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
41 * pregcomp and pregexec -- regsub and regerror are not used in perl
43 * Copyright (c) 1986 by University of Toronto.
44 * Written by Henry Spencer. Not derived from licensed software.
46 * Permission is granted to anyone to use this software for any
47 * purpose on any computer system, and to redistribute it freely,
48 * subject to the following restrictions:
50 * 1. The author is not responsible for the consequences of use of
51 * this software, no matter how awful, even if they arise
54 * 2. The origin of this software must not be misrepresented, either
55 * by explicit claim or by omission.
57 * 3. Altered versions must be plainly marked as such, and must not
58 * be misrepresented as being the original software.
60 **** Alterations to Henry's code are...
62 **** Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
63 **** 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
64 **** by Larry Wall and others
66 **** You may distribute under the terms of either the GNU General Public
67 **** License or the Artistic License, as specified in the README file.
69 * Beware that some of this code is subtly aware of the way operator
70 * precedence is structured in regular expressions. Serious changes in
71 * regular-expression syntax might require a total rethink.
74 #define PERL_IN_REGEXEC_C
77 #ifdef PERL_IN_XSUB_RE
83 #include "invlist_inline.h"
84 #include "unicode_constants.h"
86 #define B_ON_NON_UTF8_LOCALE_IS_WRONG \
87 "Use of \\b{} or \\B{} for non-UTF-8 locale is wrong. Assuming a UTF-8 locale"
89 static const char utf8_locale_required[] =
90 "Use of (?[ ]) for non-UTF-8 locale is wrong. Assuming a UTF-8 locale";
93 /* At least one required character in the target string is expressible only in
95 static const char* const non_utf8_target_but_utf8_required
96 = "Can't match, because target string needs to be in UTF-8\n";
99 #define NON_UTF8_TARGET_BUT_UTF8_REQUIRED(target) STMT_START { \
100 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s", non_utf8_target_but_utf8_required));\
104 #define HAS_NONLATIN1_FOLD_CLOSURE(i) _HAS_NONLATIN1_FOLD_CLOSURE_ONLY_FOR_USE_BY_REGCOMP_DOT_C_AND_REGEXEC_DOT_C(i)
107 #define STATIC static
110 /* Valid only for non-utf8 strings: avoids the reginclass
111 * call if there are no complications: i.e., if everything matchable is
112 * straight forward in the bitmap */
113 #define REGINCLASS(prog,p,c) (ANYOF_FLAGS(p) ? reginclass(prog,p,c,c+1,0) \
114 : ANYOF_BITMAP_TEST(p,*(c)))
120 #define CHR_SVLEN(sv) (utf8_target ? sv_len_utf8(sv) : SvCUR(sv))
121 #define CHR_DIST(a,b) (reginfo->is_utf8_target ? utf8_distance(a,b) : a - b)
123 #define HOPc(pos,off) \
124 (char *)(reginfo->is_utf8_target \
125 ? reghop3((U8*)pos, off, \
126 (U8*)(off >= 0 ? reginfo->strend : reginfo->strbeg)) \
129 #define HOPBACKc(pos, off) \
130 (char*)(reginfo->is_utf8_target \
131 ? reghopmaybe3((U8*)pos, -off, (U8*)(reginfo->strbeg)) \
132 : (pos - off >= reginfo->strbeg) \
136 #define HOP3(pos,off,lim) (reginfo->is_utf8_target ? reghop3((U8*)(pos), off, (U8*)(lim)) : (U8*)(pos + off))
137 #define HOP3c(pos,off,lim) ((char*)HOP3(pos,off,lim))
139 /* lim must be +ve. Returns NULL on overshoot */
140 #define HOPMAYBE3(pos,off,lim) \
141 (reginfo->is_utf8_target \
142 ? reghopmaybe3((U8*)pos, off, (U8*)(lim)) \
143 : ((U8*)pos + off <= lim) \
147 /* like HOP3, but limits the result to <= lim even for the non-utf8 case.
148 * off must be >=0; args should be vars rather than expressions */
149 #define HOP3lim(pos,off,lim) (reginfo->is_utf8_target \
150 ? reghop3((U8*)(pos), off, (U8*)(lim)) \
151 : (U8*)((pos + off) > lim ? lim : (pos + off)))
153 #define HOP4(pos,off,llim, rlim) (reginfo->is_utf8_target \
154 ? reghop4((U8*)(pos), off, (U8*)(llim), (U8*)(rlim)) \
156 #define HOP4c(pos,off,llim, rlim) ((char*)HOP4(pos,off,llim, rlim))
158 #define NEXTCHR_EOS -10 /* nextchr has fallen off the end */
159 #define NEXTCHR_IS_EOS (nextchr < 0)
161 #define SET_nextchr \
162 nextchr = ((locinput < reginfo->strend) ? UCHARAT(locinput) : NEXTCHR_EOS)
164 #define SET_locinput(p) \
169 #define LOAD_UTF8_CHARCLASS(swash_ptr, property_name, invlist) STMT_START { \
171 U8 flags = _CORE_SWASH_INIT_ACCEPT_INVLIST; \
172 swash_ptr = _core_swash_init("utf8", property_name, &PL_sv_undef, \
173 1, 0, invlist, &flags); \
178 /* If in debug mode, we test that a known character properly matches */
180 # define LOAD_UTF8_CHARCLASS_DEBUG_TEST(swash_ptr, \
183 utf8_char_in_property) \
184 LOAD_UTF8_CHARCLASS(swash_ptr, property_name, invlist); \
185 assert(swash_fetch(swash_ptr, (U8 *) utf8_char_in_property, TRUE));
187 # define LOAD_UTF8_CHARCLASS_DEBUG_TEST(swash_ptr, \
190 utf8_char_in_property) \
191 LOAD_UTF8_CHARCLASS(swash_ptr, property_name, invlist)
194 #define LOAD_UTF8_CHARCLASS_ALNUM() LOAD_UTF8_CHARCLASS_DEBUG_TEST( \
195 PL_utf8_swash_ptrs[_CC_WORDCHAR], \
197 PL_XPosix_ptrs[_CC_WORDCHAR], \
198 LATIN_SMALL_LIGATURE_LONG_S_T_UTF8);
200 #define PLACEHOLDER /* Something for the preprocessor to grab onto */
201 /* TODO: Combine JUMPABLE and HAS_TEXT to cache OP(rn) */
203 /* for use after a quantifier and before an EXACT-like node -- japhy */
204 /* it would be nice to rework regcomp.sym to generate this stuff. sigh
206 * NOTE that *nothing* that affects backtracking should be in here, specifically
207 * VERBS must NOT be included. JUMPABLE is used to determine if we can ignore a
208 * node that is in between two EXACT like nodes when ascertaining what the required
209 * "follow" character is. This should probably be moved to regex compile time
210 * although it may be done at run time beause of the REF possibility - more
211 * investigation required. -- demerphq
213 #define JUMPABLE(rn) ( \
215 (OP(rn) == CLOSE && (!cur_eval || cur_eval->u.eval.close_paren != ARG(rn))) || \
217 OP(rn) == SUSPEND || OP(rn) == IFMATCH || \
218 OP(rn) == PLUS || OP(rn) == MINMOD || \
220 (PL_regkind[OP(rn)] == CURLY && ARG1(rn) > 0) \
222 #define IS_EXACT(rn) (PL_regkind[OP(rn)] == EXACT)
224 #define HAS_TEXT(rn) ( IS_EXACT(rn) || PL_regkind[OP(rn)] == REF )
227 /* Currently these are only used when PL_regkind[OP(rn)] == EXACT so
228 we don't need this definition. XXX These are now out-of-sync*/
229 #define IS_TEXT(rn) ( OP(rn)==EXACT || OP(rn)==REF || OP(rn)==NREF )
230 #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 )
231 #define IS_TEXTFL(rn) ( OP(rn)==EXACTFL || OP(rn)==REFFL || OP(rn)==NREFFL )
234 /* ... so we use this as its faster. */
235 #define IS_TEXT(rn) ( OP(rn)==EXACT || OP(rn)==EXACTL )
236 #define IS_TEXTFU(rn) ( OP(rn)==EXACTFU || OP(rn)==EXACTFLU8 || OP(rn)==EXACTFU_SS || OP(rn) == EXACTFA || OP(rn) == EXACTFA_NO_TRIE)
237 #define IS_TEXTF(rn) ( OP(rn)==EXACTF )
238 #define IS_TEXTFL(rn) ( OP(rn)==EXACTFL )
243 Search for mandatory following text node; for lookahead, the text must
244 follow but for lookbehind (rn->flags != 0) we skip to the next step.
246 #define FIND_NEXT_IMPT(rn) STMT_START { \
247 while (JUMPABLE(rn)) { \
248 const OPCODE type = OP(rn); \
249 if (type == SUSPEND || PL_regkind[type] == CURLY) \
250 rn = NEXTOPER(NEXTOPER(rn)); \
251 else if (type == PLUS) \
253 else if (type == IFMATCH) \
254 rn = (rn->flags == 0) ? NEXTOPER(NEXTOPER(rn)) : rn + ARG(rn); \
255 else rn += NEXT_OFF(rn); \
259 #define SLAB_FIRST(s) (&(s)->states[0])
260 #define SLAB_LAST(s) (&(s)->states[PERL_REGMATCH_SLAB_SLOTS-1])
262 static void S_setup_eval_state(pTHX_ regmatch_info *const reginfo);
263 static void S_cleanup_regmatch_info_aux(pTHX_ void *arg);
264 static regmatch_state * S_push_slab(pTHX);
266 #define REGCP_PAREN_ELEMS 3
267 #define REGCP_OTHER_ELEMS 3
268 #define REGCP_FRAME_ELEMS 1
269 /* REGCP_FRAME_ELEMS are not part of the REGCP_OTHER_ELEMS and
270 * are needed for the regexp context stack bookkeeping. */
273 S_regcppush(pTHX_ const regexp *rex, I32 parenfloor, U32 maxopenparen)
275 const int retval = PL_savestack_ix;
276 const int paren_elems_to_push =
277 (maxopenparen - parenfloor) * REGCP_PAREN_ELEMS;
278 const UV total_elems = paren_elems_to_push + REGCP_OTHER_ELEMS;
279 const UV elems_shifted = total_elems << SAVE_TIGHT_SHIFT;
281 GET_RE_DEBUG_FLAGS_DECL;
283 PERL_ARGS_ASSERT_REGCPPUSH;
285 if (paren_elems_to_push < 0)
286 Perl_croak(aTHX_ "panic: paren_elems_to_push, %i < 0, maxopenparen: %i parenfloor: %i REGCP_PAREN_ELEMS: %u",
287 (int)paren_elems_to_push, (int)maxopenparen,
288 (int)parenfloor, (unsigned)REGCP_PAREN_ELEMS);
290 if ((elems_shifted >> SAVE_TIGHT_SHIFT) != total_elems)
291 Perl_croak(aTHX_ "panic: paren_elems_to_push offset %"UVuf
292 " out of range (%lu-%ld)",
294 (unsigned long)maxopenparen,
297 SSGROW(total_elems + REGCP_FRAME_ELEMS);
300 if ((int)maxopenparen > (int)parenfloor)
301 PerlIO_printf(Perl_debug_log,
302 "rex=0x%"UVxf" offs=0x%"UVxf": saving capture indices:\n",
307 for (p = parenfloor+1; p <= (I32)maxopenparen; p++) {
308 /* REGCP_PARENS_ELEMS are pushed per pairs of parentheses. */
309 SSPUSHIV(rex->offs[p].end);
310 SSPUSHIV(rex->offs[p].start);
311 SSPUSHINT(rex->offs[p].start_tmp);
312 DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
313 " \\%"UVuf": %"IVdf"(%"IVdf")..%"IVdf"\n",
315 (IV)rex->offs[p].start,
316 (IV)rex->offs[p].start_tmp,
320 /* REGCP_OTHER_ELEMS are pushed in any case, parentheses or no. */
321 SSPUSHINT(maxopenparen);
322 SSPUSHINT(rex->lastparen);
323 SSPUSHINT(rex->lastcloseparen);
324 SSPUSHUV(SAVEt_REGCONTEXT | elems_shifted); /* Magic cookie. */
329 /* These are needed since we do not localize EVAL nodes: */
330 #define REGCP_SET(cp) \
332 PerlIO_printf(Perl_debug_log, \
333 " Setting an EVAL scope, savestack=%"IVdf"\n", \
334 (IV)PL_savestack_ix)); \
337 #define REGCP_UNWIND(cp) \
339 if (cp != PL_savestack_ix) \
340 PerlIO_printf(Perl_debug_log, \
341 " Clearing an EVAL scope, savestack=%"IVdf"..%"IVdf"\n", \
342 (IV)(cp), (IV)PL_savestack_ix)); \
345 #define UNWIND_PAREN(lp, lcp) \
346 for (n = rex->lastparen; n > lp; n--) \
347 rex->offs[n].end = -1; \
348 rex->lastparen = n; \
349 rex->lastcloseparen = lcp;
353 S_regcppop(pTHX_ regexp *rex, U32 *maxopenparen_p)
357 GET_RE_DEBUG_FLAGS_DECL;
359 PERL_ARGS_ASSERT_REGCPPOP;
361 /* Pop REGCP_OTHER_ELEMS before the parentheses loop starts. */
363 assert((i & SAVE_MASK) == SAVEt_REGCONTEXT); /* Check that the magic cookie is there. */
364 i >>= SAVE_TIGHT_SHIFT; /* Parentheses elements to pop. */
365 rex->lastcloseparen = SSPOPINT;
366 rex->lastparen = SSPOPINT;
367 *maxopenparen_p = SSPOPINT;
369 i -= REGCP_OTHER_ELEMS;
370 /* Now restore the parentheses context. */
372 if (i || rex->lastparen + 1 <= rex->nparens)
373 PerlIO_printf(Perl_debug_log,
374 "rex=0x%"UVxf" offs=0x%"UVxf": restoring capture indices to:\n",
379 paren = *maxopenparen_p;
380 for ( ; i > 0; i -= REGCP_PAREN_ELEMS) {
382 rex->offs[paren].start_tmp = SSPOPINT;
383 rex->offs[paren].start = SSPOPIV;
385 if (paren <= rex->lastparen)
386 rex->offs[paren].end = tmps;
387 DEBUG_BUFFERS_r( PerlIO_printf(Perl_debug_log,
388 " \\%"UVuf": %"IVdf"(%"IVdf")..%"IVdf"%s\n",
390 (IV)rex->offs[paren].start,
391 (IV)rex->offs[paren].start_tmp,
392 (IV)rex->offs[paren].end,
393 (paren > rex->lastparen ? "(skipped)" : ""));
398 /* It would seem that the similar code in regtry()
399 * already takes care of this, and in fact it is in
400 * a better location to since this code can #if 0-ed out
401 * but the code in regtry() is needed or otherwise tests
402 * requiring null fields (pat.t#187 and split.t#{13,14}
403 * (as of patchlevel 7877) will fail. Then again,
404 * this code seems to be necessary or otherwise
405 * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
406 * --jhi updated by dapm */
407 for (i = rex->lastparen + 1; i <= rex->nparens; i++) {
408 if (i > *maxopenparen_p)
409 rex->offs[i].start = -1;
410 rex->offs[i].end = -1;
411 DEBUG_BUFFERS_r( PerlIO_printf(Perl_debug_log,
412 " \\%"UVuf": %s ..-1 undeffing\n",
414 (i > *maxopenparen_p) ? "-1" : " "
420 /* restore the parens and associated vars at savestack position ix,
421 * but without popping the stack */
424 S_regcp_restore(pTHX_ regexp *rex, I32 ix, U32 *maxopenparen_p)
426 I32 tmpix = PL_savestack_ix;
427 PL_savestack_ix = ix;
428 regcppop(rex, maxopenparen_p);
429 PL_savestack_ix = tmpix;
432 #define regcpblow(cp) LEAVE_SCOPE(cp) /* Ignores regcppush()ed data. */
435 S_isFOO_lc(pTHX_ const U8 classnum, const U8 character)
437 /* Returns a boolean as to whether or not 'character' is a member of the
438 * Posix character class given by 'classnum' that should be equivalent to a
439 * value in the typedef '_char_class_number'.
