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      1 //===--- Type.cpp - Type representation and manipulation ------------------===//
      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 type-related functionality.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/AST/ASTContext.h"
     15 #include "clang/AST/CharUnits.h"
     16 #include "clang/AST/Type.h"
     17 #include "clang/AST/DeclCXX.h"
     18 #include "clang/AST/DeclObjC.h"
     19 #include "clang/AST/DeclTemplate.h"
     20 #include "clang/AST/Expr.h"
     21 #include "clang/AST/PrettyPrinter.h"
     22 #include "clang/AST/TypeVisitor.h"
     23 #include "clang/Basic/Specifiers.h"
     24 #include "llvm/ADT/APSInt.h"
     25 #include "llvm/ADT/StringExtras.h"
     26 #include "llvm/Support/raw_ostream.h"
     27 #include <algorithm>
     28 using namespace clang;
     29 
     30 bool Qualifiers::isStrictSupersetOf(Qualifiers Other) const {
     31   return (*this != Other) &&
     32     // CVR qualifiers superset
     33     (((Mask & CVRMask) | (Other.Mask & CVRMask)) == (Mask & CVRMask)) &&
     34     // ObjC GC qualifiers superset
     35     ((getObjCGCAttr() == Other.getObjCGCAttr()) ||
     36      (hasObjCGCAttr() && !Other.hasObjCGCAttr())) &&
     37     // Address space superset.
     38     ((getAddressSpace() == Other.getAddressSpace()) ||
     39      (hasAddressSpace()&& !Other.hasAddressSpace())) &&
     40     // Lifetime qualifier superset.
     41     ((getObjCLifetime() == Other.getObjCLifetime()) ||
     42      (hasObjCLifetime() && !Other.hasObjCLifetime()));
     43 }
     44 
     45 const IdentifierInfo* QualType::getBaseTypeIdentifier() const {
     46   const Type* ty = getTypePtr();
     47   NamedDecl *ND = NULL;
     48   if (ty->isPointerType() || ty->isReferenceType())
     49     return ty->getPointeeType().getBaseTypeIdentifier();
     50   else if (ty->isRecordType())
     51     ND = ty->getAs<RecordType>()->getDecl();
     52   else if (ty->isEnumeralType())
     53     ND = ty->getAs<EnumType>()->getDecl();
     54   else if (ty->getTypeClass() == Type::Typedef)
     55     ND = ty->getAs<TypedefType>()->getDecl();
     56   else if (ty->isArrayType())
     57     return ty->castAsArrayTypeUnsafe()->
     58         getElementType().getBaseTypeIdentifier();
     59 
     60   if (ND)
     61     return ND->getIdentifier();
     62   return NULL;
     63 }
     64 
     65 bool QualType::isConstant(QualType T, ASTContext &Ctx) {
     66   if (T.isConstQualified())
     67     return true;
     68 
     69   if (const ArrayType *AT = Ctx.getAsArrayType(T))
     70     return AT->getElementType().isConstant(Ctx);
     71 
     72   return false;
     73 }
     74 
     75 unsigned ConstantArrayType::getNumAddressingBits(ASTContext &Context,
     76                                                  QualType ElementType,
     77                                                const llvm::APInt &NumElements) {
     78   llvm::APSInt SizeExtended(NumElements, true);
     79   unsigned SizeTypeBits = Context.getTypeSize(Context.getSizeType());
     80   SizeExtended = SizeExtended.extend(std::max(SizeTypeBits,
     81                                               SizeExtended.getBitWidth()) * 2);
     82 
     83   uint64_t ElementSize
     84     = Context.getTypeSizeInChars(ElementType).getQuantity();
     85   llvm::APSInt TotalSize(llvm::APInt(SizeExtended.getBitWidth(), ElementSize));
     86   TotalSize *= SizeExtended;
     87 
     88   return TotalSize.getActiveBits();
     89 }
     90 
     91 unsigned ConstantArrayType::getMaxSizeBits(ASTContext &Context) {
     92   unsigned Bits = Context.getTypeSize(Context.getSizeType());
     93 
     94   // GCC appears to only allow 63 bits worth of address space when compiling
     95   // for 64-bit, so we do the same.
     96   if (Bits == 64)
     97     --Bits;
     98 
     99   return Bits;
    100 }
    101 
    102 DependentSizedArrayType::DependentSizedArrayType(const ASTContext &Context,
    103                                                  QualType et, QualType can,
    104                                                  Expr *e, ArraySizeModifier sm,
    105                                                  unsigned tq,
    106                                                  SourceRange brackets)
    107     : ArrayType(DependentSizedArray, et, can, sm, tq,
    108                 (et->containsUnexpandedParameterPack() ||
    109                  (e && e->containsUnexpandedParameterPack()))),
    110       Context(Context), SizeExpr((Stmt*) e), Brackets(brackets)
    111 {
    112 }
    113 
    114 void DependentSizedArrayType::Profile(llvm::FoldingSetNodeID &ID,
    115                                       const ASTContext &Context,
    116                                       QualType ET,
    117                                       ArraySizeModifier SizeMod,
    118                                       unsigned TypeQuals,
    119                                       Expr *E) {
    120   ID.AddPointer(ET.getAsOpaquePtr());
    121   ID.AddInteger(SizeMod);
    122   ID.AddInteger(TypeQuals);
    123   E->Profile(ID, Context, true);
    124 }
    125 
    126 DependentSizedExtVectorType::DependentSizedExtVectorType(const
    127                                                          ASTContext &Context,
    128                                                          QualType ElementType,
    129                                                          QualType can,
    130                                                          Expr *SizeExpr,
    131                                                          SourceLocation loc)
    132     : Type(DependentSizedExtVector, can, /*Dependent=*/true,
    133            /*InstantiationDependent=*/true,
    134            ElementType->isVariablyModifiedType(),
    135            (ElementType->containsUnexpandedParameterPack() ||
    136             (SizeExpr && SizeExpr->containsUnexpandedParameterPack()))),
    137       Context(Context), SizeExpr(SizeExpr), ElementType(ElementType),
    138       loc(loc)
    139 {
    140 }
    141 
    142 void
    143 DependentSizedExtVectorType::Profile(llvm::FoldingSetNodeID &ID,
    144                                      const ASTContext &Context,
    145                                      QualType ElementType, Expr *SizeExpr) {
    146   ID.AddPointer(ElementType.getAsOpaquePtr());
    147   SizeExpr->Profile(ID, Context, true);
    148 }
    149 
    150 VectorType::VectorType(QualType vecType, unsigned nElements, QualType canonType,
    151                        VectorKind vecKind)
    152   : Type(Vector, canonType, vecType->isDependentType(),
    153          vecType->isInstantiationDependentType(),
    154          vecType->isVariablyModifiedType(),
    155          vecType->containsUnexpandedParameterPack()),
    156     ElementType(vecType)
    157 {
    158   VectorTypeBits.VecKind = vecKind;
    159   VectorTypeBits.NumElements = nElements;
    160 }
    161 
    162 VectorType::VectorType(TypeClass tc, QualType vecType, unsigned nElements,
    163                        QualType canonType, VectorKind vecKind)
    164   : Type(tc, canonType, vecType->isDependentType(),
    165          vecType->isInstantiationDependentType(),
    166          vecType->isVariablyModifiedType(),
    167          vecType->containsUnexpandedParameterPack()),
    168     ElementType(vecType)
    169 {
    170   VectorTypeBits.VecKind = vecKind;
    171   VectorTypeBits.NumElements = nElements;
    172 }
    173 
    174 /// getArrayElementTypeNoTypeQual - If this is an array type, return the
    175 /// element type of the array, potentially with type qualifiers missing.
    176 /// This method should never be used when type qualifiers are meaningful.
    177 const Type *Type::getArrayElementTypeNoTypeQual() const {
    178   // If this is directly an array type, return it.
    179   if (const ArrayType *ATy = dyn_cast<ArrayType>(this))
    180     return ATy->getElementType().getTypePtr();
    181 
    182   // If the canonical form of this type isn't the right kind, reject it.
    183   if (!isa<ArrayType>(CanonicalType))
    184     return 0;
    185 
    186   // If this is a typedef for an array type, strip the typedef off without
    187   // losing all typedef information.
    188   return cast<ArrayType>(getUnqualifiedDesugaredType())
    189     ->getElementType().getTypePtr();
    190 }
    191 
    192 /// getDesugaredType - Return the specified type with any "sugar" removed from
    193 /// the type.  This takes off typedefs, typeof's etc.  If the outer level of
    194 /// the type is already concrete, it returns it unmodified.  This is similar
    195 /// to getting the canonical type, but it doesn't remove *all* typedefs.  For
    196 /// example, it returns "T*" as "T*", (not as "int*"), because the pointer is
    197 /// concrete.
    198 QualType QualType::getDesugaredType(QualType T, const ASTContext &Context) {
    199   SplitQualType split = getSplitDesugaredType(T);
    200   return Context.getQualifiedType(split.Ty, split.Quals);
    201 }
    202 
    203 QualType QualType::getSingleStepDesugaredTypeImpl(QualType type,
    204                                                   const ASTContext &Context) {
    205   SplitQualType split = type.split();
    206   QualType desugar = split.Ty->getLocallyUnqualifiedSingleStepDesugaredType();
    207   return Context.getQualifiedType(desugar, split.Quals);
    208 }
    209 
    210 QualType Type::getLocallyUnqualifiedSingleStepDesugaredType() const {
    211   switch (getTypeClass()) {
    212 #define ABSTRACT_TYPE(Class, Parent)
    213 #define TYPE(Class, Parent) \
    214   case Type::Class: { \
    215     const Class##Type *ty = cast<Class##Type>(this); \
    216     if (!ty->isSugared()) return QualType(ty, 0); \
    217     return ty->desugar(); \
    218   }
    219 #include "clang/AST/TypeNodes.def"
    220   }
    221   llvm_unreachable("bad type kind!");
    222 }
    223 
    224 SplitQualType QualType::getSplitDesugaredType(QualType T) {
    225   QualifierCollector Qs;
    226 
    227   QualType Cur = T;
    228   while (true) {
    229     const Type *CurTy = Qs.strip(Cur);
    230     switch (CurTy->getTypeClass()) {
    231 #define ABSTRACT_TYPE(Class, Parent)
    232 #define TYPE(Class, Parent) \
    233     case Type::Class: { \
    234       const Class##Type *Ty = cast<Class##Type>(CurTy); \
    235       if (!Ty->isSugared()) \
    236         return SplitQualType(Ty, Qs); \
    237       Cur = Ty->desugar(); \
    238       break; \
    239     }
    240 #include "clang/AST/TypeNodes.def"
    241     }
    242   }
    243 }
    244 
    245 SplitQualType QualType::getSplitUnqualifiedTypeImpl(QualType type) {
    246   SplitQualType split = type.split();
    247 
    248   // All the qualifiers we've seen so far.
    249   Qualifiers quals = split.Quals;
    250 
    251   // The last type node we saw with any nodes inside it.
    252   const Type *lastTypeWithQuals = split.Ty;
    253 
    254   while (true) {
    255     QualType next;
    256 
    257     // Do a single-step desugar, aborting the loop if the type isn't
    258     // sugared.
    259     switch (split.Ty->getTypeClass()) {
    260 #define ABSTRACT_TYPE(Class, Parent)
    261 #define TYPE(Class, Parent) \
    262     case Type::Class: { \
    263       const Class##Type *ty = cast<Class##Type>(split.Ty); \
    264       if (!ty->isSugared()) goto done; \
    265       next = ty->desugar(); \
    266       break; \
    267     }
    268 #include "clang/AST/TypeNodes.def"
    269     }
    270 
    271     // Otherwise, split the underlying type.  If that yields qualifiers,
    272     // update the information.
    273     split = next.split();
    274     if (!split.Quals.empty()) {
    275       lastTypeWithQuals = split.Ty;
    276       quals.addConsistentQualifiers(split.Quals);
    277     }
    278   }
    279 
    280  done:
    281   return SplitQualType(lastTypeWithQuals, quals);
    282 }
    283 
    284 QualType QualType::IgnoreParens(QualType T) {
    285   // FIXME: this seems inherently un-qualifiers-safe.
