1 /* Extended regular expression matching and search library,
3 * (Implements POSIX draft P1003.2/D11.2, except for some of the
4 * internationalization features.)
6 * Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
8 * This file is part of the GNU C Library. Its master source is NOT part of
9 * the C library, however. The master source lives in /gd/gnu/lib.
11 * The GNU C Library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Library General Public License as
13 * published by the Free Software Foundation; either version 2 of the
14 * License, or (at your option) any later version.
16 * The GNU C Library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Library General Public License for more details.
21 * You should have received a copy of the GNU Library General Public
22 * License along with the GNU C Library; see the file COPYING.LIB. If not,
23 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 * Boston, MA 02111-1307, USA.
30 * Use _regex.h instead of regex.h. tlr, 1999-01-06
31 * Make REGEX_MALLOC depend on HAVE_ALLOCA &c.
33 * Don't switch on regex debugging when debugging mutt.
37 /* The following doesn't mix too well with autoconfiguring
38 * the use of alloca. So let's disable it for AIX.
43 /* AIX requires this to be the first thing in the file. */
44 # if defined (_AIX) && !defined (REGEX_MALLOC)
59 #if (defined(HAVE_ALLOCA_H) && !defined(_AIX))
63 #if (!defined(HAVE_ALLOCA) || defined(_AIX))
67 #if defined(STDC_HEADERS) && !defined(emacs)
70 /* We need this for `regex.h', and perhaps for the Emacs include files. */
71 #include <sys/types.h>
74 /* For platform which support the ISO C amendement 1 functionality we
75 support user defined character classes. */
76 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
81 /* This is for other GNU distributions with internationalized messages. */
82 #if HAVE_LIBINTL_H || defined (_LIBC)
85 # define gettext(msgid) (msgid)
89 /* This define is so xgettext can find the internationalizable
91 #define gettext_noop(String) String
94 /* The `emacs' switch turns on certain matching commands
95 that make sense only in Emacs. */
102 #else /* not emacs */
104 /* If we are not linking with Emacs proper,
105 we can't use the relocating allocator
106 even if config.h says that we can. */
109 #if defined (STDC_HEADERS) || defined (_LIBC)
112 char *malloc (); /* __MEM_CHECKED__ */
113 char *realloc (); /* __MEM_CHECKED__ */
116 /* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
117 If nothing else has been done, use the method below. */
118 #ifdef INHIBIT_STRING_HEADER
119 #if !(defined (HAVE_BZERO) && defined (HAVE_BCOPY))
120 #if !defined (bzero) && !defined (bcopy)
121 #undef INHIBIT_STRING_HEADER
126 /* This is the normal way of making sure we have a bcopy and a bzero.
127 This is used in most programs--a few other programs avoid this
128 by defining INHIBIT_STRING_HEADER. */
129 #ifndef INHIBIT_STRING_HEADER
130 #if defined (HAVE_STRING_H) || defined (STDC_HEADERS) || defined (_LIBC)
133 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
136 #define bcopy(s, d, n) memcpy ((d), (s), (n))
139 #define bzero(s, n) memset ((s), 0, (n))
146 /* Define the syntax stuff for \<, \>, etc. */
148 /* This must be nonzero for the wordchar and notwordchar pattern
149 commands in re_match_2. */
154 #ifdef SWITCH_ENUM_BUG
155 #define SWITCH_ENUM_CAST(x) ((int)(x))
157 #define SWITCH_ENUM_CAST(x) (x)
162 extern char *re_syntax_table;
164 #else /* not SYNTAX_TABLE */
166 /* How many characters in the character set. */
167 #define CHAR_SET_SIZE 256
169 static char re_syntax_table[CHAR_SET_SIZE];
172 1, MUTT_ALPHA, MUTT_BLANK, MUTT_CNTRL, MUTT_DIGIT, MUTT_GRAPH,
173 MUTT_LOWER, MUTT_PRINT, MUTT_PUNCT, MUTT_SPACE, MUTT_UPPER, MUTT_XDIGIT,
177 static int ctype (const char *name)
179 if (0 == strcmp (name, "alnum"))
181 if (0 == strcmp (name, "alpha"))
183 if (0 == strcmp (name, "blank"))
185 if (0 == strcmp (name, "cntrl"))
187 if (0 == strcmp (name, "digit"))
189 if (0 == strcmp (name, "graph"))
191 if (0 == strcmp (name, "lower"))
193 if (0 == strcmp (name, "print"))
195 if (0 == strcmp (name, "punct"))
197 if (0 == strcmp (name, "space"))
199 if (0 == strcmp (name, "upper"))
201 if (0 == strcmp (name, "xdigit"))
207 static void init_syntax_once ()
215 bzero (re_syntax_table, sizeof re_syntax_table);
217 for (c = 'a'; c <= 'z'; c++)
218 re_syntax_table[c] = Sword;
220 for (c = 'A'; c <= 'Z'; c++)
221 re_syntax_table[c] = Sword;
223 for (c = '0'; c <= '9'; c++)
224 re_syntax_table[c] = Sword;
226 re_syntax_table['_'] = Sword;
231 #endif /* not SYNTAX_TABLE */
233 #define SYNTAX(c) re_syntax_table[c]
235 #endif /* not emacs */
237 /* Get the interface, including the syntax bits. */
239 /* Changed to fit into mutt - tlr, 1999-01-06 */
243 /* isalpha etc. are used for the character classes. */
246 /* Jim Meyering writes:
248 "... Some ctype macros are valid only for character codes that
249 isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
250 using /bin/cc or gcc but without giving an ansi option). So, all
251 ctype uses should be through macros like ISPRINT... If
252 STDC_HEADERS is defined, then autoconf has verified that the ctype
253 macros don't need to be guarded with references to isascii. ...
254 Defining isascii to 1 should let any compiler worth its salt
255 eliminate the && through constant folding." */
257 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
260 #define ISASCII(c) isascii(c)
264 #define ISBLANK(c) (ISASCII (c) && isblank (c))
266 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
269 #define ISGRAPH(c) (ISASCII (c) && isgraph (c))
271 #define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
274 #define ISPRINT(c) (ISASCII (c) && isprint (c))
275 #define ISDIGIT(c) (ISASCII (c) && isdigit (c))
276 #define ISALNUM(c) (ISASCII (c) && isalnum (c))
277 #define ISALPHA(c) (ISASCII (c) && isalpha (c))
278 #define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
279 #define ISLOWER(c) (ISASCII (c) && islower (c))
280 #define ISPUNCT(c) (ISASCII (c) && ispunct (c))
281 #define ISSPACE(c) (ISASCII (c) && isspace (c))
282 #define ISUPPER(c) (ISASCII (c) && isupper (c))
283 #define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
286 #define NULL (void *)0
289 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
290 since ours (we hope) works properly with all combinations of
291 machines, compilers, `char' and `unsigned char' argument types.
292 (Per Bothner suggested the basic approach.) */
293 #undef SIGN_EXTEND_CHAR
295 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
296 #else /* not __STDC__ */
297 /* As in Harbison and Steele. */
298 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
301 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
302 use `alloca' instead of `malloc'. This is because using malloc in
303 re_search* or re_match* could cause memory leaks when C-g is used in
304 Emacs; also, malloc is slower and causes storage fragmentation. On
305 the other hand, malloc is more portable, and easier to debug.
307 Because we sometimes use alloca, some routines have to be macros,
308 not functions -- `alloca'-allocated space disappears at the end of the
309 function it is called in. */
313 #define REGEX_ALLOCATE malloc
314 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
315 #define REGEX_FREE free
317 #else /* not REGEX_MALLOC */
319 /* Emacs already defines alloca, sometimes. */
322 /* Make alloca work the best possible way. */
324 #define alloca __builtin_alloca
325 #else /* not __GNUC__ */
328 #else /* not __GNUC__ or HAVE_ALLOCA_H */
329 #if 0 /* It is a bad idea to declare alloca. We always cast the result. */
330 #ifndef _AIX /* Already did AIX, up at the top. */
332 #endif /* not _AIX */
334 #endif /* not HAVE_ALLOCA_H */
335 #endif /* not __GNUC__ */
337 #endif /* not alloca */
339 #define REGEX_ALLOCATE alloca
341 /* Assumes a `char *destination' variable. */
342 #define REGEX_REALLOCATE(source, osize, nsize) \
343 (destination = (char *) alloca (nsize), \
344 bcopy (source, destination, osize), \
347 /* No need to do anything to free, after alloca. */
348 #define REGEX_FREE(arg) ((void)0) /* Do nothing! But inhibit gcc warning. */
350 #endif /* not REGEX_MALLOC */
352 /* Define how to allocate the failure stack. */
354 #if defined (REL_ALLOC) && defined (REGEX_MALLOC)
356 #define REGEX_ALLOCATE_STACK(size) \
357 r_alloc (&failure_stack_ptr, (size))
358 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
359 r_re_alloc (&failure_stack_ptr, (nsize))
360 #define REGEX_FREE_STACK(ptr) \
361 r_alloc_free (&failure_stack_ptr)
363 #else /* not using relocating allocator */
367 #define REGEX_ALLOCATE_STACK malloc
368 #define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
369 #define REGEX_FREE_STACK free
371 #else /* not REGEX_MALLOC */
373 #define REGEX_ALLOCATE_STACK alloca
375 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
376 REGEX_REALLOCATE (source, osize, nsize)
377 /* No need to explicitly free anything. */
378 #define REGEX_FREE_STACK(arg)
380 #endif /* not REGEX_MALLOC */
381 #endif /* not using relocating allocator */
384 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
385 `string1' or just past its end. This works if PTR is NULL, which is
387 #define FIRST_STRING_P(ptr) \
388 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
390 /* (Re)Allocate N items of type T using malloc, or fail. */
391 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
392 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
393 #define RETALLOC_IF(addr, n, t) \
394 if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
395 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
397 #define BYTEWIDTH 8 /* In bits. */
399 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
403 #define MAX(a, b) ((a) > (b) ? (a) : (b))
404 #define MIN(a, b) ((a) < (b) ? (a) : (b))
406 typedef char boolean;
411 static int re_match_2_internal ();
413 /* These are the command codes that appear in compiled regular
414 expressions. Some opcodes are followed by argument bytes. A
415 command code can specify any interpretation whatsoever for its
416 arguments. Zero bytes may appear in the compiled regular expression. */
421 /* Succeed right away--no more backtracking. */
424 /* Followed by one byte giving n, then by n literal bytes. */
427 /* Matches any (more or less) character. */
430 /* Matches any one char belonging to specified set. First
431 following byte is number of bitmap bytes. Then come bytes
432 for a bitmap saying which chars are in. Bits in each byte
433 are ordered low-bit-first. A character is in the set if its
434 bit is 1. A character too large to have a bit in the map is
435 automatically not in the set. */
438 /* Same parameters as charset, but match any character that is
439 not one of those specified. */
442 /* Start remembering the text that is matched, for storing in a
443 register. Followed by one byte with the register number, in
444 the range 0 to one less than the pattern buffer's re_nsub
445 field. Then followed by one byte with the number of groups
446 inner to this one. (This last has to be part of the
447 start_memory only because we need it in the on_failure_jump
451 /* Stop remembering the text that is matched and store it in a
452 memory register. Followed by one byte with the register
453 number, in the range 0 to one less than `re_nsub' in the
454 pattern buffer, and one byte with the number of inner groups,
455 just like `start_memory'. (We need the number of inner
456 groups here because we don't have any easy way of finding the
457 corresponding start_memory when we're at a stop_memory.) */
460 /* Match a duplicate of something remembered. Followed by one
461 byte containing the register number. */
464 /* Fail unless at beginning of line. */
467 /* Fail unless at end of line. */
470 /* Succeeds if at beginning of buffer (if emacs) or at beginning
471 of string to be matched (if not). */
474 /* Analogously, for end of buffer/string. */
477 /* Followed by two byte relative address to which to jump. */
480 /* Same as jump, but marks the end of an alternative. */
483 /* Followed by two-byte relative address of place to resume at
484 in case of failure. */
487 /* Like on_failure_jump, but pushes a placeholder instead of the
488 current string position when executed. */
489 on_failure_keep_string_jump,
491 /* Throw away latest failure point and then jump to following
492 two-byte relative address. */
495 /* Change to pop_failure_jump if know won't have to backtrack to
496 match; otherwise change to jump. This is used to jump
497 back to the beginning of a repeat. If what follows this jump
498 clearly won't match what the repeat does, such that we can be
499 sure that there is no use backtracking out of repetitions
500 already matched, then we change it to a pop_failure_jump.
501 Followed by two-byte address. */
504 /* Jump to following two-byte address, and push a dummy failure
505 point. This failure point will be thrown away if an attempt
506 is made to use it for a failure. A `+' construct makes this
507 before the first repeat. Also used as an intermediary kind
508 of jump when compiling an alternative. */
511 /* Push a dummy failure point and continue. Used at the end of
515 /* Followed by two-byte relative address and two-byte number n.
516 After matching N times, jump to the address upon failure. */
519 /* Followed by two-byte relative address, and two-byte number n.
520 Jump to the address N times, then fail. */
523 /* Set the following two-byte relative address to the
524 subsequent two-byte number. The address *includes* the two
528 wordchar, /* Matches any word-constituent character. */
529 notwordchar, /* Matches any char that is not a word-constituent. */
531 wordbeg, /* Succeeds if at word beginning. */
532 wordend, /* Succeeds if at word end. */
534 wordbound, /* Succeeds if at a word boundary. */
535 notwordbound /* Succeeds if not at a word boundary. */
537 , before_dot, /* Succeeds if before point. */
538 at_dot, /* Succeeds if at point. */
539 after_dot, /* Succeeds if after point. */
541 /* Matches any character whose syntax is specified. Followed by
542 a byte which contains a syntax code, e.g., Sword. */
545 /* Matches any character whose syntax is not that specified. */
550 /* Common operations on the compiled pattern. */
552 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
554 #define STORE_NUMBER(destination, number) \
556 (destination)[0] = (number) & 0377; \
557 (destination)[1] = (number) >> 8; \
560 /* Same as STORE_NUMBER, except increment DESTINATION to
561 the byte after where the number is stored. Therefore, DESTINATION
562 must be an lvalue. */
564 #define STORE_NUMBER_AND_INCR(destination, number) \
566 STORE_NUMBER (destination, number); \
567 (destination) += 2; \
570 /* Put into DESTINATION a number stored in two contiguous bytes starting
573 #define EXTRACT_NUMBER(destination, source) \
575 (destination) = *(source) & 0377; \
576 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
580 static void extract_number _RE_ARGS ((int *dest, unsigned char *source));
581 static void extract_number (dest, source)
583 unsigned char *source;
585 int temp = SIGN_EXTEND_CHAR (*(source + 1));
587 *dest = *source & 0377;
591 #ifndef EXTRACT_MACROS /* To debug the macros. */
592 #undef EXTRACT_NUMBER
593 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
594 #endif /* not EXTRACT_MACROS */
598 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
599 SOURCE must be an lvalue. */
601 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
603 EXTRACT_NUMBER (destination, source); \
608 static void extract_number_and_incr _RE_ARGS ((int *destination,
609 unsigned char **source));
610 static void extract_number_and_incr (destination, source)
612 unsigned char **source;
614 extract_number (destination, *source);
618 #ifndef EXTRACT_MACROS
619 #undef EXTRACT_NUMBER_AND_INCR
620 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
621 extract_number_and_incr (&dest, &src)
622 #endif /* not EXTRACT_MACROS */
626 /* If DEBUG is defined, Regex prints many voluminous messages about what
627 it is doing (if the variable `debug' is nonzero). If linked with the
628 main program in `iregex.c', you can enter patterns and strings
629 interactively. And if linked with the main program in `main.c' and
630 the other test files, you can run the already-written tests. */
634 /* We use standard I/O for debugging. */
637 /* It is useful to test things that ``must'' be true when debugging. */
640 static int debug = 0;
642 #define DEBUG_STATEMENT(e) e
643 #define DEBUG_PRINT1(x) if (debug) printf (x)
644 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
645 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
646 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
647 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
648 if (debug) print_partial_compiled_pattern (s, e)
649 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
650 if (debug) print_double_string (w, s1, sz1, s2, sz2)
653 /* Print the fastmap in human-readable form. */
655 void print_fastmap (fastmap)
658 unsigned was_a_range = 0;
661 while (i < (1 << BYTEWIDTH)) {
665 while (i < (1 << BYTEWIDTH) && fastmap[i]) {
679 /* Print a compiled pattern string in human-readable form, starting at
680 the START pointer into it and ending just before the pointer END. */
682 void print_partial_compiled_pattern (start, end)
683 unsigned char *start;
688 unsigned char *p = start;
689 unsigned char *pend = end;
696 /* Loop over pattern commands. */
698 printf ("%d:\t", p - start);
700 switch ((re_opcode_t) * p++) {
707 printf ("/exactn/%d", mcnt);
717 printf ("/start_memory/%d/%d", mcnt, *p++);
722 printf ("/stop_memory/%d/%d", mcnt, *p++);
726 printf ("/duplicate/%d", *p++);
736 register int c, last = -100;
737 register int in_range = 0;
739 printf ("/charset [%s",
740 (re_opcode_t) * (p - 1) == charset_not ? "^" : "");
742 assert (p + *p < pend);
744 for (c = 0; c < 256; c++)
745 if (c / 8 < *p && (p[1 + (c / 8)] & (1 << (c % 8)))) {
746 /* Are we starting a range? */
747 if (last + 1 == c && !in_range) {
751 /* Have we broken a range? */
752 else if (last + 1 != c && in_range) {
780 case on_failure_jump:
781 extract_number_and_incr (&mcnt, &p);
782 printf ("/on_failure_jump to %d", p + mcnt - start);
785 case on_failure_keep_string_jump:
786 extract_number_and_incr (&mcnt, &p);
787 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
790 case dummy_failure_jump:
791 extract_number_and_incr (&mcnt, &p);
792 printf ("/dummy_failure_jump to %d", p + mcnt - start);
795 case push_dummy_failure:
796 printf ("/push_dummy_failure");
800 extract_number_and_incr (&mcnt, &p);
801 printf ("/maybe_pop_jump to %d", p + mcnt - start);
804 case pop_failure_jump:
805 extract_number_and_incr (&mcnt, &p);
806 printf ("/pop_failure_jump to %d", p + mcnt - start);
810 extract_number_and_incr (&mcnt, &p);
811 printf ("/jump_past_alt to %d", p + mcnt - start);
815 extract_number_and_incr (&mcnt, &p);
816 printf ("/jump to %d", p + mcnt - start);
820 extract_number_and_incr (&mcnt, &p);
822 extract_number_and_incr (&mcnt2, &p);
823 printf ("/succeed_n to %d, %d times", p1 - start, mcnt2);
827 extract_number_and_incr (&mcnt, &p);
829 extract_number_and_incr (&mcnt2, &p);
830 printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
834 extract_number_and_incr (&mcnt, &p);
836 extract_number_and_incr (&mcnt2, &p);
837 printf ("/set_number_at location %d to %d", p1 - start, mcnt2);
841 printf ("/wordbound");
845 printf ("/notwordbound");
857 printf ("/before_dot");
865 printf ("/after_dot");
869 printf ("/syntaxspec");
871 printf ("/%d", mcnt);
875 printf ("/notsyntaxspec");
877 printf ("/%d", mcnt);
882 printf ("/wordchar");
886 printf ("/notwordchar");
898 printf ("?%d", *(p - 1));
904 printf ("%d:\tend of pattern.\n", p - start);
908 void print_compiled_pattern (bufp)
909 struct re_pattern_buffer *bufp;
911 unsigned char *buffer = bufp->buffer;
913 print_partial_compiled_pattern (buffer, buffer + bufp->used);
914 printf ("%ld bytes used/%ld bytes allocated.\n",
915 bufp->used, bufp->allocated);
917 if (bufp->fastmap_accurate && bufp->fastmap) {
918 printf ("fastmap: ");
919 print_fastmap (bufp->fastmap);
922 printf ("re_nsub: %d\t", bufp->re_nsub);
923 printf ("regs_alloc: %d\t", bufp->regs_allocated);
924 printf ("can_be_null: %d\t", bufp->can_be_null);
925 printf ("newline_anchor: %d\n", bufp->newline_anchor);
926 printf ("no_sub: %d\t", bufp->no_sub);
927 printf ("not_bol: %d\t", bufp->not_bol);
928 printf ("not_eol: %d\t", bufp->not_eol);
929 printf ("syntax: %lx\n", bufp->syntax);
930 /* Perhaps we should print the translate table? */
934 void print_double_string (where, string1, size1, string2, size2)
946 if (FIRST_STRING_P (where)) {
947 for (this_char = where - string1; this_char < size1; this_char++)
948 putchar (string1[this_char]);
953 for (this_char = where - string2; this_char < size2; this_char++)
954 putchar (string2[this_char]);
964 #else /* not DEBUG */
969 #define DEBUG_STATEMENT(e)
970 #define DEBUG_PRINT1(x)
971 #define DEBUG_PRINT2(x1, x2)
972 #define DEBUG_PRINT3(x1, x2, x3)
973 #define DEBUG_PRINT4(x1, x2, x3, x4)
974 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
975 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
977 #endif /* not DEBUG */
979 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
980 also be assigned to arbitrarily: each pattern buffer stores its own
981 syntax, so it can be changed between regex compilations. */
982 /* This has no initializer because initialized variables in Emacs
983 become read-only after dumping. */
984 reg_syntax_t re_syntax_options;
987 /* Specify the precise syntax of regexps for compilation. This provides
988 for compatibility for various utilities which historically have
989 different, incompatible syntaxes.
