Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame^] | 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 | // A simple interpreter for the Irregexp byte code. |
| 6 | |
| 7 | #include "src/regexp/interpreter-irregexp.h" |
| 8 | |
| 9 | #include "src/ast/ast.h" |
| 10 | #include "src/regexp/bytecodes-irregexp.h" |
| 11 | #include "src/regexp/jsregexp.h" |
| 12 | #include "src/regexp/regexp-macro-assembler.h" |
| 13 | #include "src/unicode.h" |
| 14 | #include "src/utils.h" |
| 15 | |
| 16 | namespace v8 { |
| 17 | namespace internal { |
| 18 | |
| 19 | |
| 20 | typedef unibrow::Mapping<unibrow::Ecma262Canonicalize> Canonicalize; |
| 21 | |
| 22 | static bool BackRefMatchesNoCase(Canonicalize* interp_canonicalize, |
| 23 | int from, |
| 24 | int current, |
| 25 | int len, |
| 26 | Vector<const uc16> subject) { |
| 27 | for (int i = 0; i < len; i++) { |
| 28 | unibrow::uchar old_char = subject[from++]; |
| 29 | unibrow::uchar new_char = subject[current++]; |
| 30 | if (old_char == new_char) continue; |
| 31 | unibrow::uchar old_string[1] = { old_char }; |
| 32 | unibrow::uchar new_string[1] = { new_char }; |
| 33 | interp_canonicalize->get(old_char, '\0', old_string); |
| 34 | interp_canonicalize->get(new_char, '\0', new_string); |
| 35 | if (old_string[0] != new_string[0]) { |
| 36 | return false; |
| 37 | } |
| 38 | } |
| 39 | return true; |
| 40 | } |
| 41 | |
| 42 | |
| 43 | static bool BackRefMatchesNoCase(Canonicalize* interp_canonicalize, |
| 44 | int from, |
| 45 | int current, |
| 46 | int len, |
| 47 | Vector<const uint8_t> subject) { |
| 48 | for (int i = 0; i < len; i++) { |
| 49 | unsigned int old_char = subject[from++]; |
| 50 | unsigned int new_char = subject[current++]; |
| 51 | if (old_char == new_char) continue; |
| 52 | // Convert both characters to lower case. |
| 53 | old_char |= 0x20; |
| 54 | new_char |= 0x20; |
| 55 | if (old_char != new_char) return false; |
| 56 | // Not letters in the ASCII range and Latin-1 range. |
| 57 | if (!(old_char - 'a' <= 'z' - 'a') && |
| 58 | !(old_char - 224 <= 254 - 224 && old_char != 247)) { |
| 59 | return false; |
| 60 | } |
| 61 | } |
| 62 | return true; |
| 63 | } |
| 64 | |
| 65 | |
| 66 | #ifdef DEBUG |
| 67 | static void TraceInterpreter(const byte* code_base, |
| 68 | const byte* pc, |
| 69 | int stack_depth, |
| 70 | int current_position, |
| 71 | uint32_t current_char, |
| 72 | int bytecode_length, |
| 73 | const char* bytecode_name) { |
| 74 | if (FLAG_trace_regexp_bytecodes) { |
| 75 | bool printable = (current_char < 127 && current_char >= 32); |
| 76 | const char* format = |
| 77 | printable ? |
| 78 | "pc = %02x, sp = %d, curpos = %d, curchar = %08x (%c), bc = %s" : |
| 79 | "pc = %02x, sp = %d, curpos = %d, curchar = %08x .%c., bc = %s"; |
| 80 | PrintF(format, |
| 81 | pc - code_base, |
| 82 | stack_depth, |
| 83 | current_position, |
| 84 | current_char, |
| 85 | printable ? current_char : '.', |
| 86 | bytecode_name); |
| 87 | for (int i = 0; i < bytecode_length; i++) { |
| 88 | printf(", %02x", pc[i]); |
| 89 | } |
| 90 | printf(" "); |
