1 //===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief Implements semantic analysis for C++ expressions.
12 ///
13 //===----------------------------------------------------------------------===//
14
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/EvaluatedExprVisitor.h"
24 #include "clang/AST/ExprCXX.h"
25 #include "clang/AST/ExprObjC.h"
26 #include "clang/AST/RecursiveASTVisitor.h"
27 #include "clang/AST/TypeLoc.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 /// \brief 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
getDestructorName(SourceLocation TildeLoc,IdentifierInfo & II,SourceLocation NameLoc,Scope * S,CXXScopeSpec & SS,ParsedType ObjectTypePtr,bool EnteringContext)83 ParsedType Sema::getDestructorName(SourceLocation TildeLoc,
84 IdentifierInfo &II,
85 SourceLocation NameLoc,
86 Scope *S, CXXScopeSpec &SS,
87 ParsedType ObjectTypePtr,
88 bool EnteringContext) {
89 // Determine where to perform name lookup.
90
91 // FIXME: This area of the standard is very messy, and the current
92 // wording is rather unclear about which scopes we search for the
93 // destructor name; see core issues 399 and 555. Issue 399 in
94 // particular shows where the current description of destructor name
95 // lookup is completely out of line with existing practice, e.g.,
96 // this appears to be ill-formed:
97 //
98 // namespace N {
99 // template <typename T> struct S {
100 // ~S();
101 // };
102 // }
103 //
104 // void f(N::S<int>* s) {
105 // s->N::S<int>::~S();
106 // }
107 //
108 // See also PR6358 and PR6359.
109 // For this reason, we're currently only doing the C++03 version of this
110 // code; the C++0x version has to wait until we get a proper spec.
111 QualType SearchType;
112 DeclContext *LookupCtx = nullptr;
113 bool isDependent = false;
114 bool LookInScope = false;
115
116 // If we have an object type, it's because we are in a
117 // pseudo-destructor-expression or a member access expression, and
118 // we know what type we're looking for.
119 if (ObjectTypePtr)
120 SearchType = GetTypeFromParser(ObjectTypePtr);
121
122 if (SS.isSet()) {
123 NestedNameSpecifier *NNS = SS.getScopeRep();
124
125 bool AlreadySearched = false;
126 bool LookAtPrefix = true;
127 // C++11 [basic.lookup.qual]p6:
128 // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier,
129 // the type-names are looked up as types in the scope designated by the
130 // nested-name-specifier. Similarly, in a qualified-id of the form:
131 //
132 // nested-name-specifier[opt] class-name :: ~ class-name
133 //
134 // the second class-name is looked up in the same scope as the first.
135 //
136 // Here, we determine whether the code below is permitted to look at the
137 // prefix of the nested-name-specifier.
138 DeclContext *DC = computeDeclContext(SS, EnteringContext);
139 if (DC && DC->isFileContext()) {
140 AlreadySearched = true;
141 LookupCtx = DC;
142 isDependent = false;
143 } else if (DC && isa<CXXRecordDecl>(DC)) {
144 LookAtPrefix = false;
145 LookInScope = true;
146 }
147
148 // The second case from the C++03 rules quoted further above.
149 NestedNameSpecifier *Prefix = nullptr;
150 if (AlreadySearched) {
151 // Nothing left to do.
152 } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) {
153 CXXScopeSpec PrefixSS;
154 PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
155 LookupCtx = computeDeclContext(PrefixSS, EnteringContext);
156 isDependent = isDependentScopeSpecifier(PrefixSS);
157 } else if (ObjectTypePtr) {
158 LookupCtx = computeDeclContext(SearchType);
159 isDependent = SearchType->isDependentType();
160 } else {
161 LookupCtx = computeDeclContext(SS, EnteringContext);
162 isDependent = LookupCtx && LookupCtx->isDependentContext();
163 }
164 } else if (ObjectTypePtr) {
165 // C++ [basic.lookup.classref]p3:
166 // If the unqualified-id is ~type-name, the type-name is looked up
167 // in the context of the entire postfix-expression. If the type T
168 // of the object expression is of a class type C, the type-name is
169 // also looked up in the scope of class C. At least one of the
170 // lookups shall find a name that refers to (possibly
171 // cv-qualified) T.
172 LookupCtx = computeDeclContext(SearchType);
173 isDependent = SearchType->isDependentType();
174 assert((isDependent || !SearchType->isIncompleteType()) &&
175 "Caller should have completed object type");
176
177 LookInScope = true;
178 } else {
179 // Perform lookup into the current scope (only).
180 LookInScope = true;
181 }
182
183 TypeDecl *NonMatchingTypeDecl = nullptr;
184 LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName);
185 for (unsigned Step = 0; Step != 2; ++Step) {
186 // Look for the name first in the computed lookup context (if we
187 // have one) and, if that fails to find a match, in the scope (if
188 // we're allowed to look there).
189 Found.clear();
190 if (Step == 0 && LookupCtx)
191 LookupQualifiedName(Found, LookupCtx);
192 else if (Step == 1 && LookInScope && S)
193 LookupName(Found, S);
194 else
195 continue;
196
197 // FIXME: Should we be suppressing ambiguities here?
198 if (Found.isAmbiguous())
199 return ParsedType();
200
201 if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
202 QualType T = Context.getTypeDeclType(Type);
203 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
204
205 if (SearchType.isNull() || SearchType->isDependentType() ||
206 Context.hasSameUnqualifiedType(T, SearchType)) {
207 // We found our type!
208
209 return CreateParsedType(T,
210 Context.getTrivialTypeSourceInfo(T, NameLoc));
211 }
212
213 if (!SearchType.isNull())
214 NonMatchingTypeDecl = Type;
215 }
216
217 // If the name that we found is a class template name, and it is
218 // the same name as the template name in the last part of the
219 // nested-name-specifier (if present) or the object type, then
220 // this is the destructor for that class.
221 // FIXME: This is a workaround until we get real drafting for core
222 // issue 399, for which there isn't even an obvious direction.
223 if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) {
224 QualType MemberOfType;
225 if (SS.isSet()) {
226 if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) {
227 // Figure out the type of the context, if it has one.
228 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx))
229 MemberOfType = Context.getTypeDeclType(Record);
230 }
231 }
232 if (MemberOfType.isNull())
233 MemberOfType = SearchType;
234
235 if (MemberOfType.isNull())
236 continue;
237
238 // We're referring into a class template specialization. If the
239 // class template we found is the same as the template being
240 // specialized, we found what we are looking for.
241 if (const RecordType *Record = MemberOfType->getAs<RecordType>()) {
242 if (ClassTemplateSpecializationDecl *Spec
243 = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) {
244 if (Spec->getSpecializedTemplate()->getCanonicalDecl() ==
245 Template->getCanonicalDecl())
246 return CreateParsedType(
247 MemberOfType,
248 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
249 }
250
251 continue;
252 }
253
254 // We're referring to an unresolved class template
255 // specialization. Determine whether we class template we found
256 // is the same as the template being specialized or, if we don't
257 // know which template is being specialized, that it at least
258 // has the same name.
259 if (const TemplateSpecializationType *SpecType
260 = MemberOfType->getAs<TemplateSpecializationType>()) {
261 TemplateName SpecName = SpecType->getTemplateName();
262
263 // The class template we found is the same template being
264 // specialized.
265 if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) {
266 if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl())
267 return CreateParsedType(
268 MemberOfType,
269 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
270
271 continue;
272 }
273
274 // The class template we found has the same name as the
275 // (dependent) template name being specialized.
276 if (DependentTemplateName *DepTemplate
277 = SpecName.getAsDependentTemplateName()) {
278 if (DepTemplate->isIdentifier() &&
279 DepTemplate->getIdentifier() == Template->getIdentifier())
280 return CreateParsedType(
281 MemberOfType,
282 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
283
284 continue;
285 }
286 }
287 }
288 }
289
290 if (isDependent) {
291 // We didn't find our type, but that's okay: it's dependent
292 // anyway.
293
294 // FIXME: What if we have no nested-name-specifier?
295 QualType T = CheckTypenameType(ETK_None, SourceLocation(),
296 SS.getWithLocInContext(Context),
297 II, NameLoc);
298 return ParsedType::make(T);
299 }
300
301 if (NonMatchingTypeDecl) {
302 QualType T = Context.getTypeDeclType(NonMatchingTypeDecl);
303 Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
304 << T << SearchType;
305 Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here)
306 << T;
307 } else if (ObjectTypePtr)
308 Diag(NameLoc, diag::err_ident_in_dtor_not_a_type)
309 << &II;
310 else {
311 SemaDiagnosticBuilder DtorDiag = Diag(NameLoc,
312 diag::err_destructor_class_name);
313 if (S) {
314 const DeclContext *Ctx = S->getEntity();
315 if (const CXXRecordDecl *Class = dyn_cast_or_null<CXXRecordDecl>(Ctx))
316 DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc),
317 Class->getNameAsString());
318 }
319 }
320
321 return ParsedType();
322 }
323
getDestructorType(const DeclSpec & DS,ParsedType ObjectType)324 ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) {
325 if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType)
326 return ParsedType();
327 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype
328 && "only get destructor types from declspecs");
329 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
330 QualType SearchType = GetTypeFromParser(ObjectType);
331 if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) {
332 return ParsedType::make(T);
333 }
334
335 Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
336 << T << SearchType;
337 return ParsedType();
338 }
339
checkLiteralOperatorId(const CXXScopeSpec & SS,const UnqualifiedId & Name)340 bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS,
341 const UnqualifiedId &Name) {
342 assert(Name.getKind() == UnqualifiedId::IK_LiteralOperatorId);
343
344 if (!SS.isValid())
345 return false;
346
347 switch (SS.getScopeRep()->getKind()) {
348 case NestedNameSpecifier::Identifier:
349 case NestedNameSpecifier::TypeSpec:
350 case NestedNameSpecifier::TypeSpecWithTemplate:
351 // Per C++11 [over.literal]p2, literal operators can only be declared at
352 // namespace scope. Therefore, this unqualified-id cannot name anything.
353 // Reject it early, because we have no AST representation for this in the
354 // case where the scope is dependent.
355 Diag(Name.getLocStart(), diag::err_literal_operator_id_outside_namespace)
356 << SS.getScopeRep();
357 return true;
358
359 case NestedNameSpecifier::Global:
360 case NestedNameSpecifier::Super:
361 case NestedNameSpecifier::Namespace:
362 case NestedNameSpecifier::NamespaceAlias:
363 return false;
364 }
365
366 llvm_unreachable("unknown nested name specifier kind");
367 }
368
369 /// \brief Build a C++ typeid expression with a type operand.
BuildCXXTypeId(QualType TypeInfoType,SourceLocation TypeidLoc,TypeSourceInfo * Operand,SourceLocation RParenLoc)370 ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
371 SourceLocation TypeidLoc,
372 TypeSourceInfo *Operand,
373 SourceLocation RParenLoc) {
374 // C++ [expr.typeid]p4:
375 // The top-level cv-qualifiers of the lvalue expression or the type-id
376 // that is the operand of typeid are always ignored.
377 // If the type of the type-id is a class type or a reference to a class
378 // type, the class shall be completely-defined.
379 Qualifiers Quals;
380 QualType T
381 = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
382 Quals);
383 if (T->getAs<RecordType>() &&
384 RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
385 return ExprError();
386
387 if (T->isVariablyModifiedType())
388 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);
389
390 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
391 SourceRange(TypeidLoc, RParenLoc));
392 }
393
394 /// \brief Build a C++ typeid expression with an expression operand.
BuildCXXTypeId(QualType TypeInfoType,SourceLocation TypeidLoc,Expr * E,SourceLocation RParenLoc)395 ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
396 SourceLocation TypeidLoc,
397 Expr *E,
398 SourceLocation RParenLoc) {
399 bool WasEvaluated = false;
400 if (E && !E->isTypeDependent()) {
401 if (E->getType()->isPlaceholderType()) {
402 ExprResult result = CheckPlaceholderExpr(E);
403 if (result.isInvalid()) return ExprError();
404 E = result.get();
405 }
406
407 QualType T = E->getType();
408 if (const RecordType *RecordT = T->getAs<RecordType>()) {
409 CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
410 // C++ [expr.typeid]p3:
411 // [...] If the type of the expression is a class type, the class
412 // shall be completely-defined.
413 if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
414 return ExprError();
415
416 // C++ [expr.typeid]p3:
417 // When typeid is applied to an expression other than an glvalue of a
418 // polymorphic class type [...] [the] expression is an unevaluated
419 // operand. [...]
420 if (RecordD->isPolymorphic() && E->isGLValue()) {
421 // The subexpression is potentially evaluated; switch the context
422 // and recheck the subexpression.
423 ExprResult Result = TransformToPotentiallyEvaluated(E);
424 if (Result.isInvalid()) return ExprError();
425 E = Result.get();
426
427 // We require a vtable to query the type at run time.
428 MarkVTableUsed(TypeidLoc, RecordD);
429 WasEvaluated = true;
430 }
431 }
432
433 // C++ [expr.typeid]p4:
434 // [...] If the type of the type-id is a reference to a possibly
435 // cv-qualified type, the result of the typeid expression refers to a
436 // std::type_info object representing the cv-unqualified referenced
437 // type.
438 Qualifiers Quals;
439 QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
440 if (!Context.hasSameType(T, UnqualT)) {
441 T = UnqualT;
442 E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
443 }
444 }
445
446 if (E->getType()->isVariablyModifiedType())
447 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
448 << E->getType());
449 else if (ActiveTemplateInstantiations.empty() &&
450 E->HasSideEffects(Context, WasEvaluated)) {
451 // The expression operand for typeid is in an unevaluated expression
452 // context, so side effects could result in unintended consequences.
453 Diag(E->getExprLoc(), WasEvaluated
454 ? diag::warn_side_effects_typeid
455 : diag::warn_side_effects_unevaluated_context);
456 }
457
458 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
459 SourceRange(TypeidLoc, RParenLoc));
460 }
461
462 /// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
463 ExprResult
ActOnCXXTypeid(SourceLocation OpLoc,SourceLocation LParenLoc,bool isType,void * TyOrExpr,SourceLocation RParenLoc)464 Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
465 bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
466 // Find the std::type_info type.
467 if (!getStdNamespace())
468 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
469
470 if (!CXXTypeInfoDecl) {
471 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
472 LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
473 LookupQualifiedName(R, getStdNamespace());
474 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
475 // Microsoft's typeinfo doesn't have type_info in std but in the global
476 // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
477 if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
478 LookupQualifiedName(R, Context.getTranslationUnitDecl());
479 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
480 }
481 if (!CXXTypeInfoDecl)
482 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
483 }
484
485 if (!getLangOpts().RTTI) {
486 return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
487 }
488
489 QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);
490
491 if (isType) {
492 // The operand is a type; handle it as such.
493 TypeSourceInfo *TInfo = nullptr;
494 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
495 &TInfo);
496 if (T.isNull())
497 return ExprError();
498
499 if (!TInfo)
500 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
501
502 return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
503 }
504
505 // The operand is an expression.
506 return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
507 }
508
509 /// \brief Build a Microsoft __uuidof expression with a type operand.
BuildCXXUuidof(QualType TypeInfoType,SourceLocation TypeidLoc,TypeSourceInfo * Operand,SourceLocation RParenLoc)510 ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType,
511 SourceLocation TypeidLoc,
512 TypeSourceInfo *Operand,
513 SourceLocation RParenLoc) {
514 if (!Operand->getType()->isDependentType()) {
515 bool HasMultipleGUIDs = false;
516 if (!CXXUuidofExpr::GetUuidAttrOfType(Operand->getType(),
517 &HasMultipleGUIDs)) {
518 if (HasMultipleGUIDs)
519 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
520 else
521 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
522 }
523 }
524
525 return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand,
526 SourceRange(TypeidLoc, RParenLoc));
527 }
528
529 /// \brief Build a Microsoft __uuidof expression with an expression operand.
BuildCXXUuidof(QualType TypeInfoType,SourceLocation TypeidLoc,Expr * E,SourceLocation RParenLoc)530 ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType,
531 SourceLocation TypeidLoc,
532 Expr *E,
533 SourceLocation RParenLoc) {
534 if (!E->getType()->isDependentType()) {
535 bool HasMultipleGUIDs = false;
536 if (!CXXUuidofExpr::GetUuidAttrOfType(E->getType(), &HasMultipleGUIDs) &&
537 !E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
538 if (HasMultipleGUIDs)
539 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
540 else
541 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
542 }
543 }
544
545 return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E,
546 SourceRange(TypeidLoc, RParenLoc));
547 }
548
549 /// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
550 ExprResult
ActOnCXXUuidof(SourceLocation OpLoc,SourceLocation LParenLoc,bool isType,void * TyOrExpr,SourceLocation RParenLoc)551 Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc,
552 bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
553 // If MSVCGuidDecl has not been cached, do the lookup.
554 if (!MSVCGuidDecl) {
555 IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID");
556 LookupResult R(*this, GuidII, SourceLocation(), LookupTagName);
557 LookupQualifiedName(R, Context.getTranslationUnitDecl());
558 MSVCGuidDecl = R.getAsSingle<RecordDecl>();
559 if (!MSVCGuidDecl)
560 return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof));
561 }
562
563 QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl);
564
565 if (isType) {
566 // The operand is a type; handle it as such.
567 TypeSourceInfo *TInfo = nullptr;
568 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
569 &TInfo);
570 if (T.isNull())
571 return ExprError();
572
573 if (!TInfo)
574 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
575
576 return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
577 }
578
579 // The operand is an expression.
580 return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
581 }
582
583 /// ActOnCXXBoolLiteral - Parse {true,false} literals.
584 ExprResult
ActOnCXXBoolLiteral(SourceLocation OpLoc,tok::TokenKind Kind)585 Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
586 assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
587 "Unknown C++ Boolean value!");
588 return new (Context)
589 CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
590 }
591
592 /// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
593 ExprResult
ActOnCXXNullPtrLiteral(SourceLocation Loc)594 Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
595 return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
596 }
597
598 /// ActOnCXXThrow - Parse throw expressions.
599 ExprResult
ActOnCXXThrow(Scope * S,SourceLocation OpLoc,Expr * Ex)600 Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) {
601 bool IsThrownVarInScope = false;
602 if (Ex) {
603 // C++0x [class.copymove]p31:
604 // When certain criteria are met, an implementation is allowed to omit the
605 // copy/move construction of a class object [...]
606 //
607 // - in a throw-expression, when the operand is the name of a
608 // non-volatile automatic object (other than a function or catch-
609 // clause parameter) whose scope does not extend beyond the end of the
610 // innermost enclosing try-block (if there is one), the copy/move
611 // operation from the operand to the exception object (15.1) can be
612 // omitted by constructing the automatic object directly into the
613 // exception object
614 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
615 if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
616 if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
617 for( ; S; S = S->getParent()) {
618 if (S->isDeclScope(Var)) {
619 IsThrownVarInScope = true;
620 break;
621 }
622
623 if (S->getFlags() &
624 (Scope::FnScope | Scope::ClassScope | Scope::BlockScope |
625 Scope::FunctionPrototypeScope | Scope::ObjCMethodScope |
626 Scope::TryScope))
627 break;
628 }
629 }
630 }
631 }
632
633 return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
634 }
635
BuildCXXThrow(SourceLocation OpLoc,Expr * Ex,bool IsThrownVarInScope)636 ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
637 bool IsThrownVarInScope) {
638 // Don't report an error if 'throw' is used in system headers.
639 if (!getLangOpts().CXXExceptions &&
640 !getSourceManager().isInSystemHeader(OpLoc))
641 Diag(OpLoc, diag::err_exceptions_disabled) << "throw";
642
643 if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
644 Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";
645
646 if (Ex && !Ex->isTypeDependent()) {
647 ExprResult ExRes = CheckCXXThrowOperand(OpLoc, Ex, IsThrownVarInScope);
648 if (ExRes.isInvalid())
649 return ExprError();
650 Ex = ExRes.get();
651 }
652
653 return new (Context)
654 CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
655 }
656
657 /// CheckCXXThrowOperand - Validate the operand of a throw.
CheckCXXThrowOperand(SourceLocation ThrowLoc,Expr * E,bool IsThrownVarInScope)658 ExprResult Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E,
659 bool IsThrownVarInScope) {
660 // C++ [except.throw]p3:
661 // A throw-expression initializes a temporary object, called the exception
662 // object, the type of which is determined by removing any top-level
663 // cv-qualifiers from the static type of the operand of throw and adjusting
664 // the type from "array of T" or "function returning T" to "pointer to T"
665 // or "pointer to function returning T", [...]
666 if (E->getType().hasQualifiers())
667 E = ImpCastExprToType(E, E->getType().getUnqualifiedType(), CK_NoOp,
668 E->getValueKind()).get();
669
670 ExprResult Res = DefaultFunctionArrayConversion(E);
671 if (Res.isInvalid())
672 return ExprError();
673 E = Res.get();
674
675 // If the type of the exception would be an incomplete type or a pointer
676 // to an incomplete type other than (cv) void the program is ill-formed.
677 QualType Ty = E->getType();
678 bool isPointer = false;
679 if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
680 Ty = Ptr->getPointeeType();
681 isPointer = true;
682 }
683 if (!isPointer || !Ty->isVoidType()) {
684 if (RequireCompleteType(ThrowLoc, Ty,
685 isPointer? diag::err_throw_incomplete_ptr
686 : diag::err_throw_incomplete,
687 E->getSourceRange()))
688 return ExprError();
689
690 if (RequireNonAbstractType(ThrowLoc, E->getType(),
691 diag::err_throw_abstract_type, E))
692 return ExprError();
693 }
694
695 // Initialize the exception result. This implicitly weeds out
696 // abstract types or types with inaccessible copy constructors.
697
698 // C++0x [class.copymove]p31:
699 // When certain criteria are met, an implementation is allowed to omit the
700 // copy/move construction of a class object [...]
701 //
702 // - in a throw-expression, when the operand is the name of a
703 // non-volatile automatic object (other than a function or catch-clause
704 // parameter) whose scope does not extend beyond the end of the
705 // innermost enclosing try-block (if there is one), the copy/move
706 // operation from the operand to the exception object (15.1) can be
707 // omitted by constructing the automatic object directly into the
708 // exception object
709 const VarDecl *NRVOVariable = nullptr;
710 if (IsThrownVarInScope)
711 NRVOVariable = getCopyElisionCandidate(QualType(), E, false);
712
713 InitializedEntity Entity =
714 InitializedEntity::InitializeException(ThrowLoc, E->getType(),
715 /*NRVO=*/NRVOVariable != nullptr);
716 Res = PerformMoveOrCopyInitialization(Entity, NRVOVariable,
717 QualType(), E,
718 IsThrownVarInScope);
719 if (Res.isInvalid())
720 return ExprError();
721 E = Res.get();
722
723 // If the exception has class type, we need additional handling.
724 const RecordType *RecordTy = Ty->getAs<RecordType>();
725 if (!RecordTy)
726 return E;
727 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
728
729 // If we are throwing a polymorphic class type or pointer thereof,
730 // exception handling will make use of the vtable.
731 MarkVTableUsed(ThrowLoc, RD);
732
733 // If a pointer is thrown, the referenced object will not be destroyed.
734 if (isPointer)
735 return E;
736
737 // If the class has a destructor, we must be able to call it.
738 if (RD->hasIrrelevantDestructor())
739 return E;
740
741 CXXDestructorDecl *Destructor = LookupDestructor(RD);
742 if (!Destructor)
743 return E;
744
745 MarkFunctionReferenced(E->getExprLoc(), Destructor);
746 CheckDestructorAccess(E->getExprLoc(), Destructor,
747 PDiag(diag::err_access_dtor_exception) << Ty);
748 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
749 return ExprError();
750 return E;
751 }
752
getCurrentThisType()753 QualType Sema::getCurrentThisType() {
754 DeclContext *DC = getFunctionLevelDeclContext();
755 QualType ThisTy = CXXThisTypeOverride;
756 if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
757 if (method && method->isInstance())
758 ThisTy = method->getThisType(Context);
759 }
760 if (ThisTy.isNull()) {
761 if (isGenericLambdaCallOperatorSpecialization(CurContext) &&
762 CurContext->getParent()->getParent()->isRecord()) {
763 // This is a generic lambda call operator that is being instantiated
764 // within a default initializer - so use the enclosing class as 'this'.
765 // There is no enclosing member function to retrieve the 'this' pointer
766 // from.
767 QualType ClassTy = Context.getTypeDeclType(
768 cast<CXXRecordDecl>(CurContext->getParent()->getParent()));
769 // There are no cv-qualifiers for 'this' within default initializers,
770 // per [expr.prim.general]p4.
771 return Context.getPointerType(ClassTy);
772 }
773 }
774 return ThisTy;
775 }
776
CXXThisScopeRAII(Sema & S,Decl * ContextDecl,unsigned CXXThisTypeQuals,bool Enabled)777 Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S,
778 Decl *ContextDecl,
779 unsigned CXXThisTypeQuals,
780 bool Enabled)
781 : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
782 {
783 if (!Enabled || !ContextDecl)
784 return;
785
786 CXXRecordDecl *Record = nullptr;
787 if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
788 Record = Template->getTemplatedDecl();
789 else
790 Record = cast<CXXRecordDecl>(ContextDecl);
791
792 S.CXXThisTypeOverride
793 = S.Context.getPointerType(
794 S.Context.getRecordType(Record).withCVRQualifiers(CXXThisTypeQuals));
795
796 this->Enabled = true;
797 }
798
799
~CXXThisScopeRAII()800 Sema::CXXThisScopeRAII::~CXXThisScopeRAII() {
801 if (Enabled) {
802 S.CXXThisTypeOverride = OldCXXThisTypeOverride;
803 }
804 }
805
captureThis(ASTContext & Context,RecordDecl * RD,QualType ThisTy,SourceLocation Loc)806 static Expr *captureThis(ASTContext &Context, RecordDecl *RD,
807 QualType ThisTy, SourceLocation Loc) {
808 FieldDecl *Field
809 = FieldDecl::Create(Context, RD, Loc, Loc, nullptr, ThisTy,
810 Context.getTrivialTypeSourceInfo(ThisTy, Loc),
811 nullptr, false, ICIS_NoInit);
812 Field->setImplicit(true);
813 Field->setAccess(AS_private);
814 RD->addDecl(Field);
815 return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit*/true);
816 }
817
CheckCXXThisCapture(SourceLocation Loc,bool Explicit,bool BuildAndDiagnose,const unsigned * const FunctionScopeIndexToStopAt)818 bool Sema::CheckCXXThisCapture(SourceLocation Loc, bool Explicit,
819 bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt) {
820 // We don't need to capture this in an unevaluated context.
821 if (isUnevaluatedContext() && !Explicit)
822 return true;
823
824 const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ?
825 *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1;
826 // Otherwise, check that we can capture 'this'.
827 unsigned NumClosures = 0;
828 for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) {
829 if (CapturingScopeInfo *CSI =
830 dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
831 if (CSI->CXXThisCaptureIndex != 0) {
832 // 'this' is already being captured; there isn't anything more to do.
833 break;
834 }
835 LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
836 if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) {
837 // This context can't implicitly capture 'this'; fail out.
838 if (BuildAndDiagnose)
839 Diag(Loc, diag::err_this_capture) << Explicit;
840 return true;
841 }
842 if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
843 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||
844 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||
845 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||
846 Explicit) {
847 // This closure can capture 'this'; continue looking upwards.
848 NumClosures++;
849 Explicit = false;
850 continue;
851 }
852 // This context can't implicitly capture 'this'; fail out.
853 if (BuildAndDiagnose)
854 Diag(Loc, diag::err_this_capture) << Explicit;
855 return true;
856 }
857 break;
858 }
859 if (!BuildAndDiagnose) return false;
860 // Mark that we're implicitly capturing 'this' in all the scopes we skipped.
861 // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated
862 // contexts.
863 for (unsigned idx = MaxFunctionScopesIndex; NumClosures;
864 --idx, --NumClosures) {
865 CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
866 Expr *ThisExpr = nullptr;
867 QualType ThisTy = getCurrentThisType();
868 if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI))
869 // For lambda expressions, build a field and an initializing expression.
870 ThisExpr = captureThis(Context, LSI->Lambda, ThisTy, Loc);
871 else if (CapturedRegionScopeInfo *RSI
872 = dyn_cast<CapturedRegionScopeInfo>(FunctionScopes[idx]))
873 ThisExpr = captureThis(Context, RSI->TheRecordDecl, ThisTy, Loc);
874
875 bool isNested = NumClosures > 1;
876 CSI->addThisCapture(isNested, Loc, ThisTy, ThisExpr);
877 }
878 return false;
879 }
880
ActOnCXXThis(SourceLocation Loc)881 ExprResult Sema::ActOnCXXThis(SourceLocation Loc) {
882 /// C++ 9.3.2: In the body of a non-static member function, the keyword this
883 /// is a non-lvalue expression whose value is the address of the object for
884 /// which the function is called.
885
886 QualType ThisTy = getCurrentThisType();
887 if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use);
888
889 CheckCXXThisCapture(Loc);
890 return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false);
891 }
892
isThisOutsideMemberFunctionBody(QualType BaseType)893 bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) {
894 // If we're outside the body of a member function, then we'll have a specified
895 // type for 'this'.
896 if (CXXThisTypeOverride.isNull())
897 return false;
898
899 // Determine whether we're looking into a class that's currently being
900 // defined.
901 CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl();
902 return Class && Class->isBeingDefined();
903 }
904
905 ExprResult
ActOnCXXTypeConstructExpr(ParsedType TypeRep,SourceLocation LParenLoc,MultiExprArg exprs,SourceLocation RParenLoc)906 Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep,
907 SourceLocation LParenLoc,
908 MultiExprArg exprs,
909 SourceLocation RParenLoc) {
910 if (!TypeRep)
911 return ExprError();
912
913 TypeSourceInfo *TInfo;
914 QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
915 if (!TInfo)
916 TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation());
917
918 return BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc);
919 }
920
921 /// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
922 /// Can be interpreted either as function-style casting ("int(x)")
923 /// or class type construction ("ClassType(x,y,z)")
924 /// or creation of a value-initialized type ("int()").
925 ExprResult
BuildCXXTypeConstructExpr(TypeSourceInfo * TInfo,SourceLocation LParenLoc,MultiExprArg Exprs,SourceLocation RParenLoc)926 Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo,
927 SourceLocation LParenLoc,
928 MultiExprArg Exprs,
929 SourceLocation RParenLoc) {
930 QualType Ty = TInfo->getType();
931 SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();
932
933 if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) {
934 return CXXUnresolvedConstructExpr::Create(Context, TInfo, LParenLoc, Exprs,
935 RParenLoc);
936 }
937
938 bool ListInitialization = LParenLoc.isInvalid();
939 assert((!ListInitialization || (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0])))
940 && "List initialization must have initializer list as expression.");
941 SourceRange FullRange = SourceRange(TyBeginLoc,
942 ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc);
943
944 // C++ [expr.type.conv]p1:
945 // If the expression list is a single expression, the type conversion
946 // expression is equivalent (in definedness, and if defined in meaning) to the
947 // corresponding cast expression.
