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      1 //===--- Expr.cpp - 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 Expr class and subclasses.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/AST/APValue.h"
     15 #include "clang/AST/ASTContext.h"
     16 #include "clang/AST/Attr.h"
     17 #include "clang/AST/DeclCXX.h"
     18 #include "clang/AST/DeclObjC.h"
     19 #include "clang/AST/DeclTemplate.h"
     20 #include "clang/AST/EvaluatedExprVisitor.h"
     21 #include "clang/AST/Expr.h"
     22 #include "clang/AST/ExprCXX.h"
     23 #include "clang/AST/Mangle.h"
     24 #include "clang/AST/RecordLayout.h"
     25 #include "clang/AST/StmtVisitor.h"
     26 #include "clang/Basic/Builtins.h"
     27 #include "clang/Basic/CharInfo.h"
     28 #include "clang/Basic/SourceManager.h"
     29 #include "clang/Basic/TargetInfo.h"
     30 #include "clang/Lex/Lexer.h"
     31 #include "clang/Lex/LiteralSupport.h"
     32 #include "clang/Sema/SemaDiagnostic.h"
     33 #include "llvm/Support/ErrorHandling.h"
     34 #include "llvm/Support/raw_ostream.h"
     35 #include <algorithm>
     36 #include <cstring>
     37 using namespace clang;
     38 
     39 const CXXRecordDecl *Expr::getBestDynamicClassType() const {
     40   const Expr *E = ignoreParenBaseCasts();
     41 
     42   QualType DerivedType = E->getType();
     43   if (const PointerType *PTy = DerivedType->getAs<PointerType>())
     44     DerivedType = PTy->getPointeeType();
     45 
     46   if (DerivedType->isDependentType())
     47     return nullptr;
     48 
     49   const RecordType *Ty = DerivedType->castAs<RecordType>();
     50   Decl *D = Ty->getDecl();
     51   return cast<CXXRecordDecl>(D);
     52 }
     53 
     54 const Expr *Expr::skipRValueSubobjectAdjustments(
     55     SmallVectorImpl<const Expr *> &CommaLHSs,
     56     SmallVectorImpl<SubobjectAdjustment> &Adjustments) const {
     57   const Expr *E = this;
     58   while (true) {
     59     E = E->IgnoreParens();
     60 
     61     if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
     62       if ((CE->getCastKind() == CK_DerivedToBase ||
     63            CE->getCastKind() == CK_UncheckedDerivedToBase) &&
     64           E->getType()->isRecordType()) {
     65         E = CE->getSubExpr();
     66         CXXRecordDecl *Derived
     67           = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
     68         Adjustments.push_back(SubobjectAdjustment(CE, Derived));
     69         continue;
     70       }
     71 
     72       if (CE->getCastKind() == CK_NoOp) {
     73         E = CE->getSubExpr();
     74         continue;
     75       }
     76     } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
     77       if (!ME->isArrow()) {
     78         assert(ME->getBase()->getType()->isRecordType());
     79         if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
     80           if (!Field->isBitField() && !Field->getType()->isReferenceType()) {
     81             E = ME->getBase();
     82             Adjustments.push_back(SubobjectAdjustment(Field));
     83             continue;
     84           }
     85         }
     86       }
     87     } else if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
     88       if (BO->isPtrMemOp()) {
     89         assert(BO->getRHS()->isRValue());
     90         E = BO->getLHS();
     91         const MemberPointerType *MPT =
     92           BO->getRHS()->getType()->getAs<MemberPointerType>();
     93         Adjustments.push_back(SubobjectAdjustment(MPT, BO->getRHS()));
     94         continue;
     95       } else if (BO->getOpcode() == BO_Comma) {
     96         CommaLHSs.push_back(BO->getLHS());
     97         E = BO->getRHS();
     98         continue;
     99       }
    100     }
    101 
    102     // Nothing changed.
    103     break;
    104   }
    105   return E;
    106 }
    107 
    108 /// isKnownToHaveBooleanValue - Return true if this is an integer expression
    109 /// that is known to return 0 or 1.  This happens for _Bool/bool expressions
    110 /// but also int expressions which are produced by things like comparisons in
    111 /// C.
    112 bool Expr::isKnownToHaveBooleanValue() const {
    113   const Expr *E = IgnoreParens();
    114 
    115   // If this value has _Bool type, it is obvious 0/1.
    116   if (E->getType()->isBooleanType()) return true;
    117   // If this is a non-scalar-integer type, we don't care enough to try.
    118   if (!E->getType()->isIntegralOrEnumerationType()) return false;
    119 
    120   if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
    121     switch (UO->getOpcode()) {
    122     case UO_Plus:
    123       return UO->getSubExpr()->isKnownToHaveBooleanValue();
    124     case UO_LNot:
    125       return true;
    126     default:
    127       return false;
    128     }
    129   }
    130 
    131   // Only look through implicit casts.  If the user writes
    132   // '(int) (a && b)' treat it as an arbitrary int.
    133   if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E))
    134     return CE->getSubExpr()->isKnownToHaveBooleanValue();
    135 
    136   if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
    137     switch (BO->getOpcode()) {
    138     default: return false;
    139     case BO_LT:   // Relational operators.
    140     case BO_GT:
    141     case BO_LE:
    142     case BO_GE:
    143     case BO_EQ:   // Equality operators.
    144     case BO_NE:
    145     case BO_LAnd: // AND operator.
    146     case BO_LOr:  // Logical OR operator.
    147       return true;
    148 
    149     case BO_And:  // Bitwise AND operator.
    150     case BO_Xor:  // Bitwise XOR operator.
    151     case BO_Or:   // Bitwise OR operator.
    152       // Handle things like (x==2)|(y==12).
    153       return BO->getLHS()->isKnownToHaveBooleanValue() &&
    154              BO->getRHS()->isKnownToHaveBooleanValue();
    155 
    156     case BO_Comma:
    157     case BO_Assign:
    158       return BO->getRHS()->isKnownToHaveBooleanValue();
    159     }
    160   }
    161 
    162   if (const ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E))
    163     return CO->getTrueExpr()->isKnownToHaveBooleanValue() &&
    164            CO->getFalseExpr()->isKnownToHaveBooleanValue();
    165 
    166   return false;
    167 }
    168 
    169 // Amusing macro metaprogramming hack: check whether a class provides
    170 // a more specific implementation of getExprLoc().
    171 //
    172 // See also Stmt.cpp:{getLocStart(),getLocEnd()}.
    173 namespace {
    174   /// This implementation is used when a class provides a custom
    175   /// implementation of getExprLoc.
    176   template <class E, class T>
    177   SourceLocation getExprLocImpl(const Expr *expr,
    178                                 SourceLocation (T::*v)() const) {
    179     return static_cast<const E*>(expr)->getExprLoc();
    180   }
    181 
    182   /// This implementation is used when a class doesn't provide
    183   /// a custom implementation of getExprLoc.  Overload resolution
    184   /// should pick it over the implementation above because it's
    185   /// more specialized according to function template partial ordering.
    186   template <class E>
    187   SourceLocation getExprLocImpl(const Expr *expr,
    188                                 SourceLocation (Expr::*v)() const) {
    189     return static_cast<const E*>(expr)->getLocStart();
    190   }
    191 }
    192 
    193 SourceLocation Expr::getExprLoc() const {
    194   switch (getStmtClass()) {
    195   case Stmt::NoStmtClass: llvm_unreachable("statement without class");
    196 #define ABSTRACT_STMT(type)
    197 #define STMT(type, base) \
    198   case Stmt::type##Class: llvm_unreachable(#type " is not an Expr"); break;
    199 #define EXPR(type, base) \
    200   case Stmt::type##Class: return getExprLocImpl<type>(this, &type::getExprLoc);
    201 #include "clang/AST/StmtNodes.inc"
    202   }
    203   llvm_unreachable("unknown statement kind");
    204 }
    205 
    206 //===----------------------------------------------------------------------===//
    207 // Primary Expressions.
    208 //===----------------------------------------------------------------------===//
    209 
    210 /// \brief Compute the type-, value-, and instantiation-dependence of a
    211 /// declaration reference
    212 /// based on the declaration being referenced.
    213 static void computeDeclRefDependence(const ASTContext &Ctx, NamedDecl *D,
    214                                      QualType T, bool &TypeDependent,
    215                                      bool &ValueDependent,
    216                                      bool &InstantiationDependent) {
    217   TypeDependent = false;
    218   ValueDependent = false;
    219   InstantiationDependent = false;
    220 
    221   // (TD) C++ [temp.dep.expr]p3:
    222   //   An id-expression is type-dependent if it contains:
    223   //
    224   // and
    225   //
    226   // (VD) C++ [temp.dep.constexpr]p2:
    227   //  An identifier is value-dependent if it is:
    228 
    229   //  (TD)  - an identifier that was declared with dependent type
    230   //  (VD)  - a name declared with a dependent type,
    231   if (T->isDependentType()) {
    232     TypeDependent = true;
    233     ValueDependent = true;
    234     InstantiationDependent = true;
    235     return;
    236   } else if (T->isInstantiationDependentType()) {
    237     InstantiationDependent = true;
    238   }
    239 
    240   //  (TD)  - a conversion-function-id that specifies a dependent type
    241   if (D->getDeclName().getNameKind()
    242                                 == DeclarationName::CXXConversionFunctionName) {
    243     QualType T = D->getDeclName().getCXXNameType();
    244     if (T->isDependentType()) {
    245       TypeDependent = true;
    246       ValueDependent = true;
    247       InstantiationDependent = true;
    248       return;
    249     }
    250 
    251     if (T->isInstantiationDependentType())
    252       InstantiationDependent = true;
    253   }
    254 
    255   //  (VD)  - the name of a non-type template parameter,
    256   if (isa<NonTypeTemplateParmDecl>(D)) {
    257     ValueDependent = true;
    258     InstantiationDependent = true;
    259     return;
    260   }
    261 
    262   //  (VD) - a constant with integral or enumeration type and is
    263   //         initialized with an expression that is value-dependent.
    264   //  (VD) - a constant with literal type and is initialized with an
    265   //         expression that is value-dependent [C++11].
    266   //  (VD) - FIXME: Missing from the standard:
    267   //       -  an entity with reference type and is initialized with an
    268   //          expression that is value-dependent [C++11]
    269   if (VarDecl *Var = dyn_cast<VarDecl>(D)) {
    270     if ((Ctx.getLangOpts().CPlusPlus11 ?
    271            Var->getType()->isLiteralType(Ctx) :
    272            Var->getType()->isIntegralOrEnumerationType()) &&
    273         (Var->getType().isConstQualified() ||
    274          Var->getType()->isReferenceType())) {
    275       if (const Expr *Init = Var->getAnyInitializer())
    276         if (Init->isValueDependent()) {
    277           ValueDependent = true;
    278           InstantiationDependent = true;
    279         }
    280     }
    281 
    282     // (VD) - FIXME: Missing from the standard:
    283     //      -  a member function or a static data member of the current
    284     //         instantiation
    285     if (Var->isStaticDataMember() &&
    286         Var->getDeclContext()->isDependentContext()) {
    287       ValueDependent = true;
    288       InstantiationDependent = true;
    289       TypeSourceInfo *TInfo = Var->getFirstDecl()->getTypeSourceInfo();
    290       if (TInfo->getType()->isIncompleteArrayType())
    291         TypeDependent = true;
    292     }
    293 
    294     return;
    295   }
    296 
    297   // (VD) - FIXME: Missing from the standard:
    298   //      -  a member function or a static data member of the current
    299   //         instantiation
    300   if (isa<CXXMethodDecl>(D) && D->getDeclContext()->isDependentContext()) {
    301     ValueDependent = true;
    302     InstantiationDependent = true;
    303   }
    304 }
    305 
    306 void DeclRefExpr::computeDependence(const ASTContext &Ctx) {
    307   bool TypeDependent = false;
    308   bool ValueDependent = false;
    309   bool InstantiationDependent = false;
    310   computeDeclRefDependence(Ctx, getDecl(), getType(), TypeDependent,
    311                            ValueDependent, InstantiationDependent);
    312 
    313   // (TD) C++ [temp.dep.expr]p3:
    314   //   An id-expression is type-dependent if it contains:
    315   //
    316   // and
    317   //
    318   // (VD) C++ [temp.dep.constexpr]p2:
    319   //  An identifier is value-dependent if it is:
    320   if (!TypeDependent && !ValueDependent &&
    321       hasExplicitTemplateArgs() &&
    322       TemplateSpecializationType::anyDependentTemplateArguments(
    323                                                             getTemplateArgs(),
    324                                                        getNumTemplateArgs(),
    325                                                       InstantiationDependent)) {
    326     TypeDependent = true;
    327     ValueDependent = true;
    328     InstantiationDependent = true;
    329   }
    330 
    331   ExprBits.TypeDependent = TypeDependent;
    332   ExprBits.ValueDependent = ValueDependent;
    333   ExprBits.InstantiationDependent = InstantiationDependent;
    334 
    335   // Is the declaration a parameter pack?
    336   if (getDecl()->isParameterPack())
    337     ExprBits.ContainsUnexpandedParameterPack = true;
    338 }
    339 
    340 DeclRefExpr::DeclRefExpr(const ASTContext &Ctx,
    341                          NestedNameSpecifierLoc QualifierLoc,
    342                          SourceLocation TemplateKWLoc,
    343                          ValueDecl *D, bool RefersToEnclosingLocal,
    344                          const DeclarationNameInfo &NameInfo,
    345                          NamedDecl *FoundD,
    346                          const TemplateArgumentListInfo *TemplateArgs,
    347                          QualType T, ExprValueKind VK)
    348   : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false, false),
    349     D(D), Loc(NameInfo.getLoc()), DNLoc(NameInfo.getInfo()) {
    350   DeclRefExprBits.HasQualifier = QualifierLoc ? 1 : 0;
    351   if (QualifierLoc)
    352     getInternalQualifierLoc() = QualifierLoc;
    353   DeclRefExprBits.HasFoundDecl = FoundD ? 1 : 0;
    354   if (FoundD)
    355     getInternalFoundDecl() = FoundD;
    356   DeclRefExprBits.HasTemplateKWAndArgsInfo
    357     = (TemplateArgs || TemplateKWLoc.isValid()) ? 1 : 0;
    358   DeclRefExprBits.RefersToEnclosingLocal = RefersToEnclosingLocal;
    359   if (TemplateArgs) {
    360     bool Dependent = false;
    361     bool InstantiationDependent = false;
    362     bool ContainsUnexpandedParameterPack = false;
    363     getTemplateKWAndArgsInfo()->initializeFrom(TemplateKWLoc, *TemplateArgs,
    364                                                Dependent,
    365                                                InstantiationDependent,
    366                                                ContainsUnexpandedParameterPack);
    367     if (InstantiationDependent)
    368       setInstantiationDependent(true);
    369   } else if (TemplateKWLoc.isValid()) {
    370     getTemplateKWAndArgsInfo()->initializeFrom(TemplateKWLoc);
    371   }
    372   DeclRefExprBits.HadMultipleCandidates = 0;
    373 
    374   computeDependence(Ctx);
    375 }
    376 
    377 DeclRefExpr *DeclRefExpr::Create(const ASTContext &Context,
    378                                  NestedNameSpecifierLoc QualifierLoc,
    379                                  SourceLocation TemplateKWLoc,
    380                                  ValueDecl *D,
    381                                  bool RefersToEnclosingLocal,
    382                                  SourceLocation NameLoc,
    383                                  QualType T,
    384                                  ExprValueKind VK,
    385                                  NamedDecl *FoundD,
    386                                  const TemplateArgumentListInfo *TemplateArgs) {
    387   return Create(Context, QualifierLoc, TemplateKWLoc, D,
    388                 RefersToEnclosingLocal,
    389                 DeclarationNameInfo(D->getDeclName(), NameLoc),
    390                 T, VK, FoundD, TemplateArgs);
    391 }
    392 
    393 DeclRefExpr *DeclRefExpr::Create(const ASTContext &Context,
    394                                  NestedNameSpecifierLoc QualifierLoc,
    395                                  SourceLocation TemplateKWLoc,
    396                                  ValueDecl *D,
    397                                  bool RefersToEnclosingLocal,
    398                                  const DeclarationNameInfo &NameInfo,
    399                                  QualType T,
    400                                  ExprValueKind VK,
    401                                  NamedDecl *FoundD,
    402                                  const TemplateArgumentListInfo *TemplateArgs) {
    403   // Filter out cases where the found Decl is the same as the value refenenced.
    404   if (D == FoundD)
    405     FoundD = nullptr;
    406 
    407   std::size_t Size = sizeof(DeclRefExpr);
    408   if (QualifierLoc)
    409     Size += sizeof(NestedNameSpecifierLoc);
    410   if (FoundD)
    411     Size += sizeof(NamedDecl *);
    412   if (TemplateArgs)
    413     Size += ASTTemplateKWAndArgsInfo::sizeFor(TemplateArgs->size());
    414   else if (TemplateKWLoc.isValid())
    415     Size += ASTTemplateKWAndArgsInfo::sizeFor(0);
    416 
    417   void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
    418   return new (Mem) DeclRefExpr(Context, QualifierLoc, TemplateKWLoc, D,
    419                                RefersToEnclosingLocal,
    420                                NameInfo, FoundD, TemplateArgs, T, VK);
    421 }
    422 
    423 DeclRefExpr *DeclRefExpr::CreateEmpty(const ASTContext &Context,
    424                                       bool HasQualifier,
    425                                       bool HasFoundDecl,
    426                                       bool HasTemplateKWAndArgsInfo,
    427                                       unsigned NumTemplateArgs) {
    428   std::size_t Size = sizeof(DeclRefExpr);
    429   if (HasQualifier)
    430     Size += sizeof(NestedNameSpecifierLoc);
    431   if (HasFoundDecl)
    432     Size += sizeof(NamedDecl *);
    433   if (HasTemplateKWAndArgsInfo)
    434     Size += ASTTemplateKWAndArgsInfo::sizeFor(NumTemplateArgs);
    435 
    436   void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
    437   return new (Mem) DeclRefExpr(EmptyShell());
    438 }
    439 
    440 SourceLocation DeclRefExpr::getLocStart() const {
    441   if (hasQualifier())
    442     return getQualifierLoc().getBeginLoc();
    443   return getNameInfo().getLocStart();
    444 }
    445 SourceLocation DeclRefExpr::getLocEnd() const {
    446   if (hasExplicitTemplateArgs())
    447     return getRAngleLoc();
    448   return getNameInfo().getLocEnd();
    449 }
    450 
    451 // FIXME: Maybe this should use DeclPrinter with a special "print predefined
    452 // expr" policy instead.
    453 std::string PredefinedExpr::ComputeName(IdentType IT, const Decl *CurrentDecl) {
    454   ASTContext &Context = CurrentDecl->getASTContext();
    455 
    456   if (IT == PredefinedExpr::FuncDName) {
    457     if (const NamedDecl *ND = dyn_cast<NamedDecl>(CurrentDecl)) {
    458       std::unique_ptr<MangleContext> MC;
    459       MC.reset(Context.createMangleContext());
    460 
    461       if (MC->shouldMangleDeclName(ND)) {
    462         SmallString<256> Buffer;
    463         llvm::raw_svector_ostream Out(Buffer);
    464         if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(ND))
    465           MC->mangleCXXCtor(CD, Ctor_Base, Out);
    466         else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(ND))
    467           MC->mangleCXXDtor(DD, Dtor_Base, Out);
    468         else
    469           MC->mangleName(ND, Out);
    470 
    471         Out.flush();
    472         if (!Buffer.empty() && Buffer.front() == '\01')
    473           return Buffer.substr(1);
    474         return Buffer.str();
    475       } else
    476         return ND->getIdentifier()->getName();
    477     }
    478     return "";
    479   }
    480   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
    481     if (IT != PrettyFunction && IT != PrettyFunctionNoVirtual && IT != FuncSig)
    482       return FD->getNameAsString();
    483 
    484     SmallString<256> Name;
    485     llvm::raw_svector_ostream Out(Name);
    486 
    487     if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
    488       if (MD->isVirtual() && IT != PrettyFunctionNoVirtual)
    489         Out << "virtual ";
    490       if (MD->isStatic())
    491         Out << "static ";
    492     }
    493 
    494     PrintingPolicy Policy(Context.getLangOpts());
    495     std::string Proto;
    496     llvm::raw_string_ostream POut(Proto);
    497 
    498     const FunctionDecl *Decl = FD;
    499     if (const FunctionDecl* Pattern = FD->getTemplateInstantiationPattern())
    500       Decl = Pattern;
    501     const FunctionType *AFT = Decl->getType()->getAs<FunctionType>();
    502     const FunctionProtoType *FT = nullptr;
    503     if (FD->hasWrittenPrototype())
    504       FT = dyn_cast<FunctionProtoType>(AFT);
    505 
    506     if (IT == FuncSig) {
    507       switch (FT->getCallConv()) {
    508       case CC_C: POut << "__cdecl "; break;
    509       case CC_X86StdCall: POut << "__stdcall "; break;
    510       case CC_X86FastCall: POut << "__fastcall "; break;
    511       case CC_X86ThisCall: POut << "__thiscall "; break;
    512       // Only bother printing the conventions that MSVC knows about.
    513       default: break;
    514       }
    515     }
    516 
    517     FD->printQualifiedName(POut, Policy);
    518 
    519     POut << "(";
    520     if (FT) {
    521       for (unsigned i = 0, e = Decl->getNumParams(); i != e; ++i) {
    522         if (i) POut << ", ";
    523         POut << Decl->getParamDecl(i)->getType().stream(Policy);
    524       }
    525 
    526       if (FT->isVariadic()) {
    527         if (FD->getNumParams()) POut << ", ";
    528         POut << "...";
    529       }
    530     }
    531     POut << ")";
    532 
    533     if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
    534       const FunctionType *FT = MD->getType()->castAs<FunctionType>();
    535       if (FT->isConst())
    536         POut << " const";
    537       if (FT->isVolatile())
    538         POut << " volatile";
    539       RefQualifierKind Ref = MD->getRefQualifier();
    540       if (Ref == RQ_LValue)
    541         POut << " &";
    542       else if (Ref == RQ_RValue)
    543         POut << " &&";
    544     }
    545 
    546     typedef SmallVector<const ClassTemplateSpecializationDecl *, 8> SpecsTy;
    547     SpecsTy Specs;
    548     const DeclContext *Ctx = FD->getDeclContext();
    549     while (Ctx && isa<NamedDecl>(Ctx)) {
    550       const ClassTemplateSpecializationDecl *Spec
    551                                = dyn_cast<ClassTemplateSpecializationDecl>(Ctx);
    552       if (Spec && !Spec->isExplicitSpecialization())
    553         Specs.push_back(Spec);
    554       Ctx = Ctx->getParent();
    555     }
    556 
    557     std::string TemplateParams;
    558     llvm::raw_string_ostream TOut(TemplateParams);
    559     for (SpecsTy::reverse_iterator I = Specs.rbegin(), E = Specs.rend();
    560          I != E; ++I) {
    561       const TemplateParameterList *Params
    562                   = (*I)->getSpecializedTemplate()->getTemplateParameters();
    563       const TemplateArgumentList &Args = (*I)->getTemplateArgs();
    564       assert(Params->size() == Args.size());
    565       for (unsigned i = 0, numParams = Params->size(); i != numParams; ++i) {
    566         StringRef Param = Params->getParam(i)->getName();
    567         if (Param.empty()) continue;
    568         TOut << Param << " = ";
    569         Args.get(i).print(Policy, TOut);
    570         TOut << ", ";
    571       }
    572     }
    573 
    574     FunctionTemplateSpecializationInfo *FSI
    575                                           = FD->getTemplateSpecializationInfo();
    576     if (FSI && !FSI->isExplicitSpecialization()) {
    577       const TemplateParameterList* Params
    578                                   = FSI->getTemplate()->getTemplateParameters();
    579       const TemplateArgumentList* Args = FSI->TemplateArguments;
    580       assert(Params->size() == Args->size());
    581       for (unsigned i = 0, e = Params->size(); i != e; ++i) {
    582         StringRef Param = Params->getParam(i)->getName();
    583         if (Param.empty()) continue;
    584         TOut << Param << " = ";
    585         Args->get(i).print(Policy, TOut);
    586         TOut << ", ";
    587       }
    588     }
    589 
    590     TOut.flush();
    591     if (!TemplateParams.empty()) {
    592       // remove the trailing comma and space
    593       TemplateParams.resize(TemplateParams.size() - 2);
    594       POut << " [" << TemplateParams << "]";
    595     }
    596 
    597     POut.flush();
    598 
    599     // Print "auto" for all deduced return types. This includes C++1y return
    600     // type deduction and lambdas. For trailing return types resolve the
    601     // decltype expression. Otherwise print the real type when this is
    602     // not a constructor or destructor.
