• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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/AttrIterator.h"
18 #include "clang/AST/DeclarationName.h"
19 #include "clang/Basic/Linkage.h"
20 #include "clang/Basic/Specifiers.h"
21 #include "llvm/ADT/PointerUnion.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/PrettyStackTrace.h"
24 
25 namespace clang {
26 class ASTMutationListener;
27 class BlockDecl;
28 class CXXRecordDecl;
29 class CompoundStmt;
30 class DeclContext;
31 class DeclarationName;
32 class DependentDiagnostic;
33 class EnumDecl;
34 class FunctionDecl;
35 class LinkageComputer;
36 class LinkageSpecDecl;
37 class Module;
38 class NamedDecl;
39 class NamespaceDecl;
40 class ObjCCategoryDecl;
41 class ObjCCategoryImplDecl;
42 class ObjCContainerDecl;
43 class ObjCImplDecl;
44 class ObjCImplementationDecl;
45 class ObjCInterfaceDecl;
46 class ObjCMethodDecl;
47 class ObjCProtocolDecl;
48 struct PrintingPolicy;
49 class Stmt;
50 class StoredDeclsMap;
51 class TranslationUnitDecl;
52 class UsingDirectiveDecl;
53 }
54 
55 namespace llvm {
56 // DeclContext* is only 4-byte aligned on 32-bit systems.
57 template<>
58   class PointerLikeTypeTraits<clang::DeclContext*> {
59   typedef clang::DeclContext* PT;
60 public:
getAsVoidPointer(PT P)61   static inline void *getAsVoidPointer(PT P) { return P; }
getFromVoidPointer(void * P)62   static inline PT getFromVoidPointer(void *P) {
63     return static_cast<PT>(P);
64   }
65   enum { NumLowBitsAvailable = 2 };
66 };
67 }
68 
69 namespace clang {
70 
71   /// \brief Captures the result of checking the availability of a
72   /// declaration.
73   enum AvailabilityResult {
74     AR_Available = 0,
75     AR_NotYetIntroduced,
76     AR_Deprecated,
77     AR_Unavailable
78   };
79 
80 /// Decl - This represents one declaration (or definition), e.g. a variable,
81 /// typedef, function, struct, etc.
82 ///
83 class Decl {
84 public:
85   /// \brief Lists the kind of concrete classes of Decl.
86   enum Kind {
87 #define DECL(DERIVED, BASE) DERIVED,
88 #define ABSTRACT_DECL(DECL)
89 #define DECL_RANGE(BASE, START, END) \
90         first##BASE = START, last##BASE = END,
91 #define LAST_DECL_RANGE(BASE, START, END) \
92         first##BASE = START, last##BASE = END
93 #include "clang/AST/DeclNodes.inc"
94   };
95 
96   /// \brief A placeholder type used to construct an empty shell of a
97   /// decl-derived type that will be filled in later (e.g., by some
98   /// deserialization method).
99   struct EmptyShell { };
100 
101   /// IdentifierNamespace - The different namespaces in which
102   /// declarations may appear.  According to C99 6.2.3, there are
103   /// four namespaces, labels, tags, members and ordinary
104   /// identifiers.  C++ describes lookup completely differently:
105   /// certain lookups merely "ignore" certain kinds of declarations,
106   /// usually based on whether the declaration is of a type, etc.
107   ///
108   /// These are meant as bitmasks, so that searches in
109   /// C++ can look into the "tag" namespace during ordinary lookup.
110   ///
111   /// Decl currently provides 15 bits of IDNS bits.
112   enum IdentifierNamespace {
113     /// Labels, declared with 'x:' and referenced with 'goto x'.
114     IDNS_Label               = 0x0001,
115 
116     /// Tags, declared with 'struct foo;' and referenced with
117     /// 'struct foo'.  All tags are also types.  This is what
118     /// elaborated-type-specifiers look for in C.
119     IDNS_Tag                 = 0x0002,
120 
121     /// Types, declared with 'struct foo', typedefs, etc.
122     /// This is what elaborated-type-specifiers look for in C++,
123     /// but note that it's ill-formed to find a non-tag.
124     IDNS_Type                = 0x0004,
125 
126     /// Members, declared with object declarations within tag
127     /// definitions.  In C, these can only be found by "qualified"
128     /// lookup in member expressions.  In C++, they're found by
129     /// normal lookup.
130     IDNS_Member              = 0x0008,
131 
132     /// Namespaces, declared with 'namespace foo {}'.
133     /// Lookup for nested-name-specifiers find these.
134     IDNS_Namespace           = 0x0010,
135 
136     /// Ordinary names.  In C, everything that's not a label, tag,
137     /// or member ends up here.
138     IDNS_Ordinary            = 0x0020,
139 
140     /// Objective C \@protocol.
141     IDNS_ObjCProtocol        = 0x0040,
142 
143     /// This declaration is a friend function.  A friend function
144     /// declaration is always in this namespace but may also be in
145     /// IDNS_Ordinary if it was previously declared.
146     IDNS_OrdinaryFriend      = 0x0080,
147 
148     /// This declaration is a friend class.  A friend class
149     /// declaration is always in this namespace but may also be in
150     /// IDNS_Tag|IDNS_Type if it was previously declared.
151     IDNS_TagFriend           = 0x0100,
152 
153     /// This declaration is a using declaration.  A using declaration
154     /// *introduces* a number of other declarations into the current
155     /// scope, and those declarations use the IDNS of their targets,
156     /// but the actual using declarations go in this namespace.
157     IDNS_Using               = 0x0200,
158 
159     /// This declaration is a C++ operator declared in a non-class
160     /// context.  All such operators are also in IDNS_Ordinary.
161     /// C++ lexical operator lookup looks for these.
162     IDNS_NonMemberOperator   = 0x0400
163   };
164 
165   /// ObjCDeclQualifier - 'Qualifiers' written next to the return and
166   /// parameter types in method declarations.  Other than remembering
167   /// them and mangling them into the method's signature string, these
168   /// are ignored by the compiler; they are consumed by certain
169   /// remote-messaging frameworks.
170   ///
171   /// in, inout, and out are mutually exclusive and apply only to
172   /// method parameters.  bycopy and byref are mutually exclusive and
173   /// apply only to method parameters (?).  oneway applies only to
174   /// results.  All of these expect their corresponding parameter to
175   /// have a particular type.  None of this is currently enforced by
176   /// clang.
177   ///
178   /// This should be kept in sync with ObjCDeclSpec::ObjCDeclQualifier.
179   enum ObjCDeclQualifier {
180     OBJC_TQ_None = 0x0,
181     OBJC_TQ_In = 0x1,
182     OBJC_TQ_Inout = 0x2,
183     OBJC_TQ_Out = 0x4,
184     OBJC_TQ_Bycopy = 0x8,
185     OBJC_TQ_Byref = 0x10,
186     OBJC_TQ_Oneway = 0x20
187   };
188 
189 protected:
190   // Enumeration values used in the bits stored in NextInContextAndBits.
191   enum {
192     /// \brief Whether this declaration is a top-level declaration (function,
193     /// global variable, etc.) that is lexically inside an objc container
194     /// definition.
195     TopLevelDeclInObjCContainerFlag = 0x01,
196 
197     /// \brief Whether this declaration is private to the module in which it was
198     /// defined.
199     ModulePrivateFlag = 0x02
200   };
201 
202   /// \brief The next declaration within the same lexical
203   /// DeclContext. These pointers form the linked list that is
204   /// traversed via DeclContext's decls_begin()/decls_end().
205   ///
206   /// The extra two bits are used for the TopLevelDeclInObjCContainer and
207   /// ModulePrivate bits.
208   llvm::PointerIntPair<Decl *, 2, unsigned> NextInContextAndBits;
209 
210 private:
211   friend class DeclContext;
212 
213   struct MultipleDC {
214     DeclContext *SemanticDC;
215     DeclContext *LexicalDC;
216   };
217 
218 
219   /// DeclCtx - Holds either a DeclContext* or a MultipleDC*.
220   /// For declarations that don't contain C++ scope specifiers, it contains
221   /// the DeclContext where the Decl was declared.
222   /// For declarations with C++ scope specifiers, it contains a MultipleDC*
223   /// with the context where it semantically belongs (SemanticDC) and the
224   /// context where it was lexically declared (LexicalDC).
225   /// e.g.:
226   ///
227   ///   namespace A {
228   ///      void f(); // SemanticDC == LexicalDC == 'namespace A'
229   ///   }
230   ///   void A::f(); // SemanticDC == namespace 'A'
231   ///                // LexicalDC == global namespace
232   llvm::PointerUnion<DeclContext*, MultipleDC*> DeclCtx;
233 
isInSemaDC()234   inline bool isInSemaDC() const    { return DeclCtx.is<DeclContext*>(); }
isOutOfSemaDC()235   inline bool isOutOfSemaDC() const { return DeclCtx.is<MultipleDC*>(); }
getMultipleDC()236   inline MultipleDC *getMultipleDC() const {
237     return DeclCtx.get<MultipleDC*>();
238   }
getSemanticDC()239   inline DeclContext *getSemanticDC() const {
240     return DeclCtx.get<DeclContext*>();
241   }
242 
243   /// Loc - The location of this decl.
