| 1 | /* Extended regular expression matching and search library. |
| 2 | Copyright (C) 1985, 1989 Free Software Foundation, Inc. |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of the GNU General Public License as published by |
| 6 | the Free Software Foundation; either version 2 of the License, or |
| 7 | (at your option) any later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program; if not, write to the Free Software |
| 16 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 17 | |
| 18 | /* To test, compile with -Dtest. |
| 19 | This Dtestable feature turns this into a self-contained program |
| 20 | which reads a pattern, describes how it compiles, |
| 21 | then reads a string and searches for it. */ |
| 22 | |
| 23 | #ifdef emacs |
| 24 | |
| 25 | /* The `emacs' switch turns on certain special matching commands |
| 26 | that make sense only in emacs. */ |
| 27 | |
| 28 | #include "config.h" |
| 29 | #include "lisp.h" |
| 30 | #include "buffer.h" |
| 31 | #include "syntax.h" |
| 32 | |
| 33 | #else /* not emacs */ |
| 34 | |
| 35 | /* Make alloca work the best possible way. */ |
| 36 | #ifdef __GNUC__ |
| 37 | #define alloca __builtin_alloca |
| 38 | #else |
| 39 | #ifdef sparc |
| 40 | #include <alloca.h> |
| 41 | #endif |
| 42 | #endif |
| 43 | |
| 44 | /* |
| 45 | * Define the syntax stuff, so we can do the \<...\> things. |
| 46 | */ |
| 47 | |
| 48 | #ifndef Sword /* must be non-zero in some of the tests below... */ |
| 49 | #define Sword 1 |
| 50 | #endif |
| 51 | |
| 52 | #define SYNTAX(c) re_syntax_table[c] |
| 53 | |
| 54 | #ifdef SYNTAX_TABLE |
| 55 | |
| 56 | char *re_syntax_table; |
| 57 | |
| 58 | #else |
| 59 | |
| 60 | static char re_syntax_table[256]; |
| 61 | |
| 62 | static void |
| 63 | init_syntax_once () |
| 64 | { |
| 65 | register int c; |
| 66 | static int done = 0; |
| 67 | |
| 68 | if (done) |
| 69 | return; |
| 70 | |
| 71 | memset (re_syntax_table, '\0', sizeof re_syntax_table); |
| 72 | |
| 73 | for (c = 'a'; c <= 'z'; c++) |
| 74 | re_syntax_table[c] = Sword; |
| 75 | |
| 76 | for (c = 'A'; c <= 'Z'; c++) |
| 77 | re_syntax_table[c] = Sword; |
| 78 | |
| 79 | for (c = '0'; c <= '9'; c++) |
| 80 | re_syntax_table[c] = Sword; |
| 81 | |
| 82 | done = 1; |
| 83 | } |
| 84 | |
| 85 | #endif /* SYNTAX_TABLE */ |
| 86 | #endif /* not emacs */ |
| 87 | |
| 88 | #include "regex.h" |
| 89 | |
| 90 | /* Number of failure points to allocate space for initially, |
| 91 | when matching. If this number is exceeded, more space is allocated, |
| 92 | so it is not a hard limit. */ |
| 93 | |
| 94 | #ifndef NFAILURES |
| 95 | #define NFAILURES 80 |
| 96 | #endif /* NFAILURES */ |
| 97 | |
| 98 | /* width of a byte in bits */ |
| 99 | |
| 100 | #define BYTEWIDTH 8 |
| 101 | |
| 102 | #ifndef SIGN_EXTEND_CHAR |
| 103 | #define SIGN_EXTEND_CHAR(x) (x) |
| 104 | #endif |
| 105 | \f |
| 106 | static int obscure_syntax = 0; |
| 107 | |
| 108 | /* Specify the precise syntax of regexp for compilation. |
| 109 | This provides for compatibility for various utilities |
| 110 | which historically have different, incompatible syntaxes. |
| 111 | |
| 112 | The argument SYNTAX is a bit-mask containing the two bits |
| 113 | RE_NO_BK_PARENS and RE_NO_BK_VBAR. */ |
| 114 | |
| 115 | int |
| 116 | re_set_syntax (syntax) |
| 117 | int syntax; |
| 118 | { |
| 119 | int ret; |
| 120 | |
| 121 | ret = obscure_syntax; |
| 122 | obscure_syntax = syntax; |
| 123 | return ret; |
| 124 | } |
| 125 | \f |
| 126 | /* re_compile_pattern takes a regular-expression string |
| 127 | and converts it into a buffer full of byte commands for matching. |
| 128 | |
| 129 | PATTERN is the address of the pattern string |
| 130 | SIZE is the length of it. |
| 131 | BUFP is a struct re_pattern_buffer * which points to the info |
| 132 | on where to store the byte commands. |
| 133 | This structure contains a char * which points to the |
| 134 | actual space, which should have been obtained with malloc. |
| 135 | re_compile_pattern may use realloc to grow the buffer space. |
| 136 | |
| 137 | The number of bytes of commands can be found out by looking in |
| 138 | the struct re_pattern_buffer that bufp pointed to, |
| 139 | after re_compile_pattern returns. |
| 140 | */ |
| 141 | |
| 142 | #define PATPUSH(ch) (*b++ = (char) (ch)) |
| 143 | |
| 144 | #define PATFETCH(c) \ |
| 145 | {if (p == pend) goto end_of_pattern; \ |
| 146 | c = * (unsigned char *) p++; \ |
| 147 | if (translate) c = translate[c]; } |
| 148 | |
| 149 | #define PATFETCH_RAW(c) \ |
| 150 | {if (p == pend) goto end_of_pattern; \ |
| 151 | c = * (unsigned char *) p++; } |
| 152 | |
| 153 | #define PATUNFETCH p-- |
| 154 | |
| 155 | #define EXTEND_BUFFER \ |
| 156 | { char *old_buffer = bufp->buffer; \ |
| 157 | if (bufp->allocated == (1<<16)) goto too_big; \ |
| 158 | bufp->allocated *= 2; \ |
| 159 | if (bufp->allocated > (1<<16)) bufp->allocated = (1<<16); \ |
| 160 | if (!(bufp->buffer = (char *) realloc (bufp->buffer, bufp->allocated))) \ |
| 161 | goto memory_exhausted; \ |
| 162 | c = bufp->buffer - old_buffer; \ |
| 163 | b += c; \ |
| 164 | if (fixup_jump) \ |
| 165 | fixup_jump += c; \ |
| 166 | if (laststart) \ |
| 167 | laststart += c; \ |
| 168 | begalt += c; \ |
| 169 | if (pending_exact) \ |
| 170 | pending_exact += c; \ |
| 171 | } |
| 172 | |
| 173 | static void store_jump (), insert_jump (); |
| 174 | |
| 175 | char * |
| 176 | re_compile_pattern (pattern, size, bufp) |
| 177 | char *pattern; |
| 178 | int size; |
| 179 | struct re_pattern_buffer *bufp; |
| 180 | { |
| 181 | register char *b = bufp->buffer; |
| 182 | register char *p = pattern; |
| 183 | char *pend = pattern + size; |
| 184 | register unsigned c, c1; |
| 185 | char *p1; |
| 186 | unsigned char *translate = (unsigned char *) bufp->translate; |
| 187 | |
| 188 | /* address of the count-byte of the most recently inserted "exactn" command. |
| 189 | This makes it possible to tell whether a new exact-match character |
| 190 | can be added to that command or requires a new "exactn" command. */ |
| 191 | |
| 192 | char *pending_exact = 0; |
| 193 | |
| 194 | /* address of the place where a forward-jump should go |
| 195 | to the end of the containing expression. |
| 196 | Each alternative of an "or", except the last, ends with a forward-jump |
| 197 | of this sort. */ |
| 198 | |
| 199 | char *fixup_jump = 0; |
| 200 | |
| 201 | /* address of start of the most recently finished expression. |
| 202 | This tells postfix * where to find the start of its operand. */ |
| 203 | |
| 204 | char *laststart = 0; |
| 205 | |
| 206 | /* In processing a repeat, 1 means zero matches is allowed */ |
| 207 | |
| 208 | char zero_times_ok; |
| 209 | |
| 210 | /* In processing a repeat, 1 means many matches is allowed */ |
| 211 | |
| 212 | char many_times_ok; |
| 213 | |
| 214 | /* address of beginning of regexp, or inside of last \( */ |
| 215 | |
| 216 | char *begalt = b; |
| 217 | |
| 218 | /* Stack of information saved by \( and restored by \). |
| 219 | Four stack elements are pushed by each \(: |
| 220 | First, the value of b. |
