1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_UNICODE_H_ 6 #define V8_UNICODE_H_ 7 8 #include <sys/types.h> 9 #include "src/globals.h" 10 #include "src/utils.h" 11 /** 12 * \file 13 * Definitions and convenience functions for working with unicode. 14 */ 15 16 namespace unibrow { 17 18 typedef unsigned int uchar; 19 typedef unsigned char byte; 20 21 /** 22 * The max length of the result of converting the case of a single 23 * character. 24 */ 25 const int kMaxMappingSize = 4; 26 27 template <class T, int size = 256> 28 class Predicate { 29 public: Predicate()30 inline Predicate() { } 31 inline bool get(uchar c); 32 33 private: 34 friend class Test; 35 bool CalculateValue(uchar c); 36 class CacheEntry { 37 public: CacheEntry()38 inline CacheEntry() 39 : bit_field_(CodePointField::encode(0) | ValueField::encode(0)) {} CacheEntry(uchar code_point,bool value)40 inline CacheEntry(uchar code_point, bool value) 41 : bit_field_(CodePointField::encode(code_point) | 42 ValueField::encode(value)) {} 43 code_point()44 uchar code_point() const { return CodePointField::decode(bit_field_); } value()45 bool value() const { return ValueField::decode(bit_field_); } 46 47 private: 48 class CodePointField : public v8::internal::BitField<uchar, 0, 21> {}; 49 class ValueField : public v8::internal::BitField<bool, 21, 1> {}; 50 51 uint32_t bit_field_; 52 }; 53 static const int kSize = size; 54 static const int kMask = kSize - 1; 55 CacheEntry entries_[kSize]; 56 }; 57 58 59 // A cache used in case conversion. It caches the value for characters 60 // that either have no mapping or map to a single character independent 61 // of context. Characters that map to more than one character or that 62 // map differently depending on context are always looked up. 63 template <class T, int size = 256> 64 class Mapping { 65 public: Mapping()66 inline Mapping() { } 67 inline int get(uchar c, uchar n, uchar* result); 68 private: 69 friend class Test; 70 int CalculateValue(uchar c, uchar n, uchar* result); 71 struct CacheEntry { CacheEntryCacheEntry72 inline CacheEntry() : code_point_(kNoChar), offset_(0) { } CacheEntryCacheEntry73 inline CacheEntry(uchar code_point, signed offset) 74 : code_point_(code_point), 75 offset_(offset) { } 76 uchar code_point_; 77 signed offset_; 78 static const int kNoChar = (1 << 21) - 1; 79 }; 80 static const int kSize = size; 81 static const int kMask = kSize - 1; 82 CacheEntry entries_[kSize]; 83 }; 84 85 86 class UnicodeData { 87 private: 88 friend class Test; 89 static int GetByteCount(); 90 static const uchar kMaxCodePoint; 91 }; 92 93 94 class Utf16 { 95 public: IsSurrogatePair(int lead,int trail)96 static inline bool IsSurrogatePair(int lead, int trail) { 97 return IsLeadSurrogate(lead) && IsTrailSurrogate(trail); 98 } IsLeadSurrogate(int code)99 static inline bool IsLeadSurrogate(int code) { 100 if (code == kNoPreviousCharacter) return false; 101 return (code & 0xfc00) == 0xd800; 102 } IsTrailSurrogate(int code)103 static inline bool IsTrailSurrogate(int code) { 104 if (code == kNoPreviousCharacter) return false; 105 return (code & 0xfc00) == 0xdc00; 106 } 107 CombineSurrogatePair(uchar lead,uchar trail)108 static inline int CombineSurrogatePair(uchar lead, uchar trail) { 109 return 0x10000 + ((lead & 0x3ff) << 10) + (trail & 0x3ff); 110 } 111 static const int kNoPreviousCharacter = -1; 112 static const uchar kMaxNonSurrogateCharCode = 0xffff; 113 // Encoding a single UTF-16 code unit will produce 1, 2 or 3 bytes 114 // of UTF-8 data. The special case where the unit is a surrogate 115 // trail produces 1 byte net, because the encoding of the pair is 116 // 4 bytes and the 3 bytes that were used to encode the lead surrogate 117 // can be reclaimed. 