xref: /openbsd-src/gnu/usr.bin/perl/regexp.h (revision e9ce384231aabe5c5a622aa68cef46f2c5bfdb4a)
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     I32 min_offset;
40     I32 max_offset;
41     SV *substr;		/* non-utf8 variant */
42     SV *utf8_substr;	/* utf8 variant */
43     I32 end_shift;
44 };
45 struct reg_substr_data {
46     struct reg_substr_datum data[3];	/* Actual array */
47 };
48 
49 #ifdef PERL_ANY_COW
50 #define SV_SAVED_COPY   SV *saved_copy; /* If non-NULL, SV which is COW from original */
51 #else
52 #define SV_SAVED_COPY
53 #endif
54 
55 /* offsets within a string of a particular /(.)/ capture */
56 
57 typedef struct regexp_paren_pair {
58     I32 start;
59     I32 end;
60     /* 'start_tmp' records a new opening position before the matching end
61      * has been found, so that the old start and end values are still
62      * valid, e.g.
63      *	  "abc" =~ /(.(?{print "[$1]"}))+/
64      *outputs [][a][b]
65      * This field is not part of the API.  */
66     I32 start_tmp;
67 } regexp_paren_pair;
68 
69 #if defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_UTF8_C)
70 #define _invlist_union(a, b, output) _invlist_union_maybe_complement_2nd(a, b, FALSE, output)
71 #define _invlist_intersection(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, FALSE, output)
72 
73 /* Subtracting b from a leaves in a everything that was there that isn't in b,
74  * that is the intersection of a with b's complement */
75 #define _invlist_subtract(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, TRUE, output)
76 #endif
77 
78 /* record the position of a (?{...}) within a pattern */
79 
80 struct reg_code_block {
81     STRLEN start;
82     STRLEN end;
83     OP     *block;
84     REGEXP *src_regex;
85 };
86 
87 
88 /*
89   The regexp/REGEXP struct, see L<perlreapi> for further documentation
90   on the individual fields. The struct is ordered so that the most
91   commonly used fields are placed at the start.
92 
93   Any patch that adds items to this struct will need to include
94   changes to F<sv.c> (C<Perl_re_dup()>) and F<regcomp.c>
95   (C<pregfree()>). This involves freeing or cloning items in the
96   regexp's data array based on the data item's type.
97 */
98 
99 #define _REGEXP_COMMON							\
100         /* what engine created this regexp? */				\
101 	const struct regexp_engine* engine; 				\
102 	REGEXP *mother_re; /* what re is this a lightweight copy of? */	\
103 	HV *paren_names;   /* Optional hash of paren names */		\
104 	/* Information about the match that the perl core uses to */	\
105 	/* manage things */						\
106 	U32 extflags;	/* Flags used both externally and internally */	\
107 	I32 minlen;	/* mininum possible number of chars in string to match */\
108 	I32 minlenret;	/* mininum possible number of chars in $& */		\
109 	U32 gofs;	/* chars left of pos that we search from */	\
110 	/* substring data about strings that must appear in the */	\
111 	/* final match, used for optimisations */			\
112 	struct reg_substr_data *substrs;				\
113 	U32 nparens;	/* number of capture buffers */			\
114 	/* private engine specific data */				\
115 	U32 intflags;	/* Engine Specific Internal flags */		\
116 	void *pprivate;	/* Data private to the regex engine which */	\
117 			/* created this object. */			\
118 	/* Data about the last/current match. These are modified */	\
119 	/* during matching */						\
120 	U32 lastparen;			/* last open paren matched */	\
121 	U32 lastcloseparen;		/* last close paren matched */	\
122 	/* Array of offsets for (@-) and (@+) */			\
123 	regexp_paren_pair *offs;					\
124 	/* saved or original string so \digit works forever. */		\
125 	char *subbeg;							\
126 	SV_SAVED_COPY	/* If non-NULL, SV which is COW from original */\
127 	I32 sublen;	/* Length of string pointed by subbeg */	\
128 	I32 suboffset;	/* byte offset of subbeg from logical start of str */ \
129 	I32 subcoffset;	/* suboffset equiv, but in chars (for @-/@+) */ \
130 	/* Information about the match that isn't often used */		\
131 	/* offset from wrapped to the start of precomp */		\
132 	PERL_BITFIELD32 pre_prefix:4;					\
133         /* original flags used to compile the pattern, may differ */    \
134         /* from extflags in various ways */                             \
135         PERL_BITFIELD32 compflags:9;                                    \
136 	CV *qr_anoncv	/* the anon sub wrapped round qr/(?{..})/ */
137 
138 typedef struct regexp {
139 	_XPV_HEAD;
140 	_REGEXP_COMMON;
141 } regexp;
142 
143 #define RXp_PAREN_NAMES(rx)	((rx)->paren_names)
144 
145 /* used for high speed searches */
146 typedef struct re_scream_pos_data_s
147 {
148     char **scream_olds;		/* match pos */
149     I32 *scream_pos;		/* Internal iterator of scream. */
150 } re_scream_pos_data;
151 
152 /* regexp_engine structure. This is the dispatch table for regexes.
153  * Any regex engine implementation must be able to build one of these.
