1 /* Extended regular expression matching and search library,
3 (Implements POSIX draft P10003.2/D11.2, except for
4 internationalization features.)
6 Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
23 /* AIX requires this to be the first thing in the file. */
24 #if defined (_AIX) && !defined (REGEX_MALLOC)
35 /* We need this for `regex.h', and perhaps for the Emacs include files. */
36 #include <sys/types.h>
38 /* This is for other GNU distributions with internationalized messages. */
39 #if HAVE_LIBINTL_H || defined (_LIBC)
42 # define gettext(msgid) (msgid)
46 /* This define is so xgettext can find the internationalizable
48 #define gettext_noop(String) String
51 /* The `emacs' switch turns on certain matching commands
52 that make sense only in Emacs. */
61 /* If we are not linking with Emacs proper,
62 we can't use the relocating allocator
63 even if config.h says that we can. */
66 #if defined (STDC_HEADERS) || defined (_LIBC)
73 /* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
74 If nothing else has been done, use the method below. */
75 #ifdef INHIBIT_STRING_HEADER
76 #if !(defined (HAVE_BZERO) && defined (HAVE_BCOPY))
77 #if !defined (bzero) && !defined (bcopy)
78 #undef INHIBIT_STRING_HEADER
83 /* This is the normal way of making sure we have a bcopy and a bzero.
84 This is used in most programs--a few other programs avoid this
85 by defining INHIBIT_STRING_HEADER. */
86 #ifndef INHIBIT_STRING_HEADER
87 #if defined (HAVE_STRING_H) || defined (STDC_HEADERS) || defined (_LIBC)
90 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
93 #define bcopy(s, d, n) memcpy ((d), (s), (n))
96 #define bzero(s, n) memset ((s), 0, (n))
103 /* Define the syntax stuff for \<, \>, etc. */
105 /* This must be nonzero for the wordchar and notwordchar pattern
106 commands in re_match_2. */
111 #ifdef SWITCH_ENUM_BUG
112 #define SWITCH_ENUM_CAST(x) ((int)(x))
114 #define SWITCH_ENUM_CAST(x) (x)
119 extern char *re_syntax_table;
121 #else /* not SYNTAX_TABLE */
123 /* How many characters in the character set. */
124 #define CHAR_SET_SIZE 256
126 static char re_syntax_table[CHAR_SET_SIZE];
137 bzero (re_syntax_table, sizeof re_syntax_table);
139 for (c = 'a'; c <= 'z'; c++)
140 re_syntax_table[c] = Sword;
142 for (c = 'A'; c <= 'Z'; c++)
143 re_syntax_table[c] = Sword;
145 for (c = '0'; c <= '9'; c++)
146 re_syntax_table[c] = Sword;
148 re_syntax_table['_'] = Sword;
153 #endif /* not SYNTAX_TABLE */
155 #define SYNTAX(c) re_syntax_table[c]
157 #endif /* not emacs */
159 /* Get the interface, including the syntax bits. */
162 /* isalpha etc. are used for the character classes. */
165 /* Jim Meyering writes:
167 "... Some ctype macros are valid only for character codes that
168 isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
169 using /bin/cc or gcc but without giving an ansi option). So, all
170 ctype uses should be through macros like ISPRINT... If
171 STDC_HEADERS is defined, then autoconf has verified that the ctype
172 macros don't need to be guarded with references to isascii. ...
173 Defining isascii to 1 should let any compiler worth its salt
174 eliminate the && through constant folding." */
176 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
179 #define ISASCII(c) isascii(c)
183 #define ISBLANK(c) (ISASCII (c) && isblank (c))
185 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
188 #define ISGRAPH(c) (ISASCII (c) && isgraph (c))
190 #define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
193 #define ISPRINT(c) (ISASCII (c) && isprint (c))
194 #define ISDIGIT(c) (ISASCII (c) && isdigit (c))
195 #define ISALNUM(c) (ISASCII (c) && isalnum (c))
196 #define ISALPHA(c) (ISASCII (c) && isalpha (c))
197 #define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
198 #define ISLOWER(c) (ISASCII (c) && islower (c))
199 #define ISPUNCT(c) (ISASCII (c) && ispunct (c))
200 #define ISSPACE(c) (ISASCII (c) && isspace (c))
201 #define ISUPPER(c) (ISASCII (c) && isupper (c))
202 #define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
205 #define NULL (void *)0
208 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
209 since ours (we hope) works properly with all combinations of
210 machines, compilers, `char' and `unsigned char' argument types.
211 (Per Bothner suggested the basic approach.) */
212 #undef SIGN_EXTEND_CHAR
214 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
215 #else /* not __STDC__ */
216 /* As in Harbison and Steele. */
217 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
220 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
221 use `alloca' instead of `malloc'. This is because using malloc in
222 re_search* or re_match* could cause memory leaks when C-g is used in
223 Emacs; also, malloc is slower and causes storage fragmentation. On
224 the other hand, malloc is more portable, and easier to debug.
226 Because we sometimes use alloca, some routines have to be macros,
227 not functions -- `alloca'-allocated space disappears at the end of the
228 function it is called in. */
232 #define REGEX_ALLOCATE malloc
233 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
234 #define REGEX_FREE free
236 #else /* not REGEX_MALLOC */
238 /* Emacs already defines alloca, sometimes. */
241 /* Make alloca work the best possible way. */
243 #define alloca __builtin_alloca
244 #else /* not __GNUC__ */
247 #else /* not __GNUC__ or HAVE_ALLOCA_H */
248 #if 0 /* It is a bad idea to declare alloca. We always cast the result. */
249 #ifndef _AIX /* Already did AIX, up at the top. */
251 #endif /* not _AIX */
253 #endif /* not HAVE_ALLOCA_H */
254 #endif /* not __GNUC__ */
256 #endif /* not alloca */
258 #define REGEX_ALLOCATE alloca
260 /* Assumes a `char *destination' variable. */
261 #define REGEX_REALLOCATE(source, osize, nsize) \
262 (destination = (char *) alloca (nsize), \
263 bcopy (source, destination, osize), \
266 /* No need to do anything to free, after alloca. */
267 #define REGEX_FREE(arg) ((void)0) /* Do nothing! But inhibit gcc warning. */
269 #endif /* not REGEX_MALLOC */
271 /* Define how to allocate the failure stack. */
273 #if defined (REL_ALLOC) && defined (REGEX_MALLOC)
275 #define REGEX_ALLOCATE_STACK(size) \
276 r_alloc (&failure_stack_ptr, (size))
277 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
278 r_re_alloc (&failure_stack_ptr, (nsize))
279 #define REGEX_FREE_STACK(ptr) \
280 r_alloc_free (&failure_stack_ptr)
282 #else /* not using relocating allocator */
286 #define REGEX_ALLOCATE_STACK malloc
287 #define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
288 #define REGEX_FREE_STACK free
290 #else /* not REGEX_MALLOC */
292 #define REGEX_ALLOCATE_STACK alloca
294 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
295 REGEX_REALLOCATE (source, osize, nsize)
296 /* No need to explicitly free anything. */
297 #define REGEX_FREE_STACK(arg)
299 #endif /* not REGEX_MALLOC */
300 #endif /* not using relocating allocator */
303 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
304 `string1' or just past its end. This works if PTR is NULL, which is
306 #define FIRST_STRING_P(ptr) \
307 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
309 /* (Re)Allocate N items of type T using malloc, or fail. */
310 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
311 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
312 #define RETALLOC_IF(addr, n, t) \
313 if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
314 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
316 #define BYTEWIDTH 8 /* In bits. */
318 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
322 #define MAX(a, b) ((a) > (b) ? (a) : (b))
323 #define MIN(a, b) ((a) < (b) ? (a) : (b))
325 typedef char boolean;
329 static int re_match_2_internal ();
331 /* These are the command codes that appear in compiled regular
332 expressions. Some opcodes are followed by argument bytes. A
333 command code can specify any interpretation whatsoever for its
334 arguments. Zero bytes may appear in the compiled regular expression. */
340 /* Succeed right away--no more backtracking. */
343 /* Followed by one byte giving n, then by n literal bytes. */
346 /* Matches any (more or less) character. */
349 /* Matches any one char belonging to specified set. First
350 following byte is number of bitmap bytes. Then come bytes
351 for a bitmap saying which chars are in. Bits in each byte
352 are ordered low-bit-first. A character is in the set if its
353 bit is 1. A character too large to have a bit in the map is
354 automatically not in the set. */
357 /* Same parameters as charset, but match any character that is
358 not one of those specified. */
361 /* Start remembering the text that is matched, for storing in a
362 register. Followed by one byte with the register number, in
363 the range 0 to one less than the pattern buffer's re_nsub
364 field. Then followed by one byte with the number of groups
365 inner to this one. (This last has to be part of the
366 start_memory only because we need it in the on_failure_jump
370 /* Stop remembering the text that is matched and store it in a
371 memory register. Followed by one byte with the register
372 number, in the range 0 to one less than `re_nsub' in the
373 pattern buffer, and one byte with the number of inner groups,
374 just like `start_memory'. (We need the number of inner
375 groups here because we don't have any easy way of finding the
376 corresponding start_memory when we're at a stop_memory.) */
379 /* Match a duplicate of something remembered. Followed by one
380 byte containing the register number. */
383 /* Fail unless at beginning of line. */
386 /* Fail unless at end of line. */
389 /* Succeeds if at beginning of buffer (if emacs) or at beginning
390 of string to be matched (if not). */
393 /* Analogously, for end of buffer/string. */
396 /* Followed by two byte relative address to which to jump. */
399 /* Same as jump, but marks the end of an alternative. */
402 /* Followed by two-byte relative address of place to resume at
403 in case of failure. */
406 /* Like on_failure_jump, but pushes a placeholder instead of the
407 current string position when executed. */
408 on_failure_keep_string_jump,
410 /* Throw away latest failure point and then jump to following
411 two-byte relative address. */
414 /* Change to pop_failure_jump if know won't have to backtrack to
415 match; otherwise change to jump. This is used to jump
416 back to the beginning of a repeat. If what follows this jump
417 clearly won't match what the repeat does, such that we can be
418 sure that there is no use backtracking out of repetitions
419 already matched, then we change it to a pop_failure_jump.
