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regex.c @ 17620

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Revision 17620, 180.0 KB checked in by ghudson, 22 years ago (diff)
This commit was generated by cvs2svn to compensate for changes in r17619, which included commits to RCS files with non-trunk default branches.

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1	/* Extended regular expression matching and search library,
2	version 0.12.
3	(Implements POSIX draft P1003.2/D11.2, except for some of the
4	internationalization features.)
5
6	Copyright (C) 1993-1998 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 Foundation,
20	Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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	#undef _GNU_SOURCE
28	#define _GNU_SOURCE
29
30	#ifdef HAVE_CONFIG_H
31	#include <config.h>
32	#endif
33
34	#if defined(STDC_HEADERS) && !defined(emacs)
35	#include <stddef.h>
36	#else
37	/* We need this for `regex.h', and perhaps for the Emacs include files. */
38	#include <sys/types.h>
39	#endif
40
41	/* For platform which support the ISO C amendement 1 functionality we
42	support user defined character classes. */
43	#if defined _LIBC \|\| (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
44	# include <wctype.h>
45	# include <wchar.h>
46	#endif
47
48	/* This is for other GNU distributions with internationalized messages. */
49	#if HAVE_LIBINTL_H \|\| defined (_LIBC)
50	# include <libintl.h>
51	#else
52	# define gettext(msgid) (msgid)
53	#endif
54
55	#ifndef gettext_noop
56	/* This define is so xgettext can find the internationalizable
57	strings. */
58	#define gettext_noop(String) String
59	#endif
60
61	/* The `emacs' switch turns on certain matching commands
62	that make sense only in Emacs. */
63	#ifdef emacs
64
65	#include "lisp.h"
66	#include "buffer.h"
67	#include "syntax.h"
68
69	#else /* not emacs */
70
71	/* If we are not linking with Emacs proper,
72	we can't use the relocating allocator
73	even if config.h says that we can. */
74	#undef REL_ALLOC
75
76	#if defined (STDC_HEADERS) \|\| defined (_LIBC)
77	#include <stdlib.h>
78	#else
79	char *malloc ();
80	char *realloc ();
81	#endif
82
83	/* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
84	If nothing else has been done, use the method below. */
85	#ifdef INHIBIT_STRING_HEADER
86	#if !(defined (HAVE_BZERO) && defined (HAVE_BCOPY))
87	#if !defined (bzero) && !defined (bcopy)
88	#undef INHIBIT_STRING_HEADER
89	#endif
90	#endif
91	#endif
92
93	/* This is the normal way of making sure we have a bcopy and a bzero.
94	This is used in most programs--a few other programs avoid this
95	by defining INHIBIT_STRING_HEADER. */
96	#ifndef INHIBIT_STRING_HEADER
97	#if defined (HAVE_STRING_H) \|\| defined (STDC_HEADERS) \|\| defined (_LIBC)
98	#include <string.h>
99	#ifndef bcmp
100	#define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
101	#endif
102	#ifndef bcopy
103	#define bcopy(s, d, n) memcpy ((d), (s), (n))
104	#endif
105	#ifndef bzero
106	#define bzero(s, n) memset ((s), 0, (n))
107	#endif
108	#else
109	#include <strings.h>
110	#endif
111	#endif
112
113	/* Define the syntax stuff for \<, \>, etc. */
114
115	/* This must be nonzero for the wordchar and notwordchar pattern
116	commands in re_match_2. */
117	#ifndef Sword
118	#define Sword 1
119	#endif
120
121	#ifdef SWITCH_ENUM_BUG
122	#define SWITCH_ENUM_CAST(x) ((int)(x))
123	#else
124	#define SWITCH_ENUM_CAST(x) (x)
125	#endif
126
127	#ifdef SYNTAX_TABLE
128
129	extern char *re_syntax_table;
130
131	#else /* not SYNTAX_TABLE */
132
133	/* How many characters in the character set. */
134	#define CHAR_SET_SIZE 256
135
136	static char re_syntax_table[CHAR_SET_SIZE];
137
138	static void
139	init_syntax_once ()
140	{
141	register int c;
142	static int done = 0;
143
144	if (done)
145	return;
146
147	bzero (re_syntax_table, sizeof re_syntax_table);
148
149	for (c = 'a'; c <= 'z'; c++)
150	re_syntax_table[c] = Sword;
151
152	for (c = 'A'; c <= 'Z'; c++)
153	re_syntax_table[c] = Sword;
154
155	for (c = '0'; c <= '9'; c++)
156	re_syntax_table[c] = Sword;
157
158	re_syntax_table['_'] = Sword;
159
160	done = 1;
161	}
162
163	#endif /* not SYNTAX_TABLE */
164
165	#define SYNTAX(c) re_syntax_table[c]
166
167	#endif /* not emacs */
168
169	/* Get the interface, including the syntax bits. */
170	#include "regex.h"
171
172	/* isalpha etc. are used for the character classes. */
173	#include <ctype.h>
174
175	/* Jim Meyering writes:
176
177	"... Some ctype macros are valid only for character codes that
178	isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
179	using /bin/cc or gcc but without giving an ansi option). So, all
180	ctype uses should be through macros like ISPRINT... If
181	STDC_HEADERS is defined, then autoconf has verified that the ctype
182	macros don't need to be guarded with references to isascii. ...
183	Defining isascii to 1 should let any compiler worth its salt
184	eliminate the && through constant folding." */
185
186	#if defined (STDC_HEADERS) \|\| (!defined (isascii) && !defined (HAVE_ISASCII))
187	#define ISASCII(c) 1
188	#else
189	#define ISASCII(c) isascii(c)
190	#endif
191
192	#ifdef isblank
193	#define ISBLANK(c) (ISASCII (c) && isblank (c))
194	#else
195	#define ISBLANK(c) ((c) == ' ' \|\| (c) == '\t')
196	#endif
197	#ifdef isgraph
198	#define ISGRAPH(c) (ISASCII (c) && isgraph (c))
199	#else
200	#define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
201	#endif
202
203	#define ISPRINT(c) (ISASCII (c) && isprint (c))
204	#define ISDIGIT(c) (ISASCII (c) && isdigit (c))
205	#define ISALNUM(c) (ISASCII (c) && isalnum (c))
206	#define ISALPHA(c) (ISASCII (c) && isalpha (c))
207	#define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
208	#define ISLOWER(c) (ISASCII (c) && islower (c))
209	#define ISPUNCT(c) (ISASCII (c) && ispunct (c))
210	#define ISSPACE(c) (ISASCII (c) && isspace (c))
211	#define ISUPPER(c) (ISASCII (c) && isupper (c))
212	#define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
213
214	#ifndef NULL
215	#define NULL (void *)0
216	#endif
217
218	/* We remove any previous definition of `SIGN_EXTEND_CHAR',
219	since ours (we hope) works properly with all combinations of
220	machines, compilers, `char' and `unsigned char' argument types.
221	(Per Bothner suggested the basic approach.) */
222	#undef SIGN_EXTEND_CHAR
223	#if __STDC__
224	#define SIGN_EXTEND_CHAR(c) ((signed char) (c))
225	#else /* not __STDC__ */
226	/* As in Harbison and Steele. */
227	#define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
228	#endif
229
230	/* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
231	use `alloca' instead of `malloc'. This is because using malloc in
232	re_search* or re_match* could cause memory leaks when C-g is used in
233	Emacs; also, malloc is slower and causes storage fragmentation. On
234	the other hand, malloc is more portable, and easier to debug.
235
236	Because we sometimes use alloca, some routines have to be macros,
237	not functions -- `alloca'-allocated space disappears at the end of the
238	function it is called in. */
239
240	#ifdef REGEX_MALLOC
241
242	#define REGEX_ALLOCATE malloc
243	#define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
244	#define REGEX_FREE free
245
246	#else /* not REGEX_MALLOC */
247
248	/* Emacs already defines alloca, sometimes. */
249	#ifndef alloca
250
251	/* Make alloca work the best possible way. */
252	#ifdef __GNUC__
253	#define alloca __builtin_alloca
254	#else /* not __GNUC__ */
255	#if HAVE_ALLOCA_H
256	#include <alloca.h>
257	#else /* not __GNUC__ or HAVE_ALLOCA_H */
258	#if 0 /* It is a bad idea to declare alloca. We always cast the result. */
259	#ifndef _AIX /* Already did AIX, up at the top. */
260	char *alloca ();
261	#endif /* not _AIX */
262	#endif
263	#endif /* not HAVE_ALLOCA_H */
264	#endif /* not __GNUC__ */
265
266	#endif /* not alloca */
267
268	#define REGEX_ALLOCATE alloca
269
270	/* Assumes a `char destination' variable. /
271	#define REGEX_REALLOCATE(source, osize, nsize) \
272	(destination = (char *) alloca (nsize), \
273	bcopy (source, destination, osize), \
274	destination)
275
276	/* No need to do anything to free, after alloca. */
277	#define REGEX_FREE(arg) ((void)0) /* Do nothing! But inhibit gcc warning. */
278
279	#endif /* not REGEX_MALLOC */
280
281	/* Define how to allocate the failure stack. */
282
283	#if defined (REL_ALLOC) && defined (REGEX_MALLOC)
284
285	#define REGEX_ALLOCATE_STACK(size) \
286	r_alloc (&failure_stack_ptr, (size))
287	#define REGEX_REALLOCATE_STACK(source, osize, nsize) \
288	r_re_alloc (&failure_stack_ptr, (nsize))
289	#define REGEX_FREE_STACK(ptr) \
290	r_alloc_free (&failure_stack_ptr)
291
292	#else /* not using relocating allocator */
293
294	#ifdef REGEX_MALLOC
295
296	#define REGEX_ALLOCATE_STACK malloc
297	#define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
298	#define REGEX_FREE_STACK free
299
300	#else /* not REGEX_MALLOC */
301
302	#define REGEX_ALLOCATE_STACK alloca
303
304	#define REGEX_REALLOCATE_STACK(source, osize, nsize) \
305	REGEX_REALLOCATE (source, osize, nsize)
306	/* No need to explicitly free anything. */
307	#define REGEX_FREE_STACK(arg)
308
309	#endif /* not REGEX_MALLOC */
310	#endif /* not using relocating allocator */
311
312
313	/* True if `size1' is non-NULL and PTR is pointing anywhere inside
314	`string1' or just past its end. This works if PTR is NULL, which is
315	a good thing. */
316	#define FIRST_STRING_P(ptr) \
317	(size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
318
319	/* (Re)Allocate N items of type T using malloc, or fail. */
320	#define TALLOC(n, t) ((t ) malloc ((n) sizeof (t)))
321	#define RETALLOC(addr, n, t) ((addr) = (t ) realloc (addr, (n) sizeof (t)))
322	#define RETALLOC_IF(addr, n, t) \
323	if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
324	#define REGEX_TALLOC(n, t) ((t ) REGEX_ALLOCATE ((n) sizeof (t)))
325
326	#define BYTEWIDTH 8 /* In bits. */
327
328	#define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
329
330	#undef MAX
331	#undef MIN
332	#define MAX(a, b) ((a) > (b) ? (a) : (b))
333	#define MIN(a, b) ((a) < (b) ? (a) : (b))
334
335	typedef char boolean;
336	#define false 0
337	#define true 1
338
339	static int re_match_2_internal ();
340
341	/* These are the command codes that appear in compiled regular
342	expressions. Some opcodes are followed by argument bytes. A
343	command code can specify any interpretation whatsoever for its
344	arguments. Zero bytes may appear in the compiled regular expression. */
345
346	typedef enum
347	{
348	no_op = 0,
349
350	/* Succeed right away--no more backtracking. */
351	succeed,
352
353	/* Followed by one byte giving n, then by n literal bytes. */
354	exactn,
355
356	/* Matches any (more or less) character. */
357	anychar,
358
359	/* Matches any one char belonging to specified set. First
360	following byte is number of bitmap bytes. Then come bytes
361	for a bitmap saying which chars are in. Bits in each byte
362	are ordered low-bit-first. A character is in the set if its
363	bit is 1. A character too large to have a bit in the map is
364	automatically not in the set. */
365	charset,
366
367	/* Same parameters as charset, but match any character that is
368	not one of those specified. */
369	charset_not,
370
371	/* Start remembering the text that is matched, for storing in a
372	register. Followed by one byte with the register number, in
373	the range 0 to one less than the pattern buffer's re_nsub
374	field. Then followed by one byte with the number of groups
375	inner to this one. (This last has to be part of the
376	start_memory only because we need it in the on_failure_jump
377	of re_match_2.) */
378	start_memory,
379
380	/* Stop remembering the text that is matched and store it in a
381	memory register. Followed by one byte with the register
382	number, in the range 0 to one less than `re_nsub' in the
383	pattern buffer, and one byte with the number of inner groups,
384	just like `start_memory'. (We need the number of inner
385	groups here because we don't have any easy way of finding the
386	corresponding start_memory when we're at a stop_memory.) */
387	stop_memory,
388
389	/* Match a duplicate of something remembered. Followed by one
390	byte containing the register number. */
391	duplicate,
392
393	/* Fail unless at beginning of line. */
394	begline,
395
396	/* Fail unless at end of line. */
397	endline,
398
399	/* Succeeds if at beginning of buffer (if emacs) or at beginning
400	of string to be matched (if not). */
401	begbuf,
402
403	/* Analogously, for end of buffer/string. */
404	endbuf,
405
406	/* Followed by two byte relative address to which to jump. */
407	jump,
408
409	/* Same as jump, but marks the end of an alternative. */
410	jump_past_alt,
411
412	/* Followed by two-byte relative address of place to resume at
413	in case of failure. */
414	on_failure_jump,
415
416	/* Like on_failure_jump, but pushes a placeholder instead of the
417	current string position when executed. */
418	on_failure_keep_string_jump,
419
420	/* Throw away latest failure point and then jump to following
421	two-byte relative address. */
422	pop_failure_jump,
423
424	/* Change to pop_failure_jump if know won't have to backtrack to
425	match; otherwise change to jump. This is used to jump
426	back to the beginning of a repeat. If what follows this jump
427	clearly won't match what the repeat does, such that we can be
428	sure that there is no use backtracking out of repetitions
429	already matched, then we change it to a pop_failure_jump.
430	Followed by two-byte address. */
431	maybe_pop_jump,
432
433	/* Jump to following two-byte address, and push a dummy failure
434	point. This failure point will be thrown away if an attempt
435	is made to use it for a failure. A `+' construct makes this
436	before the first repeat. Also used as an intermediary kind
437	of jump when compiling an alternative. */
438	dummy_failure_jump,
439
440	/* Push a dummy failure point and continue. Used at the end of
441	alternatives. */
442	push_dummy_failure,
443
444	/* Followed by two-byte relative address and two-byte number n.
445	After matching N times, jump to the address upon failure. */
446	succeed_n,
447
448	/* Followed by two-byte relative address, and two-byte number n.
449	Jump to the address N times, then fail. */
450	jump_n,
451
452	/* Set the following two-byte relative address to the
453	subsequent two-byte number. The address includes the two
454	bytes of number. */
455	set_number_at,
456
457	wordchar, /* Matches any word-constituent character. */
458	notwordchar, /* Matches any char that is not a word-constituent. */
459
460	wordbeg, /* Succeeds if at word beginning. */
461	wordend, /* Succeeds if at word end. */
462
463	wordbound, /* Succeeds if at a word boundary. */
464	notwordbound /* Succeeds if not at a word boundary. */
465
466	#ifdef emacs
467	,before_dot, /* Succeeds if before point. */
468	at_dot, /* Succeeds if at point. */
469	after_dot, /* Succeeds if after point. */
470
471	/* Matches any character whose syntax is specified. Followed by
472	a byte which contains a syntax code, e.g., Sword. */
473	syntaxspec,
474
475	/* Matches any character whose syntax is not that specified. */
476	notsyntaxspec
477	#endif /* emacs */
478	} re_opcode_t;
479
480	/* Common operations on the compiled pattern. */
481
482	/* Store NUMBER in two contiguous bytes starting at DESTINATION. */
483
484	#define STORE_NUMBER(destination, number) \
485	do { \
486	(destination)[0] = (number) & 0377; \
487	(destination)[1] = (number) >> 8; \
488	} while (0)
489
490	/* Same as STORE_NUMBER, except increment DESTINATION to
491	the byte after where the number is stored. Therefore, DESTINATION
492	must be an lvalue. */
493
494	#define STORE_NUMBER_AND_INCR(destination, number) \
495	do { \
496	STORE_NUMBER (destination, number); \
497	(destination) += 2; \
498	} while (0)
499
500	/* Put into DESTINATION a number stored in two contiguous bytes starting
501	at SOURCE. */
502
503	#define EXTRACT_NUMBER(destination, source) \
504	do { \
505	(destination) = *(source) & 0377; \
506	(destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
507	} while (0)
508
509	#ifdef DEBUG
510	static void extract_number _RE_ARGS ((int dest, unsigned char source));
511	static void
512	extract_number (dest, source)
513	int *dest;
514	unsigned char *source;
515	{
516	int temp = SIGN_EXTEND_CHAR (*(source + 1));
517	dest = source & 0377;
518	*dest += temp << 8;
519	}
520
521	#ifndef EXTRACT_MACROS /* To debug the macros. */
522	#undef EXTRACT_NUMBER
523	#define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
524	#endif /* not EXTRACT_MACROS */
525
526	#endif /* DEBUG */
527
528	/* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
529	SOURCE must be an lvalue. */
530
531	#define EXTRACT_NUMBER_AND_INCR(destination, source) \
532	do { \
533	EXTRACT_NUMBER (destination, source); \
534	(source) += 2; \
535	} while (0)
536
537	#ifdef DEBUG
538	static void extract_number_and_incr _RE_ARGS ((int *destination,
539	unsigned char **source));
540	static void
541	extract_number_and_incr (destination, source)
542	int *destination;
543	unsigned char **source;
544	{
545	extract_number (destination, *source);
546	*source += 2;
547	}
548
549	#ifndef EXTRACT_MACROS
550	#undef EXTRACT_NUMBER_AND_INCR
551	#define EXTRACT_NUMBER_AND_INCR(dest, src) \
552	extract_number_and_incr (&dest, &src)
553	#endif /* not EXTRACT_MACROS */
554
555	#endif /* DEBUG */
556
557	/* If DEBUG is defined, Regex prints many voluminous messages about what
558	it is doing (if the variable `debug' is nonzero). If linked with the
559	main program in `iregex.c', you can enter patterns and strings
560	interactively. And if linked with the main program in `main.c' and
561	the other test files, you can run the already-written tests. */
562
563	#ifdef DEBUG
564
565	/* We use standard I/O for debugging. */
566	#include <stdio.h>
567
568	/* It is useful to test things that ``must'' be true when debugging. */
569	#include <assert.h>
570
571	static int debug = 0;
572
573	#define DEBUG_STATEMENT(e) e
574	#define DEBUG_PRINT1(x) if (debug) printf (x)
575	#define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
576	#define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
577	#define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
578	#define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
579	if (debug) print_partial_compiled_pattern (s, e)
580	#define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
581	if (debug) print_double_string (w, s1, sz1, s2, sz2)
582
583
584	/* Print the fastmap in human-readable form. */
585
586	void
587	print_fastmap (fastmap)
588	char *fastmap;
589	{
590	unsigned was_a_range = 0;
591	unsigned i = 0;
592
593	while (i < (1 << BYTEWIDTH))
594	{
595	if (fastmap[i++])
596	{
597	was_a_range = 0;
598	putchar (i - 1);
599	while (i < (1 << BYTEWIDTH) && fastmap[i])
600	{
601	was_a_range = 1;
602	i++;
603	}
604	if (was_a_range)
605	{
606	printf ("-");
607	putchar (i - 1);
608	}
609	}
610	}
611	putchar ('\n');
612	}
613
614
615	/* Print a compiled pattern string in human-readable form, starting at
616	the START pointer into it and ending just before the pointer END. */
617
618	void
619	print_partial_compiled_pattern (start, end)
620	unsigned char *start;
621	unsigned char *end;
622	{
623	int mcnt, mcnt2;
624	unsigned char *p1;
625	unsigned char *p = start;
626	unsigned char *pend = end;
627
628	if (start == NULL)
629	{
630	printf ("(null)\n");
631	return;
632	}
633
634	/* Loop over pattern commands. */
635	while (p < pend)
636	{
637	printf ("%d:\t", p - start);
638
639	switch ((re_opcode_t) *p++)
640	{
641	case no_op:
642	printf ("/no_op");
643	break;
644
645	case exactn:
646	mcnt = *p++;
647	printf ("/exactn/%d", mcnt);
648	do
649	{
650	putchar ('/');
651	putchar (*p++);
652	}
653	while (--mcnt);
654	break;
655
656	case start_memory:
657	mcnt = *p++;
658	printf ("/start_memory/%d/%d", mcnt, *p++);
659	break;
660
661	case stop_memory:
662	mcnt = *p++;
663	printf ("/stop_memory/%d/%d", mcnt, *p++);
664	break;
665
666	case duplicate:
667	printf ("/duplicate/%d", *p++);
668	break;
669
670	case anychar:
671	printf ("/anychar");
672	break;
673
674	case charset:
675	case charset_not:
676	{
677	register int c, last = -100;
678	register int in_range = 0;
679
680	printf ("/charset [%s",
681	(re_opcode_t) *(p - 1) == charset_not ? "^" : "");
682
683	assert (p + *p < pend);
684
685	for (c = 0; c < 256; c++)
686	if (c / 8 < *p
687	&& (p[1 + (c/8)] & (1 << (c % 8))))
688	{
689	/* Are we starting a range? */
690	if (last + 1 == c && ! in_range)
691	{
692	putchar ('-');
693	in_range = 1;
694	}
695	/* Have we broken a range? */
696	else if (last + 1 != c && in_range)
697	{
698	putchar (last);
699	in_range = 0;
700	}
701
702	if (! in_range)
703	putchar (c);
704
705	last = c;
706	}
707
708	if (in_range)
709	putchar (last);
710
711	putchar (']');
712
713	p += 1 + *p;
714	}
715	break;
716
717	case begline:
718	printf ("/begline");
719	break;
720
721	case endline:
722	printf ("/endline");
723	break;
724
725	case on_failure_jump:
726	extract_number_and_incr (&mcnt, &p);
727	printf ("/on_failure_jump to %d", p + mcnt - start);
728	break;
729
730	case on_failure_keep_string_jump:
731	extract_number_and_incr (&mcnt, &p);
732	printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
733	break;
734
735	case dummy_failure_jump:
736	extract_number_and_incr (&mcnt, &p);
737	printf ("/dummy_failure_jump to %d", p + mcnt - start);
738	break;
739
740	case push_dummy_failure:
741	printf ("/push_dummy_failure");
742	break;
743
744	case maybe_pop_jump:
745	extract_number_and_incr (&mcnt, &p);
746	printf ("/maybe_pop_jump to %d", p + mcnt - start);
747	break;
748
749	case pop_failure_jump:
750	extract_number_and_incr (&mcnt, &p);
751	printf ("/pop_failure_jump to %d", p + mcnt - start);
752	break;
753
754	case jump_past_alt:
755	extract_number_and_incr (&mcnt, &p);
756	printf ("/jump_past_alt to %d", p + mcnt - start);
757	break;
758
759	case jump:
760	extract_number_and_incr (&mcnt, &p);
761	printf ("/jump to %d", p + mcnt - start);
762	break;
763
764	case succeed_n:
765	extract_number_and_incr (&mcnt, &p);
766	p1 = p + mcnt;
767	extract_number_and_incr (&mcnt2, &p);
768	printf ("/succeed_n to %d, %d times", p1 - start, mcnt2);
769	break;
770
771	case jump_n:
772	extract_number_and_incr (&mcnt, &p);
773	p1 = p + mcnt;
774	extract_number_and_incr (&mcnt2, &p);
775	printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
776	break;
777
778	case set_number_at:
779	extract_number_and_incr (&mcnt, &p);
780	p1 = p + mcnt;
781	extract_number_and_incr (&mcnt2, &p);
782	printf ("/set_number_at location %d to %d", p1 - start, mcnt2);
783	break;
784
785	case wordbound:
786	printf ("/wordbound");
787	break;
788
789	case notwordbound:
790	printf ("/notwordbound");
791	break;
792
793	case wordbeg:
794	printf ("/wordbeg");
795	break;
796
797	case wordend:
798	printf ("/wordend");
799
800	#ifdef emacs
801	case before_dot:
802	printf ("/before_dot");
803	break;
804
805	case at_dot:
806	printf ("/at_dot");
807	break;
808
809	case after_dot:
810	printf ("/after_dot");
811	break;
812
813	case syntaxspec:
814	printf ("/syntaxspec");
815	mcnt = *p++;
816	printf ("/%d", mcnt);
817	break;
818
819	case notsyntaxspec:
820	printf ("/notsyntaxspec");
821	mcnt = *p++;
822	printf ("/%d", mcnt);
823	break;
824	#endif /* emacs */
825
826	case wordchar:
827	printf ("/wordchar");
828	break;
829
830	case notwordchar:
831	printf ("/notwordchar");
832	break;
833
834	case begbuf:
835	printf ("/begbuf");
836	break;
837
838	case endbuf:
839	printf ("/endbuf");
840	break;
841
842	default:
843	printf ("?%d", *(p-1));
844	}
845
846	putchar ('\n');
847	}
848
849	printf ("%d:\tend of pattern.\n", p - start);
850	}
851
852
853	void
854	print_compiled_pattern (bufp)
855	struct re_pattern_buffer *bufp;
856	{
857	unsigned char *buffer = bufp->buffer;
858
859	print_partial_compiled_pattern (buffer, buffer + bufp->used);
860	printf ("%ld bytes used/%ld bytes allocated.\n",
861	bufp->used, bufp->allocated);
862
863	if (bufp->fastmap_accurate && bufp->fastmap)
864	{
865	printf ("fastmap: ");
866	print_fastmap (bufp->fastmap);
867	}
868
869	printf ("re_nsub: %d\t", bufp->re_nsub);
870	printf ("regs_alloc: %d\t", bufp->regs_allocated);
871	printf ("can_be_null: %d\t", bufp->can_be_null);
872	printf ("newline_anchor: %d\n", bufp->newline_anchor);
873	printf ("no_sub: %d\t", bufp->no_sub);
874	printf ("not_bol: %d\t", bufp->not_bol);
875	printf ("not_eol: %d\t", bufp->not_eol);
876	printf ("syntax: %lx\n", bufp->syntax);
877	/* Perhaps we should print the translate table? */
878	}
879
880
881	void
882	print_double_string (where, string1, size1, string2, size2)
883	const char *where;
884	const char *string1;
885	const char *string2;
886	int size1;
887	int size2;
888	{
889	int this_char;
890
891	if (where == NULL)
892	printf ("(null)");
893	else
894	{
895	if (FIRST_STRING_P (where))
896	{
897	for (this_char = where - string1; this_char < size1; this_char++)
898	putchar (string1[this_char]);
899
900	where = string2;
901	}
902
903	for (this_char = where - string2; this_char < size2; this_char++)
904	putchar (string2[this_char]);
905	}
906	}
907
908	void
909	printchar (c)
910	int c;
911	{
912	putc (c, stderr);
913	}
914
915	#else /* not DEBUG */
916
917	#undef assert
918	#define assert(e)
919
920	#define DEBUG_STATEMENT(e)
921	#define DEBUG_PRINT1(x)
922	#define DEBUG_PRINT2(x1, x2)
923	#define DEBUG_PRINT3(x1, x2, x3)
924	#define DEBUG_PRINT4(x1, x2, x3, x4)
925	#define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
926	#define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
927
928	#endif /* not DEBUG */
929
930	/* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
931	also be assigned to arbitrarily: each pattern buffer stores its own
932	syntax, so it can be changed between regex compilations. */
933	/* This has no initializer because initialized variables in Emacs
934	become read-only after dumping. */
935	reg_syntax_t re_syntax_options;
936
937
938	/* Specify the precise syntax of regexps for compilation. This provides
939	for compatibility for various utilities which historically have
940	different, incompatible syntaxes.
