Line data Source code
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/third_party/utf8-decoder/utf8-decoder.h"
11 : #include "src/utils.h"
12 : /**
13 : * \file
14 : * Definitions and convenience functions for working with unicode.
15 : */
16 :
17 : namespace unibrow {
18 :
19 : typedef unsigned int uchar;
20 : typedef unsigned char byte;
21 :
22 : /**
23 : * The max length of the result of converting the case of a single
24 : * character.
25 : */
26 : const int kMaxMappingSize = 4;
27 :
28 : #ifndef V8_INTL_SUPPORT
29 : template <class T, int size = 256>
30 : class Predicate {
31 : public:
32 : inline Predicate() = default;
33 : inline bool get(uchar c);
34 :
35 : private:
36 : friend class Test;
37 : bool CalculateValue(uchar c);
38 : class CacheEntry {
39 : public:
40 : inline CacheEntry()
41 : : bit_field_(CodePointField::encode(0) | ValueField::encode(0)) {}
42 : inline CacheEntry(uchar code_point, bool value)
43 : : bit_field_(
44 : CodePointField::encode(CodePointField::kMask & code_point) |
45 : ValueField::encode(value)) {
46 : DCHECK_IMPLIES((CodePointField::kMask & code_point) != code_point,
47 : code_point == static_cast<uchar>(-1));
48 : }
49 :
50 : uchar code_point() const { return CodePointField::decode(bit_field_); }
51 : bool value() const { return ValueField::decode(bit_field_); }
52 :
53 : private:
54 : class CodePointField : public v8::internal::BitField<uchar, 0, 21> {};
55 : class ValueField : public v8::internal::BitField<bool, 21, 1> {};
56 :
57 : uint32_t bit_field_;
58 : };
59 : static const int kSize = size;
60 : static const int kMask = kSize - 1;
61 : CacheEntry entries_[kSize];
62 : };
63 :
64 :
65 : // A cache used in case conversion. It caches the value for characters
66 : // that either have no mapping or map to a single character independent
67 : // of context. Characters that map to more than one character or that
68 : // map differently depending on context are always looked up.
69 : template <class T, int size = 256>
70 : class Mapping {
71 : public:
72 : inline Mapping() = default;
73 : inline int get(uchar c, uchar n, uchar* result);
74 : private:
75 : friend class Test;
76 : int CalculateValue(uchar c, uchar n, uchar* result);
77 : struct CacheEntry {
78 : inline CacheEntry() : code_point_(kNoChar), offset_(0) { }
79 : inline CacheEntry(uchar code_point, signed offset)
80 : : code_point_(code_point),
81 : offset_(offset) { }
82 : uchar code_point_;
83 : signed offset_;
84 : static const int kNoChar = (1 << 21) - 1;
85 : };
86 : static const int kSize = size;
87 : static const int kMask = kSize - 1;
88 : CacheEntry entries_[kSize];
89 : };
90 :
91 : class UnicodeData {
92 : private:
93 : friend class Test;
94 : static int GetByteCount();
95 : static const uchar kMaxCodePoint;
96 : };
97 :
98 : #endif // !V8_INTL_SUPPORT
99 :
100 : class Utf16 {
101 : public:
102 : static const int kNoPreviousCharacter = -1;
103 : static inline bool IsSurrogatePair(int lead, int trail) {
104 105542034 : return IsLeadSurrogate(lead) && IsTrailSurrogate(trail);
105 : }
106 : static inline bool IsLeadSurrogate(int code) {
107 96255679 : return (code & 0xfc00) == 0xd800;
108 : }
109 : static inline bool IsTrailSurrogate(int code) {
110 15064760 : return (code & 0xfc00) == 0xdc00;
111 : }
112 :
113 : static inline int CombineSurrogatePair(uchar lead, uchar trail) {
114 15075050 : return 0x10000 + ((lead & 0x3ff) << 10) + (trail & 0x3ff);
115 : }
116 : static const uchar kMaxNonSurrogateCharCode = 0xffff;
117 : // Encoding a single UTF-16 code unit will produce 1, 2 or 3 bytes
118 : // of UTF-8 data. The special case where the unit is a surrogate
119 : // trail produces 1 byte net, because the encoding of the pair is
120 : // 4 bytes and the 3 bytes that were used to encode the lead surrogate
121 : // can be reclaimed.
122 : static const int kMaxExtraUtf8BytesForOneUtf16CodeUnit = 3;
123 : // One UTF-16 surrogate is endoded (illegally) as 3 UTF-8 bytes.
124 : // The illegality stems from the surrogate not being part of a pair.
125 : static const int kUtf8BytesToCodeASurrogate = 3;
126 : static inline uint16_t LeadSurrogate(uint32_t char_code) {
127 3244313 : return 0xd800 + (((char_code - 0x10000) >> 10) & 0x3ff);
128 : }
129 : static inline uint16_t TrailSurrogate(uint32_t char_code) {
130 3244313 : return 0xdc00 + (char_code & 0x3ff);
131 : }
132 : };
133 :
134 : class V8_EXPORT_PRIVATE Utf8 {
135 : public:
136 : using State = Utf8DfaDecoder::State;
137 :
138 : static inline uchar Length(uchar chr, int previous);
139 : static inline unsigned EncodeOneByte(char* out, uint8_t c);
140 : static inline unsigned Encode(char* out,
141 : uchar c,
142 : int previous,
143 : bool replace_invalid = false);
144 : static uchar CalculateValue(const byte* str, size_t length, size_t* cursor);
145 :
146 : // The unicode replacement character, used to signal invalid unicode
147 : // sequences (e.g. an orphan surrogate) when converting to a UTF-8 encoding.