420 Followed by two-byte address. */
423 /* Jump to following two-byte address, and push a dummy failure
424 point. This failure point will be thrown away if an attempt
425 is made to use it for a failure. A `+' construct makes this
426 before the first repeat. Also used as an intermediary kind
427 of jump when compiling an alternative. */
430 /* Push a dummy failure point and continue. Used at the end of
434 /* Followed by two-byte relative address and two-byte number n.
435 After matching N times, jump to the address upon failure. */
438 /* Followed by two-byte relative address, and two-byte number n.
439 Jump to the address N times, then fail. */
442 /* Set the following two-byte relative address to the
443 subsequent two-byte number. The address *includes* the two
447 wordchar, /* Matches any word-constituent character. */
448 notwordchar, /* Matches any char that is not a word-constituent. */
450 wordbeg, /* Succeeds if at word beginning. */
451 wordend, /* Succeeds if at word end. */
453 wordbound, /* Succeeds if at a word boundary. */
454 notwordbound /* Succeeds if not at a word boundary. */
457 ,before_dot, /* Succeeds if before point. */
458 at_dot, /* Succeeds if at point. */
459 after_dot, /* Succeeds if after point. */
461 /* Matches any character whose syntax is specified. Followed by
462 a byte which contains a syntax code, e.g., Sword. */
465 /* Matches any character whose syntax is not that specified. */
470 /* Common operations on the compiled pattern. */
472 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
474 #define STORE_NUMBER(destination, number) \
476 (destination)[0] = (number) & 0377; \
477 (destination)[1] = (number) >> 8; \
480 /* Same as STORE_NUMBER, except increment DESTINATION to
481 the byte after where the number is stored. Therefore, DESTINATION
482 must be an lvalue. */
484 #define STORE_NUMBER_AND_INCR(destination, number) \
486 STORE_NUMBER (destination, number); \
487 (destination) += 2; \
490 /* Put into DESTINATION a number stored in two contiguous bytes starting
493 #define EXTRACT_NUMBER(destination, source) \
495 (destination) = *(source) & 0377; \
496 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
501 extract_number (dest, source)
503 unsigned char *source;
505 int temp = SIGN_EXTEND_CHAR (*(source + 1));
506 *dest = *source & 0377;
510 #ifndef EXTRACT_MACROS /* To debug the macros. */
511 #undef EXTRACT_NUMBER
512 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
513 #endif /* not EXTRACT_MACROS */
517 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
518 SOURCE must be an lvalue. */
520 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
522 EXTRACT_NUMBER (destination, source); \
528 extract_number_and_incr (destination, source)
530 unsigned char **source;
532 extract_number (destination, *source);
536 #ifndef EXTRACT_MACROS
537 #undef EXTRACT_NUMBER_AND_INCR
538 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
539 extract_number_and_incr (&dest, &src)
540 #endif /* not EXTRACT_MACROS */
544 /* If DEBUG is defined, Regex prints many voluminous messages about what
545 it is doing (if the variable `debug' is nonzero). If linked with the
546 main program in `iregex.c', you can enter patterns and strings
547 interactively. And if linked with the main program in `main.c' and
548 the other test files, you can run the already-written tests. */
552 /* We use standard I/O for debugging. */
555 /* It is useful to test things that ``must'' be true when debugging. */
558 static int debug = 0;
560 #define DEBUG_STATEMENT(e) e
561 #define DEBUG_PRINT1(x) if (debug) printf (x)
562 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
563 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
564 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
565 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
566 if (debug) print_partial_compiled_pattern (s, e)
567 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
568 if (debug) print_double_string (w, s1, sz1, s2, sz2)
571 /* Print the fastmap in human-readable form. */
574 print_fastmap (fastmap)
577 unsigned was_a_range = 0;
580 while (i < (1 << BYTEWIDTH))
586 while (i < (1 << BYTEWIDTH) && fastmap[i])
602 /* Print a compiled pattern string in human-readable form, starting at
603 the START pointer into it and ending just before the pointer END. */
606 print_partial_compiled_pattern (start, end)
607 unsigned char *start;
611 unsigned char *p = start;
612 unsigned char *pend = end;
620 /* Loop over pattern commands. */
623 printf ("%d:\t", p - start);
625 switch ((re_opcode_t) *p++)
633 printf ("/exactn/%d", mcnt);
644 printf ("/start_memory/%d/%d", mcnt, *p++);
649 printf ("/stop_memory/%d/%d", mcnt, *p++);
653 printf ("/duplicate/%d", *p++);
663 register int c, last = -100;
664 register int in_range = 0;
666 printf ("/charset [%s",
667 (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
669 assert (p + *p < pend);
671 for (c = 0; c < 256; c++)
673 && (p[1 + (c/8)] & (1 << (c % 8))))
675 /* Are we starting a range? */
676 if (last + 1 == c && ! in_range)
681 /* Have we broken a range? */
682 else if (last + 1 != c && in_range)
711 case on_failure_jump:
712 extract_number_and_incr (&mcnt, &p);
713 printf ("/on_failure_jump to %d", p + mcnt - start);
716 case on_failure_keep_string_jump:
717 extract_number_and_incr (&mcnt, &p);
718 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
721 case dummy_failure_jump:
722 extract_number_and_incr (&mcnt, &p);
723 printf ("/dummy_failure_jump to %d", p + mcnt - start);
726 case push_dummy_failure:
727 printf ("/push_dummy_failure");
731 extract_number_and_incr (&mcnt, &p);
732 printf ("/maybe_pop_jump to %d", p + mcnt - start);
735 case pop_failure_jump:
736 extract_number_and_incr (&mcnt, &p);
737 printf ("/pop_failure_jump to %d", p + mcnt - start);
741 extract_number_and_incr (&mcnt, &p);
742 printf ("/jump_past_alt to %d", p + mcnt - start);
746 extract_number_and_incr (&mcnt, &p);
747 printf ("/jump to %d", p + mcnt - start);
751 extract_number_and_incr (&mcnt, &p);
752 extract_number_and_incr (&mcnt2, &p);
753 printf ("/succeed_n to %d, %d times", p + mcnt - start, mcnt2);
757 extract_number_and_incr (&mcnt, &p);
758 extract_number_and_incr (&mcnt2, &p);
759 printf ("/jump_n to %d, %d times", p + mcnt - start, mcnt2);
763 extract_number_and_incr (&mcnt, &p);
764 extract_number_and_incr (&mcnt2, &p);
765 printf ("/set_number_at location %d to %d", p + mcnt - start, mcnt2);
769 printf ("/wordbound");
773 printf ("/notwordbound");
785 printf ("/before_dot");
793 printf ("/after_dot");
797 printf ("/syntaxspec");
799 printf ("/%d", mcnt);
803 printf ("/notsyntaxspec");
805 printf ("/%d", mcnt);
810 printf ("/wordchar");
814 printf ("/notwordchar");
826 printf ("?%d", *(p-1));
832 printf ("%d:\tend of pattern.\n", p - start);
837 print_compiled_pattern (bufp)
838 struct re_pattern_buffer *bufp;
840 unsigned char *buffer = bufp->buffer;
842 print_partial_compiled_pattern (buffer, buffer + bufp->used);
843 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
845 if (bufp->fastmap_accurate && bufp->fastmap)
847 printf ("fastmap: ");
848 print_fastmap (bufp->fastmap);
851 printf ("re_nsub: %d\t", bufp->re_nsub);
852 printf ("regs_alloc: %d\t", bufp->regs_allocated);
853 printf ("can_be_null: %d\t", bufp->can_be_null);
854 printf ("newline_anchor: %d\n", bufp->newline_anchor);
855 printf ("no_sub: %d\t", bufp->no_sub);
856 printf ("not_bol: %d\t", bufp->not_bol);
857 printf ("not_eol: %d\t", bufp->not_eol);
858 printf ("syntax: %d\n", bufp->syntax);
859 /* Perhaps we should print the translate table? */
864 print_double_string (where, string1, size1, string2, size2)
877 if (FIRST_STRING_P (where))
879 for (this_char = where - string1; this_char < size1; this_char++)
880 putchar (string1[this_char]);
885 for (this_char = where - string2; this_char < size2; this_char++)
886 putchar (string2[this_char]);
890 #else /* not DEBUG */
895 #define DEBUG_STATEMENT(e)
896 #define DEBUG_PRINT1(x)
897 #define DEBUG_PRINT2(x1, x2)
898 #define DEBUG_PRINT3(x1, x2, x3)
899 #define DEBUG_PRINT4(x1, x2, x3, x4)
900 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
901 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
903 #endif /* not DEBUG */
905 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
906 also be assigned to arbitrarily: each pattern buffer stores its own
907 syntax, so it can be changed between regex compilations. */
908 /* This has no initializer because initialized variables in Emacs
909 become read-only after dumping. */
910 reg_syntax_t re_syntax_options;
913 /* Specify the precise syntax of regexps for compilation. This provides
914 for compatibility for various utilities which historically have
915 different, incompatible syntaxes.
917 The argument SYNTAX is a bit mask comprised of the various bits
918 defined in regex.h. We return the old syntax. */
921 re_set_syntax (syntax)
924 reg_syntax_t ret = re_syntax_options;
926 re_syntax_options = syntax;
930 /* This table gives an error message for each of the error codes listed
931 in regex.h. Obviously the order here has to be same as there.