441 * Ideally this could be replaced by a just an array of function pointers
442 * to the C library functions that implement the macros this calls.
443 * However, to compile, the precise function signatures are required, and
444 * these may vary from platform to to platform. To avoid having to figure
445 * out what those all are on each platform, I (khw) am using this method,
446 * which adds an extra layer of function call overhead (unless the C
447 * optimizer strips it away). But we don't particularly care about
448 * performance with locales anyway. */
450 switch ((_char_class_number) classnum) {
451 case _CC_ENUM_ALPHANUMERIC: return isALPHANUMERIC_LC(character);
452 case _CC_ENUM_ALPHA: return isALPHA_LC(character);
453 case _CC_ENUM_ASCII: return isASCII_LC(character);
454 case _CC_ENUM_BLANK: return isBLANK_LC(character);
455 case _CC_ENUM_CASED: return isLOWER_LC(character)
456 || isUPPER_LC(character);
457 case _CC_ENUM_CNTRL: return isCNTRL_LC(character);
458 case _CC_ENUM_DIGIT: return isDIGIT_LC(character);
459 case _CC_ENUM_GRAPH: return isGRAPH_LC(character);
460 case _CC_ENUM_LOWER: return isLOWER_LC(character);
461 case _CC_ENUM_PRINT: return isPRINT_LC(character);
462 case _CC_ENUM_PUNCT: return isPUNCT_LC(character);
463 case _CC_ENUM_SPACE: return isSPACE_LC(character);
464 case _CC_ENUM_UPPER: return isUPPER_LC(character);
465 case _CC_ENUM_WORDCHAR: return isWORDCHAR_LC(character);
466 case _CC_ENUM_XDIGIT: return isXDIGIT_LC(character);
467 default: /* VERTSPACE should never occur in locales */
468 Perl_croak(aTHX_ "panic: isFOO_lc() has an unexpected character class '%d'", classnum);
471 NOT_REACHED; /* NOTREACHED */
476 S_isFOO_utf8_lc(pTHX_ const U8 classnum, const U8* character)
478 /* Returns a boolean as to whether or not the (well-formed) UTF-8-encoded
479 * 'character' is a member of the Posix character class given by 'classnum'
480 * that should be equivalent to a value in the typedef
481 * '_char_class_number'.
483 * This just calls isFOO_lc on the code point for the character if it is in
484 * the range 0-255. Outside that range, all characters use Unicode
485 * rules, ignoring any locale. So use the Unicode function if this class
486 * requires a swash, and use the Unicode macro otherwise. */
488 PERL_ARGS_ASSERT_ISFOO_UTF8_LC;
490 if (UTF8_IS_INVARIANT(*character)) {
491 return isFOO_lc(classnum, *character);
493 else if (UTF8_IS_DOWNGRADEABLE_START(*character)) {
494 return isFOO_lc(classnum,
495 EIGHT_BIT_UTF8_TO_NATIVE(*character, *(character + 1)));
498 _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(character, character + UTF8SKIP(character));
500 if (classnum < _FIRST_NON_SWASH_CC) {
502 /* Initialize the swash unless done already */
503 if (! PL_utf8_swash_ptrs[classnum]) {
504 U8 flags = _CORE_SWASH_INIT_ACCEPT_INVLIST;
505 PL_utf8_swash_ptrs[classnum] =
506 _core_swash_init("utf8",
509 PL_XPosix_ptrs[classnum], &flags);
512 return cBOOL(swash_fetch(PL_utf8_swash_ptrs[classnum], (U8 *)
514 TRUE /* is UTF */ ));
517 switch ((_char_class_number) classnum) {
518 case _CC_ENUM_SPACE: return is_XPERLSPACE_high(character);
519 case _CC_ENUM_BLANK: return is_HORIZWS_high(character);
520 case _CC_ENUM_XDIGIT: return is_XDIGIT_high(character);
521 case _CC_ENUM_VERTSPACE: return is_VERTWS_high(character);
525 return FALSE; /* Things like CNTRL are always below 256 */
529 * pregexec and friends
532 #ifndef PERL_IN_XSUB_RE
534 - pregexec - match a regexp against a string
537 Perl_pregexec(pTHX_ REGEXP * const prog, char* stringarg, char *strend,
538 char *strbeg, SSize_t minend, SV *screamer, U32 nosave)
539 /* stringarg: the point in the string at which to begin matching */
540 /* strend: pointer to null at end of string */
541 /* strbeg: real beginning of string */
542 /* minend: end of match must be >= minend bytes after stringarg. */
543 /* screamer: SV being matched: only used for utf8 flag, pos() etc; string
544 * itself is accessed via the pointers above */
545 /* nosave: For optimizations. */
547 PERL_ARGS_ASSERT_PREGEXEC;
550 regexec_flags(prog, stringarg, strend, strbeg, minend, screamer, NULL,
551 nosave ? 0 : REXEC_COPY_STR);
557 /* re_intuit_start():
559 * Based on some optimiser hints, try to find the earliest position in the
560 * string where the regex could match.
562 * rx: the regex to match against
563 * sv: the SV being matched: only used for utf8 flag; the string
564 * itself is accessed via the pointers below. Note that on
565 * something like an overloaded SV, SvPOK(sv) may be false
566 * and the string pointers may point to something unrelated to
568 * strbeg: real beginning of string
569 * strpos: the point in the string at which to begin matching
570 * strend: pointer to the byte following the last char of the string
571 * flags currently unused; set to 0
572 * data: currently unused; set to NULL
574 * The basic idea of re_intuit_start() is to use some known information
575 * about the pattern, namely:
577 * a) the longest known anchored substring (i.e. one that's at a
578 * constant offset from the beginning of the pattern; but not
579 * necessarily at a fixed offset from the beginning of the
581 * b) the longest floating substring (i.e. one that's not at a constant
582 * offset from the beginning of the pattern);
583 * c) Whether the pattern is anchored to the string; either
584 * an absolute anchor: /^../, or anchored to \n: /^.../m,
585 * or anchored to pos(): /\G/;
586 * d) A start class: a real or synthetic character class which
587 * represents which characters are legal at the start of the pattern;
589 * to either quickly reject the match, or to find the earliest position
590 * within the string at which the pattern might match, thus avoiding
591 * running the full NFA engine at those earlier locations, only to
592 * eventually fail and retry further along.
594 * Returns NULL if the pattern can't match, or returns the address within
595 * the string which is the earliest place the match could occur.
597 * The longest of the anchored and floating substrings is called 'check'
598 * and is checked first. The other is called 'other' and is checked
599 * second. The 'other' substring may not be present. For example,
601 * /(abc|xyz)ABC\d{0,3}DEFG/
605 * check substr (float) = "DEFG", offset 6..9 chars
606 * other substr (anchored) = "ABC", offset 3..3 chars
609 * Be aware that during the course of this function, sometimes 'anchored'
610 * refers to a substring being anchored relative to the start of the
611 * pattern, and sometimes to the pattern itself being anchored relative to
612 * the string. For example:
614 * /\dabc/: "abc" is anchored to the pattern;
615 * /^\dabc/: "abc" is anchored to the pattern and the string;
616 * /\d+abc/: "abc" is anchored to neither the pattern nor the string;
617 * /^\d+abc/: "abc" is anchored to neither the pattern nor the string,
618 * but the pattern is anchored to the string.
622 Perl_re_intuit_start(pTHX_
625 const char * const strbeg,
629 re_scream_pos_data *data)
631 struct regexp *const prog = ReANY(rx);
632 SSize_t start_shift = prog->check_offset_min;
633 /* Should be nonnegative! */
634 SSize_t end_shift = 0;
635 /* current lowest pos in string where the regex can start matching */
636 char *rx_origin = strpos;
638 const bool utf8_target = (sv && SvUTF8(sv)) ? 1 : 0; /* if no sv we have to assume bytes */
639 U8 other_ix = 1 - prog->substrs->check_ix;
641 char *other_last = strpos;/* latest pos 'other' substr already checked to */
642 char *check_at = NULL; /* check substr found at this pos */
643 const I32 multiline = prog->extflags & RXf_PMf_MULTILINE;
644 RXi_GET_DECL(prog,progi);
645 regmatch_info reginfo_buf; /* create some info to pass to find_byclass */
646 regmatch_info *const reginfo = ®info_buf;
647 GET_RE_DEBUG_FLAGS_DECL;
649 PERL_ARGS_ASSERT_RE_INTUIT_START;
650 PERL_UNUSED_ARG(flags);
651 PERL_UNUSED_ARG(data);
653 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
654 "Intuit: trying to determine minimum start position...\n"));
656 /* for now, assume that all substr offsets are positive. If at some point
657 * in the future someone wants to do clever things with look-behind and
658 * -ve offsets, they'll need to fix up any code in this function
659 * which uses these offsets. See the thread beginning
660 * <20140113145929.GF27210@iabyn.com>
662 assert(prog->substrs->data[0].min_offset >= 0);
663 assert(prog->substrs->data[0].max_offset >= 0);
664 assert(prog->substrs->data[1].min_offset >= 0);
665 assert(prog->substrs->data[1].max_offset >= 0);
666 assert(prog->substrs->data[2].min_offset >= 0);
667 assert(prog->substrs->data[2].max_offset >= 0);
669 /* for now, assume that if both present, that the floating substring
670 * doesn't start before the anchored substring.
671 * If you break this assumption (e.g. doing better optimisations
672 * with lookahead/behind), then you'll need to audit the code in this
673 * function carefully first
676 ! ( (prog->anchored_utf8 || prog->anchored_substr)
677 && (prog->float_utf8 || prog->float_substr))
678 || (prog->float_min_offset >= prog->anchored_offset));
680 /* byte rather than char calculation for efficiency. It fails
681 * to quickly reject some cases that can't match, but will reject
682 * them later after doing full char arithmetic */
683 if (prog->minlen > strend - strpos) {
684 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
685 " String too short...\n"));
689 RX_MATCH_UTF8_set(rx,utf8_target);
690 reginfo->is_utf8_target = cBOOL(utf8_target);
691 reginfo->info_aux = NULL;
692 reginfo->strbeg = strbeg;
693 reginfo->strend = strend;
694 reginfo->is_utf8_pat = cBOOL(RX_UTF8(rx));
696 /* not actually used within intuit, but zero for safety anyway */
697 reginfo->poscache_maxiter = 0;
700 if (!prog->check_utf8 && prog->check_substr)
701 to_utf8_substr(prog);
702 check = prog->check_utf8;
704 if (!prog->check_substr && prog->check_utf8) {
705 if (! to_byte_substr(prog)) {
706 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(fail);
709 check = prog->check_substr;
712 /* dump the various substring data */
713 DEBUG_OPTIMISE_MORE_r({
715 for (i=0; i<=2; i++) {
716 SV *sv = (utf8_target ? prog->substrs->data[i].utf8_substr
717 : prog->substrs->data[i].substr);
721 PerlIO_printf(Perl_debug_log,
722 " substrs[%d]: min=%"IVdf" max=%"IVdf" end shift=%"IVdf
723 " useful=%"IVdf" utf8=%d [%s]\n",
725 (IV)prog->substrs->data[i].min_offset,
726 (IV)prog->substrs->data[i].max_offset,
727 (IV)prog->substrs->data[i].end_shift,
734 if (prog->intflags & PREGf_ANCH) { /* Match at \G, beg-of-str or after \n */
736 /* ml_anch: check after \n?
738 * A note about PREGf_IMPLICIT: on an un-anchored pattern beginning
739 * with /.*.../, these flags will have been added by the
741 * /.*abc/, /.*abc/m: PREGf_IMPLICIT | PREGf_ANCH_MBOL
742 * /.*abc/s: PREGf_IMPLICIT | PREGf_ANCH_SBOL
744 ml_anch = (prog->intflags & PREGf_ANCH_MBOL)
745 && !(prog->intflags & PREGf_IMPLICIT);
747 if (!ml_anch && !(prog->intflags & PREGf_IMPLICIT)) {
748 /* we are only allowed to match at BOS or \G */
750 /* trivially reject if there's a BOS anchor and we're not at BOS.
752 * Note that we don't try to do a similar quick reject for
753 * \G, since generally the caller will have calculated strpos
754 * based on pos() and gofs, so the string is already correctly
755 * anchored by definition; and handling the exceptions would
756 * be too fiddly (e.g. REXEC_IGNOREPOS).
758 if ( strpos != strbeg
759 && (prog->intflags & PREGf_ANCH_SBOL))
761 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
762 " Not at start...\n"));
766 /* in the presence of an anchor, the anchored (relative to the
767 * start of the regex) substr must also be anchored relative
768 * to strpos. So quickly reject if substr isn't found there.
769 * This works for \G too, because the caller will already have
770 * subtracted gofs from pos, and gofs is the offset from the
771 * \G to the start of the regex. For example, in /.abc\Gdef/,
772 * where substr="abcdef", pos()=3, gofs=4, offset_min=1:
773 * caller will have set strpos=pos()-4; we look for the substr
774 * at position pos()-4+1, which lines up with the "a" */
776 if (prog->check_offset_min == prog->check_offset_max) {
777 /* Substring at constant offset from beg-of-str... */
778 SSize_t slen = SvCUR(check);
779 char *s = HOP3c(strpos, prog->check_offset_min, strend);
781 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
782 " Looking for check substr at fixed offset %"IVdf"...\n",
783 (IV)prog->check_offset_min));
786 /* In this case, the regex is anchored at the end too.
787 * Unless it's a multiline match, the lengths must match
788 * exactly, give or take a \n. NB: slen >= 1 since
789 * the last char of check is \n */
791 && ( strend - s > slen
792 || strend - s < slen - 1
793 || (strend - s == slen && strend[-1] != '\n')))
795 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
796 " String too long...\n"));
799 /* Now should match s[0..slen-2] */
802 if (slen && (*SvPVX_const(check) != *s
803 || (slen > 1 && memNE(SvPVX_const(check), s, slen))))
805 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
806 " String not equal...\n"));
811 goto success_at_start;
816 end_shift = prog->check_end_shift;
818 #ifdef DEBUGGING /* 7/99: reports of failure (with the older version) */
820 Perl_croak(aTHX_ "panic: end_shift: %"IVdf" pattern:\n%s\n ",
821 (IV)end_shift, RX_PRECOMP(prog));
826 /* This is the (re)entry point of the main loop in this function.
827 * The goal of this loop is to:
828 * 1) find the "check" substring in the region rx_origin..strend
829 * (adjusted by start_shift / end_shift). If not found, reject
831 * 2) If it exists, look for the "other" substr too if defined; for
832 * example, if the check substr maps to the anchored substr, then
833 * check the floating substr, and vice-versa. If not found, go
834 * back to (1) with rx_origin suitably incremented.
835 * 3) If we find an rx_origin position that doesn't contradict
836 * either of the substrings, then check the possible additional
837 * constraints on rx_origin of /^.../m or a known start class.
838 * If these fail, then depending on which constraints fail, jump
839 * back to here, or to various other re-entry points further along
840 * that skip some of the first steps.
841 * 4) If we pass all those tests, update the BmUSEFUL() count on the
842 * substring. If the start position was determined to be at the
843 * beginning of the string - so, not rejected, but not optimised,
844 * since we have to run regmatch from position 0 - decrement the
845 * BmUSEFUL() count. Otherwise increment it.
849 /* first, look for the 'check' substring */
855 DEBUG_OPTIMISE_MORE_r({
856 PerlIO_printf(Perl_debug_log,
857 " At restart: rx_origin=%"IVdf" Check offset min: %"IVdf
858 " Start shift: %"IVdf" End shift %"IVdf
859 " Real end Shift: %"IVdf"\n",
860 (IV)(rx_origin - strbeg),
861 (IV)prog->check_offset_min,
864 (IV)prog->check_end_shift);
867 end_point = HOP3(strend, -end_shift, strbeg);
868 start_point = HOPMAYBE3(rx_origin, start_shift, end_point);
873 /* If the regex is absolutely anchored to either the start of the
874 * string (SBOL) or to pos() (ANCH_GPOS), then
875 * check_offset_max represents an upper bound on the string where
876 * the substr could start. For the ANCH_GPOS case, we assume that
877 * the caller of intuit will have already set strpos to
878 * pos()-gofs, so in this case strpos + offset_max will still be
879 * an upper bound on the substr.
