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SemaExprCXX.cpp
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1 //===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief Implements semantic analysis for C++ expressions.
12 ///
13 //===----------------------------------------------------------------------===//
14 
16 #include "TreeTransform.h"
17 #include "TypeLocBuilder.h"
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/ASTLambda.h"
21 #include "clang/AST/CharUnits.h"
22 #include "clang/AST/DeclObjC.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/AST/ExprObjC.h"
26 #include "clang/AST/TypeLoc.h"
29 #include "clang/Basic/TargetInfo.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"
37 #include "clang/Sema/SemaLambda.h"
39 #include "llvm/ADT/APInt.h"
40 #include "llvm/ADT/STLExtras.h"
41 #include "llvm/Support/ErrorHandling.h"
42 using namespace clang;
43 using namespace sema;
44 
45 /// \brief Handle the result of the special case name lookup for inheriting
46 /// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as
47 /// constructor names in member using declarations, even if 'X' is not the
48 /// name of the corresponding type.
50  SourceLocation NameLoc,
51  IdentifierInfo &Name) {
52  NestedNameSpecifier *NNS = SS.getScopeRep();
53 
54  // Convert the nested-name-specifier into a type.
55  QualType Type;
56  switch (NNS->getKind()) {
59  Type = QualType(NNS->getAsType(), 0);
60  break;
61 
63  // Strip off the last layer of the nested-name-specifier and build a
64  // typename type for it.
65  assert(NNS->getAsIdentifier() == &Name && "not a constructor name");
66  Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(),
67  NNS->getAsIdentifier());
68  break;
69 
74  llvm_unreachable("Nested name specifier is not a type for inheriting ctor");
75  }
76 
77  // This reference to the type is located entirely at the location of the
78  // final identifier in the qualified-id.
79  return CreateParsedType(Type,
80  Context.getTrivialTypeSourceInfo(Type, NameLoc));
81 }
82 
84  IdentifierInfo &II,
85  SourceLocation NameLoc,
86  Scope *S, CXXScopeSpec &SS,
87  ParsedType ObjectTypePtr,
88  bool EnteringContext) {
89  // Determine where to perform name lookup.
90 
91  // FIXME: This area of the standard is very messy, and the current
92  // wording is rather unclear about which scopes we search for the
93  // destructor name; see core issues 399 and 555. Issue 399 in
94  // particular shows where the current description of destructor name
95  // lookup is completely out of line with existing practice, e.g.,
96  // this appears to be ill-formed:
97  //
98  // namespace N {
99  // template <typename T> struct S {
100  // ~S();
101  // };
102  // }
103  //
104  // void f(N::S<int>* s) {
105  // s->N::S<int>::~S();
106  // }
107  //
108  // See also PR6358 and PR6359.
109  // For this reason, we're currently only doing the C++03 version of this
110  // code; the C++0x version has to wait until we get a proper spec.
111  QualType SearchType;
112  DeclContext *LookupCtx = nullptr;
113  bool isDependent = false;
114  bool LookInScope = false;
115 
116  if (SS.isInvalid())
117  return nullptr;
118 
119  // If we have an object type, it's because we are in a
120  // pseudo-destructor-expression or a member access expression, and
121  // we know what type we're looking for.
122  if (ObjectTypePtr)
123  SearchType = GetTypeFromParser(ObjectTypePtr);
124 
125  if (SS.isSet()) {
126  NestedNameSpecifier *NNS = SS.getScopeRep();
127 
128  bool AlreadySearched = false;
129  bool LookAtPrefix = true;
130  // C++11 [basic.lookup.qual]p6:
131  // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier,
132  // the type-names are looked up as types in the scope designated by the
133  // nested-name-specifier. Similarly, in a qualified-id of the form:
134  //
135  // nested-name-specifier[opt] class-name :: ~ class-name
136  //
137  // the second class-name is looked up in the same scope as the first.
138  //
139  // Here, we determine whether the code below is permitted to look at the
140  // prefix of the nested-name-specifier.
141  DeclContext *DC = computeDeclContext(SS, EnteringContext);
142  if (DC && DC->isFileContext()) {
143  AlreadySearched = true;
144  LookupCtx = DC;
145  isDependent = false;
146  } else if (DC && isa<CXXRecordDecl>(DC)) {
147  LookAtPrefix = false;
148  LookInScope = true;
149  }
150 
151  // The second case from the C++03 rules quoted further above.
152  NestedNameSpecifier *Prefix = nullptr;
153  if (AlreadySearched) {
154  // Nothing left to do.
155  } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) {
156  CXXScopeSpec PrefixSS;
157  PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
158  LookupCtx = computeDeclContext(PrefixSS, EnteringContext);
159  isDependent = isDependentScopeSpecifier(PrefixSS);
160  } else if (ObjectTypePtr) {
161  LookupCtx = computeDeclContext(SearchType);
162  isDependent = SearchType->isDependentType();
163  } else {
164  LookupCtx = computeDeclContext(SS, EnteringContext);
165  isDependent = LookupCtx && LookupCtx->isDependentContext();
166  }
167  } else if (ObjectTypePtr) {
168  // C++ [basic.lookup.classref]p3:
169  // If the unqualified-id is ~type-name, the type-name is looked up
170  // in the context of the entire postfix-expression. If the type T
171  // of the object expression is of a class type C, the type-name is
172  // also looked up in the scope of class C. At least one of the
173  // lookups shall find a name that refers to (possibly
174  // cv-qualified) T.
175  LookupCtx = computeDeclContext(SearchType);
176  isDependent = SearchType->isDependentType();
177  assert((isDependent || !SearchType->isIncompleteType()) &&
178  "Caller should have completed object type");
179 
180  LookInScope = true;
181  } else {
182  // Perform lookup into the current scope (only).
183  LookInScope = true;
184  }
185 
186  TypeDecl *NonMatchingTypeDecl = nullptr;
187  LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName);
188  for (unsigned Step = 0; Step != 2; ++Step) {
189  // Look for the name first in the computed lookup context (if we
190  // have one) and, if that fails to find a match, in the scope (if
191  // we're allowed to look there).
192  Found.clear();
193  if (Step == 0 && LookupCtx) {
194  if (RequireCompleteDeclContext(SS, LookupCtx))
195  return nullptr;
196  LookupQualifiedName(Found, LookupCtx);
197  } else if (Step == 1 && LookInScope && S) {
198  LookupName(Found, S);
199  } else {
200  continue;
201  }
202 
203  // FIXME: Should we be suppressing ambiguities here?
204  if (Found.isAmbiguous())
205  return nullptr;
206 
207  if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
208  QualType T = Context.getTypeDeclType(Type);
209  MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
210 
211  if (SearchType.isNull() || SearchType->isDependentType() ||
212  Context.hasSameUnqualifiedType(T, SearchType)) {
213  // We found our type!
214 
215  return CreateParsedType(T,
216  Context.getTrivialTypeSourceInfo(T, NameLoc));
217  }
218 
219  if (!SearchType.isNull())
220  NonMatchingTypeDecl = Type;
221  }
222 
223  // If the name that we found is a class template name, and it is
224  // the same name as the template name in the last part of the
225  // nested-name-specifier (if present) or the object type, then
226  // this is the destructor for that class.
227  // FIXME: This is a workaround until we get real drafting for core
228  // issue 399, for which there isn't even an obvious direction.
229  if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) {
230  QualType MemberOfType;
231  if (SS.isSet()) {
232  if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) {
233  // Figure out the type of the context, if it has one.
234  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx))
235  MemberOfType = Context.getTypeDeclType(Record);
236  }
237  }
238  if (MemberOfType.isNull())
239  MemberOfType = SearchType;
240 
241  if (MemberOfType.isNull())
242  continue;
243 
244  // We're referring into a class template specialization. If the
245  // class template we found is the same as the template being
246  // specialized, we found what we are looking for.
247  if (const RecordType *Record = MemberOfType->getAs<RecordType>()) {
249  = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) {
250  if (Spec->getSpecializedTemplate()->getCanonicalDecl() ==
251  Template->getCanonicalDecl())
252  return CreateParsedType(
253  MemberOfType,
254  Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
255  }
256 
257  continue;
258  }
259 
260  // We're referring to an unresolved class template
261  // specialization. Determine whether we class template we found
262  // is the same as the template being specialized or, if we don't
263  // know which template is being specialized, that it at least
264  // has the same name.
265  if (const TemplateSpecializationType *SpecType
266  = MemberOfType->getAs<TemplateSpecializationType>()) {
267  TemplateName SpecName = SpecType->getTemplateName();
268 
269  // The class template we found is the same template being
270  // specialized.
271  if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) {
272  if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl())
273  return CreateParsedType(
274  MemberOfType,
275  Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
276 
277  continue;
278  }
279 
280  // The class template we found has the same name as the
281  // (dependent) template name being specialized.
282  if (DependentTemplateName *DepTemplate
283  = SpecName.getAsDependentTemplateName()) {
284  if (DepTemplate->isIdentifier() &&
285  DepTemplate->getIdentifier() == Template->getIdentifier())
286  return CreateParsedType(
287  MemberOfType,
288  Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
289 
290  continue;
291  }
292  }
293  }
294  }
295 
296  if (isDependent) {
297  // We didn't find our type, but that's okay: it's dependent
298  // anyway.
299 
300  // FIXME: What if we have no nested-name-specifier?
301  QualType T = CheckTypenameType(ETK_None, SourceLocation(),
302  SS.getWithLocInContext(Context),
303  II, NameLoc);
304  return ParsedType::make(T);
305  }
306 
307  if (NonMatchingTypeDecl) {
308  QualType T = Context.getTypeDeclType(NonMatchingTypeDecl);
309  Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
310  << T << SearchType;
311  Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here)
312  << T;
313  } else if (ObjectTypePtr)
314  Diag(NameLoc, diag::err_ident_in_dtor_not_a_type)
315  << &II;
316  else {
317  SemaDiagnosticBuilder DtorDiag = Diag(NameLoc,
318  diag::err_destructor_class_name);
319  if (S) {
320  const DeclContext *Ctx = S->getEntity();
321  if (const CXXRecordDecl *Class = dyn_cast_or_null<CXXRecordDecl>(Ctx))
322  DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc),
323  Class->getNameAsString());
324  }
325  }
326 
327  return nullptr;
328 }
329 
331  ParsedType ObjectType) {
333  return nullptr;
334 
336  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
337  return nullptr;
338  }
339 
340  assert(DS.getTypeSpecType() == DeclSpec::TST_decltype &&
341  "unexpected type in getDestructorType");
342  QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
343 
344  // If we know the type of the object, check that the correct destructor
345  // type was named now; we can give better diagnostics this way.
346  QualType SearchType = GetTypeFromParser(ObjectType);
347  if (!SearchType.isNull() && !SearchType->isDependentType() &&
348  !Context.hasSameUnqualifiedType(T, SearchType)) {
349  Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
350  << T << SearchType;
351  return nullptr;
352  }
353 
354  return ParsedType::make(T);
355 }
356 
358  const UnqualifiedId &Name) {
360 
361  if (!SS.isValid())
362  return false;
363 
364  switch (SS.getScopeRep()->getKind()) {
368  // Per C++11 [over.literal]p2, literal operators can only be declared at
369  // namespace scope. Therefore, this unqualified-id cannot name anything.
370  // Reject it early, because we have no AST representation for this in the
371  // case where the scope is dependent.
372  Diag(Name.getLocStart(), diag::err_literal_operator_id_outside_namespace)
373  << SS.getScopeRep();
374  return true;
375 
380  return false;
381  }
382 
383  llvm_unreachable("unknown nested name specifier kind");
384 }
385 
386 /// \brief Build a C++ typeid expression with a type operand.
388  SourceLocation TypeidLoc,
389  TypeSourceInfo *Operand,
390  SourceLocation RParenLoc) {
391  // C++ [expr.typeid]p4:
392  // The top-level cv-qualifiers of the lvalue expression or the type-id
393  // that is the operand of typeid are always ignored.
394  // If the type of the type-id is a class type or a reference to a class
395  // type, the class shall be completely-defined.
396  Qualifiers Quals;
397  QualType T
398  = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
399  Quals);
400  if (T->getAs<RecordType>() &&
401  RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
402  return ExprError();
403 
404  if (T->isVariablyModifiedType())
405  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);
406 
407  return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
408  SourceRange(TypeidLoc, RParenLoc));
409 }
410 
411 /// \brief Build a C++ typeid expression with an expression operand.
413  SourceLocation TypeidLoc,
414  Expr *E,
415  SourceLocation RParenLoc) {
416  bool WasEvaluated = false;
417  if (E && !E->isTypeDependent()) {
418  if (E->getType()->isPlaceholderType()) {
419  ExprResult result = CheckPlaceholderExpr(E);
420  if (result.isInvalid()) return ExprError();
421  E = result.get();
422  }
423 
424  QualType T = E->getType();
425  if (const RecordType *RecordT = T->getAs<RecordType>()) {
426  CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
427  // C++ [expr.typeid]p3:
428  // [...] If the type of the expression is a class type, the class
429  // shall be completely-defined.
430  if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
431  return ExprError();
432 
433  // C++ [expr.typeid]p3:
434  // When typeid is applied to an expression other than an glvalue of a
435  // polymorphic class type [...] [the] expression is an unevaluated
436  // operand. [...]
437  if (RecordD->isPolymorphic() && E->isGLValue()) {
438  // The subexpression is potentially evaluated; switch the context
439  // and recheck the subexpression.
440  ExprResult Result = TransformToPotentiallyEvaluated(E);
441  if (Result.isInvalid()) return ExprError();
442  E = Result.get();
443 
444  // We require a vtable to query the type at run time.
445  MarkVTableUsed(TypeidLoc, RecordD);
446  WasEvaluated = true;
447  }
448  }
449 
450  // C++ [expr.typeid]p4:
451  // [...] If the type of the type-id is a reference to a possibly
452  // cv-qualified type, the result of the typeid expression refers to a
453  // std::type_info object representing the cv-unqualified referenced
454  // type.
455  Qualifiers Quals;
456  QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
457  if (!Context.hasSameType(T, UnqualT)) {
458  T = UnqualT;
459  E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
460  }
461  }
462 
463  if (E->getType()->isVariablyModifiedType())
464  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
465  << E->getType());
466  else if (!inTemplateInstantiation() &&
467  E->HasSideEffects(Context, WasEvaluated)) {
468  // The expression operand for typeid is in an unevaluated expression
469  // context, so side effects could result in unintended consequences.
470  Diag(E->getExprLoc(), WasEvaluated
471  ? diag::warn_side_effects_typeid
472  : diag::warn_side_effects_unevaluated_context);
473  }
474 
475  return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
476  SourceRange(TypeidLoc, RParenLoc));
477 }
478 
479 /// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
482  bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
483  // Find the std::type_info type.
484  if (!getStdNamespace())
485  return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
486 
487  if (!CXXTypeInfoDecl) {
488  IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
489  LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
490  LookupQualifiedName(R, getStdNamespace());
491  CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
492  // Microsoft's typeinfo doesn't have type_info in std but in the global
493  // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
494  if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
495  LookupQualifiedName(R, Context.getTranslationUnitDecl());
496  CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
497  }
498  if (!CXXTypeInfoDecl)
499  return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
500  }
501 
502  if (!getLangOpts().RTTI) {
503  return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
504  }
505 
506  QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);
507 
508  if (isType) {
509  // The operand is a type; handle it as such.
510  TypeSourceInfo *TInfo = nullptr;
511  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
512  &TInfo);
513  if (T.isNull())
514  return ExprError();
515 
516  if (!TInfo)
517  TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
518 
519  return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
520  }
521 
522  // The operand is an expression.
523  return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
524 }
525 
526 /// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to
527 /// a single GUID.
528 static void
531  // Optionally remove one level of pointer, reference or array indirection.
532  const Type *Ty = QT.getTypePtr();
533  if (QT->isPointerType() || QT->isReferenceType())
534  Ty = QT->getPointeeType().getTypePtr();
535  else if (QT->isArrayType())
536  Ty = Ty->getBaseElementTypeUnsafe();
537 
538  const auto *TD = Ty->getAsTagDecl();
539  if (!TD)
540  return;
541 
542  if (const auto *Uuid = TD->getMostRecentDecl()->getAttr<UuidAttr>()) {
543  UuidAttrs.insert(Uuid);
544  return;
545  }
546 
547  // __uuidof can grab UUIDs from template arguments.
548  if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(TD)) {
549  const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
550  for (const TemplateArgument &TA : TAL.asArray()) {
551  const UuidAttr *UuidForTA = nullptr;
552  if (TA.getKind() == TemplateArgument::Type)
553  getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs);
554  else if (TA.getKind() == TemplateArgument::Declaration)
555  getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs);
556 
557  if (UuidForTA)
558  UuidAttrs.insert(UuidForTA);
559  }
560  }
561 }
562 
563 /// \brief Build a Microsoft __uuidof expression with a type operand.
565  SourceLocation TypeidLoc,
566  TypeSourceInfo *Operand,
567  SourceLocation RParenLoc) {
568  StringRef UuidStr;
569  if (!Operand->getType()->isDependentType()) {
571  getUuidAttrOfType(*this, Operand->getType(), UuidAttrs);
572  if (UuidAttrs.empty())
573  return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
574  if (UuidAttrs.size() > 1)
575  return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
576  UuidStr = UuidAttrs.back()->getGuid();
577  }
578 
579  return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand, UuidStr,
580  SourceRange(TypeidLoc, RParenLoc));
581 }
582 
583 /// \brief Build a Microsoft __uuidof expression with an expression operand.
585  SourceLocation TypeidLoc,
586  Expr *E,
587  SourceLocation RParenLoc) {
588  StringRef UuidStr;
589  if (!E->getType()->isDependentType()) {
591  UuidStr = "00000000-0000-0000-0000-000000000000";
592  } else {
594  getUuidAttrOfType(*this, E->getType(), UuidAttrs);
595  if (UuidAttrs.empty())
596  return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
597  if (UuidAttrs.size() > 1)
598  return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
599  UuidStr = UuidAttrs.back()->getGuid();
600  }
601  }
602 
603  return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E, UuidStr,
604  SourceRange(TypeidLoc, RParenLoc));
605 }
606 
607 /// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
610  bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
611  // If MSVCGuidDecl has not been cached, do the lookup.
612  if (!MSVCGuidDecl) {
613  IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID");
614  LookupResult R(*this, GuidII, SourceLocation(), LookupTagName);
615  LookupQualifiedName(R, Context.getTranslationUnitDecl());
616  MSVCGuidDecl = R.getAsSingle<RecordDecl>();
617  if (!MSVCGuidDecl)
618  return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof));
619  }
620 
621  QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl);
622 
623  if (isType) {
624  // The operand is a type; handle it as such.
625  TypeSourceInfo *TInfo = nullptr;
626  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
627  &TInfo);
628  if (T.isNull())
629  return ExprError();
630 
631  if (!TInfo)
632  TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
633 
634  return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
635  }
636 
637  // The operand is an expression.
638  return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
639 }
640 
641 /// ActOnCXXBoolLiteral - Parse {true,false} literals.
644  assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
645  "Unknown C++ Boolean value!");
646  return new (Context)
647  CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
648 }
649 
650 /// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
653  return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
654 }
655 
656 /// ActOnCXXThrow - Parse throw expressions.
659  bool IsThrownVarInScope = false;
660  if (Ex) {
661  // C++0x [class.copymove]p31:
662  // When certain criteria are met, an implementation is allowed to omit the
663  // copy/move construction of a class object [...]
664  //
665  // - in a throw-expression, when the operand is the name of a
666  // non-volatile automatic object (other than a function or catch-
667  // clause parameter) whose scope does not extend beyond the end of the
668  // innermost enclosing try-block (if there is one), the copy/move
669  // operation from the operand to the exception object (15.1) can be
670  // omitted by constructing the automatic object directly into the
671  // exception object
672  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
673  if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
674  if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
675  for( ; S; S = S->getParent()) {
676  if (S->isDeclScope(Var)) {
677  IsThrownVarInScope = true;
678  break;
679  }
680 
681  if (S->getFlags() &
685  break;
686  }
687  }
688  }
689  }
690 
691  return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
692 }
693 
695  bool IsThrownVarInScope) {
696  // Don't report an error if 'throw' is used in system headers.
697  if (!getLangOpts().CXXExceptions &&
698  !getSourceManager().isInSystemHeader(OpLoc))
699  Diag(OpLoc, diag::err_exceptions_disabled) << "throw";
700 
701  // Exceptions aren't allowed in CUDA device code.
702  if (getLangOpts().CUDA)
703  CUDADiagIfDeviceCode(OpLoc, diag::err_cuda_device_exceptions)
704  << "throw" << CurrentCUDATarget();
705 
706  if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
707  Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";
708 
709  if (Ex && !Ex->isTypeDependent()) {
710  QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
711  if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
712  return ExprError();
713 
714  // Initialize the exception result. This implicitly weeds out
715  // abstract types or types with inaccessible copy constructors.
716 
717  // C++0x [class.copymove]p31:
718  // When certain criteria are met, an implementation is allowed to omit the
719  // copy/move construction of a class object [...]
720  //
721  // - in a throw-expression, when the operand is the name of a
722  // non-volatile automatic object (other than a function or
723  // catch-clause
724  // parameter) whose scope does not extend beyond the end of the
725  // innermost enclosing try-block (if there is one), the copy/move
726  // operation from the operand to the exception object (15.1) can be
727  // omitted by constructing the automatic object directly into the
728  // exception object
729  const VarDecl *NRVOVariable = nullptr;
730  if (IsThrownVarInScope)
731  NRVOVariable = getCopyElisionCandidate(QualType(), Ex, false);
732 
734  OpLoc, ExceptionObjectTy,
735  /*NRVO=*/NRVOVariable != nullptr);
736  ExprResult Res = PerformMoveOrCopyInitialization(
737  Entity, NRVOVariable, QualType(), Ex, IsThrownVarInScope);
738  if (Res.isInvalid())
739  return ExprError();
740  Ex = Res.get();
741  }
742 
743  return new (Context)
744  CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
745 }
746 
747 static void
749  llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen,
750  llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases,
751  llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen,
752  bool ParentIsPublic) {
753  for (const CXXBaseSpecifier &BS : RD->bases()) {
754  CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
755  bool NewSubobject;
756  // Virtual bases constitute the same subobject. Non-virtual bases are
757  // always distinct subobjects.
758  if (BS.isVirtual())
759  NewSubobject = VBases.insert(BaseDecl).second;
760  else
761  NewSubobject = true;
762 
763  if (NewSubobject)
764  ++SubobjectsSeen[BaseDecl];
765 
766  // Only add subobjects which have public access throughout the entire chain.
767  bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public;
768  if (PublicPath)
769  PublicSubobjectsSeen.insert(BaseDecl);
770 
771  // Recurse on to each base subobject.
772  collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen,
773  PublicPath);
774  }
775 }
776 
779  llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen;
780  llvm::SmallSet<CXXRecordDecl *, 2> VBases;
781  llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen;
782  SubobjectsSeen[RD] = 1;
783  PublicSubobjectsSeen.insert(RD);
784  collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen,
785  /*ParentIsPublic=*/true);
786 
787  for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) {
788  // Skip ambiguous objects.