| 221 | Second, the value of fixup_jump. |
| 222 | Third, the value of regnum. |
| 223 | Fourth, the value of begalt. */ |
| 224 | |
| 225 | int stackb[40]; |
| 226 | int *stackp = stackb; |
| 227 | int *stacke = stackb + 40; |
| 228 | int *stackt; |
| 229 | |
| 230 | /* Counts \('s as they are encountered. Remembered for the matching \), |
| 231 | where it becomes the "register number" to put in the stop_memory command */ |
| 232 | |
| 233 | int regnum = 1; |
| 234 | |
| 235 | bufp->fastmap_accurate = 0; |
| 236 | |
| 237 | #ifndef emacs |
| 238 | #ifndef SYNTAX_TABLE |
| 239 | /* |
| 240 | * Initialize the syntax table. |
| 241 | */ |
| 242 | init_syntax_once(); |
| 243 | #endif |
| 244 | #endif |
| 245 | |
| 246 | if (bufp->allocated == 0) |
| 247 | { |
| 248 | bufp->allocated = 28; |
| 249 | if (bufp->buffer) |
| 250 | /* EXTEND_BUFFER loses when bufp->allocated is 0 */ |
| 251 | bufp->buffer = (char *) realloc (bufp->buffer, 28); |
| 252 | else |
| 253 | /* Caller did not allocate a buffer. Do it for him */ |
| 254 | bufp->buffer = (char *) malloc (28); |
| 255 | if (!bufp->buffer) goto memory_exhausted; |
| 256 | begalt = b = bufp->buffer; |
| 257 | } |
| 258 | |
| 259 | while (p != pend) |
| 260 | { |
| 261 | if (b - bufp->buffer > bufp->allocated - 10) |
| 262 | /* Note that EXTEND_BUFFER clobbers c */ |
| 263 | EXTEND_BUFFER; |
| 264 | |
| 265 | PATFETCH (c); |
| 266 | |
| 267 | switch (c) |
| 268 | { |
| 269 | case '$': |
| 270 | if (obscure_syntax & RE_TIGHT_VBAR) |
| 271 | { |
| 272 | if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS) && p != pend) |
| 273 | goto normal_char; |
| 274 | /* Make operand of last vbar end before this `$'. */ |
| 275 | if (fixup_jump) |
| 276 | store_jump (fixup_jump, jump, b); |
| 277 | fixup_jump = 0; |
| 278 | PATPUSH (endline); |
| 279 | break; |
| 280 | } |
| 281 | |
| 282 | /* $ means succeed if at end of line, but only in special contexts. |
| 283 | If randomly in the middle of a pattern, it is a normal character. */ |
| 284 | if (p == pend || *p == '\n' |
| 285 | || (obscure_syntax & RE_CONTEXT_INDEP_OPS) |
| 286 | || (obscure_syntax & RE_NO_BK_PARENS |
| 287 | ? *p == ')' |
| 288 | : *p == '\\' && p[1] == ')') |
| 289 | || (obscure_syntax & RE_NO_BK_VBAR |
| 290 | ? *p == '|' |
| 291 | : *p == '\\' && p[1] == '|')) |
| 292 | { |
| 293 | PATPUSH (endline); |
| 294 | break; |
| 295 | } |
| 296 | goto normal_char; |
| 297 | |
| 298 | case '^': |
| 299 | /* ^ means succeed if at beg of line, but only if no preceding pattern. */ |
| 300 | |
| 301 | if (laststart && p[-2] != '\n' |
| 302 | && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) |
| 303 | goto normal_char; |
| 304 | if (obscure_syntax & RE_TIGHT_VBAR) |
| 305 | { |
| 306 | if (p != pattern + 1 |
| 307 | && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) |
| 308 | goto normal_char; |
| 309 | PATPUSH (begline); |
| 310 | begalt = b; |
| 311 | } |
| 312 | else |
| 313 | PATPUSH (begline); |
| 314 | break; |
| 315 | |
| 316 | case '+': |
| 317 | case '?': |
| 318 | if (obscure_syntax & RE_BK_PLUS_QM) |
| 319 | goto normal_char; |
| 320 | handle_plus: |
| 321 | case '*': |
| 322 | /* If there is no previous pattern, char not special. */ |
| 323 | if (!laststart && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) |
| 324 | goto normal_char; |
| 325 | /* If there is a sequence of repetition chars, |
| 326 | collapse it down to equivalent to just one. */ |
| 327 | zero_times_ok = 0; |
| 328 | many_times_ok = 0; |
| 329 | while (1) |
| 330 | { |
| 331 | zero_times_ok |= c != '+'; |
| 332 | many_times_ok |= c != '?'; |
| 333 | if (p == pend) |
| 334 | break; |
| 335 | PATFETCH (c); |
| 336 | if (c == '*') |
| 337 | ; |
| 338 | else if (!(obscure_syntax & RE_BK_PLUS_QM) |
| 339 | && (c == '+' || c == '?')) |
| 340 | ; |
| 341 | else if ((obscure_syntax & RE_BK_PLUS_QM) |
| 342 | && c == '\\') |
| 343 | { |
| 344 | int c1; |
| 345 | PATFETCH (c1); |
| 346 | if (!(c1 == '+' || c1 == '?')) |
| 347 | { |
| 348 | PATUNFETCH; |
| 349 | PATUNFETCH; |
| 350 | break; |
| 351 | } |
| 352 | c = c1; |
| 353 | } |
| 354 | else |
| 355 | { |
| 356 | PATUNFETCH; |
| 357 | break; |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | /* Star, etc. applied to an empty pattern is equivalent |
| 362 | to an empty pattern. */ |
| 363 | if (!laststart) |
| 364 | break; |
| 365 | |
| 366 | /* Now we know whether 0 matches is allowed, |
| 367 | and whether 2 or more matches is allowed. */ |
| 368 | if (many_times_ok) |
| 369 | { |
| 370 | /* If more than one repetition is allowed, |
| 371 | put in a backward jump at the end. */ |
| 372 | store_jump (b, maybe_finalize_jump, laststart - 3); |
| 373 | b += 3; |
| 374 | } |
| 375 | insert_jump (on_failure_jump, laststart, b + 3, b); |
| 376 | pending_exact = 0; |
| 377 | b += 3; |
| 378 | if (!zero_times_ok) |
| 379 | { |
| 380 | /* At least one repetition required: insert before the loop |
| 381 | a skip over the initial on-failure-jump instruction */ |
| 382 | insert_jump (dummy_failure_jump, laststart, laststart + 6, b); |
| 383 | b += 3; |
| 384 | } |
| 385 | break; |
| 386 | |
| 387 | case '.': |
| 388 | laststart = b; |
| 389 | PATPUSH (anychar); |
| 390 | break; |
| 391 | |
| 392 | case '[': |
| 393 | while (b - bufp->buffer |
| 394 | > bufp->allocated - 3 - (1 << BYTEWIDTH) / BYTEWIDTH) |
| 395 | /* Note that EXTEND_BUFFER clobbers c */ |
| 396 | EXTEND_BUFFER; |
| 397 | |
| 398 | laststart = b; |
| 399 | if (*p == '^') |
| 400 | PATPUSH (charset_not), p++; |
| 401 | else |
| 402 | PATPUSH (charset); |
| 403 | p1 = p; |
| 404 | |
| 405 | PATPUSH ((1 << BYTEWIDTH) / BYTEWIDTH); |
| 406 | /* Clear the whole map */ |
| 407 | memset (b, '\0', (1 << BYTEWIDTH) / BYTEWIDTH); |
| 408 | /* Read in characters and ranges, setting map bits */ |
| 409 | while (1) |
| 410 | { |
| 411 | PATFETCH (c); |
| 412 | if (c == ']' && p != p1 + 1) break; |
| 413 | if (*p == '-' && p[1] != ']') |
| 414 | { |
| 415 | PATFETCH (c1); |
| 416 | PATFETCH (c1); |
| 417 | while (c <= c1) |
| 418 | b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH), c++; |
| 419 | } |
| 420 | else |
| 421 | { |
| 422 | b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH); |
| 423 | } |
| 424 | } |
| 425 | /* Discard any bitmap bytes that are all 0 at the end of the map. |
| 426 | Decrement the map-length byte too. */ |
| 427 | while ((int) b[-1] > 0 && b[b[-1] - 1] == 0) |
| 428 | b[-1]--; |
| 429 | b += b[-1]; |
| 430 | break; |
| 431 | |
| 432 | case '(': |
| 433 | if (! (obscure_syntax & RE_NO_BK_PARENS)) |
| 434 | goto normal_char; |
| 435 | else |
| 436 | goto handle_open; |
| 437 | |
| 438 | case ')': |
| 439 | if (! (obscure_syntax & RE_NO_BK_PARENS)) |
| 440 | goto normal_char; |
| 441 | else |
| 442 | goto handle_close; |
| 443 | |
| 444 | case '\n': |
| 445 | if (! (obscure_syntax & RE_NEWLINE_OR)) |
| 446 | goto normal_char; |
| 447 | else |
| 448 | goto handle_bar; |
| 449 | |
| 450 | case '|': |
| 451 | if (! (obscure_syntax & RE_NO_BK_VBAR)) |
| 452 | goto normal_char; |
| 453 | else |
| 454 | goto handle_bar; |
| 455 | |
| 456 | case '\\': |
