xref: /openbsd/gnu/usr.bin/perl/regexp.h (revision 274d7c50)
1 /*    regexp.h
2  *
3  *    Copyright (C) 1993, 1994, 1996, 1997, 1999, 2000, 2001, 2003,
4  *    2005, 2006, 2007, 2008 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  */
10 
11 /*
12  * Definitions etc. for regexp(3) routines.
13  *
14  * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
15  * not the System V one.
16  */
17 #ifndef PLUGGABLE_RE_EXTENSION
18 /* we don't want to include this stuff if we are inside of
19    an external regex engine based on the core one - like re 'debug'*/
20 
21 #include "utf8.h"
22 
23 struct regnode {
24     U8	flags;
25     U8  type;
26     U16 next_off;
27 };
28 
29 typedef struct regnode regnode;
30 
31 struct reg_substr_data;
32 
33 struct reg_data;
34 
35 struct regexp_engine;
36 struct regexp;
37 
38 struct reg_substr_datum {
39     SSize_t min_offset; /* min pos (in chars) that substr must appear */
40     SSize_t max_offset  /* max pos (in chars) that substr must appear */;
41     SV *substr;		/* non-utf8 variant */
42     SV *utf8_substr;	/* utf8 variant */
43     SSize_t end_shift;  /* how many fixed chars must end the string */
44 };
45 struct reg_substr_data {
46     U8      check_ix;   /* index into data[] of check substr */
47     struct reg_substr_datum data[3];	/* Actual array */
48 };
49 
50 #ifdef PERL_ANY_COW
51 #define SV_SAVED_COPY   SV *saved_copy; /* If non-NULL, SV which is COW from original */
52 #else
53 #define SV_SAVED_COPY
54 #endif
55 
56 /* offsets within a string of a particular /(.)/ capture */
57 
58 typedef struct regexp_paren_pair {
59     SSize_t start;
60     SSize_t end;
61     /* 'start_tmp' records a new opening position before the matching end
62      * has been found, so that the old start and end values are still
63      * valid, e.g.
64      *	  "abc" =~ /(.(?{print "[$1]"}))+/
65      *outputs [][a][b]
66      * This field is not part of the API.  */
67     SSize_t start_tmp;
68 } regexp_paren_pair;
69 
70 #if defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_UTF8_C)
71 #define _invlist_union(a, b, output) _invlist_union_maybe_complement_2nd(a, b, FALSE, output)
72 #define _invlist_intersection(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, FALSE, output)
73 
74 /* Subtracting b from a leaves in a everything that was there that isn't in b,
75  * that is the intersection of a with b's complement */
76 #define _invlist_subtract(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, TRUE, output)
77 #endif
78 
79 /* record the position of a (?{...}) within a pattern */
80 
81 struct reg_code_block {
82     STRLEN start;
83     STRLEN end;
84     OP     *block;
85     REGEXP *src_regex;
86 };
87 
88 /* array of reg_code_block's plus header info */
89 
90 struct reg_code_blocks {
91     int refcnt; /* we may be pointed to from a regex and from the savestack */
92     int  count;    /* how many code blocks */
93     struct reg_code_block *cb; /* array of reg_code_block's */
94 };
95 
96 
97 /*
98   The regexp/REGEXP struct, see L<perlreapi> for further documentation
99   on the individual fields. The struct is ordered so that the most
100   commonly used fields are placed at the start.
101 
102   Any patch that adds items to this struct will need to include
103   changes to F<sv.c> (C<Perl_re_dup()>) and F<regcomp.c>
104   (C<pregfree()>). This involves freeing or cloning items in the
105   regexp's data array based on the data item's type.
106 */
107 
108 typedef struct regexp {
109     _XPV_HEAD;
110     const struct regexp_engine* engine; /* what engine created this regexp? */
111     REGEXP *mother_re; /* what re is this a lightweight copy of? */
112     HV *paren_names;   /* Optional hash of paren names */
113 
114     /*----------------------------------------------------------------------
115      * Information about the match that the perl core uses to manage things
116      */
117 
118     U32 extflags;      /* Flags used both externally and internally */
119     SSize_t minlen;    /* minimum possible number of chars in string to match */
120     SSize_t minlenret; /* mininum possible number of chars in $& */
121     STRLEN gofs;       /* chars left of pos that we search from */
122                        /* substring data about strings that must appear in
123                         * the final match, used for optimisations */
124     struct reg_substr_data *substrs;
125     U32 nparens;       /* number of capture buffers */
126 
127     /* private engine specific data */
128 
129     U32 intflags;      /* Engine Specific Internal flags */
130     void *pprivate;    /* Data private to the regex engine which
131                         * created this object. */
132 
133     /*----------------------------------------------------------------------
134      * Data about the last/current match. These are modified during matching
135      */
136 
137     U32 lastparen;           /* last open paren matched */
138     U32 lastcloseparen;      /* last close paren matched */
139     regexp_paren_pair *offs; /* Array of offsets for (@-) and (@+) */
140     char **recurse_locinput; /* used to detect infinite recursion, XXX: move to internal */
141 
142     /*---------------------------------------------------------------------- */
143 
144     char *subbeg;       /* saved or original string so \digit works forever. */
145     SV_SAVED_COPY       /* If non-NULL, SV which is COW from original */
146     SSize_t sublen;     /* Length of string pointed by subbeg */
147     SSize_t suboffset;  /* byte offset of subbeg from logical start of str */
148     SSize_t subcoffset; /* suboffset equiv, but in chars (for @-/@+) */
149 
150     /* Information about the match that isn't often used */
151 
152     SSize_t maxlen;  /* minimum possible number of chars in string to match */
153 
154     /*---------------------------------------------------------------------- */
155 
156     /* offset from wrapped to the start of precomp */
157     PERL_BITFIELD32 pre_prefix:4;
158 
159     /* original flags used to compile the pattern, may differ from
160      * extflags in various ways */
161     PERL_BITFIELD32 compflags:9;
162 
163     /*---------------------------------------------------------------------- */
164 
165     CV *qr_anoncv;      /* the anon sub wrapped round qr/(?{..})/ */
166 } regexp;
167 
168 
169 #define RXp_PAREN_NAMES(rx)	((rx)->paren_names)
170 
171 /* used for high speed searches */
172 typedef struct re_scream_pos_data_s
173 {
174     char **scream_olds;		/* match pos */
175     SSize_t *scream_pos;	/* Internal iterator of scream. */
176 } re_scream_pos_data;
177 
178 /* regexp_engine structure. This is the dispatch table for regexes.