991 The argument SYNTAX is a bit mask comprised of the various bits
992 defined in regex.h. We return the old syntax. */
994 reg_syntax_t re_set_syntax (syntax)
997 reg_syntax_t ret = re_syntax_options;
999 re_syntax_options = syntax;
1001 if (syntax & RE_DEBUG)
1003 else if (debug) /* was on but now is not */
1009 /* This table gives an error message for each of the error codes listed
1010 in regex.h. Obviously the order here has to be same as there.
1011 POSIX doesn't require that we do anything for REG_NOERROR,
1012 but why not be nice? */
1014 static const char *re_error_msgid[] = {
1015 gettext_noop ("Success"), /* REG_NOERROR */
1016 gettext_noop ("No match"), /* REG_NOMATCH */
1017 gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
1018 gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
1019 gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
1020 gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
1021 gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
1022 gettext_noop ("Unmatched [ or [^"), /* REG_EBRACK */
1023 gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
1024 gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
1025 gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
1026 gettext_noop ("Invalid range end"), /* REG_ERANGE */
1027 gettext_noop ("Memory exhausted"), /* REG_ESPACE */
1028 gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
1029 gettext_noop ("Premature end of regular expression"), /* REG_EEND */
1030 gettext_noop ("Regular expression too big"), /* REG_ESIZE */
1031 gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
1034 /* Avoiding alloca during matching, to placate r_alloc. */
1036 /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
1037 searching and matching functions should not call alloca. On some
1038 systems, alloca is implemented in terms of malloc, and if we're
1039 using the relocating allocator routines, then malloc could cause a
1040 relocation, which might (if the strings being searched are in the
1041 ralloc heap) shift the data out from underneath the regexp
1044 Here's another reason to avoid allocation: Emacs
1045 processes input from X in a signal handler; processing X input may
1046 call malloc; if input arrives while a matching routine is calling
1047 malloc, then we're scrod. But Emacs can't just block input while
1048 calling matching routines; then we don't notice interrupts when
1049 they come in. So, Emacs blocks input around all regexp calls
1050 except the matching calls, which it leaves unprotected, in the
1051 faith that they will not malloc. */
1053 /* Normally, this is fine. */
1054 #define MATCH_MAY_ALLOCATE
1056 /* When using GNU C, we are not REALLY using the C alloca, no matter
1057 what config.h may say. So don't take precautions for it. */
1062 /* The match routines may not allocate if (1) they would do it with malloc
1063 and (2) it's not safe for them to use malloc.
1064 Note that if REL_ALLOC is defined, matching would not use malloc for the
1065 failure stack, but we would still use it for the register vectors;
1066 so REL_ALLOC should not affect this. */
1067 #if (defined (C_ALLOCA) || defined (REGEX_MALLOC)) && defined (emacs)
1068 #undef MATCH_MAY_ALLOCATE
1072 /* Failure stack declarations and macros; both re_compile_fastmap and
1073 re_match_2 use a failure stack. These have to be macros because of
1074 REGEX_ALLOCATE_STACK. */
1077 /* Number of failure points for which to initially allocate space
1078 when matching. If this number is exceeded, we allocate more
1079 space, so it is not a hard limit. */
1080 #ifndef INIT_FAILURE_ALLOC
1081 #define INIT_FAILURE_ALLOC 5
1084 /* Roughly the maximum number of failure points on the stack. Would be
1085 exactly that if always used MAX_FAILURE_ITEMS items each time we failed.
1086 This is a variable only so users of regex can assign to it; we never
1087 change it ourselves. */
1091 #if defined (MATCH_MAY_ALLOCATE)
1092 /* 4400 was enough to cause a crash on Alpha OSF/1,
1093 whose default stack limit is 2mb. */
1094 long int re_max_failures = 4000;
1096 long int re_max_failures = 2000;
1099 union fail_stack_elt {
1100 unsigned char *pointer;
1104 typedef union fail_stack_elt fail_stack_elt_t;
1107 fail_stack_elt_t *stack;
1108 unsigned long int size;
1109 unsigned long int avail; /* Offset of next open position. */
1112 #else /* not INT_IS_16BIT */
1114 #if defined (MATCH_MAY_ALLOCATE)
1115 /* 4400 was enough to cause a crash on Alpha OSF/1,
1116 whose default stack limit is 2mb. */
1117 int re_max_failures = 20000;
1119 int re_max_failures = 2000;
1122 union fail_stack_elt {
1123 unsigned char *pointer;
1127 typedef union fail_stack_elt fail_stack_elt_t;
1130 fail_stack_elt_t *stack;
1132 unsigned avail; /* Offset of next open position. */
1135 #endif /* INT_IS_16BIT */
1137 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
1138 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
1139 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
1142 /* Define macros to initialize and free the failure stack.
1143 Do `return -2' if the alloc fails. */
1145 #ifdef MATCH_MAY_ALLOCATE
1146 #define INIT_FAIL_STACK() \
1148 fail_stack.stack = (fail_stack_elt_t *) \
1149 REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
1151 if (fail_stack.stack == NULL) \
1154 fail_stack.size = INIT_FAILURE_ALLOC; \
1155 fail_stack.avail = 0; \
1158 #define RESET_FAIL_STACK() REGEX_FREE_STACK (fail_stack.stack)
1160 #define INIT_FAIL_STACK() \
1162 fail_stack.avail = 0; \
1165 #define RESET_FAIL_STACK()
1169 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
1171 Return 1 if succeeds, and 0 if either ran out of memory
1172 allocating space for it or it was already too large.
1174 REGEX_REALLOCATE_STACK requires `destination' be declared. */
1176 #define DOUBLE_FAIL_STACK(fail_stack) \
1177 ((fail_stack).size > (unsigned) (re_max_failures * MAX_FAILURE_ITEMS) \
1179 : ((fail_stack).stack = (fail_stack_elt_t *) \
1180 REGEX_REALLOCATE_STACK ((fail_stack).stack, \
1181 (fail_stack).size * sizeof (fail_stack_elt_t), \
1182 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
1184 (fail_stack).stack == NULL \
1186 : ((fail_stack).size <<= 1, \
1190 /* Push pointer POINTER on FAIL_STACK.
1191 Return 1 if was able to do so and 0 if ran out of memory allocating
1193 #define PUSH_PATTERN_OP(POINTER, FAIL_STACK) \
1194 ((FAIL_STACK_FULL () \
1195 && !DOUBLE_FAIL_STACK (FAIL_STACK)) \
1197 : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER, \
1200 /* Push a pointer value onto the failure stack.
1201 Assumes the variable `fail_stack'. Probably should only
1202 be called from within `PUSH_FAILURE_POINT'. */
1203 #define PUSH_FAILURE_POINTER(item) \
1204 fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
1206 /* This pushes an integer-valued item onto the failure stack.
1207 Assumes the variable `fail_stack'. Probably should only
1208 be called from within `PUSH_FAILURE_POINT'. */
1209 #define PUSH_FAILURE_INT(item) \
1210 fail_stack.stack[fail_stack.avail++].integer = (item)
1212 /* Push a fail_stack_elt_t value onto the failure stack.
1213 Assumes the variable `fail_stack'. Probably should only
1214 be called from within `PUSH_FAILURE_POINT'. */
1215 #define PUSH_FAILURE_ELT(item) \
1216 fail_stack.stack[fail_stack.avail++] = (item)
1218 /* These three POP... operations complement the three PUSH... operations.
1219 All assume that `fail_stack' is nonempty. */
1220 #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
1221 #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
1222 #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
1224 /* Used to omit pushing failure point id's when we're not debugging. */
1226 #define DEBUG_PUSH PUSH_FAILURE_INT
1227 #define DEBUG_POP(item_addr) (item_addr)->integer = POP_FAILURE_INT ()
1229 #define DEBUG_PUSH(item)
1230 #define DEBUG_POP(item_addr)
1234 /* Push the information about the state we will need
1235 if we ever fail back to it.
1237 Requires variables fail_stack, regstart, regend, reg_info, and
1238 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
1241 Does `return FAILURE_CODE' if runs out of memory. */
1243 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1245 char *destination; \
1246 /* Must be int, so when we don't save any registers, the arithmetic \
1247 of 0 + -1 isn't done as unsigned. */ \
1248 /* Can't be int, since there is not a shred of a guarantee that int \
1249 is wide enough to hold a value of something to which pointer can \
1253 DEBUG_STATEMENT (failure_id++); \
1254 DEBUG_STATEMENT (nfailure_points_pushed++); \
1255 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1256 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1257 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1259 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
1260 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1262 /* Ensure we have enough space allocated for what we will push. */ \
1263 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1265 if (!DOUBLE_FAIL_STACK (fail_stack)) \
1266 return failure_code; \
1268 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1269 (fail_stack).size); \
1270 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1273 /* Push the info, starting with the registers. */ \
1274 DEBUG_PRINT1 ("\n"); \
1277 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
1280 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
1281 DEBUG_STATEMENT (num_regs_pushed++); \
1283 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1284 PUSH_FAILURE_POINTER (regstart[this_reg]); \
1286 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1287 PUSH_FAILURE_POINTER (regend[this_reg]); \
1289 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
1290 DEBUG_PRINT2 (" match_null=%d", \
1291 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1292 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1293 DEBUG_PRINT2 (" matched_something=%d", \
1294 MATCHED_SOMETHING (reg_info[this_reg])); \
1295 DEBUG_PRINT2 (" ever_matched=%d", \
1296 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1297 DEBUG_PRINT1 ("\n"); \
1298 PUSH_FAILURE_ELT (reg_info[this_reg].word); \
1301 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
1302 PUSH_FAILURE_INT (lowest_active_reg); \
1304 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
1305 PUSH_FAILURE_INT (highest_active_reg); \
1307 DEBUG_PRINT2 (" Pushing pattern 0x%x:\n", pattern_place); \
1308 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1309 PUSH_FAILURE_POINTER (pattern_place); \
1311 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
1312 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1314 DEBUG_PRINT1 ("'\n"); \
1315 PUSH_FAILURE_POINTER (string_place); \
1317 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1318 DEBUG_PUSH (failure_id); \
1321 /* This is the number of items that are pushed and popped on the stack
1322 for each register. */
1323 #define NUM_REG_ITEMS 3
1325 /* Individual items aside from the registers. */
1327 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1329 #define NUM_NONREG_ITEMS 4
1332 /* We push at most this many items on the stack. */
1333 /* We used to use (num_regs - 1), which is the number of registers
1334 this regexp will save; but that was changed to 5
1335 to avoid stack overflow for a regexp with lots of parens. */
1336 #define MAX_FAILURE_ITEMS (5 * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1338 /* We actually push this many items. */
1339 #define NUM_FAILURE_ITEMS \
1341 ? 0 : highest_active_reg - lowest_active_reg + 1) \
1345 /* How many items can still be added to the stack without overflowing it. */
1346 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1349 /* Pops what PUSH_FAIL_STACK pushes.
1351 We restore into the parameters, all of which should be lvalues:
1352 STR -- the saved data position.
1353 PAT -- the saved pattern position.
1354 LOW_REG, HIGH_REG -- the highest and lowest active registers.
1355 REGSTART, REGEND -- arrays of string positions.
1356 REG_INFO -- array of information about each subexpression.
1358 Also assumes the variables `fail_stack' and (if debugging), `bufp',
1359 `pend', `string1', `size1', `string2', and `size2'. */
1361 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1363 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
1365 const unsigned char *string_temp; \
1367 assert (!FAIL_STACK_EMPTY ()); \
1369 /* Remove failure points and point to how many regs pushed. */ \
1370 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1371 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1372 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1374 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1376 DEBUG_POP (&failure_id); \
1377 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1379 /* If the saved string location is NULL, it came from an \
1380 on_failure_keep_string_jump opcode, and we want to throw away the \
1381 saved NULL, thus retaining our current position in the string. */ \
1382 string_temp = POP_FAILURE_POINTER (); \
1383 if (string_temp != NULL) \
1384 str = (const char *) string_temp; \
1386 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
1387 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1388 DEBUG_PRINT1 ("'\n"); \
1390 pat = (unsigned char *) POP_FAILURE_POINTER (); \
1391 DEBUG_PRINT2 (" Popping pattern 0x%x:\n", pat); \
1392 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1394 /* Restore register info. */ \
1395 high_reg = (active_reg_t) POP_FAILURE_INT (); \
1396 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
1398 low_reg = (active_reg_t) POP_FAILURE_INT (); \
1399 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
1402 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
1404 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
1406 reg_info[this_reg].word = POP_FAILURE_ELT (); \
1407 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
1409 regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1410 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1412 regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1413 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1417 for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \
1419 reg_info[this_reg].word.integer = 0; \
1420 regend[this_reg] = 0; \
1421 regstart[this_reg] = 0; \
1423 highest_active_reg = high_reg; \
1426 set_regs_matched_done = 0; \
1427 DEBUG_STATEMENT (nfailure_points_popped++); \
1428 } /* POP_FAILURE_POINT */
1432 /* Structure for per-register (a.k.a. per-group) information.
