ASTContext.h revision 153bfe5795e2c1a5a738e73d3784964e082237fc 
1//===--- ASTContext.h - Context to hold long-lived AST nodes ----*- C++ -*-===//
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 defines the ASTContext interface.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_ASTCONTEXT_H
15#define LLVM_CLANG_AST_ASTCONTEXT_H
16
17#include "clang/Basic/IdentifierTable.h"
18#include "clang/Basic/LangOptions.h"
19#include "clang/AST/Builtins.h"
20#include "clang/AST/Decl.h"
21#include "clang/AST/NestedNameSpecifier.h"
22#include "clang/AST/TemplateName.h"
23#include "clang/AST/Type.h"
24#include "clang/Basic/SourceLocation.h"
25#include "llvm/ADT/DenseMap.h"
26#include "llvm/ADT/FoldingSet.h"
27#include "llvm/ADT/OwningPtr.h"
28#include "llvm/Bitcode/SerializationFwd.h"
29#include "llvm/Support/Allocator.h"
30#include <vector>
31
32namespace llvm {
33  struct fltSemantics;
34}
35
36namespace clang {
37  class FileManager;
38  class ASTRecordLayout;
39  class Expr;
40  class ExternalASTSource;
41  class IdentifierTable;
42  class SelectorTable;
43  class SourceManager;
44  class TargetInfo;
45  // Decls
46  class Decl;
47  class ObjCPropertyDecl;
48  class RecordDecl;
49  class TagDecl;
50  class TranslationUnitDecl;
51  class TypeDecl;
52  class TypedefDecl;
53  class TemplateTypeParmDecl;
54  class FieldDecl;
55  class ObjCIvarRefExpr;
56  class ObjCIvarDecl;
57
58/// ASTContext - This class holds long-lived AST nodes (such as types and
59/// decls) that can be referred to throughout the semantic analysis of a file.
60class ASTContext {
61  std::vector<Type*> Types;
62  llvm::FoldingSet<ExtQualType> ExtQualTypes;
63  llvm::FoldingSet<ComplexType> ComplexTypes;
64  llvm::FoldingSet<PointerType> PointerTypes;
65  llvm::FoldingSet<BlockPointerType> BlockPointerTypes;
66  llvm::FoldingSet<LValueReferenceType> LValueReferenceTypes;
67  llvm::FoldingSet<RValueReferenceType> RValueReferenceTypes;
68  llvm::FoldingSet<MemberPointerType> MemberPointerTypes;
69  llvm::FoldingSet<ConstantArrayType> ConstantArrayTypes;
70  llvm::FoldingSet<IncompleteArrayType> IncompleteArrayTypes;
71  std::vector<VariableArrayType*> VariableArrayTypes;
72  std::vector<DependentSizedArrayType*> DependentSizedArrayTypes;
73  llvm::FoldingSet<VectorType> VectorTypes;
74  llvm::FoldingSet<FunctionNoProtoType> FunctionNoProtoTypes;
75  llvm::FoldingSet<FunctionProtoType> FunctionProtoTypes;
76  llvm::FoldingSet<TemplateTypeParmType> TemplateTypeParmTypes;
77  llvm::FoldingSet<TemplateSpecializationType> TemplateSpecializationTypes;
78  llvm::FoldingSet<QualifiedNameType> QualifiedNameTypes;
79  llvm::FoldingSet<TypenameType> TypenameTypes;
80  llvm::FoldingSet<ObjCQualifiedInterfaceType> ObjCQualifiedInterfaceTypes;
81  llvm::FoldingSet<ObjCQualifiedIdType> ObjCQualifiedIdTypes;
82
83  llvm::FoldingSet<QualifiedTemplateName> QualifiedTemplateNames;
84  llvm::FoldingSet<DependentTemplateName> DependentTemplateNames;
85
86  /// \brief The set of nested name specifiers.
87  ///
88  /// This set is managed by the NestedNameSpecifier class.
89  llvm::FoldingSet<NestedNameSpecifier> NestedNameSpecifiers;
90  NestedNameSpecifier *GlobalNestedNameSpecifier;
91  friend class NestedNameSpecifier;
92
93  /// ASTRecordLayouts - A cache mapping from RecordDecls to ASTRecordLayouts.
94  ///  This is lazily created.  This is intentionally not serialized.
95  llvm::DenseMap<const RecordDecl*, const ASTRecordLayout*> ASTRecordLayouts;
96  llvm::DenseMap<const ObjCInterfaceDecl*,
97                 const ASTRecordLayout*> ASTObjCInterfaces;
98
99  llvm::DenseMap<unsigned, FixedWidthIntType*> SignedFixedWidthIntTypes;
100  llvm::DenseMap<unsigned, FixedWidthIntType*> UnsignedFixedWidthIntTypes;
101
102  // FIXME: ASTRecordForInterface/ASTFieldForIvarRef and addRecordToClass and
103  // getFieldDecl be part of the backend (i.e. CodeGenTypes)?
