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| 1 // Copyright 2011 the V8 project authors. All rights reserved. | |
| 2 // Redistribution and use in source and binary forms, with or without | |
| 3 // modification, are permitted provided that the following conditions are | |
| 4 // met: | |
| 5 // | |
| 6 // * Redistributions of source code must retain the above copyright | |
| 7 // notice, this list of conditions and the following disclaimer. | |
| 8 // * Redistributions in binary form must reproduce the above | |
| 9 // copyright notice, this list of conditions and the following | |
| 10 // disclaimer in the documentation and/or other materials provided | |
| 11 // with the distribution. | |
| 12 // * Neither the name of Google Inc. nor the names of its | |
| 13 // contributors may be used to endorse or promote products derived | |
| 14 // from this software without specific prior written permission. | |
| 15 // | |
| 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
| 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
| 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
| 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 27 | |
| 28 #include "v8.h" | |
| 29 | |
| 30 #include "ast.h" | |
| 31 #include "handles.h" | |
| 32 #include "scanner.h" | |
| 33 #include "unicode-inl.h" | |
| 34 | |
| 35 namespace v8 { | |
| 36 namespace internal { | |
| 37 | |
| 38 // ---------------------------------------------------------------------------- | |
| 39 // BufferedUC16CharacterStreams | |
| 40 | |
| 41 BufferedUC16CharacterStream::BufferedUC16CharacterStream() | |
| 42 : UC16CharacterStream(), | |
| 43 pushback_limit_(NULL) { | |
| 44 // Initialize buffer as being empty. First read will fill the buffer. | |
| 45 buffer_cursor_ = buffer_; | |
| 46 buffer_end_ = buffer_; | |
| 47 } | |
| 48 | |
| 49 BufferedUC16CharacterStream::~BufferedUC16CharacterStream() { } | |
| 50 | |
| 51 void BufferedUC16CharacterStream::PushBack(uc32 character) { | |
| 52 if (character == kEndOfInput) { | |
| 53 pos_--; | |
| 54 return; | |
| 55 } | |
| 56 if (pushback_limit_ == NULL && buffer_cursor_ > buffer_) { | |
| 57 // buffer_ is writable, buffer_cursor_ is const pointer. | |
| 58 buffer_[--buffer_cursor_ - buffer_] = static_cast<uc16>(character); | |
| 59 pos_--; | |
| 60 return; | |
| 61 } | |
| 62 SlowPushBack(static_cast<uc16>(character)); | |
| 63 } | |
| 64 | |
| 65 | |
| 66 void BufferedUC16CharacterStream::SlowPushBack(uc16 character) { | |
| 67 // In pushback mode, the end of the buffer contains pushback, | |
| 68 // and the start of the buffer (from buffer start to pushback_limit_) | |
| 69 // contains valid data that comes just after the pushback. | |
| 70 // We NULL the pushback_limit_ if pushing all the way back to the | |
| 71 // start of the buffer. | |
| 72 | |
| 73 if (pushback_limit_ == NULL) { | |
| 74 // Enter pushback mode. | |
| 75 pushback_limit_ = buffer_end_; | |
| 76 buffer_end_ = buffer_ + kBufferSize; | |
| 77 buffer_cursor_ = buffer_end_; | |
| 78 } | |
| 79 // Ensure that there is room for at least one pushback. | |
| 80 ASSERT(buffer_cursor_ > buffer_); | |
| 81 ASSERT(pos_ > 0); | |
