ASTContext.cpp revision af0f4d0b2e38c810effc8b024ad2fb6604eec5d3 
1//===--- ASTContext.cpp - Context to hold long-lived AST nodes ------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements the ASTContext interface.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/CharUnits.h"
16#include "clang/AST/DeclCXX.h"
17#include "clang/AST/DeclObjC.h"
18#include "clang/AST/DeclTemplate.h"
19#include "clang/AST/TypeLoc.h"
20#include "clang/AST/Expr.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/ExternalASTSource.h"
23#include "clang/AST/ASTMutationListener.h"
24#include "clang/AST/RecordLayout.h"
25#include "clang/AST/Mangle.h"
26#include "clang/Basic/Builtins.h"
27#include "clang/Basic/SourceManager.h"
28#include "clang/Basic/TargetInfo.h"
29#include "llvm/ADT/SmallString.h"
30#include "llvm/ADT/StringExtras.h"
31#include "llvm/Support/MathExtras.h"
32#include "llvm/Support/raw_ostream.h"
33#include "llvm/Support/Capacity.h"
34#include "CXXABI.h"
35#include <map>
36
37using namespace clang;
38
39unsigned ASTContext::NumImplicitDefaultConstructors;
40unsigned ASTContext::NumImplicitDefaultConstructorsDeclared;
41unsigned ASTContext::NumImplicitCopyConstructors;
42unsigned ASTContext::NumImplicitCopyConstructorsDeclared;
43unsigned ASTContext::NumImplicitMoveConstructors;
44unsigned ASTContext::NumImplicitMoveConstructorsDeclared;
45unsigned ASTContext::NumImplicitCopyAssignmentOperators;
46unsigned ASTContext::NumImplicitCopyAssignmentOperatorsDeclared;
47unsigned ASTContext::NumImplicitMoveAssignmentOperators;
48unsigned ASTContext::NumImplicitMoveAssignmentOperatorsDeclared;
49unsigned ASTContext::NumImplicitDestructors;
50unsigned ASTContext::NumImplicitDestructorsDeclared;
51
52enum FloatingRank {
53  FloatRank, DoubleRank, LongDoubleRank
54};
55
56void
57ASTContext::CanonicalTemplateTemplateParm::Profile(llvm::FoldingSetNodeID &ID,
58                                               TemplateTemplateParmDecl *Parm) {
59  ID.AddInteger(Parm->getDepth());
60  ID.AddInteger(Parm->getPosition());
61  ID.AddBoolean(Parm->isParameterPack());
62
63  TemplateParameterList *Params = Parm->getTemplateParameters();
64  ID.AddInteger(Params->size());
65  for (TemplateParameterList::const_iterator P = Params->begin(),
66                                          PEnd = Params->end();
67       P != PEnd; ++P) {
68    if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*P)) {
69      ID.AddInteger(0);
70      ID.AddBoolean(TTP->isParameterPack());
71      continue;
72    }
73
74    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
75      ID.AddInteger(1);
76      ID.AddBoolean(NTTP->isParameterPack());
77      ID.AddPointer(NTTP->getType().getAsOpaquePtr());
78      if (NTTP->isExpandedParameterPack()) {
79        ID.AddBoolean(true);
80        ID.AddInteger(NTTP->getNumExpansionTypes());
81        for (unsigned I = 0, N = NTTP->getNumExpansionTypes(); I != N; ++I)
82          ID.AddPointer(NTTP->getExpansionType(I).getAsOpaquePtr());
83      } else
84        ID.AddBoolean(false);
85      continue;
86    }
87
88    TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*P);
89    ID.AddInteger(2);
90    Profile(ID, TTP);
91  }
92}
93
94TemplateTemplateParmDecl *
95ASTContext::getCanonicalTemplateTemplateParmDecl(
96                                          TemplateTemplateParmDecl *TTP) const {
97  // Check if we already have a canonical template template parameter.
98  llvm::FoldingSetNodeID ID;
99  CanonicalTemplateTemplateParm::Profile(ID, TTP);
100  void *InsertPos = 0;
101  CanonicalTemplateTemplateParm *Canonical
102    = CanonTemplateTemplateParms.FindNodeOrInsertPos(ID, InsertPos);
103  if (Canonical)
104    return Canonical->getParam();
105
106  // Build a canonical template parameter list.
107  TemplateParameterList *Params = TTP->getTemplateParameters();
108  SmallVector<NamedDecl *, 4> CanonParams;
109  CanonParams.reserve(Params->size());
110  for (TemplateParameterList::const_iterator P = Params->begin(),
111                                          PEnd = Params->end();
112       P != PEnd; ++P) {
113    if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*P))
114      CanonParams.push_back(
115                  TemplateTypeParmDecl::Create(*this, getTranslationUnitDecl(),
116                                               SourceLocation(),
117                                               SourceLocation(),
118                                               TTP->getDepth(),
119                                               TTP->getIndex(), 0, false,
120                                               TTP->isParameterPack()));
121    else if (NonTypeTemplateParmDecl *NTTP
122             = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
123      QualType T = getCanonicalType(NTTP->getType());
124      TypeSourceInfo *TInfo = getTrivialTypeSourceInfo(T);
125      NonTypeTemplateParmDecl *Param;
126      if (NTTP->isExpandedParameterPack()) {
127        SmallVector<QualType, 2> ExpandedTypes;
128        SmallVector<TypeSourceInfo *, 2> ExpandedTInfos;
129        for (unsigned I = 0, N = NTTP->getNumExpansionTypes(); I != N; ++I) {
130          ExpandedTypes.push_back(getCanonicalType(NTTP->getExpansionType(I)));
131          ExpandedTInfos.push_back(
132                                getTrivialTypeSourceInfo(ExpandedTypes.back()));
133        }
134
135        Param = NonTypeTemplateParmDecl::Create(*this, getTranslationUnitDecl(),
136                                                SourceLocation(),
137                                                SourceLocation(),
138                                                NTTP->getDepth(),
139                                                NTTP->getPosition(), 0,
140                                                T,
141                                                TInfo,
142                                                ExpandedTypes.data(),
143                                                ExpandedTypes.size(),
144                                                ExpandedTInfos.data());
145      } else {
146        Param = NonTypeTemplateParmDecl::Create(*this, getTranslationUnitDecl(),
147                                                SourceLocation(),
148                                                SourceLocation(),
149                                                NTTP->getDepth(),
150                                                NTTP->getPosition(), 0,
151                                                T,
152                                                NTTP->isParameterPack(),
153                                                TInfo);
154      }
155      CanonParams.push_back(Param);
156
157    } else
158      CanonParams.push_back(getCanonicalTemplateTemplateParmDecl(
159                                           cast<TemplateTemplateParmDecl>(*P)));
160  }
161
162  TemplateTemplateParmDecl *CanonTTP
163    = TemplateTemplateParmDecl::Create(*this, getTranslationUnitDecl(),
164                                       SourceLocation(), TTP->getDepth(),
165                                       TTP->getPosition(),
166                                       TTP->isParameterPack(),
167                                       0,
168                         TemplateParameterList::Create(*this, SourceLocation(),
169                                                       SourceLocation(),
170                                                       CanonParams.data(),
171                                                       CanonParams.size(),
172                                                       SourceLocation()));
173
174  // Get the new insert position for the node we care about.
175  Canonical = CanonTemplateTemplateParms.FindNodeOrInsertPos(ID, InsertPos);
176  assert(Canonical == 0 && "Shouldn't be in the map!");
177  (void)Canonical;
178
179  // Create the canonical template template parameter entry.
180  Canonical = new (*this) CanonicalTemplateTemplateParm(CanonTTP);
181  CanonTemplateTemplateParms.InsertNode(Canonical, InsertPos);
182  return CanonTTP;
183}
184
185CXXABI *ASTContext::createCXXABI(const TargetInfo &T) {
186  if (!LangOpts.CPlusPlus) return 0;
187
188  switch (T.getCXXABI()) {
189  case CXXABI_ARM:
190    return CreateARMCXXABI(*this);
191  case CXXABI_Itanium:
192    return CreateItaniumCXXABI(*this);
193  case CXXABI_Microsoft:
194    return CreateMicrosoftCXXABI(*this);
195  }
196  return 0;
197}
198
199static const LangAS::Map &getAddressSpaceMap(const TargetInfo &T,
200                                             const LangOptions &LOpts) {
201  if (LOpts.FakeAddressSpaceMap) {
202    // The fake address space map must have a distinct entry for each
203    // language-specific address space.
204    static const unsigned FakeAddrSpaceMap[] = {
205      1, // opencl_global
206      2, // opencl_local
207      3  // opencl_constant
208    };
209    return FakeAddrSpaceMap;
210  } else {
211    return T.getAddressSpaceMap();
212  }
213}
214
215ASTContext::ASTContext(const LangOptions& LOpts, SourceManager &SM,
216                       const TargetInfo &t,
217                       IdentifierTable &idents, SelectorTable &sels,
218                       Builtin::Context &builtins,
219                       unsigned size_reserve) :
220  FunctionProtoTypes(this_()),
221  TemplateSpecializationTypes(this_()),
222  DependentTemplateSpecializationTypes(this_()),
223  SubstTemplateTemplateParmPacks(this_()),
224  GlobalNestedNameSpecifier(0),
225  Int128Decl(0), UInt128Decl(0),
226  ObjCIdDecl(0), ObjCSelDecl(0), ObjCClassDecl(0),
227  CFConstantStringTypeDecl(0),
228  FILEDecl(0),
229  jmp_bufDecl(0), sigjmp_bufDecl(0), BlockDescriptorType(0),
230  BlockDescriptorExtendedType(0), cudaConfigureCallDecl(0),
231  NullTypeSourceInfo(QualType()),
232  SourceMgr(SM), LangOpts(LOpts), ABI(createCXXABI(t)),
233  AddrSpaceMap(getAddressSpaceMap(t, LOpts)), Target(t),
234  Idents(idents), Selectors(sels),
235  BuiltinInfo(builtins),
236  DeclarationNames(*this),
237  ExternalSource(0), Listener(0), PrintingPolicy(LOpts),
238  LastSDM(0, 0),
239  UniqueBlockByRefTypeID(0) {
240  if (size_reserve > 0) Types.reserve(size_reserve);
241  TUDecl = TranslationUnitDecl::Create(*this);
242  InitBuiltinTypes();
243}
244
245ASTContext::~ASTContext() {
246  // Release the DenseMaps associated with DeclContext objects.
247  // FIXME: Is this the ideal solution?
248  ReleaseDeclContextMaps();
249
250  // Call all of the deallocation functions.
251  for (unsigned I = 0, N = Deallocations.size(); I != N; ++I)
252    Deallocations[I].first(Deallocations[I].second);
253
254  // Release all of the memory associated with overridden C++ methods.
255  for (llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector>::iterator
256         OM = OverriddenMethods.begin(), OMEnd = OverriddenMethods.end();
257       OM != OMEnd; ++OM)
258    OM->second.Destroy();
259
260  // ASTRecordLayout objects in ASTRecordLayouts must always be destroyed
261  // because they can contain DenseMaps.
262  for (llvm::DenseMap<const ObjCContainerDecl*,
263       const ASTRecordLayout*>::iterator
264       I = ObjCLayouts.begin(), E = ObjCLayouts.end(); I != E; )
265    // Increment in loop to prevent using deallocated memory.
266    if (ASTRecordLayout *R = const_cast<ASTRecordLayout*>((I++)->second))
267      R->Destroy(*this);
268
269  for (llvm::DenseMap<const RecordDecl*, const ASTRecordLayout*>::iterator
270       I = ASTRecordLayouts.begin(), E = ASTRecordLayouts.end(); I != E; ) {
271    // Increment in loop to prevent using deallocated memory.
272    if (ASTRecordLayout *R = const_cast<ASTRecordLayout*>((I++)->second))
273      R->Destroy(*this);
274  }
275
276  for (llvm::DenseMap<const Decl*, AttrVec*>::iterator A = DeclAttrs.begin(),
277                                                    AEnd = DeclAttrs.end();
278       A != AEnd; ++A)
279    A->second->~AttrVec();
280}
281
282void ASTContext::AddDeallocation(void (*Callback)(void*), void *Data) {
283  Deallocations.push_back(std::make_pair(Callback, Data));
284}
285
286void
287ASTContext::setExternalSource(llvm::OwningPtr<ExternalASTSource> &Source) {
288  ExternalSource.reset(Source.take());
289}
290
291void ASTContext::PrintStats() const {
292  llvm::errs() << "\n*** AST Context Stats:\n";
293  llvm::errs() << "  " << Types.size() << " types total.\n";
294
295  unsigned counts[] = {
296#define TYPE(Name, Parent) 0,
297#define ABSTRACT_TYPE(Name, Parent)
298#include "clang/AST/TypeNodes.def"
299    0 // Extra
300  };
301
302  for (unsigned i = 0, e = Types.size(); i != e; ++i) {
303    Type *T = Types[i];
304    counts[(unsigned)T->getTypeClass()]++;
305  }
306
307  unsigned Idx = 0;
308  unsigned TotalBytes = 0;
309#define TYPE(Name, Parent)                                              \
310  if (counts[Idx])                                                      \
311    llvm::errs() << "    " << counts[Idx] << " " << #Name               \
312                 << " types\n";                                         \
313  TotalBytes += counts[Idx] * sizeof(Name##Type);                       \
314  ++Idx;
315#define ABSTRACT_TYPE(Name, Parent)
316#include "clang/AST/TypeNodes.def"
317
318  llvm::errs() << "Total bytes = " << TotalBytes << "\n";
319
320  // Implicit special member functions.
321  llvm::errs() << NumImplicitDefaultConstructorsDeclared << "/"
322               << NumImplicitDefaultConstructors
323               << " implicit default constructors created\n";
324  llvm::errs() << NumImplicitCopyConstructorsDeclared << "/"
325               << NumImplicitCopyConstructors
326               << " implicit copy constructors created\n";
327  if (getLangOptions().CPlusPlus)
328    llvm::errs() << NumImplicitMoveConstructorsDeclared << "/"
329                 << NumImplicitMoveConstructors
330                 << " implicit move constructors created\n";
331  llvm::errs() << NumImplicitCopyAssignmentOperatorsDeclared << "/"
332               << NumImplicitCopyAssignmentOperators
333               << " implicit copy assignment operators created\n";
334  if (getLangOptions().CPlusPlus)
335    llvm::errs() << NumImplicitMoveAssignmentOperatorsDeclared << "/"
336                 << NumImplicitMoveAssignmentOperators
337                 << " implicit move assignment operators created\n";
338  llvm::errs() << NumImplicitDestructorsDeclared << "/"
339               << NumImplicitDestructors
340               << " implicit destructors created\n";
341
342  if (ExternalSource.get()) {
343    llvm::errs() << "\n";
344    ExternalSource->PrintStats();
345  }
346
347  BumpAlloc.PrintStats();
348}
349
350TypedefDecl *ASTContext::getInt128Decl() const {
351  if (!Int128Decl) {
352    TypeSourceInfo *TInfo = getTrivialTypeSourceInfo(Int128Ty);
353    Int128Decl = TypedefDecl::Create(const_cast<ASTContext &>(*this),
354                                     getTranslationUnitDecl(),
355                                     SourceLocation(),
356                                     SourceLocation(),
357                                     &Idents.get("__int128_t"),
358                                     TInfo);
359  }
360
361  return Int128Decl;
362}
363
364TypedefDecl *ASTContext::getUInt128Decl() const {
365  if (!UInt128Decl) {
366    TypeSourceInfo *TInfo = getTrivialTypeSourceInfo(UnsignedInt128Ty);
367    UInt128Decl = TypedefDecl::Create(const_cast<ASTContext &>(*this),
368                                     getTranslationUnitDecl(),
369                                     SourceLocation(),
370                                     SourceLocation(),
371                                     &Idents.get("__uint128_t"),
372                                     TInfo);
373  }
374
375  return UInt128Decl;
376}
377
378void ASTContext::InitBuiltinType(CanQualType &R, BuiltinType::Kind K) {
379  BuiltinType *Ty = new (*this, TypeAlignment) BuiltinType(K);
380  R = CanQualType::CreateUnsafe(QualType(Ty, 0));
381  Types.push_back(Ty);
382}
383
384void ASTContext::InitBuiltinTypes() {
385  assert(VoidTy.isNull() && "Context reinitialized?");
386
387  // C99 6.2.5p19.
388  InitBuiltinType(VoidTy,              BuiltinType::Void);
389
390  // C99 6.2.5p2.
391  InitBuiltinType(BoolTy,              BuiltinType::Bool);
392  // C99 6.2.5p3.
393  if (LangOpts.CharIsSigned)
394    InitBuiltinType(CharTy,            BuiltinType::Char_S);
395  else
396    InitBuiltinType(CharTy,            BuiltinType::Char_U);
397  // C99 6.2.5p4.
398  InitBuiltinType(SignedCharTy,        BuiltinType::SChar);
399  InitBuiltinType(ShortTy,             BuiltinType::Short);
400  InitBuiltinType(IntTy,               BuiltinType::Int);
401  InitBuiltinType(LongTy,              BuiltinType::Long);
402  InitBuiltinType(LongLongTy,          BuiltinType::LongLong);
403
404  // C99 6.2.5p6.
405  InitBuiltinType(UnsignedCharTy,      BuiltinType::UChar);
406  InitBuiltinType(UnsignedShortTy,     BuiltinType::UShort);
407  InitBuiltinType(UnsignedIntTy,       BuiltinType::UInt);
408  InitBuiltinType(UnsignedLongTy,      BuiltinType::ULong);
409  InitBuiltinType(UnsignedLongLongTy,  BuiltinType::ULongLong);
410
411  // C99 6.2.5p10.
412  InitBuiltinType(FloatTy,             BuiltinType::Float);
413  InitBuiltinType(DoubleTy,            BuiltinType::Double);
414  InitBuiltinType(LongDoubleTy,        BuiltinType::LongDouble);
415
416  // GNU extension, 128-bit integers.
417  InitBuiltinType(Int128Ty,            BuiltinType::Int128);
418  InitBuiltinType(UnsignedInt128Ty,    BuiltinType::UInt128);
419
420  if (LangOpts.CPlusPlus) { // C++ 3.9.1p5
421    if (TargetInfo::isTypeSigned(Target.getWCharType()))
422      InitBuiltinType(WCharTy,           BuiltinType::WChar_S);
423    else  // -fshort-wchar makes wchar_t be unsigned.
424      InitBuiltinType(WCharTy,           BuiltinType::WChar_U);
425  } else // C99
426    WCharTy = getFromTargetType(Target.getWCharType());
427
428  if (LangOpts.CPlusPlus) // C++0x 3.9.1p5, extension for C++
429    InitBuiltinType(Char16Ty,           BuiltinType::Char16);
430  else // C99
431    Char16Ty = getFromTargetType(Target.getChar16Type());
432
433  if (LangOpts.CPlusPlus) // C++0x 3.9.1p5, extension for C++
434    InitBuiltinType(Char32Ty,           BuiltinType::Char32);
435  else // C99
436    Char32Ty = getFromTargetType(Target.getChar32Type());
437
438  // Placeholder type for type-dependent expressions whose type is
439  // completely unknown. No code should ever check a type against
440  // DependentTy and users should never see it; however, it is here to
441  // help diagnose failures to properly check for type-dependent
442  // expressions.
443  InitBuiltinType(DependentTy,         BuiltinType::Dependent);
444
445  // Placeholder type for functions.
446  InitBuiltinType(OverloadTy,          BuiltinType::Overload);
447
448  // Placeholder type for bound members.
449  InitBuiltinType(BoundMemberTy,       BuiltinType::BoundMember);
450
451  // "any" type; useful for debugger-like clients.
452  InitBuiltinType(UnknownAnyTy,        BuiltinType::UnknownAny);
453
454  // C99 6.2.5p11.
455  FloatComplexTy      = getComplexType(FloatTy);
456  DoubleComplexTy     = getComplexType(DoubleTy);
457  LongDoubleComplexTy = getComplexType(LongDoubleTy);
458
459  BuiltinVaListType = QualType();
460
461  // Builtin types for 'id', 'Class', and 'SEL'.
462  InitBuiltinType(ObjCBuiltinIdTy, BuiltinType::ObjCId);
463  InitBuiltinType(ObjCBuiltinClassTy, BuiltinType::ObjCClass);
464  InitBuiltinType(ObjCBuiltinSelTy, BuiltinType::ObjCSel);
465
466  ObjCConstantStringType = QualType();
467
468  // void * type
469  VoidPtrTy = getPointerType(VoidTy);
470
471  // nullptr type (C++0x 2.14.7)
472  InitBuiltinType(NullPtrTy,           BuiltinType::NullPtr);
473}
474
475Diagnostic &ASTContext::getDiagnostics() const {
476  return SourceMgr.getDiagnostics();
477}
478
479AttrVec& ASTContext::getDeclAttrs(const Decl *D) {
480  AttrVec *&Result = DeclAttrs[D];
481  if (!Result) {
482    void *Mem = Allocate(sizeof(AttrVec));
483    Result = new (Mem) AttrVec;
484  }
485
486  return *Result;
487}
488
489/// \brief Erase the attributes corresponding to the given declaration.
490void ASTContext::eraseDeclAttrs(const Decl *D) {
491  llvm::DenseMap<const Decl*, AttrVec*>::iterator Pos = DeclAttrs.find(D);
492  if (Pos != DeclAttrs.end()) {
493    Pos->second->~AttrVec();
494    DeclAttrs.erase(Pos);
495  }
496}
497
498MemberSpecializationInfo *
499ASTContext::getInstantiatedFromStaticDataMember(const VarDecl *Var) {
500  assert(Var->isStaticDataMember() && "Not a static data member");
501  llvm::DenseMap<const VarDecl *, MemberSpecializationInfo *>::iterator Pos
502    = InstantiatedFromStaticDataMember.find(Var);
503  if (Pos == InstantiatedFromStaticDataMember.end())
504    return 0;
505
506  return Pos->second;
507}
508
509void
510ASTContext::setInstantiatedFromStaticDataMember(VarDecl *Inst, VarDecl *Tmpl,
511                                                TemplateSpecializationKind TSK,
512                                          SourceLocation PointOfInstantiation) {
513  assert(Inst->isStaticDataMember() && "Not a static data member");
514  assert(Tmpl->isStaticDataMember() && "Not a static data member");
515  assert(!InstantiatedFromStaticDataMember[Inst] &&
516         "Already noted what static data member was instantiated from");
517  InstantiatedFromStaticDataMember[Inst]
518    = new (*this) MemberSpecializationInfo(Tmpl, TSK, PointOfInstantiation);
519}
520
521FunctionDecl *ASTContext::getClassScopeSpecializationPattern(
522                                                     const FunctionDecl *FD){
523  assert(FD && "Specialization is 0");
524  llvm::DenseMap<const FunctionDecl*, FunctionDecl *>::const_iterator Pos
525    = ClassScopeSpecilizationPattern.find(FD);
526  if (Pos == ClassScopeSpecilizationPattern.end())
527    return 0;
528
529  return Pos->second;
530}
531
532void ASTContext::setClassScopeSpecializationPattern(FunctionDecl *FD,
533                                        FunctionDecl *Pattern) {
534  assert(FD && "Specialization is 0");
535  assert(Pattern && "Class scope specialization pattern is 0");
536  ClassScopeSpecilizationPattern[FD] = Pattern;
537}
538
539NamedDecl *
540ASTContext::getInstantiatedFromUsingDecl(UsingDecl *UUD) {
541  llvm::DenseMap<UsingDecl *, NamedDecl *>::const_iterator Pos
542    = InstantiatedFromUsingDecl.find(UUD);
543  if (Pos == InstantiatedFromUsingDecl.end())
544    return 0;
545
546  return Pos->second;
547}
548
549void
550ASTContext::setInstantiatedFromUsingDecl(UsingDecl *Inst, NamedDecl *Pattern) {
551  assert((isa<UsingDecl>(Pattern) ||
552          isa<UnresolvedUsingValueDecl>(Pattern) ||
553          isa<UnresolvedUsingTypenameDecl>(Pattern)) &&
554         "pattern decl is not a using decl");
555  assert(!InstantiatedFromUsingDecl[Inst] && "pattern already exists");
556  InstantiatedFromUsingDecl[Inst] = Pattern;
557}
558
559UsingShadowDecl *
560ASTContext::getInstantiatedFromUsingShadowDecl(UsingShadowDecl *Inst) {
561  llvm::DenseMap<UsingShadowDecl*, UsingShadowDecl*>::const_iterator Pos
562    = InstantiatedFromUsingShadowDecl.find(Inst);
563  if (Pos == InstantiatedFromUsingShadowDecl.end())
564    return 0;
565
566  return Pos->second;
567}
568
569void
570ASTContext::setInstantiatedFromUsingShadowDecl(UsingShadowDecl *Inst,
571                                               UsingShadowDecl *Pattern) {
572  assert(!InstantiatedFromUsingShadowDecl[Inst] && "pattern already exists");
573  InstantiatedFromUsingShadowDecl[Inst] = Pattern;
574}
575
576FieldDecl *ASTContext::getInstantiatedFromUnnamedFieldDecl(FieldDecl *Field) {
577  llvm::DenseMap<FieldDecl *, FieldDecl *>::iterator Pos
578    = InstantiatedFromUnnamedFieldDecl.find(Field);
579  if (Pos == InstantiatedFromUnnamedFieldDecl.end())
580    return 0;
581
582  return Pos->second;
583}
584
585void ASTContext::setInstantiatedFromUnnamedFieldDecl(FieldDecl *Inst,
586                                                     FieldDecl *Tmpl) {
587  assert(!Inst->getDeclName() && "Instantiated field decl is not unnamed");
588  assert(!Tmpl->getDeclName() && "Template field decl is not unnamed");
589  assert(!InstantiatedFromUnnamedFieldDecl[Inst] &&
590         "Already noted what unnamed field was instantiated from");
591
592  InstantiatedFromUnnamedFieldDecl[Inst] = Tmpl;
593}
594
595bool ASTContext::ZeroBitfieldFollowsNonBitfield(const FieldDecl *FD,
596                                    const FieldDecl *LastFD) const {
597  return (FD->isBitField() && LastFD && !LastFD->isBitField() &&
598          FD->getBitWidth()->EvaluateAsInt(*this).getZExtValue() == 0);
599}
600
601bool ASTContext::ZeroBitfieldFollowsBitfield(const FieldDecl *FD,
602                                             const FieldDecl *LastFD) const {
603  return (FD->isBitField() && LastFD && LastFD->isBitField() &&
604          FD->getBitWidth()->EvaluateAsInt(*this).getZExtValue() == 0 &&
605          LastFD->getBitWidth()->EvaluateAsInt(*this).getZExtValue() != 0);
606}
607
608bool ASTContext::BitfieldFollowsBitfield(const FieldDecl *FD,
609                                         const FieldDecl *LastFD) const {
610  return (FD->isBitField() && LastFD && LastFD->isBitField() &&
611          FD->getBitWidth()->EvaluateAsInt(*this).getZExtValue() &&
612          LastFD->getBitWidth()->EvaluateAsInt(*this).getZExtValue());
613}
614
615bool ASTContext::NonBitfieldFollowsBitfield(const FieldDecl *FD,
616                                         const FieldDecl *LastFD) const {
617  return (!FD->isBitField() && LastFD && LastFD->isBitField() &&
618          LastFD->getBitWidth()->EvaluateAsInt(*this).getZExtValue());
619}
620
621bool ASTContext::BitfieldFollowsNonBitfield(const FieldDecl *FD,
622                                             const FieldDecl *LastFD) const {
623  return (FD->isBitField() && LastFD && !LastFD->isBitField() &&
624          FD->getBitWidth()->EvaluateAsInt(*this).getZExtValue());
625}
626
627ASTContext::overridden_cxx_method_iterator
628ASTContext::overridden_methods_begin(const CXXMethodDecl *Method) const {
629  llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector>::const_iterator Pos
630    = OverriddenMethods.find(Method);
631  if (Pos == OverriddenMethods.end())
632    return 0;
633
634  return Pos->second.begin();
635}
636
637ASTContext::overridden_cxx_method_iterator
638ASTContext::overridden_methods_end(const CXXMethodDecl *Method) const {
639  llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector>::const_iterator Pos
640    = OverriddenMethods.find(Method);
641  if (Pos == OverriddenMethods.end())
642    return 0;
643
644  return Pos->second.end();
645}
646
647unsigned
648ASTContext::overridden_methods_size(const CXXMethodDecl *Method) const {
649  llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector>::const_iterator Pos
650    = OverriddenMethods.find(Method);
651  if (Pos == OverriddenMethods.end())
652    return 0;
653
654  return Pos->second.size();
655}
656
657void ASTContext::addOverriddenMethod(const CXXMethodDecl *Method,
658                                     const CXXMethodDecl *Overridden) {
659  OverriddenMethods[Method].push_back(Overridden);
660}
661
662//===----------------------------------------------------------------------===//
663//                         Type Sizing and Analysis
664//===----------------------------------------------------------------------===//
665
666/// getFloatTypeSemantics - Return the APFloat 'semantics' for the specified
667/// scalar floating point type.
668const llvm::fltSemantics &ASTContext::getFloatTypeSemantics(QualType T) const {
669  const BuiltinType *BT = T->getAs<BuiltinType>();
670  assert(BT && "Not a floating point type!");
671  switch (BT->getKind()) {
672  default: assert(0 && "Not a floating point type!");
673  case BuiltinType::Float:      return Target.getFloatFormat();
674  case BuiltinType::Double:     return Target.getDoubleFormat();
675  case BuiltinType::LongDouble: return Target.getLongDoubleFormat();
676  }
677}
678
679/// getDeclAlign - Return a conservative estimate of the alignment of the
680/// specified decl.  Note that bitfields do not have a valid alignment, so
681/// this method will assert on them.
682/// If @p RefAsPointee, references are treated like their underlying type
683/// (for alignof), else they're treated like pointers (for CodeGen).
684CharUnits ASTContext::getDeclAlign(const Decl *D, bool RefAsPointee) const {
685  unsigned Align = Target.getCharWidth();
686
687  bool UseAlignAttrOnly = false;
688  if (unsigned AlignFromAttr = D->getMaxAlignment()) {
689    Align = AlignFromAttr;
690
691    // __attribute__((aligned)) can increase or decrease alignment
692    // *except* on a struct or struct member, where it only increases
693    // alignment unless 'packed' is also specified.
694    //
695    // It is an error for [[align]] to decrease alignment, so we can
696    // ignore that possibility;  Sema should diagnose it.
697    if (isa<FieldDecl>(D)) {
698      UseAlignAttrOnly = D->hasAttr<PackedAttr>() ||
699        cast<FieldDecl>(D)->getParent()->hasAttr<PackedAttr>();
700    } else {
701      UseAlignAttrOnly = true;
702    }
703  }
704  else if (isa<FieldDecl>(D))
705      UseAlignAttrOnly =
706        D->hasAttr<PackedAttr>() ||
707        cast<FieldDecl>(D)->getParent()->hasAttr<PackedAttr>();
708
709  // If we're using the align attribute only, just ignore everything
710  // else about the declaration and its type.
711  if (UseAlignAttrOnly) {
712    // do nothing
713
714  } else if (const ValueDecl *VD = dyn_cast<ValueDecl>(D)) {
715    QualType T = VD->getType();
716    if (const ReferenceType* RT = T->getAs<ReferenceType>()) {
717      if (RefAsPointee)
718        T = RT->getPointeeType();
719      else
720        T = getPointerType(RT->getPointeeType());
721    }
722    if (!T->isIncompleteType() && !T->isFunctionType()) {
723      // Adjust alignments of declarations with array type by the
724      // large-array alignment on the target.
725      unsigned MinWidth = Target.getLargeArrayMinWidth();
726      const ArrayType *arrayType;
727      if (MinWidth && (arrayType = getAsArrayType(T))) {
728        if (isa<VariableArrayType>(arrayType))
729          Align = std::max(Align, Target.getLargeArrayAlign());
730        else if (isa<ConstantArrayType>(arrayType) &&
731                 MinWidth <= getTypeSize(cast<ConstantArrayType>(arrayType)))
732          Align = std::max(Align, Target.getLargeArrayAlign());
733
734        // Walk through any array types while we're at it.
735        T = getBaseElementType(arrayType);
736      }
737      Align = std::max(Align, getPreferredTypeAlign(T.getTypePtr()));
738    }
739
740    // Fields can be subject to extra alignment constraints, like if
741    // the field is packed, the struct is packed, or the struct has a
742    // a max-field-alignment constraint (#pragma pack).  So calculate
743    // the actual alignment of the field within the struct, and then
744    // (as we're expected to) constrain that by the alignment of the type.
745    if (const FieldDecl *field = dyn_cast<FieldDecl>(VD)) {
746      // So calculate the alignment of the field.
747      const ASTRecordLayout &layout = getASTRecordLayout(field->getParent());
748
749      // Start with the record's overall alignment.
750      unsigned fieldAlign = toBits(layout.getAlignment());
751
752      // Use the GCD of that and the offset within the record.
753      uint64_t offset = layout.getFieldOffset(field->getFieldIndex());
754      if (offset > 0) {
755        // Alignment is always a power of 2, so the GCD will be a power of 2,
756        // which means we get to do this crazy thing instead of Euclid's.
757        uint64_t lowBitOfOffset = offset & (~offset + 1);
758        if (lowBitOfOffset < fieldAlign)
759          fieldAlign = static_cast<unsigned>(lowBitOfOffset);
760      }
761
762      Align = std::min(Align, fieldAlign);
763    }
764  }
765
766  return toCharUnitsFromBits(Align);
767}
768
769std::pair<CharUnits, CharUnits>
770ASTContext::getTypeInfoInChars(const Type *T) const {
771  std::pair<uint64_t, unsigned> Info = getTypeInfo(T);
772  return std::make_pair(toCharUnitsFromBits(Info.first),
773                        toCharUnitsFromBits(Info.second));
774}
775
776std::pair<CharUnits, CharUnits>
777ASTContext::getTypeInfoInChars(QualType T) const {
778  return getTypeInfoInChars(T.getTypePtr());
779}
780
781/// getTypeSize - Return the size of the specified type, in bits.  This method
782/// does not work on incomplete types.
783///
784/// FIXME: Pointers into different addr spaces could have different sizes and
785/// alignment requirements: getPointerInfo should take an AddrSpace, this
786/// should take a QualType, &c.
787std::pair<uint64_t, unsigned>
788ASTContext::getTypeInfo(const Type *T) const {
789  uint64_t Width=0;
790  unsigned Align=8;
791  switch (T->getTypeClass()) {
792#define TYPE(Class, Base)
793#define ABSTRACT_TYPE(Class, Base)
794#define NON_CANONICAL_TYPE(Class, Base)
795#define DEPENDENT_TYPE(Class, Base) case Type::Class:
796#include "clang/AST/TypeNodes.def"
797    llvm_unreachable("Should not see dependent types");
798    break;
799
800  case Type::FunctionNoProto:
801  case Type::FunctionProto:
802    // GCC extension: alignof(function) = 32 bits
803    Width = 0;
804    Align = 32;
805    break;
806
807  case Type::IncompleteArray:
808  case Type::VariableArray:
809    Width = 0;
810    Align = getTypeAlign(cast<ArrayType>(T)->getElementType());
811    break;
812
813  case Type::ConstantArray: {
814    const ConstantArrayType *CAT = cast<ConstantArrayType>(T);
815
816    std::pair<uint64_t, unsigned> EltInfo = getTypeInfo(CAT->getElementType());
817    Width = EltInfo.first*CAT->getSize().getZExtValue();
818    Align = EltInfo.second;
819    Width = llvm::RoundUpToAlignment(Width, Align);
820    break;
821  }
822  case Type::ExtVector:
823  case Type::Vector: {
824    const VectorType *VT = cast<VectorType>(T);
825    std::pair<uint64_t, unsigned> EltInfo = getTypeInfo(VT->getElementType());
826    Width = EltInfo.first*VT->getNumElements();
827    Align = Width;
828    // If the alignment is not a power of 2, round up to the next power of 2.
