clang  16.0.0git
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(Context.getElaboratedType(ETK_None, nullptr, 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  // FIXME: Many of the scope checks here seem incorrect.
847  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  TemplateDeductionInfo Info(Deduce->getExprLoc());
1510  TemplateDeductionResult Result =
1511  DeduceAutoType(TInfo->getTypeLoc(), Deduce, DeducedType, Info);
1512  if (Result != TDK_Success && Result != TDK_AlreadyDiagnosed)
1513  return ExprError(Diag(TyBeginLoc, diag::err_auto_expr_deduction_failure)
1514  << Ty << Deduce->getType() << FullRange
1515  << Deduce->getSourceRange());
1516  if (DeducedType.isNull()) {
1517  assert(Result == TDK_AlreadyDiagnosed);
1518  return ExprError();
1519  }
1520 
1521  Ty = DeducedType;
1522  Entity = InitializedEntity::InitializeTemporary(TInfo, Ty);
1523  }
1524 
1526  // FIXME: CXXUnresolvedConstructExpr does not model list-initialization
1527  // directly. We work around this by dropping the locations of the braces.
1528  SourceRange Locs = ListInitialization
1529  ? SourceRange()
1530  : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
1532  TInfo, Locs.getBegin(), Exprs,
1533  Locs.getEnd());
1534  }
1535 
1536  // C++ [expr.type.conv]p1:
1537  // If the expression list is a parenthesized single expression, the type
1538  // conversion expression is equivalent (in definedness, and if defined in
1539  // meaning) to the corresponding cast expression.
1540  if (Exprs.size() == 1 && !ListInitialization &&
1541  !isa<InitListExpr>(Exprs[0])) {
1542  Expr *Arg = Exprs[0];
1543  return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenOrBraceLoc, Arg,
1544  RParenOrBraceLoc);
1545  }
1546 
1547  // For an expression of the form T(), T shall not be an array type.
1548  QualType ElemTy = Ty;
1549  if (Ty->isArrayType()) {
1550  if (!ListInitialization)
1551  return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type)
1552  << FullRange);
1553  ElemTy = Context.getBaseElementType(Ty);
1554  }
1555 
1556  // Only construct objects with object types.
1557  // The standard doesn't explicitly forbid function types here, but that's an
1558  // obvious oversight, as there's no way to dynamically construct a function
1559  // in general.
1560  if (Ty->isFunctionType())
1561  return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type)
1562  << Ty << FullRange);
1563 
1564  // C++17 [expr.type.conv]p2:
1565  // If the type is cv void and the initializer is (), the expression is a
1566  // prvalue of the specified type that performs no initialization.
1567  if (!Ty->isVoidType() &&
1568  RequireCompleteType(TyBeginLoc, ElemTy,
1569  diag::err_invalid_incomplete_type_use, FullRange))
1570  return ExprError();
1571 
1572  // Otherwise, the expression is a prvalue of the specified type whose
1573  // result object is direct-initialized (11.6) with the initializer.
1574  InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
1575  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);
1576 
1577  if (Result.isInvalid())
1578  return Result;
1579 
1580  Expr *Inner = Result.get();
1581  if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
1582  Inner = BTE->getSubExpr();
1583  if (!isa<CXXTemporaryObjectExpr>(Inner) &&
1584  !isa<CXXScalarValueInitExpr>(Inner)) {
1585  // If we created a CXXTemporaryObjectExpr, that node also represents the
1586  // functional cast. Otherwise, create an explicit cast to represent
1587  // the syntactic form of a functional-style cast that was used here.
1588  //
1589  // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr
1590  // would give a more consistent AST representation than using a
1591  // CXXTemporaryObjectExpr. It's also weird that the functional cast
1592  // is sometimes handled by initialization and sometimes not.
1593  QualType ResultType = Result.get()->getType();
1594  SourceRange Locs = ListInitialization
1595  ? SourceRange()
1596  : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc);
1598  Context, ResultType, Expr::getValueKindForType(Ty), TInfo, CK_NoOp,
1599  Result.get(), /*Path=*/nullptr, CurFPFeatureOverrides(),
1600  Locs.getBegin(), Locs.getEnd());
1601  }
1602 
1603  return Result;
1604 }
1605 
1607  // [CUDA] Ignore this function, if we can't call it.
1608  const FunctionDecl *Caller = getCurFunctionDecl(/*AllowLambda=*/true);
1609  if (getLangOpts().CUDA) {
1610  auto CallPreference = IdentifyCUDAPreference(Caller, Method);
1611  // If it's not callable at all, it's not the right function.
1612  if (CallPreference < CFP_WrongSide)
1613  return false;
1614  if (CallPreference == CFP_WrongSide) {
1615  // Maybe. We have to check if there are better alternatives.
1617  Method->getDeclContext()->lookup(Method->getDeclName());
1618  for (const auto *D : R) {
1619  if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
1620  if (IdentifyCUDAPreference(Caller, FD) > CFP_WrongSide)
1621  return false;
1622  }
1623  }
1624  // We've found no better variants.
1625  }
1626  }
1627 
1629  bool Result = Method->isUsualDeallocationFunction(PreventedBy);
1630 
1631  if (Result || !getLangOpts().CUDA || PreventedBy.empty())
1632  return Result;
1633 
1634  // In case of CUDA, return true if none of the 1-argument deallocator
1635  // functions are actually callable.
1636  return llvm::none_of(PreventedBy, [&](const FunctionDecl *FD) {
1637  assert(FD->getNumParams() == 1 &&
1638  "Only single-operand functions should be in PreventedBy");
1639  return IdentifyCUDAPreference(Caller, FD) >= CFP_HostDevice;
1640  });
1641 }
1642 
1643 /// Determine whether the given function is a non-placement
1644 /// deallocation function.
1646  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
1647  return S.isUsualDeallocationFunction(Method);
1648 
1649  if (FD->getOverloadedOperator() != OO_Delete &&
1650  FD->getOverloadedOperator() != OO_Array_Delete)
1651  return false;
1652 
1653  unsigned UsualParams = 1;
1654 
1655  if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() &&
1657  FD->getParamDecl(UsualParams)->getType(),
1658  S.Context.getSizeType()))
1659  ++UsualParams;
1660 
1661  if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() &&
1663  FD->getParamDecl(UsualParams)->getType(),
1665  ++UsualParams;
1666 
1667  return UsualParams == FD->getNumParams();
1668 }
1669 
1670 namespace {
1671  struct UsualDeallocFnInfo {
1672  UsualDeallocFnInfo() : Found(), FD(nullptr) {}
1673  UsualDeallocFnInfo(Sema &S, DeclAccessPair Found)
1674  : Found(Found), FD(dyn_cast<FunctionDecl>(Found->getUnderlyingDecl())),
1675  Destroying(false), HasSizeT(false), HasAlignValT(false),
1676  CUDAPref(Sema::CFP_Native) {
1677  // A function template declaration is never a usual deallocation function.
1678  if (!FD)
1679  return;
1680  unsigned NumBaseParams = 1;
1681  if (FD->isDestroyingOperatorDelete()) {
1682  Destroying = true;
1683  ++NumBaseParams;
1684  }
1685 
1686  if (NumBaseParams < FD->getNumParams() &&
1688  FD->getParamDecl(NumBaseParams)->getType(),
1689  S.Context.getSizeType())) {
1690  ++NumBaseParams;
1691  HasSizeT = true;
1692  }
1693 
1694  if (NumBaseParams < FD->getNumParams() &&
1695  FD->getParamDecl(NumBaseParams)->getType()->isAlignValT()) {
1696  ++NumBaseParams;
1697  HasAlignValT = true;
1698  }
1699 
1700  // In CUDA, determine how much we'd like / dislike to call this.
1701  if (S.getLangOpts().CUDA)
1702  if (auto *Caller = S.getCurFunctionDecl(/*AllowLambda=*/true))
1703  CUDAPref = S.IdentifyCUDAPreference(Caller, FD);
1704  }
1705 
1706  explicit operator bool() const { return FD; }
1707 
1708  bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize,
1709  bool WantAlign) const {
1710  // C++ P0722:
1711  // A destroying operator delete is preferred over a non-destroying
1712  // operator delete.
1713  if (Destroying != Other.Destroying)
1714  return Destroying;
1715 
1716  // C++17 [expr.delete]p10:
1717  // If the type has new-extended alignment, a function with a parameter
1718  // of type std::align_val_t is preferred; otherwise a function without
1719  // such a parameter is preferred
1720  if (HasAlignValT != Other.HasAlignValT)
1721  return HasAlignValT == WantAlign;
1722 
1723  if (HasSizeT != Other.HasSizeT)
1724  return HasSizeT == WantSize;
1725 
1726  // Use CUDA call preference as a tiebreaker.
1727  return CUDAPref > Other.CUDAPref;
1728  }
1729 
1730  DeclAccessPair Found;
1731  FunctionDecl *FD;
1732  bool Destroying, HasSizeT, HasAlignValT;
1734  };
1735 }
1736 
1737 /// Determine whether a type has new-extended alignment. This may be called when
1738 /// the type is incomplete (for a delete-expression with an incomplete pointee
1739 /// type), in which case it will conservatively return false if the alignment is
1740 /// not known.
1741 static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) {
1742  return S.getLangOpts().AlignedAllocation &&
1743  S.getASTContext().getTypeAlignIfKnown(AllocType) >
1745 }
1746 
1747 /// Select the correct "usual" deallocation function to use from a selection of
1748 /// deallocation functions (either global or class-scope).
1749 static UsualDeallocFnInfo resolveDeallocationOverload(
1750  Sema &S, LookupResult &R, bool WantSize, bool WantAlign,
1751  llvm::SmallVectorImpl<UsualDeallocFnInfo> *BestFns = nullptr) {
1752  UsualDeallocFnInfo Best;
1753 
1754  for (auto I = R.begin(), E = R.end(); I != E; ++I) {
1755  UsualDeallocFnInfo Info(S, I.getPair());
1756  if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) ||
1757  Info.CUDAPref == Sema::CFP_Never)
1758  continue;
1759 
1760  if (!Best) {
1761  Best = Info;
1762  if (BestFns)
1763  BestFns->push_back(Info);
1764  continue;
1765  }
1766 
1767  if (Best.isBetterThan(Info, WantSize, WantAlign))
1768  continue;
1769 
1770  // If more than one preferred function is found, all non-preferred
1771  // functions are eliminated from further consideration.
1772  if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign))
1773  BestFns->clear();
1774 
1775  Best = Info;
1776  if (BestFns)
1777  BestFns->push_back(Info);
1778  }
1779 
1780  return Best;
1781 }
1782 
1783 /// Determine whether a given type is a class for which 'delete[]' would call
1784 /// a member 'operator delete[]' with a 'size_t' parameter. This implies that
1785 /// we need to store the array size (even if the type is
1786 /// trivially-destructible).
1788  QualType allocType) {
1789  const RecordType *record =
1790  allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
1791  if (!record) return false;
1792 
1793  // Try to find an operator delete[] in class scope.
1794 
1795  DeclarationName deleteName =
1796  S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
1797  LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
1798  S.LookupQualifiedName(ops, record->getDecl());
1799 
1800  // We're just doing this for information.
1801  ops.suppressDiagnostics();
1802 
1803  // Very likely: there's no operator delete[].
1804  if (ops.empty()) return false;
1805 
1806  // If it's ambiguous, it should be illegal to call operator delete[]
1807  // on this thing, so it doesn't matter if we allocate extra space or not.
1808  if (ops.isAmbiguous()) return false;
1809 
1810  // C++17 [expr.delete]p10:
1811  // If the deallocation functions have class scope, the one without a
1812  // parameter of type std::size_t is selected.
1813  auto Best = resolveDeallocationOverload(
1814  S, ops, /*WantSize*/false,
1815  /*WantAlign*/hasNewExtendedAlignment(S, allocType));
1816  return Best && Best.HasSizeT;
1817 }
1818 
1819 /// Parsed a C++ 'new' expression (C++ 5.3.4).
1820 ///
1821 /// E.g.:
1822 /// @code new (memory) int[size][4] @endcode
1823 /// or
1824 /// @code ::new Foo(23, "hello") @endcode
1825 ///
1826 /// \param StartLoc The first location of the expression.
1827 /// \param UseGlobal True if 'new' was prefixed with '::'.
1828 /// \param PlacementLParen Opening paren of the placement arguments.
1829 /// \param PlacementArgs Placement new arguments.
1830 /// \param PlacementRParen Closing paren of the placement arguments.
1831 /// \param TypeIdParens If the type is in parens, the source range.
1832 /// \param D The type to be allocated, as well as array dimensions.
1833 /// \param Initializer The initializing expression or initializer-list, or null
1834 /// if there is none.
1835 ExprResult
1836 Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
1837  SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
1838  SourceLocation PlacementRParen, SourceRange TypeIdParens,
1839  Declarator &D, Expr *Initializer) {
1840  Optional<Expr *> ArraySize;
1841  // If the specified type is an array, unwrap it and save the expression.
1842  if (D.getNumTypeObjects() > 0 &&
1844  DeclaratorChunk &Chunk = D.getTypeObject(0);
1845  if (D.getDeclSpec().hasAutoTypeSpec())
1846  return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
1847  << D.getSourceRange());
1848  if (Chunk.Arr.hasStatic)
1849  return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
1850  << D.getSourceRange());
1851  if (!Chunk.Arr.NumElts && !Initializer)
1852  return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
1853  << D.getSourceRange());
1854 
1855  ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
1856  D.DropFirstTypeObject();
1857  }
1858 
1859  // Every dimension shall be of constant size.
1860  if (ArraySize) {
1861  for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
1863  break;
1864 
1866  if (Expr *NumElts = (Expr *)Array.NumElts) {
1867  if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
1868  // FIXME: GCC permits constant folding here. We should either do so consistently
1869  // or not do so at all, rather than changing behavior in C++14 onwards.
1870  if (getLangOpts().CPlusPlus14) {
1871  // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
1872  // shall be a converted constant expression (5.19) of type std::size_t
1873  // and shall evaluate to a strictly positive value.
1875  Array.NumElts
1878  .get();
1879  } else {
1880  Array.NumElts =
1882  NumElts, nullptr, diag::err_new_array_nonconst, AllowFold)
1883  .get();
1884  }
1885  if (!Array.NumElts)
1886  return ExprError();
1887  }
1888  }
1889  }
1890  }
1891 
1892  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
1893  QualType AllocType = TInfo->getType();
1894  if (D.isInvalidType())
1895  return ExprError();
1896 
1897  SourceRange DirectInitRange;
1898  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
1899  DirectInitRange = List->getSourceRange();
1900 
1901  return BuildCXXNew(SourceRange(StartLoc, D.getEndLoc()), UseGlobal,
1902  PlacementLParen, PlacementArgs, PlacementRParen,
1903  TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange,
1904  Initializer);
1905 }
1906 
1908  Expr *Init) {
1909  if (!Init)
1910  return true;
1911  if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
1912  return PLE->getNumExprs() == 0;
1913  if (isa<ImplicitValueInitExpr>(Init))
1914  return true;
1915  else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
1916  return !CCE->isListInitialization() &&
1917  CCE->getConstructor()->isDefaultConstructor();
1918  else if (Style == CXXNewExpr::ListInit) {
1919  assert(isa<InitListExpr>(Init) &&
1920  "Shouldn't create list CXXConstructExprs for arrays.");
1921  return true;
1922  }
1923  return false;
1924 }
1925 
1926 bool
1928  if (!getLangOpts().AlignedAllocationUnavailable)
1929  return false;
1930  if (FD.isDefined())
1931  return false;
1932  Optional<unsigned> AlignmentParam;
1933  if (FD.isReplaceableGlobalAllocationFunction(&AlignmentParam) &&
1934  AlignmentParam)
1935  return true;
1936  return false;
1937 }
1938 
1939 // Emit a diagnostic if an aligned allocation/deallocation function that is not
1940 // implemented in the standard library is selected.
1942  SourceLocation Loc) {
1944  const llvm::Triple &T = getASTContext().getTargetInfo().getTriple();
1945  StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling(
1946  getASTContext().getTargetInfo().getPlatformName());
1947  VersionTuple OSVersion = alignedAllocMinVersion(T.getOS());
1948 
1950  bool IsDelete = Kind == OO_Delete || Kind == OO_Array_Delete;
1951  Diag(Loc, diag::err_aligned_allocation_unavailable)
1952  << IsDelete << FD.getType().getAsString() << OSName
1953  << OSVersion.getAsString() << OSVersion.empty();
1954  Diag(Loc, diag::note_silence_aligned_allocation_unavailable);
1955  }
1956 }
1957 
1958 ExprResult
1959 Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
1960  SourceLocation PlacementLParen,
1961  MultiExprArg PlacementArgs,
1962  SourceLocation PlacementRParen,
1963  SourceRange TypeIdParens,
1964  QualType AllocType,
1965  TypeSourceInfo *AllocTypeInfo,
1966  Optional<Expr *> ArraySize,
1967  SourceRange DirectInitRange,
1968  Expr *Initializer) {
1969  SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
1970  SourceLocation StartLoc = Range.getBegin();
1971 
1973  if (DirectInitRange.isValid()) {
1974  assert(Initializer && "Have parens but no initializer.");
1975  initStyle = CXXNewExpr::CallInit;
1976  } else if (Initializer && isa<InitListExpr>(Initializer))
1977  initStyle = CXXNewExpr::ListInit;
1978  else {
1979  assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||
1980  isa<CXXConstructExpr>(Initializer)) &&
1981  "Initializer expression that cannot have been implicitly created.");
1982  initStyle = CXXNewExpr::NoInit;
1983  }
1984 
1985  MultiExprArg Exprs(&Initializer, Initializer ? 1 : 0);
1986  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
1987  assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init");
1988  Exprs = MultiExprArg(List->getExprs(), List->getNumExprs());
1989  }
1990 
1991  // C++11 [expr.new]p15:
1992  // A new-expression that creates an object of type T initializes that
1993  // object as follows:
1995  // - If the new-initializer is omitted, the object is default-
1996  // initialized (8.5); if no initialization is performed,
1997  // the object has indeterminate value
1998  = initStyle == CXXNewExpr::NoInit
2000  // - Otherwise, the new-initializer is interpreted according to
2001  // the
2002  // initialization rules of 8.5 for direct-initialization.