244   SourceLocation Loc;
245 
246   /// DeclKind - This indicates which class this is.
247   unsigned DeclKind : 8;
248 
249   /// InvalidDecl - This indicates a semantic error occurred.
250   unsigned InvalidDecl :  1;
251 
252   /// HasAttrs - This indicates whether the decl has attributes or not.
253   unsigned HasAttrs : 1;
254 
255   /// Implicit - Whether this declaration was implicitly generated by
256   /// the implementation rather than explicitly written by the user.
257   unsigned Implicit : 1;
258 
259   /// \brief Whether this declaration was "used", meaning that a definition is
260   /// required.
261   unsigned Used : 1;
262 
263   /// \brief Whether this declaration was "referenced".
264   /// The difference with 'Used' is whether the reference appears in a
265   /// evaluated context or not, e.g. functions used in uninstantiated templates
266   /// are regarded as "referenced" but not "used".
267   unsigned Referenced : 1;
268 
269   /// \brief Whether statistic collection is enabled.
270   static bool StatisticsEnabled;
271 
272 protected:
273   /// Access - Used by C++ decls for the access specifier.
274   // NOTE: VC++ treats enums as signed, avoid using the AccessSpecifier enum
275   unsigned Access : 2;
276   friend class CXXClassMemberWrapper;
277 
278   /// \brief Whether this declaration was loaded from an AST file.
279   unsigned FromASTFile : 1;
280 
281   /// \brief Whether this declaration is hidden from normal name lookup, e.g.,
282   /// because it is was loaded from an AST file is either module-private or
283   /// because its submodule has not been made visible.
284   unsigned Hidden : 1;
285 
286   /// IdentifierNamespace - This specifies what IDNS_* namespace this lives in.
287   unsigned IdentifierNamespace : 12;
288 
289   /// \brief If 0, we have not computed the linkage of this declaration.
290   /// Otherwise, it is the linkage + 1.
291   mutable unsigned CacheValidAndLinkage : 3;
292 
293   friend class ASTDeclWriter;
294   friend class ASTDeclReader;
295   friend class ASTReader;
296   friend class LinkageComputer;
297 
298   template<typename decl_type> friend class Redeclarable;
299 
300 private:
301   void CheckAccessDeclContext() const;
302 
303 protected:
304 
Decl(Kind DK,DeclContext * DC,SourceLocation L)305   Decl(Kind DK, DeclContext *DC, SourceLocation L)
306     : NextInContextAndBits(), DeclCtx(DC),
307       Loc(L), DeclKind(DK), InvalidDecl(0),
308       HasAttrs(false), Implicit(false), Used(false), Referenced(false),
309       Access(AS_none), FromASTFile(0), Hidden(0),
310       IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
311       CacheValidAndLinkage(0)
312   {
313     if (StatisticsEnabled) add(DK);
314   }
315 
Decl(Kind DK,EmptyShell Empty)316   Decl(Kind DK, EmptyShell Empty)
317     : NextInContextAndBits(), DeclKind(DK), InvalidDecl(0),
318       HasAttrs(false), Implicit(false), Used(false), Referenced(false),
319       Access(AS_none), FromASTFile(0), Hidden(0),
320       IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
321       CacheValidAndLinkage(0)
322   {
323     if (StatisticsEnabled) add(DK);
324   }
325 
326   virtual ~Decl();
327 
328   /// \brief Allocate memory for a deserialized declaration.
329   ///
330   /// This routine must be used to allocate memory for any declaration that is
331   /// deserialized from a module file.
332   ///
333   /// \param Context The context in which we will allocate memory.
334   /// \param ID The global ID of the deserialized declaration.
335   /// \param Size The size of the allocated object.
336   static void *AllocateDeserializedDecl(const ASTContext &Context,
337                                         unsigned ID,
338                                         unsigned Size);
339 
340   /// \brief Update a potentially out-of-date declaration.
341   void updateOutOfDate(IdentifierInfo &II) const;
342 
getCachedLinkage()343   Linkage getCachedLinkage() const {
344     return Linkage(CacheValidAndLinkage - 1);
345   }
346 
setCachedLinkage(Linkage L)347   void setCachedLinkage(Linkage L) const {
348     CacheValidAndLinkage = L + 1;
349   }
350 
hasCachedLinkage()351   bool hasCachedLinkage() const {
352     return CacheValidAndLinkage;
353   }
354 
355 public:
356 
357   /// \brief Source range that this declaration covers.
getSourceRange()358   virtual SourceRange getSourceRange() const LLVM_READONLY {
359     return SourceRange(getLocation(), getLocation());
360   }
getLocStart()361   SourceLocation getLocStart() const LLVM_READONLY {
362     return getSourceRange().getBegin();
363   }
getLocEnd()364   SourceLocation getLocEnd() const LLVM_READONLY {
365     return getSourceRange().getEnd();
366   }
367 
getLocation()368   SourceLocation getLocation() const { return Loc; }
setLocation(SourceLocation L)369   void setLocation(SourceLocation L) { Loc = L; }
370 
getKind()371   Kind getKind() const { return static_cast<Kind>(DeclKind); }
372   const char *getDeclKindName() const;
373 
getNextDeclInContext()374   Decl *getNextDeclInContext() { return NextInContextAndBits.getPointer(); }
getNextDeclInContext()375   const Decl *getNextDeclInContext() const {return NextInContextAndBits.getPointer();}
376 
getDeclContext()377   DeclContext *getDeclContext() {
378     if (isInSemaDC())
379       return getSemanticDC();
380     return getMultipleDC()->SemanticDC;
381   }
getDeclContext()382   const DeclContext *getDeclContext() const {
383     return const_cast<Decl*>(this)->getDeclContext();
384   }
385 
386   /// Find the innermost non-closure ancestor of this declaration,
387   /// walking up through blocks, lambdas, etc.  If that ancestor is
388   /// not a code context (!isFunctionOrMethod()), returns null.
389   ///
390   /// A declaration may be its own non-closure context.
391   Decl *getNonClosureContext();
getNonClosureContext()392   const Decl *getNonClosureContext() const {
393     return const_cast<Decl*>(this)->getNonClosureContext();
394   }
395 
396   TranslationUnitDecl *getTranslationUnitDecl();
getTranslationUnitDecl()397   const TranslationUnitDecl *getTranslationUnitDecl() const {
398     return const_cast<Decl*>(this)->getTranslationUnitDecl();
399   }
400 
401   bool isInAnonymousNamespace() const;
402 
403   ASTContext &getASTContext() const LLVM_READONLY;
404 
setAccess(AccessSpecifier AS)405   void setAccess(AccessSpecifier AS) {
406     Access = AS;
407 #ifndef NDEBUG
408     CheckAccessDeclContext();
409 #endif
410   }
411 
getAccess()412   AccessSpecifier getAccess() const {
413 #ifndef NDEBUG
414     CheckAccessDeclContext();
415 #endif
416     return AccessSpecifier(Access);
417   }
418 
419   /// \brief Retrieve the access specifier for this declaration, even though
420   /// it may not yet have been properly set.
getAccessUnsafe()421   AccessSpecifier getAccessUnsafe() const {
422     return AccessSpecifier(Access);
423   }
424 
hasAttrs()425   bool hasAttrs() const { return HasAttrs; }
setAttrs(const AttrVec & Attrs)426   void setAttrs(const AttrVec& Attrs) {
427     return setAttrsImpl(Attrs, getASTContext());
428   }
getAttrs()429   AttrVec &getAttrs() {
430     return const_cast<AttrVec&>(const_cast<const Decl*>(this)->getAttrs());
431   }
432   const AttrVec &getAttrs() const;
433   void dropAttrs();
434 
addAttr(Attr * A)435   void addAttr(Attr *A) {
436     if (hasAttrs())
437       getAttrs().push_back(A);
438     else
439       setAttrs(AttrVec(1, A));
440   }
441 
442   typedef AttrVec::const_iterator attr_iterator;
443 
444   // FIXME: Do not rely on iterators having comparable singular values.