179  * Any regex engine implementation must be able to build one of these.
180  */
181 typedef struct regexp_engine {
182     REGEXP* (*comp) (pTHX_ SV * const pattern, U32 flags);
183     I32     (*exec) (pTHX_ REGEXP * const rx, char* stringarg, char* strend,
184                      char* strbeg, SSize_t minend, SV* sv,
185                      void* data, U32 flags);
186     char*   (*intuit) (pTHX_
187                         REGEXP * const rx,
188                         SV *sv,
189                         const char * const strbeg,
190                         char *strpos,
191                         char *strend,
192                         const U32 flags,
193                        re_scream_pos_data *data);
194     SV*     (*checkstr) (pTHX_ REGEXP * const rx);
195     void    (*rxfree) (pTHX_ REGEXP * const rx);
196     void    (*numbered_buff_FETCH) (pTHX_ REGEXP * const rx, const I32 paren,
197                                     SV * const sv);
198     void    (*numbered_buff_STORE) (pTHX_ REGEXP * const rx, const I32 paren,
199                                    SV const * const value);
200     I32     (*numbered_buff_LENGTH) (pTHX_ REGEXP * const rx, const SV * const sv,
201                                     const I32 paren);
202     SV*     (*named_buff) (pTHX_ REGEXP * const rx, SV * const key,
203                            SV * const value, const U32 flags);
204     SV*     (*named_buff_iter) (pTHX_ REGEXP * const rx, const SV * const lastkey,
205                                 const U32 flags);
206     SV*     (*qr_package)(pTHX_ REGEXP * const rx);
207 #ifdef USE_ITHREADS
208     void*   (*dupe) (pTHX_ REGEXP * const rx, CLONE_PARAMS *param);
209 #endif
210     REGEXP* (*op_comp) (pTHX_ SV ** const patternp, int pat_count,
211 		    OP *expr, const struct regexp_engine* eng,
212 		    REGEXP *old_re,
213 		    bool *is_bare_re, U32 orig_rx_flags, U32 pm_flags);
214 } regexp_engine;
215 
216 /*
217   These are passed to the numbered capture variable callbacks as the
218   paren name. >= 1 is reserved for actual numbered captures, i.e. $1,
219   $2 etc.
220 */
221 #define RX_BUFF_IDX_CARET_PREMATCH  -5 /* ${^PREMATCH}  */
222 #define RX_BUFF_IDX_CARET_POSTMATCH -4 /* ${^POSTMATCH} */
223 #define RX_BUFF_IDX_CARET_FULLMATCH -3 /* ${^MATCH}     */
224 #define RX_BUFF_IDX_PREMATCH        -2 /* $` */
225 #define RX_BUFF_IDX_POSTMATCH       -1 /* $' */
226 #define RX_BUFF_IDX_FULLMATCH        0 /* $& */
227 
228 /*
229   Flags that are passed to the named_buff and named_buff_iter
230   callbacks above. Those routines are called from universal.c via the
231   Tie::Hash::NamedCapture interface for %+ and %- and the re::
232   functions in the same file.
233 */
234 
235 /* The Tie::Hash::NamedCapture operation this is part of, if any */
236 #define RXapif_FETCH     0x0001
237 #define RXapif_STORE     0x0002
238 #define RXapif_DELETE    0x0004
239 #define RXapif_CLEAR     0x0008
240 #define RXapif_EXISTS    0x0010
241 #define RXapif_SCALAR    0x0020
242 #define RXapif_FIRSTKEY  0x0040
243 #define RXapif_NEXTKEY   0x0080
244 
245 /* Whether %+ or %- is being operated on */
246 #define RXapif_ONE       0x0100 /* %+ */
247 #define RXapif_ALL       0x0200 /* %- */
248 
249 /* Whether this is being called from a re:: function */
250 #define RXapif_REGNAME         0x0400
251 #define RXapif_REGNAMES        0x0800
252 #define RXapif_REGNAMES_COUNT  0x1000
253 
254 /*
255 =head1 REGEXP Functions
256 
257 =for apidoc Am|REGEXP *|SvRX|SV *sv
258 
259 Convenience macro to get the REGEXP from a SV.  This is approximately
260 equivalent to the following snippet:
261 
262     if (SvMAGICAL(sv))
263         mg_get(sv);
264     if (SvROK(sv))
265         sv = MUTABLE_SV(SvRV(sv));
266     if (SvTYPE(sv) == SVt_REGEXP)
267         return (REGEXP*) sv;
268 
269 C<NULL> will be returned if a REGEXP* is not found.
270 
271 =for apidoc Am|bool|SvRXOK|SV* sv
272 
273 Returns a boolean indicating whether the SV (or the one it references)
274 is a REGEXP.
275 
276 If you want to do something with the REGEXP* later use SvRX instead
277 and check for NULL.
