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[dragonfly.git] / gnu / lib / libregex / regex.c
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MD
1/* Extended regular expression matching and search library,
2 version 0.12.
3 (Implements POSIX draft P10003.2/D11.2, except for
4 internationalization features.)
5
6 Copyright (C) 1993 Free Software Foundation, Inc.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
21
22/* AIX requires this to be the first thing in the file. */
23#if defined (_AIX) && !defined (REGEX_MALLOC)
24 #pragma alloca
25#endif
26
27#define _GNU_SOURCE
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#if defined(STDC_HEADERS) && !defined(emacs)
34#include <stddef.h>
35#else
36/* We need this for `regex.h', and perhaps for the Emacs include files. */
37#include <sys/types.h>
38#endif
39
40/* The `emacs' switch turns on certain matching commands
41 that make sense only in Emacs. */
42#ifdef emacs
43
44#include "lisp.h"
45#include "buffer.h"
46#include "syntax.h"
47
48/* Emacs uses `NULL' as a predicate. */
49#undef NULL
50
51#else /* not emacs */
52
53/* We used to test for `BSTRING' here, but only GCC and Emacs define
54 `BSTRING', as far as I know, and neither of them use this code. */
55#if HAVE_STRING_H || STDC_HEADERS
56#include <string.h>
57#ifndef bcmp
58#define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
59#endif
60#ifndef bcopy
61#define bcopy(s, d, n) memcpy ((d), (s), (n))
62#endif
63#ifndef bzero
64#define bzero(s, n) memset ((s), 0, (n))
65#endif
66#else
67#include <strings.h>
68#endif
69
70#ifdef STDC_HEADERS
71#include <stdlib.h>
72#else
73char *malloc ();
74char *realloc ();
75#endif
76
77
78/* Define the syntax stuff for \<, \>, etc. */
79
80/* This must be nonzero for the wordchar and notwordchar pattern
81 commands in re_match_2. */
82#ifndef Sword
83#define Sword 1
84#endif
85
86#ifdef SYNTAX_TABLE
87
88extern char *re_syntax_table;
89
90#else /* not SYNTAX_TABLE */
91
92/* How many characters in the character set. */
93#define CHAR_SET_SIZE 256
94
95static char re_syntax_table[CHAR_SET_SIZE];
96
97static void
98init_syntax_once ()
99{
100 register int c;
101 static int done = 0;
102
103 if (done)
104 return;
105
106 bzero (re_syntax_table, sizeof re_syntax_table);
107
108 for (c = 'a'; c <= 'z'; c++)
109 re_syntax_table[c] = Sword;
110
111 for (c = 'A'; c <= 'Z'; c++)
112 re_syntax_table[c] = Sword;
113
114 for (c = '0'; c <= '9'; c++)
115 re_syntax_table[c] = Sword;
116
117 re_syntax_table['_'] = Sword;
118
119 done = 1;
120}
121
122#endif /* not SYNTAX_TABLE */
123
124#define SYNTAX(c) re_syntax_table[c]
125
126#endif /* not emacs */
127\f
128/* Get the interface, including the syntax bits. */
129#include "regex.h"
130
131/* isalpha etc. are used for the character classes. */
132#include <ctype.h>
133
134/* Jim Meyering writes:
135
136 "... Some ctype macros are valid only for character codes that
137 isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
138 using /bin/cc or gcc but without giving an ansi option). So, all
139 ctype uses should be through macros like ISPRINT... If
140 STDC_HEADERS is defined, then autoconf has verified that the ctype
141 macros don't need to be guarded with references to isascii. ...
142 Defining isascii to 1 should let any compiler worth its salt
143 eliminate the && through constant folding." */
144#if ! defined (isascii) || defined (STDC_HEADERS)
145#undef isascii
146#define isascii(c) 1
147#endif
148
149#ifdef isblank
150#define ISBLANK(c) (isascii (c) && isblank (c))
151#else
152#define ISBLANK(c) ((c) == ' ' || (c) == '\t')
153#endif
154#ifdef isgraph
155#define ISGRAPH(c) (isascii (c) && isgraph (c))
156#else
157#define ISGRAPH(c) (isascii (c) && isprint (c) && !isspace (c))
158#endif
159
160#define ISPRINT(c) (isascii (c) && isprint (c))
161#define ISDIGIT(c) (isascii (c) && isdigit (c))
162#define ISALNUM(c) (isascii (c) && isalnum (c))
163#define ISALPHA(c) (isascii (c) && isalpha (c))
164#define ISCNTRL(c) (isascii (c) && iscntrl (c))
165#define ISLOWER(c) (isascii (c) && islower (c))
166#define ISPUNCT(c) (isascii (c) && ispunct (c))
167#define ISSPACE(c) (isascii (c) && isspace (c))
168#define ISUPPER(c) (isascii (c) && isupper (c))
169#define ISXDIGIT(c) (isascii (c) && isxdigit (c))
170
171#ifndef NULL
172#define NULL 0
173#endif
174
175/* We remove any previous definition of `SIGN_EXTEND_CHAR',
176 since ours (we hope) works properly with all combinations of
177 machines, compilers, `char' and `unsigned char' argument types.
178 (Per Bothner suggested the basic approach.) */
179#undef SIGN_EXTEND_CHAR
180#if __STDC__
181#define SIGN_EXTEND_CHAR(c) ((signed char) (c))
182#else /* not __STDC__ */
183/* As in Harbison and Steele. */
184#define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
185#endif
186\f
187/* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
188 use `alloca' instead of `malloc'. This is because using malloc in
189 re_search* or re_match* could cause memory leaks when C-g is used in
190 Emacs; also, malloc is slower and causes storage fragmentation. On
191 the other hand, malloc is more portable, and easier to debug.
192
193 Because we sometimes use alloca, some routines have to be macros,
194 not functions -- `alloca'-allocated space disappears at the end of the
195 function it is called in. */
196
197#ifdef REGEX_MALLOC
198
199#define REGEX_ALLOCATE malloc
200#define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
201
202#else /* not REGEX_MALLOC */
203
204/* Emacs already defines alloca, sometimes. */
205#ifndef alloca
206
207/* Make alloca work the best possible way. */
208#ifdef __GNUC__
209#define alloca __builtin_alloca
210#else /* not __GNUC__ */
211#if HAVE_ALLOCA_H
212#include <alloca.h>
213#else /* not __GNUC__ or HAVE_ALLOCA_H */
214#ifndef _AIX /* Already did AIX, up at the top. */
215char *alloca ();
216#endif /* not _AIX */
217#endif /* not HAVE_ALLOCA_H */
218#endif /* not __GNUC__ */
219
220#endif /* not alloca */
221
222#define REGEX_ALLOCATE alloca
223
224/* Assumes a `char *destination' variable. */
225#define REGEX_REALLOCATE(source, osize, nsize) \
226 (destination = (char *) alloca (nsize), \
227 bcopy (source, destination, osize), \
228 destination)
229
230#endif /* not REGEX_MALLOC */
231
232
233/* True if `size1' is non-NULL and PTR is pointing anywhere inside
234 `string1' or just past its end. This works if PTR is NULL, which is
235 a good thing. */
236#define FIRST_STRING_P(ptr) \
237 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
238
239/* (Re)Allocate N items of type T using malloc, or fail. */
240#define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
241#define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
242#define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
243
244#define BYTEWIDTH 8 /* In bits. */
245
246#define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
247
248#define MAX(a, b) ((a) > (b) ? (a) : (b))
249#define MIN(a, b) ((a) < (b) ? (a) : (b))
250
251typedef char boolean;
252#define false 0
253#define true 1
254\f
255/* These are the command codes that appear in compiled regular
256 expressions. Some opcodes are followed by argument bytes. A
257 command code can specify any interpretation whatsoever for its
258 arguments. Zero bytes may appear in the compiled regular expression.
259
260 The value of `exactn' is needed in search.c (search_buffer) in Emacs.
261 So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of
262 `exactn' we use here must also be 1. */
263
264typedef enum
265{
266 no_op = 0,
267
268 /* Followed by one byte giving n, then by n literal bytes. */
269 exactn = 1,
270
271 /* Matches any (more or less) character. */
272 anychar,
273
274 /* Matches any one char belonging to specified set. First
275 following byte is number of bitmap bytes. Then come bytes
276 for a bitmap saying which chars are in. Bits in each byte
277 are ordered low-bit-first. A character is in the set if its
278 bit is 1. A character too large to have a bit in the map is
279 automatically not in the set. */
280 charset,
281
282 /* Same parameters as charset, but match any character that is
283 not one of those specified. */
284 charset_not,
285
286 /* Start remembering the text that is matched, for storing in a
287 register. Followed by one byte with the register number, in
288 the range 0 to one less than the pattern buffer's re_nsub
289 field. Then followed by one byte with the number of groups
290 inner to this one. (This last has to be part of the
291 start_memory only because we need it in the on_failure_jump
292 of re_match_2.) */
293 start_memory,
294
295 /* Stop remembering the text that is matched and store it in a
296 memory register. Followed by one byte with the register
297 number, in the range 0 to one less than `re_nsub' in the
298 pattern buffer, and one byte with the number of inner groups,
299 just like `start_memory'. (We need the number of inner
300 groups here because we don't have any easy way of finding the
301 corresponding start_memory when we're at a stop_memory.) */
302 stop_memory,
303
304 /* Match a duplicate of something remembered. Followed by one
305 byte containing the register number. */
306 duplicate,
307
308 /* Fail unless at beginning of line. */
309 begline,
310
311 /* Fail unless at end of line. */
312 endline,
313
314 /* Succeeds if at beginning of buffer (if emacs) or at beginning
315 of string to be matched (if not). */
316 begbuf,
317
318 /* Analogously, for end of buffer/string. */
319 endbuf,
320
321 /* Followed by two byte relative address to which to jump. */
322 jump,
323
324 /* Same as jump, but marks the end of an alternative. */
325 jump_past_alt,
326
327 /* Followed by two-byte relative address of place to resume at
328 in case of failure. */
329 on_failure_jump,
330
331 /* Like on_failure_jump, but pushes a placeholder instead of the
332 current string position when executed. */
333 on_failure_keep_string_jump,
334
335 /* Throw away latest failure point and then jump to following
336 two-byte relative address. */
337 pop_failure_jump,
338
339 /* Change to pop_failure_jump if know won't have to backtrack to
340 match; otherwise change to jump. This is used to jump
341 back to the beginning of a repeat. If what follows this jump
342 clearly won't match what the repeat does, such that we can be
343 sure that there is no use backtracking out of repetitions
344 already matched, then we change it to a pop_failure_jump.
345 Followed by two-byte address. */
346 maybe_pop_jump,
347
348 /* Jump to following two-byte address, and push a dummy failure
349 point. This failure point will be thrown away if an attempt
350 is made to use it for a failure. A `+' construct makes this
351 before the first repeat. Also used as an intermediary kind
352 of jump when compiling an alternative. */
353 dummy_failure_jump,
354
355 /* Push a dummy failure point and continue. Used at the end of
356 alternatives. */
357 push_dummy_failure,
358
359 /* Followed by two-byte relative address and two-byte number n.
360 After matching N times, jump to the address upon failure. */
361 succeed_n,
362
363 /* Followed by two-byte relative address, and two-byte number n.
