1 //===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
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 /// \file
10 /// Implements semantic analysis for C++ expressions.
11 ///
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/Sema/Template.h"
15 #include "clang/Sema/SemaInternal.h"
16 #include "TreeTransform.h"
17 #include "TypeLocBuilder.h"
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/ASTLambda.h"
20 #include "clang/AST/CXXInheritance.h"
21 #include "clang/AST/CharUnits.h"
22 #include "clang/AST/DeclObjC.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/AST/ExprObjC.h"
25 #include "clang/AST/RecursiveASTVisitor.h"
26 #include "clang/AST/TypeLoc.h"
27 #include "clang/Basic/AlignedAllocation.h"
28 #include "clang/Basic/PartialDiagnostic.h"
29 #include "clang/Basic/TargetInfo.h"
30 #include "clang/Lex/Preprocessor.h"
31 #include "clang/Sema/DeclSpec.h"
32 #include "clang/Sema/Initialization.h"
33 #include "clang/Sema/Lookup.h"
34 #include "clang/Sema/ParsedTemplate.h"
35 #include "clang/Sema/Scope.h"
36 #include "clang/Sema/ScopeInfo.h"
37 #include "clang/Sema/SemaLambda.h"
38 #include "clang/Sema/TemplateDeduction.h"
39 #include "llvm/ADT/APInt.h"
40 #include "llvm/ADT/STLExtras.h"
41 #include "llvm/Support/ErrorHandling.h"
42 using namespace clang;
43 using namespace sema;
44
45 /// Handle the result of the special case name lookup for inheriting
46 /// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as
47 /// constructor names in member using declarations, even if 'X' is not the
48 /// name of the corresponding type.
getInheritingConstructorName(CXXScopeSpec & SS,SourceLocation NameLoc,IdentifierInfo & Name)49 ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS,
50 SourceLocation NameLoc,
51 IdentifierInfo &Name) {
52 NestedNameSpecifier *NNS = SS.getScopeRep();
53
54 // Convert the nested-name-specifier into a type.
55 QualType Type;
56 switch (NNS->getKind()) {
57 case NestedNameSpecifier::TypeSpec:
58 case NestedNameSpecifier::TypeSpecWithTemplate:
59 Type = QualType(NNS->getAsType(), 0);
60 break;
61
62 case NestedNameSpecifier::Identifier:
63 // Strip off the last layer of the nested-name-specifier and build a
64 // typename type for it.
65 assert(NNS->getAsIdentifier() == &Name && "not a constructor name");
66 Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(),
67 NNS->getAsIdentifier());
68 break;
69
70 case NestedNameSpecifier::Global:
71 case NestedNameSpecifier::Super:
72 case NestedNameSpecifier::Namespace:
73 case NestedNameSpecifier::NamespaceAlias:
74 llvm_unreachable("Nested name specifier is not a type for inheriting ctor");
75 }
76
77 // This reference to the type is located entirely at the location of the
78 // final identifier in the qualified-id.
79 return CreateParsedType(Type,
80 Context.getTrivialTypeSourceInfo(Type, NameLoc));
81 }
82
getConstructorName(IdentifierInfo & II,SourceLocation NameLoc,Scope * S,CXXScopeSpec & SS,bool EnteringContext)83 ParsedType Sema::getConstructorName(IdentifierInfo &II,
84 SourceLocation NameLoc,
85 Scope *S, CXXScopeSpec &SS,
86 bool EnteringContext) {
87 CXXRecordDecl *CurClass = getCurrentClass(S, &SS);
88 assert(CurClass && &II == CurClass->getIdentifier() &&
89 "not a constructor name");
90
91 // When naming a constructor as a member of a dependent context (eg, in a
92 // friend declaration or an inherited constructor declaration), form an
93 // unresolved "typename" type.
94 if (CurClass->isDependentContext() && !EnteringContext && SS.getScopeRep()) {
95 QualType T = Context.getDependentNameType(ETK_None, SS.getScopeRep(), &II);
96 return ParsedType::make(T);
97 }
98
99 if (SS.isNotEmpty() && RequireCompleteDeclContext(SS, CurClass))
100 return ParsedType();
101
102 // Find the injected-class-name declaration. Note that we make no attempt to
103 // diagnose cases where the injected-class-name is shadowed: the only
104 // declaration that can validly shadow the injected-class-name is a
105 // non-static data member, and if the class contains both a non-static data
106 // member and a constructor then it is ill-formed (we check that in
107 // CheckCompletedCXXClass).
108 CXXRecordDecl *InjectedClassName = nullptr;
109 for (NamedDecl *ND : CurClass->lookup(&II)) {
110 auto *RD = dyn_cast<CXXRecordDecl>(ND);
111 if (RD && RD->isInjectedClassName()) {
112 InjectedClassName = RD;
113 break;
114 }
115 }
116 if (!InjectedClassName) {
117 if (!CurClass->isInvalidDecl()) {
118 // FIXME: RequireCompleteDeclContext doesn't check dependent contexts
119 // properly. Work around it here for now.
120 Diag(SS.getLastQualifierNameLoc(),
121 diag::err_incomplete_nested_name_spec) << CurClass << SS.getRange();
122 }
123 return ParsedType();
124 }
125
126 QualType T = Context.getTypeDeclType(InjectedClassName);
127 DiagnoseUseOfDecl(InjectedClassName, NameLoc);
128 MarkAnyDeclReferenced(NameLoc, InjectedClassName, /*OdrUse=*/false);
129
130 return ParsedType::make(T);
131 }
132
getDestructorName(SourceLocation TildeLoc,IdentifierInfo & II,SourceLocation NameLoc,Scope * S,CXXScopeSpec & SS,ParsedType ObjectTypePtr,bool EnteringContext)133 ParsedType Sema::getDestructorName(SourceLocation TildeLoc,
134 IdentifierInfo &II,
135 SourceLocation NameLoc,
136 Scope *S, CXXScopeSpec &SS,
137 ParsedType ObjectTypePtr,
138 bool EnteringContext) {
139 // Determine where to perform name lookup.
140
141 // FIXME: This area of the standard is very messy, and the current
142 // wording is rather unclear about which scopes we search for the
143 // destructor name; see core issues 399 and 555. Issue 399 in
144 // particular shows where the current description of destructor name
145 // lookup is completely out of line with existing practice, e.g.,
146 // this appears to be ill-formed:
147 //
148 // namespace N {
149 // template <typename T> struct S {
150 // ~S();
151 // };
152 // }
153 //
154 // void f(N::S<int>* s) {
155 // s->N::S<int>::~S();
156 // }
157 //
158 // See also PR6358 and PR6359.
159 //
160 // For now, we accept all the cases in which the name given could plausibly
161 // be interpreted as a correct destructor name, issuing off-by-default
162 // extension diagnostics on the cases that don't strictly conform to the
163 // C++20 rules. This basically means we always consider looking in the
164 // nested-name-specifier prefix, the complete nested-name-specifier, and
165 // the scope, and accept if we find the expected type in any of the three
166 // places.
167
168 if (SS.isInvalid())
169 return nullptr;
170
171 // Whether we've failed with a diagnostic already.
172 bool Failed = false;
173
174 llvm::SmallVector<NamedDecl*, 8> FoundDecls;
175 llvm::SmallPtrSet<CanonicalDeclPtr<Decl>, 8> FoundDeclSet;
176
177 // If we have an object type, it's because we are in a
178 // pseudo-destructor-expression or a member access expression, and
179 // we know what type we're looking for.
180 QualType SearchType =
181 ObjectTypePtr ? GetTypeFromParser(ObjectTypePtr) : QualType();
182
183 auto CheckLookupResult = [&](LookupResult &Found) -> ParsedType {
184 auto IsAcceptableResult = [&](NamedDecl *D) -> bool {
185 auto *Type = dyn_cast<TypeDecl>(D->getUnderlyingDecl());
186 if (!Type)
187 return false;
188
189 if (SearchType.isNull() || SearchType->isDependentType())
190 return true;
191
192 QualType T = Context.getTypeDeclType(Type);
193 return Context.hasSameUnqualifiedType(T, SearchType);
194 };
195
196 unsigned NumAcceptableResults = 0;
197 for (NamedDecl *D : Found) {
198 if (IsAcceptableResult(D))
199 ++NumAcceptableResults;
200
201 // Don't list a class twice in the lookup failure diagnostic if it's
202 // found by both its injected-class-name and by the name in the enclosing
203 // scope.
204 if (auto *RD = dyn_cast<CXXRecordDecl>(D))
205 if (RD->isInjectedClassName())
206 D = cast<NamedDecl>(RD->getParent());
207
208 if (FoundDeclSet.insert(D).second)
209 FoundDecls.push_back(D);
210 }
211
212 // As an extension, attempt to "fix" an ambiguity by erasing all non-type
213 // results, and all non-matching results if we have a search type. It's not
214 // clear what the right behavior is if destructor lookup hits an ambiguity,
215 // but other compilers do generally accept at least some kinds of
216 // ambiguity.
217 if (Found.isAmbiguous() && NumAcceptableResults == 1) {
218 Diag(NameLoc, diag::ext_dtor_name_ambiguous);
219 LookupResult::Filter F = Found.makeFilter();
220 while (F.hasNext()) {
221 NamedDecl *D = F.next();
222 if (auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl()))
223 Diag(D->getLocation(), diag::note_destructor_type_here)
224 << Context.getTypeDeclType(TD);
225 else
226 Diag(D->getLocation(), diag::note_destructor_nontype_here);
227
228 if (!IsAcceptableResult(D))
229 F.erase();
230 }
231 F.done();
232 }
233
234 if (Found.isAmbiguous())
235 Failed = true;
236
237 if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
238 if (IsAcceptableResult(Type)) {
239 QualType T = Context.getTypeDeclType(Type);
240 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
241 return CreateParsedType(T,
242 Context.getTrivialTypeSourceInfo(T, NameLoc));
243 }
244 }
245
246 return nullptr;
247 };
248
249 bool IsDependent = false;
250
251 auto LookupInObjectType = [&]() -> ParsedType {
252 if (Failed || SearchType.isNull())
253 return nullptr;
254
255 IsDependent |= SearchType->isDependentType();
256
257 LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
258 DeclContext *LookupCtx = computeDeclContext(SearchType);
259 if (!LookupCtx)
260 return nullptr;
261 LookupQualifiedName(Found, LookupCtx);
262 return CheckLookupResult(Found);
263 };
264
265 auto LookupInNestedNameSpec = [&](CXXScopeSpec &LookupSS) -> ParsedType {
266 if (Failed)
267 return nullptr;
268
269 IsDependent |= isDependentScopeSpecifier(LookupSS);
270 DeclContext *LookupCtx = computeDeclContext(LookupSS, EnteringContext);
271 if (!LookupCtx)
272 return nullptr;
273
274 LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
275 if (RequireCompleteDeclContext(LookupSS, LookupCtx)) {
276 Failed = true;
277 return nullptr;
278 }
279 LookupQualifiedName(Found, LookupCtx);
280 return CheckLookupResult(Found);
281 };
282
283 auto LookupInScope = [&]() -> ParsedType {
284 if (Failed || !S)
285 return nullptr;
286
287 LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
288 LookupName(Found, S);
289 return CheckLookupResult(Found);
290 };
291
292 // C++2a [basic.lookup.qual]p6:
293 // In a qualified-id of the form
294 //
295 // nested-name-specifier[opt] type-name :: ~ type-name
296 //
297 // the second type-name is looked up in the same scope as the first.
298 //
299 // We interpret this as meaning that if you do a dual-scope lookup for the
300 // first name, you also do a dual-scope lookup for the second name, per
301 // C++ [basic.lookup.classref]p4:
302 //
303 // If the id-expression in a class member access is a qualified-id of the
304 // form
305 //
306 // class-name-or-namespace-name :: ...
307 //
308 // the class-name-or-namespace-name following the . or -> is first looked
309 // up in the class of the object expression and the name, if found, is used.
310 // Otherwise, it is looked up in the context of the entire
311 // postfix-expression.
312 //
313 // This looks in the same scopes as for an unqualified destructor name:
314 //
315 // C++ [basic.lookup.classref]p3:
316 // If the unqualified-id is ~ type-name, the type-name is looked up
317 // in the context of the entire postfix-expression. If the type T
318 // of the object expression is of a class type C, the type-name is
319 // also looked up in the scope of class C. At least one of the
320 // lookups shall find a name that refers to cv T.
321 //
322 // FIXME: The intent is unclear here. Should type-name::~type-name look in
323 // the scope anyway if it finds a non-matching name declared in the class?
324 // If both lookups succeed and find a dependent result, which result should
325 // we retain? (Same question for p->~type-name().)
326
327 if (NestedNameSpecifier *Prefix =
328 SS.isSet() ? SS.getScopeRep()->getPrefix() : nullptr) {
329 // This is
330 //
331 // nested-name-specifier type-name :: ~ type-name
332 //
333 // Look for the second type-name in the nested-name-specifier.
334 CXXScopeSpec PrefixSS;
335 PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
336 if (ParsedType T = LookupInNestedNameSpec(PrefixSS))
337 return T;
338 } else {
339 // This is one of
340 //
341 // type-name :: ~ type-name
342 // ~ type-name
343 //
344 // Look in the scope and (if any) the object type.
345 if (ParsedType T = LookupInScope())
346 return T;
347 if (ParsedType T = LookupInObjectType())
348 return T;
349 }
350
351 if (Failed)
352 return nullptr;
353
354 if (IsDependent) {
355 // We didn't find our type, but that's OK: it's dependent anyway.
356
357 // FIXME: What if we have no nested-name-specifier?
358 QualType T = CheckTypenameType(ETK_None, SourceLocation(),
359 SS.getWithLocInContext(Context),
360 II, NameLoc);
361 return ParsedType::make(T);
362 }
363
364 // The remaining cases are all non-standard extensions imitating the behavior
365 // of various other compilers.
366 unsigned NumNonExtensionDecls = FoundDecls.size();
367
368 if (SS.isSet()) {
369 // For compatibility with older broken C++ rules and existing code,
370 //
371 // nested-name-specifier :: ~ type-name
372 //
373 // also looks for type-name within the nested-name-specifier.
374 if (ParsedType T = LookupInNestedNameSpec(SS)) {
375 Diag(SS.getEndLoc(), diag::ext_dtor_named_in_wrong_scope)
376 << SS.getRange()
377 << FixItHint::CreateInsertion(SS.getEndLoc(),
378 ("::" + II.getName()).str());
379 return T;
380 }
381
382 // For compatibility with other compilers and older versions of Clang,
383 //
384 // nested-name-specifier type-name :: ~ type-name
385 //
386 // also looks for type-name in the scope. Unfortunately, we can't
387 // reasonably apply this fallback for dependent nested-name-specifiers.
388 if (SS.getScopeRep()->getPrefix()) {
389 if (ParsedType T = LookupInScope()) {
390 Diag(SS.getEndLoc(), diag::ext_qualified_dtor_named_in_lexical_scope)
391 << FixItHint::CreateRemoval(SS.getRange());
392 Diag(FoundDecls.back()->getLocation(), diag::note_destructor_type_here)
393 << GetTypeFromParser(T);
394 return T;
395 }
396 }
397 }
398
399 // We didn't find anything matching; tell the user what we did find (if
400 // anything).
401
402 // Don't tell the user about declarations we shouldn't have found.
403 FoundDecls.resize(NumNonExtensionDecls);
404
405 // List types before non-types.
406 std::stable_sort(FoundDecls.begin(), FoundDecls.end(),
407 [](NamedDecl *A, NamedDecl *B) {
408 return isa<TypeDecl>(A->getUnderlyingDecl()) >
409 isa<TypeDecl>(B->getUnderlyingDecl());
410 });
411
412 // Suggest a fixit to properly name the destroyed type.
413 auto MakeFixItHint = [&]{
414 const CXXRecordDecl *Destroyed = nullptr;
415 // FIXME: If we have a scope specifier, suggest its last component?
416 if (!SearchType.isNull())
417 Destroyed = SearchType->getAsCXXRecordDecl();
418 else if (S)
419 Destroyed = dyn_cast_or_null<CXXRecordDecl>(S->getEntity());
420 if (Destroyed)
421 return FixItHint::CreateReplacement(SourceRange(NameLoc),
422 Destroyed->getNameAsString());
423 return FixItHint();
424 };
425
426 if (FoundDecls.empty()) {
427 // FIXME: Attempt typo-correction?
428 Diag(NameLoc, diag::err_undeclared_destructor_name)
429 << &II << MakeFixItHint();
430 } else if (!SearchType.isNull() && FoundDecls.size() == 1) {
431 if (auto *TD = dyn_cast<TypeDecl>(FoundDecls[0]->getUnderlyingDecl())) {
432 assert(!SearchType.isNull() &&
433 "should only reject a type result if we have a search type");
434 QualType T = Context.getTypeDeclType(TD);
435 Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
436 << T << SearchType << MakeFixItHint();
437 } else {
438 Diag(NameLoc, diag::err_destructor_expr_nontype)
439 << &II << MakeFixItHint();
440 }
441 } else {
442 Diag(NameLoc, SearchType.isNull() ? diag::err_destructor_name_nontype
443 : diag::err_destructor_expr_mismatch)
444 << &II << SearchType << MakeFixItHint();
445 }
446
447 for (NamedDecl *FoundD : FoundDecls) {
448 if (auto *TD = dyn_cast<TypeDecl>(FoundD->getUnderlyingDecl()))
449 Diag(FoundD->getLocation(), diag::note_destructor_type_here)
450 << Context.getTypeDeclType(TD);
451 else
452 Diag(FoundD->getLocation(), diag::note_destructor_nontype_here)
453 << FoundD;
454 }
455
456 return nullptr;
457 }
458
getDestructorTypeForDecltype(const DeclSpec & DS,ParsedType ObjectType)459 ParsedType Sema::getDestructorTypeForDecltype(const DeclSpec &DS,
460 ParsedType ObjectType) {
461 if (DS.getTypeSpecType() == DeclSpec::TST_error)
462 return nullptr;
463
464 if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) {
465 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
466 return nullptr;
467 }
468
469 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype &&
470 "unexpected type in getDestructorType");
471 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
472
473 // If we know the type of the object, check that the correct destructor
474 // type was named now; we can give better diagnostics this way.
475 QualType SearchType = GetTypeFromParser(ObjectType);
476 if (!SearchType.isNull() && !SearchType->isDependentType() &&
477 !Context.hasSameUnqualifiedType(T, SearchType)) {
478 Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
479 << T << SearchType;
480 return nullptr;
481 }
482
483 return ParsedType::make(T);
484 }
485
checkLiteralOperatorId(const CXXScopeSpec & SS,const UnqualifiedId & Name,bool IsUDSuffix)486 bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS,
487 const UnqualifiedId &Name, bool IsUDSuffix) {
488 assert(Name.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId);
489 if (!IsUDSuffix) {
490 // [over.literal] p8
491 //
492 // double operator""_Bq(long double); // OK: not a reserved identifier
493 // double operator"" _Bq(long double); // ill-formed, no diagnostic required
494 IdentifierInfo *II = Name.Identifier;
495 ReservedIdentifierStatus Status = II->isReserved(PP.getLangOpts());
496 SourceLocation Loc = Name.getEndLoc();
497 if (isReservedInAllContexts(Status) &&
498 !PP.getSourceManager().isInSystemHeader(Loc)) {
499 Diag(Loc, diag::warn_reserved_extern_symbol)
500 << II << static_cast<int>(Status)
501 << FixItHint::CreateReplacement(
502 Name.getSourceRange(),
503 (StringRef("operator\"\"") + II->getName()).str());
504 }
505 }
506
507 if (!SS.isValid())
508 return false;
509
510 switch (SS.getScopeRep()->getKind()) {
511 case NestedNameSpecifier::Identifier:
512 case NestedNameSpecifier::TypeSpec:
513 case NestedNameSpecifier::TypeSpecWithTemplate:
514 // Per C++11 [over.literal]p2, literal operators can only be declared at
515 // namespace scope. Therefore, this unqualified-id cannot name anything.
516 // Reject it early, because we have no AST representation for this in the
517 // case where the scope is dependent.
518 Diag(Name.getBeginLoc(), diag::err_literal_operator_id_outside_namespace)
519 << SS.getScopeRep();
520 return true;
521
522 case NestedNameSpecifier::Global:
523 case NestedNameSpecifier::Super:
524 case NestedNameSpecifier::Namespace:
525 case NestedNameSpecifier::NamespaceAlias:
526 return false;
527 }
528
529 llvm_unreachable("unknown nested name specifier kind");
530 }
531
532 /// Build a C++ typeid expression with a type operand.
BuildCXXTypeId(QualType TypeInfoType,SourceLocation TypeidLoc,TypeSourceInfo * Operand,SourceLocation RParenLoc)533 ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
534 SourceLocation TypeidLoc,
535 TypeSourceInfo *Operand,
536 SourceLocation RParenLoc) {
537 // C++ [expr.typeid]p4:
538 // The top-level cv-qualifiers of the lvalue expression or the type-id
539 // that is the operand of typeid are always ignored.
540 // If the type of the type-id is a class type or a reference to a class
541 // type, the class shall be completely-defined.
542 Qualifiers Quals;
543 QualType T
544 = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
545 Quals);
546 if (T->getAs<RecordType>() &&
547 RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
548 return ExprError();
549
550 if (T->isVariablyModifiedType())
551 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);
552
553 if (CheckQualifiedFunctionForTypeId(T, TypeidLoc))
554 return ExprError();
555
556 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
557 SourceRange(TypeidLoc, RParenLoc));
558 }
559
560 /// Build a C++ typeid expression with an expression operand.
BuildCXXTypeId(QualType TypeInfoType,SourceLocation TypeidLoc,Expr * E,SourceLocation RParenLoc)561 ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
562 SourceLocation TypeidLoc,
563 Expr *E,
564 SourceLocation RParenLoc) {
565 bool WasEvaluated = false;
566 if (E && !E->isTypeDependent()) {
567 if (E->getType()->isPlaceholderType()) {
568 ExprResult result = CheckPlaceholderExpr(E);
569 if (result.isInvalid()) return ExprError();
570 E = result.get();
571 }
572
573 QualType T = E->getType();
574 if (const RecordType *RecordT = T->getAs<RecordType>()) {
575 CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
576 // C++ [expr.typeid]p3:
577 // [...] If the type of the expression is a class type, the class
578 // shall be completely-defined.
579 if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
580 return ExprError();
581
582 // C++ [expr.typeid]p3:
583 // When typeid is applied to an expression other than an glvalue of a
584 // polymorphic class type [...] [the] expression is an unevaluated
585 // operand. [...]
586 if (RecordD->isPolymorphic() && E->isGLValue()) {
587 if (isUnevaluatedContext()) {
588 // The operand was processed in unevaluated context, switch the
589 // context and recheck the subexpression.
590 ExprResult Result = TransformToPotentiallyEvaluated(E);
591 if (Result.isInvalid())
592 return ExprError();
593 E = Result.get();
594 }
595
596 // We require a vtable to query the type at run time.
597 MarkVTableUsed(TypeidLoc, RecordD);
598 WasEvaluated = true;
599 }
600 }
601
602 ExprResult Result = CheckUnevaluatedOperand(E);
603 if (Result.isInvalid())
604 return ExprError();
605 E = Result.get();
606
607 // C++ [expr.typeid]p4:
608 // [...] If the type of the type-id is a reference to a possibly
609 // cv-qualified type, the result of the typeid expression refers to a
610 // std::type_info object representing the cv-unqualified referenced
611 // type.
612 Qualifiers Quals;
613 QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
614 if (!Context.hasSameType(T, UnqualT)) {
615 T = UnqualT;
616 E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
617 }
618 }
619
620 if (E->getType()->isVariablyModifiedType())
621 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
622 << E->getType());
623 else if (!inTemplateInstantiation() &&
624 E->HasSideEffects(Context, WasEvaluated)) {
625 // The expression operand for typeid is in an unevaluated expression
626 // context, so side effects could result in unintended consequences.
627 Diag(E->getExprLoc(), WasEvaluated
628 ? diag::warn_side_effects_typeid
629 : diag::warn_side_effects_unevaluated_context);
630 }
631
632 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
633 SourceRange(TypeidLoc, RParenLoc));
634 }
635
636 /// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
637 ExprResult
ActOnCXXTypeid(SourceLocation OpLoc,SourceLocation LParenLoc,bool isType,void * TyOrExpr,SourceLocation RParenLoc)638 Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
639 bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
640 // typeid is not supported in OpenCL.
641 if (getLangOpts().OpenCLCPlusPlus) {
642 return ExprError(Diag(OpLoc, diag::err_openclcxx_not_supported)
643 << "typeid");
644 }
645
646 // Find the std::type_info type.
647 if (!getStdNamespace())
648 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
649
650 if (!CXXTypeInfoDecl) {
651 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
652 LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
653 LookupQualifiedName(R, getStdNamespace());
654 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
655 // Microsoft's typeinfo doesn't have type_info in std but in the global
656 // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
657 if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
658 LookupQualifiedName(R, Context.getTranslationUnitDecl());
659 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
660 }
661 if (!CXXTypeInfoDecl)
662 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
663 }
664
665 if (!getLangOpts().RTTI) {
666 return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
667 }
668
669 QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);
670
671 if (isType) {
672 // The operand is a type; handle it as such.
673 TypeSourceInfo *TInfo = nullptr;
674 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
675 &TInfo);
676 if (T.isNull())
677 return ExprError();
678
679 if (!TInfo)
680 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
681
682 return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
683 }
684
685 // The operand is an expression.
686 ExprResult Result =
687 BuildCXXTypeId(TypeInfoType, OpLoc, (Expr *)TyOrExpr, RParenLoc);
688
689 if (!getLangOpts().RTTIData && !Result.isInvalid())
690 if (auto *CTE = dyn_cast<CXXTypeidExpr>(Result.get()))
691 if (CTE->isPotentiallyEvaluated() && !CTE->isMostDerived(Context))
692 Diag(OpLoc, diag::warn_no_typeid_with_rtti_disabled)
693 << (getDiagnostics().getDiagnosticOptions().getFormat() ==
694 DiagnosticOptions::MSVC);
695 return Result;
696 }
697
698 /// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to
699 /// a single GUID.
700 static void
getUuidAttrOfType(Sema & SemaRef,QualType QT,llvm::SmallSetVector<const UuidAttr *,1> & UuidAttrs)701 getUuidAttrOfType(Sema &SemaRef, QualType QT,
702 llvm::SmallSetVector<const UuidAttr *, 1> &UuidAttrs) {
703 // Optionally remove one level of pointer, reference or array indirection.
704 const Type *Ty = QT.getTypePtr();
705 if (QT->isPointerType() || QT->isReferenceType())
706 Ty = QT->getPointeeType().getTypePtr();
707 else if (QT->isArrayType())
708 Ty = Ty->getBaseElementTypeUnsafe();
709
710 const auto *TD = Ty->getAsTagDecl();
711 if (!TD)
712 return;
713
714 if (const auto *Uuid = TD->getMostRecentDecl()->getAttr<UuidAttr>()) {
715 UuidAttrs.insert(Uuid);
716 return;
717 }
718
719 // __uuidof can grab UUIDs from template arguments.
720 if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(TD)) {
721 const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
722 for (const TemplateArgument &TA : TAL.asArray()) {
723 const UuidAttr *UuidForTA = nullptr;
724 if (TA.getKind() == TemplateArgument::Type)
725 getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs);
726 else if (TA.getKind() == TemplateArgument::Declaration)
727 getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs);
728
729 if (UuidForTA)
730 UuidAttrs.insert(UuidForTA);
731 }
732 }
733 }
734
735 /// Build a Microsoft __uuidof expression with a type operand.
BuildCXXUuidof(QualType Type,SourceLocation TypeidLoc,TypeSourceInfo * Operand,SourceLocation RParenLoc)736 ExprResult Sema::BuildCXXUuidof(QualType Type,
737 SourceLocation TypeidLoc,
738 TypeSourceInfo *Operand,
739 SourceLocation RParenLoc) {
740 MSGuidDecl *Guid = nullptr;
741 if (!Operand->getType()->isDependentType()) {
742 llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
743 getUuidAttrOfType(*this, Operand->getType(), UuidAttrs);
744 if (UuidAttrs.empty())
745 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
746 if (UuidAttrs.size() > 1)
747 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
748 Guid = UuidAttrs.back()->getGuidDecl();
749 }
750
751 return new (Context)
752 CXXUuidofExpr(Type, Operand, Guid, SourceRange(TypeidLoc, RParenLoc));
753 }
754
755 /// Build a Microsoft __uuidof expression with an expression operand.
BuildCXXUuidof(QualType Type,SourceLocation TypeidLoc,Expr * E,SourceLocation RParenLoc)756 ExprResult Sema::BuildCXXUuidof(QualType Type, SourceLocation TypeidLoc,
757 Expr *E, SourceLocation RParenLoc) {
758 MSGuidDecl *Guid = nullptr;
759 if (!E->getType()->isDependentType()) {
760 if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
761 // A null pointer results in {00000000-0000-0000-0000-000000000000}.
762 Guid = Context.getMSGuidDecl(MSGuidDecl::Parts{});
763 } else {
764 llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
765 getUuidAttrOfType(*this, E->getType(), UuidAttrs);
766 if (UuidAttrs.empty())
767 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
768 if (UuidAttrs.size() > 1)
769 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
770 Guid = UuidAttrs.back()->getGuidDecl();
771 }
772 }
773
774 return new (Context)
775 CXXUuidofExpr(Type, E, Guid, SourceRange(TypeidLoc, RParenLoc));
776 }
777
778 /// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
779 ExprResult
ActOnCXXUuidof(SourceLocation OpLoc,SourceLocation LParenLoc,bool isType,void * TyOrExpr,SourceLocation RParenLoc)780 Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc,
781 bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
782 QualType GuidType = Context.getMSGuidType();
783 GuidType.addConst();
784
785 if (isType) {
786 // The operand is a type; handle it as such.
787 TypeSourceInfo *TInfo = nullptr;
788 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
789 &TInfo);
790 if (T.isNull())
791 return ExprError();
792
793 if (!TInfo)
794 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
795
796 return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
797 }
798
799 // The operand is an expression.
800 return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
801 }
802
803 /// ActOnCXXBoolLiteral - Parse {true,false} literals.
804 ExprResult
ActOnCXXBoolLiteral(SourceLocation OpLoc,tok::TokenKind Kind)805 Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
806 assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
807 "Unknown C++ Boolean value!");
808 return new (Context)
809 CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
810 }
811
812 /// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
813 ExprResult
ActOnCXXNullPtrLiteral(SourceLocation Loc)814 Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
815 return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
816 }
817
818 /// ActOnCXXThrow - Parse throw expressions.
819 ExprResult
ActOnCXXThrow(Scope * S,SourceLocation OpLoc,Expr * Ex)820 Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) {
821 bool IsThrownVarInScope = false;
822 if (Ex) {
823 // C++0x [class.copymove]p31:
824 // When certain criteria are met, an implementation is allowed to omit the
825 // copy/move construction of a class object [...]
826 //
827 // - in a throw-expression, when the operand is the name of a
828 // non-volatile automatic object (other than a function or catch-
829 // clause parameter) whose scope does not extend beyond the end of the
830 // innermost enclosing try-block (if there is one), the copy/move
831 // operation from the operand to the exception object (15.1) can be
832 // omitted by constructing the automatic object directly into the
833 // exception object
834 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
835 if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
836 if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
837 for( ; S; S = S->getParent()) {
838 if (S->isDeclScope(Var)) {
839 IsThrownVarInScope = true;
840 break;
841 }
842
843 if (S->getFlags() &
844 (Scope::FnScope | Scope::ClassScope | Scope::BlockScope |
845 Scope::FunctionPrototypeScope | Scope::ObjCMethodScope |
846 Scope::TryScope))
847 break;
848 }
849 }
850 }
851 }
852
853 return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
854 }
855
BuildCXXThrow(SourceLocation OpLoc,Expr * Ex,bool IsThrownVarInScope)856 ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
857 bool IsThrownVarInScope) {
858 // Don't report an error if 'throw' is used in system headers.
859 if (!getLangOpts().CXXExceptions &&
860 !getSourceManager().isInSystemHeader(OpLoc) && !getLangOpts().CUDA) {
861 // Delay error emission for the OpenMP device code.
862 targetDiag(OpLoc, diag::err_exceptions_disabled) << "throw";
863 }
864
865 // Exceptions aren't allowed in CUDA device code.
866 if (getLangOpts().CUDA)
867 CUDADiagIfDeviceCode(OpLoc, diag::err_cuda_device_exceptions)
868 << "throw" << CurrentCUDATarget();
869
870 if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
871 Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";
872
873 if (Ex && !Ex->isTypeDependent()) {
874 // Initialize the exception result. This implicitly weeds out
875 // abstract types or types with inaccessible copy constructors.
876
877 // C++0x [class.copymove]p31:
878 // When certain criteria are met, an implementation is allowed to omit the
879 // copy/move construction of a class object [...]
880 //
881 // - in a throw-expression, when the operand is the name of a
882 // non-volatile automatic object (other than a function or
883 // catch-clause
884 // parameter) whose scope does not extend beyond the end of the
885 // innermost enclosing try-block (if there is one), the copy/move
886 // operation from the operand to the exception object (15.1) can be
887 // omitted by constructing the automatic object directly into the
888 // exception object
889 NamedReturnInfo NRInfo =
890 IsThrownVarInScope ? getNamedReturnInfo(Ex) : NamedReturnInfo();
891
892 QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
893 if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
894 return ExprError();
895
896 InitializedEntity Entity =
897 InitializedEntity::InitializeException(OpLoc, ExceptionObjectTy);
898 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRInfo, Ex);
899 if (Res.isInvalid())
900 return ExprError();
901 Ex = Res.get();
902 }
903
904 // PPC MMA non-pointer types are not allowed as throw expr types.
905 if (Ex && Context.getTargetInfo().getTriple().isPPC64())
906 CheckPPCMMAType(Ex->getType(), Ex->getBeginLoc());
907
908 return new (Context)
909 CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
910 }
911
912 static void
collectPublicBases(CXXRecordDecl * RD,llvm::DenseMap<CXXRecordDecl *,unsigned> & SubobjectsSeen,llvm::SmallPtrSetImpl<CXXRecordDecl * > & VBases,llvm::SetVector<CXXRecordDecl * > & PublicSubobjectsSeen,bool ParentIsPublic)913 collectPublicBases(CXXRecordDecl *RD,
914 llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen,
915 llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases,
916 llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen,
917 bool ParentIsPublic) {
918 for (const CXXBaseSpecifier &BS : RD->bases()) {
919 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
920 bool NewSubobject;
921 // Virtual bases constitute the same subobject. Non-virtual bases are
922 // always distinct subobjects.
923 if (BS.isVirtual())
924 NewSubobject = VBases.insert(BaseDecl).second;
925 else
926 NewSubobject = true;
927
928 if (NewSubobject)
929 ++SubobjectsSeen[BaseDecl];
930
931 // Only add subobjects which have public access throughout the entire chain.
932 bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public;
933 if (PublicPath)
934 PublicSubobjectsSeen.insert(BaseDecl);
935
936 // Recurse on to each base subobject.
937 collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen,
938 PublicPath);
939 }
940 }
941
getUnambiguousPublicSubobjects(CXXRecordDecl * RD,llvm::SmallVectorImpl<CXXRecordDecl * > & Objects)942 static void getUnambiguousPublicSubobjects(
943 CXXRecordDecl *RD, llvm::SmallVectorImpl<CXXRecordDecl *> &Objects) {
944 llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen;
945 llvm::SmallSet<CXXRecordDecl *, 2> VBases;
946 llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen;
947 SubobjectsSeen[RD] = 1;
948 PublicSubobjectsSeen.insert(RD);
949 collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen,
950 /*ParentIsPublic=*/true);
951
952 for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) {
953 // Skip ambiguous objects.
954 if (SubobjectsSeen[PublicSubobject] > 1)
955 continue;
956
957 Objects.push_back(PublicSubobject);
958 }
959 }
960
961 /// CheckCXXThrowOperand - Validate the operand of a throw.
CheckCXXThrowOperand(SourceLocation ThrowLoc,QualType ExceptionObjectTy,Expr * E)962 bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc,
963 QualType ExceptionObjectTy, Expr *E) {
964 // If the type of the exception would be an incomplete type or a pointer
965 // to an incomplete type other than (cv) void the program is ill-formed.
966 QualType Ty = ExceptionObjectTy;
967 bool isPointer = false;
968 if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
969 Ty = Ptr->getPointeeType();
970 isPointer = true;
971 }
972 if (!isPointer || !Ty->isVoidType()) {
973 if (RequireCompleteType(ThrowLoc, Ty,
974 isPointer ? diag::err_throw_incomplete_ptr
975 : diag::err_throw_incomplete,
976 E->getSourceRange()))
977 return true;
978
979 if (!isPointer && Ty->isSizelessType()) {
980 Diag(ThrowLoc, diag::err_throw_sizeless) << Ty << E->getSourceRange();
981 return true;
982 }
983
984 if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy,
985 diag::err_throw_abstract_type, E))
986 return true;
987 }
988
989 // If the exception has class type, we need additional handling.
990 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
991 if (!RD)
992 return false;
993
994 // If we are throwing a polymorphic class type or pointer thereof,
995 // exception handling will make use of the vtable.
996 MarkVTableUsed(ThrowLoc, RD);
997
998 // If a pointer is thrown, the referenced object will not be destroyed.
999 if (isPointer)
1000 return false;
1001
1002 // If the class has a destructor, we must be able to call it.
1003 if (!RD->hasIrrelevantDestructor()) {
1004 if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
1005 MarkFunctionReferenced(E->getExprLoc(), Destructor);
1006 CheckDestructorAccess(E->getExprLoc(), Destructor,
1007 PDiag(diag::err_access_dtor_exception) << Ty);
1008 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
1009 return true;
1010 }
1011 }
1012
1013 // The MSVC ABI creates a list of all types which can catch the exception
1014 // object. This list also references the appropriate copy constructor to call
1015 // if the object is caught by value and has a non-trivial copy constructor.
1016 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1017 // We are only interested in the public, unambiguous bases contained within
1018 // the exception object. Bases which are ambiguous or otherwise
1019 // inaccessible are not catchable types.
1020 llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects;
1021 getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects);
1022
1023 for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) {
1024 // Attempt to lookup the copy constructor. Various pieces of machinery
1025 // will spring into action, like template instantiation, which means this
1026 // cannot be a simple walk of the class's decls. Instead, we must perform
1027 // lookup and overload resolution.
1028 CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
1029 if (!CD || CD->isDeleted())
1030 continue;
1031
1032 // Mark the constructor referenced as it is used by this throw expression.
1033 MarkFunctionReferenced(E->getExprLoc(), CD);
1034
1035 // Skip this copy constructor if it is trivial, we don't need to record it
1036 // in the catchable type data.
1037 if (CD->isTrivial())
1038 continue;
1039
1040 // The copy constructor is non-trivial, create a mapping from this class
1041 // type to this constructor.
1042 // N.B. The selection of copy constructor is not sensitive to this
1043 // particular throw-site. Lookup will be performed at the catch-site to
1044 // ensure that the copy constructor is, in fact, accessible (via
1045 // friendship or any other means).
1046 Context.addCopyConstructorForExceptionObject(Subobject, CD);
1047
1048 // We don't keep the instantiated default argument expressions around so
1049 // we must rebuild them here.
1050 for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) {
1051 if (CheckCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)))
1052 return true;
1053 }
1054 }
1055 }
1056
1057 // Under the Itanium C++ ABI, memory for the exception object is allocated by
1058 // the runtime with no ability for the compiler to request additional
1059 // alignment. Warn if the exception type requires alignment beyond the minimum
1060 // guaranteed by the target C++ runtime.
1061 if (Context.getTargetInfo().getCXXABI().isItaniumFamily()) {
1062 CharUnits TypeAlign = Context.getTypeAlignInChars(Ty);
1063 CharUnits ExnObjAlign = Context.getExnObjectAlignment();
1064 if (ExnObjAlign < TypeAlign) {
1065 Diag(ThrowLoc, diag::warn_throw_underaligned_obj);
1066 Diag(ThrowLoc, diag::note_throw_underaligned_obj)
1067 << Ty << (unsigned)TypeAlign.getQuantity()
1068 << (unsigned)ExnObjAlign.getQuantity();
1069 }
1070 }
1071
1072 return false;
1073 }
1074
adjustCVQualifiersForCXXThisWithinLambda(ArrayRef<FunctionScopeInfo * > FunctionScopes,QualType ThisTy,DeclContext * CurSemaContext,ASTContext & ASTCtx)1075 static QualType adjustCVQualifiersForCXXThisWithinLambda(
1076 ArrayRef<FunctionScopeInfo *> FunctionScopes, QualType ThisTy,
1077 DeclContext *CurSemaContext, ASTContext &ASTCtx) {
1078
1079 QualType ClassType = ThisTy->getPointeeType();
1080 LambdaScopeInfo *CurLSI = nullptr;
1081 DeclContext *CurDC = CurSemaContext;
1082
1083 // Iterate through the stack of lambdas starting from the innermost lambda to
1084 // the outermost lambda, checking if '*this' is ever captured by copy - since
1085 // that could change the cv-qualifiers of the '*this' object.
1086 // The object referred to by '*this' starts out with the cv-qualifiers of its
1087 // member function. We then start with the innermost lambda and iterate
1088 // outward checking to see if any lambda performs a by-copy capture of '*this'
1089 // - and if so, any nested lambda must respect the 'constness' of that
1090 // capturing lamdbda's call operator.
1091 //
1092
1093 // Since the FunctionScopeInfo stack is representative of the lexical
1094 // nesting of the lambda expressions during initial parsing (and is the best
1095 // place for querying information about captures about lambdas that are
1096 // partially processed) and perhaps during instantiation of function templates
1097 // that contain lambda expressions that need to be transformed BUT not
1098 // necessarily during instantiation of a nested generic lambda's function call
1099 // operator (which might even be instantiated at the end of the TU) - at which
1100 // time the DeclContext tree is mature enough to query capture information
1101 // reliably - we use a two pronged approach to walk through all the lexically
1102 // enclosing lambda expressions:
1103 //
1104 // 1) Climb down the FunctionScopeInfo stack as long as each item represents
1105 // a Lambda (i.e. LambdaScopeInfo) AND each LSI's 'closure-type' is lexically
1106 // enclosed by the call-operator of the LSI below it on the stack (while
1107 // tracking the enclosing DC for step 2 if needed). Note the topmost LSI on
1108 // the stack represents the innermost lambda.
1109 //
1110 // 2) If we run out of enclosing LSI's, check if the enclosing DeclContext
1111 // represents a lambda's call operator. If it does, we must be instantiating
1112 // a generic lambda's call operator (represented by the Current LSI, and
1113 // should be the only scenario where an inconsistency between the LSI and the
1114 // DeclContext should occur), so climb out the DeclContexts if they
1115 // represent lambdas, while querying the corresponding closure types
1116 // regarding capture information.
1117
1118 // 1) Climb down the function scope info stack.
1119 for (int I = FunctionScopes.size();
1120 I-- && isa<LambdaScopeInfo>(FunctionScopes[I]) &&
1121 (!CurLSI || !CurLSI->Lambda || CurLSI->Lambda->getDeclContext() ==
1122 cast<LambdaScopeInfo>(FunctionScopes[I])->CallOperator);
1123 CurDC = getLambdaAwareParentOfDeclContext(CurDC)) {
1124 CurLSI = cast<LambdaScopeInfo>(FunctionScopes[I]);
1125
1126 if (!CurLSI->isCXXThisCaptured())
1127 continue;
1128
1129 auto C = CurLSI->getCXXThisCapture();
1130
1131 if (C.isCopyCapture()) {
1132 ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
1133 if (CurLSI->CallOperator->isConst())
1134 ClassType.addConst();
1135 return ASTCtx.getPointerType(ClassType);
1136 }
1137 }
1138
1139 // 2) We've run out of ScopeInfos but check 1. if CurDC is a lambda (which
1140 // can happen during instantiation of its nested generic lambda call
1141 // operator); 2. if we're in a lambda scope (lambda body).
1142 if (CurLSI && isLambdaCallOperator(CurDC)) {
1143 assert(isGenericLambdaCallOperatorSpecialization(CurLSI->CallOperator) &&
1144 "While computing 'this' capture-type for a generic lambda, when we "
1145 "run out of enclosing LSI's, yet the enclosing DC is a "
1146 "lambda-call-operator we must be (i.e. Current LSI) in a generic "
1147 "lambda call oeprator");
1148 assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator));
1149
1150 auto IsThisCaptured =
1151 [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) {
1152 IsConst = false;
1153 IsByCopy = false;
1154 for (auto &&C : Closure->captures()) {
1155 if (C.capturesThis()) {
1156 if (C.getCaptureKind() == LCK_StarThis)
1157 IsByCopy = true;
1158 if (Closure->getLambdaCallOperator()->isConst())
1159 IsConst = true;
1160 return true;
1161 }
1162 }
1163 return false;
1164 };
1165
1166 bool IsByCopyCapture = false;
1167 bool IsConstCapture = false;
1168 CXXRecordDecl *Closure = cast<CXXRecordDecl>(CurDC->getParent());
1169 while (Closure &&
1170 IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) {
1171 if (IsByCopyCapture) {
1172 ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
1173 if (IsConstCapture)
1174 ClassType.addConst();
1175 return ASTCtx.getPointerType(ClassType);
1176 }
1177 Closure = isLambdaCallOperator(Closure->getParent())
1178 ? cast<CXXRecordDecl>(Closure->getParent()->getParent())
1179 : nullptr;
1180 }
1181 }
1182 return ASTCtx.getPointerType(ClassType);
1183 }
1184
getCurrentThisType()1185 QualType Sema::getCurrentThisType() {
1186 DeclContext *DC = getFunctionLevelDeclContext();
1187 QualType ThisTy = CXXThisTypeOverride;
1188
1189 if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
1190 if (method && method->isInstance())
1191 ThisTy = method->getThisType();
1192 }
1193
1194 if (ThisTy.isNull() && isLambdaCallOperator(CurContext) &&
1195 inTemplateInstantiation() && isa<CXXRecordDecl>(DC)) {
1196
1197 // This is a lambda call operator that is being instantiated as a default
1198 // initializer. DC must point to the enclosing class type, so we can recover
1199 // the 'this' type from it.
