.isSet()) &&
16549 (FunctionContainingLocalClass =
16550 cast<CXXRecordDecl>(CurContext)->isLocalClass())) {
16551 // C++11 [class.friend]p11:
16552 // If a friend declaration appears in a local class and the name
16553 // specified is an unqualified name, a prior declaration is
16554 // looked up without considering scopes that are outside the
16555 // innermost enclosing non-class scope. For a friend function
16556 // declaration, if there is no prior declaration, the program is
16557 // ill-formed.
16558
16559 // Find the innermost enclosing non-class scope. This is the block
16560 // scope containing the local class definition (or for a nested class,
16561 // the outer local class).
16562 DCScope = S->getFnParent();
16563
16564 // Look up the function name in the scope.
16565 Previous.clear(LookupLocalFriendName);
16566 LookupName(Previous, S, /*AllowBuiltinCreation*/false);
16567
16568 if (!Previous.empty()) {
16569 // All possible previous declarations must have the same context:
16570 // either they were declared at block scope or they are members of
16571 // one of the enclosing local classes.
16572 DC = Previous.getRepresentativeDecl()->getDeclContext();
16573 } else {
16574 // This is ill-formed, but provide the context that we would have
16575 // declared the function in, if we were permitted to, for error recovery.
16576 DC = FunctionContainingLocalClass;
16577 }
16578 adjustContextForLocalExternDecl(DC);
16579
16580 // C++ [class.friend]p6:
16581 // A function can be defined in a friend declaration of a class if and
16582 // only if the class is a non-local class (9.8), the function name is
16583 // unqualified, and the function has namespace scope.
16584 if (D.isFunctionDefinition()) {
16585 Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
16586 }
16587
16588 // - There's no scope specifier, in which case we just go to the
16589 // appropriate scope and look for a function or function template
16590 // there as appropriate.
16591 } else if (SS.isInvalid() || !SS.isSet()) {
16592 // C++11 [namespace.memdef]p3:
16593 // If the name in a friend declaration is neither qualified nor
16594 // a template-id and the declaration is a function or an
16595 // elaborated-type-specifier, the lookup to determine whether
16596 // the entity has been previously declared shall not consider
16597 // any scopes outside the innermost enclosing namespace.
16598 bool isTemplateId =
16599 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId;
16600
16601 // Find the appropriate context according to the above.
16602 DC = CurContext;
16603
16604 // Skip class contexts. If someone can cite chapter and verse
16605 // for this behavior, that would be nice --- it's what GCC and
16606 // EDG do, and it seems like a reasonable intent, but the spec
16607 // really only says that checks for unqualified existing
16608 // declarations should stop at the nearest enclosing namespace,
16609 // not that they should only consider the nearest enclosing
16610 // namespace.
16611 while (DC->isRecord())
16612 DC = DC->getParent();
16613
16614 DeclContext *LookupDC = DC;
16615 while (LookupDC->isTransparentContext())
16616 LookupDC = LookupDC->getParent();
16617
16618 while (true) {
16619 LookupQualifiedName(Previous, LookupDC);
16620
16621 if (!Previous.empty()) {
16622 DC = LookupDC;
16623 break;
16624 }
16625
16626 if (isTemplateId) {
16627 if (isa<TranslationUnitDecl>(LookupDC)) break;
16628 } else {
16629 if (LookupDC->isFileContext()) break;
16630 }
16631 LookupDC = LookupDC->getParent();
16632 }
16633
16634 DCScope = getScopeForDeclContext(S, DC);
16635
16636 // - There's a non-dependent scope specifier, in which case we
16637 // compute it and do a previous lookup there for a function
16638 // or function template.
16639 } else if (!SS.getScopeRep()->isDependent()) {
16640 DC = computeDeclContext(SS);
16641 if (!DC) return nullptr;
16642
16643 if (RequireCompleteDeclContext(SS, DC)) return nullptr;
16644
16645 LookupQualifiedName(Previous, DC);
16646
16647 // C++ [class.friend]p1: A friend of a class is a function or
16648 // class that is not a member of the class . . .
16649 if (DC->Equals(CurContext))
16650 Diag(DS.getFriendSpecLoc(),
16651 getLangOpts().CPlusPlus11 ?
16652 diag::warn_cxx98_compat_friend_is_member :
16653 diag::err_friend_is_member);
16654
16655 if (D.isFunctionDefinition()) {
16656 // C++ [class.friend]p6:
16657 // A function can be defined in a friend declaration of a class if and
16658 // only if the class is a non-local class (9.8), the function name is
16659 // unqualified, and the function has namespace scope.
16660 //
16661 // FIXME: We should only do this if the scope specifier names the
16662 // innermost enclosing namespace; otherwise the fixit changes the
16663 // meaning of the code.
16664 SemaDiagnosticBuilder DB
16665 = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);
16666
16667 DB << SS.getScopeRep();
16668 if (DC->isFileContext())
16669 DB << FixItHint::CreateRemoval(SS.getRange());
16670 SS.clear();
16671 }
16672
16673 // - There's a scope specifier that does not match any template
16674 // parameter lists, in which case we use some arbitrary context,
16675 // create a method or method template, and wait for instantiation.
16676 // - There's a scope specifier that does match some template
16677 // parameter lists, which we don't handle right now.
16678 } else {
16679 if (D.isFunctionDefinition()) {
16680 // C++ [class.friend]p6:
16681 // A function can be defined in a friend declaration of a class if and
16682 // only if the class is a non-local class (9.8), the function name is
16683 // unqualified, and the function has namespace scope.
16684 Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
16685 << SS.getScopeRep();
16686 }
16687
16688 DC = CurContext;
16689 assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?");
16690 }
16691
16692 if (!DC->isRecord()) {
16693 int DiagArg = -1;
16694 switch (D.getName().getKind()) {
16695 case UnqualifiedIdKind::IK_ConstructorTemplateId:
16696 case UnqualifiedIdKind::IK_ConstructorName:
16697 DiagArg = 0;
16698 break;
16699 case UnqualifiedIdKind::IK_DestructorName:
16700 DiagArg = 1;
16701 break;
16702 case UnqualifiedIdKind::IK_ConversionFunctionId:
16703 DiagArg = 2;
16704 break;
16705 case UnqualifiedIdKind::IK_DeductionGuideName:
16706 DiagArg = 3;
16707 break;
16708 case UnqualifiedIdKind::IK_Identifier:
16709 case UnqualifiedIdKind::IK_ImplicitSelfParam:
16710 case UnqualifiedIdKind::IK_LiteralOperatorId:
16711 case UnqualifiedIdKind::IK_OperatorFunctionId:
16712 case UnqualifiedIdKind::IK_TemplateId:
16713 break;
16714 }
16715 // This implies that it has to be an operator or function.
16716 if (DiagArg >= 0) {
16717 Diag(Loc, diag::err_introducing_special_friend) << DiagArg;
16718 return nullptr;
16719 }
16720 }
16721
16722 // FIXME: This is an egregious hack to cope with cases where the scope stack
16723 // does not contain the declaration context, i.e., in an out-of-line
16724 // definition of a class.
