1 /* Extended regular expression matching and search library,
3 (Implements POSIX draft P1003.2/D11.2, except for some of the
4 internationalization features.)
5 Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998
6 Free Software Foundation, Inc.
8 NOTE: The canonical source of this file is maintained with the
9 GNU C Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu.
11 This program is free software; you can redistribute it and/or modify it
12 under the terms of the GNU General Public License as published by the
13 Free Software Foundation; either version 2, or (at your option) any
16 This program 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
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software Foundation,
23 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
29 /* GCC LOCAL: we don't need NLS here. */
31 /* GCC LOCAL: to handle defining alloca. */
32 #include "libiberty.h"
34 /* Do not use a C alloca, we will leak memory and crash. */
39 /* AIX requires this to be the first thing in the file. */
40 #if defined _AIX && !defined REGEX_MALLOC
45 # if defined __GNUC__ || (defined __STDC__ && __STDC__)
46 # define PARAMS(args) args
48 # define PARAMS(args) ()
50 #endif /* Not PARAMS. */
52 #if defined STDC_HEADERS && !defined emacs
55 /* We need this for `gnu-regex.h', and perhaps for the Emacs include files. */
56 # include <sys/types.h>
59 /* For platform which support the ISO C amendement 1 functionality we
60 support user defined character classes. */
61 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
62 /* Solaris 2.5 has a bug: <wchar.h> must be included before <wctype.h>. */
67 /* This is for other GNU distributions with internationalized messages. */
68 /* GCC LOCAL: ../intl will handle this for us */
72 # define gettext(msgid) (msgid)
76 /* This define is so xgettext can find the internationalizable
78 # define gettext_noop(String) String
81 # if !defined(volatile) && !defined(HAVE_VOLATILE)
85 /* If we are not linking with Emacs proper,
86 we can't use the relocating allocator
87 even if config.h says that we can. */
90 # if defined STDC_HEADERS || defined _LIBC
97 /* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
98 If nothing else has been done, use the method below. */
99 # ifdef INHIBIT_STRING_HEADER
100 # if !(defined HAVE_BZERO && defined HAVE_BCOPY)
101 # if !defined bzero && !defined bcopy
102 # undef INHIBIT_STRING_HEADER
107 /* This is the normal way of making sure we have a bcopy and a bzero.
108 This is used in most programs--a few other programs avoid this
109 by defining INHIBIT_STRING_HEADER. */
110 # ifndef INHIBIT_STRING_HEADER
111 # if defined HAVE_STRING_H || defined STDC_HEADERS || defined _LIBC
115 # define bzero(s, n) (memset (s, '\0', n), (s))
117 # define bzero(s, n) __bzero (s, n)
121 # include <strings.h>
123 # define memcmp(s1, s2, n) bcmp (s1, s2, n)
126 # define memcpy(d, s, n) (bcopy (s, d, n), (d))
131 /* Define the syntax stuff for \<, \>, etc. */
133 /* This must be nonzero for the wordchar and notwordchar pattern
134 commands in re_match_2. */
139 # ifdef SWITCH_ENUM_BUG
140 # define SWITCH_ENUM_CAST(x) ((int)(x))
142 # define SWITCH_ENUM_CAST(x) (x)
145 /* How many characters in the character set. */
146 # define CHAR_SET_SIZE 256
150 extern char *re_syntax_table;
152 # else /* not SYNTAX_TABLE */
154 static char re_syntax_table[CHAR_SET_SIZE];
156 static void init_syntax_once PARAMS ((void));
167 bzero (re_syntax_table, sizeof re_syntax_table);
169 for (c = 'a'; c <= 'z'; c++)
170 re_syntax_table[c] = Sword;
172 for (c = 'A'; c <= 'Z'; c++)
173 re_syntax_table[c] = Sword;
175 for (c = '0'; c <= '9'; c++)
176 re_syntax_table[c] = Sword;
178 re_syntax_table['_'] = Sword;
183 # endif /* not SYNTAX_TABLE */
185 # define SYNTAX(c) re_syntax_table[c]
187 /* Get the interface, including the syntax bits. */
188 /* GCC LOCAL: call it gnu-regex.h, not regex.h, to avoid name conflicts */
189 #include "gnu-regex.h"
191 /* ISALPHA etc. are used for the character classes. */
192 /* GCC LOCAL: use libiberty's safe-ctype.h, don't bother defining
193 wrapper macros ourselves. */
194 #include <safe-ctype.h>
197 # define NULL (void *)0
200 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
201 since ours (we hope) works properly with all combinations of
202 machines, compilers, `char' and `unsigned char' argument types.
203 (Per Bothner suggested the basic approach.) */
204 #undef SIGN_EXTEND_CHAR
206 # define SIGN_EXTEND_CHAR(c) ((signed char) (c))
207 #else /* not __STDC__ */
208 /* As in Harbison and Steele. */
209 # define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
212 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
213 use `alloca' instead of `malloc'. This is because using malloc in
214 re_search* or re_match* could cause memory leaks when C-g is used in
215 Emacs; also, malloc is slower and causes storage fragmentation. On
216 the other hand, malloc is more portable, and easier to debug.
218 Because we sometimes use alloca, some routines have to be macros,
219 not functions -- `alloca'-allocated space disappears at the end of the
220 function it is called in. */
224 # define REGEX_ALLOCATE malloc
225 # define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
226 # define REGEX_FREE free
228 #else /* not REGEX_MALLOC */
230 /* Emacs already defines alloca, sometimes. */
233 /* Make alloca work the best possible way. */
235 # define alloca __builtin_alloca
236 # else /* not __GNUC__ */
239 # endif /* HAVE_ALLOCA_H */
240 # endif /* not __GNUC__ */
242 # endif /* not alloca */
244 # define REGEX_ALLOCATE alloca
246 /* Assumes a `char *destination' variable. */
247 # define REGEX_REALLOCATE(source, osize, nsize) \
248 (destination = (char *) alloca (nsize), \
249 memcpy (destination, source, osize))
251 /* No need to do anything to free, after alloca. */
252 # define REGEX_FREE(arg) ((void)0) /* Do nothing! But inhibit gcc warning. */
254 #endif /* not REGEX_MALLOC */
256 /* Define how to allocate the failure stack. */
258 #if defined REL_ALLOC && defined REGEX_MALLOC
260 # define REGEX_ALLOCATE_STACK(size) \
261 r_alloc (&failure_stack_ptr, (size))
262 # define REGEX_REALLOCATE_STACK(source, osize, nsize) \
263 r_re_alloc (&failure_stack_ptr, (nsize))
264 # define REGEX_FREE_STACK(ptr) \
265 r_alloc_free (&failure_stack_ptr)
267 #else /* not using relocating allocator */
271 # define REGEX_ALLOCATE_STACK malloc
272 # define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
273 # define REGEX_FREE_STACK free
275 # else /* not REGEX_MALLOC */
277 # define REGEX_ALLOCATE_STACK alloca
279 # define REGEX_REALLOCATE_STACK(source, osize, nsize) \
280 REGEX_REALLOCATE (source, osize, nsize)
281 /* No need to explicitly free anything. */
282 # define REGEX_FREE_STACK(arg)
284 # endif /* not REGEX_MALLOC */
285 #endif /* not using relocating allocator */
288 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
289 `string1' or just past its end. This works if PTR is NULL, which is
291 #define FIRST_STRING_P(ptr) \
292 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
294 /* (Re)Allocate N items of type T using malloc, or fail. */
295 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
296 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
297 #define RETALLOC_IF(addr, n, t) \
298 if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
299 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
301 #define BYTEWIDTH 8 /* In bits. */
303 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
307 #define MAX(a, b) ((a) > (b) ? (a) : (b))
308 #define MIN(a, b) ((a) < (b) ? (a) : (b))
310 typedef char boolean;
314 static int re_match_2_internal PARAMS ((struct re_pattern_buffer *bufp,
315 const char *string1, int size1,
316 const char *string2, int size2,
318 struct re_registers *regs,
321 /* These are the command codes that appear in compiled regular
322 expressions. Some opcodes are followed by argument bytes. A
323 command code can specify any interpretation whatsoever for its
324 arguments. Zero bytes may appear in the compiled regular expression. */
330 /* Succeed right away--no more backtracking. */
333 /* Followed by one byte giving n, then by n literal bytes. */
336 /* Matches any (more or less) character. */
339 /* Matches any one char belonging to specified set. First
340 following byte is number of bitmap bytes. Then come bytes
341 for a bitmap saying which chars are in. Bits in each byte
342 are ordered low-bit-first. A character is in the set if its
343 bit is 1. A character too large to have a bit in the map is
344 automatically not in the set. */
347 /* Same parameters as charset, but match any character that is
348 not one of those specified. */
351 /* Start remembering the text that is matched, for storing in a
352 register. Followed by one byte with the register number, in
353 the range 0 to one less than the pattern buffer's re_nsub
354 field. Then followed by one byte with the number of groups
355 inner to this one. (This last has to be part of the
356 start_memory only because we need it in the on_failure_jump
360 /* Stop remembering the text that is matched and store it in a
361 memory register. Followed by one byte with the register
362 number, in the range 0 to one less than `re_nsub' in the
363 pattern buffer, and one byte with the number of inner groups,
364 just like `start_memory'. (We need the number of inner
365 groups here because we don't have any easy way of finding the
366 corresponding start_memory when we're at a stop_memory.) */
369 /* Match a duplicate of something remembered. Followed by one
370 byte containing the register number. */
373 /* Fail unless at beginning of line. */
376 /* Fail unless at end of line. */
379 /* Succeeds if at beginning of buffer (if emacs) or at beginning
380 of string to be matched (if not). */
383 /* Analogously, for end of buffer/string. */
386 /* Followed by two byte relative address to which to jump. */
389 /* Same as jump, but marks the end of an alternative. */
392 /* Followed by two-byte relative address of place to resume at
393 in case of failure. */
396 /* Like on_failure_jump, but pushes a placeholder instead of the
397 current string position when executed. */
398 on_failure_keep_string_jump,
400 /* Throw away latest failure point and then jump to following
401 two-byte relative address. */
404 /* Change to pop_failure_jump if know won't have to backtrack to
405 match; otherwise change to jump. This is used to jump
406 back to the beginning of a repeat. If what follows this jump
407 clearly won't match what the repeat does, such that we can be
408 sure that there is no use backtracking out of repetitions
409 already matched, then we change it to a pop_failure_jump.
410 Followed by two-byte address. */
413 /* Jump to following two-byte address, and push a dummy failure
414 point. This failure point will be thrown away if an attempt
415 is made to use it for a failure. A `+' construct makes this
416 before the first repeat. Also used as an intermediary kind
417 of jump when compiling an alternative. */
420 /* Push a dummy failure point and continue. Used at the end of
424 /* Followed by two-byte relative address and two-byte number n.
425 After matching N times, jump to the address upon failure. */
428 /* Followed by two-byte relative address, and two-byte number n.
429 Jump to the address N times, then fail. */
432 /* Set the following two-byte relative address to the
433 subsequent two-byte number. The address *includes* the two
437 wordchar, /* Matches any word-constituent character. */
438 notwordchar, /* Matches any char that is not a word-constituent. */
440 wordbeg, /* Succeeds if at word beginning. */
441 wordend, /* Succeeds if at word end. */
443 wordbound, /* Succeeds if at a word boundary. */
444 notwordbound /* Succeeds if not at a word boundary. */
447 ,before_dot, /* Succeeds if before point. */
448 at_dot, /* Succeeds if at point. */
449 after_dot, /* Succeeds if after point. */
451 /* Matches any character whose syntax is specified. Followed by
452 a byte which contains a syntax code, e.g., Sword. */
455 /* Matches any character whose syntax is not that specified. */
460 /* Common operations on the compiled pattern. */
462 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
464 #define STORE_NUMBER(destination, number) \
466 (destination)[0] = (number) & 0377; \
467 (destination)[1] = (number) >> 8; \
470 /* Same as STORE_NUMBER, except increment DESTINATION to
471 the byte after where the number is stored. Therefore, DESTINATION
472 must be an lvalue. */
474 #define STORE_NUMBER_AND_INCR(destination, number) \
476 STORE_NUMBER (destination, number); \
477 (destination) += 2; \
480 /* Put into DESTINATION a number stored in two contiguous bytes starting
483 #define EXTRACT_NUMBER(destination, source) \
485 (destination) = *(source) & 0377; \
486 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
490 static void extract_number _RE_ARGS ((int *dest, unsigned char *source));
492 extract_number (dest, source)
494 unsigned char *source;
496 int temp = SIGN_EXTEND_CHAR (*(source + 1));
497 *dest = *source & 0377;
501 # ifndef EXTRACT_MACROS /* To debug the macros. */
502 # undef EXTRACT_NUMBER
503 # define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
504 # endif /* not EXTRACT_MACROS */
508 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
509 SOURCE must be an lvalue. */
511 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
513 EXTRACT_NUMBER (destination, source); \
518 static void extract_number_and_incr _RE_ARGS ((int *destination,
519 unsigned char **source));
521 extract_number_and_incr (destination, source)
523 unsigned char **source;
525 extract_number (destination, *source);
529 # ifndef EXTRACT_MACROS
530 # undef EXTRACT_NUMBER_AND_INCR
531 # define EXTRACT_NUMBER_AND_INCR(dest, src) \
532 extract_number_and_incr (&dest, &src)
533 # endif /* not EXTRACT_MACROS */
537 /* If DEBUG is defined, Regex prints many voluminous messages about what
538 it is doing (if the variable `debug' is nonzero). If linked with the
539 main program in `iregex.c', you can enter patterns and strings
540 interactively. And if linked with the main program in `main.c' and
541 the other test files, you can run the already-written tests. */
545 /* We use standard I/O for debugging. */
548 /* It is useful to test things that ``must'' be true when debugging. */
551 static int debug = 0;
553 # define DEBUG_STATEMENT(e) e
554 # define DEBUG_PRINT1(x) if (debug) printf (x)
555 # define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
556 # define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
557 # define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
558 # define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
559 if (debug) print_partial_compiled_pattern (s, e)
560 # define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
561 if (debug) print_double_string (w, s1, sz1, s2, sz2)
564 /* Print the fastmap in human-readable form. */
567 print_fastmap (fastmap)
570 unsigned was_a_range = 0;
573 while (i < (1 << BYTEWIDTH))
579 while (i < (1 << BYTEWIDTH) && fastmap[i])
595 /* Print a compiled pattern string in human-readable form, starting at
596 the START pointer into it and ending just before the pointer END. */
599 print_partial_compiled_pattern (start, end)
600 unsigned char *start;
605 unsigned char *p = start;
606 unsigned char *pend = end;
614 /* Loop over pattern commands. */
617 printf ("%d:\t", p - start);
619 switch ((re_opcode_t) *p++)
627 printf ("/exactn/%d", mcnt);
638 printf ("/start_memory/%d/%d", mcnt, *p++);
643 printf ("/stop_memory/%d/%d", mcnt, *p++);
647 printf ("/duplicate/%d", *p++);
657 register int c, last = -100;
658 register int in_range = 0;
660 printf ("/charset [%s",
661 (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
663 assert (p + *p < pend);
665 for (c = 0; c < 256; c++)
667 && (p[1 + (c/8)] & (1 << (c % 8))))
669 /* Are we starting a range? */
670 if (last + 1 == c && ! in_range)
675 /* Have we broken a range? */
676 else if (last + 1 != c && in_range)
705 case on_failure_jump:
706 extract_number_and_incr (&mcnt, &p);
707 printf ("/on_failure_jump to %d", p + mcnt - start);
710 case on_failure_keep_string_jump:
711 extract_number_and_incr (&mcnt, &p);
712 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
715 case dummy_failure_jump:
716 extract_number_and_incr (&mcnt, &p);
717 printf ("/dummy_failure_jump to %d", p + mcnt - start);
720 case push_dummy_failure:
721 printf ("/push_dummy_failure");
725 extract_number_and_incr (&mcnt, &p);
726 printf ("/maybe_pop_jump to %d", p + mcnt - start);
729 case pop_failure_jump:
730 extract_number_and_incr (&mcnt, &p);
731 printf ("/pop_failure_jump to %d", p + mcnt - start);
735 extract_number_and_incr (&mcnt, &p);
736 printf ("/jump_past_alt to %d", p + mcnt - start);
740 extract_number_and_incr (&mcnt, &p);
741 printf ("/jump to %d", p + mcnt - start);
745 extract_number_and_incr (&mcnt, &p);
747 extract_number_and_incr (&mcnt2, &p);
748 printf ("/succeed_n to %d, %d times", p1 - start, mcnt2);
752 extract_number_and_incr (&mcnt, &p);
754 extract_number_and_incr (&mcnt2, &p);
755 printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
759 extract_number_and_incr (&mcnt, &p);
761 extract_number_and_incr (&mcnt2, &p);
762 printf ("/set_number_at location %d to %d", p1 - start, mcnt2);
766 printf ("/wordbound");
770 printf ("/notwordbound");
782 printf ("/before_dot");
790 printf ("/after_dot");
794 printf ("/syntaxspec");
796 printf ("/%d", mcnt);
800 printf ("/notsyntaxspec");
802 printf ("/%d", mcnt);
807 printf ("/wordchar");
811 printf ("/notwordchar");
823 printf ("?%d", *(p-1));
829 printf ("%d:\tend of pattern.\n", p - start);
834 print_compiled_pattern (bufp)
835 struct re_pattern_buffer *bufp;
837 unsigned char *buffer = bufp->buffer;
839 print_partial_compiled_pattern (buffer, buffer + bufp->used);
840 printf ("%ld bytes used/%ld bytes allocated.\n",
841 bufp->used, bufp->allocated);
843 if (bufp->fastmap_accurate && bufp->fastmap)
845 printf ("fastmap: ");
846 print_fastmap (bufp->fastmap);
849 printf ("re_nsub: %d\t", bufp->re_nsub);
850 printf ("regs_alloc: %d\t", bufp->regs_allocated);
851 printf ("can_be_null: %d\t", bufp->can_be_null);
852 printf ("newline_anchor: %d\n", bufp->newline_anchor);
853 printf ("no_sub: %d\t", bufp->no_sub);
854 printf ("not_bol: %d\t", bufp->not_bol);
855 printf ("not_eol: %d\t", bufp->not_eol);
856 printf ("syntax: %lx\n", bufp->syntax);
857 /* Perhaps we should print the translate table? */
862 print_double_string (where, string1, size1, string2, size2)
875 if (FIRST_STRING_P (where))
877 for (this_char = where - string1; this_char < size1; this_char++)
878 putchar (string1[this_char]);
883 for (this_char = where - string2; this_char < size2; this_char++)
884 putchar (string2[this_char]);
895 #else /* not DEBUG */
900 # define DEBUG_STATEMENT(e)
901 # define DEBUG_PRINT1(x)
902 # define DEBUG_PRINT2(x1, x2)
903 # define DEBUG_PRINT3(x1, x2, x3)
904 # define DEBUG_PRINT4(x1, x2, x3, x4)
905 # define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
906 # define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
908 #endif /* not DEBUG */
910 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
911 also be assigned to arbitrarily: each pattern buffer stores its own
912 syntax, so it can be changed between regex compilations. */
913 /* This has no initializer because initialized variables in Emacs
914 become read-only after dumping. */
915 reg_syntax_t re_syntax_options;
918 /* Specify the precise syntax of regexps for compilation. This provides
919 for compatibility for various utilities which historically have
920 different, incompatible syntaxes.