1200 QualType ClassTy = Context.getTypeDeclType(cast<CXXRecordDecl>(DC));
1201 // There are no cv-qualifiers for 'this' within default initializers,
1202 // per [expr.prim.general]p4.
1203 ThisTy = Context.getPointerType(ClassTy);
1204 }
1205
1206 // If we are within a lambda's call operator, the cv-qualifiers of 'this'
1207 // might need to be adjusted if the lambda or any of its enclosing lambda's
1208 // captures '*this' by copy.
1209 if (!ThisTy.isNull() && isLambdaCallOperator(CurContext))
1210 return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy,
1211 CurContext, Context);
1212 return ThisTy;
1213 }
1214
CXXThisScopeRAII(Sema & S,Decl * ContextDecl,Qualifiers CXXThisTypeQuals,bool Enabled)1215 Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S,
1216 Decl *ContextDecl,
1217 Qualifiers CXXThisTypeQuals,
1218 bool Enabled)
1219 : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
1220 {
1221 if (!Enabled || !ContextDecl)
1222 return;
1223
1224 CXXRecordDecl *Record = nullptr;
1225 if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
1226 Record = Template->getTemplatedDecl();
1227 else
1228 Record = cast<CXXRecordDecl>(ContextDecl);
1229
1230 QualType T = S.Context.getRecordType(Record);
1231 T = S.getASTContext().getQualifiedType(T, CXXThisTypeQuals);
1232
1233 S.CXXThisTypeOverride = S.Context.getPointerType(T);
1234
1235 this->Enabled = true;
1236 }
1237
1238
~CXXThisScopeRAII()1239 Sema::CXXThisScopeRAII::~CXXThisScopeRAII() {
1240 if (Enabled) {
1241 S.CXXThisTypeOverride = OldCXXThisTypeOverride;
1242 }
1243 }
1244
buildLambdaThisCaptureFixit(Sema & Sema,LambdaScopeInfo * LSI)1245 static void buildLambdaThisCaptureFixit(Sema &Sema, LambdaScopeInfo *LSI) {
1246 SourceLocation DiagLoc = LSI->IntroducerRange.getEnd();
1247 assert(!LSI->isCXXThisCaptured());
1248 // [=, this] {}; // until C++20: Error: this when = is the default
1249 if (LSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval &&
1250 !Sema.getLangOpts().CPlusPlus20)
1251 return;
1252 Sema.Diag(DiagLoc, diag::note_lambda_this_capture_fixit)
1253 << FixItHint::CreateInsertion(
1254 DiagLoc, LSI->NumExplicitCaptures > 0 ? ", this" : "this");
1255 }
1256
CheckCXXThisCapture(SourceLocation Loc,const bool Explicit,bool BuildAndDiagnose,const unsigned * const FunctionScopeIndexToStopAt,const bool ByCopy)1257 bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
1258 bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
1259 const bool ByCopy) {
1260 // We don't need to capture this in an unevaluated context.
1261 if (isUnevaluatedContext() && !Explicit)
1262 return true;
1263
1264 assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value");
1265
1266 const int MaxFunctionScopesIndex = FunctionScopeIndexToStopAt
1267 ? *FunctionScopeIndexToStopAt
1268 : FunctionScopes.size() - 1;
1269
1270 // Check that we can capture the *enclosing object* (referred to by '*this')
1271 // by the capturing-entity/closure (lambda/block/etc) at
1272 // MaxFunctionScopesIndex-deep on the FunctionScopes stack.
1273
1274 // Note: The *enclosing object* can only be captured by-value by a
1275 // closure that is a lambda, using the explicit notation:
1276 // [*this] { ... }.
1277 // Every other capture of the *enclosing object* results in its by-reference
1278 // capture.
1279
1280 // For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes
1281 // stack), we can capture the *enclosing object* only if:
1282 // - 'L' has an explicit byref or byval capture of the *enclosing object*
1283 // - or, 'L' has an implicit capture.
1284 // AND
1285 // -- there is no enclosing closure
1286 // -- or, there is some enclosing closure 'E' that has already captured the
1287 // *enclosing object*, and every intervening closure (if any) between 'E'
1288 // and 'L' can implicitly capture the *enclosing object*.
1289 // -- or, every enclosing closure can implicitly capture the
1290 // *enclosing object*
1291
1292
1293 unsigned NumCapturingClosures = 0;
1294 for (int idx = MaxFunctionScopesIndex; idx >= 0; idx--) {
1295 if (CapturingScopeInfo *CSI =
1296 dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
1297 if (CSI->CXXThisCaptureIndex != 0) {
1298 // 'this' is already being captured; there isn't anything more to do.
1299 CSI->Captures[CSI->CXXThisCaptureIndex - 1].markUsed(BuildAndDiagnose);
1300 break;
1301 }
1302 LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
1303 if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) {
1304 // This context can't implicitly capture 'this'; fail out.
1305 if (BuildAndDiagnose) {
1306 Diag(Loc, diag::err_this_capture)
1307 << (Explicit && idx == MaxFunctionScopesIndex);
1308 if (!Explicit)
1309 buildLambdaThisCaptureFixit(*this, LSI);
1310 }
1311 return true;
1312 }
1313 if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
1314 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||
1315 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||
1316 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||
1317 (Explicit && idx == MaxFunctionScopesIndex)) {
1318 // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first
1319 // iteration through can be an explicit capture, all enclosing closures,
1320 // if any, must perform implicit captures.
1321
1322 // This closure can capture 'this'; continue looking upwards.
1323 NumCapturingClosures++;
1324 continue;
1325 }
1326 // This context can't implicitly capture 'this'; fail out.
1327 if (BuildAndDiagnose)
1328 Diag(Loc, diag::err_this_capture)
1329 << (Explicit && idx == MaxFunctionScopesIndex);
1330
1331 if (!Explicit)
1332 buildLambdaThisCaptureFixit(*this, LSI);
1333 return true;
1334 }
1335 break;
1336 }
1337 if (!BuildAndDiagnose) return false;
1338
1339 // If we got here, then the closure at MaxFunctionScopesIndex on the
1340 // FunctionScopes stack, can capture the *enclosing object*, so capture it
1341 // (including implicit by-reference captures in any enclosing closures).
1342
1343 // In the loop below, respect the ByCopy flag only for the closure requesting
1344 // the capture (i.e. first iteration through the loop below). Ignore it for
1345 // all enclosing closure's up to NumCapturingClosures (since they must be
1346 // implicitly capturing the *enclosing object* by reference (see loop
1347 // above)).
1348 assert((!ByCopy ||
1349 dyn_cast<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) &&
1350 "Only a lambda can capture the enclosing object (referred to by "
1351 "*this) by copy");
1352 QualType ThisTy = getCurrentThisType();
1353 for (int idx = MaxFunctionScopesIndex; NumCapturingClosures;
1354 --idx, --NumCapturingClosures) {
1355 CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
1356
1357 // The type of the corresponding data member (not a 'this' pointer if 'by
1358 // copy').
1359 QualType CaptureType = ThisTy;
1360 if (ByCopy) {
1361 // If we are capturing the object referred to by '*this' by copy, ignore
1362 // any cv qualifiers inherited from the type of the member function for
1363 // the type of the closure-type's corresponding data member and any use
1364 // of 'this'.
1365 CaptureType = ThisTy->getPointeeType();
1366 CaptureType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
1367 }
1368
1369 bool isNested = NumCapturingClosures > 1;
1370 CSI->addThisCapture(isNested, Loc, CaptureType, ByCopy);
1371 }
1372 return false;
1373 }
1374
ActOnCXXThis(SourceLocation Loc)1375 ExprResult Sema::ActOnCXXThis(SourceLocation Loc) {
1376 /// C++ 9.3.2: In the body of a non-static member function, the keyword this
1377 /// is a non-lvalue expression whose value is the address of the object for
1378 /// which the function is called.
1379
1380 QualType ThisTy = getCurrentThisType();
1381 if (ThisTy.isNull())
1382 return Diag(Loc, diag::err_invalid_this_use);
1383 return BuildCXXThisExpr(Loc, ThisTy, /*IsImplicit=*/false);
1384 }
1385
BuildCXXThisExpr(SourceLocation Loc,QualType Type,bool IsImplicit)1386 Expr *Sema::BuildCXXThisExpr(SourceLocation Loc, QualType Type,
1387 bool IsImplicit) {
1388 auto *This = new (Context) CXXThisExpr(Loc, Type, IsImplicit);
1389 MarkThisReferenced(This);
1390 return This;
1391 }
1392
MarkThisReferenced(CXXThisExpr * This)1393 void Sema::MarkThisReferenced(CXXThisExpr *This) {
1394 CheckCXXThisCapture(This->getExprLoc());
1395 }
1396
isThisOutsideMemberFunctionBody(QualType BaseType)1397 bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) {
1398 // If we're outside the body of a member function, then we'll have a specified
1399 // type for 'this'.
1400 if (CXXThisTypeOverride.isNull())
1401 return false;
1402
1403 // Determine whether we're looking into a class that's currently being
1404 // defined.
1405 CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl();
1406 return Class && Class->isBeingDefined();
1407 }
1408
1409 /// Parse construction of a specified type.
1410 /// Can be interpreted either as function-style casting ("int(x)")
1411 /// or class type construction ("ClassType(x,y,z)")
1412 /// or creation of a value-initialized type ("int()").
1413 ExprResult
ActOnCXXTypeConstructExpr(ParsedType TypeRep,SourceLocation LParenOrBraceLoc,MultiExprArg exprs,SourceLocation RParenOrBraceLoc,bool ListInitialization)1414 Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep,
1415 SourceLocation LParenOrBraceLoc,
1416 MultiExprArg exprs,
1417 SourceLocation RParenOrBraceLoc,
1418 bool ListInitialization) {
1419 if (!TypeRep)
1420 return ExprError();
1421
1422 TypeSourceInfo *TInfo;
1423 QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
1424 if (!TInfo)
1425 TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation());
1426
1427 auto Result = BuildCXXTypeConstructExpr(TInfo, LParenOrBraceLoc, exprs,
1428 RParenOrBraceLoc, ListInitialization);
1429 // Avoid creating a non-type-dependent expression that contains typos.
1430 // Non-type-dependent expressions are liable to be discarded without
1431 // checking for embedded typos.
1432 if (!Result.isInvalid() && Result.get()->isInstantiationDependent() &&
1433 !Result.get()->isTypeDependent())
1434 Result = CorrectDelayedTyposInExpr(Result.get());
1435 else if (Result.isInvalid())
1436 Result = CreateRecoveryExpr(TInfo->getTypeLoc().getBeginLoc(),
1437 RParenOrBraceLoc, exprs, Ty);
1438 return Result;
1439 }
1440
1441 ExprResult
BuildCXXTypeConstructExpr(TypeSourceInfo * TInfo,SourceLocation LParenOrBraceLoc,MultiExprArg Exprs,SourceLocation RParenOrBraceLoc,bool ListInitialization)1442 Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo,
1443 SourceLocation LParenOrBraceLoc,
1444 MultiExprArg Exprs,
1445 SourceLocation RParenOrBraceLoc,
1446 bool ListInitialization) {
1447 QualType Ty = TInfo->getType();
1448 SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();
1449
1450 assert((!ListInitialization ||
1451 (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) &&
1452 "List initialization must have initializer list as expression.");
1453 SourceRange FullRange = SourceRange(TyBeginLoc, RParenOrBraceLoc);
1454
1455 InitializedEntity Entity =
1456 InitializedEntity::InitializeTemporary(Context, TInfo);
1457 InitializationKind Kind =
1458 Exprs.size()
1459 ? ListInitialization
1460 ? InitializationKind::CreateDirectList(
1461 TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc)
1462 : InitializationKind::CreateDirect(TyBeginLoc, LParenOrBraceLoc,
1463 RParenOrBraceLoc)
1464 : InitializationKind::CreateValue(TyBeginLoc, LParenOrBraceLoc,
1465 RParenOrBraceLoc);
1466
1467 // C++1z [expr.type.conv]p1:
1468 // If the type is a placeholder for a deduced class type, [...perform class
1469 // template argument deduction...]
1470 DeducedType *Deduced = Ty->getContainedDeducedType();
1471 if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
1472 Ty = DeduceTemplateSpecializationFromInitializer(TInfo, Entity,
1473 Kind, Exprs);
1474 if (Ty.isNull())
1475 return ExprError();
1476 Entity = InitializedEntity::InitializeTemporary(TInfo, Ty);
1477 }
1478
1479 if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) {
1480 // FIXME: CXXUnresolvedConstructExpr does not model list-initialization
1481 // directly. We work around this by dropping the locations of the braces.
1482 SourceRange Locs = ListInitialization
1483 ? SourceRange()
1484 : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
1485 return CXXUnresolvedConstructExpr::Create(Context, Ty.getNonReferenceType(),
1486 TInfo, Locs.getBegin(), Exprs,
1487 Locs.getEnd());
1488 }
1489
1490 // C++ [expr.type.conv]p1:
1491 // If the expression list is a parenthesized single expression, the type
1492 // conversion expression is equivalent (in definedness, and if defined in
1493 // meaning) to the corresponding cast expression.
1494 if (Exprs.size() == 1 && !ListInitialization &&
1495 !isa<InitListExpr>(Exprs[0])) {
1496 Expr *Arg = Exprs[0];
1497 return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenOrBraceLoc, Arg,
1498 RParenOrBraceLoc);
1499 }
1500
1501 // For an expression of the form T(), T shall not be an array type.
1502 QualType ElemTy = Ty;
1503 if (Ty->isArrayType()) {
1504 if (!ListInitialization)
1505 return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type)
1506 << FullRange);
1507 ElemTy = Context.getBaseElementType(Ty);
1508 }
1509
1510 // There doesn't seem to be an explicit rule against this but sanity demands
1511 // we only construct objects with object types.
1512 if (Ty->isFunctionType())
1513 return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type)
1514 << Ty << FullRange);
1515
1516 // C++17 [expr.type.conv]p2:
1517 // If the type is cv void and the initializer is (), the expression is a
1518 // prvalue of the specified type that performs no initialization.
1519 if (!Ty->isVoidType() &&
1520 RequireCompleteType(TyBeginLoc, ElemTy,
1521 diag::err_invalid_incomplete_type_use, FullRange))
1522 return ExprError();
1523
1524 // Otherwise, the expression is a prvalue of the specified type whose
1525 // result object is direct-initialized (11.6) with the initializer.
1526 InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
1527 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);
1528
1529 if (Result.isInvalid())
1530 return Result;
1531
1532 Expr *Inner = Result.get();
1533 if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
1534 Inner = BTE->getSubExpr();
1535 if (!isa<CXXTemporaryObjectExpr>(Inner) &&
1536 !isa<CXXScalarValueInitExpr>(Inner)) {
1537 // If we created a CXXTemporaryObjectExpr, that node also represents the
1538 // functional cast. Otherwise, create an explicit cast to represent
1539 // the syntactic form of a functional-style cast that was used here.
1540 //
1541 // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr
1542 // would give a more consistent AST representation than using a
1543 // CXXTemporaryObjectExpr. It's also weird that the functional cast
1544 // is sometimes handled by initialization and sometimes not.
1545 QualType ResultType = Result.get()->getType();
1546 SourceRange Locs = ListInitialization
1547 ? SourceRange()
1548 : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
1549 Result = CXXFunctionalCastExpr::Create(
1550 Context, ResultType, Expr::getValueKindForType(Ty), TInfo, CK_NoOp,
1551 Result.get(), /*Path=*/nullptr, CurFPFeatureOverrides(),
1552 Locs.getBegin(), Locs.getEnd());
1553 }
1554
1555 return Result;
1556 }
1557
isUsualDeallocationFunction(const CXXMethodDecl * Method)1558 bool Sema::isUsualDeallocationFunction(const CXXMethodDecl *Method) {
1559 // [CUDA] Ignore this function, if we can't call it.
1560 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext);
1561 if (getLangOpts().CUDA) {
1562 auto CallPreference = IdentifyCUDAPreference(Caller, Method);
1563 // If it's not callable at all, it's not the right function.
1564 if (CallPreference < CFP_WrongSide)
1565 return false;
1566 if (CallPreference == CFP_WrongSide) {
1567 // Maybe. We have to check if there are better alternatives.
1568 DeclContext::lookup_result R =
1569 Method->getDeclContext()->lookup(Method->getDeclName());
1570 for (const auto *D : R) {
1571 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
1572 if (IdentifyCUDAPreference(Caller, FD) > CFP_WrongSide)
1573 return false;
1574 }
1575 }
1576 // We've found no better variants.
1577 }
1578 }
1579
1580 SmallVector<const FunctionDecl*, 4> PreventedBy;
1581 bool Result = Method->isUsualDeallocationFunction(PreventedBy);
1582
1583 if (Result || !getLangOpts().CUDA || PreventedBy.empty())
1584 return Result;
1585
1586 // In case of CUDA, return true if none of the 1-argument deallocator
1587 // functions are actually callable.
1588 return llvm::none_of(PreventedBy, [&](const FunctionDecl *FD) {
1589 assert(FD->getNumParams() == 1 &&
1590 "Only single-operand functions should be in PreventedBy");
1591 return IdentifyCUDAPreference(Caller, FD) >= CFP_HostDevice;
1592 });
1593 }
1594
1595 /// Determine whether the given function is a non-placement
1596 /// deallocation function.
isNonPlacementDeallocationFunction(Sema & S,FunctionDecl * FD)1597 static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) {
1598 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
1599 return S.isUsualDeallocationFunction(Method);
1600
1601 if (FD->getOverloadedOperator() != OO_Delete &&
1602 FD->getOverloadedOperator() != OO_Array_Delete)
1603 return false;
1604
1605 unsigned UsualParams = 1;
1606
1607 if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() &&
1608 S.Context.hasSameUnqualifiedType(
1609 FD->getParamDecl(UsualParams)->getType(),
1610 S.Context.getSizeType()))
1611 ++UsualParams;
1612
1613 if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() &&
1614 S.Context.hasSameUnqualifiedType(
1615 FD->getParamDecl(UsualParams)->getType(),
1616 S.Context.getTypeDeclType(S.getStdAlignValT())))
1617 ++UsualParams;
1618
1619 return UsualParams == FD->getNumParams();
1620 }
1621
1622 namespace {
1623 struct UsualDeallocFnInfo {
UsualDeallocFnInfo__anond7c070200a11::UsualDeallocFnInfo1624 UsualDeallocFnInfo() : Found(), FD(nullptr) {}
UsualDeallocFnInfo__anond7c070200a11::UsualDeallocFnInfo1625 UsualDeallocFnInfo(Sema &S, DeclAccessPair Found)
1626 : Found(Found), FD(dyn_cast<FunctionDecl>(Found->getUnderlyingDecl())),
1627 Destroying(false), HasSizeT(false), HasAlignValT(false),
1628 CUDAPref(Sema::CFP_Native) {
1629 // A function template declaration is never a usual deallocation function.
1630 if (!FD)
1631 return;
1632 unsigned NumBaseParams = 1;
1633 if (FD->isDestroyingOperatorDelete()) {
1634 Destroying = true;
1635 ++NumBaseParams;
1636 }
1637
1638 if (NumBaseParams < FD->getNumParams() &&
1639 S.Context.hasSameUnqualifiedType(
1640 FD->getParamDecl(NumBaseParams)->getType(),
1641 S.Context.getSizeType())) {
1642 ++NumBaseParams;
1643 HasSizeT = true;
1644 }
1645
1646 if (NumBaseParams < FD->getNumParams() &&
1647 FD->getParamDecl(NumBaseParams)->getType()->isAlignValT()) {
1648 ++NumBaseParams;
1649 HasAlignValT = true;
1650 }
1651
1652 // In CUDA, determine how much we'd like / dislike to call this.
1653 if (S.getLangOpts().CUDA)
1654 if (auto *Caller = dyn_cast<FunctionDecl>(S.CurContext))
1655 CUDAPref = S.IdentifyCUDAPreference(Caller, FD);
1656 }
1657
operator bool__anond7c070200a11::UsualDeallocFnInfo1658 explicit operator bool() const { return FD; }
1659
isBetterThan__anond7c070200a11::UsualDeallocFnInfo1660 bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize,
1661 bool WantAlign) const {
1662 // C++ P0722:
1663 // A destroying operator delete is preferred over a non-destroying
1664 // operator delete.
1665 if (Destroying != Other.Destroying)
1666 return Destroying;
1667
1668 // C++17 [expr.delete]p10:
1669 // If the type has new-extended alignment, a function with a parameter
1670 // of type std::align_val_t is preferred; otherwise a function without
1671 // such a parameter is preferred
1672 if (HasAlignValT != Other.HasAlignValT)
1673 return HasAlignValT == WantAlign;
1674
1675 if (HasSizeT != Other.HasSizeT)
1676 return HasSizeT == WantSize;
1677
1678 // Use CUDA call preference as a tiebreaker.
1679 return CUDAPref > Other.CUDAPref;
1680 }
1681
1682 DeclAccessPair Found;
1683 FunctionDecl *FD;
1684 bool Destroying, HasSizeT, HasAlignValT;
1685 Sema::CUDAFunctionPreference CUDAPref;
1686 };
1687 }
1688
1689 /// Determine whether a type has new-extended alignment. This may be called when
1690 /// the type is incomplete (for a delete-expression with an incomplete pointee
1691 /// type), in which case it will conservatively return false if the alignment is
1692 /// not known.
hasNewExtendedAlignment(Sema & S,QualType AllocType)1693 static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) {
1694 return S.getLangOpts().AlignedAllocation &&
1695 S.getASTContext().getTypeAlignIfKnown(AllocType) >
1696 S.getASTContext().getTargetInfo().getNewAlign();
1697 }
1698
1699 /// Select the correct "usual" deallocation function to use from a selection of
1700 /// deallocation functions (either global or class-scope).
resolveDeallocationOverload(Sema & S,LookupResult & R,bool WantSize,bool WantAlign,llvm::SmallVectorImpl<UsualDeallocFnInfo> * BestFns=nullptr)1701 static UsualDeallocFnInfo resolveDeallocationOverload(
1702 Sema &S, LookupResult &R, bool WantSize, bool WantAlign,
1703 llvm::SmallVectorImpl<UsualDeallocFnInfo> *BestFns = nullptr) {
1704 UsualDeallocFnInfo Best;
1705
1706 for (auto I = R.begin(), E = R.end(); I != E; ++I) {
1707 UsualDeallocFnInfo Info(S, I.getPair());
1708 if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) ||
1709 Info.CUDAPref == Sema::CFP_Never)
1710 continue;
1711
1712 if (!Best) {
1713 Best = Info;
1714 if (BestFns)
1715 BestFns->push_back(Info);
1716 continue;
1717 }
1718
1719 if (Best.isBetterThan(Info, WantSize, WantAlign))
1720 continue;
1721
1722 // If more than one preferred function is found, all non-preferred
1723 // functions are eliminated from further consideration.
1724 if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign))
1725 BestFns->clear();
1726
1727 Best = Info;
1728 if (BestFns)
1729 BestFns->push_back(Info);
1730 }
1731
1732 return Best;
1733 }
1734
1735 /// Determine whether a given type is a class for which 'delete[]' would call
1736 /// a member 'operator delete[]' with a 'size_t' parameter. This implies that
1737 /// we need to store the array size (even if the type is
1738 /// trivially-destructible).
doesUsualArrayDeleteWantSize(Sema & S,SourceLocation loc,QualType allocType)1739 static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc,
1740 QualType allocType) {
1741 const RecordType *record =
1742 allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
1743 if (!record) return false;
1744
1745 // Try to find an operator delete[] in class scope.
1746
1747 DeclarationName deleteName =
1748 S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
1749 LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
1750 S.LookupQualifiedName(ops, record->getDecl());
1751
1752 // We're just doing this for information.
1753 ops.suppressDiagnostics();
1754
1755 // Very likely: there's no operator delete[].
1756 if (ops.empty()) return false;
1757
1758 // If it's ambiguous, it should be illegal to call operator delete[]
1759 // on this thing, so it doesn't matter if we allocate extra space or not.
1760 if (ops.isAmbiguous()) return false;
1761
1762 // C++17 [expr.delete]p10:
1763 // If the deallocation functions have class scope, the one without a
1764 // parameter of type std::size_t is selected.
1765 auto Best = resolveDeallocationOverload(
1766 S, ops, /*WantSize*/false,
1767 /*WantAlign*/hasNewExtendedAlignment(S, allocType));
1768 return Best && Best.HasSizeT;
1769 }
1770
1771 /// Parsed a C++ 'new' expression (C++ 5.3.4).
1772 ///
1773 /// E.g.:
1774 /// @code new (memory) int[size][4] @endcode
1775 /// or
1776 /// @code ::new Foo(23, "hello") @endcode
1777 ///
1778 /// \param StartLoc The first location of the expression.
1779 /// \param UseGlobal True if 'new' was prefixed with '::'.
1780 /// \param PlacementLParen Opening paren of the placement arguments.
1781 /// \param PlacementArgs Placement new arguments.
1782 /// \param PlacementRParen Closing paren of the placement arguments.
1783 /// \param TypeIdParens If the type is in parens, the source range.
1784 /// \param D The type to be allocated, as well as array dimensions.
1785 /// \param Initializer The initializing expression or initializer-list, or null
1786 /// if there is none.
1787 ExprResult
ActOnCXXNew(SourceLocation StartLoc,bool UseGlobal,SourceLocation PlacementLParen,MultiExprArg PlacementArgs,SourceLocation PlacementRParen,SourceRange TypeIdParens,Declarator & D,Expr * Initializer)1788 Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
1789 SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
1790 SourceLocation PlacementRParen, SourceRange TypeIdParens,
1791 Declarator &D, Expr *Initializer) {
1792 Optional<Expr *> ArraySize;
1793 // If the specified type is an array, unwrap it and save the expression.
1794 if (D.getNumTypeObjects() > 0 &&
1795 D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
1796 DeclaratorChunk &Chunk = D.getTypeObject(0);
1797 if (D.getDeclSpec().hasAutoTypeSpec())
1798 return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
1799 << D.getSourceRange());
1800 if (Chunk.Arr.hasStatic)
1801 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
1802 << D.getSourceRange());
1803 if (!Chunk.Arr.NumElts && !Initializer)
1804 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
1805 << D.getSourceRange());
1806
1807 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
1808 D.DropFirstTypeObject();
1809 }
1810
1811 // Every dimension shall be of constant size.
1812 if (ArraySize) {
1813 for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
1814 if (D.getTypeObject(I).Kind != DeclaratorChunk::Array)
1815 break;
1816
1817 DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr;
1818 if (Expr *NumElts = (Expr *)Array.NumElts) {
1819 if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
1820 // FIXME: GCC permits constant folding here. We should either do so consistently
1821 // or not do so at all, rather than changing behavior in C++14 onwards.
1822 if (getLangOpts().CPlusPlus14) {
1823 // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
1824 // shall be a converted constant expression (5.19) of type std::size_t
1825 // and shall evaluate to a strictly positive value.
1826 llvm::APSInt Value(Context.getIntWidth(Context.getSizeType()));
1827 Array.NumElts
1828 = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value,
1829 CCEK_ArrayBound)
1830 .get();
1831 } else {
1832 Array.NumElts =
1833 VerifyIntegerConstantExpression(
1834 NumElts, nullptr, diag::err_new_array_nonconst, AllowFold)
1835 .get();
1836 }
1837 if (!Array.NumElts)
1838 return ExprError();
1839 }
1840 }
1841 }
1842 }
1843
1844 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
1845 QualType AllocType = TInfo->getType();
1846 if (D.isInvalidType())
1847 return ExprError();
1848
1849 SourceRange DirectInitRange;
1850 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
1851 DirectInitRange = List->getSourceRange();
1852
1853 return BuildCXXNew(SourceRange(StartLoc, D.getEndLoc()), UseGlobal,
1854 PlacementLParen, PlacementArgs, PlacementRParen,
1855 TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange,
1856 Initializer);
1857 }
1858
isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style,Expr * Init)1859 static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style,
1860 Expr *Init) {
1861 if (!Init)
1862 return true;
1863 if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
1864 return PLE->getNumExprs() == 0;
1865 if (isa<ImplicitValueInitExpr>(Init))
1866 return true;
1867 else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
1868 return !CCE->isListInitialization() &&
1869 CCE->getConstructor()->isDefaultConstructor();
1870 else if (Style == CXXNewExpr::ListInit) {
1871 assert(isa<InitListExpr>(Init) &&
1872 "Shouldn't create list CXXConstructExprs for arrays.");
1873 return true;
1874 }
1875 return false;
1876 }
1877
1878 bool
isUnavailableAlignedAllocationFunction(const FunctionDecl & FD) const1879 Sema::isUnavailableAlignedAllocationFunction(const FunctionDecl &FD) const {
1880 if (!getLangOpts().AlignedAllocationUnavailable)
1881 return false;
1882 if (FD.isDefined())
1883 return false;
1884 Optional<unsigned> AlignmentParam;
1885 if (FD.isReplaceableGlobalAllocationFunction(&AlignmentParam) &&
1886 AlignmentParam.hasValue())
1887 return true;
1888 return false;
1889 }
1890
1891 // Emit a diagnostic if an aligned allocation/deallocation function that is not
1892 // implemented in the standard library is selected.
diagnoseUnavailableAlignedAllocation(const FunctionDecl & FD,SourceLocation Loc)1893 void Sema::diagnoseUnavailableAlignedAllocation(const FunctionDecl &FD,
1894 SourceLocation Loc) {
1895 if (isUnavailableAlignedAllocationFunction(FD)) {
1896 const llvm::Triple &T = getASTContext().getTargetInfo().getTriple();
1897 StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling(
1898 getASTContext().getTargetInfo().getPlatformName());
1899 VersionTuple OSVersion = alignedAllocMinVersion(T.getOS());
1900
1901 OverloadedOperatorKind Kind = FD.getDeclName().getCXXOverloadedOperator();
1902 bool IsDelete = Kind == OO_Delete || Kind == OO_Array_Delete;
1903 Diag(Loc, diag::err_aligned_allocation_unavailable)
1904 << IsDelete << FD.getType().getAsString() << OSName
1905 << OSVersion.getAsString() << OSVersion.empty();
1906 Diag(Loc, diag::note_silence_aligned_allocation_unavailable);
1907 }
1908 }
1909
1910 ExprResult
BuildCXXNew(SourceRange Range,bool UseGlobal,SourceLocation PlacementLParen,MultiExprArg PlacementArgs,SourceLocation PlacementRParen,SourceRange TypeIdParens,QualType AllocType,TypeSourceInfo * AllocTypeInfo,Optional<Expr * > ArraySize,SourceRange DirectInitRange,Expr * Initializer)1911 Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
1912 SourceLocation PlacementLParen,
1913 MultiExprArg PlacementArgs,
1914 SourceLocation PlacementRParen,
1915 SourceRange TypeIdParens,
1916 QualType AllocType,
1917 TypeSourceInfo *AllocTypeInfo,
1918 Optional<Expr *> ArraySize,
1919 SourceRange DirectInitRange,
1920 Expr *Initializer) {
1921 SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
1922 SourceLocation StartLoc = Range.getBegin();
1923
1924 CXXNewExpr::InitializationStyle initStyle;
1925 if (DirectInitRange.isValid()) {
1926 assert(Initializer && "Have parens but no initializer.");
1927 initStyle = CXXNewExpr::CallInit;
1928 } else if (Initializer && isa<InitListExpr>(Initializer))
1929 initStyle = CXXNewExpr::ListInit;
1930 else {
1931 assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||
1932 isa<CXXConstructExpr>(Initializer)) &&
1933 "Initializer expression that cannot have been implicitly created.");
1934 initStyle = CXXNewExpr::NoInit;
1935 }
1936
1937 Expr **Inits = &Initializer;
1938 unsigned NumInits = Initializer ? 1 : 0;
1939 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
1940 assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init");
1941 Inits = List->getExprs();
1942 NumInits = List->getNumExprs();
1943 }
1944
1945 // C++11 [expr.new]p15:
1946 // A new-expression that creates an object of type T initializes that
1947 // object as follows:
1948 InitializationKind Kind
1949 // - If the new-initializer is omitted, the object is default-
1950 // initialized (8.5); if no initialization is performed,
1951 // the object has indeterminate value
1952 = initStyle == CXXNewExpr::NoInit
1953 ? InitializationKind::CreateDefault(TypeRange.getBegin())
1954 // - Otherwise, the new-initializer is interpreted according to
1955 // the
1956 // initialization rules of 8.5 for direct-initialization.
1957 : initStyle == CXXNewExpr::ListInit
1958 ? InitializationKind::CreateDirectList(
1959 TypeRange.getBegin(), Initializer->getBeginLoc(),
1960 Initializer->getEndLoc())
1961 : InitializationKind::CreateDirect(TypeRange.getBegin(),
1962 DirectInitRange.getBegin(),
1963 DirectInitRange.getEnd());
1964
1965 // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
1966 auto *Deduced = AllocType->getContainedDeducedType();
1967 if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
1968 if (ArraySize)
1969 return ExprError(
1970 Diag(ArraySize ? (*ArraySize)->getExprLoc() : TypeRange.getBegin(),
1971 diag::err_deduced_class_template_compound_type)
1972 << /*array*/ 2
1973 << (ArraySize ? (*ArraySize)->getSourceRange() : TypeRange));
1974
1975 InitializedEntity Entity
1976 = InitializedEntity::InitializeNew(StartLoc, AllocType);
1977 AllocType = DeduceTemplateSpecializationFromInitializer(
1978 AllocTypeInfo, Entity, Kind, MultiExprArg(Inits, NumInits));
1979 if (AllocType.isNull())
1980 return ExprError();
1981 } else if (Deduced) {
1982 bool Braced = (initStyle == CXXNewExpr::ListInit);
1983 if (NumInits == 1) {
1984 if (auto p = dyn_cast_or_null<InitListExpr>(Inits[0])) {
1985 Inits = p->getInits();
1986 NumInits = p->getNumInits();
1987 Braced = true;
1988 }
1989 }
1990
1991 if (initStyle == CXXNewExpr::NoInit || NumInits == 0)
1992 return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
1993 << AllocType << TypeRange);
1994 if (NumInits > 1) {
1995 Expr *FirstBad = Inits[1];
1996 return ExprError(Diag(FirstBad->getBeginLoc(),
1997 diag::err_auto_new_ctor_multiple_expressions)
1998 << AllocType << TypeRange);
1999 }
2000 if (Braced && !getLangOpts().CPlusPlus17)
2001 Diag(Initializer->getBeginLoc(), diag::ext_auto_new_list_init)
2002 << AllocType << TypeRange;
2003 Expr *Deduce = Inits[0];
2004 QualType DeducedType;
2005 if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed)
2006 return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
2007 << AllocType << Deduce->getType()
2008 << TypeRange << Deduce->getSourceRange());
2009 if (DeducedType.isNull())
2010 return ExprError();
2011 AllocType = DeducedType;
2012 }
2013
2014 // Per C++0x [expr.new]p5, the type being constructed may be a
2015 // typedef of an array type.
2016 if (!ArraySize) {
2017 if (const ConstantArrayType *Array
2018 = Context.getAsConstantArrayType(AllocType)) {
2019 ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
2020 Context.getSizeType(),
2021 TypeRange.getEnd());
2022 AllocType = Array->getElementType();
2023 }
2024 }
2025
2026 if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
2027 return ExprError();
2028
2029 // In ARC, infer 'retaining' for the allocated
2030 if (getLangOpts().ObjCAutoRefCount &&
2031 AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
2032 AllocType->isObjCLifetimeType()) {
2033 AllocType = Context.getLifetimeQualifiedType(AllocType,
2034 AllocType->getObjCARCImplicitLifetime());
2035 }
2036
2037 QualType ResultType = Context.getPointerType(AllocType);
2038
2039 if (ArraySize && *ArraySize &&
2040 (*ArraySize)->getType()->isNonOverloadPlaceholderType()) {
2041 ExprResult result = CheckPlaceholderExpr(*ArraySize);
2042 if (result.isInvalid()) return ExprError();
2043 ArraySize = result.get();
2044 }
2045 // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
2046 // integral or enumeration type with a non-negative value."
2047 // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
2048 // enumeration type, or a class type for which a single non-explicit
2049 // conversion function to integral or unscoped enumeration type exists.
2050 // C++1y [expr.new]p6: The expression [...] is implicitly converted to
2051 // std::size_t.
2052 llvm::Optional<uint64_t> KnownArraySize;
2053 if (ArraySize && *ArraySize && !(*ArraySize)->isTypeDependent()) {
2054 ExprResult ConvertedSize;
2055 if (getLangOpts().CPlusPlus14) {
2056 assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?");
2057
2058 ConvertedSize = PerformImplicitConversion(*ArraySize, Context.getSizeType(),
2059 AA_Converting);
2060
2061 if (!ConvertedSize.isInvalid() &&
2062 (*ArraySize)->getType()->getAs<RecordType>())
2063 // Diagnose the compatibility of this conversion.
2064 Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
2065 << (*ArraySize)->getType() << 0 << "'size_t'";
2066 } else {
2067 class SizeConvertDiagnoser : public ICEConvertDiagnoser {
2068 protected:
2069 Expr *ArraySize;
2070
2071 public:
2072 SizeConvertDiagnoser(Expr *ArraySize)
2073 : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
2074 ArraySize(ArraySize) {}
2075
2076 SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
2077 QualType T) override {
2078 return S.Diag(Loc, diag::err_array_size_not_integral)
2079 << S.getLangOpts().CPlusPlus11 << T;
2080 }
2081
2082 SemaDiagnosticBuilder diagnoseIncomplete(
2083 Sema &S, SourceLocation Loc, QualType T) override {
2084 return S.Diag(Loc, diag::err_array_size_incomplete_type)
2085 << T << ArraySize->getSourceRange();
2086 }
2087
2088 SemaDiagnosticBuilder diagnoseExplicitConv(
2089 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
2090 return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
2091 }
2092
2093 SemaDiagnosticBuilder noteExplicitConv(
2094 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
2095 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
2096 << ConvTy->isEnumeralType() << ConvTy;
2097 }
2098
2099 SemaDiagnosticBuilder diagnoseAmbiguous(
2100 Sema &S, SourceLocation Loc, QualType T) override {
2101 return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
2102 }
2103
2104 SemaDiagnosticBuilder noteAmbiguous(
2105 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
2106 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
2107 << ConvTy->isEnumeralType() << ConvTy;
2108 }
2109
2110 SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
2111 QualType T,
2112 QualType ConvTy) override {
2113 return S.Diag(Loc,
2114 S.getLangOpts().CPlusPlus11
2115 ? diag::warn_cxx98_compat_array_size_conversion
2116 : diag::ext_array_size_conversion)
2117 << T << ConvTy->isEnumeralType() << ConvTy;
2118 }
2119 } SizeDiagnoser(*ArraySize);
2120
2121 ConvertedSize = PerformContextualImplicitConversion(StartLoc, *ArraySize,
2122 SizeDiagnoser);
2123 }
2124 if (ConvertedSize.isInvalid())
2125 return ExprError();
2126
2127 ArraySize = ConvertedSize.get();
2128 QualType SizeType = (*ArraySize)->getType();
2129
2130 if (!SizeType->isIntegralOrUnscopedEnumerationType())
2131 return ExprError();
2132
2133 // C++98 [expr.new]p7:
2134 // The expression in a direct-new-declarator shall have integral type
2135 // with a non-negative value.
2136 //
2137 // Let's see if this is a constant < 0. If so, we reject it out of hand,
2138 // per CWG1464. Otherwise, if it's not a constant, we must have an
2139 // unparenthesized array type.
2140 if (!(*ArraySize)->isValueDependent()) {
2141 // We've already performed any required implicit conversion to integer or
2142 // unscoped enumeration type.
2143 // FIXME: Per CWG1464, we are required to check the value prior to
2144 // converting to size_t. This will never find a negative array size in
2145 // C++14 onwards, because Value is always unsigned here!
2146 if (Optional<llvm::APSInt> Value =
2147 (*ArraySize)->getIntegerConstantExpr(Context)) {
2148 if (Value->isSigned() && Value->isNegative()) {
2149 return ExprError(Diag((*ArraySize)->getBeginLoc(),
2150 diag::err_typecheck_negative_array_size)
2151 << (*ArraySize)->getSourceRange());
2152 }
2153
2154 if (!AllocType->isDependentType()) {
2155 unsigned ActiveSizeBits = ConstantArrayType::getNumAddressingBits(
2156 Context, AllocType, *Value);
2157 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
2158 return ExprError(
2159 Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large)
2160 << toString(*Value, 10) << (*ArraySize)->getSourceRange());
2161 }
2162
2163 KnownArraySize = Value->getZExtValue();
2164 } else if (TypeIdParens.isValid()) {
2165 // Can't have dynamic array size when the type-id is in parentheses.
2166 Diag((*ArraySize)->getBeginLoc(), diag::ext_new_paren_array_nonconst)
2167 << (*ArraySize)->getSourceRange()
2168 << FixItHint::CreateRemoval(TypeIdParens.getBegin())
2169 << FixItHint::CreateRemoval(TypeIdParens.getEnd());
2170
2171 TypeIdParens = SourceRange();
2172 }
2173 }
2174
2175 // Note that we do *not* convert the argument in any way. It can
2176 // be signed, larger than size_t, whatever.
2177 }
2178
2179 FunctionDecl *OperatorNew = nullptr;
2180 FunctionDecl *OperatorDelete = nullptr;
2181 unsigned Alignment =
2182 AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType);
2183 unsigned NewAlignment = Context.getTargetInfo().getNewAlign();
2184 bool PassAlignment = getLangOpts().AlignedAllocation &&
2185 Alignment > NewAlignment;
2186
2187 AllocationFunctionScope Scope = UseGlobal ? AFS_Global : AFS_Both;
2188 if (!AllocType->isDependentType() &&
2189 !Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
2190 FindAllocationFunctions(
2191 StartLoc, SourceRange(PlacementLParen, PlacementRParen), Scope, Scope,
2192 AllocType, ArraySize.hasValue(), PassAlignment, PlacementArgs,
2193 OperatorNew, OperatorDelete))
2194 return ExprError();
2195
2196 // If this is an array allocation, compute whether the usual array
2197 // deallocation function for the type has a size_t parameter.
2198 bool UsualArrayDeleteWantsSize = false;
2199 if (ArraySize && !AllocType->isDependentType())
2200 UsualArrayDeleteWantsSize =
2201 doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);
2202
2203 SmallVector<Expr *, 8> AllPlaceArgs;
2204 if (OperatorNew) {
2205 auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();
2206 VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
2207 : VariadicDoesNotApply;
2208
2209 // We've already converted the placement args, just fill in any default
2210 // arguments. Skip the first parameter because we don't have a corresponding
2211 // argument. Skip the second parameter too if we're passing in the
2212 // alignment; we've already filled it in.
2213 unsigned NumImplicitArgs = PassAlignment ? 2 : 1;
2214 if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto,
2215 NumImplicitArgs, PlacementArgs, AllPlaceArgs,
2216 CallType))
2217 return ExprError();
2218
2219 if (!AllPlaceArgs.empty())
2220 PlacementArgs = AllPlaceArgs;
2221
2222 // We would like to perform some checking on the given `operator new` call,
2223 // but the PlacementArgs does not contain the implicit arguments,
2224 // namely allocation size and maybe allocation alignment,
2225 // so we need to conjure them.
2226
2227 QualType SizeTy = Context.getSizeType();
2228 unsigned SizeTyWidth = Context.getTypeSize(SizeTy);
2229
2230 llvm::APInt SingleEltSize(
2231 SizeTyWidth, Context.getTypeSizeInChars(AllocType).getQuantity());
2232
2233 // How many bytes do we want to allocate here?
2234 llvm::Optional<llvm::APInt> AllocationSize;
2235 if (!ArraySize.hasValue() && !AllocType->isDependentType()) {
2236 // For non-array operator new, we only want to allocate one element.
2237 AllocationSize = SingleEltSize;
2238 } else if (KnownArraySize.hasValue() && !AllocType->isDependentType()) {
2239 // For array operator new, only deal with static array size case.
2240 bool Overflow;
2241 AllocationSize = llvm::APInt(SizeTyWidth, *KnownArraySize)
2242 .umul_ov(SingleEltSize, Overflow);
2243 (void)Overflow;
2244 assert(
2245 !Overflow &&
2246 "Expected that all the overflows would have been handled already.");
2247 }
2248
2249 IntegerLiteral AllocationSizeLiteral(
2250 Context, AllocationSize.getValueOr(llvm::APInt::getZero(SizeTyWidth)),
2251 SizeTy, SourceLocation());
2252 // Otherwise, if we failed to constant-fold the allocation size, we'll
2253 // just give up and pass-in something opaque, that isn't a null pointer.
2254 OpaqueValueExpr OpaqueAllocationSize(SourceLocation(), SizeTy, VK_PRValue,
2255 OK_Ordinary, /*SourceExpr=*/nullptr);
2256
2257 // Let's synthesize the alignment argument in case we will need it.
2258 // Since we *really* want to allocate these on stack, this is slightly ugly
2259 // because there might not be a `std::align_val_t` type.