16725 Scope FakeDCScope(S, Scope::DeclScope, Diags);
16726 if (!DCScope) {
16727 FakeDCScope.setEntity(DC);
16728 DCScope = &FakeDCScope;
16729 }
16730
16731 bool AddToScope = true;
16732 NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
16733 TemplateParams, AddToScope);
16734 if (!ND) return nullptr;
16735
16736 assert(ND->getLexicalDeclContext() == CurContext);
16737
16738 // If we performed typo correction, we might have added a scope specifier
16739 // and changed the decl context.
16740 DC = ND->getDeclContext();
16741
16742 // Add the function declaration to the appropriate lookup tables,
16743 // adjusting the redeclarations list as necessary. We don't
16744 // want to do this yet if the friending class is dependent.
16745 //
16746 // Also update the scope-based lookup if the target context's
16747 // lookup context is in lexical scope.
16748 if (!CurContext->isDependentContext()) {
16749 DC = DC->getRedeclContext();
16750 DC->makeDeclVisibleInContext(ND);
16751 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
16752 PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
16753 }
16754
16755 FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
16756 D.getIdentifierLoc(), ND,
16757 DS.getFriendSpecLoc());
16758 FrD->setAccess(AS_public);
16759 CurContext->addDecl(FrD);
16760
16761 if (ND->isInvalidDecl()) {
16762 FrD->setInvalidDecl();
16763 } else {
16764 if (DC->isRecord()) CheckFriendAccess(ND);
16765
16766 FunctionDecl *FD;
16767 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
16768 FD = FTD->getTemplatedDecl();
16769 else
16770 FD = cast<FunctionDecl>(ND);
16771
16772 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a
16773 // default argument expression, that declaration shall be a definition
16774 // and shall be the only declaration of the function or function
16775 // template in the translation unit.
16776 if (functionDeclHasDefaultArgument(FD)) {
16777 // We can't look at FD->getPreviousDecl() because it may not have been set
16778 // if we're in a dependent context. If the function is known to be a
16779 // redeclaration, we will have narrowed Previous down to the right decl.
16780 if (D.isRedeclaration()) {
16781 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
16782 Diag(Previous.getRepresentativeDecl()->getLocation(),
16783 diag::note_previous_declaration);
16784 } else if (!D.isFunctionDefinition())
16785 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def);
16786 }
16787
16788 // Mark templated-scope function declarations as unsupported.
16789 if (FD->getNumTemplateParameterLists() && SS.isValid()) {
16790 Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported)
16791 << SS.getScopeRep() << SS.getRange()
16792 << cast<CXXRecordDecl>(CurContext);
16793 FrD->setUnsupportedFriend(true);
16794 }
16795 }
16796
16797 warnOnReservedIdentifier(ND);
16798
16799 return ND;
16800 }
16801
SetDeclDeleted(Decl * Dcl,SourceLocation DelLoc)16802 void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
16803 AdjustDeclIfTemplate(Dcl);
16804
16805 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(Dcl);
16806 if (!Fn) {
16807 Diag(DelLoc, diag::err_deleted_non_function);
16808 return;
16809 }
16810
16811 // Deleted function does not have a body.
16812 Fn->setWillHaveBody(false);
16813
16814 if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
16815 // Don't consider the implicit declaration we generate for explicit
16816 // specializations. FIXME: Do not generate these implicit declarations.
16817 if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization ||
16818 Prev->getPreviousDecl()) &&
16819 !Prev->isDefined()) {
16820 Diag(DelLoc, diag::err_deleted_decl_not_first);
16821 Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(),
16822 Prev->isImplicit() ? diag::note_previous_implicit_declaration
16823 : diag::note_previous_declaration);
16824 // We can't recover from this; the declaration might have already
16825 // been used.
16826 Fn->setInvalidDecl();
16827 return;
16828 }
16829
16830 // To maintain the invariant that functions are only deleted on their first
16831 // declaration, mark the implicitly-instantiated declaration of the
16832 // explicitly-specialized function as deleted instead of marking the
16833 // instantiated redeclaration.
16834 Fn = Fn->getCanonicalDecl();
16835 }
16836
16837 // dllimport/dllexport cannot be deleted.
16838 if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) {
16839 Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr;
16840 Fn->setInvalidDecl();
16841 }
16842
16843 // C++11 [basic.start.main]p3:
16844 // A program that defines main as deleted [...] is ill-formed.
16845 if (Fn->isMain())
16846 Diag(DelLoc, diag::err_deleted_main);
16847
16848 // C++11 [dcl.fct.def.delete]p4:
16849 // A deleted function is implicitly inline.
16850 Fn->setImplicitlyInline();
16851 Fn->setDeletedAsWritten();
16852 }
16853
SetDeclDefaulted(Decl * Dcl,SourceLocation DefaultLoc)16854 void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
16855 if (!Dcl || Dcl->isInvalidDecl())
16856 return;
16857
16858 auto *FD = dyn_cast<FunctionDecl>(Dcl);
16859 if (!FD) {
16860 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(Dcl)) {
16861 if (getDefaultedFunctionKind(FTD->getTemplatedDecl()).isComparison()) {
16862 Diag(DefaultLoc, diag::err_defaulted_comparison_template);
16863 return;
16864 }
16865 }
16866
16867 Diag(DefaultLoc, diag::err_default_special_members)
16868 << getLangOpts().CPlusPlus20;
16869 return;
16870 }
16871
16872 // Reject if this can't possibly be a defaultable function.
16873 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
16874 if (!DefKind &&
16875 // A dependent function that doesn't locally look defaultable can
16876 // still instantiate to a defaultable function if it's a constructor
16877 // or assignment operator.
16878 (!FD->isDependentContext() ||
16879 (!isa<CXXConstructorDecl>(FD) &&
16880 FD->getDeclName().getCXXOverloadedOperator() != OO_Equal))) {
16881 Diag(DefaultLoc, diag::err_default_special_members)
16882 << getLangOpts().CPlusPlus20;
16883 return;
16884 }
16885
16886 if (DefKind.isComparison() &&
16887 !isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
16888 Diag(FD->getLocation(), diag::err_defaulted_comparison_out_of_class)
16889 << (int)DefKind.asComparison();
16890 return;
16891 }
16892
16893 // Issue compatibility warning. We already warned if the operator is
16894 // 'operator<=>' when parsing the '<=>' token.
16895 if (DefKind.isComparison() &&
16896 DefKind.asComparison() != DefaultedComparisonKind::ThreeWay) {
16897 Diag(DefaultLoc, getLangOpts().CPlusPlus20
16898 ? diag::warn_cxx17_compat_defaulted_comparison
16899 : diag::ext_defaulted_comparison);
16900 }
16901
16902 FD->setDefaulted();
16903 FD->setExplicitlyDefaulted();
16904
16905 // Defer checking functions that are defaulted in a dependent context.
16906 if (FD->isDependentContext())
16907 return;
16908
16909 // Unset that we will have a body for this function. We might not,
16910 // if it turns out to be trivial, and we don't need this marking now
16911 // that we've marked it as defaulted.