922 The argument SYNTAX is a bit mask comprised of the various bits
923 defined in gnu-regex.h. We return the old syntax. */
926 re_set_syntax (syntax)
929 reg_syntax_t ret = re_syntax_options;
931 re_syntax_options = syntax;
933 if (syntax & RE_DEBUG)
935 else if (debug) /* was on but now is not */
941 weak_alias (__re_set_syntax, re_set_syntax)
944 /* This table gives an error message for each of the error codes listed
945 in gnu-regex.h. Obviously the order here has to be same as there.
946 POSIX doesn't require that we do anything for REG_NOERROR,
947 but why not be nice? */
949 static const char *const re_error_msgid[] =
951 gettext_noop ("Success"), /* REG_NOERROR */
952 gettext_noop ("No match"), /* REG_NOMATCH */
953 gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
954 gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
955 gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
956 gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
957 gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
958 gettext_noop ("Unmatched [ or [^"), /* REG_EBRACK */
959 gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
960 gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
961 gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
962 gettext_noop ("Invalid range end"), /* REG_ERANGE */
963 gettext_noop ("Memory exhausted"), /* REG_ESPACE */
964 gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
965 gettext_noop ("Premature end of regular expression"), /* REG_EEND */
966 gettext_noop ("Regular expression too big"), /* REG_ESIZE */
967 gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
970 /* Avoiding alloca during matching, to placate r_alloc. */
972 /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
973 searching and matching functions should not call alloca. On some
974 systems, alloca is implemented in terms of malloc, and if we're
975 using the relocating allocator routines, then malloc could cause a
976 relocation, which might (if the strings being searched are in the
977 ralloc heap) shift the data out from underneath the regexp
980 Here's another reason to avoid allocation: Emacs
981 processes input from X in a signal handler; processing X input may
982 call malloc; if input arrives while a matching routine is calling
983 malloc, then we're scrod. But Emacs can't just block input while
984 calling matching routines; then we don't notice interrupts when
985 they come in. So, Emacs blocks input around all regexp calls
986 except the matching calls, which it leaves unprotected, in the
987 faith that they will not malloc. */
989 /* Normally, this is fine. */
990 #define MATCH_MAY_ALLOCATE
992 /* When using GNU C, we are not REALLY using the C alloca, no matter
993 what config.h may say. So don't take precautions for it. */
998 /* The match routines may not allocate if (1) they would do it with malloc
999 and (2) it's not safe for them to use malloc.
1000 Note that if REL_ALLOC is defined, matching would not use malloc for the
1001 failure stack, but we would still use it for the register vectors;
1002 so REL_ALLOC should not affect this. */
1003 #if (defined C_ALLOCA || defined REGEX_MALLOC) && defined emacs
1004 # undef MATCH_MAY_ALLOCATE
1008 /* Failure stack declarations and macros; both re_compile_fastmap and
1009 re_match_2 use a failure stack. These have to be macros because of
1010 REGEX_ALLOCATE_STACK. */
1013 /* Number of failure points for which to initially allocate space
1014 when matching. If this number is exceeded, we allocate more
1015 space, so it is not a hard limit. */
1016 #ifndef INIT_FAILURE_ALLOC
1017 # define INIT_FAILURE_ALLOC 5
1020 /* Roughly the maximum number of failure points on the stack. Would be
1021 exactly that if always used MAX_FAILURE_ITEMS items each time we failed.
1022 This is a variable only so users of regex can assign to it; we never
1023 change it ourselves. */
1027 # if defined MATCH_MAY_ALLOCATE
1028 /* 4400 was enough to cause a crash on Alpha OSF/1,
1029 whose default stack limit is 2mb. */
1030 long int re_max_failures = 4000;
1032 long int re_max_failures = 2000;
1035 union fail_stack_elt
1037 unsigned char *pointer;
1041 typedef union fail_stack_elt fail_stack_elt_t;
1045 fail_stack_elt_t *stack;
1046 unsigned long int size;
1047 unsigned long int avail; /* Offset of next open position. */
1050 #else /* not INT_IS_16BIT */
1052 # if defined MATCH_MAY_ALLOCATE
1053 /* 4400 was enough to cause a crash on Alpha OSF/1,
1054 whose default stack limit is 2mb. */
1055 int re_max_failures = 20000;
1057 int re_max_failures = 2000;
1060 union fail_stack_elt
1062 unsigned char *pointer;
1066 typedef union fail_stack_elt fail_stack_elt_t;
1070 fail_stack_elt_t *stack;
1072 unsigned avail; /* Offset of next open position. */
1075 #endif /* INT_IS_16BIT */
1077 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
1078 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
1079 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
1082 /* Define macros to initialize and free the failure stack.
1083 Do `return -2' if the alloc fails. */
1085 #ifdef MATCH_MAY_ALLOCATE
1086 # define INIT_FAIL_STACK() \
1088 fail_stack.stack = (fail_stack_elt_t *) \
1089 REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
1091 if (fail_stack.stack == NULL) \
1094 fail_stack.size = INIT_FAILURE_ALLOC; \
1095 fail_stack.avail = 0; \
1098 # define RESET_FAIL_STACK() REGEX_FREE_STACK (fail_stack.stack)
1100 # define INIT_FAIL_STACK() \
1102 fail_stack.avail = 0; \
1105 # define RESET_FAIL_STACK()
1109 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
1111 Return 1 if succeeds, and 0 if either ran out of memory
1112 allocating space for it or it was already too large.
1114 REGEX_REALLOCATE_STACK requires `destination' be declared. */
1116 #define DOUBLE_FAIL_STACK(fail_stack) \
1117 ((fail_stack).size > (unsigned) (re_max_failures * MAX_FAILURE_ITEMS) \
1119 : ((fail_stack).stack = (fail_stack_elt_t *) \
1120 REGEX_REALLOCATE_STACK ((fail_stack).stack, \
1121 (fail_stack).size * sizeof (fail_stack_elt_t), \
1122 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
1124 (fail_stack).stack == NULL \
1126 : ((fail_stack).size <<= 1, \
1130 /* Push pointer POINTER on FAIL_STACK.
1131 Return 1 if was able to do so and 0 if ran out of memory allocating
1133 #define PUSH_PATTERN_OP(POINTER, FAIL_STACK) \
1134 ((FAIL_STACK_FULL () \
1135 && !DOUBLE_FAIL_STACK (FAIL_STACK)) \
1137 : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER, \
1140 /* Push a pointer value onto the failure stack.
1141 Assumes the variable `fail_stack'. Probably should only
1142 be called from within `PUSH_FAILURE_POINT'. */
1143 #define PUSH_FAILURE_POINTER(item) \
1144 fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
1146 /* This pushes an integer-valued item onto the failure stack.
1147 Assumes the variable `fail_stack'. Probably should only
1148 be called from within `PUSH_FAILURE_POINT'. */
1149 #define PUSH_FAILURE_INT(item) \
1150 fail_stack.stack[fail_stack.avail++].integer = (item)
1152 /* Push a fail_stack_elt_t value onto the failure stack.
1153 Assumes the variable `fail_stack'. Probably should only
1154 be called from within `PUSH_FAILURE_POINT'. */
1155 #define PUSH_FAILURE_ELT(item) \
1156 fail_stack.stack[fail_stack.avail++] = (item)
1158 /* These three POP... operations complement the three PUSH... operations.
1159 All assume that `fail_stack' is nonempty. */
1160 #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
1161 #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
1162 #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
1164 /* Used to omit pushing failure point id's when we're not debugging. */
1166 # define DEBUG_PUSH PUSH_FAILURE_INT
1167 # define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT ()
1169 # define DEBUG_PUSH(item)
1170 # define DEBUG_POP(item_addr)
1174 /* Push the information about the state we will need
1175 if we ever fail back to it.
1177 Requires variables fail_stack, regstart, regend, reg_info, and
1178 num_regs_pushed be declared. DOUBLE_FAIL_STACK requires `destination'
1181 Does `return FAILURE_CODE' if runs out of memory. */
1183 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1185 char *destination; \
1186 /* Must be int, so when we don't save any registers, the arithmetic \
1187 of 0 + -1 isn't done as unsigned. */ \
1188 /* Can't be int, since there is not a shred of a guarantee that int \
1189 is wide enough to hold a value of something to which pointer can \
1191 active_reg_t this_reg; \
1193 DEBUG_STATEMENT (failure_id++); \
1194 DEBUG_STATEMENT (nfailure_points_pushed++); \
1195 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1196 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1197 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1199 DEBUG_PRINT2 (" slots needed: %ld\n", NUM_FAILURE_ITEMS); \
1200 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1202 /* Ensure we have enough space allocated for what we will push. */ \
1203 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1205 if (!DOUBLE_FAIL_STACK (fail_stack)) \
1206 return failure_code; \
1208 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1209 (fail_stack).size); \
1210 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1213 /* Push the info, starting with the registers. */ \
1214 DEBUG_PRINT1 ("\n"); \
1217 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
1220 DEBUG_PRINT2 (" Pushing reg: %lu\n", this_reg); \
1221 DEBUG_STATEMENT (num_regs_pushed++); \
1223 DEBUG_PRINT2 (" start: %p\n", regstart[this_reg]); \
1224 PUSH_FAILURE_POINTER (regstart[this_reg]); \
1226 DEBUG_PRINT2 (" end: %p\n", regend[this_reg]); \
1227 PUSH_FAILURE_POINTER (regend[this_reg]); \
1229 DEBUG_PRINT2 (" info: %p\n ", \
1230 reg_info[this_reg].word.pointer); \
1231 DEBUG_PRINT2 (" match_null=%d", \
1232 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1233 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1234 DEBUG_PRINT2 (" matched_something=%d", \
1235 MATCHED_SOMETHING (reg_info[this_reg])); \
1236 DEBUG_PRINT2 (" ever_matched=%d", \
1237 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1238 DEBUG_PRINT1 ("\n"); \
1239 PUSH_FAILURE_ELT (reg_info[this_reg].word); \
1242 DEBUG_PRINT2 (" Pushing low active reg: %ld\n", lowest_active_reg);\
1243 PUSH_FAILURE_INT (lowest_active_reg); \
1245 DEBUG_PRINT2 (" Pushing high active reg: %ld\n", highest_active_reg);\
1246 PUSH_FAILURE_INT (highest_active_reg); \
1248 DEBUG_PRINT2 (" Pushing pattern %p:\n", pattern_place); \
1249 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1250 PUSH_FAILURE_POINTER (pattern_place); \
1252 DEBUG_PRINT2 (" Pushing string %p: `", string_place); \
1253 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1255 DEBUG_PRINT1 ("'\n"); \
1256 PUSH_FAILURE_POINTER (string_place); \
1258 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1259 DEBUG_PUSH (failure_id); \
1262 /* This is the number of items that are pushed and popped on the stack
1263 for each register. */
1264 #define NUM_REG_ITEMS 3
1266 /* Individual items aside from the registers. */
1268 # define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1270 # define NUM_NONREG_ITEMS 4
1273 /* We push at most this many items on the stack. */
1274 /* We used to use (num_regs - 1), which is the number of registers
1275 this regexp will save; but that was changed to 5
1276 to avoid stack overflow for a regexp with lots of parens. */
1277 #define MAX_FAILURE_ITEMS (5 * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1279 /* We actually push this many items. */
1280 #define NUM_FAILURE_ITEMS \
1282 ? 0 : highest_active_reg - lowest_active_reg + 1) \
1286 /* How many items can still be added to the stack without overflowing it. */
1287 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1290 /* Pops what PUSH_FAIL_STACK pushes.
1292 We restore into the parameters, all of which should be lvalues:
1293 STR -- the saved data position.
1294 PAT -- the saved pattern position.
1295 LOW_REG, HIGH_REG -- the highest and lowest active registers.
1296 REGSTART, REGEND -- arrays of string positions.
1297 REG_INFO -- array of information about each subexpression.
1299 Also assumes the variables `fail_stack' and (if debugging), `bufp',
1300 `pend', `string1', `size1', `string2', and `size2'. */
1302 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1304 DEBUG_STATEMENT (unsigned failure_id;) \
1305 active_reg_t this_reg; \
1306 const unsigned char *string_temp; \
1308 assert (!FAIL_STACK_EMPTY ()); \
1310 /* Remove failure points and point to how many regs pushed. */ \
1311 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1312 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1313 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1315 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1317 DEBUG_POP (&failure_id); \
1318 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1320 /* If the saved string location is NULL, it came from an \
1321 on_failure_keep_string_jump opcode, and we want to throw away the \
1322 saved NULL, thus retaining our current position in the string. */ \
1323 string_temp = POP_FAILURE_POINTER (); \
1324 if (string_temp != NULL) \
1325 str = (const char *) string_temp; \
1327 DEBUG_PRINT2 (" Popping string %p: `", str); \
1328 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1329 DEBUG_PRINT1 ("'\n"); \
1331 pat = (unsigned char *) POP_FAILURE_POINTER (); \
1332 DEBUG_PRINT2 (" Popping pattern %p:\n", pat); \
1333 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1335 /* Restore register info. */ \
1336 high_reg = (active_reg_t) POP_FAILURE_INT (); \
1337 DEBUG_PRINT2 (" Popping high active reg: %ld\n", high_reg); \
1339 low_reg = (active_reg_t) POP_FAILURE_INT (); \
1340 DEBUG_PRINT2 (" Popping low active reg: %ld\n", low_reg); \
1343 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
1345 DEBUG_PRINT2 (" Popping reg: %ld\n", this_reg); \
1347 reg_info[this_reg].word = POP_FAILURE_ELT (); \
1348 DEBUG_PRINT2 (" info: %p\n", \
1349 reg_info[this_reg].word.pointer); \
1351 regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1352 DEBUG_PRINT2 (" end: %p\n", regend[this_reg]); \
1354 regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1355 DEBUG_PRINT2 (" start: %p\n", regstart[this_reg]); \
1359 for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \
1361 reg_info[this_reg].word.integer = 0; \
1362 regend[this_reg] = 0; \
1363 regstart[this_reg] = 0; \
1365 highest_active_reg = high_reg; \
1368 set_regs_matched_done = 0; \
1369 DEBUG_STATEMENT (nfailure_points_popped++); \
1370 } /* POP_FAILURE_POINT */
1374 /* Structure for per-register (a.k.a. per-group) information.