882 && prog->intflags & PREGf_ANCH
883 && prog->check_offset_max != SSize_t_MAX)
885 SSize_t len = SvCUR(check) - !!SvTAIL(check);
886 const char * const anchor =
887 (prog->intflags & PREGf_ANCH_GPOS ? strpos : strbeg);
889 /* do a bytes rather than chars comparison. It's conservative;
890 * so it skips doing the HOP if the result can't possibly end
891 * up earlier than the old value of end_point.
893 if ((char*)end_point - anchor > prog->check_offset_max) {
894 end_point = HOP3lim((U8*)anchor,
895 prog->check_offset_max,
901 check_at = fbm_instr( start_point, end_point,
902 check, multiline ? FBMrf_MULTILINE : 0);
904 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
905 " doing 'check' fbm scan, [%"IVdf"..%"IVdf"] gave %"IVdf"\n",
906 (IV)((char*)start_point - strbeg),
907 (IV)((char*)end_point - strbeg),
908 (IV)(check_at ? check_at - strbeg : -1)
911 /* Update the count-of-usability, remove useless subpatterns,
915 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
916 SvPVX_const(check), RE_SV_DUMPLEN(check), 30);
917 PerlIO_printf(Perl_debug_log, " %s %s substr %s%s%s",
918 (check_at ? "Found" : "Did not find"),
919 (check == (utf8_target ? prog->anchored_utf8 : prog->anchored_substr)
920 ? "anchored" : "floating"),
923 (check_at ? " at offset " : "...\n") );
928 /* set rx_origin to the minimum position where the regex could start
929 * matching, given the constraint of the just-matched check substring.
930 * But don't set it lower than previously.
933 if (check_at - rx_origin > prog->check_offset_max)
934 rx_origin = HOP3c(check_at, -prog->check_offset_max, rx_origin);
935 /* Finish the diagnostic message */
936 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
937 "%ld (rx_origin now %"IVdf")...\n",
938 (long)(check_at - strbeg),
939 (IV)(rx_origin - strbeg)
944 /* now look for the 'other' substring if defined */
946 if (utf8_target ? prog->substrs->data[other_ix].utf8_substr
947 : prog->substrs->data[other_ix].substr)
949 /* Take into account the "other" substring. */
953 struct reg_substr_datum *other;
956 other = &prog->substrs->data[other_ix];
958 /* if "other" is anchored:
959 * we've previously found a floating substr starting at check_at.
960 * This means that the regex origin must lie somewhere
961 * between min (rx_origin): HOP3(check_at, -check_offset_max)
962 * and max: HOP3(check_at, -check_offset_min)
963 * (except that min will be >= strpos)
964 * So the fixed substr must lie somewhere between
965 * HOP3(min, anchored_offset)
966 * HOP3(max, anchored_offset) + SvCUR(substr)
969 /* if "other" is floating
970 * Calculate last1, the absolute latest point where the
971 * floating substr could start in the string, ignoring any
972 * constraints from the earlier fixed match. It is calculated
975 * strend - prog->minlen (in chars) is the absolute latest
976 * position within the string where the origin of the regex
977 * could appear. The latest start point for the floating
978 * substr is float_min_offset(*) on from the start of the
979 * regex. last1 simply combines thee two offsets.
981 * (*) You might think the latest start point should be
982 * float_max_offset from the regex origin, and technically
983 * you'd be correct. However, consider
985 * Here, float min, max are 3,5 and minlen is 7.
986 * This can match either
990 * In the first case, the regex matches minlen chars; in the
991 * second, minlen+1, in the third, minlen+2.
992 * In the first case, the floating offset is 3 (which equals
993 * float_min), in the second, 4, and in the third, 5 (which
994 * equals float_max). In all cases, the floating string bcd
995 * can never start more than 4 chars from the end of the
996 * string, which equals minlen - float_min. As the substring
997 * starts to match more than float_min from the start of the
998 * regex, it makes the regex match more than minlen chars,
999 * and the two cancel each other out. So we can always use
1000 * float_min - minlen, rather than float_max - minlen for the
1001 * latest position in the string.
1003 * Note that -minlen + float_min_offset is equivalent (AFAIKT)
1004 * to CHR_SVLEN(must) - !!SvTAIL(must) + prog->float_end_shift
1007 assert(prog->minlen >= other->min_offset);
1008 last1 = HOP3c(strend,
1009 other->min_offset - prog->minlen, strbeg);
1011 if (other_ix) {/* i.e. if (other-is-float) */
1012 /* last is the latest point where the floating substr could
1013 * start, *given* any constraints from the earlier fixed
1014 * match. This constraint is that the floating string starts
1015 * <= float_max_offset chars from the regex origin (rx_origin).
1016 * If this value is less than last1, use it instead.
1018 assert(rx_origin <= last1);
1020 /* this condition handles the offset==infinity case, and
1021 * is a short-cut otherwise. Although it's comparing a
1022 * byte offset to a char length, it does so in a safe way,
1023 * since 1 char always occupies 1 or more bytes,
1024 * so if a string range is (last1 - rx_origin) bytes,
1025 * it will be less than or equal to (last1 - rx_origin)
1026 * chars; meaning it errs towards doing the accurate HOP3
1027 * rather than just using last1 as a short-cut */
1028 (last1 - rx_origin) < other->max_offset
1030 : (char*)HOP3lim(rx_origin, other->max_offset, last1);
1033 assert(strpos + start_shift <= check_at);
1034 last = HOP4c(check_at, other->min_offset - start_shift,
1038 s = HOP3c(rx_origin, other->min_offset, strend);
1039 if (s < other_last) /* These positions already checked */
1042 must = utf8_target ? other->utf8_substr : other->substr;
1043 assert(SvPOK(must));
1046 char *to = last + SvCUR(must) - (SvTAIL(must)!=0);
1050 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1051 " skipping 'other' fbm scan: %"IVdf" > %"IVdf"\n",
1052 (IV)(from - strbeg),
1058 (unsigned char*)from,
1061 multiline ? FBMrf_MULTILINE : 0
1063 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1064 " doing 'other' fbm scan, [%"IVdf"..%"IVdf"] gave %"IVdf"\n",
1065 (IV)(from - strbeg),
1067 (IV)(s ? s - strbeg : -1)
1073 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
1074 SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
1075 PerlIO_printf(Perl_debug_log, " %s %s substr %s%s",
1076 s ? "Found" : "Contradicts",
1077 other_ix ? "floating" : "anchored",
1078 quoted, RE_SV_TAIL(must));
1083 /* last1 is latest possible substr location. If we didn't
1084 * find it before there, we never will */
1085 if (last >= last1) {
1086 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1087 "; giving up...\n"));
1091 /* try to find the check substr again at a later
1092 * position. Maybe next time we'll find the "other" substr
1094 other_last = HOP3c(last, 1, strend) /* highest failure */;
1096 other_ix /* i.e. if other-is-float */
1097 ? HOP3c(rx_origin, 1, strend)
1098 : HOP4c(last, 1 - other->min_offset, strbeg, strend);
1099 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1100 "; about to retry %s at offset %ld (rx_origin now %"IVdf")...\n",
1101 (other_ix ? "floating" : "anchored"),
1102 (long)(HOP3c(check_at, 1, strend) - strbeg),
1103 (IV)(rx_origin - strbeg)
1108 if (other_ix) { /* if (other-is-float) */
1109 /* other_last is set to s, not s+1, since its possible for
1110 * a floating substr to fail first time, then succeed
1111 * second time at the same floating position; e.g.:
1112 * "-AB--AABZ" =~ /\wAB\d*Z/
1113 * The first time round, anchored and float match at
1114 * "-(AB)--AAB(Z)" then fail on the initial \w character
1115 * class. Second time round, they match at "-AB--A(AB)(Z)".
1120 rx_origin = HOP3c(s, -other->min_offset, strbeg);
1121 other_last = HOP3c(s, 1, strend);
1123 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1124 " at offset %ld (rx_origin now %"IVdf")...\n",
1126 (IV)(rx_origin - strbeg)
1132 DEBUG_OPTIMISE_MORE_r(
1133 PerlIO_printf(Perl_debug_log,
1134 " Check-only match: offset min:%"IVdf" max:%"IVdf
1135 " check_at:%"IVdf" rx_origin:%"IVdf" rx_origin-check_at:%"IVdf
1136 " strend:%"IVdf"\n",
1137 (IV)prog->check_offset_min,
1138 (IV)prog->check_offset_max,
1139 (IV)(check_at-strbeg),
1140 (IV)(rx_origin-strbeg),
1141 (IV)(rx_origin-check_at),
1147 postprocess_substr_matches:
1149 /* handle the extra constraint of /^.../m if present */
1151 if (ml_anch && rx_origin != strbeg && rx_origin[-1] != '\n') {
1154 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1155 " looking for /^/m anchor"));
1157 /* we have failed the constraint of a \n before rx_origin.
1158 * Find the next \n, if any, even if it's beyond the current
1159 * anchored and/or floating substrings. Whether we should be
1160 * scanning ahead for the next \n or the next substr is debatable.
1161 * On the one hand you'd expect rare substrings to appear less
1162 * often than \n's. On the other hand, searching for \n means
1163 * we're effectively flipping between check_substr and "\n" on each
1164 * iteration as the current "rarest" string candidate, which
1165 * means for example that we'll quickly reject the whole string if
1166 * hasn't got a \n, rather than trying every substr position
1170 s = HOP3c(strend, - prog->minlen, strpos);
1171 if (s <= rx_origin ||
1172 ! ( rx_origin = (char *)memchr(rx_origin, '\n', s - rx_origin)))
1174 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1175 " Did not find /%s^%s/m...\n",
1176 PL_colors[0], PL_colors[1]));
1180 /* earliest possible origin is 1 char after the \n.
1181 * (since *rx_origin == '\n', it's safe to ++ here rather than
1182 * HOP(rx_origin, 1)) */
1185 if (prog->substrs->check_ix == 0 /* check is anchored */
1186 || rx_origin >= HOP3c(check_at, - prog->check_offset_min, strpos))
1188 /* Position contradicts check-string; either because
1189 * check was anchored (and thus has no wiggle room),
1190 * or check was float and rx_origin is above the float range */
1191 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1192 " Found /%s^%s/m, about to restart lookup for check-string with rx_origin %ld...\n",
1193 PL_colors[0], PL_colors[1], (long)(rx_origin - strbeg)));
1197 /* if we get here, the check substr must have been float,
1198 * is in range, and we may or may not have had an anchored
1199 * "other" substr which still contradicts */
1200 assert(prog->substrs->check_ix); /* check is float */
1202 if (utf8_target ? prog->anchored_utf8 : prog->anchored_substr) {
1203 /* whoops, the anchored "other" substr exists, so we still
1204 * contradict. On the other hand, the float "check" substr
1205 * didn't contradict, so just retry the anchored "other"
1207 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1208 " Found /%s^%s/m, rescanning for anchored from offset %ld (rx_origin now %"IVdf")...\n",
1209 PL_colors[0], PL_colors[1],
1210 (long)(rx_origin - strbeg + prog->anchored_offset),
1211 (long)(rx_origin - strbeg)
1213 goto do_other_substr;
1216 /* success: we don't contradict the found floating substring
1217 * (and there's no anchored substr). */
1218 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1219 " Found /%s^%s/m with rx_origin %ld...\n",
1220 PL_colors[0], PL_colors[1], (long)(rx_origin - strbeg)));
1223 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1224 " (multiline anchor test skipped)\n"));
1230 /* if we have a starting character class, then test that extra constraint.
1231 * (trie stclasses are too expensive to use here, we are better off to
1232 * leave it to regmatch itself) */
1234 if (progi->regstclass && PL_regkind[OP(progi->regstclass)]!=TRIE) {
1235 const U8* const str = (U8*)STRING(progi->regstclass);
1237 /* XXX this value could be pre-computed */
1238 const int cl_l = (PL_regkind[OP(progi->regstclass)] == EXACT
1239 ? (reginfo->is_utf8_pat
1240 ? utf8_distance(str + STR_LEN(progi->regstclass), str)
1241 : STR_LEN(progi->regstclass))
1245 /* latest pos that a matching float substr constrains rx start to */
1246 char *rx_max_float = NULL;
1248 /* if the current rx_origin is anchored, either by satisfying an
1249 * anchored substring constraint, or a /^.../m constraint, then we
1250 * can reject the current origin if the start class isn't found
1251 * at the current position. If we have a float-only match, then
1252 * rx_origin is constrained to a range; so look for the start class
1253 * in that range. if neither, then look for the start class in the
1254 * whole rest of the string */
1256 /* XXX DAPM it's not clear what the minlen test is for, and why
1257 * it's not used in the floating case. Nothing in the test suite
1258 * causes minlen == 0 here. See <20140313134639.GS12844@iabyn.com>.
1259 * Here are some old comments, which may or may not be correct:
1261 * minlen == 0 is possible if regstclass is \b or \B,
1262 * and the fixed substr is ''$.
1263 * Since minlen is already taken into account, rx_origin+1 is
1264 * before strend; accidentally, minlen >= 1 guaranties no false
1265 * positives at rx_origin + 1 even for \b or \B. But (minlen? 1 :
1266 * 0) below assumes that regstclass does not come from lookahead...
1267 * If regstclass takes bytelength more than 1: If charlength==1, OK.
1268 * This leaves EXACTF-ish only, which are dealt with in
1272 if (prog->anchored_substr || prog->anchored_utf8 || ml_anch)
1273 endpos= HOP3c(rx_origin, (prog->minlen ? cl_l : 0), strend);
1274 else if (prog->float_substr || prog->float_utf8) {
1275 rx_max_float = HOP3c(check_at, -start_shift, strbeg);
1276 endpos= HOP3c(rx_max_float, cl_l, strend);
1281 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1282 " looking for class: start_shift: %"IVdf" check_at: %"IVdf
1283 " rx_origin: %"IVdf" endpos: %"IVdf"\n",
1284 (IV)start_shift, (IV)(check_at - strbeg),
1285 (IV)(rx_origin - strbeg), (IV)(endpos - strbeg)));
1287 s = find_byclass(prog, progi->regstclass, rx_origin, endpos,
1290 if (endpos == strend) {
1291 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1292 " Could not match STCLASS...\n") );
1295 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1296 " This position contradicts STCLASS...\n") );
1297 if ((prog->intflags & PREGf_ANCH) && !ml_anch
1298 && !(prog->intflags & PREGf_IMPLICIT))
1301 /* Contradict one of substrings */
1302 if (prog->anchored_substr || prog->anchored_utf8) {
1303 if (prog->substrs->check_ix == 1) { /* check is float */
1304 /* Have both, check_string is floating */
1305 assert(rx_origin + start_shift <= check_at);
1306 if (rx_origin + start_shift != check_at) {
1307 /* not at latest position float substr could match:
1308 * Recheck anchored substring, but not floating.
1309 * The condition above is in bytes rather than
1310 * chars for efficiency. It's conservative, in
1311 * that it errs on the side of doing 'goto
1312 * do_other_substr'. In this case, at worst,
1313 * an extra anchored search may get done, but in
1314 * practice the extra fbm_instr() is likely to
1315 * get skipped anyway. */
1316 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1317 " about to retry anchored at offset %ld (rx_origin now %"IVdf")...\n",
1318 (long)(other_last - strbeg),
1319 (IV)(rx_origin - strbeg)
1321 goto do_other_substr;
1329 /* In the presence of ml_anch, we might be able to
1330 * find another \n without breaking the current float
1333 /* strictly speaking this should be HOP3c(..., 1, ...),
1334 * but since we goto a block of code that's going to
1335 * search for the next \n if any, its safe here */
1337 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1338 " about to look for /%s^%s/m starting at rx_origin %ld...\n",
1339 PL_colors[0], PL_colors[1],
1340 (long)(rx_origin - strbeg)) );
1341 goto postprocess_substr_matches;
1344 /* strictly speaking this can never be true; but might
1345 * be if we ever allow intuit without substrings */
1346 if (!(utf8_target ? prog->float_utf8 : prog->float_substr))
1349 rx_origin = rx_max_float;
1352 /* at this point, any matching substrings have been
1353 * contradicted. Start again... */
1355 rx_origin = HOP3c(rx_origin, 1, strend);
1357 /* uses bytes rather than char calculations for efficiency.
