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       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             : 
      21             : #define DEBUG_TYPE "unicode"
      22             : 
      23             : namespace llvm {
      24             : namespace sys {
      25             : 
      26             : /// Represents a closed range of Unicode code points [Lower, Upper].
      27             : struct UnicodeCharRange {
      28             :   uint32_t Lower;
      29             :   uint32_t Upper;
      30             : };
      31             : 
      32           0 : inline bool operator<(uint32_t Value, UnicodeCharRange Range) {
      33           0 :   return Value < Range.Lower;
      34             : }
      35           0 : inline bool operator<(UnicodeCharRange Range, uint32_t Value) {
      36           0 :   return Range.Upper < Value;
      37             : }
      38             : 
      39             : /// 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.
      42             : class UnicodeCharSet {
      43             : public:
      44             :   typedef ArrayRef<UnicodeCharRange> CharRanges;
      45             : 
      46             :   /// 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             :   /// Returns true if the character set contains the Unicode code point
      67             :   /// \p C.
      68             :   bool contains(uint32_t C) const {
      69    63085518 :     return std::binary_search(Ranges.begin(), Ranges.end(), C);
      70             :   }
      71             : 
      72             : private:
      73             :   /// 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             :         LLVM_DEBUG(dbgs() << "Upper bound 0x");
      81             :         LLVM_DEBUG(dbgs().write_hex(Prev));
      82             :         LLVM_DEBUG(dbgs() << " should be less than succeeding lower bound 0x");
      83             :         LLVM_DEBUG(dbgs().write_hex(I->Lower) << "\n");
      84             :         return false;
      85             :       }
      86             :       if (I->Upper < I->Lower) {
      87             :         LLVM_DEBUG(dbgs() << "Upper bound 0x");
      88             :         LLVM_DEBUG(dbgs().write_hex(I->Lower));
      89             :         LLVM_DEBUG(dbgs() << " should not be less than lower bound 0x");
      90             :         LLVM_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             : } // namespace sys
     103             : } // namespace llvm
     104             : 
     105             : #undef DEBUG_TYPE // "unicode"
     106             : 
     107             : #endif // LLVM_SUPPORT_UNICODECHARRANGES_H