5 * One Ring to rule them all, One Ring to find them
7 * [p.v of _The Lord of the Rings_, opening poem]
8 * [p.50 of _The Lord of the Rings_, I/iii: "The Shadow of the Past"]
9 * [p.254 of _The Lord of the Rings_, II/ii: "The Council of Elrond"]
12 /* This file contains functions for executing a regular expression. See
13 * also regcomp.c which funnily enough, contains functions for compiling
14 * a regular expression.
16 * This file is also copied at build time to ext/re/re_exec.c, where
17 * it's built with -DPERL_EXT_RE_BUILD -DPERL_EXT_RE_DEBUG -DPERL_EXT.
18 * This causes the main functions to be compiled under new names and with
19 * debugging support added, which makes "use re 'debug'" work.
22 /* NOTE: this is derived from Henry Spencer's regexp code, and should not
23 * confused with the original package (see point 3 below). Thanks, Henry!
26 /* Additional note: this code is very heavily munged from Henry's version
27 * in places. In some spots I've traded clarity for efficiency, so don't
28 * blame Henry for some of the lack of readability.
31 /* The names of the functions have been changed from regcomp and
32 * regexec to pregcomp and pregexec in order to avoid conflicts
33 * with the POSIX routines of the same names.
36 #ifdef PERL_EXT_RE_BUILD
40 #define B_ON_NON_UTF8_LOCALE_IS_WRONG \
41 "Use of \\b{} or \\B{} for non-UTF-8 locale is wrong. Assuming a UTF-8 locale"
44 * pregcomp and pregexec -- regsub and regerror are not used in perl
46 * Copyright (c) 1986 by University of Toronto.
47 * Written by Henry Spencer. Not derived from licensed software.
49 * Permission is granted to anyone to use this software for any
50 * purpose on any computer system, and to redistribute it freely,
51 * subject to the following restrictions:
53 * 1. The author is not responsible for the consequences of use of
54 * this software, no matter how awful, even if they arise
57 * 2. The origin of this software must not be misrepresented, either
58 * by explicit claim or by omission.
60 * 3. Altered versions must be plainly marked as such, and must not
61 * be misrepresented as being the original software.
63 **** Alterations to Henry's code are...
65 **** Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
66 **** 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
67 **** by Larry Wall and others
69 **** You may distribute under the terms of either the GNU General Public
70 **** License or the Artistic License, as specified in the README file.
72 * Beware that some of this code is subtly aware of the way operator
73 * precedence is structured in regular expressions. Serious changes in
74 * regular-expression syntax might require a total rethink.
77 #define PERL_IN_REGEXEC_C
80 #ifdef PERL_IN_XSUB_RE
86 #include "inline_invlist.c"
87 #include "unicode_constants.h"
90 /* At least one required character in the target string is expressible only in
92 static const char* const non_utf8_target_but_utf8_required
93 = "Can't match, because target string needs to be in UTF-8\n";
96 #define NON_UTF8_TARGET_BUT_UTF8_REQUIRED(target) STMT_START { \
97 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s", non_utf8_target_but_utf8_required));\
101 #define HAS_NONLATIN1_FOLD_CLOSURE(i) _HAS_NONLATIN1_FOLD_CLOSURE_ONLY_FOR_USE_BY_REGCOMP_DOT_C_AND_REGEXEC_DOT_C(i)
104 #define STATIC static
107 /* Valid only for non-utf8 strings: avoids the reginclass
108 * call if there are no complications: i.e., if everything matchable is
109 * straight forward in the bitmap */
110 #define REGINCLASS(prog,p,c) (ANYOF_FLAGS(p) ? reginclass(prog,p,c,c+1,0) \
111 : ANYOF_BITMAP_TEST(p,*(c)))
117 #define CHR_SVLEN(sv) (utf8_target ? sv_len_utf8(sv) : SvCUR(sv))
118 #define CHR_DIST(a,b) (reginfo->is_utf8_target ? utf8_distance(a,b) : a - b)
120 #define HOPc(pos,off) \
121 (char *)(reginfo->is_utf8_target \
122 ? reghop3((U8*)pos, off, \
123 (U8*)(off >= 0 ? reginfo->strend : reginfo->strbeg)) \
126 #define HOPBACKc(pos, off) \
127 (char*)(reginfo->is_utf8_target \
128 ? reghopmaybe3((U8*)pos, -off, (U8*)(reginfo->strbeg)) \
129 : (pos - off >= reginfo->strbeg) \
133 #define HOP3(pos,off,lim) (reginfo->is_utf8_target ? reghop3((U8*)(pos), off, (U8*)(lim)) : (U8*)(pos + off))
134 #define HOP3c(pos,off,lim) ((char*)HOP3(pos,off,lim))
136 /* lim must be +ve. Returns NULL on overshoot */
137 #define HOPMAYBE3(pos,off,lim) \
138 (reginfo->is_utf8_target \
139 ? reghopmaybe3((U8*)pos, off, (U8*)(lim)) \
140 : ((U8*)pos + off <= lim) \
144 /* like HOP3, but limits the result to <= lim even for the non-utf8 case.
145 * off must be >=0; args should be vars rather than expressions */
146 #define HOP3lim(pos,off,lim) (reginfo->is_utf8_target \
147 ? reghop3((U8*)(pos), off, (U8*)(lim)) \
148 : (U8*)((pos + off) > lim ? lim : (pos + off)))
150 #define HOP4(pos,off,llim, rlim) (reginfo->is_utf8_target \
151 ? reghop4((U8*)(pos), off, (U8*)(llim), (U8*)(rlim)) \
153 #define HOP4c(pos,off,llim, rlim) ((char*)HOP4(pos,off,llim, rlim))
155 #define NEXTCHR_EOS -10 /* nextchr has fallen off the end */
156 #define NEXTCHR_IS_EOS (nextchr < 0)
158 #define SET_nextchr \
159 nextchr = ((locinput < reginfo->strend) ? UCHARAT(locinput) : NEXTCHR_EOS)
161 #define SET_locinput(p) \
166 #define LOAD_UTF8_CHARCLASS(swash_ptr, property_name, invlist) STMT_START { \
168 U8 flags = _CORE_SWASH_INIT_ACCEPT_INVLIST; \
169 swash_ptr = _core_swash_init("utf8", property_name, &PL_sv_undef, \
170 1, 0, invlist, &flags); \
175 /* If in debug mode, we test that a known character properly matches */
177 # define LOAD_UTF8_CHARCLASS_DEBUG_TEST(swash_ptr, \
180 utf8_char_in_property) \
181 LOAD_UTF8_CHARCLASS(swash_ptr, property_name, invlist); \
182 assert(swash_fetch(swash_ptr, (U8 *) utf8_char_in_property, TRUE));
184 # define LOAD_UTF8_CHARCLASS_DEBUG_TEST(swash_ptr, \
187 utf8_char_in_property) \
188 LOAD_UTF8_CHARCLASS(swash_ptr, property_name, invlist)
191 #define LOAD_UTF8_CHARCLASS_ALNUM() LOAD_UTF8_CHARCLASS_DEBUG_TEST( \
192 PL_utf8_swash_ptrs[_CC_WORDCHAR], \
194 PL_XPosix_ptrs[_CC_WORDCHAR], \
195 LATIN_CAPITAL_LETTER_SHARP_S_UTF8);
197 #define PLACEHOLDER /* Something for the preprocessor to grab onto */
198 /* TODO: Combine JUMPABLE and HAS_TEXT to cache OP(rn) */
200 /* for use after a quantifier and before an EXACT-like node -- japhy */
201 /* it would be nice to rework regcomp.sym to generate this stuff. sigh
203 * NOTE that *nothing* that affects backtracking should be in here, specifically
204 * VERBS must NOT be included. JUMPABLE is used to determine if we can ignore a
205 * node that is in between two EXACT like nodes when ascertaining what the required
206 * "follow" character is. This should probably be moved to regex compile time
207 * although it may be done at run time beause of the REF possibility - more
208 * investigation required. -- demerphq
210 #define JUMPABLE(rn) ( \
212 (OP(rn) == CLOSE && (!cur_eval || cur_eval->u.eval.close_paren != ARG(rn))) || \
214 OP(rn) == SUSPEND || OP(rn) == IFMATCH || \
215 OP(rn) == PLUS || OP(rn) == MINMOD || \
217 (PL_regkind[OP(rn)] == CURLY && ARG1(rn) > 0) \
219 #define IS_EXACT(rn) (PL_regkind[OP(rn)] == EXACT)
221 #define HAS_TEXT(rn) ( IS_EXACT(rn) || PL_regkind[OP(rn)] == REF )
224 /* Currently these are only used when PL_regkind[OP(rn)] == EXACT so
225 we don't need this definition. XXX These are now out-of-sync*/
226 #define IS_TEXT(rn) ( OP(rn)==EXACT || OP(rn)==REF || OP(rn)==NREF )
227 #define IS_TEXTF(rn) ( OP(rn)==EXACTFU || OP(rn)==EXACTFU_SS || OP(rn)==EXACTFA || OP(rn)==EXACTFA_NO_TRIE || OP(rn)==EXACTF || OP(rn)==REFF || OP(rn)==NREFF )
228 #define IS_TEXTFL(rn) ( OP(rn)==EXACTFL || OP(rn)==REFFL || OP(rn)==NREFFL )
231 /* ... so we use this as its faster. */
232 #define IS_TEXT(rn) ( OP(rn)==EXACT || OP(rn)==EXACTL )
233 #define IS_TEXTFU(rn) ( OP(rn)==EXACTFU || OP(rn)==EXACTFLU8 || OP(rn)==EXACTFU_SS || OP(rn) == EXACTFA || OP(rn) == EXACTFA_NO_TRIE)
234 #define IS_TEXTF(rn) ( OP(rn)==EXACTF )
235 #define IS_TEXTFL(rn) ( OP(rn)==EXACTFL )
240 Search for mandatory following text node; for lookahead, the text must
241 follow but for lookbehind (rn->flags != 0) we skip to the next step.
243 #define FIND_NEXT_IMPT(rn) STMT_START { \
244 while (JUMPABLE(rn)) { \
245 const OPCODE type = OP(rn); \
246 if (type == SUSPEND || PL_regkind[type] == CURLY) \
247 rn = NEXTOPER(NEXTOPER(rn)); \
248 else if (type == PLUS) \
250 else if (type == IFMATCH) \
251 rn = (rn->flags == 0) ? NEXTOPER(NEXTOPER(rn)) : rn + ARG(rn); \
252 else rn += NEXT_OFF(rn); \
256 #define SLAB_FIRST(s) (&(s)->states[0])
257 #define SLAB_LAST(s) (&(s)->states[PERL_REGMATCH_SLAB_SLOTS-1])
259 static void S_setup_eval_state(pTHX_ regmatch_info *const reginfo);
260 static void S_cleanup_regmatch_info_aux(pTHX_ void *arg);
261 static regmatch_state * S_push_slab(pTHX);
263 #define REGCP_PAREN_ELEMS 3
264 #define REGCP_OTHER_ELEMS 3
265 #define REGCP_FRAME_ELEMS 1
266 /* REGCP_FRAME_ELEMS are not part of the REGCP_OTHER_ELEMS and
267 * are needed for the regexp context stack bookkeeping. */
270 S_regcppush(pTHX_ const regexp *rex, I32 parenfloor, U32 maxopenparen)
272 const int retval = PL_savestack_ix;
273 const int paren_elems_to_push =
274 (maxopenparen - parenfloor) * REGCP_PAREN_ELEMS;
275 const UV total_elems = paren_elems_to_push + REGCP_OTHER_ELEMS;
276 const UV elems_shifted = total_elems << SAVE_TIGHT_SHIFT;
278 GET_RE_DEBUG_FLAGS_DECL;
280 PERL_ARGS_ASSERT_REGCPPUSH;
282 if (paren_elems_to_push < 0)
283 Perl_croak(aTHX_ "panic: paren_elems_to_push, %i < 0, maxopenparen: %i parenfloor: %i REGCP_PAREN_ELEMS: %u",
284 (int)paren_elems_to_push, (int)maxopenparen,
285 (int)parenfloor, (unsigned)REGCP_PAREN_ELEMS);
287 if ((elems_shifted >> SAVE_TIGHT_SHIFT) != total_elems)
288 Perl_croak(aTHX_ "panic: paren_elems_to_push offset %"UVuf
289 " out of range (%lu-%ld)",
291 (unsigned long)maxopenparen,
294 SSGROW(total_elems + REGCP_FRAME_ELEMS);
297 if ((int)maxopenparen > (int)parenfloor)
298 PerlIO_printf(Perl_debug_log,
299 "rex=0x%"UVxf" offs=0x%"UVxf": saving capture indices:\n",
304 for (p = parenfloor+1; p <= (I32)maxopenparen; p++) {
305 /* REGCP_PARENS_ELEMS are pushed per pairs of parentheses. */
306 SSPUSHIV(rex->offs[p].end);
307 SSPUSHIV(rex->offs[p].start);
308 SSPUSHINT(rex->offs[p].start_tmp);
309 DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
310 " \\%"UVuf": %"IVdf"(%"IVdf")..%"IVdf"\n",
312 (IV)rex->offs[p].start,
313 (IV)rex->offs[p].start_tmp,
317 /* REGCP_OTHER_ELEMS are pushed in any case, parentheses or no. */
318 SSPUSHINT(maxopenparen);
319 SSPUSHINT(rex->lastparen);
320 SSPUSHINT(rex->lastcloseparen);
321 SSPUSHUV(SAVEt_REGCONTEXT | elems_shifted); /* Magic cookie. */
326 /* These are needed since we do not localize EVAL nodes: */
327 #define REGCP_SET(cp) \
329 PerlIO_printf(Perl_debug_log, \
330 " Setting an EVAL scope, savestack=%"IVdf"\n", \
331 (IV)PL_savestack_ix)); \
334 #define REGCP_UNWIND(cp) \
336 if (cp != PL_savestack_ix) \
337 PerlIO_printf(Perl_debug_log, \
338 " Clearing an EVAL scope, savestack=%"IVdf"..%"IVdf"\n", \
339 (IV)(cp), (IV)PL_savestack_ix)); \
342 #define UNWIND_PAREN(lp, lcp) \
343 for (n = rex->lastparen; n > lp; n--) \
344 rex->offs[n].end = -1; \
345 rex->lastparen = n; \
346 rex->lastcloseparen = lcp;
350 S_regcppop(pTHX_ regexp *rex, U32 *maxopenparen_p)
354 GET_RE_DEBUG_FLAGS_DECL;
356 PERL_ARGS_ASSERT_REGCPPOP;
358 /* Pop REGCP_OTHER_ELEMS before the parentheses loop starts. */
360 assert((i & SAVE_MASK) == SAVEt_REGCONTEXT); /* Check that the magic cookie is there. */
361 i >>= SAVE_TIGHT_SHIFT; /* Parentheses elements to pop. */
362 rex->lastcloseparen = SSPOPINT;
363 rex->lastparen = SSPOPINT;
364 *maxopenparen_p = SSPOPINT;
366 i -= REGCP_OTHER_ELEMS;
367 /* Now restore the parentheses context. */
369 if (i || rex->lastparen + 1 <= rex->nparens)
370 PerlIO_printf(Perl_debug_log,
371 "rex=0x%"UVxf" offs=0x%"UVxf": restoring capture indices to:\n",
376 paren = *maxopenparen_p;
377 for ( ; i > 0; i -= REGCP_PAREN_ELEMS) {
379 rex->offs[paren].start_tmp = SSPOPINT;
380 rex->offs[paren].start = SSPOPIV;
382 if (paren <= rex->lastparen)
383 rex->offs[paren].end = tmps;
384 DEBUG_BUFFERS_r( PerlIO_printf(Perl_debug_log,
385 " \\%"UVuf": %"IVdf"(%"IVdf")..%"IVdf"%s\n",
387 (IV)rex->offs[paren].start,
388 (IV)rex->offs[paren].start_tmp,
389 (IV)rex->offs[paren].end,
390 (paren > rex->lastparen ? "(skipped)" : ""));
395 /* It would seem that the similar code in regtry()
396 * already takes care of this, and in fact it is in
397 * a better location to since this code can #if 0-ed out
398 * but the code in regtry() is needed or otherwise tests
399 * requiring null fields (pat.t#187 and split.t#{13,14}
400 * (as of patchlevel 7877) will fail. Then again,
401 * this code seems to be necessary or otherwise
402 * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
403 * --jhi updated by dapm */
404 for (i = rex->lastparen + 1; i <= rex->nparens; i++) {
405 if (i > *maxopenparen_p)
406 rex->offs[i].start = -1;
407 rex->offs[i].end = -1;
408 DEBUG_BUFFERS_r( PerlIO_printf(Perl_debug_log,
409 " \\%"UVuf": %s ..-1 undeffing\n",
411 (i > *maxopenparen_p) ? "-1" : " "
417 /* restore the parens and associated vars at savestack position ix,
418 * but without popping the stack */
421 S_regcp_restore(pTHX_ regexp *rex, I32 ix, U32 *maxopenparen_p)
423 I32 tmpix = PL_savestack_ix;
424 PL_savestack_ix = ix;
425 regcppop(rex, maxopenparen_p);
426 PL_savestack_ix = tmpix;
429 #define regcpblow(cp) LEAVE_SCOPE(cp) /* Ignores regcppush()ed data. */
432 S_isFOO_lc(pTHX_ const U8 classnum, const U8 character)
434 /* Returns a boolean as to whether or not 'character' is a member of the
435 * Posix character class given by 'classnum' that should be equivalent to a
436 * value in the typedef '_char_class_number'.