1358 * It's conservative: it errs on the side of doing 'goto restart',
1359 * where there is code that does a proper char-based test */
1360 if (rx_origin + start_shift + end_shift > strend) {
1361 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1362 " Could not match STCLASS...\n") );
1365 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
1366 " about to look for %s substr starting at offset %ld (rx_origin now %"IVdf")...\n",
1367 (prog->substrs->check_ix ? "floating" : "anchored"),
1368 (long)(rx_origin + start_shift - strbeg),
1369 (IV)(rx_origin - strbeg)
1376 if (rx_origin != s) {
1377 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1378 " By STCLASS: moving %ld --> %ld\n",
1379 (long)(rx_origin - strbeg), (long)(s - strbeg))
1383 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1384 " Does not contradict STCLASS...\n");
1389 /* Decide whether using the substrings helped */
1391 if (rx_origin != strpos) {
1392 /* Fixed substring is found far enough so that the match
1393 cannot start at strpos. */
1395 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, " try at offset...\n"));
1396 ++BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr); /* hooray/5 */
1399 /* The found rx_origin position does not prohibit matching at
1400 * strpos, so calling intuit didn't gain us anything. Decrement
1401 * the BmUSEFUL() count on the check substring, and if we reach
1403 if (!(prog->intflags & PREGf_NAUGHTY)
1405 prog->check_utf8 /* Could be deleted already */
1406 && --BmUSEFUL(prog->check_utf8) < 0
1407 && (prog->check_utf8 == prog->float_utf8)
1409 prog->check_substr /* Could be deleted already */
1410 && --BmUSEFUL(prog->check_substr) < 0
1411 && (prog->check_substr == prog->float_substr)
1414 /* If flags & SOMETHING - do not do it many times on the same match */
1415 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, " ... Disabling check substring...\n"));
1416 /* XXX Does the destruction order has to change with utf8_target? */
1417 SvREFCNT_dec(utf8_target ? prog->check_utf8 : prog->check_substr);
1418 SvREFCNT_dec(utf8_target ? prog->check_substr : prog->check_utf8);
1419 prog->check_substr = prog->check_utf8 = NULL; /* disable */
1420 prog->float_substr = prog->float_utf8 = NULL; /* clear */
1421 check = NULL; /* abort */
1422 /* XXXX This is a remnant of the old implementation. It
1423 looks wasteful, since now INTUIT can use many
1424 other heuristics. */
1425 prog->extflags &= ~RXf_USE_INTUIT;
1429 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1430 "Intuit: %sSuccessfully guessed:%s match at offset %ld\n",
1431 PL_colors[4], PL_colors[5], (long)(rx_origin - strbeg)) );
1435 fail_finish: /* Substring not found */
1436 if (prog->check_substr || prog->check_utf8) /* could be removed already */
1437 BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr) += 5; /* hooray */
1439 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch rejected by optimizer%s\n",
1440 PL_colors[4], PL_colors[5]));
1445 #define DECL_TRIE_TYPE(scan) \
1446 const enum { trie_plain, trie_utf8, trie_utf8_fold, trie_latin_utf8_fold, \
1447 trie_utf8_exactfa_fold, trie_latin_utf8_exactfa_fold, \
1448 trie_utf8l, trie_flu8 } \
1449 trie_type = ((scan->flags == EXACT) \
1450 ? (utf8_target ? trie_utf8 : trie_plain) \
1451 : (scan->flags == EXACTL) \
1452 ? (utf8_target ? trie_utf8l : trie_plain) \
1453 : (scan->flags == EXACTFA) \
1455 ? trie_utf8_exactfa_fold \
1456 : trie_latin_utf8_exactfa_fold) \
1457 : (scan->flags == EXACTFLU8 \
1461 : trie_latin_utf8_fold)))
1463 #define REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc, uscan, len, uvc, charid, foldlen, foldbuf, uniflags) \
1466 U8 flags = FOLD_FLAGS_FULL; \
1467 switch (trie_type) { \
1469 _CHECK_AND_WARN_PROBLEMATIC_LOCALE; \
1470 if (utf8_target && UTF8_IS_ABOVE_LATIN1(*uc)) { \
1471 _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(uc, uc + UTF8SKIP(uc)); \
1473 goto do_trie_utf8_fold; \
1474 case trie_utf8_exactfa_fold: \
1475 flags |= FOLD_FLAGS_NOMIX_ASCII; \
1477 case trie_utf8_fold: \
1478 do_trie_utf8_fold: \
1479 if ( foldlen>0 ) { \
1480 uvc = utf8n_to_uvchr( (const U8*) uscan, UTF8_MAXLEN, &len, uniflags ); \
1485 uvc = _to_utf8_fold_flags( (const U8*) uc, foldbuf, &foldlen, flags); \
1486 len = UTF8SKIP(uc); \
1487 skiplen = UVCHR_SKIP( uvc ); \
1488 foldlen -= skiplen; \
1489 uscan = foldbuf + skiplen; \
1492 case trie_latin_utf8_exactfa_fold: \
1493 flags |= FOLD_FLAGS_NOMIX_ASCII; \
1495 case trie_latin_utf8_fold: \
1496 if ( foldlen>0 ) { \
1497 uvc = utf8n_to_uvchr( (const U8*) uscan, UTF8_MAXLEN, &len, uniflags ); \
1503 uvc = _to_fold_latin1( (U8) *uc, foldbuf, &foldlen, flags); \
1504 skiplen = UVCHR_SKIP( uvc ); \
1505 foldlen -= skiplen; \
1506 uscan = foldbuf + skiplen; \
1510 _CHECK_AND_WARN_PROBLEMATIC_LOCALE; \
1511 if (utf8_target && UTF8_IS_ABOVE_LATIN1(*uc)) { \
1512 _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(uc, uc + UTF8SKIP(uc)); \
1516 uvc = utf8n_to_uvchr( (const U8*) uc, UTF8_MAXLEN, &len, uniflags ); \
1523 charid = trie->charmap[ uvc ]; \
1527 if (widecharmap) { \
1528 SV** const svpp = hv_fetch(widecharmap, \
1529 (char*)&uvc, sizeof(UV), 0); \
1531 charid = (U16)SvIV(*svpp); \
1536 #define DUMP_EXEC_POS(li,s,doutf8) \
1537 dump_exec_pos(li,s,(reginfo->strend),(reginfo->strbeg), \
1540 #define REXEC_FBC_EXACTISH_SCAN(COND) \
1544 && (ln == 1 || folder(s, pat_string, ln)) \
1545 && (reginfo->intuit || regtry(reginfo, &s)) )\
1551 #define REXEC_FBC_UTF8_SCAN(CODE) \
1553 while (s < strend) { \
1559 #define REXEC_FBC_SCAN(CODE) \
1561 while (s < strend) { \
1567 #define REXEC_FBC_UTF8_CLASS_SCAN(COND) \
1568 REXEC_FBC_UTF8_SCAN( /* Loops while (s < strend) */ \
1570 if (tmp && (reginfo->intuit || regtry(reginfo, &s))) \
1579 #define REXEC_FBC_CLASS_SCAN(COND) \
1580 REXEC_FBC_SCAN( /* Loops while (s < strend) */ \
1582 if (tmp && (reginfo->intuit || regtry(reginfo, &s))) \
1591 #define REXEC_FBC_CSCAN(CONDUTF8,COND) \
1592 if (utf8_target) { \
1593 REXEC_FBC_UTF8_CLASS_SCAN(CONDUTF8); \
1596 REXEC_FBC_CLASS_SCAN(COND); \
1599 /* The three macros below are slightly different versions of the same logic.
1601 * The first is for /a and /aa when the target string is UTF-8. This can only
1602 * match ascii, but it must advance based on UTF-8. The other two handle the
1603 * non-UTF-8 and the more generic UTF-8 cases. In all three, we are looking
1604 * for the boundary (or non-boundary) between a word and non-word character.
1605 * The utf8 and non-utf8 cases have the same logic, but the details must be
1606 * different. Find the "wordness" of the character just prior to this one, and
1607 * compare it with the wordness of this one. If they differ, we have a
1608 * boundary. At the beginning of the string, pretend that the previous
1609 * character was a new-line.
1611 * All these macros uncleanly have side-effects with each other and outside
1612 * variables. So far it's been too much trouble to clean-up
1614 * TEST_NON_UTF8 is the macro or function to call to test if its byte input is
1615 * a word character or not.
1616 * IF_SUCCESS is code to do if it finds that we are at a boundary between
1618 * IF_FAIL is code to do if we aren't at a boundary between word/non-word
1620 * Exactly one of the two IF_FOO parameters is a no-op, depending on whether we
1621 * are looking for a boundary or for a non-boundary. If we are looking for a
1622 * boundary, we want IF_FAIL to be the no-op, and for IF_SUCCESS to go out and
1623 * see if this tentative match actually works, and if so, to quit the loop
1624 * here. And vice-versa if we are looking for a non-boundary.
1626 * 'tmp' below in the next three macros in the REXEC_FBC_SCAN and
1627 * REXEC_FBC_UTF8_SCAN loops is a loop invariant, a bool giving the return of
1628 * TEST_NON_UTF8(s-1). To see this, note that that's what it is defined to be
1629 * at entry to the loop, and to get to the IF_FAIL branch, tmp must equal
1630 * TEST_NON_UTF8(s), and in the opposite branch, IF_SUCCESS, tmp is that
1631 * complement. But in that branch we complement tmp, meaning that at the
1632 * bottom of the loop tmp is always going to be equal to TEST_NON_UTF8(s),
1633 * which means at the top of the loop in the next iteration, it is
1634 * TEST_NON_UTF8(s-1) */
1635 #define FBC_UTF8_A(TEST_NON_UTF8, IF_SUCCESS, IF_FAIL) \
1636 tmp = (s != reginfo->strbeg) ? UCHARAT(s - 1) : '\n'; \
1637 tmp = TEST_NON_UTF8(tmp); \
1638 REXEC_FBC_UTF8_SCAN( /* advances s while s < strend */ \
1639 if (tmp == ! TEST_NON_UTF8((U8) *s)) { \
1641 IF_SUCCESS; /* Is a boundary if values for s-1 and s differ */ \
1648 /* Like FBC_UTF8_A, but TEST_UV is a macro which takes a UV as its input, and
1649 * TEST_UTF8 is a macro that for the same input code points returns identically
1650 * to TEST_UV, but takes a pointer to a UTF-8 encoded string instead */
1651 #define FBC_UTF8(TEST_UV, TEST_UTF8, IF_SUCCESS, IF_FAIL) \
1652 if (s == reginfo->strbeg) { \
1655 else { /* Back-up to the start of the previous character */ \
1656 U8 * const r = reghop3((U8*)s, -1, (U8*)reginfo->strbeg); \
1657 tmp = utf8n_to_uvchr(r, (U8*) reginfo->strend - r, \
1658 0, UTF8_ALLOW_DEFAULT); \
1660 tmp = TEST_UV(tmp); \
1661 LOAD_UTF8_CHARCLASS_ALNUM(); \
1662 REXEC_FBC_UTF8_SCAN( /* advances s while s < strend */ \
1663 if (tmp == ! (TEST_UTF8((U8 *) s))) { \
1672 /* Like the above two macros. UTF8_CODE is the complete code for handling
1673 * UTF-8. Common to the BOUND and NBOUND cases, set-up by the FBC_BOUND, etc
1675 #define FBC_BOUND_COMMON(UTF8_CODE, TEST_NON_UTF8, IF_SUCCESS, IF_FAIL) \
1676 if (utf8_target) { \
1679 else { /* Not utf8 */ \
1680 tmp = (s != reginfo->strbeg) ? UCHARAT(s - 1) : '\n'; \
1681 tmp = TEST_NON_UTF8(tmp); \
1682 REXEC_FBC_SCAN( /* advances s while s < strend */ \
1683 if (tmp == ! TEST_NON_UTF8((U8) *s)) { \
1692 /* Here, things have been set up by the previous code so that tmp is the \
1693 * return of TEST_NON_UTF(s-1) or TEST_UTF8(s-1) (depending on the \
1694 * utf8ness of the target). We also have to check if this matches against \
1695 * the EOS, which we treat as a \n (which is the same value in both UTF-8 \
1696 * or non-UTF8, so can use the non-utf8 test condition even for a UTF-8 \
1698 if (tmp == ! TEST_NON_UTF8('\n')) { \
1705 /* This is the macro to use when we want to see if something that looks like it
1706 * could match, actually does, and if so exits the loop */
1707 #define REXEC_FBC_TRYIT \
1708 if ((reginfo->intuit || regtry(reginfo, &s))) \
1711 /* The only difference between the BOUND and NBOUND cases is that
1712 * REXEC_FBC_TRYIT is called when matched in BOUND, and when non-matched in
1713 * NBOUND. This is accomplished by passing it as either the if or else clause,
1714 * with the other one being empty (PLACEHOLDER is defined as empty).
1716 * The TEST_FOO parameters are for operating on different forms of input, but
1717 * all should be ones that return identically for the same underlying code
1719 #define FBC_BOUND(TEST_NON_UTF8, TEST_UV, TEST_UTF8) \
1721 FBC_UTF8(TEST_UV, TEST_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER), \
1722 TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER)
1724 #define FBC_BOUND_A(TEST_NON_UTF8) \
1726 FBC_UTF8_A(TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER), \
1727 TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER)
1729 #define FBC_NBOUND(TEST_NON_UTF8, TEST_UV, TEST_UTF8) \
1731 FBC_UTF8(TEST_UV, TEST_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT), \
1732 TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT)
1734 #define FBC_NBOUND_A(TEST_NON_UTF8) \
1736 FBC_UTF8_A(TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT), \
1737 TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT)
1739 /* Takes a pointer to an inversion list, a pointer to its corresponding
1740 * inversion map, and a code point, and returns the code point's value
1741 * according to the two arrays. It assumes that all code points have a value.
1742 * This is used as the base macro for macros for particular properties */
1743 #define _generic_GET_BREAK_VAL_CP(invlist, invmap, cp) \
1744 invmap[_invlist_search(invlist, cp)]
1746 /* Same as above, but takes begin, end ptrs to a UTF-8 encoded string instead
1747 * of a code point, returning the value for the first code point in the string.