941
942	The argument SYNTAX is a bit mask comprised of the various bits
943	defined in regex.h. We return the old syntax. */
944
945	reg_syntax_t
946	re_set_syntax (syntax)
947	reg_syntax_t syntax;
948	{
949	reg_syntax_t ret = re_syntax_options;
950
951	re_syntax_options = syntax;
952	#ifdef DEBUG
953	if (syntax & RE_DEBUG)
954	debug = 1;
955	else if (debug) /* was on but now is not */
956	debug = 0;
957	#endif /* DEBUG */
958	return ret;
959	}
960
961	void
962	#if __STDC__
963	re_set_character_syntax (unsigned char ch, char syntax)
964	#else
965	re_set_character_syntax (ch, syntax)
966	unsigned char ch;
967	char syntax;
968	#endif /* not __STDC__ */
969	{
970	init_syntax_once ();
971
972	switch (syntax)
973	{
974	case 'w':
975	SYNTAX (ch) = Sword;
976	break;
977
978	case ' ':
979	SYNTAX (ch) = 0;
980	break;
981
982	default:
983	/* This is an error, but we don't care. */
984	break;
985	}
986	}
987
988
989	/* This table gives an error message for each of the error codes listed
990	in regex.h. Obviously the order here has to be same as there.
991	POSIX doesn't require that we do anything for REG_NOERROR,
992	but why not be nice? */
993
994	static const char *re_error_msgid[] =
995	{
996	gettext_noop ("Success"), /* REG_NOERROR */
997	gettext_noop ("No match"), /* REG_NOMATCH */
998	gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
999	gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
1000	gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
1001	gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
1002	gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
1003	gettext_noop ("Unmatched [ or [^"), /* REG_EBRACK */
1004	gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
1005	gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
1006	gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
1007	gettext_noop ("Invalid range end"), /* REG_ERANGE */
1008	gettext_noop ("Memory exhausted"), /* REG_ESPACE */
1009	gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
1010	gettext_noop ("Premature end of regular expression"), /* REG_EEND */
1011	gettext_noop ("Regular expression too big"), /* REG_ESIZE */
1012	gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
1013	};
1014
1015	/* Avoiding alloca during matching, to placate r_alloc. */
1016
1017	/* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
1018	searching and matching functions should not call alloca. On some
1019	systems, alloca is implemented in terms of malloc, and if we're
1020	using the relocating allocator routines, then malloc could cause a
1021	relocation, which might (if the strings being searched are in the
1022	ralloc heap) shift the data out from underneath the regexp
1023	routines.
1024
1025	Here's another reason to avoid allocation: Emacs
1026	processes input from X in a signal handler; processing X input may
1027	call malloc; if input arrives while a matching routine is calling
1028	malloc, then we're scrod. But Emacs can't just block input while
1029	calling matching routines; then we don't notice interrupts when
1030	they come in. So, Emacs blocks input around all regexp calls
1031	except the matching calls, which it leaves unprotected, in the
1032	faith that they will not malloc. */
1033
1034	/* Normally, this is fine. */
1035	#define MATCH_MAY_ALLOCATE
1036
1037	/* When using GNU C, we are not REALLY using the C alloca, no matter
1038	what config.h may say. So don't take precautions for it. */
1039	#ifdef __GNUC__
1040	#undef C_ALLOCA
1041	#endif
1042
1043	/* The match routines may not allocate if (1) they would do it with malloc
1044	and (2) it's not safe for them to use malloc.
1045	Note that if REL_ALLOC is defined, matching would not use malloc for the
1046	failure stack, but we would still use it for the register vectors;
1047	so REL_ALLOC should not affect this. */
1048	#if (defined (C_ALLOCA) \|\| defined (REGEX_MALLOC)) && defined (emacs)
1049	#undef MATCH_MAY_ALLOCATE
1050	#endif
1051
1052
1053	/* Failure stack declarations and macros; both re_compile_fastmap and
1054	re_match_2 use a failure stack. These have to be macros because of
1055	REGEX_ALLOCATE_STACK. */
1056
1057
1058	/* Number of failure points for which to initially allocate space
1059	when matching. If this number is exceeded, we allocate more
1060	space, so it is not a hard limit. */
1061	#ifndef INIT_FAILURE_ALLOC
1062	#define INIT_FAILURE_ALLOC 5
1063	#endif
1064
1065	/* Roughly the maximum number of failure points on the stack. Would be
1066	exactly that if always used MAX_FAILURE_ITEMS items each time we failed.
1067	This is a variable only so users of regex can assign to it; we never
1068	change it ourselves. */
1069
1070	#ifdef INT_IS_16BIT
1071
1072	#if defined (MATCH_MAY_ALLOCATE)
1073	/* 4400 was enough to cause a crash on Alpha OSF/1,
1074	whose default stack limit is 2mb. */
1075	long int re_max_failures = 4000;
1076	#else
1077	long int re_max_failures = 2000;
1078	#endif
1079
1080	union fail_stack_elt
1081	{
1082	unsigned char *pointer;
1083	long int integer;
1084	};
1085
1086	typedef union fail_stack_elt fail_stack_elt_t;
1087
1088	typedef struct
1089	{
1090	fail_stack_elt_t *stack;
1091	unsigned long int size;
1092	unsigned long int avail; /* Offset of next open position. */
1093	} fail_stack_type;
1094
1095	#else /* not INT_IS_16BIT */
1096
1097	#if defined (MATCH_MAY_ALLOCATE)
1098	/* 4400 was enough to cause a crash on Alpha OSF/1,
1099	whose default stack limit is 2mb. */
1100	int re_max_failures = 20000;
1101	#else
1102	int re_max_failures = 2000;
1103	#endif
1104
1105	union fail_stack_elt
1106	{
1107	unsigned char *pointer;
1108	int integer;
1109	};
1110
1111	typedef union fail_stack_elt fail_stack_elt_t;
1112
1113	typedef struct
1114	{
1115	fail_stack_elt_t *stack;
1116	unsigned size;
1117	unsigned avail; /* Offset of next open position. */
1118	} fail_stack_type;
1119
1120	#endif /* INT_IS_16BIT */
1121
1122	#define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
1123	#define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
1124	#define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
1125
1126
1127	/* Define macros to initialize and free the failure stack.
1128	Do `return -2' if the alloc fails. */
1129
1130	#ifdef MATCH_MAY_ALLOCATE
1131	#define INIT_FAIL_STACK() \
1132	do { \
1133	fail_stack.stack = (fail_stack_elt_t *) \
1134	REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
1135	\
1136	if (fail_stack.stack == NULL) \
1137	return -2; \
1138	\
1139	fail_stack.size = INIT_FAILURE_ALLOC; \
1140	fail_stack.avail = 0; \
1141	} while (0)
1142
1143	#define RESET_FAIL_STACK() REGEX_FREE_STACK (fail_stack.stack)
1144	#else
1145	#define INIT_FAIL_STACK() \
1146	do { \
1147	fail_stack.avail = 0; \
1148	} while (0)
1149
1150	#define RESET_FAIL_STACK()
1151	#endif
1152
1153
1154	/* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
1155
1156	Return 1 if succeeds, and 0 if either ran out of memory
1157	allocating space for it or it was already too large.
1158
1159	REGEX_REALLOCATE_STACK requires `destination' be declared. */
1160
1161	#define DOUBLE_FAIL_STACK(fail_stack) \
1162	((fail_stack).size > (unsigned) (re_max_failures * MAX_FAILURE_ITEMS) \
1163	? 0 \
1164	: ((fail_stack).stack = (fail_stack_elt_t *) \
1165	REGEX_REALLOCATE_STACK ((fail_stack).stack, \
1166	(fail_stack).size * sizeof (fail_stack_elt_t), \
1167	((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
1168	\
1169	(fail_stack).stack == NULL \
1170	? 0 \
1171	: ((fail_stack).size <<= 1, \
1172	1)))
1173
1174
1175	/* Push pointer POINTER on FAIL_STACK.
1176	Return 1 if was able to do so and 0 if ran out of memory allocating
1177	space to do so. */
1178	#define PUSH_PATTERN_OP(POINTER, FAIL_STACK) \
1179	((FAIL_STACK_FULL () \
1180	&& !DOUBLE_FAIL_STACK (FAIL_STACK)) \
1181	? 0 \
1182	: ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER, \
1183	1))
1184
1185	/* Push a pointer value onto the failure stack.
1186	Assumes the variable `fail_stack'. Probably should only
1187	be called from within `PUSH_FAILURE_POINT'. */
1188	#define PUSH_FAILURE_POINTER(item) \
1189	fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
1190
1191	/* This pushes an integer-valued item onto the failure stack.
1192	Assumes the variable `fail_stack'. Probably should only
1193	be called from within `PUSH_FAILURE_POINT'. */
1194	#define PUSH_FAILURE_INT(item) \
1195	fail_stack.stack[fail_stack.avail++].integer = (item)
1196
1197	/* Push a fail_stack_elt_t value onto the failure stack.
1198	Assumes the variable `fail_stack'. Probably should only
1199	be called from within `PUSH_FAILURE_POINT'. */
1200	#define PUSH_FAILURE_ELT(item) \
1201	fail_stack.stack[fail_stack.avail++] = (item)
1202
1203	/* These three POP... operations complement the three PUSH... operations.
1204	All assume that `fail_stack' is nonempty. */
1205	#define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
1206	#define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
1207	#define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
1208
1209	/* Used to omit pushing failure point id's when we're not debugging. */
1210	#ifdef DEBUG
1211	#define DEBUG_PUSH PUSH_FAILURE_INT
1212	#define DEBUG_POP(item_addr) (item_addr)->integer = POP_FAILURE_INT ()
1213	#else
1214	#define DEBUG_PUSH(item)
1215	#define DEBUG_POP(item_addr)
1216	#endif
1217
1218
1219	/* Push the information about the state we will need
1220	if we ever fail back to it.
1221
1222	Requires variables fail_stack, regstart, regend, reg_info, and
1223	num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
1224	declared.
1225
1226	Does `return FAILURE_CODE' if runs out of memory. */
1227
1228	#define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1229	do { \
1230	char *destination; \
1231	/* Must be int, so when we don't save any registers, the arithmetic \
1232	of 0 + -1 isn't done as unsigned. */ \
1233	/* Can't be int, since there is not a shred of a guarantee that int \
1234	is wide enough to hold a value of something to which pointer can \
1235	be assigned */ \
1236	s_reg_t this_reg; \
1237	\
1238	DEBUG_STATEMENT (failure_id++); \
1239	DEBUG_STATEMENT (nfailure_points_pushed++); \
1240	DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1241	DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1242	DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1243	\
1244	DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
1245	DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1246	\
1247	/* Ensure we have enough space allocated for what we will push. */ \
1248	while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1249	{ \
1250	if (!DOUBLE_FAIL_STACK (fail_stack)) \
1251	return failure_code; \
1252	\
1253	DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1254	(fail_stack).size); \
1255	DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1256	} \
1257	\
1258	/* Push the info, starting with the registers. */ \
1259	DEBUG_PRINT1 ("\n"); \
1260	\
1261	if (1) \
1262	for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
1263	this_reg++) \
1264	{ \
1265	DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
1266	DEBUG_STATEMENT (num_regs_pushed++); \
1267	\
1268	DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1269	PUSH_FAILURE_POINTER (regstart[this_reg]); \
1270	\
1271	DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1272	PUSH_FAILURE_POINTER (regend[this_reg]); \
1273	\
1274	DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
1275	DEBUG_PRINT2 (" match_null=%d", \
1276	REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1277	DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1278	DEBUG_PRINT2 (" matched_something=%d", \
1279	MATCHED_SOMETHING (reg_info[this_reg])); \
1280	DEBUG_PRINT2 (" ever_matched=%d", \
1281	EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1282	DEBUG_PRINT1 ("\n"); \
1283	PUSH_FAILURE_ELT (reg_info[this_reg].word); \
1284	} \
1285	\
1286	DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
1287	PUSH_FAILURE_INT (lowest_active_reg); \
1288	\
1289	DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
1290	PUSH_FAILURE_INT (highest_active_reg); \
1291	\
1292	DEBUG_PRINT2 (" Pushing pattern 0x%x:\n", pattern_place); \
1293	DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1294	PUSH_FAILURE_POINTER (pattern_place); \
1295	\
1296	DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
1297	DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1298	size2); \
1299	DEBUG_PRINT1 ("'\n"); \
1300	PUSH_FAILURE_POINTER (string_place); \
1301	\
1302	DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1303	DEBUG_PUSH (failure_id); \
1304	} while (0)
1305
1306	/* This is the number of items that are pushed and popped on the stack
1307	for each register. */
1308	#define NUM_REG_ITEMS 3
1309
1310	/* Individual items aside from the registers. */
1311	#ifdef DEBUG
1312	#define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1313	#else
1314	#define NUM_NONREG_ITEMS 4
1315	#endif
1316
1317	/* We push at most this many items on the stack. */
1318	/* We used to use (num_regs - 1), which is the number of registers
1319	this regexp will save; but that was changed to 5
1320	to avoid stack overflow for a regexp with lots of parens. */
1321	#define MAX_FAILURE_ITEMS (5 * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1322
1323	/* We actually push this many items. */
1324	#define NUM_FAILURE_ITEMS \
1325	(((0 \
1326	? 0 : highest_active_reg - lowest_active_reg + 1) \
1327	* NUM_REG_ITEMS) \
1328	+ NUM_NONREG_ITEMS)
1329
1330	/* How many items can still be added to the stack without overflowing it. */
1331	#define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1332
1333
1334	/* Pops what PUSH_FAIL_STACK pushes.
1335
1336	We restore into the parameters, all of which should be lvalues:
1337	STR -- the saved data position.
1338	PAT -- the saved pattern position.
1339	LOW_REG, HIGH_REG -- the highest and lowest active registers.
1340	REGSTART, REGEND -- arrays of string positions.
1341	REG_INFO -- array of information about each subexpression.
1342
1343	Also assumes the variables `fail_stack' and (if debugging), `bufp',
1344	`pend', `string1', `size1', `string2', and `size2'. */
1345
1346	#define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1347	{ \
1348	DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
1349	s_reg_t this_reg; \
1350	const unsigned char *string_temp; \
1351	\
1352	assert (!FAIL_STACK_EMPTY ()); \
1353	\
1354	/* Remove failure points and point to how many regs pushed. */ \
1355	DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1356	DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1357	DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1358	\
1359	assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1360	\
1361	DEBUG_POP (&failure_id); \
1362	DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1363	\
1364	/* If the saved string location is NULL, it came from an \
1365	on_failure_keep_string_jump opcode, and we want to throw away the \
1366	saved NULL, thus retaining our current position in the string. */ \
1367	string_temp = POP_FAILURE_POINTER (); \
1368	if (string_temp != NULL) \
1369	str = (const char *) string_temp; \
1370	\
1371	DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
1372	DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1373	DEBUG_PRINT1 ("'\n"); \
1374	\
1375	pat = (unsigned char *) POP_FAILURE_POINTER (); \
1376	DEBUG_PRINT2 (" Popping pattern 0x%x:\n", pat); \
1377	DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1378	\
1379	/* Restore register info. */ \
1380	high_reg = (active_reg_t) POP_FAILURE_INT (); \
1381	DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
1382	\
1383	low_reg = (active_reg_t) POP_FAILURE_INT (); \
1384	DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
1385	\
1386	if (1) \
1387	for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
1388	{ \
1389	DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
1390	\
1391	reg_info[this_reg].word = POP_FAILURE_ELT (); \
1392	DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
1393	\
1394	regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1395	DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1396	\
1397	regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1398	DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1399	} \
1400	else \
1401	{ \
1402	for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \
1403	{ \
1404	reg_info[this_reg].word.integer = 0; \
1405	regend[this_reg] = 0; \
1406	regstart[this_reg] = 0; \
1407	} \
1408	highest_active_reg = high_reg; \
1409	} \
1410	\
1411	set_regs_matched_done = 0; \
1412	DEBUG_STATEMENT (nfailure_points_popped++); \
1413	} /* POP_FAILURE_POINT */
1414
1415
1416
1417	/* Structure for per-register (a.k.a. per-group) information.
1418	Other register information, such as the
1419	starting and ending positions (which are addresses), and the list of
1420	inner groups (which is a bits list) are maintained in separate
1421	variables.
