1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621
|
/*
* re.c - compile regular expressions.
*/
/*
* Copyright (C) 1991-2017 the Free Software Foundation, Inc.
*
* This file is part of GAWK, the GNU implementation of the
* AWK Programming Language.
*
* GAWK is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GAWK is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "awk.h"
#include "localeinfo.h"
static reg_syntax_t syn;
static void check_bracket_exp(char *s, size_t len);
const char *regexflags2str(int flags);
static struct localeinfo localeinfo;
/* make_regexp --- generate compiled regular expressions */
Regexp *
make_regexp(const char *s, size_t len, bool ignorecase, bool dfa, bool canfatal)
{
static char metas[] = ".*+(){}[]|?^$\\";
Regexp *rp;
const char *rerr;
const char *src = s;
static char *buf = NULL;
static size_t buflen;
const char *end = s + len;
char *dest;
int c, c2;
static bool first = true;
static bool no_dfa = false;
int i;
static struct dfa* dfaregs[2] = { NULL, NULL };
/*
* The number of bytes in the current multibyte character.
* It is 0, when the current character is a singlebyte character.
*/
size_t is_multibyte = 0;
mbstate_t mbs;
memset(&mbs, 0, sizeof(mbstate_t)); /* Initialize. */
if (first) {
/* for debugging and testing */
no_dfa = (getenv("GAWK_NO_DFA") != NULL);
/* don't set first to false here, we do it below */
}
/* always check */
check_bracket_exp((char *) s, len);
/* Handle escaped characters first. */
/*
* Build a copy of the string (in buf) with the
* escaped characters translated, and generate the regex
* from that.
*/
if (buf == NULL) {
emalloc(buf, char *, len + 1, "make_regexp");
buflen = len;
} else if (len > buflen) {
erealloc(buf, char *, len + 1, "make_regexp");
buflen = len;
}
dest = buf;
while (src < end) {
if (gawk_mb_cur_max > 1 && ! is_multibyte) {
/* The previous byte is a singlebyte character, or last byte
of a multibyte character. We check the next character. */
is_multibyte = mbrlen(src, end - src, &mbs);
if ( is_multibyte == 1
|| is_multibyte == (size_t) -1
|| is_multibyte == (size_t) -2
|| is_multibyte == 0) {
/* We treat it as a single-byte character. */
is_multibyte = 0;
}
}
/* We skip multibyte character, since it must not be a special
character. */
if ((gawk_mb_cur_max == 1 || ! is_multibyte) &&
(*src == '\\')) {
c = *++src;
switch (c) {
case 'a':
case 'b':
case 'f':
case 'n':
case 'r':
case 't':
case 'v':
case 'x':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
c2 = parse_escape(&src);
if (c2 < 0)
cant_happen();
/*
* Unix awk treats octal (and hex?) chars
* literally in re's, so escape regexp
* metacharacters.
*/
if (do_traditional
&& ! do_posix
&& (isdigit(c) || c == 'x')
&& strchr("()|*+?.^$\\[]", c2) != NULL)
*dest++ = '\\';
*dest++ = (char) c2;
break;
case '8':
case '9': /* a\9b not valid */
*dest++ = c;
src++;
break;
case 'y': /* normally \b */
/* gnu regex op */
if (! do_traditional) {
*dest++ = '\\';
*dest++ = 'b';
src++;
break;
}
/* else, fall through */
default:
*dest++ = '\\';
*dest++ = (char) c;
src++;
break;
} /* switch */
} else {
c = *src;
*dest++ = *src++; /* not '\\' */
}
if (gawk_mb_cur_max > 1 && is_multibyte)
is_multibyte--;
} /* while */
*dest = '\0';
len = dest - buf;
ezalloc(rp, Regexp *, sizeof(*rp), "make_regexp");
rp->pat.allocated = 0; /* regex will allocate the buffer */
emalloc(rp->pat.fastmap, char *, 256, "make_regexp");
/*
* Lo these many years ago, had I known what a P.I.T.A. IGNORECASE
* was going to turn out to be, I wouldn't have bothered with it.
*
* In the case where we have a multibyte character set, we have no
* choice but to use RE_ICASE, since the casetable is for single-byte
* character sets only.
*
* On the other hand, if we do have a single-byte character set,
* using the casetable should give a performance improvement, since
* it's computed only once, not each time a regex is compiled. We
* also think it's probably better for portability. See the
* discussion by the definition of casetable[] in eval.c.
