DeclBase.h revision 074149e11baf5f7db12f84efd5c34ba6e35d5cdf 
1//===-- DeclBase.h - Base Classes for representing declarations *- 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 Decl and DeclContext interfaces.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_DECLBASE_H
15#define LLVM_CLANG_AST_DECLBASE_H
16
17#include "clang/AST/Attr.h"
18#include "clang/AST/Type.h"
19#include "clang/Basic/SourceLocation.h"
20#include "llvm/ADT/PointerIntPair.h"
21#include <vector>
22
23namespace clang {
24class DeclContext;
25class TranslationUnitDecl;
26class NamespaceDecl;
27class NamedDecl;
28class ScopedDecl;
29class FunctionDecl;
30class CXXRecordDecl;
31class EnumDecl;
32class ObjCMethodDecl;
33class ObjCInterfaceDecl;
34class LinkageSpecDecl;
35class BlockDecl;
36class DeclarationName;
37
38/// Decl - This represents one declaration (or definition), e.g. a variable,
39/// typedef, function, struct, etc.
40///
41class Decl {
42public:
43  enum Kind {
44    // This lists the concrete classes of Decl in order of the inheritance
45    // hierarchy.  This allows us to do efficient classof tests based on the
46    // enums below.   The commented out names are abstract class names.
47    // [DeclContext] indicates that the class also inherits from DeclContext.
48
49    // Decl
50         TranslationUnit,  // [DeclContext]
51    //   NamedDecl
52           OverloadedFunction,
53           ObjCCategory,
54           ObjCCategoryImpl,
55           ObjCImplementation,
56           ObjCMethod,  // [DeclContext]
57           ObjCProtocol,
58           ObjCProperty,
59    //     ScopedDecl
60             Field,
61               ObjCIvar,
62               ObjCAtDefsField,
63             Namespace,  // [DeclContext]
64    //       TypeDecl
65               Typedef,
66    //         TagDecl
67                 Enum,  // [DeclContext]
68                 Record, // [DeclContext]
69                   CXXRecord,
70 	       TemplateTypeParm,
71    //       ValueDecl
72               EnumConstant,
73               Function,  // [DeclContext]
74                 CXXMethod,
75                   CXXConstructor,
76                   CXXDestructor,
77                   CXXConversion,
78               Var,
79                 ImplicitParam,
80                 CXXClassVar,
81                 ParmVar,
82                   OriginalParmVar,
83  	         NonTypeTemplateParm,
84             LinkageSpec, // [DeclContext]
85           ObjCInterface,  // [DeclContext]
86           ObjCCompatibleAlias,
87           ObjCClass,
88           ObjCForwardProtocol,
89           ObjCPropertyImpl,
90         FileScopeAsm,
91	     Block, // [DeclContext]
92
93    // For each non-leaf class, we now define a mapping to the first/last member
94    // of the class, to allow efficient classof.
95    NamedFirst     = OverloadedFunction , NamedLast     = NonTypeTemplateParm,
96    FieldFirst     = Field        , FieldLast     = ObjCAtDefsField,
97    ScopedFirst    = Field        , ScopedLast    = LinkageSpec,
98    TypeFirst      = Typedef      , TypeLast      = TemplateTypeParm,
99    TagFirst       = Enum         , TagLast       = CXXRecord,
100    RecordFirst    = Record       , RecordLast    = CXXRecord,
101    ValueFirst     = EnumConstant , ValueLast     = NonTypeTemplateParm,
102    FunctionFirst  = Function     , FunctionLast  = CXXConversion,
103    VarFirst       = Var          , VarLast       = NonTypeTemplateParm
104  };
105
106  /// IdentifierNamespace - According to C99 6.2.3, there are four namespaces,
107  /// labels, tags, members and ordinary identifiers. These are meant
108  /// as bitmasks, so that searches in C++ can look into the "tag" namespace
109  /// during ordinary lookup.