1433 Other register information, such as the
1434 starting and ending positions (which are addresses), and the list of
1435 inner groups (which is a bits list) are maintained in separate
1438 We are making a (strictly speaking) nonportable assumption here: that
1439 the compiler will pack our bit fields into something that fits into
1440 the type of `word', i.e., is something that fits into one item on the
1444 /* Declarations and macros for re_match_2. */
1447 fail_stack_elt_t word;
1449 /* This field is one if this group can match the empty string,
1450 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1451 #define MATCH_NULL_UNSET_VALUE 3
1452 unsigned match_null_string_p:2;
1453 unsigned is_active:1;
1454 unsigned matched_something:1;
1455 unsigned ever_matched_something:1;
1457 } register_info_type;
1459 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1460 #define IS_ACTIVE(R) ((R).bits.is_active)
1461 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1462 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1465 /* Call this when have matched a real character; it sets `matched' flags
1466 for the subexpressions which we are currently inside. Also records
1467 that those subexprs have matched. */
1468 #define SET_REGS_MATCHED() \
1471 if (!set_regs_matched_done) \
1474 set_regs_matched_done = 1; \
1475 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1477 MATCHED_SOMETHING (reg_info[r]) \
1478 = EVER_MATCHED_SOMETHING (reg_info[r]) \
1485 /* Registers are set to a sentinel when they haven't yet matched. */
1486 static char reg_unset_dummy;
1488 #define REG_UNSET_VALUE (®_unset_dummy)
1489 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1491 /* Subroutine declarations and macros for regex_compile. */
1493 static reg_errcode_t regex_compile
1494 _RE_ARGS ((const char *pattern, size_t size, reg_syntax_t syntax,
1495 struct re_pattern_buffer * bufp));
1496 static void store_op1
1497 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg));
1498 static void store_op2
1499 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg1, int arg2));
1500 static void insert_op1
1501 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg, unsigned char *end));
1502 static void insert_op2
1503 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg1, int arg2,
1504 unsigned char *end));
1505 static boolean at_begline_loc_p
1506 _RE_ARGS ((const char *pattern, const char *p, reg_syntax_t syntax));
1507 static boolean at_endline_loc_p
1508 _RE_ARGS ((const char *p, const char *pend, reg_syntax_t syntax));
1509 static reg_errcode_t compile_range
1510 _RE_ARGS ((const char **p_ptr, const char *pend, char *translate,
1511 reg_syntax_t syntax, unsigned char *b));
1513 /* Fetch the next character in the uncompiled pattern---translating it
1514 if necessary. Also cast from a signed character in the constant
1515 string passed to us by the user to an unsigned char that we can use
1516 as an array index (in, e.g., `translate'). */
1518 #define PATFETCH(c) \
1519 do {if (p == pend) return REG_EEND; \
1520 c = (unsigned char) *p++; \
1521 if (translate) c = (unsigned char) translate[c]; \
1525 /* Fetch the next character in the uncompiled pattern, with no
1527 #define PATFETCH_RAW(c) \
1528 do {if (p == pend) return REG_EEND; \
1529 c = (unsigned char) *p++; \
1532 /* Go backwards one character in the pattern. */
1533 #define PATUNFETCH p--
1536 /* If `translate' is non-null, return translate[D], else just D. We
1537 cast the subscript to translate because some data is declared as
1538 `char *', to avoid warnings when a string constant is passed. But
1539 when we use a character as a subscript we must make it unsigned. */
1541 #define TRANSLATE(d) \
1542 (translate ? (char) translate[(unsigned char) (d)] : (d))
1546 /* Macros for outputting the compiled pattern into `buffer'. */
1548 /* If the buffer isn't allocated when it comes in, use this. */
1549 #define INIT_BUF_SIZE 32
1551 /* Make sure we have at least N more bytes of space in buffer. */
1552 #define GET_BUFFER_SPACE(n) \
1553 while ((unsigned long) (b - bufp->buffer + (n)) > bufp->allocated) \
1556 /* Make sure we have one more byte of buffer space and then add C to it. */
1557 #define BUF_PUSH(c) \
1559 GET_BUFFER_SPACE (1); \
1560 *b++ = (unsigned char) (c); \
1564 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1565 #define BUF_PUSH_2(c1, c2) \
1567 GET_BUFFER_SPACE (2); \
1568 *b++ = (unsigned char) (c1); \
1569 *b++ = (unsigned char) (c2); \
1573 /* As with BUF_PUSH_2, except for three bytes. */
1574 #define BUF_PUSH_3(c1, c2, c3) \
1576 GET_BUFFER_SPACE (3); \
1577 *b++ = (unsigned char) (c1); \
1578 *b++ = (unsigned char) (c2); \
1579 *b++ = (unsigned char) (c3); \
1583 /* Store a jump with opcode OP at LOC to location TO. We store a
1584 relative address offset by the three bytes the jump itself occupies. */
1585 #define STORE_JUMP(op, loc, to) \
1586 store_op1 (op, loc, (int) ((to) - (loc) - 3))
1588 /* Likewise, for a two-argument jump. */
1589 #define STORE_JUMP2(op, loc, to, arg) \
1590 store_op2 (op, loc, (int) ((to) - (loc) - 3), arg)
1592 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1593 #define INSERT_JUMP(op, loc, to) \
1594 insert_op1 (op, loc, (int) ((to) - (loc) - 3), b)
1596 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1597 #define INSERT_JUMP2(op, loc, to, arg) \
1598 insert_op2 (op, loc, (int) ((to) - (loc) - 3), arg, b)
1601 /* This is not an arbitrary limit: the arguments which represent offsets
1602 into the pattern are two bytes long. So if 2^16 bytes turns out to
1603 be too small, many things would have to change. */
1604 /* Any other compiler which, like MSC, has allocation limit below 2^16
1605 bytes will have to use approach similar to what was done below for
1606 MSC and drop MAX_BUF_SIZE a bit. Otherwise you may end up
1607 reallocating to 0 bytes. Such thing is not going to work too well.
1608 You have been warned!! */
1609 #if defined(_MSC_VER) && !defined(WIN32)
1610 /* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
1611 The REALLOC define eliminates a flurry of conversion warnings,
1612 but is not required. */
1613 #define MAX_BUF_SIZE 65500L
1614 #define REALLOC(p,s) realloc ((p), (size_t) (s))
1616 #define MAX_BUF_SIZE (1L << 16)
1617 #define REALLOC(p,s) realloc ((p), (s))
1620 /* Extend the buffer by twice its current size via realloc and
1621 reset the pointers that pointed into the old block to point to the
1622 correct places in the new one. If extending the buffer results in it
1623 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1624 #define EXTEND_BUFFER() \
1626 unsigned char *old_buffer = bufp->buffer; \
1627 if (bufp->allocated == MAX_BUF_SIZE) \
1629 bufp->allocated <<= 1; \
1630 if (bufp->allocated > MAX_BUF_SIZE) \
1631 bufp->allocated = MAX_BUF_SIZE; \
1632 bufp->buffer = (unsigned char *) REALLOC (bufp->buffer, bufp->allocated);\
1633 if (bufp->buffer == NULL) \
1634 return REG_ESPACE; \
1635 /* If the buffer moved, move all the pointers into it. */ \
1636 if (old_buffer != bufp->buffer) \
1638 b = (b - old_buffer) + bufp->buffer; \
1639 begalt = (begalt - old_buffer) + bufp->buffer; \
1640 if (fixup_alt_jump) \
1641 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1643 laststart = (laststart - old_buffer) + bufp->buffer; \
1644 if (pending_exact) \
1645 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1650 /* Since we have one byte reserved for the register number argument to
1651 {start,stop}_memory, the maximum number of groups we can report
1652 things about is what fits in that byte. */
1653 #define MAX_REGNUM 255
1655 /* But patterns can have more than `MAX_REGNUM' registers. We just
1656 ignore the excess. */
1657 typedef unsigned regnum_t;
1660 /* Macros for the compile stack. */
1662 /* Since offsets can go either forwards or backwards, this type needs to
1663 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1664 /* int may be not enough when sizeof(int) == 2. */
1665 typedef long pattern_offset_t;
1668 pattern_offset_t begalt_offset;
1669 pattern_offset_t fixup_alt_jump;
1670 pattern_offset_t inner_group_offset;
1671 pattern_offset_t laststart_offset;
1673 } compile_stack_elt_t;
1677 compile_stack_elt_t *stack;
1679 unsigned avail; /* Offset of next open position. */
1680 } compile_stack_type;
1683 #define INIT_COMPILE_STACK_SIZE 32
1685 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1686 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1688 /* The next available element. */
1689 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1692 /* Set the bit for character C in a list. */
1693 #define SET_LIST_BIT(c) \
1694 (b[((unsigned char) (c)) / BYTEWIDTH] \
1695 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1698 /* Get the next unsigned number in the uncompiled pattern. */
1699 #define GET_UNSIGNED_NUMBER(num) \
1703 while (ISDIGIT (c)) \
1707 num = num * 10 + c - '0'; \
1715 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
1716 /* The GNU C library provides support for user-defined character classes
1717 and the functions from ISO C amendement 1. */
1718 # ifdef CHARCLASS_NAME_MAX
1719 # define CHAR_CLASS_MAX_LENGTH CHARCLASS_NAME_MAX
1721 /* This shouldn't happen but some implementation might still have this
1722 problem. Use a reasonable default value. */
1723 # define CHAR_CLASS_MAX_LENGTH 256
1726 # define IS_CHAR_CLASS(string) wctype (string)
1728 # define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1730 # define IS_CHAR_CLASS(string) \
1731 (STREQ (string, "alpha") || STREQ (string, "upper") \
1732 || STREQ (string, "lower") || STREQ (string, "digit") \
1733 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1734 || STREQ (string, "space") || STREQ (string, "print") \
1735 || STREQ (string, "punct") || STREQ (string, "graph") \
1736 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1739 #ifndef MATCH_MAY_ALLOCATE
1741 /* If we cannot allocate large objects within re_match_2_internal,
1742 we make the fail stack and register vectors global.
1743 The fail stack, we grow to the maximum size when a regexp
1745 The register vectors, we adjust in size each time we
1746 compile a regexp, according to the number of registers it needs. */
1748 static fail_stack_type fail_stack;
1750 /* Size with which the following vectors are currently allocated.
1751 That is so we can make them bigger as needed,
1752 but never make them smaller. */
1753 static int regs_allocated_size;
1755 static const char **regstart, **regend;
1756 static const char **old_regstart, **old_regend;
1757 static const char **best_regstart, **best_regend;
1758 static register_info_type *reg_info;
1759 static const char **reg_dummy;
1760 static register_info_type *reg_info_dummy;
1762 /* Make the register vectors big enough for NUM_REGS registers,
1763 but don't make them smaller. */
1765 static regex_grow_registers (num_regs)
1768 if (num_regs > regs_allocated_size) {
1769 RETALLOC_IF (regstart, num_regs, const char *);
1770 RETALLOC_IF (regend, num_regs, const char *);
1771 RETALLOC_IF (old_regstart, num_regs, const char *);
1772 RETALLOC_IF (old_regend, num_regs, const char *);
1773 RETALLOC_IF (best_regstart, num_regs, const char *);
1774 RETALLOC_IF (best_regend, num_regs, const char *);
1776 RETALLOC_IF (reg_info, num_regs, register_info_type);
1777 RETALLOC_IF (reg_dummy, num_regs, const char *);
1779 RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
1781 regs_allocated_size = num_regs;
1785 #endif /* not MATCH_MAY_ALLOCATE */
1787 static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
1791 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1792 Returns one of error codes defined in `regex.h', or zero for success.
1794 Assumes the `allocated' (and perhaps `buffer') and `translate'
1795 fields are set in BUFP on entry.
1797 If it succeeds, results are put in BUFP (if it returns an error, the
1798 contents of BUFP are undefined):
1799 `buffer' is the compiled pattern;
1800 `syntax' is set to SYNTAX;
1801 `used' is set to the length of the compiled pattern;
1802 `fastmap_accurate' is zero;
1803 `re_nsub' is the number of subexpressions in PATTERN;
1804 `not_bol' and `not_eol' are zero;
1806 The `fastmap' and `newline_anchor' fields are neither
1807 examined nor set. */
1809 /* Return, freeing storage we allocated. */
1810 #define FREE_STACK_RETURN(value) \
1811 return (free (compile_stack.stack), value) /* __MEM_CHECKED__ */
1813 #ifndef HAVE_ISCTYPE
1814 static int isctype (char c, int desc)
1840 return ISXDIGIT (c);
1842 return 0; /* false */
1846 static reg_errcode_t regex_compile (pattern, size, syntax, bufp)
1847 const char *pattern;
1849 reg_syntax_t syntax;
1850 struct re_pattern_buffer *bufp;
1852 /* We fetch characters from PATTERN here. Even though PATTERN is
1853 `char *' (i.e., signed), we declare these variables as unsigned, so
1854 they can be reliably used as array indices. */
1855 register unsigned char c, c1;
1857 /* A random temporary spot in PATTERN. */
1860 /* Points to the end of the buffer, where we should append. */
1861 register unsigned char *b;
1863 /* Keeps track of unclosed groups. */
1864 compile_stack_type compile_stack;
1866 /* Points to the current (ending) position in the pattern. */
1867 const char *p = pattern;
1868 const char *pend = pattern + size;
1870 /* How to translate the characters in the pattern. */
1871 RE_TRANSLATE_TYPE translate = bufp->translate;
1873 /* Address of the count-byte of the most recently inserted `exactn'
1874 command. This makes it possible to tell if a new exact-match
1875 character can be added to that command or if the character requires
1876 a new `exactn' command. */
1877 unsigned char *pending_exact = 0;
1879 /* Address of start of the most recently finished expression.
1880 This tells, e.g., postfix * where to find the start of its
1881 operand. Reset at the beginning of groups and alternatives. */
1882 unsigned char *laststart = 0;
1884 /* Address of beginning of regexp, or inside of last group. */
1885 unsigned char *begalt;
1887 /* Place in the uncompiled pattern (i.e., the {) to
1888 which to go back if the interval is invalid. */
1889 const char *beg_interval;
1891 /* Address of the place where a forward jump should go to the end of
1892 the containing expression. Each alternative of an `or' -- except the
1893 last -- ends with a forward jump of this sort. */
1894 unsigned char *fixup_alt_jump = 0;
1896 /* Counts open-groups as they are encountered. Remembered for the
1897 matching close-group on the compile stack, so the same register
1898 number is put in the stop_memory as the start_memory. */
1899 regnum_t regnum = 0;
1902 DEBUG_PRINT1 ("\nCompiling pattern: ");
1904 unsigned debug_count;
1906 for (debug_count = 0; debug_count < size; debug_count++)
1907 putchar (pattern[debug_count]);
1912 /* Initialize the compile stack. */
1913 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1914 if (compile_stack.stack == NULL)
1917 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1918 compile_stack.avail = 0;
1920 /* Initialize the pattern buffer. */
1921 bufp->syntax = syntax;
1922 bufp->fastmap_accurate = 0;
1923 bufp->not_bol = bufp->not_eol = 0;
1925 /* Set `used' to zero, so that if we return an error, the pattern
1926 printer (for debugging) will think there's no pattern. We reset it
1930 /* Always count groups, whether or not bufp->no_sub is set. */
1933 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1934 /* Initialize the syntax table. */
1935 init_syntax_once ();
1938 if (bufp->allocated == 0) {
1939 if (bufp->buffer) { /* If zero allocated, but buffer is non-null, try to realloc
1940 enough space. This loses if buffer's address is bogus, but
1941 that is the user's responsibility. */
1942 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1944 else { /* Caller did not allocate a buffer. Do it for them. */
1945 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1948 FREE_STACK_RETURN (REG_ESPACE);
1950 bufp->allocated = INIT_BUF_SIZE;
1953 begalt = b = bufp->buffer;
1955 /* Loop through the uncompiled pattern until we're at the end. */
1962 if ( /* If at start of pattern, it's an operator. */
1964 /* If context independent, it's an operator. */
1965 || syntax & RE_CONTEXT_INDEP_ANCHORS
1966 /* Otherwise, depends on what's come before. */
1967 || at_begline_loc_p (pattern, p, syntax))
1977 if ( /* If at end of pattern, it's an operator. */
1979 /* If context independent, it's an operator. */
1980 || syntax & RE_CONTEXT_INDEP_ANCHORS
1981 /* Otherwise, depends on what's next. */
1982 || at_endline_loc_p (p, pend, syntax))
1992 if ((syntax & RE_BK_PLUS_QM)
1993 || (syntax & RE_LIMITED_OPS))
1997 /* If there is no previous pattern... */
1999 if (syntax & RE_CONTEXT_INVALID_OPS)
2000 FREE_STACK_RETURN (REG_BADRPT);
2001 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
2006 /* Are we optimizing this jump? */
2007 boolean keep_string_p = false;
2009 /* 1 means zero (many) matches is allowed. */
2010 char zero_times_ok = 0, many_times_ok = 0;
2012 /* If there is a sequence of repetition chars, collapse it
2013 down to just one (the right one). We can't combine
2014 interval operators with these because of, e.g., `a{2}*',
2015 which should only match an even number of `a's. */
2018 zero_times_ok |= c != '+';
2019 many_times_ok |= c != '?';
2027 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')));
2029 else if (syntax & RE_BK_PLUS_QM && c == '\\') {
2031 FREE_STACK_RETURN (REG_EESCAPE);
2034 if (!(c1 == '+' || c1 == '?')) {
2047 /* If we get here, we found another repeat character. */
2050 /* Star, etc. applied to an empty pattern is equivalent
2051 to an empty pattern. */
2055 /* Now we know whether or not zero matches is allowed
2056 and also whether or not two or more matches is allowed. */
2057 if (many_times_ok) { /* More than one repetition is allowed, so put in at the
2058 end a backward relative jump from `b' to before the next
2059 jump we're going to put in below (which jumps from
2060 laststart to after this jump).