| 457 | if (p == pend) goto invalid_pattern; |
| 458 | PATFETCH_RAW (c); |
| 459 | switch (c) |
| 460 | { |
| 461 | case '(': |
| 462 | if (obscure_syntax & RE_NO_BK_PARENS) |
| 463 | goto normal_backsl; |
| 464 | handle_open: |
| 465 | if (stackp == stacke) goto nesting_too_deep; |
| 466 | if (regnum < RE_NREGS) |
| 467 | { |
| 468 | PATPUSH (start_memory); |
| 469 | PATPUSH (regnum); |
| 470 | } |
| 471 | *stackp++ = b - bufp->buffer; |
| 472 | *stackp++ = fixup_jump ? fixup_jump - bufp->buffer + 1 : 0; |
| 473 | *stackp++ = regnum++; |
| 474 | *stackp++ = begalt - bufp->buffer; |
| 475 | fixup_jump = 0; |
| 476 | laststart = 0; |
| 477 | begalt = b; |
| 478 | break; |
| 479 | |
| 480 | case ')': |
| 481 | if (obscure_syntax & RE_NO_BK_PARENS) |
| 482 | goto normal_backsl; |
| 483 | handle_close: |
| 484 | if (stackp == stackb) goto unmatched_close; |
| 485 | begalt = *--stackp + bufp->buffer; |
| 486 | if (fixup_jump) |
| 487 | store_jump (fixup_jump, jump, b); |
| 488 | if (stackp[-1] < RE_NREGS) |
| 489 | { |
| 490 | PATPUSH (stop_memory); |
| 491 | PATPUSH (stackp[-1]); |
| 492 | } |
| 493 | stackp -= 2; |
| 494 | fixup_jump = 0; |
| 495 | if (*stackp) |
| 496 | fixup_jump = *stackp + bufp->buffer - 1; |
| 497 | laststart = *--stackp + bufp->buffer; |
| 498 | break; |
| 499 | |
| 500 | case '|': |
| 501 | if (obscure_syntax & RE_NO_BK_VBAR) |
| 502 | goto normal_backsl; |
| 503 | handle_bar: |
| 504 | insert_jump (on_failure_jump, begalt, b + 6, b); |
| 505 | pending_exact = 0; |
| 506 | b += 3; |
| 507 | if (fixup_jump) |
| 508 | store_jump (fixup_jump, jump, b); |
| 509 | fixup_jump = b; |
| 510 | b += 3; |
| 511 | laststart = 0; |
| 512 | begalt = b; |
| 513 | break; |
| 514 | |
| 515 | #ifdef emacs |
| 516 | case '=': |
| 517 | PATPUSH (at_dot); |
| 518 | break; |
| 519 | |
| 520 | case 's': |
| 521 | laststart = b; |
| 522 | PATPUSH (syntaxspec); |
| 523 | PATFETCH (c); |
| 524 | PATPUSH (syntax_spec_code[c]); |
| 525 | break; |
| 526 | |
| 527 | case 'S': |
| 528 | laststart = b; |
| 529 | PATPUSH (notsyntaxspec); |
| 530 | PATFETCH (c); |
| 531 | PATPUSH (syntax_spec_code[c]); |
| 532 | break; |
| 533 | #endif /* emacs */ |
| 534 | |
| 535 | case 'w': |
| 536 | laststart = b; |
| 537 | PATPUSH (wordchar); |
| 538 | break; |
| 539 | |
| 540 | case 'W': |
| 541 | laststart = b; |
| 542 | PATPUSH (notwordchar); |
| 543 | break; |
| 544 | |
| 545 | case '<': |
| 546 | PATPUSH (wordbeg); |
| 547 | break; |
| 548 | |
| 549 | case '>': |
| 550 | PATPUSH (wordend); |
| 551 | break; |
| 552 | |
| 553 | case 'b': |
| 554 | PATPUSH (wordbound); |
| 555 | break; |
| 556 | |
| 557 | case 'B': |
| 558 | PATPUSH (notwordbound); |
| 559 | break; |
| 560 | |
| 561 | case '`': |
| 562 | PATPUSH (begbuf); |
| 563 | break; |
| 564 | |
| 565 | case '\'': |
| 566 | PATPUSH (endbuf); |
| 567 | break; |
| 568 | |
| 569 | case '1': |
| 570 | case '2': |
| 571 | case '3': |
| 572 | case '4': |
| 573 | case '5': |
| 574 | case '6': |
| 575 | case '7': |
| 576 | case '8': |
| 577 | case '9': |
| 578 | c1 = c - '0'; |
| 579 | if (c1 >= regnum) |
| 580 | goto normal_char; |
| 581 | for (stackt = stackp - 2; stackt > stackb; stackt -= 4) |
| 582 | if (*stackt == c1) |
| 583 | goto normal_char; |
| 584 | laststart = b; |
| 585 | PATPUSH (duplicate); |
| 586 | PATPUSH (c1); |
| 587 | break; |
| 588 | |
| 589 | case '+': |
| 590 | case '?': |
| 591 | if (obscure_syntax & RE_BK_PLUS_QM) |
| 592 | goto handle_plus; |
| 593 | |
| 594 | default: |
| 595 | normal_backsl: |
| 596 | /* You might think it would be useful for \ to mean |
| 597 | not to translate; but if we don't translate it |
| 598 | it will never match anything. */ |
| 599 | if (translate) c = translate[c]; |
| 600 | goto normal_char; |
| 601 | } |
| 602 | break; |
| 603 | |
| 604 | default: |
| 605 | normal_char: |
| 606 | if (!pending_exact || pending_exact + *pending_exact + 1 != b |
| 607 | || *pending_exact == 0177 || *p == '*' || *p == '^' |
| 608 | || ((obscure_syntax & RE_BK_PLUS_QM) |
| 609 | ? *p == '\\' && (p[1] == '+' || p[1] == '?') |
| 610 | : (*p == '+' || *p == '?'))) |
| 611 | { |
| 612 | laststart = b; |
| 613 | PATPUSH (exactn); |
| 614 | pending_exact = b; |
| 615 | PATPUSH (0); |
| 616 | } |
| 617 | PATPUSH (c); |
| 618 | (*pending_exact)++; |
| 619 | } |
| 620 | } |
| 621 | |
| 622 | if (fixup_jump) |
| 623 | store_jump (fixup_jump, jump, b); |
| 624 | |
| 625 | if (stackp != stackb) goto unmatched_open; |
| 626 | |
| 627 | bufp->used = b - bufp->buffer; |
| 628 | return 0; |
| 629 | |
| 630 | invalid_pattern: |
| 631 | return "Invalid regular expression"; |
| 632 | |
| 633 | unmatched_open: |
| 634 | return "Unmatched \\("; |
| 635 | |
| 636 | unmatched_close: |
| 637 | return "Unmatched \\)"; |
| 638 | |
| 639 | end_of_pattern: |
| 640 | return "Premature end of regular expression"; |
| 641 | |
| 642 | nesting_too_deep: |
| 643 | return "Nesting too deep"; |
| 644 | |
| 645 | too_big: |
| 646 | return "Regular expression too big"; |
| 647 | |
| 648 | memory_exhausted: |
| 649 | return "Memory exhausted"; |
| 650 | } |
| 651 | |
| 652 | /* Store where `from' points a jump operation to jump to where `to' points. |
| 653 | `opcode' is the opcode to store. */ |
| 654 | |
| 655 | static void |
| 656 | store_jump (from, opcode, to) |
| 657 | char *from, *to; |
| 658 | char opcode; |
| 659 | { |
| 660 | from[0] = opcode; |
| 661 | from[1] = (to - (from + 3)) & 0377; |
| 662 | from[2] = (to - (from + 3)) >> 8; |
| 663 | } |
| 664 | |
| 665 | /* Open up space at char FROM, and insert there a jump to TO. |
| 666 | CURRENT_END gives te end of the storage no in use, |
| 667 | so we know how much data to copy up. |
| 668 | OP is the opcode of the jump to insert. |
| 669 | |
| 670 | If you call this function, you must zero out pending_exact. */ |
| 671 | |
| 672 | static void |
| 673 | insert_jump (op, from, to, current_end) |
| 674 | char op; |
| 675 | char *from, *to, *current_end; |
| 676 | { |
| 677 | register char *pto = current_end + 3; |
| 678 | register char *pfrom = current_end; |
| 679 | while (pfrom != from) |
| 680 | *--pto = *--pfrom; |
| 681 | store_jump (from, op, to); |
| 682 | } |
| 683 | \f |
| 684 | /* Given a pattern, compute a fastmap from it. |
| 685 | The fastmap records which of the (1 << BYTEWIDTH) possible characters |
| 686 | can start a string that matches the pattern. |
| 687 | This fastmap is used by re_search to skip quickly over totally implausible text. |
| 688 | |
| 689 | The caller must supply the address of a (1 << BYTEWIDTH)-byte data area |
| 690 | as bufp->fastmap. |
| 691 | The other components of bufp describe the pattern to be used. */ |
| 692 | |
| 693 | void |
| 694 | re_compile_fastmap (bufp) |
| 695 | struct re_pattern_buffer *bufp; |
| 696 | { |
| 697 | unsigned char *pattern = (unsigned char *) bufp->buffer; |
| 698 | int size = bufp->used; |
| 699 | register char *fastmap = bufp->fastmap; |
| 700 | register unsigned char *p = pattern; |
| 701 | register unsigned char *pend = pattern + size; |
| 702 | register int j; |
| 703 | unsigned char *translate = (unsigned char *) bufp->translate; |