445   //        Note that this should error out if they do not.
attr_begin()446   attr_iterator attr_begin() const {
447     return hasAttrs() ? getAttrs().begin() : 0;
448   }
attr_end()449   attr_iterator attr_end() const {
450     return hasAttrs() ? getAttrs().end() : 0;
451   }
452 
453   template <typename T>
dropAttr()454   void dropAttr() {
455     if (!HasAttrs) return;
456 
457     AttrVec &Vec = getAttrs();
458     Vec.erase(std::remove_if(Vec.begin(), Vec.end(), isa<T, Attr*>), Vec.end());
459 
460     if (Vec.empty())
461       HasAttrs = false;
462   }
463 
464   template <typename T>
specific_attr_begin()465   specific_attr_iterator<T> specific_attr_begin() const {
466     return specific_attr_iterator<T>(attr_begin());
467   }
468   template <typename T>
specific_attr_end()469   specific_attr_iterator<T> specific_attr_end() const {
470     return specific_attr_iterator<T>(attr_end());
471   }
472 
getAttr()473   template<typename T> T *getAttr() const {
474     return hasAttrs() ? getSpecificAttr<T>(getAttrs()) : 0;
475   }
hasAttr()476   template<typename T> bool hasAttr() const {
477     return hasAttrs() && hasSpecificAttr<T>(getAttrs());
478   }
479 
480   /// getMaxAlignment - return the maximum alignment specified by attributes
481   /// on this decl, 0 if there are none.
482   unsigned getMaxAlignment() const;
483 
484   /// setInvalidDecl - Indicates the Decl had a semantic error. This
485   /// allows for graceful error recovery.
486   void setInvalidDecl(bool Invalid = true);
isInvalidDecl()487   bool isInvalidDecl() const { return (bool) InvalidDecl; }
488 
489   /// isImplicit - Indicates whether the declaration was implicitly
490   /// generated by the implementation. If false, this declaration
491   /// was written explicitly in the source code.
isImplicit()492   bool isImplicit() const { return Implicit; }
493   void setImplicit(bool I = true) { Implicit = I; }
494 
495   /// \brief Whether this declaration was used, meaning that a definition
496   /// is required.
497   ///
498   /// \param CheckUsedAttr When true, also consider the "used" attribute
499   /// (in addition to the "used" bit set by \c setUsed()) when determining
500   /// whether the function is used.
501   bool isUsed(bool CheckUsedAttr = true) const;
502 
503   void setUsed(bool U = true) { Used = U; }
504 
505   /// \brief Whether this declaration was referenced.
506   bool isReferenced() const;
507 
508   void setReferenced(bool R = true) { Referenced = R; }
509 
510   /// \brief Whether this declaration is a top-level declaration (function,
511   /// global variable, etc.) that is lexically inside an objc container
512   /// definition.
isTopLevelDeclInObjCContainer()513   bool isTopLevelDeclInObjCContainer() const {
514     return NextInContextAndBits.getInt() & TopLevelDeclInObjCContainerFlag;
515   }
516 
517   void setTopLevelDeclInObjCContainer(bool V = true) {
518     unsigned Bits = NextInContextAndBits.getInt();
519     if (V)
520       Bits |= TopLevelDeclInObjCContainerFlag;
521     else
522       Bits &= ~TopLevelDeclInObjCContainerFlag;
523     NextInContextAndBits.setInt(Bits);
524   }
525 
526   /// \brief Whether this declaration was marked as being private to the
527   /// module in which it was defined.
isModulePrivate()528   bool isModulePrivate() const {
529     return NextInContextAndBits.getInt() & ModulePrivateFlag;
530   }
531 
532 protected:
533   /// \brief Specify whether this declaration was marked as being private
534   /// to the module in which it was defined.
535   void setModulePrivate(bool MP = true) {
536     unsigned Bits = NextInContextAndBits.getInt();
537     if (MP)
538       Bits |= ModulePrivateFlag;
539     else
540       Bits &= ~ModulePrivateFlag;
541     NextInContextAndBits.setInt(Bits);
542   }
543 
544   /// \brief Set the owning module ID.
setOwningModuleID(unsigned ID)545   void setOwningModuleID(unsigned ID) {
546     assert(isFromASTFile() && "Only works on a deserialized declaration");
547     *((unsigned*)this - 2) = ID;
548   }
549 
550 public:
551 
552   /// \brief Determine the availability of the given declaration.
553   ///
554   /// This routine will determine the most restrictive availability of
555   /// the given declaration (e.g., preferring 'unavailable' to
556   /// 'deprecated').
557   ///
558   /// \param Message If non-NULL and the result is not \c
559   /// AR_Available, will be set to a (possibly empty) message
560   /// describing why the declaration has not been introduced, is
561   /// deprecated, or is unavailable.
562   AvailabilityResult getAvailability(std::string *Message = 0) const;
563 
564   /// \brief Determine whether this declaration is marked 'deprecated'.
565   ///
566   /// \param Message If non-NULL and the declaration is deprecated,
567   /// this will be set to the message describing why the declaration
568   /// was deprecated (which may be empty).
569   bool isDeprecated(std::string *Message = 0) const {
570     return getAvailability(Message) == AR_Deprecated;
571   }
572 
573   /// \brief Determine whether this declaration is marked 'unavailable'.
574   ///
575   /// \param Message If non-NULL and the declaration is unavailable,
576   /// this will be set to the message describing why the declaration
577   /// was made unavailable (which may be empty).
578   bool isUnavailable(std::string *Message = 0) const {
579     return getAvailability(Message) == AR_Unavailable;
580   }
581 
582   /// \brief Determine whether this is a weak-imported symbol.
583   ///
584   /// Weak-imported symbols are typically marked with the
585   /// 'weak_import' attribute, but may also be marked with an
586   /// 'availability' attribute where we're targing a platform prior to
587   /// the introduction of this feature.
588   bool isWeakImported() const;
589 
590   /// \brief Determines whether this symbol can be weak-imported,
591   /// e.g., whether it would be well-formed to add the weak_import
592   /// attribute.
593   ///
594   /// \param IsDefinition Set to \c true to indicate that this
595   /// declaration cannot be weak-imported because it has a definition.
596   bool canBeWeakImported(bool &IsDefinition) const;
597 
598   /// \brief Determine whether this declaration came from an AST file (such as
599   /// a precompiled header or module) rather than having been parsed.
isFromASTFile()600   bool isFromASTFile() const { return FromASTFile; }
601 
602   /// \brief Retrieve the global declaration ID associated with this
603   /// declaration, which specifies where in the
getGlobalID()604   unsigned getGlobalID() const {
605     if (isFromASTFile())
606       return *((const unsigned*)this - 1);
607     return 0;
608   }
609 
610   /// \brief Retrieve the global ID of the module that owns this particular
611   /// declaration.
getOwningModuleID()612   unsigned getOwningModuleID() const {
613     if (isFromASTFile())
614       return *((const unsigned*)this - 2);
615 
616     return 0;
617   }
618 
619 private:
620   Module *getOwningModuleSlow() const;
621 
622 public:
getOwningModule()623   Module *getOwningModule() const {
624     if (!isFromASTFile())
625       return 0;
626 
627     return getOwningModuleSlow();
628   }
629 
getIdentifierNamespace()630   unsigned getIdentifierNamespace() const {
631     return IdentifierNamespace;
632   }
isInIdentifierNamespace(unsigned NS)633   bool isInIdentifierNamespace(unsigned NS) const {
634     return getIdentifierNamespace() & NS;
635   }
636   static unsigned getIdentifierNamespaceForKind(Kind DK);
637 
hasTagIdentifierNamespace()638   bool hasTagIdentifierNamespace() const {
639     return isTagIdentifierNamespace(getIdentifierNamespace());
640   }
isTagIdentifierNamespace(unsigned NS)641   static bool isTagIdentifierNamespace(unsigned NS) {
642     // TagDecls have Tag and Type set and may also have TagFriend.
643     return (NS & ~IDNS_TagFriend) == (IDNS_Tag | IDNS_Type);
644   }
645 
646   /// getLexicalDeclContext - The declaration context where this Decl was
647   /// lexically declared (LexicalDC). May be different from
648   /// getDeclContext() (SemanticDC).
649   /// e.g.:
650   ///
651   ///   namespace A {
652   ///      void f(); // SemanticDC == LexicalDC == 'namespace A'
653   ///   }
654   ///   void A::f(); // SemanticDC == namespace 'A'
655   ///                // LexicalDC == global namespace
getLexicalDeclContext()656   DeclContext *getLexicalDeclContext() {
657     if (isInSemaDC())
658       return getSemanticDC();
659     return getMultipleDC()->LexicalDC;
660   }
getLexicalDeclContext()661   const DeclContext *getLexicalDeclContext() const {
662     return const_cast<Decl*>(this)->getLexicalDeclContext();
663   }
664 
isOutOfLine()665   virtual bool isOutOfLine() const {
666     return getLexicalDeclContext() != getDeclContext();
667   }
668 
669   /// setDeclContext - Set both the semantic and lexical DeclContext
670   /// to DC.
