clang  15.0.0git
SemaExprCXX.cpp
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1 //===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// Implements semantic analysis for C++ expressions.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "TreeTransform.h"
15 #include "TypeLocBuilder.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/ASTLambda.h"
19 #include "clang/AST/CharUnits.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "clang/AST/ExprCXX.h"
22 #include "clang/AST/ExprObjC.h"
24 #include "clang/AST/TypeLoc.h"
28 #include "clang/Basic/TargetInfo.h"
29 #include "clang/Basic/TypeTraits.h"
30 #include "clang/Lex/Preprocessor.h"
31 #include "clang/Sema/DeclSpec.h"
33 #include "clang/Sema/Lookup.h"
35 #include "clang/Sema/Scope.h"
36 #include "clang/Sema/ScopeInfo.h"
38 #include "clang/Sema/SemaLambda.h"
39 #include "clang/Sema/Template.h"
41 #include "llvm/ADT/APInt.h"
42 #include "llvm/ADT/STLExtras.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/TypeSize.h"
45 using namespace clang;
46 using namespace sema;
47 
48 /// Handle the result of the special case name lookup for inheriting
49 /// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as
50 /// constructor names in member using declarations, even if 'X' is not the
51 /// name of the corresponding type.
53  SourceLocation NameLoc,
54  IdentifierInfo &Name) {
55  NestedNameSpecifier *NNS = SS.getScopeRep();
56 
57  // Convert the nested-name-specifier into a type.
58  QualType Type;
59  switch (NNS->getKind()) {
62  Type = QualType(NNS->getAsType(), 0);
63  break;
64 
66  // Strip off the last layer of the nested-name-specifier and build a
67  // typename type for it.
68  assert(NNS->getAsIdentifier() == &Name && "not a constructor name");
69  Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(),
70  NNS->getAsIdentifier());
71  break;
72 
77  llvm_unreachable("Nested name specifier is not a type for inheriting ctor");
78  }
79 
80  // This reference to the type is located entirely at the location of the
81  // final identifier in the qualified-id.
82  return CreateParsedType(Type,
83  Context.getTrivialTypeSourceInfo(Type, NameLoc));
84 }
85 
87  SourceLocation NameLoc,
88  Scope *S, CXXScopeSpec &SS,
89  bool EnteringContext) {
90  CXXRecordDecl *CurClass = getCurrentClass(S, &SS);
91  assert(CurClass && &II == CurClass->getIdentifier() &&
92  "not a constructor name");
93 
94  // When naming a constructor as a member of a dependent context (eg, in a
95  // friend declaration or an inherited constructor declaration), form an
96  // unresolved "typename" type.
97  if (CurClass->isDependentContext() && !EnteringContext && SS.getScopeRep()) {
98  QualType T = Context.getDependentNameType(ETK_None, SS.getScopeRep(), &II);
99  return ParsedType::make(T);
100  }
101 
102  if (SS.isNotEmpty() && RequireCompleteDeclContext(SS, CurClass))
103  return ParsedType();
104 
105  // Find the injected-class-name declaration. Note that we make no attempt to
106  // diagnose cases where the injected-class-name is shadowed: the only
107  // declaration that can validly shadow the injected-class-name is a
108  // non-static data member, and if the class contains both a non-static data
109  // member and a constructor then it is ill-formed (we check that in
110  // CheckCompletedCXXClass).
111  CXXRecordDecl *InjectedClassName = nullptr;
112  for (NamedDecl *ND : CurClass->lookup(&II)) {
113  auto *RD = dyn_cast<CXXRecordDecl>(ND);
114  if (RD && RD->isInjectedClassName()) {
115  InjectedClassName = RD;
116  break;
117  }
118  }
119  if (!InjectedClassName) {
120  if (!CurClass->isInvalidDecl()) {
121  // FIXME: RequireCompleteDeclContext doesn't check dependent contexts
122  // properly. Work around it here for now.
124  diag::err_incomplete_nested_name_spec) << CurClass << SS.getRange();
125  }
126  return ParsedType();
127  }
128 
129  QualType T = Context.getTypeDeclType(InjectedClassName);
130  DiagnoseUseOfDecl(InjectedClassName, NameLoc);
131  MarkAnyDeclReferenced(NameLoc, InjectedClassName, /*OdrUse=*/false);
132 
133  return ParsedType::make(T);
134 }
135 
137  IdentifierInfo &II,
138  SourceLocation NameLoc,
139  Scope *S, CXXScopeSpec &SS,
140  ParsedType ObjectTypePtr,
141  bool EnteringContext) {
142  // Determine where to perform name lookup.
143 
144  // FIXME: This area of the standard is very messy, and the current
145  // wording is rather unclear about which scopes we search for the
146  // destructor name; see core issues 399 and 555. Issue 399 in
147  // particular shows where the current description of destructor name
148  // lookup is completely out of line with existing practice, e.g.,
149  // this appears to be ill-formed:
150  //
151  // namespace N {
152  // template <typename T> struct S {
153  // ~S();
154  // };
155  // }
156  //
157  // void f(N::S<int>* s) {
158  // s->N::S<int>::~S();
159  // }
160  //
161  // See also PR6358 and PR6359.
162  //
163  // For now, we accept all the cases in which the name given could plausibly
164  // be interpreted as a correct destructor name, issuing off-by-default
165  // extension diagnostics on the cases that don't strictly conform to the
166  // C++20 rules. This basically means we always consider looking in the
167  // nested-name-specifier prefix, the complete nested-name-specifier, and
168  // the scope, and accept if we find the expected type in any of the three
169  // places.
170 
171  if (SS.isInvalid())
172  return nullptr;
173 
174  // Whether we've failed with a diagnostic already.
175  bool Failed = false;
176 
179 
180  // If we have an object type, it's because we are in a
181  // pseudo-destructor-expression or a member access expression, and
182  // we know what type we're looking for.
183  QualType SearchType =
184  ObjectTypePtr ? GetTypeFromParser(ObjectTypePtr) : QualType();
185 
186  auto CheckLookupResult = [&](LookupResult &Found) -> ParsedType {
187  auto IsAcceptableResult = [&](NamedDecl *D) -> bool {
188  auto *Type = dyn_cast<TypeDecl>(D->getUnderlyingDecl());
189  if (!Type)
190  return false;
191 
192  if (SearchType.isNull() || SearchType->isDependentType())
193  return true;
194 
195  QualType T = Context.getTypeDeclType(Type);
196  return Context.hasSameUnqualifiedType(T, SearchType);
197  };
198 
199  unsigned NumAcceptableResults = 0;
200  for (NamedDecl *D : Found) {
201  if (IsAcceptableResult(D))
202  ++NumAcceptableResults;
203 
204  // Don't list a class twice in the lookup failure diagnostic if it's
205  // found by both its injected-class-name and by the name in the enclosing
206  // scope.
207  if (auto *RD = dyn_cast<CXXRecordDecl>(D))
208  if (RD->isInjectedClassName())
209  D = cast<NamedDecl>(RD->getParent());
210 
211  if (FoundDeclSet.insert(D).second)
212  FoundDecls.push_back(D);
213  }
214 
215  // As an extension, attempt to "fix" an ambiguity by erasing all non-type
216  // results, and all non-matching results if we have a search type. It's not
217  // clear what the right behavior is if destructor lookup hits an ambiguity,
218  // but other compilers do generally accept at least some kinds of
219  // ambiguity.
220  if (Found.isAmbiguous() && NumAcceptableResults == 1) {
221  Diag(NameLoc, diag::ext_dtor_name_ambiguous);
222  LookupResult::Filter F = Found.makeFilter();
223  while (F.hasNext()) {
224  NamedDecl *D = F.next();
225  if (auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl()))
226  Diag(D->getLocation(), diag::note_destructor_type_here)
227  << Context.getTypeDeclType(TD);
228  else
229  Diag(D->getLocation(), diag::note_destructor_nontype_here);
230 
231  if (!IsAcceptableResult(D))
232  F.erase();
233  }
234  F.done();
235  }
236 
237  if (Found.isAmbiguous())
238  Failed = true;
239 
240  if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
241  if (IsAcceptableResult(Type)) {
242  QualType T = Context.getTypeDeclType(Type);
243  MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
244  return CreateParsedType(T,
245  Context.getTrivialTypeSourceInfo(T, NameLoc));
246  }
247  }
248 
249  return nullptr;
250  };
251 
252  bool IsDependent = false;
253 
254  auto LookupInObjectType = [&]() -> ParsedType {
255  if (Failed || SearchType.isNull())
256  return nullptr;
257 
258  IsDependent |= SearchType->isDependentType();
259 
260  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
261  DeclContext *LookupCtx = computeDeclContext(SearchType);
262  if (!LookupCtx)
263  return nullptr;
264  LookupQualifiedName(Found, LookupCtx);
265  return CheckLookupResult(Found);
266  };
267 
268  auto LookupInNestedNameSpec = [&](CXXScopeSpec &LookupSS) -> ParsedType {
269  if (Failed)
270  return nullptr;
271 
272  IsDependent |= isDependentScopeSpecifier(LookupSS);
273  DeclContext *LookupCtx = computeDeclContext(LookupSS, EnteringContext);
274  if (!LookupCtx)
275  return nullptr;
276 
277  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
278  if (RequireCompleteDeclContext(LookupSS, LookupCtx)) {
279  Failed = true;
280  return nullptr;
281  }
282  LookupQualifiedName(Found, LookupCtx);
283  return CheckLookupResult(Found);
284  };
285 
286  auto LookupInScope = [&]() -> ParsedType {
287  if (Failed || !S)
288  return nullptr;
289 
290  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
291  LookupName(Found, S);
292  return CheckLookupResult(Found);
293  };
294 
295  // C++2a [basic.lookup.qual]p6:
296  // In a qualified-id of the form
297  //
298  // nested-name-specifier[opt] type-name :: ~ type-name
299  //
300  // the second type-name is looked up in the same scope as the first.
301  //
302  // We interpret this as meaning that if you do a dual-scope lookup for the
303  // first name, you also do a dual-scope lookup for the second name, per
304  // C++ [basic.lookup.classref]p4:
305  //
306  // If the id-expression in a class member access is a qualified-id of the
307  // form
308  //
309  // class-name-or-namespace-name :: ...
310  //
311  // the class-name-or-namespace-name following the . or -> is first looked
312  // up in the class of the object expression and the name, if found, is used.
313  // Otherwise, it is looked up in the context of the entire
314  // postfix-expression.
315  //
316  // This looks in the same scopes as for an unqualified destructor name:
317  //
318  // C++ [basic.lookup.classref]p3:
319  // If the unqualified-id is ~ type-name, the type-name is looked up
320  // in the context of the entire postfix-expression. If the type T
321  // of the object expression is of a class type C, the type-name is
322  // also looked up in the scope of class C. At least one of the
323  // lookups shall find a name that refers to cv T.
324  //
325  // FIXME: The intent is unclear here. Should type-name::~type-name look in
326  // the scope anyway if it finds a non-matching name declared in the class?
327  // If both lookups succeed and find a dependent result, which result should
328  // we retain? (Same question for p->~type-name().)
329 
330  if (NestedNameSpecifier *Prefix =
331  SS.isSet() ? SS.getScopeRep()->getPrefix() : nullptr) {
332  // This is
333  //
334  // nested-name-specifier type-name :: ~ type-name
335  //
336  // Look for the second type-name in the nested-name-specifier.
337  CXXScopeSpec PrefixSS;
338  PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
339  if (ParsedType T = LookupInNestedNameSpec(PrefixSS))
340  return T;
341  } else {
342  // This is one of
343  //
344  // type-name :: ~ type-name
345  // ~ type-name
346  //
347  // Look in the scope and (if any) the object type.
348  if (ParsedType T = LookupInScope())
349  return T;
350  if (ParsedType T = LookupInObjectType())
351  return T;
352  }
353 
354  if (Failed)
355  return nullptr;
356 
357  if (IsDependent) {
358  // We didn't find our type, but that's OK: it's dependent anyway.
359 
360  // FIXME: What if we have no nested-name-specifier?
361  QualType T = CheckTypenameType(ETK_None, SourceLocation(),
362  SS.getWithLocInContext(Context),
363  II, NameLoc);
364  return ParsedType::make(T);
365  }
366 
367  // The remaining cases are all non-standard extensions imitating the behavior
368  // of various other compilers.
369  unsigned NumNonExtensionDecls = FoundDecls.size();
370 
371  if (SS.isSet()) {
372  // For compatibility with older broken C++ rules and existing code,
373  //
374  // nested-name-specifier :: ~ type-name
375  //
376  // also looks for type-name within the nested-name-specifier.
377  if (ParsedType T = LookupInNestedNameSpec(SS)) {
378  Diag(SS.getEndLoc(), diag::ext_dtor_named_in_wrong_scope)
379  << SS.getRange()
381  ("::" + II.getName()).str());
382  return T;
383  }
384 
385  // For compatibility with other compilers and older versions of Clang,
386  //
387  // nested-name-specifier type-name :: ~ type-name
388  //
389  // also looks for type-name in the scope. Unfortunately, we can't
390  // reasonably apply this fallback for dependent nested-name-specifiers.
391  if (SS.getScopeRep()->getPrefix()) {
392  if (ParsedType T = LookupInScope()) {
393  Diag(SS.getEndLoc(), diag::ext_qualified_dtor_named_in_lexical_scope)
395  Diag(FoundDecls.back()->getLocation(), diag::note_destructor_type_here)
396  << GetTypeFromParser(T);
397  return T;
398  }
399  }
400  }
401 
402  // We didn't find anything matching; tell the user what we did find (if
403  // anything).
404 
405  // Don't tell the user about declarations we shouldn't have found.
406  FoundDecls.resize(NumNonExtensionDecls);
407 
408  // List types before non-types.
409  std::stable_sort(FoundDecls.begin(), FoundDecls.end(),
410  [](NamedDecl *A, NamedDecl *B) {
411  return isa<TypeDecl>(A->getUnderlyingDecl()) >
412  isa<TypeDecl>(B->getUnderlyingDecl());
413  });
414 
415  // Suggest a fixit to properly name the destroyed type.
416  auto MakeFixItHint = [&]{
417  const CXXRecordDecl *Destroyed = nullptr;
418  // FIXME: If we have a scope specifier, suggest its last component?
419  if (!SearchType.isNull())
420  Destroyed = SearchType->getAsCXXRecordDecl();
421  else if (S)
422  Destroyed = dyn_cast_or_null<CXXRecordDecl>(S->getEntity());
423  if (Destroyed)
425  Destroyed->getNameAsString());
426  return FixItHint();
427  };
428 
429  if (FoundDecls.empty()) {
430  // FIXME: Attempt typo-correction?
431  Diag(NameLoc, diag::err_undeclared_destructor_name)
432  << &II << MakeFixItHint();
433  } else if (!SearchType.isNull() && FoundDecls.size() == 1) {
434  if (auto *TD = dyn_cast<TypeDecl>(FoundDecls[0]->getUnderlyingDecl())) {
435  assert(!SearchType.isNull() &&
436  "should only reject a type result if we have a search type");
437  QualType T = Context.getTypeDeclType(TD);
438  Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
439  << T << SearchType << MakeFixItHint();
440  } else {
441  Diag(NameLoc, diag::err_destructor_expr_nontype)
442  << &II << MakeFixItHint();
443  }
444  } else {
445  Diag(NameLoc, SearchType.isNull() ? diag::err_destructor_name_nontype
446  : diag::err_destructor_expr_mismatch)
447  << &II << SearchType << MakeFixItHint();
448  }
449 
450  for (NamedDecl *FoundD : FoundDecls) {
451  if (auto *TD = dyn_cast<TypeDecl>(FoundD->getUnderlyingDecl()))
452  Diag(FoundD->getLocation(), diag::note_destructor_type_here)
453  << Context.getTypeDeclType(TD);
454  else
455  Diag(FoundD->getLocation(), diag::note_destructor_nontype_here)
456  << FoundD;
457  }
458 
459  return nullptr;
460 }
461 
463  ParsedType ObjectType) {
465  return nullptr;
466 
468  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
469  return nullptr;
470  }
471 
472  assert(DS.getTypeSpecType() == DeclSpec::TST_decltype &&
473  "unexpected type in getDestructorType");
474  QualType T = BuildDecltypeType(DS.getRepAsExpr());
475 
476  // If we know the type of the object, check that the correct destructor
477  // type was named now; we can give better diagnostics this way.
478  QualType SearchType = GetTypeFromParser(ObjectType);
479  if (!SearchType.isNull() && !SearchType->isDependentType() &&
480  !Context.hasSameUnqualifiedType(T, SearchType)) {
481  Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
482  << T << SearchType;
483  return nullptr;
484  }
485 
486  return ParsedType::make(T);
487 }
488 
490  const UnqualifiedId &Name, bool IsUDSuffix) {
491  assert(Name.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId);
492  if (!IsUDSuffix) {
493  // [over.literal] p8
494  //
495  // double operator""_Bq(long double); // OK: not a reserved identifier
496  // double operator"" _Bq(long double); // ill-formed, no diagnostic required
497  IdentifierInfo *II = Name.Identifier;
498  ReservedIdentifierStatus Status = II->isReserved(PP.getLangOpts());
499  SourceLocation Loc = Name.getEndLoc();
500  if (isReservedInAllContexts(Status) &&
501  !PP.getSourceManager().isInSystemHeader(Loc)) {
502  Diag(Loc, diag::warn_reserved_extern_symbol)
503  << II << static_cast<int>(Status)
505  Name.getSourceRange(),
506  (StringRef("operator\"\"") + II->getName()).str());
507  }
508  }
509 
510  if (!SS.isValid())
511  return false;
512 
513  switch (SS.getScopeRep()->getKind()) {
517  // Per C++11 [over.literal]p2, literal operators can only be declared at
518  // namespace scope. Therefore, this unqualified-id cannot name anything.
519  // Reject it early, because we have no AST representation for this in the
520  // case where the scope is dependent.
521  Diag(Name.getBeginLoc(), diag::err_literal_operator_id_outside_namespace)
522  << SS.getScopeRep();
523  return true;
524 
529  return false;
530  }
531 
532  llvm_unreachable("unknown nested name specifier kind");
533 }
534 
535 /// Build a C++ typeid expression with a type operand.
537  SourceLocation TypeidLoc,
538  TypeSourceInfo *Operand,
539  SourceLocation RParenLoc) {
540  // C++ [expr.typeid]p4:
541  // The top-level cv-qualifiers of the lvalue expression or the type-id
542  // that is the operand of typeid are always ignored.
543  // If the type of the type-id is a class type or a reference to a class
544  // type, the class shall be completely-defined.
545  Qualifiers Quals;
546  QualType T
547  = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
548  Quals);
549  if (T->getAs<RecordType>() &&
550  RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
551  return ExprError();
552 
553  if (T->isVariablyModifiedType())
554  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);
555 
556  if (CheckQualifiedFunctionForTypeId(T, TypeidLoc))
557  return ExprError();
558 
559  return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
560  SourceRange(TypeidLoc, RParenLoc));
561 }
562 
563 /// Build a C++ typeid expression with an expression operand.
565  SourceLocation TypeidLoc,
566  Expr *E,
567  SourceLocation RParenLoc) {
568  bool WasEvaluated = false;
569  if (E && !E->isTypeDependent()) {
570  if (E->hasPlaceholderType()) {
571  ExprResult result = CheckPlaceholderExpr(E);
572  if (result.isInvalid()) return ExprError();
573  E = result.get();
574  }
575 
576  QualType T = E->getType();
577  if (const RecordType *RecordT = T->getAs<RecordType>()) {
578  CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
579  // C++ [expr.typeid]p3:
580  // [...] If the type of the expression is a class type, the class
581  // shall be completely-defined.
582  if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
583  return ExprError();
584 
585  // C++ [expr.typeid]p3:
586  // When typeid is applied to an expression other than an glvalue of a
587  // polymorphic class type [...] [the] expression is an unevaluated
588  // operand. [...]
589  if (RecordD->isPolymorphic() && E->isGLValue()) {
590  if (isUnevaluatedContext()) {
591  // The operand was processed in unevaluated context, switch the
592  // context and recheck the subexpression.
593  ExprResult Result = TransformToPotentiallyEvaluated(E);
594  if (Result.isInvalid())
595  return ExprError();
596  E = Result.get();
597  }
598 
599  // We require a vtable to query the type at run time.
600  MarkVTableUsed(TypeidLoc, RecordD);
601  WasEvaluated = true;
602  }
603  }
604 
605  ExprResult Result = CheckUnevaluatedOperand(E);
606  if (Result.isInvalid())
607  return ExprError();
608  E = Result.get();
609 
610  // C++ [expr.typeid]p4:
611  // [...] If the type of the type-id is a reference to a possibly
612  // cv-qualified type, the result of the typeid expression refers to a
613  // std::type_info object representing the cv-unqualified referenced
614  // type.
615  Qualifiers Quals;
616  QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
617  if (!Context.hasSameType(T, UnqualT)) {
618  T = UnqualT;
619  E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
620  }
621  }
622 
623  if (E->getType()->isVariablyModifiedType())
624  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
625  << E->getType());
626  else if (!inTemplateInstantiation() &&
627  E->HasSideEffects(Context, WasEvaluated)) {
628  // The expression operand for typeid is in an unevaluated expression
629  // context, so side effects could result in unintended consequences.
630  Diag(E->getExprLoc(), WasEvaluated
631  ? diag::warn_side_effects_typeid
632  : diag::warn_side_effects_unevaluated_context);
633  }
634 
635  return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
636  SourceRange(TypeidLoc, RParenLoc));
637 }
638 
639 /// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
642  bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
643  // typeid is not supported in OpenCL.
644  if (getLangOpts().OpenCLCPlusPlus) {
645  return ExprError(Diag(OpLoc, diag::err_openclcxx_not_supported)
646  << "typeid");
647  }
648 
649  // Find the std::type_info type.
650  if (!getStdNamespace())
651  return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
652 
653  if (!CXXTypeInfoDecl) {
654  IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
655  LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
656  LookupQualifiedName(R, getStdNamespace());
657  CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
658  // Microsoft's typeinfo doesn't have type_info in std but in the global
659  // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
660  if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
661  LookupQualifiedName(R, Context.getTranslationUnitDecl());
662  CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
663  }
664  if (!CXXTypeInfoDecl)
665  return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
666  }
667 
668  if (!getLangOpts().RTTI) {
669  return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
670  }
671 
672  QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);
673 
674  if (isType) {
675  // The operand is a type; handle it as such.
676  TypeSourceInfo *TInfo = nullptr;
677  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
678  &TInfo);
679  if (T.isNull())
680  return ExprError();
681 
682  if (!TInfo)
683  TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
684 
685  return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
686  }
687 
688  // The operand is an expression.
689  ExprResult Result =
690  BuildCXXTypeId(TypeInfoType, OpLoc, (Expr *)TyOrExpr, RParenLoc);
691 
692  if (!getLangOpts().RTTIData && !Result.isInvalid())
693  if (auto *CTE = dyn_cast<CXXTypeidExpr>(Result.get()))
694  if (CTE->isPotentiallyEvaluated() && !CTE->isMostDerived(Context))
695  Diag(OpLoc, diag::warn_no_typeid_with_rtti_disabled)
696  << (getDiagnostics().getDiagnosticOptions().getFormat() ==
698  return Result;
699 }
700 
701 /// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to
702 /// a single GUID.
703 static void
706  // Optionally remove one level of pointer, reference or array indirection.
707  const Type *Ty = QT.getTypePtr();
708  if (QT->isPointerType() || QT->isReferenceType())
709  Ty = QT->getPointeeType().getTypePtr();
710  else if (QT->isArrayType())
711  Ty = Ty->getBaseElementTypeUnsafe();
712 
713  const auto *TD = Ty->getAsTagDecl();
714  if (!TD)
715  return;
716 
717  if (const auto *Uuid = TD->getMostRecentDecl()->getAttr<UuidAttr>()) {
718  UuidAttrs.insert(Uuid);
719  return;
720  }
721 
722  // __uuidof can grab UUIDs from template arguments.