104  llvm::DenseMap<const ObjCInterfaceDecl*, RecordDecl*> ASTRecordForInterface;
105  llvm::DenseMap<const ObjCIvarRefExpr*, const FieldDecl*> ASTFieldForIvarRef;
106
107  /// BuiltinVaListType - built-in va list type.
108  /// This is initially null and set by Sema::LazilyCreateBuiltin when
109  /// a builtin that takes a valist is encountered.
110  QualType BuiltinVaListType;
111
112  /// ObjCIdType - a pseudo built-in typedef type (set by Sema).
113  QualType ObjCIdType;
114  const RecordType *IdStructType;
115
116  /// ObjCSelType - another pseudo built-in typedef type (set by Sema).
117  QualType ObjCSelType;
118  const RecordType *SelStructType;
119
120  /// ObjCProtoType - another pseudo built-in typedef type (set by Sema).
121  QualType ObjCProtoType;
122  const RecordType *ProtoStructType;
123
124  /// ObjCClassType - another pseudo built-in typedef type (set by Sema).
125  QualType ObjCClassType;
126  const RecordType *ClassStructType;
127
128  QualType ObjCConstantStringType;
129  RecordDecl *CFConstantStringTypeDecl;
130
131  RecordDecl *ObjCFastEnumerationStateTypeDecl;
132
133  TranslationUnitDecl *TUDecl;
134
135  /// SourceMgr - The associated SourceManager object.
136  SourceManager &SourceMgr;
137
138  /// LangOpts - The language options used to create the AST associated with
139  ///  this ASTContext object.
140  LangOptions LangOpts;
141
142  /// MallocAlloc/BumpAlloc - The allocator objects used to create AST objects.
143  bool FreeMemory;
144  llvm::MallocAllocator MallocAlloc;
145  llvm::BumpPtrAllocator BumpAlloc;
146public:
147  TargetInfo &Target;
148  IdentifierTable &Idents;
149  SelectorTable &Selectors;
150  DeclarationNameTable DeclarationNames;
151  llvm::OwningPtr<ExternalASTSource> ExternalSource;
152
153  SourceManager& getSourceManager() { return SourceMgr; }
154  const SourceManager& getSourceManager() const { return SourceMgr; }
155  void *Allocate(unsigned Size, unsigned Align = 8) {
156    return FreeMemory ? MallocAlloc.Allocate(Size, Align) :
157                        BumpAlloc.Allocate(Size, Align);
158  }
159  void Deallocate(void *Ptr) {
160    if (FreeMemory)
161      MallocAlloc.Deallocate(Ptr);
162  }
163  const LangOptions& getLangOptions() const { return LangOpts; }
164
165  FullSourceLoc getFullLoc(SourceLocation Loc) const {
166    return FullSourceLoc(Loc,SourceMgr);
167  }
168
169  TranslationUnitDecl *getTranslationUnitDecl() const { return TUDecl; }
170
171  /// This is intentionally not serialized.  It is populated by the
172  /// ASTContext ctor, and there are no external pointers/references to
173  /// internal variables of BuiltinInfo.
174  Builtin::Context BuiltinInfo;
175
176  // Builtin Types.
177  QualType VoidTy;
178  QualType BoolTy;
179  QualType CharTy;
180  QualType WCharTy; // [C++ 3.9.1p5], integer type in C99.
181  QualType SignedCharTy, ShortTy, IntTy, LongTy, LongLongTy;
182  QualType UnsignedCharTy, UnsignedShortTy, UnsignedIntTy, UnsignedLongTy;
183  QualType UnsignedLongLongTy;
184  QualType FloatTy, DoubleTy, LongDoubleTy;
185  QualType FloatComplexTy, DoubleComplexTy, LongDoubleComplexTy;
186  QualType VoidPtrTy;
187  QualType OverloadTy;
188  QualType DependentTy;
189
190  ASTContext(const LangOptions& LOpts, SourceManager &SM, TargetInfo &t,
191             IdentifierTable &idents, SelectorTable &sels,
192             bool FreeMemory = true, unsigned size_reserve=0);
193
194  ~ASTContext();
195
196  /// \brief Attach an external AST source to the AST context.
197  ///
198  /// The external AST source provides the ability to load parts of
199  /// the abstract syntax tree as needed from some external storage,
200  /// e.g., a precompiled header.
