Import Clang, at r72732.

1 files changed, 900 insertions, 0 deletions

diff --git a/include/clang/AST/DeclBase.h b/include/clang/AST/DeclBase.h
new file mode 100644
index 0000000..c061b85
--- /dev/null
+++ b/include/clang/AST/DeclBase.h
@@ -0,0 +1,900 @@
+//===-- DeclBase.h - Base Classes for representing declarations -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the Decl and DeclContext interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_DECLBASE_H
+#define LLVM_CLANG_AST_DECLBASE_H
+
+#include "clang/AST/Attr.h"
+#include "clang/AST/Type.h"
+// FIXME: Layering violation
+#include "clang/Parse/AccessSpecifier.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/ADT/PointerUnion.h"
+
+namespace clang {
+class DeclContext;
+class TranslationUnitDecl;
+class NamespaceDecl;
+class UsingDirectiveDecl;
+class NamedDecl;
+class FunctionDecl;
+class CXXRecordDecl;
+class EnumDecl;
+class ObjCMethodDecl;
+class ObjCContainerDecl;
+class ObjCInterfaceDecl;
+class ObjCCategoryDecl;
+class ObjCProtocolDecl;
+class ObjCImplementationDecl;
+class ObjCCategoryImplDecl;
+class LinkageSpecDecl;
+class BlockDecl;
+class DeclarationName;
+class CompoundStmt;
+}
+
+namespace llvm {
+// DeclContext* is only 4-byte aligned on 32-bit systems.
+template<>
+  class PointerLikeTypeTraits<clang::DeclContext*> {
+  typedef clang::DeclContext* PT;
+public:
+  static inline void *getAsVoidPointer(PT P) { return P; }
+  static inline PT getFromVoidPointer(void *P) {
+    return static_cast<PT>(P);
+  }
+  enum { NumLowBitsAvailable = 2 };
+};
+}
+
+namespace clang {
+
+/// Decl - This represents one declaration (or definition), e.g. a variable, 
+/// typedef, function, struct, etc.  
+///
+class Decl {
+public:
+  /// \brief Lists the kind of concrete classes of Decl.
+  enum Kind {
+#define DECL(Derived, Base) Derived,
+#define DECL_RANGE(CommonBase, Start, End) \
+    CommonBase##First = Start, CommonBase##Last = End, 
+#define LAST_DECL_RANGE(CommonBase, Start, End) \
+    CommonBase##First = Start, CommonBase##Last = End
+#include "clang/AST/DeclNodes.def"
+  };
+
+  /// IdentifierNamespace - According to C99 6.2.3, there are four
+  /// namespaces, labels, tags, members and ordinary
+  /// identifiers. These are meant as bitmasks, so that searches in
+  /// C++ can look into the "tag" namespace during ordinary lookup. We
+  /// use additional namespaces for Objective-C entities.
+  enum IdentifierNamespace {
+    IDNS_Label = 0x1,
+    IDNS_Tag = 0x2,
+    IDNS_Member = 0x4,
+    IDNS_Ordinary = 0x8,
+    IDNS_ObjCProtocol = 0x10,
+    IDNS_ObjCImplementation = 0x20,
+    IDNS_ObjCCategoryImpl = 0x40
+  };
+  
+  /// ObjCDeclQualifier - Qualifier used on types in method declarations
+  /// for remote messaging. They are meant for the arguments though and
+  /// applied to the Decls (ObjCMethodDecl and ParmVarDecl).
+  enum ObjCDeclQualifier {
+    OBJC_TQ_None = 0x0,
+    OBJC_TQ_In = 0x1,
+    OBJC_TQ_Inout = 0x2,
+    OBJC_TQ_Out = 0x4,
+    OBJC_TQ_Bycopy = 0x8,
+    OBJC_TQ_Byref = 0x10,
+    OBJC_TQ_Oneway = 0x20
+  };
+    
+private:
+  /// NextDeclInContext - The next declaration within the same lexical
+  /// DeclContext. These pointers form the linked list that is
+  /// traversed via DeclContext's decls_begin()/decls_end().
+  Decl *NextDeclInContext;
+
+  friend class DeclContext;
+
+  struct MultipleDC {
+    DeclContext *SemanticDC;
+    DeclContext *LexicalDC;
+  };
+  
+  
+  /// DeclCtx - Holds either a DeclContext* or a MultipleDC*.