2003  : initStyle == CXXNewExpr::ListInit
2005  TypeRange.getBegin(), Initializer->getBeginLoc(),
2006  Initializer->getEndLoc())
2008  DirectInitRange.getBegin(),
2009  DirectInitRange.getEnd());
2010 
2011  // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
2012  auto *Deduced = AllocType->getContainedDeducedType();
2013  if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
2014  if (ArraySize)
2015  return ExprError(
2016  Diag(*ArraySize ? (*ArraySize)->getExprLoc() : TypeRange.getBegin(),
2017  diag::err_deduced_class_template_compound_type)
2018  << /*array*/ 2
2019  << (*ArraySize ? (*ArraySize)->getSourceRange() : TypeRange));
2020 
2021  InitializedEntity Entity
2022  = InitializedEntity::InitializeNew(StartLoc, AllocType);
2024  AllocTypeInfo, Entity, Kind, Exprs);
2025  if (AllocType.isNull())
2026  return ExprError();
2027  } else if (Deduced) {
2028  MultiExprArg Inits = Exprs;
2029  bool Braced = (initStyle == CXXNewExpr::ListInit);
2030  if (Braced) {
2031  auto *ILE = cast<InitListExpr>(Exprs[0]);
2032  Inits = MultiExprArg(ILE->getInits(), ILE->getNumInits());
2033  }
2034 
2035  if (initStyle == CXXNewExpr::NoInit || Inits.empty())
2036  return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
2037  << AllocType << TypeRange);
2038  if (Inits.size() > 1) {
2039  Expr *FirstBad = Inits[1];
2040  return ExprError(Diag(FirstBad->getBeginLoc(),
2041  diag::err_auto_new_ctor_multiple_expressions)
2042  << AllocType << TypeRange);
2043  }
2044  if (Braced && !getLangOpts().CPlusPlus17)
2045  Diag(Initializer->getBeginLoc(), diag::ext_auto_new_list_init)
2046  << AllocType << TypeRange;
2047  Expr *Deduce = Inits[0];
2048  if (isa<InitListExpr>(Deduce))
2049  return ExprError(
2050  Diag(Deduce->getBeginLoc(), diag::err_auto_expr_init_paren_braces)
2051  << Braced << AllocType << TypeRange);
2053  TemplateDeductionInfo Info(Deduce->getExprLoc());
2054  TemplateDeductionResult Result =
2055  DeduceAutoType(AllocTypeInfo->getTypeLoc(), Deduce, DeducedType, Info);
2056  if (Result != TDK_Success && Result != TDK_AlreadyDiagnosed)
2057  return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
2058  << AllocType << Deduce->getType() << TypeRange
2059  << Deduce->getSourceRange());
2060  if (DeducedType.isNull()) {
2061  assert(Result == TDK_AlreadyDiagnosed);
2062  return ExprError();
2063  }
2064  AllocType = DeducedType;
2065  }
2066 
2067  // Per C++0x [expr.new]p5, the type being constructed may be a
2068  // typedef of an array type.
2069  if (!ArraySize) {
2070  if (const ConstantArrayType *Array
2071  = Context.getAsConstantArrayType(AllocType)) {
2072  ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
2073  Context.getSizeType(),
2074  TypeRange.getEnd());
2075  AllocType = Array->getElementType();
2076  }
2077  }
2078 
2079  if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
2080  return ExprError();
2081 
2082  if (ArraySize && !checkArrayElementAlignment(AllocType, TypeRange.getBegin()))
2083  return ExprError();
2084 
2085  // In ARC, infer 'retaining' for the allocated
2086  if (getLangOpts().ObjCAutoRefCount &&
2087  AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
2088  AllocType->isObjCLifetimeType()) {
2089  AllocType = Context.getLifetimeQualifiedType(AllocType,
2090  AllocType->getObjCARCImplicitLifetime());
2091  }
2092 
2093  QualType ResultType = Context.getPointerType(AllocType);
2094 
2095  if (ArraySize && *ArraySize &&
2096  (*ArraySize)->getType()->isNonOverloadPlaceholderType()) {
2097  ExprResult result = CheckPlaceholderExpr(*ArraySize);
2098  if (result.isInvalid()) return ExprError();
2099  ArraySize = result.get();
2100  }
2101  // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
2102  // integral or enumeration type with a non-negative value."
2103  // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
2104  // enumeration type, or a class type for which a single non-explicit
2105  // conversion function to integral or unscoped enumeration type exists.
2106  // C++1y [expr.new]p6: The expression [...] is implicitly converted to
2107  // std::size_t.
2108  llvm::Optional<uint64_t> KnownArraySize;
2109  if (ArraySize && *ArraySize && !(*ArraySize)->isTypeDependent()) {
2110  ExprResult ConvertedSize;
2111  if (getLangOpts().CPlusPlus14) {
2112  assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?");
2113 
2114  ConvertedSize = PerformImplicitConversion(*ArraySize, Context.getSizeType(),
2115  AA_Converting);
2116 
2117  if (!ConvertedSize.isInvalid() &&
2118  (*ArraySize)->getType()->getAs<RecordType>())
2119  // Diagnose the compatibility of this conversion.
2120  Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
2121  << (*ArraySize)->getType() << 0 << "'size_t'";
2122  } else {
2123  class SizeConvertDiagnoser : public ICEConvertDiagnoser {
2124  protected:
2125  Expr *ArraySize;
2126 
2127  public:
2128  SizeConvertDiagnoser(Expr *ArraySize)
2129  : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
2130  ArraySize(ArraySize) {}
2131 
2132  SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
2133  QualType T) override {
2134  return S.Diag(Loc, diag::err_array_size_not_integral)
2135  << S.getLangOpts().CPlusPlus11 << T;
2136  }
2137 
2138  SemaDiagnosticBuilder diagnoseIncomplete(
2139  Sema &S, SourceLocation Loc, QualType T) override {
2140  return S.Diag(Loc, diag::err_array_size_incomplete_type)
2141  << T << ArraySize->getSourceRange();
2142  }
2143 
2144  SemaDiagnosticBuilder diagnoseExplicitConv(
2145  Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
2146  return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
2147  }
2148 
2149  SemaDiagnosticBuilder noteExplicitConv(
2150  Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
2151  return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
2152  << ConvTy->isEnumeralType() << ConvTy;
2153  }
2154 
2155  SemaDiagnosticBuilder diagnoseAmbiguous(
2156  Sema &S, SourceLocation Loc, QualType T) override {
2157  return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
2158  }
2159 
2160  SemaDiagnosticBuilder noteAmbiguous(
2161  Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
2162  return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
2163  << ConvTy->isEnumeralType() << ConvTy;
2164  }
2165 
2166  SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
2167  QualType T,
2168  QualType ConvTy) override {
2169  return S.Diag(Loc,
2170  S.getLangOpts().CPlusPlus11
2171  ? diag::warn_cxx98_compat_array_size_conversion
2172  : diag::ext_array_size_conversion)
2173  << T << ConvTy->isEnumeralType() << ConvTy;
2174  }
2175  } SizeDiagnoser(*ArraySize);
2176 
2177  ConvertedSize = PerformContextualImplicitConversion(StartLoc, *ArraySize,
2178  SizeDiagnoser);
2179  }
2180  if (ConvertedSize.isInvalid())
2181  return ExprError();
2182 
2183  ArraySize = ConvertedSize.get();
2184  QualType SizeType = (*ArraySize)->getType();
2185 
2186  if (!SizeType->isIntegralOrUnscopedEnumerationType())
2187  return ExprError();
2188 
2189  // C++98 [expr.new]p7:
2190  // The expression in a direct-new-declarator shall have integral type
2191  // with a non-negative value.
2192  //
2193  // Let's see if this is a constant < 0. If so, we reject it out of hand,
2194  // per CWG1464. Otherwise, if it's not a constant, we must have an
2195  // unparenthesized array type.
2196 
2197  // We've already performed any required implicit conversion to integer or
2198  // unscoped enumeration type.
2199  // FIXME: Per CWG1464, we are required to check the value prior to
2200  // converting to size_t. This will never find a negative array size in
2201  // C++14 onwards, because Value is always unsigned here!
2203  (*ArraySize)->getIntegerConstantExpr(Context)) {
2204  if (Value->isSigned() && Value->isNegative()) {
2205  return ExprError(Diag((*ArraySize)->getBeginLoc(),
2206  diag::err_typecheck_negative_array_size)
2207  << (*ArraySize)->getSourceRange());
2208  }
2209 
2210  if (!AllocType->isDependentType()) {
2211  unsigned ActiveSizeBits =
2213  if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
2214  return ExprError(
2215  Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large)
2216  << toString(*Value, 10) << (*ArraySize)->getSourceRange());
2217  }
2218 
2219  KnownArraySize = Value->getZExtValue();
2220  } else if (TypeIdParens.isValid()) {
2221  // Can't have dynamic array size when the type-id is in parentheses.
2222  Diag((*ArraySize)->getBeginLoc(), diag::ext_new_paren_array_nonconst)
2223  << (*ArraySize)->getSourceRange()
2224  << FixItHint::CreateRemoval(TypeIdParens.getBegin())
2225  << FixItHint::CreateRemoval(TypeIdParens.getEnd());
2226 
2227  TypeIdParens = SourceRange();
2228  }
2229 
2230  // Note that we do *not* convert the argument in any way. It can
2231  // be signed, larger than size_t, whatever.
2232  }
2233 
2234  FunctionDecl *OperatorNew = nullptr;
2235  FunctionDecl *OperatorDelete = nullptr;
2236  unsigned Alignment =
2237  AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType);
2238  unsigned NewAlignment = Context.getTargetInfo().getNewAlign();
2239  bool PassAlignment = getLangOpts().AlignedAllocation &&
2240  Alignment > NewAlignment;
2241 
2243  if (!AllocType->isDependentType() &&
2244  !Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
2246  StartLoc, SourceRange(PlacementLParen, PlacementRParen), Scope, Scope,
2247  AllocType, ArraySize.has_value(), PassAlignment, PlacementArgs,
2248  OperatorNew, OperatorDelete))
2249  return ExprError();
2250 
2251  // If this is an array allocation, compute whether the usual array
2252  // deallocation function for the type has a size_t parameter.
2253  bool UsualArrayDeleteWantsSize = false;
2254  if (ArraySize && !AllocType->isDependentType())
2255  UsualArrayDeleteWantsSize =
2256  doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);
2257 
2258  SmallVector<Expr *, 8> AllPlaceArgs;
2259  if (OperatorNew) {
2260  auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();
2261  VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
2263 
2264  // We've already converted the placement args, just fill in any default
2265  // arguments. Skip the first parameter because we don't have a corresponding
2266  // argument. Skip the second parameter too if we're passing in the
2267  // alignment; we've already filled it in.
2268  unsigned NumImplicitArgs = PassAlignment ? 2 : 1;
2269  if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto,
2270  NumImplicitArgs, PlacementArgs, AllPlaceArgs,
2271  CallType))
2272  return ExprError();
2273 
2274  if (!AllPlaceArgs.empty())
2275  PlacementArgs = AllPlaceArgs;
2276 
2277  // We would like to perform some checking on the given `operator new` call,
2278  // but the PlacementArgs does not contain the implicit arguments,
2279  // namely allocation size and maybe allocation alignment,
2280  // so we need to conjure them.
2281 
2282  QualType SizeTy = Context.getSizeType();
2283  unsigned SizeTyWidth = Context.getTypeSize(SizeTy);
2284 
2285  llvm::APInt SingleEltSize(
2286  SizeTyWidth, Context.getTypeSizeInChars(AllocType).getQuantity());
2287 
2288  // How many bytes do we want to allocate here?
2289  llvm::Optional<llvm::APInt> AllocationSize;
2290  if (!ArraySize && !AllocType->isDependentType()) {
2291  // For non-array operator new, we only want to allocate one element.
2292  AllocationSize = SingleEltSize;
2293  } else if (KnownArraySize && !AllocType->isDependentType()) {
2294  // For array operator new, only deal with static array size case.
2295  bool Overflow;
2296  AllocationSize = llvm::APInt(SizeTyWidth, *KnownArraySize)
2297  .umul_ov(SingleEltSize, Overflow);
2298  (void)Overflow;
2299  assert(
2300  !Overflow &&
2301  "Expected that all the overflows would have been handled already.");
2302  }
2303 
2304  IntegerLiteral AllocationSizeLiteral(
2305  Context, AllocationSize.value_or(llvm::APInt::getZero(SizeTyWidth)),
2306  SizeTy, SourceLocation());
2307  // Otherwise, if we failed to constant-fold the allocation size, we'll
2308  // just give up and pass-in something opaque, that isn't a null pointer.
2309  OpaqueValueExpr OpaqueAllocationSize(SourceLocation(), SizeTy, VK_PRValue,
2310  OK_Ordinary, /*SourceExpr=*/nullptr);
2311 
2312  // Let's synthesize the alignment argument in case we will need it.
2313  // Since we *really* want to allocate these on stack, this is slightly ugly
2314  // because there might not be a `std::align_val_t` type.
2316  QualType AlignValT =
2318  IntegerLiteral AlignmentLiteral(
2319  Context,
2321  Alignment / Context.getCharWidth()),
2322  SizeTy, SourceLocation());
2323  ImplicitCastExpr DesiredAlignment(ImplicitCastExpr::OnStack, AlignValT,
2324  CK_IntegralCast, &AlignmentLiteral,
2326 
2327  // Adjust placement args by prepending conjured size and alignment exprs.
2329  CallArgs.reserve(NumImplicitArgs + PlacementArgs.size());
2330  CallArgs.emplace_back(AllocationSize
2331  ? static_cast<Expr *>(&AllocationSizeLiteral)
2332  : &OpaqueAllocationSize);
2333  if (PassAlignment)
2334  CallArgs.emplace_back(&DesiredAlignment);
2335  CallArgs.insert(CallArgs.end(), PlacementArgs.begin(), PlacementArgs.end());
2336 
2337  DiagnoseSentinelCalls(OperatorNew, PlacementLParen, CallArgs);
2338 
2339  checkCall(OperatorNew, Proto, /*ThisArg=*/nullptr, CallArgs,
2340  /*IsMemberFunction=*/false, StartLoc, Range, CallType);
2341 
2342  // Warn if the type is over-aligned and is being allocated by (unaligned)
2343  // global operator new.
2344  if (PlacementArgs.empty() && !PassAlignment &&
2345  (OperatorNew->isImplicit() ||
2346  (OperatorNew->getBeginLoc().isValid() &&
2347  getSourceManager().isInSystemHeader(OperatorNew->getBeginLoc())))) {
2348  if (Alignment > NewAlignment)
2349  Diag(StartLoc, diag::warn_overaligned_type)
2350  << AllocType
2351  << unsigned(Alignment / Context.getCharWidth())
2352  << unsigned(NewAlignment / Context.getCharWidth());
2353  }
2354  }
2355 
2356  // Array 'new' can't have any initializers except empty parentheses.
2357  // Initializer lists are also allowed, in C++11. Rely on the parser for the
2358  // dialect distinction.
2359  if (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) {
2360  SourceRange InitRange(Exprs.front()->getBeginLoc(),
2361  Exprs.back()->getEndLoc());
2362  Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
2363  return ExprError();
2364  }
2365 
2366  // If we can perform the initialization, and we've not already done so,
2367  // do it now.
2368  if (!AllocType->isDependentType() &&
2370  // The type we initialize is the complete type, including the array bound.
2371  QualType InitType;
2372  if (KnownArraySize)
2373  InitType = Context.getConstantArrayType(
2374  AllocType,
2376  *KnownArraySize),
2377  *ArraySize, ArrayType::Normal, 0);
2378  else if (ArraySize)
2379  InitType =
2381  else
2382  InitType = AllocType;
2383 
2384  InitializedEntity Entity
2385  = InitializedEntity::InitializeNew(StartLoc, InitType);
2386  InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
2387  ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, Exprs);
2388  if (FullInit.isInvalid())
2389  return ExprError();
2390 
2391  // FullInit is our initializer; strip off CXXBindTemporaryExprs, because
2392  // we don't want the initialized object to be destructed.
2393  // FIXME: We should not create these in the first place.
2394  if (CXXBindTemporaryExpr *Binder =
2395  dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
2396  FullInit = Binder->getSubExpr();
2397 
2398  Initializer = FullInit.get();
2399 
2400  // FIXME: If we have a KnownArraySize, check that the array bound of the
2401  // initializer is no greater than that constant value.
2402 
2403  if (ArraySize && !*ArraySize) {
2404  auto *CAT = Context.getAsConstantArrayType(Initializer->getType());
2405  if (CAT) {
2406  // FIXME: Track that the array size was inferred rather than explicitly
2407  // specified.
2408  ArraySize = IntegerLiteral::Create(
2409  Context, CAT->getSize(), Context.getSizeType(), TypeRange.getEnd());
2410  } else {
2411  Diag(TypeRange.getEnd(), diag::err_new_array_size_unknown_from_init)
2412  << Initializer->getSourceRange();
2413  }
2414  }
2415  }
2416 
2417  // Mark the new and delete operators as referenced.