    603     if ((isa<CXXMethodDecl>(FD) &&
    604          cast<CXXMethodDecl>(FD)->getParent()->isLambda()) ||
    605         (FT && FT->getReturnType()->getAs<AutoType>()))
    606       Proto = "auto " + Proto;
    607     else if (FT && FT->getReturnType()->getAs<DecltypeType>())
    608       FT->getReturnType()
    609           ->getAs<DecltypeType>()
    610           ->getUnderlyingType()
    611           .getAsStringInternal(Proto, Policy);
    612     else if (!isa<CXXConstructorDecl>(FD) && !isa<CXXDestructorDecl>(FD))
    613       AFT->getReturnType().getAsStringInternal(Proto, Policy);
    614 
    615     Out << Proto;
    616 
    617     Out.flush();
    618     return Name.str().str();
    619   }
    620   if (const CapturedDecl *CD = dyn_cast<CapturedDecl>(CurrentDecl)) {
    621     for (const DeclContext *DC = CD->getParent(); DC; DC = DC->getParent())
    622       // Skip to its enclosing function or method, but not its enclosing
    623       // CapturedDecl.
    624       if (DC->isFunctionOrMethod() && (DC->getDeclKind() != Decl::Captured)) {
    625         const Decl *D = Decl::castFromDeclContext(DC);
    626         return ComputeName(IT, D);
    627       }
    628     llvm_unreachable("CapturedDecl not inside a function or method");
    629   }
    630   if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurrentDecl)) {
    631     SmallString<256> Name;
    632     llvm::raw_svector_ostream Out(Name);
    633     Out << (MD->isInstanceMethod() ? '-' : '+');
    634     Out << '[';
    635 
    636     // For incorrect code, there might not be an ObjCInterfaceDecl.  Do
    637     // a null check to avoid a crash.
    638     if (const ObjCInterfaceDecl *ID = MD->getClassInterface())
    639       Out << *ID;
    640 
    641     if (const ObjCCategoryImplDecl *CID =
    642         dyn_cast<ObjCCategoryImplDecl>(MD->getDeclContext()))
    643       Out << '(' << *CID << ')';
    644 
    645     Out <<  ' ';
    646     MD->getSelector().print(Out);
    647     Out <<  ']';
    648 
    649     Out.flush();
    650     return Name.str().str();
    651   }
    652   if (isa<TranslationUnitDecl>(CurrentDecl) && IT == PrettyFunction) {
    653     // __PRETTY_FUNCTION__ -> "top level", the others produce an empty string.
    654     return "top level";
    655   }
    656   return "";
    657 }
    658 
    659 void APNumericStorage::setIntValue(const ASTContext &C,
    660                                    const llvm::APInt &Val) {
    661   if (hasAllocation())
    662     C.Deallocate(pVal);
    663 
    664   BitWidth = Val.getBitWidth();
    665   unsigned NumWords = Val.getNumWords();
    666   const uint64_t* Words = Val.getRawData();
    667   if (NumWords > 1) {
    668     pVal = new (C) uint64_t[NumWords];
    669     std::copy(Words, Words + NumWords, pVal);
    670   } else if (NumWords == 1)
    671     VAL = Words[0];
    672   else
    673     VAL = 0;
    674 }
    675 
    676 IntegerLiteral::IntegerLiteral(const ASTContext &C, const llvm::APInt &V,
    677                                QualType type, SourceLocation l)
    678   : Expr(IntegerLiteralClass, type, VK_RValue, OK_Ordinary, false, false,
    679          false, false),
    680     Loc(l) {
    681   assert(type->isIntegerType() && "Illegal type in IntegerLiteral");
    682   assert(V.getBitWidth() == C.getIntWidth(type) &&
    683          "Integer type is not the correct size for constant.");
    684   setValue(C, V);
    685 }
    686 
    687 IntegerLiteral *
    688 IntegerLiteral::Create(const ASTContext &C, const llvm::APInt &V,
    689                        QualType type, SourceLocation l) {
    690   return new (C) IntegerLiteral(C, V, type, l);
    691 }
    692 
    693 IntegerLiteral *
    694 IntegerLiteral::Create(const ASTContext &C, EmptyShell Empty) {
    695   return new (C) IntegerLiteral(Empty);
    696 }
    697 
    698 FloatingLiteral::FloatingLiteral(const ASTContext &C, const llvm::APFloat &V,
    699                                  bool isexact, QualType Type, SourceLocation L)
    700   : Expr(FloatingLiteralClass, Type, VK_RValue, OK_Ordinary, false, false,
    701          false, false), Loc(L) {
    702   setSemantics(V.getSemantics());
    703   FloatingLiteralBits.IsExact = isexact;
    704   setValue(C, V);
    705 }
    706 
    707 FloatingLiteral::FloatingLiteral(const ASTContext &C, EmptyShell Empty)
    708   : Expr(FloatingLiteralClass, Empty) {
    709   setRawSemantics(IEEEhalf);
    710   FloatingLiteralBits.IsExact = false;
    711 }
    712 
    713 FloatingLiteral *
    714 FloatingLiteral::Create(const ASTContext &C, const llvm::APFloat &V,
    715                         bool isexact, QualType Type, SourceLocation L) {
    716   return new (C) FloatingLiteral(C, V, isexact, Type, L);
    717 }
    718 
    719 FloatingLiteral *
    720 FloatingLiteral::Create(const ASTContext &C, EmptyShell Empty) {
    721   return new (C) FloatingLiteral(C, Empty);
    722 }
    723 
    724 const llvm::fltSemantics &FloatingLiteral::getSemantics() const {
    725   switch(FloatingLiteralBits.Semantics) {
    726   case IEEEhalf:
    727     return llvm::APFloat::IEEEhalf;
    728   case IEEEsingle:
    729     return llvm::APFloat::IEEEsingle;
    730   case IEEEdouble:
    731     return llvm::APFloat::IEEEdouble;
    732   case x87DoubleExtended:
    733     return llvm::APFloat::x87DoubleExtended;
    734   case IEEEquad:
    735     return llvm::APFloat::IEEEquad;
    736   case PPCDoubleDouble:
    737     return llvm::APFloat::PPCDoubleDouble;
    738   }
    739   llvm_unreachable("Unrecognised floating semantics");
    740 }
    741 
    742 void FloatingLiteral::setSemantics(const llvm::fltSemantics &Sem) {
    743   if (&Sem == &llvm::APFloat::IEEEhalf)
    744     FloatingLiteralBits.Semantics = IEEEhalf;
    745   else if (&Sem == &llvm::APFloat::IEEEsingle)
    746     FloatingLiteralBits.Semantics = IEEEsingle;
    747   else if (&Sem == &llvm::APFloat::IEEEdouble)
    748     FloatingLiteralBits.Semantics = IEEEdouble;
    749   else if (&Sem == &llvm::APFloat::x87DoubleExtended)
    750     FloatingLiteralBits.Semantics = x87DoubleExtended;
    751   else if (&Sem == &llvm::APFloat::IEEEquad)
    752     FloatingLiteralBits.Semantics = IEEEquad;
    753   else if (&Sem == &llvm::APFloat::PPCDoubleDouble)
    754     FloatingLiteralBits.Semantics = PPCDoubleDouble;
    755   else
    756     llvm_unreachable("Unknown floating semantics");
    757 }
    758 
    759 /// getValueAsApproximateDouble - This returns the value as an inaccurate
    760 /// double.  Note that this may cause loss of precision, but is useful for
    761 /// debugging dumps, etc.
    762 double FloatingLiteral::getValueAsApproximateDouble() const {
    763   llvm::APFloat V = getValue();
    764   bool ignored;
    765   V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
    766             &ignored);
    767   return V.convertToDouble();
    768 }
    769 
    770 int StringLiteral::mapCharByteWidth(TargetInfo const &target,StringKind k) {
    771   int CharByteWidth = 0;
    772   switch(k) {
    773     case Ascii:
    774     case UTF8:
    775       CharByteWidth = target.getCharWidth();
    776       break;
    777     case Wide:
    778       CharByteWidth = target.getWCharWidth();
    779       break;
    780     case UTF16:
    781       CharByteWidth = target.getChar16Width();
    782       break;
    783     case UTF32:
    784       CharByteWidth = target.getChar32Width();
    785       break;
    786   }
    787   assert((CharByteWidth & 7) == 0 && "Assumes character size is byte multiple");
    788   CharByteWidth /= 8;
    789   assert((CharByteWidth==1 || CharByteWidth==2 || CharByteWidth==4)
    790          && "character byte widths supported are 1, 2, and 4 only");
    791   return CharByteWidth;
    792 }
    793 
    794 StringLiteral *StringLiteral::Create(const ASTContext &C, StringRef Str,
    795                                      StringKind Kind, bool Pascal, QualType Ty,
    796                                      const SourceLocation *Loc,
    797                                      unsigned NumStrs) {
    798   assert(C.getAsConstantArrayType(Ty) &&
    799          "StringLiteral must be of constant array type!");
    800 
    801   // Allocate enough space for the StringLiteral plus an array of locations for
    802   // any concatenated string tokens.
    803   void *Mem = C.Allocate(sizeof(StringLiteral)+
    804                          sizeof(SourceLocation)*(NumStrs-1),
    805                          llvm::alignOf<StringLiteral>());
    806   StringLiteral *SL = new (Mem) StringLiteral(Ty);
    807 
    808   // OPTIMIZE: could allocate this appended to the StringLiteral.
    809   SL->setString(C,Str,Kind,Pascal);
    810 
    811   SL->TokLocs[0] = Loc[0];
    812   SL->NumConcatenated = NumStrs;
    813 
    814   if (NumStrs != 1)
    815     memcpy(&SL->TokLocs[1], Loc+1, sizeof(SourceLocation)*(NumStrs-1));
    816   return SL;
    817 }
    818 
    819 StringLiteral *StringLiteral::CreateEmpty(const ASTContext &C,
    820                                           unsigned NumStrs) {
    821   void *Mem = C.Allocate(sizeof(StringLiteral)+
    822                          sizeof(SourceLocation)*(NumStrs-1),
    823                          llvm::alignOf<StringLiteral>());
    824   StringLiteral *SL = new (Mem) StringLiteral(QualType());
    825   SL->CharByteWidth = 0;
    826   SL->Length = 0;
    827   SL->NumConcatenated = NumStrs;
    828   return SL;
    829 }
    830 
    831 void StringLiteral::outputString(raw_ostream &OS) const {
    832   switch (getKind()) {
    833   case Ascii: break; // no prefix.
    834   case Wide:  OS << 'L'; break;
    835   case UTF8:  OS << "u8"; break;
    836   case UTF16: OS << 'u'; break;
    837   case UTF32: OS << 'U'; break;
    838   }
    839   OS << '"';
    840   static const char Hex[] = "0123456789ABCDEF";
    841 
    842   unsigned LastSlashX = getLength();
    843   for (unsigned I = 0, N = getLength(); I != N; ++I) {
    844     switch (uint32_t Char = getCodeUnit(I)) {
    845     default:
    846       // FIXME: Convert UTF-8 back to codepoints before rendering.
    847 
    848       // Convert UTF-16 surrogate pairs back to codepoints before rendering.
    849       // Leave invalid surrogates alone; we'll use \x for those.
    850       if (getKind() == UTF16 && I != N - 1 && Char >= 0xd800 &&
    851           Char <= 0xdbff) {
    852         uint32_t Trail = getCodeUnit(I + 1);
    853         if (Trail >= 0xdc00 && Trail <= 0xdfff) {
    854           Char = 0x10000 + ((Char - 0xd800) << 10) + (Trail - 0xdc00);
    855           ++I;
    856         }
    857       }
    858 
    859       if (Char > 0xff) {
    860         // If this is a wide string, output characters over 0xff using \x
    861         // escapes. Otherwise, this is a UTF-16 or UTF-32 string, and Char is a
    862         // codepoint: use \x escapes for invalid codepoints.
    863         if (getKind() == Wide ||
    864             (Char >= 0xd800 && Char <= 0xdfff) || Char >= 0x110000) {
    865           // FIXME: Is this the best way to print wchar_t?
    866           OS << "\\x";
    867           int Shift = 28;
    868           while ((Char >> Shift) == 0)
    869             Shift -= 4;
    870           for (/**/; Shift >= 0; Shift -= 4)
    871             OS << Hex[(Char >> Shift) & 15];
    872           LastSlashX = I;
    873           break;
    874         }
    875 
    876         if (Char > 0xffff)
    877           OS << "\\U00"
    878              << Hex[(Char >> 20) & 15]
    879              << Hex[(Char >> 16) & 15];
    880         else
    881           OS << "\\u";
    882         OS << Hex[(Char >> 12) & 15]
    883            << Hex[(Char >>  8) & 15]
    884            << Hex[(Char >>  4) & 15]
    885            << Hex[(Char >>  0) & 15];
    886         break;
    887       }
    888 
    889       // If we used \x... for the previous character, and this character is a
    890       // hexadecimal digit, prevent it being slurped as part of the \x.
    891       if (LastSlashX + 1 == I) {
    892         switch (Char) {
    893           case '0': case '1': case '2': case '3': case '4':
    894           case '5': case '6': case '7': case '8': case '9':
    895           case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
    896           case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
    897             OS << "\"\"";
    898         }
    899       }
    900 
    901       assert(Char <= 0xff &&
    902              "Characters above 0xff should already have been handled.");
    903 
    904       if (isPrintable(Char))
    905         OS << (char)Char;
    906       else  // Output anything hard as an octal escape.
    907         OS << '\\'
    908            << (char)('0' + ((Char >> 6) & 7))
    909            << (char)('0' + ((Char >> 3) & 7))
    910            << (char)('0' + ((Char >> 0) & 7));
    911       break;
    912     // Handle some common non-printable cases to make dumps prettier.
    913     case '\\': OS << "\\\\"; break;
    914     case '"': OS << "\\\""; break;
    915     case '\n': OS << "\\n"; break;
    916     case '\t': OS << "\\t"; break;
    917     case '\a': OS << "\\a"; break;
    918     case '\b': OS << "\\b"; break;
    919     }
    920   }
    921   OS << '"';
    922 }
    923 
    924 void StringLiteral::setString(const ASTContext &C, StringRef Str,
    925                               StringKind Kind, bool IsPascal) {
    926   //FIXME: we assume that the string data comes from a target that uses the same
    927   // code unit size and endianess for the type of string.
    928   this->Kind = Kind;
    929   this->IsPascal = IsPascal;
    930 
    931   CharByteWidth = mapCharByteWidth(C.getTargetInfo(),Kind);
    932   assert((Str.size()%CharByteWidth == 0)
    933          && "size of data must be multiple of CharByteWidth");
    934   Length = Str.size()/CharByteWidth;
    935 
    936   switch(CharByteWidth) {
    937     case 1: {
    938       char *AStrData = new (C) char[Length];
    939       std::memcpy(AStrData,Str.data(),Length*sizeof(*AStrData));
    940       StrData.asChar = AStrData;
    941       break;
    942     }
    943     case 2: {
    944       uint16_t *AStrData = new (C) uint16_t[Length];
    945       std::memcpy(AStrData,Str.data(),Length*sizeof(*AStrData));
    946       StrData.asUInt16 = AStrData;
    947       break;
    948     }
    949     case 4: {
    950       uint32_t *AStrData = new (C) uint32_t[Length];
    951       std::memcpy(AStrData,Str.data(),Length*sizeof(*AStrData));
    952       StrData.asUInt32 = AStrData;
    953       break;
    954     }
    955     default:
    956       assert(false && "unsupported CharByteWidth");
    957   }
    958 }
    959 
    960 /// getLocationOfByte - Return a source location that points to the specified
    961 /// byte of this string literal.
    962 ///
    963 /// Strings are amazingly complex.  They can be formed from multiple tokens and
    964 /// can have escape sequences in them in addition to the usual trigraph and
    965 /// escaped newline business.  This routine handles this complexity.
    966 ///
    967 SourceLocation StringLiteral::
    968 getLocationOfByte(unsigned ByteNo, const SourceManager &SM,
    969                   const LangOptions &Features, const TargetInfo &Target) const {
    970   assert((Kind == StringLiteral::Ascii || Kind == StringLiteral::UTF8) &&
    971          "Only narrow string literals are currently supported");
    972 
    973   // Loop over all of the tokens in this string until we find the one that
    974   // contains the byte we're looking for.
    975   unsigned TokNo = 0;
    976   while (1) {
    977     assert(TokNo < getNumConcatenated() && "Invalid byte number!");
    978     SourceLocation StrTokLoc = getStrTokenLoc(TokNo);
    979 
    980     // Get the spelling of the string so that we can get the data that makes up
    981     // the string literal, not the identifier for the macro it is potentially
    982     // expanded through.
    983     SourceLocation StrTokSpellingLoc = SM.getSpellingLoc(StrTokLoc);
    984 
    985     // Re-lex the token to get its length and original spelling.
    986     std::pair<FileID, unsigned> LocInfo =SM.getDecomposedLoc(StrTokSpellingLoc);
    987     bool Invalid = false;
    988     StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
    989     if (Invalid)
    990       return StrTokSpellingLoc;
    991 
    992     const char *StrData = Buffer.data()+LocInfo.second;
    993 
    994     // Create a lexer starting at the beginning of this token.
    995     Lexer TheLexer(SM.getLocForStartOfFile(LocInfo.first), Features,
    996                    Buffer.begin(), StrData, Buffer.end());
    997     Token TheTok;
    998     TheLexer.LexFromRawLexer(TheTok);
    999 
   1000     // Use the StringLiteralParser to compute the length of the string in bytes.
   1001     StringLiteralParser SLP(TheTok, SM, Features, Target);
   1002     unsigned TokNumBytes = SLP.GetStringLength();
   1003 
   1004     // If the byte is in this token, return the location of the byte.
   1005     if (ByteNo < TokNumBytes ||
   1006         (ByteNo == TokNumBytes && TokNo == getNumConcatenated() - 1)) {
   1007       unsigned Offset = SLP.getOffsetOfStringByte(TheTok, ByteNo);
   1008 
   1009       // Now that we know the offset of the token in the spelling, use the
   1010       // preprocessor to get the offset in the original source.
   1011       return Lexer::AdvanceToTokenCharacter(StrTokLoc, Offset, SM, Features);
   1012     }
   1013 
   1014     // Move to the next string token.
   1015     ++TokNo;
   1016     ByteNo -= TokNumBytes;
   1017   }
   1018 }
   1019 
   1020 
   1021 
   1022 /// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
   1023 /// corresponds to, e.g. "sizeof" or "[pre]++".
   1024 StringRef UnaryOperator::getOpcodeStr(Opcode Op) {
   1025   switch (Op) {
   1026   case UO_PostInc: return "++";
   1027   case UO_PostDec: return "--";
   1028   case UO_PreInc:  return "++";
   1029   case UO_PreDec:  return "--";
   1030   case UO_AddrOf:  return "&";
   1031   case UO_Deref:   return "*";
   1032   case UO_Plus:    return "+";
   1033   case UO_Minus:   return "-";
   1034   case UO_Not:     return "~";
   1035   case UO_LNot:    return "!";
   1036   case UO_Real:    return "__real";
   1037   case UO_Imag:    return "__imag";
   1038   case UO_Extension: return "__extension__";
   1039   }
   1040   llvm_unreachable("Unknown unary operator");
   1041 }
   1042 
   1043 UnaryOperatorKind
   1044 UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
   1045   switch (OO) {
   1046   default: llvm_unreachable("No unary operator for overloaded function");
   1047   case OO_PlusPlus:   return Postfix ? UO_PostInc : UO_PreInc;
   1048   case OO_MinusMinus: return Postfix ? UO_PostDec : UO_PreDec;
   1049   case OO_Amp:        return UO_AddrOf;
   1050   case OO_Star:       return UO_Deref;
   1051   case OO_Plus:       return UO_Plus;
   1052   case OO_Minus:      return UO_Minus;
   1053   case OO_Tilde:      return UO_Not;
   1054   case OO_Exclaim:    return UO_LNot;
   1055   }
   1056 }
   1057 
   1058 OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
   1059   switch (Opc) {
   1060   case UO_PostInc: case UO_PreInc: return OO_PlusPlus;
   1061   case UO_PostDec: case UO_PreDec: return OO_MinusMinus;
   1062   case UO_AddrOf: return OO_Amp;
   1063   case UO_Deref: return OO_Star;
   1064   case UO_Plus: return OO_Plus;
   1065   case UO_Minus: return OO_Minus;
   1066   case UO_Not: return OO_Tilde;
   1067   case UO_LNot: return OO_Exclaim;
   1068   default: return OO_None;
   1069   }
   1070 }
   1071 
   1072 
   1073 //===----------------------------------------------------------------------===//
   1074 // Postfix Operators.