948 if (Exprs.size() == 1 && !ListInitialization) {
949 Expr *Arg = Exprs[0];
950 return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc);
951 }
952
953 QualType ElemTy = Ty;
954 if (Ty->isArrayType()) {
955 if (!ListInitialization)
956 return ExprError(Diag(TyBeginLoc,
957 diag::err_value_init_for_array_type) << FullRange);
958 ElemTy = Context.getBaseElementType(Ty);
959 }
960
961 if (!Ty->isVoidType() &&
962 RequireCompleteType(TyBeginLoc, ElemTy,
963 diag::err_invalid_incomplete_type_use, FullRange))
964 return ExprError();
965
966 if (RequireNonAbstractType(TyBeginLoc, Ty,
967 diag::err_allocation_of_abstract_type))
968 return ExprError();
969
970 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo);
971 InitializationKind Kind =
972 Exprs.size() ? ListInitialization
973 ? InitializationKind::CreateDirectList(TyBeginLoc)
974 : InitializationKind::CreateDirect(TyBeginLoc, LParenLoc, RParenLoc)
975 : InitializationKind::CreateValue(TyBeginLoc, LParenLoc, RParenLoc);
976 InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
977 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);
978
979 if (Result.isInvalid() || !ListInitialization)
980 return Result;
981
982 Expr *Inner = Result.get();
983 if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
984 Inner = BTE->getSubExpr();
985 if (isa<InitListExpr>(Inner)) {
986 // If the list-initialization doesn't involve a constructor call, we'll get
987 // the initializer-list (with corrected type) back, but that's not what we
988 // want, since it will be treated as an initializer list in further
989 // processing. Explicitly insert a cast here.
990 QualType ResultType = Result.get()->getType();
991 Result = CXXFunctionalCastExpr::Create(
992 Context, ResultType, Expr::getValueKindForType(TInfo->getType()), TInfo,
993 CK_NoOp, Result.get(), /*Path=*/nullptr, LParenLoc, RParenLoc);
994 }
995
996 // FIXME: Improve AST representation?
997 return Result;
998 }
999
1000 /// doesUsualArrayDeleteWantSize - Answers whether the usual
1001 /// operator delete[] for the given type has a size_t parameter.
doesUsualArrayDeleteWantSize(Sema & S,SourceLocation loc,QualType allocType)1002 static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc,
1003 QualType allocType) {
1004 const RecordType *record =
1005 allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
1006 if (!record) return false;
1007
1008 // Try to find an operator delete[] in class scope.
1009
1010 DeclarationName deleteName =
1011 S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
1012 LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
1013 S.LookupQualifiedName(ops, record->getDecl());
1014
1015 // We're just doing this for information.
1016 ops.suppressDiagnostics();
1017
1018 // Very likely: there's no operator delete[].
1019 if (ops.empty()) return false;
1020
1021 // If it's ambiguous, it should be illegal to call operator delete[]
1022 // on this thing, so it doesn't matter if we allocate extra space or not.
1023 if (ops.isAmbiguous()) return false;
1024
1025 LookupResult::Filter filter = ops.makeFilter();
1026 while (filter.hasNext()) {
1027 NamedDecl *del = filter.next()->getUnderlyingDecl();
1028
1029 // C++0x [basic.stc.dynamic.deallocation]p2:
1030 // A template instance is never a usual deallocation function,
1031 // regardless of its signature.
1032 if (isa<FunctionTemplateDecl>(del)) {
1033 filter.erase();
1034 continue;
1035 }
1036
1037 // C++0x [basic.stc.dynamic.deallocation]p2:
1038 // If class T does not declare [an operator delete[] with one
1039 // parameter] but does declare a member deallocation function
1040 // named operator delete[] with exactly two parameters, the
1041 // second of which has type std::size_t, then this function
1042 // is a usual deallocation function.
1043 if (!cast<CXXMethodDecl>(del)->isUsualDeallocationFunction()) {
1044 filter.erase();
1045 continue;
1046 }
1047 }
1048 filter.done();
1049
1050 if (!ops.isSingleResult()) return false;
1051
1052 const FunctionDecl *del = cast<FunctionDecl>(ops.getFoundDecl());
1053 return (del->getNumParams() == 2);
1054 }
1055
1056 /// \brief Parsed a C++ 'new' expression (C++ 5.3.4).
1057 ///
1058 /// E.g.:
1059 /// @code new (memory) int[size][4] @endcode
1060 /// or
1061 /// @code ::new Foo(23, "hello") @endcode
1062 ///
1063 /// \param StartLoc The first location of the expression.
1064 /// \param UseGlobal True if 'new' was prefixed with '::'.
1065 /// \param PlacementLParen Opening paren of the placement arguments.
1066 /// \param PlacementArgs Placement new arguments.
1067 /// \param PlacementRParen Closing paren of the placement arguments.
1068 /// \param TypeIdParens If the type is in parens, the source range.
1069 /// \param D The type to be allocated, as well as array dimensions.
1070 /// \param Initializer The initializing expression or initializer-list, or null
1071 /// if there is none.
1072 ExprResult
ActOnCXXNew(SourceLocation StartLoc,bool UseGlobal,SourceLocation PlacementLParen,MultiExprArg PlacementArgs,SourceLocation PlacementRParen,SourceRange TypeIdParens,Declarator & D,Expr * Initializer)1073 Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
1074 SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
1075 SourceLocation PlacementRParen, SourceRange TypeIdParens,
1076 Declarator &D, Expr *Initializer) {
1077 bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType();
1078
1079 Expr *ArraySize = nullptr;
1080 // If the specified type is an array, unwrap it and save the expression.
1081 if (D.getNumTypeObjects() > 0 &&
1082 D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
1083 DeclaratorChunk &Chunk = D.getTypeObject(0);
1084 if (TypeContainsAuto)
1085 return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
1086 << D.getSourceRange());
1087 if (Chunk.Arr.hasStatic)
1088 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
1089 << D.getSourceRange());
1090 if (!Chunk.Arr.NumElts)
1091 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
1092 << D.getSourceRange());
1093
1094 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
1095 D.DropFirstTypeObject();
1096 }
1097
1098 // Every dimension shall be of constant size.
1099 if (ArraySize) {
1100 for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
1101 if (D.getTypeObject(I).Kind != DeclaratorChunk::Array)
1102 break;
1103
1104 DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr;
1105 if (Expr *NumElts = (Expr *)Array.NumElts) {
1106 if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
1107 if (getLangOpts().CPlusPlus14) {
1108 // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
1109 // shall be a converted constant expression (5.19) of type std::size_t
1110 // and shall evaluate to a strictly positive value.
1111 unsigned IntWidth = Context.getTargetInfo().getIntWidth();
1112 assert(IntWidth && "Builtin type of size 0?");
1113 llvm::APSInt Value(IntWidth);
1114 Array.NumElts
1115 = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value,
1116 CCEK_NewExpr)
1117 .get();
1118 } else {
1119 Array.NumElts
1120 = VerifyIntegerConstantExpression(NumElts, nullptr,
1121 diag::err_new_array_nonconst)
1122 .get();
1123 }
1124 if (!Array.NumElts)
1125 return ExprError();
1126 }
1127 }
1128 }
1129 }
1130
1131 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
1132 QualType AllocType = TInfo->getType();
1133 if (D.isInvalidType())
1134 return ExprError();
1135
1136 SourceRange DirectInitRange;
1137 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
1138 DirectInitRange = List->getSourceRange();
1139
1140 return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal,
1141 PlacementLParen,
1142 PlacementArgs,
1143 PlacementRParen,
1144 TypeIdParens,
1145 AllocType,
1146 TInfo,
1147 ArraySize,
1148 DirectInitRange,
1149 Initializer,
1150 TypeContainsAuto);
1151 }
1152
isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style,Expr * Init)1153 static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style,
1154 Expr *Init) {
1155 if (!Init)
1156 return true;
1157 if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
1158 return PLE->getNumExprs() == 0;
1159 if (isa<ImplicitValueInitExpr>(Init))
1160 return true;
1161 else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
1162 return !CCE->isListInitialization() &&
1163 CCE->getConstructor()->isDefaultConstructor();
1164 else if (Style == CXXNewExpr::ListInit) {
1165 assert(isa<InitListExpr>(Init) &&
1166 "Shouldn't create list CXXConstructExprs for arrays.");
1167 return true;
1168 }
1169 return false;
1170 }
1171
1172 ExprResult
BuildCXXNew(SourceRange Range,bool UseGlobal,SourceLocation PlacementLParen,MultiExprArg PlacementArgs,SourceLocation PlacementRParen,SourceRange TypeIdParens,QualType AllocType,TypeSourceInfo * AllocTypeInfo,Expr * ArraySize,SourceRange DirectInitRange,Expr * Initializer,bool TypeMayContainAuto)1173 Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
1174 SourceLocation PlacementLParen,
1175 MultiExprArg PlacementArgs,
1176 SourceLocation PlacementRParen,
1177 SourceRange TypeIdParens,
1178 QualType AllocType,
1179 TypeSourceInfo *AllocTypeInfo,
1180 Expr *ArraySize,
1181 SourceRange DirectInitRange,
1182 Expr *Initializer,
1183 bool TypeMayContainAuto) {
1184 SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
1185 SourceLocation StartLoc = Range.getBegin();
1186
1187 CXXNewExpr::InitializationStyle initStyle;
1188 if (DirectInitRange.isValid()) {
1189 assert(Initializer && "Have parens but no initializer.");
1190 initStyle = CXXNewExpr::CallInit;
1191 } else if (Initializer && isa<InitListExpr>(Initializer))
1192 initStyle = CXXNewExpr::ListInit;
1193 else {
1194 assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||
1195 isa<CXXConstructExpr>(Initializer)) &&
1196 "Initializer expression that cannot have been implicitly created.");
1197 initStyle = CXXNewExpr::NoInit;
1198 }
1199
1200 Expr **Inits = &Initializer;
1201 unsigned NumInits = Initializer ? 1 : 0;
1202 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
1203 assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init");
1204 Inits = List->getExprs();
1205 NumInits = List->getNumExprs();
1206 }
1207
1208 // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
1209 if (TypeMayContainAuto && AllocType->isUndeducedType()) {
1210 if (initStyle == CXXNewExpr::NoInit || NumInits == 0)
1211 return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
1212 << AllocType << TypeRange);
1213 if (initStyle == CXXNewExpr::ListInit ||
1214 (NumInits == 1 && isa<InitListExpr>(Inits[0])))
1215 return ExprError(Diag(Inits[0]->getLocStart(),
1216 diag::err_auto_new_list_init)
1217 << AllocType << TypeRange);
1218 if (NumInits > 1) {
1219 Expr *FirstBad = Inits[1];
1220 return ExprError(Diag(FirstBad->getLocStart(),
1221 diag::err_auto_new_ctor_multiple_expressions)
1222 << AllocType << TypeRange);
1223 }
1224 Expr *Deduce = Inits[0];
1225 QualType DeducedType;
1226 if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed)
1227 return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
1228 << AllocType << Deduce->getType()
1229 << TypeRange << Deduce->getSourceRange());
1230 if (DeducedType.isNull())
1231 return ExprError();
1232 AllocType = DeducedType;
1233 }
1234
1235 // Per C++0x [expr.new]p5, the type being constructed may be a
1236 // typedef of an array type.
1237 if (!ArraySize) {
1238 if (const ConstantArrayType *Array
1239 = Context.getAsConstantArrayType(AllocType)) {
1240 ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
1241 Context.getSizeType(),
1242 TypeRange.getEnd());
1243 AllocType = Array->getElementType();
1244 }
1245 }
1246
1247 if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
1248 return ExprError();
1249
1250 if (initStyle == CXXNewExpr::ListInit &&
1251 isStdInitializerList(AllocType, nullptr)) {
1252 Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(),
1253 diag::warn_dangling_std_initializer_list)
1254 << /*at end of FE*/0 << Inits[0]->getSourceRange();
1255 }
1256
1257 // In ARC, infer 'retaining' for the allocated
1258 if (getLangOpts().ObjCAutoRefCount &&
1259 AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
1260 AllocType->isObjCLifetimeType()) {
1261 AllocType = Context.getLifetimeQualifiedType(AllocType,
1262 AllocType->getObjCARCImplicitLifetime());
1263 }
1264
1265 QualType ResultType = Context.getPointerType(AllocType);
1266
1267 if (ArraySize && ArraySize->getType()->isNonOverloadPlaceholderType()) {
1268 ExprResult result = CheckPlaceholderExpr(ArraySize);
1269 if (result.isInvalid()) return ExprError();
1270 ArraySize = result.get();
1271 }
1272 // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
1273 // integral or enumeration type with a non-negative value."
1274 // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
1275 // enumeration type, or a class type for which a single non-explicit
1276 // conversion function to integral or unscoped enumeration type exists.
1277 // C++1y [expr.new]p6: The expression [...] is implicitly converted to
1278 // std::size_t.
1279 if (ArraySize && !ArraySize->isTypeDependent()) {
1280 ExprResult ConvertedSize;
1281 if (getLangOpts().CPlusPlus14) {
1282 assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?");
1283
1284 ConvertedSize = PerformImplicitConversion(ArraySize, Context.getSizeType(),
1285 AA_Converting);
1286
1287 if (!ConvertedSize.isInvalid() &&
1288 ArraySize->getType()->getAs<RecordType>())
1289 // Diagnose the compatibility of this conversion.
1290 Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
1291 << ArraySize->getType() << 0 << "'size_t'";
1292 } else {
1293 class SizeConvertDiagnoser : public ICEConvertDiagnoser {
1294 protected:
1295 Expr *ArraySize;
1296
1297 public:
1298 SizeConvertDiagnoser(Expr *ArraySize)
1299 : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
1300 ArraySize(ArraySize) {}
1301
1302 SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
1303 QualType T) override {
1304 return S.Diag(Loc, diag::err_array_size_not_integral)
1305 << S.getLangOpts().CPlusPlus11 << T;
1306 }
1307
1308 SemaDiagnosticBuilder diagnoseIncomplete(
1309 Sema &S, SourceLocation Loc, QualType T) override {
1310 return S.Diag(Loc, diag::err_array_size_incomplete_type)
1311 << T << ArraySize->getSourceRange();
1312 }
1313
1314 SemaDiagnosticBuilder diagnoseExplicitConv(
1315 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
1316 return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
1317 }
1318
1319 SemaDiagnosticBuilder noteExplicitConv(
1320 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
1321 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
1322 << ConvTy->isEnumeralType() << ConvTy;
1323 }
1324
1325 SemaDiagnosticBuilder diagnoseAmbiguous(
1326 Sema &S, SourceLocation Loc, QualType T) override {
1327 return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
1328 }
1329
1330 SemaDiagnosticBuilder noteAmbiguous(
1331 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
1332 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
1333 << ConvTy->isEnumeralType() << ConvTy;
1334 }
1335
1336 virtual SemaDiagnosticBuilder diagnoseConversion(
1337 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
1338 return S.Diag(Loc,
1339 S.getLangOpts().CPlusPlus11
1340 ? diag::warn_cxx98_compat_array_size_conversion
1341 : diag::ext_array_size_conversion)
1342 << T << ConvTy->isEnumeralType() << ConvTy;
1343 }
1344 } SizeDiagnoser(ArraySize);
1345
1346 ConvertedSize = PerformContextualImplicitConversion(StartLoc, ArraySize,
1347 SizeDiagnoser);
1348 }
1349 if (ConvertedSize.isInvalid())
1350 return ExprError();
1351
1352 ArraySize = ConvertedSize.get();
1353 QualType SizeType = ArraySize->getType();
1354
1355 if (!SizeType->isIntegralOrUnscopedEnumerationType())
1356 return ExprError();
1357
1358 // C++98 [expr.new]p7:
1359 // The expression in a direct-new-declarator shall have integral type
1360 // with a non-negative value.
1361 //
1362 // Let's see if this is a constant < 0. If so, we reject it out of
1363 // hand. Otherwise, if it's not a constant, we must have an unparenthesized
1364 // array type.
1365 //
1366 // Note: such a construct has well-defined semantics in C++11: it throws
1367 // std::bad_array_new_length.
1368 if (!ArraySize->isValueDependent()) {
1369 llvm::APSInt Value;
1370 // We've already performed any required implicit conversion to integer or
1371 // unscoped enumeration type.
1372 if (ArraySize->isIntegerConstantExpr(Value, Context)) {
1373 if (Value < llvm::APSInt(
1374 llvm::APInt::getNullValue(Value.getBitWidth()),
1375 Value.isUnsigned())) {
1376 if (getLangOpts().CPlusPlus11)
1377 Diag(ArraySize->getLocStart(),
1378 diag::warn_typecheck_negative_array_new_size)
1379 << ArraySize->getSourceRange();
1380 else
1381 return ExprError(Diag(ArraySize->getLocStart(),
1382 diag::err_typecheck_negative_array_size)
1383 << ArraySize->getSourceRange());
1384 } else if (!AllocType->isDependentType()) {
1385 unsigned ActiveSizeBits =
1386 ConstantArrayType::getNumAddressingBits(Context, AllocType, Value);
1387 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
1388 if (getLangOpts().CPlusPlus11)
1389 Diag(ArraySize->getLocStart(),
1390 diag::warn_array_new_too_large)
1391 << Value.toString(10)
1392 << ArraySize->getSourceRange();
1393 else
1394 return ExprError(Diag(ArraySize->getLocStart(),
1395 diag::err_array_too_large)
1396 << Value.toString(10)
1397 << ArraySize->getSourceRange());
1398 }
1399 }
1400 } else if (TypeIdParens.isValid()) {
1401 // Can't have dynamic array size when the type-id is in parentheses.
1402 Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst)
1403 << ArraySize->getSourceRange()
1404 << FixItHint::CreateRemoval(TypeIdParens.getBegin())
1405 << FixItHint::CreateRemoval(TypeIdParens.getEnd());
1406
1407 TypeIdParens = SourceRange();
1408 }
1409 }
1410
1411 // Note that we do *not* convert the argument in any way. It can
1412 // be signed, larger than size_t, whatever.
1413 }
1414
1415 FunctionDecl *OperatorNew = nullptr;
1416 FunctionDecl *OperatorDelete = nullptr;
1417
1418 if (!AllocType->isDependentType() &&
1419 !Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
1420 FindAllocationFunctions(StartLoc,
1421 SourceRange(PlacementLParen, PlacementRParen),
1422 UseGlobal, AllocType, ArraySize, PlacementArgs,
1423 OperatorNew, OperatorDelete))
1424 return ExprError();
1425
1426 // If this is an array allocation, compute whether the usual array
1427 // deallocation function for the type has a size_t parameter.
1428 bool UsualArrayDeleteWantsSize = false;
1429 if (ArraySize && !AllocType->isDependentType())
1430 UsualArrayDeleteWantsSize
1431 = doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);
1432
1433 SmallVector<Expr *, 8> AllPlaceArgs;
1434 if (OperatorNew) {
1435 const FunctionProtoType *Proto =
1436 OperatorNew->getType()->getAs<FunctionProtoType>();
1437 VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
1438 : VariadicDoesNotApply;
1439
1440 // We've already converted the placement args, just fill in any default
1441 // arguments. Skip the first parameter because we don't have a corresponding
1442 // argument.
1443 if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, 1,
1444 PlacementArgs, AllPlaceArgs, CallType))
1445 return ExprError();
1446
1447 if (!AllPlaceArgs.empty())
1448 PlacementArgs = AllPlaceArgs;
1449
1450 // FIXME: This is wrong: PlacementArgs misses out the first (size) argument.
1451 DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs);
1452
1453 // FIXME: Missing call to CheckFunctionCall or equivalent
1454 }
1455
1456 // Warn if the type is over-aligned and is being allocated by global operator
1457 // new.
1458 if (PlacementArgs.empty() && OperatorNew &&
1459 (OperatorNew->isImplicit() ||
1460 getSourceManager().isInSystemHeader(OperatorNew->getLocStart()))) {
1461 if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){
1462 unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign();
1463 if (Align > SuitableAlign)
1464 Diag(StartLoc, diag::warn_overaligned_type)
1465 << AllocType
1466 << unsigned(Align / Context.getCharWidth())
1467 << unsigned(SuitableAlign / Context.getCharWidth());
1468 }
1469 }
1470
1471 QualType InitType = AllocType;
1472 // Array 'new' can't have any initializers except empty parentheses.
1473 // Initializer lists are also allowed, in C++11. Rely on the parser for the
1474 // dialect distinction.
1475 if (ResultType->isArrayType() || ArraySize) {
1476 if (!isLegalArrayNewInitializer(initStyle, Initializer)) {
1477 SourceRange InitRange(Inits[0]->getLocStart(),
1478 Inits[NumInits - 1]->getLocEnd());
1479 Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
1480 return ExprError();
1481 }
1482 if (InitListExpr *ILE = dyn_cast_or_null<InitListExpr>(Initializer)) {
1483 // We do the initialization typechecking against the array type
1484 // corresponding to the number of initializers + 1 (to also check
1485 // default-initialization).
1486 unsigned NumElements = ILE->getNumInits() + 1;
1487 InitType = Context.getConstantArrayType(AllocType,
1488 llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements),
1489 ArrayType::Normal, 0);
1490 }
1491 }
1492
1493 // If we can perform the initialization, and we've not already done so,
1494 // do it now.
1495 if (!AllocType->isDependentType() &&
1496 !Expr::hasAnyTypeDependentArguments(
1497 llvm::makeArrayRef(Inits, NumInits))) {
1498 // C++11 [expr.new]p15:
1499 // A new-expression that creates an object of type T initializes that
1500 // object as follows:
1501 InitializationKind Kind
1502 // - If the new-initializer is omitted, the object is default-
1503 // initialized (8.5); if no initialization is performed,
1504 // the object has indeterminate value
1505 = initStyle == CXXNewExpr::NoInit
1506 ? InitializationKind::CreateDefault(TypeRange.getBegin())
1507 // - Otherwise, the new-initializer is interpreted according to the
1508 // initialization rules of 8.5 for direct-initialization.
1509 : initStyle == CXXNewExpr::ListInit
1510 ? InitializationKind::CreateDirectList(TypeRange.getBegin())
1511 : InitializationKind::CreateDirect(TypeRange.getBegin(),
1512 DirectInitRange.getBegin(),
1513 DirectInitRange.getEnd());
1514
1515 InitializedEntity Entity
1516 = InitializedEntity::InitializeNew(StartLoc, InitType);
1517 InitializationSequence InitSeq(*this, Entity, Kind, MultiExprArg(Inits, NumInits));
1518 ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind,
1519 MultiExprArg(Inits, NumInits));
1520 if (FullInit.isInvalid())
1521 return ExprError();
1522
1523 // FullInit is our initializer; strip off CXXBindTemporaryExprs, because
1524 // we don't want the initialized object to be destructed.
1525 if (CXXBindTemporaryExpr *Binder =
1526 dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
1527 FullInit = Binder->getSubExpr();
1528
1529 Initializer = FullInit.get();
1530 }
1531
1532 // Mark the new and delete operators as referenced.
1533 if (OperatorNew) {
1534 if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
1535 return ExprError();
1536 MarkFunctionReferenced(StartLoc, OperatorNew);
1537 }
1538 if (OperatorDelete) {
1539 if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
1540 return ExprError();
1541 MarkFunctionReferenced(StartLoc, OperatorDelete);
1542 }
1543
1544 // C++0x [expr.new]p17:
1545 // If the new expression creates an array of objects of class type,
1546 // access and ambiguity control are done for the destructor.
1547 QualType BaseAllocType = Context.getBaseElementType(AllocType);
1548 if (ArraySize && !BaseAllocType->isDependentType()) {
1549 if (const RecordType *BaseRecordType = BaseAllocType->getAs<RecordType>()) {
1550 if (CXXDestructorDecl *dtor = LookupDestructor(
1551 cast<CXXRecordDecl>(BaseRecordType->getDecl()))) {
1552 MarkFunctionReferenced(StartLoc, dtor);
1553 CheckDestructorAccess(StartLoc, dtor,
1554 PDiag(diag::err_access_dtor)
1555 << BaseAllocType);
1556 if (DiagnoseUseOfDecl(dtor, StartLoc))
1557 return ExprError();
1558 }
1559 }
1560 }
1561
1562 return new (Context)
1563 CXXNewExpr(Context, UseGlobal, OperatorNew, OperatorDelete,
1564 UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens,
1565 ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo,
1566 Range, DirectInitRange);
1567 }
1568
1569 /// \brief Checks that a type is suitable as the allocated type
1570 /// in a new-expression.
CheckAllocatedType(QualType AllocType,SourceLocation Loc,SourceRange R)1571 bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc,
1572 SourceRange R) {
1573 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
1574 // abstract class type or array thereof.
1575 if (AllocType->isFunctionType())
1576 return Diag(Loc, diag::err_bad_new_type)
1577 << AllocType << 0 << R;
1578 else if (AllocType->isReferenceType())
1579 return Diag(Loc, diag::err_bad_new_type)
1580 << AllocType << 1 << R;
1581 else if (!AllocType->isDependentType() &&
1582 RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R))
1583 return true;
1584 else if (RequireNonAbstractType(Loc, AllocType,
1585 diag::err_allocation_of_abstract_type))
1586 return true;
1587 else if (AllocType->isVariablyModifiedType())
1588 return Diag(Loc, diag::err_variably_modified_new_type)
1589 << AllocType;
1590 else if (unsigned AddressSpace = AllocType.getAddressSpace())
1591 return Diag(Loc, diag::err_address_space_qualified_new)
1592 << AllocType.getUnqualifiedType() << AddressSpace;
1593 else if (getLangOpts().ObjCAutoRefCount) {
1594 if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
1595 QualType BaseAllocType = Context.getBaseElementType(AT);
1596 if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
1597 BaseAllocType->isObjCLifetimeType())
1598 return Diag(Loc, diag::err_arc_new_array_without_ownership)
1599 << BaseAllocType;
1600 }
1601 }
1602
1603 return false;
1604 }
1605
1606 /// \brief Determine whether the given function is a non-placement
1607 /// deallocation function.
isNonPlacementDeallocationFunction(Sema & S,FunctionDecl * FD)1608 static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) {
1609 if (FD->isInvalidDecl())
1610 return false;
1611
1612 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
1613 return Method->isUsualDeallocationFunction();
1614
1615 if (FD->getOverloadedOperator() != OO_Delete &&
1616 FD->getOverloadedOperator() != OO_Array_Delete)
1617 return false;
1618
1619 if (FD->getNumParams() == 1)
1620 return true;
1621
1622 return S.getLangOpts().SizedDeallocation && FD->getNumParams() == 2 &&
1623 S.Context.hasSameUnqualifiedType(FD->getParamDecl(1)->getType(),
1624 S.Context.getSizeType());
1625 }
1626
1627 /// FindAllocationFunctions - Finds the overloads of operator new and delete
1628 /// that are appropriate for the allocation.
FindAllocationFunctions(SourceLocation StartLoc,SourceRange Range,bool UseGlobal,QualType AllocType,bool IsArray,MultiExprArg PlaceArgs,FunctionDecl * & OperatorNew,FunctionDecl * & OperatorDelete)1629 bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
1630 bool UseGlobal, QualType AllocType,
1631 bool IsArray, MultiExprArg PlaceArgs,
1632 FunctionDecl *&OperatorNew,
1633 FunctionDecl *&OperatorDelete) {
1634 // --- Choosing an allocation function ---
1635 // C++ 5.3.4p8 - 14 & 18
1636 // 1) If UseGlobal is true, only look in the global scope. Else, also look
1637 // in the scope of the allocated class.
1638 // 2) If an array size is given, look for operator new[], else look for
1639 // operator new.
1640 // 3) The first argument is always size_t. Append the arguments from the
1641 // placement form.
1642
1643 SmallVector<Expr*, 8> AllocArgs(1 + PlaceArgs.size());
1644 // We don't care about the actual value of this argument.
1645 // FIXME: Should the Sema create the expression and embed it in the syntax
1646 // tree? Or should the consumer just recalculate the value?
1647 IntegerLiteral Size(Context, llvm::APInt::getNullValue(
1648 Context.getTargetInfo().getPointerWidth(0)),
1649 Context.getSizeType(),
1650 SourceLocation());
1651 AllocArgs[0] = &Size;
1652 std::copy(PlaceArgs.begin(), PlaceArgs.end(), AllocArgs.begin() + 1);
1653
1654 // C++ [expr.new]p8:
1655 // If the allocated type is a non-array type, the allocation
1656 // function's name is operator new and the deallocation function's
1657 // name is operator delete. If the allocated type is an array
1658 // type, the allocation function's name is operator new[] and the
1659 // deallocation function's name is operator delete[].
1660 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
1661 IsArray ? OO_Array_New : OO_New);
1662 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
1663 IsArray ? OO_Array_Delete : OO_Delete);
1664
1665 QualType AllocElemType = Context.getBaseElementType(AllocType);
1666
1667 if (AllocElemType->isRecordType() && !UseGlobal) {
1668 CXXRecordDecl *Record
1669 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl());
1670 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, Record,
1671 /*AllowMissing=*/true, OperatorNew))
1672 return true;
1673 }
1674
1675 if (!OperatorNew) {
1676 // Didn't find a member overload. Look for a global one.
1677 DeclareGlobalNewDelete();
1678 DeclContext *TUDecl = Context.getTranslationUnitDecl();
1679 bool FallbackEnabled = IsArray && Context.getLangOpts().MSVCCompat;
1680 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl,
1681 /*AllowMissing=*/FallbackEnabled, OperatorNew,
1682 /*Diagnose=*/!FallbackEnabled)) {
1683 if (!FallbackEnabled)
1684 return true;
1685
1686 // MSVC will fall back on trying to find a matching global operator new
1687 // if operator new[] cannot be found. Also, MSVC will leak by not
1688 // generating a call to operator delete or operator delete[], but we
1689 // will not replicate that bug.
1690 NewName = Context.DeclarationNames.getCXXOperatorName(OO_New);
1691 DeleteName = Context.DeclarationNames.getCXXOperatorName(OO_Delete);
1692 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl,
1693 /*AllowMissing=*/false, OperatorNew))
1694 return true;
1695 }
1696 }
1697
1698 // We don't need an operator delete if we're running under
1699 // -fno-exceptions.
1700 if (!getLangOpts().Exceptions) {
1701 OperatorDelete = nullptr;
1702 return false;
1703 }
1704
1705 // C++ [expr.new]p19:
1706 //
1707 // If the new-expression begins with a unary :: operator, the
1708 // deallocation function's name is looked up in the global
1709 // scope. Otherwise, if the allocated type is a class type T or an
1710 // array thereof, the deallocation function's name is looked up in
1711 // the scope of T. If this lookup fails to find the name, or if
1712 // the allocated type is not a class type or array thereof, the
1713 // deallocation function's name is looked up in the global scope.
