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 ABSTRACT_DECL(DECL)
#define DECL_RANGE(BASE, START, END) \
        first##BASE = START, last##BASE = END,
#define LAST_DECL_RANGE(BASE, START, END) \
        first##BASE = START, last##BASE = END
#include "clang/AST/DeclNodes.inc"
  };

  /// \brief A placeholder type used to construct an empty shell of a
  /// decl-derived type that will be filled in later (e.g., by some
  /// deserialization method).
  struct EmptyShell { };

  /// IdentifierNamespace - The different namespaces in which
  /// declarations may appear.  According to C99 6.2.3, there are
  /// four namespaces, labels, tags, members and ordinary
  /// identifiers.  C++ describes lookup completely differently:
  /// certain lookups merely "ignore" certain kinds of declarations,
  /// usually based on whether the declaration is of a type, etc.
  /// 
  /// These are meant as bitmasks, so that searches in
  /// C++ can look into the "tag" namespace during ordinary lookup.
  ///
  /// Decl currently provides 16 bits of IDNS bits.
  enum IdentifierNamespace {
    /// Labels, declared with 'x:' and referenced with 'goto x'.
    IDNS_Label               = 0x0001,

    /// Tags, declared with 'struct foo;' and referenced with
    /// 'struct foo'.  All tags are also types.  This is what
    /// elaborated-type-specifiers look for in C.
    IDNS_Tag                 = 0x0002,

    /// Types, declared with 'struct foo', typedefs, etc.
    /// This is what elaborated-type-specifiers look for in C++,
    /// but note that it's ill-formed to find a non-tag.
    IDNS_Type                = 0x0004,

    /// Members, declared with object declarations within tag
    /// definitions.  In C, these can only be found by "qualified"
    /// lookup in member expressions.  In C++, they're found by
    /// normal lookup.
    IDNS_Member              = 0x0008,

    /// Namespaces, declared with 'namespace foo {}'.
    /// Lookup for nested-name-specifiers find these.
    IDNS_Namespace           = 0x0010,

    /// Ordinary names.  In C, everything that's not a label, tag,
    /// or member ends up here.
    IDNS_Ordinary            = 0x0020,

    /// Objective C @protocol.
    IDNS_ObjCProtocol        = 0x0040,

    /// This declaration is a friend function.  A friend function
    /// declaration is always in this namespace but may also be in
    /// IDNS_Ordinary if it was previously declared.
    IDNS_OrdinaryFriend      = 0x0080,

    /// This declaration is a friend class.  A friend class
    /// declaration is always in this namespace but may also be in
    /// IDNS_Tag|IDNS_Type if it was previously declared.
    IDNS_TagFriend           = 0x0100,

    /// This declaration is a using declaration.  A using declaration
    /// *introduces* a number of other declarations into the curren