ASTContext.cpp revision 0c01d18094100db92d38daa923c95661512db203 
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/ExternalASTSource.h"
22#include "clang/AST/RecordLayout.h"
23#include "clang/Basic/Builtins.h"
24#include "clang/Basic/SourceManager.h"
25#include "clang/Basic/TargetInfo.h"
26#include "llvm/ADT/SmallString.h"
27#include "llvm/ADT/StringExtras.h"
28#include "llvm/Support/MathExtras.h"
29#include "llvm/Support/raw_ostream.h"
30#include "RecordLayoutBuilder.h"
31
32using namespace clang;
33
34enum FloatingRank {
35  FloatRank, DoubleRank, LongDoubleRank
36};
37
38ASTContext::ASTContext(const LangOptions& LOpts, SourceManager &SM,
39                       const TargetInfo &t,
40                       IdentifierTable &idents, SelectorTable &sels,
41                       Builtin::Context &builtins,
42                       bool FreeMem, unsigned size_reserve) :
43  GlobalNestedNameSpecifier(0), CFConstantStringTypeDecl(0),
44  ObjCFastEnumerationStateTypeDecl(0), FILEDecl(0), jmp_bufDecl(0),
45  sigjmp_bufDecl(0), BlockDescriptorType(0), BlockDescriptorExtendedType(0),
46  SourceMgr(SM), LangOpts(LOpts), FreeMemory(FreeMem), Target(t),
47  Idents(idents), Selectors(sels),
48  BuiltinInfo(builtins), ExternalSource(0), PrintingPolicy(LOpts),
49  LastSDM(0, 0) {
50  ObjCIdRedefinitionType = QualType();
51  ObjCClassRedefinitionType = QualType();
52  ObjCSelRedefinitionType = QualType();
53  if (size_reserve > 0) Types.reserve(size_reserve);
54  TUDecl = TranslationUnitDecl::Create(*this);
55  InitBuiltinTypes();
56}
57
58ASTContext::~ASTContext() {
59  // Release the DenseMaps associated with DeclContext objects.
60  // FIXME: Is this the ideal solution?
61  ReleaseDeclContextMaps();
62
63  // Release all of the memory associated with overridden C++ methods.
64  for (llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector>::iterator
65         OM = OverriddenMethods.begin(), OMEnd = OverriddenMethods.end();
66       OM != OMEnd; ++OM)
67    OM->second.Destroy();
68
69  if (FreeMemory) {
70    // Deallocate all the types.
71    while (!Types.empty()) {
72      Types.back()->Destroy(*this);
73      Types.pop_back();
74    }
75
76    for (llvm::FoldingSet<ExtQuals>::iterator
77         I = ExtQualNodes.begin(), E = ExtQualNodes.end(); I != E; ) {
78      // Increment in loop to prevent using deallocated memory.
79      Deallocate(&*I++);
80    }
81
82    for (llvm::DenseMap<const RecordDecl*, const ASTRecordLayout*>::iterator
83         I = ASTRecordLayouts.begin(), E = ASTRecordLayouts.end(); I != E; ) {
84      // Increment in loop to prevent using deallocated memory.
85      if (ASTRecordLayout *R = const_cast<ASTRecordLayout*>((I++)->second))
86        R->Destroy(*this);
87    }
88
89    for (llvm::DenseMap<const ObjCContainerDecl*,
90         const ASTRecordLayout*>::iterator
91         I = ObjCLayouts.begin(), E = ObjCLayouts.end(); I != E; ) {
92      // Increment in loop to prevent using deallocated memory.
93      if (ASTRecordLayout *R = const_cast<ASTRecordLayout*>((I++)->second))
94        R->Destroy(*this);
95    }
96  }
97
98  // Destroy nested-name-specifiers.
99  for (llvm::FoldingSet<NestedNameSpecifier>::iterator
100         NNS = NestedNameSpecifiers.begin(),
101         NNSEnd = NestedNameSpecifiers.end();
102       NNS != NNSEnd; ) {
103    // Increment in loop to prevent using deallocated memory.
104    (*NNS++).Destroy(*this);
105  }
106
107  if (GlobalNestedNameSpecifier)
108    GlobalNestedNameSpecifier->Destroy(*this);
109
110  TUDecl->Destroy(*this);
111}
112
113void
114ASTContext::setExternalSource(llvm::OwningPtr<ExternalASTSource> &Source) {
115  ExternalSource.reset(Source.take());
116}
117
118void ASTContext::PrintStats() const {
119  fprintf(stderr, "*** AST Context Stats:\n");
120  fprintf(stderr, "  %d types total.\n", (int)Types.size());
121
122  unsigned counts[] = {
123#define TYPE(Name, Parent) 0,
124#define ABSTRACT_TYPE(Name, Parent)
125#include "clang/AST/TypeNodes.def"
126    0 // Extra
127  };
128
129  for (unsigned i = 0, e = Types.size(); i != e; ++i) {
130    Type *T = Types[i];
131    counts[(unsigned)T->getTypeClass()]++;
132  }
133
134  unsigned Idx = 0;
135  unsigned TotalBytes = 0;
136#define TYPE(Name, Parent)                                              \
137  if (counts[Idx])                                                      \
138    fprintf(stderr, "    %d %s types\n", (int)counts[Idx], #Name);      \
139  TotalBytes += counts[Idx] * sizeof(Name##Type);                       \
140  ++Idx;
141#define ABSTRACT_TYPE(Name, Parent)
142#include "clang/AST/TypeNodes.def"
143
144  fprintf(stderr, "Total bytes = %d\n", int(TotalBytes));
145
146  if (ExternalSource.get()) {
147    fprintf(stderr, "\n");
148    ExternalSource->PrintStats();
149  }
150}
151
152
153void ASTContext::InitBuiltinType(CanQualType &R, BuiltinType::Kind K) {
154  BuiltinType *Ty = new (*this, TypeAlignment) BuiltinType(K);
155  R = CanQualType::CreateUnsafe(QualType(Ty, 0));
156  Types.push_back(Ty);
157}
158
159void ASTContext::InitBuiltinTypes() {
160  assert(VoidTy.isNull() && "Context reinitialized?");
161
162  // C99 6.2.5p19.
163  InitBuiltinType(VoidTy,              BuiltinType::Void);
164
165  // C99 6.2.5p2.
166  InitBuiltinType(BoolTy,              BuiltinType::Bool);
167  // C99 6.2.5p3.
168  if (LangOpts.CharIsSigned)
169    InitBuiltinType(CharTy,            BuiltinType::Char_S);
170  else
171    InitBuiltinType(CharTy,            BuiltinType::Char_U);
172  // C99 6.2.5p4.
173  InitBuiltinType(SignedCharTy,        BuiltinType::SChar);
174  InitBuiltinType(ShortTy,             BuiltinType::Short);
175  InitBuiltinType(IntTy,               BuiltinType::Int);
176  InitBuiltinType(LongTy,              BuiltinType::Long);
177  InitBuiltinType(LongLongTy,          BuiltinType::LongLong);
178
179  // C99 6.2.5p6.
180  InitBuiltinType(UnsignedCharTy,      BuiltinType::UChar);
181  InitBuiltinType(UnsignedShortTy,     BuiltinType::UShort);
182  InitBuiltinType(UnsignedIntTy,       BuiltinType::UInt);
183  InitBuiltinType(UnsignedLongTy,      BuiltinType::ULong);
184  InitBuiltinType(UnsignedLongLongTy,  BuiltinType::ULongLong);
185
186  // C99 6.2.5p10.
187  InitBuiltinType(FloatTy,             BuiltinType::Float);
188  InitBuiltinType(DoubleTy,            BuiltinType::Double);
189  InitBuiltinType(LongDoubleTy,        BuiltinType::LongDouble);
190
191  // GNU extension, 128-bit integers.
192  InitBuiltinType(Int128Ty,            BuiltinType::Int128);
193  InitBuiltinType(UnsignedInt128Ty,    BuiltinType::UInt128);
194
195  if (LangOpts.CPlusPlus) // C++ 3.9.1p5
196    InitBuiltinType(WCharTy,           BuiltinType::WChar);
197  else // C99
198    WCharTy = getFromTargetType(Target.getWCharType());
199
200  if (LangOpts.CPlusPlus) // C++0x 3.9.1p5, extension for C++
201    InitBuiltinType(Char16Ty,           BuiltinType::Char16);
202  else // C99
203    Char16Ty = getFromTargetType(Target.getChar16Type());
204
205  if (LangOpts.CPlusPlus) // C++0x 3.9.1p5, extension for C++
206    InitBuiltinType(Char32Ty,           BuiltinType::Char32);
207  else // C99
208    Char32Ty = getFromTargetType(Target.getChar32Type());
209
210  // Placeholder type for functions.
211  InitBuiltinType(OverloadTy,          BuiltinType::Overload);
212
213  // Placeholder type for type-dependent expressions whose type is
214  // completely unknown. No code should ever check a type against
215  // DependentTy and users should never see it; however, it is here to
216  // help diagnose failures to properly check for type-dependent
217  // expressions.
218  InitBuiltinType(DependentTy,         BuiltinType::Dependent);
219
220  // Placeholder type for C++0x auto declarations whose real type has
221  // not yet been deduced.
222  InitBuiltinType(UndeducedAutoTy, BuiltinType::UndeducedAuto);
223
224  // C99 6.2.5p11.
225  FloatComplexTy      = getComplexType(FloatTy);
226  DoubleComplexTy     = getComplexType(DoubleTy);
227  LongDoubleComplexTy = getComplexType(LongDoubleTy);
228
229  BuiltinVaListType = QualType();
230
231  // "Builtin" typedefs set by Sema::ActOnTranslationUnitScope().
232  ObjCIdTypedefType = QualType();
233  ObjCClassTypedefType = QualType();
234  ObjCSelTypedefType = QualType();
235
236  // Builtin types for 'id', 'Class', and 'SEL'.
237  InitBuiltinType(ObjCBuiltinIdTy, BuiltinType::ObjCId);
238  InitBuiltinType(ObjCBuiltinClassTy, BuiltinType::ObjCClass);
239  InitBuiltinType(ObjCBuiltinSelTy, BuiltinType::ObjCSel);
240
241  ObjCConstantStringType = QualType();
242
243  // void * type
244  VoidPtrTy = getPointerType(VoidTy);
245
246  // nullptr type (C++0x 2.14.7)
247  InitBuiltinType(NullPtrTy,           BuiltinType::NullPtr);
248}
249
250MemberSpecializationInfo *
251ASTContext::getInstantiatedFromStaticDataMember(const VarDecl *Var) {
252  assert(Var->isStaticDataMember() && "Not a static data member");
253  llvm::DenseMap<const VarDecl *, MemberSpecializationInfo *>::iterator Pos
254    = InstantiatedFromStaticDataMember.find(Var);
255  if (Pos == InstantiatedFromStaticDataMember.end())
256    return 0;
257
258  return Pos->second;
259}
260
261void
262ASTContext::setInstantiatedFromStaticDataMember(VarDecl *Inst, VarDecl *Tmpl,
263                                                TemplateSpecializationKind TSK) {
264  assert(Inst->isStaticDataMember() && "Not a static data member");
265  assert(Tmpl->isStaticDataMember() && "Not a static data member");
266  assert(!InstantiatedFromStaticDataMember[Inst] &&
267         "Already noted what static data member was instantiated from");
268  InstantiatedFromStaticDataMember[Inst]
269    = new (*this) MemberSpecializationInfo(Tmpl, TSK);
270}
271
272NamedDecl *
273ASTContext::getInstantiatedFromUsingDecl(UsingDecl *UUD) {
274  llvm::DenseMap<UsingDecl *, NamedDecl *>::const_iterator Pos
275    = InstantiatedFromUsingDecl.find(UUD);
276  if (Pos == InstantiatedFromUsingDecl.end())
277    return 0;
278
279  return Pos->second;
280}
281
282void
283ASTContext::setInstantiatedFromUsingDecl(UsingDecl *Inst, NamedDecl *Pattern) {
284  assert((isa<UsingDecl>(Pattern) ||
285          isa<UnresolvedUsingValueDecl>(Pattern) ||
286          isa<UnresolvedUsingTypenameDecl>(Pattern)) &&
287         "pattern decl is not a using decl");
288  assert(!InstantiatedFromUsingDecl[Inst] && "pattern already exists");
289  InstantiatedFromUsingDecl[Inst] = Pattern;
290}
291
292UsingShadowDecl *
293ASTContext::getInstantiatedFromUsingShadowDecl(UsingShadowDecl *Inst) {
294  llvm::DenseMap<UsingShadowDecl*, UsingShadowDecl*>::const_iterator Pos
295    = InstantiatedFromUsingShadowDecl.find(Inst);
296  if (Pos == InstantiatedFromUsingShadowDecl.end())
297    return 0;
298
299  return Pos->second;
300}
301
302void
303ASTContext::setInstantiatedFromUsingShadowDecl(UsingShadowDecl *Inst,
304                                               UsingShadowDecl *Pattern) {
305  assert(!InstantiatedFromUsingShadowDecl[Inst] && "pattern already exists");
306  InstantiatedFromUsingShadowDecl[Inst] = Pattern;
307}
308
309FieldDecl *ASTContext::getInstantiatedFromUnnamedFieldDecl(FieldDecl *Field) {
310  llvm::DenseMap<FieldDecl *, FieldDecl *>::iterator Pos
311    = InstantiatedFromUnnamedFieldDecl.find(Field);
312  if (Pos == InstantiatedFromUnnamedFieldDecl.end())
313    return 0;
314
315  return Pos->second;
316}
317
318void ASTContext::setInstantiatedFromUnnamedFieldDecl(FieldDecl *Inst,
319                                                     FieldDecl *Tmpl) {
320  assert(!Inst->getDeclName() && "Instantiated field decl is not unnamed");
321  assert(!Tmpl->getDeclName() && "Template field decl is not unnamed");
322  assert(!InstantiatedFromUnnamedFieldDecl[Inst] &&
323         "Already noted what unnamed field was instantiated from");
324
325  InstantiatedFromUnnamedFieldDecl[Inst] = Tmpl;
326}
327
328CXXMethodVector::iterator CXXMethodVector::begin() const {
329  if ((Storage & 0x01) == 0)
330    return reinterpret_cast<iterator>(&Storage);
331
332  vector_type *Vec = reinterpret_cast<vector_type *>(Storage & ~0x01);
333  return &Vec->front();
334}
335
336CXXMethodVector::iterator CXXMethodVector::end() const {
337  if ((Storage & 0x01) == 0) {
338    if (Storage == 0)
339      return reinterpret_cast<iterator>(&Storage);
340
341    return reinterpret_cast<iterator>(&Storage) + 1;
342  }
343
344  vector_type *Vec = reinterpret_cast<vector_type *>(Storage & ~0x01);
345  return &Vec->front() + Vec->size();
346}
347
348void CXXMethodVector::push_back(const CXXMethodDecl *Method) {
349  if (Storage == 0) {
350    // 0 -> 1 element.
351    Storage = reinterpret_cast<uintptr_t>(Method);
352    return;
353  }
354
355  vector_type *Vec;
356  if ((Storage & 0x01) == 0) {
357    // 1 -> 2 elements. Allocate a new vector and push the element into that
358    // vector.
359    Vec = new vector_type;
360    Vec->push_back(reinterpret_cast<const CXXMethodDecl *>(Storage));
361    Storage = reinterpret_cast<uintptr_t>(Vec) | 0x01;
362  } else
363    Vec = reinterpret_cast<vector_type *>(Storage & ~0x01);
364
365  // Add the new method to the vector.
366  Vec->push_back(Method);
367}
368
369void CXXMethodVector::Destroy() {
370  if (Storage & 0x01)
371    delete reinterpret_cast<vector_type *>(Storage & ~0x01);
372
373  Storage = 0;
374}
375
376
377ASTContext::overridden_cxx_method_iterator
378ASTContext::overridden_methods_begin(const CXXMethodDecl *Method) const {
379  llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector>::const_iterator Pos
380    = OverriddenMethods.find(Method);
381  if (Pos == OverriddenMethods.end())
382    return 0;
383
384  return Pos->second.begin();
385}
386
387ASTContext::overridden_cxx_method_iterator
388ASTContext::overridden_methods_end(const CXXMethodDecl *Method) const {
389  llvm::DenseMap<const CXXMethodDecl *, CXXMethodVector>::const_iterator Pos
390    = OverriddenMethods.find(Method);
391  if (Pos == OverriddenMethods.end())
392    return 0;
393
394  return Pos->second.end();
395}
396
397void ASTContext::addOverriddenMethod(const CXXMethodDecl *Method,
398                                     const CXXMethodDecl *Overridden) {
399  OverriddenMethods[Method].push_back(Overridden);
400}
401
402namespace {
403  class BeforeInTranslationUnit
404    : std::binary_function<SourceRange, SourceRange, bool> {
405    SourceManager *SourceMgr;
406
407  public:
408    explicit BeforeInTranslationUnit(SourceManager *SM) : SourceMgr(SM) { }
409
410    bool operator()(SourceRange X, SourceRange Y) {
411      return SourceMgr->isBeforeInTranslationUnit(X.getBegin(), Y.getBegin());
412    }
413  };
414}
415
416//===----------------------------------------------------------------------===//
417//                         Type Sizing and Analysis
418//===----------------------------------------------------------------------===//
419
420/// getFloatTypeSemantics - Return the APFloat 'semantics' for the specified
421/// scalar floating point type.
422const llvm::fltSemantics &ASTContext::getFloatTypeSemantics(QualType T) const {
423  const BuiltinType *BT = T->getAs<BuiltinType>();
424  assert(BT && "Not a floating point type!");
425  switch (BT->getKind()) {
426  default: assert(0 && "Not a floating point type!");
427  case BuiltinType::Float:      return Target.getFloatFormat();
428  case BuiltinType::Double:     return Target.getDoubleFormat();
429  case BuiltinType::LongDouble: return Target.getLongDoubleFormat();
430  }
431}
432
433/// getDeclAlign - Return a conservative estimate of the alignment of the
434/// specified decl.  Note that bitfields do not have a valid alignment, so
435/// this method will assert on them.
436/// If @p RefAsPointee, references are treated like their underlying type
437/// (for alignof), else they're treated like pointers (for CodeGen).
438CharUnits ASTContext::getDeclAlign(const Decl *D, bool RefAsPointee) {
439  unsigned Align = Target.getCharWidth();
440
441  if (const AlignedAttr* AA = D->getAttr<AlignedAttr>())
442    Align = std::max(Align, AA->getMaxAlignment());
443
444  if (const ValueDecl *VD = dyn_cast<ValueDecl>(D)) {
445    QualType T = VD->getType();
446    if (const ReferenceType* RT = T->getAs<ReferenceType>()) {
447      if (RefAsPointee)
448        T = RT->getPointeeType();
449      else
450        T = getPointerType(RT->getPointeeType());
451    }
452    if (!T->isIncompleteType() && !T->isFunctionType()) {
453      // Incomplete or function types default to 1.
454      while (isa<VariableArrayType>(T) || isa<IncompleteArrayType>(T))
455        T = cast<ArrayType>(T)->getElementType();
456
457      Align = std::max(Align, getPreferredTypeAlign(T.getTypePtr()));
458    }
459    if (const FieldDecl *FD = dyn_cast<FieldDecl>(VD)) {
460      // In the case of a field in a packed struct, we want the minimum
461      // of the alignment of the field and the alignment of the struct.
462      Align = std::min(Align,
463        getPreferredTypeAlign(FD->getParent()->getTypeForDecl()));
464    }
465  }
466
467  return CharUnits::fromQuantity(Align / Target.getCharWidth());
468}
469
470/// getTypeSize - Return the size of the specified type, in bits.  This method
471/// does not work on incomplete types.
472///
473/// FIXME: Pointers into different addr spaces could have different sizes and
474/// alignment requirements: getPointerInfo should take an AddrSpace, this
475/// should take a QualType, &c.
476std::pair<uint64_t, unsigned>
477ASTContext::getTypeInfo(const Type *T) {
478  uint64_t Width=0;
479  unsigned Align=8;
480  switch (T->getTypeClass()) {
481#define TYPE(Class, Base)
482#define ABSTRACT_TYPE(Class, Base)
483#define NON_CANONICAL_TYPE(Class, Base)
484#define DEPENDENT_TYPE(Class, Base) case Type::Class:
485#include "clang/AST/TypeNodes.def"
486    assert(false && "Should not see dependent types");
487    break;
488
489  case Type::FunctionNoProto:
490  case Type::FunctionProto:
491    // GCC extension: alignof(function) = 32 bits
492    Width = 0;
493    Align = 32;
494    break;
495
496  case Type::IncompleteArray:
497  case Type::VariableArray:
498    Width = 0;
499    Align = getTypeAlign(cast<ArrayType>(T)->getElementType());
500    break;
501
502  case Type::ConstantArray: {
503    const ConstantArrayType *CAT = cast<ConstantArrayType>(T);
504
505    std::pair<uint64_t, unsigned> EltInfo = getTypeInfo(CAT->getElementType());
506    Width = EltInfo.first*CAT->getSize().getZExtValue();
507    Align = EltInfo.second;
508    break;
509  }
510  case Type::ExtVector:
511  case Type::Vector: {
512    const VectorType *VT = cast<VectorType>(T);
513    std::pair<uint64_t, unsigned> EltInfo = getTypeInfo(VT->getElementType());
514    Width = EltInfo.first*VT->getNumElements();
515    Align = Width;
516    // If the alignment is not a power of 2, round up to the next power of 2.
517    // This happens for non-power-of-2 length vectors.
518    if (VT->getNumElements() & (VT->getNumElements()-1)) {
519      Align = llvm::NextPowerOf2(Align);
520      Width = llvm::RoundUpToAlignment(Width, Align);
521    }
522    break;
523  }
524
525  case Type::Builtin:
526    switch (cast<BuiltinType>(T)->getKind()) {
527    default: assert(0 && "Unknown builtin type!");
528    case BuiltinType::Void:
529      // GCC extension: alignof(void) = 8 bits.
530      Width = 0;
531      Align = 8;
532      break;
533
534    case BuiltinType::Bool:
535      Width = Target.getBoolWidth();
536      Align = Target.getBoolAlign();
537      break;
538    case BuiltinType::Char_S:
539    case BuiltinType::Char_U:
540    case BuiltinType::UChar:
541    case BuiltinType::SChar:
542      Width = Target.getCharWidth();
543      Align = Target.getCharAlign();
544      break;
545    case BuiltinType::WChar:
546      Width = Target.getWCharWidth();
547      Align = Target.getWCharAlign();
548      break;
549    case BuiltinType::Char16:
550      Width = Target.getChar16Width();
551      Align = Target.getChar16Align();
552      break;
553    case BuiltinType::Char32:
554      Width = Target.getChar32Width();
555      Align = Target.getChar32Align();
556      break;
557    case BuiltinType::UShort:
558    case BuiltinType::Short:
559      Width = Target.getShortWidth();
560      Align = Target.getShortAlign();
561      break;
562    case BuiltinType::UInt:
563    case BuiltinType::Int:
564      Width = Target.getIntWidth();
565      Align = Target.getIntAlign();
566      break;
567    case BuiltinType::ULong:
568    case BuiltinType::Long:
569      Width = Target.getLongWidth();
570      Align = Target.getLongAlign();
571      break;
572    case BuiltinType::ULongLong:
573    case BuiltinType::LongLong:
574      Width = Target.getLongLongWidth();
575      Align = Target.getLongLongAlign();
576      break;
577    case BuiltinType::Int128:
578    case BuiltinType::UInt128:
579      Width = 128;
580      Align = 128; // int128_t is 128-bit aligned on all targets.
581      break;
582    case BuiltinType::Float:
583      Width = Target.getFloatWidth();
584      Align = Target.getFloatAlign();
585      break;
586    case BuiltinType::Double:
587      Width = Target.getDoubleWidth();
588      Align = Target.getDoubleAlign();
589      break;
590    case BuiltinType::LongDouble:
591      Width = Target.getLongDoubleWidth();
592      Align = Target.getLongDoubleAlign();
593      break;
594    case BuiltinType::NullPtr:
595      Width = Target.getPointerWidth(0); // C++ 3.9.1p11: sizeof(nullptr_t)
596      Align = Target.getPointerAlign(0); //   == sizeof(void*)
597      break;
598    }
599    break;
600  case Type::ObjCObjectPointer:
601    Width = Target.getPointerWidth(0);
602    Align = Target.getPointerAlign(0);
603    break;
604  case Type::BlockPointer: {
605    unsigned AS = cast<BlockPointerType>(T)->getPointeeType().getAddressSpace();
606    Width = Target.getPointerWidth(AS);
607    Align = Target.getPointerAlign(AS);
608    break;
609  }
610  case Type::LValueReference:
611  case Type::RValueReference: {
612    // alignof and sizeof should never enter this code path here, so we go
613    // the pointer route.
614    unsigned AS = cast<ReferenceType>(T)->getPointeeType().getAddressSpace();
615    Width = Target.getPointerWidth(AS);
616    Align = Target.getPointerAlign(AS);
617    break;
618  }
619  case Type::Pointer: {
620    unsigned AS = cast<PointerType>(T)->getPointeeType().getAddressSpace();
621    Width = Target.getPointerWidth(AS);
622    Align = Target.getPointerAlign(AS);
623    break;
624  }
625  case Type::MemberPointer: {
626    QualType Pointee = cast<MemberPointerType>(T)->getPointeeType();
627    std::pair<uint64_t, unsigned> PtrDiffInfo =
628      getTypeInfo(getPointerDiffType());
629    Width = PtrDiffInfo.first;
630    if (Pointee->isFunctionType())
631      Width *= 2;
632    Align = PtrDiffInfo.second;
633    break;
634  }
635  case Type::Complex: {
636    // Complex types have the same alignment as their elements, but twice the
637    // size.
638    std::pair<uint64_t, unsigned> EltInfo =
639      getTypeInfo(cast<ComplexType>(T)->getElementType());
640    Width = EltInfo.first*2;
641    Align = EltInfo.second;
642    break;
643  }
644  case Type::ObjCInterface: {
645    const ObjCInterfaceType *ObjCI = cast<ObjCInterfaceType>(T);
646    const ASTRecordLayout &Layout = getASTObjCInterfaceLayout(ObjCI->getDecl());
647    Width = Layout.getSize();
648    Align = Layout.getAlignment();
649    break;
650  }
651  case Type::Record:
652  case Type::Enum: {
653    const TagType *TT = cast<TagType>(T);
654
655    if (TT->getDecl()->isInvalidDecl()) {
656      Width = 1;
657      Align = 1;
658      break;
659    }
660
661    if (const EnumType *ET = dyn_cast<EnumType>(TT))
662      return getTypeInfo(ET->getDecl()->getIntegerType());
663
664    const RecordType *RT = cast<RecordType>(TT);
665    const ASTRecordLayout &Layout = getASTRecordLayout(RT->getDecl());
666    Width = Layout.getSize();
667    Align = Layout.getAlignment();
668    break;
669  }
670
671  case Type::SubstTemplateTypeParm:
672    return getTypeInfo(cast<SubstTemplateTypeParmType>(T)->
673                       getReplacementType().getTypePtr());
674
675  case Type::Elaborated:
676    return getTypeInfo(cast<ElaboratedType>(T)->getUnderlyingType()
677                         .getTypePtr());
678
679  case Type::Typedef: {
680    const TypedefDecl *Typedef = cast<TypedefType>(T)->getDecl();
681    if (const AlignedAttr *Aligned = Typedef->getAttr<AlignedAttr>()) {
682      Align = std::max(Aligned->getMaxAlignment(),
683                       getTypeAlign(Typedef->getUnderlyingType().getTypePtr()));
684      Width = getTypeSize(Typedef->getUnderlyingType().getTypePtr());
685    } else
686      return getTypeInfo(Typedef->getUnderlyingType().getTypePtr());
687    break;
688  }
689
690  case Type::TypeOfExpr:
691    return getTypeInfo(cast<TypeOfExprType>(T)->getUnderlyingExpr()->getType()
692                         .getTypePtr());
693
694  case Type::TypeOf:
695    return getTypeInfo(cast<TypeOfType>(T)->getUnderlyingType().getTypePtr());
696
697  case Type::Decltype:
698    return getTypeInfo(cast<DecltypeType>(T)->getUnderlyingExpr()->getType()
699                        .getTypePtr());
700
701  case Type::QualifiedName:
702    return getTypeInfo(cast<QualifiedNameType>(T)->getNamedType().getTypePtr());
703
704 case Type::InjectedClassName:
705   return getTypeInfo(cast<InjectedClassNameType>(T)
706                        ->getUnderlyingType().getTypePtr());
707
708  case Type::TemplateSpecialization:
709    assert(getCanonicalType(T) != T &&
710           "Cannot request the size of a dependent type");
711    // FIXME: this is likely to be wrong once we support template
712    // aliases, since a template alias could refer to a typedef that
713    // has an __aligned__ attribute on it.
