1 //===- ExprCXX.cpp - (C++) Expression AST Node Implementation -------------===//
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 // This file implements the subclesses of Expr class declared in ExprCXX.h
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/ExprCXX.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Attr.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclAccessPair.h"
19 #include "clang/AST/DeclBase.h"
20 #include "clang/AST/DeclCXX.h"
21 #include "clang/AST/DeclarationName.h"
22 #include "clang/AST/Expr.h"
23 #include "clang/AST/LambdaCapture.h"
24 #include "clang/AST/NestedNameSpecifier.h"
25 #include "clang/AST/TemplateBase.h"
26 #include "clang/AST/Type.h"
27 #include "clang/AST/TypeLoc.h"
28 #include "clang/Basic/LLVM.h"
29 #include "clang/Basic/OperatorKinds.h"
30 #include "clang/Basic/SourceLocation.h"
31 #include "clang/Basic/Specifiers.h"
32 #include "llvm/ADT/ArrayRef.h"
33 #include "llvm/Support/Casting.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include <cassert>
36 #include <cstddef>
37 #include <cstring>
38 #include <memory>
39 
40 using namespace clang;
41 
42 //===----------------------------------------------------------------------===//
43 //  Child Iterators for iterating over subexpressions/substatements
44 //===----------------------------------------------------------------------===//
45 
46 bool CXXOperatorCallExpr::isInfixBinaryOp() const {
47   // An infix binary operator is any operator with two arguments other than
48   // operator() and operator[]. Note that none of these operators can have
49   // default arguments, so it suffices to check the number of argument
50   // expressions.
51   if (getNumArgs() != 2)
52     return false;
53 
54   switch (getOperator()) {
55   case OO_Call: case OO_Subscript:
56     return false;
57   default:
58     return true;
59   }
60 }
61 
62 bool CXXTypeidExpr::isPotentiallyEvaluated() const {
63   if (isTypeOperand())
64     return false;
65 
66   // C++11 [expr.typeid]p3:
67   //   When typeid is applied to an expression other than a glvalue of
68   //   polymorphic class type, [...] the expression is an unevaluated operand.
69   const Expr *E = getExprOperand();
70   if (const CXXRecordDecl *RD = E->getType()->getAsCXXRecordDecl())
71     if (RD->isPolymorphic() && E->isGLValue())
72       return true;
73 
74   return false;
75 }
76 
77 QualType CXXTypeidExpr::getTypeOperand(ASTContext &Context) const {
78   assert(isTypeOperand() && "Cannot call getTypeOperand for typeid(expr)");
79   Qualifiers Quals;
80   return Context.getUnqualifiedArrayType(
81       Operand.get<TypeSourceInfo *>()->getType().getNonReferenceType(), Quals);
82 }
83 
84 QualType CXXUuidofExpr::getTypeOperand(ASTContext &Context) const {
85   assert(isTypeOperand() && "Cannot call getTypeOperand for __uuidof(expr)");
86   Qualifiers Quals;
87   return Context.getUnqualifiedArrayType(
88       Operand.get<TypeSourceInfo *>()->getType().getNonReferenceType(), Quals);
89 }
90 
91 // CXXScalarValueInitExpr
92 SourceLocation CXXScalarValueInitExpr::getLocStart() const {
93   return TypeInfo ? TypeInfo->getTypeLoc().getBeginLoc() : RParenLoc;
94 }
95 
96 // CXXNewExpr
97 CXXNewExpr::CXXNewExpr(const ASTContext &C, bool globalNew,
98                        FunctionDecl *operatorNew, FunctionDecl *operatorDelete,
99                        bool PassAlignment, bool usualArrayDeleteWantsSize,
100                        ArrayRef<Expr*> placementArgs,
101                        SourceRange typeIdParens, Expr *arraySize,
102                        InitializationStyle initializationStyle,
103                        Expr *initializer, QualType ty,
104                        TypeSourceInfo *allocatedTypeInfo,
105                        SourceRange Range, SourceRange directInitRange)
106     : Expr(CXXNewExprClass, ty, VK_RValue, OK_Ordinary, ty->isDependentType(),
107            ty->isDependentType(), ty->isInstantiationDependentType(),
108            ty->containsUnexpandedParameterPack()),
109       OperatorNew(operatorNew), OperatorDelete(operatorDelete),
110       AllocatedTypeInfo(allocatedTypeInfo), TypeIdParens(typeIdParens),
111       Range(Range), DirectInitRange(directInitRange), GlobalNew(globalNew),
112       PassAlignment(PassAlignment),
113       UsualArrayDeleteWantsSize(usualArrayDeleteWantsSize) {
114   assert((initializer != nullptr || initializationStyle == NoInit) &&
115          "Only NoInit can have no initializer.");
116   StoredInitializationStyle = initializer ? initializationStyle + 1 : 0;
117   AllocateArgsArray(C, arraySize != nullptr, placementArgs.size(),
118                     initializer != nullptr);
119   unsigned i = 0;
120   if (Array) {
121     if (arraySize->isInstantiationDependent())
122       ExprBits.InstantiationDependent = true;
123 
124     if (arraySize->containsUnexpandedParameterPack())
125       ExprBits.ContainsUnexpandedParameterPack = true;
126 
127     SubExprs[i++] = arraySize;
128   }
129 
130   if (initializer) {
131     if (initializer->isInstantiationDependent())
132       ExprBits.InstantiationDependent = true;
133 
134     if (initializer->containsUnexpandedParameterPack())
135       ExprBits.ContainsUnexpandedParameterPack = true;
136 
137     SubExprs[i++] = initializer;
138   }
139 
140   for (unsigned j = 0; j != placementArgs.size(); ++j) {
141     if (placementArgs[j]->isInstantiationDependent())
142       ExprBits.InstantiationDependent = true;
143     if (placementArgs[j]->containsUnexpandedParameterPack())
144       ExprBits.ContainsUnexpandedParameterPack = true;
145 
146     SubExprs[i++] = placementArgs[j];
147   }
148 
149   switch (getInitializationStyle()) {
150   case CallInit:
151     this->Range.setEnd(DirectInitRange.getEnd()); break;
152   case ListInit:
153     this->Range.setEnd(getInitializer()->getSourceRange().getEnd()); break;
154   default:
155     if (TypeIdParens.isValid())
156       this->Range.setEnd(TypeIdParens.getEnd());
157     break;
158   }
159 }
160 
161 void CXXNewExpr::AllocateArgsArray(const ASTContext &C, bool isArray,
162                                    unsigned numPlaceArgs, bool hasInitializer){
163   assert(SubExprs == nullptr && "SubExprs already allocated");
164   Array = isArray;
165   NumPlacementArgs = numPlaceArgs;
166 
167   unsigned TotalSize = Array + hasInitializer + NumPlacementArgs;
168   SubExprs = new (C) Stmt*[TotalSize];
169 }
170 
171 bool CXXNewExpr::shouldNullCheckAllocation(const ASTContext &Ctx) const {
172   return getOperatorNew()->getType()->castAs<FunctionProtoType>()
173                                           ->isNothrow() &&
174          !getOperatorNew()->isReservedGlobalPlacementOperator();
175 }
176 
177 // CXXDeleteExpr
178 QualType CXXDeleteExpr::getDestroyedType() const {
179   const Expr *Arg = getArgument();
180 
181   // For a destroying operator delete, we may have implicitly converted the
182   // pointer type to the type of the parameter of the 'operator delete'
183   // function.
184   while (const auto *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
185     if (ICE->getCastKind() == CK_DerivedToBase ||
186         ICE->getCastKind() == CK_UncheckedDerivedToBase ||
187         ICE->getCastKind() == CK_NoOp) {
188       assert((ICE->getCastKind() == CK_NoOp ||
189               getOperatorDelete()->isDestroyingOperatorDelete()) &&
190              "only a destroying operator delete can have a converted arg");
191       Arg = ICE->getSubExpr();
192     } else
193       break;
194   }
195 
196   // The type-to-delete may not be a pointer if it's a dependent type.
