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a0d0e21e
LW
1/* regexec.c
2 */
3
4/*
4ac71550
TC
5 * One Ring to rule them all, One Ring to find them
6 &
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"]
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LW
10 */
11
61296642
DM
12/* This file contains functions for executing a regular expression. See
13 * also regcomp.c which funnily enough, contains functions for compiling
166f8a29 14 * a regular expression.
e4a054ea
DM
15 *
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.
166f8a29
DM
20 */
21
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LW
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!
24 */
25
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.
29 */
30
e50aee73
AD
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.
34*/
35
b9d5759e 36#ifdef PERL_EXT_RE_BUILD
54df2634 37#include "re_top.h"
9041c2e3 38#endif
56953603 39
a687059c 40/*
e50aee73 41 * pregcomp and pregexec -- regsub and regerror are not used in perl
a687059c
LW
42 *
43 * Copyright (c) 1986 by University of Toronto.
44 * Written by Henry Spencer. Not derived from licensed software.
45 *
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:
49 *
50 * 1. The author is not responsible for the consequences of use of
51 * this software, no matter how awful, even if they arise
52 * from defects in it.
53 *
54 * 2. The origin of this software must not be misrepresented, either
55 * by explicit claim or by omission.
56 *
57 * 3. Altered versions must be plainly marked as such, and must not
58 * be misrepresented as being the original software.
59 *
60 **** Alterations to Henry's code are...
61 ****
4bb101f2 62 **** Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
1129b882
NC
63 **** 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
64 **** by Larry Wall and others
a687059c 65 ****
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LW
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.
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68 *
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.
72 */
73#include "EXTERN.h"
864dbfa3 74#define PERL_IN_REGEXEC_C
a687059c 75#include "perl.h"
0f5d15d6 76
54df2634
NC
77#ifdef PERL_IN_XSUB_RE
78# include "re_comp.h"
79#else
80# include "regcomp.h"
81#endif
a687059c 82
ef07e810 83#define RF_tainted 1 /* tainted information used? e.g. locale */
c277df42 84#define RF_warned 2 /* warned about big count? */
faec1544 85
ab3bbdeb 86#define RF_utf8 8 /* Pattern contains multibyte chars? */
a0ed51b3 87
f2ed9b32 88#define UTF_PATTERN ((PL_reg_flags & RF_utf8) != 0)
ce862d02
IZ
89
90#define RS_init 1 /* eval environment created */
91#define RS_set 2 /* replsv value is set */
c277df42 92
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LW
93#ifndef STATIC
94#define STATIC static
95#endif
96
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KW
97/* Valid for non-utf8 strings, non-ANYOFV nodes only: avoids the reginclass
98 * call if there are no complications: i.e., if everything matchable is
99 * straight forward in the bitmap */
af364d03
KW
100#define REGINCLASS(prog,p,c) (ANYOF_FLAGS(p) ? reginclass(prog,p,c,0,0) \
101 : ANYOF_BITMAP_TEST(p,*(c)))
7d3e948e 102
c277df42
IZ
103/*
104 * Forwards.
105 */
106
f2ed9b32 107#define CHR_SVLEN(sv) (utf8_target ? sv_len_utf8(sv) : SvCUR(sv))
53c4c00c 108#define CHR_DIST(a,b) (PL_reg_match_utf8 ? utf8_distance(a,b) : a - b)
a0ed51b3 109
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YO
110#define HOPc(pos,off) \
111 (char *)(PL_reg_match_utf8 \
52657f30 112 ? reghop3((U8*)pos, off, (U8*)(off >= 0 ? PL_regeol : PL_bostr)) \
3dab1dad
YO
113 : (U8*)(pos + off))
114#define HOPBACKc(pos, off) \
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YO
115 (char*)(PL_reg_match_utf8\
116 ? reghopmaybe3((U8*)pos, -off, (U8*)PL_bostr) \
117 : (pos - off >= PL_bostr) \
8e11feef 118 ? (U8*)pos - off \
3dab1dad 119 : NULL)
efb30f32 120
e7409c1b 121#define HOP3(pos,off,lim) (PL_reg_match_utf8 ? reghop3((U8*)(pos), off, (U8*)(lim)) : (U8*)(pos + off))
1aa99e6b 122#define HOP3c(pos,off,lim) ((char*)HOP3(pos,off,lim))
1aa99e6b 123
20d0b1e9 124/* these are unrolled below in the CCC_TRY_XXX defined */
a9a337f8
KW
125#ifdef EBCDIC
126 /* Often 'str' is a hard-coded utf8 string instead of utfebcdic. so just
127 * skip the check on EBCDIC platforms */
128# define LOAD_UTF8_CHARCLASS(class,str) LOAD_UTF8_CHARCLASS_NO_CHECK(class)
129#else
130# define LOAD_UTF8_CHARCLASS(class,str) STMT_START { \
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RB
131 if (!CAT2(PL_utf8_,class)) { \
132 bool ok; \
133 ENTER; save_re_context(); \
134 ok=CAT2(is_utf8_,class)((const U8*)str); \
9ac792f4 135 assert(ok); assert(CAT2(PL_utf8_,class)); LEAVE; } } STMT_END
a9a337f8 136#endif
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KW
137
138/* Doesn't do an assert to verify that is correct */
139#define LOAD_UTF8_CHARCLASS_NO_CHECK(class) STMT_START { \
9c4fdda1
RB
140 if (!CAT2(PL_utf8_,class)) { \
141 bool throw_away __attribute__unused__; \
142 ENTER; save_re_context(); \
143 throw_away = CAT2(is_utf8_,class)((const U8*)" "); \
144 LEAVE; } } STMT_END
37e2e78e 145
1a4fad37
AL
146#define LOAD_UTF8_CHARCLASS_ALNUM() LOAD_UTF8_CHARCLASS(alnum,"a")
147#define LOAD_UTF8_CHARCLASS_DIGIT() LOAD_UTF8_CHARCLASS(digit,"0")
148#define LOAD_UTF8_CHARCLASS_SPACE() LOAD_UTF8_CHARCLASS(space," ")
51371543 149
37e2e78e 150#define LOAD_UTF8_CHARCLASS_GCB() /* Grapheme cluster boundaries */ \
d275fa5e
CB
151 LOAD_UTF8_CHARCLASS(X_begin, " "); \
152 LOAD_UTF8_CHARCLASS(X_non_hangul, "A"); \
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KW
153 /* These are utf8 constants, and not utf-ebcdic constants, so the \
154 * assert should likely and hopefully fail on an EBCDIC machine */ \
d275fa5e 155 LOAD_UTF8_CHARCLASS(X_extend, "\xcc\x80"); /* U+0300 */ \
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KW
156 \
157 /* No asserts are done for these, in case called on an early \
158 * Unicode version in which they map to nothing */ \
d275fa5e
CB
159 LOAD_UTF8_CHARCLASS_NO_CHECK(X_prepend);/* U+0E40 "\xe0\xb9\x80" */ \
160 LOAD_UTF8_CHARCLASS_NO_CHECK(X_L); /* U+1100 "\xe1\x84\x80" */ \
161 LOAD_UTF8_CHARCLASS_NO_CHECK(X_LV); /* U+AC00 "\xea\xb0\x80" */ \
162 LOAD_UTF8_CHARCLASS_NO_CHECK(X_LVT); /* U+AC01 "\xea\xb0\x81" */ \
163 LOAD_UTF8_CHARCLASS_NO_CHECK(X_LV_LVT_V);/* U+AC01 "\xea\xb0\x81" */\
164 LOAD_UTF8_CHARCLASS_NO_CHECK(X_T); /* U+11A8 "\xe1\x86\xa8" */ \
37e2e78e 165 LOAD_UTF8_CHARCLASS_NO_CHECK(X_V) /* U+1160 "\xe1\x85\xa0" */
20d0b1e9 166
1dcf4a1b 167#define PLACEHOLDER /* Something for the preprocessor to grab onto */
d1eb3177 168
ee9a90b8
KW
169/* The actual code for CCC_TRY, which uses several variables from the routine
170 * it's callable from. It is designed to be the bulk of a case statement.
171 * FUNC is the macro or function to call on non-utf8 targets that indicate if
172 * nextchr matches the class.
173 * UTF8_TEST is the whole test string to use for utf8 targets
174 * LOAD is what to use to test, and if not present to load in the swash for the
175 * class
176 * POS_OR_NEG is either empty or ! to complement the results of FUNC or
177 * UTF8_TEST test.
178 * The logic is: Fail if we're at the end-of-string; otherwise if the target is
179 * utf8 and a variant, load the swash if necessary and test using the utf8
180 * test. Advance to the next character if test is ok, otherwise fail; If not
181 * utf8 or an invariant under utf8, use the non-utf8 test, and fail if it
182 * fails, or advance to the next character */
183
184#define _CCC_TRY_CODE(POS_OR_NEG, FUNC, UTF8_TEST, CLASS, STR) \
185 if (locinput >= PL_regeol) { \
186 sayNO; \
187 } \
188 if (utf8_target && UTF8_IS_CONTINUED(nextchr)) { \
189 LOAD_UTF8_CHARCLASS(CLASS, STR); \
190 if (POS_OR_NEG (UTF8_TEST)) { \
191 sayNO; \
192 } \
193 locinput += PL_utf8skip[nextchr]; \
194 nextchr = UCHARAT(locinput); \
195 break; \
196 } \
197 if (POS_OR_NEG (FUNC(nextchr))) { \
198 sayNO; \
199 } \
200 nextchr = UCHARAT(++locinput); \
980866de
KW
201 break;
202
ee9a90b8
KW
203/* Handle the non-locale cases for a character class and its complement. It
204 * calls _CCC_TRY_CODE with a ! to complement the test for the character class.
205 * This is because that code fails when the test succeeds, so we want to have
206 * the test fail so that the code succeeds. The swash is stored in a
207 * predictable PL_ place */
cfaf538b
KW
208#define _CCC_TRY_NONLOCALE(NAME, NNAME, FUNC, \
209 CLASS, STR) \
ee9a90b8
KW
210 case NAME: \
211 _CCC_TRY_CODE( !, FUNC, \
212 cBOOL(swash_fetch(CAT2(PL_utf8_,CLASS), \
213 (U8*)locinput, TRUE)), \
214 CLASS, STR) \
215 case NNAME: \
1dcf4a1b 216 _CCC_TRY_CODE( PLACEHOLDER , FUNC, \
ee9a90b8
KW
217 cBOOL(swash_fetch(CAT2(PL_utf8_,CLASS), \
218 (U8*)locinput, TRUE)), \
219 CLASS, STR) \
220
221/* Generate the case statements for both locale and non-locale character
222 * classes in regmatch for classes that don't have special unicode semantics.
223 * Locales don't use an immediate swash, but an intermediary special locale
224 * function that is called on the pointer to the current place in the input
225 * string. That function will resolve to needing the same swash. One might
226 * think that because we don't know what the locale will match, we shouldn't
227 * check with the swash loading function that it loaded properly; ie, that we
228 * should use LOAD_UTF8_CHARCLASS_NO_CHECK for those, but what is passed to the
229 * regular LOAD_UTF8_CHARCLASS is in non-locale terms, and so locale is
230 * irrelevant here */
231#define CCC_TRY(NAME, NNAME, FUNC, \
232 NAMEL, NNAMEL, LCFUNC, LCFUNC_utf8, \
cfaf538b 233 NAMEA, NNAMEA, FUNCA, \
ee9a90b8
KW
234 CLASS, STR) \
235 case NAMEL: \
236 PL_reg_flags |= RF_tainted; \
237 _CCC_TRY_CODE( !, LCFUNC, LCFUNC_utf8((U8*)locinput), CLASS, STR) \
238 case NNAMEL: \
239 PL_reg_flags |= RF_tainted; \
1dcf4a1b
KW
240 _CCC_TRY_CODE( PLACEHOLDER, LCFUNC, LCFUNC_utf8((U8*)locinput), \
241 CLASS, STR) \
cfaf538b
KW
242 case NAMEA: \
243 if (locinput >= PL_regeol || ! FUNCA(nextchr)) { \
244 sayNO; \
245 } \
246 /* Matched a utf8-invariant, so don't have to worry about utf8 */ \
247 nextchr = UCHARAT(++locinput); \
248 break; \
249 case NNAMEA: \
250 if (locinput >= PL_regeol || FUNCA(nextchr)) { \
251 sayNO; \
252 } \
253 if (utf8_target) { \
254 locinput += PL_utf8skip[nextchr]; \
255 nextchr = UCHARAT(locinput); \
256 } \
257 else { \
258 nextchr = UCHARAT(++locinput); \
259 } \
260 break; \
ee9a90b8
KW
261 /* Generate the non-locale cases */ \
262 _CCC_TRY_NONLOCALE(NAME, NNAME, FUNC, CLASS, STR)
263
264/* This is like CCC_TRY, but has an extra set of parameters for generating case
265 * statements to handle separate Unicode semantics nodes */
266#define CCC_TRY_U(NAME, NNAME, FUNC, \
267 NAMEL, NNAMEL, LCFUNC, LCFUNC_utf8, \
268 NAMEU, NNAMEU, FUNCU, \
cfaf538b 269 NAMEA, NNAMEA, FUNCA, \
ee9a90b8 270 CLASS, STR) \
cfaf538b
KW
271 CCC_TRY(NAME, NNAME, FUNC, \
272 NAMEL, NNAMEL, LCFUNC, LCFUNC_utf8, \
273 NAMEA, NNAMEA, FUNCA, \
274 CLASS, STR) \
ee9a90b8 275 _CCC_TRY_NONLOCALE(NAMEU, NNAMEU, FUNCU, CLASS, STR)
d1eb3177 276
3dab1dad
YO
277/* TODO: Combine JUMPABLE and HAS_TEXT to cache OP(rn) */
278
5f80c4cf 279/* for use after a quantifier and before an EXACT-like node -- japhy */
c35dcbe2
YO
280/* it would be nice to rework regcomp.sym to generate this stuff. sigh
281 *
282 * NOTE that *nothing* that affects backtracking should be in here, specifically
283 * VERBS must NOT be included. JUMPABLE is used to determine if we can ignore a
284 * node that is in between two EXACT like nodes when ascertaining what the required
285 * "follow" character is. This should probably be moved to regex compile time
286 * although it may be done at run time beause of the REF possibility - more
287 * investigation required. -- demerphq
288*/
3e901dc0
YO
289#define JUMPABLE(rn) ( \
290 OP(rn) == OPEN || \
291 (OP(rn) == CLOSE && (!cur_eval || cur_eval->u.eval.close_paren != ARG(rn))) || \
292 OP(rn) == EVAL || \
cca55fe3
JP
293 OP(rn) == SUSPEND || OP(rn) == IFMATCH || \
294 OP(rn) == PLUS || OP(rn) == MINMOD || \
d1c771f5 295 OP(rn) == KEEPS || \
3dab1dad 296 (PL_regkind[OP(rn)] == CURLY && ARG1(rn) > 0) \
e2d8ce26 297)
ee9b8eae 298#define IS_EXACT(rn) (PL_regkind[OP(rn)] == EXACT)
e2d8ce26 299
ee9b8eae
YO
300#define HAS_TEXT(rn) ( IS_EXACT(rn) || PL_regkind[OP(rn)] == REF )
301
302#if 0
303/* Currently these are only used when PL_regkind[OP(rn)] == EXACT so
304 we don't need this definition. */
305#define IS_TEXT(rn) ( OP(rn)==EXACT || OP(rn)==REF || OP(rn)==NREF )
2f7f8cb1 306#define IS_TEXTF(rn) ( (OP(rn)==EXACTFU || OP(rn)==EXACTFA || OP(rn)==EXACTF) || OP(rn)==REFF || OP(rn)==NREFF )
ee9b8eae
YO
307#define IS_TEXTFL(rn) ( OP(rn)==EXACTFL || OP(rn)==REFFL || OP(rn)==NREFFL )
308
309#else
310/* ... so we use this as its faster. */
311#define IS_TEXT(rn) ( OP(rn)==EXACT )
2f7f8cb1 312#define IS_TEXTFU(rn) ( OP(rn)==EXACTFU || OP(rn) == EXACTFA)
ee9b8eae
YO
313#define IS_TEXTF(rn) ( OP(rn)==EXACTF )
314#define IS_TEXTFL(rn) ( OP(rn)==EXACTFL )
315
316#endif
e2d8ce26 317
a84d97b6
HS
318/*
319 Search for mandatory following text node; for lookahead, the text must
320 follow but for lookbehind (rn->flags != 0) we skip to the next step.