   1075 //===----------------------------------------------------------------------===//
   1076 
   1077 CallExpr::CallExpr(const ASTContext& C, StmtClass SC, Expr *fn,
   1078                    unsigned NumPreArgs, ArrayRef<Expr*> args, QualType t,
   1079                    ExprValueKind VK, SourceLocation rparenloc)
   1080   : Expr(SC, t, VK, OK_Ordinary,
   1081          fn->isTypeDependent(),
   1082          fn->isValueDependent(),
   1083          fn->isInstantiationDependent(),
   1084          fn->containsUnexpandedParameterPack()),
   1085     NumArgs(args.size()) {
   1086 
   1087   SubExprs = new (C) Stmt*[args.size()+PREARGS_START+NumPreArgs];
   1088   SubExprs[FN] = fn;
   1089   for (unsigned i = 0; i != args.size(); ++i) {
   1090     if (args[i]->isTypeDependent())
   1091       ExprBits.TypeDependent = true;
   1092     if (args[i]->isValueDependent())
   1093       ExprBits.ValueDependent = true;
   1094     if (args[i]->isInstantiationDependent())
   1095       ExprBits.InstantiationDependent = true;
   1096     if (args[i]->containsUnexpandedParameterPack())
   1097       ExprBits.ContainsUnexpandedParameterPack = true;
   1098 
   1099     SubExprs[i+PREARGS_START+NumPreArgs] = args[i];
   1100   }
   1101 
   1102   CallExprBits.NumPreArgs = NumPreArgs;
   1103   RParenLoc = rparenloc;
   1104 }
   1105 
   1106 CallExpr::CallExpr(const ASTContext& C, Expr *fn, ArrayRef<Expr*> args,
   1107                    QualType t, ExprValueKind VK, SourceLocation rparenloc)
   1108   : Expr(CallExprClass, t, VK, OK_Ordinary,
   1109          fn->isTypeDependent(),
   1110          fn->isValueDependent(),
   1111          fn->isInstantiationDependent(),
   1112          fn->containsUnexpandedParameterPack()),
   1113     NumArgs(args.size()) {
   1114 
   1115   SubExprs = new (C) Stmt*[args.size()+PREARGS_START];
   1116   SubExprs[FN] = fn;
   1117   for (unsigned i = 0; i != args.size(); ++i) {
   1118     if (args[i]->isTypeDependent())
   1119       ExprBits.TypeDependent = true;
   1120     if (args[i]->isValueDependent())
   1121       ExprBits.ValueDependent = true;
   1122     if (args[i]->isInstantiationDependent())
   1123       ExprBits.InstantiationDependent = true;
   1124     if (args[i]->containsUnexpandedParameterPack())
   1125       ExprBits.ContainsUnexpandedParameterPack = true;
   1126 
   1127     SubExprs[i+PREARGS_START] = args[i];
   1128   }
   1129 
   1130   CallExprBits.NumPreArgs = 0;
   1131   RParenLoc = rparenloc;
   1132 }
   1133 
   1134 CallExpr::CallExpr(const ASTContext &C, StmtClass SC, EmptyShell Empty)
   1135   : Expr(SC, Empty), SubExprs(nullptr), NumArgs(0) {
   1136   // FIXME: Why do we allocate this?
   1137   SubExprs = new (C) Stmt*[PREARGS_START];
   1138   CallExprBits.NumPreArgs = 0;
   1139 }
   1140 
   1141 CallExpr::CallExpr(const ASTContext &C, StmtClass SC, unsigned NumPreArgs,
   1142                    EmptyShell Empty)
   1143   : Expr(SC, Empty), SubExprs(nullptr), NumArgs(0) {
   1144   // FIXME: Why do we allocate this?
   1145   SubExprs = new (C) Stmt*[PREARGS_START+NumPreArgs];
   1146   CallExprBits.NumPreArgs = NumPreArgs;
   1147 }
   1148 
   1149 Decl *CallExpr::getCalleeDecl() {
   1150   Expr *CEE = getCallee()->IgnoreParenImpCasts();
   1151 
   1152   while (SubstNonTypeTemplateParmExpr *NTTP
   1153                                 = dyn_cast<SubstNonTypeTemplateParmExpr>(CEE)) {
   1154     CEE = NTTP->getReplacement()->IgnoreParenCasts();
   1155   }
   1156 
   1157   // If we're calling a dereference, look at the pointer instead.
   1158   if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
   1159     if (BO->isPtrMemOp())
   1160       CEE = BO->getRHS()->IgnoreParenCasts();
   1161   } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
   1162     if (UO->getOpcode() == UO_Deref)
   1163       CEE = UO->getSubExpr()->IgnoreParenCasts();
   1164   }
   1165   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
   1166     return DRE->getDecl();
   1167   if (MemberExpr *ME = dyn_cast<MemberExpr>(CEE))
   1168     return ME->getMemberDecl();
   1169 
   1170   return nullptr;
   1171 }
   1172 
   1173 FunctionDecl *CallExpr::getDirectCallee() {
   1174   return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
   1175 }
   1176 
   1177 /// setNumArgs - This changes the number of arguments present in this call.
   1178 /// Any orphaned expressions are deleted by this, and any new operands are set
   1179 /// to null.
   1180 void CallExpr::setNumArgs(const ASTContext& C, unsigned NumArgs) {
   1181   // No change, just return.
   1182   if (NumArgs == getNumArgs()) return;
   1183 
   1184   // If shrinking # arguments, just delete the extras and forgot them.
   1185   if (NumArgs < getNumArgs()) {
   1186     this->NumArgs = NumArgs;
   1187     return;
   1188   }
   1189 
   1190   // Otherwise, we are growing the # arguments.  New an bigger argument array.
   1191   unsigned NumPreArgs = getNumPreArgs();
   1192   Stmt **NewSubExprs = new (C) Stmt*[NumArgs+PREARGS_START+NumPreArgs];
   1193   // Copy over args.
   1194   for (unsigned i = 0; i != getNumArgs()+PREARGS_START+NumPreArgs; ++i)
   1195     NewSubExprs[i] = SubExprs[i];
   1196   // Null out new args.
   1197   for (unsigned i = getNumArgs()+PREARGS_START+NumPreArgs;
   1198        i != NumArgs+PREARGS_START+NumPreArgs; ++i)
   1199     NewSubExprs[i] = nullptr;
   1200 
   1201   if (SubExprs) C.Deallocate(SubExprs);
   1202   SubExprs = NewSubExprs;
   1203   this->NumArgs = NumArgs;
   1204 }
   1205 
   1206 /// getBuiltinCallee - If this is a call to a builtin, return the builtin ID. If
   1207 /// not, return 0.
   1208 unsigned CallExpr::getBuiltinCallee() const {
   1209   // All simple function calls (e.g. func()) are implicitly cast to pointer to
   1210   // function. As a result, we try and obtain the DeclRefExpr from the
   1211   // ImplicitCastExpr.
   1212   const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
   1213   if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
   1214     return 0;
   1215 
   1216   const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
   1217   if (!DRE)
   1218     return 0;
   1219 
   1220   const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
   1221   if (!FDecl)
   1222     return 0;
   1223 
   1224   if (!FDecl->getIdentifier())
   1225     return 0;
   1226 
   1227   return FDecl->getBuiltinID();
   1228 }
   1229 
   1230 bool CallExpr::isUnevaluatedBuiltinCall(ASTContext &Ctx) const {
   1231   if (unsigned BI = getBuiltinCallee())
   1232     return Ctx.BuiltinInfo.isUnevaluated(BI);
   1233   return false;
   1234 }
   1235 
   1236 QualType CallExpr::getCallReturnType() const {
   1237   QualType CalleeType = getCallee()->getType();
   1238   if (const PointerType *FnTypePtr = CalleeType->getAs<PointerType>())
   1239     CalleeType = FnTypePtr->getPointeeType();
   1240   else if (const BlockPointerType *BPT = CalleeType->getAs<BlockPointerType>())
   1241     CalleeType = BPT->getPointeeType();
   1242   else if (CalleeType->isSpecificPlaceholderType(BuiltinType::BoundMember))
   1243     // This should never be overloaded and so should never return null.
   1244     CalleeType = Expr::findBoundMemberType(getCallee());
   1245 
   1246   const FunctionType *FnType = CalleeType->castAs<FunctionType>();
   1247   return FnType->getReturnType();
   1248 }
   1249 
   1250 SourceLocation CallExpr::getLocStart() const {
   1251   if (isa<CXXOperatorCallExpr>(this))
   1252     return cast<CXXOperatorCallExpr>(this)->getLocStart();
   1253 
   1254   SourceLocation begin = getCallee()->getLocStart();
   1255   if (begin.isInvalid() && getNumArgs() > 0)
   1256     begin = getArg(0)->getLocStart();
   1257   return begin;
   1258 }
   1259 SourceLocation CallExpr::getLocEnd() const {
   1260   if (isa<CXXOperatorCallExpr>(this))
   1261     return cast<CXXOperatorCallExpr>(this)->getLocEnd();
   1262 
   1263   SourceLocation end = getRParenLoc();
   1264   if (end.isInvalid() && getNumArgs() > 0)
   1265     end = getArg(getNumArgs() - 1)->getLocEnd();
   1266   return end;
   1267 }
   1268 
   1269 OffsetOfExpr *OffsetOfExpr::Create(const ASTContext &C, QualType type,
   1270                                    SourceLocation OperatorLoc,
   1271                                    TypeSourceInfo *tsi,
   1272                                    ArrayRef<OffsetOfNode> comps,
   1273                                    ArrayRef<Expr*> exprs,
   1274                                    SourceLocation RParenLoc) {
   1275   void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
   1276                          sizeof(OffsetOfNode) * comps.size() +
   1277                          sizeof(Expr*) * exprs.size());
   1278 
   1279   return new (Mem) OffsetOfExpr(C, type, OperatorLoc, tsi, comps, exprs,
   1280                                 RParenLoc);
   1281 }
   1282 
   1283 OffsetOfExpr *OffsetOfExpr::CreateEmpty(const ASTContext &C,
   1284                                         unsigned numComps, unsigned numExprs) {
   1285   void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
   1286                          sizeof(OffsetOfNode) * numComps +
   1287                          sizeof(Expr*) * numExprs);
   1288   return new (Mem) OffsetOfExpr(numComps, numExprs);
   1289 }
   1290 
   1291 OffsetOfExpr::OffsetOfExpr(const ASTContext &C, QualType type,
   1292                            SourceLocation OperatorLoc, TypeSourceInfo *tsi,
   1293                            ArrayRef<OffsetOfNode> comps, ArrayRef<Expr*> exprs,
   1294                            SourceLocation RParenLoc)
   1295   : Expr(OffsetOfExprClass, type, VK_RValue, OK_Ordinary,
   1296          /*TypeDependent=*/false,
   1297          /*ValueDependent=*/tsi->getType()->isDependentType(),
   1298          tsi->getType()->isInstantiationDependentType(),
   1299          tsi->getType()->containsUnexpandedParameterPack()),
   1300     OperatorLoc(OperatorLoc), RParenLoc(RParenLoc), TSInfo(tsi),
   1301     NumComps(comps.size()), NumExprs(exprs.size())
   1302 {
   1303   for (unsigned i = 0; i != comps.size(); ++i) {
   1304     setComponent(i, comps[i]);
   1305   }
   1306 
   1307   for (unsigned i = 0; i != exprs.size(); ++i) {
   1308     if (exprs[i]->isTypeDependent() || exprs[i]->isValueDependent())
   1309       ExprBits.ValueDependent = true;
   1310     if (exprs[i]->containsUnexpandedParameterPack())
   1311       ExprBits.ContainsUnexpandedParameterPack = true;
   1312 
   1313     setIndexExpr(i, exprs[i]);
   1314   }
   1315 }
   1316 
   1317 IdentifierInfo *OffsetOfExpr::OffsetOfNode::getFieldName() const {
   1318   assert(getKind() == Field || getKind() == Identifier);
   1319   if (getKind() == Field)
   1320     return getField()->getIdentifier();
   1321 
   1322   return reinterpret_cast<IdentifierInfo *> (Data & ~(uintptr_t)Mask);
   1323 }
   1324 
   1325 MemberExpr *MemberExpr::Create(const ASTContext &C, Expr *base, bool isarrow,
   1326                                NestedNameSpecifierLoc QualifierLoc,
   1327                                SourceLocation TemplateKWLoc,
   1328                                ValueDecl *memberdecl,
   1329                                DeclAccessPair founddecl,
   1330                                DeclarationNameInfo nameinfo,
   1331                                const TemplateArgumentListInfo *targs,
   1332                                QualType ty,
   1333                                ExprValueKind vk,
   1334                                ExprObjectKind ok) {
   1335   std::size_t Size = sizeof(MemberExpr);
   1336 
   1337   bool hasQualOrFound = (QualifierLoc ||
   1338                          founddecl.getDecl() != memberdecl ||
   1339                          founddecl.getAccess() != memberdecl->getAccess());
   1340   if (hasQualOrFound)
   1341     Size += sizeof(MemberNameQualifier);
   1342 
   1343   if (targs)
   1344     Size += ASTTemplateKWAndArgsInfo::sizeFor(targs->size());
   1345   else if (TemplateKWLoc.isValid())
   1346     Size += ASTTemplateKWAndArgsInfo::sizeFor(0);
   1347 
   1348   void *Mem = C.Allocate(Size, llvm::alignOf<MemberExpr>());
   1349   MemberExpr *E = new (Mem) MemberExpr(base, isarrow, memberdecl, nameinfo,
   1350                                        ty, vk, ok);
   1351 
   1352   if (hasQualOrFound) {
   1353     // FIXME: Wrong. We should be looking at the member declaration we found.
   1354     if (QualifierLoc && QualifierLoc.getNestedNameSpecifier()->isDependent()) {
   1355       E->setValueDependent(true);
   1356       E->setTypeDependent(true);
   1357       E->setInstantiationDependent(true);
   1358     }
   1359     else if (QualifierLoc &&
   1360              QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())
   1361       E->setInstantiationDependent(true);
   1362 
   1363     E->HasQualifierOrFoundDecl = true;
   1364 
   1365     MemberNameQualifier *NQ = E->getMemberQualifier();
   1366     NQ->QualifierLoc = QualifierLoc;
   1367     NQ->FoundDecl = founddecl;
   1368   }
   1369 
   1370   E->HasTemplateKWAndArgsInfo = (targs || TemplateKWLoc.isValid());
   1371 
   1372   if (targs) {
   1373     bool Dependent = false;
   1374     bool InstantiationDependent = false;
   1375     bool ContainsUnexpandedParameterPack = false;
   1376     E->getTemplateKWAndArgsInfo()->initializeFrom(TemplateKWLoc, *targs,
   1377                                                   Dependent,
   1378                                                   InstantiationDependent,
   1379                                              ContainsUnexpandedParameterPack);
   1380     if (InstantiationDependent)
   1381       E->setInstantiationDependent(true);
   1382   } else if (TemplateKWLoc.isValid()) {
   1383     E->getTemplateKWAndArgsInfo()->initializeFrom(TemplateKWLoc);
   1384   }
   1385 
   1386   return E;
   1387 }
   1388 
   1389 SourceLocation MemberExpr::getLocStart() const {
   1390   if (isImplicitAccess()) {
   1391     if (hasQualifier())
   1392       return getQualifierLoc().getBeginLoc();
   1393     return MemberLoc;
   1394   }
   1395 
   1396   // FIXME: We don't want this to happen. Rather, we should be able to
   1397   // detect all kinds of implicit accesses more cleanly.
   1398   SourceLocation BaseStartLoc = getBase()->getLocStart();
   1399   if (BaseStartLoc.isValid())
   1400     return BaseStartLoc;
   1401   return MemberLoc;
   1402 }
   1403 SourceLocation MemberExpr::getLocEnd() const {
   1404   SourceLocation EndLoc = getMemberNameInfo().getEndLoc();
   1405   if (hasExplicitTemplateArgs())
   1406     EndLoc = getRAngleLoc();
   1407   else if (EndLoc.isInvalid())
   1408     EndLoc = getBase()->getLocEnd();
   1409   return EndLoc;
   1410 }
   1411 
   1412 bool CastExpr::CastConsistency() const {
   1413   switch (getCastKind()) {
   1414   case CK_DerivedToBase:
   1415   case CK_UncheckedDerivedToBase:
   1416   case CK_DerivedToBaseMemberPointer:
   1417   case CK_BaseToDerived:
   1418   case CK_BaseToDerivedMemberPointer:
   1419     assert(!path_empty() && "Cast kind should have a base path!");
   1420     break;
   1421 
   1422   case CK_CPointerToObjCPointerCast:
   1423     assert(getType()->isObjCObjectPointerType());
   1424     assert(getSubExpr()->getType()->isPointerType());
   1425     goto CheckNoBasePath;
   1426 
   1427   case CK_BlockPointerToObjCPointerCast:
   1428     assert(getType()->isObjCObjectPointerType());
   1429     assert(getSubExpr()->getType()->isBlockPointerType());
   1430     goto CheckNoBasePath;
   1431 
   1432   case CK_ReinterpretMemberPointer:
   1433     assert(getType()->isMemberPointerType());
   1434     assert(getSubExpr()->getType()->isMemberPointerType());
   1435     goto CheckNoBasePath;
   1436 
   1437   case CK_BitCast:
   1438     // Arbitrary casts to C pointer types count as bitcasts.
   1439     // Otherwise, we should only have block and ObjC pointer casts
   1440     // here if they stay within the type kind.
   1441     if (!getType()->isPointerType()) {
   1442       assert(getType()->isObjCObjectPointerType() ==
   1443              getSubExpr()->getType()->isObjCObjectPointerType());
   1444       assert(getType()->isBlockPointerType() ==
   1445              getSubExpr()->getType()->isBlockPointerType());
   1446     }
   1447     goto CheckNoBasePath;
   1448 
   1449   case CK_AnyPointerToBlockPointerCast:
   1450     assert(getType()->isBlockPointerType());
   1451     assert(getSubExpr()->getType()->isAnyPointerType() &&
   1452            !getSubExpr()->getType()->isBlockPointerType());
   1453     goto CheckNoBasePath;
   1454 
   1455   case CK_CopyAndAutoreleaseBlockObject:
   1456     assert(getType()->isBlockPointerType());
   1457     assert(getSubExpr()->getType()->isBlockPointerType());
   1458     goto CheckNoBasePath;
   1459 
   1460   case CK_FunctionToPointerDecay:
   1461     assert(getType()->isPointerType());
   1462     assert(getSubExpr()->getType()->isFunctionType());
   1463     goto CheckNoBasePath;
   1464 
   1465   case CK_AddressSpaceConversion:
   1466     assert(getType()->isPointerType());
   1467     assert(getSubExpr()->getType()->isPointerType());
   1468     assert(getType()->getPointeeType().getAddressSpace() !=
   1469            getSubExpr()->getType()->getPointeeType().getAddressSpace());
   1470   // These should not have an inheritance path.
   1471   case CK_Dynamic:
   1472   case CK_ToUnion:
   1473   case CK_ArrayToPointerDecay:
   1474   case CK_NullToMemberPointer:
   1475   case CK_NullToPointer:
   1476   case CK_ConstructorConversion:
   1477   case CK_IntegralToPointer:
   1478   case CK_PointerToIntegral:
   1479   case CK_ToVoid:
   1480   case CK_VectorSplat:
   1481   case CK_IntegralCast:
   1482   case CK_IntegralToFloating:
   1483   case CK_FloatingToIntegral:
   1484   case CK_FloatingCast:
   1485   case CK_ObjCObjectLValueCast:
   1486   case CK_FloatingRealToComplex:
   1487   case CK_FloatingComplexToReal:
   1488   case CK_FloatingComplexCast:
   1489   case CK_FloatingComplexToIntegralComplex:
   1490   case CK_IntegralRealToComplex:
   1491   case CK_IntegralComplexToReal:
   1492   case CK_IntegralComplexCast:
   1493   case CK_IntegralComplexToFloatingComplex:
   1494   case CK_ARCProduceObject:
   1495   case CK_ARCConsumeObject:
   1496   case CK_ARCReclaimReturnedObject:
   1497   case CK_ARCExtendBlockObject:
   1498   case CK_ZeroToOCLEvent:
   1499     assert(!getType()->isBooleanType() && "unheralded conversion to bool");
   1500     goto CheckNoBasePath;
   1501 
   1502   case CK_Dependent:
   1503   case CK_LValueToRValue:
   1504   case CK_NoOp:
   1505   case CK_AtomicToNonAtomic:
   1506   case CK_NonAtomicToAtomic:
   1507   case CK_PointerToBoolean:
   1508   case CK_IntegralToBoolean:
   1509   case CK_FloatingToBoolean:
   1510   case CK_MemberPointerToBoolean:
   1511   case CK_FloatingComplexToBoolean:
   1512   case CK_IntegralComplexToBoolean:
   1513   case CK_LValueBitCast:            // -> bool&
   1514   case CK_UserDefinedConversion:    // operator bool()
   1515   case CK_BuiltinFnToFnPtr:
   1516   CheckNoBasePath:
   1517     assert(path_empty() && "Cast kind should not have a base path!");
   1518     break;
   1519   }
   1520   return true;
   1521 }
   1522 
   1523 const char *CastExpr::getCastKindName() const {
   1524   switch (getCastKind()) {
   1525   case CK_Dependent:
   1526     return "Dependent";
   1527   case CK_BitCast:
   1528     return "BitCast";
   1529   case CK_LValueBitCast:
   1530     return "LValueBitCast";
   1531   case CK_LValueToRValue:
   1532     return "LValueToRValue";
   1533   case CK_NoOp:
   1534     return "NoOp";
   1535   case CK_BaseToDerived:
   1536     return "BaseToDerived";
   1537   case CK_DerivedToBase:
   1538     return "DerivedToBase";
   1539   case CK_UncheckedDerivedToBase:
   1540     return "UncheckedDerivedToBase";
   1541   case CK_Dynamic:
   1542     return "Dynamic";
   1543   case CK_ToUnion:
   1544     return "ToUnion";
   1545   case CK_ArrayToPointerDecay:
   1546     return "ArrayToPointerDecay";
   1547   case CK_FunctionToPointerDecay:
   1548     return "FunctionToPointerDecay";
   1549   case CK_NullToMemberPointer:
   1550     return "NullToMemberPointer";
   1551   case CK_NullToPointer:
   1552     return "NullToPointer";
   1553   case CK_BaseToDerivedMemberPointer:
   1554     return "BaseToDerivedMemberPointer";
   1555   case CK_DerivedToBaseMemberPointer:
   1556     return "DerivedToBaseMemberPointer";
   1557   case CK_ReinterpretMemberPointer:
   1558     return "ReinterpretMemberPointer";
   1559   case CK_UserDefinedConversion:
   1560     return "UserDefinedConversion";
   1561   case CK_ConstructorConversion:
   1562     return "ConstructorConversion";
   1563   case CK_IntegralToPointer:
   1564     return "IntegralToPointer";
   1565   case CK_PointerToIntegral:
   1566     return "PointerToIntegral";
   1567   case CK_PointerToBoolean:
   1568     return "PointerToBoolean";
   1569   case CK_ToVoid:
   1570     return "ToVoid";
   1571   case CK_VectorSplat:
   1572     return "VectorSplat";
   1573   case CK_IntegralCast:
   1574     return "IntegralCast";
   1575   case CK_IntegralToBoolean:
   1576     return "IntegralToBoolean";
   1577   case CK_IntegralToFloating:
   1578     return "IntegralToFloating";
   1579   case CK_FloatingToIntegral:
   1580     return "FloatingToIntegral";
   1581   case CK_FloatingCast:
   1582     return "FloatingCast";
   1583   case CK_FloatingToBoolean:
   1584     return "FloatingToBoolean";
   1585   case CK_MemberPointerToBoolean:
   1586     return "MemberPointerToBoolean";
   1587   case CK_CPointerToObjCPointerCast:
   1588     return "CPointerToObjCPointerCast";
   1589   case CK_BlockPointerToObjCPointerCast:
   1590     return "BlockPointerToObjCPointerCast";
   1591   case CK_AnyPointerToBlockPointerCast:
   1592     return "AnyPointerToBlockPointerCast";
   1593   case CK_ObjCObjectLValueCast:
   1594     return "ObjCObjectLValueCast";
   1595   case CK_FloatingRealToComplex:
   1596     return "FloatingRealToComplex";
   1597   case CK_FloatingComplexToReal:
   1598     return "FloatingComplexToReal";
   1599   case CK_FloatingComplexToBoolean:
   1600     return "FloatingComplexToBoolean";
   1601   case CK_FloatingComplexCast:
   1602     return "FloatingComplexCast";
   1603   case CK_FloatingComplexToIntegralComplex:
   1604     return "FloatingComplexToIntegralComplex";
   1605   case CK_IntegralRealToComplex:
   1606     return "IntegralRealToComplex";
   1607   case CK_IntegralComplexToReal:
   1608     return "IntegralComplexToReal";
   1609   case CK_IntegralComplexToBoolean:
   1610     return "IntegralComplexToBoolean";
   1611   case CK_IntegralComplexCast:
   1612     return "IntegralComplexCast";
   1613   case CK_IntegralComplexToFloatingComplex:
   1614     return "IntegralComplexToFloatingComplex";
   1615   case CK_ARCConsumeObject:
   1616     return "ARCConsumeObject";
   1617   case CK_ARCProduceObject:
   1618     return "ARCProduceObject";
   1619   case CK_ARCReclaimReturnedObject:
   1620     return "ARCReclaimReturnedObject";
   1621   case CK_ARCExtendBlockObject:
   1622     return "ARCExtendBlockObject";
   1623   case CK_AtomicToNonAtomic:
   1624     return "AtomicToNonAtomic";
   1625   case CK_NonAtomicToAtomic:
   1626     return "NonAtomicToAtomic";
   1627   case CK_CopyAndAutoreleaseBlockObject:
   1628     return "CopyAndAutoreleaseBlockObject";
   1629   case CK_BuiltinFnToFnPtr:
   1630     return "BuiltinFnToFnPtr";
   1631   case CK_ZeroToOCLEvent:
   1632     return "ZeroToOCLEvent";
   1633   case CK_AddressSpaceConversion:
   1634     return "AddressSpaceConversion";
   1635   }
   1636 
   1637   llvm_unreachable("Unhandled cast kind!");
   1638 }
   1639 
   1640 Expr *CastExpr::getSubExprAsWritten() {
   1641   Expr *SubExpr = nullptr;
   1642   CastExpr *E = this;
   1643   do {
   1644     SubExpr = E->getSubExpr();
   1645 
   1646     // Skip through reference binding to temporary.