2062 But if we are at the `*' in the exact sequence `.*\n',
2063 insert an unconditional jump backwards to the .,
2064 instead of the beginning of the loop. This way we only
2065 push a failure point once, instead of every time
2066 through the loop. */
2067 assert (p - 1 > pattern);
2069 /* Allocate the space for the jump. */
2070 GET_BUFFER_SPACE (3);
2072 /* We know we are not at the first character of the pattern,
2073 because laststart was nonzero. And we've already
2074 incremented `p', by the way, to be the character after
2075 the `*'. Do we have to do something analogous here
2076 for null bytes, because of RE_DOT_NOT_NULL? */
2077 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
2079 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
2080 && !(syntax & RE_DOT_NEWLINE)) { /* We have .*\n. */
2081 STORE_JUMP (jump, b, laststart);
2082 keep_string_p = true;
2085 /* Anything else. */
2086 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
2088 /* We've added more stuff to the buffer. */
2092 /* On failure, jump from laststart to b + 3, which will be the
2093 end of the buffer after this jump is inserted. */
2094 GET_BUFFER_SPACE (3);
2095 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
2096 : on_failure_jump, laststart, b + 3);
2100 if (!zero_times_ok) {
2101 /* At least one repetition is required, so insert a
2102 `dummy_failure_jump' before the initial
2103 `on_failure_jump' instruction of the loop. This
2104 effects a skip over that instruction the first time
2105 we hit that loop. */
2106 GET_BUFFER_SPACE (3);
2107 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
2122 boolean had_char_class = false;
2125 FREE_STACK_RETURN (REG_EBRACK);
2127 /* Ensure that we have enough space to push a charset: the
2128 opcode, the length count, and the bitset; 34 bytes in all. */
2129 GET_BUFFER_SPACE (34);
2133 /* We test `*p == '^' twice, instead of using an if
2134 statement, so we only need one BUF_PUSH. */
2135 BUF_PUSH (*p == '^' ? charset_not : charset);
2139 /* Remember the first position in the bracket expression. */
2142 /* Push the number of bytes in the bitmap. */
2143 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
2145 /* Clear the whole map. */
2146 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
2148 /* charset_not matches newline according to a syntax bit. */
2149 if ((re_opcode_t) b[-2] == charset_not
2150 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
2151 SET_LIST_BIT ('\n');
2153 /* Read in characters and ranges, setting map bits. */
2156 FREE_STACK_RETURN (REG_EBRACK);
2160 /* \ might escape characters inside [...] and [^...]. */
2161 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\') {
2163 FREE_STACK_RETURN (REG_EESCAPE);
2170 /* Could be the end of the bracket expression. If it's
2171 not (i.e., when the bracket expression is `[]' so
2172 far), the ']' character bit gets set way below. */
2173 if (c == ']' && p != p1 + 1)
2176 /* Look ahead to see if it's a range when the last thing
2177 was a character class. */
2178 if (had_char_class && c == '-' && *p != ']')
2179 FREE_STACK_RETURN (REG_ERANGE);
2181 /* Look ahead to see if it's a range when the last thing
2182 was a character: if this is a hyphen not at the
2183 beginning or the end of a list, then it's the range
2185 if (c == '-' && !(p - 2 >= pattern && p[-2] == '[')
2186 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
2189 = compile_range (&p, pend, translate, syntax, b);
2190 if (ret != REG_NOERROR)
2191 FREE_STACK_RETURN (ret);
2194 else if (p[0] == '-' && p[1] != ']') { /* This handles ranges made up of characters only. */
2197 /* Move past the `-'. */
2200 ret = compile_range (&p, pend, translate, syntax, b);
2201 if (ret != REG_NOERROR)
2202 FREE_STACK_RETURN (ret);
2205 /* See if we're at the beginning of a possible character
2208 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':') { /* Leave room for the null. */
2209 char str[CHAR_CLASS_MAX_LENGTH + 1];
2214 /* If pattern is `[[:'. */
2216 FREE_STACK_RETURN (REG_EBRACK);
2220 if (c == ':' || c == ']' || p == pend
2221 || c1 == CHAR_CLASS_MAX_LENGTH)
2227 /* If isn't a word bracketed by `[:' and:`]':
2228 undo the ending character, the letters, and leave
2229 the leading `:' and `[' (but set bits for them). */
2230 if (c == ':' && *p == ']') {
2231 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
2232 boolean is_lower = STREQ (str, "lower");
2233 boolean is_upper = STREQ (str, "upper");
2239 FREE_STACK_RETURN (REG_ECTYPE);
2241 /* Throw away the ] at the end of the character
2246 FREE_STACK_RETURN (REG_EBRACK);
2248 for (ch = 0; ch < 1 << BYTEWIDTH; ++ch) {
2249 if (isctype (ch, wt))
2252 if (translate && (is_upper || is_lower)
2253 && (ISUPPER (ch) || ISLOWER (ch)))
2257 had_char_class = true;
2260 boolean is_alnum = STREQ (str, "alnum");
2261 boolean is_alpha = STREQ (str, "alpha");
2262 boolean is_blank = STREQ (str, "blank");
2263 boolean is_cntrl = STREQ (str, "cntrl");
2264 boolean is_digit = STREQ (str, "digit");
2265 boolean is_graph = STREQ (str, "graph");
2266 boolean is_lower = STREQ (str, "lower");
2267 boolean is_print = STREQ (str, "print");
2268 boolean is_punct = STREQ (str, "punct");
2269 boolean is_space = STREQ (str, "space");
2270 boolean is_upper = STREQ (str, "upper");
2271 boolean is_xdigit = STREQ (str, "xdigit");
2273 if (!IS_CHAR_CLASS (str))
2274 FREE_STACK_RETURN (REG_ECTYPE);
2276 /* Throw away the ] at the end of the character
2281 FREE_STACK_RETURN (REG_EBRACK);
2283 for (ch = 0; ch < 1 << BYTEWIDTH; ch++) {
2284 /* This was split into 3 if's to
2285 avoid an arbitrary limit in some compiler. */
2286 if ((is_alnum && ISALNUM (ch))
2287 || (is_alpha && ISALPHA (ch))
2288 || (is_blank && ISBLANK (ch))
2289 || (is_cntrl && ISCNTRL (ch)))
2291 if ((is_digit && ISDIGIT (ch))
2292 || (is_graph && ISGRAPH (ch))
2293 || (is_lower && ISLOWER (ch))
2294 || (is_print && ISPRINT (ch)))
2296 if ((is_punct && ISPUNCT (ch))
2297 || (is_space && ISSPACE (ch))
2298 || (is_upper && ISUPPER (ch))
2299 || (is_xdigit && ISXDIGIT (ch)))
2301 if (translate && (is_upper || is_lower)
2302 && (ISUPPER (ch) || ISLOWER (ch)))
2305 had_char_class = true;
2306 #endif /* libc || wctype.h */
2314 had_char_class = false;
2318 had_char_class = false;
2323 /* Discard any (non)matching list bytes that are all 0 at the
2324 end of the map. Decrease the map-length byte too. */
2325 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
2333 if (syntax & RE_NO_BK_PARENS)
2340 if (syntax & RE_NO_BK_PARENS)
2347 if (syntax & RE_NEWLINE_ALT)
2354 if (syntax & RE_NO_BK_VBAR)
2361 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
2362 goto handle_interval;
2369 FREE_STACK_RETURN (REG_EESCAPE);
2371 /* Do not translate the character after the \, so that we can
2372 distinguish, e.g., \B from \b, even if we normally would
2373 translate, e.g., B to b. */
2378 if (syntax & RE_NO_BK_PARENS)
2379 goto normal_backslash;
2385 if (COMPILE_STACK_FULL) {
2386 RETALLOC (compile_stack.stack, compile_stack.size << 1,
2387 compile_stack_elt_t);
2388 if (compile_stack.stack == NULL)
2391 compile_stack.size <<= 1;
2394 /* These are the values to restore when we hit end of this
2395 group. They are all relative offsets, so that if the
2396 whole pattern moves because of realloc, they will still
2398 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2399 COMPILE_STACK_TOP.fixup_alt_jump
2400 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2401 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2402 COMPILE_STACK_TOP.regnum = regnum;
2404 /* We will eventually replace the 0 with the number of
2405 groups inner to this one. But do not push a
2406 start_memory for groups beyond the last one we can
2407 represent in the compiled pattern. */
2408 if (regnum <= MAX_REGNUM) {
2409 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2410 BUF_PUSH_3 (start_memory, regnum, 0);
2413 compile_stack.avail++;
2418 /* If we've reached MAX_REGNUM groups, then this open
2419 won't actually generate any code, so we'll have to
2420 clear pending_exact explicitly. */
2426 if (syntax & RE_NO_BK_PARENS)
2427 goto normal_backslash;
2429 if (COMPILE_STACK_EMPTY)
2430 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2431 goto normal_backslash;
2433 FREE_STACK_RETURN (REG_ERPAREN);
2436 if (fixup_alt_jump) { /* Push a dummy failure point at the end of the
2437 alternative for a possible future
2438 `pop_failure_jump' to pop. See comments at
2439 `push_dummy_failure' in `re_match_2'. */
2440 BUF_PUSH (push_dummy_failure);
2442 /* We allocated space for this jump when we assigned
2443 to `fixup_alt_jump', in the `handle_alt' case below. */
2444 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2447 /* See similar code for backslashed left paren above. */
2448 if (COMPILE_STACK_EMPTY)
2449 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2452 FREE_STACK_RETURN (REG_ERPAREN);
2454 /* Since we just checked for an empty stack above, this
2455 ``can't happen''. */
2456 assert (compile_stack.avail != 0);
2458 /* We don't just want to restore into `regnum', because
2459 later groups should continue to be numbered higher,
2460 as in `(ab)c(de)' -- the second group is #2. */
2461 regnum_t this_group_regnum;
2463 compile_stack.avail--;
2464 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2466 = COMPILE_STACK_TOP.fixup_alt_jump
2467 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1 : 0;
2468 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2469 this_group_regnum = COMPILE_STACK_TOP.regnum;
2470 /* If we've reached MAX_REGNUM groups, then this open
2471 won't actually generate any code, so we'll have to
2472 clear pending_exact explicitly. */
2475 /* We're at the end of the group, so now we know how many
2476 groups were inside this one. */
2477 if (this_group_regnum <= MAX_REGNUM) {
2478 unsigned char *inner_group_loc
2479 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2481 *inner_group_loc = regnum - this_group_regnum;
2482 BUF_PUSH_3 (stop_memory, this_group_regnum,
2483 regnum - this_group_regnum);
2489 case '|': /* `\|'. */
2490 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
2491 goto normal_backslash;
2493 if (syntax & RE_LIMITED_OPS)
2496 /* Insert before the previous alternative a jump which
2497 jumps to this alternative if the former fails. */
2498 GET_BUFFER_SPACE (3);
2499 INSERT_JUMP (on_failure_jump, begalt, b + 6);
2503 /* The alternative before this one has a jump after it
2504 which gets executed if it gets matched. Adjust that
2505 jump so it will jump to this alternative's analogous
2506 jump (put in below, which in turn will jump to the next
2507 (if any) alternative's such jump, etc.). The last such
2508 jump jumps to the correct final destination. A picture:
2514 If we are at `b', then fixup_alt_jump right now points to a
2515 three-byte space after `a'. We'll put in the jump, set
2516 fixup_alt_jump to right after `b', and leave behind three
2517 bytes which we'll fill in when we get to after `c'. */
2520 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2522 /* Mark and leave space for a jump after this alternative,
2523 to be filled in later either by next alternative or
2524 when know we're at the end of a series of alternatives. */
2526 GET_BUFFER_SPACE (3);
2535 /* If \{ is a literal. */
2536 if (!(syntax & RE_INTERVALS)
2537 /* If we're at `\{' and it's not the open-interval
2539 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2540 || (p - 2 == pattern && p == pend))
2541 goto normal_backslash;
2545 /* If got here, then the syntax allows intervals. */
2547 /* At least (most) this many matches must be made. */
2548 int lower_bound = -1, upper_bound = -1;
2550 beg_interval = p - 1;
2553 if (syntax & RE_NO_BK_BRACES)
2554 goto unfetch_interval;
2556 FREE_STACK_RETURN (REG_EBRACE);
2559 GET_UNSIGNED_NUMBER (lower_bound);
2562 GET_UNSIGNED_NUMBER (upper_bound);
2563 if (upper_bound < 0)
2564 upper_bound = RE_DUP_MAX;
2567 /* Interval such as `{1}' => match exactly once. */
2568 upper_bound = lower_bound;
2570 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
2571 || lower_bound > upper_bound) {
2572 if (syntax & RE_NO_BK_BRACES)
2573 goto unfetch_interval;
2575 FREE_STACK_RETURN (REG_BADBR);
2578 if (!(syntax & RE_NO_BK_BRACES)) {
2580 FREE_STACK_RETURN (REG_EBRACE);
2586 if (syntax & RE_NO_BK_BRACES)
2587 goto unfetch_interval;
2589 FREE_STACK_RETURN (REG_BADBR);
2592 /* We just parsed a valid interval. */
2594 /* If it's invalid to have no preceding re. */
2596 if (syntax & RE_CONTEXT_INVALID_OPS)
2597 FREE_STACK_RETURN (REG_BADRPT);
2598 else if (syntax & RE_CONTEXT_INDEP_OPS)
2601 goto unfetch_interval;
2604 /* If the upper bound is zero, don't want to succeed at
2605 all; jump from `laststart' to `b + 3', which will be
2606 the end of the buffer after we insert the jump. */
2607 if (upper_bound == 0) {
2608 GET_BUFFER_SPACE (3);
2609 INSERT_JUMP (jump, laststart, b + 3);
2613 /* Otherwise, we have a nontrivial interval. When
2614 we're all done, the pattern will look like:
2615 set_number_at <jump count> <upper bound>
2616 set_number_at <succeed_n count> <lower bound>
2617 succeed_n <after jump addr> <succeed_n count>
2619 jump_n <succeed_n addr> <jump count>
2620 (The upper bound and `jump_n' are omitted if
2621 `upper_bound' is 1, though.) */
2622 else { /* If the upper bound is > 1, we need to insert
2623 more at the end of the loop. */
2624 unsigned nbytes = 10 + (upper_bound > 1) * 10;
2626 GET_BUFFER_SPACE (nbytes);
2628 /* Initialize lower bound of the `succeed_n', even
2629 though it will be set during matching by its
2630 attendant `set_number_at' (inserted next),
2631 because `re_compile_fastmap' needs to know.
2632 Jump to the `jump_n' we might insert below. */
2633 INSERT_JUMP2 (succeed_n, laststart,
2634 b + 5 + (upper_bound > 1) * 5, lower_bound);
2637 /* Code to initialize the lower bound. Insert
2638 before the `succeed_n'. The `5' is the last two
2639 bytes of this `set_number_at', plus 3 bytes of
2640 the following `succeed_n'. */
2641 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2644 if (upper_bound > 1) { /* More than one repetition is allowed, so
2645 append a backward jump to the `succeed_n'
2646 that starts this interval.
2648 When we've reached this during matching,
2649 we'll have matched the interval once, so
2650 jump back only `upper_bound - 1' times. */
2651 STORE_JUMP2 (jump_n, b, laststart + 5, upper_bound - 1);
2654 /* The location we want to set is the second
2655 parameter of the `jump_n'; that is `b-2' as
2656 an absolute address. `laststart' will be
2657 the `set_number_at' we're about to insert;
2658 `laststart+3' the number to set, the source
2659 for the relative address. But we are
2660 inserting into the middle of the pattern --
2661 so everything is getting moved up by 5.
2662 Conclusion: (b - 2) - (laststart + 3) + 5,
2663 i.e., b - laststart.
2665 We insert this at the beginning of the loop
2666 so that if we fail during matching, we'll
2667 reinitialize the bounds. */
2668 insert_op2 (set_number_at, laststart, b - laststart,
2669 upper_bound - 1, b);
2674 beg_interval = NULL;
2679 /* If an invalid interval, match the characters as literals. */
2680 assert (beg_interval);
2682 beg_interval = NULL;
2684 /* normal_char and normal_backslash need `c'. */
2687 if (!(syntax & RE_NO_BK_BRACES)) {
2688 if (p > pattern && p[-1] == '\\')
2689 goto normal_backslash;
2694 /* There is no way to specify the before_dot and after_dot
2695 operators. rms says this is ok. --karl */
2703 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2709 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2715 if (re_syntax_options & RE_NO_GNU_OPS)
2718 BUF_PUSH (wordchar);
2723 if (re_syntax_options & RE_NO_GNU_OPS)
2726 BUF_PUSH (notwordchar);
2731 if (re_syntax_options & RE_NO_GNU_OPS)
2737 if (re_syntax_options & RE_NO_GNU_OPS)
2743 if (re_syntax_options & RE_NO_GNU_OPS)
2745 BUF_PUSH (wordbound);
2749 if (re_syntax_options & RE_NO_GNU_OPS)
2751 BUF_PUSH (notwordbound);
2755 if (re_syntax_options & RE_NO_GNU_OPS)
2761 if (re_syntax_options & RE_NO_GNU_OPS)
2775 if (syntax & RE_NO_BK_REFS)
2781 FREE_STACK_RETURN (REG_ESUBREG);
2783 /* Can't back reference to a subexpression if inside of it. */
2784 if (group_in_compile_stack (compile_stack, (regnum_t) c1))
2788 BUF_PUSH_2 (duplicate, c1);
2794 if (syntax & RE_BK_PLUS_QM)
2797 goto normal_backslash;
2801 /* You might think it would be useful for \ to mean
2802 not to translate; but if we don't translate it
2803 it will never match anything. */
2811 /* Expects the character in `c'. */
2813 /* If no exactn currently being built. */
2815 /* If last exactn not at current position. */
2816 || pending_exact + *pending_exact + 1 != b
2817 /* We have only one byte following the exactn for the count. */
2818 || *pending_exact == (1 << BYTEWIDTH) - 1
2819 /* If followed by a repetition operator. */
2820 || *p == '*' || *p == '^' || ((syntax & RE_BK_PLUS_QM)
2821 ? *p == '\\' && (p[1] == '+'
2823 : (*p == '+' || *p == '?'))