    286   while (const ParenType *PT = T->getAs<ParenType>())
    287     T = PT->getInnerType();
    288   return T;
    289 }
    290 
    291 /// getUnqualifiedDesugaredType - Pull any qualifiers and syntactic
    292 /// sugar off the given type.  This should produce an object of the
    293 /// same dynamic type as the canonical type.
    294 const Type *Type::getUnqualifiedDesugaredType() const {
    295   const Type *Cur = this;
    296 
    297   while (true) {
    298     switch (Cur->getTypeClass()) {
    299 #define ABSTRACT_TYPE(Class, Parent)
    300 #define TYPE(Class, Parent) \
    301     case Class: { \
    302       const Class##Type *Ty = cast<Class##Type>(Cur); \
    303       if (!Ty->isSugared()) return Cur; \
    304       Cur = Ty->desugar().getTypePtr(); \
    305       break; \
    306     }
    307 #include "clang/AST/TypeNodes.def"
    308     }
    309   }
    310 }
    311 
    312 bool Type::isDerivedType() const {
    313   switch (CanonicalType->getTypeClass()) {
    314   case Pointer:
    315   case VariableArray:
    316   case ConstantArray:
    317   case IncompleteArray:
    318   case FunctionProto:
    319   case FunctionNoProto:
    320   case LValueReference:
    321   case RValueReference:
    322   case Record:
    323     return true;
    324   default:
    325     return false;
    326   }
    327 }
    328 bool Type::isClassType() const {
    329   if (const RecordType *RT = getAs<RecordType>())
    330     return RT->getDecl()->isClass();
    331   return false;
    332 }
    333 bool Type::isStructureType() const {
    334   if (const RecordType *RT = getAs<RecordType>())
    335     return RT->getDecl()->isStruct();
    336   return false;
    337 }
    338 bool Type::isStructureOrClassType() const {
    339   if (const RecordType *RT = getAs<RecordType>())
    340     return RT->getDecl()->isStruct() || RT->getDecl()->isClass();
    341   return false;
    342 }
    343 bool Type::isVoidPointerType() const {
    344   if (const PointerType *PT = getAs<PointerType>())
    345     return PT->getPointeeType()->isVoidType();
    346   return false;
    347 }
    348 
    349 bool Type::isUnionType() const {
    350   if (const RecordType *RT = getAs<RecordType>())
    351     return RT->getDecl()->isUnion();
    352   return false;
    353 }
    354 
    355 bool Type::isComplexType() const {
    356   if (const ComplexType *CT = dyn_cast<ComplexType>(CanonicalType))
    357     return CT->getElementType()->isFloatingType();
    358   return false;
    359 }
    360 
    361 bool Type::isComplexIntegerType() const {
    362   // Check for GCC complex integer extension.
    363   return getAsComplexIntegerType();
    364 }
    365 
    366 const ComplexType *Type::getAsComplexIntegerType() const {
    367   if (const ComplexType *Complex = getAs<ComplexType>())
    368     if (Complex->getElementType()->isIntegerType())
    369       return Complex;
    370   return 0;
    371 }
    372 
    373 QualType Type::getPointeeType() const {
    374   if (const PointerType *PT = getAs<PointerType>())
    375     return PT->getPointeeType();
    376   if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>())
    377     return OPT->getPointeeType();
    378   if (const BlockPointerType *BPT = getAs<BlockPointerType>())
    379     return BPT->getPointeeType();
    380   if (const ReferenceType *RT = getAs<ReferenceType>())
    381     return RT->getPointeeType();
    382   return QualType();
    383 }
    384 
    385 const RecordType *Type::getAsStructureType() const {
    386   // If this is directly a structure type, return it.
    387   if (const RecordType *RT = dyn_cast<RecordType>(this)) {
    388     if (RT->getDecl()->isStruct())
    389       return RT;
    390   }
    391 
    392   // If the canonical form of this type isn't the right kind, reject it.
    393   if (const RecordType *RT = dyn_cast<RecordType>(CanonicalType)) {
    394     if (!RT->getDecl()->isStruct())
    395       return 0;
    396 
    397     // If this is a typedef for a structure type, strip the typedef off without
    398     // losing all typedef information.
    399     return cast<RecordType>(getUnqualifiedDesugaredType());
    400   }
    401   return 0;
    402 }
    403 
    404 const RecordType *Type::getAsUnionType() const {
    405   // If this is directly a union type, return it.
    406   if (const RecordType *RT = dyn_cast<RecordType>(this)) {
    407     if (RT->getDecl()->isUnion())
    408       return RT;
    409   }
    410 
    411   // If the canonical form of this type isn't the right kind, reject it.
    412   if (const RecordType *RT = dyn_cast<RecordType>(CanonicalType)) {
    413     if (!RT->getDecl()->isUnion())
    414       return 0;
    415 
    416     // If this is a typedef for a union type, strip the typedef off without
    417     // losing all typedef information.
    418     return cast<RecordType>(getUnqualifiedDesugaredType());
    419   }
    420 
    421   return 0;
    422 }
    423 
    424 ObjCObjectType::ObjCObjectType(QualType Canonical, QualType Base,
    425                                ObjCProtocolDecl * const *Protocols,
    426                                unsigned NumProtocols)
    427   : Type(ObjCObject, Canonical, false, false, false, false),
    428     BaseType(Base)
    429 {
    430   ObjCObjectTypeBits.NumProtocols = NumProtocols;
    431   assert(getNumProtocols() == NumProtocols &&
    432          "bitfield overflow in protocol count");
    433   if (NumProtocols)
    434     memcpy(getProtocolStorage(), Protocols,
    435            NumProtocols * sizeof(ObjCProtocolDecl*));
    436 }
    437 
    438 const ObjCObjectType *Type::getAsObjCQualifiedInterfaceType() const {
    439   // There is no sugar for ObjCObjectType's, just return the canonical
    440   // type pointer if it is the right class.  There is no typedef information to
    441   // return and these cannot be Address-space qualified.
    442   if (const ObjCObjectType *T = getAs<ObjCObjectType>())
    443     if (T->getNumProtocols() && T->getInterface())
    444       return T;
    445   return 0;
    446 }
    447 
    448 bool Type::isObjCQualifiedInterfaceType() const {
    449   return getAsObjCQualifiedInterfaceType() != 0;
    450 }
    451 
    452 const ObjCObjectPointerType *Type::getAsObjCQualifiedIdType() const {
    453   // There is no sugar for ObjCQualifiedIdType's, just return the canonical
    454   // type pointer if it is the right class.
    455   if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>()) {
    456     if (OPT->isObjCQualifiedIdType())
    457       return OPT;
    458   }
    459   return 0;
    460 }
    461 
    462 const ObjCObjectPointerType *Type::getAsObjCQualifiedClassType() const {
    463   // There is no sugar for ObjCQualifiedClassType's, just return the canonical
    464   // type pointer if it is the right class.
    465   if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>()) {
    466     if (OPT->isObjCQualifiedClassType())
    467       return OPT;
    468   }
    469   return 0;
    470 }
    471 
    472 const ObjCObjectPointerType *Type::getAsObjCInterfacePointerType() const {
    473   if (const ObjCObjectPointerType *OPT = getAs<ObjCObjectPointerType>()) {
    474     if (OPT->getInterfaceType())
    475       return OPT;
    476   }
    477   return 0;
    478 }
    479 
    480 const CXXRecordDecl *Type::getCXXRecordDeclForPointerType() const {
    481   if (const PointerType *PT = getAs<PointerType>())
    482     if (const RecordType *RT = PT->getPointeeType()->getAs<RecordType>())
    483       return dyn_cast<CXXRecordDecl>(RT->getDecl());
    484   return 0;
    485 }
    486 
    487 CXXRecordDecl *Type::getAsCXXRecordDecl() const {
    488   if (const RecordType *RT = getAs<RecordType>())
    489     return dyn_cast<CXXRecordDecl>(RT->getDecl());
    490   else if (const InjectedClassNameType *Injected
    491                                   = getAs<InjectedClassNameType>())
    492     return Injected->getDecl();
    493 
    494   return 0;
    495 }
    496 
    497 namespace {
    498   class GetContainedAutoVisitor :
    499     public TypeVisitor<GetContainedAutoVisitor, AutoType*> {
    500   public:
    501     using TypeVisitor<GetContainedAutoVisitor, AutoType*>::Visit;
    502     AutoType *Visit(QualType T) {
    503       if (T.isNull())
    504         return 0;
    505       return Visit(T.getTypePtr());
    506     }
    507 
    508     // The 'auto' type itself.
    509     AutoType *VisitAutoType(const AutoType *AT) {
    510       return const_cast<AutoType*>(AT);
    511     }
    512 
    513     // Only these types can contain the desired 'auto' type.
    514     AutoType *VisitPointerType(const PointerType *T) {
    515       return Visit(T->getPointeeType());
    516     }
    517     AutoType *VisitBlockPointerType(const BlockPointerType *T) {
    518       return Visit(T->getPointeeType());
    519     }
    520     AutoType *VisitReferenceType(const ReferenceType *T) {
    521       return Visit(T->getPointeeTypeAsWritten());
    522     }
    523     AutoType *VisitMemberPointerType(const MemberPointerType *T) {
    524       return Visit(T->getPointeeType());
    525     }
    526     AutoType *VisitArrayType(const ArrayType *T) {
    527       return Visit(T->getElementType());
    528     }
    529     AutoType *VisitDependentSizedExtVectorType(
    530       const DependentSizedExtVectorType *T) {
    531       return Visit(T->getElementType());
    532     }
    533     AutoType *VisitVectorType(const VectorType *T) {
    534       return Visit(T->getElementType());
    535     }
    536     AutoType *VisitFunctionType(const FunctionType *T) {
    537       return Visit(T->getResultType());
    538     }
    539     AutoType *VisitParenType(const ParenType *T) {
    540       return Visit(T->getInnerType());
    541     }
    542     AutoType *VisitAttributedType(const AttributedType *T) {
    543       return Visit(T->getModifiedType());
    544     }
    545   };
    546 }
    547 
    548 AutoType *Type::getContainedAutoType() const {
    549   return GetContainedAutoVisitor().Visit(this);
    550 }
    551 
    552 bool Type::hasIntegerRepresentation() const {
    553   if (const VectorType *VT = dyn_cast<VectorType>(CanonicalType))
    554     return VT->getElementType()->isIntegerType();
    555   else
    556     return isIntegerType();
    557 }
    558 
    559 /// \brief Determine whether this type is an integral type.
    560 ///
    561 /// This routine determines whether the given type is an integral type per
    562 /// C++ [basic.fundamental]p7. Although the C standard does not define the
    563 /// term "integral type", it has a similar term "integer type", and in C++
    564 /// the two terms are equivalent. However, C's "integer type" includes
    565 /// enumeration types, while C++'s "integer type" does not. The \c ASTContext
    566 /// parameter is used to determine whether we should be following the C or
    567 /// C++ rules when determining whether this type is an integral/integer type.
    568 ///
    569 /// For cases where C permits "an integer type" and C++ permits "an integral
    570 /// type", use this routine.
    571 ///
    572 /// For cases where C permits "an integer type" and C++ permits "an integral
    573 /// or enumeration type", use \c isIntegralOrEnumerationType() instead.
    574 ///
    575 /// \param Ctx The context in which this type occurs.
    576 ///
    577 /// \returns true if the type is considered an integral type, false otherwise.
    578 bool Type::isIntegralType(ASTContext &Ctx) const {
    579   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    580     return BT->getKind() >= BuiltinType::Bool &&
    581     BT->getKind() <= BuiltinType::Int128;
    582 
    583   if (!Ctx.getLangOpts().CPlusPlus)
    584     if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
    585       return ET->getDecl()->isComplete(); // Complete enum types are integral in C.