438 * Ideally this could be replaced by a just an array of function pointers
439 * to the C library functions that implement the macros this calls.
440 * However, to compile, the precise function signatures are required, and
441 * these may vary from platform to to platform. To avoid having to figure
442 * out what those all are on each platform, I (khw) am using this method,
443 * which adds an extra layer of function call overhead (unless the C
444 * optimizer strips it away). But we don't particularly care about
445 * performance with locales anyway. */
447 switch ((_char_class_number) classnum) {
448 case _CC_ENUM_ALPHANUMERIC: return isALPHANUMERIC_LC(character);
449 case _CC_ENUM_ALPHA: return isALPHA_LC(character);
450 case _CC_ENUM_ASCII: return isASCII_LC(character);
451 case _CC_ENUM_BLANK: return isBLANK_LC(character);
452 case _CC_ENUM_CASED: return isLOWER_LC(character)
453 || isUPPER_LC(character);
454 case _CC_ENUM_CNTRL: return isCNTRL_LC(character);
455 case _CC_ENUM_DIGIT: return isDIGIT_LC(character);
456 case _CC_ENUM_GRAPH: return isGRAPH_LC(character);
457 case _CC_ENUM_LOWER: return isLOWER_LC(character);
458 case _CC_ENUM_PRINT: return isPRINT_LC(character);
459 case _CC_ENUM_PUNCT: return isPUNCT_LC(character);
460 case _CC_ENUM_SPACE: return isSPACE_LC(character);
461 case _CC_ENUM_UPPER: return isUPPER_LC(character);
462 case _CC_ENUM_WORDCHAR: return isWORDCHAR_LC(character);
463 case _CC_ENUM_XDIGIT: return isXDIGIT_LC(character);
464 default: /* VERTSPACE should never occur in locales */
465 Perl_croak(aTHX_ "panic: isFOO_lc() has an unexpected character class '%d'", classnum);
468 NOT_REACHED; /* NOTREACHED */
473 S_isFOO_utf8_lc(pTHX_ const U8 classnum, const U8* character)
475 /* Returns a boolean as to whether or not the (well-formed) UTF-8-encoded
476 * 'character' is a member of the Posix character class given by 'classnum'
477 * that should be equivalent to a value in the typedef
478 * '_char_class_number'.
480 * This just calls isFOO_lc on the code point for the character if it is in
481 * the range 0-255. Outside that range, all characters use Unicode
482 * rules, ignoring any locale. So use the Unicode function if this class
483 * requires a swash, and use the Unicode macro otherwise. */
485 PERL_ARGS_ASSERT_ISFOO_UTF8_LC;
487 if (UTF8_IS_INVARIANT(*character)) {
488 return isFOO_lc(classnum, *character);
490 else if (UTF8_IS_DOWNGRADEABLE_START(*character)) {
491 return isFOO_lc(classnum,
492 TWO_BYTE_UTF8_TO_NATIVE(*character, *(character + 1)));
495 _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(character, character + UTF8SKIP(character));
497 if (classnum < _FIRST_NON_SWASH_CC) {
499 /* Initialize the swash unless done already */
500 if (! PL_utf8_swash_ptrs[classnum]) {
501 U8 flags = _CORE_SWASH_INIT_ACCEPT_INVLIST;
502 PL_utf8_swash_ptrs[classnum] =
503 _core_swash_init("utf8",
506 PL_XPosix_ptrs[classnum], &flags);
509 return cBOOL(swash_fetch(PL_utf8_swash_ptrs[classnum], (U8 *)
511 TRUE /* is UTF */ ));
514 switch ((_char_class_number) classnum) {
515 case _CC_ENUM_SPACE: return is_XPERLSPACE_high(character);
516 case _CC_ENUM_BLANK: return is_HORIZWS_high(character);
517 case _CC_ENUM_XDIGIT: return is_XDIGIT_high(character);
518 case _CC_ENUM_VERTSPACE: return is_VERTWS_high(character);
522 return FALSE; /* Things like CNTRL are always below 256 */
526 * pregexec and friends
529 #ifndef PERL_IN_XSUB_RE
531 - pregexec - match a regexp against a string
534 Perl_pregexec(pTHX_ REGEXP * const prog, char* stringarg, char *strend,
535 char *strbeg, SSize_t minend, SV *screamer, U32 nosave)
536 /* stringarg: the point in the string at which to begin matching */
537 /* strend: pointer to null at end of string */
538 /* strbeg: real beginning of string */
539 /* minend: end of match must be >= minend bytes after stringarg. */
540 /* screamer: SV being matched: only used for utf8 flag, pos() etc; string
541 * itself is accessed via the pointers above */
542 /* nosave: For optimizations. */
544 PERL_ARGS_ASSERT_PREGEXEC;
547 regexec_flags(prog, stringarg, strend, strbeg, minend, screamer, NULL,
548 nosave ? 0 : REXEC_COPY_STR);
554 /* re_intuit_start():
556 * Based on some optimiser hints, try to find the earliest position in the
557 * string where the regex could match.
559 * rx: the regex to match against
560 * sv: the SV being matched: only used for utf8 flag; the string
561 * itself is accessed via the pointers below. Note that on
562 * something like an overloaded SV, SvPOK(sv) may be false
563 * and the string pointers may point to something unrelated to
565 * strbeg: real beginning of string
566 * strpos: the point in the string at which to begin matching
567 * strend: pointer to the byte following the last char of the string
568 * flags currently unused; set to 0
569 * data: currently unused; set to NULL
571 * The basic idea of re_intuit_start() is to use some known information
572 * about the pattern, namely:
574 * a) the longest known anchored substring (i.e. one that's at a
575 * constant offset from the beginning of the pattern; but not
576 * necessarily at a fixed offset from the beginning of the
578 * b) the longest floating substring (i.e. one that's not at a constant
579 * offset from the beginning of the pattern);
580 * c) Whether the pattern is anchored to the string; either
581 * an absolute anchor: /^../, or anchored to \n: /^.../m,
582 * or anchored to pos(): /\G/;
583 * d) A start class: a real or synthetic character class which
584 * represents which characters are legal at the start of the pattern;
586 * to either quickly reject the match, or to find the earliest position
587 * within the string at which the pattern might match, thus avoiding
588 * running the full NFA engine at those earlier locations, only to
589 * eventually fail and retry further along.
591 * Returns NULL if the pattern can't match, or returns the address within
592 * the string which is the earliest place the match could occur.
594 * The longest of the anchored and floating substrings is called 'check'
595 * and is checked first. The other is called 'other' and is checked
596 * second. The 'other' substring may not be present. For example,
598 * /(abc|xyz)ABC\d{0,3}DEFG/
602 * check substr (float) = "DEFG", offset 6..9 chars
603 * other substr (anchored) = "ABC", offset 3..3 chars
606 * Be aware that during the course of this function, sometimes 'anchored'
607 * refers to a substring being anchored relative to the start of the
608 * pattern, and sometimes to the pattern itself being anchored relative to
609 * the string. For example:
611 * /\dabc/: "abc" is anchored to the pattern;
612 * /^\dabc/: "abc" is anchored to the pattern and the string;
613 * /\d+abc/: "abc" is anchored to neither the pattern nor the string;
614 * /^\d+abc/: "abc" is anchored to neither the pattern nor the string,
615 * but the pattern is anchored to the string.
619 Perl_re_intuit_start(pTHX_
622 const char * const strbeg,
626 re_scream_pos_data *data)
628 struct regexp *const prog = ReANY(rx);
629 SSize_t start_shift = prog->check_offset_min;
630 /* Should be nonnegative! */
631 SSize_t end_shift = 0;
632 /* current lowest pos in string where the regex can start matching */
633 char *rx_origin = strpos;
635 const bool utf8_target = (sv && SvUTF8(sv)) ? 1 : 0; /* if no sv we have to assume bytes */
636 U8 other_ix = 1 - prog->substrs->check_ix;
638 char *other_last = strpos;/* latest pos 'other' substr already checked to */
639 char *check_at = NULL; /* check substr found at this pos */
640 const I32 multiline = prog->extflags & RXf_PMf_MULTILINE;
641 RXi_GET_DECL(prog,progi);
642 regmatch_info reginfo_buf; /* create some info to pass to find_byclass */
643 regmatch_info *const reginfo = ®info_buf;
644 GET_RE_DEBUG_FLAGS_DECL;
646 PERL_ARGS_ASSERT_RE_INTUIT_START;
647 PERL_UNUSED_ARG(flags);
648 PERL_UNUSED_ARG(data);
650 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
651 "Intuit: trying to determine minimum start position...\n"));
653 /* for now, assume that all substr offsets are positive. If at some point
654 * in the future someone wants to do clever things with look-behind and
655 * -ve offsets, they'll need to fix up any code in this function
656 * which uses these offsets. See the thread beginning
657 * <20140113145929.GF27210@iabyn.com>
659 assert(prog->substrs->data[0].min_offset >= 0);
660 assert(prog->substrs->data[0].max_offset >= 0);
661 assert(prog->substrs->data[1].min_offset >= 0);
662 assert(prog->substrs->data[1].max_offset >= 0);
663 assert(prog->substrs->data[2].min_offset >= 0);
664 assert(prog->substrs->data[2].max_offset >= 0);
666 /* for now, assume that if both present, that the floating substring
667 * doesn't start before the anchored substring.
668 * If you break this assumption (e.g. doing better optimisations
669 * with lookahead/behind), then you'll need to audit the code in this
670 * function carefully first
673 ! ( (prog->anchored_utf8 || prog->anchored_substr)
674 && (prog->float_utf8 || prog->float_substr))
675 || (prog->float_min_offset >= prog->anchored_offset));
677 /* byte rather than char calculation for efficiency. It fails
678 * to quickly reject some cases that can't match, but will reject
679 * them later after doing full char arithmetic */
680 if (prog->minlen > strend - strpos) {
681 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
682 " String too short...\n"));
686 RX_MATCH_UTF8_set(rx,utf8_target);
687 reginfo->is_utf8_target = cBOOL(utf8_target);
688 reginfo->info_aux = NULL;
689 reginfo->strbeg = strbeg;
690 reginfo->strend = strend;
691 reginfo->is_utf8_pat = cBOOL(RX_UTF8(rx));
693 /* not actually used within intuit, but zero for safety anyway */
694 reginfo->poscache_maxiter = 0;
697 if (!prog->check_utf8 && prog->check_substr)
698 to_utf8_substr(prog);
699 check = prog->check_utf8;
701 if (!prog->check_substr && prog->check_utf8) {
702 if (! to_byte_substr(prog)) {
703 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(fail);
706 check = prog->check_substr;
709 /* dump the various substring data */
710 DEBUG_OPTIMISE_MORE_r({
712 for (i=0; i<=2; i++) {
713 SV *sv = (utf8_target ? prog->substrs->data[i].utf8_substr
714 : prog->substrs->data[i].substr);
718 PerlIO_printf(Perl_debug_log,
719 " substrs[%d]: min=%"IVdf" max=%"IVdf" end shift=%"IVdf
720 " useful=%"IVdf" utf8=%d [%s]\n",
722 (IV)prog->substrs->data[i].min_offset,
723 (IV)prog->substrs->data[i].max_offset,
724 (IV)prog->substrs->data[i].end_shift,
731 if (prog->intflags & PREGf_ANCH) { /* Match at \G, beg-of-str or after \n */
733 /* ml_anch: check after \n?
735 * A note about PREGf_IMPLICIT: on an un-anchored pattern beginning
736 * with /.*.../, these flags will have been added by the
738 * /.*abc/, /.*abc/m: PREGf_IMPLICIT | PREGf_ANCH_MBOL
739 * /.*abc/s: PREGf_IMPLICIT | PREGf_ANCH_SBOL
741 ml_anch = (prog->intflags & PREGf_ANCH_MBOL)
742 && !(prog->intflags & PREGf_IMPLICIT);
744 if (!ml_anch && !(prog->intflags & PREGf_IMPLICIT)) {
745 /* we are only allowed to match at BOS or \G */
747 /* trivially reject if there's a BOS anchor and we're not at BOS.
749 * Note that we don't try to do a similar quick reject for
750 * \G, since generally the caller will have calculated strpos
751 * based on pos() and gofs, so the string is already correctly
752 * anchored by definition; and handling the exceptions would
753 * be too fiddly (e.g. REXEC_IGNOREPOS).
755 if ( strpos != strbeg
756 && (prog->intflags & PREGf_ANCH_SBOL))
758 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
759 " Not at start...\n"));
763 /* in the presence of an anchor, the anchored (relative to the
764 * start of the regex) substr must also be anchored relative
765 * to strpos. So quickly reject if substr isn't found there.
766 * This works for \G too, because the caller will already have
767 * subtracted gofs from pos, and gofs is the offset from the
768 * \G to the start of the regex. For example, in /.abc\Gdef/,
769 * where substr="abcdef", pos()=3, gofs=4, offset_min=1:
770 * caller will have set strpos=pos()-4; we look for the substr
771 * at position pos()-4+1, which lines up with the "a" */
773 if (prog->check_offset_min == prog->check_offset_max
774 && !(prog->intflags & PREGf_CANY_SEEN))
776 /* Substring at constant offset from beg-of-str... */
777 SSize_t slen = SvCUR(check);
778 char *s = HOP3c(strpos, prog->check_offset_min, strend);
780 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
781 " Looking for check substr at fixed offset %"IVdf"...\n",
782 (IV)prog->check_offset_min));
785 /* In this case, the regex is anchored at the end too.
786 * Unless it's a multiline match, the lengths must match
787 * exactly, give or take a \n. NB: slen >= 1 since
788 * the last char of check is \n */
790 && ( strend - s > slen
791 || strend - s < slen - 1
792 || (strend - s == slen && strend[-1] != '\n')))
794 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
795 " String too long...\n"));
798 /* Now should match s[0..slen-2] */
801 if (slen && (*SvPVX_const(check) != *s
802 || (slen > 1 && memNE(SvPVX_const(check), s, slen))))
804 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
805 " String not equal...\n"));
810 goto success_at_start;
815 end_shift = prog->check_end_shift;
817 #ifdef DEBUGGING /* 7/99: reports of failure (with the older version) */
819 Perl_croak(aTHX_ "panic: end_shift: %"IVdf" pattern:\n%s\n ",
820 (IV)end_shift, RX_PRECOMP(prog));
825 /* This is the (re)entry point of the main loop in this function.
826 * The goal of this loop is to:
827 * 1) find the "check" substring in the region rx_origin..strend
828 * (adjusted by start_shift / end_shift). If not found, reject
830 * 2) If it exists, look for the "other" substr too if defined; for
831 * example, if the check substr maps to the anchored substr, then
832 * check the floating substr, and vice-versa. If not found, go
833 * back to (1) with rx_origin suitably incremented.
834 * 3) If we find an rx_origin position that doesn't contradict
835 * either of the substrings, then check the possible additional
836 * constraints on rx_origin of /^.../m or a known start class.
837 * If these fail, then depending on which constraints fail, jump
838 * back to here, or to various other re-entry points further along
839 * that skip some of the first steps.
