clang/AST/CommentVisitor.h

0001 //===- CommentVisitor.h - Visitor for Comment subclasses --------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef LLVM_CLANG_AST_COMMENTVISITOR_H
0010 #define LLVM_CLANG_AST_COMMENTVISITOR_H
0011
0012 #include "clang/AST/Comment.h"
0013 #include "llvm/ADT/STLExtras.h"
0014 #include "llvm/Support/ErrorHandling.h"
0015
0016 namespace clang {
0017 namespace comments {
0018 template <template <typename> class Ptr, typename ImplClass,
0019           typename RetTy = void, class... ParamTys>
0020 class CommentVisitorBase {
0021 public:
0022 #define PTR(CLASS) typename Ptr<CLASS>::type
0023 #define DISPATCH(NAME, CLASS)                                                  \
0024   return static_cast<ImplClass *>(this)->visit##NAME(                          \
0025       static_cast<PTR(CLASS)>(C), std::forward<ParamTys>(P)...)
0026
0027   RetTy visit(PTR(Comment) C, ParamTys... P) {
0028     if (!C)
0029       return RetTy();
0030
0031     switch (C->getCommentKind()) {
0032     default: llvm_unreachable("Unknown comment kind!");
0033 #define ABSTRACT_COMMENT(COMMENT)
0034 #define COMMENT(CLASS, PARENT)                                                 \
0035   case CommentKind::CLASS:                                                     \
0036     DISPATCH(CLASS, CLASS);
0037 #include "clang/AST/CommentNodes.inc"
0038 #undef ABSTRACT_COMMENT
0039 #undef COMMENT
0040     }
0041   }
0042
0043   // If the derived class does not implement a certain Visit* method, fall back
0044   // on Visit* method for the superclass.
0045 #define ABSTRACT_COMMENT(COMMENT) COMMENT
0046 #define COMMENT(CLASS, PARENT)                                                 \
0047   RetTy visit##CLASS(PTR(CLASS) C, ParamTys... P) { DISPATCH(PARENT, PARENT); }
0048 #include "clang/AST/CommentNodes.inc"
0049 #undef ABSTRACT_COMMENT
0050 #undef COMMENT
0051
0052   RetTy visitComment(PTR(Comment) C, ParamTys... P) { return RetTy(); }
0053
0054 #undef PTR
0055 #undef DISPATCH
0056 };
0057
0058 template <typename ImplClass, typename RetTy = void, class... ParamTys>
0059 class CommentVisitor : public CommentVisitorBase<std::add_pointer, ImplClass,
0060                                                  RetTy, ParamTys...> {};
0061
0062 template <typename ImplClass, typename RetTy = void, class... ParamTys>
0063 class ConstCommentVisitor
0064     : public CommentVisitorBase<llvm::make_const_ptr, ImplClass, RetTy,
0065                                 ParamTys...> {};
0066
0067 } // namespace comments
0068 } // namespace clang
0069
0070 #endif // LLVM_CLANG_AST_COMMENTVISITOR_H