path: root/include/clang/AST/DeclBase.h

//===-- 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"
#include "clang/Basic/Specifiers.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 ObjCImplDecl;
class LinkageSpecDecl;
class BlockDecl;
class DeclarationName;
class CompoundStmt;
class StoredDeclsMap;
class DependentDiagnostic;
}

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.  We also put
  /// C++ friend declarations (of previously-undeclared entities) in
  /// shadow namespaces, and 'using' declarations (as opposed to their
  /// implicit shadow declarations) can be found in their own
  /// namespace.
  enum IdentifierNamespace {
    IDNS_Label = 0x1,
    IDNS_Tag = 0x2,
    IDNS_Member = 0x4,
    IDNS_Ordinary = 0x8,
    IDNS_ObjCProtocol = 0x10,
    IDNS_ObjCImplementation = 0x20,
    IDNS_ObjCCategoryName = 0x40,
    IDNS_OrdinaryFriend = 0x80,
    IDNS_TagFriend = 0x100,
    IDNS_Using = 0x200
  };

  /// 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