1 /*
2 * Extended regular expression matching and search library,
3 * version 0.12.
4 * (Implements POSIX draft P1003.2/D11.2, except for some of the
5 * internationalization features.)
6 *
7 * This code will be used by Epos only if the operating system offers
8 * no regular expressions as a standard library.
9 *
10 * rx.c is (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
11 *
12 * This file is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
16 *
17 * The GNU C Library is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * Library General Public License in libs/regex/COPYING for more details.
21 *
22 */
23
24 #define REGEX_MALLOC
25
26 /* AIX requires this to be the first thing in the file. */
27 #if defined (_AIX) && !defined (REGEX_MALLOC)
28 #pragma alloca
29 #endif
30
31 #undef _GNU_SOURCE
32 #define _GNU_SOURCE
33
34 #ifdef DEBUG
35 #undef DEBUG
36 #endif
37
38 #include "config.h"
39
40 #ifdef BROKEN_LOCALE
isupper(int c)41 int isupper(int c) { return 0; }
isdigit(int c)42 int isdigit(int c) { return c <= '9' && c >= '0'; }
43 #endif
44
45
46
47 #ifndef const
48 #define const /* Visual C++ for example dislikes free()ing const data */
49 #endif
50
51 #ifndef __STDC__
52 #define __STDC__ 1
53 #endif
54
55 #if defined(STDC_HEADERS) && !defined(emacs)
56 #include <stddef.h>
57 #else
58 /* We need this for `rx.h', and perhaps for the Emacs include files. */
59 #include <sys/types.h>
60 #endif
61
62 /* For platform which support the ISO C amendement 1 functionality we
63 support user defined character classes. */
64 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
65 # include <wctype.h>
66 # include <wchar.h>
67 #endif
68
69 /* This is for other GNU distributions with internationalized messages. */
70 #if HAVE_LIBINTL_H || defined (_LIBC)
71 # include <libintl.h>
72 #else
73 # define gettext(msgid) (msgid)
74 #endif
75
76 #ifndef gettext_noop
77 /* This define is so xgettext can find the internationalizable
78 strings. */
79 #define gettext_noop(String) String
80 #endif
81
82 /* The `emacs' switch turns on certain matching commands
83 that make sense only in Emacs. */
84 #ifdef emacs
85
86 #include "lisp.h"
87 #include "buffer.h"
88 #include "syntax.h"
89
90 #else /* not emacs */
91
92 /* If we are not linking with Emacs proper,
93 we can't use the relocating allocator
94 even if config.h says that we can. */
95 #undef REL_ALLOC
96
97 #if defined (STDC_HEADERS) || defined (_LIBC)
98 #include <stdlib.h>
99 #else
100 char *malloc ();
101 char *realloc ();
102 void free(void *ptr);
103 #endif
104
call_abort(void)105 static void call_abort(void)
106 {
107 #ifdef HAVE_ABORT
108 abort();
109 #else
110 while (1) ;
111 #endif
112 }
113
114 /* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
115 If nothing else has been done, use the method below. */
116 #ifdef INHIBIT_STRING_HEADER
117 #if !(defined (HAVE_BZERO) && defined (HAVE_BCOPY))
118 #if !defined (bzero) && !defined (bcopy)
119 #undef INHIBIT_STRING_HEADER
120 #endif
121 #endif
122 #endif
123
124 /* This is the normal way of making sure we have a bcopy and a bzero.
125 This is used in most programs--a few other programs avoid this
126 by defining INHIBIT_STRING_HEADER. */
127 #ifndef INHIBIT_STRING_HEADER
128 #if defined (HAVE_STRING_H) || defined (STDC_HEADERS) || defined (_LIBC)
129 #include <string.h>
130 #ifndef bcmp
131 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
132 #endif
133 #ifndef bcopy
134 #define bcopy(s, d, n) memcpy ((d), (s), (n))
135 #endif
136 #ifndef bzero
137 #define bzero(s, n) memset ((s), 0, (n))
138 #endif
139 #else
140 #include <strings.h>
141 #endif
142 #endif
143
144 /* Define the syntax stuff for \<, \>, etc. */
145
146 /* This must be nonzero for the wordchar and notwordchar pattern
147 commands in re_match_2. */
148 #ifndef Sword
149 #define Sword 1
150 #endif
151
152 #ifdef SWITCH_ENUM_BUG
153 #define SWITCH_ENUM_CAST(x) ((int)(x))
154 #else
155 #define SWITCH_ENUM_CAST(x) (x)
156 #endif
157
158 #ifdef SYNTAX_TABLE
159
160 extern char *re_syntax_table;
161
162 #else /* not SYNTAX_TABLE */
163
164 /* How many characters in the character set. */
165 #define CHAR_SET_SIZE 256
166
167 static char re_syntax_table[CHAR_SET_SIZE];
168
169 static void
init_syntax_once()170 init_syntax_once ()
171 {
172 register int c;
173 static int done = 0;
174
175 if (done)
176 return;
177
178 bzero (re_syntax_table, sizeof re_syntax_table);
179
180 for (c = 'a'; c <= 'z'; c++)
181 re_syntax_table[c] = Sword;
182
183 for (c = 'A'; c <= 'Z'; c++)
184 re_syntax_table[c] = Sword;
185
186 for (c = '0'; c <= '9'; c++)
187 re_syntax_table[c] = Sword;
188
189 re_syntax_table['_'] = Sword;
190
191 done = 1;
192 }
193
194 #endif /* not SYNTAX_TABLE */
195
196 #define SYNTAX(c) re_syntax_table[c]
197
198 #endif /* not emacs */
199
200 /* Get the interface, including the syntax bits. */
201 #include "rx.h"
202
203 /* isalpha etc. are used for the character classes. */
204 #include <ctype.h>
205
206 /* Jim Meyering writes:
207
208 "... Some ctype macros are valid only for character codes that
209 isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
210 using /bin/cc or gcc but without giving an ansi option). So, all
211 ctype uses should be through macros like ISPRINT... If
212 STDC_HEADERS is defined, then autoconf has verified that the ctype
213 macros don't need to be guarded with references to isascii. ...
214 Defining isascii to 1 should let any compiler worth its salt
215 eliminate the && through constant folding." */
216
217 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
218 #define ISASCII(c) 1
219 #else
220 #define ISASCII(c) isascii(c)
221 #endif
222
223 #ifdef isblank
224 #define ISBLANK(c) (ISASCII (c) && isblank (c))
225 #else
226 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
227 #endif
228 #ifdef isgraph
229 #define ISGRAPH(c) (ISASCII (c) && isgraph (c))
230 #else
231 #define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
232 #endif
233
234 #define ISPRINT(c) (ISASCII (c) && isprint (c))
235 #define ISDIGIT(c) (ISASCII (c) && isdigit (c))
236 #define ISALNUM(c) (ISASCII (c) && isalnum (c))
237 #define ISALPHA(c) (ISASCII (c) && isalpha (c))
238 #define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
239 #define ISLOWER(c) (ISASCII (c) && islower (c))
240 #define ISPUNCT(c) (ISASCII (c) && ispunct (c))
241 #define ISSPACE(c) (ISASCII (c) && isspace (c))
242 #define ISUPPER(c) (ISASCII (c) && isupper (c))
243 #define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
244
245 #ifndef NULL
246 #define NULL (void *)0
247 #endif
248
249 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
250 since ours (we hope) works properly with all combinations of
251 machines, compilers, `char' and `unsigned char' argument types.
252 (Per Bothner suggested the basic approach.) */
253 #undef SIGN_EXTEND_CHAR
254 #if __STDC__
255 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
256 #else /* not __STDC__ */
257 /* As in Harbison and Steele. */
258 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
259 #endif
260
261 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
262 use `alloca' instead of `malloc'. This is because using malloc in
263 re_search* or re_match* could cause memory leaks when C-g is used in
264 Emacs; also, malloc is slower and causes storage fragmentation. On
265 the other hand, malloc is more portable, and easier to debug.
266
267 Because we sometimes use alloca, some routines have to be macros,
268 not functions -- `alloca'-allocated space disappears at the end of the
269 function it is called in. */
270
271 #ifdef REGEX_MALLOC
272
273 #define REGEX_ALLOCATE malloc
274 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
275 #define REGEX_FREE free
276
277 #else /* not REGEX_MALLOC */
278
279 /* Emacs already defines alloca, sometimes. */
280 #ifndef alloca
281
282 /* Make alloca work the best possible way. */
283 #ifdef __GNUC__
284 #define alloca __builtin_alloca
285 #else /* not __GNUC__ */
286 #if HAVE_ALLOCA_H
287 #include <alloca.h>
288 #else /* not __GNUC__ or HAVE_ALLOCA_H */
289 #if 0 /* It is a bad idea to declare alloca. We always cast the result. */
290 #ifndef _AIX /* Already did AIX, up at the top. */
291 char *alloca ();
292 #endif /* not _AIX */
293 #endif
294 #endif /* not HAVE_ALLOCA_H */
295 #endif /* not __GNUC__ */
296
297 #endif /* not alloca */
298
299 #define REGEX_ALLOCATE alloca
300
301 /* Assumes a `char *destination' variable. */
302 #define REGEX_REALLOCATE(source, osize, nsize) \
303 (destination = (char *) alloca (nsize), \
304 bcopy (source, destination, osize), \
305 destination)
306
307 /* No need to do anything to free, after alloca. */
308 #define REGEX_FREE(arg) ((void)0) /* Do nothing! But inhibit gcc warning. */
309
310 #endif /* not REGEX_MALLOC */
311
312 /* Define how to allocate the failure stack. */
313
314 #if defined (REL_ALLOC) && defined (REGEX_MALLOC)
315
316 #define REGEX_ALLOCATE_STACK(size) \
317 r_alloc (&failure_stack_ptr, (size))
318 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
319 r_re_alloc (&failure_stack_ptr, (nsize))
320 #define REGEX_FREE_STACK(ptr) \
321 r_alloc_free (&failure_stack_ptr)
322
323 #else /* not using relocating allocator */
324
325 #ifdef REGEX_MALLOC
326
327 #define REGEX_ALLOCATE_STACK malloc
328 #define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
329 #define REGEX_FREE_STACK free
330
331 #else /* not REGEX_MALLOC */
332
333 #define REGEX_ALLOCATE_STACK alloca
334
335 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
336 REGEX_REALLOCATE (source, osize, nsize)
337 /* No need to explicitly free anything. */
338 #define REGEX_FREE_STACK(arg)
339
340 #endif /* not REGEX_MALLOC */
341 #endif /* not using relocating allocator */
342
343
344 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
345 `string1' or just past its end. This works if PTR is NULL, which is
346 a good thing. */
347 #define FIRST_STRING_P(ptr) \
348 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
349
350 /* (Re)Allocate N items of type T using malloc, or fail. */
351 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
352 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
353 #define RETALLOC_IF(addr, n, t) \
354 if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
355 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
356
357 #define BYTEWIDTH 8 /* In bits. */
358
359 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
360
361 #undef MAX
362 #undef MIN
363 #define MAX(a, b) ((a) > (b) ? (a) : (b))
364 #define MIN(a, b) ((a) < (b) ? (a) : (b))
365
366 typedef char boolean;
367 #define false 0
368 #define true 1
369
370 struct re_pattern_buffer;
371
372 static int
373 re_match_2_internal (struct re_pattern_buffer *bufp, const char *string1, int size1,
374 const char *string2, int size2, int pos, struct re_registers *regs, int stop);
375
376
377 /* These are the command codes that appear in compiled regular
378 expressions. Some opcodes are followed by argument bytes. A
379 command code can specify any interpretation whatsoever for its
380 arguments. Zero bytes may appear in the compiled regular expression. */
381
382 typedef enum
383 {
384 no_op = 0,
385
386 /* Succeed right away--no more backtracking. */
387 succeed,
388
389 /* Followed by one byte giving n, then by n literal bytes. */
390 exactn,
391
392 /* Matches any (more or less) character. */
393 anychar,
394
395 /* Matches any one char belonging to specified set. First
396 following byte is number of bitmap bytes. Then come bytes
397 for a bitmap saying which chars are in. Bits in each byte
398 are ordered low-bit-first. A character is in the set if its
399 bit is 1. A character too large to have a bit in the map is
400 automatically not in the set. */
401 charset,
402
403 /* Same parameters as charset, but match any character that is
404 not one of those specified. */
405 charset_not,
406
407 /* Start remembering the text that is matched, for storing in a
408 register. Followed by one byte with the register number, in
409 the range 0 to one less than the pattern buffer's re_nsub
410 field. Then followed by one byte with the number of groups
411 inner to this one. (This last has to be part of the
412 start_memory only because we need it in the on_failure_jump
413 of re_match_2.) */
414 start_memory,
415
416 /* Stop remembering the text that is matched and store it in a
417 memory register. Followed by one byte with the register
418 number, in the range 0 to one less than `re_nsub' in the
419 pattern buffer, and one byte with the number of inner groups,
420 just like `start_memory'. (We need the number of inner
421 groups here because we don't have any easy way of finding the
422 corresponding start_memory when we're at a stop_memory.) */
423 stop_memory,
424
425 /* Match a duplicate of something remembered. Followed by one
426 byte containing the register number. */
427 duplicate,
428
429 /* Fail unless at beginning of line. */
430 begline,
431
432 /* Fail unless at end of line. */
433 endline,
434
435 /* Succeeds if at beginning of buffer (if emacs) or at beginning
436 of string to be matched (if not). */
437 begbuf,
438
439 /* Analogously, for end of buffer/string. */
440 endbuf,
441
442 /* Followed by two byte relative address to which to jump. */
443 jump,
444
445 /* Same as jump, but marks the end of an alternative. */
446 jump_past_alt,
447
448 /* Followed by two-byte relative address of place to resume at
449 in case of failure. */
450 on_failure_jump,
451
452 /* Like on_failure_jump, but pushes a placeholder instead of the
453 current string position when executed. */
454 on_failure_keep_string_jump,
455
456 /* Throw away latest failure point and then jump to following
457 two-byte relative address. */
458 pop_failure_jump,
459
460 /* Change to pop_failure_jump if know won't have to backtrack to
461 match; otherwise change to jump. This is used to jump
462 back to the beginning of a repeat. If what follows this jump
463 clearly won't match what the repeat does, such that we can be
464 sure that there is no use backtracking out of repetitions
465 already matched, then we change it to a pop_failure_jump.
466 Followed by two-byte address. */
467 maybe_pop_jump,
468
469 /* Jump to following two-byte address, and push a dummy failure
470 point. This failure point will be thrown away if an attempt
471 is made to use it for a failure. A `+' construct makes this
472 before the first repeat. Also used as an intermediary kind
473 of jump when compiling an alternative. */
474 dummy_failure_jump,
475
476 /* Push a dummy failure point and continue. Used at the end of
477 alternatives. */
478 push_dummy_failure,
479
480 /* Followed by two-byte relative address and two-byte number n.
481 After matching N times, jump to the address upon failure. */
482 succeed_n,
483
484 /* Followed by two-byte relative address, and two-byte number n.
485 Jump to the address N times, then fail. */
486 jump_n,
487
488 /* Set the following two-byte relative address to the
489 subsequent two-byte number. The address *includes* the two
490 bytes of number. */
491 set_number_at,
492
493 wordchar, /* Matches any word-constituent character. */
494 notwordchar, /* Matches any char that is not a word-constituent. */
495
496 wordbeg, /* Succeeds if at word beginning. */
497 wordend, /* Succeeds if at word end. */
498
499 wordbound, /* Succeeds if at a word boundary. */
500 notwordbound /* Succeeds if not at a word boundary. */
501
502 #ifdef emacs
503 ,before_dot, /* Succeeds if before point. */
504 at_dot, /* Succeeds if at point. */
505 after_dot, /* Succeeds if after point. */
506
507 /* Matches any character whose syntax is specified. Followed by
508 a byte which contains a syntax code, e.g., Sword. */
509 syntaxspec,
510
511 /* Matches any character whose syntax is not that specified. */
512 notsyntaxspec
513 #endif /* emacs */
514 } re_opcode_t;
515
516 /* Common operations on the compiled pattern. */
517
518 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
519
520 #define STORE_NUMBER(destination, number) \
521 do { \
522 (destination)[0] = (number) & 0377; \
523 (destination)[1] = (number) >> 8; \
524 } while (0)
525
526 /* Same as STORE_NUMBER, except increment DESTINATION to
527 the byte after where the number is stored. Therefore, DESTINATION
528 must be an lvalue. */
529
530 #define STORE_NUMBER_AND_INCR(destination, number) \
531 do { \
532 STORE_NUMBER (destination, number); \
533 (destination) += 2; \
534 } while (0)
535
536 /* Put into DESTINATION a number stored in two contiguous bytes starting
537 at SOURCE. */
538
539 #define EXTRACT_NUMBER(destination, source) \
540 do { \
541 (destination) = *(source) & 0377; \
542 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
543 } while (0)
544
545 #ifdef DEBUG
546 static void extract_number _RE_ARGS ((int *dest, unsigned char *source));
547 static void
extract_number(dest,source)548 extract_number (dest, source)
549 int *dest;
550 unsigned char *source;
551 {
552 int temp = SIGN_EXTEND_CHAR (*(source + 1));
553 *dest = *source & 0377;
554 *dest += temp << 8;
555 }
556
557 #ifndef EXTRACT_MACROS /* To debug the macros. */
558 #undef EXTRACT_NUMBER
559 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
560 #endif /* not EXTRACT_MACROS */
561
562 #endif /* DEBUG */
563
564 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
565 SOURCE must be an lvalue. */
566
567 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
568 do { \
569 EXTRACT_NUMBER (destination, source); \
570 (source) += 2; \
571 } while (0)
572
573 #ifdef DEBUG
574 static void extract_number_and_incr _RE_ARGS ((int *destination,
575 unsigned char **source));
576 static void
extract_number_and_incr(destination,source)577 extract_number_and_incr (destination, source)
578 int *destination;
579 unsigned char **source;
580 {
581 extract_number (destination, *source);
582 *source += 2;
583 }
584
585 #ifndef EXTRACT_MACROS
586 #undef EXTRACT_NUMBER_AND_INCR
587 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
588 extract_number_and_incr (&dest, &src)
589 #endif /* not EXTRACT_MACROS */
590
591 #endif /* DEBUG */
592
593 /* If DEBUG is defined, Regex prints many voluminous messages about what
594 it is doing (if the variable `debug' is nonzero). If linked with the
595 main program in `iregex.c', you can enter patterns and strings
596 interactively. And if linked with the main program in `main.c' and
597 the other test files, you can run the already-written tests. */
598
599 #ifdef DEBUG
600
601 /* We use standard I/O for debugging. */
602 #include <stdio.h>
603
604 /* It is useful to test things that ``must'' be true when debugging. */
605 #include <assert.h>
606
607 static int debug = 0;
608
609 #define DEBUG_STATEMENT(e) e
610 #define DEBUG_PRINT1(x) if (debug) printf (x)
611 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
612 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
613 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
614 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
615 if (debug) print_partial_compiled_pattern (s, e)
616 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
617 if (debug) print_double_string (w, s1, sz1, s2, sz2)
618
619
620 /* Print the fastmap in human-readable form. */
621
622 void
print_fastmap(fastmap)623 print_fastmap (fastmap)
624 char *fastmap;
625 {
626 unsigned was_a_range = 0;
627 unsigned i = 0;
628
629 while (i < (1 << BYTEWIDTH))
630 {
631 if (fastmap[i++])
632 {
633 was_a_range = 0;
634 putchar (i - 1);
635 while (i < (1 << BYTEWIDTH) && fastmap[i])
636 {
637 was_a_range = 1;
638 i++;
639 }
640 if (was_a_range)
641 {
642 printf ("-");
643 putchar (i - 1);
644 }
645 }
646 }
647 putchar ('\n');
648 }
649
650
651 /* Print a compiled pattern string in human-readable form, starting at
652 the START pointer into it and ending just before the pointer END. */
653
654 void
print_partial_compiled_pattern(start,end)655 print_partial_compiled_pattern (start, end)
656 unsigned char *start;
657 unsigned char *end;
658 {
659 int mcnt, mcnt2;
660 unsigned char *p1;
661 unsigned char *p = start;
662 unsigned char *pend = end;
663
664 if (start == NULL)
665 {
666 printf ("(null)\n");
667 return;
668 }
669
670 /* Loop over pattern commands. */
671 while (p < pend)
672 {
673 printf ("%d:\t", p - start);
674
675 switch ((re_opcode_t) *p++)
676 {
677 case no_op:
678 printf ("/no_op");
679 break;
680
681 case exactn:
682 mcnt = *p++;
683 printf ("/exactn/%d", mcnt);
684 do
685 {
686 putchar ('/');
687 putchar (*p++);
688 }
689 while (--mcnt);
690 break;
691
692 case start_memory:
693 mcnt = *p++;
694 printf ("/start_memory/%d/%d", mcnt, *p++);
695 break;
696
697 case stop_memory:
698 mcnt = *p++;
699 printf ("/stop_memory/%d/%d", mcnt, *p++);
700 break;
701
702 case duplicate:
703 printf ("/duplicate/%d", *p++);
704 break;
705
706 case anychar:
707 printf ("/anychar");
708 break;
709
710 case charset:
711 case charset_not:
712 {
713 register int c, last = -100;
714 register int in_range = 0;
715
716 printf ("/charset [%s",
717 (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
718
719 assert (p + *p < pend);
720
721 for (c = 0; c < 256; c++)
722 if (c / 8 < *p
723 && (p[1 + (c/8)] & (1 << (c % 8))))
724 {
725 /* Are we starting a range? */
726 if (last + 1 == c && ! in_range)
727 {
728 putchar ('-');
729 in_range = 1;
730 }
731 /* Have we broken a range? */
732 else if (last + 1 != c && in_range)
733 {
734 putchar (last);
735 in_range = 0;
736 }
737
738 if (! in_range)
739 putchar (c);
740
741 last = c;
742 }
743
744 if (in_range)
745 putchar (last);
746
747 putchar (']');
748
749 p += 1 + *p;
750 }
751 break;
752
753 case begline:
754 printf ("/begline");
755 break;
756
757 case endline:
758 printf ("/endline");
759 break;
760
761 case on_failure_jump:
762 extract_number_and_incr (&mcnt, &p);
763 printf ("/on_failure_jump to %d", p + mcnt - start);
764 break;
765
766 case on_failure_keep_string_jump:
767 extract_number_and_incr (&mcnt, &p);
768 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
769 break;
770
771 case dummy_failure_jump:
772 extract_number_and_incr (&mcnt, &p);
773 printf ("/dummy_failure_jump to %d", p + mcnt - start);
774 break;
775
776 case push_dummy_failure:
777 printf ("/push_dummy_failure");
778 break;
779
780 case maybe_pop_jump:
781 extract_number_and_incr (&mcnt, &p);
782 printf ("/maybe_pop_jump to %d", p + mcnt - start);
783 break;
784
785 case pop_failure_jump:
786 extract_number_and_incr (&mcnt, &p);
787 printf ("/pop_failure_jump to %d", p + mcnt - start);
788 break;
789
790 case jump_past_alt:
791 extract_number_and_incr (&mcnt, &p);
792 printf ("/jump_past_alt to %d", p + mcnt - start);
793 break;
794
795 case jump:
796 extract_number_and_incr (&mcnt, &p);
797 printf ("/jump to %d", p + mcnt - start);
798 break;
799
800 case succeed_n:
801 extract_number_and_incr (&mcnt, &p);
802 p1 = p + mcnt;
803 extract_number_and_incr (&mcnt2, &p);
804 printf ("/succeed_n to %d, %d times", p1 - start, mcnt2);
805 break;
806
807 case jump_n:
808 extract_number_and_incr (&mcnt, &p);
809 p1 = p + mcnt;
810 extract_number_and_incr (&mcnt2, &p);
811 printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
812 break;
813
814 case set_number_at:
815 extract_number_and_incr (&mcnt, &p);
816 p1 = p + mcnt;
817 extract_number_and_incr (&mcnt2, &p);
818 printf ("/set_number_at location %d to %d", p1 - start, mcnt2);
819 break;
820
821 case wordbound:
822 printf ("/wordbound");
823 break;
824
825 case notwordbound:
826 printf ("/notwordbound");
827 break;
828
829 case wordbeg:
830 printf ("/wordbeg");
831 break;
832
833 case wordend:
834 printf ("/wordend");
835
836 #ifdef emacs
837 case before_dot:
838 printf ("/before_dot");
839 break;
840
841 case at_dot:
842 printf ("/at_dot");
843 break;
844
845 case after_dot:
846 printf ("/after_dot");
847 break;
848
849 case syntaxspec:
850 printf ("/syntaxspec");
851 mcnt = *p++;
852 printf ("/%d", mcnt);
853 break;
854
855 case notsyntaxspec:
856 printf ("/notsyntaxspec");
857 mcnt = *p++;
858 printf ("/%d", mcnt);
859 break;
860 #endif /* emacs */
861
862 case wordchar:
863 printf ("/wordchar");
864 break;
865
866 case notwordchar:
867 printf ("/notwordchar");
868 break;
869
870 case begbuf:
871 printf ("/begbuf");
872 break;
873
874 case endbuf:
875 printf ("/endbuf");
876 break;
877
878 default:
879 printf ("?%d", *(p-1));
880 }
881
882 putchar ('\n');
883 }
884
885 printf ("%d:\tend of pattern.\n", p - start);
886 }
887
888
889 void
print_compiled_pattern(bufp)890 print_compiled_pattern (bufp)
891 struct re_pattern_buffer *bufp;
892 {
893 unsigned char *buffer = bufp->buffer;
894
895 print_partial_compiled_pattern (buffer, buffer + bufp->used);
896 printf ("%ld bytes used/%ld bytes allocated.\n",
897 bufp->used, bufp->allocated);
898
899 if (bufp->fastmap_accurate && bufp->fastmap)
900 {
901 printf ("fastmap: ");
902 print_fastmap (bufp->fastmap);
903 }
904
905 printf ("re_nsub: %d\t", bufp->re_nsub);
906 printf ("regs_alloc: %d\t", bufp->regs_allocated);
907 printf ("can_be_null: %d\t", bufp->can_be_null);
908 printf ("newline_anchor: %d\n", bufp->newline_anchor);
909 printf ("no_sub: %d\t", bufp->no_sub);
910 printf ("not_bol: %d\t", bufp->not_bol);
911 printf ("not_eol: %d\t", bufp->not_eol);
912 printf ("syntax: %lx\n", bufp->syntax);
913 /* Perhaps we should print the translate table? */
914 }
915
916
917 void
print_double_string(where,string1,size1,string2,size2)918 print_double_string (where, string1, size1, string2, size2)
919 const char *where;
920 const char *string1;
921 const char *string2;
922 int size1;
923 int size2;
924 {
925 int this_char;
926
927 if (where == NULL)
928 printf ("(null)");
929 else
930 {
931 if (FIRST_STRING_P (where))
932 {
933 for (this_char = where - string1; this_char < size1; this_char++)
934 putchar (string1[this_char]);
935
936 where = string2;
937 }
938
939 for (this_char = where - string2; this_char < size2; this_char++)
940 putchar (string2[this_char]);
941 }
942 }
943
944 void
printchar(c)945 printchar (c)
946 int c;
947 {
948 putc (c, stderr);
949 }
950
951 #else /* not DEBUG */
952
953 #undef assert
954 #define assert(e)
955
956 #define DEBUG_STATEMENT(e)
957 #define DEBUG_PRINT1(x)
958 #define DEBUG_PRINT2(x1, x2)
959 #define DEBUG_PRINT3(x1, x2, x3)
960 #define DEBUG_PRINT4(x1, x2, x3, x4)
961 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
962 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
963
964 #endif /* not DEBUG */
965
966 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
967 also be assigned to arbitrarily: each pattern buffer stores its own
968 syntax, so it can be changed between regex compilations. */
969 /* This has no initializer because initialized variables in Emacs
970 become read-only after dumping. */
971 reg_syntax_t re_syntax_options;
972
973
974 /* Specify the precise syntax of regexps for compilation. This provides
975 for compatibility for various utilities which historically have
976 different, incompatible syntaxes.