932 POSIX doesn't require that we do anything for REG_NOERROR,
933 but why not be nice? */
935 static const char *re_error_msgid[] =
937 gettext_noop ("Success"), /* REG_NOERROR */
938 gettext_noop ("No match"), /* REG_NOMATCH */
939 gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
940 gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
941 gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
942 gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
943 gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
944 gettext_noop ("Unmatched [ or [^"), /* REG_EBRACK */
945 gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
946 gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
947 gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
948 gettext_noop ("Invalid range end"), /* REG_ERANGE */
949 gettext_noop ("Memory exhausted"), /* REG_ESPACE */
950 gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
951 gettext_noop ("Premature end of regular expression"), /* REG_EEND */
952 gettext_noop ("Regular expression too big"), /* REG_ESIZE */
953 gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
956 /* Avoiding alloca during matching, to placate r_alloc. */
958 /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
959 searching and matching functions should not call alloca. On some
960 systems, alloca is implemented in terms of malloc, and if we're
961 using the relocating allocator routines, then malloc could cause a
962 relocation, which might (if the strings being searched are in the
963 ralloc heap) shift the data out from underneath the regexp
966 Here's another reason to avoid allocation: Emacs
967 processes input from X in a signal handler; processing X input may
968 call malloc; if input arrives while a matching routine is calling
969 malloc, then we're scrod. But Emacs can't just block input while
970 calling matching routines; then we don't notice interrupts when
971 they come in. So, Emacs blocks input around all regexp calls
972 except the matching calls, which it leaves unprotected, in the
973 faith that they will not malloc. */
975 /* Normally, this is fine. */
976 #define MATCH_MAY_ALLOCATE
978 /* When using GNU C, we are not REALLY using the C alloca, no matter
979 what config.h may say. So don't take precautions for it. */
984 /* The match routines may not allocate if (1) they would do it with malloc
985 and (2) it's not safe for them to use malloc.
986 Note that if REL_ALLOC is defined, matching would not use malloc for the
987 failure stack, but we would still use it for the register vectors;
988 so REL_ALLOC should not affect this. */
989 #if (defined (C_ALLOCA) || defined (REGEX_MALLOC)) && defined (emacs)
990 #undef MATCH_MAY_ALLOCATE
994 /* Failure stack declarations and macros; both re_compile_fastmap and
995 re_match_2 use a failure stack. These have to be macros because of
996 REGEX_ALLOCATE_STACK. */
999 /* Number of failure points for which to initially allocate space
1000 when matching. If this number is exceeded, we allocate more
1001 space, so it is not a hard limit. */
1002 #ifndef INIT_FAILURE_ALLOC
1003 #define INIT_FAILURE_ALLOC 5
1006 /* Roughly the maximum number of failure points on the stack. Would be
1007 exactly that if always used MAX_FAILURE_SPACE each time we failed.
1008 This is a variable only so users of regex can assign to it; we never
1009 change it ourselves. */
1010 #if defined (MATCH_MAY_ALLOCATE)
1011 int re_max_failures = 20000;
1013 int re_max_failures = 2000;
1016 union fail_stack_elt
1018 unsigned char *pointer;
1022 typedef union fail_stack_elt fail_stack_elt_t;
1026 fail_stack_elt_t *stack;
1028 unsigned avail; /* Offset of next open position. */
1031 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
1032 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
1033 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
1036 /* Define macros to initialize and free the failure stack.
1037 Do `return -2' if the alloc fails. */
1039 #ifdef MATCH_MAY_ALLOCATE
1040 #define INIT_FAIL_STACK() \
1042 fail_stack.stack = (fail_stack_elt_t *) \
1043 REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
1045 if (fail_stack.stack == NULL) \
1048 fail_stack.size = INIT_FAILURE_ALLOC; \
1049 fail_stack.avail = 0; \
1052 #define RESET_FAIL_STACK() REGEX_FREE_STACK (fail_stack.stack)
1054 #define INIT_FAIL_STACK() \
1056 fail_stack.avail = 0; \
1059 #define RESET_FAIL_STACK()
1063 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
1065 Return 1 if succeeds, and 0 if either ran out of memory
1066 allocating space for it or it was already too large.
1068 REGEX_REALLOCATE_STACK requires `destination' be declared. */
1070 #define DOUBLE_FAIL_STACK(fail_stack) \
1071 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
1073 : ((fail_stack).stack = (fail_stack_elt_t *) \
1074 REGEX_REALLOCATE_STACK ((fail_stack).stack, \
1075 (fail_stack).size * sizeof (fail_stack_elt_t), \
1076 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
1078 (fail_stack).stack == NULL \
1080 : ((fail_stack).size <<= 1, \
1084 /* Push pointer POINTER on FAIL_STACK.
1085 Return 1 if was able to do so and 0 if ran out of memory allocating
1087 #define PUSH_PATTERN_OP(POINTER, FAIL_STACK) \
1088 ((FAIL_STACK_FULL () \
1089 && !DOUBLE_FAIL_STACK (FAIL_STACK)) \
1091 : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER, \
1094 /* Push a pointer value onto the failure stack.
1095 Assumes the variable `fail_stack'. Probably should only
1096 be called from within `PUSH_FAILURE_POINT'. */
1097 #define PUSH_FAILURE_POINTER(item) \
1098 fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
1100 /* This pushes an integer-valued item onto the failure stack.
1101 Assumes the variable `fail_stack'. Probably should only
1102 be called from within `PUSH_FAILURE_POINT'. */
1103 #define PUSH_FAILURE_INT(item) \
1104 fail_stack.stack[fail_stack.avail++].integer = (item)
1106 /* Push a fail_stack_elt_t value onto the failure stack.
1107 Assumes the variable `fail_stack'. Probably should only
1108 be called from within `PUSH_FAILURE_POINT'. */
1109 #define PUSH_FAILURE_ELT(item) \
1110 fail_stack.stack[fail_stack.avail++] = (item)
1112 /* These three POP... operations complement the three PUSH... operations.
1113 All assume that `fail_stack' is nonempty. */
1114 #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
1115 #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
1116 #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
1118 /* Used to omit pushing failure point id's when we're not debugging. */
1120 #define DEBUG_PUSH PUSH_FAILURE_INT
1121 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT ()
1123 #define DEBUG_PUSH(item)
1124 #define DEBUG_POP(item_addr)
1128 /* Push the information about the state we will need
1129 if we ever fail back to it.
1131 Requires variables fail_stack, regstart, regend, reg_info, and
1132 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
1135 Does `return FAILURE_CODE' if runs out of memory. */
1137 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1139 char *destination; \
1140 /* Must be int, so when we don't save any registers, the arithmetic \
1141 of 0 + -1 isn't done as unsigned. */ \
1144 DEBUG_STATEMENT (failure_id++); \
1145 DEBUG_STATEMENT (nfailure_points_pushed++); \
1146 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1147 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1148 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1150 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
1151 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1153 /* Ensure we have enough space allocated for what we will push. */ \
1154 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1156 if (!DOUBLE_FAIL_STACK (fail_stack)) \
1157 return failure_code; \
1159 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1160 (fail_stack).size); \
1161 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1164 /* Push the info, starting with the registers. */ \
1165 DEBUG_PRINT1 ("\n"); \
1168 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
1171 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
1172 DEBUG_STATEMENT (num_regs_pushed++); \
1174 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1175 PUSH_FAILURE_POINTER (regstart[this_reg]); \
1177 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1178 PUSH_FAILURE_POINTER (regend[this_reg]); \
1180 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
1181 DEBUG_PRINT2 (" match_null=%d", \
1182 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1183 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1184 DEBUG_PRINT2 (" matched_something=%d", \
1185 MATCHED_SOMETHING (reg_info[this_reg])); \
1186 DEBUG_PRINT2 (" ever_matched=%d", \
1187 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1188 DEBUG_PRINT1 ("\n"); \
1189 PUSH_FAILURE_ELT (reg_info[this_reg].word); \
1192 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
1193 PUSH_FAILURE_INT (lowest_active_reg); \
1195 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
1196 PUSH_FAILURE_INT (highest_active_reg); \
1198 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
1199 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1200 PUSH_FAILURE_POINTER (pattern_place); \
1202 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
1203 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1205 DEBUG_PRINT1 ("'\n"); \
1206 PUSH_FAILURE_POINTER (string_place); \
1208 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1209 DEBUG_PUSH (failure_id); \
1212 /* This is the number of items that are pushed and popped on the stack
1213 for each register. */
1214 #define NUM_REG_ITEMS 3
1216 /* Individual items aside from the registers. */
1218 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1220 #define NUM_NONREG_ITEMS 4
1223 /* We push at most this many items on the stack. */
1224 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1226 /* We actually push this many items. */
1227 #define NUM_FAILURE_ITEMS \
1229 ? 0 : highest_active_reg - lowest_active_reg + 1) \
1233 /* How many items can still be added to the stack without overflowing it. */
1234 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1237 /* Pops what PUSH_FAIL_STACK pushes.
1239 We restore into the parameters, all of which should be lvalues:
1240 STR -- the saved data position.
1241 PAT -- the saved pattern position.
1242 LOW_REG, HIGH_REG -- the highest and lowest active registers.
1243 REGSTART, REGEND -- arrays of string positions.
1244 REG_INFO -- array of information about each subexpression.
1246 Also assumes the variables `fail_stack' and (if debugging), `bufp',
1247 `pend', `string1', `size1', `string2', and `size2'. */
1249 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1251 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
1253 const unsigned char *string_temp; \
1255 assert (!FAIL_STACK_EMPTY ()); \
1257 /* Remove failure points and point to how many regs pushed. */ \
1258 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1259 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1260 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1262 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1264 DEBUG_POP (&failure_id); \
1265 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1267 /* If the saved string location is NULL, it came from an \
1268 on_failure_keep_string_jump opcode, and we want to throw away the \
1269 saved NULL, thus retaining our current position in the string. */ \
1270 string_temp = POP_FAILURE_POINTER (); \
1271 if (string_temp != NULL) \
1272 str = (const char *) string_temp; \
1274 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
1275 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1276 DEBUG_PRINT1 ("'\n"); \
1278 pat = (unsigned char *) POP_FAILURE_POINTER (); \
1279 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
1280 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1282 /* Restore register info. */ \
1283 high_reg = (unsigned) POP_FAILURE_INT (); \
1284 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
1286 low_reg = (unsigned) POP_FAILURE_INT (); \
1287 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
1290 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
1292 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
1294 reg_info[this_reg].word = POP_FAILURE_ELT (); \
1295 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
1297 regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1298 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1300 regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1301 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1305 for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \
1307 reg_info[this_reg].word.integer = 0; \
1308 regend[this_reg] = 0; \
1309 regstart[this_reg] = 0; \
1311 highest_active_reg = high_reg; \
1314 set_regs_matched_done = 0; \
1315 DEBUG_STATEMENT (nfailure_points_popped++); \
1316 } /* POP_FAILURE_POINT */
1320 /* Structure for per-register (a.k.a. per-group) information.