   1647     if (MaterializeTemporaryExpr *Materialize
   1648                                   = dyn_cast<MaterializeTemporaryExpr>(SubExpr))
   1649       SubExpr = Materialize->GetTemporaryExpr();
   1650 
   1651     // Skip any temporary bindings; they're implicit.
   1652     if (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(SubExpr))
   1653       SubExpr = Binder->getSubExpr();
   1654 
   1655     // Conversions by constructor and conversion functions have a
   1656     // subexpression describing the call; strip it off.
   1657     if (E->getCastKind() == CK_ConstructorConversion)
   1658       SubExpr = cast<CXXConstructExpr>(SubExpr)->getArg(0);
   1659     else if (E->getCastKind() == CK_UserDefinedConversion)
   1660       SubExpr = cast<CXXMemberCallExpr>(SubExpr)->getImplicitObjectArgument();
   1661 
   1662     // If the subexpression we're left with is an implicit cast, look
   1663     // through that, too.
   1664   } while ((E = dyn_cast<ImplicitCastExpr>(SubExpr)));
   1665 
   1666   return SubExpr;
   1667 }
   1668 
   1669 CXXBaseSpecifier **CastExpr::path_buffer() {
   1670   switch (getStmtClass()) {
   1671 #define ABSTRACT_STMT(x)
   1672 #define CASTEXPR(Type, Base) \
   1673   case Stmt::Type##Class: \
   1674     return reinterpret_cast<CXXBaseSpecifier**>(static_cast<Type*>(this)+1);
   1675 #define STMT(Type, Base)
   1676 #include "clang/AST/StmtNodes.inc"
   1677   default:
   1678     llvm_unreachable("non-cast expressions not possible here");
   1679   }
   1680 }
   1681 
   1682 void CastExpr::setCastPath(const CXXCastPath &Path) {
   1683   assert(Path.size() == path_size());
   1684   memcpy(path_buffer(), Path.data(), Path.size() * sizeof(CXXBaseSpecifier*));
   1685 }
   1686 
   1687 ImplicitCastExpr *ImplicitCastExpr::Create(const ASTContext &C, QualType T,
   1688                                            CastKind Kind, Expr *Operand,
   1689                                            const CXXCastPath *BasePath,
   1690                                            ExprValueKind VK) {
   1691   unsigned PathSize = (BasePath ? BasePath->size() : 0);
   1692   void *Buffer =
   1693     C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
   1694   ImplicitCastExpr *E =
   1695     new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
   1696   if (PathSize) E->setCastPath(*BasePath);
   1697   return E;
   1698 }
   1699 
   1700 ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(const ASTContext &C,
   1701                                                 unsigned PathSize) {
   1702   void *Buffer =
   1703     C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
   1704   return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
   1705 }
   1706 
   1707 
   1708 CStyleCastExpr *CStyleCastExpr::Create(const ASTContext &C, QualType T,
   1709                                        ExprValueKind VK, CastKind K, Expr *Op,
   1710                                        const CXXCastPath *BasePath,
   1711                                        TypeSourceInfo *WrittenTy,
   1712                                        SourceLocation L, SourceLocation R) {
   1713   unsigned PathSize = (BasePath ? BasePath->size() : 0);
   1714   void *Buffer =
   1715     C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
   1716   CStyleCastExpr *E =
   1717     new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
   1718   if (PathSize) E->setCastPath(*BasePath);
   1719   return E;
   1720 }
   1721 
   1722 CStyleCastExpr *CStyleCastExpr::CreateEmpty(const ASTContext &C,
   1723                                             unsigned PathSize) {
   1724   void *Buffer =
   1725     C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
   1726   return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
   1727 }
   1728 
   1729 /// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
   1730 /// corresponds to, e.g. "<<=".
   1731 StringRef BinaryOperator::getOpcodeStr(Opcode Op) {
   1732   switch (Op) {
   1733   case BO_PtrMemD:   return ".*";
   1734   case BO_PtrMemI:   return "->*";
   1735   case BO_Mul:       return "*";
   1736   case BO_Div:       return "/";
   1737   case BO_Rem:       return "%";
   1738   case BO_Add:       return "+";
   1739   case BO_Sub:       return "-";
   1740   case BO_Shl:       return "<<";
   1741   case BO_Shr:       return ">>";
   1742   case BO_LT:        return "<";
   1743   case BO_GT:        return ">";
   1744   case BO_LE:        return "<=";
   1745   case BO_GE:        return ">=";
   1746   case BO_EQ:        return "==";
   1747   case BO_NE:        return "!=";
   1748   case BO_And:       return "&";
   1749   case BO_Xor:       return "^";
   1750   case BO_Or:        return "|";
   1751   case BO_LAnd:      return "&&";
   1752   case BO_LOr:       return "||";
   1753   case BO_Assign:    return "=";
   1754   case BO_MulAssign: return "*=";
   1755   case BO_DivAssign: return "/=";
   1756   case BO_RemAssign: return "%=";
   1757   case BO_AddAssign: return "+=";
   1758   case BO_SubAssign: return "-=";
   1759   case BO_ShlAssign: return "<<=";
   1760   case BO_ShrAssign: return ">>=";
   1761   case BO_AndAssign: return "&=";
   1762   case BO_XorAssign: return "^=";
   1763   case BO_OrAssign:  return "|=";
   1764   case BO_Comma:     return ",";
   1765   }
   1766 
   1767   llvm_unreachable("Invalid OpCode!");
   1768 }
   1769 
   1770 BinaryOperatorKind
   1771 BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
   1772   switch (OO) {
   1773   default: llvm_unreachable("Not an overloadable binary operator");
   1774   case OO_Plus: return BO_Add;
   1775   case OO_Minus: return BO_Sub;
   1776   case OO_Star: return BO_Mul;
   1777   case OO_Slash: return BO_Div;
   1778   case OO_Percent: return BO_Rem;
   1779   case OO_Caret: return BO_Xor;
   1780   case OO_Amp: return BO_And;
   1781   case OO_Pipe: return BO_Or;
   1782   case OO_Equal: return BO_Assign;
   1783   case OO_Less: return BO_LT;
   1784   case OO_Greater: return BO_GT;
   1785   case OO_PlusEqual: return BO_AddAssign;
   1786   case OO_MinusEqual: return BO_SubAssign;
   1787   case OO_StarEqual: return BO_MulAssign;
   1788   case OO_SlashEqual: return BO_DivAssign;
   1789   case OO_PercentEqual: return BO_RemAssign;
   1790   case OO_CaretEqual: return BO_XorAssign;
   1791   case OO_AmpEqual: return BO_AndAssign;
   1792   case OO_PipeEqual: return BO_OrAssign;
   1793   case OO_LessLess: return BO_Shl;
   1794   case OO_GreaterGreater: return BO_Shr;
   1795   case OO_LessLessEqual: return BO_ShlAssign;
   1796   case OO_GreaterGreaterEqual: return BO_ShrAssign;
   1797   case OO_EqualEqual: return BO_EQ;
   1798   case OO_ExclaimEqual: return BO_NE;
   1799   case OO_LessEqual: return BO_LE;
   1800   case OO_GreaterEqual: return BO_GE;
   1801   case OO_AmpAmp: return BO_LAnd;
   1802   case OO_PipePipe: return BO_LOr;
   1803   case OO_Comma: return BO_Comma;
   1804   case OO_ArrowStar: return BO_PtrMemI;
   1805   }
   1806 }
   1807 
   1808 OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
   1809   static const OverloadedOperatorKind OverOps[] = {
   1810     /* .* Cannot be overloaded */OO_None, OO_ArrowStar,
   1811     OO_Star, OO_Slash, OO_Percent,
   1812     OO_Plus, OO_Minus,
   1813     OO_LessLess, OO_GreaterGreater,
   1814     OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
   1815     OO_EqualEqual, OO_ExclaimEqual,
   1816     OO_Amp,
   1817     OO_Caret,
   1818     OO_Pipe,
   1819     OO_AmpAmp,
   1820     OO_PipePipe,
   1821     OO_Equal, OO_StarEqual,
   1822     OO_SlashEqual, OO_PercentEqual,
   1823     OO_PlusEqual, OO_MinusEqual,
   1824     OO_LessLessEqual, OO_GreaterGreaterEqual,
   1825     OO_AmpEqual, OO_CaretEqual,
   1826     OO_PipeEqual,
   1827     OO_Comma
   1828   };
   1829   return OverOps[Opc];
   1830 }
   1831 
   1832 InitListExpr::InitListExpr(const ASTContext &C, SourceLocation lbraceloc,
   1833                            ArrayRef<Expr*> initExprs, SourceLocation rbraceloc)
   1834   : Expr(InitListExprClass, QualType(), VK_RValue, OK_Ordinary, false, false,
   1835          false, false),
   1836     InitExprs(C, initExprs.size()),
   1837     LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), AltForm(nullptr, true)
   1838 {
   1839   sawArrayRangeDesignator(false);
   1840   for (unsigned I = 0; I != initExprs.size(); ++I) {
   1841     if (initExprs[I]->isTypeDependent())
   1842       ExprBits.TypeDependent = true;
   1843     if (initExprs[I]->isValueDependent())
   1844       ExprBits.ValueDependent = true;
   1845     if (initExprs[I]->isInstantiationDependent())
   1846       ExprBits.InstantiationDependent = true;
   1847     if (initExprs[I]->containsUnexpandedParameterPack())
   1848       ExprBits.ContainsUnexpandedParameterPack = true;
   1849   }
   1850 
   1851   InitExprs.insert(C, InitExprs.end(), initExprs.begin(), initExprs.end());
   1852 }
   1853 
   1854 void InitListExpr::reserveInits(const ASTContext &C, unsigned NumInits) {
   1855   if (NumInits > InitExprs.size())
   1856     InitExprs.reserve(C, NumInits);
   1857 }
   1858 
   1859 void InitListExpr::resizeInits(const ASTContext &C, unsigned NumInits) {
   1860   InitExprs.resize(C, NumInits, nullptr);
   1861 }
   1862 
   1863 Expr *InitListExpr::updateInit(const ASTContext &C, unsigned Init, Expr *expr) {
   1864   if (Init >= InitExprs.size()) {
   1865     InitExprs.insert(C, InitExprs.end(), Init - InitExprs.size() + 1, nullptr);
   1866     setInit(Init, expr);
   1867     return nullptr;
   1868   }
   1869 
   1870   Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
   1871   setInit(Init, expr);
   1872   return Result;
   1873 }
   1874 
   1875 void InitListExpr::setArrayFiller(Expr *filler) {
   1876   assert(!hasArrayFiller() && "Filler already set!");
   1877   ArrayFillerOrUnionFieldInit = filler;
   1878   // Fill out any "holes" in the array due to designated initializers.
   1879   Expr **inits = getInits();
   1880   for (unsigned i = 0, e = getNumInits(); i != e; ++i)
   1881     if (inits[i] == nullptr)
   1882       inits[i] = filler;
   1883 }
   1884 
   1885 bool InitListExpr::isStringLiteralInit() const {
   1886   if (getNumInits() != 1)
   1887     return false;
   1888   const ArrayType *AT = getType()->getAsArrayTypeUnsafe();
   1889   if (!AT || !AT->getElementType()->isIntegerType())
   1890     return false;
   1891   // It is possible for getInit() to return null.
   1892   const Expr *Init = getInit(0);
   1893   if (!Init)
   1894     return false;
   1895   Init = Init->IgnoreParens();
   1896   return isa<StringLiteral>(Init) || isa<ObjCEncodeExpr>(Init);
   1897 }
   1898 
   1899 SourceLocation InitListExpr::getLocStart() const {
   1900   if (InitListExpr *SyntacticForm = getSyntacticForm())
   1901     return SyntacticForm->getLocStart();
   1902   SourceLocation Beg = LBraceLoc;
   1903   if (Beg.isInvalid()) {
   1904     // Find the first non-null initializer.
   1905     for (InitExprsTy::const_iterator I = InitExprs.begin(),
   1906                                      E = InitExprs.end();
   1907       I != E; ++I) {
   1908       if (Stmt *S = *I) {
   1909         Beg = S->getLocStart();
   1910         break;
   1911       }
   1912     }
   1913   }
   1914   return Beg;
   1915 }
   1916 
   1917 SourceLocation InitListExpr::getLocEnd() const {
   1918   if (InitListExpr *SyntacticForm = getSyntacticForm())
   1919     return SyntacticForm->getLocEnd();
   1920   SourceLocation End = RBraceLoc;
   1921   if (End.isInvalid()) {
   1922     // Find the first non-null initializer from the end.
   1923     for (InitExprsTy::const_reverse_iterator I = InitExprs.rbegin(),
   1924          E = InitExprs.rend();
   1925          I != E; ++I) {
   1926       if (Stmt *S = *I) {
   1927         End = S->getLocEnd();
   1928         break;
   1929       }
   1930     }
   1931   }
   1932   return End;
   1933 }
   1934 
   1935 /// getFunctionType - Return the underlying function type for this block.
   1936 ///
   1937 const FunctionProtoType *BlockExpr::getFunctionType() const {
   1938   // The block pointer is never sugared, but the function type might be.
   1939   return cast<BlockPointerType>(getType())
   1940            ->getPointeeType()->castAs<FunctionProtoType>();
   1941 }
   1942 
   1943 SourceLocation BlockExpr::getCaretLocation() const {
   1944   return TheBlock->getCaretLocation();
   1945 }
   1946 const Stmt *BlockExpr::getBody() const {
   1947   return TheBlock->getBody();
   1948 }
   1949 Stmt *BlockExpr::getBody() {
   1950   return TheBlock->getBody();
   1951 }
   1952 
   1953 
   1954 //===----------------------------------------------------------------------===//
   1955 // Generic Expression Routines
   1956 //===----------------------------------------------------------------------===//
   1957 
   1958 /// isUnusedResultAWarning - Return true if this immediate expression should
   1959 /// be warned about if the result is unused.  If so, fill in Loc and Ranges
   1960 /// with location to warn on and the source range[s] to report with the
   1961 /// warning.
   1962 bool Expr::isUnusedResultAWarning(const Expr *&WarnE, SourceLocation &Loc,
   1963                                   SourceRange &R1, SourceRange &R2,
   1964                                   ASTContext &Ctx) const {
   1965   // Don't warn if the expr is type dependent. The type could end up
   1966   // instantiating to void.
   1967   if (isTypeDependent())
   1968     return false;
   1969 
   1970   switch (getStmtClass()) {
   1971   default:
   1972     if (getType()->isVoidType())
   1973       return false;
   1974     WarnE = this;
   1975     Loc = getExprLoc();
   1976     R1 = getSourceRange();
   1977     return true;
   1978   case ParenExprClass:
   1979     return cast<ParenExpr>(this)->getSubExpr()->
   1980       isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   1981   case GenericSelectionExprClass:
   1982     return cast<GenericSelectionExpr>(this)->getResultExpr()->
   1983       isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   1984   case ChooseExprClass:
   1985     return cast<ChooseExpr>(this)->getChosenSubExpr()->
   1986       isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   1987   case UnaryOperatorClass: {
   1988     const UnaryOperator *UO = cast<UnaryOperator>(this);
   1989 
   1990     switch (UO->getOpcode()) {
   1991     case UO_Plus:
   1992     case UO_Minus:
   1993     case UO_AddrOf:
   1994     case UO_Not:
   1995     case UO_LNot:
   1996     case UO_Deref:
   1997       break;
   1998     case UO_PostInc:
   1999     case UO_PostDec:
   2000     case UO_PreInc:
   2001     case UO_PreDec:                 // ++/--
   2002       return false;  // Not a warning.
   2003     case UO_Real:
   2004     case UO_Imag:
   2005       // accessing a piece of a volatile complex is a side-effect.
   2006       if (Ctx.getCanonicalType(UO->getSubExpr()->getType())
   2007           .isVolatileQualified())
   2008         return false;
   2009       break;
   2010     case UO_Extension:
   2011       return UO->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   2012     }
   2013     WarnE = this;
   2014     Loc = UO->getOperatorLoc();
   2015     R1 = UO->getSubExpr()->getSourceRange();
   2016     return true;
   2017   }
   2018   case BinaryOperatorClass: {
   2019     const BinaryOperator *BO = cast<BinaryOperator>(this);
   2020     switch (BO->getOpcode()) {
   2021       default:
   2022         break;
   2023       // Consider the RHS of comma for side effects. LHS was checked by
   2024       // Sema::CheckCommaOperands.
   2025       case BO_Comma:
   2026         // ((foo = <blah>), 0) is an idiom for hiding the result (and
   2027         // lvalue-ness) of an assignment written in a macro.
   2028         if (IntegerLiteral *IE =
   2029               dyn_cast<IntegerLiteral>(BO->getRHS()->IgnoreParens()))
   2030           if (IE->getValue() == 0)
   2031             return false;
   2032         return BO->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   2033       // Consider '||', '&&' to have side effects if the LHS or RHS does.
   2034       case BO_LAnd:
   2035       case BO_LOr:
   2036         if (!BO->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx) ||
   2037             !BO->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx))
   2038           return false;
   2039         break;
   2040     }
   2041     if (BO->isAssignmentOp())
   2042       return false;
   2043     WarnE = this;
   2044     Loc = BO->getOperatorLoc();
   2045     R1 = BO->getLHS()->getSourceRange();
   2046     R2 = BO->getRHS()->getSourceRange();
   2047     return true;
   2048   }
   2049   case CompoundAssignOperatorClass:
   2050   case VAArgExprClass:
   2051   case AtomicExprClass:
   2052     return false;
   2053 
   2054   case ConditionalOperatorClass: {
   2055     // If only one of the LHS or RHS is a warning, the operator might
   2056     // be being used for control flow. Only warn if both the LHS and
   2057     // RHS are warnings.
   2058     const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
   2059     if (!Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx))
   2060       return false;
   2061     if (!Exp->getLHS())
   2062       return true;
   2063     return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   2064   }
   2065 
   2066   case MemberExprClass:
   2067     WarnE = this;
   2068     Loc = cast<MemberExpr>(this)->getMemberLoc();
   2069     R1 = SourceRange(Loc, Loc);
   2070     R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
   2071     return true;
   2072 
   2073   case ArraySubscriptExprClass:
   2074     WarnE = this;
   2075     Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
   2076     R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
   2077     R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
   2078     return true;
   2079 
   2080   case CXXOperatorCallExprClass: {
   2081     // Warn about operator ==,!=,<,>,<=, and >= even when user-defined operator
   2082     // overloads as there is no reasonable way to define these such that they
   2083     // have non-trivial, desirable side-effects. See the -Wunused-comparison
   2084     // warning: operators == and != are commonly typo'ed, and so warning on them
   2085     // provides additional value as well. If this list is updated,
   2086     // DiagnoseUnusedComparison should be as well.
   2087     const CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(this);
   2088     switch (Op->getOperator()) {
   2089     default:
   2090       break;
   2091     case OO_EqualEqual:
   2092     case OO_ExclaimEqual:
   2093     case OO_Less:
   2094     case OO_Greater:
   2095     case OO_GreaterEqual:
   2096     case OO_LessEqual:
   2097       if (Op->getCallReturnType()->isReferenceType() ||
   2098           Op->getCallReturnType()->isVoidType())
   2099         break;
   2100       WarnE = this;
   2101       Loc = Op->getOperatorLoc();
   2102       R1 = Op->getSourceRange();
   2103       return true;
   2104     }
   2105 
   2106     // Fallthrough for generic call handling.
   2107   }
   2108   case CallExprClass:
   2109   case CXXMemberCallExprClass:
   2110   case UserDefinedLiteralClass: {
   2111     // If this is a direct call, get the callee.
   2112     const CallExpr *CE = cast<CallExpr>(this);
   2113     if (const Decl *FD = CE->getCalleeDecl()) {
   2114       // If the callee has attribute pure, const, or warn_unused_result, warn
   2115       // about it. void foo() { strlen("bar"); } should warn.
