clang  10.0.0svn
AttrVisitor.h
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1 //===- AttrVisitor.h - Visitor for Attr 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 AttrVisitor interface.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_AST_ATTRVISITOR_H
14 #define LLVM_CLANG_AST_ATTRVISITOR_H
15 
16 #include "clang/AST/Attr.h"
17 
18 namespace clang {
19 
20 namespace attrvisitor {
21 
22 /// A simple visitor class that helps create attribute visitors.
23 template <template <typename> class Ptr, typename ImplClass,
24  typename RetTy = void, class... ParamTys>
25 class Base {
26 public:
27 #define PTR(CLASS) typename Ptr<CLASS>::type
28 #define DISPATCH(NAME) \
29  return static_cast<ImplClass *>(this)->Visit##NAME(static_cast<PTR(NAME)>(A))
30 
31  RetTy Visit(PTR(Attr) A) {
32  switch (A->getKind()) {
33 
34 #define ATTR(NAME) \
35  case attr::NAME: \
36  DISPATCH(NAME##Attr);
37 #include "clang/Basic/AttrList.inc"
38  }
39  llvm_unreachable("Attr that isn't part of AttrList.inc!");
40  }
41 
42  // If the implementation chooses not to implement a certain visit
43  // method, fall back to the parent.
44 #define ATTR(NAME) \
45  RetTy Visit##NAME##Attr(PTR(NAME##Attr) A) { DISPATCH(Attr); }
46 #include "clang/Basic/AttrList.inc"
47 
48  RetTy VisitAttr(PTR(Attr)) { return RetTy(); }
49 
50 #undef PTR
51 #undef DISPATCH
52 };
53 
54 } // namespace attrvisitor
55 
56 /// A simple visitor class that helps create attribute visitors.
57 ///
58 /// This class does not preserve constness of Attr pointers (see
59 /// also ConstAttrVisitor).
60 template <typename ImplClass, typename RetTy = void, typename... ParamTys>
61 class AttrVisitor : public attrvisitor::Base<std::add_pointer, ImplClass, RetTy,
62  ParamTys...> {};
63 
64 /// A simple visitor class that helps create attribute visitors.
65 ///
66 /// This class preserves constness of Attr pointers (see also
67 /// AttrVisitor).
68 template <typename ImplClass, typename RetTy = void, typename... ParamTys>
70  : public attrvisitor::Base<llvm::make_const_ptr, ImplClass, RetTy,
71  ParamTys...> {};
72 
73 } // namespace clang
74 
75 #endif // LLVM_CLANG_AST_ATTRVISITOR_H
A simple visitor class that helps create attribute visitors.
Definition: AttrVisitor.h:69
RetTy Visit(PTR(Attr) A)
Definition: AttrVisitor.h:31
Dataflow Directional Tag Classes.
RetTy VisitAttr(PTR(Attr))
Definition: AttrVisitor.h:48
#define PTR(CLASS)
Definition: AttrVisitor.h:27
A simple visitor class that helps create attribute visitors.
Definition: AttrVisitor.h:25
attr::Kind getKind() const
Definition: Attr.h:85
A simple visitor class that helps create attribute visitors.
Definition: AttrVisitor.h:61
Attr - This represents one attribute.
Definition: Attr.h:45