2418  if (OperatorNew) {
2419  if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
2420  return ExprError();
2421  MarkFunctionReferenced(StartLoc, OperatorNew);
2422  }
2423  if (OperatorDelete) {
2424  if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
2425  return ExprError();
2426  MarkFunctionReferenced(StartLoc, OperatorDelete);
2427  }
2428 
2429  return CXXNewExpr::Create(Context, UseGlobal, OperatorNew, OperatorDelete,
2430  PassAlignment, UsualArrayDeleteWantsSize,
2431  PlacementArgs, TypeIdParens, ArraySize, initStyle,
2432  Initializer, ResultType, AllocTypeInfo, Range,
2433  DirectInitRange);
2434 }
2435 
2436 /// Checks that a type is suitable as the allocated type
2437 /// in a new-expression.
2439  SourceRange R) {
2440  // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
2441  // abstract class type or array thereof.
2442  if (AllocType->isFunctionType())
2443  return Diag(Loc, diag::err_bad_new_type)
2444  << AllocType << 0 << R;
2445  else if (AllocType->isReferenceType())
2446  return Diag(Loc, diag::err_bad_new_type)
2447  << AllocType << 1 << R;
2448  else if (!AllocType->isDependentType() &&
2450  Loc, AllocType, diag::err_new_incomplete_or_sizeless_type, R))
2451  return true;
2452  else if (RequireNonAbstractType(Loc, AllocType,
2453  diag::err_allocation_of_abstract_type))
2454  return true;
2455  else if (AllocType->isVariablyModifiedType())
2456  return Diag(Loc, diag::err_variably_modified_new_type)
2457  << AllocType;
2458  else if (AllocType.getAddressSpace() != LangAS::Default &&
2459  !getLangOpts().OpenCLCPlusPlus)
2460  return Diag(Loc, diag::err_address_space_qualified_new)
2461  << AllocType.getUnqualifiedType()
2463  else if (getLangOpts().ObjCAutoRefCount) {
2464  if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
2465  QualType BaseAllocType = Context.getBaseElementType(AT);
2466  if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
2467  BaseAllocType->isObjCLifetimeType())
2468  return Diag(Loc, diag::err_arc_new_array_without_ownership)
2469  << BaseAllocType;
2470  }
2471  }
2472 
2473  return false;
2474 }
2475 
2478  bool &PassAlignment, FunctionDecl *&Operator,
2479  OverloadCandidateSet *AlignedCandidates, Expr *AlignArg, bool Diagnose) {
2480  OverloadCandidateSet Candidates(R.getNameLoc(),
2482  for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
2483  Alloc != AllocEnd; ++Alloc) {
2484  // Even member operator new/delete are implicitly treated as
2485  // static, so don't use AddMemberCandidate.
2486  NamedDecl *D = (*Alloc)->getUnderlyingDecl();
2487 
2488  if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
2489  S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
2490  /*ExplicitTemplateArgs=*/nullptr, Args,
2491  Candidates,
2492  /*SuppressUserConversions=*/false);
2493  continue;
2494  }
2495 
2496  FunctionDecl *Fn = cast<FunctionDecl>(D);
2497  S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
2498  /*SuppressUserConversions=*/false);
2499  }
2500 
2501  // Do the resolution.
2503  switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
2504  case OR_Success: {
2505  // Got one!
2506  FunctionDecl *FnDecl = Best->Function;
2507  if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(),
2508  Best->FoundDecl) == Sema::AR_inaccessible)
2509  return true;
2510 
2511  Operator = FnDecl;
2512  return false;
2513  }
2514 
2515  case OR_No_Viable_Function:
2516  // C++17 [expr.new]p13:
2517  // If no matching function is found and the allocated object type has
2518  // new-extended alignment, the alignment argument is removed from the
2519  // argument list, and overload resolution is performed again.
2520  if (PassAlignment) {
2521  PassAlignment = false;
2522  AlignArg = Args[1];
2523  Args.erase(Args.begin() + 1);
2524  return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2525  Operator, &Candidates, AlignArg,
2526  Diagnose);
2527  }
2528 
2529  // MSVC will fall back on trying to find a matching global operator new
2530  // if operator new[] cannot be found. Also, MSVC will leak by not
2531  // generating a call to operator delete or operator delete[], but we
2532  // will not replicate that bug.
2533  // FIXME: Find out how this interacts with the std::align_val_t fallback
2534  // once MSVC implements it.
2535  if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New &&
2536  S.Context.getLangOpts().MSVCCompat) {
2537  R.clear();
2540  // FIXME: This will give bad diagnostics pointing at the wrong functions.
2541  return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2542  Operator, /*Candidates=*/nullptr,
2543  /*AlignArg=*/nullptr, Diagnose);
2544  }
2545 
2546  if (Diagnose) {
2547  // If this is an allocation of the form 'new (p) X' for some object
2548  // pointer p (or an expression that will decay to such a pointer),
2549  // diagnose the missing inclusion of <new>.
2550  if (!R.isClassLookup() && Args.size() == 2 &&
2551  (Args[1]->getType()->isObjectPointerType() ||
2552  Args[1]->getType()->isArrayType())) {
2553  S.Diag(R.getNameLoc(), diag::err_need_header_before_placement_new)
2554  << R.getLookupName() << Range;
2555  // Listing the candidates is unlikely to be useful; skip it.
2556  return true;
2557  }
2558 
2559  // Finish checking all candidates before we note any. This checking can
2560  // produce additional diagnostics so can't be interleaved with our
2561  // emission of notes.
2562  //
2563  // For an aligned allocation, separately check the aligned and unaligned
2564  // candidates with their respective argument lists.
2567  llvm::SmallVector<Expr*, 4> AlignedArgs;
2568  if (AlignedCandidates) {
2569  auto IsAligned = [](OverloadCandidate &C) {
2570  return C.Function->getNumParams() > 1 &&
2571  C.Function->getParamDecl(1)->getType()->isAlignValT();
2572  };
2573  auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); };
2574 
2575  AlignedArgs.reserve(Args.size() + 1);
2576  AlignedArgs.push_back(Args[0]);
2577  AlignedArgs.push_back(AlignArg);
2578  AlignedArgs.append(Args.begin() + 1, Args.end());
2579  AlignedCands = AlignedCandidates->CompleteCandidates(
2580  S, OCD_AllCandidates, AlignedArgs, R.getNameLoc(), IsAligned);
2581 
2582  Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
2583  R.getNameLoc(), IsUnaligned);
2584  } else {
2585  Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args,
2586  R.getNameLoc());
2587  }
2588 
2589  S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call)
2590  << R.getLookupName() << Range;
2591  if (AlignedCandidates)
2592  AlignedCandidates->NoteCandidates(S, AlignedArgs, AlignedCands, "",
2593  R.getNameLoc());
2594  Candidates.NoteCandidates(S, Args, Cands, "", R.getNameLoc());
2595  }
2596  return true;
2597 
2598  case OR_Ambiguous:
2599  if (Diagnose) {
2600  Candidates.NoteCandidates(
2602  S.PDiag(diag::err_ovl_ambiguous_call)
2603  << R.getLookupName() << Range),
2604  S, OCD_AmbiguousCandidates, Args);
2605  }
2606  return true;
2607 
2608  case OR_Deleted: {
2609  if (Diagnose) {
2610  Candidates.NoteCandidates(
2612  S.PDiag(diag::err_ovl_deleted_call)
2613  << R.getLookupName() << Range),
2614  S, OCD_AllCandidates, Args);
2615  }
2616  return true;
2617  }
2618  }
2619  llvm_unreachable("Unreachable, bad result from BestViableFunction");
2620 }
2621 
2623  AllocationFunctionScope NewScope,
2624  AllocationFunctionScope DeleteScope,
2625  QualType AllocType, bool IsArray,
2626  bool &PassAlignment, MultiExprArg PlaceArgs,
2627  FunctionDecl *&OperatorNew,
2628  FunctionDecl *&OperatorDelete,
2629  bool Diagnose) {
2630  // --- Choosing an allocation function ---
2631  // C++ 5.3.4p8 - 14 & 18
2632  // 1) If looking in AFS_Global scope for allocation functions, only look in
2633  // the global scope. Else, if AFS_Class, only look in the scope of the
2634  // allocated class. If AFS_Both, look in both.
2635  // 2) If an array size is given, look for operator new[], else look for
2636  // operator new.
2637  // 3) The first argument is always size_t. Append the arguments from the
2638  // placement form.
2639 
2640  SmallVector<Expr*, 8> AllocArgs;
2641  AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size());
2642 
2643  // We don't care about the actual value of these arguments.
2644  // FIXME: Should the Sema create the expression and embed it in the syntax
2645  // tree? Or should the consumer just recalculate the value?
2646  // FIXME: Using a dummy value will interact poorly with attribute enable_if.
2647  IntegerLiteral Size(
2648  Context, llvm::APInt::getZero(Context.getTargetInfo().getPointerWidth(0)),
2650  AllocArgs.push_back(&Size);
2651 
2652  QualType AlignValT = Context.VoidTy;
2653  if (PassAlignment) {
2655  AlignValT = Context.getTypeDeclType(getStdAlignValT());
2656  }
2657  CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation());
2658  if (PassAlignment)
2659  AllocArgs.push_back(&Align);
2660 
2661  AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end());
2662 
2663  // C++ [expr.new]p8:
2664  // If the allocated type is a non-array type, the allocation
2665  // function's name is operator new and the deallocation function's
2666  // name is operator delete. If the allocated type is an array
2667  // type, the allocation function's name is operator new[] and the
2668  // deallocation function's name is operator delete[].
2670  IsArray ? OO_Array_New : OO_New);
2671 
2672  QualType AllocElemType = Context.getBaseElementType(AllocType);
2673 
2674  // Find the allocation function.
2675  {
2676  LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName);
2677 
2678  // C++1z [expr.new]p9:
2679  // If the new-expression begins with a unary :: operator, the allocation
2680  // function's name is looked up in the global scope. Otherwise, if the
2681  // allocated type is a class type T or array thereof, the allocation
2682  // function's name is looked up in the scope of T.
2683  if (AllocElemType->isRecordType() && NewScope != AFS_Global)
2684  LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl());
2685 
2686  // We can see ambiguity here if the allocation function is found in
2687  // multiple base classes.
2688  if (R.isAmbiguous())
2689  return true;
2690 
2691  // If this lookup fails to find the name, or if the allocated type is not
2692  // a class type, the allocation function's name is looked up in the
2693  // global scope.
2694  if (R.empty()) {
2695  if (NewScope == AFS_Class)
2696  return true;
2697 
2699  }
2700 
2701  if (getLangOpts().OpenCLCPlusPlus && R.empty()) {
2702  if (PlaceArgs.empty()) {
2703  Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
2704  } else {
2705  Diag(StartLoc, diag::err_openclcxx_placement_new);
2706  }
2707  return true;
2708  }
2709 
2710  assert(!R.empty() && "implicitly declared allocation functions not found");
2711  assert(!R.isAmbiguous() && "global allocation functions are ambiguous");
2712 
2713  // We do our own custom access checks below.
2714  R.suppressDiagnostics();
2715 
2716  if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment,
2717  OperatorNew, /*Candidates=*/nullptr,
2718  /*AlignArg=*/nullptr, Diagnose))
2719  return true;
2720  }
2721 
2722  // We don't need an operator delete if we're running under -fno-exceptions.
2723  if (!getLangOpts().Exceptions) {
2724  OperatorDelete = nullptr;
2725  return false;
2726  }
2727 
2728  // Note, the name of OperatorNew might have been changed from array to
2729  // non-array by resolveAllocationOverload.
2731  OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New
2732  ? OO_Array_Delete
2733  : OO_Delete);
2734 
2735  // C++ [expr.new]p19:
2736  //
2737  // If the new-expression begins with a unary :: operator, the
2738  // deallocation function's name is looked up in the global
2739  // scope. Otherwise, if the allocated type is a class type T or an
2740  // array thereof, the deallocation function's name is looked up in
2741  // the scope of T. If this lookup fails to find the name, or if
2742  // the allocated type is not a class type or array thereof, the
2743  // deallocation function's name is looked up in the global scope.
2744  LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
2745  if (AllocElemType->isRecordType() && DeleteScope != AFS_Global) {
2746  auto *RD =
2747  cast<CXXRecordDecl>(AllocElemType->castAs<RecordType>()->getDecl());
2748  LookupQualifiedName(FoundDelete, RD);
2749  }
2750  if (FoundDelete.isAmbiguous())
2751  return true; // FIXME: clean up expressions?
2752 
2753  // Filter out any destroying operator deletes. We can't possibly call such a
2754  // function in this context, because we're handling the case where the object
2755  // was not successfully constructed.
2756  // FIXME: This is not covered by the language rules yet.
2757  {
2758  LookupResult::Filter Filter = FoundDelete.makeFilter();
2759  while (Filter.hasNext()) {
2760  auto *FD = dyn_cast<FunctionDecl>(Filter.next()->getUnderlyingDecl());
2761  if (FD && FD->isDestroyingOperatorDelete())
2762  Filter.erase();
2763  }
2764  Filter.done();
2765  }
2766 
2767  bool FoundGlobalDelete = FoundDelete.empty();
2768  if (FoundDelete.empty()) {
2769  FoundDelete.clear(LookupOrdinaryName);
2770 
2771  if (DeleteScope == AFS_Class)
2772  return true;
2773 
2776  }
2777 
2778  FoundDelete.suppressDiagnostics();
2779 
2781 
2782  // Whether we're looking for a placement operator delete is dictated
2783  // by whether we selected a placement operator new, not by whether
2784  // we had explicit placement arguments. This matters for things like
2785  // struct A { void *operator new(size_t, int = 0); ... };
2786  // A *a = new A()
2787  //
2788  // We don't have any definition for what a "placement allocation function"
2789  // is, but we assume it's any allocation function whose
2790  // parameter-declaration-clause is anything other than (size_t).
2791  //
2792  // FIXME: Should (size_t, std::align_val_t) also be considered non-placement?
2793  // This affects whether an exception from the constructor of an overaligned
2794  // type uses the sized or non-sized form of aligned operator delete.
2795  bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 ||
2796  OperatorNew->isVariadic();
2797 
2798  if (isPlacementNew) {
2799  // C++ [expr.new]p20:
2800  // A declaration of a placement deallocation function matches the
2801  // declaration of a placement allocation function if it has the
2802  // same number of parameters and, after parameter transformations
2803  // (8.3.5), all parameter types except the first are
2804  // identical. [...]
2805  //
2806  // To perform this comparison, we compute the function type that
2807  // the deallocation function should have, and use that type both
2808  // for template argument deduction and for comparison purposes.
2809  QualType ExpectedFunctionType;
2810  {
2811  auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>();
2812 
2813  SmallVector<QualType, 4> ArgTypes;
2814  ArgTypes.push_back(Context.VoidPtrTy);
2815  for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
2816  ArgTypes.push_back(Proto->getParamType(I));
2817 
2819  // FIXME: This is not part of the standard's rule.
2820  EPI.Variadic = Proto->isVariadic();
2821 
2822  ExpectedFunctionType
2823  = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
2824  }
2825 
2826  for (LookupResult::iterator D = FoundDelete.begin(),
2827  DEnd = FoundDelete.end();
2828  D != DEnd; ++D) {
2829  FunctionDecl *Fn = nullptr;
2830  if (FunctionTemplateDecl *FnTmpl =
2831  dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
2832  // Perform template argument deduction to try to match the
2833  // expected function type.
2834  TemplateDeductionInfo Info(StartLoc);
2835  if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
2836  Info))
2837  continue;
2838  } else
2839  Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());
2840 
2842  ExpectedFunctionType,
2843  /*AdjustExcpetionSpec*/true),
2844  ExpectedFunctionType))
2845  Matches.push_back(std::make_pair(D.getPair(), Fn));
2846  }
2847 
2848  if (getLangOpts().CUDA)
2849  EraseUnwantedCUDAMatches(getCurFunctionDecl(/*AllowLambda=*/true),
2850  Matches);
2851  } else {
2852  // C++1y [expr.new]p22:
2853  // For a non-placement allocation function, the normal deallocation
2854  // function lookup is used
2855  //
2856  // Per [expr.delete]p10, this lookup prefers a member operator delete
2857  // without a size_t argument, but prefers a non-member operator delete
2858  // with a size_t where possible (which it always is in this case).
2860  UsualDeallocFnInfo Selected = resolveDeallocationOverload(
2861  *this, FoundDelete, /*WantSize*/ FoundGlobalDelete,
2862  /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType),
2863  &BestDeallocFns);
2864  if (Selected)
2865  Matches.push_back(std::make_pair(Selected.Found, Selected.FD));
2866  else {
2867  // If we failed to select an operator, all remaining functions are viable
2868  // but ambiguous.
2869  for (auto Fn : BestDeallocFns)
2870  Matches.push_back(std::make_pair(Fn.Found, Fn.FD));
2871  }
2872  }
2873 
2874  // C++ [expr.new]p20:
2875  // [...] If the lookup finds a single matching deallocation
2876  // function, that function will be called; otherwise, no
2877  // deallocation function will be called.
2878  if (Matches.size() == 1) {
2879  OperatorDelete = Matches[0].second;
2880 
2881  // C++1z [expr.new]p23:
2882  // If the lookup finds a usual deallocation function (3.7.4.2)
2883  // with a parameter of type std::size_t and that function, considered
2884  // as a placement deallocation function, would have been
2885  // selected as a match for the allocation function, the program
2886  // is ill-formed.
2887  if (getLangOpts().CPlusPlus11 && isPlacementNew &&
2888  isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
2889  UsualDeallocFnInfo Info(*this,
2890  DeclAccessPair::make(OperatorDelete, AS_public));
2891  // Core issue, per mail to core reflector, 2016-10-09:
2892  // If this is a member operator delete, and there is a corresponding
2893  // non-sized member operator delete, this isn't /really/ a sized
2894  // deallocation function, it just happens to have a size_t parameter.