154  */
155 typedef struct regexp_engine {
156     REGEXP* (*comp) (pTHX_ SV * const pattern, U32 flags);
157     I32     (*exec) (pTHX_ REGEXP * const rx, char* stringarg, char* strend,
158                      char* strbeg, I32 minend, SV* screamer,
159                      void* data, U32 flags);
160     char*   (*intuit) (pTHX_ REGEXP * const rx, SV *sv, char *strpos,
161                        char *strend, const U32 flags,
162                        re_scream_pos_data *data);
163     SV*     (*checkstr) (pTHX_ REGEXP * const rx);
164     void    (*free) (pTHX_ REGEXP * const rx);
165     void    (*numbered_buff_FETCH) (pTHX_ REGEXP * const rx, const I32 paren,
166                                     SV * const sv);
167     void    (*numbered_buff_STORE) (pTHX_ REGEXP * const rx, const I32 paren,
168                                    SV const * const value);
169     I32     (*numbered_buff_LENGTH) (pTHX_ REGEXP * const rx, const SV * const sv,
170                                     const I32 paren);
171     SV*     (*named_buff) (pTHX_ REGEXP * const rx, SV * const key,
172                            SV * const value, const U32 flags);
173     SV*     (*named_buff_iter) (pTHX_ REGEXP * const rx, const SV * const lastkey,
174                                 const U32 flags);
175     SV*     (*qr_package)(pTHX_ REGEXP * const rx);
176 #ifdef USE_ITHREADS
177     void*   (*dupe) (pTHX_ REGEXP * const rx, CLONE_PARAMS *param);
178 #endif
179     REGEXP* (*op_comp) (pTHX_ SV ** const patternp, int pat_count,
180 		    OP *expr, const struct regexp_engine* eng,
181 		    REGEXP *VOL old_re,
182 		    bool *is_bare_re, U32 orig_rx_flags, U32 pm_flags);
183 } regexp_engine;
184 
185 /*
186   These are passed to the numbered capture variable callbacks as the
187   paren name. >= 1 is reserved for actual numbered captures, i.e. $1,
188   $2 etc.
189 */
190 #define RX_BUFF_IDX_CARET_PREMATCH  -5 /* ${^PREMATCH}  */
191 #define RX_BUFF_IDX_CARET_POSTMATCH -4 /* ${^POSTMATCH} */
192 #define RX_BUFF_IDX_CARET_FULLMATCH -3 /* ${^MATCH}     */
193 #define RX_BUFF_IDX_PREMATCH        -2 /* $` */
194 #define RX_BUFF_IDX_POSTMATCH       -1 /* $' */
195 #define RX_BUFF_IDX_FULLMATCH        0 /* $& */
196 
197 /*
198   Flags that are passed to the named_buff and named_buff_iter
199   callbacks above. Those routines are called from universal.c via the
200   Tie::Hash::NamedCapture interface for %+ and %- and the re::
201   functions in the same file.
202 */
203 
204 /* The Tie::Hash::NamedCapture operation this is part of, if any */
205 #define RXapif_FETCH     0x0001
206 #define RXapif_STORE     0x0002
207 #define RXapif_DELETE    0x0004
208 #define RXapif_CLEAR     0x0008
209 #define RXapif_EXISTS    0x0010
210 #define RXapif_SCALAR    0x0020
211 #define RXapif_FIRSTKEY  0x0040
212 #define RXapif_NEXTKEY   0x0080
213 
214 /* Whether %+ or %- is being operated on */
215 #define RXapif_ONE       0x0100 /* %+ */
216 #define RXapif_ALL       0x0200 /* %- */
217 
218 /* Whether this is being called from a re:: function */
219 #define RXapif_REGNAME         0x0400
220 #define RXapif_REGNAMES        0x0800
221 #define RXapif_REGNAMES_COUNT  0x1000
222 
223 /*
224 =head1 REGEXP Functions
225 
226 =for apidoc Am|REGEXP *|SvRX|SV *sv
227 
228 Convenience macro to get the REGEXP from a SV. This is approximately
229 equivalent to the following snippet:
230 
231     if (SvMAGICAL(sv))
232         mg_get(sv);
233     if (SvROK(sv))
234         sv = MUTABLE_SV(SvRV(sv));
235     if (SvTYPE(sv) == SVt_REGEXP)
236         return (REGEXP*) sv;
237 
238 NULL will be returned if a REGEXP* is not found.
239 
240 =for apidoc Am|bool|SvRXOK|SV* sv
241 
242 Returns a boolean indicating whether the SV (or the one it references)
243 is a REGEXP.
244 
245 If you want to do something with the REGEXP* later use SvRX instead
246 and check for NULL.
247 
248 =cut
249 */
250 
251 #define SvRX(sv)   (Perl_get_re_arg(aTHX_ sv))
252 #define SvRXOK(sv) (Perl_get_re_arg(aTHX_ sv) ? TRUE : FALSE)
253 
254 
255 /* Flags stored in regexp->extflags
256  * These are used by code external to the regexp engine
257  *
258  * Note that the flags whose names start with RXf_PMf_ are defined in
259  * op_reg_common.h, being copied from the parallel flags of op_pmflags
260  *
261  * NOTE: if you modify any RXf flags you should run regen.pl or
262  * regen/regcomp.pl so that regnodes.h is updated with the changes.