1422
1423	We are making a (strictly speaking) nonportable assumption here: that
1424	the compiler will pack our bit fields into something that fits into
1425	the type of `word', i.e., is something that fits into one item on the
1426	failure stack. */
1427
1428
1429	/* Declarations and macros for re_match_2. */
1430
1431	typedef union
1432	{
1433	fail_stack_elt_t word;
1434	struct
1435	{
1436	/* This field is one if this group can match the empty string,
1437	zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1438	#define MATCH_NULL_UNSET_VALUE 3
1439	unsigned match_null_string_p : 2;
1440	unsigned is_active : 1;
1441	unsigned matched_something : 1;
1442	unsigned ever_matched_something : 1;
1443	} bits;
1444	} register_info_type;
1445
1446	#define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1447	#define IS_ACTIVE(R) ((R).bits.is_active)
1448	#define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1449	#define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1450
1451
1452	/* Call this when have matched a real character; it sets `matched' flags
1453	for the subexpressions which we are currently inside. Also records
1454	that those subexprs have matched. */
1455	#define SET_REGS_MATCHED() \
1456	do \
1457	{ \
1458	if (!set_regs_matched_done) \
1459	{ \
1460	active_reg_t r; \
1461	set_regs_matched_done = 1; \
1462	for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1463	{ \
1464	MATCHED_SOMETHING (reg_info[r]) \
1465	= EVER_MATCHED_SOMETHING (reg_info[r]) \
1466	= 1; \
1467	} \
1468	} \
1469	} \
1470	while (0)
1471
1472	/* Registers are set to a sentinel when they haven't yet matched. */
1473	static char reg_unset_dummy;
1474	#define REG_UNSET_VALUE (&reg_unset_dummy)
1475	#define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1476
1477	/* Subroutine declarations and macros for regex_compile. */
1478
1479	static reg_errcode_t regex_compile _RE_ARGS ((const char *pattern, size_t size,
1480	reg_syntax_t syntax,
1481	struct re_pattern_buffer *bufp));
1482	static void store_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg));
1483	static void store_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1484	int arg1, int arg2));
1485	static void insert_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1486	int arg, unsigned char *end));
1487	static void insert_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1488	int arg1, int arg2, unsigned char *end));
1489	static boolean at_begline_loc_p _RE_ARGS ((const char pattern, const char p,
1490	reg_syntax_t syntax));
1491	static boolean at_endline_loc_p _RE_ARGS ((const char p, const char pend,
1492	reg_syntax_t syntax));
1493	static reg_errcode_t compile_range _RE_ARGS ((const char **p_ptr,
1494	const char *pend,
1495	char *translate,
1496	reg_syntax_t syntax,
1497	unsigned char *b));
1498
1499	/* Fetch the next character in the uncompiled pattern---translating it
1500	if necessary. Also cast from a signed character in the constant
1501	string passed to us by the user to an unsigned char that we can use
1502	as an array index (in, e.g., `translate'). */
1503	#ifndef PATFETCH
1504	#define PATFETCH(c) \
1505	do {if (p == pend) return REG_EEND; \
1506	c = (unsigned char) *p++; \
1507	if (translate) c = (unsigned char) translate[c]; \
1508	} while (0)
1509	#endif
1510
1511	/* Fetch the next character in the uncompiled pattern, with no
1512	translation. */
1513	#define PATFETCH_RAW(c) \
1514	do {if (p == pend) return REG_EEND; \
1515	c = (unsigned char) *p++; \
1516	} while (0)
1517
1518	/* Go backwards one character in the pattern. */
1519	#define PATUNFETCH p--
1520
1521
1522	/* If `translate' is non-null, return translate[D], else just D. We
1523	cast the subscript to translate because some data is declared as
1524	`char *', to avoid warnings when a string constant is passed. But
1525	when we use a character as a subscript we must make it unsigned. */
1526	#ifndef TRANSLATE
1527	#define TRANSLATE(d) \
1528	(translate ? (char) translate[(unsigned char) (d)] : (d))
1529	#endif
1530
1531
1532	/* Macros for outputting the compiled pattern into `buffer'. */
1533
1534	/* If the buffer isn't allocated when it comes in, use this. */
1535	#define INIT_BUF_SIZE 32
1536
1537	/* Make sure we have at least N more bytes of space in buffer. */
1538	#define GET_BUFFER_SPACE(n) \
1539	while ((unsigned long) (b - bufp->buffer + (n)) > bufp->allocated) \
1540	EXTEND_BUFFER ()
1541
1542	/* Make sure we have one more byte of buffer space and then add C to it. */
1543	#define BUF_PUSH(c) \
1544	do { \
1545	GET_BUFFER_SPACE (1); \
1546	*b++ = (unsigned char) (c); \
1547	} while (0)
1548
1549
1550	/* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1551	#define BUF_PUSH_2(c1, c2) \
1552	do { \
1553	GET_BUFFER_SPACE (2); \
1554	*b++ = (unsigned char) (c1); \
1555	*b++ = (unsigned char) (c2); \
1556	} while (0)
1557
1558
1559	/* As with BUF_PUSH_2, except for three bytes. */
1560	#define BUF_PUSH_3(c1, c2, c3) \
1561	do { \
1562	GET_BUFFER_SPACE (3); \
1563	*b++ = (unsigned char) (c1); \
1564	*b++ = (unsigned char) (c2); \
1565	*b++ = (unsigned char) (c3); \
1566	} while (0)
1567
1568
1569	/* Store a jump with opcode OP at LOC to location TO. We store a
1570	relative address offset by the three bytes the jump itself occupies. */
1571	#define STORE_JUMP(op, loc, to) \
1572	store_op1 (op, loc, (int) ((to) - (loc) - 3))
1573
1574	/* Likewise, for a two-argument jump. */
1575	#define STORE_JUMP2(op, loc, to, arg) \
1576	store_op2 (op, loc, (int) ((to) - (loc) - 3), arg)
1577
1578	/* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1579	#define INSERT_JUMP(op, loc, to) \
1580	insert_op1 (op, loc, (int) ((to) - (loc) - 3), b)
1581
1582	/* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1583	#define INSERT_JUMP2(op, loc, to, arg) \
1584	insert_op2 (op, loc, (int) ((to) - (loc) - 3), arg, b)
1585
1586
1587	/* This is not an arbitrary limit: the arguments which represent offsets
1588	into the pattern are two bytes long. So if 2^16 bytes turns out to
1589	be too small, many things would have to change. */
1590	/* Any other compiler which, like MSC, has allocation limit below 2^16
1591	bytes will have to use approach similar to what was done below for
1592	MSC and drop MAX_BUF_SIZE a bit. Otherwise you may end up
1593	reallocating to 0 bytes. Such thing is not going to work too well.
1594	You have been warned!! */
1595	#if defined(_MSC_VER) && !defined(WIN32)
1596	/* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
1597	The REALLOC define eliminates a flurry of conversion warnings,
1598	but is not required. */
1599	#define MAX_BUF_SIZE 65500L
1600	#define REALLOC(p,s) realloc ((p), (size_t) (s))
1601	#else
1602	#define MAX_BUF_SIZE (1L << 16)
1603	#define REALLOC(p,s) realloc ((p), (s))
1604	#endif
1605
1606	/* Extend the buffer by twice its current size via realloc and
1607	reset the pointers that pointed into the old block to point to the
1608	correct places in the new one. If extending the buffer results in it
1609	being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1610	#define EXTEND_BUFFER() \
1611	do { \
1612	unsigned char *old_buffer = bufp->buffer; \
1613	if (bufp->allocated == MAX_BUF_SIZE) \
1614	return REG_ESIZE; \
1615	bufp->allocated <<= 1; \
1616	if (bufp->allocated > MAX_BUF_SIZE) \
1617	bufp->allocated = MAX_BUF_SIZE; \
1618	bufp->buffer = (unsigned char *) REALLOC (bufp->buffer, bufp->allocated);\
1619	if (bufp->buffer == NULL) \
1620	return REG_ESPACE; \
1621	/* If the buffer moved, move all the pointers into it. */ \
1622	if (old_buffer != bufp->buffer) \
1623	{ \
1624	b = (b - old_buffer) + bufp->buffer; \
1625	begalt = (begalt - old_buffer) + bufp->buffer; \
1626	if (fixup_alt_jump) \
1627	fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1628	if (laststart) \
1629	laststart = (laststart - old_buffer) + bufp->buffer; \
1630	if (pending_exact) \
1631	pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1632	} \
1633	} while (0)
1634
1635
1636	/* Since we have one byte reserved for the register number argument to
1637	{start,stop}_memory, the maximum number of groups we can report
1638	things about is what fits in that byte. */
1639	#define MAX_REGNUM 255
1640
1641	/* But patterns can have more than `MAX_REGNUM' registers. We just
1642	ignore the excess. */
1643	typedef unsigned regnum_t;
1644
1645
1646	/* Macros for the compile stack. */
1647
1648	/* Since offsets can go either forwards or backwards, this type needs to
1649	be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1650	/* int may be not enough when sizeof(int) == 2. */
1651	typedef long pattern_offset_t;
1652
1653	typedef struct
1654	{
1655	pattern_offset_t begalt_offset;
1656	pattern_offset_t fixup_alt_jump;
1657	pattern_offset_t inner_group_offset;
1658	pattern_offset_t laststart_offset;
1659	regnum_t regnum;
1660	} compile_stack_elt_t;
1661
1662
1663	typedef struct
1664	{
1665	compile_stack_elt_t *stack;
1666	unsigned size;
1667	unsigned avail; /* Offset of next open position. */
1668	} compile_stack_type;
1669
1670
1671	#define INIT_COMPILE_STACK_SIZE 32
1672
1673	#define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1674	#define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1675
1676	/* The next available element. */
1677	#define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1678
1679
1680	/* Set the bit for character C in a list. */
1681	#define SET_LIST_BIT(c) \
1682	(b[((unsigned char) (c)) / BYTEWIDTH] \
1683	\|= 1 << (((unsigned char) c) % BYTEWIDTH))
1684
1685
1686	/* Get the next unsigned number in the uncompiled pattern. */
1687	#define GET_UNSIGNED_NUMBER(num) \
1688	{ if (p != pend) \
1689	{ \
1690	PATFETCH (c); \
1691	while (ISDIGIT (c)) \
1692	{ \
1693	if (num < 0) \
1694	num = 0; \
1695	num = num * 10 + c - '0'; \
1696	if (p == pend) \
1697	break; \
1698	PATFETCH (c); \
1699	} \
1700	} \
1701	}
1702
1703	#if defined _LIBC \|\| (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
1704	/* The GNU C library provides support for user-defined character classes
1705	and the functions from ISO C amendement 1. */
1706	# ifdef CHARCLASS_NAME_MAX
1707	# define CHAR_CLASS_MAX_LENGTH CHARCLASS_NAME_MAX
1708	# else
1709	/* This shouldn't happen but some implementation might still have this
1710	problem. Use a reasonable default value. */
1711	# define CHAR_CLASS_MAX_LENGTH 256
1712	# endif
1713
1714	# define IS_CHAR_CLASS(string) wctype (string)
1715	#else
1716	# define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1717
1718	# define IS_CHAR_CLASS(string) \
1719	(STREQ (string, "alpha") \|\| STREQ (string, "upper") \
1720	\|\| STREQ (string, "lower") \|\| STREQ (string, "digit") \
1721	\|\| STREQ (string, "alnum") \|\| STREQ (string, "xdigit") \
1722	\|\| STREQ (string, "space") \|\| STREQ (string, "print") \
1723	\|\| STREQ (string, "punct") \|\| STREQ (string, "graph") \
1724	\|\| STREQ (string, "cntrl") \|\| STREQ (string, "blank"))
1725	#endif
1726
1727	#ifndef MATCH_MAY_ALLOCATE
1728
1729	/* If we cannot allocate large objects within re_match_2_internal,
1730	we make the fail stack and register vectors global.
1731	The fail stack, we grow to the maximum size when a regexp
1732	is compiled.
1733	The register vectors, we adjust in size each time we
1734	compile a regexp, according to the number of registers it needs. */
1735
1736	static fail_stack_type fail_stack;
1737
1738	/* Size with which the following vectors are currently allocated.
1739	That is so we can make them bigger as needed,
1740	but never make them smaller. */
1741	static int regs_allocated_size;
1742
1743	static const char regstart, regend;
1744	static const char old_regstart, old_regend;
1745	static const char best_regstart, best_regend;
1746	static register_info_type *reg_info;
1747	static const char **reg_dummy;
1748	static register_info_type *reg_info_dummy;
1749
1750	/* Make the register vectors big enough for NUM_REGS registers,
1751	but don't make them smaller. */
1752
1753	static
1754	regex_grow_registers (num_regs)
1755	int num_regs;
1756	{
1757	if (num_regs > regs_allocated_size)
1758	{
1759	RETALLOC_IF (regstart, num_regs, const char *);
1760	RETALLOC_IF (regend, num_regs, const char *);
1761	RETALLOC_IF (old_regstart, num_regs, const char *);
1762	RETALLOC_IF (old_regend, num_regs, const char *);
1763	RETALLOC_IF (best_regstart, num_regs, const char *);
1764	RETALLOC_IF (best_regend, num_regs, const char *);
1765	RETALLOC_IF (reg_info, num_regs, register_info_type);
1766	RETALLOC_IF (reg_dummy, num_regs, const char *);
1767	RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
1768
1769	regs_allocated_size = num_regs;
1770	}
1771	}
1772
1773	#endif /* not MATCH_MAY_ALLOCATE */
1774
1775	static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
1776	compile_stack,
1777	regnum_t regnum));
1778
1779	/* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1780	Returns one of error codes defined in `regex.h', or zero for success.
1781
1782	Assumes the `allocated' (and perhaps `buffer') and `translate'
1783	fields are set in BUFP on entry.
1784
1785	If it succeeds, results are put in BUFP (if it returns an error, the
1786	contents of BUFP are undefined):
1787	`buffer' is the compiled pattern;
1788	`syntax' is set to SYNTAX;
1789	`used' is set to the length of the compiled pattern;
1790	`fastmap_accurate' is zero;
1791	`re_nsub' is the number of subexpressions in PATTERN;
1792	`not_bol' and `not_eol' are zero;
1793
1794	The `fastmap' and `newline_anchor' fields are neither
1795	examined nor set. */
1796
1797	/* Return, freeing storage we allocated. */
1798	#define FREE_STACK_RETURN(value) \
1799	return (free (compile_stack.stack), value)
1800
1801	static reg_errcode_t
1802	regex_compile (pattern, size, syntax, bufp)
1803	const char *pattern;
1804	size_t size;
1805	reg_syntax_t syntax;
1806	struct re_pattern_buffer *bufp;
1807	{
1808	/* We fetch characters from PATTERN here. Even though PATTERN is
1809	`char *' (i.e., signed), we declare these variables as unsigned, so
1810	they can be reliably used as array indices. */
1811	register unsigned char c, c1;
1812
1813	/* A random temporary spot in PATTERN. */
1814	const char *p1;
1815
1816	/* Points to the end of the buffer, where we should append. */
1817	register unsigned char *b;
1818
1819	/* Keeps track of unclosed groups. */
1820	compile_stack_type compile_stack;
1821
1822	/* Points to the current (ending) position in the pattern. */
1823	const char *p = pattern;
1824	const char *pend = pattern + size;
1825
1826	/* How to translate the characters in the pattern. */
1827	RE_TRANSLATE_TYPE translate = bufp->translate;
1828
1829	/* Address of the count-byte of the most recently inserted `exactn'
1830	command. This makes it possible to tell if a new exact-match
1831	character can be added to that command or if the character requires
1832	a new `exactn' command. */
1833	unsigned char *pending_exact = 0;
1834
1835	/* Address of start of the most recently finished expression.
1836	This tells, e.g., postfix * where to find the start of its
1837	operand. Reset at the beginning of groups and alternatives. */
1838	unsigned char *laststart = 0;
1839
1840	/* Address of beginning of regexp, or inside of last group. */
1841	unsigned char *begalt;
1842
1843	/* Place in the uncompiled pattern (i.e., the {) to
1844	which to go back if the interval is invalid. */
1845	const char *beg_interval;
1846
1847	/* Address of the place where a forward jump should go to the end of
1848	the containing expression. Each alternative of an `or' -- except the
1849	last -- ends with a forward jump of this sort. */
1850	unsigned char *fixup_alt_jump = 0;
1851
1852	/* Counts open-groups as they are encountered. Remembered for the
1853	matching close-group on the compile stack, so the same register
1854	number is put in the stop_memory as the start_memory. */
1855	regnum_t regnum = 0;
1856
1857	#ifdef DEBUG
1858	DEBUG_PRINT1 ("\nCompiling pattern: ");
1859	if (debug)
1860	{
1861	unsigned debug_count;
1862
1863	for (debug_count = 0; debug_count < size; debug_count++)
1864	putchar (pattern[debug_count]);
1865	putchar ('\n');
1866	}
1867	#endif /* DEBUG */
1868
1869	/* Initialize the compile stack. */
1870	compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1871	if (compile_stack.stack == NULL)
1872	return REG_ESPACE;
1873
1874	compile_stack.size = INIT_COMPILE_STACK_SIZE;
1875	compile_stack.avail = 0;
1876
1877	/* Initialize the pattern buffer. */
1878	bufp->syntax = syntax;
1879	bufp->fastmap_accurate = 0;
1880	bufp->not_bol = bufp->not_eol = 0;
1881
1882	/* Set `used' to zero, so that if we return an error, the pattern
1883	printer (for debugging) will think there's no pattern. We reset it
1884	at the end. */
1885	bufp->used = 0;
1886
1887	/* Always count groups, whether or not bufp->no_sub is set. */
1888	bufp->re_nsub = 0;
1889
1890	#if !defined (emacs) && !defined (SYNTAX_TABLE)
1891	/* Initialize the syntax table. */
1892	init_syntax_once ();
1893	#endif
1894
1895	if (bufp->allocated == 0)
1896	{
1897	if (bufp->buffer)
1898	{ /* If zero allocated, but buffer is non-null, try to realloc
1899	enough space. This loses if buffer's address is bogus, but
1900	that is the user's responsibility. */
1901	RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1902	}
1903	else
1904	{ /* Caller did not allocate a buffer. Do it for them. */
1905	bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1906	}
1907	if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
1908
1909	bufp->allocated = INIT_BUF_SIZE;
1910	}
1911
1912	begalt = b = bufp->buffer;
1913
1914	/* Loop through the uncompiled pattern until we're at the end. */
1915	while (p != pend)
1916	{
1917	PATFETCH (c);
1918
1919	switch (c)
1920	{
1921	case '^':
1922	{
1923	if ( /* If at start of pattern, it's an operator. */
1924	p == pattern + 1
1925	/* If context independent, it's an operator. */
1926	\|\| syntax & RE_CONTEXT_INDEP_ANCHORS
1927	/* Otherwise, depends on what's come before. */
1928	\|\| at_begline_loc_p (pattern, p, syntax))
1929	BUF_PUSH (begline);
1930	else
1931	goto normal_char;
1932	}
1933	break;
1934
1935
1936	case '$':
1937	{
1938	if ( /* If at end of pattern, it's an operator. */
1939	p == pend
1940	/* If context independent, it's an operator. */
1941	\|\| syntax & RE_CONTEXT_INDEP_ANCHORS
1942	/* Otherwise, depends on what's next. */
1943	\|\| at_endline_loc_p (p, pend, syntax))
1944	BUF_PUSH (endline);
1945	else
1946	goto normal_char;
1947	}
1948	break;
1949
1950
1951	case '+':
1952	case '?':
1953	if ((syntax & RE_BK_PLUS_QM)
1954	\|\| (syntax & RE_LIMITED_OPS))
1955	goto normal_char;
1956	handle_plus:
1957	case '*':
1958	/* If there is no previous pattern... */
1959	if (!laststart)
1960	{
1961	if (syntax & RE_CONTEXT_INVALID_OPS)
1962	FREE_STACK_RETURN (REG_BADRPT);
1963	else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1964	goto normal_char;
1965	}
1966
1967	{
1968	/* Are we optimizing this jump? */
1969	boolean keep_string_p = false;
1970
1971	/* 1 means zero (many) matches is allowed. */
1972	char zero_times_ok = 0, many_times_ok = 0;
1973
1974	/* If there is a sequence of repetition chars, collapse it
1975	down to just one (the right one). We can't combine
1976	interval operators with these because of, e.g., `a{2}*',
1977	which should only match an even number of `a's. */
1978
1979	for (;;)
1980	{
1981	zero_times_ok \|= c != '+';
1982	many_times_ok \|= c != '?';
1983
1984	if (p == pend)
1985	break;
1986
1987	PATFETCH (c);
1988
1989	if (c == '*'
1990	\|\| (!(syntax & RE_BK_PLUS_QM) && (c == '+' \|\| c == '?')))
1991	;
1992
1993	else if (syntax & RE_BK_PLUS_QM && c == '\\')
1994	{
1995	if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1996
1997	PATFETCH (c1);
1998	if (!(c1 == '+' \|\| c1 == '?'))
1999	{
2000	PATUNFETCH;
2001	PATUNFETCH;
2002	break;
2003	}
2004
2005	c = c1;
2006	}
2007	else
2008	{
2009	PATUNFETCH;
2010	break;
2011	}
2012
2013	/* If we get here, we found another repeat character. */
2014	}
2015
2016	/* Star, etc. applied to an empty pattern is equivalent
2017	to an empty pattern. */
2018	if (!laststart)
2019	break;
2020
2021	/* Now we know whether or not zero matches is allowed
2022	and also whether or not two or more matches is allowed. */
2023	if (many_times_ok)
2024	{ /* More than one repetition is allowed, so put in at the
2025	end a backward relative jump from `b' to before the next
2026	jump we're going to put in below (which jumps from
2027	laststart to after this jump).
