- //===- CommentVisitor.h - Visitor for Comment subclasses --------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_CLANG_AST_COMMENTVISITOR_H 
- #define LLVM_CLANG_AST_COMMENTVISITOR_H 
-   
- #include "clang/AST/Comment.h" 
- #include "llvm/ADT/STLExtras.h" 
- #include "llvm/Support/ErrorHandling.h" 
-   
- namespace clang { 
- namespace comments { 
- template <template <typename> class Ptr, typename ImplClass, 
-           typename RetTy = void, class... ParamTys> 
- class CommentVisitorBase { 
- public: 
- #define PTR(CLASS) typename Ptr<CLASS>::type 
- #define DISPATCH(NAME, CLASS)                                                  \ 
-   return static_cast<ImplClass *>(this)->visit##NAME(                          \ 
-       static_cast<PTR(CLASS)>(C), std::forward<ParamTys>(P)...) 
-   
-   RetTy visit(PTR(Comment) C, ParamTys... P) { 
-     if (!C) 
-       return RetTy(); 
-   
-     switch (C->getCommentKind()) { 
-     default: llvm_unreachable("Unknown comment kind!"); 
- #define ABSTRACT_COMMENT(COMMENT) 
- #define COMMENT(CLASS, PARENT) \ 
-     case Comment::CLASS##Kind: DISPATCH(CLASS, CLASS); 
- #include "clang/AST/CommentNodes.inc" 
- #undef ABSTRACT_COMMENT 
- #undef COMMENT 
-     } 
-   } 
-   
-   // If the derived class does not implement a certain Visit* method, fall back 
-   // on Visit* method for the superclass. 
- #define ABSTRACT_COMMENT(COMMENT) COMMENT 
- #define COMMENT(CLASS, PARENT)                                                 \ 
-   RetTy visit##CLASS(PTR(CLASS) C, ParamTys... P) { DISPATCH(PARENT, PARENT); } 
- #include "clang/AST/CommentNodes.inc" 
- #undef ABSTRACT_COMMENT 
- #undef COMMENT 
-   
-   RetTy visitComment(PTR(Comment) C, ParamTys... P) { return RetTy(); } 
-   
- #undef PTR 
- #undef DISPATCH 
- }; 
-   
- template <typename ImplClass, typename RetTy = void, class... ParamTys> 
- class CommentVisitor : public CommentVisitorBase<std::add_pointer, ImplClass, 
-                                                  RetTy, ParamTys...> {}; 
-   
- template <typename ImplClass, typename RetTy = void, class... ParamTys> 
- class ConstCommentVisitor 
-     : public CommentVisitorBase<llvm::make_const_ptr, ImplClass, RetTy, 
-                                 ParamTys...> {}; 
-   
- } // namespace comments 
- } // namespace clang 
-   
- #endif // LLVM_CLANG_AST_COMMENTVISITOR_H 
-