110  enum IdentifierNamespace {
111    IDNS_Label = 0x1,
112    IDNS_Tag = 0x2,
113    IDNS_Member = 0x4,
114    IDNS_Ordinary = 0x8
115  };
116
117  /// ObjCDeclQualifier - Qualifier used on types in method declarations
118  /// for remote messaging. They are meant for the arguments though and
119  /// applied to the Decls (ObjCMethodDecl and ParmVarDecl).
120  enum ObjCDeclQualifier {
121    OBJC_TQ_None = 0x0,
122    OBJC_TQ_In = 0x1,
123    OBJC_TQ_Inout = 0x2,
124    OBJC_TQ_Out = 0x4,
125    OBJC_TQ_Bycopy = 0x8,
126    OBJC_TQ_Byref = 0x10,
127    OBJC_TQ_Oneway = 0x20
128  };
129
130private:
131  /// Loc - The location that this decl.
132  SourceLocation Loc;
133
134  /// DeclKind - This indicates which class this is.
135  Kind DeclKind   :  8;
136
137  /// InvalidDecl - This indicates a semantic error occurred.
138  unsigned int InvalidDecl :  1;
139
140  /// HasAttrs - This indicates whether the decl has attributes or not.
141  unsigned int HasAttrs : 1;
142
143 protected:
144  /// Access - Used by C++ decls for the access specifier.
145  // NOTE: VC++ treats enums as signed, avoid using the AccessSpecifier enum
146  unsigned Access : 2;
147  friend class CXXClassMemberWrapper;
148
149  Decl(Kind DK, SourceLocation L) : Loc(L), DeclKind(DK), InvalidDecl(0),
150    HasAttrs(false) {
151    if (Decl::CollectingStats()) addDeclKind(DK);
152  }
153
154  virtual ~Decl();
155
156public:
157  SourceLocation getLocation() const { return Loc; }
158  void setLocation(SourceLocation L) { Loc = L; }
159
160  Kind getKind() const { return DeclKind; }
161  const char *getDeclKindName() const;
162
163  void addAttr(Attr *attr);
164  const Attr *getAttrs() const;
165  void swapAttrs(Decl *D);
166  void invalidateAttrs();
167
168  template<typename T> const T *getAttr() const {
169    for (const Attr *attr = getAttrs(); attr; attr = attr->getNext())
170      if (const T *V = dyn_cast<T>(attr))
171        return V;
172
173    return 0;
174  }
175
176  /// setInvalidDecl - Indicates the Decl had a semantic error. This
177  /// allows for graceful error recovery.
178  void setInvalidDecl() { InvalidDecl = 1; }
179  bool isInvalidDecl() const { return (bool) InvalidDecl; }
180
181  IdentifierNamespace getIdentifierNamespace() const {
182    switch (DeclKind) {
183    default:
184      if (DeclKind >= FunctionFirst && DeclKind <= FunctionLast)
185        return IDNS_Ordinary;
186      assert(0 && "Unknown decl kind!");
187    case ImplicitParam:
188    case Typedef:
189    case Var:
190    case ParmVar:
191    case OriginalParmVar:
192    case EnumConstant:
193    case NonTypeTemplateParm:
194    case Field:
195    case ObjCAtDefsField:
196    case ObjCIvar:
197    case ObjCInterface:
198    case ObjCCompatibleAlias:
199    case OverloadedFunction:
200    case CXXMethod:
201    case CXXConversion:
202    case CXXClassVar:
203      return IDNS_Ordinary;
204    case Record:
205    case CXXRecord:
206    case TemplateTypeParm:
207    case Enum:
208      return IDNS_Tag;
209    case Namespace:
210      return IdentifierNamespace(IDNS_Tag | IDNS_Ordinary);
211    }
212  }
213
214  // getBody - If this Decl represents a declaration for a body of code,
215  //  such as a function or method definition, this method returns the top-level
216  //  Stmt* of that body.  Otherwise this method returns null.
217  virtual Stmt* getBody() const { return 0; }
218
219  // global temp stats (until we have a per-module visitor)
220  static void addDeclKind(Kind k);
221  static bool CollectingStats(bool Enable = false);
222  static void PrintStats();
223
224  /// isTemplateParameter - Determines whether this declartion is a
225  /// template parameter.