364 Jump to the address N times, then fail. */
365 jump_n,
366
367 /* Set the following two-byte relative address to the
368 subsequent two-byte number. The address *includes* the two
369 bytes of number. */
370 set_number_at,
371
372 wordchar, /* Matches any word-constituent character. */
373 notwordchar, /* Matches any char that is not a word-constituent. */
374
375 wordbeg, /* Succeeds if at word beginning. */
376 wordend, /* Succeeds if at word end. */
377
378 wordbound, /* Succeeds if at a word boundary. */
379 notwordbound /* Succeeds if not at a word boundary. */
380
381#ifdef emacs
382 ,before_dot, /* Succeeds if before point. */
383 at_dot, /* Succeeds if at point. */
384 after_dot, /* Succeeds if after point. */
385
386 /* Matches any character whose syntax is specified. Followed by
387 a byte which contains a syntax code, e.g., Sword. */
388 syntaxspec,
389
390 /* Matches any character whose syntax is not that specified. */
391 notsyntaxspec
392#endif /* emacs */
393} re_opcode_t;
394\f
395/* Common operations on the compiled pattern. */
396
397/* Store NUMBER in two contiguous bytes starting at DESTINATION. */
398
399#define STORE_NUMBER(destination, number) \
400 do { \
401 (destination)[0] = (number) & 0377; \
402 (destination)[1] = (number) >> 8; \
403 } while (0)
404
405/* Same as STORE_NUMBER, except increment DESTINATION to
406 the byte after where the number is stored. Therefore, DESTINATION
407 must be an lvalue. */
408
409#define STORE_NUMBER_AND_INCR(destination, number) \
410 do { \
411 STORE_NUMBER (destination, number); \
412 (destination) += 2; \
413 } while (0)
414
415/* Put into DESTINATION a number stored in two contiguous bytes starting
416 at SOURCE. */
417
418#define EXTRACT_NUMBER(destination, source) \
419 do { \
420 (destination) = *(source) & 0377; \
421 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
422 } while (0)
423
424#ifdef DEBUG
425static void extract_number _RE_ARGS((int *dest, unsigned char *source));
426static void
427extract_number (dest, source)
428 int *dest;
429 unsigned char *source;
430{
431 int temp = SIGN_EXTEND_CHAR (*(source + 1));
432 *dest = *source & 0377;
433 *dest += temp << 8;
434}
435
436#ifndef EXTRACT_MACROS /* To debug the macros. */
437#undef EXTRACT_NUMBER
438#define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
439#endif /* not EXTRACT_MACROS */
440
441#endif /* DEBUG */
442
443/* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
444 SOURCE must be an lvalue. */
445
446#define EXTRACT_NUMBER_AND_INCR(destination, source) \
447 do { \
448 EXTRACT_NUMBER (destination, source); \
449 (source) += 2; \
450 } while (0)
451
452#ifdef DEBUG
453static void extract_number_and_incr _RE_ARGS((int *destination,
454 unsigned char **source));
455static void
456extract_number_and_incr (destination, source)
457 int *destination;
458 unsigned char **source;
459{
460 extract_number (destination, *source);
461 *source += 2;
462}
463
464#ifndef EXTRACT_MACROS
465#undef EXTRACT_NUMBER_AND_INCR
466#define EXTRACT_NUMBER_AND_INCR(dest, src) \
467 extract_number_and_incr (&dest, &src)
468#endif /* not EXTRACT_MACROS */
469
470#endif /* DEBUG */
471\f
472/* If DEBUG is defined, Regex prints many voluminous messages about what
473 it is doing (if the variable `debug' is nonzero). If linked with the
474 main program in `iregex.c', you can enter patterns and strings
475 interactively. And if linked with the main program in `main.c' and
476 the other test files, you can run the already-written tests. */
477
478#ifdef DEBUG
479
480/* We use standard I/O for debugging. */
481#include <stdio.h>
482
483/* It is useful to test things that ``must'' be true when debugging. */
484#include <assert.h>
485
486static int debug = 0;
487
488#define DEBUG_STATEMENT(e) e
489#define DEBUG_PRINT1(x) if (debug) printf (x)
490#define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
491#define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
492#define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
493#define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
494 if (debug) print_partial_compiled_pattern (s, e)
495#define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
496 if (debug) print_double_string (w, s1, sz1, s2, sz2)
497
498
499extern void printchar ();
500
501/* Print the fastmap in human-readable form. */
502
503void
504print_fastmap (fastmap)
505 char *fastmap;
506{
507 unsigned was_a_range = 0;
508 unsigned i = 0;
509
510 while (i < (1 << BYTEWIDTH))
511 {
512 if (fastmap[i++])
513 {
514 was_a_range = 0;
515 printchar (i - 1);
516 while (i < (1 << BYTEWIDTH) && fastmap[i])
517 {
518 was_a_range = 1;
519 i++;
520 }
521 if (was_a_range)
522 {
523 printf ("-");
524 printchar (i - 1);
525 }
526 }
527 }
528 putchar ('\n');
529}
530
531
532/* Print a compiled pattern string in human-readable form, starting at
533 the START pointer into it and ending just before the pointer END. */
534
535void
536print_partial_compiled_pattern (start, end)
537 unsigned char *start;
538 unsigned char *end;
539{
540 int mcnt, mcnt2;
541 unsigned char *p = start;
542 unsigned char *pend = end;
543
544 if (start == NULL)
545 {
546 printf ("(null)\n");
547 return;
548 }
549
550 /* Loop over pattern commands. */
551 while (p < pend)
552 {
553 printf ("%d:\t", p - start);
554
555 switch ((re_opcode_t) *p++)
556 {
557 case no_op:
558 printf ("/no_op");
559 break;
560
561 case exactn:
562 mcnt = *p++;
563 printf ("/exactn/%d", mcnt);
564 do
565 {
566 putchar ('/');
567 printchar (*p++);
568 }
569 while (--mcnt);
570 break;
571
572 case start_memory:
573 mcnt = *p++;
574 printf ("/start_memory/%d/%d", mcnt, *p++);
575 break;
576
577 case stop_memory:
578 mcnt = *p++;
579 printf ("/stop_memory/%d/%d", mcnt, *p++);
580 break;
581
582 case duplicate:
583 printf ("/duplicate/%d", *p++);
584 break;
585
586 case anychar:
587 printf ("/anychar");
588 break;
589
590 case charset:
591 case charset_not:
592 {
593 register int c, last = -100;
594 register int in_range = 0;
595
596 printf ("/charset [%s",
597 (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
598
599 assert (p + *p < pend);
600
601 for (c = 0; c < 256; c++)
602 if (c / 8 < *p
603 && (p[1 + (c/8)] & (1 << (c % 8))))
604 {
605 /* Are we starting a range? */
606 if (last + 1 == c && ! in_range)
607 {
608 putchar ('-');
609 in_range = 1;
610 }
611 /* Have we broken a range? */
612 else if (last + 1 != c && in_range)
613 {
614 printchar (last);
615 in_range = 0;
616 }
617
618 if (! in_range)
619 printchar (c);
620
621 last = c;
622 }
623
624 if (in_range)
625 printchar (last);
626
627 putchar (']');
628
629 p += 1 + *p;
630 }
631 break;
632
633 case begline:
634 printf ("/begline");
635 break;
636
637 case endline:
638 printf ("/endline");
639 break;
640
641 case on_failure_jump:
642 extract_number_and_incr (&mcnt, &p);
643 printf ("/on_failure_jump to %d", p + mcnt - start);
644 break;
645
646 case on_failure_keep_string_jump:
647 extract_number_and_incr (&mcnt, &p);
648 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
649 break;
650
651 case dummy_failure_jump:
652 extract_number_and_incr (&mcnt, &p);
653 printf ("/dummy_failure_jump to %d", p + mcnt - start);
654 break;
655
656 case push_dummy_failure:
657 printf ("/push_dummy_failure");
658 break;
659
660 case maybe_pop_jump:
661 extract_number_and_incr (&mcnt, &p);
662 printf ("/maybe_pop_jump to %d", p + mcnt - start);
663 break;
664
665 case pop_failure_jump:
666 extract_number_and_incr (&mcnt, &p);
667 printf ("/pop_failure_jump to %d", p + mcnt - start);
668 break;
669
670 case jump_past_alt:
671 extract_number_and_incr (&mcnt, &p);
672 printf ("/jump_past_alt to %d", p + mcnt - start);
673 break;
674
675 case jump:
676 extract_number_and_incr (&mcnt, &p);
677 printf ("/jump to %d", p + mcnt - start);
678 break;
679
680 case succeed_n:
681 extract_number_and_incr (&mcnt, &p);
682 extract_number_and_incr (&mcnt2, &p);
683 printf ("/succeed_n to %d, %d times", p + mcnt - start, mcnt2);
684 break;
685
686 case jump_n:
687 extract_number_and_incr (&mcnt, &p);
688 extract_number_and_incr (&mcnt2, &p);
689 printf ("/jump_n to %d, %d times", p + mcnt - start, mcnt2);
690 break;
691
692 case set_number_at:
693 extract_number_and_incr (&mcnt, &p);
694 extract_number_and_incr (&mcnt2, &p);
695 printf ("/set_number_at location %d to %d", p + mcnt - start, mcnt2);
696 break;
697
698 case wordbound:
699 printf ("/wordbound");
700 break;
701
702 case notwordbound:
703 printf ("/notwordbound");
704 break;
705
706 case wordbeg:
707 printf ("/wordbeg");
708 break;
709
710 case wordend:
711 printf ("/wordend");
712
713#ifdef emacs
714 case before_dot:
715 printf ("/before_dot");
716 break;
717
718 case at_dot:
719 printf ("/at_dot");
720 break;
721
722 case after_dot:
723 printf ("/after_dot");
724 break;
725
726 case syntaxspec:
727 printf ("/syntaxspec");
728 mcnt = *p++;
729 printf ("/%d", mcnt);
730 break;
731
732 case notsyntaxspec:
733 printf ("/notsyntaxspec");
734 mcnt = *p++;
735 printf ("/%d", mcnt);
736 break;
737#endif /* emacs */
738
739 case wordchar:
740 printf ("/wordchar");
741 break;
742
743 case notwordchar:
744 printf ("/notwordchar");
745 break;
746
747 case begbuf:
748 printf ("/begbuf");
749 break;
750
751 case endbuf:
752 printf ("/endbuf");
753 break;
754
755 default:
756 printf ("?%d", *(p-1));
757 }
758
759 putchar ('\n');
760 }
761
762 printf ("%d:\tend of pattern.\n", p - start);
763}
764
765
766void
767print_compiled_pattern (bufp)
768 struct re_pattern_buffer *bufp;
769{
770 unsigned char *buffer = bufp->buffer;
771
772 print_partial_compiled_pattern (buffer, buffer + bufp->used);
773 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
774
775 if (bufp->fastmap_accurate && bufp->fastmap)
776 {
777 printf ("fastmap: ");
778 print_fastmap (bufp->fastmap);
779 }
780
781 printf ("re_nsub: %d\t", bufp->re_nsub);
782 printf ("regs_alloc: %d\t", bufp->regs_allocated);
783 printf ("can_be_null: %d\t", bufp->can_be_null);
784 printf ("newline_anchor: %d\n", bufp->newline_anchor);
785 printf ("no_sub: %d\t", bufp->no_sub);
786 printf ("not_bol: %d\t", bufp->not_bol);
787 printf ("not_eol: %d\t", bufp->not_eol);
788 printf ("syntax: %d\n", bufp->syntax);
789 /* Perhaps we should print the translate table? */
790}
791
792
793void
794print_double_string (where, string1, size1, string2, size2)
795 const char *where;
796 const char *string1;
797 const char *string2;
798 int size1;
799 int size2;
800{
801 unsigned this_char;
802
803 if (where == NULL)
804 printf ("(null)");
805 else
806 {
807 if (FIRST_STRING_P (where))
808 {
809 for (this_char = where - string1; this_char < size1; this_char++)
810 printchar (string1[this_char]);
811
812 where = string2;
813 }
814
815 for (this_char = where - string2; this_char < size2; this_char++)
816 printchar (string2[this_char]);
817 }
818}
819
820#else /* not DEBUG */
821
822#undef assert
823#define assert(e)
824
825#define DEBUG_STATEMENT(e)
826#define DEBUG_PRINT1(x)
827#define DEBUG_PRINT2(x1, x2)
828#define DEBUG_PRINT3(x1, x2, x3)
829#define DEBUG_PRINT4(x1, x2, x3, x4)
830#define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
831#define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
832
833#endif /* not DEBUG */
834\f
835/* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
836 also be assigned to arbitrarily: each pattern buffer stores its own
837 syntax, so it can be changed between regex compilations. */
838reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS;
839
840
841/* Specify the precise syntax of regexps for compilation. This provides
842 for compatibility for various utilities which historically have
843 different, incompatible syntaxes.
844
845 The argument SYNTAX is a bit mask comprised of the various bits
846 defined in regex.h. We return the old syntax. */
847
848reg_syntax_t
849re_set_syntax (syntax)
850 reg_syntax_t syntax;
851{
852 reg_syntax_t ret = re_syntax_options;
853
854 re_syntax_options = syntax;
855 return ret;
856}
857\f
858/* This table gives an error message for each of the error codes listed
859 in regex.h. Obviously the order here has to be same as there. */
860
861static const char *re_error_msg[] =
862 { NULL, /* REG_NOERROR */
863 "No match", /* REG_NOMATCH */
864 "Invalid regular expression", /* REG_BADPAT */
865 "Invalid collation character", /* REG_ECOLLATE */
866 "Invalid character class name", /* REG_ECTYPE */
867 "Trailing backslash", /* REG_EESCAPE */
868 "Invalid back reference", /* REG_ESUBREG */
869 "Unmatched [ or [^", /* REG_EBRACK */
870 "Unmatched ( or \\(", /* REG_EPAREN */
871 "Unmatched \\{", /* REG_EBRACE */
872 "Invalid content of \\{\\}", /* REG_BADBR */
873 "Invalid range end", /* REG_ERANGE */
874 "Memory exhausted", /* REG_ESPACE */
875 "Invalid preceding regular expression", /* REG_BADRPT */
876 "Premature end of regular expression", /* REG_EEND */
877 "Regular expression too big", /* REG_ESIZE */
878 "Unmatched ) or \\)", /* REG_ERPAREN */
879 };
880\f
881/* Subroutine declarations and macros for regex_compile. */
882
883static reg_errcode_t regex_compile _RE_ARGS((const char *pattern, size_t size,
884 reg_syntax_t syntax,
885 struct re_pattern_buffer *bufp));
886static void store_op1 _RE_ARGS((re_opcode_t op, unsigned char *loc, int arg));
887static void store_op2 _RE_ARGS((re_opcode_t op, unsigned char *loc,
888 int arg1, int arg2));
889static void insert_op1 _RE_ARGS((re_opcode_t op, unsigned char *loc,
890 int arg, unsigned char *end));
891static void insert_op2 _RE_ARGS((re_opcode_t op, unsigned char *loc,
892 int arg1, int arg2, unsigned char *end));
893static boolean at_begline_loc_p _RE_ARGS((const char *pattern, const char *p,
894 reg_syntax_t syntax));
895static boolean at_endline_loc_p _RE_ARGS((const char *p, const char *pend,
896 reg_syntax_t syntax));
897static reg_errcode_t compile_range _RE_ARGS((const char **p_ptr,
898 const char *pend,
899 char *translate,
900 reg_syntax_t syntax,
901 unsigned char *b));
902
903/* Fetch the next character in the uncompiled pattern---translating it
904 if necessary. Also cast from a signed character in the constant
905 string passed to us by the user to an unsigned char that we can use
906 as an array index (in, e.g., `translate'). */
907#define PATFETCH(c) \
908 do {if (p == pend) return REG_EEND; \
909 c = (unsigned char) *p++; \
910 if (translate) c = translate[c]; \
911 } while (0)
912
913/* Fetch the next character in the uncompiled pattern, with no
914 translation. */
915#define PATFETCH_RAW(c) \
916 do {if (p == pend) return REG_EEND; \
917 c = (unsigned char) *p++; \
918 } while (0)
919
920/* Go backwards one character in the pattern. */
921#define PATUNFETCH p--
922
923
924/* If `translate' is non-null, return translate[D], else just D. We
925 cast the subscript to translate because some data is declared as
926 `char *', to avoid warnings when a string constant is passed. But
927 when we use a character as a subscript we must make it unsigned. */
928#define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
929
930
931/* Macros for outputting the compiled pattern into `buffer'. */
932
933/* If the buffer isn't allocated when it comes in, use this. */
934#define INIT_BUF_SIZE 32
935
936/* Make sure we have at least N more bytes of space in buffer. */
937#define GET_BUFFER_SPACE(n) \
938 while (b - bufp->buffer + (n) > bufp->allocated) \
939 EXTEND_BUFFER ()
940
941/* Make sure we have one more byte of buffer space and then add C to it. */
942#define BUF_PUSH(c) \
943 do { \
944 GET_BUFFER_SPACE (1); \
945 *b++ = (unsigned char) (c); \
946 } while (0)
947
948
949/* Ensure we have two more bytes of buffer space and then append C1 and C2. */
950#define BUF_PUSH_2(c1, c2) \
951 do { \
952 GET_BUFFER_SPACE (2); \
953 *b++ = (unsigned char) (c1); \
954 *b++ = (unsigned char) (c2); \
955 } while (0)
956
957
958/* As with BUF_PUSH_2, except for three bytes. */
959#define BUF_PUSH_3(c1, c2, c3) \
960 do { \
961 GET_BUFFER_SPACE (3); \
962 *b++ = (unsigned char) (c1); \
963 *b++ = (unsigned char) (c2); \
964 *b++ = (unsigned char) (c3); \
965 } while (0)
966
967
968/* Store a jump with opcode OP at LOC to location TO. We store a
969 relative address offset by the three bytes the jump itself occupies. */
970#define STORE_JUMP(op, loc, to) \
971 store_op1 (op, loc, (int)((to) - (loc) - 3))
972
973/* Likewise, for a two-argument jump. */
974#define STORE_JUMP2(op, loc, to, arg) \
975 store_op2 (op, loc, (int)((to) - (loc) - 3), arg)
976
977/* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
978#define INSERT_JUMP(op, loc, to) \
979 insert_op1 (op, loc, (int)((to) - (loc) - 3), b)
980
981/* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
982#define INSERT_JUMP2(op, loc, to, arg) \
983 insert_op2 (op, loc, (int)((to) - (loc) - 3), arg, b)
984
985
986/* This is not an arbitrary limit: the arguments which represent offsets
987 into the pattern are two bytes long. So if 2^16 bytes turns out to
988 be too small, many things would have to change. */
989/* Any other compiler which, like MSC, has allocation limit below 2^16
990 bytes will have to use approach similar to what was done below for
991 MSC and drop MAX_BUF_SIZE a bit. Otherwise you may end up
992 reallocating to 0 bytes. Such thing is not going to work too well.