16912 FD->setWillHaveBody(false);
16913
16914 // If this definition appears within the record, do the checking when
16915 // the record is complete. This is always the case for a defaulted
16916 // comparison.
16917 if (DefKind.isComparison())
16918 return;
16919 auto *MD = cast<CXXMethodDecl>(FD);
16920
16921 const FunctionDecl *Primary = FD;
16922 if (const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
16923 // Ask the template instantiation pattern that actually had the
16924 // '= default' on it.
16925 Primary = Pattern;
16926
16927 // If the method was defaulted on its first declaration, we will have
16928 // already performed the checking in CheckCompletedCXXClass. Such a
16929 // declaration doesn't trigger an implicit definition.
16930 if (Primary->getCanonicalDecl()->isDefaulted())
16931 return;
16932
16933 // FIXME: Once we support defining comparisons out of class, check for a
16934 // defaulted comparison here.
16935 if (CheckExplicitlyDefaultedSpecialMember(MD, DefKind.asSpecialMember()))
16936 MD->setInvalidDecl();
16937 else
16938 DefineDefaultedFunction(*this, MD, DefaultLoc);
16939 }
16940
SearchForReturnInStmt(Sema & Self,Stmt * S)16941 static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
16942 for (Stmt *SubStmt : S->children()) {
16943 if (!SubStmt)
16944 continue;
16945 if (isa<ReturnStmt>(SubStmt))
16946 Self.Diag(SubStmt->getBeginLoc(),
16947 diag::err_return_in_constructor_handler);
16948 if (!isa<Expr>(SubStmt))
16949 SearchForReturnInStmt(Self, SubStmt);
16950 }
16951 }
16952
DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt * TryBlock)16953 void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
16954 for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
16955 CXXCatchStmt *Handler = TryBlock->getHandler(I);
16956 SearchForReturnInStmt(*this, Handler);
16957 }
16958 }
16959
CheckOverridingFunctionAttributes(const CXXMethodDecl * New,const CXXMethodDecl * Old)16960 bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
16961 const CXXMethodDecl *Old) {
16962 const auto *NewFT = New->getType()->castAs<FunctionProtoType>();
16963 const auto *OldFT = Old->getType()->castAs<FunctionProtoType>();
16964
16965 if (OldFT->hasExtParameterInfos()) {
16966 for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
16967 // A parameter of the overriding method should be annotated with noescape
16968 // if the corresponding parameter of the overridden method is annotated.
16969 if (OldFT->getExtParameterInfo(I).isNoEscape() &&
16970 !NewFT->getExtParameterInfo(I).isNoEscape()) {
16971 Diag(New->getParamDecl(I)->getLocation(),
16972 diag::warn_overriding_method_missing_noescape);
16973 Diag(Old->getParamDecl(I)->getLocation(),
16974 diag::note_overridden_marked_noescape);
16975 }
16976 }
16977
16978 // Virtual overrides must have the same code_seg.
16979 const auto *OldCSA = Old->getAttr<CodeSegAttr>();
16980 const auto *NewCSA = New->getAttr<CodeSegAttr>();
16981 if ((NewCSA || OldCSA) &&
16982 (!OldCSA || !NewCSA || NewCSA->getName() != OldCSA->getName())) {
16983 Diag(New->getLocation(), diag::err_mismatched_code_seg_override);
16984 Diag(Old->getLocation(), diag::note_previous_declaration);
16985 return true;
16986 }
16987
16988 CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
16989
16990 // If the calling conventions match, everything is fine
16991 if (NewCC == OldCC)
16992 return false;
16993
16994 // If the calling conventions mismatch because the new function is static,
16995 // suppress the calling convention mismatch error; the error about static
16996 // function override (err_static_overrides_virtual from
16997 // Sema::CheckFunctionDeclaration) is more clear.
16998 if (New->getStorageClass() == SC_Static)
16999 return false;
17000
17001 Diag(New->getLocation(),
17002 diag::err_conflicting_overriding_cc_attributes)
17003 << New->getDeclName() << New->getType() << Old->getType();
17004 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
17005 return true;
17006 }
17007
CheckOverridingFunctionReturnType(const CXXMethodDecl * New,const CXXMethodDecl * Old)17008 bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
17009 const CXXMethodDecl *Old) {
17010 QualType NewTy = New->getType()->castAs<FunctionType>()->getReturnType();
17011 QualType OldTy = Old->getType()->castAs<FunctionType>()->getReturnType();
17012
17013 if (Context.hasSameType(NewTy, OldTy) ||
17014 NewTy->isDependentType() || OldTy->isDependentType())
17015 return false;
17016
17017 // Check if the return types are covariant
17018 QualType NewClassTy, OldClassTy;
17019
17020 /// Both types must be pointers or references to classes.
17021 if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
17022 if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
17023 NewClassTy = NewPT->getPointeeType();
17024 OldClassTy = OldPT->getPointeeType();
17025 }
17026 } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
17027 if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
17028 if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
17029 NewClassTy = NewRT->getPointeeType();
17030 OldClassTy = OldRT->getPointeeType();
17031 }
17032 }
17033 }
17034
17035 // The return types aren't either both pointers or references to a class type.
17036 if (NewClassTy.isNull()) {
17037 Diag(New->getLocation(),
17038 diag::err_different_return_type_for_overriding_virtual_function)
17039 << New->getDeclName() << NewTy << OldTy
17040 << New->getReturnTypeSourceRange();
17041 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17042 << Old->getReturnTypeSourceRange();
17043
17044 return true;
17045 }
17046
17047 if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
17048 // C++14 [class.virtual]p8:
17049 // If the class type in the covariant return type of D::f differs from
17050 // that of B::f, the class type in the return type of D::f shall be
17051 // complete at the point of declaration of D::f or shall be the class
17052 // type D.
17053 if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
17054 if (!RT->isBeingDefined() &&
17055 RequireCompleteType(New->getLocation(), NewClassTy,
17056 diag::err_covariant_return_incomplete,
17057 New->getDeclName()))
17058 return true;
17059 }
17060
17061 // Check if the new class derives from the old class.
17062 if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) {
17063 Diag(New->getLocation(), diag::err_covariant_return_not_derived)
17064 << New->getDeclName() << NewTy << OldTy
17065 << New->getReturnTypeSourceRange();
17066 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17067 << Old->getReturnTypeSourceRange();
17068 return true;
17069 }
17070
17071 // Check if we the conversion from derived to base is valid.
17072 if (CheckDerivedToBaseConversion(
17073 NewClassTy, OldClassTy,
17074 diag::err_covariant_return_inaccessible_base,
17075 diag::err_covariant_return_ambiguous_derived_to_base_conv,
17076 New->getLocation(), New->getReturnTypeSourceRange(),
17077 New->getDeclName(), nullptr)) {
17078 // FIXME: this note won't trigger for delayed access control
17079 // diagnostics, and it's impossible to get an undelayed error
17080 // here from access control during the original parse because
17081 // the ParsingDeclSpec/ParsingDeclarator are still in scope.