2028
2029	But if we are at the `' in the exact sequence `.\n',
2030	insert an unconditional jump backwards to the .,
2031	instead of the beginning of the loop. This way we only
2032	push a failure point once, instead of every time
2033	through the loop. */
2034	assert (p - 1 > pattern);
2035
2036	/* Allocate the space for the jump. */
2037	GET_BUFFER_SPACE (3);
2038
2039	/* We know we are not at the first character of the pattern,
2040	because laststart was nonzero. And we've already
2041	incremented `p', by the way, to be the character after
2042	the `*'. Do we have to do something analogous here
2043	for null bytes, because of RE_DOT_NOT_NULL? */
2044	if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
2045	&& zero_times_ok
2046	&& p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
2047	&& !(syntax & RE_DOT_NEWLINE))
2048	{ /* We have .\n. /
2049	STORE_JUMP (jump, b, laststart);
2050	keep_string_p = true;
2051	}
2052	else
2053	/* Anything else. */
2054	STORE_JUMP (maybe_pop_jump, b, laststart - 3);
2055
2056	/* We've added more stuff to the buffer. */
2057	b += 3;
2058	}
2059
2060	/* On failure, jump from laststart to b + 3, which will be the
2061	end of the buffer after this jump is inserted. */
2062	GET_BUFFER_SPACE (3);
2063	INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
2064	: on_failure_jump,
2065	laststart, b + 3);
2066	pending_exact = 0;
2067	b += 3;
2068
2069	if (!zero_times_ok)
2070	{
2071	/* At least one repetition is required, so insert a
2072	`dummy_failure_jump' before the initial
2073	`on_failure_jump' instruction of the loop. This
2074	effects a skip over that instruction the first time
2075	we hit that loop. */
2076	GET_BUFFER_SPACE (3);
2077	INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
2078	b += 3;
2079	}
2080	}
2081	break;
2082
2083
2084	case '.':
2085	laststart = b;
2086	BUF_PUSH (anychar);
2087	break;
2088
2089
2090	case '[':
2091	{
2092	boolean had_char_class = false;
2093
2094	if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2095
2096	/* Ensure that we have enough space to push a charset: the
2097	opcode, the length count, and the bitset; 34 bytes in all. */
2098	GET_BUFFER_SPACE (34);
2099
2100	laststart = b;
2101
2102	/* We test `*p == '^' twice, instead of using an if
2103	statement, so we only need one BUF_PUSH. */
2104	BUF_PUSH (*p == '^' ? charset_not : charset);
2105	if (*p == '^')
2106	p++;
2107
2108	/* Remember the first position in the bracket expression. */
2109	p1 = p;
2110
2111	/* Push the number of bytes in the bitmap. */
2112	BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
2113
2114	/* Clear the whole map. */
2115	bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
2116
2117	/* charset_not matches newline according to a syntax bit. */
2118	if ((re_opcode_t) b[-2] == charset_not
2119	&& (syntax & RE_HAT_LISTS_NOT_NEWLINE))
2120	SET_LIST_BIT ('\n');
2121
2122	/* Read in characters and ranges, setting map bits. */
2123	for (;;)
2124	{
2125	if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2126
2127	PATFETCH (c);
2128
2129	/* \ might escape characters inside [...] and [^...]. */
2130	if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
2131	{
2132	if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2133
2134	PATFETCH (c1);
2135	SET_LIST_BIT (c1);
2136	continue;
2137	}
2138
2139	/* Could be the end of the bracket expression. If it's
2140	not (i.e., when the bracket expression is `[]' so
2141	far), the ']' character bit gets set way below. */
2142	if (c == ']' && p != p1 + 1)
2143	break;
2144
2145	/* Look ahead to see if it's a range when the last thing
2146	was a character class. */
2147	if (had_char_class && c == '-' && *p != ']')
2148	FREE_STACK_RETURN (REG_ERANGE);
2149
2150	/* Look ahead to see if it's a range when the last thing
2151	was a character: if this is a hyphen not at the
2152	beginning or the end of a list, then it's the range
2153	operator. */
2154	if (c == '-'
2155	&& !(p - 2 >= pattern && p[-2] == '[')
2156	&& !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
2157	&& *p != ']')
2158	{
2159	reg_errcode_t ret
2160	= compile_range (&p, pend, translate, syntax, b);
2161	if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2162	}
2163
2164	else if (p[0] == '-' && p[1] != ']')
2165	{ /* This handles ranges made up of characters only. */
2166	reg_errcode_t ret;
2167
2168	/* Move past the `-'. */
2169	PATFETCH (c1);
2170
2171	ret = compile_range (&p, pend, translate, syntax, b);
2172	if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2173	}
2174
2175	/* See if we're at the beginning of a possible character
2176	class. */
2177
2178	else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
2179	{ /* Leave room for the null. */
2180	char str[CHAR_CLASS_MAX_LENGTH + 1];
2181
2182	PATFETCH (c);
2183	c1 = 0;
2184
2185	/* If pattern is `[[:'. */
2186	if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2187
2188	for (;;)
2189	{
2190	PATFETCH (c);
2191	if (c == ':' \|\| c == ']' \|\| p == pend
2192	\|\| c1 == CHAR_CLASS_MAX_LENGTH)
2193	break;
2194	str[c1++] = c;
2195	}
2196	str[c1] = '\0';
2197
2198	/* If isn't a word bracketed by `[:' and:`]':
2199	undo the ending character, the letters, and leave
2200	the leading `:' and `[' (but set bits for them). */
2201	if (c == ':' && *p == ']')
2202	{
2203	#if defined _LIBC \|\| (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
2204	boolean is_lower = STREQ (str, "lower");
2205	boolean is_upper = STREQ (str, "upper");
2206	wctype_t wt;
2207	int ch;
2208
2209	wt = wctype (str);
2210	if (wt == 0)
2211	FREE_STACK_RETURN (REG_ECTYPE);
2212
2213	/* Throw away the ] at the end of the character
2214	class. */
2215	PATFETCH (c);
2216
2217	if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2218
2219	for (ch = 0; ch < 1 << BYTEWIDTH; ++ch)
2220	{
2221	if (iswctype (btowc (ch), wt))
2222	SET_LIST_BIT (ch);
2223
2224	if (translate && (is_upper \|\| is_lower)
2225	&& (ISUPPER (ch) \|\| ISLOWER (ch)))
2226	SET_LIST_BIT (ch);
2227	}
2228
2229	had_char_class = true;
2230	#else
2231	int ch;
2232	boolean is_alnum = STREQ (str, "alnum");
2233	boolean is_alpha = STREQ (str, "alpha");
2234	boolean is_blank = STREQ (str, "blank");
2235	boolean is_cntrl = STREQ (str, "cntrl");
2236	boolean is_digit = STREQ (str, "digit");
2237	boolean is_graph = STREQ (str, "graph");
2238	boolean is_lower = STREQ (str, "lower");
2239	boolean is_print = STREQ (str, "print");
2240	boolean is_punct = STREQ (str, "punct");
2241	boolean is_space = STREQ (str, "space");
2242	boolean is_upper = STREQ (str, "upper");
2243	boolean is_xdigit = STREQ (str, "xdigit");
2244
2245	if (!IS_CHAR_CLASS (str))
2246	FREE_STACK_RETURN (REG_ECTYPE);
2247
2248	/* Throw away the ] at the end of the character
2249	class. */
2250	PATFETCH (c);
2251
2252	if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2253
2254	for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
2255	{
2256	/* This was split into 3 if's to
2257	avoid an arbitrary limit in some compiler. */
2258	if ( (is_alnum && ISALNUM (ch))
2259	\|\| (is_alpha && ISALPHA (ch))
2260	\|\| (is_blank && ISBLANK (ch))
2261	\|\| (is_cntrl && ISCNTRL (ch)))
2262	SET_LIST_BIT (ch);
2263	if ( (is_digit && ISDIGIT (ch))
2264	\|\| (is_graph && ISGRAPH (ch))
2265	\|\| (is_lower && ISLOWER (ch))
2266	\|\| (is_print && ISPRINT (ch)))
2267	SET_LIST_BIT (ch);
2268	if ( (is_punct && ISPUNCT (ch))
2269	\|\| (is_space && ISSPACE (ch))
2270	\|\| (is_upper && ISUPPER (ch))
2271	\|\| (is_xdigit && ISXDIGIT (ch)))
2272	SET_LIST_BIT (ch);
2273	if ( translate && (is_upper \|\| is_lower)
2274	&& (ISUPPER (ch) \|\| ISLOWER (ch)))
2275	SET_LIST_BIT (ch);
2276	}
2277	had_char_class = true;
2278	#endif /* libc \|\| wctype.h */
2279	}
2280	else
2281	{
2282	c1++;
2283	while (c1--)
2284	PATUNFETCH;
2285	SET_LIST_BIT ('[');
2286	SET_LIST_BIT (':');
2287	had_char_class = false;
2288	}
2289	}
2290	else
2291	{
2292	had_char_class = false;
2293	SET_LIST_BIT (c);
2294	}
2295	}
2296
2297	/* Discard any (non)matching list bytes that are all 0 at the
2298	end of the map. Decrease the map-length byte too. */
2299	while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
2300	b[-1]--;
2301	b += b[-1];
2302	}
2303	break;
2304
2305
2306	case '(':
2307	if (syntax & RE_NO_BK_PARENS)
2308	goto handle_open;
2309	else
2310	goto normal_char;
2311
2312
2313	case ')':
2314	if (syntax & RE_NO_BK_PARENS)
2315	goto handle_close;
2316	else
2317	goto normal_char;
2318
2319
2320	case '\n':
2321	if (syntax & RE_NEWLINE_ALT)
2322	goto handle_alt;
2323	else
2324	goto normal_char;
2325
2326
2327	case '\|':
2328	if (syntax & RE_NO_BK_VBAR)
2329	goto handle_alt;
2330	else
2331	goto normal_char;
2332
2333
2334	case '{':
2335	if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
2336	goto handle_interval;
2337	else
2338	goto normal_char;
2339
2340
2341	case '\\':
2342	if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2343
2344	/* Do not translate the character after the \, so that we can
2345	distinguish, e.g., \B from \b, even if we normally would
2346	translate, e.g., B to b. */
2347	PATFETCH_RAW (c);
2348
2349	switch (c)
2350	{
2351	case '(':
2352	if (syntax & RE_NO_BK_PARENS)
2353	goto normal_backslash;
2354
2355	handle_open:
2356	bufp->re_nsub++;
2357	regnum++;
2358
2359	if (COMPILE_STACK_FULL)
2360	{
2361	RETALLOC (compile_stack.stack, compile_stack.size << 1,
2362	compile_stack_elt_t);
2363	if (compile_stack.stack == NULL) return REG_ESPACE;
2364
2365	compile_stack.size <<= 1;
2366	}
2367
2368	/* These are the values to restore when we hit end of this
2369	group. They are all relative offsets, so that if the
2370	whole pattern moves because of realloc, they will still
2371	be valid. */
2372	COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2373	COMPILE_STACK_TOP.fixup_alt_jump
2374	= fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2375	COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2376	COMPILE_STACK_TOP.regnum = regnum;
2377
2378	/* We will eventually replace the 0 with the number of
2379	groups inner to this one. But do not push a
2380	start_memory for groups beyond the last one we can
2381	represent in the compiled pattern. */
2382	if (regnum <= MAX_REGNUM)
2383	{
2384	COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2385	BUF_PUSH_3 (start_memory, regnum, 0);
2386	}
2387
2388	compile_stack.avail++;
2389
2390	fixup_alt_jump = 0;
2391	laststart = 0;
2392	begalt = b;
2393	/* If we've reached MAX_REGNUM groups, then this open
2394	won't actually generate any code, so we'll have to
2395	clear pending_exact explicitly. */
2396	pending_exact = 0;
2397	break;
2398
2399
2400	case ')':
2401	if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
2402
2403	if (COMPILE_STACK_EMPTY)
2404	if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2405	goto normal_backslash;
2406	else
2407	FREE_STACK_RETURN (REG_ERPAREN);
2408
2409	handle_close:
2410	if (fixup_alt_jump)
2411	{ /* Push a dummy failure point at the end of the
2412	alternative for a possible future
2413	`pop_failure_jump' to pop. See comments at
2414	`push_dummy_failure' in `re_match_2'. */
2415	BUF_PUSH (push_dummy_failure);
2416
2417	/* We allocated space for this jump when we assigned
2418	to `fixup_alt_jump', in the `handle_alt' case below. */
2419	STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2420	}
2421
2422	/* See similar code for backslashed left paren above. */
2423	if (COMPILE_STACK_EMPTY)
2424	if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2425	goto normal_char;
2426	else
2427	FREE_STACK_RETURN (REG_ERPAREN);
2428
2429	/* Since we just checked for an empty stack above, this
2430	``can't happen''. */
2431	assert (compile_stack.avail != 0);
2432	{
2433	/* We don't just want to restore into `regnum', because
2434	later groups should continue to be numbered higher,
2435	as in `(ab)c(de)' -- the second group is #2. */
2436	regnum_t this_group_regnum;
2437
2438	compile_stack.avail--;
2439	begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2440	fixup_alt_jump
2441	= COMPILE_STACK_TOP.fixup_alt_jump
2442	? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
2443	: 0;
2444	laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2445	this_group_regnum = COMPILE_STACK_TOP.regnum;
2446	/* If we've reached MAX_REGNUM groups, then this open
2447	won't actually generate any code, so we'll have to
2448	clear pending_exact explicitly. */
2449	pending_exact = 0;
2450
2451	/* We're at the end of the group, so now we know how many
2452	groups were inside this one. */
2453	if (this_group_regnum <= MAX_REGNUM)
2454	{
2455	unsigned char *inner_group_loc
2456	= bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2457
2458	*inner_group_loc = regnum - this_group_regnum;
2459	BUF_PUSH_3 (stop_memory, this_group_regnum,
2460	regnum - this_group_regnum);
2461	}
2462	}
2463	break;
2464
2465
2466	case '\|': /* `\\|'. */
2467	if (syntax & RE_LIMITED_OPS \|\| syntax & RE_NO_BK_VBAR)
2468	goto normal_backslash;
2469	handle_alt:
2470	if (syntax & RE_LIMITED_OPS)
2471	goto normal_char;
2472
2473	/* Insert before the previous alternative a jump which
2474	jumps to this alternative if the former fails. */
2475	GET_BUFFER_SPACE (3);
2476	INSERT_JUMP (on_failure_jump, begalt, b + 6);
2477	pending_exact = 0;
2478	b += 3;
2479
2480	/* The alternative before this one has a jump after it
2481	which gets executed if it gets matched. Adjust that
2482	jump so it will jump to this alternative's analogous
2483	jump (put in below, which in turn will jump to the next
2484	(if any) alternative's such jump, etc.). The last such
2485	jump jumps to the correct final destination. A picture:
2486	_____ _____
2487	\| \| \| \|
2488	\| v \| v
2489	a \| b \| c
2490
2491	If we are at `b', then fixup_alt_jump right now points to a
2492	three-byte space after `a'. We'll put in the jump, set
2493	fixup_alt_jump to right after `b', and leave behind three
2494	bytes which we'll fill in when we get to after `c'. */
2495
2496	if (fixup_alt_jump)
2497	STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2498
2499	/* Mark and leave space for a jump after this alternative,
2500	to be filled in later either by next alternative or
2501	when know we're at the end of a series of alternatives. */
2502	fixup_alt_jump = b;
2503	GET_BUFFER_SPACE (3);
2504	b += 3;
2505
2506	laststart = 0;
2507	begalt = b;
2508	break;
2509
2510
2511	case '{':
2512	/* If \{ is a literal. */
2513	if (!(syntax & RE_INTERVALS)
2514	/* If we're at `\{' and it's not the open-interval
2515	operator. */
2516	\|\| ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2517	\|\| (p - 2 == pattern && p == pend))
2518	goto normal_backslash;
2519
2520	handle_interval:
2521	{
2522	/* If got here, then the syntax allows intervals. */
2523
2524	/* At least (most) this many matches must be made. */
2525	int lower_bound = -1, upper_bound = -1;
2526
2527	beg_interval = p - 1;
2528
2529	if (p == pend)
2530	{
2531	if (syntax & RE_NO_BK_BRACES)
2532	goto unfetch_interval;
2533	else
2534	FREE_STACK_RETURN (REG_EBRACE);
2535	}
2536
2537	GET_UNSIGNED_NUMBER (lower_bound);
2538
2539	if (c == ',')
2540	{
2541	GET_UNSIGNED_NUMBER (upper_bound);
2542	if (upper_bound < 0) upper_bound = RE_DUP_MAX;
2543	}
2544	else
2545	/* Interval such as `{1}' => match exactly once. */
2546	upper_bound = lower_bound;
2547
2548	if (lower_bound < 0 \|\| upper_bound > RE_DUP_MAX
2549	\|\| lower_bound > upper_bound)
2550	{
2551	if (syntax & RE_NO_BK_BRACES)
2552	goto unfetch_interval;
2553	else
2554	FREE_STACK_RETURN (REG_BADBR);
2555	}
2556
2557	if (!(syntax & RE_NO_BK_BRACES))
2558	{
2559	if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
2560
2561	PATFETCH (c);
2562	}
2563
2564	if (c != '}')
2565	{
2566	if (syntax & RE_NO_BK_BRACES)
2567	goto unfetch_interval;
2568	else
2569	FREE_STACK_RETURN (REG_BADBR);
2570	}
2571
2572	/* We just parsed a valid interval. */
2573
2574	/* If it's invalid to have no preceding re. */
2575	if (!laststart)
2576	{
2577	if (syntax & RE_CONTEXT_INVALID_OPS)
2578	FREE_STACK_RETURN (REG_BADRPT);
2579	else if (syntax & RE_CONTEXT_INDEP_OPS)
2580	laststart = b;
2581	else
2582	goto unfetch_interval;
2583	}
2584
2585	/* If the upper bound is zero, don't want to succeed at
2586	all; jump from `laststart' to `b + 3', which will be
2587	the end of the buffer after we insert the jump. */
2588	if (upper_bound == 0)
2589	{
2590	GET_BUFFER_SPACE (3);
2591	INSERT_JUMP (jump, laststart, b + 3);
2592	b += 3;
2593	}
2594
2595	/* Otherwise, we have a nontrivial interval. When
2596	we're all done, the pattern will look like:
2597	set_number_at <jump count> <upper bound>
2598	set_number_at <succeed_n count> <lower bound>
2599	succeed_n <after jump addr> <succeed_n count>
2600	<body of loop>
2601	jump_n <succeed_n addr> <jump count>
2602	(The upper bound and `jump_n' are omitted if
2603	`upper_bound' is 1, though.) */
2604	else
2605	{ /* If the upper bound is > 1, we need to insert
2606	more at the end of the loop. */
2607	unsigned nbytes = 10 + (upper_bound > 1) * 10;
2608
2609	GET_BUFFER_SPACE (nbytes);
2610
2611	/* Initialize lower bound of the `succeed_n', even
2612	though it will be set during matching by its
2613	attendant `set_number_at' (inserted next),
2614	because `re_compile_fastmap' needs to know.
2615	Jump to the `jump_n' we might insert below. */
2616	INSERT_JUMP2 (succeed_n, laststart,
2617	b + 5 + (upper_bound > 1) * 5,
2618	lower_bound);
2619	b += 5;
2620
2621	/* Code to initialize the lower bound. Insert
2622	before the `succeed_n'. The `5' is the last two
2623	bytes of this `set_number_at', plus 3 bytes of
2624	the following `succeed_n'. */
2625	insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2626	b += 5;
2627
2628	if (upper_bound > 1)
2629	{ /* More than one repetition is allowed, so
2630	append a backward jump to the `succeed_n'
2631	that starts this interval.
2632
2633	When we've reached this during matching,
2634	we'll have matched the interval once, so
2635	jump back only `upper_bound - 1' times. */
2636	STORE_JUMP2 (jump_n, b, laststart + 5,
2637	upper_bound - 1);
2638	b += 5;
2639
2640	/* The location we want to set is the second
2641	parameter of the `jump_n'; that is `b-2' as
2642	an absolute address. `laststart' will be
2643	the `set_number_at' we're about to insert;
2644	`laststart+3' the number to set, the source
2645	for the relative address. But we are
2646	inserting into the middle of the pattern --
2647	so everything is getting moved up by 5.
2648	Conclusion: (b - 2) - (laststart + 3) + 5,
2649	i.e., b - laststart.
2650
2651	We insert this at the beginning of the loop
2652	so that if we fail during matching, we'll
2653	reinitialize the bounds. */
2654	insert_op2 (set_number_at, laststart, b - laststart,
2655	upper_bound - 1, b);
2656	b += 5;
2657	}
2658	}
2659	pending_exact = 0;
2660	beg_interval = NULL;
2661	}
2662	break;
2663
2664	unfetch_interval:
2665	/* If an invalid interval, match the characters as literals. */
2666	assert (beg_interval);
2667	p = beg_interval;
2668	beg_interval = NULL;
2669
2670	/* normal_char and normal_backslash need `c'. */
2671	PATFETCH (c);
2672
2673	if (!(syntax & RE_NO_BK_BRACES))
2674	{
2675	if (p > pattern && p[-1] == '\\')
2676	goto normal_backslash;
2677	}
2678	goto normal_char;
2679
2680	#ifdef emacs
2681	/* There is no way to specify the before_dot and after_dot
2682	operators. rms says this is ok. --karl */
2683	case '=':
2684	BUF_PUSH (at_dot);
2685	break;
2686
2687	case 's':
2688	laststart = b;
2689	PATFETCH (c);
2690	BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2691	break;
2692
2693	case 'S':
2694	laststart = b;
2695	PATFETCH (c);
2696	BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2697	break;
2698	#endif /* emacs */
2699
2700
2701	case 'w':
2702	if (re_syntax_options & RE_NO_GNU_OPS)
2703	goto normal_char;
2704	laststart = b;
2705	BUF_PUSH (wordchar);
2706	break;
2707
2708
2709	case 'W':
2710	if (re_syntax_options & RE_NO_GNU_OPS)
2711	goto normal_char;
2712	laststart = b;
2713	BUF_PUSH (notwordchar);
2714	break;
2715
2716
2717	case '<':
2718	if (re_syntax_options & RE_NO_GNU_OPS)
2719	goto normal_char;
2720	BUF_PUSH (wordbeg);
2721	break;
2722
2723	case '>':
2724	if (re_syntax_options & RE_NO_GNU_OPS)
2725	goto normal_char;
2726	BUF_PUSH (wordend);
2727	break;
2728
2729	case 'b':
2730	if (re_syntax_options & RE_NO_GNU_OPS)
2731	goto normal_char;
2732	BUF_PUSH (wordbound);
2733	break;
2734
2735	case 'B':
2736	if (re_syntax_options & RE_NO_GNU_OPS)
2737	goto normal_char;
2738	BUF_PUSH (notwordbound);
2739	break;
2740
2741	case '`':
2742	if (re_syntax_options & RE_NO_GNU_OPS)
2743	goto normal_char;
2744	BUF_PUSH (begbuf);
2745	break;
2746
2747	case '\'':
2748	if (re_syntax_options & RE_NO_GNU_OPS)
2749	goto normal_char;
2750	BUF_PUSH (endbuf);
2751	break;
2752
2753	case '1': case '2': case '3': case '4': case '5':
2754	case '6': case '7': case '8': case '9':
2755	if (syntax & RE_NO_BK_REFS)
2756	goto normal_char;
2757
2758	c1 = c - '0';
2759
2760	if (c1 > regnum)
2761	FREE_STACK_RETURN (REG_ESUBREG);
2762
2763	/* Can't back reference to a subexpression if inside of it. */
2764	if (group_in_compile_stack (compile_stack, (regnum_t) c1))
2765	goto normal_char;
2766
2767	laststart = b;
2768	BUF_PUSH_2 (duplicate, c1);
2769	break;
2770
2771
2772	case '+':
2773	case '?':
2774	if (syntax & RE_BK_PLUS_QM)
2775	goto handle_plus;
2776	else
2777	goto normal_backslash;
2778
2779	default:
2780	normal_backslash:
2781	/* You might think it would be useful for \ to mean
2782	not to translate; but if we don't translate it
2783	it will never match anything. */
2784	c = TRANSLATE (c);
2785	goto normal_char;
2786	}
2787	break;
2788
2789
2790	default:
2791	/* Expects the character in `c'. */
2792	normal_char:
2793	/* If no exactn currently being built. */
2794	if (!pending_exact
2795
2796	/* If last exactn not at current position. */
2797	\|\| pending_exact + *pending_exact + 1 != b
2798
2799	/* We have only one byte following the exactn for the count. */
2800	\|\| *pending_exact == (1 << BYTEWIDTH) - 1
2801
2802	/* If followed by a repetition operator. */
2803	\|\| p == '' \|\| *p == '^'
2804	\|\| ((syntax & RE_BK_PLUS_QM)
2805	? *p == '\\' && (p[1] == '+' \|\| p[1] == '?')
2806	: (p == '+' \|\| p == '?'))