723  if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(TD)) {
724  const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
725  for (const TemplateArgument &TA : TAL.asArray()) {
726  const UuidAttr *UuidForTA = nullptr;
727  if (TA.getKind() == TemplateArgument::Type)
728  getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs);
729  else if (TA.getKind() == TemplateArgument::Declaration)
730  getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs);
731 
732  if (UuidForTA)
733  UuidAttrs.insert(UuidForTA);
734  }
735  }
736 }
737 
738 /// Build a Microsoft __uuidof expression with a type operand.
740  SourceLocation TypeidLoc,
741  TypeSourceInfo *Operand,
742  SourceLocation RParenLoc) {
743  MSGuidDecl *Guid = nullptr;
744  if (!Operand->getType()->isDependentType()) {
746  getUuidAttrOfType(*this, Operand->getType(), UuidAttrs);
747  if (UuidAttrs.empty())
748  return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
749  if (UuidAttrs.size() > 1)
750  return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
751  Guid = UuidAttrs.back()->getGuidDecl();
752  }
753 
754  return new (Context)
755  CXXUuidofExpr(Type, Operand, Guid, SourceRange(TypeidLoc, RParenLoc));
756 }
757 
758 /// Build a Microsoft __uuidof expression with an expression operand.
760  Expr *E, SourceLocation RParenLoc) {
761  MSGuidDecl *Guid = nullptr;
762  if (!E->getType()->isDependentType()) {
764  // A null pointer results in {00000000-0000-0000-0000-000000000000}.
765  Guid = Context.getMSGuidDecl(MSGuidDecl::Parts{});
766  } else {
768  getUuidAttrOfType(*this, E->getType(), UuidAttrs);
769  if (UuidAttrs.empty())
770  return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
771  if (UuidAttrs.size() > 1)
772  return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
773  Guid = UuidAttrs.back()->getGuidDecl();
774  }
775  }
776 
777  return new (Context)
778  CXXUuidofExpr(Type, E, Guid, SourceRange(TypeidLoc, RParenLoc));
779 }
780 
781 /// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
784  bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
785  QualType GuidType = Context.getMSGuidType();
786  GuidType.addConst();
787 
788  if (isType) {
789  // The operand is a type; handle it as such.
790  TypeSourceInfo *TInfo = nullptr;
791  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
792  &TInfo);
793  if (T.isNull())
794  return ExprError();
795 
796  if (!TInfo)
797  TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
798 
799  return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
800  }
801 
802  // The operand is an expression.
803  return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
804 }
805 
806 /// ActOnCXXBoolLiteral - Parse {true,false} literals.
809  assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
810  "Unknown C++ Boolean value!");
811  return new (Context)
812  CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
813 }
814 
815 /// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
818  return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
819 }
820 
821 /// ActOnCXXThrow - Parse throw expressions.
824  bool IsThrownVarInScope = false;
825  if (Ex) {
826  // C++0x [class.copymove]p31:
827  // When certain criteria are met, an implementation is allowed to omit the
828  // copy/move construction of a class object [...]
829  //
830  // - in a throw-expression, when the operand is the name of a
831  // non-volatile automatic object (other than a function or catch-
832  // clause parameter) whose scope does not extend beyond the end of the
833  // innermost enclosing try-block (if there is one), the copy/move
834  // operation from the operand to the exception object (15.1) can be
835  // omitted by constructing the automatic object directly into the
836  // exception object
837  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
838  if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
839  if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
840  for( ; S; S = S->getParent()) {
841  if (S->isDeclScope(Var)) {
842  IsThrownVarInScope = true;
843  break;
844  }
845 
846  if (S->getFlags() &
850  break;
851  }
852  }
853  }
854  }
855 
856  return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
857 }
858 
860  bool IsThrownVarInScope) {
861  // Don't report an error if 'throw' is used in system headers.
862  if (!getLangOpts().CXXExceptions &&
863  !getSourceManager().isInSystemHeader(OpLoc) && !getLangOpts().CUDA) {
864  // Delay error emission for the OpenMP device code.
865  targetDiag(OpLoc, diag::err_exceptions_disabled) << "throw";
866  }
867 
868  // Exceptions aren't allowed in CUDA device code.
869  if (getLangOpts().CUDA)
870  CUDADiagIfDeviceCode(OpLoc, diag::err_cuda_device_exceptions)
871  << "throw" << CurrentCUDATarget();
872 
873  if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
874  Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";
875 
876  if (Ex && !Ex->isTypeDependent()) {
877  // Initialize the exception result. This implicitly weeds out
878  // abstract types or types with inaccessible copy constructors.
879 
880  // C++0x [class.copymove]p31:
881  // When certain criteria are met, an implementation is allowed to omit the
882  // copy/move construction of a class object [...]
883  //
884  // - in a throw-expression, when the operand is the name of a
885  // non-volatile automatic object (other than a function or
886  // catch-clause
887  // parameter) whose scope does not extend beyond the end of the
888  // innermost enclosing try-block (if there is one), the copy/move
889  // operation from the operand to the exception object (15.1) can be
890  // omitted by constructing the automatic object directly into the
891  // exception object
892  NamedReturnInfo NRInfo =
893  IsThrownVarInScope ? getNamedReturnInfo(Ex) : NamedReturnInfo();
894 
895  QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
896  if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
897  return ExprError();
898 
899  InitializedEntity Entity =
900  InitializedEntity::InitializeException(OpLoc, ExceptionObjectTy);
901  ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRInfo, Ex);
902  if (Res.isInvalid())
903  return ExprError();
904  Ex = Res.get();
905  }
906 
907  // PPC MMA non-pointer types are not allowed as throw expr types.
908  if (Ex && Context.getTargetInfo().getTriple().isPPC64())
909  CheckPPCMMAType(Ex->getType(), Ex->getBeginLoc());
910 
911  return new (Context)
912  CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
913 }
914 
915 static void
917  llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen,
918  llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases,
919  llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen,
920  bool ParentIsPublic) {
921  for (const CXXBaseSpecifier &BS : RD->bases()) {
922  CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
923  bool NewSubobject;
924  // Virtual bases constitute the same subobject. Non-virtual bases are
925  // always distinct subobjects.
926  if (BS.isVirtual())
927  NewSubobject = VBases.insert(BaseDecl).second;
928  else
929  NewSubobject = true;
930 
931  if (NewSubobject)
932  ++SubobjectsSeen[BaseDecl];
933 
934  // Only add subobjects which have public access throughout the entire chain.
935  bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public;
936  if (PublicPath)
937  PublicSubobjectsSeen.insert(BaseDecl);
938 
939  // Recurse on to each base subobject.
940  collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen,
941  PublicPath);
942  }
943 }
944 
947  llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen;
948  llvm::SmallSet<CXXRecordDecl *, 2> VBases;
949  llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen;
950  SubobjectsSeen[RD] = 1;
951  PublicSubobjectsSeen.insert(RD);
952  collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen,
953  /*ParentIsPublic=*/true);
954 
955  for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) {
956  // Skip ambiguous objects.
957  if (SubobjectsSeen[PublicSubobject] > 1)
958  continue;
959 
960  Objects.push_back(PublicSubobject);
961  }
962 }
963 
964 /// CheckCXXThrowOperand - Validate the operand of a throw.
966  QualType ExceptionObjectTy, Expr *E) {
967  // If the type of the exception would be an incomplete type or a pointer
968  // to an incomplete type other than (cv) void the program is ill-formed.
969  QualType Ty = ExceptionObjectTy;
970  bool isPointer = false;
971  if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
972  Ty = Ptr->getPointeeType();
973  isPointer = true;
974  }
975  if (!isPointer || !Ty->isVoidType()) {
976  if (RequireCompleteType(ThrowLoc, Ty,
977  isPointer ? diag::err_throw_incomplete_ptr
978  : diag::err_throw_incomplete,
979  E->getSourceRange()))
980  return true;
981 
982  if (!isPointer && Ty->isSizelessType()) {
983  Diag(ThrowLoc, diag::err_throw_sizeless) << Ty << E->getSourceRange();
984  return true;
985  }
986 
987  if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy,
988  diag::err_throw_abstract_type, E))
989  return true;
990  }
991 
992  // If the exception has class type, we need additional handling.
993  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
994  if (!RD)
995  return false;
996 
997  // If we are throwing a polymorphic class type or pointer thereof,
998  // exception handling will make use of the vtable.
999  MarkVTableUsed(ThrowLoc, RD);
1000 
1001  // If a pointer is thrown, the referenced object will not be destroyed.
1002  if (isPointer)
1003  return false;
1004 
1005  // If the class has a destructor, we must be able to call it.
1006  if (!RD->hasIrrelevantDestructor()) {
1007  if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
1008  MarkFunctionReferenced(E->getExprLoc(), Destructor);
1009  CheckDestructorAccess(E->getExprLoc(), Destructor,
1010  PDiag(diag::err_access_dtor_exception) << Ty);
1011  if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
1012  return true;
1013  }
1014  }
1015 
1016  // The MSVC ABI creates a list of all types which can catch the exception
1017  // object. This list also references the appropriate copy constructor to call
1018  // if the object is caught by value and has a non-trivial copy constructor.
1019  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1020  // We are only interested in the public, unambiguous bases contained within
1021  // the exception object. Bases which are ambiguous or otherwise
1022  // inaccessible are not catchable types.
1023  llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects;
1024  getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects);
1025 
1026  for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) {
1027  // Attempt to lookup the copy constructor. Various pieces of machinery
1028  // will spring into action, like template instantiation, which means this
1029  // cannot be a simple walk of the class's decls. Instead, we must perform
1030  // lookup and overload resolution.
1031  CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
1032  if (!CD || CD->isDeleted())
1033  continue;
1034 
1035  // Mark the constructor referenced as it is used by this throw expression.
1036  MarkFunctionReferenced(E->getExprLoc(), CD);
1037 
1038  // Skip this copy constructor if it is trivial, we don't need to record it
1039  // in the catchable type data.
1040  if (CD->isTrivial())
1041  continue;
1042 
1043  // The copy constructor is non-trivial, create a mapping from this class
1044  // type to this constructor.
1045  // N.B. The selection of copy constructor is not sensitive to this
1046  // particular throw-site. Lookup will be performed at the catch-site to
1047  // ensure that the copy constructor is, in fact, accessible (via
1048  // friendship or any other means).
1049  Context.addCopyConstructorForExceptionObject(Subobject, CD);
1050 
1051  // We don't keep the instantiated default argument expressions around so
1052  // we must rebuild them here.
1053  for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) {
1054  if (CheckCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)))
1055  return true;
1056  }
1057  }
1058  }
1059 
1060  // Under the Itanium C++ ABI, memory for the exception object is allocated by
1061  // the runtime with no ability for the compiler to request additional
1062  // alignment. Warn if the exception type requires alignment beyond the minimum
1063  // guaranteed by the target C++ runtime.
1064  if (Context.getTargetInfo().getCXXABI().isItaniumFamily()) {
1065  CharUnits TypeAlign = Context.getTypeAlignInChars(Ty);
1066  CharUnits ExnObjAlign = Context.getExnObjectAlignment();
1067  if (ExnObjAlign < TypeAlign) {
1068  Diag(ThrowLoc, diag::warn_throw_underaligned_obj);
1069  Diag(ThrowLoc, diag::note_throw_underaligned_obj)
1070  << Ty << (unsigned)TypeAlign.getQuantity()
1071  << (unsigned)ExnObjAlign.getQuantity();
1072  }
1073  }
1074 
1075  return false;
1076 }
1077 
1079  ArrayRef<FunctionScopeInfo *> FunctionScopes, QualType ThisTy,
1080  DeclContext *CurSemaContext, ASTContext &ASTCtx) {
1081 
1082  QualType ClassType = ThisTy->getPointeeType();
1083  LambdaScopeInfo *CurLSI = nullptr;
1084  DeclContext *CurDC = CurSemaContext;
1085 
1086  // Iterate through the stack of lambdas starting from the innermost lambda to
1087  // the outermost lambda, checking if '*this' is ever captured by copy - since
1088  // that could change the cv-qualifiers of the '*this' object.
1089  // The object referred to by '*this' starts out with the cv-qualifiers of its
1090  // member function. We then start with the innermost lambda and iterate
1091  // outward checking to see if any lambda performs a by-copy capture of '*this'
1092  // - and if so, any nested lambda must respect the 'constness' of that
1093  // capturing lamdbda's call operator.
1094  //
1095 
1096  // Since the FunctionScopeInfo stack is representative of the lexical
1097  // nesting of the lambda expressions during initial parsing (and is the best
1098  // place for querying information about captures about lambdas that are
1099  // partially processed) and perhaps during instantiation of function templates
1100  // that contain lambda expressions that need to be transformed BUT not
1101  // necessarily during instantiation of a nested generic lambda's function call
1102  // operator (which might even be instantiated at the end of the TU) - at which
1103  // time the DeclContext tree is mature enough to query capture information
1104  // reliably - we use a two pronged approach to walk through all the lexically
1105  // enclosing lambda expressions:
1106  //
1107  // 1) Climb down the FunctionScopeInfo stack as long as each item represents
1108  // a Lambda (i.e. LambdaScopeInfo) AND each LSI's 'closure-type' is lexically
1109  // enclosed by the call-operator of the LSI below it on the stack (while
1110  // tracking the enclosing DC for step 2 if needed). Note the topmost LSI on
1111  // the stack represents the innermost lambda.
1112  //
1113  // 2) If we run out of enclosing LSI's, check if the enclosing DeclContext
1114  // represents a lambda's call operator. If it does, we must be instantiating
1115  // a generic lambda's call operator (represented by the Current LSI, and
1116  // should be the only scenario where an inconsistency between the LSI and the
1117  // DeclContext should occur), so climb out the DeclContexts if they
1118  // represent lambdas, while querying the corresponding closure types
1119  // regarding capture information.
1120 
1121  // 1) Climb down the function scope info stack.
1122  for (int I = FunctionScopes.size();
1123  I-- && isa<LambdaScopeInfo>(FunctionScopes[I]) &&
1124  (!CurLSI || !CurLSI->Lambda || CurLSI->Lambda->getDeclContext() ==
1125  cast<LambdaScopeInfo>(FunctionScopes[I])->CallOperator);
1126  CurDC = getLambdaAwareParentOfDeclContext(CurDC)) {
1127  CurLSI = cast<LambdaScopeInfo>(FunctionScopes[I]);
1128 
1129  if (!CurLSI->isCXXThisCaptured())
1130  continue;
1131 
1132  auto C = CurLSI->getCXXThisCapture();
1133 
1134  if (C.isCopyCapture()) {
1136  if (CurLSI->CallOperator->isConst())
1137  ClassType.addConst();
1138  return ASTCtx.getPointerType(ClassType);
1139  }
1140  }
1141 
1142  // 2) We've run out of ScopeInfos but check 1. if CurDC is a lambda (which
1143  // can happen during instantiation of its nested generic lambda call
1144  // operator); 2. if we're in a lambda scope (lambda body).
1145  if (CurLSI && isLambdaCallOperator(CurDC)) {
1147  "While computing 'this' capture-type for a generic lambda, when we "
1148  "run out of enclosing LSI's, yet the enclosing DC is a "
1149  "lambda-call-operator we must be (i.e. Current LSI) in a generic "
1150  "lambda call oeprator");
1151  assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator));
1152 
1153  auto IsThisCaptured =
1154  [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) {
1155  IsConst = false;
1156  IsByCopy = false;
1157  for (auto &&C : Closure->captures()) {
1158  if (C.capturesThis()) {
1159  if (C.getCaptureKind() == LCK_StarThis)
1160  IsByCopy = true;
1161  if (Closure->getLambdaCallOperator()->isConst())
1162  IsConst = true;
1163  return true;
1164  }
1165  }
1166  return false;
1167  };
1168 
1169  bool IsByCopyCapture = false;
1170  bool IsConstCapture = false;
1171  CXXRecordDecl *Closure = cast<CXXRecordDecl>(CurDC->getParent());
1172  while (Closure &&
1173  IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) {
1174  if (IsByCopyCapture) {
1176  if (IsConstCapture)
1177  ClassType.addConst();
1178  return ASTCtx.getPointerType(ClassType);
1179  }
1180  Closure = isLambdaCallOperator(Closure->getParent())
1181  ? cast<CXXRecordDecl>(Closure->getParent()->getParent())
1182  : nullptr;
1183  }
1184  }
1185  return ASTCtx.getPointerType(ClassType);
1186 }
1187 
1189  DeclContext *DC = getFunctionLevelDeclContext();
1190  QualType ThisTy = CXXThisTypeOverride;
1191 
1192  if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
1193  if (method && method->isInstance())
1194  ThisTy = method->getThisType();
1195  }
1196 
1197  if (ThisTy.isNull() && isLambdaCallOperator(CurContext) &&
1198  inTemplateInstantiation() && isa<CXXRecordDecl>(DC)) {
1199 
1200  // This is a lambda call operator that is being instantiated as a default
1201  // initializer. DC must point to the enclosing class type, so we can recover
1202  // the 'this' type from it.
1203  QualType ClassTy = Context.getTypeDeclType(cast<CXXRecordDecl>(DC));
1204  // There are no cv-qualifiers for 'this' within default initializers,
1205  // per [expr.prim.general]p4.
1206  ThisTy = Context.getPointerType(ClassTy);
1207  }
1208 
1209  // If we are within a lambda's call operator, the cv-qualifiers of 'this'
1210  // might need to be adjusted if the lambda or any of its enclosing lambda's
1211  // captures '*this' by copy.
1212  if (!ThisTy.isNull() && isLambdaCallOperator(CurContext))
1213  return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy,
1214  CurContext, Context);
1215  return ThisTy;
1216 }
1217 
1219  Decl *ContextDecl,
1220  Qualifiers CXXThisTypeQuals,
1221  bool Enabled)
1222  : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
1223 {
1224  if (!Enabled || !ContextDecl)
1225  return;
1226 
1227  CXXRecordDecl *Record = nullptr;
1228  if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
1229  Record = Template->getTemplatedDecl();
1230  else
1231  Record = cast<CXXRecordDecl>(ContextDecl);
1232 
1233  QualType T = S.Context.getRecordType(Record);
1234  T = S.getASTContext().getQualifiedType(T, CXXThisTypeQuals);
1235 
1237 
1238  this->Enabled = true;
1239 }
1240 
1241 
1243  if (Enabled) {
1244  S.CXXThisTypeOverride = OldCXXThisTypeOverride;
1245  }
1246 }
1247 
1249  SourceLocation DiagLoc = LSI->IntroducerRange.getEnd();
1250  assert(!LSI->isCXXThisCaptured());
1251  // [=, this] {}; // until C++20: Error: this when = is the default
1253  !Sema.getLangOpts().CPlusPlus20)
1254  return;
1255  Sema.Diag(DiagLoc, diag::note_lambda_this_capture_fixit)
1257  DiagLoc, LSI->NumExplicitCaptures > 0 ? ", this" : "this");
1258 }
1259 
1260 bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
1261  bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
1262  const bool ByCopy) {
1263  // We don't need to capture this in an unevaluated context.
1264  if (isUnevaluatedContext() && !Explicit)
1265  return true;
1266 
1267  assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value");
1268 
1269  const int MaxFunctionScopesIndex = FunctionScopeIndexToStopAt
1270  ? *FunctionScopeIndexToStopAt
1271  : FunctionScopes.size() - 1;
1272 
1273  // Check that we can capture the *enclosing object* (referred to by '*this')
1274  // by the capturing-entity/closure (lambda/block/etc) at
1275  // MaxFunctionScopesIndex-deep on the FunctionScopes stack.
1276 
1277  // Note: The *enclosing object* can only be captured by-value by a
1278  // closure that is a lambda, using the explicit notation:
1279  // [*this] { ... }.
1280  // Every other capture of the *enclosing object* results in its by-reference
1281  // capture.
1282 
1283  // For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes
1284  // stack), we can capture the *enclosing object* only if:
1285  // - 'L' has an explicit byref or byval capture of the *enclosing object*
1286  // - or, 'L' has an implicit capture.
1287  // AND
1288  // -- there is no enclosing closure
1289  // -- or, there is some enclosing closure 'E' that has already captured the
1290  // *enclosing object*, and every intervening closure (if any) between 'E'
1291  // and 'L' can implicitly capture the *enclosing object*.
1292  // -- or, every enclosing closure can implicitly capture the
1293  // *enclosing object*
1294 
1295 
1296  unsigned NumCapturingClosures = 0;
1297  for (int idx = MaxFunctionScopesIndex; idx >= 0; idx--) {
1298  if (CapturingScopeInfo *CSI =
1299  dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
1300  if (CSI->CXXThisCaptureIndex != 0) {
1301  // 'this' is already being captured; there isn't anything more to do.
1302  CSI->Captures[CSI->CXXThisCaptureIndex - 1].markUsed(BuildAndDiagnose);
1303  break;
1304  }
1305  LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
1307  // This context can't implicitly capture 'this'; fail out.
1308  if (BuildAndDiagnose) {
1309  Diag(Loc, diag::err_this_capture)
1310  << (Explicit && idx == MaxFunctionScopesIndex);
1311  if (!Explicit)
1312  buildLambdaThisCaptureFixit(*this, LSI);
1313  }
1314  return true;
1315  }
1316  if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
1317  CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||
1318  CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||
1319  CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||
1320  (Explicit && idx == MaxFunctionScopesIndex)) {
1321  // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first
1322  // iteration through can be an explicit capture, all enclosing closures,
1323  // if any, must perform implicit captures.
1324 
1325  // This closure can capture 'this'; continue looking upwards.
1326  NumCapturingClosures++;
1327  continue;
1328  }
1329  // This context can't implicitly capture 'this'; fail out.
1330  if (BuildAndDiagnose)
1331  Diag(Loc, diag::err_this_capture)
1332  << (Explicit && idx == MaxFunctionScopesIndex);
1333 
1334  if (!Explicit)
1335  buildLambdaThisCaptureFixit(*this, LSI);
1336  return true;
1337  }
1338  break;
1339  }
1340  if (!BuildAndDiagnose) return false;
1341 
1342  // If we got here, then the closure at MaxFunctionScopesIndex on the
1343  // FunctionScopes stack, can capture the *enclosing object*, so capture it
1344  // (including implicit by-reference captures in any enclosing closures).
1345 
1346  // In the loop below, respect the ByCopy flag only for the closure requesting
1347  // the capture (i.e. first iteration through the loop below). Ignore it for
1348  // all enclosing closure's up to NumCapturingClosures (since they must be
1349  // implicitly capturing the *enclosing object* by reference (see loop
1350  // above)).
1351  assert((!ByCopy ||
1352  isa<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) &&
1353  "Only a lambda can capture the enclosing object (referred to by "
1354  "*this) by copy");
1355  QualType ThisTy = getCurrentThisType();
1356  for (int idx = MaxFunctionScopesIndex; NumCapturingClosures;
1357  --idx, --NumCapturingClosures) {
1358  CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
1359 
1360  // The type of the corresponding data member (not a 'this' pointer if 'by
1361  // copy').
1362  QualType CaptureType = ThisTy;
1363  if (ByCopy) {
1364  // If we are capturing the object referred to by '*this' by copy, ignore
1365  // any cv qualifiers inherited from the type of the member function for
1366  // the type of the closure-type's corresponding data member and any use
1367  // of 'this'.
1368  CaptureType = ThisTy->getPointeeType();
1370  }
1371 
1372  bool isNested = NumCapturingClosures > 1;
1373  CSI->addThisCapture(isNested, Loc, CaptureType, ByCopy);
1374  }
1375  return false;
1376 }
1377 
1379  /// C++ 9.3.2: In the body of a non-static member function, the keyword this
1380  /// is a non-lvalue expression whose value is the address of the object for
1381  /// which the function is called.
1382 
1383  QualType ThisTy = getCurrentThisType();
1384  if (ThisTy.isNull())
1385  return Diag(Loc, diag::err_invalid_this_use);
1386  return BuildCXXThisExpr(Loc, ThisTy, /*IsImplicit=*/false);
1387 }
1388 
1390  bool IsImplicit) {
1391  auto *This = new (Context) CXXThisExpr(Loc, Type, IsImplicit);
1393  return This;
1394 }
1395 
1397  CheckCXXThisCapture(This->getExprLoc());
1398 }
1399 
1401  // If we're outside the body of a member function, then we'll have a specified
1402  // type for 'this'.