197   const QualType ArgType = Arg->getType();
198 
199   if (ArgType->isDependentType() && !ArgType->isPointerType())
200     return QualType();
201 
202   return ArgType->getAs<PointerType>()->getPointeeType();
203 }
204 
205 // CXXPseudoDestructorExpr
206 PseudoDestructorTypeStorage::PseudoDestructorTypeStorage(TypeSourceInfo *Info)
207     : Type(Info) {
208   Location = Info->getTypeLoc().getLocalSourceRange().getBegin();
209 }
210 
211 CXXPseudoDestructorExpr::CXXPseudoDestructorExpr(const ASTContext &Context,
212                 Expr *Base, bool isArrow, SourceLocation OperatorLoc,
213                 NestedNameSpecifierLoc QualifierLoc, TypeSourceInfo *ScopeType,
214                 SourceLocation ColonColonLoc, SourceLocation TildeLoc,
215                 PseudoDestructorTypeStorage DestroyedType)
216   : Expr(CXXPseudoDestructorExprClass,
217          Context.BoundMemberTy,
218          VK_RValue, OK_Ordinary,
219          /*isTypeDependent=*/(Base->isTypeDependent() ||
220            (DestroyedType.getTypeSourceInfo() &&
221             DestroyedType.getTypeSourceInfo()->getType()->isDependentType())),
222          /*isValueDependent=*/Base->isValueDependent(),
223          (Base->isInstantiationDependent() ||
224           (QualifierLoc &&
225            QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent()) ||
226           (ScopeType &&
227            ScopeType->getType()->isInstantiationDependentType()) ||
228           (DestroyedType.getTypeSourceInfo() &&
229            DestroyedType.getTypeSourceInfo()->getType()
230                                              ->isInstantiationDependentType())),
231          // ContainsUnexpandedParameterPack
232          (Base->containsUnexpandedParameterPack() ||
233           (QualifierLoc &&
234            QualifierLoc.getNestedNameSpecifier()
235                                         ->containsUnexpandedParameterPack()) ||
236           (ScopeType &&
237            ScopeType->getType()->containsUnexpandedParameterPack()) ||
238           (DestroyedType.getTypeSourceInfo() &&
239            DestroyedType.getTypeSourceInfo()->getType()
240                                    ->containsUnexpandedParameterPack()))),
241     Base(static_cast<Stmt *>(Base)), IsArrow(isArrow),
242     OperatorLoc(OperatorLoc), QualifierLoc(QualifierLoc),
243     ScopeType(ScopeType), ColonColonLoc(ColonColonLoc), TildeLoc(TildeLoc),
244     DestroyedType(DestroyedType) {}
245 
246 QualType CXXPseudoDestructorExpr::getDestroyedType() const {
247   if (TypeSourceInfo *TInfo = DestroyedType.getTypeSourceInfo())
248     return TInfo->getType();
249 
250   return QualType();
251 }
252 
253 SourceLocation CXXPseudoDestructorExpr::getLocEnd() const {
254   SourceLocation End = DestroyedType.getLocation();
255   if (TypeSourceInfo *TInfo = DestroyedType.getTypeSourceInfo())
256     End = TInfo->getTypeLoc().getLocalSourceRange().getEnd();
257   return End;
258 }
259 
260 // UnresolvedLookupExpr
261 UnresolvedLookupExpr *
262 UnresolvedLookupExpr::Create(const ASTContext &C,
263                              CXXRecordDecl *NamingClass,
264                              NestedNameSpecifierLoc QualifierLoc,
265                              SourceLocation TemplateKWLoc,
266                              const DeclarationNameInfo &NameInfo,
267                              bool ADL,
268                              const TemplateArgumentListInfo *Args,
269                              UnresolvedSetIterator Begin,
270                              UnresolvedSetIterator End) {
271   assert(Args || TemplateKWLoc.isValid());
272   unsigned num_args = Args ? Args->size() : 0;
273 
274   std::size_t Size =
275       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(1,
276                                                                       num_args);
277   void *Mem = C.Allocate(Size, alignof(UnresolvedLookupExpr));
278   return new (Mem) UnresolvedLookupExpr(C, NamingClass, QualifierLoc,
279                                         TemplateKWLoc, NameInfo,
280                                         ADL, /*Overload*/ true, Args,
281                                         Begin, End);
282 }
283 
284 UnresolvedLookupExpr *
285 UnresolvedLookupExpr::CreateEmpty(const ASTContext &C,
286                                   bool HasTemplateKWAndArgsInfo,
287                                   unsigned NumTemplateArgs) {
288   assert(NumTemplateArgs == 0 || HasTemplateKWAndArgsInfo);
289   std::size_t Size =
290       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
291           HasTemplateKWAndArgsInfo, NumTemplateArgs);
292   void *Mem = C.Allocate(Size, alignof(UnresolvedLookupExpr));
293   auto *E = new (Mem) UnresolvedLookupExpr(EmptyShell());
294   E->HasTemplateKWAndArgsInfo = HasTemplateKWAndArgsInfo;
295   return E;
296 }
297 
298 OverloadExpr::OverloadExpr(StmtClass K, const ASTContext &C,
299                            NestedNameSpecifierLoc QualifierLoc,
300                            SourceLocation TemplateKWLoc,
301                            const DeclarationNameInfo &NameInfo,
302                            const TemplateArgumentListInfo *TemplateArgs,
303                            UnresolvedSetIterator Begin,
304                            UnresolvedSetIterator End,
305                            bool KnownDependent,
306                            bool KnownInstantiationDependent,
307                            bool KnownContainsUnexpandedParameterPack)
308     : Expr(K, C.OverloadTy, VK_LValue, OK_Ordinary, KnownDependent,
309            KnownDependent,
310            (KnownInstantiationDependent ||
311             NameInfo.isInstantiationDependent() ||
312             (QualifierLoc &&
313             QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())),
314            (KnownContainsUnexpandedParameterPack ||
315             NameInfo.containsUnexpandedParameterPack() ||
316             (QualifierLoc &&
317              QualifierLoc.getNestedNameSpecifier()
318                                         ->containsUnexpandedParameterPack()))),
319       NameInfo(NameInfo), QualifierLoc(QualifierLoc), NumResults(End - Begin),
320       HasTemplateKWAndArgsInfo(TemplateArgs != nullptr ||
321                                TemplateKWLoc.isValid()) {
322   NumResults = End - Begin;
323   if (NumResults) {
324     // Determine whether this expression is type-dependent.
325     for (UnresolvedSetImpl::const_iterator I = Begin; I != End; ++I) {
326       if ((*I)->getDeclContext()->isDependentContext() ||
327           isa<UnresolvedUsingValueDecl>(*I)) {
328         ExprBits.TypeDependent = true;
329         ExprBits.ValueDependent = true;
330         ExprBits.InstantiationDependent = true;
331       }
332     }
333 
334     Results = static_cast<DeclAccessPair *>(C.Allocate(
335         sizeof(DeclAccessPair) * NumResults, alignof(DeclAccessPair)));
336     memcpy(Results, Begin.I, NumResults * sizeof(DeclAccessPair));
337   }
338 
339   // If we have explicit template arguments, check for dependent
340   // template arguments and whether they contain any unexpanded pack
341   // expansions.