263  *
264  */
265 
266 #include "op_reg_common.h"
267 
268 #define RXf_PMf_STD_PMMOD	(RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_FOLD|RXf_PMf_EXTENDED)
269 
270 #define CASE_STD_PMMOD_FLAGS_PARSE_SET(pmfl)                        \
271     case IGNORE_PAT_MOD:    *(pmfl) |= RXf_PMf_FOLD;       break;   \
272     case MULTILINE_PAT_MOD: *(pmfl) |= RXf_PMf_MULTILINE;  break;   \
273     case SINGLE_PAT_MOD:    *(pmfl) |= RXf_PMf_SINGLELINE; break;   \
274     case XTENDED_PAT_MOD:   *(pmfl) |= RXf_PMf_EXTENDED;   break
275 
276 /* Note, includes charset ones, assumes 0 is the default for them */
277 #define STD_PMMOD_FLAGS_CLEAR(pmfl)                        \
278     *(pmfl) &= ~(RXf_PMf_FOLD|RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_EXTENDED|RXf_PMf_CHARSET)
279 
280 /* chars and strings used as regex pattern modifiers
281  * Singular is a 'c'har, plural is a "string"
282  *
283  * NOTE, KEEPCOPY was originally 'k', but was changed to 'p' for preserve
284  * for compatibility reasons with Regexp::Common which highjacked (?k:...)
285  * for its own uses. So 'k' is out as well.
286  */
287 #define DEFAULT_PAT_MOD      '^'    /* Short for all the default modifiers */
288 #define EXEC_PAT_MOD         'e'
289 #define KEEPCOPY_PAT_MOD     'p'
290 #define ONCE_PAT_MOD         'o'
291 #define GLOBAL_PAT_MOD       'g'
292 #define CONTINUE_PAT_MOD     'c'
293 #define MULTILINE_PAT_MOD    'm'
294 #define SINGLE_PAT_MOD       's'
295 #define IGNORE_PAT_MOD       'i'
296 #define XTENDED_PAT_MOD      'x'
297 #define NONDESTRUCT_PAT_MOD  'r'
298 #define LOCALE_PAT_MOD       'l'
299 #define UNICODE_PAT_MOD      'u'
300 #define DEPENDS_PAT_MOD      'd'
301 #define ASCII_RESTRICT_PAT_MOD 'a'
302 
303 #define ONCE_PAT_MODS        "o"
304 #define KEEPCOPY_PAT_MODS    "p"
305 #define EXEC_PAT_MODS        "e"
306 #define LOOP_PAT_MODS        "gc"
307 #define NONDESTRUCT_PAT_MODS "r"
308 #define LOCALE_PAT_MODS      "l"
309 #define UNICODE_PAT_MODS     "u"
310 #define DEPENDS_PAT_MODS     "d"
311 #define ASCII_RESTRICT_PAT_MODS "a"
312 #define ASCII_MORE_RESTRICT_PAT_MODS "aa"
313 
314 /* This string is expected by regcomp.c to be ordered so that the first
315  * character is the flag in bit RXf_PMf_STD_PMMOD_SHIFT of extflags; the next
316  * character is bit +1, etc. */
317 #define STD_PAT_MODS        "msix"
318 
319 #define CHARSET_PAT_MODS    ASCII_RESTRICT_PAT_MODS DEPENDS_PAT_MODS LOCALE_PAT_MODS UNICODE_PAT_MODS
320 
321 /* This string is expected by XS_re_regexp_pattern() in universal.c to be ordered
322  * so that the first character is the flag in bit RXf_PMf_STD_PMMOD_SHIFT of
323  * extflags; the next character is in bit +1, etc. */
324 #define INT_PAT_MODS    STD_PAT_MODS    KEEPCOPY_PAT_MODS
325 
326 #define EXT_PAT_MODS    ONCE_PAT_MODS   KEEPCOPY_PAT_MODS
327 #define QR_PAT_MODS     STD_PAT_MODS    EXT_PAT_MODS	   CHARSET_PAT_MODS
328 #define M_PAT_MODS      QR_PAT_MODS     LOOP_PAT_MODS
329 #define S_PAT_MODS      M_PAT_MODS      EXEC_PAT_MODS      NONDESTRUCT_PAT_MODS
330 
331 /*
332  * NOTE: if you modify any RXf flags you should run regen.pl or
333  * regen/regcomp.pl so that regnodes.h is updated with the changes.