840 * 4) If we pass all those tests, update the BmUSEFUL() count on the
841 * substring. If the start position was determined to be at the
842 * beginning of the string - so, not rejected, but not optimised,
843 * since we have to run regmatch from position 0 - decrement the
844 * BmUSEFUL() count. Otherwise increment it.
848 /* first, look for the 'check' substring */
854 DEBUG_OPTIMISE_MORE_r({
855 PerlIO_printf(Perl_debug_log,
856 " At restart: rx_origin=%"IVdf" Check offset min: %"IVdf
857 " Start shift: %"IVdf" End shift %"IVdf
858 " Real end Shift: %"IVdf"\n",
859 (IV)(rx_origin - strbeg),
860 (IV)prog->check_offset_min,
863 (IV)prog->check_end_shift);
866 if (prog->intflags & PREGf_CANY_SEEN) {
867 start_point= (U8*)(rx_origin + start_shift);
868 end_point= (U8*)(strend - end_shift);
869 if (start_point > end_point)
872 end_point = HOP3(strend, -end_shift, strbeg);
873 start_point = HOPMAYBE3(rx_origin, start_shift, end_point);
879 /* If the regex is absolutely anchored to either the start of the
880 * string (SBOL) or to pos() (ANCH_GPOS), then
881 * check_offset_max represents an upper bound on the string where
882 * the substr could start. For the ANCH_GPOS case, we assume that
883 * the caller of intuit will have already set strpos to
884 * pos()-gofs, so in this case strpos + offset_max will still be
885 * an upper bound on the substr.
888 && prog->intflags & PREGf_ANCH
889 && prog->check_offset_max != SSize_t_MAX)
891 SSize_t len = SvCUR(check) - !!SvTAIL(check);
892 const char * const anchor =
893 (prog->intflags & PREGf_ANCH_GPOS ? strpos : strbeg);
895 /* do a bytes rather than chars comparison. It's conservative;
896 * so it skips doing the HOP if the result can't possibly end
897 * up earlier than the old value of end_point.
899 if ((char*)end_point - anchor > prog->check_offset_max) {
900 end_point = HOP3lim((U8*)anchor,
901 prog->check_offset_max,
907 check_at = fbm_instr( start_point, end_point,
908 check, multiline ? FBMrf_MULTILINE : 0);
910 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
911 " doing 'check' fbm scan, [%"IVdf"..%"IVdf"] gave %"IVdf"\n",
912 (IV)((char*)start_point - strbeg),
913 (IV)((char*)end_point - strbeg),
914 (IV)(check_at ? check_at - strbeg : -1)
917 /* Update the count-of-usability, remove useless subpatterns,
921 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
922 SvPVX_const(check), RE_SV_DUMPLEN(check), 30);
923 PerlIO_printf(Perl_debug_log, " %s %s substr %s%s%s",
924 (check_at ? "Found" : "Did not find"),
925 (check == (utf8_target ? prog->anchored_utf8 : prog->anchored_substr)
926 ? "anchored" : "floating"),
929 (check_at ? " at offset " : "...\n") );
934 /* set rx_origin to the minimum position where the regex could start
935 * matching, given the constraint of the just-matched check substring.
936 * But don't set it lower than previously.
939 if (check_at - rx_origin > prog->check_offset_max)
940 rx_origin = HOP3c(check_at, -prog->check_offset_max, rx_origin);
941 /* Finish the diagnostic message */
942 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
943 "%ld (rx_origin now %"IVdf")...\n",
944 (long)(check_at - strbeg),
945 (IV)(rx_origin - strbeg)
950 /* now look for the 'other' substring if defined */
952 if (utf8_target ? prog->substrs->data[other_ix].utf8_substr
953 : prog->substrs->data[other_ix].substr)
955 /* Take into account the "other" substring. */
959 struct reg_substr_datum *other;
962 other = &prog->substrs->data[other_ix];
964 /* if "other" is anchored:
965 * we've previously found a floating substr starting at check_at.
966 * This means that the regex origin must lie somewhere
967 * between min (rx_origin): HOP3(check_at, -check_offset_max)
968 * and max: HOP3(check_at, -check_offset_min)
969 * (except that min will be >= strpos)
970 * So the fixed substr must lie somewhere between
971 * HOP3(min, anchored_offset)
972 * HOP3(max, anchored_offset) + SvCUR(substr)
975 /* if "other" is floating
976 * Calculate last1, the absolute latest point where the
977 * floating substr could start in the string, ignoring any
978 * constraints from the earlier fixed match. It is calculated
981 * strend - prog->minlen (in chars) is the absolute latest
982 * position within the string where the origin of the regex
983 * could appear. The latest start point for the floating
984 * substr is float_min_offset(*) on from the start of the
985 * regex. last1 simply combines thee two offsets.
987 * (*) You might think the latest start point should be
988 * float_max_offset from the regex origin, and technically
989 * you'd be correct. However, consider
991 * Here, float min, max are 3,5 and minlen is 7.
992 * This can match either
996 * In the first case, the regex matches minlen chars; in the
997 * second, minlen+1, in the third, minlen+2.
998 * In the first case, the floating offset is 3 (which equals
999 * float_min), in the second, 4, and in the third, 5 (which
1000 * equals float_max). In all cases, the floating string bcd
1001 * can never start more than 4 chars from the end of the
1002 * string, which equals minlen - float_min. As the substring
1003 * starts to match more than float_min from the start of the
1004 * regex, it makes the regex match more than minlen chars,
1005 * and the two cancel each other out. So we can always use
1006 * float_min - minlen, rather than float_max - minlen for the
1007 * latest position in the string.
1009 * Note that -minlen + float_min_offset is equivalent (AFAIKT)
1010 * to CHR_SVLEN(must) - !!SvTAIL(must) + prog->float_end_shift
1013 assert(prog->minlen >= other->min_offset);
1014 last1 = HOP3c(strend,
1015 other->min_offset - prog->minlen, strbeg);
1017 if (other_ix) {/* i.e. if (other-is-float) */
1018 /* last is the latest point where the floating substr could
1019 * start, *given* any constraints from the earlier fixed
1020 * match. This constraint is that the floating string starts
1021 * <= float_max_offset chars from the regex origin (rx_origin).
1022 * If this value is less than last1, use it instead.
1024 assert(rx_origin <= last1);
1026 /* this condition handles the offset==infinity case, and
1027 * is a short-cut otherwise. Although it's comparing a
1028 * byte offset to a char length, it does so in a safe way,
1029 * since 1 char always occupies 1 or more bytes,
1030 * so if a string range is (last1 - rx_origin) bytes,
1031 * it will be less than or equal to (last1 - rx_origin)
1032 * chars; meaning it errs towards doing the accurate HOP3
1033 * rather than just using last1 as a short-cut */
1034 (last1 - rx_origin) < other->max_offset
1036 : (char*)HOP3lim(rx_origin, other->max_offset, last1);
1039 assert(strpos + start_shift <= check_at);
1040 last = HOP4c(check_at, other->min_offset - start_shift,
1044 s = HOP3c(rx_origin, other->min_offset, strend);
1045 if (s < other_last) /* These positions already checked */
1048 must = utf8_target ? other->utf8_substr : other->substr;
1049 assert(SvPOK(must));
1052 char *to = last + SvCUR(must) - (SvTAIL(must)!=0);
1056 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1057 " skipping 'other' fbm scan: %"IVdf" > %"IVdf"\n",
1058 (IV)(from - strbeg),
1064 (unsigned char*)from,
1067 multiline ? FBMrf_MULTILINE : 0
1069 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1070 " doing 'other' fbm scan, [%"IVdf"..%"IVdf"] gave %"IVdf"\n",
1071 (IV)(from - strbeg),
1073 (IV)(s ? s - strbeg : -1)
1079 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
1080 SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
1081 PerlIO_printf(Perl_debug_log, " %s %s substr %s%s",
1082 s ? "Found" : "Contradicts",
1083 other_ix ? "floating" : "anchored",
1084 quoted, RE_SV_TAIL(must));
1089 /* last1 is latest possible substr location. If we didn't
1090 * find it before there, we never will */
1091 if (last >= last1) {
1092 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1093 "; giving up...\n"));
1097 /* try to find the check substr again at a later
1098 * position. Maybe next time we'll find the "other" substr
1100 other_last = HOP3c(last, 1, strend) /* highest failure */;
1102 other_ix /* i.e. if other-is-float */
1103 ? HOP3c(rx_origin, 1, strend)
1104 : HOP4c(last, 1 - other->min_offset, strbeg, strend);
1105 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1106 "; about to retry %s at offset %ld (rx_origin now %"IVdf")...\n",
1107 (other_ix ? "floating" : "anchored"),
1108 (long)(HOP3c(check_at, 1, strend) - strbeg),
1109 (IV)(rx_origin - strbeg)
1114 if (other_ix) { /* if (other-is-float) */
1115 /* other_last is set to s, not s+1, since its possible for
1116 * a floating substr to fail first time, then succeed
1117 * second time at the same floating position; e.g.:
1118 * "-AB--AABZ" =~ /\wAB\d*Z/
1119 * The first time round, anchored and float match at
1120 * "-(AB)--AAB(Z)" then fail on the initial \w character
1121 * class. Second time round, they match at "-AB--A(AB)(Z)".
1126 rx_origin = HOP3c(s, -other->min_offset, strbeg);
1127 other_last = HOP3c(s, 1, strend);
1129 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1130 " at offset %ld (rx_origin now %"IVdf")...\n",
1132 (IV)(rx_origin - strbeg)
1138 DEBUG_OPTIMISE_MORE_r(
1139 PerlIO_printf(Perl_debug_log,
1140 " Check-only match: offset min:%"IVdf" max:%"IVdf
1141 " check_at:%"IVdf" rx_origin:%"IVdf" rx_origin-check_at:%"IVdf
1142 " strend:%"IVdf"\n",
1143 (IV)prog->check_offset_min,
1144 (IV)prog->check_offset_max,
1145 (IV)(check_at-strbeg),
1146 (IV)(rx_origin-strbeg),
1147 (IV)(rx_origin-check_at),
1153 postprocess_substr_matches:
1155 /* handle the extra constraint of /^.../m if present */
1157 if (ml_anch && rx_origin != strbeg && rx_origin[-1] != '\n') {
1160 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1161 " looking for /^/m anchor"));
1163 /* we have failed the constraint of a \n before rx_origin.
1164 * Find the next \n, if any, even if it's beyond the current
1165 * anchored and/or floating substrings. Whether we should be
1166 * scanning ahead for the next \n or the next substr is debatable.
1167 * On the one hand you'd expect rare substrings to appear less
1168 * often than \n's. On the other hand, searching for \n means
1169 * we're effectively flipping between check_substr and "\n" on each
1170 * iteration as the current "rarest" string candidate, which
1171 * means for example that we'll quickly reject the whole string if
1172 * hasn't got a \n, rather than trying every substr position
1176 s = HOP3c(strend, - prog->minlen, strpos);
1177 if (s <= rx_origin ||
1178 ! ( rx_origin = (char *)memchr(rx_origin, '\n', s - rx_origin)))
1180 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1181 " Did not find /%s^%s/m...\n",
1182 PL_colors[0], PL_colors[1]));
1186 /* earliest possible origin is 1 char after the \n.
1187 * (since *rx_origin == '\n', it's safe to ++ here rather than
1188 * HOP(rx_origin, 1)) */
1191 if (prog->substrs->check_ix == 0 /* check is anchored */
1192 || rx_origin >= HOP3c(check_at, - prog->check_offset_min, strpos))
1194 /* Position contradicts check-string; either because
1195 * check was anchored (and thus has no wiggle room),
1196 * or check was float and rx_origin is above the float range */
1197 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1198 " Found /%s^%s/m, about to restart lookup for check-string with rx_origin %ld...\n",
1199 PL_colors[0], PL_colors[1], (long)(rx_origin - strbeg)));
1203 /* if we get here, the check substr must have been float,
1204 * is in range, and we may or may not have had an anchored
1205 * "other" substr which still contradicts */
1206 assert(prog->substrs->check_ix); /* check is float */
1208 if (utf8_target ? prog->anchored_utf8 : prog->anchored_substr) {
1209 /* whoops, the anchored "other" substr exists, so we still
1210 * contradict. On the other hand, the float "check" substr
1211 * didn't contradict, so just retry the anchored "other"
1213 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1214 " Found /%s^%s/m, rescanning for anchored from offset %ld (rx_origin now %"IVdf")...\n",
1215 PL_colors[0], PL_colors[1],
1216 (long)(rx_origin - strbeg + prog->anchored_offset),
1217 (long)(rx_origin - strbeg)
1219 goto do_other_substr;
1222 /* success: we don't contradict the found floating substring
1223 * (and there's no anchored substr). */
1224 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1225 " Found /%s^%s/m with rx_origin %ld...\n",
1226 PL_colors[0], PL_colors[1], (long)(rx_origin - strbeg)));
1229 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1230 " (multiline anchor test skipped)\n"));
1236 /* if we have a starting character class, then test that extra constraint.
1237 * (trie stclasses are too expensive to use here, we are better off to
1238 * leave it to regmatch itself) */
1240 if (progi->regstclass && PL_regkind[OP(progi->regstclass)]!=TRIE) {
1241 const U8* const str = (U8*)STRING(progi->regstclass);
1243 /* XXX this value could be pre-computed */
1244 const int cl_l = (PL_regkind[OP(progi->regstclass)] == EXACT
1245 ? (reginfo->is_utf8_pat
1246 ? utf8_distance(str + STR_LEN(progi->regstclass), str)
1247 : STR_LEN(progi->regstclass))
1251 /* latest pos that a matching float substr constrains rx start to */
1252 char *rx_max_float = NULL;
1254 /* if the current rx_origin is anchored, either by satisfying an
1255 * anchored substring constraint, or a /^.../m constraint, then we
1256 * can reject the current origin if the start class isn't found
1257 * at the current position. If we have a float-only match, then
1258 * rx_origin is constrained to a range; so look for the start class
1259 * in that range. if neither, then look for the start class in the
1260 * whole rest of the string */
1262 /* XXX DAPM it's not clear what the minlen test is for, and why
1263 * it's not used in the floating case. Nothing in the test suite
1264 * causes minlen == 0 here. See <20140313134639.GS12844@iabyn.com>.
1265 * Here are some old comments, which may or may not be correct:
1267 * minlen == 0 is possible if regstclass is \b or \B,
1268 * and the fixed substr is ''$.
1269 * Since minlen is already taken into account, rx_origin+1 is
1270 * before strend; accidentally, minlen >= 1 guaranties no false
1271 * positives at rx_origin + 1 even for \b or \B. But (minlen? 1 :
1272 * 0) below assumes that regstclass does not come from lookahead...
1273 * If regstclass takes bytelength more than 1: If charlength==1, OK.
1274 * This leaves EXACTF-ish only, which are dealt with in
1278 if (prog->anchored_substr || prog->anchored_utf8 || ml_anch)
1279 endpos= HOP3c(rx_origin, (prog->minlen ? cl_l : 0), strend);
1280 else if (prog->float_substr || prog->float_utf8) {
1281 rx_max_float = HOP3c(check_at, -start_shift, strbeg);
1282 endpos= HOP3c(rx_max_float, cl_l, strend);
1287 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1288 " looking for class: start_shift: %"IVdf" check_at: %"IVdf
1289 " rx_origin: %"IVdf" endpos: %"IVdf"\n",
1290 (IV)start_shift, (IV)(check_at - strbeg),
1291 (IV)(rx_origin - strbeg), (IV)(endpos - strbeg)));
1293 s = find_byclass(prog, progi->regstclass, rx_origin, endpos,
1296 if (endpos == strend) {
1297 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1298 " Could not match STCLASS...\n") );
1301 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1302 " This position contradicts STCLASS...\n") );
1303 if ((prog->intflags & PREGf_ANCH) && !ml_anch
1304 && !(prog->intflags & PREGf_IMPLICIT))
1307 /* Contradict one of substrings */
1308 if (prog->anchored_substr || prog->anchored_utf8) {
1309 if (prog->substrs->check_ix == 1) { /* check is float */
1310 /* Have both, check_string is floating */
1311 assert(rx_origin + start_shift <= check_at);
1312 if (rx_origin + start_shift != check_at) {
1313 /* not at latest position float substr could match:
1314 * Recheck anchored substring, but not floating.