789  if (SubobjectsSeen[PublicSubobject] > 1)
790  continue;
791 
792  Objects.push_back(PublicSubobject);
793  }
794 }
795 
796 /// CheckCXXThrowOperand - Validate the operand of a throw.
798  QualType ExceptionObjectTy, Expr *E) {
799  // If the type of the exception would be an incomplete type or a pointer
800  // to an incomplete type other than (cv) void the program is ill-formed.
801  QualType Ty = ExceptionObjectTy;
802  bool isPointer = false;
803  if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
804  Ty = Ptr->getPointeeType();
805  isPointer = true;
806  }
807  if (!isPointer || !Ty->isVoidType()) {
808  if (RequireCompleteType(ThrowLoc, Ty,
809  isPointer ? diag::err_throw_incomplete_ptr
810  : diag::err_throw_incomplete,
811  E->getSourceRange()))
812  return true;
813 
814  if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy,
815  diag::err_throw_abstract_type, E))
816  return true;
817  }
818 
819  // If the exception has class type, we need additional handling.
820  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
821  if (!RD)
822  return false;
823 
824  // If we are throwing a polymorphic class type or pointer thereof,
825  // exception handling will make use of the vtable.
826  MarkVTableUsed(ThrowLoc, RD);
827 
828  // If a pointer is thrown, the referenced object will not be destroyed.
829  if (isPointer)
830  return false;
831 
832  // If the class has a destructor, we must be able to call it.
833  if (!RD->hasIrrelevantDestructor()) {
834  if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
835  MarkFunctionReferenced(E->getExprLoc(), Destructor);
836  CheckDestructorAccess(E->getExprLoc(), Destructor,
837  PDiag(diag::err_access_dtor_exception) << Ty);
838  if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
839  return true;
840  }
841  }
842 
843  // The MSVC ABI creates a list of all types which can catch the exception
844  // object. This list also references the appropriate copy constructor to call
845  // if the object is caught by value and has a non-trivial copy constructor.
846  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
847  // We are only interested in the public, unambiguous bases contained within
848  // the exception object. Bases which are ambiguous or otherwise
849  // inaccessible are not catchable types.
850  llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects;
851  getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects);
852 
853  for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) {
854  // Attempt to lookup the copy constructor. Various pieces of machinery
855  // will spring into action, like template instantiation, which means this
856  // cannot be a simple walk of the class's decls. Instead, we must perform
857  // lookup and overload resolution.
858  CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
859  if (!CD)
860  continue;
861 
862  // Mark the constructor referenced as it is used by this throw expression.
863  MarkFunctionReferenced(E->getExprLoc(), CD);
864 
865  // Skip this copy constructor if it is trivial, we don't need to record it
866  // in the catchable type data.
867  if (CD->isTrivial())
868  continue;
869 
870  // The copy constructor is non-trivial, create a mapping from this class
871  // type to this constructor.
872  // N.B. The selection of copy constructor is not sensitive to this
873  // particular throw-site. Lookup will be performed at the catch-site to
874  // ensure that the copy constructor is, in fact, accessible (via
875  // friendship or any other means).
876  Context.addCopyConstructorForExceptionObject(Subobject, CD);
877 
878  // We don't keep the instantiated default argument expressions around so
879  // we must rebuild them here.
880  for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) {
881  if (CheckCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)))
882  return true;
883  }
884  }
885  }
886 
887  return false;
888 }
889 
891  ArrayRef<FunctionScopeInfo *> FunctionScopes, QualType ThisTy,
892  DeclContext *CurSemaContext, ASTContext &ASTCtx) {
893 
894  QualType ClassType = ThisTy->getPointeeType();
895  LambdaScopeInfo *CurLSI = nullptr;
896  DeclContext *CurDC = CurSemaContext;
897 
898  // Iterate through the stack of lambdas starting from the innermost lambda to
899  // the outermost lambda, checking if '*this' is ever captured by copy - since
900  // that could change the cv-qualifiers of the '*this' object.
901  // The object referred to by '*this' starts out with the cv-qualifiers of its
902  // member function. We then start with the innermost lambda and iterate
903  // outward checking to see if any lambda performs a by-copy capture of '*this'
904  // - and if so, any nested lambda must respect the 'constness' of that
905  // capturing lamdbda's call operator.
906  //
907 
908  // Since the FunctionScopeInfo stack is representative of the lexical
909  // nesting of the lambda expressions during initial parsing (and is the best
910  // place for querying information about captures about lambdas that are
911  // partially processed) and perhaps during instantiation of function templates
912  // that contain lambda expressions that need to be transformed BUT not
913  // necessarily during instantiation of a nested generic lambda's function call
914  // operator (which might even be instantiated at the end of the TU) - at which
915  // time the DeclContext tree is mature enough to query capture information
916  // reliably - we use a two pronged approach to walk through all the lexically
917  // enclosing lambda expressions:
918  //
919  // 1) Climb down the FunctionScopeInfo stack as long as each item represents
920  // a Lambda (i.e. LambdaScopeInfo) AND each LSI's 'closure-type' is lexically
921  // enclosed by the call-operator of the LSI below it on the stack (while
922  // tracking the enclosing DC for step 2 if needed). Note the topmost LSI on
923  // the stack represents the innermost lambda.
924  //
925  // 2) If we run out of enclosing LSI's, check if the enclosing DeclContext
926  // represents a lambda's call operator. If it does, we must be instantiating
927  // a generic lambda's call operator (represented by the Current LSI, and
928  // should be the only scenario where an inconsistency between the LSI and the
929  // DeclContext should occur), so climb out the DeclContexts if they
930  // represent lambdas, while querying the corresponding closure types
931  // regarding capture information.
932 
933  // 1) Climb down the function scope info stack.
934  for (int I = FunctionScopes.size();
935  I-- && isa<LambdaScopeInfo>(FunctionScopes[I]) &&
936  (!CurLSI || !CurLSI->Lambda || CurLSI->Lambda->getDeclContext() ==
937  cast<LambdaScopeInfo>(FunctionScopes[I])->CallOperator);
938  CurDC = getLambdaAwareParentOfDeclContext(CurDC)) {
939  CurLSI = cast<LambdaScopeInfo>(FunctionScopes[I]);
940 
941  if (!CurLSI->isCXXThisCaptured())
942  continue;
943 
944  auto C = CurLSI->getCXXThisCapture();
945 
946  if (C.isCopyCapture()) {
948  if (CurLSI->CallOperator->isConst())
949  ClassType.addConst();
950  return ASTCtx.getPointerType(ClassType);
951  }
952  }
953 
954  // 2) We've run out of ScopeInfos but check if CurDC is a lambda (which can
955  // happen during instantiation of its nested generic lambda call operator)
956  if (isLambdaCallOperator(CurDC)) {
957  assert(CurLSI && "While computing 'this' capture-type for a generic "
958  "lambda, we must have a corresponding LambdaScopeInfo");
960  "While computing 'this' capture-type for a generic lambda, when we "
961  "run out of enclosing LSI's, yet the enclosing DC is a "
962  "lambda-call-operator we must be (i.e. Current LSI) in a generic "
963  "lambda call oeprator");
964  assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator));
965 
966  auto IsThisCaptured =
967  [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) {
968  IsConst = false;
969  IsByCopy = false;
970  for (auto &&C : Closure->captures()) {
971  if (C.capturesThis()) {
972  if (C.getCaptureKind() == LCK_StarThis)
973  IsByCopy = true;
974  if (Closure->getLambdaCallOperator()->isConst())
975  IsConst = true;
976  return true;
977  }
978  }
979  return false;
980  };
981 
982  bool IsByCopyCapture = false;
983  bool IsConstCapture = false;
984  CXXRecordDecl *Closure = cast<CXXRecordDecl>(CurDC->getParent());
985  while (Closure &&
986  IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) {
987  if (IsByCopyCapture) {
989  if (IsConstCapture)
990  ClassType.addConst();
991  return ASTCtx.getPointerType(ClassType);
992  }
993  Closure = isLambdaCallOperator(Closure->getParent())
994  ? cast<CXXRecordDecl>(Closure->getParent()->getParent())
995  : nullptr;
996  }
997  }
998  return ASTCtx.getPointerType(ClassType);
999 }
1000 
1002  DeclContext *DC = getFunctionLevelDeclContext();
1003  QualType ThisTy = CXXThisTypeOverride;
1004 
1005  if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
1006  if (method && method->isInstance())
1007  ThisTy = method->getThisType(Context);
1008  }
1009 
1010  if (ThisTy.isNull() && isLambdaCallOperator(CurContext) &&
1011  inTemplateInstantiation()) {
1012 
1013  assert(isa<CXXRecordDecl>(DC) &&
1014  "Trying to get 'this' type from static method?");
1015 
1016  // This is a lambda call operator that is being instantiated as a default
1017  // initializer. DC must point to the enclosing class type, so we can recover
1018  // the 'this' type from it.
1019 
1020  QualType ClassTy = Context.getTypeDeclType(cast<CXXRecordDecl>(DC));
1021  // There are no cv-qualifiers for 'this' within default initializers,
1022  // per [expr.prim.general]p4.
1023  ThisTy = Context.getPointerType(ClassTy);
1024  }
1025 
1026  // If we are within a lambda's call operator, the cv-qualifiers of 'this'
1027  // might need to be adjusted if the lambda or any of its enclosing lambda's
1028  // captures '*this' by copy.
1029  if (!ThisTy.isNull() && isLambdaCallOperator(CurContext))
1030  return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy,
1031  CurContext, Context);
1032  return ThisTy;
1033 }
1034 
1036  Decl *ContextDecl,
1037  unsigned CXXThisTypeQuals,
1038  bool Enabled)
1039  : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
1040 {
1041  if (!Enabled || !ContextDecl)
1042  return;
1043 
1044  CXXRecordDecl *Record = nullptr;
1045  if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
1046  Record = Template->getTemplatedDecl();
1047  else
1048  Record = cast<CXXRecordDecl>(ContextDecl);
1049 
1050  // We care only for CVR qualifiers here, so cut everything else.
1051  CXXThisTypeQuals &= Qualifiers::FastMask;
1053  = S.Context.getPointerType(
1054  S.Context.getRecordType(Record).withCVRQualifiers(CXXThisTypeQuals));
1055 
1056  this->Enabled = true;
1057 }
1058 
1059 
1061  if (Enabled) {
1062  S.CXXThisTypeOverride = OldCXXThisTypeOverride;
1063  }
1064 }
1065 
1067  QualType ThisTy, SourceLocation Loc,
1068  const bool ByCopy) {
1069 
1070  QualType AdjustedThisTy = ThisTy;
1071  // The type of the corresponding data member (not a 'this' pointer if 'by
1072  // copy').
1073  QualType CaptureThisFieldTy = ThisTy;
1074  if (ByCopy) {
1075  // If we are capturing the object referred to by '*this' by copy, ignore any
1076  // cv qualifiers inherited from the type of the member function for the type
1077  // of the closure-type's corresponding data member and any use of 'this'.
1078  CaptureThisFieldTy = ThisTy->getPointeeType();
1079  CaptureThisFieldTy.removeLocalCVRQualifiers(Qualifiers::CVRMask);
1080  AdjustedThisTy = Context.getPointerType(CaptureThisFieldTy);
1081  }
1082 
1083  FieldDecl *Field = FieldDecl::Create(
1084  Context, RD, Loc, Loc, nullptr, CaptureThisFieldTy,
1085  Context.getTrivialTypeSourceInfo(CaptureThisFieldTy, Loc), nullptr, false,
1086  ICIS_NoInit);
1087 
1088  Field->setImplicit(true);
1089  Field->setAccess(AS_private);
1090  RD->addDecl(Field);
1091  Expr *This =
1092  new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit*/ true);
1093  if (ByCopy) {
1094  Expr *StarThis = S.CreateBuiltinUnaryOp(Loc,
1095  UO_Deref,
1096  This).get();
1098  nullptr, CaptureThisFieldTy, Loc);
1099  InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc);
1100  InitializationSequence Init(S, Entity, InitKind, StarThis);
1101  ExprResult ER = Init.Perform(S, Entity, InitKind, StarThis);
1102  if (ER.isInvalid()) return nullptr;
1103  return ER.get();
1104  }
1105  return This;
1106 }
1107 
1108 bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
1109  bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
1110  const bool ByCopy) {
1111  // We don't need to capture this in an unevaluated context.
1112  if (isUnevaluatedContext() && !Explicit)
1113  return true;
1114 
1115  assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value");
1116 
1117  const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ?
1118  *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1;
1119 
1120  // Check that we can capture the *enclosing object* (referred to by '*this')
1121  // by the capturing-entity/closure (lambda/block/etc) at
1122  // MaxFunctionScopesIndex-deep on the FunctionScopes stack.
1123 
1124  // Note: The *enclosing object* can only be captured by-value by a
1125  // closure that is a lambda, using the explicit notation:
1126  // [*this] { ... }.
1127  // Every other capture of the *enclosing object* results in its by-reference
1128  // capture.
1129 
1130  // For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes
1131  // stack), we can capture the *enclosing object* only if:
1132  // - 'L' has an explicit byref or byval capture of the *enclosing object*
1133  // - or, 'L' has an implicit capture.
1134  // AND
1135  // -- there is no enclosing closure
1136  // -- or, there is some enclosing closure 'E' that has already captured the
1137  // *enclosing object*, and every intervening closure (if any) between 'E'
1138  // and 'L' can implicitly capture the *enclosing object*.
1139  // -- or, every enclosing closure can implicitly capture the
1140  // *enclosing object*
1141 
1142 
1143  unsigned NumCapturingClosures = 0;
1144  for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) {
1145  if (CapturingScopeInfo *CSI =
1146  dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
1147  if (CSI->CXXThisCaptureIndex != 0) {
1148  // 'this' is already being captured; there isn't anything more to do.
1149  CSI->Captures[CSI->CXXThisCaptureIndex - 1].markUsed(BuildAndDiagnose);
1150  break;
1151  }
1152  LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
1154  // This context can't implicitly capture 'this'; fail out.
1155  if (BuildAndDiagnose)
1156  Diag(Loc, diag::err_this_capture)
1157  << (Explicit && idx == MaxFunctionScopesIndex);
1158  return true;
1159  }
1160  if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
1161  CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||
1162  CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||
1163  CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||
1164  (Explicit && idx == MaxFunctionScopesIndex)) {
1165  // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first
1166  // iteration through can be an explicit capture, all enclosing closures,
1167  // if any, must perform implicit captures.
1168 
1169  // This closure can capture 'this'; continue looking upwards.
1170  NumCapturingClosures++;
1171  continue;
1172  }
1173  // This context can't implicitly capture 'this'; fail out.
1174  if (BuildAndDiagnose)
1175  Diag(Loc, diag::err_this_capture)
1176  << (Explicit && idx == MaxFunctionScopesIndex);
1177  return true;
1178  }
1179  break;
1180  }
1181  if (!BuildAndDiagnose) return false;
1182 
1183  // If we got here, then the closure at MaxFunctionScopesIndex on the
1184  // FunctionScopes stack, can capture the *enclosing object*, so capture it
1185  // (including implicit by-reference captures in any enclosing closures).
1186 
1187  // In the loop below, respect the ByCopy flag only for the closure requesting
1188  // the capture (i.e. first iteration through the loop below). Ignore it for
1189  // all enclosing closure's up to NumCapturingClosures (since they must be
1190  // implicitly capturing the *enclosing object* by reference (see loop
1191  // above)).
1192  assert((!ByCopy ||
1193  dyn_cast<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) &&
1194  "Only a lambda can capture the enclosing object (referred to by "
1195  "*this) by copy");
1196  // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated
1197  // contexts.
1198  QualType ThisTy = getCurrentThisType();
1199  for (unsigned idx = MaxFunctionScopesIndex; NumCapturingClosures;
1200  --idx, --NumCapturingClosures) {
1201  CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
1202  Expr *ThisExpr = nullptr;
1203 
1204  if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI)) {
1205  // For lambda expressions, build a field and an initializing expression,
1206  // and capture the *enclosing object* by copy only if this is the first
1207  // iteration.
1208  ThisExpr = captureThis(*this, Context, LSI->Lambda, ThisTy, Loc,
1209  ByCopy && idx == MaxFunctionScopesIndex);
1210 
1211  } else if (CapturedRegionScopeInfo *RSI
1212  = dyn_cast<CapturedRegionScopeInfo>(FunctionScopes[idx]))
1213  ThisExpr =
1214  captureThis(*this, Context, RSI->TheRecordDecl, ThisTy, Loc,
1215  false/*ByCopy*/);
1216 
1217  bool isNested = NumCapturingClosures > 1;
1218  CSI->addThisCapture(isNested, Loc, ThisExpr, ByCopy);
1219  }
1220  return false;
1221 }
1222 
1224  /// C++ 9.3.2: In the body of a non-static member function, the keyword this
1225  /// is a non-lvalue expression whose value is the address of the object for
1226  /// which the function is called.
1227 
1228  QualType ThisTy = getCurrentThisType();
1229  if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use);
1230 
1231  CheckCXXThisCapture(Loc);
1232  return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false);
1233 }
1234 
1236  // If we're outside the body of a member function, then we'll have a specified
1237  // type for 'this'.
1239  return false;
1240 
1241  // Determine whether we're looking into a class that's currently being
1242  // defined.
1243  CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl();
1244  return Class && Class->isBeingDefined();
1245 }
1246 
1247 ExprResult
1249  SourceLocation LParenLoc,
1250  MultiExprArg exprs,
1251  SourceLocation RParenLoc) {
1252  if (!TypeRep)
1253  return ExprError();
1254 
1255  TypeSourceInfo *TInfo;
1256  QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
1257  if (!TInfo)
1259 
1260  auto Result = BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc);
1261  // Avoid creating a non-type-dependent expression that contains typos.
1262  // Non-type-dependent expressions are liable to be discarded without
1263  // checking for embedded typos.
1264  if (!Result.isInvalid() && Result.get()->isInstantiationDependent() &&
1265  !Result.get()->isTypeDependent())
1267  return Result;
1268 }
1269 
1270 /// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
1271 /// Can be interpreted either as function-style casting ("int(x)")
1272 /// or class type construction ("ClassType(x,y,z)")
1273 /// or creation of a value-initialized type ("int()").
1274 ExprResult
1276  SourceLocation LParenLoc,
1277  MultiExprArg Exprs,
1278  SourceLocation RParenLoc) {
1279  QualType Ty = TInfo->getType();
1280  SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();
1281 
1283  return CXXUnresolvedConstructExpr::Create(Context, TInfo, LParenLoc, Exprs,
1284  RParenLoc);
1285  }
1286 
1287  bool ListInitialization = LParenLoc.isInvalid();
1288  assert((!ListInitialization ||
1289  (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) &&
1290  "List initialization must have initializer list as expression.");
1291  SourceRange FullRange = SourceRange(TyBeginLoc,
1292  ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc);
1293 
1296  Exprs.size()
1297  ? ListInitialization
1299  : InitializationKind::CreateDirect(TyBeginLoc, LParenLoc,
1300  RParenLoc)
1301  : InitializationKind::CreateValue(TyBeginLoc, LParenLoc, RParenLoc);
1302 
1303  // C++1z [expr.type.conv]p1:
1304  // If the type is a placeholder for a deduced class type, [...perform class
1305  // template argument deduction...]
1306  DeducedType *Deduced = Ty->getContainedDeducedType();
1307  if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
1309  Kind, Exprs);
1310  if (Ty.isNull())
1311  return ExprError();
1312  Entity = InitializedEntity::InitializeTemporary(TInfo, Ty);
1313  }
1314 
1315  // C++ [expr.type.conv]p1:
1316  // If the expression list is a parenthesized single expression, the type
1317  // conversion expression is equivalent (in definedness, and if defined in
1318  // meaning) to the corresponding cast expression.
1319  if (Exprs.size() == 1 && !ListInitialization &&
1320  !isa<InitListExpr>(Exprs[0])) {
1321  Expr *Arg = Exprs[0];
1322  return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenLoc, Arg, RParenLoc);
1323  }
1324 
1325  // For an expression of the form T(), T shall not be an array type.
1326  QualType ElemTy = Ty;
1327  if (Ty->isArrayType()) {
1328  if (!ListInitialization)
1329  return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type)
1330  << FullRange);
1331  ElemTy = Context.getBaseElementType(Ty);
1332  }
1333 
1334  // There doesn't seem to be an explicit rule against this but sanity demands
1335  // we only construct objects with object types.
1336  if (Ty->isFunctionType())
1337  return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type)
1338  << Ty << FullRange);
1339 
1340  // C++17 [expr.type.conv]p2:
1341  // If the type is cv void and the initializer is (), the expression is a
1342  // prvalue of the specified type that performs no initialization.
1343  if (!Ty->isVoidType() &&
1344  RequireCompleteType(TyBeginLoc, ElemTy,
1345  diag::err_invalid_incomplete_type_use, FullRange))
1346  return ExprError();
1347 
1348  // Otherwise, the expression is a prvalue of the specified type whose
1349  // result object is direct-initialized (11.6) with the initializer.
1350  InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
1351  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);
1352 
1353  if (Result.isInvalid())
1354  return Result;
1355 
1356  Expr *Inner = Result.get();
1357  if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
1358  Inner = BTE->getSubExpr();
1359  if (!isa<CXXTemporaryObjectExpr>(Inner) &&
1360  !isa<CXXScalarValueInitExpr>(Inner)) {
1361  // If we created a CXXTemporaryObjectExpr, that node also represents the
1362  // functional cast. Otherwise, create an explicit cast to represent
1363  // the syntactic form of a functional-style cast that was used here.
1364  //
1365  // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr
1366  // would give a more consistent AST representation than using a
1367  // CXXTemporaryObjectExpr. It's also weird that the functional cast
1368  // is sometimes handled by initialization and sometimes not.
1369  QualType ResultType = Result.get()->getType();
1371  Context, ResultType, Expr::getValueKindForType(Ty), TInfo,
1372  CK_NoOp, Result.get(), /*Path=*/nullptr, LParenLoc, RParenLoc);
1373  }
1374 
1375  return Result;
1376 }
1377 
1378 /// \brief Determine whether the given function is a non-placement
1379 /// deallocation function.
1381  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
1382  return Method->isUsualDeallocationFunction();
1383 
1384  if (FD->getOverloadedOperator() != OO_Delete &&
1385  FD->getOverloadedOperator() != OO_Array_Delete)
1386  return false;
1387 
1388  unsigned UsualParams = 1;
1389 
1390  if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() &&
1392  FD->getParamDecl(UsualParams)->getType(),
1393  S.Context.getSizeType()))
1394  ++UsualParams;
1395 
1396  if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() &&
1398  FD->getParamDecl(UsualParams)->getType(),
1400  ++UsualParams;
1401 
1402  return UsualParams == FD->getNumParams();
1403 }
1404 
1405 namespace {
1406  struct UsualDeallocFnInfo {
1407  UsualDeallocFnInfo() : Found(), FD(nullptr) {}
1408  UsualDeallocFnInfo(Sema &S, DeclAccessPair Found)
1409  : Found(Found), FD(dyn_cast<FunctionDecl>(Found->getUnderlyingDecl())),
1410  Destroying(false), HasSizeT(false), HasAlignValT(false),
1411  CUDAPref(Sema::CFP_Native) {
1412  // A function template declaration is never a usual deallocation function.