334  *
335  */
336 
337 /* Leave some space, so future bit allocations can go either in the shared or
338  * unshared area without affecting binary compatibility */
339 #define RXf_BASE_SHIFT (_RXf_PMf_SHIFT_NEXT)
340 
341 /*
342   Set in Perl_pmruntime if op_flags & OPf_SPECIAL, i.e. split. Will
343   be used by regex engines to check whether they should set
344   RXf_SKIPWHITE
345 */
346 #define RXf_SPLIT                (1<<(RXf_BASE_SHIFT-1))
347 #if RXf_SPLIT != RXf_PMf_SPLIT
348 #   error "RXf_SPLIT does not match RXf_PMf_SPLIT"
349 #endif
350 
351 /* Manually decorate this function with gcc-style attributes just to
352  * avoid having to restructure the header files and their called order,
353  * as proto.h would have to be included before this file, and isn't */
354 
355 PERL_STATIC_INLINE const char *
356 get_regex_charset_name(const U32 flags, STRLEN* const lenp)
357     __attribute__warn_unused_result__;
358 
359 #define MAX_CHARSET_NAME_LENGTH 2
360 
361 PERL_STATIC_INLINE const char *
362 get_regex_charset_name(const U32 flags, STRLEN* const lenp)
363 {
364     /* Returns a string that corresponds to the name of the regex character set
365      * given by 'flags', and *lenp is set the length of that string, which
366      * cannot exceed MAX_CHARSET_NAME_LENGTH characters */
367 
368     *lenp = 1;
369     switch (get_regex_charset(flags)) {
370         case REGEX_DEPENDS_CHARSET: return DEPENDS_PAT_MODS;
371         case REGEX_LOCALE_CHARSET:  return LOCALE_PAT_MODS;
372         case REGEX_UNICODE_CHARSET: return UNICODE_PAT_MODS;
373 	case REGEX_ASCII_RESTRICTED_CHARSET: return ASCII_RESTRICT_PAT_MODS;
374 	case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
375 	    *lenp = 2;
376 	    return ASCII_MORE_RESTRICT_PAT_MODS;
377         default:
378 	    return "?";	    /* Unknown */
379     }
380 }
381 
382 /* Anchor and GPOS related stuff */
383 #define RXf_ANCH_BOL    	(1<<(RXf_BASE_SHIFT+0))
384 #define RXf_ANCH_MBOL   	(1<<(RXf_BASE_SHIFT+1))
385 #define RXf_ANCH_SBOL   	(1<<(RXf_BASE_SHIFT+2))
386 #define RXf_ANCH_GPOS   	(1<<(RXf_BASE_SHIFT+3))
387 #define RXf_GPOS_SEEN   	(1<<(RXf_BASE_SHIFT+4))
388 #define RXf_GPOS_FLOAT  	(1<<(RXf_BASE_SHIFT+5))
389 /* two bits here */
390 #define RXf_ANCH        	(RXf_ANCH_BOL|RXf_ANCH_MBOL|RXf_ANCH_GPOS|RXf_ANCH_SBOL)
391 #define RXf_GPOS_CHECK          (RXf_GPOS_SEEN|RXf_ANCH_GPOS)
392 #define RXf_ANCH_SINGLE         (RXf_ANCH_SBOL|RXf_ANCH_GPOS)
393 
394 /* What we have seen */
395 #define RXf_NO_INPLACE_SUBST    (1<<(RXf_BASE_SHIFT+6))
396 #define RXf_EVAL_SEEN   	(1<<(RXf_BASE_SHIFT+7))
397 #define RXf_CANY_SEEN   	(1<<(RXf_BASE_SHIFT+8))
398 
399 /* Special */
400 #define RXf_NOSCAN      	(1<<(RXf_BASE_SHIFT+9))
401 #define RXf_CHECK_ALL   	(1<<(RXf_BASE_SHIFT+10))
402 
403 /* UTF8 related */
404 #define RXf_MATCH_UTF8  	(1<<(RXf_BASE_SHIFT+11))
405 
406 /* Intuit related */
407 #define RXf_USE_INTUIT_NOML	(1<<(RXf_BASE_SHIFT+12))
408 #define RXf_USE_INTUIT_ML	(1<<(RXf_BASE_SHIFT+13))
409 #define RXf_INTUIT_TAIL 	(1<<(RXf_BASE_SHIFT+14))
410 #define RXf_USE_INTUIT		(RXf_USE_INTUIT_NOML|RXf_USE_INTUIT_ML)
411 
412 /* Copy and tainted info */
413 #define RXf_COPY_DONE   	(1<<(RXf_BASE_SHIFT+16))
414 
415 /* during execution: pattern temporarily tainted by executing locale ops;
416  * post-execution: $1 et al are tainted */
417 #define RXf_TAINTED_SEEN	(1<<(RXf_BASE_SHIFT+17))
418 /* this pattern was tainted during compilation */
419 #define RXf_TAINTED		(1<<(RXf_BASE_SHIFT+18))
420 
421 /* Flags indicating special patterns */
422 #define RXf_START_ONLY		(1<<(RXf_BASE_SHIFT+19)) /* Pattern is /^/ */
423 #define RXf_SKIPWHITE                (1<<(RXf_BASE_SHIFT+20)) /* Pattern is for a split " " */
424 #define RXf_WHITE		(1<<(RXf_BASE_SHIFT+21)) /* Pattern is /\s+/ */
425 #define RXf_NULL		(1U<<(RXf_BASE_SHIFT+22)) /* Pattern is // */
426 #if RXf_BASE_SHIFT+22 > 31
427 #   error Too many RXf_PMf bits used.  See regnodes.h for any spare in middle
428 #endif
429 
430 /*
431  * NOTE: if you modify any RXf flags you should run regen.pl or
432  * regen/regcomp.pl so that regnodes.h is updated with the changes.