1404  return false;
1405 
1406  // Determine whether we're looking into a class that's currently being
1407  // defined.
1408  CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl();
1409  return Class && Class->isBeingDefined();
1410 }
1411 
1412 /// Parse construction of a specified type.
1413 /// Can be interpreted either as function-style casting ("int(x)")
1414 /// or class type construction ("ClassType(x,y,z)")
1415 /// or creation of a value-initialized type ("int()").
1416 ExprResult
1418  SourceLocation LParenOrBraceLoc,
1419  MultiExprArg exprs,
1420  SourceLocation RParenOrBraceLoc,
1421  bool ListInitialization) {
1422  if (!TypeRep)
1423  return ExprError();
1424 
1425  TypeSourceInfo *TInfo;
1426  QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
1427  if (!TInfo)
1429 
1430  auto Result = BuildCXXTypeConstructExpr(TInfo, LParenOrBraceLoc, exprs,
1431  RParenOrBraceLoc, ListInitialization);
1432  // Avoid creating a non-type-dependent expression that contains typos.
1433  // Non-type-dependent expressions are liable to be discarded without
1434  // checking for embedded typos.
1435  if (!Result.isInvalid() && Result.get()->isInstantiationDependent() &&
1436  !Result.get()->isTypeDependent())
1437  Result = CorrectDelayedTyposInExpr(Result.get());
1438  else if (Result.isInvalid())
1439  Result = CreateRecoveryExpr(TInfo->getTypeLoc().getBeginLoc(),
1440  RParenOrBraceLoc, exprs, Ty);
1441  return Result;
1442 }
1443 
1444 ExprResult
1446  SourceLocation LParenOrBraceLoc,
1447  MultiExprArg Exprs,
1448  SourceLocation RParenOrBraceLoc,
1449  bool ListInitialization) {
1450  QualType Ty = TInfo->getType();
1451  SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();
1452 
1453  assert((!ListInitialization ||
1454  (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) &&
1455  "List initialization must have initializer list as expression.");
1456  SourceRange FullRange = SourceRange(TyBeginLoc, RParenOrBraceLoc);
1457 
1458  InitializedEntity Entity =
1461  Exprs.size()
1462  ? ListInitialization
1464  TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc)
1465  : InitializationKind::CreateDirect(TyBeginLoc, LParenOrBraceLoc,
1466  RParenOrBraceLoc)
1467  : InitializationKind::CreateValue(TyBeginLoc, LParenOrBraceLoc,
1468  RParenOrBraceLoc);
1469 
1470  // C++1z [expr.type.conv]p1:
1471  // If the type is a placeholder for a deduced class type, [...perform class
1472  // template argument deduction...]
1473  // C++2b:
1474  // Otherwise, if the type contains a placeholder type, it is replaced by the
1475  // type determined by placeholder type deduction.
1476  DeducedType *Deduced = Ty->getContainedDeducedType();
1477  if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
1479  Kind, Exprs);
1480  if (Ty.isNull())
1481  return ExprError();
1482  Entity = InitializedEntity::InitializeTemporary(TInfo, Ty);
1483  } else if (Deduced) {
1484  MultiExprArg Inits = Exprs;
1485  if (ListInitialization) {
1486  auto *ILE = cast<InitListExpr>(Exprs[0]);
1487  Inits = MultiExprArg(ILE->getInits(), ILE->getNumInits());
1488  }
1489 
1490  if (Inits.empty())
1491  return ExprError(Diag(TyBeginLoc, diag::err_auto_expr_init_no_expression)
1492  << Ty << FullRange);
1493  if (Inits.size() > 1) {
1494  Expr *FirstBad = Inits[1];
1495  return ExprError(Diag(FirstBad->getBeginLoc(),
1496  diag::err_auto_expr_init_multiple_expressions)
1497  << Ty << FullRange);
1498  }
1499  if (getLangOpts().CPlusPlus2b) {
1500  if (Ty->getAs<AutoType>())
1501  Diag(TyBeginLoc, diag::warn_cxx20_compat_auto_expr) << FullRange;
1502  }
1503  Expr *Deduce = Inits[0];
1504  if (isa<InitListExpr>(Deduce))
1505  return ExprError(
1506  Diag(Deduce->getBeginLoc(), diag::err_auto_expr_init_paren_braces)
1507  << ListInitialization << Ty << FullRange);
1509  if (DeduceAutoType(TInfo, Deduce, DeducedType) == DAR_Failed)
1510  return ExprError(Diag(TyBeginLoc, diag::err_auto_expr_deduction_failure)
1511  << Ty << Deduce->getType() << FullRange
1512  << Deduce->getSourceRange());
1513  if (DeducedType.isNull())
1514  return ExprError();
1515 
1516  Ty = DeducedType;
1517  Entity = InitializedEntity::InitializeTemporary(TInfo, Ty);
1518  }
1519 
1521  // FIXME: CXXUnresolvedConstructExpr does not model list-initialization
1522  // directly. We work around this by dropping the locations of the braces.
1523  SourceRange Locs = ListInitialization
1524  ? SourceRange()
1525  : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
1527  TInfo, Locs.getBegin(), Exprs,
1528  Locs.getEnd());
1529  }
1530 
1531  // C++ [expr.type.conv]p1:
1532  // If the expression list is a parenthesized single expression, the type
1533  // conversion expression is equivalent (in definedness, and if defined in
1534  // meaning) to the corresponding cast expression.
1535  if (Exprs.size() == 1 && !ListInitialization &&
1536  !isa<InitListExpr>(Exprs[0])) {
1537  Expr *Arg = Exprs[0];
1538  return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenOrBraceLoc, Arg,
1539  RParenOrBraceLoc);
1540  }
1541 
1542  // For an expression of the form T(), T shall not be an array type.
1543  QualType ElemTy = Ty;
1544  if (Ty->isArrayType()) {
1545  if (!ListInitialization)
1546  return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type)
1547  << FullRange);
1548  ElemTy = Context.getBaseElementType(Ty);
1549  }
1550 
1551  // Only construct objects with object types.
1552  // The standard doesn't explicitly forbid function types here, but that's an
1553  // obvious oversight, as there's no way to dynamically construct a function
1554  // in general.
1555  if (Ty->isFunctionType())
1556  return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type)
1557  << Ty << FullRange);
1558 
1559  // C++17 [expr.type.conv]p2:
1560  // If the type is cv void and the initializer is (), the expression is a
1561  // prvalue of the specified type that performs no initialization.
1562  if (!Ty->isVoidType() &&
1563  RequireCompleteType(TyBeginLoc, ElemTy,
1564  diag::err_invalid_incomplete_type_use, FullRange))
1565  return ExprError();
1566 
1567  // Otherwise, the expression is a prvalue of the specified type whose
1568  // result object is direct-initialized (11.6) with the initializer.
1569  InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
1570  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);
1571 
1572  if (Result.isInvalid())
1573  return Result;
1574 
1575  Expr *Inner = Result.get();
1576  if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
1577  Inner = BTE->getSubExpr();
1578  if (!isa<CXXTemporaryObjectExpr>(Inner) &&
1579  !isa<CXXScalarValueInitExpr>(Inner)) {
1580  // If we created a CXXTemporaryObjectExpr, that node also represents the
1581  // functional cast. Otherwise, create an explicit cast to represent
1582  // the syntactic form of a functional-style cast that was used here.
1583  //
1584  // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr
1585  // would give a more consistent AST representation than using a
1586  // CXXTemporaryObjectExpr. It's also weird that the functional cast
1587  // is sometimes handled by initialization and sometimes not.
1588  QualType ResultType = Result.get()->getType();
1589  SourceRange Locs = ListInitialization
1590  ? SourceRange()
1591  : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
1593  Context, ResultType, Expr::getValueKindForType(Ty), TInfo, CK_NoOp,
1594  Result.get(), /*Path=*/nullptr, CurFPFeatureOverrides(),
1595  Locs.getBegin(), Locs.getEnd());
1596  }
1597 
1598  return Result;
1599 }
1600 
1602  // [CUDA] Ignore this function, if we can't call it.
1603  const FunctionDecl *Caller = getCurFunctionDecl(/*AllowLambda=*/true);
1604  if (getLangOpts().CUDA) {
1605  auto CallPreference = IdentifyCUDAPreference(Caller, Method);
1606  // If it's not callable at all, it's not the right function.
1607  if (CallPreference < CFP_WrongSide)
1608  return false;
1609  if (CallPreference == CFP_WrongSide) {
1610  // Maybe. We have to check if there are better alternatives.
1612  Method->getDeclContext()->lookup(Method->getDeclName());
1613  for (const auto *D : R) {
1614  if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
1615  if (IdentifyCUDAPreference(Caller, FD) > CFP_WrongSide)
1616  return false;
1617  }
1618  }
1619  // We've found no better variants.
1620  }
1621  }
1622 
1624  bool Result = Method->isUsualDeallocationFunction(PreventedBy);
1625 
1626  if (Result || !getLangOpts().CUDA || PreventedBy.empty())
1627  return Result;
1628 
1629  // In case of CUDA, return true if none of the 1-argument deallocator
1630  // functions are actually callable.
1631  return llvm::none_of(PreventedBy, [&](const FunctionDecl *FD) {
1632  assert(FD->getNumParams() == 1 &&
1633  "Only single-operand functions should be in PreventedBy");
1634  return IdentifyCUDAPreference(Caller, FD) >= CFP_HostDevice;
1635  });
1636 }
1637 
1638 /// Determine whether the given function is a non-placement
1639 /// deallocation function.
1641  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
1642  return S.isUsualDeallocationFunction(Method);
1643 
1644  if (FD->getOverloadedOperator() != OO_Delete &&
1645  FD->getOverloadedOperator() != OO_Array_Delete)
1646  return false;
1647 
1648  unsigned UsualParams = 1;
1649 
1650  if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() &&
1652  FD->getParamDecl(UsualParams)->getType(),
1653  S.Context.getSizeType()))
1654  ++UsualParams;
1655 
1656  if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() &&
1658  FD->getParamDecl(UsualParams)->getType(),
1660  ++UsualParams;
1661 
1662  return UsualParams == FD->getNumParams();
1663 }
1664 
1665 namespace {
1666  struct UsualDeallocFnInfo {
1667  UsualDeallocFnInfo() : Found(), FD(nullptr) {}
1668  UsualDeallocFnInfo(Sema &S, DeclAccessPair Found)
1669  : Found(Found), FD(dyn_cast<FunctionDecl>(Found->getUnderlyingDecl())),
1670  Destroying(false), HasSizeT(false), HasAlignValT(false),
1671  CUDAPref(Sema::CFP_Native) {
1672  // A function template declaration is never a usual deallocation function.
1673  if (!FD)
1674  return;
1675  unsigned NumBaseParams = 1;
1676  if (FD->isDestroyingOperatorDelete()) {
1677  Destroying = true;
1678  ++NumBaseParams;
1679  }
1680 
1681  if (NumBaseParams < FD->getNumParams() &&
1683  FD->getParamDecl(NumBaseParams)->getType(),
1684  S.Context.getSizeType())) {
1685  ++NumBaseParams;
1686  HasSizeT = true;
1687  }
1688 
1689  if (NumBaseParams < FD->getNumParams() &&
1690  FD->getParamDecl(NumBaseParams)->getType()->isAlignValT()) {
1691  ++NumBaseParams;
1692  HasAlignValT = true;
1693  }
1694 
1695  // In CUDA, determine how much we'd like / dislike to call this.
1696  if (S.getLangOpts().CUDA)
1697  if (auto *Caller = S.getCurFunctionDecl(/*AllowLambda=*/true))
1698  CUDAPref = S.IdentifyCUDAPreference(Caller, FD);
1699  }
1700 
1701  explicit operator bool() const { return FD; }
1702 
1703  bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize,
1704  bool WantAlign) const {
1705  // C++ P0722:
1706  // A destroying operator delete is preferred over a non-destroying
1707  // operator delete.
1708  if (Destroying != Other.Destroying)
1709  return Destroying;
1710 
1711  // C++17 [expr.delete]p10:
1712  // If the type has new-extended alignment, a function with a parameter
1713  // of type std::align_val_t is preferred; otherwise a function without
1714  // such a parameter is preferred
1715  if (HasAlignValT != Other.HasAlignValT)
1716  return HasAlignValT == WantAlign;
1717 
1718  if (HasSizeT != Other.HasSizeT)
1719  return HasSizeT == WantSize;
1720 
1721  // Use CUDA call preference as a tiebreaker.
1722  return CUDAPref > Other.CUDAPref;
1723  }
1724 
1725  DeclAccessPair Found;
1726  FunctionDecl *FD;
1727  bool Destroying, HasSizeT, HasAlignValT;
1729  };
1730 }
1731 
1732 /// Determine whether a type has new-extended alignment. This may be called when
1733 /// the type is incomplete (for a delete-expression with an incomplete pointee
1734 /// type), in which case it will conservatively return false if the alignment is
1735 /// not known.
1736 static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) {
1737  return S.getLangOpts().AlignedAllocation &&
1738  S.getASTContext().getTypeAlignIfKnown(AllocType) >
1740 }
1741 
1742 /// Select the correct "usual" deallocation function to use from a selection of
1743 /// deallocation functions (either global or class-scope).
1744 static UsualDeallocFnInfo resolveDeallocationOverload(
1745  Sema &S, LookupResult &R, bool WantSize, bool WantAlign,
1746  llvm::SmallVectorImpl<UsualDeallocFnInfo> *BestFns = nullptr) {
1747  UsualDeallocFnInfo Best;
1748 
1749  for (auto I = R.begin(), E = R.end(); I != E; ++I) {
1750  UsualDeallocFnInfo Info(S, I.getPair());
1751  if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) ||
1752  Info.CUDAPref == Sema::CFP_Never)
1753  continue;
1754 
1755  if (!Best) {
1756  Best = Info;
1757  if (BestFns)
1758  BestFns->push_back(Info);
1759  continue;
1760  }
1761 
1762  if (Best.isBetterThan(Info, WantSize, WantAlign))
1763  continue;
1764 
1765  // If more than one preferred function is found, all non-preferred
1766  // functions are eliminated from further consideration.
1767  if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign))
1768  BestFns->clear();
1769 
1770  Best = Info;
1771  if (BestFns)
1772  BestFns->push_back(Info);
1773  }
1774 
1775  return Best;
1776 }
1777 
1778 /// Determine whether a given type is a class for which 'delete[]' would call
1779 /// a member 'operator delete[]' with a 'size_t' parameter. This implies that
1780 /// we need to store the array size (even if the type is
1781 /// trivially-destructible).
1783  QualType allocType) {
1784  const RecordType *record =
1785  allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
1786  if (!record) return false;
1787 
1788  // Try to find an operator delete[] in class scope.
1789 
1790  DeclarationName deleteName =
1791  S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
1792  LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
1793  S.LookupQualifiedName(ops, record->getDecl());
1794 
1795  // We're just doing this for information.
1796  ops.suppressDiagnostics();
1797 
1798  // Very likely: there's no operator delete[].
1799  if (ops.empty()) return false;
1800 
1801  // If it's ambiguous, it should be illegal to call operator delete[]
1802  // on this thing, so it doesn't matter if we allocate extra space or not.
1803  if (ops.isAmbiguous()) return false;
1804 
1805  // C++17 [expr.delete]p10:
1806  // If the deallocation functions have class scope, the one without a
1807  // parameter of type std::size_t is selected.
1808  auto Best = resolveDeallocationOverload(
1809  S, ops, /*WantSize*/false,
1810  /*WantAlign*/hasNewExtendedAlignment(S, allocType));
1811  return Best && Best.HasSizeT;
1812 }
1813 
1814 /// Parsed a C++ 'new' expression (C++ 5.3.4).
1815 ///
1816 /// E.g.:
1817 /// @code new (memory) int[size][4] @endcode
1818 /// or
1819 /// @code ::new Foo(23, "hello") @endcode
1820 ///
1821 /// \param StartLoc The first location of the expression.
1822 /// \param UseGlobal True if 'new' was prefixed with '::'.
1823 /// \param PlacementLParen Opening paren of the placement arguments.
1824 /// \param PlacementArgs Placement new arguments.
1825 /// \param PlacementRParen Closing paren of the placement arguments.
1826 /// \param TypeIdParens If the type is in parens, the source range.
1827 /// \param D The type to be allocated, as well as array dimensions.
1828 /// \param Initializer The initializing expression or initializer-list, or null
1829 /// if there is none.
1830 ExprResult
1831 Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
1832  SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
1833  SourceLocation PlacementRParen, SourceRange TypeIdParens,
1834  Declarator &D, Expr *Initializer) {
1835  Optional<Expr *> ArraySize;
1836  // If the specified type is an array, unwrap it and save the expression.
1837  if (D.getNumTypeObjects() > 0 &&
1839  DeclaratorChunk &Chunk = D.getTypeObject(0);
1840  if (D.getDeclSpec().hasAutoTypeSpec())
1841  return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
1842  << D.getSourceRange());
1843  if (Chunk.Arr.hasStatic)
1844  return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
1845  << D.getSourceRange());
1846  if (!Chunk.Arr.NumElts && !Initializer)
1847  return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
1848  << D.getSourceRange());
1849 
1850  ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
1851  D.DropFirstTypeObject();
1852  }
1853 
1854  // Every dimension shall be of constant size.
1855  if (ArraySize) {
1856  for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
1858  break;
1859 
1861  if (Expr *NumElts = (Expr *)Array.NumElts) {
1862  if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
1863  // FIXME: GCC permits constant folding here. We should either do so consistently
1864  // or not do so at all, rather than changing behavior in C++14 onwards.
1865  if (getLangOpts().CPlusPlus14) {
1866  // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
1867  // shall be a converted constant expression (5.19) of type std::size_t
1868  // and shall evaluate to a strictly positive value.
1870  Array.NumElts
1873  .get();
1874  } else {
1875  Array.NumElts =
1877  NumElts, nullptr, diag::err_new_array_nonconst, AllowFold)
1878  .get();
1879  }
1880  if (!Array.NumElts)
1881  return ExprError();
1882  }
1883  }
1884  }
1885  }
1886 
1887  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
1888  QualType AllocType = TInfo->getType();
1889  if (D.isInvalidType())
1890  return ExprError();
1891 
1892  SourceRange DirectInitRange;
1893  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
1894  DirectInitRange = List->getSourceRange();
1895 
1896  return BuildCXXNew(SourceRange(StartLoc, D.getEndLoc()), UseGlobal,
1897  PlacementLParen, PlacementArgs, PlacementRParen,
1898  TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange,
1899  Initializer);
1900 }
1901 
1903  Expr *Init) {
1904  if (!Init)
1905  return true;
1906  if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
1907  return PLE->getNumExprs() == 0;
1908  if (isa<ImplicitValueInitExpr>(Init))
1909  return true;
1910  else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
1911  return !CCE->isListInitialization() &&
1912  CCE->getConstructor()->isDefaultConstructor();
1913  else if (Style == CXXNewExpr::ListInit) {
1914  assert(isa<InitListExpr>(Init) &&
1915  "Shouldn't create list CXXConstructExprs for arrays.");
1916  return true;
1917  }
1918  return false;
1919 }
1920 
1921 bool
1923  if (!getLangOpts().AlignedAllocationUnavailable)
1924  return false;
1925  if (FD.isDefined())
1926  return false;
1927  Optional<unsigned> AlignmentParam;
1928  if (FD.isReplaceableGlobalAllocationFunction(&AlignmentParam) &&
1929  AlignmentParam.hasValue())
1930  return true;
1931  return false;
1932 }
1933 
1934 // Emit a diagnostic if an aligned allocation/deallocation function that is not
1935 // implemented in the standard library is selected.
1937  SourceLocation Loc) {
1939  const llvm::Triple &T = getASTContext().getTargetInfo().getTriple();
1940  StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling(
1941  getASTContext().getTargetInfo().getPlatformName());
1942  VersionTuple OSVersion = alignedAllocMinVersion(T.getOS());
1943 
1945  bool IsDelete = Kind == OO_Delete || Kind == OO_Array_Delete;
1946  Diag(Loc, diag::err_aligned_allocation_unavailable)
1947  << IsDelete << FD.getType().getAsString() << OSName
1948  << OSVersion.getAsString() << OSVersion.empty();
1949  Diag(Loc, diag::note_silence_aligned_allocation_unavailable);
1950  }
1951 }
1952 
1953 ExprResult
1954 Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
1955  SourceLocation PlacementLParen,
1956  MultiExprArg PlacementArgs,
1957  SourceLocation PlacementRParen,
1958  SourceRange TypeIdParens,
1959  QualType AllocType,
1960  TypeSourceInfo *AllocTypeInfo,
1961  Optional<Expr *> ArraySize,
1962  SourceRange DirectInitRange,
1963  Expr *Initializer) {
1964  SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
1965  SourceLocation StartLoc = Range.getBegin();
1966 
1968  if (DirectInitRange.isValid()) {
1969  assert(Initializer && "Have parens but no initializer.");
1970  initStyle = CXXNewExpr::CallInit;
1971  } else if (Initializer && isa<InitListExpr>(Initializer))
1972  initStyle = CXXNewExpr::ListInit;
1973  else {
1974  assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||
1975  isa<CXXConstructExpr>(Initializer)) &&
1976  "Initializer expression that cannot have been implicitly created.");
1977  initStyle = CXXNewExpr::NoInit;
1978  }
1979 
1980  MultiExprArg Exprs(&Initializer, Initializer ? 1 : 0);
1981  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
1982  assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init");
1983  Exprs = MultiExprArg(List->getExprs(), List->getNumExprs());
1984  }
1985 
1986  // C++11 [expr.new]p15:
1987  // A new-expression that creates an object of type T initializes that
1988  // object as follows:
1990  // - If the new-initializer is omitted, the object is default-
1991  // initialized (8.5); if no initialization is performed,
1992  // the object has indeterminate value
1993  = initStyle == CXXNewExpr::NoInit
1995  // - Otherwise, the new-initializer is interpreted according to
1996  // the
1997  // initialization rules of 8.5 for direct-initialization.
1998  : initStyle == CXXNewExpr::ListInit
2000  TypeRange.getBegin(), Initializer->getBeginLoc(),
2001  Initializer->getEndLoc())
2003  DirectInitRange.getBegin(),
2004  DirectInitRange.getEnd());
2005 
2006  // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
2007  auto *Deduced = AllocType->getContainedDeducedType();
2008  if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
2009  if (ArraySize)
2010  return ExprError(
2011  Diag(*ArraySize ? (*ArraySize)->getExprLoc() : TypeRange.getBegin(),
2012  diag::err_deduced_class_template_compound_type)
2013  << /*array*/ 2
2014  << (*ArraySize ? (*ArraySize)->getSourceRange() : TypeRange));
2015 
2016  InitializedEntity Entity
2017  = InitializedEntity::InitializeNew(StartLoc, AllocType);
2019  AllocTypeInfo, Entity, Kind, Exprs);
2020  if (AllocType.isNull())
2021  return ExprError();
2022  } else if (Deduced) {
2023  MultiExprArg Inits = Exprs;
2024  bool Braced = (initStyle == CXXNewExpr::ListInit);
2025  if (Braced) {
2026  auto *ILE = cast<InitListExpr>(Exprs[0]);
2027  Inits = MultiExprArg(ILE->getInits(), ILE->getNumInits());
2028  }
2029 
2030  if (initStyle == CXXNewExpr::NoInit || Inits.empty())
2031  return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
2032  << AllocType << TypeRange);
2033  if (Inits.size() > 1) {
2034  Expr *FirstBad = Inits[1];
2035  return ExprError(Diag(FirstBad->getBeginLoc(),
2036  diag::err_auto_new_ctor_multiple_expressions)
2037  << AllocType << TypeRange);
2038  }
2039  if (Braced && !getLangOpts().CPlusPlus17)
2040  Diag(Initializer->getBeginLoc(), diag::ext_auto_new_list_init)
2041  << AllocType << TypeRange;
2042  Expr *Deduce = Inits[0];
2043  if (isa<InitListExpr>(Deduce))
2044  return ExprError(
2045  Diag(Deduce->getBeginLoc(), diag::err_auto_expr_init_paren_braces)
2046  << Braced << AllocType << TypeRange);
2048  if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed)
2049  return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
2050  << AllocType << Deduce->getType()
2051  << TypeRange << Deduce->getSourceRange());
2052  if (DeducedType.isNull())
2053  return ExprError();
2054  AllocType = DeducedType;
2055  }
2056 
2057  // Per C++0x [expr.new]p5, the type being constructed may be a
2058  // typedef of an array type.