1375 Other register information, such as the
1376 starting and ending positions (which are addresses), and the list of
1377 inner groups (which is a bits list) are maintained in separate
1380 We are making a (strictly speaking) nonportable assumption here: that
1381 the compiler will pack our bit fields into something that fits into
1382 the type of `word', i.e., is something that fits into one item on the
1386 /* Declarations and macros for re_match_2. */
1390 fail_stack_elt_t word;
1393 /* This field is one if this group can match the empty string,
1394 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1395 #define MATCH_NULL_UNSET_VALUE 3
1396 unsigned match_null_string_p : 2;
1397 unsigned is_active : 1;
1398 unsigned matched_something : 1;
1399 unsigned ever_matched_something : 1;
1401 } register_info_type;
1403 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1404 #define IS_ACTIVE(R) ((R).bits.is_active)
1405 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1406 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1409 /* Call this when have matched a real character; it sets `matched' flags
1410 for the subexpressions which we are currently inside. Also records
1411 that those subexprs have matched. */
1412 #define SET_REGS_MATCHED() \
1415 if (!set_regs_matched_done) \
1418 set_regs_matched_done = 1; \
1419 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1421 MATCHED_SOMETHING (reg_info[r]) \
1422 = EVER_MATCHED_SOMETHING (reg_info[r]) \
1429 /* Registers are set to a sentinel when they haven't yet matched. */
1430 static char reg_unset_dummy;
1431 #define REG_UNSET_VALUE (®_unset_dummy)
1432 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1434 /* Subroutine declarations and macros for regex_compile. */
1436 static reg_errcode_t regex_compile _RE_ARGS ((const char *pattern, size_t size,
1437 reg_syntax_t syntax,
1438 struct re_pattern_buffer *bufp));
1439 static void store_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg));
1440 static void store_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1441 int arg1, int arg2));
1442 static void insert_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1443 int arg, unsigned char *end));
1444 static void insert_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
1445 int arg1, int arg2, unsigned char *end));
1446 static boolean at_begline_loc_p _RE_ARGS ((const char *pattern, const char *p,
1447 reg_syntax_t syntax));
1448 static boolean at_endline_loc_p _RE_ARGS ((const char *p, const char *pend,
1449 reg_syntax_t syntax));
1450 static reg_errcode_t compile_range _RE_ARGS ((const char **p_ptr,
1453 reg_syntax_t syntax,
1456 /* Fetch the next character in the uncompiled pattern---translating it
1457 if necessary. Also cast from a signed character in the constant
1458 string passed to us by the user to an unsigned char that we can use
1459 as an array index (in, e.g., `translate'). */
1461 # define PATFETCH(c) \
1462 do {if (p == pend) return REG_EEND; \
1463 c = (unsigned char) *p++; \
1464 if (translate) c = (unsigned char) translate[c]; \
1468 /* Fetch the next character in the uncompiled pattern, with no
1470 #define PATFETCH_RAW(c) \
1471 do {if (p == pend) return REG_EEND; \
1472 c = (unsigned char) *p++; \
1475 /* Go backwards one character in the pattern. */
1476 #define PATUNFETCH p--
1479 /* If `translate' is non-null, return translate[D], else just D. We
1480 cast the subscript to translate because some data is declared as
1481 `char *', to avoid warnings when a string constant is passed. But
1482 when we use a character as a subscript we must make it unsigned. */
1484 # define TRANSLATE(d) \
1485 (translate ? (char) translate[(unsigned char) (d)] : (d))
1489 /* Macros for outputting the compiled pattern into `buffer'. */
1491 /* If the buffer isn't allocated when it comes in, use this. */
1492 #define INIT_BUF_SIZE 32
1494 /* Make sure we have at least N more bytes of space in buffer. */
1495 #define GET_BUFFER_SPACE(n) \
1496 while ((unsigned long) (b - bufp->buffer + (n)) > bufp->allocated) \
1499 /* Make sure we have one more byte of buffer space and then add C to it. */
1500 #define BUF_PUSH(c) \
1502 GET_BUFFER_SPACE (1); \
1503 *b++ = (unsigned char) (c); \
1507 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1508 #define BUF_PUSH_2(c1, c2) \
1510 GET_BUFFER_SPACE (2); \
1511 *b++ = (unsigned char) (c1); \
1512 *b++ = (unsigned char) (c2); \
1516 /* As with BUF_PUSH_2, except for three bytes. */
1517 #define BUF_PUSH_3(c1, c2, c3) \
1519 GET_BUFFER_SPACE (3); \
1520 *b++ = (unsigned char) (c1); \
1521 *b++ = (unsigned char) (c2); \
1522 *b++ = (unsigned char) (c3); \
1526 /* Store a jump with opcode OP at LOC to location TO. We store a
1527 relative address offset by the three bytes the jump itself occupies. */
1528 #define STORE_JUMP(op, loc, to) \
1529 store_op1 (op, loc, (int) ((to) - (loc) - 3))
1531 /* Likewise, for a two-argument jump. */
1532 #define STORE_JUMP2(op, loc, to, arg) \
1533 store_op2 (op, loc, (int) ((to) - (loc) - 3), arg)
1535 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1536 #define INSERT_JUMP(op, loc, to) \
1537 insert_op1 (op, loc, (int) ((to) - (loc) - 3), b)
1539 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1540 #define INSERT_JUMP2(op, loc, to, arg) \
1541 insert_op2 (op, loc, (int) ((to) - (loc) - 3), arg, b)
1544 /* This is not an arbitrary limit: the arguments which represent offsets
1545 into the pattern are two bytes long. So if 2^16 bytes turns out to
1546 be too small, many things would have to change. */
1547 /* Any other compiler which, like MSC, has allocation limit below 2^16
1548 bytes will have to use approach similar to what was done below for
1549 MSC and drop MAX_BUF_SIZE a bit. Otherwise you may end up
1550 reallocating to 0 bytes. Such thing is not going to work too well.
1551 You have been warned!! */
1552 #if defined _MSC_VER && !defined WIN32
1553 /* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
1554 The REALLOC define eliminates a flurry of conversion warnings,
1555 but is not required. */
1556 # define MAX_BUF_SIZE 65500L
1557 # define REALLOC(p,s) realloc ((p), (size_t) (s))
1559 # define MAX_BUF_SIZE (1L << 16)
1560 # define REALLOC(p,s) realloc ((p), (s))
1563 /* Extend the buffer by twice its current size via realloc and
1564 reset the pointers that pointed into the old block to point to the
1565 correct places in the new one. If extending the buffer results in it
1566 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1567 #define EXTEND_BUFFER() \
1569 unsigned char *old_buffer = bufp->buffer; \
1570 if (bufp->allocated == MAX_BUF_SIZE) \
1572 bufp->allocated <<= 1; \
1573 if (bufp->allocated > MAX_BUF_SIZE) \
1574 bufp->allocated = MAX_BUF_SIZE; \
1575 bufp->buffer = (unsigned char *) REALLOC (bufp->buffer, bufp->allocated);\
1576 if (bufp->buffer == NULL) \
1577 return REG_ESPACE; \
1578 /* If the buffer moved, move all the pointers into it. */ \
1579 if (old_buffer != bufp->buffer) \
1581 b = (b - old_buffer) + bufp->buffer; \
1582 begalt = (begalt - old_buffer) + bufp->buffer; \
1583 if (fixup_alt_jump) \
1584 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1586 laststart = (laststart - old_buffer) + bufp->buffer; \
1587 if (pending_exact) \
1588 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1593 /* Since we have one byte reserved for the register number argument to
1594 {start,stop}_memory, the maximum number of groups we can report
1595 things about is what fits in that byte. */
1596 #define MAX_REGNUM 255
1598 /* But patterns can have more than `MAX_REGNUM' registers. We just
1599 ignore the excess. */
1600 typedef unsigned regnum_t;
1603 /* Macros for the compile stack. */
1605 /* Since offsets can go either forwards or backwards, this type needs to
1606 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1607 /* int may be not enough when sizeof(int) == 2. */
1608 typedef long pattern_offset_t;
1612 pattern_offset_t begalt_offset;
1613 pattern_offset_t fixup_alt_jump;
1614 pattern_offset_t inner_group_offset;
1615 pattern_offset_t laststart_offset;
1617 } compile_stack_elt_t;
1622 compile_stack_elt_t *stack;
1624 unsigned avail; /* Offset of next open position. */
1625 } compile_stack_type;
1628 #define INIT_COMPILE_STACK_SIZE 32
1630 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1631 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1633 /* The next available element. */
1634 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1637 /* Set the bit for character C in a list. */
1638 #define SET_LIST_BIT(c) \
1639 (b[((unsigned char) (c)) / BYTEWIDTH] \
1640 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1643 /* Get the next unsigned number in the uncompiled pattern. */
1644 #define GET_UNSIGNED_NUMBER(num) \
1648 while (ISDIGIT (c)) \
1652 num = num * 10 + c - '0'; \
1660 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
1661 /* The GNU C library provides support for user-defined character classes
1662 and the functions from ISO C amendement 1. */
1663 # ifdef CHARCLASS_NAME_MAX
1664 # define CHAR_CLASS_MAX_LENGTH CHARCLASS_NAME_MAX
1666 /* This shouldn't happen but some implementation might still have this
1667 problem. Use a reasonable default value. */
1668 # define CHAR_CLASS_MAX_LENGTH 256
1672 # define IS_CHAR_CLASS(string) __wctype (string)
1674 # define IS_CHAR_CLASS(string) wctype (string)
1677 # define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1679 # define IS_CHAR_CLASS(string) \
1680 (STREQ (string, "alpha") || STREQ (string, "upper") \
1681 || STREQ (string, "lower") || STREQ (string, "digit") \
1682 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1683 || STREQ (string, "space") || STREQ (string, "print") \
1684 || STREQ (string, "punct") || STREQ (string, "graph") \
1685 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1688 #ifndef MATCH_MAY_ALLOCATE
1690 /* If we cannot allocate large objects within re_match_2_internal,
1691 we make the fail stack and register vectors global.
1692 The fail stack, we grow to the maximum size when a regexp
1694 The register vectors, we adjust in size each time we
1695 compile a regexp, according to the number of registers it needs. */
1697 static fail_stack_type fail_stack;
1699 /* Size with which the following vectors are currently allocated.
1700 That is so we can make them bigger as needed,
1701 but never make them smaller. */
1702 static int regs_allocated_size;
1704 static const char ** regstart, ** regend;
1705 static const char ** old_regstart, ** old_regend;
1706 static const char **best_regstart, **best_regend;
1707 static register_info_type *reg_info;
1708 static const char **reg_dummy;
1709 static register_info_type *reg_info_dummy;
1711 /* Make the register vectors big enough for NUM_REGS registers,
1712 but don't make them smaller. */
1715 regex_grow_registers (num_regs)
1718 if (num_regs > regs_allocated_size)
1720 RETALLOC_IF (regstart, num_regs, const char *);
1721 RETALLOC_IF (regend, num_regs, const char *);
1722 RETALLOC_IF (old_regstart, num_regs, const char *);
1723 RETALLOC_IF (old_regend, num_regs, const char *);
1724 RETALLOC_IF (best_regstart, num_regs, const char *);
1725 RETALLOC_IF (best_regend, num_regs, const char *);
1726 RETALLOC_IF (reg_info, num_regs, register_info_type);
1727 RETALLOC_IF (reg_dummy, num_regs, const char *);
1728 RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
1730 regs_allocated_size = num_regs;
1734 #endif /* not MATCH_MAY_ALLOCATE */
1736 static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
1740 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1741 Returns one of error codes defined in `gnu-regex.h', or zero for success.
1743 Assumes the `allocated' (and perhaps `buffer') and `translate'
1744 fields are set in BUFP on entry.
1746 If it succeeds, results are put in BUFP (if it returns an error, the
1747 contents of BUFP are undefined):
1748 `buffer' is the compiled pattern;
1749 `syntax' is set to SYNTAX;
1750 `used' is set to the length of the compiled pattern;
1751 `fastmap_accurate' is zero;
1752 `re_nsub' is the number of subexpressions in PATTERN;
1753 `not_bol' and `not_eol' are zero;
1755 The `fastmap' and `newline_anchor' fields are neither
1756 examined nor set. */
1758 /* Return, freeing storage we allocated. */
1759 #define FREE_STACK_RETURN(value) \
1760 return (free (compile_stack.stack), value)
1762 static reg_errcode_t
1763 regex_compile (pattern, size, syntax, bufp)
1764 const char *pattern;
1766 reg_syntax_t syntax;
1767 struct re_pattern_buffer *bufp;
1769 /* We fetch characters from PATTERN here. Even though PATTERN is
1770 `char *' (i.e., signed), we declare these variables as unsigned, so
1771 they can be reliably used as array indices. */
1772 register unsigned char c, c1;
1774 /* A random temporary spot in PATTERN. */
1777 /* Points to the end of the buffer, where we should append. */
1778 register unsigned char *b;
1780 /* Keeps track of unclosed groups. */
1781 compile_stack_type compile_stack;
1783 /* Points to the current (ending) position in the pattern. */
1784 const char *p = pattern;
1785 const char *pend = pattern + size;
1787 /* How to translate the characters in the pattern. */
1788 RE_TRANSLATE_TYPE translate = bufp->translate;
1790 /* Address of the count-byte of the most recently inserted `exactn'
1791 command. This makes it possible to tell if a new exact-match
1792 character can be added to that command or if the character requires
1793 a new `exactn' command. */
1794 unsigned char *pending_exact = 0;
1796 /* Address of start of the most recently finished expression.
1797 This tells, e.g., postfix * where to find the start of its
1798 operand. Reset at the beginning of groups and alternatives. */
1799 unsigned char *laststart = 0;
1801 /* Address of beginning of regexp, or inside of last group. */
1802 unsigned char *begalt;
1804 /* Place in the uncompiled pattern (i.e., the {) to
1805 which to go back if the interval is invalid. */
1806 const char *beg_interval;
1808 /* Address of the place where a forward jump should go to the end of
1809 the containing expression. Each alternative of an `or' -- except the
1810 last -- ends with a forward jump of this sort. */
1811 unsigned char *fixup_alt_jump = 0;
1813 /* Counts open-groups as they are encountered. Remembered for the
1814 matching close-group on the compile stack, so the same register
1815 number is put in the stop_memory as the start_memory. */
1816 regnum_t regnum = 0;
1819 DEBUG_PRINT1 ("\nCompiling pattern: ");
1822 unsigned debug_count;
1824 for (debug_count = 0; debug_count < size; debug_count++)
1825 putchar (pattern[debug_count]);
1830 /* Initialize the compile stack. */
1831 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1832 if (compile_stack.stack == NULL)
1835 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1836 compile_stack.avail = 0;
1838 /* Initialize the pattern buffer. */
1839 bufp->syntax = syntax;
1840 bufp->fastmap_accurate = 0;
1841 bufp->not_bol = bufp->not_eol = 0;
1843 /* Set `used' to zero, so that if we return an error, the pattern
1844 printer (for debugging) will think there's no pattern. We reset it
1848 /* Always count groups, whether or not bufp->no_sub is set. */
1851 #if !defined emacs && !defined SYNTAX_TABLE
1852 /* Initialize the syntax table. */
1853 init_syntax_once ();
1856 if (bufp->allocated == 0)
1859 { /* If zero allocated, but buffer is non-null, try to realloc
1860 enough space. This loses if buffer's address is bogus, but
1861 that is the user's responsibility. */
1862 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1865 { /* Caller did not allocate a buffer. Do it for them. */
1866 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1868 if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
1870 bufp->allocated = INIT_BUF_SIZE;
1873 begalt = b = bufp->buffer;
1875 /* Loop through the uncompiled pattern until we're at the end. */
1884 if ( /* If at start of pattern, it's an operator. */
1886 /* If context independent, it's an operator. */
1887 || syntax & RE_CONTEXT_INDEP_ANCHORS
1888 /* Otherwise, depends on what's come before. */
1889 || at_begline_loc_p (pattern, p, syntax))
1899 if ( /* If at end of pattern, it's an operator. */
1901 /* If context independent, it's an operator. */
1902 || syntax & RE_CONTEXT_INDEP_ANCHORS
1903 /* Otherwise, depends on what's next. */
1904 || at_endline_loc_p (p, pend, syntax))
1914 if ((syntax & RE_BK_PLUS_QM)
1915 || (syntax & RE_LIMITED_OPS))
1919 /* If there is no previous pattern... */
1922 if (syntax & RE_CONTEXT_INVALID_OPS)
1923 FREE_STACK_RETURN (REG_BADRPT);
1924 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1929 /* Are we optimizing this jump? */
1930 boolean keep_string_p = false;
1932 /* 1 means zero (many) matches is allowed. */
1933 char zero_times_ok = 0, many_times_ok = 0;
1935 /* If there is a sequence of repetition chars, collapse it
1936 down to just one (the right one). We can't combine
1937 interval operators with these because of, e.g., `a{2}*',
1938 which should only match an even number of `a's. */
1942 zero_times_ok |= c != '+';
1943 many_times_ok |= c != '?';
1951 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1954 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1956 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1959 if (!(c1 == '+' || c1 == '?'))
1974 /* If we get here, we found another repeat character. */
1977 /* Star, etc. applied to an empty pattern is equivalent
1978 to an empty pattern. */
1982 /* Now we know whether or not zero matches is allowed
1983 and also whether or not two or more matches is allowed. */
1985 { /* More than one repetition is allowed, so put in at the
1986 end a backward relative jump from `b' to before the next
1987 jump we're going to put in below (which jumps from
1988 laststart to after this jump).