*/
ignorecase = !! ignorecase; /* force to 1 or 0 */
if (ignorecase) {
if (gawk_mb_cur_max > 1) {
syn |= RE_ICASE;
rp->pat.translate = NULL;
} else {
syn &= ~RE_ICASE;
rp->pat.translate = (RE_TRANSLATE_TYPE) casetable;
}
} else {
rp->pat.translate = NULL;
syn &= ~RE_ICASE;
}
/* initialize dfas to hold syntax */
if (first) {
first = false;
dfaregs[0] = dfaalloc();
dfaregs[1] = dfaalloc();
dfasyntax(dfaregs[0], & localeinfo, syn, DFA_ANCHOR);
dfasyntax(dfaregs[1], & localeinfo, syn | RE_ICASE, DFA_ANCHOR);
}
re_set_syntax(syn);
if ((rerr = re_compile_pattern(buf, len, &(rp->pat))) != NULL) {
refree(rp);
if (! canfatal) {
/* rerr already gettextized inside regex routines */
error("%s: /%s/", rerr, buf);
return NULL;
}
fatal("%s: /%s/", rerr, buf);
}
/* gack. this must be done *after* re_compile_pattern */
rp->pat.newline_anchor = false; /* don't get \n in middle of string */
if (dfa && ! no_dfa) {
rp->dfareg = dfaalloc();
dfacopysyntax(rp->dfareg, dfaregs[ignorecase]);
dfacomp(buf, len, rp->dfareg, true);
} else
rp->dfareg = NULL;
/* Additional flags that help with RS as regexp. */
for (i = 0; i < len; i++) {
if (strchr(metas, buf[i]) != NULL) {
rp->has_meta = true;
break;
}
}
for (i = len - 1; i >= 0; i--) {
if (strchr("*+|?", buf[i]) != NULL) {
rp->maybe_long = true;
break;
}
}
return rp;
}
/* research --- do a regexp search. use dfa if possible */
int
research(Regexp *rp, char *str, int start,
size_t len, int flags)
{
const char *ret = str;
bool try_backref = false;
int need_start;
int no_bol;
int res;
need_start = ((flags & RE_NEED_START) != 0);
no_bol = ((flags & RE_NO_BOL) != 0);
if (no_bol)
rp->pat.not_bol = 1;
/*
* Always do dfa search if can; if it fails, then even if
* need_start is true, we won't bother with the regex search.
*
* The dfa matcher doesn't have a no_bol flag, so don't bother
* trying it in that case.
*
* 7/2008: Skip the dfa matcher if need_start. The dfa matcher
* has bugs in certain multibyte cases and it's too difficult
* to try to special case things.
* 7/2017: Apparently there are some cases where DFA gets
* stuck, even in the C locale, so we use dfa only if not need_start.
*
* Should that issue ever get resolved, note this comment:
*
* 7/2016: The dfa matcher can't handle a case where searching
* starts in the middle of a string, so don't bother trying it
* in that case.
* if (rp->dfa && ! no_bol && start == 0) ...
*/
if (rp->dfareg != NULL && ! no_bol && ! need_start) {
struct dfa *superset = dfasuperset(rp->dfareg);
if (superset)
ret = dfaexec(superset, str+start, str+start+len,
true, NULL, NULL);
if (ret && (! need_start
|| (! superset && dfaisfast(rp->dfareg))))
ret = dfaexec(rp->dfareg, str+start, str+start+len,
true, NULL, &try_backref);
}
if (ret) {
if ( rp->dfareg == NULL
|| start != 0
|| no_bol
|| need_start
|| try_backref) {
/*
* Passing NULL as last arg speeds up search for cases
* where we don't need the start/end info.