1748 * And it takes the particular macro name that finds the desired value given a
1749 * code point. Merely convert the UTF-8 to code point and call the cp macro */
1750 #define _generic_GET_BREAK_VAL_UTF8(cp_macro, pos, strend) \
1751 (__ASSERT_(pos < strend) \
1752 /* Note assumes is valid UTF-8 */ \
1753 (cp_macro(utf8_to_uvchr_buf((pos), (strend), NULL))))
1755 /* Returns the GCB value for the input code point */
1756 #define getGCB_VAL_CP(cp) \
1757 _generic_GET_BREAK_VAL_CP( \
1762 /* Returns the GCB value for the first code point in the UTF-8 encoded string
1763 * bounded by pos and strend */
1764 #define getGCB_VAL_UTF8(pos, strend) \
1765 _generic_GET_BREAK_VAL_UTF8(getGCB_VAL_CP, pos, strend)
1768 /* Returns the SB value for the input code point */
1769 #define getSB_VAL_CP(cp) \
1770 _generic_GET_BREAK_VAL_CP( \
1775 /* Returns the SB value for the first code point in the UTF-8 encoded string
1776 * bounded by pos and strend */
1777 #define getSB_VAL_UTF8(pos, strend) \
1778 _generic_GET_BREAK_VAL_UTF8(getSB_VAL_CP, pos, strend)
1780 /* Returns the WB value for the input code point */
1781 #define getWB_VAL_CP(cp) \
1782 _generic_GET_BREAK_VAL_CP( \
1787 /* Returns the WB value for the first code point in the UTF-8 encoded string
1788 * bounded by pos and strend */
1789 #define getWB_VAL_UTF8(pos, strend) \
1790 _generic_GET_BREAK_VAL_UTF8(getWB_VAL_CP, pos, strend)
1792 /* We know what class REx starts with. Try to find this position... */
1793 /* if reginfo->intuit, its a dryrun */
1794 /* annoyingly all the vars in this routine have different names from their counterparts
1795 in regmatch. /grrr */
1797 S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s,
1798 const char *strend, regmatch_info *reginfo)
1801 const I32 doevery = (prog->intflags & PREGf_SKIP) == 0;
1802 char *pat_string; /* The pattern's exactish string */
1803 char *pat_end; /* ptr to end char of pat_string */
1804 re_fold_t folder; /* Function for computing non-utf8 folds */
1805 const U8 *fold_array; /* array for folding ords < 256 */
1811 I32 tmp = 1; /* Scratch variable? */
1812 const bool utf8_target = reginfo->is_utf8_target;
1813 UV utf8_fold_flags = 0;
1814 const bool is_utf8_pat = reginfo->is_utf8_pat;
1815 bool to_complement = FALSE; /* Invert the result? Taking the xor of this
1816 with a result inverts that result, as 0^1 =
1818 _char_class_number classnum;
1820 RXi_GET_DECL(prog,progi);
1822 PERL_ARGS_ASSERT_FIND_BYCLASS;
1824 /* We know what class it must start with. */
1827 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
1829 if ((FLAGS(c) & ANYOF_LOC_REQ_UTF8) && ! IN_UTF8_CTYPE_LOCALE) {
1830 Perl_ck_warner(aTHX_ packWARN(WARN_LOCALE), utf8_locale_required);
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));
1845 case EXACTFA_NO_TRIE: /* This node only generated for non-utf8 patterns */
1846 assert(! is_utf8_pat);
1849 if (is_utf8_pat || utf8_target) {
1850 utf8_fold_flags = FOLDEQ_UTF8_NOMIX_ASCII;
1851 goto do_exactf_utf8;
1853 fold_array = PL_fold_latin1; /* Latin1 folds are not affected by */
1854 folder = foldEQ_latin1; /* /a, except the sharp s one which */
1855 goto do_exactf_non_utf8; /* isn't dealt with by these */
1857 case EXACTF: /* This node only generated for non-utf8 patterns */
1858 assert(! is_utf8_pat);
1860 utf8_fold_flags = 0;
1861 goto do_exactf_utf8;
1863 fold_array = PL_fold;
1865 goto do_exactf_non_utf8;
1868 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
1869 if (is_utf8_pat || utf8_target || IN_UTF8_CTYPE_LOCALE) {
1870 utf8_fold_flags = FOLDEQ_LOCALE;
1871 goto do_exactf_utf8;
1873 fold_array = PL_fold_locale;
1874 folder = foldEQ_locale;
1875 goto do_exactf_non_utf8;
1879 utf8_fold_flags = FOLDEQ_S2_ALREADY_FOLDED;
1881 goto do_exactf_utf8;
1884 if (! utf8_target) { /* All code points in this node require
1885 UTF-8 to express. */
1888 utf8_fold_flags = FOLDEQ_LOCALE | FOLDEQ_S2_ALREADY_FOLDED
1889 | FOLDEQ_S2_FOLDS_SANE;
1890 goto do_exactf_utf8;
1893 if (is_utf8_pat || utf8_target) {
1894 utf8_fold_flags = is_utf8_pat ? FOLDEQ_S2_ALREADY_FOLDED : 0;
1895 goto do_exactf_utf8;
1898 /* Any 'ss' in the pattern should have been replaced by regcomp,
1899 * so we don't have to worry here about this single special case
1900 * in the Latin1 range */
1901 fold_array = PL_fold_latin1;
1902 folder = foldEQ_latin1;
1906 do_exactf_non_utf8: /* Neither pattern nor string are UTF8, and there
1907 are no glitches with fold-length differences
1908 between the target string and pattern */
1910 /* The idea in the non-utf8 EXACTF* cases is to first find the
1911 * first character of the EXACTF* node and then, if necessary,
1912 * case-insensitively compare the full text of the node. c1 is the
1913 * first character. c2 is its fold. This logic will not work for
1914 * Unicode semantics and the german sharp ss, which hence should
1915 * not be compiled into a node that gets here. */
1916 pat_string = STRING(c);
1917 ln = STR_LEN(c); /* length to match in octets/bytes */
1919 /* We know that we have to match at least 'ln' bytes (which is the
1920 * same as characters, since not utf8). If we have to match 3
1921 * characters, and there are only 2 availabe, we know without
1922 * trying that it will fail; so don't start a match past the
1923 * required minimum number from the far end */
1924 e = HOP3c(strend, -((SSize_t)ln), s);
1926 if (reginfo->intuit && e < s) {
1927 e = s; /* Due to minlen logic of intuit() */
1931 c2 = fold_array[c1];
1932 if (c1 == c2) { /* If char and fold are the same */
1933 REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1);
1936 REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1 || *(U8*)s == c2);
1944 /* If one of the operands is in utf8, we can't use the simpler folding
1945 * above, due to the fact that many different characters can have the
1946 * same fold, or portion of a fold, or different- length fold */
1947 pat_string = STRING(c);
1948 ln = STR_LEN(c); /* length to match in octets/bytes */
1949 pat_end = pat_string + ln;
1950 lnc = is_utf8_pat /* length to match in characters */
1951 ? utf8_length((U8 *) pat_string, (U8 *) pat_end)
1954 /* We have 'lnc' characters to match in the pattern, but because of
1955 * multi-character folding, each character in the target can match
1956 * up to 3 characters (Unicode guarantees it will never exceed
1957 * this) if it is utf8-encoded; and up to 2 if not (based on the
1958 * fact that the Latin 1 folds are already determined, and the
1959 * only multi-char fold in that range is the sharp-s folding to
1960 * 'ss'. Thus, a pattern character can match as little as 1/3 of a
1961 * string character. Adjust lnc accordingly, rounding up, so that
1962 * if we need to match at least 4+1/3 chars, that really is 5. */
1963 expansion = (utf8_target) ? UTF8_MAX_FOLD_CHAR_EXPAND : 2;
1964 lnc = (lnc + expansion - 1) / expansion;
1966 /* As in the non-UTF8 case, if we have to match 3 characters, and
1967 * only 2 are left, it's guaranteed to fail, so don't start a
1968 * match that would require us to go beyond the end of the string
1970 e = HOP3c(strend, -((SSize_t)lnc), s);
1972 if (reginfo->intuit && e < s) {
1973 e = s; /* Due to minlen logic of intuit() */
1976 /* XXX Note that we could recalculate e to stop the loop earlier,
1977 * as the worst case expansion above will rarely be met, and as we
1978 * go along we would usually find that e moves further to the left.
1979 * This would happen only after we reached the point in the loop
1980 * where if there were no expansion we should fail. Unclear if
1981 * worth the expense */
1984 char *my_strend= (char *)strend;
1985 if (foldEQ_utf8_flags(s, &my_strend, 0, utf8_target,
1986 pat_string, NULL, ln, is_utf8_pat, utf8_fold_flags)
1987 && (reginfo->intuit || regtry(reginfo, &s)) )
1991 s += (utf8_target) ? UTF8SKIP(s) : 1;
1997 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
1998 if (FLAGS(c) != TRADITIONAL_BOUND) {
1999 if (! IN_UTF8_CTYPE_LOCALE) {
2000 Perl_ck_warner(aTHX_ packWARN(WARN_LOCALE),
2001 B_ON_NON_UTF8_LOCALE_IS_WRONG);
2006 FBC_BOUND(isWORDCHAR_LC, isWORDCHAR_LC_uvchr, isWORDCHAR_LC_utf8);
2010 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
2011 if (FLAGS(c) != TRADITIONAL_BOUND) {
2012 if (! IN_UTF8_CTYPE_LOCALE) {
2013 Perl_ck_warner(aTHX_ packWARN(WARN_LOCALE),
2014 B_ON_NON_UTF8_LOCALE_IS_WRONG);
2019 FBC_NBOUND(isWORDCHAR_LC, isWORDCHAR_LC_uvchr, isWORDCHAR_LC_utf8);
2022 case BOUND: /* regcomp.c makes sure that this only has the traditional \b
2024 assert(FLAGS(c) == TRADITIONAL_BOUND);
2026 FBC_BOUND(isWORDCHAR, isWORDCHAR_uni, isWORDCHAR_utf8);
2029 case BOUNDA: /* regcomp.c makes sure that this only has the traditional \b
2031 assert(FLAGS(c) == TRADITIONAL_BOUND);
2033 FBC_BOUND_A(isWORDCHAR_A);
2036 case NBOUND: /* regcomp.c makes sure that this only has the traditional \b
2038 assert(FLAGS(c) == TRADITIONAL_BOUND);
2040 FBC_NBOUND(isWORDCHAR, isWORDCHAR_uni, isWORDCHAR_utf8);
2043 case NBOUNDA: /* regcomp.c makes sure that this only has the traditional \b
2045 assert(FLAGS(c) == TRADITIONAL_BOUND);
2047 FBC_NBOUND_A(isWORDCHAR_A);
2051 if ((bound_type) FLAGS(c) == TRADITIONAL_BOUND) {
2052 FBC_NBOUND(isWORDCHAR_L1, isWORDCHAR_uni, isWORDCHAR_utf8);
2063 switch((bound_type) FLAGS(c)) {
2064 case TRADITIONAL_BOUND:
2065 FBC_BOUND(isWORDCHAR_L1, isWORDCHAR_uni, isWORDCHAR_utf8);
2068 if (s == reginfo->strbeg) { /* GCB always matches at begin and
2070 if (to_complement ^ cBOOL(reginfo->intuit
2071 || regtry(reginfo, &s)))
2075 s += (utf8_target) ? UTF8SKIP(s) : 1;
2079 GCB_enum before = getGCB_VAL_UTF8(
2081 (U8*)(reginfo->strbeg)),
2082 (U8*) reginfo->strend);
2083 while (s < strend) {
2084 GCB_enum after = getGCB_VAL_UTF8((U8*) s,
2085 (U8*) reginfo->strend);
2086 if (to_complement ^ isGCB(before, after)) {
2087 if (reginfo->intuit || regtry(reginfo, &s)) {
2095 else { /* Not utf8. Everything is a GCB except between CR and
2097 while (s < strend) {
2098 if (to_complement ^ (UCHARAT(s - 1) != '\r'
2099 || UCHARAT(s) != '\n'))
2101 if (reginfo->intuit || regtry(reginfo, &s)) {
2109 if (to_complement ^ cBOOL(reginfo->intuit || regtry(reginfo, &s))) {
2115 if (s == reginfo->strbeg) { /* SB always matches at beginning */
2117 ^ cBOOL(reginfo->intuit || regtry(reginfo, &s)))
2122 /* Didn't match. Go try at the next position */
2123 s += (utf8_target) ? UTF8SKIP(s) : 1;
2127 SB_enum before = getSB_VAL_UTF8(reghop3((U8*)s,
2129 (U8*)(reginfo->strbeg)),
2130 (U8*) reginfo->strend);
2131 while (s < strend) {
2132 SB_enum after = getSB_VAL_UTF8((U8*) s,
2133 (U8*) reginfo->strend);
2134 if (to_complement ^ isSB(before,
2136 (U8*) reginfo->strbeg,
2138 (U8*) reginfo->strend,
2141 if (reginfo->intuit || regtry(reginfo, &s)) {
2149 else { /* Not utf8. */
2150 SB_enum before = getSB_VAL_CP((U8) *(s -1));
2151 while (s < strend) {
2152 SB_enum after = getSB_VAL_CP((U8) *s);
2153 if (to_complement ^ isSB(before,
2155 (U8*) reginfo->strbeg,
2157 (U8*) reginfo->strend,
2160 if (reginfo->intuit || regtry(reginfo, &s)) {
2169 /* Here are at the final position in the target string. The SB
2170 * value is always true here, so matches, depending on other
2172 if (to_complement ^ cBOOL(reginfo->intuit
2173 || regtry(reginfo, &s)))
2181 if (s == reginfo->strbeg) {
2182 if (to_complement ^ cBOOL(reginfo->intuit
2183 || regtry(reginfo, &s)))
2187 s += (utf8_target) ? UTF8SKIP(s) : 1;
2191 /* We are at a boundary between char_sub_0 and char_sub_1.
2192 * We also keep track of the value for char_sub_-1 as we
2193 * loop through the line. Context may be needed to make a
2194 * determination, and if so, this can save having to
2196 WB_enum previous = WB_UNKNOWN;
2197 WB_enum before = getWB_VAL_UTF8(
2200 (U8*)(reginfo->strbeg)),
2201 (U8*) reginfo->strend);
2202 while (s < strend) {
2203 WB_enum after = getWB_VAL_UTF8((U8*) s,
2204 (U8*) reginfo->strend);
2205 if (to_complement ^ isWB(previous,
2208 (U8*) reginfo->strbeg,
2210 (U8*) reginfo->strend,
2213 if (reginfo->intuit || regtry(reginfo, &s)) {
2222 else { /* Not utf8. */
2223 WB_enum previous = WB_UNKNOWN;
2224 WB_enum before = getWB_VAL_CP((U8) *(s -1));
2225 while (s < strend) {
2226 WB_enum after = getWB_VAL_CP((U8) *s);
2227 if (to_complement ^ isWB(previous,
2230 (U8*) reginfo->strbeg,
2232 (U8*) reginfo->strend,
2235 if (reginfo->intuit || regtry(reginfo, &s)) {
2245 if (to_complement ^ cBOOL(reginfo->intuit
2246 || regtry(reginfo, &s)))
2256 REXEC_FBC_CSCAN(is_LNBREAK_utf8_safe(s, strend),
2257 is_LNBREAK_latin1_safe(s, strend)
2261 /* The argument to all the POSIX node types is the class number to pass to
2262 * _generic_isCC() to build a mask for searching in PL_charclass[] */
2269 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
2270 REXEC_FBC_CSCAN(to_complement ^ cBOOL(isFOO_utf8_lc(FLAGS(c), (U8 *) s)),
2271 to_complement ^ cBOOL(isFOO_lc(FLAGS(c), *s)));
2286 /* The complement of something that matches only ASCII matches all
2287 * non-ASCII, plus everything in ASCII that isn't in the class. */
2288 REXEC_FBC_UTF8_CLASS_SCAN(! isASCII_utf8(s)
2289 || ! _generic_isCC_A(*s, FLAGS(c)));
2298 /* Don't need to worry about utf8, as it can match only a single
2299 * byte invariant character. */
2300 REXEC_FBC_CLASS_SCAN(
2301 to_complement ^ cBOOL(_generic_isCC_A(*s, FLAGS(c))));
2309 if (! utf8_target) {
2310 REXEC_FBC_CLASS_SCAN(to_complement ^ cBOOL(_generic_isCC(*s,
2316 classnum = (_char_class_number) FLAGS(c);
2317 if (classnum < _FIRST_NON_SWASH_CC) {
2318 while (s < strend) {
2320 /* We avoid loading in the swash as long as possible, but
2321 * should we have to, we jump to a separate loop. This
2322 * extra 'if' statement is what keeps this code from being
2323 * just a call to REXEC_FBC_UTF8_CLASS_SCAN() */
2324 if (UTF8_IS_ABOVE_LATIN1(*s)) {
2325 goto found_above_latin1;
2327 if ((UTF8_IS_INVARIANT(*s)
2328 && to_complement ^ cBOOL(_generic_isCC((U8) *s,
2330 || (UTF8_IS_DOWNGRADEABLE_START(*s)
2331 && to_complement ^ cBOOL(
2332 _generic_isCC(EIGHT_BIT_UTF8_TO_NATIVE(*s,
2336 if (tmp && (reginfo->intuit || regtry(reginfo, &s)))
2348 else switch (classnum) { /* These classes are implemented as
2350 case _CC_ENUM_SPACE:
2351 REXEC_FBC_UTF8_CLASS_SCAN(
2352 to_complement ^ cBOOL(isSPACE_utf8(s)));
2355 case _CC_ENUM_BLANK:
2356 REXEC_FBC_UTF8_CLASS_SCAN(
2357 to_complement ^ cBOOL(isBLANK_utf8(s)));
2360 case _CC_ENUM_XDIGIT:
2361 REXEC_FBC_UTF8_CLASS_SCAN(
2362 to_complement ^ cBOOL(isXDIGIT_utf8(s)));
2365 case _CC_ENUM_VERTSPACE:
2366 REXEC_FBC_UTF8_CLASS_SCAN(
2367 to_complement ^ cBOOL(isVERTWS_utf8(s)));
2370 case _CC_ENUM_CNTRL:
2371 REXEC_FBC_UTF8_CLASS_SCAN(
2372 to_complement ^ cBOOL(isCNTRL_utf8(s)));
2376 Perl_croak(aTHX_ "panic: find_byclass() node %d='%s' has an unexpected character class '%d'", OP(c), PL_reg_name[OP(c)], classnum);
2377 NOT_REACHED; /* NOTREACHED */
2382 found_above_latin1: /* Here we have to load a swash to get the result
2383 for the current code point */
2384 if (! PL_utf8_swash_ptrs[classnum]) {
2385 U8 flags = _CORE_SWASH_INIT_ACCEPT_INVLIST;
2386 PL_utf8_swash_ptrs[classnum] =
2387 _core_swash_init("utf8",
2390 PL_XPosix_ptrs[classnum], &flags);
2393 /* This is a copy of the loop above for swash classes, though using the
2394 * FBC macro instead of being expanded out. Since we've loaded the
2395 * swash, we don't have to check for that each time through the loop */
2396 REXEC_FBC_UTF8_CLASS_SCAN(
2397 to_complement ^ cBOOL(_generic_utf8(
2400 swash_fetch(PL_utf8_swash_ptrs[classnum],
2408 /* what trie are we using right now */
2409 reg_ac_data *aho = (reg_ac_data*)progi->data->data[ ARG( c ) ];
2410 reg_trie_data *trie = (reg_trie_data*)progi->data->data[ aho->trie ];
2411 HV *widecharmap = MUTABLE_HV(progi->data->data[ aho->trie + 1 ]);
2413 const char *last_start = strend - trie->minlen;
2415 const char *real_start = s;
2417 STRLEN maxlen = trie->maxlen;
2419 U8 **points; /* map of where we were in the input string
2420 when reading a given char. For ASCII this
2421 is unnecessary overhead as the relationship
2422 is always 1:1, but for Unicode, especially
2423 case folded Unicode this is not true. */
2424 U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
2428 GET_RE_DEBUG_FLAGS_DECL;
2430 /* We can't just allocate points here. We need to wrap it in
2431 * an SV so it gets freed properly if there is a croak while
2432 * running the match */
2435 sv_points=newSV(maxlen * sizeof(U8 *));
2436 SvCUR_set(sv_points,
2437 maxlen * sizeof(U8 *));
2438 SvPOK_on(sv_points);
2439 sv_2mortal(sv_points);
2440 points=(U8**)SvPV_nolen(sv_points );
2441 if ( trie_type != trie_utf8_fold
2442 && (trie->bitmap || OP(c)==AHOCORASICKC) )
2445 bitmap=(U8*)trie->bitmap;
2447 bitmap=(U8*)ANYOF_BITMAP(c);
2449 /* this is the Aho-Corasick algorithm modified a touch
2450 to include special handling for long "unknown char" sequences.
