// Copyright 2011 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef V8_STRINGS_UNICODE_H_ #define V8_STRINGS_UNICODE_H_ #include <sys/types.h> #include "src/base/bit-field.h" #include "src/common/globals.h" #include "src/third_party/utf8-decoder/utf8-decoder.h" /** * \file * Definitions and convenience functions for working with unicode. */ namespace unibrow { using uchar = unsigned int; using byte = unsigned char; /** * The max length of the result of converting the case of a single * character. */ const int kMaxMappingSize = 4; #ifndef V8_INTL_SUPPORT template <class T, int size = 256> class Predicate { public: inline Predicate() = default; inline bool get(uchar c); private: friend class Test; bool CalculateValue(uchar c); class CacheEntry { public: inline CacheEntry() : bit_field_(CodePointField::encode(0) | ValueField::encode(0)) {} inline CacheEntry(uchar code_point, bool value) : bit_field_( CodePointField::encode(CodePointField::kMask & code_point) | ValueField::encode(value)) { DCHECK_IMPLIES((CodePointField::kMask & code_point) != code_point, code_point == static_cast<uchar>(-1)); } uchar code_point() const { return CodePointField::decode(bit_field_); } bool value() const { return ValueField::decode(bit_field_); } private: using CodePointField = v8::base::BitField<uchar, 0, 21>; using ValueField = v8::base::BitField<bool, 21, 1>; uint32_t bit_field_; }; static const int kSize = size; static const int kMask = kSize - 1; CacheEntry entries_[kSize]; }; // A cache used in case conversion. It caches the value for characters // that either have no mapping or map to a single character independent // of context. Characters that map to more than one character or that // map differently depending on context are always looked up. template <class T, int size = 256> class Mapping { public: inline Mapping() = default; inline int get(uchar c, uchar n, uchar* result); private: friend class Test; int CalculateValue(uchar c, uchar n, uchar* result); struct CacheEntry { inline CacheEntry() : code_point_(kNoChar), offset_(0) {} inline CacheEntry(uchar code_point, signed offset) : code_point_(code_point), offset_(offset) {} uchar code_point_; signed offset_; static const int kNoChar = (1 << 21) - 1; }; static const int kSize = size; static const int kMask = kSize - 1; CacheEntry entries_[kSize]; }; class UnicodeData { private: friend class Test; static int GetByteCount(); static const uchar kMaxCodePoint; }; #endif // !V8_INTL_SUPPORT class Utf16 { public: static const int kNoPreviousCharacter = -1; static inline bool IsSurrogatePair(int lead, int trail) { return IsLeadSurrogate(lead) && IsTrailSurrogate(trail); } static inline bool IsLeadSurrogate(int code) { return (code & 0xfc00) == 0xd800; } static inline bool IsTrailSurrogate(int code) { return (code & 0xfc00) == 0xdc00; } static inline int CombineSurrogatePair(uchar lead, uchar trail) { return 0x10000 + ((lead & 0x3ff) << 10) + (trail & 0x3ff); } static const uchar kMaxNonSurrogateCharCode = 0xffff; // Encoding a single UTF-16 code unit will produce 1, 2 or 3 bytes // of UTF-8 data. The special case where the unit is a surrogate // trail produces 1 byte net, because the encoding of the pair is // 4 bytes and the 3 bytes that were used to encode the lead surrogate // can be reclaimed. static const int kMaxExtraUtf8BytesForOneUtf16CodeUnit = 3; // One UTF-16 surrogate is endoded (illegally) as 3 UTF-8 bytes. // The illegality stems from the surrogate not being part of a pair. static const int kUtf8BytesToCodeASurrogate = 3; static inline uint16_t LeadSurrogate(uint32_t char_code) { return 0xd800 + (((char_code - 0x10000) >> 10) & 0x3ff); } static inline uint16_t TrailSurrogate(uint32_t char_code) { return 0xdc00 + (char_code & 0x3ff); } }; class Latin1 { public: static const uint16_t kMaxChar = 0xff; // Convert the character to Latin-1 case equivalent if possible. static inline uint16_t TryConvertToLatin1(uint16_t