2059  if (!ArraySize) {
2060  if (const ConstantArrayType *Array
2061  = Context.getAsConstantArrayType(AllocType)) {
2062  ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
2063  Context.getSizeType(),
2064  TypeRange.getEnd());
2065  AllocType = Array->getElementType();
2066  }
2067  }
2068 
2069  if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
2070  return ExprError();
2071 
2072  // In ARC, infer 'retaining' for the allocated
2073  if (getLangOpts().ObjCAutoRefCount &&
2074  AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
2075  AllocType->isObjCLifetimeType()) {
2076  AllocType = Context.getLifetimeQualifiedType(AllocType,
2077  AllocType->getObjCARCImplicitLifetime());
2078  }
2079 
2080  QualType ResultType = Context.getPointerType(AllocType);
2081 
2082  if (ArraySize && *ArraySize &&
2083  (*ArraySize)->getType()->isNonOverloadPlaceholderType()) {
2084  ExprResult result = CheckPlaceholderExpr(*ArraySize);
2085  if (result.isInvalid()) return ExprError();
2086  ArraySize = result.get();
2087  }
2088  // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
2089  // integral or enumeration type with a non-negative value."
2090  // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
2091  // enumeration type, or a class type for which a single non-explicit
2092  // conversion function to integral or unscoped enumeration type exists.
2093  // C++1y [expr.new]p6: The expression [...] is implicitly converted to
2094  // std::size_t.
2095  llvm::Optional<uint64_t> KnownArraySize;
2096  if (ArraySize && *ArraySize && !(*ArraySize)->isTypeDependent()) {
2097  ExprResult ConvertedSize;
2098  if (getLangOpts().CPlusPlus14) {
2099  assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?");
2100 
2101  ConvertedSize = PerformImplicitConversion(*ArraySize, Context.getSizeType(),
2102  AA_Converting);
2103 
2104  if (!ConvertedSize.isInvalid() &&
2105  (*ArraySize)->getType()->getAs<RecordType>())
2106  // Diagnose the compatibility of this conversion.
2107  Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
2108  << (*ArraySize)->getType() << 0 << "'size_t'";
2109  } else {
2110  class SizeConvertDiagnoser : public ICEConvertDiagnoser {
2111  protected:
2112  Expr *ArraySize;
2113 
2114  public:
2115  SizeConvertDiagnoser(Expr *ArraySize)
2116  : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
2117  ArraySize(ArraySize) {}
2118 
2119  SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
2120  QualType T) override {
2121  return S.Diag(Loc, diag::err_array_size_not_integral)
2122  << S.getLangOpts().CPlusPlus11 << T;
2123  }
2124 
2125  SemaDiagnosticBuilder diagnoseIncomplete(
2126  Sema &S, SourceLocation Loc, QualType T) override {
2127  return S.Diag(Loc, diag::err_array_size_incomplete_type)
2128  << T << ArraySize->getSourceRange();
2129  }
2130 
2131  SemaDiagnosticBuilder diagnoseExplicitConv(
2132  Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
2133  return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
2134  }
2135 
2136  SemaDiagnosticBuilder noteExplicitConv(
2137  Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
2138  return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
2139  << ConvTy->isEnumeralType() << ConvTy;
2140  }
2141 
2142  SemaDiagnosticBuilder diagnoseAmbiguous(
2143  Sema &S, SourceLocation Loc, QualType T) override {
2144  return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
2145  }
2146 
2147  SemaDiagnosticBuilder noteAmbiguous(
2148  Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
2149  return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
2150  << ConvTy->isEnumeralType() << ConvTy;
2151  }
2152 
2153  SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
2154  QualType T,
2155  QualType ConvTy) override {
2156  return S.Diag(Loc,
2157  S.getLangOpts().CPlusPlus11
2158  ? diag::warn_cxx98_compat_array_size_conversion
2159  : diag::ext_array_size_conversion)
2160  << T << ConvTy->isEnumeralType() << ConvTy;
2161  }
2162  } SizeDiagnoser(*ArraySize);
2163 
2164  ConvertedSize = PerformContextualImplicitConversion(StartLoc, *ArraySize,
2165  SizeDiagnoser);
2166  }
2167  if (ConvertedSize.isInvalid())
2168  return ExprError();
2169 
2170  ArraySize = ConvertedSize.get();
2171  QualType SizeType = (*ArraySize)->getType();
2172 
2173  if (!SizeType->isIntegralOrUnscopedEnumerationType())
2174  return ExprError();
2175 
2176  // C++98 [expr.new]p7:
2177  // The expression in a direct-new-declarator shall have integral type
2178  // with a non-negative value.
2179  //
2180  // Let's see if this is a constant < 0. If so, we reject it out of hand,
2181  // per CWG1464. Otherwise, if it's not a constant, we must have an
2182  // unparenthesized array type.
2183 
2184  // We've already performed any required implicit conversion to integer or
2185  // unscoped enumeration type.
2186  // FIXME: Per CWG1464, we are required to check the value prior to
2187  // converting to size_t. This will never find a negative array size in
2188  // C++14 onwards, because Value is always unsigned here!
2190  (*ArraySize)->getIntegerConstantExpr(Context)) {
2191  if (Value->isSigned() && Value->isNegative()) {
2192  return ExprError(Diag((*ArraySize)->getBeginLoc(),
2193  diag::err_typecheck_negative_array_size)
2194  << (*ArraySize)->getSourceRange());
2195  }
2196 
2197  if (!AllocType->isDependentType()) {
2198  unsigned ActiveSizeBits =
2200  if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
2201  return ExprError(
2202  Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large)
2203  << toString(*Value, 10) << (*ArraySize)->getSourceRange());
2204  }
2205 
2206  KnownArraySize = Value->getZExtValue();
2207  } else if (TypeIdParens.isValid()) {
2208  // Can't have dynamic array size when the type-id is in parentheses.
2209  Diag((*ArraySize)->getBeginLoc(), diag::ext_new_paren_array_nonconst)
2210  << (*ArraySize)->getSourceRange()
2211  << FixItHint::CreateRemoval(TypeIdParens.getBegin())
2212  << FixItHint::CreateRemoval(TypeIdParens.getEnd());
2213 
2214  TypeIdParens = SourceRange();
2215  }
2216 
2217  // Note that we do *not* convert the argument in any way. It can
2218  // be signed, larger than size_t, whatever.
2219  }
2220 
2221  FunctionDecl *OperatorNew = nullptr;
2222  FunctionDecl *OperatorDelete = nullptr;
2223  unsigned Alignment =
2224  AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType);
2225  unsigned NewAlignment = Context.getTargetInfo().getNewAlign();
2226  bool PassAlignment = getLangOpts().AlignedAllocation &&
2227  Alignment > NewAlignment;
2228 
2230  if (!AllocType->isDependentType() &&
2231  !Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
2233  StartLoc, SourceRange(PlacementLParen, PlacementRParen), Scope, Scope,
2234  AllocType, ArraySize.hasValue(), PassAlignment, PlacementArgs,
2235  OperatorNew, OperatorDelete))
2236  return ExprError();
2237 
2238  // If this is an array allocation, compute whether the usual array
2239  // deallocation function for the type has a size_t parameter.
2240  bool UsualArrayDeleteWantsSize = false;
2241  if (ArraySize && !AllocType->isDependentType())
2242  UsualArrayDeleteWantsSize =
2243  doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);
2244 
2245  SmallVector<Expr *, 8> AllPlaceArgs;
2246  if (OperatorNew) {
2247  auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();
2248  VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
2250 
2251  // We've already converted the placement args, just fill in any default
2252  // arguments. Skip the first parameter because we don't have a corresponding
2253  // argument. Skip the second parameter too if we're passing in the
2254  // alignment; we've already filled it in.
2255  unsigned NumImplicitArgs = PassAlignment ? 2 : 1;
2256  if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto,
2257  NumImplicitArgs, PlacementArgs, AllPlaceArgs,
2258  CallType))
2259  return ExprError();
2260 
2261  if (!AllPlaceArgs.empty())
2262  PlacementArgs = AllPlaceArgs;
2263 
2264  // We would like to perform some checking on the given `operator new` call,
2265  // but the PlacementArgs does not contain the implicit arguments,
2266  // namely allocation size and maybe allocation alignment,
2267  // so we need to conjure them.
2268 
2269  QualType SizeTy = Context.getSizeType();
2270  unsigned SizeTyWidth = Context.getTypeSize(SizeTy);
2271 
2272  llvm::APInt SingleEltSize(
2273  SizeTyWidth, Context.getTypeSizeInChars(AllocType).getQuantity());
2274 
2275  // How many bytes do we want to allocate here?
2276  llvm::Optional<llvm::APInt> AllocationSize;
2277  if (!ArraySize.hasValue() && !AllocType->isDependentType()) {
2278  // For non-array operator new, we only want to allocate one element.
2279  AllocationSize = SingleEltSize;
2280  } else if (KnownArraySize.hasValue() && !AllocType->isDependentType()) {
2281  // For array operator new, only deal with static array size case.
2282  bool Overflow;
2283  AllocationSize = llvm::APInt(SizeTyWidth, *KnownArraySize)
2284  .umul_ov(SingleEltSize, Overflow);
2285  (void)Overflow;
2286  assert(
2287  !Overflow &&
2288  "Expected that all the overflows would have been handled already.");
2289  }
2290 
2291  IntegerLiteral AllocationSizeLiteral(
2292  Context, AllocationSize.getValueOr(llvm::APInt::getZero(SizeTyWidth)),
2293  SizeTy, SourceLocation());
2294  // Otherwise, if we failed to constant-fold the allocation size, we'll
2295  // just give up and pass-in something opaque, that isn't a null pointer.
2296  OpaqueValueExpr OpaqueAllocationSize(SourceLocation(), SizeTy, VK_PRValue,
2297  OK_Ordinary, /*SourceExpr=*/nullptr);
2298 
2299  // Let's synthesize the alignment argument in case we will need it.
2300  // Since we *really* want to allocate these on stack, this is slightly ugly
2301  // because there might not be a `std::align_val_t` type.
2303  QualType AlignValT =
2305  IntegerLiteral AlignmentLiteral(
2306  Context,
2308  Alignment / Context.getCharWidth()),
2309  SizeTy, SourceLocation());
2310  ImplicitCastExpr DesiredAlignment(ImplicitCastExpr::OnStack, AlignValT,
2311  CK_IntegralCast, &AlignmentLiteral,
2313 
2314  // Adjust placement args by prepending conjured size and alignment exprs.
2316  CallArgs.reserve(NumImplicitArgs + PlacementArgs.size());
2317  CallArgs.emplace_back(AllocationSize.hasValue()
2318  ? static_cast<Expr *>(&AllocationSizeLiteral)
2319  : &OpaqueAllocationSize);
2320  if (PassAlignment)
2321  CallArgs.emplace_back(&DesiredAlignment);
2322  CallArgs.insert(CallArgs.end(), PlacementArgs.begin(), PlacementArgs.end());
2323 
2324  DiagnoseSentinelCalls(OperatorNew, PlacementLParen, CallArgs);
2325 
2326  checkCall(OperatorNew, Proto, /*ThisArg=*/nullptr, CallArgs,
2327  /*IsMemberFunction=*/false, StartLoc, Range, CallType);
2328 
2329  // Warn if the type is over-aligned and is being allocated by (unaligned)
2330  // global operator new.
2331  if (PlacementArgs.empty() && !PassAlignment &&
2332  (OperatorNew->isImplicit() ||
2333  (OperatorNew->getBeginLoc().isValid() &&
2334  getSourceManager().isInSystemHeader(OperatorNew->getBeginLoc())))) {
2335  if (Alignment > NewAlignment)
2336  Diag(StartLoc, diag::warn_overaligned_type)
2337  << AllocType
2338  << unsigned(Alignment / Context.getCharWidth())
2339  << unsigned(NewAlignment / Context.getCharWidth());
2340  }
2341  }
2342 
2343  // Array 'new' can't have any initializers except empty parentheses.
2344  // Initializer lists are also allowed, in C++11. Rely on the parser for the
2345  // dialect distinction.
2346  if (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) {
2347  SourceRange InitRange(Exprs.front()->getBeginLoc(),
2348  Exprs.back()->getEndLoc());
2349  Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
2350  return ExprError();
2351  }
2352 
2353  // If we can perform the initialization, and we've not already done so,
2354  // do it now.
2355  if (!AllocType->isDependentType() &&
2357  // The type we initialize is the complete type, including the array bound.
2358  QualType InitType;
2359  if (KnownArraySize)
2360  InitType = Context.getConstantArrayType(
2361  AllocType,
2363  *KnownArraySize),
2364  *ArraySize, ArrayType::Normal, 0);
2365  else if (ArraySize)
2366  InitType =
2368  else
2369  InitType = AllocType;
2370 
2371  InitializedEntity Entity
2372  = InitializedEntity::InitializeNew(StartLoc, InitType);
2373  InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
2374  ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, Exprs);
2375  if (FullInit.isInvalid())
2376  return ExprError();
2377 
2378  // FullInit is our initializer; strip off CXXBindTemporaryExprs, because
2379  // we don't want the initialized object to be destructed.
2380  // FIXME: We should not create these in the first place.
2381  if (CXXBindTemporaryExpr *Binder =
2382  dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
2383  FullInit = Binder->getSubExpr();
2384 
2385  Initializer = FullInit.get();
2386 
2387  // FIXME: If we have a KnownArraySize, check that the array bound of the
2388  // initializer is no greater than that constant value.
2389 
2390  if (ArraySize && !*ArraySize) {
2391  auto *CAT = Context.getAsConstantArrayType(Initializer->getType());
2392  if (CAT) {
2393  // FIXME: Track that the array size was inferred rather than explicitly
2394  // specified.
2395  ArraySize = IntegerLiteral::Create(
2396  Context, CAT->getSize(), Context.getSizeType(), TypeRange.getEnd());
2397  } else {
2398  Diag(TypeRange.getEnd(), diag::err_new_array_size_unknown_from_init)
2399  << Initializer->getSourceRange();
2400  }
2401  }
2402  }
2403 
2404  // Mark the new and delete operators as referenced.
2405  if (OperatorNew) {
2406  if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
2407  return ExprError();
2408  MarkFunctionReferenced(StartLoc, OperatorNew);
2409  }
2410  if (OperatorDelete) {
2411  if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
2412  return ExprError();
2413  MarkFunctionReferenced(StartLoc, OperatorDelete);
2414  }
2415 
2416  return CXXNewExpr::Create(Context, UseGlobal, OperatorNew, OperatorDelete,
2417  PassAlignment, UsualArrayDeleteWantsSize,
2418  PlacementArgs, TypeIdParens, ArraySize, initStyle,
2419  Initializer, ResultType, AllocTypeInfo, Range,
2420  DirectInitRange);
2421 }
2422 
2423 /// Checks that a type is suitable as the allocated type
2424 /// in a new-expression.
2426  SourceRange R) {
2427  // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
2428  // abstract class type or array thereof.
2429  if (AllocType->isFunctionType())
2430  return Diag(Loc, diag::err_bad_new_type)
2431  << AllocType << 0 << R;
2432  else if (AllocType->isReferenceType())
2433  return Diag(Loc, diag::err_bad_new_type)
2434  << AllocType << 1 << R;
2435  else if (!AllocType->isDependentType() &&
2437  Loc, AllocType, diag::err_new_incomplete_or_sizeless_type, R))
2438  return true;
2439  else if (RequireNonAbstractType(Loc, AllocType,
2440  diag::err_allocation_of_abstract_type))
2441  return true;
2442  else if (AllocType->isVariablyModifiedType())
2443  return Diag(Loc, diag::err_variably_modified_new_type)
2444  << AllocType;
2445  else if (AllocType.getAddressSpace() != LangAS::Default &&
2446  !getLangOpts().OpenCLCPlusPlus)
2447  return Diag(Loc, diag::err_address_space_qualified_new)
2448  << AllocType.getUnqualifiedType()
2450  else if (getLangOpts().ObjCAutoRefCount) {
2451  if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
2452  QualType BaseAllocType = Context.getBaseElementType(AT);
2453  if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
2454  BaseAllocType->isObjCLifetimeType())
2455  return Diag(Loc, diag::err_arc_new_array_without_ownership)
2456  << BaseAllocType;
2457  }
2458  }
2459 
2460  return false;
2461 }
2462 
2465  bool &PassAlignment, FunctionDecl *&Operator,
2466  OverloadCandidateSet *AlignedCandidates, Expr *AlignArg, bool Diagnose) {
2467  OverloadCandidateSet Candidates(R.getNameLoc(),
2469  for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
2470  Alloc != AllocEnd; ++Alloc) {
2471  // Even member operator new/delete are implicitly treated as
2472  // static, so don't use AddMemberCandidate.
2473  NamedDecl *D = (*Alloc)->getUnderlyingDecl();
2474 
2475  if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
2476  S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
2477  /*ExplicitTemplateArgs=*/nullptr, Args,
2478  Candidates,
2479  /*SuppressUserConversions=*/false);
2480  continue;
2481  }
2482 
2483  FunctionDecl *Fn = cast<FunctionDecl>(D);
2484  S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
2485  /*SuppressUserConversions=*/false);
2486  }
2487 
2488  // Do the resolution.
2490  switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
2491  case OR_Success: {
2492  // Got one!
2493  FunctionDecl *FnDecl = Best->Function;
2494  if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(),
2495  Best->FoundDecl) == Sema::AR_inaccessible)
2496  return true;
2497 
2498  Operator = FnDecl;
2499  return false;
2500  }
2501 
2502  case OR_No_Viable_Function:
2503  // C++17 [expr.new]p13:
2504  // If no matching function is found and the allocated object type has
2505  // new-extended alignment, the alignment argument is removed from the
2506  // argument list, and overload resolution is performed again.
2507  if (PassAlignment) {
2508  PassAlignment = false;
2509  AlignArg = Args[1];
2510  Args.erase(Args.begin() + 1);
2511  return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2512  Operator, &Candidates, AlignArg,
2513  Diagnose);
2514  }
2515 
2516  // MSVC will fall back on trying to find a matching global operator new
2517  // if operator new[] cannot be found. Also, MSVC will leak by not
2518  // generating a call to operator delete or operator delete[], but we
2519  // will not replicate that bug.
2520  // FIXME: Find out how this interacts with the std::align_val_t fallback
2521  // once MSVC implements it.
2522  if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New &&
2523  S.Context.getLangOpts().MSVCCompat) {
2524  R.clear();
2527  // FIXME: This will give bad diagnostics pointing at the wrong functions.
2528  return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2529  Operator, /*Candidates=*/nullptr,
2530  /*AlignArg=*/nullptr, Diagnose);
2531  }
2532 
2533  if (Diagnose) {
2534  // If this is an allocation of the form 'new (p) X' for some object
2535  // pointer p (or an expression that will decay to such a pointer),
2536  // diagnose the missing inclusion of <new>.
2537  if (!R.isClassLookup() && Args.size() == 2 &&
2538  (Args[1]->getType()->isObjectPointerType() ||
2539  Args[1]->getType()->isArrayType())) {
2540  S.Diag(R.getNameLoc(), diag::err_need_header_before_placement_new)
2541  << R.getLookupName() << Range;
2542  // Listing the candidates is unlikely to be useful; skip it.
2543  return true;
2544  }
2545 
2546  // Finish checking all candidates before we note any. This checking can
2547  // produce additional diagnostics so can't be interleaved with our
2548  // emission of notes.
2549  //
2550  // For an aligned allocation, separately check the aligned and unaligned
2551  // candidates with their respective argument lists.
2554  llvm::SmallVector<Expr*, 4> AlignedArgs;
2555  if (AlignedCandidates) {
2556  auto IsAligned = [](OverloadCandidate &C) {
2557  return C.Function->getNumParams() > 1 &&
2558  C.Function->getParamDecl(1)->getType()->isAlignValT();
2559  };
2560  auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); };
2561 
2562  AlignedArgs.reserve(Args.size() + 1);
2563  AlignedArgs.push_back(Args[0]);
2564  AlignedArgs.push_back(AlignArg);
2565  AlignedArgs.append(Args.begin() + 1, Args.end());
2566  AlignedCands = AlignedCandidates->CompleteCandidates(
2567  S, OCD_AllCandidates, AlignedArgs, R.getNameLoc(), IsAligned);
2568 
2569  Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
2570  R.getNameLoc(), IsUnaligned);
2571  } else {
2572  Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
2573  R.getNameLoc());
2574  }
2575 
2576  S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call)
2577  << R.getLookupName() << Range;
2578  if (AlignedCandidates)
2579  AlignedCandidates->NoteCandidates(S, AlignedArgs, AlignedCands, "",
2580  R.getNameLoc());
2581  Candidates.NoteCandidates(S, Args, Cands, "", R.getNameLoc());
2582  }
2583  return true;
2584 
2585  case OR_Ambiguous:
2586  if (Diagnose) {
2587  Candidates.NoteCandidates(
2589  S.PDiag(diag::err_ovl_ambiguous_call)
2590  << R.getLookupName() << Range),
2591  S, OCD_AmbiguousCandidates, Args);
2592  }
2593  return true;
2594 
2595  case OR_Deleted: {
2596  if (Diagnose) {
2597  Candidates.NoteCandidates(
2599  S.PDiag(diag::err_ovl_deleted_call)
2600  << R.getLookupName() << Range),
2601  S, OCD_AllCandidates, Args);
2602  }
2603  return true;
2604  }
2605  }
2606  llvm_unreachable("Unreachable, bad result from BestViableFunction");
2607 }
2608 
2610  AllocationFunctionScope NewScope,
2611  AllocationFunctionScope DeleteScope,
2612  QualType AllocType, bool IsArray,
2613  bool &PassAlignment, MultiExprArg PlaceArgs,
2614  FunctionDecl *&OperatorNew,
2615  FunctionDecl *&OperatorDelete,
2616  bool Diagnose) {
2617  // --- Choosing an allocation function ---
2618  // C++ 5.3.4p8 - 14 & 18
2619  // 1) If looking in AFS_Global scope for allocation functions, only look in
2620  // the global scope. Else, if AFS_Class, only look in the scope of the
2621  // allocated class. If AFS_Both, look in both.
2622  // 2) If an array size is given, look for operator new[], else look for
2623  // operator new.
2624  // 3) The first argument is always size_t. Append the arguments from the
2625  // placement form.
2626 
2627  SmallVector<Expr*, 8> AllocArgs;
2628  AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size());
2629 
2630  // We don't care about the actual value of these arguments.
2631  // FIXME: Should the Sema create the expression and embed it in the syntax
2632  // tree? Or should the consumer just recalculate the value?
2633  // FIXME: Using a dummy value will interact poorly with attribute enable_if.
2634  IntegerLiteral Size(
2635  Context, llvm::APInt::getZero(Context.getTargetInfo().getPointerWidth(0)),
2637  AllocArgs.push_back(&Size);
2638 
2639  QualType AlignValT = Context.VoidTy;
2640  if (PassAlignment) {
2642  AlignValT = Context.getTypeDeclType(getStdAlignValT());
2643  }
2644  CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation());
2645  if (PassAlignment)
2646  AllocArgs.push_back(&Align);
2647 
2648  AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end());
2649 
2650  // C++ [expr.new]p8:
2651  // If the allocated type is a non-array type, the allocation
2652  // function's name is operator new and the deallocation function's
2653  // name is operator delete. If the allocated type is an array
2654  // type, the allocation function's name is operator new[] and the
2655  // deallocation function's name is operator delete[].
2657  IsArray ? OO_Array_New : OO_New);
2658 
2659  QualType AllocElemType = Context.getBaseElementType(AllocType);
2660 
2661  // Find the allocation function.
2662  {
2663  LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName);
2664 
2665  // C++1z [expr.new]p9:
2666  // If the new-expression begins with a unary :: operator, the allocation
2667  // function's name is looked up in the global scope. Otherwise, if the
2668  // allocated type is a class type T or array thereof, the allocation
2669  // function's name is looked up in the scope of T.