| 91 | for (int i = 1; i < bytecode_length; i++) { |
| 92 | unsigned char b = pc[i]; |
| 93 | if (b < 127 && b >= 32) { |
| 94 | printf("%c", b); |
| 95 | } else { |
| 96 | printf("."); |
| 97 | } |
| 98 | } |
| 99 | printf("\n"); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | |
| 104 | #define BYTECODE(name) \ |
| 105 | case BC_##name: \ |
| 106 | TraceInterpreter(code_base, \ |
| 107 | pc, \ |
| 108 | static_cast<int>(backtrack_sp - backtrack_stack_base), \ |
| 109 | current, \ |
| 110 | current_char, \ |
| 111 | BC_##name##_LENGTH, \ |
| 112 | #name); |
| 113 | #else |
| 114 | #define BYTECODE(name) \ |
| 115 | case BC_##name: |
| 116 | #endif |
| 117 | |
| 118 | |
| 119 | static int32_t Load32Aligned(const byte* pc) { |
| 120 | DCHECK((reinterpret_cast<intptr_t>(pc) & 3) == 0); |
| 121 | return *reinterpret_cast<const int32_t *>(pc); |
| 122 | } |
| 123 | |
| 124 | |
| 125 | static int32_t Load16Aligned(const byte* pc) { |
| 126 | DCHECK((reinterpret_cast<intptr_t>(pc) & 1) == 0); |
| 127 | return *reinterpret_cast<const uint16_t *>(pc); |
| 128 | } |
| 129 | |
| 130 | |
| 131 | // A simple abstraction over the backtracking stack used by the interpreter. |
| 132 | // This backtracking stack does not grow automatically, but it ensures that the |
| 133 | // the memory held by the stack is released or remembered in a cache if the |
| 134 | // matching terminates. |
| 135 | class BacktrackStack { |
| 136 | public: |
| 137 | BacktrackStack() { data_ = NewArray<int>(kBacktrackStackSize); } |
| 138 | |
| 139 | ~BacktrackStack() { |
| 140 | DeleteArray(data_); |
| 141 | } |
| 142 | |
| 143 | int* data() const { return data_; } |
| 144 | |
| 145 | int max_size() const { return kBacktrackStackSize; } |
| 146 | |
| 147 | private: |
| 148 | static const int kBacktrackStackSize = 10000; |
| 149 | |
| 150 | int* data_; |
| 151 | |
| 152 | DISALLOW_COPY_AND_ASSIGN(BacktrackStack); |
| 153 | }; |
| 154 | |
| 155 | |
| 156 | template <typename Char> |
| 157 | static RegExpImpl::IrregexpResult RawMatch(Isolate* isolate, |
| 158 | const byte* code_base, |
| 159 | Vector<const Char> subject, |
| 160 | int* registers, |
| 161 | int current, |
| 162 | uint32_t current_char) { |
| 163 | const byte* pc = code_base; |
| 164 | // BacktrackStack ensures that the memory allocated for the backtracking stack |
| 165 | // is returned to the system or cached if there is no stack being cached at |
| 166 | // the moment. |
| 167 | BacktrackStack backtrack_stack; |
| 168 | int* backtrack_stack_base = backtrack_stack.data(); |
| 169 | int* backtrack_sp = backtrack_stack_base; |
| 170 | int backtrack_stack_space = backtrack_stack.max_size(); |
| 171 | #ifdef DEBUG |
| 172 | if (FLAG_trace_regexp_bytecodes) { |
| 173 | PrintF("\n\nStart bytecode interpreter\n\n"); |
| 174 | } |
| 175 | #endif |
| 176 | while (true) { |
| 177 | int32_t insn = Load32Aligned(pc); |
| 178 | switch (insn & BYTECODE_MASK) { |
| 179 | BYTECODE(BREAK) |
| 180 | UNREACHABLE(); |
| 181 | return RegExpImpl::RE_FAILURE; |
| 182 | BYTECODE(PUSH_CP) |
| 183 | if (--backtrack_stack_space < 0) { |