342   if (TemplateArgs) {
343     bool Dependent = false;
344     bool InstantiationDependent = false;
345     bool ContainsUnexpandedParameterPack = false;
346     getTrailingASTTemplateKWAndArgsInfo()->initializeFrom(
347         TemplateKWLoc, *TemplateArgs, getTrailingTemplateArgumentLoc(),
348         Dependent, InstantiationDependent, ContainsUnexpandedParameterPack);
349 
350     if (Dependent) {
351       ExprBits.TypeDependent = true;
352       ExprBits.ValueDependent = true;
353     }
354     if (InstantiationDependent)
355       ExprBits.InstantiationDependent = true;
356     if (ContainsUnexpandedParameterPack)
357       ExprBits.ContainsUnexpandedParameterPack = true;
358   } else if (TemplateKWLoc.isValid()) {
359     getTrailingASTTemplateKWAndArgsInfo()->initializeFrom(TemplateKWLoc);
360   }
361 
362   if (isTypeDependent())
363     setType(C.DependentTy);
364 }
365 
366 void OverloadExpr::initializeResults(const ASTContext &C,
367                                      UnresolvedSetIterator Begin,
368                                      UnresolvedSetIterator End) {
369   assert(!Results && "Results already initialized!");
370   NumResults = End - Begin;
371   if (NumResults) {
372     Results = static_cast<DeclAccessPair *>(
373         C.Allocate(sizeof(DeclAccessPair) * NumResults,
374 
375                    alignof(DeclAccessPair)));
376     memcpy(Results, Begin.I, NumResults * sizeof(DeclAccessPair));
377   }
378 }
379 
380 CXXRecordDecl *OverloadExpr::getNamingClass() const {
381   if (isa<UnresolvedLookupExpr>(this))
382     return cast<UnresolvedLookupExpr>(this)->getNamingClass();
383   else
384     return cast<UnresolvedMemberExpr>(this)->getNamingClass();
385 }
386 
387 // DependentScopeDeclRefExpr
388 DependentScopeDeclRefExpr::DependentScopeDeclRefExpr(QualType T,
389                             NestedNameSpecifierLoc QualifierLoc,
390                             SourceLocation TemplateKWLoc,
391                             const DeclarationNameInfo &NameInfo,
392                             const TemplateArgumentListInfo *Args)
393   : Expr(DependentScopeDeclRefExprClass, T, VK_LValue, OK_Ordinary,
394          true, true,
395          (NameInfo.isInstantiationDependent() ||
396           (QualifierLoc &&
397            QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())),
398          (NameInfo.containsUnexpandedParameterPack() ||
399           (QualifierLoc &&
400            QualifierLoc.getNestedNameSpecifier()
401                             ->containsUnexpandedParameterPack()))),
402     QualifierLoc(QualifierLoc), NameInfo(NameInfo),
403     HasTemplateKWAndArgsInfo(Args != nullptr || TemplateKWLoc.isValid())
404 {
405   if (Args) {
406     bool Dependent = true;
407     bool InstantiationDependent = true;
408     bool ContainsUnexpandedParameterPack
409       = ExprBits.ContainsUnexpandedParameterPack;
410     getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
411         TemplateKWLoc, *Args, getTrailingObjects<TemplateArgumentLoc>(),
412         Dependent, InstantiationDependent, ContainsUnexpandedParameterPack);
413     ExprBits.ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
414   } else if (TemplateKWLoc.isValid()) {
415     getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
416         TemplateKWLoc);
417   }
418 }
419 
420 DependentScopeDeclRefExpr *
421 DependentScopeDeclRefExpr::Create(const ASTContext &C,
422                                   NestedNameSpecifierLoc QualifierLoc,
423                                   SourceLocation TemplateKWLoc,
424                                   const DeclarationNameInfo &NameInfo,
425                                   const TemplateArgumentListInfo *Args) {
426   assert(QualifierLoc && "should be created for dependent qualifiers");
427   bool HasTemplateKWAndArgsInfo = Args || TemplateKWLoc.isValid();
428   std::size_t Size =
429       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
430           HasTemplateKWAndArgsInfo, Args ? Args->size() : 0);
431   void *Mem = C.Allocate(Size);
432   return new (Mem) DependentScopeDeclRefExpr(C.DependentTy, QualifierLoc,
433                                              TemplateKWLoc, NameInfo, Args);
434 }
435 
436 DependentScopeDeclRefExpr *
437 DependentScopeDeclRefExpr::CreateEmpty(const ASTContext &C,
438                                        bool HasTemplateKWAndArgsInfo,
439                                        unsigned NumTemplateArgs) {
440   assert(NumTemplateArgs == 0 || HasTemplateKWAndArgsInfo);
441   std::size_t Size =
442       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
443           HasTemplateKWAndArgsInfo, NumTemplateArgs);
444   void *Mem = C.Allocate(Size);
445   auto *E =
446       new (Mem) DependentScopeDeclRefExpr(QualType(), NestedNameSpecifierLoc(),
447                                           SourceLocation(),
448                                           DeclarationNameInfo(), nullptr);
449   E->HasTemplateKWAndArgsInfo = HasTemplateKWAndArgsInfo;
450   return E;
451 }
452 
453 SourceLocation CXXConstructExpr::getLocStart() const {
454   if (isa<CXXTemporaryObjectExpr>(this))
455     return cast<CXXTemporaryObjectExpr>(this)->getLocStart();
456   return Loc;
457 }
458 
459 SourceLocation CXXConstructExpr::getLocEnd() const {
460   if (isa<CXXTemporaryObjectExpr>(this))
461     return cast<CXXTemporaryObjectExpr>(this)->getLocEnd();
462 
463   if (ParenOrBraceRange.isValid())
464     return ParenOrBraceRange.getEnd();
465 
466   SourceLocation End = Loc;
467   for (unsigned I = getNumArgs(); I > 0; --I) {
468     const Expr *Arg = getArg(I-1);
469     if (!Arg->isDefaultArgument()) {
470       SourceLocation NewEnd = Arg->getLocEnd();
471       if (NewEnd.isValid()) {
472         End = NewEnd;
473         break;
474       }
475     }
476   }
477 
478   return End;
479 }
480 
481 SourceRange CXXOperatorCallExpr::getSourceRangeImpl() const {
482   OverloadedOperatorKind Kind = getOperator();
483   if (Kind == OO_PlusPlus || Kind == OO_MinusMinus) {
484     if (getNumArgs() == 1)
485       // Prefix operator
486       return SourceRange(getOperatorLoc(), getArg(0)->getLocEnd());
487     else
488       // Postfix operator
489       return SourceRange(getArg(0)->getLocStart(), getOperatorLoc());
490   } else if (Kind == OO_Arrow) {
491     return getArg(0)->getSourceRange();
492   } else if (Kind == OO_Call) {
493     return SourceRange(getArg(0)->getLocStart(), getRParenLoc());
494   } else if (Kind == OO_Subscript) {
495     return SourceRange(getArg(0)->getLocStart(), getRParenLoc());
496   } else if (getNumArgs() == 1) {
497     return SourceRange(getOperatorLoc(), getArg(0)->getLocEnd());
498   } else if (getNumArgs() == 2) {
499     return SourceRange(getArg(0)->getLocStart(), getArg(1)->getLocEnd());
500   } else {
501     return getOperatorLoc();
502   }
503 }
504 
505 Expr *CXXMemberCallExpr::getImplicitObjectArgument() const {
506   const Expr *Callee = getCallee()->IgnoreParens();
507   if (const auto *MemExpr = dyn_cast<MemberExpr>(Callee))
508     return MemExpr->getBase();
509   if (const auto *BO = dyn_cast<BinaryOperator>(Callee))
510     if (BO->getOpcode() == BO_PtrMemD || BO->getOpcode() == BO_PtrMemI)
511       return BO->getLHS();
512 
513   // FIXME: Will eventually need to cope with member pointers.
514   return nullptr;
515 }
516 
517 CXXMethodDecl *CXXMemberCallExpr::getMethodDecl() const {
518   if (const auto *MemExpr = dyn_cast<MemberExpr>(getCallee()->IgnoreParens()))
519     return cast<CXXMethodDecl>(MemExpr->getMemberDecl());
520 
521   // FIXME: Will eventually need to cope with member pointers.
522   return nullptr;
523 }
524 
525 CXXRecordDecl *CXXMemberCallExpr::getRecordDecl() const {
526   Expr* ThisArg = getImplicitObjectArgument();
527   if (!ThisArg)
528     return nullptr;
529 
530   if (ThisArg->getType()->isAnyPointerType())
531     return ThisArg->getType()->getPointeeType()->getAsCXXRecordDecl();
532 
533   return ThisArg->getType()->getAsCXXRecordDecl();
534 }
535 
536 //===----------------------------------------------------------------------===//
537 //  Named casts
538 //===----------------------------------------------------------------------===//
539 
540 /// getCastName - Get the name of the C++ cast being used, e.g.,
541 /// "static_cast", "dynamic_cast", "reinterpret_cast", or
542 /// "const_cast". The returned pointer must not be freed.