714    return getTypeInfo(getCanonicalType(T));
715  }
716
717  assert(Align && (Align & (Align-1)) == 0 && "Alignment must be power of 2");
718  return std::make_pair(Width, Align);
719}
720
721/// getTypeSizeInChars - Return the size of the specified type, in characters.
722/// This method does not work on incomplete types.
723CharUnits ASTContext::getTypeSizeInChars(QualType T) {
724  return CharUnits::fromQuantity(getTypeSize(T) / getCharWidth());
725}
726CharUnits ASTContext::getTypeSizeInChars(const Type *T) {
727  return CharUnits::fromQuantity(getTypeSize(T) / getCharWidth());
728}
729
730/// getTypeAlignInChars - Return the ABI-specified alignment of a type, in
731/// characters. This method does not work on incomplete types.
732CharUnits ASTContext::getTypeAlignInChars(QualType T) {
733  return CharUnits::fromQuantity(getTypeAlign(T) / getCharWidth());
734}
735CharUnits ASTContext::getTypeAlignInChars(const Type *T) {
736  return CharUnits::fromQuantity(getTypeAlign(T) / getCharWidth());
737}
738
739/// getPreferredTypeAlign - Return the "preferred" alignment of the specified
740/// type for the current target in bits.  This can be different than the ABI
741/// alignment in cases where it is beneficial for performance to overalign
742/// a data type.
743unsigned ASTContext::getPreferredTypeAlign(const Type *T) {
744  unsigned ABIAlign = getTypeAlign(T);
745
746  // Double and long long should be naturally aligned if possible.
747  if (const ComplexType* CT = T->getAs<ComplexType>())
748    T = CT->getElementType().getTypePtr();
749  if (T->isSpecificBuiltinType(BuiltinType::Double) ||
750      T->isSpecificBuiltinType(BuiltinType::LongLong))
751    return std::max(ABIAlign, (unsigned)getTypeSize(T));
752
753  return ABIAlign;
754}
755
756static void CollectLocalObjCIvars(ASTContext *Ctx,
757                                  const ObjCInterfaceDecl *OI,
758                                  llvm::SmallVectorImpl<FieldDecl*> &Fields) {
759  for (ObjCInterfaceDecl::ivar_iterator I = OI->ivar_begin(),
760       E = OI->ivar_end(); I != E; ++I) {
761    ObjCIvarDecl *IVDecl = *I;
762    if (!IVDecl->isInvalidDecl())
763      Fields.push_back(cast<FieldDecl>(IVDecl));
764  }
765}
766
767void ASTContext::CollectObjCIvars(const ObjCInterfaceDecl *OI,
768                             llvm::SmallVectorImpl<FieldDecl*> &Fields) {
769  if (const ObjCInterfaceDecl *SuperClass = OI->getSuperClass())
770    CollectObjCIvars(SuperClass, Fields);
771  CollectLocalObjCIvars(this, OI, Fields);
772}
773
774/// ShallowCollectObjCIvars -
775/// Collect all ivars, including those synthesized, in the current class.
776///
777void ASTContext::ShallowCollectObjCIvars(const ObjCInterfaceDecl *OI,
778                                 llvm::SmallVectorImpl<ObjCIvarDecl*> &Ivars) {
779  for (ObjCInterfaceDecl::ivar_iterator I = OI->ivar_begin(),
780         E = OI->ivar_end(); I != E; ++I) {
781     Ivars.push_back(*I);
782  }
783
784  CollectNonClassIvars(OI, Ivars);
785}
786
787/// CollectNonClassIvars -
788/// This routine collects all other ivars which are not declared in the class.
789/// This includes synthesized ivars (via @synthesize) and those in
790//  class's @implementation.
791///
792void ASTContext::CollectNonClassIvars(const ObjCInterfaceDecl *OI,
793                                llvm::SmallVectorImpl<ObjCIvarDecl*> &Ivars) {
794  // Find ivars declared in class extension.
795  if (const ObjCCategoryDecl *CDecl = OI->getClassExtension()) {
796    for (ObjCCategoryDecl::ivar_iterator I = CDecl->ivar_begin(),
797         E = CDecl->ivar_end(); I != E; ++I) {
798      Ivars.push_back(*I);
799    }
800  }
801
802  // Also add any ivar defined in this class's implementation.  This
803  // includes synthesized ivars.
804  if (ObjCImplementationDecl *ImplDecl = OI->getImplementation()) {
805    for (ObjCImplementationDecl::ivar_iterator I = ImplDecl->ivar_begin(),
806         E = ImplDecl->ivar_end(); I != E; ++I)
807      Ivars.push_back(*I);
808  }
809}
810
811/// CollectInheritedProtocols - Collect all protocols in current class and
812/// those inherited by it.
813void ASTContext::CollectInheritedProtocols(const Decl *CDecl,
814                          llvm::SmallPtrSet<ObjCProtocolDecl*, 8> &Protocols) {
815  if (const ObjCInterfaceDecl *OI = dyn_cast<ObjCInterfaceDecl>(CDecl)) {
816    for (ObjCInterfaceDecl::protocol_iterator P = OI->protocol_begin(),
817         PE = OI->protocol_end(); P != PE; ++P) {
818      ObjCProtocolDecl *Proto = (*P);
819      Protocols.insert(Proto);
820      for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
821           PE = Proto->protocol_end(); P != PE; ++P) {
822        Protocols.insert(*P);
823        CollectInheritedProtocols(*P, Protocols);
824      }
825    }
826
827    // Categories of this Interface.
828    for (const ObjCCategoryDecl *CDeclChain = OI->getCategoryList();
829         CDeclChain; CDeclChain = CDeclChain->getNextClassCategory())
830      CollectInheritedProtocols(CDeclChain, Protocols);
831    if (ObjCInterfaceDecl *SD = OI->getSuperClass())
832      while (SD) {
833        CollectInheritedProtocols(SD, Protocols);
834        SD = SD->getSuperClass();
835      }
836    return;
837  }
838  if (const ObjCCategoryDecl *OC = dyn_cast<ObjCCategoryDecl>(CDecl)) {
839    for (ObjCInterfaceDecl::protocol_iterator P = OC->protocol_begin(),
840         PE = OC->protocol_end(); P != PE; ++P) {
841      ObjCProtocolDecl *Proto = (*P);
842      Protocols.insert(Proto);
843      for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
844           PE = Proto->protocol_end(); P != PE; ++P)
845        CollectInheritedProtocols(*P, Protocols);
846    }
847    return;
848  }
849  if (const ObjCProtocolDecl *OP = dyn_cast<ObjCProtocolDecl>(CDecl)) {
850    for (ObjCProtocolDecl::protocol_iterator P = OP->protocol_begin(),
851         PE = OP->protocol_end(); P != PE; ++P) {
852      ObjCProtocolDecl *Proto = (*P);
853      Protocols.insert(Proto);
854      for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
855           PE = Proto->protocol_end(); P != PE; ++P)
856        CollectInheritedProtocols(*P, Protocols);
857    }
858    return;
859  }
860}
861
862unsigned ASTContext::CountNonClassIvars(const ObjCInterfaceDecl *OI) {
863  unsigned count = 0;
864  // Count ivars declared in class extension.
865  if (const ObjCCategoryDecl *CDecl = OI->getClassExtension()) {
866    for (ObjCCategoryDecl::ivar_iterator I = CDecl->ivar_begin(),
867         E = CDecl->ivar_end(); I != E; ++I) {
868      ++count;
869    }
870  }
871
872  // Count ivar defined in this class's implementation.  This
873  // includes synthesized ivars.
874  if (ObjCImplementationDecl *ImplDecl = OI->getImplementation())
875    for (ObjCImplementationDecl::ivar_iterator I = ImplDecl->ivar_begin(),
876         E = ImplDecl->ivar_end(); I != E; ++I)
877      ++count;
878  return count;
879}
880
881/// \brief Get the implementation of ObjCInterfaceDecl,or NULL if none exists.
882ObjCImplementationDecl *ASTContext::getObjCImplementation(ObjCInterfaceDecl *D) {
883  llvm::DenseMap<ObjCContainerDecl*, ObjCImplDecl*>::iterator
884    I = ObjCImpls.find(D);
885  if (I != ObjCImpls.end())
886    return cast<ObjCImplementationDecl>(I->second);
887  return 0;
888}
889/// \brief Get the implementation of ObjCCategoryDecl, or NULL if none exists.
890ObjCCategoryImplDecl *ASTContext::getObjCImplementation(ObjCCategoryDecl *D) {
891  llvm::DenseMap<ObjCContainerDecl*, ObjCImplDecl*>::iterator
892    I = ObjCImpls.find(D);
893  if (I != ObjCImpls.end())
894    return cast<ObjCCategoryImplDecl>(I->second);
895  return 0;
896}
897
898/// \brief Set the implementation of ObjCInterfaceDecl.
899void ASTContext::setObjCImplementation(ObjCInterfaceDecl *IFaceD,
900                           ObjCImplementationDecl *ImplD) {
901  assert(IFaceD && ImplD && "Passed null params");
902  ObjCImpls[IFaceD] = ImplD;
903}
904/// \brief Set the implementation of ObjCCategoryDecl.
905void ASTContext::setObjCImplementation(ObjCCategoryDecl *CatD,
906                           ObjCCategoryImplDecl *ImplD) {
907  assert(CatD && ImplD && "Passed null params");
908  ObjCImpls[CatD] = ImplD;
909}
910
911/// \brief Allocate an uninitialized TypeSourceInfo.
912///
913/// The caller should initialize the memory held by TypeSourceInfo using
914/// the TypeLoc wrappers.
915///
916/// \param T the type that will be the basis for type source info. This type
917/// should refer to how the declarator was written in source code, not to
918/// what type semantic analysis resolved the declarator to.
919TypeSourceInfo *ASTContext::CreateTypeSourceInfo(QualType T,
920                                                 unsigned DataSize) {
921  if (!DataSize)
922    DataSize = TypeLoc::getFullDataSizeForType(T);
923  else
924    assert(DataSize == TypeLoc::getFullDataSizeForType(T) &&
925           "incorrect data size provided to CreateTypeSourceInfo!");
926
927  TypeSourceInfo *TInfo =
928    (TypeSourceInfo*)BumpAlloc.Allocate(sizeof(TypeSourceInfo) + DataSize, 8);
929  new (TInfo) TypeSourceInfo(T);
930  return TInfo;
931}
932
933TypeSourceInfo *ASTContext::getTrivialTypeSourceInfo(QualType T,
934                                                     SourceLocation L) {
935  TypeSourceInfo *DI = CreateTypeSourceInfo(T);
936  DI->getTypeLoc().initialize(L);
937  return DI;
938}
939
940/// getInterfaceLayoutImpl - Get or compute information about the
941/// layout of the given interface.
942///
943/// \param Impl - If given, also include the layout of the interface's
944/// implementation. This may differ by including synthesized ivars.
945const ASTRecordLayout &
946ASTContext::getObjCLayout(const ObjCInterfaceDecl *D,
947                          const ObjCImplementationDecl *Impl) {
948  assert(!D->isForwardDecl() && "Invalid interface decl!");
949
950  // Look up this layout, if already laid out, return what we have.
951  ObjCContainerDecl *Key =
952    Impl ? (ObjCContainerDecl*) Impl : (ObjCContainerDecl*) D;
953  if (const ASTRecordLayout *Entry = ObjCLayouts[Key])
954    return *Entry;
955
956  // Add in synthesized ivar count if laying out an implementation.
957  if (Impl) {
958    unsigned SynthCount = CountNonClassIvars(D);
959    // If there aren't any sythesized ivars then reuse the interface
960    // entry. Note we can't cache this because we simply free all
961    // entries later; however we shouldn't look up implementations
962    // frequently.
963    if (SynthCount == 0)
964      return getObjCLayout(D, 0);
965  }
966
967  const ASTRecordLayout *NewEntry =
968    ASTRecordLayoutBuilder::ComputeLayout(*this, D, Impl);
969  ObjCLayouts[Key] = NewEntry;
970
971  return *NewEntry;
972}
973
974const ASTRecordLayout &
975ASTContext::getASTObjCInterfaceLayout(const ObjCInterfaceDecl *D) {
976  return getObjCLayout(D, 0);
977}
978
979const ASTRecordLayout &
980ASTContext::getASTObjCImplementationLayout(const ObjCImplementationDecl *D) {
981  return getObjCLayout(D->getClassInterface(), D);
982}
983
984/// getASTRecordLayout - Get or compute information about the layout of the
985/// specified record (struct/union/class), which indicates its size and field
986/// position information.
987const ASTRecordLayout &ASTContext::getASTRecordLayout(const RecordDecl *D) {
988  D = D->getDefinition();
989  assert(D && "Cannot get layout of forward declarations!");
990
991  // Look up this layout, if already laid out, return what we have.
992  // Note that we can't save a reference to the entry because this function
993  // is recursive.
994  const ASTRecordLayout *Entry = ASTRecordLayouts[D];
995  if (Entry) return *Entry;
996
997  const ASTRecordLayout *NewEntry =
998    ASTRecordLayoutBuilder::ComputeLayout(*this, D);
999  ASTRecordLayouts[D] = NewEntry;
1000
1001  return *NewEntry;
1002}
1003
1004const CXXMethodDecl *ASTContext::getKeyFunction(const CXXRecordDecl *RD) {
1005  RD = cast<CXXRecordDecl>(RD->getDefinition());
1006  assert(RD && "Cannot get key function for forward declarations!");
1007
1008  const CXXMethodDecl *&Entry = KeyFunctions[RD];
1009  if (!Entry)
1010    Entry = ASTRecordLayoutBuilder::ComputeKeyFunction(RD);
1011  else
1012    assert(Entry == ASTRecordLayoutBuilder::ComputeKeyFunction(RD) &&
1013           "Key function changed!");
1014
1015  return Entry;
1016}
1017
1018//===----------------------------------------------------------------------===//
1019//                   Type creation/memoization methods
1020//===----------------------------------------------------------------------===//
1021
1022QualType ASTContext::getExtQualType(const Type *TypeNode, Qualifiers Quals) {
1023  unsigned Fast = Quals.getFastQualifiers();
1024  Quals.removeFastQualifiers();
1025
1026  // Check if we've already instantiated this type.
1027  llvm::FoldingSetNodeID ID;
1028  ExtQuals::Profile(ID, TypeNode, Quals);
1029  void *InsertPos = 0;
1030  if (ExtQuals *EQ = ExtQualNodes.FindNodeOrInsertPos(ID, InsertPos)) {
1031    assert(EQ->getQualifiers() == Quals);
1032    QualType T = QualType(EQ, Fast);
1033    return T;
1034  }
1035
1036  ExtQuals *New = new (*this, TypeAlignment) ExtQuals(*this, TypeNode, Quals);
1037  ExtQualNodes.InsertNode(New, InsertPos);
1038  QualType T = QualType(New, Fast);
1039  return T;
1040}
1041
1042QualType ASTContext::getVolatileType(QualType T) {
1043  QualType CanT = getCanonicalType(T);
1044  if (CanT.isVolatileQualified()) return T;
1045
1046  QualifierCollector Quals;
1047  const Type *TypeNode = Quals.strip(T);
1048  Quals.addVolatile();
1049
1050  return getExtQualType(TypeNode, Quals);
1051}
1052
1053QualType ASTContext::getAddrSpaceQualType(QualType T, unsigned AddressSpace) {
1054  QualType CanT = getCanonicalType(T);
1055  if (CanT.getAddressSpace() == AddressSpace)
1056    return T;
1057
1058  // If we are composing extended qualifiers together, merge together
1059  // into one ExtQuals node.
1060  QualifierCollector Quals;
1061  const Type *TypeNode = Quals.strip(T);
1062
1063  // If this type already has an address space specified, it cannot get
1064  // another one.
1065  assert(!Quals.hasAddressSpace() &&
1066         "Type cannot be in multiple addr spaces!");
1067  Quals.addAddressSpace(AddressSpace);
1068
1069  return getExtQualType(TypeNode, Quals);
1070}
1071
1072QualType ASTContext::getObjCGCQualType(QualType T,
1073                                       Qualifiers::GC GCAttr) {
1074  QualType CanT = getCanonicalType(T);
1075  if (CanT.getObjCGCAttr() == GCAttr)
1076    return T;
1077
1078  if (T->isPointerType()) {
1079    QualType Pointee = T->getAs<PointerType>()->getPointeeType();
1080    if (Pointee->isAnyPointerType()) {
1081      QualType ResultType = getObjCGCQualType(Pointee, GCAttr);
1082      return getPointerType(ResultType);
1083    }
1084  }
1085
1086  // If we are composing extended qualifiers together, merge together
1087  // into one ExtQuals node.
1088  QualifierCollector Quals;
1089  const Type *TypeNode = Quals.strip(T);
1090
1091  // If this type already has an ObjCGC specified, it cannot get
1092  // another one.
1093  assert(!Quals.hasObjCGCAttr() &&
1094         "Type cannot have multiple ObjCGCs!");
1095  Quals.addObjCGCAttr(GCAttr);
1096
1097  return getExtQualType(TypeNode, Quals);
1098}
1099
1100static QualType getNoReturnCallConvType(ASTContext& Context, QualType T,
1101                                        bool AddNoReturn,
1102                                        CallingConv CallConv) {
1103  QualType ResultType;
1104  if (const PointerType *Pointer = T->getAs<PointerType>()) {
1105    QualType Pointee = Pointer->getPointeeType();
1106    ResultType = getNoReturnCallConvType(Context, Pointee, AddNoReturn,
1107                                         CallConv);
1108    if (ResultType == Pointee)
1109      return T;
1110
1111    ResultType = Context.getPointerType(ResultType);
1112  } else if (const BlockPointerType *BlockPointer
1113                                              = T->getAs<BlockPointerType>()) {
1114    QualType Pointee = BlockPointer->getPointeeType();
1115    ResultType = getNoReturnCallConvType(Context, Pointee, AddNoReturn,
1116                                         CallConv);
1117    if (ResultType == Pointee)
1118      return T;
1119
1120    ResultType = Context.getBlockPointerType(ResultType);
1121   } else if (const FunctionType *F = T->getAs<FunctionType>()) {
1122    if (F->getNoReturnAttr() == AddNoReturn && F->getCallConv() == CallConv)
1123      return T;
1124
1125    if (const FunctionNoProtoType *FNPT = dyn_cast<FunctionNoProtoType>(F)) {
1126      ResultType = Context.getFunctionNoProtoType(FNPT->getResultType(),
1127                                                  AddNoReturn, CallConv);
1128    } else {
1129      const FunctionProtoType *FPT = cast<FunctionProtoType>(F);
1130      ResultType
1131        = Context.getFunctionType(FPT->getResultType(), FPT->arg_type_begin(),
1132                                  FPT->getNumArgs(), FPT->isVariadic(),
1133                                  FPT->getTypeQuals(),
1134                                  FPT->hasExceptionSpec(),
1135                                  FPT->hasAnyExceptionSpec(),
1136                                  FPT->getNumExceptions(),
1137                                  FPT->exception_begin(),
1138                                  AddNoReturn, CallConv);
1139    }
1140  } else
1141    return T;
1142
1143  return Context.getQualifiedType(ResultType, T.getLocalQualifiers());
1144}
1145
1146QualType ASTContext::getNoReturnType(QualType T, bool AddNoReturn) {
1147  return getNoReturnCallConvType(*this, T, AddNoReturn, T.getCallConv());
1148}
1149
1150QualType ASTContext::getCallConvType(QualType T, CallingConv CallConv) {
1151  return getNoReturnCallConvType(*this, T, T.getNoReturnAttr(), CallConv);
1152}
1153
1154/// getComplexType - Return the uniqued reference to the type for a complex
1155/// number with the specified element type.
1156QualType ASTContext::getComplexType(QualType T) {
1157  // Unique pointers, to guarantee there is only one pointer of a particular
1158  // structure.
1159  llvm::FoldingSetNodeID ID;
1160  ComplexType::Profile(ID, T);
1161
1162  void *InsertPos = 0;
1163  if (ComplexType *CT = ComplexTypes.FindNodeOrInsertPos(ID, InsertPos))
1164    return QualType(CT, 0);
1165
1166  // If the pointee type isn't canonical, this won't be a canonical type either,
1167  // so fill in the canonical type field.
1168  QualType Canonical;
1169  if (!T.isCanonical()) {
1170    Canonical = getComplexType(getCanonicalType(T));
1171
1172    // Get the new insert position for the node we care about.
1173    ComplexType *NewIP = ComplexTypes.FindNodeOrInsertPos(ID, InsertPos);
1174    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1175  }
1176  ComplexType *New = new (*this, TypeAlignment) ComplexType(T, Canonical);
1177  Types.push_back(New);
1178  ComplexTypes.InsertNode(New, InsertPos);
1179  return QualType(New, 0);
1180}
1181
1182/// getPointerType - Return the uniqued reference to the type for a pointer to
1183/// the specified type.
1184QualType ASTContext::getPointerType(QualType T) {
1185  // Unique pointers, to guarantee there is only one pointer of a particular
1186  // structure.
1187  llvm::FoldingSetNodeID ID;
1188  PointerType::Profile(ID, T);
1189
1190  void *InsertPos = 0;
1191  if (PointerType *PT = PointerTypes.FindNodeOrInsertPos(ID, InsertPos))
1192    return QualType(PT, 0);
1193
1194  // If the pointee type isn't canonical, this won't be a canonical type either,
1195  // so fill in the canonical type field.
1196  QualType Canonical;
1197  if (!T.isCanonical()) {
1198    Canonical = getPointerType(getCanonicalType(T));
1199
1200    // Get the new insert position for the node we care about.
1201    PointerType *NewIP = PointerTypes.FindNodeOrInsertPos(ID, InsertPos);
1202    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1203  }
1204  PointerType *New = new (*this, TypeAlignment) PointerType(T, Canonical);
1205  Types.push_back(New);
1206  PointerTypes.InsertNode(New, InsertPos);
1207  return QualType(New, 0);
1208}
1209
1210/// getBlockPointerType - Return the uniqued reference to the type for
1211/// a pointer to the specified block.
1212QualType ASTContext::getBlockPointerType(QualType T) {
1213  assert(T->isFunctionType() && "block of function types only");
1214  // Unique pointers, to guarantee there is only one block of a particular
1215  // structure.
1216  llvm::FoldingSetNodeID ID;
1217  BlockPointerType::Profile(ID, T);
1218
1219  void *InsertPos = 0;
1220  if (BlockPointerType *PT =
1221        BlockPointerTypes.FindNodeOrInsertPos(ID, InsertPos))
1222    return QualType(PT, 0);
1223
1224  // If the block pointee type isn't canonical, this won't be a canonical
1225  // type either so fill in the canonical type field.
1226  QualType Canonical;
1227  if (!T.isCanonical()) {
1228    Canonical = getBlockPointerType(getCanonicalType(T));
1229
1230    // Get the new insert position for the node we care about.
1231    BlockPointerType *NewIP =
1232      BlockPointerTypes.FindNodeOrInsertPos(ID, InsertPos);
1233    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1234  }
1235  BlockPointerType *New
1236    = new (*this, TypeAlignment) BlockPointerType(T, Canonical);
1237  Types.push_back(New);
1238  BlockPointerTypes.InsertNode(New, InsertPos);
1239  return QualType(New, 0);
1240}
1241
1242/// getLValueReferenceType - Return the uniqued reference to the type for an
1243/// lvalue reference to the specified type.
1244QualType ASTContext::getLValueReferenceType(QualType T, bool SpelledAsLValue) {
1245  // Unique pointers, to guarantee there is only one pointer of a particular
1246  // structure.
1247  llvm::FoldingSetNodeID ID;
1248  ReferenceType::Profile(ID, T, SpelledAsLValue);
1249
1250  void *InsertPos = 0;
1251  if (LValueReferenceType *RT =
1252        LValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos))
1253    return QualType(RT, 0);
1254
1255  const ReferenceType *InnerRef = T->getAs<ReferenceType>();
1256
1257  // If the referencee type isn't canonical, this won't be a canonical type
1258  // either, so fill in the canonical type field.
1259  QualType Canonical;
1260  if (!SpelledAsLValue || InnerRef || !T.isCanonical()) {
1261    QualType PointeeType = (InnerRef ? InnerRef->getPointeeType() : T);
1262    Canonical = getLValueReferenceType(getCanonicalType(PointeeType));
1263
1264    // Get the new insert position for the node we care about.
1265    LValueReferenceType *NewIP =
1266      LValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos);
1267    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1268  }
1269
1270  LValueReferenceType *New
1271    = new (*this, TypeAlignment) LValueReferenceType(T, Canonical,
1272                                                     SpelledAsLValue);
1273  Types.push_back(New);
1274  LValueReferenceTypes.InsertNode(New, InsertPos);
1275
1276  return QualType(New, 0);
1277}
1278
1279/// getRValueReferenceType - Return the uniqued reference to the type for an
1280/// rvalue reference to the specified type.
1281QualType ASTContext::getRValueReferenceType(QualType T) {
1282  // Unique pointers, to guarantee there is only one pointer of a particular
1283  // structure.
1284  llvm::FoldingSetNodeID ID;
1285  ReferenceType::Profile(ID, T, false);
1286
1287  void *InsertPos = 0;
1288  if (RValueReferenceType *RT =
1289        RValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos))
1290    return QualType(RT, 0);
1291
1292  const ReferenceType *InnerRef = T->getAs<ReferenceType>();
1293
1294  // If the referencee type isn't canonical, this won't be a canonical type
1295  // either, so fill in the canonical type field.
1296  QualType Canonical;
1297  if (InnerRef || !T.isCanonical()) {
1298    QualType PointeeType = (InnerRef ? InnerRef->getPointeeType() : T);
1299    Canonical = getRValueReferenceType(getCanonicalType(PointeeType));
1300
1301    // Get the new insert position for the node we care about.
1302    RValueReferenceType *NewIP =
1303      RValueReferenceTypes.FindNodeOrInsertPos(ID, InsertPos);
1304    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1305  }
1306
1307  RValueReferenceType *New
1308    = new (*this, TypeAlignment) RValueReferenceType(T, Canonical);
1309  Types.push_back(New);
1310  RValueReferenceTypes.InsertNode(New, InsertPos);
1311  return QualType(New, 0);
1312}
1313
1314/// getMemberPointerType - Return the uniqued reference to the type for a
1315/// member pointer to the specified type, in the specified class.