2895  bool IsSizedDelete = Info.HasSizeT;
2896  if (IsSizedDelete && !FoundGlobalDelete) {
2897  auto NonSizedDelete =
2898  resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false,
2899  /*WantAlign*/Info.HasAlignValT);
2900  if (NonSizedDelete && !NonSizedDelete.HasSizeT &&
2901  NonSizedDelete.HasAlignValT == Info.HasAlignValT)
2902  IsSizedDelete = false;
2903  }
2904 
2905  if (IsSizedDelete) {
2906  SourceRange R = PlaceArgs.empty()
2907  ? SourceRange()
2908  : SourceRange(PlaceArgs.front()->getBeginLoc(),
2909  PlaceArgs.back()->getEndLoc());
2910  Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R;
2911  if (!OperatorDelete->isImplicit())
2912  Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
2913  << DeleteName;
2914  }
2915  }
2916 
2917  CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
2918  Matches[0].first);
2919  } else if (!Matches.empty()) {
2920  // We found multiple suitable operators. Per [expr.new]p20, that means we
2921  // call no 'operator delete' function, but we should at least warn the user.
2922  // FIXME: Suppress this warning if the construction cannot throw.
2923  Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found)
2924  << DeleteName << AllocElemType;
2925 
2926  for (auto &Match : Matches)
2927  Diag(Match.second->getLocation(),
2928  diag::note_member_declared_here) << DeleteName;
2929  }
2930 
2931  return false;
2932 }
2933 
2934 /// DeclareGlobalNewDelete - Declare the global forms of operator new and
2935 /// delete. These are:
2936 /// @code
2937 /// // C++03:
2938 /// void* operator new(std::size_t) throw(std::bad_alloc);
2939 /// void* operator new[](std::size_t) throw(std::bad_alloc);
2940 /// void operator delete(void *) throw();
2941 /// void operator delete[](void *) throw();
2942 /// // C++11:
2943 /// void* operator new(std::size_t);
2944 /// void* operator new[](std::size_t);
2945 /// void operator delete(void *) noexcept;
2946 /// void operator delete[](void *) noexcept;
2947 /// // C++1y:
2948 /// void* operator new(std::size_t);
2949 /// void* operator new[](std::size_t);
2950 /// void operator delete(void *) noexcept;
2951 /// void operator delete[](void *) noexcept;
2952 /// void operator delete(void *, std::size_t) noexcept;
2953 /// void operator delete[](void *, std::size_t) noexcept;
2954 /// @endcode
2955 /// Note that the placement and nothrow forms of new are *not* implicitly
2956 /// declared. Their use requires including <new>.
2959  return;
2960 
2961  // The implicitly declared new and delete operators
2962  // are not supported in OpenCL.
2963  if (getLangOpts().OpenCLCPlusPlus)
2964  return;
2965 
2966  // C++ [basic.std.dynamic]p2:
2967  // [...] The following allocation and deallocation functions (18.4) are
2968  // implicitly declared in global scope in each translation unit of a
2969  // program
2970  //
2971  // C++03:
2972  // void* operator new(std::size_t) throw(std::bad_alloc);
2973  // void* operator new[](std::size_t) throw(std::bad_alloc);
2974  // void operator delete(void*) throw();
2975  // void operator delete[](void*) throw();
2976  // C++11:
2977  // void* operator new(std::size_t);
2978  // void* operator new[](std::size_t);
2979  // void operator delete(void*) noexcept;
2980  // void operator delete[](void*) noexcept;
2981  // C++1y:
2982  // void* operator new(std::size_t);
2983  // void* operator new[](std::size_t);
2984  // void operator delete(void*) noexcept;
2985  // void operator delete[](void*) noexcept;
2986  // void operator delete(void*, std::size_t) noexcept;
2987  // void operator delete[](void*, std::size_t) noexcept;
2988  //
2989  // These implicit declarations introduce only the function names operator
2990  // new, operator new[], operator delete, operator delete[].
2991  //
2992  // Here, we need to refer to std::bad_alloc, so we will implicitly declare
2993  // "std" or "bad_alloc" as necessary to form the exception specification.
2994  // However, we do not make these implicit declarations visible to name
2995  // lookup.
2996  if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
2997  // The "std::bad_alloc" class has not yet been declared, so build it
2998  // implicitly.
3002  &PP.getIdentifierTable().get("bad_alloc"),
3003  nullptr);
3004  getStdBadAlloc()->setImplicit(true);
3005  }
3006  if (!StdAlignValT && getLangOpts().AlignedAllocation) {
3007  // The "std::align_val_t" enum class has not yet been declared, so build it
3008  // implicitly.
3009  auto *AlignValT = EnumDecl::Create(
3011  &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true);
3012  AlignValT->setIntegerType(Context.getSizeType());
3013  AlignValT->setPromotionType(Context.getSizeType());
3014  AlignValT->setImplicit(true);
3015  StdAlignValT = AlignValT;
3016  }
3017 
3018  GlobalNewDeleteDeclared = true;
3019 
3021  QualType SizeT = Context.getSizeType();
3022 
3023  auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind,
3024  QualType Return, QualType Param) {
3026  Params.push_back(Param);
3027 
3028  // Create up to four variants of the function (sized/aligned).
3029  bool HasSizedVariant = getLangOpts().SizedDeallocation &&
3030  (Kind == OO_Delete || Kind == OO_Array_Delete);
3031  bool HasAlignedVariant = getLangOpts().AlignedAllocation;
3032 
3033  int NumSizeVariants = (HasSizedVariant ? 2 : 1);
3034  int NumAlignVariants = (HasAlignedVariant ? 2 : 1);
3035  for (int Sized = 0; Sized < NumSizeVariants; ++Sized) {
3036  if (Sized)
3037  Params.push_back(SizeT);
3038 
3039  for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) {
3040  if (Aligned)
3041  Params.push_back(Context.getTypeDeclType(getStdAlignValT()));
3042 
3044  Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params);
3045 
3046  if (Aligned)
3047  Params.pop_back();
3048  }
3049  }
3050  };
3051 
3052  DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT);
3053  DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT);
3054  DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr);
3055  DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr);
3056 }
3057 
3058 /// DeclareGlobalAllocationFunction - Declares a single implicit global
3059 /// allocation function if it doesn't already exist.
3061  QualType Return,
3062  ArrayRef<QualType> Params) {
3064 
3065  // Check if this function is already declared.
3066  DeclContext::lookup_result R = GlobalCtx->lookup(Name);
3067  for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
3068  Alloc != AllocEnd; ++Alloc) {
3069  // Only look at non-template functions, as it is the predefined,
3070  // non-templated allocation function we are trying to declare here.
3071  if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
3072  if (Func->getNumParams() == Params.size()) {
3073  llvm::SmallVector<QualType, 3> FuncParams;
3074  for (auto *P : Func->parameters())
3075  FuncParams.push_back(
3076  Context.getCanonicalType(P->getType().getUnqualifiedType()));
3077  if (llvm::makeArrayRef(FuncParams) == Params) {
3078  // Make the function visible to name lookup, even if we found it in
3079  // an unimported module. It either is an implicitly-declared global
3080  // allocation function, or is suppressing that function.
3081  Func->setVisibleDespiteOwningModule();
3082  return;
3083  }
3084  }
3085  }
3086  }
3087 
3089  /*IsVariadic=*/false, /*IsCXXMethod=*/false, /*IsBuiltin=*/true));
3090 
3091  QualType BadAllocType;
3092  bool HasBadAllocExceptionSpec
3093  = (Name.getCXXOverloadedOperator() == OO_New ||
3094  Name.getCXXOverloadedOperator() == OO_Array_New);
3095  if (HasBadAllocExceptionSpec) {
3096  if (!getLangOpts().CPlusPlus11) {
3097  BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
3098  assert(StdBadAlloc && "Must have std::bad_alloc declared");
3100  EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
3101  }
3102  if (getLangOpts().NewInfallible) {
3104  }
3105  } else {
3106  EPI.ExceptionSpec =
3107  getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
3108  }
3109 
3110  auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) {
3111  QualType FnType = Context.getFunctionType(Return, Params, EPI);
3113  Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, FnType,
3114  /*TInfo=*/nullptr, SC_None, getCurFPFeatures().isFPConstrained(), false,
3115  true);
3116  Alloc->setImplicit();
3117  // Global allocation functions should always be visible.
3119 
3120  if (HasBadAllocExceptionSpec && getLangOpts().NewInfallible)
3121  Alloc->addAttr(
3122  ReturnsNonNullAttr::CreateImplicit(Context, Alloc->getLocation()));
3123 
3124  Alloc->addAttr(VisibilityAttr::CreateImplicit(
3125  Context, LangOpts.GlobalAllocationFunctionVisibilityHidden
3126  ? VisibilityAttr::Hidden
3127  : VisibilityAttr::Default));
3128 
3130  for (QualType T : Params) {
3131  ParamDecls.push_back(ParmVarDecl::Create(
3132  Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T,
3133  /*TInfo=*/nullptr, SC_None, nullptr));
3134  ParamDecls.back()->setImplicit();
3135  }
3136  Alloc->setParams(ParamDecls);
3137  if (ExtraAttr)
3138  Alloc->addAttr(ExtraAttr);
3141  IdResolver.tryAddTopLevelDecl(Alloc, Name);
3142  };
3143 
3144  if (!LangOpts.CUDA)
3145  CreateAllocationFunctionDecl(nullptr);
3146  else {
3147  // Host and device get their own declaration so each can be
3148  // defined or re-declared independently.
3149  CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context));
3150  CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context));
3151  }
3152 }
3153 
3155  bool CanProvideSize,
3156  bool Overaligned,
3157  DeclarationName Name) {
3159 
3160  LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
3162 
3163  // FIXME: It's possible for this to result in ambiguity, through a
3164  // user-declared variadic operator delete or the enable_if attribute. We
3165  // should probably not consider those cases to be usual deallocation
3166  // functions. But for now we just make an arbitrary choice in that case.
3167  auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize,
3168  Overaligned);
3169  assert(Result.FD && "operator delete missing from global scope?");
3170  return Result.FD;
3171 }
3172 
3174  CXXRecordDecl *RD) {
3176 
3177  FunctionDecl *OperatorDelete = nullptr;
3178  if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
3179  return nullptr;
3180  if (OperatorDelete)
3181  return OperatorDelete;
3182 
3183  // If there's no class-specific operator delete, look up the global
3184  // non-array delete.
3186  Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)),
3187  Name);
3188 }
3189 
3191  DeclarationName Name,
3192  FunctionDecl *&Operator, bool Diagnose,
3193  bool WantSize, bool WantAligned) {
3194  LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
3195  // Try to find operator delete/operator delete[] in class scope.
3196  LookupQualifiedName(Found, RD);
3197 
3198  if (Found.isAmbiguous())
3199  return true;
3200 
3201  Found.suppressDiagnostics();
3202 
3203  bool Overaligned =
3204  WantAligned || hasNewExtendedAlignment(*this, Context.getRecordType(RD));
3205 
3206  // C++17 [expr.delete]p10:
3207  // If the deallocation functions have class scope, the one without a
3208  // parameter of type std::size_t is selected.
3210  resolveDeallocationOverload(*this, Found, /*WantSize*/ WantSize,
3211  /*WantAlign*/ Overaligned, &Matches);
3212 
3213  // If we could find an overload, use it.
3214  if (Matches.size() == 1) {
3215  Operator = cast<CXXMethodDecl>(Matches[0].FD);
3216 
3217  // FIXME: DiagnoseUseOfDecl?
3218  if (Operator->isDeleted()) {
3219  if (Diagnose) {
3220  Diag(StartLoc, diag::err_deleted_function_use);
3221  NoteDeletedFunction(Operator);
3222  }
3223  return true;
3224  }
3225 
3226  if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
3227  Matches[0].Found, Diagnose) == AR_inaccessible)
3228  return true;
3229 
3230  return false;
3231  }
3232 
3233  // We found multiple suitable operators; complain about the ambiguity.
3234  // FIXME: The standard doesn't say to do this; it appears that the intent
3235  // is that this should never happen.
3236  if (!Matches.empty()) {
3237  if (Diagnose) {
3238  Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
3239  << Name << RD;
3240  for (auto &Match : Matches)
3241  Diag(Match.FD->getLocation(), diag::note_member_declared_here) << Name;
3242  }
3243  return true;
3244  }
3245 
3246  // We did find operator delete/operator delete[] declarations, but
3247  // none of them were suitable.
3248  if (!Found.empty()) {
3249  if (Diagnose) {
3250  Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
3251  << Name << RD;
3252 
3253  for (NamedDecl *D : Found)
3254  Diag(D->getUnderlyingDecl()->getLocation(),
3255  diag::note_member_declared_here) << Name;
3256  }
3257  return true;
3258  }
3259 
3260  Operator = nullptr;
3261  return false;
3262 }
3263 
3264 namespace {
3265 /// Checks whether delete-expression, and new-expression used for
3266 /// initializing deletee have the same array form.
3267 class MismatchingNewDeleteDetector {
3268 public:
3269  enum MismatchResult {
3270  /// Indicates that there is no mismatch or a mismatch cannot be proven.
3271  NoMismatch,
3272  /// Indicates that variable is initialized with mismatching form of \a new.
3273  VarInitMismatches,
3274  /// Indicates that member is initialized with mismatching form of \a new.
3275  MemberInitMismatches,
3276  /// Indicates that 1 or more constructors' definitions could not been
3277  /// analyzed, and they will be checked again at the end of translation unit.
3278  AnalyzeLater
3279  };
3280 
3281  /// \param EndOfTU True, if this is the final analysis at the end of
3282  /// translation unit. False, if this is the initial analysis at the point
3283  /// delete-expression was encountered.
3284  explicit MismatchingNewDeleteDetector(bool EndOfTU)
3285  : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU),
3286  HasUndefinedConstructors(false) {}
3287 
3288  /// Checks whether pointee of a delete-expression is initialized with
3289  /// matching form of new-expression.
3290  ///
3291  /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the
3292  /// point where delete-expression is encountered, then a warning will be
3293  /// issued immediately. If return value is \c AnalyzeLater at the point where
3294  /// delete-expression is seen, then member will be analyzed at the end of
3295  /// translation unit. \c AnalyzeLater is returned iff at least one constructor
3296  /// couldn't be analyzed. If at least one constructor initializes the member
3297  /// with matching type of new, the return value is \c NoMismatch.
3298  MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE);
3299  /// Analyzes a class member.
3300  /// \param Field Class member to analyze.
3301  /// \param DeleteWasArrayForm Array form-ness of the delete-expression used
3302  /// for deleting the \p Field.
3303  MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm);
3304  FieldDecl *Field;
3305  /// List of mismatching new-expressions used for initialization of the pointee
3307  /// Indicates whether delete-expression was in array form.
3308  bool IsArrayForm;
3309 
3310 private:
3311  const bool EndOfTU;
3312  /// Indicates that there is at least one constructor without body.
3313  bool HasUndefinedConstructors;
3314  /// Returns \c CXXNewExpr from given initialization expression.
3315  /// \param E Expression used for initializing pointee in delete-expression.
3316  /// E can be a single-element \c InitListExpr consisting of new-expression.
3317  const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E);
3318  /// Returns whether member is initialized with mismatching form of
3319  /// \c new either by the member initializer or in-class initialization.
3320  ///
3321  /// If bodies of all constructors are not visible at the end of translation
3322  /// unit or at least one constructor initializes member with the matching
3323  /// form of \c new, mismatch cannot be proven, and this function will return
3324  /// \c NoMismatch.
3325  MismatchResult analyzeMemberExpr(const MemberExpr *ME);
3326  /// Returns whether variable is initialized with mismatching form of
3327  /// \c new.
3328  ///
3329  /// If variable is initialized with matching form of \c new or variable is not
3330  /// initialized with a \c new expression, this function will return true.
3331  /// If variable is initialized with mismatching form of \c new, returns false.
3332  /// \param D Variable to analyze.
3333  bool hasMatchingVarInit(const DeclRefExpr *D);
3334  /// Checks whether the constructor initializes pointee with mismatching
3335  /// form of \c new.
3336  ///
3337  /// Returns true, if member is initialized with matching form of \c new in
3338  /// member initializer list. Returns false, if member is initialized with the
3339  /// matching form of \c new in this constructor's initializer or given
3340  /// constructor isn't defined at the point where delete-expression is seen, or
3341  /// member isn't initialized by the constructor.
3342  bool hasMatchingNewInCtor(const CXXConstructorDecl *CD);
3343  /// Checks whether member is initialized with matching form of
3344  /// \c new in member initializer list.
3345  bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI);
3346  /// Checks whether member is initialized with mismatching form of \c new by
3347  /// in-class initializer.