977
978 The argument SYNTAX is a bit mask comprised of the various bits
979 defined in rx.h. We return the old syntax. */
980
981 reg_syntax_t
re_set_syntax(syntax)982 re_set_syntax (syntax)
983 reg_syntax_t syntax;
984 {
985 reg_syntax_t ret = re_syntax_options;
986
987 re_syntax_options = syntax;
988 #ifdef DEBUG
989 if (syntax & RE_DEBUG)
990 debug = 1;
991 else if (debug) /* was on but now is not */
992 debug = 0;
993 #endif /* DEBUG */
994 return ret;
995 }
996
997 /* This table gives an error message for each of the error codes listed
998 in rx.h. Obviously the order here has to be same as there.
999 POSIX doesn't require that we do anything for REG_NOERROR,
1000 but why not be nice? */
1001
1002 static const char *re_error_msgid[] =
1003 {
1004 gettext_noop ("Success"), /* REG_NOERROR */
1005 gettext_noop ("No match"), /* REG_NOMATCH */
1006 gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
1007 gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
1008 gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
1009 gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
1010 gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
1011 gettext_noop ("Unmatched [ or [^"), /* REG_EBRACK */
1012 gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
1013 gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
1014 gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
1015 gettext_noop ("Invalid range end"), /* REG_ERANGE */
1016 gettext_noop ("Memory exhausted"), /* REG_ESPACE */
1017 gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
1018 gettext_noop ("Premature end of regular expression"), /* REG_EEND */
1019 gettext_noop ("Regular expression too big"), /* REG_ESIZE */
1020 gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
1021 };
1022
1023 /* Avoiding alloca during matching, to placate r_alloc. */
1024
1025 /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
1026 searching and matching functions should not call alloca. On some
1027 systems, alloca is implemented in terms of malloc, and if we're
1028 using the relocating allocator routines, then malloc could cause a
1029 relocation, which might (if the strings being searched are in the
1030 ralloc heap) shift the data out from underneath the regexp
1031 routines.
1032
1033 Here's another reason to avoid allocation: Emacs
1034 processes input from X in a signal handler; processing X input may
1035 call malloc; if input arrives while a matching routine is calling
1036 malloc, then we're scrod. But Emacs can't just block input while
1037 calling matching routines; then we don't notice interrupts when
1038 they come in. So, Emacs blocks input around all regexp calls
1039 except the matching calls, which it leaves unprotected, in the
1040 faith that they will not malloc. */
1041
1042 /* Normally, this is fine. */
1043 #define MATCH_MAY_ALLOCATE
1044
1045 /* When using GNU C, we are not REALLY using the C alloca, no matter
1046 what config.h may say. So don't take precautions for it. */
1047 #ifdef __GNUC__
1048 #undef C_ALLOCA
1049 #endif
1050
1051 /* The match routines may not allocate if (1) they would do it with malloc
1052 and (2) it's not safe for them to use malloc.
1053 Note that if REL_ALLOC is defined, matching would not use malloc for the
1054 failure stack, but we would still use it for the register vectors;
1055 so REL_ALLOC should not affect this. */
1056 #if (defined (C_ALLOCA) || defined (REGEX_MALLOC)) && defined (emacs)
1057 #undef MATCH_MAY_ALLOCATE
1058 #endif
1059
1060
1061 /* Failure stack declarations and macros; both re_compile_fastmap and
1062 re_match_2 use a failure stack. These have to be macros because of
1063 REGEX_ALLOCATE_STACK. */
1064
1065
1066 /* Number of failure points for which to initially allocate space
1067 when matching. If this number is exceeded, we allocate more
1068 space, so it is not a hard limit. */
1069 #ifndef INIT_FAILURE_ALLOC
1070 #define INIT_FAILURE_ALLOC 5
1071 #endif
1072
1073 /* Roughly the maximum number of failure points on the stack. Would be
1074 exactly that if always used MAX_FAILURE_ITEMS items each time we failed.
1075 This is a variable only so users of regex can assign to it; we never
1076 change it ourselves. */
1077
1078 #ifdef INT_IS_16BIT
1079
1080 #if defined (MATCH_MAY_ALLOCATE)
1081 /* 4400 was enough to cause a crash on Alpha OSF/1,
1082 whose default stack limit is 2mb. */
1083 long int re_max_failures = 4000;
1084 #else
1085 long int re_max_failures = 2000;
1086 #endif
1087
1088 union fail_stack_elt
1089 {
1090 unsigned char *pointer;
1091 long int integer;
1092 };
1093
1094 typedef union fail_stack_elt fail_stack_elt_t;
1095
1096 typedef struct
1097 {
1098 fail_stack_elt_t *stack;
1099 unsigned long int size;
1100 unsigned long int avail; /* Offset of next open position. */
1101 } fail_stack_type;
1102
1103 #else /* not INT_IS_16BIT */
1104
1105 #if defined (MATCH_MAY_ALLOCATE)
1106 /* 4400 was enough to cause a crash on Alpha OSF/1,
1107 whose default stack limit is 2mb. */
1108 int re_max_failures = 20000;
1109 #else
1110 int re_max_failures = 2000;
1111 #endif
1112
1113 union fail_stack_elt
1114 {
1115 unsigned char *pointer;
1116 int integer;
1117 };
1118
1119 typedef union fail_stack_elt fail_stack_elt_t;
1120
1121 typedef struct
1122 {
1123 fail_stack_elt_t *stack;
1124 unsigned size;
1125 unsigned avail; /* Offset of next open position. */
1126 } fail_stack_type;
1127
1128 #endif /* INT_IS_16BIT */
1129
1130 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
1131 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
1132 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
1133
1134
1135 /* Define macros to initialize and free the failure stack.
1136 Do `return -2' if the alloc fails. */
1137
1138 #ifdef MATCH_MAY_ALLOCATE
1139 #define INIT_FAIL_STACK() \
1140 do { \
1141 fail_stack.stack = (fail_stack_elt_t *) \
1142 REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
1143 \
1144 if (fail_stack.stack == NULL) \
1145 return -2; \
1146 \
1147 fail_stack.size = INIT_FAILURE_ALLOC; \
1148 fail_stack.avail = 0; \
1149 } while (0)
1150
1151 #define RESET_FAIL_STACK() REGEX_FREE_STACK (fail_stack.stack)
1152 #else
1153 #define INIT_FAIL_STACK() \
1154 do { \
1155 fail_stack.avail = 0; \
1156 } while (0)
1157
1158 #define RESET_FAIL_STACK()
1159 #endif
1160
1161
1162 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
1163
1164 Return 1 if succeeds, and 0 if either ran out of memory
1165 allocating space for it or it was already too large.
1166
1167 REGEX_REALLOCATE_STACK requires `destination' be declared. */
1168
1169 #define DOUBLE_FAIL_STACK(fail_stack) \
1170 ((fail_stack).size > (unsigned) (re_max_failures * MAX_FAILURE_ITEMS) \
1171 ? 0 \
1172 : ((fail_stack).stack = (fail_stack_elt_t *) \
1173 REGEX_REALLOCATE_STACK ((fail_stack).stack, \
1174 (fail_stack).size * sizeof (fail_stack_elt_t), \
1175 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
1176 \
1177 (fail_stack).stack == NULL \
1178 ? 0 \
1179 : ((fail_stack).size <<= 1, \
1180 1)))
1181
1182
1183 /* Push pointer POINTER on FAIL_STACK.
1184 Return 1 if was able to do so and 0 if ran out of memory allocating
1185 space to do so. */
1186 #define PUSH_PATTERN_OP(POINTER, FAIL_STACK) \
1187 ((FAIL_STACK_FULL () \
1188 && !DOUBLE_FAIL_STACK (FAIL_STACK)) \
1189 ? 0 \
1190 : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER, \
1191 1))
1192
1193 /* Push a pointer value onto the failure stack.
1194 Assumes the variable `fail_stack'. Probably should only
1195 be called from within `PUSH_FAILURE_POINT'. */
1196 #define PUSH_FAILURE_POINTER(item) \
1197 fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
1198
1199 /* This pushes an integer-valued item onto the failure stack.
1200 Assumes the variable `fail_stack'. Probably should only
1201 be called from within `PUSH_FAILURE_POINT'. */
1202 #define PUSH_FAILURE_INT(item) \
1203 fail_stack.stack[fail_stack.avail++].integer = (item)
1204
1205 /* Push a fail_stack_elt_t value onto the failure stack.
1206 Assumes the variable `fail_stack'. Probably should only
1207 be called from within `PUSH_FAILURE_POINT'. */
1208 #define PUSH_FAILURE_ELT(item) \
1209 fail_stack.stack[fail_stack.avail++] = (item)
1210
1211 /* These three POP... operations complement the three PUSH... operations.
1212 All assume that `fail_stack' is nonempty. */
1213 #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
1214 #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
1215 #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
1216
1217 /* Used to omit pushing failure point id's when we're not debugging. */
1218 #ifdef DEBUG
1219 #define DEBUG_PUSH PUSH_FAILURE_INT
1220 #define DEBUG_POP(item_addr) (item_addr)->integer = POP_FAILURE_INT ()
1221 #else
1222 #define DEBUG_PUSH(item)
1223 #define DEBUG_POP(item_addr)
1224 #endif
1225
1226
1227 /* Push the information about the state we will need
1228 if we ever fail back to it.
1229
1230 Requires variables fail_stack, regstart, regend, reg_info, and
1231 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
1232 declared.
1233
1234 Does `return FAILURE_CODE' if runs out of memory. */
1235
1236 /* following is a mini hack by geo */
1237 #ifdef REGEX_MALLOC
1238 #define DECL_DESTINATION_PLEASE /**/
1239 #else
1240 #define DECL_DESTINATION_PLEASE char *destination;
1241 #endif
1242
1243 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1244 do { \
1245 DECL_DESTINATION_PLEASE \
1246 /* Must be int, so when we don't save any registers, the arithmetic \
1247 of 0 + -1 isn't done as unsigned. */ \
1248 /* Can't be int, since there is not a shred of a guarantee that int \
1249 is wide enough to hold a value of something to which pointer can \
1250 be assigned */ \
1251 s_reg_t this_reg; \
1252 \
1253 DEBUG_STATEMENT (failure_id++); \
1254 DEBUG_STATEMENT (nfailure_points_pushed++); \
1255 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1256 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1257 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1258 \
1259 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
1260 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1261 \
1262 /* Ensure we have enough space allocated for what we will push. */ \
1263 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1264 { \
1265 if (!DOUBLE_FAIL_STACK (fail_stack)) \
1266 return failure_code; \
1267 \
1268 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1269 (fail_stack).size); \
1270 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1271 } \
1272 \
1273 /* Push the info, starting with the registers. */ \
1274 DEBUG_PRINT1 ("\n"); \
1275 \
1276 if (1) \
1277 for (this_reg = lowest_active_reg; this_reg <= (s_reg_t) highest_active_reg; \
1278 this_reg++) \
1279 { \
1280 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
1281 DEBUG_STATEMENT (num_regs_pushed++); \
1282 \
1283 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1284 PUSH_FAILURE_POINTER (regstart[this_reg]); \
1285 \
1286 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1287 PUSH_FAILURE_POINTER (regend[this_reg]); \
1288 \
1289 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
1290 DEBUG_PRINT2 (" match_null=%d", \
1291 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1292 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1293 DEBUG_PRINT2 (" matched_something=%d", \
1294 MATCHED_SOMETHING (reg_info[this_reg])); \
1295 DEBUG_PRINT2 (" ever_matched=%d", \
1296 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1297 DEBUG_PRINT1 ("\n"); \
1298 PUSH_FAILURE_ELT (reg_info[this_reg].word); \
1299 } \
1300 \
1301 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
1302 PUSH_FAILURE_INT (lowest_active_reg); \
1303 \
1304 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
1305 PUSH_FAILURE_INT (highest_active_reg); \
1306 \
1307 DEBUG_PRINT2 (" Pushing pattern 0x%x:\n", pattern_place); \
1308 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1309 PUSH_FAILURE_POINTER (pattern_place); \
1310 \
1311 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
1312 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1313 size2); \
1314 DEBUG_PRINT1 ("'\n"); \
1315 PUSH_FAILURE_POINTER (string_place); \
1316 \
1317 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1318 DEBUG_PUSH (failure_id); \
1319 } while (0)
1320
1321 /* This is the number of items that are pushed and popped on the stack
1322 for each register. */
1323 #define NUM_REG_ITEMS 3
1324
1325 /* Individual items aside from the registers. */
1326 #ifdef DEBUG
1327 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1328 #else
1329 #define NUM_NONREG_ITEMS 4
1330 #endif
1331
1332 /* We push at most this many items on the stack. */
1333 /* We used to use (num_regs - 1), which is the number of registers
1334 this regexp will save; but that was changed to 5
1335 to avoid stack overflow for a regexp with lots of parens. */
1336 #define MAX_FAILURE_ITEMS (5 * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1337
1338 /* We actually push this many items. */
1339 #define NUM_FAILURE_ITEMS \
1340 (((0 \
1341 ? 0 : highest_active_reg - lowest_active_reg + 1) \
1342 * NUM_REG_ITEMS) \
1343 + NUM_NONREG_ITEMS)
1344
1345 /* How many items can still be added to the stack without overflowing it. */
1346 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1347
1348
1349 /* Pops what PUSH_FAIL_STACK pushes.
1350
1351 We restore into the parameters, all of which should be lvalues:
1352 STR -- the saved data position.
1353 PAT -- the saved pattern position.
1354 LOW_REG, HIGH_REG -- the highest and lowest active registers.
1355 REGSTART, REGEND -- arrays of string positions.
1356 REG_INFO -- array of information about each subexpression.
1357
1358 Also assumes the variables `fail_stack' and (if debugging), `bufp',
1359 `pend', `string1', `size1', `string2', and `size2'. */
1360
1361 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1362 { \
1363 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
1364 s_reg_t this_reg; \
1365 const unsigned char *string_temp; \
1366 \
1367 assert (!FAIL_STACK_EMPTY ()); \
1368 \
1369 /* Remove failure points and point to how many regs pushed. */ \
1370 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1371 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1372 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1373 \
1374 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1375 \
1376 DEBUG_POP (&failure_id); \
1377 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1378 \
1379 /* If the saved string location is NULL, it came from an \
1380 on_failure_keep_string_jump opcode, and we want to throw away the \
1381 saved NULL, thus retaining our current position in the string. */ \
1382 string_temp = POP_FAILURE_POINTER (); \
1383 if (string_temp != NULL) \
1384 str = (const char *) string_temp; \
1385 \
1386 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
1387 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1388 DEBUG_PRINT1 ("'\n"); \
1389 \
1390 pat = (unsigned char *) POP_FAILURE_POINTER (); \
1391 DEBUG_PRINT2 (" Popping pattern 0x%x:\n", pat); \
1392 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1393 \
1394 /* Restore register info. */ \
1395 high_reg = (active_reg_t) POP_FAILURE_INT (); \
1396 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
1397 \
1398 low_reg = (active_reg_t) POP_FAILURE_INT (); \
1399 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
1400 \
1401 if (1) \
1402 for (this_reg = high_reg; this_reg >= (s_reg_t)low_reg; this_reg--) \
1403 { \
1404 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
1405 \
1406 reg_info[this_reg].word = POP_FAILURE_ELT (); \
1407 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
1408 \
1409 regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1410 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1411 \
1412 regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1413 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1414 } \
1415 else \
1416 { \
1417 for (this_reg = highest_active_reg; this_reg > (s_reg_t)high_reg; this_reg--) \
1418 { \
1419 reg_info[this_reg].word.integer = 0; \
1420 regend[this_reg] = 0; \
1421 regstart[this_reg] = 0; \
1422 } \
1423 highest_active_reg = high_reg; \
1424 } \
1425 \
1426 set_regs_matched_done = 0; \
1427 DEBUG_STATEMENT (nfailure_points_popped++); \
1428 } /* POP_FAILURE_POINT */
1429
1430
1431
1432 /* Structure for per-register (a.k.a. per-group) information.
1433 Other register information, such as the
1434 starting and ending positions (which are addresses), and the list of
1435 inner groups (which is a bits list) are maintained in separate
1436 variables.