17082 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17083 << Old->getReturnTypeSourceRange();
17084 return true;
17085 }
17086 }
17087
17088 // The qualifiers of the return types must be the same.
17089 if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
17090 Diag(New->getLocation(),
17091 diag::err_covariant_return_type_different_qualifications)
17092 << New->getDeclName() << NewTy << OldTy
17093 << New->getReturnTypeSourceRange();
17094 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17095 << Old->getReturnTypeSourceRange();
17096 return true;
17097 }
17098
17099
17100 // The new class type must have the same or less qualifiers as the old type.
17101 if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
17102 Diag(New->getLocation(),
17103 diag::err_covariant_return_type_class_type_more_qualified)
17104 << New->getDeclName() << NewTy << OldTy
17105 << New->getReturnTypeSourceRange();
17106 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17107 << Old->getReturnTypeSourceRange();
17108 return true;
17109 }
17110
17111 return false;
17112 }
17113
17114 /// Mark the given method pure.
17115 ///
17116 /// \param Method the method to be marked pure.
17117 ///
17118 /// \param InitRange the source range that covers the "0" initializer.
CheckPureMethod(CXXMethodDecl * Method,SourceRange InitRange)17119 bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
17120 SourceLocation EndLoc = InitRange.getEnd();
17121 if (EndLoc.isValid())
17122 Method->setRangeEnd(EndLoc);
17123
17124 if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
17125 Method->setPure();
17126 return false;
17127 }
17128
17129 if (!Method->isInvalidDecl())
17130 Diag(Method->getLocation(), diag::err_non_virtual_pure)
17131 << Method->getDeclName() << InitRange;
17132 return true;
17133 }
17134
ActOnPureSpecifier(Decl * D,SourceLocation ZeroLoc)17135 void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) {
17136 if (D->getFriendObjectKind())
17137 Diag(D->getLocation(), diag::err_pure_friend);
17138 else if (auto *M = dyn_cast<CXXMethodDecl>(D))
17139 CheckPureMethod(M, ZeroLoc);
17140 else
17141 Diag(D->getLocation(), diag::err_illegal_initializer);
17142 }
17143
17144 /// Determine whether the given declaration is a global variable or
17145 /// static data member.
isNonlocalVariable(const Decl * D)17146 static bool isNonlocalVariable(const Decl *D) {
17147 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D))
17148 return Var->hasGlobalStorage();
17149
17150 return false;
17151 }
17152
17153 /// Invoked when we are about to parse an initializer for the declaration
17154 /// 'Dcl'.
17155 ///
17156 /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
17157 /// static data member of class X, names should be looked up in the scope of
17158 /// class X. If the declaration had a scope specifier, a scope will have
17159 /// been created and passed in for this purpose. Otherwise, S will be null.
ActOnCXXEnterDeclInitializer(Scope * S,Decl * D)17160 void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
17161 // If there is no declaration, there was an error parsing it.
17162 if (!D || D->isInvalidDecl())
17163 return;
17164
17165 // We will always have a nested name specifier here, but this declaration
17166 // might not be out of line if the specifier names the current namespace:
17167 // extern int n;
17168 // int ::n = 0;
17169 if (S && D->isOutOfLine())
17170 EnterDeclaratorContext(S, D->getDeclContext());
17171
17172 // If we are parsing the initializer for a static data member, push a
17173 // new expression evaluation context that is associated with this static
17174 // data member.
17175 if (isNonlocalVariable(D))
17176 PushExpressionEvaluationContext(
17177 ExpressionEvaluationContext::PotentiallyEvaluated, D);
17178 }
17179
17180 /// Invoked after we are finished parsing an initializer for the declaration D.
ActOnCXXExitDeclInitializer(Scope * S,Decl * D)17181 void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
17182 // If there is no declaration, there was an error parsing it.
17183 if (!D || D->isInvalidDecl())
17184 return;
17185
17186 if (isNonlocalVariable(D))
17187 PopExpressionEvaluationContext();
17188
17189 if (S && D->isOutOfLine())
17190 ExitDeclaratorContext(S);
17191 }
17192
17193 /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
17194 /// C++ if/switch/while/for statement.
17195 /// e.g: "if (int x = f()) {...}"
ActOnCXXConditionDeclaration(Scope * S,Declarator & D)17196 DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
17197 // C++ 6.4p2:
17198 // The declarator shall not specify a function or an array.
17199 // The type-specifier-seq shall not contain typedef and shall not declare a
17200 // new class or enumeration.
17201 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
17202 "Parser allowed 'typedef' as storage class of condition decl.");
17203
17204 Decl *Dcl = ActOnDeclarator(S, D);
17205 if (!Dcl)
17206 return true;
17207
17208 if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
17209 Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
17210 << D.getSourceRange();
17211 return true;
17212 }
17213
17214 return Dcl;
17215 }
17216
LoadExternalVTableUses()17217 void Sema::LoadExternalVTableUses() {
17218 if (!ExternalSource)
17219 return;
17220
17221 SmallVector<ExternalVTableUse, 4> VTables;
17222 ExternalSource->ReadUsedVTables(VTables);
17223 SmallVector<VTableUse, 4> NewUses;
17224 for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
17225 llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
17226 = VTablesUsed.find(VTables[I].Record);
17227 // Even if a definition wasn't required before, it may be required now.
17228 if (Pos != VTablesUsed.end()) {
17229 if (!Pos->second && VTables[I].DefinitionRequired)
17230 Pos->second = true;
17231 continue;
17232 }
17233
17234 VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
17235 NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
17236 }
17237
17238 VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
17239 }
17240
MarkVTableUsed(SourceLocation Loc,CXXRecordDecl * Class,bool DefinitionRequired)17241 void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
17242 bool DefinitionRequired) {
17243 // Ignore any vtable uses in unevaluated operands or for classes that do
17244 // not have a vtable.
17245 if (!Class->isDynamicClass() || Class->isDependentContext() ||
17246 CurContext->isDependentContext() || isUnevaluatedContext())
17247 return;
17248 // Do not mark as used if compiling for the device outside of the target
17249 // region.
17250 if (TUKind != TU_Prefix && LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
17251 !isInOpenMPDeclareTargetContext() &&
17252 !isInOpenMPTargetExecutionDirective()) {
17253 if (!DefinitionRequired)
17254 MarkVirtualMembersReferenced(Loc, Class);
17255 return;
17256 }
17257
17258 // Try to insert this class into the map.
17259 LoadExternalVTableUses();
17260 Class = Class->getCanonicalDecl();
17261 std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
17262 Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
17263 if (!Pos.second) {
17264 // If we already had an entry, check to see if we are promoting this vtable
17265 // to require a definition. If so, we need to reappend to the VTableUses
17266 // list, since we may have already processed the first entry.
17267 if (DefinitionRequired && !Pos.first->second) {
17268 Pos.first->second = true;
17269 } else {
17270 // Otherwise, we can early exit.