2260 EnumDecl *StdAlignValT = getStdAlignValT();
2261 QualType AlignValT =
2262 StdAlignValT ? Context.getTypeDeclType(StdAlignValT) : SizeTy;
2263 IntegerLiteral AlignmentLiteral(
2264 Context,
2265 llvm::APInt(Context.getTypeSize(SizeTy),
2266 Alignment / Context.getCharWidth()),
2267 SizeTy, SourceLocation());
2268 ImplicitCastExpr DesiredAlignment(ImplicitCastExpr::OnStack, AlignValT,
2269 CK_IntegralCast, &AlignmentLiteral,
2270 VK_PRValue, FPOptionsOverride());
2271
2272 // Adjust placement args by prepending conjured size and alignment exprs.
2273 llvm::SmallVector<Expr *, 8> CallArgs;
2274 CallArgs.reserve(NumImplicitArgs + PlacementArgs.size());
2275 CallArgs.emplace_back(AllocationSize.hasValue()
2276 ? static_cast<Expr *>(&AllocationSizeLiteral)
2277 : &OpaqueAllocationSize);
2278 if (PassAlignment)
2279 CallArgs.emplace_back(&DesiredAlignment);
2280 CallArgs.insert(CallArgs.end(), PlacementArgs.begin(), PlacementArgs.end());
2281
2282 DiagnoseSentinelCalls(OperatorNew, PlacementLParen, CallArgs);
2283
2284 checkCall(OperatorNew, Proto, /*ThisArg=*/nullptr, CallArgs,
2285 /*IsMemberFunction=*/false, StartLoc, Range, CallType);
2286
2287 // Warn if the type is over-aligned and is being allocated by (unaligned)
2288 // global operator new.
2289 if (PlacementArgs.empty() && !PassAlignment &&
2290 (OperatorNew->isImplicit() ||
2291 (OperatorNew->getBeginLoc().isValid() &&
2292 getSourceManager().isInSystemHeader(OperatorNew->getBeginLoc())))) {
2293 if (Alignment > NewAlignment)
2294 Diag(StartLoc, diag::warn_overaligned_type)
2295 << AllocType
2296 << unsigned(Alignment / Context.getCharWidth())
2297 << unsigned(NewAlignment / Context.getCharWidth());
2298 }
2299 }
2300
2301 // Array 'new' can't have any initializers except empty parentheses.
2302 // Initializer lists are also allowed, in C++11. Rely on the parser for the
2303 // dialect distinction.
2304 if (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) {
2305 SourceRange InitRange(Inits[0]->getBeginLoc(),
2306 Inits[NumInits - 1]->getEndLoc());
2307 Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
2308 return ExprError();
2309 }
2310
2311 // If we can perform the initialization, and we've not already done so,
2312 // do it now.
2313 if (!AllocType->isDependentType() &&
2314 !Expr::hasAnyTypeDependentArguments(
2315 llvm::makeArrayRef(Inits, NumInits))) {
2316 // The type we initialize is the complete type, including the array bound.
2317 QualType InitType;
2318 if (KnownArraySize)
2319 InitType = Context.getConstantArrayType(
2320 AllocType,
2321 llvm::APInt(Context.getTypeSize(Context.getSizeType()),
2322 *KnownArraySize),
2323 *ArraySize, ArrayType::Normal, 0);
2324 else if (ArraySize)
2325 InitType =
2326 Context.getIncompleteArrayType(AllocType, ArrayType::Normal, 0);
2327 else
2328 InitType = AllocType;
2329
2330 InitializedEntity Entity
2331 = InitializedEntity::InitializeNew(StartLoc, InitType);
2332 InitializationSequence InitSeq(*this, Entity, Kind,
2333 MultiExprArg(Inits, NumInits));
2334 ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind,
2335 MultiExprArg(Inits, NumInits));
2336 if (FullInit.isInvalid())
2337 return ExprError();
2338
2339 // FullInit is our initializer; strip off CXXBindTemporaryExprs, because
2340 // we don't want the initialized object to be destructed.
2341 // FIXME: We should not create these in the first place.
2342 if (CXXBindTemporaryExpr *Binder =
2343 dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
2344 FullInit = Binder->getSubExpr();
2345
2346 Initializer = FullInit.get();
2347
2348 // FIXME: If we have a KnownArraySize, check that the array bound of the
2349 // initializer is no greater than that constant value.
2350
2351 if (ArraySize && !*ArraySize) {
2352 auto *CAT = Context.getAsConstantArrayType(Initializer->getType());
2353 if (CAT) {
2354 // FIXME: Track that the array size was inferred rather than explicitly
2355 // specified.
2356 ArraySize = IntegerLiteral::Create(
2357 Context, CAT->getSize(), Context.getSizeType(), TypeRange.getEnd());
2358 } else {
2359 Diag(TypeRange.getEnd(), diag::err_new_array_size_unknown_from_init)
2360 << Initializer->getSourceRange();
2361 }
2362 }
2363 }
2364
2365 // Mark the new and delete operators as referenced.
2366 if (OperatorNew) {
2367 if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
2368 return ExprError();
2369 MarkFunctionReferenced(StartLoc, OperatorNew);
2370 }
2371 if (OperatorDelete) {
2372 if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
2373 return ExprError();
2374 MarkFunctionReferenced(StartLoc, OperatorDelete);
2375 }
2376
2377 return CXXNewExpr::Create(Context, UseGlobal, OperatorNew, OperatorDelete,
2378 PassAlignment, UsualArrayDeleteWantsSize,
2379 PlacementArgs, TypeIdParens, ArraySize, initStyle,
2380 Initializer, ResultType, AllocTypeInfo, Range,
2381 DirectInitRange);
2382 }
2383
2384 /// Checks that a type is suitable as the allocated type
2385 /// in a new-expression.
CheckAllocatedType(QualType AllocType,SourceLocation Loc,SourceRange R)2386 bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc,
2387 SourceRange R) {
2388 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
2389 // abstract class type or array thereof.
2390 if (AllocType->isFunctionType())
2391 return Diag(Loc, diag::err_bad_new_type)
2392 << AllocType << 0 << R;
2393 else if (AllocType->isReferenceType())
2394 return Diag(Loc, diag::err_bad_new_type)
2395 << AllocType << 1 << R;
2396 else if (!AllocType->isDependentType() &&
2397 RequireCompleteSizedType(
2398 Loc, AllocType, diag::err_new_incomplete_or_sizeless_type, R))
2399 return true;
2400 else if (RequireNonAbstractType(Loc, AllocType,
2401 diag::err_allocation_of_abstract_type))
2402 return true;
2403 else if (AllocType->isVariablyModifiedType())
2404 return Diag(Loc, diag::err_variably_modified_new_type)
2405 << AllocType;
2406 else if (AllocType.getAddressSpace() != LangAS::Default &&
2407 !getLangOpts().OpenCLCPlusPlus)
2408 return Diag(Loc, diag::err_address_space_qualified_new)
2409 << AllocType.getUnqualifiedType()
2410 << AllocType.getQualifiers().getAddressSpaceAttributePrintValue();
2411 else if (getLangOpts().ObjCAutoRefCount) {
2412 if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
2413 QualType BaseAllocType = Context.getBaseElementType(AT);
2414 if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
2415 BaseAllocType->isObjCLifetimeType())
2416 return Diag(Loc, diag::err_arc_new_array_without_ownership)
2417 << BaseAllocType;
2418 }
2419 }
2420
2421 return false;
2422 }
2423
resolveAllocationOverload(Sema & S,LookupResult & R,SourceRange Range,SmallVectorImpl<Expr * > & Args,bool & PassAlignment,FunctionDecl * & Operator,OverloadCandidateSet * AlignedCandidates,Expr * AlignArg,bool Diagnose)2424 static bool resolveAllocationOverload(
2425 Sema &S, LookupResult &R, SourceRange Range, SmallVectorImpl<Expr *> &Args,
2426 bool &PassAlignment, FunctionDecl *&Operator,
2427 OverloadCandidateSet *AlignedCandidates, Expr *AlignArg, bool Diagnose) {
2428 OverloadCandidateSet Candidates(R.getNameLoc(),
2429 OverloadCandidateSet::CSK_Normal);
2430 for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
2431 Alloc != AllocEnd; ++Alloc) {
2432 // Even member operator new/delete are implicitly treated as
2433 // static, so don't use AddMemberCandidate.
2434 NamedDecl *D = (*Alloc)->getUnderlyingDecl();
2435
2436 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
2437 S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
2438 /*ExplicitTemplateArgs=*/nullptr, Args,
2439 Candidates,
2440 /*SuppressUserConversions=*/false);
2441 continue;
2442 }
2443
2444 FunctionDecl *Fn = cast<FunctionDecl>(D);
2445 S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
2446 /*SuppressUserConversions=*/false);
2447 }
2448
2449 // Do the resolution.
2450 OverloadCandidateSet::iterator Best;
2451 switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
2452 case OR_Success: {
2453 // Got one!
2454 FunctionDecl *FnDecl = Best->Function;
2455 if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(),
2456 Best->FoundDecl) == Sema::AR_inaccessible)
2457 return true;
2458
2459 Operator = FnDecl;
2460 return false;
2461 }
2462
2463 case OR_No_Viable_Function:
2464 // C++17 [expr.new]p13:
2465 // If no matching function is found and the allocated object type has
2466 // new-extended alignment, the alignment argument is removed from the
2467 // argument list, and overload resolution is performed again.
2468 if (PassAlignment) {
2469 PassAlignment = false;
2470 AlignArg = Args[1];
2471 Args.erase(Args.begin() + 1);
2472 return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2473 Operator, &Candidates, AlignArg,
2474 Diagnose);
2475 }
2476
2477 // MSVC will fall back on trying to find a matching global operator new
2478 // if operator new[] cannot be found. Also, MSVC will leak by not
2479 // generating a call to operator delete or operator delete[], but we
2480 // will not replicate that bug.
2481 // FIXME: Find out how this interacts with the std::align_val_t fallback
2482 // once MSVC implements it.
2483 if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New &&
2484 S.Context.getLangOpts().MSVCCompat) {
2485 R.clear();
2486 R.setLookupName(S.Context.DeclarationNames.getCXXOperatorName(OO_New));
2487 S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl());
2488 // FIXME: This will give bad diagnostics pointing at the wrong functions.
2489 return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2490 Operator, /*Candidates=*/nullptr,
2491 /*AlignArg=*/nullptr, Diagnose);
2492 }
2493
2494 if (Diagnose) {
2495 // If this is an allocation of the form 'new (p) X' for some object
2496 // pointer p (or an expression that will decay to such a pointer),
2497 // diagnose the missing inclusion of <new>.
2498 if (!R.isClassLookup() && Args.size() == 2 &&
2499 (Args[1]->getType()->isObjectPointerType() ||
2500 Args[1]->getType()->isArrayType())) {
2501 S.Diag(R.getNameLoc(), diag::err_need_header_before_placement_new)
2502 << R.getLookupName() << Range;
2503 // Listing the candidates is unlikely to be useful; skip it.
2504 return true;
2505 }
2506
2507 // Finish checking all candidates before we note any. This checking can
2508 // produce additional diagnostics so can't be interleaved with our
2509 // emission of notes.
2510 //
2511 // For an aligned allocation, separately check the aligned and unaligned
2512 // candidates with their respective argument lists.
2513 SmallVector<OverloadCandidate*, 32> Cands;
2514 SmallVector<OverloadCandidate*, 32> AlignedCands;
2515 llvm::SmallVector<Expr*, 4> AlignedArgs;
2516 if (AlignedCandidates) {
2517 auto IsAligned = [](OverloadCandidate &C) {
2518 return C.Function->getNumParams() > 1 &&
2519 C.Function->getParamDecl(1)->getType()->isAlignValT();
2520 };
2521 auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); };
2522
2523 AlignedArgs.reserve(Args.size() + 1);
2524 AlignedArgs.push_back(Args[0]);
2525 AlignedArgs.push_back(AlignArg);
2526 AlignedArgs.append(Args.begin() + 1, Args.end());
2527 AlignedCands = AlignedCandidates->CompleteCandidates(
2528 S, OCD_AllCandidates, AlignedArgs, R.getNameLoc(), IsAligned);
2529
2530 Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
2531 R.getNameLoc(), IsUnaligned);
2532 } else {
2533 Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
2534 R.getNameLoc());
2535 }
2536
2537 S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call)
2538 << R.getLookupName() << Range;
2539 if (AlignedCandidates)
2540 AlignedCandidates->NoteCandidates(S, AlignedArgs, AlignedCands, "",
2541 R.getNameLoc());
2542 Candidates.NoteCandidates(S, Args, Cands, "", R.getNameLoc());
2543 }
2544 return true;
2545
2546 case OR_Ambiguous:
2547 if (Diagnose) {
2548 Candidates.NoteCandidates(
2549 PartialDiagnosticAt(R.getNameLoc(),
2550 S.PDiag(diag::err_ovl_ambiguous_call)
2551 << R.getLookupName() << Range),
2552 S, OCD_AmbiguousCandidates, Args);
2553 }
2554 return true;
2555
2556 case OR_Deleted: {
2557 if (Diagnose) {
2558 Candidates.NoteCandidates(
2559 PartialDiagnosticAt(R.getNameLoc(),
2560 S.PDiag(diag::err_ovl_deleted_call)
2561 << R.getLookupName() << Range),
2562 S, OCD_AllCandidates, Args);
2563 }
2564 return true;
2565 }
2566 }
2567 llvm_unreachable("Unreachable, bad result from BestViableFunction");
2568 }
2569
FindAllocationFunctions(SourceLocation StartLoc,SourceRange Range,AllocationFunctionScope NewScope,AllocationFunctionScope DeleteScope,QualType AllocType,bool IsArray,bool & PassAlignment,MultiExprArg PlaceArgs,FunctionDecl * & OperatorNew,FunctionDecl * & OperatorDelete,bool Diagnose)2570 bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
2571 AllocationFunctionScope NewScope,
2572 AllocationFunctionScope DeleteScope,
2573 QualType AllocType, bool IsArray,
2574 bool &PassAlignment, MultiExprArg PlaceArgs,
2575 FunctionDecl *&OperatorNew,
2576 FunctionDecl *&OperatorDelete,
2577 bool Diagnose) {
2578 // --- Choosing an allocation function ---
2579 // C++ 5.3.4p8 - 14 & 18
2580 // 1) If looking in AFS_Global scope for allocation functions, only look in
2581 // the global scope. Else, if AFS_Class, only look in the scope of the
2582 // allocated class. If AFS_Both, look in both.
2583 // 2) If an array size is given, look for operator new[], else look for
2584 // operator new.
2585 // 3) The first argument is always size_t. Append the arguments from the
2586 // placement form.
2587
2588 SmallVector<Expr*, 8> AllocArgs;
2589 AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size());
2590
2591 // We don't care about the actual value of these arguments.
2592 // FIXME: Should the Sema create the expression and embed it in the syntax
2593 // tree? Or should the consumer just recalculate the value?
2594 // FIXME: Using a dummy value will interact poorly with attribute enable_if.
2595 IntegerLiteral Size(
2596 Context, llvm::APInt::getZero(Context.getTargetInfo().getPointerWidth(0)),
2597 Context.getSizeType(), SourceLocation());
2598 AllocArgs.push_back(&Size);
2599
2600 QualType AlignValT = Context.VoidTy;
2601 if (PassAlignment) {
2602 DeclareGlobalNewDelete();
2603 AlignValT = Context.getTypeDeclType(getStdAlignValT());
2604 }
2605 CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation());
2606 if (PassAlignment)
2607 AllocArgs.push_back(&Align);
2608
2609 AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end());
2610
2611 // C++ [expr.new]p8:
2612 // If the allocated type is a non-array type, the allocation
2613 // function's name is operator new and the deallocation function's
2614 // name is operator delete. If the allocated type is an array
2615 // type, the allocation function's name is operator new[] and the
2616 // deallocation function's name is operator delete[].
2617 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
2618 IsArray ? OO_Array_New : OO_New);
2619
2620 QualType AllocElemType = Context.getBaseElementType(AllocType);
2621
2622 // Find the allocation function.
2623 {
2624 LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName);
2625
2626 // C++1z [expr.new]p9:
2627 // If the new-expression begins with a unary :: operator, the allocation
2628 // function's name is looked up in the global scope. Otherwise, if the
2629 // allocated type is a class type T or array thereof, the allocation
2630 // function's name is looked up in the scope of T.
2631 if (AllocElemType->isRecordType() && NewScope != AFS_Global)
2632 LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl());
2633
2634 // We can see ambiguity here if the allocation function is found in
2635 // multiple base classes.
2636 if (R.isAmbiguous())
2637 return true;
2638
2639 // If this lookup fails to find the name, or if the allocated type is not
2640 // a class type, the allocation function's name is looked up in the
2641 // global scope.
2642 if (R.empty()) {
2643 if (NewScope == AFS_Class)
2644 return true;
2645
2646 LookupQualifiedName(R, Context.getTranslationUnitDecl());
2647 }
2648
2649 if (getLangOpts().OpenCLCPlusPlus && R.empty()) {
2650 if (PlaceArgs.empty()) {
2651 Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
2652 } else {
2653 Diag(StartLoc, diag::err_openclcxx_placement_new);
2654 }
2655 return true;
2656 }
2657
2658 assert(!R.empty() && "implicitly declared allocation functions not found");
2659 assert(!R.isAmbiguous() && "global allocation functions are ambiguous");
2660
2661 // We do our own custom access checks below.
2662 R.suppressDiagnostics();
2663
2664 if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment,
2665 OperatorNew, /*Candidates=*/nullptr,
2666 /*AlignArg=*/nullptr, Diagnose))
2667 return true;
2668 }
2669
2670 // We don't need an operator delete if we're running under -fno-exceptions.
2671 if (!getLangOpts().Exceptions) {
2672 OperatorDelete = nullptr;
2673 return false;
2674 }
2675
2676 // Note, the name of OperatorNew might have been changed from array to
2677 // non-array by resolveAllocationOverload.
2678 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
2679 OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New
2680 ? OO_Array_Delete
2681 : OO_Delete);
2682
2683 // C++ [expr.new]p19:
2684 //
2685 // If the new-expression begins with a unary :: operator, the
2686 // deallocation function's name is looked up in the global
2687 // scope. Otherwise, if the allocated type is a class type T or an
2688 // array thereof, the deallocation function's name is looked up in
2689 // the scope of T. If this lookup fails to find the name, or if
2690 // the allocated type is not a class type or array thereof, the
2691 // deallocation function's name is looked up in the global scope.
2692 LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
2693 if (AllocElemType->isRecordType() && DeleteScope != AFS_Global) {
2694 auto *RD =
2695 cast<CXXRecordDecl>(AllocElemType->castAs<RecordType>()->getDecl());
2696 LookupQualifiedName(FoundDelete, RD);
2697 }
2698 if (FoundDelete.isAmbiguous())
2699 return true; // FIXME: clean up expressions?
2700
2701 // Filter out any destroying operator deletes. We can't possibly call such a
2702 // function in this context, because we're handling the case where the object
2703 // was not successfully constructed.
2704 // FIXME: This is not covered by the language rules yet.
2705 {
2706 LookupResult::Filter Filter = FoundDelete.makeFilter();
2707 while (Filter.hasNext()) {
2708 auto *FD = dyn_cast<FunctionDecl>(Filter.next()->getUnderlyingDecl());
2709 if (FD && FD->isDestroyingOperatorDelete())
2710 Filter.erase();
2711 }
2712 Filter.done();
2713 }
2714
2715 bool FoundGlobalDelete = FoundDelete.empty();
2716 if (FoundDelete.empty()) {
2717 FoundDelete.clear(LookupOrdinaryName);
2718
2719 if (DeleteScope == AFS_Class)
2720 return true;
2721
2722 DeclareGlobalNewDelete();
2723 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
2724 }
2725
2726 FoundDelete.suppressDiagnostics();
2727
2728 SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches;
2729
2730 // Whether we're looking for a placement operator delete is dictated
2731 // by whether we selected a placement operator new, not by whether
2732 // we had explicit placement arguments. This matters for things like
2733 // struct A { void *operator new(size_t, int = 0); ... };
2734 // A *a = new A()
2735 //
2736 // We don't have any definition for what a "placement allocation function"
2737 // is, but we assume it's any allocation function whose
2738 // parameter-declaration-clause is anything other than (size_t).
2739 //
2740 // FIXME: Should (size_t, std::align_val_t) also be considered non-placement?
2741 // This affects whether an exception from the constructor of an overaligned
2742 // type uses the sized or non-sized form of aligned operator delete.
2743 bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 ||
2744 OperatorNew->isVariadic();
2745
2746 if (isPlacementNew) {
2747 // C++ [expr.new]p20:
2748 // A declaration of a placement deallocation function matches the
2749 // declaration of a placement allocation function if it has the
2750 // same number of parameters and, after parameter transformations
2751 // (8.3.5), all parameter types except the first are
2752 // identical. [...]
2753 //
2754 // To perform this comparison, we compute the function type that
2755 // the deallocation function should have, and use that type both
2756 // for template argument deduction and for comparison purposes.
2757 QualType ExpectedFunctionType;
2758 {
2759 auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();
2760
2761 SmallVector<QualType, 4> ArgTypes;
2762 ArgTypes.push_back(Context.VoidPtrTy);
2763 for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
2764 ArgTypes.push_back(Proto->getParamType(I));
2765
2766 FunctionProtoType::ExtProtoInfo EPI;
2767 // FIXME: This is not part of the standard's rule.
2768 EPI.Variadic = Proto->isVariadic();
2769
2770 ExpectedFunctionType
2771 = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
2772 }
2773
2774 for (LookupResult::iterator D = FoundDelete.begin(),
2775 DEnd = FoundDelete.end();
2776 D != DEnd; ++D) {
2777 FunctionDecl *Fn = nullptr;
2778 if (FunctionTemplateDecl *FnTmpl =
2779 dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
2780 // Perform template argument deduction to try to match the
2781 // expected function type.
2782 TemplateDeductionInfo Info(StartLoc);
2783 if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
2784 Info))
2785 continue;
2786 } else
2787 Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());
2788
2789 if (Context.hasSameType(adjustCCAndNoReturn(Fn->getType(),
2790 ExpectedFunctionType,
2791 /*AdjustExcpetionSpec*/true),
2792 ExpectedFunctionType))
2793 Matches.push_back(std::make_pair(D.getPair(), Fn));
2794 }
2795
2796 if (getLangOpts().CUDA)
2797 EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches);
2798 } else {
2799 // C++1y [expr.new]p22:
2800 // For a non-placement allocation function, the normal deallocation
2801 // function lookup is used
2802 //
2803 // Per [expr.delete]p10, this lookup prefers a member operator delete
2804 // without a size_t argument, but prefers a non-member operator delete
2805 // with a size_t where possible (which it always is in this case).
2806 llvm::SmallVector<UsualDeallocFnInfo, 4> BestDeallocFns;
2807 UsualDeallocFnInfo Selected = resolveDeallocationOverload(
2808 *this, FoundDelete, /*WantSize*/ FoundGlobalDelete,
2809 /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType),
2810 &BestDeallocFns);
2811 if (Selected)
2812 Matches.push_back(std::make_pair(Selected.Found, Selected.FD));
2813 else {
2814 // If we failed to select an operator, all remaining functions are viable
2815 // but ambiguous.
2816 for (auto Fn : BestDeallocFns)
2817 Matches.push_back(std::make_pair(Fn.Found, Fn.FD));
2818 }
2819 }
2820
2821 // C++ [expr.new]p20:
2822 // [...] If the lookup finds a single matching deallocation
2823 // function, that function will be called; otherwise, no
2824 // deallocation function will be called.
2825 if (Matches.size() == 1) {
2826 OperatorDelete = Matches[0].second;
2827
2828 // C++1z [expr.new]p23:
2829 // If the lookup finds a usual deallocation function (3.7.4.2)
2830 // with a parameter of type std::size_t and that function, considered
2831 // as a placement deallocation function, would have been
2832 // selected as a match for the allocation function, the program
2833 // is ill-formed.
2834 if (getLangOpts().CPlusPlus11 && isPlacementNew &&
2835 isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
2836 UsualDeallocFnInfo Info(*this,
2837 DeclAccessPair::make(OperatorDelete, AS_public));
2838 // Core issue, per mail to core reflector, 2016-10-09:
2839 // If this is a member operator delete, and there is a corresponding
2840 // non-sized member operator delete, this isn't /really/ a sized
2841 // deallocation function, it just happens to have a size_t parameter.
2842 bool IsSizedDelete = Info.HasSizeT;
2843 if (IsSizedDelete && !FoundGlobalDelete) {
2844 auto NonSizedDelete =
2845 resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false,
2846 /*WantAlign*/Info.HasAlignValT);
2847 if (NonSizedDelete && !NonSizedDelete.HasSizeT &&
2848 NonSizedDelete.HasAlignValT == Info.HasAlignValT)
2849 IsSizedDelete = false;
2850 }
2851
2852 if (IsSizedDelete) {
2853 SourceRange R = PlaceArgs.empty()
2854 ? SourceRange()
2855 : SourceRange(PlaceArgs.front()->getBeginLoc(),
2856 PlaceArgs.back()->getEndLoc());
2857 Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R;
2858 if (!OperatorDelete->isImplicit())
2859 Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
2860 << DeleteName;
2861 }
2862 }
2863
2864 CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
2865 Matches[0].first);
2866 } else if (!Matches.empty()) {
2867 // We found multiple suitable operators. Per [expr.new]p20, that means we
2868 // call no 'operator delete' function, but we should at least warn the user.
2869 // FIXME: Suppress this warning if the construction cannot throw.
2870 Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found)
2871 << DeleteName << AllocElemType;
2872
2873 for (auto &Match : Matches)
2874 Diag(Match.second->getLocation(),
2875 diag::note_member_declared_here) << DeleteName;
2876 }
2877
2878 return false;
2879 }
2880
2881 /// DeclareGlobalNewDelete - Declare the global forms of operator new and
2882 /// delete. These are:
2883 /// @code
2884 /// // C++03:
2885 /// void* operator new(std::size_t) throw(std::bad_alloc);
2886 /// void* operator new[](std::size_t) throw(std::bad_alloc);
2887 /// void operator delete(void *) throw();
2888 /// void operator delete[](void *) throw();
2889 /// // C++11:
2890 /// void* operator new(std::size_t);
2891 /// void* operator new[](std::size_t);
2892 /// void operator delete(void *) noexcept;
2893 /// void operator delete[](void *) noexcept;
2894 /// // C++1y:
2895 /// void* operator new(std::size_t);
2896 /// void* operator new[](std::size_t);
2897 /// void operator delete(void *) noexcept;
2898 /// void operator delete[](void *) noexcept;
2899 /// void operator delete(void *, std::size_t) noexcept;
2900 /// void operator delete[](void *, std::size_t) noexcept;
2901 /// @endcode
2902 /// Note that the placement and nothrow forms of new are *not* implicitly
2903 /// declared. Their use requires including \<new\>.
DeclareGlobalNewDelete()2904 void Sema::DeclareGlobalNewDelete() {
2905 if (GlobalNewDeleteDeclared)
2906 return;
2907
2908 // The implicitly declared new and delete operators
2909 // are not supported in OpenCL.
2910 if (getLangOpts().OpenCLCPlusPlus)
2911 return;
2912
2913 // C++ [basic.std.dynamic]p2:
2914 // [...] The following allocation and deallocation functions (18.4) are
2915 // implicitly declared in global scope in each translation unit of a
2916 // program
2917 //
2918 // C++03:
2919 // void* operator new(std::size_t) throw(std::bad_alloc);
2920 // void* operator new[](std::size_t) throw(std::bad_alloc);
2921 // void operator delete(void*) throw();
2922 // void operator delete[](void*) throw();
2923 // C++11:
2924 // void* operator new(std::size_t);
2925 // void* operator new[](std::size_t);
2926 // void operator delete(void*) noexcept;
2927 // void operator delete[](void*) noexcept;
2928 // C++1y:
2929 // void* operator new(std::size_t);
2930 // void* operator new[](std::size_t);
2931 // void operator delete(void*) noexcept;
2932 // void operator delete[](void*) noexcept;
2933 // void operator delete(void*, std::size_t) noexcept;
2934 // void operator delete[](void*, std::size_t) noexcept;
2935 //
2936 // These implicit declarations introduce only the function names operator
2937 // new, operator new[], operator delete, operator delete[].
2938 //
2939 // Here, we need to refer to std::bad_alloc, so we will implicitly declare
2940 // "std" or "bad_alloc" as necessary to form the exception specification.
2941 // However, we do not make these implicit declarations visible to name
2942 // lookup.
2943 if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
2944 // The "std::bad_alloc" class has not yet been declared, so build it
2945 // implicitly.
2946 StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class,
2947 getOrCreateStdNamespace(),
2948 SourceLocation(), SourceLocation(),
2949 &PP.getIdentifierTable().get("bad_alloc"),
2950 nullptr);
2951 getStdBadAlloc()->setImplicit(true);
2952 }
2953 if (!StdAlignValT && getLangOpts().AlignedAllocation) {
2954 // The "std::align_val_t" enum class has not yet been declared, so build it
2955 // implicitly.
2956 auto *AlignValT = EnumDecl::Create(
2957 Context, getOrCreateStdNamespace(), SourceLocation(), SourceLocation(),
2958 &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true);
2959 AlignValT->setIntegerType(Context.getSizeType());
2960 AlignValT->setPromotionType(Context.getSizeType());
2961 AlignValT->setImplicit(true);
2962 StdAlignValT = AlignValT;
2963 }
2964
2965 GlobalNewDeleteDeclared = true;
2966
2967 QualType VoidPtr = Context.getPointerType(Context.VoidTy);
2968 QualType SizeT = Context.getSizeType();
2969
2970 auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind,
2971 QualType Return, QualType Param) {
2972 llvm::SmallVector<QualType, 3> Params;
2973 Params.push_back(Param);
2974
2975 // Create up to four variants of the function (sized/aligned).
2976 bool HasSizedVariant = getLangOpts().SizedDeallocation &&
2977 (Kind == OO_Delete || Kind == OO_Array_Delete);
2978 bool HasAlignedVariant = getLangOpts().AlignedAllocation;
2979
2980 int NumSizeVariants = (HasSizedVariant ? 2 : 1);
2981 int NumAlignVariants = (HasAlignedVariant ? 2 : 1);
2982 for (int Sized = 0; Sized < NumSizeVariants; ++Sized) {
2983 if (Sized)
2984 Params.push_back(SizeT);
2985
2986 for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) {
2987 if (Aligned)
2988 Params.push_back(Context.getTypeDeclType(getStdAlignValT()));
2989
2990 DeclareGlobalAllocationFunction(
2991 Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params);
2992
2993 if (Aligned)
2994 Params.pop_back();
2995 }
2996 }
2997 };
2998
2999 DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT);
3000 DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT);
3001 DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr);
3002 DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr);
3003 }
3004
3005 /// DeclareGlobalAllocationFunction - Declares a single implicit global
3006 /// allocation function if it doesn't already exist.
DeclareGlobalAllocationFunction(DeclarationName Name,QualType Return,ArrayRef<QualType> Params)3007 void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
3008 QualType Return,
3009 ArrayRef<QualType> Params) {
3010 DeclContext *GlobalCtx = Context.getTranslationUnitDecl();
3011
3012 // Check if this function is already declared.
3013 DeclContext::lookup_result R = GlobalCtx->lookup(Name);
3014 for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
3015 Alloc != AllocEnd; ++Alloc) {
3016 // Only look at non-template functions, as it is the predefined,
3017 // non-templated allocation function we are trying to declare here.
3018 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
3019 if (Func->getNumParams() == Params.size()) {
3020 llvm::SmallVector<QualType, 3> FuncParams;
3021 for (auto *P : Func->parameters())
3022 FuncParams.push_back(
3023 Context.getCanonicalType(P->getType().getUnqualifiedType()));
3024 if (llvm::makeArrayRef(FuncParams) == Params) {
3025 // Make the function visible to name lookup, even if we found it in
3026 // an unimported module. It either is an implicitly-declared global
3027 // allocation function, or is suppressing that function.
3028 Func->setVisibleDespiteOwningModule();
3029 return;
3030 }
3031 }
3032 }
3033 }
3034
3035 FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
3036 /*IsVariadic=*/false, /*IsCXXMethod=*/false, /*IsBuiltin=*/true));
3037
3038 QualType BadAllocType;
3039 bool HasBadAllocExceptionSpec
3040 = (Name.getCXXOverloadedOperator() == OO_New ||
3041 Name.getCXXOverloadedOperator() == OO_Array_New);
3042 if (HasBadAllocExceptionSpec) {
3043 if (!getLangOpts().CPlusPlus11) {
3044 BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
3045 assert(StdBadAlloc && "Must have std::bad_alloc declared");
3046 EPI.ExceptionSpec.Type = EST_Dynamic;
3047 EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
3048 }
3049 if (getLangOpts().NewInfallible) {
3050 EPI.ExceptionSpec.Type = EST_DynamicNone;
3051 }
3052 } else {
3053 EPI.ExceptionSpec =
3054 getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
3055 }
3056
3057 auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) {
3058 QualType FnType = Context.getFunctionType(Return, Params, EPI);
3059 FunctionDecl *Alloc = FunctionDecl::Create(
3060 Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, FnType,
3061 /*TInfo=*/nullptr, SC_None, getCurFPFeatures().isFPConstrained(), false,
3062 true);
3063 Alloc->setImplicit();
3064 // Global allocation functions should always be visible.
3065 Alloc->setVisibleDespiteOwningModule();
3066
3067 if (HasBadAllocExceptionSpec && getLangOpts().NewInfallible)
3068 Alloc->addAttr(
3069 ReturnsNonNullAttr::CreateImplicit(Context, Alloc->getLocation()));
3070
3071 Alloc->addAttr(VisibilityAttr::CreateImplicit(
3072 Context, LangOpts.GlobalAllocationFunctionVisibilityHidden
3073 ? VisibilityAttr::Hidden
3074 : VisibilityAttr::Default));
3075
3076 llvm::SmallVector<ParmVarDecl *, 3> ParamDecls;
3077 for (QualType T : Params) {
3078 ParamDecls.push_back(ParmVarDecl::Create(
3079 Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T,
3080 /*TInfo=*/nullptr, SC_None, nullptr));
3081 ParamDecls.back()->setImplicit();
3082 }
3083 Alloc->setParams(ParamDecls);
3084 if (ExtraAttr)
3085 Alloc->addAttr(ExtraAttr);
3086 AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(Alloc);
3087 Context.getTranslationUnitDecl()->addDecl(Alloc);
3088 IdResolver.tryAddTopLevelDecl(Alloc, Name);
3089 };
3090
3091 if (!LangOpts.CUDA)
3092 CreateAllocationFunctionDecl(nullptr);
3093 else {
3094 // Host and device get their own declaration so each can be
3095 // defined or re-declared independently.
3096 CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context));
3097 CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context));
3098 }
3099 }
3100
FindUsualDeallocationFunction(SourceLocation StartLoc,bool CanProvideSize,bool Overaligned,DeclarationName Name)3101 FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc,
3102 bool CanProvideSize,
3103 bool Overaligned,
3104 DeclarationName Name) {
3105 DeclareGlobalNewDelete();
3106
3107 LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
3108 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
3109
3110 // FIXME: It's possible for this to result in ambiguity, through a
3111 // user-declared variadic operator delete or the enable_if attribute. We
3112 // should probably not consider those cases to be usual deallocation
3113 // functions. But for now we just make an arbitrary choice in that case.
3114 auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize,
3115 Overaligned);
3116 assert(Result.FD && "operator delete missing from global scope?");
3117 return Result.FD;
3118 }
3119
FindDeallocationFunctionForDestructor(SourceLocation Loc,CXXRecordDecl * RD)3120 FunctionDecl *Sema::FindDeallocationFunctionForDestructor(SourceLocation Loc,
3121 CXXRecordDecl *RD) {
3122 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Delete);
3123
3124 FunctionDecl *OperatorDelete = nullptr;
3125 if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
3126 return nullptr;
3127 if (OperatorDelete)
3128 return OperatorDelete;
3129
3130 // If there's no class-specific operator delete, look up the global
3131 // non-array delete.
3132 return FindUsualDeallocationFunction(
3133 Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)),
3134 Name);
3135 }
3136
FindDeallocationFunction(SourceLocation StartLoc,CXXRecordDecl * RD,DeclarationName Name,FunctionDecl * & Operator,bool Diagnose)3137 bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
3138 DeclarationName Name,
3139 FunctionDecl *&Operator, bool Diagnose) {
3140 LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
3141 // Try to find operator delete/operator delete[] in class scope.
3142 LookupQualifiedName(Found, RD);
3143
3144 if (Found.isAmbiguous())
3145 return true;
3146
3147 Found.suppressDiagnostics();
3148
3149 bool Overaligned = hasNewExtendedAlignment(*this, Context.getRecordType(RD));
3150
3151 // C++17 [expr.delete]p10:
3152 // If the deallocation functions have class scope, the one without a
3153 // parameter of type std::size_t is selected.
3154 llvm::SmallVector<UsualDeallocFnInfo, 4> Matches;
3155 resolveDeallocationOverload(*this, Found, /*WantSize*/ false,
3156 /*WantAlign*/ Overaligned, &Matches);
3157
3158 // If we could find an overload, use it.
3159 if (Matches.size() == 1) {
3160 Operator = cast<CXXMethodDecl>(Matches[0].FD);
3161
3162 // FIXME: DiagnoseUseOfDecl?
3163 if (Operator->isDeleted()) {
3164 if (Diagnose) {
3165 Diag(StartLoc, diag::err_deleted_function_use);
3166 NoteDeletedFunction(Operator);
3167 }
3168 return true;
3169 }
3170
3171 if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
3172 Matches[0].Found, Diagnose) == AR_inaccessible)
3173 return true;
3174
3175 return false;
3176 }
3177
3178 // We found multiple suitable operators; complain about the ambiguity.
3179 // FIXME: The standard doesn't say to do this; it appears that the intent
3180 // is that this should never happen.
3181 if (!Matches.empty()) {
3182 if (Diagnose) {
3183 Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
3184 << Name << RD;
3185 for (auto &Match : Matches)
3186 Diag(Match.FD->getLocation(), diag::note_member_declared_here) << Name;
3187 }
3188 return true;
3189 }
3190
3191 // We did find operator delete/operator delete[] declarations, but
3192 // none of them were suitable.
3193 if (!Found.empty()) {
3194 if (Diagnose) {
3195 Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
3196 << Name << RD;
3197
3198 for (NamedDecl *D : Found)
3199 Diag(D->getUnderlyingDecl()->getLocation(),
3200 diag::note_member_declared_here) << Name;
3201 }
3202 return true;
3203 }
3204
3205 Operator = nullptr;
3206 return false;
3207 }
3208
3209 namespace {
3210 /// Checks whether delete-expression, and new-expression used for
3211 /// initializing deletee have the same array form.
3212 class MismatchingNewDeleteDetector {
3213 public:
3214 enum MismatchResult {
3215 /// Indicates that there is no mismatch or a mismatch cannot be proven.
3216 NoMismatch,
3217 /// Indicates that variable is initialized with mismatching form of \a new.
3218 VarInitMismatches,
3219 /// Indicates that member is initialized with mismatching form of \a new.
3220 MemberInitMismatches,
3221 /// Indicates that 1 or more constructors' definitions could not been
3222 /// analyzed, and they will be checked again at the end of translation unit.
3223 AnalyzeLater
3224 };
3225
3226 /// \param EndOfTU True, if this is the final analysis at the end of
3227 /// translation unit. False, if this is the initial analysis at the point
3228 /// delete-expression was encountered.
MismatchingNewDeleteDetector(bool EndOfTU)3229 explicit MismatchingNewDeleteDetector(bool EndOfTU)
3230 : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU),
3231 HasUndefinedConstructors(false) {}
3232
3233 /// Checks whether pointee of a delete-expression is initialized with
3234 /// matching form of new-expression.
3235 ///
3236 /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the
3237 /// point where delete-expression is encountered, then a warning will be
3238 /// issued immediately. If return value is \c AnalyzeLater at the point where
3239 /// delete-expression is seen, then member will be analyzed at the end of
3240 /// translation unit. \c AnalyzeLater is returned iff at least one constructor
3241 /// couldn't be analyzed. If at least one constructor initializes the member
3242 /// with matching type of new, the return value is \c NoMismatch.
3243 MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE);
3244 /// Analyzes a class member.
3245 /// \param Field Class member to analyze.
3246 /// \param DeleteWasArrayForm Array form-ness of the delete-expression used
3247 /// for deleting the \p Field.
3248 MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm);
3249 FieldDecl *Field;
3250 /// List of mismatching new-expressions used for initialization of the pointee
3251 llvm::SmallVector<const CXXNewExpr *, 4> NewExprs;
3252 /// Indicates whether delete-expression was in array form.
3253 bool IsArrayForm;
3254
3255 private:
3256 const bool EndOfTU;
3257 /// Indicates that there is at least one constructor without body.
3258 bool HasUndefinedConstructors;
3259 /// Returns \c CXXNewExpr from given initialization expression.
3260 /// \param E Expression used for initializing pointee in delete-expression.
3261 /// E can be a single-element \c InitListExpr consisting of new-expression.
3262 const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E);
3263 /// Returns whether member is initialized with mismatching form of
3264 /// \c new either by the member initializer or in-class initialization.
3265 ///
3266 /// If bodies of all constructors are not visible at the end of translation
3267 /// unit or at least one constructor initializes member with the matching
3268 /// form of \c new, mismatch cannot be proven, and this function will return
3269 /// \c NoMismatch.
3270 MismatchResult analyzeMemberExpr(const MemberExpr *ME);
3271 /// Returns whether variable is initialized with mismatching form of
3272 /// \c new.
3273 ///
3274 /// If variable is initialized with matching form of \c new or variable is not
3275 /// initialized with a \c new expression, this function will return true.
3276 /// If variable is initialized with mismatching form of \c new, returns false.
3277 /// \param D Variable to analyze.
3278 bool hasMatchingVarInit(const DeclRefExpr *D);
3279 /// Checks whether the constructor initializes pointee with mismatching
3280 /// form of \c new.
3281 ///
3282 /// Returns true, if member is initialized with matching form of \c new in
3283 /// member initializer list. Returns false, if member is initialized with the
3284 /// matching form of \c new in this constructor's initializer or given
3285 /// constructor isn't defined at the point where delete-expression is seen, or
3286 /// member isn't initialized by the constructor.
3287 bool hasMatchingNewInCtor(const CXXConstructorDecl *CD);
3288 /// Checks whether member is initialized with matching form of
3289 /// \c new in member initializer list.
3290 bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI);
3291 /// Checks whether member is initialized with mismatching form of \c new by
3292 /// in-class initializer.