829    // This happens for non-power-of-2 length vectors.
830    if (Align & (Align-1)) {
831      Align = llvm::NextPowerOf2(Align);
832      Width = llvm::RoundUpToAlignment(Width, Align);
833    }
834    break;
835  }
836
837  case Type::Builtin:
838    switch (cast<BuiltinType>(T)->getKind()) {
839    default: assert(0 && "Unknown builtin type!");
840    case BuiltinType::Void:
841      // GCC extension: alignof(void) = 8 bits.
842      Width = 0;
843      Align = 8;
844      break;
845
846    case BuiltinType::Bool:
847      Width = Target.getBoolWidth();
848      Align = Target.getBoolAlign();
849      break;
850    case BuiltinType::Char_S:
851    case BuiltinType::Char_U:
852    case BuiltinType::UChar:
853    case BuiltinType::SChar:
854      Width = Target.getCharWidth();
855      Align = Target.getCharAlign();
856      break;
857    case BuiltinType::WChar_S:
858    case BuiltinType::WChar_U:
859      Width = Target.getWCharWidth();
860      Align = Target.getWCharAlign();
861      break;
862    case BuiltinType::Char16:
863      Width = Target.getChar16Width();
864      Align = Target.getChar16Align();
865      break;
866    case BuiltinType::Char32:
867      Width = Target.getChar32Width();
868      Align = Target.getChar32Align();
869      break;
870    case BuiltinType::UShort:
871    case BuiltinType::Short:
872      Width = Target.getShortWidth();
873      Align = Target.getShortAlign();
874      break;
875    case BuiltinType::UInt:
876    case BuiltinType::Int:
877      Width = Target.getIntWidth();
878      Align = Target.getIntAlign();
879      break;
880    case BuiltinType::ULong:
881    case BuiltinType::Long:
882      Width = Target.getLongWidth();
883      Align = Target.getLongAlign();
884      break;
885    case BuiltinType::ULongLong:
886    case BuiltinType::LongLong:
887      Width = Target.getLongLongWidth();
888      Align = Target.getLongLongAlign();
889      break;
890    case BuiltinType::Int128:
891    case BuiltinType::UInt128:
892      Width = 128;
893      Align = 128; // int128_t is 128-bit aligned on all targets.
894      break;
895    case BuiltinType::Float:
896      Width = Target.getFloatWidth();
897      Align = Target.getFloatAlign();
898      break;
899    case BuiltinType::Double:
900      Width = Target.getDoubleWidth();
901      Align = Target.getDoubleAlign();
902      break;
903    case BuiltinType::LongDouble:
904      Width = Target.getLongDoubleWidth();
905      Align = Target.getLongDoubleAlign();
906      break;
907    case BuiltinType::NullPtr:
908      Width = Target.getPointerWidth(0); // C++ 3.9.1p11: sizeof(nullptr_t)
909      Align = Target.getPointerAlign(0); //   == sizeof(void*)
910      break;
911    case BuiltinType::ObjCId:
912    case BuiltinType::ObjCClass:
913    case BuiltinType::ObjCSel:
914      Width = Target.getPointerWidth(0);
915      Align = Target.getPointerAlign(0);
916      break;
917    }
918    break;
919  case Type::ObjCObjectPointer:
920    Width = Target.getPointerWidth(0);
921    Align = Target.getPointerAlign(0);
922    break;
923  case Type::BlockPointer: {
924    unsigned AS = getTargetAddressSpace(
925        cast<BlockPointerType>(T)->getPointeeType());
926    Width = Target.getPointerWidth(AS);
927    Align = Target.getPointerAlign(AS);
928    break;
929  }
930  case Type::LValueReference:
931  case Type::RValueReference: {
932    // alignof and sizeof should never enter this code path here, so we go
933    // the pointer route.
934    unsigned AS = getTargetAddressSpace(
935        cast<ReferenceType>(T)->getPointeeType());
936    Width = Target.getPointerWidth(AS);
937    Align = Target.getPointerAlign(AS);
938    break;
939  }
940  case Type::Pointer: {
941    unsigned AS = getTargetAddressSpace(cast<PointerType>(T)->getPointeeType());
942    Width = Target.getPointerWidth(AS);
943    Align = Target.getPointerAlign(AS);
944    break;
945  }
946  case Type::MemberPointer: {
947    const MemberPointerType *MPT = cast<MemberPointerType>(T);
948    std::pair<uint64_t, unsigned> PtrDiffInfo =
949      getTypeInfo(getPointerDiffType());
950    Width = PtrDiffInfo.first * ABI->getMemberPointerSize(MPT);
951    Align = PtrDiffInfo.second;
952    break;
953  }
954  case Type::Complex: {
955    // Complex types have the same alignment as their elements, but twice the
956    // size.
957    std::pair<uint64_t, unsigned> EltInfo =
958      getTypeInfo(cast<ComplexType>(T)->getElementType());
959    Width = EltInfo.first*2;
960    Align = EltInfo.second;
961    break;
962  }
963  case Type::ObjCObject:
964    return getTypeInfo(cast<ObjCObjectType>(T)->getBaseType().getTypePtr());
965  case Type::ObjCInterface: {
966    const ObjCInterfaceType *ObjCI = cast<ObjCInterfaceType>(T);
967    const ASTRecordLayout &Layout = getASTObjCInterfaceLayout(ObjCI->getDecl());
968    Width = toBits(Layout.getSize());
969    Align = toBits(Layout.getAlignment());
970    break;
971  }
972  case Type::Record:
973  case Type::Enum: {
974    const TagType *TT = cast<TagType>(T);
975
976    if (TT->getDecl()->isInvalidDecl()) {
977      Width = 8;
978      Align = 8;
979      break;
980    }
981
982    if (const EnumType *ET = dyn_cast<EnumType>(TT))
983      return getTypeInfo(ET->getDecl()->getIntegerType());
984
985    const RecordType *RT = cast<RecordType>(TT);
986    const ASTRecordLayout &Layout = getASTRecordLayout(RT->getDecl());
987    Width = toBits(Layout.getSize());
988    Align = toBits(Layout.getAlignment());
989    break;
990  }
991
992  case Type::SubstTemplateTypeParm:
993    return getTypeInfo(cast<SubstTemplateTypeParmType>(T)->
994                       getReplacementType().getTypePtr());
995
996  case Type::Auto: {
997    const AutoType *A = cast<AutoType>(T);
998    assert(A->isDeduced() && "Cannot request the size of a dependent type");
999    return getTypeInfo(A->getDeducedType().getTypePtr());
1000  }
1001
1002  case Type::Paren:
1003    return getTypeInfo(cast<ParenType>(T)->getInnerType().getTypePtr());
1004
1005  case Type::Typedef: {
1006    const TypedefNameDecl *Typedef = cast<TypedefType>(T)->getDecl();
1007    std::pair<uint64_t, unsigned> Info
1008      = getTypeInfo(Typedef->getUnderlyingType().getTypePtr());
1009    // If the typedef has an aligned attribute on it, it overrides any computed
1010    // alignment we have.  This violates the GCC documentation (which says that
1011    // attribute(aligned) can only round up) but matches its implementation.
1012    if (unsigned AttrAlign = Typedef->getMaxAlignment())
1013      Align = AttrAlign;
1014    else
1015      Align = Info.second;
1016    Width = Info.first;
1017    break;
1018  }
1019
1020  case Type::TypeOfExpr:
1021    return getTypeInfo(cast<TypeOfExprType>(T)->getUnderlyingExpr()->getType()
1022                         .getTypePtr());
1023
1024  case Type::TypeOf:
1025    return getTypeInfo(cast<TypeOfType>(T)->getUnderlyingType().getTypePtr());
1026
1027  case Type::Decltype:
1028    return getTypeInfo(cast<DecltypeType>(T)->getUnderlyingExpr()->getType()
1029                        .getTypePtr());
1030
1031  case Type::UnaryTransform:
1032    return getTypeInfo(cast<UnaryTransformType>(T)->getUnderlyingType());
1033
1034  case Type::Elaborated:
1035    return getTypeInfo(cast<ElaboratedType>(T)->getNamedType().getTypePtr());
1036
1037  case Type::Attributed:
1038    return getTypeInfo(
1039                  cast<AttributedType>(T)->getEquivalentType().getTypePtr());
1040
1041  case Type::TemplateSpecialization: {
1042    assert(getCanonicalType(T) != T &&
1043           "Cannot request the size of a dependent type");
1044    const TemplateSpecializationType *TST = cast<TemplateSpecializationType>(T);
1045    // A type alias template specialization may refer to a typedef with the
1046    // aligned attribute on it.
1047    if (TST->isTypeAlias())
1048      return getTypeInfo(TST->getAliasedType().getTypePtr());
1049    else
1050      return getTypeInfo(getCanonicalType(T));
1051  }
1052
1053  }
1054
1055  assert(Align && (Align & (Align-1)) == 0 && "Alignment must be power of 2");
1056  return std::make_pair(Width, Align);
1057}
1058
1059/// toCharUnitsFromBits - Convert a size in bits to a size in characters.
1060CharUnits ASTContext::toCharUnitsFromBits(int64_t BitSize) const {
1061  return CharUnits::fromQuantity(BitSize / getCharWidth());
1062}
1063
1064/// toBits - Convert a size in characters to a size in characters.
1065int64_t ASTContext::toBits(CharUnits CharSize) const {
1066  return CharSize.getQuantity() * getCharWidth();
1067}
1068
1069/// getTypeSizeInChars - Return the size of the specified type, in characters.
1070/// This method does not work on incomplete types.
1071CharUnits ASTContext::getTypeSizeInChars(QualType T) const {
1072  return toCharUnitsFromBits(getTypeSize(T));
1073}
1074CharUnits ASTContext::getTypeSizeInChars(const Type *T) const {
1075  return toCharUnitsFromBits(getTypeSize(T));
1076}
1077
1078/// getTypeAlignInChars - Return the ABI-specified alignment of a type, in
1079/// characters. This method does not work on incomplete types.
1080CharUnits ASTContext::getTypeAlignInChars(QualType T) const {
1081  return toCharUnitsFromBits(getTypeAlign(T));
1082}
1083CharUnits ASTContext::getTypeAlignInChars(const Type *T) const {
1084  return toCharUnitsFromBits(getTypeAlign(T));
1085}
1086
1087/// getPreferredTypeAlign - Return the "preferred" alignment of the specified
1088/// type for the current target in bits.  This can be different than the ABI
1089/// alignment in cases where it is beneficial for performance to overalign
1090/// a data type.
1091unsigned ASTContext::getPreferredTypeAlign(const Type *T) const {
1092  unsigned ABIAlign = getTypeAlign(T);
1093
1094  // Double and long long should be naturally aligned if possible.
1095  if (const ComplexType* CT = T->getAs<ComplexType>())
1096    T = CT->getElementType().getTypePtr();
1097  if (T->isSpecificBuiltinType(BuiltinType::Double) ||
1098      T->isSpecificBuiltinType(BuiltinType::LongLong))
1099    return std::max(ABIAlign, (unsigned)getTypeSize(T));
1100
1101  return ABIAlign;
1102}
1103
1104/// DeepCollectObjCIvars -
1105/// This routine first collects all declared, but not synthesized, ivars in
1106/// super class and then collects all ivars, including those synthesized for
1107/// current class. This routine is used for implementation of current class
1108/// when all ivars, declared and synthesized are known.
1109///
1110void ASTContext::DeepCollectObjCIvars(const ObjCInterfaceDecl *OI,
1111                                      bool leafClass,
1112                            SmallVectorImpl<const ObjCIvarDecl*> &Ivars) const {
1113  if (const ObjCInterfaceDecl *SuperClass = OI->getSuperClass())
1114    DeepCollectObjCIvars(SuperClass, false, Ivars);
1115  if (!leafClass) {
1116    for (ObjCInterfaceDecl::ivar_iterator I = OI->ivar_begin(),
1117         E = OI->ivar_end(); I != E; ++I)
1118      Ivars.push_back(*I);
1119  }
1120  else {
1121    ObjCInterfaceDecl *IDecl = const_cast<ObjCInterfaceDecl *>(OI);
1122    for (const ObjCIvarDecl *Iv = IDecl->all_declared_ivar_begin(); Iv;
1123         Iv= Iv->getNextIvar())
1124      Ivars.push_back(Iv);
1125  }
1126}
1127
1128/// CollectInheritedProtocols - Collect all protocols in current class and
1129/// those inherited by it.
1130void ASTContext::CollectInheritedProtocols(const Decl *CDecl,
1131                          llvm::SmallPtrSet<ObjCProtocolDecl*, 8> &Protocols) {
1132  if (const ObjCInterfaceDecl *OI = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
1133    // We can use protocol_iterator here instead of
1134    // all_referenced_protocol_iterator since we are walking all categories.
1135    for (ObjCInterfaceDecl::all_protocol_iterator P = OI->all_referenced_protocol_begin(),
1136         PE = OI->all_referenced_protocol_end(); P != PE; ++P) {
1137      ObjCProtocolDecl *Proto = (*P);
1138      Protocols.insert(Proto);
1139      for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
1140           PE = Proto->protocol_end(); P != PE; ++P) {
1141        Protocols.insert(*P);
1142        CollectInheritedProtocols(*P, Protocols);
1143      }
1144    }
1145
1146    // Categories of this Interface.
1147    for (const ObjCCategoryDecl *CDeclChain = OI->getCategoryList();
1148         CDeclChain; CDeclChain = CDeclChain->getNextClassCategory())
1149      CollectInheritedProtocols(CDeclChain, Protocols);
1150    if (ObjCInterfaceDecl *SD = OI->getSuperClass())
1151      while (SD) {
1152        CollectInheritedProtocols(SD, Protocols);
1153        SD = SD->getSuperClass();
1154      }
1155  } else if (const ObjCCategoryDecl *OC = dyn_cast<ObjCCategoryDecl>(CDecl)) {
1156    for (ObjCCategoryDecl::protocol_iterator P = OC->protocol_begin(),
1157         PE = OC->protocol_end(); P != PE; ++P) {
1158      ObjCProtocolDecl *Proto = (*P);
1159      Protocols.insert(Proto);
1160      for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
1161           PE = Proto->protocol_end(); P != PE; ++P)
1162        CollectInheritedProtocols(*P, Protocols);
1163    }
1164  } else if (const ObjCProtocolDecl *OP = dyn_cast<ObjCProtocolDecl>(CDecl)) {
1165    for (ObjCProtocolDecl::protocol_iterator P = OP->protocol_begin(),
1166         PE = OP->protocol_end(); P != PE; ++P) {
1167      ObjCProtocolDecl *Proto = (*P);
1168      Protocols.insert(Proto);
1169      for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
1170           PE = Proto->protocol_end(); P != PE; ++P)
1171        CollectInheritedProtocols(*P, Protocols);
1172    }
1173  }
1174}
1175
1176unsigned ASTContext::CountNonClassIvars(const ObjCInterfaceDecl *OI) const {
1177  unsigned count = 0;
1178  // Count ivars declared in class extension.
1179  for (const ObjCCategoryDecl *CDecl = OI->getFirstClassExtension(); CDecl;
1180       CDecl = CDecl->getNextClassExtension())
1181    count += CDecl->ivar_size();
1182
1183  // Count ivar defined in this class's implementation.  This
1184  // includes synthesized ivars.
1185  if (ObjCImplementationDecl *ImplDecl = OI->getImplementation())
1186    count += ImplDecl->ivar_size();
1187
1188  return count;
1189}
1190
1191/// \brief Get the implementation of ObjCInterfaceDecl,or NULL if none exists.
1192ObjCImplementationDecl *ASTContext::getObjCImplementation(ObjCInterfaceDecl *D) {
1193  llvm::DenseMap<ObjCContainerDecl*, ObjCImplDecl*>::iterator
1194    I = ObjCImpls.find(D);
1195  if (I != ObjCImpls.end())
1196    return cast<ObjCImplementationDecl>(I->second);
1197  return 0;
1198}
1199/// \brief Get the implementation of ObjCCategoryDecl, or NULL if none exists.
1200ObjCCategoryImplDecl *ASTContext::getObjCImplementation(ObjCCategoryDecl *D) {
1201  llvm::DenseMap<ObjCContainerDecl*, ObjCImplDecl*>::iterator
1202    I = ObjCImpls.find(D);
1203  if (I != ObjCImpls.end())
1204    return cast<ObjCCategoryImplDecl>(I->second);
1205  return 0;
1206}
1207
1208/// \brief Set the implementation of ObjCInterfaceDecl.
1209void ASTContext::setObjCImplementation(ObjCInterfaceDecl *IFaceD,
1210                           ObjCImplementationDecl *ImplD) {
1211  assert(IFaceD && ImplD && "Passed null params");
1212  ObjCImpls[IFaceD] = ImplD;
1213}
1214/// \brief Set the implementation of ObjCCategoryDecl.
1215void ASTContext::setObjCImplementation(ObjCCategoryDecl *CatD,
1216                           ObjCCategoryImplDecl *ImplD) {
1217  assert(CatD && ImplD && "Passed null params");
1218  ObjCImpls[CatD] = ImplD;
1219}
1220
1221/// \brief Get the copy initialization expression of VarDecl,or NULL if
1222/// none exists.
1223Expr *ASTContext::getBlockVarCopyInits(const VarDecl*VD) {
1224  assert(VD && "Passed null params");
1225  assert(VD->hasAttr<BlocksAttr>() &&
1226         "getBlockVarCopyInits - not __block var");
1227  llvm::DenseMap<const VarDecl*, Expr*>::iterator
1228    I = BlockVarCopyInits.find(VD);
1229  return (I != BlockVarCopyInits.end()) ? cast<Expr>(I->second) : 0;
1230}
1231
1232/// \brief Set the copy inialization expression of a block var decl.
1233void ASTContext::setBlockVarCopyInits(VarDecl*VD, Expr* Init) {
1234  assert(VD && Init && "Passed null params");
1235  assert(VD->hasAttr<BlocksAttr>() &&
1236         "setBlockVarCopyInits - not __block var");
1237  BlockVarCopyInits[VD] = Init;
1238}
1239
1240/// \brief Allocate an uninitialized TypeSourceInfo.
1241///
1242/// The caller should initialize the memory held by TypeSourceInfo using
1243/// the TypeLoc wrappers.
1244///
1245/// \param T the type that will be the basis for type source info. This type
1246/// should refer to how the declarator was written in source code, not to
1247/// what type semantic analysis resolved the declarator to.
1248TypeSourceInfo *ASTContext::CreateTypeSourceInfo(QualType T,
1249                                                 unsigned DataSize) const {
1250  if (!DataSize)
1251    DataSize = TypeLoc::getFullDataSizeForType(T);
1252  else
1253    assert(DataSize == TypeLoc::getFullDataSizeForType(T) &&
1254           "incorrect data size provided to CreateTypeSourceInfo!");
1255
1256  TypeSourceInfo *TInfo =
1257    (TypeSourceInfo*)BumpAlloc.Allocate(sizeof(TypeSourceInfo) + DataSize, 8);
1258  new (TInfo) TypeSourceInfo(T);
1259  return TInfo;
1260}
1261
1262TypeSourceInfo *ASTContext::getTrivialTypeSourceInfo(QualType T,
1263                                                     SourceLocation L) const {
1264  TypeSourceInfo *DI = CreateTypeSourceInfo(T);
1265  DI->getTypeLoc().initialize(const_cast<ASTContext &>(*this), L);
1266  return DI;
1267}
1268
1269const ASTRecordLayout &
1270ASTContext::getASTObjCInterfaceLayout(const ObjCInterfaceDecl *D) const {
1271  return getObjCLayout(D, 0);
1272}
1273
1274const ASTRecordLayout &
1275ASTContext::getASTObjCImplementationLayout(
1276                                        const ObjCImplementationDecl *D) const {
1277  return getObjCLayout(D->getClassInterface(), D);
1278}
1279
1280//===----------------------------------------------------------------------===//
1281//                   Type creation/memoization methods
1282//===----------------------------------------------------------------------===//
1283
1284QualType
1285ASTContext::getExtQualType(const Type *baseType, Qualifiers quals) const {
1286  unsigned fastQuals = quals.getFastQualifiers();
1287  quals.removeFastQualifiers();
1288
1289  // Check if we've already instantiated this type.
1290  llvm::FoldingSetNodeID ID;
1291  ExtQuals::Profile(ID, baseType, quals);
1292  void *insertPos = 0;
1293  if (ExtQuals *eq = ExtQualNodes.FindNodeOrInsertPos(ID, insertPos)) {
1294    assert(eq->getQualifiers() == quals);
1295    return QualType(eq, fastQuals);
1296  }
1297
1298  // If the base type is not canonical, make the appropriate canonical type.
1299  QualType canon;
1300  if (!baseType->isCanonicalUnqualified()) {
1301    SplitQualType canonSplit = baseType->getCanonicalTypeInternal().split();
1302    canonSplit.second.addConsistentQualifiers(quals);
1303    canon = getExtQualType(canonSplit.first, canonSplit.second);
1304
1305    // Re-find the insert position.
1306    (void) ExtQualNodes.FindNodeOrInsertPos(ID, insertPos);
1307  }
1308
1309  ExtQuals *eq = new (*this, TypeAlignment) ExtQuals(baseType, canon, quals);
1310  ExtQualNodes.InsertNode(eq, insertPos);
1311  return QualType(eq, fastQuals);
1312}
1313
1314QualType
1315ASTContext::getAddrSpaceQualType(QualType T, unsigned AddressSpace) const {
1316  QualType CanT = getCanonicalType(T);
1317  if (CanT.getAddressSpace() == AddressSpace)
1318    return T;
1319
1320  // If we are composing extended qualifiers together, merge together
1321  // into one ExtQuals node.
1322  QualifierCollector Quals;
1323  const Type *TypeNode = Quals.strip(T);
1324
1325  // If this type already has an address space specified, it cannot get
1326  // another one.
1327  assert(!Quals.hasAddressSpace() &&
1328         "Type cannot be in multiple addr spaces!");
1329  Quals.addAddressSpace(AddressSpace);
1330
1331  return getExtQualType(TypeNode, Quals);
1332}
1333
1334QualType ASTContext::getObjCGCQualType(QualType T,
1335                                       Qualifiers::GC GCAttr) const {
1336  QualType CanT = getCanonicalType(T);
1337  if (CanT.getObjCGCAttr() == GCAttr)
1338    return T;
1339
1340  if (const PointerType *ptr = T->getAs<PointerType>()) {
1341    QualType Pointee = ptr->getPointeeType();
1342    if (Pointee->isAnyPointerType()) {
1343      QualType ResultType = getObjCGCQualType(Pointee, GCAttr);
1344      return getPointerType(ResultType);
1345    }
1346  }
1347
1348  // If we are composing extended qualifiers together, merge together
1349  // into one ExtQuals node.
1350  QualifierCollector Quals;
1351  const Type *TypeNode = Quals.strip(T);
1352
1353  // If this type already has an ObjCGC specified, it cannot get
1354  // another one.
1355  assert(!Quals.hasObjCGCAttr() &&
1356         "Type cannot have multiple ObjCGCs!");
1357  Quals.addObjCGCAttr(GCAttr);
1358
1359  return getExtQualType(TypeNode, Quals);
1360}
1361
1362const FunctionType *ASTContext::adjustFunctionType(const FunctionType *T,
1363                                                   FunctionType::ExtInfo Info) {
1364  if (T->getExtInfo() == Info)
1365    return T;
1366
1367  QualType Result;
1368  if (const FunctionNoProtoType *FNPT = dyn_cast<FunctionNoProtoType>(T)) {
1369    Result = getFunctionNoProtoType(FNPT->getResultType(), Info);
1370  } else {
1371    const FunctionProtoType *FPT = cast<FunctionProtoType>(T);
1372    FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
1373    EPI.ExtInfo = Info;
1374    Result = getFunctionType(FPT->getResultType(), FPT->arg_type_begin(),
1375                             FPT->getNumArgs(), EPI);
1376  }
1377
1378  return cast<FunctionType>(Result.getTypePtr());
1379}
1380
1381/// getComplexType - Return the uniqued reference to the type for a complex
1382/// number with the specified element type.
1383QualType ASTContext::getComplexType(QualType T) const {
1384  // Unique pointers, to guarantee there is only one pointer of a particular
1385  // structure.
1386  llvm::FoldingSetNodeID ID;
1387  ComplexType::Profile(ID, T);
1388
1389  void *InsertPos = 0;
1390  if (ComplexType *CT = ComplexTypes.FindNodeOrInsertPos(ID, InsertPos))
1391    return QualType(CT, 0);
1392
1393  // If the pointee type isn't canonical, this won't be a canonical type either,
1394  // so fill in the canonical type field.
1395  QualType Canonical;
1396  if (!T.isCanonical()) {
1397    Canonical = getComplexType(getCanonicalType(T));
1398
1399    // Get the new insert position for the node we care about.
1400    ComplexType *NewIP = ComplexTypes.FindNodeOrInsertPos(ID, InsertPos);
1401    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1402  }
1403  ComplexType *New = new (*this, TypeAlignment) ComplexType(T, Canonical);
1404  Types.push_back(New);
1405  ComplexTypes.InsertNode(New, InsertPos);
1406  return QualType(New, 0);
1407}
1408
1409/// getPointerType - Return the uniqued reference to the type for a pointer to
1410/// the specified type.
1411QualType ASTContext::getPointerType(QualType T) const {
1412  // Unique pointers, to guarantee there is only one pointer of a particular
1413  // structure.
1414  llvm::FoldingSetNodeID ID;
1415  PointerType::Profile(ID, T);
1416
1417  void *InsertPos = 0;
1418  if (PointerType *PT = PointerTypes.FindNodeOrInsertPos(ID, InsertPos))
1419    return QualType(PT, 0);
1420
1421  // If the pointee type isn't canonical, this won't be a canonical type either,
1422  // so fill in the canonical type field.
1423  QualType Canonical;
1424  if (!T.isCanonical()) {
1425    Canonical = getPointerType(getCanonicalType(T));
1426
1427    // Get the new insert position for the node we care about.
1428    PointerType *NewIP = PointerTypes.FindNodeOrInsertPos(ID, InsertPos);
1429    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1430  }
1431  PointerType *New = new (*this, TypeAlignment) PointerType(T, Canonical);
1432  Types.push_back(New);
1433  PointerTypes.InsertNode(New, InsertPos);
1434  return QualType(New, 0);
1435}
1436
1437/// getBlockPointerType - Return the uniqued reference to the type for
1438/// a pointer to the specified block.
1439QualType ASTContext::getBlockPointerType(QualType T) const {
1440  assert(T->isFunctionType() && "block of function types only");
1441  // Unique pointers, to guarantee there is only one block of a particular
1442  // structure.
1443  llvm::FoldingSetNodeID ID;
1444  BlockPointerType::Profile(ID, T);
1445
1446  void *InsertPos = 0;
1447  if (BlockPointerType *PT =
1448        BlockPointerTypes.FindNodeOrInsertPos(ID, InsertPos))
1449    return QualType(PT, 0);
1450
1451  // If the block pointee type isn't canonical, this won't be a canonical
1452  // type either so fill in the canonical type field.
1453  QualType Canonical;
1454  if (!T.isCanonical()) {
1455    Canonical = getBlockPointerType(getCanonicalType(T));
1456
1457    // Get the new insert position for the node we care about.
1458    BlockPointerType *NewIP =
1459      BlockPointerTypes.FindNodeOrInsertPos(ID, InsertPos);
1460    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1461  }
1462  BlockPointerType *New
1463    = new (*this, TypeAlignment) BlockPointerType(T, Canonical);
1464  Types.push_back(New);
1465  BlockPointerTypes.InsertNode(New, InsertPos);
1466  return QualType(New, 0);
1467}
1468
1469/// getLValueReferenceType - Return the uniqued reference to the type for an
1470/// lvalue reference to the specified type.
1471QualType
1472ASTContext::getLValueReferenceType(QualType T, bool SpelledAsLValue) const {
1473  assert(getCanonicalType(T) != OverloadTy &&
1474         "Unresolved overloaded function type");
1475
1476  // Unique pointers, to guarantee there is only one pointer of a particular
1477  // structure.
1478  llvm::FoldingSetNodeID ID;
1479  ReferenceType::Profile(ID, T, SpelledAsLValue);
1480
1481  void *InsertPos = 0;
1482  if (LValueReferenceType *RT =
1483        LValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos))
1484    return QualType(RT, 0);
1485
1486  const ReferenceType *InnerRef = T->getAs<ReferenceType>();
1487
1488  // If the referencee type isn't canonical, this won't be a canonical type
1489  // either, so fill in the canonical type field.
1490  QualType Canonical;
1491  if (!SpelledAsLValue || InnerRef || !T.isCanonical()) {
1492    QualType PointeeType = (InnerRef ? InnerRef->getPointeeType() : T);
1493    Canonical = getLValueReferenceType(getCanonicalType(PointeeType));
1494
1495    // Get the new insert position for the node we care about.
1496    LValueReferenceType *NewIP =
1497      LValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos);
1498    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1499  }
1500
1501  LValueReferenceType *New
1502    = new (*this, TypeAlignment) LValueReferenceType(T, Canonical,
1503                                                     SpelledAsLValue);
1504  Types.push_back(New);
1505  LValueReferenceTypes.InsertNode(New, InsertPos);
1506
1507  return QualType(New, 0);
1508}
1509
1510/// getRValueReferenceType - Return the uniqued reference to the type for an
1511/// rvalue reference to the specified type.
1512QualType ASTContext::getRValueReferenceType(QualType T) const {
1513  // Unique pointers, to guarantee there is only one pointer of a particular
1514  // structure.
1515  llvm::FoldingSetNodeID ID;
1516  ReferenceType::Profile(ID, T, false);
1517
1518  void *InsertPos = 0;
1519  if (RValueReferenceType *RT =
1520        RValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos))
1521    return QualType(RT, 0);
1522
1523  const ReferenceType *InnerRef = T->getAs<ReferenceType>();
1524
1525  // If the referencee type isn't canonical, this won't be a canonical type
1526  // either, so fill in the canonical type field.
1527  QualType Canonical;
1528  if (InnerRef || !T.isCanonical()) {
1529    QualType PointeeType = (InnerRef ? InnerRef->getPointeeType() : T);
1530    Canonical = getRValueReferenceType(getCanonicalType(PointeeType));
1531
1532    // Get the new insert position for the node we care about.
1533    RValueReferenceType *NewIP =
1534      RValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos);
1535    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1536  }
1537
1538  RValueReferenceType *New
1539    = new (*this, TypeAlignment) RValueReferenceType(T, Canonical);
1540  Types.push_back(New);
1541  RValueReferenceTypes.InsertNode(New, InsertPos);
1542  return QualType(New, 0);
1543}
1544
1545/// getMemberPointerType - Return the uniqued reference to the type for a
1546/// member pointer to the specified type, in the specified class.
1547QualType ASTContext::getMemberPointerType(QualType T, const Type *Cls) const {
1548  // Unique pointers, to guarantee there is only one pointer of a particular
1549  // structure.
1550  llvm::FoldingSetNodeID ID;
1551  MemberPointerType::Profile(ID, T, Cls);
1552
1553  void *InsertPos = 0;
1554  if (MemberPointerType *PT =
1555      MemberPointerTypes.FindNodeOrInsertPos(ID, InsertPos))
1556    return QualType(PT, 0);
1557
1558  // If the pointee or class type isn't canonical, this won't be a canonical
1559  // type either, so fill in the canonical type field.
1560  QualType Canonical;
1561  if (!T.isCanonical() || !Cls->isCanonicalUnqualified()) {
1562    Canonical = getMemberPointerType(getCanonicalType(T),getCanonicalType(Cls));
1563
1564    // Get the new insert position for the node we care about.
1565    MemberPointerType *NewIP =
1566      MemberPointerTypes.FindNodeOrInsertPos(ID, InsertPos);
1567    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1568  }
1569  MemberPointerType *New
1570    = new (*this, TypeAlignment) MemberPointerType(T, Cls, Canonical);
1571  Types.push_back(New);
1572  MemberPointerTypes.InsertNode(New, InsertPos);
1573  return QualType(New, 0);
1574}
1575
1576/// getConstantArrayType - Return the unique reference to the type for an
1577/// array of the specified element type.
1578QualType ASTContext::getConstantArrayType(QualType EltTy,
1579                                          const llvm::APInt &ArySizeIn,
1580                                          ArrayType::ArraySizeModifier ASM,
1581                                          unsigned IndexTypeQuals) const {
1582  assert((EltTy->isDependentType() ||
1583          EltTy->isIncompleteType() || EltTy->isConstantSizeType()) &&
1584         "Constant array of VLAs is illegal!");
1585
1586  // Convert the array size into a canonical width matching the pointer size for
1587  // the target.
1588  llvm::APInt ArySize(ArySizeIn);
1589  ArySize =
1590    ArySize.zextOrTrunc(Target.getPointerWidth(getTargetAddressSpace(EltTy)));
1591
1592  llvm::FoldingSetNodeID ID;
1593  ConstantArrayType::Profile(ID, EltTy, ArySize, ASM, IndexTypeQuals);
1594
1595  void *InsertPos = 0;
1596  if (ConstantArrayType *ATP =
1597      ConstantArrayTypes.FindNodeOrInsertPos(ID, InsertPos))
1598    return QualType(ATP, 0);
1599
1600  // If the element type isn't canonical or has qualifiers, this won't
1601  // be a canonical type either, so fill in the canonical type field.
1602  QualType Canon;
1603  if (!EltTy.isCanonical() || EltTy.hasLocalQualifiers()) {
1604    SplitQualType canonSplit = getCanonicalType(EltTy).split();
1605    Canon = getConstantArrayType(QualType(canonSplit.first, 0), ArySize,
1606                                 ASM, IndexTypeQuals);
1607    Canon = getQualifiedType(Canon, canonSplit.second);
1608
1609    // Get the new insert position for the node we care about.
1610    ConstantArrayType *NewIP =
1611      ConstantArrayTypes.FindNodeOrInsertPos(ID, InsertPos);
1612    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1613  }
1614
1615  ConstantArrayType *New = new(*this,TypeAlignment)
1616    ConstantArrayType(EltTy, Canon, ArySize, ASM, IndexTypeQuals);
1617  ConstantArrayTypes.InsertNode(New, InsertPos);
1618  Types.push_back(New);
1619  return QualType(New, 0);
1620}
1621
1622/// getVariableArrayDecayedType - Turns the given type, which may be
1623/// variably-modified, into the corresponding type with all the known
1624/// sizes replaced with [*].