1315 * The condition above is in bytes rather than
1316 * chars for efficiency. It's conservative, in
1317 * that it errs on the side of doing 'goto
1318 * do_other_substr'. In this case, at worst,
1319 * an extra anchored search may get done, but in
1320 * practice the extra fbm_instr() is likely to
1321 * get skipped anyway. */
1322 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1323 " about to retry anchored at offset %ld (rx_origin now %"IVdf")...\n",
1324 (long)(other_last - strbeg),
1325 (IV)(rx_origin - strbeg)
1327 goto do_other_substr;
1335 /* In the presence of ml_anch, we might be able to
1336 * find another \n without breaking the current float
1339 /* strictly speaking this should be HOP3c(..., 1, ...),
1340 * but since we goto a block of code that's going to
1341 * search for the next \n if any, its safe here */
1343 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1344 " about to look for /%s^%s/m starting at rx_origin %ld...\n",
1345 PL_colors[0], PL_colors[1],
1346 (long)(rx_origin - strbeg)) );
1347 goto postprocess_substr_matches;
1350 /* strictly speaking this can never be true; but might
1351 * be if we ever allow intuit without substrings */
1352 if (!(utf8_target ? prog->float_utf8 : prog->float_substr))
1355 rx_origin = rx_max_float;
1358 /* at this point, any matching substrings have been
1359 * contradicted. Start again... */
1361 rx_origin = HOP3c(rx_origin, 1, strend);
1363 /* uses bytes rather than char calculations for efficiency.
1364 * It's conservative: it errs on the side of doing 'goto restart',
1365 * where there is code that does a proper char-based test */
1366 if (rx_origin + start_shift + end_shift > strend) {
1367 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1368 " Could not match STCLASS...\n") );
1371 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1372 " about to look for %s substr starting at offset %ld (rx_origin now %"IVdf")...\n",
1373 (prog->substrs->check_ix ? "floating" : "anchored"),
1374 (long)(rx_origin + start_shift - strbeg),
1375 (IV)(rx_origin - strbeg)
1382 if (rx_origin != s) {
1383 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1384 " By STCLASS: moving %ld --> %ld\n",
1385 (long)(rx_origin - strbeg), (long)(s - strbeg))
1389 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1390 " Does not contradict STCLASS...\n");
1395 /* Decide whether using the substrings helped */
1397 if (rx_origin != strpos) {
1398 /* Fixed substring is found far enough so that the match
1399 cannot start at strpos. */
1401 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, " try at offset...\n"));
1402 ++BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr); /* hooray/5 */
1405 /* The found rx_origin position does not prohibit matching at
1406 * strpos, so calling intuit didn't gain us anything. Decrement
1407 * the BmUSEFUL() count on the check substring, and if we reach
1409 if (!(prog->intflags & PREGf_NAUGHTY)
1411 prog->check_utf8 /* Could be deleted already */
1412 && --BmUSEFUL(prog->check_utf8) < 0
1413 && (prog->check_utf8 == prog->float_utf8)
1415 prog->check_substr /* Could be deleted already */
1416 && --BmUSEFUL(prog->check_substr) < 0
1417 && (prog->check_substr == prog->float_substr)
1420 /* If flags & SOMETHING - do not do it many times on the same match */
1421 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, " ... Disabling check substring...\n"));
1422 /* XXX Does the destruction order has to change with utf8_target? */
1423 SvREFCNT_dec(utf8_target ? prog->check_utf8 : prog->check_substr);
1424 SvREFCNT_dec(utf8_target ? prog->check_substr : prog->check_utf8);
1425 prog->check_substr = prog->check_utf8 = NULL; /* disable */
1426 prog->float_substr = prog->float_utf8 = NULL; /* clear */
1427 check = NULL; /* abort */
1428 /* XXXX This is a remnant of the old implementation. It
1429 looks wasteful, since now INTUIT can use many
1430 other heuristics. */
1431 prog->extflags &= ~RXf_USE_INTUIT;
1435 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1436 "Intuit: %sSuccessfully guessed:%s match at offset %ld\n",
1437 PL_colors[4], PL_colors[5], (long)(rx_origin - strbeg)) );
1441 fail_finish: /* Substring not found */
1442 if (prog->check_substr || prog->check_utf8) /* could be removed already */
1443 BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr) += 5; /* hooray */
1445 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch rejected by optimizer%s\n",
1446 PL_colors[4], PL_colors[5]));
1451 #define DECL_TRIE_TYPE(scan) \
1452 const enum { trie_plain, trie_utf8, trie_utf8_fold, trie_latin_utf8_fold, \
1453 trie_utf8_exactfa_fold, trie_latin_utf8_exactfa_fold, \
1454 trie_utf8l, trie_flu8 } \
1455 trie_type = ((scan->flags == EXACT) \
1456 ? (utf8_target ? trie_utf8 : trie_plain) \
1457 : (scan->flags == EXACTL) \
1458 ? (utf8_target ? trie_utf8l : trie_plain) \
1459 : (scan->flags == EXACTFA) \
1461 ? trie_utf8_exactfa_fold \
1462 : trie_latin_utf8_exactfa_fold) \
1463 : (scan->flags == EXACTFLU8 \
1467 : trie_latin_utf8_fold)))
1469 #define REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc, uscan, len, uvc, charid, foldlen, foldbuf, uniflags) \
1472 U8 flags = FOLD_FLAGS_FULL; \
1473 switch (trie_type) { \
1475 _CHECK_AND_WARN_PROBLEMATIC_LOCALE; \
1476 if (utf8_target && UTF8_IS_ABOVE_LATIN1(*uc)) { \
1477 _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(uc, uc + UTF8SKIP(uc)); \
1479 goto do_trie_utf8_fold; \
1480 case trie_utf8_exactfa_fold: \
1481 flags |= FOLD_FLAGS_NOMIX_ASCII; \
1483 case trie_utf8_fold: \
1484 do_trie_utf8_fold: \
1485 if ( foldlen>0 ) { \
1486 uvc = utf8n_to_uvchr( (const U8*) uscan, UTF8_MAXLEN, &len, uniflags ); \
1491 uvc = _to_utf8_fold_flags( (const U8*) uc, foldbuf, &foldlen, flags); \
1492 len = UTF8SKIP(uc); \
1493 skiplen = UNISKIP( uvc ); \
1494 foldlen -= skiplen; \
1495 uscan = foldbuf + skiplen; \
1498 case trie_latin_utf8_exactfa_fold: \
1499 flags |= FOLD_FLAGS_NOMIX_ASCII; \
1501 case trie_latin_utf8_fold: \
1502 if ( foldlen>0 ) { \
1503 uvc = utf8n_to_uvchr( (const U8*) uscan, UTF8_MAXLEN, &len, uniflags ); \
1509 uvc = _to_fold_latin1( (U8) *uc, foldbuf, &foldlen, flags); \
1510 skiplen = UNISKIP( uvc ); \
1511 foldlen -= skiplen; \
1512 uscan = foldbuf + skiplen; \
1516 _CHECK_AND_WARN_PROBLEMATIC_LOCALE; \
1517 if (utf8_target && UTF8_IS_ABOVE_LATIN1(*uc)) { \
1518 _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(uc, uc + UTF8SKIP(uc)); \
1522 uvc = utf8n_to_uvchr( (const U8*) uc, UTF8_MAXLEN, &len, uniflags ); \
1529 charid = trie->charmap[ uvc ]; \
1533 if (widecharmap) { \
1534 SV** const svpp = hv_fetch(widecharmap, \
1535 (char*)&uvc, sizeof(UV), 0); \
1537 charid = (U16)SvIV(*svpp); \
1542 #define DUMP_EXEC_POS(li,s,doutf8) \
1543 dump_exec_pos(li,s,(reginfo->strend),(reginfo->strbeg), \
1546 #define REXEC_FBC_EXACTISH_SCAN(COND) \
1550 && (ln == 1 || folder(s, pat_string, ln)) \
1551 && (reginfo->intuit || regtry(reginfo, &s)) )\
1557 #define REXEC_FBC_UTF8_SCAN(CODE) \
1559 while (s < strend) { \
1565 #define REXEC_FBC_SCAN(CODE) \
1567 while (s < strend) { \
1573 #define REXEC_FBC_UTF8_CLASS_SCAN(COND) \
1574 REXEC_FBC_UTF8_SCAN( /* Loops while (s < strend) */ \
1576 if (tmp && (reginfo->intuit || regtry(reginfo, &s))) \
1585 #define REXEC_FBC_CLASS_SCAN(COND) \
1586 REXEC_FBC_SCAN( /* Loops while (s < strend) */ \
1588 if (tmp && (reginfo->intuit || regtry(reginfo, &s))) \
1597 #define REXEC_FBC_CSCAN(CONDUTF8,COND) \
1598 if (utf8_target) { \
1599 REXEC_FBC_UTF8_CLASS_SCAN(CONDUTF8); \
1602 REXEC_FBC_CLASS_SCAN(COND); \
1605 /* The three macros below are slightly different versions of the same logic.
1607 * The first is for /a and /aa when the target string is UTF-8. This can only
1608 * match ascii, but it must advance based on UTF-8. The other two handle the
1609 * non-UTF-8 and the more generic UTF-8 cases. In all three, we are looking
1610 * for the boundary (or non-boundary) between a word and non-word character.
1611 * The utf8 and non-utf8 cases have the same logic, but the details must be
1612 * different. Find the "wordness" of the character just prior to this one, and
1613 * compare it with the wordness of this one. If they differ, we have a
1614 * boundary. At the beginning of the string, pretend that the previous
1615 * character was a new-line.
1617 * All these macros uncleanly have side-effects with each other and outside
1618 * variables. So far it's been too much trouble to clean-up
1620 * TEST_NON_UTF8 is the macro or function to call to test if its byte input is
1621 * a word character or not.
1622 * IF_SUCCESS is code to do if it finds that we are at a boundary between
1624 * IF_FAIL is code to do if we aren't at a boundary between word/non-word
1626 * Exactly one of the two IF_FOO parameters is a no-op, depending on whether we
1627 * are looking for a boundary or for a non-boundary. If we are looking for a
1628 * boundary, we want IF_FAIL to be the no-op, and for IF_SUCCESS to go out and
1629 * see if this tentative match actually works, and if so, to quit the loop
1630 * here. And vice-versa if we are looking for a non-boundary.
1632 * 'tmp' below in the next three macros in the REXEC_FBC_SCAN and
1633 * REXEC_FBC_UTF8_SCAN loops is a loop invariant, a bool giving the return of
1634 * TEST_NON_UTF8(s-1). To see this, note that that's what it is defined to be
1635 * at entry to the loop, and to get to the IF_FAIL branch, tmp must equal
1636 * TEST_NON_UTF8(s), and in the opposite branch, IF_SUCCESS, tmp is that
1637 * complement. But in that branch we complement tmp, meaning that at the
1638 * bottom of the loop tmp is always going to be equal to TEST_NON_UTF8(s),
1639 * which means at the top of the loop in the next iteration, it is
1640 * TEST_NON_UTF8(s-1) */
1641 #define FBC_UTF8_A(TEST_NON_UTF8, IF_SUCCESS, IF_FAIL) \
1642 tmp = (s != reginfo->strbeg) ? UCHARAT(s - 1) : '\n'; \
1643 tmp = TEST_NON_UTF8(tmp); \
1644 REXEC_FBC_UTF8_SCAN( /* advances s while s < strend */ \
1645 if (tmp == ! TEST_NON_UTF8((U8) *s)) { \
1647 IF_SUCCESS; /* Is a boundary if values for s-1 and s differ */ \
1654 /* Like FBC_UTF8_A, but TEST_UV is a macro which takes a UV as its input, and
1655 * TEST_UTF8 is a macro that for the same input code points returns identically
1656 * to TEST_UV, but takes a pointer to a UTF-8 encoded string instead */
1657 #define FBC_UTF8(TEST_UV, TEST_UTF8, IF_SUCCESS, IF_FAIL) \
1658 if (s == reginfo->strbeg) { \
1661 else { /* Back-up to the start of the previous character */ \
1662 U8 * const r = reghop3((U8*)s, -1, (U8*)reginfo->strbeg); \
1663 tmp = utf8n_to_uvchr(r, (U8*) reginfo->strend - r, \
1664 0, UTF8_ALLOW_DEFAULT); \
1666 tmp = TEST_UV(tmp); \
1667 LOAD_UTF8_CHARCLASS_ALNUM(); \
1668 REXEC_FBC_UTF8_SCAN( /* advances s while s < strend */ \
1669 if (tmp == ! (TEST_UTF8((U8 *) s))) { \
1678 /* Like the above two macros. UTF8_CODE is the complete code for handling
1679 * UTF-8. Common to the BOUND and NBOUND cases, set-up by the FBC_BOUND, etc
1681 #define FBC_BOUND_COMMON(UTF8_CODE, TEST_NON_UTF8, IF_SUCCESS, IF_FAIL) \
1682 if (utf8_target) { \
1685 else { /* Not utf8 */ \
1686 tmp = (s != reginfo->strbeg) ? UCHARAT(s - 1) : '\n'; \
1687 tmp = TEST_NON_UTF8(tmp); \
1688 REXEC_FBC_SCAN( /* advances s while s < strend */ \
1689 if (tmp == ! TEST_NON_UTF8((U8) *s)) { \
1698 /* Here, things have been set up by the previous code so that tmp is the \
1699 * return of TEST_NON_UTF(s-1) or TEST_UTF8(s-1) (depending on the \
1700 * utf8ness of the target). We also have to check if this matches against \
1701 * the EOS, which we treat as a \n (which is the same value in both UTF-8 \
1702 * or non-UTF8, so can use the non-utf8 test condition even for a UTF-8 \
1704 if (tmp == ! TEST_NON_UTF8('\n')) { \
1711 /* This is the macro to use when we want to see if something that looks like it
1712 * could match, actually does, and if so exits the loop */
1713 #define REXEC_FBC_TRYIT \
1714 if ((reginfo->intuit || regtry(reginfo, &s))) \
1717 /* The only difference between the BOUND and NBOUND cases is that
1718 * REXEC_FBC_TRYIT is called when matched in BOUND, and when non-matched in
1719 * NBOUND. This is accomplished by passing it as either the if or else clause,
1720 * with the other one being empty (PLACEHOLDER is defined as empty).
1722 * The TEST_FOO parameters are for operating on different forms of input, but
1723 * all should be ones that return identically for the same underlying code
1725 #define FBC_BOUND(TEST_NON_UTF8, TEST_UV, TEST_UTF8) \
1727 FBC_UTF8(TEST_UV, TEST_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER), \
1728 TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER)
1730 #define FBC_BOUND_A(TEST_NON_UTF8) \
1732 FBC_UTF8_A(TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER), \
1733 TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER)
1735 #define FBC_NBOUND(TEST_NON_UTF8, TEST_UV, TEST_UTF8) \
1737 FBC_UTF8(TEST_UV, TEST_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT), \
1738 TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT)
1740 #define FBC_NBOUND_A(TEST_NON_UTF8) \
1742 FBC_UTF8_A(TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT), \
1743 TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT)
1745 /* Takes a pointer to an inversion list, a pointer to its corresponding
1746 * inversion map, and a code point, and returns the code point's value
1747 * according to the two arrays. It assumes that all code points have a value.
1748 * This is used as the base macro for macros for particular properties */
1749 #define _generic_GET_BREAK_VAL_CP(invlist, invmap, cp) \
1750 invmap[_invlist_search(invlist, cp)]
1752 /* Same as above, but takes begin, end ptrs to a UTF-8 encoded string instead
1753 * of a code point, returning the value for the first code point in the string.