    586 
    587   return false;
    588 }
    589 
    590 
    591 bool Type::isIntegralOrUnscopedEnumerationType() const {
    592   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    593     return BT->getKind() >= BuiltinType::Bool &&
    594            BT->getKind() <= BuiltinType::Int128;
    595 
    596   // Check for a complete enum type; incomplete enum types are not properly an
    597   // enumeration type in the sense required here.
    598   // C++0x: However, if the underlying type of the enum is fixed, it is
    599   // considered complete.
    600   if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
    601     return ET->getDecl()->isComplete() && !ET->getDecl()->isScoped();
    602 
    603   return false;
    604 }
    605 
    606 
    607 
    608 bool Type::isCharType() const {
    609   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    610     return BT->getKind() == BuiltinType::Char_U ||
    611            BT->getKind() == BuiltinType::UChar ||
    612            BT->getKind() == BuiltinType::Char_S ||
    613            BT->getKind() == BuiltinType::SChar;
    614   return false;
    615 }
    616 
    617 bool Type::isWideCharType() const {
    618   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    619     return BT->getKind() == BuiltinType::WChar_S ||
    620            BT->getKind() == BuiltinType::WChar_U;
    621   return false;
    622 }
    623 
    624 bool Type::isChar16Type() const {
    625   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    626     return BT->getKind() == BuiltinType::Char16;
    627   return false;
    628 }
    629 
    630 bool Type::isChar32Type() const {
    631   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    632     return BT->getKind() == BuiltinType::Char32;
    633   return false;
    634 }
    635 
    636 /// \brief Determine whether this type is any of the built-in character
    637 /// types.
    638 bool Type::isAnyCharacterType() const {
    639   const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType);
    640   if (BT == 0) return false;
    641   switch (BT->getKind()) {
    642   default: return false;
    643   case BuiltinType::Char_U:
    644   case BuiltinType::UChar:
    645   case BuiltinType::WChar_U:
    646   case BuiltinType::Char16:
    647   case BuiltinType::Char32:
    648   case BuiltinType::Char_S:
    649   case BuiltinType::SChar:
    650   case BuiltinType::WChar_S:
    651     return true;
    652   }
    653 }
    654 
    655 /// isSignedIntegerType - Return true if this is an integer type that is
    656 /// signed, according to C99 6.2.5p4 [char, signed char, short, int, long..],
    657 /// an enum decl which has a signed representation
    658 bool Type::isSignedIntegerType() const {
    659   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType)) {
    660     return BT->getKind() >= BuiltinType::Char_S &&
    661            BT->getKind() <= BuiltinType::Int128;
    662   }
    663 
    664   if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
    665     // Incomplete enum types are not treated as integer types.
    666     // FIXME: In C++, enum types are never integer types.
    667     if (ET->getDecl()->isComplete() && !ET->getDecl()->isScoped())
    668       return ET->getDecl()->getIntegerType()->isSignedIntegerType();
    669   }
    670 
    671   return false;
    672 }
    673 
    674 bool Type::isSignedIntegerOrEnumerationType() const {
    675   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType)) {
    676     return BT->getKind() >= BuiltinType::Char_S &&
    677     BT->getKind() <= BuiltinType::Int128;
    678   }
    679 
    680   if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
    681     if (ET->getDecl()->isComplete())
    682       return ET->getDecl()->getIntegerType()->isSignedIntegerType();
    683   }
    684 
    685   return false;
    686 }
    687 
    688 bool Type::hasSignedIntegerRepresentation() const {
    689   if (const VectorType *VT = dyn_cast<VectorType>(CanonicalType))
    690     return VT->getElementType()->isSignedIntegerType();
    691   else
    692     return isSignedIntegerType();
    693 }
    694 
    695 /// isUnsignedIntegerType - Return true if this is an integer type that is
    696 /// unsigned, according to C99 6.2.5p6 [which returns true for _Bool], an enum
    697 /// decl which has an unsigned representation
    698 bool Type::isUnsignedIntegerType() const {
    699   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType)) {
    700     return BT->getKind() >= BuiltinType::Bool &&
    701            BT->getKind() <= BuiltinType::UInt128;
    702   }
    703 
    704   if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
    705     // Incomplete enum types are not treated as integer types.
    706     // FIXME: In C++, enum types are never integer types.
    707     if (ET->getDecl()->isComplete() && !ET->getDecl()->isScoped())
    708       return ET->getDecl()->getIntegerType()->isUnsignedIntegerType();
    709   }
    710 
    711   return false;
    712 }
    713 
    714 bool Type::isUnsignedIntegerOrEnumerationType() const {
    715   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType)) {
    716     return BT->getKind() >= BuiltinType::Bool &&
    717     BT->getKind() <= BuiltinType::UInt128;
    718   }
    719 
    720   if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
    721     if (ET->getDecl()->isComplete())
    722       return ET->getDecl()->getIntegerType()->isUnsignedIntegerType();
    723   }
    724 
    725   return false;
    726 }
    727 
    728 bool Type::hasUnsignedIntegerRepresentation() const {
    729   if (const VectorType *VT = dyn_cast<VectorType>(CanonicalType))
    730     return VT->getElementType()->isUnsignedIntegerType();
    731   else
    732     return isUnsignedIntegerType();
    733 }
    734 
    735 bool Type::isFloatingType() const {
    736   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    737     return BT->getKind() >= BuiltinType::Half &&
    738            BT->getKind() <= BuiltinType::LongDouble;
    739   if (const ComplexType *CT = dyn_cast<ComplexType>(CanonicalType))
    740     return CT->getElementType()->isFloatingType();
    741   return false;
    742 }
    743 
    744 bool Type::hasFloatingRepresentation() const {
    745   if (const VectorType *VT = dyn_cast<VectorType>(CanonicalType))
    746     return VT->getElementType()->isFloatingType();
    747   else
    748     return isFloatingType();
    749 }
    750 
    751 bool Type::isRealFloatingType() const {
    752   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    753     return BT->isFloatingPoint();
    754   return false;
    755 }
    756 
    757 bool Type::isRealType() const {
    758   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    759     return BT->getKind() >= BuiltinType::Bool &&
    760            BT->getKind() <= BuiltinType::LongDouble;
    761   if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
    762       return ET->getDecl()->isComplete() && !ET->getDecl()->isScoped();
    763   return false;
    764 }
    765 
    766 bool Type::isArithmeticType() const {
    767   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
    768     return BT->getKind() >= BuiltinType::Bool &&
    769            BT->getKind() <= BuiltinType::LongDouble;
    770   if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
    771     // GCC allows forward declaration of enum types (forbid by C99 6.7.2.3p2).
    772     // If a body isn't seen by the time we get here, return false.
    773     //
    774     // C++0x: Enumerations are not arithmetic types. For now, just return
    775     // false for scoped enumerations since that will disable any
    776     // unwanted implicit conversions.
    777     return !ET->getDecl()->isScoped() && ET->getDecl()->isComplete();
    778   return isa<ComplexType>(CanonicalType);
    779 }
    780 
    781 Type::ScalarTypeKind Type::getScalarTypeKind() const {
    782   assert(isScalarType());
    783 
    784   const Type *T = CanonicalType.getTypePtr();
    785   if (const BuiltinType *BT = dyn_cast<BuiltinType>(T)) {
    786     if (BT->getKind() == BuiltinType::Bool) return STK_Bool;
    787     if (BT->getKind() == BuiltinType::NullPtr) return STK_CPointer;
    788     if (BT->isInteger()) return STK_Integral;
    789     if (BT->isFloatingPoint()) return STK_Floating;
    790     llvm_unreachable("unknown scalar builtin type");
    791   } else if (isa<PointerType>(T)) {
    792     return STK_CPointer;
    793   } else if (isa<BlockPointerType>(T)) {
    794     return STK_BlockPointer;
    795   } else if (isa<ObjCObjectPointerType>(T)) {
    796     return STK_ObjCObjectPointer;
    797   } else if (isa<MemberPointerType>(T)) {
    798     return STK_MemberPointer;
    799   } else if (isa<EnumType>(T)) {
    800     assert(cast<EnumType>(T)->getDecl()->isComplete());
    801     return STK_Integral;
    802   } else if (const ComplexType *CT = dyn_cast<ComplexType>(T)) {
    803     if (CT->getElementType()->isRealFloatingType())
    804       return STK_FloatingComplex;
    805     return STK_IntegralComplex;
    806   }
    807 
    808   llvm_unreachable("unknown scalar type");
    809 }
    810 
    811 /// \brief Determines whether the type is a C++ aggregate type or C
    812 /// aggregate or union type.
    813 ///
    814 /// An aggregate type is an array or a class type (struct, union, or
    815 /// class) that has no user-declared constructors, no private or
    816 /// protected non-static data members, no base classes, and no virtual
    817 /// functions (C++ [dcl.init.aggr]p1). The notion of an aggregate type
    818 /// subsumes the notion of C aggregates (C99 6.2.5p21) because it also
    819 /// includes union types.
    820 bool Type::isAggregateType() const {
    821   if (const RecordType *Record = dyn_cast<RecordType>(CanonicalType)) {
    822     if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(Record->getDecl()))
    823       return ClassDecl->isAggregate();
    824 
    825     return true;
    826   }
    827 
    828   return isa<ArrayType>(CanonicalType);
    829 }
    830 
    831 /// isConstantSizeType - Return true if this is not a variable sized type,
    832 /// according to the rules of C99 6.7.5p3.  It is not legal to call this on
    833 /// incomplete types or dependent types.
    834 bool Type::isConstantSizeType() const {
    835   assert(!isIncompleteType() && "This doesn't make sense for incomplete types");
    836   assert(!isDependentType() && "This doesn't make sense for dependent types");
    837   // The VAT must have a size, as it is known to be complete.
    838   return !isa<VariableArrayType>(CanonicalType);
    839 }
    840 
    841 /// isIncompleteType - Return true if this is an incomplete type (C99 6.2.5p1)
    842 /// - a type that can describe objects, but which lacks information needed to
    843 /// determine its size.
    844 bool Type::isIncompleteType(NamedDecl **Def) const {
    845   if (Def)
    846     *Def = 0;
    847 
    848   switch (CanonicalType->getTypeClass()) {
    849   default: return false;
    850   case Builtin:
    851     // Void is the only incomplete builtin type.  Per C99 6.2.5p19, it can never
    852     // be completed.
    853     return isVoidType();
    854   case Enum: {
    855     EnumDecl *EnumD = cast<EnumType>(CanonicalType)->getDecl();
    856     if (Def)
    857       *Def = EnumD;
    858 
    859     // An enumeration with fixed underlying type is complete (C++0x 7.2p3).
    860     if (EnumD->isFixed())
    861       return false;
    862 
    863     return !EnumD->isCompleteDefinition();
    864   }
    865   case Record: {
    866     // A tagged type (struct/union/enum/class) is incomplete if the decl is a
    867     // forward declaration, but not a full definition (C99 6.2.5p22).
    868     RecordDecl *Rec = cast<RecordType>(CanonicalType)->getDecl();
    869     if (Def)
    870       *Def = Rec;
    871     return !Rec->isCompleteDefinition();
    872   }
    873   case ConstantArray:
    874     // An array is incomplete if its element type is incomplete
    875     // (C++ [dcl.array]p1).
    876     // We don't handle variable arrays (they're not allowed in C++) or
    877     // dependent-sized arrays (dependent types are never treated as incomplete).
    878     return cast<ArrayType>(CanonicalType)->getElementType()
    879              ->isIncompleteType(Def);
    880   case IncompleteArray:
    881     // An array of unknown size is an incomplete type (C99 6.2.5p22).
    882     return true;
    883   case ObjCObject:
    884     return cast<ObjCObjectType>(CanonicalType)->getBaseType()
    885              ->isIncompleteType(Def);
    886   case ObjCInterface: {
    887     // ObjC interfaces are incomplete if they are @class, not @interface.
    888     ObjCInterfaceDecl *Interface
    889       = cast<ObjCInterfaceType>(CanonicalType)->getDecl();
    890     if (Def)
    891       *Def = Interface;
    892     return !Interface->hasDefinition();
    893   }
    894   }
    895 }
    896 
    897 bool QualType::isPODType(ASTContext &Context) const {
    898   // The compiler shouldn't query this for incomplete types, but the user might.