201  void setExternalSource(llvm::OwningPtr<ExternalASTSource> &Source);
202
203  /// \brief Retrieve a pointer to the external AST source associated
204  /// with this AST context, if any.
205  ExternalASTSource *getExternalSource() const { return ExternalSource.get(); }
206
207  void PrintStats() const;
208  const std::vector<Type*>& getTypes() const { return Types; }
209
210  //===--------------------------------------------------------------------===//
211  //                           Type Constructors
212  //===--------------------------------------------------------------------===//
213
214  /// getAddSpaceQualType - Return the uniqued reference to the type for an
215  /// address space qualified type with the specified type and address space.
216  /// The resulting type has a union of the qualifiers from T and the address
217  /// space. If T already has an address space specifier, it is silently
218  /// replaced.
219  QualType getAddrSpaceQualType(QualType T, unsigned AddressSpace);
220
221  /// getObjCGCQualType - Returns the uniqued reference to the type for an
222  /// objc gc qualified type. The retulting type has a union of the qualifiers
223  /// from T and the gc attribute.
224  QualType getObjCGCQualType(QualType T, QualType::GCAttrTypes gcAttr);
225
226  /// getComplexType - Return the uniqued reference to the type for a complex
227  /// number with the specified element type.
228  QualType getComplexType(QualType T);
229
230  /// getPointerType - Return the uniqued reference to the type for a pointer to
231  /// the specified type.
232  QualType getPointerType(QualType T);
233
234  /// getBlockPointerType - Return the uniqued reference to the type for a block
235  /// of the specified type.
236  QualType getBlockPointerType(QualType T);
237
238  /// getLValueReferenceType - Return the uniqued reference to the type for an
239  /// lvalue reference to the specified type.
240  QualType getLValueReferenceType(QualType T);
241
242  /// getRValueReferenceType - Return the uniqued reference to the type for an
243  /// rvalue reference to the specified type.
244  QualType getRValueReferenceType(QualType T);
245
246  /// getMemberPointerType - Return the uniqued reference to the type for a
247  /// member pointer to the specified type in the specified class. The class
248  /// is a Type because it could be a dependent name.
249  QualType getMemberPointerType(QualType T, const Type *Cls);
250
251  /// getVariableArrayType - Returns a non-unique reference to the type for a
252  /// variable array of the specified element type.
253  QualType getVariableArrayType(QualType EltTy, Expr *NumElts,
254                                ArrayType::ArraySizeModifier ASM,
255                                unsigned EltTypeQuals);
256
257  /// getDependentSizedArrayType - Returns a non-unique reference to
258  /// the type for a dependently-sized array of the specified element
259  /// type. FIXME: We will need these to be uniqued, or at least
260  /// comparable, at some point.
261  QualType getDependentSizedArrayType(QualType EltTy, Expr *NumElts,
262                                      ArrayType::ArraySizeModifier ASM,
263                                      unsigned EltTypeQuals);
264
265  /// getIncompleteArrayType - Returns a unique reference to the type for a
266  /// incomplete array of the specified element type.
267  QualType getIncompleteArrayType(QualType EltTy,
268                                  ArrayType::ArraySizeModifier ASM,
269                                  unsigned EltTypeQuals);
270
271  /// getConstantArrayType - Return the unique reference to the type for a
272  /// constant array of the specified element type.
273  QualType getConstantArrayType(QualType EltTy, const llvm::APInt &ArySize,
274                                ArrayType::ArraySizeModifier ASM,
275                                unsigned EltTypeQuals);
276
277  /// getVectorType - Return the unique reference to a vector type of
278  /// the specified element type and size. VectorType must be a built-in type.
279  QualType getVectorType(QualType VectorType, unsigned NumElts);
280
281  /// getExtVectorType - Return the unique reference to an extended vector type
282  /// of the specified element type and size.  VectorType must be a built-in
283  /// type.
284  QualType getExtVectorType(QualType VectorType, unsigned NumElts);
285
286  /// getFunctionNoProtoType - Return a K&R style C function type like 'int()'.
287  ///
288  QualType getFunctionNoProtoType(QualType ResultTy);
289
290  /// getFunctionType - Return a normal function type with a typed argument
291  /// list.  isVariadic indicates whether the argument list includes '...'.
292  QualType getFunctionType(QualType ResultTy, const QualType *ArgArray,
293                           unsigned NumArgs, bool isVariadic,
294                           unsigned TypeQuals);
295
296  /// getTypeDeclType - Return the unique reference to the type for
297  /// the specified type declaration.
298  QualType getTypeDeclType(TypeDecl *Decl, TypeDecl* PrevDecl=0);
299
300  /// getTypedefType - Return the unique reference to the type for the
301  /// specified typename decl.