1714 LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
1715 if (AllocElemType->isRecordType() && !UseGlobal) {
1716 CXXRecordDecl *RD
1717 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl());
1718 LookupQualifiedName(FoundDelete, RD);
1719 }
1720 if (FoundDelete.isAmbiguous())
1721 return true; // FIXME: clean up expressions?
1722
1723 if (FoundDelete.empty()) {
1724 DeclareGlobalNewDelete();
1725 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
1726 }
1727
1728 FoundDelete.suppressDiagnostics();
1729
1730 SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches;
1731
1732 // Whether we're looking for a placement operator delete is dictated
1733 // by whether we selected a placement operator new, not by whether
1734 // we had explicit placement arguments. This matters for things like
1735 // struct A { void *operator new(size_t, int = 0); ... };
1736 // A *a = new A()
1737 bool isPlacementNew = (!PlaceArgs.empty() || OperatorNew->param_size() != 1);
1738
1739 if (isPlacementNew) {
1740 // C++ [expr.new]p20:
1741 // A declaration of a placement deallocation function matches the
1742 // declaration of a placement allocation function if it has the
1743 // same number of parameters and, after parameter transformations
1744 // (8.3.5), all parameter types except the first are
1745 // identical. [...]
1746 //
1747 // To perform this comparison, we compute the function type that
1748 // the deallocation function should have, and use that type both
1749 // for template argument deduction and for comparison purposes.
1750 //
1751 // FIXME: this comparison should ignore CC and the like.
1752 QualType ExpectedFunctionType;
1753 {
1754 const FunctionProtoType *Proto
1755 = OperatorNew->getType()->getAs<FunctionProtoType>();
1756
1757 SmallVector<QualType, 4> ArgTypes;
1758 ArgTypes.push_back(Context.VoidPtrTy);
1759 for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
1760 ArgTypes.push_back(Proto->getParamType(I));
1761
1762 FunctionProtoType::ExtProtoInfo EPI;
1763 EPI.Variadic = Proto->isVariadic();
1764
1765 ExpectedFunctionType
1766 = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
1767 }
1768
1769 for (LookupResult::iterator D = FoundDelete.begin(),
1770 DEnd = FoundDelete.end();
1771 D != DEnd; ++D) {
1772 FunctionDecl *Fn = nullptr;
1773 if (FunctionTemplateDecl *FnTmpl
1774 = dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
1775 // Perform template argument deduction to try to match the
1776 // expected function type.
1777 TemplateDeductionInfo Info(StartLoc);
1778 if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
1779 Info))
1780 continue;
1781 } else
1782 Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());
1783
1784 if (Context.hasSameType(Fn->getType(), ExpectedFunctionType))
1785 Matches.push_back(std::make_pair(D.getPair(), Fn));
1786 }
1787 } else {
1788 // C++ [expr.new]p20:
1789 // [...] Any non-placement deallocation function matches a
1790 // non-placement allocation function. [...]
1791 for (LookupResult::iterator D = FoundDelete.begin(),
1792 DEnd = FoundDelete.end();
1793 D != DEnd; ++D) {
1794 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>((*D)->getUnderlyingDecl()))
1795 if (isNonPlacementDeallocationFunction(*this, Fn))
1796 Matches.push_back(std::make_pair(D.getPair(), Fn));
1797 }
1798
1799 // C++1y [expr.new]p22:
1800 // For a non-placement allocation function, the normal deallocation
1801 // function lookup is used
1802 // C++1y [expr.delete]p?:
1803 // If [...] deallocation function lookup finds both a usual deallocation
1804 // function with only a pointer parameter and a usual deallocation
1805 // function with both a pointer parameter and a size parameter, then the
1806 // selected deallocation function shall be the one with two parameters.
1807 // Otherwise, the selected deallocation function shall be the function
1808 // with one parameter.
1809 if (getLangOpts().SizedDeallocation && Matches.size() == 2) {
1810 if (Matches[0].second->getNumParams() == 1)
1811 Matches.erase(Matches.begin());
1812 else
1813 Matches.erase(Matches.begin() + 1);
1814 assert(Matches[0].second->getNumParams() == 2 &&
1815 "found an unexpected usual deallocation function");
1816 }
1817 }
1818
1819 // C++ [expr.new]p20:
1820 // [...] If the lookup finds a single matching deallocation
1821 // function, that function will be called; otherwise, no
1822 // deallocation function will be called.
1823 if (Matches.size() == 1) {
1824 OperatorDelete = Matches[0].second;
1825
1826 // C++0x [expr.new]p20:
1827 // If the lookup finds the two-parameter form of a usual
1828 // deallocation function (3.7.4.2) and that function, considered
1829 // as a placement deallocation function, would have been
1830 // selected as a match for the allocation function, the program
1831 // is ill-formed.
1832 if (!PlaceArgs.empty() && getLangOpts().CPlusPlus11 &&
1833 isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
1834 Diag(StartLoc, diag::err_placement_new_non_placement_delete)
1835 << SourceRange(PlaceArgs.front()->getLocStart(),
1836 PlaceArgs.back()->getLocEnd());
1837 if (!OperatorDelete->isImplicit())
1838 Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
1839 << DeleteName;
1840 } else {
1841 CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
1842 Matches[0].first);
1843 }
1844 }
1845
1846 return false;
1847 }
1848
1849 /// \brief Find an fitting overload for the allocation function
1850 /// in the specified scope.
1851 ///
1852 /// \param StartLoc The location of the 'new' token.
1853 /// \param Range The range of the placement arguments.
1854 /// \param Name The name of the function ('operator new' or 'operator new[]').
1855 /// \param Args The placement arguments specified.
1856 /// \param Ctx The scope in which we should search; either a class scope or the
1857 /// translation unit.
1858 /// \param AllowMissing If \c true, report an error if we can't find any
1859 /// allocation functions. Otherwise, succeed but don't fill in \p
1860 /// Operator.
1861 /// \param Operator Filled in with the found allocation function. Unchanged if
1862 /// no allocation function was found.
1863 /// \param Diagnose If \c true, issue errors if the allocation function is not
1864 /// usable.
FindAllocationOverload(SourceLocation StartLoc,SourceRange Range,DeclarationName Name,MultiExprArg Args,DeclContext * Ctx,bool AllowMissing,FunctionDecl * & Operator,bool Diagnose)1865 bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range,
1866 DeclarationName Name, MultiExprArg Args,
1867 DeclContext *Ctx,
1868 bool AllowMissing, FunctionDecl *&Operator,
1869 bool Diagnose) {
1870 LookupResult R(*this, Name, StartLoc, LookupOrdinaryName);
1871 LookupQualifiedName(R, Ctx);
1872 if (R.empty()) {
1873 if (AllowMissing || !Diagnose)
1874 return false;
1875 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
1876 << Name << Range;
1877 }
1878
1879 if (R.isAmbiguous())
1880 return true;
1881
1882 R.suppressDiagnostics();
1883
1884 OverloadCandidateSet Candidates(StartLoc, OverloadCandidateSet::CSK_Normal);
1885 for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
1886 Alloc != AllocEnd; ++Alloc) {
1887 // Even member operator new/delete are implicitly treated as
1888 // static, so don't use AddMemberCandidate.
1889 NamedDecl *D = (*Alloc)->getUnderlyingDecl();
1890
1891 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
1892 AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
1893 /*ExplicitTemplateArgs=*/nullptr,
1894 Args, Candidates,
1895 /*SuppressUserConversions=*/false);
1896 continue;
1897 }
1898
1899 FunctionDecl *Fn = cast<FunctionDecl>(D);
1900 AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
1901 /*SuppressUserConversions=*/false);
1902 }
1903
1904 // Do the resolution.
1905 OverloadCandidateSet::iterator Best;
1906 switch (Candidates.BestViableFunction(*this, StartLoc, Best)) {
1907 case OR_Success: {
1908 // Got one!
1909 FunctionDecl *FnDecl = Best->Function;
1910 if (CheckAllocationAccess(StartLoc, Range, R.getNamingClass(),
1911 Best->FoundDecl, Diagnose) == AR_inaccessible)
1912 return true;
1913
1914 Operator = FnDecl;
1915 return false;
1916 }
1917
1918 case OR_No_Viable_Function:
1919 if (Diagnose) {
1920 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
1921 << Name << Range;
1922 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args);
1923 }
1924 return true;
1925
1926 case OR_Ambiguous:
1927 if (Diagnose) {
1928 Diag(StartLoc, diag::err_ovl_ambiguous_call)
1929 << Name << Range;
1930 Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args);
1931 }
1932 return true;
1933
1934 case OR_Deleted: {
1935 if (Diagnose) {
1936 Diag(StartLoc, diag::err_ovl_deleted_call)
1937 << Best->Function->isDeleted()
1938 << Name
1939 << getDeletedOrUnavailableSuffix(Best->Function)
1940 << Range;
1941 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args);
1942 }
1943 return true;
1944 }
1945 }
1946 llvm_unreachable("Unreachable, bad result from BestViableFunction");
1947 }
1948
1949
1950 /// DeclareGlobalNewDelete - Declare the global forms of operator new and
1951 /// delete. These are:
1952 /// @code
1953 /// // C++03:
1954 /// void* operator new(std::size_t) throw(std::bad_alloc);
1955 /// void* operator new[](std::size_t) throw(std::bad_alloc);
1956 /// void operator delete(void *) throw();
1957 /// void operator delete[](void *) throw();
1958 /// // C++11:
1959 /// void* operator new(std::size_t);
1960 /// void* operator new[](std::size_t);
1961 /// void operator delete(void *) noexcept;
1962 /// void operator delete[](void *) noexcept;
1963 /// // C++1y:
1964 /// void* operator new(std::size_t);
1965 /// void* operator new[](std::size_t);
1966 /// void operator delete(void *) noexcept;
1967 /// void operator delete[](void *) noexcept;
1968 /// void operator delete(void *, std::size_t) noexcept;
1969 /// void operator delete[](void *, std::size_t) noexcept;
1970 /// @endcode
1971 /// Note that the placement and nothrow forms of new are *not* implicitly
1972 /// declared. Their use requires including \<new\>.
DeclareGlobalNewDelete()1973 void Sema::DeclareGlobalNewDelete() {
1974 if (GlobalNewDeleteDeclared)
1975 return;
1976
1977 // C++ [basic.std.dynamic]p2:
1978 // [...] The following allocation and deallocation functions (18.4) are
1979 // implicitly declared in global scope in each translation unit of a
1980 // program
1981 //
1982 // C++03:
1983 // void* operator new(std::size_t) throw(std::bad_alloc);
1984 // void* operator new[](std::size_t) throw(std::bad_alloc);
1985 // void operator delete(void*) throw();
1986 // void operator delete[](void*) throw();
1987 // C++11:
1988 // void* operator new(std::size_t);
1989 // void* operator new[](std::size_t);
1990 // void operator delete(void*) noexcept;
1991 // void operator delete[](void*) noexcept;
1992 // C++1y:
1993 // void* operator new(std::size_t);
1994 // void* operator new[](std::size_t);
1995 // void operator delete(void*) noexcept;
1996 // void operator delete[](void*) noexcept;
1997 // void operator delete(void*, std::size_t) noexcept;
1998 // void operator delete[](void*, std::size_t) noexcept;
1999 //
2000 // These implicit declarations introduce only the function names operator
2001 // new, operator new[], operator delete, operator delete[].
2002 //
2003 // Here, we need to refer to std::bad_alloc, so we will implicitly declare
2004 // "std" or "bad_alloc" as necessary to form the exception specification.
2005 // However, we do not make these implicit declarations visible to name
2006 // lookup.
2007 if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
2008 // The "std::bad_alloc" class has not yet been declared, so build it
2009 // implicitly.
2010 StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class,
2011 getOrCreateStdNamespace(),
2012 SourceLocation(), SourceLocation(),
2013 &PP.getIdentifierTable().get("bad_alloc"),
2014 nullptr);
2015 getStdBadAlloc()->setImplicit(true);
2016 }
2017
2018 GlobalNewDeleteDeclared = true;
2019
2020 QualType VoidPtr = Context.getPointerType(Context.VoidTy);
2021 QualType SizeT = Context.getSizeType();
2022 bool AssumeSaneOperatorNew = getLangOpts().AssumeSaneOperatorNew;
2023
2024 DeclareGlobalAllocationFunction(
2025 Context.DeclarationNames.getCXXOperatorName(OO_New),
2026 VoidPtr, SizeT, QualType(), AssumeSaneOperatorNew);
2027 DeclareGlobalAllocationFunction(
2028 Context.DeclarationNames.getCXXOperatorName(OO_Array_New),
2029 VoidPtr, SizeT, QualType(), AssumeSaneOperatorNew);
2030 DeclareGlobalAllocationFunction(
2031 Context.DeclarationNames.getCXXOperatorName(OO_Delete),
2032 Context.VoidTy, VoidPtr);
2033 DeclareGlobalAllocationFunction(
2034 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
2035 Context.VoidTy, VoidPtr);
2036 if (getLangOpts().SizedDeallocation) {
2037 DeclareGlobalAllocationFunction(
2038 Context.DeclarationNames.getCXXOperatorName(OO_Delete),
2039 Context.VoidTy, VoidPtr, Context.getSizeType());
2040 DeclareGlobalAllocationFunction(
2041 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
2042 Context.VoidTy, VoidPtr, Context.getSizeType());
2043 }
2044 }
2045
2046 /// DeclareGlobalAllocationFunction - Declares a single implicit global
2047 /// allocation function if it doesn't already exist.
DeclareGlobalAllocationFunction(DeclarationName Name,QualType Return,QualType Param1,QualType Param2,bool AddMallocAttr)2048 void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
2049 QualType Return,
2050 QualType Param1, QualType Param2,
2051 bool AddMallocAttr) {
2052 DeclContext *GlobalCtx = Context.getTranslationUnitDecl();
2053 unsigned NumParams = Param2.isNull() ? 1 : 2;
2054
2055 // Check if this function is already declared.
2056 DeclContext::lookup_result R = GlobalCtx->lookup(Name);
2057 for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
2058 Alloc != AllocEnd; ++Alloc) {
2059 // Only look at non-template functions, as it is the predefined,
2060 // non-templated allocation function we are trying to declare here.
2061 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
2062 if (Func->getNumParams() == NumParams) {
2063 QualType InitialParam1Type =
2064 Context.getCanonicalType(Func->getParamDecl(0)
2065 ->getType().getUnqualifiedType());
2066 QualType InitialParam2Type =
2067 NumParams == 2
2068 ? Context.getCanonicalType(Func->getParamDecl(1)
2069 ->getType().getUnqualifiedType())
2070 : QualType();
2071 // FIXME: Do we need to check for default arguments here?
2072 if (InitialParam1Type == Param1 &&
2073 (NumParams == 1 || InitialParam2Type == Param2)) {
2074 if (AddMallocAttr && !Func->hasAttr<MallocAttr>())
2075 Func->addAttr(MallocAttr::CreateImplicit(Context));
2076 // Make the function visible to name lookup, even if we found it in
2077 // an unimported module. It either is an implicitly-declared global
2078 // allocation function, or is suppressing that function.
2079 Func->setHidden(false);
2080 return;
2081 }
2082 }
2083 }
2084 }
2085
2086 FunctionProtoType::ExtProtoInfo EPI;
2087
2088 QualType BadAllocType;
2089 bool HasBadAllocExceptionSpec
2090 = (Name.getCXXOverloadedOperator() == OO_New ||
2091 Name.getCXXOverloadedOperator() == OO_Array_New);
2092 if (HasBadAllocExceptionSpec) {
2093 if (!getLangOpts().CPlusPlus11) {
2094 BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
2095 assert(StdBadAlloc && "Must have std::bad_alloc declared");
2096 EPI.ExceptionSpec.Type = EST_Dynamic;
2097 EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
2098 }
2099 } else {
2100 EPI.ExceptionSpec =
2101 getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
2102 }
2103
2104 QualType Params[] = { Param1, Param2 };
2105
2106 QualType FnType = Context.getFunctionType(
2107 Return, llvm::makeArrayRef(Params, NumParams), EPI);
2108 FunctionDecl *Alloc =
2109 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(),
2110 SourceLocation(), Name,
2111 FnType, /*TInfo=*/nullptr, SC_None, false, true);
2112 Alloc->setImplicit();
2113
2114 if (AddMallocAttr)
2115 Alloc->addAttr(MallocAttr::CreateImplicit(Context));
2116
2117 ParmVarDecl *ParamDecls[2];
2118 for (unsigned I = 0; I != NumParams; ++I) {
2119 ParamDecls[I] = ParmVarDecl::Create(Context, Alloc, SourceLocation(),
2120 SourceLocation(), nullptr,
2121 Params[I], /*TInfo=*/nullptr,
2122 SC_None, nullptr);
2123 ParamDecls[I]->setImplicit();
2124 }
2125 Alloc->setParams(llvm::makeArrayRef(ParamDecls, NumParams));
2126
2127 Context.getTranslationUnitDecl()->addDecl(Alloc);
2128 IdResolver.tryAddTopLevelDecl(Alloc, Name);
2129 }
2130
FindUsualDeallocationFunction(SourceLocation StartLoc,bool CanProvideSize,DeclarationName Name)2131 FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc,
2132 bool CanProvideSize,
2133 DeclarationName Name) {
2134 DeclareGlobalNewDelete();
2135
2136 LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
2137 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
2138
2139 // C++ [expr.new]p20:
2140 // [...] Any non-placement deallocation function matches a
2141 // non-placement allocation function. [...]
2142 llvm::SmallVector<FunctionDecl*, 2> Matches;
2143 for (LookupResult::iterator D = FoundDelete.begin(),
2144 DEnd = FoundDelete.end();
2145 D != DEnd; ++D) {
2146 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*D))
2147 if (isNonPlacementDeallocationFunction(*this, Fn))
2148 Matches.push_back(Fn);
2149 }
2150
2151 // C++1y [expr.delete]p?:
2152 // If the type is complete and deallocation function lookup finds both a
2153 // usual deallocation function with only a pointer parameter and a usual
2154 // deallocation function with both a pointer parameter and a size
2155 // parameter, then the selected deallocation function shall be the one
2156 // with two parameters. Otherwise, the selected deallocation function
2157 // shall be the function with one parameter.
2158 if (getLangOpts().SizedDeallocation && Matches.size() == 2) {
2159 unsigned NumArgs = CanProvideSize ? 2 : 1;
2160 if (Matches[0]->getNumParams() != NumArgs)
2161 Matches.erase(Matches.begin());
2162 else
2163 Matches.erase(Matches.begin() + 1);
2164 assert(Matches[0]->getNumParams() == NumArgs &&
2165 "found an unexpected usual deallocation function");
2166 }
2167
2168 assert(Matches.size() == 1 &&
2169 "unexpectedly have multiple usual deallocation functions");
2170 return Matches.front();
2171 }
2172
FindDeallocationFunction(SourceLocation StartLoc,CXXRecordDecl * RD,DeclarationName Name,FunctionDecl * & Operator,bool Diagnose)2173 bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
2174 DeclarationName Name,
2175 FunctionDecl* &Operator, bool Diagnose) {
2176 LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
2177 // Try to find operator delete/operator delete[] in class scope.
2178 LookupQualifiedName(Found, RD);
2179
2180 if (Found.isAmbiguous())
2181 return true;
2182
2183 Found.suppressDiagnostics();
2184
2185 SmallVector<DeclAccessPair,4> Matches;
2186 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
2187 F != FEnd; ++F) {
2188 NamedDecl *ND = (*F)->getUnderlyingDecl();
2189
2190 // Ignore template operator delete members from the check for a usual
2191 // deallocation function.
2192 if (isa<FunctionTemplateDecl>(ND))
2193 continue;
2194
2195 if (cast<CXXMethodDecl>(ND)->isUsualDeallocationFunction())
2196 Matches.push_back(F.getPair());
2197 }
2198
2199 // There's exactly one suitable operator; pick it.
2200 if (Matches.size() == 1) {
2201 Operator = cast<CXXMethodDecl>(Matches[0]->getUnderlyingDecl());
2202
2203 if (Operator->isDeleted()) {
2204 if (Diagnose) {
2205 Diag(StartLoc, diag::err_deleted_function_use);
2206 NoteDeletedFunction(Operator);
2207 }
2208 return true;
2209 }
2210
2211 if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
2212 Matches[0], Diagnose) == AR_inaccessible)
2213 return true;
2214
2215 return false;
2216
2217 // We found multiple suitable operators; complain about the ambiguity.
2218 } else if (!Matches.empty()) {
2219 if (Diagnose) {
2220 Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
2221 << Name << RD;
2222
2223 for (SmallVectorImpl<DeclAccessPair>::iterator
2224 F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F)
2225 Diag((*F)->getUnderlyingDecl()->getLocation(),
2226 diag::note_member_declared_here) << Name;
2227 }
2228 return true;
2229 }
2230
2231 // We did find operator delete/operator delete[] declarations, but
2232 // none of them were suitable.
2233 if (!Found.empty()) {
2234 if (Diagnose) {
2235 Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
2236 << Name << RD;
2237
2238 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
2239 F != FEnd; ++F)
2240 Diag((*F)->getUnderlyingDecl()->getLocation(),
2241 diag::note_member_declared_here) << Name;
2242 }
2243 return true;
2244 }
2245
2246 Operator = nullptr;
2247 return false;
2248 }
2249
2250 /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
2251 /// @code ::delete ptr; @endcode
2252 /// or
2253 /// @code delete [] ptr; @endcode
2254 ExprResult
ActOnCXXDelete(SourceLocation StartLoc,bool UseGlobal,bool ArrayForm,Expr * ExE)2255 Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
2256 bool ArrayForm, Expr *ExE) {
2257 // C++ [expr.delete]p1:
2258 // The operand shall have a pointer type, or a class type having a single
2259 // non-explicit conversion function to a pointer type. The result has type
2260 // void.
2261 //
2262 // DR599 amends "pointer type" to "pointer to object type" in both cases.
2263
2264 ExprResult Ex = ExE;
2265 FunctionDecl *OperatorDelete = nullptr;
2266 bool ArrayFormAsWritten = ArrayForm;
2267 bool UsualArrayDeleteWantsSize = false;
2268
2269 if (!Ex.get()->isTypeDependent()) {
2270 // Perform lvalue-to-rvalue cast, if needed.
2271 Ex = DefaultLvalueConversion(Ex.get());
2272 if (Ex.isInvalid())
2273 return ExprError();
2274
2275 QualType Type = Ex.get()->getType();
2276
2277 class DeleteConverter : public ContextualImplicitConverter {
2278 public:
2279 DeleteConverter() : ContextualImplicitConverter(false, true) {}
2280
2281 bool match(QualType ConvType) override {
2282 // FIXME: If we have an operator T* and an operator void*, we must pick
2283 // the operator T*.
2284 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
2285 if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
2286 return true;
2287 return false;
2288 }
2289
2290 SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
2291 QualType T) override {
2292 return S.Diag(Loc, diag::err_delete_operand) << T;
2293 }
2294
2295 SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
2296 QualType T) override {
2297 return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
2298 }
2299
2300 SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
2301 QualType T,
2302 QualType ConvTy) override {
2303 return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
2304 }
2305
2306 SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
2307 QualType ConvTy) override {
2308 return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
2309 << ConvTy;
2310 }
2311
2312 SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
2313 QualType T) override {
2314 return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
2315 }
2316
2317 SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
2318 QualType ConvTy) override {
2319 return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
2320 << ConvTy;
2321 }
2322
2323 SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
2324 QualType T,
2325 QualType ConvTy) override {
2326 llvm_unreachable("conversion functions are permitted");
2327 }
2328 } Converter;
2329
2330 Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
2331 if (Ex.isInvalid())
2332 return ExprError();
2333 Type = Ex.get()->getType();
2334 if (!Converter.match(Type))
2335 // FIXME: PerformContextualImplicitConversion should return ExprError
2336 // itself in this case.
2337 return ExprError();
2338
2339 QualType Pointee = Type->getAs<PointerType>()->getPointeeType();
2340 QualType PointeeElem = Context.getBaseElementType(Pointee);
2341
2342 if (unsigned AddressSpace = Pointee.getAddressSpace())
2343 return Diag(Ex.get()->getLocStart(),
2344 diag::err_address_space_qualified_delete)
2345 << Pointee.getUnqualifiedType() << AddressSpace;
2346
2347 CXXRecordDecl *PointeeRD = nullptr;
2348 if (Pointee->isVoidType() && !isSFINAEContext()) {
2349 // The C++ standard bans deleting a pointer to a non-object type, which
2350 // effectively bans deletion of "void*". However, most compilers support
2351 // this, so we treat it as a warning unless we're in a SFINAE context.
2352 Diag(StartLoc, diag::ext_delete_void_ptr_operand)
2353 << Type << Ex.get()->getSourceRange();
2354 } else if (Pointee->isFunctionType() || Pointee->isVoidType()) {
2355 return ExprError(Diag(StartLoc, diag::err_delete_operand)
2356 << Type << Ex.get()->getSourceRange());
2357 } else if (!Pointee->isDependentType()) {
2358 if (!RequireCompleteType(StartLoc, Pointee,
2359 diag::warn_delete_incomplete, Ex.get())) {
2360 if (const RecordType *RT = PointeeElem->getAs<RecordType>())
2361 PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
2362 }
2363 }
2364
2365 // C++ [expr.delete]p2:
2366 // [Note: a pointer to a const type can be the operand of a
2367 // delete-expression; it is not necessary to cast away the constness
2368 // (5.2.11) of the pointer expression before it is used as the operand
2369 // of the delete-expression. ]
2370
2371 if (Pointee->isArrayType() && !ArrayForm) {
2372 Diag(StartLoc, diag::warn_delete_array_type)
2373 << Type << Ex.get()->getSourceRange()
2374 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(StartLoc), "[]");
2375 ArrayForm = true;
2376 }
2377
2378 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
2379 ArrayForm ? OO_Array_Delete : OO_Delete);
2380
2381 if (PointeeRD) {
2382 if (!UseGlobal &&
2383 FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
2384 OperatorDelete))
2385 return ExprError();
2386
2387 // If we're allocating an array of records, check whether the
2388 // usual operator delete[] has a size_t parameter.
2389 if (ArrayForm) {
2390 // If the user specifically asked to use the global allocator,
2391 // we'll need to do the lookup into the class.
2392 if (UseGlobal)
2393 UsualArrayDeleteWantsSize =
2394 doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);
2395
2396 // Otherwise, the usual operator delete[] should be the
2397 // function we just found.
2398 else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
2399 UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2);
2400 }
2401
2402 if (!PointeeRD->hasIrrelevantDestructor())
2403 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
2404 MarkFunctionReferenced(StartLoc,
2405 const_cast<CXXDestructorDecl*>(Dtor));
2406 if (DiagnoseUseOfDecl(Dtor, StartLoc))
2407 return ExprError();
2408 }
2409
2410 // C++ [expr.delete]p3:
2411 // In the first alternative (delete object), if the static type of the
2412 // object to be deleted is different from its dynamic type, the static
2413 // type shall be a base class of the dynamic type of the object to be
2414 // deleted and the static type shall have a virtual destructor or the
2415 // behavior is undefined.
2416 //
2417 // Note: a final class cannot be derived from, no issue there
2418 if (PointeeRD->isPolymorphic() && !PointeeRD->hasAttr<FinalAttr>()) {
2419 CXXDestructorDecl *dtor = PointeeRD->getDestructor();
2420 if (dtor && !dtor->isVirtual()) {
2421 if (PointeeRD->isAbstract()) {
2422 // If the class is abstract, we warn by default, because we're
2423 // sure the code has undefined behavior.
2424 Diag(StartLoc, diag::warn_delete_abstract_non_virtual_dtor)
2425 << PointeeElem;
2426 } else if (!ArrayForm) {
2427 // Otherwise, if this is not an array delete, it's a bit suspect,
2428 // but not necessarily wrong.
2429 Diag(StartLoc, diag::warn_delete_non_virtual_dtor) << PointeeElem;
2430 }
2431 }
2432 }
2433
2434 }
2435
2436 if (!OperatorDelete)
2437 // Look for a global declaration.
2438 OperatorDelete = FindUsualDeallocationFunction(
2439 StartLoc, !RequireCompleteType(StartLoc, Pointee, 0) &&
2440 (!ArrayForm || UsualArrayDeleteWantsSize ||
2441 Pointee.isDestructedType()),
2442 DeleteName);
2443
2444 MarkFunctionReferenced(StartLoc, OperatorDelete);
2445
2446 // Check access and ambiguity of operator delete and destructor.
2447 if (PointeeRD) {
2448 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
2449 CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
2450 PDiag(diag::err_access_dtor) << PointeeElem);
2451 }
2452 }
2453 }
2454
2455 return new (Context) CXXDeleteExpr(
2456 Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
2457 UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
2458 }
2459
2460 /// \brief Check the use of the given variable as a C++ condition in an if,
2461 /// while, do-while, or switch statement.
CheckConditionVariable(VarDecl * ConditionVar,SourceLocation StmtLoc,bool ConvertToBoolean)2462 ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar,
2463 SourceLocation StmtLoc,
2464 bool ConvertToBoolean) {
2465 if (ConditionVar->isInvalidDecl())
2466 return ExprError();
2467
2468 QualType T = ConditionVar->getType();
2469
2470 // C++ [stmt.select]p2:
2471 // The declarator shall not specify a function or an array.
2472 if (T->isFunctionType())
2473 return ExprError(Diag(ConditionVar->getLocation(),
2474 diag::err_invalid_use_of_function_type)
2475 << ConditionVar->getSourceRange());
2476 else if (T->isArrayType())
2477 return ExprError(Diag(ConditionVar->getLocation(),
2478 diag::err_invalid_use_of_array_type)
2479 << ConditionVar->getSourceRange());
2480
2481 ExprResult Condition = DeclRefExpr::Create(
2482 Context, NestedNameSpecifierLoc(), SourceLocation(), ConditionVar,
2483 /*enclosing*/ false, ConditionVar->getLocation(),
2484 ConditionVar->getType().getNonReferenceType(), VK_LValue);
2485
2486 MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get()));
2487
2488 if (ConvertToBoolean) {
2489 Condition = CheckBooleanCondition(Condition.get(), StmtLoc);
2490 if (Condition.isInvalid())
2491 return ExprError();
2492 }
2493
2494 return Condition;
2495 }
2496
2497 /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
CheckCXXBooleanCondition(Expr * CondExpr)2498 ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr) {
2499 // C++ 6.4p4:
2500 // The value of a condition that is an initialized declaration in a statement
2501 // other than a switch statement is the value of the declared variable
2502 // implicitly converted to type bool. If that conversion is ill-formed, the
2503 // program is ill-formed.
2504 // The value of a condition that is an expression is the value of the
2505 // expression, implicitly converted to bool.
2506 //
2507 return PerformContextuallyConvertToBool(CondExpr);
2508 }
2509
2510 /// Helper function to determine whether this is the (deprecated) C++
2511 /// conversion from a string literal to a pointer to non-const char or
2512 /// non-const wchar_t (for narrow and wide string literals,
2513 /// respectively).
