1 //===- DeclVisitor.h - Visitor for Decl subclasses --------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines the DeclVisitor interface. 10 // 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/DeclBase.h" 18 #include "clang/AST/DeclCXX.h" 19 #include "clang/AST/DeclFriend.h" 20 #include "clang/AST/DeclObjC.h" 21 #include "clang/AST/DeclOpenMP.h" 22 #include "clang/AST/DeclTemplate.h" 23 #include "llvm/ADT/STLExtras.h" 24 #include "llvm/Support/ErrorHandling.h" 25 26 namespace clang { 27 28 namespace declvisitor { 29 /// A simple visitor class that helps create declaration visitors. 30 template<template <typename> class Ptr, typename ImplClass, typename RetTy=void> 31 class Base { 32 public: 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 } // namespace declvisitor 60 61 /// A simple visitor class that helps create declaration visitors. 62 /// 63 /// This class does not preserve constness of Decl pointers (see also 64 /// ConstDeclVisitor). 65 template <typename ImplClass, typename RetTy = void> 66 class DeclVisitor 67 : public declvisitor::Base<std::add_pointer, ImplClass, RetTy> {}; 68 69 /// A simple visitor class that helps create declaration visitors. 70 /// 71 /// This class preserves constness of Decl pointers (see also DeclVisitor). 72 template <typename ImplClass, typename RetTy = void> 73 class ConstDeclVisitor 74 : public declvisitor::Base<llvm::make_const_ptr, ImplClass, RetTy> {}; 75 76 } // namespace clang 77 78 #endif // LLVM_CLANG_AST_DECLVISITOR_H 79