671   void setDeclContext(DeclContext *DC);
672 
673   void setLexicalDeclContext(DeclContext *DC);
674 
675   /// isDefinedOutsideFunctionOrMethod - This predicate returns true if this
676   /// scoped decl is defined outside the current function or method.  This is
677   /// roughly global variables and functions, but also handles enums (which
678   /// could be defined inside or outside a function etc).
isDefinedOutsideFunctionOrMethod()679   bool isDefinedOutsideFunctionOrMethod() const {
680     return getParentFunctionOrMethod() == 0;
681   }
682 
683   /// \brief If this decl is defined inside a function/method/block it returns
684   /// the corresponding DeclContext, otherwise it returns null.
685   const DeclContext *getParentFunctionOrMethod() const;
getParentFunctionOrMethod()686   DeclContext *getParentFunctionOrMethod() {
687     return const_cast<DeclContext*>(
688                     const_cast<const Decl*>(this)->getParentFunctionOrMethod());
689   }
690 
691   /// \brief Retrieves the "canonical" declaration of the given declaration.
getCanonicalDecl()692   virtual Decl *getCanonicalDecl() { return this; }
getCanonicalDecl()693   const Decl *getCanonicalDecl() const {
694     return const_cast<Decl*>(this)->getCanonicalDecl();
695   }
696 
697   /// \brief Whether this particular Decl is a canonical one.
isCanonicalDecl()698   bool isCanonicalDecl() const { return getCanonicalDecl() == this; }
699 
700 protected:
701   /// \brief Returns the next redeclaration or itself if this is the only decl.
702   ///
703   /// Decl subclasses that can be redeclared should override this method so that
704   /// Decl::redecl_iterator can iterate over them.
getNextRedeclaration()705   virtual Decl *getNextRedeclaration() { return this; }
706 
707   /// \brief Implementation of getPreviousDecl(), to be overridden by any
708   /// subclass that has a redeclaration chain.
getPreviousDeclImpl()709   virtual Decl *getPreviousDeclImpl() { return 0; }
710 
711   /// \brief Implementation of getMostRecentDecl(), to be overridden by any
712   /// subclass that has a redeclaration chain.
getMostRecentDeclImpl()713   virtual Decl *getMostRecentDeclImpl() { return this; }
714 
715 public:
716   /// \brief Iterates through all the redeclarations of the same decl.
717   class redecl_iterator {
718     /// Current - The current declaration.
719     Decl *Current;
720     Decl *Starter;
721 
722   public:
723     typedef Decl *value_type;
724     typedef const value_type &reference;
725     typedef const value_type *pointer;
726     typedef std::forward_iterator_tag iterator_category;
727     typedef std::ptrdiff_t difference_type;
728 
redecl_iterator()729     redecl_iterator() : Current(0) { }
redecl_iterator(Decl * C)730     explicit redecl_iterator(Decl *C) : Current(C), Starter(C) { }
731 
732     reference operator*() const { return Current; }
733     value_type operator->() const { return Current; }
734 
735     redecl_iterator& operator++() {
736       assert(Current && "Advancing while iterator has reached end");
737       // Get either previous decl or latest decl.
738       Decl *Next = Current->getNextRedeclaration();
739       assert(Next && "Should return next redeclaration or itself, never null!");
740       Current = (Next != Starter ? Next : 0);
741       return *this;
742     }
743 
744     redecl_iterator operator++(int) {
745       redecl_iterator tmp(*this);
746       ++(*this);
747       return tmp;
748     }
749 
750     friend bool operator==(redecl_iterator x, redecl_iterator y) {
751       return x.Current == y.Current;
752     }
753     friend bool operator!=(redecl_iterator x, redecl_iterator y) {
754       return x.Current != y.Current;
755     }
756   };
757 
758   /// \brief Returns iterator for all the redeclarations of the same decl.
759   /// It will iterate at least once (when this decl is the only one).
redecls_begin()760   redecl_iterator redecls_begin() const {
761     return redecl_iterator(const_cast<Decl*>(this));
762   }
redecls_end()763   redecl_iterator redecls_end() const { return redecl_iterator(); }
764 
765   /// \brief Retrieve the previous declaration that declares the same entity
766   /// as this declaration, or NULL if there is no previous declaration.
getPreviousDecl()767   Decl *getPreviousDecl() { return getPreviousDeclImpl(); }
768 
769   /// \brief Retrieve the most recent declaration that declares the same entity
770   /// as this declaration, or NULL if there is no previous declaration.
getPreviousDecl()771   const Decl *getPreviousDecl() const {
772     return const_cast<Decl *>(this)->getPreviousDeclImpl();
773   }
774 
775   /// \brief Retrieve the most recent declaration that declares the same entity
776   /// as this declaration (which may be this declaration).
getMostRecentDecl()777   Decl *getMostRecentDecl() { return getMostRecentDeclImpl(); }
778 
779   /// \brief Retrieve the most recent declaration that declares the same entity
780   /// as this declaration (which may be this declaration).
getMostRecentDecl()781   const Decl *getMostRecentDecl() const {
782     return const_cast<Decl *>(this)->getMostRecentDeclImpl();
783   }
784 
785   /// getBody - If this Decl represents a declaration for a body of code,
786   ///  such as a function or method definition, this method returns the
787   ///  top-level Stmt* of that body.  Otherwise this method returns null.
getBody()788   virtual Stmt* getBody() const { return 0; }
789 
790   /// \brief Returns true if this \c Decl represents a declaration for a body of
791   /// code, such as a function or method definition.
792   /// Note that \c hasBody can also return true if any redeclaration of this
793   /// \c Decl represents a declaration for a body of code.
hasBody()794   virtual bool hasBody() const { return getBody() != 0; }
795 
796   /// getBodyRBrace - Gets the right brace of the body, if a body exists.
797   /// This works whether the body is a CompoundStmt or a CXXTryStmt.
798   SourceLocation getBodyRBrace() const;
799 
800   // global temp stats (until we have a per-module visitor)
801   static void add(Kind k);
802   static void EnableStatistics();
803   static void PrintStats();
804 
805   /// isTemplateParameter - Determines whether this declaration is a
806   /// template parameter.
807   bool isTemplateParameter() const;
808 
809   /// isTemplateParameter - Determines whether this declaration is a
810   /// template parameter pack.
811   bool isTemplateParameterPack() const;
812 
813   /// \brief Whether this declaration is a parameter pack.
814   bool isParameterPack() const;
815 
816   /// \brief returns true if this declaration is a template
817   bool isTemplateDecl() const;
818 
819   /// \brief Whether this declaration is a function or function template.
820   bool isFunctionOrFunctionTemplate() const;
821 
822   /// \brief Changes the namespace of this declaration to reflect that it's
823   /// the object of a friend declaration.
824   ///
825   /// These declarations appear in the lexical context of the friending
826   /// class, but in the semantic context of the actual entity.  This property
827   /// applies only to a specific decl object;  other redeclarations of the
828   /// same entity may not (and probably don't) share this property.
829   void setObjectOfFriendDecl(bool PerformFriendInjection = false) {
830     unsigned OldNS = IdentifierNamespace;
831     assert((OldNS & (IDNS_Tag | IDNS_Ordinary |
832                      IDNS_TagFriend | IDNS_OrdinaryFriend)) &&
833            "namespace includes neither ordinary nor tag");
834     assert(!(OldNS & ~(IDNS_Tag | IDNS_Ordinary | IDNS_Type |
835                        IDNS_TagFriend | IDNS_OrdinaryFriend)) &&
836            "namespace includes other than ordinary or tag");
837 
838     Decl *Prev = getPreviousDecl();
839     IdentifierNamespace = 0;
840     if (OldNS & (IDNS_Tag | IDNS_TagFriend)) {
841       IdentifierNamespace |= IDNS_TagFriend;
842       if (PerformFriendInjection ||
843           (Prev && Prev->getIdentifierNamespace() & IDNS_Tag))
844         IdentifierNamespace |= IDNS_Tag | IDNS_Type;
845     }
846 
847     if (OldNS & (IDNS_Ordinary | IDNS_OrdinaryFriend)) {
848       IdentifierNamespace |= IDNS_OrdinaryFriend;
849       if (PerformFriendInjection ||
850           (Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary))
851         IdentifierNamespace |= IDNS_Ordinary;
852     }
853   }
854 
855   enum FriendObjectKind {
856     FOK_None,      ///< Not a friend object.
857     FOK_Declared,  ///< A friend of a previously-declared entity.
858     FOK_Undeclared ///< A friend of a previously-undeclared entity.
859   };
860 
861   /// \brief Determines whether this declaration is the object of a
862   /// friend declaration and, if so, what kind.