2824 || ((syntax & RE_INTERVALS)
2825 && ((syntax & RE_NO_BK_BRACES)
2826 ? *p == '{' : (p[0] == '\\' && p[1] == '{')))) {
2827 /* Start building a new exactn. */
2831 BUF_PUSH_2 (exactn, 0);
2832 pending_exact = b - 1;
2839 } /* while p != pend */
2842 /* Through the pattern now. */
2845 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2847 if (!COMPILE_STACK_EMPTY)
2848 FREE_STACK_RETURN (REG_EPAREN);
2850 /* If we don't want backtracking, force success
2851 the first time we reach the end of the compiled pattern. */
2852 if (syntax & RE_NO_POSIX_BACKTRACKING)
2855 free (compile_stack.stack); /* __MEM_CHECKED__ */
2857 /* We have succeeded; set the length of the buffer. */
2858 bufp->used = b - bufp->buffer;
2862 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2863 print_compiled_pattern (bufp);
2867 #ifndef MATCH_MAY_ALLOCATE
2868 /* Initialize the failure stack to the largest possible stack. This
2869 isn't necessary unless we're trying to avoid calling alloca in
2870 the search and match routines. */
2872 int num_regs = bufp->re_nsub + 1;
2874 /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2875 is strictly greater than re_max_failures, the largest possible stack
2876 is 2 * re_max_failures failure points. */
2877 if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS)) {
2878 fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2881 if (!fail_stack.stack)
2883 = (fail_stack_elt_t *) xmalloc (fail_stack.size
2884 * sizeof (fail_stack_elt_t));
2887 = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
2889 * sizeof (fail_stack_elt_t)));
2890 #else /* not emacs */
2891 if (!fail_stack.stack)
2892 fail_stack.stack = (fail_stack_elt_t *) malloc (fail_stack.size /* __MEM_CHECKED__ */
2895 (fail_stack_elt_t));
2897 fail_stack.stack = (fail_stack_elt_t *) realloc (fail_stack.stack, /* __MEM_CHECKED__ */
2901 (fail_stack_elt_t)));
2902 #endif /* not emacs */
2905 regex_grow_registers (num_regs);
2907 #endif /* not MATCH_MAY_ALLOCATE */
2910 } /* regex_compile */
2912 /* Subroutines for `regex_compile'. */
2914 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2916 static void store_op1 (op, loc, arg)
2921 *loc = (unsigned char) op;
2922 STORE_NUMBER (loc + 1, arg);
2926 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2928 static void store_op2 (op, loc, arg1, arg2)
2933 *loc = (unsigned char) op;
2934 STORE_NUMBER (loc + 1, arg1);
2935 STORE_NUMBER (loc + 3, arg2);
2939 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2940 for OP followed by two-byte integer parameter ARG. */
2942 static void insert_op1 (op, loc, arg, end)
2948 register unsigned char *pfrom = end;
2949 register unsigned char *pto = end + 3;
2951 while (pfrom != loc)
2954 store_op1 (op, loc, arg);
2958 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2960 static void insert_op2 (op, loc, arg1, arg2, end)
2966 register unsigned char *pfrom = end;
2967 register unsigned char *pto = end + 5;
2969 while (pfrom != loc)
2972 store_op2 (op, loc, arg1, arg2);
2976 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2977 after an alternative or a begin-subexpression. We assume there is at
2978 least one character before the ^. */
2980 static boolean at_begline_loc_p (pattern, p, syntax)
2981 const char *pattern, *p;
2982 reg_syntax_t syntax;
2984 const char *prev = p - 2;
2985 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2988 /* After a subexpression? */
2989 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2990 /* After an alternative? */
2991 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2995 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2996 at least one character after the $, i.e., `P < PEND'. */
2998 static boolean at_endline_loc_p (p, pend, syntax)
2999 const char *p, *pend;
3000 reg_syntax_t syntax;
3002 const char *next = p;
3003 boolean next_backslash = *next == '\\';
3004 const char *next_next = p + 1 < pend ? p + 1 : 0;
3007 /* Before a subexpression? */
3008 (syntax & RE_NO_BK_PARENS ? *next == ')'
3009 : next_backslash && next_next && *next_next == ')')
3010 /* Before an alternative? */
3011 || (syntax & RE_NO_BK_VBAR ? *next == '|'
3012 : next_backslash && next_next && *next_next == '|');
3016 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
3017 false if it's not. */
3019 static boolean group_in_compile_stack (compile_stack, regnum)
3020 compile_stack_type compile_stack;
3025 for (this_element = compile_stack.avail - 1;
3026 this_element >= 0; this_element--)
3027 if (compile_stack.stack[this_element].regnum == regnum)
3034 /* Read the ending character of a range (in a bracket expression) from the
3035 uncompiled pattern *P_PTR (which ends at PEND). We assume the
3036 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
3037 Then we set the translation of all bits between the starting and
3038 ending characters (inclusive) in the compiled pattern B.
3040 Return an error code.
3042 We use these short variable names so we can use the same macros as
3043 `regex_compile' itself. */
3045 static reg_errcode_t compile_range (p_ptr, pend, translate, syntax, b)
3046 const char **p_ptr, *pend;
3047 RE_TRANSLATE_TYPE translate;
3048 reg_syntax_t syntax;
3053 const char *p = *p_ptr;
3054 unsigned int range_start, range_end;
3059 /* Even though the pattern is a signed `char *', we need to fetch
3060 with unsigned char *'s; if the high bit of the pattern character
3061 is set, the range endpoints will be negative if we fetch using a
3064 We also want to fetch the endpoints without translating them; the
3065 appropriate translation is done in the bit-setting loop below. */
3066 /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *. */
3067 range_start = ((const unsigned char *) p)[-2];
3068 range_end = ((const unsigned char *) p)[0];
3070 /* Have to increment the pointer into the pattern string, so the
3071 caller isn't still at the ending character. */
3074 /* If the start is after the end, the range is empty. */
3075 if (range_start > range_end)
3076 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
3078 /* Here we see why `this_char' has to be larger than an `unsigned
3079 char' -- the range is inclusive, so if `range_end' == 0xff
3080 (assuming 8-bit characters), we would otherwise go into an infinite
3081 loop, since all characters <= 0xff. */
3082 for (this_char = range_start; this_char <= range_end; this_char++) {
3083 SET_LIST_BIT (TRANSLATE (this_char));
3089 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
3090 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
3091 characters can start a string that matches the pattern. This fastmap
3092 is used by re_search to skip quickly over impossible starting points.
3094 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
3095 area as BUFP->fastmap.
3097 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
3100 Returns 0 if we succeed, -2 if an internal error. */
3102 int re_compile_fastmap (bufp)
3103 struct re_pattern_buffer *bufp;
3107 #ifdef MATCH_MAY_ALLOCATE
3108 fail_stack_type fail_stack;
3110 #ifndef REGEX_MALLOC
3113 /* We don't push any register information onto the failure stack. */
3114 unsigned num_regs = 0;
3116 register char *fastmap = bufp->fastmap;
3117 unsigned char *pattern = bufp->buffer;
3118 unsigned char *p = pattern;
3119 register unsigned char *pend = pattern + bufp->used;
3122 /* This holds the pointer to the failure stack, when
3123 it is allocated relocatably. */
3124 fail_stack_elt_t *failure_stack_ptr;
3127 /* Assume that each path through the pattern can be null until
3128 proven otherwise. We set this false at the bottom of switch
3129 statement, to which we get only if a particular path doesn't
3130 match the empty string. */
3131 boolean path_can_be_null = true;
3133 /* We aren't doing a `succeed_n' to begin with. */
3134 boolean succeed_n_p = false;
3136 assert (fastmap != NULL && p != NULL);
3139 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
3140 bufp->fastmap_accurate = 1; /* It will be when we're done. */
3141 bufp->can_be_null = 0;
3144 if (p == pend || *p == succeed) {
3145 /* We have reached the (effective) end of pattern. */
3146 if (!FAIL_STACK_EMPTY ()) {
3147 bufp->can_be_null |= path_can_be_null;
3149 /* Reset for next path. */
3150 path_can_be_null = true;
3152 p = fail_stack.stack[--fail_stack.avail].pointer;
3160 /* We should never be about to go beyond the end of the pattern. */
3163 switch (SWITCH_ENUM_CAST ((re_opcode_t) * p++)) {
3165 /* I guess the idea here is to simply not bother with a fastmap
3166 if a backreference is used, since it's too hard to figure out
3167 the fastmap for the corresponding group. Setting
3168 `can_be_null' stops `re_search_2' from using the fastmap, so
3169 that is all we do. */
3171 bufp->can_be_null = 1;
3175 /* Following are the cases which match a character. These end
3184 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
3185 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
3191 /* Chars beyond end of map must be allowed. */
3192 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
3195 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
3196 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
3202 for (j = 0; j < (1 << BYTEWIDTH); j++)
3203 if (SYNTAX (j) == Sword)
3209 for (j = 0; j < (1 << BYTEWIDTH); j++)
3210 if (SYNTAX (j) != Sword)
3217 int fastmap_newline = fastmap['\n'];
3219 /* `.' matches anything ... */
3220 for (j = 0; j < (1 << BYTEWIDTH); j++)
3223 /* ... except perhaps newline. */
3224 if (!(bufp->syntax & RE_DOT_NEWLINE))
3225 fastmap['\n'] = fastmap_newline;
3227 /* Return if we have already set `can_be_null'; if we have,
3228 then the fastmap is irrelevant. Something's wrong here. */
3229 else if (bufp->can_be_null)
3232 /* Otherwise, have to check alternative paths. */
3239 for (j = 0; j < (1 << BYTEWIDTH); j++)
3240 if (SYNTAX (j) == (enum syntaxcode) k)
3247 for (j = 0; j < (1 << BYTEWIDTH); j++)
3248 if (SYNTAX (j) != (enum syntaxcode) k)
3253 /* All cases after this match the empty string. These end with
3273 case push_dummy_failure:
3278 case pop_failure_jump:
3279 case maybe_pop_jump:
3282 case dummy_failure_jump:
3283 EXTRACT_NUMBER_AND_INCR (j, p);
3288 /* Jump backward implies we just went through the body of a
3289 loop and matched nothing. Opcode jumped to should be
3290 `on_failure_jump' or `succeed_n'. Just treat it like an
3291 ordinary jump. For a * loop, it has pushed its failure
3292 point already; if so, discard that as redundant. */
3293 if ((re_opcode_t) * p != on_failure_jump
3294 && (re_opcode_t) * p != succeed_n)
3298 EXTRACT_NUMBER_AND_INCR (j, p);
3301 /* If what's on the stack is where we are now, pop it. */
3302 if (!FAIL_STACK_EMPTY ()
3303 && fail_stack.stack[fail_stack.avail - 1].pointer == p)
3309 case on_failure_jump:
3310 case on_failure_keep_string_jump:
3311 handle_on_failure_jump:
3312 EXTRACT_NUMBER_AND_INCR (j, p);
3314 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
3315 end of the pattern. We don't want to push such a point,
3316 since when we restore it above, entering the switch will
3317 increment `p' past the end of the pattern. We don't need
3318 to push such a point since we obviously won't find any more
3319 fastmap entries beyond `pend'. Such a pattern can match
3320 the null string, though. */
3322 if (!PUSH_PATTERN_OP (p + j, fail_stack)) {
3323 RESET_FAIL_STACK ();
3328 bufp->can_be_null = 1;
3331 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
3332 succeed_n_p = false;
3339 /* Get to the number of times to succeed. */
3342 /* Increment p past the n for when k != 0. */
3343 EXTRACT_NUMBER_AND_INCR (k, p);
3346 succeed_n_p = true; /* Spaghetti code alert. */
3347 goto handle_on_failure_jump;
3364 abort (); /* We have listed all the cases. */
3367 /* Getting here means we have found the possible starting
3368 characters for one path of the pattern -- and that the empty
3369 string does not match. We need not follow this path further.
3370 Instead, look at the next alternative (remembered on the
3371 stack), or quit if no more. The test at the top of the loop
3372 does these things. */
3373 path_can_be_null = false;
3377 /* Set `can_be_null' for the last path (also the first path, if the
3378 pattern is empty). */
3379 bufp->can_be_null |= path_can_be_null;
3382 RESET_FAIL_STACK ();
3384 } /* re_compile_fastmap */
3386 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
3387 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
3388 this memory for recording register information. STARTS and ENDS
3389 must be allocated using the malloc library routine, and must each
3390 be at least NUM_REGS * sizeof (regoff_t) bytes long.
3392 If NUM_REGS == 0, then subsequent matches should allocate their own
3395 Unless this function is called, the first search or match using
3396 PATTERN_BUFFER will allocate its own register data, without
3397 freeing the old data. */
3399 void re_set_registers (bufp, regs, num_regs, starts, ends)
3400 struct re_pattern_buffer *bufp;
3401 struct re_registers *regs;
3403 regoff_t *starts, *ends;
3406 bufp->regs_allocated = REGS_REALLOCATE;
3407 regs->num_regs = num_regs;
3408 regs->start = starts;
3412 bufp->regs_allocated = REGS_UNALLOCATED;
3414 regs->start = regs->end = (regoff_t *) 0;
3418 /* Searching routines. */
3420 /* Like re_search_2, below, but only one string is specified, and
3421 doesn't let you say where to stop matching. */
3423 int re_search (bufp, string, size, startpos, range, regs)
3424 struct re_pattern_buffer *bufp;
3426 int size, startpos, range;
3427 struct re_registers *regs;
3429 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3434 /* Using the compiled pattern in BUFP->buffer, first tries to match the
3435 virtual concatenation of STRING1 and STRING2, starting first at index
3436 STARTPOS, then at STARTPOS + 1, and so on.
3438 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3440 RANGE is how far to scan while trying to match. RANGE = 0 means try
3441 only at STARTPOS; in general, the last start tried is STARTPOS +
3444 In REGS, return the indices of the virtual concatenation of STRING1
3445 and STRING2 that matched the entire BUFP->buffer and its contained
3448 Do not consider matching one past the index STOP in the virtual
3449 concatenation of STRING1 and STRING2.
3451 We return either the position in the strings at which the match was
3452 found, -1 if no match, or -2 if error (such as failure
3456 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs,
3458 struct re_pattern_buffer *bufp;
3459 const char *string1, *string2;
3463 struct re_registers *regs;
3467 register char *fastmap = bufp->fastmap;
3468 register RE_TRANSLATE_TYPE translate = bufp->translate;
3469 int total_size = size1 + size2;
3470 int endpos = startpos + range;
3472 /* Check for out-of-range STARTPOS. */
3473 if (startpos < 0 || startpos > total_size)
3476 /* Fix up RANGE if it might eventually take us outside
3477 the virtual concatenation of STRING1 and STRING2.
3478 Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE. */
3480 range = 0 - startpos;
3481 else if (endpos > total_size)
3482 range = total_size - startpos;
3484 /* If the search isn't to be a backwards one, don't waste time in a
3485 search for a pattern that must be anchored. */
3486 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0) {
3494 /* In a forward search for something that starts with \=.