1990 But if we are at the `*' in the exact sequence `.*\n',
1991 insert an unconditional jump backwards to the .,
1992 instead of the beginning of the loop. This way we only
1993 push a failure point once, instead of every time
1994 through the loop. */
1995 assert (p - 1 > pattern);
1997 /* Allocate the space for the jump. */
1998 GET_BUFFER_SPACE (3);
2000 /* We know we are not at the first character of the pattern,
2001 because laststart was nonzero. And we've already
2002 incremented `p', by the way, to be the character after
2003 the `*'. Do we have to do something analogous here
2004 for null bytes, because of RE_DOT_NOT_NULL? */
2005 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
2007 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
2008 && !(syntax & RE_DOT_NEWLINE))
2009 { /* We have .*\n. */
2010 STORE_JUMP (jump, b, laststart);
2011 keep_string_p = true;
2014 /* Anything else. */
2015 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
2017 /* We've added more stuff to the buffer. */
2021 /* On failure, jump from laststart to b + 3, which will be the
2022 end of the buffer after this jump is inserted. */
2023 GET_BUFFER_SPACE (3);
2024 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
2032 /* At least one repetition is required, so insert a
2033 `dummy_failure_jump' before the initial
2034 `on_failure_jump' instruction of the loop. This
2035 effects a skip over that instruction the first time
2036 we hit that loop. */
2037 GET_BUFFER_SPACE (3);
2038 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
2053 boolean had_char_class = false;
2055 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2057 /* Ensure that we have enough space to push a charset: the
2058 opcode, the length count, and the bitset; 34 bytes in all. */
2059 GET_BUFFER_SPACE (34);
2063 /* We test `*p == '^' twice, instead of using an if
2064 statement, so we only need one BUF_PUSH. */
2065 BUF_PUSH (*p == '^' ? charset_not : charset);
2069 /* Remember the first position in the bracket expression. */
2072 /* Push the number of bytes in the bitmap. */
2073 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
2075 /* Clear the whole map. */
2076 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
2078 /* charset_not matches newline according to a syntax bit. */
2079 if ((re_opcode_t) b[-2] == charset_not
2080 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
2081 SET_LIST_BIT ('\n');
2083 /* Read in characters and ranges, setting map bits. */
2086 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2090 /* \ might escape characters inside [...] and [^...]. */
2091 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
2093 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2100 /* Could be the end of the bracket expression. If it's
2101 not (i.e., when the bracket expression is `[]' so
2102 far), the ']' character bit gets set way below. */
2103 if (c == ']' && p != p1 + 1)
2106 /* Look ahead to see if it's a range when the last thing
2107 was a character class. */
2108 if (had_char_class && c == '-' && *p != ']')
2109 FREE_STACK_RETURN (REG_ERANGE);
2111 /* Look ahead to see if it's a range when the last thing
2112 was a character: if this is a hyphen not at the
2113 beginning or the end of a list, then it's the range
2116 && !(p - 2 >= pattern && p[-2] == '[')
2117 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
2121 = compile_range (&p, pend, translate, syntax, b);
2122 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2125 else if (p[0] == '-' && p[1] != ']')
2126 { /* This handles ranges made up of characters only. */
2129 /* Move past the `-'. */
2132 ret = compile_range (&p, pend, translate, syntax, b);
2133 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2136 /* See if we're at the beginning of a possible character
2139 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
2140 { /* Leave room for the null. */
2141 char str[CHAR_CLASS_MAX_LENGTH + 1];
2146 /* If pattern is `[[:'. */
2147 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2152 if ((c == ':' && *p == ']') || p == pend
2153 || c1 == CHAR_CLASS_MAX_LENGTH)
2159 /* If isn't a word bracketed by `[:' and `:]':
2160 undo the ending character, the letters, and leave
2161 the leading `:' and `[' (but set bits for them). */
2162 if (c == ':' && *p == ']')
2164 /* GCC LOCAL: Skip this code if we don't have btowc(). btowc() is */
2165 /* defined in the 1994 Amendment 1 to ISO C and may not be present on */
2166 /* systems where we have wchar.h and wctype.h. */
2167 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H && defined HAVE_BTOWC)
2168 boolean is_lower = STREQ (str, "lower");
2169 boolean is_upper = STREQ (str, "upper");
2173 wt = IS_CHAR_CLASS (str);
2175 FREE_STACK_RETURN (REG_ECTYPE);
2177 /* Throw away the ] at the end of the character
2181 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2183 for (ch = 0; ch < 1 << BYTEWIDTH; ++ch)
2186 if (__iswctype (__btowc (ch), wt))
2189 if (iswctype (btowc (ch), wt))
2193 if (translate && (is_upper || is_lower)
2194 && (ISUPPER (ch) || ISLOWER (ch)))
2198 had_char_class = true;
2201 boolean is_alnum = STREQ (str, "alnum");
2202 boolean is_alpha = STREQ (str, "alpha");
2203 boolean is_blank = STREQ (str, "blank");
2204 boolean is_cntrl = STREQ (str, "cntrl");
2205 boolean is_digit = STREQ (str, "digit");
2206 boolean is_graph = STREQ (str, "graph");
2207 boolean is_lower = STREQ (str, "lower");
2208 boolean is_print = STREQ (str, "print");
2209 boolean is_punct = STREQ (str, "punct");
2210 boolean is_space = STREQ (str, "space");
2211 boolean is_upper = STREQ (str, "upper");
2212 boolean is_xdigit = STREQ (str, "xdigit");
2214 if (!IS_CHAR_CLASS (str))
2215 FREE_STACK_RETURN (REG_ECTYPE);
2217 /* Throw away the ] at the end of the character
2221 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2223 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
2225 /* This was split into 3 if's to
2226 avoid an arbitrary limit in some compiler. */
2227 if ( (is_alnum && ISALNUM (ch))
2228 || (is_alpha && ISALPHA (ch))
2229 || (is_blank && ISBLANK (ch))
2230 || (is_cntrl && ISCNTRL (ch)))
2232 if ( (is_digit && ISDIGIT (ch))
2233 || (is_graph && ISGRAPH (ch))
2234 || (is_lower && ISLOWER (ch))
2235 || (is_print && ISPRINT (ch)))
2237 if ( (is_punct && ISPUNCT (ch))
2238 || (is_space && ISSPACE (ch))
2239 || (is_upper && ISUPPER (ch))
2240 || (is_xdigit && ISXDIGIT (ch)))
2242 if ( translate && (is_upper || is_lower)
2243 && (ISUPPER (ch) || ISLOWER (ch)))
2246 had_char_class = true;
2247 #endif /* libc || wctype.h */
2256 had_char_class = false;
2261 had_char_class = false;
2266 /* Discard any (non)matching list bytes that are all 0 at the
2267 end of the map. Decrease the map-length byte too. */
2268 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
2276 if (syntax & RE_NO_BK_PARENS)
2283 if (syntax & RE_NO_BK_PARENS)
2290 if (syntax & RE_NEWLINE_ALT)
2297 if (syntax & RE_NO_BK_VBAR)
2304 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
2305 goto handle_interval;
2311 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2313 /* Do not translate the character after the \, so that we can
2314 distinguish, e.g., \B from \b, even if we normally would
2315 translate, e.g., B to b. */
2321 if (syntax & RE_NO_BK_PARENS)
2322 goto normal_backslash;
2328 if (COMPILE_STACK_FULL)
2330 RETALLOC (compile_stack.stack, compile_stack.size << 1,
2331 compile_stack_elt_t);
2332 if (compile_stack.stack == NULL) return REG_ESPACE;
2334 compile_stack.size <<= 1;
2337 /* These are the values to restore when we hit end of this
2338 group. They are all relative offsets, so that if the
2339 whole pattern moves because of realloc, they will still
2341 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2342 COMPILE_STACK_TOP.fixup_alt_jump
2343 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2344 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2345 COMPILE_STACK_TOP.regnum = regnum;
2347 /* We will eventually replace the 0 with the number of
2348 groups inner to this one. But do not push a
2349 start_memory for groups beyond the last one we can
2350 represent in the compiled pattern. */
2351 if (regnum <= MAX_REGNUM)
2353 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2354 BUF_PUSH_3 (start_memory, regnum, 0);
2357 compile_stack.avail++;
2362 /* If we've reached MAX_REGNUM groups, then this open
2363 won't actually generate any code, so we'll have to
2364 clear pending_exact explicitly. */
2370 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
2372 if (COMPILE_STACK_EMPTY)
2374 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2375 goto normal_backslash;
2377 FREE_STACK_RETURN (REG_ERPAREN);
2382 { /* Push a dummy failure point at the end of the
2383 alternative for a possible future
2384 `pop_failure_jump' to pop. See comments at
2385 `push_dummy_failure' in `re_match_2'. */
2386 BUF_PUSH (push_dummy_failure);
2388 /* We allocated space for this jump when we assigned
2389 to `fixup_alt_jump', in the `handle_alt' case below. */
2390 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2393 /* See similar code for backslashed left paren above. */
2394 if (COMPILE_STACK_EMPTY)
2396 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2399 FREE_STACK_RETURN (REG_ERPAREN);
2402 /* Since we just checked for an empty stack above, this
2403 ``can't happen''. */
2404 assert (compile_stack.avail != 0);
2406 /* We don't just want to restore into `regnum', because
2407 later groups should continue to be numbered higher,
2408 as in `(ab)c(de)' -- the second group is #2. */
2409 regnum_t this_group_regnum;
2411 compile_stack.avail--;
2412 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2414 = COMPILE_STACK_TOP.fixup_alt_jump
2415 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
2417 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2418 this_group_regnum = COMPILE_STACK_TOP.regnum;
2419 /* If we've reached MAX_REGNUM groups, then this open
2420 won't actually generate any code, so we'll have to
2421 clear pending_exact explicitly. */
2424 /* We're at the end of the group, so now we know how many
2425 groups were inside this one. */
2426 if (this_group_regnum <= MAX_REGNUM)
2428 unsigned char *inner_group_loc
2429 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2431 *inner_group_loc = regnum - this_group_regnum;
2432 BUF_PUSH_3 (stop_memory, this_group_regnum,
2433 regnum - this_group_regnum);
2439 case '|': /* `\|'. */
2440 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
2441 goto normal_backslash;
2443 if (syntax & RE_LIMITED_OPS)
2446 /* Insert before the previous alternative a jump which
2447 jumps to this alternative if the former fails. */
2448 GET_BUFFER_SPACE (3);
2449 INSERT_JUMP (on_failure_jump, begalt, b + 6);
2453 /* The alternative before this one has a jump after it
2454 which gets executed if it gets matched. Adjust that
2455 jump so it will jump to this alternative's analogous
2456 jump (put in below, which in turn will jump to the next
2457 (if any) alternative's such jump, etc.). The last such
2458 jump jumps to the correct final destination. A picture:
2464 If we are at `b', then fixup_alt_jump right now points to a
2465 three-byte space after `a'. We'll put in the jump, set
2466 fixup_alt_jump to right after `b', and leave behind three
2467 bytes which we'll fill in when we get to after `c'. */
2470 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2472 /* Mark and leave space for a jump after this alternative,
2473 to be filled in later either by next alternative or
2474 when know we're at the end of a series of alternatives. */
2476 GET_BUFFER_SPACE (3);
2485 /* If \{ is a literal. */
2486 if (!(syntax & RE_INTERVALS)
2487 /* If we're at `\{' and it's not the open-interval
2489 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2490 || (p - 2 == pattern && p == pend))
2491 goto normal_backslash;
2495 /* If got here, then the syntax allows intervals. */
2497 /* At least (most) this many matches must be made. */
2498 int lower_bound = -1, upper_bound = -1;
2500 beg_interval = p - 1;
2504 if (syntax & RE_NO_BK_BRACES)
2505 goto unfetch_interval;
2507 FREE_STACK_RETURN (REG_EBRACE);
2510 GET_UNSIGNED_NUMBER (lower_bound);
2514 GET_UNSIGNED_NUMBER (upper_bound);
2515 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
2518 /* Interval such as `{1}' => match exactly once. */
2519 upper_bound = lower_bound;
2521 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
2522 || lower_bound > upper_bound)
2524 if (syntax & RE_NO_BK_BRACES)
2525 goto unfetch_interval;
2527 FREE_STACK_RETURN (REG_BADBR);
2530 if (!(syntax & RE_NO_BK_BRACES))
2532 if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
2539 if (syntax & RE_NO_BK_BRACES)
2540 goto unfetch_interval;
2542 FREE_STACK_RETURN (REG_BADBR);
2545 /* We just parsed a valid interval. */
2547 /* If it's invalid to have no preceding re. */
2550 if (syntax & RE_CONTEXT_INVALID_OPS)
2551 FREE_STACK_RETURN (REG_BADRPT);
2552 else if (syntax & RE_CONTEXT_INDEP_OPS)
2555 goto unfetch_interval;
2558 /* If the upper bound is zero, don't want to succeed at
2559 all; jump from `laststart' to `b + 3', which will be
2560 the end of the buffer after we insert the jump. */
2561 if (upper_bound == 0)
2563 GET_BUFFER_SPACE (3);
2564 INSERT_JUMP (jump, laststart, b + 3);
2568 /* Otherwise, we have a nontrivial interval. When
2569 we're all done, the pattern will look like:
2570 set_number_at <jump count> <upper bound>
2571 set_number_at <succeed_n count> <lower bound>
2572 succeed_n <after jump addr> <succeed_n count>
2574 jump_n <succeed_n addr> <jump count>
2575 (The upper bound and `jump_n' are omitted if
2576 `upper_bound' is 1, though.) */
2578 { /* If the upper bound is > 1, we need to insert
2579 more at the end of the loop. */
2580 unsigned nbytes = 10 + (upper_bound > 1) * 10;
2582 GET_BUFFER_SPACE (nbytes);
2584 /* Initialize lower bound of the `succeed_n', even
2585 though it will be set during matching by its
2586 attendant `set_number_at' (inserted next),
2587 because `re_compile_fastmap' needs to know.
2588 Jump to the `jump_n' we might insert below. */
2589 INSERT_JUMP2 (succeed_n, laststart,
2590 b + 5 + (upper_bound > 1) * 5,
2594 /* Code to initialize the lower bound. Insert
2595 before the `succeed_n'. The `5' is the last two
2596 bytes of this `set_number_at', plus 3 bytes of
2597 the following `succeed_n'. */
2598 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2601 if (upper_bound > 1)
2602 { /* More than one repetition is allowed, so
2603 append a backward jump to the `succeed_n'
2604 that starts this interval.
2606 When we've reached this during matching,
2607 we'll have matched the interval once, so
2608 jump back only `upper_bound - 1' times. */
2609 STORE_JUMP2 (jump_n, b, laststart + 5,
2613 /* The location we want to set is the second
2614 parameter of the `jump_n'; that is `b-2' as
2615 an absolute address. `laststart' will be
2616 the `set_number_at' we're about to insert;
2617 `laststart+3' the number to set, the source
2618 for the relative address. But we are
2619 inserting into the middle of the pattern --
2620 so everything is getting moved up by 5.
2621 Conclusion: (b - 2) - (laststart + 3) + 5,
2622 i.e., b - laststart.
2624 We insert this at the beginning of the loop
2625 so that if we fail during matching, we'll
2626 reinitialize the bounds. */
2627 insert_op2 (set_number_at, laststart, b - laststart,
2628 upper_bound - 1, b);
2633 beg_interval = NULL;
2638 /* If an invalid interval, match the characters as literals. */
2639 assert (beg_interval);
2641 beg_interval = NULL;
2643 /* normal_char and normal_backslash need `c'. */
2646 if (!(syntax & RE_NO_BK_BRACES))
2648 if (p > pattern && p[-1] == '\\')
2649 goto normal_backslash;
2654 /* There is no way to specify the before_dot and after_dot
2655 operators. rms says this is ok. --karl */
2663 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2669 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2675 if (syntax & RE_NO_GNU_OPS)
2678 BUF_PUSH (wordchar);
2683 if (syntax & RE_NO_GNU_OPS)
2686 BUF_PUSH (notwordchar);
2691 if (syntax & RE_NO_GNU_OPS)
2697 if (syntax & RE_NO_GNU_OPS)
2703 if (syntax & RE_NO_GNU_OPS)
2705 BUF_PUSH (wordbound);
2709 if (syntax & RE_NO_GNU_OPS)
2711 BUF_PUSH (notwordbound);
2715 if (syntax & RE_NO_GNU_OPS)
2721 if (syntax & RE_NO_GNU_OPS)
2726 case '1': case '2': case '3': case '4': case '5':
2727 case '6': case '7': case '8': case '9':
2728 if (syntax & RE_NO_BK_REFS)
2734 FREE_STACK_RETURN (REG_ESUBREG);
2736 /* Can't back reference to a subexpression if inside of it. */
2737 if (group_in_compile_stack (compile_stack, (regnum_t) c1))
2741 BUF_PUSH_2 (duplicate, c1);
2747 if (syntax & RE_BK_PLUS_QM)
2750 goto normal_backslash;
2754 /* You might think it would be useful for \ to mean
2755 not to translate; but if we don't translate it
2756 it will never match anything. */
2764 /* Expects the character in `c'. */
2766 /* If no exactn currently being built. */
2769 /* If last exactn not at current position. */
2770 || pending_exact + *pending_exact + 1 != b
2772 /* We have only one byte following the exactn for the count. */
2773 || *pending_exact == (1 << BYTEWIDTH) - 1
2775 /* If followed by a repetition operator. */
2776 || *p == '*' || *p == '^'
2777 || ((syntax & RE_BK_PLUS_QM)
2778 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2779 : (*p == '+' || *p == '?'))
