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. UnicodeCharSet(CharRanges Ranges)55 constexpr UnicodeCharSet(CharRanges Ranges) : Ranges(Ranges) {} 56 #else UnicodeCharSet(CharRanges Ranges)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. contains(uint32_t C)64 bool contains(uint32_t C) const { 65 return std::binary_search(Ranges.begin(), Ranges.end(), 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. rangesAreValid()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