1316QualType ASTContext::getMemberPointerType(QualType T, const Type *Cls) {
1317  // Unique pointers, to guarantee there is only one pointer of a particular
1318  // structure.
1319  llvm::FoldingSetNodeID ID;
1320  MemberPointerType::Profile(ID, T, Cls);
1321
1322  void *InsertPos = 0;
1323  if (MemberPointerType *PT =
1324      MemberPointerTypes.FindNodeOrInsertPos(ID, InsertPos))
1325    return QualType(PT, 0);
1326
1327  // If the pointee or class type isn't canonical, this won't be a canonical
1328  // type either, so fill in the canonical type field.
1329  QualType Canonical;
1330  if (!T.isCanonical() || !Cls->isCanonicalUnqualified()) {
1331    Canonical = getMemberPointerType(getCanonicalType(T),getCanonicalType(Cls));
1332
1333    // Get the new insert position for the node we care about.
1334    MemberPointerType *NewIP =
1335      MemberPointerTypes.FindNodeOrInsertPos(ID, InsertPos);
1336    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1337  }
1338  MemberPointerType *New
1339    = new (*this, TypeAlignment) MemberPointerType(T, Cls, Canonical);
1340  Types.push_back(New);
1341  MemberPointerTypes.InsertNode(New, InsertPos);
1342  return QualType(New, 0);
1343}
1344
1345/// getConstantArrayType - Return the unique reference to the type for an
1346/// array of the specified element type.
1347QualType ASTContext::getConstantArrayType(QualType EltTy,
1348                                          const llvm::APInt &ArySizeIn,
1349                                          ArrayType::ArraySizeModifier ASM,
1350                                          unsigned EltTypeQuals) {
1351  assert((EltTy->isDependentType() ||
1352          EltTy->isIncompleteType() || EltTy->isConstantSizeType()) &&
1353         "Constant array of VLAs is illegal!");
1354
1355  // Convert the array size into a canonical width matching the pointer size for
1356  // the target.
1357  llvm::APInt ArySize(ArySizeIn);
1358  ArySize.zextOrTrunc(Target.getPointerWidth(EltTy.getAddressSpace()));
1359
1360  llvm::FoldingSetNodeID ID;
1361  ConstantArrayType::Profile(ID, EltTy, ArySize, ASM, EltTypeQuals);
1362
1363  void *InsertPos = 0;
1364  if (ConstantArrayType *ATP =
1365      ConstantArrayTypes.FindNodeOrInsertPos(ID, InsertPos))
1366    return QualType(ATP, 0);
1367
1368  // If the element type isn't canonical, this won't be a canonical type either,
1369  // so fill in the canonical type field.
1370  QualType Canonical;
1371  if (!EltTy.isCanonical()) {
1372    Canonical = getConstantArrayType(getCanonicalType(EltTy), ArySize,
1373                                     ASM, EltTypeQuals);
1374    // Get the new insert position for the node we care about.
1375    ConstantArrayType *NewIP =
1376      ConstantArrayTypes.FindNodeOrInsertPos(ID, InsertPos);
1377    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1378  }
1379
1380  ConstantArrayType *New = new(*this,TypeAlignment)
1381    ConstantArrayType(EltTy, Canonical, ArySize, ASM, EltTypeQuals);
1382  ConstantArrayTypes.InsertNode(New, InsertPos);
1383  Types.push_back(New);
1384  return QualType(New, 0);
1385}
1386
1387/// getVariableArrayType - Returns a non-unique reference to the type for a
1388/// variable array of the specified element type.
1389QualType ASTContext::getVariableArrayType(QualType EltTy,
1390                                          Expr *NumElts,
1391                                          ArrayType::ArraySizeModifier ASM,
1392                                          unsigned EltTypeQuals,
1393                                          SourceRange Brackets) {
1394  // Since we don't unique expressions, it isn't possible to unique VLA's
1395  // that have an expression provided for their size.
1396
1397  VariableArrayType *New = new(*this, TypeAlignment)
1398    VariableArrayType(EltTy, QualType(), NumElts, ASM, EltTypeQuals, Brackets);
1399
1400  VariableArrayTypes.push_back(New);
1401  Types.push_back(New);
1402  return QualType(New, 0);
1403}
1404
1405/// getDependentSizedArrayType - Returns a non-unique reference to
1406/// the type for a dependently-sized array of the specified element
1407/// type.
1408QualType ASTContext::getDependentSizedArrayType(QualType EltTy,
1409                                                Expr *NumElts,
1410                                                ArrayType::ArraySizeModifier ASM,
1411                                                unsigned EltTypeQuals,
1412                                                SourceRange Brackets) {
1413  assert((!NumElts || NumElts->isTypeDependent() ||
1414          NumElts->isValueDependent()) &&
1415         "Size must be type- or value-dependent!");
1416
1417  void *InsertPos = 0;
1418  DependentSizedArrayType *Canon = 0;
1419  llvm::FoldingSetNodeID ID;
1420
1421  if (NumElts) {
1422    // Dependently-sized array types that do not have a specified
1423    // number of elements will have their sizes deduced from an
1424    // initializer.
1425    DependentSizedArrayType::Profile(ID, *this, getCanonicalType(EltTy), ASM,
1426                                     EltTypeQuals, NumElts);
1427
1428    Canon = DependentSizedArrayTypes.FindNodeOrInsertPos(ID, InsertPos);
1429  }
1430
1431  DependentSizedArrayType *New;
1432  if (Canon) {
1433    // We already have a canonical version of this array type; use it as
1434    // the canonical type for a newly-built type.
1435    New = new (*this, TypeAlignment)
1436      DependentSizedArrayType(*this, EltTy, QualType(Canon, 0),
1437                              NumElts, ASM, EltTypeQuals, Brackets);
1438  } else {
1439    QualType CanonEltTy = getCanonicalType(EltTy);
1440    if (CanonEltTy == EltTy) {
1441      New = new (*this, TypeAlignment)
1442        DependentSizedArrayType(*this, EltTy, QualType(),
1443                                NumElts, ASM, EltTypeQuals, Brackets);
1444
1445      if (NumElts) {
1446        DependentSizedArrayType *CanonCheck
1447          = DependentSizedArrayTypes.FindNodeOrInsertPos(ID, InsertPos);
1448        assert(!CanonCheck && "Dependent-sized canonical array type broken");
1449        (void)CanonCheck;
1450        DependentSizedArrayTypes.InsertNode(New, InsertPos);
1451      }
1452    } else {
1453      QualType Canon = getDependentSizedArrayType(CanonEltTy, NumElts,
1454                                                  ASM, EltTypeQuals,
1455                                                  SourceRange());
1456      New = new (*this, TypeAlignment)
1457        DependentSizedArrayType(*this, EltTy, Canon,
1458                                NumElts, ASM, EltTypeQuals, Brackets);
1459    }
1460  }
1461
1462  Types.push_back(New);
1463  return QualType(New, 0);
1464}
1465
1466QualType ASTContext::getIncompleteArrayType(QualType EltTy,
1467                                            ArrayType::ArraySizeModifier ASM,
1468                                            unsigned EltTypeQuals) {
1469  llvm::FoldingSetNodeID ID;
1470  IncompleteArrayType::Profile(ID, EltTy, ASM, EltTypeQuals);
1471
1472  void *InsertPos = 0;
1473  if (IncompleteArrayType *ATP =
1474       IncompleteArrayTypes.FindNodeOrInsertPos(ID, InsertPos))
1475    return QualType(ATP, 0);
1476
1477  // If the element type isn't canonical, this won't be a canonical type
1478  // either, so fill in the canonical type field.
1479  QualType Canonical;
1480
1481  if (!EltTy.isCanonical()) {
1482    Canonical = getIncompleteArrayType(getCanonicalType(EltTy),
1483                                       ASM, EltTypeQuals);
1484
1485    // Get the new insert position for the node we care about.
1486    IncompleteArrayType *NewIP =
1487      IncompleteArrayTypes.FindNodeOrInsertPos(ID, InsertPos);
1488    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1489  }
1490
1491  IncompleteArrayType *New = new (*this, TypeAlignment)
1492    IncompleteArrayType(EltTy, Canonical, ASM, EltTypeQuals);
1493
1494  IncompleteArrayTypes.InsertNode(New, InsertPos);
1495  Types.push_back(New);
1496  return QualType(New, 0);
1497}
1498
1499/// getVectorType - Return the unique reference to a vector type of
1500/// the specified element type and size. VectorType must be a built-in type.
1501QualType ASTContext::getVectorType(QualType vecType, unsigned NumElts,
1502                                   bool IsAltiVec, bool IsPixel) {
1503  BuiltinType *baseType;
1504
1505  baseType = dyn_cast<BuiltinType>(getCanonicalType(vecType).getTypePtr());
1506  assert(baseType != 0 && "getVectorType(): Expecting a built-in type");
1507
1508  // Check if we've already instantiated a vector of this type.
1509  llvm::FoldingSetNodeID ID;
1510  VectorType::Profile(ID, vecType, NumElts, Type::Vector,
1511    IsAltiVec, IsPixel);
1512  void *InsertPos = 0;
1513  if (VectorType *VTP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos))
1514    return QualType(VTP, 0);
1515
1516  // If the element type isn't canonical, this won't be a canonical type either,
1517  // so fill in the canonical type field.
1518  QualType Canonical;
1519  if (!vecType.isCanonical() || IsAltiVec || IsPixel) {
1520    Canonical = getVectorType(getCanonicalType(vecType),
1521      NumElts, false, false);
1522
1523    // Get the new insert position for the node we care about.
1524    VectorType *NewIP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1525    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1526  }
1527  VectorType *New = new (*this, TypeAlignment)
1528    VectorType(vecType, NumElts, Canonical, IsAltiVec, IsPixel);
1529  VectorTypes.InsertNode(New, InsertPos);
1530  Types.push_back(New);
1531  return QualType(New, 0);
1532}
1533
1534/// getExtVectorType - Return the unique reference to an extended vector type of
1535/// the specified element type and size. VectorType must be a built-in type.
1536QualType ASTContext::getExtVectorType(QualType vecType, unsigned NumElts) {
1537  BuiltinType *baseType;
1538
1539  baseType = dyn_cast<BuiltinType>(getCanonicalType(vecType).getTypePtr());
1540  assert(baseType != 0 && "getExtVectorType(): Expecting a built-in type");
1541
1542  // Check if we've already instantiated a vector of this type.
1543  llvm::FoldingSetNodeID ID;
1544  VectorType::Profile(ID, vecType, NumElts, Type::ExtVector, false, false);
1545  void *InsertPos = 0;
1546  if (VectorType *VTP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos))
1547    return QualType(VTP, 0);
1548
1549  // If the element type isn't canonical, this won't be a canonical type either,
1550  // so fill in the canonical type field.
1551  QualType Canonical;
1552  if (!vecType.isCanonical()) {
1553    Canonical = getExtVectorType(getCanonicalType(vecType), NumElts);
1554
1555    // Get the new insert position for the node we care about.
1556    VectorType *NewIP = VectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1557    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1558  }
1559  ExtVectorType *New = new (*this, TypeAlignment)
1560    ExtVectorType(vecType, NumElts, Canonical);
1561  VectorTypes.InsertNode(New, InsertPos);
1562  Types.push_back(New);
1563  return QualType(New, 0);
1564}
1565
1566QualType ASTContext::getDependentSizedExtVectorType(QualType vecType,
1567                                                    Expr *SizeExpr,
1568                                                    SourceLocation AttrLoc) {
1569  llvm::FoldingSetNodeID ID;
1570  DependentSizedExtVectorType::Profile(ID, *this, getCanonicalType(vecType),
1571                                       SizeExpr);
1572
1573  void *InsertPos = 0;
1574  DependentSizedExtVectorType *Canon
1575    = DependentSizedExtVectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1576  DependentSizedExtVectorType *New;
1577  if (Canon) {
1578    // We already have a canonical version of this array type; use it as
1579    // the canonical type for a newly-built type.
1580    New = new (*this, TypeAlignment)
1581      DependentSizedExtVectorType(*this, vecType, QualType(Canon, 0),
1582                                  SizeExpr, AttrLoc);
1583  } else {
1584    QualType CanonVecTy = getCanonicalType(vecType);
1585    if (CanonVecTy == vecType) {
1586      New = new (*this, TypeAlignment)
1587        DependentSizedExtVectorType(*this, vecType, QualType(), SizeExpr,
1588                                    AttrLoc);
1589
1590      DependentSizedExtVectorType *CanonCheck
1591        = DependentSizedExtVectorTypes.FindNodeOrInsertPos(ID, InsertPos);
1592      assert(!CanonCheck && "Dependent-sized ext_vector canonical type broken");
1593      (void)CanonCheck;
1594      DependentSizedExtVectorTypes.InsertNode(New, InsertPos);
1595    } else {
1596      QualType Canon = getDependentSizedExtVectorType(CanonVecTy, SizeExpr,
1597                                                      SourceLocation());
1598      New = new (*this, TypeAlignment)
1599        DependentSizedExtVectorType(*this, vecType, Canon, SizeExpr, AttrLoc);
1600    }
1601  }
1602
1603  Types.push_back(New);
1604  return QualType(New, 0);
1605}
1606
1607/// getFunctionNoProtoType - Return a K&R style C function type like 'int()'.
1608///
1609QualType ASTContext::getFunctionNoProtoType(QualType ResultTy, bool NoReturn,
1610                                            CallingConv CallConv) {
1611  // Unique functions, to guarantee there is only one function of a particular
1612  // structure.
1613  llvm::FoldingSetNodeID ID;
1614  FunctionNoProtoType::Profile(ID, ResultTy, NoReturn, CallConv);
1615
1616  void *InsertPos = 0;
1617  if (FunctionNoProtoType *FT =
1618        FunctionNoProtoTypes.FindNodeOrInsertPos(ID, InsertPos))
1619    return QualType(FT, 0);
1620
1621  QualType Canonical;
1622  if (!ResultTy.isCanonical() ||
1623      getCanonicalCallConv(CallConv) != CallConv) {
1624    Canonical = getFunctionNoProtoType(getCanonicalType(ResultTy), NoReturn,
1625                                       getCanonicalCallConv(CallConv));
1626
1627    // Get the new insert position for the node we care about.
1628    FunctionNoProtoType *NewIP =
1629      FunctionNoProtoTypes.FindNodeOrInsertPos(ID, InsertPos);
1630    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1631  }
1632
1633  FunctionNoProtoType *New = new (*this, TypeAlignment)
1634    FunctionNoProtoType(ResultTy, Canonical, NoReturn, CallConv);
1635  Types.push_back(New);
1636  FunctionNoProtoTypes.InsertNode(New, InsertPos);
1637  return QualType(New, 0);
1638}
1639
1640/// getFunctionType - Return a normal function type with a typed argument
1641/// list.  isVariadic indicates whether the argument list includes '...'.
1642QualType ASTContext::getFunctionType(QualType ResultTy,const QualType *ArgArray,
1643                                     unsigned NumArgs, bool isVariadic,
1644                                     unsigned TypeQuals, bool hasExceptionSpec,
1645                                     bool hasAnyExceptionSpec, unsigned NumExs,
1646                                     const QualType *ExArray, bool NoReturn,
1647                                     CallingConv CallConv) {
1648  // Unique functions, to guarantee there is only one function of a particular
1649  // structure.
1650  llvm::FoldingSetNodeID ID;
1651  FunctionProtoType::Profile(ID, ResultTy, ArgArray, NumArgs, isVariadic,
1652                             TypeQuals, hasExceptionSpec, hasAnyExceptionSpec,
1653                             NumExs, ExArray, NoReturn, CallConv);
1654
1655  void *InsertPos = 0;
1656  if (FunctionProtoType *FTP =
1657        FunctionProtoTypes.FindNodeOrInsertPos(ID, InsertPos))
1658    return QualType(FTP, 0);
1659
1660  // Determine whether the type being created is already canonical or not.
1661  bool isCanonical = !hasExceptionSpec && ResultTy.isCanonical();
1662  for (unsigned i = 0; i != NumArgs && isCanonical; ++i)
1663    if (!ArgArray[i].isCanonicalAsParam())
1664      isCanonical = false;
1665
1666  // If this type isn't canonical, get the canonical version of it.
1667  // The exception spec is not part of the canonical type.
1668  QualType Canonical;
1669  if (!isCanonical || getCanonicalCallConv(CallConv) != CallConv) {
1670    llvm::SmallVector<QualType, 16> CanonicalArgs;
1671    CanonicalArgs.reserve(NumArgs);
1672    for (unsigned i = 0; i != NumArgs; ++i)
1673      CanonicalArgs.push_back(getCanonicalParamType(ArgArray[i]));
1674
1675    Canonical = getFunctionType(getCanonicalType(ResultTy),
1676                                CanonicalArgs.data(), NumArgs,
1677                                isVariadic, TypeQuals, false,
1678                                false, 0, 0, NoReturn,
1679                                getCanonicalCallConv(CallConv));
1680
1681    // Get the new insert position for the node we care about.
1682    FunctionProtoType *NewIP =
1683      FunctionProtoTypes.FindNodeOrInsertPos(ID, InsertPos);
1684    assert(NewIP == 0 && "Shouldn't be in the map!"); NewIP = NewIP;
1685  }
1686
1687  // FunctionProtoType objects are allocated with extra bytes after them
1688  // for two variable size arrays (for parameter and exception types) at the
1689  // end of them.
1690  FunctionProtoType *FTP =
1691    (FunctionProtoType*)Allocate(sizeof(FunctionProtoType) +
1692                                 NumArgs*sizeof(QualType) +
1693                                 NumExs*sizeof(QualType), TypeAlignment);
1694  new (FTP) FunctionProtoType(ResultTy, ArgArray, NumArgs, isVariadic,
1695                              TypeQuals, hasExceptionSpec, hasAnyExceptionSpec,
1696                              ExArray, NumExs, Canonical, NoReturn, CallConv);
1697  Types.push_back(FTP);
1698  FunctionProtoTypes.InsertNode(FTP, InsertPos);
1699  return QualType(FTP, 0);
1700}
1701
1702#ifndef NDEBUG
1703static bool NeedsInjectedClassNameType(const RecordDecl *D) {
1704  if (!isa<CXXRecordDecl>(D)) return false;
1705  const CXXRecordDecl *RD = cast<CXXRecordDecl>(D);
1706  if (isa<ClassTemplatePartialSpecializationDecl>(RD))
1707    return true;
1708  if (RD->getDescribedClassTemplate() &&
1709      !isa<ClassTemplateSpecializationDecl>(RD))
1710    return true;
1711  return false;
1712}
1713#endif
1714
1715/// getInjectedClassNameType - Return the unique reference to the
1716/// injected class name type for the specified templated declaration.
1717QualType ASTContext::getInjectedClassNameType(CXXRecordDecl *Decl,
1718                                              QualType TST) {
1719  assert(NeedsInjectedClassNameType(Decl));
1720  if (Decl->TypeForDecl) {
1721    assert(isa<InjectedClassNameType>(Decl->TypeForDecl));
1722  } else if (CXXRecordDecl *PrevDecl
1723               = cast_or_null<CXXRecordDecl>(Decl->getPreviousDeclaration())) {
1724    assert(PrevDecl->TypeForDecl && "previous declaration has no type");
1725    Decl->TypeForDecl = PrevDecl->TypeForDecl;
1726    assert(isa<InjectedClassNameType>(Decl->TypeForDecl));
1727  } else {
1728    Decl->TypeForDecl = new (*this, TypeAlignment)
1729      InjectedClassNameType(Decl, TST, TST->getCanonicalTypeInternal());
1730    Types.push_back(Decl->TypeForDecl);
1731  }
1732  return QualType(Decl->TypeForDecl, 0);
1733}
1734
1735/// getTypeDeclType - Return the unique reference to the type for the
1736/// specified type declaration.
1737QualType ASTContext::getTypeDeclTypeSlow(const TypeDecl *Decl) {
1738  assert(Decl && "Passed null for Decl param");
1739  assert(!Decl->TypeForDecl && "TypeForDecl present in slow case");
1740
1741  if (const TypedefDecl *Typedef = dyn_cast<TypedefDecl>(Decl))
1742    return getTypedefType(Typedef);
1743
1744  if (const ObjCInterfaceDecl *ObjCInterface
1745               = dyn_cast<ObjCInterfaceDecl>(Decl))
1746    return getObjCInterfaceType(ObjCInterface);
1747
1748  assert(!isa<TemplateTypeParmDecl>(Decl) &&
1749         "Template type parameter types are always available.");
1750
1751  if (const RecordDecl *Record = dyn_cast<RecordDecl>(Decl)) {
1752    assert(!Record->getPreviousDeclaration() &&
1753           "struct/union has previous declaration");
1754    assert(!NeedsInjectedClassNameType(Record));
1755    Decl->TypeForDecl = new (*this, TypeAlignment) RecordType(Record);
1756  } else if (const EnumDecl *Enum = dyn_cast<EnumDecl>(Decl)) {
1757    assert(!Enum->getPreviousDeclaration() &&
1758           "enum has previous declaration");
1759    Decl->TypeForDecl = new (*this, TypeAlignment) EnumType(Enum);
1760  } else if (const UnresolvedUsingTypenameDecl *Using =
1761               dyn_cast<UnresolvedUsingTypenameDecl>(Decl)) {
1762    Decl->TypeForDecl = new (*this, TypeAlignment) UnresolvedUsingType(Using);
1763  } else
1764    llvm_unreachable("TypeDecl without a type?");
1765
1766  Types.push_back(Decl->TypeForDecl);
1767  return QualType(Decl->TypeForDecl, 0);
1768}
1769
1770/// getTypedefType - Return the unique reference to the type for the
1771/// specified typename decl.
1772QualType ASTContext::getTypedefType(const TypedefDecl *Decl) {
1773  if (Decl->TypeForDecl) return QualType(Decl->TypeForDecl, 0);
1774
1775  QualType Canonical = getCanonicalType(Decl->getUnderlyingType());
1776  Decl->TypeForDecl = new(*this, TypeAlignment)
1777    TypedefType(Type::Typedef, Decl, Canonical);
1778  Types.push_back(Decl->TypeForDecl);
1779  return QualType(Decl->TypeForDecl, 0);
1780}
1781
1782/// \brief Retrieve a substitution-result type.
1783QualType
1784ASTContext::getSubstTemplateTypeParmType(const TemplateTypeParmType *Parm,
1785                                         QualType Replacement) {
1786  assert(Replacement.isCanonical()
1787         && "replacement types must always be canonical");
1788
1789  llvm::FoldingSetNodeID ID;
1790  SubstTemplateTypeParmType::Profile(ID, Parm, Replacement);
1791  void *InsertPos = 0;
1792  SubstTemplateTypeParmType *SubstParm
1793    = SubstTemplateTypeParmTypes.FindNodeOrInsertPos(ID, InsertPos);
1794
1795  if (!SubstParm) {
1796    SubstParm = new (*this, TypeAlignment)
1797      SubstTemplateTypeParmType(Parm, Replacement);
1798    Types.push_back(SubstParm);
1799    SubstTemplateTypeParmTypes.InsertNode(SubstParm, InsertPos);
1800  }
1801
1802  return QualType(SubstParm, 0);
1803}
1804
1805/// \brief Retrieve the template type parameter type for a template
1806/// parameter or parameter pack with the given depth, index, and (optionally)
1807/// name.
1808QualType ASTContext::getTemplateTypeParmType(unsigned Depth, unsigned Index,
1809                                             bool ParameterPack,
1810                                             IdentifierInfo *Name) {
1811  llvm::FoldingSetNodeID ID;
1812  TemplateTypeParmType::Profile(ID, Depth, Index, ParameterPack, Name);
1813  void *InsertPos = 0;
1814  TemplateTypeParmType *TypeParm
1815    = TemplateTypeParmTypes.FindNodeOrInsertPos(ID, InsertPos);
1816
1817  if (TypeParm)
1818    return QualType(TypeParm, 0);
1819
1820  if (Name) {
1821    QualType Canon = getTemplateTypeParmType(Depth, Index, ParameterPack);
1822    TypeParm = new (*this, TypeAlignment)
1823      TemplateTypeParmType(Depth, Index, ParameterPack, Name, Canon);
1824
1825    TemplateTypeParmType *TypeCheck
1826      = TemplateTypeParmTypes.FindNodeOrInsertPos(ID, InsertPos);
1827    assert(!TypeCheck && "Template type parameter canonical type broken");
1828    (void)TypeCheck;
1829  } else
1830    TypeParm = new (*this, TypeAlignment)
1831      TemplateTypeParmType(Depth, Index, ParameterPack);
1832
1833  Types.push_back(TypeParm);
1834  TemplateTypeParmTypes.InsertNode(TypeParm, InsertPos);
1835
1836  return QualType(TypeParm, 0);
1837}
1838
1839TypeSourceInfo *
1840ASTContext::getTemplateSpecializationTypeInfo(TemplateName Name,
1841                                              SourceLocation NameLoc,
1842                                        const TemplateArgumentListInfo &Args,
1843                                              QualType CanonType) {
1844  QualType TST = getTemplateSpecializationType(Name, Args, CanonType);
1845
1846  TypeSourceInfo *DI = CreateTypeSourceInfo(TST);
1847  TemplateSpecializationTypeLoc TL
1848    = cast<TemplateSpecializationTypeLoc>(DI->getTypeLoc());
1849  TL.setTemplateNameLoc(NameLoc);
1850  TL.setLAngleLoc(Args.getLAngleLoc());
1851  TL.setRAngleLoc(Args.getRAngleLoc());
1852  for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
1853    TL.setArgLocInfo(i, Args[i].getLocInfo());
1854  return DI;
1855}
1856
1857QualType
1858ASTContext::getTemplateSpecializationType(TemplateName Template,
1859                                          const TemplateArgumentListInfo &Args,
1860                                          QualType Canon) {
1861  unsigned NumArgs = Args.size();
1862
1863  llvm::SmallVector<TemplateArgument, 4> ArgVec;
1864  ArgVec.reserve(NumArgs);
1865  for (unsigned i = 0; i != NumArgs; ++i)
1866    ArgVec.push_back(Args[i].getArgument());
1867
1868  return getTemplateSpecializationType(Template, ArgVec.data(), NumArgs, Canon);
1869}
1870
1871QualType
1872ASTContext::getTemplateSpecializationType(TemplateName Template,
1873                                          const TemplateArgument *Args,
1874                                          unsigned NumArgs,
1875                                          QualType Canon) {
1876  if (!Canon.isNull())
1877    Canon = getCanonicalType(Canon);
1878  else {
1879    // Build the canonical template specialization type.
1880    TemplateName CanonTemplate = getCanonicalTemplateName(Template);
1881    llvm::SmallVector<TemplateArgument, 4> CanonArgs;
1882    CanonArgs.reserve(NumArgs);
1883    for (unsigned I = 0; I != NumArgs; ++I)
1884      CanonArgs.push_back(getCanonicalTemplateArgument(Args[I]));
1885
1886    // Determine whether this canonical template specialization type already
1887    // exists.
1888    llvm::FoldingSetNodeID ID;
1889    TemplateSpecializationType::Profile(ID, CanonTemplate,
1890                                        CanonArgs.data(), NumArgs, *this);
1891
1892    void *InsertPos = 0;
1893    TemplateSpecializationType *Spec
1894      = TemplateSpecializationTypes.FindNodeOrInsertPos(ID, InsertPos);
1895
1896    if (!Spec) {
1897      // Allocate a new canonical template specialization type.