2514 bool
IsStringLiteralToNonConstPointerConversion(Expr * From,QualType ToType)2515 Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
2516 // Look inside the implicit cast, if it exists.
2517 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
2518 From = Cast->getSubExpr();
2519
2520 // A string literal (2.13.4) that is not a wide string literal can
2521 // be converted to an rvalue of type "pointer to char"; a wide
2522 // string literal can be converted to an rvalue of type "pointer
2523 // to wchar_t" (C++ 4.2p2).
2524 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
2525 if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
2526 if (const BuiltinType *ToPointeeType
2527 = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
2528 // This conversion is considered only when there is an
2529 // explicit appropriate pointer target type (C++ 4.2p2).
2530 if (!ToPtrType->getPointeeType().hasQualifiers()) {
2531 switch (StrLit->getKind()) {
2532 case StringLiteral::UTF8:
2533 case StringLiteral::UTF16:
2534 case StringLiteral::UTF32:
2535 // We don't allow UTF literals to be implicitly converted
2536 break;
2537 case StringLiteral::Ascii:
2538 return (ToPointeeType->getKind() == BuiltinType::Char_U ||
2539 ToPointeeType->getKind() == BuiltinType::Char_S);
2540 case StringLiteral::Wide:
2541 return ToPointeeType->isWideCharType();
2542 }
2543 }
2544 }
2545
2546 return false;
2547 }
2548
BuildCXXCastArgument(Sema & S,SourceLocation CastLoc,QualType Ty,CastKind Kind,CXXMethodDecl * Method,DeclAccessPair FoundDecl,bool HadMultipleCandidates,Expr * From)2549 static ExprResult BuildCXXCastArgument(Sema &S,
2550 SourceLocation CastLoc,
2551 QualType Ty,
2552 CastKind Kind,
2553 CXXMethodDecl *Method,
2554 DeclAccessPair FoundDecl,
2555 bool HadMultipleCandidates,
2556 Expr *From) {
2557 switch (Kind) {
2558 default: llvm_unreachable("Unhandled cast kind!");
2559 case CK_ConstructorConversion: {
2560 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
2561 SmallVector<Expr*, 8> ConstructorArgs;
2562
2563 if (S.RequireNonAbstractType(CastLoc, Ty,
2564 diag::err_allocation_of_abstract_type))
2565 return ExprError();
2566
2567 if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs))
2568 return ExprError();
2569
2570 S.CheckConstructorAccess(CastLoc, Constructor,
2571 InitializedEntity::InitializeTemporary(Ty),
2572 Constructor->getAccess());
2573
2574 ExprResult Result = S.BuildCXXConstructExpr(
2575 CastLoc, Ty, cast<CXXConstructorDecl>(Method),
2576 ConstructorArgs, HadMultipleCandidates,
2577 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
2578 CXXConstructExpr::CK_Complete, SourceRange());
2579 if (Result.isInvalid())
2580 return ExprError();
2581
2582 return S.MaybeBindToTemporary(Result.getAs<Expr>());
2583 }
2584
2585 case CK_UserDefinedConversion: {
2586 assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");
2587
2588 // Create an implicit call expr that calls it.
2589 CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
2590 ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
2591 HadMultipleCandidates);
2592 if (Result.isInvalid())
2593 return ExprError();
2594 // Record usage of conversion in an implicit cast.
2595 Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
2596 CK_UserDefinedConversion, Result.get(),
2597 nullptr, Result.get()->getValueKind());
2598
2599 S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
2600
2601 return S.MaybeBindToTemporary(Result.get());
2602 }
2603 }
2604 }
2605
2606 /// PerformImplicitConversion - Perform an implicit conversion of the
2607 /// expression From to the type ToType using the pre-computed implicit
2608 /// conversion sequence ICS. Returns the converted
2609 /// expression. Action is the kind of conversion we're performing,
2610 /// used in the error message.
2611 ExprResult
PerformImplicitConversion(Expr * From,QualType ToType,const ImplicitConversionSequence & ICS,AssignmentAction Action,CheckedConversionKind CCK)2612 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
2613 const ImplicitConversionSequence &ICS,
2614 AssignmentAction Action,
2615 CheckedConversionKind CCK) {
2616 switch (ICS.getKind()) {
2617 case ImplicitConversionSequence::StandardConversion: {
2618 ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
2619 Action, CCK);
2620 if (Res.isInvalid())
2621 return ExprError();
2622 From = Res.get();
2623 break;
2624 }
2625
2626 case ImplicitConversionSequence::UserDefinedConversion: {
2627
2628 FunctionDecl *FD = ICS.UserDefined.ConversionFunction;
2629 CastKind CastKind;
2630 QualType BeforeToType;
2631 assert(FD && "FIXME: aggregate initialization from init list");
2632 if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
2633 CastKind = CK_UserDefinedConversion;
2634
2635 // If the user-defined conversion is specified by a conversion function,
2636 // the initial standard conversion sequence converts the source type to
2637 // the implicit object parameter of the conversion function.
2638 BeforeToType = Context.getTagDeclType(Conv->getParent());
2639 } else {
2640 const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
2641 CastKind = CK_ConstructorConversion;
2642 // Do no conversion if dealing with ... for the first conversion.
2643 if (!ICS.UserDefined.EllipsisConversion) {
2644 // If the user-defined conversion is specified by a constructor, the
2645 // initial standard conversion sequence converts the source type to
2646 // the type required by the argument of the constructor
2647 BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
2648 }
2649 }
2650 // Watch out for ellipsis conversion.
2651 if (!ICS.UserDefined.EllipsisConversion) {
2652 ExprResult Res =
2653 PerformImplicitConversion(From, BeforeToType,
2654 ICS.UserDefined.Before, AA_Converting,
2655 CCK);
2656 if (Res.isInvalid())
2657 return ExprError();
2658 From = Res.get();
2659 }
2660
2661 ExprResult CastArg
2662 = BuildCXXCastArgument(*this,
2663 From->getLocStart(),
2664 ToType.getNonReferenceType(),
2665 CastKind, cast<CXXMethodDecl>(FD),
2666 ICS.UserDefined.FoundConversionFunction,
2667 ICS.UserDefined.HadMultipleCandidates,
2668 From);
2669
2670 if (CastArg.isInvalid())
2671 return ExprError();
2672
2673 From = CastArg.get();
2674
2675 return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
2676 AA_Converting, CCK);
2677 }
2678
2679 case ImplicitConversionSequence::AmbiguousConversion:
2680 ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
2681 PDiag(diag::err_typecheck_ambiguous_condition)
2682 << From->getSourceRange());
2683 return ExprError();
2684
2685 case ImplicitConversionSequence::EllipsisConversion:
2686 llvm_unreachable("Cannot perform an ellipsis conversion");
2687
2688 case ImplicitConversionSequence::BadConversion:
2689 return ExprError();
2690 }
2691
2692 // Everything went well.
2693 return From;
2694 }
2695
2696 /// PerformImplicitConversion - Perform an implicit conversion of the
2697 /// expression From to the type ToType by following the standard
2698 /// conversion sequence SCS. Returns the converted
2699 /// expression. Flavor is the context in which we're performing this
2700 /// conversion, for use in error messages.
2701 ExprResult
PerformImplicitConversion(Expr * From,QualType ToType,const StandardConversionSequence & SCS,AssignmentAction Action,CheckedConversionKind CCK)2702 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
2703 const StandardConversionSequence& SCS,
2704 AssignmentAction Action,
2705 CheckedConversionKind CCK) {
2706 bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);
2707
2708 // Overall FIXME: we are recomputing too many types here and doing far too
2709 // much extra work. What this means is that we need to keep track of more
2710 // information that is computed when we try the implicit conversion initially,
2711 // so that we don't need to recompute anything here.
2712 QualType FromType = From->getType();
2713
2714 if (SCS.CopyConstructor) {
2715 // FIXME: When can ToType be a reference type?
2716 assert(!ToType->isReferenceType());
2717 if (SCS.Second == ICK_Derived_To_Base) {
2718 SmallVector<Expr*, 8> ConstructorArgs;
2719 if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor),
2720 From, /*FIXME:ConstructLoc*/SourceLocation(),
2721 ConstructorArgs))
2722 return ExprError();
2723 return BuildCXXConstructExpr(
2724 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor,
2725 ConstructorArgs, /*HadMultipleCandidates*/ false,
2726 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
2727 CXXConstructExpr::CK_Complete, SourceRange());
2728 }
2729 return BuildCXXConstructExpr(
2730 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor,
2731 From, /*HadMultipleCandidates*/ false,
2732 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
2733 CXXConstructExpr::CK_Complete, SourceRange());
2734 }
2735
2736 // Resolve overloaded function references.
2737 if (Context.hasSameType(FromType, Context.OverloadTy)) {
2738 DeclAccessPair Found;
2739 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType,
2740 true, Found);
2741 if (!Fn)
2742 return ExprError();
2743
2744 if (DiagnoseUseOfDecl(Fn, From->getLocStart()))
2745 return ExprError();
2746
2747 From = FixOverloadedFunctionReference(From, Found, Fn);
2748 FromType = From->getType();
2749 }
2750
2751 // If we're converting to an atomic type, first convert to the corresponding
2752 // non-atomic type.
2753 QualType ToAtomicType;
2754 if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
2755 ToAtomicType = ToType;
2756 ToType = ToAtomic->getValueType();
2757 }
2758
2759 // Perform the first implicit conversion.
2760 switch (SCS.First) {
2761 case ICK_Identity:
2762 if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
2763 FromType = FromAtomic->getValueType().getUnqualifiedType();
2764 From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
2765 From, /*BasePath=*/nullptr, VK_RValue);
2766 }
2767 break;
2768
2769 case ICK_Lvalue_To_Rvalue: {
2770 assert(From->getObjectKind() != OK_ObjCProperty);
2771 ExprResult FromRes = DefaultLvalueConversion(From);
2772 assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!");
2773 From = FromRes.get();
2774 FromType = From->getType();
2775 break;
2776 }
2777
2778 case ICK_Array_To_Pointer:
2779 FromType = Context.getArrayDecayedType(FromType);
2780 From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay,
2781 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2782 break;
2783
2784 case ICK_Function_To_Pointer:
2785 FromType = Context.getPointerType(FromType);
2786 From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
2787 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2788 break;
2789
2790 default:
2791 llvm_unreachable("Improper first standard conversion");
2792 }
2793
2794 // Perform the second implicit conversion
2795 switch (SCS.Second) {
2796 case ICK_Identity:
2797 // C++ [except.spec]p5:
2798 // [For] assignment to and initialization of pointers to functions,
2799 // pointers to member functions, and references to functions: the
2800 // target entity shall allow at least the exceptions allowed by the
2801 // source value in the assignment or initialization.
2802 switch (Action) {
2803 case AA_Assigning:
2804 case AA_Initializing:
2805 // Note, function argument passing and returning are initialization.
2806 case AA_Passing:
2807 case AA_Returning:
2808 case AA_Sending:
2809 case AA_Passing_CFAudited:
2810 if (CheckExceptionSpecCompatibility(From, ToType))
2811 return ExprError();
2812 break;
2813
2814 case AA_Casting:
2815 case AA_Converting:
2816 // Casts and implicit conversions are not initialization, so are not
2817 // checked for exception specification mismatches.
2818 break;
2819 }
2820 // Nothing else to do.
2821 break;
2822
2823 case ICK_NoReturn_Adjustment:
2824 // If both sides are functions (or pointers/references to them), there could
2825 // be incompatible exception declarations.
2826 if (CheckExceptionSpecCompatibility(From, ToType))
2827 return ExprError();
2828
2829 From = ImpCastExprToType(From, ToType, CK_NoOp,
2830 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2831 break;
2832
2833 case ICK_Integral_Promotion:
2834 case ICK_Integral_Conversion:
2835 if (ToType->isBooleanType()) {
2836 assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
2837 SCS.Second == ICK_Integral_Promotion &&
2838 "only enums with fixed underlying type can promote to bool");
2839 From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean,
2840 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2841 } else {
2842 From = ImpCastExprToType(From, ToType, CK_IntegralCast,
2843 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2844 }
2845 break;
2846
2847 case ICK_Floating_Promotion:
2848 case ICK_Floating_Conversion:
2849 From = ImpCastExprToType(From, ToType, CK_FloatingCast,
2850 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2851 break;
2852
2853 case ICK_Complex_Promotion:
2854 case ICK_Complex_Conversion: {
2855 QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType();
2856 QualType ToEl = ToType->getAs<ComplexType>()->getElementType();
2857 CastKind CK;
2858 if (FromEl->isRealFloatingType()) {
2859 if (ToEl->isRealFloatingType())
2860 CK = CK_FloatingComplexCast;
2861 else
2862 CK = CK_FloatingComplexToIntegralComplex;
2863 } else if (ToEl->isRealFloatingType()) {
2864 CK = CK_IntegralComplexToFloatingComplex;
2865 } else {
2866 CK = CK_IntegralComplexCast;
2867 }
2868 From = ImpCastExprToType(From, ToType, CK,
2869 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2870 break;
2871 }
2872
2873 case ICK_Floating_Integral:
2874 if (ToType->isRealFloatingType())
2875 From = ImpCastExprToType(From, ToType, CK_IntegralToFloating,
2876 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2877 else
2878 From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral,
2879 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2880 break;
2881
2882 case ICK_Compatible_Conversion:
2883 From = ImpCastExprToType(From, ToType, CK_NoOp,
2884 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2885 break;
2886
2887 case ICK_Writeback_Conversion:
2888 case ICK_Pointer_Conversion: {
2889 if (SCS.IncompatibleObjC && Action != AA_Casting) {
2890 // Diagnose incompatible Objective-C conversions
2891 if (Action == AA_Initializing || Action == AA_Assigning)
2892 Diag(From->getLocStart(),
2893 diag::ext_typecheck_convert_incompatible_pointer)
2894 << ToType << From->getType() << Action
2895 << From->getSourceRange() << 0;
2896 else
2897 Diag(From->getLocStart(),
2898 diag::ext_typecheck_convert_incompatible_pointer)
2899 << From->getType() << ToType << Action
2900 << From->getSourceRange() << 0;
2901
2902 if (From->getType()->isObjCObjectPointerType() &&
2903 ToType->isObjCObjectPointerType())
2904 EmitRelatedResultTypeNote(From);
2905 }
2906 else if (getLangOpts().ObjCAutoRefCount &&
2907 !CheckObjCARCUnavailableWeakConversion(ToType,
2908 From->getType())) {
2909 if (Action == AA_Initializing)
2910 Diag(From->getLocStart(),
2911 diag::err_arc_weak_unavailable_assign);
2912 else
2913 Diag(From->getLocStart(),
2914 diag::err_arc_convesion_of_weak_unavailable)
2915 << (Action == AA_Casting) << From->getType() << ToType
2916 << From->getSourceRange();
2917 }
2918
2919 CastKind Kind = CK_Invalid;
2920 CXXCastPath BasePath;
2921 if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle))
2922 return ExprError();
2923
2924 // Make sure we extend blocks if necessary.
2925 // FIXME: doing this here is really ugly.
2926 if (Kind == CK_BlockPointerToObjCPointerCast) {
2927 ExprResult E = From;
2928 (void) PrepareCastToObjCObjectPointer(E);
2929 From = E.get();
2930 }
2931 if (getLangOpts().ObjCAutoRefCount)
2932 CheckObjCARCConversion(SourceRange(), ToType, From, CCK);
2933 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
2934 .get();
2935 break;
2936 }
2937
2938 case ICK_Pointer_Member: {
2939 CastKind Kind = CK_Invalid;
2940 CXXCastPath BasePath;
2941 if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
2942 return ExprError();
2943 if (CheckExceptionSpecCompatibility(From, ToType))
2944 return ExprError();
2945
2946 // We may not have been able to figure out what this member pointer resolved
2947 // to up until this exact point. Attempt to lock-in it's inheritance model.
2948 QualType FromType = From->getType();
2949 if (FromType->isMemberPointerType())
2950 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
2951 RequireCompleteType(From->getExprLoc(), FromType, 0);
2952
2953 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
2954 .get();
2955 break;
2956 }
2957
2958 case ICK_Boolean_Conversion:
2959 // Perform half-to-boolean conversion via float.
2960 if (From->getType()->isHalfType()) {
2961 From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
2962 FromType = Context.FloatTy;
2963 }
2964
2965 From = ImpCastExprToType(From, Context.BoolTy,
2966 ScalarTypeToBooleanCastKind(FromType),
2967 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2968 break;
2969
2970 case ICK_Derived_To_Base: {
2971 CXXCastPath BasePath;
2972 if (CheckDerivedToBaseConversion(From->getType(),
2973 ToType.getNonReferenceType(),
2974 From->getLocStart(),
2975 From->getSourceRange(),
2976 &BasePath,
2977 CStyle))
2978 return ExprError();
2979
2980 From = ImpCastExprToType(From, ToType.getNonReferenceType(),
2981 CK_DerivedToBase, From->getValueKind(),
2982 &BasePath, CCK).get();
2983 break;
2984 }
2985
2986 case ICK_Vector_Conversion:
2987 From = ImpCastExprToType(From, ToType, CK_BitCast,
2988 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2989 break;
2990
2991 case ICK_Vector_Splat:
2992 From = ImpCastExprToType(From, ToType, CK_VectorSplat,
2993 VK_RValue, /*BasePath=*/nullptr, CCK).get();
2994 break;
2995
2996 case ICK_Complex_Real:
2997 // Case 1. x -> _Complex y
2998 if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
2999 QualType ElType = ToComplex->getElementType();
3000 bool isFloatingComplex = ElType->isRealFloatingType();
3001
3002 // x -> y
3003 if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
3004 // do nothing
3005 } else if (From->getType()->isRealFloatingType()) {
3006 From = ImpCastExprToType(From, ElType,
3007 isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
3008 } else {
3009 assert(From->getType()->isIntegerType());
3010 From = ImpCastExprToType(From, ElType,
3011 isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
3012 }
3013 // y -> _Complex y
3014 From = ImpCastExprToType(From, ToType,
3015 isFloatingComplex ? CK_FloatingRealToComplex
3016 : CK_IntegralRealToComplex).get();
3017
3018 // Case 2. _Complex x -> y
3019 } else {
3020 const ComplexType *FromComplex = From->getType()->getAs<ComplexType>();
3021 assert(FromComplex);
3022
3023 QualType ElType = FromComplex->getElementType();
3024 bool isFloatingComplex = ElType->isRealFloatingType();
3025
3026 // _Complex x -> x
3027 From = ImpCastExprToType(From, ElType,
3028 isFloatingComplex ? CK_FloatingComplexToReal
3029 : CK_IntegralComplexToReal,
3030 VK_RValue, /*BasePath=*/nullptr, CCK).get();
3031
3032 // x -> y
3033 if (Context.hasSameUnqualifiedType(ElType, ToType)) {
3034 // do nothing
3035 } else if (ToType->isRealFloatingType()) {
3036 From = ImpCastExprToType(From, ToType,
3037 isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating,
3038 VK_RValue, /*BasePath=*/nullptr, CCK).get();
3039 } else {
3040 assert(ToType->isIntegerType());
3041 From = ImpCastExprToType(From, ToType,
3042 isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast,
3043 VK_RValue, /*BasePath=*/nullptr, CCK).get();
3044 }
3045 }
3046 break;
3047
3048 case ICK_Block_Pointer_Conversion: {
3049 From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast,
3050 VK_RValue, /*BasePath=*/nullptr, CCK).get();
3051 break;
3052 }
3053
3054 case ICK_TransparentUnionConversion: {
3055 ExprResult FromRes = From;
3056 Sema::AssignConvertType ConvTy =
3057 CheckTransparentUnionArgumentConstraints(ToType, FromRes);
3058 if (FromRes.isInvalid())
3059 return ExprError();
3060 From = FromRes.get();
3061 assert ((ConvTy == Sema::Compatible) &&
3062 "Improper transparent union conversion");
3063 (void)ConvTy;
3064 break;
3065 }
3066
3067 case ICK_Zero_Event_Conversion:
3068 From = ImpCastExprToType(From, ToType,
3069 CK_ZeroToOCLEvent,
3070 From->getValueKind()).get();
3071 break;
3072
3073 case ICK_Lvalue_To_Rvalue:
3074 case ICK_Array_To_Pointer:
3075 case ICK_Function_To_Pointer:
3076 case ICK_Qualification:
3077 case ICK_Num_Conversion_Kinds:
3078 llvm_unreachable("Improper second standard conversion");
3079 }
3080
3081 switch (SCS.Third) {
3082 case ICK_Identity:
3083 // Nothing to do.
3084 break;
3085
3086 case ICK_Qualification: {
3087 // The qualification keeps the category of the inner expression, unless the
3088 // target type isn't a reference.
3089 ExprValueKind VK = ToType->isReferenceType() ?
3090 From->getValueKind() : VK_RValue;
3091 From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context),
3092 CK_NoOp, VK, /*BasePath=*/nullptr, CCK).get();
3093
3094 if (SCS.DeprecatedStringLiteralToCharPtr &&
3095 !getLangOpts().WritableStrings) {
3096 Diag(From->getLocStart(), getLangOpts().CPlusPlus11
3097 ? diag::ext_deprecated_string_literal_conversion
3098 : diag::warn_deprecated_string_literal_conversion)
3099 << ToType.getNonReferenceType();
3100 }
3101
3102 break;
3103 }
3104
3105 default:
3106 llvm_unreachable("Improper third standard conversion");
3107 }
3108
3109 // If this conversion sequence involved a scalar -> atomic conversion, perform
3110 // that conversion now.
3111 if (!ToAtomicType.isNull()) {
3112 assert(Context.hasSameType(
3113 ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()));
3114 From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic,
3115 VK_RValue, nullptr, CCK).get();
3116 }
3117
3118 return From;
3119 }
3120
3121 /// \brief Check the completeness of a type in a unary type trait.
3122 ///
3123 /// If the particular type trait requires a complete type, tries to complete
3124 /// it. If completing the type fails, a diagnostic is emitted and false
3125 /// returned. If completing the type succeeds or no completion was required,
3126 /// returns true.
CheckUnaryTypeTraitTypeCompleteness(Sema & S,TypeTrait UTT,SourceLocation Loc,QualType ArgTy)3127 static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT,
3128 SourceLocation Loc,
3129 QualType ArgTy) {
3130 // C++0x [meta.unary.prop]p3:
3131 // For all of the class templates X declared in this Clause, instantiating
3132 // that template with a template argument that is a class template
3133 // specialization may result in the implicit instantiation of the template
3134 // argument if and only if the semantics of X require that the argument
3135 // must be a complete type.
3136 // We apply this rule to all the type trait expressions used to implement
3137 // these class templates. We also try to follow any GCC documented behavior
3138 // in these expressions to ensure portability of standard libraries.
3139 switch (UTT) {
3140 default: llvm_unreachable("not a UTT");
3141 // is_complete_type somewhat obviously cannot require a complete type.
3142 case UTT_IsCompleteType:
3143 // Fall-through
3144
3145 // These traits are modeled on the type predicates in C++0x
3146 // [meta.unary.cat] and [meta.unary.comp]. They are not specified as
3147 // requiring a complete type, as whether or not they return true cannot be
3148 // impacted by the completeness of the type.
3149 case UTT_IsVoid:
3150 case UTT_IsIntegral:
3151 case UTT_IsFloatingPoint:
3152 case UTT_IsArray:
3153 case UTT_IsPointer:
3154 case UTT_IsLvalueReference:
3155 case UTT_IsRvalueReference:
3156 case UTT_IsMemberFunctionPointer:
3157 case UTT_IsMemberObjectPointer:
3158 case UTT_IsEnum:
3159 case UTT_IsUnion:
3160 case UTT_IsClass:
3161 case UTT_IsFunction:
3162 case UTT_IsReference:
3163 case UTT_IsArithmetic:
3164 case UTT_IsFundamental:
3165 case UTT_IsObject:
3166 case UTT_IsScalar:
3167 case UTT_IsCompound:
3168 case UTT_IsMemberPointer:
3169 // Fall-through
3170
3171 // These traits are modeled on type predicates in C++0x [meta.unary.prop]
3172 // which requires some of its traits to have the complete type. However,
3173 // the completeness of the type cannot impact these traits' semantics, and
3174 // so they don't require it. This matches the comments on these traits in
3175 // Table 49.
3176 case UTT_IsConst:
3177 case UTT_IsVolatile:
3178 case UTT_IsSigned:
3179 case UTT_IsUnsigned:
3180 return true;
3181
3182 // C++0x [meta.unary.prop] Table 49 requires the following traits to be
3183 // applied to a complete type.
3184 case UTT_IsTrivial:
3185 case UTT_IsTriviallyCopyable:
3186 case UTT_IsStandardLayout:
3187 case UTT_IsPOD:
3188 case UTT_IsLiteral:
3189 case UTT_IsEmpty:
3190 case UTT_IsPolymorphic:
3191 case UTT_IsAbstract:
3192 case UTT_IsInterfaceClass:
3193 case UTT_IsDestructible:
3194 case UTT_IsNothrowDestructible:
3195 // Fall-through
3196
3197 // These traits require a complete type.
3198 case UTT_IsFinal:
3199 case UTT_IsSealed:
3200
3201 // These trait expressions are designed to help implement predicates in
3202 // [meta.unary.prop] despite not being named the same. They are specified
3203 // by both GCC and the Embarcadero C++ compiler, and require the complete
3204 // type due to the overarching C++0x type predicates being implemented
3205 // requiring the complete type.
3206 case UTT_HasNothrowAssign:
3207 case UTT_HasNothrowMoveAssign:
3208 case UTT_HasNothrowConstructor:
3209 case UTT_HasNothrowCopy:
3210 case UTT_HasTrivialAssign:
3211 case UTT_HasTrivialMoveAssign:
3212 case UTT_HasTrivialDefaultConstructor:
3213 case UTT_HasTrivialMoveConstructor:
3214 case UTT_HasTrivialCopy:
3215 case UTT_HasTrivialDestructor:
3216 case UTT_HasVirtualDestructor:
3217 // Arrays of unknown bound are expressly allowed.
3218 QualType ElTy = ArgTy;
3219 if (ArgTy->isIncompleteArrayType())
3220 ElTy = S.Context.getAsArrayType(ArgTy)->getElementType();
3221
3222 // The void type is expressly allowed.
3223 if (ElTy->isVoidType())
3224 return true;
3225
3226 return !S.RequireCompleteType(
3227 Loc, ElTy, diag::err_incomplete_type_used_in_type_trait_expr);
3228 }
3229 }
3230
HasNoThrowOperator(const RecordType * RT,OverloadedOperatorKind Op,Sema & Self,SourceLocation KeyLoc,ASTContext & C,bool (CXXRecordDecl::* HasTrivial)()const,bool (CXXRecordDecl::* HasNonTrivial)()const,bool (CXXMethodDecl::* IsDesiredOp)()const)3231 static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op,
3232 Sema &Self, SourceLocation KeyLoc, ASTContext &C,
3233 bool (CXXRecordDecl::*HasTrivial)() const,
3234 bool (CXXRecordDecl::*HasNonTrivial)() const,
3235 bool (CXXMethodDecl::*IsDesiredOp)() const)
3236 {
3237 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
3238 if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)())
3239 return true;
3240
3241 DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op);
3242 DeclarationNameInfo NameInfo(Name, KeyLoc);
3243 LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName);
3244 if (Self.LookupQualifiedName(Res, RD)) {
3245 bool FoundOperator = false;
3246 Res.suppressDiagnostics();
3247 for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end();
3248 Op != OpEnd; ++Op) {
3249 if (isa<FunctionTemplateDecl>(*Op))
3250 continue;
3251
3252 CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op);
3253 if((Operator->*IsDesiredOp)()) {
3254 FoundOperator = true;
3255 const FunctionProtoType *CPT =
3256 Operator->getType()->getAs<FunctionProtoType>();
3257 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
3258 if (!CPT || !CPT->isNothrow(C))
3259 return false;
3260 }
3261 }
3262 return FoundOperator;
3263 }
3264 return false;
3265 }
3266
EvaluateUnaryTypeTrait(Sema & Self,TypeTrait UTT,SourceLocation KeyLoc,QualType T)3267 static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
3268 SourceLocation KeyLoc, QualType T) {
3269 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
3270
3271 ASTContext &C = Self.Context;
3272 switch(UTT) {
3273 default: llvm_unreachable("not a UTT");
3274 // Type trait expressions corresponding to the primary type category
3275 // predicates in C++0x [meta.unary.cat].
3276 case UTT_IsVoid:
3277 return T->isVoidType();
3278 case UTT_IsIntegral:
3279 return T->isIntegralType(C);
3280 case UTT_IsFloatingPoint:
3281 return T->isFloatingType();
3282 case UTT_IsArray:
3283 return T->isArrayType();
3284 case UTT_IsPointer:
3285 return T->isPointerType();
3286 case UTT_IsLvalueReference:
3287 return T->isLValueReferenceType();
3288 case UTT_IsRvalueReference:
3289 return T->isRValueReferenceType();
3290 case UTT_IsMemberFunctionPointer:
3291 return T->isMemberFunctionPointerType();
3292 case UTT_IsMemberObjectPointer:
3293 return T->isMemberDataPointerType();
3294 case UTT_IsEnum:
3295 return T->isEnumeralType();
3296 case UTT_IsUnion:
3297 return T->isUnionType();
3298 case UTT_IsClass:
3299 return T->isClassType() || T->isStructureType() || T->isInterfaceType();
3300 case UTT_IsFunction:
3301 return T->isFunctionType();
3302
3303 // Type trait expressions which correspond to the convenient composition
3304 // predicates in C++0x [meta.unary.comp].
3305 case UTT_IsReference:
3306 return T->isReferenceType();
3307 case UTT_IsArithmetic:
3308 return T->isArithmeticType() && !T->isEnumeralType();
3309 case UTT_IsFundamental:
3310 return T->isFundamentalType();
3311 case UTT_IsObject:
3312 return T->isObjectType();
3313 case UTT_IsScalar:
3314 // Note: semantic analysis depends on Objective-C lifetime types to be
3315 // considered scalar types. However, such types do not actually behave
3316 // like scalar types at run time (since they may require retain/release
3317 // operations), so we report them as non-scalar.
3318 if (T->isObjCLifetimeType()) {
3319 switch (T.getObjCLifetime()) {
3320 case Qualifiers::OCL_None:
3321 case Qualifiers::OCL_ExplicitNone:
3322 return true;
3323
3324 case Qualifiers::OCL_Strong:
3325 case Qualifiers::OCL_Weak:
3326 case Qualifiers::OCL_Autoreleasing:
3327 return false;
3328 }
3329 }
3330
3331 return T->isScalarType();
3332 case UTT_IsCompound:
3333 return T->isCompoundType();
3334 case UTT_IsMemberPointer:
3335 return T->isMemberPointerType();
3336
3337 // Type trait expressions which correspond to the type property predicates
3338 // in C++0x [meta.unary.prop].