3495 don't keep searching past point. */
3496 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0) {
3497 range = PT - startpos;
3503 /* Update the fastmap now if not correct already. */
3504 if (fastmap && !bufp->fastmap_accurate)
3505 if (re_compile_fastmap (bufp) == -2)
3508 /* Loop through the string, looking for a place to start matching. */
3510 /* If a fastmap is supplied, skip quickly over characters that
3511 cannot be the start of a match. If the pattern can match the
3512 null string, however, we don't need to skip characters; we want
3513 the first null string. */
3514 if (fastmap && startpos < total_size && !bufp->can_be_null) {
3515 if (range > 0) { /* Searching forwards. */
3516 register const char *d;
3517 register int lim = 0;
3520 if (startpos < size1 && startpos + range >= size1)
3521 lim = range - (size1 - startpos);
3523 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3525 /* Written out as an if-else to avoid testing `translate'
3528 while (range > lim && !fastmap[(unsigned char)
3529 translate[(unsigned char) *d++]])
3532 while (range > lim && !fastmap[(unsigned char) *d++])
3535 startpos += irange - range;
3537 else { /* Searching backwards. */
3539 register char c = (size1 == 0 || startpos >= size1
3540 ? string2[startpos - size1]
3541 : string1[startpos]);
3543 if (!fastmap[(unsigned char) TRANSLATE (c)])
3548 /* If can't match the null string, and that's all we have left, fail. */
3549 if (range >= 0 && startpos == total_size && fastmap && !bufp->can_be_null)
3552 val = re_match_2_internal (bufp, string1, size1, string2, size2,
3553 startpos, regs, stop);
3554 #ifndef REGEX_MALLOC
3569 else if (range > 0) {
3581 /* This converts PTR, a pointer into one of the search strings `string1'
3582 and `string2' into an offset from the beginning of that string. */
3583 #define POINTER_TO_OFFSET(ptr) \
3584 (FIRST_STRING_P (ptr) \
3585 ? ((regoff_t) ((ptr) - string1)) \
3586 : ((regoff_t) ((ptr) - string2 + size1)))
3588 /* Macros for dealing with the split strings in re_match_2. */
3590 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3592 /* Call before fetching a character with *d. This switches over to
3593 string2 if necessary. */
3594 #define PREFETCH() \
3597 /* End of string2 => fail. */ \
3598 if (dend == end_match_2) \
3600 /* End of string1 => advance to string2. */ \
3602 dend = end_match_2; \
3606 /* Test if at very beginning or at very end of the virtual concatenation
3607 of `string1' and `string2'. If only one string, it's `string2'. */
3608 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3609 #define AT_STRINGS_END(d) ((d) == end2)
3612 /* Test if D points to a character which is word-constituent. We have
3613 two special cases to check for: if past the end of string1, look at
3614 the first character in string2; and if before the beginning of
3615 string2, look at the last character in string1. */
3616 #define WORDCHAR_P(d) \
3617 (SYNTAX ((d) == end1 ? *string2 \
3618 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3621 /* Disabled due to a compiler bug -- see comment at case wordbound */
3623 /* Test if the character before D and the one at D differ with respect
3624 to being word-constituent. */
3625 #define AT_WORD_BOUNDARY(d) \
3626 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3627 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3630 /* Free everything we malloc. */
3631 #ifdef MATCH_MAY_ALLOCATE
3632 #define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
3633 #define FREE_VARIABLES() \
3635 REGEX_FREE_STACK (fail_stack.stack); \
3636 FREE_VAR (regstart); \
3637 FREE_VAR (regend); \
3638 FREE_VAR (old_regstart); \
3639 FREE_VAR (old_regend); \
3640 FREE_VAR (best_regstart); \
3641 FREE_VAR (best_regend); \
3642 FREE_VAR (reg_info); \
3643 FREE_VAR (reg_dummy); \
3644 FREE_VAR (reg_info_dummy); \
3647 #define FREE_VARIABLES() ((void)0) /* Do nothing! But inhibit gcc warning. */
3648 #endif /* not MATCH_MAY_ALLOCATE */
3650 /* These values must meet several constraints. They must not be valid
3651 register values; since we have a limit of 255 registers (because
3652 we use only one byte in the pattern for the register number), we can
3653 use numbers larger than 255. They must differ by 1, because of
3654 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3655 be larger than the value for the highest register, so we do not try
3656 to actually save any registers when none are active. */
3657 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3658 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3660 /* Matching routines. */
3662 #ifndef emacs /* Emacs never uses this. */
3663 /* re_match is like re_match_2 except it takes only a single string. */
3665 int re_match (bufp, string, size, pos, regs)
3666 struct re_pattern_buffer *bufp;
3669 struct re_registers *regs;
3671 int result = re_match_2_internal (bufp, NULL, 0, string, size,
3674 #ifndef REGEX_MALLOC
3681 #endif /* not emacs */
3683 static boolean group_match_null_string_p _RE_ARGS ((unsigned char **p,
3685 register_info_type *
3687 static boolean alt_match_null_string_p
3688 _RE_ARGS ((unsigned char *p, unsigned char *end,
3689 register_info_type * reg_info));
3690 static boolean common_op_match_null_string_p
3691 _RE_ARGS ((unsigned char **p, unsigned char *end,
3692 register_info_type * reg_info));
3693 static int bcmp_translate
3694 _RE_ARGS ((const char *s1, const char *s2, int len, char *translate));
3696 /* re_match_2 matches the compiled pattern in BUFP against the
3697 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3698 and SIZE2, respectively). We start matching at POS, and stop
3701 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3702 store offsets for the substring each group matched in REGS. See the
3703 documentation for exactly how many groups we fill.
3705 We return -1 if no match, -2 if an internal error (such as the
3706 failure stack overflowing). Otherwise, we return the length of the
3707 matched substring. */
3709 int re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3710 struct re_pattern_buffer *bufp;
3711 const char *string1, *string2;
3714 struct re_registers *regs;
3717 int result = re_match_2_internal (bufp, string1, size1, string2, size2,
3720 #ifndef REGEX_MALLOC
3728 /* This is a separate function so that we can force an alloca cleanup
3731 re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
3732 struct re_pattern_buffer *bufp;
3733 const char *string1, *string2;
3736 struct re_registers *regs;
3739 /* General temporaries. */
3743 /* Just past the end of the corresponding string. */
3744 const char *end1, *end2;
3746 /* Pointers into string1 and string2, just past the last characters in
3747 each to consider matching. */
3748 const char *end_match_1, *end_match_2;
3750 /* Where we are in the data, and the end of the current string. */
3751 const char *d, *dend;
3753 /* Where we are in the pattern, and the end of the pattern. */
3754 unsigned char *p = bufp->buffer;
3755 register unsigned char *pend = p + bufp->used;
3757 /* Mark the opcode just after a start_memory, so we can test for an
3758 empty subpattern when we get to the stop_memory. */
3759 unsigned char *just_past_start_mem = 0;
3761 /* We use this to map every character in the string. */
3762 RE_TRANSLATE_TYPE translate = bufp->translate;
3764 /* Failure point stack. Each place that can handle a failure further
3765 down the line pushes a failure point on this stack. It consists of
3766 restart, regend, and reg_info for all registers corresponding to
3767 the subexpressions we're currently inside, plus the number of such
3768 registers, and, finally, two char *'s. The first char * is where
3769 to resume scanning the pattern; the second one is where to resume
3770 scanning the strings. If the latter is zero, the failure point is
3771 a ``dummy''; if a failure happens and the failure point is a dummy,
3772 it gets discarded and the next next one is tried. */
3773 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3774 fail_stack_type fail_stack;
3777 static unsigned failure_id = 0;
3778 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3782 /* This holds the pointer to the failure stack, when
3783 it is allocated relocatably. */
3784 fail_stack_elt_t *failure_stack_ptr;
3787 /* We fill all the registers internally, independent of what we
3788 return, for use in backreferences. The number here includes
3789 an element for register zero. */
3790 size_t num_regs = bufp->re_nsub + 1;
3792 /* The currently active registers. */
3793 active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3794 active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3796 /* Information on the contents of registers. These are pointers into
3797 the input strings; they record just what was matched (on this
3798 attempt) by a subexpression part of the pattern, that is, the
3799 regnum-th regstart pointer points to where in the pattern we began
3800 matching and the regnum-th regend points to right after where we
3801 stopped matching the regnum-th subexpression. (The zeroth register
3802 keeps track of what the whole pattern matches.) */
3803 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3804 const char **regstart, **regend;
3807 /* If a group that's operated upon by a repetition operator fails to
3808 match anything, then the register for its start will need to be
3809 restored because it will have been set to wherever in the string we
3810 are when we last see its open-group operator. Similarly for a
3812 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3813 const char **old_regstart, **old_regend;
3816 /* The is_active field of reg_info helps us keep track of which (possibly
3817 nested) subexpressions we are currently in. The matched_something
3818 field of reg_info[reg_num] helps us tell whether or not we have
3819 matched any of the pattern so far this time through the reg_num-th
3820 subexpression. These two fields get reset each time through any
3821 loop their register is in. */
3822 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3823 register_info_type *reg_info;
3826 /* The following record the register info as found in the above
3827 variables when we find a match better than any we've seen before.
3828 This happens as we backtrack through the failure points, which in
3829 turn happens only if we have not yet matched the entire string. */
3830 unsigned best_regs_set = false;
3832 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3833 const char **best_regstart, **best_regend;
3836 /* Logically, this is `best_regend[0]'. But we don't want to have to
3837 allocate space for that if we're not allocating space for anything
3838 else (see below). Also, we never need info about register 0 for
3839 any of the other register vectors, and it seems rather a kludge to
3840 treat `best_regend' differently than the rest. So we keep track of
3841 the end of the best match so far in a separate variable. We
3842 initialize this to NULL so that when we backtrack the first time
3843 and need to test it, it's not garbage. */
3844 const char *match_end = NULL;
3846 /* This helps SET_REGS_MATCHED avoid doing redundant work. */
3847 int set_regs_matched_done = 0;
3849 /* Used when we pop values we don't care about. */
3850 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3851 const char **reg_dummy;
3852 register_info_type *reg_info_dummy;
3856 /* Counts the total number of registers pushed. */
3857 unsigned num_regs_pushed = 0;
3860 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3864 #ifdef MATCH_MAY_ALLOCATE
3865 /* Do not bother to initialize all the register variables if there are
3866 no groups in the pattern, as it takes a fair amount of time. If
3867 there are groups, we include space for register 0 (the whole
3868 pattern), even though we never use it, since it simplifies the
3869 array indexing. We should fix this. */
3870 if (bufp->re_nsub) {
3871 regstart = REGEX_TALLOC (num_regs, const char *);
3872 regend = REGEX_TALLOC (num_regs, const char *);
3873 old_regstart = REGEX_TALLOC (num_regs, const char *);
3874 old_regend = REGEX_TALLOC (num_regs, const char *);
3875 best_regstart = REGEX_TALLOC (num_regs, const char *);
3876 best_regend = REGEX_TALLOC (num_regs, const char *);
3878 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3879 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3881 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3883 if (!(regstart && regend && old_regstart && old_regend && reg_info
3884 && best_regstart && best_regend && reg_dummy && reg_info_dummy)) {
3890 /* We must initialize all our variables to NULL, so that
3891 `FREE_VARIABLES' doesn't try to free them. */
3892 regstart = regend = old_regstart = old_regend = best_regstart
3893 = best_regend = reg_dummy = NULL;
3894 reg_info = reg_info_dummy = (register_info_type *) NULL;
3896 #endif /* MATCH_MAY_ALLOCATE */
3898 /* The starting position is bogus. */
3899 if (pos < 0 || pos > size1 + size2) {
3904 /* Initialize subexpression text positions to -1 to mark ones that no
3905 start_memory/stop_memory has been seen for. Also initialize the
3906 register information struct. */
3907 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++) {
3908 regstart[mcnt] = regend[mcnt]
3909 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3911 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3912 IS_ACTIVE (reg_info[mcnt]) = 0;
3913 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3914 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3917 /* We move `string1' into `string2' if the latter's empty -- but not if
3918 `string1' is null. */
3919 if (size2 == 0 && string1 != NULL) {
3925 end1 = string1 + size1;
3926 end2 = string2 + size2;
3928 /* Compute where to stop matching, within the two strings. */
3929 if (stop <= size1) {
3930 end_match_1 = string1 + stop;
3931 end_match_2 = string2;
3935 end_match_2 = string2 + stop - size1;
3938 /* `p' scans through the pattern as `d' scans through the data.
3939 `dend' is the end of the input string that `d' points within. `d'
3940 is advanced into the following input string whenever necessary, but
3941 this happens before fetching; therefore, at the beginning of the
3942 loop, `d' can be pointing at the end of a string, but it cannot
3944 if (size1 > 0 && pos <= size1) {
3949 d = string2 + pos - size1;
3953 DEBUG_PRINT1 ("The compiled pattern is:\n");
3954 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3955 DEBUG_PRINT1 ("The string to match is: `");
3956 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3957 DEBUG_PRINT1 ("'\n");
3959 /* This loops over pattern commands. It exits by returning from the
3960 function if the match is complete, or it drops through if the match
3961 fails at this starting point in the input data. */
3964 DEBUG_PRINT2 ("\n%p: ", p);
3966 DEBUG_PRINT2 ("\n0x%x: ", p);
3969 if (p == pend) { /* End of pattern means we might have succeeded. */
3970 DEBUG_PRINT1 ("end of pattern ... ");
3972 /* If we haven't matched the entire string, and we want the
3973 longest match, try backtracking. */
3974 if (d != end_match_2) {
3975 /* 1 if this match ends in the same string (string1 or string2)
3976 as the best previous match. */
3977 boolean same_str_p = (FIRST_STRING_P (match_end)
3978 == MATCHING_IN_FIRST_STRING);
3980 /* 1 if this match is the best seen so far. */
3981 boolean best_match_p;
3983 /* AIX compiler got confused when this was combined
3984 with the previous declaration. */
3986 best_match_p = d > match_end;
3988 best_match_p = !MATCHING_IN_FIRST_STRING;
3990 DEBUG_PRINT1 ("backtracking.\n");
3992 if (!FAIL_STACK_EMPTY ()) { /* More failure points to try. */
3994 /* If exceeds best match so far, save it. */
3995 if (!best_regs_set || best_match_p) {
3996 best_regs_set = true;
3999 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
4001 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++) {
4002 best_regstart[mcnt] = regstart[mcnt];
4003 best_regend[mcnt] = regend[mcnt];
4009 /* If no failure points, don't restore garbage. And if
4010 last match is real best match, don't restore second
4012 else if (best_regs_set && !best_match_p) {
4014 /* Restore best match. It may happen that `dend ==
4015 end_match_1' while the restored d is in string2.
4016 For example, the pattern `x.*y.*z' against the
4017 strings `x-' and `y-z-', if the two strings are
4018 not consecutive in memory. */
4019 DEBUG_PRINT1 ("Restoring best registers.\n");
4022 dend = ((d >= string1 && d <= end1)
4023 ? end_match_1 : end_match_2);
4025 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++) {
4026 regstart[mcnt] = best_regstart[mcnt];
4027 regend[mcnt] = best_regend[mcnt];
4030 } /* d != end_match_2 */
4033 DEBUG_PRINT1 ("Accepting match.\n");
4035 /* If caller wants register contents data back, do it. */
4036 if (regs && !bufp->no_sub) {
4037 /* Have the register data arrays been allocated? */
4038 if (bufp->regs_allocated == REGS_UNALLOCATED) { /* No. So allocate them with malloc. We need one
4039 extra element beyond `num_regs' for the `-1' marker
4041 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
4042 regs->start = TALLOC (regs->num_regs, regoff_t);
4043 regs->end = TALLOC (regs->num_regs, regoff_t);
4044 if (regs->start == NULL || regs->end == NULL) {
4048 bufp->regs_allocated = REGS_REALLOCATE;
4050 else if (bufp->regs_allocated == REGS_REALLOCATE) { /* Yes. If we need more elements than were already
4051 allocated, reallocate them. If we need fewer, just
4053 if (regs->num_regs < num_regs + 1) {
4054 regs->num_regs = num_regs + 1;
4055 RETALLOC (regs->start, regs->num_regs, regoff_t);
4056 RETALLOC (regs->end, regs->num_regs, regoff_t);
4057 if (regs->start == NULL || regs->end == NULL) {
4064 /* These braces fend off a "empty body in an else-statement"
4065 warning under GCC when assert expands to nothing. */
4066 assert (bufp->regs_allocated == REGS_FIXED);
4069 /* Convert the pointer data in `regstart' and `regend' to
4070 indices. Register zero has to be set differently,
4071 since we haven't kept track of any info for it. */
4072 if (regs->num_regs > 0) {
4073 regs->start[0] = pos;
4074 regs->end[0] = (MATCHING_IN_FIRST_STRING
4075 ? ((regoff_t) (d - string1))
4076 : ((regoff_t) (d - string2 + size1)));
4079 /* Go through the first `min (num_regs, regs->num_regs)'
4080 registers, since that is all we initialized. */
4081 for (mcnt = 1; (unsigned) mcnt < MIN (num_regs, regs->num_regs);
4083 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
4084 regs->start[mcnt] = regs->end[mcnt] = -1;
4087 = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
4089 = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
4093 /* If the regs structure we return has more elements than
4094 were in the pattern, set the extra elements to -1. If
4095 we (re)allocated the registers, this is the case,
4096 because we always allocate enough to have at least one
4098 for (mcnt = num_regs; (unsigned) mcnt < regs->num_regs; mcnt++)
4099 regs->start[mcnt] = regs->end[mcnt] = -1;
4100 } /* regs && !bufp->no_sub */
4102 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
4103 nfailure_points_pushed, nfailure_points_popped,
4104 nfailure_points_pushed - nfailure_points_popped);
4105 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
4107 mcnt = d - pos - (MATCHING_IN_FIRST_STRING ? string1 : string2 - size1);
4109 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
4115 /* Otherwise match next pattern command. */
4116 switch (SWITCH_ENUM_CAST ((re_opcode_t) * p++)) {
4117 /* Ignore these. Used to ignore the n of succeed_n's which
4118 currently have n == 0. */
4120 DEBUG_PRINT1 ("EXECUTING no_op.\n");
4124 DEBUG_PRINT1 ("EXECUTING succeed.\n");
4127 /* Match the next n pattern characters exactly. The following
4128 byte in the pattern defines n, and the n bytes after that
4129 are the characters to match. */
4132 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
4134 /* This is written out as an if-else so we don't waste time
4135 testing `translate' inside the loop. */
4139 if ((unsigned char) translate[(unsigned char) *d++]
4140 != (unsigned char) *p++)
4148 if (*d++ != (char) *p++)
4153 SET_REGS_MATCHED ();
4157 /* Match any character except possibly a newline or a null. */
4159 DEBUG_PRINT1 ("EXECUTING anychar.\n");
4163 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
4164 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
4167 SET_REGS_MATCHED ();
4168 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
4176 register unsigned char c;
4177 boolean not = (re_opcode_t) * (p - 1) == charset_not;
4179 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
4182 c = TRANSLATE (*d); /* The character to match. */
4184 /* Cast to `unsigned' instead of `unsigned char' in case the
4185 bit list is a full 32 bytes long. */
4186 if (c < (unsigned) (*p * BYTEWIDTH)
4187 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4195 SET_REGS_MATCHED ();
4201 /* The beginning of a group is represented by start_memory.