+  /// For declarations that don't contain C++ scope specifiers, it contains
+  /// the DeclContext where the Decl was declared.
+  /// For declarations with C++ scope specifiers, it contains a MultipleDC*
+  /// with the context where it semantically belongs (SemanticDC) and the
+  /// context where it was lexically declared (LexicalDC).
+  /// e.g.:
+  ///
+  ///   namespace A {
+  ///      void f(); // SemanticDC == LexicalDC == 'namespace A'
+  ///   }
+  ///   void A::f(); // SemanticDC == namespace 'A'
+  ///                // LexicalDC == global namespace
+  llvm::PointerUnion<DeclContext*, MultipleDC*> DeclCtx;
+
+  inline bool isInSemaDC() const    { return DeclCtx.is<DeclContext*>(); }
+  inline bool isOutOfSemaDC() const { return DeclCtx.is<MultipleDC*>(); }
+  inline MultipleDC *getMultipleDC() const {
+    return DeclCtx.get<MultipleDC*>();
+  }
+  inline DeclContext *getSemanticDC() const {
+    return DeclCtx.get<DeclContext*>();
+  }
+  
+  /// Loc - The location that this decl.
+  SourceLocation Loc;
+  
+  /// DeclKind - This indicates which class this is.
+  Kind DeclKind   :  8;
+  
+  /// InvalidDecl - This indicates a semantic error occurred.
+  unsigned int InvalidDecl :  1;
+  
+  /// HasAttrs - This indicates whether the decl has attributes or not.
+  unsigned int HasAttrs : 1;
+
+  /// Implicit - Whether this declaration was implicitly generated by
+  /// the implementation rather than explicitly written by the user.
+  bool Implicit : 1;
+
+  /// IdentifierNamespace - This specifies what IDNS_* namespace this lives in.
+  unsigned IdentifierNamespace : 8;
+  
+#ifndef NDEBUG
+  void CheckAccessDeclContext() const;
+#else
+  void CheckAccessDeclContext() const { }
+#endif
+  
+protected:
+  /// Access - Used by C++ decls for the access specifier.
+  // NOTE: VC++ treats enums as signed, avoid using the AccessSpecifier enum
+  unsigned Access : 2;
+  friend class CXXClassMemberWrapper;
+
+  Decl(Kind DK, DeclContext *DC, SourceLocation L) 
+    : NextDeclInContext(0), DeclCtx(DC), 
+      Loc(L), DeclKind(DK), InvalidDecl(0),
+      HasAttrs(false), Implicit(false), 
+      IdentifierNamespace(getIdentifierNamespaceForKind(DK)), Access(AS_none) {
+    if (Decl::CollectingStats()) addDeclKind(DK);
+  }
+
+  virtual ~Decl();
+
+public:
+  SourceLocation getLocation() const { return Loc; }
+  void setLocation(SourceLocation L) { Loc = L; }
+
+  Kind getKind() const { return DeclKind; }
+  const char *getDeclKindName() const;
+  
+  Decl *getNextDeclInContext() { return NextDeclInContext; }
+  const Decl *getNextDeclInContext() const { return NextDeclInContext; }
+
+  DeclContext *getDeclContext() {
+    if (isInSemaDC())
+      return getSemanticDC();
+    return getMultipleDC()->SemanticDC;
+  }
+  const DeclContext *getDeclContext() const {
+    return const_cast<Decl*>(this)->getDeclContext();
+  }
+  
+  void setAccess(AccessSpecifier AS) {
+    Access = AS; 
+    CheckAccessDeclContext();
+  }
+  
+  AccessSpecifier getAccess() const { 
+    CheckAccessDeclContext();
+    return AccessSpecifier(Access); 
+  }
+
+  bool hasAttrs() const { return HasAttrs; }
+  void addAttr(Attr *attr);
+  const Attr *getAttrs() const {
+    if (!HasAttrs) return 0;  // common case, no attributes.
+    return getAttrsImpl();    // Uncommon case, out of line hash lookup.
+  }
+  void swapAttrs(Decl *D);
+  void invalidateAttrs();
+
+  template<typename T> const T *getAttr() const {
+    for (const Attr *attr = getAttrs(); attr; attr = attr->getNext())
+      if (const T *V = dyn_cast<T>(attr))
+        return V;
+    return 0;
+  }
+    
+  template<typename T> bool hasAttr() const {
+    return getAttr<T>() != 0;
+  }
+  
+  /// setInvalidDecl - Indicates the Decl had a semantic error. This
+  /// allows for graceful error recovery.