3339 case UTT_IsConst:
3340 return T.isConstQualified();
3341 case UTT_IsVolatile:
3342 return T.isVolatileQualified();
3343 case UTT_IsTrivial:
3344 return T.isTrivialType(Self.Context);
3345 case UTT_IsTriviallyCopyable:
3346 return T.isTriviallyCopyableType(Self.Context);
3347 case UTT_IsStandardLayout:
3348 return T->isStandardLayoutType();
3349 case UTT_IsPOD:
3350 return T.isPODType(Self.Context);
3351 case UTT_IsLiteral:
3352 return T->isLiteralType(Self.Context);
3353 case UTT_IsEmpty:
3354 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3355 return !RD->isUnion() && RD->isEmpty();
3356 return false;
3357 case UTT_IsPolymorphic:
3358 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3359 return RD->isPolymorphic();
3360 return false;
3361 case UTT_IsAbstract:
3362 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3363 return RD->isAbstract();
3364 return false;
3365 case UTT_IsInterfaceClass:
3366 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3367 return RD->isInterface();
3368 return false;
3369 case UTT_IsFinal:
3370 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3371 return RD->hasAttr<FinalAttr>();
3372 return false;
3373 case UTT_IsSealed:
3374 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3375 if (FinalAttr *FA = RD->getAttr<FinalAttr>())
3376 return FA->isSpelledAsSealed();
3377 return false;
3378 case UTT_IsSigned:
3379 return T->isSignedIntegerType();
3380 case UTT_IsUnsigned:
3381 return T->isUnsignedIntegerType();
3382
3383 // Type trait expressions which query classes regarding their construction,
3384 // destruction, and copying. Rather than being based directly on the
3385 // related type predicates in the standard, they are specified by both
3386 // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those
3387 // specifications.
3388 //
3389 // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html
3390 // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
3391 //
3392 // Note that these builtins do not behave as documented in g++: if a class
3393 // has both a trivial and a non-trivial special member of a particular kind,
3394 // they return false! For now, we emulate this behavior.
3395 // FIXME: This appears to be a g++ bug: more complex cases reveal that it
3396 // does not correctly compute triviality in the presence of multiple special
3397 // members of the same kind. Revisit this once the g++ bug is fixed.
3398 case UTT_HasTrivialDefaultConstructor:
3399 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
3400 // If __is_pod (type) is true then the trait is true, else if type is
3401 // a cv class or union type (or array thereof) with a trivial default
3402 // constructor ([class.ctor]) then the trait is true, else it is false.
3403 if (T.isPODType(Self.Context))
3404 return true;
3405 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
3406 return RD->hasTrivialDefaultConstructor() &&
3407 !RD->hasNonTrivialDefaultConstructor();
3408 return false;
3409 case UTT_HasTrivialMoveConstructor:
3410 // This trait is implemented by MSVC 2012 and needed to parse the
3411 // standard library headers. Specifically this is used as the logic
3412 // behind std::is_trivially_move_constructible (20.9.4.3).
3413 if (T.isPODType(Self.Context))
3414 return true;
3415 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
3416 return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor();
3417 return false;
3418 case UTT_HasTrivialCopy:
3419 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
3420 // If __is_pod (type) is true or type is a reference type then
3421 // the trait is true, else if type is a cv class or union type
3422 // with a trivial copy constructor ([class.copy]) then the trait
3423 // is true, else it is false.
3424 if (T.isPODType(Self.Context) || T->isReferenceType())
3425 return true;
3426 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3427 return RD->hasTrivialCopyConstructor() &&
3428 !RD->hasNonTrivialCopyConstructor();
3429 return false;
3430 case UTT_HasTrivialMoveAssign:
3431 // This trait is implemented by MSVC 2012 and needed to parse the
3432 // standard library headers. Specifically it is used as the logic
3433 // behind std::is_trivially_move_assignable (20.9.4.3)
3434 if (T.isPODType(Self.Context))
3435 return true;
3436 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
3437 return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment();
3438 return false;
3439 case UTT_HasTrivialAssign:
3440 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
3441 // If type is const qualified or is a reference type then the
3442 // trait is false. Otherwise if __is_pod (type) is true then the
3443 // trait is true, else if type is a cv class or union type with
3444 // a trivial copy assignment ([class.copy]) then the trait is
3445 // true, else it is false.
3446 // Note: the const and reference restrictions are interesting,
3447 // given that const and reference members don't prevent a class
3448 // from having a trivial copy assignment operator (but do cause
3449 // errors if the copy assignment operator is actually used, q.v.
3450 // [class.copy]p12).
3451
3452 if (T.isConstQualified())
3453 return false;
3454 if (T.isPODType(Self.Context))
3455 return true;
3456 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3457 return RD->hasTrivialCopyAssignment() &&
3458 !RD->hasNonTrivialCopyAssignment();
3459 return false;
3460 case UTT_IsDestructible:
3461 case UTT_IsNothrowDestructible:
3462 // FIXME: Implement UTT_IsDestructible and UTT_IsNothrowDestructible.
3463 // For now, let's fall through.
3464 case UTT_HasTrivialDestructor:
3465 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
3466 // If __is_pod (type) is true or type is a reference type
3467 // then the trait is true, else if type is a cv class or union
3468 // type (or array thereof) with a trivial destructor
3469 // ([class.dtor]) then the trait is true, else it is
3470 // false.
3471 if (T.isPODType(Self.Context) || T->isReferenceType())
3472 return true;
3473
3474 // Objective-C++ ARC: autorelease types don't require destruction.
3475 if (T->isObjCLifetimeType() &&
3476 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing)
3477 return true;
3478
3479 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
3480 return RD->hasTrivialDestructor();
3481 return false;
3482 // TODO: Propagate nothrowness for implicitly declared special members.
3483 case UTT_HasNothrowAssign:
3484 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
3485 // If type is const qualified or is a reference type then the
3486 // trait is false. Otherwise if __has_trivial_assign (type)
3487 // is true then the trait is true, else if type is a cv class
3488 // or union type with copy assignment operators that are known
3489 // not to throw an exception then the trait is true, else it is
3490 // false.
3491 if (C.getBaseElementType(T).isConstQualified())
3492 return false;
3493 if (T->isReferenceType())
3494 return false;
3495 if (T.isPODType(Self.Context) || T->isObjCLifetimeType())
3496 return true;
3497
3498 if (const RecordType *RT = T->getAs<RecordType>())
3499 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
3500 &CXXRecordDecl::hasTrivialCopyAssignment,
3501 &CXXRecordDecl::hasNonTrivialCopyAssignment,
3502 &CXXMethodDecl::isCopyAssignmentOperator);
3503 return false;
3504 case UTT_HasNothrowMoveAssign:
3505 // This trait is implemented by MSVC 2012 and needed to parse the
3506 // standard library headers. Specifically this is used as the logic
3507 // behind std::is_nothrow_move_assignable (20.9.4.3).
3508 if (T.isPODType(Self.Context))
3509 return true;
3510
3511 if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>())
3512 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
3513 &CXXRecordDecl::hasTrivialMoveAssignment,
3514 &CXXRecordDecl::hasNonTrivialMoveAssignment,
3515 &CXXMethodDecl::isMoveAssignmentOperator);
3516 return false;
3517 case UTT_HasNothrowCopy:
3518 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
3519 // If __has_trivial_copy (type) is true then the trait is true, else
3520 // if type is a cv class or union type with copy constructors that are
3521 // known not to throw an exception then the trait is true, else it is
3522 // false.
3523 if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType())
3524 return true;
3525 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
3526 if (RD->hasTrivialCopyConstructor() &&
3527 !RD->hasNonTrivialCopyConstructor())
3528 return true;
3529
3530 bool FoundConstructor = false;
3531 unsigned FoundTQs;
3532 DeclContext::lookup_const_result R = Self.LookupConstructors(RD);
3533 for (DeclContext::lookup_const_iterator Con = R.begin(),
3534 ConEnd = R.end(); Con != ConEnd; ++Con) {
3535 // A template constructor is never a copy constructor.
3536 // FIXME: However, it may actually be selected at the actual overload
3537 // resolution point.
3538 if (isa<FunctionTemplateDecl>(*Con))
3539 continue;
3540 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
3541 if (Constructor->isCopyConstructor(FoundTQs)) {
3542 FoundConstructor = true;
3543 const FunctionProtoType *CPT
3544 = Constructor->getType()->getAs<FunctionProtoType>();
3545 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
3546 if (!CPT)
3547 return false;
3548 // TODO: check whether evaluating default arguments can throw.
3549 // For now, we'll be conservative and assume that they can throw.
3550 if (!CPT->isNothrow(Self.Context) || CPT->getNumParams() > 1)
3551 return false;
3552 }
3553 }
3554
3555 return FoundConstructor;
3556 }
3557 return false;
3558 case UTT_HasNothrowConstructor:
3559 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
3560 // If __has_trivial_constructor (type) is true then the trait is
3561 // true, else if type is a cv class or union type (or array
3562 // thereof) with a default constructor that is known not to
3563 // throw an exception then the trait is true, else it is false.
3564 if (T.isPODType(C) || T->isObjCLifetimeType())
3565 return true;
3566 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
3567 if (RD->hasTrivialDefaultConstructor() &&
3568 !RD->hasNonTrivialDefaultConstructor())
3569 return true;
3570
3571 bool FoundConstructor = false;
3572 DeclContext::lookup_const_result R = Self.LookupConstructors(RD);
3573 for (DeclContext::lookup_const_iterator Con = R.begin(),
3574 ConEnd = R.end(); Con != ConEnd; ++Con) {
3575 // FIXME: In C++0x, a constructor template can be a default constructor.
3576 if (isa<FunctionTemplateDecl>(*Con))
3577 continue;
3578 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
3579 if (Constructor->isDefaultConstructor()) {
3580 FoundConstructor = true;
3581 const FunctionProtoType *CPT
3582 = Constructor->getType()->getAs<FunctionProtoType>();
3583 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
3584 if (!CPT)
3585 return false;
3586 // FIXME: check whether evaluating default arguments can throw.
3587 // For now, we'll be conservative and assume that they can throw.
3588 if (!CPT->isNothrow(Self.Context) || CPT->getNumParams() > 0)
3589 return false;
3590 }
3591 }
3592 return FoundConstructor;
3593 }
3594 return false;
3595 case UTT_HasVirtualDestructor:
3596 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
3597 // If type is a class type with a virtual destructor ([class.dtor])
3598 // then the trait is true, else it is false.
3599 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3600 if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD))
3601 return Destructor->isVirtual();
3602 return false;
3603
3604 // These type trait expressions are modeled on the specifications for the
3605 // Embarcadero C++0x type trait functions:
3606 // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
3607 case UTT_IsCompleteType:
3608 // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_):
3609 // Returns True if and only if T is a complete type at the point of the
3610 // function call.
3611 return !T->isIncompleteType();
3612 }
3613 }
3614
3615 /// \brief Determine whether T has a non-trivial Objective-C lifetime in
3616 /// ARC mode.
hasNontrivialObjCLifetime(QualType T)3617 static bool hasNontrivialObjCLifetime(QualType T) {
3618 switch (T.getObjCLifetime()) {
3619 case Qualifiers::OCL_ExplicitNone:
3620 return false;
3621
3622 case Qualifiers::OCL_Strong:
3623 case Qualifiers::OCL_Weak:
3624 case Qualifiers::OCL_Autoreleasing:
3625 return true;
3626
3627 case Qualifiers::OCL_None:
3628 return T->isObjCLifetimeType();
3629 }
3630
3631 llvm_unreachable("Unknown ObjC lifetime qualifier");
3632 }
3633
3634 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
3635 QualType RhsT, SourceLocation KeyLoc);
3636
evaluateTypeTrait(Sema & S,TypeTrait Kind,SourceLocation KWLoc,ArrayRef<TypeSourceInfo * > Args,SourceLocation RParenLoc)3637 static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc,
3638 ArrayRef<TypeSourceInfo *> Args,
3639 SourceLocation RParenLoc) {
3640 if (Kind <= UTT_Last)
3641 return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType());
3642
3643 if (Kind <= BTT_Last)
3644 return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(),
3645 Args[1]->getType(), RParenLoc);
3646
3647 switch (Kind) {
3648 case clang::TT_IsConstructible:
3649 case clang::TT_IsNothrowConstructible:
3650 case clang::TT_IsTriviallyConstructible: {
3651 // C++11 [meta.unary.prop]:
3652 // is_trivially_constructible is defined as:
3653 //
3654 // is_constructible<T, Args...>::value is true and the variable
3655 // definition for is_constructible, as defined below, is known to call
3656 // no operation that is not trivial.
3657 //
3658 // The predicate condition for a template specialization
3659 // is_constructible<T, Args...> shall be satisfied if and only if the
3660 // following variable definition would be well-formed for some invented
3661 // variable t:
3662 //
3663 // T t(create<Args>()...);
3664 assert(!Args.empty());
3665
3666 // Precondition: T and all types in the parameter pack Args shall be
3667 // complete types, (possibly cv-qualified) void, or arrays of
3668 // unknown bound.
3669 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
3670 QualType ArgTy = Args[I]->getType();
3671 if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType())
3672 continue;
3673
3674 if (S.RequireCompleteType(KWLoc, ArgTy,
3675 diag::err_incomplete_type_used_in_type_trait_expr))
3676 return false;
3677 }
3678
3679 // Make sure the first argument is a complete type.
3680 if (Args[0]->getType()->isIncompleteType())
3681 return false;
3682
3683 // Make sure the first argument is not an abstract type.
3684 CXXRecordDecl *RD = Args[0]->getType()->getAsCXXRecordDecl();
3685 if (RD && RD->isAbstract())
3686 return false;
3687
3688 SmallVector<OpaqueValueExpr, 2> OpaqueArgExprs;
3689 SmallVector<Expr *, 2> ArgExprs;
3690 ArgExprs.reserve(Args.size() - 1);
3691 for (unsigned I = 1, N = Args.size(); I != N; ++I) {
3692 QualType T = Args[I]->getType();
3693 if (T->isObjectType() || T->isFunctionType())
3694 T = S.Context.getRValueReferenceType(T);
3695 OpaqueArgExprs.push_back(
3696 OpaqueValueExpr(Args[I]->getTypeLoc().getLocStart(),
3697 T.getNonLValueExprType(S.Context),
3698 Expr::getValueKindForType(T)));
3699 }
3700 for (Expr &E : OpaqueArgExprs)
3701 ArgExprs.push_back(&E);
3702
3703 // Perform the initialization in an unevaluated context within a SFINAE
3704 // trap at translation unit scope.
3705 EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated);
3706 Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
3707 Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl());
3708 InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0]));
3709 InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc,
3710 RParenLoc));
3711 InitializationSequence Init(S, To, InitKind, ArgExprs);
3712 if (Init.Failed())
3713 return false;
3714
3715 ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs);
3716 if (Result.isInvalid() || SFINAE.hasErrorOccurred())
3717 return false;
3718
3719 if (Kind == clang::TT_IsConstructible)
3720 return true;
3721
3722 if (Kind == clang::TT_IsNothrowConstructible)
3723 return S.canThrow(Result.get()) == CT_Cannot;
3724
3725 if (Kind == clang::TT_IsTriviallyConstructible) {
3726 // Under Objective-C ARC, if the destination has non-trivial Objective-C
3727 // lifetime, this is a non-trivial construction.
3728 if (S.getLangOpts().ObjCAutoRefCount &&
3729 hasNontrivialObjCLifetime(Args[0]->getType().getNonReferenceType()))
3730 return false;
3731
3732 // The initialization succeeded; now make sure there are no non-trivial
3733 // calls.
3734 return !Result.get()->hasNonTrivialCall(S.Context);
3735 }
3736
3737 llvm_unreachable("unhandled type trait");
3738 return false;
3739 }
3740 default: llvm_unreachable("not a TT");
3741 }
3742
3743 return false;
3744 }
3745
BuildTypeTrait(TypeTrait Kind,SourceLocation KWLoc,ArrayRef<TypeSourceInfo * > Args,SourceLocation RParenLoc)3746 ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
3747 ArrayRef<TypeSourceInfo *> Args,
3748 SourceLocation RParenLoc) {
3749 QualType ResultType = Context.getLogicalOperationType();
3750
3751 if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness(
3752 *this, Kind, KWLoc, Args[0]->getType()))
3753 return ExprError();
3754
3755 bool Dependent = false;
3756 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
3757 if (Args[I]->getType()->isDependentType()) {
3758 Dependent = true;
3759 break;
3760 }
3761 }
3762
3763 bool Result = false;
3764 if (!Dependent)
3765 Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc);
3766
3767 return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args,
3768 RParenLoc, Result);
3769 }
3770
ActOnTypeTrait(TypeTrait Kind,SourceLocation KWLoc,ArrayRef<ParsedType> Args,SourceLocation RParenLoc)3771 ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
3772 ArrayRef<ParsedType> Args,
3773 SourceLocation RParenLoc) {
3774 SmallVector<TypeSourceInfo *, 4> ConvertedArgs;
3775 ConvertedArgs.reserve(Args.size());
3776
3777 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
3778 TypeSourceInfo *TInfo;
3779 QualType T = GetTypeFromParser(Args[I], &TInfo);
3780 if (!TInfo)
3781 TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc);
3782
3783 ConvertedArgs.push_back(TInfo);
3784 }
3785
3786 return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc);
3787 }
3788
EvaluateBinaryTypeTrait(Sema & Self,TypeTrait BTT,QualType LhsT,QualType RhsT,SourceLocation KeyLoc)3789 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
3790 QualType RhsT, SourceLocation KeyLoc) {
3791 assert(!LhsT->isDependentType() && !RhsT->isDependentType() &&
3792 "Cannot evaluate traits of dependent types");
3793
3794 switch(BTT) {
3795 case BTT_IsBaseOf: {
3796 // C++0x [meta.rel]p2
3797 // Base is a base class of Derived without regard to cv-qualifiers or
3798 // Base and Derived are not unions and name the same class type without
3799 // regard to cv-qualifiers.
3800
3801 const RecordType *lhsRecord = LhsT->getAs<RecordType>();
3802 if (!lhsRecord) return false;
3803
3804 const RecordType *rhsRecord = RhsT->getAs<RecordType>();
3805 if (!rhsRecord) return false;
3806
3807 assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)
3808 == (lhsRecord == rhsRecord));
3809
3810 if (lhsRecord == rhsRecord)
3811 return !lhsRecord->getDecl()->isUnion();
3812
3813 // C++0x [meta.rel]p2:
3814 // If Base and Derived are class types and are different types
3815 // (ignoring possible cv-qualifiers) then Derived shall be a
3816 // complete type.
3817 if (Self.RequireCompleteType(KeyLoc, RhsT,
3818 diag::err_incomplete_type_used_in_type_trait_expr))
3819 return false;
3820
3821 return cast<CXXRecordDecl>(rhsRecord->getDecl())
3822 ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl()));
3823 }
3824 case BTT_IsSame:
3825 return Self.Context.hasSameType(LhsT, RhsT);
3826 case BTT_TypeCompatible:
3827 return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(),
3828 RhsT.getUnqualifiedType());
3829 case BTT_IsConvertible:
3830 case BTT_IsConvertibleTo: {
3831 // C++0x [meta.rel]p4:
3832 // Given the following function prototype:
3833 //
3834 // template <class T>
3835 // typename add_rvalue_reference<T>::type create();
3836 //
3837 // the predicate condition for a template specialization
3838 // is_convertible<From, To> shall be satisfied if and only if
3839 // the return expression in the following code would be
3840 // well-formed, including any implicit conversions to the return
3841 // type of the function:
3842 //
3843 // To test() {
3844 // return create<From>();
3845 // }
3846 //
3847 // Access checking is performed as if in a context unrelated to To and
3848 // From. Only the validity of the immediate context of the expression
3849 // of the return-statement (including conversions to the return type)
3850 // is considered.
3851 //
3852 // We model the initialization as a copy-initialization of a temporary
3853 // of the appropriate type, which for this expression is identical to the
3854 // return statement (since NRVO doesn't apply).
3855
3856 // Functions aren't allowed to return function or array types.
3857 if (RhsT->isFunctionType() || RhsT->isArrayType())
3858 return false;
3859
3860 // A return statement in a void function must have void type.
3861 if (RhsT->isVoidType())
3862 return LhsT->isVoidType();
3863
3864 // A function definition requires a complete, non-abstract return type.
3865 if (Self.RequireCompleteType(KeyLoc, RhsT, 0) ||
3866 Self.RequireNonAbstractType(KeyLoc, RhsT, 0))
3867 return false;
3868
3869 // Compute the result of add_rvalue_reference.
3870 if (LhsT->isObjectType() || LhsT->isFunctionType())
3871 LhsT = Self.Context.getRValueReferenceType(LhsT);
3872
3873 // Build a fake source and destination for initialization.
3874 InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT));
3875 OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
3876 Expr::getValueKindForType(LhsT));
3877 Expr *FromPtr = &From;
3878 InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc,
3879 SourceLocation()));
3880
3881 // Perform the initialization in an unevaluated context within a SFINAE
3882 // trap at translation unit scope.
3883 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated);
3884 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
3885 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
3886 InitializationSequence Init(Self, To, Kind, FromPtr);
3887 if (Init.Failed())
3888 return false;
3889
3890 ExprResult Result = Init.Perform(Self, To, Kind, FromPtr);
3891 return !Result.isInvalid() && !SFINAE.hasErrorOccurred();
3892 }
3893
3894 case BTT_IsNothrowAssignable:
3895 case BTT_IsTriviallyAssignable: {
3896 // C++11 [meta.unary.prop]p3:
3897 // is_trivially_assignable is defined as:
3898 // is_assignable<T, U>::value is true and the assignment, as defined by
3899 // is_assignable, is known to call no operation that is not trivial
3900 //
3901 // is_assignable is defined as:
3902 // The expression declval<T>() = declval<U>() is well-formed when
3903 // treated as an unevaluated operand (Clause 5).
3904 //
3905 // For both, T and U shall be complete types, (possibly cv-qualified)
3906 // void, or arrays of unknown bound.
3907 if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() &&
3908 Self.RequireCompleteType(KeyLoc, LhsT,
3909 diag::err_incomplete_type_used_in_type_trait_expr))
3910 return false;
3911 if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() &&
3912 Self.RequireCompleteType(KeyLoc, RhsT,
3913 diag::err_incomplete_type_used_in_type_trait_expr))
3914 return false;
3915
3916 // cv void is never assignable.
3917 if (LhsT->isVoidType() || RhsT->isVoidType())
3918 return false;
3919
3920 // Build expressions that emulate the effect of declval<T>() and
3921 // declval<U>().
3922 if (LhsT->isObjectType() || LhsT->isFunctionType())
3923 LhsT = Self.Context.getRValueReferenceType(LhsT);
3924 if (RhsT->isObjectType() || RhsT->isFunctionType())
3925 RhsT = Self.Context.getRValueReferenceType(RhsT);
3926 OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
3927 Expr::getValueKindForType(LhsT));
3928 OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context),
3929 Expr::getValueKindForType(RhsT));
3930
3931 // Attempt the assignment in an unevaluated context within a SFINAE
3932 // trap at translation unit scope.
3933 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated);
3934 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
3935 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
3936 ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs,
3937 &Rhs);
3938 if (Result.isInvalid() || SFINAE.hasErrorOccurred())
3939 return false;
3940
3941 if (BTT == BTT_IsNothrowAssignable)
3942 return Self.canThrow(Result.get()) == CT_Cannot;
3943
3944 if (BTT == BTT_IsTriviallyAssignable) {
3945 // Under Objective-C ARC, if the destination has non-trivial Objective-C
3946 // lifetime, this is a non-trivial assignment.
3947 if (Self.getLangOpts().ObjCAutoRefCount &&
3948 hasNontrivialObjCLifetime(LhsT.getNonReferenceType()))
3949 return false;
3950
3951 return !Result.get()->hasNonTrivialCall(Self.Context);
3952 }
3953
3954 llvm_unreachable("unhandled type trait");
3955 return false;
3956 }
3957 default: llvm_unreachable("not a BTT");
3958 }
3959 llvm_unreachable("Unknown type trait or not implemented");
3960 }
3961
ActOnArrayTypeTrait(ArrayTypeTrait ATT,SourceLocation KWLoc,ParsedType Ty,Expr * DimExpr,SourceLocation RParen)3962 ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT,
3963 SourceLocation KWLoc,
3964 ParsedType Ty,
3965 Expr* DimExpr,
3966 SourceLocation RParen) {
3967 TypeSourceInfo *TSInfo;
3968 QualType T = GetTypeFromParser(Ty, &TSInfo);
3969 if (!TSInfo)
3970 TSInfo = Context.getTrivialTypeSourceInfo(T);
3971
3972 return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen);
3973 }
3974
EvaluateArrayTypeTrait(Sema & Self,ArrayTypeTrait ATT,QualType T,Expr * DimExpr,SourceLocation KeyLoc)3975 static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT,
3976 QualType T, Expr *DimExpr,
3977 SourceLocation KeyLoc) {
3978 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
3979
3980 switch(ATT) {
3981 case ATT_ArrayRank:
3982 if (T->isArrayType()) {
3983 unsigned Dim = 0;
3984 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
3985 ++Dim;
3986 T = AT->getElementType();
3987 }
3988 return Dim;
3989 }
3990 return 0;
3991
3992 case ATT_ArrayExtent: {
3993 llvm::APSInt Value;
3994 uint64_t Dim;
3995 if (Self.VerifyIntegerConstantExpression(DimExpr, &Value,
3996 diag::err_dimension_expr_not_constant_integer,
3997 false).isInvalid())
3998 return 0;
3999 if (Value.isSigned() && Value.isNegative()) {
4000 Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer)
4001 << DimExpr->getSourceRange();
4002 return 0;
4003 }
4004 Dim = Value.getLimitedValue();
4005
4006 if (T->isArrayType()) {
4007 unsigned D = 0;
4008 bool Matched = false;
4009 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
4010 if (Dim == D) {
4011 Matched = true;
4012 break;
4013 }
4014 ++D;
4015 T = AT->getElementType();
4016 }
4017
4018 if (Matched && T->isArrayType()) {
4019 if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T))
4020 return CAT->getSize().getLimitedValue();
4021 }
4022 }
4023 return 0;
4024 }
4025 }
4026 llvm_unreachable("Unknown type trait or not implemented");
4027 }
4028
BuildArrayTypeTrait(ArrayTypeTrait ATT,SourceLocation KWLoc,TypeSourceInfo * TSInfo,Expr * DimExpr,SourceLocation RParen)4029 ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT,
4030 SourceLocation KWLoc,
4031 TypeSourceInfo *TSInfo,
4032 Expr* DimExpr,
4033 SourceLocation RParen) {
4034 QualType T = TSInfo->getType();
4035
4036 // FIXME: This should likely be tracked as an APInt to remove any host
4037 // assumptions about the width of size_t on the target.
4038 uint64_t Value = 0;
4039 if (!T->isDependentType())
4040 Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc);
4041
4042 // While the specification for these traits from the Embarcadero C++
4043 // compiler's documentation says the return type is 'unsigned int', Clang
4044 // returns 'size_t'. On Windows, the primary platform for the Embarcadero
4045 // compiler, there is no difference. On several other platforms this is an
4046 // important distinction.
4047 return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr,
4048 RParen, Context.getSizeType());
4049 }
4050
ActOnExpressionTrait(ExpressionTrait ET,SourceLocation KWLoc,Expr * Queried,SourceLocation RParen)4051 ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET,
4052 SourceLocation KWLoc,
4053 Expr *Queried,
4054 SourceLocation RParen) {
4055 // If error parsing the expression, ignore.
4056 if (!Queried)
4057 return ExprError();
4058
4059 ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen);
4060
4061 return Result;
4062 }
4063
EvaluateExpressionTrait(ExpressionTrait ET,Expr * E)4064 static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) {
4065 switch (ET) {
4066 case ET_IsLValueExpr: return E->isLValue();
4067 case ET_IsRValueExpr: return E->isRValue();
4068 }
4069 llvm_unreachable("Expression trait not covered by switch");
4070 }
4071
BuildExpressionTrait(ExpressionTrait ET,SourceLocation KWLoc,Expr * Queried,SourceLocation RParen)4072 ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET,
4073 SourceLocation KWLoc,
4074 Expr *Queried,
4075 SourceLocation RParen) {
4076 if (Queried->isTypeDependent()) {
4077 // Delay type-checking for type-dependent expressions.
4078 } else if (Queried->getType()->isPlaceholderType()) {
4079 ExprResult PE = CheckPlaceholderExpr(Queried);
4080 if (PE.isInvalid()) return ExprError();
4081 return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen);
4082 }
4083
4084 bool Value = EvaluateExpressionTrait(ET, Queried);
4085
4086 return new (Context)
4087 ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy);
4088 }
4089
CheckPointerToMemberOperands(ExprResult & LHS,ExprResult & RHS,ExprValueKind & VK,SourceLocation Loc,bool isIndirect)4090 QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS,
4091 ExprValueKind &VK,
4092 SourceLocation Loc,
4093 bool isIndirect) {
4094 assert(!LHS.get()->getType()->isPlaceholderType() &&
4095 !RHS.get()->getType()->isPlaceholderType() &&
4096 "placeholders should have been weeded out by now");
4097
4098 // The LHS undergoes lvalue conversions if this is ->*.
4099 if (isIndirect) {
4100 LHS = DefaultLvalueConversion(LHS.get());
4101 if (LHS.isInvalid()) return QualType();
4102 }
4103
4104 // The RHS always undergoes lvalue conversions.
4105 RHS = DefaultLvalueConversion(RHS.get());
4106 if (RHS.isInvalid()) return QualType();
4107
4108 const char *OpSpelling = isIndirect ? "->*" : ".*";
4109 // C++ 5.5p2
4110 // The binary operator .* [p3: ->*] binds its second operand, which shall
4111 // be of type "pointer to member of T" (where T is a completely-defined
4112 // class type) [...]
4113 QualType RHSType = RHS.get()->getType();
4114 const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>();
4115 if (!MemPtr) {
4116 Diag(Loc, diag::err_bad_memptr_rhs)
4117 << OpSpelling << RHSType << RHS.get()->getSourceRange();
4118 return QualType();
4119 }
4120
4121 QualType Class(MemPtr->getClass(), 0);
4122
4123 // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the
4124 // member pointer points must be completely-defined. However, there is no
4125 // reason for this semantic distinction, and the rule is not enforced by
4126 // other compilers. Therefore, we do not check this property, as it is
4127 // likely to be considered a defect.