3293 MismatchResult analyzeInClassInitializer();
3294 };
3295 }
3296
3297 MismatchingNewDeleteDetector::MismatchResult
analyzeDeleteExpr(const CXXDeleteExpr * DE)3298 MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) {
3299 NewExprs.clear();
3300 assert(DE && "Expected delete-expression");
3301 IsArrayForm = DE->isArrayForm();
3302 const Expr *E = DE->getArgument()->IgnoreParenImpCasts();
3303 if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) {
3304 return analyzeMemberExpr(ME);
3305 } else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) {
3306 if (!hasMatchingVarInit(D))
3307 return VarInitMismatches;
3308 }
3309 return NoMismatch;
3310 }
3311
3312 const CXXNewExpr *
getNewExprFromInitListOrExpr(const Expr * E)3313 MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) {
3314 assert(E != nullptr && "Expected a valid initializer expression");
3315 E = E->IgnoreParenImpCasts();
3316 if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) {
3317 if (ILE->getNumInits() == 1)
3318 E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts());
3319 }
3320
3321 return dyn_cast_or_null<const CXXNewExpr>(E);
3322 }
3323
hasMatchingNewInCtorInit(const CXXCtorInitializer * CI)3324 bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit(
3325 const CXXCtorInitializer *CI) {
3326 const CXXNewExpr *NE = nullptr;
3327 if (Field == CI->getMember() &&
3328 (NE = getNewExprFromInitListOrExpr(CI->getInit()))) {
3329 if (NE->isArray() == IsArrayForm)
3330 return true;
3331 else
3332 NewExprs.push_back(NE);
3333 }
3334 return false;
3335 }
3336
hasMatchingNewInCtor(const CXXConstructorDecl * CD)3337 bool MismatchingNewDeleteDetector::hasMatchingNewInCtor(
3338 const CXXConstructorDecl *CD) {
3339 if (CD->isImplicit())
3340 return false;
3341 const FunctionDecl *Definition = CD;
3342 if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) {
3343 HasUndefinedConstructors = true;
3344 return EndOfTU;
3345 }
3346 for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) {
3347 if (hasMatchingNewInCtorInit(CI))
3348 return true;
3349 }
3350 return false;
3351 }
3352
3353 MismatchingNewDeleteDetector::MismatchResult
analyzeInClassInitializer()3354 MismatchingNewDeleteDetector::analyzeInClassInitializer() {
3355 assert(Field != nullptr && "This should be called only for members");
3356 const Expr *InitExpr = Field->getInClassInitializer();
3357 if (!InitExpr)
3358 return EndOfTU ? NoMismatch : AnalyzeLater;
3359 if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) {
3360 if (NE->isArray() != IsArrayForm) {
3361 NewExprs.push_back(NE);
3362 return MemberInitMismatches;
3363 }
3364 }
3365 return NoMismatch;
3366 }
3367
3368 MismatchingNewDeleteDetector::MismatchResult
analyzeField(FieldDecl * Field,bool DeleteWasArrayForm)3369 MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field,
3370 bool DeleteWasArrayForm) {
3371 assert(Field != nullptr && "Analysis requires a valid class member.");
3372 this->Field = Field;
3373 IsArrayForm = DeleteWasArrayForm;
3374 const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent());
3375 for (const auto *CD : RD->ctors()) {
3376 if (hasMatchingNewInCtor(CD))
3377 return NoMismatch;
3378 }
3379 if (HasUndefinedConstructors)
3380 return EndOfTU ? NoMismatch : AnalyzeLater;
3381 if (!NewExprs.empty())
3382 return MemberInitMismatches;
3383 return Field->hasInClassInitializer() ? analyzeInClassInitializer()
3384 : NoMismatch;
3385 }
3386
3387 MismatchingNewDeleteDetector::MismatchResult
analyzeMemberExpr(const MemberExpr * ME)3388 MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) {
3389 assert(ME != nullptr && "Expected a member expression");
3390 if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3391 return analyzeField(F, IsArrayForm);
3392 return NoMismatch;
3393 }
3394
hasMatchingVarInit(const DeclRefExpr * D)3395 bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) {
3396 const CXXNewExpr *NE = nullptr;
3397 if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) {
3398 if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) &&
3399 NE->isArray() != IsArrayForm) {
3400 NewExprs.push_back(NE);
3401 }
3402 }
3403 return NewExprs.empty();
3404 }
3405
3406 static void
DiagnoseMismatchedNewDelete(Sema & SemaRef,SourceLocation DeleteLoc,const MismatchingNewDeleteDetector & Detector)3407 DiagnoseMismatchedNewDelete(Sema &SemaRef, SourceLocation DeleteLoc,
3408 const MismatchingNewDeleteDetector &Detector) {
3409 SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc);
3410 FixItHint H;
3411 if (!Detector.IsArrayForm)
3412 H = FixItHint::CreateInsertion(EndOfDelete, "[]");
3413 else {
3414 SourceLocation RSquare = Lexer::findLocationAfterToken(
3415 DeleteLoc, tok::l_square, SemaRef.getSourceManager(),
3416 SemaRef.getLangOpts(), true);
3417 if (RSquare.isValid())
3418 H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare));
3419 }
3420 SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new)
3421 << Detector.IsArrayForm << H;
3422
3423 for (const auto *NE : Detector.NewExprs)
3424 SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here)
3425 << Detector.IsArrayForm;
3426 }
3427
AnalyzeDeleteExprMismatch(const CXXDeleteExpr * DE)3428 void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) {
3429 if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation()))
3430 return;
3431 MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false);
3432 switch (Detector.analyzeDeleteExpr(DE)) {
3433 case MismatchingNewDeleteDetector::VarInitMismatches:
3434 case MismatchingNewDeleteDetector::MemberInitMismatches: {
3435 DiagnoseMismatchedNewDelete(*this, DE->getBeginLoc(), Detector);
3436 break;
3437 }
3438 case MismatchingNewDeleteDetector::AnalyzeLater: {
3439 DeleteExprs[Detector.Field].push_back(
3440 std::make_pair(DE->getBeginLoc(), DE->isArrayForm()));
3441 break;
3442 }
3443 case MismatchingNewDeleteDetector::NoMismatch:
3444 break;
3445 }
3446 }
3447
AnalyzeDeleteExprMismatch(FieldDecl * Field,SourceLocation DeleteLoc,bool DeleteWasArrayForm)3448 void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
3449 bool DeleteWasArrayForm) {
3450 MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true);
3451 switch (Detector.analyzeField(Field, DeleteWasArrayForm)) {
3452 case MismatchingNewDeleteDetector::VarInitMismatches:
3453 llvm_unreachable("This analysis should have been done for class members.");
3454 case MismatchingNewDeleteDetector::AnalyzeLater:
3455 llvm_unreachable("Analysis cannot be postponed any point beyond end of "
3456 "translation unit.");
3457 case MismatchingNewDeleteDetector::MemberInitMismatches:
3458 DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector);
3459 break;
3460 case MismatchingNewDeleteDetector::NoMismatch:
3461 break;
3462 }
3463 }
3464
3465 /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
3466 /// @code ::delete ptr; @endcode
3467 /// or
3468 /// @code delete [] ptr; @endcode
3469 ExprResult
ActOnCXXDelete(SourceLocation StartLoc,bool UseGlobal,bool ArrayForm,Expr * ExE)3470 Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
3471 bool ArrayForm, Expr *ExE) {
3472 // C++ [expr.delete]p1:
3473 // The operand shall have a pointer type, or a class type having a single
3474 // non-explicit conversion function to a pointer type. The result has type
3475 // void.
3476 //
3477 // DR599 amends "pointer type" to "pointer to object type" in both cases.
3478
3479 ExprResult Ex = ExE;
3480 FunctionDecl *OperatorDelete = nullptr;
3481 bool ArrayFormAsWritten = ArrayForm;
3482 bool UsualArrayDeleteWantsSize = false;
3483
3484 if (!Ex.get()->isTypeDependent()) {
3485 // Perform lvalue-to-rvalue cast, if needed.
3486 Ex = DefaultLvalueConversion(Ex.get());
3487 if (Ex.isInvalid())
3488 return ExprError();
3489
3490 QualType Type = Ex.get()->getType();
3491
3492 class DeleteConverter : public ContextualImplicitConverter {
3493 public:
3494 DeleteConverter() : ContextualImplicitConverter(false, true) {}
3495
3496 bool match(QualType ConvType) override {
3497 // FIXME: If we have an operator T* and an operator void*, we must pick
3498 // the operator T*.
3499 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
3500 if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
3501 return true;
3502 return false;
3503 }
3504
3505 SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
3506 QualType T) override {
3507 return S.Diag(Loc, diag::err_delete_operand) << T;
3508 }
3509
3510 SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
3511 QualType T) override {
3512 return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
3513 }
3514
3515 SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
3516 QualType T,
3517 QualType ConvTy) override {
3518 return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
3519 }
3520
3521 SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
3522 QualType ConvTy) override {
3523 return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3524 << ConvTy;
3525 }
3526
3527 SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
3528 QualType T) override {
3529 return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
3530 }
3531
3532 SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
3533 QualType ConvTy) override {
3534 return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3535 << ConvTy;
3536 }
3537
3538 SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
3539 QualType T,
3540 QualType ConvTy) override {
3541 llvm_unreachable("conversion functions are permitted");
3542 }
3543 } Converter;
3544
3545 Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
3546 if (Ex.isInvalid())
3547 return ExprError();
3548 Type = Ex.get()->getType();
3549 if (!Converter.match(Type))
3550 // FIXME: PerformContextualImplicitConversion should return ExprError
3551 // itself in this case.
3552 return ExprError();
3553
3554 QualType Pointee = Type->castAs<PointerType>()->getPointeeType();
3555 QualType PointeeElem = Context.getBaseElementType(Pointee);
3556
3557 if (Pointee.getAddressSpace() != LangAS::Default &&
3558 !getLangOpts().OpenCLCPlusPlus)
3559 return Diag(Ex.get()->getBeginLoc(),
3560 diag::err_address_space_qualified_delete)
3561 << Pointee.getUnqualifiedType()
3562 << Pointee.getQualifiers().getAddressSpaceAttributePrintValue();
3563
3564 CXXRecordDecl *PointeeRD = nullptr;
3565 if (Pointee->isVoidType() && !isSFINAEContext()) {
3566 // The C++ standard bans deleting a pointer to a non-object type, which
3567 // effectively bans deletion of "void*". However, most compilers support
3568 // this, so we treat it as a warning unless we're in a SFINAE context.
3569 Diag(StartLoc, diag::ext_delete_void_ptr_operand)
3570 << Type << Ex.get()->getSourceRange();
3571 } else if (Pointee->isFunctionType() || Pointee->isVoidType() ||
3572 Pointee->isSizelessType()) {
3573 return ExprError(Diag(StartLoc, diag::err_delete_operand)
3574 << Type << Ex.get()->getSourceRange());
3575 } else if (!Pointee->isDependentType()) {
3576 // FIXME: This can result in errors if the definition was imported from a
3577 // module but is hidden.
3578 if (!RequireCompleteType(StartLoc, Pointee,
3579 diag::warn_delete_incomplete, Ex.get())) {
3580 if (const RecordType *RT = PointeeElem->getAs<RecordType>())
3581 PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
3582 }
3583 }
3584
3585 if (Pointee->isArrayType() && !ArrayForm) {
3586 Diag(StartLoc, diag::warn_delete_array_type)
3587 << Type << Ex.get()->getSourceRange()
3588 << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]");
3589 ArrayForm = true;
3590 }
3591
3592 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
3593 ArrayForm ? OO_Array_Delete : OO_Delete);
3594
3595 if (PointeeRD) {
3596 if (!UseGlobal &&
3597 FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
3598 OperatorDelete))
3599 return ExprError();
3600
3601 // If we're allocating an array of records, check whether the
3602 // usual operator delete[] has a size_t parameter.
3603 if (ArrayForm) {
3604 // If the user specifically asked to use the global allocator,
3605 // we'll need to do the lookup into the class.
3606 if (UseGlobal)
3607 UsualArrayDeleteWantsSize =
3608 doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);
3609
3610 // Otherwise, the usual operator delete[] should be the
3611 // function we just found.
3612 else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
3613 UsualArrayDeleteWantsSize =
3614 UsualDeallocFnInfo(*this,
3615 DeclAccessPair::make(OperatorDelete, AS_public))
3616 .HasSizeT;
3617 }
3618
3619 if (!PointeeRD->hasIrrelevantDestructor())
3620 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3621 MarkFunctionReferenced(StartLoc,
3622 const_cast<CXXDestructorDecl*>(Dtor));
3623 if (DiagnoseUseOfDecl(Dtor, StartLoc))
3624 return ExprError();
3625 }
3626
3627 CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc,
3628 /*IsDelete=*/true, /*CallCanBeVirtual=*/true,
3629 /*WarnOnNonAbstractTypes=*/!ArrayForm,
3630 SourceLocation());
3631 }
3632
3633 if (!OperatorDelete) {
3634 if (getLangOpts().OpenCLCPlusPlus) {
3635 Diag(StartLoc, diag::err_openclcxx_not_supported) << "default delete";
3636 return ExprError();
3637 }
3638
3639 bool IsComplete = isCompleteType(StartLoc, Pointee);
3640 bool CanProvideSize =
3641 IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize ||
3642 Pointee.isDestructedType());
3643 bool Overaligned = hasNewExtendedAlignment(*this, Pointee);
3644
3645 // Look for a global declaration.
3646 OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize,
3647 Overaligned, DeleteName);
3648 }
3649
3650 MarkFunctionReferenced(StartLoc, OperatorDelete);
3651
3652 // Check access and ambiguity of destructor if we're going to call it.
3653 // Note that this is required even for a virtual delete.
3654 bool IsVirtualDelete = false;
3655 if (PointeeRD) {
3656 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3657 CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
3658 PDiag(diag::err_access_dtor) << PointeeElem);
3659 IsVirtualDelete = Dtor->isVirtual();
3660 }
3661 }
3662
3663 DiagnoseUseOfDecl(OperatorDelete, StartLoc);
3664
3665 // Convert the operand to the type of the first parameter of operator
3666 // delete. This is only necessary if we selected a destroying operator
3667 // delete that we are going to call (non-virtually); converting to void*
3668 // is trivial and left to AST consumers to handle.
3669 QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
3670 if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) {
3671 Qualifiers Qs = Pointee.getQualifiers();
3672 if (Qs.hasCVRQualifiers()) {
3673 // Qualifiers are irrelevant to this conversion; we're only looking
3674 // for access and ambiguity.
3675 Qs.removeCVRQualifiers();
3676 QualType Unqual = Context.getPointerType(
3677 Context.getQualifiedType(Pointee.getUnqualifiedType(), Qs));
3678 Ex = ImpCastExprToType(Ex.get(), Unqual, CK_NoOp);
3679 }
3680 Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing);
3681 if (Ex.isInvalid())
3682 return ExprError();
3683 }
3684 }
3685
3686 CXXDeleteExpr *Result = new (Context) CXXDeleteExpr(
3687 Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
3688 UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
3689 AnalyzeDeleteExprMismatch(Result);
3690 return Result;
3691 }
3692
resolveBuiltinNewDeleteOverload(Sema & S,CallExpr * TheCall,bool IsDelete,FunctionDecl * & Operator)3693 static bool resolveBuiltinNewDeleteOverload(Sema &S, CallExpr *TheCall,
3694 bool IsDelete,
3695 FunctionDecl *&Operator) {
3696
3697 DeclarationName NewName = S.Context.DeclarationNames.getCXXOperatorName(
3698 IsDelete ? OO_Delete : OO_New);
3699
3700 LookupResult R(S, NewName, TheCall->getBeginLoc(), Sema::LookupOrdinaryName);
3701 S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl());
3702 assert(!R.empty() && "implicitly declared allocation functions not found");
3703 assert(!R.isAmbiguous() && "global allocation functions are ambiguous");
3704
3705 // We do our own custom access checks below.
3706 R.suppressDiagnostics();
3707
3708 SmallVector<Expr *, 8> Args(TheCall->arg_begin(), TheCall->arg_end());
3709 OverloadCandidateSet Candidates(R.getNameLoc(),
3710 OverloadCandidateSet::CSK_Normal);
3711 for (LookupResult::iterator FnOvl = R.begin(), FnOvlEnd = R.end();
3712 FnOvl != FnOvlEnd; ++FnOvl) {
3713 // Even member operator new/delete are implicitly treated as
3714 // static, so don't use AddMemberCandidate.
3715 NamedDecl *D = (*FnOvl)->getUnderlyingDecl();
3716
3717 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
3718 S.AddTemplateOverloadCandidate(FnTemplate, FnOvl.getPair(),
3719 /*ExplicitTemplateArgs=*/nullptr, Args,
3720 Candidates,
3721 /*SuppressUserConversions=*/false);
3722 continue;
3723 }
3724
3725 FunctionDecl *Fn = cast<FunctionDecl>(D);
3726 S.AddOverloadCandidate(Fn, FnOvl.getPair(), Args, Candidates,
3727 /*SuppressUserConversions=*/false);
3728 }
3729
3730 SourceRange Range = TheCall->getSourceRange();
3731
3732 // Do the resolution.
3733 OverloadCandidateSet::iterator Best;
3734 switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
3735 case OR_Success: {
3736 // Got one!
3737 FunctionDecl *FnDecl = Best->Function;
3738 assert(R.getNamingClass() == nullptr &&
3739 "class members should not be considered");
3740
3741 if (!FnDecl->isReplaceableGlobalAllocationFunction()) {
3742 S.Diag(R.getNameLoc(), diag::err_builtin_operator_new_delete_not_usual)
3743 << (IsDelete ? 1 : 0) << Range;
3744 S.Diag(FnDecl->getLocation(), diag::note_non_usual_function_declared_here)
3745 << R.getLookupName() << FnDecl->getSourceRange();
3746 return true;
3747 }
3748
3749 Operator = FnDecl;
3750 return false;
3751 }
3752
3753 case OR_No_Viable_Function:
3754 Candidates.NoteCandidates(
3755 PartialDiagnosticAt(R.getNameLoc(),
3756 S.PDiag(diag::err_ovl_no_viable_function_in_call)
3757 << R.getLookupName() << Range),
3758 S, OCD_AllCandidates, Args);
3759 return true;
3760
3761 case OR_Ambiguous:
3762 Candidates.NoteCandidates(
3763 PartialDiagnosticAt(R.getNameLoc(),
3764 S.PDiag(diag::err_ovl_ambiguous_call)
3765 << R.getLookupName() << Range),
3766 S, OCD_AmbiguousCandidates, Args);
3767 return true;
3768
3769 case OR_Deleted: {
3770 Candidates.NoteCandidates(
3771 PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call)
3772 << R.getLookupName() << Range),
3773 S, OCD_AllCandidates, Args);
3774 return true;
3775 }
3776 }
3777 llvm_unreachable("Unreachable, bad result from BestViableFunction");
3778 }
3779
3780 ExprResult
SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult,bool IsDelete)3781 Sema::SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult,
3782 bool IsDelete) {
3783 CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
3784 if (!getLangOpts().CPlusPlus) {
3785 Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language)
3786 << (IsDelete ? "__builtin_operator_delete" : "__builtin_operator_new")
3787 << "C++";
3788 return ExprError();
3789 }
3790 // CodeGen assumes it can find the global new and delete to call,
3791 // so ensure that they are declared.
3792 DeclareGlobalNewDelete();
3793
3794 FunctionDecl *OperatorNewOrDelete = nullptr;
3795 if (resolveBuiltinNewDeleteOverload(*this, TheCall, IsDelete,
3796 OperatorNewOrDelete))
3797 return ExprError();
3798 assert(OperatorNewOrDelete && "should be found");
3799
3800 DiagnoseUseOfDecl(OperatorNewOrDelete, TheCall->getExprLoc());
3801 MarkFunctionReferenced(TheCall->getExprLoc(), OperatorNewOrDelete);
3802
3803 TheCall->setType(OperatorNewOrDelete->getReturnType());
3804 for (unsigned i = 0; i != TheCall->getNumArgs(); ++i) {
3805 QualType ParamTy = OperatorNewOrDelete->getParamDecl(i)->getType();
3806 InitializedEntity Entity =
3807 InitializedEntity::InitializeParameter(Context, ParamTy, false);
3808 ExprResult Arg = PerformCopyInitialization(
3809 Entity, TheCall->getArg(i)->getBeginLoc(), TheCall->getArg(i));
3810 if (Arg.isInvalid())
3811 return ExprError();
3812 TheCall->setArg(i, Arg.get());
3813 }
3814 auto Callee = dyn_cast<ImplicitCastExpr>(TheCall->getCallee());
3815 assert(Callee && Callee->getCastKind() == CK_BuiltinFnToFnPtr &&
3816 "Callee expected to be implicit cast to a builtin function pointer");
3817 Callee->setType(OperatorNewOrDelete->getType());
3818
3819 return TheCallResult;
3820 }
3821
CheckVirtualDtorCall(CXXDestructorDecl * dtor,SourceLocation Loc,bool IsDelete,bool CallCanBeVirtual,bool WarnOnNonAbstractTypes,SourceLocation DtorLoc)3822 void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc,
3823 bool IsDelete, bool CallCanBeVirtual,
3824 bool WarnOnNonAbstractTypes,
3825 SourceLocation DtorLoc) {
3826 if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext())
3827 return;
3828
3829 // C++ [expr.delete]p3:
3830 // In the first alternative (delete object), if the static type of the
3831 // object to be deleted is different from its dynamic type, the static
3832 // type shall be a base class of the dynamic type of the object to be
3833 // deleted and the static type shall have a virtual destructor or the
3834 // behavior is undefined.
3835 //
3836 const CXXRecordDecl *PointeeRD = dtor->getParent();
3837 // Note: a final class cannot be derived from, no issue there
3838 if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>())
3839 return;
3840
3841 // If the superclass is in a system header, there's nothing that can be done.
3842 // The `delete` (where we emit the warning) can be in a system header,
3843 // what matters for this warning is where the deleted type is defined.
3844 if (getSourceManager().isInSystemHeader(PointeeRD->getLocation()))
3845 return;
3846
3847 QualType ClassType = dtor->getThisType()->getPointeeType();
3848 if (PointeeRD->isAbstract()) {
3849 // If the class is abstract, we warn by default, because we're
3850 // sure the code has undefined behavior.
3851 Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1)
3852 << ClassType;
3853 } else if (WarnOnNonAbstractTypes) {
3854 // Otherwise, if this is not an array delete, it's a bit suspect,
3855 // but not necessarily wrong.
3856 Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1)
3857 << ClassType;
3858 }
3859 if (!IsDelete) {
3860 std::string TypeStr;
3861 ClassType.getAsStringInternal(TypeStr, getPrintingPolicy());
3862 Diag(DtorLoc, diag::note_delete_non_virtual)
3863 << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::");
3864 }
3865 }
3866
ActOnConditionVariable(Decl * ConditionVar,SourceLocation StmtLoc,ConditionKind CK)3867 Sema::ConditionResult Sema::ActOnConditionVariable(Decl *ConditionVar,
3868 SourceLocation StmtLoc,
3869 ConditionKind CK) {
3870 ExprResult E =
3871 CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK);
3872 if (E.isInvalid())
3873 return ConditionError();
3874 return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc),
3875 CK == ConditionKind::ConstexprIf);
3876 }
3877
3878 /// Check the use of the given variable as a C++ condition in an if,
3879 /// while, do-while, or switch statement.
CheckConditionVariable(VarDecl * ConditionVar,SourceLocation StmtLoc,ConditionKind CK)3880 ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar,
3881 SourceLocation StmtLoc,
3882 ConditionKind CK) {
3883 if (ConditionVar->isInvalidDecl())
3884 return ExprError();
3885
3886 QualType T = ConditionVar->getType();
3887
3888 // C++ [stmt.select]p2:
3889 // The declarator shall not specify a function or an array.
3890 if (T->isFunctionType())
3891 return ExprError(Diag(ConditionVar->getLocation(),
3892 diag::err_invalid_use_of_function_type)
3893 << ConditionVar->getSourceRange());
3894 else if (T->isArrayType())
3895 return ExprError(Diag(ConditionVar->getLocation(),
3896 diag::err_invalid_use_of_array_type)
3897 << ConditionVar->getSourceRange());
3898
3899 ExprResult Condition = BuildDeclRefExpr(
3900 ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue,
3901 ConditionVar->getLocation());
3902
3903 switch (CK) {
3904 case ConditionKind::Boolean:
3905 return CheckBooleanCondition(StmtLoc, Condition.get());
3906
3907 case ConditionKind::ConstexprIf:
3908 return CheckBooleanCondition(StmtLoc, Condition.get(), true);
3909
3910 case ConditionKind::Switch:
3911 return CheckSwitchCondition(StmtLoc, Condition.get());
3912 }
3913
3914 llvm_unreachable("unexpected condition kind");
3915 }
3916
3917 /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
CheckCXXBooleanCondition(Expr * CondExpr,bool IsConstexpr)3918 ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) {
3919 // C++11 6.4p4:
3920 // The value of a condition that is an initialized declaration in a statement
3921 // other than a switch statement is the value of the declared variable
3922 // implicitly converted to type bool. If that conversion is ill-formed, the
3923 // program is ill-formed.
3924 // The value of a condition that is an expression is the value of the
3925 // expression, implicitly converted to bool.
3926 //
3927 // C++2b 8.5.2p2
3928 // If the if statement is of the form if constexpr, the value of the condition
3929 // is contextually converted to bool and the converted expression shall be
3930 // a constant expression.
3931 //
3932
3933 ExprResult E = PerformContextuallyConvertToBool(CondExpr);
3934 if (!IsConstexpr || E.isInvalid() || E.get()->isValueDependent())
3935 return E;
3936
3937 // FIXME: Return this value to the caller so they don't need to recompute it.
3938 llvm::APSInt Cond;
3939 E = VerifyIntegerConstantExpression(
3940 E.get(), &Cond,
3941 diag::err_constexpr_if_condition_expression_is_not_constant);
3942 return E;
3943 }
3944
3945 /// Helper function to determine whether this is the (deprecated) C++
3946 /// conversion from a string literal to a pointer to non-const char or
3947 /// non-const wchar_t (for narrow and wide string literals,
3948 /// respectively).
3949 bool
IsStringLiteralToNonConstPointerConversion(Expr * From,QualType ToType)3950 Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
3951 // Look inside the implicit cast, if it exists.
3952 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
3953 From = Cast->getSubExpr();
3954
3955 // A string literal (2.13.4) that is not a wide string literal can
3956 // be converted to an rvalue of type "pointer to char"; a wide
3957 // string literal can be converted to an rvalue of type "pointer
3958 // to wchar_t" (C++ 4.2p2).
3959 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
3960 if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
3961 if (const BuiltinType *ToPointeeType
3962 = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
3963 // This conversion is considered only when there is an
3964 // explicit appropriate pointer target type (C++ 4.2p2).
3965 if (!ToPtrType->getPointeeType().hasQualifiers()) {
3966 switch (StrLit->getKind()) {
3967 case StringLiteral::UTF8:
3968 case StringLiteral::UTF16:
3969 case StringLiteral::UTF32:
3970 // We don't allow UTF literals to be implicitly converted
3971 break;
3972 case StringLiteral::Ascii:
3973 return (ToPointeeType->getKind() == BuiltinType::Char_U ||
3974 ToPointeeType->getKind() == BuiltinType::Char_S);
3975 case StringLiteral::Wide:
3976 return Context.typesAreCompatible(Context.getWideCharType(),
3977 QualType(ToPointeeType, 0));
3978 }
3979 }
3980 }
3981
3982 return false;
3983 }
3984
BuildCXXCastArgument(Sema & S,SourceLocation CastLoc,QualType Ty,CastKind Kind,CXXMethodDecl * Method,DeclAccessPair FoundDecl,bool HadMultipleCandidates,Expr * From)3985 static ExprResult BuildCXXCastArgument(Sema &S,
3986 SourceLocation CastLoc,
3987 QualType Ty,
3988 CastKind Kind,
3989 CXXMethodDecl *Method,
3990 DeclAccessPair FoundDecl,
3991 bool HadMultipleCandidates,
3992 Expr *From) {
3993 switch (Kind) {
3994 default: llvm_unreachable("Unhandled cast kind!");
3995 case CK_ConstructorConversion: {
3996 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
3997 SmallVector<Expr*, 8> ConstructorArgs;
3998
3999 if (S.RequireNonAbstractType(CastLoc, Ty,
4000 diag::err_allocation_of_abstract_type))
4001 return ExprError();
4002
4003 if (S.CompleteConstructorCall(Constructor, Ty, From, CastLoc,
4004 ConstructorArgs))
4005 return ExprError();
4006
4007 S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl,
4008 InitializedEntity::InitializeTemporary(Ty));
4009 if (S.DiagnoseUseOfDecl(Method, CastLoc))
4010 return ExprError();
4011
4012 ExprResult Result = S.BuildCXXConstructExpr(
4013 CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method),
4014 ConstructorArgs, HadMultipleCandidates,
4015 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4016 CXXConstructExpr::CK_Complete, SourceRange());
4017 if (Result.isInvalid())
4018 return ExprError();
4019
4020 return S.MaybeBindToTemporary(Result.getAs<Expr>());
4021 }
4022
4023 case CK_UserDefinedConversion: {
4024 assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");
4025
4026 S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
4027 if (S.DiagnoseUseOfDecl(Method, CastLoc))
4028 return ExprError();
4029
4030 // Create an implicit call expr that calls it.
4031 CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
4032 ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
4033 HadMultipleCandidates);
4034 if (Result.isInvalid())
4035 return ExprError();
4036 // Record usage of conversion in an implicit cast.
4037 Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
4038 CK_UserDefinedConversion, Result.get(),
4039 nullptr, Result.get()->getValueKind(),
4040 S.CurFPFeatureOverrides());
4041
4042 return S.MaybeBindToTemporary(Result.get());
4043 }
4044 }
4045 }
4046
4047 /// PerformImplicitConversion - Perform an implicit conversion of the
4048 /// expression From to the type ToType using the pre-computed implicit
4049 /// conversion sequence ICS. Returns the converted
4050 /// expression. Action is the kind of conversion we're performing,
4051 /// used in the error message.
4052 ExprResult
PerformImplicitConversion(Expr * From,QualType ToType,const ImplicitConversionSequence & ICS,AssignmentAction Action,CheckedConversionKind CCK)4053 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
4054 const ImplicitConversionSequence &ICS,
4055 AssignmentAction Action,
4056 CheckedConversionKind CCK) {
4057 // C++ [over.match.oper]p7: [...] operands of class type are converted [...]
4058 if (CCK == CCK_ForBuiltinOverloadedOp && !From->getType()->isRecordType())
4059 return From;
4060
4061 switch (ICS.getKind()) {
4062 case ImplicitConversionSequence::StandardConversion: {
4063 ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
4064 Action, CCK);
4065 if (Res.isInvalid())
4066 return ExprError();
4067 From = Res.get();
4068 break;
4069 }
4070
4071 case ImplicitConversionSequence::UserDefinedConversion: {
4072
4073 FunctionDecl *FD = ICS.UserDefined.ConversionFunction;
4074 CastKind CastKind;
4075 QualType BeforeToType;
4076 assert(FD && "no conversion function for user-defined conversion seq");
4077 if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
4078 CastKind = CK_UserDefinedConversion;
4079
4080 // If the user-defined conversion is specified by a conversion function,
4081 // the initial standard conversion sequence converts the source type to
4082 // the implicit object parameter of the conversion function.
4083 BeforeToType = Context.getTagDeclType(Conv->getParent());
4084 } else {
4085 const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
4086 CastKind = CK_ConstructorConversion;
4087 // Do no conversion if dealing with ... for the first conversion.
4088 if (!ICS.UserDefined.EllipsisConversion) {
4089 // If the user-defined conversion is specified by a constructor, the
4090 // initial standard conversion sequence converts the source type to
4091 // the type required by the argument of the constructor
4092 BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
4093 }
4094 }
4095 // Watch out for ellipsis conversion.
4096 if (!ICS.UserDefined.EllipsisConversion) {
4097 ExprResult Res =
4098 PerformImplicitConversion(From, BeforeToType,
4099 ICS.UserDefined.Before, AA_Converting,
4100 CCK);
4101 if (Res.isInvalid())
4102 return ExprError();
4103 From = Res.get();
4104 }
4105
4106 ExprResult CastArg = BuildCXXCastArgument(
4107 *this, From->getBeginLoc(), ToType.getNonReferenceType(), CastKind,
4108 cast<CXXMethodDecl>(FD), ICS.UserDefined.FoundConversionFunction,
4109 ICS.UserDefined.HadMultipleCandidates, From);
4110
4111 if (CastArg.isInvalid())
4112 return ExprError();
4113
4114 From = CastArg.get();
4115
4116 // C++ [over.match.oper]p7:
4117 // [...] the second standard conversion sequence of a user-defined
4118 // conversion sequence is not applied.
4119 if (CCK == CCK_ForBuiltinOverloadedOp)
4120 return From;
4121
4122 return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
4123 AA_Converting, CCK);
4124 }
4125
4126 case ImplicitConversionSequence::AmbiguousConversion:
4127 ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
4128 PDiag(diag::err_typecheck_ambiguous_condition)
4129 << From->getSourceRange());
4130 return ExprError();
4131
4132 case ImplicitConversionSequence::EllipsisConversion:
4133 llvm_unreachable("Cannot perform an ellipsis conversion");
4134
4135 case ImplicitConversionSequence::BadConversion:
4136 Sema::AssignConvertType ConvTy =
4137 CheckAssignmentConstraints(From->getExprLoc(), ToType, From->getType());
4138 bool Diagnosed = DiagnoseAssignmentResult(
4139 ConvTy == Compatible ? Incompatible : ConvTy, From->getExprLoc(),
4140 ToType, From->getType(), From, Action);
4141 assert(Diagnosed && "failed to diagnose bad conversion"); (void)Diagnosed;
4142 return ExprError();
4143 }
4144
4145 // Everything went well.
4146 return From;
4147 }
4148
4149 /// PerformImplicitConversion - Perform an implicit conversion of the
4150 /// expression From to the type ToType by following the standard
4151 /// conversion sequence SCS. Returns the converted
4152 /// expression. Flavor is the context in which we're performing this
4153 /// conversion, for use in error messages.
4154 ExprResult
PerformImplicitConversion(Expr * From,QualType ToType,const StandardConversionSequence & SCS,AssignmentAction Action,CheckedConversionKind CCK)4155 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
4156 const StandardConversionSequence& SCS,
4157 AssignmentAction Action,
4158 CheckedConversionKind CCK) {
4159 bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);
4160
4161 // Overall FIXME: we are recomputing too many types here and doing far too
4162 // much extra work. What this means is that we need to keep track of more
4163 // information that is computed when we try the implicit conversion initially,
4164 // so that we don't need to recompute anything here.
4165 QualType FromType = From->getType();
4166
4167 if (SCS.CopyConstructor) {
4168 // FIXME: When can ToType be a reference type?
4169 assert(!ToType->isReferenceType());
4170 if (SCS.Second == ICK_Derived_To_Base) {
4171 SmallVector<Expr*, 8> ConstructorArgs;
4172 if (CompleteConstructorCall(
4173 cast<CXXConstructorDecl>(SCS.CopyConstructor), ToType, From,
4174 /*FIXME:ConstructLoc*/ SourceLocation(), ConstructorArgs))
4175 return ExprError();
4176 return BuildCXXConstructExpr(
4177 /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
4178 SCS.FoundCopyConstructor, SCS.CopyConstructor,
4179 ConstructorArgs, /*HadMultipleCandidates*/ false,
4180 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4181 CXXConstructExpr::CK_Complete, SourceRange());
4182 }
4183 return BuildCXXConstructExpr(
4184 /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
4185 SCS.FoundCopyConstructor, SCS.CopyConstructor,
4186 From, /*HadMultipleCandidates*/ false,
4187 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4188 CXXConstructExpr::CK_Complete, SourceRange());
4189 }
4190
4191 // Resolve overloaded function references.
4192 if (Context.hasSameType(FromType, Context.OverloadTy)) {
4193 DeclAccessPair Found;
4194 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType,
4195 true, Found);
4196 if (!Fn)
4197 return ExprError();
4198
4199 if (DiagnoseUseOfDecl(Fn, From->getBeginLoc()))
4200 return ExprError();
4201
4202 From = FixOverloadedFunctionReference(From, Found, Fn);
4203 FromType = From->getType();
4204 }
4205
4206 // If we're converting to an atomic type, first convert to the corresponding
4207 // non-atomic type.
4208 QualType ToAtomicType;
4209 if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
4210 ToAtomicType = ToType;
4211 ToType = ToAtomic->getValueType();
4212 }
4213
4214 QualType InitialFromType = FromType;
4215 // Perform the first implicit conversion.
4216 switch (SCS.First) {
4217 case ICK_Identity:
4218 if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
4219 FromType = FromAtomic->getValueType().getUnqualifiedType();
4220 From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
4221 From, /*BasePath=*/nullptr, VK_PRValue,
4222 FPOptionsOverride());
4223 }
4224 break;
4225
4226 case ICK_Lvalue_To_Rvalue: {
4227 assert(From->getObjectKind() != OK_ObjCProperty);
4228 ExprResult FromRes = DefaultLvalueConversion(From);
4229 if (FromRes.isInvalid())
4230 return ExprError();
4231
4232 From = FromRes.get();
4233 FromType = From->getType();
4234 break;
4235 }
4236
4237 case ICK_Array_To_Pointer:
4238 FromType = Context.getArrayDecayedType(FromType);
4239 From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, VK_PRValue,
4240 /*BasePath=*/nullptr, CCK)
4241 .get();
4242 break;
4243
4244 case ICK_Function_To_Pointer:
4245 FromType = Context.getPointerType(FromType);
4246 From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
4247 VK_PRValue, /*BasePath=*/nullptr, CCK)
4248 .get();
4249 break;
4250
4251 default:
4252 llvm_unreachable("Improper first standard conversion");
4253 }
4254
4255 // Perform the second implicit conversion
4256 switch (SCS.Second) {
4257 case ICK_Identity:
4258 // C++ [except.spec]p5:
4259 // [For] assignment to and initialization of pointers to functions,
4260 // pointers to member functions, and references to functions: the
4261 // target entity shall allow at least the exceptions allowed by the
4262 // source value in the assignment or initialization.
4263 switch (Action) {
4264 case AA_Assigning:
4265 case AA_Initializing:
4266 // Note, function argument passing and returning are initialization.
4267 case AA_Passing:
4268 case AA_Returning:
4269 case AA_Sending:
4270 case AA_Passing_CFAudited:
4271 if (CheckExceptionSpecCompatibility(From, ToType))
4272 return ExprError();
4273 break;
4274
4275 case AA_Casting:
4276 case AA_Converting:
4277 // Casts and implicit conversions are not initialization, so are not
4278 // checked for exception specification mismatches.
4279 break;
4280 }
4281 // Nothing else to do.
4282 break;
4283
4284 case ICK_Integral_Promotion:
4285 case ICK_Integral_Conversion:
4286 if (ToType->isBooleanType()) {
4287 assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
4288 SCS.Second == ICK_Integral_Promotion &&
4289 "only enums with fixed underlying type can promote to bool");
4290 From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, VK_PRValue,
4291 /*BasePath=*/nullptr, CCK)
4292 .get();
4293 } else {
4294 From = ImpCastExprToType(From, ToType, CK_IntegralCast, VK_PRValue,
4295 /*BasePath=*/nullptr, CCK)
4296 .get();
4297 }
4298 break;
4299
4300 case ICK_Floating_Promotion:
4301 case ICK_Floating_Conversion:
4302 From = ImpCastExprToType(From, ToType, CK_FloatingCast, VK_PRValue,
4303 /*BasePath=*/nullptr, CCK)
4304 .get();
4305 break;
4306
4307 case ICK_Complex_Promotion:
4308 case ICK_Complex_Conversion: {
4309 QualType FromEl = From->getType()->castAs<ComplexType>()->getElementType();
4310 QualType ToEl = ToType->castAs<ComplexType>()->getElementType();
4311 CastKind CK;
4312 if (FromEl->isRealFloatingType()) {
4313 if (ToEl->isRealFloatingType())
4314 CK = CK_FloatingComplexCast;
4315 else
4316 CK = CK_FloatingComplexToIntegralComplex;
4317 } else if (ToEl->isRealFloatingType()) {
4318 CK = CK_IntegralComplexToFloatingComplex;
4319 } else {
4320 CK = CK_IntegralComplexCast;
4321 }
4322 From = ImpCastExprToType(From, ToType, CK, VK_PRValue, /*BasePath=*/nullptr,
4323 CCK)
4324 .get();
4325 break;
4326 }
4327
4328 case ICK_Floating_Integral:
4329 if (ToType->isRealFloatingType())
4330 From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, VK_PRValue,
4331 /*BasePath=*/nullptr, CCK)
4332 .get();
4333 else
4334 From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, VK_PRValue,
4335 /*BasePath=*/nullptr, CCK)
4336 .get();
4337 break;
4338
4339 case ICK_Compatible_Conversion:
4340 From = ImpCastExprToType(From, ToType, CK_NoOp, From->getValueKind(),
4341 /*BasePath=*/nullptr, CCK).get();
4342 break;
4343
4344 case ICK_Writeback_Conversion:
4345 case ICK_Pointer_Conversion: {
4346 if (SCS.IncompatibleObjC && Action != AA_Casting) {
4347 // Diagnose incompatible Objective-C conversions
4348 if (Action == AA_Initializing || Action == AA_Assigning)
4349 Diag(From->getBeginLoc(),
4350 diag::ext_typecheck_convert_incompatible_pointer)
4351 << ToType << From->getType() << Action << From->getSourceRange()
4352 << 0;
4353 else
4354 Diag(From->getBeginLoc(),
4355 diag::ext_typecheck_convert_incompatible_pointer)
4356 << From->getType() << ToType << Action << From->getSourceRange()
4357 << 0;
4358
4359 if (From->getType()->isObjCObjectPointerType() &&
4360 ToType->isObjCObjectPointerType())
4361 EmitRelatedResultTypeNote(From);
4362 } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() &&
4363 !CheckObjCARCUnavailableWeakConversion(ToType,
4364 From->getType())) {
4365 if (Action == AA_Initializing)
4366 Diag(From->getBeginLoc(), diag::err_arc_weak_unavailable_assign);
4367 else
4368 Diag(From->getBeginLoc(), diag::err_arc_convesion_of_weak_unavailable)
4369 << (Action == AA_Casting) << From->getType() << ToType
4370 << From->getSourceRange();
4371 }
4372
4373 // Defer address space conversion to the third conversion.
4374 QualType FromPteeType = From->getType()->getPointeeType();
4375 QualType ToPteeType = ToType->getPointeeType();
4376 QualType NewToType = ToType;
4377 if (!FromPteeType.isNull() && !ToPteeType.isNull() &&
4378 FromPteeType.getAddressSpace() != ToPteeType.getAddressSpace()) {
4379 NewToType = Context.removeAddrSpaceQualType(ToPteeType);
4380 NewToType = Context.getAddrSpaceQualType(NewToType,
4381 FromPteeType.getAddressSpace());
4382 if (ToType->isObjCObjectPointerType())
4383 NewToType = Context.getObjCObjectPointerType(NewToType);
4384 else if (ToType->isBlockPointerType())
4385 NewToType = Context.getBlockPointerType(NewToType);
4386 else
4387 NewToType = Context.getPointerType(NewToType);
4388 }
4389
4390 CastKind Kind;
4391 CXXCastPath BasePath;
4392 if (CheckPointerConversion(From, NewToType, Kind, BasePath, CStyle))
4393 return ExprError();
4394
4395 // Make sure we extend blocks if necessary.
4396 // FIXME: doing this here is really ugly.
4397 if (Kind == CK_BlockPointerToObjCPointerCast) {
4398 ExprResult E = From;
4399 (void) PrepareCastToObjCObjectPointer(E);
4400 From = E.get();
4401 }
4402 if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers())
4403 CheckObjCConversion(SourceRange(), NewToType, From, CCK);
4404 From = ImpCastExprToType(From, NewToType, Kind, VK_PRValue, &BasePath, CCK)
4405 .get();
4406 break;
4407 }
4408
4409 case ICK_Pointer_Member: {
4410 CastKind Kind;
4411 CXXCastPath BasePath;
4412 if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
4413 return ExprError();
4414 if (CheckExceptionSpecCompatibility(From, ToType))
4415 return ExprError();
4416
4417 // We may not have been able to figure out what this member pointer resolved
4418 // to up until this exact point. Attempt to lock-in it's inheritance model.
4419 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
4420 (void)isCompleteType(From->getExprLoc(), From->getType());
4421 (void)isCompleteType(From->getExprLoc(), ToType);
4422 }
4423
4424 From =
4425 ImpCastExprToType(From, ToType, Kind, VK_PRValue, &BasePath, CCK).get();
4426 break;
4427 }
4428
4429 case ICK_Boolean_Conversion:
4430 // Perform half-to-boolean conversion via float.
4431 if (From->getType()->isHalfType()) {
4432 From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
4433 FromType = Context.FloatTy;
4434 }
4435
4436 From = ImpCastExprToType(From, Context.BoolTy,
4437 ScalarTypeToBooleanCastKind(FromType), VK_PRValue,
4438 /*BasePath=*/nullptr, CCK)
4439 .get();
4440 break;
4441
4442 case ICK_Derived_To_Base: {
4443 CXXCastPath BasePath;
4444 if (CheckDerivedToBaseConversion(
4445 From->getType(), ToType.getNonReferenceType(), From->getBeginLoc(),
4446 From->getSourceRange(), &BasePath, CStyle))
4447 return ExprError();
4448
4449 From = ImpCastExprToType(From, ToType.getNonReferenceType(),
4450 CK_DerivedToBase, From->getValueKind(),
4451 &BasePath, CCK).get();
4452 break;
4453 }
4454
4455 case ICK_Vector_Conversion:
4456 From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
4457 /*BasePath=*/nullptr, CCK)
4458 .get();
4459 break;
4460
4461 case ICK_SVE_Vector_Conversion:
4462 From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
4463 /*BasePath=*/nullptr, CCK)
4464 .get();
4465 break;
4466
4467 case ICK_Vector_Splat: {
4468 // Vector splat from any arithmetic type to a vector.
4469 Expr *Elem = prepareVectorSplat(ToType, From).get();
4470 From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_PRValue,
4471 /*BasePath=*/nullptr, CCK)
4472 .get();
4473 break;
4474 }
4475
4476 case ICK_Complex_Real:
4477 // Case 1. x -> _Complex y
4478 if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
4479 QualType ElType = ToComplex->getElementType();
4480 bool isFloatingComplex = ElType->isRealFloatingType();
4481
4482 // x -> y
4483 if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
4484 // do nothing
4485 } else if (From->getType()->isRealFloatingType()) {
4486 From = ImpCastExprToType(From, ElType,
4487 isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
4488 } else {
4489 assert(From->getType()->isIntegerType());
4490 From = ImpCastExprToType(From, ElType,
4491 isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
4492 }
4493 // y -> _Complex y
4494 From = ImpCastExprToType(From, ToType,
4495 isFloatingComplex ? CK_FloatingRealToComplex
4496 : CK_IntegralRealToComplex).get();
4497
4498 // Case 2. _Complex x -> y
4499 } else {
4500 auto *FromComplex = From->getType()->castAs<ComplexType>();
4501 QualType ElType = FromComplex->getElementType();
4502 bool isFloatingComplex = ElType->isRealFloatingType();
4503
4504 // _Complex x -> x
4505 From = ImpCastExprToType(From, ElType,
4506 isFloatingComplex ? CK_FloatingComplexToReal
4507 : CK_IntegralComplexToReal,
4508 VK_PRValue, /*BasePath=*/nullptr, CCK)
4509 .get();
4510
4511 // x -> y
4512 if (Context.hasSameUnqualifiedType(ElType, ToType)) {
4513 // do nothing
4514 } else if (ToType->isRealFloatingType()) {
4515 From = ImpCastExprToType(From, ToType,
4516 isFloatingComplex ? CK_FloatingCast
4517 : CK_IntegralToFloating,
4518 VK_PRValue, /*BasePath=*/nullptr, CCK)
4519 .get();
4520 } else {
4521 assert(ToType->isIntegerType());
4522 From = ImpCastExprToType(From, ToType,
4523 isFloatingComplex ? CK_FloatingToIntegral
4524 : CK_IntegralCast,
4525 VK_PRValue, /*BasePath=*/nullptr, CCK)
4526 .get();
4527 }
4528 }
4529 break;
4530
4531 case ICK_Block_Pointer_Conversion: {
4532 LangAS AddrSpaceL =
4533 ToType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
4534 LangAS AddrSpaceR =
4535 FromType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
4536 assert(Qualifiers::isAddressSpaceSupersetOf(AddrSpaceL, AddrSpaceR) &&
4537 "Invalid cast");
4538 CastKind Kind =
4539 AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast;
4540 From = ImpCastExprToType(From, ToType.getUnqualifiedType(), Kind,
4541 VK_PRValue, /*BasePath=*/nullptr, CCK)
4542 .get();
4543 break;
4544 }
4545
4546 case ICK_TransparentUnionConversion: {
4547 ExprResult FromRes = From;
4548 Sema::AssignConvertType ConvTy =
4549 CheckTransparentUnionArgumentConstraints(ToType, FromRes);
4550 if (FromRes.isInvalid())
4551 return ExprError();
4552 From = FromRes.get();
4553 assert ((ConvTy == Sema::Compatible) &&
4554 "Improper transparent union conversion");
4555 (void)ConvTy;
4556 break;
4557 }
4558
4559 case ICK_Zero_Event_Conversion:
4560 case ICK_Zero_Queue_Conversion:
4561 From = ImpCastExprToType(From, ToType,
4562 CK_ZeroToOCLOpaqueType,
4563 From->getValueKind()).get();
4564 break;
4565
4566 case ICK_Lvalue_To_Rvalue:
4567 case ICK_Array_To_Pointer:
4568 case ICK_Function_To_Pointer:
4569 case ICK_Function_Conversion:
4570 case ICK_Qualification:
4571 case ICK_Num_Conversion_Kinds:
4572 case ICK_C_Only_Conversion:
4573 case ICK_Incompatible_Pointer_Conversion:
4574 llvm_unreachable("Improper second standard conversion");
4575 }
4576
4577 switch (SCS.Third) {
4578 case ICK_Identity:
4579 // Nothing to do.