+  void setInvalidDecl(bool Invalid = true) { InvalidDecl = Invalid; }
+  bool isInvalidDecl() const { return (bool) InvalidDecl; }
+
+  /// isImplicit - Indicates whether the declaration was implicitly
+  /// generated by the implementation. If false, this declaration
+  /// was written explicitly in the source code.
+  bool isImplicit() const { return Implicit; }
+  void setImplicit(bool I = true) { Implicit = I; }
+  
+  unsigned getIdentifierNamespace() const {
+    return IdentifierNamespace;
+  }
+  bool isInIdentifierNamespace(unsigned NS) const {
+    return getIdentifierNamespace() & NS;
+  }
+  static unsigned getIdentifierNamespaceForKind(Kind DK);
+
+  
+  /// getLexicalDeclContext - The declaration context where this Decl was
+  /// lexically declared (LexicalDC). May be different from
+  /// getDeclContext() (SemanticDC).
+  /// e.g.:
+  ///
+  ///   namespace A {
+  ///      void f(); // SemanticDC == LexicalDC == 'namespace A'
+  ///   }
+  ///   void A::f(); // SemanticDC == namespace 'A'
+  ///                // LexicalDC == global namespace
+  DeclContext *getLexicalDeclContext() {
+    if (isInSemaDC())
+      return getSemanticDC();
+    return getMultipleDC()->LexicalDC;
+  }
+  const DeclContext *getLexicalDeclContext() const {
+    return const_cast<Decl*>(this)->getLexicalDeclContext();
+  }
+  
+  /// setDeclContext - Set both the semantic and lexical DeclContext
+  /// to DC.
+  void setDeclContext(DeclContext *DC);
+
+  void setLexicalDeclContext(DeclContext *DC);
+
+  // isDefinedOutsideFunctionOrMethod - This predicate returns true if this
+  // scoped decl is defined outside the current function or method.  This is
+  // roughly global variables and functions, but also handles enums (which could
+  // be defined inside or outside a function etc).
+  bool isDefinedOutsideFunctionOrMethod() const;
+
+  /// getBody - If this Decl represents a declaration for a body of code,
+  ///  such as a function or method definition, this method returns the
+  ///  top-level Stmt* of that body.  Otherwise this method returns null.
+  virtual Stmt* getBody(ASTContext &Context) const { return 0; }
+
+  /// getCompoundBody - Returns getBody(), dyn_casted to a CompoundStmt.
+  CompoundStmt* getCompoundBody(ASTContext &Context) const;
+
+  /// getBodyRBrace - Gets the right brace of the body, if a body exists.
+  /// This works whether the body is a CompoundStmt or a CXXTryStmt.
+  SourceLocation getBodyRBrace(ASTContext &Context) const;
+
+  // global temp stats (until we have a per-module visitor)
+  static void addDeclKind(Kind k);
+  static bool CollectingStats(bool Enable = false);
+  static void PrintStats();
+    
+  /// isTemplateParameter - Determines whether this declartion is a
+  /// template parameter.
+  bool isTemplateParameter() const;
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Decl *) { return true; }
+  static DeclContext *castToDeclContext(const Decl *);
+  static Decl *castFromDeclContext(const DeclContext *);
+  
+  /// Destroy - Call destructors and release memory.
+  virtual void Destroy(ASTContext& C);
+
+  void print(llvm::raw_ostream &Out, ASTContext &Context, 
+             unsigned Indentation = 0);
+  void print(llvm::raw_ostream &Out, ASTContext &Context, 
+             const PrintingPolicy &Policy, unsigned Indentation = 0);
+  static void printGroup(Decl** Begin, unsigned NumDecls,
+                         llvm::raw_ostream &Out, ASTContext &Context, 
+                         const PrintingPolicy &Policy,
+                         unsigned Indentation = 0);
+  void dump(ASTContext &Context);
+
+private:
+  const Attr *getAttrsImpl() const;
+
+};
+
+/// PrettyStackTraceDecl - If a crash occurs, indicate that it happened when
+/// doing something to a specific decl.