2807	\|\| ((syntax & RE_INTERVALS)
2808	&& ((syntax & RE_NO_BK_BRACES)
2809	? *p == '{'
2810	: (p[0] == '\\' && p[1] == '{'))))
2811	{
2812	/* Start building a new exactn. */
2813
2814	laststart = b;
2815
2816	BUF_PUSH_2 (exactn, 0);
2817	pending_exact = b - 1;
2818	}
2819
2820	BUF_PUSH (c);
2821	(*pending_exact)++;
2822	break;
2823	} /* switch (c) */
2824	} /* while p != pend */
2825
2826
2827	/* Through the pattern now. */
2828
2829	if (fixup_alt_jump)
2830	STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2831
2832	if (!COMPILE_STACK_EMPTY)
2833	FREE_STACK_RETURN (REG_EPAREN);
2834
2835	/* If we don't want backtracking, force success
2836	the first time we reach the end of the compiled pattern. */
2837	if (syntax & RE_NO_POSIX_BACKTRACKING)
2838	BUF_PUSH (succeed);
2839
2840	free (compile_stack.stack);
2841
2842	/* We have succeeded; set the length of the buffer. */
2843	bufp->used = b - bufp->buffer;
2844
2845	#ifdef DEBUG
2846	if (debug)
2847	{
2848	DEBUG_PRINT1 ("\nCompiled pattern: \n");
2849	print_compiled_pattern (bufp);
2850	}
2851	#endif /* DEBUG */
2852
2853	#ifndef MATCH_MAY_ALLOCATE
2854	/* Initialize the failure stack to the largest possible stack. This
2855	isn't necessary unless we're trying to avoid calling alloca in
2856	the search and match routines. */
2857	{
2858	int num_regs = bufp->re_nsub + 1;
2859
2860	/* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2861	is strictly greater than re_max_failures, the largest possible stack
2862	is 2 * re_max_failures failure points. */
2863	if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
2864	{
2865	fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2866
2867	#ifdef emacs
2868	if (! fail_stack.stack)
2869	fail_stack.stack
2870	= (fail_stack_elt_t *) xmalloc (fail_stack.size
2871	* sizeof (fail_stack_elt_t));
2872	else
2873	fail_stack.stack
2874	= (fail_stack_elt_t *) xrealloc (fail_stack.stack,
2875	(fail_stack.size
2876	* sizeof (fail_stack_elt_t)));
2877	#else /* not emacs */
2878	if (! fail_stack.stack)
2879	fail_stack.stack
2880	= (fail_stack_elt_t *) malloc (fail_stack.size
2881	* sizeof (fail_stack_elt_t));
2882	else
2883	fail_stack.stack
2884	= (fail_stack_elt_t *) realloc (fail_stack.stack,
2885	(fail_stack.size
2886	* sizeof (fail_stack_elt_t)));
2887	#endif /* not emacs */
2888	}
2889
2890	regex_grow_registers (num_regs);
2891	}
2892	#endif /* not MATCH_MAY_ALLOCATE */
2893
2894	return REG_NOERROR;
2895	} /* regex_compile */
2896
2897	/* Subroutines for `regex_compile'. */
2898
2899	/* Store OP at LOC followed by two-byte integer parameter ARG. */
2900
2901	static void
2902	store_op1 (op, loc, arg)
2903	re_opcode_t op;
2904	unsigned char *loc;
2905	int arg;
2906	{
2907	*loc = (unsigned char) op;
2908	STORE_NUMBER (loc + 1, arg);
2909	}
2910
2911
2912	/* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2913
2914	static void
2915	store_op2 (op, loc, arg1, arg2)
2916	re_opcode_t op;
2917	unsigned char *loc;
2918	int arg1, arg2;
2919	{
2920	*loc = (unsigned char) op;
2921	STORE_NUMBER (loc + 1, arg1);
2922	STORE_NUMBER (loc + 3, arg2);
2923	}
2924
2925
2926	/* Copy the bytes from LOC to END to open up three bytes of space at LOC
2927	for OP followed by two-byte integer parameter ARG. */
2928
2929	static void
2930	insert_op1 (op, loc, arg, end)
2931	re_opcode_t op;
2932	unsigned char *loc;
2933	int arg;
2934	unsigned char *end;
2935	{
2936	register unsigned char *pfrom = end;
2937	register unsigned char *pto = end + 3;
2938
2939	while (pfrom != loc)
2940	--pto = --pfrom;
2941
2942	store_op1 (op, loc, arg);
2943	}
2944
2945
2946	/* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2947
2948	static void
2949	insert_op2 (op, loc, arg1, arg2, end)
2950	re_opcode_t op;
2951	unsigned char *loc;
2952	int arg1, arg2;
2953	unsigned char *end;
2954	{
2955	register unsigned char *pfrom = end;
2956	register unsigned char *pto = end + 5;
2957
2958	while (pfrom != loc)
2959	--pto = --pfrom;
2960
2961	store_op2 (op, loc, arg1, arg2);
2962	}
2963
2964
2965	/* P points to just after a ^ in PATTERN. Return true if that ^ comes
2966	after an alternative or a begin-subexpression. We assume there is at
2967	least one character before the ^. */
2968
2969	static boolean
2970	at_begline_loc_p (pattern, p, syntax)
2971	const char pattern, p;
2972	reg_syntax_t syntax;
2973	{
2974	const char *prev = p - 2;
2975	boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2976
2977	return
2978	/* After a subexpression? */
2979	(*prev == '(' && (syntax & RE_NO_BK_PARENS \|\| prev_prev_backslash))
2980	/* After an alternative? */
2981	\|\| (*prev == '\|' && (syntax & RE_NO_BK_VBAR \|\| prev_prev_backslash));
2982	}
2983
2984
2985	/* The dual of at_begline_loc_p. This one is for $. We assume there is
2986	at least one character after the $, i.e., `P < PEND'. */
2987
2988	static boolean
2989	at_endline_loc_p (p, pend, syntax)
2990	const char p, pend;
2991	reg_syntax_t syntax;
2992	{
2993	const char *next = p;
2994	boolean next_backslash = *next == '\\';
2995	const char *next_next = p + 1 < pend ? p + 1 : 0;
2996
2997	return
2998	/* Before a subexpression? */
2999	(syntax & RE_NO_BK_PARENS ? *next == ')'
3000	: next_backslash && next_next && *next_next == ')')
3001	/* Before an alternative? */
3002	\|\| (syntax & RE_NO_BK_VBAR ? *next == '\|'
3003	: next_backslash && next_next && *next_next == '\|');
3004	}
3005
3006
3007	/* Returns true if REGNUM is in one of COMPILE_STACK's elements and
3008	false if it's not. */
3009
3010	static boolean
3011	group_in_compile_stack (compile_stack, regnum)
3012	compile_stack_type compile_stack;
3013	regnum_t regnum;
3014	{
3015	int this_element;
3016
3017	for (this_element = compile_stack.avail - 1;
3018	this_element >= 0;
3019	this_element--)
3020	if (compile_stack.stack[this_element].regnum == regnum)
3021	return true;
3022
3023	return false;
3024	}
3025
3026
3027	/* Read the ending character of a range (in a bracket expression) from the
3028	uncompiled pattern *P_PTR (which ends at PEND). We assume the
3029	starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
3030	Then we set the translation of all bits between the starting and
3031	ending characters (inclusive) in the compiled pattern B.
3032
3033	Return an error code.
3034
3035	We use these short variable names so we can use the same macros as
3036	`regex_compile' itself. */
3037
3038	static reg_errcode_t
3039	compile_range (p_ptr, pend, translate, syntax, b)
3040	const char *p_ptr, pend;
3041	RE_TRANSLATE_TYPE translate;
3042	reg_syntax_t syntax;
3043	unsigned char *b;
3044	{
3045	unsigned this_char;
3046
3047	const char p = p_ptr;
3048	unsigned int range_start, range_end;
3049
3050	if (p == pend)
3051	return REG_ERANGE;
3052
3053	/* Even though the pattern is a signed `char *', we need to fetch
3054	with unsigned char *'s; if the high bit of the pattern character
3055	is set, the range endpoints will be negative if we fetch using a
3056	signed char *.
3057
3058	We also want to fetch the endpoints without translating them; the
3059	appropriate translation is done in the bit-setting loop below. */
3060	/* The SVR4 compiler on the 3B2 had trouble with unsigned const char . /
3061	range_start = ((const unsigned char *) p)[-2];
3062	range_end = ((const unsigned char *) p)[0];
3063
3064	/* Have to increment the pointer into the pattern string, so the
3065	caller isn't still at the ending character. */
3066	(*p_ptr)++;
3067
3068	/* If the start is after the end, the range is empty. */
3069	if (range_start > range_end)
3070	return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
3071
3072	/* Here we see why `this_char' has to be larger than an `unsigned
3073	char' -- the range is inclusive, so if `range_end' == 0xff
3074	(assuming 8-bit characters), we would otherwise go into an infinite
3075	loop, since all characters <= 0xff. */
3076	for (this_char = range_start; this_char <= range_end; this_char++)
3077	{
3078	SET_LIST_BIT (TRANSLATE (this_char));
3079	}
3080
3081	return REG_NOERROR;
3082	}
3083
3084	/* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
3085	BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
3086	characters can start a string that matches the pattern. This fastmap
3087	is used by re_search to skip quickly over impossible starting points.
3088
3089	The caller must supply the address of a (1 << BYTEWIDTH)-byte data
3090	area as BUFP->fastmap.
3091
3092	We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
3093	the pattern buffer.
3094
3095	Returns 0 if we succeed, -2 if an internal error. */
3096
3097	int
3098	re_compile_fastmap (bufp)
3099	struct re_pattern_buffer *bufp;
3100	{
3101	int j, k;
3102	#ifdef MATCH_MAY_ALLOCATE
3103	fail_stack_type fail_stack;
3104	#endif
3105	#ifndef REGEX_MALLOC
3106	char *destination;
3107	#endif
3108	/* We don't push any register information onto the failure stack. */
3109	unsigned num_regs = 0;
3110
3111	register char *fastmap = bufp->fastmap;
3112	unsigned char *pattern = bufp->buffer;
3113	unsigned char *p = pattern;
3114	register unsigned char *pend = pattern + bufp->used;
3115
3116	#ifdef REL_ALLOC
3117	/* This holds the pointer to the failure stack, when
3118	it is allocated relocatably. */
3119	fail_stack_elt_t *failure_stack_ptr;
3120	#endif
3121
3122	/* Assume that each path through the pattern can be null until
3123	proven otherwise. We set this false at the bottom of switch
3124	statement, to which we get only if a particular path doesn't
3125	match the empty string. */
3126	boolean path_can_be_null = true;
3127
3128	/* We aren't doing a `succeed_n' to begin with. */
3129	boolean succeed_n_p = false;
3130
3131	assert (fastmap != NULL && p != NULL);
3132
3133	INIT_FAIL_STACK ();
3134	bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
3135	bufp->fastmap_accurate = 1; /* It will be when we're done. */
3136	bufp->can_be_null = 0;
3137
3138	while (1)
3139	{
3140	if (p == pend \|\| *p == succeed)
3141	{
3142	/* We have reached the (effective) end of pattern. */
3143	if (!FAIL_STACK_EMPTY ())
3144	{
3145	bufp->can_be_null \|= path_can_be_null;
3146
3147	/* Reset for next path. */
3148	path_can_be_null = true;
3149
3150	p = fail_stack.stack[--fail_stack.avail].pointer;
3151
3152	continue;
3153	}
3154	else
3155	break;
3156	}
3157
3158	/* We should never be about to go beyond the end of the pattern. */
3159	assert (p < pend);
3160
3161	switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
3162	{
3163
3164	/* I guess the idea here is to simply not bother with a fastmap
3165	if a backreference is used, since it's too hard to figure out
3166	the fastmap for the corresponding group. Setting
3167	`can_be_null' stops `re_search_2' from using the fastmap, so
3168	that is all we do. */
3169	case duplicate:
3170	bufp->can_be_null = 1;
3171	goto done;
3172
3173
3174	/* Following are the cases which match a character. These end
3175	with `break'. */
3176
3177	case exactn:
3178	fastmap[p[1]] = 1;
3179	break;
3180
3181
3182	case charset:
3183	for (j = p++ BYTEWIDTH - 1; j >= 0; j--)
3184	if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
3185	fastmap[j] = 1;
3186	break;
3187
3188
3189	case charset_not:
3190	/* Chars beyond end of map must be allowed. */
3191	for (j = p BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
3192	fastmap[j] = 1;
3193
3194	for (j = p++ BYTEWIDTH - 1; j >= 0; j--)
3195	if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
3196	fastmap[j] = 1;
3197	break;
3198
3199
3200	case wordchar:
3201	for (j = 0; j < (1 << BYTEWIDTH); j++)
3202	if (SYNTAX (j) == Sword)
3203	fastmap[j] = 1;
3204	break;
3205
3206
3207	case notwordchar:
3208	for (j = 0; j < (1 << BYTEWIDTH); j++)
3209	if (SYNTAX (j) != Sword)
3210	fastmap[j] = 1;
3211	break;
3212
3213
3214	case anychar:
3215	{
3216	int fastmap_newline = fastmap['\n'];
3217
3218	/* `.' matches anything ... */
3219	for (j = 0; j < (1 << BYTEWIDTH); j++)
3220	fastmap[j] = 1;
3221
3222	/* ... except perhaps newline. */
3223	if (!(bufp->syntax & RE_DOT_NEWLINE))
3224	fastmap['\n'] = fastmap_newline;
3225
3226	/* Return if we have already set `can_be_null'; if we have,
3227	then the fastmap is irrelevant. Something's wrong here. */
3228	else if (bufp->can_be_null)
3229	goto done;
3230
3231	/* Otherwise, have to check alternative paths. */
3232	break;
3233	}
3234
3235	#ifdef emacs
3236	case syntaxspec:
3237	k = *p++;
3238	for (j = 0; j < (1 << BYTEWIDTH); j++)
3239	if (SYNTAX (j) == (enum syntaxcode) k)
3240	fastmap[j] = 1;
3241	break;
3242
3243
3244	case notsyntaxspec:
3245	k = *p++;
3246	for (j = 0; j < (1 << BYTEWIDTH); j++)
3247	if (SYNTAX (j) != (enum syntaxcode) k)
3248	fastmap[j] = 1;
3249	break;
3250
3251
3252	/* All cases after this match the empty string. These end with
3253	`continue'. */
3254
3255
3256	case before_dot:
3257	case at_dot:
3258	case after_dot:
3259	continue;
3260	#endif /* emacs */
3261
3262
3263	case no_op:
3264	case begline:
3265	case endline:
3266	case begbuf:
3267	case endbuf:
3268	case wordbound:
3269	case notwordbound:
3270	case wordbeg:
3271	case wordend:
3272	case push_dummy_failure:
3273	continue;
3274
3275
3276	case jump_n:
3277	case pop_failure_jump:
3278	case maybe_pop_jump:
3279	case jump:
3280	case jump_past_alt:
3281	case dummy_failure_jump:
3282	EXTRACT_NUMBER_AND_INCR (j, p);
3283	p += j;
3284	if (j > 0)
3285	continue;
3286
3287	/* Jump backward implies we just went through the body of a
3288	loop and matched nothing. Opcode jumped to should be
3289	`on_failure_jump' or `succeed_n'. Just treat it like an
3290	ordinary jump. For a * loop, it has pushed its failure
3291	point already; if so, discard that as redundant. */
3292	if ((re_opcode_t) *p != on_failure_jump
3293	&& (re_opcode_t) *p != succeed_n)
3294	continue;
3295
3296	p++;
3297	EXTRACT_NUMBER_AND_INCR (j, p);
3298	p += j;
3299
3300	/* If what's on the stack is where we are now, pop it. */
3301	if (!FAIL_STACK_EMPTY ()
3302	&& fail_stack.stack[fail_stack.avail - 1].pointer == p)
3303	fail_stack.avail--;
3304
3305	continue;
3306
3307
3308	case on_failure_jump:
3309	case on_failure_keep_string_jump:
3310	handle_on_failure_jump:
3311	EXTRACT_NUMBER_AND_INCR (j, p);
3312
3313	/* For some patterns, e.g., `(a?)?', `p+j' here points to the
3314	end of the pattern. We don't want to push such a point,
3315	since when we restore it above, entering the switch will
3316	increment `p' past the end of the pattern. We don't need
3317	to push such a point since we obviously won't find any more
3318	fastmap entries beyond `pend'. Such a pattern can match
3319	the null string, though. */
3320	if (p + j < pend)
3321	{
3322	if (!PUSH_PATTERN_OP (p + j, fail_stack))
3323	{
3324	RESET_FAIL_STACK ();
3325	return -2;
3326	}
3327	}
3328	else
3329	bufp->can_be_null = 1;
3330
3331	if (succeed_n_p)
3332	{
3333	EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
3334	succeed_n_p = false;
3335	}
3336
3337	continue;
3338
3339
3340	case succeed_n:
3341	/* Get to the number of times to succeed. */
3342	p += 2;
3343
3344	/* Increment p past the n for when k != 0. */
3345	EXTRACT_NUMBER_AND_INCR (k, p);
3346	if (k == 0)
3347	{
3348	p -= 4;
3349	succeed_n_p = true; /* Spaghetti code alert. */
3350	goto handle_on_failure_jump;
3351	}
3352	continue;
3353
3354
3355	case set_number_at:
3356	p += 4;
3357	continue;
3358
3359
3360	case start_memory:
3361	case stop_memory:
3362	p += 2;
3363	continue;
3364
3365
3366	default:
3367	abort (); /* We have listed all the cases. */
3368	} /* switch p++ /
3369
3370	/* Getting here means we have found the possible starting
3371	characters for one path of the pattern -- and that the empty
3372	string does not match. We need not follow this path further.
3373	Instead, look at the next alternative (remembered on the
3374	stack), or quit if no more. The test at the top of the loop
3375	does these things. */
3376	path_can_be_null = false;
3377	p = pend;
3378	} /* while p */
3379
3380	/* Set `can_be_null' for the last path (also the first path, if the
3381	pattern is empty). */
3382	bufp->can_be_null \|= path_can_be_null;
3383
3384	done:
3385	RESET_FAIL_STACK ();
3386	return 0;
3387	} /* re_compile_fastmap */
3388
3389	/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
3390	ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
3391	this memory for recording register information. STARTS and ENDS
3392	must be allocated using the malloc library routine, and must each
3393	be at least NUM_REGS * sizeof (regoff_t) bytes long.
3394
3395	If NUM_REGS == 0, then subsequent matches should allocate their own
3396	register data.
3397
3398	Unless this function is called, the first search or match using
3399	PATTERN_BUFFER will allocate its own register data, without
3400	freeing the old data. */
3401
3402	void
3403	re_set_registers (bufp, regs, num_regs, starts, ends)
3404	struct re_pattern_buffer *bufp;
3405	struct re_registers *regs;
3406	unsigned num_regs;
3407	regoff_t starts, ends;
3408	{
3409	if (num_regs)
3410	{
3411	bufp->regs_allocated = REGS_REALLOCATE;
3412	regs->num_regs = num_regs;
3413	regs->start = starts;
3414	regs->end = ends;
3415	}
3416	else
3417	{
3418	bufp->regs_allocated = REGS_UNALLOCATED;
3419	regs->num_regs = 0;
3420	regs->start = regs->end = (regoff_t *) 0;
3421	}
3422	}
3423
3424	/* Searching routines. */
3425
3426	/* Like re_search_2, below, but only one string is specified, and
3427	doesn't let you say where to stop matching. */
3428
3429	int
3430	re_search (bufp, string, size, startpos, range, regs)
3431	struct re_pattern_buffer *bufp;
3432	const char *string;
3433	int size, startpos, range;
3434	struct re_registers *regs;
3435	{
3436	return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3437	regs, size);
3438	}
3439
3440
3441	/* Using the compiled pattern in BUFP->buffer, first tries to match the
3442	virtual concatenation of STRING1 and STRING2, starting first at index
3443	STARTPOS, then at STARTPOS + 1, and so on.
3444
3445	STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3446
3447	RANGE is how far to scan while trying to match. RANGE = 0 means try
3448	only at STARTPOS; in general, the last start tried is STARTPOS +
3449	RANGE.
3450
3451	In REGS, return the indices of the virtual concatenation of STRING1
3452	and STRING2 that matched the entire BUFP->buffer and its contained
3453	subexpressions.
3454
3455	Do not consider matching one past the index STOP in the virtual
3456	concatenation of STRING1 and STRING2.
3457
3458	We return either the position in the strings at which the match was
3459	found, -1 if no match, or -2 if error (such as failure
3460	stack overflow). */
3461
3462	int
3463	re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3464	struct re_pattern_buffer *bufp;
3465	const char string1, string2;
3466	int size1, size2;
3467	int startpos;
3468	int range;
3469	struct re_registers *regs;
3470	int stop;
3471	{
3472	int val;
3473	register char *fastmap = bufp->fastmap;
3474	register RE_TRANSLATE_TYPE translate = bufp->translate;
3475	int total_size = size1 + size2;
3476	int endpos = startpos + range;
3477
3478	/* Check for out-of-range STARTPOS. */
3479	if (startpos < 0 \|\| startpos > total_size)
3480	return -1;
3481
3482	/* Fix up RANGE if it might eventually take us outside
3483	the virtual concatenation of STRING1 and STRING2.
3484	Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE. */
3485	if (endpos < 0)
3486	range = 0 - startpos;
3487	else if (endpos > total_size)
3488	range = total_size - startpos;
3489
3490	/* If the search isn't to be a backwards one, don't waste time in a
3491	search for a pattern that must be anchored. */
3492	if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3493	{
3494	if (startpos > 0)
3495	return -1;
3496	else
3497	range = 1;
3498	}
3499
3500	#ifdef emacs
3501	/* In a forward search for something that starts with \=.
3502	don't keep searching past point. */
3503	if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0)
3504	{
3505	range = PT - startpos;
3506	if (range <= 0)
3507	return -1;
3508	}
3509	#endif /* emacs */
3510
3511	/* Update the fastmap now if not correct already. */
3512	if (fastmap && !bufp->fastmap_accurate)
3513	if (re_compile_fastmap (bufp) == -2)
3514	return -2;
3515
3516	/* Loop through the string, looking for a place to start matching. */
3517	for (;;)
3518	{
3519	/* If a fastmap is supplied, skip quickly over characters that
3520	cannot be the start of a match. If the pattern can match the
3521	null string, however, we don't need to skip characters; we want
3522	the first null string. */
3523	if (fastmap && startpos < total_size && !bufp->can_be_null)
3524	{
3525	if (range > 0) /* Searching forwards. */
3526	{
3527	register const char *d;
3528	register int lim = 0;
3529	int irange = range;
3530
3531	if (startpos < size1 && startpos + range >= size1)
3532	lim = range - (size1 - startpos);
3533
3534	d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3535
3536	/* Written out as an if-else to avoid testing `translate'
3537	inside the loop. */
3538	if (translate)
3539	while (range > lim
3540	&& !fastmap[(unsigned char)
3541	translate[(unsigned char) *d++]])
3542	range--;
3543	else
3544	while (range > lim && !fastmap[(unsigned char) *d++])
3545	range--;
3546
3547	startpos += irange - range;
3548	}
3549	else /* Searching backwards. */
3550	{
3551	register char c = (size1 == 0 \|\| startpos >= size1
3552	? string2[startpos - size1]
3553	: string1[startpos]);
3554
3555	if (!fastmap[(unsigned char) TRANSLATE (c)])
3556	goto advance;
3557	}
3558	}
3559
3560	/* If can't match the null string, and that's all we have left, fail. */
3561	if (range >= 0 && startpos == total_size && fastmap
3562	&& !bufp->can_be_null)
3563	return -1;
3564
3565	val = re_match_2_internal (bufp, string1, size1, string2, size2,
3566	startpos, regs, stop);
3567	#ifndef REGEX_MALLOC
3568	#ifdef C_ALLOCA
3569	alloca (0);
3570	#endif
3571	#endif
3572
3573	if (val >= 0)
3574	return startpos;
3575
3576	if (val == -2)
3577	return -2;
3578
3579	advance:
3580	if (!range)
3581	break;
3582	else if (range > 0)
3583	{
3584	range--;
3585	startpos++;
3586	}
3587	else
3588	{
3589	range++;
3590	startpos--;
3591	}
3592	}
3593	return -1;
3594	} /* re_search_2 */
3595
3596	/* This converts PTR, a pointer into one of the search strings `string1'
3597	and `string2' into an offset from the beginning of that string. */
3598	#define POINTER_TO_OFFSET(ptr) \
3599	(FIRST_STRING_P (ptr) \
3600	? ((regoff_t) ((ptr) - string1)) \
3601	: ((regoff_t) ((ptr) - string2 + size1)))
3602
3603	/* Macros for dealing with the split strings in re_match_2. */
3604
3605	#define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3606
3607	/* Call before fetching a character with *d. This switches over to
3608	string2 if necessary. */
3609	#define PREFETCH() \
3610	while (d == dend) \
3611	{ \
3612	/* End of string2 => fail. */ \
3613	if (dend == end_match_2) \
3614	goto fail; \
3615	/* End of string1 => advance to string2. */ \
3616	d = string2; \
3617	dend = end_match_2; \
3618	}
3619
3620
3621	/* Test if at very beginning or at very end of the virtual concatenation
3622	of `string1' and `string2'. If only one string, it's `string2'. */
3623	#define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) \|\| !size2)
3624	#define AT_STRINGS_END(d) ((d) == end2)
3625
3626
3627	/* Test if D points to a character which is word-constituent. We have
3628	two special cases to check for: if past the end of string1, look at
3629	the first character in string2; and if before the beginning of
3630	string2, look at the last character in string1. */
3631	#define WORDCHAR_P(d) \
3632	(SYNTAX ((d) == end1 ? *string2 \
3633	: (d) == string2 - 1 ? (end1 - 1) : (d)) \
3634	== Sword)
3635
3636	/* Disabled due to a compiler bug -- see comment at case wordbound */
3637	#if 0
3638	/* Test if the character before D and the one at D differ with respect
3639	to being word-constituent. */
3640	#define AT_WORD_BOUNDARY(d) \
3641	(AT_STRINGS_BEG (d) \|\| AT_STRINGS_END (d) \
3642	\|\| WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3643	#endif
3644
3645	/* Free everything we malloc. */
3646	#ifdef MATCH_MAY_ALLOCATE
3647	#define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
3648	#define FREE_VARIABLES() \
3649	do { \
3650	REGEX_FREE_STACK (fail_stack.stack); \
3651	FREE_VAR (regstart); \
3652	FREE_VAR (regend); \
3653	FREE_VAR (old_regstart); \
3654	FREE_VAR (old_regend); \
3655	FREE_VAR (best_regstart); \
3656	FREE_VAR (best_regend); \
3657	FREE_VAR (reg_info); \
3658	FREE_VAR (reg_dummy); \
3659	FREE_VAR (reg_info_dummy); \
3660	} while (0)
3661	#else
3662	#define FREE_VARIABLES() ((void)0) /* Do nothing! But inhibit gcc warning. */
3663	#endif /* not MATCH_MAY_ALLOCATE */
3664
3665	/* These values must meet several constraints. They must not be valid
3666	register values; since we have a limit of 255 registers (because
3667	we use only one byte in the pattern for the register number), we can
3668	use numbers larger than 255. They must differ by 1, because of
3669	NUM_FAILURE_ITEMS above. And the value for the lowest register must
3670	be larger than the value for the highest register, so we do not try
3671	to actually save any registers when none are active. */
3672	#define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3673	#define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3674
3675	/* Matching routines. */
3676
3677	#ifndef emacs /* Emacs never uses this. */
3678	/* re_match is like re_match_2 except it takes only a single string. */
3679
3680	int
3681	re_match (bufp, string, size, pos, regs)
3682	struct re_pattern_buffer *bufp;
3683	const char *string;
3684	int size, pos;
3685	struct re_registers *regs;
3686	{
3687	int result = re_match_2_internal (bufp, NULL, 0, string, size,
3688	pos, regs, size);
3689	#ifndef REGEX_MALLOC
3690	#ifdef C_ALLOCA
3691	alloca (0);
3692	#endif
3693	#endif
3694	return result;
3695	}
3696	#endif /* not emacs */
3697
3698	static boolean group_match_null_string_p _RE_ARGS ((unsigned char **p,
3699	unsigned char *end,
3700	register_info_type *reg_info));
3701	static boolean alt_match_null_string_p _RE_ARGS ((unsigned char *p,
3702	unsigned char *end,
3703	register_info_type *reg_info));
3704	static boolean common_op_match_null_string_p _RE_ARGS ((unsigned char **p,
3705	unsigned char *end,
3706	register_info_type *reg_info));
3707	static int bcmp_translate _RE_ARGS ((const char s1, const char s2,
3708	int len, char *translate));
3709
3710	/* re_match_2 matches the compiled pattern in BUFP against the
3711	the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3712	and SIZE2, respectively). We start matching at POS, and stop
3713	matching at STOP.