278 
279 =cut
280 */
281 
282 #define SvRX(sv)   (Perl_get_re_arg(aTHX_ sv))
283 #define SvRXOK(sv) cBOOL(Perl_get_re_arg(aTHX_ sv))
284 
285 
286 /* Flags stored in regexp->extflags
287  * These are used by code external to the regexp engine
288  *
289  * Note that the flags whose names start with RXf_PMf_ are defined in
290  * op_reg_common.h, being copied from the parallel flags of op_pmflags
291  *
292  * NOTE: if you modify any RXf flags you should run regen.pl or
293  * regen/regcomp.pl so that regnodes.h is updated with the changes.
294  *
295  */
296 
297 #include "op_reg_common.h"
298 
299 #define RXf_PMf_STD_PMMOD	(RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_FOLD|RXf_PMf_EXTENDED|RXf_PMf_EXTENDED_MORE|RXf_PMf_NOCAPTURE)
300 
301 #define CASE_STD_PMMOD_FLAGS_PARSE_SET(pmfl, x_count)                       \
302     case IGNORE_PAT_MOD:    *(pmfl) |= RXf_PMf_FOLD;       break;           \
303     case MULTILINE_PAT_MOD: *(pmfl) |= RXf_PMf_MULTILINE;  break;           \
304     case SINGLE_PAT_MOD:    *(pmfl) |= RXf_PMf_SINGLELINE; break;           \
305     case XTENDED_PAT_MOD:   if (x_count == 0) {                             \
306                                 *(pmfl) |= RXf_PMf_EXTENDED;                \
307                                 *(pmfl) &= ~RXf_PMf_EXTENDED_MORE;          \
308                             }                                               \
309                             else {                                          \
310                                 *(pmfl) |= RXf_PMf_EXTENDED                 \
311                                           |RXf_PMf_EXTENDED_MORE;           \
312                             }                                               \
313                             (x_count)++; break;                             \
314     case NOCAPTURE_PAT_MOD: *(pmfl) |= RXf_PMf_NOCAPTURE; break;
315 
316 /* Note, includes charset ones, assumes 0 is the default for them */
317 #define STD_PMMOD_FLAGS_CLEAR(pmfl)                        \
318     *(pmfl) &= ~(RXf_PMf_FOLD|RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_EXTENDED|RXf_PMf_EXTENDED_MORE|RXf_PMf_CHARSET|RXf_PMf_NOCAPTURE)
319 
320 /* chars and strings used as regex pattern modifiers
321  * Singular is a 'c'har, plural is a "string"
322  *
323  * NOTE, KEEPCOPY was originally 'k', but was changed to 'p' for preserve
324  * for compatibility reasons with Regexp::Common which highjacked (?k:...)
325  * for its own uses. So 'k' is out as well.
326  */
327 #define DEFAULT_PAT_MOD      '^'    /* Short for all the default modifiers */
328 #define EXEC_PAT_MOD         'e'
329 #define KEEPCOPY_PAT_MOD     'p'
330 #define NOCAPTURE_PAT_MOD    'n'
331 #define ONCE_PAT_MOD         'o'
332 #define GLOBAL_PAT_MOD       'g'
333 #define CONTINUE_PAT_MOD     'c'
334 #define MULTILINE_PAT_MOD    'm'
335 #define SINGLE_PAT_MOD       's'
336 #define IGNORE_PAT_MOD       'i'
337 #define XTENDED_PAT_MOD      'x'
338 #define NONDESTRUCT_PAT_MOD  'r'
339 #define LOCALE_PAT_MOD       'l'
340 #define UNICODE_PAT_MOD      'u'
341 #define DEPENDS_PAT_MOD      'd'
342 #define ASCII_RESTRICT_PAT_MOD 'a'
343 
344 #define ONCE_PAT_MODS        "o"
345 #define KEEPCOPY_PAT_MODS    "p"
346 #define NOCAPTURE_PAT_MODS   "n"
347 #define EXEC_PAT_MODS        "e"
348 #define LOOP_PAT_MODS        "gc"
349 #define NONDESTRUCT_PAT_MODS "r"
350 #define LOCALE_PAT_MODS      "l"
351 #define UNICODE_PAT_MODS     "u"
352 #define DEPENDS_PAT_MODS     "d"
353 #define ASCII_RESTRICT_PAT_MODS "a"
354 #define ASCII_MORE_RESTRICT_PAT_MODS "aa"
355 
356 /* This string is expected by regcomp.c to be ordered so that the first
357  * character is the flag in bit RXf_PMf_STD_PMMOD_SHIFT of extflags; the next
358  * character is bit +1, etc. */
359 #define STD_PAT_MODS        "msixxn"
360 
361 #define CHARSET_PAT_MODS    ASCII_RESTRICT_PAT_MODS DEPENDS_PAT_MODS LOCALE_PAT_MODS UNICODE_PAT_MODS
362 
363 /* This string is expected by XS_re_regexp_pattern() in universal.c to be ordered
364  * so that the first character is the flag in bit RXf_PMf_STD_PMMOD_SHIFT of
365  * extflags; the next character is in bit +1, etc. */
366 #define INT_PAT_MODS    STD_PAT_MODS    KEEPCOPY_PAT_MODS
367 
368 #define EXT_PAT_MODS    ONCE_PAT_MODS   KEEPCOPY_PAT_MODS  NOCAPTURE_PAT_MODS
369 #define QR_PAT_MODS     STD_PAT_MODS    EXT_PAT_MODS	   CHARSET_PAT_MODS
370 #define M_PAT_MODS      QR_PAT_MODS     LOOP_PAT_MODS
371 #define S_PAT_MODS      M_PAT_MODS      EXEC_PAT_MODS      NONDESTRUCT_PAT_MODS
372 
373 /*
374  * NOTE: if you modify any RXf flags you should run regen.pl or
375  * regen/regcomp.pl so that regnodes.h is updated with the changes.