226  bool isTemplateParameter() const;
227
228  // Implement isa/cast/dyncast/etc.
229  static bool classof(const Decl *) { return true; }
230  static DeclContext *castToDeclContext(const Decl *);
231  static Decl *castFromDeclContext(const DeclContext *);
232
233  /// Emit - Serialize this Decl to Bitcode.
234  void Emit(llvm::Serializer& S) const;
235
236  /// Create - Deserialize a Decl from Bitcode.
237  static Decl* Create(llvm::Deserializer& D, ASTContext& C);
238
239  /// Destroy - Call destructors and release memory.
240  virtual void Destroy(ASTContext& C);
241
242protected:
243  /// EmitImpl - Provides the subclass-specific serialization logic for
244  ///   serializing out a decl.
245  virtual void EmitImpl(llvm::Serializer& S) const {
246    // FIXME: This will eventually be a pure virtual function.
247    assert (false && "Not implemented.");
248  }
249
250  void EmitInRec(llvm::Serializer& S) const;
251  void ReadInRec(llvm::Deserializer& D, ASTContext& C);
252};
253
254/// DeclContext - This is used only as base class of specific decl types that
255/// can act as declaration contexts. These decls are:
256///
257///   TranslationUnitDecl
258///   NamespaceDecl
259///   FunctionDecl
260///   RecordDecl/CXXRecordDecl
261///   EnumDecl
262///   ObjCMethodDecl
263///   ObjCInterfaceDecl
264///   LinkageSpecDecl
265///   BlockDecl
266class DeclContext {
267  /// DeclKind - This indicates which class this is.
268  Decl::Kind DeclKind   :  8;
269
270  /// LookupPtrKind - Describes what kind of pointer LookupPtr
271  /// actually is.
272  enum LookupPtrKind {
273    /// LookupIsMap - Indicates that LookupPtr is actually a map.
274    LookupIsMap = 7
275  };
276
277  /// LookupPtr - Pointer to a data structure used to lookup
278  /// declarations within this context. If the context contains fewer
279  /// than seven declarations, the number of declarations is provided
280  /// in the 3 lowest-order bits and the upper bits are treated as a
281  /// pointer to an array of ScopedDecl pointers. If the context
282  /// contains seven or more declarations, the upper bits are treated
283  /// as a pointer to a DenseMap<DeclarationName, std::vector<ScopedDecl>>.
284  /// FIXME: We need a better data structure for this.
285  llvm::PointerIntPair<void*, 3> LookupPtr;
286
287  /// Decls - Contains all of the declarations that are defined inside
288  /// this declaration context.
289  std::vector<ScopedDecl*> Decls;
290
291  // Used in the CastTo template to get the DeclKind
292  // from a Decl or a DeclContext. DeclContext doesn't have a getKind() method
293  // to avoid 'ambiguous access' compiler errors.
294  template<typename T> struct KindTrait {
295    static Decl::Kind getKind(const T *D) { return D->getKind(); }
296  };
297
298  // Used only by the ToDecl and FromDecl methods
299  template<typename To, typename From>
300  static To *CastTo(const From *D) {
301    Decl::Kind DK = KindTrait<From>::getKind(D);
302    switch(DK) {
303      case Decl::TranslationUnit:
304        return static_cast<TranslationUnitDecl*>(const_cast<From*>(D));
305      case Decl::Namespace:
306        return static_cast<NamespaceDecl*>(const_cast<From*>(D));
307      case Decl::Enum:
308        return static_cast<EnumDecl*>(const_cast<From*>(D));
309      case Decl::Record:
310        return static_cast<RecordDecl*>(const_cast<From*>(D));
311      case Decl::CXXRecord:
312        return static_cast<CXXRecordDecl*>(const_cast<From*>(D));
313      case Decl::ObjCMethod:
314        return static_cast<ObjCMethodDecl*>(const_cast<From*>(D));
315      case Decl::ObjCInterface:
316        return static_cast<ObjCInterfaceDecl*>(const_cast<From*>(D));
317      case Decl::LinkageSpec:
318        return static_cast<LinkageSpecDecl*>(const_cast<From*>(D));
319      case Decl::Block:
320        return static_cast<BlockDecl*>(const_cast<From*>(D));
321      default:
322        if (DK >= Decl::FunctionFirst && DK <= Decl::FunctionLast)
323          return static_cast<FunctionDecl*>(const_cast<From*>(D));
324
325        assert(false && "a decl that inherits DeclContext isn't handled");
326        return 0;
327    }
328  }
329
330  /// isLookupMap - Determine if the lookup structure is a
331  /// DenseMap. Othewise, it is an array.