1321 Other register information, such as the
1322 starting and ending positions (which are addresses), and the list of
1323 inner groups (which is a bits list) are maintained in separate
1326 We are making a (strictly speaking) nonportable assumption here: that
1327 the compiler will pack our bit fields into something that fits into
1328 the type of `word', i.e., is something that fits into one item on the
1333 fail_stack_elt_t word;
1336 /* This field is one if this group can match the empty string,
1337 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1338 #define MATCH_NULL_UNSET_VALUE 3
1339 unsigned match_null_string_p : 2;
1340 unsigned is_active : 1;
1341 unsigned matched_something : 1;
1342 unsigned ever_matched_something : 1;
1344 } register_info_type;
1346 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1347 #define IS_ACTIVE(R) ((R).bits.is_active)
1348 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1349 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1352 /* Call this when have matched a real character; it sets `matched' flags
1353 for the subexpressions which we are currently inside. Also records
1354 that those subexprs have matched. */
1355 #define SET_REGS_MATCHED() \
1358 if (!set_regs_matched_done) \
1361 set_regs_matched_done = 1; \
1362 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1364 MATCHED_SOMETHING (reg_info[r]) \
1365 = EVER_MATCHED_SOMETHING (reg_info[r]) \
1372 /* Registers are set to a sentinel when they haven't yet matched. */
1373 static char reg_unset_dummy;
1374 #define REG_UNSET_VALUE (®_unset_dummy)
1375 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1377 /* Subroutine declarations and macros for regex_compile. */
1379 static void store_op1 (), store_op2 ();
1380 static void insert_op1 (), insert_op2 ();
1381 static boolean at_begline_loc_p (), at_endline_loc_p ();
1382 static boolean group_in_compile_stack ();
1383 static reg_errcode_t compile_range ();
1385 /* Fetch the next character in the uncompiled pattern---translating it
1386 if necessary. Also cast from a signed character in the constant
1387 string passed to us by the user to an unsigned char that we can use
1388 as an array index (in, e.g., `translate'). */
1390 #define PATFETCH(c) \
1391 do {if (p == pend) return REG_EEND; \
1392 c = (unsigned char) *p++; \
1393 if (translate) c = (unsigned char) translate[c]; \
1397 /* Fetch the next character in the uncompiled pattern, with no
1399 #define PATFETCH_RAW(c) \
1400 do {if (p == pend) return REG_EEND; \
1401 c = (unsigned char) *p++; \
1404 /* Go backwards one character in the pattern. */
1405 #define PATUNFETCH p--
1408 /* If `translate' is non-null, return translate[D], else just D. We
1409 cast the subscript to translate because some data is declared as
1410 `char *', to avoid warnings when a string constant is passed. But
1411 when we use a character as a subscript we must make it unsigned. */
1413 #define TRANSLATE(d) \
1414 (translate ? (char) translate[(unsigned char) (d)] : (d))
1418 /* Macros for outputting the compiled pattern into `buffer'. */
1420 /* If the buffer isn't allocated when it comes in, use this. */
1421 #define INIT_BUF_SIZE 32
1423 /* Make sure we have at least N more bytes of space in buffer. */
1424 #define GET_BUFFER_SPACE(n) \
1425 while (b - bufp->buffer + (n) > bufp->allocated) \
1428 /* Make sure we have one more byte of buffer space and then add C to it. */
1429 #define BUF_PUSH(c) \
1431 GET_BUFFER_SPACE (1); \
1432 *b++ = (unsigned char) (c); \
1436 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1437 #define BUF_PUSH_2(c1, c2) \
1439 GET_BUFFER_SPACE (2); \
1440 *b++ = (unsigned char) (c1); \
1441 *b++ = (unsigned char) (c2); \
1445 /* As with BUF_PUSH_2, except for three bytes. */
1446 #define BUF_PUSH_3(c1, c2, c3) \
1448 GET_BUFFER_SPACE (3); \
1449 *b++ = (unsigned char) (c1); \
1450 *b++ = (unsigned char) (c2); \
1451 *b++ = (unsigned char) (c3); \
1455 /* Store a jump with opcode OP at LOC to location TO. We store a
1456 relative address offset by the three bytes the jump itself occupies. */
1457 #define STORE_JUMP(op, loc, to) \
1458 store_op1 (op, loc, (to) - (loc) - 3)
1460 /* Likewise, for a two-argument jump. */
1461 #define STORE_JUMP2(op, loc, to, arg) \
1462 store_op2 (op, loc, (to) - (loc) - 3, arg)
1464 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1465 #define INSERT_JUMP(op, loc, to) \
1466 insert_op1 (op, loc, (to) - (loc) - 3, b)
1468 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1469 #define INSERT_JUMP2(op, loc, to, arg) \
1470 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
1473 /* This is not an arbitrary limit: the arguments which represent offsets
1474 into the pattern are two bytes long. So if 2^16 bytes turns out to
1475 be too small, many things would have to change. */
1476 #define MAX_BUF_SIZE (1L << 16)
1479 /* Extend the buffer by twice its current size via realloc and
1480 reset the pointers that pointed into the old block to point to the
1481 correct places in the new one. If extending the buffer results in it
1482 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1483 #define EXTEND_BUFFER() \
1485 unsigned char *old_buffer = bufp->buffer; \
1486 if (bufp->allocated == MAX_BUF_SIZE) \
1488 bufp->allocated <<= 1; \
1489 if (bufp->allocated > MAX_BUF_SIZE) \
1490 bufp->allocated = MAX_BUF_SIZE; \
1491 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
1492 if (bufp->buffer == NULL) \
1493 return REG_ESPACE; \
1494 /* If the buffer moved, move all the pointers into it. */ \
1495 if (old_buffer != bufp->buffer) \
1497 b = (b - old_buffer) + bufp->buffer; \
1498 begalt = (begalt - old_buffer) + bufp->buffer; \
1499 if (fixup_alt_jump) \
1500 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1502 laststart = (laststart - old_buffer) + bufp->buffer; \
1503 if (pending_exact) \
1504 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1509 /* Since we have one byte reserved for the register number argument to
1510 {start,stop}_memory, the maximum number of groups we can report
1511 things about is what fits in that byte. */
1512 #define MAX_REGNUM 255
1514 /* But patterns can have more than `MAX_REGNUM' registers. We just
1515 ignore the excess. */
1516 typedef unsigned regnum_t;
1519 /* Macros for the compile stack. */
1521 /* Since offsets can go either forwards or backwards, this type needs to
1522 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1523 typedef int pattern_offset_t;
1527 pattern_offset_t begalt_offset;
1528 pattern_offset_t fixup_alt_jump;
1529 pattern_offset_t inner_group_offset;
1530 pattern_offset_t laststart_offset;
1532 } compile_stack_elt_t;
1537 compile_stack_elt_t *stack;
1539 unsigned avail; /* Offset of next open position. */
1540 } compile_stack_type;
1543 #define INIT_COMPILE_STACK_SIZE 32
1545 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1546 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1548 /* The next available element. */
1549 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1552 /* Set the bit for character C in a list. */
1553 #define SET_LIST_BIT(c) \
1554 (b[((unsigned char) (c)) / BYTEWIDTH] \
1555 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1558 /* Get the next unsigned number in the uncompiled pattern. */
1559 #define GET_UNSIGNED_NUMBER(num) \
1563 while (ISDIGIT (c)) \
1567 num = num * 10 + c - '0'; \
1575 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1577 #define IS_CHAR_CLASS(string) \
1578 (STREQ (string, "alpha") || STREQ (string, "upper") \
1579 || STREQ (string, "lower") || STREQ (string, "digit") \
1580 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1581 || STREQ (string, "space") || STREQ (string, "print") \
1582 || STREQ (string, "punct") || STREQ (string, "graph") \
1583 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1585 #ifndef MATCH_MAY_ALLOCATE
1587 /* If we cannot allocate large objects within re_match_2_internal,
1588 we make the fail stack and register vectors global.
1589 The fail stack, we grow to the maximum size when a regexp
1591 The register vectors, we adjust in size each time we
1592 compile a regexp, according to the number of registers it needs. */
1594 static fail_stack_type fail_stack;
1596 /* Size with which the following vectors are currently allocated.
1597 That is so we can make them bigger as needed,
1598 but never make them smaller. */
1599 static int regs_allocated_size;
1601 static const char ** regstart, ** regend;
1602 static const char ** old_regstart, ** old_regend;
1603 static const char **best_regstart, **best_regend;
1604 static register_info_type *reg_info;
1605 static const char **reg_dummy;
1606 static register_info_type *reg_info_dummy;
1608 /* Make the register vectors big enough for NUM_REGS registers,
1609 but don't make them smaller. */
1612 regex_grow_registers (num_regs)
1615 if (num_regs > regs_allocated_size)
1617 RETALLOC_IF (regstart, num_regs, const char *);
1618 RETALLOC_IF (regend, num_regs, const char *);
1619 RETALLOC_IF (old_regstart, num_regs, const char *);
1620 RETALLOC_IF (old_regend, num_regs, const char *);
1621 RETALLOC_IF (best_regstart, num_regs, const char *);
1622 RETALLOC_IF (best_regend, num_regs, const char *);
1623 RETALLOC_IF (reg_info, num_regs, register_info_type);
1624 RETALLOC_IF (reg_dummy, num_regs, const char *);
1625 RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
1627 regs_allocated_size = num_regs;
1631 #endif /* not MATCH_MAY_ALLOCATE */
1633 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1634 Returns one of error codes defined in `regex.h', or zero for success.
1636 Assumes the `allocated' (and perhaps `buffer') and `translate'
1637 fields are set in BUFP on entry.