1754 * And it takes the particular macro name that finds the desired value given a
1755 * code point. Merely convert the UTF-8 to code point and call the cp macro */
1756 #define _generic_GET_BREAK_VAL_UTF8(cp_macro, pos, strend) \
1757 (__ASSERT_(pos < strend) \
1758 /* Note assumes is valid UTF-8 */ \
1759 (cp_macro(utf8_to_uvchr_buf((pos), (strend), NULL))))
1761 /* Returns the GCB value for the input code point */
1762 #define getGCB_VAL_CP(cp) \
1763 _generic_GET_BREAK_VAL_CP( \
1765 Grapheme_Cluster_Break_invmap, \
1768 /* Returns the GCB value for the first code point in the UTF-8 encoded string
1769 * bounded by pos and strend */
1770 #define getGCB_VAL_UTF8(pos, strend) \
1771 _generic_GET_BREAK_VAL_UTF8(getGCB_VAL_CP, pos, strend)
1774 /* Returns the SB value for the input code point */
1775 #define getSB_VAL_CP(cp) \
1776 _generic_GET_BREAK_VAL_CP( \
1778 Sentence_Break_invmap, \
1781 /* Returns the SB value for the first code point in the UTF-8 encoded string
1782 * bounded by pos and strend */
1783 #define getSB_VAL_UTF8(pos, strend) \
1784 _generic_GET_BREAK_VAL_UTF8(getSB_VAL_CP, pos, strend)
1786 /* Returns the WB value for the input code point */
1787 #define getWB_VAL_CP(cp) \
1788 _generic_GET_BREAK_VAL_CP( \
1790 Word_Break_invmap, \
1793 /* Returns the WB value for the first code point in the UTF-8 encoded string
1794 * bounded by pos and strend */
1795 #define getWB_VAL_UTF8(pos, strend) \
1796 _generic_GET_BREAK_VAL_UTF8(getWB_VAL_CP, pos, strend)
1798 /* We know what class REx starts with. Try to find this position... */
1799 /* if reginfo->intuit, its a dryrun */
1800 /* annoyingly all the vars in this routine have different names from their counterparts
1801 in regmatch. /grrr */
1803 S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s,
1804 const char *strend, regmatch_info *reginfo)
1807 const I32 doevery = (prog->intflags & PREGf_SKIP) == 0;
1808 char *pat_string; /* The pattern's exactish string */
1809 char *pat_end; /* ptr to end char of pat_string */
1810 re_fold_t folder; /* Function for computing non-utf8 folds */
1811 const U8 *fold_array; /* array for folding ords < 256 */
1817 I32 tmp = 1; /* Scratch variable? */
1818 const bool utf8_target = reginfo->is_utf8_target;
1819 UV utf8_fold_flags = 0;
1820 const bool is_utf8_pat = reginfo->is_utf8_pat;
1821 bool to_complement = FALSE; /* Invert the result? Taking the xor of this
1822 with a result inverts that result, as 0^1 =
1824 _char_class_number classnum;
1826 RXi_GET_DECL(prog,progi);
1828 PERL_ARGS_ASSERT_FIND_BYCLASS;
1830 /* We know what class it must start with. */
1833 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
1837 REXEC_FBC_UTF8_CLASS_SCAN(
1838 reginclass(prog, c, (U8*)s, (U8*) strend, utf8_target));
1841 REXEC_FBC_CLASS_SCAN(REGINCLASS(prog, c, (U8*)s));
1846 if (tmp && (reginfo->intuit || regtry(reginfo, &s)))
1853 case EXACTFA_NO_TRIE: /* This node only generated for non-utf8 patterns */
1854 assert(! is_utf8_pat);
1857 if (is_utf8_pat || utf8_target) {
1858 utf8_fold_flags = FOLDEQ_UTF8_NOMIX_ASCII;
1859 goto do_exactf_utf8;
1861 fold_array = PL_fold_latin1; /* Latin1 folds are not affected by */
1862 folder = foldEQ_latin1; /* /a, except the sharp s one which */
1863 goto do_exactf_non_utf8; /* isn't dealt with by these */
1865 case EXACTF: /* This node only generated for non-utf8 patterns */
1866 assert(! is_utf8_pat);
1868 utf8_fold_flags = 0;
1869 goto do_exactf_utf8;
1871 fold_array = PL_fold;
1873 goto do_exactf_non_utf8;
1876 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
1877 if (is_utf8_pat || utf8_target || IN_UTF8_CTYPE_LOCALE) {
1878 utf8_fold_flags = FOLDEQ_LOCALE;
1879 goto do_exactf_utf8;
1881 fold_array = PL_fold_locale;
1882 folder = foldEQ_locale;
1883 goto do_exactf_non_utf8;
1887 utf8_fold_flags = FOLDEQ_S2_ALREADY_FOLDED;
1889 goto do_exactf_utf8;
1892 if (! utf8_target) { /* All code points in this node require
1893 UTF-8 to express. */
1896 utf8_fold_flags = FOLDEQ_LOCALE | FOLDEQ_S2_ALREADY_FOLDED
1897 | FOLDEQ_S2_FOLDS_SANE;
1898 goto do_exactf_utf8;
1901 if (is_utf8_pat || utf8_target) {
1902 utf8_fold_flags = is_utf8_pat ? FOLDEQ_S2_ALREADY_FOLDED : 0;
1903 goto do_exactf_utf8;
1906 /* Any 'ss' in the pattern should have been replaced by regcomp,
1907 * so we don't have to worry here about this single special case
1908 * in the Latin1 range */
1909 fold_array = PL_fold_latin1;
1910 folder = foldEQ_latin1;
1914 do_exactf_non_utf8: /* Neither pattern nor string are UTF8, and there
1915 are no glitches with fold-length differences
1916 between the target string and pattern */
1918 /* The idea in the non-utf8 EXACTF* cases is to first find the
1919 * first character of the EXACTF* node and then, if necessary,
1920 * case-insensitively compare the full text of the node. c1 is the
1921 * first character. c2 is its fold. This logic will not work for
1922 * Unicode semantics and the german sharp ss, which hence should
1923 * not be compiled into a node that gets here. */
1924 pat_string = STRING(c);
1925 ln = STR_LEN(c); /* length to match in octets/bytes */
1927 /* We know that we have to match at least 'ln' bytes (which is the
1928 * same as characters, since not utf8). If we have to match 3
1929 * characters, and there are only 2 availabe, we know without
1930 * trying that it will fail; so don't start a match past the
1931 * required minimum number from the far end */
1932 e = HOP3c(strend, -((SSize_t)ln), s);
1934 if (reginfo->intuit && e < s) {
1935 e = s; /* Due to minlen logic of intuit() */
1939 c2 = fold_array[c1];
1940 if (c1 == c2) { /* If char and fold are the same */
1941 REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1);
1944 REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1 || *(U8*)s == c2);
1952 /* If one of the operands is in utf8, we can't use the simpler folding
1953 * above, due to the fact that many different characters can have the
1954 * same fold, or portion of a fold, or different- length fold */
1955 pat_string = STRING(c);
1956 ln = STR_LEN(c); /* length to match in octets/bytes */
1957 pat_end = pat_string + ln;
1958 lnc = is_utf8_pat /* length to match in characters */
1959 ? utf8_length((U8 *) pat_string, (U8 *) pat_end)
1962 /* We have 'lnc' characters to match in the pattern, but because of
1963 * multi-character folding, each character in the target can match
1964 * up to 3 characters (Unicode guarantees it will never exceed
1965 * this) if it is utf8-encoded; and up to 2 if not (based on the
1966 * fact that the Latin 1 folds are already determined, and the
1967 * only multi-char fold in that range is the sharp-s folding to
1968 * 'ss'. Thus, a pattern character can match as little as 1/3 of a
1969 * string character. Adjust lnc accordingly, rounding up, so that
1970 * if we need to match at least 4+1/3 chars, that really is 5. */
1971 expansion = (utf8_target) ? UTF8_MAX_FOLD_CHAR_EXPAND : 2;
1972 lnc = (lnc + expansion - 1) / expansion;
1974 /* As in the non-UTF8 case, if we have to match 3 characters, and
1975 * only 2 are left, it's guaranteed to fail, so don't start a
1976 * match that would require us to go beyond the end of the string
1978 e = HOP3c(strend, -((SSize_t)lnc), s);
1980 if (reginfo->intuit && e < s) {
1981 e = s; /* Due to minlen logic of intuit() */
1984 /* XXX Note that we could recalculate e to stop the loop earlier,
1985 * as the worst case expansion above will rarely be met, and as we
1986 * go along we would usually find that e moves further to the left.
1987 * This would happen only after we reached the point in the loop
1988 * where if there were no expansion we should fail. Unclear if
1989 * worth the expense */
1992 char *my_strend= (char *)strend;
1993 if (foldEQ_utf8_flags(s, &my_strend, 0, utf8_target,
1994 pat_string, NULL, ln, is_utf8_pat, utf8_fold_flags)
1995 && (reginfo->intuit || regtry(reginfo, &s)) )
1999 s += (utf8_target) ? UTF8SKIP(s) : 1;
2005 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
2006 if (FLAGS(c) != TRADITIONAL_BOUND) {
2007 if (! IN_UTF8_CTYPE_LOCALE) {
2008 Perl_ck_warner(aTHX_ packWARN(WARN_LOCALE),
2009 B_ON_NON_UTF8_LOCALE_IS_WRONG);
2014 FBC_BOUND(isWORDCHAR_LC, isWORDCHAR_LC_uvchr, isWORDCHAR_LC_utf8);
2018 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
2019 if (FLAGS(c) != TRADITIONAL_BOUND) {
2020 if (! IN_UTF8_CTYPE_LOCALE) {
2021 Perl_ck_warner(aTHX_ packWARN(WARN_LOCALE),
2022 B_ON_NON_UTF8_LOCALE_IS_WRONG);
2027 FBC_NBOUND(isWORDCHAR_LC, isWORDCHAR_LC_uvchr, isWORDCHAR_LC_utf8);
2030 case BOUND: /* regcomp.c makes sure that this only has the traditional \b
2032 assert(FLAGS(c) == TRADITIONAL_BOUND);
2034 FBC_BOUND(isWORDCHAR, isWORDCHAR_uni, isWORDCHAR_utf8);
2037 case BOUNDA: /* regcomp.c makes sure that this only has the traditional \b
2039 assert(FLAGS(c) == TRADITIONAL_BOUND);
2041 FBC_BOUND_A(isWORDCHAR_A);
2044 case NBOUND: /* regcomp.c makes sure that this only has the traditional \b
2046 assert(FLAGS(c) == TRADITIONAL_BOUND);
2048 FBC_NBOUND(isWORDCHAR, isWORDCHAR_uni, isWORDCHAR_utf8);
2051 case NBOUNDA: /* regcomp.c makes sure that this only has the traditional \b
2053 assert(FLAGS(c) == TRADITIONAL_BOUND);
2055 FBC_NBOUND_A(isWORDCHAR_A);
2059 if ((bound_type) FLAGS(c) == TRADITIONAL_BOUND) {
2060 FBC_NBOUND(isWORDCHAR_L1, isWORDCHAR_uni, isWORDCHAR_utf8);
2071 switch((bound_type) FLAGS(c)) {
2072 case TRADITIONAL_BOUND:
2073 FBC_BOUND(isWORDCHAR_L1, isWORDCHAR_uni, isWORDCHAR_utf8);
2076 if (s == reginfo->strbeg) { /* GCB always matches at begin and
2078 if (to_complement ^ cBOOL(reginfo->intuit
2079 || regtry(reginfo, &s)))
2083 s += (utf8_target) ? UTF8SKIP(s) : 1;
2087 GCB_enum before = getGCB_VAL_UTF8(
2089 (U8*)(reginfo->strbeg)),
2090 (U8*) reginfo->strend);
2091 while (s < strend) {
2092 GCB_enum after = getGCB_VAL_UTF8((U8*) s,
2093 (U8*) reginfo->strend);
2094 if (to_complement ^ isGCB(before, after)) {
2095 if (reginfo->intuit || regtry(reginfo, &s)) {
2103 else { /* Not utf8. Everything is a GCB except between CR and
2105 while (s < strend) {
2106 if (to_complement ^ (UCHARAT(s - 1) != '\r'
2107 || UCHARAT(s) != '\n'))
2109 if (reginfo->intuit || regtry(reginfo, &s)) {
2117 if (to_complement ^ cBOOL(reginfo->intuit || regtry(reginfo, &s))) {
2123 if (s == reginfo->strbeg) { /* SB always matches at beginning */
2125 ^ cBOOL(reginfo->intuit || regtry(reginfo, &s)))
2130 /* Didn't match. Go try at the next position */
2131 s += (utf8_target) ? UTF8SKIP(s) : 1;
2135 SB_enum before = getSB_VAL_UTF8(reghop3((U8*)s,
2137 (U8*)(reginfo->strbeg)),
2138 (U8*) reginfo->strend);
2139 while (s < strend) {
2140 SB_enum after = getSB_VAL_UTF8((U8*) s,
2141 (U8*) reginfo->strend);
2142 if (to_complement ^ isSB(before,
2144 (U8*) reginfo->strbeg,
2146 (U8*) reginfo->strend,
2149 if (reginfo->intuit || regtry(reginfo, &s)) {
2157 else { /* Not utf8. */
2158 SB_enum before = getSB_VAL_CP((U8) *(s -1));
2159 while (s < strend) {
2160 SB_enum after = getSB_VAL_CP((U8) *s);
2161 if (to_complement ^ isSB(before,
2163 (U8*) reginfo->strbeg,
2165 (U8*) reginfo->strend,
2168 if (reginfo->intuit || regtry(reginfo, &s)) {
2177 /* Here are at the final position in the target string. The SB
2178 * value is always true here, so matches, depending on other
2180 if (to_complement ^ cBOOL(reginfo->intuit
2181 || regtry(reginfo, &s)))
2189 if (s == reginfo->strbeg) {
2190 if (to_complement ^ cBOOL(reginfo->intuit
2191 || regtry(reginfo, &s)))
2195 s += (utf8_target) ? UTF8SKIP(s) : 1;
2199 /* We are at a boundary between char_sub_0 and char_sub_1.