3348  MismatchResult analyzeInClassInitializer();
3349 };
3350 }
3351 
3352 MismatchingNewDeleteDetector::MismatchResult
3353 MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) {
3354  NewExprs.clear();
3355  assert(DE && "Expected delete-expression");
3356  IsArrayForm = DE->isArrayForm();
3357  const Expr *E = DE->getArgument()->IgnoreParenImpCasts();
3358  if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) {
3359  return analyzeMemberExpr(ME);
3360  } else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) {
3361  if (!hasMatchingVarInit(D))
3362  return VarInitMismatches;
3363  }
3364  return NoMismatch;
3365 }
3366 
3367 const CXXNewExpr *
3368 MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) {
3369  assert(E != nullptr && "Expected a valid initializer expression");
3370  E = E->IgnoreParenImpCasts();
3371  if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) {
3372  if (ILE->getNumInits() == 1)
3373  E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts());
3374  }
3375 
3376  return dyn_cast_or_null<const CXXNewExpr>(E);
3377 }
3378 
3379 bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit(
3380  const CXXCtorInitializer *CI) {
3381  const CXXNewExpr *NE = nullptr;
3382  if (Field == CI->getMember() &&
3383  (NE = getNewExprFromInitListOrExpr(CI->getInit()))) {
3384  if (NE->isArray() == IsArrayForm)
3385  return true;
3386  else
3387  NewExprs.push_back(NE);
3388  }
3389  return false;
3390 }
3391 
3392 bool MismatchingNewDeleteDetector::hasMatchingNewInCtor(
3393  const CXXConstructorDecl *CD) {
3394  if (CD->isImplicit())
3395  return false;
3396  const FunctionDecl *Definition = CD;
3397  if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) {
3398  HasUndefinedConstructors = true;
3399  return EndOfTU;
3400  }
3401  for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) {
3402  if (hasMatchingNewInCtorInit(CI))
3403  return true;
3404  }
3405  return false;
3406 }
3407 
3408 MismatchingNewDeleteDetector::MismatchResult
3409 MismatchingNewDeleteDetector::analyzeInClassInitializer() {
3410  assert(Field != nullptr && "This should be called only for members");
3411  const Expr *InitExpr = Field->getInClassInitializer();
3412  if (!InitExpr)
3413  return EndOfTU ? NoMismatch : AnalyzeLater;
3414  if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) {
3415  if (NE->isArray() != IsArrayForm) {
3416  NewExprs.push_back(NE);
3417  return MemberInitMismatches;
3418  }
3419  }
3420  return NoMismatch;
3421 }
3422 
3423 MismatchingNewDeleteDetector::MismatchResult
3424 MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field,
3425  bool DeleteWasArrayForm) {
3426  assert(Field != nullptr && "Analysis requires a valid class member.");
3427  this->Field = Field;
3428  IsArrayForm = DeleteWasArrayForm;
3429  const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent());
3430  for (const auto *CD : RD->ctors()) {
3431  if (hasMatchingNewInCtor(CD))
3432  return NoMismatch;
3433  }
3434  if (HasUndefinedConstructors)
3435  return EndOfTU ? NoMismatch : AnalyzeLater;
3436  if (!NewExprs.empty())
3437  return MemberInitMismatches;
3438  return Field->hasInClassInitializer() ? analyzeInClassInitializer()
3439  : NoMismatch;
3440 }
3441 
3442 MismatchingNewDeleteDetector::MismatchResult
3443 MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) {
3444  assert(ME != nullptr && "Expected a member expression");
3445  if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3446  return analyzeField(F, IsArrayForm);
3447  return NoMismatch;
3448 }
3449 
3450 bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) {
3451  const CXXNewExpr *NE = nullptr;
3452  if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) {
3453  if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) &&
3454  NE->isArray() != IsArrayForm) {
3455  NewExprs.push_back(NE);
3456  }
3457  }
3458  return NewExprs.empty();
3459 }
3460 
3461 static void
3463  const MismatchingNewDeleteDetector &Detector) {
3464  SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc);
3465  FixItHint H;
3466  if (!Detector.IsArrayForm)
3467  H = FixItHint::CreateInsertion(EndOfDelete, "[]");
3468  else {
3470  DeleteLoc, tok::l_square, SemaRef.getSourceManager(),
3471  SemaRef.getLangOpts(), true);
3472  if (RSquare.isValid())
3473  H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare));
3474  }
3475  SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new)
3476  << Detector.IsArrayForm << H;
3477 
3478  for (const auto *NE : Detector.NewExprs)
3479  SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here)
3480  << Detector.IsArrayForm;
3481 }
3482 
3483 void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) {
3484  if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation()))
3485  return;
3486  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false);
3487  switch (Detector.analyzeDeleteExpr(DE)) {
3488  case MismatchingNewDeleteDetector::VarInitMismatches:
3489  case MismatchingNewDeleteDetector::MemberInitMismatches: {
3490  DiagnoseMismatchedNewDelete(*this, DE->getBeginLoc(), Detector);
3491  break;
3492  }
3493  case MismatchingNewDeleteDetector::AnalyzeLater: {
3494  DeleteExprs[Detector.Field].push_back(
3495  std::make_pair(DE->getBeginLoc(), DE->isArrayForm()));
3496  break;
3497  }
3498  case MismatchingNewDeleteDetector::NoMismatch:
3499  break;
3500  }
3501 }
3502 
3503 void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
3504  bool DeleteWasArrayForm) {
3505  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true);
3506  switch (Detector.analyzeField(Field, DeleteWasArrayForm)) {
3507  case MismatchingNewDeleteDetector::VarInitMismatches:
3508  llvm_unreachable("This analysis should have been done for class members.");
3509  case MismatchingNewDeleteDetector::AnalyzeLater:
3510  llvm_unreachable("Analysis cannot be postponed any point beyond end of "
3511  "translation unit.");
3512  case MismatchingNewDeleteDetector::MemberInitMismatches:
3513  DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector);
3514  break;
3515  case MismatchingNewDeleteDetector::NoMismatch:
3516  break;
3517  }
3518 }
3519 
3520 /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
3521 /// @code ::delete ptr; @endcode
3522 /// or
3523 /// @code delete [] ptr; @endcode
3524 ExprResult
3525 Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
3526  bool ArrayForm, Expr *ExE) {
3527  // C++ [expr.delete]p1:
3528  // The operand shall have a pointer type, or a class type having a single
3529  // non-explicit conversion function to a pointer type. The result has type
3530  // void.
3531  //
3532  // DR599 amends "pointer type" to "pointer to object type" in both cases.
3533 
3534  ExprResult Ex = ExE;
3535  FunctionDecl *OperatorDelete = nullptr;
3536  bool ArrayFormAsWritten = ArrayForm;
3537  bool UsualArrayDeleteWantsSize = false;
3538 
3539  if (!Ex.get()->isTypeDependent()) {
3540  // Perform lvalue-to-rvalue cast, if needed.
3541  Ex = DefaultLvalueConversion(Ex.get());
3542  if (Ex.isInvalid())
3543  return ExprError();
3544 
3545  QualType Type = Ex.get()->getType();
3546 
3547  class DeleteConverter : public ContextualImplicitConverter {
3548  public:
3549  DeleteConverter() : ContextualImplicitConverter(false, true) {}
3550 
3551  bool match(QualType ConvType) override {
3552  // FIXME: If we have an operator T* and an operator void*, we must pick
3553  // the operator T*.
3554  if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
3555  if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
3556  return true;
3557  return false;
3558  }
3559 
3560  SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
3561  QualType T) override {
3562  return S.Diag(Loc, diag::err_delete_operand) << T;
3563  }
3564 
3565  SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
3566  QualType T) override {
3567  return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
3568  }
3569 
3570  SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
3571  QualType T,
3572  QualType ConvTy) override {
3573  return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
3574  }
3575 
3576  SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
3577  QualType ConvTy) override {
3578  return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3579  << ConvTy;
3580  }
3581 
3582  SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
3583  QualType T) override {
3584  return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
3585  }
3586 
3587  SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
3588  QualType ConvTy) override {
3589  return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3590  << ConvTy;
3591  }
3592 
3593  SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
3594  QualType T,
3595  QualType ConvTy) override {
3596  llvm_unreachable("conversion functions are permitted");
3597  }
3598  } Converter;
3599 
3600  Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
3601  if (Ex.isInvalid())
3602  return ExprError();
3603  Type = Ex.get()->getType();
3604  if (!Converter.match(Type))
3605  // FIXME: PerformContextualImplicitConversion should return ExprError
3606  // itself in this case.
3607  return ExprError();
3608 
3609  QualType Pointee = Type->castAs<PointerType>()->getPointeeType();
3610  QualType PointeeElem = Context.getBaseElementType(Pointee);
3611 
3612  if (Pointee.getAddressSpace() != LangAS::Default &&
3613  !getLangOpts().OpenCLCPlusPlus)
3614  return Diag(Ex.get()->getBeginLoc(),
3615  diag::err_address_space_qualified_delete)
3616  << Pointee.getUnqualifiedType()
3618 
3619  CXXRecordDecl *PointeeRD = nullptr;
3620  if (Pointee->isVoidType() && !isSFINAEContext()) {
3621  // The C++ standard bans deleting a pointer to a non-object type, which
3622  // effectively bans deletion of "void*". However, most compilers support
3623  // this, so we treat it as a warning unless we're in a SFINAE context.
3624  Diag(StartLoc, diag::ext_delete_void_ptr_operand)
3625  << Type << Ex.get()->getSourceRange();
3626  } else if (Pointee->isFunctionType() || Pointee->isVoidType() ||
3627  Pointee->isSizelessType()) {
3628  return ExprError(Diag(StartLoc, diag::err_delete_operand)
3629  << Type << Ex.get()->getSourceRange());
3630  } else if (!Pointee->isDependentType()) {
3631  // FIXME: This can result in errors if the definition was imported from a
3632  // module but is hidden.
3633  if (!RequireCompleteType(StartLoc, Pointee,
3634  diag::warn_delete_incomplete, Ex.get())) {
3635  if (const RecordType *RT = PointeeElem->getAs<RecordType>())
3636  PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
3637  }
3638  }
3639 
3640  if (Pointee->isArrayType() && !ArrayForm) {
3641  Diag(StartLoc, diag::warn_delete_array_type)
3642  << Type << Ex.get()->getSourceRange()
3643  << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]");
3644  ArrayForm = true;
3645  }
3646 
3648  ArrayForm ? OO_Array_Delete : OO_Delete);
3649 
3650  if (PointeeRD) {
3651  if (!UseGlobal &&
3652  FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
3653  OperatorDelete))
3654  return ExprError();
3655 
3656  // If we're allocating an array of records, check whether the
3657  // usual operator delete[] has a size_t parameter.
3658  if (ArrayForm) {
3659  // If the user specifically asked to use the global allocator,
3660  // we'll need to do the lookup into the class.
3661  if (UseGlobal)
3662  UsualArrayDeleteWantsSize =
3663  doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);
3664 
3665  // Otherwise, the usual operator delete[] should be the
3666  // function we just found.
3667  else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
3668  UsualArrayDeleteWantsSize =
3669  UsualDeallocFnInfo(*this,
3670  DeclAccessPair::make(OperatorDelete, AS_public))
3671  .HasSizeT;
3672  }
3673 
3674  if (!PointeeRD->hasIrrelevantDestructor())
3675  if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3676  MarkFunctionReferenced(StartLoc,
3677  const_cast<CXXDestructorDecl*>(Dtor));
3678  if (DiagnoseUseOfDecl(Dtor, StartLoc))
3679  return ExprError();
3680  }
3681 
3682  CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc,
3683  /*IsDelete=*/true, /*CallCanBeVirtual=*/true,
3684  /*WarnOnNonAbstractTypes=*/!ArrayForm,
3685  SourceLocation());
3686  }
3687 
3688  if (!OperatorDelete) {
3689  if (getLangOpts().OpenCLCPlusPlus) {
3690  Diag(StartLoc, diag::err_openclcxx_not_supported) << "default delete";
3691  return ExprError();
3692  }
3693 
3694  bool IsComplete = isCompleteType(StartLoc, Pointee);
3695  bool CanProvideSize =
3696  IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize ||
3697  Pointee.isDestructedType());
3698  bool Overaligned = hasNewExtendedAlignment(*this, Pointee);
3699 
3700  // Look for a global declaration.
3701  OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize,
3702  Overaligned, DeleteName);
3703  }
3704 
3705  MarkFunctionReferenced(StartLoc, OperatorDelete);
3706 
3707  // Check access and ambiguity of destructor if we're going to call it.
3708  // Note that this is required even for a virtual delete.
3709  bool IsVirtualDelete = false;
3710  if (PointeeRD) {
3711  if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3712  CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
3713  PDiag(diag::err_access_dtor) << PointeeElem);
3714  IsVirtualDelete = Dtor->isVirtual();
3715  }
3716  }
3717 
3718  DiagnoseUseOfDecl(OperatorDelete, StartLoc);
3719 
3720  // Convert the operand to the type of the first parameter of operator
3721  // delete. This is only necessary if we selected a destroying operator
3722  // delete that we are going to call (non-virtually); converting to void*
3723  // is trivial and left to AST consumers to handle.
3724  QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
3725  if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) {
3726  Qualifiers Qs = Pointee.getQualifiers();
3727  if (Qs.hasCVRQualifiers()) {
3728  // Qualifiers are irrelevant to this conversion; we're only looking
3729  // for access and ambiguity.
3730  Qs.removeCVRQualifiers();
3731  QualType Unqual = Context.getPointerType(
3733  Ex = ImpCastExprToType(Ex.get(), Unqual, CK_NoOp);
3734  }
3735  Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing);
3736  if (Ex.isInvalid())
3737  return ExprError();
3738  }
3739  }
3740 
3741  CXXDeleteExpr *Result = new (Context) CXXDeleteExpr(
3742  Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
3743  UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
3744  AnalyzeDeleteExprMismatch(Result);
3745  return Result;
3746 }
3747 
3749  bool IsDelete,
3750  FunctionDecl *&Operator) {
3751 
3753  IsDelete ? OO_Delete : OO_New);
3754 
3755  LookupResult R(S, NewName, TheCall->getBeginLoc(), Sema::LookupOrdinaryName);
3757  assert(!R.empty() && "implicitly declared allocation functions not found");
3758  assert(!R.isAmbiguous() && "global allocation functions are ambiguous");
3759 
3760  // We do our own custom access checks below.
3761  R.suppressDiagnostics();
3762 
3763  SmallVector<Expr *, 8> Args(TheCall->arguments());
3764  OverloadCandidateSet Candidates(R.getNameLoc(),
3766  for (LookupResult::iterator FnOvl = R.begin(), FnOvlEnd = R.end();
3767  FnOvl != FnOvlEnd; ++FnOvl) {
3768  // Even member operator new/delete are implicitly treated as
3769  // static, so don't use AddMemberCandidate.
3770  NamedDecl *D = (*FnOvl)->getUnderlyingDecl();
3771 
3772  if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
3773  S.AddTemplateOverloadCandidate(FnTemplate, FnOvl.getPair(),
3774  /*ExplicitTemplateArgs=*/nullptr, Args,
3775  Candidates,
3776  /*SuppressUserConversions=*/false);
3777  continue;
3778  }
3779 
3780  FunctionDecl *Fn = cast<FunctionDecl>(D);
3781  S.AddOverloadCandidate(Fn, FnOvl.getPair(), Args, Candidates,
3782  /*SuppressUserConversions=*/false);
3783  }
3784 
3785  SourceRange Range = TheCall->getSourceRange();
3786 
3787  // Do the resolution.
3789  switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
3790  case OR_Success: {
3791  // Got one!
3792  FunctionDecl *FnDecl = Best->Function;
3793  assert(R.getNamingClass() == nullptr &&
3794  "class members should not be considered");
3795 
3796  if (!FnDecl->isReplaceableGlobalAllocationFunction()) {
3797  S.Diag(R.getNameLoc(), diag::err_builtin_operator_new_delete_not_usual)
3798  << (IsDelete ? 1 : 0) << Range;
3799  S.Diag(FnDecl->getLocation(), diag::note_non_usual_function_declared_here)
3800  << R.getLookupName() << FnDecl->getSourceRange();
3801  return true;
3802  }
3803 
3804  Operator = FnDecl;
3805  return false;
3806  }
3807 
3808  case OR_No_Viable_Function:
3809  Candidates.NoteCandidates(
3811  S.PDiag(diag::err_ovl_no_viable_function_in_call)
3812  << R.getLookupName() << Range),
3813  S, OCD_AllCandidates, Args);
3814  return true;
3815 
3816  case OR_Ambiguous:
3817  Candidates.NoteCandidates(
3819  S.PDiag(diag::err_ovl_ambiguous_call)
3820  << R.getLookupName() << Range),
3821  S, OCD_AmbiguousCandidates, Args);
3822  return true;
3823 
3824  case OR_Deleted: {
3825  Candidates.NoteCandidates(
3826  PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call)
3827  << R.getLookupName() << Range),
3828  S, OCD_AllCandidates, Args);
3829  return true;
3830  }
3831  }
3832  llvm_unreachable("Unreachable, bad result from BestViableFunction");
3833 }
3834 
3835 ExprResult
3836 Sema::SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult,
3837  bool IsDelete) {
3838  CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
3839  if (!getLangOpts().CPlusPlus) {
3840  Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language)
3841  << (IsDelete ? "__builtin_operator_delete" : "__builtin_operator_new")
3842  << "C++";
3843  return ExprError();
3844  }
3845  // CodeGen assumes it can find the global new and delete to call,
3846  // so ensure that they are declared.
3848 
3849  FunctionDecl *OperatorNewOrDelete = nullptr;
3850  if (resolveBuiltinNewDeleteOverload(*this, TheCall, IsDelete,
3851  OperatorNewOrDelete))
3852  return ExprError();
3853  assert(OperatorNewOrDelete && "should be found");
3854 
3855  DiagnoseUseOfDecl(OperatorNewOrDelete, TheCall->getExprLoc());
3856  MarkFunctionReferenced(TheCall->getExprLoc(), OperatorNewOrDelete);
3857 
3858  TheCall->setType(OperatorNewOrDelete->getReturnType());
3859  for (unsigned i = 0; i != TheCall->getNumArgs(); ++i) {
3860  QualType ParamTy = OperatorNewOrDelete->getParamDecl(i)->getType();
3861  InitializedEntity Entity =
3864  Entity, TheCall->getArg(i)->getBeginLoc(), TheCall->getArg(i));
3865  if (Arg.isInvalid())
3866  return ExprError();
3867  TheCall->setArg(i, Arg.get());
3868  }
3869  auto Callee = dyn_cast<ImplicitCastExpr>(TheCall->getCallee());
3870  assert(Callee && Callee->getCastKind() == CK_BuiltinFnToFnPtr &&
3871  "Callee expected to be implicit cast to a builtin function pointer");
3872  Callee->setType(OperatorNewOrDelete->getType());
3873 
3874  return TheCallResult;
3875 }
3876 
3878  bool IsDelete, bool CallCanBeVirtual,
3879  bool WarnOnNonAbstractTypes,
3880  SourceLocation DtorLoc) {
3881  if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext())
3882  return;
3883 
3884  // C++ [expr.delete]p3:
3885  // In the first alternative (delete object), if the static type of the
3886  // object to be deleted is different from its dynamic type, the static
3887  // type shall be a base class of the dynamic type of the object to be
3888  // deleted and the static type shall have a virtual destructor or the
3889  // behavior is undefined.