+class PrettyStackTraceDecl : public llvm::PrettyStackTraceEntry {
+  Decl *TheDecl;
+  SourceLocation Loc;
+  SourceManager &SM;
+  const char *Message;
+public:
+  PrettyStackTraceDecl(Decl *theDecl, SourceLocation L,
+                       SourceManager &sm, const char *Msg)
+  : TheDecl(theDecl), Loc(L), SM(sm), Message(Msg) {}
+  
+  virtual void print(llvm::raw_ostream &OS) const;
+};  
+  
+
+/// DeclContext - This is used only as base class of specific decl types that
+/// can act as declaration contexts. These decls are (only the top classes
+/// that directly derive from DeclContext are mentioned, not their subclasses):
+///
+///   TranslationUnitDecl
+///   NamespaceDecl
+///   FunctionDecl
+///   TagDecl
+///   ObjCMethodDecl
+///   ObjCContainerDecl
+///   ObjCCategoryImplDecl
+///   ObjCImplementationDecl
+///   LinkageSpecDecl
+///   BlockDecl
+///
+class DeclContext {
+  /// DeclKind - This indicates which class this is.
+  Decl::Kind DeclKind   :  8;
+
+  /// \brief Whether this declaration context also has some external
+  /// storage that contains additional declarations that are lexically
+  /// part of this context.
+  mutable bool ExternalLexicalStorage : 1;
+
+  /// \brief Whether this declaration context also has some external
+  /// storage that contains additional declarations that are visible
+  /// in this context.
+  mutable bool ExternalVisibleStorage : 1;
+
+  /// \brief Pointer to the data structure used to lookup declarations
+  /// within this context, which is a DenseMap<DeclarationName,
+  /// StoredDeclsList>.
+  mutable void* LookupPtr;
+
+  /// FirstDecl - The first declaration stored within this declaration
+  /// context.
+  mutable Decl *FirstDecl;
+
+  /// LastDecl - The last declaration stored within this declaration
+  /// context. FIXME: We could probably cache this value somewhere
+  /// outside of the DeclContext, to reduce the size of DeclContext by
+  /// another pointer.
+  mutable Decl *LastDecl;
+
+protected:
+   DeclContext(Decl::Kind K) 
+     : DeclKind(K), ExternalLexicalStorage(false),
+       ExternalVisibleStorage(false), LookupPtr(0), FirstDecl(0), 
+       LastDecl(0) { }
+
+  void DestroyDecls(ASTContext &C);
+
+public:
+  ~DeclContext();
+
+  Decl::Kind getDeclKind() const {
+    return DeclKind;
+  }
+  const char *getDeclKindName() const;
+
+  /// getParent - Returns the containing DeclContext.
+  DeclContext *getParent() {
+    return cast<Decl>(this)->getDeclContext();
+  }
+  const DeclContext *getParent() const {
+    return const_cast<DeclContext*>(this)->getParent();
+  }
+  
+  /// getLexicalParent - Returns the containing lexical DeclContext. May be
+  /// different from getParent, e.g.:
+  ///
+  ///   namespace A {
+  ///      struct S;
+  ///   }
+  ///   struct A::S {}; // getParent() == namespace 'A'
+  ///                   // getLexicalParent() == translation unit
+  ///
+  DeclContext *getLexicalParent() {
+    return cast<Decl>(this)->getLexicalDeclContext();
+  }
+  const DeclContext *getLexicalParent() const {
+    return const_cast<DeclContext*>(this)->getLexicalParent();
+  }    
+  
+  bool isFunctionOrMethod() const {
+    switch (DeclKind) {
+    case Decl::Block:
+    case Decl::ObjCMethod:
+      return true;
+    default:
+      return DeclKind >= Decl::FunctionFirst && DeclKind <= Decl::FunctionLast;
+    }
+  }
+
+  bool isFileContext() const {
+    return DeclKind == Decl::TranslationUnit || DeclKind == Decl::Namespace;
+  }
+
+  bool isTranslationUnit() const {
+    return DeclKind == Decl::TranslationUnit;
+  }
+
+  bool isRecord() const {
+    return DeclKind >= Decl::RecordFirst && DeclKind <= Decl::RecordLast;
+  }
+
+  bool isNamespace() const {
+    return DeclKind == Decl::Namespace;
+  }
+
+  /// \brief Determines whether this context is dependent on a
+  /// template parameter.