302  QualType getTypedefType(TypedefDecl *Decl);
303  QualType getObjCInterfaceType(ObjCInterfaceDecl *Decl);
304
305  QualType getTemplateTypeParmType(unsigned Depth, unsigned Index,
306                                   IdentifierInfo *Name = 0);
307
308  QualType getTemplateSpecializationType(TemplateName T,
309                                         const TemplateArgument *Args,
310                                         unsigned NumArgs,
311                                         QualType Canon = QualType());
312
313  QualType getQualifiedNameType(NestedNameSpecifier *NNS,
314                                QualType NamedType);
315  QualType getTypenameType(NestedNameSpecifier *NNS,
316                           const IdentifierInfo *Name,
317                           QualType Canon = QualType());
318  QualType getTypenameType(NestedNameSpecifier *NNS,
319                           const TemplateSpecializationType *TemplateId,
320                           QualType Canon = QualType());
321
322  /// getObjCQualifiedInterfaceType - Return a
323  /// ObjCQualifiedInterfaceType type for the given interface decl and
324  /// the conforming protocol list.
325  QualType getObjCQualifiedInterfaceType(ObjCInterfaceDecl *Decl,
326                                         ObjCProtocolDecl **ProtocolList,
327                                         unsigned NumProtocols);
328
329  /// getObjCQualifiedIdType - Return an ObjCQualifiedIdType for a
330  /// given 'id' and conforming protocol list.
331  QualType getObjCQualifiedIdType(ObjCProtocolDecl **ProtocolList,
332                                  unsigned NumProtocols);
333
334
335  /// getTypeOfType - GCC extension.
336  QualType getTypeOfExprType(Expr *e);
337  QualType getTypeOfType(QualType t);
338
339  /// getTagDeclType - Return the unique reference to the type for the
340  /// specified TagDecl (struct/union/class/enum) decl.
341  QualType getTagDeclType(TagDecl *Decl);
342
343  /// getSizeType - Return the unique type for "size_t" (C99 7.17), defined
344  /// in <stddef.h>. The sizeof operator requires this (C99 6.5.3.4p4).
345  QualType getSizeType() const;
346
347  /// getWCharType - In C++, this returns the unique wchar_t type.  In C99, this
348  /// returns a type compatible with the type defined in <stddef.h> as defined
349  /// by the target.
350  QualType getWCharType() const { return WCharTy; }
351
352  /// getSignedWCharType - Return the type of "signed wchar_t".
353  /// Used when in C++, as a GCC extension.
354  QualType getSignedWCharType() const;
355
356  /// getUnsignedWCharType - Return the type of "unsigned wchar_t".
357  /// Used when in C++, as a GCC extension.
358  QualType getUnsignedWCharType() const;
359
360  /// getPointerDiffType - Return the unique type for "ptrdiff_t" (ref?)
361  /// defined in <stddef.h>. Pointer - pointer requires this (C99 6.5.6p9).
362  QualType getPointerDiffType() const;
363
364  // getCFConstantStringType - Return the C structure type used to represent
365  // constant CFStrings.
366  QualType getCFConstantStringType();
367
368  // This setter/getter represents the ObjC type for an NSConstantString.
369  void setObjCConstantStringInterface(ObjCInterfaceDecl *Decl);
370  QualType getObjCConstantStringInterface() const {
371    return ObjCConstantStringType;
372  }
373
374  //// This gets the struct used to keep track of fast enumerations.
375  QualType getObjCFastEnumerationStateType();
376
377  /// getObjCEncodingForType - Emit the ObjC type encoding for the
378  /// given type into \arg S. If \arg NameFields is specified then
379  /// record field names are also encoded.
380  void getObjCEncodingForType(QualType t, std::string &S,
381                              const FieldDecl *Field=0);
382
383  void getLegacyIntegralTypeEncoding(QualType &t) const;
384
385  // Put the string version of type qualifiers into S.
386  void getObjCEncodingForTypeQualifier(Decl::ObjCDeclQualifier QT,
387                                       std::string &S) const;
388
389  /// getObjCEncodingForMethodDecl - Return the encoded type for this method
390  /// declaration.
391  void getObjCEncodingForMethodDecl(const ObjCMethodDecl *Decl, std::string &S);
392
393  /// getObjCEncodingForPropertyDecl - Return the encoded type for
394  /// this method declaration. If non-NULL, Container must be either
395  /// an ObjCCategoryImplDecl or ObjCImplementationDecl; it should
396  /// only be NULL when getting encodings for protocol properties.
