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/DeclOpenMP.h"
21#include "clang/AST/DeclTemplate.h"
22
23namespace clang {
24namespace declvisitor {
25
26template <typename T> struct make_ptr       { typedef       T *type; };
27template <typename T> struct make_const_ptr { typedef const T *type; };
28
29/// \brief A simple visitor class that helps create declaration visitors.
30template<template <typename> class Ptr, typename ImplClass, typename RetTy=void>
31class Base {
32public:
33
34#define PTR(CLASS) typename Ptr<CLASS>::type
35#define DISPATCH(NAME, CLASS) \
36  return static_cast<ImplClass*>(this)->Visit##NAME(static_cast<PTR(CLASS)>(D))
37
38  RetTy Visit(PTR(Decl) D) {
39    switch (D->getKind()) {
40#define DECL(DERIVED, BASE) \
41      case Decl::DERIVED: DISPATCH(DERIVED##Decl, DERIVED##Decl);
42#define ABSTRACT_DECL(DECL)
43#include "clang/AST/DeclNodes.inc"
44    }
45    llvm_unreachable("Decl that isn't part of DeclNodes.inc!");
46  }
47
48  // If the implementation chooses not to implement a certain visit
49  // method, fall back to the parent.
50#define DECL(DERIVED, BASE) \
51  RetTy Visit##DERIVED##Decl(PTR(DERIVED##Decl) D) { DISPATCH(BASE, BASE); }
52#include "clang/AST/DeclNodes.inc"
53
54  RetTy VisitDecl(PTR(Decl) D) { return RetTy(); }
55
56#undef PTR
57#undef DISPATCH
58};
59
60} // end namespace declvisitor
61
62/// \brief A simple visitor class that helps create declaration visitors.
63///
64/// This class does not preserve constness of Decl pointers (see also
65/// ConstDeclVisitor).
66template<typename ImplClass, typename RetTy=void>
67class DeclVisitor
68 : public declvisitor::Base<declvisitor::make_ptr, ImplClass, RetTy> {};
69
70/// \brief A simple visitor class that helps create declaration visitors.
71///
72/// This class preserves constness of Decl pointers (see also DeclVisitor).
73template<typename ImplClass, typename RetTy=void>
74class ConstDeclVisitor
75 : public declvisitor::Base<declvisitor::make_const_ptr, ImplClass, RetTy> {};
76
77}  // end namespace clang
78
79#endif // LLVM_CLANG_AST_DECLVISITOR_H
80