    899   // We return false for that case. Except for incomplete arrays of PODs, which
    900   // are PODs according to the standard.
    901   if (isNull())
    902     return 0;
    903 
    904   if ((*this)->isIncompleteArrayType())
    905     return Context.getBaseElementType(*this).isPODType(Context);
    906 
    907   if ((*this)->isIncompleteType())
    908     return false;
    909 
    910   if (Context.getLangOpts().ObjCAutoRefCount) {
    911     switch (getObjCLifetime()) {
    912     case Qualifiers::OCL_ExplicitNone:
    913       return true;
    914 
    915     case Qualifiers::OCL_Strong:
    916     case Qualifiers::OCL_Weak:
    917     case Qualifiers::OCL_Autoreleasing:
    918       return false;
    919 
    920     case Qualifiers::OCL_None:
    921       break;
    922     }
    923   }
    924 
    925   QualType CanonicalType = getTypePtr()->CanonicalType;
    926   switch (CanonicalType->getTypeClass()) {
    927     // Everything not explicitly mentioned is not POD.
    928   default: return false;
    929   case Type::VariableArray:
    930   case Type::ConstantArray:
    931     // IncompleteArray is handled above.
    932     return Context.getBaseElementType(*this).isPODType(Context);
    933 
    934   case Type::ObjCObjectPointer:
    935   case Type::BlockPointer:
    936   case Type::Builtin:
    937   case Type::Complex:
    938   case Type::Pointer:
    939   case Type::MemberPointer:
    940   case Type::Vector:
    941   case Type::ExtVector:
    942     return true;
    943 
    944   case Type::Enum:
    945     return true;
    946 
    947   case Type::Record:
    948     if (CXXRecordDecl *ClassDecl
    949           = dyn_cast<CXXRecordDecl>(cast<RecordType>(CanonicalType)->getDecl()))
    950       return ClassDecl->isPOD();
    951 
    952     // C struct/union is POD.
    953     return true;
    954   }
    955 }
    956 
    957 bool QualType::isTrivialType(ASTContext &Context) const {
    958   // The compiler shouldn't query this for incomplete types, but the user might.
    959   // We return false for that case. Except for incomplete arrays of PODs, which
    960   // are PODs according to the standard.
    961   if (isNull())
    962     return 0;
    963 
    964   if ((*this)->isArrayType())
    965     return Context.getBaseElementType(*this).isTrivialType(Context);
    966 
    967   // Return false for incomplete types after skipping any incomplete array
    968   // types which are expressly allowed by the standard and thus our API.
    969   if ((*this)->isIncompleteType())
    970     return false;
    971 
    972   if (Context.getLangOpts().ObjCAutoRefCount) {
    973     switch (getObjCLifetime()) {
    974     case Qualifiers::OCL_ExplicitNone:
    975       return true;
    976 
    977     case Qualifiers::OCL_Strong:
    978     case Qualifiers::OCL_Weak:
    979     case Qualifiers::OCL_Autoreleasing:
    980       return false;
    981 
    982     case Qualifiers::OCL_None:
    983       if ((*this)->isObjCLifetimeType())
    984         return false;
    985       break;
    986     }
    987   }
    988 
    989   QualType CanonicalType = getTypePtr()->CanonicalType;
    990   if (CanonicalType->isDependentType())
    991     return false;
    992 
    993   // C++0x [basic.types]p9:
    994   //   Scalar types, trivial class types, arrays of such types, and
    995   //   cv-qualified versions of these types are collectively called trivial
    996   //   types.
    997 
    998   // As an extension, Clang treats vector types as Scalar types.
    999   if (CanonicalType->isScalarType() || CanonicalType->isVectorType())
   1000     return true;
   1001   if (const RecordType *RT = CanonicalType->getAs<RecordType>()) {
   1002     if (const CXXRecordDecl *ClassDecl =
   1003         dyn_cast<CXXRecordDecl>(RT->getDecl())) {
   1004       // C++0x [class]p5:
   1005       //   A trivial class is a class that has a trivial default constructor
   1006       if (!ClassDecl->hasTrivialDefaultConstructor()) return false;
   1007       //   and is trivially copyable.
   1008       if (!ClassDecl->isTriviallyCopyable()) return false;
   1009     }
   1010 
   1011     return true;
   1012   }
   1013 
   1014   // No other types can match.
   1015   return false;
   1016 }
   1017 
   1018 bool QualType::isTriviallyCopyableType(ASTContext &Context) const {
   1019   if ((*this)->isArrayType())
   1020     return Context.getBaseElementType(*this).isTrivialType(Context);
   1021 
   1022   if (Context.getLangOpts().ObjCAutoRefCount) {
   1023     switch (getObjCLifetime()) {
   1024     case Qualifiers::OCL_ExplicitNone:
   1025       return true;
   1026 
   1027     case Qualifiers::OCL_Strong:
   1028     case Qualifiers::OCL_Weak:
   1029     case Qualifiers::OCL_Autoreleasing:
   1030       return false;
   1031 
   1032     case Qualifiers::OCL_None:
   1033       if ((*this)->isObjCLifetimeType())
   1034         return false;
   1035       break;
   1036     }
   1037   }
   1038 
   1039   // C++0x [basic.types]p9
   1040   //   Scalar types, trivially copyable class types, arrays of such types, and
   1041   //   cv-qualified versions of these types are collectively called trivial
   1042   //   types.
   1043 
   1044   QualType CanonicalType = getCanonicalType();
   1045   if (CanonicalType->isDependentType())
   1046     return false;
   1047 
   1048   // Return false for incomplete types after skipping any incomplete array types
   1049   // which are expressly allowed by the standard and thus our API.
   1050   if (CanonicalType->isIncompleteType())
   1051     return false;
   1052 
   1053   // As an extension, Clang treats vector types as Scalar types.
   1054   if (CanonicalType->isScalarType() || CanonicalType->isVectorType())
   1055     return true;
   1056 
   1057   if (const RecordType *RT = CanonicalType->getAs<RecordType>()) {
   1058     if (const CXXRecordDecl *ClassDecl =
   1059           dyn_cast<CXXRecordDecl>(RT->getDecl())) {
   1060       if (!ClassDecl->isTriviallyCopyable()) return false;
   1061     }
   1062 
   1063     return true;
   1064   }
   1065 
   1066   // No other types can match.
   1067   return false;
   1068 }
   1069 
   1070 
   1071 
   1072 bool Type::isLiteralType() const {
   1073   if (isDependentType())
   1074     return false;
   1075 
   1076   // C++0x [basic.types]p10:
   1077   //   A type is a literal type if it is:
   1078   //   [...]
   1079   //   -- an array of literal type.
   1080   // Extension: variable arrays cannot be literal types, since they're
   1081   // runtime-sized.
   1082   if (isVariableArrayType())
   1083     return false;
   1084   const Type *BaseTy = getBaseElementTypeUnsafe();
   1085   assert(BaseTy && "NULL element type");
   1086 
   1087   // Return false for incomplete types after skipping any incomplete array
   1088   // types; those are expressly allowed by the standard and thus our API.
   1089   if (BaseTy->isIncompleteType())
   1090     return false;
   1091 
   1092   // C++0x [basic.types]p10:
   1093   //   A type is a literal type if it is:
   1094   //    -- a scalar type; or
   1095   // As an extension, Clang treats vector types and complex types as
   1096   // literal types.
   1097   if (BaseTy->isScalarType() || BaseTy->isVectorType() ||
   1098       BaseTy->isAnyComplexType())
   1099     return true;
   1100   //    -- a reference type; or
   1101   if (BaseTy->isReferenceType())
   1102     return true;
   1103   //    -- a class type that has all of the following properties:
   1104   if (const RecordType *RT = BaseTy->getAs<RecordType>()) {
   1105     //    -- a trivial destructor,
   1106     //    -- every constructor call and full-expression in the
   1107     //       brace-or-equal-initializers for non-static data members (if any)
   1108     //       is a constant expression,
   1109     //    -- it is an aggregate type or has at least one constexpr
   1110     //       constructor or constructor template that is not a copy or move
   1111     //       constructor, and
   1112     //    -- all non-static data members and base classes of literal types
   1113     //
   1114     // We resolve DR1361 by ignoring the second bullet.
   1115     if (const CXXRecordDecl *ClassDecl =
   1116         dyn_cast<CXXRecordDecl>(RT->getDecl()))
   1117       return ClassDecl->isLiteral();
   1118 
   1119     return true;
   1120   }
   1121 
   1122   return false;
   1123 }
   1124 
   1125 bool Type::isStandardLayoutType() const {
   1126   if (isDependentType())
   1127     return false;
   1128 
   1129   // C++0x [basic.types]p9:
   1130   //   Scalar types, standard-layout class types, arrays of such types, and
   1131   //   cv-qualified versions of these types are collectively called
   1132   //   standard-layout types.
   1133   const Type *BaseTy = getBaseElementTypeUnsafe();
   1134   assert(BaseTy && "NULL element type");
   1135 
   1136   // Return false for incomplete types after skipping any incomplete array
   1137   // types which are expressly allowed by the standard and thus our API.
   1138   if (BaseTy->isIncompleteType())
   1139     return false;
   1140 
   1141   // As an extension, Clang treats vector types as Scalar types.
   1142   if (BaseTy->isScalarType() || BaseTy->isVectorType()) return true;
   1143   if (const RecordType *RT = BaseTy->getAs<RecordType>()) {
   1144     if (const CXXRecordDecl *ClassDecl =
   1145         dyn_cast<CXXRecordDecl>(RT->getDecl()))
   1146       if (!ClassDecl->isStandardLayout())
   1147         return false;
   1148 
   1149     // Default to 'true' for non-C++ class types.
   1150     // FIXME: This is a bit dubious, but plain C structs should trivially meet
   1151     // all the requirements of standard layout classes.
   1152     return true;
   1153   }
   1154 
   1155   // No other types can match.
   1156   return false;
   1157 }
   1158 
   1159 // This is effectively the intersection of isTrivialType and
   1160 // isStandardLayoutType. We implement it directly to avoid redundant
   1161 // conversions from a type to a CXXRecordDecl.
   1162 bool QualType::isCXX11PODType(ASTContext &Context) const {
   1163   const Type *ty = getTypePtr();
   1164   if (ty->isDependentType())
   1165     return false;
   1166 
   1167   if (Context.getLangOpts().ObjCAutoRefCount) {
   1168     switch (getObjCLifetime()) {
   1169     case Qualifiers::OCL_ExplicitNone:
   1170       return true;
   1171 
   1172     case Qualifiers::OCL_Strong:
   1173     case Qualifiers::OCL_Weak:
   1174     case Qualifiers::OCL_Autoreleasing:
   1175       return false;
   1176 
   1177     case Qualifiers::OCL_None:
   1178       if (ty->isObjCLifetimeType())
   1179         return false;
   1180       break;
   1181     }
   1182   }
   1183 
   1184   // C++11 [basic.types]p9:
   1185   //   Scalar types, POD classes, arrays of such types, and cv-qualified
   1186   //   versions of these types are collectively called trivial types.
   1187   const Type *BaseTy = ty->getBaseElementTypeUnsafe();
   1188   assert(BaseTy && "NULL element type");
   1189 
   1190   // Return false for incomplete types after skipping any incomplete array
   1191   // types which are expressly allowed by the standard and thus our API.
   1192   if (BaseTy->isIncompleteType())
   1193     return false;
   1194 
   1195   // As an extension, Clang treats vector types as Scalar types.
   1196   if (BaseTy->isScalarType() || BaseTy->isVectorType()) return true;
   1197   if (const RecordType *RT = BaseTy->getAs<RecordType>()) {
   1198     if (const CXXRecordDecl *ClassDecl =
   1199         dyn_cast<CXXRecordDecl>(RT->getDecl())) {
   1200       // C++11 [class]p10:
   1201       //   A POD struct is a non-union class that is both a trivial class [...]