1898      void *Mem = Allocate((sizeof(TemplateSpecializationType) +
1899                            sizeof(TemplateArgument) * NumArgs),
1900                           TypeAlignment);
1901      Spec = new (Mem) TemplateSpecializationType(*this, CanonTemplate,
1902                                                  CanonArgs.data(), NumArgs,
1903                                                  Canon);
1904      Types.push_back(Spec);
1905      TemplateSpecializationTypes.InsertNode(Spec, InsertPos);
1906    }
1907
1908    if (Canon.isNull())
1909      Canon = QualType(Spec, 0);
1910    assert(Canon->isDependentType() &&
1911           "Non-dependent template-id type must have a canonical type");
1912  }
1913
1914  // Allocate the (non-canonical) template specialization type, but don't
1915  // try to unique it: these types typically have location information that
1916  // we don't unique and don't want to lose.
1917  void *Mem = Allocate((sizeof(TemplateSpecializationType) +
1918                        sizeof(TemplateArgument) * NumArgs),
1919                       TypeAlignment);
1920  TemplateSpecializationType *Spec
1921    = new (Mem) TemplateSpecializationType(*this, Template, Args, NumArgs,
1922                                           Canon);
1923
1924  Types.push_back(Spec);
1925  return QualType(Spec, 0);
1926}
1927
1928QualType
1929ASTContext::getQualifiedNameType(NestedNameSpecifier *NNS,
1930                                 QualType NamedType) {
1931  llvm::FoldingSetNodeID ID;
1932  QualifiedNameType::Profile(ID, NNS, NamedType);
1933
1934  void *InsertPos = 0;
1935  QualifiedNameType *T
1936    = QualifiedNameTypes.FindNodeOrInsertPos(ID, InsertPos);
1937  if (T)
1938    return QualType(T, 0);
1939
1940  QualType Canon = NamedType;
1941  if (!Canon.isCanonical()) {
1942    Canon = getCanonicalType(NamedType);
1943    QualifiedNameType *CheckT
1944      = QualifiedNameTypes.FindNodeOrInsertPos(ID, InsertPos);
1945    assert(!CheckT && "Qualified name canonical type broken");
1946    (void)CheckT;
1947  }
1948
1949  T = new (*this) QualifiedNameType(NNS, NamedType, Canon);
1950  Types.push_back(T);
1951  QualifiedNameTypes.InsertNode(T, InsertPos);
1952  return QualType(T, 0);
1953}
1954
1955QualType ASTContext::getTypenameType(NestedNameSpecifier *NNS,
1956                                     const IdentifierInfo *Name,
1957                                     QualType Canon) {
1958  assert(NNS->isDependent() && "nested-name-specifier must be dependent");
1959
1960  if (Canon.isNull()) {
1961    NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
1962    if (CanonNNS != NNS)
1963      Canon = getTypenameType(CanonNNS, Name);
1964  }
1965
1966  llvm::FoldingSetNodeID ID;
1967  TypenameType::Profile(ID, NNS, Name);
1968
1969  void *InsertPos = 0;
1970  TypenameType *T
1971    = TypenameTypes.FindNodeOrInsertPos(ID, InsertPos);
1972  if (T)
1973    return QualType(T, 0);
1974
1975  T = new (*this) TypenameType(NNS, Name, Canon);
1976  Types.push_back(T);
1977  TypenameTypes.InsertNode(T, InsertPos);
1978  return QualType(T, 0);
1979}
1980
1981QualType
1982ASTContext::getTypenameType(NestedNameSpecifier *NNS,
1983                            const TemplateSpecializationType *TemplateId,
1984                            QualType Canon) {
1985  assert(NNS->isDependent() && "nested-name-specifier must be dependent");
1986
1987  llvm::FoldingSetNodeID ID;
1988  TypenameType::Profile(ID, NNS, TemplateId);
1989
1990  void *InsertPos = 0;
1991  TypenameType *T
1992    = TypenameTypes.FindNodeOrInsertPos(ID, InsertPos);
1993  if (T)
1994    return QualType(T, 0);
1995
1996  if (Canon.isNull()) {
1997    NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
1998    QualType CanonType = getCanonicalType(QualType(TemplateId, 0));
1999    if (CanonNNS != NNS || CanonType != QualType(TemplateId, 0)) {
2000      const TemplateSpecializationType *CanonTemplateId
2001        = CanonType->getAs<TemplateSpecializationType>();
2002      assert(CanonTemplateId &&
2003             "Canonical type must also be a template specialization type");
2004      Canon = getTypenameType(CanonNNS, CanonTemplateId);
2005    }
2006
2007    TypenameType *CheckT
2008      = TypenameTypes.FindNodeOrInsertPos(ID, InsertPos);
2009    assert(!CheckT && "Typename canonical type is broken"); (void)CheckT;
2010  }
2011
2012  T = new (*this) TypenameType(NNS, TemplateId, Canon);
2013  Types.push_back(T);
2014  TypenameTypes.InsertNode(T, InsertPos);
2015  return QualType(T, 0);
2016}
2017
2018QualType
2019ASTContext::getElaboratedType(QualType UnderlyingType,
2020                              ElaboratedType::TagKind Tag) {
2021  llvm::FoldingSetNodeID ID;
2022  ElaboratedType::Profile(ID, UnderlyingType, Tag);
2023
2024  void *InsertPos = 0;
2025  ElaboratedType *T = ElaboratedTypes.FindNodeOrInsertPos(ID, InsertPos);
2026  if (T)
2027    return QualType(T, 0);
2028
2029  QualType Canon = UnderlyingType;
2030  if (!Canon.isCanonical()) {
2031    Canon = getCanonicalType(Canon);
2032    ElaboratedType *CheckT = ElaboratedTypes.FindNodeOrInsertPos(ID, InsertPos);
2033    assert(!CheckT && "Elaborated canonical type is broken"); (void)CheckT;
2034  }
2035
2036  T = new (*this) ElaboratedType(UnderlyingType, Tag, Canon);
2037  Types.push_back(T);
2038  ElaboratedTypes.InsertNode(T, InsertPos);
2039  return QualType(T, 0);
2040}
2041
2042/// CmpProtocolNames - Comparison predicate for sorting protocols
2043/// alphabetically.
2044static bool CmpProtocolNames(const ObjCProtocolDecl *LHS,
2045                            const ObjCProtocolDecl *RHS) {
2046  return LHS->getDeclName() < RHS->getDeclName();
2047}
2048
2049static bool areSortedAndUniqued(ObjCProtocolDecl **Protocols,
2050                                unsigned NumProtocols) {
2051  if (NumProtocols == 0) return true;
2052
2053  for (unsigned i = 1; i != NumProtocols; ++i)
2054    if (!CmpProtocolNames(Protocols[i-1], Protocols[i]))
2055      return false;
2056  return true;
2057}
2058
2059static void SortAndUniqueProtocols(ObjCProtocolDecl **Protocols,
2060                                   unsigned &NumProtocols) {
2061  ObjCProtocolDecl **ProtocolsEnd = Protocols+NumProtocols;
2062
2063  // Sort protocols, keyed by name.
2064  std::sort(Protocols, Protocols+NumProtocols, CmpProtocolNames);
2065
2066  // Remove duplicates.
2067  ProtocolsEnd = std::unique(Protocols, ProtocolsEnd);
2068  NumProtocols = ProtocolsEnd-Protocols;
2069}
2070
2071/// getObjCObjectPointerType - Return a ObjCObjectPointerType type for
2072/// the given interface decl and the conforming protocol list.
2073QualType ASTContext::getObjCObjectPointerType(QualType InterfaceT,
2074                                              ObjCProtocolDecl **Protocols,
2075                                              unsigned NumProtocols,
2076                                              unsigned Quals) {
2077  llvm::FoldingSetNodeID ID;
2078  ObjCObjectPointerType::Profile(ID, InterfaceT, Protocols, NumProtocols);
2079  Qualifiers Qs = Qualifiers::fromCVRMask(Quals);
2080
2081  void *InsertPos = 0;
2082  if (ObjCObjectPointerType *QT =
2083              ObjCObjectPointerTypes.FindNodeOrInsertPos(ID, InsertPos))
2084    return getQualifiedType(QualType(QT, 0), Qs);
2085
2086  // Sort the protocol list alphabetically to canonicalize it.
2087  QualType Canonical;
2088  if (!InterfaceT.isCanonical() ||
2089      !areSortedAndUniqued(Protocols, NumProtocols)) {
2090    if (!areSortedAndUniqued(Protocols, NumProtocols)) {
2091      llvm::SmallVector<ObjCProtocolDecl*, 8> Sorted(NumProtocols);
2092      unsigned UniqueCount = NumProtocols;
2093
2094      std::copy(Protocols, Protocols + NumProtocols, Sorted.begin());
2095      SortAndUniqueProtocols(&Sorted[0], UniqueCount);
2096
2097      Canonical = getObjCObjectPointerType(getCanonicalType(InterfaceT),
2098                                           &Sorted[0], UniqueCount);
2099    } else {
2100      Canonical = getObjCObjectPointerType(getCanonicalType(InterfaceT),
2101                                           Protocols, NumProtocols);
2102    }
2103
2104    // Regenerate InsertPos.
2105    ObjCObjectPointerTypes.FindNodeOrInsertPos(ID, InsertPos);
2106  }
2107
2108  // No match.
2109  unsigned Size = sizeof(ObjCObjectPointerType)
2110                + NumProtocols * sizeof(ObjCProtocolDecl *);
2111  void *Mem = Allocate(Size, TypeAlignment);
2112  ObjCObjectPointerType *QType = new (Mem) ObjCObjectPointerType(Canonical,
2113                                                                 InterfaceT,
2114                                                                 Protocols,
2115                                                                 NumProtocols);
2116
2117  Types.push_back(QType);
2118  ObjCObjectPointerTypes.InsertNode(QType, InsertPos);
2119  return getQualifiedType(QualType(QType, 0), Qs);
2120}
2121
2122/// getObjCInterfaceType - Return the unique reference to the type for the
2123/// specified ObjC interface decl. The list of protocols is optional.
2124QualType ASTContext::getObjCInterfaceType(const ObjCInterfaceDecl *Decl,
2125                       ObjCProtocolDecl **Protocols, unsigned NumProtocols) {
2126  llvm::FoldingSetNodeID ID;
2127  ObjCInterfaceType::Profile(ID, Decl, Protocols, NumProtocols);
2128
2129  void *InsertPos = 0;
2130  if (ObjCInterfaceType *QT =
2131      ObjCInterfaceTypes.FindNodeOrInsertPos(ID, InsertPos))
2132    return QualType(QT, 0);
2133
2134  // Sort the protocol list alphabetically to canonicalize it.
2135  QualType Canonical;
2136  if (NumProtocols && !areSortedAndUniqued(Protocols, NumProtocols)) {
2137    llvm::SmallVector<ObjCProtocolDecl*, 8> Sorted(NumProtocols);
2138    std::copy(Protocols, Protocols + NumProtocols, Sorted.begin());
2139
2140    unsigned UniqueCount = NumProtocols;
2141    SortAndUniqueProtocols(&Sorted[0], UniqueCount);
2142
2143    Canonical = getObjCInterfaceType(Decl, &Sorted[0], UniqueCount);
2144
2145    ObjCInterfaceTypes.FindNodeOrInsertPos(ID, InsertPos);
2146  }
2147
2148  unsigned Size = sizeof(ObjCInterfaceType)
2149    + NumProtocols * sizeof(ObjCProtocolDecl *);
2150  void *Mem = Allocate(Size, TypeAlignment);
2151  ObjCInterfaceType *QType = new (Mem) ObjCInterfaceType(Canonical,
2152                                        const_cast<ObjCInterfaceDecl*>(Decl),
2153                                                         Protocols,
2154                                                         NumProtocols);
2155
2156  Types.push_back(QType);
2157  ObjCInterfaceTypes.InsertNode(QType, InsertPos);
2158  return QualType(QType, 0);
2159}
2160
2161/// getTypeOfExprType - Unlike many "get<Type>" functions, we can't unique
2162/// TypeOfExprType AST's (since expression's are never shared). For example,
2163/// multiple declarations that refer to "typeof(x)" all contain different
2164/// DeclRefExpr's. This doesn't effect the type checker, since it operates
2165/// on canonical type's (which are always unique).
2166QualType ASTContext::getTypeOfExprType(Expr *tofExpr) {
2167  TypeOfExprType *toe;
2168  if (tofExpr->isTypeDependent()) {
2169    llvm::FoldingSetNodeID ID;
2170    DependentTypeOfExprType::Profile(ID, *this, tofExpr);
2171
2172    void *InsertPos = 0;
2173    DependentTypeOfExprType *Canon
2174      = DependentTypeOfExprTypes.FindNodeOrInsertPos(ID, InsertPos);
2175    if (Canon) {
2176      // We already have a "canonical" version of an identical, dependent
2177      // typeof(expr) type. Use that as our canonical type.
2178      toe = new (*this, TypeAlignment) TypeOfExprType(tofExpr,
2179                                          QualType((TypeOfExprType*)Canon, 0));
2180    }
2181    else {
2182      // Build a new, canonical typeof(expr) type.
2183      Canon
2184        = new (*this, TypeAlignment) DependentTypeOfExprType(*this, tofExpr);
2185      DependentTypeOfExprTypes.InsertNode(Canon, InsertPos);
2186      toe = Canon;
2187    }
2188  } else {
2189    QualType Canonical = getCanonicalType(tofExpr->getType());
2190    toe = new (*this, TypeAlignment) TypeOfExprType(tofExpr, Canonical);
2191  }
2192  Types.push_back(toe);
2193  return QualType(toe, 0);
2194}
2195
2196/// getTypeOfType -  Unlike many "get<Type>" functions, we don't unique
2197/// TypeOfType AST's. The only motivation to unique these nodes would be
2198/// memory savings. Since typeof(t) is fairly uncommon, space shouldn't be
2199/// an issue. This doesn't effect the type checker, since it operates
2200/// on canonical type's (which are always unique).
2201QualType ASTContext::getTypeOfType(QualType tofType) {
2202  QualType Canonical = getCanonicalType(tofType);
2203  TypeOfType *tot = new (*this, TypeAlignment) TypeOfType(tofType, Canonical);
2204  Types.push_back(tot);
2205  return QualType(tot, 0);
2206}
2207
2208/// getDecltypeForExpr - Given an expr, will return the decltype for that
2209/// expression, according to the rules in C++0x [dcl.type.simple]p4
2210static QualType getDecltypeForExpr(const Expr *e, ASTContext &Context) {
2211  if (e->isTypeDependent())
2212    return Context.DependentTy;
2213
2214  // If e is an id expression or a class member access, decltype(e) is defined
2215  // as the type of the entity named by e.
2216  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(e)) {
2217    if (const ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl()))
2218      return VD->getType();
2219  }
2220  if (const MemberExpr *ME = dyn_cast<MemberExpr>(e)) {
2221    if (const FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
2222      return FD->getType();
2223  }
2224  // If e is a function call or an invocation of an overloaded operator,
2225  // (parentheses around e are ignored), decltype(e) is defined as the
2226  // return type of that function.
2227  if (const CallExpr *CE = dyn_cast<CallExpr>(e->IgnoreParens()))
2228    return CE->getCallReturnType();
2229
2230  QualType T = e->getType();
2231
2232  // Otherwise, where T is the type of e, if e is an lvalue, decltype(e) is
2233  // defined as T&, otherwise decltype(e) is defined as T.
2234  if (e->isLvalue(Context) == Expr::LV_Valid)
2235    T = Context.getLValueReferenceType(T);
2236
2237  return T;
2238}
2239
2240/// getDecltypeType -  Unlike many "get<Type>" functions, we don't unique
2241/// DecltypeType AST's. The only motivation to unique these nodes would be
2242/// memory savings. Since decltype(t) is fairly uncommon, space shouldn't be
2243/// an issue. This doesn't effect the type checker, since it operates
2244/// on canonical type's (which are always unique).
2245QualType ASTContext::getDecltypeType(Expr *e) {
2246  DecltypeType *dt;
2247  if (e->isTypeDependent()) {
2248    llvm::FoldingSetNodeID ID;
2249    DependentDecltypeType::Profile(ID, *this, e);
2250
2251    void *InsertPos = 0;
2252    DependentDecltypeType *Canon
2253      = DependentDecltypeTypes.FindNodeOrInsertPos(ID, InsertPos);
2254    if (Canon) {
2255      // We already have a "canonical" version of an equivalent, dependent
2256      // decltype type. Use that as our canonical type.
2257      dt = new (*this, TypeAlignment) DecltypeType(e, DependentTy,
2258                                       QualType((DecltypeType*)Canon, 0));
2259    }
2260    else {
2261      // Build a new, canonical typeof(expr) type.
2262      Canon = new (*this, TypeAlignment) DependentDecltypeType(*this, e);
2263      DependentDecltypeTypes.InsertNode(Canon, InsertPos);
2264      dt = Canon;
2265    }
2266  } else {
2267    QualType T = getDecltypeForExpr(e, *this);
2268    dt = new (*this, TypeAlignment) DecltypeType(e, T, getCanonicalType(T));
2269  }
2270  Types.push_back(dt);
2271  return QualType(dt, 0);
2272}
2273
2274/// getTagDeclType - Return the unique reference to the type for the
2275/// specified TagDecl (struct/union/class/enum) decl.
2276QualType ASTContext::getTagDeclType(const TagDecl *Decl) {
2277  assert (Decl);
2278  // FIXME: What is the design on getTagDeclType when it requires casting
2279  // away const?  mutable?
2280  return getTypeDeclType(const_cast<TagDecl*>(Decl));
2281}
2282
2283/// getSizeType - Return the unique type for "size_t" (C99 7.17), the result
2284/// of the sizeof operator (C99 6.5.3.4p4). The value is target dependent and
2285/// needs to agree with the definition in <stddef.h>.
2286CanQualType ASTContext::getSizeType() const {
2287  return getFromTargetType(Target.getSizeType());
2288}
2289
2290/// getSignedWCharType - Return the type of "signed wchar_t".
2291/// Used when in C++, as a GCC extension.
2292QualType ASTContext::getSignedWCharType() const {
2293  // FIXME: derive from "Target" ?
2294  return WCharTy;
2295}
2296
2297/// getUnsignedWCharType - Return the type of "unsigned wchar_t".
2298/// Used when in C++, as a GCC extension.
2299QualType ASTContext::getUnsignedWCharType() const {
2300  // FIXME: derive from "Target" ?
2301  return UnsignedIntTy;
2302}
2303
2304/// getPointerDiffType - Return the unique type for "ptrdiff_t" (ref?)
2305/// defined in <stddef.h>. Pointer - pointer requires this (C99 6.5.6p9).
2306QualType ASTContext::getPointerDiffType() const {
2307  return getFromTargetType(Target.getPtrDiffType(0));
2308}
2309
2310//===----------------------------------------------------------------------===//
2311//                              Type Operators
2312//===----------------------------------------------------------------------===//
2313
2314CanQualType ASTContext::getCanonicalParamType(QualType T) {
2315  // Push qualifiers into arrays, and then discard any remaining
2316  // qualifiers.
2317  T = getCanonicalType(T);
2318  const Type *Ty = T.getTypePtr();
2319
2320  QualType Result;
2321  if (isa<ArrayType>(Ty)) {
2322    Result = getArrayDecayedType(QualType(Ty,0));
2323  } else if (isa<FunctionType>(Ty)) {
2324    Result = getPointerType(QualType(Ty, 0));
2325  } else {
2326    Result = QualType(Ty, 0);
2327  }
2328
2329  return CanQualType::CreateUnsafe(Result);
2330}
2331
2332/// getCanonicalType - Return the canonical (structural) type corresponding to
2333/// the specified potentially non-canonical type.  The non-canonical version
2334/// of a type may have many "decorated" versions of types.  Decorators can
2335/// include typedefs, 'typeof' operators, etc. The returned type is guaranteed
2336/// to be free of any of these, allowing two canonical types to be compared
2337/// for exact equality with a simple pointer comparison.
2338CanQualType ASTContext::getCanonicalType(QualType T) {
2339  QualifierCollector Quals;
2340  const Type *Ptr = Quals.strip(T);
2341  QualType CanType = Ptr->getCanonicalTypeInternal();
2342
2343  // The canonical internal type will be the canonical type *except*
2344  // that we push type qualifiers down through array types.
2345
2346  // If there are no new qualifiers to push down, stop here.
2347  if (!Quals.hasQualifiers())
2348    return CanQualType::CreateUnsafe(CanType);
2349
2350  // If the type qualifiers are on an array type, get the canonical
2351  // type of the array with the qualifiers applied to the element
2352  // type.
2353  ArrayType *AT = dyn_cast<ArrayType>(CanType);
2354  if (!AT)
2355    return CanQualType::CreateUnsafe(getQualifiedType(CanType, Quals));
2356
2357  // Get the canonical version of the element with the extra qualifiers on it.
2358  // This can recursively sink qualifiers through multiple levels of arrays.
2359  QualType NewEltTy = getQualifiedType(AT->getElementType(), Quals);
2360  NewEltTy = getCanonicalType(NewEltTy);
2361
2362  if (ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
2363    return CanQualType::CreateUnsafe(
2364             getConstantArrayType(NewEltTy, CAT->getSize(),
2365                                  CAT->getSizeModifier(),
2366                                  CAT->getIndexTypeCVRQualifiers()));
2367  if (IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT))
2368    return CanQualType::CreateUnsafe(
2369             getIncompleteArrayType(NewEltTy, IAT->getSizeModifier(),
2370                                    IAT->getIndexTypeCVRQualifiers()));
2371
2372  if (DependentSizedArrayType *DSAT = dyn_cast<DependentSizedArrayType>(AT))
2373    return CanQualType::CreateUnsafe(
2374             getDependentSizedArrayType(NewEltTy,
2375                                        DSAT->getSizeExpr() ?
2376                                          DSAT->getSizeExpr()->Retain() : 0,
2377                                        DSAT->getSizeModifier(),
2378                                        DSAT->getIndexTypeCVRQualifiers(),
2379                        DSAT->getBracketsRange())->getCanonicalTypeInternal());
2380
2381  VariableArrayType *VAT = cast<VariableArrayType>(AT);
2382  return CanQualType::CreateUnsafe(getVariableArrayType(NewEltTy,
2383                                                        VAT->getSizeExpr() ?
2384                                              VAT->getSizeExpr()->Retain() : 0,
2385                                                        VAT->getSizeModifier(),
2386                                              VAT->getIndexTypeCVRQualifiers(),
2387                                                     VAT->getBracketsRange()));
2388}
2389
2390QualType ASTContext::getUnqualifiedArrayType(QualType T,
2391                                             Qualifiers &Quals) {
2392  Quals = T.getQualifiers();
2393  if (!isa<ArrayType>(T)) {
2394    return T.getUnqualifiedType();
2395  }
2396
2397  const ArrayType *AT = cast<ArrayType>(T);
2398  QualType Elt = AT->getElementType();
2399  QualType UnqualElt = getUnqualifiedArrayType(Elt, Quals);
2400  if (Elt == UnqualElt)
2401    return T;
2402
2403  if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(T)) {
2404    return getConstantArrayType(UnqualElt, CAT->getSize(),
2405                                CAT->getSizeModifier(), 0);
2406  }
2407
2408  if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(T)) {
2409    return getIncompleteArrayType(UnqualElt, IAT->getSizeModifier(), 0);
2410  }
2411
2412  const DependentSizedArrayType *DSAT = cast<DependentSizedArrayType>(T);
2413  return getDependentSizedArrayType(UnqualElt, DSAT->getSizeExpr()->Retain(),
2414                                    DSAT->getSizeModifier(), 0,
2415                                    SourceRange());
2416}
2417
2418DeclarationName ASTContext::getNameForTemplate(TemplateName Name) {
2419  if (TemplateDecl *TD = Name.getAsTemplateDecl())
2420    return TD->getDeclName();
2421
2422  if (DependentTemplateName *DTN = Name.getAsDependentTemplateName()) {
2423    if (DTN->isIdentifier()) {
2424      return DeclarationNames.getIdentifier(DTN->getIdentifier());
2425    } else {
2426      return DeclarationNames.getCXXOperatorName(DTN->getOperator());
2427    }
2428  }
2429
2430  OverloadedTemplateStorage *Storage = Name.getAsOverloadedTemplate();
2431  assert(Storage);
2432  return (*Storage->begin())->getDeclName();
2433}
2434
2435TemplateName ASTContext::getCanonicalTemplateName(TemplateName Name) {
2436  // If this template name refers to a template, the canonical
2437  // template name merely stores the template itself.
2438  if (TemplateDecl *Template = Name.getAsTemplateDecl())
2439    return TemplateName(cast<TemplateDecl>(Template->getCanonicalDecl()));
2440
2441  assert(!Name.getAsOverloadedTemplate());
2442
2443  DependentTemplateName *DTN = Name.getAsDependentTemplateName();
2444  assert(DTN && "Non-dependent template names must refer to template decls.");
2445  return DTN->CanonicalTemplateName;
2446}
2447
2448bool ASTContext::hasSameTemplateName(TemplateName X, TemplateName Y) {
2449  X = getCanonicalTemplateName(X);
2450  Y = getCanonicalTemplateName(Y);
2451  return X.getAsVoidPointer() == Y.getAsVoidPointer();
2452}
2453
2454TemplateArgument
2455ASTContext::getCanonicalTemplateArgument(const TemplateArgument &Arg) {
2456  switch (Arg.getKind()) {
2457    case TemplateArgument::Null:
2458      return Arg;
2459
2460    case TemplateArgument::Expression:
2461      return Arg;
2462
2463    case TemplateArgument::Declaration:
2464      return TemplateArgument(Arg.getAsDecl()->getCanonicalDecl());
2465
2466    case TemplateArgument::Template:
2467      return TemplateArgument(getCanonicalTemplateName(Arg.getAsTemplate()));
2468
2469    case TemplateArgument::Integral:
2470      return TemplateArgument(*Arg.getAsIntegral(),
2471                              getCanonicalType(Arg.getIntegralType()));
2472
2473    case TemplateArgument::Type:
2474      return TemplateArgument(getCanonicalType(Arg.getAsType()));
2475
2476    case TemplateArgument::Pack: {
2477      // FIXME: Allocate in ASTContext
2478      TemplateArgument *CanonArgs = new TemplateArgument[Arg.pack_size()];
2479      unsigned Idx = 0;
2480      for (TemplateArgument::pack_iterator A = Arg.pack_begin(),
2481                                        AEnd = Arg.pack_end();
2482           A != AEnd; (void)++A, ++Idx)
2483        CanonArgs[Idx] = getCanonicalTemplateArgument(*A);
2484
2485      TemplateArgument Result;
2486      Result.setArgumentPack(CanonArgs, Arg.pack_size(), false);
2487      return Result;
2488    }
2489  }
2490
2491  // Silence GCC warning
2492  assert(false && "Unhandled template argument kind");
2493  return TemplateArgument();
2494}
2495
2496NestedNameSpecifier *
2497ASTContext::getCanonicalNestedNameSpecifier(NestedNameSpecifier *NNS) {
2498  if (!NNS)
2499    return 0;
2500
2501  switch (NNS->getKind()) {
2502  case NestedNameSpecifier::Identifier:
2503    // Canonicalize the prefix but keep the identifier the same.