1437
1438 We are making a (strictly speaking) nonportable assumption here: that
1439 the compiler will pack our bit fields into something that fits into
1440 the type of `word', i.e., is something that fits into one item on the
1441 failure stack. */
1442
1443
1444 /* Declarations and macros for re_match_2. */
1445
1446 typedef union
1447 {
1448 fail_stack_elt_t word;
1449 struct
1450 {
1451 /* This field is one if this group can match the empty string,
1452 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1453 #define MATCH_NULL_UNSET_VALUE 3
1454 unsigned match_null_string_p : 2;
1455 unsigned is_active : 1;
1456 unsigned matched_something : 1;
1457 unsigned ever_matched_something : 1;
1458 } bits;
1459 } register_info_type;
1460
1461 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1462 #define IS_ACTIVE(R) ((R).bits.is_active)
1463 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1464 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1465
1466
1467 /* Call this when have matched a real character; it sets `matched' flags
1468 for the subexpressions which we are currently inside. Also records
1469 that those subexprs have matched. */
1470 #define SET_REGS_MATCHED() \
1471 do \
1472 { \
1473 if (!set_regs_matched_done) \
1474 { \
1475 active_reg_t r; \
1476 set_regs_matched_done = 1; \
1477 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1478 { \
1479 MATCHED_SOMETHING (reg_info[r]) \
1480 = EVER_MATCHED_SOMETHING (reg_info[r]) \
1481 = 1; \
1482 } \
1483 } \
1484 } \
1485 while (0)
1486
1487 /* Registers are set to a sentinel when they haven't yet matched. */
1488 static char reg_unset_dummy;
1489 #define REG_UNSET_VALUE (®_unset_dummy)
1490 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1491
1492 /* Subroutine declarations and macros for regex_compile. */
1493
1494 static reg_errcode_t regex_compile _RE_ARGS ((const char *pattern, size_t size,
1495 reg_syntax_t syntax,
1496 struct re_pattern_buffer *bufp));
1497 static void store_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg));
1498 static void store_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1499 int arg1, int arg2));
1500 static void insert_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1501 int arg, unsigned char *end));
1502 static void insert_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1503 int arg1, int arg2, unsigned char *end));
1504 static boolean at_begline_loc_p _RE_ARGS ((const char *pattern, const char *p,
1505 reg_syntax_t syntax));
1506 static boolean at_endline_loc_p _RE_ARGS ((const char *p, const char *pend,
1507 reg_syntax_t syntax));
1508 static reg_errcode_t compile_range _RE_ARGS ((const char **p_ptr,
1509 const char *pend,
1510 char *translate,
1511 reg_syntax_t syntax,
1512 unsigned char *b));
1513
1514 /* Fetch the next character in the uncompiled pattern---translating it
1515 if necessary. Also cast from a signed character in the constant
1516 string passed to us by the user to an unsigned char that we can use
1517 as an array index (in, e.g., `translate'). */
1518 #ifndef PATFETCH
1519 #define PATFETCH(c) \
1520 do {if (p == pend) return REG_EEND; \
1521 c = (unsigned char) *p++; \
1522 if (translate) c = (unsigned char) translate[c]; \
1523 } while (0)
1524 #endif
1525
1526 /* Fetch the next character in the uncompiled pattern, with no
1527 translation. */
1528 #define PATFETCH_RAW(c) \
1529 do {if (p == pend) return REG_EEND; \
1530 c = (unsigned char) *p++; \
1531 } while (0)
1532
1533 /* Go backwards one character in the pattern. */
1534 #define PATUNFETCH p--
1535
1536
1537 /* If `translate' is non-null, return translate[D], else just D. We
1538 cast the subscript to translate because some data is declared as
1539 `char *', to avoid warnings when a string constant is passed. But
1540 when we use a character as a subscript we must make it unsigned. */
1541 #ifndef TRANSLATE
1542 #define TRANSLATE(d) \
1543 (translate ? (char) translate[(unsigned char) (d)] : (d))
1544 #endif
1545
1546
1547 /* Macros for outputting the compiled pattern into `buffer'. */
1548
1549 /* If the buffer isn't allocated when it comes in, use this. */
1550 #define INIT_BUF_SIZE 32
1551
1552 /* Make sure we have at least N more bytes of space in buffer. */
1553 #define GET_BUFFER_SPACE(n) \
1554 while ((unsigned long) (b - bufp->buffer + (n)) > bufp->allocated) \
1555 EXTEND_BUFFER ()
1556
1557 /* Make sure we have one more byte of buffer space and then add C to it. */
1558 #define BUF_PUSH(c) \
1559 do { \
1560 GET_BUFFER_SPACE (1); \
1561 *b++ = (unsigned char) (c); \
1562 } while (0)
1563
1564
1565 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1566 #define BUF_PUSH_2(c1, c2) \
1567 do { \
1568 GET_BUFFER_SPACE (2); \
1569 *b++ = (unsigned char) (c1); \
1570 *b++ = (unsigned char) (c2); \
1571 } while (0)
1572
1573
1574 /* As with BUF_PUSH_2, except for three bytes. */
1575 #define BUF_PUSH_3(c1, c2, c3) \
1576 do { \
1577 GET_BUFFER_SPACE (3); \
1578 *b++ = (unsigned char) (c1); \
1579 *b++ = (unsigned char) (c2); \
1580 *b++ = (unsigned char) (c3); \
1581 } while (0)
1582
1583
1584 /* Store a jump with opcode OP at LOC to location TO. We store a
1585 relative address offset by the three bytes the jump itself occupies. */
1586 #define STORE_JUMP(op, loc, to) \
1587 store_op1 (op, loc, (int) ((to) - (loc) - 3))
1588
1589 /* Likewise, for a two-argument jump. */
1590 #define STORE_JUMP2(op, loc, to, arg) \
1591 store_op2 (op, loc, (int) ((to) - (loc) - 3), arg)
1592
1593 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1594 #define INSERT_JUMP(op, loc, to) \
1595 insert_op1 (op, loc, (int) ((to) - (loc) - 3), b)
1596
1597 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1598 #define INSERT_JUMP2(op, loc, to, arg) \
1599 insert_op2 (op, loc, (int) ((to) - (loc) - 3), arg, b)
1600
1601
1602 /* This is not an arbitrary limit: the arguments which represent offsets
1603 into the pattern are two bytes long. So if 2^16 bytes turns out to
1604 be too small, many things would have to change. */
1605 /* Any other compiler which, like MSC, has allocation limit below 2^16
1606 bytes will have to use approach similar to what was done below for
1607 MSC and drop MAX_BUF_SIZE a bit. Otherwise you may end up
1608 reallocating to 0 bytes. Such thing is not going to work too well.
1609 You have been warned!! */
1610 #if defined(_MSC_VER) && !defined(WIN32)
1611 /* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
1612 The REALLOC define eliminates a flurry of conversion warnings,
1613 but is not required. */
1614 #define MAX_BUF_SIZE 65500L
1615 #define REALLOC(p,s) realloc ((p), (size_t) (s))
1616 #else
1617 #define MAX_BUF_SIZE (1L << 16)
1618 #define REALLOC(p,s) realloc ((p), (s))
1619 #endif
1620
1621 /* Extend the buffer by twice its current size via realloc and
1622 reset the pointers that pointed into the old block to point to the
1623 correct places in the new one. If extending the buffer results in it
1624 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1625 #define EXTEND_BUFFER() \
1626 do { \
1627 unsigned char *old_buffer = bufp->buffer; \
1628 if (bufp->allocated == MAX_BUF_SIZE) \
1629 return REG_ESIZE; \
1630 bufp->allocated <<= 1; \
1631 if (bufp->allocated > MAX_BUF_SIZE) \
1632 bufp->allocated = MAX_BUF_SIZE; \
1633 bufp->buffer = (unsigned char *) REALLOC (bufp->buffer, bufp->allocated);\
1634 if (bufp->buffer == NULL) \
1635 return REG_ESPACE; \
1636 /* If the buffer moved, move all the pointers into it. */ \
1637 if (old_buffer != bufp->buffer) \
1638 { \
1639 b = (b - old_buffer) + bufp->buffer; \
1640 begalt = (begalt - old_buffer) + bufp->buffer; \
1641 if (fixup_alt_jump) \
1642 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1643 if (laststart) \
1644 laststart = (laststart - old_buffer) + bufp->buffer; \
1645 if (pending_exact) \
1646 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1647 } \
1648 } while (0)
1649
1650
1651 /* Since we have one byte reserved for the register number argument to
1652 {start,stop}_memory, the maximum number of groups we can report
1653 things about is what fits in that byte. */
1654 #define MAX_REGNUM 255
1655
1656 /* But patterns can have more than `MAX_REGNUM' registers. We just
1657 ignore the excess. */
1658 typedef unsigned regnum_t;
1659
1660
1661 /* Macros for the compile stack. */
1662
1663 /* Since offsets can go either forwards or backwards, this type needs to
1664 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1665 /* int may be not enough when sizeof(int) == 2. */
1666 typedef long pattern_offset_t;
1667
1668 typedef struct
1669 {
1670 pattern_offset_t begalt_offset;
1671 pattern_offset_t fixup_alt_jump;
1672 pattern_offset_t inner_group_offset;
1673 pattern_offset_t laststart_offset;
1674 regnum_t regnum;
1675 } compile_stack_elt_t;
1676
1677
1678 typedef struct
1679 {
1680 compile_stack_elt_t *stack;
1681 unsigned size;
1682 unsigned avail; /* Offset of next open position. */
1683 } compile_stack_type;
1684
1685
1686 #define INIT_COMPILE_STACK_SIZE 32
1687
1688 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1689 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1690
1691 /* The next available element. */
1692 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1693
1694
1695 /* Set the bit for character C in a list. */
1696 #define SET_LIST_BIT(c) \
1697 (b[((unsigned char) (c)) / BYTEWIDTH] \
1698 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1699
1700
1701 /* Get the next unsigned number in the uncompiled pattern. */
1702 #define GET_UNSIGNED_NUMBER(num) \
1703 { if (p != pend) \
1704 { \
1705 PATFETCH (c); \
1706 while (ISDIGIT (c)) \
1707 { \
1708 if (num < 0) \
1709 num = 0; \
1710 num = num * 10 + c - '0'; \
1711 if (p == pend) \
1712 break; \
1713 PATFETCH (c); \
1714 } \
1715 } \
1716 }
1717
1718 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
1719 /* The GNU C library provides support for user-defined character classes
1720 and the functions from ISO C amendement 1. */
1721 # ifdef CHARCLASS_NAME_MAX
1722 # define CHAR_CLASS_MAX_LENGTH CHARCLASS_NAME_MAX
1723 # else
1724 /* This shouldn't happen but some implementation might still have this
1725 problem. Use a reasonable default value. */
1726 # define CHAR_CLASS_MAX_LENGTH 256
1727 # endif
1728
1729 # define IS_CHAR_CLASS(string) wctype (string)
1730 #else
1731 # define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1732
1733 # define IS_CHAR_CLASS(string) \
1734 (STREQ (string, "alpha") || STREQ (string, "upper") \
1735 || STREQ (string, "lower") || STREQ (string, "digit") \
1736 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1737 || STREQ (string, "space") || STREQ (string, "print") \
1738 || STREQ (string, "punct") || STREQ (string, "graph") \
1739 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1740 #endif
1741
1742 #ifndef MATCH_MAY_ALLOCATE
1743
1744 /* If we cannot allocate large objects within re_match_2_internal,
1745 we make the fail stack and register vectors global.
1746 The fail stack, we grow to the maximum size when a regexp
1747 is compiled.
1748 The register vectors, we adjust in size each time we
1749 compile a regexp, according to the number of registers it needs. */
1750
1751 static fail_stack_type fail_stack;
1752
1753 /* Size with which the following vectors are currently allocated.
1754 That is so we can make them bigger as needed,
1755 but never make them smaller. */
1756 static int regs_allocated_size;
1757
1758 static const char ** regstart, ** regend;
1759 static const char ** old_regstart, ** old_regend;
1760 static const char **best_regstart, **best_regend;
1761 static register_info_type *reg_info;
1762 static const char **reg_dummy;
1763 static register_info_type *reg_info_dummy;
1764
1765 /* Make the register vectors big enough for NUM_REGS registers,
1766 but don't make them smaller. */
1767
1768 static
regex_grow_registers(num_regs)1769 regex_grow_registers (num_regs)
1770 int num_regs;
1771 {
1772 if (num_regs > regs_allocated_size)
1773 {
1774 RETALLOC_IF (regstart, num_regs, const char *);
1775 RETALLOC_IF (regend, num_regs, const char *);
1776 RETALLOC_IF (old_regstart, num_regs, const char *);
1777 RETALLOC_IF (old_regend, num_regs, const char *);
1778 RETALLOC_IF (best_regstart, num_regs, const char *);
1779 RETALLOC_IF (best_regend, num_regs, const char *);
1780 RETALLOC_IF (reg_info, num_regs, register_info_type);
1781 RETALLOC_IF (reg_dummy, num_regs, const char *);
1782 RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
1783
1784 regs_allocated_size = num_regs;
1785 }
1786 }
1787
1788 #endif /* not MATCH_MAY_ALLOCATE */
1789
1790 static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
1791 compile_stack,
1792 regnum_t regnum));
1793
1794 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1795 Returns one of error codes defined in `rx.h', or zero for success.
1796
1797 Assumes the `allocated' (and perhaps `buffer') and `translate'
1798 fields are set in BUFP on entry.
1799
1800 If it succeeds, results are put in BUFP (if it returns an error, the
1801 contents of BUFP are undefined):
1802 `buffer' is the compiled pattern;
1803 `syntax' is set to SYNTAX;
1804 `used' is set to the length of the compiled pattern;
1805 `fastmap_accurate' is zero;
1806 `re_nsub' is the number of subexpressions in PATTERN;
1807 `not_bol' and `not_eol' are zero;
1808
1809 The `fastmap' and `newline_anchor' fields are neither
1810 examined nor set. */
1811
1812 /* Return, freeing storage we allocated. */
1813 #define FREE_STACK_RETURN(value) \
1814 return (free (compile_stack.stack), value)
1815
1816 static reg_errcode_t
regex_compile(pattern,size,syntax,bufp)1817 regex_compile (pattern, size, syntax, bufp)
1818 const char *pattern;
1819 size_t size;
1820 reg_syntax_t syntax;
1821 struct re_pattern_buffer *bufp;
1822 {
1823 /* We fetch characters from PATTERN here. Even though PATTERN is
1824 `char *' (i.e., signed), we declare these variables as unsigned, so
1825 they can be reliably used as array indices. */
1826 register unsigned char c, c1;
1827
1828 /* A random temporary spot in PATTERN. */
1829 const char *p1;
1830
1831 /* Points to the end of the buffer, where we should append. */
1832 register unsigned char *b;
1833
1834 /* Keeps track of unclosed groups. */
1835 compile_stack_type compile_stack;
1836
1837 /* Points to the current (ending) position in the pattern. */
1838 const char *p = pattern;
1839 const char *pend = pattern + size;
1840
1841 /* How to translate the characters in the pattern. */
1842 RE_TRANSLATE_TYPE translate = bufp->translate;
1843
1844 /* Address of the count-byte of the most recently inserted `exactn'
1845 command. This makes it possible to tell if a new exact-match
1846 character can be added to that command or if the character requires
1847 a new `exactn' command. */
1848 unsigned char *pending_exact = 0;
1849
1850 /* Address of start of the most recently finished expression.
1851 This tells, e.g., postfix * where to find the start of its
1852 operand. Reset at the beginning of groups and alternatives. */
1853 unsigned char *laststart = 0;
1854
1855 /* Address of beginning of regexp, or inside of last group. */
1856 unsigned char *begalt;
1857
1858 /* Place in the uncompiled pattern (i.e., the {) to
1859 which to go back if the interval is invalid. */
1860 const char *beg_interval;
1861
1862 /* Address of the place where a forward jump should go to the end of
1863 the containing expression. Each alternative of an `or' -- except the
1864 last -- ends with a forward jump of this sort. */
1865 unsigned char *fixup_alt_jump = 0;
1866
1867 /* Counts open-groups as they are encountered. Remembered for the
1868 matching close-group on the compile stack, so the same register
1869 number is put in the stop_memory as the start_memory. */
1870 regnum_t regnum = 0;
1871
1872 #ifdef DEBUG
1873 DEBUG_PRINT1 ("\nCompiling pattern: ");
1874 if (debug)
1875 {
1876 unsigned debug_count;
1877
1878 for (debug_count = 0; debug_count < size; debug_count++)
1879 putchar (pattern[debug_count]);
1880 putchar ('\n');
1881 }
1882 #endif /* DEBUG */
1883
1884 /* Initialize the compile stack. */
1885 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1886 if (compile_stack.stack == NULL)
1887 return REG_ESPACE;
1888
1889 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1890 compile_stack.avail = 0;
1891
1892 /* Initialize the pattern buffer. */
1893 bufp->syntax = syntax;
1894 bufp->fastmap_accurate = 0;
1895 bufp->not_bol = bufp->not_eol = 0;
1896
1897 /* Set `used' to zero, so that if we return an error, the pattern
1898 printer (for debugging) will think there's no pattern. We reset it
1899 at the end. */
1900 bufp->used = 0;
1901
1902 /* Always count groups, whether or not bufp->no_sub is set. */
1903 bufp->re_nsub = 0;
1904
1905 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1906 /* Initialize the syntax table. */
1907 init_syntax_once ();
1908 #endif
1909
1910 if (bufp->allocated == 0)
1911 {
1912 if (bufp->buffer)
1913 { /* If zero allocated, but buffer is non-null, try to realloc
1914 enough space. This loses if buffer's address is bogus, but
1915 that is the user's responsibility. */
1916 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1917 }
1918 else
1919 { /* Caller did not allocate a buffer. Do it for them. */
1920 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1921 }
1922 if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
1923
1924 bufp->allocated = INIT_BUF_SIZE;
1925 }
1926
1927 begalt = b = bufp->buffer;
1928
1929 /* Loop through the uncompiled pattern until we're at the end. */
1930 while (p != pend)
1931 {
1932 PATFETCH (c);
1933
1934 switch (c)
1935 {
1936 case '^':
1937 {
1938 if ( /* If at start of pattern, it's an operator. */
1939 p == pattern + 1
1940 /* If context independent, it's an operator. */
1941 || syntax & RE_CONTEXT_INDEP_ANCHORS
1942 /* Otherwise, depends on what's come before. */
1943 || at_begline_loc_p (pattern, p, syntax))
1944 BUF_PUSH (begline);
1945 else
1946 goto normal_char;
1947 }
1948 break;
1949
1950
1951 case '$':
1952 {
1953 if ( /* If at end of pattern, it's an operator. */
1954 p == pend
1955 /* If context independent, it's an operator. */
1956 || syntax & RE_CONTEXT_INDEP_ANCHORS
1957 /* Otherwise, depends on what's next. */
1958 || at_endline_loc_p (p, pend, syntax))
1959 BUF_PUSH (endline);
1960 else
1961 goto normal_char;
1962 }
1963 break;
1964
1965
1966 case '+':
1967 case '?':
1968 if ((syntax & RE_BK_PLUS_QM)
1969 || (syntax & RE_LIMITED_OPS))
1970 goto normal_char;
1971 handle_plus:
1972 case '*':
1973 /* If there is no previous pattern... */
1974 if (!laststart)
1975 {
1976 if (syntax & RE_CONTEXT_INVALID_OPS)
1977 FREE_STACK_RETURN (REG_BADRPT);
1978 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1979 goto normal_char;
1980 }
1981
1982 {
1983 /* Are we optimizing this jump? */
1984 boolean keep_string_p = false;
1985
1986 /* 1 means zero (many) matches is allowed. */
1987 char zero_times_ok = 0, many_times_ok = 0;
1988
1989 /* If there is a sequence of repetition chars, collapse it
1990 down to just one (the right one). We can't combine
1991 interval operators with these because of, e.g., `a{2}*',
1992 which should only match an even number of `a's. */
1993
1994 for (;;)
1995 {
1996 zero_times_ok |= c != '+';
1997 many_times_ok |= c != '?';
1998
1999 if (p == pend)
2000 break;
2001
2002 PATFETCH (c);
2003
2004 if (c == '*'
2005 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
2006 ;
2007
2008 else if (syntax & RE_BK_PLUS_QM && c == '\\')
2009 {
2010 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2011
2012 PATFETCH (c1);
2013 if (!(c1 == '+' || c1 == '?'))
2014 {
2015 PATUNFETCH;
2016 PATUNFETCH;
2017 break;
2018 }
2019
2020 c = c1;
2021 }
2022 else
2023 {
2024 PATUNFETCH;
2025 break;
2026 }
2027
2028 /* If we get here, we found another repeat character. */
2029 }
2030
2031 /* Star, etc. applied to an empty pattern is equivalent
2032 to an empty pattern. */
2033 if (!laststart)
2034 break;
2035
2036 /* Now we know whether or not zero matches is allowed
2037 and also whether or not two or more matches is allowed. */
2038 if (many_times_ok)
2039 { /* More than one repetition is allowed, so put in at the
2040 end a backward relative jump from `b' to before the next
2041 jump we're going to put in below (which jumps from
2042 laststart to after this jump).