321*/
cca55fe3 322#define FIND_NEXT_IMPT(rn) STMT_START { \
3dab1dad
YO
323 while (JUMPABLE(rn)) { \
324 const OPCODE type = OP(rn); \
325 if (type == SUSPEND || PL_regkind[type] == CURLY) \
e2d8ce26 326 rn = NEXTOPER(NEXTOPER(rn)); \
3dab1dad 327 else if (type == PLUS) \
cca55fe3 328 rn = NEXTOPER(rn); \
3dab1dad 329 else if (type == IFMATCH) \
a84d97b6 330 rn = (rn->flags == 0) ? NEXTOPER(NEXTOPER(rn)) : rn + ARG(rn); \
e2d8ce26 331 else rn += NEXT_OFF(rn); \
3dab1dad 332 } \
5f80c4cf 333} STMT_END
74750237 334
c476f425 335
acfe0abc 336static void restore_pos(pTHX_ void *arg);
51371543 337
620d5b66
NC
338#define REGCP_PAREN_ELEMS 4
339#define REGCP_OTHER_ELEMS 5
e0fa7e2b 340#define REGCP_FRAME_ELEMS 1
620d5b66
NC
341/* REGCP_FRAME_ELEMS are not part of the REGCP_OTHER_ELEMS and
342 * are needed for the regexp context stack bookkeeping. */
343
76e3520e 344STATIC CHECKPOINT
cea2e8a9 345S_regcppush(pTHX_ I32 parenfloor)
a0d0e21e 346{
97aff369 347 dVAR;
a3b680e6 348 const int retval = PL_savestack_ix;
a3b680e6 349 const int paren_elems_to_push = (PL_regsize - parenfloor) * REGCP_PAREN_ELEMS;
e0fa7e2b
NC
350 const UV total_elems = paren_elems_to_push + REGCP_OTHER_ELEMS;
351 const UV elems_shifted = total_elems << SAVE_TIGHT_SHIFT;
a0d0e21e 352 int p;
40a82448 353 GET_RE_DEBUG_FLAGS_DECL;
a0d0e21e 354
e49a9654
IH
355 if (paren_elems_to_push < 0)
356 Perl_croak(aTHX_ "panic: paren_elems_to_push < 0");
357
e0fa7e2b
NC
358 if ((elems_shifted >> SAVE_TIGHT_SHIFT) != total_elems)
359 Perl_croak(aTHX_ "panic: paren_elems_to_push offset %"UVuf
5df417d0
JH
360 " out of range (%lu-%ld)",
361 total_elems, (unsigned long)PL_regsize, (long)parenfloor);
e0fa7e2b 362
620d5b66 363 SSGROW(total_elems + REGCP_FRAME_ELEMS);
7f69552c 364
3280af22 365 for (p = PL_regsize; p > parenfloor; p--) {
b1ce53c5 366/* REGCP_PARENS_ELEMS are pushed per pairs of parentheses. */
f0ab9afb
NC
367 SSPUSHINT(PL_regoffs[p].end);
368 SSPUSHINT(PL_regoffs[p].start);
3280af22 369 SSPUSHPTR(PL_reg_start_tmp[p]);
a0d0e21e 370 SSPUSHINT(p);
e7707071 371 DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
40a82448 372 " saving \\%"UVuf" %"IVdf"(%"IVdf")..%"IVdf"\n",
f0ab9afb 373 (UV)p, (IV)PL_regoffs[p].start,
40a82448 374 (IV)(PL_reg_start_tmp[p] - PL_bostr),
f0ab9afb 375 (IV)PL_regoffs[p].end
40a82448 376 ));
a0d0e21e 377 }
b1ce53c5 378/* REGCP_OTHER_ELEMS are pushed in any case, parentheses or no. */
f0ab9afb 379 SSPUSHPTR(PL_regoffs);
3280af22
NIS
380 SSPUSHINT(PL_regsize);
381 SSPUSHINT(*PL_reglastparen);
a01268b5 382 SSPUSHINT(*PL_reglastcloseparen);
3280af22 383 SSPUSHPTR(PL_reginput);
e0fa7e2b 384 SSPUSHUV(SAVEt_REGCONTEXT | elems_shifted); /* Magic cookie. */
41123dfd 385
a0d0e21e
LW
386 return retval;
387}
388
c277df42 389/* These are needed since we do not localize EVAL nodes: */
ab3bbdeb
YO
390#define REGCP_SET(cp) \
391 DEBUG_STATE_r( \
ab3bbdeb 392 PerlIO_printf(Perl_debug_log, \
e4f74956 393 " Setting an EVAL scope, savestack=%"IVdf"\n", \
ab3bbdeb
YO
394 (IV)PL_savestack_ix)); \
395 cp = PL_savestack_ix
c3464db5 396
ab3bbdeb 397#define REGCP_UNWIND(cp) \
e4f74956 398 DEBUG_STATE_r( \
ab3bbdeb 399 if (cp != PL_savestack_ix) \
e4f74956
YO
400 PerlIO_printf(Perl_debug_log, \
401 " Clearing an EVAL scope, savestack=%"IVdf"..%"IVdf"\n", \
ab3bbdeb
YO
402 (IV)(cp), (IV)PL_savestack_ix)); \
403 regcpblow(cp)
c277df42 404
76e3520e 405STATIC char *
097eb12c 406S_regcppop(pTHX_ const regexp *rex)
a0d0e21e 407{
97aff369 408 dVAR;
e0fa7e2b 409 UV i;
a0d0e21e 410 char *input;
a3621e74
YO
411 GET_RE_DEBUG_FLAGS_DECL;
412
7918f24d
NC
413 PERL_ARGS_ASSERT_REGCPPOP;
414
b1ce53c5 415 /* Pop REGCP_OTHER_ELEMS before the parentheses loop starts. */
c6bf6a65 416 i = SSPOPUV;
e0fa7e2b
NC
417 assert((i & SAVE_MASK) == SAVEt_REGCONTEXT); /* Check that the magic cookie is there. */
418 i >>= SAVE_TIGHT_SHIFT; /* Parentheses elements to pop. */
a0d0e21e 419 input = (char *) SSPOPPTR;
a01268b5 420 *PL_reglastcloseparen = SSPOPINT;
3280af22
NIS
421 *PL_reglastparen = SSPOPINT;
422 PL_regsize = SSPOPINT;
f0ab9afb 423 PL_regoffs=(regexp_paren_pair *) SSPOPPTR;
b1ce53c5 424
620d5b66 425 i -= REGCP_OTHER_ELEMS;
b1ce53c5 426 /* Now restore the parentheses context. */
620d5b66 427 for ( ; i > 0; i -= REGCP_PAREN_ELEMS) {
1df70142 428 I32 tmps;
097eb12c 429 U32 paren = (U32)SSPOPINT;
3280af22 430 PL_reg_start_tmp[paren] = (char *) SSPOPPTR;
f0ab9afb 431 PL_regoffs[paren].start = SSPOPINT;
cf93c79d 432 tmps = SSPOPINT;
3280af22 433 if (paren <= *PL_reglastparen)
f0ab9afb 434 PL_regoffs[paren].end = tmps;
e7707071 435 DEBUG_BUFFERS_r(
c3464db5 436 PerlIO_printf(Perl_debug_log,
b900a521 437 " restoring \\%"UVuf" to %"IVdf"(%"IVdf")..%"IVdf"%s\n",
f0ab9afb 438 (UV)paren, (IV)PL_regoffs[paren].start,
b900a521 439 (IV)(PL_reg_start_tmp[paren] - PL_bostr),
f0ab9afb 440 (IV)PL_regoffs[paren].end,
3280af22 441 (paren > *PL_reglastparen ? "(no)" : ""));
c277df42 442 );
a0d0e21e 443 }
e7707071 444 DEBUG_BUFFERS_r(
bb7a0f54 445 if (*PL_reglastparen + 1 <= rex->nparens) {
c3464db5 446 PerlIO_printf(Perl_debug_log,
faccc32b 447 " restoring \\%"IVdf"..\\%"IVdf" to undef\n",
4f639d21 448 (IV)(*PL_reglastparen + 1), (IV)rex->nparens);
c277df42
IZ
449 }
450 );
daf18116 451#if 1
dafc8851
JH
452 /* It would seem that the similar code in regtry()
453 * already takes care of this, and in fact it is in
454 * a better location to since this code can #if 0-ed out
455 * but the code in regtry() is needed or otherwise tests
456 * requiring null fields (pat.t#187 and split.t#{13,14}
daf18116
JH
457 * (as of patchlevel 7877) will fail. Then again,
458 * this code seems to be necessary or otherwise
225593e1
DM
459 * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
460 * --jhi updated by dapm */
3b6647e0 461 for (i = *PL_reglastparen + 1; i <= rex->nparens; i++) {
097eb12c 462 if (i > PL_regsize)
f0ab9afb
NC
463 PL_regoffs[i].start = -1;
464 PL_regoffs[i].end = -1;
a0d0e21e 465 }
dafc8851 466#endif
a0d0e21e
LW
467 return input;
468}
469
02db2b7b 470#define regcpblow(cp) LEAVE_SCOPE(cp) /* Ignores regcppush()ed data. */
a0d0e21e 471
a687059c 472/*
e50aee73 473 * pregexec and friends
a687059c
LW
474 */
475
76234dfb 476#ifndef PERL_IN_XSUB_RE
a687059c 477/*
c277df42 478 - pregexec - match a regexp against a string
a687059c 479 */
c277df42 480I32
49d7dfbc 481Perl_pregexec(pTHX_ REGEXP * const prog, char* stringarg, register char *strend,
c3464db5 482 char *strbeg, I32 minend, SV *screamer, U32 nosave)
c277df42
IZ
483/* strend: pointer to null at end of string */
484/* strbeg: real beginning of string */
485/* minend: end of match must be >=minend after stringarg. */
486/* nosave: For optimizations. */
487{
7918f24d
NC
488 PERL_ARGS_ASSERT_PREGEXEC;
489
c277df42 490 return
9041c2e3 491 regexec_flags(prog, stringarg, strend, strbeg, minend, screamer, NULL,
c277df42
IZ
492 nosave ? 0 : REXEC_COPY_STR);
493}
76234dfb 494#endif
22e551b9 495
9041c2e3 496/*
cad2e5aa
JH
497 * Need to implement the following flags for reg_anch:
498 *
499 * USE_INTUIT_NOML - Useful to call re_intuit_start() first
500 * USE_INTUIT_ML
501 * INTUIT_AUTORITATIVE_NOML - Can trust a positive answer
502 * INTUIT_AUTORITATIVE_ML
503 * INTUIT_ONCE_NOML - Intuit can match in one location only.
504 * INTUIT_ONCE_ML
505 *
506 * Another flag for this function: SECOND_TIME (so that float substrs
507 * with giant delta may be not rechecked).
508 */
509
510/* Assumptions: if ANCH_GPOS, then strpos is anchored. XXXX Check GPOS logic */
511
3f7c398e 512/* If SCREAM, then SvPVX_const(sv) should be compatible with strpos and strend.
cad2e5aa
JH
513 Otherwise, only SvCUR(sv) is used to get strbeg. */
514
515/* XXXX We assume that strpos is strbeg unless sv. */
516
6eb5f6b9
JH
517/* XXXX Some places assume that there is a fixed substring.
518 An update may be needed if optimizer marks as "INTUITable"
519 RExen without fixed substrings. Similarly, it is assumed that
520 lengths of all the strings are no more than minlen, thus they
521 cannot come from lookahead.
40d049e4
YO
522 (Or minlen should take into account lookahead.)
523 NOTE: Some of this comment is not correct. minlen does now take account
524 of lookahead/behind. Further research is required. -- demerphq
525
526*/
6eb5f6b9 527
2c2d71f5
JH
528/* A failure to find a constant substring means that there is no need to make
529 an expensive call to REx engine, thus we celebrate a failure. Similarly,
530 finding a substring too deep into the string means that less calls to
30944b6d
IZ
531 regtry() should be needed.
532
533 REx compiler's optimizer found 4 possible hints:
534 a) Anchored substring;
535 b) Fixed substring;
536 c) Whether we are anchored (beginning-of-line or \G);
486ec47a 537 d) First node (of those at offset 0) which may distinguish positions;
6eb5f6b9 538 We use a)b)d) and multiline-part of c), and try to find a position in the
30944b6d
IZ
539 string which does not contradict any of them.
540 */
2c2d71f5 541
6eb5f6b9
JH
542/* Most of decisions we do here should have been done at compile time.
543 The nodes of the REx which we used for the search should have been
544 deleted from the finite automaton. */
545
cad2e5aa 546char *
288b8c02 547Perl_re_intuit_start(pTHX_ REGEXP * const rx, SV *sv, char *strpos,
9f61653a 548 char *strend, const U32 flags, re_scream_pos_data *data)
cad2e5aa 549{
97aff369 550 dVAR;
288b8c02 551 struct regexp *const prog = (struct regexp *)SvANY(rx);
b7953727 552 register I32 start_shift = 0;
cad2e5aa 553 /* Should be nonnegative! */
b7953727 554 register I32 end_shift = 0;
2c2d71f5
JH
555 register char *s;
556 register SV *check;
a1933d95 557 char *strbeg;
cad2e5aa 558 char *t;
f2ed9b32 559 const bool utf8_target = (sv && SvUTF8(sv)) ? 1 : 0; /* if no sv we have to assume bytes */
cad2e5aa 560 I32 ml_anch;
bd61b366
SS
561 register char *other_last = NULL; /* other substr checked before this */
562 char *check_at = NULL; /* check substr found at this pos */
bbe252da 563 const I32 multiline = prog->extflags & RXf_PMf_MULTILINE;
f8fc2ecf 564 RXi_GET_DECL(prog,progi);
30944b6d 565#ifdef DEBUGGING
890ce7af 566 const char * const i_strpos = strpos;
30944b6d 567#endif
a3621e74
YO
568 GET_RE_DEBUG_FLAGS_DECL;
569
7918f24d
NC
570 PERL_ARGS_ASSERT_RE_INTUIT_START;
571
f2ed9b32 572 RX_MATCH_UTF8_set(rx,utf8_target);
cad2e5aa 573
3c8556c3 574 if (RX_UTF8(rx)) {
b8d68ded
JH
575 PL_reg_flags |= RF_utf8;
576 }
ab3bbdeb 577 DEBUG_EXECUTE_r(
f2ed9b32 578 debug_start_match(rx, utf8_target, strpos, strend,
1de06328
YO
579 sv ? "Guessing start of match in sv for"
580 : "Guessing start of match in string for");
2a782b5b 581 );
cad2e5aa 582
c344f387
JH
583 /* CHR_DIST() would be more correct here but it makes things slow. */
584 if (prog->minlen > strend - strpos) {
a3621e74 585 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
a72c7584 586 "String too short... [re_intuit_start]\n"));
cad2e5aa 587 goto fail;
2c2d71f5 588 }
1de06328 589
a1933d95 590 strbeg = (sv && SvPOK(sv)) ? strend - SvCUR(sv) : strpos;
1aa99e6b 591 PL_regeol = strend;
f2ed9b32 592 if (utf8_target) {
33b8afdf
JH
593 if (!prog->check_utf8 && prog->check_substr)
594 to_utf8_substr(prog);
595 check = prog->check_utf8;
596 } else {
597 if (!prog->check_substr && prog->check_utf8)
598 to_byte_substr(prog);
599 check = prog->check_substr;
600 }
1de06328 601 if (check == &PL_sv_undef) {
a3621e74 602 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
1de06328 603 "Non-utf8 string cannot match utf8 check string\n"));
33b8afdf
JH
604 goto fail;
605 }
bbe252da
YO
606 if (prog->extflags & RXf_ANCH) { /* Match at beg-of-str or after \n */
607 ml_anch = !( (prog->extflags & RXf_ANCH_SINGLE)
608 || ( (prog->extflags & RXf_ANCH_BOL)
7fba1cd6 609 && !multiline ) ); /* Check after \n? */
cad2e5aa 610
7e25d62c 611 if (!ml_anch) {
bbe252da
YO
612 if ( !(prog->extflags & RXf_ANCH_GPOS) /* Checked by the caller */
613 && !(prog->intflags & PREGf_IMPLICIT) /* not a real BOL */
3f7c398e 614 /* SvCUR is not set on references: SvRV and SvPVX_const overlap */
7e25d62c
JH
615 && sv && !SvROK(sv)
616 && (strpos != strbeg)) {
a3621e74 617 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Not at start...\n"));
7e25d62c
JH
618 goto fail;
619 }
620 if (prog->check_offset_min == prog->check_offset_max &&
bbe252da 621 !(prog->extflags & RXf_CANY_SEEN)) {
2c2d71f5 622 /* Substring at constant offset from beg-of-str... */
cad2e5aa
JH
623 I32 slen;
624
1aa99e6b 625 s = HOP3c(strpos, prog->check_offset_min, strend);
1de06328 626
653099ff
GS
627 if (SvTAIL(check)) {
628 slen = SvCUR(check); /* >= 1 */
cad2e5aa 629
9041c2e3 630 if ( strend - s > slen || strend - s < slen - 1
2c2d71f5 631 || (strend - s == slen && strend[-1] != '\n')) {
a3621e74 632 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "String too long...\n"));
2c2d71f5 633 goto fail_finish;
cad2e5aa
JH
634 }
635 /* Now should match s[0..slen-2] */
636 slen--;
3f7c398e 637 if (slen && (*SvPVX_const(check) != *s
cad2e5aa 638 || (slen > 1
3f7c398e 639 && memNE(SvPVX_const(check), s, slen)))) {
2c2d71f5 640 report_neq:
a3621e74 641 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "String not equal...\n"));
2c2d71f5
JH
642 goto fail_finish;
643 }
cad2e5aa 644 }
3f7c398e 645 else if (*SvPVX_const(check) != *s
653099ff 646 || ((slen = SvCUR(check)) > 1
3f7c398e 647 && memNE(SvPVX_const(check), s, slen)))
2c2d71f5 648 goto report_neq;
c315bfe8 649 check_at = s;
2c2d71f5 650 goto success_at_start;
7e25d62c 651 }
cad2e5aa 652 }
2c2d71f5 653 /* Match is anchored, but substr is not anchored wrt beg-of-str. */
cad2e5aa 654 s = strpos;
2c2d71f5 655 start_shift = prog->check_offset_min; /* okay to underestimate on CC */
1de06328
YO
656 end_shift = prog->check_end_shift;
657
2c2d71f5 658 if (!ml_anch) {
a3b680e6 659 const I32 end = prog->check_offset_max + CHR_SVLEN(check)
653099ff 660 - (SvTAIL(check) != 0);
a3b680e6 661 const I32 eshift = CHR_DIST((U8*)strend, (U8*)s) - end;
2c2d71f5
JH
662
663 if (end_shift < eshift)
664 end_shift = eshift;
665 }
cad2e5aa 666 }
2c2d71f5 667 else { /* Can match at random position */
cad2e5aa
JH
668 ml_anch = 0;
669 s = strpos;
1de06328
YO
670 start_shift = prog->check_offset_min; /* okay to underestimate on CC */
671 end_shift = prog->check_end_shift;
672
673 /* end shift should be non negative here */
cad2e5aa
JH
674 }
675
bcdf7404 676#ifdef QDEBUGGING /* 7/99: reports of failure (with the older version) */
0033605d 677 if (end_shift < 0)
1de06328 678 Perl_croak(aTHX_ "panic: end_shift: %"IVdf" pattern:\n%s\n ",
220fc49f 679 (IV)end_shift, RX_PRECOMP(prog));
2c2d71f5
JH
680#endif
681
2c2d71f5
JH
682 restart:
683 /* Find a possible match in the region s..strend by looking for
684 the "check" substring in the region corrected by start/end_shift. */
1de06328
YO
685
686 {
687 I32 srch_start_shift = start_shift;
688 I32 srch_end_shift = end_shift;
689 if (srch_start_shift < 0 && strbeg - s > srch_start_shift) {
690 srch_end_shift -= ((strbeg - s) - srch_start_shift);
691 srch_start_shift = strbeg - s;
692 }
6bda09f9 693 DEBUG_OPTIMISE_MORE_r({
1de06328
YO
694 PerlIO_printf(Perl_debug_log, "Check offset min: %"IVdf" Start shift: %"IVdf" End shift %"IVdf" Real End Shift: %"IVdf"\n",
695 (IV)prog->check_offset_min,
696 (IV)srch_start_shift,
697 (IV)srch_end_shift,
698 (IV)prog->check_end_shift);
699 });
700
f1905e1b 701 if ((flags & REXEC_SCREAM) && SvSCREAM(sv)) {
cad2e5aa 702 I32 p = -1; /* Internal iterator of scream. */
a3b680e6 703 I32 * const pp = data ? data->scream_pos : &p;
4185c919 704 const MAGIC *mg;
72de20cd 705 bool found = FALSE;
cad2e5aa 706
4185c919
NC
707 assert(SvMAGICAL(sv));
708 mg = mg_find(sv, PERL_MAGIC_study);
709 assert(mg);
710
72de20cd
NC
711 if (mg->mg_private == 1) {
712 found = ((U8 *)mg->mg_ptr)[BmRARE(check)] != (U8)~0;
713 } else if (mg->mg_private == 2) {
714 found = ((U16 *)mg->mg_ptr)[BmRARE(check)] != (U16)~0;
715 } else {
716 assert (mg->mg_private == 4);
717 found = ((U32 *)mg->mg_ptr)[BmRARE(check)] != (U32)~0;
718 }
719
720 if (found
2c2d71f5 721 || ( BmRARE(check) == '\n'
85c508c3 722 && (BmPREVIOUS(check) == SvCUR(check) - 1)
2c2d71f5 723 && SvTAIL(check) ))
9041c2e3 724 s = screaminstr(sv, check,
1de06328 725 srch_start_shift + (s - strbeg), srch_end_shift, pp, 0);
cad2e5aa 726 else
2c2d71f5 727 goto fail_finish;
4addbd3b 728 /* we may be pointing at the wrong string */
07bc277f 729 if (s && RXp_MATCH_COPIED(prog))
3f7c398e 730 s = strbeg + (s - SvPVX_const(sv));
cad2e5aa
JH
731 if (data)
732 *data->scream_olds = s;
733 }
1de06328
YO
734 else {
735 U8* start_point;
736 U8* end_point;
bbe252da 737 if (prog->extflags & RXf_CANY_SEEN) {
1de06328
YO
738 start_point= (U8*)(s + srch_start_shift);
739 end_point= (U8*)(strend - srch_end_shift);
740 } else {
741 start_point= HOP3(s, srch_start_shift, srch_start_shift < 0 ? strbeg : strend);
742 end_point= HOP3(strend, -srch_end_shift, strbeg);
743 }
6bda09f9 744 DEBUG_OPTIMISE_MORE_r({
56570a2c 745 PerlIO_printf(Perl_debug_log, "fbm_instr len=%d str=<%.*s>\n",
1de06328 746 (int)(end_point - start_point),
fc8cd66c 747 (int)(end_point - start_point) > 20 ? 20 : (int)(end_point - start_point),
1de06328
YO
748 start_point);
749 });
750
751 s = fbm_instr( start_point, end_point,
7fba1cd6 752 check, multiline ? FBMrf_MULTILINE : 0);
1de06328
YO
753 }
754 }
cad2e5aa
JH
755 /* Update the count-of-usability, remove useless subpatterns,
756 unshift s. */
2c2d71f5 757
ab3bbdeb 758 DEBUG_EXECUTE_r({
f2ed9b32 759 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
ab3bbdeb
YO
760 SvPVX_const(check), RE_SV_DUMPLEN(check), 30);
761 PerlIO_printf(Perl_debug_log, "%s %s substr %s%s%s",
2c2d71f5 762 (s ? "Found" : "Did not find"),
f2ed9b32 763 (check == (utf8_target ? prog->anchored_utf8 : prog->anchored_substr)
ab3bbdeb
YO
764 ? "anchored" : "floating"),
765 quoted,
766 RE_SV_TAIL(check),
767 (s ? " at offset " : "...\n") );
768 });
2c2d71f5
JH
769
770 if (!s)
771 goto fail_finish;
2c2d71f5 772 /* Finish the diagnostic message */
a3621e74 773 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%ld...\n", (long)(s - i_strpos)) );
2c2d71f5 774
1de06328
YO
775 /* XXX dmq: first branch is for positive lookbehind...
776 Our check string is offset from the beginning of the pattern.
777 So we need to do any stclass tests offset forward from that
778 point. I think. :-(
779 */
780
781
782
783 check_at=s;
784
785
2c2d71f5
JH
786 /* Got a candidate. Check MBOL anchoring, and the *other* substr.
787 Start with the other substr.
788 XXXX no SCREAM optimization yet - and a very coarse implementation
a0288114 789 XXXX /ttx+/ results in anchored="ttx", floating="x". floating will
2c2d71f5
JH
790 *always* match. Probably should be marked during compile...
791 Probably it is right to do no SCREAM here...
792 */
793
f2ed9b32 794 if (utf8_target ? (prog->float_utf8 && prog->anchored_utf8)
1de06328
YO
795 : (prog->float_substr && prog->anchored_substr))
796 {
30944b6d 797 /* Take into account the "other" substring. */
2c2d71f5
JH
798 /* XXXX May be hopelessly wrong for UTF... */
799 if (!other_last)
6eb5f6b9 800 other_last = strpos;
f2ed9b32 801 if (check == (utf8_target ? prog->float_utf8 : prog->float_substr)) {
30944b6d
IZ
802 do_other_anchored:
803 {
890ce7af
AL
804 char * const last = HOP3c(s, -start_shift, strbeg);
805 char *last1, *last2;
be8e71aa 806 char * const saved_s = s;
33b8afdf 807 SV* must;
2c2d71f5 808
2c2d71f5
JH
809 t = s - prog->check_offset_max;
810 if (s - strpos > prog->check_offset_max /* signed-corrected t > strpos */
f2ed9b32 811 && (!utf8_target
0ce71af7 812 || ((t = (char*)reghopmaybe3((U8*)s, -(prog->check_offset_max), (U8*)strpos))
2c2d71f5 813 && t > strpos)))
6f207bd3 814 NOOP;
2c2d71f5
JH
815 else
816 t = strpos;
1aa99e6b 817 t = HOP3c(t, prog->anchored_offset, strend);
6eb5f6b9
JH
818 if (t < other_last) /* These positions already checked */
819 t = other_last;
1aa99e6b 820 last2 = last1 = HOP3c(strend, -prog->minlen, strbeg);
2c2d71f5
JH
821 if (last < last1)
822 last1 = last;
1de06328
YO
823 /* XXXX It is not documented what units *_offsets are in.