993 You have been warned!! */
994#ifdef _MSC_VER
995/* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
996 The REALLOC define eliminates a flurry of conversion warnings,
997 but is not required. */
998#define MAX_BUF_SIZE 65500L
999#define REALLOC(p,s) realloc((p), (size_t) (s))
1000#else
1001#define MAX_BUF_SIZE (1L << 16)
1002#define REALLOC realloc
1003#endif
1004
1005/* Extend the buffer by twice its current size via realloc and
1006 reset the pointers that pointed into the old block to point to the
1007 correct places in the new one. If extending the buffer results in it
1008 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1009#define EXTEND_BUFFER() \
1010 do { \
1011 unsigned char *old_buffer = bufp->buffer; \
1012 if (bufp->allocated == MAX_BUF_SIZE) \
1013 return REG_ESIZE; \
1014 bufp->allocated <<= 1; \
1015 if (bufp->allocated > MAX_BUF_SIZE) \
1016 bufp->allocated = MAX_BUF_SIZE; \
1017 bufp->buffer = (unsigned char *) REALLOC(bufp->buffer, bufp->allocated);\
1018 if (bufp->buffer == NULL) \
1019 return REG_ESPACE; \
1020 /* If the buffer moved, move all the pointers into it. */ \
1021 if (old_buffer != bufp->buffer) \
1022 { \
1023 b = (b - old_buffer) + bufp->buffer; \
1024 begalt = (begalt - old_buffer) + bufp->buffer; \
1025 if (fixup_alt_jump) \
1026 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1027 if (laststart) \
1028 laststart = (laststart - old_buffer) + bufp->buffer; \
1029 if (pending_exact) \
1030 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1031 } \
1032 } while (0)
1033
1034
1035/* Since we have one byte reserved for the register number argument to
1036 {start,stop}_memory, the maximum number of groups we can report
1037 things about is what fits in that byte. */
1038#define MAX_REGNUM 255
1039
1040/* But patterns can have more than `MAX_REGNUM' registers. We just
1041 ignore the excess. */
1042typedef unsigned regnum_t;
1043
1044
1045/* Macros for the compile stack. */
1046
1047/* Since offsets can go either forwards or backwards, this type needs to
1048 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1049/* int may be not enough when sizeof(int) == 2 */
1050typedef long pattern_offset_t;
1051
1052typedef struct
1053{
1054 pattern_offset_t begalt_offset;
1055 pattern_offset_t fixup_alt_jump;
1056 pattern_offset_t inner_group_offset;
1057 pattern_offset_t laststart_offset;
1058 regnum_t regnum;
1059} compile_stack_elt_t;
1060
1061
1062typedef struct
1063{
1064 compile_stack_elt_t *stack;
1065 unsigned size;
1066 unsigned avail; /* Offset of next open position. */
1067} compile_stack_type;
1068
1069
1070#define INIT_COMPILE_STACK_SIZE 32
1071
1072#define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1073#define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1074
1075/* The next available element. */
1076#define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1077
1078
1079/* Set the bit for character C in a list. */
1080#define SET_LIST_BIT(c) \
1081 (b[((unsigned char) (c)) / BYTEWIDTH] \
1082 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1083
1084
1085/* Get the next unsigned number in the uncompiled pattern. */
1086#define GET_UNSIGNED_NUMBER(num) \
1087 { if (p != pend) \
1088 { \
1089 PATFETCH (c); \
1090 while (ISDIGIT (c)) \
1091 { \
1092 if (num < 0) \
1093 num = 0; \
1094 num = num * 10 + c - '0'; \
1095 if (p == pend) \
1096 break; \
1097 PATFETCH (c); \
1098 } \
1099 } \
1100 }
1101
1102#define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1103
1104#define IS_CHAR_CLASS(string) \
1105 (STREQ (string, "alpha") || STREQ (string, "upper") \
1106 || STREQ (string, "lower") || STREQ (string, "digit") \
1107 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1108 || STREQ (string, "space") || STREQ (string, "print") \
1109 || STREQ (string, "punct") || STREQ (string, "graph") \
1110 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1111\f
1112static boolean group_in_compile_stack _RE_ARGS((compile_stack_type
1113 compile_stack,
1114 regnum_t regnum));
1115
1116#ifdef __FreeBSD__
1117static int collate_range_cmp (a, b)
1118 int a, b;
1119{
1120 int r;
1121 static char s[2][2];
1122
1123 if ((unsigned char)a == (unsigned char)b)
1124 return 0;
1125 s[0][0] = a;
1126 s[1][0] = b;
1127 if ((r = strcoll(s[0], s[1])) == 0)
1128 r = (unsigned char)a - (unsigned char)b;
1129 return r;
1130}
1131#endif
1132
1133/* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1134 Returns one of error codes defined in `regex.h', or zero for success.
1135
1136 Assumes the `allocated' (and perhaps `buffer') and `translate'
1137 fields are set in BUFP on entry.
1138
1139 If it succeeds, results are put in BUFP (if it returns an error, the
1140 contents of BUFP are undefined):
1141 `buffer' is the compiled pattern;
1142 `syntax' is set to SYNTAX;
1143 `used' is set to the length of the compiled pattern;
1144 `fastmap_accurate' is zero;
1145 `re_nsub' is the number of subexpressions in PATTERN;
1146 `not_bol' and `not_eol' are zero;
1147
1148 The `fastmap' and `newline_anchor' fields are neither
1149 examined nor set. */
1150
1151static reg_errcode_t
1152regex_compile (pattern, size, syntax, bufp)
1153 const char *pattern;
1154 size_t size;
1155 reg_syntax_t syntax;
1156 struct re_pattern_buffer *bufp;
1157{
1158 /* We fetch characters from PATTERN here. Even though PATTERN is
1159 `char *' (i.e., signed), we declare these variables as unsigned, so
1160 they can be reliably used as array indices. */
1161 register unsigned char c, c1;
1162
1163 /* A random tempory spot in PATTERN. */
1164 const char *p1;
1165
1166 /* Points to the end of the buffer, where we should append. */
1167 register unsigned char *b;
1168
1169 /* Keeps track of unclosed groups. */
1170 compile_stack_type compile_stack;
1171
1172 /* Points to the current (ending) position in the pattern. */
1173 const char *p = pattern;
1174 const char *pend = pattern + size;
1175
1176 /* How to translate the characters in the pattern. */
1177 char *translate = bufp->translate;
1178
1179 /* Address of the count-byte of the most recently inserted `exactn'
1180 command. This makes it possible to tell if a new exact-match
1181 character can be added to that command or if the character requires
1182 a new `exactn' command. */
1183 unsigned char *pending_exact = 0;
1184
1185 /* Address of start of the most recently finished expression.
1186 This tells, e.g., postfix * where to find the start of its
1187 operand. Reset at the beginning of groups and alternatives. */
1188 unsigned char *laststart = 0;
1189
1190 /* Address of beginning of regexp, or inside of last group. */
1191 unsigned char *begalt;
1192
1193 /* Place in the uncompiled pattern (i.e., the {) to
1194 which to go back if the interval is invalid. */
1195 const char *beg_interval;
1196
1197 /* Address of the place where a forward jump should go to the end of
1198 the containing expression. Each alternative of an `or' -- except the
1199 last -- ends with a forward jump of this sort. */
1200 unsigned char *fixup_alt_jump = 0;
1201
1202 /* Counts open-groups as they are encountered. Remembered for the
1203 matching close-group on the compile stack, so the same register
1204 number is put in the stop_memory as the start_memory. */
1205 regnum_t regnum = 0;
1206
1207#ifdef DEBUG
1208 DEBUG_PRINT1 ("\nCompiling pattern: ");
1209 if (debug)
1210 {
1211 unsigned debug_count;
1212
1213 for (debug_count = 0; debug_count < size; debug_count++)
1214 printchar (pattern[debug_count]);
1215 putchar ('\n');
1216 }
1217#endif /* DEBUG */
1218
1219 /* Initialize the compile stack. */
1220 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1221 if (compile_stack.stack == NULL)
1222 return REG_ESPACE;
1223
1224 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1225 compile_stack.avail = 0;
1226
1227 /* Initialize the pattern buffer. */
1228 bufp->syntax = syntax;
1229 bufp->fastmap_accurate = 0;
1230 bufp->not_bol = bufp->not_eol = 0;
1231
1232 /* Set `used' to zero, so that if we return an error, the pattern
1233 printer (for debugging) will think there's no pattern. We reset it
1234 at the end. */
1235 bufp->used = 0;
1236
1237 /* Always count groups, whether or not bufp->no_sub is set. */
1238 bufp->re_nsub = 0;
1239
1240#if !defined (emacs) && !defined (SYNTAX_TABLE)
1241 /* Initialize the syntax table. */
1242 init_syntax_once ();
1243#endif
1244
1245 if (bufp->allocated == 0)
1246 {
1247 if (bufp->buffer)
1248 { /* If zero allocated, but buffer is non-null, try to realloc
1249 enough space. This loses if buffer's address is bogus, but
1250 that is the user's responsibility. */
1251 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1252 }
1253 else
1254 { /* Caller did not allocate a buffer. Do it for them. */
1255 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1256 }
1257 if (!bufp->buffer) return REG_ESPACE;
1258
1259 bufp->allocated = INIT_BUF_SIZE;
1260 }
1261
1262 begalt = b = bufp->buffer;
1263
1264 /* Loop through the uncompiled pattern until we're at the end. */
1265 while (p != pend)
1266 {
1267 PATFETCH (c);
1268
1269 switch (c)
1270 {
1271 case '^':
1272 {
1273 if ( /* If at start of pattern, it's an operator. */
1274 p == pattern + 1
1275 /* If context independent, it's an operator. */
1276 || syntax & RE_CONTEXT_INDEP_ANCHORS
1277 /* Otherwise, depends on what's come before. */
1278 || at_begline_loc_p (pattern, p, syntax))
1279 BUF_PUSH (begline);
1280 else
1281 goto normal_char;
1282 }
1283 break;
1284
1285
1286 case '$':
1287 {
1288 if ( /* If at end of pattern, it's an operator. */
1289 p == pend
1290 /* If context independent, it's an operator. */
1291 || syntax & RE_CONTEXT_INDEP_ANCHORS
1292 /* Otherwise, depends on what's next. */
1293 || at_endline_loc_p (p, pend, syntax))
1294 BUF_PUSH (endline);
1295 else
1296 goto normal_char;
1297 }
1298 break;
1299
1300
1301 case '+':
1302 case '?':
1303 if ((syntax & RE_BK_PLUS_QM)
1304 || (syntax & RE_LIMITED_OPS))
1305 goto normal_char;
1306 handle_plus:
1307 case '*':
1308 /* If there is no previous pattern... */
1309 if (!laststart)
1310 {
1311 if (syntax & RE_CONTEXT_INVALID_OPS)
1312 return REG_BADRPT;
1313 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1314 goto normal_char;
1315 }
1316
1317 {
1318 /* Are we optimizing this jump? */
1319 boolean keep_string_p = false;
1320
1321 /* 1 means zero (many) matches is allowed. */
1322 char zero_times_ok = 0, many_times_ok = 0;
1323
1324 /* If there is a sequence of repetition chars, collapse it
1325 down to just one (the right one). We can't combine
1326 interval operators with these because of, e.g., `a{2}*',
1327 which should only match an even number of `a's. */
1328
1329 for (;;)
1330 {
1331 zero_times_ok |= c != '+';
1332 many_times_ok |= c != '?';
1333
1334 if (p == pend)
1335 break;
1336
1337 PATFETCH (c);
1338
1339 if (c == '*'
1340 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1341 ;
1342
1343 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1344 {
1345 if (p == pend) return REG_EESCAPE;
1346
1347 PATFETCH (c1);
1348 if (!(c1 == '+' || c1 == '?'))
1349 {
1350 PATUNFETCH;
1351 PATUNFETCH;
1352 break;
1353 }
1354
1355 c = c1;
1356 }
1357 else
1358 {
1359 PATUNFETCH;
1360 break;
1361 }
1362
1363 /* If we get here, we found another repeat character. */
1364 }
1365
1366 /* Star, etc. applied to an empty pattern is equivalent
1367 to an empty pattern. */
1368 if (!laststart)
1369 break;
1370
1371 /* Now we know whether or not zero matches is allowed
1372 and also whether or not two or more matches is allowed. */
1373 if (many_times_ok)
1374 { /* More than one repetition is allowed, so put in at the
1375 end a backward relative jump from `b' to before the next
1376 jump we're going to put in below (which jumps from
1377 laststart to after this jump).