433  *
434  */
435 
436 #if NO_TAINT_SUPPORT
437 #   define RX_ISTAINTED(prog)    0
438 #   define RX_TAINT_on(prog)     NOOP
439 #   define RXp_MATCH_TAINTED(prog) 0
440 #   define RX_MATCH_TAINTED(prog)  0
441 #   define RXp_MATCH_TAINTED_on(prog) NOOP
442 #   define RX_MATCH_TAINTED_on(prog)  NOOP
443 #   define RX_MATCH_TAINTED_off(prog) NOOP
444 #else
445 #   define RX_ISTAINTED(prog)    (RX_EXTFLAGS(prog) & RXf_TAINTED)
446 #   define RX_TAINT_on(prog)     (RX_EXTFLAGS(prog) |= RXf_TAINTED)
447 #   define RXp_MATCH_TAINTED(prog)    (RXp_EXTFLAGS(prog) & RXf_TAINTED_SEEN)
448 #   define RX_MATCH_TAINTED(prog)     (RX_EXTFLAGS(prog)  & RXf_TAINTED_SEEN)
449 #   define RXp_MATCH_TAINTED_on(prog) (RXp_EXTFLAGS(prog) |= RXf_TAINTED_SEEN)
450 #   define RX_MATCH_TAINTED_on(prog)  (RX_EXTFLAGS(prog)  |= RXf_TAINTED_SEEN)
451 #   define RX_MATCH_TAINTED_off(prog) (RX_EXTFLAGS(prog)  &= ~RXf_TAINTED_SEEN)
452 #endif
453 
454 #define RX_HAS_CUTGROUP(prog) ((prog)->intflags & PREGf_CUTGROUP_SEEN)
455 #define RX_MATCH_TAINTED_set(prog, t) ((t) \
456 				       ? RX_MATCH_TAINTED_on(prog) \
457 				       : RX_MATCH_TAINTED_off(prog))
458 
459 #define RXp_MATCH_COPIED(prog)		(RXp_EXTFLAGS(prog) & RXf_COPY_DONE)
460 #define RX_MATCH_COPIED(prog)		(RX_EXTFLAGS(prog) & RXf_COPY_DONE)
461 #define RXp_MATCH_COPIED_on(prog)	(RXp_EXTFLAGS(prog) |= RXf_COPY_DONE)
462 #define RX_MATCH_COPIED_on(prog)	(RX_EXTFLAGS(prog) |= RXf_COPY_DONE)
463 #define RXp_MATCH_COPIED_off(prog)	(RXp_EXTFLAGS(prog) &= ~RXf_COPY_DONE)
464 #define RX_MATCH_COPIED_off(prog)	(RX_EXTFLAGS(prog) &= ~RXf_COPY_DONE)
465 #define RX_MATCH_COPIED_set(prog,t)	((t) \
466 					 ? RX_MATCH_COPIED_on(prog) \
467 					 : RX_MATCH_COPIED_off(prog))
468 
469 #define RXp_EXTFLAGS(rx)	((rx)->extflags)
470 #define RXp_COMPFLAGS(rx)        ((rx)->compflags)
471 
472 /* For source compatibility. We used to store these explicitly.  */
473 #define RX_PRECOMP(prog)	(RX_WRAPPED(prog) + ReANY(prog)->pre_prefix)
474 #define RX_PRECOMP_const(prog)	(RX_WRAPPED_const(prog) + ReANY(prog)->pre_prefix)
475 /* FIXME? Are we hardcoding too much here and constraining plugin extension
476    writers? Specifically, the value 1 assumes that the wrapped version always
477    has exactly one character at the end, a ')'. Will that always be true?  */
478 #define RX_PRELEN(prog)		(RX_WRAPLEN(prog) - ReANY(prog)->pre_prefix - 1)
479 #define RX_WRAPPED(prog)	ReANY(prog)->xpv_len_u.xpvlenu_pv
480 #define RX_WRAPPED_const(prog)	((const char *)RX_WRAPPED(prog))
481 #define RX_WRAPLEN(prog)	SvCUR(prog)
482 #define RX_CHECK_SUBSTR(prog)	(ReANY(prog)->check_substr)
483 #define RX_REFCNT(prog)		SvREFCNT(prog)
484 #define RX_EXTFLAGS(prog)	RXp_EXTFLAGS(ReANY(prog))
485 #define RX_COMPFLAGS(prog)        RXp_COMPFLAGS(ReANY(prog))
486 #define RX_ENGINE(prog)		(ReANY(prog)->engine)
487 #define RX_SUBBEG(prog)		(ReANY(prog)->subbeg)
488 #define RX_SUBOFFSET(prog)	(ReANY(prog)->suboffset)
489 #define RX_SUBCOFFSET(prog)	(ReANY(prog)->subcoffset)
490 #define RX_OFFS(prog)		(ReANY(prog)->offs)
491 #define RX_NPARENS(prog)	(ReANY(prog)->nparens)
492 #define RX_SUBLEN(prog)		(ReANY(prog)->sublen)
493 #define RX_MINLEN(prog)		(ReANY(prog)->minlen)
494 #define RX_MINLENRET(prog)	(ReANY(prog)->minlenret)
495 #define RX_GOFS(prog)		(ReANY(prog)->gofs)
496 #define RX_LASTPAREN(prog)	(ReANY(prog)->lastparen)
497 #define RX_LASTCLOSEPAREN(prog)	(ReANY(prog)->lastcloseparen)
498 #define RX_SAVED_COPY(prog)	(ReANY(prog)->saved_copy)
499 
500 #endif /* PLUGGABLE_RE_EXTENSION */
501 
502 /* Stuff that needs to be included in the pluggable extension goes below here */
503 
504 #ifdef PERL_ANY_COW
505 #define RX_MATCH_COPY_FREE(rx) \
506 	STMT_START {if (RX_SAVED_COPY(rx)) { \
507 	    SV_CHECK_THINKFIRST_COW_DROP(RX_SAVED_COPY(rx)); \
508 	} \
509 	if (RX_MATCH_COPIED(rx)) { \
510 	    Safefree(RX_SUBBEG(rx)); \
511 	    RX_MATCH_COPIED_off(rx); \
512 	}} STMT_END
513 #else
514 #define RX_MATCH_COPY_FREE(rx) \
515 	STMT_START {if (RX_MATCH_COPIED(rx)) { \
516 	    Safefree(RX_SUBBEG(rx)); \
517 	    RX_MATCH_COPIED_off(rx); \
518 	}} STMT_END
519 #endif
520 
521 #define RXp_MATCH_UTF8(prog)		(RXp_EXTFLAGS(prog) & RXf_MATCH_UTF8)
