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 14 #ifndef LLVM_CLANG_AST_DECLVISITOR_H 15 #define LLVM_CLANG_AST_DECLVISITOR_H 16 17 #include "clang/AST/Decl.h" 18 #include "clang/AST/DeclBase.h" 19 #include "clang/AST/DeclCXX.h" 20 #include "clang/AST/DeclFriend.h" 21 #include "clang/AST/DeclObjC.h" 22 #include "clang/AST/DeclOpenMP.h" 23 #include "clang/AST/DeclTemplate.h" 24 #include "llvm/Support/ErrorHandling.h" 25 26 namespace clang { 27 28 namespace declvisitor { 29 30 template <typename T> struct make_ptr { using type = T *; }; 31 template <typename T> struct make_const_ptr { using type = const T *; }; 32 33 /// A simple visitor class that helps create declaration visitors. 34 template<template <typename> class Ptr, typename ImplClass, typename RetTy=void> 35 class Base { 36 public: 37 #define PTR(CLASS) typename Ptr<CLASS>::type 38 #define DISPATCH(NAME, CLASS) \ 39 return static_cast<ImplClass*>(this)->Visit##NAME(static_cast<PTR(CLASS)>(D)) 40 Visit(PTR (Decl)D)41 RetTy Visit(PTR(Decl) D) { 42 switch (D->getKind()) { 43 #define DECL(DERIVED, BASE) \ 44 case Decl::DERIVED: DISPATCH(DERIVED##Decl, DERIVED##Decl); 45 #define ABSTRACT_DECL(DECL) 46 #include "clang/AST/DeclNodes.inc" 47 } 48 llvm_unreachable("Decl that isn't part of DeclNodes.inc!"); 49 } 50 51 // If the implementation chooses not to implement a certain visit 52 // method, fall back to the parent. 53 #define DECL(DERIVED, BASE) \ 54 RetTy Visit##DERIVED##Decl(PTR(DERIVED##Decl) D) { DISPATCH(BASE, BASE); } 55 #include "clang/AST/DeclNodes.inc" 56 VisitDecl(PTR (Decl)D)57 RetTy VisitDecl(PTR(Decl) D) { return RetTy(); } 58 59 #undef PTR 60 #undef DISPATCH 61 }; 62 63 } // namespace declvisitor 64 65 /// A simple visitor class that helps create declaration visitors. 66 /// 67 /// This class does not preserve constness of Decl pointers (see also 68 /// ConstDeclVisitor). 69 template<typename ImplClass, typename RetTy = void> 70 class DeclVisitor 71 : public declvisitor::Base<declvisitor::make_ptr, ImplClass, RetTy> {}; 72 73 /// A simple visitor class that helps create declaration visitors. 74 /// 75 /// This class preserves constness of Decl pointers (see also DeclVisitor). 76 template<typename ImplClass, typename RetTy = void> 77 class ConstDeclVisitor 78 : public declvisitor::Base<declvisitor::make_const_ptr, ImplClass, RetTy> {}; 79 80 } // namespace clang 81 82 #endif // LLVM_CLANG_AST_DECLVISITOR_H 83