   2116       //
   2117       // Note: If new cases are added here, DiagnoseUnusedExprResult should be
   2118       // updated to match for QoI.
   2119       if (FD->hasAttr<WarnUnusedResultAttr>() ||
   2120           FD->hasAttr<PureAttr>() || FD->hasAttr<ConstAttr>()) {
   2121         WarnE = this;
   2122         Loc = CE->getCallee()->getLocStart();
   2123         R1 = CE->getCallee()->getSourceRange();
   2124 
   2125         if (unsigned NumArgs = CE->getNumArgs())
   2126           R2 = SourceRange(CE->getArg(0)->getLocStart(),
   2127                            CE->getArg(NumArgs-1)->getLocEnd());
   2128         return true;
   2129       }
   2130     }
   2131     return false;
   2132   }
   2133 
   2134   // If we don't know precisely what we're looking at, let's not warn.
   2135   case UnresolvedLookupExprClass:
   2136   case CXXUnresolvedConstructExprClass:
   2137     return false;
   2138 
   2139   case CXXTemporaryObjectExprClass:
   2140   case CXXConstructExprClass: {
   2141     if (const CXXRecordDecl *Type = getType()->getAsCXXRecordDecl()) {
   2142       if (Type->hasAttr<WarnUnusedAttr>()) {
   2143         WarnE = this;
   2144         Loc = getLocStart();
   2145         R1 = getSourceRange();
   2146         return true;
   2147       }
   2148     }
   2149     return false;
   2150   }
   2151 
   2152   case ObjCMessageExprClass: {
   2153     const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);
   2154     if (Ctx.getLangOpts().ObjCAutoRefCount &&
   2155         ME->isInstanceMessage() &&
   2156         !ME->getType()->isVoidType() &&
   2157         ME->getMethodFamily() == OMF_init) {
   2158       WarnE = this;
   2159       Loc = getExprLoc();
   2160       R1 = ME->getSourceRange();
   2161       return true;
   2162     }
   2163 
   2164     const ObjCMethodDecl *MD = ME->getMethodDecl();
   2165     if (MD && MD->hasAttr<WarnUnusedResultAttr>()) {
   2166       WarnE = this;
   2167       Loc = getExprLoc();
   2168       return true;
   2169     }
   2170     return false;
   2171   }
   2172 
   2173   case ObjCPropertyRefExprClass:
   2174     WarnE = this;
   2175     Loc = getExprLoc();
   2176     R1 = getSourceRange();
   2177     return true;
   2178 
   2179   case PseudoObjectExprClass: {
   2180     const PseudoObjectExpr *PO = cast<PseudoObjectExpr>(this);
   2181 
   2182     // Only complain about things that have the form of a getter.
   2183     if (isa<UnaryOperator>(PO->getSyntacticForm()) ||
   2184         isa<BinaryOperator>(PO->getSyntacticForm()))
   2185       return false;
   2186 
   2187     WarnE = this;
   2188     Loc = getExprLoc();
   2189     R1 = getSourceRange();
   2190     return true;
   2191   }
   2192 
   2193   case StmtExprClass: {
   2194     // Statement exprs don't logically have side effects themselves, but are
   2195     // sometimes used in macros in ways that give them a type that is unused.
   2196     // For example ({ blah; foo(); }) will end up with a type if foo has a type.
   2197     // however, if the result of the stmt expr is dead, we don't want to emit a
   2198     // warning.
   2199     const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
   2200     if (!CS->body_empty()) {
   2201       if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
   2202         return E->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   2203       if (const LabelStmt *Label = dyn_cast<LabelStmt>(CS->body_back()))
   2204         if (const Expr *E = dyn_cast<Expr>(Label->getSubStmt()))
   2205           return E->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   2206     }
   2207 
   2208     if (getType()->isVoidType())
   2209       return false;
   2210     WarnE = this;
   2211     Loc = cast<StmtExpr>(this)->getLParenLoc();
   2212     R1 = getSourceRange();
   2213     return true;
   2214   }
   2215   case CXXFunctionalCastExprClass:
   2216   case CStyleCastExprClass: {
   2217     // Ignore an explicit cast to void unless the operand is a non-trivial
   2218     // volatile lvalue.
   2219     const CastExpr *CE = cast<CastExpr>(this);
   2220     if (CE->getCastKind() == CK_ToVoid) {
   2221       if (CE->getSubExpr()->isGLValue() &&
   2222           CE->getSubExpr()->getType().isVolatileQualified()) {
   2223         const DeclRefExpr *DRE =
   2224             dyn_cast<DeclRefExpr>(CE->getSubExpr()->IgnoreParens());
   2225         if (!(DRE && isa<VarDecl>(DRE->getDecl()) &&
   2226               cast<VarDecl>(DRE->getDecl())->hasLocalStorage())) {
   2227           return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc,
   2228                                                           R1, R2, Ctx);
   2229         }
   2230       }
   2231       return false;
   2232     }
   2233 
   2234     // If this is a cast to a constructor conversion, check the operand.
   2235     // Otherwise, the result of the cast is unused.
   2236     if (CE->getCastKind() == CK_ConstructorConversion)
   2237       return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   2238 
   2239     WarnE = this;
   2240     if (const CXXFunctionalCastExpr *CXXCE =
   2241             dyn_cast<CXXFunctionalCastExpr>(this)) {
   2242       Loc = CXXCE->getLocStart();
   2243       R1 = CXXCE->getSubExpr()->getSourceRange();
   2244     } else {
   2245       const CStyleCastExpr *CStyleCE = cast<CStyleCastExpr>(this);
   2246       Loc = CStyleCE->getLParenLoc();
   2247       R1 = CStyleCE->getSubExpr()->getSourceRange();
   2248     }
   2249     return true;
   2250   }
   2251   case ImplicitCastExprClass: {
   2252     const CastExpr *ICE = cast<ImplicitCastExpr>(this);
   2253 
   2254     // lvalue-to-rvalue conversion on a volatile lvalue is a side-effect.
   2255     if (ICE->getCastKind() == CK_LValueToRValue &&
   2256         ICE->getSubExpr()->getType().isVolatileQualified())
   2257       return false;
   2258 
   2259     return ICE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   2260   }
   2261   case CXXDefaultArgExprClass:
   2262     return (cast<CXXDefaultArgExpr>(this)
   2263             ->getExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
   2264   case CXXDefaultInitExprClass:
   2265     return (cast<CXXDefaultInitExpr>(this)
   2266             ->getExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
   2267 
   2268   case CXXNewExprClass:
   2269     // FIXME: In theory, there might be new expressions that don't have side
   2270     // effects (e.g. a placement new with an uninitialized POD).
   2271   case CXXDeleteExprClass:
   2272     return false;
   2273   case CXXBindTemporaryExprClass:
   2274     return (cast<CXXBindTemporaryExpr>(this)
   2275             ->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
   2276   case ExprWithCleanupsClass:
   2277     return (cast<ExprWithCleanups>(this)
   2278             ->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
   2279   }
   2280 }
   2281 
   2282 /// isOBJCGCCandidate - Check if an expression is objc gc'able.
   2283 /// returns true, if it is; false otherwise.
   2284 bool Expr::isOBJCGCCandidate(ASTContext &Ctx) const {
   2285   const Expr *E = IgnoreParens();
   2286   switch (E->getStmtClass()) {
   2287   default:
   2288     return false;
   2289   case ObjCIvarRefExprClass:
   2290     return true;
   2291   case Expr::UnaryOperatorClass:
   2292     return cast<UnaryOperator>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
   2293   case ImplicitCastExprClass:
   2294     return cast<ImplicitCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
   2295   case MaterializeTemporaryExprClass:
   2296     return cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr()
   2297                                                       ->isOBJCGCCandidate(Ctx);
   2298   case CStyleCastExprClass:
   2299     return cast<CStyleCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
   2300   case DeclRefExprClass: {
   2301     const Decl *D = cast<DeclRefExpr>(E)->getDecl();
   2302 
   2303     if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
   2304       if (VD->hasGlobalStorage())
   2305         return true;
   2306       QualType T = VD->getType();
   2307       // dereferencing to a  pointer is always a gc'able candidate,
   2308       // unless it is __weak.
   2309       return T->isPointerType() &&
   2310              (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
   2311     }
   2312     return false;
   2313   }
   2314   case MemberExprClass: {
   2315     const MemberExpr *M = cast<MemberExpr>(E);
   2316     return M->getBase()->isOBJCGCCandidate(Ctx);
   2317   }
   2318   case ArraySubscriptExprClass:
   2319     return cast<ArraySubscriptExpr>(E)->getBase()->isOBJCGCCandidate(Ctx);
   2320   }
   2321 }
   2322 
   2323 bool Expr::isBoundMemberFunction(ASTContext &Ctx) const {
   2324   if (isTypeDependent())
   2325     return false;
   2326   return ClassifyLValue(Ctx) == Expr::LV_MemberFunction;
   2327 }
   2328 
   2329 QualType Expr::findBoundMemberType(const Expr *expr) {
   2330   assert(expr->hasPlaceholderType(BuiltinType::BoundMember));
   2331 
   2332   // Bound member expressions are always one of these possibilities:
   2333   //   x->m      x.m      x->*y      x.*y
   2334   // (possibly parenthesized)
   2335 
   2336   expr = expr->IgnoreParens();
   2337   if (const MemberExpr *mem = dyn_cast<MemberExpr>(expr)) {
   2338     assert(isa<CXXMethodDecl>(mem->getMemberDecl()));
   2339     return mem->getMemberDecl()->getType();
   2340   }
   2341 
   2342   if (const BinaryOperator *op = dyn_cast<BinaryOperator>(expr)) {
   2343     QualType type = op->getRHS()->getType()->castAs<MemberPointerType>()
   2344                       ->getPointeeType();
   2345     assert(type->isFunctionType());
   2346     return type;
   2347   }
   2348 
   2349   assert(isa<UnresolvedMemberExpr>(expr));
   2350   return QualType();
   2351 }
   2352 
   2353 Expr* Expr::IgnoreParens() {
   2354   Expr* E = this;
   2355   while (true) {
   2356     if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
   2357       E = P->getSubExpr();
   2358       continue;
   2359     }
   2360     if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
   2361       if (P->getOpcode() == UO_Extension) {
   2362         E = P->getSubExpr();
   2363         continue;
   2364       }
   2365     }
   2366     if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
   2367       if (!P->isResultDependent()) {
   2368         E = P->getResultExpr();
   2369         continue;
   2370       }
   2371     }
   2372     if (ChooseExpr* P = dyn_cast<ChooseExpr>(E)) {
   2373       if (!P->isConditionDependent()) {
   2374         E = P->getChosenSubExpr();
   2375         continue;
   2376       }
   2377     }
   2378     return E;
   2379   }
   2380 }
   2381 
   2382 /// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
   2383 /// or CastExprs or ImplicitCastExprs, returning their operand.
   2384 Expr *Expr::IgnoreParenCasts() {
   2385   Expr *E = this;
   2386   while (true) {
   2387     E = E->IgnoreParens();
   2388     if (CastExpr *P = dyn_cast<CastExpr>(E)) {
   2389       E = P->getSubExpr();
   2390       continue;
   2391     }
   2392     if (MaterializeTemporaryExpr *Materialize
   2393                                       = dyn_cast<MaterializeTemporaryExpr>(E)) {
   2394       E = Materialize->GetTemporaryExpr();
   2395       continue;
   2396     }
   2397     if (SubstNonTypeTemplateParmExpr *NTTP
   2398                                   = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
   2399       E = NTTP->getReplacement();
   2400       continue;
   2401     }
   2402     return E;
   2403   }
   2404 }
   2405 
   2406 Expr *Expr::IgnoreCasts() {
   2407   Expr *E = this;
   2408   while (true) {
   2409     if (CastExpr *P = dyn_cast<CastExpr>(E)) {
   2410       E = P->getSubExpr();
   2411       continue;
   2412     }
   2413     if (MaterializeTemporaryExpr *Materialize
   2414         = dyn_cast<MaterializeTemporaryExpr>(E)) {
   2415       E = Materialize->GetTemporaryExpr();
   2416       continue;
   2417     }
   2418     if (SubstNonTypeTemplateParmExpr *NTTP
   2419         = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
   2420       E = NTTP->getReplacement();
   2421       continue;
   2422     }
   2423     return E;
   2424   }
   2425 }
   2426 
   2427 /// IgnoreParenLValueCasts - Ignore parentheses and lvalue-to-rvalue
   2428 /// casts.  This is intended purely as a temporary workaround for code
   2429 /// that hasn't yet been rewritten to do the right thing about those
   2430 /// casts, and may disappear along with the last internal use.
   2431 Expr *Expr::IgnoreParenLValueCasts() {
   2432   Expr *E = this;
   2433   while (true) {
   2434     E = E->IgnoreParens();
   2435     if (CastExpr *P = dyn_cast<CastExpr>(E)) {
   2436       if (P->getCastKind() == CK_LValueToRValue) {
   2437         E = P->getSubExpr();
   2438         continue;
   2439       }
   2440     } else if (MaterializeTemporaryExpr *Materialize
   2441                                       = dyn_cast<MaterializeTemporaryExpr>(E)) {
   2442       E = Materialize->GetTemporaryExpr();
   2443       continue;
   2444     } else if (SubstNonTypeTemplateParmExpr *NTTP
   2445                                   = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
   2446       E = NTTP->getReplacement();
   2447       continue;
   2448     }
   2449     break;
   2450   }
   2451   return E;
   2452 }
   2453 
   2454 Expr *Expr::ignoreParenBaseCasts() {
   2455   Expr *E = this;
   2456   while (true) {
   2457     E = E->IgnoreParens();
   2458     if (CastExpr *CE = dyn_cast<CastExpr>(E)) {
   2459       if (CE->getCastKind() == CK_DerivedToBase ||
   2460           CE->getCastKind() == CK_UncheckedDerivedToBase ||
   2461           CE->getCastKind() == CK_NoOp) {
   2462         E = CE->getSubExpr();
   2463         continue;
   2464       }
   2465     }
   2466 
   2467     return E;
   2468   }
   2469 }
   2470 
   2471 Expr *Expr::IgnoreParenImpCasts() {
   2472   Expr *E = this;
   2473   while (true) {
   2474     E = E->IgnoreParens();
   2475     if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E)) {
   2476       E = P->getSubExpr();
   2477       continue;
   2478     }
   2479     if (MaterializeTemporaryExpr *Materialize
   2480                                       = dyn_cast<MaterializeTemporaryExpr>(E)) {
   2481       E = Materialize->GetTemporaryExpr();
   2482       continue;
   2483     }
   2484     if (SubstNonTypeTemplateParmExpr *NTTP
   2485                                   = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
   2486       E = NTTP->getReplacement();
   2487       continue;
   2488     }
   2489     return E;
   2490   }
   2491 }
   2492 
   2493 Expr *Expr::IgnoreConversionOperator() {
   2494   if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
   2495     if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
   2496       return MCE->getImplicitObjectArgument();
   2497   }
   2498   return this;
   2499 }
   2500 
   2501 /// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
   2502 /// value (including ptr->int casts of the same size).  Strip off any
   2503 /// ParenExpr or CastExprs, returning their operand.
   2504 Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
   2505   Expr *E = this;
   2506   while (true) {
   2507     E = E->IgnoreParens();
   2508 
   2509     if (CastExpr *P = dyn_cast<CastExpr>(E)) {
   2510       // We ignore integer <-> casts that are of the same width, ptr<->ptr and
   2511       // ptr<->int casts of the same width.  We also ignore all identity casts.
   2512       Expr *SE = P->getSubExpr();
   2513 
   2514       if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
   2515         E = SE;
   2516         continue;
   2517       }
   2518 
   2519       if ((E->getType()->isPointerType() ||
   2520            E->getType()->isIntegralType(Ctx)) &&
   2521           (SE->getType()->isPointerType() ||
   2522            SE->getType()->isIntegralType(Ctx)) &&
   2523           Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
   2524         E = SE;
   2525         continue;
   2526       }
   2527     }
   2528 
   2529     if (SubstNonTypeTemplateParmExpr *NTTP
   2530                                   = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
   2531       E = NTTP->getReplacement();
   2532       continue;
   2533     }
   2534 
   2535     return E;
   2536   }
   2537 }
   2538 
   2539 bool Expr::isDefaultArgument() const {
   2540   const Expr *E = this;
   2541   if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
   2542     E = M->GetTemporaryExpr();
   2543 
   2544   while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
   2545     E = ICE->getSubExprAsWritten();
   2546 
   2547   return isa<CXXDefaultArgExpr>(E);
   2548 }
   2549 
   2550 /// \brief Skip over any no-op casts and any temporary-binding
   2551 /// expressions.
   2552 static const Expr *skipTemporaryBindingsNoOpCastsAndParens(const Expr *E) {
   2553   if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
   2554     E = M->GetTemporaryExpr();
   2555 
   2556   while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
   2557     if (ICE->getCastKind() == CK_NoOp)
   2558       E = ICE->getSubExpr();
   2559     else
   2560       break;
   2561   }
   2562 
   2563   while (const CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
   2564     E = BE->getSubExpr();
   2565 
   2566   while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
   2567     if (ICE->getCastKind() == CK_NoOp)
   2568       E = ICE->getSubExpr();
   2569     else
   2570       break;
   2571   }
   2572 
   2573   return E->IgnoreParens();
   2574 }
   2575 
   2576 /// isTemporaryObject - Determines if this expression produces a
   2577 /// temporary of the given class type.
   2578 bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
   2579   if (!C.hasSameUnqualifiedType(getType(), C.getTypeDeclType(TempTy)))
   2580     return false;
   2581 
   2582   const Expr *E = skipTemporaryBindingsNoOpCastsAndParens(this);
   2583 
   2584   // Temporaries are by definition pr-values of class type.
   2585   if (!E->Classify(C).isPRValue()) {
   2586     // In this context, property reference is a message call and is pr-value.
   2587     if (!isa<ObjCPropertyRefExpr>(E))
   2588       return false;
   2589   }
   2590 
   2591   // Black-list a few cases which yield pr-values of class type that don't
   2592   // refer to temporaries of that type:
   2593 
   2594   // - implicit derived-to-base conversions
   2595   if (isa<ImplicitCastExpr>(E)) {
   2596     switch (cast<ImplicitCastExpr>(E)->getCastKind()) {
   2597     case CK_DerivedToBase:
   2598     case CK_UncheckedDerivedToBase:
   2599       return false;
   2600     default:
   2601       break;
   2602     }
   2603   }
   2604 
   2605   // - member expressions (all)
   2606   if (isa<MemberExpr>(E))
   2607     return false;
   2608 
   2609   if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E))
   2610     if (BO->isPtrMemOp())
   2611       return false;
   2612 
   2613   // - opaque values (all)
   2614   if (isa<OpaqueValueExpr>(E))
   2615     return false;
   2616 
   2617   return true;
   2618 }
   2619 
   2620 bool Expr::isImplicitCXXThis() const {
   2621   const Expr *E = this;
   2622 
   2623   // Strip away parentheses and casts we don't care about.
   2624   while (true) {
   2625     if (const ParenExpr *Paren = dyn_cast<ParenExpr>(E)) {
   2626       E = Paren->getSubExpr();
   2627       continue;
   2628     }
   2629 
   2630     if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
   2631       if (ICE->getCastKind() == CK_NoOp ||
   2632           ICE->getCastKind() == CK_LValueToRValue ||
   2633           ICE->getCastKind() == CK_DerivedToBase ||
   2634           ICE->getCastKind() == CK_UncheckedDerivedToBase) {
   2635         E = ICE->getSubExpr();
   2636         continue;
   2637       }
   2638     }
   2639 
   2640     if (const UnaryOperator* UnOp = dyn_cast<UnaryOperator>(E)) {
   2641       if (UnOp->getOpcode() == UO_Extension) {
   2642         E = UnOp->getSubExpr();
   2643         continue;
   2644       }
   2645     }
   2646 
   2647     if (const MaterializeTemporaryExpr *M
   2648                                       = dyn_cast<MaterializeTemporaryExpr>(E)) {
   2649       E = M->GetTemporaryExpr();
   2650       continue;
   2651     }
   2652 
   2653     break;
   2654   }
   2655 
   2656   if (const CXXThisExpr *This = dyn_cast<CXXThisExpr>(E))
   2657     return This->isImplicit();
   2658 
   2659   return false;
   2660 }
   2661 
   2662 /// hasAnyTypeDependentArguments - Determines if any of the expressions
   2663 /// in Exprs is type-dependent.
   2664 bool Expr::hasAnyTypeDependentArguments(ArrayRef<Expr *> Exprs) {
   2665   for (unsigned I = 0; I < Exprs.size(); ++I)
   2666     if (Exprs[I]->isTypeDependent())
   2667       return true;
   2668 
   2669   return false;
   2670 }
   2671 
   2672 bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef,
   2673                                  const Expr **Culprit) const {
   2674   // This function is attempting whether an expression is an initializer
   2675   // which can be evaluated at compile-time. It very closely parallels
   2676   // ConstExprEmitter in CGExprConstant.cpp; if they don't match, it
   2677   // will lead to unexpected results.  Like ConstExprEmitter, it falls back
   2678   // to isEvaluatable most of the time.
   2679   //
   2680   // If we ever capture reference-binding directly in the AST, we can
   2681   // kill the second parameter.
   2682 
   2683   if (IsForRef) {
   2684     EvalResult Result;
   2685     if (EvaluateAsLValue(Result, Ctx) && !Result.HasSideEffects)
   2686       return true;
   2687     if (Culprit)
   2688       *Culprit = this;
   2689     return false;
   2690   }
   2691 
   2692   switch (getStmtClass()) {
   2693   default: break;
   2694   case StringLiteralClass:
   2695   case ObjCEncodeExprClass:
   2696     return true;
   2697   case CXXTemporaryObjectExprClass:
   2698   case CXXConstructExprClass: {
   2699     const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
   2700 
   2701     if (CE->getConstructor()->isTrivial() &&
   2702         CE->getConstructor()->getParent()->hasTrivialDestructor()) {
   2703       // Trivial default constructor
   2704       if (!CE->getNumArgs()) return true;
   2705 
   2706       // Trivial copy constructor
   2707       assert(CE->getNumArgs() == 1 && "trivial ctor with > 1 argument");
   2708       return CE->getArg(0)->isConstantInitializer(Ctx, false, Culprit);
   2709     }
   2710 
   2711     break;
   2712   }
   2713   case CompoundLiteralExprClass: {
   2714     // This handles gcc's extension that allows global initializers like
   2715     // "struct x {int x;} x = (struct x) {};".
   2716     // FIXME: This accepts other cases it shouldn't!