1413  if (!FD)
1414  return;
1415  unsigned NumBaseParams = 1;
1416  if (FD->isDestroyingOperatorDelete()) {
1417  Destroying = true;
1418  ++NumBaseParams;
1419  }
1420  if (FD->getNumParams() == NumBaseParams + 2)
1421  HasAlignValT = HasSizeT = true;
1422  else if (FD->getNumParams() == NumBaseParams + 1) {
1423  HasSizeT = FD->getParamDecl(NumBaseParams)->getType()->isIntegerType();
1424  HasAlignValT = !HasSizeT;
1425  }
1426 
1427  // In CUDA, determine how much we'd like / dislike to call this.
1428  if (S.getLangOpts().CUDA)
1429  if (auto *Caller = dyn_cast<FunctionDecl>(S.CurContext))
1430  CUDAPref = S.IdentifyCUDAPreference(Caller, FD);
1431  }
1432 
1433  operator bool() const { return FD; }
1434 
1435  bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize,
1436  bool WantAlign) const {
1437  // C++ P0722:
1438  // A destroying operator delete is preferred over a non-destroying
1439  // operator delete.
1440  if (Destroying != Other.Destroying)
1441  return Destroying;
1442 
1443  // C++17 [expr.delete]p10:
1444  // If the type has new-extended alignment, a function with a parameter
1445  // of type std::align_val_t is preferred; otherwise a function without
1446  // such a parameter is preferred
1447  if (HasAlignValT != Other.HasAlignValT)
1448  return HasAlignValT == WantAlign;
1449 
1450  if (HasSizeT != Other.HasSizeT)
1451  return HasSizeT == WantSize;
1452 
1453  // Use CUDA call preference as a tiebreaker.
1454  return CUDAPref > Other.CUDAPref;
1455  }
1456 
1457  DeclAccessPair Found;
1458  FunctionDecl *FD;
1459  bool Destroying, HasSizeT, HasAlignValT;
1461  };
1462 }
1463 
1464 /// Determine whether a type has new-extended alignment. This may be called when
1465 /// the type is incomplete (for a delete-expression with an incomplete pointee
1466 /// type), in which case it will conservatively return false if the alignment is
1467 /// not known.
1468 static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) {
1469  return S.getLangOpts().AlignedAllocation &&
1470  S.getASTContext().getTypeAlignIfKnown(AllocType) >
1472 }
1473 
1474 /// Select the correct "usual" deallocation function to use from a selection of
1475 /// deallocation functions (either global or class-scope).
1476 static UsualDeallocFnInfo resolveDeallocationOverload(
1477  Sema &S, LookupResult &R, bool WantSize, bool WantAlign,
1478  llvm::SmallVectorImpl<UsualDeallocFnInfo> *BestFns = nullptr) {
1479  UsualDeallocFnInfo Best;
1480 
1481  for (auto I = R.begin(), E = R.end(); I != E; ++I) {
1482  UsualDeallocFnInfo Info(S, I.getPair());
1483  if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) ||
1484  Info.CUDAPref == Sema::CFP_Never)
1485  continue;
1486 
1487  if (!Best) {
1488  Best = Info;
1489  if (BestFns)
1490  BestFns->push_back(Info);
1491  continue;
1492  }
1493 
1494  if (Best.isBetterThan(Info, WantSize, WantAlign))
1495  continue;
1496 
1497  // If more than one preferred function is found, all non-preferred
1498  // functions are eliminated from further consideration.
1499  if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign))
1500  BestFns->clear();
1501 
1502  Best = Info;
1503  if (BestFns)
1504  BestFns->push_back(Info);
1505  }
1506 
1507  return Best;
1508 }
1509 
1510 /// Determine whether a given type is a class for which 'delete[]' would call
1511 /// a member 'operator delete[]' with a 'size_t' parameter. This implies that
1512 /// we need to store the array size (even if the type is
1513 /// trivially-destructible).
1515  QualType allocType) {
1516  const RecordType *record =
1517  allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
1518  if (!record) return false;
1519 
1520  // Try to find an operator delete[] in class scope.
1521 
1522  DeclarationName deleteName =
1523  S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
1524  LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
1525  S.LookupQualifiedName(ops, record->getDecl());
1526 
1527  // We're just doing this for information.
1528  ops.suppressDiagnostics();
1529 
1530  // Very likely: there's no operator delete[].
1531  if (ops.empty()) return false;
1532 
1533  // If it's ambiguous, it should be illegal to call operator delete[]
1534  // on this thing, so it doesn't matter if we allocate extra space or not.
1535  if (ops.isAmbiguous()) return false;
1536 
1537  // C++17 [expr.delete]p10:
1538  // If the deallocation functions have class scope, the one without a
1539  // parameter of type std::size_t is selected.
1540  auto Best = resolveDeallocationOverload(
1541  S, ops, /*WantSize*/false,
1542  /*WantAlign*/hasNewExtendedAlignment(S, allocType));
1543  return Best && Best.HasSizeT;
1544 }
1545 
1546 /// \brief Parsed a C++ 'new' expression (C++ 5.3.4).
1547 ///
1548 /// E.g.:
1549 /// @code new (memory) int[size][4] @endcode
1550 /// or
1551 /// @code ::new Foo(23, "hello") @endcode
1552 ///
1553 /// \param StartLoc The first location of the expression.
1554 /// \param UseGlobal True if 'new' was prefixed with '::'.
1555 /// \param PlacementLParen Opening paren of the placement arguments.
1556 /// \param PlacementArgs Placement new arguments.
1557 /// \param PlacementRParen Closing paren of the placement arguments.
1558 /// \param TypeIdParens If the type is in parens, the source range.
1559 /// \param D The type to be allocated, as well as array dimensions.
1560 /// \param Initializer The initializing expression or initializer-list, or null
1561 /// if there is none.
1562 ExprResult
1563 Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
1564  SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
1565  SourceLocation PlacementRParen, SourceRange TypeIdParens,
1566  Declarator &D, Expr *Initializer) {
1567  Expr *ArraySize = nullptr;
1568  // If the specified type is an array, unwrap it and save the expression.
1569  if (D.getNumTypeObjects() > 0 &&
1571  DeclaratorChunk &Chunk = D.getTypeObject(0);
1572  if (D.getDeclSpec().hasAutoTypeSpec())
1573  return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
1574  << D.getSourceRange());
1575  if (Chunk.Arr.hasStatic)
1576  return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
1577  << D.getSourceRange());
1578  if (!Chunk.Arr.NumElts)
1579  return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
1580  << D.getSourceRange());
1581 
1582  ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
1583  D.DropFirstTypeObject();
1584  }
1585 
1586  // Every dimension shall be of constant size.
1587  if (ArraySize) {
1588  for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
1590  break;
1591 
1593  if (Expr *NumElts = (Expr *)Array.NumElts) {
1594  if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
1595  if (getLangOpts().CPlusPlus14) {
1596  // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
1597  // shall be a converted constant expression (5.19) of type std::size_t
1598  // and shall evaluate to a strictly positive value.
1599  unsigned IntWidth = Context.getTargetInfo().getIntWidth();
1600  assert(IntWidth && "Builtin type of size 0?");
1601  llvm::APSInt Value(IntWidth);
1602  Array.NumElts
1604  CCEK_NewExpr)
1605  .get();
1606  } else {
1607  Array.NumElts
1608  = VerifyIntegerConstantExpression(NumElts, nullptr,
1609  diag::err_new_array_nonconst)
1610  .get();
1611  }
1612  if (!Array.NumElts)
1613  return ExprError();
1614  }
1615  }
1616  }
1617  }
1618 
1619  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
1620  QualType AllocType = TInfo->getType();
1621  if (D.isInvalidType())
1622  return ExprError();
1623 
1624  SourceRange DirectInitRange;
1625  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
1626  DirectInitRange = List->getSourceRange();
1627 
1628  return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal,
1629  PlacementLParen,
1630  PlacementArgs,
1631  PlacementRParen,
1632  TypeIdParens,
1633  AllocType,
1634  TInfo,
1635  ArraySize,
1636  DirectInitRange,
1637  Initializer);
1638 }
1639 
1641  Expr *Init) {
1642  if (!Init)
1643  return true;
1644  if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
1645  return PLE->getNumExprs() == 0;
1646  if (isa<ImplicitValueInitExpr>(Init))
1647  return true;
1648  else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
1649  return !CCE->isListInitialization() &&
1650  CCE->getConstructor()->isDefaultConstructor();
1651  else if (Style == CXXNewExpr::ListInit) {
1652  assert(isa<InitListExpr>(Init) &&
1653  "Shouldn't create list CXXConstructExprs for arrays.");
1654  return true;
1655  }
1656  return false;
1657 }
1658 
1659 // Emit a diagnostic if an aligned allocation/deallocation function that is not
1660 // implemented in the standard library is selected.
1662  SourceLocation Loc, bool IsDelete,
1663  Sema &S) {
1664  if (!S.getLangOpts().AlignedAllocationUnavailable)
1665  return;
1666 
1667  // Return if there is a definition.
1668  if (FD.isDefined())
1669  return;
1670 
1671  bool IsAligned = false;
1672  if (FD.isReplaceableGlobalAllocationFunction(&IsAligned) && IsAligned) {
1673  const llvm::Triple &T = S.getASTContext().getTargetInfo().getTriple();
1674  StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling(
1676 
1677  S.Diag(Loc, diag::warn_aligned_allocation_unavailable)
1678  << IsDelete << FD.getType().getAsString() << OSName
1679  << alignedAllocMinVersion(T.getOS()).getAsString();
1680  S.Diag(Loc, diag::note_silence_unligned_allocation_unavailable);
1681  }
1682 }
1683 
1684 ExprResult
1685 Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
1686  SourceLocation PlacementLParen,
1687  MultiExprArg PlacementArgs,
1688  SourceLocation PlacementRParen,
1689  SourceRange TypeIdParens,
1690  QualType AllocType,
1691  TypeSourceInfo *AllocTypeInfo,
1692  Expr *ArraySize,
1693  SourceRange DirectInitRange,
1694  Expr *Initializer) {
1695  SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
1696  SourceLocation StartLoc = Range.getBegin();
1697 
1699  if (DirectInitRange.isValid()) {
1700  assert(Initializer && "Have parens but no initializer.");
1701  initStyle = CXXNewExpr::CallInit;
1702  } else if (Initializer && isa<InitListExpr>(Initializer))
1703  initStyle = CXXNewExpr::ListInit;
1704  else {
1705  assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||
1706  isa<CXXConstructExpr>(Initializer)) &&
1707  "Initializer expression that cannot have been implicitly created.");
1708  initStyle = CXXNewExpr::NoInit;
1709  }
1710 
1711  Expr **Inits = &Initializer;
1712  unsigned NumInits = Initializer ? 1 : 0;
1713  if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
1714  assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init");
1715  Inits = List->getExprs();
1716  NumInits = List->getNumExprs();
1717  }
1718 
1719  // C++11 [expr.new]p15:
1720  // A new-expression that creates an object of type T initializes that
1721  // object as follows:
1723  // - If the new-initializer is omitted, the object is default-
1724  // initialized (8.5); if no initialization is performed,
1725  // the object has indeterminate value
1726  = initStyle == CXXNewExpr::NoInit
1728  // - Otherwise, the new-initializer is interpreted according to the
1729  // initialization rules of 8.5 for direct-initialization.
1730  : initStyle == CXXNewExpr::ListInit
1733  DirectInitRange.getBegin(),
1734  DirectInitRange.getEnd());
1735 
1736  // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
1737  auto *Deduced = AllocType->getContainedDeducedType();
1738  if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) {
1739  if (ArraySize)
1740  return ExprError(Diag(ArraySize->getExprLoc(),
1741  diag::err_deduced_class_template_compound_type)
1742  << /*array*/ 2 << ArraySize->getSourceRange());
1743 
1744  InitializedEntity Entity
1745  = InitializedEntity::InitializeNew(StartLoc, AllocType);
1747  AllocTypeInfo, Entity, Kind, MultiExprArg(Inits, NumInits));
1748  if (AllocType.isNull())
1749  return ExprError();
1750  } else if (Deduced) {
1751  if (initStyle == CXXNewExpr::NoInit || NumInits == 0)
1752  return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
1753  << AllocType << TypeRange);
1754  if (initStyle == CXXNewExpr::ListInit ||
1755  (NumInits == 1 && isa<InitListExpr>(Inits[0])))
1756  return ExprError(Diag(Inits[0]->getLocStart(),
1757  diag::err_auto_new_list_init)
1758  << AllocType << TypeRange);
1759  if (NumInits > 1) {
1760  Expr *FirstBad = Inits[1];
1761  return ExprError(Diag(FirstBad->getLocStart(),
1762  diag::err_auto_new_ctor_multiple_expressions)
1763  << AllocType << TypeRange);
1764  }
1765  Expr *Deduce = Inits[0];
1767  if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed)
1768  return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
1769  << AllocType << Deduce->getType()
1770  << TypeRange << Deduce->getSourceRange());
1771  if (DeducedType.isNull())
1772  return ExprError();
1773  AllocType = DeducedType;
1774  }
1775 
1776  // Per C++0x [expr.new]p5, the type being constructed may be a
1777  // typedef of an array type.
1778  if (!ArraySize) {
1779  if (const ConstantArrayType *Array
1780  = Context.getAsConstantArrayType(AllocType)) {
1781  ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
1782  Context.getSizeType(),
1783  TypeRange.getEnd());
1784  AllocType = Array->getElementType();
1785  }
1786  }
1787 
1788  if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
1789  return ExprError();
1790 
1791  if (initStyle == CXXNewExpr::ListInit &&
1792  isStdInitializerList(AllocType, nullptr)) {
1793  Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(),
1794  diag::warn_dangling_std_initializer_list)
1795  << /*at end of FE*/0 << Inits[0]->getSourceRange();
1796  }
1797 
1798  // In ARC, infer 'retaining' for the allocated
1799  if (getLangOpts().ObjCAutoRefCount &&
1800  AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
1801  AllocType->isObjCLifetimeType()) {
1802  AllocType = Context.getLifetimeQualifiedType(AllocType,
1803  AllocType->getObjCARCImplicitLifetime());
1804  }
1805 
1806  QualType ResultType = Context.getPointerType(AllocType);
1807 
1808  if (ArraySize && ArraySize->getType()->isNonOverloadPlaceholderType()) {
1809  ExprResult result = CheckPlaceholderExpr(ArraySize);
1810  if (result.isInvalid()) return ExprError();
1811  ArraySize = result.get();
1812  }
1813  // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
1814  // integral or enumeration type with a non-negative value."
1815  // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
1816  // enumeration type, or a class type for which a single non-explicit
1817  // conversion function to integral or unscoped enumeration type exists.
1818  // C++1y [expr.new]p6: The expression [...] is implicitly converted to
1819  // std::size_t.
1820  llvm::Optional<uint64_t> KnownArraySize;
1821  if (ArraySize && !ArraySize->isTypeDependent()) {
1822  ExprResult ConvertedSize;
1823  if (getLangOpts().CPlusPlus14) {
1824  assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?");
1825 
1826  ConvertedSize = PerformImplicitConversion(ArraySize, Context.getSizeType(),
1827  AA_Converting);
1828 
1829  if (!ConvertedSize.isInvalid() &&
1830  ArraySize->getType()->getAs<RecordType>())
1831  // Diagnose the compatibility of this conversion.
1832  Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
1833  << ArraySize->getType() << 0 << "'size_t'";
1834  } else {
1835  class SizeConvertDiagnoser : public ICEConvertDiagnoser {
1836  protected:
1837  Expr *ArraySize;
1838 
1839  public:
1840  SizeConvertDiagnoser(Expr *ArraySize)
1841  : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
1842  ArraySize(ArraySize) {}
1843 
1844  SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
1845  QualType T) override {
1846  return S.Diag(Loc, diag::err_array_size_not_integral)
1847  << S.getLangOpts().CPlusPlus11 << T;
1848  }
1849 
1850  SemaDiagnosticBuilder diagnoseIncomplete(
1851  Sema &S, SourceLocation Loc, QualType T) override {
1852  return S.Diag(Loc, diag::err_array_size_incomplete_type)
1853  << T << ArraySize->getSourceRange();
1854  }
1855 
1856  SemaDiagnosticBuilder diagnoseExplicitConv(
1857  Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
1858  return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
1859  }
1860 
1861  SemaDiagnosticBuilder noteExplicitConv(
1862  Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
1863  return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
1864  << ConvTy->isEnumeralType() << ConvTy;
1865  }
1866 
1867  SemaDiagnosticBuilder diagnoseAmbiguous(
1868  Sema &S, SourceLocation Loc, QualType T) override {
1869  return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
1870  }
1871 
1872  SemaDiagnosticBuilder noteAmbiguous(
1873  Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
1874  return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
1875  << ConvTy->isEnumeralType() << ConvTy;
1876  }
1877 
1878  SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
1879  QualType T,
1880  QualType ConvTy) override {
1881  return S.Diag(Loc,
1882  S.getLangOpts().CPlusPlus11
1883  ? diag::warn_cxx98_compat_array_size_conversion
1884  : diag::ext_array_size_conversion)
1885  << T << ConvTy->isEnumeralType() << ConvTy;
1886  }
1887  } SizeDiagnoser(ArraySize);
1888 
1889  ConvertedSize = PerformContextualImplicitConversion(StartLoc, ArraySize,
1890  SizeDiagnoser);
1891  }
1892  if (ConvertedSize.isInvalid())
1893  return ExprError();
1894 
1895  ArraySize = ConvertedSize.get();
1896  QualType SizeType = ArraySize->getType();
1897 
1898  if (!SizeType->isIntegralOrUnscopedEnumerationType())
1899  return ExprError();
1900 
1901  // C++98 [expr.new]p7:
1902  // The expression in a direct-new-declarator shall have integral type
1903  // with a non-negative value.
1904  //
1905  // Let's see if this is a constant < 0. If so, we reject it out of hand,
1906  // per CWG1464. Otherwise, if it's not a constant, we must have an
1907  // unparenthesized array type.
1908  if (!ArraySize->isValueDependent()) {
1909  llvm::APSInt Value;
1910  // We've already performed any required implicit conversion to integer or
1911  // unscoped enumeration type.
1912  // FIXME: Per CWG1464, we are required to check the value prior to
1913  // converting to size_t. This will never find a negative array size in
1914  // C++14 onwards, because Value is always unsigned here!
1915  if (ArraySize->isIntegerConstantExpr(Value, Context)) {
1916  if (Value.isSigned() && Value.isNegative()) {
1917  return ExprError(Diag(ArraySize->getLocStart(),
1918  diag::err_typecheck_negative_array_size)
1919  << ArraySize->getSourceRange());
1920  }
1921 
1922  if (!AllocType->isDependentType()) {
1923  unsigned ActiveSizeBits =
1925  if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
1926  return ExprError(Diag(ArraySize->getLocStart(),
1927  diag::err_array_too_large)
1928  << Value.toString(10)
1929  << ArraySize->getSourceRange());
1930  }
1931 
1932  KnownArraySize = Value.getZExtValue();
1933  } else if (TypeIdParens.isValid()) {
1934  // Can't have dynamic array size when the type-id is in parentheses.
1935  Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst)
1936  << ArraySize->getSourceRange()
1937  << FixItHint::CreateRemoval(TypeIdParens.getBegin())
1938  << FixItHint::CreateRemoval(TypeIdParens.getEnd());
1939 
1940  TypeIdParens = SourceRange();
1941  }
1942  }
1943 
1944  // Note that we do *not* convert the argument in any way. It can
1945  // be signed, larger than size_t, whatever.
1946  }
1947 
1948  FunctionDecl *OperatorNew = nullptr;
1949  FunctionDecl *OperatorDelete = nullptr;
1950  unsigned Alignment =
1951  AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType);
1952  unsigned NewAlignment = Context.getTargetInfo().getNewAlign();
1953  bool PassAlignment = getLangOpts().AlignedAllocation &&
1954  Alignment > NewAlignment;
1955 
1956  if (!AllocType->isDependentType() &&
1957  !Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
1958  FindAllocationFunctions(StartLoc,
1959  SourceRange(PlacementLParen, PlacementRParen),
1960  UseGlobal, AllocType, ArraySize, PassAlignment,
1961  PlacementArgs, OperatorNew, OperatorDelete))
1962  return ExprError();
1963 
1964  // If this is an array allocation, compute whether the usual array
1965  // deallocation function for the type has a size_t parameter.
1966  bool UsualArrayDeleteWantsSize = false;
1967  if (ArraySize && !AllocType->isDependentType())
1968  UsualArrayDeleteWantsSize =
1969  doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);
1970 
1971  SmallVector<Expr *, 8> AllPlaceArgs;
1972  if (OperatorNew) {
1973  const FunctionProtoType *Proto =
1974  OperatorNew->getType()->getAs<FunctionProtoType>();
1975  VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
1977 
1978  // We've already converted the placement args, just fill in any default
1979  // arguments. Skip the first parameter because we don't have a corresponding
1980  // argument. Skip the second parameter too if we're passing in the
1981  // alignment; we've already filled it in.
1982  if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto,
1983  PassAlignment ? 2 : 1, PlacementArgs,
1984  AllPlaceArgs, CallType))
1985  return ExprError();
1986 
1987  if (!AllPlaceArgs.empty())
1988  PlacementArgs = AllPlaceArgs;
1989 
1990  // FIXME: This is wrong: PlacementArgs misses out the first (size) argument.
1991  DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs);
1992 
1993  // FIXME: Missing call to CheckFunctionCall or equivalent
1994 
1995  // Warn if the type is over-aligned and is being allocated by (unaligned)
1996  // global operator new.
1997  if (PlacementArgs.empty() && !PassAlignment &&
1998  (OperatorNew->isImplicit() ||
1999  (OperatorNew->getLocStart().isValid() &&
2000  getSourceManager().isInSystemHeader(OperatorNew->getLocStart())))) {
2001  if (Alignment > NewAlignment)
2002  Diag(StartLoc, diag::warn_overaligned_type)
2003  << AllocType
2004  << unsigned(Alignment / Context.getCharWidth())
2005  << unsigned(NewAlignment / Context.getCharWidth());
2006  }
2007  }
2008 
2009  // Array 'new' can't have any initializers except empty parentheses.
2010  // Initializer lists are also allowed, in C++11. Rely on the parser for the
2011  // dialect distinction.
2012  if (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) {
2013  SourceRange InitRange(Inits[0]->getLocStart(),
2014  Inits[NumInits - 1]->getLocEnd());
2015  Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
2016  return ExprError();
2017  }
2018 
2019  // If we can perform the initialization, and we've not already done so,
2020  // do it now.
2021  if (!AllocType->isDependentType() &&
2023  llvm::makeArrayRef(Inits, NumInits))) {
2024  // The type we initialize is the complete type, including the array bound.