397  void getObjCEncodingForPropertyDecl(const ObjCPropertyDecl *PD,
398                                      const Decl *Container,
399                                      std::string &S);
400
401  /// getObjCEncodingTypeSize returns size of type for objective-c encoding
402  /// purpose.
403  int getObjCEncodingTypeSize(QualType t);
404
405  /// This setter/getter represents the ObjC 'id' type. It is setup lazily, by
406  /// Sema.  id is always a (typedef for a) pointer type, a pointer to a struct.
407  QualType getObjCIdType() const { return ObjCIdType; }
408  void setObjCIdType(TypedefDecl *Decl);
409
410  void setObjCSelType(TypedefDecl *Decl);
411  QualType getObjCSelType() const { return ObjCSelType; }
412
413  void setObjCProtoType(QualType QT);
414  QualType getObjCProtoType() const { return ObjCProtoType; }
415
416  /// This setter/getter repreents the ObjC 'Class' type. It is setup lazily, by
417  /// Sema.  'Class' is always a (typedef for a) pointer type, a pointer to a
418  /// struct.
419  QualType getObjCClassType() const { return ObjCClassType; }
420  void setObjCClassType(TypedefDecl *Decl);
421
422  void setBuiltinVaListType(QualType T);
423  QualType getBuiltinVaListType() const { return BuiltinVaListType; }
424
425  QualType getFixedWidthIntType(unsigned Width, bool Signed);
426
427  TemplateName getQualifiedTemplateName(NestedNameSpecifier *NNS,
428                                        bool TemplateKeyword,
429                                        TemplateDecl *Template);
430
431  TemplateName getDependentTemplateName(NestedNameSpecifier *NNS,
432                                        const IdentifierInfo *Name);
433
434private:
435  QualType getFromTargetType(unsigned Type) const;
436
437  //===--------------------------------------------------------------------===//
438  //                         Type Predicates.
439  //===--------------------------------------------------------------------===//
440
441public:
442  /// isObjCObjectPointerType - Returns true if type is an Objective-C pointer
443  /// to an object type.  This includes "id" and "Class" (two 'special' pointers
444  /// to struct), Interface* (pointer to ObjCInterfaceType) and id<P> (qualified
445  /// ID type).
446  bool isObjCObjectPointerType(QualType Ty) const;
447
448  /// getObjCGCAttr - Returns one of GCNone, Weak or Strong objc's
449  /// garbage collection attribute.
450  ///
451  QualType::GCAttrTypes getObjCGCAttrKind(const QualType &Ty) const;
452
453  /// isObjCNSObjectType - Return true if this is an NSObject object with
454  /// its NSObject attribute set.
455  bool isObjCNSObjectType(QualType Ty) const;
456
457  //===--------------------------------------------------------------------===//
458  //                         Type Sizing and Analysis
459  //===--------------------------------------------------------------------===//
460
461  /// getFloatTypeSemantics - Return the APFloat 'semantics' for the specified
462  /// scalar floating point type.
463  const llvm::fltSemantics &getFloatTypeSemantics(QualType T) const;
464
465  /// getTypeInfo - Get the size and alignment of the specified complete type in
466  /// bits.
467  std::pair<uint64_t, unsigned> getTypeInfo(const Type *T);
468  std::pair<uint64_t, unsigned> getTypeInfo(QualType T) {
469    return getTypeInfo(T.getTypePtr());
470  }
471
472  /// getTypeSize - Return the size of the specified type, in bits.  This method
473  /// does not work on incomplete types.
474  uint64_t getTypeSize(QualType T) {
475    return getTypeInfo(T).first;
476  }
477  uint64_t getTypeSize(const Type *T) {
478    return getTypeInfo(T).first;
479  }
480
481  /// getTypeAlign - Return the ABI-specified alignment of a type, in bits.
482  /// This method does not work on incomplete types.
483  unsigned getTypeAlign(QualType T) {
484    return getTypeInfo(T).second;
485  }
486  unsigned getTypeAlign(const Type *T) {
487    return getTypeInfo(T).second;
488  }
489
490  /// getPreferredTypeAlign - Return the "preferred" alignment of the specified
491  /// type for the current target in bits.  This can be different than the ABI
492  /// alignment in cases where it is beneficial for performance to overalign
493  /// a data type.
494  unsigned getPreferredTypeAlign(const Type *T);
495
496  /// getDeclAlignInBytes - Return the alignment of the specified decl
497  /// that should be returned by __alignof().  Note that bitfields do
498  /// not have a valid alignment, so this method will assert on them.
499  unsigned getDeclAlignInBytes(const Decl *D);
500
501  /// getASTRecordLayout - Get or compute information about the layout of the
502  /// specified record (struct/union/class), which indicates its size and field
503  /// position information.