17271 return;
17272 }
17273 } else {
17274 // The Microsoft ABI requires that we perform the destructor body
17275 // checks (i.e. operator delete() lookup) when the vtable is marked used, as
17276 // the deleting destructor is emitted with the vtable, not with the
17277 // destructor definition as in the Itanium ABI.
17278 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
17279 CXXDestructorDecl *DD = Class->getDestructor();
17280 if (DD && DD->isVirtual() && !DD->isDeleted()) {
17281 if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) {
17282 // If this is an out-of-line declaration, marking it referenced will
17283 // not do anything. Manually call CheckDestructor to look up operator
17284 // delete().
17285 ContextRAII SavedContext(*this, DD);
17286 CheckDestructor(DD);
17287 } else {
17288 MarkFunctionReferenced(Loc, Class->getDestructor());
17289 }
17290 }
17291 }
17292 }
17293
17294 // Local classes need to have their virtual members marked
17295 // immediately. For all other classes, we mark their virtual members
17296 // at the end of the translation unit.
17297 if (Class->isLocalClass())
17298 MarkVirtualMembersReferenced(Loc, Class);
17299 else
17300 VTableUses.push_back(std::make_pair(Class, Loc));
17301 }
17302
DefineUsedVTables()17303 bool Sema::DefineUsedVTables() {
17304 LoadExternalVTableUses();
17305 if (VTableUses.empty())
17306 return false;
17307
17308 // Note: The VTableUses vector could grow as a result of marking
17309 // the members of a class as "used", so we check the size each
17310 // time through the loop and prefer indices (which are stable) to
17311 // iterators (which are not).
17312 bool DefinedAnything = false;
17313 for (unsigned I = 0; I != VTableUses.size(); ++I) {
17314 CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
17315 if (!Class)
17316 continue;
17317 TemplateSpecializationKind ClassTSK =
17318 Class->getTemplateSpecializationKind();
17319
17320 SourceLocation Loc = VTableUses[I].second;
17321
17322 bool DefineVTable = true;
17323
17324 // If this class has a key function, but that key function is
17325 // defined in another translation unit, we don't need to emit the
17326 // vtable even though we're using it.
17327 const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class);
17328 if (KeyFunction && !KeyFunction->hasBody()) {
17329 // The key function is in another translation unit.
17330 DefineVTable = false;
17331 TemplateSpecializationKind TSK =
17332 KeyFunction->getTemplateSpecializationKind();
17333 assert(TSK != TSK_ExplicitInstantiationDefinition &&
17334 TSK != TSK_ImplicitInstantiation &&
17335 "Instantiations don't have key functions");
17336 (void)TSK;
17337 } else if (!KeyFunction) {
17338 // If we have a class with no key function that is the subject
17339 // of an explicit instantiation declaration, suppress the
17340 // vtable; it will live with the explicit instantiation
17341 // definition.
17342 bool IsExplicitInstantiationDeclaration =
17343 ClassTSK == TSK_ExplicitInstantiationDeclaration;
17344 for (auto R : Class->redecls()) {
17345 TemplateSpecializationKind TSK
17346 = cast<CXXRecordDecl>(R)->getTemplateSpecializationKind();
17347 if (TSK == TSK_ExplicitInstantiationDeclaration)
17348 IsExplicitInstantiationDeclaration = true;
17349 else if (TSK == TSK_ExplicitInstantiationDefinition) {
17350 IsExplicitInstantiationDeclaration = false;
17351 break;
17352 }
17353 }
17354
17355 if (IsExplicitInstantiationDeclaration)
17356 DefineVTable = false;
17357 }
17358
17359 // The exception specifications for all virtual members may be needed even
17360 // if we are not providing an authoritative form of the vtable in this TU.
17361 // We may choose to emit it available_externally anyway.
17362 if (!DefineVTable) {
17363 MarkVirtualMemberExceptionSpecsNeeded(Loc, Class);
17364 continue;
17365 }
17366
17367 // Mark all of the virtual members of this class as referenced, so
17368 // that we can build a vtable. Then, tell the AST consumer that a
17369 // vtable for this class is required.
17370 DefinedAnything = true;
17371 MarkVirtualMembersReferenced(Loc, Class);
17372 CXXRecordDecl *Canonical = Class->getCanonicalDecl();
17373 if (VTablesUsed[Canonical])
17374 Consumer.HandleVTable(Class);
17375
17376 // Warn if we're emitting a weak vtable. The vtable will be weak if there is
17377 // no key function or the key function is inlined. Don't warn in C++ ABIs
17378 // that lack key functions, since the user won't be able to make one.
17379 if (Context.getTargetInfo().getCXXABI().hasKeyFunctions() &&
17380 Class->isExternallyVisible() && ClassTSK != TSK_ImplicitInstantiation) {
17381 const FunctionDecl *KeyFunctionDef = nullptr;
17382 if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) &&
17383 KeyFunctionDef->isInlined())) {
17384 Diag(Class->getLocation(),
17385 ClassTSK == TSK_ExplicitInstantiationDefinition
17386 ? diag::warn_weak_template_vtable
17387 : diag::warn_weak_vtable)
17388 << Class;
17389 }
17390 }
17391 }
17392 VTableUses.clear();
17393
17394 return DefinedAnything;
17395 }
17396
MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,const CXXRecordDecl * RD)17397 void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
17398 const CXXRecordDecl *RD) {
17399 for (const auto *I : RD->methods())
17400 if (I->isVirtual() && !I->isPure())
17401 ResolveExceptionSpec(Loc, I->getType()->castAs<FunctionProtoType>());
17402 }
17403
MarkVirtualMembersReferenced(SourceLocation Loc,const CXXRecordDecl * RD,bool ConstexprOnly)17404 void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
17405 const CXXRecordDecl *RD,
17406 bool ConstexprOnly) {
17407 // Mark all functions which will appear in RD's vtable as used.
17408 CXXFinalOverriderMap FinalOverriders;
17409 RD->getFinalOverriders(FinalOverriders);
17410 for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(),
17411 E = FinalOverriders.end();
17412 I != E; ++I) {
17413 for (OverridingMethods::const_iterator OI = I->second.begin(),
17414 OE = I->second.end();
17415 OI != OE; ++OI) {
17416 assert(OI->second.size() > 0 && "no final overrider");
17417 CXXMethodDecl *Overrider = OI->second.front().Method;
17418
17419 // C++ [basic.def.odr]p2:
17420 // [...] A virtual member function is used if it is not pure. [...]
17421 if (!Overrider->isPure() && (!ConstexprOnly || Overrider->isConstexpr()))
17422 MarkFunctionReferenced(Loc, Overrider);
17423 }
17424 }
17425
17426 // Only classes that have virtual bases need a VTT.
17427 if (RD->getNumVBases() == 0)
17428 return;
17429
17430 for (const auto &I : RD->bases()) {
17431 const auto *Base =
17432 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
17433 if (Base->getNumVBases() == 0)
17434 continue;
17435 MarkVirtualMembersReferenced(Loc, Base);
17436 }
17437 }
17438
17439 /// SetIvarInitializers - This routine builds initialization ASTs for the
17440 /// Objective-C implementation whose ivars need be initialized.
