AttrIterator.h source code [clang_source_code/include/clang/AST/AttrIterator.h]

1	//===- AttrIterator.h - Classes for attribute iteration ---------- 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 Attr vector and specific_attr_iterator interfaces.
10	//
11	//===----------------------------------------------------------------------===//
12
13	#ifndef LLVM_CLANG_AST_ATTRITERATOR_H
14	#define LLVM_CLANG_AST_ATTRITERATOR_H
15
16	#include "clang/Basic/LLVM.h"
17	#include "llvm/ADT/SmallVector.h"
18	#include "llvm/Support/Casting.h"
19	#include <cassert>
20	#include <cstddef>
21	#include <iterator>
22
23	namespace clang {
24
25	class ASTContext;
26	class Attr;
27
28	/// AttrVec - A vector of Attr, which is how they are stored on the AST.
29	using AttrVec = SmallVector<Attr *, 4>;
30
31	/// specific_attr_iterator - Iterates over a subrange of an AttrVec, only
32	/// providing attributes that are of a specific type.
33	template <typename SpecificAttr, typename Container = AttrVec>
34	class specific_attr_iterator {
35	using Iterator = typename Container::const_iterator;
36
37	/// Current - The current, underlying iterator.
38	/// In order to ensure we don't dereference an invalid iterator unless
39	/// specifically requested, we don't necessarily advance this all the
40	/// way. Instead, we advance it when an operation is requested; if the
41	/// operation is acting on what should be a past-the-end iterator,
42	/// then we offer no guarantees, but this way we do not dereference a
43	/// past-the-end iterator when we move to a past-the-end position.
44	mutable Iterator Current;
45
46	void AdvanceToNext() const {
47	while (!isa<SpecificAttr>(*Current))
48	++Current;
49	}
50
51	void AdvanceToNext(Iterator I) const {
52	while (Current != I && !isa<SpecificAttr>(*Current))
53	++Current;
54	}
55
56	public:
57	using value_type = SpecificAttr *;
58	using reference = SpecificAttr *;
59	using pointer = SpecificAttr *;
60	using iterator_category = std::forward_iterator_tag;
61	using difference_type = std::ptrdiff_t;
62
63	specific_attr_iterator() = default;
64	explicit specific_attr_iterator(Iterator i) : Current(i) {}
65
66	reference operator*() const {
67	AdvanceToNext();
68	return cast<SpecificAttr>(*Current);
69	}
70	pointer operator->() const {
71	AdvanceToNext();
72	return cast<SpecificAttr>(*Current);
73	}
74
75	specific_attr_iterator& operator++() {
76	++Current;
77	return *this;
78	}
79	specific_attr_iterator operator++(int) {
80	specific_attr_iterator Tmp(*this);
81	++(*this);
82	return Tmp;
83	}
84
85	friend bool operator==(specific_attr_iterator Left,
86	specific_attr_iterator Right) {
87	assert((Left.Current == nullptr) == (Right.Current == nullptr));
88	if (Left.Current < Right.Current)
89	Left.AdvanceToNext(Right.Current);
90	else
91	Right.AdvanceToNext(Left.Current);
92	return Left.Current == Right.Current;
93	}
94	friend bool operator!=(specific_attr_iterator Left,
95	specific_attr_iterator Right) {
96	return !(Left == Right);
97	}
98	};
99
100	template <typename SpecificAttr, typename Container>
101	inline specific_attr_iterator<SpecificAttr, Container>
102	specific_attr_begin(const Container& container) {
103	return specific_attr_iterator<SpecificAttr, Container>(container.begin());
104	}
105	template <typename SpecificAttr, typename Container>
106	inline specific_attr_iterator<SpecificAttr, Container>
107	specific_attr_end(const Container& container) {
108	return specific_attr_iterator<SpecificAttr, Container>(container.end());
109	}
110
111	template <typename SpecificAttr, typename Container>
112	inline bool hasSpecificAttr(const Container& container) {
113	return specific_attr_begin<SpecificAttr>(container) !=
114	specific_attr_end<SpecificAttr>(container);
115	}
116	template <typename SpecificAttr, typename Container>
117	inline SpecificAttr *getSpecificAttr(const Container& container) {
118	specific_attr_iterator<SpecificAttr, Container> i =
119	specific_attr_begin<SpecificAttr>(container);
120	if (i != specific_attr_end<SpecificAttr>(container))
121	return *i;
122	else
123	return nullptr;
124	}
125
126	} // namespace clang
127
128	#endif // LLVM_CLANG_AST_ATTRITERATOR_H
129

clang::specific_attr_iterator::Current

clang::specific_attr_iterator::AdvanceToNext

Clang Project