4202 The arguments are the register number in the next byte, and the
4203 number of groups inner to this one in the next. The text
4204 matched within the group is recorded (in the internal
4205 registers data structure) under the register number. */
4207 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
4209 /* Find out if this group can match the empty string. */
4210 p1 = p; /* To send to group_match_null_string_p. */
4212 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
4213 REG_MATCH_NULL_STRING_P (reg_info[*p])
4214 = group_match_null_string_p (&p1, pend, reg_info);
4216 /* Save the position in the string where we were the last time
4217 we were at this open-group operator in case the group is
4218 operated upon by a repetition operator, e.g., with `(a*)*b'
4219 against `ab'; then we want to ignore where we are now in
4220 the string in case this attempt to match fails. */
4221 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4222 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
4224 DEBUG_PRINT2 (" old_regstart: %d\n",
4225 POINTER_TO_OFFSET (old_regstart[*p]));
4228 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
4230 IS_ACTIVE (reg_info[*p]) = 1;
4231 MATCHED_SOMETHING (reg_info[*p]) = 0;
4233 /* Clear this whenever we change the register activity status. */
4234 set_regs_matched_done = 0;
4236 /* This is the new highest active register. */
4237 highest_active_reg = *p;
4239 /* If nothing was active before, this is the new lowest active
4241 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4242 lowest_active_reg = *p;
4244 /* Move past the register number and inner group count. */
4246 just_past_start_mem = p;
4251 /* The stop_memory opcode represents the end of a group. Its
4252 arguments are the same as start_memory's: the register
4253 number, and the number of inner groups. */
4255 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
4257 /* We need to save the string position the last time we were at
4258 this close-group operator in case the group is operated
4259 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
4260 against `aba'; then we want to ignore where we are now in
4261 the string in case this attempt to match fails. */
4262 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4263 ? REG_UNSET (regend[*p]) ? d : regend[*p]
4265 DEBUG_PRINT2 (" old_regend: %d\n",
4266 POINTER_TO_OFFSET (old_regend[*p]));
4269 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
4271 /* This register isn't active anymore. */
4272 IS_ACTIVE (reg_info[*p]) = 0;
4274 /* Clear this whenever we change the register activity status. */
4275 set_regs_matched_done = 0;
4277 /* If this was the only register active, nothing is active
4279 if (lowest_active_reg == highest_active_reg) {
4280 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4281 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4283 else { /* We must scan for the new highest active register, since
4284 it isn't necessarily one less than now: consider
4285 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
4286 new highest active register is 1. */
4287 unsigned char r = *p - 1;
4289 while (r > 0 && !IS_ACTIVE (reg_info[r]))
4292 /* If we end up at register zero, that means that we saved
4293 the registers as the result of an `on_failure_jump', not
4294 a `start_memory', and we jumped to past the innermost
4295 `stop_memory'. For example, in ((.)*) we save
4296 registers 1 and 2 as a result of the *, but when we pop
4297 back to the second ), we are at the stop_memory 1.
4298 Thus, nothing is active. */
4300 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4301 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4304 highest_active_reg = r;
4307 /* If just failed to match something this time around with a
4308 group that's operated on by a repetition operator, try to
4309 force exit from the ``loop'', and restore the register
4310 information for this group that we had before trying this
4312 if ((!MATCHED_SOMETHING (reg_info[*p])
4313 || just_past_start_mem == p - 1)
4314 && (p + 2) < pend) {
4315 boolean is_a_jump_n = false;
4319 switch ((re_opcode_t) * p1++) {
4322 case pop_failure_jump:
4323 case maybe_pop_jump:
4325 case dummy_failure_jump:
4326 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4336 /* If the next operation is a jump backwards in the pattern
4337 to an on_failure_jump right before the start_memory
4338 corresponding to this stop_memory, exit from the loop
4339 by forcing a failure after pushing on the stack the
4340 on_failure_jump's jump in the pattern, and d. */
4341 if (mcnt < 0 && (re_opcode_t) * p1 == on_failure_jump
4342 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p) {
4343 /* If this group ever matched anything, then restore
4344 what its registers were before trying this last
4345 failed match, e.g., with `(a*)*b' against `ab' for
4346 regstart[1], and, e.g., with `((a*)*(b*)*)*'
4347 against `aba' for regend[3].
4349 Also restore the registers for inner groups for,
4350 e.g., `((a*)(b*))*' against `aba' (register 3 would
4351 otherwise get trashed). */
4353 if (EVER_MATCHED_SOMETHING (reg_info[*p])) {
4356 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
4358 /* Restore this and inner groups' (if any) registers. */
4359 for (r = *p; r < (unsigned) *p + (unsigned) *(p + 1); r++) {
4360 regstart[r] = old_regstart[r];
4362 /* xx why this test? */
4363 if (old_regend[r] >= regstart[r])
4364 regend[r] = old_regend[r];
4368 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4369 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
4375 /* Move past the register number and the inner group count. */
4380 /* \<digit> has been turned into a `duplicate' command which is
4381 followed by the numeric value of <digit> as the register number. */
4384 register const char *d2, *dend2;
4385 int regno = *p++; /* Get which register to match against. */
4387 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
4389 /* Can't back reference a group which we've never matched. */
4390 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
4393 /* Where in input to try to start matching. */
4394 d2 = regstart[regno];
4396 /* Where to stop matching; if both the place to start and
4397 the place to stop matching are in the same string, then
4398 set to the place to stop, otherwise, for now have to use
4399 the end of the first string. */
4401 dend2 = ((FIRST_STRING_P (regstart[regno])
4402 == FIRST_STRING_P (regend[regno]))
4403 ? regend[regno] : end_match_1);
4405 /* If necessary, advance to next segment in register
4407 while (d2 == dend2) {
4408 if (dend2 == end_match_2)
4410 if (dend2 == regend[regno])
4413 /* End of string1 => advance to string2. */
4415 dend2 = regend[regno];
4417 /* At end of register contents => success */
4421 /* If necessary, advance to next segment in data. */
4424 /* How many characters left in this segment to match. */
4427 /* Want how many consecutive characters we can match in
4428 one shot, so, if necessary, adjust the count. */
4429 if (mcnt > dend2 - d2)
4432 /* Compare that many; failure if mismatch, else move
4434 if (translate ? bcmp_translate (d, d2, mcnt, translate)
4435 : bcmp (d, d2, mcnt))
4437 d += mcnt, d2 += mcnt;
4439 /* Do this because we've match some characters. */
4440 SET_REGS_MATCHED ();
4446 /* begline matches the empty string at the beginning of the string
4447 (unless `not_bol' is set in `bufp'), and, if
4448 `newline_anchor' is set, after newlines. */
4450 DEBUG_PRINT1 ("EXECUTING begline.\n");
4452 if (AT_STRINGS_BEG (d)) {
4456 else if (d[-1] == '\n' && bufp->newline_anchor) {
4459 /* In all other cases, we fail. */
4463 /* endline is the dual of begline. */
4465 DEBUG_PRINT1 ("EXECUTING endline.\n");
4467 if (AT_STRINGS_END (d)) {
4472 /* We have to ``prefetch'' the next character. */
4473 else if ((d == end1 ? *string2 : *d) == '\n' && bufp->newline_anchor) {
4479 /* Match at the very beginning of the data. */
4481 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4482 if (AT_STRINGS_BEG (d))
4487 /* Match at the very end of the data. */
4489 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4490 if (AT_STRINGS_END (d))
4495 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
4496 pushes NULL as the value for the string on the stack. Then
4497 `pop_failure_point' will keep the current value for the
4498 string, instead of restoring it. To see why, consider
4499 matching `foo\nbar' against `.*\n'. The .* matches the foo;
4500 then the . fails against the \n. But the next thing we want
4501 to do is match the \n against the \n; if we restored the
4502 string value, we would be back at the foo.
4504 Because this is used only in specific cases, we don't need to
4505 check all the things that `on_failure_jump' does, to make
4506 sure the right things get saved on the stack. Hence we don't
4507 share its code. The only reason to push anything on the
4508 stack at all is that otherwise we would have to change
4509 `anychar's code to do something besides goto fail in this
4510 case; that seems worse than this. */
4511 case on_failure_keep_string_jump:
4512 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4514 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4516 DEBUG_PRINT3 (" %d (to %p):\n", mcnt, p + mcnt);
4518 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4521 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4525 /* Uses of on_failure_jump:
4527 Each alternative starts with an on_failure_jump that points
4528 to the beginning of the next alternative. Each alternative
4529 except the last ends with a jump that in effect jumps past
4530 the rest of the alternatives. (They really jump to the
4531 ending jump of the following alternative, because tensioning
4532 these jumps is a hassle.)
4534 Repeats start with an on_failure_jump that points past both
4535 the repetition text and either the following jump or
4536 pop_failure_jump back to this on_failure_jump. */
4537 case on_failure_jump:
4539 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4541 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4543 DEBUG_PRINT3 (" %d (to %p)", mcnt, p + mcnt);
4545 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4548 /* If this on_failure_jump comes right before a group (i.e.,
4549 the original * applied to a group), save the information
4550 for that group and all inner ones, so that if we fail back
4551 to this point, the group's information will be correct.
4552 For example, in \(a*\)*\1, we need the preceding group,
4553 and in \(zz\(a*\)b*\)\2, we need the inner group. */
4555 /* We can't use `p' to check ahead because we push
4556 a failure point to `p + mcnt' after we do this. */
4559 /* We need to skip no_op's before we look for the
4560 start_memory in case this on_failure_jump is happening as
4561 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
4563 while (p1 < pend && (re_opcode_t) * p1 == no_op)
4566 if (p1 < pend && (re_opcode_t) * p1 == start_memory) {
4567 /* We have a new highest active register now. This will
4568 get reset at the start_memory we are about to get to,
4569 but we will have saved all the registers relevant to
4570 this repetition op, as described above. */
4571 highest_active_reg = *(p1 + 1) + *(p1 + 2);
4572 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4573 lowest_active_reg = *(p1 + 1);
4576 DEBUG_PRINT1 (":\n");
4577 PUSH_FAILURE_POINT (p + mcnt, d, -2);
4581 /* A smart repeat ends with `maybe_pop_jump'.
4582 We change it to either `pop_failure_jump' or `jump'. */
4583 case maybe_pop_jump:
4584 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4585 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4587 register unsigned char *p2 = p;
4589 /* Compare the beginning of the repeat with what in the
4590 pattern follows its end. If we can establish that there
4591 is nothing that they would both match, i.e., that we
4592 would have to backtrack because of (as in, e.g., `a*a')
4593 then we can change to pop_failure_jump, because we'll
4594 never have to backtrack.
4596 This is not true in the case of alternatives: in
4597 `(a|ab)*' we do need to backtrack to the `ab' alternative
4598 (e.g., if the string was `ab'). But instead of trying to
4599 detect that here, the alternative has put on a dummy
4600 failure point which is what we will end up popping. */
4602 /* Skip over open/close-group commands.
4603 If what follows this loop is a ...+ construct,
4604 look at what begins its body, since we will have to
4605 match at least one of that. */
4608 && ((re_opcode_t) * p2 == stop_memory
4609 || (re_opcode_t) * p2 == start_memory))
4611 else if (p2 + 6 < pend && (re_opcode_t) * p2 == dummy_failure_jump)
4618 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4619 to the `maybe_finalize_jump' of this case. Examine what
4622 /* If we're at the end of the pattern, we can change. */
4624 /* Consider what happens when matching ":\(.*\)"
4625 against ":/". I don't really understand this code
4627 p[-3] = (unsigned char) pop_failure_jump;
4628 DEBUG_PRINT1 (" End of pattern: change to `pop_failure_jump'.\n");
4631 else if ((re_opcode_t) * p2 == exactn
4632 || (bufp->newline_anchor && (re_opcode_t) * p2 == endline)) {
4633 register unsigned char c
4634 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4636 if ((re_opcode_t) p1[3] == exactn && p1[5] != c) {
4637 p[-3] = (unsigned char) pop_failure_jump;
4638 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n", c, p1[5]);
4641 else if ((re_opcode_t) p1[3] == charset
4642 || (re_opcode_t) p1[3] == charset_not) {
4643 int not = (re_opcode_t) p1[3] == charset_not;
4645 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4646 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4649 /* `not' is equal to 1 if c would match, which means
4650 that we can't change to pop_failure_jump. */
4652 p[-3] = (unsigned char) pop_failure_jump;
4653 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4657 else if ((re_opcode_t) * p2 == charset) {
4659 register unsigned char c
4660 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4664 if ((re_opcode_t) p1[3] == exactn
4665 && !((int) p2[1] * BYTEWIDTH > (int) p1[5]
4666 && (p2[2 + p1[5] / BYTEWIDTH]
4667 & (1 << (p1[5] % BYTEWIDTH)))))
4669 if ((re_opcode_t) p1[3] == exactn
4670 && !((int) p2[1] * BYTEWIDTH > (int) p1[4]
4671 && (p2[2 + p1[4] / BYTEWIDTH]
4672 & (1 << (p1[4] % BYTEWIDTH)))))
4675 p[-3] = (unsigned char) pop_failure_jump;
4676 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n", c, p1[5]);
4679 else if ((re_opcode_t) p1[3] == charset_not) {
4682 /* We win if the charset_not inside the loop
4683 lists every character listed in the charset after. */
4684 for (idx = 0; idx < (int) p2[1]; idx++)
4685 if (!(p2[2 + idx] == 0 || (idx < (int) p1[4]
4686 && ((p2[2 + idx] & ~p1[5 + idx]) ==
4691 p[-3] = (unsigned char) pop_failure_jump;
4692 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4695 else if ((re_opcode_t) p1[3] == charset) {
4698 /* We win if the charset inside the loop
4699 has no overlap with the one after the loop. */
4700 for (idx = 0; idx < (int) p2[1] && idx < (int) p1[4]; idx++)
4701 if ((p2[2 + idx] & p1[5 + idx]) != 0)
4704 if (idx == p2[1] || idx == p1[4]) {
4705 p[-3] = (unsigned char) pop_failure_jump;
4706 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4711 p -= 2; /* Point at relative address again. */
4712 if ((re_opcode_t) p[-1] != pop_failure_jump) {
4713 p[-1] = (unsigned char) jump;
4714 DEBUG_PRINT1 (" Match => jump.\n");
4715 goto unconditional_jump;
4717 /* Note fall through. */
4720 /* The end of a simple repeat has a pop_failure_jump back to
4721 its matching on_failure_jump, where the latter will push a
4722 failure point. The pop_failure_jump takes off failure
4723 points put on by this pop_failure_jump's matching
4724 on_failure_jump; we got through the pattern to here from the
4725 matching on_failure_jump, so didn't fail. */
4726 case pop_failure_jump:
4728 /* We need to pass separate storage for the lowest and
4729 highest registers, even though we don't care about the
4730 actual values. Otherwise, we will restore only one
4731 register from the stack, since lowest will == highest in
4732 `pop_failure_point'. */
4733 active_reg_t dummy_low_reg, dummy_high_reg;
4734 unsigned char *pdummy;
4737 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4738 POP_FAILURE_POINT (sdummy, pdummy,
4739 dummy_low_reg, dummy_high_reg,
4740 reg_dummy, reg_dummy, reg_info_dummy);
4742 /* Note fall through. */
4746 DEBUG_PRINT2 ("\n%p: ", p);
4748 DEBUG_PRINT2 ("\n0x%x: ", p);
4750 /* Note fall through. */
4752 /* Unconditionally jump (without popping any failure points). */
4754 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4755 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4756 p += mcnt; /* Do the jump. */
4758 DEBUG_PRINT2 ("(to %p).\n", p);
4760 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4765 /* We need this opcode so we can detect where alternatives end
4766 in `group_match_null_string_p' et al. */
4768 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4769 goto unconditional_jump;
4772 /* Normally, the on_failure_jump pushes a failure point, which
4773 then gets popped at pop_failure_jump. We will end up at
4774 pop_failure_jump, also, and with a pattern of, say, `a+', we
4775 are skipping over the on_failure_jump, so we have to push
4776 something meaningless for pop_failure_jump to pop. */
4777 case dummy_failure_jump:
4778 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4779 /* It doesn't matter what we push for the string here. What
4780 the code at `fail' tests is the value for the pattern. */
4781 PUSH_FAILURE_POINT (0, 0, -2);
4782 goto unconditional_jump;
4785 /* At the end of an alternative, we need to push a dummy failure
4786 point in case we are followed by a `pop_failure_jump', because
4787 we don't want the failure point for the alternative to be
4788 popped. For example, matching `(a|ab)*' against `aab'
4789 requires that we match the `ab' alternative. */
4790 case push_dummy_failure:
4791 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4792 /* See comments just above at `dummy_failure_jump' about the
4794 PUSH_FAILURE_POINT (0, 0, -2);
4797 /* Have to succeed matching what follows at least n times.