824 We assume bytes, but this is clearly wrong.
825 Meaning this code needs to be carefully reviewed for errors.
826 dmq.
827 */
828
2c2d71f5 829 /* On end-of-str: see comment below. */
f2ed9b32 830 must = utf8_target ? prog->anchored_utf8 : prog->anchored_substr;
33b8afdf
JH
831 if (must == &PL_sv_undef) {
832 s = (char*)NULL;
1de06328 833 DEBUG_r(must = prog->anchored_utf8); /* for debug */
33b8afdf
JH
834 }
835 else
836 s = fbm_instr(
837 (unsigned char*)t,
838 HOP3(HOP3(last1, prog->anchored_offset, strend)
839 + SvCUR(must), -(SvTAIL(must)!=0), strbeg),
840 must,
7fba1cd6 841 multiline ? FBMrf_MULTILINE : 0
33b8afdf 842 );
ab3bbdeb 843 DEBUG_EXECUTE_r({
f2ed9b32 844 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
ab3bbdeb
YO
845 SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
846 PerlIO_printf(Perl_debug_log, "%s anchored substr %s%s",
2c2d71f5 847 (s ? "Found" : "Contradicts"),
ab3bbdeb
YO
848 quoted, RE_SV_TAIL(must));
849 });
850
851
2c2d71f5
JH
852 if (!s) {
853 if (last1 >= last2) {
a3621e74 854 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
2c2d71f5
JH
855 ", giving up...\n"));
856 goto fail_finish;
857 }
a3621e74 858 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
2c2d71f5 859 ", trying floating at offset %ld...\n",
be8e71aa 860 (long)(HOP3c(saved_s, 1, strend) - i_strpos)));
1aa99e6b
IH
861 other_last = HOP3c(last1, prog->anchored_offset+1, strend);
862 s = HOP3c(last, 1, strend);
2c2d71f5
JH
863 goto restart;
864 }
865 else {
a3621e74 866 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, " at offset %ld...\n",
30944b6d 867 (long)(s - i_strpos)));
1aa99e6b
IH
868 t = HOP3c(s, -prog->anchored_offset, strbeg);
869 other_last = HOP3c(s, 1, strend);
be8e71aa 870 s = saved_s;
2c2d71f5
JH
871 if (t == strpos)
872 goto try_at_start;
2c2d71f5
JH
873 goto try_at_offset;
874 }
30944b6d 875 }
2c2d71f5
JH
876 }
877 else { /* Take into account the floating substring. */
33b8afdf 878 char *last, *last1;
be8e71aa 879 char * const saved_s = s;
33b8afdf
JH
880 SV* must;
881
882 t = HOP3c(s, -start_shift, strbeg);
883 last1 = last =
884 HOP3c(strend, -prog->minlen + prog->float_min_offset, strbeg);
885 if (CHR_DIST((U8*)last, (U8*)t) > prog->float_max_offset)
886 last = HOP3c(t, prog->float_max_offset, strend);
887 s = HOP3c(t, prog->float_min_offset, strend);
888 if (s < other_last)
889 s = other_last;
2c2d71f5 890 /* XXXX It is not documented what units *_offsets are in. Assume bytes. */
f2ed9b32 891 must = utf8_target ? prog->float_utf8 : prog->float_substr;
33b8afdf
JH
892 /* fbm_instr() takes into account exact value of end-of-str
893 if the check is SvTAIL(ed). Since false positives are OK,
894 and end-of-str is not later than strend we are OK. */
895 if (must == &PL_sv_undef) {
896 s = (char*)NULL;
1de06328 897 DEBUG_r(must = prog->float_utf8); /* for debug message */
33b8afdf
JH
898 }
899 else
2c2d71f5 900 s = fbm_instr((unsigned char*)s,
33b8afdf
JH
901 (unsigned char*)last + SvCUR(must)
902 - (SvTAIL(must)!=0),
7fba1cd6 903 must, multiline ? FBMrf_MULTILINE : 0);
ab3bbdeb 904 DEBUG_EXECUTE_r({
f2ed9b32 905 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
ab3bbdeb
YO
906 SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
907 PerlIO_printf(Perl_debug_log, "%s floating substr %s%s",
33b8afdf 908 (s ? "Found" : "Contradicts"),
ab3bbdeb
YO
909 quoted, RE_SV_TAIL(must));
910 });
33b8afdf
JH
911 if (!s) {
912 if (last1 == last) {
a3621e74 913 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
33b8afdf
JH
914 ", giving up...\n"));
915 goto fail_finish;
2c2d71f5 916 }
a3621e74 917 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
33b8afdf 918 ", trying anchored starting at offset %ld...\n",
be8e71aa 919 (long)(saved_s + 1 - i_strpos)));
33b8afdf
JH
920 other_last = last;
921 s = HOP3c(t, 1, strend);
922 goto restart;
923 }
924 else {
a3621e74 925 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, " at offset %ld...\n",
33b8afdf
JH
926 (long)(s - i_strpos)));
927 other_last = s; /* Fix this later. --Hugo */
be8e71aa 928 s = saved_s;
33b8afdf
JH
929 if (t == strpos)
930 goto try_at_start;
931 goto try_at_offset;
932 }
2c2d71f5 933 }
cad2e5aa 934 }
2c2d71f5 935
1de06328 936
9ef43ace 937 t= (char*)HOP3( s, -prog->check_offset_max, (prog->check_offset_max<0) ? strend : strpos);
1de06328 938
6bda09f9 939 DEBUG_OPTIMISE_MORE_r(
1de06328
YO
940 PerlIO_printf(Perl_debug_log,
941 "Check offset min:%"IVdf" max:%"IVdf" S:%"IVdf" t:%"IVdf" D:%"IVdf" end:%"IVdf"\n",
942 (IV)prog->check_offset_min,
943 (IV)prog->check_offset_max,
944 (IV)(s-strpos),
945 (IV)(t-strpos),
946 (IV)(t-s),
947 (IV)(strend-strpos)
948 )
949 );
950
2c2d71f5 951 if (s - strpos > prog->check_offset_max /* signed-corrected t > strpos */
f2ed9b32 952 && (!utf8_target
9ef43ace 953 || ((t = (char*)reghopmaybe3((U8*)s, -prog->check_offset_max, (U8*) ((prog->check_offset_max<0) ? strend : strpos)))
1de06328
YO
954 && t > strpos)))
955 {
2c2d71f5
JH
956 /* Fixed substring is found far enough so that the match
957 cannot start at strpos. */
958 try_at_offset:
cad2e5aa 959 if (ml_anch && t[-1] != '\n') {
30944b6d
IZ
960 /* Eventually fbm_*() should handle this, but often
961 anchored_offset is not 0, so this check will not be wasted. */
962 /* XXXX In the code below we prefer to look for "^" even in
963 presence of anchored substrings. And we search even
964 beyond the found float position. These pessimizations
965 are historical artefacts only. */
966 find_anchor:
2c2d71f5 967 while (t < strend - prog->minlen) {
cad2e5aa 968 if (*t == '\n') {
4ee3650e 969 if (t < check_at - prog->check_offset_min) {
f2ed9b32 970 if (utf8_target ? prog->anchored_utf8 : prog->anchored_substr) {
4ee3650e
GS
971 /* Since we moved from the found position,
972 we definitely contradict the found anchored
30944b6d
IZ
973 substr. Due to the above check we do not
974 contradict "check" substr.
975 Thus we can arrive here only if check substr
976 is float. Redo checking for "other"=="fixed".
977 */
9041c2e3 978 strpos = t + 1;
a3621e74 979 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Found /%s^%s/m at offset %ld, rescanning for anchored from offset %ld...\n",
e4584336 980 PL_colors[0], PL_colors[1], (long)(strpos - i_strpos), (long)(strpos - i_strpos + prog->anchored_offset)));
30944b6d
IZ
981 goto do_other_anchored;
982 }
4ee3650e
GS
983 /* We don't contradict the found floating substring. */
984 /* XXXX Why not check for STCLASS? */
cad2e5aa 985 s = t + 1;
a3621e74 986 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Found /%s^%s/m at offset %ld...\n",
e4584336 987 PL_colors[0], PL_colors[1], (long)(s - i_strpos)));
cad2e5aa
JH
988 goto set_useful;
989 }
4ee3650e
GS
990 /* Position contradicts check-string */
991 /* XXXX probably better to look for check-string
992 than for "\n", so one should lower the limit for t? */
a3621e74 993 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Found /%s^%s/m, restarting lookup for check-string at offset %ld...\n",
e4584336 994 PL_colors[0], PL_colors[1], (long)(t + 1 - i_strpos)));
0e41cd87 995 other_last = strpos = s = t + 1;
cad2e5aa
JH
996 goto restart;
997 }
998 t++;
999 }
a3621e74 1000 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Did not find /%s^%s/m...\n",
e4584336 1001 PL_colors[0], PL_colors[1]));
2c2d71f5 1002 goto fail_finish;
cad2e5aa 1003 }
f5952150 1004 else {
a3621e74 1005 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Starting position does not contradict /%s^%s/m...\n",
e4584336 1006 PL_colors[0], PL_colors[1]));
f5952150 1007 }
cad2e5aa
JH
1008 s = t;
1009 set_useful:
f2ed9b32 1010 ++BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr); /* hooray/5 */
cad2e5aa
JH
1011 }
1012 else {
f5952150 1013 /* The found string does not prohibit matching at strpos,
2c2d71f5 1014 - no optimization of calling REx engine can be performed,
f5952150
GS
1015 unless it was an MBOL and we are not after MBOL,
1016 or a future STCLASS check will fail this. */
2c2d71f5
JH
1017 try_at_start:
1018 /* Even in this situation we may use MBOL flag if strpos is offset
1019 wrt the start of the string. */
05b4157f 1020 if (ml_anch && sv && !SvROK(sv) /* See prev comment on SvROK */
a1933d95 1021 && (strpos != strbeg) && strpos[-1] != '\n'
d506a20d 1022 /* May be due to an implicit anchor of m{.*foo} */
bbe252da 1023 && !(prog->intflags & PREGf_IMPLICIT))
d506a20d 1024 {
cad2e5aa
JH
1025 t = strpos;
1026 goto find_anchor;
1027 }
a3621e74 1028 DEBUG_EXECUTE_r( if (ml_anch)
f5952150 1029 PerlIO_printf(Perl_debug_log, "Position at offset %ld does not contradict /%s^%s/m...\n",
70685ca0 1030 (long)(strpos - i_strpos), PL_colors[0], PL_colors[1]);
30944b6d 1031 );
2c2d71f5 1032 success_at_start:
bbe252da 1033 if (!(prog->intflags & PREGf_NAUGHTY) /* XXXX If strpos moved? */
f2ed9b32 1034 && (utf8_target ? (
33b8afdf
JH
1035 prog->check_utf8 /* Could be deleted already */
1036 && --BmUSEFUL(prog->check_utf8) < 0
1037 && (prog->check_utf8 == prog->float_utf8)
1038 ) : (
1039 prog->check_substr /* Could be deleted already */
1040 && --BmUSEFUL(prog->check_substr) < 0
1041 && (prog->check_substr == prog->float_substr)
1042 )))
66e933ab 1043 {
cad2e5aa 1044 /* If flags & SOMETHING - do not do it many times on the same match */
a3621e74 1045 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "... Disabling check substring...\n"));
f2ed9b32
KW
1046 /* XXX Does the destruction order has to change with utf8_target? */
1047 SvREFCNT_dec(utf8_target ? prog->check_utf8 : prog->check_substr);
1048 SvREFCNT_dec(utf8_target ? prog->check_substr : prog->check_utf8);
a0714e2c
SS
1049 prog->check_substr = prog->check_utf8 = NULL; /* disable */
1050 prog->float_substr = prog->float_utf8 = NULL; /* clear */
1051 check = NULL; /* abort */
cad2e5aa 1052 s = strpos;
486ec47a 1053 /* XXXX If the check string was an implicit check MBOL, then we need to unset the relevant flag
c9415951
YO
1054 see http://bugs.activestate.com/show_bug.cgi?id=87173 */
1055 if (prog->intflags & PREGf_IMPLICIT)
1056 prog->extflags &= ~RXf_ANCH_MBOL;
3cf5c195
IZ
1057 /* XXXX This is a remnant of the old implementation. It
1058 looks wasteful, since now INTUIT can use many
6eb5f6b9 1059 other heuristics. */
bbe252da 1060 prog->extflags &= ~RXf_USE_INTUIT;
c9415951 1061 /* XXXX What other flags might need to be cleared in this branch? */
cad2e5aa
JH
1062 }
1063 else
1064 s = strpos;
1065 }
1066
6eb5f6b9
JH
1067 /* Last resort... */
1068 /* XXXX BmUSEFUL already changed, maybe multiple change is meaningful... */
1de06328
YO
1069 /* trie stclasses are too expensive to use here, we are better off to
1070 leave it to regmatch itself */
f8fc2ecf 1071 if (progi->regstclass && PL_regkind[OP(progi->regstclass)]!=TRIE) {
6eb5f6b9
JH
1072 /* minlen == 0 is possible if regstclass is \b or \B,
1073 and the fixed substr is ''$.
1074 Since minlen is already taken into account, s+1 is before strend;
1075 accidentally, minlen >= 1 guaranties no false positives at s + 1
1076 even for \b or \B. But (minlen? 1 : 0) below assumes that
1077 regstclass does not come from lookahead... */
1078 /* If regstclass takes bytelength more than 1: If charlength==1, OK.
af944926 1079 This leaves EXACTF-ish only, which are dealt with in find_byclass(). */
f8fc2ecf
YO
1080 const U8* const str = (U8*)STRING(progi->regstclass);
1081 const int cl_l = (PL_regkind[OP(progi->regstclass)] == EXACT
1082 ? CHR_DIST(str+STR_LEN(progi->regstclass), str)
66e933ab 1083 : 1);
1de06328
YO
1084 char * endpos;
1085 if (prog->anchored_substr || prog->anchored_utf8 || ml_anch)
1086 endpos= HOP3c(s, (prog->minlen ? cl_l : 0), strend);
1087 else if (prog->float_substr || prog->float_utf8)
1088 endpos= HOP3c(HOP3c(check_at, -start_shift, strbeg), cl_l, strend);
1089 else
1090 endpos= strend;
1091
70685ca0
JH
1092 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "start_shift: %"IVdf" check_at: %"IVdf" s: %"IVdf" endpos: %"IVdf"\n",
1093 (IV)start_shift, (IV)(check_at - strbeg), (IV)(s - strbeg), (IV)(endpos - strbeg)));
1de06328 1094
6eb5f6b9 1095 t = s;
f8fc2ecf 1096 s = find_byclass(prog, progi->regstclass, s, endpos, NULL);
6eb5f6b9
JH
1097 if (!s) {
1098#ifdef DEBUGGING
cbbf8932 1099 const char *what = NULL;
6eb5f6b9
JH
1100#endif
1101 if (endpos == strend) {
a3621e74 1102 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
6eb5f6b9
JH
1103 "Could not match STCLASS...\n") );
1104 goto fail;
1105 }
a3621e74 1106 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
66e933ab 1107 "This position contradicts STCLASS...\n") );
bbe252da 1108 if ((prog->extflags & RXf_ANCH) && !ml_anch)
653099ff 1109 goto fail;
6eb5f6b9 1110 /* Contradict one of substrings */
33b8afdf 1111 if (prog->anchored_substr || prog->anchored_utf8) {
f2ed9b32 1112 if ((utf8_target ? prog->anchored_utf8 : prog->anchored_substr) == check) {
a3621e74 1113 DEBUG_EXECUTE_r( what = "anchored" );
6eb5f6b9 1114 hop_and_restart:
1aa99e6b 1115 s = HOP3c(t, 1, strend);
66e933ab
GS
1116 if (s + start_shift + end_shift > strend) {
1117 /* XXXX Should be taken into account earlier? */
a3621e74 1118 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
66e933ab
GS
1119 "Could not match STCLASS...\n") );
1120 goto fail;
1121 }
5e39e1e5
HS
1122 if (!check)
1123 goto giveup;
a3621e74 1124 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
f5952150 1125 "Looking for %s substr starting at offset %ld...\n",
6eb5f6b9
JH
1126 what, (long)(s + start_shift - i_strpos)) );
1127 goto restart;
1128 }
66e933ab 1129 /* Have both, check_string is floating */
6eb5f6b9
JH
1130 if (t + start_shift >= check_at) /* Contradicts floating=check */
1131 goto retry_floating_check;
1132 /* Recheck anchored substring, but not floating... */
9041c2e3 1133 s = check_at;
5e39e1e5
HS
1134 if (!check)
1135 goto giveup;
a3621e74 1136 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
f5952150 1137 "Looking for anchored substr starting at offset %ld...\n",
6eb5f6b9
JH
1138 (long)(other_last - i_strpos)) );
1139 goto do_other_anchored;
1140 }
60e71179
GS
1141 /* Another way we could have checked stclass at the
1142 current position only: */
1143 if (ml_anch) {
1144 s = t = t + 1;
5e39e1e5
HS
1145 if (!check)
1146 goto giveup;
a3621e74 1147 DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
f5952150 1148 "Looking for /%s^%s/m starting at offset %ld...\n",
e4584336 1149 PL_colors[0], PL_colors[1], (long)(t - i_strpos)) );
60e71179 1150 goto try_at_offset;
66e933ab 1151 }
f2ed9b32 1152 if (!(utf8_target ? prog->float_utf8 : prog->float_substr)) /* Could have been deleted */
60e71179 1153 goto fail;
486ec47a 1154 /* Check is floating substring. */
6eb5f6b9
JH
1155 retry_floating_check:
1156 t = check_at - start_shift;
a3621e74 1157 DEBUG_EXECUTE_r( what = "floating" );
6eb5f6b9
JH
1158 goto hop_and_restart;
1159 }
b7953727 1160 if (t != s) {
a3621e74 1161 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
6eb5f6b9 1162 "By STCLASS: moving %ld --> %ld\n",
b7953727
JH
1163 (long)(t - i_strpos), (long)(s - i_strpos))
1164 );
1165 }
1166 else {
a3621e74 1167 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
b7953727
JH
1168 "Does not contradict STCLASS...\n");
1169 );
1170 }
6eb5f6b9 1171 }
5e39e1e5 1172 giveup:
a3621e74 1173 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%s%s:%s match at offset %ld\n",
5e39e1e5
HS
1174 PL_colors[4], (check ? "Guessed" : "Giving up"),
1175 PL_colors[5], (long)(s - i_strpos)) );
cad2e5aa 1176 return s;
2c2d71f5
JH
1177
1178 fail_finish: /* Substring not found */
33b8afdf 1179 if (prog->check_substr || prog->check_utf8) /* could be removed already */
f2ed9b32 1180 BmUSEFUL(utf8_target ? prog->check_utf8 : prog->check_substr) += 5; /* hooray */
cad2e5aa 1181 fail:
a3621e74 1182 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch rejected by optimizer%s\n",
e4584336 1183 PL_colors[4], PL_colors[5]));
bd61b366 1184 return NULL;
cad2e5aa 1185}
9661b544 1186
a0a388a1
YO
1187#define DECL_TRIE_TYPE(scan) \