   1202       if (!ClassDecl->isTrivial()) return false;
   1203 
   1204       // C++11 [class]p10:
   1205       //   A POD struct is a non-union class that is both a trivial class and
   1206       //   a standard-layout class [...]
   1207       if (!ClassDecl->isStandardLayout()) return false;
   1208 
   1209       // C++11 [class]p10:
   1210       //   A POD struct is a non-union class that is both a trivial class and
   1211       //   a standard-layout class, and has no non-static data members of type
   1212       //   non-POD struct, non-POD union (or array of such types). [...]
   1213       //
   1214       // We don't directly query the recursive aspect as the requiremets for
   1215       // both standard-layout classes and trivial classes apply recursively
   1216       // already.
   1217     }
   1218 
   1219     return true;
   1220   }
   1221 
   1222   // No other types can match.
   1223   return false;
   1224 }
   1225 
   1226 bool Type::isPromotableIntegerType() const {
   1227   if (const BuiltinType *BT = getAs<BuiltinType>())
   1228     switch (BT->getKind()) {
   1229     case BuiltinType::Bool:
   1230     case BuiltinType::Char_S:
   1231     case BuiltinType::Char_U:
   1232     case BuiltinType::SChar:
   1233     case BuiltinType::UChar:
   1234     case BuiltinType::Short:
   1235     case BuiltinType::UShort:
   1236     case BuiltinType::WChar_S:
   1237     case BuiltinType::WChar_U:
   1238     case BuiltinType::Char16:
   1239     case BuiltinType::Char32:
   1240       return true;
   1241     default:
   1242       return false;
   1243     }
   1244 
   1245   // Enumerated types are promotable to their compatible integer types
   1246   // (C99 6.3.1.1) a.k.a. its underlying type (C++ [conv.prom]p2).
   1247   if (const EnumType *ET = getAs<EnumType>()){
   1248     if (this->isDependentType() || ET->getDecl()->getPromotionType().isNull()
   1249         || ET->getDecl()->isScoped())
   1250       return false;
   1251 
   1252     return true;
   1253   }
   1254 
   1255   return false;
   1256 }
   1257 
   1258 bool Type::isSpecifierType() const {
   1259   // Note that this intentionally does not use the canonical type.
   1260   switch (getTypeClass()) {
   1261   case Builtin:
   1262   case Record:
   1263   case Enum:
   1264   case Typedef:
   1265   case Complex:
   1266   case TypeOfExpr:
   1267   case TypeOf:
   1268   case TemplateTypeParm:
   1269   case SubstTemplateTypeParm:
   1270   case TemplateSpecialization:
   1271   case Elaborated:
   1272   case DependentName:
   1273   case DependentTemplateSpecialization:
   1274   case ObjCInterface:
   1275   case ObjCObject:
   1276   case ObjCObjectPointer: // FIXME: object pointers aren't really specifiers
   1277     return true;
   1278   default:
   1279     return false;
   1280   }
   1281 }
   1282 
   1283 ElaboratedTypeKeyword
   1284 TypeWithKeyword::getKeywordForTypeSpec(unsigned TypeSpec) {
   1285   switch (TypeSpec) {
   1286   default: return ETK_None;
   1287   case TST_typename: return ETK_Typename;
   1288   case TST_class: return ETK_Class;
   1289   case TST_struct: return ETK_Struct;
   1290   case TST_union: return ETK_Union;
   1291   case TST_enum: return ETK_Enum;
   1292   }
   1293 }
   1294 
   1295 TagTypeKind
   1296 TypeWithKeyword::getTagTypeKindForTypeSpec(unsigned TypeSpec) {
   1297   switch(TypeSpec) {
   1298   case TST_class: return TTK_Class;
   1299   case TST_struct: return TTK_Struct;
   1300   case TST_union: return TTK_Union;
   1301   case TST_enum: return TTK_Enum;
   1302   }
   1303 
   1304   llvm_unreachable("Type specifier is not a tag type kind.");
   1305 }
   1306 
   1307 ElaboratedTypeKeyword
   1308 TypeWithKeyword::getKeywordForTagTypeKind(TagTypeKind Kind) {
   1309   switch (Kind) {
   1310   case TTK_Class: return ETK_Class;
   1311   case TTK_Struct: return ETK_Struct;
   1312   case TTK_Union: return ETK_Union;
   1313   case TTK_Enum: return ETK_Enum;
   1314   }
   1315   llvm_unreachable("Unknown tag type kind.");
   1316 }
   1317 
   1318 TagTypeKind
   1319 TypeWithKeyword::getTagTypeKindForKeyword(ElaboratedTypeKeyword Keyword) {
   1320   switch (Keyword) {
   1321   case ETK_Class: return TTK_Class;
   1322   case ETK_Struct: return TTK_Struct;
   1323   case ETK_Union: return TTK_Union;
   1324   case ETK_Enum: return TTK_Enum;
   1325   case ETK_None: // Fall through.
   1326   case ETK_Typename:
   1327     llvm_unreachable("Elaborated type keyword is not a tag type kind.");
   1328   }
   1329   llvm_unreachable("Unknown elaborated type keyword.");
   1330 }
   1331 
   1332 bool
   1333 TypeWithKeyword::KeywordIsTagTypeKind(ElaboratedTypeKeyword Keyword) {
   1334   switch (Keyword) {
   1335   case ETK_None:
   1336   case ETK_Typename:
   1337     return false;
   1338   case ETK_Class:
   1339   case ETK_Struct:
   1340   case ETK_Union:
   1341   case ETK_Enum:
   1342     return true;
   1343   }
   1344   llvm_unreachable("Unknown elaborated type keyword.");
   1345 }
   1346 
   1347 const char*
   1348 TypeWithKeyword::getKeywordName(ElaboratedTypeKeyword Keyword) {
   1349   switch (Keyword) {
   1350   case ETK_None: return "";
   1351   case ETK_Typename: return "typename";
   1352   case ETK_Class:  return "class";
   1353   case ETK_Struct: return "struct";
   1354   case ETK_Union:  return "union";
   1355   case ETK_Enum:   return "enum";
   1356   }
   1357 
   1358   llvm_unreachable("Unknown elaborated type keyword.");
   1359 }
   1360 
   1361 DependentTemplateSpecializationType::DependentTemplateSpecializationType(
   1362                          ElaboratedTypeKeyword Keyword,
   1363                          NestedNameSpecifier *NNS, const IdentifierInfo *Name,
   1364                          unsigned NumArgs, const TemplateArgument *Args,
   1365                          QualType Canon)
   1366   : TypeWithKeyword(Keyword, DependentTemplateSpecialization, Canon, true, true,
   1367                     /*VariablyModified=*/false,
   1368                     NNS && NNS->containsUnexpandedParameterPack()),
   1369     NNS(NNS), Name(Name), NumArgs(NumArgs) {
   1370   assert((!NNS || NNS->isDependent()) &&
   1371          "DependentTemplateSpecializatonType requires dependent qualifier");
   1372   for (unsigned I = 0; I != NumArgs; ++I) {
   1373     if (Args[I].containsUnexpandedParameterPack())
   1374       setContainsUnexpandedParameterPack();
   1375 
   1376     new (&getArgBuffer()[I]) TemplateArgument(Args[I]);
   1377   }
   1378 }
   1379 
   1380 void
   1381 DependentTemplateSpecializationType::Profile(llvm::FoldingSetNodeID &ID,
   1382                                              const ASTContext &Context,
   1383                                              ElaboratedTypeKeyword Keyword,
   1384                                              NestedNameSpecifier *Qualifier,
   1385                                              const IdentifierInfo *Name,
   1386                                              unsigned NumArgs,
   1387                                              const TemplateArgument *Args) {
   1388   ID.AddInteger(Keyword);
   1389   ID.AddPointer(Qualifier);
   1390   ID.AddPointer(Name);
   1391   for (unsigned Idx = 0; Idx < NumArgs; ++Idx)
   1392     Args[Idx].Profile(ID, Context);
   1393 }
   1394 
   1395 bool Type::isElaboratedTypeSpecifier() const {
   1396   ElaboratedTypeKeyword Keyword;
   1397   if (const ElaboratedType *Elab = dyn_cast<ElaboratedType>(this))
   1398     Keyword = Elab->getKeyword();
   1399   else if (const DependentNameType *DepName = dyn_cast<DependentNameType>(this))
   1400     Keyword = DepName->getKeyword();
   1401   else if (const DependentTemplateSpecializationType *DepTST =
   1402              dyn_cast<DependentTemplateSpecializationType>(this))
   1403     Keyword = DepTST->getKeyword();
   1404   else
   1405     return false;
   1406 
   1407   return TypeWithKeyword::KeywordIsTagTypeKind(Keyword);
   1408 }
   1409 
   1410 const char *Type::getTypeClassName() const {
   1411   switch (TypeBits.TC) {
   1412 #define ABSTRACT_TYPE(Derived, Base)
   1413 #define TYPE(Derived, Base) case Derived: return #Derived;
   1414 #include "clang/AST/TypeNodes.def"
   1415   }
   1416 
   1417   llvm_unreachable("Invalid type class.");
   1418 }
   1419 
   1420 const char *BuiltinType::getName(const PrintingPolicy &Policy) const {
   1421   switch (getKind()) {
   1422   case Void:              return "void";
   1423   case Bool:              return Policy.Bool ? "bool" : "_Bool";
   1424   case Char_S:            return "char";
   1425   case Char_U:            return "char";
   1426   case SChar:             return "signed char";
   1427   case Short:             return "short";
   1428   case Int:               return "int";
   1429   case Long:              return "long";
   1430   case LongLong:          return "long long";
   1431   case Int128:            return "__int128";
   1432   case UChar:             return "unsigned char";
   1433   case UShort:            return "unsigned short";
   1434   case UInt:              return "unsigned int";
   1435   case ULong:             return "unsigned long";
   1436   case ULongLong:         return "unsigned long long";
   1437   case UInt128:           return "unsigned __int128";
   1438   case Half:              return "half";
   1439   case Float:             return "float";
   1440   case Double:            return "double";
   1441   case LongDouble:        return "long double";
   1442   case WChar_S:
   1443   case WChar_U:           return "wchar_t";
   1444   case Char16:            return "char16_t";
   1445   case Char32:            return "char32_t";
   1446   case NullPtr:           return "nullptr_t";
   1447   case Overload:          return "<overloaded function type>";
   1448   case BoundMember:       return "<bound member function type>";
   1449   case PseudoObject:      return "<pseudo-object type>";
   1450   case Dependent:         return "<dependent type>";
   1451   case UnknownAny:        return "<unknown type>";
   1452   case ARCUnbridgedCast:  return "<ARC unbridged cast type>";
   1453   case ObjCId:            return "id";
   1454   case ObjCClass:         return "Class";
   1455   case ObjCSel:           return "SEL";
   1456   }
   1457 
   1458   llvm_unreachable("Invalid builtin type.");
   1459 }
   1460 
   1461 QualType QualType::getNonLValueExprType(ASTContext &Context) const {
   1462   if (const ReferenceType *RefType = getTypePtr()->getAs<ReferenceType>())
   1463     return RefType->getPointeeType();
   1464 
   1465   // C++0x [basic.lval]:
   1466   //   Class prvalues can have cv-qualified types; non-class prvalues always
   1467   //   have cv-unqualified types.
   1468   //
   1469   // See also C99 6.3.2.1p2.