2200 * We also keep track of the value for char_sub_-1 as we
2201 * loop through the line. Context may be needed to make a
2202 * determination, and if so, this can save having to
2204 WB_enum previous = WB_UNKNOWN;
2205 WB_enum before = getWB_VAL_UTF8(
2208 (U8*)(reginfo->strbeg)),
2209 (U8*) reginfo->strend);
2210 while (s < strend) {
2211 WB_enum after = getWB_VAL_UTF8((U8*) s,
2212 (U8*) reginfo->strend);
2213 if (to_complement ^ isWB(previous,
2216 (U8*) reginfo->strbeg,
2218 (U8*) reginfo->strend,
2221 if (reginfo->intuit || regtry(reginfo, &s)) {
2230 else { /* Not utf8. */
2231 WB_enum previous = WB_UNKNOWN;
2232 WB_enum before = getWB_VAL_CP((U8) *(s -1));
2233 while (s < strend) {
2234 WB_enum after = getWB_VAL_CP((U8) *s);
2235 if (to_complement ^ isWB(previous,
2238 (U8*) reginfo->strbeg,
2240 (U8*) reginfo->strend,
2243 if (reginfo->intuit || regtry(reginfo, &s)) {
2253 if (to_complement ^ cBOOL(reginfo->intuit
2254 || regtry(reginfo, &s)))
2264 REXEC_FBC_CSCAN(is_LNBREAK_utf8_safe(s, strend),
2265 is_LNBREAK_latin1_safe(s, strend)
2269 /* The argument to all the POSIX node types is the class number to pass to
2270 * _generic_isCC() to build a mask for searching in PL_charclass[] */
2277 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
2278 REXEC_FBC_CSCAN(to_complement ^ cBOOL(isFOO_utf8_lc(FLAGS(c), (U8 *) s)),
2279 to_complement ^ cBOOL(isFOO_lc(FLAGS(c), *s)));
2294 /* The complement of something that matches only ASCII matches all
2295 * non-ASCII, plus everything in ASCII that isn't in the class. */
2296 REXEC_FBC_UTF8_CLASS_SCAN(! isASCII_utf8(s)
2297 || ! _generic_isCC_A(*s, FLAGS(c)));
2306 /* Don't need to worry about utf8, as it can match only a single
2307 * byte invariant character. */
2308 REXEC_FBC_CLASS_SCAN(
2309 to_complement ^ cBOOL(_generic_isCC_A(*s, FLAGS(c))));
2317 if (! utf8_target) {
2318 REXEC_FBC_CLASS_SCAN(to_complement ^ cBOOL(_generic_isCC(*s,
2324 classnum = (_char_class_number) FLAGS(c);
2325 if (classnum < _FIRST_NON_SWASH_CC) {
2326 while (s < strend) {
2328 /* We avoid loading in the swash as long as possible, but
2329 * should we have to, we jump to a separate loop. This
2330 * extra 'if' statement is what keeps this code from being
2331 * just a call to REXEC_FBC_UTF8_CLASS_SCAN() */
2332 if (UTF8_IS_ABOVE_LATIN1(*s)) {
2333 goto found_above_latin1;
2335 if ((UTF8_IS_INVARIANT(*s)
2336 && to_complement ^ cBOOL(_generic_isCC((U8) *s,
2338 || (UTF8_IS_DOWNGRADEABLE_START(*s)
2339 && to_complement ^ cBOOL(
2340 _generic_isCC(TWO_BYTE_UTF8_TO_NATIVE(*s,
2344 if (tmp && (reginfo->intuit || regtry(reginfo, &s)))
2356 else switch (classnum) { /* These classes are implemented as
2358 case _CC_ENUM_SPACE:
2359 REXEC_FBC_UTF8_CLASS_SCAN(
2360 to_complement ^ cBOOL(isSPACE_utf8(s)));
2363 case _CC_ENUM_BLANK:
2364 REXEC_FBC_UTF8_CLASS_SCAN(
2365 to_complement ^ cBOOL(isBLANK_utf8(s)));
2368 case _CC_ENUM_XDIGIT:
2369 REXEC_FBC_UTF8_CLASS_SCAN(
2370 to_complement ^ cBOOL(isXDIGIT_utf8(s)));
2373 case _CC_ENUM_VERTSPACE:
2374 REXEC_FBC_UTF8_CLASS_SCAN(
2375 to_complement ^ cBOOL(isVERTWS_utf8(s)));
2378 case _CC_ENUM_CNTRL:
2379 REXEC_FBC_UTF8_CLASS_SCAN(
2380 to_complement ^ cBOOL(isCNTRL_utf8(s)));
2384 Perl_croak(aTHX_ "panic: find_byclass() node %d='%s' has an unexpected character class '%d'", OP(c), PL_reg_name[OP(c)], classnum);
2385 NOT_REACHED; /* NOTREACHED */
2390 found_above_latin1: /* Here we have to load a swash to get the result
2391 for the current code point */
2392 if (! PL_utf8_swash_ptrs[classnum]) {
2393 U8 flags = _CORE_SWASH_INIT_ACCEPT_INVLIST;
2394 PL_utf8_swash_ptrs[classnum] =
2395 _core_swash_init("utf8",
2398 PL_XPosix_ptrs[classnum], &flags);
2401 /* This is a copy of the loop above for swash classes, though using the
2402 * FBC macro instead of being expanded out. Since we've loaded the
2403 * swash, we don't have to check for that each time through the loop */
2404 REXEC_FBC_UTF8_CLASS_SCAN(
2405 to_complement ^ cBOOL(_generic_utf8(
2408 swash_fetch(PL_utf8_swash_ptrs[classnum],
2416 /* what trie are we using right now */
2417 reg_ac_data *aho = (reg_ac_data*)progi->data->data[ ARG( c ) ];
2418 reg_trie_data *trie = (reg_trie_data*)progi->data->data[ aho->trie ];
2419 HV *widecharmap = MUTABLE_HV(progi->data->data[ aho->trie + 1 ]);
2421 const char *last_start = strend - trie->minlen;
2423 const char *real_start = s;
2425 STRLEN maxlen = trie->maxlen;
2427 U8 **points; /* map of where we were in the input string
2428 when reading a given char. For ASCII this
2429 is unnecessary overhead as the relationship
2430 is always 1:1, but for Unicode, especially
2431 case folded Unicode this is not true. */
2432 U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
2436 GET_RE_DEBUG_FLAGS_DECL;
2438 /* We can't just allocate points here. We need to wrap it in
2439 * an SV so it gets freed properly if there is a croak while
2440 * running the match */
2443 sv_points=newSV(maxlen * sizeof(U8 *));
2444 SvCUR_set(sv_points,
2445 maxlen * sizeof(U8 *));
2446 SvPOK_on(sv_points);
2447 sv_2mortal(sv_points);
2448 points=(U8**)SvPV_nolen(sv_points );
2449 if ( trie_type != trie_utf8_fold
2450 && (trie->bitmap || OP(c)==AHOCORASICKC) )
2453 bitmap=(U8*)trie->bitmap;
2455 bitmap=(U8*)ANYOF_BITMAP(c);
2457 /* this is the Aho-Corasick algorithm modified a touch
2458 to include special handling for long "unknown char" sequences.
2459 The basic idea being that we use AC as long as we are dealing
2460 with a possible matching char, when we encounter an unknown char
2461 (and we have not encountered an accepting state) we scan forward
2462 until we find a legal starting char.
2463 AC matching is basically that of trie matching, except that when
2464 we encounter a failing transition, we fall back to the current
2465 states "fail state", and try the current char again, a process
2466 we repeat until we reach the root state, state 1, or a legal
2467 transition. If we fail on the root state then we can either
2468 terminate if we have reached an accepting state previously, or
2469 restart the entire process from the beginning if we have not.
2472 while (s <= last_start) {
2473 const U32 uniflags = UTF8_ALLOW_DEFAULT;
2481 U8 *uscan = (U8*)NULL;
2482 U8 *leftmost = NULL;
2484 U32 accepted_word= 0;
2488 while ( state && uc <= (U8*)strend ) {
2490 U32 word = aho->states[ state ].wordnum;
2494 DEBUG_TRIE_EXECUTE_r(
2495 if ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
2496 dump_exec_pos( (char *)uc, c, strend, real_start,
2497 (char *)uc, utf8_target );
2498 PerlIO_printf( Perl_debug_log,
2499 " Scanning for legal start char...\n");
2503 while ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
2507 while ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
2513 if (uc >(U8*)last_start) break;
2517 U8 *lpos= points[ (pointpos - trie->wordinfo[word].len) % maxlen ];
2518 if (!leftmost || lpos < leftmost) {
2519 DEBUG_r(accepted_word=word);
2525 points[pointpos++ % maxlen]= uc;
2526 if (foldlen || uc < (U8*)strend) {
2527 REXEC_TRIE_READ_CHAR(trie_type, trie,
2529 uscan, len, uvc, charid, foldlen,
2531 DEBUG_TRIE_EXECUTE_r({
2532 dump_exec_pos( (char *)uc, c, strend,
2533 real_start, s, utf8_target);
2534 PerlIO_printf(Perl_debug_log,
2535 " Charid:%3u CP:%4"UVxf" ",
2547 word = aho->states[ state ].wordnum;
2549 base = aho->states[ state ].trans.base;
2551 DEBUG_TRIE_EXECUTE_r({
2553 dump_exec_pos( (char *)uc, c, strend, real_start,
2555 PerlIO_printf( Perl_debug_log,
2556 "%sState: %4"UVxf", word=%"UVxf,
2557 failed ? " Fail transition to " : "",
2558 (UV)state, (UV)word);
2564 ( ((offset = base + charid
2565 - 1 - trie->uniquecharcount)) >= 0)
2566 && ((U32)offset < trie->lasttrans)
2567 && trie->trans[offset].check == state
2568 && (tmp=trie->trans[offset].next))
2570 DEBUG_TRIE_EXECUTE_r(
2571 PerlIO_printf( Perl_debug_log," - legal\n"));
2576 DEBUG_TRIE_EXECUTE_r(
2577 PerlIO_printf( Perl_debug_log," - fail\n"));
2579 state = aho->fail[state];
2583 /* we must be accepting here */
2584 DEBUG_TRIE_EXECUTE_r(
2585 PerlIO_printf( Perl_debug_log," - accepting\n"));
2594 if (!state) state = 1;
2597 if ( aho->states[ state ].wordnum ) {
2598 U8 *lpos = points[ (pointpos - trie->wordinfo[aho->states[ state ].wordnum].len) % maxlen ];
2599 if (!leftmost || lpos < leftmost) {
2600 DEBUG_r(accepted_word=aho->states[ state ].wordnum);
2605 s = (char*)leftmost;
2606 DEBUG_TRIE_EXECUTE_r({
2608 Perl_debug_log,"Matches word #%"UVxf" at position %"IVdf". Trying full pattern...\n",
2609 (UV)accepted_word, (IV)(s - real_start)
2612 if (reginfo->intuit || regtry(reginfo, &s)) {
2618 DEBUG_TRIE_EXECUTE_r({
2619 PerlIO_printf( Perl_debug_log,"Pattern failed. Looking for new start point...\n");
2622 DEBUG_TRIE_EXECUTE_r(
2623 PerlIO_printf( Perl_debug_log,"No match.\n"));
2632 Perl_croak(aTHX_ "panic: unknown regstclass %d", (int)OP(c));
2639 /* set RX_SAVED_COPY, RX_SUBBEG etc.
2640 * flags have same meanings as with regexec_flags() */
2643 S_reg_set_capture_string(pTHX_ REGEXP * const rx,
2650 struct regexp *const prog = ReANY(rx);
2652 if (flags & REXEC_COPY_STR) {
2656 PerlIO_printf(Perl_debug_log,
2657 "Copy on write: regexp capture, type %d\n",
2660 /* Create a new COW SV to share the match string and store
2661 * in saved_copy, unless the current COW SV in saved_copy
2662 * is valid and suitable for our purpose */
2663 if (( prog->saved_copy
2664 && SvIsCOW(prog->saved_copy)
2665 && SvPOKp(prog->saved_copy)
2668 && SvPVX(sv) == SvPVX(prog->saved_copy)))
2670 /* just reuse saved_copy SV */
2671 if (RXp_MATCH_COPIED(prog)) {
2672 Safefree(prog->subbeg);
2673 RXp_MATCH_COPIED_off(prog);
2677 /* create new COW SV to share string */
2678 RX_MATCH_COPY_FREE(rx);
2679 prog->saved_copy = sv_setsv_cow(prog->saved_copy, sv);
2681 prog->subbeg = (char *)SvPVX_const(prog->saved_copy);
2682 assert (SvPOKp(prog->saved_copy));
2683 prog->sublen = strend - strbeg;
2684 prog->suboffset = 0;
2685 prog->subcoffset = 0;
2690 SSize_t max = strend - strbeg;
2693 if ( (flags & REXEC_COPY_SKIP_POST)
2694 && !(prog->extflags & RXf_PMf_KEEPCOPY) /* //p */
2695 && !(PL_sawampersand & SAWAMPERSAND_RIGHT)
2696 ) { /* don't copy $' part of string */
2699 /* calculate the right-most part of the string covered
2700 * by a capture. Due to look-ahead, this may be to
2701 * the right of $&, so we have to scan all captures */
2702 while (n <= prog->lastparen) {
2703 if (prog->offs[n].end > max)
2704 max = prog->offs[n].end;
2708 max = (PL_sawampersand & SAWAMPERSAND_LEFT)
2709 ? prog->offs[0].start
2711 assert(max >= 0 && max <= strend - strbeg);
2714 if ( (flags & REXEC_COPY_SKIP_PRE)
2715 && !(prog->extflags & RXf_PMf_KEEPCOPY) /* //p */
2716 && !(PL_sawampersand & SAWAMPERSAND_LEFT)
2717 ) { /* don't copy $` part of string */
2720 /* calculate the left-most part of the string covered
2721 * by a capture. Due to look-behind, this may be to
2722 * the left of $&, so we have to scan all captures */
2723 while (min && n <= prog->lastparen) {
2724 if ( prog->offs[n].start != -1
2725 && prog->offs[n].start < min)
2727 min = prog->offs[n].start;
2731 if ((PL_sawampersand & SAWAMPERSAND_RIGHT)
2732 && min > prog->offs[0].end
2734 min = prog->offs[0].end;
2738 assert(min >= 0 && min <= max && min <= strend - strbeg);
2741 if (RX_MATCH_COPIED(rx)) {
2742 if (sublen > prog->sublen)
2744 (char*)saferealloc(prog->subbeg, sublen+1);
2747 prog->subbeg = (char*)safemalloc(sublen+1);
2748 Copy(strbeg + min, prog->subbeg, sublen, char);
2749 prog->subbeg[sublen] = '\0';
2750 prog->suboffset = min;
2751 prog->sublen = sublen;
2752 RX_MATCH_COPIED_on(rx);
2754 prog->subcoffset = prog->suboffset;
2755 if (prog->suboffset && utf8_target) {
2756 /* Convert byte offset to chars.
2757 * XXX ideally should only compute this if @-/@+
2758 * has been seen, a la PL_sawampersand ??? */
2760 /* If there's a direct correspondence between the
2761 * string which we're matching and the original SV,
2762 * then we can use the utf8 len cache associated with
2763 * the SV. In particular, it means that under //g,
2764 * sv_pos_b2u() will use the previously cached
2765 * position to speed up working out the new length of
2766 * subcoffset, rather than counting from the start of
2767 * the string each time. This stops
2768 * $x = "\x{100}" x 1E6; 1 while $x =~ /(.)/g;
2769 * from going quadratic */
2770 if (SvPOKp(sv) && SvPVX(sv) == strbeg)
2771 prog->subcoffset = sv_pos_b2u_flags(sv, prog->subcoffset,
2772 SV_GMAGIC|SV_CONST_RETURN);
2774 prog->subcoffset = utf8_length((U8*)strbeg,
2775 (U8*)(strbeg+prog->suboffset));
2779 RX_MATCH_COPY_FREE(rx);
2780 prog->subbeg = strbeg;
2781 prog->suboffset = 0;
2782 prog->subcoffset = 0;
2783 prog->sublen = strend - strbeg;
2791 - regexec_flags - match a regexp against a string
2794 Perl_regexec_flags(pTHX_ REGEXP * const rx, char *stringarg, char *strend,
2795 char *strbeg, SSize_t minend, SV *sv, void *data, U32 flags)
2796 /* stringarg: the point in the string at which to begin matching */
2797 /* strend: pointer to null at end of string */
2798 /* strbeg: real beginning of string */
2799 /* minend: end of match must be >= minend bytes after stringarg. */
2800 /* sv: SV being matched: only used for utf8 flag, pos() etc; string
2801 * itself is accessed via the pointers above */
2802 /* data: May be used for some additional optimizations.
2803 Currently unused. */
2804 /* flags: For optimizations. See REXEC_* in regexp.h */
2807 struct regexp *const prog = ReANY(rx);
2811 SSize_t minlen; /* must match at least this many chars */
2812 SSize_t dontbother = 0; /* how many characters not to try at end */
2813 const bool utf8_target = cBOOL(DO_UTF8(sv));
2815 RXi_GET_DECL(prog,progi);
2816 regmatch_info reginfo_buf; /* create some info to pass to regtry etc */
2817 regmatch_info *const reginfo = ®info_buf;
2818 regexp_paren_pair *swap = NULL;
2820 GET_RE_DEBUG_FLAGS_DECL;
2822 PERL_ARGS_ASSERT_REGEXEC_FLAGS;
2823 PERL_UNUSED_ARG(data);
2825 /* Be paranoid... */
2827 Perl_croak(aTHX_ "NULL regexp parameter");
2831 debug_start_match(rx, utf8_target, stringarg, strend,
2835 startpos = stringarg;
2837 if (prog->intflags & PREGf_GPOS_SEEN) {
2840 /* set reginfo->ganch, the position where \G can match */
2843 (flags & REXEC_IGNOREPOS)
2844 ? stringarg /* use start pos rather than pos() */
2845 : ((mg = mg_find_mglob(sv)) && mg->mg_len >= 0)
2846 /* Defined pos(): */
2847 ? strbeg + MgBYTEPOS(mg, sv, strbeg, strend-strbeg)
2848 : strbeg; /* pos() not defined; use start of string */
2850 DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
2851 "GPOS ganch set to strbeg[%"IVdf"]\n", (IV)(reginfo->ganch - strbeg)));
2853 /* in the presence of \G, we may need to start looking earlier in
2854 * the string than the suggested start point of stringarg:
2855 * if prog->gofs is set, then that's a known, fixed minimum
2858 * /ab|c\G/: gofs = 1
2859 * or if the minimum offset isn't known, then we have to go back
2860 * to the start of the string, e.g. /w+\G/
2863 if (prog->intflags & PREGf_ANCH_GPOS) {
2864 startpos = reginfo->ganch - prog->gofs;
2866 ((flags & REXEC_FAIL_ON_UNDERFLOW) ? stringarg : strbeg))
2868 DEBUG_r(PerlIO_printf(Perl_debug_log,
2869 "fail: ganch-gofs before earliest possible start\n"));
2873 else if (prog->gofs) {
2874 if (startpos - prog->gofs < strbeg)
2877 startpos -= prog->gofs;
2879 else if (prog->intflags & PREGf_GPOS_FLOAT)
2883 minlen = prog->minlen;
2884 if ((startpos + minlen) > strend || startpos < strbeg) {
2885 DEBUG_r(PerlIO_printf(Perl_debug_log,
2886 "Regex match can't succeed, so not even tried\n"));
2890 /* at the end of this function, we'll do a LEAVE_SCOPE(oldsave),
2891 * which will call destuctors to reset PL_regmatch_state, free higher
2892 * PL_regmatch_slabs, and clean up regmatch_info_aux and
2893 * regmatch_info_aux_eval */
2895 oldsave = PL_savestack_ix;
2899 if ((prog->extflags & RXf_USE_INTUIT)
2900 && !(flags & REXEC_CHECKED))
2902 s = re_intuit_start(rx, sv, strbeg, startpos, strend,
2907 if (prog->extflags & RXf_CHECK_ALL) {
2908 /* we can match based purely on the result of INTUIT.