| 82 buffer_[--buffer_cursor_ - buffer_] = character; | |
| 83 if (buffer_cursor_ == buffer_) { | |
| 84 pushback_limit_ = NULL; | |
| 85 } else if (buffer_cursor_ < pushback_limit_) { | |
| 86 pushback_limit_ = buffer_cursor_; | |
| 87 } | |
| 88 pos_--; | |
| 89 } | |
| 90 | |
| 91 | |
| 92 bool BufferedUC16CharacterStream::ReadBlock() { | |
| 93 buffer_cursor_ = buffer_; | |
| 94 if (pushback_limit_ != NULL) { | |
| 95 // Leave pushback mode. | |
| 96 buffer_end_ = pushback_limit_; | |
| 97 pushback_limit_ = NULL; | |
| 98 // If there were any valid characters left at the | |
| 99 // start of the buffer, use those. | |
| 100 if (buffer_cursor_ < buffer_end_) return true; | |
| 101 // Otherwise read a new block. | |
| 102 } | |
| 103 unsigned length = FillBuffer(pos_, kBufferSize); | |
| 104 buffer_end_ = buffer_ + length; | |
| 105 return length > 0; | |
| 106 } | |
| 107 | |
| 108 | |
| 109 unsigned BufferedUC16CharacterStream::SlowSeekForward(unsigned delta) { | |
| 110 // Leave pushback mode (i.e., ignore that there might be valid data | |
| 111 // in the buffer before the pushback_limit_ point). | |
| 112 pushback_limit_ = NULL; | |
| 113 return BufferSeekForward(delta); | |
| 114 } | |
| 115 | |
| 116 // ---------------------------------------------------------------------------- | |
| 117 // GenericStringUC16CharacterStream | |
| 118 | |
| 119 | |
| 120 GenericStringUC16CharacterStream::GenericStringUC16CharacterStream( | |
| 121 Handle<String> data, | |
| 122 unsigned start_position, | |
| 123 unsigned end_position) | |
| 124 : string_(data), | |
| 125 length_(end_position) { | |
| 126 ASSERT(end_position >= start_position); | |
| 127 buffer_cursor_ = buffer_; | |
| 128 buffer_end_ = buffer_; | |
| 129 pos_ = start_position; | |
| 130 } | |
| 131 | |
| 132 | |
| 133 GenericStringUC16CharacterStream::~GenericStringUC16CharacterStream() { } | |
| 134 | |
| 135 | |
| 136 unsigned GenericStringUC16CharacterStream::BufferSeekForward(unsigned delta) { | |
| 137 unsigned old_pos = pos_; | |
| 138 pos_ = Min(pos_ + delta, length_); | |
| 139 ReadBlock(); | |
| 140 return pos_ - old_pos; | |
| 141 } | |
| 142 | |
| 143 | |
| 144 unsigned GenericStringUC16CharacterStream::FillBuffer(unsigned from_pos, | |
| 145 unsigned length) { | |
| 146 if (from_pos >= length_) return 0; | |
| 147 if (from_pos + length > length_) { | |
| 148 length = length_ - from_pos; | |
| 149 } | |
| 150 String::WriteToFlat<uc16>(*string_, buffer_, from_pos, from_pos + length); | |
| 151 return length; | |
| 152 } | |
| 153 | |
| 154 | |
| 155 // ---------------------------------------------------------------------------- | |
| 156 // Utf8ToUC16CharacterStream | |
| 157 Utf8ToUC16CharacterStream::Utf8ToUC16CharacterStream(const byte* data, | |
| 158 unsigned length) | |
| 159 : BufferedUC16CharacterStream(), | |
| 160 raw_data_(data), | |
| 161 raw_data_length_(length), | |
| 162 raw_data_pos_(0), | |
| 163 raw_character_position_(0) { | |
| 164 ReadBlock(); | |
| 165 } | |
| 166 | |
| 167 | |
| 168 Utf8ToUC16CharacterStream::~Utf8ToUC16CharacterStream() { } | |
| 169 | |
| 170 | |