| 184 | return RegExpImpl::RE_EXCEPTION; |
| 185 | } |
| 186 | *backtrack_sp++ = current; |
| 187 | pc += BC_PUSH_CP_LENGTH; |
| 188 | break; |
| 189 | BYTECODE(PUSH_BT) |
| 190 | if (--backtrack_stack_space < 0) { |
| 191 | return RegExpImpl::RE_EXCEPTION; |
| 192 | } |
| 193 | *backtrack_sp++ = Load32Aligned(pc + 4); |
| 194 | pc += BC_PUSH_BT_LENGTH; |
| 195 | break; |
| 196 | BYTECODE(PUSH_REGISTER) |
| 197 | if (--backtrack_stack_space < 0) { |
| 198 | return RegExpImpl::RE_EXCEPTION; |
| 199 | } |
| 200 | *backtrack_sp++ = registers[insn >> BYTECODE_SHIFT]; |
| 201 | pc += BC_PUSH_REGISTER_LENGTH; |
| 202 | break; |
| 203 | BYTECODE(SET_REGISTER) |
| 204 | registers[insn >> BYTECODE_SHIFT] = Load32Aligned(pc + 4); |
| 205 | pc += BC_SET_REGISTER_LENGTH; |
| 206 | break; |
| 207 | BYTECODE(ADVANCE_REGISTER) |
| 208 | registers[insn >> BYTECODE_SHIFT] += Load32Aligned(pc + 4); |
| 209 | pc += BC_ADVANCE_REGISTER_LENGTH; |
| 210 | break; |
| 211 | BYTECODE(SET_REGISTER_TO_CP) |
| 212 | registers[insn >> BYTECODE_SHIFT] = current + Load32Aligned(pc + 4); |
| 213 | pc += BC_SET_REGISTER_TO_CP_LENGTH; |
| 214 | break; |
| 215 | BYTECODE(SET_CP_TO_REGISTER) |
| 216 | current = registers[insn >> BYTECODE_SHIFT]; |
| 217 | pc += BC_SET_CP_TO_REGISTER_LENGTH; |
| 218 | break; |
| 219 | BYTECODE(SET_REGISTER_TO_SP) |
| 220 | registers[insn >> BYTECODE_SHIFT] = |
| 221 | static_cast<int>(backtrack_sp - backtrack_stack_base); |
| 222 | pc += BC_SET_REGISTER_TO_SP_LENGTH; |
| 223 | break; |
| 224 | BYTECODE(SET_SP_TO_REGISTER) |
| 225 | backtrack_sp = backtrack_stack_base + registers[insn >> BYTECODE_SHIFT]; |
| 226 | backtrack_stack_space = backtrack_stack.max_size() - |
| 227 | static_cast<int>(backtrack_sp - backtrack_stack_base); |
| 228 | pc += BC_SET_SP_TO_REGISTER_LENGTH; |
| 229 | break; |
| 230 | BYTECODE(POP_CP) |
| 231 | backtrack_stack_space++; |
| 232 | --backtrack_sp; |
| 233 | current = *backtrack_sp; |
| 234 | pc += BC_POP_CP_LENGTH; |
| 235 | break; |
| 236 | BYTECODE(POP_BT) |
| 237 | backtrack_stack_space++; |
| 238 | --backtrack_sp; |
| 239 | pc = code_base + *backtrack_sp; |
| 240 | break; |
| 241 | BYTECODE(POP_REGISTER) |
| 242 | backtrack_stack_space++; |
| 243 | --backtrack_sp; |
| 244 | registers[insn >> BYTECODE_SHIFT] = *backtrack_sp; |
| 245 | pc += BC_POP_REGISTER_LENGTH; |
| 246 | break; |
| 247 | BYTECODE(FAIL) |
| 248 | return RegExpImpl::RE_FAILURE; |
| 249 | BYTECODE(SUCCEED) |
| 250 | return RegExpImpl::RE_SUCCESS; |
| 251 | BYTECODE(ADVANCE_CP) |
| 252 | current += insn >> BYTECODE_SHIFT; |
| 253 | pc += BC_ADVANCE_CP_LENGTH; |
| 254 | break; |
| 255 | BYTECODE(GOTO) |
| 256 | pc = code_base + Load32Aligned(pc + 4); |
| 257 | break; |
| 258 | BYTECODE(ADVANCE_CP_AND_GOTO) |
| 259 | current += insn >> BYTECODE_SHIFT; |
| 260 | pc = code_base + Load32Aligned(pc + 4); |
| 261 | break; |
| 262 | BYTECODE(CHECK_GREEDY) |
| 263 | if (current == backtrack_sp[-1]) { |
| 264 | backtrack_sp--; |
| 265 | backtrack_stack_space++; |
| 266 | pc = code_base + Load32Aligned(pc + 4); |
| 267 | } else { |
| 268 | pc += BC_CHECK_GREEDY_LENGTH; |