| 704 | |
| 705 | unsigned char *stackb[NFAILURES]; |
| 706 | unsigned char **stackp = stackb; |
| 707 | |
| 708 | memset (fastmap, '\0', (1 << BYTEWIDTH)); |
| 709 | bufp->fastmap_accurate = 1; |
| 710 | bufp->can_be_null = 0; |
| 711 | |
| 712 | while (p) |
| 713 | { |
| 714 | if (p == pend) |
| 715 | { |
| 716 | bufp->can_be_null = 1; |
| 717 | break; |
| 718 | } |
| 719 | #ifdef SWITCH_ENUM_BUG |
| 720 | switch ((int) ((enum regexpcode) *p++)) |
| 721 | #else |
| 722 | switch ((enum regexpcode) *p++) |
| 723 | #endif |
| 724 | { |
| 725 | case exactn: |
| 726 | if (translate) |
| 727 | fastmap[translate[p[1]]] = 1; |
| 728 | else |
| 729 | fastmap[p[1]] = 1; |
| 730 | break; |
| 731 | |
| 732 | case begline: |
| 733 | case before_dot: |
| 734 | case at_dot: |
| 735 | case after_dot: |
| 736 | case begbuf: |
| 737 | case endbuf: |
| 738 | case wordbound: |
| 739 | case notwordbound: |
| 740 | case wordbeg: |
| 741 | case wordend: |
| 742 | continue; |
| 743 | |
| 744 | case endline: |
| 745 | if (translate) |
| 746 | fastmap[translate['\n']] = 1; |
| 747 | else |
| 748 | fastmap['\n'] = 1; |
| 749 | if (bufp->can_be_null != 1) |
| 750 | bufp->can_be_null = 2; |
| 751 | break; |
| 752 | |
| 753 | case finalize_jump: |
| 754 | case maybe_finalize_jump: |
| 755 | case jump: |
| 756 | case dummy_failure_jump: |
| 757 | bufp->can_be_null = 1; |
| 758 | j = *p++ & 0377; |
| 759 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
| 760 | p += j + 1; /* The 1 compensates for missing ++ above */ |
| 761 | if (j > 0) |
| 762 | continue; |
| 763 | /* Jump backward reached implies we just went through |
| 764 | the body of a loop and matched nothing. |
| 765 | Opcode jumped to should be an on_failure_jump. |
| 766 | Just treat it like an ordinary jump. |
| 767 | For a * loop, it has pushed its failure point already; |
| 768 | if so, discard that as redundant. */ |
| 769 | if ((enum regexpcode) *p != on_failure_jump) |
| 770 | continue; |
| 771 | p++; |
| 772 | j = *p++ & 0377; |
| 773 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
| 774 | p += j + 1; /* The 1 compensates for missing ++ above */ |
| 775 | if (stackp != stackb && *stackp == p) |
| 776 | stackp--; |
| 777 | continue; |
| 778 | |
| 779 | case on_failure_jump: |
| 780 | j = *p++ & 0377; |
| 781 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
| 782 | p++; |
| 783 | *++stackp = p + j; |
| 784 | continue; |
| 785 | |
| 786 | case start_memory: |
| 787 | case stop_memory: |
| 788 | p++; |
| 789 | continue; |
| 790 | |
| 791 | case duplicate: |
| 792 | bufp->can_be_null = 1; |
| 793 | fastmap['\n'] = 1; |
| 794 | case anychar: |
| 795 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
| 796 | if (j != '\n') |
| 797 | fastmap[j] = 1; |
| 798 | if (bufp->can_be_null) |
| 799 | return; |
| 800 | /* Don't return; check the alternative paths |
| 801 | so we can set can_be_null if appropriate. */ |
| 802 | break; |
| 803 | |
| 804 | case wordchar: |
| 805 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
| 806 | if (SYNTAX (j) == Sword) |
| 807 | fastmap[j] = 1; |
| 808 | break; |
| 809 | |
| 810 | case notwordchar: |
| 811 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
| 812 | if (SYNTAX (j) != Sword) |
| 813 | fastmap[j] = 1; |
| 814 | break; |
| 815 | |
| 816 | #ifdef emacs |
| 817 | case syntaxspec: |
| 818 | k = *p++; |
| 819 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
| 820 | if (SYNTAX (j) == (enum syntaxcode) k) |
| 821 | fastmap[j] = 1; |
| 822 | break; |
| 823 | |
| 824 | case notsyntaxspec: |
| 825 | k = *p++; |
| 826 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
| 827 | if (SYNTAX (j) != (enum syntaxcode) k) |
| 828 | fastmap[j] = 1; |
| 829 | break; |
| 830 | #endif /* emacs */ |
| 831 | |
| 832 | case charset: |
| 833 | for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) |
| 834 | if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))) |
| 835 | { |
| 836 | if (translate) |
| 837 | fastmap[translate[j]] = 1; |
| 838 | else |
| 839 | fastmap[j] = 1; |
| 840 | } |
| 841 | break; |
| 842 | |
| 843 | case charset_not: |
| 844 | /* Chars beyond end of map must be allowed */ |
| 845 | for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++) |
| 846 | if (translate) |
| 847 | fastmap[translate[j]] = 1; |
| 848 | else |
| 849 | fastmap[j] = 1; |
| 850 | |
| 851 | for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) |
| 852 | if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))) |
| 853 | { |
| 854 | if (translate) |
| 855 | fastmap[translate[j]] = 1; |
| 856 | else |
| 857 | fastmap[j] = 1; |
| 858 | } |
| 859 | break; |
| 860 | } |
| 861 | |
| 862 | /* Get here means we have successfully found the possible starting characters |
| 863 | of one path of the pattern. We need not follow this path any farther. |
| 864 | Instead, look at the next alternative remembered in the stack. */ |
| 865 | if (stackp != stackb) |
| 866 | p = *stackp--; |
| 867 | else |
| 868 | break; |
| 869 | } |
| 870 | } |
| 871 | \f |
| 872 | /* Like re_search_2, below, but only one string is specified. */ |
| 873 | |
| 874 | int |
| 875 | re_search (pbufp, string, size, startpos, range, regs) |
| 876 | struct re_pattern_buffer *pbufp; |
| 877 | char *string; |
| 878 | int size, startpos, range; |
| 879 | struct re_registers *regs; |
| 880 | { |
| 881 | return re_search_2 (pbufp, 0, 0, string, size, startpos, range, regs, size); |
| 882 | } |
| 883 | |
| 884 | /* Like re_match_2 but tries first a match starting at index STARTPOS, |
| 885 | then at STARTPOS + 1, and so on. |
| 886 | RANGE is the number of places to try before giving up. |
| 887 | If RANGE is negative, the starting positions tried are |
| 888 | STARTPOS, STARTPOS - 1, etc. |
| 889 | It is up to the caller to make sure that range is not so large |
| 890 | as to take the starting position outside of the input strings. |
| 891 | |
| 892 | The value returned is the position at which the match was found, |
| 893 | or -1 if no match was found, |
| 894 | or -2 if error (such as failure stack overflow). */ |
| 895 | |
| 896 | int |
| 897 | re_search_2 (pbufp, string1, size1, string2, size2, startpos, range, regs, mstop) |
| 898 | struct re_pattern_buffer *pbufp; |
| 899 | char *string1, *string2; |
| 900 | int size1, size2; |
| 901 | int startpos; |
| 902 | register int range; |
| 903 | struct re_registers *regs; |
| 904 | int mstop; |
| 905 | { |
| 906 | register char *fastmap = pbufp->fastmap; |
| 907 | register unsigned char *translate = (unsigned char *) pbufp->translate; |
| 908 | int total = size1 + size2; |
| 909 | int val; |
| 910 | |
| 911 | /* Update the fastmap now if not correct already */ |
| 912 | if (fastmap && !pbufp->fastmap_accurate) |
| 913 | re_compile_fastmap (pbufp); |
| 914 | |
| 915 | /* Don't waste time in a long search for a pattern |
| 916 | that says it is anchored. */ |
| 917 | if (pbufp->used > 0 && (enum regexpcode) pbufp->buffer[0] == begbuf |
| 918 | && range > 0) |
| 919 | { |
| 920 | if (startpos > 0) |
| 921 | return -1; |
| 922 | else |
| 923 | range = 1; |
| 924 | } |
| 925 | |