| 171 unsigned Utf8ToUC16CharacterStream::BufferSeekForward(unsigned delta) { | |
| 172 unsigned old_pos = pos_; | |
| 173 unsigned target_pos = pos_ + delta; | |
| 174 SetRawPosition(target_pos); | |
| 175 pos_ = raw_character_position_; | |
| 176 ReadBlock(); | |
| 177 return pos_ - old_pos; | |
| 178 } | |
| 179 | |
| 180 | |
| 181 unsigned Utf8ToUC16CharacterStream::FillBuffer(unsigned char_position, | |
| 182 unsigned length) { | |
| 183 static const unibrow::uchar kMaxUC16Character = 0xffff; | |
| 184 SetRawPosition(char_position); | |
| 185 if (raw_character_position_ != char_position) { | |
| 186 // char_position was not a valid position in the stream (hit the end | |
| 187 // while spooling to it). | |
| 188 return 0u; | |
| 189 } | |
| 190 unsigned i = 0; | |
| 191 while (i < length) { | |
| 192 if (raw_data_pos_ == raw_data_length_) break; | |
| 193 unibrow::uchar c = raw_data_[raw_data_pos_]; | |
| 194 if (c <= unibrow::Utf8::kMaxOneByteChar) { | |
| 195 raw_data_pos_++; | |
| 196 } else { | |
| 197 c = unibrow::Utf8::CalculateValue(raw_data_ + raw_data_pos_, | |
| 198 raw_data_length_ - raw_data_pos_, | |
| 199 &raw_data_pos_); | |
| 200 // Don't allow characters outside of the BMP. | |
| 201 if (c > kMaxUC16Character) { | |
| 202 c = unibrow::Utf8::kBadChar; | |
| 203 } | |
| 204 } | |
| 205 buffer_[i++] = static_cast<uc16>(c); | |
| 206 } | |
| 207 raw_character_position_ = char_position + i; | |
| 208 return i; | |
| 209 } | |
| 210 | |
| 211 | |
| 212 static const byte kUtf8MultiByteMask = 0xC0; | |
| 213 static const byte kUtf8MultiByteCharStart = 0xC0; | |
| 214 static const byte kUtf8MultiByteCharFollower = 0x80; | |
| 215 | |
| 216 | |
| 217 #ifdef DEBUG | |
| 218 static bool IsUtf8MultiCharacterStart(byte first_byte) { | |
| 219 return (first_byte & kUtf8MultiByteMask) == kUtf8MultiByteCharStart; | |
| 220 } | |
| 221 #endif | |
| 222 | |
| 223 | |
| 224 static bool IsUtf8MultiCharacterFollower(byte later_byte) { | |
| 225 return (later_byte & kUtf8MultiByteMask) == kUtf8MultiByteCharFollower; | |
| 226 } | |
| 227 | |
| 228 | |
| 229 // Move the cursor back to point at the preceding UTF-8 character start | |
| 230 // in the buffer. | |
| 231 static inline void Utf8CharacterBack(const byte* buffer, unsigned* cursor) { | |
| 232 byte character = buffer[--*cursor]; | |
| 233 if (character > unibrow::Utf8::kMaxOneByteChar) { | |
| 234 ASSERT(IsUtf8MultiCharacterFollower(character)); | |
| 235 // Last byte of a multi-byte character encoding. Step backwards until | |
| 236 // pointing to the first byte of the encoding, recognized by having the | |
| 237 // top two bits set. | |
| 238 while (IsUtf8MultiCharacterFollower(buffer[--*cursor])) { } | |
| 239 ASSERT(IsUtf8MultiCharacterStart(buffer[*cursor])); | |
| 240 } | |
| 241 } | |
| 242 | |
| 243 | |
| 244 // Move the cursor forward to point at the next following UTF-8 character start | |
| 245 // in the buffer. | |
| 246 static inline void Utf8CharacterForward(const byte* buffer, unsigned* cursor) { | |
| 247 byte character = buffer[(*cursor)++]; | |
| 248 if (character > unibrow::Utf8::kMaxOneByteChar) { | |
| 249 // First character of a multi-byte character encoding. | |