2025  QualType InitType;
2026  if (KnownArraySize)
2027  InitType = Context.getConstantArrayType(
2028  AllocType, llvm::APInt(Context.getTypeSize(Context.getSizeType()),
2029  *KnownArraySize),
2030  ArrayType::Normal, 0);
2031  else if (ArraySize)
2032  InitType =
2034  else
2035  InitType = AllocType;
2036 
2037  InitializedEntity Entity
2038  = InitializedEntity::InitializeNew(StartLoc, InitType);
2039  InitializationSequence InitSeq(*this, Entity, Kind,
2040  MultiExprArg(Inits, NumInits));
2041  ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind,
2042  MultiExprArg(Inits, NumInits));
2043  if (FullInit.isInvalid())
2044  return ExprError();
2045 
2046  // FullInit is our initializer; strip off CXXBindTemporaryExprs, because
2047  // we don't want the initialized object to be destructed.
2048  // FIXME: We should not create these in the first place.
2049  if (CXXBindTemporaryExpr *Binder =
2050  dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
2051  FullInit = Binder->getSubExpr();
2052 
2053  Initializer = FullInit.get();
2054  }
2055 
2056  // Mark the new and delete operators as referenced.
2057  if (OperatorNew) {
2058  if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
2059  return ExprError();
2060  MarkFunctionReferenced(StartLoc, OperatorNew);
2061  diagnoseUnavailableAlignedAllocation(*OperatorNew, StartLoc, false, *this);
2062  }
2063  if (OperatorDelete) {
2064  if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
2065  return ExprError();
2066  MarkFunctionReferenced(StartLoc, OperatorDelete);
2067  diagnoseUnavailableAlignedAllocation(*OperatorDelete, StartLoc, true, *this);
2068  }
2069 
2070  // C++0x [expr.new]p17:
2071  // If the new expression creates an array of objects of class type,
2072  // access and ambiguity control are done for the destructor.
2073  QualType BaseAllocType = Context.getBaseElementType(AllocType);
2074  if (ArraySize && !BaseAllocType->isDependentType()) {
2075  if (const RecordType *BaseRecordType = BaseAllocType->getAs<RecordType>()) {
2076  if (CXXDestructorDecl *dtor = LookupDestructor(
2077  cast<CXXRecordDecl>(BaseRecordType->getDecl()))) {
2078  MarkFunctionReferenced(StartLoc, dtor);
2079  CheckDestructorAccess(StartLoc, dtor,
2080  PDiag(diag::err_access_dtor)
2081  << BaseAllocType);
2082  if (DiagnoseUseOfDecl(dtor, StartLoc))
2083  return ExprError();
2084  }
2085  }
2086  }
2087 
2088  return new (Context)
2089  CXXNewExpr(Context, UseGlobal, OperatorNew, OperatorDelete, PassAlignment,
2090  UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens,
2091  ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo,
2092  Range, DirectInitRange);
2093 }
2094 
2095 /// \brief Checks that a type is suitable as the allocated type
2096 /// in a new-expression.
2098  SourceRange R) {
2099  // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
2100  // abstract class type or array thereof.
2101  if (AllocType->isFunctionType())
2102  return Diag(Loc, diag::err_bad_new_type)
2103  << AllocType << 0 << R;
2104  else if (AllocType->isReferenceType())
2105  return Diag(Loc, diag::err_bad_new_type)
2106  << AllocType << 1 << R;
2107  else if (!AllocType->isDependentType() &&
2108  RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R))
2109  return true;
2110  else if (RequireNonAbstractType(Loc, AllocType,
2111  diag::err_allocation_of_abstract_type))
2112  return true;
2113  else if (AllocType->isVariablyModifiedType())
2114  return Diag(Loc, diag::err_variably_modified_new_type)
2115  << AllocType;
2116  else if (AllocType.getAddressSpace() != LangAS::Default)
2117  return Diag(Loc, diag::err_address_space_qualified_new)
2118  << AllocType.getUnqualifiedType()
2120  else if (getLangOpts().ObjCAutoRefCount) {
2121  if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
2122  QualType BaseAllocType = Context.getBaseElementType(AT);
2123  if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
2124  BaseAllocType->isObjCLifetimeType())
2125  return Diag(Loc, diag::err_arc_new_array_without_ownership)
2126  << BaseAllocType;
2127  }
2128  }
2129 
2130  return false;
2131 }
2132 
2133 static bool
2135  SmallVectorImpl<Expr *> &Args, bool &PassAlignment,
2136  FunctionDecl *&Operator,
2137  OverloadCandidateSet *AlignedCandidates = nullptr,
2138  Expr *AlignArg = nullptr) {
2139  OverloadCandidateSet Candidates(R.getNameLoc(),
2141  for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
2142  Alloc != AllocEnd; ++Alloc) {
2143  // Even member operator new/delete are implicitly treated as
2144  // static, so don't use AddMemberCandidate.
2145  NamedDecl *D = (*Alloc)->getUnderlyingDecl();
2146 
2147  if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
2148  S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
2149  /*ExplicitTemplateArgs=*/nullptr, Args,
2150  Candidates,
2151  /*SuppressUserConversions=*/false);
2152  continue;
2153  }
2154 
2155  FunctionDecl *Fn = cast<FunctionDecl>(D);
2156  S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
2157  /*SuppressUserConversions=*/false);
2158  }
2159 
2160  // Do the resolution.
2162  switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) {
2163  case OR_Success: {
2164  // Got one!
2165  FunctionDecl *FnDecl = Best->Function;
2166  if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(),
2167  Best->FoundDecl) == Sema::AR_inaccessible)
2168  return true;
2169 
2170  Operator = FnDecl;
2171  return false;
2172  }
2173 
2174  case OR_No_Viable_Function:
2175  // C++17 [expr.new]p13:
2176  // If no matching function is found and the allocated object type has
2177  // new-extended alignment, the alignment argument is removed from the
2178  // argument list, and overload resolution is performed again.
2179  if (PassAlignment) {
2180  PassAlignment = false;
2181  AlignArg = Args[1];
2182  Args.erase(Args.begin() + 1);
2183  return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2184  Operator, &Candidates, AlignArg);
2185  }
2186 
2187  // MSVC will fall back on trying to find a matching global operator new
2188  // if operator new[] cannot be found. Also, MSVC will leak by not
2189  // generating a call to operator delete or operator delete[], but we
2190  // will not replicate that bug.
2191  // FIXME: Find out how this interacts with the std::align_val_t fallback
2192  // once MSVC implements it.
2193  if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New &&
2194  S.Context.getLangOpts().MSVCCompat) {
2195  R.clear();
2198  // FIXME: This will give bad diagnostics pointing at the wrong functions.
2199  return resolveAllocationOverload(S, R, Range, Args, PassAlignment,
2200  Operator, nullptr);
2201  }
2202 
2203  S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call)
2204  << R.getLookupName() << Range;
2205 
2206  // If we have aligned candidates, only note the align_val_t candidates
2207  // from AlignedCandidates and the non-align_val_t candidates from
2208  // Candidates.
2209  if (AlignedCandidates) {
2210  auto IsAligned = [](OverloadCandidate &C) {
2211  return C.Function->getNumParams() > 1 &&
2212  C.Function->getParamDecl(1)->getType()->isAlignValT();
2213  };
2214  auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); };
2215 
2216  // This was an overaligned allocation, so list the aligned candidates
2217  // first.
2218  Args.insert(Args.begin() + 1, AlignArg);
2219  AlignedCandidates->NoteCandidates(S, OCD_AllCandidates, Args, "",
2220  R.getNameLoc(), IsAligned);
2221  Args.erase(Args.begin() + 1);
2222  Candidates.NoteCandidates(S, OCD_AllCandidates, Args, "", R.getNameLoc(),
2223  IsUnaligned);
2224  } else {
2225  Candidates.NoteCandidates(S, OCD_AllCandidates, Args);
2226  }
2227  return true;
2228 
2229  case OR_Ambiguous:
2230  S.Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call)
2231  << R.getLookupName() << Range;
2232  Candidates.NoteCandidates(S, OCD_ViableCandidates, Args);
2233  return true;
2234 
2235  case OR_Deleted: {
2236  S.Diag(R.getNameLoc(), diag::err_ovl_deleted_call)
2237  << Best->Function->isDeleted()
2238  << R.getLookupName()
2239  << S.getDeletedOrUnavailableSuffix(Best->Function)
2240  << Range;
2241  Candidates.NoteCandidates(S, OCD_AllCandidates, Args);
2242  return true;
2243  }
2244  }
2245  llvm_unreachable("Unreachable, bad result from BestViableFunction");
2246 }
2247 
2248 
2249 /// FindAllocationFunctions - Finds the overloads of operator new and delete
2250 /// that are appropriate for the allocation.
2252  bool UseGlobal, QualType AllocType,
2253  bool IsArray, bool &PassAlignment,
2254  MultiExprArg PlaceArgs,
2255  FunctionDecl *&OperatorNew,
2256  FunctionDecl *&OperatorDelete) {
2257  // --- Choosing an allocation function ---
2258  // C++ 5.3.4p8 - 14 & 18
2259  // 1) If UseGlobal is true, only look in the global scope. Else, also look
2260  // in the scope of the allocated class.
2261  // 2) If an array size is given, look for operator new[], else look for
2262  // operator new.
2263  // 3) The first argument is always size_t. Append the arguments from the
2264  // placement form.
2265 
2266  SmallVector<Expr*, 8> AllocArgs;
2267  AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size());
2268 
2269  // We don't care about the actual value of these arguments.
2270  // FIXME: Should the Sema create the expression and embed it in the syntax
2271  // tree? Or should the consumer just recalculate the value?
2272  // FIXME: Using a dummy value will interact poorly with attribute enable_if.
2273  IntegerLiteral Size(Context, llvm::APInt::getNullValue(
2275  Context.getSizeType(),
2276  SourceLocation());
2277  AllocArgs.push_back(&Size);
2278 
2279  QualType AlignValT = Context.VoidTy;
2280  if (PassAlignment) {
2282  AlignValT = Context.getTypeDeclType(getStdAlignValT());
2283  }
2284  CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation());
2285  if (PassAlignment)
2286  AllocArgs.push_back(&Align);
2287 
2288  AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end());
2289 
2290  // C++ [expr.new]p8:
2291  // If the allocated type is a non-array type, the allocation
2292  // function's name is operator new and the deallocation function's
2293  // name is operator delete. If the allocated type is an array
2294  // type, the allocation function's name is operator new[] and the
2295  // deallocation function's name is operator delete[].
2297  IsArray ? OO_Array_New : OO_New);
2298 
2299  QualType AllocElemType = Context.getBaseElementType(AllocType);
2300 
2301  // Find the allocation function.
2302  {
2303  LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName);
2304 
2305  // C++1z [expr.new]p9:
2306  // If the new-expression begins with a unary :: operator, the allocation
2307  // function's name is looked up in the global scope. Otherwise, if the
2308  // allocated type is a class type T or array thereof, the allocation
2309  // function's name is looked up in the scope of T.
2310  if (AllocElemType->isRecordType() && !UseGlobal)
2311  LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl());
2312 
2313  // We can see ambiguity here if the allocation function is found in
2314  // multiple base classes.
2315  if (R.isAmbiguous())
2316  return true;
2317 
2318  // If this lookup fails to find the name, or if the allocated type is not
2319  // a class type, the allocation function's name is looked up in the
2320  // global scope.
2321  if (R.empty())
2323 
2324  assert(!R.empty() && "implicitly declared allocation functions not found");
2325  assert(!R.isAmbiguous() && "global allocation functions are ambiguous");
2326 
2327  // We do our own custom access checks below.
2328  R.suppressDiagnostics();
2329 
2330  if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment,
2331  OperatorNew))
2332  return true;
2333  }
2334 
2335  // We don't need an operator delete if we're running under -fno-exceptions.
2336  if (!getLangOpts().Exceptions) {
2337  OperatorDelete = nullptr;
2338  return false;
2339  }
2340 
2341  // Note, the name of OperatorNew might have been changed from array to
2342  // non-array by resolveAllocationOverload.
2344  OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New
2345  ? OO_Array_Delete
2346  : OO_Delete);
2347 
2348  // C++ [expr.new]p19:
2349  //
2350  // If the new-expression begins with a unary :: operator, the
2351  // deallocation function's name is looked up in the global
2352  // scope. Otherwise, if the allocated type is a class type T or an
2353  // array thereof, the deallocation function's name is looked up in
2354  // the scope of T. If this lookup fails to find the name, or if
2355  // the allocated type is not a class type or array thereof, the
2356  // deallocation function's name is looked up in the global scope.
2357  LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
2358  if (AllocElemType->isRecordType() && !UseGlobal) {
2359  CXXRecordDecl *RD
2360  = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl());
2361  LookupQualifiedName(FoundDelete, RD);
2362  }
2363  if (FoundDelete.isAmbiguous())
2364  return true; // FIXME: clean up expressions?
2365 
2366  bool FoundGlobalDelete = FoundDelete.empty();
2367  if (FoundDelete.empty()) {
2370  }
2371 
2372  FoundDelete.suppressDiagnostics();
2373 
2375 
2376  // Whether we're looking for a placement operator delete is dictated
2377  // by whether we selected a placement operator new, not by whether
2378  // we had explicit placement arguments. This matters for things like
2379  // struct A { void *operator new(size_t, int = 0); ... };
2380  // A *a = new A()
2381  //
2382  // We don't have any definition for what a "placement allocation function"
2383  // is, but we assume it's any allocation function whose
2384  // parameter-declaration-clause is anything other than (size_t).
2385  //
2386  // FIXME: Should (size_t, std::align_val_t) also be considered non-placement?
2387  // This affects whether an exception from the constructor of an overaligned
2388  // type uses the sized or non-sized form of aligned operator delete.
2389  bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 ||
2390  OperatorNew->isVariadic();
2391 
2392  if (isPlacementNew) {
2393  // C++ [expr.new]p20:
2394  // A declaration of a placement deallocation function matches the
2395  // declaration of a placement allocation function if it has the
2396  // same number of parameters and, after parameter transformations
2397  // (8.3.5), all parameter types except the first are
2398  // identical. [...]
2399  //
2400  // To perform this comparison, we compute the function type that
2401  // the deallocation function should have, and use that type both
2402  // for template argument deduction and for comparison purposes.
2403  QualType ExpectedFunctionType;
2404  {
2405  const FunctionProtoType *Proto
2406  = OperatorNew->getType()->getAs<FunctionProtoType>();
2407 
2408  SmallVector<QualType, 4> ArgTypes;
2409  ArgTypes.push_back(Context.VoidPtrTy);
2410  for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
2411  ArgTypes.push_back(Proto->getParamType(I));
2412 
2414  // FIXME: This is not part of the standard's rule.
2415  EPI.Variadic = Proto->isVariadic();
2416 
2417  ExpectedFunctionType
2418  = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
2419  }
2420 
2421  for (LookupResult::iterator D = FoundDelete.begin(),
2422  DEnd = FoundDelete.end();
2423  D != DEnd; ++D) {
2424  FunctionDecl *Fn = nullptr;
2425  if (FunctionTemplateDecl *FnTmpl =
2426  dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
2427  // Perform template argument deduction to try to match the
2428  // expected function type.
2429  TemplateDeductionInfo Info(StartLoc);
2430  if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
2431  Info))
2432  continue;
2433  } else
2434  Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());
2435 
2437  ExpectedFunctionType,
2438  /*AdjustExcpetionSpec*/true),
2439  ExpectedFunctionType))
2440  Matches.push_back(std::make_pair(D.getPair(), Fn));
2441  }
2442 
2443  if (getLangOpts().CUDA)
2444  EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches);
2445  } else {
2446  // C++1y [expr.new]p22:
2447  // For a non-placement allocation function, the normal deallocation
2448  // function lookup is used
2449  //
2450  // Per [expr.delete]p10, this lookup prefers a member operator delete
2451  // without a size_t argument, but prefers a non-member operator delete
2452  // with a size_t where possible (which it always is in this case).
2454  UsualDeallocFnInfo Selected = resolveDeallocationOverload(
2455  *this, FoundDelete, /*WantSize*/ FoundGlobalDelete,
2456  /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType),
2457  &BestDeallocFns);
2458  if (Selected)
2459  Matches.push_back(std::make_pair(Selected.Found, Selected.FD));
2460  else {
2461  // If we failed to select an operator, all remaining functions are viable
2462  // but ambiguous.
2463  for (auto Fn : BestDeallocFns)
2464  Matches.push_back(std::make_pair(Fn.Found, Fn.FD));
2465  }
2466  }
2467 
2468  // C++ [expr.new]p20:
2469  // [...] If the lookup finds a single matching deallocation
2470  // function, that function will be called; otherwise, no
2471  // deallocation function will be called.
2472  if (Matches.size() == 1) {
2473  OperatorDelete = Matches[0].second;
2474 
2475  // C++1z [expr.new]p23:
2476  // If the lookup finds a usual deallocation function (3.7.4.2)
2477  // with a parameter of type std::size_t and that function, considered
2478  // as a placement deallocation function, would have been
2479  // selected as a match for the allocation function, the program
2480  // is ill-formed.
2481  if (getLangOpts().CPlusPlus11 && isPlacementNew &&
2482  isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
2483  UsualDeallocFnInfo Info(*this,
2484  DeclAccessPair::make(OperatorDelete, AS_public));
2485  // Core issue, per mail to core reflector, 2016-10-09:
2486  // If this is a member operator delete, and there is a corresponding
2487  // non-sized member operator delete, this isn't /really/ a sized
2488  // deallocation function, it just happens to have a size_t parameter.
2489  bool IsSizedDelete = Info.HasSizeT;
2490  if (IsSizedDelete && !FoundGlobalDelete) {
2491  auto NonSizedDelete =
2492  resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false,
2493  /*WantAlign*/Info.HasAlignValT);
2494  if (NonSizedDelete && !NonSizedDelete.HasSizeT &&
2495  NonSizedDelete.HasAlignValT == Info.HasAlignValT)
2496  IsSizedDelete = false;
2497  }
2498 
2499  if (IsSizedDelete) {
2500  SourceRange R = PlaceArgs.empty()
2501  ? SourceRange()
2502  : SourceRange(PlaceArgs.front()->getLocStart(),
2503  PlaceArgs.back()->getLocEnd());
2504  Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R;
2505  if (!OperatorDelete->isImplicit())
2506  Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
2507  << DeleteName;
2508  }
2509  }
2510 
2511  CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
2512  Matches[0].first);
2513  } else if (!Matches.empty()) {
2514  // We found multiple suitable operators. Per [expr.new]p20, that means we
2515  // call no 'operator delete' function, but we should at least warn the user.
2516  // FIXME: Suppress this warning if the construction cannot throw.
2517  Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found)
2518  << DeleteName << AllocElemType;
2519 
2520  for (auto &Match : Matches)
2521  Diag(Match.second->getLocation(),
2522  diag::note_member_declared_here) << DeleteName;
2523  }
2524 
2525  return false;
2526 }
2527 
2528 /// DeclareGlobalNewDelete - Declare the global forms of operator new and
2529 /// delete. These are:
2530 /// @code
2531 /// // C++03:
2532 /// void* operator new(std::size_t) throw(std::bad_alloc);
2533 /// void* operator new[](std::size_t) throw(std::bad_alloc);
2534 /// void operator delete(void *) throw();
2535 /// void operator delete[](void *) throw();
2536 /// // C++11:
2537 /// void* operator new(std::size_t);
2538 /// void* operator new[](std::size_t);
2539 /// void operator delete(void *) noexcept;
2540 /// void operator delete[](void *) noexcept;
2541 /// // C++1y:
2542 /// void* operator new(std::size_t);
2543 /// void* operator new[](std::size_t);
2544 /// void operator delete(void *) noexcept;
2545 /// void operator delete[](void *) noexcept;
2546 /// void operator delete(void *, std::size_t) noexcept;
2547 /// void operator delete[](void *, std::size_t) noexcept;
2548 /// @endcode
2549 /// Note that the placement and nothrow forms of new are *not* implicitly
2550 /// declared. Their use requires including <new>.
2553  return;
2554 
2555  // C++ [basic.std.dynamic]p2:
2556  // [...] The following allocation and deallocation functions (18.4) are
2557  // implicitly declared in global scope in each translation unit of a
2558  // program
2559  //
2560  // C++03:
2561  // void* operator new(std::size_t) throw(std::bad_alloc);
2562  // void* operator new[](std::size_t) throw(std::bad_alloc);
2563  // void operator delete(void*) throw();
2564  // void operator delete[](void*) throw();
2565  // C++11:
2566  // void* operator new(std::size_t);
2567  // void* operator new[](std::size_t);
2568  // void operator delete(void*) noexcept;
2569  // void operator delete[](void*) noexcept;
2570  // C++1y:
2571  // void* operator new(std::size_t);
2572  // void* operator new[](std::size_t);
2573  // void operator delete(void*) noexcept;
2574  // void operator delete[](void*) noexcept;
2575  // void operator delete(void*, std::size_t) noexcept;
2576  // void operator delete[](void*, std::size_t) noexcept;
2577  //
2578  // These implicit declarations introduce only the function names operator
2579  // new, operator new[], operator delete, operator delete[].
2580  //
2581  // Here, we need to refer to std::bad_alloc, so we will implicitly declare
2582  // "std" or "bad_alloc" as necessary to form the exception specification.
2583  // However, we do not make these implicit declarations visible to name
2584  // lookup.
2585  if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
2586  // The "std::bad_alloc" class has not yet been declared, so build it
2587  // implicitly.
2591  &PP.getIdentifierTable().get("bad_alloc"),
2592  nullptr);
2593  getStdBadAlloc()->setImplicit(true);
2594  }
2595  if (!StdAlignValT && getLangOpts().AlignedAllocation) {
2596  // The "std::align_val_t" enum class has not yet been declared, so build it
2597  // implicitly.
2598  auto *AlignValT = EnumDecl::Create(
2600  &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true);
2601  AlignValT->setIntegerType(Context.getSizeType());
2602  AlignValT->setPromotionType(Context.getSizeType());
2603  AlignValT->setImplicit(true);
2604  StdAlignValT = AlignValT;
2605  }
2606 
2607  GlobalNewDeleteDeclared = true;
2608 
2610  QualType SizeT = Context.getSizeType();
2611 
2612  auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind,
2613  QualType Return, QualType Param) {
2615  Params.push_back(Param);
2616 
2617  // Create up to four variants of the function (sized/aligned).
2618  bool HasSizedVariant = getLangOpts().SizedDeallocation &&
2619  (Kind == OO_Delete || Kind == OO_Array_Delete);
2620  bool HasAlignedVariant = getLangOpts().AlignedAllocation;
2621 
2622  int NumSizeVariants = (HasSizedVariant ? 2 : 1);
2623  int NumAlignVariants = (HasAlignedVariant ? 2 : 1);
2624  for (int Sized = 0; Sized < NumSizeVariants; ++Sized) {
2625  if (Sized)
2626  Params.push_back(SizeT);
2627 
2628  for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) {
2629  if (Aligned)
2630  Params.push_back(Context.getTypeDeclType(getStdAlignValT()));
2631 
2633  Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params);
2634 
2635  if (Aligned)
2636  Params.pop_back();
2637  }
2638  }
2639  };
2640 
2641  DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT);
2642  DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT);
2643  DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr);
2644  DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr);
2645 }
2646 
2647 /// DeclareGlobalAllocationFunction - Declares a single implicit global
2648 /// allocation function if it doesn't already exist.