4580 break;
4581
4582 case ICK_Function_Conversion:
4583 // If both sides are functions (or pointers/references to them), there could
4584 // be incompatible exception declarations.
4585 if (CheckExceptionSpecCompatibility(From, ToType))
4586 return ExprError();
4587
4588 From = ImpCastExprToType(From, ToType, CK_NoOp, VK_PRValue,
4589 /*BasePath=*/nullptr, CCK)
4590 .get();
4591 break;
4592
4593 case ICK_Qualification: {
4594 ExprValueKind VK = From->getValueKind();
4595 CastKind CK = CK_NoOp;
4596
4597 if (ToType->isReferenceType() &&
4598 ToType->getPointeeType().getAddressSpace() !=
4599 From->getType().getAddressSpace())
4600 CK = CK_AddressSpaceConversion;
4601
4602 if (ToType->isPointerType() &&
4603 ToType->getPointeeType().getAddressSpace() !=
4604 From->getType()->getPointeeType().getAddressSpace())
4605 CK = CK_AddressSpaceConversion;
4606
4607 From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK, VK,
4608 /*BasePath=*/nullptr, CCK)
4609 .get();
4610
4611 if (SCS.DeprecatedStringLiteralToCharPtr &&
4612 !getLangOpts().WritableStrings) {
4613 Diag(From->getBeginLoc(),
4614 getLangOpts().CPlusPlus11
4615 ? diag::ext_deprecated_string_literal_conversion
4616 : diag::warn_deprecated_string_literal_conversion)
4617 << ToType.getNonReferenceType();
4618 }
4619
4620 break;
4621 }
4622
4623 default:
4624 llvm_unreachable("Improper third standard conversion");
4625 }
4626
4627 // If this conversion sequence involved a scalar -> atomic conversion, perform
4628 // that conversion now.
4629 if (!ToAtomicType.isNull()) {
4630 assert(Context.hasSameType(
4631 ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()));
4632 From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic,
4633 VK_PRValue, nullptr, CCK)
4634 .get();
4635 }
4636
4637 // Materialize a temporary if we're implicitly converting to a reference
4638 // type. This is not required by the C++ rules but is necessary to maintain
4639 // AST invariants.
4640 if (ToType->isReferenceType() && From->isPRValue()) {
4641 ExprResult Res = TemporaryMaterializationConversion(From);
4642 if (Res.isInvalid())
4643 return ExprError();
4644 From = Res.get();
4645 }
4646
4647 // If this conversion sequence succeeded and involved implicitly converting a
4648 // _Nullable type to a _Nonnull one, complain.
4649 if (!isCast(CCK))
4650 diagnoseNullableToNonnullConversion(ToType, InitialFromType,
4651 From->getBeginLoc());
4652
4653 return From;
4654 }
4655
4656 /// Check the completeness of a type in a unary type trait.
4657 ///
4658 /// If the particular type trait requires a complete type, tries to complete
4659 /// it. If completing the type fails, a diagnostic is emitted and false
4660 /// returned. If completing the type succeeds or no completion was required,
4661 /// returns true.
CheckUnaryTypeTraitTypeCompleteness(Sema & S,TypeTrait UTT,SourceLocation Loc,QualType ArgTy)4662 static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT,
4663 SourceLocation Loc,
4664 QualType ArgTy) {
4665 // C++0x [meta.unary.prop]p3:
4666 // For all of the class templates X declared in this Clause, instantiating
4667 // that template with a template argument that is a class template
4668 // specialization may result in the implicit instantiation of the template
4669 // argument if and only if the semantics of X require that the argument
4670 // must be a complete type.
4671 // We apply this rule to all the type trait expressions used to implement
4672 // these class templates. We also try to follow any GCC documented behavior
4673 // in these expressions to ensure portability of standard libraries.
4674 switch (UTT) {
4675 default: llvm_unreachable("not a UTT");
4676 // is_complete_type somewhat obviously cannot require a complete type.
4677 case UTT_IsCompleteType:
4678 // Fall-through
4679
4680 // These traits are modeled on the type predicates in C++0x
4681 // [meta.unary.cat] and [meta.unary.comp]. They are not specified as
4682 // requiring a complete type, as whether or not they return true cannot be
4683 // impacted by the completeness of the type.
4684 case UTT_IsVoid:
4685 case UTT_IsIntegral:
4686 case UTT_IsFloatingPoint:
4687 case UTT_IsArray:
4688 case UTT_IsPointer:
4689 case UTT_IsLvalueReference:
4690 case UTT_IsRvalueReference:
4691 case UTT_IsMemberFunctionPointer:
4692 case UTT_IsMemberObjectPointer:
4693 case UTT_IsEnum:
4694 case UTT_IsUnion:
4695 case UTT_IsClass:
4696 case UTT_IsFunction:
4697 case UTT_IsReference:
4698 case UTT_IsArithmetic:
4699 case UTT_IsFundamental:
4700 case UTT_IsObject:
4701 case UTT_IsScalar:
4702 case UTT_IsCompound:
4703 case UTT_IsMemberPointer:
4704 // Fall-through
4705
4706 // These traits are modeled on type predicates in C++0x [meta.unary.prop]
4707 // which requires some of its traits to have the complete type. However,
4708 // the completeness of the type cannot impact these traits' semantics, and
4709 // so they don't require it. This matches the comments on these traits in
4710 // Table 49.
4711 case UTT_IsConst:
4712 case UTT_IsVolatile:
4713 case UTT_IsSigned:
4714 case UTT_IsUnsigned:
4715
4716 // This type trait always returns false, checking the type is moot.
4717 case UTT_IsInterfaceClass:
4718 return true;
4719
4720 // C++14 [meta.unary.prop]:
4721 // If T is a non-union class type, T shall be a complete type.
4722 case UTT_IsEmpty:
4723 case UTT_IsPolymorphic:
4724 case UTT_IsAbstract:
4725 if (const auto *RD = ArgTy->getAsCXXRecordDecl())
4726 if (!RD->isUnion())
4727 return !S.RequireCompleteType(
4728 Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4729 return true;
4730
4731 // C++14 [meta.unary.prop]:
4732 // If T is a class type, T shall be a complete type.
4733 case UTT_IsFinal:
4734 case UTT_IsSealed:
4735 if (ArgTy->getAsCXXRecordDecl())
4736 return !S.RequireCompleteType(
4737 Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4738 return true;
4739
4740 // C++1z [meta.unary.prop]:
4741 // remove_all_extents_t<T> shall be a complete type or cv void.
4742 case UTT_IsAggregate:
4743 case UTT_IsTrivial:
4744 case UTT_IsTriviallyCopyable:
4745 case UTT_IsStandardLayout:
4746 case UTT_IsPOD:
4747 case UTT_IsLiteral:
4748 // Per the GCC type traits documentation, T shall be a complete type, cv void,
4749 // or an array of unknown bound. But GCC actually imposes the same constraints
4750 // as above.
4751 case UTT_HasNothrowAssign:
4752 case UTT_HasNothrowMoveAssign:
4753 case UTT_HasNothrowConstructor:
4754 case UTT_HasNothrowCopy:
4755 case UTT_HasTrivialAssign:
4756 case UTT_HasTrivialMoveAssign:
4757 case UTT_HasTrivialDefaultConstructor:
4758 case UTT_HasTrivialMoveConstructor:
4759 case UTT_HasTrivialCopy:
4760 case UTT_HasTrivialDestructor:
4761 case UTT_HasVirtualDestructor:
4762 ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0);
4763 LLVM_FALLTHROUGH;
4764
4765 // C++1z [meta.unary.prop]:
4766 // T shall be a complete type, cv void, or an array of unknown bound.
4767 case UTT_IsDestructible:
4768 case UTT_IsNothrowDestructible:
4769 case UTT_IsTriviallyDestructible:
4770 case UTT_HasUniqueObjectRepresentations:
4771 if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType())
4772 return true;
4773
4774 return !S.RequireCompleteType(
4775 Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4776 }
4777 }
4778
HasNoThrowOperator(const RecordType * RT,OverloadedOperatorKind Op,Sema & Self,SourceLocation KeyLoc,ASTContext & C,bool (CXXRecordDecl::* HasTrivial)()const,bool (CXXRecordDecl::* HasNonTrivial)()const,bool (CXXMethodDecl::* IsDesiredOp)()const)4779 static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op,
4780 Sema &Self, SourceLocation KeyLoc, ASTContext &C,
4781 bool (CXXRecordDecl::*HasTrivial)() const,
4782 bool (CXXRecordDecl::*HasNonTrivial)() const,
4783 bool (CXXMethodDecl::*IsDesiredOp)() const)
4784 {
4785 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
4786 if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)())
4787 return true;
4788
4789 DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op);
4790 DeclarationNameInfo NameInfo(Name, KeyLoc);
4791 LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName);
4792 if (Self.LookupQualifiedName(Res, RD)) {
4793 bool FoundOperator = false;
4794 Res.suppressDiagnostics();
4795 for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end();
4796 Op != OpEnd; ++Op) {
4797 if (isa<FunctionTemplateDecl>(*Op))
4798 continue;
4799
4800 CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op);
4801 if((Operator->*IsDesiredOp)()) {
4802 FoundOperator = true;
4803 auto *CPT = Operator->getType()->castAs<FunctionProtoType>();
4804 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
4805 if (!CPT || !CPT->isNothrow())
4806 return false;
4807 }
4808 }
4809 return FoundOperator;
4810 }
4811 return false;
4812 }
4813
EvaluateUnaryTypeTrait(Sema & Self,TypeTrait UTT,SourceLocation KeyLoc,QualType T)4814 static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
4815 SourceLocation KeyLoc, QualType T) {
4816 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
4817
4818 ASTContext &C = Self.Context;
4819 switch(UTT) {
4820 default: llvm_unreachable("not a UTT");
4821 // Type trait expressions corresponding to the primary type category
4822 // predicates in C++0x [meta.unary.cat].
4823 case UTT_IsVoid:
4824 return T->isVoidType();
4825 case UTT_IsIntegral:
4826 return T->isIntegralType(C);
4827 case UTT_IsFloatingPoint:
4828 return T->isFloatingType();
4829 case UTT_IsArray:
4830 return T->isArrayType();
4831 case UTT_IsPointer:
4832 return T->isAnyPointerType();
4833 case UTT_IsLvalueReference:
4834 return T->isLValueReferenceType();
4835 case UTT_IsRvalueReference:
4836 return T->isRValueReferenceType();
4837 case UTT_IsMemberFunctionPointer:
4838 return T->isMemberFunctionPointerType();
4839 case UTT_IsMemberObjectPointer:
4840 return T->isMemberDataPointerType();
4841 case UTT_IsEnum:
4842 return T->isEnumeralType();
4843 case UTT_IsUnion:
4844 return T->isUnionType();
4845 case UTT_IsClass:
4846 return T->isClassType() || T->isStructureType() || T->isInterfaceType();
4847 case UTT_IsFunction:
4848 return T->isFunctionType();
4849
4850 // Type trait expressions which correspond to the convenient composition
4851 // predicates in C++0x [meta.unary.comp].
4852 case UTT_IsReference:
4853 return T->isReferenceType();
4854 case UTT_IsArithmetic:
4855 return T->isArithmeticType() && !T->isEnumeralType();
4856 case UTT_IsFundamental:
4857 return T->isFundamentalType();
4858 case UTT_IsObject:
4859 return T->isObjectType();
4860 case UTT_IsScalar:
4861 // Note: semantic analysis depends on Objective-C lifetime types to be
4862 // considered scalar types. However, such types do not actually behave
4863 // like scalar types at run time (since they may require retain/release
4864 // operations), so we report them as non-scalar.
4865 if (T->isObjCLifetimeType()) {
4866 switch (T.getObjCLifetime()) {
4867 case Qualifiers::OCL_None:
4868 case Qualifiers::OCL_ExplicitNone:
4869 return true;
4870
4871 case Qualifiers::OCL_Strong:
4872 case Qualifiers::OCL_Weak:
4873 case Qualifiers::OCL_Autoreleasing:
4874 return false;
4875 }
4876 }
4877
4878 return T->isScalarType();
4879 case UTT_IsCompound:
4880 return T->isCompoundType();
4881 case UTT_IsMemberPointer:
4882 return T->isMemberPointerType();
4883
4884 // Type trait expressions which correspond to the type property predicates
4885 // in C++0x [meta.unary.prop].
4886 case UTT_IsConst:
4887 return T.isConstQualified();
4888 case UTT_IsVolatile:
4889 return T.isVolatileQualified();
4890 case UTT_IsTrivial:
4891 return T.isTrivialType(C);
4892 case UTT_IsTriviallyCopyable:
4893 return T.isTriviallyCopyableType(C);
4894 case UTT_IsStandardLayout:
4895 return T->isStandardLayoutType();
4896 case UTT_IsPOD:
4897 return T.isPODType(C);
4898 case UTT_IsLiteral:
4899 return T->isLiteralType(C);
4900 case UTT_IsEmpty:
4901 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4902 return !RD->isUnion() && RD->isEmpty();
4903 return false;
4904 case UTT_IsPolymorphic:
4905 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4906 return !RD->isUnion() && RD->isPolymorphic();
4907 return false;
4908 case UTT_IsAbstract:
4909 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4910 return !RD->isUnion() && RD->isAbstract();
4911 return false;
4912 case UTT_IsAggregate:
4913 // Report vector extensions and complex types as aggregates because they
4914 // support aggregate initialization. GCC mirrors this behavior for vectors
4915 // but not _Complex.
4916 return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() ||
4917 T->isAnyComplexType();
4918 // __is_interface_class only returns true when CL is invoked in /CLR mode and
4919 // even then only when it is used with the 'interface struct ...' syntax
4920 // Clang doesn't support /CLR which makes this type trait moot.
4921 case UTT_IsInterfaceClass:
4922 return false;
4923 case UTT_IsFinal:
4924 case UTT_IsSealed:
4925 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4926 return RD->hasAttr<FinalAttr>();
4927 return false;
4928 case UTT_IsSigned:
4929 // Enum types should always return false.
4930 // Floating points should always return true.
4931 return T->isFloatingType() ||
4932 (T->isSignedIntegerType() && !T->isEnumeralType());
4933 case UTT_IsUnsigned:
4934 // Enum types should always return false.
4935 return T->isUnsignedIntegerType() && !T->isEnumeralType();
4936
4937 // Type trait expressions which query classes regarding their construction,
4938 // destruction, and copying. Rather than being based directly on the
4939 // related type predicates in the standard, they are specified by both
4940 // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those
4941 // specifications.
4942 //
4943 // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html
4944 // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
4945 //
4946 // Note that these builtins do not behave as documented in g++: if a class
4947 // has both a trivial and a non-trivial special member of a particular kind,
4948 // they return false! For now, we emulate this behavior.
4949 // FIXME: This appears to be a g++ bug: more complex cases reveal that it
4950 // does not correctly compute triviality in the presence of multiple special
4951 // members of the same kind. Revisit this once the g++ bug is fixed.
4952 case UTT_HasTrivialDefaultConstructor:
4953 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4954 // If __is_pod (type) is true then the trait is true, else if type is
4955 // a cv class or union type (or array thereof) with a trivial default
4956 // constructor ([class.ctor]) then the trait is true, else it is false.
4957 if (T.isPODType(C))
4958 return true;
4959 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
4960 return RD->hasTrivialDefaultConstructor() &&
4961 !RD->hasNonTrivialDefaultConstructor();
4962 return false;
4963 case UTT_HasTrivialMoveConstructor:
4964 // This trait is implemented by MSVC 2012 and needed to parse the
4965 // standard library headers. Specifically this is used as the logic
4966 // behind std::is_trivially_move_constructible (20.9.4.3).
4967 if (T.isPODType(C))
4968 return true;
4969 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
4970 return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor();
4971 return false;
4972 case UTT_HasTrivialCopy:
4973 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4974 // If __is_pod (type) is true or type is a reference type then
4975 // the trait is true, else if type is a cv class or union type
4976 // with a trivial copy constructor ([class.copy]) then the trait
4977 // is true, else it is false.
4978 if (T.isPODType(C) || T->isReferenceType())
4979 return true;
4980 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4981 return RD->hasTrivialCopyConstructor() &&
4982 !RD->hasNonTrivialCopyConstructor();
4983 return false;
4984 case UTT_HasTrivialMoveAssign:
4985 // This trait is implemented by MSVC 2012 and needed to parse the
4986 // standard library headers. Specifically it is used as the logic
4987 // behind std::is_trivially_move_assignable (20.9.4.3)
4988 if (T.isPODType(C))
4989 return true;
4990 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
4991 return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment();
4992 return false;
4993 case UTT_HasTrivialAssign:
4994 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4995 // If type is const qualified or is a reference type then the
4996 // trait is false. Otherwise if __is_pod (type) is true then the
4997 // trait is true, else if type is a cv class or union type with
4998 // a trivial copy assignment ([class.copy]) then the trait is
4999 // true, else it is false.
5000 // Note: the const and reference restrictions are interesting,
5001 // given that const and reference members don't prevent a class
5002 // from having a trivial copy assignment operator (but do cause
5003 // errors if the copy assignment operator is actually used, q.v.
5004 // [class.copy]p12).
5005
5006 if (T.isConstQualified())
5007 return false;
5008 if (T.isPODType(C))
5009 return true;
5010 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5011 return RD->hasTrivialCopyAssignment() &&
5012 !RD->hasNonTrivialCopyAssignment();
5013 return false;
5014 case UTT_IsDestructible:
5015 case UTT_IsTriviallyDestructible:
5016 case UTT_IsNothrowDestructible:
5017 // C++14 [meta.unary.prop]:
5018 // For reference types, is_destructible<T>::value is true.
5019 if (T->isReferenceType())
5020 return true;
5021
5022 // Objective-C++ ARC: autorelease types don't require destruction.
5023 if (T->isObjCLifetimeType() &&
5024 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing)
5025 return true;
5026
5027 // C++14 [meta.unary.prop]:
5028 // For incomplete types and function types, is_destructible<T>::value is
5029 // false.
5030 if (T->isIncompleteType() || T->isFunctionType())
5031 return false;
5032
5033 // A type that requires destruction (via a non-trivial destructor or ARC
5034 // lifetime semantics) is not trivially-destructible.
5035 if (UTT == UTT_IsTriviallyDestructible && T.isDestructedType())
5036 return false;
5037
5038 // C++14 [meta.unary.prop]:
5039 // For object types and given U equal to remove_all_extents_t<T>, if the
5040 // expression std::declval<U&>().~U() is well-formed when treated as an
5041 // unevaluated operand (Clause 5), then is_destructible<T>::value is true
5042 if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
5043 CXXDestructorDecl *Destructor = Self.LookupDestructor(RD);
5044 if (!Destructor)
5045 return false;
5046 // C++14 [dcl.fct.def.delete]p2:
5047 // A program that refers to a deleted function implicitly or
5048 // explicitly, other than to declare it, is ill-formed.
5049 if (Destructor->isDeleted())
5050 return false;
5051 if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public)
5052 return false;
5053 if (UTT == UTT_IsNothrowDestructible) {
5054 auto *CPT = Destructor->getType()->castAs<FunctionProtoType>();
5055 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5056 if (!CPT || !CPT->isNothrow())
5057 return false;
5058 }
5059 }
5060 return true;
5061
5062 case UTT_HasTrivialDestructor:
5063 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
5064 // If __is_pod (type) is true or type is a reference type
5065 // then the trait is true, else if type is a cv class or union
5066 // type (or array thereof) with a trivial destructor
5067 // ([class.dtor]) then the trait is true, else it is
5068 // false.
5069 if (T.isPODType(C) || T->isReferenceType())
5070 return true;
5071
5072 // Objective-C++ ARC: autorelease types don't require destruction.
5073 if (T->isObjCLifetimeType() &&
5074 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing)
5075 return true;
5076
5077 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5078 return RD->hasTrivialDestructor();
5079 return false;
5080 // TODO: Propagate nothrowness for implicitly declared special members.
5081 case UTT_HasNothrowAssign:
5082 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5083 // If type is const qualified or is a reference type then the
5084 // trait is false. Otherwise if __has_trivial_assign (type)
5085 // is true then the trait is true, else if type is a cv class
5086 // or union type with copy assignment operators that are known
5087 // not to throw an exception then the trait is true, else it is
5088 // false.
5089 if (C.getBaseElementType(T).isConstQualified())
5090 return false;
5091 if (T->isReferenceType())
5092 return false;
5093 if (T.isPODType(C) || T->isObjCLifetimeType())
5094 return true;
5095
5096 if (const RecordType *RT = T->getAs<RecordType>())
5097 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
5098 &CXXRecordDecl::hasTrivialCopyAssignment,
5099 &CXXRecordDecl::hasNonTrivialCopyAssignment,
5100 &CXXMethodDecl::isCopyAssignmentOperator);
5101 return false;
5102 case UTT_HasNothrowMoveAssign:
5103 // This trait is implemented by MSVC 2012 and needed to parse the
5104 // standard library headers. Specifically this is used as the logic
5105 // behind std::is_nothrow_move_assignable (20.9.4.3).
5106 if (T.isPODType(C))
5107 return true;
5108
5109 if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>())
5110 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
5111 &CXXRecordDecl::hasTrivialMoveAssignment,
5112 &CXXRecordDecl::hasNonTrivialMoveAssignment,
5113 &CXXMethodDecl::isMoveAssignmentOperator);
5114 return false;
5115 case UTT_HasNothrowCopy:
5116 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5117 // If __has_trivial_copy (type) is true then the trait is true, else
5118 // if type is a cv class or union type with copy constructors that are
5119 // known not to throw an exception then the trait is true, else it is
5120 // false.
5121 if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType())
5122 return true;
5123 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
5124 if (RD->hasTrivialCopyConstructor() &&
5125 !RD->hasNonTrivialCopyConstructor())
5126 return true;
5127
5128 bool FoundConstructor = false;
5129 unsigned FoundTQs;
5130 for (const auto *ND : Self.LookupConstructors(RD)) {
5131 // A template constructor is never a copy constructor.
5132 // FIXME: However, it may actually be selected at the actual overload
5133 // resolution point.
5134 if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
5135 continue;
5136 // UsingDecl itself is not a constructor
5137 if (isa<UsingDecl>(ND))
5138 continue;
5139 auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
5140 if (Constructor->isCopyConstructor(FoundTQs)) {
5141 FoundConstructor = true;
5142 auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
5143 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5144 if (!CPT)
5145 return false;
5146 // TODO: check whether evaluating default arguments can throw.
5147 // For now, we'll be conservative and assume that they can throw.
5148 if (!CPT->isNothrow() || CPT->getNumParams() > 1)
5149 return false;
5150 }
5151 }
5152
5153 return FoundConstructor;
5154 }
5155 return false;
5156 case UTT_HasNothrowConstructor:
5157 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
5158 // If __has_trivial_constructor (type) is true then the trait is
5159 // true, else if type is a cv class or union type (or array
5160 // thereof) with a default constructor that is known not to
5161 // throw an exception then the trait is true, else it is false.
5162 if (T.isPODType(C) || T->isObjCLifetimeType())
5163 return true;
5164 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
5165 if (RD->hasTrivialDefaultConstructor() &&
5166 !RD->hasNonTrivialDefaultConstructor())
5167 return true;
5168
5169 bool FoundConstructor = false;
5170 for (const auto *ND : Self.LookupConstructors(RD)) {
5171 // FIXME: In C++0x, a constructor template can be a default constructor.
5172 if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
5173 continue;
5174 // UsingDecl itself is not a constructor
5175 if (isa<UsingDecl>(ND))
5176 continue;
5177 auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
5178 if (Constructor->isDefaultConstructor()) {
5179 FoundConstructor = true;
5180 auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
5181 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5182 if (!CPT)
5183 return false;
5184 // FIXME: check whether evaluating default arguments can throw.
5185 // For now, we'll be conservative and assume that they can throw.
5186 if (!CPT->isNothrow() || CPT->getNumParams() > 0)
5187 return false;
5188 }
5189 }
5190 return FoundConstructor;
5191 }
5192 return false;
5193 case UTT_HasVirtualDestructor:
5194 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5195 // If type is a class type with a virtual destructor ([class.dtor])
5196 // then the trait is true, else it is false.
5197 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5198 if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD))
5199 return Destructor->isVirtual();
5200 return false;
5201
5202 // These type trait expressions are modeled on the specifications for the
5203 // Embarcadero C++0x type trait functions:
5204 // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
5205 case UTT_IsCompleteType:
5206 // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_):
5207 // Returns True if and only if T is a complete type at the point of the
5208 // function call.
5209 return !T->isIncompleteType();
5210 case UTT_HasUniqueObjectRepresentations:
5211 return C.hasUniqueObjectRepresentations(T);
5212 }
5213 }
5214
5215 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
5216 QualType RhsT, SourceLocation KeyLoc);
5217
evaluateTypeTrait(Sema & S,TypeTrait Kind,SourceLocation KWLoc,ArrayRef<TypeSourceInfo * > Args,SourceLocation RParenLoc)5218 static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc,
5219 ArrayRef<TypeSourceInfo *> Args,
5220 SourceLocation RParenLoc) {
5221 if (Kind <= UTT_Last)
5222 return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType());
5223
5224 // Evaluate BTT_ReferenceBindsToTemporary alongside the IsConstructible
5225 // traits to avoid duplication.
5226 if (Kind <= BTT_Last && Kind != BTT_ReferenceBindsToTemporary)
5227 return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(),
5228 Args[1]->getType(), RParenLoc);
5229
5230 switch (Kind) {
5231 case clang::BTT_ReferenceBindsToTemporary:
5232 case clang::TT_IsConstructible:
5233 case clang::TT_IsNothrowConstructible:
5234 case clang::TT_IsTriviallyConstructible: {
5235 // C++11 [meta.unary.prop]:
5236 // is_trivially_constructible is defined as:
5237 //
5238 // is_constructible<T, Args...>::value is true and the variable
5239 // definition for is_constructible, as defined below, is known to call
5240 // no operation that is not trivial.
5241 //
5242 // The predicate condition for a template specialization
5243 // is_constructible<T, Args...> shall be satisfied if and only if the
5244 // following variable definition would be well-formed for some invented
5245 // variable t:
5246 //
5247 // T t(create<Args>()...);
5248 assert(!Args.empty());
5249
5250 // Precondition: T and all types in the parameter pack Args shall be
5251 // complete types, (possibly cv-qualified) void, or arrays of
5252 // unknown bound.
5253 for (const auto *TSI : Args) {
5254 QualType ArgTy = TSI->getType();
5255 if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType())
5256 continue;
5257
5258 if (S.RequireCompleteType(KWLoc, ArgTy,
5259 diag::err_incomplete_type_used_in_type_trait_expr))
5260 return false;
5261 }
5262
5263 // Make sure the first argument is not incomplete nor a function type.
5264 QualType T = Args[0]->getType();
5265 if (T->isIncompleteType() || T->isFunctionType())
5266 return false;
5267
5268 // Make sure the first argument is not an abstract type.
5269 CXXRecordDecl *RD = T->getAsCXXRecordDecl();
5270 if (RD && RD->isAbstract())
5271 return false;
5272
5273 llvm::BumpPtrAllocator OpaqueExprAllocator;
5274 SmallVector<Expr *, 2> ArgExprs;
5275 ArgExprs.reserve(Args.size() - 1);
5276 for (unsigned I = 1, N = Args.size(); I != N; ++I) {
5277 QualType ArgTy = Args[I]->getType();
5278 if (ArgTy->isObjectType() || ArgTy->isFunctionType())
5279 ArgTy = S.Context.getRValueReferenceType(ArgTy);
5280 ArgExprs.push_back(
5281 new (OpaqueExprAllocator.Allocate<OpaqueValueExpr>())
5282 OpaqueValueExpr(Args[I]->getTypeLoc().getBeginLoc(),
5283 ArgTy.getNonLValueExprType(S.Context),
5284 Expr::getValueKindForType(ArgTy)));
5285 }
5286
5287 // Perform the initialization in an unevaluated context within a SFINAE
5288 // trap at translation unit scope.
5289 EnterExpressionEvaluationContext Unevaluated(
5290 S, Sema::ExpressionEvaluationContext::Unevaluated);
5291 Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
5292 Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl());
5293 InitializedEntity To(
5294 InitializedEntity::InitializeTemporary(S.Context, Args[0]));
5295 InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc,
5296 RParenLoc));
5297 InitializationSequence Init(S, To, InitKind, ArgExprs);
5298 if (Init.Failed())
5299 return false;
5300
5301 ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs);
5302 if (Result.isInvalid() || SFINAE.hasErrorOccurred())
5303 return false;
5304
5305 if (Kind == clang::TT_IsConstructible)
5306 return true;
5307
5308 if (Kind == clang::BTT_ReferenceBindsToTemporary) {
5309 if (!T->isReferenceType())
5310 return false;
5311
5312 return !Init.isDirectReferenceBinding();
5313 }
5314
5315 if (Kind == clang::TT_IsNothrowConstructible)
5316 return S.canThrow(Result.get()) == CT_Cannot;
5317
5318 if (Kind == clang::TT_IsTriviallyConstructible) {
5319 // Under Objective-C ARC and Weak, if the destination has non-trivial
5320 // Objective-C lifetime, this is a non-trivial construction.
5321 if (T.getNonReferenceType().hasNonTrivialObjCLifetime())
5322 return false;
5323
5324 // The initialization succeeded; now make sure there are no non-trivial
5325 // calls.
5326 return !Result.get()->hasNonTrivialCall(S.Context);
5327 }
5328
5329 llvm_unreachable("unhandled type trait");
5330 return false;
5331 }
5332 default: llvm_unreachable("not a TT");
5333 }
5334
5335 return false;
5336 }
5337
BuildTypeTrait(TypeTrait Kind,SourceLocation KWLoc,ArrayRef<TypeSourceInfo * > Args,SourceLocation RParenLoc)5338 ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
5339 ArrayRef<TypeSourceInfo *> Args,
5340 SourceLocation RParenLoc) {
5341 QualType ResultType = Context.getLogicalOperationType();
5342
5343 if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness(
5344 *this, Kind, KWLoc, Args[0]->getType()))
5345 return ExprError();
5346
5347 bool Dependent = false;
5348 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
5349 if (Args[I]->getType()->isDependentType()) {
5350 Dependent = true;
5351 break;
5352 }
5353 }
5354
5355 bool Result = false;
5356 if (!Dependent)
5357 Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc);
5358
5359 return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args,
5360 RParenLoc, Result);
5361 }
5362
ActOnTypeTrait(TypeTrait Kind,SourceLocation KWLoc,ArrayRef<ParsedType> Args,SourceLocation RParenLoc)5363 ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
5364 ArrayRef<ParsedType> Args,
5365 SourceLocation RParenLoc) {
5366 SmallVector<TypeSourceInfo *, 4> ConvertedArgs;
5367 ConvertedArgs.reserve(Args.size());
5368
5369 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
5370 TypeSourceInfo *TInfo;
5371 QualType T = GetTypeFromParser(Args[I], &TInfo);
5372 if (!TInfo)
5373 TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc);
5374
5375 ConvertedArgs.push_back(TInfo);
5376 }
5377
5378 return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc);
5379 }
5380
EvaluateBinaryTypeTrait(Sema & Self,TypeTrait BTT,QualType LhsT,QualType RhsT,SourceLocation KeyLoc)5381 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
5382 QualType RhsT, SourceLocation KeyLoc) {
5383 assert(!LhsT->isDependentType() && !RhsT->isDependentType() &&
5384 "Cannot evaluate traits of dependent types");
5385
5386 switch(BTT) {
5387 case BTT_IsBaseOf: {
5388 // C++0x [meta.rel]p2
5389 // Base is a base class of Derived without regard to cv-qualifiers or
5390 // Base and Derived are not unions and name the same class type without
5391 // regard to cv-qualifiers.
5392
5393 const RecordType *lhsRecord = LhsT->getAs<RecordType>();
5394 const RecordType *rhsRecord = RhsT->getAs<RecordType>();
5395 if (!rhsRecord || !lhsRecord) {
5396 const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>();
5397 const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>();
5398 if (!LHSObjTy || !RHSObjTy)
5399 return false;
5400
5401 ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface();
5402 ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface();
5403 if (!BaseInterface || !DerivedInterface)
5404 return false;
5405
5406 if (Self.RequireCompleteType(
5407 KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr))
5408 return false;
5409
5410 return BaseInterface->isSuperClassOf(DerivedInterface);
5411 }
5412
5413 assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)
5414 == (lhsRecord == rhsRecord));
5415
5416 // Unions are never base classes, and never have base classes.
5417 // It doesn't matter if they are complete or not. See PR#41843
5418 if (lhsRecord && lhsRecord->getDecl()->isUnion())
5419 return false;
5420 if (rhsRecord && rhsRecord->getDecl()->isUnion())
5421 return false;
5422
5423 if (lhsRecord == rhsRecord)
5424 return true;
5425
5426 // C++0x [meta.rel]p2:
5427 // If Base and Derived are class types and are different types
5428 // (ignoring possible cv-qualifiers) then Derived shall be a
5429 // complete type.
5430 if (Self.RequireCompleteType(KeyLoc, RhsT,
5431 diag::err_incomplete_type_used_in_type_trait_expr))
5432 return false;
5433
5434 return cast<CXXRecordDecl>(rhsRecord->getDecl())
5435 ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl()));
5436 }
5437 case BTT_IsSame:
5438 return Self.Context.hasSameType(LhsT, RhsT);
5439 case BTT_TypeCompatible: {
5440 // GCC ignores cv-qualifiers on arrays for this builtin.
5441 Qualifiers LhsQuals, RhsQuals;
5442 QualType Lhs = Self.getASTContext().getUnqualifiedArrayType(LhsT, LhsQuals);
5443 QualType Rhs = Self.getASTContext().getUnqualifiedArrayType(RhsT, RhsQuals);
5444 return Self.Context.typesAreCompatible(Lhs, Rhs);
5445 }
5446 case BTT_IsConvertible:
5447 case BTT_IsConvertibleTo: {
5448 // C++0x [meta.rel]p4:
5449 // Given the following function prototype:
5450 //
5451 // template <class T>
5452 // typename add_rvalue_reference<T>::type create();
5453 //
5454 // the predicate condition for a template specialization
5455 // is_convertible<From, To> shall be satisfied if and only if
5456 // the return expression in the following code would be
5457 // well-formed, including any implicit conversions to the return
5458 // type of the function:
5459 //
5460 // To test() {
5461 // return create<From>();
5462 // }
5463 //
5464 // Access checking is performed as if in a context unrelated to To and
5465 // From. Only the validity of the immediate context of the expression
5466 // of the return-statement (including conversions to the return type)
5467 // is considered.
5468 //
5469 // We model the initialization as a copy-initialization of a temporary
5470 // of the appropriate type, which for this expression is identical to the
5471 // return statement (since NRVO doesn't apply).
5472
5473 // Functions aren't allowed to return function or array types.
5474 if (RhsT->isFunctionType() || RhsT->isArrayType())
5475 return false;
5476
5477 // A return statement in a void function must have void type.
5478 if (RhsT->isVoidType())
5479 return LhsT->isVoidType();
5480
5481 // A function definition requires a complete, non-abstract return type.
5482 if (!Self.isCompleteType(KeyLoc, RhsT) || Self.isAbstractType(KeyLoc, RhsT))
5483 return false;
5484
5485 // Compute the result of add_rvalue_reference.
5486 if (LhsT->isObjectType() || LhsT->isFunctionType())
5487 LhsT = Self.Context.getRValueReferenceType(LhsT);
5488
5489 // Build a fake source and destination for initialization.
5490 InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT));
5491 OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
5492 Expr::getValueKindForType(LhsT));
5493 Expr *FromPtr = &From;
5494 InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc,
5495 SourceLocation()));
5496
5497 // Perform the initialization in an unevaluated context within a SFINAE
5498 // trap at translation unit scope.
5499 EnterExpressionEvaluationContext Unevaluated(
5500 Self, Sema::ExpressionEvaluationContext::Unevaluated);
5501 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
5502 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
5503 InitializationSequence Init(Self, To, Kind, FromPtr);
5504 if (Init.Failed())
5505 return false;
5506
5507 ExprResult Result = Init.Perform(Self, To, Kind, FromPtr);
5508 return !Result.isInvalid() && !SFINAE.hasErrorOccurred();
5509 }
5510
5511 case BTT_IsAssignable:
5512 case BTT_IsNothrowAssignable:
5513 case BTT_IsTriviallyAssignable: {
5514 // C++11 [meta.unary.prop]p3:
5515 // is_trivially_assignable is defined as:
5516 // is_assignable<T, U>::value is true and the assignment, as defined by
5517 // is_assignable, is known to call no operation that is not trivial
5518 //
5519 // is_assignable is defined as:
5520 // The expression declval<T>() = declval<U>() is well-formed when
5521 // treated as an unevaluated operand (Clause 5).
5522 //
5523 // For both, T and U shall be complete types, (possibly cv-qualified)
5524 // void, or arrays of unknown bound.
5525 if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() &&
5526 Self.RequireCompleteType(KeyLoc, LhsT,
5527 diag::err_incomplete_type_used_in_type_trait_expr))
5528 return false;
5529 if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() &&
5530 Self.RequireCompleteType(KeyLoc, RhsT,
5531 diag::err_incomplete_type_used_in_type_trait_expr))
5532 return false;
5533
5534 // cv void is never assignable.
5535 if (LhsT->isVoidType() || RhsT->isVoidType())
5536 return false;
5537
5538 // Build expressions that emulate the effect of declval<T>() and
5539 // declval<U>().
5540 if (LhsT->isObjectType() || LhsT->isFunctionType())
5541 LhsT = Self.Context.getRValueReferenceType(LhsT);
5542 if (RhsT->isObjectType() || RhsT->isFunctionType())
5543 RhsT = Self.Context.getRValueReferenceType(RhsT);
5544 OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
5545 Expr::getValueKindForType(LhsT));
5546 OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context),
5547 Expr::getValueKindForType(RhsT));
5548
5549 // Attempt the assignment in an unevaluated context within a SFINAE
5550 // trap at translation unit scope.
5551 EnterExpressionEvaluationContext Unevaluated(
5552 Self, Sema::ExpressionEvaluationContext::Unevaluated);
5553 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
5554 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
5555 ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs,
5556 &Rhs);
5557 if (Result.isInvalid())
5558 return false;
5559
5560 // Treat the assignment as unused for the purpose of -Wdeprecated-volatile.
5561 Self.CheckUnusedVolatileAssignment(Result.get());
5562
5563 if (SFINAE.hasErrorOccurred())
5564 return false;
5565
5566 if (BTT == BTT_IsAssignable)
5567 return true;
5568
5569 if (BTT == BTT_IsNothrowAssignable)
5570 return Self.canThrow(Result.get()) == CT_Cannot;
5571
5572 if (BTT == BTT_IsTriviallyAssignable) {
5573 // Under Objective-C ARC and Weak, if the destination has non-trivial
5574 // Objective-C lifetime, this is a non-trivial assignment.
5575 if (LhsT.getNonReferenceType().hasNonTrivialObjCLifetime())
5576 return false;
5577
5578 return !Result.get()->hasNonTrivialCall(Self.Context);
5579 }
5580
5581 llvm_unreachable("unhandled type trait");
5582 return false;
5583 }
5584 default: llvm_unreachable("not a BTT");
5585 }
5586 llvm_unreachable("Unknown type trait or not implemented");
5587 }
5588
ActOnArrayTypeTrait(ArrayTypeTrait ATT,SourceLocation KWLoc,ParsedType Ty,Expr * DimExpr,SourceLocation RParen)5589 ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT,
5590 SourceLocation KWLoc,
5591 ParsedType Ty,
5592 Expr* DimExpr,
5593 SourceLocation RParen) {
5594 TypeSourceInfo *TSInfo;
5595 QualType T = GetTypeFromParser(Ty, &TSInfo);
5596 if (!TSInfo)
5597 TSInfo = Context.getTrivialTypeSourceInfo(T);
5598
5599 return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen);
5600 }
5601
EvaluateArrayTypeTrait(Sema & Self,ArrayTypeTrait ATT,QualType T,Expr * DimExpr,SourceLocation KeyLoc)5602 static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT,
5603 QualType T, Expr *DimExpr,
5604 SourceLocation KeyLoc) {
5605 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
5606
5607 switch(ATT) {
5608 case ATT_ArrayRank:
5609 if (T->isArrayType()) {
5610 unsigned Dim = 0;
5611 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
5612 ++Dim;
5613 T = AT->getElementType();
5614 }
5615 return Dim;
5616 }
5617 return 0;
5618
5619 case ATT_ArrayExtent: {
5620 llvm::APSInt Value;
5621 uint64_t Dim;
5622 if (Self.VerifyIntegerConstantExpression(
5623 DimExpr, &Value, diag::err_dimension_expr_not_constant_integer)
5624 .isInvalid())
5625 return 0;
5626 if (Value.isSigned() && Value.isNegative()) {
5627 Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer)
5628 << DimExpr->getSourceRange();
5629 return 0;
5630 }
5631 Dim = Value.getLimitedValue();
5632
5633 if (T->isArrayType()) {
5634 unsigned D = 0;
5635 bool Matched = false;
5636 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
5637 if (Dim == D) {
5638 Matched = true;
5639 break;
5640 }
5641 ++D;
5642 T = AT->getElementType();
5643 }
5644
5645 if (Matched && T->isArrayType()) {
5646 if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T))
5647 return CAT->getSize().getLimitedValue();
5648 }
5649 }
5650 return 0;
5651 }
5652 }
5653 llvm_unreachable("Unknown type trait or not implemented");
5654 }
5655
BuildArrayTypeTrait(ArrayTypeTrait ATT,SourceLocation KWLoc,TypeSourceInfo * TSInfo,Expr * DimExpr,SourceLocation RParen)5656 ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT,
5657 SourceLocation KWLoc,
5658 TypeSourceInfo *TSInfo,
5659 Expr* DimExpr,
5660 SourceLocation RParen) {
5661 QualType T = TSInfo->getType();
5662
5663 // FIXME: This should likely be tracked as an APInt to remove any host
5664 // assumptions about the width of size_t on the target.
5665 uint64_t Value = 0;
5666 if (!T->isDependentType())
5667 Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc);
5668
5669 // While the specification for these traits from the Embarcadero C++
5670 // compiler's documentation says the return type is 'unsigned int', Clang
5671 // returns 'size_t'. On Windows, the primary platform for the Embarcadero
5672 // compiler, there is no difference. On several other platforms this is an
5673 // important distinction.
5674 return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr,
5675 RParen, Context.getSizeType());
5676 }
5677
ActOnExpressionTrait(ExpressionTrait ET,SourceLocation KWLoc,Expr * Queried,SourceLocation RParen)5678 ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET,
5679 SourceLocation KWLoc,
5680 Expr *Queried,
5681 SourceLocation RParen) {
5682 // If error parsing the expression, ignore.
5683 if (!Queried)
5684 return ExprError();
5685
5686 ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen);
5687
5688 return Result;
5689 }
5690
EvaluateExpressionTrait(ExpressionTrait ET,Expr * E)5691 static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) {
5692 switch (ET) {
5693 case ET_IsLValueExpr: return E->isLValue();
5694 case ET_IsRValueExpr:
5695 return E->isPRValue();
5696 }
5697 llvm_unreachable("Expression trait not covered by switch");
5698 }
5699
BuildExpressionTrait(ExpressionTrait ET,SourceLocation KWLoc,Expr * Queried,SourceLocation RParen)5700 ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET,
5701 SourceLocation KWLoc,
5702 Expr *Queried,
5703 SourceLocation RParen) {
5704 if (Queried->isTypeDependent()) {
5705 // Delay type-checking for type-dependent expressions.
5706 } else if (Queried->getType()->isPlaceholderType()) {
5707 ExprResult PE = CheckPlaceholderExpr(Queried);
5708 if (PE.isInvalid()) return ExprError();
5709 return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen);
5710 }
5711
5712 bool Value = EvaluateExpressionTrait(ET, Queried);
5713
5714 return new (Context)
5715 ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy);
5716 }
5717
CheckPointerToMemberOperands(ExprResult & LHS,ExprResult & RHS,ExprValueKind & VK,SourceLocation Loc,bool isIndirect)5718 QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS,
5719 ExprValueKind &VK,
5720 SourceLocation Loc,
5721 bool isIndirect) {
5722 assert(!LHS.get()->getType()->isPlaceholderType() &&
5723 !RHS.get()->getType()->isPlaceholderType() &&
5724 "placeholders should have been weeded out by now");
5725
5726 // The LHS undergoes lvalue conversions if this is ->*, and undergoes the
5727 // temporary materialization conversion otherwise.