1639 If it succeeds, results are put in BUFP (if it returns an error, the
1640 contents of BUFP are undefined):
1641 `buffer' is the compiled pattern;
1642 `syntax' is set to SYNTAX;
1643 `used' is set to the length of the compiled pattern;
1644 `fastmap_accurate' is zero;
1645 `re_nsub' is the number of subexpressions in PATTERN;
1646 `not_bol' and `not_eol' are zero;
1648 The `fastmap' and `newline_anchor' fields are neither
1649 examined nor set. */
1651 /* Return, freeing storage we allocated. */
1652 #define FREE_STACK_RETURN(value) \
1653 return (free (compile_stack.stack), value)
1655 static reg_errcode_t
1656 regex_compile (pattern, size, syntax, bufp)
1657 const char *pattern;
1659 reg_syntax_t syntax;
1660 struct re_pattern_buffer *bufp;
1662 /* We fetch characters from PATTERN here. Even though PATTERN is
1663 `char *' (i.e., signed), we declare these variables as unsigned, so
1664 they can be reliably used as array indices. */
1665 register unsigned char c, c1;
1667 /* A random temporary spot in PATTERN. */
1670 /* Points to the end of the buffer, where we should append. */
1671 register unsigned char *b;
1673 /* Keeps track of unclosed groups. */
1674 compile_stack_type compile_stack;
1676 /* Points to the current (ending) position in the pattern. */
1677 const char *p = pattern;
1678 const char *pend = pattern + size;
1680 /* How to translate the characters in the pattern. */
1681 RE_TRANSLATE_TYPE translate = bufp->translate;
1683 /* Address of the count-byte of the most recently inserted `exactn'
1684 command. This makes it possible to tell if a new exact-match
1685 character can be added to that command or if the character requires
1686 a new `exactn' command. */
1687 unsigned char *pending_exact = 0;
1689 /* Address of start of the most recently finished expression.
1690 This tells, e.g., postfix * where to find the start of its
1691 operand. Reset at the beginning of groups and alternatives. */
1692 unsigned char *laststart = 0;
1694 /* Address of beginning of regexp, or inside of last group. */
1695 unsigned char *begalt;
1697 /* Place in the uncompiled pattern (i.e., the {) to
1698 which to go back if the interval is invalid. */
1699 const char *beg_interval;
1701 /* Address of the place where a forward jump should go to the end of
1702 the containing expression. Each alternative of an `or' -- except the
1703 last -- ends with a forward jump of this sort. */
1704 unsigned char *fixup_alt_jump = 0;
1706 /* Counts open-groups as they are encountered. Remembered for the
1707 matching close-group on the compile stack, so the same register
1708 number is put in the stop_memory as the start_memory. */
1709 regnum_t regnum = 0;
1712 DEBUG_PRINT1 ("\nCompiling pattern: ");
1715 unsigned debug_count;
1717 for (debug_count = 0; debug_count < size; debug_count++)
1718 putchar (pattern[debug_count]);
1723 /* Initialize the compile stack. */
1724 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1725 if (compile_stack.stack == NULL)
1728 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1729 compile_stack.avail = 0;
1731 /* Initialize the pattern buffer. */
1732 bufp->syntax = syntax;
1733 bufp->fastmap_accurate = 0;
1734 bufp->not_bol = bufp->not_eol = 0;
1736 /* Set `used' to zero, so that if we return an error, the pattern
1737 printer (for debugging) will think there's no pattern. We reset it
1741 /* Always count groups, whether or not bufp->no_sub is set. */
1744 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1745 /* Initialize the syntax table. */
1746 init_syntax_once ();
1749 if (bufp->allocated == 0)
1752 { /* If zero allocated, but buffer is non-null, try to realloc
1753 enough space. This loses if buffer's address is bogus, but
1754 that is the user's responsibility. */
1755 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1758 { /* Caller did not allocate a buffer. Do it for them. */
1759 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1761 if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
1763 bufp->allocated = INIT_BUF_SIZE;
1766 begalt = b = bufp->buffer;
1768 /* Loop through the uncompiled pattern until we're at the end. */
1777 if ( /* If at start of pattern, it's an operator. */
1779 /* If context independent, it's an operator. */
1780 || syntax & RE_CONTEXT_INDEP_ANCHORS
1781 /* Otherwise, depends on what's come before. */
1782 || at_begline_loc_p (pattern, p, syntax))
1792 if ( /* If at end of pattern, it's an operator. */
1794 /* If context independent, it's an operator. */
1795 || syntax & RE_CONTEXT_INDEP_ANCHORS
1796 /* Otherwise, depends on what's next. */
1797 || at_endline_loc_p (p, pend, syntax))
1807 if ((syntax & RE_BK_PLUS_QM)
1808 || (syntax & RE_LIMITED_OPS))
1812 /* If there is no previous pattern... */
1815 if (syntax & RE_CONTEXT_INVALID_OPS)
1816 FREE_STACK_RETURN (REG_BADRPT);
1817 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1822 /* Are we optimizing this jump? */
1823 boolean keep_string_p = false;
1825 /* 1 means zero (many) matches is allowed. */
1826 char zero_times_ok = 0, many_times_ok = 0;
1828 /* If there is a sequence of repetition chars, collapse it
1829 down to just one (the right one). We can't combine
1830 interval operators with these because of, e.g., `a{2}*',
1831 which should only match an even number of `a's. */
1835 zero_times_ok |= c != '+';
1836 many_times_ok |= c != '?';
1844 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1847 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1849 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1852 if (!(c1 == '+' || c1 == '?'))
1867 /* If we get here, we found another repeat character. */
1870 /* Star, etc. applied to an empty pattern is equivalent
1871 to an empty pattern. */
1875 /* Now we know whether or not zero matches is allowed
1876 and also whether or not two or more matches is allowed. */
1878 { /* More than one repetition is allowed, so put in at the
1879 end a backward relative jump from `b' to before the next
1880 jump we're going to put in below (which jumps from
1881 laststart to after this jump).
1883 But if we are at the `*' in the exact sequence `.*\n',
1884 insert an unconditional jump backwards to the .,
1885 instead of the beginning of the loop. This way we only
1886 push a failure point once, instead of every time
1887 through the loop. */
1888 assert (p - 1 > pattern);
1890 /* Allocate the space for the jump. */
1891 GET_BUFFER_SPACE (3);
1893 /* We know we are not at the first character of the pattern,
1894 because laststart was nonzero. And we've already
1895 incremented `p', by the way, to be the character after
1896 the `*'. Do we have to do something analogous here
1897 for null bytes, because of RE_DOT_NOT_NULL? */
1898 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1900 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1901 && !(syntax & RE_DOT_NEWLINE))
1902 { /* We have .*\n. */
1903 STORE_JUMP (jump, b, laststart);
1904 keep_string_p = true;
1907 /* Anything else. */
1908 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1910 /* We've added more stuff to the buffer. */
1914 /* On failure, jump from laststart to b + 3, which will be the
1915 end of the buffer after this jump is inserted. */
1916 GET_BUFFER_SPACE (3);
1917 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1925 /* At least one repetition is required, so insert a
1926 `dummy_failure_jump' before the initial
1927 `on_failure_jump' instruction of the loop. This
1928 effects a skip over that instruction the first time
1929 we hit that loop. */
1930 GET_BUFFER_SPACE (3);
1931 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1946 boolean had_char_class = false;
1948 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
1950 /* Ensure that we have enough space to push a charset: the
1951 opcode, the length count, and the bitset; 34 bytes in all. */
1952 GET_BUFFER_SPACE (34);
1956 /* We test `*p == '^' twice, instead of using an if
1957 statement, so we only need one BUF_PUSH. */
1958 BUF_PUSH (*p == '^' ? charset_not : charset);
1962 /* Remember the first position in the bracket expression. */
1965 /* Push the number of bytes in the bitmap. */
1966 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1968 /* Clear the whole map. */
1969 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1971 /* charset_not matches newline according to a syntax bit. */
1972 if ((re_opcode_t) b[-2] == charset_not
1973 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1974 SET_LIST_BIT ('\n');
1976 /* Read in characters and ranges, setting map bits. */
1979 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
1983 /* \ might escape characters inside [...] and [^...]. */
1984 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1986 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1993 /* Could be the end of the bracket expression. If it's
1994 not (i.e., when the bracket expression is `[]' so
1995 far), the ']' character bit gets set way below. */
1996 if (c == ']' && p != p1 + 1)
1999 /* Look ahead to see if it's a range when the last thing
2000 was a character class. */
2001 if (had_char_class && c == '-' && *p != ']')
2002 FREE_STACK_RETURN (REG_ERANGE);
2004 /* Look ahead to see if it's a range when the last thing
2005 was a character: if this is a hyphen not at the
2006 beginning or the end of a list, then it's the range
2009 && !(p - 2 >= pattern && p[-2] == '[')
2010 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
2014 = compile_range (&p, pend, translate, syntax, b);
2015 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2018 else if (p[0] == '-' && p[1] != ']')
2019 { /* This handles ranges made up of characters only. */
2022 /* Move past the `-'. */
2025 ret = compile_range (&p, pend, translate, syntax, b);
2026 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
2029 /* See if we're at the beginning of a possible character
2032 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
2033 { /* Leave room for the null. */
2034 char str[CHAR_CLASS_MAX_LENGTH + 1];
2039 /* If pattern is `[[:'. */
2040 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2045 if (c == ':' || c == ']' || p == pend
2046 || c1 == CHAR_CLASS_MAX_LENGTH)