1378
1379 But if we are at the `*' in the exact sequence `.*\n',
1380 insert an unconditional jump backwards to the .,
1381 instead of the beginning of the loop. This way we only
1382 push a failure point once, instead of every time
1383 through the loop. */
1384 assert (p - 1 > pattern);
1385
1386 /* Allocate the space for the jump. */
1387 GET_BUFFER_SPACE (3);
1388
1389 /* We know we are not at the first character of the pattern,
1390 because laststart was nonzero. And we've already
1391 incremented `p', by the way, to be the character after
1392 the `*'. Do we have to do something analogous here
1393 for null bytes, because of RE_DOT_NOT_NULL? */
1394 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1395 && zero_times_ok
1396 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1397 && !(syntax & RE_DOT_NEWLINE))
1398 { /* We have .*\n. */
1399 STORE_JUMP (jump, b, laststart);
1400 keep_string_p = true;
1401 }
1402 else
1403 /* Anything else. */
1404 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1405
1406 /* We've added more stuff to the buffer. */
1407 b += 3;
1408 }
1409
1410 /* On failure, jump from laststart to b + 3, which will be the
1411 end of the buffer after this jump is inserted. */
1412 GET_BUFFER_SPACE (3);
1413 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1414 : on_failure_jump,
1415 laststart, b + 3);
1416 pending_exact = 0;
1417 b += 3;
1418
1419 if (!zero_times_ok)
1420 {
1421 /* At least one repetition is required, so insert a
1422 `dummy_failure_jump' before the initial
1423 `on_failure_jump' instruction of the loop. This
1424 effects a skip over that instruction the first time
1425 we hit that loop. */
1426 GET_BUFFER_SPACE (3);
1427 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1428 b += 3;
1429 }
1430 }
1431 break;
1432
1433
1434 case '.':
1435 laststart = b;
1436 BUF_PUSH (anychar);
1437 break;
1438
1439
1440 case '[':
1441 {
1442 boolean had_char_class = false;
1443
1444 if (p == pend) return REG_EBRACK;
1445
1446 /* Ensure that we have enough space to push a charset: the
1447 opcode, the length count, and the bitset; 34 bytes in all. */
1448 GET_BUFFER_SPACE (34);
1449
1450 laststart = b;
1451
1452 /* We test `*p == '^' twice, instead of using an if
1453 statement, so we only need one BUF_PUSH. */
1454 BUF_PUSH (*p == '^' ? charset_not : charset);
1455 if (*p == '^')
1456 p++;
1457
1458 /* Remember the first position in the bracket expression. */
1459 p1 = p;
1460
1461 /* Push the number of bytes in the bitmap. */
1462 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1463
1464 /* Clear the whole map. */
1465 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1466
1467 /* charset_not matches newline according to a syntax bit. */
1468 if ((re_opcode_t) b[-2] == charset_not
1469 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1470 SET_LIST_BIT ('\n');
1471
1472 /* Read in characters and ranges, setting map bits. */
1473 for (;;)
1474 {
1475 if (p == pend) return REG_EBRACK;
1476
1477 PATFETCH (c);
1478
1479 /* \ might escape characters inside [...] and [^...]. */
1480 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1481 {
1482 if (p == pend) return REG_EESCAPE;
1483
1484 PATFETCH (c1);
1485 SET_LIST_BIT (c1);
1486 continue;
1487 }
1488
1489 /* Could be the end of the bracket expression. If it's
1490 not (i.e., when the bracket expression is `[]' so
1491 far), the ']' character bit gets set way below. */
1492 if (c == ']' && p != p1 + 1)
1493 break;
1494
1495 /* Look ahead to see if it's a range when the last thing
1496 was a character class. */
1497 if (had_char_class && c == '-' && *p != ']')
1498 return REG_ERANGE;
1499
1500 /* Look ahead to see if it's a range when the last thing
1501 was a character: if this is a hyphen not at the
1502 beginning or the end of a list, then it's the range
1503 operator. */
1504 if (c == '-'
1505 && !(p - 2 >= pattern && p[-2] == '[')
1506 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1507 && *p != ']')
1508 {
1509 reg_errcode_t ret
1510 = compile_range (&p, pend, translate, syntax, b);
1511 if (ret != REG_NOERROR) return ret;
1512 }
1513
1514 else if (p[0] == '-' && p[1] != ']')
1515 { /* This handles ranges made up of characters only. */
1516 reg_errcode_t ret;
1517
1518 /* Move past the `-'. */
1519 PATFETCH (c1);
1520
1521 ret = compile_range (&p, pend, translate, syntax, b);
1522 if (ret != REG_NOERROR) return ret;
1523 }
1524
1525 /* See if we're at the beginning of a possible character
1526 class. */
1527
1528 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1529 { /* Leave room for the null. */
1530 char str[CHAR_CLASS_MAX_LENGTH + 1];
1531
1532 PATFETCH (c);
1533 c1 = 0;
1534
1535 /* If pattern is `[[:'. */
1536 if (p == pend) return REG_EBRACK;
1537
1538 for (;;)
1539 {
1540 PATFETCH (c);
1541 if (c == ':' || c == ']' || p == pend
1542 || c1 == CHAR_CLASS_MAX_LENGTH)
1543 break;
1544 str[c1++] = c;
1545 }
1546 str[c1] = '\0';
1547
1548 /* If isn't a word bracketed by `[:' and:`]':
1549 undo the ending character, the letters, and leave
1550 the leading `:' and `[' (but set bits for them). */
1551 if (c == ':' && *p == ']')
1552 {
1553 int ch;
1554 boolean is_alnum = STREQ (str, "alnum");
1555 boolean is_alpha = STREQ (str, "alpha");
1556 boolean is_blank = STREQ (str, "blank");
1557 boolean is_cntrl = STREQ (str, "cntrl");
1558 boolean is_digit = STREQ (str, "digit");
1559 boolean is_graph = STREQ (str, "graph");
1560 boolean is_lower = STREQ (str, "lower");
1561 boolean is_print = STREQ (str, "print");
1562 boolean is_punct = STREQ (str, "punct");
1563 boolean is_space = STREQ (str, "space");
1564 boolean is_upper = STREQ (str, "upper");
1565 boolean is_xdigit = STREQ (str, "xdigit");
1566
1567 if (!IS_CHAR_CLASS (str)) return REG_ECTYPE;
1568
1569 /* Throw away the ] at the end of the character
1570 class. */
1571 PATFETCH (c);
1572
1573 if (p == pend) return REG_EBRACK;
1574
1575 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
1576 {
1577 if ( (is_alnum && ISALNUM (ch))
1578 || (is_alpha && ISALPHA (ch))
1579 || (is_blank && ISBLANK (ch))
1580 || (is_cntrl && ISCNTRL (ch))
1581 || (is_digit && ISDIGIT (ch))
1582 || (is_graph && ISGRAPH (ch))
1583 || (is_lower && ISLOWER (ch))
1584 || (is_print && ISPRINT (ch))
1585 || (is_punct && ISPUNCT (ch))
1586 || (is_space && ISSPACE (ch))
1587 || (is_upper && ISUPPER (ch))
1588 || (is_xdigit && ISXDIGIT (ch)))
1589 SET_LIST_BIT (ch);
1590 }
1591 had_char_class = true;
1592 }
1593 else
1594 {
1595 c1++;
1596 while (c1--)
1597 PATUNFETCH;
1598 SET_LIST_BIT ('[');
1599 SET_LIST_BIT (':');
1600 had_char_class = false;
1601 }
1602 }
1603 else
1604 {
1605 had_char_class = false;
1606 SET_LIST_BIT (c);
1607 }
1608 }
1609
1610 /* Discard any (non)matching list bytes that are all 0 at the
1611 end of the map. Decrease the map-length byte too. */
1612 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
1613 b[-1]--;
1614 b += b[-1];
1615 }
1616 break;
1617
1618
1619 case '(':
1620 if (syntax & RE_NO_BK_PARENS)
1621 goto handle_open;
1622 else
1623 goto normal_char;
1624
1625
1626 case ')':
1627 if (syntax & RE_NO_BK_PARENS)
1628 goto handle_close;
1629 else
1630 goto normal_char;
1631
1632
1633 case '\n':
1634 if (syntax & RE_NEWLINE_ALT)
1635 goto handle_alt;
1636 else
1637 goto normal_char;
1638
1639
1640 case '|':
1641 if (syntax & RE_NO_BK_VBAR)
1642 goto handle_alt;
1643 else
1644 goto normal_char;
1645
1646
1647 case '{':
1648 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
1649 goto handle_interval;
1650 else
1651 goto normal_char;
1652
1653
1654 case '\\':
1655 if (p == pend) return REG_EESCAPE;
1656
1657 /* Do not translate the character after the \, so that we can
1658 distinguish, e.g., \B from \b, even if we normally would
1659 translate, e.g., B to b. */
1660 PATFETCH_RAW (c);
1661
1662 switch (c)
1663 {
1664 case '(':
1665 if (syntax & RE_NO_BK_PARENS)
1666 goto normal_backslash;
1667
1668 handle_open:
1669 bufp->re_nsub++;
1670 regnum++;
1671
1672 if (COMPILE_STACK_FULL)
1673 {
1674 RETALLOC (compile_stack.stack, compile_stack.size << 1,
1675 compile_stack_elt_t);
1676 if (compile_stack.stack == NULL) return REG_ESPACE;
1677
1678 compile_stack.size <<= 1;
1679 }
1680
1681 /* These are the values to restore when we hit end of this
1682 group. They are all relative offsets, so that if the
1683 whole pattern moves because of realloc, they will still
1684 be valid. */
1685 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
1686 COMPILE_STACK_TOP.fixup_alt_jump
1687 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
1688 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
1689 COMPILE_STACK_TOP.regnum = regnum;
1690
1691 /* We will eventually replace the 0 with the number of
1692 groups inner to this one. But do not push a
1693 start_memory for groups beyond the last one we can
1694 represent in the compiled pattern. */
1695 if (regnum <= MAX_REGNUM)
1696 {
1697 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
1698 BUF_PUSH_3 (start_memory, regnum, 0);
1699 }
1700
1701 compile_stack.avail++;
1702
1703 fixup_alt_jump = 0;
1704 laststart = 0;
1705 begalt = b;
1706 /* If we've reached MAX_REGNUM groups, then this open
1707 won't actually generate any code, so we'll have to
1708 clear pending_exact explicitly. */
1709 pending_exact = 0;
1710 break;
1711
1712
1713 case ')':
1714 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
1715
1716 if (COMPILE_STACK_EMPTY)
1717 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1718 goto normal_backslash;
1719 else
1720 return REG_ERPAREN;
1721
1722 handle_close:
1723 if (fixup_alt_jump)
1724 { /* Push a dummy failure point at the end of the
1725 alternative for a possible future
1726 `pop_failure_jump' to pop. See comments at
1727 `push_dummy_failure' in `re_match_2'. */
1728 BUF_PUSH (push_dummy_failure);
1729
1730 /* We allocated space for this jump when we assigned
1731 to `fixup_alt_jump', in the `handle_alt' case below. */
1732 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
1733 }
1734
1735 /* See similar code for backslashed left paren above. */
1736 if (COMPILE_STACK_EMPTY)
1737 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1738 goto normal_char;
1739 else
1740 return REG_ERPAREN;
1741
1742 /* Since we just checked for an empty stack above, this
1743 ``can't happen''. */
1744 assert (compile_stack.avail != 0);
1745 {
1746 /* We don't just want to restore into `regnum', because
1747 later groups should continue to be numbered higher,
1748 as in `(ab)c(de)' -- the second group is #2. */
1749 regnum_t this_group_regnum;
1750
1751 compile_stack.avail--;
1752 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
1753 fixup_alt_jump
1754 = COMPILE_STACK_TOP.fixup_alt_jump
1755 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
1756 : 0;
1757 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
1758 this_group_regnum = COMPILE_STACK_TOP.regnum;
1759 /* If we've reached MAX_REGNUM groups, then this open
1760 won't actually generate any code, so we'll have to
1761 clear pending_exact explicitly. */
1762 pending_exact = 0;
1763
1764 /* We're at the end of the group, so now we know how many
1765 groups were inside this one. */
1766 if (this_group_regnum <= MAX_REGNUM)
1767 {
1768 unsigned char *inner_group_loc
1769 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
1770
1771 *inner_group_loc = regnum - this_group_regnum;
1772 BUF_PUSH_3 (stop_memory, this_group_regnum,
1773 regnum - this_group_regnum);
1774 }
1775 }
1776 break;
1777
1778
1779 case '|': /* `\|'. */
1780 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
1781 goto normal_backslash;
1782 handle_alt:
1783 if (syntax & RE_LIMITED_OPS)
1784 goto normal_char;
1785
1786 /* Insert before the previous alternative a jump which
1787 jumps to this alternative if the former fails. */
1788 GET_BUFFER_SPACE (3);
1789 INSERT_JUMP (on_failure_jump, begalt, b + 6);
1790 pending_exact = 0;
1791 b += 3;
1792
1793 /* The alternative before this one has a jump after it
1794 which gets executed if it gets matched. Adjust that
1795 jump so it will jump to this alternative's analogous
1796 jump (put in below, which in turn will jump to the next
1797 (if any) alternative's such jump, etc.). The last such
1798 jump jumps to the correct final destination. A picture:
1799 _____ _____
1800 | | | |
1801 | v | v
1802 a | b | c
1803
1804 If we are at `b', then fixup_alt_jump right now points to a
1805 three-byte space after `a'. We'll put in the jump, set
1806 fixup_alt_jump to right after `b', and leave behind three
1807 bytes which we'll fill in when we get to after `c'. */
1808
1809 if (fixup_alt_jump)
1810 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
1811
1812 /* Mark and leave space for a jump after this alternative,
1813 to be filled in later either by next alternative or
1814 when know we're at the end of a series of alternatives. */
1815 fixup_alt_jump = b;
1816 GET_BUFFER_SPACE (3);
1817 b += 3;
1818
1819 laststart = 0;
1820 begalt = b;
1821 break;
1822
1823
1824 case '{':
1825 /* If \{ is a literal. */
1826 if (!(syntax & RE_INTERVALS)
1827 /* If we're at `\{' and it's not the open-interval
1828 operator. */
1829 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
1830 || (p - 2 == pattern && p == pend))
1831 goto normal_backslash;
1832
1833 handle_interval:
1834 {
1835 /* If got here, then the syntax allows intervals. */
1836
1837 /* At least (most) this many matches must be made. */
1838 int lower_bound = -1, upper_bound = -1;
1839
1840 beg_interval = p - 1;
1841
1842 if (p == pend)
1843 {
1844 if (syntax & RE_NO_BK_BRACES)
1845 goto unfetch_interval;
1846 else
1847 return REG_EBRACE;
1848 }
1849
1850 GET_UNSIGNED_NUMBER (lower_bound);
1851
1852 if (c == ',')
1853 {
1854 GET_UNSIGNED_NUMBER (upper_bound);
1855 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
1856 }
1857 else
1858 /* Interval such as `{1}' => match exactly once. */
1859 upper_bound = lower_bound;
1860
1861 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
1862 || lower_bound > upper_bound)
1863 {
1864 if (syntax & RE_NO_BK_BRACES)
1865 goto unfetch_interval;
1866 else
1867 return REG_BADBR;
1868 }
1869
1870 if (!(syntax & RE_NO_BK_BRACES))
1871 {
1872 if (c != '\\') return REG_EBRACE;
1873
1874 PATFETCH (c);
1875 }
1876
1877 if (c != '}')
1878 {
1879 if (syntax & RE_NO_BK_BRACES)
1880 goto unfetch_interval;
1881 else
1882 return REG_BADBR;
1883 }
1884
1885 /* We just parsed a valid interval. */
1886
1887 /* If it's invalid to have no preceding re. */
1888 if (!laststart)
1889 {
1890 if (syntax & RE_CONTEXT_INVALID_OPS)
1891 return REG_BADRPT;
1892 else if (syntax & RE_CONTEXT_INDEP_OPS)
1893 laststart = b;
1894 else
1895 goto unfetch_interval;
1896 }
1897
1898 /* If the upper bound is zero, don't want to succeed at
1899 all; jump from `laststart' to `b + 3', which will be
1900 the end of the buffer after we insert the jump. */
1901 if (upper_bound == 0)
1902 {
1903 GET_BUFFER_SPACE (3);
1904 INSERT_JUMP (jump, laststart, b + 3);
1905 b += 3;
1906 }
1907
1908 /* Otherwise, we have a nontrivial interval. When
1909 we're all done, the pattern will look like:
1910 set_number_at <jump count> <upper bound>
1911 set_number_at <succeed_n count> <lower bound>
1912 succeed_n <after jump addr> <succed_n count>
1913 <body of loop>
1914 jump_n <succeed_n addr> <jump count>
1915 (The upper bound and `jump_n' are omitted if
1916 `upper_bound' is 1, though.) */
1917 else
1918 { /* If the upper bound is > 1, we need to insert
1919 more at the end of the loop. */
1920 unsigned nbytes = 10 + (upper_bound > 1) * 10;
1921
1922 GET_BUFFER_SPACE (nbytes);
1923
1924 /* Initialize lower bound of the `succeed_n', even
1925 though it will be set during matching by its
1926 attendant `set_number_at' (inserted next),
1927 because `re_compile_fastmap' needs to know.
1928 Jump to the `jump_n' we might insert below. */
1929 INSERT_JUMP2 (succeed_n, laststart,
1930 b + 5 + (upper_bound > 1) * 5,
1931 lower_bound);
1932 b += 5;
1933
1934 /* Code to initialize the lower bound. Insert
1935 before the `succeed_n'. The `5' is the last two
1936 bytes of this `set_number_at', plus 3 bytes of
1937 the following `succeed_n'. */
1938 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
1939 b += 5;
1940
1941 if (upper_bound > 1)
1942 { /* More than one repetition is allowed, so
1943 append a backward jump to the `succeed_n'
1944 that starts this interval.
1945
1946 When we've reached this during matching,
1947 we'll have matched the interval once, so
1948 jump back only `upper_bound - 1' times. */
1949 STORE_JUMP2 (jump_n, b, laststart + 5,
1950 upper_bound - 1);
1951 b += 5;
1952
1953 /* The location we want to set is the second
1954 parameter of the `jump_n'; that is `b-2' as
1955 an absolute address. `laststart' will be
1956 the `set_number_at' we're about to insert;
1957 `laststart+3' the number to set, the source
1958 for the relative address. But we are
1959 inserting into the middle of the pattern --
1960 so everything is getting moved up by 5.
1961 Conclusion: (b - 2) - (laststart + 3) + 5,
1962 i.e., b - laststart.