3890  //
3891  const CXXRecordDecl *PointeeRD = dtor->getParent();
3892  // Note: a final class cannot be derived from, no issue there
3893  if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>())
3894  return;
3895 
3896  // If the superclass is in a system header, there's nothing that can be done.
3897  // The `delete` (where we emit the warning) can be in a system header,
3898  // what matters for this warning is where the deleted type is defined.
3899  if (getSourceManager().isInSystemHeader(PointeeRD->getLocation()))
3900  return;
3901 
3902  QualType ClassType = dtor->getThisType()->getPointeeType();
3903  if (PointeeRD->isAbstract()) {
3904  // If the class is abstract, we warn by default, because we're
3905  // sure the code has undefined behavior.
3906  Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1)
3907  << ClassType;
3908  } else if (WarnOnNonAbstractTypes) {
3909  // Otherwise, if this is not an array delete, it's a bit suspect,
3910  // but not necessarily wrong.
3911  Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1)
3912  << ClassType;
3913  }
3914  if (!IsDelete) {
3915  std::string TypeStr;
3916  ClassType.getAsStringInternal(TypeStr, getPrintingPolicy());
3917  Diag(DtorLoc, diag::note_delete_non_virtual)
3918  << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::");
3919  }
3920 }
3921 
3923  SourceLocation StmtLoc,
3924  ConditionKind CK) {
3925  ExprResult E =
3926  CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK);
3927  if (E.isInvalid())
3928  return ConditionError();
3929  return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc),
3931 }
3932 
3933 /// Check the use of the given variable as a C++ condition in an if,
3934 /// while, do-while, or switch statement.
3936  SourceLocation StmtLoc,
3937  ConditionKind CK) {
3938  if (ConditionVar->isInvalidDecl())
3939  return ExprError();
3940 
3941  QualType T = ConditionVar->getType();
3942 
3943  // C++ [stmt.select]p2:
3944  // The declarator shall not specify a function or an array.
3945  if (T->isFunctionType())
3946  return ExprError(Diag(ConditionVar->getLocation(),
3947  diag::err_invalid_use_of_function_type)
3948  << ConditionVar->getSourceRange());
3949  else if (T->isArrayType())
3950  return ExprError(Diag(ConditionVar->getLocation(),
3951  diag::err_invalid_use_of_array_type)
3952  << ConditionVar->getSourceRange());
3953 
3955  ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue,
3956  ConditionVar->getLocation());
3957 
3958  switch (CK) {
3960  return CheckBooleanCondition(StmtLoc, Condition.get());
3961 
3963  return CheckBooleanCondition(StmtLoc, Condition.get(), true);
3964 
3965  case ConditionKind::Switch:
3966  return CheckSwitchCondition(StmtLoc, Condition.get());
3967  }
3968 
3969  llvm_unreachable("unexpected condition kind");
3970 }
3971 
3972 /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
3973 ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) {
3974  // C++11 6.4p4:
3975  // The value of a condition that is an initialized declaration in a statement
3976  // other than a switch statement is the value of the declared variable
3977  // implicitly converted to type bool. If that conversion is ill-formed, the
3978  // program is ill-formed.
3979  // The value of a condition that is an expression is the value of the
3980  // expression, implicitly converted to bool.
3981  //
3982  // C++2b 8.5.2p2
3983  // If the if statement is of the form if constexpr, the value of the condition
3984  // is contextually converted to bool and the converted expression shall be
3985  // a constant expression.
3986  //
3987 
3989  if (!IsConstexpr || E.isInvalid() || E.get()->isValueDependent())
3990  return E;
3991 
3992  // FIXME: Return this value to the caller so they don't need to recompute it.
3993  llvm::APSInt Cond;
3995  E.get(), &Cond,
3996  diag::err_constexpr_if_condition_expression_is_not_constant);
3997  return E;
3998 }
3999 
4000 /// Helper function to determine whether this is the (deprecated) C++
4001 /// conversion from a string literal to a pointer to non-const char or
4002 /// non-const wchar_t (for narrow and wide string literals,
4003 /// respectively).
4004 bool
4006  // Look inside the implicit cast, if it exists.
4007  if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
4008  From = Cast->getSubExpr();
4009 
4010  // A string literal (2.13.4) that is not a wide string literal can
4011  // be converted to an rvalue of type "pointer to char"; a wide
4012  // string literal can be converted to an rvalue of type "pointer
4013  // to wchar_t" (C++ 4.2p2).
4014  if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
4015  if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
4016  if (const BuiltinType *ToPointeeType
4017  = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
4018  // This conversion is considered only when there is an
4019  // explicit appropriate pointer target type (C++ 4.2p2).
4020  if (!ToPtrType->getPointeeType().hasQualifiers()) {
4021  switch (StrLit->getKind()) {
4022  case StringLiteral::UTF8:
4023  case StringLiteral::UTF16:
4024  case StringLiteral::UTF32:
4025  // We don't allow UTF literals to be implicitly converted
4026  break;
4028  return (ToPointeeType->getKind() == BuiltinType::Char_U ||
4029  ToPointeeType->getKind() == BuiltinType::Char_S);
4030  case StringLiteral::Wide:
4032  QualType(ToPointeeType, 0));
4033  }
4034  }
4035  }
4036 
4037  return false;
4038 }
4039 
4041  SourceLocation CastLoc,
4042  QualType Ty,
4043  CastKind Kind,
4044  CXXMethodDecl *Method,
4045  DeclAccessPair FoundDecl,
4046  bool HadMultipleCandidates,
4047  Expr *From) {
4048  switch (Kind) {
4049  default: llvm_unreachable("Unhandled cast kind!");
4050  case CK_ConstructorConversion: {
4051  CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
4052  SmallVector<Expr*, 8> ConstructorArgs;
4053 
4054  if (S.RequireNonAbstractType(CastLoc, Ty,
4055  diag::err_allocation_of_abstract_type))
4056  return ExprError();
4057 
4058  if (S.CompleteConstructorCall(Constructor, Ty, From, CastLoc,
4059  ConstructorArgs))
4060  return ExprError();
4061 
4062  S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl,
4064  if (S.DiagnoseUseOfDecl(Method, CastLoc))
4065  return ExprError();
4066 
4067  ExprResult Result = S.BuildCXXConstructExpr(
4068  CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method),
4069  ConstructorArgs, HadMultipleCandidates,
4070  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4072  if (Result.isInvalid())
4073  return ExprError();
4074 
4075  return S.MaybeBindToTemporary(Result.getAs<Expr>());
4076  }
4077 
4078  case CK_UserDefinedConversion: {
4079  assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");
4080 
4081  S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
4082  if (S.DiagnoseUseOfDecl(Method, CastLoc))
4083  return ExprError();
4084 
4085  // Create an implicit call expr that calls it.
4086  CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
4087  ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
4088  HadMultipleCandidates);
4089  if (Result.isInvalid())
4090  return ExprError();
4091  // Record usage of conversion in an implicit cast.
4092  Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
4093  CK_UserDefinedConversion, Result.get(),
4094  nullptr, Result.get()->getValueKind(),
4095  S.CurFPFeatureOverrides());
4096 
4097  return S.MaybeBindToTemporary(Result.get());
4098  }
4099  }
4100 }
4101 
4102 /// PerformImplicitConversion - Perform an implicit conversion of the
4103 /// expression From to the type ToType using the pre-computed implicit
4104 /// conversion sequence ICS. Returns the converted
4105 /// expression. Action is the kind of conversion we're performing,
4106 /// used in the error message.
4107 ExprResult
4109  const ImplicitConversionSequence &ICS,
4110  AssignmentAction Action,
4111  CheckedConversionKind CCK) {
4112  // C++ [over.match.oper]p7: [...] operands of class type are converted [...]
4113  if (CCK == CCK_ForBuiltinOverloadedOp && !From->getType()->isRecordType())
4114  return From;
4115 
4116  switch (ICS.getKind()) {
4118  ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
4119  Action, CCK);
4120  if (Res.isInvalid())
4121  return ExprError();
4122  From = Res.get();
4123  break;
4124  }
4125 
4127 
4130  QualType BeforeToType;
4131  assert(FD && "no conversion function for user-defined conversion seq");
4132  if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
4133  CastKind = CK_UserDefinedConversion;
4134 
4135  // If the user-defined conversion is specified by a conversion function,
4136  // the initial standard conversion sequence converts the source type to
4137  // the implicit object parameter of the conversion function.
4138  BeforeToType = Context.getTagDeclType(Conv->getParent());
4139  } else {
4140  const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
4141  CastKind = CK_ConstructorConversion;
4142  // Do no conversion if dealing with ... for the first conversion.
4143  if (!ICS.UserDefined.EllipsisConversion) {
4144  // If the user-defined conversion is specified by a constructor, the
4145  // initial standard conversion sequence converts the source type to
4146  // the type required by the argument of the constructor
4147  BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
4148  }
4149  }
4150  // Watch out for ellipsis conversion.
4151  if (!ICS.UserDefined.EllipsisConversion) {
4152  ExprResult Res =
4153  PerformImplicitConversion(From, BeforeToType,
4155  CCK);
4156  if (Res.isInvalid())
4157  return ExprError();
4158  From = Res.get();
4159  }
4160 
4161  ExprResult CastArg = BuildCXXCastArgument(
4162  *this, From->getBeginLoc(), ToType.getNonReferenceType(), CastKind,
4163  cast<CXXMethodDecl>(FD), ICS.UserDefined.FoundConversionFunction,
4165 
4166  if (CastArg.isInvalid())
4167  return ExprError();
4168 
4169  From = CastArg.get();
4170 
4171  // C++ [over.match.oper]p7:
4172  // [...] the second standard conversion sequence of a user-defined
4173  // conversion sequence is not applied.
4174  if (CCK == CCK_ForBuiltinOverloadedOp)
4175  return From;
4176 
4177  return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
4178  AA_Converting, CCK);
4179  }
4180 
4182  ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
4183  PDiag(diag::err_typecheck_ambiguous_condition)
4184  << From->getSourceRange());
4185  return ExprError();
4186 
4189  llvm_unreachable("bad conversion");
4190 
4192  Sema::AssignConvertType ConvTy =
4193  CheckAssignmentConstraints(From->getExprLoc(), ToType, From->getType());
4194  bool Diagnosed = DiagnoseAssignmentResult(
4195  ConvTy == Compatible ? Incompatible : ConvTy, From->getExprLoc(),
4196  ToType, From->getType(), From, Action);
4197  assert(Diagnosed && "failed to diagnose bad conversion"); (void)Diagnosed;
4198  return ExprError();
4199  }
4200 
4201  // Everything went well.
4202  return From;
4203 }
4204 
4205 /// PerformImplicitConversion - Perform an implicit conversion of the
4206 /// expression From to the type ToType by following the standard
4207 /// conversion sequence SCS. Returns the converted
4208 /// expression. Flavor is the context in which we're performing this
4209 /// conversion, for use in error messages.
4210 ExprResult
4212  const StandardConversionSequence& SCS,
4213  AssignmentAction Action,
4214  CheckedConversionKind CCK) {
4215  bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);
4216 
4217  // Overall FIXME: we are recomputing too many types here and doing far too
4218  // much extra work. What this means is that we need to keep track of more
4219  // information that is computed when we try the implicit conversion initially,
4220  // so that we don't need to recompute anything here.
4221  QualType FromType = From->getType();
4222 
4223  if (SCS.CopyConstructor) {
4224  // FIXME: When can ToType be a reference type?
4225  assert(!ToType->isReferenceType());
4226  if (SCS.Second == ICK_Derived_To_Base) {
4227  SmallVector<Expr*, 8> ConstructorArgs;
4229  cast<CXXConstructorDecl>(SCS.CopyConstructor), ToType, From,
4230  /*FIXME:ConstructLoc*/ SourceLocation(), ConstructorArgs))
4231  return ExprError();
4232  return BuildCXXConstructExpr(
4233  /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
4235  ConstructorArgs, /*HadMultipleCandidates*/ false,
4236  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4238  }
4239  return BuildCXXConstructExpr(
4240  /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
4242  From, /*HadMultipleCandidates*/ false,
4243  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
4245  }
4246 
4247  // Resolve overloaded function references.
4248  if (Context.hasSameType(FromType, Context.OverloadTy)) {
4249  DeclAccessPair Found;
4251  true, Found);
4252  if (!Fn)
4253  return ExprError();
4254 
4255  if (DiagnoseUseOfDecl(Fn, From->getBeginLoc()))
4256  return ExprError();
4257 
4258  From = FixOverloadedFunctionReference(From, Found, Fn);
4259 
4260  // We might get back another placeholder expression if we resolved to a
4261  // builtin.
4262  ExprResult Checked = CheckPlaceholderExpr(From);
4263  if (Checked.isInvalid())
4264  return ExprError();
4265 
4266  From = Checked.get();
4267  FromType = From->getType();
4268  }
4269 
4270  // If we're converting to an atomic type, first convert to the corresponding
4271  // non-atomic type.
4272  QualType ToAtomicType;
4273  if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
4274  ToAtomicType = ToType;
4275  ToType = ToAtomic->getValueType();
4276  }
4277 
4278  QualType InitialFromType = FromType;
4279  // Perform the first implicit conversion.
4280  switch (SCS.First) {
4281  case ICK_Identity:
4282  if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
4283  FromType = FromAtomic->getValueType().getUnqualifiedType();
4284  From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
4285  From, /*BasePath=*/nullptr, VK_PRValue,
4286  FPOptionsOverride());
4287  }
4288  break;
4289 
4290  case ICK_Lvalue_To_Rvalue: {
4291  assert(From->getObjectKind() != OK_ObjCProperty);
4292  ExprResult FromRes = DefaultLvalueConversion(From);
4293  if (FromRes.isInvalid())
4294  return ExprError();
4295 
4296  From = FromRes.get();
4297  FromType = From->getType();
4298  break;
4299  }
4300 
4301  case ICK_Array_To_Pointer:
4302  FromType = Context.getArrayDecayedType(FromType);
4303  From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, VK_PRValue,
4304  /*BasePath=*/nullptr, CCK)
4305  .get();
4306  break;
4307 
4309  FromType = Context.getPointerType(FromType);
4310  From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
4311  VK_PRValue, /*BasePath=*/nullptr, CCK)
4312  .get();
4313  break;
4314 
4315  default:
4316  llvm_unreachable("Improper first standard conversion");
4317  }
4318 
4319  // Perform the second implicit conversion
4320  switch (SCS.Second) {
4321  case ICK_Identity:
4322  // C++ [except.spec]p5:
4323  // [For] assignment to and initialization of pointers to functions,
4324  // pointers to member functions, and references to functions: the
4325  // target entity shall allow at least the exceptions allowed by the
4326  // source value in the assignment or initialization.
4327  switch (Action) {
4328  case AA_Assigning:
4329  case AA_Initializing:
4330  // Note, function argument passing and returning are initialization.
4331  case AA_Passing:
4332  case AA_Returning:
4333  case AA_Sending:
4334  case AA_Passing_CFAudited:
4335  if (CheckExceptionSpecCompatibility(From, ToType))
4336  return ExprError();
4337  break;
4338 
4339  case AA_Casting:
4340  case AA_Converting:
4341  // Casts and implicit conversions are not initialization, so are not
4342  // checked for exception specification mismatches.
4343  break;
4344  }
4345  // Nothing else to do.
4346  break;
4347 
4350  if (ToType->isBooleanType()) {
4351  assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
4352  SCS.Second == ICK_Integral_Promotion &&
4353  "only enums with fixed underlying type can promote to bool");
4354  From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, VK_PRValue,
4355  /*BasePath=*/nullptr, CCK)
4356  .get();
4357  } else {
4358  From = ImpCastExprToType(From, ToType, CK_IntegralCast, VK_PRValue,
4359  /*BasePath=*/nullptr, CCK)
4360  .get();
4361  }
4362  break;
4363 
4366  From = ImpCastExprToType(From, ToType, CK_FloatingCast, VK_PRValue,
4367  /*BasePath=*/nullptr, CCK)
4368  .get();
4369  break;
4370 
4371  case ICK_Complex_Promotion:
4372  case ICK_Complex_Conversion: {
4373  QualType FromEl = From->getType()->castAs<ComplexType>()->getElementType();
4374  QualType ToEl = ToType->castAs<ComplexType>()->getElementType();
4375  CastKind CK;
4376  if (FromEl->isRealFloatingType()) {
4377  if (ToEl->isRealFloatingType())
4378  CK = CK_FloatingComplexCast;
4379  else
4380  CK = CK_FloatingComplexToIntegralComplex;
4381  } else if (ToEl->isRealFloatingType()) {
4382  CK = CK_IntegralComplexToFloatingComplex;
4383  } else {
4384  CK = CK_IntegralComplexCast;
4385  }
4386  From = ImpCastExprToType(From, ToType, CK, VK_PRValue, /*BasePath=*/nullptr,
4387  CCK)
4388  .get();
4389  break;
4390  }
4391 
4392  case ICK_Floating_Integral:
4393  if (ToType->isRealFloatingType())
4394  From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, VK_PRValue,
4395  /*BasePath=*/nullptr, CCK)
4396  .get();
4397  else
4398  From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, VK_PRValue,
4399  /*BasePath=*/nullptr, CCK)
4400  .get();
4401  break;
4402 
4404  From = ImpCastExprToType(From, ToType, CK_NoOp, From->getValueKind(),
4405  /*BasePath=*/nullptr, CCK).get();
4406  break;
4407 
4409  case ICK_Pointer_Conversion: {
4410  if (SCS.IncompatibleObjC && Action != AA_Casting) {
4411  // Diagnose incompatible Objective-C conversions
4412  if (Action == AA_Initializing || Action == AA_Assigning)
4413  Diag(From->getBeginLoc(),
4414  diag::ext_typecheck_convert_incompatible_pointer)
4415  << ToType << From->getType() << Action << From->getSourceRange()
4416  << 0;
4417  else
4418  Diag(From->getBeginLoc(),
4419  diag::ext_typecheck_convert_incompatible_pointer)
4420  << From->getType() << ToType << Action << From->getSourceRange()
4421  << 0;
4422 
4423  if (From->getType()->isObjCObjectPointerType() &&
4424  ToType->isObjCObjectPointerType())
4426  } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() &&
4428  From->getType())) {
4429  if (Action == AA_Initializing)
4430  Diag(From->getBeginLoc(), diag::err_arc_weak_unavailable_assign);
4431  else
4432  Diag(From->getBeginLoc(), diag::err_arc_convesion_of_weak_unavailable)
4433  << (Action == AA_Casting) << From->getType() << ToType
4434  << From->getSourceRange();
4435  }
4436 
4437  // Defer address space conversion to the third conversion.
