1//===--- UnicodeCharRanges.h - Types and functions for character ranges ---===//
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#ifndef LLVM_SUPPORT_UNICODECHARRANGES_H
10#define LLVM_SUPPORT_UNICODECHARRANGES_H
11
12#include "llvm/ADT/ArrayRef.h"
13#include "llvm/ADT/SmallPtrSet.h"
14#include "llvm/Support/Compiler.h"
15#include "llvm/Support/Debug.h"
16#include "llvm/Support/Mutex.h"
17#include "llvm/Support/MutexGuard.h"
18#include "llvm/Support/raw_ostream.h"
19#include <algorithm>
20
21namespace llvm {
22namespace sys {
23
24#define DEBUG_TYPE "unicode"
25
26/// \brief Represents a closed range of Unicode code points [Lower, Upper].
27struct UnicodeCharRange {
28  uint32_t Lower;
29  uint32_t Upper;
30};
31
32inline bool operator<(uint32_t Value, UnicodeCharRange Range) {
33  return Value < Range.Lower;
34}
35inline bool operator<(UnicodeCharRange Range, uint32_t Value) {
36  return Range.Upper < Value;
37}
38
39/// \brief Holds a reference to an ordered array of UnicodeCharRange and allows
40/// to quickly check if a code point is contained in the set represented by this
41/// array.
42class UnicodeCharSet {
43public:
44  typedef ArrayRef<UnicodeCharRange> CharRanges;
45
46  /// \brief Constructs a UnicodeCharSet instance from an array of
47  /// UnicodeCharRanges.
48  ///
49  /// Array pointed by \p Ranges should have the lifetime at least as long as
50  /// the UnicodeCharSet instance, and should not change. Array is validated by
51  /// the constructor, so it makes sense to create as few UnicodeCharSet
52  /// instances per each array of ranges, as possible.
53#ifdef NDEBUG
54
55  // FIXME: This could use constexpr + static_assert. This way we
56  // may get rid of NDEBUG in this header. Unfortunately there are some
57  // problems to get this working with MSVC 2013. Change this when
58  // the support for MSVC 2013 is dropped.
59  constexpr UnicodeCharSet(CharRanges Ranges) : Ranges(Ranges) {}
60#else
61  UnicodeCharSet(CharRanges Ranges) : Ranges(Ranges) {
62    assert(rangesAreValid());
63  }
64#endif
65
66  /// \brief Returns true if the character set contains the Unicode code point
67  /// \p C.
68  bool contains(uint32_t C) const {
69    return std::binary_search(Ranges.begin(), Ranges.end(), C);
70  }
71
72private:
73  /// \brief Returns true if each of the ranges is a proper closed range
74  /// [min, max], and if the ranges themselves are ordered and non-overlapping.
75  bool rangesAreValid() const {
76    uint32_t Prev = 0;
77    for (CharRanges::const_iterator I = Ranges.begin(), E = Ranges.end();
78         I != E; ++I) {
79      if (I != Ranges.begin() && Prev >= I->Lower) {
80        DEBUG(dbgs() << "Upper bound 0x");
81        DEBUG(dbgs().write_hex(Prev));
82        DEBUG(dbgs() << " should be less than succeeding lower bound 0x");
83        DEBUG(dbgs().write_hex(I->Lower) << "\n");
84        return false;
85      }
86      if (I->Upper < I->Lower) {
87        DEBUG(dbgs() << "Upper bound 0x");
88        DEBUG(dbgs().write_hex(I->Lower));
89        DEBUG(dbgs() << " should not be less than lower bound 0x");
90        DEBUG(dbgs().write_hex(I->Upper) << "\n");
91        return false;
92      }
93      Prev = I->Upper;
94    }
95
96    return true;
97  }
98
99  const CharRanges Ranges;
100};
101
102#undef DEBUG_TYPE // "unicode"
103
104} // namespace sys
105} // namespace llvm
106
107
108#endif // LLVM_SUPPORT_UNICODECHARRANGES_H
109