clang  9.0.0svn
DeclVisitor.h
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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>
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>
74  : public declvisitor::Base<llvm::make_const_ptr, ImplClass, RetTy> {};
75 
76 } // namespace clang
77 
78 #endif // LLVM_CLANG_AST_DECLVISITOR_H
#define PTR(CLASS)
Definition: DeclVisitor.h:33
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
Defines the C++ template declaration subclasses.
A simple visitor class that helps create declaration visitors.
Definition: DeclVisitor.h:31
This file defines OpenMP nodes for declarative directives.
A simple visitor class that helps create declaration visitors.
Definition: DeclVisitor.h:66
Dataflow Directional Tag Classes.
Kind getKind() const
Definition: DeclBase.h:423
RetTy Visit(PTR(Decl) D)
Definition: DeclVisitor.h:37
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
RetTy VisitDecl(PTR(Decl) D)
Definition: DeclVisitor.h:53
A simple visitor class that helps create declaration visitors.
Definition: DeclVisitor.h:73