504  const ASTRecordLayout &getASTRecordLayout(const RecordDecl *D);
505
506  const ASTRecordLayout &getASTObjCInterfaceLayout(const ObjCInterfaceDecl *D);
507  const RecordDecl *addRecordToClass(const ObjCInterfaceDecl *D);
508  void CollectObjCIvars(const ObjCInterfaceDecl *OI,
509                        llvm::SmallVectorImpl<FieldDecl*> &Fields);
510  const FieldDecl *getFieldDecl(const ObjCIvarRefExpr *MRef) {
511    llvm::DenseMap<const ObjCIvarRefExpr *, const FieldDecl*>::iterator I
512      = ASTFieldForIvarRef.find(MRef);
513    assert (I != ASTFieldForIvarRef.end()  && "Unable to find field_decl");
514    return I->second;
515  }
516  void setFieldDecl(const ObjCInterfaceDecl *OI,
517                    const ObjCIvarDecl *Ivar,
518                    const ObjCIvarRefExpr *MRef);
519  //===--------------------------------------------------------------------===//
520  //                            Type Operators
521  //===--------------------------------------------------------------------===//
522
523  /// getCanonicalType - Return the canonical (structural) type corresponding to
524  /// the specified potentially non-canonical type.  The non-canonical version
525  /// of a type may have many "decorated" versions of types.  Decorators can
526  /// include typedefs, 'typeof' operators, etc. The returned type is guaranteed
527  /// to be free of any of these, allowing two canonical types to be compared
528  /// for exact equality with a simple pointer comparison.
529  QualType getCanonicalType(QualType T);
530  const Type *getCanonicalType(const Type *T) {
531    return T->getCanonicalTypeInternal().getTypePtr();
532  }
533
534  /// \brief Determine whether the given types are equivalent.
535  bool hasSameType(QualType T1, QualType T2) {
536    return getCanonicalType(T1) == getCanonicalType(T2);
537  }
538
539  /// \brief Determine whether the given types are equivalent after
540  /// cvr-qualifiers have been removed.
541  bool hasSameUnqualifiedType(QualType T1, QualType T2) {
542    T1 = getCanonicalType(T1);
543    T2 = getCanonicalType(T2);
544    return T1.getUnqualifiedType() == T2.getUnqualifiedType();
545  }
546
547  /// \brief Retrieves the "canonical" declaration of the given tag
548  /// declaration.
549  ///
550  /// The canonical declaration for the given tag declaration is
551  /// either the definition of the tag (if it is a complete type) or
552  /// the first declaration of that tag.
553  TagDecl *getCanonicalDecl(TagDecl *Tag) {
554    QualType T = getTagDeclType(Tag);
555    return cast<TagDecl>(cast<TagType>(T.getTypePtr()->CanonicalType)
556                           ->getDecl());
557  }
558
559  /// \brief Retrieves the "canonical" nested name specifier for a
560  /// given nested name specifier.
561  ///
562  /// The canonical nested name specifier is a nested name specifier
563  /// that uniquely identifies a type or namespace within the type
564  /// system. For example, given:
565  ///
566  /// \code
567  /// namespace N {
568  ///   struct S {
569  ///     template<typename T> struct X { typename T* type; };
570  ///   };
571  /// }
572  ///
573  /// template<typename T> struct Y {
574  ///   typename N::S::X<T>::type member;
575  /// };
576  /// \endcode
577  ///
578  /// Here, the nested-name-specifier for N::S::X<T>:: will be
579  /// S::X<template-param-0-0>, since 'S' and 'X' are uniquely defined
580  /// by declarations in the type system and the canonical type for
581  /// the template type parameter 'T' is template-param-0-0.
582  NestedNameSpecifier *
583  getCanonicalNestedNameSpecifier(NestedNameSpecifier *NNS);
584
585  /// Type Query functions.  If the type is an instance of the specified class,
586  /// return the Type pointer for the underlying maximally pretty type.  This
587  /// is a member of ASTContext because this may need to do some amount of
588  /// canonicalization, e.g. to move type qualifiers into the element type.
589  const ArrayType *getAsArrayType(QualType T);
590  const ConstantArrayType *getAsConstantArrayType(QualType T) {
591    return dyn_cast_or_null<ConstantArrayType>(getAsArrayType(T));
592  }
593  const VariableArrayType *getAsVariableArrayType(QualType T) {
594    return dyn_cast_or_null<VariableArrayType>(getAsArrayType(T));
595  }
596  const IncompleteArrayType *getAsIncompleteArrayType(QualType T) {
597    return dyn_cast_or_null<IncompleteArrayType>(getAsArrayType(T));
598  }
599
600  /// getBaseElementType - Returns the innermost element type of a variable
601  /// length array type. For example, will return "int" for int[m][n]
602  QualType getBaseElementType(const VariableArrayType *VAT);
603
604  /// getArrayDecayedType - Return the properly qualified result of decaying the
605  /// specified array type to a pointer.  This operation is non-trivial when
606  /// handling typedefs etc.  The canonical type of "T" must be an array type,
607  /// this returns a pointer to a properly qualified element of the array.
