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14 | pmbaty | 1 | //===--- UnicodeCharRanges.h - Types and functions for character ranges ---===// |
2 | // |
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3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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4 | // See https://llvm.org/LICENSE.txt for license information. |
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5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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6 | // |
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7 | //===----------------------------------------------------------------------===// |
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8 | #ifndef LLVM_SUPPORT_UNICODECHARRANGES_H |
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9 | #define LLVM_SUPPORT_UNICODECHARRANGES_H |
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10 | |||
11 | #include "llvm/ADT/ArrayRef.h" |
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12 | #include "llvm/Support/Compiler.h" |
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13 | #include "llvm/Support/Debug.h" |
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14 | #include "llvm/Support/raw_ostream.h" |
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15 | #include <algorithm> |
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16 | |||
17 | #define DEBUG_TYPE "unicode" |
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18 | |||
19 | namespace llvm { |
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20 | namespace sys { |
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21 | |||
22 | /// Represents a closed range of Unicode code points [Lower, Upper]. |
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23 | struct UnicodeCharRange { |
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24 | uint32_t Lower; |
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25 | uint32_t Upper; |
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26 | }; |
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27 | |||
28 | inline bool operator<(uint32_t Value, UnicodeCharRange Range) { |
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29 | return Value < Range.Lower; |
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30 | } |
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31 | inline bool operator<(UnicodeCharRange Range, uint32_t Value) { |
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32 | return Range.Upper < Value; |
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33 | } |
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34 | |||
35 | /// Holds a reference to an ordered array of UnicodeCharRange and allows |
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36 | /// to quickly check if a code point is contained in the set represented by this |
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37 | /// array. |
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38 | class UnicodeCharSet { |
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39 | public: |
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40 | typedef ArrayRef<UnicodeCharRange> CharRanges; |
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41 | |||
42 | /// Constructs a UnicodeCharSet instance from an array of |
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43 | /// UnicodeCharRanges. |
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44 | /// |
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45 | /// Array pointed by \p Ranges should have the lifetime at least as long as |
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46 | /// the UnicodeCharSet instance, and should not change. Array is validated by |
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47 | /// the constructor, so it makes sense to create as few UnicodeCharSet |
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48 | /// instances per each array of ranges, as possible. |
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49 | #ifdef NDEBUG |
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50 | |||
51 | // FIXME: This could use constexpr + static_assert. This way we |
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52 | // may get rid of NDEBUG in this header. Unfortunately there are some |
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53 | // problems to get this working with MSVC 2013. Change this when |
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54 | // the support for MSVC 2013 is dropped. |
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55 | constexpr UnicodeCharSet(CharRanges Ranges) : Ranges(Ranges) {} |
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56 | #else |
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57 | UnicodeCharSet(CharRanges Ranges) : Ranges(Ranges) { |
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58 | assert(rangesAreValid()); |
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59 | } |
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60 | #endif |
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61 | |||
62 | /// Returns true if the character set contains the Unicode code point |
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63 | /// \p C. |
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64 | bool contains(uint32_t C) const { |
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65 | return std::binary_search(Ranges.begin(), Ranges.end(), C); |
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66 | } |
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67 | |||
68 | private: |
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69 | /// Returns true if each of the ranges is a proper closed range |
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70 | /// [min, max], and if the ranges themselves are ordered and non-overlapping. |
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71 | bool rangesAreValid() const { |
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72 | uint32_t Prev = 0; |
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73 | for (CharRanges::const_iterator I = Ranges.begin(), E = Ranges.end(); |
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74 | I != E; ++I) { |
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75 | if (I != Ranges.begin() && Prev >= I->Lower) { |
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76 | LLVM_DEBUG(dbgs() << "Upper bound 0x"); |
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77 | LLVM_DEBUG(dbgs().write_hex(Prev)); |
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78 | LLVM_DEBUG(dbgs() << " should be less than succeeding lower bound 0x"); |
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79 | LLVM_DEBUG(dbgs().write_hex(I->Lower) << "\n"); |
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80 | return false; |
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81 | } |
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82 | if (I->Upper < I->Lower) { |
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83 | LLVM_DEBUG(dbgs() << "Upper bound 0x"); |
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84 | LLVM_DEBUG(dbgs().write_hex(I->Lower)); |
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85 | LLVM_DEBUG(dbgs() << " should not be less than lower bound 0x"); |
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86 | LLVM_DEBUG(dbgs().write_hex(I->Upper) << "\n"); |
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87 | return false; |
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88 | } |
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89 | Prev = I->Upper; |
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90 | } |
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91 | |||
92 | return true; |
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93 | } |
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94 | |||
95 | const CharRanges Ranges; |
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96 | }; |
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97 | |||
98 | } // namespace sys |
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99 | } // namespace llvm |
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100 | |||
101 | #undef DEBUG_TYPE // "unicode" |
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102 | |||
103 | #endif // LLVM_SUPPORT_UNICODECHARRANGES_H |