2650  QualType Return,
2651  ArrayRef<QualType> Params) {
2653 
2654  // Check if this function is already declared.
2655  DeclContext::lookup_result R = GlobalCtx->lookup(Name);
2656  for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
2657  Alloc != AllocEnd; ++Alloc) {
2658  // Only look at non-template functions, as it is the predefined,
2659  // non-templated allocation function we are trying to declare here.
2660  if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
2661  if (Func->getNumParams() == Params.size()) {
2662  llvm::SmallVector<QualType, 3> FuncParams;
2663  for (auto *P : Func->parameters())
2664  FuncParams.push_back(
2665  Context.getCanonicalType(P->getType().getUnqualifiedType()));
2666  if (llvm::makeArrayRef(FuncParams) == Params) {
2667  // Make the function visible to name lookup, even if we found it in
2668  // an unimported module. It either is an implicitly-declared global
2669  // allocation function, or is suppressing that function.
2670  Func->setVisibleDespiteOwningModule();
2671  return;
2672  }
2673  }
2674  }
2675  }
2676 
2678 
2679  QualType BadAllocType;
2680  bool HasBadAllocExceptionSpec
2681  = (Name.getCXXOverloadedOperator() == OO_New ||
2682  Name.getCXXOverloadedOperator() == OO_Array_New);
2683  if (HasBadAllocExceptionSpec) {
2684  if (!getLangOpts().CPlusPlus11) {
2685  BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
2686  assert(StdBadAlloc && "Must have std::bad_alloc declared");
2688  EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
2689  }
2690  } else {
2691  EPI.ExceptionSpec =
2692  getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
2693  }
2694 
2695  auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) {
2696  QualType FnType = Context.getFunctionType(Return, Params, EPI);
2698  Context, GlobalCtx, SourceLocation(), SourceLocation(), Name,
2699  FnType, /*TInfo=*/nullptr, SC_None, false, true);
2700  Alloc->setImplicit();
2701  // Global allocation functions should always be visible.
2703 
2704  // Implicit sized deallocation functions always have default visibility.
2705  Alloc->addAttr(
2706  VisibilityAttr::CreateImplicit(Context, VisibilityAttr::Default));
2707 
2709  for (QualType T : Params) {
2710  ParamDecls.push_back(ParmVarDecl::Create(
2711  Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T,
2712  /*TInfo=*/nullptr, SC_None, nullptr));
2713  ParamDecls.back()->setImplicit();
2714  }
2715  Alloc->setParams(ParamDecls);
2716  if (ExtraAttr)
2717  Alloc->addAttr(ExtraAttr);
2719  IdResolver.tryAddTopLevelDecl(Alloc, Name);
2720  };
2721 
2722  if (!LangOpts.CUDA)
2723  CreateAllocationFunctionDecl(nullptr);
2724  else {
2725  // Host and device get their own declaration so each can be
2726  // defined or re-declared independently.
2727  CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context));
2728  CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context));
2729  }
2730 }
2731 
2733  bool CanProvideSize,
2734  bool Overaligned,
2735  DeclarationName Name) {
2737 
2738  LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
2740 
2741  // FIXME: It's possible for this to result in ambiguity, through a
2742  // user-declared variadic operator delete or the enable_if attribute. We
2743  // should probably not consider those cases to be usual deallocation
2744  // functions. But for now we just make an arbitrary choice in that case.
2745  auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize,
2746  Overaligned);
2747  assert(Result.FD && "operator delete missing from global scope?");
2748  return Result.FD;
2749 }
2750 
2752  CXXRecordDecl *RD) {
2754 
2755  FunctionDecl *OperatorDelete = nullptr;
2756  if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
2757  return nullptr;
2758  if (OperatorDelete)
2759  return OperatorDelete;
2760 
2761  // If there's no class-specific operator delete, look up the global
2762  // non-array delete.
2764  Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)),
2765  Name);
2766 }
2767 
2769  DeclarationName Name,
2770  FunctionDecl *&Operator, bool Diagnose) {
2771  LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
2772  // Try to find operator delete/operator delete[] in class scope.
2773  LookupQualifiedName(Found, RD);
2774 
2775  if (Found.isAmbiguous())
2776  return true;
2777 
2778  Found.suppressDiagnostics();
2779 
2780  bool Overaligned = hasNewExtendedAlignment(*this, Context.getRecordType(RD));
2781 
2782  // C++17 [expr.delete]p10:
2783  // If the deallocation functions have class scope, the one without a
2784  // parameter of type std::size_t is selected.
2786  resolveDeallocationOverload(*this, Found, /*WantSize*/ false,
2787  /*WantAlign*/ Overaligned, &Matches);
2788 
2789  // If we could find an overload, use it.
2790  if (Matches.size() == 1) {
2791  Operator = cast<CXXMethodDecl>(Matches[0].FD);
2792 
2793  // FIXME: DiagnoseUseOfDecl?
2794  if (Operator->isDeleted()) {
2795  if (Diagnose) {
2796  Diag(StartLoc, diag::err_deleted_function_use);
2797  NoteDeletedFunction(Operator);
2798  }
2799  return true;
2800  }
2801 
2802  if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
2803  Matches[0].Found, Diagnose) == AR_inaccessible)
2804  return true;
2805 
2806  return false;
2807  }
2808 
2809  // We found multiple suitable operators; complain about the ambiguity.
2810  // FIXME: The standard doesn't say to do this; it appears that the intent
2811  // is that this should never happen.
2812  if (!Matches.empty()) {
2813  if (Diagnose) {
2814  Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
2815  << Name << RD;
2816  for (auto &Match : Matches)
2817  Diag(Match.FD->getLocation(), diag::note_member_declared_here) << Name;
2818  }
2819  return true;
2820  }
2821 
2822  // We did find operator delete/operator delete[] declarations, but
2823  // none of them were suitable.
2824  if (!Found.empty()) {
2825  if (Diagnose) {
2826  Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
2827  << Name << RD;
2828 
2829  for (NamedDecl *D : Found)
2830  Diag(D->getUnderlyingDecl()->getLocation(),
2831  diag::note_member_declared_here) << Name;
2832  }
2833  return true;
2834  }
2835 
2836  Operator = nullptr;
2837  return false;
2838 }
2839 
2840 namespace {
2841 /// \brief Checks whether delete-expression, and new-expression used for
2842 /// initializing deletee have the same array form.
2843 class MismatchingNewDeleteDetector {
2844 public:
2845  enum MismatchResult {
2846  /// Indicates that there is no mismatch or a mismatch cannot be proven.
2847  NoMismatch,
2848  /// Indicates that variable is initialized with mismatching form of \a new.
2849  VarInitMismatches,
2850  /// Indicates that member is initialized with mismatching form of \a new.
2851  MemberInitMismatches,
2852  /// Indicates that 1 or more constructors' definitions could not been
2853  /// analyzed, and they will be checked again at the end of translation unit.
2854  AnalyzeLater
2855  };
2856 
2857  /// \param EndOfTU True, if this is the final analysis at the end of
2858  /// translation unit. False, if this is the initial analysis at the point
2859  /// delete-expression was encountered.
2860  explicit MismatchingNewDeleteDetector(bool EndOfTU)
2861  : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU),
2862  HasUndefinedConstructors(false) {}
2863 
2864  /// \brief Checks whether pointee of a delete-expression is initialized with
2865  /// matching form of new-expression.
2866  ///
2867  /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the
2868  /// point where delete-expression is encountered, then a warning will be
2869  /// issued immediately. If return value is \c AnalyzeLater at the point where
2870  /// delete-expression is seen, then member will be analyzed at the end of
2871  /// translation unit. \c AnalyzeLater is returned iff at least one constructor
2872  /// couldn't be analyzed. If at least one constructor initializes the member
2873  /// with matching type of new, the return value is \c NoMismatch.
2874  MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE);
2875  /// \brief Analyzes a class member.
2876  /// \param Field Class member to analyze.
2877  /// \param DeleteWasArrayForm Array form-ness of the delete-expression used
2878  /// for deleting the \p Field.
2879  MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm);
2880  FieldDecl *Field;
2881  /// List of mismatching new-expressions used for initialization of the pointee
2883  /// Indicates whether delete-expression was in array form.
2884  bool IsArrayForm;
2885 
2886 private:
2887  const bool EndOfTU;
2888  /// \brief Indicates that there is at least one constructor without body.
2889  bool HasUndefinedConstructors;
2890  /// \brief Returns \c CXXNewExpr from given initialization expression.
2891  /// \param E Expression used for initializing pointee in delete-expression.
2892  /// E can be a single-element \c InitListExpr consisting of new-expression.
2893  const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E);
2894  /// \brief Returns whether member is initialized with mismatching form of
2895  /// \c new either by the member initializer or in-class initialization.
2896  ///
2897  /// If bodies of all constructors are not visible at the end of translation
2898  /// unit or at least one constructor initializes member with the matching
2899  /// form of \c new, mismatch cannot be proven, and this function will return
2900  /// \c NoMismatch.
2901  MismatchResult analyzeMemberExpr(const MemberExpr *ME);
2902  /// \brief Returns whether variable is initialized with mismatching form of
2903  /// \c new.
2904  ///
2905  /// If variable is initialized with matching form of \c new or variable is not
2906  /// initialized with a \c new expression, this function will return true.
2907  /// If variable is initialized with mismatching form of \c new, returns false.
2908  /// \param D Variable to analyze.
2909  bool hasMatchingVarInit(const DeclRefExpr *D);
2910  /// \brief Checks whether the constructor initializes pointee with mismatching
2911  /// form of \c new.
2912  ///
2913  /// Returns true, if member is initialized with matching form of \c new in
2914  /// member initializer list. Returns false, if member is initialized with the
2915  /// matching form of \c new in this constructor's initializer or given
2916  /// constructor isn't defined at the point where delete-expression is seen, or
2917  /// member isn't initialized by the constructor.
2918  bool hasMatchingNewInCtor(const CXXConstructorDecl *CD);
2919  /// \brief Checks whether member is initialized with matching form of
2920  /// \c new in member initializer list.
2921  bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI);
2922  /// Checks whether member is initialized with mismatching form of \c new by
2923  /// in-class initializer.
2924  MismatchResult analyzeInClassInitializer();
2925 };
2926 }
2927 
2928 MismatchingNewDeleteDetector::MismatchResult
2929 MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) {
2930  NewExprs.clear();
2931  assert(DE && "Expected delete-expression");
2932  IsArrayForm = DE->isArrayForm();
2933  const Expr *E = DE->getArgument()->IgnoreParenImpCasts();
2934  if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) {
2935  return analyzeMemberExpr(ME);
2936  } else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) {
2937  if (!hasMatchingVarInit(D))
2938  return VarInitMismatches;
2939  }
2940  return NoMismatch;
2941 }
2942 
2943 const CXXNewExpr *
2944 MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) {
2945  assert(E != nullptr && "Expected a valid initializer expression");
2946  E = E->IgnoreParenImpCasts();
2947  if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) {
2948  if (ILE->getNumInits() == 1)
2949  E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts());
2950  }
2951 
2952  return dyn_cast_or_null<const CXXNewExpr>(E);
2953 }
2954 
2955 bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit(
2956  const CXXCtorInitializer *CI) {
2957  const CXXNewExpr *NE = nullptr;
2958  if (Field == CI->getMember() &&
2959  (NE = getNewExprFromInitListOrExpr(CI->getInit()))) {
2960  if (NE->isArray() == IsArrayForm)
2961  return true;
2962  else
2963  NewExprs.push_back(NE);
2964  }
2965  return false;
2966 }
2967 
2968 bool MismatchingNewDeleteDetector::hasMatchingNewInCtor(
2969  const CXXConstructorDecl *CD) {
2970  if (CD->isImplicit())
2971  return false;
2972  const FunctionDecl *Definition = CD;
2973  if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) {
2974  HasUndefinedConstructors = true;
2975  return EndOfTU;
2976  }
2977  for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) {
2978  if (hasMatchingNewInCtorInit(CI))
2979  return true;
2980  }
2981  return false;
2982 }
2983 
2984 MismatchingNewDeleteDetector::MismatchResult
2985 MismatchingNewDeleteDetector::analyzeInClassInitializer() {
2986  assert(Field != nullptr && "This should be called only for members");
2987  const Expr *InitExpr = Field->getInClassInitializer();
2988  if (!InitExpr)
2989  return EndOfTU ? NoMismatch : AnalyzeLater;
2990  if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) {
2991  if (NE->isArray() != IsArrayForm) {
2992  NewExprs.push_back(NE);
2993  return MemberInitMismatches;
2994  }
2995  }
2996  return NoMismatch;
2997 }
2998 
2999 MismatchingNewDeleteDetector::MismatchResult
3000 MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field,
3001  bool DeleteWasArrayForm) {
3002  assert(Field != nullptr && "Analysis requires a valid class member.");
3003  this->Field = Field;
3004  IsArrayForm = DeleteWasArrayForm;
3005  const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent());
3006  for (const auto *CD : RD->ctors()) {
3007  if (hasMatchingNewInCtor(CD))
3008  return NoMismatch;
3009  }
3010  if (HasUndefinedConstructors)
3011  return EndOfTU ? NoMismatch : AnalyzeLater;
3012  if (!NewExprs.empty())
3013  return MemberInitMismatches;
3014  return Field->hasInClassInitializer() ? analyzeInClassInitializer()
3015  : NoMismatch;
3016 }
3017 
3018 MismatchingNewDeleteDetector::MismatchResult
3019 MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) {
3020  assert(ME != nullptr && "Expected a member expression");
3021  if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3022  return analyzeField(F, IsArrayForm);
3023  return NoMismatch;
3024 }
3025 
3026 bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) {
3027  const CXXNewExpr *NE = nullptr;
3028  if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) {
3029  if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) &&
3030  NE->isArray() != IsArrayForm) {
3031  NewExprs.push_back(NE);
3032  }
3033  }
3034  return NewExprs.empty();
3035 }
3036 
3037 static void
3039  const MismatchingNewDeleteDetector &Detector) {
3040  SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc);
3041  FixItHint H;
3042  if (!Detector.IsArrayForm)
3043  H = FixItHint::CreateInsertion(EndOfDelete, "[]");
3044  else {
3046  DeleteLoc, tok::l_square, SemaRef.getSourceManager(),
3047  SemaRef.getLangOpts(), true);
3048  if (RSquare.isValid())
3049  H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare));
3050  }
3051  SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new)
3052  << Detector.IsArrayForm << H;
3053 
3054  for (const auto *NE : Detector.NewExprs)
3055  SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here)
3056  << Detector.IsArrayForm;
3057 }
3058 
3059 void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) {
3060  if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation()))
3061  return;
3062  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false);
3063  switch (Detector.analyzeDeleteExpr(DE)) {
3064  case MismatchingNewDeleteDetector::VarInitMismatches:
3065  case MismatchingNewDeleteDetector::MemberInitMismatches: {
3066  DiagnoseMismatchedNewDelete(*this, DE->getLocStart(), Detector);
3067  break;
3068  }
3069  case MismatchingNewDeleteDetector::AnalyzeLater: {
3070  DeleteExprs[Detector.Field].push_back(
3071  std::make_pair(DE->getLocStart(), DE->isArrayForm()));
3072  break;
3073  }
3074  case MismatchingNewDeleteDetector::NoMismatch:
3075  break;
3076  }
3077 }
3078 
3079 void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
3080  bool DeleteWasArrayForm) {
3081  MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true);
3082  switch (Detector.analyzeField(Field, DeleteWasArrayForm)) {
3083  case MismatchingNewDeleteDetector::VarInitMismatches:
3084  llvm_unreachable("This analysis should have been done for class members.");
3085  case MismatchingNewDeleteDetector::AnalyzeLater:
3086  llvm_unreachable("Analysis cannot be postponed any point beyond end of "
3087  "translation unit.");
3088  case MismatchingNewDeleteDetector::MemberInitMismatches:
3089  DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector);
3090  break;
3091  case MismatchingNewDeleteDetector::NoMismatch:
3092  break;
3093  }
3094 }
3095 
3096 /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
3097 /// @code ::delete ptr; @endcode
3098 /// or
3099 /// @code delete [] ptr; @endcode
3100 ExprResult
3101 Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
3102  bool ArrayForm, Expr *ExE) {
3103  // C++ [expr.delete]p1:
3104  // The operand shall have a pointer type, or a class type having a single
3105  // non-explicit conversion function to a pointer type. The result has type
3106  // void.
3107  //
3108  // DR599 amends "pointer type" to "pointer to object type" in both cases.
3109 
3110  ExprResult Ex = ExE;
3111  FunctionDecl *OperatorDelete = nullptr;
3112  bool ArrayFormAsWritten = ArrayForm;
3113  bool UsualArrayDeleteWantsSize = false;
3114 
3115  if (!Ex.get()->isTypeDependent()) {
3116  // Perform lvalue-to-rvalue cast, if needed.
3117  Ex = DefaultLvalueConversion(Ex.get());
3118  if (Ex.isInvalid())
3119  return ExprError();
3120 
3121  QualType Type = Ex.get()->getType();
3122 
3123  class DeleteConverter : public ContextualImplicitConverter {
3124  public:
3125  DeleteConverter() : ContextualImplicitConverter(false, true) {}
3126 
3127  bool match(QualType ConvType) override {
3128  // FIXME: If we have an operator T* and an operator void*, we must pick
3129  // the operator T*.
3130  if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
3131  if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
3132  return true;
3133  return false;
3134  }
3135 
3136  SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
3137  QualType T) override {
3138  return S.Diag(Loc, diag::err_delete_operand) << T;
3139  }
3140 
3141  SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
3142  QualType T) override {
3143  return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
3144  }
3145 
3146  SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
3147  QualType T,
3148  QualType ConvTy) override {
3149  return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
3150  }
3151 
3152  SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
3153  QualType ConvTy) override {
3154  return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3155  << ConvTy;
3156  }
3157 
3158  SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
3159  QualType T) override {
3160  return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
3161  }
3162 
3163  SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
3164  QualType ConvTy) override {
3165  return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
3166  << ConvTy;
3167  }
3168 
3169  SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
3170  QualType T,
3171  QualType ConvTy) override {
3172  llvm_unreachable("conversion functions are permitted");
3173  }
3174  } Converter;
3175 
3176  Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
3177  if (Ex.isInvalid())
3178  return ExprError();
3179  Type = Ex.get()->getType();
3180  if (!Converter.match(Type))
3181  // FIXME: PerformContextualImplicitConversion should return ExprError
3182  // itself in this case.
3183  return ExprError();
3184 
3185  QualType Pointee = Type->getAs<PointerType>()->getPointeeType();
3186  QualType PointeeElem = Context.getBaseElementType(Pointee);
3187 
3188  if (Pointee.getAddressSpace() != LangAS::Default)
3189  return Diag(Ex.get()->getLocStart(),
3190  diag::err_address_space_qualified_delete)
3191  << Pointee.getUnqualifiedType()
3193 
3194  CXXRecordDecl *PointeeRD = nullptr;
3195  if (Pointee->isVoidType() && !isSFINAEContext()) {
3196  // The C++ standard bans deleting a pointer to a non-object type, which
3197  // effectively bans deletion of "void*". However, most compilers support
3198  // this, so we treat it as a warning unless we're in a SFINAE context.
3199  Diag(StartLoc, diag::ext_delete_void_ptr_operand)
3200  << Type << Ex.get()->getSourceRange();
3201  } else if (Pointee->isFunctionType() || Pointee->isVoidType()) {
3202  return ExprError(Diag(StartLoc, diag::err_delete_operand)
3203  << Type << Ex.get()->getSourceRange());
3204  } else if (!Pointee->isDependentType()) {
3205  // FIXME: This can result in errors if the definition was imported from a
3206  // module but is hidden.
3207  if (!RequireCompleteType(StartLoc, Pointee,
3208  diag::warn_delete_incomplete, Ex.get())) {
3209  if (const RecordType *RT = PointeeElem->getAs<RecordType>())
3210  PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
3211  }
3212  }
3213 
3214  if (Pointee->isArrayType() && !ArrayForm) {
3215  Diag(StartLoc, diag::warn_delete_array_type)
3216  << Type << Ex.get()->getSourceRange()
3217  << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]");
3218  ArrayForm = true;
3219  }
3220 
3222  ArrayForm ? OO_Array_Delete : OO_Delete);
3223 
3224  if (PointeeRD) {
3225  if (!UseGlobal &&
3226  FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
3227  OperatorDelete))
3228  return ExprError();
3229 
3230  // If we're allocating an array of records, check whether the
3231  // usual operator delete[] has a size_t parameter.
3232  if (ArrayForm) {
3233  // If the user specifically asked to use the global allocator,
3234  // we'll need to do the lookup into the class.
3235  if (UseGlobal)
3236  UsualArrayDeleteWantsSize =
3237  doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);
3238 
3239  // Otherwise, the usual operator delete[] should be the
3240  // function we just found.
3241  else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
3242  UsualArrayDeleteWantsSize =
3243  UsualDeallocFnInfo(*this,
3244  DeclAccessPair::make(OperatorDelete, AS_public))
3245  .HasSizeT;
3246  }
3247 
3248  if (!PointeeRD->hasIrrelevantDestructor())
3249  if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3250  MarkFunctionReferenced(StartLoc,
3251  const_cast<CXXDestructorDecl*>(Dtor));
3252  if (DiagnoseUseOfDecl(Dtor, StartLoc))
3253  return ExprError();
3254  }
3255 
3256  CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc,
3257  /*IsDelete=*/true, /*CallCanBeVirtual=*/true,
3258  /*WarnOnNonAbstractTypes=*/!ArrayForm,
3259  SourceLocation());
3260  }
3261 
3262  if (!OperatorDelete) {
3263  bool IsComplete = isCompleteType(StartLoc, Pointee);
3264  bool CanProvideSize =
3265  IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize ||
3266  Pointee.isDestructedType());
3267  bool Overaligned = hasNewExtendedAlignment(*this, Pointee);
3268 
3269  // Look for a global declaration.
3270  OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize,
3271  Overaligned, DeleteName);
3272  }
3273 
3274  MarkFunctionReferenced(StartLoc, OperatorDelete);
3275 
3276  // Check access and ambiguity of destructor if we're going to call it.
3277  // Note that this is required even for a virtual delete.
3278  bool IsVirtualDelete = false;
3279  if (PointeeRD) {
3280  if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
3281  CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
3282  PDiag(diag::err_access_dtor) << PointeeElem);
3283  IsVirtualDelete = Dtor->isVirtual();
3284  }
3285  }
3286 
3287  diagnoseUnavailableAlignedAllocation(*OperatorDelete, StartLoc, true,
3288  *this);
3289 
3290  // Convert the operand to the type of the first parameter of operator
3291  // delete. This is only necessary if we selected a destroying operator
3292  // delete that we are going to call (non-virtually); converting to void*
3293  // is trivial and left to AST consumers to handle.