522 #define RX_MATCH_UTF8(prog)		(RX_EXTFLAGS(prog) & RXf_MATCH_UTF8)
523 #define RX_MATCH_UTF8_on(prog)		(RX_EXTFLAGS(prog) |= RXf_MATCH_UTF8)
524 #define RX_MATCH_UTF8_off(prog)		(RX_EXTFLAGS(prog) &= ~RXf_MATCH_UTF8)
525 #define RX_MATCH_UTF8_set(prog, t)	((t) \
526 			? (RX_MATCH_UTF8_on(prog), (PL_reg_match_utf8 = 1)) \
527 			: (RX_MATCH_UTF8_off(prog), (PL_reg_match_utf8 = 0)))
528 
529 /* Whether the pattern stored at RX_WRAPPED is in UTF-8  */
530 #define RX_UTF8(prog)			SvUTF8(prog)
531 
532 #define REXEC_COPY_STR	0x01		/* Need to copy the string. */
533 #define REXEC_CHECKED	0x02		/* check_substr already checked. */
534 #define REXEC_SCREAM	0x04		/* use scream table. */
535 #define REXEC_IGNOREPOS	0x08		/* \G matches at start. */
536 #define REXEC_NOT_FIRST	0x10		/* This is another iteration of //g. */
537                                     /* under REXEC_COPY_STR, it's ok for the
538                                      * engine (modulo PL_sawamperand etc)
539                                      * to skip copying ... */
540 #define REXEC_COPY_SKIP_PRE  0x20   /* ...the $` part of the string, or */
541 #define REXEC_COPY_SKIP_POST 0x40   /* ...the $' part of the string */
542 
543 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
544 #  define ReREFCNT_inc(re)						\
545     ({									\
546 	/* This is here to generate a casting warning if incorrect.  */	\
547 	REGEXP *const _rerefcnt_inc = (re);				\
548 	assert(SvTYPE(_rerefcnt_inc) == SVt_REGEXP);			\
549 	SvREFCNT_inc(_rerefcnt_inc);					\
550 	_rerefcnt_inc;							\
551     })
552 #  define ReREFCNT_dec(re)						\
553     ({									\
554 	/* This is here to generate a casting warning if incorrect.  */	\
555 	REGEXP *const _rerefcnt_dec = (re);				\
556 	SvREFCNT_dec(_rerefcnt_dec);					\
557     })
558 #else
559 #  define ReREFCNT_dec(re)	SvREFCNT_dec(re)
560 #  define ReREFCNT_inc(re)	((REGEXP *) SvREFCNT_inc(re))
561 #endif
562 #define ReANY(re)		S_ReANY((const REGEXP *)(re))
563 
564 /* FIXME for plugins. */
565 
566 #define FBMcf_TAIL_DOLLAR	1
567 #define FBMcf_TAIL_DOLLARM	2
568 #define FBMcf_TAIL_Z		4
569 #define FBMcf_TAIL_z		8
570 #define FBMcf_TAIL		(FBMcf_TAIL_DOLLAR|FBMcf_TAIL_DOLLARM|FBMcf_TAIL_Z|FBMcf_TAIL_z)
571 
572 #define FBMrf_MULTILINE	1
573 
574 /* some basic information about the current match that is created by
575  * Perl_regexec_flags and then passed to regtry(), regmatch() etc */
576 
577 typedef struct {
578     REGEXP *prog;
579     char *bol;
580     char *till;
581     SV *sv;
582     char *ganch;
583     char *cutpoint;
584     bool is_utf8_pat;
585     bool warned; /* we have issued a recursion warning; no need for more */
586 } regmatch_info;
587 
588 
589 /* structures for holding and saving the state maintained by regmatch() */
590 
591 #ifndef MAX_RECURSE_EVAL_NOCHANGE_DEPTH
592 #define MAX_RECURSE_EVAL_NOCHANGE_DEPTH 1000
593 #endif
594 
595 typedef I32 CHECKPOINT;
596 
597 typedef struct regmatch_state {
598     int resume_state;		/* where to jump to on return */
599     char *locinput;		/* where to backtrack in string on failure */
600 
601     union {
602 
603 	/* this is a fake union member that matches the first element
604 	 * of each member that needs to store positive backtrack
605 	 * information */
606 	struct {
607 	    struct regmatch_state *prev_yes_state;
608 	} yes;
609 
610         /* branchlike members */
611         /* this is a fake union member that matches the first elements
612          * of each member that needs to behave like a branch */
613         struct {
614 	    /* this first element must match u.yes */
615 	    struct regmatch_state *prev_yes_state;
616 	    U32 lastparen;
617 	    U32 lastcloseparen;
618 	    CHECKPOINT cp;
619 
620         } branchlike;
621 
622 	struct {
623 	    /* the first elements must match u.branchlike */
624 	    struct regmatch_state *prev_yes_state;
625 	    U32 lastparen;
626 	    U32 lastcloseparen;
627 	    CHECKPOINT cp;
628 
629 	    regnode *next_branch; /* next branch node */
630 	} branch;
631 
632 	struct {
633 	    /* the first elements must match u.branchlike */
634 	    struct regmatch_state *prev_yes_state;
