1//===--- AttrIterator.h - Classes for attribute iteration -------*- 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 Attr vector and specific_attr_iterator interfaces.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_ATTRITERATOR_H
15#define LLVM_CLANG_AST_ATTRITERATOR_H
16
17#include "clang/Basic/LLVM.h"
18#include <iterator>
19
20namespace clang {
21  class ASTContext;
22  class Attr;
23}
24
25// Defined in ASTContext.h
26void *operator new(size_t Bytes, const clang::ASTContext &C,
27                   size_t Alignment = 8);
28// FIXME: Being forced to not have a default argument here due to redeclaration
29//        rules on default arguments sucks
30void *operator new[](size_t Bytes, const clang::ASTContext &C,
31                     size_t Alignment);
32
33// It is good practice to pair new/delete operators.  Also, MSVC gives many
34// warnings if a matching delete overload is not declared, even though the
35// throw() spec guarantees it will not be implicitly called.
36void operator delete(void *Ptr, const clang::ASTContext &C, size_t);
37void operator delete[](void *Ptr, const clang::ASTContext &C, size_t);
38
39namespace clang {
40
41/// AttrVec - A vector of Attr, which is how they are stored on the AST.
42typedef SmallVector<Attr *, 4> AttrVec;
43
44/// specific_attr_iterator - Iterates over a subrange of an AttrVec, only
45/// providing attributes that are of a specific type.
46template <typename SpecificAttr, typename Container = AttrVec>
47class specific_attr_iterator {
48  typedef typename Container::const_iterator Iterator;
49
50  /// Current - The current, underlying iterator.
51  /// In order to ensure we don't dereference an invalid iterator unless
52  /// specifically requested, we don't necessarily advance this all the
53  /// way. Instead, we advance it when an operation is requested; if the
54  /// operation is acting on what should be a past-the-end iterator,
55  /// then we offer no guarantees, but this way we do not dereference a
56  /// past-the-end iterator when we move to a past-the-end position.
57  mutable Iterator Current;
58
59  void AdvanceToNext() const {
60    while (!isa<SpecificAttr>(*Current))
61      ++Current;
62  }
63
64  void AdvanceToNext(Iterator I) const {
65    while (Current != I && !isa<SpecificAttr>(*Current))
66      ++Current;
67  }
68
69public:
70  typedef SpecificAttr*             value_type;
71  typedef SpecificAttr*             reference;
72  typedef SpecificAttr*             pointer;
73  typedef std::forward_iterator_tag iterator_category;
74  typedef std::ptrdiff_t            difference_type;
75
76  specific_attr_iterator() : Current() { }
77  explicit specific_attr_iterator(Iterator i) : Current(i) { }
78
79  reference operator*() const {
80    AdvanceToNext();
81    return cast<SpecificAttr>(*Current);
82  }
83  pointer operator->() const {
84    AdvanceToNext();
85    return cast<SpecificAttr>(*Current);
86  }
87
88  specific_attr_iterator& operator++() {
89    ++Current;
90    return *this;
91  }
92  specific_attr_iterator operator++(int) {
93    specific_attr_iterator Tmp(*this);
94    ++(*this);
95    return Tmp;
96  }
97
98  friend bool operator==(specific_attr_iterator Left,
99                         specific_attr_iterator Right) {
100    assert((Left.Current == nullptr) == (Right.Current == nullptr));
101    if (Left.Current < Right.Current)
102      Left.AdvanceToNext(Right.Current);
103    else
104      Right.AdvanceToNext(Left.Current);
105    return Left.Current == Right.Current;
106  }
107  friend bool operator!=(specific_attr_iterator Left,
108                         specific_attr_iterator Right) {
109    return !(Left == Right);
110  }
111};
112
113template <typename SpecificAttr, typename Container>
114inline specific_attr_iterator<SpecificAttr, Container>
115          specific_attr_begin(const Container& container) {
116  return specific_attr_iterator<SpecificAttr, Container>(container.begin());
117}
118template <typename SpecificAttr, typename Container>
119inline specific_attr_iterator<SpecificAttr, Container>
120          specific_attr_end(const Container& container) {
121  return specific_attr_iterator<SpecificAttr, Container>(container.end());
122}
123
124template <typename SpecificAttr, typename Container>
125inline bool hasSpecificAttr(const Container& container) {
126  return specific_attr_begin<SpecificAttr>(container) !=
127          specific_attr_end<SpecificAttr>(container);
128}
129template <typename SpecificAttr, typename Container>
130inline SpecificAttr *getSpecificAttr(const Container& container) {
131  specific_attr_iterator<SpecificAttr, Container> i =
132      specific_attr_begin<SpecificAttr>(container);
133  if (i != specific_attr_end<SpecificAttr>(container))
134    return *i;
135  else
136    return nullptr;
137}
138
139}  // end namespace clang
140
141#endif
142