863   ///
864   /// There is currently no direct way to find the associated FriendDecl.
getFriendObjectKind()865   FriendObjectKind getFriendObjectKind() const {
866     unsigned mask =
867         (IdentifierNamespace & (IDNS_TagFriend | IDNS_OrdinaryFriend));
868     if (!mask) return FOK_None;
869     return (IdentifierNamespace & (IDNS_Tag | IDNS_Ordinary) ? FOK_Declared
870                                                              : FOK_Undeclared);
871   }
872 
873   /// Specifies that this declaration is a C++ overloaded non-member.
setNonMemberOperator()874   void setNonMemberOperator() {
875     assert(getKind() == Function || getKind() == FunctionTemplate);
876     assert((IdentifierNamespace & IDNS_Ordinary) &&
877            "visible non-member operators should be in ordinary namespace");
878     IdentifierNamespace |= IDNS_NonMemberOperator;
879   }
880 
classofKind(Kind K)881   static bool classofKind(Kind K) { return true; }
882   static DeclContext *castToDeclContext(const Decl *);
883   static Decl *castFromDeclContext(const DeclContext *);
884 
885   void print(raw_ostream &Out, unsigned Indentation = 0,
886              bool PrintInstantiation = false) const;
887   void print(raw_ostream &Out, const PrintingPolicy &Policy,
888              unsigned Indentation = 0, bool PrintInstantiation = false) const;
889   static void printGroup(Decl** Begin, unsigned NumDecls,
890                          raw_ostream &Out, const PrintingPolicy &Policy,
891                          unsigned Indentation = 0);
892   // Debuggers don't usually respect default arguments.
893   LLVM_ATTRIBUTE_USED void dump() const;
894   // Same as dump(), but forces color printing.
895   LLVM_ATTRIBUTE_USED void dumpColor() const;
896   void dump(raw_ostream &Out) const;
897   // Debuggers don't usually respect default arguments.
898   LLVM_ATTRIBUTE_USED void dumpXML() const;
899   void dumpXML(raw_ostream &OS) const;
900 
901 private:
902   void setAttrsImpl(const AttrVec& Attrs, ASTContext &Ctx);
903   void setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
904                            ASTContext &Ctx);
905 
906 protected:
907   ASTMutationListener *getASTMutationListener() const;
908 };
909 
910 /// \brief Determine whether two declarations declare the same entity.
declaresSameEntity(const Decl * D1,const Decl * D2)911 inline bool declaresSameEntity(const Decl *D1, const Decl *D2) {
912   if (!D1 || !D2)
913     return false;
914 
915   if (D1 == D2)
916     return true;
917 
918   return D1->getCanonicalDecl() == D2->getCanonicalDecl();
919 }
920 
921 /// PrettyStackTraceDecl - If a crash occurs, indicate that it happened when
922 /// doing something to a specific decl.
923 class PrettyStackTraceDecl : public llvm::PrettyStackTraceEntry {
924   const Decl *TheDecl;
925   SourceLocation Loc;
926   SourceManager &SM;
927   const char *Message;
928 public:
PrettyStackTraceDecl(const Decl * theDecl,SourceLocation L,SourceManager & sm,const char * Msg)929   PrettyStackTraceDecl(const Decl *theDecl, SourceLocation L,
930                        SourceManager &sm, const char *Msg)
931   : TheDecl(theDecl), Loc(L), SM(sm), Message(Msg) {}
932 
933   virtual void print(raw_ostream &OS) const;
934 };
935 
936 typedef llvm::MutableArrayRef<NamedDecl*> DeclContextLookupResult;
937 
938 typedef ArrayRef<NamedDecl *> DeclContextLookupConstResult;
939 
940 /// DeclContext - This is used only as base class of specific decl types that
941 /// can act as declaration contexts. These decls are (only the top classes
942 /// that directly derive from DeclContext are mentioned, not their subclasses):
943 ///
944 ///   TranslationUnitDecl
945 ///   NamespaceDecl
946 ///   FunctionDecl
947 ///   TagDecl
948 ///   ObjCMethodDecl
949 ///   ObjCContainerDecl
950 ///   LinkageSpecDecl
951 ///   BlockDecl
952 ///
953 class DeclContext {
954   /// DeclKind - This indicates which class this is.
955   unsigned DeclKind : 8;
956 
957   /// \brief Whether this declaration context also has some external
958   /// storage that contains additional declarations that are lexically
959   /// part of this context.
960   mutable bool ExternalLexicalStorage : 1;
961 
962   /// \brief Whether this declaration context also has some external
963   /// storage that contains additional declarations that are visible
964   /// in this context.
965   mutable bool ExternalVisibleStorage : 1;
966 
967   /// \brief Whether this declaration context has had external visible
968   /// storage added since the last lookup. In this case, \c LookupPtr's
969   /// invariant may not hold and needs to be fixed before we perform
970   /// another lookup.
971   mutable bool NeedToReconcileExternalVisibleStorage : 1;
972 
973   /// \brief Pointer to the data structure used to lookup declarations
974   /// within this context (or a DependentStoredDeclsMap if this is a
975   /// dependent context), and a bool indicating whether we have lazily
976   /// omitted any declarations from the map. We maintain the invariant
977   /// that, if the map contains an entry for a DeclarationName (and we
978   /// haven't lazily omitted anything), then it contains all relevant
979   /// entries for that name.
980   mutable llvm::PointerIntPair<StoredDeclsMap*, 1, bool> LookupPtr;
981 
982 protected:
983   /// FirstDecl - The first declaration stored within this declaration
984   /// context.
985   mutable Decl *FirstDecl;
986 
987   /// LastDecl - The last declaration stored within this declaration
988   /// context. FIXME: We could probably cache this value somewhere
989   /// outside of the DeclContext, to reduce the size of DeclContext by
990   /// another pointer.
991   mutable Decl *LastDecl;
992 
993   friend class ExternalASTSource;
994   friend class ASTDeclReader;
995   friend class ASTWriter;
996 
997   /// \brief Build up a chain of declarations.
998   ///
999   /// \returns the first/last pair of declarations.
1000   static std::pair<Decl *, Decl *>
1001   BuildDeclChain(ArrayRef<Decl*> Decls, bool FieldsAlreadyLoaded);
1002 
DeclContext(Decl::Kind K)1003   DeclContext(Decl::Kind K)
1004       : DeclKind(K), ExternalLexicalStorage(false),
1005         ExternalVisibleStorage(false),
1006         NeedToReconcileExternalVisibleStorage(false), LookupPtr(0, false),
1007         FirstDecl(0), LastDecl(0) {}
1008 
1009 public:
1010   ~DeclContext();
1011 
getDeclKind()1012   Decl::Kind getDeclKind() const {
1013     return static_cast<Decl::Kind>(DeclKind);
1014   }
1015   const char *getDeclKindName() const;
1016 
1017   /// getParent - Returns the containing DeclContext.
getParent()1018   DeclContext *getParent() {
1019     return cast<Decl>(this)->getDeclContext();
1020   }
getParent()1021   const DeclContext *getParent() const {
1022     return const_cast<DeclContext*>(this)->getParent();
1023   }
1024 
1025   /// getLexicalParent - Returns the containing lexical DeclContext. May be
1026   /// different from getParent, e.g.:
1027   ///
1028   ///   namespace A {
1029   ///      struct S;
1030   ///   }
1031   ///   struct A::S {}; // getParent() == namespace 'A'
1032   ///                   // getLexicalParent() == translation unit
1033   ///
getLexicalParent()1034   DeclContext *getLexicalParent() {
1035     return cast<Decl>(this)->getLexicalDeclContext();
1036   }
getLexicalParent()1037   const DeclContext *getLexicalParent() const {
1038     return const_cast<DeclContext*>(this)->getLexicalParent();
1039   }
1040 
1041   DeclContext *getLookupParent();
1042 
getLookupParent()1043   const DeclContext *getLookupParent() const {
1044     return const_cast<DeclContext*>(this)->getLookupParent();
1045   }
1046 
getParentASTContext()1047   ASTContext &getParentASTContext() const {
1048     return cast<Decl>(this)->getASTContext();
1049   }
1050 
isClosure()1051   bool isClosure() const {
1052     return DeclKind == Decl::Block;
1053   }
1054 
isObjCContainer()1055   bool isObjCContainer() const {
1056     switch (DeclKind) {
1057         case Decl::ObjCCategory:
1058         case Decl::ObjCCategoryImpl:
1059         case Decl::ObjCImplementation:
1060         case Decl::ObjCInterface:
1061         case Decl::ObjCProtocol:
1062             return true;
1063     }
1064     return false;
1065   }
1066 
isFunctionOrMethod()1067   bool isFunctionOrMethod() const {
1068     switch (DeclKind) {
1069     case Decl::Block:
1070     case Decl::Captured:
1071     case Decl::ObjCMethod:
1072       return true;
1073     default:
1074       return DeclKind >= Decl::firstFunction && DeclKind <= Decl::lastFunction;
1075     }
1076   }
1077 
isFileContext()1078   bool isFileContext() const {
1079     return DeclKind == Decl::TranslationUnit || DeclKind == Decl::Namespace;
1080   }
1081 
isTranslationUnit()1082   bool isTranslationUnit() const {
1083     return DeclKind == Decl::TranslationUnit;
1084   }
1085 
isRecord()1086   bool isRecord() const {
1087     return DeclKind >= Decl::firstRecord && DeclKind <= Decl::lastRecord;
1088   }
1089 
isNamespace()1090   bool isNamespace() const {
1091     return DeclKind == Decl::Namespace;
1092   }
1093 
1094   bool isInlineNamespace() const;
1095 
1096   /// \brief Determines whether this context is dependent on a
1097   /// template parameter.