| 926 | while (1) |
| 927 | { |
| 928 | /* If a fastmap is supplied, skip quickly over characters |
| 929 | that cannot possibly be the start of a match. |
| 930 | Note, however, that if the pattern can possibly match |
| 931 | the null string, we must test it at each starting point |
| 932 | so that we take the first null string we get. */ |
| 933 | |
| 934 | if (fastmap && startpos < total && pbufp->can_be_null != 1) |
| 935 | { |
| 936 | if (range > 0) |
| 937 | { |
| 938 | register int lim = 0; |
| 939 | register unsigned char *p; |
| 940 | int irange = range; |
| 941 | if (startpos < size1 && startpos + range >= size1) |
| 942 | lim = range - (size1 - startpos); |
| 943 | |
| 944 | p = ((unsigned char *) |
| 945 | &(startpos >= size1 ? string2 - size1 : string1)[startpos]); |
| 946 | |
| 947 | if (translate) |
| 948 | { |
| 949 | while (range > lim && !fastmap[translate[*p++]]) |
| 950 | range--; |
| 951 | } |
| 952 | else |
| 953 | { |
| 954 | while (range > lim && !fastmap[*p++]) |
| 955 | range--; |
| 956 | } |
| 957 | startpos += irange - range; |
| 958 | } |
| 959 | else |
| 960 | { |
| 961 | register unsigned char c; |
| 962 | if (startpos >= size1) |
| 963 | c = string2[startpos - size1]; |
| 964 | else |
| 965 | c = string1[startpos]; |
| 966 | c &= 0xff; |
| 967 | if (translate ? !fastmap[translate[c]] : !fastmap[c]) |
| 968 | goto advance; |
| 969 | } |
| 970 | } |
| 971 | |
| 972 | if (range >= 0 && startpos == total |
| 973 | && fastmap && pbufp->can_be_null == 0) |
| 974 | return -1; |
| 975 | |
| 976 | val = re_match_2 (pbufp, string1, size1, string2, size2, startpos, regs, mstop); |
| 977 | if (0 <= val) |
| 978 | { |
| 979 | if (val == -2) |
| 980 | return -2; |
| 981 | return startpos; |
| 982 | } |
| 983 | |
| 984 | #ifdef C_ALLOCA |
| 985 | alloca (0); |
| 986 | #endif /* C_ALLOCA */ |
| 987 | |
| 988 | advance: |
| 989 | if (!range) break; |
| 990 | if (range > 0) range--, startpos++; else range++, startpos--; |
| 991 | } |
| 992 | return -1; |
| 993 | } |
| 994 | \f |
| 995 | #ifndef emacs /* emacs never uses this */ |
| 996 | int |
| 997 | re_match (pbufp, string, size, pos, regs) |
| 998 | struct re_pattern_buffer *pbufp; |
| 999 | char *string; |
| 1000 | int size, pos; |
| 1001 | struct re_registers *regs; |
| 1002 | { |
| 1003 | return re_match_2 (pbufp, 0, 0, string, size, pos, regs, size); |
| 1004 | } |
| 1005 | #endif /* emacs */ |
| 1006 | |
| 1007 | /* Maximum size of failure stack. Beyond this, overflow is an error. */ |
| 1008 | |
| 1009 | int re_max_failures = 2000; |
| 1010 | |
| 1011 | static int memcmp_translate(); |
| 1012 | /* Match the pattern described by PBUFP |
| 1013 | against data which is the virtual concatenation of STRING1 and STRING2. |
| 1014 | SIZE1 and SIZE2 are the sizes of the two data strings. |
| 1015 | Start the match at position POS. |
| 1016 | Do not consider matching past the position MSTOP. |
| 1017 | |
| 1018 | If pbufp->fastmap is nonzero, then it had better be up to date. |
| 1019 | |
| 1020 | The reason that the data to match are specified as two components |
| 1021 | which are to be regarded as concatenated |
| 1022 | is so this function can be used directly on the contents of an Emacs buffer. |
| 1023 | |
| 1024 | -1 is returned if there is no match. -2 is returned if there is |
| 1025 | an error (such as match stack overflow). Otherwise the value is the length |
| 1026 | of the substring which was matched. */ |
| 1027 | |
| 1028 | int |
| 1029 | re_match_2 (pbufp, string1, size1, string2, size2, pos, regs, mstop) |
| 1030 | struct re_pattern_buffer *pbufp; |
| 1031 | unsigned char *string1, *string2; |
| 1032 | int size1, size2; |
| 1033 | int pos; |
| 1034 | struct re_registers *regs; |
| 1035 | int mstop; |
| 1036 | { |
| 1037 | register unsigned char *p = (unsigned char *) pbufp->buffer; |
| 1038 | register unsigned char *pend = p + pbufp->used; |
| 1039 | /* End of first string */ |
| 1040 | unsigned char *end1; |
| 1041 | /* End of second string */ |
| 1042 | unsigned char *end2; |
| 1043 | /* Pointer just past last char to consider matching */ |
| 1044 | unsigned char *end_match_1, *end_match_2; |
| 1045 | register unsigned char *d, *dend; |
| 1046 | register int mcnt; |
| 1047 | unsigned char *translate = (unsigned char *) pbufp->translate; |
| 1048 | |
| 1049 | /* Failure point stack. Each place that can handle a failure further down the line |
| 1050 | pushes a failure point on this stack. It consists of two char *'s. |
| 1051 | The first one pushed is where to resume scanning the pattern; |
| 1052 | the second pushed is where to resume scanning the strings. |
| 1053 | If the latter is zero, the failure point is a "dummy". |
| 1054 | If a failure happens and the innermost failure point is dormant, |
| 1055 | it discards that failure point and tries the next one. */ |
| 1056 | |
| 1057 | unsigned char *initial_stack[2 * NFAILURES]; |
| 1058 | unsigned char **stackb = initial_stack; |
| 1059 | unsigned char **stackp = stackb, **stacke = &stackb[2 * NFAILURES]; |
| 1060 | |
| 1061 | /* Information on the "contents" of registers. |
| 1062 | These are pointers into the input strings; they record |
| 1063 | just what was matched (on this attempt) by some part of the pattern. |
| 1064 | The start_memory command stores the start of a register's contents |
| 1065 | and the stop_memory command stores the end. |
| 1066 | |
| 1067 | At that point, regstart[regnum] points to the first character in the register, |
| 1068 | regend[regnum] points to the first character beyond the end of the register, |
| 1069 | regstart_seg1[regnum] is true iff regstart[regnum] points into string1, |
| 1070 | and regend_seg1[regnum] is true iff regend[regnum] points into string1. */ |
| 1071 | |
| 1072 | unsigned char *regstart[RE_NREGS]; |
| 1073 | unsigned char *regend[RE_NREGS]; |
| 1074 | unsigned char regstart_seg1[RE_NREGS], regend_seg1[RE_NREGS]; |
| 1075 | |
| 1076 | /* Set up pointers to ends of strings. |
| 1077 | Don't allow the second string to be empty unless both are empty. */ |
| 1078 | if (!size2) |
| 1079 | { |
| 1080 | string2 = string1; |
| 1081 | size2 = size1; |
| 1082 | string1 = 0; |
| 1083 | size1 = 0; |
| 1084 | } |
| 1085 | end1 = string1 + size1; |
| 1086 | end2 = string2 + size2; |
| 1087 | |
| 1088 | /* Compute where to stop matching, within the two strings */ |
| 1089 | if (mstop <= size1) |
| 1090 | { |
| 1091 | end_match_1 = string1 + mstop; |
| 1092 | end_match_2 = string2; |
| 1093 | } |
| 1094 | else |
| 1095 | { |
| 1096 | end_match_1 = end1; |
| 1097 | end_match_2 = string2 + mstop - size1; |
| 1098 | } |
| 1099 | |
| 1100 | /* Initialize \) text positions to -1 |
| 1101 | to mark ones that no \( or \) has been seen for. */ |
| 1102 | |
| 1103 | for (mcnt = 0; mcnt < sizeof (regend) / sizeof (*regend); mcnt++) |
| 1104 | regend[mcnt] = (unsigned char *) -1; |
| 1105 | |
| 1106 | /* `p' scans through the pattern as `d' scans through the data. |
| 1107 | `dend' is the end of the input string that `d' points within. |
| 1108 | `d' is advanced into the following input string whenever necessary, |