2780 || ((syntax & RE_INTERVALS)
2781 && ((syntax & RE_NO_BK_BRACES)
2783 : (p[0] == '\\' && p[1] == '{'))))
2785 /* Start building a new exactn. */
2789 BUF_PUSH_2 (exactn, 0);
2790 pending_exact = b - 1;
2797 } /* while p != pend */
2800 /* Through the pattern now. */
2803 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2805 if (!COMPILE_STACK_EMPTY)
2806 FREE_STACK_RETURN (REG_EPAREN);
2808 /* If we don't want backtracking, force success
2809 the first time we reach the end of the compiled pattern. */
2810 if (syntax & RE_NO_POSIX_BACKTRACKING)
2813 free (compile_stack.stack);
2815 /* We have succeeded; set the length of the buffer. */
2816 bufp->used = b - bufp->buffer;
2821 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2822 print_compiled_pattern (bufp);
2826 #ifndef MATCH_MAY_ALLOCATE
2827 /* Initialize the failure stack to the largest possible stack. This
2828 isn't necessary unless we're trying to avoid calling alloca in
2829 the search and match routines. */
2831 int num_regs = bufp->re_nsub + 1;
2833 /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2834 is strictly greater than re_max_failures, the largest possible stack
2835 is 2 * re_max_failures failure points. */
2836 if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
2838 fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2841 if (! fail_stack.stack)
2843 = (fail_stack_elt_t *) xmalloc (fail_stack.size
2844 * sizeof (fail_stack_elt_t));
2847 = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
2849 * sizeof (fail_stack_elt_t)));
2850 # else /* not emacs */
2851 if (! fail_stack.stack)
2853 = (fail_stack_elt_t *) malloc (fail_stack.size
2854 * sizeof (fail_stack_elt_t));
2857 = (fail_stack_elt_t *) realloc (fail_stack.stack,
2859 * sizeof (fail_stack_elt_t)));
2860 # endif /* not emacs */
2863 regex_grow_registers (num_regs);
2865 #endif /* not MATCH_MAY_ALLOCATE */
2868 } /* regex_compile */
2870 /* Subroutines for `regex_compile'. */
2872 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2875 store_op1 (op, loc, arg)
2880 *loc = (unsigned char) op;
2881 STORE_NUMBER (loc + 1, arg);
2885 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2888 store_op2 (op, loc, arg1, arg2)
2893 *loc = (unsigned char) op;
2894 STORE_NUMBER (loc + 1, arg1);
2895 STORE_NUMBER (loc + 3, arg2);
2899 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2900 for OP followed by two-byte integer parameter ARG. */
2903 insert_op1 (op, loc, arg, end)
2909 register unsigned char *pfrom = end;
2910 register unsigned char *pto = end + 3;
2912 while (pfrom != loc)
2915 store_op1 (op, loc, arg);
2919 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2922 insert_op2 (op, loc, arg1, arg2, end)
2928 register unsigned char *pfrom = end;
2929 register unsigned char *pto = end + 5;
2931 while (pfrom != loc)
2934 store_op2 (op, loc, arg1, arg2);
2938 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2939 after an alternative or a begin-subexpression. We assume there is at
2940 least one character before the ^. */
2943 at_begline_loc_p (pattern, p, syntax)
2944 const char *pattern, *p;
2945 reg_syntax_t syntax;
2947 const char *prev = p - 2;
2948 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2951 /* After a subexpression? */
2952 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2953 /* After an alternative? */
2954 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2958 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2959 at least one character after the $, i.e., `P < PEND'. */
2962 at_endline_loc_p (p, pend, syntax)
2963 const char *p, *pend;
2964 reg_syntax_t syntax;
2966 const char *next = p;
2967 boolean next_backslash = *next == '\\';
2968 const char *next_next = p + 1 < pend ? p + 1 : 0;
2971 /* Before a subexpression? */
2972 (syntax & RE_NO_BK_PARENS ? *next == ')'
2973 : next_backslash && next_next && *next_next == ')')
2974 /* Before an alternative? */
2975 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2976 : next_backslash && next_next && *next_next == '|');
2980 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2981 false if it's not. */
2984 group_in_compile_stack (compile_stack, regnum)
2985 compile_stack_type compile_stack;
2990 for (this_element = compile_stack.avail - 1;
2993 if (compile_stack.stack[this_element].regnum == regnum)
3000 /* Read the ending character of a range (in a bracket expression) from the
3001 uncompiled pattern *P_PTR (which ends at PEND). We assume the
3002 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
3003 Then we set the translation of all bits between the starting and
3004 ending characters (inclusive) in the compiled pattern B.
3006 Return an error code.
3008 We use these short variable names so we can use the same macros as
3009 `regex_compile' itself. */
3011 static reg_errcode_t
3012 compile_range (p_ptr, pend, translate, syntax, b)
3013 const char **p_ptr, *pend;
3014 RE_TRANSLATE_TYPE translate;
3015 reg_syntax_t syntax;
3020 const char *p = *p_ptr;
3021 unsigned int range_start, range_end;
3026 /* Even though the pattern is a signed `char *', we need to fetch
3027 with unsigned char *'s; if the high bit of the pattern character
3028 is set, the range endpoints will be negative if we fetch using a
3031 We also want to fetch the endpoints without translating them; the
3032 appropriate translation is done in the bit-setting loop below. */
3033 /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *. */
3034 range_start = ((const unsigned char *) p)[-2];
3035 range_end = ((const unsigned char *) p)[0];
3037 /* Have to increment the pointer into the pattern string, so the
3038 caller isn't still at the ending character. */
3041 /* If the start is after the end, the range is empty. */
3042 if (range_start > range_end)
3043 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
3045 /* Here we see why `this_char' has to be larger than an `unsigned
3046 char' -- the range is inclusive, so if `range_end' == 0xff
3047 (assuming 8-bit characters), we would otherwise go into an infinite
3048 loop, since all characters <= 0xff. */
3049 for (this_char = range_start; this_char <= range_end; this_char++)
3051 SET_LIST_BIT (TRANSLATE (this_char));
3057 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
3058 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
3059 characters can start a string that matches the pattern. This fastmap
3060 is used by re_search to skip quickly over impossible starting points.
3062 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
3063 area as BUFP->fastmap.
3065 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
3068 Returns 0 if we succeed, -2 if an internal error. */
3071 re_compile_fastmap (bufp)
3072 struct re_pattern_buffer *bufp;
3075 #ifdef MATCH_MAY_ALLOCATE
3076 fail_stack_type fail_stack;
3078 #ifndef REGEX_MALLOC
3082 register char *fastmap = bufp->fastmap;
3083 unsigned char *pattern = bufp->buffer;
3084 unsigned char *p = pattern;
3085 register unsigned char *pend = pattern + bufp->used;
3088 /* This holds the pointer to the failure stack, when
3089 it is allocated relocatably. */
3090 fail_stack_elt_t *failure_stack_ptr;
3093 /* Assume that each path through the pattern can be null until
3094 proven otherwise. We set this false at the bottom of switch
3095 statement, to which we get only if a particular path doesn't
3096 match the empty string. */
3097 boolean path_can_be_null = true;
3099 /* We aren't doing a `succeed_n' to begin with. */
3100 boolean succeed_n_p = false;
3102 assert (fastmap != NULL && p != NULL);
3105 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
3106 bufp->fastmap_accurate = 1; /* It will be when we're done. */
3107 bufp->can_be_null = 0;
3111 if (p == pend || *p == succeed)
3113 /* We have reached the (effective) end of pattern. */
3114 if (!FAIL_STACK_EMPTY ())
3116 bufp->can_be_null |= path_can_be_null;
3118 /* Reset for next path. */
3119 path_can_be_null = true;
3121 p = fail_stack.stack[--fail_stack.avail].pointer;
3129 /* We should never be about to go beyond the end of the pattern. */
3132 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
3135 /* I guess the idea here is to simply not bother with a fastmap
3136 if a backreference is used, since it's too hard to figure out
3137 the fastmap for the corresponding group. Setting
3138 `can_be_null' stops `re_search_2' from using the fastmap, so
3139 that is all we do. */
3141 bufp->can_be_null = 1;
3145 /* Following are the cases which match a character. These end
3154 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
3155 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
3161 /* Chars beyond end of map must be allowed. */
3162 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
3165 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
3166 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
3172 for (j = 0; j < (1 << BYTEWIDTH); j++)
3173 if (SYNTAX (j) == Sword)
3179 for (j = 0; j < (1 << BYTEWIDTH); j++)
3180 if (SYNTAX (j) != Sword)
3187 int fastmap_newline = fastmap['\n'];
3189 /* `.' matches anything ... */
3190 for (j = 0; j < (1 << BYTEWIDTH); j++)
3193 /* ... except perhaps newline. */
3194 if (!(bufp->syntax & RE_DOT_NEWLINE))
3195 fastmap['\n'] = fastmap_newline;
3197 /* Return if we have already set `can_be_null'; if we have,
3198 then the fastmap is irrelevant. Something's wrong here. */
3199 else if (bufp->can_be_null)
3202 /* Otherwise, have to check alternative paths. */
3209 for (j = 0; j < (1 << BYTEWIDTH); j++)
3210 if (SYNTAX (j) == (enum syntaxcode) k)
3217 for (j = 0; j < (1 << BYTEWIDTH); j++)
3218 if (SYNTAX (j) != (enum syntaxcode) k)
3223 /* All cases after this match the empty string. These end with
3243 case push_dummy_failure:
3248 case pop_failure_jump:
3249 case maybe_pop_jump:
3252 case dummy_failure_jump:
3253 EXTRACT_NUMBER_AND_INCR (j, p);
3258 /* Jump backward implies we just went through the body of a
3259 loop and matched nothing. Opcode jumped to should be
3260 `on_failure_jump' or `succeed_n'. Just treat it like an
3261 ordinary jump. For a * loop, it has pushed its failure
3262 point already; if so, discard that as redundant. */
3263 if ((re_opcode_t) *p != on_failure_jump
3264 && (re_opcode_t) *p != succeed_n)
3268 EXTRACT_NUMBER_AND_INCR (j, p);
3271 /* If what's on the stack is where we are now, pop it. */
3272 if (!FAIL_STACK_EMPTY ()
3273 && fail_stack.stack[fail_stack.avail - 1].pointer == p)
3279 case on_failure_jump:
3280 case on_failure_keep_string_jump:
3281 handle_on_failure_jump:
3282 EXTRACT_NUMBER_AND_INCR (j, p);
3284 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
3285 end of the pattern. We don't want to push such a point,
3286 since when we restore it above, entering the switch will
3287 increment `p' past the end of the pattern. We don't need
3288 to push such a point since we obviously won't find any more
3289 fastmap entries beyond `pend'. Such a pattern can match
3290 the null string, though. */
3293 if (!PUSH_PATTERN_OP (p + j, fail_stack))
3295 RESET_FAIL_STACK ();
3300 bufp->can_be_null = 1;
3304 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
3305 succeed_n_p = false;
3312 /* Get to the number of times to succeed. */
3315 /* Increment p past the n for when k != 0. */
3316 EXTRACT_NUMBER_AND_INCR (k, p);
3320 succeed_n_p = true; /* Spaghetti code alert. */
3321 goto handle_on_failure_jump;
3338 abort (); /* We have listed all the cases. */
3341 /* Getting here means we have found the possible starting
3342 characters for one path of the pattern -- and that the empty
3343 string does not match. We need not follow this path further.
3344 Instead, look at the next alternative (remembered on the
3345 stack), or quit if no more. The test at the top of the loop
3346 does these things. */
3347 path_can_be_null = false;
3351 /* Set `can_be_null' for the last path (also the first path, if the
3352 pattern is empty). */
3353 bufp->can_be_null |= path_can_be_null;
3356 RESET_FAIL_STACK ();
3358 } /* re_compile_fastmap */
3360 weak_alias (__re_compile_fastmap, re_compile_fastmap)
3363 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
3364 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
3365 this memory for recording register information. STARTS and ENDS
3366 must be allocated using the malloc library routine, and must each
3367 be at least NUM_REGS * sizeof (regoff_t) bytes long.
3369 If NUM_REGS == 0, then subsequent matches should allocate their own
3372 Unless this function is called, the first search or match using
3373 PATTERN_BUFFER will allocate its own register data, without
3374 freeing the old data. */
3377 re_set_registers (bufp, regs, num_regs, starts, ends)
3378 struct re_pattern_buffer *bufp;
3379 struct re_registers *regs;
3381 regoff_t *starts, *ends;
3385 bufp->regs_allocated = REGS_REALLOCATE;
3386 regs->num_regs = num_regs;
3387 regs->start = starts;
3392 bufp->regs_allocated = REGS_UNALLOCATED;
3394 regs->start = regs->end = (regoff_t *) 0;
3398 weak_alias (__re_set_registers, re_set_registers)
3401 /* Searching routines. */
3403 /* Like re_search_2, below, but only one string is specified, and
3404 doesn't let you say where to stop matching. */
3407 re_search (bufp, string, size, startpos, range, regs)
3408 struct re_pattern_buffer *bufp;
3410 int size, startpos, range;
3411 struct re_registers *regs;
3413 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3417 weak_alias (__re_search, re_search)
3421 /* Using the compiled pattern in BUFP->buffer, first tries to match the
3422 virtual concatenation of STRING1 and STRING2, starting first at index
3423 STARTPOS, then at STARTPOS + 1, and so on.
3425 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3427 RANGE is how far to scan while trying to match. RANGE = 0 means try
3428 only at STARTPOS; in general, the last start tried is STARTPOS +
3431 In REGS, return the indices of the virtual concatenation of STRING1
3432 and STRING2 that matched the entire BUFP->buffer and its contained
3435 Do not consider matching one past the index STOP in the virtual
3436 concatenation of STRING1 and STRING2.
3438 We return either the position in the strings at which the match was
3439 found, -1 if no match, or -2 if error (such as failure
3443 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3444 struct re_pattern_buffer *bufp;
3445 const char *string1, *string2;
3449 struct re_registers *regs;
3453 register char *fastmap = bufp->fastmap;
3454 register RE_TRANSLATE_TYPE translate = bufp->translate;
3455 int total_size = size1 + size2;
3456 int endpos = startpos + range;
3458 /* Check for out-of-range STARTPOS. */
3459 if (startpos < 0 || startpos > total_size)
3462 /* Fix up RANGE if it might eventually take us outside
3463 the virtual concatenation of STRING1 and STRING2.
3464 Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE. */
3466 range = 0 - startpos;
3467 else if (endpos > total_size)
3468 range = total_size - startpos;
3470 /* If the search isn't to be a backwards one, don't waste time in a
3471 search for a pattern that must be anchored. */
3472 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3481 /* In a forward search for something that starts with \=.