c) { switch (c) { // This are equivalent characters in unicode. case 0x39c: case 0x3bc: return 0xb5; // This is an uppercase of a Latin-1 character // outside of Latin-1. case 0x178: return 0xff; } return c; } }; class V8_EXPORT_PRIVATE Utf8 { public: using State = Utf8DfaDecoder::State; static inline uchar Length(uchar chr, int previous); static inline unsigned EncodeOneByte(char* out, uint8_t c); static inline unsigned Encode(char* out, uchar c, int previous, bool replace_invalid = false); static uchar CalculateValue(const byte* str, size_t length, size_t* cursor); // The unicode replacement character, used to signal invalid unicode // sequences (e.g. an orphan surrogate) when converting to a UTF-8 encoding. static const uchar kBadChar = 0xFFFD; static const uchar kBufferEmpty = 0x0; static const uchar kIncomplete = 0xFFFFFFFC; // any non-valid code point. static const unsigned kMaxEncodedSize = 4; static const unsigned kMaxOneByteChar = 0x7f; static const unsigned kMaxTwoByteChar = 0x7ff; static const unsigned kMaxThreeByteChar = 0xffff; static const unsigned kMaxFourByteChar = 0x1fffff; // A single surrogate is coded as a 3 byte UTF-8 sequence, but two together // that match are coded as a 4 byte UTF-8 sequence. static const unsigned kBytesSavedByCombiningSurrogates = 2; static const unsigned kSizeOfUnmatchedSurrogate = 3; // The maximum size a single UTF-16 code unit may take up when encoded as // UTF-8. static const unsigned kMax16BitCodeUnitSize = 3; static inline uchar ValueOf(const byte* str, size_t length, size_t* cursor); using Utf8IncrementalBuffer = uint32_t; static inline uchar ValueOfIncremental(const byte** cursor, State* state, Utf8IncrementalBuffer* buffer); static uchar ValueOfIncrementalFinish(State* state); // Excludes non-characters from the set of valid code points. static inline bool IsValidCharacter(uchar c); // Validate if the input has a valid utf-8 encoding. Unlike JS source code // this validation function will accept any unicode code point, including // kBadChar and BOMs. // // This method checks for: // - valid utf-8 endcoding (e.g. no over-long encodings), // - absence of surrogates, // - valid code point range. static bool ValidateEncoding(const byte* str, size_t length); }; struct Uppercase { static bool Is(uchar c); }; struct Letter { static bool Is(uchar c); }; #ifndef V8_INTL_SUPPORT struct V8_EXPORT_PRIVATE ID_Start { static bool Is(uchar c); }; struct V8_EXPORT_PRIVATE ID_Continue { static bool Is(uchar c); }; struct V8_EXPORT_PRIVATE WhiteSpace { static bool Is(uchar c); }; #endif // !V8_INTL_SUPPORT // LineTerminator: 'JS_Line_Terminator' in point.properties // ES#sec-line-terminators lists exactly 4 code points: // LF (U+000A), CR (U+000D), LS(U+2028), PS(U+2029) V8_INLINE bool IsLineTerminator(uchar c) { return c == 0x000A || c == 0x000D || c == 0x2028 || c == 0x2029; } V8_INLINE bool IsStringLiteralLineTerminator(uchar c) { return c == 0x000A || c == 0x000D; } #ifndef V8_INTL_SUPPORT struct V8_EXPORT_PRIVATE ToLowercase { static const int kMaxWidth = 3; static const bool kIsToLower = true; static int Convert(uchar c, uchar n, uchar* result, bool* allow_caching_ptr); }; struct V8_EXPORT_PRIVATE ToUppercase { static const int kMaxWidth = 3; static const bool kIsToLower = false; static int Convert(uchar c, uchar n, uchar* result, bool* allow_caching_ptr); }; struct V8_EXPORT_PRIVATE Ecma262Canonicalize { static const int kMaxWidth = 1; static int Convert(uchar c, uchar n, uchar* result, bool* allow_caching_ptr); }; struct V8_EXPORT_PRIVATE Ecma262UnCanonicalize { static const int kMaxWidth = 4; static int Convert(uchar c, uchar n, uchar* result, bool* allow_caching_ptr); }; struct V8_EXPORT_PRIVATE CanonicalizationRange { static const int kMaxWidth = 1; static int Convert(uchar c, uchar n, uchar* result, bool* allow_caching_ptr); }; #endif // !V8_INTL_SUPPORT } // namespace unibrow #endif // V8_STRINGS_UNICODE_H_