2909 * Set up captures etc just for $& and $-[0]
2910 * (an intuit-only match wont have $1,$2,..) */
2911 assert(!prog->nparens);
2913 /* s/// doesn't like it if $& is earlier than where we asked it to
2914 * start searching (which can happen on something like /.\G/) */
2915 if ( (flags & REXEC_FAIL_ON_UNDERFLOW)
2918 /* this should only be possible under \G */
2919 assert(prog->intflags & PREGf_GPOS_SEEN);
2920 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
2921 "matched, but failing for REXEC_FAIL_ON_UNDERFLOW\n"));
2925 /* match via INTUIT shouldn't have any captures.
2926 * Let @-, @+, $^N know */
2927 prog->lastparen = prog->lastcloseparen = 0;
2928 RX_MATCH_UTF8_set(rx, utf8_target);
2929 prog->offs[0].start = s - strbeg;
2930 prog->offs[0].end = utf8_target
2931 ? (char*)utf8_hop((U8*)s, prog->minlenret) - strbeg
2932 : s - strbeg + prog->minlenret;
2933 if ( !(flags & REXEC_NOT_FIRST) )
2934 S_reg_set_capture_string(aTHX_ rx,
2936 sv, flags, utf8_target);
2942 multiline = prog->extflags & RXf_PMf_MULTILINE;
2944 if (strend - s < (minlen+(prog->check_offset_min<0?prog->check_offset_min:0))) {
2945 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
2946 "String too short [regexec_flags]...\n"));
2950 /* Check validity of program. */
2951 if (UCHARAT(progi->program) != REG_MAGIC) {
2952 Perl_croak(aTHX_ "corrupted regexp program");
2955 RX_MATCH_TAINTED_off(rx);
2956 RX_MATCH_UTF8_set(rx, utf8_target);
2958 reginfo->prog = rx; /* Yes, sorry that this is confusing. */
2959 reginfo->intuit = 0;
2960 reginfo->is_utf8_target = cBOOL(utf8_target);
2961 reginfo->is_utf8_pat = cBOOL(RX_UTF8(rx));
2962 reginfo->warned = FALSE;
2963 reginfo->strbeg = strbeg;
2965 reginfo->poscache_maxiter = 0; /* not yet started a countdown */
2966 reginfo->strend = strend;
2967 /* see how far we have to get to not match where we matched before */
2968 reginfo->till = stringarg + minend;
2970 if (prog->extflags & RXf_EVAL_SEEN && SvPADTMP(sv)) {
2971 /* SAVEFREESV, not sv_mortalcopy, as this SV must last until after
2972 S_cleanup_regmatch_info_aux has executed (registered by
2973 SAVEDESTRUCTOR_X below). S_cleanup_regmatch_info_aux modifies
2974 magic belonging to this SV.
2975 Not newSVsv, either, as it does not COW.
2977 reginfo->sv = newSV(0);
2978 SvSetSV_nosteal(reginfo->sv, sv);
2979 SAVEFREESV(reginfo->sv);
2982 /* reserve next 2 or 3 slots in PL_regmatch_state:
2983 * slot N+0: may currently be in use: skip it
2984 * slot N+1: use for regmatch_info_aux struct
2985 * slot N+2: use for regmatch_info_aux_eval struct if we have (?{})'s
2986 * slot N+3: ready for use by regmatch()
2990 regmatch_state *old_regmatch_state;
2991 regmatch_slab *old_regmatch_slab;
2992 int i, max = (prog->extflags & RXf_EVAL_SEEN) ? 2 : 1;
2994 /* on first ever match, allocate first slab */
2995 if (!PL_regmatch_slab) {
2996 Newx(PL_regmatch_slab, 1, regmatch_slab);
2997 PL_regmatch_slab->prev = NULL;
2998 PL_regmatch_slab->next = NULL;
2999 PL_regmatch_state = SLAB_FIRST(PL_regmatch_slab);
3002 old_regmatch_state = PL_regmatch_state;
3003 old_regmatch_slab = PL_regmatch_slab;
3005 for (i=0; i <= max; i++) {
3007 reginfo->info_aux = &(PL_regmatch_state->u.info_aux);
3009 reginfo->info_aux_eval =
3010 reginfo->info_aux->info_aux_eval =
3011 &(PL_regmatch_state->u.info_aux_eval);
3013 if (++PL_regmatch_state > SLAB_LAST(PL_regmatch_slab))
3014 PL_regmatch_state = S_push_slab(aTHX);
3017 /* note initial PL_regmatch_state position; at end of match we'll
3018 * pop back to there and free any higher slabs */
3020 reginfo->info_aux->old_regmatch_state = old_regmatch_state;
3021 reginfo->info_aux->old_regmatch_slab = old_regmatch_slab;
3022 reginfo->info_aux->poscache = NULL;
3024 SAVEDESTRUCTOR_X(S_cleanup_regmatch_info_aux, reginfo->info_aux);
3026 if ((prog->extflags & RXf_EVAL_SEEN))
3027 S_setup_eval_state(aTHX_ reginfo);
3029 reginfo->info_aux_eval = reginfo->info_aux->info_aux_eval = NULL;
3032 /* If there is a "must appear" string, look for it. */
3034 if (PL_curpm && (PM_GETRE(PL_curpm) == rx)) {
3035 /* We have to be careful. If the previous successful match
3036 was from this regex we don't want a subsequent partially
3037 successful match to clobber the old results.
3038 So when we detect this possibility we add a swap buffer
3039 to the re, and switch the buffer each match. If we fail,
3040 we switch it back; otherwise we leave it swapped.
3043 /* do we need a save destructor here for eval dies? */
3044 Newxz(prog->offs, (prog->nparens + 1), regexp_paren_pair);
3045 DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
3046 "rex=0x%"UVxf" saving offs: orig=0x%"UVxf" new=0x%"UVxf"\n",
3053 /* Simplest case: anchored match need be tried only once, or with
3054 * MBOL, only at the beginning of each line.
3056 * Note that /.*.../ sets PREGf_IMPLICIT|MBOL, while /.*.../s sets
3057 * PREGf_IMPLICIT|SBOL. The idea is that with /.*.../s, if it doesn't
3058 * match at the start of the string then it won't match anywhere else
3059 * either; while with /.*.../, if it doesn't match at the beginning,
3060 * the earliest it could match is at the start of the next line */
3062 if (prog->intflags & (PREGf_ANCH & ~PREGf_ANCH_GPOS)) {
3065 if (regtry(reginfo, &s))
3068 if (!(prog->intflags & PREGf_ANCH_MBOL))
3071 /* didn't match at start, try at other newline positions */
3074 dontbother = minlen - 1;
3075 end = HOP3c(strend, -dontbother, strbeg) - 1;
3077 /* skip to next newline */
3079 while (s <= end) { /* note it could be possible to match at the end of the string */
3080 /* NB: newlines are the same in unicode as they are in latin */
3083 if (prog->check_substr || prog->check_utf8) {
3084 /* note that with PREGf_IMPLICIT, intuit can only fail
3085 * or return the start position, so it's of limited utility.
3086 * Nevertheless, I made the decision that the potential for
3087 * quick fail was still worth it - DAPM */
3088 s = re_intuit_start(rx, sv, strbeg, s, strend, flags, NULL);
3092 if (regtry(reginfo, &s))
3096 } /* end anchored search */
3098 if (prog->intflags & PREGf_ANCH_GPOS)
3100 /* PREGf_ANCH_GPOS should never be true if PREGf_GPOS_SEEN is not true */
3101 assert(prog->intflags & PREGf_GPOS_SEEN);
3102 /* For anchored \G, the only position it can match from is
3103 * (ganch-gofs); we already set startpos to this above; if intuit
3104 * moved us on from there, we can't possibly succeed */
3105 assert(startpos == reginfo->ganch - prog->gofs);
3106 if (s == startpos && regtry(reginfo, &s))
3111 /* Messy cases: unanchored match. */
3112 if ((prog->anchored_substr || prog->anchored_utf8) && prog->intflags & PREGf_SKIP) {
3113 /* we have /x+whatever/ */
3114 /* it must be a one character string (XXXX Except is_utf8_pat?) */
3120 if (! prog->anchored_utf8) {
3121 to_utf8_substr(prog);
3123 ch = SvPVX_const(prog->anchored_utf8)[0];
3126 DEBUG_EXECUTE_r( did_match = 1 );
3127 if (regtry(reginfo, &s)) goto got_it;
3129 while (s < strend && *s == ch)
3136 if (! prog->anchored_substr) {
3137 if (! to_byte_substr(prog)) {
3138 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3141 ch = SvPVX_const(prog->anchored_substr)[0];
3144 DEBUG_EXECUTE_r( did_match = 1 );
3145 if (regtry(reginfo, &s)) goto got_it;
3147 while (s < strend && *s == ch)
3152 DEBUG_EXECUTE_r(if (!did_match)
3153 PerlIO_printf(Perl_debug_log,
3154 "Did not find anchored character...\n")
3157 else if (prog->anchored_substr != NULL
3158 || prog->anchored_utf8 != NULL
3159 || ((prog->float_substr != NULL || prog->float_utf8 != NULL)
3160 && prog->float_max_offset < strend - s)) {
3165 char *last1; /* Last position checked before */
3169 if (prog->anchored_substr || prog->anchored_utf8) {
3171 if (! prog->anchored_utf8) {
3172 to_utf8_substr(prog);
3174 must = prog->anchored_utf8;
3177 if (! prog->anchored_substr) {
3178 if (! to_byte_substr(prog)) {
3179 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3182 must = prog->anchored_substr;
3184 back_max = back_min = prog->anchored_offset;
3187 if (! prog->float_utf8) {
3188 to_utf8_substr(prog);
3190 must = prog->float_utf8;
3193 if (! prog->float_substr) {
3194 if (! to_byte_substr(prog)) {
3195 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3198 must = prog->float_substr;
3200 back_max = prog->float_max_offset;
3201 back_min = prog->float_min_offset;
3207 last = HOP3c(strend, /* Cannot start after this */
3208 -(SSize_t)(CHR_SVLEN(must)
3209 - (SvTAIL(must) != 0) + back_min), strbeg);
3211 if (s > reginfo->strbeg)
3212 last1 = HOPc(s, -1);
3214 last1 = s - 1; /* bogus */
3216 /* XXXX check_substr already used to find "s", can optimize if
3217 check_substr==must. */
3219 strend = HOPc(strend, -dontbother);
3220 while ( (s <= last) &&
3221 (s = fbm_instr((unsigned char*)HOP4c(s, back_min, strbeg, strend),
3222 (unsigned char*)strend, must,
3223 multiline ? FBMrf_MULTILINE : 0)) ) {
3224 DEBUG_EXECUTE_r( did_match = 1 );
3225 if (HOPc(s, -back_max) > last1) {
3226 last1 = HOPc(s, -back_min);
3227 s = HOPc(s, -back_max);
3230 char * const t = (last1 >= reginfo->strbeg)
3231 ? HOPc(last1, 1) : last1 + 1;
3233 last1 = HOPc(s, -back_min);
3237 while (s <= last1) {
3238 if (regtry(reginfo, &s))
3241 s++; /* to break out of outer loop */
3248 while (s <= last1) {
3249 if (regtry(reginfo, &s))
3255 DEBUG_EXECUTE_r(if (!did_match) {
3256 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
3257 SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
3258 PerlIO_printf(Perl_debug_log, "Did not find %s substr %s%s...\n",
3259 ((must == prog->anchored_substr || must == prog->anchored_utf8)
3260 ? "anchored" : "floating"),
3261 quoted, RE_SV_TAIL(must));
3265 else if ( (c = progi->regstclass) ) {
3267 const OPCODE op = OP(progi->regstclass);
3268 /* don't bother with what can't match */
3269 if (PL_regkind[op] != EXACT && op != CANY && PL_regkind[op] != TRIE)
3270 strend = HOPc(strend, -(minlen - 1));
3273 SV * const prop = sv_newmortal();
3274 regprop(prog, prop, c, reginfo, NULL);
3276 RE_PV_QUOTED_DECL(quoted,utf8_target,PERL_DEBUG_PAD_ZERO(1),
3278 PerlIO_printf(Perl_debug_log,
3279 "Matching stclass %.*s against %s (%d bytes)\n",
3280 (int)SvCUR(prop), SvPVX_const(prop),
3281 quoted, (int)(strend - s));
3284 if (find_byclass(prog, c, s, strend, reginfo))
3286 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Contradicts stclass... [regexec_flags]\n"));
3290 if (prog->float_substr != NULL || prog->float_utf8 != NULL) {
3298 if (! prog->float_utf8) {
3299 to_utf8_substr(prog);
3301 float_real = prog->float_utf8;
3304 if (! prog->float_substr) {
3305 if (! to_byte_substr(prog)) {
3306 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3309 float_real = prog->float_substr;
3312 little = SvPV_const(float_real, len);
3313 if (SvTAIL(float_real)) {
3314 /* This means that float_real contains an artificial \n on
3315 * the end due to the presence of something like this:
3316 * /foo$/ where we can match both "foo" and "foo\n" at the
3317 * end of the string. So we have to compare the end of the
3318 * string first against the float_real without the \n and
3319 * then against the full float_real with the string. We
3320 * have to watch out for cases where the string might be
3321 * smaller than the float_real or the float_real without
3323 char *checkpos= strend - len;
3325 PerlIO_printf(Perl_debug_log,
3326 "%sChecking for float_real.%s\n",
3327 PL_colors[4], PL_colors[5]));
3328 if (checkpos + 1 < strbeg) {
3329 /* can't match, even if we remove the trailing \n
3330 * string is too short to match */
3332 PerlIO_printf(Perl_debug_log,
3333 "%sString shorter than required trailing substring, cannot match.%s\n",
3334 PL_colors[4], PL_colors[5]));
3336 } else if (memEQ(checkpos + 1, little, len - 1)) {
3337 /* can match, the end of the string matches without the
3339 last = checkpos + 1;
3340 } else if (checkpos < strbeg) {
3341 /* cant match, string is too short when the "\n" is
3344 PerlIO_printf(Perl_debug_log,
3345 "%sString does not contain required trailing substring, cannot match.%s\n",
3346 PL_colors[4], PL_colors[5]));
3348 } else if (!multiline) {
3349 /* non multiline match, so compare with the "\n" at the
3350 * end of the string */
3351 if (memEQ(checkpos, little, len)) {
3355 PerlIO_printf(Perl_debug_log,
3356 "%sString does not contain required trailing substring, cannot match.%s\n",
3357 PL_colors[4], PL_colors[5]));
3361 /* multiline match, so we have to search for a place
3362 * where the full string is located */
3368 last = rninstr(s, strend, little, little + len);
3370 last = strend; /* matching "$" */
3373 /* at one point this block contained a comment which was
3374 * probably incorrect, which said that this was a "should not
3375 * happen" case. Even if it was true when it was written I am
3376 * pretty sure it is not anymore, so I have removed the comment
3377 * and replaced it with this one. Yves */
3379 PerlIO_printf(Perl_debug_log,
3380 "%sString does not contain required substring, cannot match.%s\n",
3381 PL_colors[4], PL_colors[5]
3385 dontbother = strend - last + prog->float_min_offset;
3387 if (minlen && (dontbother < minlen))
3388 dontbother = minlen - 1;
3389 strend -= dontbother; /* this one's always in bytes! */
3390 /* We don't know much -- general case. */
3393 if (regtry(reginfo, &s))
3402 if (regtry(reginfo, &s))
3404 } while (s++ < strend);
3412 /* s/// doesn't like it if $& is earlier than where we asked it to
3413 * start searching (which can happen on something like /.\G/) */
3414 if ( (flags & REXEC_FAIL_ON_UNDERFLOW)
3415 && (prog->offs[0].start < stringarg - strbeg))
3417 /* this should only be possible under \G */
3418 assert(prog->intflags & PREGf_GPOS_SEEN);
3419 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
3420 "matched, but failing for REXEC_FAIL_ON_UNDERFLOW\n"));
3426 PerlIO_printf(Perl_debug_log,
3427 "rex=0x%"UVxf" freeing offs: 0x%"UVxf"\n",
3434 /* clean up; this will trigger destructors that will free all slabs
3435 * above the current one, and cleanup the regmatch_info_aux
3436 * and regmatch_info_aux_eval sructs */
3438 LEAVE_SCOPE(oldsave);
3440 if (RXp_PAREN_NAMES(prog))
3441 (void)hv_iterinit(RXp_PAREN_NAMES(prog));
3443 /* make sure $`, $&, $', and $digit will work later */
3444 if ( !(flags & REXEC_NOT_FIRST) )
3445 S_reg_set_capture_string(aTHX_ rx,
3446 strbeg, reginfo->strend,
3447 sv, flags, utf8_target);
3452 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch failed%s\n",
3453 PL_colors[4], PL_colors[5]));
3455 /* clean up; this will trigger destructors that will free all slabs
3456 * above the current one, and cleanup the regmatch_info_aux
3457 * and regmatch_info_aux_eval sructs */
3459 LEAVE_SCOPE(oldsave);
3462 /* we failed :-( roll it back */
3463 DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
3464 "rex=0x%"UVxf" rolling back offs: freeing=0x%"UVxf" restoring=0x%"UVxf"\n",
3469 Safefree(prog->offs);
3476 /* Set which rex is pointed to by PL_reg_curpm, handling ref counting.
