1 //===- AttrIterator.h - Classes for attribute iteration ---------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the Attr vector and specific_attr_iterator interfaces.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_AST_ATTRITERATOR_H
15 #define LLVM_CLANG_AST_ATTRITERATOR_H
17 #include "clang/Basic/LLVM.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/Support/Casting.h"
29 /// AttrVec - A vector of Attr, which is how they are stored on the AST.
30 using AttrVec = SmallVector<Attr *, 4>;
32 /// specific_attr_iterator - Iterates over a subrange of an AttrVec, only
33 /// providing attributes that are of a specific type.
34 template <typename SpecificAttr, typename Container = AttrVec>
35 class specific_attr_iterator {
36 using Iterator = typename Container::const_iterator;
38 /// Current - The current, underlying iterator.
39 /// In order to ensure we don't dereference an invalid iterator unless
40 /// specifically requested, we don't necessarily advance this all the
41 /// way. Instead, we advance it when an operation is requested; if the
42 /// operation is acting on what should be a past-the-end iterator,
43 /// then we offer no guarantees, but this way we do not dereference a
44 /// past-the-end iterator when we move to a past-the-end position.
45 mutable Iterator Current;
47 void AdvanceToNext() const {
48 while (!isa<SpecificAttr>(*Current))
52 void AdvanceToNext(Iterator I) const {
53 while (Current != I && !isa<SpecificAttr>(*Current))
58 using value_type = SpecificAttr *;
59 using reference = SpecificAttr *;
60 using pointer = SpecificAttr *;
61 using iterator_category = std::forward_iterator_tag;
62 using difference_type = std::ptrdiff_t;
64 specific_attr_iterator() = default;
65 explicit specific_attr_iterator(Iterator i) : Current(i) {}
67 reference operator*() const {
69 return cast<SpecificAttr>(*Current);
71 pointer operator->() const {
73 return cast<SpecificAttr>(*Current);
76 specific_attr_iterator& operator++() {
80 specific_attr_iterator operator++(int) {
81 specific_attr_iterator Tmp(*this);
86 friend bool operator==(specific_attr_iterator Left,
87 specific_attr_iterator Right) {
88 assert((Left.Current == nullptr) == (Right.Current == nullptr));
89 if (Left.Current < Right.Current)
90 Left.AdvanceToNext(Right.Current);
92 Right.AdvanceToNext(Left.Current);
93 return Left.Current == Right.Current;
95 friend bool operator!=(specific_attr_iterator Left,
96 specific_attr_iterator Right) {
97 return !(Left == Right);
101 template <typename SpecificAttr, typename Container>
102 inline specific_attr_iterator<SpecificAttr, Container>
103 specific_attr_begin(const Container& container) {
104 return specific_attr_iterator<SpecificAttr, Container>(container.begin());
106 template <typename SpecificAttr, typename Container>
107 inline specific_attr_iterator<SpecificAttr, Container>
108 specific_attr_end(const Container& container) {
109 return specific_attr_iterator<SpecificAttr, Container>(container.end());
112 template <typename SpecificAttr, typename Container>
113 inline bool hasSpecificAttr(const Container& container) {
114 return specific_attr_begin<SpecificAttr>(container) !=
115 specific_attr_end<SpecificAttr>(container);
117 template <typename SpecificAttr, typename Container>
118 inline SpecificAttr *getSpecificAttr(const Container& container) {
119 specific_attr_iterator<SpecificAttr, Container> i =
120 specific_attr_begin<SpecificAttr>(container);
121 if (i != specific_attr_end<SpecificAttr>(container))
129 #endif // LLVM_CLANG_AST_ATTRITERATOR_H