| 1109 | but this happens before fetching; |
| 1110 | therefore, at the beginning of the loop, |
| 1111 | `d' can be pointing at the end of a string, |
| 1112 | but it cannot equal string2. */ |
| 1113 | |
| 1114 | if (pos <= size1) |
| 1115 | d = string1 + pos, dend = end_match_1; |
| 1116 | else |
| 1117 | d = string2 + pos - size1, dend = end_match_2; |
| 1118 | |
| 1119 | /* Write PREFETCH; just before fetching a character with *d. */ |
| 1120 | #define PREFETCH \ |
| 1121 | while (d == dend) \ |
| 1122 | { if (dend == end_match_2) goto fail; /* end of string2 => failure */ \ |
| 1123 | d = string2; /* end of string1 => advance to string2. */ \ |
| 1124 | dend = end_match_2; } |
| 1125 | |
| 1126 | /* This loop loops over pattern commands. |
| 1127 | It exits by returning from the function if match is complete, |
| 1128 | or it drops through if match fails at this starting point in the input data. */ |
| 1129 | |
| 1130 | while (1) |
| 1131 | { |
| 1132 | if (p == pend) |
| 1133 | /* End of pattern means we have succeeded! */ |
| 1134 | { |
| 1135 | /* If caller wants register contents data back, convert it to indices */ |
| 1136 | if (regs) |
| 1137 | { |
| 1138 | regs->start[0] = pos; |
| 1139 | if (dend == end_match_1) |
| 1140 | regs->end[0] = d - string1; |
| 1141 | else |
| 1142 | regs->end[0] = d - string2 + size1; |
| 1143 | for (mcnt = 1; mcnt < RE_NREGS; mcnt++) |
| 1144 | { |
| 1145 | if (regend[mcnt] == (unsigned char *) -1) |
| 1146 | { |
| 1147 | regs->start[mcnt] = -1; |
| 1148 | regs->end[mcnt] = -1; |
| 1149 | continue; |
| 1150 | } |
| 1151 | if (regstart_seg1[mcnt]) |
| 1152 | regs->start[mcnt] = regstart[mcnt] - string1; |
| 1153 | else |
| 1154 | regs->start[mcnt] = regstart[mcnt] - string2 + size1; |
| 1155 | if (regend_seg1[mcnt]) |
| 1156 | regs->end[mcnt] = regend[mcnt] - string1; |
| 1157 | else |
| 1158 | regs->end[mcnt] = regend[mcnt] - string2 + size1; |
| 1159 | } |
| 1160 | } |
| 1161 | if (dend == end_match_1) |
| 1162 | return (d - string1 - pos); |
| 1163 | else |
| 1164 | return d - string2 + size1 - pos; |
| 1165 | } |
| 1166 | |
| 1167 | /* Otherwise match next pattern command */ |
| 1168 | #ifdef SWITCH_ENUM_BUG |
| 1169 | switch ((int) ((enum regexpcode) *p++)) |
| 1170 | #else |
| 1171 | switch ((enum regexpcode) *p++) |
| 1172 | #endif |
| 1173 | { |
| 1174 | |
| 1175 | /* \( is represented by a start_memory, \) by a stop_memory. |
| 1176 | Both of those commands contain a "register number" argument. |
| 1177 | The text matched within the \( and \) is recorded under that number. |
| 1178 | Then, \<digit> turns into a `duplicate' command which |
| 1179 | is followed by the numeric value of <digit> as the register number. */ |
| 1180 | |
| 1181 | case start_memory: |
| 1182 | regstart[*p] = d; |
| 1183 | regstart_seg1[*p++] = (dend == end_match_1); |
| 1184 | break; |
| 1185 | |
| 1186 | case stop_memory: |
| 1187 | regend[*p] = d; |
| 1188 | regend_seg1[*p++] = (dend == end_match_1); |
| 1189 | break; |
| 1190 | |
| 1191 | case duplicate: |
| 1192 | { |
| 1193 | int regno = *p++; /* Get which register to match against */ |
| 1194 | register unsigned char *d2, *dend2; |
| 1195 | |
| 1196 | d2 = regstart[regno]; |
| 1197 | dend2 = ((regstart_seg1[regno] == regend_seg1[regno]) |
| 1198 | ? regend[regno] : end_match_1); |
| 1199 | while (1) |
| 1200 | { |
| 1201 | /* Advance to next segment in register contents, if necessary */ |
| 1202 | while (d2 == dend2) |
| 1203 | { |
| 1204 | if (dend2 == end_match_2) break; |
| 1205 | if (dend2 == regend[regno]) break; |
| 1206 | d2 = string2, dend2 = regend[regno]; /* end of string1 => advance to string2. */ |
| 1207 | } |
| 1208 | /* At end of register contents => success */ |
| 1209 | if (d2 == dend2) break; |
| 1210 | |
| 1211 | /* Advance to next segment in data being matched, if necessary */ |
| 1212 | PREFETCH; |
| 1213 | |
| 1214 | /* mcnt gets # consecutive chars to compare */ |
| 1215 | mcnt = dend - d; |
| 1216 | if (mcnt > dend2 - d2) |
| 1217 | mcnt = dend2 - d2; |
| 1218 | /* Compare that many; failure if mismatch, else skip them. */ |
| 1219 | if (translate ? memcmp_translate (d, d2, mcnt, translate) : memcmp (d, d2, mcnt)) |
| 1220 | goto fail; |
| 1221 | d += mcnt, d2 += mcnt; |
| 1222 | } |
| 1223 | } |
| 1224 | break; |
| 1225 | |
| 1226 | case anychar: |
| 1227 | /* fetch a data character */ |
| 1228 | PREFETCH; |
| 1229 | /* Match anything but a newline. */ |
| 1230 | if ((translate ? translate[*d++] : *d++) == '\n') |
| 1231 | goto fail; |
| 1232 | break; |
| 1233 | |
| 1234 | case charset: |
| 1235 | case charset_not: |
| 1236 | { |
| 1237 | /* Nonzero for charset_not */ |
| 1238 | int not = 0; |
| 1239 | register int c; |
| 1240 | if (*(p - 1) == (unsigned char) charset_not) |
| 1241 | not = 1; |
| 1242 | |
| 1243 | /* fetch a data character */ |
| 1244 | PREFETCH; |
| 1245 | |
| 1246 | if (translate) |
| 1247 | c = translate [*d]; |
| 1248 | else |
| 1249 | c = *d; |
| 1250 | |
| 1251 | if (c < *p * BYTEWIDTH |
| 1252 | && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) |
| 1253 | not = !not; |
| 1254 | |
| 1255 | p += 1 + *p; |
| 1256 | |
| 1257 | if (!not) goto fail; |
| 1258 | d++; |
| 1259 | break; |
| 1260 | } |
| 1261 | |
| 1262 | case begline: |
| 1263 | if (d == string1 || d[-1] == '\n') |
| 1264 | break; |
| 1265 | goto fail; |
| 1266 | |
| 1267 | case endline: |
| 1268 | if (d == end2 |
| 1269 | || (d == end1 ? (size2 == 0 || *string2 == '\n') : *d == '\n')) |
| 1270 | break; |
| 1271 | goto fail; |
| 1272 | |
| 1273 | /* "or" constructs ("|") are handled by starting each alternative |
| 1274 | with an on_failure_jump that points to the start of the next alternative. |
| 1275 | Each alternative except the last ends with a jump to the joining point. |
| 1276 | (Actually, each jump except for the last one really jumps |
| 1277 | to the following jump, because tensioning the jumps is a hassle.) */ |
| 1278 | |
| 1279 | /* The start of a stupid repeat has an on_failure_jump that points |
| 1280 | past the end of the repeat text. |
| 1281 | This makes a failure point so that, on failure to match a repetition, |
| 1282 | matching restarts past as many repetitions have been found |
| 1283 | with no way to fail and look for another one. */ |
| 1284 | |
| 1285 | /* A smart repeat is similar but loops back to the on_failure_jump |
| 1286 | so that each repetition makes another failure point. */ |
| 1287 | |
| 1288 | case on_failure_jump: |
| 1289 | if (stackp == stacke) |
| 1290 | { |
| 1291 | unsigned char **stackx; |
| 1292 | if (stacke - stackb > re_max_failures * 2) |
| 1293 | return -2; |
| 1294 | stackx = (unsigned char **) alloca (2 * (stacke - stackb) |
| 1295 | * sizeof (char *)); |
| 1296 | memcpy (stackx, stackb, (stacke - stackb) * sizeof (char *)); |
| 1297 | stackp = stackx + (stackp - stackb); |
| 1298 | stacke = stackx + 2 * (stacke - stackb); |
| 1299 | stackb = stackx; |
| 1300 | } |
| 1301 | mcnt = *p++ & 0377; |
| 1302 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
| 1303 | p++; |
| 1304 | *stackp++ = mcnt + p; |