608  ///
609  /// See C99 6.7.5.3p7 and C99 6.3.2.1p3.
610  QualType getArrayDecayedType(QualType T);
611
612  /// getIntegerTypeOrder - Returns the highest ranked integer type:
613  /// C99 6.3.1.8p1.  If LHS > RHS, return 1.  If LHS == RHS, return 0. If
614  /// LHS < RHS, return -1.
615  int getIntegerTypeOrder(QualType LHS, QualType RHS);
616
617  /// getFloatingTypeOrder - Compare the rank of the two specified floating
618  /// point types, ignoring the domain of the type (i.e. 'double' ==
619  /// '_Complex double').  If LHS > RHS, return 1.  If LHS == RHS, return 0. If
620  /// LHS < RHS, return -1.
621  int getFloatingTypeOrder(QualType LHS, QualType RHS);
622
623  /// getFloatingTypeOfSizeWithinDomain - Returns a real floating
624  /// point or a complex type (based on typeDomain/typeSize).
625  /// 'typeDomain' is a real floating point or complex type.
626  /// 'typeSize' is a real floating point or complex type.
627  QualType getFloatingTypeOfSizeWithinDomain(QualType typeSize,
628                                             QualType typeDomain) const;
629
630private:
631  // Helper for integer ordering
632  unsigned getIntegerRank(Type* T);
633
634public:
635
636  //===--------------------------------------------------------------------===//
637  //                    Type Compatibility Predicates
638  //===--------------------------------------------------------------------===//
639
640  /// Compatibility predicates used to check assignment expressions.
641  bool typesAreCompatible(QualType, QualType); // C99 6.2.7p1
642  bool typesAreBlockCompatible(QualType lhs, QualType rhs);
643
644  bool isObjCIdType(QualType T) const {
645    return T == ObjCIdType;
646  }
647  bool isObjCIdStructType(QualType T) const {
648    if (!IdStructType) // ObjC isn't enabled
649      return false;
650    return T->getAsStructureType() == IdStructType;
651  }
652  bool isObjCClassType(QualType T) const {
653    return T == ObjCClassType;
654  }
655  bool isObjCClassStructType(QualType T) const {
656    if (!ClassStructType) // ObjC isn't enabled
657      return false;
658    return T->getAsStructureType() == ClassStructType;
659  }
660  bool isObjCSelType(QualType T) const {
661    assert(SelStructType && "isObjCSelType used before 'SEL' type is built");
662    return T->getAsStructureType() == SelStructType;
663  }
664
665  // Check the safety of assignment from LHS to RHS
666  bool canAssignObjCInterfaces(const ObjCInterfaceType *LHS,
667                               const ObjCInterfaceType *RHS);
668  bool areComparableObjCPointerTypes(QualType LHS, QualType RHS);
669
670  // Functions for calculating composite types
671  QualType mergeTypes(QualType, QualType);
672  QualType mergeFunctionTypes(QualType, QualType);
673
674  //===--------------------------------------------------------------------===//
675  //                    Integer Predicates
676  //===--------------------------------------------------------------------===//
677
678  // The width of an integer, as defined in C99 6.2.6.2. This is the number
679  // of bits in an integer type excluding any padding bits.
680  unsigned getIntWidth(QualType T);
681
682  // Per C99 6.2.5p6, for every signed integer type, there is a corresponding
683  // unsigned integer type.  This method takes a signed type, and returns the
684  // corresponding unsigned integer type.
685  QualType getCorrespondingUnsignedType(QualType T);
686
687  //===--------------------------------------------------------------------===//
688  //                    Type Iterators.
689  //===--------------------------------------------------------------------===//
690
691  typedef std::vector<Type*>::iterator       type_iterator;
692  typedef std::vector<Type*>::const_iterator const_type_iterator;
693
694  type_iterator types_begin() { return Types.begin(); }
695  type_iterator types_end() { return Types.end(); }
696  const_type_iterator types_begin() const { return Types.begin(); }
697  const_type_iterator types_end() const { return Types.end(); }
698
699  //===--------------------------------------------------------------------===//
700  //                    Serialization
701  //===--------------------------------------------------------------------===//
702
703  void EmitASTBitcodeBuffer(std::vector<unsigned char> &Buffer) const;
704  static ASTContext *ReadASTBitcodeBuffer(llvm::MemoryBuffer &MBuffer,
705                                          FileManager &FMgr);
706
707  void Emit(llvm::Serializer& S) const;
708  static ASTContext *Create(llvm::Deserializer& D);
709
710  //===--------------------------------------------------------------------===//
711  //                    Integer Values
712  //===--------------------------------------------------------------------===//
713
714  /// MakeIntValue - Make an APSInt of the appropriate width and
715  /// signedness for the given \arg Value and integer \arg Type.