2504    return NestedNameSpecifier::Create(*this,
2505                         getCanonicalNestedNameSpecifier(NNS->getPrefix()),
2506                                       NNS->getAsIdentifier());
2507
2508  case NestedNameSpecifier::Namespace:
2509    // A namespace is canonical; build a nested-name-specifier with
2510    // this namespace and no prefix.
2511    return NestedNameSpecifier::Create(*this, 0, NNS->getAsNamespace());
2512
2513  case NestedNameSpecifier::TypeSpec:
2514  case NestedNameSpecifier::TypeSpecWithTemplate: {
2515    QualType T = getCanonicalType(QualType(NNS->getAsType(), 0));
2516    return NestedNameSpecifier::Create(*this, 0,
2517                 NNS->getKind() == NestedNameSpecifier::TypeSpecWithTemplate,
2518                                       T.getTypePtr());
2519  }
2520
2521  case NestedNameSpecifier::Global:
2522    // The global specifier is canonical and unique.
2523    return NNS;
2524  }
2525
2526  // Required to silence a GCC warning
2527  return 0;
2528}
2529
2530
2531const ArrayType *ASTContext::getAsArrayType(QualType T) {
2532  // Handle the non-qualified case efficiently.
2533  if (!T.hasLocalQualifiers()) {
2534    // Handle the common positive case fast.
2535    if (const ArrayType *AT = dyn_cast<ArrayType>(T))
2536      return AT;
2537  }
2538
2539  // Handle the common negative case fast.
2540  QualType CType = T->getCanonicalTypeInternal();
2541  if (!isa<ArrayType>(CType))
2542    return 0;
2543
2544  // Apply any qualifiers from the array type to the element type.  This
2545  // implements C99 6.7.3p8: "If the specification of an array type includes
2546  // any type qualifiers, the element type is so qualified, not the array type."
2547
2548  // If we get here, we either have type qualifiers on the type, or we have
2549  // sugar such as a typedef in the way.  If we have type qualifiers on the type
2550  // we must propagate them down into the element type.
2551
2552  QualifierCollector Qs;
2553  const Type *Ty = Qs.strip(T.getDesugaredType());
2554
2555  // If we have a simple case, just return now.
2556  const ArrayType *ATy = dyn_cast<ArrayType>(Ty);
2557  if (ATy == 0 || Qs.empty())
2558    return ATy;
2559
2560  // Otherwise, we have an array and we have qualifiers on it.  Push the
2561  // qualifiers into the array element type and return a new array type.
2562  // Get the canonical version of the element with the extra qualifiers on it.
2563  // This can recursively sink qualifiers through multiple levels of arrays.
2564  QualType NewEltTy = getQualifiedType(ATy->getElementType(), Qs);
2565
2566  if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(ATy))
2567    return cast<ArrayType>(getConstantArrayType(NewEltTy, CAT->getSize(),
2568                                                CAT->getSizeModifier(),
2569                                           CAT->getIndexTypeCVRQualifiers()));
2570  if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(ATy))
2571    return cast<ArrayType>(getIncompleteArrayType(NewEltTy,
2572                                                  IAT->getSizeModifier(),
2573                                           IAT->getIndexTypeCVRQualifiers()));
2574
2575  if (const DependentSizedArrayType *DSAT
2576        = dyn_cast<DependentSizedArrayType>(ATy))
2577    return cast<ArrayType>(
2578                     getDependentSizedArrayType(NewEltTy,
2579                                                DSAT->getSizeExpr() ?
2580                                              DSAT->getSizeExpr()->Retain() : 0,
2581                                                DSAT->getSizeModifier(),
2582                                              DSAT->getIndexTypeCVRQualifiers(),
2583                                                DSAT->getBracketsRange()));
2584
2585  const VariableArrayType *VAT = cast<VariableArrayType>(ATy);
2586  return cast<ArrayType>(getVariableArrayType(NewEltTy,
2587                                              VAT->getSizeExpr() ?
2588                                              VAT->getSizeExpr()->Retain() : 0,
2589                                              VAT->getSizeModifier(),
2590                                              VAT->getIndexTypeCVRQualifiers(),
2591                                              VAT->getBracketsRange()));
2592}
2593
2594
2595/// getArrayDecayedType - Return the properly qualified result of decaying the
2596/// specified array type to a pointer.  This operation is non-trivial when
2597/// handling typedefs etc.  The canonical type of "T" must be an array type,
2598/// this returns a pointer to a properly qualified element of the array.
2599///
2600/// See C99 6.7.5.3p7 and C99 6.3.2.1p3.
2601QualType ASTContext::getArrayDecayedType(QualType Ty) {
2602  // Get the element type with 'getAsArrayType' so that we don't lose any
2603  // typedefs in the element type of the array.  This also handles propagation
2604  // of type qualifiers from the array type into the element type if present
2605  // (C99 6.7.3p8).
2606  const ArrayType *PrettyArrayType = getAsArrayType(Ty);
2607  assert(PrettyArrayType && "Not an array type!");
2608
2609  QualType PtrTy = getPointerType(PrettyArrayType->getElementType());
2610
2611  // int x[restrict 4] ->  int *restrict
2612  return getQualifiedType(PtrTy, PrettyArrayType->getIndexTypeQualifiers());
2613}
2614
2615QualType ASTContext::getBaseElementType(QualType QT) {
2616  QualifierCollector Qs;
2617  while (true) {
2618    const Type *UT = Qs.strip(QT);
2619    if (const ArrayType *AT = getAsArrayType(QualType(UT,0))) {
2620      QT = AT->getElementType();
2621    } else {
2622      return Qs.apply(QT);
2623    }
2624  }
2625}
2626
2627QualType ASTContext::getBaseElementType(const ArrayType *AT) {
2628  QualType ElemTy = AT->getElementType();
2629
2630  if (const ArrayType *AT = getAsArrayType(ElemTy))
2631    return getBaseElementType(AT);
2632
2633  return ElemTy;
2634}
2635
2636/// getConstantArrayElementCount - Returns number of constant array elements.
2637uint64_t
2638ASTContext::getConstantArrayElementCount(const ConstantArrayType *CA)  const {
2639  uint64_t ElementCount = 1;
2640  do {
2641    ElementCount *= CA->getSize().getZExtValue();
2642    CA = dyn_cast<ConstantArrayType>(CA->getElementType());
2643  } while (CA);
2644  return ElementCount;
2645}
2646
2647/// getFloatingRank - Return a relative rank for floating point types.
2648/// This routine will assert if passed a built-in type that isn't a float.
2649static FloatingRank getFloatingRank(QualType T) {
2650  if (const ComplexType *CT = T->getAs<ComplexType>())
2651    return getFloatingRank(CT->getElementType());
2652
2653  assert(T->getAs<BuiltinType>() && "getFloatingRank(): not a floating type");
2654  switch (T->getAs<BuiltinType>()->getKind()) {
2655  default: assert(0 && "getFloatingRank(): not a floating type");
2656  case BuiltinType::Float:      return FloatRank;
2657  case BuiltinType::Double:     return DoubleRank;
2658  case BuiltinType::LongDouble: return LongDoubleRank;
2659  }
2660}
2661
2662/// getFloatingTypeOfSizeWithinDomain - Returns a real floating
2663/// point or a complex type (based on typeDomain/typeSize).
2664/// 'typeDomain' is a real floating point or complex type.
2665/// 'typeSize' is a real floating point or complex type.
2666QualType ASTContext::getFloatingTypeOfSizeWithinDomain(QualType Size,
2667                                                       QualType Domain) const {
2668  FloatingRank EltRank = getFloatingRank(Size);
2669  if (Domain->isComplexType()) {
2670    switch (EltRank) {
2671    default: assert(0 && "getFloatingRank(): illegal value for rank");
2672    case FloatRank:      return FloatComplexTy;
2673    case DoubleRank:     return DoubleComplexTy;
2674    case LongDoubleRank: return LongDoubleComplexTy;
2675    }
2676  }
2677
2678  assert(Domain->isRealFloatingType() && "Unknown domain!");
2679  switch (EltRank) {
2680  default: assert(0 && "getFloatingRank(): illegal value for rank");
2681  case FloatRank:      return FloatTy;
2682  case DoubleRank:     return DoubleTy;
2683  case LongDoubleRank: return LongDoubleTy;
2684  }
2685}
2686
2687/// getFloatingTypeOrder - Compare the rank of the two specified floating
2688/// point types, ignoring the domain of the type (i.e. 'double' ==
2689/// '_Complex double').  If LHS > RHS, return 1.  If LHS == RHS, return 0. If
2690/// LHS < RHS, return -1.
2691int ASTContext::getFloatingTypeOrder(QualType LHS, QualType RHS) {
2692  FloatingRank LHSR = getFloatingRank(LHS);
2693  FloatingRank RHSR = getFloatingRank(RHS);
2694
2695  if (LHSR == RHSR)
2696    return 0;
2697  if (LHSR > RHSR)
2698    return 1;
2699  return -1;
2700}
2701
2702/// getIntegerRank - Return an integer conversion rank (C99 6.3.1.1p1). This
2703/// routine will assert if passed a built-in type that isn't an integer or enum,
2704/// or if it is not canonicalized.
2705unsigned ASTContext::getIntegerRank(Type *T) {
2706  assert(T->isCanonicalUnqualified() && "T should be canonicalized");
2707  if (EnumType* ET = dyn_cast<EnumType>(T))
2708    T = ET->getDecl()->getPromotionType().getTypePtr();
2709
2710  if (T->isSpecificBuiltinType(BuiltinType::WChar))
2711    T = getFromTargetType(Target.getWCharType()).getTypePtr();
2712
2713  if (T->isSpecificBuiltinType(BuiltinType::Char16))
2714    T = getFromTargetType(Target.getChar16Type()).getTypePtr();
2715
2716  if (T->isSpecificBuiltinType(BuiltinType::Char32))
2717    T = getFromTargetType(Target.getChar32Type()).getTypePtr();
2718
2719  switch (cast<BuiltinType>(T)->getKind()) {
2720  default: assert(0 && "getIntegerRank(): not a built-in integer");
2721  case BuiltinType::Bool:
2722    return 1 + (getIntWidth(BoolTy) << 3);
2723  case BuiltinType::Char_S:
2724  case BuiltinType::Char_U:
2725  case BuiltinType::SChar:
2726  case BuiltinType::UChar:
2727    return 2 + (getIntWidth(CharTy) << 3);
2728  case BuiltinType::Short:
2729  case BuiltinType::UShort:
2730    return 3 + (getIntWidth(ShortTy) << 3);
2731  case BuiltinType::Int:
2732  case BuiltinType::UInt:
2733    return 4 + (getIntWidth(IntTy) << 3);
2734  case BuiltinType::Long:
2735  case BuiltinType::ULong:
2736    return 5 + (getIntWidth(LongTy) << 3);
2737  case BuiltinType::LongLong:
2738  case BuiltinType::ULongLong:
2739    return 6 + (getIntWidth(LongLongTy) << 3);
2740  case BuiltinType::Int128:
2741  case BuiltinType::UInt128:
2742    return 7 + (getIntWidth(Int128Ty) << 3);
2743  }
2744}
2745
2746/// \brief Whether this is a promotable bitfield reference according
2747/// to C99 6.3.1.1p2, bullet 2 (and GCC extensions).
2748///
2749/// \returns the type this bit-field will promote to, or NULL if no
2750/// promotion occurs.
2751QualType ASTContext::isPromotableBitField(Expr *E) {
2752  FieldDecl *Field = E->getBitField();
2753  if (!Field)
2754    return QualType();
2755
2756  QualType FT = Field->getType();
2757
2758  llvm::APSInt BitWidthAP = Field->getBitWidth()->EvaluateAsInt(*this);
2759  uint64_t BitWidth = BitWidthAP.getZExtValue();
2760  uint64_t IntSize = getTypeSize(IntTy);
2761  // GCC extension compatibility: if the bit-field size is less than or equal
2762  // to the size of int, it gets promoted no matter what its type is.
2763  // For instance, unsigned long bf : 4 gets promoted to signed int.
2764  if (BitWidth < IntSize)
2765    return IntTy;
2766
2767  if (BitWidth == IntSize)
2768    return FT->isSignedIntegerType() ? IntTy : UnsignedIntTy;
2769
2770  // Types bigger than int are not subject to promotions, and therefore act
2771  // like the base type.
2772  // FIXME: This doesn't quite match what gcc does, but what gcc does here
2773  // is ridiculous.
2774  return QualType();
2775}
2776
2777/// getPromotedIntegerType - Returns the type that Promotable will
2778/// promote to: C99 6.3.1.1p2, assuming that Promotable is a promotable
2779/// integer type.
2780QualType ASTContext::getPromotedIntegerType(QualType Promotable) {
2781  assert(!Promotable.isNull());
2782  assert(Promotable->isPromotableIntegerType());
2783  if (const EnumType *ET = Promotable->getAs<EnumType>())
2784    return ET->getDecl()->getPromotionType();
2785  if (Promotable->isSignedIntegerType())
2786    return IntTy;
2787  uint64_t PromotableSize = getTypeSize(Promotable);
2788  uint64_t IntSize = getTypeSize(IntTy);
2789  assert(Promotable->isUnsignedIntegerType() && PromotableSize <= IntSize);
2790  return (PromotableSize != IntSize) ? IntTy : UnsignedIntTy;
2791}
2792
2793/// getIntegerTypeOrder - Returns the highest ranked integer type:
2794/// C99 6.3.1.8p1.  If LHS > RHS, return 1.  If LHS == RHS, return 0. If
2795/// LHS < RHS, return -1.
2796int ASTContext::getIntegerTypeOrder(QualType LHS, QualType RHS) {
2797  Type *LHSC = getCanonicalType(LHS).getTypePtr();
2798  Type *RHSC = getCanonicalType(RHS).getTypePtr();
2799  if (LHSC == RHSC) return 0;
2800
2801  bool LHSUnsigned = LHSC->isUnsignedIntegerType();
2802  bool RHSUnsigned = RHSC->isUnsignedIntegerType();
2803
2804  unsigned LHSRank = getIntegerRank(LHSC);
2805  unsigned RHSRank = getIntegerRank(RHSC);
2806
2807  if (LHSUnsigned == RHSUnsigned) {  // Both signed or both unsigned.
2808    if (LHSRank == RHSRank) return 0;
2809    return LHSRank > RHSRank ? 1 : -1;
2810  }
2811
2812  // Otherwise, the LHS is signed and the RHS is unsigned or visa versa.
2813  if (LHSUnsigned) {
2814    // If the unsigned [LHS] type is larger, return it.
2815    if (LHSRank >= RHSRank)
2816      return 1;
2817
2818    // If the signed type can represent all values of the unsigned type, it
2819    // wins.  Because we are dealing with 2's complement and types that are
2820    // powers of two larger than each other, this is always safe.
2821    return -1;
2822  }
2823
2824  // If the unsigned [RHS] type is larger, return it.
2825  if (RHSRank >= LHSRank)
2826    return -1;
2827
2828  // If the signed type can represent all values of the unsigned type, it
2829  // wins.  Because we are dealing with 2's complement and types that are
2830  // powers of two larger than each other, this is always safe.
2831  return 1;
2832}
2833
2834static RecordDecl *
2835CreateRecordDecl(ASTContext &Ctx, RecordDecl::TagKind TK, DeclContext *DC,
2836                 SourceLocation L, IdentifierInfo *Id) {
2837  if (Ctx.getLangOptions().CPlusPlus)
2838    return CXXRecordDecl::Create(Ctx, TK, DC, L, Id);
2839  else
2840    return RecordDecl::Create(Ctx, TK, DC, L, Id);
2841}
2842
2843// getCFConstantStringType - Return the type used for constant CFStrings.
2844QualType ASTContext::getCFConstantStringType() {
2845  if (!CFConstantStringTypeDecl) {
2846    CFConstantStringTypeDecl =
2847      CreateRecordDecl(*this, TagDecl::TK_struct, TUDecl, SourceLocation(),
2848                       &Idents.get("NSConstantString"));
2849    CFConstantStringTypeDecl->startDefinition();
2850
2851    QualType FieldTypes[4];
2852
2853    // const int *isa;
2854    FieldTypes[0] = getPointerType(IntTy.withConst());
2855    // int flags;
2856    FieldTypes[1] = IntTy;
2857    // const char *str;
2858    FieldTypes[2] = getPointerType(CharTy.withConst());
2859    // long length;
2860    FieldTypes[3] = LongTy;
2861
2862    // Create fields
2863    for (unsigned i = 0; i < 4; ++i) {
2864      FieldDecl *Field = FieldDecl::Create(*this, CFConstantStringTypeDecl,
2865                                           SourceLocation(), 0,
2866                                           FieldTypes[i], /*TInfo=*/0,
2867                                           /*BitWidth=*/0,
2868                                           /*Mutable=*/false);
2869      CFConstantStringTypeDecl->addDecl(Field);
2870    }
2871
2872    CFConstantStringTypeDecl->completeDefinition();
2873  }
2874
2875  return getTagDeclType(CFConstantStringTypeDecl);
2876}
2877
2878void ASTContext::setCFConstantStringType(QualType T) {
2879  const RecordType *Rec = T->getAs<RecordType>();
2880  assert(Rec && "Invalid CFConstantStringType");
2881  CFConstantStringTypeDecl = Rec->getDecl();
2882}
2883
2884QualType ASTContext::getObjCFastEnumerationStateType() {
2885  if (!ObjCFastEnumerationStateTypeDecl) {
2886    ObjCFastEnumerationStateTypeDecl =
2887      CreateRecordDecl(*this, TagDecl::TK_struct, TUDecl, SourceLocation(),
2888                       &Idents.get("__objcFastEnumerationState"));
2889    ObjCFastEnumerationStateTypeDecl->startDefinition();
2890
2891    QualType FieldTypes[] = {
2892      UnsignedLongTy,
2893      getPointerType(ObjCIdTypedefType),
2894      getPointerType(UnsignedLongTy),
2895      getConstantArrayType(UnsignedLongTy,
2896                           llvm::APInt(32, 5), ArrayType::Normal, 0)
2897    };
2898
2899    for (size_t i = 0; i < 4; ++i) {
2900      FieldDecl *Field = FieldDecl::Create(*this,
2901                                           ObjCFastEnumerationStateTypeDecl,
2902                                           SourceLocation(), 0,
2903                                           FieldTypes[i], /*TInfo=*/0,
2904                                           /*BitWidth=*/0,
2905                                           /*Mutable=*/false);
2906      ObjCFastEnumerationStateTypeDecl->addDecl(Field);
2907    }
2908
2909    ObjCFastEnumerationStateTypeDecl->completeDefinition();
2910  }
2911
2912  return getTagDeclType(ObjCFastEnumerationStateTypeDecl);
2913}
2914
2915QualType ASTContext::getBlockDescriptorType() {
2916  if (BlockDescriptorType)
2917    return getTagDeclType(BlockDescriptorType);
2918
2919  RecordDecl *T;
2920  // FIXME: Needs the FlagAppleBlock bit.
2921  T = CreateRecordDecl(*this, TagDecl::TK_struct, TUDecl, SourceLocation(),
2922                       &Idents.get("__block_descriptor"));
2923  T->startDefinition();
2924
2925  QualType FieldTypes[] = {
2926    UnsignedLongTy,
2927    UnsignedLongTy,
2928  };
2929
2930  const char *FieldNames[] = {
2931    "reserved",
2932    "Size"
2933  };
2934
2935  for (size_t i = 0; i < 2; ++i) {
2936    FieldDecl *Field = FieldDecl::Create(*this,
2937                                         T,
2938                                         SourceLocation(),
2939                                         &Idents.get(FieldNames[i]),
2940                                         FieldTypes[i], /*TInfo=*/0,
2941                                         /*BitWidth=*/0,
2942                                         /*Mutable=*/false);
2943    T->addDecl(Field);
2944  }
2945
2946  T->completeDefinition();
2947
2948  BlockDescriptorType = T;
2949
2950  return getTagDeclType(BlockDescriptorType);
2951}
2952
2953void ASTContext::setBlockDescriptorType(QualType T) {
2954  const RecordType *Rec = T->getAs<RecordType>();
2955  assert(Rec && "Invalid BlockDescriptorType");
2956  BlockDescriptorType = Rec->getDecl();
2957}
2958
2959QualType ASTContext::getBlockDescriptorExtendedType() {
2960  if (BlockDescriptorExtendedType)
2961    return getTagDeclType(BlockDescriptorExtendedType);
2962
2963  RecordDecl *T;
2964  // FIXME: Needs the FlagAppleBlock bit.
2965  T = CreateRecordDecl(*this, TagDecl::TK_struct, TUDecl, SourceLocation(),
2966                       &Idents.get("__block_descriptor_withcopydispose"));
2967  T->startDefinition();
2968
2969  QualType FieldTypes[] = {
2970    UnsignedLongTy,
2971    UnsignedLongTy,
2972    getPointerType(VoidPtrTy),
2973    getPointerType(VoidPtrTy)
2974  };
2975
2976  const char *FieldNames[] = {
2977    "reserved",
2978    "Size",
2979    "CopyFuncPtr",
2980    "DestroyFuncPtr"
2981  };
2982
2983  for (size_t i = 0; i < 4; ++i) {
2984    FieldDecl *Field = FieldDecl::Create(*this,
2985                                         T,
2986                                         SourceLocation(),
2987                                         &Idents.get(FieldNames[i]),
2988                                         FieldTypes[i], /*TInfo=*/0,
2989                                         /*BitWidth=*/0,
2990                                         /*Mutable=*/false);
2991    T->addDecl(Field);
2992  }
2993
2994  T->completeDefinition();
2995
2996  BlockDescriptorExtendedType = T;
2997
2998  return getTagDeclType(BlockDescriptorExtendedType);
2999}
3000
3001void ASTContext::setBlockDescriptorExtendedType(QualType T) {
3002  const RecordType *Rec = T->getAs<RecordType>();
3003  assert(Rec && "Invalid BlockDescriptorType");
3004  BlockDescriptorExtendedType = Rec->getDecl();
3005}
3006
3007bool ASTContext::BlockRequiresCopying(QualType Ty) {
3008  if (Ty->isBlockPointerType())
3009    return true;
3010  if (isObjCNSObjectType(Ty))
3011    return true;
3012  if (Ty->isObjCObjectPointerType())
3013    return true;
3014  return false;
3015}
3016
3017QualType ASTContext::BuildByRefType(const char *DeclName, QualType Ty) {
3018  //  type = struct __Block_byref_1_X {
3019  //    void *__isa;
3020  //    struct __Block_byref_1_X *__forwarding;
3021  //    unsigned int __flags;
3022  //    unsigned int __size;
3023  //    void *__copy_helper;		// as needed
3024  //    void *__destroy_help		// as needed
3025  //    int X;
3026  //  } *
3027
3028  bool HasCopyAndDispose = BlockRequiresCopying(Ty);
3029
3030  // FIXME: Move up
3031  static unsigned int UniqueBlockByRefTypeID = 0;
3032  llvm::SmallString<36> Name;
3033  llvm::raw_svector_ostream(Name) << "__Block_byref_" <<
3034                                  ++UniqueBlockByRefTypeID << '_' << DeclName;
3035  RecordDecl *T;
3036  T = CreateRecordDecl(*this, TagDecl::TK_struct, TUDecl, SourceLocation(),
3037                       &Idents.get(Name.str()));
3038  T->startDefinition();
3039  QualType Int32Ty = IntTy;
3040  assert(getIntWidth(IntTy) == 32 && "non-32bit int not supported");
3041  QualType FieldTypes[] = {
3042    getPointerType(VoidPtrTy),
3043    getPointerType(getTagDeclType(T)),
3044    Int32Ty,
3045    Int32Ty,
3046    getPointerType(VoidPtrTy),
3047    getPointerType(VoidPtrTy),
3048    Ty
3049  };
3050
3051  const char *FieldNames[] = {
3052    "__isa",
3053    "__forwarding",
3054    "__flags",
3055    "__size",
3056    "__copy_helper",
3057    "__destroy_helper",
3058    DeclName,
3059  };
3060
3061  for (size_t i = 0; i < 7; ++i) {
3062    if (!HasCopyAndDispose && i >=4 && i <= 5)
3063      continue;
3064    FieldDecl *Field = FieldDecl::Create(*this, T, SourceLocation(),
3065                                         &Idents.get(FieldNames[i]),
3066                                         FieldTypes[i], /*TInfo=*/0,
3067                                         /*BitWidth=*/0, /*Mutable=*/false);
3068    T->addDecl(Field);
3069  }
3070
3071  T->completeDefinition();
3072
3073  return getPointerType(getTagDeclType(T));
3074}
3075
3076
3077QualType ASTContext::getBlockParmType(
3078  bool BlockHasCopyDispose,
3079  llvm::SmallVector<const Expr *, 8> &BlockDeclRefDecls) {
3080  // FIXME: Move up
3081  static unsigned int UniqueBlockParmTypeID = 0;
3082  llvm::SmallString<36> Name;
3083  llvm::raw_svector_ostream(Name) << "__block_literal_"
3084                                  << ++UniqueBlockParmTypeID;
3085  RecordDecl *T;
3086  T = CreateRecordDecl(*this, TagDecl::TK_struct, TUDecl, SourceLocation(),
3087                       &Idents.get(Name.str()));
3088  T->startDefinition();
3089  QualType FieldTypes[] = {
3090    getPointerType(VoidPtrTy),
3091    IntTy,
3092    IntTy,
3093    getPointerType(VoidPtrTy),
3094    (BlockHasCopyDispose ?
3095     getPointerType(getBlockDescriptorExtendedType()) :
3096     getPointerType(getBlockDescriptorType()))
3097  };
3098
3099  const char *FieldNames[] = {
3100    "__isa",
3101    "__flags",
3102    "__reserved",
3103    "__FuncPtr",
3104    "__descriptor"
3105  };
3106
3107  for (size_t i = 0; i < 5; ++i) {
3108    FieldDecl *Field = FieldDecl::Create(*this, T, SourceLocation(),
3109                                         &Idents.get(FieldNames[i]),
3110                                         FieldTypes[i], /*TInfo=*/0,
3111                                         /*BitWidth=*/0, /*Mutable=*/false);
3112    T->addDecl(Field);
3113  }
3114
3115  for (size_t i = 0; i < BlockDeclRefDecls.size(); ++i) {
3116    const Expr *E = BlockDeclRefDecls[i];
3117    const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E);
3118    clang::IdentifierInfo *Name = 0;
3119    if (BDRE) {
3120      const ValueDecl *D = BDRE->getDecl();
3121      Name = &Idents.get(D->getName());
3122    }
3123    QualType FieldType = E->getType();
3124
3125    if (BDRE && BDRE->isByRef())
3126      FieldType = BuildByRefType(BDRE->getDecl()->getNameAsCString(),
3127                                 FieldType);
3128
3129    FieldDecl *Field = FieldDecl::Create(*this, T, SourceLocation(),
3130                                         Name, FieldType, /*TInfo=*/0,
3131                                         /*BitWidth=*/0, /*Mutable=*/false);
3132    T->addDecl(Field);
3133  }
3134
3135  T->completeDefinition();
3136
3137  return getPointerType(getTagDeclType(T));
3138}
3139
3140void ASTContext::setObjCFastEnumerationStateType(QualType T) {
3141  const RecordType *Rec = T->getAs<RecordType>();
3142  assert(Rec && "Invalid ObjCFAstEnumerationStateType");
3143  ObjCFastEnumerationStateTypeDecl = Rec->getDecl();
3144}
3145
3146// This returns true if a type has been typedefed to BOOL:
3147// typedef <type> BOOL;
3148static bool isTypeTypedefedAsBOOL(QualType T) {
3149  if (const TypedefType *TT = dyn_cast<TypedefType>(T))
3150    if (IdentifierInfo *II = TT->getDecl()->getIdentifier())
3151      return II->isStr("BOOL");
3152
3153  return false;
3154}
3155
3156/// getObjCEncodingTypeSize returns size of type for objective-c encoding
3157/// purpose.