635 	    U32 lastparen;
636 	    U32 lastcloseparen;
637 	    CHECKPOINT cp;
638 
639 	    U32		accepted; /* how many accepting states left */
640 	    bool	longfold;/* saw a fold with a 1->n char mapping */
641 	    U16         *jump;  /* positive offsets from me */
642 	    regnode	*me;	/* Which node am I - needed for jump tries*/
643 	    U8		*firstpos;/* pos in string of first trie match */
644 	    U32		firstchars;/* len in chars of firstpos from start */
645 	    U16		nextword;/* next word to try */
646 	    U16		topword; /* longest accepted word */
647 	} trie;
648 
649         /* special types - these members are used to store state for special
650            regops like eval, if/then, lookaround and the markpoint state */
651 	struct {
652 	    /* this first element must match u.yes */
653 	    struct regmatch_state *prev_yes_state;
654 	    struct regmatch_state *prev_eval;
655 	    struct regmatch_state *prev_curlyx;
656 	    REGEXP	*prev_rex;
657 	    bool	saved_utf8_pat; /* saved copy of is_utf8_pat */
658 	    CHECKPOINT	cp;	/* remember current savestack indexes */
659 	    CHECKPOINT	lastcp;
660 	    U32        close_paren; /* which close bracket is our end */
661 	    regnode	*B;	/* the node following us  */
662 	} eval;
663 
664 	struct {
665 	    /* this first element must match u.yes */
666 	    struct regmatch_state *prev_yes_state;
667 	    I32 wanted;
668 	    I32 logical;	/* saved copy of 'logical' var */
669 	    regnode  *me; /* the IFMATCH/SUSPEND/UNLESSM node  */
670 	} ifmatch; /* and SUSPEND/UNLESSM */
671 
672 	struct {
673 	    /* this first element must match u.yes */
674 	    struct regmatch_state *prev_yes_state;
675 	    struct regmatch_state *prev_mark;
676 	    SV* mark_name;
677 	    char *mark_loc;
678 	} mark;
679 
680 	struct {
681 	    int val;
682 	} keeper;
683 
684         /* quantifiers - these members are used for storing state for
685            for the regops used to implement quantifiers */
686 	struct {
687 	    /* this first element must match u.yes */
688 	    struct regmatch_state *prev_yes_state;
689 	    struct regmatch_state *prev_curlyx; /* previous cur_curlyx */
690 	    regnode	*me;	/* the CURLYX node  */
691 	    regnode	*B;	/* the B node in /A*B/  */
692 	    CHECKPOINT	cp;	/* remember current savestack index */
693 	    bool	minmod;
694 	    int		parenfloor;/* how far back to strip paren data */
695 
696 	    /* these two are modified by WHILEM */
697 	    int		count;	/* how many instances of A we've matched */
698 	    char	*lastloc;/* where previous A matched (0-len detect) */
699 	} curlyx;
700 
701 	struct {
702 	    /* this first element must match u.yes */
703 	    struct regmatch_state *prev_yes_state;
704 	    struct regmatch_state *save_curlyx;
705 	    CHECKPOINT	cp;	/* remember current savestack indexes */
706 	    CHECKPOINT	lastcp;
707 	    char	*save_lastloc;	/* previous curlyx.lastloc */
708 	    I32		cache_offset;
709 	    I32		cache_mask;
710 	} whilem;
711 
712 	struct {
713 	    /* this first element must match u.yes */
714 	    struct regmatch_state *prev_yes_state;
715 	    int c1, c2;		/* case fold search */
716 	    CHECKPOINT cp;
717 	    U32 lastparen;
718 	    U32 lastcloseparen;
719 	    I32 alen;		/* length of first-matched A string */
720 	    I32 count;
721 	    bool minmod;
722 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
723 	    regnode *me;	/* the curlym node */
724             U8 c1_utf8[UTF8_MAXBYTES+1];  /* */
725             U8 c2_utf8[UTF8_MAXBYTES+1];
726 	} curlym;
727 
728 	struct {
729 	    U32 paren;
730 	    CHECKPOINT cp;
731 	    U32 lastparen;
732 	    U32 lastcloseparen;
733 	    int c1, c2;		/* case fold search */
734 	    char *maxpos;	/* highest possible point in string to match */
735 	    char *oldloc;	/* the previous locinput */
736 	    int count;
737 	    int min, max;	/* {m,n} */
738 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
739             U8 c1_utf8[UTF8_MAXBYTES+1];  /* */
740             U8 c2_utf8[UTF8_MAXBYTES+1];
741 	} curly; /* and CURLYN/PLUS/STAR */
742 
743     } u;
744 } regmatch_state;
745 
746 /* how many regmatch_state structs to allocate as a single slab.