2043
2044 But if we are at the `*' in the exact sequence `.*\n',
2045 insert an unconditional jump backwards to the .,
2046 instead of the beginning of the loop. This way we only
2047 push a failure point once, instead of every time
2048 through the loop. */
2049 assert (p - 1 > pattern);
2050
2051 /* Allocate the space for the jump. */
2052 GET_BUFFER_SPACE (3);
2053
2054 /* We know we are not at the first character of the pattern,
2055 because laststart was nonzero. And we've already
2056 incremented `p', by the way, to be the character after
2057 the `*'. Do we have to do something analogous here
2058 for null bytes, because of RE_DOT_NOT_NULL? */
2059 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
2060 && zero_times_ok
2061 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
2062 && !(syntax & RE_DOT_NEWLINE))
2063 { /* We have .*\n. */
2064 STORE_JUMP (jump, b, laststart);
2065 keep_string_p = true;
2066 }
2067 else
2068 /* Anything else. */
2069 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
2070
2071 /* We've added more stuff to the buffer. */
2072 b += 3;
2073 }
2074
2075 /* On failure, jump from laststart to b + 3, which will be the
2076 end of the buffer after this jump is inserted. */
2077 GET_BUFFER_SPACE (3);
2078 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
2079 : on_failure_jump,
2080 laststart, b + 3);
2081 pending_exact = 0;
2082 b += 3;
2083
2084 if (!zero_times_ok)
2085 {
2086 /* At least one repetition is required, so insert a
2087 `dummy_failure_jump' before the initial
2088 `on_failure_jump' instruction of the loop. This
2089 effects a skip over that instruction the first time
2090 we hit that loop. */
2091 GET_BUFFER_SPACE (3);
2092 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
2093 b += 3;
2094 }
2095 }
2096 break;
2097
2098
2099 case '.':
2100 laststart = b;
2101 BUF_PUSH (anychar);
2102 break;
2103
2104
2105 case '[':
2106 {
2107 boolean had_char_class = false;
2108
2109 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2110
2111 /* Ensure that we have enough space to push a charset: the
2112 opcode, the length count, and the bitset; 34 bytes in all. */
2113 GET_BUFFER_SPACE (34);
2114
2115 laststart = b;
2116
2117 /* We test `*p == '^' twice, instead of using an if
2118 statement, so we only need one BUF_PUSH. */
2119 BUF_PUSH (*p == '^' ? charset_not : charset);
2120 if (*p == '^')
2121 p++;
2122
2123 /* Remember the first position in the bracket expression. */
2124 p1 = p;
2125
2126 /* Push the number of bytes in the bitmap. */
2127 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
2128
2129 /* Clear the whole map. */
2130 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
2131
2132 /* charset_not matches newline according to a syntax bit. */
2133 if ((re_opcode_t) b[-2] == charset_not
2134 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
2135 SET_LIST_BIT ('\n');
2136
2137 /* Read in characters and ranges, setting map bits. */
2138 for (;;)
2139 {
2140 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2141
2142 PATFETCH (c);
2143
2144 /* \ might escape characters inside [...] and [^...]. */
2145 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
2146 {
2147 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2148
2149 PATFETCH (c1);
2150 SET_LIST_BIT (c1);
2151 continue;
2152 }
2153
2154 /* Could be the end of the bracket expression. If it's
2155 not (i.e., when the bracket expression is `[]' so
2156 far), the ']' character bit gets set way below. */
2157 if (c == ']' && p != p1 + 1)
2158 break;
2159
2160 /* Look ahead to see if it's a range when the last thing
2161 was a character class. */
2162 if (had_char_class && c == '-' && *p != ']')
2163 FREE_STACK_RETURN (REG_ERANGE);
2164
2165 /* Look ahead to see if it's a range when the last thing
2166 was a character: if this is a hyphen not at the
2167 beginning or the end of a list, then it's the range
2168 operator. */
2169 if (c == '-'
2170 && !(p - 2 >= pattern && p[-2] == '[')
2171 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
2172 && *p != ']')
2173 {
2174 reg_errcode_t ret
2175 = compile_range (&p, pend, translate, syntax, b);
2176 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2177 }
2178
2179 else if (p[0] == '-' && p[1] != ']')
2180 { /* This handles ranges made up of characters only. */
2181 reg_errcode_t ret;
2182
2183 /* Move past the `-'. */
2184 PATFETCH (c1);
2185
2186 ret = compile_range (&p, pend, translate, syntax, b);
2187 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2188 }
2189
2190 /* See if we're at the beginning of a possible character
2191 class. */
2192
2193 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
2194 { /* Leave room for the null. */
2195 char str[CHAR_CLASS_MAX_LENGTH + 1];
2196
2197 PATFETCH (c);
2198 c1 = 0;
2199
2200 /* If pattern is `[[:'. */
2201 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2202
2203 for (;;)
2204 {
2205 PATFETCH (c);
2206 if (c == ':' || c == ']' || p == pend
2207 || c1 == CHAR_CLASS_MAX_LENGTH)
2208 break;
2209 str[c1++] = c;
2210 }
2211 str[c1] = '\0';
2212
2213 /* If isn't a word bracketed by `[:' and:`]':
2214 undo the ending character, the letters, and leave
2215 the leading `:' and `[' (but set bits for them). */
2216 if (c == ':' && *p == ']')
2217 {
2218 #ifdef BROKEN_LOCALE
2219 FREE_STACK_RETURN(REG_ECTYPE);
2220 #else
2221 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
2222 boolean is_lower = STREQ (str, "lower");
2223 boolean is_upper = STREQ (str, "upper");
2224 wctype_t wt;
2225 int ch;
2226
2227 wt = wctype (str);
2228 if (wt == 0)
2229 FREE_STACK_RETURN (REG_ECTYPE);
2230
2231 /* Throw away the ] at the end of the character
2232 class. */
2233 PATFETCH (c);
2234
2235 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2236
2237 for (ch = 0; ch < 1 << BYTEWIDTH; ++ch)
2238 {
2239 if (iswctype (btowc (ch), wt))
2240 SET_LIST_BIT (ch);
2241
2242 if (translate && (is_upper || is_lower)
2243 && (ISUPPER (ch) || ISLOWER (ch)))
2244 SET_LIST_BIT (ch);
2245 }
2246
2247 had_char_class = true;
2248 #else
2249 int ch;
2250 boolean is_alnum = STREQ (str, "alnum");
2251 boolean is_alpha = STREQ (str, "alpha");
2252 boolean is_blank = STREQ (str, "blank");
2253 boolean is_cntrl = STREQ (str, "cntrl");
2254 boolean is_digit = STREQ (str, "digit");
2255 boolean is_graph = STREQ (str, "graph");
2256 boolean is_lower = STREQ (str, "lower");
2257 boolean is_print = STREQ (str, "print");
2258 boolean is_punct = STREQ (str, "punct");
2259 boolean is_space = STREQ (str, "space");
2260 boolean is_upper = STREQ (str, "upper");
2261 boolean is_xdigit = STREQ (str, "xdigit");
2262
2263 if (!IS_CHAR_CLASS (str))
2264 FREE_STACK_RETURN (REG_ECTYPE);
2265
2266 /* Throw away the ] at the end of the character
2267 class. */
2268 PATFETCH (c);
2269
2270 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2271
2272 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
2273 {
2274 /* This was split into 3 if's to
2275 avoid an arbitrary limit in some compiler. */
2276 if ( (is_alnum && ISALNUM (ch))
2277 || (is_alpha && ISALPHA (ch))
2278 || (is_blank && ISBLANK (ch))
2279 || (is_cntrl && ISCNTRL (ch)))
2280 SET_LIST_BIT (ch);
2281 if ( (is_digit && ISDIGIT (ch))
2282 || (is_graph && ISGRAPH (ch))
2283 || (is_lower && ISLOWER (ch))
2284 || (is_print && ISPRINT (ch)))
2285 SET_LIST_BIT (ch);
2286 if ( (is_punct && ISPUNCT (ch))
2287 || (is_space && ISSPACE (ch))
2288 || (is_upper && ISUPPER (ch))
2289 || (is_xdigit && ISXDIGIT (ch)))
2290 SET_LIST_BIT (ch);
2291 if ( translate && (is_upper || is_lower)
2292 && (ISUPPER (ch) || ISLOWER (ch)))
2293 SET_LIST_BIT (ch);
2294 }
2295 had_char_class = true;
2296 #endif /* libc || wctype.h */
2297 #endif /* BROKEN_LOCALE */
2298 }
2299 else
2300 {
2301 c1++;
2302 while (c1--)
2303 PATUNFETCH;
2304 SET_LIST_BIT ('[');
2305 SET_LIST_BIT (':');
2306 had_char_class = false;
2307 }
2308 }
2309 else
2310 {
2311 had_char_class = false;
2312 SET_LIST_BIT (c);
2313 }
2314 }
2315
2316 /* Discard any (non)matching list bytes that are all 0 at the
2317 end of the map. Decrease the map-length byte too. */
2318 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
2319 b[-1]--;
2320 b += b[-1];
2321 }
2322 break;
2323
2324
2325 case '(':
2326 if (syntax & RE_NO_BK_PARENS)
2327 goto handle_open;
2328 else
2329 goto normal_char;
2330
2331
2332 case ')':
2333 if (syntax & RE_NO_BK_PARENS)
2334 goto handle_close;
2335 else
2336 goto normal_char;
2337
2338
2339 case '\n':
2340 if (syntax & RE_NEWLINE_ALT)
2341 goto handle_alt;
2342 else
2343 goto normal_char;
2344
2345
2346 case '|':
2347 if (syntax & RE_NO_BK_VBAR)
2348 goto handle_alt;
2349 else
2350 goto normal_char;
2351
2352
2353 case '{':
2354 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
2355 goto handle_interval;
2356 else
2357 goto normal_char;
2358
2359
2360 case '\\':
2361 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2362
2363 /* Do not translate the character after the \, so that we can
2364 distinguish, e.g., \B from \b, even if we normally would
2365 translate, e.g., B to b. */
2366 PATFETCH_RAW (c);
2367
2368 switch (c)
2369 {
2370 case '(':
2371 if (syntax & RE_NO_BK_PARENS)
2372 goto normal_backslash;
2373
2374 handle_open:
2375 bufp->re_nsub++;
2376 regnum++;
2377
2378 if (COMPILE_STACK_FULL)
2379 {
2380 RETALLOC (compile_stack.stack, compile_stack.size << 1,
2381 compile_stack_elt_t);
2382 if (compile_stack.stack == NULL) return REG_ESPACE;
2383
2384 compile_stack.size <<= 1;
2385 }
2386
2387 /* These are the values to restore when we hit end of this
2388 group. They are all relative offsets, so that if the
2389 whole pattern moves because of realloc, they will still
2390 be valid. */
2391 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2392 COMPILE_STACK_TOP.fixup_alt_jump
2393 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2394 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2395 COMPILE_STACK_TOP.regnum = regnum;
2396
2397 /* We will eventually replace the 0 with the number of
2398 groups inner to this one. But do not push a
2399 start_memory for groups beyond the last one we can
2400 represent in the compiled pattern. */
2401 if (regnum <= MAX_REGNUM)
2402 {
2403 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2404 BUF_PUSH_3 (start_memory, regnum, 0);
2405 }
2406
2407 compile_stack.avail++;
2408
2409 fixup_alt_jump = 0;
2410 laststart = 0;
2411 begalt = b;
2412 /* If we've reached MAX_REGNUM groups, then this open
2413 won't actually generate any code, so we'll have to
2414 clear pending_exact explicitly. */
2415 pending_exact = 0;
2416 break;
2417
2418
2419 case ')':
2420 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
2421
2422 if (COMPILE_STACK_EMPTY)
2423 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2424 goto normal_backslash;
2425 else
2426 FREE_STACK_RETURN (REG_ERPAREN);
2427
2428 handle_close:
2429 if (fixup_alt_jump)
2430 { /* Push a dummy failure point at the end of the
2431 alternative for a possible future
2432 `pop_failure_jump' to pop. See comments at
2433 `push_dummy_failure' in `re_match_2'. */
2434 BUF_PUSH (push_dummy_failure);
2435
2436 /* We allocated space for this jump when we assigned
2437 to `fixup_alt_jump', in the `handle_alt' case below. */
2438 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2439 }
2440
2441 /* See similar code for backslashed left paren above. */
2442 if (COMPILE_STACK_EMPTY)
2443 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2444 goto normal_char;
2445 else
2446 FREE_STACK_RETURN (REG_ERPAREN);
2447
2448 /* Since we just checked for an empty stack above, this
2449 ``can't happen''. */
2450 assert (compile_stack.avail != 0);
2451 {
2452 /* We don't just want to restore into `regnum', because
2453 later groups should continue to be numbered higher,
2454 as in `(ab)c(de)' -- the second group is #2. */
2455 regnum_t this_group_regnum;
2456
2457 compile_stack.avail--;
2458 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2459 fixup_alt_jump
2460 = COMPILE_STACK_TOP.fixup_alt_jump
2461 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
2462 : 0;
2463 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2464 this_group_regnum = COMPILE_STACK_TOP.regnum;
2465 /* If we've reached MAX_REGNUM groups, then this open
2466 won't actually generate any code, so we'll have to
2467 clear pending_exact explicitly. */
2468 pending_exact = 0;
2469
2470 /* We're at the end of the group, so now we know how many
2471 groups were inside this one. */
2472 if (this_group_regnum <= MAX_REGNUM)
2473 {
2474 unsigned char *inner_group_loc
2475 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2476
2477 *inner_group_loc = regnum - this_group_regnum;
2478 BUF_PUSH_3 (stop_memory, this_group_regnum,
2479 regnum - this_group_regnum);
2480 }
2481 }
2482 break;
2483
2484
2485 case '|': /* `\|'. */
2486 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
2487 goto normal_backslash;
2488 handle_alt:
2489 if (syntax & RE_LIMITED_OPS)
2490 goto normal_char;
2491
2492 /* Insert before the previous alternative a jump which
2493 jumps to this alternative if the former fails. */
2494 GET_BUFFER_SPACE (3);
2495 INSERT_JUMP (on_failure_jump, begalt, b + 6);
2496 pending_exact = 0;
2497 b += 3;
2498
2499 /* The alternative before this one has a jump after it
2500 which gets executed if it gets matched. Adjust that
2501 jump so it will jump to this alternative's analogous
2502 jump (put in below, which in turn will jump to the next
2503 (if any) alternative's such jump, etc.). The last such
2504 jump jumps to the correct final destination. A picture:
2505 _____ _____
2506 | | | |
2507 | v | v
2508 a | b | c
2509
2510 If we are at `b', then fixup_alt_jump right now points to a
2511 three-byte space after `a'. We'll put in the jump, set
2512 fixup_alt_jump to right after `b', and leave behind three
2513 bytes which we'll fill in when we get to after `c'. */
2514
2515 if (fixup_alt_jump)
2516 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2517
2518 /* Mark and leave space for a jump after this alternative,
2519 to be filled in later either by next alternative or
2520 when know we're at the end of a series of alternatives. */
2521 fixup_alt_jump = b;
2522 GET_BUFFER_SPACE (3);
2523 b += 3;
2524
2525 laststart = 0;
2526 begalt = b;
2527 break;
2528
2529
2530 case '{':
2531 /* If \{ is a literal. */
2532 if (!(syntax & RE_INTERVALS)
2533 /* If we're at `\{' and it's not the open-interval
2534 operator. */
2535 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2536 || (p - 2 == pattern && p == pend))
2537 goto normal_backslash;
2538
2539 handle_interval:
2540 {
2541 /* If got here, then the syntax allows intervals. */
2542
2543 /* At least (most) this many matches must be made. */
2544 int lower_bound = -1, upper_bound = -1;
2545
2546 beg_interval = p - 1;
2547
2548 if (p == pend)
2549 {
2550 if (syntax & RE_NO_BK_BRACES)
2551 goto unfetch_interval;
2552 else
2553 FREE_STACK_RETURN (REG_EBRACE);
2554 }
2555
2556 GET_UNSIGNED_NUMBER (lower_bound);
2557
2558 if (c == ',')
2559 {
2560 GET_UNSIGNED_NUMBER (upper_bound);
2561 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
2562 }
2563 else
2564 /* Interval such as `{1}' => match exactly once. */
2565 upper_bound = lower_bound;
2566
2567 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
2568 || lower_bound > upper_bound)
2569 {
2570 if (syntax & RE_NO_BK_BRACES)
2571 goto unfetch_interval;
2572 else
2573 FREE_STACK_RETURN (REG_BADBR);
2574 }
2575
2576 if (!(syntax & RE_NO_BK_BRACES))
2577 {
2578 if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
2579
2580 PATFETCH (c);
2581 }
2582
2583 if (c != '}')
2584 {
2585 if (syntax & RE_NO_BK_BRACES)
2586 goto unfetch_interval;
2587 else
2588 FREE_STACK_RETURN (REG_BADBR);
2589 }
2590
2591 /* We just parsed a valid interval. */
2592
2593 /* If it's invalid to have no preceding re. */
2594 if (!laststart)
2595 {
2596 if (syntax & RE_CONTEXT_INVALID_OPS)
2597 FREE_STACK_RETURN (REG_BADRPT);
2598 else if (syntax & RE_CONTEXT_INDEP_OPS)
2599 laststart = b;
2600 else
2601 goto unfetch_interval;
2602 }
2603
2604 /* If the upper bound is zero, don't want to succeed at
2605 all; jump from `laststart' to `b + 3', which will be
2606 the end of the buffer after we insert the jump. */
2607 if (upper_bound == 0)
2608 {
2609 GET_BUFFER_SPACE (3);
2610 INSERT_JUMP (jump, laststart, b + 3);
2611 b += 3;
2612 }
2613
2614 /* Otherwise, we have a nontrivial interval. When
2615 we're all done, the pattern will look like:
2616 set_number_at <jump count> <upper bound>
2617 set_number_at <succeed_n count> <lower bound>
2618 succeed_n <after jump addr> <succeed_n count>
2619 <body of loop>
2620 jump_n <succeed_n addr> <jump count>
2621 (The upper bound and `jump_n' are omitted if
2622 `upper_bound' is 1, though.) */
2623 else
2624 { /* If the upper bound is > 1, we need to insert
2625 more at the end of the loop. */
2626 unsigned nbytes = 10 + (upper_bound > 1) * 10;
2627
2628 GET_BUFFER_SPACE (nbytes);
2629
2630 /* Initialize lower bound of the `succeed_n', even
2631 though it will be set during matching by its
2632 attendant `set_number_at' (inserted next),
2633 because `re_compile_fastmap' needs to know.
2634 Jump to the `jump_n' we might insert below. */
2635 INSERT_JUMP2 (succeed_n, laststart,
2636 b + 5 + (upper_bound > 1) * 5,
2637 lower_bound);
2638 b += 5;
2639
2640 /* Code to initialize the lower bound. Insert
2641 before the `succeed_n'. The `5' is the last two
2642 bytes of this `set_number_at', plus 3 bytes of
2643 the following `succeed_n'. */
2644 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2645 b += 5;
2646
2647 if (upper_bound > 1)
2648 { /* More than one repetition is allowed, so
2649 append a backward jump to the `succeed_n'
2650 that starts this interval.
2651
2652 When we've reached this during matching,
2653 we'll have matched the interval once, so
2654 jump back only `upper_bound - 1' times. */
2655 STORE_JUMP2 (jump_n, b, laststart + 5,
2656 upper_bound - 1);
2657 b += 5;
2658
2659 /* The location we want to set is the second
2660 parameter of the `jump_n'; that is `b-2' as
2661 an absolute address. `laststart' will be
2662 the `set_number_at' we're about to insert;
2663 `laststart+3' the number to set, the source
2664 for the relative address. But we are
2665 inserting into the middle of the pattern --
2666 so everything is getting moved up by 5.
2667 Conclusion: (b - 2) - (laststart + 3) + 5,
2668 i.e., b - laststart.
2669
2670 We insert this at the beginning of the loop
2671 so that if we fail during matching, we'll
2672 reinitialize the bounds. */
2673 insert_op2 (set_number_at, laststart, b - laststart,
2674 upper_bound - 1, b);
2675 b += 5;
2676 }
2677 }
2678 pending_exact = 0;
2679 beg_interval = NULL;
2680 }
2681 break;
2682
2683 unfetch_interval:
2684 /* If an invalid interval, match the characters as literals. */
2685 assert (beg_interval);
2686 p = beg_interval;
2687 beg_interval = NULL;
2688
2689 /* normal_char and normal_backslash need `c'. */
2690 PATFETCH (c);
2691
2692 if (!(syntax & RE_NO_BK_BRACES))
2693 {
2694 if (p > pattern && p[-1] == '\\')
2695 goto normal_backslash;
2696 }
2697 goto normal_char;
2698
2699 #ifdef emacs
2700 /* There is no way to specify the before_dot and after_dot
2701 operators. rms says this is ok. --karl */
2702 case '=':
2703 BUF_PUSH (at_dot);
2704 break;
2705
2706 case 's':
2707 laststart = b;
2708 PATFETCH (c);
2709 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2710 break;
2711
2712 case 'S':
2713 laststart = b;
2714 PATFETCH (c);
2715 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2716 break;
2717 #endif /* emacs */
2718
2719
2720 case 'w':
2721 if (re_syntax_options & RE_NO_GNU_OPS)
2722 goto normal_char;
2723 laststart = b;
2724 BUF_PUSH (wordchar);
2725 break;
2726
2727
2728 case 'W':
2729 if (re_syntax_options & RE_NO_GNU_OPS)
2730 goto normal_char;
2731 laststart = b;
2732 BUF_PUSH (notwordchar);
2733 break;
2734
2735
2736 case '<':
2737 if (re_syntax_options & RE_NO_GNU_OPS)
2738 goto normal_char;
2739 BUF_PUSH (wordbeg);
2740 break;
2741
2742 case '>':
2743 if (re_syntax_options & RE_NO_GNU_OPS)
2744 goto normal_char;
2745 BUF_PUSH (wordend);
2746 break;
2747
2748 case 'b':
2749 if (re_syntax_options & RE_NO_GNU_OPS)
2750 goto normal_char;
2751 BUF_PUSH (wordbound);
2752 break;
2753
2754 case 'B':
2755 if (re_syntax_options & RE_NO_GNU_OPS)
2756 goto normal_char;
2757 BUF_PUSH (notwordbound);
2758 break;
2759
2760 case '`':
2761 if (re_syntax_options & RE_NO_GNU_OPS)
2762 goto normal_char;
2763 BUF_PUSH (begbuf);
2764 break;
2765
2766 case '\'':
2767 if (re_syntax_options & RE_NO_GNU_OPS)
2768 goto normal_char;
2769 BUF_PUSH (endbuf);
2770 break;
2771
2772 case '1': case '2': case '3': case '4': case '5':
2773 case '6': case '7': case '8': case '9':
2774 if (syntax & RE_NO_BK_REFS)
2775 goto normal_char;
2776
2777 c1 = c - '0';
2778
2779 if (c1 > regnum)
2780 FREE_STACK_RETURN (REG_ESUBREG);
2781
2782 /* Can't back reference to a subexpression if inside of it. */
2783 if (group_in_compile_stack (compile_stack, (regnum_t) c1))
2784 goto normal_char;
2785
2786 laststart = b;
2787 BUF_PUSH_2 (duplicate, c1);
2788 break;
2789
2790
2791 case '+':
2792 case '?':
2793 if (syntax & RE_BK_PLUS_QM)
2794 goto handle_plus;
2795 else
2796 goto normal_backslash;
2797
2798 default:
2799 normal_backslash:
2800 /* You might think it would be useful for \ to mean
2801 not to translate; but if we don't translate it
2802 it will never match anything. */
2803 c = TRANSLATE (c);
2804 goto normal_char;
2805 }
2806 break;
2807
2808
2809 default:
2810 /* Expects the character in `c'. */
2811 normal_char:
2812 /* If no exactn currently being built. */
2813 if (!pending_exact
2814
2815 /* If last exactn not at current position. */
2816 || pending_exact + *pending_exact + 1 != b
2817
2818 /* We have only one byte following the exactn for the count. */
2819 || *pending_exact == (1 << BYTEWIDTH) - 1
2820
2821 /* If followed by a repetition operator. */
2822 || *p == '*' || *p == '^'
2823 || ((syntax & RE_BK_PLUS_QM)
2824 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2825 : (*p == '+' || *p == '?'))