   2717     const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
   2718     return Exp->isConstantInitializer(Ctx, false, Culprit);
   2719   }
   2720   case InitListExprClass: {
   2721     const InitListExpr *ILE = cast<InitListExpr>(this);
   2722     if (ILE->getType()->isArrayType()) {
   2723       unsigned numInits = ILE->getNumInits();
   2724       for (unsigned i = 0; i < numInits; i++) {
   2725         if (!ILE->getInit(i)->isConstantInitializer(Ctx, false, Culprit))
   2726           return false;
   2727       }
   2728       return true;
   2729     }
   2730 
   2731     if (ILE->getType()->isRecordType()) {
   2732       unsigned ElementNo = 0;
   2733       RecordDecl *RD = ILE->getType()->getAs<RecordType>()->getDecl();
   2734       for (RecordDecl::field_iterator Field = RD->field_begin(),
   2735            FieldEnd = RD->field_end(); Field != FieldEnd; ++Field) {
   2736         // If this is a union, skip all the fields that aren't being initialized.
   2737         if (RD->isUnion() && ILE->getInitializedFieldInUnion() != *Field)
   2738           continue;
   2739 
   2740         // Don't emit anonymous bitfields, they just affect layout.
   2741         if (Field->isUnnamedBitfield())
   2742           continue;
   2743 
   2744         if (ElementNo < ILE->getNumInits()) {
   2745           const Expr *Elt = ILE->getInit(ElementNo++);
   2746           if (Field->isBitField()) {
   2747             // Bitfields have to evaluate to an integer.
   2748             llvm::APSInt ResultTmp;
   2749             if (!Elt->EvaluateAsInt(ResultTmp, Ctx)) {
   2750               if (Culprit)
   2751                 *Culprit = Elt;
   2752               return false;
   2753             }
   2754           } else {
   2755             bool RefType = Field->getType()->isReferenceType();
   2756             if (!Elt->isConstantInitializer(Ctx, RefType, Culprit))
   2757               return false;
   2758           }
   2759         }
   2760       }
   2761       return true;
   2762     }
   2763 
   2764     break;
   2765   }
   2766   case ImplicitValueInitExprClass:
   2767     return true;
   2768   case ParenExprClass:
   2769     return cast<ParenExpr>(this)->getSubExpr()
   2770       ->isConstantInitializer(Ctx, IsForRef, Culprit);
   2771   case GenericSelectionExprClass:
   2772     return cast<GenericSelectionExpr>(this)->getResultExpr()
   2773       ->isConstantInitializer(Ctx, IsForRef, Culprit);
   2774   case ChooseExprClass:
   2775     if (cast<ChooseExpr>(this)->isConditionDependent()) {
   2776       if (Culprit)
   2777         *Culprit = this;
   2778       return false;
   2779     }
   2780     return cast<ChooseExpr>(this)->getChosenSubExpr()
   2781       ->isConstantInitializer(Ctx, IsForRef, Culprit);
   2782   case UnaryOperatorClass: {
   2783     const UnaryOperator* Exp = cast<UnaryOperator>(this);
   2784     if (Exp->getOpcode() == UO_Extension)
   2785       return Exp->getSubExpr()->isConstantInitializer(Ctx, false, Culprit);
   2786     break;
   2787   }
   2788   case CXXFunctionalCastExprClass:
   2789   case CXXStaticCastExprClass:
   2790   case ImplicitCastExprClass:
   2791   case CStyleCastExprClass:
   2792   case ObjCBridgedCastExprClass:
   2793   case CXXDynamicCastExprClass:
   2794   case CXXReinterpretCastExprClass:
   2795   case CXXConstCastExprClass: {
   2796     const CastExpr *CE = cast<CastExpr>(this);
   2797 
   2798     // Handle misc casts we want to ignore.
   2799     if (CE->getCastKind() == CK_NoOp ||
   2800         CE->getCastKind() == CK_LValueToRValue ||
   2801         CE->getCastKind() == CK_ToUnion ||
   2802         CE->getCastKind() == CK_ConstructorConversion ||
   2803         CE->getCastKind() == CK_NonAtomicToAtomic ||
   2804         CE->getCastKind() == CK_AtomicToNonAtomic)
   2805       return CE->getSubExpr()->isConstantInitializer(Ctx, false, Culprit);
   2806 
   2807     break;
   2808   }
   2809   case MaterializeTemporaryExprClass:
   2810     return cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
   2811       ->isConstantInitializer(Ctx, false, Culprit);
   2812 
   2813   case SubstNonTypeTemplateParmExprClass:
   2814     return cast<SubstNonTypeTemplateParmExpr>(this)->getReplacement()
   2815       ->isConstantInitializer(Ctx, false, Culprit);
   2816   case CXXDefaultArgExprClass:
   2817     return cast<CXXDefaultArgExpr>(this)->getExpr()
   2818       ->isConstantInitializer(Ctx, false, Culprit);
   2819   case CXXDefaultInitExprClass:
   2820     return cast<CXXDefaultInitExpr>(this)->getExpr()
   2821       ->isConstantInitializer(Ctx, false, Culprit);
   2822   }
   2823   if (isEvaluatable(Ctx))
   2824     return true;
   2825   if (Culprit)
   2826     *Culprit = this;
   2827   return false;
   2828 }
   2829 
   2830 bool Expr::HasSideEffects(const ASTContext &Ctx) const {
   2831   if (isInstantiationDependent())
   2832     return true;
   2833 
   2834   switch (getStmtClass()) {
   2835   case NoStmtClass:
   2836   #define ABSTRACT_STMT(Type)
   2837   #define STMT(Type, Base) case Type##Class:
   2838   #define EXPR(Type, Base)
   2839   #include "clang/AST/StmtNodes.inc"
   2840     llvm_unreachable("unexpected Expr kind");
   2841 
   2842   case DependentScopeDeclRefExprClass:
   2843   case CXXUnresolvedConstructExprClass:
   2844   case CXXDependentScopeMemberExprClass:
   2845   case UnresolvedLookupExprClass:
   2846   case UnresolvedMemberExprClass:
   2847   case PackExpansionExprClass:
   2848   case SubstNonTypeTemplateParmPackExprClass:
   2849   case FunctionParmPackExprClass:
   2850     llvm_unreachable("shouldn't see dependent / unresolved nodes here");
   2851 
   2852   case DeclRefExprClass:
   2853   case ObjCIvarRefExprClass:
   2854   case PredefinedExprClass:
   2855   case IntegerLiteralClass:
   2856   case FloatingLiteralClass:
   2857   case ImaginaryLiteralClass:
   2858   case StringLiteralClass:
   2859   case CharacterLiteralClass:
   2860   case OffsetOfExprClass:
   2861   case ImplicitValueInitExprClass:
   2862   case UnaryExprOrTypeTraitExprClass:
   2863   case AddrLabelExprClass:
   2864   case GNUNullExprClass:
   2865   case CXXBoolLiteralExprClass:
   2866   case CXXNullPtrLiteralExprClass:
   2867   case CXXThisExprClass:
   2868   case CXXScalarValueInitExprClass:
   2869   case TypeTraitExprClass:
   2870   case ArrayTypeTraitExprClass:
   2871   case ExpressionTraitExprClass:
   2872   case CXXNoexceptExprClass:
   2873   case SizeOfPackExprClass:
   2874   case ObjCStringLiteralClass:
   2875   case ObjCEncodeExprClass:
   2876   case ObjCBoolLiteralExprClass:
   2877   case CXXUuidofExprClass:
   2878   case OpaqueValueExprClass:
   2879     // These never have a side-effect.
   2880     return false;
   2881 
   2882   case CallExprClass:
   2883   case MSPropertyRefExprClass:
   2884   case CompoundAssignOperatorClass:
   2885   case VAArgExprClass:
   2886   case AtomicExprClass:
   2887   case StmtExprClass:
   2888   case CXXOperatorCallExprClass:
   2889   case CXXMemberCallExprClass:
   2890   case UserDefinedLiteralClass:
   2891   case CXXThrowExprClass:
   2892   case CXXNewExprClass:
   2893   case CXXDeleteExprClass:
   2894   case ExprWithCleanupsClass:
   2895   case CXXBindTemporaryExprClass:
   2896   case BlockExprClass:
   2897   case CUDAKernelCallExprClass:
   2898     // These always have a side-effect.
   2899     return true;
   2900 
   2901   case ParenExprClass:
   2902   case ArraySubscriptExprClass:
   2903   case MemberExprClass:
   2904   case ConditionalOperatorClass:
   2905   case BinaryConditionalOperatorClass:
   2906   case CompoundLiteralExprClass:
   2907   case ExtVectorElementExprClass:
   2908   case DesignatedInitExprClass:
   2909   case ParenListExprClass:
   2910   case CXXPseudoDestructorExprClass:
   2911   case CXXStdInitializerListExprClass:
   2912   case SubstNonTypeTemplateParmExprClass:
   2913   case MaterializeTemporaryExprClass:
   2914   case ShuffleVectorExprClass:
   2915   case ConvertVectorExprClass:
   2916   case AsTypeExprClass:
   2917     // These have a side-effect if any subexpression does.
   2918     break;
   2919 
   2920   case UnaryOperatorClass:
   2921     if (cast<UnaryOperator>(this)->isIncrementDecrementOp())
   2922       return true;
   2923     break;
   2924 
   2925   case BinaryOperatorClass:
   2926     if (cast<BinaryOperator>(this)->isAssignmentOp())
   2927       return true;
   2928     break;
   2929 
   2930   case InitListExprClass:
   2931     // FIXME: The children for an InitListExpr doesn't include the array filler.
   2932     if (const Expr *E = cast<InitListExpr>(this)->getArrayFiller())
   2933       if (E->HasSideEffects(Ctx))
   2934         return true;
   2935     break;
   2936 
   2937   case GenericSelectionExprClass:
   2938     return cast<GenericSelectionExpr>(this)->getResultExpr()->
   2939         HasSideEffects(Ctx);
   2940 
   2941   case ChooseExprClass:
   2942     return cast<ChooseExpr>(this)->getChosenSubExpr()->HasSideEffects(Ctx);
   2943 
   2944   case CXXDefaultArgExprClass:
   2945     return cast<CXXDefaultArgExpr>(this)->getExpr()->HasSideEffects(Ctx);
   2946 
   2947   case CXXDefaultInitExprClass:
   2948     if (const Expr *E = cast<CXXDefaultInitExpr>(this)->getExpr())
   2949       return E->HasSideEffects(Ctx);
   2950     // If we've not yet parsed the initializer, assume it has side-effects.
   2951     return true;
   2952 
   2953   case CXXDynamicCastExprClass: {
   2954     // A dynamic_cast expression has side-effects if it can throw.
   2955     const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(this);
   2956     if (DCE->getTypeAsWritten()->isReferenceType() &&
   2957         DCE->getCastKind() == CK_Dynamic)
   2958       return true;
   2959   } // Fall through.
   2960   case ImplicitCastExprClass:
   2961   case CStyleCastExprClass:
   2962   case CXXStaticCastExprClass:
   2963   case CXXReinterpretCastExprClass:
   2964   case CXXConstCastExprClass:
   2965   case CXXFunctionalCastExprClass: {
   2966     const CastExpr *CE = cast<CastExpr>(this);
   2967     if (CE->getCastKind() == CK_LValueToRValue &&
   2968         CE->getSubExpr()->getType().isVolatileQualified())
   2969       return true;
   2970     break;
   2971   }
   2972 
   2973   case CXXTypeidExprClass:
   2974     // typeid might throw if its subexpression is potentially-evaluated, so has
   2975     // side-effects in that case whether or not its subexpression does.
   2976     return cast<CXXTypeidExpr>(this)->isPotentiallyEvaluated();
   2977 
   2978   case CXXConstructExprClass:
   2979   case CXXTemporaryObjectExprClass: {
   2980     const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
   2981     if (!CE->getConstructor()->isTrivial())
   2982       return true;
   2983     // A trivial constructor does not add any side-effects of its own. Just look
   2984     // at its arguments.
   2985     break;
   2986   }
   2987 
   2988   case LambdaExprClass: {
   2989     const LambdaExpr *LE = cast<LambdaExpr>(this);
   2990     for (LambdaExpr::capture_iterator I = LE->capture_begin(),
   2991                                       E = LE->capture_end(); I != E; ++I)
   2992       if (I->getCaptureKind() == LCK_ByCopy)
   2993         // FIXME: Only has a side-effect if the variable is volatile or if
   2994         // the copy would invoke a non-trivial copy constructor.
   2995         return true;
   2996     return false;
   2997   }
   2998 
   2999   case PseudoObjectExprClass: {
   3000     // Only look for side-effects in the semantic form, and look past
   3001     // OpaqueValueExpr bindings in that form.
   3002     const PseudoObjectExpr *PO = cast<PseudoObjectExpr>(this);
   3003     for (PseudoObjectExpr::const_semantics_iterator I = PO->semantics_begin(),
   3004                                                     E = PO->semantics_end();
   3005          I != E; ++I) {
   3006       const Expr *Subexpr = *I;
   3007       if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Subexpr))
   3008         Subexpr = OVE->getSourceExpr();
   3009       if (Subexpr->HasSideEffects(Ctx))
   3010         return true;
   3011     }
   3012     return false;
   3013   }
   3014 
   3015   case ObjCBoxedExprClass:
   3016   case ObjCArrayLiteralClass:
   3017   case ObjCDictionaryLiteralClass:
   3018   case ObjCMessageExprClass:
   3019   case ObjCSelectorExprClass:
   3020   case ObjCProtocolExprClass:
   3021   case ObjCPropertyRefExprClass:
   3022   case ObjCIsaExprClass:
   3023   case ObjCIndirectCopyRestoreExprClass:
   3024   case ObjCSubscriptRefExprClass:
   3025   case ObjCBridgedCastExprClass:
   3026     // FIXME: Classify these cases better.
   3027     return true;
   3028   }
   3029 
   3030   // Recurse to children.
   3031   for (const_child_range SubStmts = children(); SubStmts; ++SubStmts)
   3032     if (const Stmt *S = *SubStmts)
   3033       if (cast<Expr>(S)->HasSideEffects(Ctx))
   3034         return true;
   3035 
   3036   return false;
   3037 }
   3038 
   3039 namespace {
   3040   /// \brief Look for a call to a non-trivial function within an expression.
   3041   class NonTrivialCallFinder : public EvaluatedExprVisitor<NonTrivialCallFinder>
   3042   {
   3043     typedef EvaluatedExprVisitor<NonTrivialCallFinder> Inherited;
   3044 
   3045     bool NonTrivial;
   3046 
   3047   public:
   3048     explicit NonTrivialCallFinder(ASTContext &Context)
   3049       : Inherited(Context), NonTrivial(false) { }
   3050 
   3051     bool hasNonTrivialCall() const { return NonTrivial; }
   3052 
   3053     void VisitCallExpr(CallExpr *E) {
   3054       if (CXXMethodDecl *Method
   3055           = dyn_cast_or_null<CXXMethodDecl>(E->getCalleeDecl())) {
   3056         if (Method->isTrivial()) {
   3057           // Recurse to children of the call.
   3058           Inherited::VisitStmt(E);
   3059           return;
   3060         }
   3061       }
   3062 
   3063       NonTrivial = true;
   3064     }
   3065 
   3066     void VisitCXXConstructExpr(CXXConstructExpr *E) {
   3067       if (E->getConstructor()->isTrivial()) {
   3068         // Recurse to children of the call.
   3069         Inherited::VisitStmt(E);
   3070         return;
   3071       }
   3072 
   3073       NonTrivial = true;
   3074     }
   3075 
   3076     void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
   3077       if (E->getTemporary()->getDestructor()->isTrivial()) {
   3078         Inherited::VisitStmt(E);
   3079         return;
   3080       }
   3081 
   3082       NonTrivial = true;
   3083     }
   3084   };
   3085 }
   3086 
   3087 bool Expr::hasNonTrivialCall(ASTContext &Ctx) {
   3088   NonTrivialCallFinder Finder(Ctx);
   3089   Finder.Visit(this);
   3090   return Finder.hasNonTrivialCall();
   3091 }
   3092 
   3093 /// isNullPointerConstant - C99 6.3.2.3p3 - Return whether this is a null
   3094 /// pointer constant or not, as well as the specific kind of constant detected.
   3095 /// Null pointer constants can be integer constant expressions with the
   3096 /// value zero, casts of zero to void*, nullptr (C++0X), or __null
   3097 /// (a GNU extension).
   3098 Expr::NullPointerConstantKind
   3099 Expr::isNullPointerConstant(ASTContext &Ctx,
   3100                             NullPointerConstantValueDependence NPC) const {
   3101   if (isValueDependent() &&
   3102       (!Ctx.getLangOpts().CPlusPlus11 || Ctx.getLangOpts().MSVCCompat)) {
   3103     switch (NPC) {
   3104     case NPC_NeverValueDependent:
   3105       llvm_unreachable("Unexpected value dependent expression!");
   3106     case NPC_ValueDependentIsNull:
   3107       if (isTypeDependent() || getType()->isIntegralType(Ctx))
   3108         return NPCK_ZeroExpression;
   3109       else
   3110         return NPCK_NotNull;
   3111 
   3112     case NPC_ValueDependentIsNotNull:
   3113       return NPCK_NotNull;
   3114     }
   3115   }
   3116 
   3117   // Strip off a cast to void*, if it exists. Except in C++.
   3118   if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
   3119     if (!Ctx.getLangOpts().CPlusPlus) {
   3120       // Check that it is a cast to void*.
   3121       if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
   3122         QualType Pointee = PT->getPointeeType();
   3123         if (!Pointee.hasQualifiers() &&
   3124             Pointee->isVoidType() &&                              // to void*
   3125             CE->getSubExpr()->getType()->isIntegerType())         // from int.
   3126           return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
   3127       }
   3128     }
   3129   } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
   3130     // Ignore the ImplicitCastExpr type entirely.
   3131     return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
   3132   } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
   3133     // Accept ((void*)0) as a null pointer constant, as many other
   3134     // implementations do.
   3135     return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
   3136   } else if (const GenericSelectionExpr *GE =
   3137                dyn_cast<GenericSelectionExpr>(this)) {
   3138     if (GE->isResultDependent())
   3139       return NPCK_NotNull;
   3140     return GE->getResultExpr()->isNullPointerConstant(Ctx, NPC);
   3141   } else if (const ChooseExpr *CE = dyn_cast<ChooseExpr>(this)) {
   3142     if (CE->isConditionDependent())
   3143       return NPCK_NotNull;
   3144     return CE->getChosenSubExpr()->isNullPointerConstant(Ctx, NPC);
   3145   } else if (const CXXDefaultArgExpr *DefaultArg
   3146                = dyn_cast<CXXDefaultArgExpr>(this)) {
   3147     // See through default argument expressions.
   3148     return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
   3149   } else if (const CXXDefaultInitExpr *DefaultInit
   3150                = dyn_cast<CXXDefaultInitExpr>(this)) {
   3151     // See through default initializer expressions.
   3152     return DefaultInit->getExpr()->isNullPointerConstant(Ctx, NPC);
   3153   } else if (isa<GNUNullExpr>(this)) {
   3154     // The GNU __null extension is always a null pointer constant.
   3155     return NPCK_GNUNull;
   3156   } else if (const MaterializeTemporaryExpr *M
   3157                                    = dyn_cast<MaterializeTemporaryExpr>(this)) {
   3158     return M->GetTemporaryExpr()->isNullPointerConstant(Ctx, NPC);
   3159   } else if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(this)) {
   3160     if (const Expr *Source = OVE->getSourceExpr())
   3161       return Source->isNullPointerConstant(Ctx, NPC);
   3162   }
   3163 
   3164   // C++11 nullptr_t is always a null pointer constant.
   3165   if (getType()->isNullPtrType())
   3166     return NPCK_CXX11_nullptr;
   3167 
   3168   if (const RecordType *UT = getType()->getAsUnionType())
   3169     if (!Ctx.getLangOpts().CPlusPlus11 &&
   3170         UT && UT->getDecl()->hasAttr<TransparentUnionAttr>())
   3171       if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(this)){
   3172         const Expr *InitExpr = CLE->getInitializer();
   3173         if (const InitListExpr *ILE = dyn_cast<InitListExpr>(InitExpr))
   3174           return ILE->getInit(0)->isNullPointerConstant(Ctx, NPC);
   3175       }
   3176   // This expression must be an integer type.
   3177   if (!getType()->isIntegerType() ||
   3178       (Ctx.getLangOpts().CPlusPlus && getType()->isEnumeralType()))
   3179     return NPCK_NotNull;
   3180 
   3181   if (Ctx.getLangOpts().CPlusPlus11) {
   3182     // C++11 [conv.ptr]p1: A null pointer constant is an integer literal with
   3183     // value zero or a prvalue of type std::nullptr_t.
   3184     // Microsoft mode permits C++98 rules reflecting MSVC behavior.
   3185     const IntegerLiteral *Lit = dyn_cast<IntegerLiteral>(this);
   3186     if (Lit && !Lit->getValue())
   3187       return NPCK_ZeroLiteral;
   3188     else if (!Ctx.getLangOpts().MSVCCompat || !isCXX98IntegralConstantExpr(Ctx))
   3189       return NPCK_NotNull;
   3190   } else {
   3191     // If we have an integer constant expression, we need to *evaluate* it and
   3192     // test for the value 0.
   3193     if (!isIntegerConstantExpr(Ctx))
   3194       return NPCK_NotNull;
   3195   }
   3196 
   3197   if (EvaluateKnownConstInt(Ctx) != 0)
   3198     return NPCK_NotNull;
   3199 
   3200   if (isa<IntegerLiteral>(this))
   3201     return NPCK_ZeroLiteral;
   3202   return NPCK_ZeroExpression;
   3203 }
   3204 
   3205 /// \brief If this expression is an l-value for an Objective C
   3206 /// property, find the underlying property reference expression.