1625QualType ASTContext::getVariableArrayDecayedType(QualType type) const {
1626  // Vastly most common case.
1627  if (!type->isVariablyModifiedType()) return type;
1628
1629  QualType result;
1630
1631  SplitQualType split = type.getSplitDesugaredType();
1632  const Type *ty = split.first;
1633  switch (ty->getTypeClass()) {
1634#define TYPE(Class, Base)
1635#define ABSTRACT_TYPE(Class, Base)
1636#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
1637#include "clang/AST/TypeNodes.def"
1638    llvm_unreachable("didn't desugar past all non-canonical types?");
1639
1640  // These types should never be variably-modified.
1641  case Type::Builtin:
1642  case Type::Complex:
1643  case Type::Vector:
1644  case Type::ExtVector:
1645  case Type::DependentSizedExtVector:
1646  case Type::ObjCObject:
1647  case Type::ObjCInterface:
1648  case Type::ObjCObjectPointer:
1649  case Type::Record:
1650  case Type::Enum:
1651  case Type::UnresolvedUsing:
1652  case Type::TypeOfExpr:
1653  case Type::TypeOf:
1654  case Type::Decltype:
1655  case Type::UnaryTransform:
1656  case Type::DependentName:
1657  case Type::InjectedClassName:
1658  case Type::TemplateSpecialization:
1659  case Type::DependentTemplateSpecialization:
1660  case Type::TemplateTypeParm:
1661  case Type::SubstTemplateTypeParmPack:
1662  case Type::Auto:
1663  case Type::PackExpansion:
1664    llvm_unreachable("type should never be variably-modified");
1665
1666  // These types can be variably-modified but should never need to
1667  // further decay.
1668  case Type::FunctionNoProto:
1669  case Type::FunctionProto:
1670  case Type::BlockPointer:
1671  case Type::MemberPointer:
1672    return type;
1673
1674  // These types can be variably-modified.  All these modifications
1675  // preserve structure except as noted by comments.
1676  // TODO: if we ever care about optimizing VLAs, there are no-op
1677  // optimizations available here.
1678  case Type::Pointer:
1679    result = getPointerType(getVariableArrayDecayedType(
1680                              cast<PointerType>(ty)->getPointeeType()));
1681    break;
1682
1683  case Type::LValueReference: {
1684    const LValueReferenceType *lv = cast<LValueReferenceType>(ty);
1685    result = getLValueReferenceType(
1686                 getVariableArrayDecayedType(lv->getPointeeType()),
1687                                    lv->isSpelledAsLValue());
1688    break;
1689  }
1690
1691  case Type::RValueReference: {
1692    const RValueReferenceType *lv = cast<RValueReferenceType>(ty);
1693    result = getRValueReferenceType(
1694                 getVariableArrayDecayedType(lv->getPointeeType()));
1695    break;
1696  }
1697
1698  case Type::ConstantArray: {
1699    const ConstantArrayType *cat = cast<ConstantArrayType>(ty);
1700    result = getConstantArrayType(
1701                 getVariableArrayDecayedType(cat->getElementType()),
1702                                  cat->getSize(),
1703                                  cat->getSizeModifier(),
1704                                  cat->getIndexTypeCVRQualifiers());
1705    break;
1706  }
1707
1708  case Type::DependentSizedArray: {
1709    const DependentSizedArrayType *dat = cast<DependentSizedArrayType>(ty);
1710    result = getDependentSizedArrayType(
1711                 getVariableArrayDecayedType(dat->getElementType()),
1712                                        dat->getSizeExpr(),
1713                                        dat->getSizeModifier(),
1714                                        dat->getIndexTypeCVRQualifiers(),
1715                                        dat->getBracketsRange());
1716    break;
1717  }
1718
1719  // Turn incomplete types into [*] types.
1720  case Type::IncompleteArray: {
1721    const IncompleteArrayType *iat = cast<IncompleteArrayType>(ty);
1722    result = getVariableArrayType(
1723                 getVariableArrayDecayedType(iat->getElementType()),
1724                                  /*size*/ 0,
1725                                  ArrayType::Normal,
1726                                  iat->getIndexTypeCVRQualifiers(),
1727                                  SourceRange());
1728    break;
1729  }
1730
1731  // Turn VLA types into [*] types.
1732  case Type::VariableArray: {
1733    const VariableArrayType *vat = cast<VariableArrayType>(ty);
1734    result = getVariableArrayType(
1735                 getVariableArrayDecayedType(vat->getElementType()),
1736                                  /*size*/ 0,
1737                                  ArrayType::Star,
1738                                  vat->getIndexTypeCVRQualifiers(),
1739                                  vat->getBracketsRange());
1740    break;
1741  }
1742  }
1743
1744  // Apply the top-level qualifiers from the original.
1745  return getQualifiedType(result, split.second);
1746}
1747
1748/// getVariableArrayType - Returns a non-unique reference to the type for a
1749/// variable array of the specified element type.
1750QualType ASTContext::getVariableArrayType(QualType EltTy,
1751                                          Expr *NumElts,
1752                                          ArrayType::ArraySizeModifier ASM,
1753                                          unsigned IndexTypeQuals,
1754                                          SourceRange Brackets) const {
1755  // Since we don't unique expressions, it isn't possible to unique VLA's
1756  // that have an expression provided for their size.
1757  QualType Canon;
1758
1759  // Be sure to pull qualifiers off the element type.
1760  if (!EltTy.isCanonical() || EltTy.hasLocalQualifiers()) {
1761    SplitQualType canonSplit = getCanonicalType(EltTy).split();
1762    Canon = getVariableArrayType(QualType(canonSplit.first, 0), NumElts, ASM,
1763                                 IndexTypeQuals, Brackets);
1764    Canon = getQualifiedType(Canon, canonSplit.second);
1765  }
1766
1767  VariableArrayType *New = new(*this, TypeAlignment)
1768    VariableArrayType(EltTy, Canon, NumElts, ASM, IndexTypeQuals, Brackets);
1769
1770  VariableArrayTypes.push_back(New);
1771  Types.push_back(New);
1772  return QualType(New, 0);
1773}
1774
1775/// getDependentSizedArrayType - Returns a non-unique reference to
1776/// the type for a dependently-sized array of the specified element
1777/// type.
1778QualType ASTContext::getDependentSizedArrayType(QualType elementType,
1779                                                Expr *numElements,
1780                                                ArrayType::ArraySizeModifier ASM,
1781                                                unsigned elementTypeQuals,
1782                                                SourceRange brackets) const {
1783  assert((!numElements || numElements->isTypeDependent() ||
1784          numElements->isValueDependent()) &&
1785         "Size must be type- or value-dependent!");
1786
1787  // Dependently-sized array types that do not have a specified number
1788  // of elements will have their sizes deduced from a dependent
1789  // initializer.  We do no canonicalization here at all, which is okay
1790  // because they can't be used in most locations.
1791  if (!numElements) {
1792    DependentSizedArrayType *newType
1793      = new (*this, TypeAlignment)
1794          DependentSizedArrayType(*this, elementType, QualType(),
1795                                  numElements, ASM, elementTypeQuals,
1796                                  brackets);
1797    Types.push_back(newType);
1798    return QualType(newType, 0);
1799  }
1800
1801  // Otherwise, we actually build a new type every time, but we
1802  // also build a canonical type.
1803
1804  SplitQualType canonElementType = getCanonicalType(elementType).split();
1805
1806  void *insertPos = 0;
1807  llvm::FoldingSetNodeID ID;
1808  DependentSizedArrayType::Profile(ID, *this,
1809                                   QualType(canonElementType.first, 0),
1810                                   ASM, elementTypeQuals, numElements);
1811
1812  // Look for an existing type with these properties.
1813  DependentSizedArrayType *canonTy =
1814    DependentSizedArrayTypes.FindNodeOrInsertPos(ID, insertPos);
1815
1816  // If we don't have one, build one.
1817  if (!canonTy) {
1818    canonTy = new (*this, TypeAlignment)
1819      DependentSizedArrayType(*this, QualType(canonElementType.first, 0),
1820                              QualType(), numElements, ASM, elementTypeQuals,
1821                              brackets);
1822    DependentSizedArrayTypes.InsertNode(canonTy, insertPos);
1823    Types.push_back(canonTy);
1824  }
1825
1826  // Apply qualifiers from the element type to the array.
1827  QualType canon = getQualifiedType(QualType(canonTy,0),
1828                                    canonElementType.second);
1829
1830  // If we didn't need extra canonicalization for the element type,
1831  // then just use that as our result.
1832  if (QualType(canonElementType.first, 0) == elementType)
1833    return canon;
1834
1835  // Otherwise, we need to build a type which follows the spelling
1836  // of the element type.
1837  DependentSizedArrayType *sugaredType
1838    = new (*this, TypeAlignment)
1839        DependentSizedArrayType(*this, elementType, canon, numElements,
1840                                ASM, elementTypeQuals, brackets);
1841  Types.push_back(sugaredType);
1842  return QualType(sugaredType, 0);
1843}
1844
1845QualType ASTContext::getIncompleteArrayType(QualType elementType,
1846                                            ArrayType::ArraySizeModifier ASM,
1847                                            unsigned elementTypeQuals) const {
1848  llvm::FoldingSetNodeID ID;
1849  IncompleteArrayType::Profile(ID, elementType, ASM, elementTypeQuals);
1850
1851  void *insertPos = 0;
1852  if (IncompleteArrayType *iat =
1853       IncompleteArrayTypes.FindNodeOrInsertPos(ID, insertPos))
1854    return QualType(iat, 0);
1855
1856  // If the element type isn't canonical, this won't be a canonical type
1857  // either, so fill in the canonical type field.  We also have to pull
1858  // qualifiers off the element type.
1859  QualType canon;
1860
1861  if (!elementType.isCanonical() || elementType.hasLocalQualifiers()) {
1862    SplitQualType canonSplit = getCanonicalType(elementType).split();
1863    canon = getIncompleteArrayType(QualType(canonSplit.first, 0),
1864                                   ASM, elementTypeQuals);
1865    canon = getQualifiedType(canon, canonSplit.second);
1866
1867    // Get the new insert position for the node we care about.
1868    IncompleteArrayType *existing =
1869      IncompleteArrayTypes.FindNodeOrInsertPos(ID, insertPos);
1870    assert(!existing && "Shouldn't be in the map!"); (void) existing;
1871  }
1872
1873  IncompleteArrayType *newType = new (*this, TypeAlignment)
1874    IncompleteArrayType(elementType, canon, ASM, elementTypeQuals);
1875
1876  IncompleteArrayTypes.InsertNode(newType, insertPos);
1877  Types.push_back(newType);
1878  return QualType(newType, 0);
1879}
1880
1881/// getVectorType - Return the unique reference to a vector type of
1882/// the specified element type and size. VectorType must be a built-in type.
1883QualType ASTContext::getVectorType(QualType vecType, unsigned NumElts,
1884                                   VectorType::VectorKind VecKind) const {
1885  assert(vecType->isBuiltinType());
1886
1887  // Check if we've already instantiated a vector of this type.
1888  llvm::FoldingSetNodeID ID;
1889  VectorType::Profile(ID, vecType, NumElts, Type::Vector, VecKind);
1890
1891  void *InsertPos = 0;
1892  if (VectorType *VTP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos))
1893    return QualType(VTP, 0);
1894
1895  // If the element type isn't canonical, this won't be a canonical type either,
1896  // so fill in the canonical type field.
1897  QualType Canonical;
1898  if (!vecType.isCanonical()) {
1899    Canonical = getVectorType(getCanonicalType(vecType), NumElts, VecKind);
1900
1901    // Get the new insert position for the node we care about.
1902    VectorType *NewIP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1903    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1904  }
1905  VectorType *New = new (*this, TypeAlignment)
1906    VectorType(vecType, NumElts, Canonical, VecKind);
1907  VectorTypes.InsertNode(New, InsertPos);
1908  Types.push_back(New);
1909  return QualType(New, 0);
1910}
1911
1912/// getExtVectorType - Return the unique reference to an extended vector type of
1913/// the specified element type and size. VectorType must be a built-in type.
1914QualType
1915ASTContext::getExtVectorType(QualType vecType, unsigned NumElts) const {
1916  assert(vecType->isBuiltinType() || vecType->isDependentType());
1917
1918  // Check if we've already instantiated a vector of this type.
1919  llvm::FoldingSetNodeID ID;
1920  VectorType::Profile(ID, vecType, NumElts, Type::ExtVector,
1921                      VectorType::GenericVector);
1922  void *InsertPos = 0;
1923  if (VectorType *VTP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos))
1924    return QualType(VTP, 0);
1925
1926  // If the element type isn't canonical, this won't be a canonical type either,
1927  // so fill in the canonical type field.
1928  QualType Canonical;
1929  if (!vecType.isCanonical()) {
1930    Canonical = getExtVectorType(getCanonicalType(vecType), NumElts);
1931
1932    // Get the new insert position for the node we care about.
1933    VectorType *NewIP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1934    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
1935  }
1936  ExtVectorType *New = new (*this, TypeAlignment)
1937    ExtVectorType(vecType, NumElts, Canonical);
1938  VectorTypes.InsertNode(New, InsertPos);
1939  Types.push_back(New);
1940  return QualType(New, 0);
1941}
1942
1943QualType
1944ASTContext::getDependentSizedExtVectorType(QualType vecType,
1945                                           Expr *SizeExpr,
1946                                           SourceLocation AttrLoc) const {
1947  llvm::FoldingSetNodeID ID;
1948  DependentSizedExtVectorType::Profile(ID, *this, getCanonicalType(vecType),
1949                                       SizeExpr);
1950
1951  void *InsertPos = 0;
1952  DependentSizedExtVectorType *Canon
1953    = DependentSizedExtVectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1954  DependentSizedExtVectorType *New;
1955  if (Canon) {
1956    // We already have a canonical version of this array type; use it as
1957    // the canonical type for a newly-built type.
1958    New = new (*this, TypeAlignment)
1959      DependentSizedExtVectorType(*this, vecType, QualType(Canon, 0),
1960                                  SizeExpr, AttrLoc);
1961  } else {
1962    QualType CanonVecTy = getCanonicalType(vecType);
1963    if (CanonVecTy == vecType) {
1964      New = new (*this, TypeAlignment)
1965        DependentSizedExtVectorType(*this, vecType, QualType(), SizeExpr,
1966                                    AttrLoc);
1967
1968      DependentSizedExtVectorType *CanonCheck
1969        = DependentSizedExtVectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1970      assert(!CanonCheck && "Dependent-sized ext_vector canonical type broken");
1971      (void)CanonCheck;
1972      DependentSizedExtVectorTypes.InsertNode(New, InsertPos);
1973    } else {
1974      QualType Canon = getDependentSizedExtVectorType(CanonVecTy, SizeExpr,
1975                                                      SourceLocation());
1976      New = new (*this, TypeAlignment)
1977        DependentSizedExtVectorType(*this, vecType, Canon, SizeExpr, AttrLoc);
1978    }
1979  }
1980
1981  Types.push_back(New);
1982  return QualType(New, 0);
1983}
1984
1985/// getFunctionNoProtoType - Return a K&R style C function type like 'int()'.
1986///
1987QualType
1988ASTContext::getFunctionNoProtoType(QualType ResultTy,
1989                                   const FunctionType::ExtInfo &Info) const {
1990  const CallingConv DefaultCC = Info.getCC();
1991  const CallingConv CallConv = (LangOpts.MRTD && DefaultCC == CC_Default) ?
1992                               CC_X86StdCall : DefaultCC;
1993  // Unique functions, to guarantee there is only one function of a particular
1994  // structure.
1995  llvm::FoldingSetNodeID ID;
1996  FunctionNoProtoType::Profile(ID, ResultTy, Info);
1997
1998  void *InsertPos = 0;
1999  if (FunctionNoProtoType *FT =
2000        FunctionNoProtoTypes.FindNodeOrInsertPos(ID, InsertPos))
2001    return QualType(FT, 0);
2002
2003  QualType Canonical;
2004  if (!ResultTy.isCanonical() ||
2005      getCanonicalCallConv(CallConv) != CallConv) {
2006    Canonical =
2007      getFunctionNoProtoType(getCanonicalType(ResultTy),
2008                     Info.withCallingConv(getCanonicalCallConv(CallConv)));
2009
2010    // Get the new insert position for the node we care about.
2011    FunctionNoProtoType *NewIP =
2012      FunctionNoProtoTypes.FindNodeOrInsertPos(ID, InsertPos);
2013    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
2014  }
2015
2016  FunctionProtoType::ExtInfo newInfo = Info.withCallingConv(CallConv);
2017  FunctionNoProtoType *New = new (*this, TypeAlignment)
2018    FunctionNoProtoType(ResultTy, Canonical, newInfo);
2019  Types.push_back(New);
2020  FunctionNoProtoTypes.InsertNode(New, InsertPos);
2021  return QualType(New, 0);
2022}
2023
2024/// getFunctionType - Return a normal function type with a typed argument
2025/// list.  isVariadic indicates whether the argument list includes '...'.
2026QualType
2027ASTContext::getFunctionType(QualType ResultTy,
2028                            const QualType *ArgArray, unsigned NumArgs,
2029                            const FunctionProtoType::ExtProtoInfo &EPI) const {
2030  // Unique functions, to guarantee there is only one function of a particular
2031  // structure.
2032  llvm::FoldingSetNodeID ID;
2033  FunctionProtoType::Profile(ID, ResultTy, ArgArray, NumArgs, EPI, *this);
2034
2035  void *InsertPos = 0;
2036  if (FunctionProtoType *FTP =
2037        FunctionProtoTypes.FindNodeOrInsertPos(ID, InsertPos))
2038    return QualType(FTP, 0);
2039
2040  // Determine whether the type being created is already canonical or not.
2041  bool isCanonical= EPI.ExceptionSpecType == EST_None && ResultTy.isCanonical();
2042  for (unsigned i = 0; i != NumArgs && isCanonical; ++i)
2043    if (!ArgArray[i].isCanonicalAsParam())
2044      isCanonical = false;
2045
2046  const CallingConv DefaultCC = EPI.ExtInfo.getCC();
2047  const CallingConv CallConv = (LangOpts.MRTD && DefaultCC == CC_Default) ?
2048                               CC_X86StdCall : DefaultCC;
2049
2050  // If this type isn't canonical, get the canonical version of it.
2051  // The exception spec is not part of the canonical type.
2052  QualType Canonical;
2053  if (!isCanonical || getCanonicalCallConv(CallConv) != CallConv) {
2054    SmallVector<QualType, 16> CanonicalArgs;
2055    CanonicalArgs.reserve(NumArgs);
2056    for (unsigned i = 0; i != NumArgs; ++i)
2057      CanonicalArgs.push_back(getCanonicalParamType(ArgArray[i]));
2058
2059    FunctionProtoType::ExtProtoInfo CanonicalEPI = EPI;
2060    CanonicalEPI.ExceptionSpecType = EST_None;
2061    CanonicalEPI.NumExceptions = 0;
2062    CanonicalEPI.ExtInfo
2063      = CanonicalEPI.ExtInfo.withCallingConv(getCanonicalCallConv(CallConv));
2064
2065    Canonical = getFunctionType(getCanonicalType(ResultTy),
2066                                CanonicalArgs.data(), NumArgs,
2067                                CanonicalEPI);
2068
2069    // Get the new insert position for the node we care about.
2070    FunctionProtoType *NewIP =
2071      FunctionProtoTypes.FindNodeOrInsertPos(ID, InsertPos);
2072    assert(NewIP == 0 && "Shouldn't be in the map!"); (void)NewIP;
2073  }
2074
2075  // FunctionProtoType objects are allocated with extra bytes after
2076  // them for three variable size arrays at the end:
2077  //  - parameter types
2078  //  - exception types
2079  //  - consumed-arguments flags
2080  // Instead of the exception types, there could be a noexcept
2081  // expression.
2082  size_t Size = sizeof(FunctionProtoType) +
2083                NumArgs * sizeof(QualType);
2084  if (EPI.ExceptionSpecType == EST_Dynamic)
2085    Size += EPI.NumExceptions * sizeof(QualType);
2086  else if (EPI.ExceptionSpecType == EST_ComputedNoexcept) {
2087    Size += sizeof(Expr*);
2088  }
2089  if (EPI.ConsumedArguments)
2090    Size += NumArgs * sizeof(bool);
2091
2092  FunctionProtoType *FTP = (FunctionProtoType*) Allocate(Size, TypeAlignment);
2093  FunctionProtoType::ExtProtoInfo newEPI = EPI;
2094  newEPI.ExtInfo = EPI.ExtInfo.withCallingConv(CallConv);
2095  new (FTP) FunctionProtoType(ResultTy, ArgArray, NumArgs, Canonical, newEPI);
2096  Types.push_back(FTP);
2097  FunctionProtoTypes.InsertNode(FTP, InsertPos);
2098  return QualType(FTP, 0);
2099}
2100
2101#ifndef NDEBUG
2102static bool NeedsInjectedClassNameType(const RecordDecl *D) {
2103  if (!isa<CXXRecordDecl>(D)) return false;
2104  const CXXRecordDecl *RD = cast<CXXRecordDecl>(D);
2105  if (isa<ClassTemplatePartialSpecializationDecl>(RD))
2106    return true;
2107  if (RD->getDescribedClassTemplate() &&
2108      !isa<ClassTemplateSpecializationDecl>(RD))
2109    return true;
2110  return false;
2111}
2112#endif
2113
2114/// getInjectedClassNameType - Return the unique reference to the
2115/// injected class name type for the specified templated declaration.
2116QualType ASTContext::getInjectedClassNameType(CXXRecordDecl *Decl,
2117                                              QualType TST) const {
2118  assert(NeedsInjectedClassNameType(Decl));
2119  if (Decl->TypeForDecl) {
2120    assert(isa<InjectedClassNameType>(Decl->TypeForDecl));
2121  } else if (CXXRecordDecl *PrevDecl = Decl->getPreviousDeclaration()) {
2122    assert(PrevDecl->TypeForDecl && "previous declaration has no type");
2123    Decl->TypeForDecl = PrevDecl->TypeForDecl;
2124    assert(isa<InjectedClassNameType>(Decl->TypeForDecl));
2125  } else {
2126    Type *newType =
2127      new (*this, TypeAlignment) InjectedClassNameType(Decl, TST);
2128    Decl->TypeForDecl = newType;
2129    Types.push_back(newType);
2130  }
2131  return QualType(Decl->TypeForDecl, 0);
2132}
2133
2134/// getTypeDeclType - Return the unique reference to the type for the
2135/// specified type declaration.
2136QualType ASTContext::getTypeDeclTypeSlow(const TypeDecl *Decl) const {
2137  assert(Decl && "Passed null for Decl param");
2138  assert(!Decl->TypeForDecl && "TypeForDecl present in slow case");
2139
2140  if (const TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Decl))
2141    return getTypedefType(Typedef);
2142
2143  assert(!isa<TemplateTypeParmDecl>(Decl) &&
2144         "Template type parameter types are always available.");
2145
2146  if (const RecordDecl *Record = dyn_cast<RecordDecl>(Decl)) {
2147    assert(!Record->getPreviousDeclaration() &&
2148           "struct/union has previous declaration");
2149    assert(!NeedsInjectedClassNameType(Record));
2150    return getRecordType(Record);
2151  } else if (const EnumDecl *Enum = dyn_cast<EnumDecl>(Decl)) {
2152    assert(!Enum->getPreviousDeclaration() &&
2153           "enum has previous declaration");
2154    return getEnumType(Enum);
2155  } else if (const UnresolvedUsingTypenameDecl *Using =
2156               dyn_cast<UnresolvedUsingTypenameDecl>(Decl)) {
2157    Type *newType = new (*this, TypeAlignment) UnresolvedUsingType(Using);
2158    Decl->TypeForDecl = newType;
2159    Types.push_back(newType);
2160  } else
2161    llvm_unreachable("TypeDecl without a type?");
2162
2163  return QualType(Decl->TypeForDecl, 0);
2164}
2165
2166/// getTypedefType - Return the unique reference to the type for the
2167/// specified typedef name decl.
2168QualType
2169ASTContext::getTypedefType(const TypedefNameDecl *Decl,
2170                           QualType Canonical) const {
2171  if (Decl->TypeForDecl) return QualType(Decl->TypeForDecl, 0);
2172
2173  if (Canonical.isNull())
2174    Canonical = getCanonicalType(Decl->getUnderlyingType());
2175  TypedefType *newType = new(*this, TypeAlignment)
2176    TypedefType(Type::Typedef, Decl, Canonical);
2177  Decl->TypeForDecl = newType;
2178  Types.push_back(newType);
2179  return QualType(newType, 0);
2180}
2181
2182QualType ASTContext::getRecordType(const RecordDecl *Decl) const {
2183  if (Decl->TypeForDecl) return QualType(Decl->TypeForDecl, 0);
2184
2185  if (const RecordDecl *PrevDecl = Decl->getPreviousDeclaration())
2186    if (PrevDecl->TypeForDecl)
2187      return QualType(Decl->TypeForDecl = PrevDecl->TypeForDecl, 0);
2188
2189  RecordType *newType = new (*this, TypeAlignment) RecordType(Decl);
2190  Decl->TypeForDecl = newType;
2191  Types.push_back(newType);
2192  return QualType(newType, 0);
2193}
2194
2195QualType ASTContext::getEnumType(const EnumDecl *Decl) const {
2196  if (Decl->TypeForDecl) return QualType(Decl->TypeForDecl, 0);
2197
2198  if (const EnumDecl *PrevDecl = Decl->getPreviousDeclaration())
2199    if (PrevDecl->TypeForDecl)
2200      return QualType(Decl->TypeForDecl = PrevDecl->TypeForDecl, 0);
2201
2202  EnumType *newType = new (*this, TypeAlignment) EnumType(Decl);
2203  Decl->TypeForDecl = newType;
2204  Types.push_back(newType);
2205  return QualType(newType, 0);
2206}
2207
2208QualType ASTContext::getAttributedType(AttributedType::Kind attrKind,
2209                                       QualType modifiedType,
2210                                       QualType equivalentType) {
2211  llvm::FoldingSetNodeID id;
2212  AttributedType::Profile(id, attrKind, modifiedType, equivalentType);
2213
2214  void *insertPos = 0;
2215  AttributedType *type = AttributedTypes.FindNodeOrInsertPos(id, insertPos);
2216  if (type) return QualType(type, 0);
2217
2218  QualType canon = getCanonicalType(equivalentType);
2219  type = new (*this, TypeAlignment)
2220           AttributedType(canon, attrKind, modifiedType, equivalentType);
2221
2222  Types.push_back(type);
2223  AttributedTypes.InsertNode(type, insertPos);
2224
2225  return QualType(type, 0);
2226}
2227
2228
2229/// \brief Retrieve a substitution-result type.
2230QualType
2231ASTContext::getSubstTemplateTypeParmType(const TemplateTypeParmType *Parm,
2232                                         QualType Replacement) const {
2233  assert(Replacement.isCanonical()
2234         && "replacement types must always be canonical");
2235
2236  llvm::FoldingSetNodeID ID;
2237  SubstTemplateTypeParmType::Profile(ID, Parm, Replacement);
2238  void *InsertPos = 0;
2239  SubstTemplateTypeParmType *SubstParm
2240    = SubstTemplateTypeParmTypes.FindNodeOrInsertPos(ID, InsertPos);
2241
2242  if (!SubstParm) {
2243    SubstParm = new (*this, TypeAlignment)
2244      SubstTemplateTypeParmType(Parm, Replacement);
2245    Types.push_back(SubstParm);
2246    SubstTemplateTypeParmTypes.InsertNode(SubstParm, InsertPos);
2247  }
2248
2249  return QualType(SubstParm, 0);
2250}
2251
2252/// \brief Retrieve a
2253QualType ASTContext::getSubstTemplateTypeParmPackType(
2254                                          const TemplateTypeParmType *Parm,
2255                                              const TemplateArgument &ArgPack) {
2256#ifndef NDEBUG
2257  for (TemplateArgument::pack_iterator P = ArgPack.pack_begin(),
2258                                    PEnd = ArgPack.pack_end();
2259       P != PEnd; ++P) {
2260    assert(P->getKind() == TemplateArgument::Type &&"Pack contains a non-type");
2261    assert(P->getAsType().isCanonical() && "Pack contains non-canonical type");
2262  }
2263#endif
2264
2265  llvm::FoldingSetNodeID ID;
2266  SubstTemplateTypeParmPackType::Profile(ID, Parm, ArgPack);
2267  void *InsertPos = 0;
2268  if (SubstTemplateTypeParmPackType *SubstParm
2269        = SubstTemplateTypeParmPackTypes.FindNodeOrInsertPos(ID, InsertPos))
2270    return QualType(SubstParm, 0);
2271
2272  QualType Canon;
2273  if (!Parm->isCanonicalUnqualified()) {
2274    Canon = getCanonicalType(QualType(Parm, 0));
2275    Canon = getSubstTemplateTypeParmPackType(cast<TemplateTypeParmType>(Canon),
2276                                             ArgPack);
2277    SubstTemplateTypeParmPackTypes.FindNodeOrInsertPos(ID, InsertPos);
2278  }
2279
2280  SubstTemplateTypeParmPackType *SubstParm
2281    = new (*this, TypeAlignment) SubstTemplateTypeParmPackType(Parm, Canon,
2282                                                               ArgPack);
2283  Types.push_back(SubstParm);
2284  SubstTemplateTypeParmTypes.InsertNode(SubstParm, InsertPos);
2285  return QualType(SubstParm, 0);
2286}
2287
2288/// \brief Retrieve the template type parameter type for a template
2289/// parameter or parameter pack with the given depth, index, and (optionally)
2290/// name.
2291QualType ASTContext::getTemplateTypeParmType(unsigned Depth, unsigned Index,
2292                                             bool ParameterPack,
2293                                             TemplateTypeParmDecl *TTPDecl) const {
2294  llvm::FoldingSetNodeID ID;
2295  TemplateTypeParmType::Profile(ID, Depth, Index, ParameterPack, TTPDecl);
2296  void *InsertPos = 0;
2297  TemplateTypeParmType *TypeParm
2298    = TemplateTypeParmTypes.FindNodeOrInsertPos(ID, InsertPos);
2299
2300  if (TypeParm)
2301    return QualType(TypeParm, 0);
2302
2303  if (TTPDecl) {
2304    QualType Canon = getTemplateTypeParmType(Depth, Index, ParameterPack);
2305    TypeParm = new (*this, TypeAlignment) TemplateTypeParmType(TTPDecl, Canon);
2306
2307    TemplateTypeParmType *TypeCheck
2308      = TemplateTypeParmTypes.FindNodeOrInsertPos(ID, InsertPos);
2309    assert(!TypeCheck && "Template type parameter canonical type broken");
2310    (void)TypeCheck;
2311  } else
2312    TypeParm = new (*this, TypeAlignment)
2313      TemplateTypeParmType(Depth, Index, ParameterPack);
2314
2315  Types.push_back(TypeParm);
2316  TemplateTypeParmTypes.InsertNode(TypeParm, InsertPos);
2317
2318  return QualType(TypeParm, 0);
2319}
2320
2321TypeSourceInfo *
2322ASTContext::getTemplateSpecializationTypeInfo(TemplateName Name,
2323                                              SourceLocation NameLoc,
2324                                        const TemplateArgumentListInfo &Args,
2325                                              QualType Underlying) const {
2326  assert(!Name.getAsDependentTemplateName() &&
2327         "No dependent template names here!");
2328  QualType TST = getTemplateSpecializationType(Name, Args, Underlying);
2329
2330  TypeSourceInfo *DI = CreateTypeSourceInfo(TST);
2331  TemplateSpecializationTypeLoc TL
2332    = cast<TemplateSpecializationTypeLoc>(DI->getTypeLoc());
2333  TL.setTemplateNameLoc(NameLoc);
2334  TL.setLAngleLoc(Args.getLAngleLoc());
2335  TL.setRAngleLoc(Args.getRAngleLoc());
2336  for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
2337    TL.setArgLocInfo(i, Args[i].getLocInfo());
2338  return DI;
2339}
2340
2341QualType
2342ASTContext::getTemplateSpecializationType(TemplateName Template,
2343                                          const TemplateArgumentListInfo &Args,
2344                                          QualType Underlying) const {
2345  assert(!Template.getAsDependentTemplateName() &&
2346         "No dependent template names here!");
2347
2348  unsigned NumArgs = Args.size();
2349
2350  SmallVector<TemplateArgument, 4> ArgVec;
2351  ArgVec.reserve(NumArgs);
2352  for (unsigned i = 0; i != NumArgs; ++i)
2353    ArgVec.push_back(Args[i].getArgument());
2354
2355  return getTemplateSpecializationType(Template, ArgVec.data(), NumArgs,
2356                                       Underlying);
2357}
2358
2359QualType
2360ASTContext::getTemplateSpecializationType(TemplateName Template,
2361                                          const TemplateArgument *Args,
2362                                          unsigned NumArgs,
2363                                          QualType Underlying) const {
2364  assert(!Template.getAsDependentTemplateName() &&
2365         "No dependent template names here!");
2366  // Look through qualified template names.
2367  if (QualifiedTemplateName *QTN = Template.getAsQualifiedTemplateName())
2368    Template = TemplateName(QTN->getTemplateDecl());
2369
2370  bool isTypeAlias =
2371    Template.getAsTemplateDecl() &&
2372    isa<TypeAliasTemplateDecl>(Template.getAsTemplateDecl());
2373
2374  QualType CanonType;
2375  if (!Underlying.isNull())
2376    CanonType = getCanonicalType(Underlying);
2377  else {
2378    assert(!isTypeAlias &&
2379           "Underlying type for template alias must be computed by caller");
2380    CanonType = getCanonicalTemplateSpecializationType(Template, Args,
2381                                                       NumArgs);
2382  }
2383
2384  // Allocate the (non-canonical) template specialization type, but don't
2385  // try to unique it: these types typically have location information that
2386  // we don't unique and don't want to lose.
2387  void *Mem = Allocate(sizeof(TemplateSpecializationType) +
2388                       sizeof(TemplateArgument) * NumArgs +
2389                       (isTypeAlias ? sizeof(QualType) : 0),
2390                       TypeAlignment);
2391  TemplateSpecializationType *Spec
2392    = new (Mem) TemplateSpecializationType(Template,
2393                                           Args, NumArgs,
2394                                           CanonType,
2395                                         isTypeAlias ? Underlying : QualType());
2396
2397  Types.push_back(Spec);
2398  return QualType(Spec, 0);
2399}
2400
2401QualType
2402ASTContext::getCanonicalTemplateSpecializationType(TemplateName Template,
2403                                                   const TemplateArgument *Args,
2404                                                   unsigned NumArgs) const {
2405  assert(!Template.getAsDependentTemplateName() &&
2406         "No dependent template names here!");
2407  assert((!Template.getAsTemplateDecl() ||
2408          !isa<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) &&
2409         "Underlying type for template alias must be computed by caller");
2410
2411  // Look through qualified template names.
2412  if (QualifiedTemplateName *QTN = Template.getAsQualifiedTemplateName())
2413    Template = TemplateName(QTN->getTemplateDecl());
2414
2415  // Build the canonical template specialization type.