*/
res = re_search(&(rp->pat), str, start+len,
start, len, need_start ? &(rp->regs) : NULL);
} else
res = 1;
} else
res = -1;
rp->pat.not_bol = 0;
return res;
}
/* refree --- free up the dynamic memory used by a compiled regexp */
void
refree(Regexp *rp)
{
if (rp == NULL)
return;
rp->pat.translate = NULL;
regfree(& rp->pat);
if (rp->regs.start)
free(rp->regs.start);
if (rp->regs.end)
free(rp->regs.end);
if (rp->dfareg != NULL) {
dfafree(rp->dfareg);
free(rp->dfareg);
}
efree(rp);
}
/* dfaerror --- print an error message for the dfa routines */
void
dfaerror(const char *s)
{
fatal("%s", s);
exit(EXIT_FATAL); /* for DJGPP */
}
/* re_update --- recompile a dynamic regexp */
Regexp *
re_update(NODE *t)
{
NODE *t1;
if (t->type == Node_val && (t->flags & REGEX) != 0)
return t->typed_re->re_reg[IGNORECASE];
if ((t->re_flags & CONSTANT) != 0) {
/* it's a constant, so just return it as is */
assert(t->type == Node_regex);
return t->re_reg[IGNORECASE];
}
t1 = t->re_exp;
if (t->re_text != NULL) {
/* if contents haven't changed, just return it */
if (cmp_nodes(t->re_text, t1, true) == 0)
return t->re_reg[IGNORECASE];
/* things changed, fall through to recompile */
unref(t->re_text);
}
/* get fresh copy of the text of the regexp */
t->re_text = dupnode(t1);
/* text changed */
/* free old */
if (t->re_reg[0] != NULL)
refree(t->re_reg[0]);
if (t->re_reg[1] != NULL)
refree(t->re_reg[1]);
if (t->re_cnt > 0)
t->re_cnt++;
if (t->re_cnt > 10)
t->re_cnt = 0;
if (t->re_text == NULL) {
/* reset regexp text if needed */
t1 = t->re_exp;
unref(t->re_text);
t->re_text = dupnode(t1);
}
/* compile it */
t->re_reg[0] = make_regexp(t->re_text->stptr, t->re_text->stlen,
false, t->re_cnt, true);
t->re_reg[1] = make_regexp(t->re_text->stptr, t->re_text->stlen,
true, t->re_cnt, true);
return t->re_reg[IGNORECASE];
}
/* resetup --- choose what kind of regexps we match */
void
resetup()
{
// init localeinfo for dfa
init_localeinfo(& localeinfo);
/*
* Syntax bits: _that_ is yet another mind trip. Recreational drugs
* are helpful for recovering from the experience.
*
* Aharon Robbins <arnold@skeeve.com>
* Sun, 21 Oct 2007 23:55:33 +0200
*/
if (do_posix)
syn = RE_SYNTAX_POSIX_AWK; /* strict POSIX re's */
else if (do_traditional)
syn = RE_SYNTAX_AWK; /* traditional Unix awk re's */
else
syn = RE_SYNTAX_GNU_AWK; /* POSIX re's + GNU ops */
/*
* Interval expressions are now on by default, as POSIX is
* wide-spread enough that people want it. The do_intervals
* variable remains for use with --traditional.
*/
if (do_intervals)
syn |= RE_INTERVALS | RE_INVALID_INTERVAL_ORD | RE_NO_BK_BRACES;
(void) re_set_syntax(syn);
}
/* using_utf8 --- are we using utf8 */
bool
using_utf8(void)
{
return localeinfo.using_utf8;
}
/* reisstring --- return true if the RE match is a simple string match */
int
reisstring(const char *text, size_t len, Regexp *re, const char *buf)
{
int res;
const char *matched;
/* simple checking for meta characters in re */
if (re->has_meta)
return false; /* give up early, can't be string match */
/* make accessable to gdb */
matched = &buf[RESTART(re, buf)];
res = (memcmp(text, matched, len) == 0);
return res;
}
/* reflags2str --- make a regex flags value readable */
const char *
reflags2str(int flagval)
{