| 269 | } |
| 270 | break; |
| 271 | BYTECODE(LOAD_CURRENT_CHAR) { |
| 272 | int pos = current + (insn >> BYTECODE_SHIFT); |
| 273 | if (pos >= subject.length() || pos < 0) { |
| 274 | pc = code_base + Load32Aligned(pc + 4); |
| 275 | } else { |
| 276 | current_char = subject[pos]; |
| 277 | pc += BC_LOAD_CURRENT_CHAR_LENGTH; |
| 278 | } |
| 279 | break; |
| 280 | } |
| 281 | BYTECODE(LOAD_CURRENT_CHAR_UNCHECKED) { |
| 282 | int pos = current + (insn >> BYTECODE_SHIFT); |
| 283 | current_char = subject[pos]; |
| 284 | pc += BC_LOAD_CURRENT_CHAR_UNCHECKED_LENGTH; |
| 285 | break; |
| 286 | } |
| 287 | BYTECODE(LOAD_2_CURRENT_CHARS) { |
| 288 | int pos = current + (insn >> BYTECODE_SHIFT); |
| 289 | if (pos + 2 > subject.length() || pos < 0) { |
| 290 | pc = code_base + Load32Aligned(pc + 4); |
| 291 | } else { |
| 292 | Char next = subject[pos + 1]; |
| 293 | current_char = |
| 294 | (subject[pos] | (next << (kBitsPerByte * sizeof(Char)))); |
| 295 | pc += BC_LOAD_2_CURRENT_CHARS_LENGTH; |
| 296 | } |
| 297 | break; |
| 298 | } |
| 299 | BYTECODE(LOAD_2_CURRENT_CHARS_UNCHECKED) { |
| 300 | int pos = current + (insn >> BYTECODE_SHIFT); |
| 301 | Char next = subject[pos + 1]; |
| 302 | current_char = (subject[pos] | (next << (kBitsPerByte * sizeof(Char)))); |
| 303 | pc += BC_LOAD_2_CURRENT_CHARS_UNCHECKED_LENGTH; |
| 304 | break; |
| 305 | } |
| 306 | BYTECODE(LOAD_4_CURRENT_CHARS) { |
| 307 | DCHECK(sizeof(Char) == 1); |
| 308 | int pos = current + (insn >> BYTECODE_SHIFT); |
| 309 | if (pos + 4 > subject.length() || pos < 0) { |
| 310 | pc = code_base + Load32Aligned(pc + 4); |
| 311 | } else { |
| 312 | Char next1 = subject[pos + 1]; |
| 313 | Char next2 = subject[pos + 2]; |
| 314 | Char next3 = subject[pos + 3]; |
| 315 | current_char = (subject[pos] | |
| 316 | (next1 << 8) | |
| 317 | (next2 << 16) | |
| 318 | (next3 << 24)); |
| 319 | pc += BC_LOAD_4_CURRENT_CHARS_LENGTH; |
| 320 | } |
| 321 | break; |
| 322 | } |
| 323 | BYTECODE(LOAD_4_CURRENT_CHARS_UNCHECKED) { |
| 324 | DCHECK(sizeof(Char) == 1); |
| 325 | int pos = current + (insn >> BYTECODE_SHIFT); |
| 326 | Char next1 = subject[pos + 1]; |
| 327 | Char next2 = subject[pos + 2]; |
| 328 | Char next3 = subject[pos + 3]; |
| 329 | current_char = (subject[pos] | |
| 330 | (next1 << 8) | |
| 331 | (next2 << 16) | |
| 332 | (next3 << 24)); |
| 333 | pc += BC_LOAD_4_CURRENT_CHARS_UNCHECKED_LENGTH; |
| 334 | break; |
| 335 | } |
| 336 | BYTECODE(CHECK_4_CHARS) { |
| 337 | uint32_t c = Load32Aligned(pc + 4); |
| 338 | if (c == current_char) { |
| 339 | pc = code_base + Load32Aligned(pc + 8); |
| 340 | } else { |
| 341 | pc += BC_CHECK_4_CHARS_LENGTH; |
| 342 | } |
| 343 | break; |
| 344 | } |
| 345 | BYTECODE(CHECK_CHAR) { |
| 346 | uint32_t c = (insn >> BYTECODE_SHIFT); |
| 347 | if (c == current_char) { |
| 348 | pc = code_base + Load32Aligned(pc + 4); |
| 349 | } else { |
| 350 | pc += BC_CHECK_CHAR_LENGTH; |
| 351 | } |
| 352 | break; |
| 353 | } |
| 354 | BYTECODE(CHECK_NOT_4_CHARS) { |
| 355 | uint32_t c = Load32Aligned(pc + 4); |
| 356 | if (c != current_char) { |