+  bool isDependentContext() const;
+
+  /// isTransparentContext - Determines whether this context is a
+  /// "transparent" context, meaning that the members declared in this
+  /// context are semantically declared in the nearest enclosing
+  /// non-transparent (opaque) context but are lexically declared in
+  /// this context. For example, consider the enumerators of an
+  /// enumeration type: 
+  /// @code
+  /// enum E {
+  ///   Val1 
+  /// };
+  /// @endcode
+  /// Here, E is a transparent context, so its enumerator (Val1) will
+  /// appear (semantically) that it is in the same context of E.
+  /// Examples of transparent contexts include: enumerations (except for
+  /// C++0x scoped enums), C++ linkage specifications, and C++0x
+  /// inline namespaces.
+  bool isTransparentContext() const;
+
+  bool Encloses(DeclContext *DC) const {
+    for (; DC; DC = DC->getParent())
+      if (DC == this)
+        return true;
+    return false;
+  }
+
+  /// getPrimaryContext - There may be many different
+  /// declarations of the same entity (including forward declarations
+  /// of classes, multiple definitions of namespaces, etc.), each with
+  /// a different set of declarations. This routine returns the
+  /// "primary" DeclContext structure, which will contain the
+  /// information needed to perform name lookup into this context.
+  DeclContext *getPrimaryContext();
+
+  /// getLookupContext - Retrieve the innermost non-transparent
+  /// context of this context, which corresponds to the innermost
+  /// location from which name lookup can find the entities in this
+  /// context.
+  DeclContext *getLookupContext();
+  const DeclContext *getLookupContext() const {
+    return const_cast<DeclContext *>(this)->getLookupContext();
+  }
+  
+  /// \brief Retrieve the nearest enclosing namespace context.
+  DeclContext *getEnclosingNamespaceContext();
+  const DeclContext *getEnclosingNamespaceContext() const {
+    return const_cast<DeclContext *>(this)->getEnclosingNamespaceContext();
+  }
+
+  /// getNextContext - If this is a DeclContext that may have other
+  /// DeclContexts that are semantically connected but syntactically
+  /// different, such as C++ namespaces, this routine retrieves the
+  /// next DeclContext in the link. Iteration through the chain of
+  /// DeclContexts should begin at the primary DeclContext and
+  /// continue until this function returns NULL. For example, given:
+  /// @code
+  /// namespace N {
+  ///   int x;
+  /// }
+  /// namespace N {
+  ///   int y;
+  /// }
+  /// @endcode
+  /// The first occurrence of namespace N will be the primary
+  /// DeclContext. Its getNextContext will return the second
+  /// occurrence of namespace N.
+  DeclContext *getNextContext();
+
+  /// decl_iterator - Iterates through the declarations stored
+  /// within this context.
+  class decl_iterator {
+    /// Current - The current declaration.
+    Decl *Current;
+
+  public:
+    typedef Decl*                     value_type;
+    typedef Decl*                     reference;
+    typedef Decl*                     pointer;
+    typedef std::forward_iterator_tag iterator_category;
+    typedef std::ptrdiff_t            difference_type;
+
+    decl_iterator() : Current(0) { }
+    explicit decl_iterator(Decl *C) : Current(C) { }
+
+    reference operator*() const { return Current; }
+    pointer operator->() const { return Current; }
+
+    decl_iterator& operator++() {
+      Current = Current->getNextDeclInContext();
+      return *this;
+    }
+
+    decl_iterator operator++(int) {
+      decl_iterator tmp(*this);
+      ++(*this);
+      return tmp;
+    }
+
+    friend bool operator==(decl_iterator x, decl_iterator y) { 
+      return x.Current == y.Current;
+    }
+    friend bool operator!=(decl_iterator x, decl_iterator y) { 
+      return x.Current != y.Current;
+    }
+  };
+
+  /// decls_begin/decls_end - Iterate over the declarations stored in
+  /// this context. 
+  decl_iterator decls_begin(ASTContext &Context) const;
+  decl_iterator decls_end(ASTContext &Context) const;
+  bool decls_empty(ASTContext &Context) const;
+
+  /// specific_decl_iterator - Iterates over a subrange of
+  /// declarations stored in a DeclContext, providing only those that
+  /// are of type SpecificDecl (or a class derived from it). This
+  /// iterator is used, for example, to provide iteration over just
+  /// the fields within a RecordDecl (with SpecificDecl = FieldDecl).