4438  QualType FromPteeType = From->getType()->getPointeeType();
4439  QualType ToPteeType = ToType->getPointeeType();
4440  QualType NewToType = ToType;
4441  if (!FromPteeType.isNull() && !ToPteeType.isNull() &&
4442  FromPteeType.getAddressSpace() != ToPteeType.getAddressSpace()) {
4443  NewToType = Context.removeAddrSpaceQualType(ToPteeType);
4444  NewToType = Context.getAddrSpaceQualType(NewToType,
4445  FromPteeType.getAddressSpace());
4446  if (ToType->isObjCObjectPointerType())
4447  NewToType = Context.getObjCObjectPointerType(NewToType);
4448  else if (ToType->isBlockPointerType())
4449  NewToType = Context.getBlockPointerType(NewToType);
4450  else
4451  NewToType = Context.getPointerType(NewToType);
4452  }
4453 
4454  CastKind Kind;
4455  CXXCastPath BasePath;
4456  if (CheckPointerConversion(From, NewToType, Kind, BasePath, CStyle))
4457  return ExprError();
4458 
4459  // Make sure we extend blocks if necessary.
4460  // FIXME: doing this here is really ugly.
4461  if (Kind == CK_BlockPointerToObjCPointerCast) {
4462  ExprResult E = From;
4464  From = E.get();
4465  }
4467  CheckObjCConversion(SourceRange(), NewToType, From, CCK);
4468  From = ImpCastExprToType(From, NewToType, Kind, VK_PRValue, &BasePath, CCK)
4469  .get();
4470  break;
4471  }
4472 
4473  case ICK_Pointer_Member: {
4474  CastKind Kind;
4475  CXXCastPath BasePath;
4476  if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
4477  return ExprError();
4478  if (CheckExceptionSpecCompatibility(From, ToType))
4479  return ExprError();
4480 
4481  // We may not have been able to figure out what this member pointer resolved
4482  // to up until this exact point. Attempt to lock-in it's inheritance model.
4484  (void)isCompleteType(From->getExprLoc(), From->getType());
4485  (void)isCompleteType(From->getExprLoc(), ToType);
4486  }
4487 
4488  From =
4489  ImpCastExprToType(From, ToType, Kind, VK_PRValue, &BasePath, CCK).get();
4490  break;
4491  }
4492 
4494  // Perform half-to-boolean conversion via float.
4495  if (From->getType()->isHalfType()) {
4496  From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
4497  FromType = Context.FloatTy;
4498  }
4499 
4500  From = ImpCastExprToType(From, Context.BoolTy,
4502  /*BasePath=*/nullptr, CCK)
4503  .get();
4504  break;
4505 
4506  case ICK_Derived_To_Base: {
4507  CXXCastPath BasePath;
4509  From->getType(), ToType.getNonReferenceType(), From->getBeginLoc(),
4510  From->getSourceRange(), &BasePath, CStyle))
4511  return ExprError();
4512 
4513  From = ImpCastExprToType(From, ToType.getNonReferenceType(),
4514  CK_DerivedToBase, From->getValueKind(),
4515  &BasePath, CCK).get();
4516  break;
4517  }
4518 
4519  case ICK_Vector_Conversion:
4520  From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
4521  /*BasePath=*/nullptr, CCK)
4522  .get();
4523  break;
4524 
4526  From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue,
4527  /*BasePath=*/nullptr, CCK)
4528  .get();
4529  break;
4530 
4531  case ICK_Vector_Splat: {
4532  // Vector splat from any arithmetic type to a vector.
4533  Expr *Elem = prepareVectorSplat(ToType, From).get();
4534  From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_PRValue,
4535  /*BasePath=*/nullptr, CCK)
4536  .get();
4537  break;
4538  }
4539 
4540  case ICK_Complex_Real:
4541  // Case 1. x -> _Complex y
4542  if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
4543  QualType ElType = ToComplex->getElementType();
4544  bool isFloatingComplex = ElType->isRealFloatingType();
4545 
4546  // x -> y
4547  if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
4548  // do nothing
4549  } else if (From->getType()->isRealFloatingType()) {
4550  From = ImpCastExprToType(From, ElType,
4551  isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
4552  } else {
4553  assert(From->getType()->isIntegerType());
4554  From = ImpCastExprToType(From, ElType,
4555  isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
4556  }
4557  // y -> _Complex y
4558  From = ImpCastExprToType(From, ToType,
4559  isFloatingComplex ? CK_FloatingRealToComplex
4560  : CK_IntegralRealToComplex).get();
4561 
4562  // Case 2. _Complex x -> y
4563  } else {
4564  auto *FromComplex = From->getType()->castAs<ComplexType>();
4565  QualType ElType = FromComplex->getElementType();
4566  bool isFloatingComplex = ElType->isRealFloatingType();
4567 
4568  // _Complex x -> x
4569  From = ImpCastExprToType(From, ElType,
4570  isFloatingComplex ? CK_FloatingComplexToReal
4571  : CK_IntegralComplexToReal,
4572  VK_PRValue, /*BasePath=*/nullptr, CCK)
4573  .get();
4574 
4575  // x -> y
4576  if (Context.hasSameUnqualifiedType(ElType, ToType)) {
4577  // do nothing
4578  } else if (ToType->isRealFloatingType()) {
4579  From = ImpCastExprToType(From, ToType,
4580  isFloatingComplex ? CK_FloatingCast
4581  : CK_IntegralToFloating,
4582  VK_PRValue, /*BasePath=*/nullptr, CCK)
4583  .get();
4584  } else {
4585  assert(ToType->isIntegerType());
4586  From = ImpCastExprToType(From, ToType,
4587  isFloatingComplex ? CK_FloatingToIntegral
4588  : CK_IntegralCast,
4589  VK_PRValue, /*BasePath=*/nullptr, CCK)
4590  .get();
4591  }
4592  }
4593  break;
4594 
4596  LangAS AddrSpaceL =
4597  ToType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
4598  LangAS AddrSpaceR =
4599  FromType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace();
4600  assert(Qualifiers::isAddressSpaceSupersetOf(AddrSpaceL, AddrSpaceR) &&
4601  "Invalid cast");
4602  CastKind Kind =
4603  AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast;
4604  From = ImpCastExprToType(From, ToType.getUnqualifiedType(), Kind,
4605  VK_PRValue, /*BasePath=*/nullptr, CCK)
4606  .get();
4607  break;
4608  }
4609 
4611  ExprResult FromRes = From;
4612  Sema::AssignConvertType ConvTy =
4614  if (FromRes.isInvalid())
4615  return ExprError();
4616  From = FromRes.get();
4617  assert ((ConvTy == Sema::Compatible) &&
4618  "Improper transparent union conversion");
4619  (void)ConvTy;
4620  break;
4621  }
4622 
4625  From = ImpCastExprToType(From, ToType,
4626  CK_ZeroToOCLOpaqueType,
4627  From->getValueKind()).get();
4628  break;
4629 
4630  case ICK_Lvalue_To_Rvalue:
4631  case ICK_Array_To_Pointer:
4634  case ICK_Qualification:
4636  case ICK_C_Only_Conversion:
4638  llvm_unreachable("Improper second standard conversion");
4639  }
4640 
4641  switch (SCS.Third) {
4642  case ICK_Identity:
4643  // Nothing to do.
4644  break;
4645 
4647  // If both sides are functions (or pointers/references to them), there could
4648  // be incompatible exception declarations.
4649  if (CheckExceptionSpecCompatibility(From, ToType))
4650  return ExprError();
4651 
4652  From = ImpCastExprToType(From, ToType, CK_NoOp, VK_PRValue,
4653  /*BasePath=*/nullptr, CCK)
4654  .get();
4655  break;
4656 
4657  case ICK_Qualification: {
4658  ExprValueKind VK = From->getValueKind();
4659  CastKind CK = CK_NoOp;
4660 
4661  if (ToType->isReferenceType() &&
4662  ToType->getPointeeType().getAddressSpace() !=
4663  From->getType().getAddressSpace())
4664  CK = CK_AddressSpaceConversion;
4665 
4666  if (ToType->isPointerType() &&
4667  ToType->getPointeeType().getAddressSpace() !=
4668  From->getType()->getPointeeType().getAddressSpace())
4669  CK = CK_AddressSpaceConversion;
4670 
4671  if (!isCast(CCK) &&
4672  !ToType->getPointeeType().getQualifiers().hasUnaligned() &&
4674  Diag(From->getBeginLoc(), diag::warn_imp_cast_drops_unaligned)
4675  << InitialFromType << ToType;
4676  }
4677 
4678  From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK, VK,
4679  /*BasePath=*/nullptr, CCK)
4680  .get();
4681 
4683  !getLangOpts().WritableStrings) {
4684  Diag(From->getBeginLoc(),
4686  ? diag::ext_deprecated_string_literal_conversion
4687  : diag::warn_deprecated_string_literal_conversion)
4688  << ToType.getNonReferenceType();
4689  }
4690 
4691  break;
4692  }
4693 
4694  default:
4695  llvm_unreachable("Improper third standard conversion");
4696  }
4697 
4698  // If this conversion sequence involved a scalar -> atomic conversion, perform
4699  // that conversion now.
4700  if (!ToAtomicType.isNull()) {
4701  assert(Context.hasSameType(
4702  ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()));
4703  From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic,
4704  VK_PRValue, nullptr, CCK)
4705  .get();
4706  }
4707 
4708  // Materialize a temporary if we're implicitly converting to a reference
4709  // type. This is not required by the C++ rules but is necessary to maintain
4710  // AST invariants.
4711  if (ToType->isReferenceType() && From->isPRValue()) {
4713  if (Res.isInvalid())
4714  return ExprError();
4715  From = Res.get();
4716  }
4717 
4718  // If this conversion sequence succeeded and involved implicitly converting a
4719  // _Nullable type to a _Nonnull one, complain.
4720  if (!isCast(CCK))
4721  diagnoseNullableToNonnullConversion(ToType, InitialFromType,
4722  From->getBeginLoc());
4723 
4724  return From;
4725 }
4726 
4727 /// Check the completeness of a type in a unary type trait.
4728 ///
4729 /// If the particular type trait requires a complete type, tries to complete
4730 /// it. If completing the type fails, a diagnostic is emitted and false
4731 /// returned. If completing the type succeeds or no completion was required,
4732 /// returns true.
4734  SourceLocation Loc,
4735  QualType ArgTy) {
4736  // C++0x [meta.unary.prop]p3:
4737  // For all of the class templates X declared in this Clause, instantiating
4738  // that template with a template argument that is a class template
4739  // specialization may result in the implicit instantiation of the template
4740  // argument if and only if the semantics of X require that the argument
4741  // must be a complete type.
4742  // We apply this rule to all the type trait expressions used to implement
4743  // these class templates. We also try to follow any GCC documented behavior
4744  // in these expressions to ensure portability of standard libraries.
4745  switch (UTT) {
4746  default: llvm_unreachable("not a UTT");
4747  // is_complete_type somewhat obviously cannot require a complete type.
4748  case UTT_IsCompleteType:
4749  // Fall-through
4750 
4751  // These traits are modeled on the type predicates in C++0x
4752  // [meta.unary.cat] and [meta.unary.comp]. They are not specified as
4753  // requiring a complete type, as whether or not they return true cannot be
4754  // impacted by the completeness of the type.
4755  case UTT_IsVoid:
4756  case UTT_IsIntegral:
4757  case UTT_IsFloatingPoint:
4758  case UTT_IsArray:
4759  case UTT_IsPointer:
4760  case UTT_IsLvalueReference:
4761  case UTT_IsRvalueReference:
4762  case UTT_IsMemberFunctionPointer:
4763  case UTT_IsMemberObjectPointer:
4764  case UTT_IsEnum:
4765  case UTT_IsUnion:
4766  case UTT_IsClass:
4767  case UTT_IsFunction:
4768  case UTT_IsReference:
4769  case UTT_IsArithmetic:
4770  case UTT_IsFundamental:
4771  case UTT_IsObject:
4772  case UTT_IsScalar:
4773  case UTT_IsCompound:
4774  case UTT_IsMemberPointer:
4775  // Fall-through
4776 
4777  // These traits are modeled on type predicates in C++0x [meta.unary.prop]
4778  // which requires some of its traits to have the complete type. However,
4779  // the completeness of the type cannot impact these traits' semantics, and
4780  // so they don't require it. This matches the comments on these traits in
4781  // Table 49.
4782  case UTT_IsConst:
4783  case UTT_IsVolatile:
4784  case UTT_IsSigned:
4785  case UTT_IsUnsigned:
4786 
4787  // This type trait always returns false, checking the type is moot.
4788  case UTT_IsInterfaceClass:
4789  return true;
4790 
4791  // C++14 [meta.unary.prop]:
4792  // If T is a non-union class type, T shall be a complete type.
4793  case UTT_IsEmpty:
4794  case UTT_IsPolymorphic:
4795  case UTT_IsAbstract:
4796  if (const auto *RD = ArgTy->getAsCXXRecordDecl())
4797  if (!RD->isUnion())
4798  return !S.RequireCompleteType(
4799  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4800  return true;
4801 
4802  // C++14 [meta.unary.prop]:
4803  // If T is a class type, T shall be a complete type.
4804  case UTT_IsFinal:
4805  case UTT_IsSealed:
4806  if (ArgTy->getAsCXXRecordDecl())
4807  return !S.RequireCompleteType(
4808  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4809  return true;
4810 
4811  // C++1z [meta.unary.prop]:
4812  // remove_all_extents_t<T> shall be a complete type or cv void.
4813  case UTT_IsAggregate:
4814  case UTT_IsTrivial:
4815  case UTT_IsTriviallyCopyable:
4816  case UTT_IsStandardLayout:
4817  case UTT_IsPOD:
4818  case UTT_IsLiteral:
4819  // By analogy, is_trivially_relocatable imposes the same constraints.
4820  case UTT_IsTriviallyRelocatable:
4821  // Per the GCC type traits documentation, T shall be a complete type, cv void,
4822  // or an array of unknown bound. But GCC actually imposes the same constraints
4823  // as above.
4824  case UTT_HasNothrowAssign:
4825  case UTT_HasNothrowMoveAssign:
4826  case UTT_HasNothrowConstructor:
4827  case UTT_HasNothrowCopy:
4828  case UTT_HasTrivialAssign:
4829  case UTT_HasTrivialMoveAssign:
4830  case UTT_HasTrivialDefaultConstructor:
4831  case UTT_HasTrivialMoveConstructor:
4832  case UTT_HasTrivialCopy:
4833  case UTT_HasTrivialDestructor:
4834  case UTT_HasVirtualDestructor:
4835  ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0);
4836  [[fallthrough]];
4837 
4838  // C++1z [meta.unary.prop]:
4839  // T shall be a complete type, cv void, or an array of unknown bound.
4840  case UTT_IsDestructible:
4841  case UTT_IsNothrowDestructible:
4842  case UTT_IsTriviallyDestructible:
4843  case UTT_HasUniqueObjectRepresentations:
4844  if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType())
4845  return true;
4846 
4847  return !S.RequireCompleteType(
4848  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4849  }
4850 }
4851 
4853  Sema &Self, SourceLocation KeyLoc, ASTContext &C,
4854  bool (CXXRecordDecl::*HasTrivial)() const,
4855  bool (CXXRecordDecl::*HasNonTrivial)() const,
4856  bool (CXXMethodDecl::*IsDesiredOp)() const)
4857 {
4858  CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
4859  if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)())
4860  return true;
4861 
4862  DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op);
4863  DeclarationNameInfo NameInfo(Name, KeyLoc);
4864  LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName);
4865  if (Self.LookupQualifiedName(Res, RD)) {
4866  bool FoundOperator = false;
4867  Res.suppressDiagnostics();
4868  for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end();
4869  Op != OpEnd; ++Op) {
4870  if (isa<FunctionTemplateDecl>(*Op))
4871  continue;
4872 
4873  CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op);
4874  if((Operator->*IsDesiredOp)()) {
4875  FoundOperator = true;
4876  auto *CPT = Operator->getType()->castAs<FunctionProtoType>();
4877  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
4878  if (!CPT || !CPT->isNothrow())
4879  return false;
4880  }
4881  }
4882  return FoundOperator;
4883  }
4884  return false;
4885 }
4886 
4887 static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
4888  SourceLocation KeyLoc, QualType T) {
4889  assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
4890 
4891  ASTContext &C = Self.Context;
4892  switch(UTT) {
4893  default: llvm_unreachable("not a UTT");
4894  // Type trait expressions corresponding to the primary type category
4895  // predicates in C++0x [meta.unary.cat].