2416  TemplateName CanonTemplate = getCanonicalTemplateName(Template);
2417  SmallVector<TemplateArgument, 4> CanonArgs;
2418  CanonArgs.reserve(NumArgs);
2419  for (unsigned I = 0; I != NumArgs; ++I)
2420    CanonArgs.push_back(getCanonicalTemplateArgument(Args[I]));
2421
2422  // Determine whether this canonical template specialization type already
2423  // exists.
2424  llvm::FoldingSetNodeID ID;
2425  TemplateSpecializationType::Profile(ID, CanonTemplate,
2426                                      CanonArgs.data(), NumArgs, *this);
2427
2428  void *InsertPos = 0;
2429  TemplateSpecializationType *Spec
2430    = TemplateSpecializationTypes.FindNodeOrInsertPos(ID, InsertPos);
2431
2432  if (!Spec) {
2433    // Allocate a new canonical template specialization type.
2434    void *Mem = Allocate((sizeof(TemplateSpecializationType) +
2435                          sizeof(TemplateArgument) * NumArgs),
2436                         TypeAlignment);
2437    Spec = new (Mem) TemplateSpecializationType(CanonTemplate,
2438                                                CanonArgs.data(), NumArgs,
2439                                                QualType(), QualType());
2440    Types.push_back(Spec);
2441    TemplateSpecializationTypes.InsertNode(Spec, InsertPos);
2442  }
2443
2444  assert(Spec->isDependentType() &&
2445         "Non-dependent template-id type must have a canonical type");
2446  return QualType(Spec, 0);
2447}
2448
2449QualType
2450ASTContext::getElaboratedType(ElaboratedTypeKeyword Keyword,
2451                              NestedNameSpecifier *NNS,
2452                              QualType NamedType) const {
2453  llvm::FoldingSetNodeID ID;
2454  ElaboratedType::Profile(ID, Keyword, NNS, NamedType);
2455
2456  void *InsertPos = 0;
2457  ElaboratedType *T = ElaboratedTypes.FindNodeOrInsertPos(ID, InsertPos);
2458  if (T)
2459    return QualType(T, 0);
2460
2461  QualType Canon = NamedType;
2462  if (!Canon.isCanonical()) {
2463    Canon = getCanonicalType(NamedType);
2464    ElaboratedType *CheckT = ElaboratedTypes.FindNodeOrInsertPos(ID, InsertPos);
2465    assert(!CheckT && "Elaborated canonical type broken");
2466    (void)CheckT;
2467  }
2468
2469  T = new (*this) ElaboratedType(Keyword, NNS, NamedType, Canon);
2470  Types.push_back(T);
2471  ElaboratedTypes.InsertNode(T, InsertPos);
2472  return QualType(T, 0);
2473}
2474
2475QualType
2476ASTContext::getParenType(QualType InnerType) const {
2477  llvm::FoldingSetNodeID ID;
2478  ParenType::Profile(ID, InnerType);
2479
2480  void *InsertPos = 0;
2481  ParenType *T = ParenTypes.FindNodeOrInsertPos(ID, InsertPos);
2482  if (T)
2483    return QualType(T, 0);
2484
2485  QualType Canon = InnerType;
2486  if (!Canon.isCanonical()) {
2487    Canon = getCanonicalType(InnerType);
2488    ParenType *CheckT = ParenTypes.FindNodeOrInsertPos(ID, InsertPos);
2489    assert(!CheckT && "Paren canonical type broken");
2490    (void)CheckT;
2491  }
2492
2493  T = new (*this) ParenType(InnerType, Canon);
2494  Types.push_back(T);
2495  ParenTypes.InsertNode(T, InsertPos);
2496  return QualType(T, 0);
2497}
2498
2499QualType ASTContext::getDependentNameType(ElaboratedTypeKeyword Keyword,
2500                                          NestedNameSpecifier *NNS,
2501                                          const IdentifierInfo *Name,
2502                                          QualType Canon) const {
2503  assert(NNS->isDependent() && "nested-name-specifier must be dependent");
2504
2505  if (Canon.isNull()) {
2506    NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
2507    ElaboratedTypeKeyword CanonKeyword = Keyword;
2508    if (Keyword == ETK_None)
2509      CanonKeyword = ETK_Typename;
2510
2511    if (CanonNNS != NNS || CanonKeyword != Keyword)
2512      Canon = getDependentNameType(CanonKeyword, CanonNNS, Name);
2513  }
2514
2515  llvm::FoldingSetNodeID ID;
2516  DependentNameType::Profile(ID, Keyword, NNS, Name);
2517
2518  void *InsertPos = 0;
2519  DependentNameType *T
2520    = DependentNameTypes.FindNodeOrInsertPos(ID, InsertPos);
2521  if (T)
2522    return QualType(T, 0);
2523
2524  T = new (*this) DependentNameType(Keyword, NNS, Name, Canon);
2525  Types.push_back(T);
2526  DependentNameTypes.InsertNode(T, InsertPos);
2527  return QualType(T, 0);
2528}
2529
2530QualType
2531ASTContext::getDependentTemplateSpecializationType(
2532                                 ElaboratedTypeKeyword Keyword,
2533                                 NestedNameSpecifier *NNS,
2534                                 const IdentifierInfo *Name,
2535                                 const TemplateArgumentListInfo &Args) const {
2536  // TODO: avoid this copy
2537  SmallVector<TemplateArgument, 16> ArgCopy;
2538  for (unsigned I = 0, E = Args.size(); I != E; ++I)
2539    ArgCopy.push_back(Args[I].getArgument());
2540  return getDependentTemplateSpecializationType(Keyword, NNS, Name,
2541                                                ArgCopy.size(),
2542                                                ArgCopy.data());
2543}
2544
2545QualType
2546ASTContext::getDependentTemplateSpecializationType(
2547                                 ElaboratedTypeKeyword Keyword,
2548                                 NestedNameSpecifier *NNS,
2549                                 const IdentifierInfo *Name,
2550                                 unsigned NumArgs,
2551                                 const TemplateArgument *Args) const {
2552  assert((!NNS || NNS->isDependent()) &&
2553         "nested-name-specifier must be dependent");
2554
2555  llvm::FoldingSetNodeID ID;
2556  DependentTemplateSpecializationType::Profile(ID, *this, Keyword, NNS,
2557                                               Name, NumArgs, Args);
2558
2559  void *InsertPos = 0;
2560  DependentTemplateSpecializationType *T
2561    = DependentTemplateSpecializationTypes.FindNodeOrInsertPos(ID, InsertPos);
2562  if (T)
2563    return QualType(T, 0);
2564
2565  NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
2566
2567  ElaboratedTypeKeyword CanonKeyword = Keyword;
2568  if (Keyword == ETK_None) CanonKeyword = ETK_Typename;
2569
2570  bool AnyNonCanonArgs = false;
2571  SmallVector<TemplateArgument, 16> CanonArgs(NumArgs);
2572  for (unsigned I = 0; I != NumArgs; ++I) {
2573    CanonArgs[I] = getCanonicalTemplateArgument(Args[I]);
2574    if (!CanonArgs[I].structurallyEquals(Args[I]))
2575      AnyNonCanonArgs = true;
2576  }
2577
2578  QualType Canon;
2579  if (AnyNonCanonArgs || CanonNNS != NNS || CanonKeyword != Keyword) {
2580    Canon = getDependentTemplateSpecializationType(CanonKeyword, CanonNNS,
2581                                                   Name, NumArgs,
2582                                                   CanonArgs.data());
2583
2584    // Find the insert position again.
2585    DependentTemplateSpecializationTypes.FindNodeOrInsertPos(ID, InsertPos);
2586  }
2587
2588  void *Mem = Allocate((sizeof(DependentTemplateSpecializationType) +
2589                        sizeof(TemplateArgument) * NumArgs),
2590                       TypeAlignment);
2591  T = new (Mem) DependentTemplateSpecializationType(Keyword, NNS,
2592                                                    Name, NumArgs, Args, Canon);
2593  Types.push_back(T);
2594  DependentTemplateSpecializationTypes.InsertNode(T, InsertPos);
2595  return QualType(T, 0);
2596}
2597
2598QualType ASTContext::getPackExpansionType(QualType Pattern,
2599                                      llvm::Optional<unsigned> NumExpansions) {
2600  llvm::FoldingSetNodeID ID;
2601  PackExpansionType::Profile(ID, Pattern, NumExpansions);
2602
2603  assert(Pattern->containsUnexpandedParameterPack() &&
2604         "Pack expansions must expand one or more parameter packs");
2605  void *InsertPos = 0;
2606  PackExpansionType *T
2607    = PackExpansionTypes.FindNodeOrInsertPos(ID, InsertPos);
2608  if (T)
2609    return QualType(T, 0);
2610
2611  QualType Canon;
2612  if (!Pattern.isCanonical()) {
2613    Canon = getPackExpansionType(getCanonicalType(Pattern), NumExpansions);
2614
2615    // Find the insert position again.
2616    PackExpansionTypes.FindNodeOrInsertPos(ID, InsertPos);
2617  }
2618
2619  T = new (*this) PackExpansionType(Pattern, Canon, NumExpansions);
2620  Types.push_back(T);
2621  PackExpansionTypes.InsertNode(T, InsertPos);
2622  return QualType(T, 0);
2623}
2624
2625/// CmpProtocolNames - Comparison predicate for sorting protocols
2626/// alphabetically.
2627static bool CmpProtocolNames(const ObjCProtocolDecl *LHS,
2628                            const ObjCProtocolDecl *RHS) {
2629  return LHS->getDeclName() < RHS->getDeclName();
2630}
2631
2632static bool areSortedAndUniqued(ObjCProtocolDecl * const *Protocols,
2633                                unsigned NumProtocols) {
2634  if (NumProtocols == 0) return true;
2635
2636  for (unsigned i = 1; i != NumProtocols; ++i)
2637    if (!CmpProtocolNames(Protocols[i-1], Protocols[i]))
2638      return false;
2639  return true;
2640}
2641
2642static void SortAndUniqueProtocols(ObjCProtocolDecl **Protocols,
2643                                   unsigned &NumProtocols) {
2644  ObjCProtocolDecl **ProtocolsEnd = Protocols+NumProtocols;
2645
2646  // Sort protocols, keyed by name.
2647  std::sort(Protocols, Protocols+NumProtocols, CmpProtocolNames);
2648
2649  // Remove duplicates.
2650  ProtocolsEnd = std::unique(Protocols, ProtocolsEnd);
2651  NumProtocols = ProtocolsEnd-Protocols;
2652}
2653
2654QualType ASTContext::getObjCObjectType(QualType BaseType,
2655                                       ObjCProtocolDecl * const *Protocols,
2656                                       unsigned NumProtocols) const {
2657  // If the base type is an interface and there aren't any protocols
2658  // to add, then the interface type will do just fine.
2659  if (!NumProtocols && isa<ObjCInterfaceType>(BaseType))
2660    return BaseType;
2661
2662  // Look in the folding set for an existing type.
2663  llvm::FoldingSetNodeID ID;
2664  ObjCObjectTypeImpl::Profile(ID, BaseType, Protocols, NumProtocols);
2665  void *InsertPos = 0;
2666  if (ObjCObjectType *QT = ObjCObjectTypes.FindNodeOrInsertPos(ID, InsertPos))
2667    return QualType(QT, 0);
2668
2669  // Build the canonical type, which has the canonical base type and
2670  // a sorted-and-uniqued list of protocols.
2671  QualType Canonical;
2672  bool ProtocolsSorted = areSortedAndUniqued(Protocols, NumProtocols);
2673  if (!ProtocolsSorted || !BaseType.isCanonical()) {
2674    if (!ProtocolsSorted) {
2675      SmallVector<ObjCProtocolDecl*, 8> Sorted(Protocols,
2676                                                     Protocols + NumProtocols);
2677      unsigned UniqueCount = NumProtocols;
2678
2679      SortAndUniqueProtocols(&Sorted[0], UniqueCount);
2680      Canonical = getObjCObjectType(getCanonicalType(BaseType),
2681                                    &Sorted[0], UniqueCount);
2682    } else {
2683      Canonical = getObjCObjectType(getCanonicalType(BaseType),
2684                                    Protocols, NumProtocols);
2685    }
2686
2687    // Regenerate InsertPos.
2688    ObjCObjectTypes.FindNodeOrInsertPos(ID, InsertPos);
2689  }
2690
2691  unsigned Size = sizeof(ObjCObjectTypeImpl);
2692  Size += NumProtocols * sizeof(ObjCProtocolDecl *);
2693  void *Mem = Allocate(Size, TypeAlignment);
2694  ObjCObjectTypeImpl *T =
2695    new (Mem) ObjCObjectTypeImpl(Canonical, BaseType, Protocols, NumProtocols);
2696
2697  Types.push_back(T);
2698  ObjCObjectTypes.InsertNode(T, InsertPos);
2699  return QualType(T, 0);
2700}
2701
2702/// getObjCObjectPointerType - Return a ObjCObjectPointerType type for
2703/// the given object type.
2704QualType ASTContext::getObjCObjectPointerType(QualType ObjectT) const {
2705  llvm::FoldingSetNodeID ID;
2706  ObjCObjectPointerType::Profile(ID, ObjectT);
2707
2708  void *InsertPos = 0;
2709  if (ObjCObjectPointerType *QT =
2710              ObjCObjectPointerTypes.FindNodeOrInsertPos(ID, InsertPos))
2711    return QualType(QT, 0);
2712
2713  // Find the canonical object type.
2714  QualType Canonical;
2715  if (!ObjectT.isCanonical()) {
2716    Canonical = getObjCObjectPointerType(getCanonicalType(ObjectT));
2717
2718    // Regenerate InsertPos.
2719    ObjCObjectPointerTypes.FindNodeOrInsertPos(ID, InsertPos);
2720  }
2721
2722  // No match.
2723  void *Mem = Allocate(sizeof(ObjCObjectPointerType), TypeAlignment);
2724  ObjCObjectPointerType *QType =
2725    new (Mem) ObjCObjectPointerType(Canonical, ObjectT);
2726
2727  Types.push_back(QType);
2728  ObjCObjectPointerTypes.InsertNode(QType, InsertPos);
2729  return QualType(QType, 0);
2730}
2731
2732/// getObjCInterfaceType - Return the unique reference to the type for the
2733/// specified ObjC interface decl. The list of protocols is optional.
2734QualType ASTContext::getObjCInterfaceType(const ObjCInterfaceDecl *Decl) const {
2735  if (Decl->TypeForDecl)
2736    return QualType(Decl->TypeForDecl, 0);
2737
2738  // FIXME: redeclarations?
2739  void *Mem = Allocate(sizeof(ObjCInterfaceType), TypeAlignment);
2740  ObjCInterfaceType *T = new (Mem) ObjCInterfaceType(Decl);
2741  Decl->TypeForDecl = T;
2742  Types.push_back(T);
2743  return QualType(T, 0);
2744}
2745
2746/// getTypeOfExprType - Unlike many "get<Type>" functions, we can't unique
2747/// TypeOfExprType AST's (since expression's are never shared). For example,
2748/// multiple declarations that refer to "typeof(x)" all contain different
2749/// DeclRefExpr's. This doesn't effect the type checker, since it operates
2750/// on canonical type's (which are always unique).
2751QualType ASTContext::getTypeOfExprType(Expr *tofExpr) const {
2752  TypeOfExprType *toe;
2753  if (tofExpr->isTypeDependent()) {
2754    llvm::FoldingSetNodeID ID;
2755    DependentTypeOfExprType::Profile(ID, *this, tofExpr);
2756
2757    void *InsertPos = 0;
2758    DependentTypeOfExprType *Canon
2759      = DependentTypeOfExprTypes.FindNodeOrInsertPos(ID, InsertPos);
2760    if (Canon) {
2761      // We already have a "canonical" version of an identical, dependent
2762      // typeof(expr) type. Use that as our canonical type.
2763      toe = new (*this, TypeAlignment) TypeOfExprType(tofExpr,
2764                                          QualType((TypeOfExprType*)Canon, 0));
2765    }
2766    else {
2767      // Build a new, canonical typeof(expr) type.
2768      Canon
2769        = new (*this, TypeAlignment) DependentTypeOfExprType(*this, tofExpr);
2770      DependentTypeOfExprTypes.InsertNode(Canon, InsertPos);
2771      toe = Canon;
2772    }
2773  } else {
2774    QualType Canonical = getCanonicalType(tofExpr->getType());
2775    toe = new (*this, TypeAlignment) TypeOfExprType(tofExpr, Canonical);
2776  }
2777  Types.push_back(toe);
2778  return QualType(toe, 0);
2779}
2780
2781/// getTypeOfType -  Unlike many "get<Type>" functions, we don't unique
2782/// TypeOfType AST's. The only motivation to unique these nodes would be
2783/// memory savings. Since typeof(t) is fairly uncommon, space shouldn't be
2784/// an issue. This doesn't effect the type checker, since it operates
2785/// on canonical type's (which are always unique).
2786QualType ASTContext::getTypeOfType(QualType tofType) const {
2787  QualType Canonical = getCanonicalType(tofType);
2788  TypeOfType *tot = new (*this, TypeAlignment) TypeOfType(tofType, Canonical);
2789  Types.push_back(tot);
2790  return QualType(tot, 0);
2791}
2792
2793/// getDecltypeForExpr - Given an expr, will return the decltype for that
2794/// expression, according to the rules in C++0x [dcl.type.simple]p4
2795static QualType getDecltypeForExpr(const Expr *e, const ASTContext &Context) {
2796  if (e->isTypeDependent())
2797    return Context.DependentTy;
2798
2799  // If e is an id expression or a class member access, decltype(e) is defined
2800  // as the type of the entity named by e.
2801  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(e)) {
2802    if (const ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl()))
2803      return VD->getType();
2804  }
2805  if (const MemberExpr *ME = dyn_cast<MemberExpr>(e)) {
2806    if (const FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
2807      return FD->getType();
2808  }
2809  // If e is a function call or an invocation of an overloaded operator,
2810  // (parentheses around e are ignored), decltype(e) is defined as the
2811  // return type of that function.
2812  if (const CallExpr *CE = dyn_cast<CallExpr>(e->IgnoreParens()))
2813    return CE->getCallReturnType();
2814
2815  QualType T = e->getType();
2816
2817  // Otherwise, where T is the type of e, if e is an lvalue, decltype(e) is
2818  // defined as T&, otherwise decltype(e) is defined as T.
2819  if (e->isLValue())
2820    T = Context.getLValueReferenceType(T);
2821
2822  return T;
2823}
2824
2825/// getDecltypeType -  Unlike many "get<Type>" functions, we don't unique
2826/// DecltypeType AST's. The only motivation to unique these nodes would be
2827/// memory savings. Since decltype(t) is fairly uncommon, space shouldn't be
2828/// an issue. This doesn't effect the type checker, since it operates
2829/// on canonical type's (which are always unique).
2830QualType ASTContext::getDecltypeType(Expr *e) const {
2831  DecltypeType *dt;
2832
2833  // C++0x [temp.type]p2:
2834  //   If an expression e involves a template parameter, decltype(e) denotes a
2835  //   unique dependent type. Two such decltype-specifiers refer to the same
2836  //   type only if their expressions are equivalent (14.5.6.1).
2837  if (e->isInstantiationDependent()) {
2838    llvm::FoldingSetNodeID ID;
2839    DependentDecltypeType::Profile(ID, *this, e);
2840
2841    void *InsertPos = 0;
2842    DependentDecltypeType *Canon
2843      = DependentDecltypeTypes.FindNodeOrInsertPos(ID, InsertPos);
2844    if (Canon) {
2845      // We already have a "canonical" version of an equivalent, dependent
2846      // decltype type. Use that as our canonical type.
2847      dt = new (*this, TypeAlignment) DecltypeType(e, DependentTy,
2848                                       QualType((DecltypeType*)Canon, 0));
2849    }
2850    else {
2851      // Build a new, canonical typeof(expr) type.
2852      Canon = new (*this, TypeAlignment) DependentDecltypeType(*this, e);
2853      DependentDecltypeTypes.InsertNode(Canon, InsertPos);
2854      dt = Canon;
2855    }
2856  } else {
2857    QualType T = getDecltypeForExpr(e, *this);
2858    dt = new (*this, TypeAlignment) DecltypeType(e, T, getCanonicalType(T));
2859  }
2860  Types.push_back(dt);
2861  return QualType(dt, 0);
2862}
2863
2864/// getUnaryTransformationType - We don't unique these, since the memory
2865/// savings are minimal and these are rare.
2866QualType ASTContext::getUnaryTransformType(QualType BaseType,
2867                                           QualType UnderlyingType,
2868                                           UnaryTransformType::UTTKind Kind)
2869    const {
2870  UnaryTransformType *Ty =
2871    new (*this, TypeAlignment) UnaryTransformType (BaseType, UnderlyingType,
2872                                                   Kind,
2873                                 UnderlyingType->isDependentType() ?
2874                                    QualType() : UnderlyingType);
2875  Types.push_back(Ty);
2876  return QualType(Ty, 0);
2877}
2878
2879/// getAutoType - We only unique auto types after they've been deduced.
2880QualType ASTContext::getAutoType(QualType DeducedType) const {
2881  void *InsertPos = 0;
2882  if (!DeducedType.isNull()) {
2883    // Look in the folding set for an existing type.
2884    llvm::FoldingSetNodeID ID;
2885    AutoType::Profile(ID, DeducedType);
2886    if (AutoType *AT = AutoTypes.FindNodeOrInsertPos(ID, InsertPos))
2887      return QualType(AT, 0);
2888  }
2889
2890  AutoType *AT = new (*this, TypeAlignment) AutoType(DeducedType);
2891  Types.push_back(AT);
2892  if (InsertPos)
2893    AutoTypes.InsertNode(AT, InsertPos);
2894  return QualType(AT, 0);
2895}
2896
2897/// getAutoDeductType - Get type pattern for deducing against 'auto'.
2898QualType ASTContext::getAutoDeductType() const {
2899  if (AutoDeductTy.isNull())
2900    AutoDeductTy = getAutoType(QualType());
2901  assert(!AutoDeductTy.isNull() && "can't build 'auto' pattern");
2902  return AutoDeductTy;
2903}
2904
2905/// getAutoRRefDeductType - Get type pattern for deducing against 'auto &&'.
2906QualType ASTContext::getAutoRRefDeductType() const {
2907  if (AutoRRefDeductTy.isNull())
2908    AutoRRefDeductTy = getRValueReferenceType(getAutoDeductType());
2909  assert(!AutoRRefDeductTy.isNull() && "can't build 'auto &&' pattern");
2910  return AutoRRefDeductTy;
2911}
2912
2913/// getTagDeclType - Return the unique reference to the type for the
2914/// specified TagDecl (struct/union/class/enum) decl.
2915QualType ASTContext::getTagDeclType(const TagDecl *Decl) const {
2916  assert (Decl);
2917  // FIXME: What is the design on getTagDeclType when it requires casting
2918  // away const?  mutable?
2919  return getTypeDeclType(const_cast<TagDecl*>(Decl));
2920}
2921
2922/// getSizeType - Return the unique type for "size_t" (C99 7.17), the result
2923/// of the sizeof operator (C99 6.5.3.4p4). The value is target dependent and
2924/// needs to agree with the definition in <stddef.h>.
2925CanQualType ASTContext::getSizeType() const {
2926  return getFromTargetType(Target.getSizeType());
2927}
2928
2929/// getSignedWCharType - Return the type of "signed wchar_t".
2930/// Used when in C++, as a GCC extension.
2931QualType ASTContext::getSignedWCharType() const {
2932  // FIXME: derive from "Target" ?
2933  return WCharTy;
2934}
2935
2936/// getUnsignedWCharType - Return the type of "unsigned wchar_t".
2937/// Used when in C++, as a GCC extension.
2938QualType ASTContext::getUnsignedWCharType() const {
2939  // FIXME: derive from "Target" ?
2940  return UnsignedIntTy;
2941}
2942
2943/// getPointerDiffType - Return the unique type for "ptrdiff_t" (ref?)
2944/// defined in <stddef.h>. Pointer - pointer requires this (C99 6.5.6p9).
2945QualType ASTContext::getPointerDiffType() const {
2946  return getFromTargetType(Target.getPtrDiffType(0));
2947}
2948
2949//===----------------------------------------------------------------------===//
2950//                              Type Operators
2951//===----------------------------------------------------------------------===//
2952
2953CanQualType ASTContext::getCanonicalParamType(QualType T) const {
2954  // Push qualifiers into arrays, and then discard any remaining
2955  // qualifiers.
2956  T = getCanonicalType(T);
2957  T = getVariableArrayDecayedType(T);
2958  const Type *Ty = T.getTypePtr();
2959  QualType Result;
2960  if (isa<ArrayType>(Ty)) {
2961    Result = getArrayDecayedType(QualType(Ty,0));
2962  } else if (isa<FunctionType>(Ty)) {
2963    Result = getPointerType(QualType(Ty, 0));
2964  } else {
2965    Result = QualType(Ty, 0);
2966  }
2967
2968  return CanQualType::CreateUnsafe(Result);
2969}
2970
2971QualType ASTContext::getUnqualifiedArrayType(QualType type,
2972                                             Qualifiers &quals) {
2973  SplitQualType splitType = type.getSplitUnqualifiedType();
2974
2975  // FIXME: getSplitUnqualifiedType() actually walks all the way to
2976  // the unqualified desugared type and then drops it on the floor.
2977  // We then have to strip that sugar back off with
2978  // getUnqualifiedDesugaredType(), which is silly.
2979  const ArrayType *AT =
2980    dyn_cast<ArrayType>(splitType.first->getUnqualifiedDesugaredType());
2981
2982  // If we don't have an array, just use the results in splitType.
2983  if (!AT) {
2984    quals = splitType.second;
2985    return QualType(splitType.first, 0);
2986  }
2987
2988  // Otherwise, recurse on the array's element type.
2989  QualType elementType = AT->getElementType();
2990  QualType unqualElementType = getUnqualifiedArrayType(elementType, quals);
2991
2992  // If that didn't change the element type, AT has no qualifiers, so we
2993  // can just use the results in splitType.
2994  if (elementType == unqualElementType) {
2995    assert(quals.empty()); // from the recursive call
2996    quals = splitType.second;
2997    return QualType(splitType.first, 0);
2998  }
2999
3000  // Otherwise, add in the qualifiers from the outermost type, then
3001  // build the type back up.
3002  quals.addConsistentQualifiers(splitType.second);
3003
3004  if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT)) {
3005    return getConstantArrayType(unqualElementType, CAT->getSize(),
3006                                CAT->getSizeModifier(), 0);
3007  }
3008
3009  if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
3010    return getIncompleteArrayType(unqualElementType, IAT->getSizeModifier(), 0);
3011  }
3012
3013  if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(AT)) {
3014    return getVariableArrayType(unqualElementType,
3015                                VAT->getSizeExpr(),
3016                                VAT->getSizeModifier(),
3017                                VAT->getIndexTypeCVRQualifiers(),
3018                                VAT->getBracketsRange());
3019  }
3020
3021  const DependentSizedArrayType *DSAT = cast<DependentSizedArrayType>(AT);
3022  return getDependentSizedArrayType(unqualElementType, DSAT->getSizeExpr(),
3023                                    DSAT->getSizeModifier(), 0,
3024                                    SourceRange());
3025}
3026
3027/// UnwrapSimilarPointerTypes - If T1 and T2 are pointer types  that
3028/// may be similar (C++ 4.4), replaces T1 and T2 with the type that
3029/// they point to and return true. If T1 and T2 aren't pointer types
3030/// or pointer-to-member types, or if they are not similar at this
3031/// level, returns false and leaves T1 and T2 unchanged. Top-level
3032/// qualifiers on T1 and T2 are ignored. This function will typically
3033/// be called in a loop that successively "unwraps" pointer and
3034/// pointer-to-member types to compare them at each level.
3035bool ASTContext::UnwrapSimilarPointerTypes(QualType &T1, QualType &T2) {
3036  const PointerType *T1PtrType = T1->getAs<PointerType>(),
3037                    *T2PtrType = T2->getAs<PointerType>();
3038  if (T1PtrType && T2PtrType) {
3039    T1 = T1PtrType->getPointeeType();
3040    T2 = T2PtrType->getPointeeType();
3041    return true;
3042  }
3043
3044  const MemberPointerType *T1MPType = T1->getAs<MemberPointerType>(),
3045                          *T2MPType = T2->getAs<MemberPointerType>();
3046  if (T1MPType && T2MPType &&
3047      hasSameUnqualifiedType(QualType(T1MPType->getClass(), 0),
3048                             QualType(T2MPType->getClass(), 0))) {
3049    T1 = T1MPType->getPointeeType();
3050    T2 = T2MPType->getPointeeType();
3051    return true;
3052  }
3053
3054  if (getLangOptions().ObjC1) {
3055    const ObjCObjectPointerType *T1OPType = T1->getAs<ObjCObjectPointerType>(),
3056                                *T2OPType = T2->getAs<ObjCObjectPointerType>();
3057    if (T1OPType && T2OPType) {
3058      T1 = T1OPType->getPointeeType();
3059      T2 = T2OPType->getPointeeType();
3060      return true;
3061    }
3062  }
3063
3064  // FIXME: Block pointers, too?
3065
3066  return false;
3067}
3068
3069DeclarationNameInfo
3070ASTContext::getNameForTemplate(TemplateName Name,
3071                               SourceLocation NameLoc) const {
3072  switch (Name.getKind()) {
3073  case TemplateName::QualifiedTemplate:
3074  case TemplateName::Template:
3075    // DNInfo work in progress: CHECKME: what about DNLoc?
3076    return DeclarationNameInfo(Name.getAsTemplateDecl()->getDeclName(),
3077                               NameLoc);
3078
3079  case TemplateName::OverloadedTemplate: {
3080    OverloadedTemplateStorage *Storage = Name.getAsOverloadedTemplate();
3081    // DNInfo work in progress: CHECKME: what about DNLoc?
3082    return DeclarationNameInfo((*Storage->begin())->getDeclName(), NameLoc);
3083  }
3084
3085  case TemplateName::DependentTemplate: {
3086    DependentTemplateName *DTN = Name.getAsDependentTemplateName();
3087    DeclarationName DName;
3088    if (DTN->isIdentifier()) {
3089      DName = DeclarationNames.getIdentifier(DTN->getIdentifier());
3090      return DeclarationNameInfo(DName, NameLoc);
3091    } else {
3092      DName = DeclarationNames.getCXXOperatorName(DTN->getOperator());
3093      // DNInfo work in progress: FIXME: source locations?
3094      DeclarationNameLoc DNLoc;
3095      DNLoc.CXXOperatorName.BeginOpNameLoc = SourceLocation().getRawEncoding();
3096      DNLoc.CXXOperatorName.EndOpNameLoc = SourceLocation().getRawEncoding();
3097      return DeclarationNameInfo(DName, NameLoc, DNLoc);
3098    }
3099  }
3100
3101  case TemplateName::SubstTemplateTemplateParm: {
3102    SubstTemplateTemplateParmStorage *subst
3103      = Name.getAsSubstTemplateTemplateParm();
3104    return DeclarationNameInfo(subst->getParameter()->getDeclName(),
3105                               NameLoc);
3106  }
3107
3108  case TemplateName::SubstTemplateTemplateParmPack: {
3109    SubstTemplateTemplateParmPackStorage *subst
3110      = Name.getAsSubstTemplateTemplateParmPack();
3111    return DeclarationNameInfo(subst->getParameterPack()->getDeclName(),
3112                               NameLoc);
3113  }
3114  }
3115
3116  llvm_unreachable("bad template name kind!");
3117}
3118
3119TemplateName ASTContext::getCanonicalTemplateName(TemplateName Name) const {
3120  switch (Name.getKind()) {
3121  case TemplateName::QualifiedTemplate:
3122  case TemplateName::Template: {
3123    TemplateDecl *Template = Name.getAsTemplateDecl();
3124    if (TemplateTemplateParmDecl *TTP
3125          = dyn_cast<TemplateTemplateParmDecl>(Template))
3126      Template = getCanonicalTemplateTemplateParmDecl(TTP);
3127
3128    // The canonical template name is the canonical template declaration.
3129    return TemplateName(cast<TemplateDecl>(Template->getCanonicalDecl()));
3130  }
3131
3132  case TemplateName::OverloadedTemplate:
3133    llvm_unreachable("cannot canonicalize overloaded template");
3134
3135  case TemplateName::DependentTemplate: {
3136    DependentTemplateName *DTN = Name.getAsDependentTemplateName();
3137    assert(DTN && "Non-dependent template names must refer to template decls.");
3138    return DTN->CanonicalTemplateName;
3139  }
3140
3141  case TemplateName::SubstTemplateTemplateParm: {
3142    SubstTemplateTemplateParmStorage *subst
3143      = Name.getAsSubstTemplateTemplateParm();
3144    return getCanonicalTemplateName(subst->getReplacement());
3145  }
3146
3147  case TemplateName::SubstTemplateTemplateParmPack: {
3148    SubstTemplateTemplateParmPackStorage *subst
3149                                  = Name.getAsSubstTemplateTemplateParmPack();
3150    TemplateTemplateParmDecl *canonParameter
3151      = getCanonicalTemplateTemplateParmDecl(subst->getParameterPack());
3152    TemplateArgument canonArgPack
3153      = getCanonicalTemplateArgument(subst->getArgumentPack());
3154    return getSubstTemplateTemplateParmPack(canonParameter, canonArgPack);
3155  }
3156  }
3157
3158  llvm_unreachable("bad template name!");
3159}
3160
3161bool ASTContext::hasSameTemplateName(TemplateName X, TemplateName Y) {
3162  X = getCanonicalTemplateName(X);
3163  Y = getCanonicalTemplateName(Y);
3164  return X.getAsVoidPointer() == Y.getAsVoidPointer();
3165}
3166
3167TemplateArgument
3168ASTContext::getCanonicalTemplateArgument(const TemplateArgument &Arg) const {
3169  switch (Arg.getKind()) {
3170    case TemplateArgument::Null:
3171      return Arg;
3172
3173    case TemplateArgument::Expression:
3174      return Arg;
3175
3176    case TemplateArgument::Declaration:
3177      return TemplateArgument(Arg.getAsDecl()->getCanonicalDecl());
3178
3179    case TemplateArgument::Template:
3180      return TemplateArgument(getCanonicalTemplateName(Arg.getAsTemplate()));
3181
3182    case TemplateArgument::TemplateExpansion:
3183      return TemplateArgument(getCanonicalTemplateName(
3184                                         Arg.getAsTemplateOrTemplatePattern()),
3185                              Arg.getNumTemplateExpansions());
3186
3187    case TemplateArgument::Integral:
3188      return TemplateArgument(*Arg.getAsIntegral(),
3189                              getCanonicalType(Arg.getIntegralType()));
3190
3191    case TemplateArgument::Type:
3192      return TemplateArgument(getCanonicalType(Arg.getAsType()));
3193
3194    case TemplateArgument::Pack: {
3195      if (Arg.pack_size() == 0)
3196        return Arg;
3197
3198      TemplateArgument *CanonArgs
3199        = new (*this) TemplateArgument[Arg.pack_size()];
3200      unsigned Idx = 0;
3201      for (TemplateArgument::pack_iterator A = Arg.pack_begin(),
3202                                        AEnd = Arg.pack_end();
3203           A != AEnd; (void)++A, ++Idx)
3204        CanonArgs[Idx] = getCanonicalTemplateArgument(*A);
3205
3206      return TemplateArgument(CanonArgs, Arg.pack_size());
3207    }
3208  }
3209
3210  // Silence GCC warning
3211  assert(false && "Unhandled template argument kind");
3212  return TemplateArgument();
3213}
3214
3215NestedNameSpecifier *
3216ASTContext::getCanonicalNestedNameSpecifier(NestedNameSpecifier *NNS) const {
3217  if (!NNS)
3218    return 0;
3219
3220  switch (NNS->getKind()) {
3221  case NestedNameSpecifier::Identifier:
3222    // Canonicalize the prefix but keep the identifier the same.