3714
3715	If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3716	store offsets for the substring each group matched in REGS. See the
3717	documentation for exactly how many groups we fill.
3718
3719	We return -1 if no match, -2 if an internal error (such as the
3720	failure stack overflowing). Otherwise, we return the length of the
3721	matched substring. */
3722
3723	int
3724	re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3725	struct re_pattern_buffer *bufp;
3726	const char string1, string2;
3727	int size1, size2;
3728	int pos;
3729	struct re_registers *regs;
3730	int stop;
3731	{
3732	int result = re_match_2_internal (bufp, string1, size1, string2, size2,
3733	pos, regs, stop);
3734	#ifndef REGEX_MALLOC
3735	#ifdef C_ALLOCA
3736	alloca (0);
3737	#endif
3738	#endif
3739	return result;
3740	}
3741
3742	/* This is a separate function so that we can force an alloca cleanup
3743	afterwards. */
3744	static int
3745	re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
3746	struct re_pattern_buffer *bufp;
3747	const char string1, string2;
3748	int size1, size2;
3749	int pos;
3750	struct re_registers *regs;
3751	int stop;
3752	{
3753	/* General temporaries. */
3754	int mcnt;
3755	unsigned char *p1;
3756
3757	/* Just past the end of the corresponding string. */
3758	const char end1, end2;
3759
3760	/* Pointers into string1 and string2, just past the last characters in
3761	each to consider matching. */
3762	const char end_match_1, end_match_2;
3763
3764	/* Where we are in the data, and the end of the current string. */
3765	const char d, dend;
3766
3767	/* Where we are in the pattern, and the end of the pattern. */
3768	unsigned char *p = bufp->buffer;
3769	register unsigned char *pend = p + bufp->used;
3770
3771	/* Mark the opcode just after a start_memory, so we can test for an
3772	empty subpattern when we get to the stop_memory. */
3773	unsigned char *just_past_start_mem = 0;
3774
3775	/* We use this to map every character in the string. */
3776	RE_TRANSLATE_TYPE translate = bufp->translate;
3777
3778	/* Failure point stack. Each place that can handle a failure further
3779	down the line pushes a failure point on this stack. It consists of
3780	restart, regend, and reg_info for all registers corresponding to
3781	the subexpressions we're currently inside, plus the number of such
3782	registers, and, finally, two char 's. The first char is where
3783	to resume scanning the pattern; the second one is where to resume
3784	scanning the strings. If the latter is zero, the failure point is
3785	a ``dummy''; if a failure happens and the failure point is a dummy,
3786	it gets discarded and the next next one is tried. */
3787	#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3788	fail_stack_type fail_stack;
3789	#endif
3790	#ifdef DEBUG
3791	static unsigned failure_id = 0;
3792	unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3793	#endif
3794
3795	#ifdef REL_ALLOC
3796	/* This holds the pointer to the failure stack, when
3797	it is allocated relocatably. */
3798	fail_stack_elt_t *failure_stack_ptr;
3799	#endif
3800
3801	/* We fill all the registers internally, independent of what we
3802	return, for use in backreferences. The number here includes
3803	an element for register zero. */
3804	size_t num_regs = bufp->re_nsub + 1;
3805
3806	/* The currently active registers. */
3807	active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3808	active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3809
3810	/* Information on the contents of registers. These are pointers into
3811	the input strings; they record just what was matched (on this
3812	attempt) by a subexpression part of the pattern, that is, the
3813	regnum-th regstart pointer points to where in the pattern we began
3814	matching and the regnum-th regend points to right after where we
3815	stopped matching the regnum-th subexpression. (The zeroth register
3816	keeps track of what the whole pattern matches.) */
3817	#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3818	const char regstart, regend;
3819	#endif
3820
3821	/* If a group that's operated upon by a repetition operator fails to
3822	match anything, then the register for its start will need to be
3823	restored because it will have been set to wherever in the string we
3824	are when we last see its open-group operator. Similarly for a
3825	register's end. */
3826	#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3827	const char old_regstart, old_regend;
3828	#endif
3829
3830	/* The is_active field of reg_info helps us keep track of which (possibly
3831	nested) subexpressions we are currently in. The matched_something
3832	field of reg_info[reg_num] helps us tell whether or not we have
3833	matched any of the pattern so far this time through the reg_num-th
3834	subexpression. These two fields get reset each time through any
3835	loop their register is in. */
3836	#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3837	register_info_type *reg_info;
3838	#endif
3839
3840	/* The following record the register info as found in the above
3841	variables when we find a match better than any we've seen before.
3842	This happens as we backtrack through the failure points, which in
3843	turn happens only if we have not yet matched the entire string. */
3844	unsigned best_regs_set = false;
3845	#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3846	const char best_regstart, best_regend;
3847	#endif
3848
3849	/* Logically, this is `best_regend[0]'. But we don't want to have to
3850	allocate space for that if we're not allocating space for anything
3851	else (see below). Also, we never need info about register 0 for
3852	any of the other register vectors, and it seems rather a kludge to
3853	treat `best_regend' differently than the rest. So we keep track of
3854	the end of the best match so far in a separate variable. We
3855	initialize this to NULL so that when we backtrack the first time
3856	and need to test it, it's not garbage. */
3857	const char *match_end = NULL;
3858
3859	/* This helps SET_REGS_MATCHED avoid doing redundant work. */
3860	int set_regs_matched_done = 0;
3861
3862	/* Used when we pop values we don't care about. */
3863	#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3864	const char **reg_dummy;
3865	register_info_type *reg_info_dummy;
3866	#endif
3867
3868	#ifdef DEBUG
3869	/* Counts the total number of registers pushed. */
3870	unsigned num_regs_pushed = 0;
3871	#endif
3872
3873	DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3874
3875	INIT_FAIL_STACK ();
3876
3877	#ifdef MATCH_MAY_ALLOCATE
3878	/* Do not bother to initialize all the register variables if there are
3879	no groups in the pattern, as it takes a fair amount of time. If
3880	there are groups, we include space for register 0 (the whole
3881	pattern), even though we never use it, since it simplifies the
3882	array indexing. We should fix this. */
3883	if (bufp->re_nsub)
3884	{
3885	regstart = REGEX_TALLOC (num_regs, const char *);
3886	regend = REGEX_TALLOC (num_regs, const char *);
3887	old_regstart = REGEX_TALLOC (num_regs, const char *);
3888	old_regend = REGEX_TALLOC (num_regs, const char *);
3889	best_regstart = REGEX_TALLOC (num_regs, const char *);
3890	best_regend = REGEX_TALLOC (num_regs, const char *);
3891	reg_info = REGEX_TALLOC (num_regs, register_info_type);
3892	reg_dummy = REGEX_TALLOC (num_regs, const char *);
3893	reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3894
3895	if (!(regstart && regend && old_regstart && old_regend && reg_info
3896	&& best_regstart && best_regend && reg_dummy && reg_info_dummy))
3897	{
3898	FREE_VARIABLES ();
3899	return -2;
3900	}
3901	}
3902	else
3903	{
3904	/* We must initialize all our variables to NULL, so that
3905	`FREE_VARIABLES' doesn't try to free them. */
3906	regstart = regend = old_regstart = old_regend = best_regstart
3907	= best_regend = reg_dummy = NULL;
3908	reg_info = reg_info_dummy = (register_info_type *) NULL;
3909	}
3910	#endif /* MATCH_MAY_ALLOCATE */
3911
3912	/* The starting position is bogus. */
3913	if (pos < 0 \|\| pos > size1 + size2)
3914	{
3915	FREE_VARIABLES ();
3916	return -1;
3917	}
3918
3919	/* Initialize subexpression text positions to -1 to mark ones that no
3920	start_memory/stop_memory has been seen for. Also initialize the
3921	register information struct. */
3922	for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
3923	{
3924	regstart[mcnt] = regend[mcnt]
3925	= old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3926
3927	REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3928	IS_ACTIVE (reg_info[mcnt]) = 0;
3929	MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3930	EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3931	}
3932
3933	/* We move `string1' into `string2' if the latter's empty -- but not if
3934	`string1' is null. */
3935	if (size2 == 0 && string1 != NULL)
3936	{
3937	string2 = string1;
3938	size2 = size1;
3939	string1 = 0;
3940	size1 = 0;
3941	}
3942	end1 = string1 + size1;
3943	end2 = string2 + size2;
3944
3945	/* Compute where to stop matching, within the two strings. */
3946	if (stop <= size1)
3947	{
3948	end_match_1 = string1 + stop;
3949	end_match_2 = string2;
3950	}
3951	else
3952	{
3953	end_match_1 = end1;
3954	end_match_2 = string2 + stop - size1;
3955	}
3956
3957	/* `p' scans through the pattern as `d' scans through the data.
3958	`dend' is the end of the input string that `d' points within. `d'
3959	is advanced into the following input string whenever necessary, but
3960	this happens before fetching; therefore, at the beginning of the
3961	loop, `d' can be pointing at the end of a string, but it cannot
3962	equal `string2'. */
3963	if (size1 > 0 && pos <= size1)
3964	{
3965	d = string1 + pos;
3966	dend = end_match_1;
3967	}
3968	else
3969	{
3970	d = string2 + pos - size1;
3971	dend = end_match_2;
3972	}
3973
3974	DEBUG_PRINT1 ("The compiled pattern is:\n");
3975	DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3976	DEBUG_PRINT1 ("The string to match is: `");
3977	DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3978	DEBUG_PRINT1 ("'\n");
3979
3980	/* This loops over pattern commands. It exits by returning from the
3981	function if the match is complete, or it drops through if the match
3982	fails at this starting point in the input data. */
3983	for (;;)
3984	{
3985	#ifdef _LIBC
3986	DEBUG_PRINT2 ("\n%p: ", p);
3987	#else
3988	DEBUG_PRINT2 ("\n0x%x: ", p);
3989	#endif
3990
3991	if (p == pend)
3992	{ /* End of pattern means we might have succeeded. */
3993	DEBUG_PRINT1 ("end of pattern ... ");
3994
3995	/* If we haven't matched the entire string, and we want the
3996	longest match, try backtracking. */
3997	if (d != end_match_2)
3998	{
3999	/* 1 if this match ends in the same string (string1 or string2)
4000	as the best previous match. */
4001	boolean same_str_p = (FIRST_STRING_P (match_end)
4002	== MATCHING_IN_FIRST_STRING);
4003	/* 1 if this match is the best seen so far. */
4004	boolean best_match_p;
4005
4006	/* AIX compiler got confused when this was combined
4007	with the previous declaration. */
4008	if (same_str_p)
4009	best_match_p = d > match_end;
4010	else
4011	best_match_p = !MATCHING_IN_FIRST_STRING;
4012
4013	DEBUG_PRINT1 ("backtracking.\n");
4014
4015	if (!FAIL_STACK_EMPTY ())
4016	{ /* More failure points to try. */
4017
4018	/* If exceeds best match so far, save it. */
4019	if (!best_regs_set \|\| best_match_p)
4020	{
4021	best_regs_set = true;
4022	match_end = d;
4023
4024	DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
4025
4026	for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
4027	{
4028	best_regstart[mcnt] = regstart[mcnt];
4029	best_regend[mcnt] = regend[mcnt];
4030	}
4031	}
4032	goto fail;
4033	}
4034
4035	/* If no failure points, don't restore garbage. And if
4036	last match is real best match, don't restore second
4037	best one. */
4038	else if (best_regs_set && !best_match_p)
4039	{
4040	restore_best_regs:
4041	/* Restore best match. It may happen that `dend ==
4042	end_match_1' while the restored d is in string2.
4043	For example, the pattern `x.y.z' against the
4044	strings `x-' and `y-z-', if the two strings are
4045	not consecutive in memory. */
4046	DEBUG_PRINT1 ("Restoring best registers.\n");
4047
4048	d = match_end;
4049	dend = ((d >= string1 && d <= end1)
4050	? end_match_1 : end_match_2);
4051
4052	for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
4053	{
4054	regstart[mcnt] = best_regstart[mcnt];
4055	regend[mcnt] = best_regend[mcnt];
4056	}
4057	}
4058	} /* d != end_match_2 */
4059
4060	succeed_label:
4061	DEBUG_PRINT1 ("Accepting match.\n");
4062
4063	/* If caller wants register contents data back, do it. */
4064	if (regs && !bufp->no_sub)
4065	{
4066	/* Have the register data arrays been allocated? */
4067	if (bufp->regs_allocated == REGS_UNALLOCATED)
4068	{ /* No. So allocate them with malloc. We need one
4069	extra element beyond `num_regs' for the `-1' marker
4070	GNU code uses. */
4071	regs->num_regs = MAX (RE_NREGS, num_regs + 1);
4072	regs->start = TALLOC (regs->num_regs, regoff_t);
4073	regs->end = TALLOC (regs->num_regs, regoff_t);
4074	if (regs->start == NULL \|\| regs->end == NULL)
4075	{
4076	FREE_VARIABLES ();
4077	return -2;
4078	}
4079	bufp->regs_allocated = REGS_REALLOCATE;
4080	}
4081	else if (bufp->regs_allocated == REGS_REALLOCATE)
4082	{ /* Yes. If we need more elements than were already
4083	allocated, reallocate them. If we need fewer, just
4084	leave it alone. */
4085	if (regs->num_regs < num_regs + 1)
4086	{
4087	regs->num_regs = num_regs + 1;
4088	RETALLOC (regs->start, regs->num_regs, regoff_t);
4089	RETALLOC (regs->end, regs->num_regs, regoff_t);
4090	if (regs->start == NULL \|\| regs->end == NULL)
4091	{
4092	FREE_VARIABLES ();
4093	return -2;
4094	}
4095	}
4096	}
4097	else
4098	{
4099	/* These braces fend off a "empty body in an else-statement"
4100	warning under GCC when assert expands to nothing. */
4101	assert (bufp->regs_allocated == REGS_FIXED);
4102	}
4103
4104	/* Convert the pointer data in `regstart' and `regend' to
4105	indices. Register zero has to be set differently,
4106	since we haven't kept track of any info for it. */
4107	if (regs->num_regs > 0)
4108	{
4109	regs->start[0] = pos;
4110	regs->end[0] = (MATCHING_IN_FIRST_STRING
4111	? ((regoff_t) (d - string1))
4112	: ((regoff_t) (d - string2 + size1)));
4113	}
4114
4115	/* Go through the first `min (num_regs, regs->num_regs)'
4116	registers, since that is all we initialized. */
4117	for (mcnt = 1; (unsigned) mcnt < MIN (num_regs, regs->num_regs);
4118	mcnt++)
4119	{
4120	if (REG_UNSET (regstart[mcnt]) \|\| REG_UNSET (regend[mcnt]))
4121	regs->start[mcnt] = regs->end[mcnt] = -1;
4122	else
4123	{
4124	regs->start[mcnt]
4125	= (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
4126	regs->end[mcnt]
4127	= (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
4128	}
4129	}
4130
4131	/* If the regs structure we return has more elements than
4132	were in the pattern, set the extra elements to -1. If
4133	we (re)allocated the registers, this is the case,
4134	because we always allocate enough to have at least one
4135	-1 at the end. */
4136	for (mcnt = num_regs; (unsigned) mcnt < regs->num_regs; mcnt++)
4137	regs->start[mcnt] = regs->end[mcnt] = -1;
4138	} /* regs && !bufp->no_sub */
4139
4140	DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
4141	nfailure_points_pushed, nfailure_points_popped,
4142	nfailure_points_pushed - nfailure_points_popped);
4143	DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
4144
4145	mcnt = d - pos - (MATCHING_IN_FIRST_STRING
4146	? string1
4147	: string2 - size1);
4148
4149	DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
4150
4151	FREE_VARIABLES ();
4152	return mcnt;
4153	}
4154
4155	/* Otherwise match next pattern command. */
4156	switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
4157	{
4158	/* Ignore these. Used to ignore the n of succeed_n's which
4159	currently have n == 0. */
4160	case no_op:
4161	DEBUG_PRINT1 ("EXECUTING no_op.\n");
4162	break;
4163
4164	case succeed:
4165	DEBUG_PRINT1 ("EXECUTING succeed.\n");
4166	goto succeed_label;
4167
4168	/* Match the next n pattern characters exactly. The following
4169	byte in the pattern defines n, and the n bytes after that
4170	are the characters to match. */
4171	case exactn:
4172	mcnt = *p++;
4173	DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
4174
4175	/* This is written out as an if-else so we don't waste time
4176	testing `translate' inside the loop. */
4177	if (translate)
4178	{
4179	do
4180	{
4181	PREFETCH ();
4182	if ((unsigned char) translate[(unsigned char) *d++]
4183	!= (unsigned char) *p++)
4184	goto fail;
4185	}
4186	while (--mcnt);
4187	}
4188	else
4189	{
4190	do
4191	{
4192	PREFETCH ();
4193	if (d++ != (char) p++) goto fail;
4194	}
4195	while (--mcnt);
4196	}
4197	SET_REGS_MATCHED ();
4198	break;
4199
4200
4201	/* Match any character except possibly a newline or a null. */
4202	case anychar:
4203	DEBUG_PRINT1 ("EXECUTING anychar.\n");
4204
4205	PREFETCH ();
4206
4207	if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
4208	\|\| (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
4209	goto fail;
4210
4211	SET_REGS_MATCHED ();
4212	DEBUG_PRINT2 (" Matched `%d'.\n", *d);
4213	d++;
4214	break;
4215
4216
4217	case charset:
4218	case charset_not:
4219	{
4220	register unsigned char c;
4221	boolean not = (re_opcode_t) *(p - 1) == charset_not;
4222
4223	DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
4224
4225	PREFETCH ();
4226	c = TRANSLATE (d); / The character to match. */
4227
4228	/* Cast to `unsigned' instead of `unsigned char' in case the
4229	bit list is a full 32 bytes long. */
4230	if (c < (unsigned) (p BYTEWIDTH)
4231	&& p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4232	not = !not;
4233
4234	p += 1 + *p;
4235
4236	if (!not) goto fail;
4237
4238	SET_REGS_MATCHED ();
4239	d++;
4240	break;
4241	}
4242
4243
4244	/* The beginning of a group is represented by start_memory.
