clang  6.0.0svn
ContinuousRangeMap.h
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1 //===--- ContinuousRangeMap.h - Map with int range as key -------*- 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 ContinuousRangeMap class, which is a highly
11 // specialized container used by serialization.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_SERIALIZATION_CONTINUOUSRANGEMAP_H
16 #define LLVM_CLANG_SERIALIZATION_CONTINUOUSRANGEMAP_H
17 
18 #include "clang/Basic/LLVM.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include <algorithm>
21 #include <utility>
22 
23 namespace clang {
24 
25 /// \brief A map from continuous integer ranges to some value, with a very
26 /// specialized interface.
27 ///
28 /// CRM maps from integer ranges to values. The ranges are continuous, i.e.
29 /// where one ends, the next one begins. So if the map contains the stops I0-3,
30 /// the first range is from I0 to I1, the second from I1 to I2, the third from
31 /// I2 to I3 and the last from I3 to infinity.
32 ///
33 /// Ranges must be inserted in order. Inserting a new stop I4 into the map will
34 /// shrink the fourth range to I3 to I4 and add the new range I4 to inf.
35 template <typename Int, typename V, unsigned InitialCapacity>
37 public:
38  typedef std::pair<Int, V> value_type;
39  typedef value_type &reference;
40  typedef const value_type &const_reference;
41  typedef value_type *pointer;
42  typedef const value_type *const_pointer;
43 
44 private:
46  Representation Rep;
47 
48  struct Compare {
49  bool operator ()(const_reference L, Int R) const {
50  return L.first < R;
51  }
52  bool operator ()(Int L, const_reference R) const {
53  return L < R.first;
54  }
55  bool operator ()(Int L, Int R) const {
56  return L < R;
57  }
58  bool operator ()(const_reference L, const_reference R) const {
59  return L.first < R.first;
60  }
61  };
62 
63 public:
64  void insert(const value_type &Val) {
65  if (!Rep.empty() && Rep.back() == Val)
66  return;
67 
68  assert((Rep.empty() || Rep.back().first < Val.first) &&
69  "Must insert keys in order.");
70  Rep.push_back(Val);
71  }
72 
73  void insertOrReplace(const value_type &Val) {
74  iterator I = std::lower_bound(Rep.begin(), Rep.end(), Val, Compare());
75  if (I != Rep.end() && I->first == Val.first) {
76  I->second = Val.second;
77  return;
78  }
79 
80  Rep.insert(I, Val);
81  }
82 
83  typedef typename Representation::iterator iterator;
84  typedef typename Representation::const_iterator const_iterator;
85 
86  iterator begin() { return Rep.begin(); }
87  iterator end() { return Rep.end(); }
88  const_iterator begin() const { return Rep.begin(); }
89  const_iterator end() const { return Rep.end(); }
90 
91  iterator find(Int K) {
92  iterator I = std::upper_bound(Rep.begin(), Rep.end(), K, Compare());
93  // I points to the first entry with a key > K, which is the range that
94  // follows the one containing K.
95  if (I == Rep.begin())
96  return Rep.end();
97  --I;
98  return I;
99  }
100  const_iterator find(Int K) const {
101  return const_cast<ContinuousRangeMap*>(this)->find(K);
102  }
103 
104  reference back() { return Rep.back(); }
105  const_reference back() const { return Rep.back(); }
106 
107  /// \brief An object that helps properly build a continuous range map
108  /// from a set of values.
109  class Builder {
110  ContinuousRangeMap &Self;
111 
112  Builder(const Builder&) = delete;
113  Builder &operator=(const Builder&) = delete;
114 
115  public:
116  explicit Builder(ContinuousRangeMap &Self) : Self(Self) { }
117 
119  std::sort(Self.Rep.begin(), Self.Rep.end(), Compare());
120  std::unique(Self.Rep.begin(), Self.Rep.end(),
121  [](const_reference A, const_reference B) {
122  // FIXME: we should not allow any duplicate keys, but there are a lot of
123  // duplicate 0 -> 0 mappings to remove first.
124  assert((A == B || A.first != B.first) &&
125  "ContinuousRangeMap::Builder given non-unique keys");
126  return A == B;
127  });
128  }
129 
130  void insert(const value_type &Val) {
131  Self.Rep.push_back(Val);
132  }
133  };
134  friend class Builder;
135 };
136 
137 }
138 
139 #endif
void insert(const value_type &Val)
const_iterator begin() const
std::pair< Int, V > value_type
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
const_reference back() const
void insertOrReplace(const value_type &Val)
Builder(ContinuousRangeMap &Self)
Representation::const_iterator const_iterator
An object that helps properly build a continuous range map from a set of values.
const value_type & const_reference
const value_type * const_pointer
Dataflow Directional Tag Classes.
A map from continuous integer ranges to some value, with a very specialized interface.
const_iterator end() const
const_iterator find(Int K) const
void insert(const value_type &Val)