2052 /* If isn't a word bracketed by `[:' and:`]':
2053 undo the ending character, the letters, and leave
2054 the leading `:' and `[' (but set bits for them). */
2055 if (c == ':' && *p == ']')
2058 boolean is_alnum = STREQ (str, "alnum");
2059 boolean is_alpha = STREQ (str, "alpha");
2060 boolean is_blank = STREQ (str, "blank");
2061 boolean is_cntrl = STREQ (str, "cntrl");
2062 boolean is_digit = STREQ (str, "digit");
2063 boolean is_graph = STREQ (str, "graph");
2064 boolean is_lower = STREQ (str, "lower");
2065 boolean is_print = STREQ (str, "print");
2066 boolean is_punct = STREQ (str, "punct");
2067 boolean is_space = STREQ (str, "space");
2068 boolean is_upper = STREQ (str, "upper");
2069 boolean is_xdigit = STREQ (str, "xdigit");
2071 if (!IS_CHAR_CLASS (str))
2072 FREE_STACK_RETURN (REG_ECTYPE);
2074 /* Throw away the ] at the end of the character
2078 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2080 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
2082 /* This was split into 3 if's to
2083 avoid an arbitrary limit in some compiler. */
2084 if ( (is_alnum && ISALNUM (ch))
2085 || (is_alpha && ISALPHA (ch))
2086 || (is_blank && ISBLANK (ch))
2087 || (is_cntrl && ISCNTRL (ch)))
2089 if ( (is_digit && ISDIGIT (ch))
2090 || (is_graph && ISGRAPH (ch))
2091 || (is_lower && ISLOWER (ch))
2092 || (is_print && ISPRINT (ch)))
2094 if ( (is_punct && ISPUNCT (ch))
2095 || (is_space && ISSPACE (ch))
2096 || (is_upper && ISUPPER (ch))
2097 || (is_xdigit && ISXDIGIT (ch)))
2100 had_char_class = true;
2109 had_char_class = false;
2114 had_char_class = false;
2119 /* Discard any (non)matching list bytes that are all 0 at the
2120 end of the map. Decrease the map-length byte too. */
2121 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
2129 if (syntax & RE_NO_BK_PARENS)
2136 if (syntax & RE_NO_BK_PARENS)
2143 if (syntax & RE_NEWLINE_ALT)
2150 if (syntax & RE_NO_BK_VBAR)
2157 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
2158 goto handle_interval;
2164 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2166 /* Do not translate the character after the \, so that we can
2167 distinguish, e.g., \B from \b, even if we normally would
2168 translate, e.g., B to b. */
2174 if (syntax & RE_NO_BK_PARENS)
2175 goto normal_backslash;
2181 if (COMPILE_STACK_FULL)
2183 RETALLOC (compile_stack.stack, compile_stack.size << 1,
2184 compile_stack_elt_t);
2185 if (compile_stack.stack == NULL) return REG_ESPACE;
2187 compile_stack.size <<= 1;
2190 /* These are the values to restore when we hit end of this
2191 group. They are all relative offsets, so that if the
2192 whole pattern moves because of realloc, they will still
2194 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2195 COMPILE_STACK_TOP.fixup_alt_jump
2196 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2197 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2198 COMPILE_STACK_TOP.regnum = regnum;
2200 /* We will eventually replace the 0 with the number of
2201 groups inner to this one. But do not push a
2202 start_memory for groups beyond the last one we can
2203 represent in the compiled pattern. */
2204 if (regnum <= MAX_REGNUM)
2206 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2207 BUF_PUSH_3 (start_memory, regnum, 0);
2210 compile_stack.avail++;
2215 /* If we've reached MAX_REGNUM groups, then this open
2216 won't actually generate any code, so we'll have to
2217 clear pending_exact explicitly. */
2223 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
2225 if (COMPILE_STACK_EMPTY)
2226 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2227 goto normal_backslash;
2229 FREE_STACK_RETURN (REG_ERPAREN);
2233 { /* Push a dummy failure point at the end of the
2234 alternative for a possible future
2235 `pop_failure_jump' to pop. See comments at
2236 `push_dummy_failure' in `re_match_2'. */
2237 BUF_PUSH (push_dummy_failure);
2239 /* We allocated space for this jump when we assigned
2240 to `fixup_alt_jump', in the `handle_alt' case below. */
2241 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2244 /* See similar code for backslashed left paren above. */
2245 if (COMPILE_STACK_EMPTY)
2246 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2249 FREE_STACK_RETURN (REG_ERPAREN);
2251 /* Since we just checked for an empty stack above, this
2252 ``can't happen''. */
2253 assert (compile_stack.avail != 0);
2255 /* We don't just want to restore into `regnum', because
2256 later groups should continue to be numbered higher,
2257 as in `(ab)c(de)' -- the second group is #2. */
2258 regnum_t this_group_regnum;
2260 compile_stack.avail--;
2261 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2263 = COMPILE_STACK_TOP.fixup_alt_jump
2264 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
2266 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2267 this_group_regnum = COMPILE_STACK_TOP.regnum;
2268 /* If we've reached MAX_REGNUM groups, then this open
2269 won't actually generate any code, so we'll have to
2270 clear pending_exact explicitly. */
2273 /* We're at the end of the group, so now we know how many
2274 groups were inside this one. */
2275 if (this_group_regnum <= MAX_REGNUM)
2277 unsigned char *inner_group_loc
2278 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2280 *inner_group_loc = regnum - this_group_regnum;
2281 BUF_PUSH_3 (stop_memory, this_group_regnum,
2282 regnum - this_group_regnum);
2288 case '|': /* `\|'. */
2289 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
2290 goto normal_backslash;
2292 if (syntax & RE_LIMITED_OPS)
2295 /* Insert before the previous alternative a jump which
2296 jumps to this alternative if the former fails. */
2297 GET_BUFFER_SPACE (3);
2298 INSERT_JUMP (on_failure_jump, begalt, b + 6);
2302 /* The alternative before this one has a jump after it
2303 which gets executed if it gets matched. Adjust that
2304 jump so it will jump to this alternative's analogous
2305 jump (put in below, which in turn will jump to the next
2306 (if any) alternative's such jump, etc.). The last such
2307 jump jumps to the correct final destination. A picture:
2313 If we are at `b', then fixup_alt_jump right now points to a
2314 three-byte space after `a'. We'll put in the jump, set
2315 fixup_alt_jump to right after `b', and leave behind three
2316 bytes which we'll fill in when we get to after `c'. */
2319 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2321 /* Mark and leave space for a jump after this alternative,
2322 to be filled in later either by next alternative or
2323 when know we're at the end of a series of alternatives. */
2325 GET_BUFFER_SPACE (3);
2334 /* If \{ is a literal. */
2335 if (!(syntax & RE_INTERVALS)
2336 /* If we're at `\{' and it's not the open-interval
2338 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2339 || (p - 2 == pattern && p == pend))
2340 goto normal_backslash;
2344 /* If got here, then the syntax allows intervals. */
2346 /* At least (most) this many matches must be made. */
2347 int lower_bound = -1, upper_bound = -1;
2349 beg_interval = p - 1;
2353 if (syntax & RE_NO_BK_BRACES)
2354 goto unfetch_interval;
2356 FREE_STACK_RETURN (REG_EBRACE);
2359 GET_UNSIGNED_NUMBER (lower_bound);
2363 GET_UNSIGNED_NUMBER (upper_bound);
2364 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
2367 /* Interval such as `{1}' => match exactly once. */
2368 upper_bound = lower_bound;
2370 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
2371 || lower_bound > upper_bound)
2373 if (syntax & RE_NO_BK_BRACES)
2374 goto unfetch_interval;
2376 FREE_STACK_RETURN (REG_BADBR);
2379 if (!(syntax & RE_NO_BK_BRACES))
2381 if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
2388 if (syntax & RE_NO_BK_BRACES)
2389 goto unfetch_interval;
2391 FREE_STACK_RETURN (REG_BADBR);
2394 /* We just parsed a valid interval. */
2396 /* If it's invalid to have no preceding re. */
2399 if (syntax & RE_CONTEXT_INVALID_OPS)
2400 FREE_STACK_RETURN (REG_BADRPT);
2401 else if (syntax & RE_CONTEXT_INDEP_OPS)
2404 goto unfetch_interval;
2407 /* If the upper bound is zero, don't want to succeed at
2408 all; jump from `laststart' to `b + 3', which will be
2409 the end of the buffer after we insert the jump. */
2410 if (upper_bound == 0)
2412 GET_BUFFER_SPACE (3);
2413 INSERT_JUMP (jump, laststart, b + 3);
2417 /* Otherwise, we have a nontrivial interval. When
2418 we're all done, the pattern will look like:
2419 set_number_at <jump count> <upper bound>
2420 set_number_at <succeed_n count> <lower bound>
2421 succeed_n <after jump addr> <succeed_n count>
2423 jump_n <succeed_n addr> <jump count>
2424 (The upper bound and `jump_n' are omitted if
2425 `upper_bound' is 1, though.) */
2427 { /* If the upper bound is > 1, we need to insert
2428 more at the end of the loop. */
2429 unsigned nbytes = 10 + (upper_bound > 1) * 10;
2431 GET_BUFFER_SPACE (nbytes);
2433 /* Initialize lower bound of the `succeed_n', even
2434 though it will be set during matching by its
2435 attendant `set_number_at' (inserted next),
2436 because `re_compile_fastmap' needs to know.
2437 Jump to the `jump_n' we might insert below. */
2438 INSERT_JUMP2 (succeed_n, laststart,
2439 b + 5 + (upper_bound > 1) * 5,
2443 /* Code to initialize the lower bound. Insert
2444 before the `succeed_n'. The `5' is the last two
2445 bytes of this `set_number_at', plus 3 bytes of
2446 the following `succeed_n'. */
2447 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2450 if (upper_bound > 1)
2451 { /* More than one repetition is allowed, so
2452 append a backward jump to the `succeed_n'
2453 that starts this interval.
2455 When we've reached this during matching,
2456 we'll have matched the interval once, so
2457 jump back only `upper_bound - 1' times. */
2458 STORE_JUMP2 (jump_n, b, laststart + 5,
2462 /* The location we want to set is the second
2463 parameter of the `jump_n'; that is `b-2' as
2464 an absolute address. `laststart' will be
2465 the `set_number_at' we're about to insert;
2466 `laststart+3' the number to set, the source
2467 for the relative address. But we are
2468 inserting into the middle of the pattern --
2469 so everything is getting moved up by 5.
2470 Conclusion: (b - 2) - (laststart + 3) + 5,
2471 i.e., b - laststart.