1963
1964 We insert this at the beginning of the loop
1965 so that if we fail during matching, we'll
1966 reinitialize the bounds. */
1967 insert_op2 (set_number_at, laststart, b - laststart,
1968 upper_bound - 1, b);
1969 b += 5;
1970 }
1971 }
1972 pending_exact = 0;
1973 beg_interval = NULL;
1974 }
1975 break;
1976
1977 unfetch_interval:
1978 /* If an invalid interval, match the characters as literals. */
1979 assert (beg_interval);
1980 p = beg_interval;
1981 beg_interval = NULL;
1982
1983 /* normal_char and normal_backslash need `c'. */
1984 PATFETCH (c);
1985
1986 if (!(syntax & RE_NO_BK_BRACES))
1987 {
1988 if (p > pattern && p[-1] == '\\')
1989 goto normal_backslash;
1990 }
1991 goto normal_char;
1992
1993#ifdef emacs
1994 /* There is no way to specify the before_dot and after_dot
1995 operators. rms says this is ok. --karl */
1996 case '=':
1997 BUF_PUSH (at_dot);
1998 break;
1999
2000 case 's':
2001 laststart = b;
2002 PATFETCH (c);
2003 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2004 break;
2005
2006 case 'S':
2007 laststart = b;
2008 PATFETCH (c);
2009 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2010 break;
2011#endif /* emacs */
2012
2013
2014 case 'w':
2015 if (re_syntax_options & RE_NO_GNU_OPS)
2016 goto normal_char;
2017 laststart = b;
2018 BUF_PUSH (wordchar);
2019 break;
2020
2021
2022 case 'W':
2023 if (re_syntax_options & RE_NO_GNU_OPS)
2024 goto normal_char;
2025 laststart = b;
2026 BUF_PUSH (notwordchar);
2027 break;
2028
2029
2030 case '<':
2031 if (re_syntax_options & RE_NO_GNU_OPS)
2032 goto normal_char;
2033 BUF_PUSH (wordbeg);
2034 break;
2035
2036 case '>':
2037 if (re_syntax_options & RE_NO_GNU_OPS)
2038 goto normal_char;
2039 BUF_PUSH (wordend);
2040 break;
2041
2042 case 'b':
2043 if (re_syntax_options & RE_NO_GNU_OPS)
2044 goto normal_char;
2045 BUF_PUSH (wordbound);
2046 break;
2047
2048 case 'B':
2049 if (re_syntax_options & RE_NO_GNU_OPS)
2050 goto normal_char;
2051 BUF_PUSH (notwordbound);
2052 break;
2053
2054 case '`':
2055 if (re_syntax_options & RE_NO_GNU_OPS)
2056 goto normal_char;
2057 BUF_PUSH (begbuf);
2058 break;
2059
2060 case '\'':
2061 if (re_syntax_options & RE_NO_GNU_OPS)
2062 goto normal_char;
2063 BUF_PUSH (endbuf);
2064 break;
2065
2066 case '1': case '2': case '3': case '4': case '5':
2067 case '6': case '7': case '8': case '9':
2068 if (syntax & RE_NO_BK_REFS)
2069 goto normal_char;
2070
2071 c1 = c - '0';
2072
2073 if (c1 > regnum)
2074 return REG_ESUBREG;
2075
2076 /* Can't back reference to a subexpression if inside of it. */
2077 if (group_in_compile_stack (compile_stack, (regnum_t)c1))
2078 goto normal_char;
2079
2080 laststart = b;
2081 BUF_PUSH_2 (duplicate, c1);
2082 break;
2083
2084
2085 case '+':
2086 case '?':
2087 if (syntax & RE_BK_PLUS_QM)
2088 goto handle_plus;
2089 else
2090 goto normal_backslash;
2091
2092 default:
2093 normal_backslash:
2094 /* You might think it would be useful for \ to mean
2095 not to translate; but if we don't translate it
2096 it will never match anything. */
2097 c = TRANSLATE (c);
2098 goto normal_char;
2099 }
2100 break;
2101
2102
2103 default:
2104 /* Expects the character in `c'. */
2105 normal_char:
2106 /* If no exactn currently being built. */
2107 if (!pending_exact
2108
2109 /* If last exactn not at current position. */
2110 || pending_exact + *pending_exact + 1 != b
2111
2112 /* We have only one byte following the exactn for the count. */
2113 || *pending_exact == (1 << BYTEWIDTH) - 1
2114
2115 /* If followed by a repetition operator. */
2116 || *p == '*' || *p == '^'
2117 || ((syntax & RE_BK_PLUS_QM)
2118 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2119 : (*p == '+' || *p == '?'))
2120 || ((syntax & RE_INTERVALS)
2121 && ((syntax & RE_NO_BK_BRACES)
2122 ? *p == '{'
2123 : (p[0] == '\\' && p[1] == '{'))))
2124 {
2125 /* Start building a new exactn. */
2126
2127 laststart = b;
2128
2129 BUF_PUSH_2 (exactn, 0);
2130 pending_exact = b - 1;
2131 }
2132
2133 BUF_PUSH (c);
2134 (*pending_exact)++;
2135 break;
2136 } /* switch (c) */
2137 } /* while p != pend */
2138
2139
2140 /* Through the pattern now. */
2141
2142 if (fixup_alt_jump)
2143 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2144
2145 if (!COMPILE_STACK_EMPTY)
2146 return REG_EPAREN;
2147
2148 free (compile_stack.stack);
2149
2150 /* We have succeeded; set the length of the buffer. */
2151 bufp->used = b - bufp->buffer;
2152
2153#ifdef DEBUG
2154 if (debug)
2155 {
2156 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2157 print_compiled_pattern (bufp);
2158 }
2159#endif /* DEBUG */
2160
2161 return REG_NOERROR;
2162} /* regex_compile */
2163\f
2164/* Subroutines for `regex_compile'. */
2165
2166/* Store OP at LOC followed by two-byte integer parameter ARG. */
2167
2168static void
2169store_op1 (op, loc, arg)
2170 re_opcode_t op;
2171 unsigned char *loc;
2172 int arg;
2173{
2174 *loc = (unsigned char) op;
2175 STORE_NUMBER (loc + 1, arg);
2176}
2177
2178
2179/* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2180
2181static void
2182store_op2 (op, loc, arg1, arg2)
2183 re_opcode_t op;
2184 unsigned char *loc;
2185 int arg1, arg2;
2186{
2187 *loc = (unsigned char) op;
2188 STORE_NUMBER (loc + 1, arg1);
2189 STORE_NUMBER (loc + 3, arg2);
2190}
2191
2192
2193/* Copy the bytes from LOC to END to open up three bytes of space at LOC
2194 for OP followed by two-byte integer parameter ARG. */
2195
2196static void
2197insert_op1 (op, loc, arg, end)
2198 re_opcode_t op;
2199 unsigned char *loc;
2200 int arg;
2201 unsigned char *end;
2202{
2203 register unsigned char *pfrom = end;
2204 register unsigned char *pto = end + 3;
2205
2206 while (pfrom != loc)
2207 *--pto = *--pfrom;
2208
2209 store_op1 (op, loc, arg);
2210}
2211
2212
2213/* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2214
2215static void
2216insert_op2 (op, loc, arg1, arg2, end)
2217 re_opcode_t op;
2218 unsigned char *loc;
2219 int arg1, arg2;
2220 unsigned char *end;
2221{
2222 register unsigned char *pfrom = end;
2223 register unsigned char *pto = end + 5;
2224
2225 while (pfrom != loc)
2226 *--pto = *--pfrom;
2227
2228 store_op2 (op, loc, arg1, arg2);
2229}
2230
2231
2232/* P points to just after a ^ in PATTERN. Return true if that ^ comes
2233 after an alternative or a begin-subexpression. We assume there is at
2234 least one character before the ^. */
2235
2236static boolean
2237at_begline_loc_p (pattern, p, syntax)
2238 const char *pattern, *p;
2239 reg_syntax_t syntax;
2240{
2241 const char *prev = p - 2;
2242 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2243
2244 return
2245 /* After a subexpression? */
2246 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2247 /* After an alternative? */
2248 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2249}
2250
2251
2252/* The dual of at_begline_loc_p. This one is for $. We assume there is
2253 at least one character after the $, i.e., `P < PEND'. */
2254
2255static boolean
2256at_endline_loc_p (p, pend, syntax)
2257 const char *p, *pend;
2258 reg_syntax_t syntax;
2259{
2260 const char *next = p;
2261 boolean next_backslash = *next == '\\';
2262 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2263
2264 return
2265 /* Before a subexpression? */
2266 (syntax & RE_NO_BK_PARENS ? *next == ')'
2267 : next_backslash && next_next && *next_next == ')')
2268 /* Before an alternative? */
2269 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2270 : next_backslash && next_next && *next_next == '|');
2271}
2272
2273
2274/* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2275 false if it's not. */
2276
2277static boolean
2278group_in_compile_stack (compile_stack, regnum)
2279 compile_stack_type compile_stack;
2280 regnum_t regnum;
2281{
2282 int this_element;
2283
2284 for (this_element = compile_stack.avail - 1;
2285 this_element >= 0;
2286 this_element--)
2287 if (compile_stack.stack[this_element].regnum == regnum)
2288 return true;
2289
2290 return false;
2291}
2292
2293
2294/* Read the ending character of a range (in a bracket expression) from the
2295 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2296 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2297 Then we set the translation of all bits between the starting and
2298 ending characters (inclusive) in the compiled pattern B.
2299
2300 Return an error code.
2301
2302 We use these short variable names so we can use the same macros as
2303 `regex_compile' itself. */
2304
2305static reg_errcode_t
2306compile_range (p_ptr, pend, translate, syntax, b)
2307 const char **p_ptr, *pend;
2308 char *translate;
2309 reg_syntax_t syntax;
2310 unsigned char *b;
2311{
2312 unsigned this_char;
2313
2314 const char *p = *p_ptr;
2315 int range_start, range_end;
2316
2317 if (p == pend)
2318 return REG_ERANGE;
2319
2320 /* Even though the pattern is a signed `char *', we need to fetch
2321 with unsigned char *'s; if the high bit of the pattern character
2322 is set, the range endpoints will be negative if we fetch using a
2323 signed char *.
2324
2325 We also want to fetch the endpoints without translating them; the
2326 appropriate translation is done in the bit-setting loop below. */
2327 range_start = ((unsigned char *) p)[-2];
2328 range_end = ((unsigned char *) p)[0];
2329
2330 /* Have to increment the pointer into the pattern string, so the
2331 caller isn't still at the ending character. */
2332 (*p_ptr)++;
2333
2334 /* If the start is after the end, the range is empty. */
2335#ifdef __FreeBSD__
2336 if (collate_range_cmp (range_start, range_end) > 0)
2337#else
2338 if (range_start > range_end)
2339#endif
2340 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2341
2342#ifdef __FreeBSD__
2343 for (this_char = 0; this_char < 1 << BYTEWIDTH; this_char++)
2344 if ( collate_range_cmp (range_start, this_char) <= 0
2345 && collate_range_cmp (this_char, range_end) <= 0
2346 ) {
2347 SET_LIST_BIT (TRANSLATE (this_char));
2348 }
2349#else
2350 /* Here we see why `this_char' has to be larger than an `unsigned
2351 char' -- the range is inclusive, so if `range_end' == 0xff
2352 (assuming 8-bit characters), we would otherwise go into an infinite
2353 loop, since all characters <= 0xff. */
2354 for (this_char = range_start; this_char <= range_end; this_char++)
2355 {
2356 SET_LIST_BIT (TRANSLATE (this_char));
2357 }
2358#endif
2359 return REG_NOERROR;
2360}
2361\f
2362/* Failure stack declarations and macros; both re_compile_fastmap and
2363 re_match_2 use a failure stack. These have to be macros because of
2364 REGEX_ALLOCATE. */
2365
2366
2367/* Number of failure points for which to initially allocate space
2368 when matching. If this number is exceeded, we allocate more
2369 space, so it is not a hard limit. */
2370#ifndef INIT_FAILURE_ALLOC
2371#define INIT_FAILURE_ALLOC 5
2372#endif
2373
2374/* Roughly the maximum number of failure points on the stack. Would be
2375 exactly that if always used MAX_FAILURE_SPACE each time we failed.
2376 This is a variable only so users of regex can assign to it; we never
2377 change it ourselves. */
2378int re_max_failures = 2000;
2379
2380typedef const unsigned char *fail_stack_elt_t;
2381
2382typedef struct
2383{
2384 fail_stack_elt_t *stack;
2385 unsigned size;
2386 unsigned avail; /* Offset of next open position. */
2387} fail_stack_type;
2388
2389#define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
2390#define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
2391#define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
2392#define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail])
2393
2394
2395/* Initialize `fail_stack'. Do `return -2' if the alloc fails. */
2396
2397#define INIT_FAIL_STACK() \
2398 do { \
2399 fail_stack.stack = (fail_stack_elt_t *) \
2400 REGEX_ALLOCATE (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
2401 \
2402 if (fail_stack.stack == NULL) \
2403 return -2; \
2404 \
2405 fail_stack.size = INIT_FAILURE_ALLOC; \
2406 fail_stack.avail = 0; \
2407 } while (0)
2408
2409
2410/* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
2411
2412 Return 1 if succeeds, and 0 if either ran out of memory
2413 allocating space for it or it was already too large.
2414
2415 REGEX_REALLOCATE requires `destination' be declared. */
2416
2417#define DOUBLE_FAIL_STACK(fail_stack) \
2418 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
2419 ? 0 \
2420 : ((fail_stack).stack = (fail_stack_elt_t *) \
2421 REGEX_REALLOCATE ((fail_stack).stack, \
2422 (fail_stack).size * sizeof (fail_stack_elt_t), \
2423 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
2424 \
2425 (fail_stack).stack == NULL \
2426 ? 0 \
2427 : ((fail_stack).size <<= 1, \
2428 1)))
2429
2430
2431/* Push PATTERN_OP on FAIL_STACK.
2432
2433 Return 1 if was able to do so and 0 if ran out of memory allocating
2434 space to do so. */
2435#define PUSH_PATTERN_OP(pattern_op, fail_stack) \
2436 ((FAIL_STACK_FULL () \
2437 && !DOUBLE_FAIL_STACK (fail_stack)) \
2438 ? 0 \
2439 : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \
2440 1))
2441
2442/* This pushes an item onto the failure stack. Must be a four-byte
2443 value. Assumes the variable `fail_stack'. Probably should only
2444 be called from within `PUSH_FAILURE_POINT'. */
2445#define PUSH_FAILURE_ITEM(item) \
2446 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) item
2447
2448/* The complement operation. Assumes `fail_stack' is nonempty. */
2449#define POP_FAILURE_ITEM() fail_stack.stack[--fail_stack.avail]
2450
2451/* Used to omit pushing failure point id's when we're not debugging. */
2452#ifdef DEBUG
2453#define DEBUG_PUSH PUSH_FAILURE_ITEM
2454#define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_ITEM ()
2455#else
2456#define DEBUG_PUSH(item)
2457#define DEBUG_POP(item_addr)
2458#endif
2459
2460
2461/* Push the information about the state we will need
2462 if we ever fail back to it.
2463
2464 Requires variables fail_stack, regstart, regend, reg_info, and
2465 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
2466 declared.
2467
2468 Does `return FAILURE_CODE' if runs out of memory. */
2469
2470#define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
2471 do { \
2472 char *destination; \
2473 /* Must be int, so when we don't save any registers, the arithmetic \
2474 of 0 + -1 isn't done as unsigned. */ \
2475 /* Can't be int, since there is not a shred of a guarantee that int \
2476 is wide enough to hold a value of something to which pointer can \
2477 be assigned */ \
2478 s_reg_t this_reg; \
2479 \
2480 DEBUG_STATEMENT (failure_id++); \
2481 DEBUG_STATEMENT (nfailure_points_pushed++); \
2482 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
2483 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
2484 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
2485 \
2486 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
2487 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
2488 \
2489 /* Ensure we have enough space allocated for what we will push. */ \
2490 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
2491 { \
2492 if (!DOUBLE_FAIL_STACK (fail_stack)) \
2493 return failure_code; \
2494 \
2495 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
2496 (fail_stack).size); \
2497 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
2498 }
2499
2500#define PUSH_FAILURE_POINT2(pattern_place, string_place, failure_code) \
2501 /* Push the info, starting with the registers. */ \
2502 DEBUG_PRINT1 ("\n"); \
2503 \
2504 PUSH_FAILURE_POINT_LOOP (); \
2505 \
2506 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
2507 PUSH_FAILURE_ITEM (lowest_active_reg); \
2508 \
2509 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
2510 PUSH_FAILURE_ITEM (highest_active_reg); \
2511 \
2512 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
2513 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
2514 PUSH_FAILURE_ITEM (pattern_place); \
2515 \
2516 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
2517 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
2518 size2); \
2519 DEBUG_PRINT1 ("'\n"); \
2520 PUSH_FAILURE_ITEM (string_place); \
2521 \
2522 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
2523 DEBUG_PUSH (failure_id); \
2524 } while (0)
2525
2526/* Pulled out of PUSH_FAILURE_POINT() to shorten the definition
2527 of that macro. (for VAX C) */
2528#define PUSH_FAILURE_POINT_LOOP() \
2529 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
2530 this_reg++) \
2531 { \
2532 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
2533 DEBUG_STATEMENT (num_regs_pushed++); \
2534 \
2535 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2536 PUSH_FAILURE_ITEM (regstart[this_reg]); \
2537 \
2538 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2539 PUSH_FAILURE_ITEM (regend[this_reg]); \
2540 \
2541 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
2542 DEBUG_PRINT2 (" match_null=%d", \
2543 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
2544 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
2545 DEBUG_PRINT2 (" matched_something=%d", \
2546 MATCHED_SOMETHING (reg_info[this_reg])); \
2547 DEBUG_PRINT2 (" ever_matched=%d", \
2548 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
2549 DEBUG_PRINT1 ("\n"); \
2550 PUSH_FAILURE_ITEM (reg_info[this_reg].word); \
2551 }
2552
2553/* This is the number of items that are pushed and popped on the stack
2554 for each register. */
2555#define NUM_REG_ITEMS 3
2556
2557/* Individual items aside from the registers. */
2558#ifdef DEBUG
2559#define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
2560#else
2561#define NUM_NONREG_ITEMS 4
2562#endif
2563
2564/* We push at most this many items on the stack. */
2565#define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
2566
2567/* We actually push this many items. */
2568#define NUM_FAILURE_ITEMS \
2569 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
2570 + NUM_NONREG_ITEMS)
2571
2572/* How many items can still be added to the stack without overflowing it. */
2573#define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
2574
2575
2576/* Pops what PUSH_FAIL_STACK pushes.