2826 || ((syntax & RE_INTERVALS)
2827 && ((syntax & RE_NO_BK_BRACES)
2828 ? *p == '{'
2829 : (p[0] == '\\' && p[1] == '{'))))
2830 {
2831 /* Start building a new exactn. */
2832
2833 laststart = b;
2834
2835 BUF_PUSH_2 (exactn, 0);
2836 pending_exact = b - 1;
2837 }
2838
2839 BUF_PUSH (c);
2840 (*pending_exact)++;
2841 break;
2842 } /* switch (c) */
2843 } /* while p != pend */
2844
2845
2846 /* Through the pattern now. */
2847
2848 if (fixup_alt_jump)
2849 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2850
2851 if (!COMPILE_STACK_EMPTY)
2852 FREE_STACK_RETURN (REG_EPAREN);
2853
2854 /* If we don't want backtracking, force success
2855 the first time we reach the end of the compiled pattern. */
2856 if (syntax & RE_NO_POSIX_BACKTRACKING)
2857 BUF_PUSH (succeed);
2858
2859 free (compile_stack.stack);
2860
2861 /* We have succeeded; set the length of the buffer. */
2862 bufp->used = b - bufp->buffer;
2863
2864 #ifdef DEBUG
2865 if (debug)
2866 {
2867 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2868 print_compiled_pattern (bufp);
2869 }
2870 #endif /* DEBUG */
2871
2872 #ifndef MATCH_MAY_ALLOCATE
2873 /* Initialize the failure stack to the largest possible stack. This
2874 isn't necessary unless we're trying to avoid calling alloca in
2875 the search and match routines. */
2876 {
2877 int num_regs = bufp->re_nsub + 1;
2878
2879 /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2880 is strictly greater than re_max_failures, the largest possible stack
2881 is 2 * re_max_failures failure points. */
2882 if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
2883 {
2884 fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2885
2886 #ifdef emacs
2887 if (! fail_stack.stack)
2888 fail_stack.stack
2889 = (fail_stack_elt_t *) xmalloc (fail_stack.size
2890 * sizeof (fail_stack_elt_t));
2891 else
2892 fail_stack.stack
2893 = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
2894 (fail_stack.size
2895 * sizeof (fail_stack_elt_t)));
2896 #else /* not emacs */
2897 if (! fail_stack.stack)
2898 fail_stack.stack
2899 = (fail_stack_elt_t *) malloc (fail_stack.size
2900 * sizeof (fail_stack_elt_t));
2901 else
2902 fail_stack.stack
2903 = (fail_stack_elt_t *) realloc (fail_stack.stack,
2904 (fail_stack.size
2905 * sizeof (fail_stack_elt_t)));
2906 #endif /* not emacs */
2907 }
2908
2909 regex_grow_registers (num_regs);
2910 }
2911 #endif /* not MATCH_MAY_ALLOCATE */
2912
2913 return REG_NOERROR;
2914 } /* regex_compile */
2915
2916 /* Subroutines for `regex_compile'. */
2917
2918 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2919
2920 static void
store_op1(op,loc,arg)2921 store_op1 (op, loc, arg)
2922 re_opcode_t op;
2923 unsigned char *loc;
2924 int arg;
2925 {
2926 *loc = (unsigned char) op;
2927 STORE_NUMBER (loc + 1, arg);
2928 }
2929
2930
2931 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2932
2933 static void
store_op2(op,loc,arg1,arg2)2934 store_op2 (op, loc, arg1, arg2)
2935 re_opcode_t op;
2936 unsigned char *loc;
2937 int arg1, arg2;
2938 {
2939 *loc = (unsigned char) op;
2940 STORE_NUMBER (loc + 1, arg1);
2941 STORE_NUMBER (loc + 3, arg2);
2942 }
2943
2944
2945 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2946 for OP followed by two-byte integer parameter ARG. */
2947
2948 static void
insert_op1(op,loc,arg,end)2949 insert_op1 (op, loc, arg, end)
2950 re_opcode_t op;
2951 unsigned char *loc;
2952 int arg;
2953 unsigned char *end;
2954 {
2955 register unsigned char *pfrom = end;
2956 register unsigned char *pto = end + 3;
2957
2958 while (pfrom != loc)
2959 *--pto = *--pfrom;
2960
2961 store_op1 (op, loc, arg);
2962 }
2963
2964
2965 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2966
2967 static void
insert_op2(op,loc,arg1,arg2,end)2968 insert_op2 (op, loc, arg1, arg2, end)
2969 re_opcode_t op;
2970 unsigned char *loc;
2971 int arg1, arg2;
2972 unsigned char *end;
2973 {
2974 register unsigned char *pfrom = end;
2975 register unsigned char *pto = end + 5;
2976
2977 while (pfrom != loc)
2978 *--pto = *--pfrom;
2979
2980 store_op2 (op, loc, arg1, arg2);
2981 }
2982
2983
2984 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2985 after an alternative or a begin-subexpression. We assume there is at
2986 least one character before the ^. */
2987
2988 static boolean
at_begline_loc_p(pattern,p,syntax)2989 at_begline_loc_p (pattern, p, syntax)
2990 const char *pattern, *p;
2991 reg_syntax_t syntax;
2992 {
2993 const char *prev = p - 2;
2994 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2995
2996 return
2997 /* After a subexpression? */
2998 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2999 /* After an alternative? */
3000 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
3001 }
3002
3003
3004 /* The dual of at_begline_loc_p. This one is for $. We assume there is
3005 at least one character after the $, i.e., `P < PEND'. */
3006
3007 static boolean
at_endline_loc_p(p,pend,syntax)3008 at_endline_loc_p (p, pend, syntax)
3009 const char *p, *pend;
3010 reg_syntax_t syntax;
3011 {
3012 const char *next = p;
3013 boolean next_backslash = *next == '\\';
3014 const char *next_next = p + 1 < pend ? p + 1 : 0;
3015
3016 return
3017 /* Before a subexpression? */
3018 (syntax & RE_NO_BK_PARENS ? *next == ')'
3019 : next_backslash && next_next && *next_next == ')')
3020 /* Before an alternative? */
3021 || (syntax & RE_NO_BK_VBAR ? *next == '|'
3022 : next_backslash && next_next && *next_next == '|');
3023 }
3024
3025
3026 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
3027 false if it's not. */
3028
3029 static boolean
group_in_compile_stack(compile_stack,regnum)3030 group_in_compile_stack (compile_stack, regnum)
3031 compile_stack_type compile_stack;
3032 regnum_t regnum;
3033 {
3034 int this_element;
3035
3036 for (this_element = compile_stack.avail - 1;
3037 this_element >= 0;
3038 this_element--)
3039 if (compile_stack.stack[this_element].regnum == regnum)
3040 return true;
3041
3042 return false;
3043 }
3044
3045
3046 /* Read the ending character of a range (in a bracket expression) from the
3047 uncompiled pattern *P_PTR (which ends at PEND). We assume the
3048 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
3049 Then we set the translation of all bits between the starting and
3050 ending characters (inclusive) in the compiled pattern B.
3051
3052 Return an error code.
3053
3054 We use these short variable names so we can use the same macros as
3055 `regex_compile' itself. */
3056
3057 static reg_errcode_t
compile_range(p_ptr,pend,translate,syntax,b)3058 compile_range (p_ptr, pend, translate, syntax, b)
3059 const char **p_ptr, *pend;
3060 RE_TRANSLATE_TYPE translate;
3061 reg_syntax_t syntax;
3062 unsigned char *b;
3063 {
3064 unsigned this_char;
3065
3066 const char *p = *p_ptr;
3067 unsigned int range_start, range_end;
3068
3069 if (p == pend)
3070 return REG_ERANGE;
3071
3072 /* Even though the pattern is a signed `char *', we need to fetch
3073 with unsigned char *'s; if the high bit of the pattern character
3074 is set, the range endpoints will be negative if we fetch using a
3075 signed char *.
3076
3077 We also want to fetch the endpoints without translating them; the
3078 appropriate translation is done in the bit-setting loop below. */
3079 /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *. */
3080 range_start = ((const unsigned char *) p)[-2];
3081 range_end = ((const unsigned char *) p)[0];
3082
3083 /* Have to increment the pointer into the pattern string, so the
3084 caller isn't still at the ending character. */
3085 (*p_ptr)++;
3086
3087 /* If the start is after the end, the range is empty. */
3088 if (range_start > range_end)
3089 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
3090
3091 /* Here we see why `this_char' has to be larger than an `unsigned
3092 char' -- the range is inclusive, so if `range_end' == 0xff
3093 (assuming 8-bit characters), we would otherwise go into an infinite
3094 loop, since all characters <= 0xff. */
3095 for (this_char = range_start; this_char <= range_end; this_char++)
3096 {
3097 SET_LIST_BIT (TRANSLATE (this_char));
3098 }
3099
3100 return REG_NOERROR;
3101 }
3102
3103 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
3104 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
3105 characters can start a string that matches the pattern. This fastmap
3106 is used by re_search to skip quickly over impossible starting points.
3107
3108 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
3109 area as BUFP->fastmap.
3110
3111 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
3112 the pattern buffer.
3113
3114 Returns 0 if we succeed, -2 if an internal error. */
3115
3116 int
re_compile_fastmap(bufp)3117 re_compile_fastmap (bufp)
3118 struct re_pattern_buffer *bufp;
3119 {
3120 int j, k;
3121 #ifdef MATCH_MAY_ALLOCATE
3122 fail_stack_type fail_stack;
3123 #endif
3124 #ifndef REGEX_MALLOC
3125 char *destination;
3126 #endif
3127 /* We don't push any register information onto the failure stack. */
3128 /* unsigned num_regs = 0; superfluous */
3129
3130 register char *fastmap = bufp->fastmap;
3131 unsigned char *pattern = bufp->buffer;
3132 unsigned char *p = pattern;
3133 register unsigned char *pend = pattern + bufp->used;
3134
3135 #ifdef REL_ALLOC
3136 /* This holds the pointer to the failure stack, when
3137 it is allocated relocatably. */
3138 fail_stack_elt_t *failure_stack_ptr;
3139 #endif
3140
3141 /* Assume that each path through the pattern can be null until
3142 proven otherwise. We set this false at the bottom of switch
3143 statement, to which we get only if a particular path doesn't
3144 match the empty string. */
3145 boolean path_can_be_null = true;
3146
3147 /* We aren't doing a `succeed_n' to begin with. */
3148 boolean succeed_n_p = false;
3149
3150 assert (fastmap != NULL && p != NULL);
3151
3152 INIT_FAIL_STACK ();
3153 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
3154 bufp->fastmap_accurate = 1; /* It will be when we're done. */
3155 bufp->can_be_null = 0;
3156
3157 while (1)
3158 {
3159 if (p == pend || *p == succeed)
3160 {
3161 /* We have reached the (effective) end of pattern. */
3162 if (!FAIL_STACK_EMPTY ())
3163 {
3164 bufp->can_be_null |= path_can_be_null;
3165
3166 /* Reset for next path. */
3167 path_can_be_null = true;
3168
3169 p = fail_stack.stack[--fail_stack.avail].pointer;
3170
3171 continue;
3172 }
3173 else
3174 break;
3175 }
3176
3177 /* We should never be about to go beyond the end of the pattern. */
3178 assert (p < pend);
3179
3180 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
3181 {
3182
3183 /* I guess the idea here is to simply not bother with a fastmap
3184 if a backreference is used, since it's too hard to figure out
3185 the fastmap for the corresponding group. Setting
3186 `can_be_null' stops `re_search_2' from using the fastmap, so
3187 that is all we do. */
3188 case duplicate:
3189 bufp->can_be_null = 1;
3190 goto done;
3191
3192
3193 /* Following are the cases which match a character. These end
3194 with `break'. */
3195
3196 case exactn:
3197 fastmap[p[1]] = 1;
3198 break;
3199
3200
3201 case charset:
3202 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
3203 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
3204 fastmap[j] = 1;
3205 break;
3206
3207
3208 case charset_not:
3209 /* Chars beyond end of map must be allowed. */
3210 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
3211 fastmap[j] = 1;
3212
3213 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
3214 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
3215 fastmap[j] = 1;
3216 break;
3217
3218
3219 case wordchar:
3220 for (j = 0; j < (1 << BYTEWIDTH); j++)
3221 if (SYNTAX (j) == Sword)
3222 fastmap[j] = 1;
3223 break;
3224
3225
3226 case notwordchar:
3227 for (j = 0; j < (1 << BYTEWIDTH); j++)
3228 if (SYNTAX (j) != Sword)
3229 fastmap[j] = 1;
3230 break;
3231
3232
3233 case anychar:
3234 {
3235 int fastmap_newline = fastmap['\n'];
3236
3237 /* `.' matches anything ... */
3238 for (j = 0; j < (1 << BYTEWIDTH); j++)
3239 fastmap[j] = 1;
3240
3241 /* ... except perhaps newline. */
3242 if (!(bufp->syntax & RE_DOT_NEWLINE))
3243 fastmap['\n'] = fastmap_newline;
3244
3245 /* Return if we have already set `can_be_null'; if we have,
3246 then the fastmap is irrelevant. Something's wrong here. */
3247 else if (bufp->can_be_null)
3248 goto done;
3249
3250 /* Otherwise, have to check alternative paths. */
3251 break;
3252 }
3253
3254 #ifdef emacs
3255 case syntaxspec:
3256 k = *p++;
3257 for (j = 0; j < (1 << BYTEWIDTH); j++)
3258 if (SYNTAX (j) == (enum syntaxcode) k)
3259 fastmap[j] = 1;
3260 break;
3261
3262
3263 case notsyntaxspec:
3264 k = *p++;
3265 for (j = 0; j < (1 << BYTEWIDTH); j++)
3266 if (SYNTAX (j) != (enum syntaxcode) k)
3267 fastmap[j] = 1;
3268 break;
3269
3270
3271 /* All cases after this match the empty string. These end with
3272 `continue'. */
3273
3274
3275 case before_dot:
3276 case at_dot:
3277 case after_dot:
3278 continue;
3279 #endif /* emacs */
3280
3281
3282 case no_op:
3283 case begline:
3284 case endline:
3285 case begbuf:
3286 case endbuf:
3287 case wordbound:
3288 case notwordbound:
3289 case wordbeg:
3290 case wordend:
3291 case push_dummy_failure:
3292 continue;
3293
3294
3295 case jump_n:
3296 case pop_failure_jump:
3297 case maybe_pop_jump:
3298 case jump:
3299 case jump_past_alt:
3300 case dummy_failure_jump:
3301 EXTRACT_NUMBER_AND_INCR (j, p);
3302 p += j;
3303 if (j > 0)
3304 continue;
3305
3306 /* Jump backward implies we just went through the body of a
3307 loop and matched nothing. Opcode jumped to should be
3308 `on_failure_jump' or `succeed_n'. Just treat it like an
3309 ordinary jump. For a * loop, it has pushed its failure
3310 point already; if so, discard that as redundant. */
3311 if ((re_opcode_t) *p != on_failure_jump
3312 && (re_opcode_t) *p != succeed_n)
3313 continue;
3314
3315 p++;
3316 EXTRACT_NUMBER_AND_INCR (j, p);
3317 p += j;
3318
3319 /* If what's on the stack is where we are now, pop it. */
3320 if (!FAIL_STACK_EMPTY ()
3321 && fail_stack.stack[fail_stack.avail - 1].pointer == p)
3322 fail_stack.avail--;
3323
3324 continue;
3325
3326
3327 case on_failure_jump:
3328 case on_failure_keep_string_jump:
3329 handle_on_failure_jump:
3330 EXTRACT_NUMBER_AND_INCR (j, p);
3331
3332 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
3333 end of the pattern. We don't want to push such a point,
3334 since when we restore it above, entering the switch will
3335 increment `p' past the end of the pattern. We don't need
3336 to push such a point since we obviously won't find any more
3337 fastmap entries beyond `pend'. Such a pattern can match
3338 the null string, though. */
3339 if (p + j < pend)
3340 {
3341 if (!PUSH_PATTERN_OP (p + j, fail_stack))
3342 {
3343 RESET_FAIL_STACK ();
3344 return -2;
3345 }
3346 }
3347 else
3348 bufp->can_be_null = 1;
3349
3350 if (succeed_n_p)
3351 {
3352 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
3353 succeed_n_p = false;
3354 }
3355
3356 continue;
3357
3358
3359 case succeed_n:
3360 /* Get to the number of times to succeed. */
3361 p += 2;
3362
3363 /* Increment p past the n for when k != 0. */
3364 EXTRACT_NUMBER_AND_INCR (k, p);
3365 if (k == 0)
3366 {
3367 p -= 4;
3368 succeed_n_p = true; /* Spaghetti code alert. */
3369 goto handle_on_failure_jump;
3370 }
3371 continue;
3372
3373
3374 case set_number_at:
3375 p += 4;
3376 continue;
3377
3378
3379 case start_memory:
3380 case stop_memory:
3381 p += 2;
3382 continue;
3383
3384
3385 default:
3386 call_abort (); /* We have listed all the cases. */
3387 } /* switch *p++ */
3388
3389 /* Getting here means we have found the possible starting
3390 characters for one path of the pattern -- and that the empty
3391 string does not match. We need not follow this path further.
3392 Instead, look at the next alternative (remembered on the
3393 stack), or quit if no more. The test at the top of the loop
3394 does these things. */
3395 path_can_be_null = false;
3396 p = pend;
3397 } /* while p */
3398
3399 /* Set `can_be_null' for the last path (also the first path, if the
3400 pattern is empty). */
3401 bufp->can_be_null |= path_can_be_null;
3402
3403 done:
3404 RESET_FAIL_STACK ();
3405 return 0;
3406 } /* re_compile_fastmap */
3407
3408 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
3409 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
3410 this memory for recording register information. STARTS and ENDS
3411 must be allocated using the malloc library routine, and must each
3412 be at least NUM_REGS * sizeof (regoff_t) bytes long.
3413
3414 If NUM_REGS == 0, then subsequent matches should allocate their own
3415 register data.
3416
3417 Unless this function is called, the first search or match using
3418 PATTERN_BUFFER will allocate its own register data, without
3419 freeing the old data. */
3420
3421 void
re_set_registers(bufp,regs,num_regs,starts,ends)3422 re_set_registers (bufp, regs, num_regs, starts, ends)
3423 struct re_pattern_buffer *bufp;
3424 struct re_registers *regs;
3425 unsigned num_regs;
3426 regoff_t *starts, *ends;
3427 {
3428 if (num_regs)
3429 {
3430 bufp->regs_allocated = REGS_REALLOCATE;
3431 regs->num_regs = num_regs;
3432 regs->start = starts;
3433 regs->end = ends;
3434 }
3435 else
3436 {
3437 bufp->regs_allocated = REGS_UNALLOCATED;
3438 regs->num_regs = 0;
3439 regs->start = regs->end = (regoff_t *) 0;
3440 }
3441 }
3442
3443 /* Searching routines. */
3444
3445 /* Like re_search_2, below, but only one string is specified, and
3446 doesn't let you say where to stop matching. */
3447
3448 int
re_search(bufp,string,size,startpos,range,regs)3449 re_search (bufp, string, size, startpos, range, regs)
3450 struct re_pattern_buffer *bufp;
3451 const char *string;
3452 int size, startpos, range;
3453 struct re_registers *regs;
3454 {
3455 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3456 regs, size);
3457 }
3458
3459
3460 /* Using the compiled pattern in BUFP->buffer, first tries to match the
3461 virtual concatenation of STRING1 and STRING2, starting first at index
3462 STARTPOS, then at STARTPOS + 1, and so on.
3463
3464 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3465
3466 RANGE is how far to scan while trying to match. RANGE = 0 means try
3467 only at STARTPOS; in general, the last start tried is STARTPOS +
3468 RANGE.
3469
3470 In REGS, return the indices of the virtual concatenation of STRING1
3471 and STRING2 that matched the entire BUFP->buffer and its contained
3472 subexpressions.
3473
3474 Do not consider matching one past the index STOP in the virtual
3475 concatenation of STRING1 and STRING2.
3476
3477 We return either the position in the strings at which the match was
3478 found, -1 if no match, or -2 if error (such as failure
3479 stack overflow). */
3480
3481 int
re_search_2(bufp,string1,size1,string2,size2,startpos,range,regs,stop)3482 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3483 struct re_pattern_buffer *bufp;
3484 const char *string1, *string2;
3485 int size1, size2;
3486 int startpos;
3487 int range;
3488 struct re_registers *regs;
3489 int stop;
3490 {
3491 int val;
3492 register char *fastmap = bufp->fastmap;
3493 register RE_TRANSLATE_TYPE translate = bufp->translate;
3494 int total_size = size1 + size2;
3495 int endpos = startpos + range;
3496
3497 /* Check for out-of-range STARTPOS. */
3498 if (startpos < 0 || startpos > total_size)
3499 return -1;
3500
3501 /* Fix up RANGE if it might eventually take us outside
3502 the virtual concatenation of STRING1 and STRING2.
3503 Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE. */
3504 if (endpos < 0)
3505 range = 0 - startpos;
3506 else if (endpos > total_size)
3507 range = total_size - startpos;
3508
3509 /* If the search isn't to be a backwards one, don't waste time in a
3510 search for a pattern that must be anchored. */
3511 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3512 {
3513 if (startpos > 0)
3514 return -1;
3515 else
3516 range = 1;
3517 }
3518
3519 #ifdef emacs
3520 /* In a forward search for something that starts with \=.