| 250 // The number of most-significant one-bits determines the length of the | |
| 251 // encoding: | |
| 252 // 110..... - (0xCx, 0xDx) one additional byte (minimum). | |
| 253 // 1110.... - (0xEx) two additional bytes. | |
| 254 // 11110... - (0xFx) three additional bytes (maximum). | |
| 255 ASSERT(IsUtf8MultiCharacterStart(character)); | |
| 256 // Additional bytes is: | |
| 257 // 1 if value in range 0xC0 .. 0xDF. | |
| 258 // 2 if value in range 0xE0 .. 0xEF. | |
| 259 // 3 if value in range 0xF0 .. 0xF7. | |
| 260 // Encode that in a single value. | |
| 261 unsigned additional_bytes = | |
| 262 ((0x3211u) >> (((character - 0xC0) >> 2) & 0xC)) & 0x03; | |
| 263 *cursor += additional_bytes; | |
| 264 ASSERT(!IsUtf8MultiCharacterFollower(buffer[1 + additional_bytes])); | |
| 265 } | |
| 266 } | |
| 267 | |
| 268 | |
| 269 void Utf8ToUC16CharacterStream::SetRawPosition(unsigned target_position) { | |
| 270 if (raw_character_position_ > target_position) { | |
| 271 // Spool backwards in utf8 buffer. | |
| 272 do { | |
| 273 Utf8CharacterBack(raw_data_, &raw_data_pos_); | |
| 274 raw_character_position_--; | |
| 275 } while (raw_character_position_ > target_position); | |
| 276 return; | |
| 277 } | |
| 278 // Spool forwards in the utf8 buffer. | |
| 279 while (raw_character_position_ < target_position) { | |
| 280 if (raw_data_pos_ == raw_data_length_) return; | |
| 281 Utf8CharacterForward(raw_data_, &raw_data_pos_); | |
| 282 raw_character_position_++; | |
| 283 } | |
| 284 } | |
| 285 | |
| 286 | |
| 287 // ---------------------------------------------------------------------------- | |
| 288 // ExternalTwoByteStringUC16CharacterStream | |
| 289 | |
| 290 ExternalTwoByteStringUC16CharacterStream:: | |
| 291 ~ExternalTwoByteStringUC16CharacterStream() { } | |
| 292 | |
| 293 | |
| 294 ExternalTwoByteStringUC16CharacterStream | |
| 295 ::ExternalTwoByteStringUC16CharacterStream( | |
| 296 Handle<ExternalTwoByteString> data, | |
| 297 int start_position, | |
| 298 int end_position) | |
| 299 : UC16CharacterStream(), | |
| 300 source_(data), | |
| 301 raw_data_(data->GetTwoByteData(start_position)) { | |
| 302 buffer_cursor_ = raw_data_, | |
| 303 buffer_end_ = raw_data_ + (end_position - start_position); | |
| 304 pos_ = start_position; | |
| 305 } | |
| 306 | |
| 307 | |
| 308 // ---------------------------------------------------------------------------- | |
| 309 // Scanner::LiteralScope | |
| 310 | |
| 311 Scanner::LiteralScope::LiteralScope(Scanner* self) | |
| 312 : scanner_(self), complete_(false) { | |
| 313 self->StartLiteral(); | |
| 314 } | |
| 315 | |
| 316 | |
| 317 Scanner::LiteralScope::~LiteralScope() { | |
| 318 if (!complete_) scanner_->DropLiteral(); | |
| 319 } | |
| 320 | |
| 321 | |
| 322 void Scanner::LiteralScope::Complete() { | |
| 323 scanner_->TerminateLiteral(); | |
| 324 complete_ = true; | |
| 325 } | |
| 326 | |
| 327 } } // namespace v8::internal | |
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Chromium Code Reviews
Issue 7739020:
Rename scanner.* to scanner-character-streams.* and scanner-base.* to scanner.* (Closed)
Base URL: git://github.com/v8/v8.git@master