+  template<typename SpecificDecl>
+  class specific_decl_iterator {
+    /// Current - The current, underlying declaration iterator, which
+    /// will either be NULL or will point to a declaration of
+    /// type SpecificDecl.
+    DeclContext::decl_iterator Current;
+    
+    /// SkipToNextDecl - Advances the current position up to the next
+    /// declaration of type SpecificDecl that also meets the criteria
+    /// required by Acceptable.
+    void SkipToNextDecl() {
+      while (*Current && !isa<SpecificDecl>(*Current))
+        ++Current;
+    }
+
+  public:
+    typedef SpecificDecl* value_type;
+    typedef SpecificDecl* reference;
+    typedef SpecificDecl* pointer;
+    typedef std::iterator_traits<DeclContext::decl_iterator>::difference_type
+      difference_type;
+    typedef std::forward_iterator_tag iterator_category;
+
+    specific_decl_iterator() : Current() { }
+
+    /// specific_decl_iterator - Construct a new iterator over a
+    /// subset of the declarations the range [C,
+    /// end-of-declarations). If A is non-NULL, it is a pointer to a
+    /// member function of SpecificDecl that should return true for
+    /// all of the SpecificDecl instances that will be in the subset
+    /// of iterators. For example, if you want Objective-C instance
+    /// methods, SpecificDecl will be ObjCMethodDecl and A will be
+    /// &ObjCMethodDecl::isInstanceMethod.
+    explicit specific_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
+      SkipToNextDecl();
+    }
+
+    reference operator*() const { return cast<SpecificDecl>(*Current); }
+    pointer operator->() const { return cast<SpecificDecl>(*Current); }
+
+    specific_decl_iterator& operator++() {
+      ++Current;
+      SkipToNextDecl();
+      return *this;
+    }
+
+    specific_decl_iterator operator++(int) {
+      specific_decl_iterator tmp(*this);
+      ++(*this);
+      return tmp;
+    }
+  
+    friend bool
+    operator==(const specific_decl_iterator& x, const specific_decl_iterator& y) {
+      return x.Current == y.Current;
+    }
+  
+    friend bool 
+    operator!=(const specific_decl_iterator& x, const specific_decl_iterator& y) {
+      return x.Current != y.Current;
+    }
+  };
+
+  /// \brief Iterates over a filtered subrange of declarations stored
+  /// in a DeclContext.
+  ///
+  /// This iterator visits only those declarations that are of type
+  /// SpecificDecl (or a class derived from it) and that meet some
+  /// additional run-time criteria. This iterator is used, for
+  /// example, to provide access to the instance methods within an
+  /// Objective-C interface (with SpecificDecl = ObjCMethodDecl and
+  /// Acceptable = ObjCMethodDecl::isInstanceMethod).
+  template<typename SpecificDecl, bool (SpecificDecl::*Acceptable)() const>
+  class filtered_decl_iterator {
+    /// Current - The current, underlying declaration iterator, which
+    /// will either be NULL or will point to a declaration of
+    /// type SpecificDecl.
+    DeclContext::decl_iterator Current;
+    
+    /// SkipToNextDecl - Advances the current position up to the next
+    /// declaration of type SpecificDecl that also meets the criteria
+    /// required by Acceptable.
+    void SkipToNextDecl() {
+      while (*Current &&
+             (!isa<SpecificDecl>(*Current) ||
+              (Acceptable && !(cast<SpecificDecl>(*Current)->*Acceptable)())))
+        ++Current;
+    }
+
+  public:
+    typedef SpecificDecl* value_type;
+    typedef SpecificDecl* reference;
+    typedef SpecificDecl* pointer;
+    typedef std::iterator_traits<DeclContext::decl_iterator>::difference_type
+      difference_type;
+    typedef std::forward_iterator_tag iterator_category;
+
+    filtered_decl_iterator() : Current() { }
+
+    /// specific_decl_iterator - Construct a new iterator over a
+    /// subset of the declarations the range [C,
+    /// end-of-declarations). If A is non-NULL, it is a pointer to a
+    /// member function of SpecificDecl that should return true for
+    /// all of the SpecificDecl instances that will be in the subset
+    /// of iterators. For example, if you want Objective-C instance
+    /// methods, SpecificDecl will be ObjCMethodDecl and A will be
+    /// &ObjCMethodDecl::isInstanceMethod.