543 const char *CXXNamedCastExpr::getCastName() const {
544   switch (getStmtClass()) {
545   case CXXStaticCastExprClass:      return "static_cast";
546   case CXXDynamicCastExprClass:     return "dynamic_cast";
547   case CXXReinterpretCastExprClass: return "reinterpret_cast";
548   case CXXConstCastExprClass:       return "const_cast";
549   default:                          return "<invalid cast>";
550   }
551 }
552 
553 CXXStaticCastExpr *CXXStaticCastExpr::Create(const ASTContext &C, QualType T,
554                                              ExprValueKind VK,
555                                              CastKind K, Expr *Op,
556                                              const CXXCastPath *BasePath,
557                                              TypeSourceInfo *WrittenTy,
558                                              SourceLocation L,
559                                              SourceLocation RParenLoc,
560                                              SourceRange AngleBrackets) {
561   unsigned PathSize = (BasePath ? BasePath->size() : 0);
562   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
563   auto *E =
564       new (Buffer) CXXStaticCastExpr(T, VK, K, Op, PathSize, WrittenTy, L,
565                                      RParenLoc, AngleBrackets);
566   if (PathSize)
567     std::uninitialized_copy_n(BasePath->data(), BasePath->size(),
568                               E->getTrailingObjects<CXXBaseSpecifier *>());
569   return E;
570 }
571 
572 CXXStaticCastExpr *CXXStaticCastExpr::CreateEmpty(const ASTContext &C,
573                                                   unsigned PathSize) {
574   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
575   return new (Buffer) CXXStaticCastExpr(EmptyShell(), PathSize);
576 }
577 
578 CXXDynamicCastExpr *CXXDynamicCastExpr::Create(const ASTContext &C, QualType T,
579                                                ExprValueKind VK,
580                                                CastKind K, Expr *Op,
581                                                const CXXCastPath *BasePath,
582                                                TypeSourceInfo *WrittenTy,
583                                                SourceLocation L,
584                                                SourceLocation RParenLoc,
585                                                SourceRange AngleBrackets) {
586   unsigned PathSize = (BasePath ? BasePath->size() : 0);
587   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
588   auto *E =
589       new (Buffer) CXXDynamicCastExpr(T, VK, K, Op, PathSize, WrittenTy, L,
590                                       RParenLoc, AngleBrackets);
591   if (PathSize)
592     std::uninitialized_copy_n(BasePath->data(), BasePath->size(),
593                               E->getTrailingObjects<CXXBaseSpecifier *>());
594   return E;
595 }
596 
597 CXXDynamicCastExpr *CXXDynamicCastExpr::CreateEmpty(const ASTContext &C,
598                                                     unsigned PathSize) {
599   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
600   return new (Buffer) CXXDynamicCastExpr(EmptyShell(), PathSize);
601 }
602 
603 /// isAlwaysNull - Return whether the result of the dynamic_cast is proven
604 /// to always be null. For example:
605 ///
606 /// struct A { };
607 /// struct B final : A { };
608 /// struct C { };
609 ///
610 /// C *f(B* b) { return dynamic_cast<C*>(b); }
611 bool CXXDynamicCastExpr::isAlwaysNull() const
612 {
613   QualType SrcType = getSubExpr()->getType();
614   QualType DestType = getType();
615 
616   if (const auto *SrcPTy = SrcType->getAs<PointerType>()) {
617     SrcType = SrcPTy->getPointeeType();
618     DestType = DestType->castAs<PointerType>()->getPointeeType();
619   }
620 
621   if (DestType->isVoidType())
622     return false;
623 
624   const auto *SrcRD =
625       cast<CXXRecordDecl>(SrcType->castAs<RecordType>()->getDecl());
626 
627   if (!SrcRD->hasAttr<FinalAttr>())
628     return false;
629 
630   const auto *DestRD =
631       cast<CXXRecordDecl>(DestType->castAs<RecordType>()->getDecl());
632 
633   return !DestRD->isDerivedFrom(SrcRD);
634 }
635 
636 CXXReinterpretCastExpr *
637 CXXReinterpretCastExpr::Create(const ASTContext &C, QualType T,
638                                ExprValueKind VK, CastKind K, Expr *Op,
639                                const CXXCastPath *BasePath,
640                                TypeSourceInfo *WrittenTy, SourceLocation L,
641                                SourceLocation RParenLoc,
642                                SourceRange AngleBrackets) {
643   unsigned PathSize = (BasePath ? BasePath->size() : 0);
644   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
645   auto *E =
646       new (Buffer) CXXReinterpretCastExpr(T, VK, K, Op, PathSize, WrittenTy, L,
647                                           RParenLoc, AngleBrackets);
648   if (PathSize)
649     std::uninitialized_copy_n(BasePath->data(), BasePath->size(),
650                               E->getTrailingObjects<CXXBaseSpecifier *>());
651   return E;
652 }
653 
654 CXXReinterpretCastExpr *
655 CXXReinterpretCastExpr::CreateEmpty(const ASTContext &C, unsigned PathSize) {
656   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
657   return new (Buffer) CXXReinterpretCastExpr(EmptyShell(), PathSize);
658 }
659 
660 CXXConstCastExpr *CXXConstCastExpr::Create(const ASTContext &C, QualType T,
661                                            ExprValueKind VK, Expr *Op,
662                                            TypeSourceInfo *WrittenTy,
663                                            SourceLocation L,
664                                            SourceLocation RParenLoc,
665                                            SourceRange AngleBrackets) {
666   return new (C) CXXConstCastExpr(T, VK, Op, WrittenTy, L, RParenLoc, AngleBrackets);
667 }
668 
669 CXXConstCastExpr *CXXConstCastExpr::CreateEmpty(const ASTContext &C) {
670   return new (C) CXXConstCastExpr(EmptyShell());
671 }
672 
673 CXXFunctionalCastExpr *
674 CXXFunctionalCastExpr::Create(const ASTContext &C, QualType T, ExprValueKind VK,
675                               TypeSourceInfo *Written, CastKind K, Expr *Op,
676                               const CXXCastPath *BasePath,
677                               SourceLocation L, SourceLocation R) {
678   unsigned PathSize = (BasePath ? BasePath->size() : 0);
679   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
680   auto *E =
681       new (Buffer) CXXFunctionalCastExpr(T, VK, Written, K, Op, PathSize, L, R);
682   if (PathSize)
683     std::uninitialized_copy_n(BasePath->data(), BasePath->size(),
684                               E->getTrailingObjects<CXXBaseSpecifier *>());
685   return E;
686 }
687 
688 CXXFunctionalCastExpr *
689 CXXFunctionalCastExpr::CreateEmpty(const ASTContext &C, unsigned PathSize) {
690   void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
691   return new (Buffer) CXXFunctionalCastExpr(EmptyShell(), PathSize);
692 }
693 
694 SourceLocation CXXFunctionalCastExpr::getLocStart() const {
695   return getTypeInfoAsWritten()->getTypeLoc().getLocStart();
696 }
697 
698 SourceLocation CXXFunctionalCastExpr::getLocEnd() const {
699   return RParenLoc.isValid() ? RParenLoc : getSubExpr()->getLocEnd();
700 }
701 
702 UserDefinedLiteral::LiteralOperatorKind
703 UserDefinedLiteral::getLiteralOperatorKind() const {
704   if (getNumArgs() == 0)
705     return LOK_Template;
706   if (getNumArgs() == 2)
707     return LOK_String;
708 
709   assert(getNumArgs() == 1 && "unexpected #args in literal operator call");
710   QualType ParamTy =
711     cast<FunctionDecl>(getCalleeDecl())->getParamDecl(0)->getType();
712   if (ParamTy->isPointerType())
713     return LOK_Raw;
714   if (ParamTy->isAnyCharacterType())
715     return LOK_Character;
716   if (ParamTy->isIntegerType())
717     return LOK_Integer;
718   if (ParamTy->isFloatingType())
719     return LOK_Floating;
720 
721   llvm_unreachable("unknown kind of literal operator");
722 }
723 
724 Expr *UserDefinedLiteral::getCookedLiteral() {
725 #ifndef NDEBUG
726   LiteralOperatorKind LOK = getLiteralOperatorKind();
727   assert(LOK != LOK_Template && LOK != LOK_Raw && "not a cooked literal");
728 #endif
729   return getArg(0);
730 }
731 
732 const IdentifierInfo *UserDefinedLiteral::getUDSuffix() const {
733   return cast<FunctionDecl>(getCalleeDecl())->getLiteralIdentifier();
734 }
735 
736 CXXDefaultInitExpr::CXXDefaultInitExpr(const ASTContext &C, SourceLocation Loc,
737                                        FieldDecl *Field, QualType T)
738     : Expr(CXXDefaultInitExprClass, T.getNonLValueExprType(C),
739            T->isLValueReferenceType() ? VK_LValue : T->isRValueReferenceType()
740                                                         ? VK_XValue
741                                                         : VK_RValue,
742            /*FIXME*/ OK_Ordinary, false, false, false, false),
743       Field(Field), Loc(Loc) {
744   assert(Field->hasInClassInitializer());
745 }
746 