2577
2578 We restore into the parameters, all of which should be lvalues:
2579 STR -- the saved data position.
2580 PAT -- the saved pattern position.
2581 LOW_REG, HIGH_REG -- the highest and lowest active registers.
2582 REGSTART, REGEND -- arrays of string positions.
2583 REG_INFO -- array of information about each subexpression.
2584
2585 Also assumes the variables `fail_stack' and (if debugging), `bufp',
2586 `pend', `string1', `size1', `string2', and `size2'. */
2587
2588#define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
2589{ \
2590 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
2591 s_reg_t this_reg; \
2592 const unsigned char *string_temp; \
2593 \
2594 assert (!FAIL_STACK_EMPTY ()); \
2595 \
2596 /* Remove failure points and point to how many regs pushed. */ \
2597 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
2598 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
2599 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
2600 \
2601 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
2602 \
2603 DEBUG_POP (&failure_id); \
2604 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
2605 \
2606 /* If the saved string location is NULL, it came from an \
2607 on_failure_keep_string_jump opcode, and we want to throw away the \
2608 saved NULL, thus retaining our current position in the string. */ \
2609 string_temp = POP_FAILURE_ITEM (); \
2610 if (string_temp != NULL) \
2611 str = (const char *) string_temp; \
2612 \
2613 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
2614 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
2615 DEBUG_PRINT1 ("'\n"); \
2616 \
2617 pat = (unsigned char *) POP_FAILURE_ITEM (); \
2618 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
2619 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
2620 \
2621 POP_FAILURE_POINT2 (low_reg, high_reg, regstart, regend, reg_info);
2622
2623/* Pulled out of POP_FAILURE_POINT() to shorten the definition
2624 of that macro. (for MSC 5.1) */
2625#define POP_FAILURE_POINT2(low_reg, high_reg, regstart, regend, reg_info) \
2626 \
2627 /* Restore register info. */ \
2628 high_reg = (active_reg_t) POP_FAILURE_ITEM (); \
2629 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
2630 \
2631 low_reg = (active_reg_t) POP_FAILURE_ITEM (); \
2632 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
2633 \
2634 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
2635 { \
2636 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
2637 \
2638 reg_info[this_reg].word = POP_FAILURE_ITEM (); \
2639 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
2640 \
2641 regend[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2642 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2643 \
2644 regstart[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2645 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2646 } \
2647 \
2648 DEBUG_STATEMENT (nfailure_points_popped++); \
2649} /* POP_FAILURE_POINT */
2650
2651\f
2652/* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2653 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2654 characters can start a string that matches the pattern. This fastmap
2655 is used by re_search to skip quickly over impossible starting points.
2656
2657 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2658 area as BUFP->fastmap.
2659
2660 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2661 the pattern buffer.
2662
2663 Returns 0 if we succeed, -2 if an internal error. */
2664
2665int
2666re_compile_fastmap (bufp)
2667 struct re_pattern_buffer *bufp;
2668{
2669 int j, k;
2670 fail_stack_type fail_stack;
2671#ifndef REGEX_MALLOC
2672 char *destination;
2673#endif
2674 /* We don't push any register information onto the failure stack. */
2675 unsigned num_regs = 0;
2676
2677 register char *fastmap = bufp->fastmap;
2678 unsigned char *pattern = bufp->buffer;
2679 const unsigned char *p = pattern;
2680 register unsigned char *pend = pattern + bufp->used;
2681
2682 /* Assume that each path through the pattern can be null until
2683 proven otherwise. We set this false at the bottom of switch
2684 statement, to which we get only if a particular path doesn't
2685 match the empty string. */
2686 boolean path_can_be_null = true;
2687
2688 /* We aren't doing a `succeed_n' to begin with. */
2689 boolean succeed_n_p = false;
2690
2691 assert (fastmap != NULL && p != NULL);
2692
2693 INIT_FAIL_STACK ();
2694 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2695 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2696 bufp->can_be_null = 0;
2697
2698 while (p != pend || !FAIL_STACK_EMPTY ())
2699 {
2700 if (p == pend)
2701 {
2702 bufp->can_be_null |= path_can_be_null;
2703
2704 /* Reset for next path. */
2705 path_can_be_null = true;
2706
2707 p = fail_stack.stack[--fail_stack.avail];
2708 }
2709
2710 /* We should never be about to go beyond the end of the pattern. */
2711 assert (p < pend);
2712
2713#ifdef SWITCH_ENUM_BUG
2714 switch ((int) ((re_opcode_t) *p++))
2715#else
2716 switch ((re_opcode_t) *p++)
2717#endif
2718 {
2719
2720 /* I guess the idea here is to simply not bother with a fastmap
2721 if a backreference is used, since it's too hard to figure out
2722 the fastmap for the corresponding group. Setting
2723 `can_be_null' stops `re_search_2' from using the fastmap, so
2724 that is all we do. */
2725 case duplicate:
2726 bufp->can_be_null = 1;
2727 return 0;
2728
2729
2730 /* Following are the cases which match a character. These end
2731 with `break'. */
2732
2733 case exactn:
2734 fastmap[p[1]] = 1;
2735 break;
2736
2737
2738 case charset:
2739 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2740 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2741 fastmap[j] = 1;
2742 break;
2743
2744
2745 case charset_not:
2746 /* Chars beyond end of map must be allowed. */
2747 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2748 fastmap[j] = 1;
2749
2750 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2751 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2752 fastmap[j] = 1;
2753 break;
2754
2755
2756 case wordchar:
2757 for (j = 0; j < (1 << BYTEWIDTH); j++)
2758 if (SYNTAX (j) == Sword)
2759 fastmap[j] = 1;
2760 break;
2761
2762
2763 case notwordchar:
2764 for (j = 0; j < (1 << BYTEWIDTH); j++)
2765 if (SYNTAX (j) != Sword)
2766 fastmap[j] = 1;
2767 break;
2768
2769
2770 case anychar:
2771 /* `.' matches anything ... */
2772 for (j = 0; j < (1 << BYTEWIDTH); j++)
2773 fastmap[j] = 1;
2774
2775 /* ... except perhaps newline. */
2776 if (!(bufp->syntax & RE_DOT_NEWLINE))
2777 fastmap['\n'] = 0;
2778
2779 /* Return if we have already set `can_be_null'; if we have,
2780 then the fastmap is irrelevant. Something's wrong here. */
2781 else if (bufp->can_be_null)
2782 return 0;
2783
2784 /* Otherwise, have to check alternative paths. */
2785 break;
2786
2787
2788#ifdef emacs
2789 case syntaxspec:
2790 k = *p++;
2791 for (j = 0; j < (1 << BYTEWIDTH); j++)
2792 if (SYNTAX (j) == (enum syntaxcode) k)
2793 fastmap[j] = 1;
2794 break;
2795
2796
2797 case notsyntaxspec:
2798 k = *p++;
2799 for (j = 0; j < (1 << BYTEWIDTH); j++)
2800 if (SYNTAX (j) != (enum syntaxcode) k)
2801 fastmap[j] = 1;
2802 break;
2803
2804
2805 /* All cases after this match the empty string. These end with
2806 `continue'. */
2807
2808
2809 case before_dot:
2810 case at_dot:
2811 case after_dot:
2812 continue;
2813#endif /* not emacs */
2814
2815
2816 case no_op:
2817 case begline:
2818 case endline:
2819 case begbuf:
2820 case endbuf:
2821 case wordbound:
2822 case notwordbound:
2823 case wordbeg:
2824 case wordend:
2825 case push_dummy_failure:
2826 continue;
2827
2828
2829 case jump_n:
2830 case pop_failure_jump:
2831 case maybe_pop_jump:
2832 case jump:
2833 case jump_past_alt:
2834 case dummy_failure_jump:
2835 EXTRACT_NUMBER_AND_INCR (j, p);
2836 p += j;
2837 if (j > 0)
2838 continue;
2839
2840 /* Jump backward implies we just went through the body of a
2841 loop and matched nothing. Opcode jumped to should be
2842 `on_failure_jump' or `succeed_n'. Just treat it like an
2843 ordinary jump. For a * loop, it has pushed its failure
2844 point already; if so, discard that as redundant. */
2845 if ((re_opcode_t) *p != on_failure_jump
2846 && (re_opcode_t) *p != succeed_n)
2847 continue;
2848
2849 p++;
2850 EXTRACT_NUMBER_AND_INCR (j, p);
2851 p += j;
2852
2853 /* If what's on the stack is where we are now, pop it. */
2854 if (!FAIL_STACK_EMPTY ()
2855 && fail_stack.stack[fail_stack.avail - 1] == p)
2856 fail_stack.avail--;
2857
2858 continue;
2859
2860
2861 case on_failure_jump:
2862 case on_failure_keep_string_jump:
2863 handle_on_failure_jump:
2864 EXTRACT_NUMBER_AND_INCR (j, p);
2865
2866 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
2867 end of the pattern. We don't want to push such a point,
2868 since when we restore it above, entering the switch will
2869 increment `p' past the end of the pattern. We don't need
2870 to push such a point since we obviously won't find any more
2871 fastmap entries beyond `pend'. Such a pattern can match
2872 the null string, though. */
2873 if (p + j < pend)
2874 {
2875 if (!PUSH_PATTERN_OP (p + j, fail_stack))
2876 return -2;
2877 }
2878 else
2879 bufp->can_be_null = 1;
2880
2881 if (succeed_n_p)
2882 {
2883 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
2884 succeed_n_p = false;
2885 }
2886
2887 continue;
2888
2889
2890 case succeed_n:
2891 /* Get to the number of times to succeed. */
2892 p += 2;
2893
2894 /* Increment p past the n for when k != 0. */
2895 EXTRACT_NUMBER_AND_INCR (k, p);
2896 if (k == 0)
2897 {
2898 p -= 4;
2899 succeed_n_p = true; /* Spaghetti code alert. */
2900 goto handle_on_failure_jump;
2901 }
2902 continue;
2903
2904
2905 case set_number_at:
2906 p += 4;
2907 continue;
2908
2909
2910 case start_memory:
2911 case stop_memory:
2912 p += 2;
2913 continue;
2914
2915
2916 default:
2917 abort (); /* We have listed all the cases. */
2918 } /* switch *p++ */
2919
2920 /* Getting here means we have found the possible starting
2921 characters for one path of the pattern -- and that the empty
2922 string does not match. We need not follow this path further.
2923 Instead, look at the next alternative (remembered on the
2924 stack), or quit if no more. The test at the top of the loop
2925 does these things. */
2926 path_can_be_null = false;
2927 p = pend;
2928 } /* while p */
2929
2930 /* Set `can_be_null' for the last path (also the first path, if the
2931 pattern is empty). */
2932 bufp->can_be_null |= path_can_be_null;
2933 return 0;
2934} /* re_compile_fastmap */
2935\f
2936/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
2937 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
2938 this memory for recording register information. STARTS and ENDS
2939 must be allocated using the malloc library routine, and must each
2940 be at least NUM_REGS * sizeof (regoff_t) bytes long.
2941
2942 If NUM_REGS == 0, then subsequent matches should allocate their own
2943 register data.
2944
2945 Unless this function is called, the first search or match using
2946 PATTERN_BUFFER will allocate its own register data, without
2947 freeing the old data. */
2948
2949void
2950re_set_registers (bufp, regs, num_regs, starts, ends)
2951 struct re_pattern_buffer *bufp;
2952 struct re_registers *regs;
2953 unsigned num_regs;
2954 regoff_t *starts, *ends;
2955{
2956 if (num_regs)
2957 {
2958 bufp->regs_allocated = REGS_REALLOCATE;
2959 regs->num_regs = num_regs;
2960 regs->start = starts;
2961 regs->end = ends;
2962 }
2963 else
2964 {
2965 bufp->regs_allocated = REGS_UNALLOCATED;
2966 regs->num_regs = 0;
2967 regs->start = regs->end = 0;
2968 }
2969}
2970\f
2971/* Searching routines. */
2972
2973/* Like re_search_2, below, but only one string is specified, and
2974 doesn't let you say where to stop matching. */
2975
2976int
2977re_search (bufp, string, size, startpos, range, regs)
2978 struct re_pattern_buffer *bufp;
2979 const char *string;
2980 int size, startpos, range;
2981 struct re_registers *regs;
2982{
2983 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
2984 regs, size);
2985}
2986
2987
2988/* Using the compiled pattern in BUFP->buffer, first tries to match the
2989 virtual concatenation of STRING1 and STRING2, starting first at index
2990 STARTPOS, then at STARTPOS + 1, and so on.
2991
2992 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
2993
2994 RANGE is how far to scan while trying to match. RANGE = 0 means try
2995 only at STARTPOS; in general, the last start tried is STARTPOS +
2996 RANGE.
2997
2998 In REGS, return the indices of the virtual concatenation of STRING1
2999 and STRING2 that matched the entire BUFP->buffer and its contained
3000 subexpressions.
3001
3002 Do not consider matching one past the index STOP in the virtual
3003 concatenation of STRING1 and STRING2.