3482 don't keep searching past point. */
3483 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0)
3485 range = PT - startpos;
3491 /* Update the fastmap now if not correct already. */
3492 if (fastmap && !bufp->fastmap_accurate)
3493 if (re_compile_fastmap (bufp) == -2)
3496 /* Loop through the string, looking for a place to start matching. */
3499 /* If a fastmap is supplied, skip quickly over characters that
3500 cannot be the start of a match. If the pattern can match the
3501 null string, however, we don't need to skip characters; we want
3502 the first null string. */
3503 if (fastmap && startpos < total_size && !bufp->can_be_null)
3505 if (range > 0) /* Searching forwards. */
3507 register const char *d;
3508 register int lim = 0;
3511 if (startpos < size1 && startpos + range >= size1)
3512 lim = range - (size1 - startpos);
3514 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3516 /* Written out as an if-else to avoid testing `translate'
3520 && !fastmap[(unsigned char)
3521 translate[(unsigned char) *d++]])
3524 while (range > lim && !fastmap[(unsigned char) *d++])
3527 startpos += irange - range;
3529 else /* Searching backwards. */
3531 register char c = (size1 == 0 || startpos >= size1
3532 ? string2[startpos - size1]
3533 : string1[startpos]);
3535 if (!fastmap[(unsigned char) TRANSLATE (c)])
3540 /* If can't match the null string, and that's all we have left, fail. */
3541 if (range >= 0 && startpos == total_size && fastmap
3542 && !bufp->can_be_null)
3545 val = re_match_2_internal (bufp, string1, size1, string2, size2,
3546 startpos, regs, stop);
3547 #ifndef REGEX_MALLOC
3576 weak_alias (__re_search_2, re_search_2)
3579 /* This converts PTR, a pointer into one of the search strings `string1'
3580 and `string2' into an offset from the beginning of that string. */
3581 #define POINTER_TO_OFFSET(ptr) \
3582 (FIRST_STRING_P (ptr) \
3583 ? ((regoff_t) ((ptr) - string1)) \
3584 : ((regoff_t) ((ptr) - string2 + size1)))
3586 /* Macros for dealing with the split strings in re_match_2. */
3588 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3590 /* Call before fetching a character with *d. This switches over to
3591 string2 if necessary. */
3592 #define PREFETCH() \
3595 /* End of string2 => fail. */ \
3596 if (dend == end_match_2) \
3598 /* End of string1 => advance to string2. */ \
3600 dend = end_match_2; \
3604 /* Test if at very beginning or at very end of the virtual concatenation
3605 of `string1' and `string2'. If only one string, it's `string2'. */
3606 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3607 #define AT_STRINGS_END(d) ((d) == end2)
3610 /* Test if D points to a character which is word-constituent. We have
3611 two special cases to check for: if past the end of string1, look at
3612 the first character in string2; and if before the beginning of
3613 string2, look at the last character in string1. */
3614 #define WORDCHAR_P(d) \
3615 (SYNTAX ((d) == end1 ? *string2 \
3616 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3619 /* Disabled due to a compiler bug -- see comment at case wordbound */
3621 /* Test if the character before D and the one at D differ with respect
3622 to being word-constituent. */
3623 #define AT_WORD_BOUNDARY(d) \
3624 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3625 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3628 /* Free everything we malloc. */
3629 #ifdef MATCH_MAY_ALLOCATE
3630 # define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
3631 # define FREE_VARIABLES() \
3633 REGEX_FREE_STACK (fail_stack.stack); \
3634 FREE_VAR (regstart); \
3635 FREE_VAR (regend); \
3636 FREE_VAR (old_regstart); \
3637 FREE_VAR (old_regend); \
3638 FREE_VAR (best_regstart); \
3639 FREE_VAR (best_regend); \
3640 FREE_VAR (reg_info); \
3641 FREE_VAR (reg_dummy); \
3642 FREE_VAR (reg_info_dummy); \
3645 # define FREE_VARIABLES() ((void)0) /* Do nothing! But inhibit gcc warning. */
3646 #endif /* not MATCH_MAY_ALLOCATE */
3648 /* These values must meet several constraints. They must not be valid
3649 register values; since we have a limit of 255 registers (because
3650 we use only one byte in the pattern for the register number), we can
3651 use numbers larger than 255. They must differ by 1, because of
3652 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3653 be larger than the value for the highest register, so we do not try
3654 to actually save any registers when none are active. */
3655 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3656 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3658 /* Matching routines. */
3660 #ifndef emacs /* Emacs never uses this. */
3661 /* re_match is like re_match_2 except it takes only a single string. */
3664 re_match (bufp, string, size, pos, regs)
3665 struct re_pattern_buffer *bufp;
3668 struct re_registers *regs;
3670 int result = re_match_2_internal (bufp, NULL, 0, string, size,
3672 # ifndef REGEX_MALLOC
3680 weak_alias (__re_match, re_match)
3682 #endif /* not emacs */
3684 static boolean group_match_null_string_p _RE_ARGS ((unsigned char **p,
3686 register_info_type *reg_info));
3687 static boolean alt_match_null_string_p _RE_ARGS ((unsigned char *p,
3689 register_info_type *reg_info));
3690 static boolean common_op_match_null_string_p _RE_ARGS ((unsigned char **p,
3692 register_info_type *reg_info));
3693 static int bcmp_translate _RE_ARGS ((const char *s1, const char *s2,
3694 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. */
3710 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3711 struct re_pattern_buffer *bufp;
3712 const char *string1, *string2;
3715 struct re_registers *regs;
3718 int result = re_match_2_internal (bufp, string1, size1, string2, size2,
3720 #ifndef REGEX_MALLOC
3728 weak_alias (__re_match_2, re_match_2)
3731 /* This is a separate function so that we can force an alloca cleanup
3734 re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
3735 struct re_pattern_buffer *bufp;
3736 const char *string1, *string2;
3739 struct re_registers *regs;
3742 /* General temporaries. */
3746 /* Just past the end of the corresponding string. */
3747 const char *end1, *end2;
3749 /* Pointers into string1 and string2, just past the last characters in
3750 each to consider matching. */
3751 const char *end_match_1, *end_match_2;
3753 /* Where we are in the data, and the end of the current string. */
3754 const char *d, *dend;
3756 /* Where we are in the pattern, and the end of the pattern. */
3757 unsigned char *p = bufp->buffer;
3758 register unsigned char *pend = p + bufp->used;
3760 /* Mark the opcode just after a start_memory, so we can test for an
3761 empty subpattern when we get to the stop_memory. */
3762 unsigned char *just_past_start_mem = 0;
3764 /* We use this to map every character in the string. */
3765 RE_TRANSLATE_TYPE translate = bufp->translate;
3767 /* Failure point stack. Each place that can handle a failure further
3768 down the line pushes a failure point on this stack. It consists of
3769 restart, regend, and reg_info for all registers corresponding to
3770 the subexpressions we're currently inside, plus the number of such
3771 registers, and, finally, two char *'s. The first char * is where
3772 to resume scanning the pattern; the second one is where to resume
3773 scanning the strings. If the latter is zero, the failure point is
3774 a ``dummy''; if a failure happens and the failure point is a dummy,
3775 it gets discarded and the next next one is tried. */
3776 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3777 fail_stack_type fail_stack;
3780 static unsigned failure_id = 0;
3781 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3785 /* This holds the pointer to the failure stack, when
3786 it is allocated relocatably. */
3787 fail_stack_elt_t *failure_stack_ptr;
3790 /* We fill all the registers internally, independent of what we
3791 return, for use in backreferences. The number here includes
3792 an element for register zero. */
3793 size_t num_regs = bufp->re_nsub + 1;
3795 /* The currently active registers. */
3796 active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3797 active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3799 /* Information on the contents of registers. These are pointers into
3800 the input strings; they record just what was matched (on this
3801 attempt) by a subexpression part of the pattern, that is, the
3802 regnum-th regstart pointer points to where in the pattern we began
3803 matching and the regnum-th regend points to right after where we
3804 stopped matching the regnum-th subexpression. (The zeroth register
3805 keeps track of what the whole pattern matches.) */
3806 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3807 const char **regstart, **regend;
3810 /* If a group that's operated upon by a repetition operator fails to
3811 match anything, then the register for its start will need to be
3812 restored because it will have been set to wherever in the string we
3813 are when we last see its open-group operator. Similarly for a
3815 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3816 const char **old_regstart, **old_regend;
3819 /* The is_active field of reg_info helps us keep track of which (possibly
3820 nested) subexpressions we are currently in. The matched_something
3821 field of reg_info[reg_num] helps us tell whether or not we have
3822 matched any of the pattern so far this time through the reg_num-th
3823 subexpression. These two fields get reset each time through any
3824 loop their register is in. */
3825 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3826 register_info_type *reg_info;
3829 /* The following record the register info as found in the above
3830 variables when we find a match better than any we've seen before.
3831 This happens as we backtrack through the failure points, which in
3832 turn happens only if we have not yet matched the entire string. */
3833 unsigned best_regs_set = false;
3834 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3835 const char **best_regstart, **best_regend;
3838 /* Logically, this is `best_regend[0]'. But we don't want to have to
3839 allocate space for that if we're not allocating space for anything
3840 else (see below). Also, we never need info about register 0 for
3841 any of the other register vectors, and it seems rather a kludge to
3842 treat `best_regend' differently than the rest. So we keep track of
3843 the end of the best match so far in a separate variable. We
3844 initialize this to NULL so that when we backtrack the first time
3845 and need to test it, it's not garbage. */
3846 const char *match_end = NULL;
3848 /* This helps SET_REGS_MATCHED avoid doing redundant work. */
3849 int set_regs_matched_done = 0;
3851 /* Used when we pop values we don't care about. */
3852 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3853 const char **reg_dummy;
3854 register_info_type *reg_info_dummy;
3858 /* Counts the total number of registers pushed. */
3859 unsigned num_regs_pushed = 0;
3862 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3866 #ifdef MATCH_MAY_ALLOCATE
3867 /* Do not bother to initialize all the register variables if there are
3868 no groups in the pattern, as it takes a fair amount of time. If
3869 there are groups, we include space for register 0 (the whole
3870 pattern), even though we never use it, since it simplifies the
3871 array indexing. We should fix this. */
3874 regstart = REGEX_TALLOC (num_regs, const char *);
3875 regend = REGEX_TALLOC (num_regs, const char *);
3876 old_regstart = REGEX_TALLOC (num_regs, const char *);
3877 old_regend = REGEX_TALLOC (num_regs, const char *);
3878 best_regstart = REGEX_TALLOC (num_regs, const char *);
3879 best_regend = REGEX_TALLOC (num_regs, const char *);
3880 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3881 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3882 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3884 if (!(regstart && regend && old_regstart && old_regend && reg_info
3885 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3893 /* We must initialize all our variables to NULL, so that
3894 `FREE_VARIABLES' doesn't try to free them. */
3895 regstart = regend = old_regstart = old_regend = best_regstart
3896 = best_regend = reg_dummy = NULL;
3897 reg_info = reg_info_dummy = (register_info_type *) NULL;
3899 #endif /* MATCH_MAY_ALLOCATE */
3901 /* The starting position is bogus. */
3902 if (pos < 0 || pos > size1 + size2)
3908 /* Initialize subexpression text positions to -1 to mark ones that no
3909 start_memory/stop_memory has been seen for. Also initialize the
3910 register information struct. */
3911 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
3913 regstart[mcnt] = regend[mcnt]
3914 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3916 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3917 IS_ACTIVE (reg_info[mcnt]) = 0;
3918 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3919 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3922 /* We move `string1' into `string2' if the latter's empty -- but not if
3923 `string1' is null. */
3924 if (size2 == 0 && string1 != NULL)
3931 end1 = string1 + size1;
3932 end2 = string2 + size2;
3934 /* Compute where to stop matching, within the two strings. */
3937 end_match_1 = string1 + stop;
3938 end_match_2 = string2;
3943 end_match_2 = string2 + stop - size1;
3946 /* `p' scans through the pattern as `d' scans through the data.
3947 `dend' is the end of the input string that `d' points within. `d'
3948 is advanced into the following input string whenever necessary, but
3949 this happens before fetching; therefore, at the beginning of the
3950 loop, `d' can be pointing at the end of a string, but it cannot
3952 if (size1 > 0 && pos <= size1)
3959 d = string2 + pos - size1;
3963 DEBUG_PRINT1 ("The compiled pattern is:\n");
3964 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3965 DEBUG_PRINT1 ("The string to match is: `");
3966 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3967 DEBUG_PRINT1 ("'\n");
3969 /* This loops over pattern commands. It exits by returning from the
3970 function if the match is complete, or it drops through if the match
3971 fails at this starting point in the input data. */
3975 DEBUG_PRINT2 ("\n%p: ", p);
3977 DEBUG_PRINT2 ("\n0x%x: ", p);
3981 { /* End of pattern means we might have succeeded. */
3982 DEBUG_PRINT1 ("end of pattern ... ");
3984 /* If we haven't matched the entire string, and we want the
3985 longest match, try backtracking. */
3986 if (d != end_match_2)
3988 /* 1 if this match ends in the same string (string1 or string2)
3989 as the best previous match. */
3990 boolean same_str_p = (FIRST_STRING_P (match_end)
3991 == MATCHING_IN_FIRST_STRING);
3992 /* 1 if this match is the best seen so far. */
3993 boolean best_match_p;
3995 /* AIX compiler got confused when this was combined
3996 with the previous declaration. */
3998 best_match_p = d > match_end;
4000 best_match_p = !MATCHING_IN_FIRST_STRING;
4002 DEBUG_PRINT1 ("backtracking.\n");
4004 if (!FAIL_STACK_EMPTY ())
4005 { /* More failure points to try. */
4007 /* If exceeds best match so far, save it. */
4008 if (!best_regs_set || best_match_p)
4010 best_regs_set = true;
4013 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
4015 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
4017 best_regstart[mcnt] = regstart[mcnt];
4018 best_regend[mcnt] = regend[mcnt];
4024 /* If no failure points, don't restore garbage. And if
4025 last match is real best match, don't restore second
4027 else if (best_regs_set && !best_match_p)
4030 /* Restore best match. It may happen that `dend ==
4031 end_match_1' while the restored d is in string2.
4032 For example, the pattern `x.*y.*z' against the
4033 strings `x-' and `y-z-', if the two strings are
4034 not consecutive in memory. */
4035 DEBUG_PRINT1 ("Restoring best registers.\n");
4038 dend = ((d >= string1 && d <= end1)
4039 ? end_match_1 : end_match_2);
4041 for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
4043 regstart[mcnt] = best_regstart[mcnt];
4044 regend[mcnt] = best_regend[mcnt];
4047 } /* d != end_match_2 */
4050 DEBUG_PRINT1 ("Accepting match.\n");
4052 /* If caller wants register contents data back, do it. */
4053 if (regs && !bufp->no_sub)
4055 /* Have the register data arrays been allocated? */
4056 if (bufp->regs_allocated == REGS_UNALLOCATED)
4057 { /* No. So allocate them with malloc. We need one
4058 extra element beyond `num_regs' for the `-1' marker
4060 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
4061 regs->start = TALLOC (regs->num_regs, regoff_t);
4062 regs->end = TALLOC (regs->num_regs, regoff_t);
4063 if (regs->start == NULL || regs->end == NULL)
4068 bufp->regs_allocated = REGS_REALLOCATE;
4070 else if (bufp->regs_allocated == REGS_REALLOCATE)
4071 { /* Yes. If we need more elements than were already
4072 allocated, reallocate them. If we need fewer, just
4074 if (regs->num_regs < num_regs + 1)
4076 regs->num_regs = num_regs + 1;
4077 RETALLOC (regs->start, regs->num_regs, regoff_t);
4078 RETALLOC (regs->end, regs->num_regs, regoff_t);
4079 if (regs->start == NULL || regs->end == NULL)
4088 /* These braces fend off a "empty body in an else-statement"
4089 warning under GCC when assert expands to nothing. */
4090 assert (bufp->regs_allocated == REGS_FIXED);
4093 /* Convert the pointer data in `regstart' and `regend' to
4094 indices. Register zero has to be set differently,
4095 since we haven't kept track of any info for it. */
4096 if (regs->num_regs > 0)
4098 regs->start[0] = pos;
4099 regs->end[0] = (MATCHING_IN_FIRST_STRING
4100 ? ((regoff_t) (d - string1))
4101 : ((regoff_t) (d - string2 + size1)));
4104 /* Go through the first `min (num_regs, regs->num_regs)'
4105 registers, since that is all we initialized. */
4106 for (mcnt = 1; (unsigned) mcnt < MIN (num_regs, regs->num_regs);
4109 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
4110 regs->start[mcnt] = regs->end[mcnt] = -1;
4114 = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
4116 = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
4120 /* If the regs structure we return has more elements than
4121 were in the pattern, set the extra elements to -1. If
4122 we (re)allocated the registers, this is the case,
4123 because we always allocate enough to have at least one
4125 for (mcnt = num_regs; (unsigned) mcnt < regs->num_regs; mcnt++)
4126 regs->start[mcnt] = regs->end[mcnt] = -1;
4127 } /* regs && !bufp->no_sub */
4129 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
4130 nfailure_points_pushed, nfailure_points_popped,
4131 nfailure_points_pushed - nfailure_points_popped);
4132 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
4134 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
4138 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
4144 /* Otherwise match next pattern command. */
4145 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
4147 /* Ignore these. Used to ignore the n of succeed_n's which
4148 currently have n == 0. */
4150 DEBUG_PRINT1 ("EXECUTING no_op.\n");
4154 DEBUG_PRINT1 ("EXECUTING succeed.\n");
4157 /* Match the next n pattern characters exactly. The following
4158 byte in the pattern defines n, and the n bytes after that
4159 are the characters to match. */
4162 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
4164 /* This is written out as an if-else so we don't waste time
4165 testing `translate' inside the loop. */
4171 if ((unsigned char) translate[(unsigned char) *d++]
4172 != (unsigned char) *p++)
4182 if (*d++ != (char) *p++) goto fail;
4186 SET_REGS_MATCHED ();
4190 /* Match any character except possibly a newline or a null. */
4192 DEBUG_PRINT1 ("EXECUTING anychar.\n");
4196 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
4197 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
4200 SET_REGS_MATCHED ();
4201 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
4209 register unsigned char c;
4210 boolean not = (re_opcode_t) *(p - 1) == charset_not;
4212 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
4215 c = TRANSLATE (*d); /* The character to match. */
4217 /* Cast to `unsigned' instead of `unsigned char' in case the
4218 bit list is a full 32 bytes long. */
4219 if (c < (unsigned) (*p * BYTEWIDTH)
4220 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4225 if (!not) goto fail;
4227 SET_REGS_MATCHED ();
4233 /* The beginning of a group is represented by start_memory.