2670  if (AllocElemType->isRecordType() && NewScope != AFS_Global)
2671  LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl());
2672 
2673  // We can see ambiguity here if the allocation function is found in
2674  // multiple base classes.
2675  if (R.isAmbiguous())
2676  return true;
2677 
2678  // If this lookup fails to find the name, or if the allocated type is not
2679  // a class type, the allocation function's name is looked up in the
2680  // global scope.
2681  if (R.empty()) {
2682  if (NewScope == AFS_Class)
2683  return true;
2684 
2686  }
2687 
2688  if (getLangOpts().OpenCLCPlusPlus && R.empty()) {
2689  if (PlaceArgs.empty()) {
2690  Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
2691  } else {
2692  Diag(StartLoc, diag::err_openclcxx_placement_new);
2693  }
2694  return true;
2695  }
2696 
2697  assert(!R.empty() && "implicitly declared allocation functions not found");
2698  assert(!R.isAmbiguous() && "global allocation functions are ambiguous");
2699 
2700  // We do our own custom access checks below.
2701  R.suppressDiagnostics();
2702 
2703  if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment,
2704  OperatorNew, /*Candidates=*/nullptr,
2705  /*AlignArg=*/nullptr, Diagnose))
2706  return true;
2707  }
2708 
2709  // We don't need an operator delete if we're running under -fno-exceptions.
2710  if (!getLangOpts().Exceptions) {
2711  OperatorDelete = nullptr;
2712  return false;
2713  }
2714 
2715  // Note, the name of OperatorNew might have been changed from array to
2716  // non-array by resolveAllocationOverload.
2718  OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New
2719  ? OO_Array_Delete
2720  : OO_Delete);
2721 
2722  // C++ [expr.new]p19:
2723  //
2724  // If the new-expression begins with a unary :: operator, the
2725  // deallocation function's name is looked up in the global
2726  // scope. Otherwise, if the allocated type is a class type T or an
2727  // array thereof, the deallocation function's name is looked up in
2728  // the scope of T. If this lookup fails to find the name, or if
2729  // the allocated type is not a class type or array thereof, the
2730  // deallocation function's name is looked up in the global scope.
2731  LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
2732  if (AllocElemType->isRecordType() && DeleteScope != AFS_Global) {
2733  auto *RD =
2734  cast<CXXRecordDecl>(AllocElemType->castAs<RecordType>()->getDecl());
2735  LookupQualifiedName(FoundDelete, RD);
2736  }
2737  if (FoundDelete.isAmbiguous())
2738  return true; // FIXME: clean up expressions?
2739 
2740  // Filter out any destroying operator deletes. We can't possibly call such a
2741  // function in this context, because we're handling the case where the object
2742  // was not successfully constructed.
2743  // FIXME: This is not covered by the language rules yet.
2744  {
2745  LookupResult::Filter Filter = FoundDelete.makeFilter();
2746  while (Filter.hasNext()) {
2747  auto *FD = dyn_cast<FunctionDecl>(Filter.next()->getUnderlyingDecl());
2748  if (FD && FD->isDestroyingOperatorDelete())
2749  Filter.erase();
2750  }
2751  Filter.done();
2752  }
2753 
2754  bool FoundGlobalDelete = FoundDelete.empty();
2755  if (FoundDelete.empty()) {
2756  FoundDelete.clear(LookupOrdinaryName);
2757 
2758  if (DeleteScope == AFS_Class)
2759  return true;
2760 
2763  }
2764 
2765  FoundDelete.suppressDiagnostics();
2766 
2768 
2769  // Whether we're looking for a placement operator delete is dictated
2770  // by whether we selected a placement operator new, not by whether
2771  // we had explicit placement arguments. This matters for things like
2772  // struct A { void *operator new(size_t, int = 0); ... };
2773  // A *a = new A()
2774  //
2775  // We don't have any definition for what a "placement allocation function"
2776  // is, but we assume it's any allocation function whose
2777  // parameter-declaration-clause is anything other than (size_t).
2778  //
2779  // FIXME: Should (size_t, std::align_val_t) also be considered non-placement?
2780  // This affects whether an exception from the constructor of an overaligned
2781  // type uses the sized or non-sized form of aligned operator delete.
2782  bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 ||
2783  OperatorNew->isVariadic();
2784 
2785  if (isPlacementNew) {
2786  // C++ [expr.new]p20:
2787  // A declaration of a placement deallocation function matches the
2788  // declaration of a placement allocation function if it has the
2789  // same number of parameters and, after parameter transformations
2790  // (8.3.5), all parameter types except the first are
2791  // identical. [...]
2792  //
2793  // To perform this comparison, we compute the function type that
2794  // the deallocation function should have, and use that type both
2795  // for template argument deduction and for comparison purposes.
2796  QualType ExpectedFunctionType;
2797  {
2798  auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();
2799 
2800  SmallVector<QualType, 4> ArgTypes;
2801  ArgTypes.push_back(Context.VoidPtrTy);
2802  for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
2803  ArgTypes.push_back(Proto->getParamType(I));
2804 
2806  // FIXME: This is not part of the standard's rule.
2807  EPI.Variadic = Proto->isVariadic();
2808 
2809  ExpectedFunctionType
2810  = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
2811  }
2812 
2813  for (LookupResult::iterator D = FoundDelete.begin(),
2814  DEnd = FoundDelete.end();
2815  D != DEnd; ++D) {
2816  FunctionDecl *Fn = nullptr;
2817  if (FunctionTemplateDecl *FnTmpl =
2818  dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
2819  // Perform template argument deduction to try to match the
2820  // expected function type.
2821  TemplateDeductionInfo Info(StartLoc);
2822  if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
2823  Info))
2824  continue;
2825  } else
2826  Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());
2827 
2829  ExpectedFunctionType,
2830  /*AdjustExcpetionSpec*/true),
2831  ExpectedFunctionType))
2832  Matches.push_back(std::make_pair(D.getPair(), Fn));
2833  }
2834 
2835  if (getLangOpts().CUDA)
2836  EraseUnwantedCUDAMatches(getCurFunctionDecl(/*AllowLambda=*/true),
2837  Matches);
2838  } else {
2839  // C++1y [expr.new]p22:
2840  // For a non-placement allocation function, the normal deallocation
2841  // function lookup is used
2842  //
2843  // Per [expr.delete]p10, this lookup prefers a member operator delete
2844  // without a size_t argument, but prefers a non-member operator delete
2845  // with a size_t where possible (which it always is in this case).
2847  UsualDeallocFnInfo Selected = resolveDeallocationOverload(
2848  *this, FoundDelete, /*WantSize*/ FoundGlobalDelete,
2849  /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType),
2850  &BestDeallocFns);
2851  if (Selected)
2852  Matches.push_back(std::make_pair(Selected.Found, Selected.FD));
2853  else {
2854  // If we failed to select an operator, all remaining functions are viable
2855  // but ambiguous.
2856  for (auto Fn : BestDeallocFns)
2857  Matches.push_back(std::make_pair(Fn.Found, Fn.FD));
2858  }
2859  }
2860 
2861  // C++ [expr.new]p20:
2862  // [...] If the lookup finds a single matching deallocation
2863  // function, that function will be called; otherwise, no
2864  // deallocation function will be called.
2865  if (Matches.size() == 1) {
2866  OperatorDelete = Matches[0].second;
2867 
2868  // C++1z [expr.new]p23:
2869  // If the lookup finds a usual deallocation function (3.7.4.2)
2870  // with a parameter of type std::size_t and that function, considered
2871  // as a placement deallocation function, would have been
2872  // selected as a match for the allocation function, the program
2873  // is ill-formed.
2874  if (getLangOpts().CPlusPlus11 && isPlacementNew &&
2875  isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
2876  UsualDeallocFnInfo Info(*this,
2877  DeclAccessPair::make(OperatorDelete, AS_public));
2878  // Core issue, per mail to core reflector, 2016-10-09:
2879  // If this is a member operator delete, and there is a corresponding
2880  // non-sized member operator delete, this isn't /really/ a sized
2881  // deallocation function, it just happens to have a size_t parameter.
2882  bool IsSizedDelete = Info.HasSizeT;
2883  if (IsSizedDelete && !FoundGlobalDelete) {
2884  auto NonSizedDelete =
2885  resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false,
2886  /*WantAlign*/Info.HasAlignValT);
2887  if (NonSizedDelete && !NonSizedDelete.HasSizeT &&
2888  NonSizedDelete.HasAlignValT == Info.HasAlignValT)
2889  IsSizedDelete = false;
2890  }
2891 
2892  if (IsSizedDelete) {
2893  SourceRange R = PlaceArgs.empty()
2894  ? SourceRange()
2895  : SourceRange(PlaceArgs.front()->getBeginLoc(),
2896  PlaceArgs.back()->getEndLoc());
2897  Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R;
2898  if (!OperatorDelete->isImplicit())
2899  Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
2900  << DeleteName;
2901  }
2902  }
2903 
2904  CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
2905  Matches[0].first);
2906  } else if (!Matches.empty()) {
2907  // We found multiple suitable operators. Per [expr.new]p20, that means we
2908  // call no 'operator delete' function, but we should at least warn the user.
2909  // FIXME: Suppress this warning if the construction cannot throw.
2910  Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found)
2911  << DeleteName << AllocElemType;
2912 
2913  for (auto &Match : Matches)
2914  Diag(Match.second->getLocation(),
2915  diag::note_member_declared_here) << DeleteName;
2916  }
2917 
2918  return false;
2919 }
2920 
2921 /// DeclareGlobalNewDelete - Declare the global forms of operator new and
2922 /// delete. These are:
2923 /// @code
2924 /// // C++03:
2925 /// void* operator new(std::size_t) throw(std::bad_alloc);
2926 /// void* operator new[](std::size_t) throw(std::bad_alloc);
2927 /// void operator delete(void *) throw();
2928 /// void operator delete[](void *) throw();
2929 /// // C++11:
2930 /// void* operator new(std::size_t);
2931 /// void* operator new[](std::size_t);
2932 /// void operator delete(void *) noexcept;
2933 /// void operator delete[](void *) noexcept;
2934 /// // C++1y:
2935 /// void* operator new(std::size_t);
2936 /// void* operator new[](std::size_t);
2937 /// void operator delete(void *) noexcept;
2938 /// void operator delete[](void *) noexcept;
2939 /// void operator delete(void *, std::size_t) noexcept;
2940 /// void operator delete[](void *, std::size_t) noexcept;
2941 /// @endcode
2942 /// Note that the placement and nothrow forms of new are *not* implicitly
2943 /// declared. Their use requires including <new>.
2946  return;
2947 
2948  // The implicitly declared new and delete operators
2949  // are not supported in OpenCL.
2950  if (getLangOpts().OpenCLCPlusPlus)
2951  return;
2952 
2953  // C++ [basic.std.dynamic]p2:
2954  // [...] The following allocation and deallocation functions (18.4) are
2955  // implicitly declared in global scope in each translation unit of a
2956  // program
2957  //
2958  // C++03:
2959  // void* operator new(std::size_t) throw(std::bad_alloc);
2960  // void* operator new[](std::size_t) throw(std::bad_alloc);
2961  // void operator delete(void*) throw();
2962  // void operator delete[](void*) throw();
2963  // C++11:
2964  // void* operator new(std::size_t);
2965  // void* operator new[](std::size_t);
2966  // void operator delete(void*) noexcept;
2967  // void operator delete[](void*) noexcept;
2968  // C++1y:
2969  // void* operator new(std::size_t);
2970  // void* operator new[](std::size_t);
2971  // void operator delete(void*) noexcept;
2972  // void operator delete[](void*) noexcept;
2973  // void operator delete(void*, std::size_t) noexcept;
2974  // void operator delete[](void*, std::size_t) noexcept;
2975  //
2976  // These implicit declarations introduce only the function names operator
2977  // new, operator new[], operator delete, operator delete[].
2978  //
2979  // Here, we need to refer to std::bad_alloc, so we will implicitly declare
2980  // "std" or "bad_alloc" as necessary to form the exception specification.
2981  // However, we do not make these implicit declarations visible to name
2982  // lookup.
2983  if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
2984  // The "std::bad_alloc" class has not yet been declared, so build it
2985  // implicitly.
2989  &PP.getIdentifierTable().get("bad_alloc"),
2990  nullptr);
2991  getStdBadAlloc()->setImplicit(true);
2992  }
2993  if (!StdAlignValT && getLangOpts().AlignedAllocation) {
2994  // The "std::align_val_t" enum class has not yet been declared, so build it
2995  // implicitly.
2996  auto *AlignValT = EnumDecl::Create(
2998  &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true);
2999  AlignValT->setIntegerType(Context.getSizeType());
3000  AlignValT->setPromotionType(Context.getSizeType());
3001  AlignValT->setImplicit(true);
3002  StdAlignValT = AlignValT;
3003  }
3004 
3005  GlobalNewDeleteDeclared = true;
3006 
3008  QualType SizeT = Context.getSizeType();
3009 
3010  auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind,
3011  QualType Return, QualType Param) {
3013  Params.push_back(Param);
3014 
3015  // Create up to four variants of the function (sized/aligned).
3016  bool HasSizedVariant = getLangOpts().SizedDeallocation &&
3017  (Kind == OO_Delete || Kind == OO_Array_Delete);
3018  bool HasAlignedVariant = getLangOpts().AlignedAllocation;
3019 
3020  int NumSizeVariants = (HasSizedVariant ? 2 : 1);
3021  int NumAlignVariants = (HasAlignedVariant ? 2 : 1);
3022  for (int Sized = 0; Sized < NumSizeVariants; ++Sized) {
3023  if (Sized)
3024  Params.push_back(SizeT);
3025 
3026  for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) {
3027  if (Aligned)
3028  Params.push_back(Context.getTypeDeclType(getStdAlignValT()));
3029 
3031  Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params);
3032 
3033  if (Aligned)
3034  Params.pop_back();
3035  }
3036  }
3037  };
3038 
3039  DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT);
3040  DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT);
3041  DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr);
3042  DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr);
3043 }
3044 
3045 /// DeclareGlobalAllocationFunction - Declares a single implicit global
3046 /// allocation function if it doesn't already exist.
3048  QualType Return,
3049  ArrayRef<QualType> Params) {
3051 
3052  // Check if this function is already declared.
3053  DeclContext::lookup_result R = GlobalCtx->lookup(Name);
3054  for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
3055  Alloc != AllocEnd; ++Alloc) {
3056  // Only look at non-template functions, as it is the predefined,
3057  // non-templated allocation function we are trying to declare here.
3058  if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
3059  if (Func->getNumParams() == Params.size()) {
3060  llvm::SmallVector<QualType, 3> FuncParams;
3061  for (auto *P : Func->parameters())
3062  FuncParams.push_back(
3063  Context.getCanonicalType(P->getType().getUnqualifiedType()));
3064  if (llvm::makeArrayRef(FuncParams) == Params) {
3065  // Make the function visible to name lookup, even if we found it in
3066  // an unimported module. It either is an implicitly-declared global
3067  // allocation function, or is suppressing that function.
3068  Func->setVisibleDespiteOwningModule();
3069  return;
3070  }
3071  }
3072  }
3073  }
3074 
3076  /*IsVariadic=*/false, /*IsCXXMethod=*/false, /*IsBuiltin=*/true));
3077 
3078  QualType BadAllocType;
3079  bool HasBadAllocExceptionSpec
3080  = (Name.getCXXOverloadedOperator() == OO_New ||
3081  Name.getCXXOverloadedOperator() == OO_Array_New);
3082  if (HasBadAllocExceptionSpec) {
3083  if (!getLangOpts().CPlusPlus11) {
3084  BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
3085  assert(StdBadAlloc && "Must have std::bad_alloc declared");
3087  EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
3088  }
3089  if (getLangOpts().NewInfallible) {
3091  }
3092  } else {
3093  EPI.ExceptionSpec =
3094  getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
3095  }
3096 
3097  auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) {
3098  QualType FnType = Context.getFunctionType(Return, Params, EPI);
3100  Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, FnType,
3101  /*TInfo=*/nullptr, SC_None, getCurFPFeatures().isFPConstrained(), false,
3102  true);
3103  Alloc->setImplicit();
3104  // Global allocation functions should always be visible.
3106 
3107  if (HasBadAllocExceptionSpec && getLangOpts().NewInfallible)
3108  Alloc->addAttr(
3109  ReturnsNonNullAttr::CreateImplicit(Context, Alloc->getLocation()));
3110 
3111  Alloc->addAttr(VisibilityAttr::CreateImplicit(
3112  Context, LangOpts.GlobalAllocationFunctionVisibilityHidden
3113  ? VisibilityAttr::Hidden
3114  : VisibilityAttr::Default));
3115 
3117  for (QualType T : Params) {
3118  ParamDecls.push_back(ParmVarDecl::Create(
3119  Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T,
3120  /*TInfo=*/nullptr, SC_None, nullptr));
3121  ParamDecls.back()->setImplicit();
3122  }
3123  Alloc->setParams(ParamDecls);
3124  if (ExtraAttr)
3125  Alloc->addAttr(ExtraAttr);
3128  IdResolver.tryAddTopLevelDecl(Alloc, Name);
3129  };
3130 
3131  if (!LangOpts.CUDA)
3132  CreateAllocationFunctionDecl(nullptr);
3133  else {
3134  // Host and device get their own declaration so each can be
3135  // defined or re-declared independently.
3136  CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context));
3137  CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context));
3138  }
3139 }
3140 
3142  bool CanProvideSize,
3143  bool Overaligned,
3144  DeclarationName Name) {
3146 
3147  LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
3149 
3150  // FIXME: It's possible for this to result in ambiguity, through a
3151  // user-declared variadic operator delete or the enable_if attribute. We
3152  // should probably not consider those cases to be usual deallocation
3153  // functions. But for now we just make an arbitrary choice in that case.
3154  auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize,
3155  Overaligned);
3156  assert(Result.FD && "operator delete missing from global scope?");
3157  return Result.FD;
3158 }
3159 
3161  CXXRecordDecl *RD) {
3163 
3164  FunctionDecl *OperatorDelete = nullptr;
3165  if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
3166  return nullptr;
3167  if (OperatorDelete)
3168  return OperatorDelete;
3169 
3170  // If there's no class-specific operator delete, look up the global
3171  // non-array delete.
3173  Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)),
3174  Name);
3175 }
3176 
3178  DeclarationName Name,
3179  FunctionDecl *&Operator, bool Diagnose) {
3180  LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
3181  // Try to find operator delete/operator delete[] in class scope.
3182  LookupQualifiedName(Found, RD);
3183 
3184  if (Found.isAmbiguous())
3185  return true;
3186 
3187  Found.suppressDiagnostics();
3188 
3189  bool Overaligned = hasNewExtendedAlignment(*this, Context.getRecordType(RD));
3190 
3191  // C++17 [expr.delete]p10:
3192  // If the deallocation functions have class scope, the one without a
3193  // parameter of type std::size_t is selected.
3195  resolveDeallocationOverload(*this, Found, /*WantSize*/ false,
3196  /*WantAlign*/ Overaligned, &Matches);
3197 
3198  // If we could find an overload, use it.
3199  if (Matches.size() == 1) {
3200  Operator = cast<CXXMethodDecl>(Matches[0].FD);
3201 
3202  // FIXME: DiagnoseUseOfDecl?
3203  if (Operator->isDeleted()) {
3204  if (Diagnose) {
3205  Diag(StartLoc, diag::err_deleted_function_use);
3206  NoteDeletedFunction(Operator);
3207  }
3208  return true;
3209  }
3210 
3211  if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
3212  Matches[0].Found, Diagnose) == AR_inaccessible)
3213  return true;
3214 
3215  return false;
3216  }
3217 
3218  // We found multiple suitable operators; complain about the ambiguity.
3219  // FIXME: The standard doesn't say to do this; it appears that the intent
3220  // is that this should never happen.
3221  if (!Matches.empty()) {
3222  if (Diagnose) {
3223  Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
3224  << Name << RD;
3225  for (auto &Match : Matches)
3226  Diag(Match.FD->getLocation(), diag::note_member_declared_here) << Name;
3227  }
3228  return true;
3229  }
3230 
3231  // We did find operator delete/operator delete[] declarations, but
3232  // none of them were suitable.
3233  if (!Found.empty()) {
3234  if (Diagnose) {
3235  Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
3236  << Name << RD;
3237 
3238  for (NamedDecl *D : Found)
3239  Diag(D->getUnderlyingDecl()->getLocation(),
3240  diag::note_member_declared_here) << Name;
3241  }
3242  return true;
3243  }
3244 
3245  Operator = nullptr;
3246  return false;
3247 }
3248 
3249 namespace {
3250 /// Checks whether delete-expression, and new-expression used for
3251 /// initializing deletee have the same array form.
3252 class MismatchingNewDeleteDetector {
3253 public:
3254  enum MismatchResult {
3255  /// Indicates that there is no mismatch or a mismatch cannot be proven.
3256  NoMismatch,
3257  /// Indicates that variable is initialized with mismatching form of \a new.
3258  VarInitMismatches,
3259  /// Indicates that member is initialized with mismatching form of \a new.
3260  MemberInitMismatches,
3261  /// Indicates that 1 or more constructors' definitions could not been
3262  /// analyzed, and they will be checked again at the end of translation unit.
3263  AnalyzeLater
3264  };
3265 
3266  /// \param EndOfTU True, if this is the final analysis at the end of
3267  /// translation unit. False, if this is the initial analysis at the point
3268  /// delete-expression was encountered.
3269  explicit MismatchingNewDeleteDetector(bool EndOfTU)
3270  : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU),
3271  HasUndefinedConstructors(false) {}
3272 
3273  /// Checks whether pointee of a delete-expression is initialized with
3274  /// matching form of new-expression.
3275  ///
3276  /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the
3277  /// point where delete-expression is encountered, then a warning will be
3278  /// issued immediately. If return value is \c AnalyzeLater at the point where
3279  /// delete-expression is seen, then member will be analyzed at the end of
3280  /// translation unit. \c AnalyzeLater is returned iff at least one constructor
3281  /// couldn't be analyzed. If at least one constructor initializes the member
3282  /// with matching type of new, the return value is \c NoMismatch.
3283  MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE);
3284  /// Analyzes a class member.
3285  /// \param Field Class member to analyze.
3286  /// \param DeleteWasArrayForm Array form-ness of the delete-expression used
3287  /// for deleting the \p Field.
3288  MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm);
3289  FieldDecl *Field;
3290  /// List of mismatching new-expressions used for initialization of the pointee
3292  /// Indicates whether delete-expression was in array form.
3293  bool IsArrayForm;
3294 
3295 private:
3296  const bool EndOfTU;
3297  /// Indicates that there is at least one constructor without body.
3298  bool HasUndefinedConstructors;
3299  /// Returns \c CXXNewExpr from given initialization expression.
3300  /// \param E Expression used for initializing pointee in delete-expression.
3301  /// E can be a single-element \c InitListExpr consisting of new-expression.
3302  const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E);
3303  /// Returns whether member is initialized with mismatching form of
3304  /// \c new either by the member initializer or in-class initialization.
3305  ///
3306  /// If bodies of all constructors are not visible at the end of translation
3307  /// unit or at least one constructor initializes member with the matching
3308  /// form of \c new, mismatch cannot be proven, and this function will return
3309  /// \c NoMismatch.
3310  MismatchResult analyzeMemberExpr(const MemberExpr *ME);
3311  /// Returns whether variable is initialized with mismatching form of
3312  /// \c new.
3313  ///
3314  /// If variable is initialized with matching form of \c new or variable is not
3315  /// initialized with a \c new expression, this function will return true.
3316  /// If variable is initialized with mismatching form of \c new, returns false.
3317  /// \param D Variable to analyze.
3318  bool hasMatchingVarInit(const DeclRefExpr *D);
3319  /// Checks whether the constructor initializes pointee with mismatching
3320  /// form of \c new.
3321  ///
3322  /// Returns true, if member is initialized with matching form of \c new in
3323  /// member initializer list. Returns false, if member is initialized with the
3324  /// matching form of \c new in this constructor's initializer or given
3325  /// constructor isn't defined at the point where delete-expression is seen, or
3326  /// member isn't initialized by the constructor.