4128
4129 // C++ 5.5p2
4130 // [...] to its first operand, which shall be of class T or of a class of
4131 // which T is an unambiguous and accessible base class. [p3: a pointer to
4132 // such a class]
4133 QualType LHSType = LHS.get()->getType();
4134 if (isIndirect) {
4135 if (const PointerType *Ptr = LHSType->getAs<PointerType>())
4136 LHSType = Ptr->getPointeeType();
4137 else {
4138 Diag(Loc, diag::err_bad_memptr_lhs)
4139 << OpSpelling << 1 << LHSType
4140 << FixItHint::CreateReplacement(SourceRange(Loc), ".*");
4141 return QualType();
4142 }
4143 }
4144
4145 if (!Context.hasSameUnqualifiedType(Class, LHSType)) {
4146 // If we want to check the hierarchy, we need a complete type.
4147 if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs,
4148 OpSpelling, (int)isIndirect)) {
4149 return QualType();
4150 }
4151
4152 if (!IsDerivedFrom(LHSType, Class)) {
4153 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling
4154 << (int)isIndirect << LHS.get()->getType();
4155 return QualType();
4156 }
4157
4158 CXXCastPath BasePath;
4159 if (CheckDerivedToBaseConversion(LHSType, Class, Loc,
4160 SourceRange(LHS.get()->getLocStart(),
4161 RHS.get()->getLocEnd()),
4162 &BasePath))
4163 return QualType();
4164
4165 // Cast LHS to type of use.
4166 QualType UseType = isIndirect ? Context.getPointerType(Class) : Class;
4167 ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind();
4168 LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK,
4169 &BasePath);
4170 }
4171
4172 if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) {
4173 // Diagnose use of pointer-to-member type which when used as
4174 // the functional cast in a pointer-to-member expression.
4175 Diag(Loc, diag::err_pointer_to_member_type) << isIndirect;
4176 return QualType();
4177 }
4178
4179 // C++ 5.5p2
4180 // The result is an object or a function of the type specified by the
4181 // second operand.
4182 // The cv qualifiers are the union of those in the pointer and the left side,
4183 // in accordance with 5.5p5 and 5.2.5.
4184 QualType Result = MemPtr->getPointeeType();
4185 Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers());
4186
4187 // C++0x [expr.mptr.oper]p6:
4188 // In a .* expression whose object expression is an rvalue, the program is
4189 // ill-formed if the second operand is a pointer to member function with
4190 // ref-qualifier &. In a ->* expression or in a .* expression whose object
4191 // expression is an lvalue, the program is ill-formed if the second operand
4192 // is a pointer to member function with ref-qualifier &&.
4193 if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) {
4194 switch (Proto->getRefQualifier()) {
4195 case RQ_None:
4196 // Do nothing
4197 break;
4198
4199 case RQ_LValue:
4200 if (!isIndirect && !LHS.get()->Classify(Context).isLValue())
4201 Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
4202 << RHSType << 1 << LHS.get()->getSourceRange();
4203 break;
4204
4205 case RQ_RValue:
4206 if (isIndirect || !LHS.get()->Classify(Context).isRValue())
4207 Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
4208 << RHSType << 0 << LHS.get()->getSourceRange();
4209 break;
4210 }
4211 }
4212
4213 // C++ [expr.mptr.oper]p6:
4214 // The result of a .* expression whose second operand is a pointer
4215 // to a data member is of the same value category as its
4216 // first operand. The result of a .* expression whose second
4217 // operand is a pointer to a member function is a prvalue. The
4218 // result of an ->* expression is an lvalue if its second operand
4219 // is a pointer to data member and a prvalue otherwise.
4220 if (Result->isFunctionType()) {
4221 VK = VK_RValue;
4222 return Context.BoundMemberTy;
4223 } else if (isIndirect) {
4224 VK = VK_LValue;
4225 } else {
4226 VK = LHS.get()->getValueKind();
4227 }
4228
4229 return Result;
4230 }
4231
4232 /// \brief Try to convert a type to another according to C++0x 5.16p3.
4233 ///
4234 /// This is part of the parameter validation for the ? operator. If either
4235 /// value operand is a class type, the two operands are attempted to be
4236 /// converted to each other. This function does the conversion in one direction.
4237 /// It returns true if the program is ill-formed and has already been diagnosed
4238 /// as such.
TryClassUnification(Sema & Self,Expr * From,Expr * To,SourceLocation QuestionLoc,bool & HaveConversion,QualType & ToType)4239 static bool TryClassUnification(Sema &Self, Expr *From, Expr *To,
4240 SourceLocation QuestionLoc,
4241 bool &HaveConversion,
4242 QualType &ToType) {
4243 HaveConversion = false;
4244 ToType = To->getType();
4245
4246 InitializationKind Kind = InitializationKind::CreateCopy(To->getLocStart(),
4247 SourceLocation());
4248 // C++0x 5.16p3
4249 // The process for determining whether an operand expression E1 of type T1
4250 // can be converted to match an operand expression E2 of type T2 is defined
4251 // as follows:
4252 // -- If E2 is an lvalue:
4253 bool ToIsLvalue = To->isLValue();
4254 if (ToIsLvalue) {
4255 // E1 can be converted to match E2 if E1 can be implicitly converted to
4256 // type "lvalue reference to T2", subject to the constraint that in the
4257 // conversion the reference must bind directly to E1.
4258 QualType T = Self.Context.getLValueReferenceType(ToType);
4259 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);
4260
4261 InitializationSequence InitSeq(Self, Entity, Kind, From);
4262 if (InitSeq.isDirectReferenceBinding()) {
4263 ToType = T;
4264 HaveConversion = true;
4265 return false;
4266 }
4267
4268 if (InitSeq.isAmbiguous())
4269 return InitSeq.Diagnose(Self, Entity, Kind, From);
4270 }
4271
4272 // -- If E2 is an rvalue, or if the conversion above cannot be done:
4273 // -- if E1 and E2 have class type, and the underlying class types are
4274 // the same or one is a base class of the other:
4275 QualType FTy = From->getType();
4276 QualType TTy = To->getType();
4277 const RecordType *FRec = FTy->getAs<RecordType>();
4278 const RecordType *TRec = TTy->getAs<RecordType>();
4279 bool FDerivedFromT = FRec && TRec && FRec != TRec &&
4280 Self.IsDerivedFrom(FTy, TTy);
4281 if (FRec && TRec &&
4282 (FRec == TRec || FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) {
4283 // E1 can be converted to match E2 if the class of T2 is the
4284 // same type as, or a base class of, the class of T1, and
4285 // [cv2 > cv1].
4286 if (FRec == TRec || FDerivedFromT) {
4287 if (TTy.isAtLeastAsQualifiedAs(FTy)) {
4288 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
4289 InitializationSequence InitSeq(Self, Entity, Kind, From);
4290 if (InitSeq) {
4291 HaveConversion = true;
4292 return false;
4293 }
4294
4295 if (InitSeq.isAmbiguous())
4296 return InitSeq.Diagnose(Self, Entity, Kind, From);
4297 }
4298 }
4299
4300 return false;
4301 }
4302
4303 // -- Otherwise: E1 can be converted to match E2 if E1 can be
4304 // implicitly converted to the type that expression E2 would have
4305 // if E2 were converted to an rvalue (or the type it has, if E2 is
4306 // an rvalue).
4307 //
4308 // This actually refers very narrowly to the lvalue-to-rvalue conversion, not
4309 // to the array-to-pointer or function-to-pointer conversions.
4310 if (!TTy->getAs<TagType>())
4311 TTy = TTy.getUnqualifiedType();
4312
4313 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
4314 InitializationSequence InitSeq(Self, Entity, Kind, From);
4315 HaveConversion = !InitSeq.Failed();
4316 ToType = TTy;
4317 if (InitSeq.isAmbiguous())
4318 return InitSeq.Diagnose(Self, Entity, Kind, From);
4319
4320 return false;
4321 }
4322
4323 /// \brief Try to find a common type for two according to C++0x 5.16p5.
4324 ///
4325 /// This is part of the parameter validation for the ? operator. If either
4326 /// value operand is a class type, overload resolution is used to find a
4327 /// conversion to a common type.
FindConditionalOverload(Sema & Self,ExprResult & LHS,ExprResult & RHS,SourceLocation QuestionLoc)4328 static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS,
4329 SourceLocation QuestionLoc) {
4330 Expr *Args[2] = { LHS.get(), RHS.get() };
4331 OverloadCandidateSet CandidateSet(QuestionLoc,
4332 OverloadCandidateSet::CSK_Operator);
4333 Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args,
4334 CandidateSet);
4335
4336 OverloadCandidateSet::iterator Best;
4337 switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) {
4338 case OR_Success: {
4339 // We found a match. Perform the conversions on the arguments and move on.
4340 ExprResult LHSRes =
4341 Self.PerformImplicitConversion(LHS.get(), Best->BuiltinTypes.ParamTypes[0],
4342 Best->Conversions[0], Sema::AA_Converting);
4343 if (LHSRes.isInvalid())
4344 break;
4345 LHS = LHSRes;
4346
4347 ExprResult RHSRes =
4348 Self.PerformImplicitConversion(RHS.get(), Best->BuiltinTypes.ParamTypes[1],
4349 Best->Conversions[1], Sema::AA_Converting);
4350 if (RHSRes.isInvalid())
4351 break;
4352 RHS = RHSRes;
4353 if (Best->Function)
4354 Self.MarkFunctionReferenced(QuestionLoc, Best->Function);
4355 return false;
4356 }
4357
4358 case OR_No_Viable_Function:
4359
4360 // Emit a better diagnostic if one of the expressions is a null pointer
4361 // constant and the other is a pointer type. In this case, the user most
4362 // likely forgot to take the address of the other expression.
4363 if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
4364 return true;
4365
4366 Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
4367 << LHS.get()->getType() << RHS.get()->getType()
4368 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
4369 return true;
4370
4371 case OR_Ambiguous:
4372 Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl)
4373 << LHS.get()->getType() << RHS.get()->getType()
4374 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
4375 // FIXME: Print the possible common types by printing the return types of
4376 // the viable candidates.
4377 break;
4378
4379 case OR_Deleted:
4380 llvm_unreachable("Conditional operator has only built-in overloads");
4381 }
4382 return true;
4383 }
4384
4385 /// \brief Perform an "extended" implicit conversion as returned by
4386 /// TryClassUnification.
ConvertForConditional(Sema & Self,ExprResult & E,QualType T)4387 static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) {
4388 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);
4389 InitializationKind Kind = InitializationKind::CreateCopy(E.get()->getLocStart(),
4390 SourceLocation());
4391 Expr *Arg = E.get();
4392 InitializationSequence InitSeq(Self, Entity, Kind, Arg);
4393 ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg);
4394 if (Result.isInvalid())
4395 return true;
4396
4397 E = Result;
4398 return false;
4399 }
4400
4401 /// \brief Check the operands of ?: under C++ semantics.
4402 ///
4403 /// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y
4404 /// extension. In this case, LHS == Cond. (But they're not aliases.)
CXXCheckConditionalOperands(ExprResult & Cond,ExprResult & LHS,ExprResult & RHS,ExprValueKind & VK,ExprObjectKind & OK,SourceLocation QuestionLoc)4405 QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS,
4406 ExprResult &RHS, ExprValueKind &VK,
4407 ExprObjectKind &OK,
4408 SourceLocation QuestionLoc) {
4409 // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++
4410 // interface pointers.
4411
4412 // C++11 [expr.cond]p1
4413 // The first expression is contextually converted to bool.
4414 if (!Cond.get()->isTypeDependent()) {
4415 ExprResult CondRes = CheckCXXBooleanCondition(Cond.get());
4416 if (CondRes.isInvalid())
4417 return QualType();
4418 Cond = CondRes;
4419 }
4420
4421 // Assume r-value.
4422 VK = VK_RValue;
4423 OK = OK_Ordinary;
4424
4425 // Either of the arguments dependent?
4426 if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent())
4427 return Context.DependentTy;
4428
4429 // C++11 [expr.cond]p2
4430 // If either the second or the third operand has type (cv) void, ...
4431 QualType LTy = LHS.get()->getType();
4432 QualType RTy = RHS.get()->getType();
4433 bool LVoid = LTy->isVoidType();
4434 bool RVoid = RTy->isVoidType();
4435 if (LVoid || RVoid) {
4436 // ... one of the following shall hold:
4437 // -- The second or the third operand (but not both) is a (possibly
4438 // parenthesized) throw-expression; the result is of the type
4439 // and value category of the other.
4440 bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts());
4441 bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts());
4442 if (LThrow != RThrow) {
4443 Expr *NonThrow = LThrow ? RHS.get() : LHS.get();
4444 VK = NonThrow->getValueKind();
4445 // DR (no number yet): the result is a bit-field if the
4446 // non-throw-expression operand is a bit-field.
4447 OK = NonThrow->getObjectKind();
4448 return NonThrow->getType();
4449 }
4450
4451 // -- Both the second and third operands have type void; the result is of
4452 // type void and is a prvalue.
4453 if (LVoid && RVoid)
4454 return Context.VoidTy;
4455
4456 // Neither holds, error.
4457 Diag(QuestionLoc, diag::err_conditional_void_nonvoid)
4458 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1)
4459 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
4460 return QualType();
4461 }
4462
4463 // Neither is void.
4464
4465 // C++11 [expr.cond]p3
4466 // Otherwise, if the second and third operand have different types, and
4467 // either has (cv) class type [...] an attempt is made to convert each of
4468 // those operands to the type of the other.
4469 if (!Context.hasSameType(LTy, RTy) &&
4470 (LTy->isRecordType() || RTy->isRecordType())) {
4471 // These return true if a single direction is already ambiguous.
4472 QualType L2RType, R2LType;
4473 bool HaveL2R, HaveR2L;
4474 if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType))
4475 return QualType();
4476 if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType))
4477 return QualType();
4478
4479 // If both can be converted, [...] the program is ill-formed.
4480 if (HaveL2R && HaveR2L) {
4481 Diag(QuestionLoc, diag::err_conditional_ambiguous)
4482 << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
4483 return QualType();
4484 }
4485
4486 // If exactly one conversion is possible, that conversion is applied to
4487 // the chosen operand and the converted operands are used in place of the
4488 // original operands for the remainder of this section.
4489 if (HaveL2R) {
4490 if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid())
4491 return QualType();
4492 LTy = LHS.get()->getType();
4493 } else if (HaveR2L) {
4494 if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid())
4495 return QualType();
4496 RTy = RHS.get()->getType();
4497 }
4498 }
4499
4500 // C++11 [expr.cond]p3
4501 // if both are glvalues of the same value category and the same type except
4502 // for cv-qualification, an attempt is made to convert each of those
4503 // operands to the type of the other.
4504 ExprValueKind LVK = LHS.get()->getValueKind();
4505 ExprValueKind RVK = RHS.get()->getValueKind();
4506 if (!Context.hasSameType(LTy, RTy) &&
4507 Context.hasSameUnqualifiedType(LTy, RTy) &&
4508 LVK == RVK && LVK != VK_RValue) {
4509 // Since the unqualified types are reference-related and we require the
4510 // result to be as if a reference bound directly, the only conversion
4511 // we can perform is to add cv-qualifiers.
4512 Qualifiers LCVR = Qualifiers::fromCVRMask(LTy.getCVRQualifiers());
4513 Qualifiers RCVR = Qualifiers::fromCVRMask(RTy.getCVRQualifiers());
4514 if (RCVR.isStrictSupersetOf(LCVR)) {
4515 LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK);
4516 LTy = LHS.get()->getType();
4517 }
4518 else if (LCVR.isStrictSupersetOf(RCVR)) {
4519 RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK);
4520 RTy = RHS.get()->getType();
4521 }
4522 }
4523
4524 // C++11 [expr.cond]p4
4525 // If the second and third operands are glvalues of the same value
4526 // category and have the same type, the result is of that type and
4527 // value category and it is a bit-field if the second or the third
4528 // operand is a bit-field, or if both are bit-fields.
4529 // We only extend this to bitfields, not to the crazy other kinds of
4530 // l-values.
4531 bool Same = Context.hasSameType(LTy, RTy);
4532 if (Same && LVK == RVK && LVK != VK_RValue &&
4533 LHS.get()->isOrdinaryOrBitFieldObject() &&
4534 RHS.get()->isOrdinaryOrBitFieldObject()) {
4535 VK = LHS.get()->getValueKind();
4536 if (LHS.get()->getObjectKind() == OK_BitField ||
4537 RHS.get()->getObjectKind() == OK_BitField)
4538 OK = OK_BitField;
4539 return LTy;
4540 }
4541
4542 // C++11 [expr.cond]p5
4543 // Otherwise, the result is a prvalue. If the second and third operands
4544 // do not have the same type, and either has (cv) class type, ...
4545 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) {
4546 // ... overload resolution is used to determine the conversions (if any)
4547 // to be applied to the operands. If the overload resolution fails, the
4548 // program is ill-formed.
4549 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc))
4550 return QualType();
4551 }
4552
4553 // C++11 [expr.cond]p6
4554 // Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
4555 // conversions are performed on the second and third operands.
4556 LHS = DefaultFunctionArrayLvalueConversion(LHS.get());
4557 RHS = DefaultFunctionArrayLvalueConversion(RHS.get());
4558 if (LHS.isInvalid() || RHS.isInvalid())
4559 return QualType();
4560 LTy = LHS.get()->getType();
4561 RTy = RHS.get()->getType();
4562
4563 // After those conversions, one of the following shall hold:
4564 // -- The second and third operands have the same type; the result
4565 // is of that type. If the operands have class type, the result
4566 // is a prvalue temporary of the result type, which is
4567 // copy-initialized from either the second operand or the third
4568 // operand depending on the value of the first operand.
4569 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) {
4570 if (LTy->isRecordType()) {
4571 // The operands have class type. Make a temporary copy.
4572 if (RequireNonAbstractType(QuestionLoc, LTy,
4573 diag::err_allocation_of_abstract_type))
4574 return QualType();
4575 InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy);
4576
4577 ExprResult LHSCopy = PerformCopyInitialization(Entity,
4578 SourceLocation(),
4579 LHS);
4580 if (LHSCopy.isInvalid())
4581 return QualType();
4582
4583 ExprResult RHSCopy = PerformCopyInitialization(Entity,
4584 SourceLocation(),
4585 RHS);
4586 if (RHSCopy.isInvalid())
4587 return QualType();
4588
4589 LHS = LHSCopy;
4590 RHS = RHSCopy;
4591 }
4592
4593 return LTy;
4594 }
4595
4596 // Extension: conditional operator involving vector types.
4597 if (LTy->isVectorType() || RTy->isVectorType())
4598 return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false);
4599
4600 // -- The second and third operands have arithmetic or enumeration type;
4601 // the usual arithmetic conversions are performed to bring them to a
4602 // common type, and the result is of that type.
4603 if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
4604 QualType ResTy = UsualArithmeticConversions(LHS, RHS);
4605 if (LHS.isInvalid() || RHS.isInvalid())
4606 return QualType();
4607
4608 LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy));
4609 RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy));
4610
4611 return ResTy;
4612 }
4613
4614 // -- The second and third operands have pointer type, or one has pointer
4615 // type and the other is a null pointer constant, or both are null
4616 // pointer constants, at least one of which is non-integral; pointer
4617 // conversions and qualification conversions are performed to bring them
4618 // to their composite pointer type. The result is of the composite
4619 // pointer type.
4620 // -- The second and third operands have pointer to member type, or one has
4621 // pointer to member type and the other is a null pointer constant;
4622 // pointer to member conversions and qualification conversions are
4623 // performed to bring them to a common type, whose cv-qualification
4624 // shall match the cv-qualification of either the second or the third
4625 // operand. The result is of the common type.
4626 bool NonStandardCompositeType = false;
4627 QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS,
4628 isSFINAEContext() ? nullptr
4629 : &NonStandardCompositeType);
4630 if (!Composite.isNull()) {
4631 if (NonStandardCompositeType)
4632 Diag(QuestionLoc,
4633 diag::ext_typecheck_cond_incompatible_operands_nonstandard)
4634 << LTy << RTy << Composite
4635 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
4636
4637 return Composite;
4638 }
4639
4640 // Similarly, attempt to find composite type of two objective-c pointers.
4641 Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc);
4642 if (!Composite.isNull())
4643 return Composite;
4644
4645 // Check if we are using a null with a non-pointer type.
4646 if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
4647 return QualType();
4648
4649 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
4650 << LHS.get()->getType() << RHS.get()->getType()
4651 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
4652 return QualType();
4653 }
4654
4655 /// \brief Find a merged pointer type and convert the two expressions to it.
4656 ///
4657 /// This finds the composite pointer type (or member pointer type) for @p E1
4658 /// and @p E2 according to C++11 5.9p2. It converts both expressions to this
4659 /// type and returns it.
4660 /// It does not emit diagnostics.
4661 ///
4662 /// \param Loc The location of the operator requiring these two expressions to
4663 /// be converted to the composite pointer type.
4664 ///
4665 /// If \p NonStandardCompositeType is non-NULL, then we are permitted to find
4666 /// a non-standard (but still sane) composite type to which both expressions
4667 /// can be converted. When such a type is chosen, \c *NonStandardCompositeType
4668 /// will be set true.
FindCompositePointerType(SourceLocation Loc,Expr * & E1,Expr * & E2,bool * NonStandardCompositeType)4669 QualType Sema::FindCompositePointerType(SourceLocation Loc,
4670 Expr *&E1, Expr *&E2,
4671 bool *NonStandardCompositeType) {
4672 if (NonStandardCompositeType)
4673 *NonStandardCompositeType = false;
4674
4675 assert(getLangOpts().CPlusPlus && "This function assumes C++");
4676 QualType T1 = E1->getType(), T2 = E2->getType();
4677
4678 // C++11 5.9p2
4679 // Pointer conversions and qualification conversions are performed on
4680 // pointer operands to bring them to their composite pointer type. If
4681 // one operand is a null pointer constant, the composite pointer type is
4682 // std::nullptr_t if the other operand is also a null pointer constant or,
4683 // if the other operand is a pointer, the type of the other operand.
4684 if (!T1->isAnyPointerType() && !T1->isMemberPointerType() &&
4685 !T2->isAnyPointerType() && !T2->isMemberPointerType()) {
4686 if (T1->isNullPtrType() &&
4687 E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
4688 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get();
4689 return T1;
4690 }
4691 if (T2->isNullPtrType() &&
4692 E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
4693 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get();
4694 return T2;
4695 }
4696 return QualType();
4697 }
4698
4699 if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
4700 if (T2->isMemberPointerType())
4701 E1 = ImpCastExprToType(E1, T2, CK_NullToMemberPointer).get();
4702 else
4703 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get();
4704 return T2;
4705 }
4706 if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
4707 if (T1->isMemberPointerType())
4708 E2 = ImpCastExprToType(E2, T1, CK_NullToMemberPointer).get();
4709 else
4710 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get();
4711 return T1;
4712 }
4713
4714 // Now both have to be pointers or member pointers.
4715 if ((!T1->isPointerType() && !T1->isMemberPointerType()) ||
4716 (!T2->isPointerType() && !T2->isMemberPointerType()))
4717 return QualType();
4718
4719 // Otherwise, of one of the operands has type "pointer to cv1 void," then
4720 // the other has type "pointer to cv2 T" and the composite pointer type is
4721 // "pointer to cv12 void," where cv12 is the union of cv1 and cv2.
4722 // Otherwise, the composite pointer type is a pointer type similar to the
4723 // type of one of the operands, with a cv-qualification signature that is
4724 // the union of the cv-qualification signatures of the operand types.
4725 // In practice, the first part here is redundant; it's subsumed by the second.
4726 // What we do here is, we build the two possible composite types, and try the
4727 // conversions in both directions. If only one works, or if the two composite
4728 // types are the same, we have succeeded.
4729 // FIXME: extended qualifiers?
4730 typedef SmallVector<unsigned, 4> QualifierVector;
4731 QualifierVector QualifierUnion;
4732 typedef SmallVector<std::pair<const Type *, const Type *>, 4>
4733 ContainingClassVector;
4734 ContainingClassVector MemberOfClass;
4735 QualType Composite1 = Context.getCanonicalType(T1),
4736 Composite2 = Context.getCanonicalType(T2);
4737 unsigned NeedConstBefore = 0;
4738 do {
4739 const PointerType *Ptr1, *Ptr2;
4740 if ((Ptr1 = Composite1->getAs<PointerType>()) &&
4741 (Ptr2 = Composite2->getAs<PointerType>())) {
4742 Composite1 = Ptr1->getPointeeType();
4743 Composite2 = Ptr2->getPointeeType();
4744
4745 // If we're allowed to create a non-standard composite type, keep track
4746 // of where we need to fill in additional 'const' qualifiers.
4747 if (NonStandardCompositeType &&
4748 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers())
4749 NeedConstBefore = QualifierUnion.size();
4750
4751 QualifierUnion.push_back(
4752 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
4753 MemberOfClass.push_back(std::make_pair(nullptr, nullptr));
4754 continue;
4755 }
4756
4757 const MemberPointerType *MemPtr1, *MemPtr2;
4758 if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) &&
4759 (MemPtr2 = Composite2->getAs<MemberPointerType>())) {
4760 Composite1 = MemPtr1->getPointeeType();
4761 Composite2 = MemPtr2->getPointeeType();
4762
4763 // If we're allowed to create a non-standard composite type, keep track
4764 // of where we need to fill in additional 'const' qualifiers.
4765 if (NonStandardCompositeType &&
4766 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers())
4767 NeedConstBefore = QualifierUnion.size();
4768
4769 QualifierUnion.push_back(
4770 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
4771 MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(),
4772 MemPtr2->getClass()));
4773 continue;
4774 }
4775
4776 // FIXME: block pointer types?
4777
4778 // Cannot unwrap any more types.
4779 break;
4780 } while (true);
4781
4782 if (NeedConstBefore && NonStandardCompositeType) {
4783 // Extension: Add 'const' to qualifiers that come before the first qualifier
4784 // mismatch, so that our (non-standard!) composite type meets the
4785 // requirements of C++ [conv.qual]p4 bullet 3.
4786 for (unsigned I = 0; I != NeedConstBefore; ++I) {
4787 if ((QualifierUnion[I] & Qualifiers::Const) == 0) {
4788 QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const;
4789 *NonStandardCompositeType = true;
4790 }
4791 }
4792 }
4793
4794 // Rewrap the composites as pointers or member pointers with the union CVRs.
4795 ContainingClassVector::reverse_iterator MOC
4796 = MemberOfClass.rbegin();
4797 for (QualifierVector::reverse_iterator
4798 I = QualifierUnion.rbegin(),
4799 E = QualifierUnion.rend();
4800 I != E; (void)++I, ++MOC) {
4801 Qualifiers Quals = Qualifiers::fromCVRMask(*I);
4802 if (MOC->first && MOC->second) {
4803 // Rebuild member pointer type
4804 Composite1 = Context.getMemberPointerType(
4805 Context.getQualifiedType(Composite1, Quals),
4806 MOC->first);
4807 Composite2 = Context.getMemberPointerType(
4808 Context.getQualifiedType(Composite2, Quals),
4809 MOC->second);
4810 } else {
4811 // Rebuild pointer type
4812 Composite1
4813 = Context.getPointerType(Context.getQualifiedType(Composite1, Quals));
4814 Composite2
4815 = Context.getPointerType(Context.getQualifiedType(Composite2, Quals));
4816 }
4817 }
4818
4819 // Try to convert to the first composite pointer type.
4820 InitializedEntity Entity1
4821 = InitializedEntity::InitializeTemporary(Composite1);
4822 InitializationKind Kind
4823 = InitializationKind::CreateCopy(Loc, SourceLocation());
4824 InitializationSequence E1ToC1(*this, Entity1, Kind, E1);
4825 InitializationSequence E2ToC1(*this, Entity1, Kind, E2);
4826
4827 if (E1ToC1 && E2ToC1) {
4828 // Conversion to Composite1 is viable.
4829 if (!Context.hasSameType(Composite1, Composite2)) {
4830 // Composite2 is a different type from Composite1. Check whether
4831 // Composite2 is also viable.
4832 InitializedEntity Entity2
4833 = InitializedEntity::InitializeTemporary(Composite2);
4834 InitializationSequence E1ToC2(*this, Entity2, Kind, E1);
4835 InitializationSequence E2ToC2(*this, Entity2, Kind, E2);
4836 if (E1ToC2 && E2ToC2) {
4837 // Both Composite1 and Composite2 are viable and are different;
4838 // this is an ambiguity.
4839 return QualType();
4840 }
4841 }
4842
4843 // Convert E1 to Composite1
4844 ExprResult E1Result
4845 = E1ToC1.Perform(*this, Entity1, Kind, E1);
4846 if (E1Result.isInvalid())
4847 return QualType();
4848 E1 = E1Result.getAs<Expr>();
4849
4850 // Convert E2 to Composite1
4851 ExprResult E2Result
4852 = E2ToC1.Perform(*this, Entity1, Kind, E2);
4853 if (E2Result.isInvalid())
4854 return QualType();
4855 E2 = E2Result.getAs<Expr>();
4856
4857 return Composite1;
4858 }
4859
4860 // Check whether Composite2 is viable.
4861 InitializedEntity Entity2
4862 = InitializedEntity::InitializeTemporary(Composite2);
4863 InitializationSequence E1ToC2(*this, Entity2, Kind, E1);
4864 InitializationSequence E2ToC2(*this, Entity2, Kind, E2);
4865 if (!E1ToC2 || !E2ToC2)
4866 return QualType();
4867
4868 // Convert E1 to Composite2
4869 ExprResult E1Result
4870 = E1ToC2.Perform(*this, Entity2, Kind, E1);
4871 if (E1Result.isInvalid())
4872 return QualType();
4873 E1 = E1Result.getAs<Expr>();
4874
4875 // Convert E2 to Composite2
4876 ExprResult E2Result
4877 = E2ToC2.Perform(*this, Entity2, Kind, E2);
4878 if (E2Result.isInvalid())
4879 return QualType();
4880 E2 = E2Result.getAs<Expr>();
4881
4882 return Composite2;
4883 }
4884
MaybeBindToTemporary(Expr * E)4885 ExprResult Sema::MaybeBindToTemporary(Expr *E) {
4886 if (!E)
4887 return ExprError();
4888
4889 assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?");
4890
4891 // If the result is a glvalue, we shouldn't bind it.
4892 if (!E->isRValue())
4893 return E;
4894
4895 // In ARC, calls that return a retainable type can return retained,
4896 // in which case we have to insert a consuming cast.
4897 if (getLangOpts().ObjCAutoRefCount &&
4898 E->getType()->isObjCRetainableType()) {
4899
4900 bool ReturnsRetained;
4901
4902 // For actual calls, we compute this by examining the type of the
4903 // called value.
4904 if (CallExpr *Call = dyn_cast<CallExpr>(E)) {
4905 Expr *Callee = Call->getCallee()->IgnoreParens();
4906 QualType T = Callee->getType();
4907
4908 if (T == Context.BoundMemberTy) {
4909 // Handle pointer-to-members.