1098   bool isDependentContext() const;
1099 
1100   /// isTransparentContext - Determines whether this context is a
1101   /// "transparent" context, meaning that the members declared in this
1102   /// context are semantically declared in the nearest enclosing
1103   /// non-transparent (opaque) context but are lexically declared in
1104   /// this context. For example, consider the enumerators of an
1105   /// enumeration type:
1106   /// @code
1107   /// enum E {
1108   ///   Val1
1109   /// };
1110   /// @endcode
1111   /// Here, E is a transparent context, so its enumerator (Val1) will
1112   /// appear (semantically) that it is in the same context of E.
1113   /// Examples of transparent contexts include: enumerations (except for
1114   /// C++0x scoped enums), and C++ linkage specifications.
1115   bool isTransparentContext() const;
1116 
1117   /// \brief Determine whether this declaration context is equivalent
1118   /// to the declaration context DC.
Equals(const DeclContext * DC)1119   bool Equals(const DeclContext *DC) const {
1120     return DC && this->getPrimaryContext() == DC->getPrimaryContext();
1121   }
1122 
1123   /// \brief Determine whether this declaration context encloses the
1124   /// declaration context DC.
1125   bool Encloses(const DeclContext *DC) const;
1126 
1127   /// \brief Find the nearest non-closure ancestor of this context,
1128   /// i.e. the innermost semantic parent of this context which is not
1129   /// a closure.  A context may be its own non-closure ancestor.
1130   Decl *getNonClosureAncestor();
getNonClosureAncestor()1131   const Decl *getNonClosureAncestor() const {
1132     return const_cast<DeclContext*>(this)->getNonClosureAncestor();
1133   }
1134 
1135   /// getPrimaryContext - There may be many different
1136   /// declarations of the same entity (including forward declarations
1137   /// of classes, multiple definitions of namespaces, etc.), each with
1138   /// a different set of declarations. This routine returns the
1139   /// "primary" DeclContext structure, which will contain the
1140   /// information needed to perform name lookup into this context.
1141   DeclContext *getPrimaryContext();
getPrimaryContext()1142   const DeclContext *getPrimaryContext() const {
1143     return const_cast<DeclContext*>(this)->getPrimaryContext();
1144   }
1145 
1146   /// getRedeclContext - Retrieve the context in which an entity conflicts with
1147   /// other entities of the same name, or where it is a redeclaration if the
1148   /// two entities are compatible. This skips through transparent contexts.
1149   DeclContext *getRedeclContext();
getRedeclContext()1150   const DeclContext *getRedeclContext() const {
1151     return const_cast<DeclContext *>(this)->getRedeclContext();
1152   }
1153 
1154   /// \brief Retrieve the nearest enclosing namespace context.
1155   DeclContext *getEnclosingNamespaceContext();
getEnclosingNamespaceContext()1156   const DeclContext *getEnclosingNamespaceContext() const {
1157     return const_cast<DeclContext *>(this)->getEnclosingNamespaceContext();
1158   }
1159 
1160   /// \brief Test if this context is part of the enclosing namespace set of
1161   /// the context NS, as defined in C++0x [namespace.def]p9. If either context
1162   /// isn't a namespace, this is equivalent to Equals().
1163   ///
1164   /// The enclosing namespace set of a namespace is the namespace and, if it is
1165   /// inline, its enclosing namespace, recursively.
1166   bool InEnclosingNamespaceSetOf(const DeclContext *NS) const;
1167 
1168   /// \brief Collects all of the declaration contexts that are semantically
1169   /// connected to this declaration context.
1170   ///
1171   /// For declaration contexts that have multiple semantically connected but
1172   /// syntactically distinct contexts, such as C++ namespaces, this routine
1173   /// retrieves the complete set of such declaration contexts in source order.
1174   /// For example, given:
1175   ///
1176   /// \code
1177   /// namespace N {
1178   ///   int x;
1179   /// }
1180   /// namespace N {
1181   ///   int y;
1182   /// }
1183   /// \endcode
1184   ///
1185   /// The \c Contexts parameter will contain both definitions of N.
1186   ///
1187   /// \param Contexts Will be cleared and set to the set of declaration
1188   /// contexts that are semanticaly connected to this declaration context,
1189   /// in source order, including this context (which may be the only result,
1190   /// for non-namespace contexts).
1191   void collectAllContexts(SmallVectorImpl<DeclContext *> &Contexts);
1192 
1193   /// decl_iterator - Iterates through the declarations stored
1194   /// within this context.
1195   class decl_iterator {
1196     /// Current - The current declaration.
1197     Decl *Current;
1198 
1199   public:
1200     typedef Decl *value_type;
1201     typedef const value_type &reference;
1202     typedef const value_type *pointer;
1203     typedef std::forward_iterator_tag iterator_category;
1204     typedef std::ptrdiff_t            difference_type;
1205 
decl_iterator()1206     decl_iterator() : Current(0) { }
decl_iterator(Decl * C)1207     explicit decl_iterator(Decl *C) : Current(C) { }
1208 
1209     reference operator*() const { return Current; }
1210     // This doesn't meet the iterator requirements, but it's convenient
1211     value_type operator->() const { return Current; }
1212 
1213     decl_iterator& operator++() {
1214       Current = Current->getNextDeclInContext();
1215       return *this;
1216     }
1217 
1218     decl_iterator operator++(int) {
1219       decl_iterator tmp(*this);
1220       ++(*this);
1221       return tmp;
1222     }
1223 
1224     friend bool operator==(decl_iterator x, decl_iterator y) {
1225       return x.Current == y.Current;
1226     }
1227     friend bool operator!=(decl_iterator x, decl_iterator y) {
1228       return x.Current != y.Current;
1229     }
1230   };
1231 
1232   /// decls_begin/decls_end - Iterate over the declarations stored in
1233   /// this context.
1234   decl_iterator decls_begin() const;
decls_end()1235   decl_iterator decls_end() const { return decl_iterator(); }
1236   bool decls_empty() const;
1237 
1238   /// noload_decls_begin/end - Iterate over the declarations stored in this
1239   /// context that are currently loaded; don't attempt to retrieve anything
1240   /// from an external source.
1241   decl_iterator noload_decls_begin() const;
noload_decls_end()1242   decl_iterator noload_decls_end() const { return decl_iterator(); }
1243 
1244   /// specific_decl_iterator - Iterates over a subrange of
1245   /// declarations stored in a DeclContext, providing only those that
1246   /// are of type SpecificDecl (or a class derived from it). This
1247   /// iterator is used, for example, to provide iteration over just
1248   /// the fields within a RecordDecl (with SpecificDecl = FieldDecl).
1249   template<typename SpecificDecl>
1250   class specific_decl_iterator {
1251     /// Current - The current, underlying declaration iterator, which
1252     /// will either be NULL or will point to a declaration of
1253     /// type SpecificDecl.
1254     DeclContext::decl_iterator Current;
1255 
1256     /// SkipToNextDecl - Advances the current position up to the next
1257     /// declaration of type SpecificDecl that also meets the criteria
1258     /// required by Acceptable.
SkipToNextDecl()1259     void SkipToNextDecl() {
1260       while (*Current && !isa<SpecificDecl>(*Current))
1261         ++Current;
1262     }
1263 
1264   public:
1265     typedef SpecificDecl *value_type;
1266     // TODO: Add reference and pointer typedefs (with some appropriate proxy
1267     // type) if we ever have a need for them.