3294  QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
3295  if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) {
3296  Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing);
3297  if (Ex.isInvalid())
3298  return ExprError();
3299  }
3300  }
3301 
3303  Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
3304  UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
3305  AnalyzeDeleteExprMismatch(Result);
3306  return Result;
3307 }
3308 
3310  bool IsDelete, bool CallCanBeVirtual,
3311  bool WarnOnNonAbstractTypes,
3312  SourceLocation DtorLoc) {
3313  if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext())
3314  return;
3315 
3316  // C++ [expr.delete]p3:
3317  // In the first alternative (delete object), if the static type of the
3318  // object to be deleted is different from its dynamic type, the static
3319  // type shall be a base class of the dynamic type of the object to be
3320  // deleted and the static type shall have a virtual destructor or the
3321  // behavior is undefined.
3322  //
3323  const CXXRecordDecl *PointeeRD = dtor->getParent();
3324  // Note: a final class cannot be derived from, no issue there
3325  if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>())
3326  return;
3327 
3328  // If the superclass is in a system header, there's nothing that can be done.
3329  // The `delete` (where we emit the warning) can be in a system header,
3330  // what matters for this warning is where the deleted type is defined.
3331  if (getSourceManager().isInSystemHeader(PointeeRD->getLocation()))
3332  return;
3333 
3334  QualType ClassType = dtor->getThisType(Context)->getPointeeType();
3335  if (PointeeRD->isAbstract()) {
3336  // If the class is abstract, we warn by default, because we're
3337  // sure the code has undefined behavior.
3338  Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1)
3339  << ClassType;
3340  } else if (WarnOnNonAbstractTypes) {
3341  // Otherwise, if this is not an array delete, it's a bit suspect,
3342  // but not necessarily wrong.
3343  Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1)
3344  << ClassType;
3345  }
3346  if (!IsDelete) {
3347  std::string TypeStr;
3348  ClassType.getAsStringInternal(TypeStr, getPrintingPolicy());
3349  Diag(DtorLoc, diag::note_delete_non_virtual)
3350  << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::");
3351  }
3352 }
3353 
3355  SourceLocation StmtLoc,
3356  ConditionKind CK) {
3357  ExprResult E =
3358  CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK);
3359  if (E.isInvalid())
3360  return ConditionError();
3361  return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc),
3363 }
3364 
3365 /// \brief Check the use of the given variable as a C++ condition in an if,
3366 /// while, do-while, or switch statement.
3368  SourceLocation StmtLoc,
3369  ConditionKind CK) {
3370  if (ConditionVar->isInvalidDecl())
3371  return ExprError();
3372 
3373  QualType T = ConditionVar->getType();
3374 
3375  // C++ [stmt.select]p2:
3376  // The declarator shall not specify a function or an array.
3377  if (T->isFunctionType())
3378  return ExprError(Diag(ConditionVar->getLocation(),
3379  diag::err_invalid_use_of_function_type)
3380  << ConditionVar->getSourceRange());
3381  else if (T->isArrayType())
3382  return ExprError(Diag(ConditionVar->getLocation(),
3383  diag::err_invalid_use_of_array_type)
3384  << ConditionVar->getSourceRange());
3385 
3386  ExprResult Condition = DeclRefExpr::Create(
3387  Context, NestedNameSpecifierLoc(), SourceLocation(), ConditionVar,
3388  /*enclosing*/ false, ConditionVar->getLocation(),
3389  ConditionVar->getType().getNonReferenceType(), VK_LValue);
3390 
3391  MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get()));
3392 
3393  switch (CK) {
3395  return CheckBooleanCondition(StmtLoc, Condition.get());
3396 
3398  return CheckBooleanCondition(StmtLoc, Condition.get(), true);
3399 
3400  case ConditionKind::Switch:
3401  return CheckSwitchCondition(StmtLoc, Condition.get());
3402  }
3403 
3404  llvm_unreachable("unexpected condition kind");
3405 }
3406 
3407 /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
3408 ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) {
3409  // C++ 6.4p4:
3410  // The value of a condition that is an initialized declaration in a statement
3411  // other than a switch statement is the value of the declared variable
3412  // implicitly converted to type bool. If that conversion is ill-formed, the
3413  // program is ill-formed.
3414  // The value of a condition that is an expression is the value of the
3415  // expression, implicitly converted to bool.
3416  //
3417  // FIXME: Return this value to the caller so they don't need to recompute it.
3418  llvm::APSInt Value(/*BitWidth*/1);
3419  return (IsConstexpr && !CondExpr->isValueDependent())
3420  ? CheckConvertedConstantExpression(CondExpr, Context.BoolTy, Value,
3423 }
3424 
3425 /// Helper function to determine whether this is the (deprecated) C++
3426 /// conversion from a string literal to a pointer to non-const char or
3427 /// non-const wchar_t (for narrow and wide string literals,
3428 /// respectively).
3429 bool
3431  // Look inside the implicit cast, if it exists.
3432  if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
3433  From = Cast->getSubExpr();
3434 
3435  // A string literal (2.13.4) that is not a wide string literal can
3436  // be converted to an rvalue of type "pointer to char"; a wide
3437  // string literal can be converted to an rvalue of type "pointer
3438  // to wchar_t" (C++ 4.2p2).
3439  if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
3440  if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
3441  if (const BuiltinType *ToPointeeType
3442  = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
3443  // This conversion is considered only when there is an
3444  // explicit appropriate pointer target type (C++ 4.2p2).
3445  if (!ToPtrType->getPointeeType().hasQualifiers()) {
3446  switch (StrLit->getKind()) {
3447  case StringLiteral::UTF8:
3448  case StringLiteral::UTF16:
3449  case StringLiteral::UTF32:
3450  // We don't allow UTF literals to be implicitly converted
3451  break;
3452  case StringLiteral::Ascii:
3453  return (ToPointeeType->getKind() == BuiltinType::Char_U ||
3454  ToPointeeType->getKind() == BuiltinType::Char_S);
3455  case StringLiteral::Wide:
3457  QualType(ToPointeeType, 0));
3458  }
3459  }
3460  }
3461 
3462  return false;
3463 }
3464 
3466  SourceLocation CastLoc,
3467  QualType Ty,
3468  CastKind Kind,
3469  CXXMethodDecl *Method,
3470  DeclAccessPair FoundDecl,
3471  bool HadMultipleCandidates,
3472  Expr *From) {
3473  switch (Kind) {
3474  default: llvm_unreachable("Unhandled cast kind!");
3475  case CK_ConstructorConversion: {
3476  CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
3477  SmallVector<Expr*, 8> ConstructorArgs;
3478 
3479  if (S.RequireNonAbstractType(CastLoc, Ty,
3480  diag::err_allocation_of_abstract_type))
3481  return ExprError();
3482 
3483  if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs))
3484  return ExprError();
3485 
3486  S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl,
3488  if (S.DiagnoseUseOfDecl(Method, CastLoc))
3489  return ExprError();
3490 
3492  CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method),
3493  ConstructorArgs, HadMultipleCandidates,
3494  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
3496  if (Result.isInvalid())
3497  return ExprError();
3498 
3499  return S.MaybeBindToTemporary(Result.getAs<Expr>());
3500  }
3501 
3502  case CK_UserDefinedConversion: {
3503  assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");
3504 
3505  S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
3506  if (S.DiagnoseUseOfDecl(Method, CastLoc))
3507  return ExprError();
3508 
3509  // Create an implicit call expr that calls it.
3510  CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
3511  ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
3512  HadMultipleCandidates);
3513  if (Result.isInvalid())
3514  return ExprError();
3515  // Record usage of conversion in an implicit cast.
3516  Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
3517  CK_UserDefinedConversion, Result.get(),
3518  nullptr, Result.get()->getValueKind());
3519 
3520  return S.MaybeBindToTemporary(Result.get());
3521  }
3522  }
3523 }
3524 
3525 /// PerformImplicitConversion - Perform an implicit conversion of the
3526 /// expression From to the type ToType using the pre-computed implicit
3527 /// conversion sequence ICS. Returns the converted
3528 /// expression. Action is the kind of conversion we're performing,
3529 /// used in the error message.
3530 ExprResult
3532  const ImplicitConversionSequence &ICS,
3533  AssignmentAction Action,
3534  CheckedConversionKind CCK) {
3535  switch (ICS.getKind()) {
3537  ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
3538  Action, CCK);
3539  if (Res.isInvalid())
3540  return ExprError();
3541  From = Res.get();
3542  break;
3543  }
3544 
3546 
3549  QualType BeforeToType;
3550  assert(FD && "no conversion function for user-defined conversion seq");
3551  if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
3552  CastKind = CK_UserDefinedConversion;
3553 
3554  // If the user-defined conversion is specified by a conversion function,
3555  // the initial standard conversion sequence converts the source type to
3556  // the implicit object parameter of the conversion function.
3557  BeforeToType = Context.getTagDeclType(Conv->getParent());
3558  } else {
3559  const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
3560  CastKind = CK_ConstructorConversion;
3561  // Do no conversion if dealing with ... for the first conversion.
3562  if (!ICS.UserDefined.EllipsisConversion) {
3563  // If the user-defined conversion is specified by a constructor, the
3564  // initial standard conversion sequence converts the source type to
3565  // the type required by the argument of the constructor
3566  BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
3567  }
3568  }
3569  // Watch out for ellipsis conversion.
3570  if (!ICS.UserDefined.EllipsisConversion) {
3571  ExprResult Res =
3572  PerformImplicitConversion(From, BeforeToType,
3574  CCK);
3575  if (Res.isInvalid())
3576  return ExprError();
3577  From = Res.get();
3578  }
3579 
3580  ExprResult CastArg
3581  = BuildCXXCastArgument(*this,
3582  From->getLocStart(),
3583  ToType.getNonReferenceType(),
3584  CastKind, cast<CXXMethodDecl>(FD),
3587  From);
3588 
3589  if (CastArg.isInvalid())
3590  return ExprError();
3591 
3592  From = CastArg.get();
3593 
3594  return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
3595  AA_Converting, CCK);
3596  }
3597 
3599  ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
3600  PDiag(diag::err_typecheck_ambiguous_condition)
3601  << From->getSourceRange());
3602  return ExprError();
3603 
3605  llvm_unreachable("Cannot perform an ellipsis conversion");
3606 
3608  bool Diagnosed =
3610  From->getType(), From, Action);
3611  assert(Diagnosed && "failed to diagnose bad conversion"); (void)Diagnosed;
3612  return ExprError();
3613  }
3614 
3615  // Everything went well.
3616  return From;
3617 }
3618 
3619 /// PerformImplicitConversion - Perform an implicit conversion of the
3620 /// expression From to the type ToType by following the standard
3621 /// conversion sequence SCS. Returns the converted
3622 /// expression. Flavor is the context in which we're performing this
3623 /// conversion, for use in error messages.
3624 ExprResult
3626  const StandardConversionSequence& SCS,
3627  AssignmentAction Action,
3628  CheckedConversionKind CCK) {
3629  bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);
3630 
3631  // Overall FIXME: we are recomputing too many types here and doing far too
3632  // much extra work. What this means is that we need to keep track of more
3633  // information that is computed when we try the implicit conversion initially,
3634  // so that we don't need to recompute anything here.
3635  QualType FromType = From->getType();
3636 
3637  if (SCS.CopyConstructor) {
3638  // FIXME: When can ToType be a reference type?
3639  assert(!ToType->isReferenceType());
3640  if (SCS.Second == ICK_Derived_To_Base) {
3641  SmallVector<Expr*, 8> ConstructorArgs;
3642  if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor),
3643  From, /*FIXME:ConstructLoc*/SourceLocation(),
3644  ConstructorArgs))
3645  return ExprError();
3646  return BuildCXXConstructExpr(
3647  /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
3649  ConstructorArgs, /*HadMultipleCandidates*/ false,
3650  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
3652  }
3653  return BuildCXXConstructExpr(
3654  /*FIXME:ConstructLoc*/ SourceLocation(), ToType,
3656  From, /*HadMultipleCandidates*/ false,
3657  /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
3659  }
3660 
3661  // Resolve overloaded function references.
3662  if (Context.hasSameType(FromType, Context.OverloadTy)) {
3663  DeclAccessPair Found;
3665  true, Found);
3666  if (!Fn)
3667  return ExprError();
3668 
3669  if (DiagnoseUseOfDecl(Fn, From->getLocStart()))
3670  return ExprError();
3671 
3672  From = FixOverloadedFunctionReference(From, Found, Fn);
3673  FromType = From->getType();
3674  }
3675 
3676  // If we're converting to an atomic type, first convert to the corresponding
3677  // non-atomic type.
3678  QualType ToAtomicType;
3679  if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
3680  ToAtomicType = ToType;
3681  ToType = ToAtomic->getValueType();
3682  }
3683 
3684  QualType InitialFromType = FromType;
3685  // Perform the first implicit conversion.
3686  switch (SCS.First) {
3687  case ICK_Identity:
3688  if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
3689  FromType = FromAtomic->getValueType().getUnqualifiedType();
3690  From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
3691  From, /*BasePath=*/nullptr, VK_RValue);
3692  }
3693  break;
3694 
3695  case ICK_Lvalue_To_Rvalue: {
3696  assert(From->getObjectKind() != OK_ObjCProperty);
3697  ExprResult FromRes = DefaultLvalueConversion(From);
3698  assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!");
3699  From = FromRes.get();
3700  FromType = From->getType();
3701  break;
3702  }
3703 
3704  case ICK_Array_To_Pointer:
3705  FromType = Context.getArrayDecayedType(FromType);
3706  From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay,
3707  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3708  break;
3709 
3711  FromType = Context.getPointerType(FromType);
3712  From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
3713  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3714  break;
3715 
3716  default:
3717  llvm_unreachable("Improper first standard conversion");
3718  }
3719 
3720  // Perform the second implicit conversion
3721  switch (SCS.Second) {
3722  case ICK_Identity:
3723  // C++ [except.spec]p5:
3724  // [For] assignment to and initialization of pointers to functions,
3725  // pointers to member functions, and references to functions: the
3726  // target entity shall allow at least the exceptions allowed by the
3727  // source value in the assignment or initialization.
3728  switch (Action) {
3729  case AA_Assigning:
3730  case AA_Initializing:
3731  // Note, function argument passing and returning are initialization.
3732  case AA_Passing:
3733  case AA_Returning:
3734  case AA_Sending:
3735  case AA_Passing_CFAudited:
3736  if (CheckExceptionSpecCompatibility(From, ToType))
3737  return ExprError();
3738  break;
3739 
3740  case AA_Casting:
3741  case AA_Converting:
3742  // Casts and implicit conversions are not initialization, so are not
3743  // checked for exception specification mismatches.
3744  break;
3745  }
3746  // Nothing else to do.
3747  break;
3748 
3751  if (ToType->isBooleanType()) {
3752  assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
3753  SCS.Second == ICK_Integral_Promotion &&
3754  "only enums with fixed underlying type can promote to bool");
3755  From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean,
3756  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3757  } else {
3758  From = ImpCastExprToType(From, ToType, CK_IntegralCast,
3759  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3760  }
3761  break;
3762 
3765  From = ImpCastExprToType(From, ToType, CK_FloatingCast,
3766  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3767  break;
3768 
3769  case ICK_Complex_Promotion:
3770  case ICK_Complex_Conversion: {
3771  QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType();
3772  QualType ToEl = ToType->getAs<ComplexType>()->getElementType();
3773  CastKind CK;
3774  if (FromEl->isRealFloatingType()) {
3775  if (ToEl->isRealFloatingType())
3776  CK = CK_FloatingComplexCast;
3777  else
3778  CK = CK_FloatingComplexToIntegralComplex;
3779  } else if (ToEl->isRealFloatingType()) {
3780  CK = CK_IntegralComplexToFloatingComplex;
3781  } else {
3782  CK = CK_IntegralComplexCast;
3783  }
3784  From = ImpCastExprToType(From, ToType, CK,
3785  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3786  break;
3787  }
3788 
3789  case ICK_Floating_Integral:
3790  if (ToType->isRealFloatingType())
3791  From = ImpCastExprToType(From, ToType, CK_IntegralToFloating,
3792  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3793  else
3794  From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral,
3795  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3796  break;
3797 
3799  From = ImpCastExprToType(From, ToType, CK_NoOp,
3800  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3801  break;
3802 
3804  case ICK_Pointer_Conversion: {
3805  if (SCS.IncompatibleObjC && Action != AA_Casting) {
3806  // Diagnose incompatible Objective-C conversions
3807  if (Action == AA_Initializing || Action == AA_Assigning)
3808  Diag(From->getLocStart(),
3809  diag::ext_typecheck_convert_incompatible_pointer)
3810  << ToType << From->getType() << Action
3811  << From->getSourceRange() << 0;
3812  else
3813  Diag(From->getLocStart(),
3814  diag::ext_typecheck_convert_incompatible_pointer)
3815  << From->getType() << ToType << Action
3816  << From->getSourceRange() << 0;
3817 
3818  if (From->getType()->isObjCObjectPointerType() &&
3819  ToType->isObjCObjectPointerType())
3823  From->getType())) {
3824  if (Action == AA_Initializing)
3825  Diag(From->getLocStart(),
3826  diag::err_arc_weak_unavailable_assign);
3827  else
3828  Diag(From->getLocStart(),
3829  diag::err_arc_convesion_of_weak_unavailable)
3830  << (Action == AA_Casting) << From->getType() << ToType
3831  << From->getSourceRange();
3832  }
3833 
3835  CXXCastPath BasePath;
3836  if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle))
3837  return ExprError();
3838 
3839  // Make sure we extend blocks if necessary.
3840  // FIXME: doing this here is really ugly.
3841  if (Kind == CK_BlockPointerToObjCPointerCast) {
3842  ExprResult E = From;
3844  From = E.get();
3845  }
3846  if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers())
3847  CheckObjCConversion(SourceRange(), ToType, From, CCK);
3848  From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
3849  .get();
3850  break;
3851  }
3852 
3853  case ICK_Pointer_Member: {
3855  CXXCastPath BasePath;
3856  if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
3857  return ExprError();
3858  if (CheckExceptionSpecCompatibility(From, ToType))
3859  return ExprError();
3860 
3861  // We may not have been able to figure out what this member pointer resolved
3862  // to up until this exact point. Attempt to lock-in it's inheritance model.
3864  (void)isCompleteType(From->getExprLoc(), From->getType());
3865  (void)isCompleteType(From->getExprLoc(), ToType);
3866  }
3867 
3868  From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
3869  .get();
3870  break;
3871  }
3872 
3874  // Perform half-to-boolean conversion via float.
3875  if (From->getType()->isHalfType()) {
3876  From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
3877  FromType = Context.FloatTy;
3878  }
3879 
3880  From = ImpCastExprToType(From, Context.BoolTy,
3881  ScalarTypeToBooleanCastKind(FromType),
3882  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3883  break;
3884 
3885  case ICK_Derived_To_Base: {
3886  CXXCastPath BasePath;
3888  ToType.getNonReferenceType(),
3889  From->getLocStart(),
3890  From->getSourceRange(),
3891  &BasePath,
3892  CStyle))
3893  return ExprError();
3894 
3895  From = ImpCastExprToType(From, ToType.getNonReferenceType(),
3896  CK_DerivedToBase, From->getValueKind(),
3897  &BasePath, CCK).get();
3898  break;
3899  }
3900 
3901  case ICK_Vector_Conversion:
3902  From = ImpCastExprToType(From, ToType, CK_BitCast,
3903  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3904  break;
3905 
3906  case ICK_Vector_Splat: {
3907  // Vector splat from any arithmetic type to a vector.
3908  Expr *Elem = prepareVectorSplat(ToType, From).get();
3909  From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_RValue,
3910  /*BasePath=*/nullptr, CCK).get();
3911  break;
3912  }
3913 
3914  case ICK_Complex_Real:
3915  // Case 1. x -> _Complex y
3916  if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
3917  QualType ElType = ToComplex->getElementType();
3918  bool isFloatingComplex = ElType->isRealFloatingType();
3919 
3920  // x -> y
3921  if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
3922  // do nothing
3923  } else if (From->getType()->isRealFloatingType()) {
3924  From = ImpCastExprToType(From, ElType,
3925  isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
3926  } else {
3927  assert(From->getType()->isIntegerType());
3928  From = ImpCastExprToType(From, ElType,
3929  isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
3930  }
3931  // y -> _Complex y
3932  From = ImpCastExprToType(From, ToType,
3933  isFloatingComplex ? CK_FloatingRealToComplex
3934  : CK_IntegralRealToComplex).get();
3935 
3936  // Case 2. _Complex x -> y
3937  } else {
3938  const ComplexType *FromComplex = From->getType()->getAs<ComplexType>();
3939  assert(FromComplex);
3940 
3941  QualType ElType = FromComplex->getElementType();
3942  bool isFloatingComplex = ElType->isRealFloatingType();
3943 
3944  // _Complex x -> x
3945  From = ImpCastExprToType(From, ElType,
3946  isFloatingComplex ? CK_FloatingComplexToReal
3947  : CK_IntegralComplexToReal,
3948  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3949 
3950  // x -> y
3951  if (Context.hasSameUnqualifiedType(ElType, ToType)) {
3952  // do nothing
3953  } else if (ToType->isRealFloatingType()) {
3954  From = ImpCastExprToType(From, ToType,
3955  isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating,
3956  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3957  } else {
3958  assert(ToType->isIntegerType());
3959  From = ImpCastExprToType(From, ToType,
3960  isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast,
3961  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3962  }
3963  }
3964  break;
3965 
3967  From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast,
3968  VK_RValue, /*BasePath=*/nullptr, CCK).get();
3969  break;
3970  }
3971 
3973  ExprResult FromRes = From;
3974  Sema::AssignConvertType ConvTy =
3976  if (FromRes.isInvalid())
3977  return ExprError();
3978  From = FromRes.get();
3979  assert ((ConvTy == Sema::Compatible) &&
3980  "Improper transparent union conversion");
3981  (void)ConvTy;
3982  break;
3983  }
3984 
3986  From = ImpCastExprToType(From, ToType,
3987  CK_ZeroToOCLEvent,
3988  From->getValueKind()).get();
3989  break;
3990 
3992  From = ImpCastExprToType(From, ToType,
3993  CK_ZeroToOCLQueue,
3994  From->getValueKind()).get();
3995  break;
3996 
3997  case ICK_Lvalue_To_Rvalue:
3998  case ICK_Array_To_Pointer:
4001  case ICK_Qualification:
4003  case ICK_C_Only_Conversion:
4005  llvm_unreachable("Improper second standard conversion");
4006  }
4007 
4008  switch (SCS.Third) {
4009  case ICK_Identity:
4010  // Nothing to do.
4011  break;
4012 
4014  // If both sides are functions (or pointers/references to them), there could
4015  // be incompatible exception declarations.
4016  if (CheckExceptionSpecCompatibility(From, ToType))
4017  return ExprError();
4018 
4019  From = ImpCastExprToType(From, ToType, CK_NoOp,
4020  VK_RValue, /*BasePath=*/nullptr, CCK).get();
4021  break;
4022 
4023  case ICK_Qualification: {
4024  // The qualification keeps the category of the inner expression, unless the
4025  // target type isn't a reference.