5728 if (isIndirect)
5729 LHS = DefaultLvalueConversion(LHS.get());
5730 else if (LHS.get()->isPRValue())
5731 LHS = TemporaryMaterializationConversion(LHS.get());
5732 if (LHS.isInvalid())
5733 return QualType();
5734
5735 // The RHS always undergoes lvalue conversions.
5736 RHS = DefaultLvalueConversion(RHS.get());
5737 if (RHS.isInvalid()) return QualType();
5738
5739 const char *OpSpelling = isIndirect ? "->*" : ".*";
5740 // C++ 5.5p2
5741 // The binary operator .* [p3: ->*] binds its second operand, which shall
5742 // be of type "pointer to member of T" (where T is a completely-defined
5743 // class type) [...]
5744 QualType RHSType = RHS.get()->getType();
5745 const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>();
5746 if (!MemPtr) {
5747 Diag(Loc, diag::err_bad_memptr_rhs)
5748 << OpSpelling << RHSType << RHS.get()->getSourceRange();
5749 return QualType();
5750 }
5751
5752 QualType Class(MemPtr->getClass(), 0);
5753
5754 // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the
5755 // member pointer points must be completely-defined. However, there is no
5756 // reason for this semantic distinction, and the rule is not enforced by
5757 // other compilers. Therefore, we do not check this property, as it is
5758 // likely to be considered a defect.
5759
5760 // C++ 5.5p2
5761 // [...] to its first operand, which shall be of class T or of a class of
5762 // which T is an unambiguous and accessible base class. [p3: a pointer to
5763 // such a class]
5764 QualType LHSType = LHS.get()->getType();
5765 if (isIndirect) {
5766 if (const PointerType *Ptr = LHSType->getAs<PointerType>())
5767 LHSType = Ptr->getPointeeType();
5768 else {
5769 Diag(Loc, diag::err_bad_memptr_lhs)
5770 << OpSpelling << 1 << LHSType
5771 << FixItHint::CreateReplacement(SourceRange(Loc), ".*");
5772 return QualType();
5773 }
5774 }
5775
5776 if (!Context.hasSameUnqualifiedType(Class, LHSType)) {
5777 // If we want to check the hierarchy, we need a complete type.
5778 if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs,
5779 OpSpelling, (int)isIndirect)) {
5780 return QualType();
5781 }
5782
5783 if (!IsDerivedFrom(Loc, LHSType, Class)) {
5784 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling
5785 << (int)isIndirect << LHS.get()->getType();
5786 return QualType();
5787 }
5788
5789 CXXCastPath BasePath;
5790 if (CheckDerivedToBaseConversion(
5791 LHSType, Class, Loc,
5792 SourceRange(LHS.get()->getBeginLoc(), RHS.get()->getEndLoc()),
5793 &BasePath))
5794 return QualType();
5795
5796 // Cast LHS to type of use.
5797 QualType UseType = Context.getQualifiedType(Class, LHSType.getQualifiers());
5798 if (isIndirect)
5799 UseType = Context.getPointerType(UseType);
5800 ExprValueKind VK = isIndirect ? VK_PRValue : LHS.get()->getValueKind();
5801 LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK,
5802 &BasePath);
5803 }
5804
5805 if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) {
5806 // Diagnose use of pointer-to-member type which when used as
5807 // the functional cast in a pointer-to-member expression.
5808 Diag(Loc, diag::err_pointer_to_member_type) << isIndirect;
5809 return QualType();
5810 }
5811
5812 // C++ 5.5p2
5813 // The result is an object or a function of the type specified by the
5814 // second operand.
5815 // The cv qualifiers are the union of those in the pointer and the left side,
5816 // in accordance with 5.5p5 and 5.2.5.
5817 QualType Result = MemPtr->getPointeeType();
5818 Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers());
5819
5820 // C++0x [expr.mptr.oper]p6:
5821 // In a .* expression whose object expression is an rvalue, the program is
5822 // ill-formed if the second operand is a pointer to member function with
5823 // ref-qualifier &. In a ->* expression or in a .* expression whose object
5824 // expression is an lvalue, the program is ill-formed if the second operand
5825 // is a pointer to member function with ref-qualifier &&.
5826 if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) {
5827 switch (Proto->getRefQualifier()) {
5828 case RQ_None:
5829 // Do nothing
5830 break;
5831
5832 case RQ_LValue:
5833 if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) {
5834 // C++2a allows functions with ref-qualifier & if their cv-qualifier-seq
5835 // is (exactly) 'const'.
5836 if (Proto->isConst() && !Proto->isVolatile())
5837 Diag(Loc, getLangOpts().CPlusPlus20
5838 ? diag::warn_cxx17_compat_pointer_to_const_ref_member_on_rvalue
5839 : diag::ext_pointer_to_const_ref_member_on_rvalue);
5840 else
5841 Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
5842 << RHSType << 1 << LHS.get()->getSourceRange();
5843 }
5844 break;
5845
5846 case RQ_RValue:
5847 if (isIndirect || !LHS.get()->Classify(Context).isRValue())
5848 Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
5849 << RHSType << 0 << LHS.get()->getSourceRange();
5850 break;
5851 }
5852 }
5853
5854 // C++ [expr.mptr.oper]p6:
5855 // The result of a .* expression whose second operand is a pointer
5856 // to a data member is of the same value category as its
5857 // first operand. The result of a .* expression whose second
5858 // operand is a pointer to a member function is a prvalue. The
5859 // result of an ->* expression is an lvalue if its second operand
5860 // is a pointer to data member and a prvalue otherwise.
5861 if (Result->isFunctionType()) {
5862 VK = VK_PRValue;
5863 return Context.BoundMemberTy;
5864 } else if (isIndirect) {
5865 VK = VK_LValue;
5866 } else {
5867 VK = LHS.get()->getValueKind();
5868 }
5869
5870 return Result;
5871 }
5872
5873 /// Try to convert a type to another according to C++11 5.16p3.
5874 ///
5875 /// This is part of the parameter validation for the ? operator. If either
5876 /// value operand is a class type, the two operands are attempted to be
5877 /// converted to each other. This function does the conversion in one direction.
5878 /// It returns true if the program is ill-formed and has already been diagnosed
5879 /// as such.
TryClassUnification(Sema & Self,Expr * From,Expr * To,SourceLocation QuestionLoc,bool & HaveConversion,QualType & ToType)5880 static bool TryClassUnification(Sema &Self, Expr *From, Expr *To,
5881 SourceLocation QuestionLoc,
5882 bool &HaveConversion,
5883 QualType &ToType) {
5884 HaveConversion = false;
5885 ToType = To->getType();
5886
5887 InitializationKind Kind =
5888 InitializationKind::CreateCopy(To->getBeginLoc(), SourceLocation());
5889 // C++11 5.16p3
5890 // The process for determining whether an operand expression E1 of type T1
5891 // can be converted to match an operand expression E2 of type T2 is defined
5892 // as follows:
5893 // -- If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
5894 // implicitly converted to type "lvalue reference to T2", subject to the
5895 // constraint that in the conversion the reference must bind directly to
5896 // an lvalue.
5897 // -- If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
5898 // implicitly converted to the type "rvalue reference to R2", subject to
5899 // the constraint that the reference must bind directly.
5900 if (To->isGLValue()) {
5901 QualType T = Self.Context.getReferenceQualifiedType(To);
5902 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);
5903
5904 InitializationSequence InitSeq(Self, Entity, Kind, From);
5905 if (InitSeq.isDirectReferenceBinding()) {
5906 ToType = T;
5907 HaveConversion = true;
5908 return false;
5909 }
5910
5911 if (InitSeq.isAmbiguous())
5912 return InitSeq.Diagnose(Self, Entity, Kind, From);
5913 }
5914
5915 // -- If E2 is an rvalue, or if the conversion above cannot be done:
5916 // -- if E1 and E2 have class type, and the underlying class types are
5917 // the same or one is a base class of the other:
5918 QualType FTy = From->getType();
5919 QualType TTy = To->getType();
5920 const RecordType *FRec = FTy->getAs<RecordType>();
5921 const RecordType *TRec = TTy->getAs<RecordType>();
5922 bool FDerivedFromT = FRec && TRec && FRec != TRec &&
5923 Self.IsDerivedFrom(QuestionLoc, FTy, TTy);
5924 if (FRec && TRec && (FRec == TRec || FDerivedFromT ||
5925 Self.IsDerivedFrom(QuestionLoc, TTy, FTy))) {
5926 // E1 can be converted to match E2 if the class of T2 is the
5927 // same type as, or a base class of, the class of T1, and
5928 // [cv2 > cv1].
5929 if (FRec == TRec || FDerivedFromT) {
5930 if (TTy.isAtLeastAsQualifiedAs(FTy)) {
5931 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
5932 InitializationSequence InitSeq(Self, Entity, Kind, From);
5933 if (InitSeq) {
5934 HaveConversion = true;
5935 return false;
5936 }
5937
5938 if (InitSeq.isAmbiguous())
5939 return InitSeq.Diagnose(Self, Entity, Kind, From);
5940 }
5941 }
5942
5943 return false;
5944 }
5945
5946 // -- Otherwise: E1 can be converted to match E2 if E1 can be
5947 // implicitly converted to the type that expression E2 would have
5948 // if E2 were converted to an rvalue (or the type it has, if E2 is
5949 // an rvalue).
5950 //
5951 // This actually refers very narrowly to the lvalue-to-rvalue conversion, not
5952 // to the array-to-pointer or function-to-pointer conversions.
5953 TTy = TTy.getNonLValueExprType(Self.Context);
5954
5955 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
5956 InitializationSequence InitSeq(Self, Entity, Kind, From);
5957 HaveConversion = !InitSeq.Failed();
5958 ToType = TTy;
5959 if (InitSeq.isAmbiguous())
5960 return InitSeq.Diagnose(Self, Entity, Kind, From);
5961
5962 return false;
5963 }
5964
5965 /// Try to find a common type for two according to C++0x 5.16p5.
5966 ///
5967 /// This is part of the parameter validation for the ? operator. If either
5968 /// value operand is a class type, overload resolution is used to find a
5969 /// conversion to a common type.
FindConditionalOverload(Sema & Self,ExprResult & LHS,ExprResult & RHS,SourceLocation QuestionLoc)5970 static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS,
5971 SourceLocation QuestionLoc) {
5972 Expr *Args[2] = { LHS.get(), RHS.get() };
5973 OverloadCandidateSet CandidateSet(QuestionLoc,
5974 OverloadCandidateSet::CSK_Operator);
5975 Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args,
5976 CandidateSet);
5977
5978 OverloadCandidateSet::iterator Best;
5979 switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) {
5980 case OR_Success: {
5981 // We found a match. Perform the conversions on the arguments and move on.
5982 ExprResult LHSRes = Self.PerformImplicitConversion(
5983 LHS.get(), Best->BuiltinParamTypes[0], Best->Conversions[0],
5984 Sema::AA_Converting);
5985 if (LHSRes.isInvalid())
5986 break;
5987 LHS = LHSRes;
5988
5989 ExprResult RHSRes = Self.PerformImplicitConversion(
5990 RHS.get(), Best->BuiltinParamTypes[1], Best->Conversions[1],
5991 Sema::AA_Converting);
5992 if (RHSRes.isInvalid())
5993 break;
5994 RHS = RHSRes;
5995 if (Best->Function)
5996 Self.MarkFunctionReferenced(QuestionLoc, Best->Function);
5997 return false;
5998 }
5999
6000 case OR_No_Viable_Function:
6001
6002 // Emit a better diagnostic if one of the expressions is a null pointer
6003 // constant and the other is a pointer type. In this case, the user most
6004 // likely forgot to take the address of the other expression.
6005 if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
6006 return true;
6007
6008 Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
6009 << LHS.get()->getType() << RHS.get()->getType()
6010 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
6011 return true;
6012
6013 case OR_Ambiguous:
6014 Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl)
6015 << LHS.get()->getType() << RHS.get()->getType()
6016 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
6017 // FIXME: Print the possible common types by printing the return types of
6018 // the viable candidates.
6019 break;
6020
6021 case OR_Deleted:
6022 llvm_unreachable("Conditional operator has only built-in overloads");
6023 }
6024 return true;
6025 }
6026
6027 /// Perform an "extended" implicit conversion as returned by
6028 /// TryClassUnification.
ConvertForConditional(Sema & Self,ExprResult & E,QualType T)6029 static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) {
6030 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);
6031 InitializationKind Kind =
6032 InitializationKind::CreateCopy(E.get()->getBeginLoc(), SourceLocation());
6033 Expr *Arg = E.get();
6034 InitializationSequence InitSeq(Self, Entity, Kind, Arg);
6035 ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg);
6036 if (Result.isInvalid())
6037 return true;
6038
6039 E = Result;
6040 return false;
6041 }
6042
6043 // Check the condition operand of ?: to see if it is valid for the GCC
6044 // extension.
isValidVectorForConditionalCondition(ASTContext & Ctx,QualType CondTy)6045 static bool isValidVectorForConditionalCondition(ASTContext &Ctx,
6046 QualType CondTy) {
6047 if (!CondTy->isVectorType() && !CondTy->isExtVectorType())
6048 return false;
6049 const QualType EltTy =
6050 cast<VectorType>(CondTy.getCanonicalType())->getElementType();
6051 assert(!EltTy->isBooleanType() && !EltTy->isEnumeralType() &&
6052 "Vectors cant be boolean or enum types");
6053 return EltTy->isIntegralType(Ctx);
6054 }
6055
CheckVectorConditionalTypes(ExprResult & Cond,ExprResult & LHS,ExprResult & RHS,SourceLocation QuestionLoc)6056 QualType Sema::CheckVectorConditionalTypes(ExprResult &Cond, ExprResult &LHS,
6057 ExprResult &RHS,
6058 SourceLocation QuestionLoc) {
6059 LHS = DefaultFunctionArrayLvalueConversion(LHS.get());
6060 RHS = DefaultFunctionArrayLvalueConversion(RHS.get());
6061
6062 QualType CondType = Cond.get()->getType();
6063 const auto *CondVT = CondType->castAs<VectorType>();
6064 QualType CondElementTy = CondVT->getElementType();
6065 unsigned CondElementCount = CondVT->getNumElements();
6066 QualType LHSType = LHS.get()->getType();
6067 const auto *LHSVT = LHSType->getAs<VectorType>();
6068 QualType RHSType = RHS.get()->getType();
6069 const auto *RHSVT = RHSType->getAs<VectorType>();
6070
6071 QualType ResultType;
6072
6073
6074 if (LHSVT && RHSVT) {
6075 if (isa<ExtVectorType>(CondVT) != isa<ExtVectorType>(LHSVT)) {
6076 Diag(QuestionLoc, diag::err_conditional_vector_cond_result_mismatch)
6077 << /*isExtVector*/ isa<ExtVectorType>(CondVT);
6078 return {};
6079 }
6080
6081 // If both are vector types, they must be the same type.
6082 if (!Context.hasSameType(LHSType, RHSType)) {
6083 Diag(QuestionLoc, diag::err_conditional_vector_mismatched)
6084 << LHSType << RHSType;
6085 return {};
6086 }
6087 ResultType = LHSType;
6088 } else if (LHSVT || RHSVT) {
6089 ResultType = CheckVectorOperands(
6090 LHS, RHS, QuestionLoc, /*isCompAssign*/ false, /*AllowBothBool*/ true,
6091 /*AllowBoolConversions*/ false);
6092 if (ResultType.isNull())
6093 return {};
6094 } else {
6095 // Both are scalar.
6096 QualType ResultElementTy;
6097 LHSType = LHSType.getCanonicalType().getUnqualifiedType();
6098 RHSType = RHSType.getCanonicalType().getUnqualifiedType();
6099
6100 if (Context.hasSameType(LHSType, RHSType))
6101 ResultElementTy = LHSType;
6102 else
6103 ResultElementTy =
6104 UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional);
6105
6106 if (ResultElementTy->isEnumeralType()) {
6107 Diag(QuestionLoc, diag::err_conditional_vector_operand_type)
6108 << ResultElementTy;
6109 return {};
6110 }
6111 if (CondType->isExtVectorType())
6112 ResultType =
6113 Context.getExtVectorType(ResultElementTy, CondVT->getNumElements());
6114 else
6115 ResultType = Context.getVectorType(
6116 ResultElementTy, CondVT->getNumElements(), VectorType::GenericVector);
6117
6118 LHS = ImpCastExprToType(LHS.get(), ResultType, CK_VectorSplat);
6119 RHS = ImpCastExprToType(RHS.get(), ResultType, CK_VectorSplat);
6120 }
6121
6122 assert(!ResultType.isNull() && ResultType->isVectorType() &&
6123 (!CondType->isExtVectorType() || ResultType->isExtVectorType()) &&
6124 "Result should have been a vector type");
6125 auto *ResultVectorTy = ResultType->castAs<VectorType>();
6126 QualType ResultElementTy = ResultVectorTy->getElementType();
6127 unsigned ResultElementCount = ResultVectorTy->getNumElements();
6128
6129 if (ResultElementCount != CondElementCount) {
6130 Diag(QuestionLoc, diag::err_conditional_vector_size) << CondType
6131 << ResultType;
6132 return {};
6133 }
6134
6135 if (Context.getTypeSize(ResultElementTy) !=
6136 Context.getTypeSize(CondElementTy)) {
6137 Diag(QuestionLoc, diag::err_conditional_vector_element_size) << CondType
6138 << ResultType;
6139 return {};
6140 }
6141
6142 return ResultType;
6143 }
6144
6145 /// Check the operands of ?: under C++ semantics.
6146 ///
6147 /// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y
6148 /// extension. In this case, LHS == Cond. (But they're not aliases.)
6149 ///
6150 /// This function also implements GCC's vector extension and the
6151 /// OpenCL/ext_vector_type extension for conditionals. The vector extensions
6152 /// permit the use of a?b:c where the type of a is that of a integer vector with
6153 /// the same number of elements and size as the vectors of b and c. If one of
6154 /// either b or c is a scalar it is implicitly converted to match the type of
6155 /// the vector. Otherwise the expression is ill-formed. If both b and c are
6156 /// scalars, then b and c are checked and converted to the type of a if
6157 /// possible.
6158 ///
6159 /// The expressions are evaluated differently for GCC's and OpenCL's extensions.
6160 /// For the GCC extension, the ?: operator is evaluated as
6161 /// (a[0] != 0 ? b[0] : c[0], .. , a[n] != 0 ? b[n] : c[n]).
6162 /// For the OpenCL extensions, the ?: operator is evaluated as
6163 /// (most-significant-bit-set(a[0]) ? b[0] : c[0], .. ,
6164 /// most-significant-bit-set(a[n]) ? b[n] : c[n]).
CXXCheckConditionalOperands(ExprResult & Cond,ExprResult & LHS,ExprResult & RHS,ExprValueKind & VK,ExprObjectKind & OK,SourceLocation QuestionLoc)6165 QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS,
6166 ExprResult &RHS, ExprValueKind &VK,
6167 ExprObjectKind &OK,
6168 SourceLocation QuestionLoc) {
6169 // FIXME: Handle C99's complex types, block pointers and Obj-C++ interface
6170 // pointers.
6171
6172 // Assume r-value.
6173 VK = VK_PRValue;
6174 OK = OK_Ordinary;
6175 bool IsVectorConditional =
6176 isValidVectorForConditionalCondition(Context, Cond.get()->getType());
6177
6178 // C++11 [expr.cond]p1
6179 // The first expression is contextually converted to bool.
6180 if (!Cond.get()->isTypeDependent()) {
6181 ExprResult CondRes = IsVectorConditional
6182 ? DefaultFunctionArrayLvalueConversion(Cond.get())
6183 : CheckCXXBooleanCondition(Cond.get());
6184 if (CondRes.isInvalid())
6185 return QualType();
6186 Cond = CondRes;
6187 } else {
6188 // To implement C++, the first expression typically doesn't alter the result
6189 // type of the conditional, however the GCC compatible vector extension
6190 // changes the result type to be that of the conditional. Since we cannot
6191 // know if this is a vector extension here, delay the conversion of the
6192 // LHS/RHS below until later.
6193 return Context.DependentTy;
6194 }
6195
6196
6197 // Either of the arguments dependent?
6198 if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent())
6199 return Context.DependentTy;
6200
6201 // C++11 [expr.cond]p2
6202 // If either the second or the third operand has type (cv) void, ...
6203 QualType LTy = LHS.get()->getType();
6204 QualType RTy = RHS.get()->getType();
6205 bool LVoid = LTy->isVoidType();
6206 bool RVoid = RTy->isVoidType();
6207 if (LVoid || RVoid) {
6208 // ... one of the following shall hold:
6209 // -- The second or the third operand (but not both) is a (possibly
6210 // parenthesized) throw-expression; the result is of the type
6211 // and value category of the other.
6212 bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts());
6213 bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts());
6214
6215 // Void expressions aren't legal in the vector-conditional expressions.
6216 if (IsVectorConditional) {
6217 SourceRange DiagLoc =
6218 LVoid ? LHS.get()->getSourceRange() : RHS.get()->getSourceRange();
6219 bool IsThrow = LVoid ? LThrow : RThrow;
6220 Diag(DiagLoc.getBegin(), diag::err_conditional_vector_has_void)
6221 << DiagLoc << IsThrow;
6222 return QualType();
6223 }
6224
6225 if (LThrow != RThrow) {
6226 Expr *NonThrow = LThrow ? RHS.get() : LHS.get();
6227 VK = NonThrow->getValueKind();
6228 // DR (no number yet): the result is a bit-field if the
6229 // non-throw-expression operand is a bit-field.
6230 OK = NonThrow->getObjectKind();
6231 return NonThrow->getType();
6232 }
6233
6234 // -- Both the second and third operands have type void; the result is of
6235 // type void and is a prvalue.
6236 if (LVoid && RVoid)
6237 return Context.VoidTy;
6238
6239 // Neither holds, error.
6240 Diag(QuestionLoc, diag::err_conditional_void_nonvoid)
6241 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1)
6242 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
6243 return QualType();
6244 }
6245
6246 // Neither is void.
6247 if (IsVectorConditional)
6248 return CheckVectorConditionalTypes(Cond, LHS, RHS, QuestionLoc);
6249
6250 // C++11 [expr.cond]p3
6251 // Otherwise, if the second and third operand have different types, and
6252 // either has (cv) class type [...] an attempt is made to convert each of
6253 // those operands to the type of the other.
6254 if (!Context.hasSameType(LTy, RTy) &&
6255 (LTy->isRecordType() || RTy->isRecordType())) {
6256 // These return true if a single direction is already ambiguous.
6257 QualType L2RType, R2LType;
6258 bool HaveL2R, HaveR2L;
6259 if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType))
6260 return QualType();
6261 if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType))
6262 return QualType();
6263
6264 // If both can be converted, [...] the program is ill-formed.
6265 if (HaveL2R && HaveR2L) {
6266 Diag(QuestionLoc, diag::err_conditional_ambiguous)
6267 << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
6268 return QualType();
6269 }
6270
6271 // If exactly one conversion is possible, that conversion is applied to
6272 // the chosen operand and the converted operands are used in place of the
6273 // original operands for the remainder of this section.
6274 if (HaveL2R) {
6275 if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid())
6276 return QualType();
6277 LTy = LHS.get()->getType();
6278 } else if (HaveR2L) {
6279 if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid())
6280 return QualType();
6281 RTy = RHS.get()->getType();
6282 }
6283 }
6284
6285 // C++11 [expr.cond]p3
6286 // if both are glvalues of the same value category and the same type except
6287 // for cv-qualification, an attempt is made to convert each of those
6288 // operands to the type of the other.
6289 // FIXME:
6290 // Resolving a defect in P0012R1: we extend this to cover all cases where
6291 // one of the operands is reference-compatible with the other, in order
6292 // to support conditionals between functions differing in noexcept. This
6293 // will similarly cover difference in array bounds after P0388R4.
6294 // FIXME: If LTy and RTy have a composite pointer type, should we convert to
6295 // that instead?
6296 ExprValueKind LVK = LHS.get()->getValueKind();
6297 ExprValueKind RVK = RHS.get()->getValueKind();
6298 if (!Context.hasSameType(LTy, RTy) && LVK == RVK && LVK != VK_PRValue) {
6299 // DerivedToBase was already handled by the class-specific case above.
6300 // FIXME: Should we allow ObjC conversions here?
6301 const ReferenceConversions AllowedConversions =
6302 ReferenceConversions::Qualification |
6303 ReferenceConversions::NestedQualification |
6304 ReferenceConversions::Function;
6305
6306 ReferenceConversions RefConv;
6307 if (CompareReferenceRelationship(QuestionLoc, LTy, RTy, &RefConv) ==
6308 Ref_Compatible &&
6309 !(RefConv & ~AllowedConversions) &&
6310 // [...] subject to the constraint that the reference must bind
6311 // directly [...]
6312 !RHS.get()->refersToBitField() && !RHS.get()->refersToVectorElement()) {
6313 RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK);
6314 RTy = RHS.get()->getType();
6315 } else if (CompareReferenceRelationship(QuestionLoc, RTy, LTy, &RefConv) ==
6316 Ref_Compatible &&
6317 !(RefConv & ~AllowedConversions) &&
6318 !LHS.get()->refersToBitField() &&
6319 !LHS.get()->refersToVectorElement()) {
6320 LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK);
6321 LTy = LHS.get()->getType();
6322 }
6323 }
6324
6325 // C++11 [expr.cond]p4
6326 // If the second and third operands are glvalues of the same value
6327 // category and have the same type, the result is of that type and
6328 // value category and it is a bit-field if the second or the third
6329 // operand is a bit-field, or if both are bit-fields.
6330 // We only extend this to bitfields, not to the crazy other kinds of
6331 // l-values.
6332 bool Same = Context.hasSameType(LTy, RTy);
6333 if (Same && LVK == RVK && LVK != VK_PRValue &&
6334 LHS.get()->isOrdinaryOrBitFieldObject() &&
6335 RHS.get()->isOrdinaryOrBitFieldObject()) {
6336 VK = LHS.get()->getValueKind();
6337 if (LHS.get()->getObjectKind() == OK_BitField ||
6338 RHS.get()->getObjectKind() == OK_BitField)
6339 OK = OK_BitField;
6340
6341 // If we have function pointer types, unify them anyway to unify their
6342 // exception specifications, if any.
6343 if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) {
6344 Qualifiers Qs = LTy.getQualifiers();
6345 LTy = FindCompositePointerType(QuestionLoc, LHS, RHS,
6346 /*ConvertArgs*/false);
6347 LTy = Context.getQualifiedType(LTy, Qs);
6348
6349 assert(!LTy.isNull() && "failed to find composite pointer type for "
6350 "canonically equivalent function ptr types");
6351 assert(Context.hasSameType(LTy, RTy) && "bad composite pointer type");
6352 }
6353
6354 return LTy;
6355 }
6356
6357 // C++11 [expr.cond]p5
6358 // Otherwise, the result is a prvalue. If the second and third operands
6359 // do not have the same type, and either has (cv) class type, ...
6360 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) {
6361 // ... overload resolution is used to determine the conversions (if any)
6362 // to be applied to the operands. If the overload resolution fails, the
6363 // program is ill-formed.
6364 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc))
6365 return QualType();
6366 }
6367
6368 // C++11 [expr.cond]p6
6369 // Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
6370 // conversions are performed on the second and third operands.
6371 LHS = DefaultFunctionArrayLvalueConversion(LHS.get());
6372 RHS = DefaultFunctionArrayLvalueConversion(RHS.get());
6373 if (LHS.isInvalid() || RHS.isInvalid())
6374 return QualType();
6375 LTy = LHS.get()->getType();
6376 RTy = RHS.get()->getType();
6377
6378 // After those conversions, one of the following shall hold:
6379 // -- The second and third operands have the same type; the result
6380 // is of that type. If the operands have class type, the result
6381 // is a prvalue temporary of the result type, which is
6382 // copy-initialized from either the second operand or the third
6383 // operand depending on the value of the first operand.
6384 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) {
6385 if (LTy->isRecordType()) {
6386 // The operands have class type. Make a temporary copy.
6387 InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy);
6388
6389 ExprResult LHSCopy = PerformCopyInitialization(Entity,
6390 SourceLocation(),
6391 LHS);
6392 if (LHSCopy.isInvalid())
6393 return QualType();
6394
6395 ExprResult RHSCopy = PerformCopyInitialization(Entity,
6396 SourceLocation(),
6397 RHS);
6398 if (RHSCopy.isInvalid())
6399 return QualType();
6400
6401 LHS = LHSCopy;
6402 RHS = RHSCopy;
6403 }
6404
6405 // If we have function pointer types, unify them anyway to unify their
6406 // exception specifications, if any.
6407 if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) {
6408 LTy = FindCompositePointerType(QuestionLoc, LHS, RHS);
6409 assert(!LTy.isNull() && "failed to find composite pointer type for "
6410 "canonically equivalent function ptr types");
6411 }
6412
6413 return LTy;
6414 }
6415
6416 // Extension: conditional operator involving vector types.
6417 if (LTy->isVectorType() || RTy->isVectorType())
6418 return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false,
6419 /*AllowBothBool*/true,
6420 /*AllowBoolConversions*/false);
6421
6422 // -- The second and third operands have arithmetic or enumeration type;
6423 // the usual arithmetic conversions are performed to bring them to a
6424 // common type, and the result is of that type.
6425 if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
6426 QualType ResTy =
6427 UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional);
6428 if (LHS.isInvalid() || RHS.isInvalid())
6429 return QualType();
6430 if (ResTy.isNull()) {
6431 Diag(QuestionLoc,
6432 diag::err_typecheck_cond_incompatible_operands) << LTy << RTy
6433 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
6434 return QualType();
6435 }
6436
6437 LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy));
6438 RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy));
6439
6440 return ResTy;
6441 }
6442
6443 // -- The second and third operands have pointer type, or one has pointer
6444 // type and the other is a null pointer constant, or both are null
6445 // pointer constants, at least one of which is non-integral; pointer
6446 // conversions and qualification conversions are performed to bring them
6447 // to their composite pointer type. The result is of the composite
6448 // pointer type.
6449 // -- The second and third operands have pointer to member type, or one has
6450 // pointer to member type and the other is a null pointer constant;
6451 // pointer to member conversions and qualification conversions are
6452 // performed to bring them to a common type, whose cv-qualification
6453 // shall match the cv-qualification of either the second or the third
6454 // operand. The result is of the common type.
6455 QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS);
6456 if (!Composite.isNull())
6457 return Composite;
6458
6459 // Similarly, attempt to find composite type of two objective-c pointers.
6460 Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc);
6461 if (LHS.isInvalid() || RHS.isInvalid())
6462 return QualType();
6463 if (!Composite.isNull())
6464 return Composite;
6465
6466 // Check if we are using a null with a non-pointer type.
6467 if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
6468 return QualType();
6469
6470 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
6471 << LHS.get()->getType() << RHS.get()->getType()
6472 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
6473 return QualType();
6474 }
6475
6476 static FunctionProtoType::ExceptionSpecInfo
mergeExceptionSpecs(Sema & S,FunctionProtoType::ExceptionSpecInfo ESI1,FunctionProtoType::ExceptionSpecInfo ESI2,SmallVectorImpl<QualType> & ExceptionTypeStorage)6477 mergeExceptionSpecs(Sema &S, FunctionProtoType::ExceptionSpecInfo ESI1,
6478 FunctionProtoType::ExceptionSpecInfo ESI2,
6479 SmallVectorImpl<QualType> &ExceptionTypeStorage) {
6480 ExceptionSpecificationType EST1 = ESI1.Type;
6481 ExceptionSpecificationType EST2 = ESI2.Type;
6482
6483 // If either of them can throw anything, that is the result.
6484 if (EST1 == EST_None) return ESI1;
6485 if (EST2 == EST_None) return ESI2;
6486 if (EST1 == EST_MSAny) return ESI1;
6487 if (EST2 == EST_MSAny) return ESI2;
6488 if (EST1 == EST_NoexceptFalse) return ESI1;
6489 if (EST2 == EST_NoexceptFalse) return ESI2;
6490
6491 // If either of them is non-throwing, the result is the other.
6492 if (EST1 == EST_NoThrow) return ESI2;
6493 if (EST2 == EST_NoThrow) return ESI1;
6494 if (EST1 == EST_DynamicNone) return ESI2;
6495 if (EST2 == EST_DynamicNone) return ESI1;
6496 if (EST1 == EST_BasicNoexcept) return ESI2;
6497 if (EST2 == EST_BasicNoexcept) return ESI1;
6498 if (EST1 == EST_NoexceptTrue) return ESI2;
6499 if (EST2 == EST_NoexceptTrue) return ESI1;
6500
6501 // If we're left with value-dependent computed noexcept expressions, we're
6502 // stuck. Before C++17, we can just drop the exception specification entirely,
6503 // since it's not actually part of the canonical type. And this should never
6504 // happen in C++17, because it would mean we were computing the composite
6505 // pointer type of dependent types, which should never happen.
6506 if (EST1 == EST_DependentNoexcept || EST2 == EST_DependentNoexcept) {
6507 assert(!S.getLangOpts().CPlusPlus17 &&
6508 "computing composite pointer type of dependent types");
6509 return FunctionProtoType::ExceptionSpecInfo();
6510 }
6511
6512 // Switch over the possibilities so that people adding new values know to
6513 // update this function.
6514 switch (EST1) {
6515 case EST_None:
6516 case EST_DynamicNone:
6517 case EST_MSAny:
6518 case EST_BasicNoexcept:
6519 case EST_DependentNoexcept:
6520 case EST_NoexceptFalse:
6521 case EST_NoexceptTrue:
6522 case EST_NoThrow:
6523 llvm_unreachable("handled above");
6524
6525 case EST_Dynamic: {
6526 // This is the fun case: both exception specifications are dynamic. Form
6527 // the union of the two lists.
6528 assert(EST2 == EST_Dynamic && "other cases should already be handled");
6529 llvm::SmallPtrSet<QualType, 8> Found;
6530 for (auto &Exceptions : {ESI1.Exceptions, ESI2.Exceptions})
6531 for (QualType E : Exceptions)
6532 if (Found.insert(S.Context.getCanonicalType(E)).second)
6533 ExceptionTypeStorage.push_back(E);
6534
6535 FunctionProtoType::ExceptionSpecInfo Result(EST_Dynamic);
6536 Result.Exceptions = ExceptionTypeStorage;
6537 return Result;
6538 }
6539
6540 case EST_Unevaluated:
6541 case EST_Uninstantiated:
6542 case EST_Unparsed:
6543 llvm_unreachable("shouldn't see unresolved exception specifications here");
6544 }
6545
6546 llvm_unreachable("invalid ExceptionSpecificationType");
6547 }
6548
6549 /// Find a merged pointer type and convert the two expressions to it.
6550 ///
6551 /// This finds the composite pointer type for \p E1 and \p E2 according to
6552 /// C++2a [expr.type]p3. It converts both expressions to this type and returns
6553 /// it. It does not emit diagnostics (FIXME: that's not true if \p ConvertArgs
6554 /// is \c true).
6555 ///
6556 /// \param Loc The location of the operator requiring these two expressions to
6557 /// be converted to the composite pointer type.
6558 ///
6559 /// \param ConvertArgs If \c false, do not convert E1 and E2 to the target type.
FindCompositePointerType(SourceLocation Loc,Expr * & E1,Expr * & E2,bool ConvertArgs)6560 QualType Sema::FindCompositePointerType(SourceLocation Loc,
6561 Expr *&E1, Expr *&E2,
6562 bool ConvertArgs) {
6563 assert(getLangOpts().CPlusPlus && "This function assumes C++");
6564
6565 // C++1z [expr]p14:
6566 // The composite pointer type of two operands p1 and p2 having types T1
6567 // and T2
6568 QualType T1 = E1->getType(), T2 = E2->getType();
6569
6570 // where at least one is a pointer or pointer to member type or
6571 // std::nullptr_t is:
6572 bool T1IsPointerLike = T1->isAnyPointerType() || T1->isMemberPointerType() ||
6573 T1->isNullPtrType();
6574 bool T2IsPointerLike = T2->isAnyPointerType() || T2->isMemberPointerType() ||
6575 T2->isNullPtrType();
6576 if (!T1IsPointerLike && !T2IsPointerLike)
6577 return QualType();
6578
6579 // - if both p1 and p2 are null pointer constants, std::nullptr_t;
6580 // This can't actually happen, following the standard, but we also use this
6581 // to implement the end of [expr.conv], which hits this case.
6582 //
6583 // - if either p1 or p2 is a null pointer constant, T2 or T1, respectively;
6584 if (T1IsPointerLike &&
6585 E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
6586 if (ConvertArgs)
6587 E2 = ImpCastExprToType(E2, T1, T1->isMemberPointerType()
6588 ? CK_NullToMemberPointer
6589 : CK_NullToPointer).get();
6590 return T1;
6591 }
6592 if (T2IsPointerLike &&
6593 E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
6594 if (ConvertArgs)
6595 E1 = ImpCastExprToType(E1, T2, T2->isMemberPointerType()
6596 ? CK_NullToMemberPointer
6597 : CK_NullToPointer).get();
6598 return T2;
6599 }
6600
6601 // Now both have to be pointers or member pointers.
6602 if (!T1IsPointerLike || !T2IsPointerLike)
6603 return QualType();
6604 assert(!T1->isNullPtrType() && !T2->isNullPtrType() &&
6605 "nullptr_t should be a null pointer constant");
6606
6607 struct Step {
6608 enum Kind { Pointer, ObjCPointer, MemberPointer, Array } K;
6609 // Qualifiers to apply under the step kind.
6610 Qualifiers Quals;
6611 /// The class for a pointer-to-member; a constant array type with a bound
6612 /// (if any) for an array.
6613 const Type *ClassOrBound;
6614
6615 Step(Kind K, const Type *ClassOrBound = nullptr)
6616 : K(K), Quals(), ClassOrBound(ClassOrBound) {}
6617 QualType rebuild(ASTContext &Ctx, QualType T) const {
6618 T = Ctx.getQualifiedType(T, Quals);
6619 switch (K) {
6620 case Pointer:
6621 return Ctx.getPointerType(T);
6622 case MemberPointer:
6623 return Ctx.getMemberPointerType(T, ClassOrBound);
6624 case ObjCPointer:
6625 return Ctx.getObjCObjectPointerType(T);
6626 case Array:
6627 if (auto *CAT = cast_or_null<ConstantArrayType>(ClassOrBound))
6628 return Ctx.getConstantArrayType(T, CAT->getSize(), nullptr,
6629 ArrayType::Normal, 0);
6630 else
6631 return Ctx.getIncompleteArrayType(T, ArrayType::Normal, 0);
6632 }
6633 llvm_unreachable("unknown step kind");
6634 }
6635 };
6636
6637 SmallVector<Step, 8> Steps;
6638
6639 // - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1
6640 // is reference-related to C2 or C2 is reference-related to C1 (8.6.3),
6641 // the cv-combined type of T1 and T2 or the cv-combined type of T2 and T1,
6642 // respectively;
6643 // - if T1 is "pointer to member of C1 of type cv1 U1" and T2 is "pointer
6644 // to member of C2 of type cv2 U2" for some non-function type U, where
6645 // C1 is reference-related to C2 or C2 is reference-related to C1, the
6646 // cv-combined type of T2 and T1 or the cv-combined type of T1 and T2,
6647 // respectively;
6648 // - if T1 and T2 are similar types (4.5), the cv-combined type of T1 and
6649 // T2;
6650 //
6651 // Dismantle T1 and T2 to simultaneously determine whether they are similar
6652 // and to prepare to form the cv-combined type if so.
6653 QualType Composite1 = T1;
6654 QualType Composite2 = T2;
6655 unsigned NeedConstBefore = 0;
6656 while (true) {
6657 assert(!Composite1.isNull() && !Composite2.isNull());
6658
6659 Qualifiers Q1, Q2;
6660 Composite1 = Context.getUnqualifiedArrayType(Composite1, Q1);
6661 Composite2 = Context.getUnqualifiedArrayType(Composite2, Q2);
6662
6663 // Top-level qualifiers are ignored. Merge at all lower levels.
6664 if (!Steps.empty()) {
6665 // Find the qualifier union: (approximately) the unique minimal set of
6666 // qualifiers that is compatible with both types.
6667 Qualifiers Quals = Qualifiers::fromCVRUMask(Q1.getCVRUQualifiers() |
6668 Q2.getCVRUQualifiers());
6669
6670 // Under one level of pointer or pointer-to-member, we can change to an
6671 // unambiguous compatible address space.
6672 if (Q1.getAddressSpace() == Q2.getAddressSpace()) {
6673 Quals.setAddressSpace(Q1.getAddressSpace());
6674 } else if (Steps.size() == 1) {
6675 bool MaybeQ1 = Q1.isAddressSpaceSupersetOf(Q2);
6676 bool MaybeQ2 = Q2.isAddressSpaceSupersetOf(Q1);
6677 if (MaybeQ1 == MaybeQ2) {
6678 // Exception for ptr size address spaces. Should be able to choose
6679 // either address space during comparison.
6680 if (isPtrSizeAddressSpace(Q1.getAddressSpace()) ||
6681 isPtrSizeAddressSpace(Q2.getAddressSpace()))
6682 MaybeQ1 = true;
6683 else
6684 return QualType(); // No unique best address space.
6685 }
6686 Quals.setAddressSpace(MaybeQ1 ? Q1.getAddressSpace()
6687 : Q2.getAddressSpace());
6688 } else {
6689 return QualType();
6690 }
6691
6692 // FIXME: In C, we merge __strong and none to __strong at the top level.
6693 if (Q1.getObjCGCAttr() == Q2.getObjCGCAttr())
6694 Quals.setObjCGCAttr(Q1.getObjCGCAttr());
6695 else if (T1->isVoidPointerType() || T2->isVoidPointerType())
6696 assert(Steps.size() == 1);
6697 else
6698 return QualType();
6699
6700 // Mismatched lifetime qualifiers never compatibly include each other.
6701 if (Q1.getObjCLifetime() == Q2.getObjCLifetime())
6702 Quals.setObjCLifetime(Q1.getObjCLifetime());
6703 else if (T1->isVoidPointerType() || T2->isVoidPointerType())
6704 assert(Steps.size() == 1);
6705 else
6706 return QualType();
6707
6708 Steps.back().Quals = Quals;
6709 if (Q1 != Quals || Q2 != Quals)
6710 NeedConstBefore = Steps.size() - 1;
6711 }
6712
6713 // FIXME: Can we unify the following with UnwrapSimilarTypes?
6714
6715 const ArrayType *Arr1, *Arr2;
6716 if ((Arr1 = Context.getAsArrayType(Composite1)) &&
6717 (Arr2 = Context.getAsArrayType(Composite2))) {
6718 auto *CAT1 = dyn_cast<ConstantArrayType>(Arr1);
6719 auto *CAT2 = dyn_cast<ConstantArrayType>(Arr2);
6720 if (CAT1 && CAT2 && CAT1->getSize() == CAT2->getSize()) {
6721 Composite1 = Arr1->getElementType();
6722 Composite2 = Arr2->getElementType();
6723 Steps.emplace_back(Step::Array, CAT1);
6724 continue;
6725 }
6726 bool IAT1 = isa<IncompleteArrayType>(Arr1);
6727 bool IAT2 = isa<IncompleteArrayType>(Arr2);
6728 if ((IAT1 && IAT2) ||
6729 (getLangOpts().CPlusPlus20 && (IAT1 != IAT2) &&
6730 ((bool)CAT1 != (bool)CAT2) &&
6731 (Steps.empty() || Steps.back().K != Step::Array))) {
6732 // In C++20 onwards, we can unify an array of N T with an array of
6733 // a different or unknown bound. But we can't form an array whose
6734 // element type is an array of unknown bound by doing so.
6735 Composite1 = Arr1->getElementType();
6736 Composite2 = Arr2->getElementType();
6737 Steps.emplace_back(Step::Array);
6738 if (CAT1 || CAT2)
6739 NeedConstBefore = Steps.size();
6740 continue;
6741 }
6742 }
6743
6744 const PointerType *Ptr1, *Ptr2;
6745 if ((Ptr1 = Composite1->getAs<PointerType>()) &&
6746 (Ptr2 = Composite2->getAs<PointerType>())) {
6747 Composite1 = Ptr1->getPointeeType();
6748 Composite2 = Ptr2->getPointeeType();
6749 Steps.emplace_back(Step::Pointer);
6750 continue;
6751 }
6752
6753 const ObjCObjectPointerType *ObjPtr1, *ObjPtr2;
6754 if ((ObjPtr1 = Composite1->getAs<ObjCObjectPointerType>()) &&
6755 (ObjPtr2 = Composite2->getAs<ObjCObjectPointerType>())) {
6756 Composite1 = ObjPtr1->getPointeeType();
6757 Composite2 = ObjPtr2->getPointeeType();
6758 Steps.emplace_back(Step::ObjCPointer);
6759 continue;
6760 }
6761
6762 const MemberPointerType *MemPtr1, *MemPtr2;
6763 if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) &&
6764 (MemPtr2 = Composite2->getAs<MemberPointerType>())) {
6765 Composite1 = MemPtr1->getPointeeType();
6766 Composite2 = MemPtr2->getPointeeType();
6767
6768 // At the top level, we can perform a base-to-derived pointer-to-member
6769 // conversion:
6770 //
6771 // - [...] where C1 is reference-related to C2 or C2 is
6772 // reference-related to C1
6773 //
6774 // (Note that the only kinds of reference-relatedness in scope here are
6775 // "same type or derived from".) At any other level, the class must
6776 // exactly match.