3158CharUnits ASTContext::getObjCEncodingTypeSize(QualType type) {
3159  CharUnits sz = getTypeSizeInChars(type);
3160
3161  // Make all integer and enum types at least as large as an int
3162  if (sz.isPositive() && type->isIntegralType())
3163    sz = std::max(sz, getTypeSizeInChars(IntTy));
3164  // Treat arrays as pointers, since that's how they're passed in.
3165  else if (type->isArrayType())
3166    sz = getTypeSizeInChars(VoidPtrTy);
3167  return sz;
3168}
3169
3170static inline
3171std::string charUnitsToString(const CharUnits &CU) {
3172  return llvm::itostr(CU.getQuantity());
3173}
3174
3175/// getObjCEncodingForBlockDecl - Return the encoded type for this method
3176/// declaration.
3177void ASTContext::getObjCEncodingForBlock(const BlockExpr *Expr,
3178                                             std::string& S) {
3179  const BlockDecl *Decl = Expr->getBlockDecl();
3180  QualType BlockTy =
3181      Expr->getType()->getAs<BlockPointerType>()->getPointeeType();
3182  // Encode result type.
3183  getObjCEncodingForType(cast<FunctionType>(BlockTy)->getResultType(), S);
3184  // Compute size of all parameters.
3185  // Start with computing size of a pointer in number of bytes.
3186  // FIXME: There might(should) be a better way of doing this computation!
3187  SourceLocation Loc;
3188  CharUnits PtrSize = getTypeSizeInChars(VoidPtrTy);
3189  CharUnits ParmOffset = PtrSize;
3190  for (ObjCMethodDecl::param_iterator PI = Decl->param_begin(),
3191       E = Decl->param_end(); PI != E; ++PI) {
3192    QualType PType = (*PI)->getType();
3193    CharUnits sz = getObjCEncodingTypeSize(PType);
3194    assert (sz.isPositive() && "BlockExpr - Incomplete param type");
3195    ParmOffset += sz;
3196  }
3197  // Size of the argument frame
3198  S += charUnitsToString(ParmOffset);
3199  // Block pointer and offset.
3200  S += "@?0";
3201  ParmOffset = PtrSize;
3202
3203  // Argument types.
3204  ParmOffset = PtrSize;
3205  for (BlockDecl::param_const_iterator PI = Decl->param_begin(), E =
3206       Decl->param_end(); PI != E; ++PI) {
3207    ParmVarDecl *PVDecl = *PI;
3208    QualType PType = PVDecl->getOriginalType();
3209    if (const ArrayType *AT =
3210          dyn_cast<ArrayType>(PType->getCanonicalTypeInternal())) {
3211      // Use array's original type only if it has known number of
3212      // elements.
3213      if (!isa<ConstantArrayType>(AT))
3214        PType = PVDecl->getType();
3215    } else if (PType->isFunctionType())
3216      PType = PVDecl->getType();
3217    getObjCEncodingForType(PType, S);
3218    S += charUnitsToString(ParmOffset);
3219    ParmOffset += getObjCEncodingTypeSize(PType);
3220  }
3221}
3222
3223/// getObjCEncodingForMethodDecl - Return the encoded type for this method
3224/// declaration.
3225void ASTContext::getObjCEncodingForMethodDecl(const ObjCMethodDecl *Decl,
3226                                              std::string& S) {
3227  // FIXME: This is not very efficient.
3228  // Encode type qualifer, 'in', 'inout', etc. for the return type.
3229  getObjCEncodingForTypeQualifier(Decl->getObjCDeclQualifier(), S);
3230  // Encode result type.
3231  getObjCEncodingForType(Decl->getResultType(), S);
3232  // Compute size of all parameters.
3233  // Start with computing size of a pointer in number of bytes.
3234  // FIXME: There might(should) be a better way of doing this computation!
3235  SourceLocation Loc;
3236  CharUnits PtrSize = getTypeSizeInChars(VoidPtrTy);
3237  // The first two arguments (self and _cmd) are pointers; account for
3238  // their size.
3239  CharUnits ParmOffset = 2 * PtrSize;
3240  for (ObjCMethodDecl::param_iterator PI = Decl->param_begin(),
3241       E = Decl->param_end(); PI != E; ++PI) {
3242    QualType PType = (*PI)->getType();
3243    CharUnits sz = getObjCEncodingTypeSize(PType);
3244    assert (sz.isPositive() &&
3245        "getObjCEncodingForMethodDecl - Incomplete param type");
3246    ParmOffset += sz;
3247  }
3248  S += charUnitsToString(ParmOffset);
3249  S += "@0:";
3250  S += charUnitsToString(PtrSize);
3251
3252  // Argument types.
3253  ParmOffset = 2 * PtrSize;
3254  for (ObjCMethodDecl::param_iterator PI = Decl->param_begin(),
3255       E = Decl->param_end(); PI != E; ++PI) {
3256    ParmVarDecl *PVDecl = *PI;
3257    QualType PType = PVDecl->getOriginalType();
3258    if (const ArrayType *AT =
3259          dyn_cast<ArrayType>(PType->getCanonicalTypeInternal())) {
3260      // Use array's original type only if it has known number of
3261      // elements.
3262      if (!isa<ConstantArrayType>(AT))
3263        PType = PVDecl->getType();
3264    } else if (PType->isFunctionType())
3265      PType = PVDecl->getType();
3266    // Process argument qualifiers for user supplied arguments; such as,
3267    // 'in', 'inout', etc.
3268    getObjCEncodingForTypeQualifier(PVDecl->getObjCDeclQualifier(), S);
3269    getObjCEncodingForType(PType, S);
3270    S += charUnitsToString(ParmOffset);
3271    ParmOffset += getObjCEncodingTypeSize(PType);
3272  }
3273}
3274
3275/// getObjCEncodingForPropertyDecl - Return the encoded type for this
3276/// property declaration. If non-NULL, Container must be either an
3277/// ObjCCategoryImplDecl or ObjCImplementationDecl; it should only be
3278/// NULL when getting encodings for protocol properties.
3279/// Property attributes are stored as a comma-delimited C string. The simple
3280/// attributes readonly and bycopy are encoded as single characters. The
3281/// parametrized attributes, getter=name, setter=name, and ivar=name, are
3282/// encoded as single characters, followed by an identifier. Property types
3283/// are also encoded as a parametrized attribute. The characters used to encode
3284/// these attributes are defined by the following enumeration:
3285/// @code
3286/// enum PropertyAttributes {
3287/// kPropertyReadOnly = 'R',   // property is read-only.
3288/// kPropertyBycopy = 'C',     // property is a copy of the value last assigned
3289/// kPropertyByref = '&',  // property is a reference to the value last assigned
3290/// kPropertyDynamic = 'D',    // property is dynamic
3291/// kPropertyGetter = 'G',     // followed by getter selector name
3292/// kPropertySetter = 'S',     // followed by setter selector name
3293/// kPropertyInstanceVariable = 'V'  // followed by instance variable  name
3294/// kPropertyType = 't'              // followed by old-style type encoding.
3295/// kPropertyWeak = 'W'              // 'weak' property
3296/// kPropertyStrong = 'P'            // property GC'able
3297/// kPropertyNonAtomic = 'N'         // property non-atomic
3298/// };
3299/// @endcode
3300void ASTContext::getObjCEncodingForPropertyDecl(const ObjCPropertyDecl *PD,
3301                                                const Decl *Container,
3302                                                std::string& S) {
3303  // Collect information from the property implementation decl(s).
3304  bool Dynamic = false;
3305  ObjCPropertyImplDecl *SynthesizePID = 0;
3306
3307  // FIXME: Duplicated code due to poor abstraction.
3308  if (Container) {
3309    if (const ObjCCategoryImplDecl *CID =
3310        dyn_cast<ObjCCategoryImplDecl>(Container)) {
3311      for (ObjCCategoryImplDecl::propimpl_iterator
3312             i = CID->propimpl_begin(), e = CID->propimpl_end();
3313           i != e; ++i) {
3314        ObjCPropertyImplDecl *PID = *i;
3315        if (PID->getPropertyDecl() == PD) {
3316          if (PID->getPropertyImplementation()==ObjCPropertyImplDecl::Dynamic) {
3317            Dynamic = true;
3318          } else {
3319            SynthesizePID = PID;
3320          }
3321        }
3322      }
3323    } else {
3324      const ObjCImplementationDecl *OID=cast<ObjCImplementationDecl>(Container);
3325      for (ObjCCategoryImplDecl::propimpl_iterator
3326             i = OID->propimpl_begin(), e = OID->propimpl_end();
3327           i != e; ++i) {
3328        ObjCPropertyImplDecl *PID = *i;
3329        if (PID->getPropertyDecl() == PD) {
3330          if (PID->getPropertyImplementation()==ObjCPropertyImplDecl::Dynamic) {
3331            Dynamic = true;
3332          } else {
3333            SynthesizePID = PID;
3334          }
3335        }
3336      }
3337    }
3338  }
3339
3340  // FIXME: This is not very efficient.
3341  S = "T";
3342
3343  // Encode result type.
3344  // GCC has some special rules regarding encoding of properties which
3345  // closely resembles encoding of ivars.
3346  getObjCEncodingForTypeImpl(PD->getType(), S, true, true, 0,
3347                             true /* outermost type */,
3348                             true /* encoding for property */);
3349
3350  if (PD->isReadOnly()) {
3351    S += ",R";
3352  } else {
3353    switch (PD->getSetterKind()) {
3354    case ObjCPropertyDecl::Assign: break;
3355    case ObjCPropertyDecl::Copy:   S += ",C"; break;
3356    case ObjCPropertyDecl::Retain: S += ",&"; break;
3357    }
3358  }
3359
3360  // It really isn't clear at all what this means, since properties
3361  // are "dynamic by default".
3362  if (Dynamic)
3363    S += ",D";
3364
3365  if (PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_nonatomic)
3366    S += ",N";
3367
3368  if (PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_getter) {
3369    S += ",G";
3370    S += PD->getGetterName().getAsString();
3371  }
3372
3373  if (PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_setter) {
3374    S += ",S";
3375    S += PD->getSetterName().getAsString();
3376  }
3377
3378  if (SynthesizePID) {
3379    const ObjCIvarDecl *OID = SynthesizePID->getPropertyIvarDecl();
3380    S += ",V";
3381    S += OID->getNameAsString();
3382  }
3383
3384  // FIXME: OBJCGC: weak & strong
3385}
3386
3387/// getLegacyIntegralTypeEncoding -
3388/// Another legacy compatibility encoding: 32-bit longs are encoded as
3389/// 'l' or 'L' , but not always.  For typedefs, we need to use
3390/// 'i' or 'I' instead if encoding a struct field, or a pointer!
3391///
3392void ASTContext::getLegacyIntegralTypeEncoding (QualType &PointeeTy) const {
3393  if (isa<TypedefType>(PointeeTy.getTypePtr())) {
3394    if (const BuiltinType *BT = PointeeTy->getAs<BuiltinType>()) {
3395      if (BT->getKind() == BuiltinType::ULong &&
3396          ((const_cast<ASTContext *>(this))->getIntWidth(PointeeTy) == 32))
3397        PointeeTy = UnsignedIntTy;
3398      else
3399        if (BT->getKind() == BuiltinType::Long &&
3400            ((const_cast<ASTContext *>(this))->getIntWidth(PointeeTy) == 32))
3401          PointeeTy = IntTy;
3402    }
3403  }
3404}
3405
3406void ASTContext::getObjCEncodingForType(QualType T, std::string& S,
3407                                        const FieldDecl *Field) {
3408  // We follow the behavior of gcc, expanding structures which are
3409  // directly pointed to, and expanding embedded structures. Note that
3410  // these rules are sufficient to prevent recursive encoding of the
3411  // same type.
3412  getObjCEncodingForTypeImpl(T, S, true, true, Field,
3413                             true /* outermost type */);
3414}
3415
3416static void EncodeBitField(const ASTContext *Context, std::string& S,
3417                           const FieldDecl *FD) {
3418  const Expr *E = FD->getBitWidth();
3419  assert(E && "bitfield width not there - getObjCEncodingForTypeImpl");
3420  ASTContext *Ctx = const_cast<ASTContext*>(Context);
3421  unsigned N = E->EvaluateAsInt(*Ctx).getZExtValue();
3422  S += 'b';
3423  S += llvm::utostr(N);
3424}
3425
3426// FIXME: Use SmallString for accumulating string.
3427void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string& S,
3428                                            bool ExpandPointedToStructures,
3429                                            bool ExpandStructures,
3430                                            const FieldDecl *FD,
3431                                            bool OutermostType,
3432                                            bool EncodingProperty) {
3433  if (const BuiltinType *BT = T->getAs<BuiltinType>()) {
3434    if (FD && FD->isBitField())
3435      return EncodeBitField(this, S, FD);
3436    char encoding;
3437    switch (BT->getKind()) {
3438    default: assert(0 && "Unhandled builtin type kind");
3439    case BuiltinType::Void:       encoding = 'v'; break;
3440    case BuiltinType::Bool:       encoding = 'B'; break;
3441    case BuiltinType::Char_U:
3442    case BuiltinType::UChar:      encoding = 'C'; break;
3443    case BuiltinType::UShort:     encoding = 'S'; break;
3444    case BuiltinType::UInt:       encoding = 'I'; break;
3445    case BuiltinType::ULong:
3446        encoding =
3447          (const_cast<ASTContext *>(this))->getIntWidth(T) == 32 ? 'L' : 'Q';
3448        break;
3449    case BuiltinType::UInt128:    encoding = 'T'; break;
3450    case BuiltinType::ULongLong:  encoding = 'Q'; break;
3451    case BuiltinType::Char_S:
3452    case BuiltinType::SChar:      encoding = 'c'; break;
3453    case BuiltinType::Short:      encoding = 's'; break;
3454    case BuiltinType::Int:        encoding = 'i'; break;
3455    case BuiltinType::Long:
3456      encoding =
3457        (const_cast<ASTContext *>(this))->getIntWidth(T) == 32 ? 'l' : 'q';
3458      break;
3459    case BuiltinType::LongLong:   encoding = 'q'; break;
3460    case BuiltinType::Int128:     encoding = 't'; break;
3461    case BuiltinType::Float:      encoding = 'f'; break;
3462    case BuiltinType::Double:     encoding = 'd'; break;
3463    case BuiltinType::LongDouble: encoding = 'd'; break;
3464    }
3465
3466    S += encoding;
3467    return;
3468  }
3469
3470  if (const ComplexType *CT = T->getAs<ComplexType>()) {
3471    S += 'j';
3472    getObjCEncodingForTypeImpl(CT->getElementType(), S, false, false, 0, false,
3473                               false);
3474    return;
3475  }
3476
3477  if (const PointerType *PT = T->getAs<PointerType>()) {
3478    if (PT->isObjCSelType()) {
3479      S += ':';
3480      return;
3481    }
3482    QualType PointeeTy = PT->getPointeeType();
3483
3484    bool isReadOnly = false;
3485    // For historical/compatibility reasons, the read-only qualifier of the
3486    // pointee gets emitted _before_ the '^'.  The read-only qualifier of
3487    // the pointer itself gets ignored, _unless_ we are looking at a typedef!
3488    // Also, do not emit the 'r' for anything but the outermost type!
3489    if (isa<TypedefType>(T.getTypePtr())) {
3490      if (OutermostType && T.isConstQualified()) {
3491        isReadOnly = true;
3492        S += 'r';
3493      }
3494    } else if (OutermostType) {
3495      QualType P = PointeeTy;
3496      while (P->getAs<PointerType>())
3497        P = P->getAs<PointerType>()->getPointeeType();
3498      if (P.isConstQualified()) {
3499        isReadOnly = true;
3500        S += 'r';
3501      }
3502    }
3503    if (isReadOnly) {
3504      // Another legacy compatibility encoding. Some ObjC qualifier and type
3505      // combinations need to be rearranged.
3506      // Rewrite "in const" from "nr" to "rn"
3507      const char * s = S.c_str();
3508      int len = S.length();
3509      if (len >= 2 && s[len-2] == 'n' && s[len-1] == 'r') {
3510        std::string replace = "rn";
3511        S.replace(S.end()-2, S.end(), replace);
3512      }
3513    }
3514
3515    if (PointeeTy->isCharType()) {
3516      // char pointer types should be encoded as '*' unless it is a
3517      // type that has been typedef'd to 'BOOL'.
3518      if (!isTypeTypedefedAsBOOL(PointeeTy)) {
3519        S += '*';
3520        return;
3521      }
3522    } else if (const RecordType *RTy = PointeeTy->getAs<RecordType>()) {
3523      // GCC binary compat: Need to convert "struct objc_class *" to "#".
3524      if (RTy->getDecl()->getIdentifier() == &Idents.get("objc_class")) {
3525        S += '#';
3526        return;
3527      }
3528      // GCC binary compat: Need to convert "struct objc_object *" to "@".
3529      if (RTy->getDecl()->getIdentifier() == &Idents.get("objc_object")) {
3530        S += '@';
3531        return;
3532      }
3533      // fall through...
3534    }
3535    S += '^';
3536    getLegacyIntegralTypeEncoding(PointeeTy);
3537
3538    getObjCEncodingForTypeImpl(PointeeTy, S, false, ExpandPointedToStructures,
3539                               NULL);
3540    return;
3541  }
3542
3543  if (const ArrayType *AT =
3544      // Ignore type qualifiers etc.
3545        dyn_cast<ArrayType>(T->getCanonicalTypeInternal())) {
3546    if (isa<IncompleteArrayType>(AT)) {
3547      // Incomplete arrays are encoded as a pointer to the array element.
3548      S += '^';
3549
3550      getObjCEncodingForTypeImpl(AT->getElementType(), S,
3551                                 false, ExpandStructures, FD);
3552    } else {
3553      S += '[';
3554
3555      if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
3556        S += llvm::utostr(CAT->getSize().getZExtValue());
3557      else {
3558        //Variable length arrays are encoded as a regular array with 0 elements.
3559        assert(isa<VariableArrayType>(AT) && "Unknown array type!");
3560        S += '0';
3561      }
3562
3563      getObjCEncodingForTypeImpl(AT->getElementType(), S,
3564                                 false, ExpandStructures, FD);
3565      S += ']';
3566    }
3567    return;
3568  }
3569
3570  if (T->getAs<FunctionType>()) {
3571    S += '?';
3572    return;
3573  }
3574
3575  if (const RecordType *RTy = T->getAs<RecordType>()) {
3576    RecordDecl *RDecl = RTy->getDecl();
3577    S += RDecl->isUnion() ? '(' : '{';
3578    // Anonymous structures print as '?'
3579    if (const IdentifierInfo *II = RDecl->getIdentifier()) {
3580      S += II->getName();
3581    } else {
3582      S += '?';
3583    }
3584    if (ExpandStructures) {
3585      S += '=';
3586      for (RecordDecl::field_iterator Field = RDecl->field_begin(),
3587                                   FieldEnd = RDecl->field_end();
3588           Field != FieldEnd; ++Field) {
3589        if (FD) {
3590          S += '"';
3591          S += Field->getNameAsString();
3592          S += '"';
3593        }
3594
3595        // Special case bit-fields.
3596        if (Field->isBitField()) {
3597          getObjCEncodingForTypeImpl(Field->getType(), S, false, true,
3598                                     (*Field));
3599        } else {
3600          QualType qt = Field->getType();
3601          getLegacyIntegralTypeEncoding(qt);
3602          getObjCEncodingForTypeImpl(qt, S, false, true,
3603                                     FD);
3604        }
3605      }
3606    }
3607    S += RDecl->isUnion() ? ')' : '}';
3608    return;
3609  }
3610
3611  if (T->isEnumeralType()) {
3612    if (FD && FD->isBitField())
3613      EncodeBitField(this, S, FD);
3614    else
3615      S += 'i';
3616    return;
3617  }
3618
3619  if (T->isBlockPointerType()) {
3620    S += "@?"; // Unlike a pointer-to-function, which is "^?".
3621    return;
3622  }
3623
3624  if (const ObjCInterfaceType *OIT = T->getAs<ObjCInterfaceType>()) {
3625    // @encode(class_name)
3626    ObjCInterfaceDecl *OI = OIT->getDecl();
3627    S += '{';
3628    const IdentifierInfo *II = OI->getIdentifier();
3629    S += II->getName();
3630    S += '=';
3631    llvm::SmallVector<FieldDecl*, 32> RecFields;
3632    CollectObjCIvars(OI, RecFields);
3633    for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
3634      if (RecFields[i]->isBitField())
3635        getObjCEncodingForTypeImpl(RecFields[i]->getType(), S, false, true,
3636                                   RecFields[i]);
3637      else
3638        getObjCEncodingForTypeImpl(RecFields[i]->getType(), S, false, true,
3639                                   FD);
3640    }
3641    S += '}';
3642    return;
3643  }
3644
3645  if (const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>()) {
3646    if (OPT->isObjCIdType()) {
3647      S += '@';
3648      return;
3649    }
3650
3651    if (OPT->isObjCClassType() || OPT->isObjCQualifiedClassType()) {
3652      // FIXME: Consider if we need to output qualifiers for 'Class<p>'.
3653      // Since this is a binary compatibility issue, need to consult with runtime
3654      // folks. Fortunately, this is a *very* obsure construct.
3655      S += '#';
3656      return;
3657    }
3658
3659    if (OPT->isObjCQualifiedIdType()) {
3660      getObjCEncodingForTypeImpl(getObjCIdType(), S,
3661                                 ExpandPointedToStructures,
3662                                 ExpandStructures, FD);
3663      if (FD || EncodingProperty) {
3664        // Note that we do extended encoding of protocol qualifer list
3665        // Only when doing ivar or property encoding.
3666        S += '"';
3667        for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
3668             E = OPT->qual_end(); I != E; ++I) {
3669          S += '<';
3670          S += (*I)->getNameAsString();
3671          S += '>';
3672        }
3673        S += '"';
3674      }
3675      return;
3676    }
3677
3678    QualType PointeeTy = OPT->getPointeeType();
3679    if (!EncodingProperty &&
3680        isa<TypedefType>(PointeeTy.getTypePtr())) {
3681      // Another historical/compatibility reason.
3682      // We encode the underlying type which comes out as
3683      // {...};
3684      S += '^';
3685      getObjCEncodingForTypeImpl(PointeeTy, S,
3686                                 false, ExpandPointedToStructures,
3687                                 NULL);
3688      return;
3689    }
3690
3691    S += '@';
3692    if (OPT->getInterfaceDecl() && (FD || EncodingProperty)) {
3693      S += '"';
3694      S += OPT->getInterfaceDecl()->getIdentifier()->getName();
3695      for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
3696           E = OPT->qual_end(); I != E; ++I) {
3697        S += '<';
3698        S += (*I)->getNameAsString();
3699        S += '>';
3700      }
3701      S += '"';
3702    }
3703    return;
3704  }
3705
3706  assert(0 && "@encode for type not implemented!");
3707}
3708
3709void ASTContext::getObjCEncodingForTypeQualifier(Decl::ObjCDeclQualifier QT,
3710                                                 std::string& S) const {
3711  if (QT & Decl::OBJC_TQ_In)
3712    S += 'n';
3713  if (QT & Decl::OBJC_TQ_Inout)
3714    S += 'N';
3715  if (QT & Decl::OBJC_TQ_Out)
3716    S += 'o';
3717  if (QT & Decl::OBJC_TQ_Bycopy)
3718    S += 'O';
3719  if (QT & Decl::OBJC_TQ_Byref)
3720    S += 'R';
3721  if (QT & Decl::OBJC_TQ_Oneway)
3722    S += 'V';
3723}
3724
3725void ASTContext::setBuiltinVaListType(QualType T) {
3726  assert(BuiltinVaListType.isNull() && "__builtin_va_list type already set!");
3727
3728  BuiltinVaListType = T;
3729}
3730
3731void ASTContext::setObjCIdType(QualType T) {
3732  ObjCIdTypedefType = T;
3733}
3734
3735void ASTContext::setObjCSelType(QualType T) {
3736  ObjCSelTypedefType = T;
3737}
3738
3739void ASTContext::setObjCProtoType(QualType QT) {
3740  ObjCProtoType = QT;
3741}
3742
3743void ASTContext::setObjCClassType(QualType T) {
3744  ObjCClassTypedefType = T;
3745}
3746
3747void ASTContext::setObjCConstantStringInterface(ObjCInterfaceDecl *Decl) {
3748  assert(ObjCConstantStringType.isNull() &&
3749         "'NSConstantString' type already set!");
3750
3751  ObjCConstantStringType = getObjCInterfaceType(Decl);
3752}
3753
3754/// \brief Retrieve the template name that corresponds to a non-empty
3755/// lookup.
3756TemplateName ASTContext::getOverloadedTemplateName(UnresolvedSetIterator Begin,
3757                                                   UnresolvedSetIterator End) {
3758  unsigned size = End - Begin;
3759  assert(size > 1 && "set is not overloaded!");
3760
3761  void *memory = Allocate(sizeof(OverloadedTemplateStorage) +
3762                          size * sizeof(FunctionTemplateDecl*));
3763  OverloadedTemplateStorage *OT = new(memory) OverloadedTemplateStorage(size);
3764
3765  NamedDecl **Storage = OT->getStorage();
3766  for (UnresolvedSetIterator I = Begin; I != End; ++I) {
3767    NamedDecl *D = *I;
3768    assert(isa<FunctionTemplateDecl>(D) ||
3769           (isa<UsingShadowDecl>(D) &&
3770            isa<FunctionTemplateDecl>(D->getUnderlyingDecl())));
3771    *Storage++ = D;
3772  }
3773
3774  return TemplateName(OT);
3775}
3776
3777/// \brief Retrieve the template name that represents a qualified
3778/// template name such as \c std::vector.
3779TemplateName ASTContext::getQualifiedTemplateName(NestedNameSpecifier *NNS,
3780                                                  bool TemplateKeyword,
3781                                                  TemplateDecl *Template) {
3782  // FIXME: Canonicalization?
3783  llvm::FoldingSetNodeID ID;
3784  QualifiedTemplateName::Profile(ID, NNS, TemplateKeyword, Template);
3785
3786  void *InsertPos = 0;
3787  QualifiedTemplateName *QTN =
3788    QualifiedTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
3789  if (!QTN) {
3790    QTN = new (*this,4) QualifiedTemplateName(NNS, TemplateKeyword, Template);
3791    QualifiedTemplateNames.InsertNode(QTN, InsertPos);
3792  }
3793
3794  return TemplateName(QTN);
3795}
3796
3797/// \brief Retrieve the template name that represents a dependent
3798/// template name such as \c MetaFun::template apply.