| 1305 | *stackp++ = d; |
| 1306 | break; |
| 1307 | |
| 1308 | /* The end of a smart repeat has an maybe_finalize_jump back. |
| 1309 | Change it either to a finalize_jump or an ordinary jump. */ |
| 1310 | |
| 1311 | case maybe_finalize_jump: |
| 1312 | mcnt = *p++ & 0377; |
| 1313 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
| 1314 | p++; |
| 1315 | { |
| 1316 | register unsigned char *p2 = p; |
| 1317 | /* Compare what follows with the begining of the repeat. |
| 1318 | If we can establish that there is nothing that they would |
| 1319 | both match, we can change to finalize_jump */ |
| 1320 | while (p2 != pend |
| 1321 | && (*p2 == (unsigned char) stop_memory |
| 1322 | || *p2 == (unsigned char) start_memory)) |
| 1323 | p2++; |
| 1324 | if (p2 == pend) |
| 1325 | p[-3] = (unsigned char) finalize_jump; |
| 1326 | else if (*p2 == (unsigned char) exactn |
| 1327 | || *p2 == (unsigned char) endline) |
| 1328 | { |
| 1329 | register int c = *p2 == (unsigned char) endline ? '\n' : p2[2]; |
| 1330 | register unsigned char *p1 = p + mcnt; |
| 1331 | /* p1[0] ... p1[2] are an on_failure_jump. |
| 1332 | Examine what follows that */ |
| 1333 | if (p1[3] == (unsigned char) exactn && p1[5] != c) |
| 1334 | p[-3] = (unsigned char) finalize_jump; |
| 1335 | else if (p1[3] == (unsigned char) charset |
| 1336 | || p1[3] == (unsigned char) charset_not) |
| 1337 | { |
| 1338 | int not = p1[3] == (unsigned char) charset_not; |
| 1339 | if (c < p1[4] * BYTEWIDTH |
| 1340 | && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) |
| 1341 | not = !not; |
| 1342 | /* not is 1 if c would match */ |
| 1343 | /* That means it is not safe to finalize */ |
| 1344 | if (!not) |
| 1345 | p[-3] = (unsigned char) finalize_jump; |
| 1346 | } |
| 1347 | } |
| 1348 | } |
| 1349 | p -= 2; |
| 1350 | if (p[-1] != (unsigned char) finalize_jump) |
| 1351 | { |
| 1352 | p[-1] = (unsigned char) jump; |
| 1353 | goto nofinalize; |
| 1354 | } |
| 1355 | |
| 1356 | /* The end of a stupid repeat has a finalize-jump |
| 1357 | back to the start, where another failure point will be made |
| 1358 | which will point after all the repetitions found so far. */ |
| 1359 | |
| 1360 | case finalize_jump: |
| 1361 | stackp -= 2; |
| 1362 | |
| 1363 | case jump: |
| 1364 | nofinalize: |
| 1365 | mcnt = *p++ & 0377; |
| 1366 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
| 1367 | p += mcnt + 1; /* The 1 compensates for missing ++ above */ |
| 1368 | break; |
| 1369 | |
| 1370 | case dummy_failure_jump: |
| 1371 | if (stackp == stacke) |
| 1372 | { |
| 1373 | unsigned char **stackx |
| 1374 | = (unsigned char **) alloca (2 * (stacke - stackb) |
| 1375 | * sizeof (char *)); |
| 1376 | memcpy (stackx, stackb, (stacke - stackb) * sizeof (char *)); |
| 1377 | stackp = stackx + (stackp - stackb); |
| 1378 | stacke = stackx + 2 * (stacke - stackb); |
| 1379 | stackb = stackx; |
| 1380 | } |
| 1381 | *stackp++ = 0; |
| 1382 | *stackp++ = 0; |
| 1383 | goto nofinalize; |
| 1384 | |
| 1385 | case wordbound: |
| 1386 | if (d == string1 /* Points to first char */ |
| 1387 | || d == end2 /* Points to end */ |
| 1388 | || (d == end1 && size2 == 0)) /* Points to end */ |
| 1389 | break; |
| 1390 | if ((SYNTAX (d[-1]) == Sword) |
| 1391 | != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) |
| 1392 | break; |
| 1393 | goto fail; |
| 1394 | |
| 1395 | case notwordbound: |
| 1396 | if (d == string1 /* Points to first char */ |
| 1397 | || d == end2 /* Points to end */ |
| 1398 | || (d == end1 && size2 == 0)) /* Points to end */ |
| 1399 | goto fail; |
| 1400 | if ((SYNTAX (d[-1]) == Sword) |
| 1401 | != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) |
| 1402 | goto fail; |
| 1403 | break; |
| 1404 | |
| 1405 | case wordbeg: |
| 1406 | if (d == end2 /* Points to end */ |
| 1407 | || (d == end1 && size2 == 0) /* Points to end */ |
| 1408 | || SYNTAX (* (d == end1 ? string2 : d)) != Sword) /* Next char not a letter */ |
| 1409 | goto fail; |
| 1410 | if (d == string1 /* Points to first char */ |
| 1411 | || SYNTAX (d[-1]) != Sword) /* prev char not letter */ |
| 1412 | break; |
| 1413 | goto fail; |
| 1414 | |
| 1415 | case wordend: |
| 1416 | if (d == string1 /* Points to first char */ |
| 1417 | || SYNTAX (d[-1]) != Sword) /* prev char not letter */ |
| 1418 | goto fail; |
| 1419 | if (d == end2 /* Points to end */ |
| 1420 | || (d == end1 && size2 == 0) /* Points to end */ |
| 1421 | || SYNTAX (d == end1 ? *string2 : *d) != Sword) /* Next char not a letter */ |
| 1422 | break; |
| 1423 | goto fail; |
| 1424 | |
| 1425 | #ifdef emacs |
| 1426 | case before_dot: |
| 1427 | if (((d - string2 <= (unsigned) size2) |
| 1428 | ? d - bf_p2 : d - bf_p1) |
| 1429 | <= point) |
| 1430 | goto fail; |
| 1431 | break; |
| 1432 | |
| 1433 | case at_dot: |
| 1434 | if (((d - string2 <= (unsigned) size2) |
| 1435 | ? d - bf_p2 : d - bf_p1) |
| 1436 | == point) |
| 1437 | goto fail; |
| 1438 | break; |
| 1439 | |
| 1440 | case after_dot: |
| 1441 | if (((d - string2 <= (unsigned) size2) |
| 1442 | ? d - bf_p2 : d - bf_p1) |
| 1443 | >= point) |
| 1444 | goto fail; |
| 1445 | break; |
| 1446 | |
| 1447 | case wordchar: |
| 1448 | mcnt = (int) Sword; |
| 1449 | goto matchsyntax; |
| 1450 | |
| 1451 | case syntaxspec: |
| 1452 | mcnt = *p++; |
| 1453 | matchsyntax: |
| 1454 | PREFETCH; |
| 1455 | if (SYNTAX (*d++) != (enum syntaxcode) mcnt) goto fail; |
| 1456 | break; |
| 1457 | |
| 1458 | case notwordchar: |
| 1459 | mcnt = (int) Sword; |
| 1460 | goto matchnotsyntax; |
| 1461 | |
| 1462 | case notsyntaxspec: |
| 1463 | mcnt = *p++; |
| 1464 | matchnotsyntax: |
| 1465 | PREFETCH; |
| 1466 | if (SYNTAX (*d++) == (enum syntaxcode) mcnt) goto fail; |
| 1467 | break; |
| 1468 | #else |
| 1469 | case wordchar: |
| 1470 | PREFETCH; |
| 1471 | if (SYNTAX (*d++) == 0) goto fail; |
| 1472 | break; |
| 1473 | |
| 1474 | case notwordchar: |
| 1475 | PREFETCH; |
| 1476 | if (SYNTAX (*d++) != 0) goto fail; |
| 1477 | break; |
| 1478 | #endif /* not emacs */ |
| 1479 | |
| 1480 | case begbuf: |
| 1481 | if (d == string1) /* Note, d cannot equal string2 */ |
| 1482 | break; /* unless string1 == string2. */ |
| 1483 | goto fail; |
| 1484 | |
| 1485 | case endbuf: |
| 1486 | if (d == end2 || (d == end1 && size2 == 0)) |
| 1487 | break; |
| 1488 | goto fail; |
| 1489 | |
| 1490 | case exactn: |
| 1491 | /* Match the next few pattern characters exactly. |
| 1492 | mcnt is how many characters to match. */ |
| 1493 | mcnt = *p++; |
| 1494 | if (translate) |
| 1495 | { |
| 1496 | do |
| 1497 | { |
| 1498 | PREFETCH; |
| 1499 | if (translate[*d++] != *p++) goto fail; |
| 1500 | } |
| 1501 | while (--mcnt); |
| 1502 | } |
| 1503 | else |
| 1504 | { |
| 1505 | do |
| 1506 | { |
| 1507 | PREFETCH; |
| 1508 | if (*d++ != *p++) goto fail; |
| 1509 | } |
| 1510 | while (--mcnt); |
| 1511 | } |
| 1512 | break; |
| 1513 | } |
| 1514 | continue; /* Successfully matched one pattern command; keep matching */ |
| 1515 | |
| 1516 | /* Jump here if any matching operation fails. */ |
| 1517 | fail: |
| 1518 | if (stackp != stackb) |
| 1519 | /* A restart point is known. Restart there and pop it. */ |