376  *
377  */
378 
379 /*
380   Set in Perl_pmruntime for a split. Will be used by regex engines to
381   check whether they should set RXf_SKIPWHITE
382 */
383 #define RXf_SPLIT   RXf_PMf_SPLIT
384 
385 /* Currently the regex flags occupy a single 32-bit word.  Not all bits are
386  * currently used.  The lower bits are shared with their corresponding PMf flag
387  * bits, up to but not including _RXf_PMf_SHIFT_NEXT.  The unused bits
388  * immediately follow; finally the used RXf-only (unshared) bits, so that the
389  * highest bit in the word is used.  This gathers all the unused bits as a pool
390  * in the middle, like so: 11111111111111110000001111111111
391  * where the '1's represent used bits, and the '0's unused.  This design allows
392  * us to allocate off one end of the pool if we need to add a shared bit, and
393  * off the other end if we need a non-shared bit, without disturbing the other
394  * bits.  This maximizes the likelihood of being able to change things without
395  * breaking binary compatibility.
396  *
397  * To add shared bits, do so in op_reg_common.h.  This should change
398  * _RXf_PMf_SHIFT_NEXT so that things won't compile.  Then come to regexp.h and
399  * op.h and adjust the constant adders in the definitions of RXf_BASE_SHIFT and
400  * Pmf_BASE_SHIFT down by the number of shared bits you added.  That's it.
401  * Things should be binary compatible.  But if either of these gets to having
402  * to subtract rather than add, leave at 0 and instead adjust all the entries
403  * that are in terms of it.  But if the first one of those is already
404  * RXf_BASE_SHIFT+0, there are no bits left, and a redesign is in order.
405  *
406  * To remove unshared bits, just delete its entry.  If you're where breaking
407  * binary compatibility is ok to do, you might want to adjust things to move
408  * the newly opened space so that it gets absorbed into the common pool.
409  *
410  * To add unshared bits, first use up any gaps in the middle.  Otherwise,
411  * allocate off the low end until you get to RXf_BASE_SHIFT+0.  If that isn't
412  * enough, move RXf_BASE_SHIFT down (if possible) and add the new bit at the
413  * other end instead; this preserves binary compatibility.
414  *
415  * For the regexp bits, PL_reg_extflags_name[] in regnodes.h has a comment
416  * giving which bits are used/unused */
417 
418 #define RXf_BASE_SHIFT (_RXf_PMf_SHIFT_NEXT + 2)
419 
420 /* What we have seen */
421 #define RXf_NO_INPLACE_SUBST    (1U<<(RXf_BASE_SHIFT+2))
422 #define RXf_EVAL_SEEN   	(1U<<(RXf_BASE_SHIFT+3))
423 
424 /* Special */
425 #define RXf_UNBOUNDED_QUANTIFIER_SEEN   (1U<<(RXf_BASE_SHIFT+4))
426 #define RXf_CHECK_ALL   	(1U<<(RXf_BASE_SHIFT+5))
427 
428 /* UTF8 related */
429 #define RXf_MATCH_UTF8  	(1U<<(RXf_BASE_SHIFT+6)) /* $1 etc are utf8 */
430 
431 /* Intuit related */
432 #define RXf_USE_INTUIT_NOML	(1U<<(RXf_BASE_SHIFT+7))
433 #define RXf_USE_INTUIT_ML	(1U<<(RXf_BASE_SHIFT+8))
434 #define RXf_INTUIT_TAIL 	(1U<<(RXf_BASE_SHIFT+9))
435 #define RXf_USE_INTUIT		(RXf_USE_INTUIT_NOML|RXf_USE_INTUIT_ML)
436 
437 /* Do we have some sort of anchor? */
438 #define RXf_IS_ANCHORED         (1U<<(RXf_BASE_SHIFT+10))
439 
440 /* Copy and tainted info */
441 #define RXf_COPY_DONE   	(1U<<(RXf_BASE_SHIFT+11))
442 
443 /* post-execution: $1 et al are tainted */
444 #define RXf_TAINTED_SEEN	(1U<<(RXf_BASE_SHIFT+12))
445 /* this pattern was tainted during compilation */
446 #define RXf_TAINTED		(1U<<(RXf_BASE_SHIFT+13))
447 
448 /* Flags indicating special patterns */
449 #define RXf_START_ONLY		(1U<<(RXf_BASE_SHIFT+14)) /* Pattern is /^/ */
450 #define RXf_SKIPWHITE           (1U<<(RXf_BASE_SHIFT+15)) /* Pattern is for a */
451                                                           /* split " " */
452 #define RXf_WHITE		(1U<<(RXf_BASE_SHIFT+16)) /* Pattern is /\s+/ */
453 #define RXf_NULL		(1U<<(RXf_BASE_SHIFT+17)) /* Pattern is // */
454 
455 /* See comments at the beginning of these defines about adding bits.  The
456  * highest bit position should be used, so that if RXf_BASE_SHIFT gets
457  * increased, the #error below will be triggered so that you will be reminded
458  * to adjust things at the other end to keep the bit positions unchanged */
459 #if RXf_BASE_SHIFT+17 > 31
460 #   error Too many RXf_PMf bits used.  See comments at beginning of these for what to do
461 #endif
462 
463 /*
464  * NOTE: if you modify any RXf flags you should run regen.pl or
465  * regen/regcomp.pl so that regnodes.h is updated with the changes.