3327  bool hasMatchingNewInCtor(const CXXConstructorDecl *CD);
3328  /// Checks whether member is initialized with matching form of
3329  /// \c new in member initializer list.
3330  bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI);
3331  /// Checks whether member is initialized with mismatching form of \c new by
3332  /// in-class initializer.
3333  MismatchResult analyzeInClassInitializer();
3334 };
3335 }
3336 
3337 MismatchingNewDeleteDetector::MismatchResult
3338 MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) {
3339  NewExprs.clear();
3340  assert(DE && "Expected delete-expression");
3341  IsArrayForm = DE->isArrayForm();
3342  const Expr *E = DE->getArgument()->IgnoreParenImpCasts();
3343  if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) {
3344  return analyzeMemberExpr(ME);
3345  } else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) {
3346  if (!hasMatchingVarInit(D))
3347  return VarInitMismatches;
3348  }
3349  return NoMismatch;
3350 }
3351 
3352 const CXXNewExpr *
3353 MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) {
3354  assert(E != nullptr && "Expected a valid initializer expression");
3355  E = E->IgnoreParenImpCasts();
3356  if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) {
3357  if (ILE->getNumInits() == 1)
3358  E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts());
3359  }
3360 
3361  return dyn_cast_or_null<const CXXNewExpr>(E);
3362 }
3363 
3364 bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit(
3365  const CXXCtorInitializer *CI) {
3366  const CXXNewExpr *NE = nullptr;
3367  if (Field == CI->getMember() &&
3368  (NE = getNewExprFromInitListOrExpr(CI->getInit()))) {
3369  if (NE->isArray() == IsArrayForm)
3370  return true;
3371  else
3372  NewExprs.push_back(NE);
3373  }
3374  return false;
3375 }
3376 
3377 bool MismatchingNewDeleteDetector::hasMatchingNewInCtor(
3378  const CXXConstructorDecl *CD) {
3379  if (CD->isImplicit())
3380  return false;
3381  const FunctionDecl *Definition = CD;
3382  if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) {
3383  HasUndefinedConstructors = true;
3384  return EndOfTU;
3385  }
3386  for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) {
3387  if (hasMatchingNewInCtorInit(CI))
3388  return true;
3389  }
3390  return false;
3391 }
3392 
3393 MismatchingNewDeleteDetector::MismatchResult
3394 MismatchingNewDeleteDetector::analyzeInClassInitializer() {
3395  assert(Field != nullptr && "This should be called only for members");
3396  const Expr *InitExpr = Field->getInClassInitializer();
3397  if (!InitExpr)
3398  return EndOfTU ? NoMismatch : AnalyzeLater;
3399  if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) {
3400  if (NE->isArray() != IsArrayForm) {
3401  NewExprs.push_back(NE);
3402  return MemberInitMismatches;
3403  }
3404  }
3405  return NoMismatch;
3406 }
3407 
3408 MismatchingNewDeleteDetector::MismatchResult
3409 MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field,
3410  bool DeleteWasArrayForm) {
3411  assert(Field != nullptr && "Analysis requires a valid class member.");
3412  this->Field = Field;
3413  IsArrayForm = DeleteWasArrayForm;
3414  const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent());
3415  for (const auto *CD : RD->ctors()) {
3416  if (hasMatchingNewInCtor(CD))
3417  return NoMismatch;
3418  }
3419  if (HasUndefinedConstructors)
3420  return EndOfTU ? NoMismatch : AnalyzeLater;
3421  if (!NewExprs.empty())
3422  return MemberInitMismatches;
3423  return Field->hasInClassInitializer() ? analyzeInClassInitializer()
3424  : NoMismatch;
3425 }
3426 
3427 MismatchingNewDeleteDetector::MismatchResult
3428 MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) {
3429  assert(ME != nullptr && "Expected a member expression");
3430  if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3431  return analyzeField(F, IsArrayForm);
3432  return NoMismatch;
3433 }
3434 
3435 bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) {
3436  const CXXNewExpr *NE = nullptr;
3437  if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) {
3438  if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) &&
3439  NE->isArray() != IsArrayForm) {
3440  NewExprs.push_back(NE);
3441  }
3442  }
3443  return NewExprs.empty();
3444 }
3445 
3446 static void
3448  const MismatchingNewDeleteDetector &Detector) {
3449  SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc);
3450  FixItHint H;
3451  if (!Detector.IsArrayForm)
3452  H = FixItHint::CreateInsertion(EndOfDelete, "[]");
3453  else {
3455  DeleteLoc, tok::l_square, SemaRef.getSourceManager(),
3456  SemaRef.getLangOpts(), true);
3457  if (RSquare.isValid())
3458  H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare));
3459  }
3460  SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new)
3461  << Detector.IsArrayForm << H;
3462 
3463  for (const auto *NE : Detector.NewExprs)
3464  SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here)
3465  << Detector.IsArrayForm;
3466 }
3467 
3468 void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) {
3469  if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation()))
3470  return;
3471  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false);
3472  switch (Detector.analyzeDeleteExpr(DE)) {
3473  case MismatchingNewDeleteDetector::VarInitMismatches:
3474  case MismatchingNewDeleteDetector::MemberInitMismatches: {
3475  DiagnoseMismatchedNewDelete(*this, DE->getBeginLoc(), Detector);
3476  break;
3477  }
3478  case MismatchingNewDeleteDetector::AnalyzeLater: {
3479  DeleteExprs[Detector.Field].push_back(
3480  std::make_pair(DE->getBeginLoc(), DE->isArrayForm()));
3481  break;
3482  }
3483  case MismatchingNewDeleteDetector::NoMismatch:
3484  break;
3485  }
3486 }
3487 
3488 void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
3489  bool DeleteWasArrayForm) {
3490  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true);
3491  switch (Detector.analyzeField(Field, DeleteWasArrayForm)) {
3492  case MismatchingNewDeleteDetector::VarInitMismatches:
3493  llvm_unreachable("This analysis should have been done for class members.");
3494  case MismatchingNewDeleteDetector::AnalyzeLater:
3495  llvm_unreachable("Analysis cannot be postponed any point beyond end of "
3496  "translation unit.");
3497  case MismatchingNewDeleteDetector::MemberInitMismatches:
3498  DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector);
3499  break;
3500  case MismatchingNewDeleteDetector::NoMismatch:
3501  break;
3502  }
3503 }
3504 
3505 /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
3506 /// @code ::delete ptr; @endcode
3507 /// or
3508 /// @code delete [] ptr; @endcode
3509 ExprResult
3510 Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
3511  bool ArrayForm, Expr *ExE) {
3512  // C++ [expr.delete]p1:
3513  // The operand shall have a pointer type, or a class type having a single
3514  // non-explicit conversion function to a pointer type. The result has type
3515  // void.
3516  //
3517  // DR599 amends "pointer type" to "pointer to object type" in both cases.
3518 
3519  ExprResult Ex = ExE;
3520  FunctionDecl *OperatorDelete = nullptr;
3521  bool ArrayFormAsWritten = ArrayForm;
3522  bool UsualArrayDeleteWantsSize = false;
3523 
3524  if (!Ex.get()->isTypeDependent()) {
3525  // Perform lvalue-to-rvalue cast, if needed.
3526  Ex = DefaultLvalueConversion(Ex.get());
3527  if (Ex.isInvalid())
3528  return ExprError();
3529 
3530  QualType Type = Ex.get()->getType();
3531 
3532  class DeleteConverter : public ContextualImplicitConverter {
3533  public:
3534  DeleteConverter() : ContextualImplicitConverter(false, true) {}
3535 
3536  bool match(QualType ConvType) override {
3537  // FIXME: If we have an operator T* and an operator void*, we must pick
3538  // the operator T*.
3539  if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
3540  if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
3541  return true;
3542  return false;
3543  }
3544 
3545  SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
3546  QualType T) override {
3547  return S.Diag(Loc, diag::err_delete_operand) << T;
3548  }
3549 
3550  SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
3551  QualType T) override {
3552  return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
3553  }
3554 
3555  SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
3556  QualType T,
3557  QualType ConvTy) override {
3558  return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
3559  }
3560 
3561  SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
3562  QualType ConvTy) override {
3563  return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3564  << ConvTy;
3565  }
3566 
3567  SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
3568  QualType T) override {
3569  return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
3570  }
3571 
3572  SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
3573  QualType ConvTy) override {
3574  return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3575  << ConvTy;
3576  }
3577 
3578  SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
3579  QualType T,
3580  QualType ConvTy) override {
3581  llvm_unreachable("conversion functions are permitted");
3582  }
3583  } Converter;
3584 
3585  Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
3586  if (Ex.isInvalid())
3587  return ExprError();
3588  Type = Ex.get()->getType();
3589  if (!Converter.match(Type))
3590  // FIXME: PerformContextualImplicitConversion should return ExprError
3591  // itself in this case.
3592  return ExprError();
3593 
3594  QualType Pointee = Type->castAs<PointerType>()->getPointeeType();
3595  QualType PointeeElem = Context.getBaseElementType(Pointee);
3596 
3597  if (Pointee.getAddressSpace() != LangAS::Default &&
3598  !getLangOpts().OpenCLCPlusPlus)
3599  return Diag(Ex.get()->getBeginLoc(),
3600  diag::err_address_space_qualified_delete)
3601  << Pointee.getUnqualifiedType()
3603 
3604  CXXRecordDecl *PointeeRD = nullptr;
3605  if (Pointee->isVoidType() && !isSFINAEContext()) {
3606  // The C++ standard bans deleting a pointer to a non-object type, which
3607  // effectively bans deletion of "void*". However, most compilers support
3608  // this, so we treat it as a warning unless we're in a SFINAE context.
3609  Diag(StartLoc, diag::ext_delete_void_ptr_operand)
3610  << Type << Ex.get()->getSourceRange();
3611  } else if (Pointee->isFunctionType() || Pointee->isVoidType() ||
3612  Pointee->isSizelessType()) {
3613  return ExprError(Diag(StartLoc, diag::err_delete_operand)
3614  << Type << Ex.get()->getSourceRange());
3615  } else if (!Pointee->isDependentType()) {
3616  // FIXME: This can result in errors if the definition was imported from a
3617  // module but is hidden.
3618  if (!RequireCompleteType(StartLoc, Pointee,
3619  diag::warn_delete_incomplete, Ex.get())) {
3620  if (const RecordType *RT = PointeeElem->getAs<RecordType>())
3621  PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
3622  }
3623  }
3624 
3625  if (Pointee->isArrayType() && !ArrayForm) {
3626  Diag(StartLoc, diag::warn_delete_array_type)
3627  << Type << Ex.get()->getSourceRange()
3628  << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]");
3629  ArrayForm = true;
3630  }
3631 
3633  ArrayForm ? OO_Array_Delete : OO_Delete);
3634 
3635  if (PointeeRD) {
3636  if (!UseGlobal &&
3637  FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
3638  OperatorDelete))
3639  return ExprError();
3640 
3641  // If we're allocating an array of records, check whether the
3642  // usual operator delete[] has a size_t parameter.
3643  if (ArrayForm) {
3644  // If the user specifically asked to use the global allocator,
3645  // we'll need to do the lookup into the class.
3646  if (UseGlobal)
3647  UsualArrayDeleteWantsSize =
3648  doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);
3649 
3650  // Otherwise, the usual operator delete[] should be the
3651  // function we just found.
3652  else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
3653  UsualArrayDeleteWantsSize =
3654  UsualDeallocFnInfo(*this,
3655  DeclAccessPair::make(OperatorDelete, AS_public))
3656  .HasSizeT;
3657  }
3658 
3659  if (!PointeeRD->hasIrrelevantDestructor())
3660  if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3661  MarkFunctionReferenced(StartLoc,
3662  const_cast<CXXDestructorDecl*>(Dtor));
3663  if (DiagnoseUseOfDecl(Dtor, StartLoc))
3664  return ExprError();
3665  }
3666 
3667  CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc,
3668  /*IsDelete=*/true, /*CallCanBeVirtual=*/true,
3669  /*WarnOnNonAbstractTypes=*/!ArrayForm,
3670  SourceLocation());
3671  }
3672 
3673  if (!OperatorDelete) {
3674  if (getLangOpts().OpenCLCPlusPlus) {
3675  Diag(StartLoc, diag::err_openclcxx_not_supported) << "default delete";
3676  return ExprError();
3677  }
3678 
3679  bool IsComplete = isCompleteType(StartLoc, Pointee);
3680  bool CanProvideSize =
3681  IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize ||
3682  Pointee.isDestructedType());
3683  bool Overaligned = hasNewExtendedAlignment(*this, Pointee);
3684 
3685  // Look for a global declaration.
3686  OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize,
3687  Overaligned, DeleteName);
3688  }
3689 
3690  MarkFunctionReferenced(StartLoc, OperatorDelete);
3691 
3692  // Check access and ambiguity of destructor if we're going to call it.
3693  // Note that this is required even for a virtual delete.
3694  bool IsVirtualDelete = false;
3695  if (PointeeRD) {
3696  if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3697  CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
3698  PDiag(diag::err_access_dtor) << PointeeElem);
3699  IsVirtualDelete = Dtor->isVirtual();
3700  }
3701  }
3702 
3703  DiagnoseUseOfDecl(OperatorDelete, StartLoc);
3704 
3705  // Convert the operand to the type of the first parameter of operator
3706  // delete. This is only necessary if we selected a destroying operator
3707  // delete that we are going to call (non-virtually); converting to void*
3708  // is trivial and left to AST consumers to handle.
3709  QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
3710  if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) {
3711  Qualifiers Qs = Pointee.getQualifiers();
3712  if (Qs.hasCVRQualifiers()) {
3713  // Qualifiers are irrelevant to this conversion; we're only looking
3714  // for access and ambiguity.
3715  Qs.removeCVRQualifiers();
3716  QualType Unqual = Context.getPointerType(
3718  Ex = ImpCastExprToType(Ex.get(), Unqual, CK_NoOp);
3719  }
3720  Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing);
3721  if (Ex.isInvalid())
3722  return ExprError();
3723  }
3724  }
3725 
3726  CXXDeleteExpr *Result = new (Context) CXXDeleteExpr(
3727  Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
3728  UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
3729  AnalyzeDeleteExprMismatch(Result);
3730  return Result;
3731 }
3732 
3734  bool IsDelete,
3735  FunctionDecl *&Operator) {
3736 
3738  IsDelete ? OO_Delete : OO_New);
3739 
3740  LookupResult R(S, NewName, TheCall->getBeginLoc(), Sema::LookupOrdinaryName);
3742  assert(!R.empty() && "implicitly declared allocation functions not found");
3743  assert(!R.isAmbiguous() && "global allocation functions are ambiguous");
3744 
3745  // We do our own custom access checks below.
3746  R.suppressDiagnostics();
3747 
3748  SmallVector<Expr *, 8> Args(TheCall->arg_begin(), TheCall->arg_end());
3749  OverloadCandidateSet Candidates(R.getNameLoc(),
3751  for (LookupResult::iterator FnOvl = R.begin(), FnOvlEnd = R.end();
3752  FnOvl != FnOvlEnd; ++FnOvl) {
3753  // Even member operator new/delete are implicitly treated as
3754  // static, so don't use AddMemberCandidate.
3755  NamedDecl *D = (*FnOvl)->getUnderlyingDecl();
3756 
3757  if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
3758  S.AddTemplateOverloadCandidate(FnTemplate, FnOvl.getPair(),
3759  /*ExplicitTemplateArgs=*/nullptr, Args,
3760  Candidates,
3761  /*SuppressUserConversions=*/false);
3762  continue;
3763  }
3764 
3765  FunctionDecl *Fn = cast<FunctionDecl>(D);
3766  S.AddOverloadCandidate(Fn, FnOvl.getPair(), Args, Candidates,
3767  /*SuppressUserConversions=*/false);
3768  }
3769 
3770  SourceRange Range = TheCall->getSourceRange();
3771 
3772  // Do the resolution.
3774  switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
3775  case OR_Success: {
3776  // Got one!
3777  FunctionDecl *FnDecl = Best->Function;
3778  assert(R.getNamingClass() == nullptr &&
3779  "class members should not be considered");
3780 
3781  if (!FnDecl->isReplaceableGlobalAllocationFunction()) {
3782  S.Diag(R.getNameLoc(), diag::err_builtin_operator_new_delete_not_usual)
3783  << (IsDelete ? 1 : 0) << Range;
3784  S.Diag(FnDecl->getLocation(), diag::note_non_usual_function_declared_here)
3785  << R.getLookupName() << FnDecl->getSourceRange();
3786  return true;
3787  }
3788 
3789  Operator = FnDecl;
3790  return false;
3791  }
3792 
3793  case OR_No_Viable_Function:
3794  Candidates.NoteCandidates(
3796  S.PDiag(diag::err_ovl_no_viable_function_in_call)
3797  << R.getLookupName() << Range),
3798  S, OCD_AllCandidates, Args);
3799  return true;
3800 
3801  case OR_Ambiguous:
3802  Candidates.NoteCandidates(
3804  S.PDiag(diag::err_ovl_ambiguous_call)
3805  << R.getLookupName() << Range),
3806  S, OCD_AmbiguousCandidates, Args);
3807  return true;
3808 
3809  case OR_Deleted: {
3810  Candidates.NoteCandidates(
3811  PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call)
3812  << R.getLookupName() << Range),
3813  S, OCD_AllCandidates, Args);
3814  return true;
3815  }
3816  }
3817  llvm_unreachable("Unreachable, bad result from BestViableFunction");
3818 }
3819 
3820 ExprResult
3821 Sema::SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult,
3822  bool IsDelete) {
3823  CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
3824  if (!getLangOpts().CPlusPlus) {
3825  Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language)
3826  << (IsDelete ? "__builtin_operator_delete" : "__builtin_operator_new")
3827  << "C++";
3828  return ExprError();
3829  }
3830  // CodeGen assumes it can find the global new and delete to call,
3831  // so ensure that they are declared.
3833 
3834  FunctionDecl *OperatorNewOrDelete = nullptr;
3835  if (resolveBuiltinNewDeleteOverload(*this, TheCall, IsDelete,
3836  OperatorNewOrDelete))
3837  return ExprError();
3838  assert(OperatorNewOrDelete && "should be found");
3839 
3840  DiagnoseUseOfDecl(OperatorNewOrDelete, TheCall->getExprLoc());
3841  MarkFunctionReferenced(TheCall->getExprLoc(), OperatorNewOrDelete);
3842 
3843  TheCall->setType(OperatorNewOrDelete->getReturnType());
3844  for (unsigned i = 0; i != TheCall->getNumArgs(); ++i) {
3845  QualType ParamTy = OperatorNewOrDelete->getParamDecl(i)->getType();
3846  InitializedEntity Entity =
3849  Entity, TheCall->getArg(i)->getBeginLoc(), TheCall->getArg(i));
3850  if (Arg.isInvalid())
3851  return ExprError();
3852  TheCall->setArg(i, Arg.get());
3853  }
3854  auto Callee = dyn_cast<ImplicitCastExpr>(TheCall->getCallee());
3855  assert(Callee && Callee->getCastKind() == CK_BuiltinFnToFnPtr &&
3856  "Callee expected to be implicit cast to a builtin function pointer");
3857  Callee->setType(OperatorNewOrDelete->getType());
3858 
3859  return TheCallResult;
3860 }
3861 
3863  bool IsDelete, bool CallCanBeVirtual,
3864  bool WarnOnNonAbstractTypes,
3865  SourceLocation DtorLoc) {
3866  if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext())
3867  return;
3868 
3869  // C++ [expr.delete]p3:
3870  // In the first alternative (delete object), if the static type of the
3871  // object to be deleted is different from its dynamic type, the static
3872  // type shall be a base class of the dynamic type of the object to be
3873  // deleted and the static type shall have a virtual destructor or the
3874  // behavior is undefined.
3875  //
3876  const CXXRecordDecl *PointeeRD = dtor->getParent();
3877  // Note: a final class cannot be derived from, no issue there
3878  if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>())
3879  return;
3880 
3881  // If the superclass is in a system header, there's nothing that can be done.
3882  // The `delete` (where we emit the warning) can be in a system header,
3883  // what matters for this warning is where the deleted type is defined.
3884  if (getSourceManager().isInSystemHeader(PointeeRD->getLocation()))
3885  return;
3886 
3887  QualType ClassType = dtor->getThisType()->getPointeeType();
3888  if (PointeeRD->isAbstract()) {
3889  // If the class is abstract, we warn by default, because we're
3890  // sure the code has undefined behavior.
3891  Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1)
3892  << ClassType;
3893  } else if (WarnOnNonAbstractTypes) {
3894  // Otherwise, if this is not an array delete, it's a bit suspect,
3895  // but not necessarily wrong.
3896  Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1)
3897  << ClassType;
3898  }
3899  if (!IsDelete) {
3900  std::string TypeStr;
3901  ClassType.getAsStringInternal(TypeStr, getPrintingPolicy());
3902  Diag(DtorLoc, diag::note_delete_non_virtual)
3903  << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::");
3904  }
3905 }
3906 
3908  SourceLocation StmtLoc,
3909  ConditionKind CK) {
3910  ExprResult E =
3911  CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK);
3912  if (E.isInvalid())
3913  return ConditionError();
3914  return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc),
3916 }
3917 
3918 /// Check the use of the given variable as a C++ condition in an if,
3919 /// while, do-while, or switch statement.
3921  SourceLocation StmtLoc,
3922  ConditionKind CK) {
3923  if (ConditionVar->isInvalidDecl())
3924  return ExprError();
3925 
3926  QualType T = ConditionVar->getType();
3927 
3928  // C++ [stmt.select]p2:
3929  // The declarator shall not specify a function or an array.
3930  if (T->isFunctionType())
3931  return ExprError(Diag(ConditionVar->getLocation(),
3932  diag::err_invalid_use_of_function_type)
3933  << ConditionVar->getSourceRange());
3934  else if (T->isArrayType())
3935  return ExprError(Diag(ConditionVar->getLocation(),
3936  diag::err_invalid_use_of_array_type)
3937  << ConditionVar->getSourceRange());
3938 
3940  ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue,
3941  ConditionVar->getLocation());
3942 
3943  switch (CK) {
3945  return CheckBooleanCondition(StmtLoc, Condition.get());
3946 
3948  return CheckBooleanCondition(StmtLoc, Condition.get(), true);
3949 
3950  case ConditionKind::Switch:
3951  return CheckSwitchCondition(StmtLoc, Condition.get());
3952  }
3953 
3954  llvm_unreachable("unexpected condition kind");
3955 }
3956 
3957 /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
3958 ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) {
3959  // C++11 6.4p4:
3960  // The value of a condition that is an initialized declaration in a statement
3961  // other than a switch statement is the value of the declared variable
3962  // implicitly converted to type bool. If that conversion is ill-formed, the
3963  // program is ill-formed.
3964  // The value of a condition that is an expression is the value of the
3965  // expression, implicitly converted to bool.
3966  //
3967  // C++2b 8.5.2p2
3968  // If the if statement is of the form if constexpr, the value of the condition
3969  // is contextually converted to bool and the converted expression shall be
3970  // a constant expression.
3971  //
3972 
3974  if (!IsConstexpr || E.isInvalid() || E.get()->isValueDependent())
3975  return E;
3976 
3977  // FIXME: Return this value to the caller so they don't need to recompute it.
3978  llvm::APSInt Cond;
3980  E.get(), &Cond,
3981  diag::err_constexpr_if_condition_expression_is_not_constant);
3982  return E;
3983 }
3984 
3985 /// Helper function to determine whether this is the (deprecated) C++
3986 /// conversion from a string literal to a pointer to non-const char or
3987 /// non-const wchar_t (for narrow and wide string literals,
3988 /// respectively).
3989 bool
3991  // Look inside the implicit cast, if it exists.
3992  if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
3993  From = Cast->getSubExpr();
3994 
3995  // A string literal (2.13.4) that is not a wide string literal can
3996  // be converted to an rvalue of type "pointer to char"; a wide
3997  // string literal can be converted to an rvalue of type "pointer
3998  // to wchar_t" (C++ 4.2p2).