   3207 const ObjCPropertyRefExpr *Expr::getObjCProperty() const {
   3208   const Expr *E = this;
   3209   while (true) {
   3210     assert((E->getValueKind() == VK_LValue &&
   3211             E->getObjectKind() == OK_ObjCProperty) &&
   3212            "expression is not a property reference");
   3213     E = E->IgnoreParenCasts();
   3214     if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
   3215       if (BO->getOpcode() == BO_Comma) {
   3216         E = BO->getRHS();
   3217         continue;
   3218       }
   3219     }
   3220 
   3221     break;
   3222   }
   3223 
   3224   return cast<ObjCPropertyRefExpr>(E);
   3225 }
   3226 
   3227 bool Expr::isObjCSelfExpr() const {
   3228   const Expr *E = IgnoreParenImpCasts();
   3229 
   3230   const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E);
   3231   if (!DRE)
   3232     return false;
   3233 
   3234   const ImplicitParamDecl *Param = dyn_cast<ImplicitParamDecl>(DRE->getDecl());
   3235   if (!Param)
   3236     return false;
   3237 
   3238   const ObjCMethodDecl *M = dyn_cast<ObjCMethodDecl>(Param->getDeclContext());
   3239   if (!M)
   3240     return false;
   3241 
   3242   return M->getSelfDecl() == Param;
   3243 }
   3244 
   3245 FieldDecl *Expr::getSourceBitField() {
   3246   Expr *E = this->IgnoreParens();
   3247 
   3248   while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
   3249     if (ICE->getCastKind() == CK_LValueToRValue ||
   3250         (ICE->getValueKind() != VK_RValue && ICE->getCastKind() == CK_NoOp))
   3251       E = ICE->getSubExpr()->IgnoreParens();
   3252     else
   3253       break;
   3254   }
   3255 
   3256   if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
   3257     if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
   3258       if (Field->isBitField())
   3259         return Field;
   3260 
   3261   if (ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(E))
   3262     if (FieldDecl *Ivar = dyn_cast<FieldDecl>(IvarRef->getDecl()))
   3263       if (Ivar->isBitField())
   3264         return Ivar;
   3265 
   3266   if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E))
   3267     if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
   3268       if (Field->isBitField())
   3269         return Field;
   3270 
   3271   if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E)) {
   3272     if (BinOp->isAssignmentOp() && BinOp->getLHS())
   3273       return BinOp->getLHS()->getSourceBitField();
   3274 
   3275     if (BinOp->getOpcode() == BO_Comma && BinOp->getRHS())
   3276       return BinOp->getRHS()->getSourceBitField();
   3277   }
   3278 
   3279   return nullptr;
   3280 }
   3281 
   3282 bool Expr::refersToVectorElement() const {
   3283   const Expr *E = this->IgnoreParens();
   3284 
   3285   while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
   3286     if (ICE->getValueKind() != VK_RValue &&
   3287         ICE->getCastKind() == CK_NoOp)
   3288       E = ICE->getSubExpr()->IgnoreParens();
   3289     else
   3290       break;
   3291   }
   3292 
   3293   if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E))
   3294     return ASE->getBase()->getType()->isVectorType();
   3295 
   3296   if (isa<ExtVectorElementExpr>(E))
   3297     return true;
   3298 
   3299   return false;
   3300 }
   3301 
   3302 /// isArrow - Return true if the base expression is a pointer to vector,
   3303 /// return false if the base expression is a vector.
   3304 bool ExtVectorElementExpr::isArrow() const {
   3305   return getBase()->getType()->isPointerType();
   3306 }
   3307 
   3308 unsigned ExtVectorElementExpr::getNumElements() const {
   3309   if (const VectorType *VT = getType()->getAs<VectorType>())
   3310     return VT->getNumElements();
   3311   return 1;
   3312 }
   3313 
   3314 /// containsDuplicateElements - Return true if any element access is repeated.
   3315 bool ExtVectorElementExpr::containsDuplicateElements() const {
   3316   // FIXME: Refactor this code to an accessor on the AST node which returns the
   3317   // "type" of component access, and share with code below and in Sema.
   3318   StringRef Comp = Accessor->getName();
   3319 
   3320   // Halving swizzles do not contain duplicate elements.
   3321   if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
   3322     return false;
   3323 
   3324   // Advance past s-char prefix on hex swizzles.
   3325   if (Comp[0] == 's' || Comp[0] == 'S')
   3326     Comp = Comp.substr(1);
   3327 
   3328   for (unsigned i = 0, e = Comp.size(); i != e; ++i)
   3329     if (Comp.substr(i + 1).find(Comp[i]) != StringRef::npos)
   3330         return true;
   3331 
   3332   return false;
   3333 }
   3334 
   3335 /// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
   3336 void ExtVectorElementExpr::getEncodedElementAccess(
   3337                                   SmallVectorImpl<unsigned> &Elts) const {
   3338   StringRef Comp = Accessor->getName();
   3339   if (Comp[0] == 's' || Comp[0] == 'S')
   3340     Comp = Comp.substr(1);
   3341 
   3342   bool isHi =   Comp == "hi";
   3343   bool isLo =   Comp == "lo";
   3344   bool isEven = Comp == "even";
   3345   bool isOdd  = Comp == "odd";
   3346 
   3347   for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
   3348     uint64_t Index;
   3349 
   3350     if (isHi)
   3351       Index = e + i;
   3352     else if (isLo)
   3353       Index = i;
   3354     else if (isEven)
   3355       Index = 2 * i;
   3356     else if (isOdd)
   3357       Index = 2 * i + 1;
   3358     else
   3359       Index = ExtVectorType::getAccessorIdx(Comp[i]);
   3360 
   3361     Elts.push_back(Index);
   3362   }
   3363 }
   3364 
   3365 ObjCMessageExpr::ObjCMessageExpr(QualType T,
   3366                                  ExprValueKind VK,
   3367                                  SourceLocation LBracLoc,
   3368                                  SourceLocation SuperLoc,
   3369                                  bool IsInstanceSuper,
   3370                                  QualType SuperType,
   3371                                  Selector Sel,
   3372                                  ArrayRef<SourceLocation> SelLocs,
   3373                                  SelectorLocationsKind SelLocsK,
   3374                                  ObjCMethodDecl *Method,
   3375                                  ArrayRef<Expr *> Args,
   3376                                  SourceLocation RBracLoc,
   3377                                  bool isImplicit)
   3378   : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary,
   3379          /*TypeDependent=*/false, /*ValueDependent=*/false,
   3380          /*InstantiationDependent=*/false,
   3381          /*ContainsUnexpandedParameterPack=*/false),
   3382     SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
   3383                                                        : Sel.getAsOpaquePtr())),
   3384     Kind(IsInstanceSuper? SuperInstance : SuperClass),
   3385     HasMethod(Method != nullptr), IsDelegateInitCall(false),
   3386     IsImplicit(isImplicit), SuperLoc(SuperLoc), LBracLoc(LBracLoc),
   3387     RBracLoc(RBracLoc)
   3388 {
   3389   initArgsAndSelLocs(Args, SelLocs, SelLocsK);
   3390   setReceiverPointer(SuperType.getAsOpaquePtr());
   3391 }
   3392 
   3393 ObjCMessageExpr::ObjCMessageExpr(QualType T,
   3394                                  ExprValueKind VK,
   3395                                  SourceLocation LBracLoc,
   3396                                  TypeSourceInfo *Receiver,
   3397                                  Selector Sel,
   3398                                  ArrayRef<SourceLocation> SelLocs,
   3399                                  SelectorLocationsKind SelLocsK,
   3400                                  ObjCMethodDecl *Method,
   3401                                  ArrayRef<Expr *> Args,
   3402                                  SourceLocation RBracLoc,
   3403                                  bool isImplicit)
   3404   : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, T->isDependentType(),
   3405          T->isDependentType(), T->isInstantiationDependentType(),
   3406          T->containsUnexpandedParameterPack()),
   3407     SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
   3408                                                        : Sel.getAsOpaquePtr())),
   3409     Kind(Class),
   3410     HasMethod(Method != nullptr), IsDelegateInitCall(false),
   3411     IsImplicit(isImplicit), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
   3412 {
   3413   initArgsAndSelLocs(Args, SelLocs, SelLocsK);
   3414   setReceiverPointer(Receiver);
   3415 }
   3416 
   3417 ObjCMessageExpr::ObjCMessageExpr(QualType T,
   3418                                  ExprValueKind VK,
   3419                                  SourceLocation LBracLoc,
   3420                                  Expr *Receiver,
   3421                                  Selector Sel,
   3422                                  ArrayRef<SourceLocation> SelLocs,
   3423                                  SelectorLocationsKind SelLocsK,
   3424                                  ObjCMethodDecl *Method,
   3425                                  ArrayRef<Expr *> Args,
   3426                                  SourceLocation RBracLoc,
   3427                                  bool isImplicit)
   3428   : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, Receiver->isTypeDependent(),
   3429          Receiver->isTypeDependent(),
   3430          Receiver->isInstantiationDependent(),
   3431          Receiver->containsUnexpandedParameterPack()),
   3432     SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
   3433                                                        : Sel.getAsOpaquePtr())),
   3434     Kind(Instance),
   3435     HasMethod(Method != nullptr), IsDelegateInitCall(false),
   3436     IsImplicit(isImplicit), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
   3437 {
   3438   initArgsAndSelLocs(Args, SelLocs, SelLocsK);
   3439   setReceiverPointer(Receiver);
   3440 }
   3441 
   3442 void ObjCMessageExpr::initArgsAndSelLocs(ArrayRef<Expr *> Args,
   3443                                          ArrayRef<SourceLocation> SelLocs,
   3444                                          SelectorLocationsKind SelLocsK) {
   3445   setNumArgs(Args.size());
   3446   Expr **MyArgs = getArgs();
   3447   for (unsigned I = 0; I != Args.size(); ++I) {
   3448     if (Args[I]->isTypeDependent())
   3449       ExprBits.TypeDependent = true;
   3450     if (Args[I]->isValueDependent())
   3451       ExprBits.ValueDependent = true;
   3452     if (Args[I]->isInstantiationDependent())
   3453       ExprBits.InstantiationDependent = true;
   3454     if (Args[I]->containsUnexpandedParameterPack())
   3455       ExprBits.ContainsUnexpandedParameterPack = true;
   3456 
   3457     MyArgs[I] = Args[I];
   3458   }
   3459 
   3460   SelLocsKind = SelLocsK;
   3461   if (!isImplicit()) {
   3462     if (SelLocsK == SelLoc_NonStandard)
   3463       std::copy(SelLocs.begin(), SelLocs.end(), getStoredSelLocs());
   3464   }
   3465 }
   3466 
   3467 ObjCMessageExpr *ObjCMessageExpr::Create(const ASTContext &Context, QualType T,
   3468                                          ExprValueKind VK,
   3469                                          SourceLocation LBracLoc,
   3470                                          SourceLocation SuperLoc,
   3471                                          bool IsInstanceSuper,
   3472                                          QualType SuperType,
   3473                                          Selector Sel,
   3474                                          ArrayRef<SourceLocation> SelLocs,
   3475                                          ObjCMethodDecl *Method,
   3476                                          ArrayRef<Expr *> Args,
   3477                                          SourceLocation RBracLoc,
   3478                                          bool isImplicit) {
   3479   assert((!SelLocs.empty() || isImplicit) &&
   3480          "No selector locs for non-implicit message");
   3481   ObjCMessageExpr *Mem;
   3482   SelectorLocationsKind SelLocsK = SelectorLocationsKind();
   3483   if (isImplicit)
   3484     Mem = alloc(Context, Args.size(), 0);
   3485   else
   3486     Mem = alloc(Context, Args, RBracLoc, SelLocs, Sel, SelLocsK);
   3487   return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, SuperLoc, IsInstanceSuper,
   3488                                    SuperType, Sel, SelLocs, SelLocsK,
   3489                                    Method, Args, RBracLoc, isImplicit);
   3490 }
   3491 
   3492 ObjCMessageExpr *ObjCMessageExpr::Create(const ASTContext &Context, QualType T,
   3493                                          ExprValueKind VK,
   3494                                          SourceLocation LBracLoc,
   3495                                          TypeSourceInfo *Receiver,
   3496                                          Selector Sel,
   3497                                          ArrayRef<SourceLocation> SelLocs,
   3498                                          ObjCMethodDecl *Method,
   3499                                          ArrayRef<Expr *> Args,
   3500                                          SourceLocation RBracLoc,
   3501                                          bool isImplicit) {
   3502   assert((!SelLocs.empty() || isImplicit) &&
   3503          "No selector locs for non-implicit message");
   3504   ObjCMessageExpr *Mem;
   3505   SelectorLocationsKind SelLocsK = SelectorLocationsKind();
   3506   if (isImplicit)
   3507     Mem = alloc(Context, Args.size(), 0);
   3508   else
   3509     Mem = alloc(Context, Args, RBracLoc, SelLocs, Sel, SelLocsK);
   3510   return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel,
   3511                                    SelLocs, SelLocsK, Method, Args, RBracLoc,
   3512                                    isImplicit);
   3513 }
   3514 
   3515 ObjCMessageExpr *ObjCMessageExpr::Create(const ASTContext &Context, QualType T,
   3516                                          ExprValueKind VK,
   3517                                          SourceLocation LBracLoc,
   3518                                          Expr *Receiver,
   3519                                          Selector Sel,
   3520                                          ArrayRef<SourceLocation> SelLocs,
   3521                                          ObjCMethodDecl *Method,
   3522                                          ArrayRef<Expr *> Args,
   3523                                          SourceLocation RBracLoc,
   3524                                          bool isImplicit) {
   3525   assert((!SelLocs.empty() || isImplicit) &&
   3526          "No selector locs for non-implicit message");
   3527   ObjCMessageExpr *Mem;
   3528   SelectorLocationsKind SelLocsK = SelectorLocationsKind();
   3529   if (isImplicit)
   3530     Mem = alloc(Context, Args.size(), 0);
   3531   else
   3532     Mem = alloc(Context, Args, RBracLoc, SelLocs, Sel, SelLocsK);
   3533   return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel,
   3534                                    SelLocs, SelLocsK, Method, Args, RBracLoc,
   3535                                    isImplicit);
   3536 }
   3537 
   3538 ObjCMessageExpr *ObjCMessageExpr::CreateEmpty(const ASTContext &Context,
   3539                                               unsigned NumArgs,
   3540                                               unsigned NumStoredSelLocs) {
   3541   ObjCMessageExpr *Mem = alloc(Context, NumArgs, NumStoredSelLocs);
   3542   return new (Mem) ObjCMessageExpr(EmptyShell(), NumArgs);
   3543 }
   3544 
   3545 ObjCMessageExpr *ObjCMessageExpr::alloc(const ASTContext &C,
   3546                                         ArrayRef<Expr *> Args,
   3547                                         SourceLocation RBraceLoc,
   3548                                         ArrayRef<SourceLocation> SelLocs,
   3549                                         Selector Sel,
   3550                                         SelectorLocationsKind &SelLocsK) {
   3551   SelLocsK = hasStandardSelectorLocs(Sel, SelLocs, Args, RBraceLoc);
   3552   unsigned NumStoredSelLocs = (SelLocsK == SelLoc_NonStandard) ? SelLocs.size()
   3553                                                                : 0;
   3554   return alloc(C, Args.size(), NumStoredSelLocs);
   3555 }
   3556 
   3557 ObjCMessageExpr *ObjCMessageExpr::alloc(const ASTContext &C,
   3558                                         unsigned NumArgs,
   3559                                         unsigned NumStoredSelLocs) {
   3560   unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
   3561     NumArgs * sizeof(Expr *) + NumStoredSelLocs * sizeof(SourceLocation);
   3562   return (ObjCMessageExpr *)C.Allocate(Size,
   3563                                      llvm::AlignOf<ObjCMessageExpr>::Alignment);
   3564 }
   3565 
   3566 void ObjCMessageExpr::getSelectorLocs(
   3567                                SmallVectorImpl<SourceLocation> &SelLocs) const {
   3568   for (unsigned i = 0, e = getNumSelectorLocs(); i != e; ++i)
   3569     SelLocs.push_back(getSelectorLoc(i));
   3570 }
   3571 
   3572 SourceRange ObjCMessageExpr::getReceiverRange() const {
   3573   switch (getReceiverKind()) {
   3574   case Instance:
   3575     return getInstanceReceiver()->getSourceRange();
   3576 
   3577   case Class:
   3578     return getClassReceiverTypeInfo()->getTypeLoc().getSourceRange();
   3579 
   3580   case SuperInstance:
   3581   case SuperClass:
   3582     return getSuperLoc();
   3583   }
   3584 
   3585   llvm_unreachable("Invalid ReceiverKind!");
   3586 }
   3587 
   3588 Selector ObjCMessageExpr::getSelector() const {
   3589   if (HasMethod)
   3590     return reinterpret_cast<const ObjCMethodDecl *>(SelectorOrMethod)
   3591                                                                ->getSelector();
   3592   return Selector(SelectorOrMethod);
   3593 }
   3594 
   3595 QualType ObjCMessageExpr::getReceiverType() const {
   3596   switch (getReceiverKind()) {
   3597   case Instance:
   3598     return getInstanceReceiver()->getType();
   3599   case Class:
   3600     return getClassReceiver();
   3601   case SuperInstance:
   3602   case SuperClass:
   3603     return getSuperType();
   3604   }
   3605 
   3606   llvm_unreachable("unexpected receiver kind");
   3607 }
   3608 
   3609 ObjCInterfaceDecl *ObjCMessageExpr::getReceiverInterface() const {
   3610   QualType T = getReceiverType();
   3611 
   3612   if (const ObjCObjectPointerType *Ptr = T->getAs<ObjCObjectPointerType>())
   3613     return Ptr->getInterfaceDecl();
   3614 
   3615   if (const ObjCObjectType *Ty = T->getAs<ObjCObjectType>())
   3616     return Ty->getInterface();
   3617 
   3618   return nullptr;
   3619 }
   3620 
   3621 StringRef ObjCBridgedCastExpr::getBridgeKindName() const {
   3622   switch (getBridgeKind()) {
   3623   case OBC_Bridge:
   3624     return "__bridge";
   3625   case OBC_BridgeTransfer:
   3626     return "__bridge_transfer";
   3627   case OBC_BridgeRetained:
   3628     return "__bridge_retained";
   3629   }
   3630 
   3631   llvm_unreachable("Invalid BridgeKind!");
   3632 }
   3633 
   3634 ShuffleVectorExpr::ShuffleVectorExpr(const ASTContext &C, ArrayRef<Expr*> args,
   3635                                      QualType Type, SourceLocation BLoc,
   3636                                      SourceLocation RP)
   3637    : Expr(ShuffleVectorExprClass, Type, VK_RValue, OK_Ordinary,
   3638           Type->isDependentType(), Type->isDependentType(),
   3639           Type->isInstantiationDependentType(),
   3640           Type->containsUnexpandedParameterPack()),
   3641      BuiltinLoc(BLoc), RParenLoc(RP), NumExprs(args.size())
   3642 {
   3643   SubExprs = new (C) Stmt*[args.size()];
   3644   for (unsigned i = 0; i != args.size(); i++) {
   3645     if (args[i]->isTypeDependent())
   3646       ExprBits.TypeDependent = true;
   3647     if (args[i]->isValueDependent())
   3648       ExprBits.ValueDependent = true;
   3649     if (args[i]->isInstantiationDependent())
   3650       ExprBits.InstantiationDependent = true;
   3651     if (args[i]->containsUnexpandedParameterPack())
   3652       ExprBits.ContainsUnexpandedParameterPack = true;
   3653 
   3654     SubExprs[i] = args[i];
   3655   }
   3656 }
   3657 
   3658 void ShuffleVectorExpr::setExprs(const ASTContext &C, ArrayRef<Expr *> Exprs) {
   3659   if (SubExprs) C.Deallocate(SubExprs);
   3660 
   3661   this->NumExprs = Exprs.size();
   3662   SubExprs = new (C) Stmt*[NumExprs];
   3663   memcpy(SubExprs, Exprs.data(), sizeof(Expr *) * Exprs.size());
   3664 }
   3665 
   3666 GenericSelectionExpr::GenericSelectionExpr(const ASTContext &Context,
   3667                                SourceLocation GenericLoc, Expr *ControllingExpr,
   3668                                ArrayRef<TypeSourceInfo*> AssocTypes,
   3669                                ArrayRef<Expr*> AssocExprs,
   3670                                SourceLocation DefaultLoc,
   3671                                SourceLocation RParenLoc,
   3672                                bool ContainsUnexpandedParameterPack,
   3673                                unsigned ResultIndex)
   3674   : Expr(GenericSelectionExprClass,
   3675          AssocExprs[ResultIndex]->getType(),
   3676          AssocExprs[ResultIndex]->getValueKind(),
   3677          AssocExprs[ResultIndex]->getObjectKind(),
   3678          AssocExprs[ResultIndex]->isTypeDependent(),
   3679          AssocExprs[ResultIndex]->isValueDependent(),
   3680          AssocExprs[ResultIndex]->isInstantiationDependent(),
   3681          ContainsUnexpandedParameterPack),
   3682     AssocTypes(new (Context) TypeSourceInfo*[AssocTypes.size()]),
   3683     SubExprs(new (Context) Stmt*[END_EXPR+AssocExprs.size()]),
   3684     NumAssocs(AssocExprs.size()), ResultIndex(ResultIndex),
   3685     GenericLoc(GenericLoc), DefaultLoc(DefaultLoc), RParenLoc(RParenLoc) {
   3686   SubExprs[CONTROLLING] = ControllingExpr;
   3687   assert(AssocTypes.size() == AssocExprs.size());
   3688   std::copy(AssocTypes.begin(), AssocTypes.end(), this->AssocTypes);
   3689   std::copy(AssocExprs.begin(), AssocExprs.end(), SubExprs+END_EXPR);
   3690 }
   3691 
   3692 GenericSelectionExpr::GenericSelectionExpr(const ASTContext &Context,
   3693                                SourceLocation GenericLoc, Expr *ControllingExpr,
   3694                                ArrayRef<TypeSourceInfo*> AssocTypes,
   3695                                ArrayRef<Expr*> AssocExprs,
   3696                                SourceLocation DefaultLoc,
   3697                                SourceLocation RParenLoc,
   3698                                bool ContainsUnexpandedParameterPack)
   3699   : Expr(GenericSelectionExprClass,
   3700          Context.DependentTy,
   3701          VK_RValue,
   3702          OK_Ordinary,
   3703          /*isTypeDependent=*/true,
   3704          /*isValueDependent=*/true,
   3705          /*isInstantiationDependent=*/true,
   3706          ContainsUnexpandedParameterPack),
   3707     AssocTypes(new (Context) TypeSourceInfo*[AssocTypes.size()]),
   3708     SubExprs(new (Context) Stmt*[END_EXPR+AssocExprs.size()]),
   3709     NumAssocs(AssocExprs.size()), ResultIndex(-1U), GenericLoc(GenericLoc),
   3710     DefaultLoc(DefaultLoc), RParenLoc(RParenLoc) {
   3711   SubExprs[CONTROLLING] = ControllingExpr;
   3712   assert(AssocTypes.size() == AssocExprs.size());
   3713   std::copy(AssocTypes.begin(), AssocTypes.end(), this->AssocTypes);
   3714   std::copy(AssocExprs.begin(), AssocExprs.end(), SubExprs+END_EXPR);
   3715 }
   3716 
   3717 //===----------------------------------------------------------------------===//
   3718 //  DesignatedInitExpr
   3719 //===----------------------------------------------------------------------===//
   3720 
   3721 IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() const {
   3722   assert(Kind == FieldDesignator && "Only valid on a field designator");
   3723   if (Field.NameOrField & 0x01)
   3724     return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
   3725   else
   3726     return getField()->getIdentifier();
   3727 }
   3728 
   3729 DesignatedInitExpr::DesignatedInitExpr(const ASTContext &C, QualType Ty,
   3730                                        unsigned NumDesignators,
   3731                                        const Designator *Designators,
   3732                                        SourceLocation EqualOrColonLoc,
   3733                                        bool GNUSyntax,
   3734                                        ArrayRef<Expr*> IndexExprs,
   3735                                        Expr *Init)
   3736   : Expr(DesignatedInitExprClass, Ty,
   3737          Init->getValueKind(), Init->getObjectKind(),
   3738          Init->isTypeDependent(), Init->isValueDependent(),
   3739          Init->isInstantiationDependent(),
   3740          Init->containsUnexpandedParameterPack()),
   3741     EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
   3742     NumDesignators(NumDesignators), NumSubExprs(IndexExprs.size() + 1) {
   3743   this->Designators = new (C) Designator[NumDesignators];
   3744 
   3745   // Record the initializer itself.