2451 The basic idea being that we use AC as long as we are dealing
2452 with a possible matching char, when we encounter an unknown char
2453 (and we have not encountered an accepting state) we scan forward
2454 until we find a legal starting char.
2455 AC matching is basically that of trie matching, except that when
2456 we encounter a failing transition, we fall back to the current
2457 states "fail state", and try the current char again, a process
2458 we repeat until we reach the root state, state 1, or a legal
2459 transition. If we fail on the root state then we can either
2460 terminate if we have reached an accepting state previously, or
2461 restart the entire process from the beginning if we have not.
2464 while (s <= last_start) {
2465 const U32 uniflags = UTF8_ALLOW_DEFAULT;
2473 U8 *uscan = (U8*)NULL;
2474 U8 *leftmost = NULL;
2476 U32 accepted_word= 0;
2480 while ( state && uc <= (U8*)strend ) {
2482 U32 word = aho->states[ state ].wordnum;
2486 DEBUG_TRIE_EXECUTE_r(
2487 if ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
2488 dump_exec_pos( (char *)uc, c, strend, real_start,
2489 (char *)uc, utf8_target );
2490 PerlIO_printf( Perl_debug_log,
2491 " Scanning for legal start char...\n");
2495 while ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
2499 while ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
2505 if (uc >(U8*)last_start) break;
2509 U8 *lpos= points[ (pointpos - trie->wordinfo[word].len) % maxlen ];
2510 if (!leftmost || lpos < leftmost) {
2511 DEBUG_r(accepted_word=word);
2517 points[pointpos++ % maxlen]= uc;
2518 if (foldlen || uc < (U8*)strend) {
2519 REXEC_TRIE_READ_CHAR(trie_type, trie,
2521 uscan, len, uvc, charid, foldlen,
2523 DEBUG_TRIE_EXECUTE_r({
2524 dump_exec_pos( (char *)uc, c, strend,
2525 real_start, s, utf8_target);
2526 PerlIO_printf(Perl_debug_log,
2527 " Charid:%3u CP:%4"UVxf" ",
2539 word = aho->states[ state ].wordnum;
2541 base = aho->states[ state ].trans.base;
2543 DEBUG_TRIE_EXECUTE_r({
2545 dump_exec_pos( (char *)uc, c, strend, real_start,
2547 PerlIO_printf( Perl_debug_log,
2548 "%sState: %4"UVxf", word=%"UVxf,
2549 failed ? " Fail transition to " : "",
2550 (UV)state, (UV)word);
2556 ( ((offset = base + charid
2557 - 1 - trie->uniquecharcount)) >= 0)
2558 && ((U32)offset < trie->lasttrans)
2559 && trie->trans[offset].check == state
2560 && (tmp=trie->trans[offset].next))
2562 DEBUG_TRIE_EXECUTE_r(
2563 PerlIO_printf( Perl_debug_log," - legal\n"));
2568 DEBUG_TRIE_EXECUTE_r(
2569 PerlIO_printf( Perl_debug_log," - fail\n"));
2571 state = aho->fail[state];
2575 /* we must be accepting here */
2576 DEBUG_TRIE_EXECUTE_r(
2577 PerlIO_printf( Perl_debug_log," - accepting\n"));
2586 if (!state) state = 1;
2589 if ( aho->states[ state ].wordnum ) {
2590 U8 *lpos = points[ (pointpos - trie->wordinfo[aho->states[ state ].wordnum].len) % maxlen ];
2591 if (!leftmost || lpos < leftmost) {
2592 DEBUG_r(accepted_word=aho->states[ state ].wordnum);
2597 s = (char*)leftmost;
2598 DEBUG_TRIE_EXECUTE_r({
2600 Perl_debug_log,"Matches word #%"UVxf" at position %"IVdf". Trying full pattern...\n",
2601 (UV)accepted_word, (IV)(s - real_start)
2604 if (reginfo->intuit || regtry(reginfo, &s)) {
2610 DEBUG_TRIE_EXECUTE_r({
2611 PerlIO_printf( Perl_debug_log,"Pattern failed. Looking for new start point...\n");
2614 DEBUG_TRIE_EXECUTE_r(
2615 PerlIO_printf( Perl_debug_log,"No match.\n"));
2624 Perl_croak(aTHX_ "panic: unknown regstclass %d", (int)OP(c));
2631 /* set RX_SAVED_COPY, RX_SUBBEG etc.
2632 * flags have same meanings as with regexec_flags() */
2635 S_reg_set_capture_string(pTHX_ REGEXP * const rx,
2642 struct regexp *const prog = ReANY(rx);
2644 if (flags & REXEC_COPY_STR) {
2648 PerlIO_printf(Perl_debug_log,
2649 "Copy on write: regexp capture, type %d\n",
2652 /* Create a new COW SV to share the match string and store
2653 * in saved_copy, unless the current COW SV in saved_copy
2654 * is valid and suitable for our purpose */
2655 if (( prog->saved_copy
2656 && SvIsCOW(prog->saved_copy)
2657 && SvPOKp(prog->saved_copy)
2660 && SvPVX(sv) == SvPVX(prog->saved_copy)))
2662 /* just reuse saved_copy SV */
2663 if (RXp_MATCH_COPIED(prog)) {
2664 Safefree(prog->subbeg);
2665 RXp_MATCH_COPIED_off(prog);
2669 /* create new COW SV to share string */
2670 RX_MATCH_COPY_FREE(rx);
2671 prog->saved_copy = sv_setsv_cow(prog->saved_copy, sv);
2673 prog->subbeg = (char *)SvPVX_const(prog->saved_copy);
2674 assert (SvPOKp(prog->saved_copy));
2675 prog->sublen = strend - strbeg;
2676 prog->suboffset = 0;
2677 prog->subcoffset = 0;
2682 SSize_t max = strend - strbeg;
2685 if ( (flags & REXEC_COPY_SKIP_POST)
2686 && !(prog->extflags & RXf_PMf_KEEPCOPY) /* //p */
2687 && !(PL_sawampersand & SAWAMPERSAND_RIGHT)
2688 ) { /* don't copy $' part of string */
2691 /* calculate the right-most part of the string covered
2692 * by a capture. Due to look-ahead, this may be to
2693 * the right of $&, so we have to scan all captures */
2694 while (n <= prog->lastparen) {
2695 if (prog->offs[n].end > max)
2696 max = prog->offs[n].end;
2700 max = (PL_sawampersand & SAWAMPERSAND_LEFT)
2701 ? prog->offs[0].start
2703 assert(max >= 0 && max <= strend - strbeg);
2706 if ( (flags & REXEC_COPY_SKIP_PRE)
2707 && !(prog->extflags & RXf_PMf_KEEPCOPY) /* //p */
2708 && !(PL_sawampersand & SAWAMPERSAND_LEFT)
2709 ) { /* don't copy $` part of string */
2712 /* calculate the left-most part of the string covered
2713 * by a capture. Due to look-behind, this may be to
2714 * the left of $&, so we have to scan all captures */
2715 while (min && n <= prog->lastparen) {
2716 if ( prog->offs[n].start != -1
2717 && prog->offs[n].start < min)
2719 min = prog->offs[n].start;
2723 if ((PL_sawampersand & SAWAMPERSAND_RIGHT)
2724 && min > prog->offs[0].end
2726 min = prog->offs[0].end;
2730 assert(min >= 0 && min <= max && min <= strend - strbeg);
2733 if (RX_MATCH_COPIED(rx)) {
2734 if (sublen > prog->sublen)
2736 (char*)saferealloc(prog->subbeg, sublen+1);
2739 prog->subbeg = (char*)safemalloc(sublen+1);
2740 Copy(strbeg + min, prog->subbeg, sublen, char);
2741 prog->subbeg[sublen] = '\0';
2742 prog->suboffset = min;
2743 prog->sublen = sublen;
2744 RX_MATCH_COPIED_on(rx);
2746 prog->subcoffset = prog->suboffset;
2747 if (prog->suboffset && utf8_target) {
2748 /* Convert byte offset to chars.
2749 * XXX ideally should only compute this if @-/@+
2750 * has been seen, a la PL_sawampersand ??? */
2752 /* If there's a direct correspondence between the
2753 * string which we're matching and the original SV,
2754 * then we can use the utf8 len cache associated with
2755 * the SV. In particular, it means that under //g,
2756 * sv_pos_b2u() will use the previously cached
2757 * position to speed up working out the new length of
2758 * subcoffset, rather than counting from the start of
2759 * the string each time. This stops
2760 * $x = "\x{100}" x 1E6; 1 while $x =~ /(.)/g;
2761 * from going quadratic */
2762 if (SvPOKp(sv) && SvPVX(sv) == strbeg)
2763 prog->subcoffset = sv_pos_b2u_flags(sv, prog->subcoffset,
2764 SV_GMAGIC|SV_CONST_RETURN);
2766 prog->subcoffset = utf8_length((U8*)strbeg,
2767 (U8*)(strbeg+prog->suboffset));
2771 RX_MATCH_COPY_FREE(rx);
2772 prog->subbeg = strbeg;
2773 prog->suboffset = 0;
2774 prog->subcoffset = 0;
2775 prog->sublen = strend - strbeg;
2783 - regexec_flags - match a regexp against a string
2786 Perl_regexec_flags(pTHX_ REGEXP * const rx, char *stringarg, char *strend,
2787 char *strbeg, SSize_t minend, SV *sv, void *data, U32 flags)
2788 /* stringarg: the point in the string at which to begin matching */
2789 /* strend: pointer to null at end of string */
2790 /* strbeg: real beginning of string */
2791 /* minend: end of match must be >= minend bytes after stringarg. */
2792 /* sv: SV being matched: only used for utf8 flag, pos() etc; string
2793 * itself is accessed via the pointers above */
2794 /* data: May be used for some additional optimizations.
2795 Currently unused. */
2796 /* flags: For optimizations. See REXEC_* in regexp.h */
2799 struct regexp *const prog = ReANY(rx);
2803 SSize_t minlen; /* must match at least this many chars */
2804 SSize_t dontbother = 0; /* how many characters not to try at end */
2805 const bool utf8_target = cBOOL(DO_UTF8(sv));
2807 RXi_GET_DECL(prog,progi);
2808 regmatch_info reginfo_buf; /* create some info to pass to regtry etc */
2809 regmatch_info *const reginfo = ®info_buf;
2810 regexp_paren_pair *swap = NULL;
2812 GET_RE_DEBUG_FLAGS_DECL;
2814 PERL_ARGS_ASSERT_REGEXEC_FLAGS;
2815 PERL_UNUSED_ARG(data);
2817 /* Be paranoid... */
2819 Perl_croak(aTHX_ "NULL regexp parameter");
2823 debug_start_match(rx, utf8_target, stringarg, strend,
2827 startpos = stringarg;
2829 if (prog->intflags & PREGf_GPOS_SEEN) {
2832 /* set reginfo->ganch, the position where \G can match */
2835 (flags & REXEC_IGNOREPOS)
2836 ? stringarg /* use start pos rather than pos() */
2837 : ((mg = mg_find_mglob(sv)) && mg->mg_len >= 0)
2838 /* Defined pos(): */
2839 ? strbeg + MgBYTEPOS(mg, sv, strbeg, strend-strbeg)
2840 : strbeg; /* pos() not defined; use start of string */
2842 DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
2843 "GPOS ganch set to strbeg[%"IVdf"]\n", (IV)(reginfo->ganch - strbeg)));
2845 /* in the presence of \G, we may need to start looking earlier in
2846 * the string than the suggested start point of stringarg:
2847 * if prog->gofs is set, then that's a known, fixed minimum
2850 * /ab|c\G/: gofs = 1
2851 * or if the minimum offset isn't known, then we have to go back
2852 * to the start of the string, e.g. /w+\G/
2855 if (prog->intflags & PREGf_ANCH_GPOS) {
2856 startpos = reginfo->ganch - prog->gofs;
2858 ((flags & REXEC_FAIL_ON_UNDERFLOW) ? stringarg : strbeg))
2860 DEBUG_r(PerlIO_printf(Perl_debug_log,
2861 "fail: ganch-gofs before earliest possible start\n"));
2865 else if (prog->gofs) {
2866 if (startpos - prog->gofs < strbeg)
2869 startpos -= prog->gofs;
2871 else if (prog->intflags & PREGf_GPOS_FLOAT)
2875 minlen = prog->minlen;
2876 if ((startpos + minlen) > strend || startpos < strbeg) {
2877 DEBUG_r(PerlIO_printf(Perl_debug_log,
2878 "Regex match can't succeed, so not even tried\n"));
2882 /* at the end of this function, we'll do a LEAVE_SCOPE(oldsave),
2883 * which will call destuctors to reset PL_regmatch_state, free higher
2884 * PL_regmatch_slabs, and clean up regmatch_info_aux and
2885 * regmatch_info_aux_eval */
2887 oldsave = PL_savestack_ix;
2891 if ((prog->extflags & RXf_USE_INTUIT)
2892 && !(flags & REXEC_CHECKED))
2894 s = re_intuit_start(rx, sv, strbeg, startpos, strend,
2899 if (prog->extflags & RXf_CHECK_ALL) {
2900 /* we can match based purely on the result of INTUIT.