3223    return NestedNameSpecifier::Create(*this,
3224                         getCanonicalNestedNameSpecifier(NNS->getPrefix()),
3225                                       NNS->getAsIdentifier());
3226
3227  case NestedNameSpecifier::Namespace:
3228    // A namespace is canonical; build a nested-name-specifier with
3229    // this namespace and no prefix.
3230    return NestedNameSpecifier::Create(*this, 0,
3231                                 NNS->getAsNamespace()->getOriginalNamespace());
3232
3233  case NestedNameSpecifier::NamespaceAlias:
3234    // A namespace is canonical; build a nested-name-specifier with
3235    // this namespace and no prefix.
3236    return NestedNameSpecifier::Create(*this, 0,
3237                                    NNS->getAsNamespaceAlias()->getNamespace()
3238                                                      ->getOriginalNamespace());
3239
3240  case NestedNameSpecifier::TypeSpec:
3241  case NestedNameSpecifier::TypeSpecWithTemplate: {
3242    QualType T = getCanonicalType(QualType(NNS->getAsType(), 0));
3243
3244    // If we have some kind of dependent-named type (e.g., "typename T::type"),
3245    // break it apart into its prefix and identifier, then reconsititute those
3246    // as the canonical nested-name-specifier. This is required to canonicalize
3247    // a dependent nested-name-specifier involving typedefs of dependent-name
3248    // types, e.g.,
3249    //   typedef typename T::type T1;
3250    //   typedef typename T1::type T2;
3251    if (const DependentNameType *DNT = T->getAs<DependentNameType>()) {
3252      NestedNameSpecifier *Prefix
3253        = getCanonicalNestedNameSpecifier(DNT->getQualifier());
3254      return NestedNameSpecifier::Create(*this, Prefix,
3255                           const_cast<IdentifierInfo *>(DNT->getIdentifier()));
3256    }
3257
3258    // Do the same thing as above, but with dependent-named specializations.
3259    if (const DependentTemplateSpecializationType *DTST
3260          = T->getAs<DependentTemplateSpecializationType>()) {
3261      NestedNameSpecifier *Prefix
3262        = getCanonicalNestedNameSpecifier(DTST->getQualifier());
3263
3264      T = getDependentTemplateSpecializationType(DTST->getKeyword(),
3265                                                 Prefix, DTST->getIdentifier(),
3266                                                 DTST->getNumArgs(),
3267                                                 DTST->getArgs());
3268      T = getCanonicalType(T);
3269    }
3270
3271    return NestedNameSpecifier::Create(*this, 0, false,
3272                                       const_cast<Type*>(T.getTypePtr()));
3273  }
3274
3275  case NestedNameSpecifier::Global:
3276    // The global specifier is canonical and unique.
3277    return NNS;
3278  }
3279
3280  // Required to silence a GCC warning
3281  return 0;
3282}
3283
3284
3285const ArrayType *ASTContext::getAsArrayType(QualType T) const {
3286  // Handle the non-qualified case efficiently.
3287  if (!T.hasLocalQualifiers()) {
3288    // Handle the common positive case fast.
3289    if (const ArrayType *AT = dyn_cast<ArrayType>(T))
3290      return AT;
3291  }
3292
3293  // Handle the common negative case fast.
3294  if (!isa<ArrayType>(T.getCanonicalType()))
3295    return 0;
3296
3297  // Apply any qualifiers from the array type to the element type.  This
3298  // implements C99 6.7.3p8: "If the specification of an array type includes
3299  // any type qualifiers, the element type is so qualified, not the array type."
3300
3301  // If we get here, we either have type qualifiers on the type, or we have
3302  // sugar such as a typedef in the way.  If we have type qualifiers on the type
3303  // we must propagate them down into the element type.
3304
3305  SplitQualType split = T.getSplitDesugaredType();
3306  Qualifiers qs = split.second;
3307
3308  // If we have a simple case, just return now.
3309  const ArrayType *ATy = dyn_cast<ArrayType>(split.first);
3310  if (ATy == 0 || qs.empty())
3311    return ATy;
3312
3313  // Otherwise, we have an array and we have qualifiers on it.  Push the
3314  // qualifiers into the array element type and return a new array type.
3315  QualType NewEltTy = getQualifiedType(ATy->getElementType(), qs);
3316
3317  if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(ATy))
3318    return cast<ArrayType>(getConstantArrayType(NewEltTy, CAT->getSize(),
3319                                                CAT->getSizeModifier(),
3320                                           CAT->getIndexTypeCVRQualifiers()));
3321  if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(ATy))
3322    return cast<ArrayType>(getIncompleteArrayType(NewEltTy,
3323                                                  IAT->getSizeModifier(),
3324                                           IAT->getIndexTypeCVRQualifiers()));
3325
3326  if (const DependentSizedArrayType *DSAT
3327        = dyn_cast<DependentSizedArrayType>(ATy))
3328    return cast<ArrayType>(
3329                     getDependentSizedArrayType(NewEltTy,
3330                                                DSAT->getSizeExpr(),
3331                                                DSAT->getSizeModifier(),
3332                                              DSAT->getIndexTypeCVRQualifiers(),
3333                                                DSAT->getBracketsRange()));
3334
3335  const VariableArrayType *VAT = cast<VariableArrayType>(ATy);
3336  return cast<ArrayType>(getVariableArrayType(NewEltTy,
3337                                              VAT->getSizeExpr(),
3338                                              VAT->getSizeModifier(),
3339                                              VAT->getIndexTypeCVRQualifiers(),
3340                                              VAT->getBracketsRange()));
3341}
3342
3343QualType ASTContext::getAdjustedParameterType(QualType T) {
3344  // C99 6.7.5.3p7:
3345  //   A declaration of a parameter as "array of type" shall be
3346  //   adjusted to "qualified pointer to type", where the type
3347  //   qualifiers (if any) are those specified within the [ and ] of
3348  //   the array type derivation.
3349  if (T->isArrayType())
3350    return getArrayDecayedType(T);
3351
3352  // C99 6.7.5.3p8:
3353  //   A declaration of a parameter as "function returning type"
3354  //   shall be adjusted to "pointer to function returning type", as
3355  //   in 6.3.2.1.
3356  if (T->isFunctionType())
3357    return getPointerType(T);
3358
3359  return T;
3360}
3361
3362QualType ASTContext::getSignatureParameterType(QualType T) {
3363  T = getVariableArrayDecayedType(T);
3364  T = getAdjustedParameterType(T);
3365  return T.getUnqualifiedType();
3366}
3367
3368/// getArrayDecayedType - Return the properly qualified result of decaying the
3369/// specified array type to a pointer.  This operation is non-trivial when
3370/// handling typedefs etc.  The canonical type of "T" must be an array type,
3371/// this returns a pointer to a properly qualified element of the array.
3372///
3373/// See C99 6.7.5.3p7 and C99 6.3.2.1p3.
3374QualType ASTContext::getArrayDecayedType(QualType Ty) const {
3375  // Get the element type with 'getAsArrayType' so that we don't lose any
3376  // typedefs in the element type of the array.  This also handles propagation
3377  // of type qualifiers from the array type into the element type if present
3378  // (C99 6.7.3p8).
3379  const ArrayType *PrettyArrayType = getAsArrayType(Ty);
3380  assert(PrettyArrayType && "Not an array type!");
3381
3382  QualType PtrTy = getPointerType(PrettyArrayType->getElementType());
3383
3384  // int x[restrict 4] ->  int *restrict
3385  return getQualifiedType(PtrTy, PrettyArrayType->getIndexTypeQualifiers());
3386}
3387
3388QualType ASTContext::getBaseElementType(const ArrayType *array) const {
3389  return getBaseElementType(array->getElementType());
3390}
3391
3392QualType ASTContext::getBaseElementType(QualType type) const {
3393  Qualifiers qs;
3394  while (true) {
3395    SplitQualType split = type.getSplitDesugaredType();
3396    const ArrayType *array = split.first->getAsArrayTypeUnsafe();
3397    if (!array) break;
3398
3399    type = array->getElementType();
3400    qs.addConsistentQualifiers(split.second);
3401  }
3402
3403  return getQualifiedType(type, qs);
3404}
3405
3406/// getConstantArrayElementCount - Returns number of constant array elements.
3407uint64_t
3408ASTContext::getConstantArrayElementCount(const ConstantArrayType *CA)  const {
3409  uint64_t ElementCount = 1;
3410  do {
3411    ElementCount *= CA->getSize().getZExtValue();
3412    CA = dyn_cast<ConstantArrayType>(CA->getElementType());
3413  } while (CA);
3414  return ElementCount;
3415}
3416
3417/// getFloatingRank - Return a relative rank for floating point types.
3418/// This routine will assert if passed a built-in type that isn't a float.
3419static FloatingRank getFloatingRank(QualType T) {
3420  if (const ComplexType *CT = T->getAs<ComplexType>())
3421    return getFloatingRank(CT->getElementType());
3422
3423  assert(T->getAs<BuiltinType>() && "getFloatingRank(): not a floating type");
3424  switch (T->getAs<BuiltinType>()->getKind()) {
3425  default: assert(0 && "getFloatingRank(): not a floating type");
3426  case BuiltinType::Float:      return FloatRank;
3427  case BuiltinType::Double:     return DoubleRank;
3428  case BuiltinType::LongDouble: return LongDoubleRank;
3429  }
3430}
3431
3432/// getFloatingTypeOfSizeWithinDomain - Returns a real floating
3433/// point or a complex type (based on typeDomain/typeSize).
3434/// 'typeDomain' is a real floating point or complex type.
3435/// 'typeSize' is a real floating point or complex type.
3436QualType ASTContext::getFloatingTypeOfSizeWithinDomain(QualType Size,
3437                                                       QualType Domain) const {
3438  FloatingRank EltRank = getFloatingRank(Size);
3439  if (Domain->isComplexType()) {
3440    switch (EltRank) {
3441    default: assert(0 && "getFloatingRank(): illegal value for rank");
3442    case FloatRank:      return FloatComplexTy;
3443    case DoubleRank:     return DoubleComplexTy;
3444    case LongDoubleRank: return LongDoubleComplexTy;
3445    }
3446  }
3447
3448  assert(Domain->isRealFloatingType() && "Unknown domain!");
3449  switch (EltRank) {
3450  default: assert(0 && "getFloatingRank(): illegal value for rank");
3451  case FloatRank:      return FloatTy;
3452  case DoubleRank:     return DoubleTy;
3453  case LongDoubleRank: return LongDoubleTy;
3454  }
3455}
3456
3457/// getFloatingTypeOrder - Compare the rank of the two specified floating
3458/// point types, ignoring the domain of the type (i.e. 'double' ==
3459/// '_Complex double').  If LHS > RHS, return 1.  If LHS == RHS, return 0. If
3460/// LHS < RHS, return -1.
3461int ASTContext::getFloatingTypeOrder(QualType LHS, QualType RHS) const {
3462  FloatingRank LHSR = getFloatingRank(LHS);
3463  FloatingRank RHSR = getFloatingRank(RHS);
3464
3465  if (LHSR == RHSR)
3466    return 0;
3467  if (LHSR > RHSR)
3468    return 1;
3469  return -1;
3470}
3471
3472/// getIntegerRank - Return an integer conversion rank (C99 6.3.1.1p1). This
3473/// routine will assert if passed a built-in type that isn't an integer or enum,
3474/// or if it is not canonicalized.
3475unsigned ASTContext::getIntegerRank(const Type *T) const {
3476  assert(T->isCanonicalUnqualified() && "T should be canonicalized");
3477  if (const EnumType* ET = dyn_cast<EnumType>(T))
3478    T = ET->getDecl()->getPromotionType().getTypePtr();
3479
3480  if (T->isSpecificBuiltinType(BuiltinType::WChar_S) ||
3481      T->isSpecificBuiltinType(BuiltinType::WChar_U))
3482    T = getFromTargetType(Target.getWCharType()).getTypePtr();
3483
3484  if (T->isSpecificBuiltinType(BuiltinType::Char16))
3485    T = getFromTargetType(Target.getChar16Type()).getTypePtr();
3486
3487  if (T->isSpecificBuiltinType(BuiltinType::Char32))
3488    T = getFromTargetType(Target.getChar32Type()).getTypePtr();
3489
3490  switch (cast<BuiltinType>(T)->getKind()) {
3491  default: assert(0 && "getIntegerRank(): not a built-in integer");
3492  case BuiltinType::Bool:
3493    return 1 + (getIntWidth(BoolTy) << 3);
3494  case BuiltinType::Char_S:
3495  case BuiltinType::Char_U:
3496  case BuiltinType::SChar:
3497  case BuiltinType::UChar:
3498    return 2 + (getIntWidth(CharTy) << 3);
3499  case BuiltinType::Short:
3500  case BuiltinType::UShort:
3501    return 3 + (getIntWidth(ShortTy) << 3);
3502  case BuiltinType::Int:
3503  case BuiltinType::UInt:
3504    return 4 + (getIntWidth(IntTy) << 3);
3505  case BuiltinType::Long:
3506  case BuiltinType::ULong:
3507    return 5 + (getIntWidth(LongTy) << 3);
3508  case BuiltinType::LongLong:
3509  case BuiltinType::ULongLong:
3510    return 6 + (getIntWidth(LongLongTy) << 3);
3511  case BuiltinType::Int128:
3512  case BuiltinType::UInt128:
3513    return 7 + (getIntWidth(Int128Ty) << 3);
3514  }
3515}
3516
3517/// \brief Whether this is a promotable bitfield reference according
3518/// to C99 6.3.1.1p2, bullet 2 (and GCC extensions).
3519///
3520/// \returns the type this bit-field will promote to, or NULL if no
3521/// promotion occurs.
3522QualType ASTContext::isPromotableBitField(Expr *E) const {
3523  if (E->isTypeDependent() || E->isValueDependent())
3524    return QualType();
3525
3526  FieldDecl *Field = E->getBitField();
3527  if (!Field)
3528    return QualType();
3529
3530  QualType FT = Field->getType();
3531
3532  llvm::APSInt BitWidthAP = Field->getBitWidth()->EvaluateAsInt(*this);
3533  uint64_t BitWidth = BitWidthAP.getZExtValue();
3534  uint64_t IntSize = getTypeSize(IntTy);
3535  // GCC extension compatibility: if the bit-field size is less than or equal
3536  // to the size of int, it gets promoted no matter what its type is.
3537  // For instance, unsigned long bf : 4 gets promoted to signed int.
3538  if (BitWidth < IntSize)
3539    return IntTy;
3540
3541  if (BitWidth == IntSize)
3542    return FT->isSignedIntegerType() ? IntTy : UnsignedIntTy;
3543
3544  // Types bigger than int are not subject to promotions, and therefore act
3545  // like the base type.
3546  // FIXME: This doesn't quite match what gcc does, but what gcc does here
3547  // is ridiculous.
3548  return QualType();
3549}
3550
3551/// getPromotedIntegerType - Returns the type that Promotable will
3552/// promote to: C99 6.3.1.1p2, assuming that Promotable is a promotable
3553/// integer type.
3554QualType ASTContext::getPromotedIntegerType(QualType Promotable) const {
3555  assert(!Promotable.isNull());
3556  assert(Promotable->isPromotableIntegerType());
3557  if (const EnumType *ET = Promotable->getAs<EnumType>())
3558    return ET->getDecl()->getPromotionType();
3559  if (Promotable->isSignedIntegerType())
3560    return IntTy;
3561  uint64_t PromotableSize = getTypeSize(Promotable);
3562  uint64_t IntSize = getTypeSize(IntTy);
3563  assert(Promotable->isUnsignedIntegerType() && PromotableSize <= IntSize);
3564  return (PromotableSize != IntSize) ? IntTy : UnsignedIntTy;
3565}
3566
3567/// \brief Recurses in pointer/array types until it finds an objc retainable
3568/// type and returns its ownership.
3569Qualifiers::ObjCLifetime ASTContext::getInnerObjCOwnership(QualType T) const {
3570  while (!T.isNull()) {
3571    if (T.getObjCLifetime() != Qualifiers::OCL_None)
3572      return T.getObjCLifetime();
3573    if (T->isArrayType())
3574      T = getBaseElementType(T);
3575    else if (const PointerType *PT = T->getAs<PointerType>())
3576      T = PT->getPointeeType();
3577    else if (const ReferenceType *RT = T->getAs<ReferenceType>())
3578      T = RT->getPointeeType();
3579    else
3580      break;
3581  }
3582
3583  return Qualifiers::OCL_None;
3584}
3585
3586/// getIntegerTypeOrder - Returns the highest ranked integer type:
3587/// C99 6.3.1.8p1.  If LHS > RHS, return 1.  If LHS == RHS, return 0. If
3588/// LHS < RHS, return -1.
3589int ASTContext::getIntegerTypeOrder(QualType LHS, QualType RHS) const {
3590  const Type *LHSC = getCanonicalType(LHS).getTypePtr();
3591  const Type *RHSC = getCanonicalType(RHS).getTypePtr();
3592  if (LHSC == RHSC) return 0;
3593
3594  bool LHSUnsigned = LHSC->isUnsignedIntegerType();
3595  bool RHSUnsigned = RHSC->isUnsignedIntegerType();
3596
3597  unsigned LHSRank = getIntegerRank(LHSC);
3598  unsigned RHSRank = getIntegerRank(RHSC);
3599
3600  if (LHSUnsigned == RHSUnsigned) {  // Both signed or both unsigned.
3601    if (LHSRank == RHSRank) return 0;
3602    return LHSRank > RHSRank ? 1 : -1;
3603  }
3604
3605  // Otherwise, the LHS is signed and the RHS is unsigned or visa versa.
3606  if (LHSUnsigned) {
3607    // If the unsigned [LHS] type is larger, return it.
3608    if (LHSRank >= RHSRank)
3609      return 1;
3610
3611    // If the signed type can represent all values of the unsigned type, it
3612    // wins.  Because we are dealing with 2's complement and types that are
3613    // powers of two larger than each other, this is always safe.
3614    return -1;
3615  }
3616
3617  // If the unsigned [RHS] type is larger, return it.
3618  if (RHSRank >= LHSRank)
3619    return -1;
3620
3621  // If the signed type can represent all values of the unsigned type, it
3622  // wins.  Because we are dealing with 2's complement and types that are
3623  // powers of two larger than each other, this is always safe.
3624  return 1;
3625}
3626
3627static RecordDecl *
3628CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK,
3629                 DeclContext *DC, IdentifierInfo *Id) {
3630  SourceLocation Loc;
3631  if (Ctx.getLangOptions().CPlusPlus)
3632    return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
3633  else
3634    return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
3635}
3636
3637// getCFConstantStringType - Return the type used for constant CFStrings.
3638QualType ASTContext::getCFConstantStringType() const {
3639  if (!CFConstantStringTypeDecl) {
3640    CFConstantStringTypeDecl =
3641      CreateRecordDecl(*this, TTK_Struct, TUDecl,
3642                       &Idents.get("NSConstantString"));
3643    CFConstantStringTypeDecl->startDefinition();
3644
3645    QualType FieldTypes[4];
3646
3647    // const int *isa;
3648    FieldTypes[0] = getPointerType(IntTy.withConst());
3649    // int flags;
3650    FieldTypes[1] = IntTy;
3651    // const char *str;
3652    FieldTypes[2] = getPointerType(CharTy.withConst());
3653    // long length;
3654    FieldTypes[3] = LongTy;
3655
3656    // Create fields
3657    for (unsigned i = 0; i < 4; ++i) {
3658      FieldDecl *Field = FieldDecl::Create(*this, CFConstantStringTypeDecl,
3659                                           SourceLocation(),
3660                                           SourceLocation(), 0,
3661                                           FieldTypes[i], /*TInfo=*/0,
3662                                           /*BitWidth=*/0,
3663                                           /*Mutable=*/false,
3664                                           /*HasInit=*/false);
3665      Field->setAccess(AS_public);
3666      CFConstantStringTypeDecl->addDecl(Field);
3667    }
3668
3669    CFConstantStringTypeDecl->completeDefinition();
3670  }
3671
3672  return getTagDeclType(CFConstantStringTypeDecl);
3673}
3674
3675void ASTContext::setCFConstantStringType(QualType T) {
3676  const RecordType *Rec = T->getAs<RecordType>();
3677  assert(Rec && "Invalid CFConstantStringType");
3678  CFConstantStringTypeDecl = Rec->getDecl();
3679}
3680
3681QualType ASTContext::getBlockDescriptorType() const {
3682  if (BlockDescriptorType)
3683    return getTagDeclType(BlockDescriptorType);
3684
3685  RecordDecl *T;
3686  // FIXME: Needs the FlagAppleBlock bit.
3687  T = CreateRecordDecl(*this, TTK_Struct, TUDecl,
3688                       &Idents.get("__block_descriptor"));
3689  T->startDefinition();
3690
3691  QualType FieldTypes[] = {
3692    UnsignedLongTy,
3693    UnsignedLongTy,
3694  };
3695
3696  const char *FieldNames[] = {
3697    "reserved",
3698    "Size"
3699  };
3700
3701  for (size_t i = 0; i < 2; ++i) {
3702    FieldDecl *Field = FieldDecl::Create(*this, T, SourceLocation(),
3703                                         SourceLocation(),
3704                                         &Idents.get(FieldNames[i]),
3705                                         FieldTypes[i], /*TInfo=*/0,
3706                                         /*BitWidth=*/0,
3707                                         /*Mutable=*/false,
3708                                         /*HasInit=*/false);
3709    Field->setAccess(AS_public);
3710    T->addDecl(Field);
3711  }
3712
3713  T->completeDefinition();
3714
3715  BlockDescriptorType = T;
3716
3717  return getTagDeclType(BlockDescriptorType);
3718}
3719
3720QualType ASTContext::getBlockDescriptorExtendedType() const {
3721  if (BlockDescriptorExtendedType)
3722    return getTagDeclType(BlockDescriptorExtendedType);
3723
3724  RecordDecl *T;
3725  // FIXME: Needs the FlagAppleBlock bit.
3726  T = CreateRecordDecl(*this, TTK_Struct, TUDecl,
3727                       &Idents.get("__block_descriptor_withcopydispose"));
3728  T->startDefinition();
3729
3730  QualType FieldTypes[] = {
3731    UnsignedLongTy,
3732    UnsignedLongTy,
3733    getPointerType(VoidPtrTy),
3734    getPointerType(VoidPtrTy)
3735  };
3736
3737  const char *FieldNames[] = {
3738    "reserved",
3739    "Size",
3740    "CopyFuncPtr",
3741    "DestroyFuncPtr"
3742  };
3743
3744  for (size_t i = 0; i < 4; ++i) {
3745    FieldDecl *Field = FieldDecl::Create(*this, T, SourceLocation(),
3746                                         SourceLocation(),
3747                                         &Idents.get(FieldNames[i]),
3748                                         FieldTypes[i], /*TInfo=*/0,
3749                                         /*BitWidth=*/0,
3750                                         /*Mutable=*/false,
3751                                         /*HasInit=*/false);
3752    Field->setAccess(AS_public);
3753    T->addDecl(Field);
3754  }
3755
3756  T->completeDefinition();
3757
3758  BlockDescriptorExtendedType = T;
3759
3760  return getTagDeclType(BlockDescriptorExtendedType);
3761}
3762
3763bool ASTContext::BlockRequiresCopying(QualType Ty) const {
3764  if (Ty->isObjCRetainableType())
3765    return true;
3766  if (getLangOptions().CPlusPlus) {
3767    if (const RecordType *RT = Ty->getAs<RecordType>()) {
3768      CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
3769      return RD->hasConstCopyConstructor();
3770
3771    }
3772  }
3773  return false;
3774}
3775
3776QualType
3777ASTContext::BuildByRefType(StringRef DeclName, QualType Ty) const {
3778  //  type = struct __Block_byref_1_X {
3779  //    void *__isa;
3780  //    struct __Block_byref_1_X *__forwarding;
3781  //    unsigned int __flags;
3782  //    unsigned int __size;
3783  //    void *__copy_helper;            // as needed
3784  //    void *__destroy_help            // as needed
3785  //    int X;
3786  //  } *
3787
3788  bool HasCopyAndDispose = BlockRequiresCopying(Ty);
3789
3790  // FIXME: Move up
3791  llvm::SmallString<36> Name;
3792  llvm::raw_svector_ostream(Name) << "__Block_byref_" <<
3793                                  ++UniqueBlockByRefTypeID << '_' << DeclName;
3794  RecordDecl *T;
3795  T = CreateRecordDecl(*this, TTK_Struct, TUDecl, &Idents.get(Name.str()));
3796  T->startDefinition();
3797  QualType Int32Ty = IntTy;
3798  assert(getIntWidth(IntTy) == 32 && "non-32bit int not supported");
3799  QualType FieldTypes[] = {
3800    getPointerType(VoidPtrTy),
3801    getPointerType(getTagDeclType(T)),
3802    Int32Ty,
3803    Int32Ty,
3804    getPointerType(VoidPtrTy),
3805    getPointerType(VoidPtrTy),
3806    Ty
3807  };
3808
3809  StringRef FieldNames[] = {
3810    "__isa",
3811    "__forwarding",
3812    "__flags",
3813    "__size",
3814    "__copy_helper",
3815    "__destroy_helper",
3816    DeclName,
3817  };
3818
3819  for (size_t i = 0; i < 7; ++i) {
3820    if (!HasCopyAndDispose && i >=4 && i <= 5)
3821      continue;
3822    FieldDecl *Field = FieldDecl::Create(*this, T, SourceLocation(),
3823                                         SourceLocation(),
3824                                         &Idents.get(FieldNames[i]),
3825                                         FieldTypes[i], /*TInfo=*/0,
3826                                         /*BitWidth=*/0, /*Mutable=*/false,
3827                                         /*HasInit=*/false);
3828    Field->setAccess(AS_public);
3829    T->addDecl(Field);
3830  }
3831
3832  T->completeDefinition();
3833
3834  return getPointerType(getTagDeclType(T));
3835}
3836
3837// This returns true if a type has been typedefed to BOOL:
3838// typedef <type> BOOL;
3839static bool isTypeTypedefedAsBOOL(QualType T) {
3840  if (const TypedefType *TT = dyn_cast<TypedefType>(T))
3841    if (IdentifierInfo *II = TT->getDecl()->getIdentifier())
3842      return II->isStr("BOOL");
3843
3844  return false;
3845}
3846
3847/// getObjCEncodingTypeSize returns size of type for objective-c encoding
3848/// purpose.
3849CharUnits ASTContext::getObjCEncodingTypeSize(QualType type) const {
3850  if (!type->isIncompleteArrayType() && type->isIncompleteType())
3851    return CharUnits::Zero();
3852
3853  CharUnits sz = getTypeSizeInChars(type);
3854
3855  // Make all integer and enum types at least as large as an int
3856  if (sz.isPositive() && type->isIntegralOrEnumerationType())
3857    sz = std::max(sz, getTypeSizeInChars(IntTy));
3858  // Treat arrays as pointers, since that's how they're passed in.
3859  else if (type->isArrayType())
3860    sz = getTypeSizeInChars(VoidPtrTy);
3861  return sz;
3862}
3863
3864static inline
3865std::string charUnitsToString(const CharUnits &CU) {
3866  return llvm::itostr(CU.getQuantity());
3867}
3868
3869/// getObjCEncodingForBlock - Return the encoded type for this block
3870/// declaration.
3871std::string ASTContext::getObjCEncodingForBlock(const BlockExpr *Expr) const {
3872  std::string S;
3873
3874  const BlockDecl *Decl = Expr->getBlockDecl();
3875  QualType BlockTy =
3876      Expr->getType()->getAs<BlockPointerType>()->getPointeeType();
3877  // Encode result type.
3878  getObjCEncodingForType(BlockTy->getAs<FunctionType>()->getResultType(), S);
3879  // Compute size of all parameters.
3880  // Start with computing size of a pointer in number of bytes.
3881  // FIXME: There might(should) be a better way of doing this computation!
3882  SourceLocation Loc;
3883  CharUnits PtrSize = getTypeSizeInChars(VoidPtrTy);
3884  CharUnits ParmOffset = PtrSize;
3885  for (BlockDecl::param_const_iterator PI = Decl->param_begin(),
3886       E = Decl->param_end(); PI != E; ++PI) {
3887    QualType PType = (*PI)->getType();
3888    CharUnits sz = getObjCEncodingTypeSize(PType);
3889    assert (sz.isPositive() && "BlockExpr - Incomplete param type");
3890    ParmOffset += sz;
3891  }
3892  // Size of the argument frame
3893  S += charUnitsToString(ParmOffset);
3894  // Block pointer and offset.
3895  S += "@?0";
3896
3897  // Argument types.
3898  ParmOffset = PtrSize;
3899  for (BlockDecl::param_const_iterator PI = Decl->param_begin(), E =
3900       Decl->param_end(); PI != E; ++PI) {
3901    ParmVarDecl *PVDecl = *PI;
3902    QualType PType = PVDecl->getOriginalType();
3903    if (const ArrayType *AT =
3904          dyn_cast<ArrayType>(PType->getCanonicalTypeInternal())) {
3905      // Use array's original type only if it has known number of
3906      // elements.
3907      if (!isa<ConstantArrayType>(AT))
3908        PType = PVDecl->getType();
3909    } else if (PType->isFunctionType())
3910      PType = PVDecl->getType();
3911    getObjCEncodingForType(PType, S);
3912    S += charUnitsToString(ParmOffset);
3913    ParmOffset += getObjCEncodingTypeSize(PType);
3914  }
3915
3916  return S;
3917}
3918
3919bool ASTContext::getObjCEncodingForFunctionDecl(const FunctionDecl *Decl,
3920                                                std::string& S) {
3921  // Encode result type.
3922  getObjCEncodingForType(Decl->getResultType(), S);
3923  CharUnits ParmOffset;
3924  // Compute size of all parameters.
3925  for (FunctionDecl::param_const_iterator PI = Decl->param_begin(),
3926       E = Decl->param_end(); PI != E; ++PI) {
3927    QualType PType = (*PI)->getType();
3928    CharUnits sz = getObjCEncodingTypeSize(PType);
3929    if (sz.isZero())
3930      return true;
3931
3932    assert (sz.isPositive() &&
3933        "getObjCEncodingForFunctionDecl - Incomplete param type");
3934    ParmOffset += sz;
3935  }
3936  S += charUnitsToString(ParmOffset);
3937  ParmOffset = CharUnits::Zero();
3938
3939  // Argument types.
3940  for (FunctionDecl::param_const_iterator PI = Decl->param_begin(),
3941       E = Decl->param_end(); PI != E; ++PI) {
3942    ParmVarDecl *PVDecl = *PI;
3943    QualType PType = PVDecl->getOriginalType();
3944    if (const ArrayType *AT =
3945          dyn_cast<ArrayType>(PType->getCanonicalTypeInternal())) {
3946      // Use array's original type only if it has known number of
3947      // elements.
3948      if (!isa<ConstantArrayType>(AT))
3949        PType = PVDecl->getType();
3950    } else if (PType->isFunctionType())
3951      PType = PVDecl->getType();
3952    getObjCEncodingForType(PType, S);
3953    S += charUnitsToString(ParmOffset);
3954    ParmOffset += getObjCEncodingTypeSize(PType);
3955  }
3956
3957  return false;
3958}
3959
3960/// getObjCEncodingForMethodDecl - Return the encoded type for this method
3961/// declaration.
3962bool ASTContext::getObjCEncodingForMethodDecl(const ObjCMethodDecl *Decl,
3963                                              std::string& S) const {
3964  // FIXME: This is not very efficient.
3965  // Encode type qualifer, 'in', 'inout', etc. for the return type.
3966  getObjCEncodingForTypeQualifier(Decl->getObjCDeclQualifier(), S);
3967  // Encode result type.
3968  getObjCEncodingForType(Decl->getResultType(), S);
3969  // Compute size of all parameters.
3970  // Start with computing size of a pointer in number of bytes.
3971  // FIXME: There might(should) be a better way of doing this computation!
3972  SourceLocation Loc;
3973  CharUnits PtrSize = getTypeSizeInChars(VoidPtrTy);
3974  // The first two arguments (self and _cmd) are pointers; account for
3975  // their size.
3976  CharUnits ParmOffset = 2 * PtrSize;
3977  for (ObjCMethodDecl::param_iterator PI = Decl->param_begin(),
3978       E = Decl->sel_param_end(); PI != E; ++PI) {
3979    QualType PType = (*PI)->getType();
3980    CharUnits sz = getObjCEncodingTypeSize(PType);
3981    if (sz.isZero())
3982      return true;
3983
3984    assert (sz.isPositive() &&
3985        "getObjCEncodingForMethodDecl - Incomplete param type");
3986    ParmOffset += sz;
3987  }
3988  S += charUnitsToString(ParmOffset);
3989  S += "@0:";
3990  S += charUnitsToString(PtrSize);
3991
3992  // Argument types.
3993  ParmOffset = 2 * PtrSize;
3994  for (ObjCMethodDecl::param_iterator PI = Decl->param_begin(),
3995       E = Decl->sel_param_end(); PI != E; ++PI) {
3996    ParmVarDecl *PVDecl = *PI;
3997    QualType PType = PVDecl->getOriginalType();
3998    if (const ArrayType *AT =
3999          dyn_cast<ArrayType>(PType->getCanonicalTypeInternal())) {
4000      // Use array's original type only if it has known number of
4001      // elements.
4002      if (!isa<ConstantArrayType>(AT))
4003        PType = PVDecl->getType();
4004    } else if (PType->isFunctionType())
4005      PType = PVDecl->getType();
4006    // Process argument qualifiers for user supplied arguments; such as,
4007    // 'in', 'inout', etc.
4008    getObjCEncodingForTypeQualifier(PVDecl->getObjCDeclQualifier(), S);
4009    getObjCEncodingForType(PType, S);
4010    S += charUnitsToString(ParmOffset);
4011    ParmOffset += getObjCEncodingTypeSize(PType);
4012  }
4013
4014  return false;
4015}
4016
4017/// getObjCEncodingForPropertyDecl - Return the encoded type for this
4018/// property declaration. If non-NULL, Container must be either an
4019/// ObjCCategoryImplDecl or ObjCImplementationDecl; it should only be
4020/// NULL when getting encodings for protocol properties.
4021/// Property attributes are stored as a comma-delimited C string. The simple
4022/// attributes readonly and bycopy are encoded as single characters. The
4023/// parametrized attributes, getter=name, setter=name, and ivar=name, are
4024/// encoded as single characters, followed by an identifier. Property types
4025/// are also encoded as a parametrized attribute. The characters used to encode
4026/// these attributes are defined by the following enumeration:
4027/// @code
4028/// enum PropertyAttributes {
4029/// kPropertyReadOnly = 'R',   // property is read-only.