332  bool isLookupMap() const { return LookupPtr.getInt() == LookupIsMap; }
333
334protected:
335  DeclContext(Decl::Kind K) : DeclKind(K), LookupPtr() {
336  }
337
338  void DestroyDecls(ASTContext &C);
339
340public:
341  ~DeclContext();
342
343  /// getParent - Returns the containing DeclContext if this is a ScopedDecl,
344  /// else returns NULL.
345  const DeclContext *getParent() const;
346  DeclContext *getParent() {
347    return const_cast<DeclContext*>(
348                             const_cast<const DeclContext*>(this)->getParent());
349  }
350
351  /// getLexicalParent - Returns the containing lexical DeclContext. May be
352  /// different from getParent, e.g.:
353  ///
354  ///   namespace A {
355  ///      struct S;
356  ///   }
357  ///   struct A::S {}; // getParent() == namespace 'A'
358  ///                   // getLexicalParent() == translation unit
359  ///
360  const DeclContext *getLexicalParent() const;
361  DeclContext *getLexicalParent() {
362    return const_cast<DeclContext*>(
363                      const_cast<const DeclContext*>(this)->getLexicalParent());
364  }
365
366  bool isFunctionOrMethod() const {
367    switch (DeclKind) {
368      case Decl::Block:
369      case Decl::ObjCMethod:
370        return true;
371
372      default:
373       if (DeclKind >= Decl::FunctionFirst && DeclKind <= Decl::FunctionLast)
374         return true;
375        return false;
376    }
377  }
378
379  bool isFileContext() const {
380    return DeclKind == Decl::TranslationUnit || DeclKind == Decl::Namespace;
381  }
382
383  bool isCXXRecord() const {
384    return DeclKind == Decl::CXXRecord;
385  }
386
387  bool isNamespace() const {
388    return DeclKind == Decl::Namespace;
389  }
390
391  /// isTransparentContext - Determines whether this context is a
392  /// "transparent" context, meaning that the members declared in this
393  /// context are semantically declared in the nearest enclosing
394  /// non-transparent (opaque) context but are lexically declared in
395  /// this context. For example, consider the enumerators of an
396  /// enumeration type:
397  /// @code
398  /// enum E {
399  ///   Val1
400  /// };
401  /// @endcode
402  /// Here, E is a transparent context, so its enumerator (Val1) will
403  /// appear (semantically) that it is in the same context of E.
404  /// Examples of transparent contexts include: enumerations (except for
405  /// C++0x scoped enums), C++ linkage specifications, and C++0x
406  /// inline namespaces.
407  bool isTransparentContext() const;
408
409  bool Encloses(DeclContext *DC) const {
410    for (; DC; DC = DC->getParent())
411      if (DC == this)
412        return true;
413    return false;
414  }
415
416  /// getPrimaryContext - There may be many different
417  /// declarations of the same entity (including forward declarations
418  /// of classes, multiple definitions of namespaces, etc.), each with
419  /// a different set of declarations. This routine returns the
420  /// "primary" DeclContext structure, which will contain the
421  /// information needed to perform name lookup into this context.