1268     typedef void reference;
1269     typedef void pointer;
1270     typedef std::iterator_traits<DeclContext::decl_iterator>::difference_type
1271       difference_type;
1272     typedef std::forward_iterator_tag iterator_category;
1273 
specific_decl_iterator()1274     specific_decl_iterator() : Current() { }
1275 
1276     /// specific_decl_iterator - Construct a new iterator over a
1277     /// subset of the declarations the range [C,
1278     /// end-of-declarations). If A is non-NULL, it is a pointer to a
1279     /// member function of SpecificDecl that should return true for
1280     /// all of the SpecificDecl instances that will be in the subset
1281     /// of iterators. For example, if you want Objective-C instance
1282     /// methods, SpecificDecl will be ObjCMethodDecl and A will be
1283     /// &ObjCMethodDecl::isInstanceMethod.
specific_decl_iterator(DeclContext::decl_iterator C)1284     explicit specific_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
1285       SkipToNextDecl();
1286     }
1287 
1288     value_type operator*() const { return cast<SpecificDecl>(*Current); }
1289     // This doesn't meet the iterator requirements, but it's convenient
1290     value_type operator->() const { return **this; }
1291 
1292     specific_decl_iterator& operator++() {
1293       ++Current;
1294       SkipToNextDecl();
1295       return *this;
1296     }
1297 
1298     specific_decl_iterator operator++(int) {
1299       specific_decl_iterator tmp(*this);
1300       ++(*this);
1301       return tmp;
1302     }
1303 
1304     friend bool operator==(const specific_decl_iterator& x,
1305                            const specific_decl_iterator& y) {
1306       return x.Current == y.Current;
1307     }
1308 
1309     friend bool operator!=(const specific_decl_iterator& x,
1310                            const specific_decl_iterator& y) {
1311       return x.Current != y.Current;
1312     }
1313   };
1314 
1315   /// \brief Iterates over a filtered subrange of declarations stored
1316   /// in a DeclContext.
1317   ///
1318   /// This iterator visits only those declarations that are of type
1319   /// SpecificDecl (or a class derived from it) and that meet some
1320   /// additional run-time criteria. This iterator is used, for
1321   /// example, to provide access to the instance methods within an
1322   /// Objective-C interface (with SpecificDecl = ObjCMethodDecl and
1323   /// Acceptable = ObjCMethodDecl::isInstanceMethod).
1324   template<typename SpecificDecl, bool (SpecificDecl::*Acceptable)() const>
1325   class filtered_decl_iterator {
1326     /// Current - The current, underlying declaration iterator, which
1327     /// will either be NULL or will point to a declaration of
1328     /// type SpecificDecl.
1329     DeclContext::decl_iterator Current;
1330 
1331     /// SkipToNextDecl - Advances the current position up to the next
1332     /// declaration of type SpecificDecl that also meets the criteria
1333     /// required by Acceptable.
SkipToNextDecl()1334     void SkipToNextDecl() {
1335       while (*Current &&
1336              (!isa<SpecificDecl>(*Current) ||
1337               (Acceptable && !(cast<SpecificDecl>(*Current)->*Acceptable)())))
1338         ++Current;
1339     }
1340 
1341   public:
1342     typedef SpecificDecl *value_type;
1343     // TODO: Add reference and pointer typedefs (with some appropriate proxy
1344     // type) if we ever have a need for them.
1345     typedef void reference;
1346     typedef void pointer;
1347     typedef std::iterator_traits<DeclContext::decl_iterator>::difference_type
1348       difference_type;
1349     typedef std::forward_iterator_tag iterator_category;
1350 
filtered_decl_iterator()1351     filtered_decl_iterator() : Current() { }
1352 
1353     /// filtered_decl_iterator - Construct a new iterator over a
1354     /// subset of the declarations the range [C,
1355     /// end-of-declarations). If A is non-NULL, it is a pointer to a
1356     /// member function of SpecificDecl that should return true for
1357     /// all of the SpecificDecl instances that will be in the subset
1358     /// of iterators. For example, if you want Objective-C instance
1359     /// methods, SpecificDecl will be ObjCMethodDecl and A will be
1360     /// &ObjCMethodDecl::isInstanceMethod.
filtered_decl_iterator(DeclContext::decl_iterator C)1361     explicit filtered_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
1362       SkipToNextDecl();
1363     }
1364 
1365     value_type operator*() const { return cast<SpecificDecl>(*Current); }
1366     value_type operator->() const { return cast<SpecificDecl>(*Current); }
1367 
1368     filtered_decl_iterator& operator++() {
1369       ++Current;
1370       SkipToNextDecl();
1371       return *this;
1372     }
1373 
1374     filtered_decl_iterator operator++(int) {
1375       filtered_decl_iterator tmp(*this);
1376       ++(*this);
1377       return tmp;
1378     }
1379 
1380     friend bool operator==(const filtered_decl_iterator& x,
1381                            const filtered_decl_iterator& y) {
1382       return x.Current == y.Current;
1383     }
1384 
1385     friend bool operator!=(const filtered_decl_iterator& x,
1386                            const filtered_decl_iterator& y) {
1387       return x.Current != y.Current;
1388     }
1389   };
1390 
1391   /// @brief Add the declaration D into this context.
1392   ///
1393   /// This routine should be invoked when the declaration D has first
1394   /// been declared, to place D into the context where it was
1395   /// (lexically) defined. Every declaration must be added to one
1396   /// (and only one!) context, where it can be visited via
1397   /// [decls_begin(), decls_end()). Once a declaration has been added
1398   /// to its lexical context, the corresponding DeclContext owns the
1399   /// declaration.
1400   ///
1401   /// If D is also a NamedDecl, it will be made visible within its
1402   /// semantic context via makeDeclVisibleInContext.
1403   void addDecl(Decl *D);
1404 
1405   /// @brief Add the declaration D into this context, but suppress
1406   /// searches for external declarations with the same name.
1407   ///
1408   /// Although analogous in function to addDecl, this removes an
1409   /// important check.  This is only useful if the Decl is being
1410   /// added in response to an external search; in all other cases,
1411   /// addDecl() is the right function to use.
1412   /// See the ASTImporter for use cases.
1413   void addDeclInternal(Decl *D);
1414 
1415   /// @brief Add the declaration D to this context without modifying
1416   /// any lookup tables.
1417   ///
1418   /// This is useful for some operations in dependent contexts where
1419   /// the semantic context might not be dependent;  this basically
1420   /// only happens with friends.
1421   void addHiddenDecl(Decl *D);
1422 
1423   /// @brief Removes a declaration from this context.
1424   void removeDecl(Decl *D);
1425 
1426   /// @brief Checks whether a declaration is in this context.
1427   bool containsDecl(Decl *D) const;
1428 
1429   /// lookup_iterator - An iterator that provides access to the results
1430   /// of looking up a name within this context.
1431   typedef NamedDecl **lookup_iterator;
1432 
1433   /// lookup_const_iterator - An iterator that provides non-mutable
1434   /// access to the results of lookup up a name within this context.
1435   typedef NamedDecl * const * lookup_const_iterator;
1436 
1437   typedef DeclContextLookupResult lookup_result;
1438   typedef DeclContextLookupConstResult lookup_const_result;
1439 
1440   /// lookup - Find the declarations (if any) with the given Name in
1441   /// this context. Returns a range of iterators that contains all of
1442   /// the declarations with this name, with object, function, member,
1443   /// and enumerator names preceding any tag name. Note that this
1444   /// routine will not look into parent contexts.
1445   lookup_result lookup(DeclarationName Name);
lookup(DeclarationName Name)1446   lookup_const_result lookup(DeclarationName Name) const {
1447     return const_cast<DeclContext*>(this)->lookup(Name);
1448   }
1449 
1450   /// \brief Find the declarations with the given name that are visible
1451   /// within this context; don't attempt to retrieve anything from an
1452   /// external source.
1453   lookup_result noload_lookup(DeclarationName Name);
1454 
1455   /// \brief A simplistic name lookup mechanism that performs name lookup
1456   /// into this declaration context without consulting the external source.
1457   ///
1458   /// This function should almost never be used, because it subverts the
1459   /// usual relationship between a DeclContext and the external source.
1460   /// See the ASTImporter for the (few, but important) use cases.
1461   ///
1462   /// FIXME: This is very inefficient; replace uses of it with uses of
1463   /// noload_lookup.
1464   void localUncachedLookup(DeclarationName Name,
1465                            SmallVectorImpl<NamedDecl *> &Results);
1466 
1467   /// @brief Makes a declaration visible within this context.
1468   ///
1469   /// This routine makes the declaration D visible to name lookup
1470   /// within this context and, if this is a transparent context,
1471   /// within its parent contexts up to the first enclosing
1472   /// non-transparent context. Making a declaration visible within a
1473   /// context does not transfer ownership of a declaration, and a
1474   /// declaration can be visible in many contexts that aren't its
1475   /// lexical context.
1476   ///
1477   /// If D is a redeclaration of an existing declaration that is
1478   /// visible from this context, as determined by
1479   /// NamedDecl::declarationReplaces, the previous declaration will be
1480   /// replaced with D.
1481   void makeDeclVisibleInContext(NamedDecl *D);
1482 
1483   /// all_lookups_iterator - An iterator that provides a view over the results
1484   /// of looking up every possible name.