   1470   if (!Context.getLangOpts().CPlusPlus ||
   1471       (!getTypePtr()->isDependentType() && !getTypePtr()->isRecordType()))
   1472     return getUnqualifiedType();
   1473 
   1474   return *this;
   1475 }
   1476 
   1477 StringRef FunctionType::getNameForCallConv(CallingConv CC) {
   1478   switch (CC) {
   1479   case CC_Default:
   1480     llvm_unreachable("no name for default cc");
   1481 
   1482   case CC_C: return "cdecl";
   1483   case CC_X86StdCall: return "stdcall";
   1484   case CC_X86FastCall: return "fastcall";
   1485   case CC_X86ThisCall: return "thiscall";
   1486   case CC_X86Pascal: return "pascal";
   1487   case CC_AAPCS: return "aapcs";
   1488   case CC_AAPCS_VFP: return "aapcs-vfp";
   1489   }
   1490 
   1491   llvm_unreachable("Invalid calling convention.");
   1492 }
   1493 
   1494 FunctionProtoType::FunctionProtoType(QualType result, const QualType *args,
   1495                                      unsigned numArgs, QualType canonical,
   1496                                      const ExtProtoInfo &epi)
   1497   : FunctionType(FunctionProto, result, epi.TypeQuals, epi.RefQualifier,
   1498                  canonical,
   1499                  result->isDependentType(),
   1500                  result->isInstantiationDependentType(),
   1501                  result->isVariablyModifiedType(),
   1502                  result->containsUnexpandedParameterPack(),
   1503                  epi.ExtInfo),
   1504     NumArgs(numArgs), NumExceptions(epi.NumExceptions),
   1505     ExceptionSpecType(epi.ExceptionSpecType),
   1506     HasAnyConsumedArgs(epi.ConsumedArguments != 0),
   1507     Variadic(epi.Variadic), HasTrailingReturn(epi.HasTrailingReturn)
   1508 {
   1509   // Fill in the trailing argument array.
   1510   QualType *argSlot = reinterpret_cast<QualType*>(this+1);
   1511   for (unsigned i = 0; i != numArgs; ++i) {
   1512     if (args[i]->isDependentType())
   1513       setDependent();
   1514     else if (args[i]->isInstantiationDependentType())
   1515       setInstantiationDependent();
   1516 
   1517     if (args[i]->containsUnexpandedParameterPack())
   1518       setContainsUnexpandedParameterPack();
   1519 
   1520     argSlot[i] = args[i];
   1521   }
   1522 
   1523   if (getExceptionSpecType() == EST_Dynamic) {
   1524     // Fill in the exception array.
   1525     QualType *exnSlot = argSlot + numArgs;
   1526     for (unsigned i = 0, e = epi.NumExceptions; i != e; ++i) {
   1527       if (epi.Exceptions[i]->isDependentType())
   1528         setDependent();
   1529       else if (epi.Exceptions[i]->isInstantiationDependentType())
   1530         setInstantiationDependent();
   1531 
   1532       if (epi.Exceptions[i]->containsUnexpandedParameterPack())
   1533         setContainsUnexpandedParameterPack();
   1534 
   1535       exnSlot[i] = epi.Exceptions[i];
   1536     }
   1537   } else if (getExceptionSpecType() == EST_ComputedNoexcept) {
   1538     // Store the noexcept expression and context.
   1539     Expr **noexSlot = reinterpret_cast<Expr**>(argSlot + numArgs);
   1540     *noexSlot = epi.NoexceptExpr;
   1541 
   1542     if (epi.NoexceptExpr) {
   1543       if (epi.NoexceptExpr->isValueDependent()
   1544           || epi.NoexceptExpr->isTypeDependent())
   1545         setDependent();
   1546       else if (epi.NoexceptExpr->isInstantiationDependent())
   1547         setInstantiationDependent();
   1548     }
   1549   } else if (getExceptionSpecType() == EST_Uninstantiated) {
   1550     // Store the function decl from which we will resolve our
   1551     // exception specification.
   1552     FunctionDecl **slot = reinterpret_cast<FunctionDecl**>(argSlot + numArgs);
   1553     slot[0] = epi.ExceptionSpecDecl;
   1554     slot[1] = epi.ExceptionSpecTemplate;
   1555     // This exception specification doesn't make the type dependent, because
   1556     // it's not instantiated as part of instantiating the type.
   1557   }
   1558 
   1559   if (epi.ConsumedArguments) {
   1560     bool *consumedArgs = const_cast<bool*>(getConsumedArgsBuffer());
   1561     for (unsigned i = 0; i != numArgs; ++i)
   1562       consumedArgs[i] = epi.ConsumedArguments[i];
   1563   }
   1564 }
   1565 
   1566 FunctionProtoType::NoexceptResult
   1567 FunctionProtoType::getNoexceptSpec(ASTContext &ctx) const {
   1568   ExceptionSpecificationType est = getExceptionSpecType();
   1569   if (est == EST_BasicNoexcept)
   1570     return NR_Nothrow;
   1571 
   1572   if (est != EST_ComputedNoexcept)
   1573     return NR_NoNoexcept;
   1574 
   1575   Expr *noexceptExpr = getNoexceptExpr();
   1576   if (!noexceptExpr)
   1577     return NR_BadNoexcept;
   1578   if (noexceptExpr->isValueDependent())
   1579     return NR_Dependent;
   1580 
   1581   llvm::APSInt value;
   1582   bool isICE = noexceptExpr->isIntegerConstantExpr(value, ctx, 0,
   1583                                                    /*evaluated*/false);
   1584   (void)isICE;
   1585   assert(isICE && "AST should not contain bad noexcept expressions.");
   1586 
   1587   return value.getBoolValue() ? NR_Nothrow : NR_Throw;
   1588 }
   1589 
   1590 bool FunctionProtoType::isTemplateVariadic() const {
   1591   for (unsigned ArgIdx = getNumArgs(); ArgIdx; --ArgIdx)
   1592     if (isa<PackExpansionType>(getArgType(ArgIdx - 1)))
   1593       return true;
   1594 
   1595   return false;
   1596 }
   1597 
   1598 void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   1599                                 const QualType *ArgTys, unsigned NumArgs,
   1600                                 const ExtProtoInfo &epi,
   1601                                 const ASTContext &Context) {
   1602 
   1603   // We have to be careful not to get ambiguous profile encodings.
   1604   // Note that valid type pointers are never ambiguous with anything else.
   1605   //
   1606   // The encoding grammar begins:
   1607   //      type type* bool int bool
   1608   // If that final bool is true, then there is a section for the EH spec:
   1609   //      bool type*
   1610   // This is followed by an optional "consumed argument" section of the
   1611   // same length as the first type sequence:
   1612   //      bool*
   1613   // Finally, we have the ext info and trailing return type flag:
   1614   //      int bool
   1615   //
   1616   // There is no ambiguity between the consumed arguments and an empty EH
   1617   // spec because of the leading 'bool' which unambiguously indicates
   1618   // whether the following bool is the EH spec or part of the arguments.
   1619 
   1620   ID.AddPointer(Result.getAsOpaquePtr());
   1621   for (unsigned i = 0; i != NumArgs; ++i)
   1622     ID.AddPointer(ArgTys[i].getAsOpaquePtr());
   1623   // This method is relatively performance sensitive, so as a performance
   1624   // shortcut, use one AddInteger call instead of four for the next four
   1625   // fields.
   1626   assert(!(unsigned(epi.Variadic) & ~1) &&
   1627          !(unsigned(epi.TypeQuals) & ~255) &&
   1628          !(unsigned(epi.RefQualifier) & ~3) &&
   1629          !(unsigned(epi.ExceptionSpecType) & ~7) &&
   1630          "Values larger than expected.");
   1631   ID.AddInteger(unsigned(epi.Variadic) +
   1632                 (epi.TypeQuals << 1) +
   1633                 (epi.RefQualifier << 9) +
   1634                 (epi.ExceptionSpecType << 11));
   1635   if (epi.ExceptionSpecType == EST_Dynamic) {
   1636     for (unsigned i = 0; i != epi.NumExceptions; ++i)
   1637       ID.AddPointer(epi.Exceptions[i].getAsOpaquePtr());
   1638   } else if (epi.ExceptionSpecType == EST_ComputedNoexcept && epi.NoexceptExpr){
   1639     epi.NoexceptExpr->Profile(ID, Context, false);
   1640   } else if (epi.ExceptionSpecType == EST_Uninstantiated) {
   1641     ID.AddPointer(epi.ExceptionSpecDecl->getCanonicalDecl());
   1642   }
   1643   if (epi.ConsumedArguments) {
   1644     for (unsigned i = 0; i != NumArgs; ++i)
   1645       ID.AddBoolean(epi.ConsumedArguments[i]);
   1646   }
   1647   epi.ExtInfo.Profile(ID);
   1648   ID.AddBoolean(epi.HasTrailingReturn);
   1649 }
   1650 
   1651 void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID,
   1652                                 const ASTContext &Ctx) {
   1653   Profile(ID, getResultType(), arg_type_begin(), NumArgs, getExtProtoInfo(),
   1654           Ctx);
   1655 }
   1656 
   1657 QualType TypedefType::desugar() const {
   1658   return getDecl()->getUnderlyingType();
   1659 }
   1660 
   1661 TypeOfExprType::TypeOfExprType(Expr *E, QualType can)
   1662   : Type(TypeOfExpr, can, E->isTypeDependent(),
   1663          E->isInstantiationDependent(),
   1664          E->getType()->isVariablyModifiedType(),
   1665          E->containsUnexpandedParameterPack()),
   1666     TOExpr(E) {
   1667 }
   1668 
   1669 bool TypeOfExprType::isSugared() const {
   1670   return !TOExpr->isTypeDependent();
   1671 }
   1672 
   1673 QualType TypeOfExprType::desugar() const {
   1674   if (isSugared())
   1675     return getUnderlyingExpr()->getType();
   1676 
   1677   return QualType(this, 0);
   1678 }
   1679 
   1680 void DependentTypeOfExprType::Profile(llvm::FoldingSetNodeID &ID,
   1681                                       const ASTContext &Context, Expr *E) {
   1682   E->Profile(ID, Context, true);
   1683 }
   1684 
   1685 DecltypeType::DecltypeType(Expr *E, QualType underlyingType, QualType can)
   1686   // C++11 [temp.type]p2: "If an expression e involves a template parameter,
   1687   // decltype(e) denotes a unique dependent type." Hence a decltype type is
   1688   // type-dependent even if its expression is only instantiation-dependent.
   1689   : Type(Decltype, can, E->isInstantiationDependent(),
   1690          E->isInstantiationDependent(),
   1691          E->getType()->isVariablyModifiedType(),
   1692          E->containsUnexpandedParameterPack()),
   1693     E(E),
   1694   UnderlyingType(underlyingType) {
   1695 }
   1696 
   1697 bool DecltypeType::isSugared() const { return !E->isInstantiationDependent(); }
   1698 
   1699 QualType DecltypeType::desugar() const {
   1700   if (isSugared())
   1701     return getUnderlyingType();
   1702 
   1703   return QualType(this, 0);
   1704 }
   1705 
   1706 DependentDecltypeType::DependentDecltypeType(const ASTContext &Context, Expr *E)
   1707   : DecltypeType(E, Context.DependentTy), Context(Context) { }
   1708 
   1709 void DependentDecltypeType::Profile(llvm::FoldingSetNodeID &ID,
   1710                                     const ASTContext &Context, Expr *E) {
   1711   E->Profile(ID, Context, true);
   1712 }
   1713 
   1714 TagType::TagType(TypeClass TC, const TagDecl *D, QualType can)
   1715   : Type(TC, can, D->isDependentType(),
   1716          /*InstantiationDependent=*/D->isDependentType(),
   1717          /*VariablyModified=*/false,
   1718          /*ContainsUnexpandedParameterPack=*/false),
   1719     decl(const_cast<TagDecl*>(D)) {}
   1720 
   1721 static TagDecl *getInterestingTagDecl(TagDecl *decl) {
   1722   for (TagDecl::redecl_iterator I = decl->redecls_begin(),
   1723                                 E = decl->redecls_end();
   1724        I != E; ++I) {
   1725     if (I->isCompleteDefinition() || I->isBeingDefined())
   1726       return *I;
   1727   }
   1728   // If there's no definition (not even in progress), return what we have.