466  *
467  */
468 
469 #ifdef NO_TAINT_SUPPORT
470 #  define RX_ISTAINTED(rx_sv)           0
471 #  define RXp_ISTAINTED(prog)           0
472 #  define RX_TAINT_on(rx_sv)            NOOP
473 #  define RXp_MATCH_TAINTED(prog)       0
474 #  define RX_MATCH_TAINTED(rx_sv)       0
475 #  define RXp_MATCH_TAINTED_on(prog)    NOOP
476 #  define RX_MATCH_TAINTED_on(rx_sv)    NOOP
477 #  define RXp_MATCH_TAINTED_off(prog)   NOOP
478 #  define RX_MATCH_TAINTED_off(rx_sv)   NOOP
479 #else
480 #  define RX_ISTAINTED(rx_sv)           (RX_EXTFLAGS(rx_sv) & RXf_TAINTED)
481 #  define RXp_ISTAINTED(prog)           (RXp_EXTFLAGS(prog) & RXf_TAINTED)
482 #  define RX_TAINT_on(rx_sv)            (RX_EXTFLAGS(rx_sv) |= RXf_TAINTED)
483 #  define RXp_MATCH_TAINTED(prog)       (RXp_EXTFLAGS(prog) & RXf_TAINTED_SEEN)
484 #  define RX_MATCH_TAINTED(rx_sv)       (RX_EXTFLAGS(rx_sv) & RXf_TAINTED_SEEN)
485 #  define RXp_MATCH_TAINTED_on(prog)    (RXp_EXTFLAGS(prog) |= RXf_TAINTED_SEEN)
486 #  define RX_MATCH_TAINTED_on(rx_sv)    (RX_EXTFLAGS(rx_sv) |= RXf_TAINTED_SEEN)
487 #  define RXp_MATCH_TAINTED_off(prog)   (RXp_EXTFLAGS(prog) &= ~RXf_TAINTED_SEEN)
488 #  define RX_MATCH_TAINTED_off(rx_sv)   (RX_EXTFLAGS(rx_sv) &= ~RXf_TAINTED_SEEN)
489 #endif
490 
491 #define RXp_HAS_CUTGROUP(prog)          ((prog)->intflags & PREGf_CUTGROUP_SEEN)
492 
493 #define RX_MATCH_TAINTED_set(rx_sv, t)  ((t) \
494                                         ? RX_MATCH_TAINTED_on(rx_sv) \
495                                         : RX_MATCH_TAINTED_off(rx_sv))
496 
497 #define RXp_MATCH_COPIED(prog)          (RXp_EXTFLAGS(prog) & RXf_COPY_DONE)
498 #define RX_MATCH_COPIED(rx_sv)          (RX_EXTFLAGS(rx_sv) & RXf_COPY_DONE)
499 #define RXp_MATCH_COPIED_on(prog)       (RXp_EXTFLAGS(prog) |= RXf_COPY_DONE)
500 #define RX_MATCH_COPIED_on(rx_sv)       (RX_EXTFLAGS(rx_sv) |= RXf_COPY_DONE)
501 #define RXp_MATCH_COPIED_off(prog)      (RXp_EXTFLAGS(prog) &= ~RXf_COPY_DONE)
502 #define RX_MATCH_COPIED_off(rx_sv)      (RX_EXTFLAGS(rx_sv) &= ~RXf_COPY_DONE)
503 #define RX_MATCH_COPIED_set(rx_sv,t)    ((t) \
504                                          ? RX_MATCH_COPIED_on(rx_sv) \
505                                          : RX_MATCH_COPIED_off(rx_sv))
506 
507 #define RXp_EXTFLAGS(rx)                ((rx)->extflags)
508 #define RXp_COMPFLAGS(rx)               ((rx)->compflags)
509 
510 /* For source compatibility. We used to store these explicitly.  */
511 #define RX_PRECOMP(rx_sv)              (RX_WRAPPED(rx_sv) \
512                                             + ReANY(rx_sv)->pre_prefix)
513 #define RX_PRECOMP_const(rx_sv)        (RX_WRAPPED_const(rx_sv) \
514                                             + ReANY(rx_sv)->pre_prefix)
515 /* FIXME? Are we hardcoding too much here and constraining plugin extension
516    writers? Specifically, the value 1 assumes that the wrapped version always
517    has exactly one character at the end, a ')'. Will that always be true?  */
518 #define RX_PRELEN(rx_sv)                (RX_WRAPLEN(rx_sv) \
519                                             - ReANY(rx_sv)->pre_prefix - 1)
520 
521 #define RX_WRAPPED(rx_sv)               SvPVX(rx_sv)
522 #define RX_WRAPPED_const(rx_sv)         SvPVX_const(rx_sv)
523 #define RX_WRAPLEN(rx_sv)               SvCUR(rx_sv)
524 #define RX_CHECK_SUBSTR(rx_sv)          (ReANY(rx_sv)->check_substr)
525 #define RX_REFCNT(rx_sv)                SvREFCNT(rx_sv)
526 #define RX_EXTFLAGS(rx_sv)              RXp_EXTFLAGS(ReANY(rx_sv))
527 #define RX_COMPFLAGS(rx_sv)             RXp_COMPFLAGS(ReANY(rx_sv))
528 #define RXp_ENGINE(prog)                ((prog)->engine)
529 #define RX_ENGINE(rx_sv)                (RXp_ENGINE(ReANY(rx_sv)))
530 #define RXp_SUBBEG(prog)                (prog->subbeg)
531 #define RX_SUBBEG(rx_sv)                (RXp_SUBBEG(ReANY(rx_sv)))
532 #define RXp_SUBOFFSET(prog)             (prog->suboffset)
533 #define RX_SUBOFFSET(rx_sv)             (RXp_SUBOFFSET(ReANY(rx_sv)))
534 #define RX_SUBCOFFSET(rx_sv)            (ReANY(rx_sv)->subcoffset)
535 #define RXp_OFFS(prog)                  (prog->offs)
536 #define RX_OFFS(rx_sv)                  (RXp_OFFS(ReANY(rx_sv)))
537 #define RXp_NPARENS(prog)               (prog->nparens)
538 #define RX_NPARENS(rx_sv)               (RXp_NPARENS(ReANY(rx_sv)))
539 #define RX_SUBLEN(rx_sv)                (ReANY(rx_sv)->sublen)
540 #define RXp_MINLEN(prog)                (prog->minlen)
541 #define RX_MINLEN(rx_sv)                (RXp_MINLEN(ReANY(rx_sv)))
542 #define RXp_MINLENRET(prog)             (prog->minlenret)
543 #define RX_MINLENRET(rx_sv)             (RXp_MINLENRET(ReANY(rx_sv)))