3004
3005 We return either the position in the strings at which the match was
3006 found, -1 if no match, or -2 if error (such as failure
3007 stack overflow). */
3008
3009int
3010re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3011 struct re_pattern_buffer *bufp;
3012 const char *string1, *string2;
3013 int size1, size2;
3014 int startpos;
3015 int range;
3016 struct re_registers *regs;
3017 int stop;
3018{
3019 int val;
3020 register char *fastmap = bufp->fastmap;
3021 register char *translate = bufp->translate;
3022 int total_size = size1 + size2;
3023 int endpos = startpos + range;
3024
3025 /* Check for out-of-range STARTPOS. */
3026 if (startpos < 0 || startpos > total_size)
3027 return -1;
3028
3029 /* Fix up RANGE if it might eventually take us outside
3030 the virtual concatenation of STRING1 and STRING2. */
3031 if (endpos < -1)
3032 range = -1 - startpos;
3033 else if (endpos > total_size)
3034 range = total_size - startpos;
3035
3036 /* If the search isn't to be a backwards one, don't waste time in a
3037 search for a pattern that must be anchored. */
3038 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3039 {
3040 if (startpos > 0)
3041 return -1;
3042 else
3043 range = 1;
3044 }
3045
3046 /* Update the fastmap now if not correct already. */
3047 if (fastmap && !bufp->fastmap_accurate)
3048 if (re_compile_fastmap (bufp) == -2)
3049 return -2;
3050
3051 /* Loop through the string, looking for a place to start matching. */
3052 for (;;)
3053 {
3054 /* If a fastmap is supplied, skip quickly over characters that
3055 cannot be the start of a match. If the pattern can match the
3056 null string, however, we don't need to skip characters; we want
3057 the first null string. */
3058 if (fastmap && startpos < total_size && !bufp->can_be_null)
3059 {
3060 if (range > 0) /* Searching forwards. */
3061 {
3062 register const char *d;
3063 register int lim = 0;
3064 int irange = range;
3065
3066 if (startpos < size1 && startpos + range >= size1)
3067 lim = range - (size1 - startpos);
3068
3069 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3070
3071 /* Written out as an if-else to avoid testing `translate'
3072 inside the loop. */
3073 if (translate)
3074 while (range > lim
3075 && !fastmap[(unsigned char)
3076 translate[(unsigned char) *d++]])
3077 range--;
3078 else
3079 while (range > lim && !fastmap[(unsigned char) *d++])
3080 range--;
3081
3082 startpos += irange - range;
3083 }
3084 else /* Searching backwards. */
3085 {
3086 register char c = (size1 == 0 || startpos >= size1
3087 ? string2[startpos - size1]
3088 : string1[startpos]);
3089
3090 if (!fastmap[(unsigned char) TRANSLATE (c)])
3091 goto advance;
3092 }
3093 }
3094
3095 /* If can't match the null string, and that's all we have left, fail. */
3096 if (range >= 0 && startpos == total_size && fastmap
3097 && !bufp->can_be_null)
3098 return -1;
3099
3100 val = re_match_2 (bufp, string1, size1, string2, size2,
3101 startpos, regs, stop);
3102 if (val >= 0)
3103 return startpos;
3104
3105 if (val == -2)
3106 return -2;
3107
3108 advance:
3109 if (!range)
3110 break;
3111 else if (range > 0)
3112 {
3113 range--;
3114 startpos++;
3115 }
3116 else
3117 {
3118 range++;
3119 startpos--;
3120 }
3121 }
3122 return -1;
3123} /* re_search_2 */
3124\f
3125/* Structure for per-register (a.k.a. per-group) information.
3126 This must not be longer than one word, because we push this value
3127 onto the failure stack. Other register information, such as the
3128 starting and ending positions (which are addresses), and the list of
3129 inner groups (which is a bits list) are maintained in separate
3130 variables.
3131
3132 We are making a (strictly speaking) nonportable assumption here: that
3133 the compiler will pack our bit fields into something that fits into
3134 the type of `word', i.e., is something that fits into one item on the
3135 failure stack. */
3136
3137/* Declarations and macros for re_match_2. */
3138
3139typedef union
3140{
3141 fail_stack_elt_t word;
3142 struct
3143 {
3144 /* This field is one if this group can match the empty string,
3145 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
3146#define MATCH_NULL_UNSET_VALUE 3
3147 unsigned match_null_string_p : 2;
3148 unsigned is_active : 1;
3149 unsigned matched_something : 1;
3150 unsigned ever_matched_something : 1;
3151 } bits;
3152} register_info_type;
3153
3154#define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
3155#define IS_ACTIVE(R) ((R).bits.is_active)
3156#define MATCHED_SOMETHING(R) ((R).bits.matched_something)
3157#define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
3158
3159static boolean group_match_null_string_p _RE_ARGS((unsigned char **p,
3160 unsigned char *end,
3161 register_info_type *reg_info));
3162static boolean alt_match_null_string_p _RE_ARGS((unsigned char *p,
3163 unsigned char *end,
3164 register_info_type *reg_info));
3165static boolean common_op_match_null_string_p _RE_ARGS((unsigned char **p,
3166 unsigned char *end,
3167 register_info_type *reg_info));
3168static int bcmp_translate _RE_ARGS((const char *s1, const char *s2,
3169 int len, char *translate));
3170
3171/* Call this when have matched a real character; it sets `matched' flags
3172 for the subexpressions which we are currently inside. Also records
3173 that those subexprs have matched. */
3174#define SET_REGS_MATCHED() \
3175 do \
3176 { \
3177 active_reg_t r; \
3178 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
3179 { \
3180 MATCHED_SOMETHING (reg_info[r]) \
3181 = EVER_MATCHED_SOMETHING (reg_info[r]) \
3182 = 1; \
3183 } \
3184 } \
3185 while (0)
3186
3187
3188/* This converts PTR, a pointer into one of the search strings `string1'
3189 and `string2' into an offset from the beginning of that string. */
3190#define POINTER_TO_OFFSET(ptr) \
3191 (FIRST_STRING_P (ptr) ? (ptr) - string1 : (ptr) - string2 + size1)
3192
3193/* Registers are set to a sentinel when they haven't yet matched. */
3194#define REG_UNSET_VALUE ((char *) -1)
3195#define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
3196
3197
3198/* Macros for dealing with the split strings in re_match_2. */
3199
3200#define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3201
3202/* Call before fetching a character with *d. This switches over to
3203 string2 if necessary. */
3204#define PREFETCH() \
3205 while (d == dend) \
3206 { \
3207 /* End of string2 => fail. */ \
3208 if (dend == end_match_2) \
3209 goto fail; \
3210 /* End of string1 => advance to string2. */ \
3211 d = string2; \
3212 dend = end_match_2; \
3213 }
3214
3215
3216/* Test if at very beginning or at very end of the virtual concatenation
3217 of `string1' and `string2'. If only one string, it's `string2'. */
3218#define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3219#define AT_STRINGS_END(d) ((d) == end2)
3220
3221
3222/* Test if D points to a character which is word-constituent. We have
3223 two special cases to check for: if past the end of string1, look at
3224 the first character in string2; and if before the beginning of
3225 string2, look at the last character in string1. */
3226#define WORDCHAR_P(d) \
3227 (SYNTAX ((d) == end1 ? *string2 \
3228 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3229 == Sword)
3230
3231/* Test if the character before D and the one at D differ with respect
3232 to being word-constituent. */
3233#define AT_WORD_BOUNDARY(d) \
3234 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3235 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3236
3237
3238/* Free everything we malloc. */
3239#ifdef REGEX_MALLOC
3240#define FREE_VAR(var) if (var) free (var); var = NULL
3241#define FREE_VARIABLES() \
3242 do { \
3243 FREE_VAR (fail_stack.stack); \
3244 FREE_VAR (regstart); \
3245 FREE_VAR (regend); \
3246 FREE_VAR (old_regstart); \
3247 FREE_VAR (old_regend); \
3248 FREE_VAR (best_regstart); \
3249 FREE_VAR (best_regend); \
3250 FREE_VAR (reg_info); \
3251 FREE_VAR (reg_dummy); \
3252 FREE_VAR (reg_info_dummy); \
3253 } while (0)
3254#else /* not REGEX_MALLOC */
3255/* Some MIPS systems (at least) want this to free alloca'd storage. */
3256#define FREE_VARIABLES() alloca (0)
3257#endif /* not REGEX_MALLOC */
3258
3259
3260/* These values must meet several constraints. They must not be valid
3261 register values; since we have a limit of 255 registers (because
3262 we use only one byte in the pattern for the register number), we can
3263 use numbers larger than 255. They must differ by 1, because of
3264 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3265 be larger than the value for the highest register, so we do not try
3266 to actually save any registers when none are active. */
3267#define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3268#define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3269\f
3270/* Matching routines. */
3271
3272#ifndef emacs /* Emacs never uses this. */
3273/* re_match is like re_match_2 except it takes only a single string. */
3274
3275int
3276re_match (bufp, string, size, pos, regs)
3277 struct re_pattern_buffer *bufp;
3278 const char *string;
3279 int size, pos;
3280 struct re_registers *regs;
3281 {
3282 return re_match_2 (bufp, NULL, 0, string, size, pos, regs, size);
3283}
3284#endif /* not emacs */
3285
3286
3287/* re_match_2 matches the compiled pattern in BUFP against the
3288 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3289 and SIZE2, respectively). We start matching at POS, and stop
3290 matching at STOP.
3291
3292 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3293 store offsets for the substring each group matched in REGS. See the
3294 documentation for exactly how many groups we fill.
3295
3296 We return -1 if no match, -2 if an internal error (such as the
3297 failure stack overflowing). Otherwise, we return the length of the
3298 matched substring. */
3299
3300int
3301re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3302 struct re_pattern_buffer *bufp;
3303 const char *string1, *string2;
3304 int size1, size2;
3305 int pos;
3306 struct re_registers *regs;
3307 int stop;
3308{
3309 /* General temporaries. */
3310 int mcnt;
3311 unsigned char *p1;
3312
3313 /* Just past the end of the corresponding string. */
3314 const char *end1, *end2;
3315
3316 /* Pointers into string1 and string2, just past the last characters in
3317 each to consider matching. */
3318 const char *end_match_1, *end_match_2;
3319
3320 /* Where we are in the data, and the end of the current string. */
3321 const char *d, *dend;
3322
3323 /* Where we are in the pattern, and the end of the pattern. */
3324 unsigned char *p = bufp->buffer;
3325 register unsigned char *pend = p + bufp->used;
3326
3327 /* We use this to map every character in the string. */
3328 char *translate = bufp->translate;
3329
3330 /* Failure point stack. Each place that can handle a failure further
3331 down the line pushes a failure point on this stack. It consists of
3332 restart, regend, and reg_info for all registers corresponding to
3333 the subexpressions we're currently inside, plus the number of such
3334 registers, and, finally, two char *'s. The first char * is where
3335 to resume scanning the pattern; the second one is where to resume
3336 scanning the strings. If the latter is zero, the failure point is
3337 a ``dummy''; if a failure happens and the failure point is a dummy,
3338 it gets discarded and the next next one is tried. */
3339 fail_stack_type fail_stack;
3340#ifdef DEBUG
3341 static unsigned failure_id = 0;
3342 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3343#endif
3344
3345 /* We fill all the registers internally, independent of what we
3346 return, for use in backreferences. The number here includes
3347 an element for register zero. */
3348 size_t num_regs = bufp->re_nsub + 1;
3349
3350 /* The currently active registers. */
3351 active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3352 active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3353
3354 /* Information on the contents of registers. These are pointers into
3355 the input strings; they record just what was matched (on this
3356 attempt) by a subexpression part of the pattern, that is, the
3357 regnum-th regstart pointer points to where in the pattern we began
3358 matching and the regnum-th regend points to right after where we
3359 stopped matching the regnum-th subexpression. (The zeroth register
3360 keeps track of what the whole pattern matches.) */
3361 const char **regstart = 0, **regend = 0;
3362
3363 /* If a group that's operated upon by a repetition operator fails to
3364 match anything, then the register for its start will need to be
3365 restored because it will have been set to wherever in the string we
3366 are when we last see its open-group operator. Similarly for a
3367 register's end. */
3368 const char **old_regstart = 0, **old_regend = 0;
3369
3370 /* The is_active field of reg_info helps us keep track of which (possibly
3371 nested) subexpressions we are currently in. The matched_something
3372 field of reg_info[reg_num] helps us tell whether or not we have
3373 matched any of the pattern so far this time through the reg_num-th
3374 subexpression. These two fields get reset each time through any
3375 loop their register is in. */
3376 register_info_type *reg_info = 0;
3377
3378 /* The following record the register info as found in the above
3379 variables when we find a match better than any we've seen before.
3380 This happens as we backtrack through the failure points, which in
3381 turn happens only if we have not yet matched the entire string. */
3382 unsigned best_regs_set = false;
3383 const char **best_regstart = 0, **best_regend = 0;
3384
3385 /* Logically, this is `best_regend[0]'. But we don't want to have to
3386 allocate space for that if we're not allocating space for anything
3387 else (see below). Also, we never need info about register 0 for
3388 any of the other register vectors, and it seems rather a kludge to
3389 treat `best_regend' differently than the rest. So we keep track of
3390 the end of the best match so far in a separate variable. We
3391 initialize this to NULL so that when we backtrack the first time
3392 and need to test it, it's not garbage. */
3393 const char *match_end = NULL;
3394
3395 /* Used when we pop values we don't care about. */
3396 const char **reg_dummy = 0;
3397 register_info_type *reg_info_dummy = 0;
3398
3399#ifdef DEBUG
3400 /* Counts the total number of registers pushed. */
3401 unsigned num_regs_pushed = 0;
3402#endif
3403
3404 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3405
3406 INIT_FAIL_STACK ();
3407
3408 /* Do not bother to initialize all the register variables if there are
3409 no groups in the pattern, as it takes a fair amount of time. If
3410 there are groups, we include space for register 0 (the whole
3411 pattern), even though we never use it, since it simplifies the
3412 array indexing. We should fix this. */
3413 if (bufp->re_nsub)
3414 {
3415 regstart = REGEX_TALLOC (num_regs, const char *);
3416 regend = REGEX_TALLOC (num_regs, const char *);
3417 old_regstart = REGEX_TALLOC (num_regs, const char *);
3418 old_regend = REGEX_TALLOC (num_regs, const char *);
3419 best_regstart = REGEX_TALLOC (num_regs, const char *);
3420 best_regend = REGEX_TALLOC (num_regs, const char *);
3421 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3422 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3423 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3424
3425 if (!(regstart && regend && old_regstart && old_regend && reg_info
3426 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3427 {
3428 FREE_VARIABLES ();
3429 return -2;
3430 }
3431 }
3432#ifdef REGEX_MALLOC
3433 else
3434 {
3435 /* We must initialize all our variables to NULL, so that
3436 `FREE_VARIABLES' doesn't try to free them. */
3437 regstart = regend = old_regstart = old_regend = best_regstart
3438 = best_regend = reg_dummy = NULL;
3439 reg_info = reg_info_dummy = (register_info_type *) NULL;
3440 }
3441#endif /* REGEX_MALLOC */
3442
3443 /* The starting position is bogus. */
3444 if (pos < 0 || pos > size1 + size2)
3445 {
3446 FREE_VARIABLES ();
3447 return -1;
3448 }
3449
3450 /* Initialize subexpression text positions to -1 to mark ones that no
3451 start_memory/stop_memory has been seen for. Also initialize the
3452 register information struct. */
3453 for (mcnt = 1; mcnt < num_regs; mcnt++)
3454 {
3455 regstart[mcnt] = regend[mcnt]
3456 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3457
3458 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3459 IS_ACTIVE (reg_info[mcnt]) = 0;
3460 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3461 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3462 }
3463
3464 /* We move `string1' into `string2' if the latter's empty -- but not if
3465 `string1' is null. */
3466 if (size2 == 0 && string1 != NULL)
3467 {
3468 string2 = string1;
3469 size2 = size1;
3470 string1 = 0;
3471 size1 = 0;
3472 }
3473 end1 = string1 + size1;
3474 end2 = string2 + size2;
3475
3476 /* Compute where to stop matching, within the two strings. */
3477 if (stop <= size1)
3478 {
3479 end_match_1 = string1 + stop;
3480 end_match_2 = string2;
3481 }
3482 else
3483 {
3484 end_match_1 = end1;
3485 end_match_2 = string2 + stop - size1;
3486 }
3487
3488 /* `p' scans through the pattern as `d' scans through the data.