2473 We insert this at the beginning of the loop
2474 so that if we fail during matching, we'll
2475 reinitialize the bounds. */
2476 insert_op2 (set_number_at, laststart, b - laststart,
2477 upper_bound - 1, b);
2482 beg_interval = NULL;
2487 /* If an invalid interval, match the characters as literals. */
2488 assert (beg_interval);
2490 beg_interval = NULL;
2492 /* normal_char and normal_backslash need `c'. */
2495 if (!(syntax & RE_NO_BK_BRACES))
2497 if (p > pattern && p[-1] == '\\')
2498 goto normal_backslash;
2503 /* There is no way to specify the before_dot and after_dot
2504 operators. rms says this is ok. --karl */
2512 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2518 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2525 BUF_PUSH (wordchar);
2531 BUF_PUSH (notwordchar);
2544 BUF_PUSH (wordbound);
2548 BUF_PUSH (notwordbound);
2559 case '1': case '2': case '3': case '4': case '5':
2560 case '6': case '7': case '8': case '9':
2561 if (syntax & RE_NO_BK_REFS)
2567 FREE_STACK_RETURN (REG_ESUBREG);
2569 /* Can't back reference to a subexpression if inside of it. */
2570 if (group_in_compile_stack (compile_stack, c1))
2574 BUF_PUSH_2 (duplicate, c1);
2580 if (syntax & RE_BK_PLUS_QM)
2583 goto normal_backslash;
2587 /* You might think it would be useful for \ to mean
2588 not to translate; but if we don't translate it
2589 it will never match anything. */
2597 /* Expects the character in `c'. */
2599 /* If no exactn currently being built. */
2602 /* If last exactn not at current position. */
2603 || pending_exact + *pending_exact + 1 != b
2605 /* We have only one byte following the exactn for the count. */
2606 || *pending_exact == (1 << BYTEWIDTH) - 1
2608 /* If followed by a repetition operator. */
2609 || *p == '*' || *p == '^'
2610 || ((syntax & RE_BK_PLUS_QM)
2611 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2612 : (*p == '+' || *p == '?'))
2613 || ((syntax & RE_INTERVALS)
2614 && ((syntax & RE_NO_BK_BRACES)
2616 : (p[0] == '\\' && p[1] == '{'))))
2618 /* Start building a new exactn. */
2622 BUF_PUSH_2 (exactn, 0);
2623 pending_exact = b - 1;
2630 } /* while p != pend */
2633 /* Through the pattern now. */
2636 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2638 if (!COMPILE_STACK_EMPTY)
2639 FREE_STACK_RETURN (REG_EPAREN);
2641 /* If we don't want backtracking, force success
2642 the first time we reach the end of the compiled pattern. */
2643 if (syntax & RE_NO_POSIX_BACKTRACKING)
2646 free (compile_stack.stack);
2648 /* We have succeeded; set the length of the buffer. */
2649 bufp->used = b - bufp->buffer;
2654 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2655 print_compiled_pattern (bufp);
2659 #ifndef MATCH_MAY_ALLOCATE
2660 /* Initialize the failure stack to the largest possible stack. This
2661 isn't necessary unless we're trying to avoid calling alloca in
2662 the search and match routines. */
2664 int num_regs = bufp->re_nsub + 1;
2666 /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2667 is strictly greater than re_max_failures, the largest possible stack
2668 is 2 * re_max_failures failure points. */
2669 if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
2671 fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2674 if (! fail_stack.stack)
2676 = (fail_stack_elt_t *) xmalloc (fail_stack.size
2677 * sizeof (fail_stack_elt_t));
2680 = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
2682 * sizeof (fail_stack_elt_t)));
2683 #else /* not emacs */
2684 if (! fail_stack.stack)
2686 = (fail_stack_elt_t *) malloc (fail_stack.size
2687 * sizeof (fail_stack_elt_t));
2690 = (fail_stack_elt_t *) realloc (fail_stack.stack,
2692 * sizeof (fail_stack_elt_t)));
2693 #endif /* not emacs */
2696 regex_grow_registers (num_regs);
2698 #endif /* not MATCH_MAY_ALLOCATE */
2701 } /* regex_compile */
2703 /* Subroutines for `regex_compile'. */
2705 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2708 store_op1 (op, loc, arg)
2713 *loc = (unsigned char) op;
2714 STORE_NUMBER (loc + 1, arg);
2718 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2721 store_op2 (op, loc, arg1, arg2)
2726 *loc = (unsigned char) op;
2727 STORE_NUMBER (loc + 1, arg1);
2728 STORE_NUMBER (loc + 3, arg2);
2732 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2733 for OP followed by two-byte integer parameter ARG. */
2736 insert_op1 (op, loc, arg, end)
2742 register unsigned char *pfrom = end;
2743 register unsigned char *pto = end + 3;
2745 while (pfrom != loc)
2748 store_op1 (op, loc, arg);
2752 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2755 insert_op2 (op, loc, arg1, arg2, end)
2761 register unsigned char *pfrom = end;
2762 register unsigned char *pto = end + 5;
2764 while (pfrom != loc)
2767 store_op2 (op, loc, arg1, arg2);
2771 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2772 after an alternative or a begin-subexpression. We assume there is at
2773 least one character before the ^. */
2776 at_begline_loc_p (pattern, p, syntax)
2777 const char *pattern, *p;
2778 reg_syntax_t syntax;
2780 const char *prev = p - 2;
2781 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2784 /* After a subexpression? */
2785 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2786 /* After an alternative? */
2787 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2791 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2792 at least one character after the $, i.e., `P < PEND'. */
2795 at_endline_loc_p (p, pend, syntax)
2796 const char *p, *pend;
2799 const char *next = p;
2800 boolean next_backslash = *next == '\\';
2801 const char *next_next = p + 1 < pend ? p + 1 : 0;
2804 /* Before a subexpression? */
2805 (syntax & RE_NO_BK_PARENS ? *next == ')'
2806 : next_backslash && next_next && *next_next == ')')
2807 /* Before an alternative? */
2808 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2809 : next_backslash && next_next && *next_next == '|');
2813 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2814 false if it's not. */
2817 group_in_compile_stack (compile_stack, regnum)
2818 compile_stack_type compile_stack;
2823 for (this_element = compile_stack.avail - 1;
2826 if (compile_stack.stack[this_element].regnum == regnum)
2833 /* Read the ending character of a range (in a bracket expression) from the
2834 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2835 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2836 Then we set the translation of all bits between the starting and
2837 ending characters (inclusive) in the compiled pattern B.
2839 Return an error code.
2841 We use these short variable names so we can use the same macros as
2842 `regex_compile' itself. */
2844 static reg_errcode_t
2845 compile_range (p_ptr, pend, translate, syntax, b)
2846 const char **p_ptr, *pend;
2847 RE_TRANSLATE_TYPE translate;
2848 reg_syntax_t syntax;
2853 const char *p = *p_ptr;
2854 int range_start, range_end;
2859 /* Even though the pattern is a signed `char *', we need to fetch
2860 with unsigned char *'s; if the high bit of the pattern character
2861 is set, the range endpoints will be negative if we fetch using a
2864 We also want to fetch the endpoints without translating them; the
2865 appropriate translation is done in the bit-setting loop below. */
2866 /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *. */
2867 range_start = ((const unsigned char *) p)[-2];
2868 range_end = ((const unsigned char *) p)[0];
2870 /* Have to increment the pointer into the pattern string, so the
2871 caller isn't still at the ending character. */
2874 /* If the start is after the end, the range is empty. */
2875 if (range_start > range_end)
2876 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2878 /* Here we see why `this_char' has to be larger than an `unsigned
2879 char' -- the range is inclusive, so if `range_end' == 0xff
2880 (assuming 8-bit characters), we would otherwise go into an infinite
2881 loop, since all characters <= 0xff. */
2882 for (this_char = range_start; this_char <= range_end; this_char++)
2884 SET_LIST_BIT (TRANSLATE (this_char));
2890 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2891 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2892 characters can start a string that matches the pattern. This fastmap
2893 is used by re_search to skip quickly over impossible starting points.
2895 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2896 area as BUFP->fastmap.