4910 if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee))
4911 T = BinOp->getRHS()->getType();
4912 else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee))
4913 T = Mem->getMemberDecl()->getType();
4914 }
4915
4916 if (const PointerType *Ptr = T->getAs<PointerType>())
4917 T = Ptr->getPointeeType();
4918 else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>())
4919 T = Ptr->getPointeeType();
4920 else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>())
4921 T = MemPtr->getPointeeType();
4922
4923 const FunctionType *FTy = T->getAs<FunctionType>();
4924 assert(FTy && "call to value not of function type?");
4925 ReturnsRetained = FTy->getExtInfo().getProducesResult();
4926
4927 // ActOnStmtExpr arranges things so that StmtExprs of retainable
4928 // type always produce a +1 object.
4929 } else if (isa<StmtExpr>(E)) {
4930 ReturnsRetained = true;
4931
4932 // We hit this case with the lambda conversion-to-block optimization;
4933 // we don't want any extra casts here.
4934 } else if (isa<CastExpr>(E) &&
4935 isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) {
4936 return E;
4937
4938 // For message sends and property references, we try to find an
4939 // actual method. FIXME: we should infer retention by selector in
4940 // cases where we don't have an actual method.
4941 } else {
4942 ObjCMethodDecl *D = nullptr;
4943 if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) {
4944 D = Send->getMethodDecl();
4945 } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) {
4946 D = BoxedExpr->getBoxingMethod();
4947 } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) {
4948 D = ArrayLit->getArrayWithObjectsMethod();
4949 } else if (ObjCDictionaryLiteral *DictLit
4950 = dyn_cast<ObjCDictionaryLiteral>(E)) {
4951 D = DictLit->getDictWithObjectsMethod();
4952 }
4953
4954 ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>());
4955
4956 // Don't do reclaims on performSelector calls; despite their
4957 // return type, the invoked method doesn't necessarily actually
4958 // return an object.
4959 if (!ReturnsRetained &&
4960 D && D->getMethodFamily() == OMF_performSelector)
4961 return E;
4962 }
4963
4964 // Don't reclaim an object of Class type.
4965 if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType())
4966 return E;
4967
4968 ExprNeedsCleanups = true;
4969
4970 CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject
4971 : CK_ARCReclaimReturnedObject);
4972 return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr,
4973 VK_RValue);
4974 }
4975
4976 if (!getLangOpts().CPlusPlus)
4977 return E;
4978
4979 // Search for the base element type (cf. ASTContext::getBaseElementType) with
4980 // a fast path for the common case that the type is directly a RecordType.
4981 const Type *T = Context.getCanonicalType(E->getType().getTypePtr());
4982 const RecordType *RT = nullptr;
4983 while (!RT) {
4984 switch (T->getTypeClass()) {
4985 case Type::Record:
4986 RT = cast<RecordType>(T);
4987 break;
4988 case Type::ConstantArray:
4989 case Type::IncompleteArray:
4990 case Type::VariableArray:
4991 case Type::DependentSizedArray:
4992 T = cast<ArrayType>(T)->getElementType().getTypePtr();
4993 break;
4994 default:
4995 return E;
4996 }
4997 }
4998
4999 // That should be enough to guarantee that this type is complete, if we're
5000 // not processing a decltype expression.
5001 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
5002 if (RD->isInvalidDecl() || RD->isDependentContext())
5003 return E;
5004
5005 bool IsDecltype = ExprEvalContexts.back().IsDecltype;
5006 CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD);
5007
5008 if (Destructor) {
5009 MarkFunctionReferenced(E->getExprLoc(), Destructor);
5010 CheckDestructorAccess(E->getExprLoc(), Destructor,
5011 PDiag(diag::err_access_dtor_temp)
5012 << E->getType());
5013 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
5014 return ExprError();
5015
5016 // If destructor is trivial, we can avoid the extra copy.
5017 if (Destructor->isTrivial())
5018 return E;
5019
5020 // We need a cleanup, but we don't need to remember the temporary.
5021 ExprNeedsCleanups = true;
5022 }
5023
5024 CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor);
5025 CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E);
5026
5027 if (IsDecltype)
5028 ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind);
5029
5030 return Bind;
5031 }
5032
5033 ExprResult
MaybeCreateExprWithCleanups(ExprResult SubExpr)5034 Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) {
5035 if (SubExpr.isInvalid())
5036 return ExprError();
5037
5038 return MaybeCreateExprWithCleanups(SubExpr.get());
5039 }
5040
MaybeCreateExprWithCleanups(Expr * SubExpr)5041 Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) {
5042 assert(SubExpr && "subexpression can't be null!");
5043
5044 CleanupVarDeclMarking();
5045
5046 unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects;
5047 assert(ExprCleanupObjects.size() >= FirstCleanup);
5048 assert(ExprNeedsCleanups || ExprCleanupObjects.size() == FirstCleanup);
5049 if (!ExprNeedsCleanups)
5050 return SubExpr;
5051
5052 auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup,
5053 ExprCleanupObjects.size() - FirstCleanup);
5054
5055 Expr *E = ExprWithCleanups::Create(Context, SubExpr, Cleanups);
5056 DiscardCleanupsInEvaluationContext();
5057
5058 return E;
5059 }
5060
MaybeCreateStmtWithCleanups(Stmt * SubStmt)5061 Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) {
5062 assert(SubStmt && "sub-statement can't be null!");
5063
5064 CleanupVarDeclMarking();
5065
5066 if (!ExprNeedsCleanups)
5067 return SubStmt;
5068
5069 // FIXME: In order to attach the temporaries, wrap the statement into
5070 // a StmtExpr; currently this is only used for asm statements.
5071 // This is hacky, either create a new CXXStmtWithTemporaries statement or
5072 // a new AsmStmtWithTemporaries.
5073 CompoundStmt *CompStmt = new (Context) CompoundStmt(Context, SubStmt,
5074 SourceLocation(),
5075 SourceLocation());
5076 Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(),
5077 SourceLocation());
5078 return MaybeCreateExprWithCleanups(E);
5079 }
5080
5081 /// Process the expression contained within a decltype. For such expressions,
5082 /// certain semantic checks on temporaries are delayed until this point, and
5083 /// are omitted for the 'topmost' call in the decltype expression. If the
5084 /// topmost call bound a temporary, strip that temporary off the expression.
ActOnDecltypeExpression(Expr * E)5085 ExprResult Sema::ActOnDecltypeExpression(Expr *E) {
5086 assert(ExprEvalContexts.back().IsDecltype && "not in a decltype expression");
5087
5088 // C++11 [expr.call]p11:
5089 // If a function call is a prvalue of object type,
5090 // -- if the function call is either
5091 // -- the operand of a decltype-specifier, or
5092 // -- the right operand of a comma operator that is the operand of a
5093 // decltype-specifier,
5094 // a temporary object is not introduced for the prvalue.
5095
5096 // Recursively rebuild ParenExprs and comma expressions to strip out the
5097 // outermost CXXBindTemporaryExpr, if any.
5098 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
5099 ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr());
5100 if (SubExpr.isInvalid())
5101 return ExprError();
5102 if (SubExpr.get() == PE->getSubExpr())
5103 return E;
5104 return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get());
5105 }
5106 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
5107 if (BO->getOpcode() == BO_Comma) {
5108 ExprResult RHS = ActOnDecltypeExpression(BO->getRHS());
5109 if (RHS.isInvalid())
5110 return ExprError();
5111 if (RHS.get() == BO->getRHS())
5112 return E;
5113 return new (Context) BinaryOperator(
5114 BO->getLHS(), RHS.get(), BO_Comma, BO->getType(), BO->getValueKind(),
5115 BO->getObjectKind(), BO->getOperatorLoc(), BO->isFPContractable());
5116 }
5117 }
5118
5119 CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E);
5120 CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr())
5121 : nullptr;
5122 if (TopCall)
5123 E = TopCall;
5124 else
5125 TopBind = nullptr;
5126
5127 // Disable the special decltype handling now.
5128 ExprEvalContexts.back().IsDecltype = false;
5129
5130 // In MS mode, don't perform any extra checking of call return types within a
5131 // decltype expression.
5132 if (getLangOpts().MSVCCompat)
5133 return E;
5134
5135 // Perform the semantic checks we delayed until this point.
5136 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size();
5137 I != N; ++I) {
5138 CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I];
5139 if (Call == TopCall)
5140 continue;
5141
5142 if (CheckCallReturnType(Call->getCallReturnType(),
5143 Call->getLocStart(),
5144 Call, Call->getDirectCallee()))
5145 return ExprError();
5146 }
5147
5148 // Now all relevant types are complete, check the destructors are accessible
5149 // and non-deleted, and annotate them on the temporaries.
5150 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size();
5151 I != N; ++I) {
5152 CXXBindTemporaryExpr *Bind =
5153 ExprEvalContexts.back().DelayedDecltypeBinds[I];
5154 if (Bind == TopBind)
5155 continue;
5156
5157 CXXTemporary *Temp = Bind->getTemporary();
5158
5159 CXXRecordDecl *RD =
5160 Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
5161 CXXDestructorDecl *Destructor = LookupDestructor(RD);
5162 Temp->setDestructor(Destructor);
5163
5164 MarkFunctionReferenced(Bind->getExprLoc(), Destructor);
5165 CheckDestructorAccess(Bind->getExprLoc(), Destructor,
5166 PDiag(diag::err_access_dtor_temp)
5167 << Bind->getType());
5168 if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc()))
5169 return ExprError();
5170
5171 // We need a cleanup, but we don't need to remember the temporary.
5172 ExprNeedsCleanups = true;
5173 }
5174
5175 // Possibly strip off the top CXXBindTemporaryExpr.
5176 return E;
5177 }
5178
5179 /// Note a set of 'operator->' functions that were used for a member access.
noteOperatorArrows(Sema & S,ArrayRef<FunctionDecl * > OperatorArrows)5180 static void noteOperatorArrows(Sema &S,
5181 ArrayRef<FunctionDecl *> OperatorArrows) {
5182 unsigned SkipStart = OperatorArrows.size(), SkipCount = 0;
5183 // FIXME: Make this configurable?
5184 unsigned Limit = 9;
5185 if (OperatorArrows.size() > Limit) {
5186 // Produce Limit-1 normal notes and one 'skipping' note.
5187 SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2;
5188 SkipCount = OperatorArrows.size() - (Limit - 1);
5189 }
5190
5191 for (unsigned I = 0; I < OperatorArrows.size(); /**/) {
5192 if (I == SkipStart) {
5193 S.Diag(OperatorArrows[I]->getLocation(),
5194 diag::note_operator_arrows_suppressed)
5195 << SkipCount;
5196 I += SkipCount;
5197 } else {
5198 S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here)
5199 << OperatorArrows[I]->getCallResultType();
5200 ++I;
5201 }
5202 }
5203 }
5204
5205 ExprResult
ActOnStartCXXMemberReference(Scope * S,Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,ParsedType & ObjectType,bool & MayBePseudoDestructor)5206 Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, SourceLocation OpLoc,
5207 tok::TokenKind OpKind, ParsedType &ObjectType,
5208 bool &MayBePseudoDestructor) {
5209 // Since this might be a postfix expression, get rid of ParenListExprs.
5210 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base);
5211 if (Result.isInvalid()) return ExprError();
5212 Base = Result.get();
5213
5214 Result = CheckPlaceholderExpr(Base);
5215 if (Result.isInvalid()) return ExprError();
5216 Base = Result.get();
5217
5218 QualType BaseType = Base->getType();
5219 MayBePseudoDestructor = false;
5220 if (BaseType->isDependentType()) {
5221 // If we have a pointer to a dependent type and are using the -> operator,
5222 // the object type is the type that the pointer points to. We might still
5223 // have enough information about that type to do something useful.
5224 if (OpKind == tok::arrow)
5225 if (const PointerType *Ptr = BaseType->getAs<PointerType>())
5226 BaseType = Ptr->getPointeeType();
5227
5228 ObjectType = ParsedType::make(BaseType);
5229 MayBePseudoDestructor = true;
5230 return Base;
5231 }
5232
5233 // C++ [over.match.oper]p8:
5234 // [...] When operator->returns, the operator-> is applied to the value
5235 // returned, with the original second operand.
5236 if (OpKind == tok::arrow) {
5237 QualType StartingType = BaseType;
5238 bool NoArrowOperatorFound = false;
5239 bool FirstIteration = true;
5240 FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext);
5241 // The set of types we've considered so far.
5242 llvm::SmallPtrSet<CanQualType,8> CTypes;
5243 SmallVector<FunctionDecl*, 8> OperatorArrows;
5244 CTypes.insert(Context.getCanonicalType(BaseType));
5245
5246 while (BaseType->isRecordType()) {
5247 if (OperatorArrows.size() >= getLangOpts().ArrowDepth) {
5248 Diag(OpLoc, diag::err_operator_arrow_depth_exceeded)
5249 << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange();
5250 noteOperatorArrows(*this, OperatorArrows);
5251 Diag(OpLoc, diag::note_operator_arrow_depth)
5252 << getLangOpts().ArrowDepth;
5253 return ExprError();
5254 }
5255
5256 Result = BuildOverloadedArrowExpr(
5257 S, Base, OpLoc,
5258 // When in a template specialization and on the first loop iteration,
5259 // potentially give the default diagnostic (with the fixit in a
5260 // separate note) instead of having the error reported back to here
5261 // and giving a diagnostic with a fixit attached to the error itself.
5262 (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization())
5263 ? nullptr
5264 : &NoArrowOperatorFound);
5265 if (Result.isInvalid()) {
5266 if (NoArrowOperatorFound) {
5267 if (FirstIteration) {
5268 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
5269 << BaseType << 1 << Base->getSourceRange()
5270 << FixItHint::CreateReplacement(OpLoc, ".");
5271 OpKind = tok::period;
5272 break;
5273 }
5274 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
5275 << BaseType << Base->getSourceRange();
5276 CallExpr *CE = dyn_cast<CallExpr>(Base);
5277 if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) {
5278 Diag(CD->getLocStart(),
5279 diag::note_member_reference_arrow_from_operator_arrow);
5280 }
5281 }
5282 return ExprError();
5283 }
5284 Base = Result.get();
5285 if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base))
5286 OperatorArrows.push_back(OpCall->getDirectCallee());
5287 BaseType = Base->getType();
5288 CanQualType CBaseType = Context.getCanonicalType(BaseType);
5289 if (!CTypes.insert(CBaseType).second) {
5290 Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType;
5291 noteOperatorArrows(*this, OperatorArrows);
5292 return ExprError();
5293 }
5294 FirstIteration = false;
5295 }
5296
5297 if (OpKind == tok::arrow &&
5298 (BaseType->isPointerType() || BaseType->isObjCObjectPointerType()))
5299 BaseType = BaseType->getPointeeType();
5300 }
5301
5302 // Objective-C properties allow "." access on Objective-C pointer types,
5303 // so adjust the base type to the object type itself.
5304 if (BaseType->isObjCObjectPointerType())
5305 BaseType = BaseType->getPointeeType();
5306
5307 // C++ [basic.lookup.classref]p2:
5308 // [...] If the type of the object expression is of pointer to scalar
5309 // type, the unqualified-id is looked up in the context of the complete
5310 // postfix-expression.
5311 //
5312 // This also indicates that we could be parsing a pseudo-destructor-name.
5313 // Note that Objective-C class and object types can be pseudo-destructor
5314 // expressions or normal member (ivar or property) access expressions.
5315 if (BaseType->isObjCObjectOrInterfaceType()) {
5316 MayBePseudoDestructor = true;
5317 } else if (!BaseType->isRecordType()) {
5318 ObjectType = ParsedType();
5319 MayBePseudoDestructor = true;
5320 return Base;
5321 }
5322
5323 // The object type must be complete (or dependent), or
5324 // C++11 [expr.prim.general]p3:
5325 // Unlike the object expression in other contexts, *this is not required to
5326 // be of complete type for purposes of class member access (5.2.5) outside
5327 // the member function body.
5328 if (!BaseType->isDependentType() &&
5329 !isThisOutsideMemberFunctionBody(BaseType) &&
5330 RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access))
5331 return ExprError();
5332
5333 // C++ [basic.lookup.classref]p2:
5334 // If the id-expression in a class member access (5.2.5) is an
5335 // unqualified-id, and the type of the object expression is of a class
5336 // type C (or of pointer to a class type C), the unqualified-id is looked
5337 // up in the scope of class C. [...]
5338 ObjectType = ParsedType::make(BaseType);
5339 return Base;
5340 }
5341
DiagnoseDtorReference(SourceLocation NameLoc,Expr * MemExpr)5342 ExprResult Sema::DiagnoseDtorReference(SourceLocation NameLoc,
5343 Expr *MemExpr) {
5344 SourceLocation ExpectedLParenLoc = PP.getLocForEndOfToken(NameLoc);
5345 Diag(MemExpr->getLocStart(), diag::err_dtor_expr_without_call)
5346 << isa<CXXPseudoDestructorExpr>(MemExpr)
5347 << FixItHint::CreateInsertion(ExpectedLParenLoc, "()");
5348
5349 return ActOnCallExpr(/*Scope*/ nullptr,
5350 MemExpr,
5351 /*LPLoc*/ ExpectedLParenLoc,
5352 None,
5353 /*RPLoc*/ ExpectedLParenLoc);
5354 }
5355
CheckArrow(Sema & S,QualType & ObjectType,Expr * & Base,tok::TokenKind & OpKind,SourceLocation OpLoc)5356 static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base,
5357 tok::TokenKind& OpKind, SourceLocation OpLoc) {
5358 if (Base->hasPlaceholderType()) {
5359 ExprResult result = S.CheckPlaceholderExpr(Base);
5360 if (result.isInvalid()) return true;
5361 Base = result.get();
5362 }
5363 ObjectType = Base->getType();
5364
5365 // C++ [expr.pseudo]p2:
5366 // The left-hand side of the dot operator shall be of scalar type. The
5367 // left-hand side of the arrow operator shall be of pointer to scalar type.
5368 // This scalar type is the object type.
5369 // Note that this is rather different from the normal handling for the
5370 // arrow operator.
5371 if (OpKind == tok::arrow) {
5372 if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) {
5373 ObjectType = Ptr->getPointeeType();
5374 } else if (!Base->isTypeDependent()) {
5375 // The user wrote "p->" when she probably meant "p."; fix it.
5376 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
5377 << ObjectType << true
5378 << FixItHint::CreateReplacement(OpLoc, ".");
5379 if (S.isSFINAEContext())
5380 return true;
5381
5382 OpKind = tok::period;
5383 }
5384 }
5385
5386 return false;
5387 }
5388
BuildPseudoDestructorExpr(Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,const CXXScopeSpec & SS,TypeSourceInfo * ScopeTypeInfo,SourceLocation CCLoc,SourceLocation TildeLoc,PseudoDestructorTypeStorage Destructed,bool HasTrailingLParen)5389 ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base,
5390 SourceLocation OpLoc,
5391 tok::TokenKind OpKind,
5392 const CXXScopeSpec &SS,
5393 TypeSourceInfo *ScopeTypeInfo,
5394 SourceLocation CCLoc,
5395 SourceLocation TildeLoc,
5396 PseudoDestructorTypeStorage Destructed,
5397 bool HasTrailingLParen) {
5398 TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo();
5399
5400 QualType ObjectType;
5401 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
5402 return ExprError();
5403
5404 if (!ObjectType->isDependentType() && !ObjectType->isScalarType() &&
5405 !ObjectType->isVectorType()) {
5406 if (getLangOpts().MSVCCompat && ObjectType->isVoidType())
5407 Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange();
5408 else {
5409 Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar)
5410 << ObjectType << Base->getSourceRange();
5411 return ExprError();
5412 }
5413 }
5414
5415 // C++ [expr.pseudo]p2:
5416 // [...] The cv-unqualified versions of the object type and of the type
5417 // designated by the pseudo-destructor-name shall be the same type.
5418 if (DestructedTypeInfo) {
5419 QualType DestructedType = DestructedTypeInfo->getType();
5420 SourceLocation DestructedTypeStart
5421 = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin();
5422 if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) {
5423 if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) {
5424 Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch)
5425 << ObjectType << DestructedType << Base->getSourceRange()
5426 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange();
5427
5428 // Recover by setting the destructed type to the object type.
5429 DestructedType = ObjectType;
5430 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType,
5431 DestructedTypeStart);
5432 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
5433 } else if (DestructedType.getObjCLifetime() !=
5434 ObjectType.getObjCLifetime()) {
5435
5436 if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) {
5437 // Okay: just pretend that the user provided the correctly-qualified
5438 // type.
5439 } else {
5440 Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals)
5441 << ObjectType << DestructedType << Base->getSourceRange()
5442 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange();
5443 }
5444
5445 // Recover by setting the destructed type to the object type.
5446 DestructedType = ObjectType;
5447 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType,
5448 DestructedTypeStart);
5449 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
5450 }
5451 }
5452 }
5453
5454 // C++ [expr.pseudo]p2:
5455 // [...] Furthermore, the two type-names in a pseudo-destructor-name of the
5456 // form
5457 //
5458 // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name
5459 //
5460 // shall designate the same scalar type.
5461 if (ScopeTypeInfo) {
5462 QualType ScopeType = ScopeTypeInfo->getType();
5463 if (!ScopeType->isDependentType() && !ObjectType->isDependentType() &&
5464 !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) {
5465
5466 Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(),
5467 diag::err_pseudo_dtor_type_mismatch)
5468 << ObjectType << ScopeType << Base->getSourceRange()
5469 << ScopeTypeInfo->getTypeLoc().getLocalSourceRange();
5470
5471 ScopeType = QualType();
5472 ScopeTypeInfo = nullptr;
5473 }
5474 }
5475
5476 Expr *Result
5477 = new (Context) CXXPseudoDestructorExpr(Context, Base,
5478 OpKind == tok::arrow, OpLoc,
5479 SS.getWithLocInContext(Context),
5480 ScopeTypeInfo,
5481 CCLoc,
5482 TildeLoc,
5483 Destructed);
5484
5485 if (HasTrailingLParen)
5486 return Result;
5487
5488 return DiagnoseDtorReference(Destructed.getLocation(), Result);
5489 }
5490
ActOnPseudoDestructorExpr(Scope * S,Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,CXXScopeSpec & SS,UnqualifiedId & FirstTypeName,SourceLocation CCLoc,SourceLocation TildeLoc,UnqualifiedId & SecondTypeName,bool HasTrailingLParen)5491 ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
5492 SourceLocation OpLoc,
5493 tok::TokenKind OpKind,
5494 CXXScopeSpec &SS,
5495 UnqualifiedId &FirstTypeName,
5496 SourceLocation CCLoc,
5497 SourceLocation TildeLoc,
5498 UnqualifiedId &SecondTypeName,
5499 bool HasTrailingLParen) {
5500 assert((FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId ||
5501 FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) &&
5502 "Invalid first type name in pseudo-destructor");
5503 assert((SecondTypeName.getKind() == UnqualifiedId::IK_TemplateId ||
5504 SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) &&
5505 "Invalid second type name in pseudo-destructor");
5506
5507 QualType ObjectType;
5508 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
5509 return ExprError();
5510
5511 // Compute the object type that we should use for name lookup purposes. Only
5512 // record types and dependent types matter.
5513 ParsedType ObjectTypePtrForLookup;
5514 if (!SS.isSet()) {
5515 if (ObjectType->isRecordType())
5516 ObjectTypePtrForLookup = ParsedType::make(ObjectType);
5517 else if (ObjectType->isDependentType())
5518 ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy);
5519 }
5520
5521 // Convert the name of the type being destructed (following the ~) into a
5522 // type (with source-location information).
5523 QualType DestructedType;
5524 TypeSourceInfo *DestructedTypeInfo = nullptr;
5525 PseudoDestructorTypeStorage Destructed;
5526 if (SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) {
5527 ParsedType T = getTypeName(*SecondTypeName.Identifier,
5528 SecondTypeName.StartLocation,
5529 S, &SS, true, false, ObjectTypePtrForLookup);
5530 if (!T &&
5531 ((SS.isSet() && !computeDeclContext(SS, false)) ||
5532 (!SS.isSet() && ObjectType->isDependentType()))) {
5533 // The name of the type being destroyed is a dependent name, and we
5534 // couldn't find anything useful in scope. Just store the identifier and
5535 // it's location, and we'll perform (qualified) name lookup again at
5536 // template instantiation time.
5537 Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier,
5538 SecondTypeName.StartLocation);
5539 } else if (!T) {
5540 Diag(SecondTypeName.StartLocation,
5541 diag::err_pseudo_dtor_destructor_non_type)
5542 << SecondTypeName.Identifier << ObjectType;
5543 if (isSFINAEContext())
5544 return ExprError();
5545
5546 // Recover by assuming we had the right type all along.
5547 DestructedType = ObjectType;
5548 } else
5549 DestructedType = GetTypeFromParser(T, &DestructedTypeInfo);
5550 } else {
5551 // Resolve the template-id to a type.
5552 TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId;
5553 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
5554 TemplateId->NumArgs);
5555 TypeResult T = ActOnTemplateIdType(TemplateId->SS,
5556 TemplateId->TemplateKWLoc,
5557 TemplateId->Template,
5558 TemplateId->TemplateNameLoc,
5559 TemplateId->LAngleLoc,
5560 TemplateArgsPtr,
5561 TemplateId->RAngleLoc);
5562 if (T.isInvalid() || !T.get()) {
5563 // Recover by assuming we had the right type all along.
5564 DestructedType = ObjectType;
5565 } else
5566 DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo);
5567 }
5568
5569 // If we've performed some kind of recovery, (re-)build the type source
5570 // information.
5571 if (!DestructedType.isNull()) {
5572 if (!DestructedTypeInfo)
5573 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType,
5574 SecondTypeName.StartLocation);
5575 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
5576 }
5577
5578 // Convert the name of the scope type (the type prior to '::') into a type.
5579 TypeSourceInfo *ScopeTypeInfo = nullptr;
5580 QualType ScopeType;
5581 if (FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId ||
5582 FirstTypeName.Identifier) {
5583 if (FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) {
5584 ParsedType T = getTypeName(*FirstTypeName.Identifier,
5585 FirstTypeName.StartLocation,
5586 S, &SS, true, false, ObjectTypePtrForLookup);
5587 if (!T) {
5588 Diag(FirstTypeName.StartLocation,
5589 diag::err_pseudo_dtor_destructor_non_type)
5590 << FirstTypeName.Identifier << ObjectType;
5591
5592 if (isSFINAEContext())
5593 return ExprError();
5594
5595 // Just drop this type. It's unnecessary anyway.
5596 ScopeType = QualType();
5597 } else
5598 ScopeType = GetTypeFromParser(T, &ScopeTypeInfo);
5599 } else {
5600 // Resolve the template-id to a type.
5601 TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId;
5602 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
5603 TemplateId->NumArgs);
5604 TypeResult T = ActOnTemplateIdType(TemplateId->SS,
5605 TemplateId->TemplateKWLoc,
5606 TemplateId->Template,
5607 TemplateId->TemplateNameLoc,
5608 TemplateId->LAngleLoc,
5609 TemplateArgsPtr,
5610 TemplateId->RAngleLoc);
5611 if (T.isInvalid() || !T.get()) {
5612 // Recover by dropping this type.
5613 ScopeType = QualType();
5614 } else
5615 ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo);
5616 }
5617 }
5618
5619 if (!ScopeType.isNull() && !ScopeTypeInfo)
5620 ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType,
5621 FirstTypeName.StartLocation);
5622
5623
5624 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS,
5625 ScopeTypeInfo, CCLoc, TildeLoc,
5626 Destructed, HasTrailingLParen);
5627 }
5628
ActOnPseudoDestructorExpr(Scope * S,Expr * Base,SourceLocation OpLoc,tok::TokenKind OpKind,SourceLocation TildeLoc,const DeclSpec & DS,bool HasTrailingLParen)5629 ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
5630 SourceLocation OpLoc,
5631 tok::TokenKind OpKind,
5632 SourceLocation TildeLoc,
5633 const DeclSpec& DS,
5634 bool HasTrailingLParen) {
5635 QualType ObjectType;
5636 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
5637 return ExprError();
5638
5639 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(),
5640 false);
5641
5642 TypeLocBuilder TLB;
5643 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
5644 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
5645 TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T);
5646 PseudoDestructorTypeStorage Destructed(DestructedTypeInfo);
5647
5648 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(),
5649 nullptr, SourceLocation(), TildeLoc,
5650 Destructed, HasTrailingLParen);
5651 }
5652
BuildCXXMemberCallExpr(Expr * E,NamedDecl * FoundDecl,CXXConversionDecl * Method,bool HadMultipleCandidates)5653 ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
5654 CXXConversionDecl *Method,
5655 bool HadMultipleCandidates) {
5656 if (Method->getParent()->isLambda() &&
5657 Method->getConversionType()->isBlockPointerType()) {
5658 // This is a lambda coversion to block pointer; check if the argument
5659 // is a LambdaExpr.
5660 Expr *SubE = E;
5661 CastExpr *CE = dyn_cast<CastExpr>(SubE);
5662 if (CE && CE->getCastKind() == CK_NoOp)
5663 SubE = CE->getSubExpr();
5664 SubE = SubE->IgnoreParens();
5665 if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE))
5666 SubE = BE->getSubExpr();
5667 if (isa<LambdaExpr>(SubE)) {
5668 // For the conversion to block pointer on a lambda expression, we
5669 // construct a special BlockLiteral instead; this doesn't really make
5670 // a difference in ARC, but outside of ARC the resulting block literal
5671 // follows the normal lifetime rules for block literals instead of being
5672 // autoreleased.
5673 DiagnosticErrorTrap Trap(Diags);
5674 ExprResult Exp = BuildBlockForLambdaConversion(E->getExprLoc(),
5675 E->getExprLoc(),
5676 Method, E);
5677 if (Exp.isInvalid())
5678 Diag(E->getExprLoc(), diag::note_lambda_to_block_conv);
5679 return Exp;
5680 }
5681 }
5682
5683 ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr,
5684 FoundDecl, Method);
5685 if (Exp.isInvalid())
5686 return true;
5687
5688 MemberExpr *ME =
5689 new (Context) MemberExpr(Exp.get(), /*IsArrow=*/false, Method,
5690 SourceLocation(), Context.BoundMemberTy,
5691 VK_RValue, OK_Ordinary);
5692 if (HadMultipleCandidates)
5693 ME->setHadMultipleCandidates(true);
5694 MarkMemberReferenced(ME);
5695
5696 QualType ResultType = Method->getReturnType();
5697 ExprValueKind VK = Expr::getValueKindForType(ResultType);
5698 ResultType = ResultType.getNonLValueExprType(Context);
5699
5700 CXXMemberCallExpr *CE =
5701 new (Context) CXXMemberCallExpr(Context, ME, None, ResultType, VK,
5702 Exp.get()->getLocEnd());
5703 return CE;
5704 }
5705
BuildCXXNoexceptExpr(SourceLocation KeyLoc,Expr * Operand,SourceLocation RParen)5706 ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
5707 SourceLocation RParen) {
5708 // If the operand is an unresolved lookup expression, the expression is ill-
5709 // formed per [over.over]p1, because overloaded function names cannot be used
5710 // without arguments except in explicit contexts.