422  DeclContext *getPrimaryContext(ASTContext &Context);
423
424  /// getNextContext - If this is a DeclContext that may have other
425  /// DeclContexts that are semantically connected but syntactically
426  /// different, such as C++ namespaces, this routine retrieves the
427  /// next DeclContext in the link. Iteration through the chain of
428  /// DeclContexts should begin at the primary DeclContext and
429  /// continue until this function returns NULL. For example, given:
430  /// @code
431  /// namespace N {
432  ///   int x;
433  /// }
434  /// namespace N {
435  ///   int y;
436  /// }
437  /// @endcode
438  /// The first occurrence of namespace N will be the primary
439  /// DeclContext. Its getNextContext will return the second
440  /// occurrence of namespace N.
441  DeclContext *getNextContext();
442
443  /// decl_iterator - Iterates through the declarations stored
444  /// within this context.
445  typedef std::vector<ScopedDecl*>::const_iterator decl_iterator;
446
447  /// decls_begin/decls_end - Iterate over the declarations stored in
448  /// this context.
449  decl_iterator decls_begin() const { return Decls.begin(); }
450  decl_iterator decls_end()   const { return Decls.end(); }
451
452  /// addDecl - Add the declaration D to this scope. Note that
453  /// declarations are added at the beginning of the declaration
454  /// chain, so reverseDeclChain() should be called after all
455  /// declarations have been added. If AllowLookup, also adds this
456  /// declaration into data structure for name lookup.
457  void addDecl(ASTContext &Context, ScopedDecl *D, bool AllowLookup = true);
458
459  void buildLookup(ASTContext &Context, DeclContext *DCtx);
460
461  /// lookup_iterator - An iterator that provides access to the results
462  /// of looking up a name within this context.
463  typedef ScopedDecl **lookup_iterator;
464
465  /// lookup_const_iterator - An iterator that provides non-mutable
466  /// access to the results of lookup up a name within this context.
467  typedef ScopedDecl * const * lookup_const_iterator;
468
469  typedef std::pair<lookup_iterator, lookup_iterator> lookup_result;
470  typedef std::pair<lookup_const_iterator, lookup_const_iterator>
471    lookup_const_result;
472
473  /// lookup - Find the declarations (if any) with the given Name in
474  /// this context. Returns a range of iterators that contains all of
475  /// the declarations with this name (which may be 0, 1, or 2
476  /// declarations). If two declarations are returned, the declaration
477  /// in the "ordinary" identifier namespace will precede the
478  /// declaration in the "tag" identifier namespace (e.g., values
479  /// before types). Note that this routine will not look into parent
480  /// contexts.
481  lookup_result lookup(ASTContext &Context, DeclarationName Name);
482  lookup_const_result lookup(ASTContext &Context, DeclarationName Name) const;
483
484  /// insert - Insert the declaration D into this context. Up to two
485  /// declarations with the same name can be inserted into a single
486  /// declaration context, one in the "tag" namespace (e.g., for
487  /// classes and enums) and one in the "ordinary" namespaces (e.g.,
488  /// for variables, functions, and other values). Note that, if there
489  /// is already a declaration with the same name and identifier
490  /// namespace, D will replace it. It is up to the caller to ensure
491  /// that this replacement is semantically correct, e.g., that
492  /// declarations are only replaced by later declarations of the same
493  /// entity and not a declaration of some other kind of entity.