1485   class all_lookups_iterator;
1486 
1487   /// \brief Iterators over all possible lookups within this context.
1488   all_lookups_iterator lookups_begin() const;
1489   all_lookups_iterator lookups_end() const;
1490 
1491   /// \brief Iterators over all possible lookups within this context that are
1492   /// currently loaded; don't attempt to retrieve anything from an external
1493   /// source.
1494   all_lookups_iterator noload_lookups_begin() const;
1495   all_lookups_iterator noload_lookups_end() const;
1496 
1497   /// udir_iterator - Iterates through the using-directives stored
1498   /// within this context.
1499   typedef UsingDirectiveDecl * const * udir_iterator;
1500 
1501   typedef std::pair<udir_iterator, udir_iterator> udir_iterator_range;
1502 
1503   udir_iterator_range getUsingDirectives() const;
1504 
using_directives_begin()1505   udir_iterator using_directives_begin() const {
1506     return getUsingDirectives().first;
1507   }
1508 
using_directives_end()1509   udir_iterator using_directives_end() const {
1510     return getUsingDirectives().second;
1511   }
1512 
1513   // These are all defined in DependentDiagnostic.h.
1514   class ddiag_iterator;
1515   inline ddiag_iterator ddiag_begin() const;
1516   inline ddiag_iterator ddiag_end() const;
1517 
1518   // Low-level accessors
1519 
1520   /// \brief Mark the lookup table as needing to be built.  This should be
1521   /// used only if setHasExternalLexicalStorage() has been called on any
1522   /// decl context for which this is the primary context.
setMustBuildLookupTable()1523   void setMustBuildLookupTable() {
1524     LookupPtr.setInt(true);
1525   }
1526 
1527   /// \brief Retrieve the internal representation of the lookup structure.
1528   /// This may omit some names if we are lazily building the structure.
getLookupPtr()1529   StoredDeclsMap *getLookupPtr() const { return LookupPtr.getPointer(); }
1530 
1531   /// \brief Ensure the lookup structure is fully-built and return it.
1532   StoredDeclsMap *buildLookup();
1533 
1534   /// \brief Whether this DeclContext has external storage containing
1535   /// additional declarations that are lexically in this context.
hasExternalLexicalStorage()1536   bool hasExternalLexicalStorage() const { return ExternalLexicalStorage; }
1537 
1538   /// \brief State whether this DeclContext has external storage for
1539   /// declarations lexically in this context.
1540   void setHasExternalLexicalStorage(bool ES = true) {
1541     ExternalLexicalStorage = ES;
1542   }
1543 
1544   /// \brief Whether this DeclContext has external storage containing
1545   /// additional declarations that are visible in this context.
hasExternalVisibleStorage()1546   bool hasExternalVisibleStorage() const { return ExternalVisibleStorage; }
1547 
1548   /// \brief State whether this DeclContext has external storage for
1549   /// declarations visible in this context.
1550   void setHasExternalVisibleStorage(bool ES = true) {
1551     ExternalVisibleStorage = ES;
1552     if (ES && LookupPtr.getPointer())
1553       NeedToReconcileExternalVisibleStorage = true;
1554   }
1555 
1556   /// \brief Determine whether the given declaration is stored in the list of
1557   /// declarations lexically within this context.
isDeclInLexicalTraversal(const Decl * D)1558   bool isDeclInLexicalTraversal(const Decl *D) const {
1559     return D && (D->NextInContextAndBits.getPointer() || D == FirstDecl ||
1560                  D == LastDecl);
1561   }
1562 
1563   static bool classof(const Decl *D);
classof(const DeclContext * D)1564   static bool classof(const DeclContext *D) { return true; }
1565 
1566   LLVM_ATTRIBUTE_USED void dumpDeclContext() const;
1567   LLVM_ATTRIBUTE_USED void dumpLookups() const;
1568   LLVM_ATTRIBUTE_USED void dumpLookups(llvm::raw_ostream &OS) const;
1569 
1570 private:
1571   void reconcileExternalVisibleStorage();
1572   void LoadLexicalDeclsFromExternalStorage() const;
1573 
1574   /// @brief Makes a declaration visible within this context, but
1575   /// suppresses searches for external declarations with the same
1576   /// name.
1577   ///
1578   /// Analogous to makeDeclVisibleInContext, but for the exclusive
1579   /// use of addDeclInternal().
1580   void makeDeclVisibleInContextInternal(NamedDecl *D);
1581 
1582   friend class DependentDiagnostic;
1583   StoredDeclsMap *CreateStoredDeclsMap(ASTContext &C) const;
1584 
1585   template<decl_iterator (DeclContext::*Begin)() const,
1586            decl_iterator (DeclContext::*End)() const>
1587   void buildLookupImpl(DeclContext *DCtx);
1588   void makeDeclVisibleInContextWithFlags(NamedDecl *D, bool Internal,
1589                                          bool Rediscoverable);
1590   void makeDeclVisibleInContextImpl(NamedDecl *D, bool Internal);
1591 };
1592 
isTemplateParameter()1593 inline bool Decl::isTemplateParameter() const {
1594   return getKind() == TemplateTypeParm || getKind() == NonTypeTemplateParm ||
1595          getKind() == TemplateTemplateParm;
1596 }
1597 
1598 // Specialization selected when ToTy is not a known subclass of DeclContext.
1599 template <class ToTy,
1600           bool IsKnownSubtype = ::llvm::is_base_of< DeclContext, ToTy>::value>
1601 struct cast_convert_decl_context {
doitcast_convert_decl_context1602   static const ToTy *doit(const DeclContext *Val) {
1603     return static_cast<const ToTy*>(Decl::castFromDeclContext(Val));
1604   }
1605 
doitcast_convert_decl_context1606   static ToTy *doit(DeclContext *Val) {
1607     return static_cast<ToTy*>(Decl::castFromDeclContext(Val));
1608   }
1609 };
1610 
1611 // Specialization selected when ToTy is a known subclass of DeclContext.
1612 template <class ToTy>
1613 struct cast_convert_decl_context<ToTy, true> {
1614   static const ToTy *doit(const DeclContext *Val) {
1615     return static_cast<const ToTy*>(Val);
1616   }
1617 
1618   static ToTy *doit(DeclContext *Val) {
1619     return static_cast<ToTy*>(Val);
1620   }
1621 };
1622 
1623 
1624 } // end clang.
1625 
1626 namespace llvm {
1627 
1628 /// isa<T>(DeclContext*)
1629 template <typename To>
1630 struct isa_impl<To, ::clang::DeclContext> {
1631   static bool doit(const ::clang::DeclContext &Val) {
1632     return To::classofKind(Val.getDeclKind());
1633   }
1634 };
1635 
1636 /// cast<T>(DeclContext*)
1637 template<class ToTy>
1638 struct cast_convert_val<ToTy,
1639                         const ::clang::DeclContext,const ::clang::DeclContext> {
1640   static const ToTy &doit(const ::clang::DeclContext &Val) {
1641     return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
1642   }
1643 };
1644 template<class ToTy>
1645 struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext> {
1646   static ToTy &doit(::clang::DeclContext &Val) {
1647     return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
1648   }
1649 };
1650 template<class ToTy>
1651 struct cast_convert_val<ToTy,
1652                      const ::clang::DeclContext*, const ::clang::DeclContext*> {
1653   static const ToTy *doit(const ::clang::DeclContext *Val) {
1654     return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
1655   }
1656 };
1657 template<class ToTy>
1658 struct cast_convert_val<ToTy, ::clang::DeclContext*, ::clang::DeclContext*> {
1659   static ToTy *doit(::clang::DeclContext *Val) {
1660     return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
1661   }
1662 };
1663 
1664 /// Implement cast_convert_val for Decl -> DeclContext conversions.
1665 template<class FromTy>
1666 struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
1667   static ::clang::DeclContext &doit(const FromTy &Val) {
1668     return *FromTy::castToDeclContext(&Val);
1669   }
1670 };
1671 
1672 template<class FromTy>
1673 struct cast_convert_val< ::clang::DeclContext, FromTy*, FromTy*> {
1674   static ::clang::DeclContext *doit(const FromTy *Val) {
1675     return FromTy::castToDeclContext(Val);
1676   }
1677 };
1678 
1679 template<class FromTy>
1680 struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
1681   static const ::clang::DeclContext &doit(const FromTy &Val) {
1682     return *FromTy::castToDeclContext(&Val);
1683   }
1684 };
1685 
1686 template<class FromTy>
1687 struct cast_convert_val< const ::clang::DeclContext, FromTy*, FromTy*> {
1688   static const ::clang::DeclContext *doit(const FromTy *Val) {
1689     return FromTy::castToDeclContext(Val);
1690   }
1691 };
1692 
1693 } // end namespace llvm
1694 
1695 #endif
1696