4798 After that, handle like `on_failure_jump'. */
4800 EXTRACT_NUMBER (mcnt, p + 2);
4801 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4804 /* Originally, this is how many times we HAVE to succeed. */
4808 STORE_NUMBER_AND_INCR (p, mcnt);
4810 DEBUG_PRINT3 (" Setting %p to %d.\n", p - 2, mcnt);
4812 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p - 2, mcnt);
4815 else if (mcnt == 0) {
4817 DEBUG_PRINT2 (" Setting two bytes from %p to no_op.\n", p + 2);
4819 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p + 2);
4821 p[2] = (unsigned char) no_op;
4822 p[3] = (unsigned char) no_op;
4828 EXTRACT_NUMBER (mcnt, p + 2);
4829 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4831 /* Originally, this is how many times we CAN jump. */
4834 STORE_NUMBER (p + 2, mcnt);
4836 DEBUG_PRINT3 (" Setting %p to %d.\n", p + 2, mcnt);
4838 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p + 2, mcnt);
4840 goto unconditional_jump;
4842 /* If don't have to jump any more, skip over the rest of command. */
4849 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4851 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4853 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4855 DEBUG_PRINT3 (" Setting %p to %d.\n", p1, mcnt);
4857 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4859 STORE_NUMBER (p1, mcnt);
4864 /* The DEC Alpha C compiler 3.x generates incorrect code for the
4865 test WORDCHAR_P (d - 1) != WORDCHAR_P (d) in the expansion of
4866 AT_WORD_BOUNDARY, so this code is disabled. Expanding the
4867 macro and introducing temporary variables works around the bug. */
4870 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4871 if (AT_WORD_BOUNDARY (d))
4876 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4877 if (AT_WORD_BOUNDARY (d))
4883 boolean prevchar, thischar;
4885 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4886 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4889 prevchar = WORDCHAR_P (d - 1);
4890 thischar = WORDCHAR_P (d);
4891 if (prevchar != thischar)
4898 boolean prevchar, thischar;
4900 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4901 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4904 prevchar = WORDCHAR_P (d - 1);
4905 thischar = WORDCHAR_P (d);
4906 if (prevchar != thischar)
4913 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4914 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4919 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4920 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4921 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4927 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4928 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4933 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4934 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4939 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4940 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4945 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4950 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4954 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4956 if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
4958 SET_REGS_MATCHED ();
4962 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4964 goto matchnotsyntax;
4967 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4971 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4973 if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
4975 SET_REGS_MATCHED ();
4978 #else /* not emacs */
4980 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4982 if (!WORDCHAR_P (d))
4984 SET_REGS_MATCHED ();
4989 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4993 SET_REGS_MATCHED ();
4996 #endif /* not emacs */
5001 continue; /* Successfully executed one pattern command; keep going. */
5004 /* We goto here if a matching operation fails. */
5006 if (!FAIL_STACK_EMPTY ()) { /* A restart point is known. Restore to that state. */
5007 DEBUG_PRINT1 ("\nFAIL:\n");
5008 POP_FAILURE_POINT (d, p,
5009 lowest_active_reg, highest_active_reg,
5010 regstart, regend, reg_info);
5012 /* If this failure point is a dummy, try the next one. */
5016 /* If we failed to the end of the pattern, don't examine *p. */
5019 boolean is_a_jump_n = false;
5021 /* If failed to a backwards jump that's part of a repetition
5022 loop, need to pop this failure point and use the next one. */
5023 switch ((re_opcode_t) * p) {
5026 case maybe_pop_jump:
5027 case pop_failure_jump:
5030 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5033 if ((is_a_jump_n && (re_opcode_t) * p1 == succeed_n)
5034 || (!is_a_jump_n && (re_opcode_t) * p1 == on_failure_jump))
5042 if (d >= string1 && d <= end1)
5046 break; /* Matching at this starting point really fails. */
5050 goto restore_best_regs;
5054 return -1; /* Failure to match. */
5057 /* Subroutine definitions for re_match_2. */
5060 /* We are passed P pointing to a register number after a start_memory.
5062 Return true if the pattern up to the corresponding stop_memory can
5063 match the empty string, and false otherwise.
5065 If we find the matching stop_memory, sets P to point to one past its number.
5066 Otherwise, sets P to an undefined byte less than or equal to END.
5068 We don't handle duplicates properly (yet). */
5070 static boolean group_match_null_string_p (p, end, reg_info)
5071 unsigned char **p, *end;
5072 register_info_type *reg_info;
5076 /* Point to after the args to the start_memory. */
5077 unsigned char *p1 = *p + 2;
5080 /* Skip over opcodes that can match nothing, and return true or
5081 false, as appropriate, when we get to one that can't, or to the
5082 matching stop_memory. */
5084 switch ((re_opcode_t) * p1) {
5085 /* Could be either a loop or a series of alternatives. */
5086 case on_failure_jump:
5088 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5090 /* If the next operation is not a jump backwards in the
5094 /* Go through the on_failure_jumps of the alternatives,
5095 seeing if any of the alternatives cannot match nothing.
5096 The last alternative starts with only a jump,
5097 whereas the rest start with on_failure_jump and end
5098 with a jump, e.g., here is the pattern for `a|b|c':
5100 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
5101 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
5104 So, we have to first go through the first (n-1)
5105 alternatives and then deal with the last one separately. */
5108 /* Deal with the first (n-1) alternatives, which start
5109 with an on_failure_jump (see above) that jumps to right
5110 past a jump_past_alt. */
5112 while ((re_opcode_t) p1[mcnt - 3] == jump_past_alt) {
5113 /* `mcnt' holds how many bytes long the alternative
5114 is, including the ending `jump_past_alt' and
5117 if (!alt_match_null_string_p (p1, p1 + mcnt - 3, reg_info))
5120 /* Move to right after this alternative, including the
5124 /* Break if it's the beginning of an n-th alternative
5125 that doesn't begin with an on_failure_jump. */
5126 if ((re_opcode_t) * p1 != on_failure_jump)
5129 /* Still have to check that it's not an n-th
5130 alternative that starts with an on_failure_jump. */
5132 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5133 if ((re_opcode_t) p1[mcnt - 3] != jump_past_alt) {
5134 /* Get to the beginning of the n-th alternative. */
5140 /* Deal with the last alternative: go back and get number
5141 of the `jump_past_alt' just before it. `mcnt' contains
5142 the length of the alternative. */
5143 EXTRACT_NUMBER (mcnt, p1 - 2);
5145 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
5148 p1 += mcnt; /* Get past the n-th alternative. */
5154 assert (p1[1] == **p);
5160 if (!common_op_match_null_string_p (&p1, end, reg_info))
5163 } /* while p1 < end */
5166 } /* group_match_null_string_p */
5169 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
5170 It expects P to be the first byte of a single alternative and END one
5171 byte past the last. The alternative can contain groups. */
5173 static boolean alt_match_null_string_p (p, end, reg_info)
5174 unsigned char *p, *end;
5175 register_info_type *reg_info;
5178 unsigned char *p1 = p;
5181 /* Skip over opcodes that can match nothing, and break when we get
5182 to one that can't. */
5184 switch ((re_opcode_t) * p1) {
5186 case on_failure_jump:
5188 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5193 if (!common_op_match_null_string_p (&p1, end, reg_info))
5196 } /* while p1 < end */
5199 } /* alt_match_null_string_p */
5202 /* Deals with the ops common to group_match_null_string_p and
5203 alt_match_null_string_p.
5205 Sets P to one after the op and its arguments, if any. */
5207 static boolean common_op_match_null_string_p (p, end, reg_info)
5208 unsigned char **p, *end;
5209 register_info_type *reg_info;
5214 unsigned char *p1 = *p;
5216 switch ((re_opcode_t) * p1++) {
5235 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
5236 ret = group_match_null_string_p (&p1, end, reg_info);
5238 /* Have to set this here in case we're checking a group which
5239 contains a group and a back reference to it. */
5241 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
5242 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
5248 /* If this is an optimized succeed_n for zero times, make the jump. */
5250 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5258 /* Get to the number of times to succeed. */
5260 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5264 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5272 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
5280 /* All other opcodes mean we cannot match the empty string. */
5286 } /* common_op_match_null_string_p */
5289 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
5290 bytes; nonzero otherwise. */
5292 static int bcmp_translate (s1, s2, len, translate)
5293 const char *s1, *s2;
5295 RE_TRANSLATE_TYPE translate;
5297 register const unsigned char *p1 = (const unsigned char *) s1;
5298 register const unsigned char *p2 = (const unsigned char *) s2;
5301 if (translate[*p1++] != translate[*p2++])
5308 /* Entry points for GNU code. */
5310 /* re_compile_pattern is the GNU regular expression compiler: it
5311 compiles PATTERN (of length SIZE) and puts the result in BUFP.
5312 Returns 0 if the pattern was valid, otherwise an error string.
5314 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
5315 are set in BUFP on entry.
5317 We call regex_compile to do the actual compilation. */
5319 const char *re_compile_pattern (pattern, length, bufp)
5320 const char *pattern;
5322 struct re_pattern_buffer *bufp;
5326 /* GNU code is written to assume at least RE_NREGS registers will be set
5327 (and at least one extra will be -1). */
5328 bufp->regs_allocated = REGS_UNALLOCATED;
5330 /* And GNU code determines whether or not to get register information
5331 by passing null for the REGS argument to re_match, etc., not by
5335 /* Match anchors at newline. */
5336 bufp->newline_anchor = 1;
5338 ret = regex_compile (pattern, length, re_syntax_options, bufp);
5342 return gettext (re_error_msgid[(int) ret]);
5345 /* Entry points compatible with 4.2 BSD regex library. We don't define
5346 them unless specifically requested. */
5348 #if defined (_REGEX_RE_COMP) || defined (_LIBC)
5350 /* BSD has one and only one pattern buffer. */
5351 static struct re_pattern_buffer re_comp_buf;
5355 /* Make these definitions weak in libc, so POSIX programs can redefine
5356 these names if they don't use our functions, and still use
5357 regcomp/regexec below without link errors. */
5366 if (!re_comp_buf.buffer)
5367 return gettext ("No previous regular expression");
5371 if (!re_comp_buf.buffer) {
5372 re_comp_buf.buffer = (unsigned char *) malloc (200); /* __MEM_CHECKED__ */
5373 if (re_comp_buf.buffer == NULL)
5374 return gettext (re_error_msgid[(int) REG_ESPACE]);
5375 re_comp_buf.allocated = 200;
5377 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH); /* __MEM_CHECKED__ */
5378 if (re_comp_buf.fastmap == NULL)
5379 return gettext (re_error_msgid[(int) REG_ESPACE]);
5382 /* Since `re_exec' always passes NULL for the `regs' argument, we
5383 don't need to initialize the pattern buffer fields which affect it. */
5385 /* Match anchors at newlines. */
5386 re_comp_buf.newline_anchor = 1;
5388 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
5393 /* Yes, we're discarding `const' here if !HAVE_LIBINTL. */
5394 return (char *) gettext (re_error_msgid[(int) ret]);
5405 const int len = strlen (s);
5408 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
5411 #endif /* _REGEX_RE_COMP */
5413 /* POSIX.2 functions. Don't define these for Emacs. */
5417 /* regcomp takes a regular expression as a string and compiles it.
5419 PREG is a regex_t *. We do not expect any fields to be initialized,
5420 since POSIX says we shouldn't. Thus, we set
5422 `buffer' to the compiled pattern;
5423 `used' to the length of the compiled pattern;
5424 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
5425 REG_EXTENDED bit in CFLAGS is set; otherwise, to
5426 RE_SYNTAX_POSIX_BASIC;
5427 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
5428 `fastmap' and `fastmap_accurate' to zero;
5429 `re_nsub' to the number of subexpressions in PATTERN.
5431 PATTERN is the address of the pattern string.
5433 CFLAGS is a series of bits which affect compilation.
5435 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
5436 use POSIX basic syntax.
5438 If REG_NEWLINE is set, then . and [^...] don't match newline.
5439 Also, regexec will try a match beginning after every newline.
5441 If REG_ICASE is set, then we considers upper- and lowercase
5442 versions of letters to be equivalent when matching.
5444 If REG_NOSUB is set, then when PREG is passed to regexec, that
5445 routine will report only success or failure, and nothing about the
5448 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
5449 the return codes and their meanings.) */
5451 int regcomp (preg, pattern, cflags)
5453 const char *pattern;
5458 = (cflags & REG_EXTENDED) ?
5459 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
5461 /* regex_compile will allocate the space for the compiled pattern. */
5463 preg->allocated = 0;
5466 /* Don't bother to use a fastmap when searching. This simplifies the
5467 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
5468 characters after newlines into the fastmap. This way, we just try
5472 if (cflags & REG_ICASE) {
5475 preg->translate = (RE_TRANSLATE_TYPE) malloc (CHAR_SET_SIZE /* __MEM_CHECKED__ */
5477 sizeof (*(RE_TRANSLATE_TYPE)
5479 if (preg->translate == NULL)
5480 return (int) REG_ESPACE;
5482 /* Map uppercase characters to corresponding lowercase ones. */
5483 for (i = 0; i < CHAR_SET_SIZE; i++)
5484 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
5487 preg->translate = NULL;
5489 /* If REG_NEWLINE is set, newlines are treated differently. */
5490 if (cflags & REG_NEWLINE) { /* REG_NEWLINE implies neither . nor [^...] match newline. */
5491 syntax &= ~RE_DOT_NEWLINE;
5492 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
5493 /* It also changes the matching behavior. */
5494 preg->newline_anchor = 1;
5497 preg->newline_anchor = 0;
5499 preg->no_sub = !!(cflags & REG_NOSUB);
5501 /* POSIX says a null character in the pattern terminates it, so we
5502 can use strlen here in compiling the pattern. */
5503 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
5505 /* POSIX doesn't distinguish between an unmatched open-group and an
5506 unmatched close-group: both are REG_EPAREN. */
5507 if (ret == REG_ERPAREN)
5514 /* regexec searches for a given pattern, specified by PREG, in the
5517 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
5518 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
5519 least NMATCH elements, and we set them to the offsets of the
5520 corresponding matched substrings.
5522 EFLAGS specifies `execution flags' which affect matching: if
5523 REG_NOTBOL is set, then ^ does not match at the beginning of the
5524 string; if REG_NOTEOL is set, then $ does not match at the end.
5526 We return 0 if we find a match and REG_NOMATCH if not. */
5528 int regexec (preg, string, nmatch, pmatch, eflags)
5529 const regex_t *preg;
5532 regmatch_t pmatch[];
5536 struct re_registers regs;
5537 regex_t private_preg;
5538 int len = strlen (string);
5539 boolean want_reg_info = !preg->no_sub && nmatch > 0;
5541 private_preg = *preg;
5543 private_preg.not_bol = !!(eflags & REG_NOTBOL);
5544 private_preg.not_eol = !!(eflags & REG_NOTEOL);
5546 /* The user has told us exactly how many registers to return
5547 information about, via `nmatch'. We have to pass that on to the
5548 matching routines. */
5549 private_preg.regs_allocated = REGS_FIXED;
5551 if (want_reg_info) {
5552 regs.num_regs = nmatch;
5553 regs.start = TALLOC (nmatch, regoff_t);
5554 regs.end = TALLOC (nmatch, regoff_t);
5555 if (regs.start == NULL || regs.end == NULL)
5556 return (int) REG_NOMATCH;
5559 /* Perform the searching operation. */
5560 ret = re_search (&private_preg, string, len,
5561 /* start: */ 0, /* range: */ len,
5562 want_reg_info ? ®s : (struct re_registers *) 0);
5564 /* Copy the register information to the POSIX structure. */
5565 if (want_reg_info) {
5569 for (r = 0; r < nmatch; r++) {
5570 pmatch[r].rm_so = regs.start[r];
5571 pmatch[r].rm_eo = regs.end[r];
5575 /* If we needed the temporary register info, free the space now. */
5576 free (regs.start); /* __MEM_CHECKED__ */
5577 free (regs.end); /* __MEM_CHECKED__ */
5580 /* We want zero return to mean success, unlike `re_search'. */
5581 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5585 /* Returns a message corresponding to an error code, ERRCODE, returned
5586 from either regcomp or regexec. We don't use PREG here. */
5588 size_t regerror (errcode, preg, errbuf, errbuf_size)
5590 const regex_t *preg;
5597 if (errcode < 0 || errcode >= (int) (sizeof (re_error_msgid)
5598 / sizeof (re_error_msgid[0])))
5599 /* Only error codes returned by the rest of the code should be passed
5600 to this routine. If we are given anything else, or if other regex
5601 code generates an invalid error code, then the program has a bug.
5602 Dump core so we can fix it. */
5605 msg = gettext (re_error_msgid[errcode]);
5607 msg_size = strlen (msg) + 1; /* Includes the null. */
5609 if (errbuf_size != 0) {
5610 if (msg_size > errbuf_size) {
5611 strncpy (errbuf, msg, errbuf_size - 1);
5612 errbuf[errbuf_size - 1] = 0;
5615 strcpy (errbuf, msg); /* __STRCPY_CHECKED__ */
5622 /* Free dynamically allocated space used by PREG. */
5627 if (preg->buffer != NULL)
5628 free (preg->buffer); /* __MEM_CHECKED__ */
5629 preg->buffer = NULL;
5631 preg->allocated = 0;
5634 if (preg->fastmap != NULL)
5635 free (preg->fastmap); /* __MEM_CHECKED__ */
5636 preg->fastmap = NULL;
5637 preg->fastmap_accurate = 0;
5639 if (preg->translate != NULL)
5640 free (preg->translate); /* __MEM_CHECKED__ */
5641 preg->translate = NULL;
5644 #endif /* not emacs */