SetIvarInitializers(ObjCImplementationDecl * ObjCImplementation)17441 void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
17442 if (!getLangOpts().CPlusPlus)
17443 return;
17444 if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
17445 SmallVector<ObjCIvarDecl*, 8> ivars;
17446 CollectIvarsToConstructOrDestruct(OID, ivars);
17447 if (ivars.empty())
17448 return;
17449 SmallVector<CXXCtorInitializer*, 32> AllToInit;
17450 for (unsigned i = 0; i < ivars.size(); i++) {
17451 FieldDecl *Field = ivars[i];
17452 if (Field->isInvalidDecl())
17453 continue;
17454
17455 CXXCtorInitializer *Member;
17456 InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
17457 InitializationKind InitKind =
17458 InitializationKind::CreateDefault(ObjCImplementation->getLocation());
17459
17460 InitializationSequence InitSeq(*this, InitEntity, InitKind, None);
17461 ExprResult MemberInit =
17462 InitSeq.Perform(*this, InitEntity, InitKind, None);
17463 MemberInit = MaybeCreateExprWithCleanups(MemberInit);
17464 // Note, MemberInit could actually come back empty if no initialization
17465 // is required (e.g., because it would call a trivial default constructor)
17466 if (!MemberInit.get() || MemberInit.isInvalid())
17467 continue;
17468
17469 Member =
17470 new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
17471 SourceLocation(),
17472 MemberInit.getAs<Expr>(),
17473 SourceLocation());
17474 AllToInit.push_back(Member);
17475
17476 // Be sure that the destructor is accessible and is marked as referenced.
17477 if (const RecordType *RecordTy =
17478 Context.getBaseElementType(Field->getType())
17479 ->getAs<RecordType>()) {
17480 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
17481 if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
17482 MarkFunctionReferenced(Field->getLocation(), Destructor);
17483 CheckDestructorAccess(Field->getLocation(), Destructor,
17484 PDiag(diag::err_access_dtor_ivar)
17485 << Context.getBaseElementType(Field->getType()));
17486 }
17487 }
17488 }
17489 ObjCImplementation->setIvarInitializers(Context,
17490 AllToInit.data(), AllToInit.size());
17491 }
17492 }
17493
17494 static
DelegatingCycleHelper(CXXConstructorDecl * Ctor,llvm::SmallPtrSet<CXXConstructorDecl *,4> & Valid,llvm::SmallPtrSet<CXXConstructorDecl *,4> & Invalid,llvm::SmallPtrSet<CXXConstructorDecl *,4> & Current,Sema & S)17495 void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
17496 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Valid,
17497 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Invalid,
17498 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Current,
17499 Sema &S) {
17500 if (Ctor->isInvalidDecl())
17501 return;
17502
17503 CXXConstructorDecl *Target = Ctor->getTargetConstructor();
17504
17505 // Target may not be determinable yet, for instance if this is a dependent
17506 // call in an uninstantiated template.
17507 if (Target) {
17508 const FunctionDecl *FNTarget = nullptr;
17509 (void)Target->hasBody(FNTarget);
17510 Target = const_cast<CXXConstructorDecl*>(
17511 cast_or_null<CXXConstructorDecl>(FNTarget));
17512 }
17513
17514 CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
17515 // Avoid dereferencing a null pointer here.
17516 *TCanonical = Target? Target->getCanonicalDecl() : nullptr;
17517
17518 if (!Current.insert(Canonical).second)
17519 return;
17520
17521 // We know that beyond here, we aren't chaining into a cycle.
17522 if (!Target || !Target->isDelegatingConstructor() ||
17523 Target->isInvalidDecl() || Valid.count(TCanonical)) {
17524 Valid.insert(Current.begin(), Current.end());
17525 Current.clear();
17526 // We've hit a cycle.
17527 } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
17528 Current.count(TCanonical)) {
17529 // If we haven't diagnosed this cycle yet, do so now.
17530 if (!Invalid.count(TCanonical)) {
17531 S.Diag((*Ctor->init_begin())->getSourceLocation(),
17532 diag::warn_delegating_ctor_cycle)
17533 << Ctor;
17534
17535 // Don't add a note for a function delegating directly to itself.
17536 if (TCanonical != Canonical)
17537 S.Diag(Target->getLocation(), diag::note_it_delegates_to);
17538
17539 CXXConstructorDecl *C = Target;
17540 while (C->getCanonicalDecl() != Canonical) {
17541 const FunctionDecl *FNTarget = nullptr;
17542 (void)C->getTargetConstructor()->hasBody(FNTarget);
17543 assert(FNTarget && "Ctor cycle through bodiless function");
17544
17545 C = const_cast<CXXConstructorDecl*>(
17546 cast<CXXConstructorDecl>(FNTarget));
17547 S.Diag(C->getLocation(), diag::note_which_delegates_to);
17548 }
17549 }
17550
17551 Invalid.insert(Current.begin(), Current.end());
17552 Current.clear();
17553 } else {
17554 DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
17555 }
17556 }
17557
17558
CheckDelegatingCtorCycles()17559 void Sema::CheckDelegatingCtorCycles() {
17560 llvm::SmallPtrSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
17561
17562 for (DelegatingCtorDeclsType::iterator
17563 I = DelegatingCtorDecls.begin(ExternalSource),
17564 E = DelegatingCtorDecls.end();
17565 I != E; ++I)
17566 DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
17567
17568 for (auto CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
17569 (*CI)->setInvalidDecl();
17570 }
17571
17572 namespace {
17573 /// AST visitor that finds references to the 'this' expression.
17574 class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
17575 Sema &S;
17576
17577 public:
FindCXXThisExpr(Sema & S)17578 explicit FindCXXThisExpr(Sema &S) : S(S) { }
17579
VisitCXXThisExpr(CXXThisExpr * E)17580 bool VisitCXXThisExpr(CXXThisExpr *E) {
17581 S.Diag(E->getLocation(), diag::err_this_static_member_func)
17582 << E->isImplicit();
17583 return false;
17584 }
17585 };
17586 }
17587
checkThisInStaticMemberFunctionType(CXXMethodDecl * Method)17588 bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
17589 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
17590 if (!TSInfo)
17591 return false;
17592
17593 TypeLoc TL = TSInfo->getTypeLoc();
17594 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
17595 if (!ProtoTL)
17596 return false;
17597
17598 // C++11 [expr.prim.general]p3:
17599 // [The expression this] shall not appear before the optional
17600 // cv-qualifier-seq and it shall not appear within the declaration of a
17601 // static member function (although its type and value category are defined
17602 // within a static member function as they are within a non-static member
17603 // function). [ Note: this is because declaration matching does not occur
17604 // until the complete declarator is known. - end note ]
17605 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
17606 FindCXXThisExpr Finder(*this);
17607
17608 // If the return type came after the cv-qualifier-seq, check it now.
17609 if (Proto->hasTrailingReturn() &&
17610 !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc()))
17611 return true;
17612
17613 // Check the exception specification.