+    explicit filtered_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
+      SkipToNextDecl();
+    }
+
+    reference operator*() const { return cast<SpecificDecl>(*Current); }
+    pointer operator->() const { return cast<SpecificDecl>(*Current); }
+
+    filtered_decl_iterator& operator++() {
+      ++Current;
+      SkipToNextDecl();
+      return *this;
+    }
+
+    filtered_decl_iterator operator++(int) {
+      filtered_decl_iterator tmp(*this);
+      ++(*this);
+      return tmp;
+    }
+  
+    friend bool
+    operator==(const filtered_decl_iterator& x, const filtered_decl_iterator& y) {
+      return x.Current == y.Current;
+    }
+  
+    friend bool 
+    operator!=(const filtered_decl_iterator& x, const filtered_decl_iterator& y) {
+      return x.Current != y.Current;
+    }
+  };
+
+  /// @brief Add the declaration D into this context.
+  ///
+  /// This routine should be invoked when the declaration D has first
+  /// been declared, to place D into the context where it was
+  /// (lexically) defined. Every declaration must be added to one
+  /// (and only one!) context, where it can be visited via
+  /// [decls_begin(), decls_end()). Once a declaration has been added
+  /// to its lexical context, the corresponding DeclContext owns the
+  /// declaration.
+  ///
+  /// If D is also a NamedDecl, it will be made visible within its
+  /// semantic context via makeDeclVisibleInContext.
+  void addDecl(ASTContext &Context, Decl *D);
+
+  /// lookup_iterator - An iterator that provides access to the results
+  /// of looking up a name within this context.
+  typedef NamedDecl **lookup_iterator;
+
+  /// lookup_const_iterator - An iterator that provides non-mutable
+  /// access to the results of lookup up a name within this context.
+  typedef NamedDecl * const * lookup_const_iterator;
+
+  typedef std::pair<lookup_iterator, lookup_iterator> lookup_result;
+  typedef std::pair<lookup_const_iterator, lookup_const_iterator>
+    lookup_const_result;
+
+  /// lookup - Find the declarations (if any) with the given Name in
+  /// this context. Returns a range of iterators that contains all of
+  /// the declarations with this name, with object, function, member,
+  /// and enumerator names preceding any tag name. Note that this
+  /// routine will not look into parent contexts.
+  lookup_result lookup(ASTContext &Context, DeclarationName Name);
+  lookup_const_result lookup(ASTContext &Context, DeclarationName Name) const;
+
+  /// @brief Makes a declaration visible within this context.
+  ///
+  /// This routine makes the declaration D visible to name lookup
+  /// within this context and, if this is a transparent context,
+  /// within its parent contexts up to the first enclosing
+  /// non-transparent context. Making a declaration visible within a
+  /// context does not transfer ownership of a declaration, and a
+  /// declaration can be visible in many contexts that aren't its
+  /// lexical context.
+  ///
+  /// If D is a redeclaration of an existing declaration that is
+  /// visible from this context, as determined by
+  /// NamedDecl::declarationReplaces, the previous declaration will be
+  /// replaced with D.
+  void makeDeclVisibleInContext(ASTContext &Context, NamedDecl *D);
+
+  /// udir_iterator - Iterates through the using-directives stored
+  /// within this context.
+  typedef UsingDirectiveDecl * const * udir_iterator;
+  
+  typedef std::pair<udir_iterator, udir_iterator> udir_iterator_range;
+
+  udir_iterator_range getUsingDirectives(ASTContext &Context) const;
+
+  udir_iterator using_directives_begin(ASTContext &Context) const {
+    return getUsingDirectives(Context).first;
+  }
+
+  udir_iterator using_directives_end(ASTContext &Context) const {
+    return getUsingDirectives(Context).second;
+  }
+
+  // Low-level accessors
+
+  /// \brief Retrieve the internal representation of the lookup structure.
+  void* getLookupPtr() const { return LookupPtr; }
+
+  /// \brief Whether this DeclContext has external storage containing
+  /// additional declarations that are lexically in this context.
+  bool hasExternalLexicalStorage() const { return ExternalLexicalStorage; }
+
+  /// \brief State whether this DeclContext has external storage for
+  /// declarations lexically in this context.