   3746   child_range Child = children();
   3747   *Child++ = Init;
   3748 
   3749   // Copy the designators and their subexpressions, computing
   3750   // value-dependence along the way.
   3751   unsigned IndexIdx = 0;
   3752   for (unsigned I = 0; I != NumDesignators; ++I) {
   3753     this->Designators[I] = Designators[I];
   3754 
   3755     if (this->Designators[I].isArrayDesignator()) {
   3756       // Compute type- and value-dependence.
   3757       Expr *Index = IndexExprs[IndexIdx];
   3758       if (Index->isTypeDependent() || Index->isValueDependent())
   3759         ExprBits.ValueDependent = true;
   3760       if (Index->isInstantiationDependent())
   3761         ExprBits.InstantiationDependent = true;
   3762       // Propagate unexpanded parameter packs.
   3763       if (Index->containsUnexpandedParameterPack())
   3764         ExprBits.ContainsUnexpandedParameterPack = true;
   3765 
   3766       // Copy the index expressions into permanent storage.
   3767       *Child++ = IndexExprs[IndexIdx++];
   3768     } else if (this->Designators[I].isArrayRangeDesignator()) {
   3769       // Compute type- and value-dependence.
   3770       Expr *Start = IndexExprs[IndexIdx];
   3771       Expr *End = IndexExprs[IndexIdx + 1];
   3772       if (Start->isTypeDependent() || Start->isValueDependent() ||
   3773           End->isTypeDependent() || End->isValueDependent()) {
   3774         ExprBits.ValueDependent = true;
   3775         ExprBits.InstantiationDependent = true;
   3776       } else if (Start->isInstantiationDependent() ||
   3777                  End->isInstantiationDependent()) {
   3778         ExprBits.InstantiationDependent = true;
   3779       }
   3780 
   3781       // Propagate unexpanded parameter packs.
   3782       if (Start->containsUnexpandedParameterPack() ||
   3783           End->containsUnexpandedParameterPack())
   3784         ExprBits.ContainsUnexpandedParameterPack = true;
   3785 
   3786       // Copy the start/end expressions into permanent storage.
   3787       *Child++ = IndexExprs[IndexIdx++];
   3788       *Child++ = IndexExprs[IndexIdx++];
   3789     }
   3790   }
   3791 
   3792   assert(IndexIdx == IndexExprs.size() && "Wrong number of index expressions");
   3793 }
   3794 
   3795 DesignatedInitExpr *
   3796 DesignatedInitExpr::Create(const ASTContext &C, Designator *Designators,
   3797                            unsigned NumDesignators,
   3798                            ArrayRef<Expr*> IndexExprs,
   3799                            SourceLocation ColonOrEqualLoc,
   3800                            bool UsesColonSyntax, Expr *Init) {
   3801   void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
   3802                          sizeof(Stmt *) * (IndexExprs.size() + 1), 8);
   3803   return new (Mem) DesignatedInitExpr(C, C.VoidTy, NumDesignators, Designators,
   3804                                       ColonOrEqualLoc, UsesColonSyntax,
   3805                                       IndexExprs, Init);
   3806 }
   3807 
   3808 DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(const ASTContext &C,
   3809                                                     unsigned NumIndexExprs) {
   3810   void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
   3811                          sizeof(Stmt *) * (NumIndexExprs + 1), 8);
   3812   return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
   3813 }
   3814 
   3815 void DesignatedInitExpr::setDesignators(const ASTContext &C,
   3816                                         const Designator *Desigs,
   3817                                         unsigned NumDesigs) {
   3818   Designators = new (C) Designator[NumDesigs];
   3819   NumDesignators = NumDesigs;
   3820   for (unsigned I = 0; I != NumDesigs; ++I)
   3821     Designators[I] = Desigs[I];
   3822 }
   3823 
   3824 SourceRange DesignatedInitExpr::getDesignatorsSourceRange() const {
   3825   DesignatedInitExpr *DIE = const_cast<DesignatedInitExpr*>(this);
   3826   if (size() == 1)
   3827     return DIE->getDesignator(0)->getSourceRange();
   3828   return SourceRange(DIE->getDesignator(0)->getLocStart(),
   3829                      DIE->getDesignator(size()-1)->getLocEnd());
   3830 }
   3831 
   3832 SourceLocation DesignatedInitExpr::getLocStart() const {
   3833   SourceLocation StartLoc;
   3834   Designator &First =
   3835     *const_cast<DesignatedInitExpr*>(this)->designators_begin();
   3836   if (First.isFieldDesignator()) {
   3837     if (GNUSyntax)
   3838       StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
   3839     else
   3840       StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
   3841   } else
   3842     StartLoc =
   3843       SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
   3844   return StartLoc;
   3845 }
   3846 
   3847 SourceLocation DesignatedInitExpr::getLocEnd() const {
   3848   return getInit()->getLocEnd();
   3849 }
   3850 
   3851 Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) const {
   3852   assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
   3853   Stmt *const *SubExprs = reinterpret_cast<Stmt *const *>(this + 1);
   3854   return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
   3855 }
   3856 
   3857 Expr *DesignatedInitExpr::getArrayRangeStart(const Designator &D) const {
   3858   assert(D.Kind == Designator::ArrayRangeDesignator &&
   3859          "Requires array range designator");
   3860   Stmt *const *SubExprs = reinterpret_cast<Stmt *const *>(this + 1);
   3861   return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
   3862 }
   3863 
   3864 Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator &D) const {
   3865   assert(D.Kind == Designator::ArrayRangeDesignator &&
   3866          "Requires array range designator");
   3867   Stmt *const *SubExprs = reinterpret_cast<Stmt *const *>(this + 1);
   3868   return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
   3869 }
   3870 
   3871 /// \brief Replaces the designator at index @p Idx with the series
   3872 /// of designators in [First, Last).
   3873 void DesignatedInitExpr::ExpandDesignator(const ASTContext &C, unsigned Idx,
   3874                                           const Designator *First,
   3875                                           const Designator *Last) {
   3876   unsigned NumNewDesignators = Last - First;
   3877   if (NumNewDesignators == 0) {
   3878     std::copy_backward(Designators + Idx + 1,
   3879                        Designators + NumDesignators,
   3880                        Designators + Idx);
   3881     --NumNewDesignators;
   3882     return;
   3883   } else if (NumNewDesignators == 1) {
   3884     Designators[Idx] = *First;
   3885     return;
   3886   }
   3887 
   3888   Designator *NewDesignators
   3889     = new (C) Designator[NumDesignators - 1 + NumNewDesignators];
   3890   std::copy(Designators, Designators + Idx, NewDesignators);
   3891   std::copy(First, Last, NewDesignators + Idx);
   3892   std::copy(Designators + Idx + 1, Designators + NumDesignators,
   3893             NewDesignators + Idx + NumNewDesignators);
   3894   Designators = NewDesignators;
   3895   NumDesignators = NumDesignators - 1 + NumNewDesignators;
   3896 }
   3897 
   3898 ParenListExpr::ParenListExpr(const ASTContext& C, SourceLocation lparenloc,
   3899                              ArrayRef<Expr*> exprs,
   3900                              SourceLocation rparenloc)
   3901   : Expr(ParenListExprClass, QualType(), VK_RValue, OK_Ordinary,
   3902          false, false, false, false),
   3903     NumExprs(exprs.size()), LParenLoc(lparenloc), RParenLoc(rparenloc) {
   3904   Exprs = new (C) Stmt*[exprs.size()];
   3905   for (unsigned i = 0; i != exprs.size(); ++i) {
   3906     if (exprs[i]->isTypeDependent())
   3907       ExprBits.TypeDependent = true;
   3908     if (exprs[i]->isValueDependent())
   3909       ExprBits.ValueDependent = true;
   3910     if (exprs[i]->isInstantiationDependent())
   3911       ExprBits.InstantiationDependent = true;
   3912     if (exprs[i]->containsUnexpandedParameterPack())
   3913       ExprBits.ContainsUnexpandedParameterPack = true;
   3914 
   3915     Exprs[i] = exprs[i];
   3916   }
   3917 }
   3918 
   3919 const OpaqueValueExpr *OpaqueValueExpr::findInCopyConstruct(const Expr *e) {
   3920   if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(e))
   3921     e = ewc->getSubExpr();
   3922   if (const MaterializeTemporaryExpr *m = dyn_cast<MaterializeTemporaryExpr>(e))
   3923     e = m->GetTemporaryExpr();
   3924   e = cast<CXXConstructExpr>(e)->getArg(0);
   3925   while (const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
   3926     e = ice->getSubExpr();
   3927   return cast<OpaqueValueExpr>(e);
   3928 }
   3929 
   3930 PseudoObjectExpr *PseudoObjectExpr::Create(const ASTContext &Context,
   3931                                            EmptyShell sh,
   3932                                            unsigned numSemanticExprs) {
   3933   void *buffer = Context.Allocate(sizeof(PseudoObjectExpr) +
   3934                                     (1 + numSemanticExprs) * sizeof(Expr*),
   3935                                   llvm::alignOf<PseudoObjectExpr>());
   3936   return new(buffer) PseudoObjectExpr(sh, numSemanticExprs);
   3937 }
   3938 
   3939 PseudoObjectExpr::PseudoObjectExpr(EmptyShell shell, unsigned numSemanticExprs)
   3940   : Expr(PseudoObjectExprClass, shell) {
   3941   PseudoObjectExprBits.NumSubExprs = numSemanticExprs + 1;
   3942 }
   3943 
   3944 PseudoObjectExpr *PseudoObjectExpr::Create(const ASTContext &C, Expr *syntax,
   3945                                            ArrayRef<Expr*> semantics,
   3946                                            unsigned resultIndex) {
   3947   assert(syntax && "no syntactic expression!");
   3948   assert(semantics.size() && "no semantic expressions!");
   3949 
   3950   QualType type;
   3951   ExprValueKind VK;
   3952   if (resultIndex == NoResult) {
   3953     type = C.VoidTy;
   3954     VK = VK_RValue;
   3955   } else {
   3956     assert(resultIndex < semantics.size());
   3957     type = semantics[resultIndex]->getType();
   3958     VK = semantics[resultIndex]->getValueKind();
   3959     assert(semantics[resultIndex]->getObjectKind() == OK_Ordinary);
   3960   }
   3961 
   3962   void *buffer = C.Allocate(sizeof(PseudoObjectExpr) +
   3963                               (1 + semantics.size()) * sizeof(Expr*),
   3964                             llvm::alignOf<PseudoObjectExpr>());
   3965   return new(buffer) PseudoObjectExpr(type, VK, syntax, semantics,
   3966                                       resultIndex);
   3967 }
   3968 
   3969 PseudoObjectExpr::PseudoObjectExpr(QualType type, ExprValueKind VK,
   3970                                    Expr *syntax, ArrayRef<Expr*> semantics,
   3971                                    unsigned resultIndex)
   3972   : Expr(PseudoObjectExprClass, type, VK, OK_Ordinary,
   3973          /*filled in at end of ctor*/ false, false, false, false) {
   3974   PseudoObjectExprBits.NumSubExprs = semantics.size() + 1;
   3975   PseudoObjectExprBits.ResultIndex = resultIndex + 1;
   3976 
   3977   for (unsigned i = 0, e = semantics.size() + 1; i != e; ++i) {
   3978     Expr *E = (i == 0 ? syntax : semantics[i-1]);
   3979     getSubExprsBuffer()[i] = E;
   3980 
   3981     if (E->isTypeDependent())
   3982       ExprBits.TypeDependent = true;
   3983     if (E->isValueDependent())
   3984       ExprBits.ValueDependent = true;
   3985     if (E->isInstantiationDependent())
   3986       ExprBits.InstantiationDependent = true;
   3987     if (E->containsUnexpandedParameterPack())
   3988       ExprBits.ContainsUnexpandedParameterPack = true;
   3989 
   3990     if (isa<OpaqueValueExpr>(E))
   3991       assert(cast<OpaqueValueExpr>(E)->getSourceExpr() != nullptr &&
   3992              "opaque-value semantic expressions for pseudo-object "
   3993              "operations must have sources");
   3994   }
   3995 }
   3996 
   3997 //===----------------------------------------------------------------------===//
   3998 //  ExprIterator.
   3999 //===----------------------------------------------------------------------===//
   4000 
   4001 Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
   4002 Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
   4003 Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
   4004 const Expr* ConstExprIterator::operator[](size_t idx) const {
   4005   return cast<Expr>(I[idx]);
   4006 }
   4007 const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
   4008 const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
   4009 
   4010 //===----------------------------------------------------------------------===//
   4011 //  Child Iterators for iterating over subexpressions/substatements
   4012 //===----------------------------------------------------------------------===//
   4013 
   4014 // UnaryExprOrTypeTraitExpr
   4015 Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
   4016   // If this is of a type and the type is a VLA type (and not a typedef), the
   4017   // size expression of the VLA needs to be treated as an executable expression.
   4018   // Why isn't this weirdness documented better in StmtIterator?
   4019   if (isArgumentType()) {
   4020     if (const VariableArrayType* T = dyn_cast<VariableArrayType>(
   4021                                    getArgumentType().getTypePtr()))
   4022       return child_range(child_iterator(T), child_iterator());
   4023     return child_range();
   4024   }
   4025   return child_range(&Argument.Ex, &Argument.Ex + 1);
   4026 }
   4027 
   4028 // ObjCMessageExpr
   4029 Stmt::child_range ObjCMessageExpr::children() {
   4030   Stmt **begin;
   4031   if (getReceiverKind() == Instance)
   4032     begin = reinterpret_cast<Stmt **>(this + 1);
   4033   else
   4034     begin = reinterpret_cast<Stmt **>(getArgs());
   4035   return child_range(begin,
   4036                      reinterpret_cast<Stmt **>(getArgs() + getNumArgs()));
   4037 }
   4038 
   4039 ObjCArrayLiteral::ObjCArrayLiteral(ArrayRef<Expr *> Elements,
   4040                                    QualType T, ObjCMethodDecl *Method,
   4041                                    SourceRange SR)
   4042   : Expr(ObjCArrayLiteralClass, T, VK_RValue, OK_Ordinary,
   4043          false, false, false, false),
   4044     NumElements(Elements.size()), Range(SR), ArrayWithObjectsMethod(Method)
   4045 {
   4046   Expr **SaveElements = getElements();
   4047   for (unsigned I = 0, N = Elements.size(); I != N; ++I) {
   4048     if (Elements[I]->isTypeDependent() || Elements[I]->isValueDependent())
   4049       ExprBits.ValueDependent = true;
   4050     if (Elements[I]->isInstantiationDependent())
   4051       ExprBits.InstantiationDependent = true;
   4052     if (Elements[I]->containsUnexpandedParameterPack())
   4053       ExprBits.ContainsUnexpandedParameterPack = true;
   4054 
   4055     SaveElements[I] = Elements[I];
   4056   }
   4057 }
   4058 
   4059 ObjCArrayLiteral *ObjCArrayLiteral::Create(const ASTContext &C,
   4060                                            ArrayRef<Expr *> Elements,
   4061                                            QualType T, ObjCMethodDecl * Method,
   4062                                            SourceRange SR) {
   4063   void *Mem = C.Allocate(sizeof(ObjCArrayLiteral)
   4064                          + Elements.size() * sizeof(Expr *));
   4065   return new (Mem) ObjCArrayLiteral(Elements, T, Method, SR);
   4066 }
   4067 
   4068 ObjCArrayLiteral *ObjCArrayLiteral::CreateEmpty(const ASTContext &C,
   4069                                                 unsigned NumElements) {
   4070 
   4071   void *Mem = C.Allocate(sizeof(ObjCArrayLiteral)
   4072                          + NumElements * sizeof(Expr *));
   4073   return new (Mem) ObjCArrayLiteral(EmptyShell(), NumElements);
   4074 }
   4075 
   4076 ObjCDictionaryLiteral::ObjCDictionaryLiteral(
   4077                                              ArrayRef<ObjCDictionaryElement> VK,
   4078                                              bool HasPackExpansions,
   4079                                              QualType T, ObjCMethodDecl *method,
   4080                                              SourceRange SR)
   4081   : Expr(ObjCDictionaryLiteralClass, T, VK_RValue, OK_Ordinary, false, false,
   4082          false, false),
   4083     NumElements(VK.size()), HasPackExpansions(HasPackExpansions), Range(SR),
   4084     DictWithObjectsMethod(method)
   4085 {
   4086   KeyValuePair *KeyValues = getKeyValues();
   4087   ExpansionData *Expansions = getExpansionData();
   4088   for (unsigned I = 0; I < NumElements; I++) {
   4089     if (VK[I].Key->isTypeDependent() || VK[I].Key->isValueDependent() ||
   4090         VK[I].Value->isTypeDependent() || VK[I].Value->isValueDependent())
   4091       ExprBits.ValueDependent = true;
   4092     if (VK[I].Key->isInstantiationDependent() ||
   4093         VK[I].Value->isInstantiationDependent())
   4094       ExprBits.InstantiationDependent = true;
   4095     if (VK[I].EllipsisLoc.isInvalid() &&
   4096         (VK[I].Key->containsUnexpandedParameterPack() ||
   4097          VK[I].Value->containsUnexpandedParameterPack()))
   4098       ExprBits.ContainsUnexpandedParameterPack = true;
   4099 
   4100     KeyValues[I].Key = VK[I].Key;
   4101     KeyValues[I].Value = VK[I].Value;
   4102     if (Expansions) {
   4103       Expansions[I].EllipsisLoc = VK[I].EllipsisLoc;
   4104       if (VK[I].NumExpansions)
   4105         Expansions[I].NumExpansionsPlusOne = *VK[I].NumExpansions + 1;
   4106       else
   4107         Expansions[I].NumExpansionsPlusOne = 0;
   4108     }
   4109   }
   4110 }
   4111 
   4112 ObjCDictionaryLiteral *
   4113 ObjCDictionaryLiteral::Create(const ASTContext &C,
   4114                               ArrayRef<ObjCDictionaryElement> VK,
   4115                               bool HasPackExpansions,
   4116                               QualType T, ObjCMethodDecl *method,
   4117                               SourceRange SR) {
   4118   unsigned ExpansionsSize = 0;
   4119   if (HasPackExpansions)
   4120     ExpansionsSize = sizeof(ExpansionData) * VK.size();
   4121 
   4122   void *Mem = C.Allocate(sizeof(ObjCDictionaryLiteral) +
   4123                          sizeof(KeyValuePair) * VK.size() + ExpansionsSize);
   4124   return new (Mem) ObjCDictionaryLiteral(VK, HasPackExpansions, T, method, SR);
   4125 }
   4126 
   4127 ObjCDictionaryLiteral *
   4128 ObjCDictionaryLiteral::CreateEmpty(const ASTContext &C, unsigned NumElements,
   4129                                    bool HasPackExpansions) {
   4130   unsigned ExpansionsSize = 0;
   4131   if (HasPackExpansions)
   4132     ExpansionsSize = sizeof(ExpansionData) * NumElements;
   4133   void *Mem = C.Allocate(sizeof(ObjCDictionaryLiteral) +
   4134                          sizeof(KeyValuePair) * NumElements + ExpansionsSize);
   4135   return new (Mem) ObjCDictionaryLiteral(EmptyShell(), NumElements,
   4136                                          HasPackExpansions);
   4137 }
   4138 
   4139 ObjCSubscriptRefExpr *ObjCSubscriptRefExpr::Create(const ASTContext &C,
   4140                                                    Expr *base,
   4141                                                    Expr *key, QualType T,
   4142                                                    ObjCMethodDecl *getMethod,
   4143                                                    ObjCMethodDecl *setMethod,
   4144                                                    SourceLocation RB) {
   4145   void *Mem = C.Allocate(sizeof(ObjCSubscriptRefExpr));
   4146   return new (Mem) ObjCSubscriptRefExpr(base, key, T, VK_LValue,
   4147                                         OK_ObjCSubscript,
   4148                                         getMethod, setMethod, RB);
   4149 }
   4150 
   4151 AtomicExpr::AtomicExpr(SourceLocation BLoc, ArrayRef<Expr*> args,
   4152                        QualType t, AtomicOp op, SourceLocation RP)
   4153   : Expr(AtomicExprClass, t, VK_RValue, OK_Ordinary,
   4154          false, false, false, false),
   4155     NumSubExprs(args.size()), BuiltinLoc(BLoc), RParenLoc(RP), Op(op)
   4156 {
   4157   assert(args.size() == getNumSubExprs(op) && "wrong number of subexpressions");
   4158   for (unsigned i = 0; i != args.size(); i++) {
   4159     if (args[i]->isTypeDependent())
   4160       ExprBits.TypeDependent = true;
   4161     if (args[i]->isValueDependent())
   4162       ExprBits.ValueDependent = true;
   4163     if (args[i]->isInstantiationDependent())
   4164       ExprBits.InstantiationDependent = true;
   4165     if (args[i]->containsUnexpandedParameterPack())
   4166       ExprBits.ContainsUnexpandedParameterPack = true;
   4167 
   4168     SubExprs[i] = args[i];
   4169   }
   4170 }
   4171 
   4172 unsigned AtomicExpr::getNumSubExprs(AtomicOp Op) {
   4173   switch (Op) {
   4174   case AO__c11_atomic_init:
   4175   case AO__c11_atomic_load:
   4176   case AO__atomic_load_n:
   4177     return 2;
   4178 
   4179   case AO__c11_atomic_store:
   4180   case AO__c11_atomic_exchange:
   4181   case AO__atomic_load:
   4182   case AO__atomic_store:
   4183   case AO__atomic_store_n:
   4184   case AO__atomic_exchange_n:
   4185   case AO__c11_atomic_fetch_add:
   4186   case AO__c11_atomic_fetch_sub:
   4187   case AO__c11_atomic_fetch_and:
   4188   case AO__c11_atomic_fetch_or:
   4189   case AO__c11_atomic_fetch_xor:
   4190   case AO__atomic_fetch_add:
   4191   case AO__atomic_fetch_sub:
   4192   case AO__atomic_fetch_and:
   4193   case AO__atomic_fetch_or:
   4194   case AO__atomic_fetch_xor:
   4195   case AO__atomic_fetch_nand:
   4196   case AO__atomic_add_fetch:
   4197   case AO__atomic_sub_fetch:
   4198   case AO__atomic_and_fetch:
   4199   case AO__atomic_or_fetch:
   4200   case AO__atomic_xor_fetch:
   4201   case AO__atomic_nand_fetch:
   4202     return 3;
   4203 
   4204   case AO__atomic_exchange:
   4205     return 4;
   4206 
   4207   case AO__c11_atomic_compare_exchange_strong:
   4208   case AO__c11_atomic_compare_exchange_weak:
   4209     return 5;
   4210 
   4211   case AO__atomic_compare_exchange:
   4212   case AO__atomic_compare_exchange_n:
   4213     return 6;
   4214   }
   4215   llvm_unreachable("unknown atomic op");
   4216 }
   4217