4030/// kPropertyBycopy = 'C',     // property is a copy of the value last assigned
4031/// kPropertyByref = '&',  // property is a reference to the value last assigned
4032/// kPropertyDynamic = 'D',    // property is dynamic
4033/// kPropertyGetter = 'G',     // followed by getter selector name
4034/// kPropertySetter = 'S',     // followed by setter selector name
4035/// kPropertyInstanceVariable = 'V'  // followed by instance variable  name
4036/// kPropertyType = 't'              // followed by old-style type encoding.
4037/// kPropertyWeak = 'W'              // 'weak' property
4038/// kPropertyStrong = 'P'            // property GC'able
4039/// kPropertyNonAtomic = 'N'         // property non-atomic
4040/// };
4041/// @endcode
4042void ASTContext::getObjCEncodingForPropertyDecl(const ObjCPropertyDecl *PD,
4043                                                const Decl *Container,
4044                                                std::string& S) const {
4045  // Collect information from the property implementation decl(s).
4046  bool Dynamic = false;
4047  ObjCPropertyImplDecl *SynthesizePID = 0;
4048
4049  // FIXME: Duplicated code due to poor abstraction.
4050  if (Container) {
4051    if (const ObjCCategoryImplDecl *CID =
4052        dyn_cast<ObjCCategoryImplDecl>(Container)) {
4053      for (ObjCCategoryImplDecl::propimpl_iterator
4054             i = CID->propimpl_begin(), e = CID->propimpl_end();
4055           i != e; ++i) {
4056        ObjCPropertyImplDecl *PID = *i;
4057        if (PID->getPropertyDecl() == PD) {
4058          if (PID->getPropertyImplementation()==ObjCPropertyImplDecl::Dynamic) {
4059            Dynamic = true;
4060          } else {
4061            SynthesizePID = PID;
4062          }
4063        }
4064      }
4065    } else {
4066      const ObjCImplementationDecl *OID=cast<ObjCImplementationDecl>(Container);
4067      for (ObjCCategoryImplDecl::propimpl_iterator
4068             i = OID->propimpl_begin(), e = OID->propimpl_end();
4069           i != e; ++i) {
4070        ObjCPropertyImplDecl *PID = *i;
4071        if (PID->getPropertyDecl() == PD) {
4072          if (PID->getPropertyImplementation()==ObjCPropertyImplDecl::Dynamic) {
4073            Dynamic = true;
4074          } else {
4075            SynthesizePID = PID;
4076          }
4077        }
4078      }
4079    }
4080  }
4081
4082  // FIXME: This is not very efficient.
4083  S = "T";
4084
4085  // Encode result type.
4086  // GCC has some special rules regarding encoding of properties which
4087  // closely resembles encoding of ivars.
4088  getObjCEncodingForTypeImpl(PD->getType(), S, true, true, 0,
4089                             true /* outermost type */,
4090                             true /* encoding for property */);
4091
4092  if (PD->isReadOnly()) {
4093    S += ",R";
4094  } else {
4095    switch (PD->getSetterKind()) {
4096    case ObjCPropertyDecl::Assign: break;
4097    case ObjCPropertyDecl::Copy:   S += ",C"; break;
4098    case ObjCPropertyDecl::Retain: S += ",&"; break;
4099    case ObjCPropertyDecl::Weak:   S += ",W"; break;
4100    }
4101  }
4102
4103  // It really isn't clear at all what this means, since properties
4104  // are "dynamic by default".
4105  if (Dynamic)
4106    S += ",D";
4107
4108  if (PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
4109    S += ",N";
4110
4111  if (PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_getter) {
4112    S += ",G";
4113    S += PD->getGetterName().getAsString();
4114  }
4115
4116  if (PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_setter) {
4117    S += ",S";
4118    S += PD->getSetterName().getAsString();
4119  }
4120
4121  if (SynthesizePID) {
4122    const ObjCIvarDecl *OID = SynthesizePID->getPropertyIvarDecl();
4123    S += ",V";
4124    S += OID->getNameAsString();
4125  }
4126
4127  // FIXME: OBJCGC: weak & strong
4128}
4129
4130/// getLegacyIntegralTypeEncoding -
4131/// Another legacy compatibility encoding: 32-bit longs are encoded as
4132/// 'l' or 'L' , but not always.  For typedefs, we need to use
4133/// 'i' or 'I' instead if encoding a struct field, or a pointer!
4134///
4135void ASTContext::getLegacyIntegralTypeEncoding (QualType &PointeeTy) const {
4136  if (isa<TypedefType>(PointeeTy.getTypePtr())) {
4137    if (const BuiltinType *BT = PointeeTy->getAs<BuiltinType>()) {
4138      if (BT->getKind() == BuiltinType::ULong && getIntWidth(PointeeTy) == 32)
4139        PointeeTy = UnsignedIntTy;
4140      else
4141        if (BT->getKind() == BuiltinType::Long && getIntWidth(PointeeTy) == 32)
4142          PointeeTy = IntTy;
4143    }
4144  }
4145}
4146
4147void ASTContext::getObjCEncodingForType(QualType T, std::string& S,
4148                                        const FieldDecl *Field) const {
4149  // We follow the behavior of gcc, expanding structures which are
4150  // directly pointed to, and expanding embedded structures. Note that
4151  // these rules are sufficient to prevent recursive encoding of the
4152  // same type.
4153  getObjCEncodingForTypeImpl(T, S, true, true, Field,
4154                             true /* outermost type */);
4155}
4156
4157static char ObjCEncodingForPrimitiveKind(const ASTContext *C, QualType T) {
4158    switch (T->getAs<BuiltinType>()->getKind()) {
4159    default: assert(0 && "Unhandled builtin type kind");
4160    case BuiltinType::Void:       return 'v';
4161    case BuiltinType::Bool:       return 'B';
4162    case BuiltinType::Char_U:
4163    case BuiltinType::UChar:      return 'C';
4164    case BuiltinType::UShort:     return 'S';
4165    case BuiltinType::UInt:       return 'I';
4166    case BuiltinType::ULong:
4167        return C->getIntWidth(T) == 32 ? 'L' : 'Q';
4168    case BuiltinType::UInt128:    return 'T';
4169    case BuiltinType::ULongLong:  return 'Q';
4170    case BuiltinType::Char_S:
4171    case BuiltinType::SChar:      return 'c';
4172    case BuiltinType::Short:      return 's';
4173    case BuiltinType::WChar_S:
4174    case BuiltinType::WChar_U:
4175    case BuiltinType::Int:        return 'i';
4176    case BuiltinType::Long:
4177      return C->getIntWidth(T) == 32 ? 'l' : 'q';
4178    case BuiltinType::LongLong:   return 'q';
4179    case BuiltinType::Int128:     return 't';
4180    case BuiltinType::Float:      return 'f';
4181    case BuiltinType::Double:     return 'd';
4182    case BuiltinType::LongDouble: return 'D';
4183    }
4184}
4185
4186static void EncodeBitField(const ASTContext *Ctx, std::string& S,
4187                           QualType T, const FieldDecl *FD) {
4188  const Expr *E = FD->getBitWidth();
4189  assert(E && "bitfield width not there - getObjCEncodingForTypeImpl");
4190  S += 'b';
4191  // The NeXT runtime encodes bit fields as b followed by the number of bits.
4192  // The GNU runtime requires more information; bitfields are encoded as b,
4193  // then the offset (in bits) of the first element, then the type of the
4194  // bitfield, then the size in bits.  For example, in this structure:
4195  //
4196  // struct
4197  // {
4198  //    int integer;
4199  //    int flags:2;
4200  // };
4201  // On a 32-bit system, the encoding for flags would be b2 for the NeXT
4202  // runtime, but b32i2 for the GNU runtime.  The reason for this extra
4203  // information is not especially sensible, but we're stuck with it for
4204  // compatibility with GCC, although providing it breaks anything that
4205  // actually uses runtime introspection and wants to work on both runtimes...
4206  if (!Ctx->getLangOptions().NeXTRuntime) {
4207    const RecordDecl *RD = FD->getParent();
4208    const ASTRecordLayout &RL = Ctx->getASTRecordLayout(RD);
4209    S += llvm::utostr(RL.getFieldOffset(FD->getFieldIndex()));
4210    if (T->isEnumeralType())
4211      S += 'i';
4212    else
4213      S += ObjCEncodingForPrimitiveKind(Ctx, T);
4214  }
4215  unsigned N = E->EvaluateAsInt(*Ctx).getZExtValue();
4216  S += llvm::utostr(N);
4217}
4218
4219// FIXME: Use SmallString for accumulating string.
4220void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string& S,
4221                                            bool ExpandPointedToStructures,
4222                                            bool ExpandStructures,
4223                                            const FieldDecl *FD,
4224                                            bool OutermostType,
4225                                            bool EncodingProperty,
4226                                            bool StructField) const {
4227  if (T->getAs<BuiltinType>()) {
4228    if (FD && FD->isBitField())
4229      return EncodeBitField(this, S, T, FD);
4230    S += ObjCEncodingForPrimitiveKind(this, T);
4231    return;
4232  }
4233
4234  if (const ComplexType *CT = T->getAs<ComplexType>()) {
4235    S += 'j';
4236    getObjCEncodingForTypeImpl(CT->getElementType(), S, false, false, 0, false,
4237                               false);
4238    return;
4239  }
4240
4241  // encoding for pointer or r3eference types.
4242  QualType PointeeTy;
4243  if (const PointerType *PT = T->getAs<PointerType>()) {
4244    if (PT->isObjCSelType()) {
4245      S += ':';
4246      return;
4247    }
4248    PointeeTy = PT->getPointeeType();
4249  }
4250  else if (const ReferenceType *RT = T->getAs<ReferenceType>())
4251    PointeeTy = RT->getPointeeType();
4252  if (!PointeeTy.isNull()) {
4253    bool isReadOnly = false;
4254    // For historical/compatibility reasons, the read-only qualifier of the
4255    // pointee gets emitted _before_ the '^'.  The read-only qualifier of
4256    // the pointer itself gets ignored, _unless_ we are looking at a typedef!
4257    // Also, do not emit the 'r' for anything but the outermost type!
4258    if (isa<TypedefType>(T.getTypePtr())) {
4259      if (OutermostType && T.isConstQualified()) {
4260        isReadOnly = true;
4261        S += 'r';
4262      }
4263    } else if (OutermostType) {
4264      QualType P = PointeeTy;
4265      while (P->getAs<PointerType>())
4266        P = P->getAs<PointerType>()->getPointeeType();
4267      if (P.isConstQualified()) {
4268        isReadOnly = true;
4269        S += 'r';
4270      }
4271    }
4272    if (isReadOnly) {
4273      // Another legacy compatibility encoding. Some ObjC qualifier and type
4274      // combinations need to be rearranged.
4275      // Rewrite "in const" from "nr" to "rn"
4276      if (StringRef(S).endswith("nr"))
4277        S.replace(S.end()-2, S.end(), "rn");
4278    }
4279
4280    if (PointeeTy->isCharType()) {
4281      // char pointer types should be encoded as '*' unless it is a
4282      // type that has been typedef'd to 'BOOL'.
4283      if (!isTypeTypedefedAsBOOL(PointeeTy)) {
4284        S += '*';
4285        return;
4286      }
4287    } else if (const RecordType *RTy = PointeeTy->getAs<RecordType>()) {
4288      // GCC binary compat: Need to convert "struct objc_class *" to "#".
4289      if (RTy->getDecl()->getIdentifier() == &Idents.get("objc_class")) {
4290        S += '#';
4291        return;
4292      }
4293      // GCC binary compat: Need to convert "struct objc_object *" to "@".
4294      if (RTy->getDecl()->getIdentifier() == &Idents.get("objc_object")) {
4295        S += '@';
4296        return;
4297      }
4298      // fall through...
4299    }
4300    S += '^';
4301    getLegacyIntegralTypeEncoding(PointeeTy);
4302
4303    getObjCEncodingForTypeImpl(PointeeTy, S, false, ExpandPointedToStructures,
4304                               NULL);
4305    return;
4306  }
4307
4308  if (const ArrayType *AT =
4309      // Ignore type qualifiers etc.
4310        dyn_cast<ArrayType>(T->getCanonicalTypeInternal())) {
4311    if (isa<IncompleteArrayType>(AT) && !StructField) {
4312      // Incomplete arrays are encoded as a pointer to the array element.
4313      S += '^';
4314
4315      getObjCEncodingForTypeImpl(AT->getElementType(), S,
4316                                 false, ExpandStructures, FD);
4317    } else {
4318      S += '[';
4319
4320      if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT)) {
4321        if (getTypeSize(CAT->getElementType()) == 0)
4322          S += '0';
4323        else
4324          S += llvm::utostr(CAT->getSize().getZExtValue());
4325      } else {
4326        //Variable length arrays are encoded as a regular array with 0 elements.
4327        assert((isa<VariableArrayType>(AT) || isa<IncompleteArrayType>(AT)) &&
4328               "Unknown array type!");
4329        S += '0';
4330      }
4331
4332      getObjCEncodingForTypeImpl(AT->getElementType(), S,
4333                                 false, ExpandStructures, FD);
4334      S += ']';
4335    }
4336    return;
4337  }
4338
4339  if (T->getAs<FunctionType>()) {
4340    S += '?';
4341    return;
4342  }
4343
4344  if (const RecordType *RTy = T->getAs<RecordType>()) {
4345    RecordDecl *RDecl = RTy->getDecl();
4346    S += RDecl->isUnion() ? '(' : '{';
4347    // Anonymous structures print as '?'
4348    if (const IdentifierInfo *II = RDecl->getIdentifier()) {
4349      S += II->getName();
4350      if (ClassTemplateSpecializationDecl *Spec
4351          = dyn_cast<ClassTemplateSpecializationDecl>(RDecl)) {
4352        const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
4353        std::string TemplateArgsStr
4354          = TemplateSpecializationType::PrintTemplateArgumentList(
4355                                            TemplateArgs.data(),
4356                                            TemplateArgs.size(),
4357                                            (*this).PrintingPolicy);
4358
4359        S += TemplateArgsStr;
4360      }
4361    } else {
4362      S += '?';
4363    }
4364    if (ExpandStructures) {
4365      S += '=';
4366      if (!RDecl->isUnion()) {
4367        getObjCEncodingForStructureImpl(RDecl, S, FD);
4368      } else {
4369        for (RecordDecl::field_iterator Field = RDecl->field_begin(),
4370                                     FieldEnd = RDecl->field_end();
4371             Field != FieldEnd; ++Field) {
4372          if (FD) {
4373            S += '"';
4374            S += Field->getNameAsString();
4375            S += '"';
4376          }
4377
4378          // Special case bit-fields.
4379          if (Field->isBitField()) {
4380            getObjCEncodingForTypeImpl(Field->getType(), S, false, true,
4381                                       (*Field));
4382          } else {
4383            QualType qt = Field->getType();
4384            getLegacyIntegralTypeEncoding(qt);
4385            getObjCEncodingForTypeImpl(qt, S, false, true,
4386                                       FD, /*OutermostType*/false,
4387                                       /*EncodingProperty*/false,
4388                                       /*StructField*/true);
4389          }
4390        }
4391      }
4392    }
4393    S += RDecl->isUnion() ? ')' : '}';
4394    return;
4395  }
4396
4397  if (T->isEnumeralType()) {
4398    if (FD && FD->isBitField())
4399      EncodeBitField(this, S, T, FD);
4400    else
4401      S += 'i';
4402    return;
4403  }
4404
4405  if (T->isBlockPointerType()) {
4406    S += "@?"; // Unlike a pointer-to-function, which is "^?".
4407    return;
4408  }
4409
4410  // Ignore protocol qualifiers when mangling at this level.
4411  if (const ObjCObjectType *OT = T->getAs<ObjCObjectType>())
4412    T = OT->getBaseType();
4413
4414  if (const ObjCInterfaceType *OIT = T->getAs<ObjCInterfaceType>()) {
4415    // @encode(class_name)
4416    ObjCInterfaceDecl *OI = OIT->getDecl();
4417    S += '{';
4418    const IdentifierInfo *II = OI->getIdentifier();
4419    S += II->getName();
4420    S += '=';
4421    SmallVector<const ObjCIvarDecl*, 32> Ivars;
4422    DeepCollectObjCIvars(OI, true, Ivars);
4423    for (unsigned i = 0, e = Ivars.size(); i != e; ++i) {
4424      const FieldDecl *Field = cast<FieldDecl>(Ivars[i]);
4425      if (Field->isBitField())
4426        getObjCEncodingForTypeImpl(Field->getType(), S, false, true, Field);
4427      else
4428        getObjCEncodingForTypeImpl(Field->getType(), S, false, true, FD);
4429    }
4430    S += '}';
4431    return;
4432  }
4433
4434  if (const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>()) {
4435    if (OPT->isObjCIdType()) {
4436      S += '@';
4437      return;
4438    }
4439
4440    if (OPT->isObjCClassType() || OPT->isObjCQualifiedClassType()) {
4441      // FIXME: Consider if we need to output qualifiers for 'Class<p>'.
4442      // Since this is a binary compatibility issue, need to consult with runtime
4443      // folks. Fortunately, this is a *very* obsure construct.
4444      S += '#';
4445      return;
4446    }
4447
4448    if (OPT->isObjCQualifiedIdType()) {
4449      getObjCEncodingForTypeImpl(getObjCIdType(), S,
4450                                 ExpandPointedToStructures,
4451                                 ExpandStructures, FD);
4452      if (FD || EncodingProperty) {
4453        // Note that we do extended encoding of protocol qualifer list
4454        // Only when doing ivar or property encoding.
4455        S += '"';
4456        for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
4457             E = OPT->qual_end(); I != E; ++I) {
4458          S += '<';
4459          S += (*I)->getNameAsString();
4460          S += '>';
4461        }
4462        S += '"';
4463      }
4464      return;
4465    }
4466
4467    QualType PointeeTy = OPT->getPointeeType();
4468    if (!EncodingProperty &&
4469        isa<TypedefType>(PointeeTy.getTypePtr())) {
4470      // Another historical/compatibility reason.
4471      // We encode the underlying type which comes out as
4472      // {...};
4473      S += '^';
4474      getObjCEncodingForTypeImpl(PointeeTy, S,
4475                                 false, ExpandPointedToStructures,
4476                                 NULL);
4477      return;
4478    }
4479
4480    S += '@';
4481    if (OPT->getInterfaceDecl() && (FD || EncodingProperty)) {
4482      S += '"';
4483      S += OPT->getInterfaceDecl()->getIdentifier()->getName();
4484      for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
4485           E = OPT->qual_end(); I != E; ++I) {
4486        S += '<';
4487        S += (*I)->getNameAsString();
4488        S += '>';
4489      }
4490      S += '"';
4491    }
4492    return;
4493  }
4494
4495  // gcc just blithely ignores member pointers.
4496  // TODO: maybe there should be a mangling for these
4497  if (T->getAs<MemberPointerType>())
4498    return;
4499
4500  if (T->isVectorType()) {
4501    // This matches gcc's encoding, even though technically it is
4502    // insufficient.
4503    // FIXME. We should do a better job than gcc.
4504    return;
4505  }
4506
4507  assert(0 && "@encode for type not implemented!");
4508}
4509
4510void ASTContext::getObjCEncodingForStructureImpl(RecordDecl *RDecl,
4511                                                 std::string &S,
4512                                                 const FieldDecl *FD,
4513                                                 bool includeVBases) const {
4514  assert(RDecl && "Expected non-null RecordDecl");
4515  assert(!RDecl->isUnion() && "Should not be called for unions");
4516  if (!RDecl->getDefinition())
4517    return;
4518
4519  CXXRecordDecl *CXXRec = dyn_cast<CXXRecordDecl>(RDecl);
4520  std::multimap<uint64_t, NamedDecl *> FieldOrBaseOffsets;
4521  const ASTRecordLayout &layout = getASTRecordLayout(RDecl);
4522
4523  if (CXXRec) {
4524    for (CXXRecordDecl::base_class_iterator
4525           BI = CXXRec->bases_begin(),
4526           BE = CXXRec->bases_end(); BI != BE; ++BI) {
4527      if (!BI->isVirtual()) {
4528        CXXRecordDecl *base = BI->getType()->getAsCXXRecordDecl();
4529        if (base->isEmpty())
4530          continue;
4531        uint64_t offs = layout.getBaseClassOffsetInBits(base);
4532        FieldOrBaseOffsets.insert(FieldOrBaseOffsets.upper_bound(offs),
4533                                  std::make_pair(offs, base));
4534      }
4535    }
4536  }
4537
4538  unsigned i = 0;
4539  for (RecordDecl::field_iterator Field = RDecl->field_begin(),
4540                               FieldEnd = RDecl->field_end();
4541       Field != FieldEnd; ++Field, ++i) {
4542    uint64_t offs = layout.getFieldOffset(i);
4543    FieldOrBaseOffsets.insert(FieldOrBaseOffsets.upper_bound(offs),
4544                              std::make_pair(offs, *Field));
4545  }
4546
4547  if (CXXRec && includeVBases) {
4548    for (CXXRecordDecl::base_class_iterator
4549           BI = CXXRec->vbases_begin(),
4550           BE = CXXRec->vbases_end(); BI != BE; ++BI) {
4551      CXXRecordDecl *base = BI->getType()->getAsCXXRecordDecl();
4552      if (base->isEmpty())
4553        continue;
4554      uint64_t offs = layout.getVBaseClassOffsetInBits(base);
4555      FieldOrBaseOffsets.insert(FieldOrBaseOffsets.upper_bound(offs),
4556                                std::make_pair(offs, base));
4557    }
4558  }
4559
4560  CharUnits size;
4561  if (CXXRec) {
4562    size = includeVBases ? layout.getSize() : layout.getNonVirtualSize();
4563  } else {
4564    size = layout.getSize();
4565  }
4566
4567  uint64_t CurOffs = 0;
4568  std::multimap<uint64_t, NamedDecl *>::iterator
4569    CurLayObj = FieldOrBaseOffsets.begin();
4570
4571  if (CurLayObj != FieldOrBaseOffsets.end() && CurLayObj->first != 0) {
4572    assert(CXXRec && CXXRec->isDynamicClass() &&
4573           "Offset 0 was empty but no VTable ?");
4574    if (FD) {
4575      S += "\"_vptr$";
4576      std::string recname = CXXRec->getNameAsString();
4577      if (recname.empty()) recname = "?";
4578      S += recname;
4579      S += '"';
4580    }
4581    S += "^^?";
4582    CurOffs += getTypeSize(VoidPtrTy);
4583  }
4584
4585  if (!RDecl->hasFlexibleArrayMember()) {
4586    // Mark the end of the structure.
4587    uint64_t offs = toBits(size);
4588    FieldOrBaseOffsets.insert(FieldOrBaseOffsets.upper_bound(offs),
4589                              std::make_pair(offs, (NamedDecl*)0));
4590  }
4591
4592  for (; CurLayObj != FieldOrBaseOffsets.end(); ++CurLayObj) {
4593    assert(CurOffs <= CurLayObj->first);
4594
4595    if (CurOffs < CurLayObj->first) {
4596      uint64_t padding = CurLayObj->first - CurOffs;
4597      // FIXME: There doesn't seem to be a way to indicate in the encoding that
4598      // packing/alignment of members is different that normal, in which case
4599      // the encoding will be out-of-sync with the real layout.
4600      // If the runtime switches to just consider the size of types without
4601      // taking into account alignment, we could make padding explicit in the
4602      // encoding (e.g. using arrays of chars). The encoding strings would be
4603      // longer then though.
4604      CurOffs += padding;
4605    }
4606
4607    NamedDecl *dcl = CurLayObj->second;
4608    if (dcl == 0)
4609      break; // reached end of structure.
4610
4611    if (CXXRecordDecl *base = dyn_cast<CXXRecordDecl>(dcl)) {
4612      // We expand the bases without their virtual bases since those are going
4613      // in the initial structure. Note that this differs from gcc which
4614      // expands virtual bases each time one is encountered in the hierarchy,
4615      // making the encoding type bigger than it really is.
4616      getObjCEncodingForStructureImpl(base, S, FD, /*includeVBases*/false);
4617      assert(!base->isEmpty());
4618      CurOffs += toBits(getASTRecordLayout(base).getNonVirtualSize());
4619    } else {
4620      FieldDecl *field = cast<FieldDecl>(dcl);
4621      if (FD) {
4622        S += '"';
4623        S += field->getNameAsString();
4624        S += '"';
4625      }
4626
4627      if (field->isBitField()) {
4628        EncodeBitField(this, S, field->getType(), field);
4629        CurOffs += field->getBitWidth()->EvaluateAsInt(*this).getZExtValue();
4630      } else {
4631        QualType qt = field->getType();
4632        getLegacyIntegralTypeEncoding(qt);
4633        getObjCEncodingForTypeImpl(qt, S, false, true, FD,
4634                                   /*OutermostType*/false,
4635                                   /*EncodingProperty*/false,
4636                                   /*StructField*/true);
4637        CurOffs += getTypeSize(field->getType());
4638      }
4639    }
4640  }
4641}
4642
4643void ASTContext::getObjCEncodingForTypeQualifier(Decl::ObjCDeclQualifier QT,
4644                                                 std::string& S) const {
4645  if (QT & Decl::OBJC_TQ_In)
4646    S += 'n';
4647  if (QT & Decl::OBJC_TQ_Inout)
4648    S += 'N';
4649  if (QT & Decl::OBJC_TQ_Out)
4650    S += 'o';
4651  if (QT & Decl::OBJC_TQ_Bycopy)
4652    S += 'O';
4653  if (QT & Decl::OBJC_TQ_Byref)
4654    S += 'R';
4655  if (QT & Decl::OBJC_TQ_Oneway)
4656    S += 'V';
4657}
4658
4659void ASTContext::setBuiltinVaListType(QualType T) {
4660  assert(BuiltinVaListType.isNull() && "__builtin_va_list type already set!");
4661
4662  BuiltinVaListType = T;
4663}
4664
4665TypedefDecl *ASTContext::getObjCIdDecl() const {
4666  if (!ObjCIdDecl) {
4667    QualType T = getObjCObjectType(ObjCBuiltinIdTy, 0, 0);
4668    T = getObjCObjectPointerType(T);
4669    TypeSourceInfo *IdInfo = getTrivialTypeSourceInfo(T);
4670    ObjCIdDecl = TypedefDecl::Create(const_cast<ASTContext &>(*this),
4671                                     getTranslationUnitDecl(),
4672                                     SourceLocation(), SourceLocation(),
4673                                     &Idents.get("id"), IdInfo);
4674  }
4675
4676  return ObjCIdDecl;
4677}
4678
4679TypedefDecl *ASTContext::getObjCSelDecl() const {
4680  if (!ObjCSelDecl) {
4681    QualType SelT = getPointerType(ObjCBuiltinSelTy);
4682    TypeSourceInfo *SelInfo = getTrivialTypeSourceInfo(SelT);
4683    ObjCSelDecl = TypedefDecl::Create(const_cast<ASTContext &>(*this),
4684                                      getTranslationUnitDecl(),
4685                                      SourceLocation(), SourceLocation(),
4686                                      &Idents.get("SEL"), SelInfo);
4687  }
4688  return ObjCSelDecl;
4689}
4690
4691void ASTContext::setObjCProtoType(QualType QT) {
4692  ObjCProtoType = QT;
4693}
4694
4695TypedefDecl *ASTContext::getObjCClassDecl() const {
4696  if (!ObjCClassDecl) {
4697    QualType T = getObjCObjectType(ObjCBuiltinClassTy, 0, 0);
4698    T = getObjCObjectPointerType(T);
4699    TypeSourceInfo *ClassInfo = getTrivialTypeSourceInfo(T);
4700    ObjCClassDecl = TypedefDecl::Create(const_cast<ASTContext &>(*this),
4701                                        getTranslationUnitDecl(),
4702                                        SourceLocation(), SourceLocation(),
4703                                        &Idents.get("Class"), ClassInfo);
4704  }
4705
4706  return ObjCClassDecl;
4707}
4708
4709void ASTContext::setObjCConstantStringInterface(ObjCInterfaceDecl *Decl) {
4710  assert(ObjCConstantStringType.isNull() &&
4711         "'NSConstantString' type already set!");
4712
4713  ObjCConstantStringType = getObjCInterfaceType(Decl);
4714}
4715
4716/// \brief Retrieve the template name that corresponds to a non-empty
4717/// lookup.
4718TemplateName
4719ASTContext::getOverloadedTemplateName(UnresolvedSetIterator Begin,
4720                                      UnresolvedSetIterator End) const {
4721  unsigned size = End - Begin;
4722  assert(size > 1 && "set is not overloaded!");
4723
4724  void *memory = Allocate(sizeof(OverloadedTemplateStorage) +
4725                          size * sizeof(FunctionTemplateDecl*));
4726  OverloadedTemplateStorage *OT = new(memory) OverloadedTemplateStorage(size);
4727
4728  NamedDecl **Storage = OT->getStorage();
4729  for (UnresolvedSetIterator I = Begin; I != End; ++I) {
4730    NamedDecl *D = *I;
4731    assert(isa<FunctionTemplateDecl>(D) ||
4732           (isa<UsingShadowDecl>(D) &&
4733            isa<FunctionTemplateDecl>(D->getUnderlyingDecl())));
4734    *Storage++ = D;
4735  }
4736
4737  return TemplateName(OT);
4738}
4739
4740/// \brief Retrieve the template name that represents a qualified
4741/// template name such as \c std::vector.
4742TemplateName
4743ASTContext::getQualifiedTemplateName(NestedNameSpecifier *NNS,
4744                                     bool TemplateKeyword,
4745                                     TemplateDecl *Template) const {
4746  assert(NNS && "Missing nested-name-specifier in qualified template name");
4747
4748  // FIXME: Canonicalization?
4749  llvm::FoldingSetNodeID ID;
4750  QualifiedTemplateName::Profile(ID, NNS, TemplateKeyword, Template);
4751
4752  void *InsertPos = 0;
4753  QualifiedTemplateName *QTN =
4754    QualifiedTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
4755  if (!QTN) {
4756    QTN = new (*this,4) QualifiedTemplateName(NNS, TemplateKeyword, Template);
4757    QualifiedTemplateNames.InsertNode(QTN, InsertPos);
4758  }
4759
4760  return TemplateName(QTN);
4761}
4762
4763/// \brief Retrieve the template name that represents a dependent
4764/// template name such as \c MetaFun::template apply.
4765TemplateName
4766ASTContext::getDependentTemplateName(NestedNameSpecifier *NNS,
4767                                     const IdentifierInfo *Name) const {
4768  assert((!NNS || NNS->isDependent()) &&
4769         "Nested name specifier must be dependent");
4770
4771  llvm::FoldingSetNodeID ID;
4772  DependentTemplateName::Profile(ID, NNS, Name);
4773
4774  void *InsertPos = 0;
4775  DependentTemplateName *QTN =
4776    DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
4777
4778  if (QTN)
4779    return TemplateName(QTN);
4780
4781  NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
4782  if (CanonNNS == NNS) {
4783    QTN = new (*this,4) DependentTemplateName(NNS, Name);
4784  } else {
4785    TemplateName Canon = getDependentTemplateName(CanonNNS, Name);
4786    QTN = new (*this,4) DependentTemplateName(NNS, Name, Canon);
4787    DependentTemplateName *CheckQTN =
4788      DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
4789    assert(!CheckQTN && "Dependent type name canonicalization broken");
4790    (void)CheckQTN;
4791  }
4792
4793  DependentTemplateNames.InsertNode(QTN, InsertPos);
4794  return TemplateName(QTN);
4795}
4796
4797/// \brief Retrieve the template name that represents a dependent
4798/// template name such as \c MetaFun::template operator+.
4799TemplateName
4800ASTContext::getDependentTemplateName(NestedNameSpecifier *NNS,
4801                                     OverloadedOperatorKind Operator) const {
4802  assert((!NNS || NNS->isDependent()) &&
4803         "Nested name specifier must be dependent");
4804
4805  llvm::FoldingSetNodeID ID;
4806  DependentTemplateName::Profile(ID, NNS, Operator);
4807
4808  void *InsertPos = 0;
4809  DependentTemplateName *QTN
4810    = DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
4811
4812  if (QTN)
4813    return TemplateName(QTN);
4814
4815  NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
4816  if (CanonNNS == NNS) {
4817    QTN = new (*this,4) DependentTemplateName(NNS, Operator);
4818  } else {
4819    TemplateName Canon = getDependentTemplateName(CanonNNS, Operator);
4820    QTN = new (*this,4) DependentTemplateName(NNS, Operator, Canon);
4821
4822    DependentTemplateName *CheckQTN
4823      = DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
4824    assert(!CheckQTN && "Dependent template name canonicalization broken");
4825    (void)CheckQTN;
4826  }
4827
4828  DependentTemplateNames.InsertNode(QTN, InsertPos);
4829  return TemplateName(QTN);
4830}
4831
4832TemplateName
4833ASTContext::getSubstTemplateTemplateParm(TemplateTemplateParmDecl *param,
4834                                         TemplateName replacement) const {
4835  llvm::FoldingSetNodeID ID;
4836  SubstTemplateTemplateParmStorage::Profile(ID, param, replacement);
4837
4838  void *insertPos = 0;
4839  SubstTemplateTemplateParmStorage *subst
4840    = SubstTemplateTemplateParms.FindNodeOrInsertPos(ID, insertPos);
4841
4842  if (!subst) {
4843    subst = new (*this) SubstTemplateTemplateParmStorage(param, replacement);
4844    SubstTemplateTemplateParms.InsertNode(subst, insertPos);
4845  }
4846
4847  return TemplateName(subst);
4848}
4849
4850TemplateName
4851ASTContext::getSubstTemplateTemplateParmPack(TemplateTemplateParmDecl *Param,
4852                                       const TemplateArgument &ArgPack) const {
4853  ASTContext &Self = const_cast<ASTContext &>(*this);
4854  llvm::FoldingSetNodeID ID;
4855  SubstTemplateTemplateParmPackStorage::Profile(ID, Self, Param, ArgPack);
4856
4857  void *InsertPos = 0;
4858  SubstTemplateTemplateParmPackStorage *Subst
4859    = SubstTemplateTemplateParmPacks.FindNodeOrInsertPos(ID, InsertPos);
4860
4861  if (!Subst) {
4862    Subst = new (*this) SubstTemplateTemplateParmPackStorage(Param,
4863                                                           ArgPack.pack_size(),
4864                                                         ArgPack.pack_begin());
4865    SubstTemplateTemplateParmPacks.InsertNode(Subst, InsertPos);
4866  }
4867
4868  return TemplateName(Subst);
4869}
4870
4871/// getFromTargetType - Given one of the integer types provided by
4872/// TargetInfo, produce the corresponding type. The unsigned @p Type
4873/// is actually a value of type @c TargetInfo::IntType.
