DeclVisitor.h revision ae54121c15cdd38f415f6fdda48215ab5e4dcee1 
1//===--- DeclVisitor.h - Visitor for Decl subclasses ------------*- 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 DeclVisitor interface.
11//
12//===----------------------------------------------------------------------===//
13#ifndef LLVM_CLANG_AST_DECLVISITOR_H
14#define LLVM_CLANG_AST_DECLVISITOR_H
15
16#include "clang/AST/Decl.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/DeclFriend.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/DeclTemplate.h"
21
22namespace clang {
23namespace declvisitor {
24
25template <typename T> struct make_ptr       { typedef       T *type; };
26template <typename T> struct make_const_ptr { typedef const T *type; };
27
28/// \brief A simple visitor class that helps create declaration visitors.
29template<template <typename> class Ptr, typename ImplClass, typename RetTy=void>
30class Base {
31public:
32
33#define PTR(CLASS) typename Ptr<CLASS>::type
34#define DISPATCH(NAME, CLASS) \
35  return static_cast<ImplClass*>(this)->Visit##NAME(static_cast<PTR(CLASS)>(D))
36
37  RetTy Visit(PTR(Decl) D) {
38    switch (D->getKind()) {
39#define DECL(DERIVED, BASE) \
40      case Decl::DERIVED: DISPATCH(DERIVED##Decl, DERIVED##Decl);
41#define ABSTRACT_DECL(DECL)
42#include "clang/AST/DeclNodes.inc"
43    }
44    llvm_unreachable("Decl that isn't part of DeclNodes.inc!");
45  }
46
47  // If the implementation chooses not to implement a certain visit
48  // method, fall back to the parent.
49#define DECL(DERIVED, BASE) \
50  RetTy Visit##DERIVED##Decl(PTR(DERIVED##Decl) D) { DISPATCH(BASE, BASE); }
51#include "clang/AST/DeclNodes.inc"
52
53  RetTy VisitDecl(PTR(Decl) D) { return RetTy(); }
54
55#undef PTR
56#undef DISPATCH
57};
58
59} // end namespace declvisitor
60
61/// \brief A simple visitor class that helps create declaration visitors.
62///
63/// This class does not preserve constness of Decl pointers (see also
64/// ConstDeclVisitor).
65template<typename ImplClass, typename RetTy=void>
66class DeclVisitor
67 : public declvisitor::Base<declvisitor::make_ptr, ImplClass, RetTy> {};
68
69/// \brief A simple visitor class that helps create declaration visitors.
70///
71/// This class preserves constness of Decl pointers (see also DeclVisitor).
72template<typename ImplClass, typename RetTy=void>
73class ConstDeclVisitor
74 : public declvisitor::Base<declvisitor::make_const_ptr, ImplClass, RetTy> {};
75
76}  // end namespace clang
77
78#endif // LLVM_CLANG_AST_DECLVISITOR_H
79