4896  case UTT_IsVoid:
4897  return T->isVoidType();
4898  case UTT_IsIntegral:
4899  return T->isIntegralType(C);
4900  case UTT_IsFloatingPoint:
4901  return T->isFloatingType();
4902  case UTT_IsArray:
4903  return T->isArrayType();
4904  case UTT_IsPointer:
4905  return T->isAnyPointerType();
4906  case UTT_IsLvalueReference:
4907  return T->isLValueReferenceType();
4908  case UTT_IsRvalueReference:
4909  return T->isRValueReferenceType();
4910  case UTT_IsMemberFunctionPointer:
4911  return T->isMemberFunctionPointerType();
4912  case UTT_IsMemberObjectPointer:
4913  return T->isMemberDataPointerType();
4914  case UTT_IsEnum:
4915  return T->isEnumeralType();
4916  case UTT_IsUnion:
4917  return T->isUnionType();
4918  case UTT_IsClass:
4919  return T->isClassType() || T->isStructureType() || T->isInterfaceType();
4920  case UTT_IsFunction:
4921  return T->isFunctionType();
4922 
4923  // Type trait expressions which correspond to the convenient composition
4924  // predicates in C++0x [meta.unary.comp].
4925  case UTT_IsReference:
4926  return T->isReferenceType();
4927  case UTT_IsArithmetic:
4928  return T->isArithmeticType() && !T->isEnumeralType();
4929  case UTT_IsFundamental:
4930  return T->isFundamentalType();
4931  case UTT_IsObject:
4932  return T->isObjectType();
4933  case UTT_IsScalar:
4934  // Note: semantic analysis depends on Objective-C lifetime types to be
4935  // considered scalar types. However, such types do not actually behave
4936  // like scalar types at run time (since they may require retain/release
4937  // operations), so we report them as non-scalar.
4938  if (T->isObjCLifetimeType()) {
4939  switch (T.getObjCLifetime()) {
4940  case Qualifiers::OCL_None:
4942  return true;
4943 
4945  case Qualifiers::OCL_Weak:
4947  return false;
4948  }
4949  }
4950 
4951  return T->isScalarType();
4952  case UTT_IsCompound:
4953  return T->isCompoundType();
4954  case UTT_IsMemberPointer:
4955  return T->isMemberPointerType();
4956 
4957  // Type trait expressions which correspond to the type property predicates
4958  // in C++0x [meta.unary.prop].
4959  case UTT_IsConst:
4960  return T.isConstQualified();
4961  case UTT_IsVolatile:
4962  return T.isVolatileQualified();
4963  case UTT_IsTrivial:
4964  return T.isTrivialType(C);
4965  case UTT_IsTriviallyCopyable:
4966  return T.isTriviallyCopyableType(C);
4967  case UTT_IsStandardLayout:
4968  return T->isStandardLayoutType();
4969  case UTT_IsPOD:
4970  return T.isPODType(C);
4971  case UTT_IsLiteral:
4972  return T->isLiteralType(C);
4973  case UTT_IsEmpty:
4974  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4975  return !RD->isUnion() && RD->isEmpty();
4976  return false;
4977  case UTT_IsPolymorphic:
4978  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4979  return !RD->isUnion() && RD->isPolymorphic();
4980  return false;
4981  case UTT_IsAbstract:
4982  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4983  return !RD->isUnion() && RD->isAbstract();
4984  return false;
4985  case UTT_IsAggregate:
4986  // Report vector extensions and complex types as aggregates because they
4987  // support aggregate initialization. GCC mirrors this behavior for vectors
4988  // but not _Complex.
4989  return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() ||
4990  T->isAnyComplexType();
4991  // __is_interface_class only returns true when CL is invoked in /CLR mode and
4992  // even then only when it is used with the 'interface struct ...' syntax
4993  // Clang doesn't support /CLR which makes this type trait moot.
4994  case UTT_IsInterfaceClass:
4995  return false;
4996  case UTT_IsFinal:
4997  case UTT_IsSealed:
4998  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4999  return RD->hasAttr<FinalAttr>();
5000  return false;
5001  case UTT_IsSigned:
5002  // Enum types should always return false.
5003  // Floating points should always return true.
5004  return T->isFloatingType() ||
5005  (T->isSignedIntegerType() && !T->isEnumeralType());
5006  case UTT_IsUnsigned:
5007  // Enum types should always return false.
5008  return T->isUnsignedIntegerType() && !T->isEnumeralType();
5009 
5010  // Type trait expressions which query classes regarding their construction,
5011  // destruction, and copying. Rather than being based directly on the
5012  // related type predicates in the standard, they are specified by both
5013  // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those
5014  // specifications.
5015  //
5016  // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html
5017  // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
5018  //
5019  // Note that these builtins do not behave as documented in g++: if a class
5020  // has both a trivial and a non-trivial special member of a particular kind,
5021  // they return false! For now, we emulate this behavior.
5022  // FIXME: This appears to be a g++ bug: more complex cases reveal that it
5023  // does not correctly compute triviality in the presence of multiple special
5024  // members of the same kind. Revisit this once the g++ bug is fixed.
5025  case UTT_HasTrivialDefaultConstructor:
5026  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5027  // If __is_pod (type) is true then the trait is true, else if type is
5028  // a cv class or union type (or array thereof) with a trivial default
5029  // constructor ([class.ctor]) then the trait is true, else it is false.
5030  if (T.isPODType(C))
5031  return true;
5032  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5033  return RD->hasTrivialDefaultConstructor() &&
5035  return false;
5036  case UTT_HasTrivialMoveConstructor:
5037  // This trait is implemented by MSVC 2012 and needed to parse the
5038  // standard library headers. Specifically this is used as the logic
5039  // behind std::is_trivially_move_constructible (20.9.4.3).
5040  if (T.isPODType(C))
5041  return true;
5042  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5044  return false;
5045  case UTT_HasTrivialCopy:
5046  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5047  // If __is_pod (type) is true or type is a reference type then
5048  // the trait is true, else if type is a cv class or union type
5049  // with a trivial copy constructor ([class.copy]) then the trait
5050  // is true, else it is false.
5051  if (T.isPODType(C) || T->isReferenceType())
5052  return true;
5053  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5054  return RD->hasTrivialCopyConstructor() &&
5056  return false;
5057  case UTT_HasTrivialMoveAssign:
5058  // This trait is implemented by MSVC 2012 and needed to parse the
5059  // standard library headers. Specifically it is used as the logic
5060  // behind std::is_trivially_move_assignable (20.9.4.3)
5061  if (T.isPODType(C))
5062  return true;
5063  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5065  return false;
5066  case UTT_HasTrivialAssign:
5067  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5068  // If type is const qualified or is a reference type then the
5069  // trait is false. Otherwise if __is_pod (type) is true then the
5070  // trait is true, else if type is a cv class or union type with
5071  // a trivial copy assignment ([class.copy]) then the trait is
5072  // true, else it is false.
5073  // Note: the const and reference restrictions are interesting,
5074  // given that const and reference members don't prevent a class
5075  // from having a trivial copy assignment operator (but do cause
5076  // errors if the copy assignment operator is actually used, q.v.
5077  // [class.copy]p12).
5078 
5079  if (T.isConstQualified())
5080  return false;
5081  if (T.isPODType(C))
5082  return true;
5083  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5084  return RD->hasTrivialCopyAssignment() &&
5086  return false;
5087  case UTT_IsDestructible:
5088  case UTT_IsTriviallyDestructible:
5089  case UTT_IsNothrowDestructible:
5090  // C++14 [meta.unary.prop]:
5091  // For reference types, is_destructible<T>::value is true.
5092  if (T->isReferenceType())
5093  return true;
5094 
5095  // Objective-C++ ARC: autorelease types don't require destruction.
5096  if (T->isObjCLifetimeType() &&
5098  return true;
5099 
5100  // C++14 [meta.unary.prop]:
5101  // For incomplete types and function types, is_destructible<T>::value is
5102  // false.
5103  if (T->isIncompleteType() || T->isFunctionType())
5104  return false;
5105 
5106  // A type that requires destruction (via a non-trivial destructor or ARC
5107  // lifetime semantics) is not trivially-destructible.
5108  if (UTT == UTT_IsTriviallyDestructible && T.isDestructedType())
5109  return false;
5110 
5111  // C++14 [meta.unary.prop]:
5112  // For object types and given U equal to remove_all_extents_t<T>, if the
5113  // expression std::declval<U&>().~U() is well-formed when treated as an
5114  // unevaluated operand (Clause 5), then is_destructible<T>::value is true
5115  if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
5116  CXXDestructorDecl *Destructor = Self.LookupDestructor(RD);
5117  if (!Destructor)
5118  return false;
5119  // C++14 [dcl.fct.def.delete]p2:
5120  // A program that refers to a deleted function implicitly or
5121  // explicitly, other than to declare it, is ill-formed.
5122  if (Destructor->isDeleted())
5123  return false;
5124  if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public)
5125  return false;
5126  if (UTT == UTT_IsNothrowDestructible) {
5127  auto *CPT = Destructor->getType()->castAs<FunctionProtoType>();
5128  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5129  if (!CPT || !CPT->isNothrow())
5130  return false;
5131  }
5132  }
5133  return true;
5134 
5135  case UTT_HasTrivialDestructor:
5136  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
5137  // If __is_pod (type) is true or type is a reference type
5138  // then the trait is true, else if type is a cv class or union
5139  // type (or array thereof) with a trivial destructor
5140  // ([class.dtor]) then the trait is true, else it is
5141  // false.
5142  if (T.isPODType(C) || T->isReferenceType())
5143  return true;
5144 
5145  // Objective-C++ ARC: autorelease types don't require destruction.
5146  if (T->isObjCLifetimeType() &&
5148  return true;
5149 
5150  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
5151  return RD->hasTrivialDestructor();
5152  return false;
5153  // TODO: Propagate nothrowness for implicitly declared special members.
5154  case UTT_HasNothrowAssign:
5155  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5156  // If type is const qualified or is a reference type then the
5157  // trait is false. Otherwise if __has_trivial_assign (type)
5158  // is true then the trait is true, else if type is a cv class
5159  // or union type with copy assignment operators that are known
5160  // not to throw an exception then the trait is true, else it is
5161  // false.
5162  if (C.getBaseElementType(T).isConstQualified())
5163  return false;
5164  if (T->isReferenceType())
5165  return false;
5166  if (T.isPODType(C) || T->isObjCLifetimeType())
5167  return true;
5168 
5169  if (const RecordType *RT = T->getAs<RecordType>())
5170  return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
5174  return false;
5175  case UTT_HasNothrowMoveAssign:
5176  // This trait is implemented by MSVC 2012 and needed to parse the
5177  // standard library headers. Specifically this is used as the logic
5178  // behind std::is_nothrow_move_assignable (20.9.4.3).
5179  if (T.isPODType(C))
5180  return true;
5181 
5182  if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>())
5183  return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
5187  return false;
5188  case UTT_HasNothrowCopy:
5189  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5190  // If __has_trivial_copy (type) is true then the trait is true, else
5191  // if type is a cv class or union type with copy constructors that are
5192  // known not to throw an exception then the trait is true, else it is
5193  // false.
5194  if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType())
5195  return true;
5196  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
5197  if (RD->hasTrivialCopyConstructor() &&
5199  return true;
5200 
5201  bool FoundConstructor = false;
5202  unsigned FoundTQs;
5203  for (const auto *ND : Self.LookupConstructors(RD)) {
5204  // A template constructor is never a copy constructor.
5205  // FIXME: However, it may actually be selected at the actual overload
5206  // resolution point.
5207  if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
5208  continue;
5209  // UsingDecl itself is not a constructor
5210  if (isa<UsingDecl>(ND))
5211  continue;
5212  auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
5213  if (Constructor->isCopyConstructor(FoundTQs)) {
5214  FoundConstructor = true;
5215  auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
5216  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5217  if (!CPT)
5218  return false;
5219  // TODO: check whether evaluating default arguments can throw.
5220  // For now, we'll be conservative and assume that they can throw.
5221  if (!CPT->isNothrow() || CPT->getNumParams() > 1)
5222  return false;
5223  }
5224  }
5225 
5226  return FoundConstructor;
5227  }
5228  return false;
5229  case UTT_HasNothrowConstructor:
5230  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
5231  // If __has_trivial_constructor (type) is true then the trait is
5232  // true, else if type is a cv class or union type (or array
5233  // thereof) with a default constructor that is known not to
5234  // throw an exception then the trait is true, else it is false.
5235  if (T.isPODType(C) || T->isObjCLifetimeType())
5236  return true;
5237  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
5238  if (RD->hasTrivialDefaultConstructor() &&
5240  return true;
5241 
5242  bool FoundConstructor = false;
5243  for (const auto *ND : Self.LookupConstructors(RD)) {
5244  // FIXME: In C++0x, a constructor template can be a default constructor.
5245  if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
5246  continue;
5247  // UsingDecl itself is not a constructor
5248  if (isa<UsingDecl>(ND))
5249  continue;
5250  auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
5251  if (Constructor->isDefaultConstructor()) {
5252  FoundConstructor = true;
5253  auto *CPT = Constructor->getType()->castAs<FunctionProtoType>();
5254  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
5255  if (!CPT)
5256  return false;
5257  // FIXME: check whether evaluating default arguments can throw.
5258  // For now, we'll be conservative and assume that they can throw.
5259  if (!CPT->isNothrow() || CPT->getNumParams() > 0)
5260  return false;
5261  }
5262  }
5263  return FoundConstructor;
5264  }
5265  return false;
5266  case UTT_HasVirtualDestructor:
5267  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
5268  // If type is a class type with a virtual destructor ([class.dtor])
5269  // then the trait is true, else it is false.
5270  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
5271  if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD))
5272  return Destructor->isVirtual();
5273  return false;
5274 
5275  // These type trait expressions are modeled on the specifications for the
5276  // Embarcadero C++0x type trait functions:
5277  // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
5278  case UTT_IsCompleteType:
5279  // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_):
5280  // Returns True if and only if T is a complete type at the point of the
5281  // function call.
5282  return !T->isIncompleteType();
5283  case UTT_HasUniqueObjectRepresentations:
5284  return C.hasUniqueObjectRepresentations(T);
5285  case UTT_IsTriviallyRelocatable:
5286  return T.isTriviallyRelocatableType(C);
5287  }
5288 }
5289 
5290 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
5291  QualType RhsT, SourceLocation KeyLoc);
5292 
5295  SourceLocation RParenLoc) {
5296  if (Kind <= UTT_Last)
5297  return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType());
5298 
5299  // Evaluate BTT_ReferenceBindsToTemporary alongside the IsConstructible
5300  // traits to avoid duplication.
5301  if (Kind <= BTT_Last && Kind != BTT_ReferenceBindsToTemporary)
5302  return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(),
5303  Args[1]->getType(), RParenLoc);
5304 
5305  switch (Kind) {
5306  case clang::BTT_ReferenceBindsToTemporary:
5307  case clang::TT_IsConstructible:
5308  case clang::TT_IsNothrowConstructible:
5309  case clang::TT_IsTriviallyConstructible: {
5310  // C++11 [meta.unary.prop]:
5311  // is_trivially_constructible is defined as:
5312  //
5313  // is_constructible<T, Args...>::value is true and the variable
5314  // definition for is_constructible, as defined below, is known to call
5315  // no operation that is not trivial.
5316  //
5317  // The predicate condition for a template specialization
5318  // is_constructible<T, Args...> shall be satisfied if and only if the
5319  // following variable definition would be well-formed for some invented
5320  // variable t:
5321  //
5322  // T t(create<Args>()...);
5323  assert(!Args.empty());
5324 
5325  // Precondition: T and all types in the parameter pack Args shall be
5326  // complete types, (possibly cv-qualified) void, or arrays of
5327  // unknown bound.
5328  for (const auto *TSI : Args) {
5329  QualType ArgTy = TSI->getType();
5330  if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType())
5331  continue;
5332 
5333  if (S.RequireCompleteType(KWLoc, ArgTy,
5334  diag::err_incomplete_type_used_in_type_trait_expr))
5335  return false;
5336  }
5337 
5338  // Make sure the first argument is not incomplete nor a function type.
5339  QualType T = Args[0]->getType();
5340  if (T->isIncompleteType() || T->isFunctionType())
5341  return false;
5342 
5343  // Make sure the first argument is not an abstract type.
5344  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
5345  if (RD && RD->isAbstract())
5346  return false;
5347 
5348  llvm::BumpPtrAllocator OpaqueExprAllocator;
5349  SmallVector<Expr *, 2> ArgExprs;
5350  ArgExprs.reserve(Args.size() - 1);
5351  for (unsigned I = 1, N = Args.size(); I != N; ++I) {
5352  QualType ArgTy = Args[I]->getType();
5353  if (ArgTy->isObjectType() || ArgTy->isFunctionType())
5354  ArgTy = S.Context.getRValueReferenceType(ArgTy);
5355  ArgExprs.push_back(
5356  new (OpaqueExprAllocator.Allocate<OpaqueValueExpr>())
5357  OpaqueValueExpr(Args[I]->getTypeLoc().getBeginLoc(),
5358  ArgTy.getNonLValueExprType(S.Context),
5359  Expr::getValueKindForType(ArgTy)));
5