4874CanQualType ASTContext::getFromTargetType(unsigned Type) const {
4875  switch (Type) {
4876  case TargetInfo::NoInt: return CanQualType();
4877  case TargetInfo::SignedShort: return ShortTy;
4878  case TargetInfo::UnsignedShort: return UnsignedShortTy;
4879  case TargetInfo::SignedInt: return IntTy;
4880  case TargetInfo::UnsignedInt: return UnsignedIntTy;
4881  case TargetInfo::SignedLong: return LongTy;
4882  case TargetInfo::UnsignedLong: return UnsignedLongTy;
4883  case TargetInfo::SignedLongLong: return LongLongTy;
4884  case TargetInfo::UnsignedLongLong: return UnsignedLongLongTy;
4885  }
4886
4887  assert(false && "Unhandled TargetInfo::IntType value");
4888  return CanQualType();
4889}
4890
4891//===----------------------------------------------------------------------===//
4892//                        Type Predicates.
4893//===----------------------------------------------------------------------===//
4894
4895/// getObjCGCAttr - Returns one of GCNone, Weak or Strong objc's
4896/// garbage collection attribute.
4897///
4898Qualifiers::GC ASTContext::getObjCGCAttrKind(QualType Ty) const {
4899  if (getLangOptions().getGCMode() == LangOptions::NonGC)
4900    return Qualifiers::GCNone;
4901
4902  assert(getLangOptions().ObjC1);
4903  Qualifiers::GC GCAttrs = Ty.getObjCGCAttr();
4904
4905  // Default behaviour under objective-C's gc is for ObjC pointers
4906  // (or pointers to them) be treated as though they were declared
4907  // as __strong.
4908  if (GCAttrs == Qualifiers::GCNone) {
4909    if (Ty->isObjCObjectPointerType() || Ty->isBlockPointerType())
4910      return Qualifiers::Strong;
4911    else if (Ty->isPointerType())
4912      return getObjCGCAttrKind(Ty->getAs<PointerType>()->getPointeeType());
4913  } else {
4914    // It's not valid to set GC attributes on anything that isn't a
4915    // pointer.
4916#ifndef NDEBUG
4917    QualType CT = Ty->getCanonicalTypeInternal();
4918    while (const ArrayType *AT = dyn_cast<ArrayType>(CT))
4919      CT = AT->getElementType();
4920    assert(CT->isAnyPointerType() || CT->isBlockPointerType());
4921#endif
4922  }
4923  return GCAttrs;
4924}
4925
4926//===----------------------------------------------------------------------===//
4927//                        Type Compatibility Testing
4928//===----------------------------------------------------------------------===//
4929
4930/// areCompatVectorTypes - Return true if the two specified vector types are
4931/// compatible.
4932static bool areCompatVectorTypes(const VectorType *LHS,
4933                                 const VectorType *RHS) {
4934  assert(LHS->isCanonicalUnqualified() && RHS->isCanonicalUnqualified());
4935  return LHS->getElementType() == RHS->getElementType() &&
4936         LHS->getNumElements() == RHS->getNumElements();
4937}
4938
4939bool ASTContext::areCompatibleVectorTypes(QualType FirstVec,
4940                                          QualType SecondVec) {
4941  assert(FirstVec->isVectorType() && "FirstVec should be a vector type");
4942  assert(SecondVec->isVectorType() && "SecondVec should be a vector type");
4943
4944  if (hasSameUnqualifiedType(FirstVec, SecondVec))
4945    return true;
4946
4947  // Treat Neon vector types and most AltiVec vector types as if they are the
4948  // equivalent GCC vector types.
4949  const VectorType *First = FirstVec->getAs<VectorType>();
4950  const VectorType *Second = SecondVec->getAs<VectorType>();
4951  if (First->getNumElements() == Second->getNumElements() &&
4952      hasSameType(First->getElementType(), Second->getElementType()) &&
4953      First->getVectorKind() != VectorType::AltiVecPixel &&
4954      First->getVectorKind() != VectorType::AltiVecBool &&
4955      Second->getVectorKind() != VectorType::AltiVecPixel &&
4956      Second->getVectorKind() != VectorType::AltiVecBool)
4957    return true;
4958
4959  return false;
4960}
4961
4962//===----------------------------------------------------------------------===//
4963// ObjCQualifiedIdTypesAreCompatible - Compatibility testing for qualified id's.
4964//===----------------------------------------------------------------------===//
4965
4966/// ProtocolCompatibleWithProtocol - return 'true' if 'lProto' is in the
4967/// inheritance hierarchy of 'rProto'.
4968bool
4969ASTContext::ProtocolCompatibleWithProtocol(ObjCProtocolDecl *lProto,
4970                                           ObjCProtocolDecl *rProto) const {
4971  if (lProto == rProto)
4972    return true;
4973  for (ObjCProtocolDecl::protocol_iterator PI = rProto->protocol_begin(),
4974       E = rProto->protocol_end(); PI != E; ++PI)
4975    if (ProtocolCompatibleWithProtocol(lProto, *PI))
4976      return true;
4977  return false;
4978}
4979
4980/// QualifiedIdConformsQualifiedId - compare id<p,...> with id<p1,...>
4981/// return true if lhs's protocols conform to rhs's protocol; false
4982/// otherwise.
4983bool ASTContext::QualifiedIdConformsQualifiedId(QualType lhs, QualType rhs) {
4984  if (lhs->isObjCQualifiedIdType() && rhs->isObjCQualifiedIdType())
4985    return ObjCQualifiedIdTypesAreCompatible(lhs, rhs, false);
4986  return false;
4987}
4988
4989/// ObjCQualifiedClassTypesAreCompatible - compare  Class<p,...> and
4990/// Class<p1, ...>.
4991bool ASTContext::ObjCQualifiedClassTypesAreCompatible(QualType lhs,
4992                                                      QualType rhs) {
4993  const ObjCObjectPointerType *lhsQID = lhs->getAs<ObjCObjectPointerType>();
4994  const ObjCObjectPointerType *rhsOPT = rhs->getAs<ObjCObjectPointerType>();
4995  assert ((lhsQID && rhsOPT) && "ObjCQualifiedClassTypesAreCompatible");
4996
4997  for (ObjCObjectPointerType::qual_iterator I = lhsQID->qual_begin(),
4998       E = lhsQID->qual_end(); I != E; ++I) {
4999    bool match = false;
5000    ObjCProtocolDecl *lhsProto = *I;
5001    for (ObjCObjectPointerType::qual_iterator J = rhsOPT->qual_begin(),
5002         E = rhsOPT->qual_end(); J != E; ++J) {
5003      ObjCProtocolDecl *rhsProto = *J;
5004      if (ProtocolCompatibleWithProtocol(lhsProto, rhsProto)) {
5005        match = true;
5006        break;
5007      }
5008    }
5009    if (!match)
5010      return false;
5011  }
5012  return true;
5013}
5014
5015/// ObjCQualifiedIdTypesAreCompatible - We know that one of lhs/rhs is an
5016/// ObjCQualifiedIDType.
5017bool ASTContext::ObjCQualifiedIdTypesAreCompatible(QualType lhs, QualType rhs,
5018                                                   bool compare) {
5019  // Allow id<P..> and an 'id' or void* type in all cases.
5020  if (lhs->isVoidPointerType() ||
5021      lhs->isObjCIdType() || lhs->isObjCClassType())
5022    return true;
5023  else if (rhs->isVoidPointerType() ||
5024           rhs->isObjCIdType() || rhs->isObjCClassType())
5025    return true;
5026
5027  if (const ObjCObjectPointerType *lhsQID = lhs->getAsObjCQualifiedIdType()) {
5028    const ObjCObjectPointerType *rhsOPT = rhs->getAs<ObjCObjectPointerType>();
5029
5030    if (!rhsOPT) return false;
5031
5032    if (rhsOPT->qual_empty()) {
5033      // If the RHS is a unqualified interface pointer "NSString*",
5034      // make sure we check the class hierarchy.
5035      if (ObjCInterfaceDecl *rhsID = rhsOPT->getInterfaceDecl()) {
5036        for (ObjCObjectPointerType::qual_iterator I = lhsQID->qual_begin(),
5037             E = lhsQID->qual_end(); I != E; ++I) {
5038          // when comparing an id<P> on lhs with a static type on rhs,
5039          // see if static class implements all of id's protocols, directly or
5040          // through its super class and categories.
5041          if (!rhsID->ClassImplementsProtocol(*I, true))
5042            return false;
5043        }
5044      }
5045      // If there are no qualifiers and no interface, we have an 'id'.
5046      return true;
5047    }
5048    // Both the right and left sides have qualifiers.
5049    for (ObjCObjectPointerType::qual_iterator I = lhsQID->qual_begin(),
5050         E = lhsQID->qual_end(); I != E; ++I) {
5051      ObjCProtocolDecl *lhsProto = *I;
5052      bool match = false;
5053
5054      // when comparing an id<P> on lhs with a static type on rhs,
5055      // see if static class implements all of id's protocols, directly or
5056      // through its super class and categories.
5057      for (ObjCObjectPointerType::qual_iterator J = rhsOPT->qual_begin(),
5058           E = rhsOPT->qual_end(); J != E; ++J) {
5059        ObjCProtocolDecl *rhsProto = *J;
5060        if (ProtocolCompatibleWithProtocol(lhsProto, rhsProto) ||
5061            (compare && ProtocolCompatibleWithProtocol(rhsProto, lhsProto))) {
5062          match = true;
5063          break;
5064        }
5065      }
5066      // If the RHS is a qualified interface pointer "NSString<P>*",
5067      // make sure we check the class hierarchy.
5068      if (ObjCInterfaceDecl *rhsID = rhsOPT->getInterfaceDecl()) {
5069        for (ObjCObjectPointerType::qual_iterator I = lhsQID->qual_begin(),
5070             E = lhsQID->qual_end(); I != E; ++I) {
5071          // when comparing an id<P> on lhs with a static type on rhs,
5072          // see if static class implements all of id's protocols, directly or
5073          // through its super class and categories.
5074          if (rhsID->ClassImplementsProtocol(*I, true)) {
5075            match = true;
5076            break;
5077          }
5078        }
5079      }
5080      if (!match)
5081        return false;
5082    }
5083
5084    return true;
5085  }
5086
5087  const ObjCObjectPointerType *rhsQID = rhs->getAsObjCQualifiedIdType();
5088  assert(rhsQID && "One of the LHS/RHS should be id<x>");
5089
5090  if (const ObjCObjectPointerType *lhsOPT =
5091        lhs->getAsObjCInterfacePointerType()) {
5092    // If both the right and left sides have qualifiers.
5093    for (ObjCObjectPointerType::qual_iterator I = lhsOPT->qual_begin(),
5094         E = lhsOPT->qual_end(); I != E; ++I) {
5095      ObjCProtocolDecl *lhsProto = *I;
5096      bool match = false;
5097
5098      // when comparing an id<P> on rhs with a static type on lhs,
5099      // see if static class implements all of id's protocols, directly or
5100      // through its super class and categories.
5101      // First, lhs protocols in the qualifier list must be found, direct
5102      // or indirect in rhs's qualifier list or it is a mismatch.
5103      for (ObjCObjectPointerType::qual_iterator J = rhsQID->qual_begin(),
5104           E = rhsQID->qual_end(); J != E; ++J) {
5105        ObjCProtocolDecl *rhsProto = *J;
5106        if (ProtocolCompatibleWithProtocol(lhsProto, rhsProto) ||
5107            (compare && ProtocolCompatibleWithProtocol(rhsProto, lhsProto))) {
5108          match = true;
5109          break;
5110        }
5111      }
5112      if (!match)
5113        return false;
5114    }
5115
5116    // Static class's protocols, or its super class or category protocols
5117    // must be found, direct or indirect in rhs's qualifier list or it is a mismatch.
5118    if (ObjCInterfaceDecl *lhsID = lhsOPT->getInterfaceDecl()) {
5119      llvm::SmallPtrSet<ObjCProtocolDecl *, 8> LHSInheritedProtocols;
5120      CollectInheritedProtocols(lhsID, LHSInheritedProtocols);
5121      // This is rather dubious but matches gcc's behavior. If lhs has
5122      // no type qualifier and its class has no static protocol(s)
5123      // assume that it is mismatch.
5124      if (LHSInheritedProtocols.empty() && lhsOPT->qual_empty())
5125        return false;
5126      for (llvm::SmallPtrSet<ObjCProtocolDecl*,8>::iterator I =
5127           LHSInheritedProtocols.begin(),
5128           E = LHSInheritedProtocols.end(); I != E; ++I) {
5129        bool match = false;
5130        ObjCProtocolDecl *lhsProto = (*I);
5131        for (ObjCObjectPointerType::qual_iterator J = rhsQID->qual_begin(),
5132             E = rhsQID->qual_end(); J != E; ++J) {
5133          ObjCProtocolDecl *rhsProto = *J;
5134          if (ProtocolCompatibleWithProtocol(lhsProto, rhsProto) ||
5135              (compare && ProtocolCompatibleWithProtocol(rhsProto, lhsProto))) {
5136            match = true;
5137            break;
5138          }
5139        }
5140        if (!match)
5141          return false;
5142      }
5143    }
5144    return true;
5145  }
5146  return false;
5147}
5148
5149/// canAssignObjCInterfaces - Return true if the two interface types are
5150/// compatible for assignment from RHS to LHS.  This handles validation of any
5151/// protocol qualifiers on the LHS or RHS.
5152///
5153bool ASTContext::canAssignObjCInterfaces(const ObjCObjectPointerType *LHSOPT,
5154                                         const ObjCObjectPointerType *RHSOPT) {
5155  const ObjCObjectType* LHS = LHSOPT->getObjectType();
5156  const ObjCObjectType* RHS = RHSOPT->getObjectType();
5157
5158  // If either type represents the built-in 'id' or 'Class' types, return true.
5159  if (LHS->isObjCUnqualifiedIdOrClass() ||
5160      RHS->isObjCUnqualifiedIdOrClass())
5161    return true;
5162
5163  if (LHS->isObjCQualifiedId() || RHS->isObjCQualifiedId())
5164    return ObjCQualifiedIdTypesAreCompatible(QualType(LHSOPT,0),
5165                                             QualType(RHSOPT,0),
5166                                             false);
5167
5168  if (LHS->isObjCQualifiedClass() && RHS->isObjCQualifiedClass())
5169    return ObjCQualifiedClassTypesAreCompatible(QualType(LHSOPT,0),
5170                                                QualType(RHSOPT,0));
5171
5172  // If we have 2 user-defined types, fall into that path.
5173  if (LHS->getInterface() && RHS->getInterface())
5174    return canAssignObjCInterfaces(LHS, RHS);
5175
5176  return false;
5177}
5178
5179/// canAssignObjCInterfacesInBlockPointer - This routine is specifically written
5180/// for providing type-safety for objective-c pointers used to pass/return
5181/// arguments in block literals. When passed as arguments, passing 'A*' where
5182/// 'id' is expected is not OK. Passing 'Sub *" where 'Super *" is expected is
5183/// not OK. For the return type, the opposite is not OK.
5184bool ASTContext::canAssignObjCInterfacesInBlockPointer(
5185                                         const ObjCObjectPointerType *LHSOPT,
5186                                         const ObjCObjectPointerType *RHSOPT,
5187                                         bool BlockReturnType) {
5188  if (RHSOPT->isObjCBuiltinType() || LHSOPT->isObjCIdType())
5189    return true;
5190
5191  if (LHSOPT->isObjCBuiltinType()) {
5192    return RHSOPT->isObjCBuiltinType() || RHSOPT->isObjCQualifiedIdType();
5193  }
5194
5195  if (LHSOPT->isObjCQualifiedIdType() || RHSOPT->isObjCQualifiedIdType())
5196    return ObjCQualifiedIdTypesAreCompatible(QualType(LHSOPT,0),
5197                                             QualType(RHSOPT,0),
5198                                             false);
5199
5200  const ObjCInterfaceType* LHS = LHSOPT->getInterfaceType();
5201  const ObjCInterfaceType* RHS = RHSOPT->getInterfaceType();
5202  if (LHS && RHS)  { // We have 2 user-defined types.
5203    if (LHS != RHS) {
5204      if (LHS->getDecl()->isSuperClassOf(RHS->getDecl()))
5205        return BlockReturnType;
5206      if (RHS->getDecl()->isSuperClassOf(LHS->getDecl()))
5207        return !BlockReturnType;
5208    }
5209    else
5210      return true;
5211  }
5212  return false;
5213}
5214
5215/// getIntersectionOfProtocols - This routine finds the intersection of set
5216/// of protocols inherited from two distinct objective-c pointer objects.
5217/// It is used to build composite qualifier list of the composite type of
5218/// the conditional expression involving two objective-c pointer objects.
5219static
5220void getIntersectionOfProtocols(ASTContext &Context,
5221                                const ObjCObjectPointerType *LHSOPT,
5222                                const ObjCObjectPointerType *RHSOPT,
5223      SmallVectorImpl<ObjCProtocolDecl *> &IntersectionOfProtocols) {
5224
5225  const ObjCObjectType* LHS = LHSOPT->getObjectType();
5226  const ObjCObjectType* RHS = RHSOPT->getObjectType();
5227  assert(LHS->getInterface() && "LHS must have an interface base");
5228  assert(RHS->getInterface() && "RHS must have an interface base");
5229
5230  llvm::SmallPtrSet<ObjCProtocolDecl *, 8> InheritedProtocolSet;
5231  unsigned LHSNumProtocols = LHS->getNumProtocols();
5232  if (LHSNumProtocols > 0)
5233    InheritedProtocolSet.insert(LHS->qual_begin(), LHS->qual_end());
5234  else {
5235    llvm::SmallPtrSet<ObjCProtocolDecl *, 8> LHSInheritedProtocols;
5236    Context.CollectInheritedProtocols(LHS->getInterface(),
5237                                      LHSInheritedProtocols);
5238    InheritedProtocolSet.insert(LHSInheritedProtocols.begin(),
5239                                LHSInheritedProtocols.end());
5240  }
5241
5242  unsigned RHSNumProtocols = RHS->getNumProtocols();
5243  if (RHSNumProtocols > 0) {
5244    ObjCProtocolDecl **RHSProtocols =
5245      const_cast<ObjCProtocolDecl **>(RHS->qual_begin());
5246    for (unsigned i = 0; i < RHSNumProtocols; ++i)
5247      if (InheritedProtocolSet.count(RHSProtocols[i]))
5248        IntersectionOfProtocols.push_back(RHSProtocols[i]);
5249  }
5250  else {
5251    llvm::SmallPtrSet<ObjCProtocolDecl *, 8> RHSInheritedProtocols;
5252    Context.CollectInheritedProtocols(RHS->getInterface(),
5253                                      RHSInheritedProtocols);
5254    for (llvm::SmallPtrSet<ObjCProtocolDecl*,8>::iterator I =
5255         RHSInheritedProtocols.begin(),
5256         E = RHSInheritedProtocols.end(); I != E; ++I)
5257      if (InheritedProtocolSet.count((*I)))
5258        IntersectionOfProtocols.push_back((*I));
5259  }
5260}
5261
5262/// areCommonBaseCompatible - Returns common base class of the two classes if
5263/// one found. Note that this is O'2 algorithm. But it will be called as the
5264/// last type comparison in a ?-exp of ObjC pointer types before a
5265/// warning is issued. So, its invokation is extremely rare.
5266QualType ASTContext::areCommonBaseCompatible(
5267                                          const ObjCObjectPointerType *Lptr,
5268                                          const ObjCObjectPointerType *Rptr) {
5269  const ObjCObjectType *LHS = Lptr->getObjectType();
5270  const ObjCObjectType *RHS = Rptr->getObjectType();
5271  const ObjCInterfaceDecl* LDecl = LHS->getInterface();
5272  const ObjCInterfaceDecl* RDecl = RHS->getInterface();
5273  if (!LDecl || !RDecl || (LDecl == RDecl))
5274    return QualType();
5275
5276  do {
5277    LHS = cast<ObjCInterfaceType>(getObjCInterfaceType(LDecl));
5278    if (canAssignObjCInterfaces(LHS, RHS)) {
5279      SmallVector<ObjCProtocolDecl *, 8> Protocols;
5280      getIntersectionOfProtocols(*this, Lptr, Rptr, Protocols);
5281
5282      QualType Result = QualType(LHS, 0);
5283      if (!Protocols.empty())
5284        Result = getObjCObjectType(Result, Protocols.data(), Protocols.size());
5285      Result = getObjCObjectPointerType(Result);
5286      return Result;
5287    }
5288  } while ((LDecl = LDecl->getSuperClass()));
5289
5290  return QualType();
5291}
5292
5293bool ASTContext::canAssignObjCInterfaces(const ObjCObjectType *LHS,
5294                                         const ObjCObjectType *RHS) {
5295  assert(LHS->getInterface() && "LHS is not an interface type");
5296  assert(RHS->getInterface() && "RHS is not an interface type");
5297
5298  // Verify that the base decls are compatible: the RHS must be a subclass of
5299  // the LHS.
5300  if (!LHS->getInterface()->isSuperClassOf(RHS->getInterface()))
5301    return false;
5302
5303  // RHS must have a superset of the protocols in the LHS.  If the LHS is not
5304  // protocol qualified at all, then we are good.
5305  if (LHS->getNumProtocols() == 0)
5306    return true;
5307
5308  // Okay, we know the LHS has protocol qualifiers.  If the RHS doesn't,
5309  // more detailed analysis is required.
5310  if (RHS->getNumProtocols() == 0) {
5311    // OK, if LHS is a superclass of RHS *and*
5312    // this superclass is assignment compatible with LHS.
5313    // false otherwise.
5314    bool IsSuperClass =
5315      LHS->getInterface()->isSuperClassOf(RHS->getInterface());
5316    if (IsSuperClass) {
5317      // OK if conversion of LHS to SuperClass results in narrowing of types
5318      // ; i.e., SuperClass may implement at least one of the protocols
5319      // in LHS's protocol list. Example, SuperObj<P1> = lhs<P1,P2> is ok.
5320      // But not SuperObj<P1,P2,P3> = lhs<P1,P2>.
5321      llvm::SmallPtrSet<ObjCProtocolDecl *, 8> SuperClassInheritedProtocols;
5322      CollectInheritedProtocols(RHS->getInterface(), SuperClassInheritedProtocols);
5323      // If super class has no protocols, it is not a match.
5324      if (SuperClassInheritedProtocols.empty())
5325        return false;
5326
5327      for (ObjCObjectType::qual_iterator LHSPI = LHS->qual_begin(),
5328           LHSPE = LHS->qual_end();
5329           LHSPI != LHSPE; LHSPI++) {
5330        bool SuperImplementsProtocol = false;
5331        ObjCProtocolDecl *LHSProto = (*LHSPI);
5332
5333        for (llvm::SmallPtrSet<ObjCProtocolDecl*,8>::iterator I =
5334             SuperClassInheritedProtocols.begin(),
5335             E = SuperClassInheritedProtocols.end(); I != E; ++I) {
5336          ObjCProtocolDecl *SuperClassProto = (*I);
5337          if (SuperClassProto->lookupProtocolNamed(LHSProto->getIdentifier())) {
5338            SuperImplementsProtocol = true;
5339            break;
5340          }
5341        }
5342        if (!SuperImplementsProtocol)
5343          return false;
5344      }
5345      return true;
5346    }
5347    return false;
5348  }
5349
5350  for (ObjCObjectType::qual_iterator LHSPI = LHS->qual_begin(),
5351                                     LHSPE = LHS->qual_end();
5352       LHSPI != LHSPE; LHSPI++) {
5353    bool RHSImplementsProtocol = false;
5354
5355    // If the RHS doesn't implement the protocol on the left, the types
5356    // are incompatible.
5357    for (ObjCObjectType::qual_iterator RHSPI = RHS->qual_begin(),
5358                                       RHSPE = RHS->qual_end();
5359         RHSPI != RHSPE; RHSPI++) {
5360      if ((*RHSPI)->lookupProtocolNamed((*LHSPI)->getIdentifier())) {
5361        RHSImplementsProtocol = true;
5362        break;
5363      }
5364    }
5365    // FIXME: For better diagnostics, consider passing back the protocol name.
5366    if (!RHSImplementsProtocol)
5367      return false;
5368  }
5369  // The RHS implements all protocols listed on the LHS.
5370  return true;
5371}
5372
5373bool ASTContext::areComparableObjCPointerTypes(QualType LHS, QualType RHS) {
5374  // get the "pointed to" types
5375  const ObjCObjectPointerType *LHSOPT = LHS->getAs<ObjCObjectPointerType>();
5376  const ObjCObjectPointerType *RHSOPT = RHS->getAs<ObjCObjectPointerType>();
5377
5378  if (!LHSOPT || !RHSOPT)
5379    return false;
5380
5381  return canAssignObjCInterfaces(LHSOPT, RHSOPT) ||
5382         canAssignObjCInterfaces(RHSOPT, LHSOPT);
5383}
5384
5385bool ASTContext::canBindObjCObjectType(QualType To, QualType From) {
5386  return canAssignObjCInterfaces(
5387                getObjCObjectPointerType(To)->getAs<ObjCObjectPointerType>(),
5388                getObjCObjectPointerType(From)->getAs<ObjCObjectPointerType>());
5389}
5390
5391/// typesAreCompatible - C99 6.7.3p9: For two qualified types to be compatible,
5392/// both shall have the identically qualified version of a compatible type.
5393/// C99 6.2.7p1: Two types have compatible types if their types are the
5394/// same. See 6.7.[2,3,5] for additional rules.
5395bool ASTContext::typesAreCompatible(QualType LHS, QualType RHS,
5396                                    bool CompareUnqualified) {
5397  if (getLangOptions().CPlusPlus)
5398    return hasSameType(LHS, RHS);
5399
5400  return !mergeTypes(LHS, RHS, false, CompareUnqualified).isNull();
5401}
5402
5403bool ASTContext::propertyTypesAreCompatible(QualType LHS, QualType RHS) {
5404  return typesAreCompatible(LHS, RHS);
5405}
5406
5407bool ASTContext::typesAreBlockPointerCompatible(QualType LHS, QualType RHS) {
5408  return !mergeTypes(LHS, RHS, true).isNull();
5409}
5410
5411/// mergeTransparentUnionType - if T is a transparent union type and a member
5412/// of T is compatible with SubType, return the merged type, else return
5413/// QualType()
5414QualType ASTContext::mergeTransparentUnionType(QualType T, QualType SubType,
5415                                               bool OfBlockPointer,
5416                                               bool Unqualified) {
5417  if (const RecordType *UT = T->getAsUnionType()) {
5418    RecordDecl *UD = UT->getDecl();
5419    if (UD->hasAttr<TransparentUnionAttr>()) {
5420      for (RecordDecl::field_iterator it = UD->field_begin(),
5421           itend = UD->field_end(); it != itend; ++it) {
5422        QualType ET = it->getType().getUnqualifiedType();
5423        QualType MT = mergeTypes(ET, SubType, OfBlockPointer, Unqualified);
5424        if (!MT.isNull())
5425          return MT;
5426      }
5427    }
5428  }
5429
5430  return QualType();
5431}
5432
5433/// mergeFunctionArgumentTypes - merge two types which appear as function
5434/// argument types
5435QualType ASTContext::mergeFunctionArgumentTypes(QualType lhs, QualType rhs,
5436                                                bool OfBlockPointer,
5437                                                bool Unqualified) {
5438  // GNU extension: two types are compatible if they appear as a function
5439  // argument, one of the types is a transparent union type and the other
5440  // type is compatible with a union member
5441  QualType lmerge = mergeTransparentUnionType(lhs, rhs, OfBlockPointer,
5442                                              Unqualified);
5443  if (!lmerge.isNull())
5444    return lmerge;
5445
5446  QualType rmerge = mergeTransparentUnionType(rhs, lhs, OfBlockPointer,
5447                                              Unqualified);
5448  if (!rmerge.isNull())
5449    return rmerge;
5450
5451  return mergeTypes(lhs, rhs, OfBlockPointer, Unqualified);
5452}
5453
5454QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
5455                                        bool OfBlockPointer,
5456                                        bool Unqualified) {
5457  const FunctionType *lbase = lhs->getAs<FunctionType>();
5458  const FunctionType *rbase = rhs->getAs<FunctionType>();
5459  const FunctionProtoType *lproto = dyn_cast<FunctionProtoType>(lbase);
5460  const FunctionProtoType *rproto = dyn_cast<FunctionProtoType>(rbase);
5461  bool allLTypes = true;
5462  bool allRTypes = true;
5463
5464  // Check return type
5465  QualType retType;
5466  if (OfBlockPointer) {
5467    QualType RHS = rbase->getResultType();
5468    QualType LHS = lbase->getResultType();
5469    bool UnqualifiedResult = Unqualified;
5470    if (!UnqualifiedResult)
5471      UnqualifiedResult = (!RHS.hasQualifiers() && LHS.hasQualifiers());
5472    retType = mergeTypes(LHS, RHS, true, UnqualifiedResult, true);
5473  }
5474  else
5475    retType = mergeTypes(lbase->getResultType(), rbase->getResultType(), false,
5476                         Unqualified);
5477  if (retType.isNull()) return QualType();
5478
5479  if (Unqualified)
5480    retType = retType.getUnqualifiedType();
5481
5482  CanQualType LRetType = getCanonicalType(lbase->getResultType());
5483  CanQualType RRetType = getCanonicalType(rbase->getResultType());
5484  if (Unqualified) {
5485    LRetType = LRetType.getUnqualifiedType();
5486    RRetType = RRetType.getUnqualifiedType();
5487  }
5488
5489  if (getCanonicalType(retType) != LRetType)
5490    allLTypes = false;
5491  if (getCanonicalType(retType) != RRetType)
5492    allRTypes = false;
5493
5494  // FIXME: double check this
5495  // FIXME: should we error if lbase->getRegParmAttr() != 0 &&
5496  //                           rbase->getRegParmAttr() != 0 &&
5497  //                           lbase->getRegParmAttr() != rbase->getRegParmAttr()?
5498  FunctionType::ExtInfo lbaseInfo = lbase->getExtInfo();
5499  FunctionType::ExtInfo rbaseInfo = rbase->getExtInfo();
5500
5501  // Compatible functions must have compatible calling conventions
5502  if (!isSameCallConv(lbaseInfo.getCC(), rbaseInfo.getCC()))
5503    return QualType();
5504
5505  // Regparm is part of the calling convention.
5506  if (lbaseInfo.getHasRegParm() != rbaseInfo.getHasRegParm())
5507    return QualType();
5508  if (lbaseInfo.getRegParm() != rbaseInfo.getRegParm())
5509    return QualType();
5510
5511  if (lbaseInfo.getProducesResult() != rbaseInfo.getProducesResult())
5512    return QualType();
5513
5514  // It's noreturn if either type is.
5515  // FIXME: some uses, e.g. conditional exprs, really want this to be 'both'.
5516  bool NoReturn = lbaseInfo.getNoReturn() || rbaseInfo.getNoReturn();
5517  if (NoReturn != lbaseInfo.getNoReturn())
5518    allLTypes = false;
5519  if (NoReturn != rbaseInfo.getNoReturn())
5520    allRTypes = false;
5521
5522  FunctionType::ExtInfo einfo = lbaseInfo.withNoReturn(NoReturn);
5523
5524  if (lproto && rproto) { // two C99 style function prototypes
5525    assert(!lproto->hasExceptionSpec() && !rproto->hasExceptionSpec() &&
5526           "C++ shouldn't be here");
5527    unsigned lproto_nargs = lproto->getNumArgs();
5528    unsigned rproto_nargs = rproto->getNumArgs();
5529
5530    // Compatible functions must have the same number of arguments
5531    if (lproto_nargs != rproto_nargs)
5532      return QualType();
5533
5534    // Variadic and non-variadic functions aren't compatible
5535    if (lproto->isVariadic() != rproto->isVariadic())
5536      return QualType();
5537
5538    if (lproto->getTypeQuals() != rproto->getTypeQuals())
5539      return QualType();
5540
5541    // Check argument compatibility
5542    SmallVector<QualType, 10> types;
5543    for (unsigned i = 0; i < lproto_nargs; i++) {
5544      QualType largtype = lproto->getArgType(i).getUnqualifiedType();
5545      QualType rargtype = rproto->getArgType(i).getUnqualifiedType();
5546      QualType argtype = mergeFunctionArgumentTypes(largtype, rargtype,
5547                                                    OfBlockPointer,
5548                                                    Unqualified);
5549      if (argtype.isNull()) return QualType();
5550
5551      if (Unqualified)
5552        argtype = argtype.getUnqualifiedType();
5553
5554      types.push_back(argtype);
5555      if (Unqualified) {
5556        largtype = largtype.getUnqualifiedType();
5557        rargtype = rargtype.getUnqualifiedType();
5558      }
5559
5560      if (getCanonicalType(argtype) != getCanonicalType(largtype))
5561        allLTypes = false;
5562      if (getCanonicalType(argtype) != getCanonicalType(rargtype))
5563        allRTypes = false;
5564    }
5565    if (allLTypes) return lhs;
5566    if (allRTypes) return rhs;
5567
5568    FunctionProtoType::ExtProtoInfo EPI = lproto->getExtProtoInfo();
5569    EPI.ExtInfo = einfo;
5570    return getFunctionType(retType, types.begin(), types.size(), EPI);
5571  }
5572
5573  if (lproto) allRTypes = false;
5574  if (rproto) allLTypes = false;
5575
5576  const FunctionProtoType *proto = lproto ? lproto : rproto;
5577  if (proto) {
5578    assert(!proto->hasExceptionSpec() && "C++ shouldn't be here");
5579    if (proto->isVariadic()) return QualType();
5580    // Check that the types are compatible with the types that
5581    // would result from default argument promotions (C99 6.7.5.3p15).
5582    // The only types actually affected are promotable integer
5583    // types and floats, which would be passed as a different
5584    // type depending on whether the prototype is visible.
5585    unsigned proto_nargs = proto->getNumArgs();
5586    for (unsigned i = 0; i < proto_nargs; ++i) {
5587      QualType argTy = proto->getArgType(i);
5588
5589      // Look at the promotion type of enum types, since that is the type used
5590      // to pass enum values.
5591      if (const EnumType *Enum = argTy->getAs<EnumType>())
5592        argTy = Enum->getDecl()->getPromotionType();
5593
5594      if (argTy->isPromotableIntegerType() ||
5595          getCanonicalType(argTy).getUnqualifiedType() == FloatTy)
5596        return QualType();
5597    }
5598
5599    if (allLTypes) return lhs;
5600    if (allRTypes) return rhs;
5601
5602    FunctionProtoType::ExtProtoInfo EPI = proto->getExtProtoInfo();
5603    EPI.ExtInfo = einfo;
5604    return getFunctionType(retType, proto->arg_type_begin(),
5605                           proto->getNumArgs(), EPI);
5606  }
5607
5608  if (allLTypes) return lhs;
5609  if (allRTypes) return rhs;
5610  return getFunctionNoProtoType(retType, einfo);
5611}
5612
5613QualType ASTContext::mergeTypes(QualType LHS, QualType RHS,
5614                                bool OfBlockPointer,
5615                                bool Unqualified, bool BlockReturnType) {
5616  // C++ [expr]: If an expression initially has the type "reference to T", the
5617  // type is adjusted to "T" prior to any further analysis, the expression
5618  // designates the object or function denoted by the reference, and the
5619  // expression is an lvalue unless the reference is an rvalue reference and
5620  // the expression is a function call (possibly inside parentheses).