+  void setHasExternalLexicalStorage(bool ES = true) { 
+    ExternalLexicalStorage = ES; 
+  }
+
+  /// \brief Whether this DeclContext has external storage containing
+  /// additional declarations that are visible in this context.
+  bool hasExternalVisibleStorage() const { return ExternalVisibleStorage; }
+
+  /// \brief State whether this DeclContext has external storage for
+  /// declarations visible in this context.
+  void setHasExternalVisibleStorage(bool ES = true) { 
+    ExternalVisibleStorage = ES; 
+  }
+
+  static bool classof(const Decl *D);
+  static bool classof(const DeclContext *D) { return true; }
+#define DECL_CONTEXT(Name) \
+  static bool classof(const Name##Decl *D) { return true; }
+#include "clang/AST/DeclNodes.def"
+
+private:
+  void LoadLexicalDeclsFromExternalStorage(ASTContext &Context) const;
+  void LoadVisibleDeclsFromExternalStorage(ASTContext &Context) const;
+
+  void buildLookup(ASTContext &Context, DeclContext *DCtx);
+  void makeDeclVisibleInContextImpl(ASTContext &Context, NamedDecl *D);
+};
+
+inline bool Decl::isTemplateParameter() const {
+  return getKind() == TemplateTypeParm || getKind() == NonTypeTemplateParm;
+}
+
+inline bool Decl::isDefinedOutsideFunctionOrMethod() const {
+  if (getDeclContext())
+    return !getDeclContext()->getLookupContext()->isFunctionOrMethod();
+  return true;
+}
+
+} // end clang.
+
+namespace llvm {
+
+/// Implement a isa_impl_wrap specialization to check whether a DeclContext is
+/// a specific Decl.
+template<class ToTy>
+struct isa_impl_wrap<ToTy,
+                     const ::clang::DeclContext,const ::clang::DeclContext> {
+  static bool doit(const ::clang::DeclContext &Val) {
+    return ToTy::classof(::clang::Decl::castFromDeclContext(&Val));
+  }
+};
+template<class ToTy>
+struct isa_impl_wrap<ToTy, ::clang::DeclContext, ::clang::DeclContext>
+  : public isa_impl_wrap<ToTy,
+                      const ::clang::DeclContext,const ::clang::DeclContext> {};
+
+/// Implement cast_convert_val for Decl -> DeclContext conversions.
+template<class FromTy>
+struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
+  static ::clang::DeclContext &doit(const FromTy &Val) {
+    return *FromTy::castToDeclContext(&Val);
+  }
+};
+
+template<class FromTy>
+struct cast_convert_val< ::clang::DeclContext, FromTy*, FromTy*> {
+  static ::clang::DeclContext *doit(const FromTy *Val) {
+    return FromTy::castToDeclContext(Val);
+  }
+};
+
+template<class FromTy>
+struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
+  static const ::clang::DeclContext &doit(const FromTy &Val) {
+    return *FromTy::castToDeclContext(&Val);
+  }
+};
+
+template<class FromTy>
+struct cast_convert_val< const ::clang::DeclContext, FromTy*, FromTy*> {
+  static const ::clang::DeclContext *doit(const FromTy *Val) {
+    return FromTy::castToDeclContext(Val);
+  }
+};
+
+/// Implement cast_convert_val for DeclContext -> Decl conversions.
+template<class ToTy>
+struct cast_convert_val<ToTy,
+                        const ::clang::DeclContext,const ::clang::DeclContext> {
+  static ToTy &doit(const ::clang::DeclContext &Val) {
+    return *reinterpret_cast<ToTy*>(ToTy::castFromDeclContext(&Val));
+  }
+};
+template<class ToTy>
+struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext>
+  : public cast_convert_val<ToTy,
+                      const ::clang::DeclContext,const ::clang::DeclContext> {};
+
+template<class ToTy>
+struct cast_convert_val<ToTy,
+                     const ::clang::DeclContext*, const ::clang::DeclContext*> {
+  static ToTy *doit(const ::clang::DeclContext *Val) {
+    return reinterpret_cast<ToTy*>(ToTy::castFromDeclContext(Val));
+  }
+};
+template<class ToTy>
+struct cast_convert_val<ToTy, ::clang::DeclContext*, ::clang::DeclContext*>
+  : public cast_convert_val<ToTy,
+                    const ::clang::DeclContext*,const ::clang::DeclContext*> {};
+
+} // end namespace llvm
+
+#endif