1188 const enum { trie_plain, trie_utf8, trie_utf8_fold, trie_latin_utf8_fold } \
1189 trie_type = (scan->flags != EXACT) \
f2ed9b32
KW
1190 ? (utf8_target ? trie_utf8_fold : (UTF_PATTERN ? trie_latin_utf8_fold : trie_plain)) \
1191 : (utf8_target ? trie_utf8 : trie_plain)
3b0527fe 1192
55eed653
NC
1193#define REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc, uscan, len, \
1194uvc, charid, foldlen, foldbuf, uniflags) STMT_START { \
4cadc6a9
YO
1195 switch (trie_type) { \
1196 case trie_utf8_fold: \
1197 if ( foldlen>0 ) { \
0abd0d78 1198 uvc = utf8n_to_uvuni( uscan, UTF8_MAXLEN, &len, uniflags ); \
4cadc6a9
YO
1199 foldlen -= len; \
1200 uscan += len; \
1201 len=0; \
1202 } else { \
0abd0d78 1203 uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN, &len, uniflags ); \
4cadc6a9
YO
1204 uvc = to_uni_fold( uvc, foldbuf, &foldlen ); \
1205 foldlen -= UNISKIP( uvc ); \
1206 uscan = foldbuf + UNISKIP( uvc ); \
1207 } \
1208 break; \
a0a388a1
YO
1209 case trie_latin_utf8_fold: \
1210 if ( foldlen>0 ) { \
1211 uvc = utf8n_to_uvuni( uscan, UTF8_MAXLEN, &len, uniflags ); \
1212 foldlen -= len; \
1213 uscan += len; \
1214 len=0; \
1215 } else { \
1216 len = 1; \
1217 uvc = to_uni_fold( *(U8*)uc, foldbuf, &foldlen ); \
1218 foldlen -= UNISKIP( uvc ); \
1219 uscan = foldbuf + UNISKIP( uvc ); \
1220 } \
1221 break; \
4cadc6a9
YO
1222 case trie_utf8: \
1223 uvc = utf8n_to_uvuni( (U8*)uc, UTF8_MAXLEN, &len, uniflags ); \
1224 break; \
1225 case trie_plain: \
1226 uvc = (UV)*uc; \
1227 len = 1; \
1228 } \
4cadc6a9
YO
1229 if (uvc < 256) { \
1230 charid = trie->charmap[ uvc ]; \
1231 } \
1232 else { \
1233 charid = 0; \
55eed653
NC
1234 if (widecharmap) { \
1235 SV** const svpp = hv_fetch(widecharmap, \
4cadc6a9
YO
1236 (char*)&uvc, sizeof(UV), 0); \
1237 if (svpp) \
1238 charid = (U16)SvIV(*svpp); \
1239 } \
1240 } \
1241} STMT_END
1242
4cadc6a9
YO
1243#define REXEC_FBC_EXACTISH_SCAN(CoNd) \
1244STMT_START { \
1245 while (s <= e) { \
1246 if ( (CoNd) \
fac1af77 1247 && (ln == 1 || folder(s, pat_string, ln)) \
9a5a5549 1248 && (!reginfo || regtry(reginfo, &s)) ) \
4cadc6a9
YO
1249 goto got_it; \
1250 s++; \
1251 } \
1252} STMT_END
1253
1254#define REXEC_FBC_UTF8_SCAN(CoDe) \
1255STMT_START { \
1256 while (s + (uskip = UTF8SKIP(s)) <= strend) { \
1257 CoDe \
1258 s += uskip; \
1259 } \
1260} STMT_END
1261
1262#define REXEC_FBC_SCAN(CoDe) \
1263STMT_START { \
1264 while (s < strend) { \
1265 CoDe \
1266 s++; \
1267 } \
1268} STMT_END
1269
1270#define REXEC_FBC_UTF8_CLASS_SCAN(CoNd) \
1271REXEC_FBC_UTF8_SCAN( \
1272 if (CoNd) { \
24b23f37 1273 if (tmp && (!reginfo || regtry(reginfo, &s))) \
4cadc6a9
YO
1274 goto got_it; \
1275 else \
1276 tmp = doevery; \
1277 } \
1278 else \
1279 tmp = 1; \
1280)
1281
1282#define REXEC_FBC_CLASS_SCAN(CoNd) \
1283REXEC_FBC_SCAN( \
1284 if (CoNd) { \
24b23f37 1285 if (tmp && (!reginfo || regtry(reginfo, &s))) \
4cadc6a9
YO
1286 goto got_it; \
1287 else \
1288 tmp = doevery; \
1289 } \
1290 else \
1291 tmp = 1; \
1292)
1293
1294#define REXEC_FBC_TRYIT \
24b23f37 1295if ((!reginfo || regtry(reginfo, &s))) \
4cadc6a9
YO
1296 goto got_it
1297
e1d1eefb 1298#define REXEC_FBC_CSCAN(CoNdUtF8,CoNd) \
f2ed9b32 1299 if (utf8_target) { \
e1d1eefb
YO
1300 REXEC_FBC_UTF8_CLASS_SCAN(CoNdUtF8); \
1301 } \
1302 else { \
1303 REXEC_FBC_CLASS_SCAN(CoNd); \
d981ef24 1304 }
e1d1eefb 1305
4cadc6a9 1306#define REXEC_FBC_CSCAN_PRELOAD(UtFpReLoAd,CoNdUtF8,CoNd) \
f2ed9b32 1307 if (utf8_target) { \
4cadc6a9
YO
1308 UtFpReLoAd; \
1309 REXEC_FBC_UTF8_CLASS_SCAN(CoNdUtF8); \
1310 } \
1311 else { \
1312 REXEC_FBC_CLASS_SCAN(CoNd); \
d981ef24 1313 }
4cadc6a9
YO
1314
1315#define REXEC_FBC_CSCAN_TAINT(CoNdUtF8,CoNd) \
1316 PL_reg_flags |= RF_tainted; \
f2ed9b32 1317 if (utf8_target) { \
4cadc6a9
YO
1318 REXEC_FBC_UTF8_CLASS_SCAN(CoNdUtF8); \
1319 } \
1320 else { \
1321 REXEC_FBC_CLASS_SCAN(CoNd); \
d981ef24 1322 }
4cadc6a9 1323
786e8c11
YO
1324#define DUMP_EXEC_POS(li,s,doutf8) \
1325 dump_exec_pos(li,s,(PL_regeol),(PL_bostr),(PL_reg_starttry),doutf8)
1326
cfaf538b
KW
1327
1328#define UTF8_NOLOAD(TEST_NON_UTF8, IF_SUCCESS, IF_FAIL) \
1329 tmp = (s != PL_bostr) ? UCHARAT(s - 1) : '\n'; \
1330 tmp = TEST_NON_UTF8(tmp); \
1331 REXEC_FBC_UTF8_SCAN( \
1332 if (tmp == ! TEST_NON_UTF8((U8) *s)) { \
1333 tmp = !tmp; \
1334 IF_SUCCESS; \
1335 } \
1336 else { \
1337 IF_FAIL; \
1338 } \
1339 ); \
1340
1341#define UTF8_LOAD(TeSt1_UtF8, TeSt2_UtF8, IF_SUCCESS, IF_FAIL) \
1342 if (s == PL_bostr) { \
1343 tmp = '\n'; \
1344 } \
1345 else { \
1346 U8 * const r = reghop3((U8*)s, -1, (U8*)PL_bostr); \
1347 tmp = utf8n_to_uvchr(r, UTF8SKIP(r), 0, UTF8_ALLOW_DEFAULT); \
1348 } \
1349 tmp = TeSt1_UtF8; \
1350 LOAD_UTF8_CHARCLASS_ALNUM(); \
1351 REXEC_FBC_UTF8_SCAN( \
1352 if (tmp == ! (TeSt2_UtF8)) { \
1353 tmp = !tmp; \
1354 IF_SUCCESS; \
1355 } \
1356 else { \
1357 IF_FAIL; \
1358 } \
1359 ); \
1360
63ac0dad
KW
1361/* The only difference between the BOUND and NBOUND cases is that
1362 * REXEC_FBC_TRYIT is called when matched in BOUND, and when non-matched in
1363 * NBOUND. This is accomplished by passing it in either the if or else clause,
1364 * with the other one being empty */
1365#define FBC_BOUND(TEST_NON_UTF8, TEST1_UTF8, TEST2_UTF8) \
1dcf4a1b 1366 FBC_BOUND_COMMON(UTF8_LOAD(TEST1_UTF8, TEST2_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER), TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER)
cfaf538b
KW
1367
1368#define FBC_BOUND_NOLOAD(TEST_NON_UTF8, TEST1_UTF8, TEST2_UTF8) \
1dcf4a1b 1369 FBC_BOUND_COMMON(UTF8_NOLOAD(TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER), TEST_NON_UTF8, REXEC_FBC_TRYIT, PLACEHOLDER)
63ac0dad
KW
1370
1371#define FBC_NBOUND(TEST_NON_UTF8, TEST1_UTF8, TEST2_UTF8) \
1dcf4a1b 1372 FBC_BOUND_COMMON(UTF8_LOAD(TEST1_UTF8, TEST2_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT), TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT)
cfaf538b
KW
1373
1374#define FBC_NBOUND_NOLOAD(TEST_NON_UTF8, TEST1_UTF8, TEST2_UTF8) \
1dcf4a1b 1375 FBC_BOUND_COMMON(UTF8_NOLOAD(TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT), TEST_NON_UTF8, PLACEHOLDER, REXEC_FBC_TRYIT)
cfaf538b 1376
63ac0dad
KW
1377
1378/* Common to the BOUND and NBOUND cases. Unfortunately the UTF8 tests need to
1379 * be passed in completely with the variable name being tested, which isn't
1380 * such a clean interface, but this is easier to read than it was before. We
1381 * are looking for the boundary (or non-boundary between a word and non-word
1382 * character. The utf8 and non-utf8 cases have the same logic, but the details
1383 * must be different. Find the "wordness" of the character just prior to this
1384 * one, and compare it with the wordness of this one. If they differ, we have
1385 * a boundary. At the beginning of the string, pretend that the previous
1386 * character was a new-line */
cfaf538b 1387#define FBC_BOUND_COMMON(UTF8_CODE, TEST_NON_UTF8, IF_SUCCESS, IF_FAIL) \
63ac0dad 1388 if (utf8_target) { \
cfaf538b 1389 UTF8_CODE \
63ac0dad
KW
1390 } \
1391 else { /* Not utf8 */ \
1392 tmp = (s != PL_bostr) ? UCHARAT(s - 1) : '\n'; \
1393 tmp = TEST_NON_UTF8(tmp); \
1394 REXEC_FBC_SCAN( \
1395 if (tmp == ! TEST_NON_UTF8((U8) *s)) { \
1396 tmp = !tmp; \
1397 IF_SUCCESS; \
1398 } \
1399 else { \
1400 IF_FAIL; \
1401 } \
1402 ); \
1403 } \
1404 if ((!prog->minlen && tmp) && (!reginfo || regtry(reginfo, &s))) \
1405 goto got_it;
1406
786e8c11
YO
1407/* We know what class REx starts with. Try to find this position... */
1408/* if reginfo is NULL, its a dryrun */
1409/* annoyingly all the vars in this routine have different names from their counterparts
1410 in regmatch. /grrr */
1411
3c3eec57 1412STATIC char *
07be1b83 1413S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s,
24b23f37 1414 const char *strend, regmatch_info *reginfo)
a687059c 1415{
27da23d5 1416 dVAR;
bbe252da 1417 const I32 doevery = (prog->intflags & PREGf_SKIP) == 0;
fac1af77
KW
1418 char *pat_string; /* The pattern's exactish string */
1419 char *pat_end; /* ptr to end char of pat_string */
1420 re_fold_t folder; /* Function for computing non-utf8 folds */
1421 const U8 *fold_array; /* array for folding ords < 256 */
d8093b23 1422 STRLEN ln;
5dab1207 1423 STRLEN lnc;
078c425b 1424 register STRLEN uskip;
fac1af77
KW
1425 U8 c1;
1426 U8 c2;
6eb5f6b9
JH
1427 char *e;
1428 register I32 tmp = 1; /* Scratch variable? */
f2ed9b32 1429 register const bool utf8_target = PL_reg_match_utf8;
453bfd44 1430 UV utf8_fold_flags = 0;
f8fc2ecf 1431 RXi_GET_DECL(prog,progi);
7918f24d
NC
1432
1433 PERL_ARGS_ASSERT_FIND_BYCLASS;
f8fc2ecf 1434
6eb5f6b9
JH
1435 /* We know what class it must start with. */
1436 switch (OP(c)) {
f56b6394 1437 case ANYOFV:
6eb5f6b9 1438 case ANYOF:
f56b6394 1439 if (utf8_target || OP(c) == ANYOFV) {
b1e3e569
KW
1440 STRLEN inclasslen = strend - s;
1441 REXEC_FBC_UTF8_CLASS_SCAN(
1442 reginclass(prog, c, (U8*)s, &inclasslen, utf8_target));
388cc4de
HS
1443 }
1444 else {
6ef69d56 1445 REXEC_FBC_CLASS_SCAN(REGINCLASS(prog, c, (U8*)s));
a0d0e21e 1446 }
6eb5f6b9 1447 break;
f33976b4 1448 case CANY:
4cadc6a9 1449 REXEC_FBC_SCAN(
24b23f37 1450 if (tmp && (!reginfo || regtry(reginfo, &s)))
f33976b4
DB
1451 goto got_it;
1452 else
1453 tmp = doevery;
4cadc6a9 1454 );
f33976b4 1455 break;
2f7f8cb1
KW
1456
1457 case EXACTFA:
1458 if (UTF_PATTERN || utf8_target) {
1459 utf8_fold_flags = FOLDEQ_UTF8_NOMIX_ASCII;
1460 goto do_exactf_utf8;
1461 }
1462 fold_array = PL_fold_latin1; /* Latin1 folds are not affected by */
1463 folder = foldEQ_latin1; /* /a, except the sharp s one which */
1464 goto do_exactf_non_utf8; /* isn't dealt with by these */
1465
6eb5f6b9 1466 case EXACTF:
fac1af77
KW
1467 if (UTF_PATTERN || utf8_target) {
1468 utf8_fold_flags = 0;
1469 goto do_exactf_utf8;
1470 }
1471 fold_array = PL_fold;
1472 folder = foldEQ;
1473 goto do_exactf_non_utf8;
1474
1475 case EXACTFL:
1476 if (UTF_PATTERN || utf8_target) {
17580e7a 1477 utf8_fold_flags = FOLDEQ_UTF8_LOCALE;
fac1af77
KW
1478 goto do_exactf_utf8;
1479 }
1480 fold_array = PL_fold_locale;
1481 folder = foldEQ_locale;
16d951b7
KW
1482 goto do_exactf_non_utf8;
1483
1484 case EXACTFU:
1485 if (UTF_PATTERN || utf8_target) {
1486 utf8_fold_flags = 0;
1487 goto do_exactf_utf8;
1488 }
1489
1490 /* Any 'ss' in the pattern should have been replaced by regcomp,
1491 * so we don't have to worry here about this single special case
1492 * in the Latin1 range */
1493 fold_array = PL_fold_latin1;
1494 folder = foldEQ_latin1;
fac1af77
KW
1495
1496 /* FALL THROUGH */
1497
1498 do_exactf_non_utf8: /* Neither pattern nor string are UTF8 */
1499
1500 /* The idea in the non-utf8 EXACTF* cases is to first find the
1501 * first character of the EXACTF* node and then, if necessary,
1502 * case-insensitively compare the full text of the node. c1 is the
1503 * first character. c2 is its fold. This logic will not work for
1504 * Unicode semantics and the german sharp ss, which hence should
1505 * not be compiled into a node that gets here. */
1506 pat_string = STRING(c);
1507 ln = STR_LEN(c); /* length to match in octets/bytes */
1508
8a90a8fe
KW
1509 /* We know that we have to match at least 'ln' bytes (which is the
1510 * same as characters, since not utf8). If we have to match 3
1511 * characters, and there are only 2 availabe, we know without
1512 * trying that it will fail; so don't start a match past the
1513 * required minimum number from the far end */
fac1af77
KW
1514 e = HOP3c(strend, -((I32)ln), s);
1515
1516 if (!reginfo && e < s) {
1517 e = s; /* Due to minlen logic of intuit() */
1518 }
1519
1520 c1 = *pat_string;
1521 c2 = fold_array[c1];
1522 if (c1 == c2) { /* If char and fold are the same */
1523 REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1);
1524 }
1525 else {
1526 REXEC_FBC_EXACTISH_SCAN(*(U8*)s == c1 || *(U8*)s == c2);
1527 }
1528 break;
1529
1530 do_exactf_utf8:
1531
1532 /* If one of the operands is in utf8, we can't use the simpler
1533 * folding above, due to the fact that many different characters
1534 * can have the same fold, or portion of a fold, or different-
1535 * length fold */
1536 pat_string = STRING(c);
1537 ln = STR_LEN(c); /* length to match in octets/bytes */
1538 pat_end = pat_string + ln;
1539 lnc = (UTF_PATTERN) /* length to match in characters */
1540 ? utf8_length((U8 *) pat_string, (U8 *) pat_end)
1541 : ln;
1542
7c1b9f38
KW
1543 /* Set the end position to the final character available */
1544 e = HOP3c(strend, -1, s);
fac1af77
KW
1545
1546 if (!reginfo && e < s) {
1547 e = s; /* Due to minlen logic of intuit() */
1548 }
1549
1550 while (s <= e) {
1551 char *my_strend= (char *)strend;
1552 if (foldEQ_utf8_flags(s, &my_strend, 0, utf8_target,
1553 pat_string, NULL, ln, cBOOL(UTF_PATTERN), utf8_fold_flags)
1554 && (!reginfo || regtry(reginfo, &s)) )
1555 {
1556 goto got_it;
1557 }
1558 s += UTF8SKIP(s);
1559 }
1560 break;
bbce6d69 1561 case BOUNDL:
3280af22 1562 PL_reg_flags |= RF_tainted;
63ac0dad
KW
1563 FBC_BOUND(isALNUM_LC,
1564 isALNUM_LC_uvchr(UNI_TO_NATIVE(tmp)),
1565 isALNUM_LC_utf8((U8*)s));
a0ed51b3 1566 break;
bbce6d69 1567 case NBOUNDL:
3280af22 1568 PL_reg_flags |= RF_tainted;
63ac0dad
KW
1569 FBC_NBOUND(isALNUM_LC,
1570 isALNUM_LC_uvchr(UNI_TO_NATIVE(tmp)),
1571 isALNUM_LC_utf8((U8*)s));
1572 break;
1573 case BOUND:
1574 FBC_BOUND(isWORDCHAR,
1575 isALNUM_uni(tmp),
1576 cBOOL(swash_fetch(PL_utf8_alnum, (U8*)s, utf8_target)));
1577 break;
cfaf538b
KW
1578 case BOUNDA:
1579 FBC_BOUND_NOLOAD(isWORDCHAR_A,
1580 isWORDCHAR_A(tmp),
1581 isWORDCHAR_A((U8*)s));
1582 break;
a0d0e21e 1583 case NBOUND:
63ac0dad
KW
1584 FBC_NBOUND(isWORDCHAR,
1585 isALNUM_uni(tmp),
1586 cBOOL(swash_fetch(PL_utf8_alnum, (U8*)s, utf8_target)));
1587 break;
cfaf538b
KW
1588 case NBOUNDA:
1589 FBC_NBOUND_NOLOAD(isWORDCHAR_A,
1590 isWORDCHAR_A(tmp),
1591 isWORDCHAR_A((U8*)s));
1592 break;
63ac0dad
KW
1593 case BOUNDU:
1594 FBC_BOUND(isWORDCHAR_L1,
1595 isALNUM_uni(tmp),
1596 cBOOL(swash_fetch(PL_utf8_alnum, (U8*)s, utf8_target)));
1597 break;
1598 case NBOUNDU:
1599 FBC_NBOUND(isWORDCHAR_L1,
1600 isALNUM_uni(tmp),
1601 cBOOL(swash_fetch(PL_utf8_alnum, (U8*)s, utf8_target)));
a0ed51b3 1602 break;
bbce6d69 1603 case ALNUML:
4cadc6a9
YO
1604 REXEC_FBC_CSCAN_TAINT(
1605 isALNUM_LC_utf8((U8*)s),
1606 isALNUM_LC(*s)
1607 );
6895a8aa 1608 break;
980866de
KW
1609 case ALNUMU:
1610 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1611 LOAD_UTF8_CHARCLASS_ALNUM(),
1612 swash_fetch(PL_utf8_alnum,(U8*)s, utf8_target),
980866de
KW
1613 isWORDCHAR_L1((U8) *s)
1614 );
6895a8aa 1615 break;
980866de
KW
1616 case ALNUM:
1617 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1618 LOAD_UTF8_CHARCLASS_ALNUM(),
1619 swash_fetch(PL_utf8_alnum,(U8*)s, utf8_target),
980866de
KW
1620 isWORDCHAR((U8) *s)
1621 );
6895a8aa 1622 break;
cfaf538b 1623 case ALNUMA:
8e9da4d4
KW
1624 /* Don't need to worry about utf8, as it can match only a single
1625 * byte invariant character */
cfaf538b 1626 REXEC_FBC_CLASS_SCAN( isWORDCHAR_A(*s));
6895a8aa 1627 break;
980866de
KW
1628 case NALNUMU:
1629 REXEC_FBC_CSCAN_PRELOAD(
779d7b58 1630 LOAD_UTF8_CHARCLASS_ALNUM(),
359960d4 1631 !swash_fetch(PL_utf8_alnum,(U8*)s, utf8_target),
980866de
KW
1632 ! isWORDCHAR_L1((U8) *s)
1633 );
6895a8aa 1634 break;
a0d0e21e 1635 case NALNUM:
4cadc6a9 1636 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1637 LOAD_UTF8_CHARCLASS_ALNUM(),
1638 !swash_fetch(PL_utf8_alnum, (U8*)s, utf8_target),
980866de 1639 ! isALNUM(*s)
4cadc6a9 1640 );
6895a8aa 1641 break;
cfaf538b 1642 case NALNUMA:
8e9da4d4
KW
1643 REXEC_FBC_CSCAN(
1644 !isWORDCHAR_A(*s),
1645 !isWORDCHAR_A(*s)
1646 );
1647 break;
bbce6d69 1648 case NALNUML:
4cadc6a9
YO
1649 REXEC_FBC_CSCAN_TAINT(
1650 !isALNUM_LC_utf8((U8*)s),
1651 !isALNUM_LC(*s)
1652 );
6895a8aa 1653 break;
980866de
KW
1654 case SPACEU:
1655 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1656 LOAD_UTF8_CHARCLASS_SPACE(),
1657 *s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, utf8_target),