3999  if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
4000  if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
4001  if (const BuiltinType *ToPointeeType
4002  = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
4003  // This conversion is considered only when there is an
4004  // explicit appropriate pointer target type (C++ 4.2p2).
4005  if (!ToPtrType->getPointeeType().hasQualifiers()) {
4006  switch (StrLit->getKind()) {
4007  case StringLiteral::UTF8:
4008  case StringLiteral::UTF16:
4009  case StringLiteral::UTF32:
4010  // We don't allow UTF literals to be implicitly converted
4011  break;
4012  case StringLiteral::Ascii:
4013  return (ToPointeeType->getKind() == BuiltinType::Char_U ||
4014  ToPointeeType->getKind() == BuiltinType::Char_S);
4015  case StringLiteral::Wide:
4017  QualType(ToPointeeType, 0));
4018  }
4019  }
4020  }
4021 
4022  return false;
4023 }
4024 
4026  SourceLocation CastLoc,
4027  QualType Ty,
4028  CastKind Kind,
4029  CXXMethodDecl *Method,
4030  DeclAccessPair FoundDecl,
4031  bool HadMultipleCandidates,
4032  Expr *From) {
4033  switch (Kind) {
4034  default: llvm_unreachable("Unhandled cast kind!");
4035  case CK_ConstructorConversion: {
4036  CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
4037  SmallVector<Expr*, 8> ConstructorArgs;
4038 
4039  if (S.RequireNonAbstractType(CastLoc, Ty,
4040  diag::err_allocation_of_abstract_type))
4041  return ExprError();
4042 
4043  if (S.CompleteConstructorCall(Constructor, Ty, From, CastLoc,
4044  ConstructorArgs))
4045  return ExprError();
4046 
4047  S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl,
4049  if (S.DiagnoseUseOfDecl(Method, CastLoc))
4050  return ExprError();
4051 
4052  ExprResult Result = S.BuildCXXConstructExpr(
4053  CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method),
4054  ConstructorArgs, HadMultipleCandidates,
4055  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4057  if (Result.isInvalid())
4058  return ExprError();
4059 
4060  return S.MaybeBindToTemporary(Result.getAs<Expr>());
4061  }
4062 
4063  case CK_UserDefinedConversion: {
4064  assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");
4065 
4066  S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
4067  if (S.DiagnoseUseOfDecl(Method, CastLoc))
4068  return ExprError();
4069 
4070  // Create an implicit call expr that calls it.
4071  CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
4072  ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
4073  HadMultipleCandidates);
4074  if (Result.isInvalid())
4075  return ExprError();
4076  // Record usage of conversion in an implicit cast.
4077  Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
4078  CK_UserDefinedConversion, Result.get(),
4079  nullptr, Result.get()->getValueKind(),
4080  S.CurFPFeatureOverrides());
4081 
4082  return S.MaybeBindToTemporary(Result.get());
4083  }
4084  }
4085 }
4086 
4087 /// PerformImplicitConversion - Perform an implicit conversion of the
4088 /// expression From to the type ToType using the pre-computed implicit
4089 /// conversion sequence ICS. Returns the converted
4090 /// expression. Action is the kind of conversion we're performing,
4091 /// used in the error message.
4092 ExprResult
4094  const ImplicitConversionSequence &ICS,
4095  AssignmentAction Action,
4096  CheckedConversionKind CCK) {
4097  // C++ [over.match.oper]p7: [...] operands of class type are converted [...]
4098  if (CCK == CCK_ForBuiltinOverloadedOp && !From->getType()->isRecordType())
4099  return From;
4100 
4101  switch (ICS.getKind()) {
4103  ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
4104  Action, CCK);
4105  if (Res.isInvalid())
4106  return ExprError();
4107  From = Res.get();
4108  break;
4109  }
4110 
4112 
4115  QualType BeforeToType;
4116  assert(FD && "no conversion function for user-defined conversion seq");
4117  if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
4118  CastKind = CK_UserDefinedConversion;
4119 
4120  // If the user-defined conversion is specified by a conversion function,
4121  // the initial standard conversion sequence converts the source type to
4122  // the implicit object parameter of the conversion function.
4123  BeforeToType = Context.getTagDeclType(Conv->getParent());
4124  } else {
4125  const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
4126  CastKind = CK_ConstructorConversion;
4127  // Do no conversion if dealing with ... for the first conversion.
4128  if (!ICS.UserDefined.EllipsisConversion) {
4129  // If the user-defined conversion is specified by a constructor, the
4130  // initial standard conversion sequence converts the source type to
4131  // the type required by the argument of the constructor
4132  BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
4133  }
4134  }
4135  // Watch out for ellipsis conversion.
4136  if (!ICS.UserDefined.EllipsisConversion) {
4137  ExprResult Res =
4138  PerformImplicitConversion(From, BeforeToType,
4140  CCK);
4141  if (Res.isInvalid())
4142  return ExprError();
4143  From = Res.get();
4144  }
4145 
4146  ExprResult CastArg = BuildCXXCastArgument(
4147  *this, From->getBeginLoc(), ToType.getNonReferenceType(), CastKind,
4148  cast<CXXMethodDecl>(FD), ICS.UserDefined.FoundConversionFunction,
4150 
4151  if (CastArg.isInvalid())
4152  return ExprError();
4153 
4154  From = CastArg.get();
4155 
4156  // C++ [over.match.oper]p7:
4157  // [...] the second standard conversion sequence of a user-defined
4158  // conversion sequence is not applied.
4159  if (CCK == CCK_ForBuiltinOverloadedOp)
4160  return From;
4161 
4162  return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
4163  AA_Converting, CCK);
4164  }
4165 
4167  ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
4168  PDiag(diag::err_typecheck_ambiguous_condition)
4169  << From->getSourceRange());
4170  return ExprError();
4171 
4173  llvm_unreachable("Cannot perform an ellipsis conversion");
4174 
4176  Sema::AssignConvertType ConvTy =
4177  CheckAssignmentConstraints(From->getExprLoc(), ToType, From->getType());
4178  bool Diagnosed = DiagnoseAssignmentResult(
4179  ConvTy == Compatible ? Incompatible : ConvTy, From->getExprLoc(),
4180  ToType, From->getType(), From, Action);
4181  assert(Diagnosed && "failed to diagnose bad conversion"); (void)Diagnosed;
4182  return ExprError();
4183  }
4184 
4185  // Everything went well.
4186  return From;
4187 }
4188 
4189 /// PerformImplicitConversion - Perform an implicit conversion of the
4190 /// expression From to the type ToType by following the standard
4191 /// conversion sequence SCS. Returns the converted
4192 /// expression. Flavor is the context in which we're performing this
4193 /// conversion, for use in error messages.
4194 ExprResult
4196  const StandardConversionSequence& SCS,
4197  AssignmentAction Action,
4198  CheckedConversionKind CCK) {
4199  bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);
4200 
4201  // Overall FIXME: we are recomputing too many types here and doing far too
4202  // much extra work. What this means is that we need to keep track of more
4203  // information that is computed when we try the implicit conversion initially,
4204  // so that we don't need to recompute anything here.
4205  QualType FromType = From->getType();
4206 
4207  if (SCS.CopyConstructor) {
4208  // FIXME: When can ToType be a reference type?
4209  assert(!ToType->isReferenceType());
4210  if (SCS.Second == ICK_Derived_To_Base) {
4211  SmallVector<Expr*, 8> ConstructorArgs;
4213  cast<CXXConstructorDecl>(SCS.CopyConstructor), ToType, From,
4214  /*FIXME:ConstructLoc*/ SourceLocation(), ConstructorArgs))
4215  return ExprError();
4216  return BuildCXXConstructExpr(
4217  /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
4219  ConstructorArgs, /*HadMultipleCandidates*/ false,
4220  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4222  }
4223  return BuildCXXConstructExpr(
4224  /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
4226  From, /*HadMultipleCandidates*/ false,
4227  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4229  }
4230 
4231  // Resolve overloaded function references.
4232  if (Context.hasSameType(FromType, Context.OverloadTy)) {
4233  DeclAccessPair Found;
4235  true, Found);
4236  if (!Fn)
4237  return ExprError();
4238 
4239  if (DiagnoseUseOfDecl(Fn, From->getBeginLoc()))
4240  return ExprError();
4241 
4242  From = FixOverloadedFunctionReference(From, Found, Fn);
4243 
4244  // We might get back another placeholder expression if we resolved to a
4245  // builtin.
4246  ExprResult Checked = CheckPlaceholderExpr(From);
4247  if (Checked.isInvalid())
4248  return ExprError();
4249 
4250  From = Checked.get();
4251  FromType = From->getType();
4252  }
4253 
4254  // If we're converting to an atomic type, first convert to the corresponding
4255  // non-atomic type.
4256  QualType ToAtomicType;
4257  if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
4258  ToAtomicType = ToType;
4259  ToType = ToAtomic->getValueType();
4260  }
4261 
4262  QualType InitialFromType = FromType;
4263  // Perform the first implicit conversion.
4264  switch (SCS.First) {
4265  case ICK_Identity:
4266  if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
4267  FromType = FromAtomic->getValueType().getUnqualifiedType();
4268  From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
4269  From, /*BasePath=*/nullptr, VK_PRValue,
4270  FPOptionsOverride());
4271  }
4272  break;
4273 
4274  case ICK_Lvalue_To_Rvalue: {
4275  assert(From->getObjectKind() != OK_ObjCProperty);
4276  ExprResult FromRes = DefaultLvalueConversion(From);
4277  if (FromRes.isInvalid())
4278  return ExprError();
4279 
4280  From = FromRes.get();
4281  FromType = From->getType();
4282  break;
4283  }
4284 
4285  case ICK_Array_To_Pointer:
4286  FromType = Context.getArrayDecayedType(FromType);
4287  From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, VK_PRValue,
4288  /*BasePath=*/nullptr, CCK)
4289  .get();
4290  break;
4291 
4293  FromType = Context.getPointerType(FromType);
4294  From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
4295  VK_PRValue, /*BasePath=*/nullptr, CCK)
4296  .get();
4297  break;
4298 
4299  default:
4300  llvm_unreachable("Improper first standard conversion");
4301  }
4302 
4303  // Perform the second implicit conversion
4304  switch (SCS.Second) {
4305  case ICK_Identity:
4306  // C++ [except.spec]p5:
4307  // [For] assignment to and initialization of pointers to functions,
4308  // pointers to member functions, and references to functions: the
4309  // target entity shall allow at least the exceptions allowed by the
4310  // source value in the assignment or initialization.
4311  switch (Action) {
4312  case AA_Assigning:
4313  case AA_Initializing:
4314  // Note, function argument passing and returning are initialization.
4315  case AA_Passing:
4316  case AA_Returning:
4317  case AA_Sending:
4318  case AA_Passing_CFAudited:
4319  if (CheckExceptionSpecCompatibility(From, ToType))
4320  return ExprError();
4321  break;
4322 
4323  case AA_Casting:
4324  case AA_Converting:
4325  // Casts and implicit conversions are not initialization, so are not
4326  // checked for exception specification mismatches.
4327  break;
4328  }
4329  // Nothing else to do.
4330  break;
4331 
4334  if (ToType->isBooleanType()) {
4335  assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
4336  SCS.Second == ICK_Integral_Promotion &&
4337  "only enums with fixed underlying type can promote to bool");
4338  From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, VK_PRValue,
4339  /*BasePath=*/nullptr, CCK)
4340  .get();
4341  } else {
4342  From = ImpCastExprToType(From, ToType, CK_IntegralCast, VK_PRValue,
4343  /*BasePath=*/nullptr, CCK)
4344  .get();
4345  }
4346  break;
4347 
4350  From = ImpCastExprToType(From, ToType, CK_FloatingCast, VK_PRValue,
4351  /*BasePath=*/nullptr, CCK)
4352  .get();
4353  break;
4354 
4355  case ICK_Complex_Promotion:
4356  case ICK_Complex_Conversion: {
4357  QualType FromEl = From->getType()->castAs<ComplexType>()->getElementType();
4358  QualType ToEl = ToType->castAs<ComplexType>()->getElementType();
4359  CastKind CK;
4360  if (FromEl->isRealFloatingType()) {
4361  if (ToEl->isRealFloatingType())
4362  CK = CK_FloatingComplexCast;
4363  else
4364  CK = CK_FloatingComplexToIntegralComplex;
4365  } else if (ToEl->isRealFloatingType()) {
4366  CK = CK_IntegralComplexToFloatingComplex;
4367  } else {
4368  CK = CK_IntegralComplexCast;
4369  }
4370  From = ImpCastExprToType(From, ToType, CK, VK_PRValue, /*BasePath=*/nullptr,
4371  CCK)
4372  .get();
4373  break;
4374  }
4375 
4376  case ICK_Floating_Integral:
4377  if (ToType->isRealFloatingType())
4378  From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, VK_PRValue,
4379  /*BasePath=*/nullptr, CCK)
4380  .get();
4381  else
4382  From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, VK_PRValue,
4383  /*BasePath=*/nullptr, CCK)
4384  .get();
4385  break;
4386 
4388  From = ImpCastExprToType(From, ToType, CK_NoOp, From->getValueKind(),
4389  /*BasePath=*/nullptr, CCK).get();
4390  break;
4391 
4393  case ICK_Pointer_Conversion: {
4394  if (SCS.IncompatibleObjC && Action != AA_Casting) {
4395  // Diagnose incompatible Objective-C conversions
4396  if (Action == AA_Initializing || Action == AA_Assigning)
4397  Diag(From->getBeginLoc(),
4398  diag::ext_typecheck_convert_incompatible_pointer)
4399  << ToType << From->getType() << Action << From->getSourceRange()
4400  << 0;
4401  else
4402  Diag(From->getBeginLoc(),
4403  diag::ext_typecheck_convert_incompatible_pointer)
4404  << From->getType() << ToType << Action << From->getSourceRange()
4405  << 0;
4406 
4407  if (From->getType()->isObjCObjectPointerType() &&
4408  ToType->isObjCObjectPointerType())
4410  } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() &&
4412  From->getType())) {
4413  if (Action == AA_Initializing)
4414  Diag(From->getBeginLoc(), diag::err_arc_weak_unavailable_assign);
4415  else
4416  Diag(From->getBeginLoc(), diag::err_arc_convesion_of_weak_unavailable)
4417  << (Action == AA_Casting) << From->getType() << ToType
4418  << From->getSourceRange();
4419  }
4420 
4421  // Defer address space conversion to the third conversion.
4422  QualType FromPteeType = From->getType()->getPointeeType();
4423  QualType ToPteeType = ToType->getPointeeType();
4424  QualType NewToType = ToType;
4425  if (!FromPteeType.isNull() && !ToPteeType.isNull() &&
4426  FromPteeType.getAddressSpace() != ToPteeType.getAddressSpace()) {
4427  NewToType = Context.removeAddrSpaceQualType(ToPteeType);
4428  NewToType = Context.getAddrSpaceQualType(NewToType,
4429  FromPteeType.getAddressSpace());
4430  if (ToType->isObjCObjectPointerType())
4431  NewToType = Context.getObjCObjectPointerType(NewToType);
4432  else if (ToType->isBlockPointerType())
4433  NewToType = Context.getBlockPointerType(NewToType);
4434  else
4435  NewToType = Context.getPointerType(NewToType);
4436  }
4437 
4438  CastKind Kind;
4439  CXXCastPath BasePath;
4440  if (CheckPointerConversion(From, NewToType, Kind, BasePath, CStyle))
4441  return ExprError();
4442 
4443  // Make sure we extend blocks if necessary.
4444  // FIXME: doing this here is really ugly.
4445  if (Kind == CK_BlockPointerToObjCPointerCast) {
4446  ExprResult E = From;
4448  From = E.get();
4449  }
4451  CheckObjCConversion(SourceRange(), NewToType, From, CCK);
4452  From = ImpCastExprToType(From, NewToType, Kind, VK_PRValue, &BasePath, CCK)
4453  .get();
4454  break;
4455  }
4456 
4457  case ICK_Pointer_Member: {
4458  CastKind Kind;
4459  CXXCastPath BasePath;
4460  if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
4461  return ExprError();
4462  if (CheckExceptionSpecCompatibility(From, ToType))
4463  return ExprError();
4464 
4465  // We may not have been able to figure out what this member pointer resolved
4466  // to up until this exact point. Attempt to lock-in it's inheritance model.
4468  (void)isCompleteType(From->getExprLoc(), From->getType());
4469  (void)isCompleteType(From->getExprLoc(), ToType);
4470  }
4471 
4472  From =
4473  ImpCastExprToType(From, ToType, Kind, VK_PRValue, &BasePath, CCK).get();
4474  break;
4475  }
4476 
4478  // Perform half-to-boolean conversion via float.
4479  if (From->getType()->isHalfType()) {
4480  From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
4481  FromType = Context.FloatTy;
4482  }
4483 
4484  From = ImpCastExprToType(From, Context.BoolTy,
4486  /*BasePath=*/nullptr, CCK)
4487  .get();
4488  break;
4489 
4490  case ICK_Derived_To_Base: {
4491  CXXCastPath BasePath;
4493  From->getType(), ToType.getNonReferenceType(), From->getBeginLoc(),
4494  From->getSourceRange(), &BasePath, CStyle))
4495  return ExprError();
4496 
4497  From = ImpCastExprToType(From, ToType.getNonReferenceType(),
4498  CK_DerivedToBase, From->getValueKind(),
4499  &BasePath, CCK).get();
4500  break;
4501  }
4502 
4503  case ICK_Vector_Conversion:
4504  From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
4505  /*BasePath=*/nullptr, CCK)
4506  .get();
4507  break;
4508 
4510  From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
4511  /*BasePath=*/nullptr, CCK)
4512  .get();
4513  break;
4514 
4515  case ICK_Vector_Splat: {
4516  // Vector splat from any arithmetic type to a vector.
4517  Expr *Elem = prepareVectorSplat(ToType, From).get();
4518  From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_PRValue,
4519  /*BasePath=*/nullptr, CCK)
4520  .get();
4521  break;
4522  }
4523 
4524  case ICK_Complex_Real:
4525  // Case 1. x -> _Complex y
4526  if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
4527  QualType ElType = ToComplex->getElementType();
4528  bool isFloatingComplex = ElType->isRealFloatingType();
4529 
4530  // x -> y
4531  if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
4532  // do nothing
4533  } else if (From->getType()->isRealFloatingType()) {
4534  From = ImpCastExprToType(From, ElType,
4535  isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
4536  } else {
4537  assert(From->getType()->isIntegerType());
4538  From = ImpCastExprToType(From, ElType,
4539  isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
4540  }
4541  // y -> _Complex y
4542  From = ImpCastExprToType(From, ToType,
4543  isFloatingComplex ? CK_FloatingRealToComplex
4544  : CK_IntegralRealToComplex).get();
4545 
4546  // Case 2. _Complex x -> y
4547  } else {
4548  auto *FromComplex = From->getType()->castAs<ComplexType>();
4549  QualType ElType = FromComplex->getElementType();
4550  bool isFloatingComplex = ElType->isRealFloatingType();
4551 
4552  // _Complex x -> x
4553  From = ImpCastExprToType(From, ElType,
4554  isFloatingComplex ? CK_FloatingComplexToReal
4555  : CK_IntegralComplexToReal,
4556  VK_PRValue, /*BasePath=*/nullptr, CCK)
4557  .get();
4558 
4559  // x -> y
4560  if (Context.hasSameUnqualifiedType(ElType, ToType)) {
4561  // do nothing
4562  } else if (ToType->isRealFloatingType()) {
4563  From = ImpCastExprToType(From, ToType,
4564  isFloatingComplex ? CK_FloatingCast
4565  : CK_IntegralToFloating,
4566  VK_PRValue, /*BasePath=*/nullptr, CCK)
4567  .get();
4568  } else {
4569  assert(ToType->isIntegerType());
4570  From = ImpCastExprToType(From, ToType,
4571  isFloatingComplex ? CK_FloatingToIntegral
4572  : CK_IntegralCast,
4573  VK_PRValue, /*BasePath=*/nullptr, CCK)
4574  .get();
4575  }
4576  }
4577  break;
4578 
4580  LangAS AddrSpaceL =
4581  ToType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
4582  LangAS AddrSpaceR =
4583  FromType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
4584  assert(Qualifiers::isAddressSpaceSupersetOf(AddrSpaceL, AddrSpaceR) &&
4585  "Invalid cast");
4586  CastKind Kind =
4587  AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast;
4588  From = ImpCastExprToType(From, ToType.getUnqualifiedType(), Kind,
4589  VK_PRValue, /*BasePath=*/nullptr, CCK)
4590  .get();
4591  break;
4592  }
4593 
4595  ExprResult FromRes = From;
4596  Sema::AssignConvertType ConvTy =
4598  if (FromRes.isInvalid())
4599  return ExprError();
4600  From = FromRes.get();
4601  assert ((ConvTy == Sema::Compatible) &&
4602  "Improper transparent union conversion");
4603  (void)ConvTy;
4604  break;
4605  }
4606 
4609  From = ImpCastExprToType(From, ToType,
4610  CK_ZeroToOCLOpaqueType,
4611  From->getValueKind()).get();
4612  break;
4613 
4614  case ICK_Lvalue_To_Rvalue:
4615  case ICK_Array_To_Pointer:
4618  case ICK_Qualification:
4620  case ICK_C_Only_Conversion:
4622  llvm_unreachable("Improper second standard conversion");
4623  }
4624 
4625  switch (SCS.Third) {
4626  case ICK_Identity:
4627  // Nothing to do.
4628  break;
4629 
4631  // If both sides are functions (or pointers/references to them), there could
4632  // be incompatible exception declarations.
4633  if (CheckExceptionSpecCompatibility(From, ToType))
4634  return ExprError();
4635 
4636  From = ImpCastExprToType(From, ToType, CK_NoOp, VK_PRValue,
4637  /*BasePath=*/nullptr, CCK)
4638  .get();
4639  break;
4640 
4641  case ICK_Qualification: {
4642  ExprValueKind VK = From->getValueKind();
4643  CastKind CK = CK_NoOp;
4644 
4645  if (ToType->isReferenceType() &&
4646  ToType->getPointeeType().getAddressSpace() !=
4647  From->getType().getAddressSpace())
4648  CK = CK_AddressSpaceConversion;
4649 
4650  if (ToType->isPointerType() &&
4651  ToType->getPointeeType().getAddressSpace() !=
4652  From->getType()->getPointeeType().getAddressSpace())
4653  CK = CK_AddressSpaceConversion;
4654 
4655  if (!isCast(CCK) &&
4656  !ToType->getPointeeType().getQualifiers().hasUnaligned() &&
4658  Diag(From->getBeginLoc(), diag::warn_imp_cast_drops_unaligned)
4659  << InitialFromType << ToType;
4660  }
4661 
4662  From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK, VK,
4663  /*BasePath=*/nullptr, CCK)
4664  .get();
4665 
4667  !getLangOpts().WritableStrings) {
4668  Diag(From->getBeginLoc(),
4670  ? diag::ext_deprecated_string_literal_conversion
4671  : diag::warn_deprecated_string_literal_conversion)
4672  << ToType.getNonReferenceType();
4673  }
4674 
4675  break;
4676  }
4677 
4678  default:
4679  llvm_unreachable("Improper third standard conversion");
4680  }
4681 
4682  // If this conversion sequence involved a scalar -> atomic conversion, perform
4683  // that conversion now.
4684  if (!ToAtomicType.isNull()) {
4685  assert(Context.hasSameType(
4686  ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()));
4687  From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic,
4688  VK_PRValue, nullptr, CCK)
4689  .get();
4690  }
4691 
4692  // Materialize a temporary if we're implicitly converting to a reference
4693  // type. This is not required by the C++ rules but is necessary to maintain
4694  // AST invariants.
4695  if (ToType->isReferenceType() && From->isPRValue()) {
4697  if (Res.isInvalid())
4698  return ExprError();
4699  From = Res.get();
4700  }
4701 
4702  // If this conversion sequence succeeded and involved implicitly converting a
4703  // _Nullable type to a _Nonnull one, complain.
4704  if (!isCast(CCK))
4705  diagnoseNullableToNonnullConversion(ToType, InitialFromType,
4706  From->getBeginLoc());
4707 
4708  return From;
4709 }
4710 
4711 /// Check the completeness of a type in a unary type trait.