4234 The arguments are the register number in the next byte, and the
4235 number of groups inner to this one in the next. The text
4236 matched within the group is recorded (in the internal
4237 registers data structure) under the register number. */
4239 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
4241 /* Find out if this group can match the empty string. */
4242 p1 = p; /* To send to group_match_null_string_p. */
4244 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
4245 REG_MATCH_NULL_STRING_P (reg_info[*p])
4246 = group_match_null_string_p (&p1, pend, reg_info);
4248 /* Save the position in the string where we were the last time
4249 we were at this open-group operator in case the group is
4250 operated upon by a repetition operator, e.g., with `(a*)*b'
4251 against `ab'; then we want to ignore where we are now in
4252 the string in case this attempt to match fails. */
4253 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4254 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
4256 DEBUG_PRINT2 (" old_regstart: %d\n",
4257 POINTER_TO_OFFSET (old_regstart[*p]));
4260 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
4262 IS_ACTIVE (reg_info[*p]) = 1;
4263 MATCHED_SOMETHING (reg_info[*p]) = 0;
4265 /* Clear this whenever we change the register activity status. */
4266 set_regs_matched_done = 0;
4268 /* This is the new highest active register. */
4269 highest_active_reg = *p;
4271 /* If nothing was active before, this is the new lowest active
4273 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4274 lowest_active_reg = *p;
4276 /* Move past the register number and inner group count. */
4278 just_past_start_mem = p;
4283 /* The stop_memory opcode represents the end of a group. Its
4284 arguments are the same as start_memory's: the register
4285 number, and the number of inner groups. */
4287 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
4289 /* We need to save the string position the last time we were at
4290 this close-group operator in case the group is operated
4291 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
4292 against `aba'; then we want to ignore where we are now in
4293 the string in case this attempt to match fails. */
4294 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4295 ? REG_UNSET (regend[*p]) ? d : regend[*p]
4297 DEBUG_PRINT2 (" old_regend: %d\n",
4298 POINTER_TO_OFFSET (old_regend[*p]));
4301 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
4303 /* This register isn't active anymore. */
4304 IS_ACTIVE (reg_info[*p]) = 0;
4306 /* Clear this whenever we change the register activity status. */
4307 set_regs_matched_done = 0;
4309 /* If this was the only register active, nothing is active
4311 if (lowest_active_reg == highest_active_reg)
4313 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4314 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4317 { /* We must scan for the new highest active register, since
4318 it isn't necessarily one less than now: consider
4319 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
4320 new highest active register is 1. */
4321 unsigned char r = *p - 1;
4322 while (r > 0 && !IS_ACTIVE (reg_info[r]))
4325 /* If we end up at register zero, that means that we saved
4326 the registers as the result of an `on_failure_jump', not
4327 a `start_memory', and we jumped to past the innermost
4328 `stop_memory'. For example, in ((.)*) we save
4329 registers 1 and 2 as a result of the *, but when we pop
4330 back to the second ), we are at the stop_memory 1.
4331 Thus, nothing is active. */
4334 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4335 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4338 highest_active_reg = r;
4341 /* If just failed to match something this time around with a
4342 group that's operated on by a repetition operator, try to
4343 force exit from the ``loop'', and restore the register
4344 information for this group that we had before trying this
4346 if ((!MATCHED_SOMETHING (reg_info[*p])
4347 || just_past_start_mem == p - 1)
4350 boolean is_a_jump_n = false;
4354 switch ((re_opcode_t) *p1++)
4358 case pop_failure_jump:
4359 case maybe_pop_jump:
4361 case dummy_failure_jump:
4362 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4372 /* If the next operation is a jump backwards in the pattern
4373 to an on_failure_jump right before the start_memory
4374 corresponding to this stop_memory, exit from the loop
4375 by forcing a failure after pushing on the stack the
4376 on_failure_jump's jump in the pattern, and d. */
4377 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
4378 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
4380 /* If this group ever matched anything, then restore
4381 what its registers were before trying this last
4382 failed match, e.g., with `(a*)*b' against `ab' for
4383 regstart[1], and, e.g., with `((a*)*(b*)*)*'
4384 against `aba' for regend[3].
4386 Also restore the registers for inner groups for,
4387 e.g., `((a*)(b*))*' against `aba' (register 3 would
4388 otherwise get trashed). */
4390 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
4394 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
4396 /* Restore this and inner groups' (if any) registers. */
4397 for (r = *p; r < (unsigned) *p + (unsigned) *(p + 1);
4400 regstart[r] = old_regstart[r];
4402 /* xx why this test? */
4403 if (old_regend[r] >= regstart[r])
4404 regend[r] = old_regend[r];
4408 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4409 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
4415 /* Move past the register number and the inner group count. */
4420 /* \<digit> has been turned into a `duplicate' command which is
4421 followed by the numeric value of <digit> as the register number. */
4424 register const char *d2, *dend2;
4425 int regno = *p++; /* Get which register to match against. */
4426 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
4428 /* Can't back reference a group which we've never matched. */
4429 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
4432 /* Where in input to try to start matching. */
4433 d2 = regstart[regno];
4435 /* Where to stop matching; if both the place to start and
4436 the place to stop matching are in the same string, then
4437 set to the place to stop, otherwise, for now have to use
4438 the end of the first string. */
4440 dend2 = ((FIRST_STRING_P (regstart[regno])
4441 == FIRST_STRING_P (regend[regno]))
4442 ? regend[regno] : end_match_1);
4445 /* If necessary, advance to next segment in register
4449 if (dend2 == end_match_2) break;
4450 if (dend2 == regend[regno]) break;
4452 /* End of string1 => advance to string2. */
4454 dend2 = regend[regno];
4456 /* At end of register contents => success */
4457 if (d2 == dend2) break;
4459 /* If necessary, advance to next segment in data. */
4462 /* How many characters left in this segment to match. */
4465 /* Want how many consecutive characters we can match in
4466 one shot, so, if necessary, adjust the count. */
4467 if (mcnt > dend2 - d2)
4470 /* Compare that many; failure if mismatch, else move
4473 ? bcmp_translate (d, d2, mcnt, translate)
4474 : memcmp (d, d2, mcnt))
4476 d += mcnt, d2 += mcnt;
4478 /* Do this because we've match some characters. */
4479 SET_REGS_MATCHED ();
4485 /* begline matches the empty string at the beginning of the string
4486 (unless `not_bol' is set in `bufp'), and, if
4487 `newline_anchor' is set, after newlines. */
4489 DEBUG_PRINT1 ("EXECUTING begline.\n");
4491 if (AT_STRINGS_BEG (d))
4493 if (!bufp->not_bol) break;
4495 else if (d[-1] == '\n' && bufp->newline_anchor)
4499 /* In all other cases, we fail. */
4503 /* endline is the dual of begline. */
4505 DEBUG_PRINT1 ("EXECUTING endline.\n");
4507 if (AT_STRINGS_END (d))
4509 if (!bufp->not_eol) break;
4512 /* We have to ``prefetch'' the next character. */
4513 else if ((d == end1 ? *string2 : *d) == '\n'
4514 && bufp->newline_anchor)
4521 /* Match at the very beginning of the data. */
4523 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4524 if (AT_STRINGS_BEG (d))
4529 /* Match at the very end of the data. */
4531 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4532 if (AT_STRINGS_END (d))
4537 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
4538 pushes NULL as the value for the string on the stack. Then
4539 `pop_failure_point' will keep the current value for the
4540 string, instead of restoring it. To see why, consider
4541 matching `foo\nbar' against `.*\n'. The .* matches the foo;
4542 then the . fails against the \n. But the next thing we want
4543 to do is match the \n against the \n; if we restored the
4544 string value, we would be back at the foo.
4546 Because this is used only in specific cases, we don't need to
4547 check all the things that `on_failure_jump' does, to make
4548 sure the right things get saved on the stack. Hence we don't
4549 share its code. The only reason to push anything on the
4550 stack at all is that otherwise we would have to change
4551 `anychar's code to do something besides goto fail in this
4552 case; that seems worse than this. */
4553 case on_failure_keep_string_jump:
4554 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4556 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4558 DEBUG_PRINT3 (" %d (to %p):\n", mcnt, p + mcnt);
4560 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4563 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4567 /* Uses of on_failure_jump:
4569 Each alternative starts with an on_failure_jump that points
4570 to the beginning of the next alternative. Each alternative
4571 except the last ends with a jump that in effect jumps past
4572 the rest of the alternatives. (They really jump to the
4573 ending jump of the following alternative, because tensioning
4574 these jumps is a hassle.)
4576 Repeats start with an on_failure_jump that points past both
4577 the repetition text and either the following jump or
4578 pop_failure_jump back to this on_failure_jump. */
4579 case on_failure_jump:
4581 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4583 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4585 DEBUG_PRINT3 (" %d (to %p)", mcnt, p + mcnt);
4587 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4590 /* If this on_failure_jump comes right before a group (i.e.,
4591 the original * applied to a group), save the information
4592 for that group and all inner ones, so that if we fail back
4593 to this point, the group's information will be correct.
4594 For example, in \(a*\)*\1, we need the preceding group,
4595 and in \(zz\(a*\)b*\)\2, we need the inner group. */
4597 /* We can't use `p' to check ahead because we push
4598 a failure point to `p + mcnt' after we do this. */
4601 /* We need to skip no_op's before we look for the
4602 start_memory in case this on_failure_jump is happening as
4603 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
4605 while (p1 < pend && (re_opcode_t) *p1 == no_op)
4608 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
4610 /* We have a new highest active register now. This will
4611 get reset at the start_memory we are about to get to,
4612 but we will have saved all the registers relevant to
4613 this repetition op, as described above. */
4614 highest_active_reg = *(p1 + 1) + *(p1 + 2);
4615 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4616 lowest_active_reg = *(p1 + 1);
4619 DEBUG_PRINT1 (":\n");
4620 PUSH_FAILURE_POINT (p + mcnt, d, -2);
4624 /* A smart repeat ends with `maybe_pop_jump'.
4625 We change it to either `pop_failure_jump' or `jump'. */
4626 case maybe_pop_jump:
4627 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4628 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4630 register unsigned char *p2 = p;
4632 /* Compare the beginning of the repeat with what in the
4633 pattern follows its end. If we can establish that there
4634 is nothing that they would both match, i.e., that we
4635 would have to backtrack because of (as in, e.g., `a*a')
4636 then we can change to pop_failure_jump, because we'll
4637 never have to backtrack.
4639 This is not true in the case of alternatives: in
4640 `(a|ab)*' we do need to backtrack to the `ab' alternative
4641 (e.g., if the string was `ab'). But instead of trying to
4642 detect that here, the alternative has put on a dummy
4643 failure point which is what we will end up popping. */
4645 /* Skip over open/close-group commands.
4646 If what follows this loop is a ...+ construct,
4647 look at what begins its body, since we will have to
4648 match at least one of that. */
4652 && ((re_opcode_t) *p2 == stop_memory
4653 || (re_opcode_t) *p2 == start_memory))
4655 else if (p2 + 6 < pend
4656 && (re_opcode_t) *p2 == dummy_failure_jump)
4663 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4664 to the `maybe_finalize_jump' of this case. Examine what
4667 /* If we're at the end of the pattern, we can change. */
4670 /* Consider what happens when matching ":\(.*\)"
4671 against ":/". I don't really understand this code
4673 p[-3] = (unsigned char) pop_failure_jump;
4675 (" End of pattern: change to `pop_failure_jump'.\n");
4678 else if ((re_opcode_t) *p2 == exactn
4679 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4681 register unsigned char c
4682 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4684 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4686 p[-3] = (unsigned char) pop_failure_jump;
4687 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4691 else if ((re_opcode_t) p1[3] == charset
4692 || (re_opcode_t) p1[3] == charset_not)
4694 int not = (re_opcode_t) p1[3] == charset_not;
4696 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4697 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4700 /* `not' is equal to 1 if c would match, which means
4701 that we can't change to pop_failure_jump. */
4704 p[-3] = (unsigned char) pop_failure_jump;
4705 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4709 else if ((re_opcode_t) *p2 == charset)
4712 register unsigned char c
4713 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4717 if ((re_opcode_t) p1[3] == exactn
4718 && ! ((int) p2[1] * BYTEWIDTH > (int) p1[5]
4719 && (p2[2 + p1[5] / BYTEWIDTH]
4720 & (1 << (p1[5] % BYTEWIDTH)))))
4722 if ((re_opcode_t) p1[3] == exactn
4723 && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
4724 && (p2[2 + p1[4] / BYTEWIDTH]
4725 & (1 << (p1[4] % BYTEWIDTH)))))
4728 p[-3] = (unsigned char) pop_failure_jump;
4729 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4733 else if ((re_opcode_t) p1[3] == charset_not)
4736 /* We win if the charset_not inside the loop
4737 lists every character listed in the charset after. */
4738 for (idx = 0; idx < (int) p2[1]; idx++)
4739 if (! (p2[2 + idx] == 0
4740 || (idx < (int) p1[4]
4741 && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
4746 p[-3] = (unsigned char) pop_failure_jump;
4747 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4750 else if ((re_opcode_t) p1[3] == charset)
4753 /* We win if the charset inside the loop
4754 has no overlap with the one after the loop. */
4756 idx < (int) p2[1] && idx < (int) p1[4];
4758 if ((p2[2 + idx] & p1[5 + idx]) != 0)
4761 if (idx == p2[1] || idx == p1[4])
4763 p[-3] = (unsigned char) pop_failure_jump;
4764 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4769 p -= 2; /* Point at relative address again. */
4770 if ((re_opcode_t) p[-1] != pop_failure_jump)
4772 p[-1] = (unsigned char) jump;
4773 DEBUG_PRINT1 (" Match => jump.\n");
4774 goto unconditional_jump;
4776 /* Note fall through. */
4779 /* The end of a simple repeat has a pop_failure_jump back to
4780 its matching on_failure_jump, where the latter will push a
4781 failure point. The pop_failure_jump takes off failure
4782 points put on by this pop_failure_jump's matching
4783 on_failure_jump; we got through the pattern to here from the
4784 matching on_failure_jump, so didn't fail. */
4785 case pop_failure_jump:
4787 /* We need to pass separate storage for the lowest and
4788 highest registers, even though we don't care about the
4789 actual values. Otherwise, we will restore only one
4790 register from the stack, since lowest will == highest in
4791 `pop_failure_point'. */
4792 active_reg_t dummy_low_reg, dummy_high_reg;
4793 unsigned char *pdummy;
4796 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4797 POP_FAILURE_POINT (sdummy, pdummy,
4798 dummy_low_reg, dummy_high_reg,
4799 reg_dummy, reg_dummy, reg_info_dummy);
4801 /* Note fall through. */
4805 DEBUG_PRINT2 ("\n%p: ", p);
4807 DEBUG_PRINT2 ("\n0x%x: ", p);
4809 /* Note fall through. */
4811 /* Unconditionally jump (without popping any failure points). */
4813 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4814 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4815 p += mcnt; /* Do the jump. */
4817 DEBUG_PRINT2 ("(to %p).\n", p);
4819 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4824 /* We need this opcode so we can detect where alternatives end
4825 in `group_match_null_string_p' et al. */
4827 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4828 goto unconditional_jump;
4831 /* Normally, the on_failure_jump pushes a failure point, which
4832 then gets popped at pop_failure_jump. We will end up at
4833 pop_failure_jump, also, and with a pattern of, say, `a+', we
4834 are skipping over the on_failure_jump, so we have to push
4835 something meaningless for pop_failure_jump to pop. */
4836 case dummy_failure_jump:
4837 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4838 /* It doesn't matter what we push for the string here. What
4839 the code at `fail' tests is the value for the pattern. */
4840 PUSH_FAILURE_POINT (NULL, NULL, -2);
4841 goto unconditional_jump;
4844 /* At the end of an alternative, we need to push a dummy failure
4845 point in case we are followed by a `pop_failure_jump', because
4846 we don't want the failure point for the alternative to be
4847 popped. For example, matching `(a|ab)*' against `aab'
4848 requires that we match the `ab' alternative. */
4849 case push_dummy_failure:
4850 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4851 /* See comments just above at `dummy_failure_jump' about the
4853 PUSH_FAILURE_POINT (NULL, NULL, -2);
4856 /* Have to succeed matching what follows at least n times.