| 357 | pc = code_base + Load32Aligned(pc + 8); |
| 358 | } else { |
| 359 | pc += BC_CHECK_NOT_4_CHARS_LENGTH; |
| 360 | } |
| 361 | break; |
| 362 | } |
| 363 | BYTECODE(CHECK_NOT_CHAR) { |
| 364 | uint32_t c = (insn >> BYTECODE_SHIFT); |
| 365 | if (c != current_char) { |
| 366 | pc = code_base + Load32Aligned(pc + 4); |
| 367 | } else { |
| 368 | pc += BC_CHECK_NOT_CHAR_LENGTH; |
| 369 | } |
| 370 | break; |
| 371 | } |
| 372 | BYTECODE(AND_CHECK_4_CHARS) { |
| 373 | uint32_t c = Load32Aligned(pc + 4); |
| 374 | if (c == (current_char & Load32Aligned(pc + 8))) { |
| 375 | pc = code_base + Load32Aligned(pc + 12); |
| 376 | } else { |
| 377 | pc += BC_AND_CHECK_4_CHARS_LENGTH; |
| 378 | } |
| 379 | break; |
| 380 | } |
| 381 | BYTECODE(AND_CHECK_CHAR) { |
| 382 | uint32_t c = (insn >> BYTECODE_SHIFT); |
| 383 | if (c == (current_char & Load32Aligned(pc + 4))) { |
| 384 | pc = code_base + Load32Aligned(pc + 8); |
| 385 | } else { |
| 386 | pc += BC_AND_CHECK_CHAR_LENGTH; |
| 387 | } |
| 388 | break; |
| 389 | } |
| 390 | BYTECODE(AND_CHECK_NOT_4_CHARS) { |
| 391 | uint32_t c = Load32Aligned(pc + 4); |
| 392 | if (c != (current_char & Load32Aligned(pc + 8))) { |
| 393 | pc = code_base + Load32Aligned(pc + 12); |
| 394 | } else { |
| 395 | pc += BC_AND_CHECK_NOT_4_CHARS_LENGTH; |
| 396 | } |
| 397 | break; |
| 398 | } |
| 399 | BYTECODE(AND_CHECK_NOT_CHAR) { |
| 400 | uint32_t c = (insn >> BYTECODE_SHIFT); |
| 401 | if (c != (current_char & Load32Aligned(pc + 4))) { |
| 402 | pc = code_base + Load32Aligned(pc + 8); |
| 403 | } else { |
| 404 | pc += BC_AND_CHECK_NOT_CHAR_LENGTH; |
| 405 | } |
| 406 | break; |
| 407 | } |
| 408 | BYTECODE(MINUS_AND_CHECK_NOT_CHAR) { |
| 409 | uint32_t c = (insn >> BYTECODE_SHIFT); |
| 410 | uint32_t minus = Load16Aligned(pc + 4); |
| 411 | uint32_t mask = Load16Aligned(pc + 6); |
| 412 | if (c != ((current_char - minus) & mask)) { |
| 413 | pc = code_base + Load32Aligned(pc + 8); |
| 414 | } else { |
| 415 | pc += BC_MINUS_AND_CHECK_NOT_CHAR_LENGTH; |
| 416 | } |
| 417 | break; |
| 418 | } |
| 419 | BYTECODE(CHECK_CHAR_IN_RANGE) { |
| 420 | uint32_t from = Load16Aligned(pc + 4); |
| 421 | uint32_t to = Load16Aligned(pc + 6); |
| 422 | if (from <= current_char && current_char <= to) { |
| 423 | pc = code_base + Load32Aligned(pc + 8); |
| 424 | } else { |
| 425 | pc += BC_CHECK_CHAR_IN_RANGE_LENGTH; |
| 426 | } |
| 427 | break; |
| 428 | } |
| 429 | BYTECODE(CHECK_CHAR_NOT_IN_RANGE) { |
| 430 | uint32_t from = Load16Aligned(pc + 4); |
| 431 | uint32_t to = Load16Aligned(pc + 6); |
| 432 | if (from > current_char || current_char > to) { |
| 433 | pc = code_base + Load32Aligned(pc + 8); |
| 434 | } else { |
| 435 | pc += BC_CHECK_CHAR_NOT_IN_RANGE_LENGTH; |
| 436 | } |
| 437 | break; |
| 438 | } |
| 439 | BYTECODE(CHECK_BIT_IN_TABLE) { |
| 440 | int mask = RegExpMacroAssembler::kTableMask; |
| 441 | byte b = pc[8 + ((current_char & mask) >> kBitsPerByteLog2)]; |
| 442 | int bit = (current_char & (kBitsPerByte - 1)); |
| 443 | if ((b & (1 << bit)) != 0) { |
| 444 | pc = code_base + Load32Aligned(pc + 4); |
| 445 | } else { |