| 1520 | { |
| 1521 | if (!stackp[-2]) |
| 1522 | { /* If innermost failure point is dormant, flush it and keep looking */ |
| 1523 | stackp -= 2; |
| 1524 | goto fail; |
| 1525 | } |
| 1526 | d = *--stackp; |
| 1527 | p = *--stackp; |
| 1528 | if (d >= string1 && d <= end1) |
| 1529 | dend = end_match_1; |
| 1530 | } |
| 1531 | else break; /* Matching at this starting point really fails! */ |
| 1532 | } |
| 1533 | return -1; /* Failure to match */ |
| 1534 | } |
| 1535 | |
| 1536 | static int |
| 1537 | memcmp_translate (s1, s2, len, translate) |
| 1538 | unsigned char *s1, *s2; |
| 1539 | register int len; |
| 1540 | unsigned char *translate; |
| 1541 | { |
| 1542 | register unsigned char *p1 = s1, *p2 = s2; |
| 1543 | while (len) |
| 1544 | { |
| 1545 | if (translate [*p1++] != translate [*p2++]) return 1; |
| 1546 | len--; |
| 1547 | } |
| 1548 | return 0; |
| 1549 | } |
| 1550 | \f |
| 1551 | /* Entry points compatible with bsd4.2 regex library */ |
| 1552 | |
| 1553 | #ifndef emacs |
| 1554 | |
| 1555 | static struct re_pattern_buffer re_comp_buf; |
| 1556 | |
| 1557 | char * |
| 1558 | re_comp (s) |
| 1559 | char *s; |
| 1560 | { |
| 1561 | if (!s) |
| 1562 | { |
| 1563 | if (!re_comp_buf.buffer) |
| 1564 | return "No previous regular expression"; |
| 1565 | return 0; |
| 1566 | } |
| 1567 | |
| 1568 | if (!re_comp_buf.buffer) |
| 1569 | { |
| 1570 | if (!(re_comp_buf.buffer = (char *) malloc (200))) |
| 1571 | return "Memory exhausted"; |
| 1572 | re_comp_buf.allocated = 200; |
| 1573 | if (!(re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH))) |
| 1574 | return "Memory exhausted"; |
| 1575 | } |
| 1576 | return re_compile_pattern (s, strlen (s), &re_comp_buf); |
| 1577 | } |
| 1578 | |
| 1579 | int |
| 1580 | re_exec (s) |
| 1581 | char *s; |
| 1582 | { |
| 1583 | int len = strlen (s); |
| 1584 | return 0 <= re_search (&re_comp_buf, s, len, 0, len, 0); |
| 1585 | } |
| 1586 | |
| 1587 | #endif /* emacs */ |
| 1588 | \f |
| 1589 | #ifdef test |
| 1590 | |
| 1591 | #include <stdio.h> |
| 1592 | |
| 1593 | /* Indexed by a character, gives the upper case equivalent of the character */ |
| 1594 | |
| 1595 | static char upcase[0400] = |
| 1596 | { 000, 001, 002, 003, 004, 005, 006, 007, |
| 1597 | 010, 011, 012, 013, 014, 015, 016, 017, |
| 1598 | 020, 021, 022, 023, 024, 025, 026, 027, |
| 1599 | 030, 031, 032, 033, 034, 035, 036, 037, |
| 1600 | 040, 041, 042, 043, 044, 045, 046, 047, |
| 1601 | 050, 051, 052, 053, 054, 055, 056, 057, |
| 1602 | 060, 061, 062, 063, 064, 065, 066, 067, |
| 1603 | 070, 071, 072, 073, 074, 075, 076, 077, |
| 1604 | 0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107, |
| 1605 | 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, |
| 1606 | 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, |
| 1607 | 0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137, |
| 1608 | 0140, 0101, 0102, 0103, 0104, 0105, 0106, 0107, |
| 1609 | 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, |
| 1610 | 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, |
| 1611 | 0130, 0131, 0132, 0173, 0174, 0175, 0176, 0177, |
| 1612 | 0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207, |
| 1613 | 0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217, |
| 1614 | 0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227, |
| 1615 | 0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237, |
| 1616 | 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247, |
| 1617 | 0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257, |
| 1618 | 0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267, |
| 1619 | 0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277, |
| 1620 | 0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307, |
| 1621 | 0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317, |
| 1622 | 0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327, |
| 1623 | 0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337, |
| 1624 | 0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347, |
| 1625 | 0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357, |
| 1626 | 0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367, |
| 1627 | 0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377 |
| 1628 | }; |
| 1629 | |
| 1630 | main (argc, argv) |
| 1631 | int argc; |
| 1632 | char **argv; |
| 1633 | { |
| 1634 | char pat[80]; |
| 1635 | struct re_pattern_buffer buf; |
| 1636 | int i; |
| 1637 | char c; |
| 1638 | char fastmap[(1 << BYTEWIDTH)]; |
| 1639 | |
| 1640 | /* Allow a command argument to specify the style of syntax. */ |
| 1641 | if (argc > 1) |
| 1642 | obscure_syntax = atoi (argv[1]); |
| 1643 | |
| 1644 | buf.allocated = 40; |
| 1645 | buf.buffer = (char *) malloc (buf.allocated); |
| 1646 | buf.fastmap = fastmap; |
| 1647 | buf.translate = upcase; |
| 1648 | |
| 1649 | while (1) |
| 1650 | { |
| 1651 | gets (pat); |
| 1652 | |
| 1653 | if (*pat) |
| 1654 | { |
| 1655 | re_compile_pattern (pat, strlen(pat), &buf); |
| 1656 | |
| 1657 | for (i = 0; i < buf.used; i++) |
| 1658 | printchar (buf.buffer[i]); |
| 1659 | |
| 1660 | putchar ('\n'); |
| 1661 | |
| 1662 | printf ("%d allocated, %d used.\n", buf.allocated, buf.used); |
| 1663 | |
| 1664 | re_compile_fastmap (&buf); |
| 1665 | printf ("Allowed by fastmap: "); |
| 1666 | for (i = 0; i < (1 << BYTEWIDTH); i++) |
| 1667 | if (fastmap[i]) printchar (i); |
| 1668 | putchar ('\n'); |
| 1669 | } |
| 1670 | |
| 1671 | gets (pat); /* Now read the string to match against */ |
| 1672 | |
| 1673 | i = re_match (&buf, pat, strlen (pat), 0, 0); |
| 1674 | printf ("Match value %d.\n", i); |
| 1675 | } |
| 1676 | } |
| 1677 | |
| 1678 | #ifdef NOTDEF |
| 1679 | print_buf (bufp) |
| 1680 | struct re_pattern_buffer *bufp; |
| 1681 | { |
| 1682 | int i; |
| 1683 | |
| 1684 | printf ("buf is :\n----------------\n"); |
| 1685 | for (i = 0; i < bufp->used; i++) |
| 1686 | printchar (bufp->buffer[i]); |
| 1687 | |
| 1688 | printf ("\n%d allocated, %d used.\n", bufp->allocated, bufp->used); |
| 1689 | |
| 1690 | printf ("Allowed by fastmap: "); |
| 1691 | for (i = 0; i < (1 << BYTEWIDTH); i++) |
| 1692 | if (bufp->fastmap[i]) |
| 1693 | printchar (i); |
| 1694 | printf ("\nAllowed by translate: "); |
| 1695 | if (bufp->translate) |
| 1696 | for (i = 0; i < (1 << BYTEWIDTH); i++) |
| 1697 | if (bufp->translate[i]) |
| 1698 | printchar (i); |
| 1699 | printf ("\nfastmap is%s accurate\n", bufp->fastmap_accurate ? "" : "n't"); |
| 1700 | printf ("can %s be null\n----------", bufp->can_be_null ? "" : "not"); |
| 1701 | } |
| 1702 | #endif |
| 1703 | |
| 1704 | printchar (c) |
| 1705 | char c; |
| 1706 | { |
| 1707 | if (c < 041 || c >= 0177) |
| 1708 | { |
| 1709 | putchar ('\\'); |
| 1710 | putchar (((c >> 6) & 3) + '0'); |
| 1711 | putchar (((c >> 3) & 7) + '0'); |
| 1712 | putchar ((c & 7) + '0'); |
| 1713 | } |
| 1714 | else |
| 1715 | putchar (c); |
| 1716 | } |
| 1717 | |
| 1718 | error (string) |
| 1719 | char *string; |
| 1720 | { |
| 1721 | puts (string); |
| 1722 | exit (1); |
| 1723 | } |
| 1724 | |
| 1725 | #endif /* test */ |