4712 ///
4713 /// If the particular type trait requires a complete type, tries to complete
4714 /// it. If completing the type fails, a diagnostic is emitted and false
4715 /// returned. If completing the type succeeds or no completion was required,
4716 /// returns true.
4718  SourceLocation Loc,
4719  QualType ArgTy) {
4720  // C++0x [meta.unary.prop]p3:
4721  // For all of the class templates X declared in this Clause, instantiating
4722  // that template with a template argument that is a class template
4723  // specialization may result in the implicit instantiation of the template
4724  // argument if and only if the semantics of X require that the argument
4725  // must be a complete type.
4726  // We apply this rule to all the type trait expressions used to implement
4727  // these class templates. We also try to follow any GCC documented behavior
4728  // in these expressions to ensure portability of standard libraries.
4729  switch (UTT) {
4730  default: llvm_unreachable("not a UTT");
4731  // is_complete_type somewhat obviously cannot require a complete type.
4732  case UTT_IsCompleteType:
4733  // Fall-through
4734 
4735  // These traits are modeled on the type predicates in C++0x
4736  // [meta.unary.cat] and [meta.unary.comp]. They are not specified as
4737  // requiring a complete type, as whether or not they return true cannot be
4738  // impacted by the completeness of the type.
4739  case UTT_IsVoid:
4740  case UTT_IsIntegral:
4741  case UTT_IsFloatingPoint:
4742  case UTT_IsArray:
4743  case UTT_IsPointer:
4744  case UTT_IsLvalueReference:
4745  case UTT_IsRvalueReference:
4746  case UTT_IsMemberFunctionPointer:
4747  case UTT_IsMemberObjectPointer:
4748  case UTT_IsEnum:
4749  case UTT_IsUnion:
4750  case UTT_IsClass:
4751  case UTT_IsFunction:
4752  case UTT_IsReference:
4753  case UTT_IsArithmetic:
4754  case UTT_IsFundamental:
4755  case UTT_IsObject:
4756  case UTT_IsScalar:
4757  case UTT_IsCompound:
4758  case UTT_IsMemberPointer:
4759  // Fall-through
4760 
4761  // These traits are modeled on type predicates in C++0x [meta.unary.prop]
4762  // which requires some of its traits to have the complete type. However,
4763  // the completeness of the type cannot impact these traits' semantics, and
4764  // so they don't require it. This matches the comments on these traits in
4765  // Table 49.
4766  case UTT_IsConst:
4767  case UTT_IsVolatile:
4768  case UTT_IsSigned:
4769  case UTT_IsUnsigned:
4770 
4771  // This type trait always returns false, checking the type is moot.
4772  case UTT_IsInterfaceClass:
4773  return true;
4774 
4775  // C++14 [meta.unary.prop]:
4776  // If T is a non-union class type, T shall be a complete type.
4777  case UTT_IsEmpty:
4778  case UTT_IsPolymorphic:
4779  case UTT_IsAbstract:
4780  if (const auto *RD = ArgTy->getAsCXXRecordDecl())
4781  if (!RD->isUnion())
4782  return !S.RequireCompleteType(
4783  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4784  return true;
4785 
4786  // C++14 [meta.unary.prop]:
4787  // If T is a class type, T shall be a complete type.
4788  case UTT_IsFinal:
4789  case UTT_IsSealed:
4790  if (ArgTy->getAsCXXRecordDecl())
4791  return !S.RequireCompleteType(
4792  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4793  return true;
4794 
4795  // C++1z [meta.unary.prop]:
4796  // remove_all_extents_t<T> shall be a complete type or cv void.
4797  case UTT_IsAggregate:
4798  case UTT_IsTrivial:
4799  case UTT_IsTriviallyCopyable:
4800  case UTT_IsStandardLayout:
4801  case UTT_IsPOD:
4802  case UTT_IsLiteral:
4803  // By analogy, is_trivially_relocatable imposes the same constraints.
4804  case UTT_IsTriviallyRelocatable:
4805  // Per the GCC type traits documentation, T shall be a complete type, cv void,
4806  // or an array of unknown bound. But GCC actually imposes the same constraints
4807  // as above.
4808  case UTT_HasNothrowAssign:
4809  case UTT_HasNothrowMoveAssign:
4810  case UTT_HasNothrowConstructor:
4811  case UTT_HasNothrowCopy:
4812  case UTT_HasTrivialAssign:
4813  case UTT_HasTrivialMoveAssign:
4814  case UTT_HasTrivialDefaultConstructor:
4815  case UTT_HasTrivialMoveConstructor:
4816  case UTT_HasTrivialCopy:
4817  case UTT_HasTrivialDestructor:
4818  case UTT_HasVirtualDestructor:
4819  ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0);
4820  LLVM_FALLTHROUGH;
4821 
4822  // C++1z [meta.unary.prop]:
4823  // T shall be a complete type, cv void, or an array of unknown bound.
4824  case UTT_IsDestructible:
4825  case UTT_IsNothrowDestructible:
4826  case UTT_IsTriviallyDestructible:
4827  case UTT_HasUniqueObjectRepresentations:
4828  if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType())
4829  return true;
4830 
4831  return !S.RequireCompleteType(
4832  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4833  }
4834 }
4835 
4837  Sema &Self, SourceLocation KeyLoc, ASTContext &C,
4838  bool (CXXRecordDecl::*HasTrivial)() const,
4839  bool (CXXRecordDecl::*HasNonTrivial)() const,
4840  bool (CXXMethodDecl::*IsDesiredOp)() const)
4841 {
4842  CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
4843  if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)())
4844  return true;
4845 
4846  DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op);
4847  DeclarationNameInfo NameInfo(Name, KeyLoc);
4848  LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName);
4849  if (Self.LookupQualifiedName(Res, RD)) {
4850  bool FoundOperator = false;
4851  Res.suppressDiagnostics();
4852  for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end();
4853  Op != OpEnd; ++Op) {
4854  if (isa<FunctionTemplateDecl>(*Op))
4855  continue;
4856 
4857  CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op);
4858  if((Operator->*IsDesiredOp)()) {
4859  FoundOperator = true;
4860  auto *CPT = Operator->getType()->castAs<FunctionProtoType>();
4861  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
4862  if (!CPT || !CPT->isNothrow())
4863  return false;
4864  }
4865  }
4866  return FoundOperator;
4867  }
4868  return false;
4869 }
4870 
4871 static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
4872  SourceLocation KeyLoc, QualType T) {
4873  assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
4874 
4875  ASTContext &C = Self.Context;
4876  switch(UTT) {
4877  default: llvm_unreachable("not a UTT");
4878  // Type trait expressions corresponding to the primary type category
4879  // predicates in C++0x [meta.unary.cat].
4880  case UTT_IsVoid:
4881  return T->isVoidType();
4882  case UTT_IsIntegral:
4883  return T->isIntegralType(C);
4884  case UTT_IsFloatingPoint:
4885  return T->isFloatingType();
4886  case UTT_IsArray:
4887  return T->isArrayType();
4888  case UTT_IsPointer:
4889  return T->isAnyPointerType();
4890  case UTT_IsLvalueReference:
4891  return T->isLValueReferenceType();
4892  case UTT_IsRvalueReference:
4893  return T->isRValueReferenceType();
4894  case UTT_IsMemberFunctionPointer:
4895  return T->isMemberFunctionPointerType();
4896  case UTT_IsMemberObjectPointer:
4897  return T->isMemberDataPointerType();
4898  case UTT_IsEnum:
4899  return T->isEnumeralType();
4900  case UTT_IsUnion:
4901  return T->isUnionType();
4902  case UTT_IsClass:
4903  return T->isClassType() || T->isStructureType() || T->isInterfaceType();
4904  case UTT_IsFunction:
4905  return T->isFunctionType();
4906 
4907  // Type trait expressions which correspond to the convenient composition
4908  // predicates in C++0x [meta.unary.comp].
4909  case UTT_IsReference:
4910  return T->isReferenceType();
4911  case UTT_IsArithmetic:
4912  return T->isArithmeticType() && !T->isEnumeralType();
4913  case UTT_IsFundamental:
4914  return T->isFundamentalType();
4915  case UTT_IsObject:
4916  return T->isObjectType();
4917  case UTT_IsScalar:
4918  // Note: semantic analysis depends on Objective-C lifetime types to be
4919  // considered scalar types. However, such types do not actually behave
4920  // like scalar types at run time (since they may require retain/release
4921  // operations), so we report them as non-scalar.
4922  if (T->isObjCLifetimeType()) {
4923  switch (T.getObjCLifetime()) {
4924  case Qualifiers::OCL_None:
4926  return true;
4927 
4929  case Qualifiers::OCL_Weak:
4931  return false;
4932  }
4933  }
4934 
4935  return T->isScalarType();
4936  case UTT_IsCompound:
4937  return T->isCompoundType();
4938  case UTT_IsMemberPointer:
4939  return T->isMemberPointerType();
4940 
4941  // Type trait expressions which correspond to the type property predicates
4942  // in C++0x [meta.unary.prop].
4943  case UTT_IsConst:
4944  return T.isConstQualified();
4945  case UTT_IsVolatile:
4946  return T.isVolatileQualified();
4947  case UTT_IsTrivial:
4948  return T.isTrivialType(C);
4949  case UTT_IsTriviallyCopyable:
4950  return T.isTriviallyCopyableType(C);
4951  case UTT_IsStandardLayout:
4952  return T->isStandardLayoutType();
4953  case UTT_IsPOD:
4954  return T.isPODType(C);
4955  case UTT_IsLiteral:
4956  return T->isLiteralType(C);
4957  case UTT_IsEmpty:
4958  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4959  return !RD->isUnion() && RD->isEmpty();
4960  return false;
4961  case UTT_IsPolymorphic:
4962  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4963  return !RD->isUnion() && RD->isPolymorphic();
4964  return false;
4965  case UTT_IsAbstract:
4966  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4967  return !RD->isUnion() && RD->isAbstract();
4968  return false;
4969  case UTT_IsAggregate:
4970  // Report vector extensions and complex types as aggregates because they
4971  // support aggregate initialization. GCC mirrors this behavior for vectors
4972  // but not _Complex.
4973  return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() ||
4974  T->isAnyComplexType();
4975  // __is_interface_class only returns true when CL is invoked in /CLR mode and
4976  // even then only when it is used with the 'interface struct ...' syntax
4977  // Clang doesn't support /CLR which makes this type trait moot.
4978  case UTT_IsInterfaceClass:
4979  return false;
4980  case UTT_IsFinal:
4981  case UTT_IsSealed:
4982  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4983  return RD->hasAttr<FinalAttr>();
4984  return false;
4985  case UTT_IsSigned:
4986  // Enum types should always return false.
4987  // Floating points should always return true.
4988  return T->isFloatingType() ||
4989  (T->isSignedIntegerType() && !T->isEnumeralType());
4990  case UTT_IsUnsigned:
4991  // Enum types should always return false.
4992  return T->isUnsignedIntegerType() && !T->isEnumeralType();
4993 
4994  // Type trait expressions which query classes regarding their construction,
4995  // destruction, and copying. Rather than being based directly on the
4996  // related type predicates in the standard, they are specified by both
4997  // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those
4998  // specifications.
4999  //
5000  // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html
5001  // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
5002  //
5003  // Note that these builtins do not behave as documented in g++: if a class
5004  // has both a trivial and a non-trivial special member of a particular kind,
5005  // they return false! For now, we emulate this behavior.
5006  // FIXME: This appears to be a g++ bug: more complex cases reveal that it
5007  // does not correctly compute triviality in the presence of multiple special
5008  // members of the same kind. Revisit this once the g++ bug is fixed.
5009  case UTT_HasTrivialDefaultConstructor:
5010  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5011  // If __is_pod (type) is true then the trait is true, else if type is
5012  // a cv class or union type (or array thereof) with a trivial default
5013  // constructor ([class.ctor]) then the trait is true, else it is false.
5014  if (T.isPODType(C))
5015  return true;
5016  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5017  return RD->hasTrivialDefaultConstructor() &&
5019  return false;
5020  case UTT_HasTrivialMoveConstructor:
5021  // This trait is implemented by MSVC 2012 and needed to parse the
5022  // standard library headers. Specifically this is used as the logic
5023  // behind std::is_trivially_move_constructible (20.9.4.3).
5024  if (T.isPODType(C))
5025  return true;
5026  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5028  return false;
5029  case UTT_HasTrivialCopy:
5030  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5031  // If __is_pod (type) is true or type is a reference type then
5032  // the trait is true, else if type is a cv class or union type
5033  // with a trivial copy constructor ([class.copy]) then the trait
5034  // is true, else it is false.
5035  if (T.isPODType(C) || T->isReferenceType())
5036  return true;
5037  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5038  return RD->hasTrivialCopyConstructor() &&
5040  return false;
5041  case UTT_HasTrivialMoveAssign:
5042  // This trait is implemented by MSVC 2012 and needed to parse the
5043  // standard library headers. Specifically it is used as the logic
5044  // behind std::is_trivially_move_assignable (20.9.4.3)
5045  if (T.isPODType(C))
5046  return true;
5047  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5049  return false;
5050  case UTT_HasTrivialAssign:
5051  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5052  // If type is const qualified or is a reference type then the
5053  // trait is false. Otherwise if __is_pod (type) is true then the
5054  // trait is true, else if type is a cv class or union type with
5055  // a trivial copy assignment ([class.copy]) then the trait is
5056  // true, else it is false.
5057  // Note: the const and reference restrictions are interesting,
5058  // given that const and reference members don't prevent a class
5059  // from having a trivial copy assignment operator (but do cause
5060  // errors if the copy assignment operator is actually used, q.v.
5061  // [class.copy]p12).
5062 
5063  if (T.isConstQualified())
5064  return false;
5065  if (T.isPODType(C))
5066  return true;
5067  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5068  return RD->hasTrivialCopyAssignment() &&
5070  return false;
5071  case UTT_IsDestructible:
5072  case UTT_IsTriviallyDestructible:
5073  case UTT_IsNothrowDestructible:
5074  // C++14 [meta.unary.prop]:
5075  // For reference types, is_destructible<T>::value is true.
5076  if (T->isReferenceType())
5077  return true;
5078 
5079  // Objective-C++ ARC: autorelease types don't require destruction.
5080  if (T->isObjCLifetimeType() &&
5082  return true;
5083 
5084  // C++14 [meta.unary.prop]:
5085  // For incomplete types and function types, is_destructible<T>::value is
5086  // false.
5087  if (T->isIncompleteType() || T->isFunctionType())
5088  return false;
5089 
5090  // A type that requires destruction (via a non-trivial destructor or ARC
5091  // lifetime semantics) is not trivially-destructible.
5092  if (UTT == UTT_IsTriviallyDestructible && T.isDestructedType())
5093  return false;
5094 
5095  // C++14 [meta.unary.prop]:
5096  // For object types and given U equal to remove_all_extents_t<T>, if the
5097  // expression std::declval<U&>().~U() is well-formed when treated as an
5098  // unevaluated operand (Clause 5), then is_destructible<T>::value is true
5099  if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
5100  CXXDestructorDecl *Destructor = Self.LookupDestructor(RD);
5101  if (!Destructor)
5102  return false;
5103  // C++14 [dcl.fct.def.delete]p2:
5104  // A program that refers to a deleted function implicitly or
5105  // explicitly, other than to declare it, is ill-formed.
5106  if (Destructor->isDeleted())
5107  return false;
5108  if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public)
5109  return false;
5110  if (UTT == UTT_IsNothrowDestructible) {
5111  auto *CPT = Destructor->getType()->castAs<FunctionProtoType>();
5112  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5113  if (!CPT || !CPT->isNothrow())
5114  return false;
5115  }
5116  }
5117  return true;
5118 
5119  case UTT_HasTrivialDestructor:
5120  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
5121  // If __is_pod (type) is true or type is a reference type
5122  // then the trait is true, else if type is a cv class or union
5123  // type (or array thereof) with a trivial destructor
5124  // ([class.dtor]) then the trait is true, else it is
5125  // false.
5126  if (T.isPODType(C) || T->isReferenceType())
5127  return true;
5128 
5129  // Objective-C++ ARC: autorelease types don't require destruction.
5130  if (T->isObjCLifetimeType() &&
5132  return true;
5133 
5134  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5135  return RD->hasTrivialDestructor();
5136  return false;
5137  // TODO: Propagate nothrowness for implicitly declared special members.
5138  case UTT_HasNothrowAssign:
5139  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5140  // If type is const qualified or is a reference type then the
5141  // trait is false. Otherwise if __has_trivial_assign (type)
5142  // is true then the trait is true, else if type is a cv class
5143  // or union type with copy assignment operators that are known
5144  // not to throw an exception then the trait is true, else it is
5145  // false.
5146  if (C.getBaseElementType(T).isConstQualified())
5147  return false;
5148  if (T->isReferenceType())
5149  return false;
5150  if (T.isPODType(C) || T->isObjCLifetimeType())
5151  return true;
5152 
5153  if (const RecordType *RT = T->getAs<RecordType>())
5154  return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
5158  return false;
5159  case UTT_HasNothrowMoveAssign:
5160  // This trait is implemented by MSVC 2012 and needed to parse the
5161  // standard library headers. Specifically this is used as the logic
5162  // behind std::is_nothrow_move_assignable (20.9.4.3).
5163  if (T.isPODType(C))
5164  return true;
5165 
5166  if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>())
5167  return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
5171  return false;
5172  case UTT_HasNothrowCopy:
5173  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5174  // If __has_trivial_copy (type) is true then the trait is true, else
5175  // if type is a cv class or union type with copy constructors that are
5176  // known not to throw an exception then the trait is true, else it is
5177  // false.
5178  if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType())
5179  return true;
5180  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
5181  if (RD->hasTrivialCopyConstructor() &&
5183  return true;
5184 
5185  bool FoundConstructor = false;
5186  unsigned FoundTQs;
5187  for (const auto *ND : Self.LookupConstructors(RD)) {
5188  // A template constructor is never a copy constructor.
5189  // FIXME: However, it may actually be selected at the actual overload
5190  // resolution point.
5191  if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
5192  continue;
5193  // UsingDecl itself is not a constructor
5194  if (isa<UsingDecl>(ND))
5195  continue;
5196  auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
5197  if (Constructor->isCopyConstructor(FoundTQs)) {
5198  FoundConstructor = true;
5199  auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
5200  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5201  if (!CPT)
5202  return false;
5203  // TODO: check whether evaluating default arguments can throw.
5204  // For now, we'll be conservative and assume that they can throw.
5205  if (!CPT->isNothrow() || CPT->getNumParams() > 1)
5206  return false;
5207  }
5208  }
5209 
5210  return FoundConstructor;
5211  }
5212  return false;
5213  case UTT_HasNothrowConstructor:
5214  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
5215  // If __has_trivial_constructor (type) is true then the trait is
5216  // true, else if type is a cv class or union type (or array
5217  // thereof) with a default constructor that is known not to
5218  // throw an exception then the trait is true, else it is false.
5219  if (T.isPODType(C) || T->isObjCLifetimeType())
5220  return true;
5221  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
5222  if (RD->hasTrivialDefaultConstructor() &&
5224  return true;
5225 
5226  bool FoundConstructor = false;
5227  for (const auto *ND : Self.LookupConstructors(RD)) {
5228  // FIXME: In C++0x, a constructor template can be a default constructor.
5229  if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
5230  continue;
5231  // UsingDecl itself is not a constructor
5232  if (isa<UsingDecl>(ND))
5233  continue;
5234  auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
5235  if (Constructor->isDefaultConstructor()) {
5236  FoundConstructor = true;
5237  auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
5238  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5239  if (!CPT)
5240  return false;
5241  // FIXME: check whether evaluating default arguments can throw.
5242  // For now, we'll be conservative and assume that they can throw.
5243  if (!CPT->isNothrow() || CPT->getNumParams() > 0)
5244  return false;
5245  }
5246  }
5247  return FoundConstructor;
5248  }
5249  return false;
5250  case UTT_HasVirtualDestructor:
5251  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5252  // If type is a class type with a virtual destructor ([class.dtor])
5253  // then the trait is true, else it is false.
5254  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5255  if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD))
5256  return Destructor->isVirtual();
5257  return false;
5258 
5259  // These type trait expressions are modeled on the specifications for the
5260  // Embarcadero C++0x type trait functions:
5261  // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
5262  case UTT_IsCompleteType:
5263  // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_):
5264  // Returns True if and only if T is a complete type at the point of the
5265  // function call.
5266  return !T->isIncompleteType();
5267  case UTT_HasUniqueObjectRepresentations:
5268  return C.hasUniqueObjectRepresentations(T);
5269  case UTT_IsTriviallyRelocatable:
5270  return T.isTriviallyRelocatableType(C);
5271  }
5272 }
5273 
5274 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
5275  QualType RhsT, SourceLocation KeyLoc);
5276 
5279  SourceLocation RParenLoc) {
5280  if (Kind <= UTT_Last)
5281  return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType());
5282 
5283  // Evaluate BTT_ReferenceBindsToTemporary alongside the IsConstructible
5284  // traits to avoid duplication.
5285  if (Kind <= BTT_Last && Kind != BTT_ReferenceBindsToTemporary)
5286  return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(),
5287  Args[1]->getType(), RParenLoc);
5288 
5289  switch (Kind) {
5290  case clang::BTT_ReferenceBindsToTemporary:
5291  case clang::TT_IsConstructible:
5292  case clang::TT_IsNothrowConstructible:
5293  case clang::TT_IsTriviallyConstructible: {
5294  // C++11 [meta.unary.prop]:
5295  // is_trivially_constructible is defined as:
5296  //
5297  // is_constructible<T, Args...>::value is true and the variable
5298  // definition for is_constructible, as defined below, is known to call
5299  // no operation that is not trivial.
5300  //
5301  // The predicate condition for a template specialization
5302  // is_constructible<T, Args...> shall be satisfied if and only if the
5303  // following variable definition would be well-formed for some invented
5304  // variable t:
5305  //
5306  // T t(create<Args>()...);
5307  assert(!Args.empty());
5308 
5309  // Precondition: T and all types in the parameter pack Args shall be
5310  // complete types, (possibly cv-qualified) void, or arrays of
5311  // unknown bound.
5312  for (const auto *TSI : Args) {
5313  QualType ArgTy = TSI->getType();
5314  if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType())
5315  continue;
5316 
5317  if (S.RequireCompleteType(KWLoc, ArgTy,
5318  diag::err_incomplete_type_used_in_type_trait_expr))
5319  return false;
5320  }
5321 
5322  // Make sure the first argument is not incomplete nor a function type.
5323  QualType T = Args[0]->getType();
5324  if (T->isIncompleteType() || T->isFunctionType())
5325  return false;
5326 
5327  // Make sure the first argument is not an abstract type.
5328  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
5329  if (RD && RD->isAbstract())
5330  return false;
5331 
5332  llvm::BumpPtrAllocator OpaqueExprAllocator;
5333  SmallVector<Expr *, 2> ArgExprs;
5334  ArgExprs.reserve(Args.size() - 1);
5335  for (unsigned I = 1, N = Args.size(); I != N; ++I) {
5336  QualType ArgTy = Args[I]->getType();
5337  if (ArgTy->isObjectType() || ArgTy->isFunctionType())
5338  ArgTy = S.Context.getRValueReferenceType(ArgTy);
5339  ArgExprs.push_back(
5340  new (OpaqueExprAllocator.Allocate<OpaqueValueExpr>())
5341  OpaqueValueExpr(Args[I]->getTypeLoc().getBeginLoc(),
5342  ArgTy.getNonLValueExprType(S.Context),
5343  Expr::getValueKindForType(ArgTy)));
5344  }
5345 
5346  // Perform the initialization in an unevaluated context within a SFINAE
5347  // trap at translation unit scope.
5350  Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
5352  InitializedEntity To(
5355  RParenLoc));
5356  InitializationSequence Init(S, To, InitKind, ArgExprs);
5357  if (Init.Failed())
5358  return false;
5359 
5360  ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs);
5361  if (Result.isInvalid() || SFINAE.hasErrorOccurred())
5362  return false;
5363 
5364  if (Kind == clang::TT_IsConstructible)
5365  return true;