2901 * Set up captures etc just for $& and $-[0]
2902 * (an intuit-only match wont have $1,$2,..) */
2903 assert(!prog->nparens);
2905 /* s/// doesn't like it if $& is earlier than where we asked it to
2906 * start searching (which can happen on something like /.\G/) */
2907 if ( (flags & REXEC_FAIL_ON_UNDERFLOW)
2910 /* this should only be possible under \G */
2911 assert(prog->intflags & PREGf_GPOS_SEEN);
2912 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
2913 "matched, but failing for REXEC_FAIL_ON_UNDERFLOW\n"));
2917 /* match via INTUIT shouldn't have any captures.
2918 * Let @-, @+, $^N know */
2919 prog->lastparen = prog->lastcloseparen = 0;
2920 RX_MATCH_UTF8_set(rx, utf8_target);
2921 prog->offs[0].start = s - strbeg;
2922 prog->offs[0].end = utf8_target
2923 ? (char*)utf8_hop((U8*)s, prog->minlenret) - strbeg
2924 : s - strbeg + prog->minlenret;
2925 if ( !(flags & REXEC_NOT_FIRST) )
2926 S_reg_set_capture_string(aTHX_ rx,
2928 sv, flags, utf8_target);
2934 multiline = prog->extflags & RXf_PMf_MULTILINE;
2936 if (strend - s < (minlen+(prog->check_offset_min<0?prog->check_offset_min:0))) {
2937 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
2938 "String too short [regexec_flags]...\n"));
2942 /* Check validity of program. */
2943 if (UCHARAT(progi->program) != REG_MAGIC) {
2944 Perl_croak(aTHX_ "corrupted regexp program");
2947 RX_MATCH_TAINTED_off(rx);
2948 RX_MATCH_UTF8_set(rx, utf8_target);
2950 reginfo->prog = rx; /* Yes, sorry that this is confusing. */
2951 reginfo->intuit = 0;
2952 reginfo->is_utf8_target = cBOOL(utf8_target);
2953 reginfo->is_utf8_pat = cBOOL(RX_UTF8(rx));
2954 reginfo->warned = FALSE;
2955 reginfo->strbeg = strbeg;
2957 reginfo->poscache_maxiter = 0; /* not yet started a countdown */
2958 reginfo->strend = strend;
2959 /* see how far we have to get to not match where we matched before */
2960 reginfo->till = stringarg + minend;
2962 if (prog->extflags & RXf_EVAL_SEEN && SvPADTMP(sv)) {
2963 /* SAVEFREESV, not sv_mortalcopy, as this SV must last until after
2964 S_cleanup_regmatch_info_aux has executed (registered by
2965 SAVEDESTRUCTOR_X below). S_cleanup_regmatch_info_aux modifies
2966 magic belonging to this SV.
2967 Not newSVsv, either, as it does not COW.
2969 reginfo->sv = newSV(0);
2970 SvSetSV_nosteal(reginfo->sv, sv);
2971 SAVEFREESV(reginfo->sv);
2974 /* reserve next 2 or 3 slots in PL_regmatch_state:
2975 * slot N+0: may currently be in use: skip it
2976 * slot N+1: use for regmatch_info_aux struct
2977 * slot N+2: use for regmatch_info_aux_eval struct if we have (?{})'s
2978 * slot N+3: ready for use by regmatch()
2982 regmatch_state *old_regmatch_state;
2983 regmatch_slab *old_regmatch_slab;
2984 int i, max = (prog->extflags & RXf_EVAL_SEEN) ? 2 : 1;
2986 /* on first ever match, allocate first slab */
2987 if (!PL_regmatch_slab) {
2988 Newx(PL_regmatch_slab, 1, regmatch_slab);
2989 PL_regmatch_slab->prev = NULL;
2990 PL_regmatch_slab->next = NULL;
2991 PL_regmatch_state = SLAB_FIRST(PL_regmatch_slab);
2994 old_regmatch_state = PL_regmatch_state;
2995 old_regmatch_slab = PL_regmatch_slab;
2997 for (i=0; i <= max; i++) {
2999 reginfo->info_aux = &(PL_regmatch_state->u.info_aux);
3001 reginfo->info_aux_eval =
3002 reginfo->info_aux->info_aux_eval =
3003 &(PL_regmatch_state->u.info_aux_eval);
3005 if (++PL_regmatch_state > SLAB_LAST(PL_regmatch_slab))
3006 PL_regmatch_state = S_push_slab(aTHX);
3009 /* note initial PL_regmatch_state position; at end of match we'll
3010 * pop back to there and free any higher slabs */
3012 reginfo->info_aux->old_regmatch_state = old_regmatch_state;
3013 reginfo->info_aux->old_regmatch_slab = old_regmatch_slab;
3014 reginfo->info_aux->poscache = NULL;
3016 SAVEDESTRUCTOR_X(S_cleanup_regmatch_info_aux, reginfo->info_aux);
3018 if ((prog->extflags & RXf_EVAL_SEEN))
3019 S_setup_eval_state(aTHX_ reginfo);
3021 reginfo->info_aux_eval = reginfo->info_aux->info_aux_eval = NULL;
3024 /* If there is a "must appear" string, look for it. */
3026 if (PL_curpm && (PM_GETRE(PL_curpm) == rx)) {
3027 /* We have to be careful. If the previous successful match
3028 was from this regex we don't want a subsequent partially
3029 successful match to clobber the old results.
3030 So when we detect this possibility we add a swap buffer
3031 to the re, and switch the buffer each match. If we fail,
3032 we switch it back; otherwise we leave it swapped.
3035 /* do we need a save destructor here for eval dies? */
3036 Newxz(prog->offs, (prog->nparens + 1), regexp_paren_pair);
3037 DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
3038 "rex=0x%"UVxf" saving offs: orig=0x%"UVxf" new=0x%"UVxf"\n",
3045 /* Simplest case: anchored match need be tried only once, or with
3046 * MBOL, only at the beginning of each line.
3048 * Note that /.*.../ sets PREGf_IMPLICIT|MBOL, while /.*.../s sets
3049 * PREGf_IMPLICIT|SBOL. The idea is that with /.*.../s, if it doesn't
3050 * match at the start of the string then it won't match anywhere else
3051 * either; while with /.*.../, if it doesn't match at the beginning,
3052 * the earliest it could match is at the start of the next line */
3054 if (prog->intflags & (PREGf_ANCH & ~PREGf_ANCH_GPOS)) {
3057 if (regtry(reginfo, &s))
3060 if (!(prog->intflags & PREGf_ANCH_MBOL))
3063 /* didn't match at start, try at other newline positions */
3066 dontbother = minlen - 1;
3067 end = HOP3c(strend, -dontbother, strbeg) - 1;
3069 /* skip to next newline */
3071 while (s <= end) { /* note it could be possible to match at the end of the string */
3072 /* NB: newlines are the same in unicode as they are in latin */
3075 if (prog->check_substr || prog->check_utf8) {
3076 /* note that with PREGf_IMPLICIT, intuit can only fail
3077 * or return the start position, so it's of limited utility.
3078 * Nevertheless, I made the decision that the potential for
3079 * quick fail was still worth it - DAPM */
3080 s = re_intuit_start(rx, sv, strbeg, s, strend, flags, NULL);
3084 if (regtry(reginfo, &s))
3088 } /* end anchored search */
3090 if (prog->intflags & PREGf_ANCH_GPOS)
3092 /* PREGf_ANCH_GPOS should never be true if PREGf_GPOS_SEEN is not true */
3093 assert(prog->intflags & PREGf_GPOS_SEEN);
3094 /* For anchored \G, the only position it can match from is
3095 * (ganch-gofs); we already set startpos to this above; if intuit
3096 * moved us on from there, we can't possibly succeed */
3097 assert(startpos == reginfo->ganch - prog->gofs);
3098 if (s == startpos && regtry(reginfo, &s))
3103 /* Messy cases: unanchored match. */
3104 if ((prog->anchored_substr || prog->anchored_utf8) && prog->intflags & PREGf_SKIP) {
3105 /* we have /x+whatever/ */
3106 /* it must be a one character string (XXXX Except is_utf8_pat?) */
3112 if (! prog->anchored_utf8) {
3113 to_utf8_substr(prog);
3115 ch = SvPVX_const(prog->anchored_utf8)[0];
3118 DEBUG_EXECUTE_r( did_match = 1 );
3119 if (regtry(reginfo, &s)) goto got_it;
3121 while (s < strend && *s == ch)
3128 if (! prog->anchored_substr) {
3129 if (! to_byte_substr(prog)) {
3130 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3133 ch = SvPVX_const(prog->anchored_substr)[0];
3136 DEBUG_EXECUTE_r( did_match = 1 );
3137 if (regtry(reginfo, &s)) goto got_it;
3139 while (s < strend && *s == ch)
3144 DEBUG_EXECUTE_r(if (!did_match)
3145 PerlIO_printf(Perl_debug_log,
3146 "Did not find anchored character...\n")
3149 else if (prog->anchored_substr != NULL
3150 || prog->anchored_utf8 != NULL
3151 || ((prog->float_substr != NULL || prog->float_utf8 != NULL)
3152 && prog->float_max_offset < strend - s)) {
3157 char *last1; /* Last position checked before */
3161 if (prog->anchored_substr || prog->anchored_utf8) {
3163 if (! prog->anchored_utf8) {
3164 to_utf8_substr(prog);
3166 must = prog->anchored_utf8;
3169 if (! prog->anchored_substr) {
3170 if (! to_byte_substr(prog)) {
3171 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3174 must = prog->anchored_substr;
3176 back_max = back_min = prog->anchored_offset;
3179 if (! prog->float_utf8) {
3180 to_utf8_substr(prog);
3182 must = prog->float_utf8;
3185 if (! prog->float_substr) {
3186 if (! to_byte_substr(prog)) {
3187 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3190 must = prog->float_substr;
3192 back_max = prog->float_max_offset;
3193 back_min = prog->float_min_offset;
3199 last = HOP3c(strend, /* Cannot start after this */
3200 -(SSize_t)(CHR_SVLEN(must)
3201 - (SvTAIL(must) != 0) + back_min), strbeg);
3203 if (s > reginfo->strbeg)
3204 last1 = HOPc(s, -1);
3206 last1 = s - 1; /* bogus */
3208 /* XXXX check_substr already used to find "s", can optimize if
3209 check_substr==must. */
3211 strend = HOPc(strend, -dontbother);
3212 while ( (s <= last) &&
3213 (s = fbm_instr((unsigned char*)HOP4c(s, back_min, strbeg, strend),
3214 (unsigned char*)strend, must,
3215 multiline ? FBMrf_MULTILINE : 0)) ) {
3216 DEBUG_EXECUTE_r( did_match = 1 );
3217 if (HOPc(s, -back_max) > last1) {
3218 last1 = HOPc(s, -back_min);
3219 s = HOPc(s, -back_max);
3222 char * const t = (last1 >= reginfo->strbeg)
3223 ? HOPc(last1, 1) : last1 + 1;
3225 last1 = HOPc(s, -back_min);
3229 while (s <= last1) {
3230 if (regtry(reginfo, &s))
3233 s++; /* to break out of outer loop */
3240 while (s <= last1) {
3241 if (regtry(reginfo, &s))
3247 DEBUG_EXECUTE_r(if (!did_match) {
3248 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
3249 SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
3250 PerlIO_printf(Perl_debug_log, "Did not find %s substr %s%s...\n",
3251 ((must == prog->anchored_substr || must == prog->anchored_utf8)
3252 ? "anchored" : "floating"),
3253 quoted, RE_SV_TAIL(must));
3257 else if ( (c = progi->regstclass) ) {
3259 const OPCODE op = OP(progi->regstclass);
3260 /* don't bother with what can't match */
3261 if (PL_regkind[op] != EXACT && PL_regkind[op] != TRIE)
3262 strend = HOPc(strend, -(minlen - 1));
3265 SV * const prop = sv_newmortal();
3266 regprop(prog, prop, c, reginfo, NULL);
3268 RE_PV_QUOTED_DECL(quoted,utf8_target,PERL_DEBUG_PAD_ZERO(1),
3270 PerlIO_printf(Perl_debug_log,
3271 "Matching stclass %.*s against %s (%d bytes)\n",
3272 (int)SvCUR(prop), SvPVX_const(prop),
3273 quoted, (int)(strend - s));
3276 if (find_byclass(prog, c, s, strend, reginfo))
3278 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Contradicts stclass... [regexec_flags]\n"));
3282 if (prog->float_substr != NULL || prog->float_utf8 != NULL) {
3290 if (! prog->float_utf8) {
3291 to_utf8_substr(prog);
3293 float_real = prog->float_utf8;
3296 if (! prog->float_substr) {
3297 if (! to_byte_substr(prog)) {
3298 NON_UTF8_TARGET_BUT_UTF8_REQUIRED(phooey);
3301 float_real = prog->float_substr;
3304 little = SvPV_const(float_real, len);
3305 if (SvTAIL(float_real)) {
3306 /* This means that float_real contains an artificial \n on
3307 * the end due to the presence of something like this:
3308 * /foo$/ where we can match both "foo" and "foo\n" at the
3309 * end of the string. So we have to compare the end of the
3310 * string first against the float_real without the \n and
3311 * then against the full float_real with the string. We
3312 * have to watch out for cases where the string might be
3313 * smaller than the float_real or the float_real without
3315 char *checkpos= strend - len;
3317 PerlIO_printf(Perl_debug_log,
3318 "%sChecking for float_real.%s\n",
3319 PL_colors[4], PL_colors[5]));
3320 if (checkpos + 1 < strbeg) {
3321 /* can't match, even if we remove the trailing \n
3322 * string is too short to match */
3324 PerlIO_printf(Perl_debug_log,
3325 "%sString shorter than required trailing substring, cannot match.%s\n",
3326 PL_colors[4], PL_colors[5]));
3328 } else if (memEQ(checkpos + 1, little, len - 1)) {
3329 /* can match, the end of the string matches without the
3331 last = checkpos + 1;
3332 } else if (checkpos < strbeg) {
3333 /* cant match, string is too short when the "\n" is
3336 PerlIO_printf(Perl_debug_log,
3337 "%sString does not contain required trailing substring, cannot match.%s\n",
3338 PL_colors[4], PL_colors[5]));
3340 } else if (!multiline) {
3341 /* non multiline match, so compare with the "\n" at the
3342 * end of the string */
3343 if (memEQ(checkpos, little, len)) {
3347 PerlIO_printf(Perl_debug_log,
3348 "%sString does not contain required trailing substring, cannot match.%s\n",
3349 PL_colors[4], PL_colors[5]));
3353 /* multiline match, so we have to search for a place
3354 * where the full string is located */
3360 last = rninstr(s, strend, little, little + len);
3362 last = strend; /* matching "$" */
3365 /* at one point this block contained a comment which was
3366 * probably incorrect, which said that this was a "should not
3367 * happen" case. Even if it was true when it was written I am
3368 * pretty sure it is not anymore, so I have removed the comment
3369 * and replaced it with this one. Yves */
3371 PerlIO_printf(Perl_debug_log,
3372 "%sString does not contain required substring, cannot match.%s\n",
3373 PL_colors[4], PL_colors[5]
3377 dontbother = strend - last + prog->float_min_offset;
3379 if (minlen && (dontbother < minlen))
3380 dontbother = minlen - 1;
3381 strend -= dontbother; /* this one's always in bytes! */
3382 /* We don't know much -- general case. */
3385 if (regtry(reginfo, &s))
3394 if (regtry(reginfo, &s))
3396 } while (s++ < strend);
3404 /* s/// doesn't like it if $& is earlier than where we asked it to
3405 * start searching (which can happen on something like /.\G/) */
3406 if ( (flags & REXEC_FAIL_ON_UNDERFLOW)
3407 && (prog->offs[0].start < stringarg - strbeg))
3409 /* this should only be possible under \G */
3410 assert(prog->intflags & PREGf_GPOS_SEEN);
3411 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
3412 "matched, but failing for REXEC_FAIL_ON_UNDERFLOW\n"));
3418 PerlIO_printf(Perl_debug_log,
3419 "rex=0x%"UVxf" freeing offs: 0x%"UVxf"\n",
3426 /* clean up; this will trigger destructors that will free all slabs
3427 * above the current one, and cleanup the regmatch_info_aux
3428 * and regmatch_info_aux_eval sructs */
3430 LEAVE_SCOPE(oldsave);
3432 if (RXp_PAREN_NAMES(prog))
3433 (void)hv_iterinit(RXp_PAREN_NAMES(prog));
3435 /* make sure $`, $&, $', and $digit will work later */
3436 if ( !(flags & REXEC_NOT_FIRST) )
3437 S_reg_set_capture_string(aTHX_ rx,
3438 strbeg, reginfo->strend,
3439 sv, flags, utf8_target);
3444 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch failed%s\n",
3445 PL_colors[4], PL_colors[5]));
3447 /* clean up; this will trigger destructors that will free all slabs
3448 * above the current one, and cleanup the regmatch_info_aux
3449 * and regmatch_info_aux_eval sructs */
3451 LEAVE_SCOPE(oldsave);
3454 /* we failed :-( roll it back */
3455 DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
3456 "rex=0x%"UVxf" rolling back offs: freeing=0x%"UVxf" restoring=0x%"UVxf"\n",
3461 Safefree(prog->offs);
3468 /* Set which rex is pointed to by PL_reg_curpm, handling ref counting.