4026  ExprValueKind VK = ToType->isReferenceType() ?
4027  From->getValueKind() : VK_RValue;
4028  From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context),
4029  CK_NoOp, VK, /*BasePath=*/nullptr, CCK).get();
4030 
4032  !getLangOpts().WritableStrings) {
4033  Diag(From->getLocStart(), getLangOpts().CPlusPlus11
4034  ? diag::ext_deprecated_string_literal_conversion
4035  : diag::warn_deprecated_string_literal_conversion)
4036  << ToType.getNonReferenceType();
4037  }
4038 
4039  break;
4040  }
4041 
4042  default:
4043  llvm_unreachable("Improper third standard conversion");
4044  }
4045 
4046  // If this conversion sequence involved a scalar -> atomic conversion, perform
4047  // that conversion now.
4048  if (!ToAtomicType.isNull()) {
4049  assert(Context.hasSameType(
4050  ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()));
4051  From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic,
4052  VK_RValue, nullptr, CCK).get();
4053  }
4054 
4055  // If this conversion sequence succeeded and involved implicitly converting a
4056  // _Nullable type to a _Nonnull one, complain.
4057  if (CCK == CCK_ImplicitConversion)
4058  diagnoseNullableToNonnullConversion(ToType, InitialFromType,
4059  From->getLocStart());
4060 
4061  return From;
4062 }
4063 
4064 /// \brief Check the completeness of a type in a unary type trait.
4065 ///
4066 /// If the particular type trait requires a complete type, tries to complete
4067 /// it. If completing the type fails, a diagnostic is emitted and false
4068 /// returned. If completing the type succeeds or no completion was required,
4069 /// returns true.
4071  SourceLocation Loc,
4072  QualType ArgTy) {
4073  // C++0x [meta.unary.prop]p3:
4074  // For all of the class templates X declared in this Clause, instantiating
4075  // that template with a template argument that is a class template
4076  // specialization may result in the implicit instantiation of the template
4077  // argument if and only if the semantics of X require that the argument
4078  // must be a complete type.
4079  // We apply this rule to all the type trait expressions used to implement
4080  // these class templates. We also try to follow any GCC documented behavior
4081  // in these expressions to ensure portability of standard libraries.
4082  switch (UTT) {
4083  default: llvm_unreachable("not a UTT");
4084  // is_complete_type somewhat obviously cannot require a complete type.
4085  case UTT_IsCompleteType:
4086  // Fall-through
4087 
4088  // These traits are modeled on the type predicates in C++0x
4089  // [meta.unary.cat] and [meta.unary.comp]. They are not specified as
4090  // requiring a complete type, as whether or not they return true cannot be
4091  // impacted by the completeness of the type.
4092  case UTT_IsVoid:
4093  case UTT_IsIntegral:
4094  case UTT_IsFloatingPoint:
4095  case UTT_IsArray:
4096  case UTT_IsPointer:
4097  case UTT_IsLvalueReference:
4098  case UTT_IsRvalueReference:
4101  case UTT_IsEnum:
4102  case UTT_IsUnion:
4103  case UTT_IsClass:
4104  case UTT_IsFunction:
4105  case UTT_IsReference:
4106  case UTT_IsArithmetic:
4107  case UTT_IsFundamental:
4108  case UTT_IsObject:
4109  case UTT_IsScalar:
4110  case UTT_IsCompound:
4111  case UTT_IsMemberPointer:
4112  // Fall-through
4113 
4114  // These traits are modeled on type predicates in C++0x [meta.unary.prop]
4115  // which requires some of its traits to have the complete type. However,
4116  // the completeness of the type cannot impact these traits' semantics, and
4117  // so they don't require it. This matches the comments on these traits in
4118  // Table 49.
4119  case UTT_IsConst:
4120  case UTT_IsVolatile:
4121  case UTT_IsSigned:
4122  case UTT_IsUnsigned:
4123 
4124  // This type trait always returns false, checking the type is moot.
4125  case UTT_IsInterfaceClass:
4126  return true;
4127 
4128  // C++14 [meta.unary.prop]:
4129  // If T is a non-union class type, T shall be a complete type.
4130  case UTT_IsEmpty:
4131  case UTT_IsPolymorphic:
4132  case UTT_IsAbstract:
4133  if (const auto *RD = ArgTy->getAsCXXRecordDecl())
4134  if (!RD->isUnion())
4135  return !S.RequireCompleteType(
4136  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4137  return true;
4138 
4139  // C++14 [meta.unary.prop]:
4140  // If T is a class type, T shall be a complete type.
4141  case UTT_IsFinal:
4142  case UTT_IsSealed:
4143  if (ArgTy->getAsCXXRecordDecl())
4144  return !S.RequireCompleteType(
4145  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4146  return true;
4147 
4148  // C++1z [meta.unary.prop]:
4149  // remove_all_extents_t<T> shall be a complete type or cv void.
4150  case UTT_IsAggregate:
4151  case UTT_IsTrivial:
4153  case UTT_IsStandardLayout:
4154  case UTT_IsPOD:
4155  case UTT_IsLiteral:
4156  // Per the GCC type traits documentation, T shall be a complete type, cv void,
4157  // or an array of unknown bound. But GCC actually imposes the same constraints
4158  // as above.
4159  case UTT_HasNothrowAssign:
4162  case UTT_HasNothrowCopy:
4163  case UTT_HasTrivialAssign:
4167  case UTT_HasTrivialCopy:
4170  ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0);
4171  LLVM_FALLTHROUGH;
4172 
4173  // C++1z [meta.unary.prop]:
4174  // T shall be a complete type, cv void, or an array of unknown bound.
4175  case UTT_IsDestructible:
4178  if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType())
4179  return true;
4180 
4181  return !S.RequireCompleteType(
4182  Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
4183  }
4184 }
4185 
4187  Sema &Self, SourceLocation KeyLoc, ASTContext &C,
4188  bool (CXXRecordDecl::*HasTrivial)() const,
4189  bool (CXXRecordDecl::*HasNonTrivial)() const,
4190  bool (CXXMethodDecl::*IsDesiredOp)() const)
4191 {
4192  CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
4193  if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)())
4194  return true;
4195 
4197  DeclarationNameInfo NameInfo(Name, KeyLoc);
4198  LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName);
4199  if (Self.LookupQualifiedName(Res, RD)) {
4200  bool FoundOperator = false;
4201  Res.suppressDiagnostics();
4202  for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end();
4203  Op != OpEnd; ++Op) {
4204  if (isa<FunctionTemplateDecl>(*Op))
4205  continue;
4206 
4207  CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op);
4208  if((Operator->*IsDesiredOp)()) {
4209  FoundOperator = true;
4210  const FunctionProtoType *CPT =
4211  Operator->getType()->getAs<FunctionProtoType>();
4212  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
4213  if (!CPT || !CPT->isNothrow(C))
4214  return false;
4215  }
4216  }
4217  return FoundOperator;
4218  }
4219  return false;
4220 }
4221 
4222 static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
4223  SourceLocation KeyLoc, QualType T) {
4224  assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
4225 
4226  ASTContext &C = Self.Context;
4227  switch(UTT) {
4228  default: llvm_unreachable("not a UTT");
4229  // Type trait expressions corresponding to the primary type category
4230  // predicates in C++0x [meta.unary.cat].
4231  case UTT_IsVoid:
4232  return T->isVoidType();
4233  case UTT_IsIntegral:
4234  return T->isIntegralType(C);
4235  case UTT_IsFloatingPoint:
4236  return T->isFloatingType();
4237  case UTT_IsArray:
4238  return T->isArrayType();
4239  case UTT_IsPointer:
4240  return T->isPointerType();
4241  case UTT_IsLvalueReference:
4242  return T->isLValueReferenceType();
4243  case UTT_IsRvalueReference:
4244  return T->isRValueReferenceType();
4246  return T->isMemberFunctionPointerType();
4248  return T->isMemberDataPointerType();
4249  case UTT_IsEnum:
4250  return T->isEnumeralType();
4251  case UTT_IsUnion:
4252  return T->isUnionType();
4253  case UTT_IsClass:
4254  return T->isClassType() || T->isStructureType() || T->isInterfaceType();
4255  case UTT_IsFunction:
4256  return T->isFunctionType();
4257 
4258  // Type trait expressions which correspond to the convenient composition
4259  // predicates in C++0x [meta.unary.comp].
4260  case UTT_IsReference:
4261  return T->isReferenceType();
4262  case UTT_IsArithmetic:
4263  return T->isArithmeticType() && !T->isEnumeralType();
4264  case UTT_IsFundamental:
4265  return T->isFundamentalType();
4266  case UTT_IsObject:
4267  return T->isObjectType();
4268  case UTT_IsScalar:
4269  // Note: semantic analysis depends on Objective-C lifetime types to be
4270  // considered scalar types. However, such types do not actually behave
4271  // like scalar types at run time (since they may require retain/release
4272  // operations), so we report them as non-scalar.
4273  if (T->isObjCLifetimeType()) {
4274  switch (T.getObjCLifetime()) {
4275  case Qualifiers::OCL_None:
4277  return true;
4278 
4280  case Qualifiers::OCL_Weak:
4282  return false;
4283  }
4284  }
4285 
4286  return T->isScalarType();
4287  case UTT_IsCompound:
4288  return T->isCompoundType();
4289  case UTT_IsMemberPointer:
4290  return T->isMemberPointerType();
4291 
4292  // Type trait expressions which correspond to the type property predicates
4293  // in C++0x [meta.unary.prop].
4294  case UTT_IsConst:
4295  return T.isConstQualified();
4296  case UTT_IsVolatile:
4297  return T.isVolatileQualified();
4298  case UTT_IsTrivial:
4299  return T.isTrivialType(C);
4301  return T.isTriviallyCopyableType(C);
4302  case UTT_IsStandardLayout:
4303  return T->isStandardLayoutType();
4304  case UTT_IsPOD:
4305  return T.isPODType(C);
4306  case UTT_IsLiteral:
4307  return T->isLiteralType(C);
4308  case UTT_IsEmpty:
4309  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4310  return !RD->isUnion() && RD->isEmpty();
4311  return false;
4312  case UTT_IsPolymorphic:
4313  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4314  return !RD->isUnion() && RD->isPolymorphic();
4315  return false;
4316  case UTT_IsAbstract:
4317  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4318  return !RD->isUnion() && RD->isAbstract();
4319  return false;
4320  case UTT_IsAggregate:
4321  // Report vector extensions and complex types as aggregates because they
4322  // support aggregate initialization. GCC mirrors this behavior for vectors
4323  // but not _Complex.
4324  return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() ||
4325  T->isAnyComplexType();
4326  // __is_interface_class only returns true when CL is invoked in /CLR mode and
4327  // even then only when it is used with the 'interface struct ...' syntax
4328  // Clang doesn't support /CLR which makes this type trait moot.
4329  case UTT_IsInterfaceClass:
4330  return false;
4331  case UTT_IsFinal:
4332  case UTT_IsSealed:
4333  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4334  return RD->hasAttr<FinalAttr>();
4335  return false;
4336  case UTT_IsSigned:
4337  return T->isSignedIntegerType();
4338  case UTT_IsUnsigned:
4339  return T->isUnsignedIntegerType();
4340 
4341  // Type trait expressions which query classes regarding their construction,
4342  // destruction, and copying. Rather than being based directly on the
4343  // related type predicates in the standard, they are specified by both
4344  // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those
4345  // specifications.
4346  //
4347  // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html
4348  // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
4349  //
4350  // Note that these builtins do not behave as documented in g++: if a class
4351  // has both a trivial and a non-trivial special member of a particular kind,
4352  // they return false! For now, we emulate this behavior.
4353  // FIXME: This appears to be a g++ bug: more complex cases reveal that it
4354  // does not correctly compute triviality in the presence of multiple special
4355  // members of the same kind. Revisit this once the g++ bug is fixed.
4357  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4358  // If __is_pod (type) is true then the trait is true, else if type is
4359  // a cv class or union type (or array thereof) with a trivial default
4360  // constructor ([class.ctor]) then the trait is true, else it is false.
4361  if (T.isPODType(C))
4362  return true;
4363  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
4364  return RD->hasTrivialDefaultConstructor() &&
4365  !RD->hasNonTrivialDefaultConstructor();
4366  return false;
4368  // This trait is implemented by MSVC 2012 and needed to parse the
4369  // standard library headers. Specifically this is used as the logic
4370  // behind std::is_trivially_move_constructible (20.9.4.3).
4371  if (T.isPODType(C))
4372  return true;
4373  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
4374  return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor();
4375  return false;
4376  case UTT_HasTrivialCopy:
4377  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4378  // If __is_pod (type) is true or type is a reference type then
4379  // the trait is true, else if type is a cv class or union type
4380  // with a trivial copy constructor ([class.copy]) then the trait
4381  // is true, else it is false.
4382  if (T.isPODType(C) || T->isReferenceType())
4383  return true;
4384  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4385  return RD->hasTrivialCopyConstructor() &&
4386  !RD->hasNonTrivialCopyConstructor();
4387  return false;
4389  // This trait is implemented by MSVC 2012 and needed to parse the
4390  // standard library headers. Specifically it is used as the logic
4391  // behind std::is_trivially_move_assignable (20.9.4.3)
4392  if (T.isPODType(C))
4393  return true;
4394  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
4395  return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment();
4396  return false;
4397  case UTT_HasTrivialAssign:
4398  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4399  // If type is const qualified or is a reference type then the
4400  // trait is false. Otherwise if __is_pod (type) is true then the
4401  // trait is true, else if type is a cv class or union type with
4402  // a trivial copy assignment ([class.copy]) then the trait is
4403  // true, else it is false.
4404  // Note: the const and reference restrictions are interesting,
4405  // given that const and reference members don't prevent a class
4406  // from having a trivial copy assignment operator (but do cause
4407  // errors if the copy assignment operator is actually used, q.v.
4408  // [class.copy]p12).
4409 
4410  if (T.isConstQualified())
4411  return false;
4412  if (T.isPODType(C))
4413  return true;
4414  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4415  return RD->hasTrivialCopyAssignment() &&
4416  !RD->hasNonTrivialCopyAssignment();
4417  return false;
4418  case UTT_IsDestructible:
4421  // C++14 [meta.unary.prop]:
4422  // For reference types, is_destructible<T>::value is true.
4423  if (T->isReferenceType())
4424  return true;
4425 
4426  // Objective-C++ ARC: autorelease types don't require destruction.
4427  if (T->isObjCLifetimeType() &&
4429  return true;
4430 
4431  // C++14 [meta.unary.prop]:
4432  // For incomplete types and function types, is_destructible<T>::value is
4433  // false.
4434  if (T->isIncompleteType() || T->isFunctionType())
4435  return false;
4436 
4437  // A type that requires destruction (via a non-trivial destructor or ARC
4438  // lifetime semantics) is not trivially-destructible.
4440  return false;
4441 
4442  // C++14 [meta.unary.prop]:
4443  // For object types and given U equal to remove_all_extents_t<T>, if the
4444  // expression std::declval<U&>().~U() is well-formed when treated as an
4445  // unevaluated operand (Clause 5), then is_destructible<T>::value is true
4446  if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
4447  CXXDestructorDecl *Destructor = Self.LookupDestructor(RD);
4448  if (!Destructor)
4449  return false;
4450  // C++14 [dcl.fct.def.delete]p2:
4451  // A program that refers to a deleted function implicitly or
4452  // explicitly, other than to declare it, is ill-formed.
4453  if (Destructor->isDeleted())
4454  return false;
4455  if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public)
4456  return false;
4457  if (UTT == UTT_IsNothrowDestructible) {
4458  const FunctionProtoType *CPT =
4459  Destructor->getType()->getAs<FunctionProtoType>();
4460  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
4461  if (!CPT || !CPT->isNothrow(C))
4462  return false;
4463  }
4464  }
4465  return true;
4466 
4468  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
4469  // If __is_pod (type) is true or type is a reference type
4470  // then the trait is true, else if type is a cv class or union
4471  // type (or array thereof) with a trivial destructor
4472  // ([class.dtor]) then the trait is true, else it is
4473  // false.
4474  if (T.isPODType(C) || T->isReferenceType())
4475  return true;
4476 
4477  // Objective-C++ ARC: autorelease types don't require destruction.
4478  if (T->isObjCLifetimeType() &&
4480  return true;
4481 
4482  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
4483  return RD->hasTrivialDestructor();
4484  return false;
4485  // TODO: Propagate nothrowness for implicitly declared special members.
4486  case UTT_HasNothrowAssign:
4487  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4488  // If type is const qualified or is a reference type then the
4489  // trait is false. Otherwise if __has_trivial_assign (type)
4490  // is true then the trait is true, else if type is a cv class
4491  // or union type with copy assignment operators that are known
4492  // not to throw an exception then the trait is true, else it is
4493  // false.
4494  if (C.getBaseElementType(T).isConstQualified())
4495  return false;
4496  if (T->isReferenceType())
4497  return false;
4498  if (T.isPODType(C) || T->isObjCLifetimeType())
4499  return true;
4500 
4501  if (const RecordType *RT = T->getAs<RecordType>())
4502  return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
4506  return false;
4508  // This trait is implemented by MSVC 2012 and needed to parse the
4509  // standard library headers. Specifically this is used as the logic
4510  // behind std::is_nothrow_move_assignable (20.9.4.3).
4511  if (T.isPODType(C))
4512  return true;
4513 
4514  if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>())
4515  return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
4519  return false;
4520  case UTT_HasNothrowCopy:
4521  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4522  // If __has_trivial_copy (type) is true then the trait is true, else
4523  // if type is a cv class or union type with copy constructors that are
4524  // known not to throw an exception then the trait is true, else it is
4525  // false.
4526  if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType())
4527  return true;
4528  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
4529  if (RD->hasTrivialCopyConstructor() &&
4530  !RD->hasNonTrivialCopyConstructor())
4531  return true;
4532 
4533  bool FoundConstructor = false;
4534  unsigned FoundTQs;
4535  for (const auto *ND : Self.LookupConstructors(RD)) {
4536  // A template constructor is never a copy constructor.
4537  // FIXME: However, it may actually be selected at the actual overload
4538  // resolution point.
4539  if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
4540  continue;
4541  // UsingDecl itself is not a constructor
4542  if (isa<UsingDecl>(ND))
4543  continue;
4544  auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
4545  if (Constructor->isCopyConstructor(FoundTQs)) {
4546  FoundConstructor = true;
4547  const FunctionProtoType *CPT
4548  = Constructor->getType()->getAs<FunctionProtoType>();
4549  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
4550  if (!CPT)
4551  return false;
4552  // TODO: check whether evaluating default arguments can throw.
4553  // For now, we'll be conservative and assume that they can throw.
4554  if (!CPT->isNothrow(C) || CPT->getNumParams() > 1)
4555  return false;
4556  }
4557  }
4558 
4559  return FoundConstructor;
4560  }
4561  return false;
4563  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
4564  // If __has_trivial_constructor (type) is true then the trait is
4565  // true, else if type is a cv class or union type (or array
4566  // thereof) with a default constructor that is known not to
4567  // throw an exception then the trait is true, else it is false.
4568  if (T.isPODType(C) || T->isObjCLifetimeType())
4569  return true;
4570  if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
4571  if (RD->hasTrivialDefaultConstructor() &&
4572  !RD->hasNonTrivialDefaultConstructor())
4573  return true;
4574 
4575  bool FoundConstructor = false;
4576  for (const auto *ND : Self.LookupConstructors(RD)) {
4577  // FIXME: In C++0x, a constructor template can be a default constructor.
4578  if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
4579  continue;
4580  // UsingDecl itself is not a constructor
4581  if (isa<UsingDecl>(ND))
4582  continue;
4583  auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
4584  if (Constructor->isDefaultConstructor()) {
4585  FoundConstructor = true;
4586  const FunctionProtoType *CPT
4587  = Constructor->getType()->getAs<FunctionProtoType>();
4588  CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
4589  if (!CPT)
4590  return false;
4591  // FIXME: check whether evaluating default arguments can throw.
4592  // For now, we'll be conservative and assume that they can throw.
4593  if (!CPT->isNothrow(C) || CPT->getNumParams() > 0)
4594  return false;
4595  }
4596  }
4597  return FoundConstructor;
4598  }
4599  return false;
4601  // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
4602  // If type is a class type with a virtual destructor ([class.dtor])
4603  // then the trait is true, else it is false.
4604  if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4605  if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD))
4606  return Destructor->isVirtual();
4607  return false;
4608 
4609  // These type trait expressions are modeled on the specifications for the
4610  // Embarcadero C++0x type trait functions:
4611  // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
4612  case UTT_IsCompleteType:
4613  // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_):
4614  // Returns True if and only if T is a complete type at the point of the
4615  // function call.
4616  return !T->isIncompleteType();
4617  }
4618 }
4619 
4620 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
4621  QualType RhsT, SourceLocation KeyLoc);
4622 
4625  SourceLocation RParenLoc) {
4626  if (Kind <= UTT_Last)
4627  return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType());
4628 
4629  if (Kind <= BTT_Last)
4630  return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(),
4631  Args[1]->getType(), RParenLoc);
4632 
4633  switch (Kind) {
4637  // C++11 [meta.unary.prop]:
4638  // is_trivially_constructible is defined as:
4639  //
4640  // is_constructible<T, Args...>::value is true and the variable
4641  // definition for is_constructible, as defined below, is known to call
4642  // no operation that is not trivial.
4643  //
4644  // The predicate condition for a template specialization
4645  // is_constructible<T, Args...> shall be satisfied if and only if the
4646  // following variable definition would be well-formed for some invented
4647  // variable t:
4648  //
4649  // T t(create<Args>()...);
4650  assert(!Args.empty());
4651 
4652  // Precondition: T and all types in the parameter pack Args shall be
4653  // complete types, (possibly cv-qualified) void, or arrays of
4654  // unknown bound.
4655  for (const auto *TSI : Args) {
4656  QualType ArgTy = TSI->getType();
4657  if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType())
4658  continue;
4659 
4660  if (S.RequireCompleteType(KWLoc, ArgTy,
4661  diag::err_incomplete_type_used_in_type_trait_expr))
4662  return false;
4663  }
4664 
4665  // Make sure the first argument is not incomplete nor a function type.
4666  QualType T = Args[0]->getType();
4667  if (T->isIncompleteType() || T->isFunctionType())
4668  return false;
4669 
4670  // Make sure the first argument is not an abstract type.
4671  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
4672  if (RD && RD->isAbstract())
4673  return false;
4674 
4675  SmallVector<OpaqueValueExpr, 2> OpaqueArgExprs;
4676  SmallVector<Expr *, 2> ArgExprs;
4677  ArgExprs.reserve(Args.size() - 1);
4678  for (unsigned I = 1, N = Args.size(); I != N; ++I) {
4679  QualType ArgTy = Args[I]->getType();
4680  if (ArgTy->isObjectType() || ArgTy->isFunctionType())
4681  ArgTy = S.Context.getRValueReferenceType(ArgTy);
4682  OpaqueArgExprs.push_back(
4683  OpaqueValueExpr(Args[I]->getTypeLoc().getLocStart(),
4684  ArgTy.getNonLValueExprType(S.Context),
4685  Expr::getValueKindForType(ArgTy)));
4686  }
4687  for (Expr &E : OpaqueArgExprs)
4688  ArgExprs.push_back(&E);
4689 
4690  // Perform the initialization in an unevaluated context within a SFINAE
4691  // trap at translation unit scope.