3799TemplateName ASTContext::getDependentTemplateName(NestedNameSpecifier *NNS,
3800                                                  const IdentifierInfo *Name) {
3801  assert((!NNS || NNS->isDependent()) &&
3802         "Nested name specifier must be dependent");
3803
3804  llvm::FoldingSetNodeID ID;
3805  DependentTemplateName::Profile(ID, NNS, Name);
3806
3807  void *InsertPos = 0;
3808  DependentTemplateName *QTN =
3809    DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
3810
3811  if (QTN)
3812    return TemplateName(QTN);
3813
3814  NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
3815  if (CanonNNS == NNS) {
3816    QTN = new (*this,4) DependentTemplateName(NNS, Name);
3817  } else {
3818    TemplateName Canon = getDependentTemplateName(CanonNNS, Name);
3819    QTN = new (*this,4) DependentTemplateName(NNS, Name, Canon);
3820    DependentTemplateName *CheckQTN =
3821      DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
3822    assert(!CheckQTN && "Dependent type name canonicalization broken");
3823    (void)CheckQTN;
3824  }
3825
3826  DependentTemplateNames.InsertNode(QTN, InsertPos);
3827  return TemplateName(QTN);
3828}
3829
3830/// \brief Retrieve the template name that represents a dependent
3831/// template name such as \c MetaFun::template operator+.
3832TemplateName
3833ASTContext::getDependentTemplateName(NestedNameSpecifier *NNS,
3834                                     OverloadedOperatorKind Operator) {
3835  assert((!NNS || NNS->isDependent()) &&
3836         "Nested name specifier must be dependent");
3837
3838  llvm::FoldingSetNodeID ID;
3839  DependentTemplateName::Profile(ID, NNS, Operator);
3840
3841  void *InsertPos = 0;
3842  DependentTemplateName *QTN
3843    = DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
3844
3845  if (QTN)
3846    return TemplateName(QTN);
3847
3848  NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
3849  if (CanonNNS == NNS) {
3850    QTN = new (*this,4) DependentTemplateName(NNS, Operator);
3851  } else {
3852    TemplateName Canon = getDependentTemplateName(CanonNNS, Operator);
3853    QTN = new (*this,4) DependentTemplateName(NNS, Operator, Canon);
3854
3855    DependentTemplateName *CheckQTN
3856      = DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
3857    assert(!CheckQTN && "Dependent template name canonicalization broken");
3858    (void)CheckQTN;
3859  }
3860
3861  DependentTemplateNames.InsertNode(QTN, InsertPos);
3862  return TemplateName(QTN);
3863}
3864
3865/// getFromTargetType - Given one of the integer types provided by
3866/// TargetInfo, produce the corresponding type. The unsigned @p Type
3867/// is actually a value of type @c TargetInfo::IntType.
3868CanQualType ASTContext::getFromTargetType(unsigned Type) const {
3869  switch (Type) {
3870  case TargetInfo::NoInt: return CanQualType();
3871  case TargetInfo::SignedShort: return ShortTy;
3872  case TargetInfo::UnsignedShort: return UnsignedShortTy;
3873  case TargetInfo::SignedInt: return IntTy;
3874  case TargetInfo::UnsignedInt: return UnsignedIntTy;
3875  case TargetInfo::SignedLong: return LongTy;
3876  case TargetInfo::UnsignedLong: return UnsignedLongTy;
3877  case TargetInfo::SignedLongLong: return LongLongTy;
3878  case TargetInfo::UnsignedLongLong: return UnsignedLongLongTy;
3879  }
3880
3881  assert(false && "Unhandled TargetInfo::IntType value");
3882  return CanQualType();
3883}
3884
3885//===----------------------------------------------------------------------===//
3886//                        Type Predicates.
3887//===----------------------------------------------------------------------===//
3888
3889/// isObjCNSObjectType - Return true if this is an NSObject object using
3890/// NSObject attribute on a c-style pointer type.
3891/// FIXME - Make it work directly on types.
3892/// FIXME: Move to Type.
3893///
3894bool ASTContext::isObjCNSObjectType(QualType Ty) const {
3895  if (TypedefType *TDT = dyn_cast<TypedefType>(Ty)) {
3896    if (TypedefDecl *TD = TDT->getDecl())
3897      if (TD->getAttr<ObjCNSObjectAttr>())
3898        return true;
3899  }
3900  return false;
3901}
3902
3903/// getObjCGCAttr - Returns one of GCNone, Weak or Strong objc's
3904/// garbage collection attribute.
3905///
3906Qualifiers::GC ASTContext::getObjCGCAttrKind(const QualType &Ty) const {
3907  Qualifiers::GC GCAttrs = Qualifiers::GCNone;
3908  if (getLangOptions().ObjC1 &&
3909      getLangOptions().getGCMode() != LangOptions::NonGC) {
3910    GCAttrs = Ty.getObjCGCAttr();
3911    // Default behavious under objective-c's gc is for objective-c pointers
3912    // (or pointers to them) be treated as though they were declared
3913    // as __strong.
3914    if (GCAttrs == Qualifiers::GCNone) {
3915      if (Ty->isObjCObjectPointerType() || Ty->isBlockPointerType())
3916        GCAttrs = Qualifiers::Strong;
3917      else if (Ty->isPointerType())
3918        return getObjCGCAttrKind(Ty->getAs<PointerType>()->getPointeeType());
3919    }
3920    // Non-pointers have none gc'able attribute regardless of the attribute
3921    // set on them.
3922    else if (!Ty->isAnyPointerType() && !Ty->isBlockPointerType())
3923      return Qualifiers::GCNone;
3924  }
3925  return GCAttrs;
3926}
3927
3928//===----------------------------------------------------------------------===//
3929//                        Type Compatibility Testing
3930//===----------------------------------------------------------------------===//
3931
3932/// areCompatVectorTypes - Return true if the two specified vector types are
3933/// compatible.
3934static bool areCompatVectorTypes(const VectorType *LHS,
3935                                 const VectorType *RHS) {
3936  assert(LHS->isCanonicalUnqualified() && RHS->isCanonicalUnqualified());
3937  return LHS->getElementType() == RHS->getElementType() &&
3938         LHS->getNumElements() == RHS->getNumElements();
3939}
3940
3941//===----------------------------------------------------------------------===//
3942// ObjCQualifiedIdTypesAreCompatible - Compatibility testing for qualified id's.
3943//===----------------------------------------------------------------------===//
3944
3945/// ProtocolCompatibleWithProtocol - return 'true' if 'lProto' is in the
3946/// inheritance hierarchy of 'rProto'.
3947bool ASTContext::ProtocolCompatibleWithProtocol(ObjCProtocolDecl *lProto,
3948                                                ObjCProtocolDecl *rProto) {
3949  if (lProto == rProto)
3950    return true;
3951  for (ObjCProtocolDecl::protocol_iterator PI = rProto->protocol_begin(),
3952       E = rProto->protocol_end(); PI != E; ++PI)
3953    if (ProtocolCompatibleWithProtocol(lProto, *PI))
3954      return true;
3955  return false;
3956}
3957
3958/// QualifiedIdConformsQualifiedId - compare id<p,...> with id<p1,...>
3959/// return true if lhs's protocols conform to rhs's protocol; false
3960/// otherwise.
3961bool ASTContext::QualifiedIdConformsQualifiedId(QualType lhs, QualType rhs) {
3962  if (lhs->isObjCQualifiedIdType() && rhs->isObjCQualifiedIdType())
3963    return ObjCQualifiedIdTypesAreCompatible(lhs, rhs, false);
3964  return false;
3965}
3966
3967/// ObjCQualifiedIdTypesAreCompatible - We know that one of lhs/rhs is an
3968/// ObjCQualifiedIDType.
3969bool ASTContext::ObjCQualifiedIdTypesAreCompatible(QualType lhs, QualType rhs,
3970                                                   bool compare) {
3971  // Allow id<P..> and an 'id' or void* type in all cases.
3972  if (lhs->isVoidPointerType() ||
3973      lhs->isObjCIdType() || lhs->isObjCClassType())
3974    return true;
3975  else if (rhs->isVoidPointerType() ||
3976           rhs->isObjCIdType() || rhs->isObjCClassType())
3977    return true;
3978
3979  if (const ObjCObjectPointerType *lhsQID = lhs->getAsObjCQualifiedIdType()) {
3980    const ObjCObjectPointerType *rhsOPT = rhs->getAs<ObjCObjectPointerType>();
3981
3982    if (!rhsOPT) return false;
3983
3984    if (rhsOPT->qual_empty()) {
3985      // If the RHS is a unqualified interface pointer "NSString*",
3986      // make sure we check the class hierarchy.
3987      if (ObjCInterfaceDecl *rhsID = rhsOPT->getInterfaceDecl()) {
3988        for (ObjCObjectPointerType::qual_iterator I = lhsQID->qual_begin(),
3989             E = lhsQID->qual_end(); I != E; ++I) {
3990          // when comparing an id<P> on lhs with a static type on rhs,
3991          // see if static class implements all of id's protocols, directly or
3992          // through its super class and categories.
3993          if (!rhsID->ClassImplementsProtocol(*I, true))
3994            return false;
3995        }
3996      }
3997      // If there are no qualifiers and no interface, we have an 'id'.
3998      return true;
3999    }
4000    // Both the right and left sides have qualifiers.
4001    for (ObjCObjectPointerType::qual_iterator I = lhsQID->qual_begin(),
4002         E = lhsQID->qual_end(); I != E; ++I) {
4003      ObjCProtocolDecl *lhsProto = *I;
4004      bool match = false;
4005
4006      // when comparing an id<P> on lhs with a static type on rhs,
4007      // see if static class implements all of id's protocols, directly or
4008      // through its super class and categories.
4009      for (ObjCObjectPointerType::qual_iterator J = rhsOPT->qual_begin(),
4010           E = rhsOPT->qual_end(); J != E; ++J) {
4011        ObjCProtocolDecl *rhsProto = *J;
4012        if (ProtocolCompatibleWithProtocol(lhsProto, rhsProto) ||
4013            (compare && ProtocolCompatibleWithProtocol(rhsProto, lhsProto))) {
4014          match = true;
4015          break;
4016        }
4017      }
4018      // If the RHS is a qualified interface pointer "NSString<P>*",
4019      // make sure we check the class hierarchy.
4020      if (ObjCInterfaceDecl *rhsID = rhsOPT->getInterfaceDecl()) {
4021        for (ObjCObjectPointerType::qual_iterator I = lhsQID->qual_begin(),
4022             E = lhsQID->qual_end(); I != E; ++I) {
4023          // when comparing an id<P> on lhs with a static type on rhs,
4024          // see if static class implements all of id's protocols, directly or
4025          // through its super class and categories.
4026          if (rhsID->ClassImplementsProtocol(*I, true)) {
4027            match = true;
4028            break;
4029          }
4030        }
4031      }
4032      if (!match)
4033        return false;
4034    }
4035
4036    return true;
4037  }
4038
4039  const ObjCObjectPointerType *rhsQID = rhs->getAsObjCQualifiedIdType();
4040  assert(rhsQID && "One of the LHS/RHS should be id<x>");
4041
4042  if (const ObjCObjectPointerType *lhsOPT =
4043        lhs->getAsObjCInterfacePointerType()) {
4044    if (lhsOPT->qual_empty()) {
4045      bool match = false;
4046      if (ObjCInterfaceDecl *lhsID = lhsOPT->getInterfaceDecl()) {
4047        for (ObjCObjectPointerType::qual_iterator I = rhsQID->qual_begin(),
4048             E = rhsQID->qual_end(); I != E; ++I) {
4049          // when comparing an id<P> on lhs with a static type on rhs,
4050          // see if static class implements all of id's protocols, directly or
4051          // through its super class and categories.
4052          if (lhsID->ClassImplementsProtocol(*I, true)) {
4053            match = true;
4054            break;
4055          }
4056        }
4057        if (!match)
4058          return false;
4059      }
4060      return true;
4061    }
4062    // Both the right and left sides have qualifiers.
4063    for (ObjCObjectPointerType::qual_iterator I = lhsOPT->qual_begin(),
4064         E = lhsOPT->qual_end(); I != E; ++I) {
4065      ObjCProtocolDecl *lhsProto = *I;
4066      bool match = false;
4067
4068      // when comparing an id<P> on lhs with a static type on rhs,
4069      // see if static class implements all of id's protocols, directly or
4070      // through its super class and categories.
4071      for (ObjCObjectPointerType::qual_iterator J = rhsQID->qual_begin(),
4072           E = rhsQID->qual_end(); J != E; ++J) {
4073        ObjCProtocolDecl *rhsProto = *J;
4074        if (ProtocolCompatibleWithProtocol(lhsProto, rhsProto) ||
4075            (compare && ProtocolCompatibleWithProtocol(rhsProto, lhsProto))) {
4076          match = true;
4077          break;
4078        }
4079      }
4080      if (!match)
4081        return false;
4082    }
4083    return true;
4084  }
4085  return false;
4086}
4087
4088/// canAssignObjCInterfaces - Return true if the two interface types are
4089/// compatible for assignment from RHS to LHS.  This handles validation of any
4090/// protocol qualifiers on the LHS or RHS.
4091///
4092bool ASTContext::canAssignObjCInterfaces(const ObjCObjectPointerType *LHSOPT,
4093                                         const ObjCObjectPointerType *RHSOPT) {
4094  // If either type represents the built-in 'id' or 'Class' types, return true.
4095  if (LHSOPT->isObjCBuiltinType() || RHSOPT->isObjCBuiltinType())
4096    return true;
4097
4098  if (LHSOPT->isObjCQualifiedIdType() || RHSOPT->isObjCQualifiedIdType())
4099    return ObjCQualifiedIdTypesAreCompatible(QualType(LHSOPT,0),
4100                                             QualType(RHSOPT,0),
4101                                             false);
4102
4103  const ObjCInterfaceType* LHS = LHSOPT->getInterfaceType();
4104  const ObjCInterfaceType* RHS = RHSOPT->getInterfaceType();
4105  if (LHS && RHS) // We have 2 user-defined types.
4106    return canAssignObjCInterfaces(LHS, RHS);
4107
4108  return false;
4109}
4110
4111/// canAssignObjCInterfacesInBlockPointer - This routine is specifically written
4112/// for providing type-safty for objective-c pointers used to pass/return
4113/// arguments in block literals. When passed as arguments, passing 'A*' where
4114/// 'id' is expected is not OK. Passing 'Sub *" where 'Super *" is expected is
4115/// not OK. For the return type, the opposite is not OK.
4116bool ASTContext::canAssignObjCInterfacesInBlockPointer(
4117                                         const ObjCObjectPointerType *LHSOPT,
4118                                         const ObjCObjectPointerType *RHSOPT) {
4119  if (RHSOPT->isObjCBuiltinType())
4120    return true;
4121
4122  if (LHSOPT->isObjCBuiltinType()) {
4123    return RHSOPT->isObjCBuiltinType() || RHSOPT->isObjCQualifiedIdType();
4124  }
4125
4126  if (LHSOPT->isObjCQualifiedIdType() || RHSOPT->isObjCQualifiedIdType())
4127    return ObjCQualifiedIdTypesAreCompatible(QualType(LHSOPT,0),
4128                                             QualType(RHSOPT,0),
4129                                             false);
4130
4131  const ObjCInterfaceType* LHS = LHSOPT->getInterfaceType();
4132  const ObjCInterfaceType* RHS = RHSOPT->getInterfaceType();
4133  if (LHS && RHS)  { // We have 2 user-defined types.
4134    if (LHS != RHS) {
4135      if (LHS->getDecl()->isSuperClassOf(RHS->getDecl()))
4136        return false;
4137      if (RHS->getDecl()->isSuperClassOf(LHS->getDecl()))
4138        return true;
4139    }
4140    else
4141      return true;
4142  }
4143  return false;
4144}
4145
4146/// getIntersectionOfProtocols - This routine finds the intersection of set
4147/// of protocols inherited from two distinct objective-c pointer objects.
4148/// It is used to build composite qualifier list of the composite type of
4149/// the conditional expression involving two objective-c pointer objects.
4150static
4151void getIntersectionOfProtocols(ASTContext &Context,
4152                                const ObjCObjectPointerType *LHSOPT,
4153                                const ObjCObjectPointerType *RHSOPT,
4154      llvm::SmallVectorImpl<ObjCProtocolDecl *> &IntersectionOfProtocols) {
4155
4156  const ObjCInterfaceType* LHS = LHSOPT->getInterfaceType();
4157  const ObjCInterfaceType* RHS = RHSOPT->getInterfaceType();
4158
4159  llvm::SmallPtrSet<ObjCProtocolDecl *, 8> InheritedProtocolSet;
4160  unsigned LHSNumProtocols = LHS->getNumProtocols();
4161  if (LHSNumProtocols > 0)
4162    InheritedProtocolSet.insert(LHS->qual_begin(), LHS->qual_end());
4163  else {
4164    llvm::SmallPtrSet<ObjCProtocolDecl *, 8> LHSInheritedProtocols;
4165    Context.CollectInheritedProtocols(LHS->getDecl(), LHSInheritedProtocols);
4166    InheritedProtocolSet.insert(LHSInheritedProtocols.begin(),
4167                                LHSInheritedProtocols.end());
4168  }
4169
4170  unsigned RHSNumProtocols = RHS->getNumProtocols();
4171  if (RHSNumProtocols > 0) {
4172    ObjCProtocolDecl **RHSProtocols = (ObjCProtocolDecl **)RHS->qual_begin();
4173    for (unsigned i = 0; i < RHSNumProtocols; ++i)
4174      if (InheritedProtocolSet.count(RHSProtocols[i]))
4175        IntersectionOfProtocols.push_back(RHSProtocols[i]);
4176  }
4177  else {
4178    llvm::SmallPtrSet<ObjCProtocolDecl *, 8> RHSInheritedProtocols;
4179    Context.CollectInheritedProtocols(RHS->getDecl(), RHSInheritedProtocols);
4180    for (llvm::SmallPtrSet<ObjCProtocolDecl*,8>::iterator I =
4181         RHSInheritedProtocols.begin(),
4182         E = RHSInheritedProtocols.end(); I != E; ++I)
4183      if (InheritedProtocolSet.count((*I)))
4184        IntersectionOfProtocols.push_back((*I));
4185  }
4186}
4187
4188/// areCommonBaseCompatible - Returns common base class of the two classes if
4189/// one found. Note that this is O'2 algorithm. But it will be called as the
4190/// last type comparison in a ?-exp of ObjC pointer types before a
4191/// warning is issued. So, its invokation is extremely rare.
4192QualType ASTContext::areCommonBaseCompatible(
4193                                          const ObjCObjectPointerType *LHSOPT,
4194                                          const ObjCObjectPointerType *RHSOPT) {
4195  const ObjCInterfaceType* LHS = LHSOPT->getInterfaceType();
4196  const ObjCInterfaceType* RHS = RHSOPT->getInterfaceType();
4197  if (!LHS || !RHS)
4198    return QualType();
4199
4200  while (const ObjCInterfaceDecl *LHSIDecl = LHS->getDecl()->getSuperClass()) {
4201    QualType LHSTy = getObjCInterfaceType(LHSIDecl);
4202    LHS = LHSTy->getAs<ObjCInterfaceType>();
4203    if (canAssignObjCInterfaces(LHS, RHS)) {
4204      llvm::SmallVector<ObjCProtocolDecl *, 8> IntersectionOfProtocols;
4205      getIntersectionOfProtocols(*this,
4206                                 LHSOPT, RHSOPT, IntersectionOfProtocols);
4207      if (IntersectionOfProtocols.empty())
4208        LHSTy = getObjCObjectPointerType(LHSTy);
4209      else
4210        LHSTy = getObjCObjectPointerType(LHSTy, &IntersectionOfProtocols[0],
4211                                                IntersectionOfProtocols.size());
4212      return LHSTy;
4213    }
4214  }
4215
4216  return QualType();
4217}
4218
4219bool ASTContext::canAssignObjCInterfaces(const ObjCInterfaceType *LHS,
4220                                         const ObjCInterfaceType *RHS) {
4221  // Verify that the base decls are compatible: the RHS must be a subclass of
4222  // the LHS.
4223  if (!LHS->getDecl()->isSuperClassOf(RHS->getDecl()))
4224    return false;
4225
4226  // RHS must have a superset of the protocols in the LHS.  If the LHS is not
4227  // protocol qualified at all, then we are good.
4228  if (LHS->getNumProtocols() == 0)
4229    return true;
4230
4231  // Okay, we know the LHS has protocol qualifiers.  If the RHS doesn't, then it
4232  // isn't a superset.
4233  if (RHS->getNumProtocols() == 0)
4234    return true;  // FIXME: should return false!
4235
4236  for (ObjCInterfaceType::qual_iterator LHSPI = LHS->qual_begin(),
4237                                        LHSPE = LHS->qual_end();
4238       LHSPI != LHSPE; LHSPI++) {
4239    bool RHSImplementsProtocol = false;
4240
4241    // If the RHS doesn't implement the protocol on the left, the types
4242    // are incompatible.
4243    for (ObjCInterfaceType::qual_iterator RHSPI = RHS->qual_begin(),
4244                                          RHSPE = RHS->qual_end();
4245         RHSPI != RHSPE; RHSPI++) {
4246      if ((*RHSPI)->lookupProtocolNamed((*LHSPI)->getIdentifier())) {
4247        RHSImplementsProtocol = true;
4248        break;
4249      }
4250    }
4251    // FIXME: For better diagnostics, consider passing back the protocol name.
4252    if (!RHSImplementsProtocol)
4253      return false;
4254  }
4255  // The RHS implements all protocols listed on the LHS.
4256  return true;
4257}
4258
4259bool ASTContext::areComparableObjCPointerTypes(QualType LHS, QualType RHS) {
4260  // get the "pointed to" types
4261  const ObjCObjectPointerType *LHSOPT = LHS->getAs<ObjCObjectPointerType>();
4262  const ObjCObjectPointerType *RHSOPT = RHS->getAs<ObjCObjectPointerType>();
4263
4264  if (!LHSOPT || !RHSOPT)
4265    return false;
4266
4267  return canAssignObjCInterfaces(LHSOPT, RHSOPT) ||
4268         canAssignObjCInterfaces(RHSOPT, LHSOPT);
4269}
4270
4271/// typesAreCompatible - C99 6.7.3p9: For two qualified types to be compatible,
4272/// both shall have the identically qualified version of a compatible type.
4273/// C99 6.2.7p1: Two types have compatible types if their types are the
4274/// same. See 6.7.[2,3,5] for additional rules.
4275bool ASTContext::typesAreCompatible(QualType LHS, QualType RHS) {
4276  if (getLangOptions().CPlusPlus)
4277    return hasSameType(LHS, RHS);
4278
4279  return !mergeTypes(LHS, RHS).isNull();
4280}
4281
4282bool ASTContext::typesAreBlockPointerCompatible(QualType LHS, QualType RHS) {
4283  return !mergeTypes(LHS, RHS, true).isNull();
4284}
4285
4286QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
4287                                        bool OfBlockPointer) {
4288  const FunctionType *lbase = lhs->getAs<FunctionType>();
4289  const FunctionType *rbase = rhs->getAs<FunctionType>();
4290  const FunctionProtoType *lproto = dyn_cast<FunctionProtoType>(lbase);
4291  const FunctionProtoType *rproto = dyn_cast<FunctionProtoType>(rbase);
4292  bool allLTypes = true;
4293  bool allRTypes = true;
4294
4295  // Check return type
4296  QualType retType;
4297  if (OfBlockPointer)
4298    retType = mergeTypes(rbase->getResultType(), lbase->getResultType(), true);
4299  else
4300   retType = mergeTypes(lbase->getResultType(), rbase->getResultType());
4301  if (retType.isNull()) return QualType();
4302  if (getCanonicalType(retType) != getCanonicalType(lbase->getResultType()))
4303    allLTypes = false;
4304  if (getCanonicalType(retType) != getCanonicalType(rbase->getResultType()))
4305    allRTypes = false;
4306  // FIXME: double check this
4307  bool NoReturn = lbase->getNoReturnAttr() || rbase->getNoReturnAttr();
4308  if (NoReturn != lbase->getNoReturnAttr())
4309    allLTypes = false;
4310  if (NoReturn != rbase->getNoReturnAttr())
4311    allRTypes = false;
4312  CallingConv lcc = lbase->getCallConv();
4313  CallingConv rcc = rbase->getCallConv();
4314  // Compatible functions must have compatible calling conventions
4315  if (!isSameCallConv(lcc, rcc))
4316    return QualType();
4317
4318  if (lproto && rproto) { // two C99 style function prototypes
4319    assert(!lproto->hasExceptionSpec() && !rproto->hasExceptionSpec() &&
4320           "C++ shouldn't be here");
4321    unsigned lproto_nargs = lproto->getNumArgs();
4322    unsigned rproto_nargs = rproto->getNumArgs();
4323
4324    // Compatible functions must have the same number of arguments
4325    if (lproto_nargs != rproto_nargs)
4326      return QualType();
4327
4328    // Variadic and non-variadic functions aren't compatible
4329    if (lproto->isVariadic() != rproto->isVariadic())
4330      return QualType();
4331
4332    if (lproto->getTypeQuals() != rproto->getTypeQuals())
4333      return QualType();
4334
4335    // Check argument compatibility
4336    llvm::SmallVector<QualType, 10> types;
4337    for (unsigned i = 0; i < lproto_nargs; i++) {
4338      QualType largtype = lproto->getArgType(i).getUnqualifiedType();
4339      QualType rargtype = rproto->getArgType(i).getUnqualifiedType();
4340      QualType argtype = mergeTypes(largtype, rargtype, OfBlockPointer);
4341      if (argtype.isNull()) return QualType();
4342      types.push_back(argtype);
4343      if (getCanonicalType(argtype) != getCanonicalType(largtype))
4344        allLTypes = false;
4345      if (getCanonicalType(argtype) != getCanonicalType(rargtype))
4346        allRTypes = false;
4347    }
4348    if (allLTypes) return lhs;
4349    if (allRTypes) return rhs;
4350    return getFunctionType(retType, types.begin(), types.size(),
4351                           lproto->isVariadic(), lproto->getTypeQuals(),
4352                           false, false, 0, 0, NoReturn, lcc);
4353  }
4354
4355  if (lproto) allRTypes = false;
4356  if (rproto) allLTypes = false;
4357
4358  const FunctionProtoType *proto = lproto ? lproto : rproto;
4359  if (proto) {
4360    assert(!proto->hasExceptionSpec() && "C++ shouldn't be here");
4361    if (proto->isVariadic()) return QualType();
4362    // Check that the types are compatible with the types that
4363    // would result from default argument promotions (C99 6.7.5.3p15).
4364    // The only types actually affected are promotable integer
4365    // types and floats, which would be passed as a different
4366    // type depending on whether the prototype is visible.
4367    unsigned proto_nargs = proto->getNumArgs();
4368    for (unsigned i = 0; i < proto_nargs; ++i) {
4369      QualType argTy = proto->getArgType(i);
4370
4371      // Look at the promotion type of enum types, since that is the type used
4372      // to pass enum values.
4373      if (const EnumType *Enum = argTy->getAs<EnumType>())
4374        argTy = Enum->getDecl()->getPromotionType();
4375
4376      if (argTy->isPromotableIntegerType() ||
4377          getCanonicalType(argTy).getUnqualifiedType() == FloatTy)
4378        return QualType();
4379    }
4380
4381    if (allLTypes) return lhs;
4382    if (allRTypes) return rhs;
4383    return getFunctionType(retType, proto->arg_type_begin(),
4384                           proto->getNumArgs(), proto->isVariadic(),
4385                           proto->getTypeQuals(),
4386                           false, false, 0, 0, NoReturn, lcc);
4387  }
4388
4389  if (allLTypes) return lhs;
4390  if (allRTypes) return rhs;
4391  return getFunctionNoProtoType(retType, NoReturn, lcc);
4392}
4393
4394QualType ASTContext::mergeTypes(QualType LHS, QualType RHS,
4395                                bool OfBlockPointer) {
4396  // C++ [expr]: If an expression initially has the type "reference to T", the
4397  // type is adjusted to "T" prior to any further analysis, the expression
4398  // designates the object or function denoted by the reference, and the
4399  // expression is an lvalue unless the reference is an rvalue reference and
4400  // the expression is a function call (possibly inside parentheses).