3469 * Do inc before dec, in case old and new rex are the same */
3470 #define SET_reg_curpm(Re2) \
3471 if (reginfo->info_aux_eval) { \
3472 (void)ReREFCNT_inc(Re2); \
3473 ReREFCNT_dec(PM_GETRE(PL_reg_curpm)); \
3474 PM_SETRE((PL_reg_curpm), (Re2)); \
3479 - regtry - try match at specific point
3481 STATIC I32 /* 0 failure, 1 success */
3482 S_regtry(pTHX_ regmatch_info *reginfo, char **startposp)
3485 REGEXP *const rx = reginfo->prog;
3486 regexp *const prog = ReANY(rx);
3488 RXi_GET_DECL(prog,progi);
3489 GET_RE_DEBUG_FLAGS_DECL;
3491 PERL_ARGS_ASSERT_REGTRY;
3493 reginfo->cutpoint=NULL;
3495 prog->offs[0].start = *startposp - reginfo->strbeg;
3496 prog->lastparen = 0;
3497 prog->lastcloseparen = 0;
3499 /* XXXX What this code is doing here?!!! There should be no need
3500 to do this again and again, prog->lastparen should take care of
3503 /* Tests pat.t#187 and split.t#{13,14} seem to depend on this code.
3504 * Actually, the code in regcppop() (which Ilya may be meaning by
3505 * prog->lastparen), is not needed at all by the test suite
3506 * (op/regexp, op/pat, op/split), but that code is needed otherwise
3507 * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
3508 * Meanwhile, this code *is* needed for the
3509 * above-mentioned test suite tests to succeed. The common theme
3510 * on those tests seems to be returning null fields from matches.
3511 * --jhi updated by dapm */
3513 if (prog->nparens) {
3514 regexp_paren_pair *pp = prog->offs;
3516 for (i = prog->nparens; i > (I32)prog->lastparen; i--) {
3524 result = regmatch(reginfo, *startposp, progi->program + 1);
3526 prog->offs[0].end = result;
3529 if (reginfo->cutpoint)
3530 *startposp= reginfo->cutpoint;
3531 REGCP_UNWIND(lastcp);
3536 #define sayYES goto yes
3537 #define sayNO goto no
3538 #define sayNO_SILENT goto no_silent
3540 /* we dont use STMT_START/END here because it leads to
3541 "unreachable code" warnings, which are bogus, but distracting. */
3542 #define CACHEsayNO \
3543 if (ST.cache_mask) \
3544 reginfo->info_aux->poscache[ST.cache_offset] |= ST.cache_mask; \
3547 /* this is used to determine how far from the left messages like
3548 'failed...' are printed. It should be set such that messages
3549 are inline with the regop output that created them.
3551 #define REPORT_CODE_OFF 32
3554 #define CHRTEST_UNINIT -1001 /* c1/c2 haven't been calculated yet */
3555 #define CHRTEST_VOID -1000 /* the c1/c2 "next char" test should be skipped */
3556 #define CHRTEST_NOT_A_CP_1 -999
3557 #define CHRTEST_NOT_A_CP_2 -998
3559 /* grab a new slab and return the first slot in it */
3561 STATIC regmatch_state *
3564 #if PERL_VERSION < 9 && !defined(PERL_CORE)
3567 regmatch_slab *s = PL_regmatch_slab->next;
3569 Newx(s, 1, regmatch_slab);
3570 s->prev = PL_regmatch_slab;
3572 PL_regmatch_slab->next = s;
3574 PL_regmatch_slab = s;
3575 return SLAB_FIRST(s);
3579 /* push a new state then goto it */
3581 #define PUSH_STATE_GOTO(state, node, input) \
3582 pushinput = input; \
3584 st->resume_state = state; \
3587 /* push a new state with success backtracking, then goto it */
3589 #define PUSH_YES_STATE_GOTO(state, node, input) \
3590 pushinput = input; \
3592 st->resume_state = state; \
3593 goto push_yes_state;
3600 regmatch() - main matching routine
3602 This is basically one big switch statement in a loop. We execute an op,
3603 set 'next' to point the next op, and continue. If we come to a point which
3604 we may need to backtrack to on failure such as (A|B|C), we push a
3605 backtrack state onto the backtrack stack. On failure, we pop the top
3606 state, and re-enter the loop at the state indicated. If there are no more
3607 states to pop, we return failure.
3609 Sometimes we also need to backtrack on success; for example /A+/, where
3610 after successfully matching one A, we need to go back and try to
3611 match another one; similarly for lookahead assertions: if the assertion
3612 completes successfully, we backtrack to the state just before the assertion
3613 and then carry on. In these cases, the pushed state is marked as
3614 'backtrack on success too'. This marking is in fact done by a chain of
3615 pointers, each pointing to the previous 'yes' state. On success, we pop to
3616 the nearest yes state, discarding any intermediate failure-only states.
3617 Sometimes a yes state is pushed just to force some cleanup code to be
3618 called at the end of a successful match or submatch; e.g. (??{$re}) uses
3619 it to free the inner regex.
3621 Note that failure backtracking rewinds the cursor position, while
3622 success backtracking leaves it alone.
3624 A pattern is complete when the END op is executed, while a subpattern
3625 such as (?=foo) is complete when the SUCCESS op is executed. Both of these
3626 ops trigger the "pop to last yes state if any, otherwise return true"
3629 A common convention in this function is to use A and B to refer to the two
3630 subpatterns (or to the first nodes thereof) in patterns like /A*B/: so A is
3631 the subpattern to be matched possibly multiple times, while B is the entire
3632 rest of the pattern. Variable and state names reflect this convention.
3634 The states in the main switch are the union of ops and failure/success of
3635 substates associated with with that op. For example, IFMATCH is the op
3636 that does lookahead assertions /(?=A)B/ and so the IFMATCH state means
3637 'execute IFMATCH'; while IFMATCH_A is a state saying that we have just
3638 successfully matched A and IFMATCH_A_fail is a state saying that we have
3639 just failed to match A. Resume states always come in pairs. The backtrack
3640 state we push is marked as 'IFMATCH_A', but when that is popped, we resume
3641 at IFMATCH_A or IFMATCH_A_fail, depending on whether we are backtracking
3642 on success or failure.
3644 The struct that holds a backtracking state is actually a big union, with
3645 one variant for each major type of op. The variable st points to the
3646 top-most backtrack struct. To make the code clearer, within each
3647 block of code we #define ST to alias the relevant union.
3649 Here's a concrete example of a (vastly oversimplified) IFMATCH
3655 #define ST st->u.ifmatch
3657 case IFMATCH: // we are executing the IFMATCH op, (?=A)B
3658 ST.foo = ...; // some state we wish to save
3660 // push a yes backtrack state with a resume value of
3661 // IFMATCH_A/IFMATCH_A_fail, then continue execution at the
3663 PUSH_YES_STATE_GOTO(IFMATCH_A, A, newinput);
3666 case IFMATCH_A: // we have successfully executed A; now continue with B
3668 bar = ST.foo; // do something with the preserved value
3671 case IFMATCH_A_fail: // A failed, so the assertion failed
3672 ...; // do some housekeeping, then ...
3673 sayNO; // propagate the failure
3680 For any old-timers reading this who are familiar with the old recursive
3681 approach, the code above is equivalent to:
3683 case IFMATCH: // we are executing the IFMATCH op, (?=A)B
3692 ...; // do some housekeeping, then ...
3693 sayNO; // propagate the failure
3696 The topmost backtrack state, pointed to by st, is usually free. If you
3697 want to claim it, populate any ST.foo fields in it with values you wish to
3698 save, then do one of
3700 PUSH_STATE_GOTO(resume_state, node, newinput);
3701 PUSH_YES_STATE_GOTO(resume_state, node, newinput);
3703 which sets that backtrack state's resume value to 'resume_state', pushes a
3704 new free entry to the top of the backtrack stack, then goes to 'node'.
3705 On backtracking, the free slot is popped, and the saved state becomes the
3706 new free state. An ST.foo field in this new top state can be temporarily
3707 accessed to retrieve values, but once the main loop is re-entered, it
3708 becomes available for reuse.
3710 Note that the depth of the backtrack stack constantly increases during the
3711 left-to-right execution of the pattern, rather than going up and down with
3712 the pattern nesting. For example the stack is at its maximum at Z at the
3713 end of the pattern, rather than at X in the following:
3715 /(((X)+)+)+....(Y)+....Z/
3717 The only exceptions to this are lookahead/behind assertions and the cut,
3718 (?>A), which pop all the backtrack states associated with A before
3721 Backtrack state structs are allocated in slabs of about 4K in size.
3722 PL_regmatch_state and st always point to the currently active state,
3723 and PL_regmatch_slab points to the slab currently containing
3724 PL_regmatch_state. The first time regmatch() is called, the first slab is
3725 allocated, and is never freed until interpreter destruction. When the slab
3726 is full, a new one is allocated and chained to the end. At exit from
3727 regmatch(), slabs allocated since entry are freed.
3732 #define DEBUG_STATE_pp(pp) \
3734 DUMP_EXEC_POS(locinput, scan, utf8_target); \
3735 PerlIO_printf(Perl_debug_log, \
3736 " %*s"pp" %s%s%s%s%s\n", \
3738 PL_reg_name[st->resume_state], \
3739 ((st==yes_state||st==mark_state) ? "[" : ""), \
3740 ((st==yes_state) ? "Y" : ""), \
3741 ((st==mark_state) ? "M" : ""), \
3742 ((st==yes_state||st==mark_state) ? "]" : "") \
3747 #define REG_NODE_NUM(x) ((x) ? (int)((x)-prog) : -1)
3752 S_debug_start_match(pTHX_ const REGEXP *prog, const bool utf8_target,
3753 const char *start, const char *end, const char *blurb)
3755 const bool utf8_pat = RX_UTF8(prog) ? 1 : 0;
3757 PERL_ARGS_ASSERT_DEBUG_START_MATCH;
3762 RE_PV_QUOTED_DECL(s0, utf8_pat, PERL_DEBUG_PAD_ZERO(0),
3763 RX_PRECOMP_const(prog), RX_PRELEN(prog), 60);
3765 RE_PV_QUOTED_DECL(s1, utf8_target, PERL_DEBUG_PAD_ZERO(1),
3766 start, end - start, 60);
3768 PerlIO_printf(Perl_debug_log,
3769 "%s%s REx%s %s against %s\n",
3770 PL_colors[4], blurb, PL_colors[5], s0, s1);
3772 if (utf8_target||utf8_pat)
3773 PerlIO_printf(Perl_debug_log, "UTF-8 %s%s%s...\n",
3774 utf8_pat ? "pattern" : "",
3775 utf8_pat && utf8_target ? " and " : "",
3776 utf8_target ? "string" : ""
3782 S_dump_exec_pos(pTHX_ const char *locinput,
3783 const regnode *scan,
3784 const char *loc_regeol,
3785 const char *loc_bostr,
3786 const char *loc_reg_starttry,
3787 const bool utf8_target)
3789 const int docolor = *PL_colors[0] || *PL_colors[2] || *PL_colors[4];
3790 const int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */
3791 int l = (loc_regeol - locinput) > taill ? taill : (loc_regeol - locinput);
3792 /* The part of the string before starttry has one color
3793 (pref0_len chars), between starttry and current
3794 position another one (pref_len - pref0_len chars),
3795 after the current position the third one.
3796 We assume that pref0_len <= pref_len, otherwise we
3797 decrease pref0_len. */
3798 int pref_len = (locinput - loc_bostr) > (5 + taill) - l
3799 ? (5 + taill) - l : locinput - loc_bostr;
3802 PERL_ARGS_ASSERT_DUMP_EXEC_POS;
3804 while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput - pref_len)))
3806 pref0_len = pref_len - (locinput - loc_reg_starttry);
3807 if (l + pref_len < (5 + taill) && l < loc_regeol - locinput)
3808 l = ( loc_regeol - locinput > (5 + taill) - pref_len
3809 ? (5 + taill) - pref_len : loc_regeol - locinput);
3810 while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput + l)))
3814 if (pref0_len > pref_len)
3815 pref0_len = pref_len;
3817 const int is_uni = utf8_target ? 1 : 0;
3819 RE_PV_COLOR_DECL(s0,len0,is_uni,PERL_DEBUG_PAD(0),
3820 (locinput - pref_len),pref0_len, 60, 4, 5);
3822 RE_PV_COLOR_DECL(s1,len1,is_uni,PERL_DEBUG_PAD(1),
3823 (locinput - pref_len + pref0_len),
3824 pref_len - pref0_len, 60, 2, 3);
3826 RE_PV_COLOR_DECL(s2,len2,is_uni,PERL_DEBUG_PAD(2),
3827 locinput, loc_regeol - locinput, 10, 0, 1);
3829 const STRLEN tlen=len0+len1+len2;
3830 PerlIO_printf(Perl_debug_log,
3831 "%4"IVdf" <%.*s%.*s%s%.*s>%*s|",
3832 (IV)(locinput - loc_bostr),
3835 (docolor ? "" : "> <"),
3837 (int)(tlen > 19 ? 0 : 19 - tlen),
3844 /* reg_check_named_buff_matched()
3845 * Checks to see if a named buffer has matched. The data array of
3846 * buffer numbers corresponding to the buffer is expected to reside
3847 * in the regexp->data->data array in the slot stored in the ARG() of
3848 * node involved. Note that this routine doesn't actually care about the
3849 * name, that information is not preserved from compilation to execution.
3850 * Returns the index of the leftmost defined buffer with the given name
3851 * or 0 if non of the buffers matched.
3854 S_reg_check_named_buff_matched(const regexp *rex, const regnode *scan)
3857 RXi_GET_DECL(rex,rexi);
3858 SV *sv_dat= MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
3859 I32 *nums=(I32*)SvPVX(sv_dat);
3861 PERL_ARGS_ASSERT_REG_CHECK_NAMED_BUFF_MATCHED;
3863 for ( n=0; n<SvIVX(sv_dat); n++ ) {
3864 if ((I32)rex->lastparen >= nums[n] &&
3865 rex->offs[nums[n]].end != -1)
3875 S_setup_EXACTISH_ST_c1_c2(pTHX_ const regnode * const text_node, int *c1p,
3876 U8* c1_utf8, int *c2p, U8* c2_utf8, regmatch_info *reginfo)
3878 /* This function determines if there are one or two characters that match
3879 * the first character of the passed-in EXACTish node <text_node>, and if
3880 * so, returns them in the passed-in pointers.
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