6777 const Type *Class = nullptr;
6778 QualType Cls1(MemPtr1->getClass(), 0);
6779 QualType Cls2(MemPtr2->getClass(), 0);
6780 if (Context.hasSameType(Cls1, Cls2))
6781 Class = MemPtr1->getClass();
6782 else if (Steps.empty())
6783 Class = IsDerivedFrom(Loc, Cls1, Cls2) ? MemPtr1->getClass() :
6784 IsDerivedFrom(Loc, Cls2, Cls1) ? MemPtr2->getClass() : nullptr;
6785 if (!Class)
6786 return QualType();
6787
6788 Steps.emplace_back(Step::MemberPointer, Class);
6789 continue;
6790 }
6791
6792 // Special case: at the top level, we can decompose an Objective-C pointer
6793 // and a 'cv void *'. Unify the qualifiers.
6794 if (Steps.empty() && ((Composite1->isVoidPointerType() &&
6795 Composite2->isObjCObjectPointerType()) ||
6796 (Composite1->isObjCObjectPointerType() &&
6797 Composite2->isVoidPointerType()))) {
6798 Composite1 = Composite1->getPointeeType();
6799 Composite2 = Composite2->getPointeeType();
6800 Steps.emplace_back(Step::Pointer);
6801 continue;
6802 }
6803
6804 // FIXME: block pointer types?
6805
6806 // Cannot unwrap any more types.
6807 break;
6808 }
6809
6810 // - if T1 or T2 is "pointer to noexcept function" and the other type is
6811 // "pointer to function", where the function types are otherwise the same,
6812 // "pointer to function";
6813 // - if T1 or T2 is "pointer to member of C1 of type function", the other
6814 // type is "pointer to member of C2 of type noexcept function", and C1
6815 // is reference-related to C2 or C2 is reference-related to C1, where
6816 // the function types are otherwise the same, "pointer to member of C2 of
6817 // type function" or "pointer to member of C1 of type function",
6818 // respectively;
6819 //
6820 // We also support 'noreturn' here, so as a Clang extension we generalize the
6821 // above to:
6822 //
6823 // - [Clang] If T1 and T2 are both of type "pointer to function" or
6824 // "pointer to member function" and the pointee types can be unified
6825 // by a function pointer conversion, that conversion is applied
6826 // before checking the following rules.
6827 //
6828 // We've already unwrapped down to the function types, and we want to merge
6829 // rather than just convert, so do this ourselves rather than calling
6830 // IsFunctionConversion.
6831 //
6832 // FIXME: In order to match the standard wording as closely as possible, we
6833 // currently only do this under a single level of pointers. Ideally, we would
6834 // allow this in general, and set NeedConstBefore to the relevant depth on
6835 // the side(s) where we changed anything. If we permit that, we should also
6836 // consider this conversion when determining type similarity and model it as
6837 // a qualification conversion.
6838 if (Steps.size() == 1) {
6839 if (auto *FPT1 = Composite1->getAs<FunctionProtoType>()) {
6840 if (auto *FPT2 = Composite2->getAs<FunctionProtoType>()) {
6841 FunctionProtoType::ExtProtoInfo EPI1 = FPT1->getExtProtoInfo();
6842 FunctionProtoType::ExtProtoInfo EPI2 = FPT2->getExtProtoInfo();
6843
6844 // The result is noreturn if both operands are.
6845 bool Noreturn =
6846 EPI1.ExtInfo.getNoReturn() && EPI2.ExtInfo.getNoReturn();
6847 EPI1.ExtInfo = EPI1.ExtInfo.withNoReturn(Noreturn);
6848 EPI2.ExtInfo = EPI2.ExtInfo.withNoReturn(Noreturn);
6849
6850 // The result is nothrow if both operands are.
6851 SmallVector<QualType, 8> ExceptionTypeStorage;
6852 EPI1.ExceptionSpec = EPI2.ExceptionSpec =
6853 mergeExceptionSpecs(*this, EPI1.ExceptionSpec, EPI2.ExceptionSpec,
6854 ExceptionTypeStorage);
6855
6856 Composite1 = Context.getFunctionType(FPT1->getReturnType(),
6857 FPT1->getParamTypes(), EPI1);
6858 Composite2 = Context.getFunctionType(FPT2->getReturnType(),
6859 FPT2->getParamTypes(), EPI2);
6860 }
6861 }
6862 }
6863
6864 // There are some more conversions we can perform under exactly one pointer.
6865 if (Steps.size() == 1 && Steps.front().K == Step::Pointer &&
6866 !Context.hasSameType(Composite1, Composite2)) {
6867 // - if T1 or T2 is "pointer to cv1 void" and the other type is
6868 // "pointer to cv2 T", where T is an object type or void,
6869 // "pointer to cv12 void", where cv12 is the union of cv1 and cv2;
6870 if (Composite1->isVoidType() && Composite2->isObjectType())
6871 Composite2 = Composite1;
6872 else if (Composite2->isVoidType() && Composite1->isObjectType())
6873 Composite1 = Composite2;
6874 // - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1
6875 // is reference-related to C2 or C2 is reference-related to C1 (8.6.3),
6876 // the cv-combined type of T1 and T2 or the cv-combined type of T2 and
6877 // T1, respectively;
6878 //
6879 // The "similar type" handling covers all of this except for the "T1 is a
6880 // base class of T2" case in the definition of reference-related.
6881 else if (IsDerivedFrom(Loc, Composite1, Composite2))
6882 Composite1 = Composite2;
6883 else if (IsDerivedFrom(Loc, Composite2, Composite1))
6884 Composite2 = Composite1;
6885 }
6886
6887 // At this point, either the inner types are the same or we have failed to
6888 // find a composite pointer type.
6889 if (!Context.hasSameType(Composite1, Composite2))
6890 return QualType();
6891
6892 // Per C++ [conv.qual]p3, add 'const' to every level before the last
6893 // differing qualifier.
6894 for (unsigned I = 0; I != NeedConstBefore; ++I)
6895 Steps[I].Quals.addConst();
6896
6897 // Rebuild the composite type.
6898 QualType Composite = Composite1;
6899 for (auto &S : llvm::reverse(Steps))
6900 Composite = S.rebuild(Context, Composite);
6901
6902 if (ConvertArgs) {
6903 // Convert the expressions to the composite pointer type.
6904 InitializedEntity Entity =
6905 InitializedEntity::InitializeTemporary(Composite);
6906 InitializationKind Kind =
6907 InitializationKind::CreateCopy(Loc, SourceLocation());
6908
6909 InitializationSequence E1ToC(*this, Entity, Kind, E1);
6910 if (!E1ToC)
6911 return QualType();
6912
6913 InitializationSequence E2ToC(*this, Entity, Kind, E2);
6914 if (!E2ToC)
6915 return QualType();
6916
6917 // FIXME: Let the caller know if these fail to avoid duplicate diagnostics.
6918 ExprResult E1Result = E1ToC.Perform(*this, Entity, Kind, E1);
6919 if (E1Result.isInvalid())
6920 return QualType();
6921 E1 = E1Result.get();
6922
6923 ExprResult E2Result = E2ToC.Perform(*this, Entity, Kind, E2);
6924 if (E2Result.isInvalid())
6925 return QualType();
6926 E2 = E2Result.get();
6927 }
6928
6929 return Composite;
6930 }
6931
MaybeBindToTemporary(Expr * E)6932 ExprResult Sema::MaybeBindToTemporary(Expr *E) {
6933 if (!E)
6934 return ExprError();
6935
6936 assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?");
6937
6938 // If the result is a glvalue, we shouldn't bind it.
6939 if (E->isGLValue())
6940 return E;
6941
6942 // In ARC, calls that return a retainable type can return retained,
6943 // in which case we have to insert a consuming cast.
6944 if (getLangOpts().ObjCAutoRefCount &&
6945 E->getType()->isObjCRetainableType()) {
6946
6947 bool ReturnsRetained;
6948
6949 // For actual calls, we compute this by examining the type of the
6950 // called value.
6951 if (CallExpr *Call = dyn_cast<CallExpr>(E)) {
6952 Expr *Callee = Call->getCallee()->IgnoreParens();
6953 QualType T = Callee->getType();
6954
6955 if (T == Context.BoundMemberTy) {
6956 // Handle pointer-to-members.
6957 if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee))
6958 T = BinOp->getRHS()->getType();
6959 else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee))
6960 T = Mem->getMemberDecl()->getType();
6961 }
6962
6963 if (const PointerType *Ptr = T->getAs<PointerType>())
6964 T = Ptr->getPointeeType();
6965 else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>())
6966 T = Ptr->getPointeeType();
6967 else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>())
6968 T = MemPtr->getPointeeType();
6969
6970 auto *FTy = T->castAs<FunctionType>();
6971 ReturnsRetained = FTy->getExtInfo().getProducesResult();
6972
6973 // ActOnStmtExpr arranges things so that StmtExprs of retainable
6974 // type always produce a +1 object.
6975 } else if (isa<StmtExpr>(E)) {
6976 ReturnsRetained = true;
6977
6978 // We hit this case with the lambda conversion-to-block optimization;
6979 // we don't want any extra casts here.
6980 } else if (isa<CastExpr>(E) &&
6981 isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) {
6982 return E;
6983
6984 // For message sends and property references, we try to find an
6985 // actual method. FIXME: we should infer retention by selector in
6986 // cases where we don't have an actual method.
6987 } else {
6988 ObjCMethodDecl *D = nullptr;
6989 if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) {
6990 D = Send->getMethodDecl();
6991 } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) {
6992 D = BoxedExpr->getBoxingMethod();
6993 } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) {
6994 // Don't do reclaims if we're using the zero-element array
6995 // constant.
6996 if (ArrayLit->getNumElements() == 0 &&
6997 Context.getLangOpts().ObjCRuntime.hasEmptyCollections())
6998 return E;
6999
7000 D = ArrayLit->getArrayWithObjectsMethod();
7001 } else if (ObjCDictionaryLiteral *DictLit
7002 = dyn_cast<ObjCDictionaryLiteral>(E)) {
7003 // Don't do reclaims if we're using the zero-element dictionary
7004 // constant.
7005 if (DictLit->getNumElements() == 0 &&
7006 Context.getLangOpts().ObjCRuntime.hasEmptyCollections())
7007 return E;
7008
7009 D = DictLit->getDictWithObjectsMethod();
7010 }
7011
7012 ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>());
7013
7014 // Don't do reclaims on performSelector calls; despite their
7015 // return type, the invoked method doesn't necessarily actually
7016 // return an object.
7017 if (!ReturnsRetained &&
7018 D && D->getMethodFamily() == OMF_performSelector)
7019 return E;
7020 }
7021
7022 // Don't reclaim an object of Class type.
7023 if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType())
7024 return E;
7025
7026 Cleanup.setExprNeedsCleanups(true);
7027
7028 CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject
7029 : CK_ARCReclaimReturnedObject);
7030 return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr,
7031 VK_PRValue, FPOptionsOverride());
7032 }
7033
7034 if (E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct)
7035 Cleanup.setExprNeedsCleanups(true);
7036
7037 if (!getLangOpts().CPlusPlus)
7038 return E;
7039
7040 // Search for the base element type (cf. ASTContext::getBaseElementType) with
7041 // a fast path for the common case that the type is directly a RecordType.
7042 const Type *T = Context.getCanonicalType(E->getType().getTypePtr());
7043 const RecordType *RT = nullptr;
7044 while (!RT) {
7045 switch (T->getTypeClass()) {
7046 case Type::Record:
7047 RT = cast<RecordType>(T);
7048 break;
7049 case Type::ConstantArray:
7050 case Type::IncompleteArray:
7051 case Type::VariableArray:
7052 case Type::DependentSizedArray:
7053 T = cast<ArrayType>(T)->getElementType().getTypePtr();
7054 break;
7055 default:
7056 return E;
7057 }
7058 }
7059
7060 // That should be enough to guarantee that this type is complete, if we're
7061 // not processing a decltype expression.
7062 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
7063 if (RD->isInvalidDecl() || RD->isDependentContext())
7064 return E;
7065
7066 bool IsDecltype = ExprEvalContexts.back().ExprContext ==
7067 ExpressionEvaluationContextRecord::EK_Decltype;
7068 CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD);
7069
7070 if (Destructor) {
7071 MarkFunctionReferenced(E->getExprLoc(), Destructor);
7072 CheckDestructorAccess(E->getExprLoc(), Destructor,
7073 PDiag(diag::err_access_dtor_temp)
7074 << E->getType());
7075 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
7076 return ExprError();
7077
7078 // If destructor is trivial, we can avoid the extra copy.
7079 if (Destructor->isTrivial())
7080 return E;
7081
7082 // We need a cleanup, but we don't need to remember the temporary.
7083 Cleanup.setExprNeedsCleanups(true);
7084 }
7085
7086 CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor);
7087 CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E);
7088
7089 if (IsDecltype)
7090 ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind);
7091
7092 return Bind;
7093 }
7094
7095 ExprResult
MaybeCreateExprWithCleanups(ExprResult SubExpr)7096 Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) {
7097 if (SubExpr.isInvalid())
7098 return ExprError();
7099
7100 return MaybeCreateExprWithCleanups(SubExpr.get());
7101 }
7102
MaybeCreateExprWithCleanups(Expr * SubExpr)7103 Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) {
7104 assert(SubExpr && "subexpression can't be null!");
7105
7106 CleanupVarDeclMarking();
7107
7108 unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects;
7109 assert(ExprCleanupObjects.size() >= FirstCleanup);
7110 assert(Cleanup.exprNeedsCleanups() ||
7111 ExprCleanupObjects.size() == FirstCleanup);
7112 if (!Cleanup.exprNeedsCleanups())
7113 return SubExpr;
7114
7115 auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup,
7116 ExprCleanupObjects.size() - FirstCleanup);
7117
7118 auto *E = ExprWithCleanups::Create(
7119 Context, SubExpr, Cleanup.cleanupsHaveSideEffects(), Cleanups);
7120 DiscardCleanupsInEvaluationContext();
7121
7122 return E;
7123 }
7124
MaybeCreateStmtWithCleanups(Stmt * SubStmt)7125 Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) {
7126 assert(SubStmt && "sub-statement can't be null!");
7127
7128 CleanupVarDeclMarking();
7129
7130 if (!Cleanup.exprNeedsCleanups())
7131 return SubStmt;
7132
7133 // FIXME: In order to attach the temporaries, wrap the statement into
7134 // a StmtExpr; currently this is only used for asm statements.
7135 // This is hacky, either create a new CXXStmtWithTemporaries statement or
7136 // a new AsmStmtWithTemporaries.
7137 CompoundStmt *CompStmt = CompoundStmt::Create(
7138 Context, SubStmt, SourceLocation(), SourceLocation());
7139 Expr *E = new (Context)
7140 StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), SourceLocation(),
7141 /*FIXME TemplateDepth=*/0);
7142 return MaybeCreateExprWithCleanups(E);
7143 }
7144
7145 /// Process the expression contained within a decltype. For such expressions,
7146 /// certain semantic checks on temporaries are delayed until this point, and
7147 /// are omitted for the 'topmost' call in the decltype expression. If the
7148 /// topmost call bound a temporary, strip that temporary off the expression.
ActOnDecltypeExpression(Expr * E)7149 ExprResult Sema::ActOnDecltypeExpression(Expr *E) {
7150 assert(ExprEvalContexts.back().ExprContext ==
7151 ExpressionEvaluationContextRecord::EK_Decltype &&
7152 "not in a decltype expression");
7153
7154 ExprResult Result = CheckPlaceholderExpr(E);
7155 if (Result.isInvalid())
7156 return ExprError();
7157 E = Result.get();
7158
7159 // C++11 [expr.call]p11:
7160 // If a function call is a prvalue of object type,
7161 // -- if the function call is either
7162 // -- the operand of a decltype-specifier, or
7163 // -- the right operand of a comma operator that is the operand of a
7164 // decltype-specifier,
7165 // a temporary object is not introduced for the prvalue.
7166
7167 // Recursively rebuild ParenExprs and comma expressions to strip out the
7168 // outermost CXXBindTemporaryExpr, if any.
7169 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
7170 ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr());
7171 if (SubExpr.isInvalid())
7172 return ExprError();
7173 if (SubExpr.get() == PE->getSubExpr())
7174 return E;
7175 return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get());
7176 }
7177 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
7178 if (BO->getOpcode() == BO_Comma) {
7179 ExprResult RHS = ActOnDecltypeExpression(BO->getRHS());
7180 if (RHS.isInvalid())
7181 return ExprError();
7182 if (RHS.get() == BO->getRHS())
7183 return E;
7184 return BinaryOperator::Create(Context, BO->getLHS(), RHS.get(), BO_Comma,
7185 BO->getType(), BO->getValueKind(),
7186 BO->getObjectKind(), BO->getOperatorLoc(),
7187 BO->getFPFeatures(getLangOpts()));
7188 }
7189 }
7190
7191 CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E);
7192 CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr())
7193 : nullptr;
7194 if (TopCall)
7195 E = TopCall;
7196 else
7197 TopBind = nullptr;
7198
7199 // Disable the special decltype handling now.
7200 ExprEvalContexts.back().ExprContext =
7201 ExpressionEvaluationContextRecord::EK_Other;
7202
7203 Result = CheckUnevaluatedOperand(E);
7204 if (Result.isInvalid())
7205 return ExprError();
7206 E = Result.get();
7207
7208 // In MS mode, don't perform any extra checking of call return types within a
7209 // decltype expression.
7210 if (getLangOpts().MSVCCompat)
7211 return E;
7212
7213 // Perform the semantic checks we delayed until this point.
7214 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size();
7215 I != N; ++I) {
7216 CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I];
7217 if (Call == TopCall)
7218 continue;
7219
7220 if (CheckCallReturnType(Call->getCallReturnType(Context),
7221 Call->getBeginLoc(), Call, Call->getDirectCallee()))
7222 return ExprError();
7223 }
7224
7225 // Now all relevant types are complete, check the destructors are accessible
7226 // and non-deleted, and annotate them on the temporaries.
7227 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size();
7228 I != N; ++I) {
7229 CXXBindTemporaryExpr *Bind =
7230 ExprEvalContexts.back().DelayedDecltypeBinds[I];
7231 if (Bind == TopBind)
7232 continue;
7233
7234 CXXTemporary *Temp = Bind->getTemporary();
7235
7236 CXXRecordDecl *RD =
7237 Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
7238 CXXDestructorDecl *Destructor = LookupDestructor(RD);
7239 Temp->setDestructor(Destructor);
7240
7241 MarkFunctionReferenced(Bind->getExprLoc(), Destructor);
7242 CheckDestructorAccess(Bind->getExprLoc(), Destructor,
7243 PDiag(diag::err_access_dtor_temp)
7244 << Bind->getType());
7245 if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc()))
7246 return ExprError();
7247
7248 // We need a cleanup, but we don't need to remember the temporary.
7249 Cleanup.setExprNeedsCleanups(true);
7250 }
7251
7252 // Possibly strip off the top CXXBindTemporaryExpr.
7253 return E;
7254 }
7255
7256 /// Note a set of 'operator->' functions that were used for a member access.
noteOperatorArrows(Sema & S,ArrayRef<FunctionDecl * > OperatorArrows)7257 static void noteOperatorArrows(Sema &S,
7258 ArrayRef<FunctionDecl *> OperatorArrows) {
7259 unsigned SkipStart = OperatorArrows.size(), SkipCount = 0;
7260 // FIXME: Make this configurable?
7261 unsigned Limit = 9;
7262 if (OperatorArrows.size() > Limit) {
7263 // Produce Limit-1 normal notes and one 'skipping' note.
7264 SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2;
7265 SkipCount = OperatorArrows.size() - (Limit - 1);
7266 }
7267
7268 for (unsigned I = 0; I < OperatorArrows.size(); /**/) {
7269 if (I == SkipStart) {
7270 S.Diag(OperatorArrows[I]->getLocation(),
7271 diag::note_operator_arrows_suppressed)
7272 << SkipCount;
7273 I += SkipCount;
7274 } else {
7275 S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here)
7276 << OperatorArrows[I]->getCallResultType();
7277 ++I;
7278 }
7279 }
7280 }
7281
ActOnStartCXXMemberReference(Scope * S,Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,ParsedType & ObjectType,bool & MayBePseudoDestructor)7282 ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
7283 SourceLocation OpLoc,
7284 tok::TokenKind OpKind,
7285 ParsedType &ObjectType,
7286 bool &MayBePseudoDestructor) {
7287 // Since this might be a postfix expression, get rid of ParenListExprs.
7288 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base);
7289 if (Result.isInvalid()) return ExprError();
7290 Base = Result.get();
7291
7292 Result = CheckPlaceholderExpr(Base);
7293 if (Result.isInvalid()) return ExprError();
7294 Base = Result.get();
7295
7296 QualType BaseType = Base->getType();
7297 MayBePseudoDestructor = false;
7298 if (BaseType->isDependentType()) {
7299 // If we have a pointer to a dependent type and are using the -> operator,
7300 // the object type is the type that the pointer points to. We might still
7301 // have enough information about that type to do something useful.
7302 if (OpKind == tok::arrow)
7303 if (const PointerType *Ptr = BaseType->getAs<PointerType>())
7304 BaseType = Ptr->getPointeeType();
7305
7306 ObjectType = ParsedType::make(BaseType);
7307 MayBePseudoDestructor = true;
7308 return Base;
7309 }
7310
7311 // C++ [over.match.oper]p8:
7312 // [...] When operator->returns, the operator-> is applied to the value
7313 // returned, with the original second operand.
7314 if (OpKind == tok::arrow) {
7315 QualType StartingType = BaseType;
7316 bool NoArrowOperatorFound = false;
7317 bool FirstIteration = true;
7318 FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext);
7319 // The set of types we've considered so far.
7320 llvm::SmallPtrSet<CanQualType,8> CTypes;
7321 SmallVector<FunctionDecl*, 8> OperatorArrows;
7322 CTypes.insert(Context.getCanonicalType(BaseType));
7323
7324 while (BaseType->isRecordType()) {
7325 if (OperatorArrows.size() >= getLangOpts().ArrowDepth) {
7326 Diag(OpLoc, diag::err_operator_arrow_depth_exceeded)
7327 << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange();
7328 noteOperatorArrows(*this, OperatorArrows);
7329 Diag(OpLoc, diag::note_operator_arrow_depth)
7330 << getLangOpts().ArrowDepth;
7331 return ExprError();
7332 }
7333
7334 Result = BuildOverloadedArrowExpr(
7335 S, Base, OpLoc,
7336 // When in a template specialization and on the first loop iteration,
7337 // potentially give the default diagnostic (with the fixit in a
7338 // separate note) instead of having the error reported back to here
7339 // and giving a diagnostic with a fixit attached to the error itself.
7340 (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization())
7341 ? nullptr
7342 : &NoArrowOperatorFound);
7343 if (Result.isInvalid()) {
7344 if (NoArrowOperatorFound) {
7345 if (FirstIteration) {
7346 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
7347 << BaseType << 1 << Base->getSourceRange()
7348 << FixItHint::CreateReplacement(OpLoc, ".");
7349 OpKind = tok::period;
7350 break;
7351 }
7352 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
7353 << BaseType << Base->getSourceRange();
7354 CallExpr *CE = dyn_cast<CallExpr>(Base);
7355 if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) {
7356 Diag(CD->getBeginLoc(),
7357 diag::note_member_reference_arrow_from_operator_arrow);
7358 }
7359 }
7360 return ExprError();
7361 }
7362 Base = Result.get();
7363 if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base))
7364 OperatorArrows.push_back(OpCall->getDirectCallee());
7365 BaseType = Base->getType();
7366 CanQualType CBaseType = Context.getCanonicalType(BaseType);
7367 if (!CTypes.insert(CBaseType).second) {
7368 Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType;
7369 noteOperatorArrows(*this, OperatorArrows);
7370 return ExprError();
7371 }
7372 FirstIteration = false;
7373 }
7374
7375 if (OpKind == tok::arrow) {
7376 if (BaseType->isPointerType())
7377 BaseType = BaseType->getPointeeType();
7378 else if (auto *AT = Context.getAsArrayType(BaseType))
7379 BaseType = AT->getElementType();
7380 }
7381 }
7382
7383 // Objective-C properties allow "." access on Objective-C pointer types,
7384 // so adjust the base type to the object type itself.
7385 if (BaseType->isObjCObjectPointerType())
7386 BaseType = BaseType->getPointeeType();
7387
7388 // C++ [basic.lookup.classref]p2:
7389 // [...] If the type of the object expression is of pointer to scalar
7390 // type, the unqualified-id is looked up in the context of the complete
7391 // postfix-expression.
7392 //
7393 // This also indicates that we could be parsing a pseudo-destructor-name.
7394 // Note that Objective-C class and object types can be pseudo-destructor
7395 // expressions or normal member (ivar or property) access expressions, and
7396 // it's legal for the type to be incomplete if this is a pseudo-destructor
7397 // call. We'll do more incomplete-type checks later in the lookup process,
7398 // so just skip this check for ObjC types.
7399 if (!BaseType->isRecordType()) {
7400 ObjectType = ParsedType::make(BaseType);
7401 MayBePseudoDestructor = true;
7402 return Base;
7403 }
7404
7405 // The object type must be complete (or dependent), or
7406 // C++11 [expr.prim.general]p3:
7407 // Unlike the object expression in other contexts, *this is not required to
7408 // be of complete type for purposes of class member access (5.2.5) outside
7409 // the member function body.
7410 if (!BaseType->isDependentType() &&
7411 !isThisOutsideMemberFunctionBody(BaseType) &&
7412 RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access))
7413 return ExprError();
7414
7415 // C++ [basic.lookup.classref]p2:
7416 // If the id-expression in a class member access (5.2.5) is an
7417 // unqualified-id, and the type of the object expression is of a class
7418 // type C (or of pointer to a class type C), the unqualified-id is looked
7419 // up in the scope of class C. [...]
7420 ObjectType = ParsedType::make(BaseType);
7421 return Base;
7422 }
7423
CheckArrow(Sema & S,QualType & ObjectType,Expr * & Base,tok::TokenKind & OpKind,SourceLocation OpLoc)7424 static bool CheckArrow(Sema &S, QualType &ObjectType, Expr *&Base,
7425 tok::TokenKind &OpKind, SourceLocation OpLoc) {
7426 if (Base->hasPlaceholderType()) {
7427 ExprResult result = S.CheckPlaceholderExpr(Base);
7428 if (result.isInvalid()) return true;
7429 Base = result.get();
7430 }
7431 ObjectType = Base->getType();
7432
7433 // C++ [expr.pseudo]p2:
7434 // The left-hand side of the dot operator shall be of scalar type. The
7435 // left-hand side of the arrow operator shall be of pointer to scalar type.
7436 // This scalar type is the object type.
7437 // Note that this is rather different from the normal handling for the
7438 // arrow operator.
7439 if (OpKind == tok::arrow) {
7440 // The operator requires a prvalue, so perform lvalue conversions.
7441 // Only do this if we might plausibly end with a pointer, as otherwise
7442 // this was likely to be intended to be a '.'.
7443 if (ObjectType->isPointerType() || ObjectType->isArrayType() ||
7444 ObjectType->isFunctionType()) {
7445 ExprResult BaseResult = S.DefaultFunctionArrayLvalueConversion(Base);
7446 if (BaseResult.isInvalid())
7447 return true;
7448 Base = BaseResult.get();
7449 ObjectType = Base->getType();
7450 }
7451
7452 if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) {
7453 ObjectType = Ptr->getPointeeType();
7454 } else if (!Base->isTypeDependent()) {
7455 // The user wrote "p->" when they probably meant "p."; fix it.
7456 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
7457 << ObjectType << true
7458 << FixItHint::CreateReplacement(OpLoc, ".");
7459 if (S.isSFINAEContext())
7460 return true;
7461
7462 OpKind = tok::period;
7463 }
7464 }
7465
7466 return false;
7467 }
7468
7469 /// Check if it's ok to try and recover dot pseudo destructor calls on
7470 /// pointer objects.
7471 static bool
canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema & SemaRef,QualType DestructedType)7472 canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema &SemaRef,
7473 QualType DestructedType) {
7474 // If this is a record type, check if its destructor is callable.
7475 if (auto *RD = DestructedType->getAsCXXRecordDecl()) {
7476 if (RD->hasDefinition())
7477 if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD))
7478 return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false);
7479 return false;
7480 }
7481
7482 // Otherwise, check if it's a type for which it's valid to use a pseudo-dtor.
7483 return DestructedType->isDependentType() || DestructedType->isScalarType() ||
7484 DestructedType->isVectorType();
7485 }
7486
BuildPseudoDestructorExpr(Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,const CXXScopeSpec & SS,TypeSourceInfo * ScopeTypeInfo,SourceLocation CCLoc,SourceLocation TildeLoc,PseudoDestructorTypeStorage Destructed)7487 ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base,
7488 SourceLocation OpLoc,
7489 tok::TokenKind OpKind,
7490 const CXXScopeSpec &SS,
7491 TypeSourceInfo *ScopeTypeInfo,
7492 SourceLocation CCLoc,
7493 SourceLocation TildeLoc,
7494 PseudoDestructorTypeStorage Destructed) {
7495 TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo();
7496
7497 QualType ObjectType;
7498 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
7499 return ExprError();
7500
7501 if (!ObjectType->isDependentType() && !ObjectType->isScalarType() &&
7502 !ObjectType->isVectorType()) {
7503 if (getLangOpts().MSVCCompat && ObjectType->isVoidType())
7504 Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange();
7505 else {
7506 Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar)
7507 << ObjectType << Base->getSourceRange();
7508 return ExprError();
7509 }
7510 }
7511
7512 // C++ [expr.pseudo]p2:
7513 // [...] The cv-unqualified versions of the object type and of the type
7514 // designated by the pseudo-destructor-name shall be the same type.
7515 if (DestructedTypeInfo) {
7516 QualType DestructedType = DestructedTypeInfo->getType();
7517 SourceLocation DestructedTypeStart
7518 = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin();
7519 if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) {
7520 if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) {
7521 // Detect dot pseudo destructor calls on pointer objects, e.g.:
7522 // Foo *foo;
7523 // foo.~Foo();
7524 if (OpKind == tok::period && ObjectType->isPointerType() &&
7525 Context.hasSameUnqualifiedType(DestructedType,
7526 ObjectType->getPointeeType())) {
7527 auto Diagnostic =
7528 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
7529 << ObjectType << /*IsArrow=*/0 << Base->getSourceRange();
7530
7531 // Issue a fixit only when the destructor is valid.
7532 if (canRecoverDotPseudoDestructorCallsOnPointerObjects(
7533 *this, DestructedType))
7534 Diagnostic << FixItHint::CreateReplacement(OpLoc, "->");
7535
7536 // Recover by setting the object type to the destructed type and the
7537 // operator to '->'.
7538 ObjectType = DestructedType;
7539 OpKind = tok::arrow;
7540 } else {
7541 Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch)
7542 << ObjectType << DestructedType << Base->getSourceRange()
7543 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange();
7544
7545 // Recover by setting the destructed type to the object type.
7546 DestructedType = ObjectType;
7547 DestructedTypeInfo =
7548 Context.getTrivialTypeSourceInfo(ObjectType, DestructedTypeStart);
7549 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
7550 }
7551 } else if (DestructedType.getObjCLifetime() !=
7552 ObjectType.getObjCLifetime()) {
7553
7554 if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) {
7555 // Okay: just pretend that the user provided the correctly-qualified
7556 // type.
7557 } else {
7558 Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals)
7559 << ObjectType << DestructedType << Base->getSourceRange()
7560 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange();
7561 }
7562
7563 // Recover by setting the destructed type to the object type.
7564 DestructedType = ObjectType;
7565 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType,
7566 DestructedTypeStart);
7567 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
7568 }
7569 }
7570 }
7571
7572 // C++ [expr.pseudo]p2:
7573 // [...] Furthermore, the two type-names in a pseudo-destructor-name of the
7574 // form
7575 //
7576 // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name
7577 //
7578 // shall designate the same scalar type.
7579 if (ScopeTypeInfo) {
7580 QualType ScopeType = ScopeTypeInfo->getType();
7581 if (!ScopeType->isDependentType() && !ObjectType->isDependentType() &&
7582 !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) {
7583
7584 Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(),
7585 diag::err_pseudo_dtor_type_mismatch)
7586 << ObjectType << ScopeType << Base->getSourceRange()
7587 << ScopeTypeInfo->getTypeLoc().getLocalSourceRange();
7588
7589 ScopeType = QualType();
7590 ScopeTypeInfo = nullptr;
7591 }
7592 }
7593
7594 Expr *Result
7595 = new (Context) CXXPseudoDestructorExpr(Context, Base,
7596 OpKind == tok::arrow, OpLoc,
7597 SS.getWithLocInContext(Context),
7598 ScopeTypeInfo,
7599 CCLoc,
7600 TildeLoc,
7601 Destructed);
7602
7603 return Result;
7604 }
7605
ActOnPseudoDestructorExpr(Scope * S,Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,CXXScopeSpec & SS,UnqualifiedId & FirstTypeName,SourceLocation CCLoc,SourceLocation TildeLoc,UnqualifiedId & SecondTypeName)7606 ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
7607 SourceLocation OpLoc,
7608 tok::TokenKind OpKind,
7609 CXXScopeSpec &SS,
7610 UnqualifiedId &FirstTypeName,
7611 SourceLocation CCLoc,
7612 SourceLocation TildeLoc,
7613 UnqualifiedId &SecondTypeName) {
7614 assert((FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||
7615 FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) &&
7616 "Invalid first type name in pseudo-destructor");
7617 assert((SecondTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||
7618 SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) &&
7619 "Invalid second type name in pseudo-destructor");
7620
7621 QualType ObjectType;
7622 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
7623 return ExprError();
7624
7625 // Compute the object type that we should use for name lookup purposes. Only
7626 // record types and dependent types matter.
7627 ParsedType ObjectTypePtrForLookup;
7628 if (!SS.isSet()) {
7629 if (ObjectType->isRecordType())
7630 ObjectTypePtrForLookup = ParsedType::make(ObjectType);
7631 else if (ObjectType->isDependentType())
7632 ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy);
7633 }
7634
7635 // Convert the name of the type being destructed (following the ~) into a
7636 // type (with source-location information).
7637 QualType DestructedType;
7638 TypeSourceInfo *DestructedTypeInfo = nullptr;
7639 PseudoDestructorTypeStorage Destructed;
7640 if (SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) {
7641 ParsedType T = getTypeName(*SecondTypeName.Identifier,
7642 SecondTypeName.StartLocation,
7643 S, &SS, true, false, ObjectTypePtrForLookup,
7644 /*IsCtorOrDtorName*/true);
7645 if (!T &&
7646 ((SS.isSet() && !computeDeclContext(SS, false)) ||
7647 (!SS.isSet() && ObjectType->isDependentType()))) {
7648 // The name of the type being destroyed is a dependent name, and we
7649 // couldn't find anything useful in scope. Just store the identifier and
7650 // it's location, and we'll perform (qualified) name lookup again at
7651 // template instantiation time.
7652 Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier,
7653 SecondTypeName.StartLocation);
7654 } else if (!T) {
7655 Diag(SecondTypeName.StartLocation,
7656 diag::err_pseudo_dtor_destructor_non_type)
7657 << SecondTypeName.Identifier << ObjectType;
7658 if (isSFINAEContext())
7659 return ExprError();
7660
7661 // Recover by assuming we had the right type all along.
7662 DestructedType = ObjectType;
7663 } else
7664 DestructedType = GetTypeFromParser(T, &DestructedTypeInfo);
7665 } else {
7666 // Resolve the template-id to a type.
7667 TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId;
7668 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
7669 TemplateId->NumArgs);
7670 TypeResult T = ActOnTemplateIdType(S,
7671 SS,
7672 TemplateId->TemplateKWLoc,
7673 TemplateId->Template,
7674 TemplateId->Name,
7675 TemplateId->TemplateNameLoc,
7676 TemplateId->LAngleLoc,
7677 TemplateArgsPtr,
7678 TemplateId->RAngleLoc,
7679 /*IsCtorOrDtorName*/true);
7680 if (T.isInvalid() || !T.get()) {
7681 // Recover by assuming we had the right type all along.
7682 DestructedType = ObjectType;
7683 } else
7684 DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo);
7685 }
7686
7687 // If we've performed some kind of recovery, (re-)build the type source
7688 // information.
7689 if (!DestructedType.isNull()) {
7690 if (!DestructedTypeInfo)
7691 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType,
7692 SecondTypeName.StartLocation);
7693 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
7694 }
7695
7696 // Convert the name of the scope type (the type prior to '::') into a type.
7697 TypeSourceInfo *ScopeTypeInfo = nullptr;
7698 QualType ScopeType;
7699 if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||
7700 FirstTypeName.Identifier) {
7701 if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) {
7702 ParsedType T = getTypeName(*FirstTypeName.Identifier,
7703 FirstTypeName.StartLocation,
7704 S, &SS, true, false, ObjectTypePtrForLookup,
7705 /*IsCtorOrDtorName*/true);
7706 if (!T) {
7707 Diag(FirstTypeName.StartLocation,
7708 diag::err_pseudo_dtor_destructor_non_type)
7709 << FirstTypeName.Identifier << ObjectType;
7710
7711 if (isSFINAEContext())
7712 return ExprError();
7713
7714 // Just drop this type. It's unnecessary anyway.
7715 ScopeType = QualType();
7716 } else
7717 ScopeType = GetTypeFromParser(T, &ScopeTypeInfo);
7718 } else {
7719 // Resolve the template-id to a type.
7720 TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId;
7721 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
7722 TemplateId->NumArgs);
7723 TypeResult T = ActOnTemplateIdType(S,
7724 SS,
7725 TemplateId->TemplateKWLoc,
7726 TemplateId->Template,
7727 TemplateId->Name,
7728 TemplateId->TemplateNameLoc,
7729 TemplateId->LAngleLoc,
7730 TemplateArgsPtr,
7731 TemplateId->RAngleLoc,
7732 /*IsCtorOrDtorName*/true);
7733 if (T.isInvalid() || !T.get()) {
7734 // Recover by dropping this type.
7735 ScopeType = QualType();
7736 } else
7737 ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo);
7738 }
7739 }
7740
7741 if (!ScopeType.isNull() && !ScopeTypeInfo)
7742 ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType,
7743 FirstTypeName.StartLocation);
7744
7745
7746 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS,
7747 ScopeTypeInfo, CCLoc, TildeLoc,
7748 Destructed);
7749 }
7750
ActOnPseudoDestructorExpr(Scope * S,Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,SourceLocation TildeLoc,const DeclSpec & DS)7751 ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
7752 SourceLocation OpLoc,
7753 tok::TokenKind OpKind,
7754 SourceLocation TildeLoc,
7755 const DeclSpec& DS) {
7756 QualType ObjectType;
7757 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
7758 return ExprError();
7759
7760 if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) {
7761 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
7762 return true;
7763 }
7764
7765 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(),
7766 false);
7767
7768 TypeLocBuilder TLB;
7769 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
7770 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
7771 TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T);
7772 PseudoDestructorTypeStorage Destructed(DestructedTypeInfo);
7773
7774 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(),
7775 nullptr, SourceLocation(), TildeLoc,
7776 Destructed);
7777 }
7778
BuildCXXMemberCallExpr(Expr * E,NamedDecl * FoundDecl,CXXConversionDecl * Method,bool HadMultipleCandidates)7779 ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
7780 CXXConversionDecl *Method,
7781 bool HadMultipleCandidates) {
7782 // Convert the expression to match the conversion function's implicit object
7783 // parameter.
7784 ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr,
7785 FoundDecl, Method);
7786 if (Exp.isInvalid())
7787 return true;
7788
7789 if (Method->getParent()->isLambda() &&
7790 Method->getConversionType()->isBlockPointerType()) {
7791 // This is a lambda conversion to block pointer; check if the argument
7792 // was a LambdaExpr.
7793 Expr *SubE = E;
7794 CastExpr *CE = dyn_cast<CastExpr>(SubE);
7795 if (CE && CE->getCastKind() == CK_NoOp)
7796 SubE = CE->getSubExpr();
7797 SubE = SubE->IgnoreParens();
7798 if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE))
7799 SubE = BE->getSubExpr();
7800 if (isa<LambdaExpr>(SubE)) {
7801 // For the conversion to block pointer on a lambda expression, we
7802 // construct a special BlockLiteral instead; this doesn't really make
7803 // a difference in ARC, but outside of ARC the resulting block literal
7804 // follows the normal lifetime rules for block literals instead of being
7805 // autoreleased.
7806 PushExpressionEvaluationContext(
7807 ExpressionEvaluationContext::PotentiallyEvaluated);
7808 ExprResult BlockExp = BuildBlockForLambdaConversion(
7809 Exp.get()->getExprLoc(), Exp.get()->getExprLoc(), Method, Exp.get());
7810 PopExpressionEvaluationContext();
7811
7812 // FIXME: This note should be produced by a CodeSynthesisContext.
7813 if (BlockExp.isInvalid())
7814 Diag(Exp.get()->getExprLoc(), diag::note_lambda_to_block_conv);
7815 return BlockExp;
7816 }
7817 }
7818
7819 MemberExpr *ME =
7820 BuildMemberExpr(Exp.get(), /*IsArrow=*/false, SourceLocation(),
7821 NestedNameSpecifierLoc(), SourceLocation(), Method,
7822 DeclAccessPair::make(FoundDecl, FoundDecl->getAccess()),
7823 HadMultipleCandidates, DeclarationNameInfo(),
7824 Context.BoundMemberTy, VK_PRValue, OK_Ordinary);
7825
7826 QualType ResultType = Method->getReturnType();
7827 ExprValueKind VK = Expr::getValueKindForType(ResultType);
7828 ResultType = ResultType.getNonLValueExprType(Context);
7829
7830 CXXMemberCallExpr *CE = CXXMemberCallExpr::Create(
7831 Context, ME, /*Args=*/{}, ResultType, VK, Exp.get()->getEndLoc(),
7832 CurFPFeatureOverrides());
7833
7834 if (CheckFunctionCall(Method, CE,
7835 Method->getType()->castAs<FunctionProtoType>()))
7836 return ExprError();
7837
7838 return CheckForImmediateInvocation(CE, CE->getMethodDecl());
7839 }
7840
BuildCXXNoexceptExpr(SourceLocation KeyLoc,Expr * Operand,SourceLocation RParen)7841 ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
7842 SourceLocation RParen) {
7843 // If the operand is an unresolved lookup expression, the expression is ill-
7844 // formed per [over.over]p1, because overloaded function names cannot be used
7845 // without arguments except in explicit contexts.
7846 ExprResult R = CheckPlaceholderExpr(Operand);
7847 if (R.isInvalid())
7848 return R;
7849
7850 R = CheckUnevaluatedOperand(R.get());
7851 if (R.isInvalid())
7852 return ExprError();
7853
7854 Operand = R.get();
7855
7856 if (!inTemplateInstantiation() && !Operand->isInstantiationDependent() &&
7857 Operand->HasSideEffects(Context, false)) {
7858 // The expression operand for noexcept is in an unevaluated expression
7859 // context, so side effects could result in unintended consequences.
7860 Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context);
7861 }
7862
7863 CanThrowResult CanThrow = canThrow(Operand);
7864 return new (Context)
7865 CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen);
7866 }
7867
ActOnNoexceptExpr(SourceLocation KeyLoc,SourceLocation,Expr * Operand,SourceLocation RParen)7868 ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation,
7869 Expr *Operand, SourceLocation RParen) {
7870 return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen);
7871 }
7872
MaybeDecrementCount(Expr * E,llvm::DenseMap<const VarDecl *,int> & RefsMinusAssignments)7873 static void MaybeDecrementCount(
7874 Expr *E, llvm::DenseMap<const VarDecl *, int> &RefsMinusAssignments) {
7875 DeclRefExpr *LHS = nullptr;
7876 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
7877 if (BO->getLHS()->getType()->isDependentType() ||
7878 BO->getRHS()->getType()->isDependentType()) {
7879 if (BO->getOpcode() != BO_Assign)
7880 return;
7881 } else if (!BO->isAssignmentOp())
7882 return;
7883 LHS = dyn_cast<DeclRefExpr>(BO->getLHS());
7884 } else if (CXXOperatorCallExpr *COCE = dyn_cast<CXXOperatorCallExpr>(E)) {
7885 if (COCE->getOperator() != OO_Equal)
7886 return;
7887 LHS = dyn_cast<DeclRefExpr>(COCE->getArg(0));
7888 }
7889 if (!LHS)
7890 return;
7891 VarDecl *VD = dyn_cast<VarDecl>(LHS->getDecl());
7892 if (!VD)
7893 return;
7894 auto iter = RefsMinusAssignments.find(VD);
7895 if (iter == RefsMinusAssignments.end())
7896 return;
7897 iter->getSecond()--;
7898 }
7899
7900 /// Perform the conversions required for an expression used in a
7901 /// context that ignores the result.
IgnoredValueConversions(Expr * E)7902 ExprResult Sema::IgnoredValueConversions(Expr *E) {
7903 MaybeDecrementCount(E, RefsMinusAssignments);
7904
7905 if (E->hasPlaceholderType()) {
7906 ExprResult result = CheckPlaceholderExpr(E);
7907 if (result.isInvalid()) return E;
7908 E = result.get();
7909 }
7910
7911 // C99 6.3.2.1:
7912 // [Except in specific positions,] an lvalue that does not have
7913 // array type is converted to the value stored in the
7914 // designated object (and is no longer an lvalue).