980866de
KW
1658 isSPACE_L1((U8) *s)
1659 );
6895a8aa 1660 break;
a0d0e21e 1661 case SPACE:
4cadc6a9 1662 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1663 LOAD_UTF8_CHARCLASS_SPACE(),
1664 *s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, utf8_target),
980866de 1665 isSPACE((U8) *s)
4cadc6a9 1666 );
6895a8aa 1667 break;
cfaf538b 1668 case SPACEA:
8e9da4d4
KW
1669 /* Don't need to worry about utf8, as it can match only a single
1670 * byte invariant character */
cfaf538b 1671 REXEC_FBC_CLASS_SCAN( isSPACE_A(*s));
6895a8aa 1672 break;
bbce6d69 1673 case SPACEL:
4cadc6a9 1674 REXEC_FBC_CSCAN_TAINT(
6bbba904 1675 isSPACE_LC_utf8((U8*)s),
4cadc6a9
YO
1676 isSPACE_LC(*s)
1677 );
6895a8aa 1678 break;
980866de
KW
1679 case NSPACEU:
1680 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1681 LOAD_UTF8_CHARCLASS_SPACE(),
1682 !( *s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, utf8_target)),
980866de
KW
1683 ! isSPACE_L1((U8) *s)
1684 );
6895a8aa 1685 break;
a0d0e21e 1686 case NSPACE:
4cadc6a9 1687 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1688 LOAD_UTF8_CHARCLASS_SPACE(),
1689 !(*s == ' ' || swash_fetch(PL_utf8_space,(U8*)s, utf8_target)),
980866de 1690 ! isSPACE((U8) *s)
4cadc6a9 1691 );
6895a8aa 1692 break;
cfaf538b 1693 case NSPACEA:
8e9da4d4
KW
1694 REXEC_FBC_CSCAN(
1695 !isSPACE_A(*s),
1696 !isSPACE_A(*s)
1697 );
1698 break;
bbce6d69 1699 case NSPACEL:
4cadc6a9 1700 REXEC_FBC_CSCAN_TAINT(
6bbba904 1701 !isSPACE_LC_utf8((U8*)s),
4cadc6a9
YO
1702 !isSPACE_LC(*s)
1703 );
6895a8aa 1704 break;
a0d0e21e 1705 case DIGIT:
4cadc6a9 1706 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1707 LOAD_UTF8_CHARCLASS_DIGIT(),
1708 swash_fetch(PL_utf8_digit,(U8*)s, utf8_target),
4cadc6a9
YO
1709 isDIGIT(*s)
1710 );
6895a8aa 1711 break;
cfaf538b 1712 case DIGITA:
8e9da4d4
KW
1713 /* Don't need to worry about utf8, as it can match only a single
1714 * byte invariant character */
cfaf538b 1715 REXEC_FBC_CLASS_SCAN( isDIGIT_A(*s));
6895a8aa 1716 break;
b8c5462f 1717 case DIGITL:
4cadc6a9
YO
1718 REXEC_FBC_CSCAN_TAINT(
1719 isDIGIT_LC_utf8((U8*)s),
1720 isDIGIT_LC(*s)
1721 );
6895a8aa 1722 break;
a0d0e21e 1723 case NDIGIT:
4cadc6a9 1724 REXEC_FBC_CSCAN_PRELOAD(
779d7b58
KW
1725 LOAD_UTF8_CHARCLASS_DIGIT(),
1726 !swash_fetch(PL_utf8_digit,(U8*)s, utf8_target),
4cadc6a9
YO
1727 !isDIGIT(*s)
1728 );
6895a8aa 1729 break;
cfaf538b 1730 case NDIGITA:
8e9da4d4
KW
1731 REXEC_FBC_CSCAN(
1732 !isDIGIT_A(*s),
1733 !isDIGIT_A(*s)
1734 );
1735 break;
b8c5462f 1736 case NDIGITL:
4cadc6a9
YO
1737 REXEC_FBC_CSCAN_TAINT(
1738 !isDIGIT_LC_utf8((U8*)s),
1739 !isDIGIT_LC(*s)
1740 );
6895a8aa 1741 break;
e1d1eefb
YO
1742 case LNBREAK:
1743 REXEC_FBC_CSCAN(
1744 is_LNBREAK_utf8(s),
1745 is_LNBREAK_latin1(s)
1746 );
6895a8aa 1747 break;
e1d1eefb
YO
1748 case VERTWS:
1749 REXEC_FBC_CSCAN(
1750 is_VERTWS_utf8(s),
1751 is_VERTWS_latin1(s)
1752 );
6895a8aa 1753 break;
e1d1eefb
YO
1754 case NVERTWS:
1755 REXEC_FBC_CSCAN(
1756 !is_VERTWS_utf8(s),
1757 !is_VERTWS_latin1(s)
1758 );
6895a8aa 1759 break;
e1d1eefb
YO
1760 case HORIZWS:
1761 REXEC_FBC_CSCAN(
1762 is_HORIZWS_utf8(s),
1763 is_HORIZWS_latin1(s)
1764 );
6895a8aa 1765 break;
e1d1eefb
YO
1766 case NHORIZWS:
1767 REXEC_FBC_CSCAN(
1768 !is_HORIZWS_utf8(s),
1769 !is_HORIZWS_latin1(s)
1770 );
6895a8aa 1771 break;
1de06328
YO
1772 case AHOCORASICKC:
1773 case AHOCORASICK:
07be1b83 1774 {
a0a388a1 1775 DECL_TRIE_TYPE(c);
07be1b83
YO
1776 /* what trie are we using right now */
1777 reg_ac_data *aho
f8fc2ecf 1778 = (reg_ac_data*)progi->data->data[ ARG( c ) ];
3251b653
NC
1779 reg_trie_data *trie
1780 = (reg_trie_data*)progi->data->data[ aho->trie ];
85fbaab2 1781 HV *widecharmap = MUTABLE_HV(progi->data->data[ aho->trie + 1 ]);
07be1b83
YO
1782
1783 const char *last_start = strend - trie->minlen;
6148ee25 1784#ifdef DEBUGGING
07be1b83 1785 const char *real_start = s;
6148ee25 1786#endif
07be1b83 1787 STRLEN maxlen = trie->maxlen;
be8e71aa
YO
1788 SV *sv_points;
1789 U8 **points; /* map of where we were in the input string
786e8c11 1790 when reading a given char. For ASCII this
be8e71aa 1791 is unnecessary overhead as the relationship
38a44b82
NC
1792 is always 1:1, but for Unicode, especially
1793 case folded Unicode this is not true. */
f9e705e8 1794 U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
786e8c11
YO
1795 U8 *bitmap=NULL;
1796
07be1b83
YO
1797
1798 GET_RE_DEBUG_FLAGS_DECL;
1799
be8e71aa
YO
1800 /* We can't just allocate points here. We need to wrap it in
1801 * an SV so it gets freed properly if there is a croak while
1802 * running the match */
1803 ENTER;
1804 SAVETMPS;
1805 sv_points=newSV(maxlen * sizeof(U8 *));
1806 SvCUR_set(sv_points,
1807 maxlen * sizeof(U8 *));
1808 SvPOK_on(sv_points);
1809 sv_2mortal(sv_points);
1810 points=(U8**)SvPV_nolen(sv_points );
1de06328
YO
1811 if ( trie_type != trie_utf8_fold
1812 && (trie->bitmap || OP(c)==AHOCORASICKC) )
1813 {
786e8c11
YO
1814 if (trie->bitmap)
1815 bitmap=(U8*)trie->bitmap;
1816 else
1817 bitmap=(U8*)ANYOF_BITMAP(c);
07be1b83 1818 }
786e8c11
YO
1819 /* this is the Aho-Corasick algorithm modified a touch
1820 to include special handling for long "unknown char"
1821 sequences. The basic idea being that we use AC as long
1822 as we are dealing with a possible matching char, when
1823 we encounter an unknown char (and we have not encountered
1824 an accepting state) we scan forward until we find a legal
1825 starting char.
1826 AC matching is basically that of trie matching, except
1827 that when we encounter a failing transition, we fall back
1828 to the current states "fail state", and try the current char
1829 again, a process we repeat until we reach the root state,
1830 state 1, or a legal transition. If we fail on the root state
1831 then we can either terminate if we have reached an accepting
1832 state previously, or restart the entire process from the beginning
1833 if we have not.
1834
1835 */
07be1b83
YO
1836 while (s <= last_start) {
1837 const U32 uniflags = UTF8_ALLOW_DEFAULT;
1838 U8 *uc = (U8*)s;
1839 U16 charid = 0;
1840 U32 base = 1;
1841 U32 state = 1;
1842 UV uvc = 0;
1843 STRLEN len = 0;
1844 STRLEN foldlen = 0;
1845 U8 *uscan = (U8*)NULL;
1846 U8 *leftmost = NULL;
786e8c11
YO
1847#ifdef DEBUGGING
1848 U32 accepted_word= 0;
1849#endif
07be1b83
YO
1850 U32 pointpos = 0;
1851
1852 while ( state && uc <= (U8*)strend ) {
1853 int failed=0;
786e8c11
YO
1854 U32 word = aho->states[ state ].wordnum;
1855
1de06328
YO
1856 if( state==1 ) {
1857 if ( bitmap ) {
1858 DEBUG_TRIE_EXECUTE_r(
1859 if ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
1860 dump_exec_pos( (char *)uc, c, strend, real_start,
f2ed9b32 1861 (char *)uc, utf8_target );
1de06328
YO
1862 PerlIO_printf( Perl_debug_log,
1863 " Scanning for legal start char...\n");
1864 }
d085b490
YO
1865 );
1866 if (utf8_target) {
1867 while ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
1868 uc += UTF8SKIP(uc);
1869 }
1870 } else {
1871 while ( uc <= (U8*)last_start && !BITMAP_TEST(bitmap,*uc) ) {
1872 uc++;
1873 }
1874 }
1de06328 1875 s= (char *)uc;
786e8c11 1876 }
786e8c11
YO
1877 if (uc >(U8*)last_start) break;
1878 }
1879
1880 if ( word ) {
2e64971a 1881 U8 *lpos= points[ (pointpos - trie->wordinfo[word].len) % maxlen ];
786e8c11
YO
1882 if (!leftmost || lpos < leftmost) {
1883 DEBUG_r(accepted_word=word);
07be1b83 1884 leftmost= lpos;
786e8c11 1885 }
07be1b83 1886 if (base==0) break;
786e8c11 1887
07be1b83
YO
1888 }
1889 points[pointpos++ % maxlen]= uc;
55eed653
NC
1890 REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc,
1891 uscan, len, uvc, charid, foldlen,
1892 foldbuf, uniflags);
786e8c11
YO
1893 DEBUG_TRIE_EXECUTE_r({
1894 dump_exec_pos( (char *)uc, c, strend, real_start,
f2ed9b32 1895 s, utf8_target );
07be1b83 1896 PerlIO_printf(Perl_debug_log,
786e8c11
YO
1897 " Charid:%3u CP:%4"UVxf" ",
1898 charid, uvc);
1899 });
07be1b83
YO
1900
1901 do {
6148ee25 1902#ifdef DEBUGGING
786e8c11 1903 word = aho->states[ state ].wordnum;
6148ee25 1904#endif
07be1b83
YO
1905 base = aho->states[ state ].trans.base;
1906
786e8c11
YO
1907 DEBUG_TRIE_EXECUTE_r({
1908 if (failed)
1909 dump_exec_pos( (char *)uc, c, strend, real_start,
f2ed9b32 1910 s, utf8_target );
07be1b83 1911 PerlIO_printf( Perl_debug_log,
786e8c11
YO
1912 "%sState: %4"UVxf", word=%"UVxf,
1913 failed ? " Fail transition to " : "",
1914 (UV)state, (UV)word);
1915 });
07be1b83
YO
1916 if ( base ) {
1917 U32 tmp;
6dd2be57 1918 I32 offset;
07be1b83 1919 if (charid &&
6dd2be57
DM
1920 ( ((offset = base + charid
1921 - 1 - trie->uniquecharcount)) >= 0)
1922 && ((U32)offset < trie->lasttrans)
1923 && trie->trans[offset].check == state
1924 && (tmp=trie->trans[offset].next))
07be1b83 1925 {
786e8c11
YO
1926 DEBUG_TRIE_EXECUTE_r(
1927 PerlIO_printf( Perl_debug_log," - legal\n"));
07be1b83
YO
1928 state = tmp;
1929 break;
1930 }
1931 else {
786e8c11
YO
1932 DEBUG_TRIE_EXECUTE_r(
1933 PerlIO_printf( Perl_debug_log," - fail\n"));
1934 failed = 1;
1935 state = aho->fail[state];
07be1b83
YO
1936 }
1937 }
1938 else {
1939 /* we must be accepting here */
786e8c11
YO
1940 DEBUG_TRIE_EXECUTE_r(
1941 PerlIO_printf( Perl_debug_log," - accepting\n"));
1942 failed = 1;
07be1b83
YO
1943 break;
1944 }
1945 } while(state);
786e8c11 1946 uc += len;
07be1b83
YO
1947 if (failed) {
1948 if (leftmost)
1949 break;
786e8c11 1950 if (!state) state = 1;
07be1b83
YO
1951 }
1952 }
1953 if ( aho->states[ state ].wordnum ) {
2e64971a 1954 U8 *lpos = points[ (pointpos - trie->wordinfo[aho->states[ state ].wordnum].len) % maxlen ];
786e8c11
YO
1955 if (!leftmost || lpos < leftmost) {
1956 DEBUG_r(accepted_word=aho->states[ state ].wordnum);
07be1b83 1957 leftmost = lpos;
786e8c11 1958 }
07be1b83 1959 }
07be1b83
YO
1960 if (leftmost) {
1961 s = (char*)leftmost;
786e8c11
YO
1962 DEBUG_TRIE_EXECUTE_r({
1963 PerlIO_printf(
70685ca0
JH
1964 Perl_debug_log,"Matches word #%"UVxf" at position %"IVdf". Trying full pattern...\n",
1965 (UV)accepted_word, (IV)(s - real_start)
786e8c11
YO
1966 );
1967 });
24b23f37 1968 if (!reginfo || regtry(reginfo, &s)) {
be8e71aa
YO
1969 FREETMPS;
1970 LEAVE;
07be1b83 1971 goto got_it;
be8e71aa 1972 }
07be1b83 1973 s = HOPc(s,1);
786e8c11
YO
1974 DEBUG_TRIE_EXECUTE_r({
1975 PerlIO_printf( Perl_debug_log,"Pattern failed. Looking for new start point...\n");
1976 });
07be1b83 1977 } else {
786e8c11
YO
1978 DEBUG_TRIE_EXECUTE_r(
1979 PerlIO_printf( Perl_debug_log,"No match.\n"));
07be1b83
YO
1980 break;
1981 }
1982 }
be8e71aa
YO
1983 FREETMPS;
1984 LEAVE;
07be1b83
YO
1985 }
1986 break;
b3c9acc1 1987 default:
3c3eec57
GS
1988 Perl_croak(aTHX_ "panic: unknown regstclass %d", (int)OP(c));
1989 break;
d6a28714 1990 }
6eb5f6b9
JH
1991 return 0;
1992 got_it:
1993 return s;
1994}
1995
fae667d5 1996
6eb5f6b9
JH
1997/*
1998 - regexec_flags - match a regexp against a string
1999 */
2000I32
288b8c02 2001Perl_regexec_flags(pTHX_ REGEXP * const rx, char *stringarg, register char *strend,
6eb5f6b9
JH
2002 char *strbeg, I32 minend, SV *sv, void *data, U32 flags)
2003/* strend: pointer to null at end of string */
2004/* strbeg: real beginning of string */
2005/* minend: end of match must be >=minend after stringarg. */
58e23c8d
YO
2006/* data: May be used for some additional optimizations.
2007 Currently its only used, with a U32 cast, for transmitting
2008 the ganch offset when doing a /g match. This will change */
6eb5f6b9
JH
2009/* nosave: For optimizations. */
2010{
97aff369 2011 dVAR;
288b8c02 2012 struct regexp *const prog = (struct regexp *)SvANY(rx);
24b23f37 2013 /*register*/ char *s;
6eb5f6b9 2014 register regnode *c;
24b23f37 2015 /*register*/ char *startpos = stringarg;
6eb5f6b9
JH
2016 I32 minlen; /* must match at least this many chars */
2017 I32 dontbother = 0; /* how many characters not to try at end */
6eb5f6b9
JH
2018 I32 end_shift = 0; /* Same for the end. */ /* CC */
2019 I32 scream_pos = -1; /* Internal iterator of scream. */
ccac19ea 2020 char *scream_olds = NULL;
f2ed9b32 2021 const bool utf8_target = cBOOL(DO_UTF8(sv));
2757e526 2022 I32 multiline;
f8fc2ecf 2023 RXi_GET_DECL(prog,progi);
3b0527fe 2024 regmatch_info reginfo; /* create some info to pass to regtry etc */
e9105d30 2025 regexp_paren_pair *swap = NULL;
a3621e74
YO
2026 GET_RE_DEBUG_FLAGS_DECL;
2027
7918f24d 2028 PERL_ARGS_ASSERT_REGEXEC_FLAGS;
9d4ba2ae 2029 PERL_UNUSED_ARG(data);
6eb5f6b9
JH
2030
2031 /* Be paranoid... */
2032 if (prog == NULL || startpos == NULL) {
2033 Perl_croak(aTHX_ "NULL regexp parameter");
2034 return 0;
2035 }
2036
bbe252da 2037 multiline = prog->extflags & RXf_PMf_MULTILINE;
288b8c02 2038 reginfo.prog = rx; /* Yes, sorry that this is confusing. */
2757e526 2039
f2ed9b32 2040 RX_MATCH_UTF8_set(rx, utf8_target);
1de06328 2041 DEBUG_EXECUTE_r(
f2ed9b32 2042 debug_start_match(rx, utf8_target, startpos, strend,
1de06328
YO
2043 "Matching");
2044 );
bac06658 2045
6eb5f6b9 2046 minlen = prog->minlen;
1de06328
YO
2047
2048 if (strend - startpos < (minlen+(prog->check_offset_min<0?prog->check_offset_min:0))) {
a3621e74 2049 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log,
a72c7584
JH
2050 "String too short [regexec_flags]...\n"));
2051 goto phooey;
1aa99e6b 2052 }
6eb5f6b9 2053
1de06328 2054
6eb5f6b9 2055 /* Check validity of program. */
f8fc2ecf 2056 if (UCHARAT(progi->program) != REG_MAGIC) {
6eb5f6b9
JH
2057 Perl_croak(aTHX_ "corrupted regexp program");
2058 }
2059
2060 PL_reg_flags = 0;
2061 PL_reg_eval_set = 0;
2062 PL_reg_maxiter = 0;
2063
3c8556c3 2064 if (RX_UTF8(rx))
6eb5f6b9
JH
2065 PL_reg_flags |= RF_utf8;
2066
2067 /* Mark beginning of line for ^ and lookbehind. */
3b0527fe 2068 reginfo.bol = startpos; /* XXX not used ??? */
6eb5f6b9 2069 PL_bostr = strbeg;
3b0527fe 2070 reginfo.sv = sv;
6eb5f6b9
JH
2071
2072 /* Mark end of line for $ (and such) */
2073 PL_regeol = strend;
2074
2075 /* see how far we have to get to not match where we matched before */
3b0527fe 2076 reginfo.till = startpos+minend;
6eb5f6b9 2077
6eb5f6b9
JH
2078 /* If there is a "must appear" string, look for it. */
2079 s = startpos;
2080
bbe252da 2081 if (prog->extflags & RXf_GPOS_SEEN) { /* Need to set reginfo->ganch */
6eb5f6b9 2082 MAGIC *mg;
2c296965 2083 if (flags & REXEC_IGNOREPOS){ /* Means: check only at start */
58e23c8d 2084 reginfo.ganch = startpos + prog->gofs;
2c296965 2085 DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
ed549f2e 2086 "GPOS IGNOREPOS: reginfo.ganch = startpos + %"UVxf"\n",(UV)prog->gofs));
2c296965 2087 } else if (sv && SvTYPE(sv) >= SVt_PVMG
6eb5f6b9 2088 && SvMAGIC(sv)
14befaf4
DM
2089 && (mg = mg_find(sv, PERL_MAGIC_regex_global))
2090 && mg->mg_len >= 0) {
3b0527fe 2091 reginfo.ganch = strbeg + mg->mg_len; /* Defined pos() */
2c296965 2092 DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
ed549f2e 2093 "GPOS MAGIC: reginfo.ganch = strbeg + %"IVdf"\n",(IV)mg->mg_len));
2c296965 2094
bbe252da 2095 if (prog->extflags & RXf_ANCH_GPOS) {
3b0527fe 2096 if (s > reginfo.ganch)
6eb5f6b9 2097 goto phooey;
58e23c8d 2098 s = reginfo.ganch - prog->gofs;
2c296965 2099 DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
ed549f2e 2100 "GPOS ANCH_GPOS: s = ganch - %"UVxf"\n",(UV)prog->gofs));
c584a96e
YO
2101 if (s < strbeg)
2102 goto phooey;
6eb5f6b9
JH
2103 }
2104 }
58e23c8d 2105 else if (data) {
70685ca0 2106 reginfo.ganch = strbeg + PTR2UV(data);
2c296965
YO
2107 DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
2108 "GPOS DATA: reginfo.ganch= strbeg + %"UVxf"\n",PTR2UV(data)));
2109
2110 } else { /* pos() not defined */
3b0527fe 2111 reginfo.ganch = strbeg;
2c296965
YO
2112 DEBUG_GPOS_r(PerlIO_printf(Perl_debug_log,
2113 "GPOS: reginfo.ganch = strbeg\n"));
2114 }
6eb5f6b9 2115 }
288b8c02 2116 if (PL_curpm && (PM_GETRE(PL_curpm) == rx)) {
e9105d30
GG
2117 /* We have to be careful. If the previous successful match
2118 was from this regex we don't want a subsequent partially
2119 successful match to clobber the old results.
