path: root/include/clang/Parse/Action.h

//===--- Action.h - Parser Action Interface ---------------------*- 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 Action and EmptyAction interface.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_PARSE_ACTION_H
#define LLVM_CLANG_PARSE_ACTION_H

#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Parse/AccessSpecifier.h"
#include "clang/Parse/Ownership.h"

namespace clang {
  // Semantic.
  class DeclSpec;
  class ObjCDeclSpec;
  class CXXScopeSpec;
  class Declarator;
  class AttributeList;
  struct FieldDeclarator;
  // Parse.
  class Scope;
  class Action;
  class Selector;
  class InitListDesignations;
  // Lex.
  class Preprocessor;
  class Token;

/// Action - As the parser reads the input file and recognizes the productions
/// of the grammar, it invokes methods on this class to turn the parsed input
/// into something useful: e.g. a parse tree.
///
/// The callback methods that this class provides are phrased as actions that
/// the parser has just done or is about to do when the method is called.  They
/// are not requests that the actions module do the specified action.
///
/// All of the methods here are optional except isTypeName() and
/// isCurrentClassName(), which must be specified in order for the
/// parse to complete accurately.  The MinimalAction class does this
/// bare-minimum of tracking to implement this functionality.
class Action : public ActionBase {
public:
  /// Out-of-line virtual destructor to provide home for this class.
  virtual ~Action();

  // Types - Though these don't actually enforce strong typing, they document
  // what types are required to be identical for the actions.
  typedef ActionBase::ExprTy ExprTy;
  typedef ActionBase::StmtTy StmtTy;
  typedef void DeclTy;
  typedef void TypeTy;
  typedef void AttrTy;
  typedef void BaseTy;
  typedef void MemInitTy;
  typedef void CXXScopeTy;

  /// Expr/Stmt/Type/BaseResult - Provide a unique type to wrap
  /// ExprTy/StmtTy/TypeTy/BaseTy, providing strong typing and
  /// allowing for failure.
  typedef ActionResult<0> ExprResult;
  typedef ActionResult<1> StmtResult;
  typedef ActionResult<2> TypeResult;
  typedef ActionResult<3> BaseResult;
  typedef ActionResult<4> MemInitResult;

  /// Same, but with ownership.
  typedef ASTOwningResult<&ActionBase::DeleteExpr> OwningExprResult;
  typedef ASTOwningResult<&ActionBase::DeleteStmt> OwningStmtResult;
  // Note that these will replace ExprResult and StmtResult when the transition
  // is complete.

  /// Single expressions or statements as arguments.
  typedef ASTOwningPtr<&ActionBase::DeleteExpr> ExprArg;
  typedef ASTOwningPtr<&ActionBase::DeleteStmt> StmtArg;

  /// Multiple expressions or statements as arguments.
  typedef ASTMultiPtr<&ActionBase::DeleteExpr> MultiExprArg;
  typedef ASTMultiPtr<&ActionBase::DeleteStmt> MultiStmtArg;

  /// Statistics.
  virtual void PrintStats() const {}
  //===--------------------------------------------------------------------===//
  // Declaration Tracking Callbacks.
  //===--------------------------------------------------------------------===//
  
  /// isTypeName - Return non-null if the specified identifier is a type name
  /// in the current scope.
  /// An optional CXXScopeSpec can be passed to indicate the C++ scope (class or
  /// namespace) that the identifier must be a member of.
  /// i.e. for "foo::bar", 'II' will be "bar" and 'SS' will be "foo::".
  virtual TypeTy *isTypeName(IdentifierInfo &II, Scope *S,
                             const CXXScopeSpec *SS = 0) = 0;

  /// isCurrentClassName - Return true if the specified name is the
  /// name of the innermost C++ class type currently being defined.
  virtual bool isCurrentClassName(const IdentifierInfo &II, Scope *S,
                                  const CXXScopeSpec *SS = 0) = 0;

  /// ActOnCXXGlobalScopeSpecifier - Return the object that represents the
  /// global scope ('::').
  virtual CXXScopeTy *ActOnCXXGlobalScopeSpecifier(Scope *S,
                                                   SourceLocation CCLoc) {
    return 0;
  }

  /// ActOnCXXNestedNameSpecifier - Called during parsing of a
  /// nested-name-specifier. e.g. for "foo::bar::" we parsed "foo::" and now
  /// we want to resolve "bar::". 'SS' is empty or the previously parsed
  /// nested-name part ("foo::"), 'IdLoc' is the source location of 'bar',
  /// 'CCLoc' is the location of '::' and 'II' is the identifier for 'bar'.
  /// Returns a CXXScopeTy* object representing the C++ scope.
  virtual CXXScopeTy *ActOnCXXNestedNameSpecifier(Scope *S,
                                                  const CXXScopeSpec &SS,
                                                  SourceLocation IdLoc,
                                                  SourceLocation CCLoc,
                                                  IdentifierInfo &II) {
    return 0;
  }

  /// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global
  /// scope or nested-name-specifier) is parsed, part of a