544 #define RXp_GOFS(prog)                  (prog->gofs)
545 #define RX_GOFS(rx_sv)                  (RXp_GOFS(ReANY(rx_sv)))
546 #define RX_LASTPAREN(rx_sv)             (ReANY(rx_sv)->lastparen)
547 #define RX_LASTCLOSEPAREN(rx_sv)        (ReANY(rx_sv)->lastcloseparen)
548 #define RXp_SAVED_COPY(prog)            (prog->saved_copy)
549 #define RX_SAVED_COPY(rx_sv)            (RXp_SAVED_COPY(ReANY(rx_sv)))
550 /* last match was zero-length */
551 #define RXp_ZERO_LEN(prog) \
552         (RXp_OFFS(prog)[0].start + (SSize_t)RXp_GOFS(prog) \
553           == RXp_OFFS(prog)[0].end)
554 #define RX_ZERO_LEN(rx_sv)              (RXp_ZERO_LEN(ReANY(rx_sv)))
555 
556 #endif /* PLUGGABLE_RE_EXTENSION */
557 
558 /* Stuff that needs to be included in the pluggable extension goes below here */
559 
560 #ifdef PERL_ANY_COW
561 #define RXp_MATCH_COPY_FREE(prog) \
562 	STMT_START {if (RXp_SAVED_COPY(prog)) { \
563 	    SV_CHECK_THINKFIRST_COW_DROP(RXp_SAVED_COPY(prog)); \
564 	} \
565 	if (RXp_MATCH_COPIED(prog)) { \
566 	    Safefree(RXp_SUBBEG(prog)); \
567 	    RXp_MATCH_COPIED_off(prog); \
568 	}} STMT_END
569 #else
570 #define RXp_MATCH_COPY_FREE(prog) \
571 	STMT_START {if (RXp_MATCH_COPIED(prog)) { \
572 	    Safefree(RXp_SUBBEG(prog)); \
573 	    RXp_MATCH_COPIED_off(prog); \
574 	}} STMT_END
575 #endif
576 #define RX_MATCH_COPY_FREE(rx_sv)       RXp_MATCH_COPY_FREE(ReANY(rx_sv))
577 
578 #define RXp_MATCH_UTF8(prog)            (RXp_EXTFLAGS(prog) & RXf_MATCH_UTF8)
579 #define RX_MATCH_UTF8(rx_sv)            (RX_EXTFLAGS(rx_sv) & RXf_MATCH_UTF8)
580 #define RXp_MATCH_UTF8_on(prog)         (RXp_EXTFLAGS(prog) |= RXf_MATCH_UTF8)
581 #define RX_MATCH_UTF8_on(rx_sv)         (RXp_MATCH_UTF8_on(ReANY(rx_sv)))
582 #define RXp_MATCH_UTF8_off(prog)        (RXp_EXTFLAGS(prog) &= ~RXf_MATCH_UTF8)
583 #define RX_MATCH_UTF8_off(rx_sv)        (RXp_MATCH_UTF8_off(ReANY(rx_sv))
584 #define RXp_MATCH_UTF8_set(prog, t)     ((t) \
585                                         ? RXp_MATCH_UTF8_on(prog) \
586                                         : RXp_MATCH_UTF8_off(prog))
587 #define RX_MATCH_UTF8_set(rx_sv, t)     (RXp_MATCH_UTF8_set(ReANY(rx_sv), t))
588 
589 /* Whether the pattern stored at RX_WRAPPED is in UTF-8  */
590 #define RX_UTF8(rx_sv)                  SvUTF8(rx_sv)
591 
592 
593 /* bits in flags arg of Perl_regexec_flags() */
594 
595 #define REXEC_COPY_STR  0x01    /* Need to copy the string for captures. */
596 #define REXEC_CHECKED   0x02    /* re_intuit_start() already called. */
597 #define REXEC_SCREAM    0x04    /* currently unused. */
598 #define REXEC_IGNOREPOS 0x08    /* use stringarg, not pos(), for \G match */
599 #define REXEC_NOT_FIRST 0x10    /* This is another iteration of //g:
600                                    no need to copy string again */
601 
602                                      /* under REXEC_COPY_STR, it's ok for the
603                                         engine (modulo PL_sawamperand etc)
604                                         to skip copying: ... */
605 #define REXEC_COPY_SKIP_PRE  0x20    /* ...the $` part of the string, or */
606 #define REXEC_COPY_SKIP_POST 0x40    /* ...the $' part of the string */
607 #define REXEC_FAIL_ON_UNDERFLOW 0x80 /* fail the match if $& would start before
608                                         the start pos (so s/.\G// would fail
609                                         on second iteration */
610 
611 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
612 #  define ReREFCNT_inc(re)						\
613     ({									\
614 	/* This is here to generate a casting warning if incorrect.  */	\
615 	REGEXP *const _rerefcnt_inc = (re);				\
616 	assert(SvTYPE(_rerefcnt_inc) == SVt_REGEXP);			\
617 	SvREFCNT_inc(_rerefcnt_inc);					\
618 	_rerefcnt_inc;							\
619     })
620 #  define ReREFCNT_dec(re)						\
621     ({									\
622 	/* This is here to generate a casting warning if incorrect.  */	\
623 	REGEXP *const _rerefcnt_dec = (re);				\
624 	SvREFCNT_dec(_rerefcnt_dec);					\
625     })
626 #else
627 #  define ReREFCNT_dec(re)	SvREFCNT_dec(re)
628 #  define ReREFCNT_inc(re)	((REGEXP *) SvREFCNT_inc(re))
629 #endif
630 #define ReANY(re)		S_ReANY((const REGEXP *)(re))
631 
632 /* FIXME for plugins. */
633 
634 #define FBMcf_TAIL_DOLLAR	1
635 #define FBMcf_TAIL_DOLLARM	2
636 #define FBMcf_TAIL_Z		4
637 #define FBMcf_TAIL_z		8
638 #define FBMcf_TAIL		(FBMcf_TAIL_DOLLAR|FBMcf_TAIL_DOLLARM|FBMcf_TAIL_Z|FBMcf_TAIL_z)
639 
640 #define FBMrf_MULTILINE	1
641 
642 struct regmatch_state;
643 struct regmatch_slab;
644 