4694  Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
4698  RParenLoc));
4699  InitializationSequence Init(S, To, InitKind, ArgExprs);
4700  if (Init.Failed())
4701  return false;
4702 
4703  ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs);
4704  if (Result.isInvalid() || SFINAE.hasErrorOccurred())
4705  return false;
4706 
4707  if (Kind == clang::TT_IsConstructible)
4708  return true;
4709 
4711  return S.canThrow(Result.get()) == CT_Cannot;
4712 
4713  if (Kind == clang::TT_IsTriviallyConstructible) {
4714  // Under Objective-C ARC and Weak, if the destination has non-trivial
4715  // Objective-C lifetime, this is a non-trivial construction.
4717  return false;
4718 
4719  // The initialization succeeded; now make sure there are no non-trivial
4720  // calls.
4721  return !Result.get()->hasNonTrivialCall(S.Context);
4722  }
4723 
4724  llvm_unreachable("unhandled type trait");
4725  return false;
4726  }
4727  default: llvm_unreachable("not a TT");
4728  }
4729 
4730  return false;
4731 }
4732 
4735  SourceLocation RParenLoc) {
4736  QualType ResultType = Context.getLogicalOperationType();
4737 
4739  *this, Kind, KWLoc, Args[0]->getType()))
4740  return ExprError();
4741 
4742  bool Dependent = false;
4743  for (unsigned I = 0, N = Args.size(); I != N; ++I) {
4744  if (Args[I]->getType()->isDependentType()) {
4745  Dependent = true;
4746  break;
4747  }
4748  }
4749 
4750  bool Result = false;
4751  if (!Dependent)
4752  Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc);
4753 
4754  return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args,
4755  RParenLoc, Result);
4756 }
4757 
4759  ArrayRef<ParsedType> Args,
4760  SourceLocation RParenLoc) {
4761  SmallVector<TypeSourceInfo *, 4> ConvertedArgs;
4762  ConvertedArgs.reserve(Args.size());
4763 
4764  for (unsigned I = 0, N = Args.size(); I != N; ++I) {
4765  TypeSourceInfo *TInfo;
4766  QualType T = GetTypeFromParser(Args[I], &TInfo);
4767  if (!TInfo)
4768  TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc);
4769 
4770  ConvertedArgs.push_back(TInfo);
4771  }
4772 
4773  return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc);
4774 }
4775 
4776 static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
4777  QualType RhsT, SourceLocation KeyLoc) {
4778  assert(!LhsT->isDependentType() && !RhsT->isDependentType() &&
4779  "Cannot evaluate traits of dependent types");
4780 
4781  switch(BTT) {
4782  case BTT_IsBaseOf: {
4783  // C++0x [meta.rel]p2
4784  // Base is a base class of Derived without regard to cv-qualifiers or
4785  // Base and Derived are not unions and name the same class type without
4786  // regard to cv-qualifiers.
4787 
4788  const RecordType *lhsRecord = LhsT->getAs<RecordType>();
4789  const RecordType *rhsRecord = RhsT->getAs<RecordType>();
4790  if (!rhsRecord || !lhsRecord) {
4791  const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>();
4792  const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>();
4793  if (!LHSObjTy || !RHSObjTy)
4794  return false;
4795 
4796  ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface();
4797  ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface();
4798  if (!BaseInterface || !DerivedInterface)
4799  return false;
4800 
4801  if (Self.RequireCompleteType(
4802  KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr))
4803  return false;
4804 
4805  return BaseInterface->isSuperClassOf(DerivedInterface);
4806  }
4807 
4808  assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)
4809  == (lhsRecord == rhsRecord));
4810 
4811  if (lhsRecord == rhsRecord)
4812  return !lhsRecord->getDecl()->isUnion();
4813 
4814  // C++0x [meta.rel]p2:
4815  // If Base and Derived are class types and are different types
4816  // (ignoring possible cv-qualifiers) then Derived shall be a
4817  // complete type.
4818  if (Self.RequireCompleteType(KeyLoc, RhsT,
4819  diag::err_incomplete_type_used_in_type_trait_expr))
4820  return false;
4821 
4822  return cast<CXXRecordDecl>(rhsRecord->getDecl())
4823  ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl()));
4824  }
4825  case BTT_IsSame:
4826  return Self.Context.hasSameType(LhsT, RhsT);
4827  case BTT_TypeCompatible: {
4828  // GCC ignores cv-qualifiers on arrays for this builtin.
4829  Qualifiers LhsQuals, RhsQuals;
4830  QualType Lhs = Self.getASTContext().getUnqualifiedArrayType(LhsT, LhsQuals);
4831  QualType Rhs = Self.getASTContext().getUnqualifiedArrayType(RhsT, RhsQuals);
4832  return Self.Context.typesAreCompatible(Lhs, Rhs);
4833  }
4834  case BTT_IsConvertible:
4835  case BTT_IsConvertibleTo: {
4836  // C++0x [meta.rel]p4:
4837  // Given the following function prototype:
4838  //
4839  // template <class T>
4840  // typename add_rvalue_reference<T>::type create();
4841  //
4842  // the predicate condition for a template specialization
4843  // is_convertible<From, To> shall be satisfied if and only if
4844  // the return expression in the following code would be
4845  // well-formed, including any implicit conversions to the return
4846  // type of the function:
4847  //
4848  // To test() {
4849  // return create<From>();
4850  // }
4851  //
4852  // Access checking is performed as if in a context unrelated to To and
4853  // From. Only the validity of the immediate context of the expression
4854  // of the return-statement (including conversions to the return type)
4855  // is considered.
4856  //
4857  // We model the initialization as a copy-initialization of a temporary
4858  // of the appropriate type, which for this expression is identical to the
4859  // return statement (since NRVO doesn't apply).
4860 
4861  // Functions aren't allowed to return function or array types.
4862  if (RhsT->isFunctionType() || RhsT->isArrayType())
4863  return false;
4864 
4865  // A return statement in a void function must have void type.
4866  if (RhsT->isVoidType())
4867  return LhsT->isVoidType();
4868 
4869  // A function definition requires a complete, non-abstract return type.
4870  if (!Self.isCompleteType(KeyLoc, RhsT) || Self.isAbstractType(KeyLoc, RhsT))
4871  return false;
4872 
4873  // Compute the result of add_rvalue_reference.
4874  if (LhsT->isObjectType() || LhsT->isFunctionType())
4875  LhsT = Self.Context.getRValueReferenceType(LhsT);
4876 
4877  // Build a fake source and destination for initialization.
4879  OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
4881  Expr *FromPtr = &From;
4883  SourceLocation()));
4884 
4885  // Perform the initialization in an unevaluated context within a SFINAE
4886  // trap at translation unit scope.
4889  Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
4890  Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
4891  InitializationSequence Init(Self, To, Kind, FromPtr);
4892  if (Init.Failed())
4893  return false;
4894 
4895  ExprResult Result = Init.Perform(Self, To, Kind, FromPtr);
4896  return !Result.isInvalid() && !SFINAE.hasErrorOccurred();
4897  }
4898 
4899  case BTT_IsAssignable:
4902  // C++11 [meta.unary.prop]p3:
4903  // is_trivially_assignable is defined as:
4904  // is_assignable<T, U>::value is true and the assignment, as defined by
4905  // is_assignable, is known to call no operation that is not trivial
4906  //
4907  // is_assignable is defined as:
4908  // The expression declval<T>() = declval<U>() is well-formed when
4909  // treated as an unevaluated operand (Clause 5).
4910  //
4911  // For both, T and U shall be complete types, (possibly cv-qualified)
4912  // void, or arrays of unknown bound.
4913  if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() &&
4914  Self.RequireCompleteType(KeyLoc, LhsT,
4915  diag::err_incomplete_type_used_in_type_trait_expr))
4916  return false;
4917  if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() &&
4918  Self.RequireCompleteType(KeyLoc, RhsT,
4919  diag::err_incomplete_type_used_in_type_trait_expr))
4920  return false;
4921 
4922  // cv void is never assignable.
4923  if (LhsT->isVoidType() || RhsT->isVoidType())
4924  return false;
4925 
4926  // Build expressions that emulate the effect of declval<T>() and
4927  // declval<U>().
4928  if (LhsT->isObjectType() || LhsT->isFunctionType())
4929  LhsT = Self.Context.getRValueReferenceType(LhsT);
4930  if (RhsT->isObjectType() || RhsT->isFunctionType())
4931  RhsT = Self.Context.getRValueReferenceType(RhsT);
4932  OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
4934  OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context),
4936 
4937  // Attempt the assignment in an unevaluated context within a SFINAE
4938  // trap at translation unit scope.
4941  Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
4942  Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
4943  ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs,
4944  &Rhs);
4945  if (Result.isInvalid() || SFINAE.hasErrorOccurred())
4946  return false;
4947 
4948  if (BTT == BTT_IsAssignable)
4949  return true;
4950 
4951  if (BTT == BTT_IsNothrowAssignable)
4952  return Self.canThrow(Result.get()) == CT_Cannot;
4953 
4954  if (BTT == BTT_IsTriviallyAssignable) {
4955  // Under Objective-C ARC and Weak, if the destination has non-trivial
4956  // Objective-C lifetime, this is a non-trivial assignment.
4958  return false;
4959 
4960  return !Result.get()->hasNonTrivialCall(Self.Context);
4961  }
4962 
4963  llvm_unreachable("unhandled type trait");
4964  return false;
4965  }
4966  default: llvm_unreachable("not a BTT");
4967  }
4968  llvm_unreachable("Unknown type trait or not implemented");
4969 }
4970 
4972  SourceLocation KWLoc,
4973  ParsedType Ty,
4974  Expr* DimExpr,
4975  SourceLocation RParen) {
4976  TypeSourceInfo *TSInfo;
4977  QualType T = GetTypeFromParser(Ty, &TSInfo);
4978  if (!TSInfo)
4979  TSInfo = Context.getTrivialTypeSourceInfo(T);
4980 
4981  return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen);
4982 }
4983 
4984 static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT,
4985  QualType T, Expr *DimExpr,
4986  SourceLocation KeyLoc) {
4987  assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
4988 
4989  switch(ATT) {
4990  case ATT_ArrayRank:
4991  if (T->isArrayType()) {
4992  unsigned Dim = 0;
4993  while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
4994  ++Dim;
4995  T = AT->getElementType();
4996  }
4997  return Dim;
4998  }
4999  return 0;
5000 
5001  case ATT_ArrayExtent: {
5002  llvm::APSInt Value;
5003  uint64_t Dim;
5004  if (Self.VerifyIntegerConstantExpression(DimExpr, &Value,
5005  diag::err_dimension_expr_not_constant_integer,
5006  false).isInvalid())
5007  return 0;
5008  if (Value.isSigned() && Value.isNegative()) {
5009  Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer)
5010  << DimExpr->getSourceRange();
5011  return 0;
5012  }
5013  Dim = Value.getLimitedValue();
5014 
5015  if (T->isArrayType()) {
5016  unsigned D = 0;
5017  bool Matched = false;
5018  while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
5019  if (Dim == D) {
5020  Matched = true;
5021  break;
5022  }
5023  ++D;
5024  T = AT->getElementType();
5025  }
5026 
5027  if (Matched && T->isArrayType()) {
5028  if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T))
5029  return CAT->getSize().getLimitedValue();
5030  }
5031  }
5032  return 0;
5033  }
5034  }
5035  llvm_unreachable("Unknown type trait or not implemented");
5036 }
5037 
5039  SourceLocation KWLoc,
5040  TypeSourceInfo *TSInfo,
5041  Expr* DimExpr,
5042  SourceLocation RParen) {
5043  QualType T = TSInfo->getType();
5044 
5045  // FIXME: This should likely be tracked as an APInt to remove any host
5046  // assumptions about the width of size_t on the target.
5047  uint64_t Value = 0;
5048  if (!T->isDependentType())
5049  Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc);
5050 
5051  // While the specification for these traits from the Embarcadero C++
5052  // compiler's documentation says the return type is 'unsigned int', Clang
5053  // returns 'size_t'. On Windows, the primary platform for the Embarcadero
5054  // compiler, there is no difference. On several other platforms this is an
5055  // important distinction.
5056  return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr,
5057  RParen, Context.getSizeType());
5058 }
5059 
5061  SourceLocation KWLoc,
5062  Expr *Queried,
5063  SourceLocation RParen) {
5064  // If error parsing the expression, ignore.
5065  if (!Queried)
5066  return ExprError();
5067 
5068  ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen);
5069 
5070  return Result;
5071 }
5072 
5074  switch (ET) {
5075  case ET_IsLValueExpr: return E->isLValue();
5076  case ET_IsRValueExpr: return E->isRValue();
5077  }
5078  llvm_unreachable("Expression trait not covered by switch");
5079 }
5080 
5082  SourceLocation KWLoc,
5083  Expr *Queried,
5084  SourceLocation RParen) {
5085  if (Queried->isTypeDependent()) {
5086  // Delay type-checking for type-dependent expressions.
5087  } else if (Queried->getType()->isPlaceholderType()) {
5088  ExprResult PE = CheckPlaceholderExpr(Queried);
5089  if (PE.isInvalid()) return ExprError();
5090  return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen);
5091  }
5092 
5093  bool Value = EvaluateExpressionTrait(ET, Queried);
5094 
5095  return new (Context)
5096  ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy);
5097 }
5098 
5100  ExprValueKind &VK,
5101  SourceLocation Loc,
5102  bool isIndirect) {
5103  assert(!LHS.get()->getType()->isPlaceholderType() &&
5104  !RHS.get()->getType()->isPlaceholderType() &&
5105  "placeholders should have been weeded out by now");
5106 
5107  // The LHS undergoes lvalue conversions if this is ->*, and undergoes the
5108  // temporary materialization conversion otherwise.
5109  if (isIndirect)
5110  LHS = DefaultLvalueConversion(LHS.get());
5111  else if (LHS.get()->isRValue())
5113  if (LHS.isInvalid())
5114  return QualType();
5115 
5116  // The RHS always undergoes lvalue conversions.
5117  RHS = DefaultLvalueConversion(RHS.get());
5118  if (RHS.isInvalid()) return QualType();
5119 
5120  const char *OpSpelling = isIndirect ? "->*" : ".*";
5121  // C++ 5.5p2
5122  // The binary operator .* [p3: ->*] binds its second operand, which shall
5123  // be of type "pointer to member of T" (where T is a completely-defined
5124  // class type) [...]
5125  QualType RHSType = RHS.get()->getType();
5126  const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>();
5127  if (!MemPtr) {
5128  Diag(Loc, diag::err_bad_memptr_rhs)
5129  << OpSpelling << RHSType << RHS.get()->getSourceRange();
5130  return QualType();
5131  }
5132 
5133  QualType Class(MemPtr->getClass(), 0);
5134 
5135  // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the
5136  // member pointer points must be completely-defined. However, there is no
5137  // reason for this semantic distinction, and the rule is not enforced by
5138  // other compilers. Therefore, we do not check this property, as it is
5139  // likely to be considered a defect.
5140 
5141  // C++ 5.5p2
5142  // [...] to its first operand, which shall be of class T or of a class of
5143  // which T is an unambiguous and accessible base class. [p3: a pointer to
5144  // such a class]
5145  QualType LHSType = LHS.get()->getType();
5146  if (isIndirect) {
5147  if (const PointerType *Ptr = LHSType->getAs<PointerType>())
5148  LHSType = Ptr->getPointeeType();
5149  else {
5150  Diag(Loc, diag::err_bad_memptr_lhs)
5151  << OpSpelling << 1 << LHSType
5153  return QualType();
5154  }
5155  }
5156 
5157  if (!Context.hasSameUnqualifiedType(Class, LHSType)) {
5158  // If we want to check the hierarchy, we need a complete type.
5159  if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs,
5160  OpSpelling, (int)isIndirect)) {
5161  return QualType();
5162  }
5163 
5164  if (!IsDerivedFrom(Loc, LHSType, Class)) {
5165  Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling
5166  << (int)isIndirect << LHS.get()->getType();
5167  return QualType();
5168  }
5169 
5170  CXXCastPath BasePath;
5171  if (CheckDerivedToBaseConversion(LHSType, Class, Loc,
5172  SourceRange(LHS.get()->getLocStart(),
5173  RHS.get()->getLocEnd()),
5174  &BasePath))
5175  return QualType();
5176 
5177  // Cast LHS to type of use.
5178  QualType UseType = Context.getQualifiedType(Class, LHSType.getQualifiers());
5179  if (isIndirect)
5180  UseType = Context.getPointerType(UseType);
5181  ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind();
5182  LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK,
5183  &BasePath);
5184  }
5185 
5186  if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) {
5187  // Diagnose use of pointer-to-member type which when used as
5188  // the functional cast in a pointer-to-member expression.
5189  Diag(Loc, diag::err_pointer_to_member_type) << isIndirect;
5190  return QualType();
5191  }
5192 
5193  // C++ 5.5p2
5194  // The result is an object or a function of the type specified by the
5195  // second operand.
5196  // The cv qualifiers are the union of those in the pointer and the left side,
5197  // in accordance with 5.5p5 and 5.2.5.
5198  QualType Result = MemPtr->getPointeeType();
5199  Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers());
5200 
5201  // C++0x [expr.mptr.oper]p6:
5202  // In a .* expression whose object expression is an rvalue, the program is
5203  // ill-formed if the second operand is a pointer to member function with
5204  // ref-qualifier &. In a ->* expression or in a .* expression whose object
5205  // expression is an lvalue, the program is ill-formed if the second operand
5206  // is a pointer to member function with ref-qualifier &&.
5207  if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) {
5208  switch (Proto->getRefQualifier()) {
5209  case RQ_None:
5210  // Do nothing
5211  break;
5212 
5213  case RQ_LValue:
5214  if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) {
5215  // C++2a allows functions with ref-qualifier & if they are also 'const'.
5216  if (Proto->isConst())
5217  Diag(Loc, getLangOpts().CPlusPlus2a
5218  ? diag::warn_cxx17_compat_pointer_to_const_ref_member_on_rvalue
5219  : diag::ext_pointer_to_const_ref_member_on_rvalue);
5220  else
5221  Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
5222  << RHSType << 1 << LHS.get()->getSourceRange();
5223  }
5224  break;
5225 
5226  case RQ_RValue:
5227  if (isIndirect || !LHS.get()->Classify(Context).isRValue())
5228  Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
5229  << RHSType << 0 << LHS.get()->getSourceRange();
5230  break;
5231  }
5232  }
5233 
5234  // C++ [expr.mptr.oper]p6:
5235  // The result of a .* expression whose second operand is a pointer
5236  // to a data member is of the same value category as its
5237  // first operand. The result of a .* expression whose second
5238  // operand is a pointer to a member function is a prvalue. The
5239  // result of an ->* expression is an lvalue if its second operand
5240  // is a pointer to data member and a prvalue otherwise.
5241  if (Result->isFunctionType()) {
5242  VK = VK_RValue;
5243  return Context.BoundMemberTy;
5244  } else if (isIndirect) {
5245  VK = VK_LValue;
5246  } else {
5247  VK = LHS.get()->getValueKind();
5248  }
5249 
5250  return Result;
5251 }
5252 
5253 /// \brief Try to convert a type to another according to C++11 5.16p3.
5254 ///
5255 /// This is part of the parameter validation for the ? operator. If either
5256 /// value operand is a class type, the two operands are attempted to be
5257 /// converted to each other. This function does the conversion in one direction.
5258 /// It returns true if the program is ill-formed and has already been diagnosed
5259 /// as such.
5260 static bool TryClassUnification(Sema &Self, Expr *From, Expr *To,
5261  SourceLocation QuestionLoc,
5262  bool &HaveConversion,
5263  QualType &ToType) {
5264  HaveConversion = false;
5265  ToType = To->getType();
5266 
5268  SourceLocation());
5269  // C++11 5.16p3
5270  // The process for determining whether an operand expression E1 of type T1
5271  // can be converted to match an operand expression E2 of type T2 is defined
5272  // as follows:
5273  // -- If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
5274  // implicitly converted to type "lvalue reference to T2", subject to the
5275  // constraint that in the conversion the reference must bind directly to
5276  // an lvalue.
5277  // -- If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
5278  // implicitly conveted to the type "rvalue reference to R2", subject to
5279  // the constraint that the reference must bind directly.
5280  if (To->isLValue() || To->isXValue()) {
5281  QualType T = To->isLValue() ? Self.Context.getLValueReferenceType(ToType)
5282  : Self.Context.getRValueReferenceType(ToType);
5283 
5285 
5286  InitializationSequence InitSeq(Self, Entity, Kind, From);
5287  if (InitSeq.isDirectReferenceBinding()) {
5288  ToType = T;
5289  HaveConversion = true;
5290  return false;
5291  }
5292 
5293  if (InitSeq.isAmbiguous())
5294  return InitSeq.Diagnose(Self, Entity, Kind, From);
5295  }
5296 
5297  // -- If E2 is an rvalue, or if the conversion above cannot be done:
5298  // -- if E1 and E2 have class type, and the underlying class types are
5299  // the same or one is a base class of the other:
5300  QualType FTy = From->getType();
5301  QualType TTy = To->getType();
5302  const RecordType *FRec = FTy->getAs<RecordType>();
5303  const RecordType *TRec = TTy->getAs<RecordType>();
5304  bool FDerivedFromT = FRec && TRec && FRec != TRec &&
5305  Self.IsDerivedFrom(QuestionLoc, FTy, TTy);
5306  if (FRec && TRec && (FRec == TRec || FDerivedFromT ||
5307  Self.IsDerivedFrom(QuestionLoc, TTy, FTy))) {
5308  // E1 can be converted to match E2 if the class of T2 is the
5309  // same type as, or a base class of, the class of T1, and
5310  // [cv2 > cv1].
5311  if (FRec == TRec || FDerivedFromT) {
5312  if (TTy.isAtLeastAsQualifiedAs(FTy)) {
5314  InitializationSequence InitSeq(Self, Entity, Kind, From);
5315  if (InitSeq) {
5316  HaveConversion = true;
5317  return false;
5318  }
5319 
5320  if (InitSeq.isAmbiguous())
5321  return InitSeq.Diagnose(Self, Entity, Kind, From);
5322  }
5323  }
5324 
5325  return false;
5326  }
5327 
5328  // -- Otherwise: E1 can be converted to match E2 if E1 can be
5329  // implicitly converted to the type that expression E2 would have
5330  // if E2 were converted to an rvalue (or the type it has, if E2 is
5331  // an rvalue).
5332  //
5333  // This actually refers very narrowly to the lvalue-to-rvalue conversion, not
5334  // to the array-to-pointer or function-to-pointer conversions.
5335  TTy = TTy.getNonLValueExprType(Self.Context);
5336 
5338  InitializationSequence InitSeq(Self, Entity, Kind, From);
5339  HaveConversion = !InitSeq.Failed();
5340  ToType = TTy;
5341  if (InitSeq.isAmbiguous())
5342  return InitSeq.Diagnose(Self, Entity, Kind, From);
5343 
5344  return false;
5345 }
5346 
5347 /// \brief Try to find a common type for two according to C++0x 5.16p5.
5348 ///
5349 /// This is part of the parameter validation for the ? operator. If either
5350 /// value operand is a class type, overload resolution is used to find a
5351 /// conversion to a common type.
5352 static bool