3489 `dend' is the end of the input string that `d' points within. `d'
3490 is advanced into the following input string whenever necessary, but
3491 this happens before fetching; therefore, at the beginning of the
3492 loop, `d' can be pointing at the end of a string, but it cannot
3493 equal `string2'. */
3494 if (size1 > 0 && pos <= size1)
3495 {
3496 d = string1 + pos;
3497 dend = end_match_1;
3498 }
3499 else
3500 {
3501 d = string2 + pos - size1;
3502 dend = end_match_2;
3503 }
3504
3505 DEBUG_PRINT1 ("The compiled pattern is: ");
3506 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3507 DEBUG_PRINT1 ("The string to match is: `");
3508 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3509 DEBUG_PRINT1 ("'\n");
3510
3511 /* This loops over pattern commands. It exits by returning from the
3512 function if the match is complete, or it drops through if the match
3513 fails at this starting point in the input data. */
3514 for (;;)
3515 {
3516 DEBUG_PRINT2 ("\n0x%x: ", p);
3517
3518 if (p == pend)
3519 { /* End of pattern means we might have succeeded. */
3520 DEBUG_PRINT1 ("end of pattern ... ");
3521
3522 /* If we haven't matched the entire string, and we want the
3523 longest match, try backtracking. */
3524 if (d != end_match_2)
3525 {
3526 DEBUG_PRINT1 ("backtracking.\n");
3527
3528 if (!FAIL_STACK_EMPTY ())
3529 { /* More failure points to try. */
3530 boolean same_str_p = (FIRST_STRING_P (match_end)
3531 == MATCHING_IN_FIRST_STRING);
3532
3533 /* If exceeds best match so far, save it. */
3534 if (!best_regs_set
3535 || (same_str_p && d > match_end)
3536 || (!same_str_p && !MATCHING_IN_FIRST_STRING))
3537 {
3538 best_regs_set = true;
3539 match_end = d;
3540
3541 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3542
3543 for (mcnt = 1; mcnt < num_regs; mcnt++)
3544 {
3545 best_regstart[mcnt] = regstart[mcnt];
3546 best_regend[mcnt] = regend[mcnt];
3547 }
3548 }
3549 goto fail;
3550 }
3551
3552 /* If no failure points, don't restore garbage. */
3553 else if (best_regs_set)
3554 {
3555 restore_best_regs:
3556 /* Restore best match. It may happen that `dend ==
3557 end_match_1' while the restored d is in string2.
3558 For example, the pattern `x.*y.*z' against the
3559 strings `x-' and `y-z-', if the two strings are
3560 not consecutive in memory. */
3561 DEBUG_PRINT1 ("Restoring best registers.\n");
3562
3563 d = match_end;
3564 dend = ((d >= string1 && d <= end1)
3565 ? end_match_1 : end_match_2);
3566
3567 for (mcnt = 1; mcnt < num_regs; mcnt++)
3568 {
3569 regstart[mcnt] = best_regstart[mcnt];
3570 regend[mcnt] = best_regend[mcnt];
3571 }
3572 }
3573 } /* d != end_match_2 */
3574
3575 DEBUG_PRINT1 ("Accepting match.\n");
3576
3577 /* If caller wants register contents data back, do it. */
3578 if (regs && !bufp->no_sub)
3579 {
3580 /* Have the register data arrays been allocated? */
3581 if (bufp->regs_allocated == REGS_UNALLOCATED)
3582 { /* No. So allocate them with malloc. We need one
3583 extra element beyond `num_regs' for the `-1' marker
3584 GNU code uses. */
3585 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3586 regs->start = TALLOC (regs->num_regs, regoff_t);
3587 regs->end = TALLOC (regs->num_regs, regoff_t);
3588 if (regs->start == NULL || regs->end == NULL)
3589 return -2;
3590 bufp->regs_allocated = REGS_REALLOCATE;
3591 }
3592 else if (bufp->regs_allocated == REGS_REALLOCATE)
3593 { /* Yes. If we need more elements than were already
3594 allocated, reallocate them. If we need fewer, just
3595 leave it alone. */
3596 if (regs->num_regs < num_regs + 1)
3597 {
3598 regs->num_regs = num_regs + 1;
3599 RETALLOC (regs->start, regs->num_regs, regoff_t);
3600 RETALLOC (regs->end, regs->num_regs, regoff_t);
3601 if (regs->start == NULL || regs->end == NULL)
3602 return -2;
3603 }
3604 }
3605 else
3606 {
3607 /* These braces fend off a "empty body in an else-statement"
3608 warning under GCC when assert expands to nothing. */
3609 assert (bufp->regs_allocated == REGS_FIXED);
3610 }
3611
3612 /* Convert the pointer data in `regstart' and `regend' to
3613 indices. Register zero has to be set differently,
3614 since we haven't kept track of any info for it. */
3615 if (regs->num_regs > 0)
3616 {
3617 regs->start[0] = pos;
3618 regs->end[0] = (MATCHING_IN_FIRST_STRING ? d - string1
3619 : d - string2 + size1);
3620 }
3621
3622 /* Go through the first `min (num_regs, regs->num_regs)'
3623 registers, since that is all we initialized. */
3624 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3625 {
3626 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3627 regs->start[mcnt] = regs->end[mcnt] = -1;
3628 else
3629 {
3630 regs->start[mcnt] = POINTER_TO_OFFSET (regstart[mcnt]);
3631 regs->end[mcnt] = POINTER_TO_OFFSET (regend[mcnt]);
3632 }
3633 }
3634
3635 /* If the regs structure we return has more elements than
3636 were in the pattern, set the extra elements to -1. If
3637 we (re)allocated the registers, this is the case,
3638 because we always allocate enough to have at least one
3639 -1 at the end. */
3640 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3641 regs->start[mcnt] = regs->end[mcnt] = -1;
3642 } /* regs && !bufp->no_sub */
3643
3644 FREE_VARIABLES ();
3645 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3646 nfailure_points_pushed, nfailure_points_popped,
3647 nfailure_points_pushed - nfailure_points_popped);
3648 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3649
3650 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3651 ? string1
3652 : string2 - size1);
3653
3654 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3655
3656 return mcnt;
3657 }
3658
3659 /* Otherwise match next pattern command. */
3660#ifdef SWITCH_ENUM_BUG
3661 switch ((int) ((re_opcode_t) *p++))
3662#else
3663 switch ((re_opcode_t) *p++)
3664#endif
3665 {
3666 /* Ignore these. Used to ignore the n of succeed_n's which
3667 currently have n == 0. */
3668 case no_op:
3669 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3670 break;
3671
3672
3673 /* Match the next n pattern characters exactly. The following
3674 byte in the pattern defines n, and the n bytes after that
3675 are the characters to match. */
3676 case exactn:
3677 mcnt = *p++;
3678 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3679
3680 /* This is written out as an if-else so we don't waste time
3681 testing `translate' inside the loop. */
3682 if (translate)
3683 {
3684 do
3685 {
3686 PREFETCH ();
3687 if (translate[(unsigned char) *d++] != (char) *p++)
3688 goto fail;
3689 }
3690 while (--mcnt);
3691 }
3692 else
3693 {
3694 do
3695 {
3696 PREFETCH ();
3697 if (*d++ != (char) *p++) goto fail;
3698 }
3699 while (--mcnt);
3700 }
3701 SET_REGS_MATCHED ();
3702 break;
3703
3704
3705 /* Match any character except possibly a newline or a null. */
3706 case anychar:
3707 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3708
3709 PREFETCH ();
3710
3711 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3712 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3713 goto fail;
3714
3715 SET_REGS_MATCHED ();
3716 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3717 d++;
3718 break;
3719
3720
3721 case charset:
3722 case charset_not:
3723 {
3724 register unsigned char c;
3725 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3726
3727 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3728
3729 PREFETCH ();
3730 c = TRANSLATE (*d); /* The character to match. */
3731
3732 /* Cast to `unsigned' instead of `unsigned char' in case the
3733 bit list is a full 32 bytes long. */
3734 if (c < (unsigned) (*p * BYTEWIDTH)
3735 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3736 not = !not;
3737
3738 p += 1 + *p;
3739
3740 if (!not) goto fail;
3741
3742 SET_REGS_MATCHED ();
3743 d++;
3744 break;
3745 }
3746
3747
3748 /* The beginning of a group is represented by start_memory.
3749 The arguments are the register number in the next byte, and the
3750 number of groups inner to this one in the next. The text
3751 matched within the group is recorded (in the internal
3752 registers data structure) under the register number. */
3753 case start_memory:
3754 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3755
3756 /* Find out if this group can match the empty string. */
3757 p1 = p; /* To send to group_match_null_string_p. */
3758
3759 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3760 REG_MATCH_NULL_STRING_P (reg_info[*p])
3761 = group_match_null_string_p (&p1, pend, reg_info);
3762
3763 /* Save the position in the string where we were the last time
3764 we were at this open-group operator in case the group is
3765 operated upon by a repetition operator, e.g., with `(a*)*b'
3766 against `ab'; then we want to ignore where we are now in
3767 the string in case this attempt to match fails. */
3768 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3769 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3770 : regstart[*p];
3771 DEBUG_PRINT2 (" old_regstart: %d\n",
3772 POINTER_TO_OFFSET (old_regstart[*p]));
3773
3774 regstart[*p] = d;
3775 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
3776
3777 IS_ACTIVE (reg_info[*p]) = 1;
3778 MATCHED_SOMETHING (reg_info[*p]) = 0;
3779
3780 /* This is the new highest active register. */
3781 highest_active_reg = *p;
3782
3783 /* If nothing was active before, this is the new lowest active
3784 register. */
3785 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3786 lowest_active_reg = *p;
3787
3788 /* Move past the register number and inner group count. */
3789 p += 2;
3790 break;
3791
3792
3793 /* The stop_memory opcode represents the end of a group. Its
3794 arguments are the same as start_memory's: the register
3795 number, and the number of inner groups. */
3796 case stop_memory:
3797 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
3798
3799 /* We need to save the string position the last time we were at
3800 this close-group operator in case the group is operated
3801 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
3802 against `aba'; then we want to ignore where we are now in
3803 the string in case this attempt to match fails. */
3804 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3805 ? REG_UNSET (regend[*p]) ? d : regend[*p]
3806 : regend[*p];
3807 DEBUG_PRINT2 (" old_regend: %d\n",
3808 POINTER_TO_OFFSET (old_regend[*p]));
3809
3810 regend[*p] = d;
3811 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
3812
3813 /* This register isn't active anymore. */
3814 IS_ACTIVE (reg_info[*p]) = 0;
3815
3816 /* If this was the only register active, nothing is active
3817 anymore. */
3818 if (lowest_active_reg == highest_active_reg)
3819 {
3820 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3821 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3822 }
3823 else
3824 { /* We must scan for the new highest active register, since
3825 it isn't necessarily one less than now: consider
3826 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
3827 new highest active register is 1. */
3828 unsigned char r = *p - 1;
3829 while (r > 0 && !IS_ACTIVE (reg_info[r]))
3830 r--;
3831
3832 /* If we end up at register zero, that means that we saved
3833 the registers as the result of an `on_failure_jump', not
3834 a `start_memory', and we jumped to past the innermost
3835 `stop_memory'. For example, in ((.)*) we save
3836 registers 1 and 2 as a result of the *, but when we pop
3837 back to the second ), we are at the stop_memory 1.
3838 Thus, nothing is active. */
3839 if (r == 0)
3840 {
3841 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3842 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3843 }
3844 else
3845 highest_active_reg = r;
3846 }
3847
3848 /* If just failed to match something this time around with a
3849 group that's operated on by a repetition operator, try to
3850 force exit from the ``loop'', and restore the register
3851 information for this group that we had before trying this
3852 last match. */
3853 if ((!MATCHED_SOMETHING (reg_info[*p])
3854 || (re_opcode_t) p[-3] == start_memory)
3855 && (p + 2) < pend)
3856 {
3857 boolean is_a_jump_n = false;
3858
3859 p1 = p + 2;
3860 mcnt = 0;
3861 switch ((re_opcode_t) *p1++)
3862 {
3863 case jump_n:
3864 is_a_jump_n = true;
3865 case pop_failure_jump:
3866 case maybe_pop_jump:
3867 case jump:
3868 case dummy_failure_jump:
3869 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3870 if (is_a_jump_n)
3871 p1 += 2;
3872 break;
3873
3874 default:
3875 /* do nothing */ ;
3876 }
3877 p1 += mcnt;
3878
3879 /* If the next operation is a jump backwards in the pattern
3880 to an on_failure_jump right before the start_memory
3881 corresponding to this stop_memory, exit from the loop
3882 by forcing a failure after pushing on the stack the
3883 on_failure_jump's jump in the pattern, and d. */
3884 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
3885 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
3886 {
3887 /* If this group ever matched anything, then restore
3888 what its registers were before trying this last
3889 failed match, e.g., with `(a*)*b' against `ab' for
3890 regstart[1], and, e.g., with `((a*)*(b*)*)*'
3891 against `aba' for regend[3].
3892
3893 Also restore the registers for inner groups for,
3894 e.g., `((a*)(b*))*' against `aba' (register 3 would
3895 otherwise get trashed). */
3896
3897 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
3898 {
3899 unsigned r;
3900
3901 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
3902
3903 /* Restore this and inner groups' (if any) registers. */
3904 for (r = *p; r < *p + *(p + 1); r++)
3905 {
3906 regstart[r] = old_regstart[r];
3907
3908 /* xx why this test? */
3909 if ((s_reg_t) old_regend[r] >= (s_reg_t) regstart[r])
3910 regend[r] = old_regend[r];
3911 }
3912 }
3913 p1++;
3914 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3915 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
3916 PUSH_FAILURE_POINT2(p1 + mcnt, d, -2);
3917
3918 goto fail;
3919 }
3920 }
3921
3922 /* Move past the register number and the inner group count. */
3923 p += 2;
3924 break;
3925
3926
3927 /* \<digit> has been turned into a `duplicate' command which is
3928 followed by the numeric value of <digit> as the register number. */
3929 case duplicate:
3930 {
3931 register const char *d2, *dend2;
3932 int regno = *p++; /* Get which register to match against. */
3933 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
3934
3935 /* Can't back reference a group which we've never matched. */
3936 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
3937 goto fail;
3938
3939 /* Where in input to try to start matching. */
3940 d2 = regstart[regno];
3941
3942 /* Where to stop matching; if both the place to start and
3943 the place to stop matching are in the same string, then
3944 set to the place to stop, otherwise, for now have to use
3945 the end of the first string. */
3946
3947 dend2 = ((FIRST_STRING_P (regstart[regno])
3948 == FIRST_STRING_P (regend[regno]))
3949 ? regend[regno] : end_match_1);
3950 for (;;)
3951 {
3952 /* If necessary, advance to next segment in register
3953 contents. */
3954 while (d2 == dend2)
3955 {
3956 if (dend2 == end_match_2) break;
3957 if (dend2 == regend[regno]) break;
3958
3959 /* End of string1 => advance to string2. */
3960 d2 = string2;
3961 dend2 = regend[regno];
3962 }
3963 /* At end of register contents => success */
3964 if (d2 == dend2) break;
3965
3966 /* If necessary, advance to next segment in data. */
3967 PREFETCH ();
3968
3969 /* How many characters left in this segment to match. */
3970 mcnt = dend - d;
3971
3972 /* Want how many consecutive characters we can match in
3973 one shot, so, if necessary, adjust the count. */
3974 if (mcnt > dend2 - d2)
3975 mcnt = dend2 - d2;
3976
3977 /* Compare that many; failure if mismatch, else move
3978 past them. */
3979 if (translate
3980 ? bcmp_translate (d, d2, mcnt, translate)
3981 : bcmp (d, d2, mcnt))
3982 goto fail;
3983 d += mcnt, d2 += mcnt;
3984 }
3985 }
3986 break;
3987
398