118 static const int kMaxExtraUtf8BytesForOneUtf16CodeUnit = 3; 119 // One UTF-16 surrogate is endoded (illegally) as 3 UTF-8 bytes. 120 // The illegality stems from the surrogate not being part of a pair. 121 static const int kUtf8BytesToCodeASurrogate = 3; LeadSurrogate(uint32_t char_code)122 static inline uint16_t LeadSurrogate(uint32_t char_code) { 123 return 0xd800 + (((char_code - 0x10000) >> 10) & 0x3ff); 124 } TrailSurrogate(uint32_t char_code)125 static inline uint16_t TrailSurrogate(uint32_t char_code) { 126 return 0xdc00 + (char_code & 0x3ff); 127 } 128 }; 129 130 131 class Utf8 { 132 public: 133 static inline uchar Length(uchar chr, int previous); 134 static inline unsigned EncodeOneByte(char* out, uint8_t c); 135 static inline unsigned Encode(char* out, 136 uchar c, 137 int previous, 138 bool replace_invalid = false); 139 static uchar CalculateValue(const byte* str, size_t length, size_t* cursor); 140 141 // The unicode replacement character, used to signal invalid unicode 142 // sequences (e.g. an orphan surrogate) when converting to a UTF-8 encoding. 143 static const uchar kBadChar = 0xFFFD; 144 static const unsigned kMaxEncodedSize = 4; 145 static const unsigned kMaxOneByteChar = 0x7f; 146 static const unsigned kMaxTwoByteChar = 0x7ff; 147 static const unsigned kMaxThreeByteChar = 0xffff; 148 static const unsigned kMaxFourByteChar = 0x1fffff; 149 150 // A single surrogate is coded as a 3 byte UTF-8 sequence, but two together 151 // that match are coded as a 4 byte UTF-8 sequence. 152 static const unsigned kBytesSavedByCombiningSurrogates = 2; 153 static const unsigned kSizeOfUnmatchedSurrogate = 3; 154 // The maximum size a single UTF-16 code unit may take up when encoded as 155 // UTF-8. 156 static const unsigned kMax16BitCodeUnitSize = 3; 157 static inline uchar ValueOf(const byte* str, size_t length, size_t* cursor); 158 }; 159 160 struct Uppercase { 161 static bool Is(uchar c); 162 }; 163 struct Lowercase { 164 static bool Is(uchar c); 165 }; 166 struct Letter { 167 static bool Is(uchar c); 168 }; 169 struct ID_Start { 170 static bool Is(uchar c); 171 }; 172 struct ID_Continue { 173 static bool Is(uchar c); 174 }; 175 struct WhiteSpace { 176 static bool Is(uchar c); 177 }; 178 struct LineTerminator { 179 static bool Is(uchar c); 180 }; 181 struct ToLowercase { 182 static const int kMaxWidth = 3; 183 static const bool kIsToLower = true; 184 static int Convert(uchar c, 185 uchar n, 186 uchar* result, 187 bool* allow_caching_ptr); 188 }; 189 struct ToUppercase { 190 static const int kMaxWidth = 3; 191 static const bool kIsToLower = false; 192 static int Convert(uchar c, 193 uchar n, 194 uchar* result, 195 bool* allow_caching_ptr); 196 }; 197 struct Ecma262Canonicalize { 198 static const int kMaxWidth = 1; 199 static int Convert(uchar c, 200 uchar n, 201 uchar* result, 202 bool* allow_caching_ptr); 203 }; 204 struct Ecma262UnCanonicalize { 205 static const int kMaxWidth = 4; 206 static int Convert(uchar c, 207 uchar n, 208 uchar* result, 209 bool* allow_caching_ptr); 210 }; 211 struct CanonicalizationRange { 212 static const int kMaxWidth = 1; 213 static int Convert(uchar c, 214 uchar n, 215 uchar* result, 216 bool* allow_caching_ptr); 217 }; 218 219 } // namespace unibrow 220 221 #endif // V8_UNICODE_H_ 222