17614 if (checkThisInStaticMemberFunctionExceptionSpec(Method))
17615 return true;
17616
17617 // Check the trailing requires clause
17618 if (Expr *E = Method->getTrailingRequiresClause())
17619 if (!Finder.TraverseStmt(E))
17620 return true;
17621
17622 return checkThisInStaticMemberFunctionAttributes(Method);
17623 }
17624
checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl * Method)17625 bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
17626 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
17627 if (!TSInfo)
17628 return false;
17629
17630 TypeLoc TL = TSInfo->getTypeLoc();
17631 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
17632 if (!ProtoTL)
17633 return false;
17634
17635 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
17636 FindCXXThisExpr Finder(*this);
17637
17638 switch (Proto->getExceptionSpecType()) {
17639 case EST_Unparsed:
17640 case EST_Uninstantiated:
17641 case EST_Unevaluated:
17642 case EST_BasicNoexcept:
17643 case EST_NoThrow:
17644 case EST_DynamicNone:
17645 case EST_MSAny:
17646 case EST_None:
17647 break;
17648
17649 case EST_DependentNoexcept:
17650 case EST_NoexceptFalse:
17651 case EST_NoexceptTrue:
17652 if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
17653 return true;
17654 LLVM_FALLTHROUGH;
17655
17656 case EST_Dynamic:
17657 for (const auto &E : Proto->exceptions()) {
17658 if (!Finder.TraverseType(E))
17659 return true;
17660 }
17661 break;
17662 }
17663
17664 return false;
17665 }
17666
checkThisInStaticMemberFunctionAttributes(CXXMethodDecl * Method)17667 bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
17668 FindCXXThisExpr Finder(*this);
17669
17670 // Check attributes.
17671 for (const auto *A : Method->attrs()) {
17672 // FIXME: This should be emitted by tblgen.
17673 Expr *Arg = nullptr;
17674 ArrayRef<Expr *> Args;
17675 if (const auto *G = dyn_cast<GuardedByAttr>(A))
17676 Arg = G->getArg();
17677 else if (const auto *G = dyn_cast<PtGuardedByAttr>(A))
17678 Arg = G->getArg();
17679 else if (const auto *AA = dyn_cast<AcquiredAfterAttr>(A))
17680 Args = llvm::makeArrayRef(AA->args_begin(), AA->args_size());
17681 else if (const auto *AB = dyn_cast<AcquiredBeforeAttr>(A))
17682 Args = llvm::makeArrayRef(AB->args_begin(), AB->args_size());
17683 else if (const auto *ETLF = dyn_cast<ExclusiveTrylockFunctionAttr>(A)) {
17684 Arg = ETLF->getSuccessValue();
17685 Args = llvm::makeArrayRef(ETLF->args_begin(), ETLF->args_size());
17686 } else if (const auto *STLF = dyn_cast<SharedTrylockFunctionAttr>(A)) {
17687 Arg = STLF->getSuccessValue();
17688 Args = llvm::makeArrayRef(STLF->args_begin(), STLF->args_size());
17689 } else if (const auto *LR = dyn_cast<LockReturnedAttr>(A))
17690 Arg = LR->getArg();
17691 else if (const auto *LE = dyn_cast<LocksExcludedAttr>(A))
17692 Args = llvm::makeArrayRef(LE->args_begin(), LE->args_size());
17693 else if (const auto *RC = dyn_cast<RequiresCapabilityAttr>(A))
17694 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
17695 else if (const auto *AC = dyn_cast<AcquireCapabilityAttr>(A))
17696 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
17697 else if (const auto *AC = dyn_cast<TryAcquireCapabilityAttr>(A))
17698 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
17699 else if (const auto *RC = dyn_cast<ReleaseCapabilityAttr>(A))
17700 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
17701
17702 if (Arg && !Finder.TraverseStmt(Arg))
17703 return true;
17704
17705 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
17706 if (!Finder.TraverseStmt(Args[I]))
17707 return true;
17708 }
17709 }
17710
17711 return false;
17712 }
17713
checkExceptionSpecification(bool IsTopLevel,ExceptionSpecificationType EST,ArrayRef<ParsedType> DynamicExceptions,ArrayRef<SourceRange> DynamicExceptionRanges,Expr * NoexceptExpr,SmallVectorImpl<QualType> & Exceptions,FunctionProtoType::ExceptionSpecInfo & ESI)17714 void Sema::checkExceptionSpecification(
17715 bool IsTopLevel, ExceptionSpecificationType EST,
17716 ArrayRef<ParsedType> DynamicExceptions,
17717 ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr,
17718 SmallVectorImpl<QualType> &Exceptions,
17719 FunctionProtoType::ExceptionSpecInfo &ESI) {
17720 Exceptions.clear();
17721 ESI.Type = EST;
17722 if (EST == EST_Dynamic) {
17723 Exceptions.reserve(DynamicExceptions.size());
17724 for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
17725 // FIXME: Preserve type source info.
17726 QualType ET = GetTypeFromParser(DynamicExceptions[ei]);
17727
17728 if (IsTopLevel) {
17729 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
17730 collectUnexpandedParameterPacks(ET, Unexpanded);
17731 if (!Unexpanded.empty()) {
17732 DiagnoseUnexpandedParameterPacks(
17733 DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType,
17734 Unexpanded);
17735 continue;
17736 }
17737 }
17738
17739 // Check that the type is valid for an exception spec, and
17740 // drop it if not.
17741 if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
17742 Exceptions.push_back(ET);
17743 }
17744 ESI.Exceptions = Exceptions;
17745 return;
17746 }
17747
17748 if (isComputedNoexcept(EST)) {
17749 assert((NoexceptExpr->isTypeDependent() ||
17750 NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==
17751 Context.BoolTy) &&
17752 "Parser should have made sure that the expression is boolean");
17753 if (IsTopLevel && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
17754 ESI.Type = EST_BasicNoexcept;
17755 return;
17756 }
17757
17758 ESI.NoexceptExpr = NoexceptExpr;
17759 return;
17760 }
17761 }
17762
actOnDelayedExceptionSpecification(Decl * MethodD,ExceptionSpecificationType EST,SourceRange SpecificationRange,ArrayRef<ParsedType> DynamicExceptions,ArrayRef<SourceRange> DynamicExceptionRanges,Expr * NoexceptExpr)17763 void Sema::actOnDelayedExceptionSpecification(Decl *MethodD,
17764 ExceptionSpecificationType EST,
17765 SourceRange SpecificationRange,
17766 ArrayRef<ParsedType> DynamicExceptions,
17767 ArrayRef<SourceRange> DynamicExceptionRanges,
17768 Expr *NoexceptExpr) {
17769 if (!MethodD)
17770 return;
17771
17772 // Dig out the method we're referring to.
17773 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD))
17774 MethodD = FunTmpl->getTemplatedDecl();
17775
17776 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(MethodD);
17777 if (!Method)
17778 return;
17779
17780 // Check the exception specification.