494  void insert(ASTContext &Context, ScopedDecl *D);
495
496  static bool classof(const Decl *D) {
497    switch (D->getKind()) {
498      case Decl::TranslationUnit:
499      case Decl::Namespace:
500      case Decl::Enum:
501      case Decl::Record:
502      case Decl::CXXRecord:
503      case Decl::ObjCMethod:
504      case Decl::ObjCInterface:
505      case Decl::LinkageSpec:
506      case Decl::Block:
507        return true;
508      default:
509        if (D->getKind() >= Decl::FunctionFirst &&
510            D->getKind() <= Decl::FunctionLast)
511          return true;
512        return false;
513    }
514  }
515  static bool classof(const DeclContext *D) { return true; }
516  static bool classof(const TranslationUnitDecl *D) { return true; }
517  static bool classof(const NamespaceDecl *D) { return true; }
518  static bool classof(const FunctionDecl *D) { return true; }
519  static bool classof(const RecordDecl *D) { return true; }
520  static bool classof(const CXXRecordDecl *D) { return true; }
521  static bool classof(const EnumDecl *D) { return true; }
522  static bool classof(const ObjCMethodDecl *D) { return true; }
523  static bool classof(const ObjCInterfaceDecl *D) { return true; }
524  static bool classof(const LinkageSpecDecl *D) { return true; }
525  static bool classof(const BlockDecl *D) { return true; }
526
527private:
528  void insertImpl(ScopedDecl *D);
529
530  void EmitOutRec(llvm::Serializer& S) const;
531  void ReadOutRec(llvm::Deserializer& D, ASTContext& C);
532
533  friend class Decl;
534};
535
536template<> struct DeclContext::KindTrait<DeclContext> {
537  static Decl::Kind getKind(const DeclContext *D) { return D->DeclKind; }
538};
539
540inline bool Decl::isTemplateParameter() const {
541  return getKind() == TemplateTypeParm || getKind() == NonTypeTemplateParm;
542}
543
544
545} // end clang.
546
547namespace llvm {
548
549/// Implement a isa_impl_wrap specialization to check whether a DeclContext is
550/// a specific Decl.
551template<class ToTy>
552struct isa_impl_wrap<ToTy,
553                     const ::clang::DeclContext,const ::clang::DeclContext> {
554  static bool doit(const ::clang::DeclContext &Val) {
555    return ToTy::classof(::clang::Decl::castFromDeclContext(&Val));
556  }
557};
558template<class ToTy>
559struct isa_impl_wrap<ToTy, ::clang::DeclContext, ::clang::DeclContext>
560  : public isa_impl_wrap<ToTy,
561                      const ::clang::DeclContext,const ::clang::DeclContext> {};
562
563/// Implement cast_convert_val for Decl -> DeclContext conversions.
564template<class FromTy>
565struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
566  static ::clang::DeclContext &doit(const FromTy &Val) {
567    return *FromTy::castToDeclContext(&Val);
568  }
569};
570
571template<class FromTy>
572struct cast_convert_val< ::clang::DeclContext, FromTy*, FromTy*> {
573  static ::clang::DeclContext *doit(const FromTy *Val) {
574    return FromTy::castToDeclContext(Val);
575  }
576};
577
578template<class FromTy>
579struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
580  static const ::clang::DeclContext &doit(const FromTy &Val) {
581    return *FromTy::castToDeclContext(&Val);
582  }
583};
584
585template<class FromTy>
586struct cast_convert_val< const ::clang::DeclContext, FromTy*, FromTy*> {
587  static const ::clang::DeclContext *doit(const FromTy *Val) {
588    return FromTy::castToDeclContext(Val);
589  }
590};
591
592/// Implement cast_convert_val for DeclContext -> Decl conversions.
593template<class ToTy>
594struct cast_convert_val<ToTy,
595                        const ::clang::DeclContext,const ::clang::DeclContext> {
596  static ToTy &doit(const ::clang::DeclContext &Val) {
597    return *reinterpret_cast<ToTy*>(ToTy::castFromDeclContext(&Val));
598  }
599};
600template<class ToTy>
601struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext>
602  : public cast_convert_val<ToTy,
603                      const ::clang::DeclContext,const ::clang::DeclContext> {};
604
605template<class ToTy>
606struct cast_convert_val<ToTy,
607                     const ::clang::DeclContext*, const ::clang::DeclContext*> {
608  static ToTy *doit(const ::clang::DeclContext *Val) {
609    return reinterpret_cast<ToTy*>(ToTy::castFromDeclContext(Val));
610  }
611};
612template<class ToTy>
613struct cast_convert_val<ToTy, ::clang::DeclContext*, ::clang::DeclContext*>
614  : public cast_convert_val<ToTy,
615                    const ::clang::DeclContext*,const ::clang::DeclContext*> {};
616
617} // end namespace llvm
618
619#endif
620