3521 don't keep searching past point. */
3522 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0)
3523 {
3524 range = PT - startpos;
3525 if (range <= 0)
3526 return -1;
3527 }
3528 #endif /* emacs */
3529
3530 /* Update the fastmap now if not correct already. */
3531 if (fastmap && !bufp->fastmap_accurate)
3532 if (re_compile_fastmap (bufp) == -2)
3533 return -2;
3534
3535 /* Loop through the string, looking for a place to start matching. */
3536 for (;;)
3537 {
3538 /* If a fastmap is supplied, skip quickly over characters that
3539 cannot be the start of a match. If the pattern can match the
3540 null string, however, we don't need to skip characters; we want
3541 the first null string. */
3542 if (fastmap && startpos < total_size && !bufp->can_be_null)
3543 {
3544 if (range > 0) /* Searching forwards. */
3545 {
3546 register const char *d;
3547 register int lim = 0;
3548 int irange = range;
3549
3550 if (startpos < size1 && startpos + range >= size1)
3551 lim = range - (size1 - startpos);
3552
3553 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3554
3555 /* Written out as an if-else to avoid testing `translate'
3556 inside the loop. */
3557 if (translate)
3558 while (range > lim
3559 && !fastmap[(unsigned char)
3560 translate[(unsigned char) *d++]])
3561 range--;
3562 else
3563 while (range > lim && !fastmap[(unsigned char) *d++])
3564 range--;
3565
3566 startpos += irange - range;
3567 }
3568 else /* Searching backwards. */
3569 {
3570 register char c = (size1 == 0 || startpos >= size1
3571 ? string2[startpos - size1]
3572 : string1[startpos]);
3573
3574 if (!fastmap[(unsigned char) TRANSLATE (c)])
3575 goto advance;
3576 }
3577 }
3578
3579 /* If can't match the null string, and that's all we have left, fail. */
3580 if (range >= 0 && startpos == total_size && fastmap
3581 && !bufp->can_be_null)
3582 return -1;
3583
3584 val = re_match_2_internal (bufp, string1, size1, string2, size2,
3585 startpos, regs, stop);
3586 #ifndef REGEX_MALLOC
3587 #ifdef C_ALLOCA
3588 alloca (0);
3589 #endif
3590 #endif
3591
3592 if (val >= 0)
3593 return startpos;
3594
3595 if (val == -2)
3596 return -2;
3597
3598 advance:
3599 if (!range)
3600 break;
3601 else if (range > 0)
3602 {
3603 range--;
3604 startpos++;
3605 }
3606 else
3607 {
3608 range++;
3609 startpos--;
3610 }
3611 }
3612 return -1;
3613 } /* re_search_2 */
3614
3615 /* This converts PTR, a pointer into one of the search strings `string1'
3616 and `string2' into an offset from the beginning of that string. */
3617 #define POINTER_TO_OFFSET(ptr) \
3618 (FIRST_STRING_P (ptr) \
3619 ? ((regoff_t) ((ptr) - string1)) \
3620 : ((regoff_t) ((ptr) - string2 + size1)))
3621
3622 /* Macros for dealing with the split strings in re_match_2. */
3623
3624 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3625
3626 /* Call before fetching a character with *d. This switches over to
3627 string2 if necessary. */
3628 #define PREFETCH() \
3629 while (d == dend) \
3630 { \
3631 /* End of string2 => fail. */ \
3632 if (dend == end_match_2) \
3633 goto fail; \
3634 /* End of string1 => advance to string2. */ \
3635 d = string2; \
3636 dend = end_match_2; \
3637 }
3638
3639
3640 /* Test if at very beginning or at very end of the virtual concatenation
3641 of `string1' and `string2'. If only one string, it's `string2'. */
3642 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3643 #define AT_STRINGS_END(d) ((d) == end2)
3644
3645
3646 /* Test if D points to a character which is word-constituent. We have
3647 two special cases to check for: if past the end of string1, look at
3648 the first character in string2; and if before the beginning of
3649 string2, look at the last character in string1. */
3650 #define WORDCHAR_P(d) \
3651 (SYNTAX ((d) == end1 ? *string2 \
3652 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3653 == Sword)
3654
3655 /* Disabled due to a compiler bug -- see comment at case wordbound */
3656 #if 0
3657 /* Test if the character before D and the one at D differ with respect
3658 to being word-constituent. */
3659 #define AT_WORD_BOUNDARY(d) \
3660 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3661 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3662 #endif
3663
3664 /* Free everything we malloc. */
3665 #ifdef MATCH_MAY_ALLOCATE
3666 #define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
3667 #define FREE_VARIABLES() \
3668 do { \
3669 REGEX_FREE_STACK (fail_stack.stack); \
3670 FREE_VAR (regstart); \
3671 FREE_VAR (regend); \
3672 FREE_VAR (old_regstart); \
3673 FREE_VAR (old_regend); \
3674 FREE_VAR (best_regstart); \
3675 FREE_VAR (best_regend); \
3676 FREE_VAR (reg_info); \
3677 FREE_VAR (reg_dummy); \
3678 FREE_VAR (reg_info_dummy); \
3679 } while (0)
3680 #else
3681 #define FREE_VARIABLES() ((void)0) /* Do nothing! But inhibit gcc warning. */
3682 #endif /* not MATCH_MAY_ALLOCATE */
3683
3684 /* These values must meet several constraints. They must not be valid
3685 register values; since we have a limit of 255 registers (because
3686 we use only one byte in the pattern for the register number), we can
3687 use numbers larger than 255. They must differ by 1, because of
3688 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3689 be larger than the value for the highest register, so we do not try
3690 to actually save any registers when none are active. */
3691 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3692 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3693
3694 /* Matching routines. */
3695
3696 #ifndef emacs /* Emacs never uses this. */
3697 /* re_match is like re_match_2 except it takes only a single string. */
3698
3699 int
re_match(bufp,string,size,pos,regs)3700 re_match (bufp, string, size, pos, regs)
3701 struct re_pattern_buffer *bufp;
3702 const char *string;
3703 int size, pos;
3704 struct re_registers *regs;
3705 {
3706 int result = re_match_2_internal (bufp, NULL, 0, string, size,
3707 pos, regs, size);
3708 #ifndef REGEX_MALLOC
3709 #ifdef C_ALLOCA
3710 alloca (0);
3711 #endif
3712 #endif
3713 return result;
3714 }
3715 #endif /* not emacs */
3716
3717 static boolean group_match_null_string_p _RE_ARGS ((unsigned char **p,
3718 unsigned char *end,
3719 register_info_type *reg_info));
3720 static boolean alt_match_null_string_p _RE_ARGS ((unsigned char *p,
3721 unsigned char *end,
3722 register_info_type *reg_info));
3723 static boolean common_op_match_null_string_p _RE_ARGS ((unsigned char **p,
3724 unsigned char *end,
3725 register_info_type *reg_info));
3726 static int bcmp_translate _RE_ARGS ((const char *s1, const char *s2,
3727 int len, char *translate));
3728
3729 /* re_match_2 matches the compiled pattern in BUFP against the
3730 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3731 and SIZE2, respectively). We start matching at POS, and stop
3732 matching at STOP.
3733
3734 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3735 store offsets for the substring each group matched in REGS. See the
3736 documentation for exactly how many groups we fill.
3737
3738 We return -1 if no match, -2 if an internal error (such as the
3739 failure stack overflowing). Otherwise, we return the length of the
3740 matched substring. */
3741
3742 int
re_match_2(bufp,string1,size1,string2,size2,pos,regs,stop)3743 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3744 struct re_pattern_buffer *bufp;
3745 const char *string1, *string2;
3746 int size1, size2;
3747 int pos;
3748 struct re_registers *regs;
3749 int stop;
3750 {
3751 int result = re_match_2_internal (bufp, string1, size1, string2, size2,
3752 pos, regs, stop);
3753 #ifndef REGEX_MALLOC
3754 #ifdef C_ALLOCA
3755 alloca (0);
3756 #endif
3757 #endif
3758 return result;
3759 }
3760
3761 /* This is a separate function so that we can force an alloca cleanup
3762 afterwards. */
3763 static int
re_match_2_internal(bufp,string1,size1,string2,size2,pos,regs,stop)3764 re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
3765 struct re_pattern_buffer *bufp;
3766 const char *string1, *string2;
3767 int size1, size2;
3768 int pos;
3769 struct re_registers *regs;
3770 int stop;
3771 {
3772 /* General temporaries. */
3773 int mcnt;
3774 unsigned char *p1;
3775
3776 /* Just past the end of the corresponding string. */
3777 const char *end1, *end2;
3778
3779 /* Pointers into string1 and string2, just past the last characters in
3780 each to consider matching. */
3781 const char *end_match_1, *end_match_2;
3782
3783 /* Where we are in the data, and the end of the current string. */
3784 const char *d, *dend;
3785
3786 /* Where we are in the pattern, and the end of the pattern. */
3787 unsigned char *p = bufp->buffer;
3788 register unsigned char *pend = p + bufp->used;
3789
3790 /* Mark the opcode just after a start_memory, so we can test for an
3791 empty subpattern when we get to the stop_memory. */
3792 unsigned char *just_past_start_mem = 0;
3793
3794 /* We use this to map every character in the string. */
3795 RE_TRANSLATE_TYPE translate = bufp->translate;
3796
3797 /* Failure point stack. Each place that can handle a failure further
3798 down the line pushes a failure point on this stack. It consists of
3799 restart, regend, and reg_info for all registers corresponding to
3800 the subexpressions we're currently inside, plus the number of such
3801 registers, and, finally, two char *'s. The first char * is where
3802 to resume scanning the pattern; the second one is where to resume
3803 scanning the strings. If the latter is zero, the failure point is
3804 a ``dummy''; if a failure happens and the failure point is a dummy,
3805 it gets discarded and the next next one is tried. */
3806 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3807 fail_stack_type fail_stack;
3808 #endif
3809 #ifdef DEBUG
3810 static unsigned failure_id = 0;
3811 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3812 #endif
3813
3814 #ifdef REL_ALLOC
3815 /* This holds the pointer to the failure stack, when
3816 it is allocated relocatably. */
3817 fail_stack_elt_t *failure_stack_ptr;
3818 #endif
3819
3820 /* We fill all the registers internally, independent of what we
3821 return, for use in backreferences. The number here includes
3822 an element for register zero. */
3823 size_t num_regs = bufp->re_nsub + 1;
3824
3825 /* The currently active registers. */
3826 active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3827 active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3828
3829 /* Information on the contents of registers. These are pointers into
3830 the input strings; they record just what was matched (on this
3831 attempt) by a subexpression part of the pattern, that is, the
3832 regnum-th regstart pointer points to where in the pattern we began
3833 matching and the regnum-th regend points to right after where we
3834 stopped matching the regnum-th subexpression. (The zeroth register
3835 keeps track of what the whole pattern matches.) */
3836 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3837 const char **regstart, **regend;
3838 #endif
3839
3840 /* If a group that's operated upon by a repetition operator fails to
3841 match anything, then the register for its start will need to be
3842 restored because it will have been set to wherever in the string we
3843 are when we last see its open-group operator. Similarly for a
3844 register's end. */
3845 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3846 const char **old_regstart, **old_regend;
3847 #endif
3848
3849 /* The is_active field of reg_info helps us keep track of which (possibly
3850 nested) subexpressions we are currently in. The matched_something
3851 field of reg_info[reg_num] helps us tell whether or not we have
3852 matched any of the pattern so far this time through the reg_num-th
3853 subexpression. These two fields get reset each time through any
3854 loop their register is in. */
3855 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3856 register_info_type *reg_info;
3857 #endif
3858
3859 /* The following record the register info as found in the above
3860 variables when we find a match better than any we've seen before.
3861 This happens as we backtrack through the failure points, which in
3862 turn happens only if we have not yet matched the entire string. */
3863 unsigned best_regs_set = false;
3864 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3865 const char **best_regstart, **best_regend;
3866 #endif
3867
3868 /* Logically, this is `best_regend[0]'. But we don't want to have to
3869 allocate space for that if we're not allocating space for anything
3870 else (see below). Also, we never need info about register 0 for
3871 any of the other register vectors, and it seems rather a kludge to
3872 treat `best_regend' differently than the rest. So we keep track of
3873 the end of the best match so far in a separate variable. We
3874 initialize this to NULL so that when we backtrack the first time
3875 and need to test it, it's not garbage. */
3876 const char *match_end = NULL;
3877
3878 /* This helps SET_REGS_MATCHED avoid doing redundant work. */
3879 int set_regs_matched_done = 0;
3880
3881 /* Used when we pop values we don't care about. */
3882 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3883 const char **reg_dummy;
3884 register_info_type *reg_info_dummy;
3885 #endif
3886
3887 #ifdef DEBUG
3888 /* Counts the total number of registers pushed. */
3889 unsigned num_regs_pushed = 0;
3890 #endif
3891
3892 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3893
3894 INIT_FAIL_STACK ();
3895
3896 #ifdef MATCH_MAY_ALLOCATE
3897 /* Do not bother to initialize all the register variables if there are
3898 no groups in the pattern, as it takes a fair amount of time. If
3899 there are groups, we include space for register 0 (the whole
3900 pattern), even though we never use it, since it simplifies the
3901 array indexing. We should fix this. */
3902 if (bufp->re_nsub)
3903 {
3904 regstart = REGEX_TALLOC (num_regs, const char *);
3905 regend = REGEX_TALLOC (num_regs, const char *);
3906 old_regstart = REGEX_TALLOC (num_regs, const char *);
3907 old_regend = REGEX_TALLOC (num_regs, const char *);
3908 best_regstart = REGEX_TALLOC (num_regs, const char *);
3909 best_regend = REGEX_TALLOC (num_regs, const char *);
3910 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3911 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3912 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3913
3914 if (!(regstart && regend && old_regstart && old_regend && reg_info
3915 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3916 {
3917 FREE_VARIABLES ();
3918 return -2;
3919 }
3920 }
3921 else
3922 {
3923 /* We must initialize all our variables to NULL, so that
3924 `FREE_VARIABLES' doesn't try to free them. */
3925 regstart = regend = old_regstart = old_regend = best_regstart
3926 = best_regend = reg_dummy = NULL;
3927 reg_info = reg_info_dummy = (register_info_type *) NULL;
3928 }
3929 #endif /* MATCH_MAY_ALLOCATE */
3930
3931 /* The starting position is bogus. */
3932 if (pos < 0 || pos > size1 + size2)
3933 {
3934 FREE_VARIABLES ();
3935 return -1;
3936 }
3937
3938 /* Initialize subexpression text positions to -1 to mark ones that no
3939 start_memory/stop_memory has been seen for. Also initialize the
3940 register information struct. */
3941 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
3942 {
3943 regstart[mcnt] = regend[mcnt]
3944 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3945
3946 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3947 IS_ACTIVE (reg_info[mcnt]) = 0;
3948 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3949 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3950 }
3951
3952 /* We move `string1' into `string2' if the latter's empty -- but not if
3953 `string1' is null. */
3954 if (size2 == 0 && string1 != NULL)
3955 {
3956 string2 = string1;
3957 size2 = size1;
3958 string1 = 0;
3959 size1 = 0;
3960 }
3961 end1 = string1 + size1;
3962 end2 = string2 + size2;
3963
3964 /* Compute where to stop matching, within the two strings. */
3965 if (stop <= size1)
3966 {
3967 end_match_1 = string1 + stop;
3968 end_match_2 = string2;
3969 }
3970 else
3971 {
3972 end_match_1 = end1;
3973 end_match_2 = string2 + stop - size1;
3974 }
3975
3976 /* `p' scans through the pattern as `d' scans through the data.
3977 `dend' is the end of the input string that `d' points within. `d'
3978 is advanced into the following input string whenever necessary, but
3979 this happens before fetching; therefore, at the beginning of the
3980 loop, `d' can be pointing at the end of a string, but it cannot
3981 equal `string2'. */
3982 if (size1 > 0 && pos <= size1)
3983 {
3984 d = string1 + pos;
3985 dend = end_match_1;
3986 }
3987 else
3988 {
3989 d = string2 + pos - size1;
3990 dend = end_match_2;
3991 }
3992
3993 DEBUG_PRINT1 ("The compiled pattern is:\n");
3994 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3995 DEBUG_PRINT1 ("The string to match is: `");
3996 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3997 DEBUG_PRINT1 ("'\n");
3998
3999 /* This loops over pattern commands. It exits by returning from the
4000 function if the match is complete, or it drops through if the match
4001 fails at this starting point in the input data. */
4002 for (;;)
4003 {
4004 #ifdef _LIBC
4005 DEBUG_PRINT2 ("\n%p: ", p);
4006 #else
4007 DEBUG_PRINT2 ("\n0x%x: ", p);
4008 #endif
4009
4010 if (p == pend)
4011 { /* End of pattern means we might have succeeded. */
4012 DEBUG_PRINT1 ("end of pattern ... ");
4013
4014 /* If we haven't matched the entire string, and we want the
4015 longest match, try backtracking. */
4016 if (d != end_match_2)
4017 {
4018 /* 1 if this match ends in the same string (string1 or string2)
4019 as the best previous match. */
4020 boolean same_str_p;
4021 /* 1 if this match is the best seen so far. */
4022 boolean best_match_p;
4023
4024 same_str_p = (FIRST_STRING_P (match_end)
4025 == MATCHING_IN_FIRST_STRING);
4026
4027 /* AIX compiler got confused when this was combined
4028 with the previous declaration. */
4029 if (same_str_p)
4030 best_match_p = d > match_end;
4031 else
4032 best_match_p = !MATCHING_IN_FIRST_STRING;
4033
4034 DEBUG_PRINT1 ("backtracking.\n");
4035
4036 if (!FAIL_STACK_EMPTY ())
4037 { /* More failure points to try. */
4038
4039 /* If exceeds best match so far, save it. */
4040 if (!best_regs_set || best_match_p)
4041 {
4042 best_regs_set = true;
4043 match_end = d;
4044
4045 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
4046
4047 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
4048 {
4049 best_regstart[mcnt] = regstart[mcnt];
4050 best_regend[mcnt] = regend[mcnt];
4051 }
4052 }
4053 goto fail;
4054 }
4055
4056 /* If no failure points, don't restore garbage. And if
4057 last match is real best match, don't restore second
4058 best one. */
4059 else if (best_regs_set && !best_match_p)
4060 {
4061 restore_best_regs:
4062 /* Restore best match. It may happen that `dend ==
4063 end_match_1' while the restored d is in string2.
4064 For example, the pattern `x.*y.*z' against the
4065 strings `x-' and `y-z-', if the two strings are
4066 not consecutive in memory. */
4067 DEBUG_PRINT1 ("Restoring best registers.\n");
4068
4069 d = match_end;
4070 dend = ((d >= string1 && d <= end1)
4071 ? end_match_1 : end_match_2);
4072
4073 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
4074 {
4075 regstart[mcnt] = best_regstart[mcnt];
4076 regend[mcnt] = best_regend[mcnt];
4077 }
4078 }
4079 } /* d != end_match_2 */
4080
4081 succeed_label:
4082 DEBUG_PRINT1 ("Accepting match.\n");
4083
4084 /* If caller wants register contents data back, do it. */
4085 if (regs && !bufp->no_sub)
4086 {
4087 /* Have the register data arrays been allocated? */
4088 if (bufp->regs_allocated == REGS_UNALLOCATED)
4089 { /* No. So allocate them with malloc. We need one
4090 extra element beyond `num_regs' for the `-1' marker
4091 GNU code uses. */
4092 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
4093 regs->start = TALLOC (regs->num_regs, regoff_t);
4094 regs->end = TALLOC (regs->num_regs, regoff_t);
4095 if (regs->start == NULL || regs->end == NULL)
4096 {
4097 FREE_VARIABLES ();
4098 return -2;
4099 }
4100 bufp->regs_allocated = REGS_REALLOCATE;
4101 }
4102 else if (bufp->regs_allocated == REGS_REALLOCATE)
4103 { /* Yes. If we need more elements than were already
4104 allocated, reallocate them. If we need fewer, just
4105 leave it alone. */
4106 if (regs->num_regs < num_regs + 1)
4107 {
4108 regs->num_regs = num_regs + 1;
4109 RETALLOC (regs->start, regs->num_regs, regoff_t);
4110 RETALLOC (regs->end, regs->num_regs, regoff_t);
4111 if (regs->start == NULL || regs->end == NULL)
4112 {
4113 FREE_VARIABLES ();
4114 return -2;
4115 }
4116 }
4117 }
4118 else
4119 {
4120 /* These braces fend off a "empty body in an else-statement"
4121 warning under GCC when assert expands to nothing. */
4122 assert (bufp->regs_allocated == REGS_FIXED);
4123 }
4124
4125 /* Convert the pointer data in `regstart' and `regend' to
4126 indices. Register zero has to be set differently,
4127 since we haven't kept track of any info for it. */
4128 if (regs->num_regs > 0)
4129 {
4130 regs->start[0] = pos;
4131 regs->end[0] = (MATCHING_IN_FIRST_STRING
4132 ? ((regoff_t) (d - string1))
4133 : ((regoff_t) (d - string2 + size1)));
4134 }
4135
4136 /* Go through the first `min (num_regs, regs->num_regs)'
4137 registers, since that is all we initialized. */
4138 for (mcnt = 1; (unsigned) mcnt < MIN (num_regs, regs->num_regs);
4139 mcnt++)
4140 {
4141 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
4142 regs->start[mcnt] = regs->end[mcnt] = -1;
4143 else
4144 {
4145 regs->start[mcnt]
4146 = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
4147 regs->end[mcnt]
4148 = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
4149 }
4150 }
4151
4152 /* If the regs structure we return has more elements than
4153 were in the pattern, set the extra elements to -1. If
4154 we (re)allocated the registers, this is the case,
4155 because we always allocate enough to have at least one
4156 -1 at the end. */
4157 for (mcnt = num_regs; (unsigned) mcnt < regs->num_regs; mcnt++)
4158 regs->start[mcnt] = regs->end[mcnt] = -1;
4159 } /* regs && !bufp->no_sub */
4160
4161 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
4162 nfailure_points_pushed, nfailure_points_popped,
4163 nfailure_points_pushed - nfailure_points_popped);
4164 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
4165
4166 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
4167 ? string1
4168 : string2 - size1);
4169
4170 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
4171
4172 FREE_VARIABLES ();
4173 return mcnt;
4174 }
4175
4176 /* Otherwise match next pattern command. */
4177 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
4178 {
4179 /* Ignore these. Used to ignore the n of succeed_n's which
4180 currently have n == 0. */
4181 case no_op:
4182 DEBUG_PRINT1 ("EXECUTING no_op.\n");
4183 break;
4184
4185 case succeed:
4186 DEBUG_PRINT1 ("EXECUTING succeed.\n");
4187 goto succeed_label;
4188
4189 /* Match the next n pattern characters exactly. The following
4190 byte in the pattern defines n, and the n bytes after that
4191 are the characters to match. */
4192 case exactn:
4193 mcnt = *p++;
4194 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
4195
4196 /* This is written out as an if-else so we don't waste time
4197 testing `translate' inside the loop. */
4198 if (translate)
4199 {
4200 do
4201 {
4202 PREFETCH ();
4203 if ((unsigned char) translate[(unsigned char) *d++]
4204 != (unsigned char) *p++)
4205 goto fail;
4206 }
4207 while (--mcnt);
4208 }
4209 else
4210 {
4211 do
4212 {
4213 PREFETCH ();
4214 if (*d++ != (char) *p++) goto fail;
4215 }
4216 while (--mcnt);
4217 }
4218 SET_REGS_MATCHED ();
4219 break;
4220
4221
4222 /* Match any character except possibly a newline or a null. */
4223 case anychar:
4224 DEBUG_PRINT1 ("EXECUTING anychar.\n");
4225
4226 PREFETCH ();
4227
4228 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
4229 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
4230 goto fail;
4231
4232 SET_REGS_MATCHED ();
4233 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
4234 d++;
4235 break;
4236
4237
4238 case charset:
4239 case charset_not:
4240 {
4241 register unsigned char c;
4242 boolean not = (re_opcode_t) *(p - 1) == charset_not;
4243
4244 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
4245
4246 PREFETCH ();
4247 c = TRANSLATE (*d); /* The character to match. */
4248
4249 /* Cast to `unsigned' instead of `unsigned char' in case the
4250 bit list is a full 32 bytes long. */
4251 if (c < (unsigned) (*p * BYTEWIDTH)
4252 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4253 not = !not;
4254
4255 p += 1 + *p;
4256
4257 if (!not) goto fail;
4258
4259 SET_REGS_MATCHED ();
4260 d++;
4261 break;
4262 }
4263
4264
4265 /* The beginning of a group is represented by start_memory.