17781 llvm::SmallVector<QualType, 4> Exceptions;
17782 FunctionProtoType::ExceptionSpecInfo ESI;
17783 checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions,
17784 DynamicExceptionRanges, NoexceptExpr, Exceptions,
17785 ESI);
17786
17787 // Update the exception specification on the function type.
17788 Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true);
17789
17790 if (Method->isStatic())
17791 checkThisInStaticMemberFunctionExceptionSpec(Method);
17792
17793 if (Method->isVirtual()) {
17794 // Check overrides, which we previously had to delay.
17795 for (const CXXMethodDecl *O : Method->overridden_methods())
17796 CheckOverridingFunctionExceptionSpec(Method, O);
17797 }
17798 }
17799
17800 /// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class.
17801 ///
HandleMSProperty(Scope * S,RecordDecl * Record,SourceLocation DeclStart,Declarator & D,Expr * BitWidth,InClassInitStyle InitStyle,AccessSpecifier AS,const ParsedAttr & MSPropertyAttr)17802 MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record,
17803 SourceLocation DeclStart, Declarator &D,
17804 Expr *BitWidth,
17805 InClassInitStyle InitStyle,
17806 AccessSpecifier AS,
17807 const ParsedAttr &MSPropertyAttr) {
17808 IdentifierInfo *II = D.getIdentifier();
17809 if (!II) {
17810 Diag(DeclStart, diag::err_anonymous_property);
17811 return nullptr;
17812 }
17813 SourceLocation Loc = D.getIdentifierLoc();
17814
17815 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
17816 QualType T = TInfo->getType();
17817 if (getLangOpts().CPlusPlus) {
17818 CheckExtraCXXDefaultArguments(D);
17819
17820 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
17821 UPPC_DataMemberType)) {
17822 D.setInvalidType();
17823 T = Context.IntTy;
17824 TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
17825 }
17826 }
17827
17828 DiagnoseFunctionSpecifiers(D.getDeclSpec());
17829
17830 if (D.getDeclSpec().isInlineSpecified())
17831 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
17832 << getLangOpts().CPlusPlus17;
17833 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
17834 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
17835 diag::err_invalid_thread)
17836 << DeclSpec::getSpecifierName(TSCS);
17837
17838 // Check to see if this name was declared as a member previously
17839 NamedDecl *PrevDecl = nullptr;
17840 LookupResult Previous(*this, II, Loc, LookupMemberName,
17841 ForVisibleRedeclaration);
17842 LookupName(Previous, S);
17843 switch (Previous.getResultKind()) {
17844 case LookupResult::Found:
17845 case LookupResult::FoundUnresolvedValue:
17846 PrevDecl = Previous.getAsSingle<NamedDecl>();
17847 break;
17848
17849 case LookupResult::FoundOverloaded:
17850 PrevDecl = Previous.getRepresentativeDecl();
17851 break;
17852
17853 case LookupResult::NotFound:
17854 case LookupResult::NotFoundInCurrentInstantiation:
17855 case LookupResult::Ambiguous:
17856 break;
17857 }
17858
17859 if (PrevDecl && PrevDecl->isTemplateParameter()) {
17860 // Maybe we will complain about the shadowed template parameter.
17861 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
17862 // Just pretend that we didn't see the previous declaration.
17863 PrevDecl = nullptr;
17864 }
17865
17866 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
17867 PrevDecl = nullptr;
17868
17869 SourceLocation TSSL = D.getBeginLoc();
17870 MSPropertyDecl *NewPD =
17871 MSPropertyDecl::Create(Context, Record, Loc, II, T, TInfo, TSSL,
17872 MSPropertyAttr.getPropertyDataGetter(),
17873 MSPropertyAttr.getPropertyDataSetter());
17874 ProcessDeclAttributes(TUScope, NewPD, D);
17875 NewPD->setAccess(AS);
17876
17877 if (NewPD->isInvalidDecl())
17878 Record->setInvalidDecl();
17879
17880 if (D.getDeclSpec().isModulePrivateSpecified())
17881 NewPD->setModulePrivate();
17882
17883 if (NewPD->isInvalidDecl() && PrevDecl) {
17884 // Don't introduce NewFD into scope; there's already something
17885 // with the same name in the same scope.
17886 } else if (II) {
17887 PushOnScopeChains(NewPD, S);
17888 } else
17889 Record->addDecl(NewPD);
17890
17891 return NewPD;
17892 }
17893
ActOnStartFunctionDeclarationDeclarator(Declarator & Declarator,unsigned TemplateParameterDepth)17894 void Sema::ActOnStartFunctionDeclarationDeclarator(
17895 Declarator &Declarator, unsigned TemplateParameterDepth) {
17896 auto &Info = InventedParameterInfos.emplace_back();
17897 TemplateParameterList *ExplicitParams = nullptr;
17898 ArrayRef<TemplateParameterList *> ExplicitLists =
17899 Declarator.getTemplateParameterLists();
17900 if (!ExplicitLists.empty()) {
17901 bool IsMemberSpecialization, IsInvalid;
17902 ExplicitParams = MatchTemplateParametersToScopeSpecifier(
17903 Declarator.getBeginLoc(), Declarator.getIdentifierLoc(),
17904 Declarator.getCXXScopeSpec(), /*TemplateId=*/nullptr,
17905 ExplicitLists, /*IsFriend=*/false, IsMemberSpecialization, IsInvalid,
17906 /*SuppressDiagnostic=*/true);
17907 }
17908 if (ExplicitParams) {
17909 Info.AutoTemplateParameterDepth = ExplicitParams->getDepth();
17910 for (NamedDecl *Param : *ExplicitParams)
17911 Info.TemplateParams.push_back(Param);
17912 Info.NumExplicitTemplateParams = ExplicitParams->size();
17913 } else {
17914 Info.AutoTemplateParameterDepth = TemplateParameterDepth;
17915 Info.NumExplicitTemplateParams = 0;
17916 }
17917 }
17918
ActOnFinishFunctionDeclarationDeclarator(Declarator & Declarator)17919 void Sema::ActOnFinishFunctionDeclarationDeclarator(Declarator &Declarator) {
17920 auto &FSI = InventedParameterInfos.back();
17921 if (FSI.TemplateParams.size() > FSI.NumExplicitTemplateParams) {
17922 if (FSI.NumExplicitTemplateParams != 0) {
17923 TemplateParameterList *ExplicitParams =
17924 Declarator.getTemplateParameterLists().back();
17925 Declarator.setInventedTemplateParameterList(
17926 TemplateParameterList::Create(
17927 Context, ExplicitParams->getTemplateLoc(),
17928 ExplicitParams->getLAngleLoc(), FSI.TemplateParams,
17929 ExplicitParams->getRAngleLoc(),
17930 ExplicitParams->getRequiresClause()));
17931 } else {
17932 Declarator.setInventedTemplateParameterList(
17933 TemplateParameterList::Create(
17934 Context, SourceLocation(), SourceLocation(), FSI.TemplateParams,
17935 SourceLocation(), /*RequiresClause=*/nullptr));
17936 }
17937 }
17938 InventedParameterInfos.pop_back();
17939 }
17940