747 CXXTemporary *CXXTemporary::Create(const ASTContext &C,
748                                    const CXXDestructorDecl *Destructor) {
749   return new (C) CXXTemporary(Destructor);
750 }
751 
752 CXXBindTemporaryExpr *CXXBindTemporaryExpr::Create(const ASTContext &C,
753                                                    CXXTemporary *Temp,
754                                                    Expr* SubExpr) {
755   assert((SubExpr->getType()->isRecordType() ||
756           SubExpr->getType()->isArrayType()) &&
757          "Expression bound to a temporary must have record or array type!");
758 
759   return new (C) CXXBindTemporaryExpr(Temp, SubExpr);
760 }
761 
762 CXXTemporaryObjectExpr::CXXTemporaryObjectExpr(const ASTContext &C,
763                                                CXXConstructorDecl *Cons,
764                                                QualType Type,
765                                                TypeSourceInfo *TSI,
766                                                ArrayRef<Expr*> Args,
767                                                SourceRange ParenOrBraceRange,
768                                                bool HadMultipleCandidates,
769                                                bool ListInitialization,
770                                                bool StdInitListInitialization,
771                                                bool ZeroInitialization)
772     : CXXConstructExpr(C, CXXTemporaryObjectExprClass, Type,
773                        TSI->getTypeLoc().getBeginLoc(), Cons, false, Args,
774                        HadMultipleCandidates, ListInitialization,
775                        StdInitListInitialization,  ZeroInitialization,
776                        CXXConstructExpr::CK_Complete, ParenOrBraceRange),
777       Type(TSI) {}
778 
779 SourceLocation CXXTemporaryObjectExpr::getLocStart() const {
780   return Type->getTypeLoc().getBeginLoc();
781 }
782 
783 SourceLocation CXXTemporaryObjectExpr::getLocEnd() const {
784   SourceLocation Loc = getParenOrBraceRange().getEnd();
785   if (Loc.isInvalid() && getNumArgs())
786     Loc = getArg(getNumArgs()-1)->getLocEnd();
787   return Loc;
788 }
789 
790 CXXConstructExpr *CXXConstructExpr::Create(const ASTContext &C, QualType T,
791                                            SourceLocation Loc,
792                                            CXXConstructorDecl *Ctor,
793                                            bool Elidable,
794                                            ArrayRef<Expr*> Args,
795                                            bool HadMultipleCandidates,
796                                            bool ListInitialization,
797                                            bool StdInitListInitialization,
798                                            bool ZeroInitialization,
799                                            ConstructionKind ConstructKind,
800                                            SourceRange ParenOrBraceRange) {
801   return new (C) CXXConstructExpr(C, CXXConstructExprClass, T, Loc,
802                                   Ctor, Elidable, Args,
803                                   HadMultipleCandidates, ListInitialization,
804                                   StdInitListInitialization,
805                                   ZeroInitialization, ConstructKind,
806                                   ParenOrBraceRange);
807 }
808 
809 CXXConstructExpr::CXXConstructExpr(const ASTContext &C, StmtClass SC,
810                                    QualType T, SourceLocation Loc,
811                                    CXXConstructorDecl *Ctor,
812                                    bool Elidable,
813                                    ArrayRef<Expr*> Args,
814                                    bool HadMultipleCandidates,
815                                    bool ListInitialization,
816                                    bool StdInitListInitialization,
817                                    bool ZeroInitialization,
818                                    ConstructionKind ConstructKind,
819                                    SourceRange ParenOrBraceRange)
820     : Expr(SC, T, VK_RValue, OK_Ordinary,
821            T->isDependentType(), T->isDependentType(),
822            T->isInstantiationDependentType(),
823            T->containsUnexpandedParameterPack()),
824       Constructor(Ctor), Loc(Loc), ParenOrBraceRange(ParenOrBraceRange),
825       NumArgs(Args.size()), Elidable(Elidable),
826       HadMultipleCandidates(HadMultipleCandidates),
827       ListInitialization(ListInitialization),
828       StdInitListInitialization(StdInitListInitialization),
829       ZeroInitialization(ZeroInitialization), ConstructKind(ConstructKind) {
830   if (NumArgs) {
831     this->Args = new (C) Stmt*[Args.size()];
832 
833     for (unsigned i = 0; i != Args.size(); ++i) {
834       assert(Args[i] && "NULL argument in CXXConstructExpr");
835 
836       if (Args[i]->isValueDependent())
837         ExprBits.ValueDependent = true;
838       if (Args[i]->isInstantiationDependent())
839         ExprBits.InstantiationDependent = true;
840       if (Args[i]->containsUnexpandedParameterPack())
841         ExprBits.ContainsUnexpandedParameterPack = true;
842 
843       this->Args[i] = Args[i];
844     }
845   }
846 }
847 
848 LambdaCapture::LambdaCapture(SourceLocation Loc, bool Implicit,
849                              LambdaCaptureKind Kind, VarDecl *Var,
850                              SourceLocation EllipsisLoc)
851     : DeclAndBits(Var, 0), Loc(Loc), EllipsisLoc(EllipsisLoc) {
852   unsigned Bits = 0;
853   if (Implicit)
854     Bits |= Capture_Implicit;
855 
856   switch (Kind) {
857   case LCK_StarThis:
858     Bits |= Capture_ByCopy;
859     LLVM_FALLTHROUGH;
860   case LCK_This:
861     assert(!Var && "'this' capture cannot have a variable!");
862     Bits |= Capture_This;
863     break;
864 
865   case LCK_ByCopy:
866     Bits |= Capture_ByCopy;
867     LLVM_FALLTHROUGH;
868   case LCK_ByRef:
869     assert(Var && "capture must have a variable!");
870     break;
871   case LCK_VLAType:
872     assert(!Var && "VLA type capture cannot have a variable!");
873     break;
874   }
875   DeclAndBits.setInt(Bits);
876 }
877 
878 LambdaCaptureKind LambdaCapture::getCaptureKind() const {
879   if (capturesVLAType())
880     return LCK_VLAType;
881   bool CapByCopy = DeclAndBits.getInt() & Capture_ByCopy;
882   if (capturesThis())
883     return CapByCopy ? LCK_StarThis : LCK_This;
884   return CapByCopy ? LCK_ByCopy : LCK_ByRef;
885 }
886 
887 LambdaExpr::LambdaExpr(QualType T, SourceRange IntroducerRange,
888                        LambdaCaptureDefault CaptureDefault,
889                        SourceLocation CaptureDefaultLoc,
890                        ArrayRef<LambdaCapture> Captures, bool ExplicitParams,
891                        bool ExplicitResultType, ArrayRef<Expr *> CaptureInits,
892                        SourceLocation ClosingBrace,
893                        bool ContainsUnexpandedParameterPack)
894     : Expr(LambdaExprClass, T, VK_RValue, OK_Ordinary, T->isDependentType(),
895            T->isDependentType(), T->isDependentType(),
896            ContainsUnexpandedParameterPack),
897       IntroducerRange(IntroducerRange), CaptureDefaultLoc(CaptureDefaultLoc),
898       NumCaptures(Captures.size()), CaptureDefault(CaptureDefault),
899       ExplicitParams(ExplicitParams), ExplicitResultType(ExplicitResultType),
900       ClosingBrace(ClosingBrace) {
901   assert(CaptureInits.size() == Captures.size() && "Wrong number of arguments");
902   CXXRecordDecl *Class = getLambdaClass();
903   CXXRecordDecl::LambdaDefinitionData &Data = Class->getLambdaData();
904 
905   // FIXME: Propagate "has unexpanded parameter pack" bit.
906 
907   // Copy captures.
908   const ASTContext &Context = Class->getASTContext();
909   Data.NumCaptures = NumCaptures;
910   Data.NumExplicitCaptures = 0;
911   Data.Captures =
912       (LambdaCapture *)Context.Allocate(sizeof(LambdaCapture) * NumCaptures);
913   LambdaCapture *ToCapture = Data.Captures;
914   for (unsigned I = 0, N = Captures.size(); I != N; ++I) {
915     if (Captures[I].isExplicit())
916       ++Data.NumExplicitCaptures;
917 
918     *ToCapture++ = Captures[I];
919   }
920 
921   // Copy initialization expressions for the non-static data members.
922   Stmt **Stored = getStoredStmts();
923   for (unsigned I = 0, N = CaptureInits.size(); I != N; ++I)
924     *Stored++ = CaptureInits[I];
925 
926   // Copy the body of the lambda.
927   *Stored++ = getCallOperator()->getBody();
928 }
929 
930 LambdaExpr *LambdaExpr::Create(
931     const ASTContext &Context, CXXRecordDecl *Class,
932     SourceRange IntroducerRange, LambdaCaptureDefault CaptureDefault,
933     SourceLocation CaptureDefaultLoc, ArrayRef<LambdaCapture> Captures,
934     bool ExplicitParams, bool ExplicitResultType, ArrayRef<Expr *> CaptureInits,
935     SourceLocation ClosingBrace, bool ContainsUnexpandedParameterPack) {
936   // Determine the type of the expression (i.e., the type of the
937   // function object we're creating).