| 446 | pc += BC_CHECK_BIT_IN_TABLE_LENGTH; |
| 447 | } |
| 448 | break; |
| 449 | } |
| 450 | BYTECODE(CHECK_LT) { |
| 451 | uint32_t limit = (insn >> BYTECODE_SHIFT); |
| 452 | if (current_char < limit) { |
| 453 | pc = code_base + Load32Aligned(pc + 4); |
| 454 | } else { |
| 455 | pc += BC_CHECK_LT_LENGTH; |
| 456 | } |
| 457 | break; |
| 458 | } |
| 459 | BYTECODE(CHECK_GT) { |
| 460 | uint32_t limit = (insn >> BYTECODE_SHIFT); |
| 461 | if (current_char > limit) { |
| 462 | pc = code_base + Load32Aligned(pc + 4); |
| 463 | } else { |
| 464 | pc += BC_CHECK_GT_LENGTH; |
| 465 | } |
| 466 | break; |
| 467 | } |
| 468 | BYTECODE(CHECK_REGISTER_LT) |
| 469 | if (registers[insn >> BYTECODE_SHIFT] < Load32Aligned(pc + 4)) { |
| 470 | pc = code_base + Load32Aligned(pc + 8); |
| 471 | } else { |
| 472 | pc += BC_CHECK_REGISTER_LT_LENGTH; |
| 473 | } |
| 474 | break; |
| 475 | BYTECODE(CHECK_REGISTER_GE) |
| 476 | if (registers[insn >> BYTECODE_SHIFT] >= Load32Aligned(pc + 4)) { |
| 477 | pc = code_base + Load32Aligned(pc + 8); |
| 478 | } else { |
| 479 | pc += BC_CHECK_REGISTER_GE_LENGTH; |
| 480 | } |
| 481 | break; |
| 482 | BYTECODE(CHECK_REGISTER_EQ_POS) |
| 483 | if (registers[insn >> BYTECODE_SHIFT] == current) { |
| 484 | pc = code_base + Load32Aligned(pc + 4); |
| 485 | } else { |
| 486 | pc += BC_CHECK_REGISTER_EQ_POS_LENGTH; |
| 487 | } |
| 488 | break; |
| 489 | BYTECODE(CHECK_NOT_REGS_EQUAL) |
| 490 | if (registers[insn >> BYTECODE_SHIFT] == |
| 491 | registers[Load32Aligned(pc + 4)]) { |
| 492 | pc += BC_CHECK_NOT_REGS_EQUAL_LENGTH; |
| 493 | } else { |
| 494 | pc = code_base + Load32Aligned(pc + 8); |
| 495 | } |
| 496 | break; |
| 497 | BYTECODE(CHECK_NOT_BACK_REF) { |
| 498 | int from = registers[insn >> BYTECODE_SHIFT]; |
| 499 | int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from; |
| 500 | if (from >= 0 && len > 0) { |
| 501 | if (current + len > subject.length() || |
| 502 | CompareChars(&subject[from], &subject[current], len) != 0) { |
| 503 | pc = code_base + Load32Aligned(pc + 4); |
| 504 | break; |
| 505 | } |
| 506 | current += len; |
| 507 | } |
| 508 | pc += BC_CHECK_NOT_BACK_REF_LENGTH; |
| 509 | break; |
| 510 | } |
| 511 | BYTECODE(CHECK_NOT_BACK_REF_BACKWARD) { |
| 512 | int from = registers[insn >> BYTECODE_SHIFT]; |
| 513 | int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from; |
| 514 | if (from >= 0 && len > 0) { |
| 515 | if (current - len < 0 || |
| 516 | CompareChars(&subject[from], &subject[current - len], len) != 0) { |
| 517 | pc = code_base + Load32Aligned(pc + 4); |
| 518 | break; |
| 519 | } |
| 520 | current -= len; |
| 521 | } |
| 522 | pc += BC_CHECK_NOT_BACK_REF_BACKWARD_LENGTH; |
| 523 | break; |
| 524 | } |
| 525 | BYTECODE(CHECK_NOT_BACK_REF_NO_CASE) { |
| 526 | int from = registers[insn >> BYTECODE_SHIFT]; |
| 527 | int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from; |
| 528 | if (from >= 0 && len > 0) { |
| 529 | if (current + len > subject.length() || |
| 530 | !BackRefMatchesNoCase(isolate->interp_canonicalize_mapping(), |
| 531 | from, current, len, subject)) { |