5711 ExprResult R = CheckPlaceholderExpr(Operand);
5712 if (R.isInvalid())
5713 return R;
5714
5715 // The operand may have been modified when checking the placeholder type.
5716 Operand = R.get();
5717
5718 if (ActiveTemplateInstantiations.empty() &&
5719 Operand->HasSideEffects(Context, false)) {
5720 // The expression operand for noexcept is in an unevaluated expression
5721 // context, so side effects could result in unintended consequences.
5722 Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context);
5723 }
5724
5725 CanThrowResult CanThrow = canThrow(Operand);
5726 return new (Context)
5727 CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen);
5728 }
5729
ActOnNoexceptExpr(SourceLocation KeyLoc,SourceLocation,Expr * Operand,SourceLocation RParen)5730 ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation,
5731 Expr *Operand, SourceLocation RParen) {
5732 return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen);
5733 }
5734
IsSpecialDiscardedValue(Expr * E)5735 static bool IsSpecialDiscardedValue(Expr *E) {
5736 // In C++11, discarded-value expressions of a certain form are special,
5737 // according to [expr]p10:
5738 // The lvalue-to-rvalue conversion (4.1) is applied only if the
5739 // expression is an lvalue of volatile-qualified type and it has
5740 // one of the following forms:
5741 E = E->IgnoreParens();
5742
5743 // - id-expression (5.1.1),
5744 if (isa<DeclRefExpr>(E))
5745 return true;
5746
5747 // - subscripting (5.2.1),
5748 if (isa<ArraySubscriptExpr>(E))
5749 return true;
5750
5751 // - class member access (5.2.5),
5752 if (isa<MemberExpr>(E))
5753 return true;
5754
5755 // - indirection (5.3.1),
5756 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E))
5757 if (UO->getOpcode() == UO_Deref)
5758 return true;
5759
5760 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
5761 // - pointer-to-member operation (5.5),
5762 if (BO->isPtrMemOp())
5763 return true;
5764
5765 // - comma expression (5.18) where the right operand is one of the above.
5766 if (BO->getOpcode() == BO_Comma)
5767 return IsSpecialDiscardedValue(BO->getRHS());
5768 }
5769
5770 // - conditional expression (5.16) where both the second and the third
5771 // operands are one of the above, or
5772 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E))
5773 return IsSpecialDiscardedValue(CO->getTrueExpr()) &&
5774 IsSpecialDiscardedValue(CO->getFalseExpr());
5775 // The related edge case of "*x ?: *x".
5776 if (BinaryConditionalOperator *BCO =
5777 dyn_cast<BinaryConditionalOperator>(E)) {
5778 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(BCO->getTrueExpr()))
5779 return IsSpecialDiscardedValue(OVE->getSourceExpr()) &&
5780 IsSpecialDiscardedValue(BCO->getFalseExpr());
5781 }
5782
5783 // Objective-C++ extensions to the rule.
5784 if (isa<PseudoObjectExpr>(E) || isa<ObjCIvarRefExpr>(E))
5785 return true;
5786
5787 return false;
5788 }
5789
5790 /// Perform the conversions required for an expression used in a
5791 /// context that ignores the result.
IgnoredValueConversions(Expr * E)5792 ExprResult Sema::IgnoredValueConversions(Expr *E) {
5793 if (E->hasPlaceholderType()) {
5794 ExprResult result = CheckPlaceholderExpr(E);
5795 if (result.isInvalid()) return E;
5796 E = result.get();
5797 }
5798
5799 // C99 6.3.2.1:
5800 // [Except in specific positions,] an lvalue that does not have
5801 // array type is converted to the value stored in the
5802 // designated object (and is no longer an lvalue).
5803 if (E->isRValue()) {
5804 // In C, function designators (i.e. expressions of function type)
5805 // are r-values, but we still want to do function-to-pointer decay
5806 // on them. This is both technically correct and convenient for
5807 // some clients.
5808 if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType())
5809 return DefaultFunctionArrayConversion(E);
5810
5811 return E;
5812 }
5813
5814 if (getLangOpts().CPlusPlus) {
5815 // The C++11 standard defines the notion of a discarded-value expression;
5816 // normally, we don't need to do anything to handle it, but if it is a
5817 // volatile lvalue with a special form, we perform an lvalue-to-rvalue
5818 // conversion.
5819 if (getLangOpts().CPlusPlus11 && E->isGLValue() &&
5820 E->getType().isVolatileQualified() &&
5821 IsSpecialDiscardedValue(E)) {
5822 ExprResult Res = DefaultLvalueConversion(E);
5823 if (Res.isInvalid())
5824 return E;
5825 E = Res.get();
5826 }
5827 return E;
5828 }
5829
5830 // GCC seems to also exclude expressions of incomplete enum type.
5831 if (const EnumType *T = E->getType()->getAs<EnumType>()) {
5832 if (!T->getDecl()->isComplete()) {
5833 // FIXME: stupid workaround for a codegen bug!
5834 E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get();
5835 return E;
5836 }
5837 }
5838
5839 ExprResult Res = DefaultFunctionArrayLvalueConversion(E);
5840 if (Res.isInvalid())
5841 return E;
5842 E = Res.get();
5843
5844 if (!E->getType()->isVoidType())
5845 RequireCompleteType(E->getExprLoc(), E->getType(),
5846 diag::err_incomplete_type);
5847 return E;
5848 }
5849
5850 // If we can unambiguously determine whether Var can never be used
5851 // in a constant expression, return true.
5852 // - if the variable and its initializer are non-dependent, then
5853 // we can unambiguously check if the variable is a constant expression.
5854 // - if the initializer is not value dependent - we can determine whether
5855 // it can be used to initialize a constant expression. If Init can not
5856 // be used to initialize a constant expression we conclude that Var can
5857 // never be a constant expression.
5858 // - FXIME: if the initializer is dependent, we can still do some analysis and
5859 // identify certain cases unambiguously as non-const by using a Visitor:
5860 // - such as those that involve odr-use of a ParmVarDecl, involve a new
5861 // delete, lambda-expr, dynamic-cast, reinterpret-cast etc...
VariableCanNeverBeAConstantExpression(VarDecl * Var,ASTContext & Context)5862 static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var,
5863 ASTContext &Context) {
5864 if (isa<ParmVarDecl>(Var)) return true;
5865 const VarDecl *DefVD = nullptr;
5866
5867 // If there is no initializer - this can not be a constant expression.
5868 if (!Var->getAnyInitializer(DefVD)) return true;
5869 assert(DefVD);
5870 if (DefVD->isWeak()) return false;
5871 EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt();
5872
5873 Expr *Init = cast<Expr>(Eval->Value);
5874
5875 if (Var->getType()->isDependentType() || Init->isValueDependent()) {
5876 // FIXME: Teach the constant evaluator to deal with the non-dependent parts
5877 // of value-dependent expressions, and use it here to determine whether the
5878 // initializer is a potential constant expression.
5879 return false;
5880 }
5881
5882 return !IsVariableAConstantExpression(Var, Context);
5883 }
5884
5885 /// \brief Check if the current lambda has any potential captures
5886 /// that must be captured by any of its enclosing lambdas that are ready to
5887 /// capture. If there is a lambda that can capture a nested
5888 /// potential-capture, go ahead and do so. Also, check to see if any
5889 /// variables are uncaptureable or do not involve an odr-use so do not
5890 /// need to be captured.
5891
CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(Expr * const FE,LambdaScopeInfo * const CurrentLSI,Sema & S)5892 static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
5893 Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) {
5894
5895 assert(!S.isUnevaluatedContext());
5896 assert(S.CurContext->isDependentContext());
5897 assert(CurrentLSI->CallOperator == S.CurContext &&
5898 "The current call operator must be synchronized with Sema's CurContext");
5899
5900 const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent();
5901
5902 ArrayRef<const FunctionScopeInfo *> FunctionScopesArrayRef(
5903 S.FunctionScopes.data(), S.FunctionScopes.size());
5904
5905 // All the potentially captureable variables in the current nested
5906 // lambda (within a generic outer lambda), must be captured by an
5907 // outer lambda that is enclosed within a non-dependent context.
5908 const unsigned NumPotentialCaptures =
5909 CurrentLSI->getNumPotentialVariableCaptures();
5910 for (unsigned I = 0; I != NumPotentialCaptures; ++I) {
5911 Expr *VarExpr = nullptr;
5912 VarDecl *Var = nullptr;
5913 CurrentLSI->getPotentialVariableCapture(I, Var, VarExpr);
5914 // If the variable is clearly identified as non-odr-used and the full
5915 // expression is not instantiation dependent, only then do we not
5916 // need to check enclosing lambda's for speculative captures.
5917 // For e.g.:
5918 // Even though 'x' is not odr-used, it should be captured.
5919 // int test() {
5920 // const int x = 10;
5921 // auto L = [=](auto a) {
5922 // (void) +x + a;
5923 // };
5924 // }
5925 if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) &&
5926 !IsFullExprInstantiationDependent)
5927 continue;
5928
5929 // If we have a capture-capable lambda for the variable, go ahead and
5930 // capture the variable in that lambda (and all its enclosing lambdas).
5931 if (const Optional<unsigned> Index =
5932 getStackIndexOfNearestEnclosingCaptureCapableLambda(
5933 FunctionScopesArrayRef, Var, S)) {
5934 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
5935 MarkVarDeclODRUsed(Var, VarExpr->getExprLoc(), S,
5936 &FunctionScopeIndexOfCapturableLambda);
5937 }
5938 const bool IsVarNeverAConstantExpression =
5939 VariableCanNeverBeAConstantExpression(Var, S.Context);
5940 if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) {
5941 // This full expression is not instantiation dependent or the variable
5942 // can not be used in a constant expression - which means
5943 // this variable must be odr-used here, so diagnose a
5944 // capture violation early, if the variable is un-captureable.
5945 // This is purely for diagnosing errors early. Otherwise, this
5946 // error would get diagnosed when the lambda becomes capture ready.
5947 QualType CaptureType, DeclRefType;
5948 SourceLocation ExprLoc = VarExpr->getExprLoc();
5949 if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
5950 /*EllipsisLoc*/ SourceLocation(),
5951 /*BuildAndDiagnose*/false, CaptureType,
5952 DeclRefType, nullptr)) {
5953 // We will never be able to capture this variable, and we need
5954 // to be able to in any and all instantiations, so diagnose it.
5955 S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
5956 /*EllipsisLoc*/ SourceLocation(),
5957 /*BuildAndDiagnose*/true, CaptureType,
5958 DeclRefType, nullptr);
5959 }
5960 }
5961 }
5962
5963 // Check if 'this' needs to be captured.
5964 if (CurrentLSI->hasPotentialThisCapture()) {
5965 // If we have a capture-capable lambda for 'this', go ahead and capture
5966 // 'this' in that lambda (and all its enclosing lambdas).
5967 if (const Optional<unsigned> Index =
5968 getStackIndexOfNearestEnclosingCaptureCapableLambda(
5969 FunctionScopesArrayRef, /*0 is 'this'*/ nullptr, S)) {
5970 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
5971 S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation,
5972 /*Explicit*/ false, /*BuildAndDiagnose*/ true,
5973 &FunctionScopeIndexOfCapturableLambda);
5974 }
5975 }
5976
5977 // Reset all the potential captures at the end of each full-expression.
5978 CurrentLSI->clearPotentialCaptures();
5979 }
5980
attemptRecovery(Sema & SemaRef,const TypoCorrectionConsumer & Consumer,TypoCorrection TC)5981 static ExprResult attemptRecovery(Sema &SemaRef,
5982 const TypoCorrectionConsumer &Consumer,
5983 TypoCorrection TC) {
5984 LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(),
5985 Consumer.getLookupResult().getLookupKind());
5986 const CXXScopeSpec *SS = Consumer.getSS();
5987 CXXScopeSpec NewSS;
5988
5989 // Use an approprate CXXScopeSpec for building the expr.
5990 if (auto *NNS = TC.getCorrectionSpecifier())
5991 NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange());
5992 else if (SS && !TC.WillReplaceSpecifier())
5993 NewSS = *SS;
5994
5995 if (auto *ND = TC.getCorrectionDecl()) {
5996 R.setLookupName(ND->getDeclName());
5997 R.addDecl(ND);
5998 if (ND->isCXXClassMember()) {
5999 // Figure out the correct naming class to add to the LookupResult.
6000 CXXRecordDecl *Record = nullptr;
6001 if (auto *NNS = TC.getCorrectionSpecifier())
6002 Record = NNS->getAsType()->getAsCXXRecordDecl();
6003 if (!Record)
6004 Record =
6005 dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext());
6006 if (Record)
6007 R.setNamingClass(Record);
6008
6009 // Detect and handle the case where the decl might be an implicit
6010 // member.
6011 bool MightBeImplicitMember;
6012 if (!Consumer.isAddressOfOperand())
6013 MightBeImplicitMember = true;
6014 else if (!NewSS.isEmpty())
6015 MightBeImplicitMember = false;
6016 else if (R.isOverloadedResult())
6017 MightBeImplicitMember = false;
6018 else if (R.isUnresolvableResult())
6019 MightBeImplicitMember = true;
6020 else
6021 MightBeImplicitMember = isa<FieldDecl>(ND) ||
6022 isa<IndirectFieldDecl>(ND) ||
6023 isa<MSPropertyDecl>(ND);
6024
6025 if (MightBeImplicitMember)
6026 return SemaRef.BuildPossibleImplicitMemberExpr(
6027 NewSS, /*TemplateKWLoc*/ SourceLocation(), R,
6028 /*TemplateArgs*/ nullptr);
6029 } else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) {
6030 return SemaRef.LookupInObjCMethod(R, Consumer.getScope(),
6031 Ivar->getIdentifier());
6032 }
6033 }
6034
6035 return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false,
6036 /*AcceptInvalidDecl*/ true);
6037 }
6038
6039 namespace {
6040 class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> {
6041 llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs;
6042
6043 public:
FindTypoExprs(llvm::SmallSetVector<TypoExpr *,2> & TypoExprs)6044 explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs)
6045 : TypoExprs(TypoExprs) {}
VisitTypoExpr(TypoExpr * TE)6046 bool VisitTypoExpr(TypoExpr *TE) {
6047 TypoExprs.insert(TE);
6048 return true;
6049 }
6050 };
6051
6052 class TransformTypos : public TreeTransform<TransformTypos> {
6053 typedef TreeTransform<TransformTypos> BaseTransform;
6054
6055 llvm::function_ref<ExprResult(Expr *)> ExprFilter;
6056 llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs;
6057 llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache;
6058 llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution;
6059
6060 /// \brief Emit diagnostics for all of the TypoExprs encountered.
6061 /// If the TypoExprs were successfully corrected, then the diagnostics should
6062 /// suggest the corrections. Otherwise the diagnostics will not suggest
6063 /// anything (having been passed an empty TypoCorrection).
EmitAllDiagnostics()6064 void EmitAllDiagnostics() {
6065 for (auto E : TypoExprs) {
6066 TypoExpr *TE = cast<TypoExpr>(E);
6067 auto &State = SemaRef.getTypoExprState(TE);
6068 if (State.DiagHandler) {
6069 TypoCorrection TC = State.Consumer->getCurrentCorrection();
6070 ExprResult Replacement = TransformCache[TE];
6071
6072 // Extract the NamedDecl from the transformed TypoExpr and add it to the
6073 // TypoCorrection, replacing the existing decls. This ensures the right
6074 // NamedDecl is used in diagnostics e.g. in the case where overload
6075 // resolution was used to select one from several possible decls that
6076 // had been stored in the TypoCorrection.
6077 if (auto *ND = getDeclFromExpr(
6078 Replacement.isInvalid() ? nullptr : Replacement.get()))
6079 TC.setCorrectionDecl(ND);
6080
6081 State.DiagHandler(TC);
6082 }
6083 SemaRef.clearDelayedTypo(TE);
6084 }
6085 }
6086
6087 /// \brief If corrections for the first TypoExpr have been exhausted for a
6088 /// given combination of the other TypoExprs, retry those corrections against
6089 /// the next combination of substitutions for the other TypoExprs by advancing
6090 /// to the next potential correction of the second TypoExpr. For the second
6091 /// and subsequent TypoExprs, if its stream of corrections has been exhausted,
6092 /// the stream is reset and the next TypoExpr's stream is advanced by one (a
6093 /// TypoExpr's correction stream is advanced by removing the TypoExpr from the
6094 /// TransformCache). Returns true if there is still any untried combinations
6095 /// of corrections.
CheckAndAdvanceTypoExprCorrectionStreams()6096 bool CheckAndAdvanceTypoExprCorrectionStreams() {
6097 for (auto TE : TypoExprs) {
6098 auto &State = SemaRef.getTypoExprState(TE);
6099 TransformCache.erase(TE);
6100 if (!State.Consumer->finished())
6101 return true;
6102 State.Consumer->resetCorrectionStream();
6103 }
6104 return false;
6105 }
6106
getDeclFromExpr(Expr * E)6107 NamedDecl *getDeclFromExpr(Expr *E) {
6108 if (auto *OE = dyn_cast_or_null<OverloadExpr>(E))
6109 E = OverloadResolution[OE];
6110
6111 if (!E)
6112 return nullptr;
6113 if (auto *DRE = dyn_cast<DeclRefExpr>(E))
6114 return DRE->getDecl();
6115 if (auto *ME = dyn_cast<MemberExpr>(E))
6116 return ME->getMemberDecl();
6117 // FIXME: Add any other expr types that could be be seen by the delayed typo
6118 // correction TreeTransform for which the corresponding TypoCorrection could
6119 // contain multiple decls.
6120 return nullptr;
6121 }
6122
TryTransform(Expr * E)6123 ExprResult TryTransform(Expr *E) {
6124 Sema::SFINAETrap Trap(SemaRef);
6125 ExprResult Res = TransformExpr(E);
6126 if (Trap.hasErrorOccurred() || Res.isInvalid())
6127 return ExprError();
6128
6129 return ExprFilter(Res.get());
6130 }
6131
6132 public:
TransformTypos(Sema & SemaRef,llvm::function_ref<ExprResult (Expr *)> Filter)6133 TransformTypos(Sema &SemaRef, llvm::function_ref<ExprResult(Expr *)> Filter)
6134 : BaseTransform(SemaRef), ExprFilter(Filter) {}
6135
RebuildCallExpr(Expr * Callee,SourceLocation LParenLoc,MultiExprArg Args,SourceLocation RParenLoc,Expr * ExecConfig=nullptr)6136 ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc,
6137 MultiExprArg Args,
6138 SourceLocation RParenLoc,
6139 Expr *ExecConfig = nullptr) {
6140 auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args,
6141 RParenLoc, ExecConfig);
6142 if (auto *OE = dyn_cast<OverloadExpr>(Callee)) {
6143 if (Result.isUsable()) {
6144 Expr *ResultCall = Result.get();
6145 if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall))
6146 ResultCall = BE->getSubExpr();
6147 if (auto *CE = dyn_cast<CallExpr>(ResultCall))
6148 OverloadResolution[OE] = CE->getCallee();
6149 }
6150 }
6151 return Result;
6152 }
6153
TransformLambdaExpr(LambdaExpr * E)6154 ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); }
6155
Transform(Expr * E)6156 ExprResult Transform(Expr *E) {
6157 ExprResult Res;
6158 while (true) {
6159 Res = TryTransform(E);
6160
6161 // Exit if either the transform was valid or if there were no TypoExprs
6162 // to transform that still have any untried correction candidates..
6163 if (!Res.isInvalid() ||
6164 !CheckAndAdvanceTypoExprCorrectionStreams())
6165 break;
6166 }
6167
6168 // Ensure none of the TypoExprs have multiple typo correction candidates
6169 // with the same edit length that pass all the checks and filters.
6170 // TODO: Properly handle various permutations of possible corrections when
6171 // there is more than one potentially ambiguous typo correction.
6172 while (!AmbiguousTypoExprs.empty()) {
6173 auto TE = AmbiguousTypoExprs.back();
6174 auto Cached = TransformCache[TE];
6175 auto &State = SemaRef.getTypoExprState(TE);
6176 State.Consumer->saveCurrentPosition();
6177 TransformCache.erase(TE);
6178 if (!TryTransform(E).isInvalid()) {
6179 State.Consumer->resetCorrectionStream();
6180 TransformCache.erase(TE);
6181 Res = ExprError();
6182 break;
6183 }
6184 AmbiguousTypoExprs.remove(TE);
6185 State.Consumer->restoreSavedPosition();
6186 TransformCache[TE] = Cached;
6187 }
6188
6189 // Ensure that all of the TypoExprs within the current Expr have been found.
6190 if (!Res.isUsable())
6191 FindTypoExprs(TypoExprs).TraverseStmt(E);
6192
6193 EmitAllDiagnostics();
6194
6195 return Res;
6196 }
6197
TransformTypoExpr(TypoExpr * E)6198 ExprResult TransformTypoExpr(TypoExpr *E) {
6199 // If the TypoExpr hasn't been seen before, record it. Otherwise, return the
6200 // cached transformation result if there is one and the TypoExpr isn't the
6201 // first one that was encountered.
6202 auto &CacheEntry = TransformCache[E];
6203 if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) {
6204 return CacheEntry;
6205 }
6206
6207 auto &State = SemaRef.getTypoExprState(E);
6208 assert(State.Consumer && "Cannot transform a cleared TypoExpr");
6209
6210 // For the first TypoExpr and an uncached TypoExpr, find the next likely
6211 // typo correction and return it.
6212 while (TypoCorrection TC = State.Consumer->getNextCorrection()) {
6213 ExprResult NE = State.RecoveryHandler ?
6214 State.RecoveryHandler(SemaRef, E, TC) :
6215 attemptRecovery(SemaRef, *State.Consumer, TC);
6216 if (!NE.isInvalid()) {
6217 // Check whether there may be a second viable correction with the same
6218 // edit distance; if so, remember this TypoExpr may have an ambiguous
6219 // correction so it can be more thoroughly vetted later.
6220 TypoCorrection Next;
6221 if ((Next = State.Consumer->peekNextCorrection()) &&
6222 Next.getEditDistance(false) == TC.getEditDistance(false)) {
6223 AmbiguousTypoExprs.insert(E);
6224 } else {
6225 AmbiguousTypoExprs.remove(E);
6226 }
6227 assert(!NE.isUnset() &&
6228 "Typo was transformed into a valid-but-null ExprResult");
6229 return CacheEntry = NE;
6230 }
6231 }
6232 return CacheEntry = ExprError();
6233 }
6234 };
6235 }
6236
CorrectDelayedTyposInExpr(Expr * E,llvm::function_ref<ExprResult (Expr *)> Filter)6237 ExprResult Sema::CorrectDelayedTyposInExpr(
6238 Expr *E, llvm::function_ref<ExprResult(Expr *)> Filter) {
6239 // If the current evaluation context indicates there are uncorrected typos
6240 // and the current expression isn't guaranteed to not have typos, try to
6241 // resolve any TypoExpr nodes that might be in the expression.
6242 if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos &&
6243 (E->isTypeDependent() || E->isValueDependent() ||
6244 E->isInstantiationDependent())) {
6245 auto TyposInContext = ExprEvalContexts.back().NumTypos;
6246 assert(TyposInContext < ~0U && "Recursive call of CorrectDelayedTyposInExpr");
6247 ExprEvalContexts.back().NumTypos = ~0U;
6248 auto TyposResolved = DelayedTypos.size();
6249 auto Result = TransformTypos(*this, Filter).Transform(E);
6250 ExprEvalContexts.back().NumTypos = TyposInContext;
6251 TyposResolved -= DelayedTypos.size();
6252 if (Result.isInvalid() || Result.get() != E) {
6253 ExprEvalContexts.back().NumTypos -= TyposResolved;
6254 return Result;
6255 }
6256 assert(TyposResolved == 0 && "Corrected typo but got same Expr back?");
6257 }
6258 return E;
6259 }
6260
ActOnFinishFullExpr(Expr * FE,SourceLocation CC,bool DiscardedValue,bool IsConstexpr,bool IsLambdaInitCaptureInitializer)6261 ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC,
6262 bool DiscardedValue,
6263 bool IsConstexpr,
6264 bool IsLambdaInitCaptureInitializer) {
6265 ExprResult FullExpr = FE;
6266
6267 if (!FullExpr.get())
6268 return ExprError();
6269
6270 // If we are an init-expression in a lambdas init-capture, we should not
6271 // diagnose an unexpanded pack now (will be diagnosed once lambda-expr
6272 // containing full-expression is done).
6273 // template<class ... Ts> void test(Ts ... t) {
6274 // test([&a(t)]() { <-- (t) is an init-expr that shouldn't be diagnosed now.
6275 // return a;
6276 // }() ...);
6277 // }
6278 // FIXME: This is a hack. It would be better if we pushed the lambda scope
6279 // when we parse the lambda introducer, and teach capturing (but not
6280 // unexpanded pack detection) to walk over LambdaScopeInfos which don't have a
6281 // corresponding class yet (that is, have LambdaScopeInfo either represent a
6282 // lambda where we've entered the introducer but not the body, or represent a
6283 // lambda where we've entered the body, depending on where the
6284 // parser/instantiation has got to).
6285 if (!IsLambdaInitCaptureInitializer &&
6286 DiagnoseUnexpandedParameterPack(FullExpr.get()))
6287 return ExprError();
6288
6289 // Top-level expressions default to 'id' when we're in a debugger.
6290 if (DiscardedValue && getLangOpts().DebuggerCastResultToId &&
6291 FullExpr.get()->getType() == Context.UnknownAnyTy) {
6292 FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType());
6293 if (FullExpr.isInvalid())
6294 return ExprError();
6295 }
6296
6297 if (DiscardedValue) {
6298 FullExpr = CheckPlaceholderExpr(FullExpr.get());
6299 if (FullExpr.isInvalid())
6300 return ExprError();
6301
6302 FullExpr = IgnoredValueConversions(FullExpr.get());
6303 if (FullExpr.isInvalid())
6304 return ExprError();
6305 }
6306
6307 FullExpr = CorrectDelayedTyposInExpr(FullExpr.get());
6308 if (FullExpr.isInvalid())
6309 return ExprError();
6310
6311 CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr);
6312
6313 // At the end of this full expression (which could be a deeply nested
6314 // lambda), if there is a potential capture within the nested lambda,
6315 // have the outer capture-able lambda try and capture it.
6316 // Consider the following code:
6317 // void f(int, int);
6318 // void f(const int&, double);
6319 // void foo() {
6320 // const int x = 10, y = 20;
6321 // auto L = [=](auto a) {
6322 // auto M = [=](auto b) {
6323 // f(x, b); <-- requires x to be captured by L and M
6324 // f(y, a); <-- requires y to be captured by L, but not all Ms
6325 // };
6326 // };
6327 // }
6328
6329 // FIXME: Also consider what happens for something like this that involves
6330 // the gnu-extension statement-expressions or even lambda-init-captures:
6331 // void f() {
6332 // const int n = 0;
6333 // auto L = [&](auto a) {
6334 // +n + ({ 0; a; });
6335 // };
6336 // }
6337 //
6338 // Here, we see +n, and then the full-expression 0; ends, so we don't
6339 // capture n (and instead remove it from our list of potential captures),
6340 // and then the full-expression +n + ({ 0; }); ends, but it's too late
6341 // for us to see that we need to capture n after all.
6342
6343 LambdaScopeInfo *const CurrentLSI = getCurLambda();
6344 // FIXME: PR 17877 showed that getCurLambda() can return a valid pointer
6345 // even if CurContext is not a lambda call operator. Refer to that Bug Report
6346 // for an example of the code that might cause this asynchrony.
6347 // By ensuring we are in the context of a lambda's call operator
6348 // we can fix the bug (we only need to check whether we need to capture
6349 // if we are within a lambda's body); but per the comments in that
6350 // PR, a proper fix would entail :
6351 // "Alternative suggestion:
6352 // - Add to Sema an integer holding the smallest (outermost) scope
6353 // index that we are *lexically* within, and save/restore/set to
6354 // FunctionScopes.size() in InstantiatingTemplate's
6355 // constructor/destructor.
6356 // - Teach the handful of places that iterate over FunctionScopes to
6357 // stop at the outermost enclosing lexical scope."
6358 const bool IsInLambdaDeclContext = isLambdaCallOperator(CurContext);
6359 if (IsInLambdaDeclContext && CurrentLSI &&
6360 CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid())
6361 CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI,
6362 *this);
6363 return MaybeCreateExprWithCleanups(FullExpr);
6364 }
6365
ActOnFinishFullStmt(Stmt * FullStmt)6366 StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) {
6367 if (!FullStmt) return StmtError();
6368
6369 return MaybeCreateStmtWithCleanups(FullStmt);
6370 }
6371
6372 Sema::IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope * S,CXXScopeSpec & SS,const DeclarationNameInfo & TargetNameInfo)6373 Sema::CheckMicrosoftIfExistsSymbol(Scope *S,
6374 CXXScopeSpec &SS,
6375 const DeclarationNameInfo &TargetNameInfo) {
6376 DeclarationName TargetName = TargetNameInfo.getName();
6377 if (!TargetName)
6378 return IER_DoesNotExist;
6379
6380 // If the name itself is dependent, then the result is dependent.
6381 if (TargetName.isDependentName())
6382 return IER_Dependent;
6383
6384 // Do the redeclaration lookup in the current scope.
6385 LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName,
6386 Sema::NotForRedeclaration);
6387 LookupParsedName(R, S, &SS);
6388 R.suppressDiagnostics();
6389
6390 switch (R.getResultKind()) {
6391 case LookupResult::Found:
6392 case LookupResult::FoundOverloaded:
6393 case LookupResult::FoundUnresolvedValue:
6394 case LookupResult::Ambiguous:
6395 return IER_Exists;
6396
6397 case LookupResult::NotFound:
6398 return IER_DoesNotExist;
6399
6400 case LookupResult::NotFoundInCurrentInstantiation:
6401 return IER_Dependent;
6402 }
6403
6404 llvm_unreachable("Invalid LookupResult Kind!");
6405 }
6406
6407 Sema::IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope * S,SourceLocation KeywordLoc,bool IsIfExists,CXXScopeSpec & SS,UnqualifiedId & Name)6408 Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc,
6409 bool IsIfExists, CXXScopeSpec &SS,
6410 UnqualifiedId &Name) {
6411 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
6412
6413 // Check for unexpanded parameter packs.
6414 SmallVector<UnexpandedParameterPack, 4> Unexpanded;
6415 collectUnexpandedParameterPacks(SS, Unexpanded);
6416 collectUnexpandedParameterPacks(TargetNameInfo, Unexpanded);
6417 if (!Unexpanded.empty()) {
6418 DiagnoseUnexpandedParameterPacks(KeywordLoc,
6419 IsIfExists? UPPC_IfExists
6420 : UPPC_IfNotExists,
6421 Unexpanded);
6422 return IER_Error;
6423 }
6424
6425 return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo);
6426 }
6427