938   QualType T = Context.getTypeDeclType(Class);
939 
940   unsigned Size = totalSizeToAlloc<Stmt *>(Captures.size() + 1);
941   void *Mem = Context.Allocate(Size);
942   return new (Mem)
943       LambdaExpr(T, IntroducerRange, CaptureDefault, CaptureDefaultLoc,
944                  Captures, ExplicitParams, ExplicitResultType, CaptureInits,
945                  ClosingBrace, ContainsUnexpandedParameterPack);
946 }
947 
948 LambdaExpr *LambdaExpr::CreateDeserialized(const ASTContext &C,
949                                            unsigned NumCaptures) {
950   unsigned Size = totalSizeToAlloc<Stmt *>(NumCaptures + 1);
951   void *Mem = C.Allocate(Size);
952   return new (Mem) LambdaExpr(EmptyShell(), NumCaptures);
953 }
954 
955 bool LambdaExpr::isInitCapture(const LambdaCapture *C) const {
956   return (C->capturesVariable() && C->getCapturedVar()->isInitCapture() &&
957           (getCallOperator() == C->getCapturedVar()->getDeclContext()));
958 }
959 
960 LambdaExpr::capture_iterator LambdaExpr::capture_begin() const {
961   return getLambdaClass()->getLambdaData().Captures;
962 }
963 
964 LambdaExpr::capture_iterator LambdaExpr::capture_end() const {
965   return capture_begin() + NumCaptures;
966 }
967 
968 LambdaExpr::capture_range LambdaExpr::captures() const {
969   return capture_range(capture_begin(), capture_end());
970 }
971 
972 LambdaExpr::capture_iterator LambdaExpr::explicit_capture_begin() const {
973   return capture_begin();
974 }
975 
976 LambdaExpr::capture_iterator LambdaExpr::explicit_capture_end() const {
977   struct CXXRecordDecl::LambdaDefinitionData &Data
978     = getLambdaClass()->getLambdaData();
979   return Data.Captures + Data.NumExplicitCaptures;
980 }
981 
982 LambdaExpr::capture_range LambdaExpr::explicit_captures() const {
983   return capture_range(explicit_capture_begin(), explicit_capture_end());
984 }
985 
986 LambdaExpr::capture_iterator LambdaExpr::implicit_capture_begin() const {
987   return explicit_capture_end();
988 }
989 
990 LambdaExpr::capture_iterator LambdaExpr::implicit_capture_end() const {
991   return capture_end();
992 }
993 
994 LambdaExpr::capture_range LambdaExpr::implicit_captures() const {
995   return capture_range(implicit_capture_begin(), implicit_capture_end());
996 }
997 
998 CXXRecordDecl *LambdaExpr::getLambdaClass() const {
999   return getType()->getAsCXXRecordDecl();
1000 }
1001 
1002 CXXMethodDecl *LambdaExpr::getCallOperator() const {
1003   CXXRecordDecl *Record = getLambdaClass();
1004   return Record->getLambdaCallOperator();
1005 }
1006 
1007 TemplateParameterList *LambdaExpr::getTemplateParameterList() const {
1008   CXXRecordDecl *Record = getLambdaClass();
1009   return Record->getGenericLambdaTemplateParameterList();
1010 
1011 }
1012 
1013 CompoundStmt *LambdaExpr::getBody() const {
1014   // FIXME: this mutation in getBody is bogus. It should be
1015   // initialized in ASTStmtReader::VisitLambdaExpr, but for reasons I
1016   // don't understand, that doesn't work.
1017   if (!getStoredStmts()[NumCaptures])
1018     *const_cast<Stmt **>(&getStoredStmts()[NumCaptures]) =
1019         getCallOperator()->getBody();
1020 
1021   return static_cast<CompoundStmt *>(getStoredStmts()[NumCaptures]);
1022 }
1023 
1024 bool LambdaExpr::isMutable() const {
1025   return !getCallOperator()->isConst();
1026 }
1027 
1028 ExprWithCleanups::ExprWithCleanups(Expr *subexpr,
1029                                    bool CleanupsHaveSideEffects,
1030                                    ArrayRef<CleanupObject> objects)
1031     : Expr(ExprWithCleanupsClass, subexpr->getType(),
1032            subexpr->getValueKind(), subexpr->getObjectKind(),
1033            subexpr->isTypeDependent(), subexpr->isValueDependent(),
1034            subexpr->isInstantiationDependent(),
1035            subexpr->containsUnexpandedParameterPack()),
1036       SubExpr(subexpr) {
1037   ExprWithCleanupsBits.CleanupsHaveSideEffects = CleanupsHaveSideEffects;
1038   ExprWithCleanupsBits.NumObjects = objects.size();
1039   for (unsigned i = 0, e = objects.size(); i != e; ++i)
1040     getTrailingObjects<CleanupObject>()[i] = objects[i];
1041 }
1042 
1043 ExprWithCleanups *ExprWithCleanups::Create(const ASTContext &C, Expr *subexpr,
1044                                            bool CleanupsHaveSideEffects,
1045                                            ArrayRef<CleanupObject> objects) {
1046   void *buffer = C.Allocate(totalSizeToAlloc<CleanupObject>(objects.size()),
1047                             alignof(ExprWithCleanups));
1048   return new (buffer)
1049       ExprWithCleanups(subexpr, CleanupsHaveSideEffects, objects);
1050 }
1051 
1052 ExprWithCleanups::ExprWithCleanups(EmptyShell empty, unsigned numObjects)
1053     : Expr(ExprWithCleanupsClass, empty) {
1054   ExprWithCleanupsBits.NumObjects = numObjects;
1055 }
1056 
1057 ExprWithCleanups *ExprWithCleanups::Create(const ASTContext &C,
1058                                            EmptyShell empty,
1059                                            unsigned numObjects) {
1060   void *buffer = C.Allocate(totalSizeToAlloc<CleanupObject>(numObjects),
1061                             alignof(ExprWithCleanups));
1062   return new (buffer) ExprWithCleanups(empty, numObjects);
1063 }
1064 
1065 CXXUnresolvedConstructExpr::CXXUnresolvedConstructExpr(TypeSourceInfo *Type,
1066                                                  SourceLocation LParenLoc,
1067                                                  ArrayRef<Expr*> Args,
1068                                                  SourceLocation RParenLoc)
1069     : Expr(CXXUnresolvedConstructExprClass,
1070            Type->getType().getNonReferenceType(),
1071            (Type->getType()->isLValueReferenceType()
1072                 ? VK_LValue
1073                 : Type->getType()->isRValueReferenceType() ? VK_XValue
1074                                                            : VK_RValue),
1075            OK_Ordinary,
1076            Type->getType()->isDependentType() ||
1077                Type->getType()->getContainedDeducedType(),
1078            true, true, Type->getType()->containsUnexpandedParameterPack()),
1079       Type(Type), LParenLoc(LParenLoc), RParenLoc(RParenLoc),
1080       NumArgs(Args.size()) {
1081   auto **StoredArgs = getTrailingObjects<Expr *>();
1082   for (unsigned I = 0; I != Args.size(); ++I) {
1083     if (Args[I]->containsUnexpandedParameterPack())
1084       ExprBits.ContainsUnexpandedParameterPack = true;
1085 
1086     StoredArgs[I] = Args[I];
1087   }
1088 }
1089 
1090 CXXUnresolvedConstructExpr *
1091 CXXUnresolvedConstructExpr::Create(const ASTContext &C,
1092                                    TypeSourceInfo *Type,
1093                                    SourceLocation LParenLoc,
1094                                    ArrayRef<Expr*> Args,
1095                                    SourceLocation RParenLoc) {
1096   void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(Args.size()));
1097   return new (Mem) CXXUnresolvedConstructExpr(Type, LParenLoc, Args, RParenLoc);
1098 }
1099 
1100 CXXUnresolvedConstructExpr *
1101 CXXUnresolvedConstructExpr::CreateEmpty(const ASTContext &C, unsigned NumArgs) {
1102   Stmt::EmptyShell Empty;
1103   void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(NumArgs));
1104   return new (Mem) CXXUnresolvedConstructExpr(Empty, NumArgs);
1105 }
1106 
1107 SourceLocation CXXUnresolvedConstructExpr::getLocStart() const {
1108   return Type->getTypeLoc().getBeginLoc();
1109 }
1110 
1111 CXXDependentScopeMemberExpr::CXXDependentScopeMemberExpr(
1112     const ASTContext &C, Expr *Base, QualType BaseType, bool IsArrow,
1113     SourceLocation OperatorLoc, NestedNameSpecifierLoc QualifierLoc,
1114     SourceLocation TemplateKWLoc, NamedDecl *FirstQualifierFoundInScope,
1115     DeclarationNameInfo MemberNameInfo,
1116     const TemplateArgumentListInfo *TemplateArgs)
1117     : Expr(CXXDependentScopeMemberExprClass, C.DependentTy, VK_LValue,
1118            OK_Ordinary, true, true, true,
1119            ((Base && Base->containsUnexpandedParameterPack()) ||
1120             (QualifierLoc &&
1121              QualifierLoc.getNestedNameSpecifier()