   1729   return decl;
   1730 }
   1731 
   1732 UnaryTransformType::UnaryTransformType(QualType BaseType,
   1733                                        QualType UnderlyingType,
   1734                                        UTTKind UKind,
   1735                                        QualType CanonicalType)
   1736   : Type(UnaryTransform, CanonicalType, UnderlyingType->isDependentType(),
   1737          UnderlyingType->isInstantiationDependentType(),
   1738          UnderlyingType->isVariablyModifiedType(),
   1739          BaseType->containsUnexpandedParameterPack())
   1740   , BaseType(BaseType), UnderlyingType(UnderlyingType), UKind(UKind)
   1741 {}
   1742 
   1743 TagDecl *TagType::getDecl() const {
   1744   return getInterestingTagDecl(decl);
   1745 }
   1746 
   1747 bool TagType::isBeingDefined() const {
   1748   return getDecl()->isBeingDefined();
   1749 }
   1750 
   1751 CXXRecordDecl *InjectedClassNameType::getDecl() const {
   1752   return cast<CXXRecordDecl>(getInterestingTagDecl(Decl));
   1753 }
   1754 
   1755 IdentifierInfo *TemplateTypeParmType::getIdentifier() const {
   1756   return isCanonicalUnqualified() ? 0 : getDecl()->getIdentifier();
   1757 }
   1758 
   1759 SubstTemplateTypeParmPackType::
   1760 SubstTemplateTypeParmPackType(const TemplateTypeParmType *Param,
   1761                               QualType Canon,
   1762                               const TemplateArgument &ArgPack)
   1763   : Type(SubstTemplateTypeParmPack, Canon, true, true, false, true),
   1764     Replaced(Param),
   1765     Arguments(ArgPack.pack_begin()), NumArguments(ArgPack.pack_size())
   1766 {
   1767 }
   1768 
   1769 TemplateArgument SubstTemplateTypeParmPackType::getArgumentPack() const {
   1770   return TemplateArgument(Arguments, NumArguments);
   1771 }
   1772 
   1773 void SubstTemplateTypeParmPackType::Profile(llvm::FoldingSetNodeID &ID) {
   1774   Profile(ID, getReplacedParameter(), getArgumentPack());
   1775 }
   1776 
   1777 void SubstTemplateTypeParmPackType::Profile(llvm::FoldingSetNodeID &ID,
   1778                                            const TemplateTypeParmType *Replaced,
   1779                                             const TemplateArgument &ArgPack) {
   1780   ID.AddPointer(Replaced);
   1781   ID.AddInteger(ArgPack.pack_size());
   1782   for (TemplateArgument::pack_iterator P = ArgPack.pack_begin(),
   1783                                     PEnd = ArgPack.pack_end();
   1784        P != PEnd; ++P)
   1785     ID.AddPointer(P->getAsType().getAsOpaquePtr());
   1786 }
   1787 
   1788 bool TemplateSpecializationType::
   1789 anyDependentTemplateArguments(const TemplateArgumentListInfo &Args,
   1790                               bool &InstantiationDependent) {
   1791   return anyDependentTemplateArguments(Args.getArgumentArray(), Args.size(),
   1792                                        InstantiationDependent);
   1793 }
   1794 
   1795 bool TemplateSpecializationType::
   1796 anyDependentTemplateArguments(const TemplateArgumentLoc *Args, unsigned N,
   1797                               bool &InstantiationDependent) {
   1798   for (unsigned i = 0; i != N; ++i) {
   1799     if (Args[i].getArgument().isDependent()) {
   1800       InstantiationDependent = true;
   1801       return true;
   1802     }
   1803 
   1804     if (Args[i].getArgument().isInstantiationDependent())
   1805       InstantiationDependent = true;
   1806   }
   1807   return false;
   1808 }
   1809 
   1810 bool TemplateSpecializationType::
   1811 anyDependentTemplateArguments(const TemplateArgument *Args, unsigned N,
   1812                               bool &InstantiationDependent) {
   1813   for (unsigned i = 0; i != N; ++i) {
   1814     if (Args[i].isDependent()) {
   1815       InstantiationDependent = true;
   1816       return true;
   1817     }
   1818 
   1819     if (Args[i].isInstantiationDependent())
   1820       InstantiationDependent = true;
   1821   }
   1822   return false;
   1823 }
   1824 
   1825 TemplateSpecializationType::
   1826 TemplateSpecializationType(TemplateName T,
   1827                            const TemplateArgument *Args, unsigned NumArgs,
   1828                            QualType Canon, QualType AliasedType)
   1829   : Type(TemplateSpecialization,
   1830          Canon.isNull()? QualType(this, 0) : Canon,
   1831          Canon.isNull()? T.isDependent() : Canon->isDependentType(),
   1832          Canon.isNull()? T.isDependent()
   1833                        : Canon->isInstantiationDependentType(),
   1834          false,
   1835          Canon.isNull()? T.containsUnexpandedParameterPack()
   1836                        : Canon->containsUnexpandedParameterPack()),
   1837     Template(T), NumArgs(NumArgs), TypeAlias(!AliasedType.isNull()) {
   1838   assert(!T.getAsDependentTemplateName() &&
   1839          "Use DependentTemplateSpecializationType for dependent template-name");
   1840   assert((T.getKind() == TemplateName::Template ||
   1841           T.getKind() == TemplateName::SubstTemplateTemplateParm ||
   1842           T.getKind() == TemplateName::SubstTemplateTemplateParmPack) &&
   1843          "Unexpected template name for TemplateSpecializationType");
   1844   bool InstantiationDependent;
   1845   (void)InstantiationDependent;
   1846   assert((!Canon.isNull() ||
   1847           T.isDependent() ||
   1848           anyDependentTemplateArguments(Args, NumArgs,
   1849                                         InstantiationDependent)) &&
   1850          "No canonical type for non-dependent class template specialization");
   1851 
   1852   TemplateArgument *TemplateArgs
   1853     = reinterpret_cast<TemplateArgument *>(this + 1);
   1854   for (unsigned Arg = 0; Arg < NumArgs; ++Arg) {
   1855     // Update dependent and variably-modified bits.
   1856     // If the canonical type exists and is non-dependent, the template
   1857     // specialization type can be non-dependent even if one of the type
   1858     // arguments is. Given:
   1859     //   template<typename T> using U = int;
   1860     // U<T> is always non-dependent, irrespective of the type T.
   1861     if (Canon.isNull() && Args[Arg].isDependent())
   1862       setDependent();
   1863     else if (Args[Arg].isInstantiationDependent())
   1864       setInstantiationDependent();
   1865 
   1866     if (Args[Arg].getKind() == TemplateArgument::Type &&
   1867         Args[Arg].getAsType()->isVariablyModifiedType())
   1868       setVariablyModified();
   1869     if (Canon.isNull() && Args[Arg].containsUnexpandedParameterPack())
   1870       setContainsUnexpandedParameterPack();
   1871 
   1872     new (&TemplateArgs[Arg]) TemplateArgument(Args[Arg]);
   1873   }
   1874 
   1875   // Store the aliased type if this is a type alias template specialization.
   1876   if (TypeAlias) {
   1877     TemplateArgument *Begin = reinterpret_cast<TemplateArgument *>(this + 1);
   1878     *reinterpret_cast<QualType*>(Begin + getNumArgs()) = AliasedType;
   1879   }
   1880 }
   1881 
   1882 void
   1883 TemplateSpecializationType::Profile(llvm::FoldingSetNodeID &ID,
   1884                                     TemplateName T,
   1885                                     const TemplateArgument *Args,
   1886                                     unsigned NumArgs,
   1887                                     const ASTContext &Context) {
   1888   T.Profile(ID);
   1889   for (unsigned Idx = 0; Idx < NumArgs; ++Idx)
   1890     Args[Idx].Profile(ID, Context);
   1891 }
   1892 
   1893 QualType
   1894 QualifierCollector::apply(const ASTContext &Context, QualType QT) const {
   1895   if (!hasNonFastQualifiers())
   1896     return QT.withFastQualifiers(getFastQualifiers());
   1897 
   1898   return Context.getQualifiedType(QT, *this);
   1899 }
   1900 
   1901 QualType
   1902 QualifierCollector::apply(const ASTContext &Context, const Type *T) const {
   1903   if (!hasNonFastQualifiers())
   1904     return QualType(T, getFastQualifiers());
   1905 
   1906   return Context.getQualifiedType(T, *this);
   1907 }
   1908 
   1909 void ObjCObjectTypeImpl::Profile(llvm::FoldingSetNodeID &ID,
   1910                                  QualType BaseType,
   1911                                  ObjCProtocolDecl * const *Protocols,
   1912                                  unsigned NumProtocols) {
   1913   ID.AddPointer(BaseType.getAsOpaquePtr());
   1914   for (unsigned i = 0; i != NumProtocols; i++)
   1915     ID.AddPointer(Protocols[i]);
   1916 }
   1917 
   1918 void ObjCObjectTypeImpl::Profile(llvm::FoldingSetNodeID &ID) {
   1919   Profile(ID, getBaseType(), qual_begin(), getNumProtocols());
   1920 }
   1921 
   1922 namespace {
   1923 
   1924 /// \brief The cached properties of a type.
   1925 class CachedProperties {
   1926   NamedDecl::LinkageInfo LV;
   1927   bool local;
   1928 
   1929 public:
   1930   CachedProperties(NamedDecl::LinkageInfo LV, bool local)
   1931     : LV(LV), local(local) {}
   1932 
   1933   Linkage getLinkage() const { return LV.linkage(); }
   1934   Visibility getVisibility() const { return LV.visibility(); }
   1935   bool isVisibilityExplicit() const { return LV.visibilityExplicit(); }
   1936   bool hasLocalOrUnnamedType() const { return local; }
   1937 
   1938   friend CachedProperties merge(CachedProperties L, CachedProperties R) {
   1939     NamedDecl::LinkageInfo MergedLV = L.LV;
   1940     MergedLV.merge(R.LV);
   1941     return CachedProperties(MergedLV,
   1942                          L.hasLocalOrUnnamedType() | R.hasLocalOrUnnamedType());
   1943   }
   1944 };
   1945 }
   1946 
   1947 static CachedProperties computeCachedProperties(const Type *T);
   1948 
   1949 namespace clang {
   1950 /// The type-property cache.  This is templated so as to be
   1951 /// instantiated at an internal type to prevent unnecessary symbol
   1952 /// leakage.
   1953 template <class Private> class TypePropertyCache {
   1954 public:
   1955   static CachedProperties get(QualType T) {
   1956     return get(T.getTypePtr());
   1957   }
   1958 
   1959   static CachedProperties get(const Type *T) {
   1960     ensure(T);
   1961     NamedDecl::LinkageInfo LV(T->TypeBits.getLinkage(),
   1962                               T->TypeBits.getVisibility(),
   1963                               T->TypeBits.isVisibilityExplicit());
   1964     return CachedProperties(LV, T->TypeBits.hasLocalOrUnnamedType());
   1965   }
   1966 
   1967   static void ensure(const Type *T) {
   1968     // If the cache is valid, we're okay.
   1969     if (T->TypeBits.isCacheValid()) return;
   1970 
   1971     // If this type is non-canonical, ask its canonical type for the
   1972     // relevant information.
   1973     if (!T->isCanonicalUnqualified()) {
   1974       const Type *CT = T->getCanonicalTypeInternal().getTypePtr();
   1975       ensure(CT);
   1976       T->TypeBits.CacheValidAndVisibility =
   1977         CT->TypeBits.CacheValidAndVisibility;
   1978       T->TypeBits.CachedExplicitVisibility =
   1979         CT->TypeBits.CachedExplicitVisibility;
   1980       T->TypeBits.CachedLinkage = CT->TypeBits.CachedLinkage;
   1981       T->TypeBits.CachedLocalOrUnnamed = CT->TypeBits.CachedLocalOrUnnamed;
   1982       return;
   1983     }
   1984 
   1985     // Compute the cached properties and then set the cache.
   1986     CachedProperties Result = computeCachedProperties(T);
   1987     T->TypeBits.CacheValidAndVisibility = Result.getVisibility() + 1U;
   1988     T->TypeBits.CachedExplicitVisibility = Result.isVisibilityExplicit();
   1989     assert(T->TypeBits.isCacheValid() &&
   1990            T->TypeBits.getVisibility() == Result.getVisibility());
   1991     T->TypeBits.CachedLinkage = Result.getLinkage();
   1992     T->TypeBits.CachedLocalOrUnnamed = Result.hasLocalOrUnnamedType();
   1993   }
   1994 };
   1995 }
   1996 
   1997 // Instantiate the friend template at a private class.  In a
   1998 // reasonable implementation, these symbols will be internal.