4266 The arguments are the register number in the next byte, and the
4267 number of groups inner to this one in the next. The text
4268 matched within the group is recorded (in the internal
4269 registers data structure) under the register number. */
4270 case start_memory:
4271 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
4272
4273 /* Find out if this group can match the empty string. */
4274 p1 = p; /* To send to group_match_null_string_p. */
4275
4276 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
4277 REG_MATCH_NULL_STRING_P (reg_info[*p])
4278 = group_match_null_string_p (&p1, pend, reg_info);
4279
4280 /* Save the position in the string where we were the last time
4281 we were at this open-group operator in case the group is
4282 operated upon by a repetition operator, e.g., with `(a*)*b'
4283 against `ab'; then we want to ignore where we are now in
4284 the string in case this attempt to match fails. */
4285 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4286 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
4287 : regstart[*p];
4288 DEBUG_PRINT2 (" old_regstart: %d\n",
4289 POINTER_TO_OFFSET (old_regstart[*p]));
4290
4291 regstart[*p] = d;
4292 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
4293
4294 IS_ACTIVE (reg_info[*p]) = 1;
4295 MATCHED_SOMETHING (reg_info[*p]) = 0;
4296
4297 /* Clear this whenever we change the register activity status. */
4298 set_regs_matched_done = 0;
4299
4300 /* This is the new highest active register. */
4301 highest_active_reg = *p;
4302
4303 /* If nothing was active before, this is the new lowest active
4304 register. */
4305 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4306 lowest_active_reg = *p;
4307
4308 /* Move past the register number and inner group count. */
4309 p += 2;
4310 just_past_start_mem = p;
4311
4312 break;
4313
4314
4315 /* The stop_memory opcode represents the end of a group. Its
4316 arguments are the same as start_memory's: the register
4317 number, and the number of inner groups. */
4318 case stop_memory:
4319 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
4320
4321 /* We need to save the string position the last time we were at
4322 this close-group operator in case the group is operated
4323 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
4324 against `aba'; then we want to ignore where we are now in
4325 the string in case this attempt to match fails. */
4326 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4327 ? REG_UNSET (regend[*p]) ? d : regend[*p]
4328 : regend[*p];
4329 DEBUG_PRINT2 (" old_regend: %d\n",
4330 POINTER_TO_OFFSET (old_regend[*p]));
4331
4332 regend[*p] = d;
4333 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
4334
4335 /* This register isn't active anymore. */
4336 IS_ACTIVE (reg_info[*p]) = 0;
4337
4338 /* Clear this whenever we change the register activity status. */
4339 set_regs_matched_done = 0;
4340
4341 /* If this was the only register active, nothing is active
4342 anymore. */
4343 if (lowest_active_reg == highest_active_reg)
4344 {
4345 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4346 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4347 }
4348 else
4349 { /* We must scan for the new highest active register, since
4350 it isn't necessarily one less than now: consider
4351 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
4352 new highest active register is 1. */
4353 unsigned char r = *p - 1;
4354 while (r > 0 && !IS_ACTIVE (reg_info[r]))
4355 r--;
4356
4357 /* If we end up at register zero, that means that we saved
4358 the registers as the result of an `on_failure_jump', not
4359 a `start_memory', and we jumped to past the innermost
4360 `stop_memory'. For example, in ((.)*) we save
4361 registers 1 and 2 as a result of the *, but when we pop
4362 back to the second ), we are at the stop_memory 1.
4363 Thus, nothing is active. */
4364 if (r == 0)
4365 {
4366 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4367 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4368 }
4369 else
4370 highest_active_reg = r;
4371 }
4372
4373 /* If just failed to match something this time around with a
4374 group that's operated on by a repetition operator, try to
4375 force exit from the ``loop'', and restore the register
4376 information for this group that we had before trying this
4377 last match. */
4378 if ((!MATCHED_SOMETHING (reg_info[*p])
4379 || just_past_start_mem == p - 1)
4380 && (p + 2) < pend)
4381 {
4382 boolean is_a_jump_n = false;
4383
4384 p1 = p + 2;
4385 mcnt = 0;
4386 switch ((re_opcode_t) *p1++)
4387 {
4388 case jump_n:
4389 is_a_jump_n = true;
4390 case pop_failure_jump:
4391 case maybe_pop_jump:
4392 case jump:
4393 case dummy_failure_jump:
4394 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4395 if (is_a_jump_n)
4396 p1 += 2;
4397 break;
4398
4399 default:
4400 /* do nothing */ ;
4401 }
4402 p1 += mcnt;
4403
4404 /* If the next operation is a jump backwards in the pattern
4405 to an on_failure_jump right before the start_memory
4406 corresponding to this stop_memory, exit from the loop
4407 by forcing a failure after pushing on the stack the
4408 on_failure_jump's jump in the pattern, and d. */
4409 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
4410 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
4411 {
4412 /* If this group ever matched anything, then restore
4413 what its registers were before trying this last
4414 failed match, e.g., with `(a*)*b' against `ab' for
4415 regstart[1], and, e.g., with `((a*)*(b*)*)*'
4416 against `aba' for regend[3].
4417
4418 Also restore the registers for inner groups for,
4419 e.g., `((a*)(b*))*' against `aba' (register 3 would
4420 otherwise get trashed). */
4421
4422 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
4423 {
4424 unsigned r;
4425
4426 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
4427
4428 /* Restore this and inner groups' (if any) registers. */
4429 for (r = *p; r < (unsigned) *p + (unsigned) *(p + 1);
4430 r++)
4431 {
4432 regstart[r] = old_regstart[r];
4433
4434 /* xx why this test? */
4435 if (old_regend[r] >= regstart[r])
4436 regend[r] = old_regend[r];
4437 }
4438 }
4439 p1++;
4440 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4441 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
4442
4443 goto fail;
4444 }
4445 }
4446
4447 /* Move past the register number and the inner group count. */
4448 p += 2;
4449 break;
4450
4451
4452 /* \<digit> has been turned into a `duplicate' command which is
4453 followed by the numeric value of <digit> as the register number. */
4454 case duplicate:
4455 {
4456 register const char *d2, *dend2;
4457 int regno = *p++; /* Get which register to match against. */
4458 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
4459
4460 /* Can't back reference a group which we've never matched. */
4461 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
4462 goto fail;
4463
4464 /* Where in input to try to start matching. */
4465 d2 = regstart[regno];
4466
4467 /* Where to stop matching; if both the place to start and
4468 the place to stop matching are in the same string, then
4469 set to the place to stop, otherwise, for now have to use
4470 the end of the first string. */
4471
4472 dend2 = ((FIRST_STRING_P (regstart[regno])
4473 == FIRST_STRING_P (regend[regno]))
4474 ? regend[regno] : end_match_1);
4475 for (;;)
4476 {
4477 /* If necessary, advance to next segment in register
4478 contents. */
4479 while (d2 == dend2)
4480 {
4481 if (dend2 == end_match_2) break;
4482 if (dend2 == regend[regno]) break;
4483
4484 /* End of string1 => advance to string2. */
4485 d2 = string2;
4486 dend2 = regend[regno];
4487 }
4488 /* At end of register contents => success */
4489 if (d2 == dend2) break;
4490
4491 /* If necessary, advance to next segment in data. */
4492 PREFETCH ();
4493
4494 /* How many characters left in this segment to match. */
4495 mcnt = dend - d;
4496
4497 /* Want how many consecutive characters we can match in
4498 one shot, so, if necessary, adjust the count. */
4499 if (mcnt > dend2 - d2)
4500 mcnt = dend2 - d2;
4501
4502 /* Compare that many; failure if mismatch, else move
4503 past them. */
4504 if (translate
4505 ? bcmp_translate (d, d2, mcnt, translate)
4506 : bcmp (d, d2, mcnt))
4507 goto fail;
4508 d += mcnt, d2 += mcnt;
4509
4510 /* Do this because we've match some characters. */
4511 SET_REGS_MATCHED ();
4512 }
4513 }
4514 break;
4515
4516
4517 /* begline matches the empty string at the beginning of the string
4518 (unless `not_bol' is set in `bufp'), and, if
4519 `newline_anchor' is set, after newlines. */
4520 case begline:
4521 DEBUG_PRINT1 ("EXECUTING begline.\n");
4522
4523 if (AT_STRINGS_BEG (d))
4524 {
4525 if (!bufp->not_bol) break;
4526 }
4527 else if (d[-1] == '\n' && bufp->newline_anchor)
4528 {
4529 break;
4530 }
4531 /* In all other cases, we fail. */
4532 goto fail;
4533
4534
4535 /* endline is the dual of begline. */
4536 case endline:
4537 DEBUG_PRINT1 ("EXECUTING endline.\n");
4538
4539 if (AT_STRINGS_END (d))
4540 {
4541 if (!bufp->not_eol) break;
4542 }
4543
4544 /* We have to ``prefetch'' the next character. */
4545 else if ((d == end1 ? *string2 : *d) == '\n'
4546 && bufp->newline_anchor)
4547 {
4548 break;
4549 }
4550 goto fail;
4551
4552
4553 /* Match at the very beginning of the data. */
4554 case begbuf:
4555 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4556 if (AT_STRINGS_BEG (d))
4557 break;
4558 goto fail;
4559
4560
4561 /* Match at the very end of the data. */
4562 case endbuf:
4563 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4564 if (AT_STRINGS_END (d))
4565 break;
4566 goto fail;
4567
4568
4569 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
4570 pushes NULL as the value for the string on the stack. Then
4571 `pop_failure_point' will keep the current value for the
4572 string, instead of restoring it. To see why, consider
4573 matching `foo\nbar' against `.*\n'. The .* matches the foo;
4574 then the . fails against the \n. But the next thing we want
4575 to do is match the \n against the \n; if we restored the
4576 string value, we would be back at the foo.
4577
4578 Because this is used only in specific cases, we don't need to
4579 check all the things that `on_failure_jump' does, to make
4580 sure the right things get saved on the stack. Hence we don't
4581 share its code. The only reason to push anything on the
4582 stack at all is that otherwise we would have to change
4583 `anychar's code to do something besides goto fail in this
4584 case; that seems worse than this. */
4585 case on_failure_keep_string_jump:
4586 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4587
4588 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4589 #ifdef _LIBC
4590 DEBUG_PRINT3 (" %d (to %p):\n", mcnt, p + mcnt);
4591 #else
4592 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4593 #endif
4594
4595 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4596 break;
4597
4598
4599 /* Uses of on_failure_jump:
4600
4601 Each alternative starts with an on_failure_jump that points
4602 to the beginning of the next alternative. Each alternative
4603 except the last ends with a jump that in effect jumps past
4604 the rest of the alternatives. (They really jump to the
4605 ending jump of the following alternative, because tensioning
4606 these jumps is a hassle.)
4607
4608 Repeats start with an on_failure_jump that points past both
4609 the repetition text and either the following jump or
4610 pop_failure_jump back to this on_failure_jump. */
4611 case on_failure_jump:
4612 on_failure:
4613 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4614
4615 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4616 #ifdef _LIBC
4617 DEBUG_PRINT3 (" %d (to %p)", mcnt, p + mcnt);
4618 #else
4619 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4620 #endif
4621
4622 /* If this on_failure_jump comes right before a group (i.e.,
4623 the original * applied to a group), save the information
4624 for that group and all inner ones, so that if we fail back
4625 to this point, the group's information will be correct.
4626 For example, in \(a*\)*\1, we need the preceding group,
4627 and in \(zz\(a*\)b*\)\2, we need the inner group. */
4628
4629 /* We can't use `p' to check ahead because we push
4630 a failure point to `p + mcnt' after we do this. */
4631 p1 = p;
4632
4633 /* We need to skip no_op's before we look for the
4634 start_memory in case this on_failure_jump is happening as
4635 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
4636 against aba. */
4637 while (p1 < pend && (re_opcode_t) *p1 == no_op)
4638 p1++;
4639
4640 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
4641 {
4642 /* We have a new highest active register now. This will
4643 get reset at the start_memory we are about to get to,
4644 but we will have saved all the registers relevant to
4645 this repetition op, as described above. */
4646 highest_active_reg = *(p1 + 1) + *(p1 + 2);
4647 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4648 lowest_active_reg = *(p1 + 1);
4649 }
4650
4651 DEBUG_PRINT1 (":\n");
4652 PUSH_FAILURE_POINT (p + mcnt, d, -2);
4653 break;
4654
4655
4656 /* A smart repeat ends with `maybe_pop_jump'.
4657 We change it to either `pop_failure_jump' or `jump'. */
4658 case maybe_pop_jump:
4659 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4660 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4661 {
4662 register unsigned char *p2 = p;
4663
4664 /* Compare the beginning of the repeat with what in the
4665 pattern follows its end. If we can establish that there
4666 is nothing that they would both match, i.e., that we
4667 would have to backtrack because of (as in, e.g., `a*a')
4668 then we can change to pop_failure_jump, because we'll
4669 never have to backtrack.
4670
4671 This is not true in the case of alternatives: in
4672 `(a|ab)*' we do need to backtrack to the `ab' alternative
4673 (e.g., if the string was `ab'). But instead of trying to
4674 detect that here, the alternative has put on a dummy
4675 failure point which is what we will end up popping. */
4676
4677 /* Skip over open/close-group commands.
4678 If what follows this loop is a ...+ construct,
4679 look at what begins its body, since we will have to
4680 match at least one of that. */
4681 while (1)
4682 {
4683 if (p2 + 2 < pend
4684 && ((re_opcode_t) *p2 == stop_memory
4685 || (re_opcode_t) *p2 == start_memory))
4686 p2 += 3;
4687 else if (p2 + 6 < pend
4688 && (re_opcode_t) *p2 == dummy_failure_jump)
4689 p2 += 6;
4690 else
4691 break;
4692 }
4693
4694 p1 = p + mcnt;
4695 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4696 to the `maybe_finalize_jump' of this case. Examine what
4697 follows. */
4698
4699 /* If we're at the end of the pattern, we can change. */
4700 if (p2 == pend)
4701 {
4702 /* Consider what happens when matching ":\(.*\)"
4703 against ":/". I don't really understand this code
4704 yet. */
4705 p[-3] = (unsigned char) pop_failure_jump;
4706 DEBUG_PRINT1
4707 (" End of pattern: change to `pop_failure_jump'.\n");
4708 }
4709
4710 else if ((re_opcode_t) *p2 == exactn
4711 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4712 {
4713 register unsigned char c
4714 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4715
4716 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4717 {
4718 p[-3] = (unsigned char) pop_failure_jump;
4719 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4720 c, p1[5]);
4721 }
4722
4723 else if ((re_opcode_t) p1[3] == charset
4724 || (re_opcode_t) p1[3] == charset_not)
4725 {
4726 int not = (re_opcode_t) p1[3] == charset_not;
4727
4728 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4729 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4730 not = !not;
4731
4732 /* `not' is equal to 1 if c would match, which means
4733 that we can't change to pop_failure_jump. */
4734 if (!not)
4735 {
4736 p[-3] = (unsigned char) pop_failure_jump;
4737 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4738 }
4739 }
4740 }
4741 else if ((re_opcode_t) *p2 == charset)
4742 {
4743 #ifdef DEBUG
4744 register unsigned char c
4745 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4746 #endif
4747
4748 #if 0
4749 if ((re_opcode_t) p1[3] == exactn
4750 && ! ((int) p2[1] * BYTEWIDTH > (int) p1[5]
4751 && (p2[2 + p1[5] / BYTEWIDTH]
4752 & (1 << (p1[5] % BYTEWIDTH)))))
4753 #else
4754 if ((re_opcode_t) p1[3] == exactn
4755 && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
4756 && (p2[2 + p1[4] / BYTEWIDTH]
4757 & (1 << (p1[4] % BYTEWIDTH)))))
4758 #endif
4759 {
4760 p[-3] = (unsigned char) pop_failure_jump;
4761 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4762 c, p1[5]);
4763 }
4764
4765 else if ((re_opcode_t) p1[3] == charset_not)
4766 {
4767 int idx;
4768 /* We win if the charset_not inside the loop
4769 lists every character listed in the charset after. */
4770 for (idx = 0; idx < (int) p2[1]; idx++)
4771 if (! (p2[2 + idx] == 0
4772 || (idx < (int) p1[4]
4773 && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
4774 break;
4775
4776 if (idx == p2[1])
4777 {
4778 p[-3] = (unsigned char) pop_failure_jump;
4779 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4780 }
4781 }
4782 else if ((re_opcode_t) p1[3] == charset)
4783 {
4784 int idx;
4785 /* We win if the charset inside the loop
4786 has no overlap with the one after the loop. */
4787 for (idx = 0;
4788 idx < (int) p2[1] && idx < (int) p1[4];
4789 idx++)
4790 if ((p2[2 + idx] & p1[5 + idx]) != 0)
4791 break;
4792
4793 if (idx == p2[1] || idx == p1[4])
4794 {
4795 p[-3] = (unsigned char) pop_failure_jump;
4796 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4797 }
4798 }
4799 }
4800 }
4801 p -= 2; /* Point at relative address again. */
4802 if ((re_opcode_t) p[-1] != pop_failure_jump)
4803 {
4804 p[-1] = (unsigned char) jump;
4805 DEBUG_PRINT1 (" Match => jump.\n");
4806 goto unconditional_jump;
4807 }
4808 /* Note fall through. */
4809
4810
4811 /* The end of a simple repeat has a pop_failure_jump back to
4812 its matching on_failure_jump, where the latter will push a
4813 failure point. The pop_failure_jump takes off failure
4814 points put on by this pop_failure_jump's matching
4815 on_failure_jump; we got through the pattern to here from the
4816 matching on_failure_jump, so didn't fail. */
4817 case pop_failure_jump:
4818 {
4819 /* We need to pass separate storage for the lowest and
4820 highest registers, even though we don't care about the
4821 actual values. Otherwise, we will restore only one
4822 register from the stack, since lowest will == highest in
4823 `pop_failure_point'. */
4824 active_reg_t dummy_low_reg, dummy_high_reg;
4825 unsigned char *pdummy;
4826 const char *sdummy;
4827
4828 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4829 POP_FAILURE_POINT (sdummy, pdummy,
4830 dummy_low_reg, dummy_high_reg,
4831 reg_dummy, reg_dummy, reg_info_dummy);
4832 }
4833 /* Note fall through. */
4834
4835 unconditional_jump:
4836 #ifdef _LIBC
4837 DEBUG_PRINT2 ("\n%p: ", p);
4838 #else
4839 DEBUG_PRINT2 ("\n0x%x: ", p);
4840 #endif
4841 /* Note fall through. */
4842
4843 /* Unconditionally jump (without popping any failure points). */
4844 case jump:
4845 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4846 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4847 p += mcnt; /* Do the jump. */
4848 #ifdef _LIBC
4849 DEBUG_PRINT2 ("(to %p).\n", p);
4850 #else
4851 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4852 #endif
4853 break;
4854
4855
4856 /* We need this opcode so we can detect where alternatives end
4857 in `group_match_null_string_p' et al. */
4858 case jump_past_alt:
4859 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4860 goto unconditional_jump;
4861
4862
4863 /* Normally, the on_failure_jump pushes a failure point, which
4864 then gets popped at pop_failure_jump. We will end up at
4865 pop_failure_jump, also, and with a pattern of, say, `a+', we
4866 are skipping over the on_failure_jump, so we have to push
4867 something meaningless for pop_failure_jump to pop. */
4868 case dummy_failure_jump:
4869 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4870 /* It doesn't matter what we push for the string here. What
4871 the code at `fail' tests is the value for the pattern. */
4872 PUSH_FAILURE_POINT (0, 0, -2);
4873 goto unconditional_jump;
4874
4875
4876 /* At the end of an alternative, we need to push a dummy failure
4877 point in case we are followed by a `pop_failure_jump', because
4878 we don't want the failure point for the alternative to be
4879 popped. For example, matching `(a|ab)*' against `aab'
4880 requires that we match the `ab' alternative. */
4881 case push_dummy_failure:
4882 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4883 /* See comments just above at `dummy_failure_jump' about the
4884 two zeroes. */
4885 PUSH_FAILURE_POINT (0, 0, -2);
4886 break;
4887
4888 /* Have to succeed matching what follows at least n times.