1122                  ->containsUnexpandedParameterPack()) ||
1123             MemberNameInfo.containsUnexpandedParameterPack())),
1124       Base(Base), BaseType(BaseType), IsArrow(IsArrow),
1125       HasTemplateKWAndArgsInfo(TemplateArgs != nullptr ||
1126                                TemplateKWLoc.isValid()),
1127       OperatorLoc(OperatorLoc), QualifierLoc(QualifierLoc),
1128       FirstQualifierFoundInScope(FirstQualifierFoundInScope),
1129       MemberNameInfo(MemberNameInfo) {
1130   if (TemplateArgs) {
1131     bool Dependent = true;
1132     bool InstantiationDependent = true;
1133     bool ContainsUnexpandedParameterPack = false;
1134     getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
1135         TemplateKWLoc, *TemplateArgs, getTrailingObjects<TemplateArgumentLoc>(),
1136         Dependent, InstantiationDependent, ContainsUnexpandedParameterPack);
1137     if (ContainsUnexpandedParameterPack)
1138       ExprBits.ContainsUnexpandedParameterPack = true;
1139   } else if (TemplateKWLoc.isValid()) {
1140     getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
1141         TemplateKWLoc);
1142   }
1143 }
1144 
1145 CXXDependentScopeMemberExpr *
1146 CXXDependentScopeMemberExpr::Create(const ASTContext &C,
1147                                 Expr *Base, QualType BaseType, bool IsArrow,
1148                                 SourceLocation OperatorLoc,
1149                                 NestedNameSpecifierLoc QualifierLoc,
1150                                 SourceLocation TemplateKWLoc,
1151                                 NamedDecl *FirstQualifierFoundInScope,
1152                                 DeclarationNameInfo MemberNameInfo,
1153                                 const TemplateArgumentListInfo *TemplateArgs) {
1154   bool HasTemplateKWAndArgsInfo = TemplateArgs || TemplateKWLoc.isValid();
1155   unsigned NumTemplateArgs = TemplateArgs ? TemplateArgs->size() : 0;
1156   std::size_t Size =
1157       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
1158           HasTemplateKWAndArgsInfo, NumTemplateArgs);
1159 
1160   void *Mem = C.Allocate(Size, alignof(CXXDependentScopeMemberExpr));
1161   return new (Mem) CXXDependentScopeMemberExpr(C, Base, BaseType,
1162                                                IsArrow, OperatorLoc,
1163                                                QualifierLoc,
1164                                                TemplateKWLoc,
1165                                                FirstQualifierFoundInScope,
1166                                                MemberNameInfo, TemplateArgs);
1167 }
1168 
1169 CXXDependentScopeMemberExpr *
1170 CXXDependentScopeMemberExpr::CreateEmpty(const ASTContext &C,
1171                                          bool HasTemplateKWAndArgsInfo,
1172                                          unsigned NumTemplateArgs) {
1173   assert(NumTemplateArgs == 0 || HasTemplateKWAndArgsInfo);
1174   std::size_t Size =
1175       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
1176           HasTemplateKWAndArgsInfo, NumTemplateArgs);
1177   void *Mem = C.Allocate(Size, alignof(CXXDependentScopeMemberExpr));
1178   auto *E =
1179       new (Mem) CXXDependentScopeMemberExpr(C, nullptr, QualType(),
1180                                             false, SourceLocation(),
1181                                             NestedNameSpecifierLoc(),
1182                                             SourceLocation(), nullptr,
1183                                             DeclarationNameInfo(), nullptr);
1184   E->HasTemplateKWAndArgsInfo = HasTemplateKWAndArgsInfo;
1185   return E;
1186 }
1187 
1188 bool CXXDependentScopeMemberExpr::isImplicitAccess() const {
1189   if (!Base)
1190     return true;
1191 
1192   return cast<Expr>(Base)->isImplicitCXXThis();
1193 }
1194 
1195 static bool hasOnlyNonStaticMemberFunctions(UnresolvedSetIterator begin,
1196                                             UnresolvedSetIterator end) {
1197   do {
1198     NamedDecl *decl = *begin;
1199     if (isa<UnresolvedUsingValueDecl>(decl))
1200       return false;
1201 
1202     // Unresolved member expressions should only contain methods and
1203     // method templates.
1204     if (cast<CXXMethodDecl>(decl->getUnderlyingDecl()->getAsFunction())
1205             ->isStatic())
1206       return false;
1207   } while (++begin != end);
1208 
1209   return true;
1210 }
1211 
1212 UnresolvedMemberExpr::UnresolvedMemberExpr(const ASTContext &C,
1213                                            bool HasUnresolvedUsing,
1214                                            Expr *Base, QualType BaseType,
1215                                            bool IsArrow,
1216                                            SourceLocation OperatorLoc,
1217                                            NestedNameSpecifierLoc QualifierLoc,
1218                                            SourceLocation TemplateKWLoc,
1219                                    const DeclarationNameInfo &MemberNameInfo,
1220                                    const TemplateArgumentListInfo *TemplateArgs,
1221                                            UnresolvedSetIterator Begin,
1222                                            UnresolvedSetIterator End)
1223     : OverloadExpr(
1224           UnresolvedMemberExprClass, C, QualifierLoc, TemplateKWLoc,
1225           MemberNameInfo, TemplateArgs, Begin, End,
1226           // Dependent
1227           ((Base && Base->isTypeDependent()) || BaseType->isDependentType()),
1228           ((Base && Base->isInstantiationDependent()) ||
1229            BaseType->isInstantiationDependentType()),
1230           // Contains unexpanded parameter pack
1231           ((Base && Base->containsUnexpandedParameterPack()) ||
1232            BaseType->containsUnexpandedParameterPack())),
1233       IsArrow(IsArrow), HasUnresolvedUsing(HasUnresolvedUsing), Base(Base),
1234       BaseType(BaseType), OperatorLoc(OperatorLoc) {
1235   // Check whether all of the members are non-static member functions,
1236   // and if so, mark give this bound-member type instead of overload type.
1237   if (hasOnlyNonStaticMemberFunctions(Begin, End))
1238     setType(C.BoundMemberTy);
1239 }
1240 
1241 bool UnresolvedMemberExpr::isImplicitAccess() const {
1242   if (!Base)
1243     return true;
1244 
1245   return cast<Expr>(Base)->isImplicitCXXThis();
1246 }
1247 
1248 UnresolvedMemberExpr *UnresolvedMemberExpr::Create(
1249     const ASTContext &C, bool HasUnresolvedUsing, Expr *Base, QualType BaseType,
1250     bool IsArrow, SourceLocation OperatorLoc,
1251     NestedNameSpecifierLoc QualifierLoc, SourceLocation TemplateKWLoc,
1252     const DeclarationNameInfo &MemberNameInfo,
1253     const TemplateArgumentListInfo *TemplateArgs, UnresolvedSetIterator Begin,
1254     UnresolvedSetIterator End) {
1255   bool HasTemplateKWAndArgsInfo = TemplateArgs || TemplateKWLoc.isValid();
1256   std::size_t Size =
1257       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
1258           HasTemplateKWAndArgsInfo, TemplateArgs ? TemplateArgs->size() : 0);
1259 
1260   void *Mem = C.Allocate(Size, alignof(UnresolvedMemberExpr));
1261   return new (Mem) UnresolvedMemberExpr(
1262       C, HasUnresolvedUsing, Base, BaseType, IsArrow, OperatorLoc, QualifierLoc,
1263       TemplateKWLoc, MemberNameInfo, TemplateArgs, Begin, End);
1264 }
1265 
1266 UnresolvedMemberExpr *
1267 UnresolvedMemberExpr::CreateEmpty(const ASTContext &C,
1268                                   bool HasTemplateKWAndArgsInfo,
1269                                   unsigned NumTemplateArgs) {
1270   assert(NumTemplateArgs == 0 || HasTemplateKWAndArgsInfo);
1271   std::size_t Size =
1272       totalSizeToAlloc<ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
1273           HasTemplateKWAndArgsInfo, NumTemplateArgs);
1274 
1275   void *Mem = C.Allocate(Size, alignof(UnresolvedMemberExpr));
1276   auto *E = new (Mem) UnresolvedMemberExpr(EmptyShell());
1277   E->HasTemplateKWAndArgsInfo = HasTemplateKWAndArgsInfo;
1278   return E;
1279 }
1280 
1281 CXXRecordDecl *UnresolvedMemberExpr::getNamingClass() const {
1282   // Unlike for UnresolvedLookupExpr, it is very easy to re-derive this.