   1999 // It is terrible that this is the best way to accomplish this.
   2000 namespace { class Private {}; }
   2001 typedef TypePropertyCache<Private> Cache;
   2002 
   2003 static CachedProperties computeCachedProperties(const Type *T) {
   2004   switch (T->getTypeClass()) {
   2005 #define TYPE(Class,Base)
   2006 #define NON_CANONICAL_TYPE(Class,Base) case Type::Class:
   2007 #include "clang/AST/TypeNodes.def"
   2008     llvm_unreachable("didn't expect a non-canonical type here");
   2009 
   2010 #define TYPE(Class,Base)
   2011 #define DEPENDENT_TYPE(Class,Base) case Type::Class:
   2012 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class,Base) case Type::Class:
   2013 #include "clang/AST/TypeNodes.def"
   2014     // Treat instantiation-dependent types as external.
   2015     assert(T->isInstantiationDependentType());
   2016     return CachedProperties(NamedDecl::LinkageInfo(), false);
   2017 
   2018   case Type::Builtin:
   2019     // C++ [basic.link]p8:
   2020     //   A type is said to have linkage if and only if:
   2021     //     - it is a fundamental type (3.9.1); or
   2022     return CachedProperties(NamedDecl::LinkageInfo(), false);
   2023 
   2024   case Type::Record:
   2025   case Type::Enum: {
   2026     const TagDecl *Tag = cast<TagType>(T)->getDecl();
   2027 
   2028     // C++ [basic.link]p8:
   2029     //     - it is a class or enumeration type that is named (or has a name
   2030     //       for linkage purposes (7.1.3)) and the name has linkage; or
   2031     //     -  it is a specialization of a class template (14); or
   2032     NamedDecl::LinkageInfo LV = Tag->getLinkageAndVisibility();
   2033     bool IsLocalOrUnnamed =
   2034       Tag->getDeclContext()->isFunctionOrMethod() ||
   2035       (!Tag->getIdentifier() && !Tag->getTypedefNameForAnonDecl());
   2036     return CachedProperties(LV, IsLocalOrUnnamed);
   2037   }
   2038 
   2039     // C++ [basic.link]p8:
   2040     //   - it is a compound type (3.9.2) other than a class or enumeration,
   2041     //     compounded exclusively from types that have linkage; or
   2042   case Type::Complex:
   2043     return Cache::get(cast<ComplexType>(T)->getElementType());
   2044   case Type::Pointer:
   2045     return Cache::get(cast<PointerType>(T)->getPointeeType());
   2046   case Type::BlockPointer:
   2047     return Cache::get(cast<BlockPointerType>(T)->getPointeeType());
   2048   case Type::LValueReference:
   2049   case Type::RValueReference:
   2050     return Cache::get(cast<ReferenceType>(T)->getPointeeType());
   2051   case Type::MemberPointer: {
   2052     const MemberPointerType *MPT = cast<MemberPointerType>(T);
   2053     return merge(Cache::get(MPT->getClass()),
   2054                  Cache::get(MPT->getPointeeType()));
   2055   }
   2056   case Type::ConstantArray:
   2057   case Type::IncompleteArray:
   2058   case Type::VariableArray:
   2059     return Cache::get(cast<ArrayType>(T)->getElementType());
   2060   case Type::Vector:
   2061   case Type::ExtVector:
   2062     return Cache::get(cast<VectorType>(T)->getElementType());
   2063   case Type::FunctionNoProto:
   2064     return Cache::get(cast<FunctionType>(T)->getResultType());
   2065   case Type::FunctionProto: {
   2066     const FunctionProtoType *FPT = cast<FunctionProtoType>(T);
   2067     CachedProperties result = Cache::get(FPT->getResultType());
   2068     for (FunctionProtoType::arg_type_iterator ai = FPT->arg_type_begin(),
   2069            ae = FPT->arg_type_end(); ai != ae; ++ai)
   2070       result = merge(result, Cache::get(*ai));
   2071     return result;
   2072   }
   2073   case Type::ObjCInterface: {
   2074     NamedDecl::LinkageInfo LV =
   2075       cast<ObjCInterfaceType>(T)->getDecl()->getLinkageAndVisibility();
   2076     return CachedProperties(LV, false);
   2077   }
   2078   case Type::ObjCObject:
   2079     return Cache::get(cast<ObjCObjectType>(T)->getBaseType());
   2080   case Type::ObjCObjectPointer:
   2081     return Cache::get(cast<ObjCObjectPointerType>(T)->getPointeeType());
   2082   case Type::Atomic:
   2083     return Cache::get(cast<AtomicType>(T)->getValueType());
   2084   }
   2085 
   2086   llvm_unreachable("unhandled type class");
   2087 }
   2088 
   2089 /// \brief Determine the linkage of this type.
   2090 Linkage Type::getLinkage() const {
   2091   Cache::ensure(this);
   2092   return TypeBits.getLinkage();
   2093 }
   2094 
   2095 /// \brief Determine the linkage of this type.
   2096 Visibility Type::getVisibility() const {
   2097   Cache::ensure(this);
   2098   return TypeBits.getVisibility();
   2099 }
   2100 
   2101 bool Type::isVisibilityExplicit() const {
   2102   Cache::ensure(this);
   2103   return TypeBits.isVisibilityExplicit();
   2104 }
   2105 
   2106 bool Type::hasUnnamedOrLocalType() const {
   2107   Cache::ensure(this);
   2108   return TypeBits.hasLocalOrUnnamedType();
   2109 }
   2110 
   2111 std::pair<Linkage,Visibility> Type::getLinkageAndVisibility() const {
   2112   Cache::ensure(this);
   2113   return std::make_pair(TypeBits.getLinkage(), TypeBits.getVisibility());
   2114 }
   2115 
   2116 void Type::ClearLinkageCache() {
   2117   TypeBits.CacheValidAndVisibility = 0;
   2118   if (QualType(this, 0) != CanonicalType)
   2119     CanonicalType->TypeBits.CacheValidAndVisibility = 0;
   2120 }
   2121 
   2122 Qualifiers::ObjCLifetime Type::getObjCARCImplicitLifetime() const {
   2123   if (isObjCARCImplicitlyUnretainedType())
   2124     return Qualifiers::OCL_ExplicitNone;
   2125   return Qualifiers::OCL_Strong;
   2126 }
   2127 
   2128 bool Type::isObjCARCImplicitlyUnretainedType() const {
   2129   assert(isObjCLifetimeType() &&
   2130          "cannot query implicit lifetime for non-inferrable type");
   2131 
   2132   const Type *canon = getCanonicalTypeInternal().getTypePtr();
   2133 
   2134   // Walk down to the base type.  We don't care about qualifiers for this.
   2135   while (const ArrayType *array = dyn_cast<ArrayType>(canon))
   2136     canon = array->getElementType().getTypePtr();
   2137 
   2138   if (const ObjCObjectPointerType *opt
   2139         = dyn_cast<ObjCObjectPointerType>(canon)) {
   2140     // Class and Class<Protocol> don't require retension.
   2141     if (opt->getObjectType()->isObjCClass())
   2142       return true;
   2143   }
   2144 
   2145   return false;
   2146 }
   2147 
   2148 bool Type::isObjCNSObjectType() const {
   2149   if (const TypedefType *typedefType = dyn_cast<TypedefType>(this))
   2150     return typedefType->getDecl()->hasAttr<ObjCNSObjectAttr>();
   2151   return false;
   2152 }
   2153 bool Type::isObjCRetainableType() const {
   2154   return isObjCObjectPointerType() ||
   2155          isBlockPointerType() ||
   2156          isObjCNSObjectType();
   2157 }
   2158 bool Type::isObjCIndirectLifetimeType() const {
   2159   if (isObjCLifetimeType())
   2160     return true;
   2161   if (const PointerType *OPT = getAs<PointerType>())
   2162     return OPT->getPointeeType()->isObjCIndirectLifetimeType();
   2163   if (const ReferenceType *Ref = getAs<ReferenceType>())
   2164     return Ref->getPointeeType()->isObjCIndirectLifetimeType();
   2165   if (const MemberPointerType *MemPtr = getAs<MemberPointerType>())
   2166     return MemPtr->getPointeeType()->isObjCIndirectLifetimeType();
   2167   return false;
   2168 }
   2169 
   2170 /// Returns true if objects of this type have lifetime semantics under
   2171 /// ARC.
   2172 bool Type::isObjCLifetimeType() const {
   2173   const Type *type = this;
   2174   while (const ArrayType *array = type->getAsArrayTypeUnsafe())
   2175     type = array->getElementType().getTypePtr();
   2176   return type->isObjCRetainableType();
   2177 }
   2178 
   2179 /// \brief Determine whether the given type T is a "bridgable" Objective-C type,
   2180 /// which is either an Objective-C object pointer type or an
   2181 bool Type::isObjCARCBridgableType() const {
   2182   return isObjCObjectPointerType() || isBlockPointerType();
   2183 }
   2184 
   2185 /// \brief Determine whether the given type T is a "bridgeable" C type.
   2186 bool Type::isCARCBridgableType() const {
   2187   const PointerType *Pointer = getAs<PointerType>();
   2188   if (!Pointer)
   2189     return false;
   2190 
   2191   QualType Pointee = Pointer->getPointeeType();
   2192   return Pointee->isVoidType() || Pointee->isRecordType();
   2193 }
   2194 
   2195 bool Type::hasSizedVLAType() const {
   2196   if (!isVariablyModifiedType()) return false;
   2197 
   2198   if (const PointerType *ptr = getAs<PointerType>())
   2199     return ptr->getPointeeType()->hasSizedVLAType();
   2200   if (const ReferenceType *ref = getAs<ReferenceType>())
   2201     return ref->getPointeeType()->hasSizedVLAType();
   2202   if (const ArrayType *arr = getAsArrayTypeUnsafe()) {
   2203     if (isa<VariableArrayType>(arr) &&
   2204         cast<VariableArrayType>(arr)->getSizeExpr())
   2205       return true;
   2206 
   2207     return arr->getElementType()->hasSizedVLAType();
   2208   }
   2209 
   2210   return false;
   2211 }
   2212 
   2213 QualType::DestructionKind QualType::isDestructedTypeImpl(QualType type) {
   2214   switch (type.getObjCLifetime()) {
   2215   case Qualifiers::OCL_None:
   2216   case Qualifiers::OCL_ExplicitNone:
   2217   case Qualifiers::OCL_Autoreleasing:
   2218     break;
   2219 
   2220   case Qualifiers::OCL_Strong:
   2221     return DK_objc_strong_lifetime;
   2222   case Qualifiers::OCL_Weak:
   2223     return DK_objc_weak_lifetime;
   2224   }
   2225 
   2226   /// Currently, the only destruction kind we recognize is C++ objects
   2227   /// with non-trivial destructors.
   2228   const CXXRecordDecl *record =
   2229     type->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
   2230   if (record && record->hasDefinition() && !record->hasTrivialDestructor())
   2231     return DK_cxx_destructor;
   2232 
   2233   return DK_none;
   2234 }
   2235 
   2236 bool QualType::hasTrivialAssignment(ASTContext &Context, bool Copying) const {
   2237   switch (getObjCLifetime()) {
   2238   case Qualifiers::OCL_None:
   2239     break;
   2240 
   2241   case Qualifiers::OCL_ExplicitNone:
   2242     return true;
   2243 
   2244   case Qualifiers::OCL_Autoreleasing:
   2245   case Qualifiers::OCL_Strong:
   2246   case Qualifiers::OCL_Weak:
   2247     return !Context.getLangOpts().ObjCAutoRefCount;
   2248   }
   2249 
   2250   if (const CXXRecordDecl *Record
   2251             = getTypePtr()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl())
   2252     return Copying ? Record->hasTrivialCopyAssignment() :
   2253                      Record->hasTrivialMoveAssignment();
   2254 
   2255   return true;
   2256 }
   2257