5621  assert(!LHS->getAs<ReferenceType>() && "LHS is a reference type?");
5622  assert(!RHS->getAs<ReferenceType>() && "RHS is a reference type?");
5623
5624  if (Unqualified) {
5625    LHS = LHS.getUnqualifiedType();
5626    RHS = RHS.getUnqualifiedType();
5627  }
5628
5629  QualType LHSCan = getCanonicalType(LHS),
5630           RHSCan = getCanonicalType(RHS);
5631
5632  // If two types are identical, they are compatible.
5633  if (LHSCan == RHSCan)
5634    return LHS;
5635
5636  // If the qualifiers are different, the types aren't compatible... mostly.
5637  Qualifiers LQuals = LHSCan.getLocalQualifiers();
5638  Qualifiers RQuals = RHSCan.getLocalQualifiers();
5639  if (LQuals != RQuals) {
5640    // If any of these qualifiers are different, we have a type
5641    // mismatch.
5642    if (LQuals.getCVRQualifiers() != RQuals.getCVRQualifiers() ||
5643        LQuals.getAddressSpace() != RQuals.getAddressSpace() ||
5644        LQuals.getObjCLifetime() != RQuals.getObjCLifetime())
5645      return QualType();
5646
5647    // Exactly one GC qualifier difference is allowed: __strong is
5648    // okay if the other type has no GC qualifier but is an Objective
5649    // C object pointer (i.e. implicitly strong by default).  We fix
5650    // this by pretending that the unqualified type was actually
5651    // qualified __strong.
5652    Qualifiers::GC GC_L = LQuals.getObjCGCAttr();
5653    Qualifiers::GC GC_R = RQuals.getObjCGCAttr();
5654    assert((GC_L != GC_R) && "unequal qualifier sets had only equal elements");
5655
5656    if (GC_L == Qualifiers::Weak || GC_R == Qualifiers::Weak)
5657      return QualType();
5658
5659    if (GC_L == Qualifiers::Strong && RHSCan->isObjCObjectPointerType()) {
5660      return mergeTypes(LHS, getObjCGCQualType(RHS, Qualifiers::Strong));
5661    }
5662    if (GC_R == Qualifiers::Strong && LHSCan->isObjCObjectPointerType()) {
5663      return mergeTypes(getObjCGCQualType(LHS, Qualifiers::Strong), RHS);
5664    }
5665    return QualType();
5666  }
5667
5668  // Okay, qualifiers are equal.
5669
5670  Type::TypeClass LHSClass = LHSCan->getTypeClass();
5671  Type::TypeClass RHSClass = RHSCan->getTypeClass();
5672
5673  // We want to consider the two function types to be the same for these
5674  // comparisons, just force one to the other.
5675  if (LHSClass == Type::FunctionProto) LHSClass = Type::FunctionNoProto;
5676  if (RHSClass == Type::FunctionProto) RHSClass = Type::FunctionNoProto;
5677
5678  // Same as above for arrays
5679  if (LHSClass == Type::VariableArray || LHSClass == Type::IncompleteArray)
5680    LHSClass = Type::ConstantArray;
5681  if (RHSClass == Type::VariableArray || RHSClass == Type::IncompleteArray)
5682    RHSClass = Type::ConstantArray;
5683
5684  // ObjCInterfaces are just specialized ObjCObjects.
5685  if (LHSClass == Type::ObjCInterface) LHSClass = Type::ObjCObject;
5686  if (RHSClass == Type::ObjCInterface) RHSClass = Type::ObjCObject;
5687
5688  // Canonicalize ExtVector -> Vector.
5689  if (LHSClass == Type::ExtVector) LHSClass = Type::Vector;
5690  if (RHSClass == Type::ExtVector) RHSClass = Type::Vector;
5691
5692  // If the canonical type classes don't match.
5693  if (LHSClass != RHSClass) {
5694    // C99 6.7.2.2p4: Each enumerated type shall be compatible with char,
5695    // a signed integer type, or an unsigned integer type.
5696    // Compatibility is based on the underlying type, not the promotion
5697    // type.
5698    if (const EnumType* ETy = LHS->getAs<EnumType>()) {
5699      if (ETy->getDecl()->getIntegerType() == RHSCan.getUnqualifiedType())
5700        return RHS;
5701    }
5702    if (const EnumType* ETy = RHS->getAs<EnumType>()) {
5703      if (ETy->getDecl()->getIntegerType() == LHSCan.getUnqualifiedType())
5704        return LHS;
5705    }
5706
5707    return QualType();
5708  }
5709
5710  // The canonical type classes match.
5711  switch (LHSClass) {
5712#define TYPE(Class, Base)
5713#define ABSTRACT_TYPE(Class, Base)
5714#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
5715#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
5716#define DEPENDENT_TYPE(Class, Base) case Type::Class:
5717#include "clang/AST/TypeNodes.def"
5718    assert(false && "Non-canonical and dependent types shouldn't get here");
5719    return QualType();
5720
5721  case Type::LValueReference:
5722  case Type::RValueReference:
5723  case Type::MemberPointer:
5724    assert(false && "C++ should never be in mergeTypes");
5725    return QualType();
5726
5727  case Type::ObjCInterface:
5728  case Type::IncompleteArray:
5729  case Type::VariableArray:
5730  case Type::FunctionProto:
5731  case Type::ExtVector:
5732    assert(false && "Types are eliminated above");
5733    return QualType();
5734
5735  case Type::Pointer:
5736  {
5737    // Merge two pointer types, while trying to preserve typedef info
5738    QualType LHSPointee = LHS->getAs<PointerType>()->getPointeeType();
5739    QualType RHSPointee = RHS->getAs<PointerType>()->getPointeeType();
5740    if (Unqualified) {
5741      LHSPointee = LHSPointee.getUnqualifiedType();
5742      RHSPointee = RHSPointee.getUnqualifiedType();
5743    }
5744    QualType ResultType = mergeTypes(LHSPointee, RHSPointee, false,
5745                                     Unqualified);
5746    if (ResultType.isNull()) return QualType();
5747    if (getCanonicalType(LHSPointee) == getCanonicalType(ResultType))
5748      return LHS;
5749    if (getCanonicalType(RHSPointee) == getCanonicalType(ResultType))
5750      return RHS;
5751    return getPointerType(ResultType);
5752  }
5753  case Type::BlockPointer:
5754  {
5755    // Merge two block pointer types, while trying to preserve typedef info
5756    QualType LHSPointee = LHS->getAs<BlockPointerType>()->getPointeeType();
5757    QualType RHSPointee = RHS->getAs<BlockPointerType>()->getPointeeType();
5758    if (Unqualified) {
5759      LHSPointee = LHSPointee.getUnqualifiedType();
5760      RHSPointee = RHSPointee.getUnqualifiedType();
5761    }
5762    QualType ResultType = mergeTypes(LHSPointee, RHSPointee, OfBlockPointer,
5763                                     Unqualified);
5764    if (ResultType.isNull()) return QualType();
5765    if (getCanonicalType(LHSPointee) == getCanonicalType(ResultType))
5766      return LHS;
5767    if (getCanonicalType(RHSPointee) == getCanonicalType(ResultType))
5768      return RHS;
5769    return getBlockPointerType(ResultType);
5770  }
5771  case Type::ConstantArray:
5772  {
5773    const ConstantArrayType* LCAT = getAsConstantArrayType(LHS);
5774    const ConstantArrayType* RCAT = getAsConstantArrayType(RHS);
5775    if (LCAT && RCAT && RCAT->getSize() != LCAT->getSize())
5776      return QualType();
5777
5778    QualType LHSElem = getAsArrayType(LHS)->getElementType();
5779    QualType RHSElem = getAsArrayType(RHS)->getElementType();
5780    if (Unqualified) {
5781      LHSElem = LHSElem.getUnqualifiedType();
5782      RHSElem = RHSElem.getUnqualifiedType();
5783    }
5784
5785    QualType ResultType = mergeTypes(LHSElem, RHSElem, false, Unqualified);
5786    if (ResultType.isNull()) return QualType();
5787    if (LCAT && getCanonicalType(LHSElem) == getCanonicalType(ResultType))
5788      return LHS;
5789    if (RCAT && getCanonicalType(RHSElem) == getCanonicalType(ResultType))
5790      return RHS;
5791    if (LCAT) return getConstantArrayType(ResultType, LCAT->getSize(),
5792                                          ArrayType::ArraySizeModifier(), 0);
5793    if (RCAT) return getConstantArrayType(ResultType, RCAT->getSize(),
5794                                          ArrayType::ArraySizeModifier(), 0);
5795    const VariableArrayType* LVAT = getAsVariableArrayType(LHS);
5796    const VariableArrayType* RVAT = getAsVariableArrayType(RHS);
5797    if (LVAT && getCanonicalType(LHSElem) == getCanonicalType(ResultType))
5798      return LHS;
5799    if (RVAT && getCanonicalType(RHSElem) == getCanonicalType(ResultType))
5800      return RHS;
5801    if (LVAT) {
5802      // FIXME: This isn't correct! But tricky to implement because
5803      // the array's size has to be the size of LHS, but the type
5804      // has to be different.
5805      return LHS;
5806    }
5807    if (RVAT) {
5808      // FIXME: This isn't correct! But tricky to implement because
5809      // the array's size has to be the size of RHS, but the type
5810      // has to be different.
5811      return RHS;
5812    }
5813    if (getCanonicalType(LHSElem) == getCanonicalType(ResultType)) return LHS;
5814    if (getCanonicalType(RHSElem) == getCanonicalType(ResultType)) return RHS;
5815    return getIncompleteArrayType(ResultType,
5816                                  ArrayType::ArraySizeModifier(), 0);
5817  }
5818  case Type::FunctionNoProto:
5819    return mergeFunctionTypes(LHS, RHS, OfBlockPointer, Unqualified);
5820  case Type::Record:
5821  case Type::Enum:
5822    return QualType();
5823  case Type::Builtin:
5824    // Only exactly equal builtin types are compatible, which is tested above.
5825    return QualType();
5826  case Type::Complex:
5827    // Distinct complex types are incompatible.
5828    return QualType();
5829  case Type::Vector:
5830    // FIXME: The merged type should be an ExtVector!
5831    if (areCompatVectorTypes(LHSCan->getAs<VectorType>(),
5832                             RHSCan->getAs<VectorType>()))
5833      return LHS;
5834    return QualType();
5835  case Type::ObjCObject: {
5836    // Check if the types are assignment compatible.
5837    // FIXME: This should be type compatibility, e.g. whether
5838    // "LHS x; RHS x;" at global scope is legal.
5839    const ObjCObjectType* LHSIface = LHS->getAs<ObjCObjectType>();
5840    const ObjCObjectType* RHSIface = RHS->getAs<ObjCObjectType>();
5841    if (canAssignObjCInterfaces(LHSIface, RHSIface))
5842      return LHS;
5843
5844    return QualType();
5845  }
5846  case Type::ObjCObjectPointer: {
5847    if (OfBlockPointer) {
5848      if (canAssignObjCInterfacesInBlockPointer(
5849                                          LHS->getAs<ObjCObjectPointerType>(),
5850                                          RHS->getAs<ObjCObjectPointerType>(),
5851                                          BlockReturnType))
5852      return LHS;
5853      return QualType();
5854    }
5855    if (canAssignObjCInterfaces(LHS->getAs<ObjCObjectPointerType>(),
5856                                RHS->getAs<ObjCObjectPointerType>()))
5857      return LHS;
5858
5859    return QualType();
5860    }
5861  }
5862
5863  return QualType();
5864}
5865
5866/// mergeObjCGCQualifiers - This routine merges ObjC's GC attribute of 'LHS' and
5867/// 'RHS' attributes and returns the merged version; including for function
5868/// return types.
5869QualType ASTContext::mergeObjCGCQualifiers(QualType LHS, QualType RHS) {
5870  QualType LHSCan = getCanonicalType(LHS),
5871  RHSCan = getCanonicalType(RHS);
5872  // If two types are identical, they are compatible.
5873  if (LHSCan == RHSCan)
5874    return LHS;
5875  if (RHSCan->isFunctionType()) {
5876    if (!LHSCan->isFunctionType())
5877      return QualType();
5878    QualType OldReturnType =
5879      cast<FunctionType>(RHSCan.getTypePtr())->getResultType();
5880    QualType NewReturnType =
5881      cast<FunctionType>(LHSCan.getTypePtr())->getResultType();
5882    QualType ResReturnType =
5883      mergeObjCGCQualifiers(NewReturnType, OldReturnType);
5884    if (ResReturnType.isNull())
5885      return QualType();
5886    if (ResReturnType == NewReturnType || ResReturnType == OldReturnType) {
5887      // id foo(); ... __strong id foo(); or: __strong id foo(); ... id foo();
5888      // In either case, use OldReturnType to build the new function type.
5889      const FunctionType *F = LHS->getAs<FunctionType>();
5890      if (const FunctionProtoType *FPT = cast<FunctionProtoType>(F)) {
5891        FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
5892        EPI.ExtInfo = getFunctionExtInfo(LHS);
5893        QualType ResultType
5894          = getFunctionType(OldReturnType, FPT->arg_type_begin(),
5895                            FPT->getNumArgs(), EPI);
5896        return ResultType;
5897      }
5898    }
5899    return QualType();
5900  }
5901
5902  // If the qualifiers are different, the types can still be merged.
5903  Qualifiers LQuals = LHSCan.getLocalQualifiers();
5904  Qualifiers RQuals = RHSCan.getLocalQualifiers();
5905  if (LQuals != RQuals) {
5906    // If any of these qualifiers are different, we have a type mismatch.
5907    if (LQuals.getCVRQualifiers() != RQuals.getCVRQualifiers() ||
5908        LQuals.getAddressSpace() != RQuals.getAddressSpace())
5909      return QualType();
5910
5911    // Exactly one GC qualifier difference is allowed: __strong is
5912    // okay if the other type has no GC qualifier but is an Objective
5913    // C object pointer (i.e. implicitly strong by default).  We fix
5914    // this by pretending that the unqualified type was actually
5915    // qualified __strong.
5916    Qualifiers::GC GC_L = LQuals.getObjCGCAttr();
5917    Qualifiers::GC GC_R = RQuals.getObjCGCAttr();
5918    assert((GC_L != GC_R) && "unequal qualifier sets had only equal elements");
5919
5920    if (GC_L == Qualifiers::Weak || GC_R == Qualifiers::Weak)
5921      return QualType();
5922
5923    if (GC_L == Qualifiers::Strong)
5924      return LHS;
5925    if (GC_R == Qualifiers::Strong)
5926      return RHS;
5927    return QualType();
5928  }
5929
5930  if (LHSCan->isObjCObjectPointerType() && RHSCan->isObjCObjectPointerType()) {
5931    QualType LHSBaseQT = LHS->getAs<ObjCObjectPointerType>()->getPointeeType();
5932    QualType RHSBaseQT = RHS->getAs<ObjCObjectPointerType>()->getPointeeType();
5933    QualType ResQT = mergeObjCGCQualifiers(LHSBaseQT, RHSBaseQT);
5934    if (ResQT == LHSBaseQT)
5935      return LHS;
5936    if (ResQT == RHSBaseQT)
5937      return RHS;
5938  }
5939  return QualType();
5940}
5941
5942//===----------------------------------------------------------------------===//
5943//                         Integer Predicates
5944//===----------------------------------------------------------------------===//
5945
5946unsigned ASTContext::getIntWidth(QualType T) const {
5947  if (const EnumType *ET = dyn_cast<EnumType>(T))
5948    T = ET->getDecl()->getIntegerType();
5949  if (T->isBooleanType())
5950    return 1;
5951  // For builtin types, just use the standard type sizing method
5952  return (unsigned)getTypeSize(T);
5953}
5954
5955QualType ASTContext::getCorrespondingUnsignedType(QualType T) {
5956  assert(T->hasSignedIntegerRepresentation() && "Unexpected type");
5957
5958  // Turn <4 x signed int> -> <4 x unsigned int>
5959  if (const VectorType *VTy = T->getAs<VectorType>())
5960    return getVectorType(getCorrespondingUnsignedType(VTy->getElementType()),
5961                         VTy->getNumElements(), VTy->getVectorKind());
5962
5963  // For enums, we return the unsigned version of the base type.
5964  if (const EnumType *ETy = T->getAs<EnumType>())
5965    T = ETy->getDecl()->getIntegerType();
5966
5967  const BuiltinType *BTy = T->getAs<BuiltinType>();
5968  assert(BTy && "Unexpected signed integer type");
5969  switch (BTy->getKind()) {
5970  case BuiltinType::Char_S:
5971  case BuiltinType::SChar:
5972    return UnsignedCharTy;
5973  case BuiltinType::Short:
5974    return UnsignedShortTy;
5975  case BuiltinType::Int:
5976    return UnsignedIntTy;
5977  case BuiltinType::Long:
5978    return UnsignedLongTy;
5979  case BuiltinType::LongLong:
5980    return UnsignedLongLongTy;
5981  case BuiltinType::Int128:
5982    return UnsignedInt128Ty;
5983  default:
5984    assert(0 && "Unexpected signed integer type");
5985    return QualType();
5986  }
5987}
5988
5989ASTMutationListener::~ASTMutationListener() { }
5990
5991
5992//===----------------------------------------------------------------------===//
5993//                          Builtin Type Computation
5994//===----------------------------------------------------------------------===//
5995
5996/// DecodeTypeFromStr - This decodes one type descriptor from Str, advancing the
5997/// pointer over the consumed characters.  This returns the resultant type.  If
5998/// AllowTypeModifiers is false then modifier like * are not parsed, just basic
5999/// types.  This allows "v2i*" to be parsed as a pointer to a v2i instead of
6000/// a vector of "i*".
6001///
6002/// RequiresICE is filled in on return to indicate whether the value is required
6003/// to be an Integer Constant Expression.
6004static QualType DecodeTypeFromStr(const char *&Str, const ASTContext &Context,
6005                                  ASTContext::GetBuiltinTypeError &Error,
6006                                  bool &RequiresICE,
6007                                  bool AllowTypeModifiers) {
6008  // Modifiers.
6009  int HowLong = 0;
6010  bool Signed = false, Unsigned = false;
6011  RequiresICE = false;
6012
6013  // Read the prefixed modifiers first.
6014  bool Done = false;
6015  while (!Done) {
6016    switch (*Str++) {
6017    default: Done = true; --Str; break;
6018    case 'I':
6019      RequiresICE = true;
6020      break;
6021    case 'S':
6022      assert(!Unsigned && "Can't use both 'S' and 'U' modifiers!");
6023      assert(!Signed && "Can't use 'S' modifier multiple times!");
6024      Signed = true;
6025      break;
6026    case 'U':
6027      assert(!Signed && "Can't use both 'S' and 'U' modifiers!");
6028      assert(!Unsigned && "Can't use 'S' modifier multiple times!");
6029      Unsigned = true;
6030      break;
6031    case 'L':
6032      assert(HowLong <= 2 && "Can't have LLLL modifier");
6033      ++HowLong;
6034      break;
6035    }
6036  }
6037
6038  QualType Type;
6039
6040  // Read the base type.
6041  switch (*Str++) {
6042  default: assert(0 && "Unknown builtin type letter!");
6043  case 'v':
6044    assert(HowLong == 0 && !Signed && !Unsigned &&
6045           "Bad modifiers used with 'v'!");
6046    Type = Context.VoidTy;
6047    break;
6048  case 'f':
6049    assert(HowLong == 0 && !Signed && !Unsigned &&
6050           "Bad modifiers used with 'f'!");
6051    Type = Context.FloatTy;
6052    break;
6053  case 'd':
6054    assert(HowLong < 2 && !Signed && !Unsigned &&
6055           "Bad modifiers used with 'd'!");
6056    if (HowLong)
6057      Type = Context.LongDoubleTy;
6058    else
6059      Type = Context.DoubleTy;
6060    break;
6061  case 's':
6062    assert(HowLong == 0 && "Bad modifiers used with 's'!");
6063    if (Unsigned)
6064      Type = Context.UnsignedShortTy;
6065    else
6066      Type = Context.ShortTy;
6067    break;
6068  case 'i':
6069    if (HowLong == 3)
6070      Type = Unsigned ? Context.UnsignedInt128Ty : Context.Int128Ty;
6071    else if (HowLong == 2)
6072      Type = Unsigned ? Context.UnsignedLongLongTy : Context.LongLongTy;
6073    else if (HowLong == 1)
6074      Type = Unsigned ? Context.UnsignedLongTy : Context.LongTy;
6075    else
6076      Type = Unsigned ? Context.UnsignedIntTy : Context.IntTy;
6077    break;
6078  case 'c':
6079    assert(HowLong == 0 && "Bad modifiers used with 'c'!");
6080    if (Signed)
6081      Type = Context.SignedCharTy;
6082    else if (Unsigned)
6083      Type = Context.UnsignedCharTy;
6084    else
6085      Type = Context.CharTy;
6086    break;
6087  case 'b': // boolean
6088    assert(HowLong == 0 && !Signed && !Unsigned && "Bad modifiers for 'b'!");
6089    Type = Context.BoolTy;
6090    break;
6091  case 'z':  // size_t.
6092    assert(HowLong == 0 && !Signed && !Unsigned && "Bad modifiers for 'z'!");
6093    Type = Context.getSizeType();
6094    break;
6095  case 'F':
6096    Type = Context.getCFConstantStringType();
6097    break;
6098  case 'G':
6099    Type = Context.getObjCIdType();
6100    break;
6101  case 'H':
6102    Type = Context.getObjCSelType();
6103    break;
6104  case 'a':
6105    Type = Context.getBuiltinVaListType();
6106    assert(!Type.isNull() && "builtin va list type not initialized!");
6107    break;
6108  case 'A':
6109    // This is a "reference" to a va_list; however, what exactly
6110    // this means depends on how va_list is defined. There are two
6111    // different kinds of va_list: ones passed by value, and ones
6112    // passed by reference.  An example of a by-value va_list is
6113    // x86, where va_list is a char*. An example of by-ref va_list
6114    // is x86-64, where va_list is a __va_list_tag[1]. For x86,
6115    // we want this argument to be a char*&; for x86-64, we want
6116    // it to be a __va_list_tag*.
6117    Type = Context.getBuiltinVaListType();
6118    assert(!Type.isNull() && "builtin va list type not initialized!");
6119    if (Type->isArrayType())
6120      Type = Context.getArrayDecayedType(Type);
6121    else
6122      Type = Context.getLValueReferenceType(Type);
6123    break;
6124  case 'V': {
6125    char *End;
6126    unsigned NumElements = strtoul(Str, &End, 10);
6127    assert(End != Str && "Missing vector size");
6128    Str = End;
6129
6130    QualType ElementType = DecodeTypeFromStr(Str, Context, Error,
6131                                             RequiresICE, false);
6132    assert(!RequiresICE && "Can't require vector ICE");
6133
6134    // TODO: No way to make AltiVec vectors in builtins yet.
6135    Type = Context.getVectorType(ElementType, NumElements,
6136                                 VectorType::GenericVector);
6137    break;
6138  }
6139  case 'X': {
6140    QualType ElementType = DecodeTypeFromStr(Str, Context, Error, RequiresICE,
6141                                             false);
6142    assert(!RequiresICE && "Can't require complex ICE");
6143    Type = Context.getComplexType(ElementType);
6144    break;
6145  }
6146  case 'P':
6147    Type = Context.getFILEType();
6148    if (Type.isNull()) {
6149      Error = ASTContext::GE_Missing_stdio;
6150      return QualType();
6151    }
6152    break;
6153  case 'J':
6154    if (Signed)
6155      Type = Context.getsigjmp_bufType();
6156    else
6157      Type = Context.getjmp_bufType();
6158
6159    if (Type.isNull()) {
6160      Error = ASTContext::GE_Missing_setjmp;
6161      return QualType();
6162    }
6163    break;
6164  }
6165
6166  // If there are modifiers and if we're allowed to parse them, go for it.
6167  Done = !AllowTypeModifiers;
6168  while (!Done) {
6169    switch (char c = *Str++) {
6170    default: Done = true; --Str; break;
6171    case '*':
6172    case '&': {
6173      // Both pointers and references can have their pointee types
6174      // qualified with an address space.
6175      char *End;
6176      unsigned AddrSpace = strtoul(Str, &End, 10);
6177      if (End != Str && AddrSpace != 0) {
6178        Type = Context.getAddrSpaceQualType(Type, AddrSpace);
6179        Str = End;
6180      }
6181      if (c == '*')
6182        Type = Context.getPointerType(Type);
6183      else
6184        Type = Context.getLValueReferenceType(Type);
6185      break;
6186    }
6187    // FIXME: There's no way to have a built-in with an rvalue ref arg.
6188    case 'C':
6189      Type = Type.withConst();
6190      break;
6191    case 'D':
6192      Type = Context.getVolatileType(Type);
6193      break;
6194    }
6195  }
6196
6197  assert((!RequiresICE || Type->isIntegralOrEnumerationType()) &&
6198         "Integer constant 'I' type must be an integer");
6199
6200  return Type;
6201}
6202
6203/// GetBuiltinType - Return the type for the specified builtin.
6204QualType ASTContext::GetBuiltinType(unsigned Id,
6205                                    GetBuiltinTypeError &Error,
6206                                    unsigned *IntegerConstantArgs) const {
6207  const char *TypeStr = BuiltinInfo.GetTypeString(Id);
6208
6209  SmallVector<QualType, 8> ArgTypes;
6210
6211  bool RequiresICE = false;
6212  Error = GE_None;
6213  QualType ResType = DecodeTypeFromStr(TypeStr, *this, Error,
6214                                       RequiresICE, true);
6215  if (Error != GE_None)
6216    return QualType();
6217
6218  assert(!RequiresICE && "Result of intrinsic cannot be required to be an ICE");
6219
6220  while (TypeStr[0] && TypeStr[0] != '.') {
6221    QualType Ty = DecodeTypeFromStr(TypeStr, *this, Error, RequiresICE, true);
6222    if (Error != GE_None)
6223      return QualType();
6224
6225    // If this argument is required to be an IntegerConstantExpression and the
6226    // caller cares, fill in the bitmask we return.
6227    if (RequiresICE && IntegerConstantArgs)
6228      *IntegerConstantArgs |= 1 << ArgTypes.size();
6229
6230    // Do array -> pointer decay.  The builtin should use the decayed type.
6231    if (Ty->isArrayType())
6232      Ty = getArrayDecayedType(Ty);
6233
6234    ArgTypes.push_back(Ty);
6235  }
6236
6237  assert((TypeStr[0] != '.' || TypeStr[1] == 0) &&
6238         "'.' should only occur at end of builtin type list!");
6239
6240  FunctionType::ExtInfo EI;
6241  if (BuiltinInfo.isNoReturn(Id)) EI = EI.withNoReturn(true);
6242
6243  bool Variadic = (TypeStr[0] == '.');
6244
6245  // We really shouldn't be making a no-proto type here, especially in C++.
6246  if (ArgTypes.empty() && Variadic)
6247    return getFunctionNoProtoType(ResType, EI);
6248
6249  FunctionProtoType::ExtProtoInfo EPI;
6250  EPI.ExtInfo = EI;
6251  EPI.Variadic = Variadic;
6252
6253  return getFunctionType(ResType, ArgTypes.data(), ArgTypes.size(), EPI);
6254}
6255
6256GVALinkage ASTContext::GetGVALinkageForFunction(const FunctionDecl *FD) {
6257  GVALinkage External = GVA_StrongExternal;
6258
6259  Linkage L = FD->getLinkage();
6260  switch (L) {
6261  case NoLinkage:
6262  case InternalLinkage:
6263  case UniqueExternalLinkage:
6264    return GVA_Internal;
6265
6266  case ExternalLinkage:
6267    switch (FD->getTemplateSpecializationKind()) {
6268    case TSK_Undeclared:
6269    case TSK_ExplicitSpecialization:
6270      External = GVA_StrongExternal;
6271      break;
6272
6273    case TSK_ExplicitInstantiationDefinition:
6274      return GVA_ExplicitTemplateInstantiation;
6275
6276    case TSK_ExplicitInstantiationDeclaration:
6277    case TSK_ImplicitInstantiation:
6278      External = GVA_TemplateInstantiation;
6279      break;
6280    }
6281  }
6282
6283  if (!FD->isInlined())
6284    return External;
6285
6286  if (!getLangOptions().CPlusPlus || FD->hasAttr<GNUInlineAttr>()) {
6287    // GNU or C99 inline semantics. Determine whether this symbol should be
6288    // externally visible.
6289    if (FD->isInlineDefinitionExternallyVisible())
6290      return External;
6291
6292    // C99 inline semantics, where the symbol is not externally visible.
6293    return GVA_C99Inline;
6294  }
6295
6296  // C++0x [temp.explicit]p9:
6297  //   [ Note: The intent is that an inline function that is the subject of
6298  //   an explicit instantiation declaration will still be implicitly
6299  //   instantiated when used so that the body can be considered for
6300  //   inlining, but that no out-of-line copy of the inline function would be
6301  //   generated in the translation unit. -- end note ]
6302  if (FD->getTemplateSpecializationKind()
6303                                       == TSK_ExplicitInstantiationDeclaration)
6304    return GVA_C99Inline;
6305
6306  return GVA_CXXInline;
6307}
6308
6309GVALinkage ASTContext::GetGVALinkageForVariable(const VarDecl *VD) {
6310  // If this is a static data member, compute the kind of template
6311  // specialization. Otherwise, this variable is not part of a
6312  // template.
6313  TemplateSpecializationKind TSK = TSK_Undeclared;
6314  if (VD->isStaticDataMember())
6315    TSK = VD->getTemplateSpecializationKind();
6316
6317  Linkage L = VD->getLinkage();
6318  if (L == ExternalLinkage && getLangOptions().CPlusPlus &&
6319      VD->getType()->getLinkage() == UniqueExternalLinkage)
6320    L = UniqueExternalLinkage;
6321
6322  switch (L) {
6323  case NoLinkage:
6324  case InternalLinkage:
6325  case UniqueExternalLinkage:
6326    return GVA_Internal;
6327
6328  case ExternalLinkage:
6329    switch (TSK) {
6330    case TSK_Undeclared:
6331    case TSK_ExplicitSpecialization:
6332      return GVA_StrongExternal;
6333
6334    case TSK_ExplicitInstantiationDeclaration:
6335      llvm_unreachable("Variable should not be instantiated");
6336      // Fall through to treat this like any other instantiation.
6337
6338    case TSK_ExplicitInstantiationDefinition:
6339      return GVA_ExplicitTemplateInstantiation;
6340
6341    case TSK_ImplicitInstantiation:
6342      return GVA_TemplateInstantiation;
6343    }
6344  }
6345
6346  return GVA_StrongExternal;
6347}
6348
6349bool ASTContext::DeclMustBeEmitted(const Decl *D) {
6350  if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
6351    if (!VD->isFileVarDecl())
6352      return false;
6353  } else if (!isa<FunctionDecl>(D))
6354    return false;
6355
6356  // Weak references don't produce any output by themselves.
6357  if (D->hasAttr<WeakRefAttr>())
6358    return false;
6359
6360  // Aliases and used decls are required.
6361  if (D->hasAttr<AliasAttr>() || D->hasAttr<UsedAttr>())
6362    return true;
6363
6364  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6365    // Forward declarations aren't required.
6366    if (!FD->doesThisDeclarationHaveABody())
6367      return FD->doesDeclarationForceExternallyVisibleDefinition();
6368
6369    // Constructors and destructors are required.
6370    if (FD->hasAttr<ConstructorAttr>() || FD->hasAttr<DestructorAttr>())
6371      return true;
6372
6373    // The key function for a class is required.
6374    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
6375      const CXXRecordDecl *RD = MD->getParent();
6376      if (MD->isOutOfLine() && RD->isDynamicClass()) {
6377        const CXXMethodDecl *KeyFunc = getKeyFunction(RD);
6378        if (KeyFunc && KeyFunc->getCanonicalDecl() == MD->getCanonicalDecl())
6379          return true;
6380      }
6381    }
6382
6383    GVALinkage Linkage = GetGVALinkageForFunction(FD);
6384
6385    // static, static inline, always_inline, and extern inline functions can
6386    // always be deferred.  Normal inline functions can be deferred in C99/C++.
6387    // Implicit template instantiations can also be deferred in C++.
6388    if (Linkage == GVA_Internal  || Linkage == GVA_C99Inline ||
6389        Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation)
6390      return false;
6391    return true;
6392  }
6393
6394  const VarDecl *VD = cast<VarDecl>(D);
6395  assert(VD->isFileVarDecl() && "Expected file scoped var");
6396
6397  if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly)
6398    return false;
6399
6400  // Structs that have non-trivial constructors or destructors are required.
6401
6402  // FIXME: Handle references.
6403  // FIXME: Be more selective about which constructors we care about.
6404  if (const RecordType *RT = VD->getType()->getAs<RecordType>()) {
6405    if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
6406      if (RD->hasDefinition() && !(RD->hasTrivialDefaultConstructor() &&
6407                                   RD->hasTrivialCopyConstructor() &&
6408                                   RD->hasTrivialMoveConstructor() &&
6409                                   RD->hasTrivialDestructor()))
6410        return true;
6411    }
6412  }
6413
6414  GVALinkage L = GetGVALinkageForVariable(VD);
6415  if (L == GVA_Internal || L == GVA_TemplateInstantiation) {
6416    if (!(VD->getInit() && VD->getInit()->HasSideEffects(*this)))
6417      return false;
6418  }
6419
6420  return true;
6421}
6422
6423CallingConv ASTContext::getDefaultMethodCallConv() {
6424  // Pass through to the C++ ABI object
6425  return ABI->getDefaultMethodCallConv();
6426}
6427
6428bool ASTContext::isNearlyEmpty(const CXXRecordDecl *RD) const {
6429  // Pass through to the C++ ABI object
6430  return ABI->isNearlyEmpty(RD);
6431}
6432
6433MangleContext *ASTContext::createMangleContext() {
6434  switch (Target.getCXXABI()) {
6435  case CXXABI_ARM:
6436  case CXXABI_Itanium:
6437    return createItaniumMangleContext(*this, getDiagnostics());
6438  case CXXABI_Microsoft:
6439    return createMicrosoftMangleContext(*this, getDiagnostics());
6440  }
6441  assert(0 && "Unsupported ABI");
6442  return 0;
6443}
6444
6445CXXABI::~CXXABI() {}
6446
6447size_t ASTContext::getSideTableAllocatedMemory() const {
6448  return ASTRecordLayouts.getMemorySize()
6449    + llvm::capacity_in_bytes(ObjCLayouts)
6450    + llvm::capacity_in_bytes(KeyFunctions)
6451    + llvm::capacity_in_bytes(ObjCImpls)
6452    + llvm::capacity_in_bytes(BlockVarCopyInits)
6453    + llvm::capacity_in_bytes(DeclAttrs)
6454    + llvm::capacity_in_bytes(InstantiatedFromStaticDataMember)
6455    + llvm::capacity_in_bytes(InstantiatedFromUsingDecl)
6456    + llvm::capacity_in_bytes(InstantiatedFromUsingShadowDecl)
6457    + llvm::capacity_in_bytes(InstantiatedFromUnnamedFieldDecl)
6458    + llvm::capacity_in_bytes(OverriddenMethods)
6459    + llvm::capacity_in_bytes(Types)
6460    + llvm::capacity_in_bytes(VariableArrayTypes)
6461    + llvm::capacity_in_bytes(ClassScopeSpecilizationPattern);
6462}
6463