3477 * Do inc before dec, in case old and new rex are the same */
3478 #define SET_reg_curpm(Re2) \
3479 if (reginfo->info_aux_eval) { \
3480 (void)ReREFCNT_inc(Re2); \
3481 ReREFCNT_dec(PM_GETRE(PL_reg_curpm)); \
3482 PM_SETRE((PL_reg_curpm), (Re2)); \
3487 - regtry - try match at specific point
3489 STATIC I32 /* 0 failure, 1 success */
3490 S_regtry(pTHX_ regmatch_info *reginfo, char **startposp)
3493 REGEXP *const rx = reginfo->prog;
3494 regexp *const prog = ReANY(rx);
3496 RXi_GET_DECL(prog,progi);
3497 GET_RE_DEBUG_FLAGS_DECL;
3499 PERL_ARGS_ASSERT_REGTRY;
3501 reginfo->cutpoint=NULL;
3503 prog->offs[0].start = *startposp - reginfo->strbeg;
3504 prog->lastparen = 0;
3505 prog->lastcloseparen = 0;
3507 /* XXXX What this code is doing here?!!! There should be no need
3508 to do this again and again, prog->lastparen should take care of
3511 /* Tests pat.t#187 and split.t#{13,14} seem to depend on this code.
3512 * Actually, the code in regcppop() (which Ilya may be meaning by
3513 * prog->lastparen), is not needed at all by the test suite
3514 * (op/regexp, op/pat, op/split), but that code is needed otherwise
3515 * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
3516 * Meanwhile, this code *is* needed for the
3517 * above-mentioned test suite tests to succeed. The common theme
3518 * on those tests seems to be returning null fields from matches.
3519 * --jhi updated by dapm */
3521 if (prog->nparens) {
3522 regexp_paren_pair *pp = prog->offs;
3524 for (i = prog->nparens; i > (I32)prog->lastparen; i--) {
3532 result = regmatch(reginfo, *startposp, progi->program + 1);
3534 prog->offs[0].end = result;
3537 if (reginfo->cutpoint)
3538 *startposp= reginfo->cutpoint;
3539 REGCP_UNWIND(lastcp);
3544 #define sayYES goto yes
3545 #define sayNO goto no
3546 #define sayNO_SILENT goto no_silent
3548 /* we dont use STMT_START/END here because it leads to
3549 "unreachable code" warnings, which are bogus, but distracting. */
3550 #define CACHEsayNO \
3551 if (ST.cache_mask) \
3552 reginfo->info_aux->poscache[ST.cache_offset] |= ST.cache_mask; \
3555 /* this is used to determine how far from the left messages like
3556 'failed...' are printed. It should be set such that messages
3557 are inline with the regop output that created them.
3559 #define REPORT_CODE_OFF 32
3562 #define CHRTEST_UNINIT -1001 /* c1/c2 haven't been calculated yet */
3563 #define CHRTEST_VOID -1000 /* the c1/c2 "next char" test should be skipped */
3564 #define CHRTEST_NOT_A_CP_1 -999
3565 #define CHRTEST_NOT_A_CP_2 -998
3567 /* grab a new slab and return the first slot in it */
3569 STATIC regmatch_state *
3572 #if PERL_VERSION < 9 && !defined(PERL_CORE)
3575 regmatch_slab *s = PL_regmatch_slab->next;
3577 Newx(s, 1, regmatch_slab);
3578 s->prev = PL_regmatch_slab;
3580 PL_regmatch_slab->next = s;
3582 PL_regmatch_slab = s;
3583 return SLAB_FIRST(s);
3587 /* push a new state then goto it */
3589 #define PUSH_STATE_GOTO(state, node, input) \
3590 pushinput = input; \
3592 st->resume_state = state; \
3595 /* push a new state with success backtracking, then goto it */
3597 #define PUSH_YES_STATE_GOTO(state, node, input) \
3598 pushinput = input; \
3600 st->resume_state = state; \
3601 goto push_yes_state;
3608 regmatch() - main matching routine
3610 This is basically one big switch statement in a loop. We execute an op,
3611 set 'next' to point the next op, and continue. If we come to a point which
3612 we may need to backtrack to on failure such as (A|B|C), we push a
3613 backtrack state onto the backtrack stack. On failure, we pop the top
3614 state, and re-enter the loop at the state indicated. If there are no more
3615 states to pop, we return failure.
3617 Sometimes we also need to backtrack on success; for example /A+/, where
3618 after successfully matching one A, we need to go back and try to
3619 match another one; similarly for lookahead assertions: if the assertion
3620 completes successfully, we backtrack to the state just before the assertion
3621 and then carry on. In these cases, the pushed state is marked as
3622 'backtrack on success too'. This marking is in fact done by a chain of
3623 pointers, each pointing to the previous 'yes' state. On success, we pop to
3624 the nearest yes state, discarding any intermediate failure-only states.
3625 Sometimes a yes state is pushed just to force some cleanup code to be
3626 called at the end of a successful match or submatch; e.g. (??{$re}) uses
3627 it to free the inner regex.
3629 Note that failure backtracking rewinds the cursor position, while
3630 success backtracking leaves it alone.
3632 A pattern is complete when the END op is executed, while a subpattern
3633 such as (?=foo) is complete when the SUCCESS op is executed. Both of these
3634 ops trigger the "pop to last yes state if any, otherwise return true"
3637 A common convention in this function is to use A and B to refer to the two
3638 subpatterns (or to the first nodes thereof) in patterns like /A*B/: so A is
3639 the subpattern to be matched possibly multiple times, while B is the entire
3640 rest of the pattern. Variable and state names reflect this convention.
3642 The states in the main switch are the union of ops and failure/success of
3643 substates associated with with that op. For example, IFMATCH is the op
3644 that does lookahead assertions /(?=A)B/ and so the IFMATCH state means
3645 'execute IFMATCH'; while IFMATCH_A is a state saying that we have just
3646 successfully matched A and IFMATCH_A_fail is a state saying that we have
3647 just failed to match A. Resume states always come in pairs. The backtrack
3648 state we push is marked as 'IFMATCH_A', but when that is popped, we resume
3649 at IFMATCH_A or IFMATCH_A_fail, depending on whether we are backtracking
3650 on success or failure.
3652 The struct that holds a backtracking state is actually a big union, with
3653 one variant for each major type of op. The variable st points to the
3654 top-most backtrack struct. To make the code clearer, within each
3655 block of code we #define ST to alias the relevant union.
3657 Here's a concrete example of a (vastly oversimplified) IFMATCH
3663 #define ST st->u.ifmatch
3665 case IFMATCH: // we are executing the IFMATCH op, (?=A)B
3666 ST.foo = ...; // some state we wish to save
3668 // push a yes backtrack state with a resume value of
3669 // IFMATCH_A/IFMATCH_A_fail, then continue execution at the
3671 PUSH_YES_STATE_GOTO(IFMATCH_A, A, newinput);
3674 case IFMATCH_A: // we have successfully executed A; now continue with B
3676 bar = ST.foo; // do something with the preserved value
3679 case IFMATCH_A_fail: // A failed, so the assertion failed
3680 ...; // do some housekeeping, then ...
3681 sayNO; // propagate the failure
3688 For any old-timers reading this who are familiar with the old recursive
3689 approach, the code above is equivalent to:
3691 case IFMATCH: // we are executing the IFMATCH op, (?=A)B
3700 ...; // do some housekeeping, then ...
3701 sayNO; // propagate the failure
3704 The topmost backtrack state, pointed to by st, is usually free. If you
3705 want to claim it, populate any ST.foo fields in it with values you wish to
3706 save, then do one of
3708 PUSH_STATE_GOTO(resume_state, node, newinput);
3709 PUSH_YES_STATE_GOTO(resume_state, node, newinput);
3711 which sets that backtrack state's resume value to 'resume_state', pushes a
3712 new free entry to the top of the backtrack stack, then goes to 'node'.
3713 On backtracking, the free slot is popped, and the saved state becomes the
3714 new free state. An ST.foo field in this new top state can be temporarily
3715 accessed to retrieve values, but once the main loop is re-entered, it
3716 becomes available for reuse.
3718 Note that the depth of the backtrack stack constantly increases during the
3719 left-to-right execution of the pattern, rather than going up and down with
3720 the pattern nesting. For example the stack is at its maximum at Z at the
3721 end of the pattern, rather than at X in the following:
3723 /(((X)+)+)+....(Y)+....Z/
3725 The only exceptions to this are lookahead/behind assertions and the cut,
3726 (?>A), which pop all the backtrack states associated with A before
3729 Backtrack state structs are allocated in slabs of about 4K in size.
3730 PL_regmatch_state and st always point to the currently active state,
3731 and PL_regmatch_slab points to the slab currently containing
3732 PL_regmatch_state. The first time regmatch() is called, the first slab is
3733 allocated, and is never freed until interpreter destruction. When the slab
3734 is full, a new one is allocated and chained to the end. At exit from
3735 regmatch(), slabs allocated since entry are freed.
3740 #define DEBUG_STATE_pp(pp) \
3742 DUMP_EXEC_POS(locinput, scan, utf8_target); \
3743 PerlIO_printf(Perl_debug_log, \
3744 " %*s"pp" %s%s%s%s%s\n", \
3746 PL_reg_name[st->resume_state], \
3747 ((st==yes_state||st==mark_state) ? "[" : ""), \
3748 ((st==yes_state) ? "Y" : ""), \
3749 ((st==mark_state) ? "M" : ""), \
3750 ((st==yes_state||st==mark_state) ? "]" : "") \
3755 #define REG_NODE_NUM(x) ((x) ? (int)((x)-prog) : -1)
3760 S_debug_start_match(pTHX_ const REGEXP *prog, const bool utf8_target,
3761 const char *start, const char *end, const char *blurb)
3763 const bool utf8_pat = RX_UTF8(prog) ? 1 : 0;
3765 PERL_ARGS_ASSERT_DEBUG_START_MATCH;
3770 RE_PV_QUOTED_DECL(s0, utf8_pat, PERL_DEBUG_PAD_ZERO(0),
3771 RX_PRECOMP_const(prog), RX_PRELEN(prog), 60);
3773 RE_PV_QUOTED_DECL(s1, utf8_target, PERL_DEBUG_PAD_ZERO(1),
3774 start, end - start, 60);
3776 PerlIO_printf(Perl_debug_log,
3777 "%s%s REx%s %s against %s\n",
3778 PL_colors[4], blurb, PL_colors[5], s0, s1);
3780 if (utf8_target||utf8_pat)
3781 PerlIO_printf(Perl_debug_log, "UTF-8 %s%s%s...\n",
3782 utf8_pat ? "pattern" : "",
3783 utf8_pat && utf8_target ? " and " : "",
3784 utf8_target ? "string" : ""
3790 S_dump_exec_pos(pTHX_ const char *locinput,
3791 const regnode *scan,
3792 const char *loc_regeol,
3793 const char *loc_bostr,
3794 const char *loc_reg_starttry,
3795 const bool utf8_target)
3797 const int docolor = *PL_colors[0] || *PL_colors[2] || *PL_colors[4];
3798 const int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */
3799 int l = (loc_regeol - locinput) > taill ? taill : (loc_regeol - locinput);
3800 /* The part of the string before starttry has one color
3801 (pref0_len chars), between starttry and current
3802 position another one (pref_len - pref0_len chars),
3803 after the current position the third one.
3804 We assume that pref0_len <= pref_len, otherwise we
3805 decrease pref0_len. */
3806 int pref_len = (locinput - loc_bostr) > (5 + taill) - l
3807 ? (5 + taill) - l : locinput - loc_bostr;
3810 PERL_ARGS_ASSERT_DUMP_EXEC_POS;
3812 while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput - pref_len)))
3814 pref0_len = pref_len - (locinput - loc_reg_starttry);
3815 if (l + pref_len < (5 + taill) && l < loc_regeol - locinput)
3816 l = ( loc_regeol - locinput > (5 + taill) - pref_len
3817 ? (5 + taill) - pref_len : loc_regeol - locinput);
3818 while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput + l)))
3822 if (pref0_len > pref_len)
3823 pref0_len = pref_len;
3825 const int is_uni = (utf8_target && OP(scan) != CANY) ? 1 : 0;
3827 RE_PV_COLOR_DECL(s0,len0,is_uni,PERL_DEBUG_PAD(0),
3828 (locinput - pref_len),pref0_len, 60, 4, 5);
3830 RE_PV_COLOR_DECL(s1,len1,is_uni,PERL_DEBUG_PAD(1),
3831 (locinput - pref_len + pref0_len),
3832 pref_len - pref0_len, 60, 2, 3);
3834 RE_PV_COLOR_DECL(s2,len2,is_uni,PERL_DEBUG_PAD(2),
3835 locinput, loc_regeol - locinput, 10, 0, 1);
3837 const STRLEN tlen=len0+len1+len2;
3838 PerlIO_printf(Perl_debug_log,
3839 "%4"IVdf" <%.*s%.*s%s%.*s>%*s|",
3840 (IV)(locinput - loc_bostr),
3843 (docolor ? "" : "> <"),
3845 (int)(tlen > 19 ? 0 : 19 - tlen),
3852 /* reg_check_named_buff_matched()
3853 * Checks to see if a named buffer has matched. The data array of
3854 * buffer numbers corresponding to the buffer is expected to reside
3855 * in the regexp->data->data array in the slot stored in the ARG() of
3856 * node involved. Note that this routine doesn't actually care about the
3857 * name, that information is not preserved from compilation to execution.
3858 * Returns the index of the leftmost defined buffer with the given name
3859 * or 0 if non of the buffers matched.
3862 S_reg_check_named_buff_matched(const regexp *rex, const regnode *scan)
3865 RXi_GET_DECL(rex,rexi);
3866 SV *sv_dat= MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
3867 I32 *nums=(I32*)SvPVX(sv_dat);
3869 PERL_ARGS_ASSERT_REG_CHECK_NAMED_BUFF_MATCHED;
3871 for ( n=0; n<SvIVX(sv_dat); n++ ) {
3872 if ((I32)rex->lastparen >= nums[n] &&
3873 rex->offs[nums[n]].end != -1)
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