static const struct flagtab values[] = {
{ RE_BACKSLASH_ESCAPE_IN_LISTS, "RE_BACKSLASH_ESCAPE_IN_LISTS" },
{ RE_BK_PLUS_QM, "RE_BK_PLUS_QM" },
{ RE_CHAR_CLASSES, "RE_CHAR_CLASSES" },
{ RE_CONTEXT_INDEP_ANCHORS, "RE_CONTEXT_INDEP_ANCHORS" },
{ RE_CONTEXT_INDEP_OPS, "RE_CONTEXT_INDEP_OPS" },
{ RE_CONTEXT_INVALID_OPS, "RE_CONTEXT_INVALID_OPS" },
{ RE_DOT_NEWLINE, "RE_DOT_NEWLINE" },
{ RE_DOT_NOT_NULL, "RE_DOT_NOT_NULL" },
{ RE_HAT_LISTS_NOT_NEWLINE, "RE_HAT_LISTS_NOT_NEWLINE" },
{ RE_INTERVALS, "RE_INTERVALS" },
{ RE_LIMITED_OPS, "RE_LIMITED_OPS" },
{ RE_NEWLINE_ALT, "RE_NEWLINE_ALT" },
{ RE_NO_BK_BRACES, "RE_NO_BK_BRACES" },
{ RE_NO_BK_PARENS, "RE_NO_BK_PARENS" },
{ RE_NO_BK_REFS, "RE_NO_BK_REFS" },
{ RE_NO_BK_VBAR, "RE_NO_BK_VBAR" },
{ RE_NO_EMPTY_RANGES, "RE_NO_EMPTY_RANGES" },
{ RE_UNMATCHED_RIGHT_PAREN_ORD, "RE_UNMATCHED_RIGHT_PAREN_ORD" },
{ RE_NO_POSIX_BACKTRACKING, "RE_NO_POSIX_BACKTRACKING" },
{ RE_NO_GNU_OPS, "RE_NO_GNU_OPS" },
{ RE_INVALID_INTERVAL_ORD, "RE_INVALID_INTERVAL_ORD" },
{ RE_ICASE, "RE_ICASE" },
{ RE_CARET_ANCHORS_HERE, "RE_CARET_ANCHORS_HERE" },
{ RE_CONTEXT_INVALID_DUP, "RE_CONTEXT_INVALID_DUP" },
{ RE_NO_SUB, "RE_NO_SUB" },
{ 0, NULL },
};
if (flagval == RE_SYNTAX_EMACS) /* == 0 */
return "RE_SYNTAX_EMACS";
return genflags2str(flagval, values);
}
/*
* dfawarn() is called by the dfa routines whenever a regex is compiled
* must supply a dfawarn.
*/
void
dfawarn(const char *dfa_warning)
{
/*
* This routine does nothing, since gawk does its own
* (better) check for bad [[:foo:]] syntax.
*/
}
/* check_bracket_exp --- look for /[:space:]/ that should be /[[:space:]]/ */
static void
check_bracket_exp(char *s, size_t length)
{
static struct reclass {
const char *name;
size_t len;
bool warned;
} classes[] = {
/*
* Ordered by what we hope is frequency,
* since it's linear searched.
*/
{ "[:alpha:]", 9, false },
{ "[:digit:]", 9, false },
{ "[:alnum:]", 9, false },
{ "[:upper:]", 9, false },
{ "[:lower:]", 9, false },
{ "[:space:]", 9, false },
{ "[:xdigit:]", 10, false },
{ "[:punct:]", 9, false },
{ "[:print:]", 9, false },
{ "[:graph:]", 9, false },
{ "[:cntrl:]", 9, false },
{ "[:blank:]", 9, false },
{ NULL, 0 }
};
int i;
bool found = false;
char save;
char *sp, *sp2, *end;
int len;
int count = 0;
if (length == 0)
return;
end = s + length;
save = s[length];
s[length] = '\0';
sp = s;
again:
sp = sp2 = memchr(sp, '[', (end - sp));
if (sp == NULL)
goto done;
for (count++, sp++; *sp != '\0'; sp++) {
if (*sp == '[')
count++;
/*
* ] as first char after open [ is skipped
* \] is skipped
* [^]] is skipped
*/
if (*sp == ']' && sp > sp2) {
if (sp[-1] != '['
&& sp[-1] != '\\')
;
else if ((sp - sp2) >= 2
&& sp[-1] == '^' && sp[-2] == '[')
;
else
count--;
}
if (count == 0) {
sp++; /* skip past ']' */
break;
}
}
if (count > 0) { /* bad regex, give up */
goto done;
}
/* sp2 has start */
for (i = 0; classes[i].name != NULL; i++) {
if (classes[i].warned)
continue;
len = classes[i].len;
if ( len == (sp - sp2)
&& memcmp(sp2, classes[i].name, len) == 0) {
found = true;
break;
}
}
if (found && ! classes[i].warned) {
warning(_("regexp component `%.*s' should probably be `[%.*s]'"),
len, sp2, len, sp2);
classes[i].warned = true;
}
if (sp < end) {
found = false;
goto again;
}
done:
s[length] = save;
}
|