747  * We do it in 4K blocks for efficiency. The "3" is 2 for the next/prev
748  * pointers, plus 1 for any mythical malloc overhead. */
749 
750 #define PERL_REGMATCH_SLAB_SLOTS \
751     ((4096 - 3 * sizeof (void*)) / sizeof(regmatch_state))
752 
753 typedef struct regmatch_slab {
754     regmatch_state states[PERL_REGMATCH_SLAB_SLOTS];
755     struct regmatch_slab *prev, *next;
756 } regmatch_slab;
757 
758 #define PL_bostr		PL_reg_state.re_state_bostr
759 #define PL_regeol		PL_reg_state.re_state_regeol
760 #define PL_reg_match_utf8	PL_reg_state.re_state_reg_match_utf8
761 #define PL_reg_magic		PL_reg_state.re_state_reg_magic
762 #define PL_reg_oldpos		PL_reg_state.re_state_reg_oldpos
763 #define PL_reg_oldcurpm		PL_reg_state.re_state_reg_oldcurpm
764 #define PL_reg_curpm		PL_reg_state.re_state_reg_curpm
765 #define PL_reg_oldsaved		PL_reg_state.re_state_reg_oldsaved
766 #define PL_reg_oldsavedlen	PL_reg_state.re_state_reg_oldsavedlen
767 #define PL_reg_oldsavedoffset	PL_reg_state.re_state_reg_oldsavedoffset
768 #define PL_reg_oldsavedcoffset	PL_reg_state.re_state_reg_oldsavedcoffset
769 #define PL_reg_maxiter		PL_reg_state.re_state_reg_maxiter
770 #define PL_reg_leftiter		PL_reg_state.re_state_reg_leftiter
771 #define PL_reg_poscache		PL_reg_state.re_state_reg_poscache
772 #define PL_reg_poscache_size	PL_reg_state.re_state_reg_poscache_size
773 #define PL_reg_starttry		PL_reg_state.re_state_reg_starttry
774 #define PL_nrs			PL_reg_state.re_state_nrs
775 
776 struct re_save_state {
777     bool re_state_eval_setup_done;	/* from regexec.c */
778     bool re_state_reg_match_utf8;	/* from regexec.c */
779     /* Space for U8 */
780     I32 re_state_reg_oldpos;		/* from regexec.c */
781     I32 re_state_reg_maxiter;		/* max wait until caching pos */
782     I32 re_state_reg_leftiter;		/* wait until caching pos */
783     char *re_state_bostr;
784     char *re_state_regeol;		/* End of input, for $ check. */
785     MAGIC *re_state_reg_magic;		/* from regexec.c */
786     PMOP *re_state_reg_oldcurpm;	/* from regexec.c */
787     PMOP *re_state_reg_curpm;		/* from regexec.c */
788     char *re_state_reg_oldsaved;	/* old saved substr during match */
789     STRLEN re_state_reg_oldsavedlen;	/* old length of saved substr during match */
790     STRLEN re_state_reg_oldsavedoffset;	/* old offset of saved substr during match */
791     STRLEN re_state_reg_oldsavedcoffset;/* old coffset of saved substr during match */
792     STRLEN re_state_reg_poscache_size;	/* size of pos cache of WHILEM */
793     char *re_state_reg_poscache;	/* cache of pos of WHILEM */
794     char *re_state_reg_starttry;	/* from regexec.c */
795 #ifdef PERL_ANY_COW
796     SV *re_state_nrs;			/* was placeholder: unused since 5.8.0 (5.7.2 patch #12027 for bug ID 20010815.012). Used to save rx->saved_copy */
797 #endif
798 };
799 
800 #define SAVESTACK_ALLOC_FOR_RE_SAVE_STATE \
801 	(1 + ((sizeof(struct re_save_state) - 1) / sizeof(*PL_savestack)))
802 
803 /*
804  * Local variables:
805  * c-indentation-style: bsd
806  * c-basic-offset: 4
807  * indent-tabs-mode: nil
808  * End:
809  *
810  * ex: set ts=8 sts=4 sw=4 et:
811  */
812