645 /* like regmatch_info_aux, but contains extra fields only needed if the
646  * pattern contains (?{}). If used, is snuck into the second slot in the
647  * regmatch_state stack at the start of execution */
648 
649 typedef struct {
650     regexp *rex;
651     PMOP    *curpm;     /* saved PL_curpm */
652 #ifdef PERL_ANY_COW
653     SV      *saved_copy; /* saved saved_copy field from rex */
654 #endif
655     char    *subbeg;    /* saved subbeg     field from rex */
656     STRLEN  sublen;     /* saved sublen     field from rex */
657     STRLEN  suboffset;  /* saved suboffset  field from rex */
658     STRLEN  subcoffset; /* saved subcoffset field from rex */
659     MAGIC   *pos_magic; /* pos() magic attached to $_ */
660     SSize_t pos;        /* the original value of pos() in pos_magic */
661     U8      pos_flags;  /* flags to be restored; currently only MGf_BYTES*/
662 } regmatch_info_aux_eval;
663 
664 
665 /* fields that logically  live in regmatch_info, but which need cleaning
666  * up on croak(), and so are instead are snuck into the first slot in
667  * the regmatch_state stack at the start of execution */
668 
669 typedef struct {
670     regmatch_info_aux_eval *info_aux_eval;
671     struct regmatch_state *old_regmatch_state; /* saved PL_regmatch_state */
672     struct regmatch_slab  *old_regmatch_slab;  /* saved PL_regmatch_slab */
673     char *poscache;	/* S-L cache of fail positions of WHILEMs */
674 } regmatch_info_aux;
675 
676 
677 /* some basic information about the current match that is created by
678  * Perl_regexec_flags and then passed to regtry(), regmatch() etc.
679  * It is allocated as a local var on the stack, so nothing should be
680  * stored in it that needs preserving or clearing up on croak().
681  * For that, see the aux_info and aux_info_eval members of the
682  * regmatch_state union. */
683 
684 typedef struct {
685     REGEXP *prog;        /* the regex being executed */
686     const char * strbeg; /* real start of string */
687     char *strend;        /* one byte beyond last char of match string */
688     char *till;          /* matches shorter than this fail (see minlen arg) */
689     SV *sv;              /* the SV string currently being matched */
690     char *ganch;         /* position of \G anchor */
691     char *cutpoint;      /* (*COMMIT) position (if any) */
692     regmatch_info_aux      *info_aux; /* extra fields that need cleanup */
693     regmatch_info_aux_eval *info_aux_eval; /* extra saved state for (?{}) */
694     I32  poscache_maxiter; /* how many whilems todo before S-L cache kicks in */
695     I32  poscache_iter;    /* current countdown from _maxiter to zero */
696     STRLEN poscache_size;  /* size of regmatch_info_aux.poscache */
697     bool intuit;    /* re_intuit_start() is the top-level caller */
698     bool is_utf8_pat;    /* regex is utf8 */
699     bool is_utf8_target; /* string being matched is utf8 */
700     bool warned; /* we have issued a recursion warning; no need for more */
701 } regmatch_info;
702 
703 
704 /* structures for holding and saving the state maintained by regmatch() */
705 
706 #ifndef MAX_RECURSE_EVAL_NOCHANGE_DEPTH
707 #define MAX_RECURSE_EVAL_NOCHANGE_DEPTH 10
708 #endif
709 
710 typedef I32 CHECKPOINT;
711 
712 typedef struct regmatch_state {
713     int resume_state;		/* where to jump to on return */
714     char *locinput;		/* where to backtrack in string on failure */
715 
716     union {
717 
718         /* the 'info_aux' and 'info_aux_eval' union members are cuckoos in
719          * the nest. They aren't saved backtrack state; rather they
720          * represent one or two extra chunks of data that need allocating
721          * at the start of a match. These fields would logically live in
722          * the regmatch_info struct, except that is allocated on the
723          * C stack, and these fields are all things that require cleanup
724          * after a croak(), when the stack is lost.
725          * As a convenience, we just use the first 1 or 2 regmatch_state
726          * slots to store this info, as we will be allocating a slab of
727          * these anyway. Otherwise we'd have to malloc and then free them,
728          * or allocate them on the save stack (where they will get
729          * realloced if the save stack grows).
730          * info_aux contains the extra fields that are always needed;
731          * info_aux_eval contains extra fields that only needed if
732          * the pattern contains code blocks
733          * We split them into two separate structs to avoid increasing
734          * the size of the union.