716  llvm::APSInt MakeIntValue(uint64_t Value, QualType Type) {
717    llvm::APSInt Res(getIntWidth(Type), !Type->isSignedIntegerType());
718    Res = Value;
719    return Res;
720  }
721
722private:
723  ASTContext(const ASTContext&); // DO NOT IMPLEMENT
724  void operator=(const ASTContext&); // DO NOT IMPLEMENT
725
726  void InitBuiltinTypes();
727  void InitBuiltinType(QualType &R, BuiltinType::Kind K);
728
729  // Return the ObjC type encoding for a given type.
730  void getObjCEncodingForTypeImpl(QualType t, std::string &S,
731                                  bool ExpandPointedToStructures,
732                                  bool ExpandStructures,
733                                  const FieldDecl *Field,
734                                  bool OutermostType = false,
735                                  bool EncodingProperty = false);
736
737};
738
739}  // end namespace clang
740
741// operator new and delete aren't allowed inside namespaces.
742// The throw specifications are mandated by the standard.
743/// @brief Placement new for using the ASTContext's allocator.
744///
745/// This placement form of operator new uses the ASTContext's allocator for
746/// obtaining memory. It is a non-throwing new, which means that it returns
747/// null on error. (If that is what the allocator does. The current does, so if
748/// this ever changes, this operator will have to be changed, too.)
749/// Usage looks like this (assuming there's an ASTContext 'Context' in scope):
750/// @code
751/// // Default alignment (16)
752/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
753/// // Specific alignment
754/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments);
755/// @endcode
756/// Please note that you cannot use delete on the pointer; it must be
757/// deallocated using an explicit destructor call followed by
758/// @c Context.Deallocate(Ptr).
759///
760/// @param Bytes The number of bytes to allocate. Calculated by the compiler.
761/// @param C The ASTContext that provides the allocator.
762/// @param Alignment The alignment of the allocated memory (if the underlying
763///                  allocator supports it).
764/// @return The allocated memory. Could be NULL.
765inline void *operator new(size_t Bytes, clang::ASTContext &C,
766                          size_t Alignment = 16) throw () {
767  return C.Allocate(Bytes, Alignment);
768}
769/// @brief Placement delete companion to the new above.
770///
771/// This operator is just a companion to the new above. There is no way of
772/// invoking it directly; see the new operator for more details. This operator
773/// is called implicitly by the compiler if a placement new expression using
774/// the ASTContext throws in the object constructor.
775inline void operator delete(void *Ptr, clang::ASTContext &C, size_t)
776              throw () {
777  C.Deallocate(Ptr);
778}
779
780/// This placement form of operator new[] uses the ASTContext's allocator for
781/// obtaining memory. It is a non-throwing new[], which means that it returns
782/// null on error.
783/// Usage looks like this (assuming there's an ASTContext 'Context' in scope):
784/// @code
785/// // Default alignment (16)
786/// char *data = new (Context) char[10];
787/// // Specific alignment
788/// char *data = new (Context, 8) char[10];
789/// @endcode
790/// Please note that you cannot use delete on the pointer; it must be
791/// deallocated using an explicit destructor call followed by
792/// @c Context.Deallocate(Ptr).
793///
794/// @param Bytes The number of bytes to allocate. Calculated by the compiler.
795/// @param C The ASTContext that provides the allocator.
796/// @param Alignment The alignment of the allocated memory (if the underlying
797///                  allocator supports it).
798/// @return The allocated memory. Could be NULL.
799inline void *operator new[](size_t Bytes, clang::ASTContext& C,
800                            size_t Alignment = 16) throw () {
801  return C.Allocate(Bytes, Alignment);
802}
803
804/// @brief Placement delete[] companion to the new[] above.
805///
806/// This operator is just a companion to the new[] above. There is no way of
807/// invoking it directly; see the new[] operator for more details. This operator
808/// is called implicitly by the compiler if a placement new[] expression using
809/// the ASTContext throws in the object constructor.
810inline void operator delete[](void *Ptr, clang::ASTContext &C) throw () {
811  C.Deallocate(Ptr);
812}
813
814#endif
815