4401  assert(!LHS->getAs<ReferenceType>() && "LHS is a reference type?");
4402  assert(!RHS->getAs<ReferenceType>() && "RHS is a reference type?");
4403
4404  QualType LHSCan = getCanonicalType(LHS),
4405           RHSCan = getCanonicalType(RHS);
4406
4407  // If two types are identical, they are compatible.
4408  if (LHSCan == RHSCan)
4409    return LHS;
4410
4411  // If the qualifiers are different, the types aren't compatible... mostly.
4412  Qualifiers LQuals = LHSCan.getLocalQualifiers();
4413  Qualifiers RQuals = RHSCan.getLocalQualifiers();
4414  if (LQuals != RQuals) {
4415    // If any of these qualifiers are different, we have a type
4416    // mismatch.
4417    if (LQuals.getCVRQualifiers() != RQuals.getCVRQualifiers() ||
4418        LQuals.getAddressSpace() != RQuals.getAddressSpace())
4419      return QualType();
4420
4421    // Exactly one GC qualifier difference is allowed: __strong is
4422    // okay if the other type has no GC qualifier but is an Objective
4423    // C object pointer (i.e. implicitly strong by default).  We fix
4424    // this by pretending that the unqualified type was actually
4425    // qualified __strong.
4426    Qualifiers::GC GC_L = LQuals.getObjCGCAttr();
4427    Qualifiers::GC GC_R = RQuals.getObjCGCAttr();
4428    assert((GC_L != GC_R) && "unequal qualifier sets had only equal elements");
4429
4430    if (GC_L == Qualifiers::Weak || GC_R == Qualifiers::Weak)
4431      return QualType();
4432
4433    if (GC_L == Qualifiers::Strong && RHSCan->isObjCObjectPointerType()) {
4434      return mergeTypes(LHS, getObjCGCQualType(RHS, Qualifiers::Strong));
4435    }
4436    if (GC_R == Qualifiers::Strong && LHSCan->isObjCObjectPointerType()) {
4437      return mergeTypes(getObjCGCQualType(LHS, Qualifiers::Strong), RHS);
4438    }
4439    return QualType();
4440  }
4441
4442  // Okay, qualifiers are equal.
4443
4444  Type::TypeClass LHSClass = LHSCan->getTypeClass();
4445  Type::TypeClass RHSClass = RHSCan->getTypeClass();
4446
4447  // We want to consider the two function types to be the same for these
4448  // comparisons, just force one to the other.
4449  if (LHSClass == Type::FunctionProto) LHSClass = Type::FunctionNoProto;
4450  if (RHSClass == Type::FunctionProto) RHSClass = Type::FunctionNoProto;
4451
4452  // Same as above for arrays
4453  if (LHSClass == Type::VariableArray || LHSClass == Type::IncompleteArray)
4454    LHSClass = Type::ConstantArray;
4455  if (RHSClass == Type::VariableArray || RHSClass == Type::IncompleteArray)
4456    RHSClass = Type::ConstantArray;
4457
4458  // Canonicalize ExtVector -> Vector.
4459  if (LHSClass == Type::ExtVector) LHSClass = Type::Vector;
4460  if (RHSClass == Type::ExtVector) RHSClass = Type::Vector;
4461
4462  // If the canonical type classes don't match.
4463  if (LHSClass != RHSClass) {
4464    // C99 6.7.2.2p4: Each enumerated type shall be compatible with char,
4465    // a signed integer type, or an unsigned integer type.
4466    // Compatibility is based on the underlying type, not the promotion
4467    // type.
4468    if (const EnumType* ETy = LHS->getAs<EnumType>()) {
4469      if (ETy->getDecl()->getIntegerType() == RHSCan.getUnqualifiedType())
4470        return RHS;
4471    }
4472    if (const EnumType* ETy = RHS->getAs<EnumType>()) {
4473      if (ETy->getDecl()->getIntegerType() == LHSCan.getUnqualifiedType())
4474        return LHS;
4475    }
4476
4477    return QualType();
4478  }
4479
4480  // The canonical type classes match.
4481  switch (LHSClass) {
4482#define TYPE(Class, Base)
4483#define ABSTRACT_TYPE(Class, Base)
4484#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
4485#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
4486#define DEPENDENT_TYPE(Class, Base) case Type::Class:
4487#include "clang/AST/TypeNodes.def"
4488    assert(false && "Non-canonical and dependent types shouldn't get here");
4489    return QualType();
4490
4491  case Type::LValueReference:
4492  case Type::RValueReference:
4493  case Type::MemberPointer:
4494    assert(false && "C++ should never be in mergeTypes");
4495    return QualType();
4496
4497  case Type::IncompleteArray:
4498  case Type::VariableArray:
4499  case Type::FunctionProto:
4500  case Type::ExtVector:
4501    assert(false && "Types are eliminated above");
4502    return QualType();
4503
4504  case Type::Pointer:
4505  {
4506    // Merge two pointer types, while trying to preserve typedef info
4507    QualType LHSPointee = LHS->getAs<PointerType>()->getPointeeType();
4508    QualType RHSPointee = RHS->getAs<PointerType>()->getPointeeType();
4509    QualType ResultType = mergeTypes(LHSPointee, RHSPointee);
4510    if (ResultType.isNull()) return QualType();
4511    if (getCanonicalType(LHSPointee) == getCanonicalType(ResultType))
4512      return LHS;
4513    if (getCanonicalType(RHSPointee) == getCanonicalType(ResultType))
4514      return RHS;
4515    return getPointerType(ResultType);
4516  }
4517  case Type::BlockPointer:
4518  {
4519    // Merge two block pointer types, while trying to preserve typedef info
4520    QualType LHSPointee = LHS->getAs<BlockPointerType>()->getPointeeType();
4521    QualType RHSPointee = RHS->getAs<BlockPointerType>()->getPointeeType();
4522    QualType ResultType = mergeTypes(LHSPointee, RHSPointee, OfBlockPointer);
4523    if (ResultType.isNull()) return QualType();
4524    if (getCanonicalType(LHSPointee) == getCanonicalType(ResultType))
4525      return LHS;
4526    if (getCanonicalType(RHSPointee) == getCanonicalType(ResultType))
4527      return RHS;
4528    return getBlockPointerType(ResultType);
4529  }
4530  case Type::ConstantArray:
4531  {
4532    const ConstantArrayType* LCAT = getAsConstantArrayType(LHS);
4533    const ConstantArrayType* RCAT = getAsConstantArrayType(RHS);
4534    if (LCAT && RCAT && RCAT->getSize() != LCAT->getSize())
4535      return QualType();
4536
4537    QualType LHSElem = getAsArrayType(LHS)->getElementType();
4538    QualType RHSElem = getAsArrayType(RHS)->getElementType();
4539    QualType ResultType = mergeTypes(LHSElem, RHSElem);
4540    if (ResultType.isNull()) return QualType();
4541    if (LCAT && getCanonicalType(LHSElem) == getCanonicalType(ResultType))
4542      return LHS;
4543    if (RCAT && getCanonicalType(RHSElem) == getCanonicalType(ResultType))
4544      return RHS;
4545    if (LCAT) return getConstantArrayType(ResultType, LCAT->getSize(),
4546                                          ArrayType::ArraySizeModifier(), 0);
4547    if (RCAT) return getConstantArrayType(ResultType, RCAT->getSize(),
4548                                          ArrayType::ArraySizeModifier(), 0);
4549    const VariableArrayType* LVAT = getAsVariableArrayType(LHS);
4550    const VariableArrayType* RVAT = getAsVariableArrayType(RHS);
4551    if (LVAT && getCanonicalType(LHSElem) == getCanonicalType(ResultType))
4552      return LHS;
4553    if (RVAT && getCanonicalType(RHSElem) == getCanonicalType(ResultType))
4554      return RHS;
4555    if (LVAT) {
4556      // FIXME: This isn't correct! But tricky to implement because
4557      // the array's size has to be the size of LHS, but the type
4558      // has to be different.
4559      return LHS;
4560    }
4561    if (RVAT) {
4562      // FIXME: This isn't correct! But tricky to implement because
4563      // the array's size has to be the size of RHS, but the type
4564      // has to be different.
4565      return RHS;
4566    }
4567    if (getCanonicalType(LHSElem) == getCanonicalType(ResultType)) return LHS;
4568    if (getCanonicalType(RHSElem) == getCanonicalType(ResultType)) return RHS;
4569    return getIncompleteArrayType(ResultType,
4570                                  ArrayType::ArraySizeModifier(), 0);
4571  }
4572  case Type::FunctionNoProto:
4573    return mergeFunctionTypes(LHS, RHS, OfBlockPointer);
4574  case Type::Record:
4575  case Type::Enum:
4576    return QualType();
4577  case Type::Builtin:
4578    // Only exactly equal builtin types are compatible, which is tested above.
4579    return QualType();
4580  case Type::Complex:
4581    // Distinct complex types are incompatible.
4582    return QualType();
4583  case Type::Vector:
4584    // FIXME: The merged type should be an ExtVector!
4585    if (areCompatVectorTypes(LHSCan->getAs<VectorType>(),
4586                             RHSCan->getAs<VectorType>()))
4587      return LHS;
4588    return QualType();
4589  case Type::ObjCInterface: {
4590    // Check if the interfaces are assignment compatible.
4591    // FIXME: This should be type compatibility, e.g. whether
4592    // "LHS x; RHS x;" at global scope is legal.
4593    const ObjCInterfaceType* LHSIface = LHS->getAs<ObjCInterfaceType>();
4594    const ObjCInterfaceType* RHSIface = RHS->getAs<ObjCInterfaceType>();
4595    if (LHSIface && RHSIface &&
4596        canAssignObjCInterfaces(LHSIface, RHSIface))
4597      return LHS;
4598
4599    return QualType();
4600  }
4601  case Type::ObjCObjectPointer: {
4602    if (OfBlockPointer) {
4603      if (canAssignObjCInterfacesInBlockPointer(
4604                                          LHS->getAs<ObjCObjectPointerType>(),
4605                                          RHS->getAs<ObjCObjectPointerType>()))
4606      return LHS;
4607      return QualType();
4608    }
4609    if (canAssignObjCInterfaces(LHS->getAs<ObjCObjectPointerType>(),
4610                                RHS->getAs<ObjCObjectPointerType>()))
4611      return LHS;
4612
4613    return QualType();
4614    }
4615  }
4616
4617  return QualType();
4618}
4619
4620//===----------------------------------------------------------------------===//
4621//                         Integer Predicates
4622//===----------------------------------------------------------------------===//
4623
4624unsigned ASTContext::getIntWidth(QualType T) {
4625  if (T->isBooleanType())
4626    return 1;
4627  if (EnumType *ET = dyn_cast<EnumType>(T))
4628    T = ET->getDecl()->getIntegerType();
4629  // For builtin types, just use the standard type sizing method
4630  return (unsigned)getTypeSize(T);
4631}
4632
4633QualType ASTContext::getCorrespondingUnsignedType(QualType T) {
4634  assert(T->isSignedIntegerType() && "Unexpected type");
4635
4636  // Turn <4 x signed int> -> <4 x unsigned int>
4637  if (const VectorType *VTy = T->getAs<VectorType>())
4638    return getVectorType(getCorrespondingUnsignedType(VTy->getElementType()),
4639             VTy->getNumElements(), VTy->isAltiVec(), VTy->isPixel());
4640
4641  // For enums, we return the unsigned version of the base type.
4642  if (const EnumType *ETy = T->getAs<EnumType>())
4643    T = ETy->getDecl()->getIntegerType();
4644
4645  const BuiltinType *BTy = T->getAs<BuiltinType>();
4646  assert(BTy && "Unexpected signed integer type");
4647  switch (BTy->getKind()) {
4648  case BuiltinType::Char_S:
4649  case BuiltinType::SChar:
4650    return UnsignedCharTy;
4651  case BuiltinType::Short:
4652    return UnsignedShortTy;
4653  case BuiltinType::Int:
4654    return UnsignedIntTy;
4655  case BuiltinType::Long:
4656    return UnsignedLongTy;
4657  case BuiltinType::LongLong:
4658    return UnsignedLongLongTy;
4659  case BuiltinType::Int128:
4660    return UnsignedInt128Ty;
4661  default:
4662    assert(0 && "Unexpected signed integer type");
4663    return QualType();
4664  }
4665}
4666
4667ExternalASTSource::~ExternalASTSource() { }
4668
4669void ExternalASTSource::PrintStats() { }
4670
4671
4672//===----------------------------------------------------------------------===//
4673//                          Builtin Type Computation
4674//===----------------------------------------------------------------------===//
4675
4676/// DecodeTypeFromStr - This decodes one type descriptor from Str, advancing the
4677/// pointer over the consumed characters.  This returns the resultant type.
4678static QualType DecodeTypeFromStr(const char *&Str, ASTContext &Context,
4679                                  ASTContext::GetBuiltinTypeError &Error,
4680                                  bool AllowTypeModifiers = true) {
4681  // Modifiers.
4682  int HowLong = 0;
4683  bool Signed = false, Unsigned = false;
4684
4685  // Read the modifiers first.
4686  bool Done = false;
4687  while (!Done) {
4688    switch (*Str++) {
4689    default: Done = true; --Str; break;
4690    case 'S':
4691      assert(!Unsigned && "Can't use both 'S' and 'U' modifiers!");
4692      assert(!Signed && "Can't use 'S' modifier multiple times!");
4693      Signed = true;
4694      break;
4695    case 'U':
4696      assert(!Signed && "Can't use both 'S' and 'U' modifiers!");
4697      assert(!Unsigned && "Can't use 'S' modifier multiple times!");
4698      Unsigned = true;
4699      break;
4700    case 'L':
4701      assert(HowLong <= 2 && "Can't have LLLL modifier");
4702      ++HowLong;
4703      break;
4704    }
4705  }
4706
4707  QualType Type;
4708
4709  // Read the base type.
4710  switch (*Str++) {
4711  default: assert(0 && "Unknown builtin type letter!");
4712  case 'v':
4713    assert(HowLong == 0 && !Signed && !Unsigned &&
4714           "Bad modifiers used with 'v'!");
4715    Type = Context.VoidTy;
4716    break;
4717  case 'f':
4718    assert(HowLong == 0 && !Signed && !Unsigned &&
4719           "Bad modifiers used with 'f'!");
4720    Type = Context.FloatTy;
4721    break;
4722  case 'd':
4723    assert(HowLong < 2 && !Signed && !Unsigned &&
4724           "Bad modifiers used with 'd'!");
4725    if (HowLong)
4726      Type = Context.LongDoubleTy;
4727    else
4728      Type = Context.DoubleTy;
4729    break;
4730  case 's':
4731    assert(HowLong == 0 && "Bad modifiers used with 's'!");
4732    if (Unsigned)
4733      Type = Context.UnsignedShortTy;
4734    else
4735      Type = Context.ShortTy;
4736    break;
4737  case 'i':
4738    if (HowLong == 3)
4739      Type = Unsigned ? Context.UnsignedInt128Ty : Context.Int128Ty;
4740    else if (HowLong == 2)
4741      Type = Unsigned ? Context.UnsignedLongLongTy : Context.LongLongTy;
4742    else if (HowLong == 1)
4743      Type = Unsigned ? Context.UnsignedLongTy : Context.LongTy;
4744    else
4745      Type = Unsigned ? Context.UnsignedIntTy : Context.IntTy;
4746    break;
4747  case 'c':
4748    assert(HowLong == 0 && "Bad modifiers used with 'c'!");
4749    if (Signed)
4750      Type = Context.SignedCharTy;
4751    else if (Unsigned)
4752      Type = Context.UnsignedCharTy;
4753    else
4754      Type = Context.CharTy;
4755    break;
4756  case 'b': // boolean
4757    assert(HowLong == 0 && !Signed && !Unsigned && "Bad modifiers for 'b'!");
4758    Type = Context.BoolTy;
4759    break;
4760  case 'z':  // size_t.
4761    assert(HowLong == 0 && !Signed && !Unsigned && "Bad modifiers for 'z'!");
4762    Type = Context.getSizeType();
4763    break;
4764  case 'F':
4765    Type = Context.getCFConstantStringType();
4766    break;
4767  case 'a':
4768    Type = Context.getBuiltinVaListType();
4769    assert(!Type.isNull() && "builtin va list type not initialized!");
4770    break;
4771  case 'A':
4772    // This is a "reference" to a va_list; however, what exactly
4773    // this means depends on how va_list is defined. There are two
4774    // different kinds of va_list: ones passed by value, and ones
4775    // passed by reference.  An example of a by-value va_list is
4776    // x86, where va_list is a char*. An example of by-ref va_list
4777    // is x86-64, where va_list is a __va_list_tag[1]. For x86,
4778    // we want this argument to be a char*&; for x86-64, we want
4779    // it to be a __va_list_tag*.
4780    Type = Context.getBuiltinVaListType();
4781    assert(!Type.isNull() && "builtin va list type not initialized!");
4782    if (Type->isArrayType()) {
4783      Type = Context.getArrayDecayedType(Type);
4784    } else {
4785      Type = Context.getLValueReferenceType(Type);
4786    }
4787    break;
4788  case 'V': {
4789    char *End;
4790    unsigned NumElements = strtoul(Str, &End, 10);
4791    assert(End != Str && "Missing vector size");
4792
4793    Str = End;
4794
4795    QualType ElementType = DecodeTypeFromStr(Str, Context, Error, false);
4796    // FIXME: Don't know what to do about AltiVec.
4797    Type = Context.getVectorType(ElementType, NumElements, false, false);
4798    break;
4799  }
4800  case 'X': {
4801    QualType ElementType = DecodeTypeFromStr(Str, Context, Error, false);
4802    Type = Context.getComplexType(ElementType);
4803    break;
4804  }
4805  case 'P':
4806    Type = Context.getFILEType();
4807    if (Type.isNull()) {
4808      Error = ASTContext::GE_Missing_stdio;
4809      return QualType();
4810    }
4811    break;
4812  case 'J':
4813    if (Signed)
4814      Type = Context.getsigjmp_bufType();
4815    else
4816      Type = Context.getjmp_bufType();
4817
4818    if (Type.isNull()) {
4819      Error = ASTContext::GE_Missing_setjmp;
4820      return QualType();
4821    }
4822    break;
4823  }
4824
4825  if (!AllowTypeModifiers)
4826    return Type;
4827
4828  Done = false;
4829  while (!Done) {
4830    switch (char c = *Str++) {
4831      default: Done = true; --Str; break;
4832      case '*':
4833      case '&':
4834        {
4835          // Both pointers and references can have their pointee types
4836          // qualified with an address space.
4837          char *End;
4838          unsigned AddrSpace = strtoul(Str, &End, 10);
4839          if (End != Str && AddrSpace != 0) {
4840            Type = Context.getAddrSpaceQualType(Type, AddrSpace);
4841            Str = End;
4842          }
4843        }
4844        if (c == '*')
4845          Type = Context.getPointerType(Type);
4846        else
4847          Type = Context.getLValueReferenceType(Type);
4848        break;
4849      // FIXME: There's no way to have a built-in with an rvalue ref arg.
4850      case 'C':
4851        Type = Type.withConst();
4852        break;
4853      case 'D':
4854        Type = Context.getVolatileType(Type);
4855        break;
4856    }
4857  }
4858
4859  return Type;
4860}
4861
4862/// GetBuiltinType - Return the type for the specified builtin.
4863QualType ASTContext::GetBuiltinType(unsigned id,
4864                                    GetBuiltinTypeError &Error) {
4865  const char *TypeStr = BuiltinInfo.GetTypeString(id);
4866
4867  llvm::SmallVector<QualType, 8> ArgTypes;
4868
4869  Error = GE_None;
4870  QualType ResType = DecodeTypeFromStr(TypeStr, *this, Error);
4871  if (Error != GE_None)
4872    return QualType();
4873  while (TypeStr[0] && TypeStr[0] != '.') {
4874    QualType Ty = DecodeTypeFromStr(TypeStr, *this, Error);
4875    if (Error != GE_None)
4876      return QualType();
4877
4878    // Do array -> pointer decay.  The builtin should use the decayed type.
4879    if (Ty->isArrayType())
4880      Ty = getArrayDecayedType(Ty);
4881
4882    ArgTypes.push_back(Ty);
4883  }
4884
4885  assert((TypeStr[0] != '.' || TypeStr[1] == 0) &&
4886         "'.' should only occur at end of builtin type list!");
4887
4888  // handle untyped/variadic arguments "T c99Style();" or "T cppStyle(...);".
4889  if (ArgTypes.size() == 0 && TypeStr[0] == '.')
4890    return getFunctionNoProtoType(ResType);
4891
4892  // FIXME: Should we create noreturn types?
4893  return getFunctionType(ResType, ArgTypes.data(), ArgTypes.size(),
4894                         TypeStr[0] == '.', 0, false, false, 0, 0,
4895                         false, CC_Default);
4896}
4897
4898QualType
4899ASTContext::UsualArithmeticConversionsType(QualType lhs, QualType rhs) {
4900  // Perform the usual unary conversions. We do this early so that
4901  // integral promotions to "int" can allow us to exit early, in the
4902  // lhs == rhs check. Also, for conversion purposes, we ignore any
4903  // qualifiers.  For example, "const float" and "float" are
4904  // equivalent.
4905  if (lhs->isPromotableIntegerType())
4906    lhs = getPromotedIntegerType(lhs);
4907  else
4908    lhs = lhs.getUnqualifiedType();
4909  if (rhs->isPromotableIntegerType())
4910    rhs = getPromotedIntegerType(rhs);
4911  else
4912    rhs = rhs.getUnqualifiedType();
4913
4914  // If both types are identical, no conversion is needed.
4915  if (lhs == rhs)
4916    return lhs;
4917
4918  // If either side is a non-arithmetic type (e.g. a pointer), we are done.
4919  // The caller can deal with this (e.g. pointer + int).
4920  if (!lhs->isArithmeticType() || !rhs->isArithmeticType())
4921    return lhs;
4922
4923  // At this point, we have two different arithmetic types.
4924
4925  // Handle complex types first (C99 6.3.1.8p1).
4926  if (lhs->isComplexType() || rhs->isComplexType()) {
4927    // if we have an integer operand, the result is the complex type.
4928    if (rhs->isIntegerType() || rhs->isComplexIntegerType()) {
4929      // convert the rhs to the lhs complex type.
4930      return lhs;
4931    }
4932    if (lhs->isIntegerType() || lhs->isComplexIntegerType()) {
4933      // convert the lhs to the rhs complex type.
4934      return rhs;
4935    }
4936    // This handles complex/complex, complex/float, or float/complex.
4937    // When both operands are complex, the shorter operand is converted to the
4938    // type of the longer, and that is the type of the result. This corresponds
4939    // to what is done when combining two real floating-point operands.
4940    // The fun begins when size promotion occur across type domains.
4941    // From H&S 6.3.4: When one operand is complex and the other is a real
4942    // floating-point type, the less precise type is converted, within it's
4943    // real or complex domain, to the precision of the other type. For example,
4944    // when combining a "long double" with a "double _Complex", the
4945    // "double _Complex" is promoted to "long double _Complex".
4946    int result = getFloatingTypeOrder(lhs, rhs);
4947
4948    if (result > 0) { // The left side is bigger, convert rhs.
4949      rhs = getFloatingTypeOfSizeWithinDomain(lhs, rhs);
4950    } else if (result < 0) { // The right side is bigger, convert lhs.
4951      lhs = getFloatingTypeOfSizeWithinDomain(rhs, lhs);
4952    }
4953    // At this point, lhs and rhs have the same rank/size. Now, make sure the
4954    // domains match. This is a requirement for our implementation, C99
4955    // does not require this promotion.
4956    if (lhs != rhs) { // Domains don't match, we have complex/float mix.
4957      if (lhs->isRealFloatingType()) { // handle "double, _Complex double".
4958        return rhs;
4959      } else { // handle "_Complex double, double".
4960        return lhs;
4961      }
4962    }
4963    return lhs; // The domain/size match exactly.
4964  }
4965  // Now handle "real" floating types (i.e. float, double, long double).
4966  if (lhs->isRealFloatingType() || rhs->isRealFloatingType()) {
4967    // if we have an integer operand, the result is the real floating type.
4968    if (rhs->isIntegerType()) {
4969      // convert rhs to the lhs floating point type.
4970      return lhs;
4971    }
4972    if (rhs->isComplexIntegerType()) {
4973      // convert rhs to the complex floating point type.
4974      return getComplexType(lhs);
4975    }
4976    if (lhs->isIntegerType()) {
4977      // convert lhs to the rhs floating point type.
4978      return rhs;
4979    }
4980    if (lhs->isComplexIntegerType()) {
4981      // convert lhs to the complex floating point type.
4982      return getComplexType(rhs);
4983    }
4984    // We have two real floating types, float/complex combos were handled above.
4985    // Convert the smaller operand to the bigger result.
4986    int result = getFloatingTypeOrder(lhs, rhs);
4987    if (result > 0) // convert the rhs
4988      return lhs;
4989    assert(result < 0 && "illegal float comparison");
4990    return rhs;   // convert the lhs
4991  }
4992  if (lhs->isComplexIntegerType() || rhs->isComplexIntegerType()) {
4993    // Handle GCC complex int extension.
4994    const ComplexType *lhsComplexInt = lhs->getAsComplexIntegerType();
4995    const ComplexType *rhsComplexInt = rhs->getAsComplexIntegerType();
4996
4997    if (lhsComplexInt && rhsComplexInt) {
4998      if (getIntegerTypeOrder(lhsComplexInt->getElementType(),
4999                              rhsComplexInt->getElementType()) >= 0)
5000        return lhs; // convert the rhs
5001      return rhs;
5002    } else if (lhsComplexInt && rhs->isIntegerType()) {
5003      // convert the rhs to the lhs complex type.
5004      return lhs;
5005    } else if (rhsComplexInt && lhs->isIntegerType()) {
5006      // convert the lhs to the rhs complex type.
5007      return rhs;
5008    }
5009  }
5010  // Finally, we have two differing integer types.
5011  // The rules for this case are in C99 6.3.1.8
5012  int compare = getIntegerTypeOrder(lhs, rhs);
5013  bool lhsSigned = lhs->isSignedIntegerType(),
5014       rhsSigned = rhs->isSignedIntegerType();
5015  QualType destType;
5016  if (lhsSigned == rhsSigned) {
5017    // Same signedness; use the higher-ranked type
5018    destType = compare >= 0 ? lhs : rhs;
5019  } else if (compare != (lhsSigned ? 1 : -1)) {
5020    // The unsigned type has greater than or equal rank to the
5021    // signed type, so use the unsigned type
5022    destType = lhsSigned ? rhs : lhs;
5023  } else if (getIntWidth(lhs) != getIntWidth(rhs)) {
5024    // The two types are different widths; if we are here, that
5025    // means the signed type is larger than the unsigned type, so
5026    // use the signed type.
5027    destType = lhsSigned ? lhs : rhs;
5028  } else {
5029    // The signed type is higher-ranked than the unsigned type,
5030    // but isn't actually any bigger (like unsigned int and long
5031    // on most 32-bit systems).  Use the unsigned type corresponding
5032    // to the signed type.
5033    destType = getCorrespondingUnsignedType(lhsSigned ? lhs : rhs);
5034  }
5035  return destType;
5036}
5037