2120 So when we detect this possibility we add a swap buffer
2121 to the re, and switch the buffer each match. If we fail
2122 we switch it back, otherwise we leave it swapped.
2123 */
2124 swap = prog->offs;
2125 /* do we need a save destructor here for eval dies? */
2126 Newxz(prog->offs, (prog->nparens + 1), regexp_paren_pair);
c74340f9 2127 }
a0714e2c 2128 if (!(flags & REXEC_CHECKED) && (prog->check_substr != NULL || prog->check_utf8 != NULL)) {
6eb5f6b9
JH
2129 re_scream_pos_data d;
2130
2131 d.scream_olds = &scream_olds;
2132 d.scream_pos = &scream_pos;
288b8c02 2133 s = re_intuit_start(rx, sv, s, strend, flags, &d);
3fa9c3d7 2134 if (!s) {
a3621e74 2135 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Not present...\n"));
6eb5f6b9 2136 goto phooey; /* not present */
3fa9c3d7 2137 }
6eb5f6b9
JH
2138 }
2139
1de06328 2140
6eb5f6b9
JH
2141
2142 /* Simplest case: anchored match need be tried only once. */
2143 /* [unless only anchor is BOL and multiline is set] */
bbe252da 2144 if (prog->extflags & (RXf_ANCH & ~RXf_ANCH_GPOS)) {
24b23f37 2145 if (s == startpos && regtry(&reginfo, &startpos))
6eb5f6b9 2146 goto got_it;
bbe252da
YO
2147 else if (multiline || (prog->intflags & PREGf_IMPLICIT)
2148 || (prog->extflags & RXf_ANCH_MBOL)) /* XXXX SBOL? */
6eb5f6b9
JH
2149 {
2150 char *end;
2151
2152 if (minlen)
2153 dontbother = minlen - 1;
1aa99e6b 2154 end = HOP3c(strend, -dontbother, strbeg) - 1;
6eb5f6b9 2155 /* for multiline we only have to try after newlines */
33b8afdf 2156 if (prog->check_substr || prog->check_utf8) {
92f3d482
YO
2157 /* because of the goto we can not easily reuse the macros for bifurcating the
2158 unicode/non-unicode match modes here like we do elsewhere - demerphq */
2159 if (utf8_target) {
2160 if (s == startpos)
2161 goto after_try_utf8;
2162 while (1) {
2163 if (regtry(&reginfo, &s)) {
2164 goto got_it;
2165 }
2166 after_try_utf8:
2167 if (s > end) {
2168 goto phooey;
2169 }
2170 if (prog->extflags & RXf_USE_INTUIT) {
2171 s = re_intuit_start(rx, sv, s + UTF8SKIP(s), strend, flags, NULL);
2172 if (!s) {
2173 goto phooey;
2174 }
2175 }
2176 else {
2177 s += UTF8SKIP(s);
2178 }
2179 }
2180 } /* end search for check string in unicode */
2181 else {
2182 if (s == startpos) {
2183 goto after_try_latin;
2184 }
2185 while (1) {
2186 if (regtry(&reginfo, &s)) {
2187 goto got_it;
2188 }
2189 after_try_latin:
2190 if (s > end) {
2191 goto phooey;
2192 }
2193 if (prog->extflags & RXf_USE_INTUIT) {
2194 s = re_intuit_start(rx, sv, s + 1, strend, flags, NULL);
2195 if (!s) {
2196 goto phooey;
2197 }
2198 }
2199 else {
2200 s++;
2201 }
2202 }
2203 } /* end search for check string in latin*/
2204 } /* end search for check string */
2205 else { /* search for newline */
2206 if (s > startpos) {
2207 /*XXX: The s-- is almost definitely wrong here under unicode - demeprhq*/
6eb5f6b9 2208 s--;
92f3d482
YO
2209 }
2210 /* We can use a more efficient search as newlines are the same in unicode as they are in latin */
6eb5f6b9
JH
2211 while (s < end) {
2212 if (*s++ == '\n') { /* don't need PL_utf8skip here */
24b23f37 2213 if (regtry(&reginfo, &s))
6eb5f6b9
JH
2214 goto got_it;
2215 }
92f3d482
YO
2216 }
2217 } /* end search for newline */
2218 } /* end anchored/multiline check string search */
6eb5f6b9 2219 goto phooey;
bbe252da 2220 } else if (RXf_GPOS_CHECK == (prog->extflags & RXf_GPOS_CHECK))
f9f4320a 2221 {
486ec47a 2222 /* the warning about reginfo.ganch being used without initialization
bbe252da 2223 is bogus -- we set it above, when prog->extflags & RXf_GPOS_SEEN
f9f4320a 2224 and we only enter this block when the same bit is set. */
58e23c8d 2225 char *tmp_s = reginfo.ganch - prog->gofs;
c584a96e
YO
2226
2227 if (tmp_s >= strbeg && regtry(&reginfo, &tmp_s))
6eb5f6b9
JH
2228 goto got_it;
2229 goto phooey;
2230 }
2231
2232 /* Messy cases: unanchored match. */
bbe252da 2233 if ((prog->anchored_substr || prog->anchored_utf8) && prog->intflags & PREGf_SKIP) {
6eb5f6b9 2234 /* we have /x+whatever/ */
f2ed9b32 2235 /* it must be a one character string (XXXX Except UTF_PATTERN?) */
33b8afdf 2236 char ch;
bf93d4cc
GS
2237#ifdef DEBUGGING
2238 int did_match = 0;
2239#endif
f2ed9b32
KW
2240 if (!(utf8_target ? prog->anchored_utf8 : prog->anchored_substr))
2241 utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
2242 ch = SvPVX_const(utf8_target ? prog->anchored_utf8 : prog->anchored_substr)[0];
bf93d4cc 2243
f2ed9b32 2244 if (utf8_target) {
4cadc6a9 2245 REXEC_FBC_SCAN(
6eb5f6b9 2246 if (*s == ch) {
a3621e74 2247 DEBUG_EXECUTE_r( did_match = 1 );
24b23f37 2248 if (regtry(&reginfo, &s)) goto got_it;
6eb5f6b9
JH
2249 s += UTF8SKIP(s);
2250 while (s < strend && *s == ch)
2251 s += UTF8SKIP(s);
2252 }
4cadc6a9 2253 );
6eb5f6b9
JH
2254 }
2255 else {
4cadc6a9 2256 REXEC_FBC_SCAN(
6eb5f6b9 2257 if (*s == ch) {
a3621e74 2258 DEBUG_EXECUTE_r( did_match = 1 );
24b23f37 2259 if (regtry(&reginfo, &s)) goto got_it;
6eb5f6b9
JH
2260 s++;
2261 while (s < strend && *s == ch)
2262 s++;
2263 }
4cadc6a9 2264 );
6eb5f6b9 2265 }
a3621e74 2266 DEBUG_EXECUTE_r(if (!did_match)
bf93d4cc 2267 PerlIO_printf(Perl_debug_log,
b7953727
JH
2268 "Did not find anchored character...\n")
2269 );
6eb5f6b9 2270 }
a0714e2c
SS
2271 else if (prog->anchored_substr != NULL
2272 || prog->anchored_utf8 != NULL
2273 || ((prog->float_substr != NULL || prog->float_utf8 != NULL)
33b8afdf
JH
2274 && prog->float_max_offset < strend - s)) {
2275 SV *must;
2276 I32 back_max;
2277 I32 back_min;
2278 char *last;
6eb5f6b9 2279 char *last1; /* Last position checked before */
bf93d4cc
GS
2280#ifdef DEBUGGING
2281 int did_match = 0;
2282#endif
33b8afdf 2283 if (prog->anchored_substr || prog->anchored_utf8) {
f2ed9b32
KW
2284 if (!(utf8_target ? prog->anchored_utf8 : prog->anchored_substr))
2285 utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
2286 must = utf8_target ? prog->anchored_utf8 : prog->anchored_substr;
33b8afdf
JH
2287 back_max = back_min = prog->anchored_offset;
2288 } else {
f2ed9b32
KW
2289 if (!(utf8_target ? prog->float_utf8 : prog->float_substr))
2290 utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
2291 must = utf8_target ? prog->float_utf8 : prog->float_substr;
33b8afdf
JH
2292 back_max = prog->float_max_offset;
2293 back_min = prog->float_min_offset;
2294 }
1de06328
YO
2295
2296
33b8afdf
JH
2297 if (must == &PL_sv_undef)
2298 /* could not downgrade utf8 check substring, so must fail */
2299 goto phooey;
2300
1de06328
YO
2301 if (back_min<0) {
2302 last = strend;
2303 } else {
2304 last = HOP3c(strend, /* Cannot start after this */
2305 -(I32)(CHR_SVLEN(must)
2306 - (SvTAIL(must) != 0) + back_min), strbeg);
2307 }
6eb5f6b9
JH
2308 if (s > PL_bostr)
2309 last1 = HOPc(s, -1);
2310 else
2311 last1 = s - 1; /* bogus */
2312
a0288114 2313 /* XXXX check_substr already used to find "s", can optimize if
6eb5f6b9
JH
2314 check_substr==must. */
2315 scream_pos = -1;
2316 dontbother = end_shift;
2317 strend = HOPc(strend, -dontbother);
2318 while ( (s <= last) &&
f1905e1b 2319 ((flags & REXEC_SCREAM) && SvSCREAM(sv)
1de06328 2320 ? (s = screaminstr(sv, must, HOP3c(s, back_min, (back_min<0 ? strbeg : strend)) - strbeg,
6eb5f6b9 2321 end_shift, &scream_pos, 0))
1de06328 2322 : (s = fbm_instr((unsigned char*)HOP3(s, back_min, (back_min<0 ? strbeg : strend)),
9041c2e3 2323 (unsigned char*)strend, must,
7fba1cd6 2324 multiline ? FBMrf_MULTILINE : 0))) ) {
4addbd3b 2325 /* we may be pointing at the wrong string */
07bc277f 2326 if ((flags & REXEC_SCREAM) && RXp_MATCH_COPIED(prog))
3f7c398e 2327 s = strbeg + (s - SvPVX_const(sv));
a3621e74 2328 DEBUG_EXECUTE_r( did_match = 1 );
6eb5f6b9
JH
2329 if (HOPc(s, -back_max) > last1) {
2330 last1 = HOPc(s, -back_min);
2331 s = HOPc(s, -back_max);
2332 }
2333 else {
52657f30 2334 char * const t = (last1 >= PL_bostr) ? HOPc(last1, 1) : last1 + 1;
6eb5f6b9
JH
2335
2336 last1 = HOPc(s, -back_min);
52657f30 2337 s = t;
6eb5f6b9 2338 }
f2ed9b32 2339 if (utf8_target) {
6eb5f6b9 2340 while (s <= last1) {
24b23f37 2341 if (regtry(&reginfo, &s))
6eb5f6b9
JH
2342 goto got_it;
2343 s += UTF8SKIP(s);
2344 }
2345 }
2346 else {
2347 while (s <= last1) {
24b23f37 2348 if (regtry(&reginfo, &s))
6eb5f6b9
JH
2349 goto got_it;
2350 s++;
2351 }
2352 }
2353 }
ab3bbdeb 2354 DEBUG_EXECUTE_r(if (!did_match) {
f2ed9b32 2355 RE_PV_QUOTED_DECL(quoted, utf8_target, PERL_DEBUG_PAD_ZERO(0),
ab3bbdeb
YO
2356 SvPVX_const(must), RE_SV_DUMPLEN(must), 30);
2357 PerlIO_printf(Perl_debug_log, "Did not find %s substr %s%s...\n",
33b8afdf 2358 ((must == prog->anchored_substr || must == prog->anchored_utf8)
bf93d4cc 2359 ? "anchored" : "floating"),
ab3bbdeb
YO
2360 quoted, RE_SV_TAIL(must));
2361 });
6eb5f6b9
JH
2362 goto phooey;
2363 }
f8fc2ecf 2364 else if ( (c = progi->regstclass) ) {
f14c76ed 2365 if (minlen) {
f8fc2ecf 2366 const OPCODE op = OP(progi->regstclass);
66e933ab 2367 /* don't bother with what can't match */
786e8c11 2368 if (PL_regkind[op] != EXACT && op != CANY && PL_regkind[op] != TRIE)
f14c76ed
RGS
2369 strend = HOPc(strend, -(minlen - 1));
2370 }
a3621e74 2371 DEBUG_EXECUTE_r({
be8e71aa 2372 SV * const prop = sv_newmortal();
32fc9b6a 2373 regprop(prog, prop, c);
0df25f3d 2374 {
f2ed9b32 2375 RE_PV_QUOTED_DECL(quoted,utf8_target,PERL_DEBUG_PAD_ZERO(1),
ab3bbdeb 2376 s,strend-s,60);
0df25f3d 2377 PerlIO_printf(Perl_debug_log,
1c8f8eb1 2378 "Matching stclass %.*s against %s (%d bytes)\n",
e4f74956 2379 (int)SvCUR(prop), SvPVX_const(prop),
ab3bbdeb 2380 quoted, (int)(strend - s));
0df25f3d 2381 }
ffc61ed2 2382 });
3b0527fe 2383 if (find_byclass(prog, c, s, strend, &reginfo))
6eb5f6b9 2384 goto got_it;
07be1b83 2385 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "Contradicts stclass... [regexec_flags]\n"));
d6a28714
JH
2386 }
2387 else {
2388 dontbother = 0;
a0714e2c 2389 if (prog->float_substr != NULL || prog->float_utf8 != NULL) {
33b8afdf 2390 /* Trim the end. */
d6a28714 2391 char *last;
33b8afdf
JH
2392 SV* float_real;
2393
f2ed9b32
KW
2394 if (!(utf8_target ? prog->float_utf8 : prog->float_substr))
2395 utf8_target ? to_utf8_substr(prog) : to_byte_substr(prog);
2396 float_real = utf8_target ? prog->float_utf8 : prog->float_substr;
d6a28714 2397
f1905e1b 2398 if ((flags & REXEC_SCREAM) && SvSCREAM(sv)) {
33b8afdf 2399 last = screaminstr(sv, float_real, s - strbeg,
d6a28714
JH
2400 end_shift, &scream_pos, 1); /* last one */
2401 if (!last)
ffc61ed2 2402 last = scream_olds; /* Only one occurrence. */
4addbd3b 2403 /* we may be pointing at the wrong string */
07bc277f 2404 else if (RXp_MATCH_COPIED(prog))
3f7c398e 2405 s = strbeg + (s - SvPVX_const(sv));
b8c5462f 2406 }
d6a28714
JH
2407 else {
2408 STRLEN len;
cfd0369c 2409 const char * const little = SvPV_const(float_real, len);
d6a28714 2410
33b8afdf 2411 if (SvTAIL(float_real)) {
d6a28714
JH
2412 if (memEQ(strend - len + 1, little, len - 1))
2413 last = strend - len + 1;
7fba1cd6 2414 else if (!multiline)
9041c2e3 2415 last = memEQ(strend - len, little, len)
bd61b366 2416 ? strend - len : NULL;
b8c5462f 2417 else
d6a28714
JH
2418 goto find_last;
2419 } else {
2420 find_last:
9041c2e3 2421 if (len)
d6a28714 2422 last = rninstr(s, strend, little, little + len);
b8c5462f 2423 else
a0288114 2424 last = strend; /* matching "$" */
b8c5462f 2425 }
b8c5462f 2426 }
bf93d4cc 2427 if (last == NULL) {
6bda09f9
YO
2428 DEBUG_EXECUTE_r(
2429 PerlIO_printf(Perl_debug_log,
2430 "%sCan't trim the tail, match fails (should not happen)%s\n",
2431 PL_colors[4], PL_colors[5]));
bf93d4cc
GS
2432 goto phooey; /* Should not happen! */
2433 }
d6a28714
JH
2434 dontbother = strend - last + prog->float_min_offset;
2435 }
2436 if (minlen && (dontbother < minlen))
2437 dontbother = minlen - 1;
2438 strend -= dontbother; /* this one's always in bytes! */
2439 /* We don't know much -- general case. */
f2ed9b32 2440 if (utf8_target) {
d6a28714 2441 for (;;) {
24b23f37 2442 if (regtry(&reginfo, &s))
d6a28714
JH
2443 goto got_it;
2444 if (s >= strend)
2445 break;
b8c5462f 2446 s += UTF8SKIP(s);
d6a28714
JH
2447 };
2448 }
2449 else {
2450 do {
24b23f37 2451 if (regtry(&reginfo, &s))
d6a28714
JH
2452 goto got_it;
2453 } while (s++ < strend);
2454 }
2455 }
2456
2457 /* Failure. */
2458 goto phooey;
2459
2460got_it:
e9105d30 2461 Safefree(swap);
288b8c02 2462 RX_MATCH_TAINTED_set(rx, PL_reg_flags & RF_tainted);
d6a28714 2463
19b95bf0 2464 if (PL_reg_eval_set)
4f639d21 2465 restore_pos(aTHX_ prog);
5daac39c
NC
2466 if (RXp_PAREN_NAMES(prog))
2467 (void)hv_iterinit(RXp_PAREN_NAMES(prog));
d6a28714
JH
2468
2469 /* make sure $`, $&, $', and $digit will work later */
2470 if ( !(flags & REXEC_NOT_FIRST) ) {
288b8c02 2471 RX_MATCH_COPY_FREE(rx);
d6a28714 2472 if (flags & REXEC_COPY_STR) {
be8e71aa 2473 const I32 i = PL_regeol - startpos + (stringarg - strbeg);
f8c7b90f 2474#ifdef PERL_OLD_COPY_ON_WRITE
ed252734
NC
2475 if ((SvIsCOW(sv)
2476 || (SvFLAGS(sv) & CAN_COW_MASK) == CAN_COW_FLAGS)) {
2477 if (DEBUG_C_TEST) {
2478 PerlIO_printf(Perl_debug_log,
2479 "Copy on write: regexp capture, type %d\n",
2480 (int) SvTYPE(sv));
2481 }
2482 prog->saved_copy = sv_setsv_cow(prog->saved_copy, sv);
d5263905 2483 prog->subbeg = (char *)SvPVX_const(prog->saved_copy);
ed252734
NC
2484 assert (SvPOKp(prog->saved_copy));
2485 } else
2486#endif
2487 {
288b8c02 2488 RX_MATCH_COPIED_on(rx);
ed252734
NC
2489 s = savepvn(strbeg, i);
2490 prog->subbeg = s;
2491 }
d6a28714 2492 prog->sublen = i;
d6a28714
JH
2493 }
2494 else {
2495 prog->subbeg = strbeg;
2496 prog->sublen = PL_regeol - strbeg; /* strend may have been modified */
2497 }
2498 }
9041c2e3 2499
d6a28714
JH
2500 return 1;
2501
2502phooey:
a3621e74 2503 DEBUG_EXECUTE_r(PerlIO_printf(Perl_debug_log, "%sMatch failed%s\n",
e4584336 2504 PL_colors[4], PL_colors[5]));
d6a28714 2505 if (PL_reg_eval_set)
4f639d21 2506 restore_pos(aTHX_ prog);
e9105d30 2507 if (swap) {
c74340f9 2508 /* we failed :-( roll it back */
e9105d30
GG
2509 Safefree(prog->offs);
2510 prog->offs = swap;
2511 }
2512
d6a28714
JH
2513 return 0;
2514}
2515
6bda09f9 2516
d6a28714
JH
2517/*
2518 - regtry - try match at specific point
2519 */
2520STATIC I32 /* 0 failure, 1 success */
24b23f37 2521S_regtry(pTHX_ regmatch_info *reginfo, char **startpos)
d6a28714 2522{
97aff369 2523 dVAR;
d6a28714 2524 CHECKPOINT lastcp;
288b8c02
NC
2525 REGEXP *const rx = reginfo->prog;
2526 regexp *const prog = (struct regexp *)SvANY(rx);
f8fc2ecf 2527 RXi_GET_DECL(prog,progi);
a3621e74 2528 GET_RE_DEBUG_FLAGS_DECL;
7918f24d
NC
2529
2530 PERL_ARGS_ASSERT_REGTRY;
2531
24b23f37 2532 reginfo->cutpoint=NULL;
d6a28714 2533
bbe252da 2534 if ((prog->extflags & RXf_EVAL_SEEN) && !PL_reg_eval_set) {
d6a28714
JH
2535 MAGIC *mg;
2536
2537 PL_reg_eval_set = RS_init;
a3621e74 2538 DEBUG_EXECUTE_r(DEBUG_s(
b900a521
JH
2539 PerlIO_printf(Perl_debug_log, " setting stack tmpbase at %"IVdf"\n",
2540 (IV)(PL_stack_sp - PL_stack_base));
d6a28714 2541 ));
ea8d6ae1 2542 SAVESTACK_CXPOS();
d6a28714
JH
2543 cxstack[cxstack_ix].blk_oldsp = PL_stack_sp - PL_stack_base;
2544 /* Otherwise OP_NEXTSTATE will free whatever on stack now. */
2545 SAVETMPS;
2546 /* Apparently this is not needed, judging by wantarray. */
e8347627 2547 /* SAVEI8(cxstack[cxstack_ix].blk_gimme);
d6a28714
JH
2548 cxstack[cxstack_ix].blk_gimme = G_SCALAR; */
2549
3b0527fe 2550 if (reginfo->sv) {
d6a28714 2551 /* Make $_ available to executed code. */
3b0527fe 2552 if (reginfo->sv != DEFSV) {
59f00321 2553 SAVE_DEFSV;
414bf5ae 2554 DEFSV_set(reginfo->sv);
b8c5462f 2555 }
d6a28714 2556
3b0527fe
DM
2557 if (!(SvTYPE(reginfo->sv) >= SVt_PVMG && SvMAGIC(reginfo->sv)
2558 && (mg = mg_find(reginfo->sv, PERL_MAGIC_regex_global)))) {
d6a28714 2559 /* prepare for quick setting of pos */
d300d9fa 2560#ifdef PERL_OLD_COPY_ON_WRITE
51a9ea20
NC
2561 if (SvIsCOW(reginfo->sv))
2562 sv_force_normal_flags(reginfo->sv, 0);
d300d9fa 2563#endif
3dab1dad 2564 mg = sv_magicext(reginfo->sv, NULL, PERL_MAGIC_regex_global,
d300d9fa 2565 &PL_vtbl_mglob, NULL, 0);
d6a28714 2566 mg->mg_len = -1;
b8c5462f 2567 }
d6a28714
JH
2568 PL_reg_magic = mg;
2569 PL_reg_oldpos = mg->mg_len;
4f639d21 2570 SAVEDESTRUCTOR_X(restore_pos, prog);
d6a28714 2571 }
09687e5a 2572 if (!PL_reg_curpm) {
a02a5408 2573 Newxz(PL_reg_curpm, 1, PMOP);
09687e5a
AB
2574#ifdef USE_ITHREADS
2575 {
14a49a24 2576 SV* const repointer = &PL_sv_undef;
92313705
NC
2577 /* this regexp is also owned by the new PL_reg_curpm, which
2578 will try to free it. */
d2ece331 2579 av_push(PL_regex_padav, repointer);
09687e5a
AB
2580 PL_reg_curpm->op_pmoffset = av_len(PL_regex_padav);
2581 PL_regex_pad = AvARRAY(PL_regex_padav);
2582 }
2583#endif
2584 }
86c29d75
NC
2585#ifdef USE_ITHREADS
2586 /* It seems that non-ithreads works both with and without this code.
