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