1283 
1284   // If there was a nested name specifier, it names the naming class.
1285   // It can't be dependent: after all, we were actually able to do the
1286   // lookup.
1287   CXXRecordDecl *Record = nullptr;
1288   auto *NNS = getQualifier();
1289   if (NNS && NNS->getKind() != NestedNameSpecifier::Super) {
1290     const Type *T = getQualifier()->getAsType();
1291     assert(T && "qualifier in member expression does not name type");
1292     Record = T->getAsCXXRecordDecl();
1293     assert(Record && "qualifier in member expression does not name record");
1294   }
1295   // Otherwise the naming class must have been the base class.
1296   else {
1297     QualType BaseType = getBaseType().getNonReferenceType();
1298     if (isArrow()) {
1299       const auto *PT = BaseType->getAs<PointerType>();
1300       assert(PT && "base of arrow member access is not pointer");
1301       BaseType = PT->getPointeeType();
1302     }
1303 
1304     Record = BaseType->getAsCXXRecordDecl();
1305     assert(Record && "base of member expression does not name record");
1306   }
1307 
1308   return Record;
1309 }
1310 
1311 SizeOfPackExpr *
1312 SizeOfPackExpr::Create(ASTContext &Context, SourceLocation OperatorLoc,
1313                        NamedDecl *Pack, SourceLocation PackLoc,
1314                        SourceLocation RParenLoc,
1315                        Optional<unsigned> Length,
1316                        ArrayRef<TemplateArgument> PartialArgs) {
1317   void *Storage =
1318       Context.Allocate(totalSizeToAlloc<TemplateArgument>(PartialArgs.size()));
1319   return new (Storage) SizeOfPackExpr(Context.getSizeType(), OperatorLoc, Pack,
1320                                       PackLoc, RParenLoc, Length, PartialArgs);
1321 }
1322 
1323 SizeOfPackExpr *SizeOfPackExpr::CreateDeserialized(ASTContext &Context,
1324                                                    unsigned NumPartialArgs) {
1325   void *Storage =
1326       Context.Allocate(totalSizeToAlloc<TemplateArgument>(NumPartialArgs));
1327   return new (Storage) SizeOfPackExpr(EmptyShell(), NumPartialArgs);
1328 }
1329 
1330 SubstNonTypeTemplateParmPackExpr::
1331 SubstNonTypeTemplateParmPackExpr(QualType T,
1332                                  ExprValueKind ValueKind,
1333                                  NonTypeTemplateParmDecl *Param,
1334                                  SourceLocation NameLoc,
1335                                  const TemplateArgument &ArgPack)
1336     : Expr(SubstNonTypeTemplateParmPackExprClass, T, ValueKind, OK_Ordinary,
1337            true, true, true, true),
1338       Param(Param), Arguments(ArgPack.pack_begin()),
1339       NumArguments(ArgPack.pack_size()), NameLoc(NameLoc) {}
1340 
1341 TemplateArgument SubstNonTypeTemplateParmPackExpr::getArgumentPack() const {
1342   return TemplateArgument(llvm::makeArrayRef(Arguments, NumArguments));
1343 }
1344 
1345 FunctionParmPackExpr::FunctionParmPackExpr(QualType T, ParmVarDecl *ParamPack,
1346                                            SourceLocation NameLoc,
1347                                            unsigned NumParams,
1348                                            ParmVarDecl *const *Params)
1349     : Expr(FunctionParmPackExprClass, T, VK_LValue, OK_Ordinary, true, true,
1350            true, true),
1351       ParamPack(ParamPack), NameLoc(NameLoc), NumParameters(NumParams) {
1352   if (Params)
1353     std::uninitialized_copy(Params, Params + NumParams,
1354                             getTrailingObjects<ParmVarDecl *>());
1355 }
1356 
1357 FunctionParmPackExpr *
1358 FunctionParmPackExpr::Create(const ASTContext &Context, QualType T,
1359                              ParmVarDecl *ParamPack, SourceLocation NameLoc,
1360                              ArrayRef<ParmVarDecl *> Params) {
1361   return new (Context.Allocate(totalSizeToAlloc<ParmVarDecl *>(Params.size())))
1362       FunctionParmPackExpr(T, ParamPack, NameLoc, Params.size(), Params.data());
1363 }
1364 
1365 FunctionParmPackExpr *
1366 FunctionParmPackExpr::CreateEmpty(const ASTContext &Context,
1367                                   unsigned NumParams) {
1368   return new (Context.Allocate(totalSizeToAlloc<ParmVarDecl *>(NumParams)))
1369       FunctionParmPackExpr(QualType(), nullptr, SourceLocation(), 0, nullptr);
1370 }
1371 
1372 void MaterializeTemporaryExpr::setExtendingDecl(const ValueDecl *ExtendedBy,
1373                                                 unsigned ManglingNumber) {
1374   // We only need extra state if we have to remember more than just the Stmt.
1375   if (!ExtendedBy)
1376     return;
1377 
1378   // We may need to allocate extra storage for the mangling number and the
1379   // extended-by ValueDecl.
1380   if (!State.is<ExtraState *>()) {
1381     auto *ES = new (ExtendedBy->getASTContext()) ExtraState;
1382     ES->Temporary = State.get<Stmt *>();
1383     State = ES;
1384   }
1385 
1386   auto ES = State.get<ExtraState *>();
1387   ES->ExtendingDecl = ExtendedBy;
1388   ES->ManglingNumber = ManglingNumber;
1389 }
1390 
1391 TypeTraitExpr::TypeTraitExpr(QualType T, SourceLocation Loc, TypeTrait Kind,
1392                              ArrayRef<TypeSourceInfo *> Args,
1393                              SourceLocation RParenLoc,
1394                              bool Value)
1395     : Expr(TypeTraitExprClass, T, VK_RValue, OK_Ordinary,
1396            /*TypeDependent=*/false,
1397            /*ValueDependent=*/false,
1398            /*InstantiationDependent=*/false,
1399            /*ContainsUnexpandedParameterPack=*/false),
1400       Loc(Loc), RParenLoc(RParenLoc) {
1401   TypeTraitExprBits.Kind = Kind;
1402   TypeTraitExprBits.Value = Value;
1403   TypeTraitExprBits.NumArgs = Args.size();
1404 
1405   auto **ToArgs = getTrailingObjects<TypeSourceInfo *>();
1406 
1407   for (unsigned I = 0, N = Args.size(); I != N; ++I) {
1408     if (Args[I]->getType()->isDependentType())
1409       setValueDependent(true);
1410     if (Args[I]->getType()->isInstantiationDependentType())
1411       setInstantiationDependent(true);
1412     if (Args[I]->getType()->containsUnexpandedParameterPack())
1413       setContainsUnexpandedParameterPack(true);
1414 
1415     ToArgs[I] = Args[I];
1416   }
1417 }
1418 
1419 TypeTraitExpr *TypeTraitExpr::Create(const ASTContext &C, QualType T,
1420                                      SourceLocation Loc,
1421                                      TypeTrait Kind,
1422                                      ArrayRef<TypeSourceInfo *> Args,
1423                                      SourceLocation RParenLoc,
1424                                      bool Value) {
1425   void *Mem = C.Allocate(totalSizeToAlloc<TypeSourceInfo *>(Args.size()));
1426   return new (Mem) TypeTraitExpr(T, Loc, Kind, Args, RParenLoc, Value);
1427 }
1428 
1429 TypeTraitExpr *TypeTraitExpr::CreateDeserialized(const ASTContext &C,
1430                                                  unsigned NumArgs) {
1431   void *Mem = C.Allocate(totalSizeToAlloc<TypeSourceInfo *>(NumArgs));
1432   return new (Mem) TypeTraitExpr(EmptyShell());
1433 }
1434 
1435 void ArrayTypeTraitExpr::anchor() {}
1436