2587 So for efficiency reasons it seems best not to have the code
2588 compiled when it is not needed. */
92313705
NC
2589 /* This is safe against NULLs: */
2590 ReREFCNT_dec(PM_GETRE(PL_reg_curpm));
2591 /* PM_reg_curpm owns a reference to this regexp. */
cd733337 2592 (void)ReREFCNT_inc(rx);
86c29d75 2593#endif
288b8c02 2594 PM_SETRE(PL_reg_curpm, rx);
d6a28714
JH
2595 PL_reg_oldcurpm = PL_curpm;
2596 PL_curpm = PL_reg_curpm;
07bc277f 2597 if (RXp_MATCH_COPIED(prog)) {
d6a28714
JH
2598 /* Here is a serious problem: we cannot rewrite subbeg,
2599 since it may be needed if this match fails. Thus
2600 $` inside (?{}) could fail... */
2601 PL_reg_oldsaved = prog->subbeg;
2602 PL_reg_oldsavedlen = prog->sublen;
f8c7b90f 2603#ifdef PERL_OLD_COPY_ON_WRITE
ed252734
NC
2604 PL_nrs = prog->saved_copy;
2605#endif
07bc277f 2606 RXp_MATCH_COPIED_off(prog);
d6a28714
JH
2607 }
2608 else
bd61b366 2609 PL_reg_oldsaved = NULL;
d6a28714
JH
2610 prog->subbeg = PL_bostr;
2611 prog->sublen = PL_regeol - PL_bostr; /* strend may have been modified */
2612 }
24b23f37 2613 DEBUG_EXECUTE_r(PL_reg_starttry = *startpos);
f0ab9afb 2614 prog->offs[0].start = *startpos - PL_bostr;
24b23f37 2615 PL_reginput = *startpos;
d6a28714 2616 PL_reglastparen = &prog->lastparen;
a01268b5 2617 PL_reglastcloseparen = &prog->lastcloseparen;
d6a28714 2618 prog->lastparen = 0;
03994de8 2619 prog->lastcloseparen = 0;
d6a28714 2620 PL_regsize = 0;
f0ab9afb 2621 PL_regoffs = prog->offs;
d6a28714
JH
2622 if (PL_reg_start_tmpl <= prog->nparens) {
2623 PL_reg_start_tmpl = prog->nparens*3/2 + 3;
2624 if(PL_reg_start_tmp)
2625 Renew(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
2626 else
a02a5408 2627 Newx(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
d6a28714
JH
2628 }
2629
2630 /* XXXX What this code is doing here?!!! There should be no need
2631 to do this again and again, PL_reglastparen should take care of
3dd2943c 2632 this! --ilya*/
dafc8851
JH
2633
2634 /* Tests pat.t#187 and split.t#{13,14} seem to depend on this code.
2635 * Actually, the code in regcppop() (which Ilya may be meaning by
daf18116 2636 * PL_reglastparen), is not needed at all by the test suite
225593e1
DM
2637 * (op/regexp, op/pat, op/split), but that code is needed otherwise
2638 * this erroneously leaves $1 defined: "1" =~ /^(?:(\d)x)?\d$/
2639 * Meanwhile, this code *is* needed for the
daf18116
JH
2640 * above-mentioned test suite tests to succeed. The common theme
2641 * on those tests seems to be returning null fields from matches.
225593e1 2642 * --jhi updated by dapm */
dafc8851 2643#if 1
d6a28714 2644 if (prog->nparens) {
f0ab9afb 2645 regexp_paren_pair *pp = PL_regoffs;
097eb12c 2646 register I32 i;
eb160463 2647 for (i = prog->nparens; i > (I32)*PL_reglastparen; i--) {
f0ab9afb
NC
2648 ++pp;
2649 pp->start = -1;
2650 pp->end = -1;
d6a28714
JH
2651 }
2652 }
dafc8851 2653#endif
02db2b7b 2654 REGCP_SET(lastcp);
f8fc2ecf 2655 if (regmatch(reginfo, progi->program + 1)) {
f0ab9afb 2656 PL_regoffs[0].end = PL_reginput - PL_bostr;
d6a28714
JH
2657 return 1;
2658 }
24b23f37
YO
2659 if (reginfo->cutpoint)
2660 *startpos= reginfo->cutpoint;
02db2b7b 2661 REGCP_UNWIND(lastcp);
d6a28714
JH
2662 return 0;
2663}
2664
02db2b7b 2665
8ba1375e
MJD
2666#define sayYES goto yes
2667#define sayNO goto no
262b90c4 2668#define sayNO_SILENT goto no_silent
8ba1375e 2669
f9f4320a
YO
2670/* we dont use STMT_START/END here because it leads to
2671 "unreachable code" warnings, which are bogus, but distracting. */
2672#define CACHEsayNO \
c476f425
DM
2673 if (ST.cache_mask) \
2674 PL_reg_poscache[ST.cache_offset] |= ST.cache_mask; \
f9f4320a 2675 sayNO
3298f257 2676
a3621e74 2677/* this is used to determine how far from the left messages like
265c4333
YO
2678 'failed...' are printed. It should be set such that messages
2679 are inline with the regop output that created them.
a3621e74 2680*/
265c4333 2681#define REPORT_CODE_OFF 32
a3621e74
YO
2682
2683
40a82448
DM
2684#define CHRTEST_UNINIT -1001 /* c1/c2 haven't been calculated yet */
2685#define CHRTEST_VOID -1000 /* the c1/c2 "next char" test should be skipped */
9e137952 2686
86545054
DM
2687#define SLAB_FIRST(s) (&(s)->states[0])
2688#define SLAB_LAST(s) (&(s)->states[PERL_REGMATCH_SLAB_SLOTS-1])
2689
5d9a96ca
DM
2690/* grab a new slab and return the first slot in it */
2691
2692STATIC regmatch_state *
2693S_push_slab(pTHX)
2694{
a35a87e7 2695#if PERL_VERSION < 9 && !defined(PERL_CORE)
54df2634
NC
2696 dMY_CXT;
2697#endif
5d9a96ca
DM
2698 regmatch_slab *s = PL_regmatch_slab->next;
2699 if (!s) {
2700 Newx(s, 1, regmatch_slab);
2701 s->prev = PL_regmatch_slab;
2702 s->next = NULL;
2703 PL_regmatch_slab->next = s;
2704 }
2705 PL_regmatch_slab = s;
86545054 2706 return SLAB_FIRST(s);
5d9a96ca 2707}
5b47454d 2708
95b24440 2709
40a82448
DM
2710/* push a new state then goto it */
2711
2712#define PUSH_STATE_GOTO(state, node) \
2713 scan = node; \
2714 st->resume_state = state; \
2715 goto push_state;
2716
2717/* push a new state with success backtracking, then goto it */
2718
2719#define PUSH_YES_STATE_GOTO(state, node) \
2720 scan = node; \
2721 st->resume_state = state; \
2722 goto push_yes_state;
2723
aa283a38 2724
aa283a38 2725
d6a28714 2726/*
95b24440 2727
bf1f174e
DM
2728regmatch() - main matching routine
2729
2730This is basically one big switch statement in a loop. We execute an op,
2731set 'next' to point the next op, and continue. If we come to a point which
2732we may need to backtrack to on failure such as (A|B|C), we push a
2733backtrack state onto the backtrack stack. On failure, we pop the top
2734state, and re-enter the loop at the state indicated. If there are no more
2735states to pop, we return failure.
2736
2737Sometimes we also need to backtrack on success; for example /A+/, where
2738after successfully matching one A, we need to go back and try to
2739match another one; similarly for lookahead assertions: if the assertion
2740completes successfully, we backtrack to the state just before the assertion
2741and then carry on. In these cases, the pushed state is marked as
2742'backtrack on success too'. This marking is in fact done by a chain of
2743pointers, each pointing to the previous 'yes' state. On success, we pop to
2744the nearest yes state, discarding any intermediate failure-only states.
2745Sometimes a yes state is pushed just to force some cleanup code to be
2746called at the end of a successful match or submatch; e.g. (??{$re}) uses
2747it to free the inner regex.
2748
2749Note that failure backtracking rewinds the cursor position, while
2750success backtracking leaves it alone.
2751
2752A pattern is complete when the END op is executed, while a subpattern
2753such as (?=foo) is complete when the SUCCESS op is executed. Both of these
2754ops trigger the "pop to last yes state if any, otherwise return true"
2755behaviour.
2756
2757A common convention in this function is to use A and B to refer to the two
2758subpatterns (or to the first nodes thereof) in patterns like /A*B/: so A is
2759the subpattern to be matched possibly multiple times, while B is the entire
2760rest of the pattern. Variable and state names reflect this convention.
2761
2762The states in the main switch are the union of ops and failure/success of
2763substates associated with with that op. For example, IFMATCH is the op
2764that does lookahead assertions /(?=A)B/ and so the IFMATCH state means
2765'execute IFMATCH'; while IFMATCH_A is a state saying that we have just
2766successfully matched A and IFMATCH_A_fail is a state saying that we have
2767just failed to match A. Resume states always come in pairs. The backtrack
2768state we push is marked as 'IFMATCH_A', but when that is popped, we resume
2769at IFMATCH_A or IFMATCH_A_fail, depending on whether we are backtracking
2770on success or failure.
2771
2772The struct that holds a backtracking state is actually a big union, with
2773one variant for each major type of op. The variable st points to the
2774top-most backtrack struct. To make the code clearer, within each
2775block of code we #define ST to alias the relevant union.
2776
2777Here's a concrete example of a (vastly oversimplified) IFMATCH
2778implementation:
2779
2780 switch (state) {
2781 ....
2782
2783#define ST st->u.ifmatch
2784
2785 case IFMATCH: // we are executing the IFMATCH op, (?=A)B
2786 ST.foo = ...; // some state we wish to save
95b24440 2787 ...
bf1f174e
DM
2788 // push a yes backtrack state with a resume value of
2789 // IFMATCH_A/IFMATCH_A_fail, then continue execution at the
2790 // first node of A:
2791 PUSH_YES_STATE_GOTO(IFMATCH_A, A);
2792 // NOTREACHED
2793
2794 case IFMATCH_A: // we have successfully executed A; now continue with B
2795 next = B;
2796 bar = ST.foo; // do something with the preserved value
2797 break;
2798
2799 case IFMATCH_A_fail: // A failed, so the assertion failed
2800 ...; // do some housekeeping, then ...
2801 sayNO; // propagate the failure
2802
2803#undef ST
95b24440 2804
bf1f174e
DM
2805 ...
2806 }
95b24440 2807
bf1f174e
DM
2808For any old-timers reading this who are familiar with the old recursive
2809approach, the code above is equivalent to:
95b24440 2810
bf1f174e
DM
2811 case IFMATCH: // we are executing the IFMATCH op, (?=A)B
2812 {
2813 int foo = ...
95b24440 2814 ...
bf1f174e
DM
2815 if (regmatch(A)) {
2816 next = B;
2817 bar = foo;
2818 break;
95b24440 2819 }
bf1f174e
DM
2820 ...; // do some housekeeping, then ...
2821 sayNO; // propagate the failure
95b24440 2822 }
bf1f174e
DM
2823
2824The topmost backtrack state, pointed to by st, is usually free. If you
2825want to claim it, populate any ST.foo fields in it with values you wish to
2826save, then do one of
2827
2828 PUSH_STATE_GOTO(resume_state, node);
2829 PUSH_YES_STATE_GOTO(resume_state, node);
2830
2831which sets that backtrack state's resume value to 'resume_state', pushes a
2832new free entry to the top of the backtrack stack, then goes to 'node'.
2833On backtracking, the free slot is popped, and the saved state becomes the
2834new free state. An ST.foo field in this new top state can be temporarily
2835accessed to retrieve values, but once the main loop is re-entered, it
2836becomes available for reuse.
2837
2838Note that the depth of the backtrack stack constantly increases during the
2839left-to-right execution of the pattern, rather than going up and down with
2840the pattern nesting. For example the stack is at its maximum at Z at the
2841end of the pattern, rather than at X in the following:
2842
2843 /(((X)+)+)+....(Y)+....Z/
2844
2845The only exceptions to this are lookahead/behind assertions and the cut,
2846(?>A), which pop all the backtrack states associated with A before
2847continuing.
2848
486ec47a 2849Backtrack state structs are allocated in slabs of about 4K in size.
bf1f174e
DM
2850PL_regmatch_state and st always point to the currently active state,
2851and PL_regmatch_slab points to the slab currently containing
2852PL_regmatch_state. The first time regmatch() is called, the first slab is
2853allocated, and is never freed until interpreter destruction. When the slab
2854is full, a new one is allocated and chained to the end. At exit from
2855regmatch(), slabs allocated since entry are freed.
2856
2857*/
95b24440 2858
40a82448 2859
5bc10b2c 2860#define DEBUG_STATE_pp(pp) \
265c4333 2861 DEBUG_STATE_r({ \
f2ed9b32 2862 DUMP_EXEC_POS(locinput, scan, utf8_target); \
5bc10b2c 2863 PerlIO_printf(Perl_debug_log, \
5d458dd8 2864 " %*s"pp" %s%s%s%s%s\n", \
5bc10b2c 2865 depth*2, "", \
13d6edb4 2866 PL_reg_name[st->resume_state], \
5d458dd8
YO
2867 ((st==yes_state||st==mark_state) ? "[" : ""), \
2868 ((st==yes_state) ? "Y" : ""), \
2869 ((st==mark_state) ? "M" : ""), \
2870 ((st==yes_state||st==mark_state) ? "]" : "") \
2871 ); \
265c4333 2872 });
5bc10b2c 2873
40a82448 2874
3dab1dad 2875#define REG_NODE_NUM(x) ((x) ? (int)((x)-prog) : -1)
95b24440 2876
3df15adc 2877#ifdef DEBUGGING
5bc10b2c 2878
ab3bbdeb 2879STATIC void
f2ed9b32 2880S_debug_start_match(pTHX_ const REGEXP *prog, const bool utf8_target,
ab3bbdeb
YO
2881 const char *start, const char *end, const char *blurb)
2882{
efd26800 2883 const bool utf8_pat = RX_UTF8(prog) ? 1 : 0;
7918f24d
NC
2884
2885 PERL_ARGS_ASSERT_DEBUG_START_MATCH;
2886
ab3bbdeb
YO
2887 if (!PL_colorset)
2888 reginitcolors();
2889 {
2890 RE_PV_QUOTED_DECL(s0, utf8_pat, PERL_DEBUG_PAD_ZERO(0),
d2c6dc5e 2891 RX_PRECOMP_const(prog), RX_PRELEN(prog), 60);
ab3bbdeb 2892
f2ed9b32 2893 RE_PV_QUOTED_DECL(s1, utf8_target, PERL_DEBUG_PAD_ZERO(1),
ab3bbdeb
YO
2894 start, end - start, 60);
2895
2896 PerlIO_printf(Perl_debug_log,
2897 "%s%s REx%s %s against %s\n",
2898 PL_colors[4], blurb, PL_colors[5], s0, s1);
2899
f2ed9b32 2900 if (utf8_target||utf8_pat)
1de06328
YO
2901 PerlIO_printf(Perl_debug_log, "UTF-8 %s%s%s...\n",
2902 utf8_pat ? "pattern" : "",
f2ed9b32
KW
2903 utf8_pat && utf8_target ? " and " : "",
2904 utf8_target ? "string" : ""
ab3bbdeb
YO
2905 );
2906 }
2907}
3df15adc
YO
2908
2909STATIC void
786e8c11
YO
2910S_dump_exec_pos(pTHX_ const char *locinput,
2911 const regnode *scan,
2912 const char *loc_regeol,
2913 const char *loc_bostr,
2914 const char *loc_reg_starttry,
f2ed9b32 2915 const bool utf8_target)
07be1b83 2916{
786e8c11 2917 const int docolor = *PL_colors[0] || *PL_colors[2] || *PL_colors[4];
07be1b83 2918 const int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */
786e8c11 2919 int l = (loc_regeol - locinput) > taill ? taill : (loc_regeol - locinput);
07be1b83
YO
2920 /* The part of the string before starttry has one color
2921 (pref0_len chars), between starttry and current
2922 position another one (pref_len - pref0_len chars),
2923 after the current position the third one.
2924 We assume that pref0_len <= pref_len, otherwise we
2925 decrease pref0_len. */
786e8c11
YO
2926 int pref_len = (locinput - loc_bostr) > (5 + taill) - l
2927 ? (5 + taill) - l : locinput - loc_bostr;
07be1b83
YO
2928 int pref0_len;
2929
7918f24d
NC
2930 PERL_ARGS_ASSERT_DUMP_EXEC_POS;
2931
f2ed9b32 2932 while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput - pref_len)))
07be1b83 2933 pref_len++;
786e8c11
YO
2934 pref0_len = pref_len - (locinput - loc_reg_starttry);
2935 if (l + pref_len < (5 + taill) && l < loc_regeol - locinput)
2936 l = ( loc_regeol - locinput > (5 + taill) - pref_len
2937 ? (5 + taill) - pref_len : loc_regeol - locinput);
f2ed9b32 2938 while (utf8_target && UTF8_IS_CONTINUATION(*(U8*)(locinput + l)))
07be1b83
YO
2939 l--;
2940 if (pref0_len < 0)
2941 pref0_len = 0;
2942 if (pref0_len > pref_len)
2943 pref0_len = pref_len;
2944 {
f2ed9b32 2945 const int is_uni = (utf8_target && OP(scan) != CANY) ? 1 : 0;
0df25f3d 2946
ab3bbdeb 2947 RE_PV_COLOR_DECL(s0,len0,is_uni,PERL_DEBUG_PAD(0),
1de06328 2948 (locinput - pref_len),pref0_len, 60, 4, 5);
0df25f3d 2949
ab3bbdeb 2950 RE_PV_COLOR_DECL(s1,len1,is_uni,PERL_DEBUG_PAD(1),
3df15adc 2951 (locinput - pref_len + pref0_len),
1de06328 2952 pref_len - pref0_len, 60, 2, 3);
0df25f3d 2953
ab3bbdeb 2954 RE_PV_COLOR_DECL(s2,len2,is_uni,PERL_DEBUG_PAD(2),
1de06328 2955 locinput, loc_regeol - locinput, 10, 0, 1);
0df25f3d 2956
1de06328 2957 const STRLEN tlen=len0+len1+len2;
3df15adc 2958 PerlIO_printf(Perl_debug_log,
ab3bbdeb 2959 "%4"IVdf" <%.*s%.*s%s%.*s>%*s|",
786e8c11 2960 (IV)(locinput - loc_bostr),
07be1b83 2961 len0, s0,
07be1b83 2962 len1, s1,
07be1b83 2963 (docolor ? "" : "> <"),
07be1b83 2964 len2, s2,
f9f4320a 2965 (int)(tlen > 19 ? 0 : 19 - tlen),
07be1b83
YO
2966 "");
2967 }
2968}
3df15adc 2969
07be1b83
YO
2970#endif
2971
0a4db386
YO
2972/* reg_check_named_buff_matched()
2973 * Checks to see if a named buffer has matched. The data array of
2974 * buffer numbers corresponding to the buffer is expected to reside
2975 * in the regexp->data->data array in the slot stored in the ARG() of
2976 * node involved. Note that this routine doesn't actually care about the
2977 * name, that information is not preserved from compilation to execution.