7915 if (E->isPRValue()) {
7916 // In C, function designators (i.e. expressions of function type)
7917 // are r-values, but we still want to do function-to-pointer decay
7918 // on them. This is both technically correct and convenient for
7919 // some clients.
7920 if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType())
7921 return DefaultFunctionArrayConversion(E);
7922
7923 return E;
7924 }
7925
7926 if (getLangOpts().CPlusPlus) {
7927 // The C++11 standard defines the notion of a discarded-value expression;
7928 // normally, we don't need to do anything to handle it, but if it is a
7929 // volatile lvalue with a special form, we perform an lvalue-to-rvalue
7930 // conversion.
7931 if (getLangOpts().CPlusPlus11 && E->isReadIfDiscardedInCPlusPlus11()) {
7932 ExprResult Res = DefaultLvalueConversion(E);
7933 if (Res.isInvalid())
7934 return E;
7935 E = Res.get();
7936 } else {
7937 // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if
7938 // it occurs as a discarded-value expression.
7939 CheckUnusedVolatileAssignment(E);
7940 }
7941
7942 // C++1z:
7943 // If the expression is a prvalue after this optional conversion, the
7944 // temporary materialization conversion is applied.
7945 //
7946 // We skip this step: IR generation is able to synthesize the storage for
7947 // itself in the aggregate case, and adding the extra node to the AST is
7948 // just clutter.
7949 // FIXME: We don't emit lifetime markers for the temporaries due to this.
7950 // FIXME: Do any other AST consumers care about this?
7951 return E;
7952 }
7953
7954 // GCC seems to also exclude expressions of incomplete enum type.
7955 if (const EnumType *T = E->getType()->getAs<EnumType>()) {
7956 if (!T->getDecl()->isComplete()) {
7957 // FIXME: stupid workaround for a codegen bug!
7958 E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get();
7959 return E;
7960 }
7961 }
7962
7963 ExprResult Res = DefaultFunctionArrayLvalueConversion(E);
7964 if (Res.isInvalid())
7965 return E;
7966 E = Res.get();
7967
7968 if (!E->getType()->isVoidType())
7969 RequireCompleteType(E->getExprLoc(), E->getType(),
7970 diag::err_incomplete_type);
7971 return E;
7972 }
7973
CheckUnevaluatedOperand(Expr * E)7974 ExprResult Sema::CheckUnevaluatedOperand(Expr *E) {
7975 // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if
7976 // it occurs as an unevaluated operand.
7977 CheckUnusedVolatileAssignment(E);
7978
7979 return E;
7980 }
7981
7982 // If we can unambiguously determine whether Var can never be used
7983 // in a constant expression, return true.
7984 // - if the variable and its initializer are non-dependent, then
7985 // we can unambiguously check if the variable is a constant expression.
7986 // - if the initializer is not value dependent - we can determine whether
7987 // it can be used to initialize a constant expression. If Init can not
7988 // be used to initialize a constant expression we conclude that Var can
7989 // never be a constant expression.
7990 // - FXIME: if the initializer is dependent, we can still do some analysis and
7991 // identify certain cases unambiguously as non-const by using a Visitor:
7992 // - such as those that involve odr-use of a ParmVarDecl, involve a new
7993 // delete, lambda-expr, dynamic-cast, reinterpret-cast etc...
VariableCanNeverBeAConstantExpression(VarDecl * Var,ASTContext & Context)7994 static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var,
7995 ASTContext &Context) {
7996 if (isa<ParmVarDecl>(Var)) return true;
7997 const VarDecl *DefVD = nullptr;
7998
7999 // If there is no initializer - this can not be a constant expression.
8000 if (!Var->getAnyInitializer(DefVD)) return true;
8001 assert(DefVD);
8002 if (DefVD->isWeak()) return false;
8003 EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt();
8004
8005 Expr *Init = cast<Expr>(Eval->Value);
8006
8007 if (Var->getType()->isDependentType() || Init->isValueDependent()) {
8008 // FIXME: Teach the constant evaluator to deal with the non-dependent parts
8009 // of value-dependent expressions, and use it here to determine whether the
8010 // initializer is a potential constant expression.
8011 return false;
8012 }
8013
8014 return !Var->isUsableInConstantExpressions(Context);
8015 }
8016
8017 /// Check if the current lambda has any potential captures
8018 /// that must be captured by any of its enclosing lambdas that are ready to
8019 /// capture. If there is a lambda that can capture a nested
8020 /// potential-capture, go ahead and do so. Also, check to see if any
8021 /// variables are uncaptureable or do not involve an odr-use so do not
8022 /// need to be captured.
8023
CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(Expr * const FE,LambdaScopeInfo * const CurrentLSI,Sema & S)8024 static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
8025 Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) {
8026
8027 assert(!S.isUnevaluatedContext());
8028 assert(S.CurContext->isDependentContext());
8029 #ifndef NDEBUG
8030 DeclContext *DC = S.CurContext;
8031 while (DC && isa<CapturedDecl>(DC))
8032 DC = DC->getParent();
8033 assert(
8034 CurrentLSI->CallOperator == DC &&
8035 "The current call operator must be synchronized with Sema's CurContext");
8036 #endif // NDEBUG
8037
8038 const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent();
8039
8040 // All the potentially captureable variables in the current nested
8041 // lambda (within a generic outer lambda), must be captured by an
8042 // outer lambda that is enclosed within a non-dependent context.
8043 CurrentLSI->visitPotentialCaptures([&] (VarDecl *Var, Expr *VarExpr) {
8044 // If the variable is clearly identified as non-odr-used and the full
8045 // expression is not instantiation dependent, only then do we not
8046 // need to check enclosing lambda's for speculative captures.
8047 // For e.g.:
8048 // Even though 'x' is not odr-used, it should be captured.
8049 // int test() {
8050 // const int x = 10;
8051 // auto L = [=](auto a) {
8052 // (void) +x + a;
8053 // };
8054 // }
8055 if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) &&
8056 !IsFullExprInstantiationDependent)
8057 return;
8058
8059 // If we have a capture-capable lambda for the variable, go ahead and
8060 // capture the variable in that lambda (and all its enclosing lambdas).
8061 if (const Optional<unsigned> Index =
8062 getStackIndexOfNearestEnclosingCaptureCapableLambda(
8063 S.FunctionScopes, Var, S))
8064 S.MarkCaptureUsedInEnclosingContext(Var, VarExpr->getExprLoc(),
8065 Index.getValue());
8066 const bool IsVarNeverAConstantExpression =
8067 VariableCanNeverBeAConstantExpression(Var, S.Context);
8068 if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) {
8069 // This full expression is not instantiation dependent or the variable
8070 // can not be used in a constant expression - which means
8071 // this variable must be odr-used here, so diagnose a
8072 // capture violation early, if the variable is un-captureable.
8073 // This is purely for diagnosing errors early. Otherwise, this
8074 // error would get diagnosed when the lambda becomes capture ready.
8075 QualType CaptureType, DeclRefType;
8076 SourceLocation ExprLoc = VarExpr->getExprLoc();
8077 if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
8078 /*EllipsisLoc*/ SourceLocation(),
8079 /*BuildAndDiagnose*/false, CaptureType,
8080 DeclRefType, nullptr)) {
8081 // We will never be able to capture this variable, and we need
8082 // to be able to in any and all instantiations, so diagnose it.
8083 S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
8084 /*EllipsisLoc*/ SourceLocation(),
8085 /*BuildAndDiagnose*/true, CaptureType,
8086 DeclRefType, nullptr);
8087 }
8088 }
8089 });
8090
8091 // Check if 'this' needs to be captured.
8092 if (CurrentLSI->hasPotentialThisCapture()) {
8093 // If we have a capture-capable lambda for 'this', go ahead and capture
8094 // 'this' in that lambda (and all its enclosing lambdas).
8095 if (const Optional<unsigned> Index =
8096 getStackIndexOfNearestEnclosingCaptureCapableLambda(
8097 S.FunctionScopes, /*0 is 'this'*/ nullptr, S)) {
8098 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
8099 S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation,
8100 /*Explicit*/ false, /*BuildAndDiagnose*/ true,
8101 &FunctionScopeIndexOfCapturableLambda);
8102 }
8103 }
8104
8105 // Reset all the potential captures at the end of each full-expression.
8106 CurrentLSI->clearPotentialCaptures();
8107 }
8108
attemptRecovery(Sema & SemaRef,const TypoCorrectionConsumer & Consumer,const TypoCorrection & TC)8109 static ExprResult attemptRecovery(Sema &SemaRef,
8110 const TypoCorrectionConsumer &Consumer,
8111 const TypoCorrection &TC) {
8112 LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(),
8113 Consumer.getLookupResult().getLookupKind());
8114 const CXXScopeSpec *SS = Consumer.getSS();
8115 CXXScopeSpec NewSS;
8116
8117 // Use an approprate CXXScopeSpec for building the expr.
8118 if (auto *NNS = TC.getCorrectionSpecifier())
8119 NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange());
8120 else if (SS && !TC.WillReplaceSpecifier())
8121 NewSS = *SS;
8122
8123 if (auto *ND = TC.getFoundDecl()) {
8124 R.setLookupName(ND->getDeclName());
8125 R.addDecl(ND);
8126 if (ND->isCXXClassMember()) {
8127 // Figure out the correct naming class to add to the LookupResult.
8128 CXXRecordDecl *Record = nullptr;
8129 if (auto *NNS = TC.getCorrectionSpecifier())
8130 Record = NNS->getAsType()->getAsCXXRecordDecl();
8131 if (!Record)
8132 Record =
8133 dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext());
8134 if (Record)
8135 R.setNamingClass(Record);
8136
8137 // Detect and handle the case where the decl might be an implicit
8138 // member.
8139 bool MightBeImplicitMember;
8140 if (!Consumer.isAddressOfOperand())
8141 MightBeImplicitMember = true;
8142 else if (!NewSS.isEmpty())
8143 MightBeImplicitMember = false;
8144 else if (R.isOverloadedResult())
8145 MightBeImplicitMember = false;
8146 else if (R.isUnresolvableResult())
8147 MightBeImplicitMember = true;
8148 else
8149 MightBeImplicitMember = isa<FieldDecl>(ND) ||
8150 isa<IndirectFieldDecl>(ND) ||
8151 isa<MSPropertyDecl>(ND);
8152
8153 if (MightBeImplicitMember)
8154 return SemaRef.BuildPossibleImplicitMemberExpr(
8155 NewSS, /*TemplateKWLoc*/ SourceLocation(), R,
8156 /*TemplateArgs*/ nullptr, /*S*/ nullptr);
8157 } else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) {
8158 return SemaRef.LookupInObjCMethod(R, Consumer.getScope(),
8159 Ivar->getIdentifier());
8160 }
8161 }
8162
8163 return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false,
8164 /*AcceptInvalidDecl*/ true);
8165 }
8166
8167 namespace {
8168 class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> {
8169 llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs;
8170
8171 public:
FindTypoExprs(llvm::SmallSetVector<TypoExpr *,2> & TypoExprs)8172 explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs)
8173 : TypoExprs(TypoExprs) {}
VisitTypoExpr(TypoExpr * TE)8174 bool VisitTypoExpr(TypoExpr *TE) {
8175 TypoExprs.insert(TE);
8176 return true;
8177 }
8178 };
8179
8180 class TransformTypos : public TreeTransform<TransformTypos> {
8181 typedef TreeTransform<TransformTypos> BaseTransform;
8182
8183 VarDecl *InitDecl; // A decl to avoid as a correction because it is in the
8184 // process of being initialized.
8185 llvm::function_ref<ExprResult(Expr *)> ExprFilter;
8186 llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs;
8187 llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache;
8188 llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution;
8189
8190 /// Emit diagnostics for all of the TypoExprs encountered.
8191 ///
8192 /// If the TypoExprs were successfully corrected, then the diagnostics should
8193 /// suggest the corrections. Otherwise the diagnostics will not suggest
8194 /// anything (having been passed an empty TypoCorrection).
8195 ///
8196 /// If we've failed to correct due to ambiguous corrections, we need to
8197 /// be sure to pass empty corrections and replacements. Otherwise it's
8198 /// possible that the Consumer has a TypoCorrection that failed to ambiguity
8199 /// and we don't want to report those diagnostics.
EmitAllDiagnostics(bool IsAmbiguous)8200 void EmitAllDiagnostics(bool IsAmbiguous) {
8201 for (TypoExpr *TE : TypoExprs) {
8202 auto &State = SemaRef.getTypoExprState(TE);
8203 if (State.DiagHandler) {
8204 TypoCorrection TC = IsAmbiguous
8205 ? TypoCorrection() : State.Consumer->getCurrentCorrection();
8206 ExprResult Replacement = IsAmbiguous ? ExprError() : TransformCache[TE];
8207
8208 // Extract the NamedDecl from the transformed TypoExpr and add it to the
8209 // TypoCorrection, replacing the existing decls. This ensures the right
8210 // NamedDecl is used in diagnostics e.g. in the case where overload
8211 // resolution was used to select one from several possible decls that
8212 // had been stored in the TypoCorrection.
8213 if (auto *ND = getDeclFromExpr(
8214 Replacement.isInvalid() ? nullptr : Replacement.get()))
8215 TC.setCorrectionDecl(ND);
8216
8217 State.DiagHandler(TC);
8218 }
8219 SemaRef.clearDelayedTypo(TE);
8220 }
8221 }
8222
8223 /// Try to advance the typo correction state of the first unfinished TypoExpr.
8224 /// We allow advancement of the correction stream by removing it from the
8225 /// TransformCache which allows `TransformTypoExpr` to advance during the
8226 /// next transformation attempt.
8227 ///
8228 /// Any substitution attempts for the previous TypoExprs (which must have been
8229 /// finished) will need to be retried since it's possible that they will now
8230 /// be invalid given the latest advancement.
8231 ///
8232 /// We need to be sure that we're making progress - it's possible that the
8233 /// tree is so malformed that the transform never makes it to the
8234 /// `TransformTypoExpr`.
8235 ///
8236 /// Returns true if there are any untried correction combinations.
CheckAndAdvanceTypoExprCorrectionStreams()8237 bool CheckAndAdvanceTypoExprCorrectionStreams() {
8238 for (auto TE : TypoExprs) {
8239 auto &State = SemaRef.getTypoExprState(TE);
8240 TransformCache.erase(TE);
8241 if (!State.Consumer->hasMadeAnyCorrectionProgress())
8242 return false;
8243 if (!State.Consumer->finished())
8244 return true;
8245 State.Consumer->resetCorrectionStream();
8246 }
8247 return false;
8248 }
8249
getDeclFromExpr(Expr * E)8250 NamedDecl *getDeclFromExpr(Expr *E) {
8251 if (auto *OE = dyn_cast_or_null<OverloadExpr>(E))
8252 E = OverloadResolution[OE];
8253
8254 if (!E)
8255 return nullptr;
8256 if (auto *DRE = dyn_cast<DeclRefExpr>(E))
8257 return DRE->getFoundDecl();
8258 if (auto *ME = dyn_cast<MemberExpr>(E))
8259 return ME->getFoundDecl();
8260 // FIXME: Add any other expr types that could be be seen by the delayed typo
8261 // correction TreeTransform for which the corresponding TypoCorrection could
8262 // contain multiple decls.
8263 return nullptr;
8264 }
8265
TryTransform(Expr * E)8266 ExprResult TryTransform(Expr *E) {
8267 Sema::SFINAETrap Trap(SemaRef);
8268 ExprResult Res = TransformExpr(E);
8269 if (Trap.hasErrorOccurred() || Res.isInvalid())
8270 return ExprError();
8271
8272 return ExprFilter(Res.get());
8273 }
8274
8275 // Since correcting typos may intoduce new TypoExprs, this function
8276 // checks for new TypoExprs and recurses if it finds any. Note that it will
8277 // only succeed if it is able to correct all typos in the given expression.
CheckForRecursiveTypos(ExprResult Res,bool & IsAmbiguous)8278 ExprResult CheckForRecursiveTypos(ExprResult Res, bool &IsAmbiguous) {
8279 if (Res.isInvalid()) {
8280 return Res;
8281 }
8282 // Check to see if any new TypoExprs were created. If so, we need to recurse
8283 // to check their validity.
8284 Expr *FixedExpr = Res.get();
8285
8286 auto SavedTypoExprs = std::move(TypoExprs);
8287 auto SavedAmbiguousTypoExprs = std::move(AmbiguousTypoExprs);
8288 TypoExprs.clear();
8289 AmbiguousTypoExprs.clear();
8290
8291 FindTypoExprs(TypoExprs).TraverseStmt(FixedExpr);
8292 if (!TypoExprs.empty()) {
8293 // Recurse to handle newly created TypoExprs. If we're not able to
8294 // handle them, discard these TypoExprs.
8295 ExprResult RecurResult =
8296 RecursiveTransformLoop(FixedExpr, IsAmbiguous);
8297 if (RecurResult.isInvalid()) {
8298 Res = ExprError();
8299 // Recursive corrections didn't work, wipe them away and don't add
8300 // them to the TypoExprs set. Remove them from Sema's TypoExpr list
8301 // since we don't want to clear them twice. Note: it's possible the
8302 // TypoExprs were created recursively and thus won't be in our
8303 // Sema's TypoExprs - they were created in our `RecursiveTransformLoop`.
8304 auto &SemaTypoExprs = SemaRef.TypoExprs;
8305 for (auto TE : TypoExprs) {
8306 TransformCache.erase(TE);
8307 SemaRef.clearDelayedTypo(TE);
8308
8309 auto SI = find(SemaTypoExprs, TE);
8310 if (SI != SemaTypoExprs.end()) {
8311 SemaTypoExprs.erase(SI);
8312 }
8313 }
8314 } else {
8315 // TypoExpr is valid: add newly created TypoExprs since we were
8316 // able to correct them.
8317 Res = RecurResult;
8318 SavedTypoExprs.set_union(TypoExprs);
8319 }
8320 }
8321
8322 TypoExprs = std::move(SavedTypoExprs);
8323 AmbiguousTypoExprs = std::move(SavedAmbiguousTypoExprs);
8324
8325 return Res;
8326 }
8327
8328 // Try to transform the given expression, looping through the correction
8329 // candidates with `CheckAndAdvanceTypoExprCorrectionStreams`.
8330 //
8331 // If valid ambiguous typo corrections are seen, `IsAmbiguous` is set to
8332 // true and this method immediately will return an `ExprError`.
RecursiveTransformLoop(Expr * E,bool & IsAmbiguous)8333 ExprResult RecursiveTransformLoop(Expr *E, bool &IsAmbiguous) {
8334 ExprResult Res;
8335 auto SavedTypoExprs = std::move(SemaRef.TypoExprs);
8336 SemaRef.TypoExprs.clear();
8337
8338 while (true) {
8339 Res = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous);
8340
8341 // Recursion encountered an ambiguous correction. This means that our
8342 // correction itself is ambiguous, so stop now.
8343 if (IsAmbiguous)
8344 break;
8345
8346 // If the transform is still valid after checking for any new typos,
8347 // it's good to go.
8348 if (!Res.isInvalid())
8349 break;
8350
8351 // The transform was invalid, see if we have any TypoExprs with untried
8352 // correction candidates.
8353 if (!CheckAndAdvanceTypoExprCorrectionStreams())
8354 break;
8355 }
8356
8357 // If we found a valid result, double check to make sure it's not ambiguous.
8358 if (!IsAmbiguous && !Res.isInvalid() && !AmbiguousTypoExprs.empty()) {
8359 auto SavedTransformCache =
8360 llvm::SmallDenseMap<TypoExpr *, ExprResult, 2>(TransformCache);
8361
8362 // Ensure none of the TypoExprs have multiple typo correction candidates
8363 // with the same edit length that pass all the checks and filters.
8364 while (!AmbiguousTypoExprs.empty()) {
8365 auto TE = AmbiguousTypoExprs.back();
8366
8367 // TryTransform itself can create new Typos, adding them to the TypoExpr map
8368 // and invalidating our TypoExprState, so always fetch it instead of storing.
8369 SemaRef.getTypoExprState(TE).Consumer->saveCurrentPosition();
8370
8371 TypoCorrection TC = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection();
8372 TypoCorrection Next;
8373 do {
8374 // Fetch the next correction by erasing the typo from the cache and calling
8375 // `TryTransform` which will iterate through corrections in
8376 // `TransformTypoExpr`.
8377 TransformCache.erase(TE);
8378 ExprResult AmbigRes = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous);
8379
8380 if (!AmbigRes.isInvalid() || IsAmbiguous) {
8381 SemaRef.getTypoExprState(TE).Consumer->resetCorrectionStream();
8382 SavedTransformCache.erase(TE);
8383 Res = ExprError();
8384 IsAmbiguous = true;
8385 break;
8386 }
8387 } while ((Next = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection()) &&
8388 Next.getEditDistance(false) == TC.getEditDistance(false));
8389
8390 if (IsAmbiguous)
8391 break;
8392
8393 AmbiguousTypoExprs.remove(TE);
8394 SemaRef.getTypoExprState(TE).Consumer->restoreSavedPosition();
8395 TransformCache[TE] = SavedTransformCache[TE];
8396 }
8397 TransformCache = std::move(SavedTransformCache);
8398 }
8399
8400 // Wipe away any newly created TypoExprs that we don't know about. Since we
8401 // clear any invalid TypoExprs in `CheckForRecursiveTypos`, this is only
8402 // possible if a `TypoExpr` is created during a transformation but then
8403 // fails before we can discover it.
8404 auto &SemaTypoExprs = SemaRef.TypoExprs;
8405 for (auto Iterator = SemaTypoExprs.begin(); Iterator != SemaTypoExprs.end();) {
8406 auto TE = *Iterator;
8407 auto FI = find(TypoExprs, TE);
8408 if (FI != TypoExprs.end()) {
8409 Iterator++;
8410 continue;
8411 }
8412 SemaRef.clearDelayedTypo(TE);
8413 Iterator = SemaTypoExprs.erase(Iterator);
8414 }
8415 SemaRef.TypoExprs = std::move(SavedTypoExprs);
8416
8417 return Res;
8418 }
8419
8420 public:
TransformTypos(Sema & SemaRef,VarDecl * InitDecl,llvm::function_ref<ExprResult (Expr *)> Filter)8421 TransformTypos(Sema &SemaRef, VarDecl *InitDecl, llvm::function_ref<ExprResult(Expr *)> Filter)
8422 : BaseTransform(SemaRef), InitDecl(InitDecl), ExprFilter(Filter) {}
8423
RebuildCallExpr(Expr * Callee,SourceLocation LParenLoc,MultiExprArg Args,SourceLocation RParenLoc,Expr * ExecConfig=nullptr)8424 ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc,
8425 MultiExprArg Args,
8426 SourceLocation RParenLoc,
8427 Expr *ExecConfig = nullptr) {
8428 auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args,
8429 RParenLoc, ExecConfig);
8430 if (auto *OE = dyn_cast<OverloadExpr>(Callee)) {
8431 if (Result.isUsable()) {
8432 Expr *ResultCall = Result.get();
8433 if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall))
8434 ResultCall = BE->getSubExpr();
8435 if (auto *CE = dyn_cast<CallExpr>(ResultCall))
8436 OverloadResolution[OE] = CE->getCallee();
8437 }
8438 }
8439 return Result;
8440 }
8441
TransformLambdaExpr(LambdaExpr * E)8442 ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); }
8443
TransformBlockExpr(BlockExpr * E)8444 ExprResult TransformBlockExpr(BlockExpr *E) { return Owned(E); }
8445
Transform(Expr * E)8446 ExprResult Transform(Expr *E) {
8447 bool IsAmbiguous = false;
8448 ExprResult Res = RecursiveTransformLoop(E, IsAmbiguous);
8449
8450 if (!Res.isUsable())
8451 FindTypoExprs(TypoExprs).TraverseStmt(E);
8452
8453 EmitAllDiagnostics(IsAmbiguous);
8454
8455 return Res;
8456 }
8457
TransformTypoExpr(TypoExpr * E)8458 ExprResult TransformTypoExpr(TypoExpr *E) {
8459 // If the TypoExpr hasn't been seen before, record it. Otherwise, return the
8460 // cached transformation result if there is one and the TypoExpr isn't the
8461 // first one that was encountered.
8462 auto &CacheEntry = TransformCache[E];
8463 if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) {
8464 return CacheEntry;
8465 }
8466
8467 auto &State = SemaRef.getTypoExprState(E);
8468 assert(State.Consumer && "Cannot transform a cleared TypoExpr");
8469
8470 // For the first TypoExpr and an uncached TypoExpr, find the next likely
8471 // typo correction and return it.
8472 while (TypoCorrection TC = State.Consumer->getNextCorrection()) {
8473 if (InitDecl && TC.getFoundDecl() == InitDecl)
8474 continue;
8475 // FIXME: If we would typo-correct to an invalid declaration, it's
8476 // probably best to just suppress all errors from this typo correction.
8477 ExprResult NE = State.RecoveryHandler ?
8478 State.RecoveryHandler(SemaRef, E, TC) :
8479 attemptRecovery(SemaRef, *State.Consumer, TC);
8480 if (!NE.isInvalid()) {
8481 // Check whether there may be a second viable correction with the same
8482 // edit distance; if so, remember this TypoExpr may have an ambiguous
8483 // correction so it can be more thoroughly vetted later.
8484 TypoCorrection Next;
8485 if ((Next = State.Consumer->peekNextCorrection()) &&
8486 Next.getEditDistance(false) == TC.getEditDistance(false)) {
8487 AmbiguousTypoExprs.insert(E);
8488 } else {
8489 AmbiguousTypoExprs.remove(E);
8490 }
8491 assert(!NE.isUnset() &&
8492 "Typo was transformed into a valid-but-null ExprResult");
8493 return CacheEntry = NE;
8494 }
8495 }
8496 return CacheEntry = ExprError();
8497 }
8498 };
8499 }
8500
8501 ExprResult
CorrectDelayedTyposInExpr(Expr * E,VarDecl * InitDecl,bool RecoverUncorrectedTypos,llvm::function_ref<ExprResult (Expr *)> Filter)8502 Sema::CorrectDelayedTyposInExpr(Expr *E, VarDecl *InitDecl,
8503 bool RecoverUncorrectedTypos,
8504 llvm::function_ref<ExprResult(Expr *)> Filter) {
8505 // If the current evaluation context indicates there are uncorrected typos
8506 // and the current expression isn't guaranteed to not have typos, try to
8507 // resolve any TypoExpr nodes that might be in the expression.
8508 if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos &&
8509 (E->isTypeDependent() || E->isValueDependent() ||
8510 E->isInstantiationDependent())) {
8511 auto TyposResolved = DelayedTypos.size();
8512 auto Result = TransformTypos(*this, InitDecl, Filter).Transform(E);
8513 TyposResolved -= DelayedTypos.size();
8514 if (Result.isInvalid() || Result.get() != E) {
8515 ExprEvalContexts.back().NumTypos -= TyposResolved;
8516 if (Result.isInvalid() && RecoverUncorrectedTypos) {
8517 struct TyposReplace : TreeTransform<TyposReplace> {
8518 TyposReplace(Sema &SemaRef) : TreeTransform(SemaRef) {}
8519 ExprResult TransformTypoExpr(clang::TypoExpr *E) {
8520 return this->SemaRef.CreateRecoveryExpr(E->getBeginLoc(),
8521 E->getEndLoc(), {});
8522 }
8523 } TT(*this);
8524 return TT.TransformExpr(E);
8525 }
8526 return Result;
8527 }
8528 assert(TyposResolved == 0 && "Corrected typo but got same Expr back?");
8529 }
8530 return E;
8531 }
8532
ActOnFinishFullExpr(Expr * FE,SourceLocation CC,bool DiscardedValue,bool IsConstexpr)8533 ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC,
8534 bool DiscardedValue,
8535 bool IsConstexpr) {
8536 ExprResult FullExpr = FE;
8537
8538 if (!FullExpr.get())
8539 return ExprError();
8540
8541 if (DiagnoseUnexpandedParameterPack(FullExpr.get()))
8542 return ExprError();
8543
8544 if (DiscardedValue) {
8545 // Top-level expressions default to 'id' when we're in a debugger.
8546 if (getLangOpts().DebuggerCastResultToId &&
8547 FullExpr.get()->getType() == Context.UnknownAnyTy) {
8548 FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType());
8549 if (FullExpr.isInvalid())
8550 return ExprError();
8551 }
8552
8553 FullExpr = CheckPlaceholderExpr(FullExpr.get());
8554 if (FullExpr.isInvalid())
8555 return ExprError();
8556
8557 FullExpr = IgnoredValueConversions(FullExpr.get());
8558 if (FullExpr.isInvalid())
8559 return ExprError();
8560
8561 DiagnoseUnusedExprResult(FullExpr.get(), diag::warn_unused_expr);
8562 }
8563
8564 FullExpr = CorrectDelayedTyposInExpr(FullExpr.get(), /*InitDecl=*/nullptr,
8565 /*RecoverUncorrectedTypos=*/true);
8566 if (FullExpr.isInvalid())
8567 return ExprError();
8568
8569 CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr);
8570
8571 // At the end of this full expression (which could be a deeply nested
8572 // lambda), if there is a potential capture within the nested lambda,
8573 // have the outer capture-able lambda try and capture it.
8574 // Consider the following code:
8575 // void f(int, int);
8576 // void f(const int&, double);
8577 // void foo() {
8578 // const int x = 10, y = 20;
8579 // auto L = [=](auto a) {
8580 // auto M = [=](auto b) {
8581 // f(x, b); <-- requires x to be captured by L and M
8582 // f(y, a); <-- requires y to be captured by L, but not all Ms
8583 // };
8584 // };
8585 // }
8586
8587 // FIXME: Also consider what happens for something like this that involves
8588 // the gnu-extension statement-expressions or even lambda-init-captures:
8589 // void f() {
8590 // const int n = 0;
8591 // auto L = [&](auto a) {
8592 // +n + ({ 0; a; });
8593 // };
8594 // }
8595 //
8596 // Here, we see +n, and then the full-expression 0; ends, so we don't
8597 // capture n (and instead remove it from our list of potential captures),
8598 // and then the full-expression +n + ({ 0; }); ends, but it's too late
8599 // for us to see that we need to capture n after all.
8600
8601 LambdaScopeInfo *const CurrentLSI =
8602 getCurLambda(/*IgnoreCapturedRegions=*/true);
8603 // FIXME: PR 17877 showed that getCurLambda() can return a valid pointer
8604 // even if CurContext is not a lambda call operator. Refer to that Bug Report
8605 // for an example of the code that might cause this asynchrony.
8606 // By ensuring we are in the context of a lambda's call operator
8607 // we can fix the bug (we only need to check whether we need to capture
8608 // if we are within a lambda's body); but per the comments in that
8609 // PR, a proper fix would entail :
8610 // "Alternative suggestion:
8611 // - Add to Sema an integer holding the smallest (outermost) scope
8612 // index that we are *lexically* within, and save/restore/set to
8613 // FunctionScopes.size() in InstantiatingTemplate's
8614 // constructor/destructor.
8615 // - Teach the handful of places that iterate over FunctionScopes to
8616 // stop at the outermost enclosing lexical scope."
8617 DeclContext *DC = CurContext;
8618 while (DC && isa<CapturedDecl>(DC))
8619 DC = DC->getParent();
8620 const bool IsInLambdaDeclContext = isLambdaCallOperator(DC);
8621 if (IsInLambdaDeclContext && CurrentLSI &&
8622 CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid())
8623 CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI,
8624 *this);
8625 return MaybeCreateExprWithCleanups(FullExpr);
8626 }
8627
ActOnFinishFullStmt(Stmt * FullStmt)8628 StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) {
8629 if (!FullStmt) return StmtError();
8630
8631 return MaybeCreateStmtWithCleanups(FullStmt);
8632 }
8633
8634 Sema::IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope * S,CXXScopeSpec & SS,const DeclarationNameInfo & TargetNameInfo)8635 Sema::CheckMicrosoftIfExistsSymbol(Scope *S,
8636 CXXScopeSpec &SS,
8637 const DeclarationNameInfo &TargetNameInfo) {
8638 DeclarationName TargetName = TargetNameInfo.getName();
8639 if (!TargetName)
8640 return IER_DoesNotExist;
8641
8642 // If the name itself is dependent, then the result is dependent.
8643 if (TargetName.isDependentName())
8644 return IER_Dependent;
8645
8646 // Do the redeclaration lookup in the current scope.
8647 LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName,
8648 Sema::NotForRedeclaration);
8649 LookupParsedName(R, S, &SS);
8650 R.suppressDiagnostics();
8651
8652 switch (R.getResultKind()) {
8653 case LookupResult::Found:
8654 case LookupResult::FoundOverloaded:
8655 case LookupResult::FoundUnresolvedValue:
8656 case LookupResult::Ambiguous:
8657 return IER_Exists;
8658
8659 case LookupResult::NotFound:
8660 return IER_DoesNotExist;
8661
8662 case LookupResult::NotFoundInCurrentInstantiation:
8663 return IER_Dependent;
8664 }
8665
8666 llvm_unreachable("Invalid LookupResult Kind!");
8667 }
8668
8669 Sema::IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope * S,SourceLocation KeywordLoc,bool IsIfExists,CXXScopeSpec & SS,UnqualifiedId & Name)8670 Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc,
8671 bool IsIfExists, CXXScopeSpec &SS,
8672 UnqualifiedId &Name) {
8673 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
8674
8675 // Check for an unexpanded parameter pack.
8676 auto UPPC = IsIfExists ? UPPC_IfExists : UPPC_IfNotExists;
8677 if (DiagnoseUnexpandedParameterPack(SS, UPPC) ||
8678 DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC))
8679 return IER_Error;
8680
8681 return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo);
8682 }
8683
ActOnSimpleRequirement(Expr * E)8684 concepts::Requirement *Sema::ActOnSimpleRequirement(Expr *E) {
8685 return BuildExprRequirement(E, /*IsSimple=*/true,
8686 /*NoexceptLoc=*/SourceLocation(),
8687 /*ReturnTypeRequirement=*/{});
8688 }
8689
8690 concepts::Requirement *
ActOnTypeRequirement(SourceLocation TypenameKWLoc,CXXScopeSpec & SS,SourceLocation NameLoc,IdentifierInfo * TypeName,TemplateIdAnnotation * TemplateId)8691 Sema::ActOnTypeRequirement(SourceLocation TypenameKWLoc, CXXScopeSpec &SS,
8692 SourceLocation NameLoc, IdentifierInfo *TypeName,
8693 TemplateIdAnnotation *TemplateId) {
8694 assert(((!TypeName && TemplateId) || (TypeName && !TemplateId)) &&
8695 "Exactly one of TypeName and TemplateId must be specified.");
8696 TypeSourceInfo *TSI = nullptr;
8697 if (TypeName) {
8698 QualType T = CheckTypenameType(ETK_Typename, TypenameKWLoc,
8699 SS.getWithLocInContext(Context), *TypeName,
8700 NameLoc, &TSI, /*DeducedTypeContext=*/false);
8701 if (T.isNull())
8702 return nullptr;
8703 } else {
8704 ASTTemplateArgsPtr ArgsPtr(TemplateId->getTemplateArgs(),
8705 TemplateId->NumArgs);
8706 TypeResult T = ActOnTypenameType(CurScope, TypenameKWLoc, SS,
8707 TemplateId->TemplateKWLoc,
8708 TemplateId->Template, TemplateId->Name,
8709 TemplateId->TemplateNameLoc,
8710 TemplateId->LAngleLoc, ArgsPtr,
8711 TemplateId->RAngleLoc);
8712 if (T.isInvalid())
8713 return nullptr;
8714 if (GetTypeFromParser(T.get(), &TSI).isNull())
8715 return nullptr;
8716 }
8717 return BuildTypeRequirement(TSI);
8718 }
8719
8720 concepts::Requirement *
ActOnCompoundRequirement(Expr * E,SourceLocation NoexceptLoc)8721 Sema::ActOnCompoundRequirement(Expr *E, SourceLocation NoexceptLoc) {
8722 return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc,
8723 /*ReturnTypeRequirement=*/{});
8724 }
8725
8726 concepts::Requirement *
ActOnCompoundRequirement(Expr * E,SourceLocation NoexceptLoc,CXXScopeSpec & SS,TemplateIdAnnotation * TypeConstraint,unsigned Depth)8727 Sema::ActOnCompoundRequirement(
8728 Expr *E, SourceLocation NoexceptLoc, CXXScopeSpec &SS,
8729 TemplateIdAnnotation *TypeConstraint, unsigned Depth) {
8730 // C++2a [expr.prim.req.compound] p1.3.3
8731 // [..] the expression is deduced against an invented function template
8732 // F [...] F is a void function template with a single type template
8733 // parameter T declared with the constrained-parameter. Form a new
8734 // cv-qualifier-seq cv by taking the union of const and volatile specifiers
8735 // around the constrained-parameter. F has a single parameter whose
8736 // type-specifier is cv T followed by the abstract-declarator. [...]
8737 //
8738 // The cv part is done in the calling function - we get the concept with
8739 // arguments and the abstract declarator with the correct CV qualification and
8740 // have to synthesize T and the single parameter of F.
8741 auto &II = Context.Idents.get("expr-type");
8742 auto *TParam = TemplateTypeParmDecl::Create(Context, CurContext,
8743 SourceLocation(),
8744 SourceLocation(), Depth,
8745 /*Index=*/0, &II,
8746 /*Typename=*/true,
8747 /*ParameterPack=*/false,
8748 /*HasTypeConstraint=*/true);
8749
8750 if (BuildTypeConstraint(SS, TypeConstraint, TParam,
8751 /*EllpsisLoc=*/SourceLocation(),
8752 /*AllowUnexpandedPack=*/true))
8753 // Just produce a requirement with no type requirements.
8754 return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc, {});
8755
8756 auto *TPL = TemplateParameterList::Create(Context, SourceLocation(),
8757 SourceLocation(),
8758 ArrayRef<NamedDecl *>(TParam),
8759 SourceLocation(),
8760 /*RequiresClause=*/nullptr);
8761 return BuildExprRequirement(
8762 E, /*IsSimple=*/false, NoexceptLoc,
8763 concepts::ExprRequirement::ReturnTypeRequirement(TPL));
8764 }
8765
8766 concepts::ExprRequirement *
BuildExprRequirement(Expr * E,bool IsSimple,SourceLocation NoexceptLoc,concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement)8767 Sema::BuildExprRequirement(
8768 Expr *E, bool IsSimple, SourceLocation NoexceptLoc,
8769 concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) {
8770 auto Status = concepts::ExprRequirement::SS_Satisfied;
8771 ConceptSpecializationExpr *SubstitutedConstraintExpr = nullptr;
8772 if (E->isInstantiationDependent() || ReturnTypeRequirement.isDependent())
8773 Status = concepts::ExprRequirement::SS_Dependent;
8774 else if (NoexceptLoc.isValid() && canThrow(E) == CanThrowResult::CT_Can)
8775 Status = concepts::ExprRequirement::SS_NoexceptNotMet;
8776 else if (ReturnTypeRequirement.isSubstitutionFailure())
8777 Status = concepts::ExprRequirement::SS_TypeRequirementSubstitutionFailure;
8778 else if (ReturnTypeRequirement.isTypeConstraint()) {
8779 // C++2a [expr.prim.req]p1.3.3
8780 // The immediately-declared constraint ([temp]) of decltype((E)) shall
8781 // be satisfied.
8782 TemplateParameterList *TPL =
8783 ReturnTypeRequirement.getTypeConstraintTemplateParameterList();
8784 QualType MatchedType =
8785 Context.getReferenceQualifiedType(E).getCanonicalType();
8786 llvm::SmallVector<TemplateArgument, 1> Args;
8787 Args.push_back(TemplateArgument(MatchedType));
8788 TemplateArgumentList TAL(TemplateArgumentList::OnStack, Args);
8789 MultiLevelTemplateArgumentList MLTAL(TAL);
8790 for (unsigned I = 0; I < TPL->getDepth(); ++I)
8791 MLTAL.addOuterRetainedLevel();
8792 Expr *IDC =
8793 cast<TemplateTypeParmDecl>(TPL->getParam(0))->getTypeConstraint()
8794 ->getImmediatelyDeclaredConstraint();
8795 ExprResult Constraint = SubstExpr(IDC, MLTAL);
8796 assert(!Constraint.isInvalid() &&
8797 "Substitution cannot fail as it is simply putting a type template "
8798 "argument into a concept specialization expression's parameter.");
8799
8800 SubstitutedConstraintExpr =
8801 cast<ConceptSpecializationExpr>(Constraint.get());
8802 if (!SubstitutedConstraintExpr->isSatisfied())
8803 Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied;
8804 }
8805 return new (Context) concepts::ExprRequirement(E, IsSimple, NoexceptLoc,
8806 ReturnTypeRequirement, Status,
8807 SubstitutedConstraintExpr);
8808 }
8809
8810 concepts::ExprRequirement *
BuildExprRequirement(concepts::Requirement::SubstitutionDiagnostic * ExprSubstitutionDiagnostic,bool IsSimple,SourceLocation NoexceptLoc,concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement)8811 Sema::BuildExprRequirement(
8812 concepts::Requirement::SubstitutionDiagnostic *ExprSubstitutionDiagnostic,
8813 bool IsSimple, SourceLocation NoexceptLoc,
8814 concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) {
8815 return new (Context) concepts::ExprRequirement(ExprSubstitutionDiagnostic,
8816 IsSimple, NoexceptLoc,
8817 ReturnTypeRequirement);
8818 }
8819
8820 concepts::TypeRequirement *
BuildTypeRequirement(TypeSourceInfo * Type)8821 Sema::BuildTypeRequirement(TypeSourceInfo *Type) {
8822 return new (Context) concepts::TypeRequirement(Type);
8823 }
8824
8825 concepts::TypeRequirement *
BuildTypeRequirement(concepts::Requirement::SubstitutionDiagnostic * SubstDiag)8826 Sema::BuildTypeRequirement(
8827 concepts::Requirement::SubstitutionDiagnostic *SubstDiag) {
8828 return new (Context) concepts::TypeRequirement(SubstDiag);
8829 }
8830
ActOnNestedRequirement(Expr * Constraint)8831 concepts::Requirement *Sema::ActOnNestedRequirement(Expr *Constraint) {
8832 return BuildNestedRequirement(Constraint);
8833 }
8834
8835 concepts::NestedRequirement *
BuildNestedRequirement(Expr * Constraint)8836 Sema::BuildNestedRequirement(Expr *Constraint) {
8837 ConstraintSatisfaction Satisfaction;
8838 if (!Constraint->isInstantiationDependent() &&
8839 CheckConstraintSatisfaction(nullptr, {Constraint}, /*TemplateArgs=*/{},
8840 Constraint->getSourceRange(), Satisfaction))
8841 return nullptr;
8842 return new (Context) concepts::NestedRequirement(Context, Constraint,
8843 Satisfaction);
8844 }
8845
8846 concepts::NestedRequirement *
BuildNestedRequirement(concepts::Requirement::SubstitutionDiagnostic * SubstDiag)8847 Sema::BuildNestedRequirement(
8848 concepts::Requirement::SubstitutionDiagnostic *SubstDiag) {
8849 return new (Context) concepts::NestedRequirement(SubstDiag);
8850 }
8851
8852 RequiresExprBodyDecl *
ActOnStartRequiresExpr(SourceLocation RequiresKWLoc,ArrayRef<ParmVarDecl * > LocalParameters,Scope * BodyScope)8853 Sema::ActOnStartRequiresExpr(SourceLocation RequiresKWLoc,
8854 ArrayRef<ParmVarDecl *> LocalParameters,
8855 Scope *BodyScope) {
8856 assert(BodyScope);
8857
8858 RequiresExprBodyDecl *Body = RequiresExprBodyDecl::Create(Context, CurContext,
8859 RequiresKWLoc);
8860
8861 PushDeclContext(BodyScope, Body);
8862
8863 for (ParmVarDecl *Param : LocalParameters) {
8864 if (Param->hasDefaultArg())
8865 // C++2a [expr.prim.req] p4
8866 // [...] A local parameter of a requires-expression shall not have a
8867 // default argument. [...]
8868 Diag(Param->getDefaultArgRange().getBegin(),
8869 diag::err_requires_expr_local_parameter_default_argument);
8870 // Ignore default argument and move on
8871
8872 Param->setDeclContext(Body);
8873 // If this has an identifier, add it to the scope stack.
8874 if (Param->getIdentifier()) {
8875 CheckShadow(BodyScope, Param);
8876 PushOnScopeChains(Param, BodyScope);
8877 }
8878 }
8879 return Body;
8880 }
8881
ActOnFinishRequiresExpr()8882 void Sema::ActOnFinishRequiresExpr() {
8883 assert(CurContext && "DeclContext imbalance!");
8884 CurContext = CurContext->getLexicalParent();
8885 assert(CurContext && "Popped translation unit!");
8886 }
8887
8888 ExprResult
ActOnRequiresExpr(SourceLocation RequiresKWLoc,RequiresExprBodyDecl * Body,ArrayRef<ParmVarDecl * > LocalParameters,ArrayRef<concepts::Requirement * > Requirements,SourceLocation ClosingBraceLoc)8889 Sema::ActOnRequiresExpr(SourceLocation RequiresKWLoc,
8890 RequiresExprBodyDecl *Body,
8891 ArrayRef<ParmVarDecl *> LocalParameters,
8892 ArrayRef<concepts::Requirement *> Requirements,
8893 SourceLocation ClosingBraceLoc) {
8894 auto *RE = RequiresExpr::Create(Context, RequiresKWLoc, Body, LocalParameters,
8895 Requirements, ClosingBraceLoc);
8896 if (DiagnoseUnexpandedParameterPackInRequiresExpr(RE))
8897 return ExprError();
8898 return RE;
8899 }
8900