148 : static const uchar kBadChar = 0xFFFD;
149 : static const uchar kBufferEmpty = 0x0;
150 : static const uchar kIncomplete = 0xFFFFFFFC; // any non-valid code point.
151 : static const unsigned kMaxEncodedSize = 4;
152 : static const unsigned kMaxOneByteChar = 0x7f;
153 : static const unsigned kMaxTwoByteChar = 0x7ff;
154 : static const unsigned kMaxThreeByteChar = 0xffff;
155 : static const unsigned kMaxFourByteChar = 0x1fffff;
156 :
157 : // A single surrogate is coded as a 3 byte UTF-8 sequence, but two together
158 : // that match are coded as a 4 byte UTF-8 sequence.
159 : static const unsigned kBytesSavedByCombiningSurrogates = 2;
160 : static const unsigned kSizeOfUnmatchedSurrogate = 3;
161 : // The maximum size a single UTF-16 code unit may take up when encoded as
162 : // UTF-8.
163 : static const unsigned kMax16BitCodeUnitSize = 3;
164 : static inline uchar ValueOf(const byte* str, size_t length, size_t* cursor);
165 :
166 : typedef uint32_t Utf8IncrementalBuffer;
167 : static inline uchar ValueOfIncremental(const byte** cursor, State* state,
168 : Utf8IncrementalBuffer* buffer);
169 : static uchar ValueOfIncrementalFinish(State* state);
170 :
171 : // Excludes non-characters from the set of valid code points.
172 : static inline bool IsValidCharacter(uchar c);
173 :
174 : // Validate if the input has a valid utf-8 encoding. Unlike JS source code
175 : // this validation function will accept any unicode code point, including
176 : // kBadChar and BOMs.
177 : //
178 : // This method checks for:
179 : // - valid utf-8 endcoding (e.g. no over-long encodings),
180 : // - absence of surrogates,
181 : // - valid code point range.
182 : static bool ValidateEncoding(const byte* str, size_t length);
183 : };
184 :
185 : struct Uppercase {
186 : static bool Is(uchar c);
187 : };
188 : struct Letter {
189 : static bool Is(uchar c);
190 : };
191 : #ifndef V8_INTL_SUPPORT
192 : struct V8_EXPORT_PRIVATE ID_Start {
193 : static bool Is(uchar c);
194 : };
195 : struct V8_EXPORT_PRIVATE ID_Continue {
196 : static bool Is(uchar c);
197 : };
198 : struct V8_EXPORT_PRIVATE WhiteSpace {
199 : static bool Is(uchar c);
200 : };
201 : #endif // !V8_INTL_SUPPORT
202 :
203 : // LineTerminator: 'JS_Line_Terminator' in point.properties
204 : // ES#sec-line-terminators lists exactly 4 code points:
205 : // LF (U+000A), CR (U+000D), LS(U+2028), PS(U+2029)
206 : V8_INLINE bool IsLineTerminator(uchar c) {
207 749485623 : return c == 0x000A || c == 0x000D || c == 0x2028 || c == 0x2029;
208 : }
209 :
210 : V8_INLINE bool IsStringLiteralLineTerminator(uchar c) {
211 9153650 : return c == 0x000A || c == 0x000D;
212 : }
213 :
214 : #ifndef V8_INTL_SUPPORT
215 : struct ToLowercase {
216 : static const int kMaxWidth = 3;
217 : static const bool kIsToLower = true;
218 : static int Convert(uchar c,
219 : uchar n,
220 : uchar* result,
221 : bool* allow_caching_ptr);
222 : };
223 : struct ToUppercase {
224 : static const int kMaxWidth = 3;
225 : static const bool kIsToLower = false;
226 : static int Convert(uchar c,
227 : uchar n,
228 : uchar* result,
229 : bool* allow_caching_ptr);
230 : };
231 : struct V8_EXPORT_PRIVATE Ecma262Canonicalize {
232 : static const int kMaxWidth = 1;
233 : static int Convert(uchar c,
234 : uchar n,
235 : uchar* result,
236 : bool* allow_caching_ptr);
237 : };
238 : struct V8_EXPORT_PRIVATE Ecma262UnCanonicalize {
239 : static const int kMaxWidth = 4;
240 : static int Convert(uchar c,
241 : uchar n,
242 : uchar* result,
243 : bool* allow_caching_ptr);
244 : };
245 : struct V8_EXPORT_PRIVATE CanonicalizationRange {
246 : static const int kMaxWidth = 1;
247 : static int Convert(uchar c,
248 : uchar n,
249 : uchar* result,
250 : bool* allow_caching_ptr);
251 : };
252 : #endif // !V8_INTL_SUPPORT
253 :
254 : } // namespace unibrow
255 :
256 : #endif // V8_UNICODE_H_
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