2978 * Returns the index of the leftmost defined buffer with the given name
2979 * or 0 if non of the buffers matched.
2980 */
2981STATIC I32
7918f24d
NC
2982S_reg_check_named_buff_matched(pTHX_ const regexp *rex, const regnode *scan)
2983{
0a4db386 2984 I32 n;
f8fc2ecf 2985 RXi_GET_DECL(rex,rexi);
ad64d0ec 2986 SV *sv_dat= MUTABLE_SV(rexi->data->data[ ARG( scan ) ]);
0a4db386 2987 I32 *nums=(I32*)SvPVX(sv_dat);
7918f24d
NC
2988
2989 PERL_ARGS_ASSERT_REG_CHECK_NAMED_BUFF_MATCHED;
2990
0a4db386
YO
2991 for ( n=0; n<SvIVX(sv_dat); n++ ) {
2992 if ((I32)*PL_reglastparen >= nums[n] &&
f0ab9afb 2993 PL_regoffs[nums[n]].end != -1)
0a4db386
YO
2994 {
2995 return nums[n];
2996 }
2997 }
2998 return 0;
2999}
3000
2f554ef7
DM
3001
3002/* free all slabs above current one - called during LEAVE_SCOPE */
3003
3004STATIC void
3005S_clear_backtrack_stack(pTHX_ void *p)
3006{
3007 regmatch_slab *s = PL_regmatch_slab->next;
3008 PERL_UNUSED_ARG(p);
3009
3010 if (!s)
3011 return;
3012 PL_regmatch_slab->next = NULL;
3013 while (s) {
3014 regmatch_slab * const osl = s;
3015 s = s->next;
3016 Safefree(osl);
3017 }
3018}
3019
3020
28d8d7f4
YO
3021#define SETREX(Re1,Re2) \
3022 if (PL_reg_eval_set) PM_SETRE((PL_reg_curpm), (Re2)); \
3023 Re1 = (Re2)
3024
d6a28714 3025STATIC I32 /* 0 failure, 1 success */
24b23f37 3026S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
d6a28714 3027{
a35a87e7 3028#if PERL_VERSION < 9 && !defined(PERL_CORE)
54df2634
NC
3029 dMY_CXT;
3030#endif
27da23d5 3031 dVAR;
f2ed9b32 3032 register const bool utf8_target = PL_reg_match_utf8;
4ad0818d 3033 const U32 uniflags = UTF8_ALLOW_DEFAULT;
288b8c02
NC
3034 REGEXP *rex_sv = reginfo->prog;
3035 regexp *rex = (struct regexp *)SvANY(rex_sv);
f8fc2ecf 3036 RXi_GET_DECL(rex,rexi);
2f554ef7 3037 I32 oldsave;
5d9a96ca
DM
3038 /* the current state. This is a cached copy of PL_regmatch_state */
3039 register regmatch_state *st;
5d9a96ca
DM
3040 /* cache heavy used fields of st in registers */
3041 register regnode *scan;
3042 register regnode *next;
438e9bae 3043 register U32 n = 0; /* general value; init to avoid compiler warning */
24d3c4a9 3044 register I32 ln = 0; /* len or last; init to avoid compiler warning */
5d9a96ca 3045 register char *locinput = PL_reginput;
5d9a96ca 3046 register I32 nextchr; /* is always set to UCHARAT(locinput) */
24d3c4a9 3047
b69b0499 3048 bool result = 0; /* return value of S_regmatch */
24d3c4a9 3049 int depth = 0; /* depth of backtrack stack */
4b196cd4
YO
3050 U32 nochange_depth = 0; /* depth of GOSUB recursion with nochange */
3051 const U32 max_nochange_depth =
3052 (3 * rex->nparens > MAX_RECURSE_EVAL_NOCHANGE_DEPTH) ?
3053 3 * rex->nparens : MAX_RECURSE_EVAL_NOCHANGE_DEPTH;
77cb431f
DM
3054 regmatch_state *yes_state = NULL; /* state to pop to on success of
3055 subpattern */
e2e6a0f1
YO
3056 /* mark_state piggy backs on the yes_state logic so that when we unwind
3057 the stack on success we can update the mark_state as we go */
3058 regmatch_state *mark_state = NULL; /* last mark state we have seen */
faec1544 3059 regmatch_state *cur_eval = NULL; /* most recent EVAL_AB state */
b8591aee 3060 struct regmatch_state *cur_curlyx = NULL; /* most recent curlyx */
40a82448 3061 U32 state_num;
5d458dd8
YO
3062 bool no_final = 0; /* prevent failure from backtracking? */
3063 bool do_cutgroup = 0; /* no_final only until next branch/trie entry */
e2e6a0f1 3064 char *startpoint = PL_reginput;
5d458dd8
YO
3065 SV *popmark = NULL; /* are we looking for a mark? */
3066 SV *sv_commit = NULL; /* last mark name seen in failure */
3067 SV *sv_yes_mark = NULL; /* last mark name we have seen
486ec47a 3068 during a successful match */
5d458dd8
YO
3069 U32 lastopen = 0; /* last open we saw */
3070 bool has_cutgroup = RX_HAS_CUTGROUP(rex) ? 1 : 0;
19b95bf0 3071 SV* const oreplsv = GvSV(PL_replgv);
24d3c4a9
DM
3072 /* these three flags are set by various ops to signal information to
3073 * the very next op. They have a useful lifetime of exactly one loop
3074 * iteration, and are not preserved or restored by state pushes/pops
3075 */
3076 bool sw = 0; /* the condition value in (?(cond)a|b) */
3077 bool minmod = 0; /* the next "{n,m}" is a "{n,m}?" */
3078 int logical = 0; /* the following EVAL is:
3079 0: (?{...})
3080 1: (?(?{...})X|Y)
3081 2: (??{...})
3082 or the following IFMATCH/UNLESSM is:
3083 false: plain (?=foo)
3084 true: used as a condition: (?(?=foo))
3085 */
95b24440 3086#ifdef DEBUGGING
e68ec53f 3087 GET_RE_DEBUG_FLAGS_DECL;
d6a28714
JH
3088#endif
3089
7918f24d
NC
3090 PERL_ARGS_ASSERT_REGMATCH;
3091
3b57cd43 3092 DEBUG_OPTIMISE_r( DEBUG_EXECUTE_r({
24b23f37 3093 PerlIO_printf(Perl_debug_log,"regmatch start\n");
3b57cd43 3094 }));
5d9a96ca
DM
3095 /* on first ever call to regmatch, allocate first slab */
3096 if (!PL_regmatch_slab) {
3097 Newx(PL_regmatch_slab, 1, regmatch_slab);
3098 PL_regmatch_slab->prev = NULL;
3099 PL_regmatch_slab->next = NULL;
86545054 3100 PL_regmatch_state = SLAB_FIRST(PL_regmatch_slab);
5d9a96ca
DM
3101 }
3102
2f554ef7
DM
3103 oldsave = PL_savestack_ix;
3104 SAVEDESTRUCTOR_X(S_clear_backtrack_stack, NULL);
3105 SAVEVPTR(PL_regmatch_slab);
3106 SAVEVPTR(PL_regmatch_state);
5d9a96ca
DM
3107
3108 /* grab next free state slot */
3109 st = ++PL_regmatch_state;
86545054 3110 if (st > SLAB_LAST(PL_regmatch_slab))
5d9a96ca
DM
3111 st = PL_regmatch_state = S_push_slab(aTHX);
3112
d6a28714
JH
3113 /* Note that nextchr is a byte even in UTF */
3114 nextchr = UCHARAT(locinput);
3115 scan = prog;
3116 while (scan != NULL) {
8ba1375e 3117
a3621e74 3118 DEBUG_EXECUTE_r( {
6136c704 3119 SV * const prop = sv_newmortal();
1de06328 3120 regnode *rnext=regnext(scan);
f2ed9b32 3121 DUMP_EXEC_POS( locinput, scan, utf8_target );
32fc9b6a 3122 regprop(rex, prop, scan);
07be1b83
YO
3123
3124 PerlIO_printf(Perl_debug_log,
3125 "%3"IVdf":%*s%s(%"IVdf")\n",
f8fc2ecf 3126 (IV)(scan - rexi->program), depth*2, "",
07be1b83 3127 SvPVX_const(prop),
1de06328 3128 (PL_regkind[OP(scan)] == END || !rnext) ?
f8fc2ecf 3129 0 : (IV)(rnext - rexi->program));
2a782b5b 3130 });
d6a28714
JH
3131
3132 next = scan + NEXT_OFF(scan);
3133 if (next == scan)
3134 next = NULL;
40a82448 3135 state_num = OP(scan);
d6a28714 3136
40a82448 3137 reenter_switch:
34a81e2b
B
3138
3139 assert(PL_reglastparen == &rex->lastparen);
3140 assert(PL_reglastcloseparen == &rex->lastcloseparen);
3141 assert(PL_regoffs == rex->offs);
3142
40a82448 3143 switch (state_num) {
d6a28714 3144 case BOL:
7fba1cd6 3145 if (locinput == PL_bostr)
d6a28714 3146 {
3b0527fe 3147 /* reginfo->till = reginfo->bol; */
b8c5462f
JH
3148 break;
3149 }
d6a28714
JH
3150 sayNO;
3151 case MBOL:
12d33761
HS
3152 if (locinput == PL_bostr ||
3153 ((nextchr || locinput < PL_regeol) && locinput[-1] == '\n'))
d6a28714 3154 {
b8c5462f
JH
3155 break;
3156 }
d6a28714
JH
3157 sayNO;
3158 case SBOL:
c2a73568 3159 if (locinput == PL_bostr)
b8c5462f 3160 break;
d6a28714
JH
3161 sayNO;
3162 case GPOS:
3b0527fe 3163 if (locinput == reginfo->ganch)
d6a28714
JH
3164 break;
3165 sayNO;
ee9b8eae
YO
3166
3167 case KEEPS:
3168 /* update the startpoint */
f0ab9afb 3169 st->u.keeper.val = PL_regoffs[0].start;
ee9b8eae 3170 PL_reginput = locinput;
f0ab9afb 3171 PL_regoffs[0].start = locinput - PL_bostr;
ee9b8eae
YO
3172 PUSH_STATE_GOTO(KEEPS_next, next);
3173 /*NOT-REACHED*/
3174 case KEEPS_next_fail:
3175 /* rollback the start point change */
f0ab9afb 3176 PL_regoffs[0].start = st->u.keeper.val;
ee9b8eae
YO
3177 sayNO_SILENT;
3178 /*NOT-REACHED*/
d6a28714 3179 case EOL:
d6a28714
JH
3180 goto seol;
3181 case MEOL:
d6a28714 3182 if ((nextchr || locinput < PL_regeol) && nextchr != '\n')
b8c5462f 3183 sayNO;
b8c5462f 3184 break;
d6a28714
JH
3185 case SEOL:
3186 seol:
3187 if ((nextchr || locinput < PL_regeol) && nextchr != '\n')
b8c5462f 3188 sayNO;
d6a28714 3189 if (PL_regeol - locinput > 1)
b8c5462f 3190 sayNO;
b8c5462f 3191 break;
d6a28714
JH
3192 case EOS:
3193 if (PL_regeol != locinput)
b8c5462f 3194 sayNO;
d6a28714 3195 break;
ffc61ed2 3196 case SANY:
d6a28714 3197 if (!nextchr && locinput >= PL_regeol)
4633a7c4 3198 sayNO;
f2ed9b32 3199 if (utf8_target) {
f33976b4
DB
3200 locinput += PL_utf8skip[nextchr];
3201 if (locinput > PL_regeol)
3202 sayNO;
3203 nextchr = UCHARAT(locinput);
3204 }
3205 else
3206 nextchr = UCHARAT(++locinput);
3207 break;
3208 case CANY:
3209 if (!nextchr && locinput >= PL_regeol)
3210 sayNO;
b8c5462f 3211 nextchr = UCHARAT(++locinput);
a0d0e21e 3212 break;
ffc61ed2 3213 case REG_ANY:
1aa99e6b
IH
3214 if ((!nextchr && locinput >= PL_regeol) || nextchr == '\n')
3215 sayNO;
f2ed9b32 3216 if (utf8_target) {
b8c5462f 3217 locinput += PL_utf8skip[nextchr];
d6a28714
JH
3218 if (locinput > PL_regeol)
3219 sayNO;
a0ed51b3 3220 nextchr = UCHARAT(locinput);
a0ed51b3 3221 }
1aa99e6b
IH
3222 else
3223 nextchr = UCHARAT(++locinput);
a0ed51b3 3224 break;
166ba7cd
DM
3225
3226#undef ST
3227#define ST st->u.trie
786e8c11
YO
3228 case TRIEC:
3229 /* In this case the charclass data is available inline so
3230 we can fail fast without a lot of extra overhead.
3231 */
f2ed9b32 3232 if (scan->flags == EXACT || !utf8_target) {
786e8c11
YO
3233 if(!ANYOF_BITMAP_TEST(scan, *locinput)) {
3234 DEBUG_EXECUTE_r(
3235 PerlIO_printf(Perl_debug_log,
3236 "%*s %sfailed to match trie start class...%s\n",
5bc10b2c 3237 REPORT_CODE_OFF+depth*2, "", PL_colors[4], PL_colors[5])
786e8c11
YO
3238 );
3239 sayNO_SILENT;
3240 /* NOTREACHED */
3241 }
3242 }
3243 /* FALL THROUGH */
5b47454d 3244 case TRIE:
2e64971a
DM
3245 /* the basic plan of execution of the trie is:
3246 * At the beginning, run though all the states, and
3247 * find the longest-matching word. Also remember the position
3248 * of the shortest matching word. For example, this pattern:
3249 * 1 2 3 4 5
3250 * ab|a|x|abcd|abc
3251 * when matched against the string "abcde", will generate
3252 * accept states for all words except 3, with the longest
3253 * matching word being 4, and the shortest being 1 (with
3254 * the position being after char 1 of the string).
3255 *
3256 * Then for each matching word, in word order (i.e. 1,2,4,5),
3257 * we run the remainder of the pattern; on each try setting
3258 * the current position to the character following the word,
3259 * returning to try the next word on failure.
3260 *
3261 * We avoid having to build a list of words at runtime by
3262 * using a compile-time structure, wordinfo[].prev, which
3263 * gives, for each word, the previous accepting word (if any).
3264 * In the case above it would contain the mappings 1->2, 2->0,
3265 * 3->0, 4->5, 5->1. We can use this table to generate, from
3266 * the longest word (4 above), a list of all words, by
3267 * following the list of prev pointers; this gives us the
3268 * unordered list 4,5,1,2. Then given the current word we have
3269 * just tried, we can go through the list and find the
3270 * next-biggest word to try (so if we just failed on word 2,
3271 * the next in the list is 4).
3272 *
3273 * Since at runtime we don't record the matching position in
3274 * the string for each word, we have to work that out for
3275 * each word we're about to process. The wordinfo table holds
3276 * the character length of each word; given that we recorded
3277 * at the start: the position of the shortest word and its
3278 * length in chars, we just need to move the pointer the
3279 * difference between the two char lengths. Depending on
3280 * Unicode status and folding, that's cheap or expensive.
3281 *
3282 * This algorithm is optimised for the case where are only a
3283 * small number of accept states, i.e. 0,1, or maybe 2.
3284 * With lots of accepts states, and having to try all of them,
3285 * it becomes quadratic on number of accept states to find all
3286 * the next words.
3287 */
3288
3dab1dad 3289 {
07be1b83 3290 /* what type of TRIE am I? (utf8 makes this contextual) */
a0a388a1 3291 DECL_TRIE_TYPE(scan);
3dab1dad
YO
3292
3293 /* what trie are we using right now */
be8e71aa 3294 reg_trie_data * const trie
f8fc2ecf 3295 = (reg_trie_data*)rexi->data->data[ ARG( scan ) ];
85fbaab2 3296 HV * widecharmap = MUTABLE_HV(rexi->data->data[ ARG( scan ) + 1 ]);
3dab1dad 3297 U32 state = trie->startstate;
166ba7cd 3298
3dab1dad
YO
3299 if (trie->bitmap && trie_type != trie_utf8_fold &&
3300 !TRIE_BITMAP_TEST(trie,*locinput)
3301 ) {
3302 if (trie->states[ state ].wordnum) {
3303 DEBUG_EXECUTE_r(
3304 PerlIO_printf(Perl_debug_log,
3305 "%*s %smatched empty string...%s\n",
5bc10b2c 3306 REPORT_CODE_OFF+depth*2, "", PL_colors[4], PL_colors[5])
3dab1dad 3307 );
20dbff7c
YO
3308 if (!trie->jump)
3309 break;
3dab1dad
YO
3310 } else {
3311 DEBUG_EXECUTE_r(
3312 PerlIO_printf(Perl_debug_log,
786e8c11 3313 "%*s %sfailed to match trie start class...%s\n",
5bc10b2c 3314 REPORT_CODE_OFF+depth*2, "", PL_colors[4], PL_colors[5])
3dab1dad
YO
3315 );
3316 sayNO_SILENT;
3317 }
3318 }
166ba7cd 3319
786e8c11
YO
3320 {
3321 U8 *uc = ( U8* )locinput;
3322
3323 STRLEN len = 0;
3324 STRLEN foldlen = 0;
3325 U8 *uscan = (U8*)NULL;
786e8c11 3326 U8 foldbuf[ UTF8_MAXBYTES_CASE + 1 ];
2e64971a
DM
3327 U32 charcount = 0; /* how many input chars we have matched */
3328 U32 accepted = 0; /* have we seen any accepting states? */
786e8c11 3329
786e8c11
YO
3330 ST.B = next;
3331 ST.jump = trie->jump;
786e8c11 3332 ST.me = scan;
2e64971a
DM
3333 ST.firstpos = NULL;
3334 ST.longfold = FALSE; /* char longer if folded => it's harder */
3335 ST.nextword = 0;
3336
3337 /* fully traverse the TRIE; note the position of the
3338 shortest accept state and the wordnum of the longest
3339 accept state */
07be1b83 3340
a3621e74 3341 while ( state && uc <= (U8*)PL_regeol ) {
786e8c11 3342 U32 base = trie->states[ state ].trans.base;
f9f4320a 3343 UV uvc = 0;
acb909b4 3344 U16 charid = 0;
2e64971a
DM
3345 U16 wordnum;
3346 wordnum = trie->states[ state ].wordnum;
3347
3348 if (wordnum) { /* it's an accept state */
3349 if (!accepted) {
3350 accepted = 1;
3351 /* record first match position */
3352 if (ST.longfold) {
3353 ST.firstpos = (U8*)locinput;
3354 ST.firstchars = 0;
5b47454d 3355 }
2e64971a
DM
3356 else {
3357 ST.firstpos = uc;
3358 ST.firstchars = charcount;
3359 }
3360 }
3361 if (!ST.nextword || wordnum < ST.nextword)
3362 ST.nextword = wordnum;
3363 ST.topword = wordnum;
786e8c11 3364 }
a3621e74 3365
07be1b83 3366 DEBUG_TRIE_EXECUTE_r({
f2ed9b32 3367 DUMP_EXEC_POS( (char *)uc, scan, utf8_target );
a3621e74 3368 PerlIO_printf( Perl_debug_log,
2e64971a 3369 "%*s %sState: %4"UVxf" Accepted: %c ",
5bc10b2c 3370 2+depth * 2, "", PL_colors[4],
2e64971a 3371 (UV)state, (accepted ? 'Y' : 'N'));
07be1b83 3372 });
a3621e74 3373
2e64971a 3374 /* read a char and goto next state */
a3621e74 3375 if ( base ) {
6dd2be57 3376 I32 offset;
55eed653
NC
3377 REXEC_TRIE_READ_CHAR(trie_type, trie, widecharmap, uc,
3378 uscan, len, uvc, charid, foldlen,
3379 foldbuf, uniflags);
2e64971a
DM
3380 charcount++;
3381 if (foldlen>0)
3382 ST.longfold = TRUE;
5b47454d 3383 if (charid &&
6dd2be57
DM
3384 ( ((offset =
3385 base + charid - 1 - trie->uniquecharcount)) >= 0)
3386
3387 && ((U32)offset < trie->lasttrans)
3388 && trie->trans[offset].check == state)
5b47454d 3389 {
6dd2be57 3390 state = trie->trans[offset].next;
5b47454d
DM
3391 }
3392 else {
3393 state = 0;
3394<