| 532 | pc = code_base + Load32Aligned(pc + 4); |
| 533 | break; |
| 534 | } |
| 535 | current += len; |
| 536 | } |
| 537 | pc += BC_CHECK_NOT_BACK_REF_NO_CASE_LENGTH; |
| 538 | break; |
| 539 | } |
| 540 | BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD) { |
| 541 | int from = registers[insn >> BYTECODE_SHIFT]; |
| 542 | int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from; |
| 543 | if (from >= 0 && len > 0) { |
| 544 | if (current - len < 0 || |
| 545 | !BackRefMatchesNoCase(isolate->interp_canonicalize_mapping(), |
| 546 | from, current - len, len, subject)) { |
| 547 | pc = code_base + Load32Aligned(pc + 4); |
| 548 | break; |
| 549 | } |
| 550 | current -= len; |
| 551 | } |
| 552 | pc += BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD_LENGTH; |
| 553 | break; |
| 554 | } |
| 555 | BYTECODE(CHECK_AT_START) |
| 556 | if (current == 0) { |
| 557 | pc = code_base + Load32Aligned(pc + 4); |
| 558 | } else { |
| 559 | pc += BC_CHECK_AT_START_LENGTH; |
| 560 | } |
| 561 | break; |
| 562 | BYTECODE(CHECK_NOT_AT_START) |
| 563 | if (current + (insn >> BYTECODE_SHIFT) == 0) { |
| 564 | pc += BC_CHECK_NOT_AT_START_LENGTH; |
| 565 | } else { |
| 566 | pc = code_base + Load32Aligned(pc + 4); |
| 567 | } |
| 568 | break; |
| 569 | BYTECODE(SET_CURRENT_POSITION_FROM_END) { |
| 570 | int by = static_cast<uint32_t>(insn) >> BYTECODE_SHIFT; |
| 571 | if (subject.length() - current > by) { |
| 572 | current = subject.length() - by; |
| 573 | current_char = subject[current - 1]; |
| 574 | } |
| 575 | pc += BC_SET_CURRENT_POSITION_FROM_END_LENGTH; |
| 576 | break; |
| 577 | } |
| 578 | default: |
| 579 | UNREACHABLE(); |
| 580 | break; |
| 581 | } |
| 582 | } |
| 583 | } |
| 584 | |
| 585 | |
| 586 | RegExpImpl::IrregexpResult IrregexpInterpreter::Match( |
| 587 | Isolate* isolate, |
| 588 | Handle<ByteArray> code_array, |
| 589 | Handle<String> subject, |
| 590 | int* registers, |
| 591 | int start_position) { |
| 592 | DCHECK(subject->IsFlat()); |
| 593 | |
| 594 | DisallowHeapAllocation no_gc; |
| 595 | const byte* code_base = code_array->GetDataStartAddress(); |
| 596 | uc16 previous_char = '\n'; |
| 597 | String::FlatContent subject_content = subject->GetFlatContent(); |
| 598 | if (subject_content.IsOneByte()) { |
| 599 | Vector<const uint8_t> subject_vector = subject_content.ToOneByteVector(); |
| 600 | if (start_position != 0) previous_char = subject_vector[start_position - 1]; |
| 601 | return RawMatch(isolate, |
| 602 | code_base, |
| 603 | subject_vector, |
| 604 | registers, |
| 605 | start_position, |
| 606 | previous_char); |
| 607 | } else { |
| 608 | DCHECK(subject_content.IsTwoByte()); |
| 609 | Vector<const uc16> subject_vector = subject_content.ToUC16Vector(); |
| 610 | if (start_position != 0) previous_char = subject_vector[start_position - 1]; |
| 611 | return RawMatch(isolate, |
| 612 | code_base, |
| 613 | subject_vector, |
| 614 | registers, |
| 615 | start_position, |
| 616 | previous_char); |
| 617 | } |
| 618 | } |
| 619 | |
| 620 | } // namespace internal |
| 621 | } // namespace v8 |