4245	The arguments are the register number in the next byte, and the
4246	number of groups inner to this one in the next. The text
4247	matched within the group is recorded (in the internal
4248	registers data structure) under the register number. */
4249	case start_memory:
4250	DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
4251
4252	/* Find out if this group can match the empty string. */
4253	p1 = p; /* To send to group_match_null_string_p. */
4254
4255	if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
4256	REG_MATCH_NULL_STRING_P (reg_info[*p])
4257	= group_match_null_string_p (&p1, pend, reg_info);
4258
4259	/* Save the position in the string where we were the last time
4260	we were at this open-group operator in case the group is
4261	operated upon by a repetition operator, e.g., with `(a)b'
4262	against `ab'; then we want to ignore where we are now in
4263	the string in case this attempt to match fails. */
4264	old_regstart[p] = REG_MATCH_NULL_STRING_P (reg_info[p])
4265	? REG_UNSET (regstart[p]) ? d : regstart[p]
4266	: regstart[*p];
4267	DEBUG_PRINT2 (" old_regstart: %d\n",
4268	POINTER_TO_OFFSET (old_regstart[*p]));
4269
4270	regstart[*p] = d;
4271	DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
4272
4273	IS_ACTIVE (reg_info[*p]) = 1;
4274	MATCHED_SOMETHING (reg_info[*p]) = 0;
4275
4276	/* Clear this whenever we change the register activity status. */
4277	set_regs_matched_done = 0;
4278
4279	/* This is the new highest active register. */
4280	highest_active_reg = *p;
4281
4282	/* If nothing was active before, this is the new lowest active
4283	register. */
4284	if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4285	lowest_active_reg = *p;
4286
4287	/* Move past the register number and inner group count. */
4288	p += 2;
4289	just_past_start_mem = p;
4290
4291	break;
4292
4293
4294	/* The stop_memory opcode represents the end of a group. Its
4295	arguments are the same as start_memory's: the register
4296	number, and the number of inner groups. */
4297	case stop_memory:
4298	DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
4299
4300	/* We need to save the string position the last time we were at
4301	this close-group operator in case the group is operated
4302	upon by a repetition operator, e.g., with `((a)(b))*'
4303	against `aba'; then we want to ignore where we are now in
4304	the string in case this attempt to match fails. */
4305	old_regend[p] = REG_MATCH_NULL_STRING_P (reg_info[p])
4306	? REG_UNSET (regend[p]) ? d : regend[p]
4307	: regend[*p];
4308	DEBUG_PRINT2 (" old_regend: %d\n",
4309	POINTER_TO_OFFSET (old_regend[*p]));
4310
4311	regend[*p] = d;
4312	DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
4313
4314	/* This register isn't active anymore. */
4315	IS_ACTIVE (reg_info[*p]) = 0;
4316
4317	/* Clear this whenever we change the register activity status. */
4318	set_regs_matched_done = 0;
4319
4320	/* If this was the only register active, nothing is active
4321	anymore. */
4322	if (lowest_active_reg == highest_active_reg)
4323	{
4324	lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4325	highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4326	}
4327	else
4328	{ /* We must scan for the new highest active register, since
4329	it isn't necessarily one less than now: consider
4330	(a(b)c(d(e)f)g). When group 3 ends, after the f), the
4331	new highest active register is 1. */
4332	unsigned char r = *p - 1;
4333	while (r > 0 && !IS_ACTIVE (reg_info[r]))
4334	r--;
4335
4336	/* If we end up at register zero, that means that we saved
4337	the registers as the result of an `on_failure_jump', not
4338	a `start_memory', and we jumped to past the innermost
4339	`stop_memory'. For example, in ((.)*) we save
4340	registers 1 and 2 as a result of the *, but when we pop
4341	back to the second ), we are at the stop_memory 1.
4342	Thus, nothing is active. */
4343	if (r == 0)
4344	{
4345	lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4346	highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4347	}
4348	else
4349	highest_active_reg = r;
4350	}
4351
4352	/* If just failed to match something this time around with a
4353	group that's operated on by a repetition operator, try to
4354	force exit from the ``loop'', and restore the register
4355	information for this group that we had before trying this
4356	last match. */
4357	if ((!MATCHED_SOMETHING (reg_info[*p])
4358	\|\| just_past_start_mem == p - 1)
4359	&& (p + 2) < pend)
4360	{
4361	boolean is_a_jump_n = false;
4362
4363	p1 = p + 2;
4364	mcnt = 0;
4365	switch ((re_opcode_t) *p1++)
4366	{
4367	case jump_n:
4368	is_a_jump_n = true;
4369	case pop_failure_jump:
4370	case maybe_pop_jump:
4371	case jump:
4372	case dummy_failure_jump:
4373	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4374	if (is_a_jump_n)
4375	p1 += 2;
4376	break;
4377
4378	default:
4379	/* do nothing */ ;
4380	}
4381	p1 += mcnt;
4382
4383	/* If the next operation is a jump backwards in the pattern
4384	to an on_failure_jump right before the start_memory
4385	corresponding to this stop_memory, exit from the loop
4386	by forcing a failure after pushing on the stack the
4387	on_failure_jump's jump in the pattern, and d. */
4388	if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
4389	&& (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
4390	{
4391	/* If this group ever matched anything, then restore
4392	what its registers were before trying this last
4393	failed match, e.g., with `(a)b' against `ab' for
4394	regstart[1], and, e.g., with `((a)(b))*'
4395	against `aba' for regend[3].
4396
4397	Also restore the registers for inner groups for,
4398	e.g., `((a)(b))*' against `aba' (register 3 would
4399	otherwise get trashed). */
4400
4401	if (EVER_MATCHED_SOMETHING (reg_info[*p]))
4402	{
4403	unsigned r;
4404
4405	EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
4406
4407	/* Restore this and inner groups' (if any) registers. */
4408	for (r = p; r < (unsigned) p + (unsigned) *(p + 1);
4409	r++)
4410	{
4411	regstart[r] = old_regstart[r];
4412
4413	/* xx why this test? */
4414	if (old_regend[r] >= regstart[r])
4415	regend[r] = old_regend[r];
4416	}
4417	}
4418	p1++;
4419	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4420	PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
4421
4422	goto fail;
4423	}
4424	}
4425
4426	/* Move past the register number and the inner group count. */
4427	p += 2;
4428	break;
4429
4430
4431	/* \<digit> has been turned into a `duplicate' command which is
4432	followed by the numeric value of <digit> as the register number. */
4433	case duplicate:
4434	{
4435	register const char d2, dend2;
4436	int regno = p++; / Get which register to match against. */
4437	DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
4438
4439	/* Can't back reference a group which we've never matched. */
4440	if (REG_UNSET (regstart[regno]) \|\| REG_UNSET (regend[regno]))
4441	goto fail;
4442
4443	/* Where in input to try to start matching. */
4444	d2 = regstart[regno];
4445
4446	/* Where to stop matching; if both the place to start and
4447	the place to stop matching are in the same string, then
4448	set to the place to stop, otherwise, for now have to use
4449	the end of the first string. */
4450
4451	dend2 = ((FIRST_STRING_P (regstart[regno])
4452	== FIRST_STRING_P (regend[regno]))
4453	? regend[regno] : end_match_1);
4454	for (;;)
4455	{
4456	/* If necessary, advance to next segment in register
4457	contents. */
4458	while (d2 == dend2)
4459	{
4460	if (dend2 == end_match_2) break;
4461	if (dend2 == regend[regno]) break;
4462
4463	/* End of string1 => advance to string2. */
4464	d2 = string2;
4465	dend2 = regend[regno];
4466	}
4467	/* At end of register contents => success */
4468	if (d2 == dend2) break;
4469
4470	/* If necessary, advance to next segment in data. */
4471	PREFETCH ();
4472
4473	/* How many characters left in this segment to match. */
4474	mcnt = dend - d;
4475
4476	/* Want how many consecutive characters we can match in
4477	one shot, so, if necessary, adjust the count. */
4478	if (mcnt > dend2 - d2)
4479	mcnt = dend2 - d2;
4480
4481	/* Compare that many; failure if mismatch, else move
4482	past them. */
4483	if (translate
4484	? bcmp_translate (d, d2, mcnt, translate)
4485	: bcmp (d, d2, mcnt))
4486	goto fail;
4487	d += mcnt, d2 += mcnt;
4488
4489	/* Do this because we've match some characters. */
4490	SET_REGS_MATCHED ();
4491	}
4492	}
4493	break;
4494
4495
4496	/* begline matches the empty string at the beginning of the string
4497	(unless `not_bol' is set in `bufp'), and, if
4498	`newline_anchor' is set, after newlines. */
4499	case begline:
4500	DEBUG_PRINT1 ("EXECUTING begline.\n");
4501
4502	if (AT_STRINGS_BEG (d))
4503	{
4504	if (!bufp->not_bol) break;
4505	}
4506	else if (d[-1] == '\n' && bufp->newline_anchor)
4507	{
4508	break;
4509	}
4510	/* In all other cases, we fail. */
4511	goto fail;
4512
4513
4514	/* endline is the dual of begline. */
4515	case endline:
4516	DEBUG_PRINT1 ("EXECUTING endline.\n");
4517
4518	if (AT_STRINGS_END (d))
4519	{
4520	if (!bufp->not_eol) break;
4521	}
4522
4523	/* We have to ``prefetch'' the next character. */
4524	else if ((d == end1 ? string2 : d) == '\n'
4525	&& bufp->newline_anchor)
4526	{
4527	break;
4528	}
4529	goto fail;
4530
4531
4532	/* Match at the very beginning of the data. */
4533	case begbuf:
4534	DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4535	if (AT_STRINGS_BEG (d))
4536	break;
4537	goto fail;
4538
4539
4540	/* Match at the very end of the data. */
4541	case endbuf:
4542	DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4543	if (AT_STRINGS_END (d))
4544	break;
4545	goto fail;
4546
4547
4548	/* on_failure_keep_string_jump is used to optimize `.*\n'. It
4549	pushes NULL as the value for the string on the stack. Then
4550	`pop_failure_point' will keep the current value for the
4551	string, instead of restoring it. To see why, consider
4552	matching `foo\nbar' against `.\n'. The . matches the foo;
4553	then the . fails against the \n. But the next thing we want
4554	to do is match the \n against the \n; if we restored the
4555	string value, we would be back at the foo.
4556
4557	Because this is used only in specific cases, we don't need to
4558	check all the things that `on_failure_jump' does, to make
4559	sure the right things get saved on the stack. Hence we don't
4560	share its code. The only reason to push anything on the
4561	stack at all is that otherwise we would have to change
4562	`anychar's code to do something besides goto fail in this
4563	case; that seems worse than this. */
4564	case on_failure_keep_string_jump:
4565	DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4566
4567	EXTRACT_NUMBER_AND_INCR (mcnt, p);
4568	#ifdef _LIBC
4569	DEBUG_PRINT3 (" %d (to %p):\n", mcnt, p + mcnt);
4570	#else
4571	DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4572	#endif
4573
4574	PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4575	break;
4576
4577
4578	/* Uses of on_failure_jump:
4579
4580	Each alternative starts with an on_failure_jump that points
4581	to the beginning of the next alternative. Each alternative
4582	except the last ends with a jump that in effect jumps past
4583	the rest of the alternatives. (They really jump to the
4584	ending jump of the following alternative, because tensioning
4585	these jumps is a hassle.)
4586
4587	Repeats start with an on_failure_jump that points past both
4588	the repetition text and either the following jump or
4589	pop_failure_jump back to this on_failure_jump. */
4590	case on_failure_jump:
4591	on_failure:
4592	DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4593
4594	EXTRACT_NUMBER_AND_INCR (mcnt, p);
4595	#ifdef _LIBC
4596	DEBUG_PRINT3 (" %d (to %p)", mcnt, p + mcnt);
4597	#else
4598	DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4599	#endif
4600
4601	/* If this on_failure_jump comes right before a group (i.e.,
4602	the original * applied to a group), save the information
4603	for that group and all inner ones, so that if we fail back
4604	to this point, the group's information will be correct.
4605	For example, in $a$\1, we need the preceding group,
4606	and in $zz\(a$b\)\2, we need the inner group. */
4607
4608	/* We can't use `p' to check ahead because we push
4609	a failure point to `p + mcnt' after we do this. */
4610	p1 = p;
4611
4612	/* We need to skip no_op's before we look for the
4613	start_memory in case this on_failure_jump is happening as
4614	the result of a completed succeed_n, as in $a$\{1,3\}b\1
4615	against aba. */
4616	while (p1 < pend && (re_opcode_t) *p1 == no_op)
4617	p1++;
4618
4619	if (p1 < pend && (re_opcode_t) *p1 == start_memory)
4620	{
4621	/* We have a new highest active register now. This will
4622	get reset at the start_memory we are about to get to,
4623	but we will have saved all the registers relevant to
4624	this repetition op, as described above. */
4625	highest_active_reg = (p1 + 1) + (p1 + 2);
4626	if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4627	lowest_active_reg = *(p1 + 1);
4628	}
4629
4630	DEBUG_PRINT1 (":\n");
4631	PUSH_FAILURE_POINT (p + mcnt, d, -2);
4632	break;
4633
4634
4635	/* A smart repeat ends with `maybe_pop_jump'.
4636	We change it to either `pop_failure_jump' or `jump'. */
4637	case maybe_pop_jump:
4638	EXTRACT_NUMBER_AND_INCR (mcnt, p);
4639	DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4640	{
4641	register unsigned char *p2 = p;
4642
4643	/* Compare the beginning of the repeat with what in the
4644	pattern follows its end. If we can establish that there
4645	is nothing that they would both match, i.e., that we
4646	would have to backtrack because of (as in, e.g., `a*a')
4647	then we can change to pop_failure_jump, because we'll
4648	never have to backtrack.
4649
4650	This is not true in the case of alternatives: in
4651	`(a\|ab)*' we do need to backtrack to the `ab' alternative
4652	(e.g., if the string was `ab'). But instead of trying to
4653	detect that here, the alternative has put on a dummy
4654	failure point which is what we will end up popping. */
4655
4656	/* Skip over open/close-group commands.
4657	If what follows this loop is a ...+ construct,
4658	look at what begins its body, since we will have to
4659	match at least one of that. */
4660	while (1)
4661	{
4662	if (p2 + 2 < pend
4663	&& ((re_opcode_t) *p2 == stop_memory
4664	\|\| (re_opcode_t) *p2 == start_memory))
4665	p2 += 3;
4666	else if (p2 + 6 < pend
4667	&& (re_opcode_t) *p2 == dummy_failure_jump)
4668	p2 += 6;
4669	else
4670	break;
4671	}
4672
4673	p1 = p + mcnt;
4674	/* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4675	to the `maybe_finalize_jump' of this case. Examine what
4676	follows. */
4677
4678	/* If we're at the end of the pattern, we can change. */
4679	if (p2 == pend)
4680	{
4681	/* Consider what happens when matching ":$.*$"
4682	against ":/". I don't really understand this code
4683	yet. */
4684	p[-3] = (unsigned char) pop_failure_jump;
4685	DEBUG_PRINT1
4686	(" End of pattern: change to `pop_failure_jump'.\n");
4687	}
4688
4689	else if ((re_opcode_t) *p2 == exactn
4690	\|\| (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4691	{
4692	register unsigned char c
4693	= *p2 == (unsigned char) endline ? '\n' : p2[2];
4694
4695	if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4696	{
4697	p[-3] = (unsigned char) pop_failure_jump;
4698	DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4699	c, p1[5]);
4700	}
4701
4702	else if ((re_opcode_t) p1[3] == charset
4703	\|\| (re_opcode_t) p1[3] == charset_not)
4704	{
4705	int not = (re_opcode_t) p1[3] == charset_not;
4706
4707	if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4708	&& p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4709	not = !not;
4710
4711	/* `not' is equal to 1 if c would match, which means
4712	that we can't change to pop_failure_jump. */
4713	if (!not)
4714	{
4715	p[-3] = (unsigned char) pop_failure_jump;
4716	DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4717	}
4718	}
4719	}
4720	else if ((re_opcode_t) *p2 == charset)
4721	{
4722	#ifdef DEBUG
4723	register unsigned char c
4724	= *p2 == (unsigned char) endline ? '\n' : p2[2];
4725	#endif
4726
4727	#if 0
4728	if ((re_opcode_t) p1[3] == exactn
4729	&& ! ((int) p2[1] * BYTEWIDTH > (int) p1[5]
4730	&& (p2[2 + p1[5] / BYTEWIDTH]
4731	& (1 << (p1[5] % BYTEWIDTH)))))
4732	#else
4733	if ((re_opcode_t) p1[3] == exactn
4734	&& ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
4735	&& (p2[2 + p1[4] / BYTEWIDTH]
4736	& (1 << (p1[4] % BYTEWIDTH)))))
4737	#endif
4738	{
4739	p[-3] = (unsigned char) pop_failure_jump;
4740	DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4741	c, p1[5]);
4742	}
4743
4744	else if ((re_opcode_t) p1[3] == charset_not)
4745	{
4746	int idx;
4747	/* We win if the charset_not inside the loop
4748	lists every character listed in the charset after. */
4749	for (idx = 0; idx < (int) p2[1]; idx++)
4750	if (! (p2[2 + idx] == 0
4751	\|\| (idx < (int) p1[4]
4752	&& ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
4753	break;
4754
4755	if (idx == p2[1])
4756	{
4757	p[-3] = (unsigned char) pop_failure_jump;
4758	DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4759	}
4760	}
4761	else if ((re_opcode_t) p1[3] == charset)
4762	{
4763	int idx;
4764	/* We win if the charset inside the loop
4765	has no overlap with the one after the loop. */
4766	for (idx = 0;
4767	idx < (int) p2[1] && idx < (int) p1[4];
4768	idx++)
4769	if ((p2[2 + idx] & p1[5 + idx]) != 0)
4770	break;
4771
4772	if (idx == p2[1] \|\| idx == p1[4])
4773	{
4774	p[-3] = (unsigned char) pop_failure_jump;
4775	DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4776	}
4777	}
4778	}
4779	}
4780	p -= 2; /* Point at relative address again. */
4781	if ((re_opcode_t) p[-1] != pop_failure_jump)
4782	{
4783	p[-1] = (unsigned char) jump;
4784	DEBUG_PRINT1 (" Match => jump.\n");
4785	goto unconditional_jump;
4786	}
4787	/* Note fall through. */
4788
4789
4790	/* The end of a simple repeat has a pop_failure_jump back to
4791	its matching on_failure_jump, where the latter will push a
4792	failure point. The pop_failure_jump takes off failure
4793	points put on by this pop_failure_jump's matching
4794	on_failure_jump; we got through the pattern to here from the
4795	matching on_failure_jump, so didn't fail. */
4796	case pop_failure_jump:
4797	{
4798	/* We need to pass separate storage for the lowest and
4799	highest registers, even though we don't care about the
4800	actual values. Otherwise, we will restore only one
4801	register from the stack, since lowest will == highest in
4802	`pop_failure_point'. */
4803	active_reg_t dummy_low_reg, dummy_high_reg;
4804	unsigned char *pdummy;
4805	const char *sdummy;
4806
4807	DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4808	POP_FAILURE_POINT (sdummy, pdummy,
4809	dummy_low_reg, dummy_high_reg,
4810	reg_dummy, reg_dummy, reg_info_dummy);
4811	}
4812	/* Note fall through. */
4813
4814	unconditional_jump:
4815	#ifdef _LIBC
4816	DEBUG_PRINT2 ("\n%p: ", p);
4817	#else
4818	DEBUG_PRINT2 ("\n0x%x: ", p);
4819	#endif
4820	/* Note fall through. */
4821
4822	/* Unconditionally jump (without popping any failure points). */
4823	case jump:
4824	EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4825	DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4826	p += mcnt; /* Do the jump. */
4827	#ifdef _LIBC
4828	DEBUG_PRINT2 ("(to %p).\n", p);
4829	#else
4830	DEBUG_PRINT2 ("(to 0x%x).\n", p);
4831	#endif
4832	break;
4833
4834
4835	/* We need this opcode so we can detect where alternatives end
4836	in `group_match_null_string_p' et al. */
4837	case jump_past_alt:
4838	DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4839	goto unconditional_jump;
4840
4841
4842	/* Normally, the on_failure_jump pushes a failure point, which
4843	then gets popped at pop_failure_jump. We will end up at
4844	pop_failure_jump, also, and with a pattern of, say, `a+', we
4845	are skipping over the on_failure_jump, so we have to push
4846	something meaningless for pop_failure_jump to pop. */
4847	case dummy_failure_jump:
4848	DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4849	/* It doesn't matter what we push for the string here. What
4850	the code at `fail' tests is the value for the pattern. */
4851	PUSH_FAILURE_POINT (0, 0, -2);
4852	goto unconditional_jump;
4853
4854
4855	/* At the end of an alternative, we need to push a dummy failure
4856	point in case we are followed by a `pop_failure_jump', because
4857	we don't want the failure point for the alternative to be
4858	popped. For example, matching `(a\|ab)*' against `aab'
4859	requires that we match the `ab' alternative. */
4860	case push_dummy_failure:
4861	DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4862	/* See comments just above at `dummy_failure_jump' about the
4863	two zeroes. */
4864	PUSH_FAILURE_POINT (0, 0, -2);
4865	break;
4866
4867	/* Have to succeed matching what follows at least n times.