4889 After that, handle like `on_failure_jump'. */
4890 case succeed_n:
4891 EXTRACT_NUMBER (mcnt, p + 2);
4892 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4893
4894 assert (mcnt >= 0);
4895 /* Originally, this is how many times we HAVE to succeed. */
4896 if (mcnt > 0)
4897 {
4898 mcnt--;
4899 p += 2;
4900 STORE_NUMBER_AND_INCR (p, mcnt);
4901 #ifdef _LIBC
4902 DEBUG_PRINT3 (" Setting %p to %d.\n", p - 2, mcnt);
4903 #else
4904 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p - 2, mcnt);
4905 #endif
4906 }
4907 else if (mcnt == 0)
4908 {
4909 #ifdef _LIBC
4910 DEBUG_PRINT2 (" Setting two bytes from %p to no_op.\n", p+2);
4911 #else
4912 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4913 #endif
4914 p[2] = (unsigned char) no_op;
4915 p[3] = (unsigned char) no_op;
4916 goto on_failure;
4917 }
4918 break;
4919
4920 case jump_n:
4921 EXTRACT_NUMBER (mcnt, p + 2);
4922 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4923
4924 /* Originally, this is how many times we CAN jump. */
4925 if (mcnt)
4926 {
4927 mcnt--;
4928 STORE_NUMBER (p + 2, mcnt);
4929 #ifdef _LIBC
4930 DEBUG_PRINT3 (" Setting %p to %d.\n", p + 2, mcnt);
4931 #else
4932 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p + 2, mcnt);
4933 #endif
4934 goto unconditional_jump;
4935 }
4936 /* If don't have to jump any more, skip over the rest of command. */
4937 else
4938 p += 4;
4939 break;
4940
4941 case set_number_at:
4942 {
4943 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4944
4945 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4946 p1 = p + mcnt;
4947 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4948 #ifdef _LIBC
4949 DEBUG_PRINT3 (" Setting %p to %d.\n", p1, mcnt);
4950 #else
4951 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4952 #endif
4953 STORE_NUMBER (p1, mcnt);
4954 break;
4955 }
4956
4957 #if 0
4958 /* The DEC Alpha C compiler 3.x generates incorrect code for the
4959 test WORDCHAR_P (d - 1) != WORDCHAR_P (d) in the expansion of
4960 AT_WORD_BOUNDARY, so this code is disabled. Expanding the
4961 macro and introducing temporary variables works around the bug. */
4962
4963 case wordbound:
4964 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4965 if (AT_WORD_BOUNDARY (d))
4966 break;
4967 goto fail;
4968
4969 case notwordbound:
4970 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4971 if (AT_WORD_BOUNDARY (d))
4972 goto fail;
4973 break;
4974 #else
4975 case wordbound:
4976 {
4977 boolean prevchar, thischar;
4978
4979 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4980 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4981 break;
4982
4983 prevchar = WORDCHAR_P (d - 1);
4984 thischar = WORDCHAR_P (d);
4985 if (prevchar != thischar)
4986 break;
4987 goto fail;
4988 }
4989
4990 case notwordbound:
4991 {
4992 boolean prevchar, thischar;
4993
4994 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4995 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4996 goto fail;
4997
4998 prevchar = WORDCHAR_P (d - 1);
4999 thischar = WORDCHAR_P (d);
5000 if (prevchar != thischar)
5001 goto fail;
5002 break;
5003 }
5004 #endif
5005
5006 case wordbeg:
5007 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
5008 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
5009 break;
5010 goto fail;
5011
5012 case wordend:
5013 DEBUG_PRINT1 ("EXECUTING wordend.\n");
5014 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
5015 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
5016 break;
5017 goto fail;
5018
5019 #ifdef emacs
5020 case before_dot:
5021 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
5022 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
5023 goto fail;
5024 break;
5025
5026 case at_dot:
5027 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
5028 if (PTR_CHAR_POS ((unsigned char *) d) != point)
5029 goto fail;
5030 break;
5031
5032 case after_dot:
5033 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
5034 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
5035 goto fail;
5036 break;
5037
5038 case syntaxspec:
5039 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
5040 mcnt = *p++;
5041 goto matchsyntax;
5042
5043 case wordchar:
5044 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
5045 mcnt = (int) Sword;
5046 matchsyntax:
5047 PREFETCH ();
5048 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
5049 d++;
5050 if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
5051 goto fail;
5052 SET_REGS_MATCHED ();
5053 break;
5054
5055 case notsyntaxspec:
5056 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
5057 mcnt = *p++;
5058 goto matchnotsyntax;
5059
5060 case notwordchar:
5061 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
5062 mcnt = (int) Sword;
5063 matchnotsyntax:
5064 PREFETCH ();
5065 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
5066 d++;
5067 if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
5068 goto fail;
5069 SET_REGS_MATCHED ();
5070 break;
5071
5072 #else /* not emacs */
5073 case wordchar:
5074 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
5075 PREFETCH ();
5076 if (!WORDCHAR_P (d))
5077 goto fail;
5078 SET_REGS_MATCHED ();
5079 d++;
5080 break;
5081
5082 case notwordchar:
5083 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
5084 PREFETCH ();
5085 if (WORDCHAR_P (d))
5086 goto fail;
5087 SET_REGS_MATCHED ();
5088 d++;
5089 break;
5090 #endif /* not emacs */
5091
5092 default:
5093 call_abort ();
5094 }
5095 continue; /* Successfully executed one pattern command; keep going. */
5096
5097
5098 /* We goto here if a matching operation fails. */
5099 fail:
5100 if (!FAIL_STACK_EMPTY ())
5101 { /* A restart point is known. Restore to that state. */
5102 DEBUG_PRINT1 ("\nFAIL:\n");
5103 POP_FAILURE_POINT (d, p,
5104 lowest_active_reg, highest_active_reg,
5105 regstart, regend, reg_info);
5106
5107 /* If this failure point is a dummy, try the next one. */
5108 if (!p)
5109 goto fail;
5110
5111 /* If we failed to the end of the pattern, don't examine *p. */
5112 assert (p <= pend);
5113 if (p < pend)
5114 {
5115 boolean is_a_jump_n = false;
5116
5117 /* If failed to a backwards jump that's part of a repetition
5118 loop, need to pop this failure point and use the next one. */
5119 switch ((re_opcode_t) *p)
5120 {
5121 case jump_n:
5122 is_a_jump_n = true;
5123 case maybe_pop_jump:
5124 case pop_failure_jump:
5125 case jump:
5126 p1 = p + 1;
5127 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5128 p1 += mcnt;
5129
5130 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
5131 || (!is_a_jump_n
5132 && (re_opcode_t) *p1 == on_failure_jump))
5133 goto fail;
5134 break;
5135 default:
5136 /* do nothing */ ;
5137 }
5138 }
5139
5140 if (d >= string1 && d <= end1)
5141 dend = end_match_1;
5142 }
5143 else
5144 break; /* Matching at this starting point really fails. */
5145 } /* for (;;) */
5146
5147 if (best_regs_set)
5148 goto restore_best_regs;
5149
5150 FREE_VARIABLES ();
5151
5152 return -1; /* Failure to match. */
5153 } /* re_match_2 */
5154
5155 /* Subroutine definitions for re_match_2. */
5156
5157
5158 /* We are passed P pointing to a register number after a start_memory.
5159
5160 Return true if the pattern up to the corresponding stop_memory can
5161 match the empty string, and false otherwise.
5162
5163 If we find the matching stop_memory, sets P to point to one past its number.
5164 Otherwise, sets P to an undefined byte less than or equal to END.
5165
5166 We don't handle duplicates properly (yet). */
5167
5168 static boolean
group_match_null_string_p(p,end,reg_info)5169 group_match_null_string_p (p, end, reg_info)
5170 unsigned char **p, *end;
5171 register_info_type *reg_info;
5172 {
5173 int mcnt;
5174 /* Point to after the args to the start_memory. */
5175 unsigned char *p1 = *p + 2;
5176
5177 while (p1 < end)
5178 {
5179 /* Skip over opcodes that can match nothing, and return true or
5180 false, as appropriate, when we get to one that can't, or to the
5181 matching stop_memory. */
5182
5183 switch ((re_opcode_t) *p1)
5184 {
5185 /* Could be either a loop or a series of alternatives. */
5186 case on_failure_jump:
5187 p1++;
5188 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5189
5190 /* If the next operation is not a jump backwards in the
5191 pattern. */
5192
5193 if (mcnt >= 0)
5194 {
5195 /* Go through the on_failure_jumps of the alternatives,
5196 seeing if any of the alternatives cannot match nothing.
5197 The last alternative starts with only a jump,
5198 whereas the rest start with on_failure_jump and end
5199 with a jump, e.g., here is the pattern for `a|b|c':
5200
5201 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
5202 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
5203 /exactn/1/c
5204
5205 So, we have to first go through the first (n-1)
5206 alternatives and then deal with the last one separately. */
5207
5208
5209 /* Deal with the first (n-1) alternatives, which start
5210 with an on_failure_jump (see above) that jumps to right
5211 past a jump_past_alt. */
5212
5213 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
5214 {
5215 /* `mcnt' holds how many bytes long the alternative
5216 is, including the ending `jump_past_alt' and
5217 its number. */
5218
5219 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
5220 reg_info))
5221 return false;
5222
5223 /* Move to right after this alternative, including the
5224 jump_past_alt. */
5225 p1 += mcnt;
5226
5227 /* Break if it's the beginning of an n-th alternative
5228 that doesn't begin with an on_failure_jump. */
5229 if ((re_opcode_t) *p1 != on_failure_jump)
5230 break;
5231
5232 /* Still have to check that it's not an n-th
5233 alternative that starts with an on_failure_jump. */
5234 p1++;
5235 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5236 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
5237 {
5238 /* Get to the beginning of the n-th alternative. */
5239 p1 -= 3;
5240 break;
5241 }
5242 }
5243
5244 /* Deal with the last alternative: go back and get number
5245 of the `jump_past_alt' just before it. `mcnt' contains
5246 the length of the alternative. */
5247 EXTRACT_NUMBER (mcnt, p1 - 2);
5248
5249 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
5250 return false;
5251
5252 p1 += mcnt; /* Get past the n-th alternative. */
5253 } /* if mcnt > 0 */
5254 break;
5255
5256
5257 case stop_memory:
5258 assert (p1[1] == **p);
5259 *p = p1 + 2;
5260 return true;
5261
5262
5263 default:
5264 if (!common_op_match_null_string_p (&p1, end, reg_info))
5265 return false;
5266 }
5267 } /* while p1 < end */
5268
5269 return false;
5270 } /* group_match_null_string_p */
5271
5272
5273 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
5274 It expects P to be the first byte of a single alternative and END one
5275 byte past the last. The alternative can contain groups. */
5276
5277 static boolean
alt_match_null_string_p(p,end,reg_info)5278 alt_match_null_string_p (p, end, reg_info)
5279 unsigned char *p, *end;
5280 register_info_type *reg_info;
5281 {
5282 int mcnt;
5283 unsigned char *p1 = p;
5284
5285 while (p1 < end)
5286 {
5287 /* Skip over opcodes that can match nothing, and break when we get
5288 to one that can't. */
5289
5290 switch ((re_opcode_t) *p1)
5291 {
5292 /* It's a loop. */
5293 case on_failure_jump:
5294 p1++;
5295 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5296 p1 += mcnt;
5297 break;
5298
5299 default:
5300 if (!common_op_match_null_string_p (&p1, end, reg_info))
5301 return false;
5302 }
5303 } /* while p1 < end */
5304
5305 return true;
5306 } /* alt_match_null_string_p */
5307
5308
5309 /* Deals with the ops common to group_match_null_string_p and
5310 alt_match_null_string_p.
5311
5312 Sets P to one after the op and its arguments, if any. */
5313
5314 static boolean
common_op_match_null_string_p(p,end,reg_info)5315 common_op_match_null_string_p (p, end, reg_info)
5316 unsigned char **p, *end;
5317 register_info_type *reg_info;
5318 {
5319 int mcnt;
5320 boolean ret;
5321 int reg_no;
5322 unsigned char *p1 = *p;
5323
5324 switch ((re_opcode_t) *p1++)
5325 {
5326 case no_op:
5327 case begline:
5328 case endline:
5329 case begbuf:
5330 case endbuf:
5331 case wordbeg:
5332 case wordend:
5333 case wordbound:
5334 case notwordbound:
5335 #ifdef emacs
5336 case before_dot:
5337 case at_dot:
5338 case after_dot:
5339 #endif
5340 break;
5341
5342 case start_memory:
5343 reg_no = *p1;
5344 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
5345 ret = group_match_null_string_p (&p1, end, reg_info);
5346
5347 /* Have to set this here in case we're checking a group which
5348 contains a group and a back reference to it. */
5349
5350 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
5351 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
5352
5353 if (!ret)
5354 return false;
5355 break;
5356
5357 /* If this is an optimized succeed_n for zero times, make the jump. */
5358 case jump:
5359 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5360 if (mcnt >= 0)
5361 p1 += mcnt;
5362 else
5363 return false;
5364 break;
5365
5366 case succeed_n:
5367 /* Get to the number of times to succeed. */
5368 p1 += 2;
5369 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5370
5371 if (mcnt == 0)
5372 {
5373 p1 -= 4;
5374 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5375 p1 += mcnt;
5376 }
5377 else
5378 return false;
5379 break;
5380
5381 case duplicate:
5382 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
5383 return false;
5384 break;
5385
5386 case set_number_at:
5387 p1 += 4;
5388
5389 default:
5390 /* All other opcodes mean we cannot match the empty string. */
5391 return false;
5392 }
5393
5394 *p = p1;
5395 return true;
5396 } /* common_op_match_null_string_p */
5397
5398
5399 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
5400 bytes; nonzero otherwise. */
5401
5402 static int
bcmp_translate(s1,s2,len,translate)5403 bcmp_translate (s1, s2, len, translate)
5404 const char *s1, *s2;
5405 register int len;
5406 RE_TRANSLATE_TYPE translate;
5407 {
5408 register const unsigned char *p1 = (const unsigned char *) s1;
5409 register const unsigned char *p2 = (const unsigned char *) s2;
5410 while (len)
5411 {
5412 if (translate[*p1++] != translate[*p2++]) return 1;
5413 len--;
5414 }
5415 return 0;
5416 }
5417
5418 /* Entry points for GNU code. */
5419
5420 /* re_compile_pattern is the GNU regular expression compiler: it
5421 compiles PATTERN (of length SIZE) and puts the result in BUFP.
5422 Returns 0 if the pattern was valid, otherwise an error string.
5423
5424 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
5425 are set in BUFP on entry.
5426
5427 We call regex_compile to do the actual compilation. */
5428
5429 const char *
re_compile_pattern(pattern,length,bufp)5430 re_compile_pattern (pattern, length, bufp)
5431 const char *pattern;
5432 size_t length;
5433 struct re_pattern_buffer *bufp;
5434 {
5435 reg_errcode_t ret;
5436
5437 /* GNU code is written to assume at least RE_NREGS registers will be set
5438 (and at least one extra will be -1). */
5439 bufp->regs_allocated = REGS_UNALLOCATED;
5440
5441 /* And GNU code determines whether or not to get register information
5442 by passing null for the REGS argument to re_match, etc., not by
5443 setting no_sub. */
5444 bufp->no_sub = 0;
5445
5446 /* Match anchors at newline. */
5447 bufp->newline_anchor = 1;
5448
5449 ret = regex_compile (pattern, length, re_syntax_options, bufp);
5450
5451 if (!ret)
5452 return NULL;
5453 return gettext (re_error_msgid[(int) ret]);
5454 }
5455
5456 /* Entry points compatible with 4.2 BSD regex library. We don't define
5457 them unless specifically requested. */
5458
5459 #if defined (_REGEX_RE_COMP) || defined (_LIBC)
5460
5461 /* BSD has one and only one pattern buffer. */
5462 static struct re_pattern_buffer re_comp_buf;
5463
5464 char *
5465 #ifdef _LIBC
5466 /* Make these definitions weak in libc, so POSIX programs can redefine
5467 these names if they don't use our functions, and still use
5468 regcomp/regexec below without link errors. */
5469 weak_function
5470 #endif
re_comp(s)5471 re_comp (s)
5472 const char *s;
5473 {
5474 reg_errcode_t ret;
5475
5476 if (!s)
5477 {
5478 if (!re_comp_buf.buffer)
5479 return gettext ("No previous regular expression");
5480 return 0;
5481 }
5482
5483 if (!re_comp_buf.buffer)
5484 {
5485 re_comp_buf.buffer = (unsigned char *) malloc (200);
5486 if (re_comp_buf.buffer == NULL)
5487 return gettext (re_error_msgid[(int) REG_ESPACE]);
5488 re_comp_buf.allocated = 200;
5489
5490 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
5491 if (re_comp_buf.fastmap == NULL)
5492 return gettext (re_error_msgid[(int) REG_ESPACE]);
5493 }
5494
5495 /* Since `re_exec' always passes NULL for the `regs' argument, we
5496 don't need to initialize the pattern buffer fields which affect it. */
5497
5498 /* Match anchors at newlines. */
5499 re_comp_buf.newline_anchor = 1;
5500
5501 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
5502
5503 if (!ret)
5504 return NULL;
5505
5506 /* Yes, we're discarding `const' here if !HAVE_LIBINTL. */
5507 return (char *) gettext (re_error_msgid[(int) ret]);
5508 }
5509
5510
5511 int
5512 #ifdef _LIBC
5513 weak_function
5514 #endif
re_exec(s)5515 re_exec (s)
5516 const char *s;
5517 {
5518 const int len = strlen (s);
5519 return
5520 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
5521 }
5522
5523 #endif /* _REGEX_RE_COMP */
5524
5525 /* POSIX.2 functions. Don't define these for Emacs. */
5526
5527 #ifndef emacs
5528
5529 /* regcomp takes a regular expression as a string and compiles it.
5530
5531 PREG is a regex_t *. We do not expect any fields to be initialized,
5532 since POSIX says we shouldn't. Thus, we set
5533
5534 `buffer' to the compiled pattern;
5535 `used' to the length of the compiled pattern;
5536 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
5537 REG_EXTENDED bit in CFLAGS is set; otherwise, to
5538 RE_SYNTAX_POSIX_BASIC;
5539 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
5540 `fastmap' and `fastmap_accurate' to zero;
5541 `re_nsub' to the number of subexpressions in PATTERN.
5542
5543 PATTERN is the address of the pattern string.
5544
5545 CFLAGS is a series of bits which affect compilation.
5546
5547 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
5548 use POSIX basic syntax.
5549
5550 If REG_NEWLINE is set, then . and [^...] don't match newline.
5551 Also, regexec will try a match beginning after every newline.
5552
5553 If REG_ICASE is set, then we considers upper- and lowercase
5554 versions of letters to be equivalent when matching.
5555
5556 If REG_NOSUB is set, then when PREG is passed to regexec, that
5557 routine will report only success or failure, and nothing about the
5558 registers.
5559
5560 It returns 0 if it succeeds, nonzero if it doesn't. (See rx.h for
5561 the return codes and their meanings.) */
5562
5563 int
regcomp(preg,pattern,cflags)5564 regcomp (preg, pattern, cflags)
5565 regex_t *preg;
5566 const char *pattern;
5567 int cflags;
5568 {
5569 reg_errcode_t ret;
5570 reg_syntax_t syntax
5571 = (cflags & REG_EXTENDED) ?
5572 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
5573
5574 /* regex_compile will allocate the space for the compiled pattern. */
5575 preg->buffer = 0;
5576 preg->allocated = 0;
5577 preg->used = 0;
5578
5579 /* Don't bother to use a fastmap when searching. This simplifies the
5580 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
5581 characters after newlines into the fastmap. This way, we just try
5582 every character. */
5583 preg->fastmap = 0;
5584
5585 if (cflags & REG_ICASE)
5586 {
5587 unsigned i;
5588
5589 preg->translate
5590 = (RE_TRANSLATE_TYPE) malloc (CHAR_SET_SIZE
5591 * sizeof (*(RE_TRANSLATE_TYPE)0));
5592 if (preg->translate == NULL)
5593 return (int) REG_ESPACE;
5594
5595 /* Map uppercase characters to corresponding lowercase ones. */
5596 for (i = 0; i < CHAR_SET_SIZE; i++)
5597 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
5598 }
5599 else
5600 preg->translate = NULL;
5601
5602 /* If REG_NEWLINE is set, newlines are treated differently. */
5603 if (cflags & REG_NEWLINE)
5604 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
5605 syntax &= ~RE_DOT_NEWLINE;
5606 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
5607 /* It also changes the matching behavior. */
5608 preg->newline_anchor = 1;
5609 }
5610 else
5611 preg->newline_anchor = 0;
5612
5613 preg->no_sub = !!(cflags & REG_NOSUB);
5614
5615 /* POSIX says a null character in the pattern terminates it, so we
5616 can use strlen here in compiling the pattern. */
5617 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
5618
5619 /* POSIX doesn't distinguish between an unmatched open-group and an
5620 unmatched close-group: both are REG_EPAREN. */
5621 if (ret == REG_ERPAREN) ret = REG_EPAREN;
5622
5623 return (int) ret;
5624 }
5625
5626
5627 /* regexec searches for a given pattern, specified by PREG, in the
5628 string STRING.
5629
5630 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
5631 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
5632 least NMATCH elements, and we set them to the offsets of the
5633 corresponding matched substrings.
5634
5635 EFLAGS specifies `execution flags' which affect matching: if
5636 REG_NOTBOL is set, then ^ does not match at the beginning of the
5637 string; if REG_NOTEOL is set, then $ does not match at the end.
5638
5639 We return 0 if we find a match and REG_NOMATCH if not. */
5640
5641 int
regexec(preg,string,nmatch,pmatch,eflags)5642 regexec (preg, string, nmatch, pmatch, eflags)
5643 const regex_t *preg;
5644 const char *string;
5645 size_t nmatch;
5646 regmatch_t pmatch[];
5647 int eflags;
5648 {
5649 int ret;
5650 struct re_registers regs;
5651 regex_t private_preg;
5652 int len = strlen (string);
5653 boolean want_reg_info = !preg->no_sub && nmatch > 0;
5654
5655 private_preg = *preg;
5656
5657 private_preg.not_bol = !!(eflags & REG_NOTBOL);
5658 private_preg.not_eol = !!(eflags & REG_NOTEOL);
5659
5660 /* The user has told us exactly how many registers to return
5661 information about, via `nmatch'. We have to pass that on to the
5662 matching routines. */
5663 private_preg.regs_allocated = REGS_FIXED;
5664
5665 if (want_reg_info)
5666 {
5667 regs.num_regs = nmatch;
5668 regs.start = TALLOC (nmatch, regoff_t);
5669 regs.end = TALLOC (nmatch, regoff_t);
5670 if (regs.start == NULL || regs.end == NULL)
5671 return (int) REG_NOMATCH;
5672 }
5673
5674 /* Perform the searching operation. */
5675 ret = re_search (&private_preg, string, len,
5676 /* start: */ 0, /* range: */ len,
5677 want_reg_info ? ®s : (struct re_registers *) 0);
5678
5679 /* Copy the register information to the POSIX structure. */
5680 if (want_reg_info)
5681 {
5682 if (ret >= 0)
5683 {
5684 unsigned r;
5685
5686 for (r = 0; r < nmatch; r++)
5687 {
5688 pmatch[r].rm_so = regs.start[r];
5689 pmatch[r].rm_eo = regs.end[r];
5690 }
5691 }
5692
5693 /* If we needed the temporary register info, free the space now. */
5694 free (regs.start);
5695 free (regs.end);
5696 }
5697
5698 /* We want zero return to mean success, unlike `re_search'. */
5699 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5700 }
5701
5702
5703 /* Returns a message corresponding to an error code, ERRCODE, returned
5704 from either regcomp or regexec. We don't use PREG here. */
5705
5706 size_t
regerror(errcode,preg,errbuf,errbuf_size)5707 regerror (errcode, preg, errbuf, errbuf_size)
5708 int errcode;
5709 const regex_t *preg;
5710 char *errbuf;
5711 size_t errbuf_size;
5712 {
5713 const char *msg;
5714 size_t msg_size;
5715
5716 if (errcode < 0
5717 || errcode >= (int) (sizeof (re_error_msgid)
5718 / sizeof (re_error_msgid[0])))
5719 /* Only error codes returned by the rest of the code should be passed
5720 to this routine. If we are given anything else, or if other regex
5721 code generates an invalid error code, then the program has a bug.
5722 Dump core so we can fix it. */
5723 call_abort ();
5724
5725 msg = gettext (re_error_msgid[errcode]);
5726
5727 msg_size = strlen (msg) + 1; /* Includes the null. */
5728
5729 if (errbuf_size != 0)
5730 {
5731 if (msg_size > errbuf_size)
5732 {
5733 strncpy (errbuf, msg, errbuf_size - 1);
5734 errbuf[errbuf_size - 1] = 0;
5735 }
5736 else
5737 strcpy (errbuf, msg);
5738 }
5739
5740 return msg_size;
5741 }
5742
5743
5744 /* Free dynamically allocated space used by PREG. */
5745
5746 void
regfree(preg)5747 regfree (preg)
5748 regex_t *preg;
5749 {
5750 if (preg->buffer != NULL)
5751 free (preg->buffer);
5752 preg->buffer = NULL;
5753
5754 preg->allocated = 0;
5755 preg->used = 0;
5756
5757 if (preg->fastmap != NULL)
5758 free (preg->fastmap);
5759 preg->fastmap = NULL;
5760 preg->fastmap_accurate = 0;
5761
5762 if (preg->translate != NULL)
5763 free (preg->translate);
5764 preg->translate = NULL;
5765 }
5766
5767 #endif /* not emacs */
5768