735          */
736 
737         regmatch_info_aux info_aux;
738 
739         regmatch_info_aux_eval info_aux_eval;
740 
741 	/* this is a fake union member that matches the first element
742 	 * of each member that needs to store positive backtrack
743 	 * information */
744 	struct {
745 	    struct regmatch_state *prev_yes_state;
746 	} yes;
747 
748         /* branchlike members */
749         /* this is a fake union member that matches the first elements
750          * of each member that needs to behave like a branch */
751         struct {
752 	    /* this first element must match u.yes */
753 	    struct regmatch_state *prev_yes_state;
754 	    U32 lastparen;
755 	    U32 lastcloseparen;
756 	    CHECKPOINT cp;
757 
758         } branchlike;
759 
760 	struct {
761 	    /* the first elements must match u.branchlike */
762 	    struct regmatch_state *prev_yes_state;
763 	    U32 lastparen;
764 	    U32 lastcloseparen;
765 	    CHECKPOINT cp;
766 
767 	    regnode *next_branch; /* next branch node */
768 	} branch;
769 
770 	struct {
771 	    /* the first elements must match u.branchlike */
772 	    struct regmatch_state *prev_yes_state;
773 	    U32 lastparen;
774 	    U32 lastcloseparen;
775 	    CHECKPOINT cp;
776 
777 	    U32		accepted; /* how many accepting states left */
778 	    bool	longfold;/* saw a fold with a 1->n char mapping */
779 	    U16         *jump;  /* positive offsets from me */
780 	    regnode	*me;	/* Which node am I - needed for jump tries*/
781 	    U8		*firstpos;/* pos in string of first trie match */
782 	    U32		firstchars;/* len in chars of firstpos from start */
783 	    U16		nextword;/* next word to try */
784 	    U16		topword; /* longest accepted word */
785 	} trie;
786 
787         /* special types - these members are used to store state for special
788            regops like eval, if/then, lookaround and the markpoint state */
789 	struct {
790 	    /* this first element must match u.yes */
791 	    struct regmatch_state *prev_yes_state;
792 	    struct regmatch_state *prev_curlyx;
793             struct regmatch_state *prev_eval;
794 	    REGEXP	*prev_rex;
795 	    CHECKPOINT	cp;	/* remember current savestack indexes */
796 	    CHECKPOINT	lastcp;
797             U32         close_paren; /* which close bracket is our end (+1) */
798 	    regnode	*B;	/* the node following us  */
799             char        *prev_recurse_locinput;
800 	} eval;
801 
802 	struct {
803 	    /* this first element must match u.yes */
804 	    struct regmatch_state *prev_yes_state;
805 	    I32 wanted;
806 	    I32 logical;	/* saved copy of 'logical' var */
807 	    regnode  *me; /* the IFMATCH/SUSPEND/UNLESSM node  */
808 	} ifmatch; /* and SUSPEND/UNLESSM */
809 
810 	struct {
811 	    /* this first element must match u.yes */
812 	    struct regmatch_state *prev_yes_state;
813 	    struct regmatch_state *prev_mark;
814 	    SV* mark_name;
815 	    char *mark_loc;
816 	} mark;
817 
818 	struct {
819 	    int val;
820 	} keeper;
821 
822         /* quantifiers - these members are used for storing state for
823            for the regops used to implement quantifiers */
824 	struct {
825 	    /* this first element must match u.yes */
826 	    struct regmatch_state *prev_yes_state;
827 	    struct regmatch_state *prev_curlyx; /* previous cur_curlyx */
828 	    regnode	*me;	/* the CURLYX node  */
829 	    regnode	*B;	/* the B node in /A*B/  */
830 	    CHECKPOINT	cp;	/* remember current savestack index */
831 	    bool	minmod;
832 	    int		parenfloor;/* how far back to strip paren data */
833 
834 	    /* these two are modified by WHILEM */
835 	    int		count;	/* how many instances of A we've matched */
836 	    char	*lastloc;/* where previous A matched (0-len detect) */
837 	} curlyx;
838 
839 	struct {
840 	    /* this first element must match u.yes */
841 	    struct regmatch_state *prev_yes_state;
842 	    struct regmatch_state *save_curlyx;
843 	    CHECKPOINT	cp;	/* remember current savestack indexes */
844 	    CHECKPOINT	lastcp;
845 	    char	*save_lastloc;	/* previous curlyx.lastloc */
846 	    I32		cache_offset;
847 	    I32		cache_mask;
848 	} whilem;
849 
850 	struct {
851 	    /* this first element must match u.yes */
852 	    struct regmatch_state *prev_yes_state;
853 	    int c1, c2;		/* case fold search */
854 	    CHECKPOINT cp;
855 	    U32 lastparen;
856 	    U32 lastcloseparen;
857 	    I32 alen;		/* length of first-matched A string */
858 	    I32 count;
859 	    bool minmod;
860 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
861 	    regnode *me;	/* the curlym node */
862             U8 c1_utf8[UTF8_MAXBYTES+1];  /* */
863             U8 c2_utf8[UTF8_MAXBYTES+1];
864 	} curlym;
865 
866 	struct {
867 	    U32 paren;
868 	    CHECKPOINT cp;
869 	    U32 lastparen;
870 	    U32 lastcloseparen;
871 	    int c1, c2;		/* case fold search */
872 	    char *maxpos;	/* highest possible point in string to match */
873 	    char *oldloc;	/* the previous locinput */
874 	    int count;
875 	    int min, max;	/* {m,n} */
876 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
877             U8 c1_utf8[UTF8_MAXBYTES+1];  /* */
878             U8 c2_utf8[UTF8_MAXBYTES+1];
879 	} curly; /* and CURLYN/PLUS/STAR */
880 
881     } u;
882 } regmatch_state;
883 
884 
885 
886 /* how many regmatch_state structs to allocate as a single slab.
887  * We do it in 4K blocks for efficiency. The "3" is 2 for the next/prev
888  * pointers, plus 1 for any mythical malloc overhead. */
889 
890 #define PERL_REGMATCH_SLAB_SLOTS \
891     ((4096 - 3 * sizeof (void*)) / sizeof(regmatch_state))
892 
893 typedef struct regmatch_slab {
894     regmatch_state states[PERL_REGMATCH_SLAB_SLOTS];
895     struct regmatch_slab *prev, *next;
896 } regmatch_slab;
897 
898 
899 
900 /*
901  * ex: set ts=8 sts=4 sw=4 et:
902  */
903