4857 After that, handle like `on_failure_jump'. */
4859 EXTRACT_NUMBER (mcnt, p + 2);
4860 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4863 /* Originally, this is how many times we HAVE to succeed. */
4868 STORE_NUMBER_AND_INCR (p, mcnt);
4870 DEBUG_PRINT3 (" Setting %p to %d.\n", p - 2, mcnt);
4872 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p - 2, mcnt);
4878 DEBUG_PRINT2 (" Setting two bytes from %p to no_op.\n", p+2);
4880 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4882 p[2] = (unsigned char) no_op;
4883 p[3] = (unsigned char) no_op;
4889 EXTRACT_NUMBER (mcnt, p + 2);
4890 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4892 /* Originally, this is how many times we CAN jump. */
4896 STORE_NUMBER (p + 2, mcnt);
4898 DEBUG_PRINT3 (" Setting %p to %d.\n", p + 2, mcnt);
4900 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p + 2, mcnt);
4902 goto unconditional_jump;
4904 /* If don't have to jump any more, skip over the rest of command. */
4911 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4913 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4915 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4917 DEBUG_PRINT3 (" Setting %p to %d.\n", p1, mcnt);
4919 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4921 STORE_NUMBER (p1, mcnt);
4926 /* The DEC Alpha C compiler 3.x generates incorrect code for the
4927 test WORDCHAR_P (d - 1) != WORDCHAR_P (d) in the expansion of
4928 AT_WORD_BOUNDARY, so this code is disabled. Expanding the
4929 macro and introducing temporary variables works around the bug. */
4932 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4933 if (AT_WORD_BOUNDARY (d))
4938 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4939 if (AT_WORD_BOUNDARY (d))
4945 boolean prevchar, thischar;
4947 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4948 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4951 prevchar = WORDCHAR_P (d - 1);
4952 thischar = WORDCHAR_P (d);
4953 if (prevchar != thischar)
4960 boolean prevchar, thischar;
4962 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4963 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4966 prevchar = WORDCHAR_P (d - 1);
4967 thischar = WORDCHAR_P (d);
4968 if (prevchar != thischar)
4975 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4976 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4981 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4982 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4983 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4989 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4990 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4995 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4996 if (PTR_CHAR_POS ((unsigned char *) d) != point)
5001 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
5002 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
5007 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
5012 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
5016 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
5018 if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
5020 SET_REGS_MATCHED ();
5024 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
5026 goto matchnotsyntax;
5029 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
5033 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
5035 if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
5037 SET_REGS_MATCHED ();
5040 #else /* not emacs */
5042 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
5044 if (!WORDCHAR_P (d))
5046 SET_REGS_MATCHED ();
5051 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
5055 SET_REGS_MATCHED ();
5058 #endif /* not emacs */
5063 continue; /* Successfully executed one pattern command; keep going. */
5066 /* We goto here if a matching operation fails. */
5068 if (!FAIL_STACK_EMPTY ())
5069 { /* A restart point is known. Restore to that state. */
5070 DEBUG_PRINT1 ("\nFAIL:\n");
5071 POP_FAILURE_POINT (d, p,
5072 lowest_active_reg, highest_active_reg,
5073 regstart, regend, reg_info);
5075 /* If this failure point is a dummy, try the next one. */
5079 /* If we failed to the end of the pattern, don't examine *p. */
5083 boolean is_a_jump_n = false;
5085 /* If failed to a backwards jump that's part of a repetition
5086 loop, need to pop this failure point and use the next one. */
5087 switch ((re_opcode_t) *p)
5091 case maybe_pop_jump:
5092 case pop_failure_jump:
5095 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5098 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
5100 && (re_opcode_t) *p1 == on_failure_jump))
5108 if (d >= string1 && d <= end1)
5112 break; /* Matching at this starting point really fails. */
5116 goto restore_best_regs;
5120 return -1; /* Failure to match. */
5123 /* Subroutine definitions for re_match_2. */
5126 /* We are passed P pointing to a register number after a start_memory.
5128 Return true if the pattern up to the corresponding stop_memory can
5129 match the empty string, and false otherwise.
5131 If we find the matching stop_memory, sets P to point to one past its number.
5132 Otherwise, sets P to an undefined byte less than or equal to END.
5134 We don't handle duplicates properly (yet). */
5137 group_match_null_string_p (p, end, reg_info)
5138 unsigned char **p, *end;
5139 register_info_type *reg_info;
5142 /* Point to after the args to the start_memory. */
5143 unsigned char *p1 = *p + 2;
5147 /* Skip over opcodes that can match nothing, and return true or
5148 false, as appropriate, when we get to one that can't, or to the
5149 matching stop_memory. */
5151 switch ((re_opcode_t) *p1)
5153 /* Could be either a loop or a series of alternatives. */
5154 case on_failure_jump:
5156 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5158 /* If the next operation is not a jump backwards in the
5163 /* Go through the on_failure_jumps of the alternatives,
5164 seeing if any of the alternatives cannot match nothing.
5165 The last alternative starts with only a jump,
5166 whereas the rest start with on_failure_jump and end
5167 with a jump, e.g., here is the pattern for `a|b|c':
5169 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
5170 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
5173 So, we have to first go through the first (n-1)
5174 alternatives and then deal with the last one separately. */
5177 /* Deal with the first (n-1) alternatives, which start
5178 with an on_failure_jump (see above) that jumps to right
5179 past a jump_past_alt. */
5181 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
5183 /* `mcnt' holds how many bytes long the alternative
5184 is, including the ending `jump_past_alt' and
5187 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
5191 /* Move to right after this alternative, including the
5195 /* Break if it's the beginning of an n-th alternative
5196 that doesn't begin with an on_failure_jump. */
5197 if ((re_opcode_t) *p1 != on_failure_jump)
5200 /* Still have to check that it's not an n-th
5201 alternative that starts with an on_failure_jump. */
5203 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5204 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
5206 /* Get to the beginning of the n-th alternative. */
5212 /* Deal with the last alternative: go back and get number
5213 of the `jump_past_alt' just before it. `mcnt' contains
5214 the length of the alternative. */
5215 EXTRACT_NUMBER (mcnt, p1 - 2);
5217 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
5220 p1 += mcnt; /* Get past the n-th alternative. */
5226 assert (p1[1] == **p);
5232 if (!common_op_match_null_string_p (&p1, end, reg_info))
5235 } /* while p1 < end */
5238 } /* group_match_null_string_p */
5241 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
5242 It expects P to be the first byte of a single alternative and END one
5243 byte past the last. The alternative can contain groups. */
5246 alt_match_null_string_p (p, end, reg_info)
5247 unsigned char *p, *end;
5248 register_info_type *reg_info;
5251 unsigned char *p1 = p;
5255 /* Skip over opcodes that can match nothing, and break when we get
5256 to one that can't. */
5258 switch ((re_opcode_t) *p1)
5261 case on_failure_jump:
5263 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5268 if (!common_op_match_null_string_p (&p1, end, reg_info))
5271 } /* while p1 < end */
5274 } /* alt_match_null_string_p */
5277 /* Deals with the ops common to group_match_null_string_p and
5278 alt_match_null_string_p.
5280 Sets P to one after the op and its arguments, if any. */
5283 common_op_match_null_string_p (p, end, reg_info)
5284 unsigned char **p, *end;
5285 register_info_type *reg_info;
5290 unsigned char *p1 = *p;
5292 switch ((re_opcode_t) *p1++)
5312 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
5313 ret = group_match_null_string_p (&p1, end, reg_info);
5315 /* Have to set this here in case we're checking a group which
5316 contains a group and a back reference to it. */
5318 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
5319 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
5325 /* If this is an optimized succeed_n for zero times, make the jump. */
5327 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5335 /* Get to the number of times to succeed. */
5337 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5342 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5350 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
5358 /* All other opcodes mean we cannot match the empty string. */
5364 } /* common_op_match_null_string_p */
5367 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
5368 bytes; nonzero otherwise. */
5371 bcmp_translate (s1, s2, len, translate)
5372 const char *s1, *s2;
5374 RE_TRANSLATE_TYPE translate;
5376 register const unsigned char *p1 = (const unsigned char *) s1;
5377 register const unsigned char *p2 = (const unsigned char *) s2;
5380 if (translate[*p1++] != translate[*p2++]) return 1;
5386 /* Entry points for GNU code. */
5388 /* re_compile_pattern is the GNU regular expression compiler: it
5389 compiles PATTERN (of length SIZE) and puts the result in BUFP.
5390 Returns 0 if the pattern was valid, otherwise an error string.
5392 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
5393 are set in BUFP on entry.
5395 We call regex_compile to do the actual compilation. */
5398 re_compile_pattern (pattern, length, bufp)
5399 const char *pattern;
5401 struct re_pattern_buffer *bufp;
5405 /* GNU code is written to assume at least RE_NREGS registers will be set
5406 (and at least one extra will be -1). */
5407 bufp->regs_allocated = REGS_UNALLOCATED;
5409 /* And GNU code determines whether or not to get register information
5410 by passing null for the REGS argument to re_match, etc., not by
5414 /* Match anchors at newline. */
5415 bufp->newline_anchor = 1;
5417 ret = regex_compile (pattern, length, re_syntax_options, bufp);
5421 return gettext (re_error_msgid[(int) ret]);
5424 weak_alias (__re_compile_pattern, re_compile_pattern)
5427 /* Entry points compatible with 4.2 BSD regex library. We don't define
5428 them unless specifically requested. */
5430 #if defined _REGEX_RE_COMP || defined _LIBC
5432 /* BSD has one and only one pattern buffer. */
5433 static struct re_pattern_buffer re_comp_buf;
5437 /* Make these definitions weak in libc, so POSIX programs can redefine
5438 these names if they don't use our functions, and still use
5439 regcomp/regexec below without link errors. */
5449 if (!re_comp_buf.buffer)
5450 return gettext ("No previous regular expression");
5454 if (!re_comp_buf.buffer)
5456 re_comp_buf.buffer = (unsigned char *) malloc (200);
5457 if (re_comp_buf.buffer == NULL)
5458 return (char *) gettext (re_error_msgid[(int) REG_ESPACE]);
5459 re_comp_buf.allocated = 200;
5461 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
5462 if (re_comp_buf.fastmap == NULL)
5463 return (char *) gettext (re_error_msgid[(int) REG_ESPACE]);
5466 /* Since `re_exec' always passes NULL for the `regs' argument, we
5467 don't need to initialize the pattern buffer fields which affect it. */
5469 /* Match anchors at newlines. */
5470 re_comp_buf.newline_anchor = 1;
5472 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
5477 /* Yes, we're discarding `const' here if !HAVE_LIBINTL. */
5478 return (char *) gettext (re_error_msgid[(int) ret]);
5489 const int len = strlen (s);
5491 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
5494 #endif /* _REGEX_RE_COMP */
5496 /* POSIX.2 functions. Don't define these for Emacs. */
5500 /* regcomp takes a regular expression as a string and compiles it.
5502 PREG is a regex_t *. We do not expect any fields to be initialized,
5503 since POSIX says we shouldn't. Thus, we set
5505 `buffer' to the compiled pattern;
5506 `used' to the length of the compiled pattern;
5507 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
5508 REG_EXTENDED bit in CFLAGS is set; otherwise, to
5509 RE_SYNTAX_POSIX_BASIC;
5510 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
5511 `fastmap' to an allocated space for the fastmap;
5512 `fastmap_accurate' to 1;
5513 `re_nsub' to the number of subexpressions in PATTERN.
5515 PATTERN is the address of the pattern string.
5517 CFLAGS is a series of bits which affect compilation.
5519 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
5520 use POSIX basic syntax.
5522 If REG_NEWLINE is set, then . and [^...] don't match newline.
5523 Also, regexec will try a match beginning after every newline.
5525 If REG_ICASE is set, then we considers upper- and lowercase
5526 versions of letters to be equivalent when matching.
5528 If REG_NOSUB is set, then when PREG is passed to regexec, that
5529 routine will report only success or failure, and nothing about the
5532 It returns 0 if it succeeds, nonzero if it doesn't. (See gnu-regex.h for
5533 the return codes and their meanings.) */
5536 regcomp (preg, pattern, cflags)
5538 const char *pattern;
5543 = (cflags & REG_EXTENDED) ?
5544 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
5546 /* regex_compile will allocate the space for the compiled pattern. */
5548 preg->allocated = 0;
5551 /* Try to allocate space for the fastmap. */
5552 preg->fastmap = (char *) malloc (1 << BYTEWIDTH);
5554 if (cflags & REG_ICASE)
5559 = (RE_TRANSLATE_TYPE) malloc (CHAR_SET_SIZE
5560 * sizeof (*(RE_TRANSLATE_TYPE)0));
5561 if (preg->translate == NULL)
5562 return (int) REG_ESPACE;
5564 /* Map uppercase characters to corresponding lowercase ones. */
5565 for (i = 0; i < CHAR_SET_SIZE; i++)
5566 preg->translate[i] = TOLOWER (i);
5569 preg->translate = NULL;
5571 /* If REG_NEWLINE is set, newlines are treated differently. */
5572 if (cflags & REG_NEWLINE)
5573 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
5574 syntax &= ~RE_DOT_NEWLINE;
5575 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
5576 /* It also changes the matching behavior. */
5577 preg->newline_anchor = 1;
5580 preg->newline_anchor = 0;
5582 preg->no_sub = !!(cflags & REG_NOSUB);
5584 /* POSIX says a null character in the pattern terminates it, so we
5585 can use strlen here in compiling the pattern. */
5586 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
5588 /* POSIX doesn't distinguish between an unmatched open-group and an
5589 unmatched close-group: both are REG_EPAREN. */
5590 if (ret == REG_ERPAREN) ret = REG_EPAREN;
5592 if (ret == REG_NOERROR && preg->fastmap)
5594 /* Compute the fastmap now, since regexec cannot modify the pattern
5596 if (re_compile_fastmap (preg) == -2)
5598 /* Some error occured while computing the fastmap, just forget
5600 free (preg->fastmap);
5601 preg->fastmap = NULL;
5608 weak_alias (__regcomp, regcomp)
5612 /* regexec searches for a given pattern, specified by PREG, in the
5615 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
5616 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
5617 least NMATCH elements, and we set them to the offsets of the
5618 corresponding matched substrings.
5620 EFLAGS specifies `execution flags' which affect matching: if
5621 REG_NOTBOL is set, then ^ does not match at the beginning of the
5622 string; if REG_NOTEOL is set, then $ does not match at the end.
5624 We return 0 if we find a match and REG_NOMATCH if not. */
5627 regexec (preg, string, nmatch, pmatch, eflags)
5628 const regex_t *preg;
5631 regmatch_t pmatch[];
5635 struct re_registers regs;
5636 regex_t private_preg;
5637 int len = strlen (string);
5638 boolean want_reg_info = !preg->no_sub && nmatch > 0;
5640 private_preg = *preg;
5642 private_preg.not_bol = !!(eflags & REG_NOTBOL);
5643 private_preg.not_eol = !!(eflags & REG_NOTEOL);
5645 /* The user has told us exactly how many registers to return
5646 information about, via `nmatch'. We have to pass that on to the
5647 matching routines. */
5648 private_preg.regs_allocated = REGS_FIXED;
5652 regs.num_regs = nmatch;
5653 regs.start = TALLOC (nmatch, regoff_t);
5654 regs.end = TALLOC (nmatch, regoff_t);
5655 if (regs.start == NULL || regs.end == NULL)
5656 return (int) REG_NOMATCH;
5659 /* Perform the searching operation. */
5660 ret = re_search (&private_preg, string, len,
5661 /* start: */ 0, /* range: */ len,
5662 want_reg_info ? ®s : (struct re_registers *) 0);
5664 /* Copy the register information to the POSIX structure. */
5671 for (r = 0; r < nmatch; r++)
5673 pmatch[r].rm_so = regs.start[r];
5674 pmatch[r].rm_eo = regs.end[r];
5678 /* If we needed the temporary register info, free the space now. */
5683 /* We want zero return to mean success, unlike `re_search'. */
5684 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5687 weak_alias (__regexec, regexec)
5691 /* Returns a message corresponding to an error code, ERRCODE, returned
5692 from either regcomp or regexec. We don't use PREG here. */
5695 regerror (errcode, preg, errbuf, errbuf_size)
5697 const regex_t *preg;
5706 || errcode >= (int) (sizeof (re_error_msgid)
5707 / sizeof (re_error_msgid[0])))
5708 /* Only error codes returned by the rest of the code should be passed
5709 to this routine. If we are given anything else, or if other regex
5710 code generates an invalid error code, then the program has a bug.
5711 Dump core so we can fix it. */
5714 msg = gettext (re_error_msgid[errcode]);
5716 msg_size = strlen (msg) + 1; /* Includes the null. */
5718 if (errbuf_size != 0)
5720 if (msg_size > errbuf_size)
5722 #if defined HAVE_MEMPCPY || defined _LIBC
5723 *((char *) mempcpy (errbuf, msg, errbuf_size - 1)) = '\0';
5725 memcpy (errbuf, msg, errbuf_size - 1);
5726 errbuf[errbuf_size - 1] = 0;
5730 memcpy (errbuf, msg, msg_size);
5736 weak_alias (__regerror, regerror)
5740 /* Free dynamically allocated space used by PREG. */
5746 if (preg->buffer != NULL)
5747 free (preg->buffer);
5748 preg->buffer = NULL;
5750 preg->allocated = 0;
5753 if (preg->fastmap != NULL)
5754 free (preg->fastmap);
5755 preg->fastmap = NULL;
5756 preg->fastmap_accurate = 0;
5758 if (preg->translate != NULL)
5759 free (preg->translate);
5760 preg->translate = NULL;
5763 weak_alias (__regfree, regfree)
5766 #endif /* not emacs */
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