4868	After that, handle like `on_failure_jump'. */
4869	case succeed_n:
4870	EXTRACT_NUMBER (mcnt, p + 2);
4871	DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4872
4873	assert (mcnt >= 0);
4874	/* Originally, this is how many times we HAVE to succeed. */
4875	if (mcnt > 0)
4876	{
4877	mcnt--;
4878	p += 2;
4879	STORE_NUMBER_AND_INCR (p, mcnt);
4880	#ifdef _LIBC
4881	DEBUG_PRINT3 (" Setting %p to %d.\n", p - 2, mcnt);
4882	#else
4883	DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p - 2, mcnt);
4884	#endif
4885	}
4886	else if (mcnt == 0)
4887	{
4888	#ifdef _LIBC
4889	DEBUG_PRINT2 (" Setting two bytes from %p to no_op.\n", p+2);
4890	#else
4891	DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4892	#endif
4893	p[2] = (unsigned char) no_op;
4894	p[3] = (unsigned char) no_op;
4895	goto on_failure;
4896	}
4897	break;
4898
4899	case jump_n:
4900	EXTRACT_NUMBER (mcnt, p + 2);
4901	DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4902
4903	/* Originally, this is how many times we CAN jump. */
4904	if (mcnt)
4905	{
4906	mcnt--;
4907	STORE_NUMBER (p + 2, mcnt);
4908	#ifdef _LIBC
4909	DEBUG_PRINT3 (" Setting %p to %d.\n", p + 2, mcnt);
4910	#else
4911	DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p + 2, mcnt);
4912	#endif
4913	goto unconditional_jump;
4914	}
4915	/* If don't have to jump any more, skip over the rest of command. */
4916	else
4917	p += 4;
4918	break;
4919
4920	case set_number_at:
4921	{
4922	DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4923
4924	EXTRACT_NUMBER_AND_INCR (mcnt, p);
4925	p1 = p + mcnt;
4926	EXTRACT_NUMBER_AND_INCR (mcnt, p);
4927	#ifdef _LIBC
4928	DEBUG_PRINT3 (" Setting %p to %d.\n", p1, mcnt);
4929	#else
4930	DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4931	#endif
4932	STORE_NUMBER (p1, mcnt);
4933	break;
4934	}
4935
4936	#if 0
4937	/* The DEC Alpha C compiler 3.x generates incorrect code for the
4938	test WORDCHAR_P (d - 1) != WORDCHAR_P (d) in the expansion of
4939	AT_WORD_BOUNDARY, so this code is disabled. Expanding the
4940	macro and introducing temporary variables works around the bug. */
4941
4942	case wordbound:
4943	DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4944	if (AT_WORD_BOUNDARY (d))
4945	break;
4946	goto fail;
4947
4948	case notwordbound:
4949	DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4950	if (AT_WORD_BOUNDARY (d))
4951	goto fail;
4952	break;
4953	#else
4954	case wordbound:
4955	{
4956	boolean prevchar, thischar;
4957
4958	DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4959	if (AT_STRINGS_BEG (d) \|\| AT_STRINGS_END (d))
4960	break;
4961
4962	prevchar = WORDCHAR_P (d - 1);
4963	thischar = WORDCHAR_P (d);
4964	if (prevchar != thischar)
4965	break;
4966	goto fail;
4967	}
4968
4969	case notwordbound:
4970	{
4971	boolean prevchar, thischar;
4972
4973	DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4974	if (AT_STRINGS_BEG (d) \|\| AT_STRINGS_END (d))
4975	goto fail;
4976
4977	prevchar = WORDCHAR_P (d - 1);
4978	thischar = WORDCHAR_P (d);
4979	if (prevchar != thischar)
4980	goto fail;
4981	break;
4982	}
4983	#endif
4984
4985	case wordbeg:
4986	DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4987	if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) \|\| !WORDCHAR_P (d - 1)))
4988	break;
4989	goto fail;
4990
4991	case wordend:
4992	DEBUG_PRINT1 ("EXECUTING wordend.\n");
4993	if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4994	&& (!WORDCHAR_P (d) \|\| AT_STRINGS_END (d)))
4995	break;
4996	goto fail;
4997
4998	#ifdef emacs
4999	case before_dot:
5000	DEBUG_PRINT1 ("EXECUTING before_dot.\n");
5001	if (PTR_CHAR_POS ((unsigned char *) d) >= point)
5002	goto fail;
5003	break;
5004
5005	case at_dot:
5006	DEBUG_PRINT1 ("EXECUTING at_dot.\n");
5007	if (PTR_CHAR_POS ((unsigned char *) d) != point)
5008	goto fail;
5009	break;
5010
5011	case after_dot:
5012	DEBUG_PRINT1 ("EXECUTING after_dot.\n");
5013	if (PTR_CHAR_POS ((unsigned char *) d) <= point)
5014	goto fail;
5015	break;
5016
5017	case syntaxspec:
5018	DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
5019	mcnt = *p++;
5020	goto matchsyntax;
5021
5022	case wordchar:
5023	DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
5024	mcnt = (int) Sword;
5025	matchsyntax:
5026	PREFETCH ();
5027	/* Can't use d++ here; SYNTAX may be an unsafe macro. /
5028	d++;
5029	if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
5030	goto fail;
5031	SET_REGS_MATCHED ();
5032	break;
5033
5034	case notsyntaxspec:
5035	DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
5036	mcnt = *p++;
5037	goto matchnotsyntax;
5038
5039	case notwordchar:
5040	DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
5041	mcnt = (int) Sword;
5042	matchnotsyntax:
5043	PREFETCH ();
5044	/* Can't use d++ here; SYNTAX may be an unsafe macro. /
5045	d++;
5046	if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
5047	goto fail;
5048	SET_REGS_MATCHED ();
5049	break;
5050
5051	#else /* not emacs */
5052	case wordchar:
5053	DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
5054	PREFETCH ();
5055	if (!WORDCHAR_P (d))
5056	goto fail;
5057	SET_REGS_MATCHED ();
5058	d++;
5059	break;
5060
5061	case notwordchar:
5062	DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
5063	PREFETCH ();
5064	if (WORDCHAR_P (d))
5065	goto fail;
5066	SET_REGS_MATCHED ();
5067	d++;
5068	break;
5069	#endif /* not emacs */
5070
5071	default:
5072	abort ();
5073	}
5074	continue; /* Successfully executed one pattern command; keep going. */
5075
5076
5077	/* We goto here if a matching operation fails. */
5078	fail:
5079	if (!FAIL_STACK_EMPTY ())
5080	{ /* A restart point is known. Restore to that state. */
5081	DEBUG_PRINT1 ("\nFAIL:\n");
5082	POP_FAILURE_POINT (d, p,
5083	lowest_active_reg, highest_active_reg,
5084	regstart, regend, reg_info);
5085
5086	/* If this failure point is a dummy, try the next one. */
5087	if (!p)
5088	goto fail;
5089
5090	/* If we failed to the end of the pattern, don't examine p. /
5091	assert (p <= pend);
5092	if (p < pend)
5093	{
5094	boolean is_a_jump_n = false;
5095
5096	/* If failed to a backwards jump that's part of a repetition
5097	loop, need to pop this failure point and use the next one. */
5098	switch ((re_opcode_t) *p)
5099	{
5100	case jump_n:
5101	is_a_jump_n = true;
5102	case maybe_pop_jump:
5103	case pop_failure_jump:
5104	case jump:
5105	p1 = p + 1;
5106	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5107	p1 += mcnt;
5108
5109	if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
5110	\|\| (!is_a_jump_n
5111	&& (re_opcode_t) *p1 == on_failure_jump))
5112	goto fail;
5113	break;
5114	default:
5115	/* do nothing */ ;
5116	}
5117	}
5118
5119	if (d >= string1 && d <= end1)
5120	dend = end_match_1;
5121	}
5122	else
5123	break; /* Matching at this starting point really fails. */
5124	} /* for (;;) */
5125
5126	if (best_regs_set)
5127	goto restore_best_regs;
5128
5129	FREE_VARIABLES ();
5130
5131	return -1; /* Failure to match. */
5132	} /* re_match_2 */
5133
5134	/* Subroutine definitions for re_match_2. */
5135
5136
5137	/* We are passed P pointing to a register number after a start_memory.
5138
5139	Return true if the pattern up to the corresponding stop_memory can
5140	match the empty string, and false otherwise.
5141
5142	If we find the matching stop_memory, sets P to point to one past its number.
5143	Otherwise, sets P to an undefined byte less than or equal to END.
5144
5145	We don't handle duplicates properly (yet). */
5146
5147	static boolean
5148	group_match_null_string_p (p, end, reg_info)
5149	unsigned char *p, end;
5150	register_info_type *reg_info;
5151	{
5152	int mcnt;
5153	/* Point to after the args to the start_memory. */
5154	unsigned char p1 = p + 2;
5155
5156	while (p1 < end)
5157	{
5158	/* Skip over opcodes that can match nothing, and return true or
5159	false, as appropriate, when we get to one that can't, or to the
5160	matching stop_memory. */
5161
5162	switch ((re_opcode_t) *p1)
5163	{
5164	/* Could be either a loop or a series of alternatives. */
5165	case on_failure_jump:
5166	p1++;
5167	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5168
5169	/* If the next operation is not a jump backwards in the
5170	pattern. */
5171
5172	if (mcnt >= 0)
5173	{
5174	/* Go through the on_failure_jumps of the alternatives,
5175	seeing if any of the alternatives cannot match nothing.
5176	The last alternative starts with only a jump,
5177	whereas the rest start with on_failure_jump and end
5178	with a jump, e.g., here is the pattern for `a\|b\|c':
5179
5180	/on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
5181	/on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
5182	/exactn/1/c
5183
5184	So, we have to first go through the first (n-1)
5185	alternatives and then deal with the last one separately. */
5186
5187
5188	/* Deal with the first (n-1) alternatives, which start
5189	with an on_failure_jump (see above) that jumps to right
5190	past a jump_past_alt. */
5191
5192	while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
5193	{
5194	/* `mcnt' holds how many bytes long the alternative
5195	is, including the ending `jump_past_alt' and
5196	its number. */
5197
5198	if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
5199	reg_info))
5200	return false;
5201
5202	/* Move to right after this alternative, including the
5203	jump_past_alt. */
5204	p1 += mcnt;
5205
5206	/* Break if it's the beginning of an n-th alternative
5207	that doesn't begin with an on_failure_jump. */
5208	if ((re_opcode_t) *p1 != on_failure_jump)
5209	break;
5210
5211	/* Still have to check that it's not an n-th
5212	alternative that starts with an on_failure_jump. */
5213	p1++;
5214	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5215	if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
5216	{
5217	/* Get to the beginning of the n-th alternative. */
5218	p1 -= 3;
5219	break;
5220	}
5221	}
5222
5223	/* Deal with the last alternative: go back and get number
5224	of the `jump_past_alt' just before it. `mcnt' contains
5225	the length of the alternative. */
5226	EXTRACT_NUMBER (mcnt, p1 - 2);
5227
5228	if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
5229	return false;
5230
5231	p1 += mcnt; /* Get past the n-th alternative. */
5232	} /* if mcnt > 0 */
5233	break;
5234
5235
5236	case stop_memory:
5237	assert (p1[1] == **p);
5238	*p = p1 + 2;
5239	return true;
5240
5241
5242	default:
5243	if (!common_op_match_null_string_p (&p1, end, reg_info))
5244	return false;
5245	}
5246	} /* while p1 < end */
5247
5248	return false;
5249	} /* group_match_null_string_p */
5250
5251
5252	/* Similar to group_match_null_string_p, but doesn't deal with alternatives:
5253	It expects P to be the first byte of a single alternative and END one
5254	byte past the last. The alternative can contain groups. */
5255
5256	static boolean
5257	alt_match_null_string_p (p, end, reg_info)
5258	unsigned char p, end;
5259	register_info_type *reg_info;
5260	{
5261	int mcnt;
5262	unsigned char *p1 = p;
5263
5264	while (p1 < end)
5265	{
5266	/* Skip over opcodes that can match nothing, and break when we get
5267	to one that can't. */
5268
5269	switch ((re_opcode_t) *p1)
5270	{
5271	/* It's a loop. */
5272	case on_failure_jump:
5273	p1++;
5274	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5275	p1 += mcnt;
5276	break;
5277
5278	default:
5279	if (!common_op_match_null_string_p (&p1, end, reg_info))
5280	return false;
5281	}
5282	} /* while p1 < end */
5283
5284	return true;
5285	} /* alt_match_null_string_p */
5286
5287
5288	/* Deals with the ops common to group_match_null_string_p and
5289	alt_match_null_string_p.
5290
5291	Sets P to one after the op and its arguments, if any. */
5292
5293	static boolean
5294	common_op_match_null_string_p (p, end, reg_info)
5295	unsigned char *p, end;
5296	register_info_type *reg_info;
5297	{
5298	int mcnt;
5299	boolean ret;
5300	int reg_no;
5301	unsigned char p1 = p;
5302
5303	switch ((re_opcode_t) *p1++)
5304	{
5305	case no_op:
5306	case begline:
5307	case endline:
5308	case begbuf:
5309	case endbuf:
5310	case wordbeg:
5311	case wordend:
5312	case wordbound:
5313	case notwordbound:
5314	#ifdef emacs
5315	case before_dot:
5316	case at_dot:
5317	case after_dot:
5318	#endif
5319	break;
5320
5321	case start_memory:
5322	reg_no = *p1;
5323	assert (reg_no > 0 && reg_no <= MAX_REGNUM);
5324	ret = group_match_null_string_p (&p1, end, reg_info);
5325
5326	/* Have to set this here in case we're checking a group which
5327	contains a group and a back reference to it. */
5328
5329	if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
5330	REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
5331
5332	if (!ret)
5333	return false;
5334	break;
5335
5336	/* If this is an optimized succeed_n for zero times, make the jump. */
5337	case jump:
5338	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5339	if (mcnt >= 0)
5340	p1 += mcnt;
5341	else
5342	return false;
5343	break;
5344
5345	case succeed_n:
5346	/* Get to the number of times to succeed. */
5347	p1 += 2;
5348	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5349
5350	if (mcnt == 0)
5351	{
5352	p1 -= 4;
5353	EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5354	p1 += mcnt;
5355	}
5356	else
5357	return false;
5358	break;
5359
5360	case duplicate:
5361	if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
5362	return false;
5363	break;
5364
5365	case set_number_at:
5366	p1 += 4;
5367
5368	default:
5369	/* All other opcodes mean we cannot match the empty string. */
5370	return false;
5371	}
5372
5373	*p = p1;
5374	return true;
5375	} /* common_op_match_null_string_p */
5376
5377
5378	/* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
5379	bytes; nonzero otherwise. */
5380
5381	static int
5382	bcmp_translate (s1, s2, len, translate)
5383	const char s1, s2;
5384	register int len;
5385	RE_TRANSLATE_TYPE translate;
5386	{
5387	register const unsigned char p1 = (const unsigned char ) s1;
5388	register const unsigned char p2 = (const unsigned char ) s2;
5389	while (len)
5390	{
5391	if (translate[p1++] != translate[p2++]) return 1;
5392	len--;
5393	}
5394	return 0;
5395	}
5396
5397	/* Entry points for GNU code. */
5398
5399	/* re_compile_pattern is the GNU regular expression compiler: it
5400	compiles PATTERN (of length SIZE) and puts the result in BUFP.
5401	Returns 0 if the pattern was valid, otherwise an error string.
5402
5403	Assumes the `allocated' (and perhaps `buffer') and `translate' fields
5404	are set in BUFP on entry.
5405
5406	We call regex_compile to do the actual compilation. */
5407
5408	const char *
5409	re_compile_pattern (pattern, length, bufp)
5410	const char *pattern;
5411	size_t length;
5412	struct re_pattern_buffer *bufp;
5413	{
5414	reg_errcode_t ret;
5415
5416	/* GNU code is written to assume at least RE_NREGS registers will be set
5417	(and at least one extra will be -1). */
5418	bufp->regs_allocated = REGS_UNALLOCATED;
5419
5420	/* And GNU code determines whether or not to get register information
5421	by passing null for the REGS argument to re_match, etc., not by
5422	setting no_sub. */
5423	bufp->no_sub = 0;
5424
5425	/* Match anchors at newline. */
5426	bufp->newline_anchor = 1;
5427
5428	ret = regex_compile (pattern, length, re_syntax_options, bufp);
5429
5430	if (!ret)
5431	return NULL;
5432	return gettext (re_error_msgid[(int) ret]);
5433	}
5434
5435	/* Entry points compatible with 4.2 BSD regex library. We don't define
5436	them unless specifically requested. */
5437
5438	#if defined (_REGEX_RE_COMP) \|\| defined (_LIBC)
5439
5440	/* BSD has one and only one pattern buffer. */
5441	static struct re_pattern_buffer re_comp_buf;
5442
5443	char *
5444	#ifdef _LIBC
5445	/* Make these definitions weak in libc, so POSIX programs can redefine
5446	these names if they don't use our functions, and still use
5447	regcomp/regexec below without link errors. */
5448	weak_function
5449	#endif
5450	re_comp (s)
5451	const char *s;
5452	{
5453	reg_errcode_t ret;
5454
5455	if (!s)
5456	{
5457	if (!re_comp_buf.buffer)
5458	return gettext ("No previous regular expression");
5459	return 0;
5460	}
5461
5462	if (!re_comp_buf.buffer)
5463	{
5464	re_comp_buf.buffer = (unsigned char *) malloc (200);
5465	if (re_comp_buf.buffer == NULL)
5466	return gettext (re_error_msgid[(int) REG_ESPACE]);
5467	re_comp_buf.allocated = 200;
5468
5469	re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
5470	if (re_comp_buf.fastmap == NULL)
5471	return gettext (re_error_msgid[(int) REG_ESPACE]);
5472	}
5473
5474	/* Since `re_exec' always passes NULL for the `regs' argument, we
5475	don't need to initialize the pattern buffer fields which affect it. */
5476
5477	/* Match anchors at newlines. */
5478	re_comp_buf.newline_anchor = 1;
5479
5480	ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
5481
5482	if (!ret)
5483	return NULL;
5484
5485	/* Yes, we're discarding `const' here if !HAVE_LIBINTL. */
5486	return (char *) gettext (re_error_msgid[(int) ret]);
5487	}
5488
5489
5490	int
5491	#ifdef _LIBC
5492	weak_function
5493	#endif
5494	re_exec (s)
5495	const char *s;
5496	{
5497	const int len = strlen (s);
5498	return
5499	0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
5500	}
5501
5502	#endif /* _REGEX_RE_COMP */
5503
5504	/* POSIX.2 functions. Don't define these for Emacs. */
5505
5506	#ifndef emacs
5507
5508	/* regcomp takes a regular expression as a string and compiles it.
5509
5510	PREG is a regex_t *. We do not expect any fields to be initialized,
5511	since POSIX says we shouldn't. Thus, we set
5512
5513	`buffer' to the compiled pattern;
5514	`used' to the length of the compiled pattern;
5515	`syntax' to RE_SYNTAX_POSIX_EXTENDED if the
5516	REG_EXTENDED bit in CFLAGS is set; otherwise, to
5517	RE_SYNTAX_POSIX_BASIC;
5518	`newline_anchor' to REG_NEWLINE being set in CFLAGS;
5519	`fastmap' and `fastmap_accurate' to zero;
5520	`re_nsub' to the number of subexpressions in PATTERN.
5521
5522	PATTERN is the address of the pattern string.
5523
5524	CFLAGS is a series of bits which affect compilation.
5525
5526	If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
5527	use POSIX basic syntax.
5528
5529	If REG_NEWLINE is set, then . and [^...] don't match newline.
5530	Also, regexec will try a match beginning after every newline.
5531
5532	If REG_ICASE is set, then we considers upper- and lowercase
5533	versions of letters to be equivalent when matching.
5534
5535	If REG_NOSUB is set, then when PREG is passed to regexec, that
5536	routine will report only success or failure, and nothing about the
5537	registers.
5538
5539	It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
5540	the return codes and their meanings.) */
5541
5542	int
5543	regcomp (preg, pattern, cflags)
5544	regex_t *preg;
5545	const char *pattern;
5546	int cflags;
5547	{
5548	reg_errcode_t ret;
5549	reg_syntax_t syntax
5550	= (cflags & REG_EXTENDED) ?
5551	RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
5552
5553	/* regex_compile will allocate the space for the compiled pattern. */
5554	preg->buffer = 0;
5555	preg->allocated = 0;
5556	preg->used = 0;
5557
5558	/* Don't bother to use a fastmap when searching. This simplifies the
5559	REG_NEWLINE case: if we used a fastmap, we'd have to put all the
5560	characters after newlines into the fastmap. This way, we just try
5561	every character. */
5562	preg->fastmap = 0;
5563
5564	if (cflags & REG_ICASE)
5565	{
5566	unsigned i;
5567
5568	preg->translate
5569	= (RE_TRANSLATE_TYPE) malloc (CHAR_SET_SIZE
5570	* sizeof (*(RE_TRANSLATE_TYPE)0));
5571	if (preg->translate == NULL)
5572	return (int) REG_ESPACE;
5573
5574	/* Map uppercase characters to corresponding lowercase ones. */
5575	for (i = 0; i < CHAR_SET_SIZE; i++)
5576	preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
5577	}
5578	else
5579	preg->translate = NULL;
5580
5581	/* If REG_NEWLINE is set, newlines are treated differently. */
5582	if (cflags & REG_NEWLINE)
5583	{ /* REG_NEWLINE implies neither . nor [^...] match newline. */
5584	syntax &= ~RE_DOT_NEWLINE;
5585	syntax \|= RE_HAT_LISTS_NOT_NEWLINE;
5586	/* It also changes the matching behavior. */
5587	preg->newline_anchor = 1;
5588	}
5589	else
5590	preg->newline_anchor = 0;
5591
5592	preg->no_sub = !!(cflags & REG_NOSUB);
5593
5594	/* POSIX says a null character in the pattern terminates it, so we
5595	can use strlen here in compiling the pattern. */
5596	ret = regex_compile (pattern, strlen (pattern), syntax, preg);
5597
5598	/* POSIX doesn't distinguish between an unmatched open-group and an
5599	unmatched close-group: both are REG_EPAREN. */
5600	if (ret == REG_ERPAREN) ret = REG_EPAREN;
5601
5602	return (int) ret;
5603	}
5604
5605
5606	/* regexec searches for a given pattern, specified by PREG, in the
5607	string STRING.
5608
5609	If NMATCH is zero or REG_NOSUB was set in the cflags argument to
5610	`regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
5611	least NMATCH elements, and we set them to the offsets of the
5612	corresponding matched substrings.
5613
5614	EFLAGS specifies `execution flags' which affect matching: if
5615	REG_NOTBOL is set, then ^ does not match at the beginning of the
5616	string; if REG_NOTEOL is set, then $ does not match at the end.
5617
5618	We return 0 if we find a match and REG_NOMATCH if not. */
5619
5620	int
5621	regexec (preg, string, nmatch, pmatch, eflags)
5622	const regex_t *preg;
5623	const char *string;
5624	size_t nmatch;
5625	regmatch_t pmatch[];
5626	int eflags;
5627	{
5628	int ret;
5629	struct re_registers regs;
5630	regex_t private_preg;
5631	int len = strlen (string);
5632	boolean want_reg_info = !preg->no_sub && nmatch > 0;
5633
5634	private_preg = *preg;
5635
5636	private_preg.not_bol = !!(eflags & REG_NOTBOL);
5637	private_preg.not_eol = !!(eflags & REG_NOTEOL);
5638
5639	/* The user has told us exactly how many registers to return
5640	information about, via `nmatch'. We have to pass that on to the
5641	matching routines. */
5642	private_preg.regs_allocated = REGS_FIXED;
5643
5644	if (want_reg_info)
5645	{
5646	regs.num_regs = nmatch;
5647	regs.start = TALLOC (nmatch, regoff_t);
5648	regs.end = TALLOC (nmatch, regoff_t);
5649	if (regs.start == NULL \|\| regs.end == NULL)
5650	return (int) REG_NOMATCH;
5651	}
5652
5653	/* Perform the searching operation. */
5654	ret = re_search (&private_preg, string, len,
5655	/* start: / 0, / range: */ len,
5656	want_reg_info ? &regs : (struct re_registers *) 0);
5657
5658	/* Copy the register information to the POSIX structure. */
5659	if (want_reg_info)
5660	{
5661	if (ret >= 0)
5662	{
5663	unsigned r;
5664
5665	for (r = 0; r < nmatch; r++)
5666	{
5667	pmatch[r].rm_so = regs.start[r];
5668	pmatch[r].rm_eo = regs.end[r];
5669	}
5670	}
5671
5672	/* If we needed the temporary register info, free the space now. */
5673	free (regs.start);
5674	free (regs.end);
5675	}
5676
5677	/* We want zero return to mean success, unlike `re_search'. */
5678	return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5679	}
5680
5681
5682	/* Returns a message corresponding to an error code, ERRCODE, returned
5683	from either regcomp or regexec. We don't use PREG here. */
5684
5685	size_t
5686	regerror (errcode, preg, errbuf, errbuf_size)
5687	int errcode;
5688	const regex_t *preg;
5689	char *errbuf;
5690	size_t errbuf_size;
5691	{
5692	const char *msg;
5693	size_t msg_size;
5694
5695	if (errcode < 0
5696	\|\| errcode >= (int) (sizeof (re_error_msgid)
5697	/ sizeof (re_error_msgid[0])))
5698	/* Only error codes returned by the rest of the code should be passed
5699	to this routine. If we are given anything else, or if other regex
5700	code generates an invalid error code, then the program has a bug.
5701	Dump core so we can fix it. */
5702	abort ();
5703
5704	msg = gettext (re_error_msgid[errcode]);
5705
5706	msg_size = strlen (msg) + 1; /* Includes the null. */
5707
5708	if (errbuf_size != 0)
5709	{
5710	if (msg_size > errbuf_size)
5711	{
5712	strncpy (errbuf, msg, errbuf_size - 1);
5713	errbuf[errbuf_size - 1] = 0;
5714	}
5715	else
5716	strcpy (errbuf, msg);
5717	}
5718
5719	return msg_size;
5720	}
5721
5722
5723	/* Free dynamically allocated space used by PREG. */
5724
5725	void
5726	regfree (preg)
5727	regex_t *preg;
5728	{
5729	if (preg->buffer != NULL)
5730	free (preg->buffer);
5731	preg->buffer = NULL;
5732
5733	preg->allocated = 0;
5734	preg->used = 0;
5735
5736	if (preg->fastmap != NULL)
5737	free (preg->fastmap);
5738	preg->fastmap = NULL;
5739	preg->fastmap_accurate = 0;
5740
5741	if (preg->translate != NULL)
5742	free (preg->translate);
5743	preg->translate = NULL;
5744	}
5745
5746	#endif /* not emacs */

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source: trunk/third/enscript/compat/regex.c @ 17620

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