2898 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2901 Returns 0 if we succeed, -2 if an internal error. */
2904 re_compile_fastmap (bufp)
2905 struct re_pattern_buffer *bufp;
2908 #ifdef MATCH_MAY_ALLOCATE
2909 fail_stack_type fail_stack;
2911 #ifndef REGEX_MALLOC
2914 /* We don't push any register information onto the failure stack. */
2915 unsigned num_regs = 0;
2917 register char *fastmap = bufp->fastmap;
2918 unsigned char *pattern = bufp->buffer;
2919 unsigned long size = bufp->used;
2920 unsigned char *p = pattern;
2921 register unsigned char *pend = pattern + size;
2923 /* This holds the pointer to the failure stack, when
2924 it is allocated relocatably. */
2925 fail_stack_elt_t *failure_stack_ptr;
2927 /* Assume that each path through the pattern can be null until
2928 proven otherwise. We set this false at the bottom of switch
2929 statement, to which we get only if a particular path doesn't
2930 match the empty string. */
2931 boolean path_can_be_null = true;
2933 /* We aren't doing a `succeed_n' to begin with. */
2934 boolean succeed_n_p = false;
2936 assert (fastmap != NULL && p != NULL);
2939 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2940 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2941 bufp->can_be_null = 0;
2945 if (p == pend || *p == succeed)
2947 /* We have reached the (effective) end of pattern. */
2948 if (!FAIL_STACK_EMPTY ())
2950 bufp->can_be_null |= path_can_be_null;
2952 /* Reset for next path. */
2953 path_can_be_null = true;
2955 p = fail_stack.stack[--fail_stack.avail].pointer;
2963 /* We should never be about to go beyond the end of the pattern. */
2966 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
2969 /* I guess the idea here is to simply not bother with a fastmap
2970 if a backreference is used, since it's too hard to figure out
2971 the fastmap for the corresponding group. Setting
2972 `can_be_null' stops `re_search_2' from using the fastmap, so
2973 that is all we do. */
2975 bufp->can_be_null = 1;
2979 /* Following are the cases which match a character. These end
2988 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2989 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2995 /* Chars beyond end of map must be allowed. */
2996 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2999 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
3000 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
3006 for (j = 0; j < (1 << BYTEWIDTH); j++)
3007 if (SYNTAX (j) == Sword)
3013 for (j = 0; j < (1 << BYTEWIDTH); j++)
3014 if (SYNTAX (j) != Sword)
3021 int fastmap_newline = fastmap['\n'];
3023 /* `.' matches anything ... */
3024 for (j = 0; j < (1 << BYTEWIDTH); j++)
3027 /* ... except perhaps newline. */
3028 if (!(bufp->syntax & RE_DOT_NEWLINE))
3029 fastmap['\n'] = fastmap_newline;
3031 /* Return if we have already set `can_be_null'; if we have,
3032 then the fastmap is irrelevant. Something's wrong here. */
3033 else if (bufp->can_be_null)
3036 /* Otherwise, have to check alternative paths. */
3043 for (j = 0; j < (1 << BYTEWIDTH); j++)
3044 if (SYNTAX (j) == (enum syntaxcode) k)
3051 for (j = 0; j < (1 << BYTEWIDTH); j++)
3052 if (SYNTAX (j) != (enum syntaxcode) k)
3057 /* All cases after this match the empty string. These end with
3077 case push_dummy_failure:
3082 case pop_failure_jump:
3083 case maybe_pop_jump:
3086 case dummy_failure_jump:
3087 EXTRACT_NUMBER_AND_INCR (j, p);
3092 /* Jump backward implies we just went through the body of a
3093 loop and matched nothing. Opcode jumped to should be
3094 `on_failure_jump' or `succeed_n'. Just treat it like an
3095 ordinary jump. For a * loop, it has pushed its failure
3096 point already; if so, discard that as redundant. */
3097 if ((re_opcode_t) *p != on_failure_jump
3098 && (re_opcode_t) *p != succeed_n)
3102 EXTRACT_NUMBER_AND_INCR (j, p);
3105 /* If what's on the stack is where we are now, pop it. */
3106 if (!FAIL_STACK_EMPTY ()
3107 && fail_stack.stack[fail_stack.avail - 1].pointer == p)
3113 case on_failure_jump:
3114 case on_failure_keep_string_jump:
3115 handle_on_failure_jump:
3116 EXTRACT_NUMBER_AND_INCR (j, p);
3118 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
3119 end of the pattern. We don't want to push such a point,
3120 since when we restore it above, entering the switch will
3121 increment `p' past the end of the pattern. We don't need
3122 to push such a point since we obviously won't find any more
3123 fastmap entries beyond `pend'. Such a pattern can match
3124 the null string, though. */
3127 if (!PUSH_PATTERN_OP (p + j, fail_stack))
3129 RESET_FAIL_STACK ();
3134 bufp->can_be_null = 1;
3138 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
3139 succeed_n_p = false;
3146 /* Get to the number of times to succeed. */
3149 /* Increment p past the n for when k != 0. */
3150 EXTRACT_NUMBER_AND_INCR (k, p);
3154 succeed_n_p = true; /* Spaghetti code alert. */
3155 goto handle_on_failure_jump;
3172 abort (); /* We have listed all the cases. */
3175 /* Getting here means we have found the possible starting
3176 characters for one path of the pattern -- and that the empty
3177 string does not match. We need not follow this path further.
3178 Instead, look at the next alternative (remembered on the
3179 stack), or quit if no more. The test at the top of the loop
3180 does these things. */
3181 path_can_be_null = false;
3185 /* Set `can_be_null' for the last path (also the first path, if the
3186 pattern is empty). */
3187 bufp->can_be_null |= path_can_be_null;
3190 RESET_FAIL_STACK ();
3192 } /* re_compile_fastmap */
3194 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
3195 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
3196 this memory for recording register information. STARTS and ENDS
3197 must be allocated using the malloc library routine, and must each
3198 be at least NUM_REGS * sizeof (regoff_t) bytes long.
3200 If NUM_REGS == 0, then subsequent matches should allocate their own
3203 Unless this function is called, the first search or match using
3204 PATTERN_BUFFER will allocate its own register data, without
3205 freeing the old data. */
3208 re_set_registers (bufp, regs, num_regs, starts, ends)
3209 struct re_pattern_buffer *bufp;
3210 struct re_registers *regs;
3212 regoff_t *starts, *ends;
3216 bufp->regs_allocated = REGS_REALLOCATE;
3217 regs->num_regs = num_regs;
3218 regs->start = starts;
3223 bufp->regs_allocated = REGS_UNALLOCATED;
3225 regs->start = regs->end = (regoff_t *) 0;
3229 /* Searching routines. */
3231 /* Like re_search_2, below, but only one string is specified, and
3232 doesn't let you say where to stop matching. */
3235 re_search (bufp, string, size, startpos, range, regs)
3236 struct re_pattern_buffer *bufp;
3238 int size, startpos, range;
3239 struct re_registers *regs;
3241 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3246 /* Using the compiled pattern in BUFP->buffer, first tries to match the
3247 virtual concatenation of STRING1 and STRING2, starting first at index
3248 STARTPOS, then at STARTPOS + 1, and so on.
3250 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3252 RANGE is how far to scan while trying to match. RANGE = 0 means try
3253 only at STARTPOS; in general, the last start tried is STARTPOS +
3256 In REGS, return the indices of the virtual concatenation of STRING1
3257 and STRING2 that matched the entire BUFP->buffer and its contained
3260 Do not consider matching one past the index STOP in the virtual
3261 concatenation of STRING1 and STRING2.
3263 We return either the position in the strings at which the match was
3264 found, -1 if no match, or -2 if error (such as failure
3268 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3269 struct re_pattern_buffer *bufp;
3270 const char *string1, *string2;
3274 struct re_registers *regs;
3278 register char *fastmap = bufp->fastmap;
3279 register RE_TRANSLATE_TYPE translate = bufp->translate;
3280 int total_size = size1 + size2;
3281 int endpos = startpos + range;
3283 /* Check for out-of-range STARTPOS. */
3284 if (startpos < 0 || startpos > total_size)
3287 /* Fix up RANGE if it might eventually take us outside
3288 the virtual concatenation of STRING1 and STRING2.
3289 Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE. */
3291 range = 0 - startpos;
3292 else if (endpos > total_size)
3293 range = total_size - startpos;
3295 /* If the search isn't to be a backwards one, don't waste time in a
3296 search for a pattern that must be anchored. */
3297 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3306 /* In a forward search for something that starts with \=.
3307 don't keep searching past point. */
3308 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0)
3310 range = PT - startpos;
3316 /* Update the fastmap now if not correct already. */
3317 if (fastmap && !bufp->fastmap_accurate)
3318 if (re_compile_fastmap (bufp) == -2)
3321 /* Loop through the string, looking for a place to start matching. */
3324 /* If a fastmap is supplied, skip quickly over characters that
3325 cannot be the start of a match. If the pattern can match the
3326 null string, however, we don't need to skip characters; we want
3327 the first null string. */
3328 if (fastmap && startpos < total_size && !bufp->can_be_null)
3330 if (range > 0) /* Searching forwards. */
3332 register const char *d;
3333 register int lim = 0;
3336 if (startpos < size1 && startpos + range >= size1)
3337 lim = range - (size1 - startpos);
3339 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3341 /* Written out as an if-else to avoid testing `translate'
3345 && !fastmap[(unsigned char)
3346 translate[(unsigned char) *d++]])
3349 while (range > lim && !fastmap[(unsigned char) *d++])
3352 startpos += irange - range;
3354 else /* Searching backwards. */
3356 register char c = (size1 == 0 || startpos >= size1
3357 ? string2[startpos - size1]
3358 : string1[startpos]);
3360 if (!fastmap[(unsigned char) TRANSLATE (c)])
3365 /* If can't match the null string, and that's all we have left, fail. */
3366 if (range >= 0 && startpos == total_size && fastmap
3367 && !bufp->can_be_null)
3370 val = re_match_2_internal (bufp, string1, size1, string2, size2,
3371 startpos, regs, stop);
3372 #ifndef REGEX_MALLOC
3401 /* Declarations and macros for re_match_2. */
3403 static int bcmp_translate ();
3404 static boolean alt_match_null_string_p (),
3405 common_op_match_null_string_p (),
3406 group_match_null_string_p ();
3408 /* This converts PTR, a pointer into one of the search strings `string1'
3409 and `string2' into an offset from the beginning of that string. */
3410 #define POINTER_TO_OFFSET(ptr) \
3411 (FIRST_STRING_P (ptr) \
3412 ? ((regoff_t) ((ptr) - string1)) \
3413 : ((regoff_t) ((ptr) - string2 + size1)))
3415 /* Macros for dealing with the split strings in re_match_2. */
3417 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3419 /* Call before fetching a character with *d. This switches over to
3420 string2 if necessary. */
3421 #define PREFETCH() \
3424 /* End of string2 => fail. */ \
3425 if (dend == end_match_2) \
3427 /* End of string1 => advance to string2. */ \
3429 dend = end_match_2; \
3433 /* Test if at very beginning or at very end of the virtual concatenation
3434 of `string1' and `string2'. If only one string, it's `string2'. */
3435 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3436 #define AT_STRINGS_END(d) ((d) == end2)
3439 /* Test if D points to a character which is word-constituent. We have
3440 two special cases to check for: if past the end of string1, look at
3441 the first character in string2; and if before the beginning of
3442 string2, look at the last character in string1. */
3443 #define WORDCHAR_P(d) \
3444 (SYNTAX ((d) == end1 ? *string2 \
3445 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3448 /* Disabled due to a compiler bug -- see comment at case wordbound */
3450 /* Test if the character before D and the one at D differ with respect
3451 to being word-constituent. */
3452 #define AT_WORD_BOUNDARY(d) \
3453 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3454 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3457 /* Free everything we malloc. */
3458 #ifdef MATCH_MAY_ALLOCATE
3459 #define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
3460 #define FREE_VARIABLES() \
3462 REGEX_FREE_STACK (fail_stack.stack); \
3463 FREE_VAR (regstart); \
3464 FREE_VAR (regend); \
3465 FREE_VAR (old_regstart); \
3466 FREE_VAR (old_regend); \
3467 FREE_VAR (best_regstart); \
3468 FREE_VAR (best_regend); \
3469 FREE_VAR (reg_info); \
3470 FREE_VAR (reg_dummy); \
3471 FREE_VAR (reg_info_dummy); \
3474 #define FREE_VARIABLES() ((void)0) /* Do nothing! But inhibit gcc warning. */
3475 #endif /* not MATCH_MAY_ALLOCATE */
3477 /* These values must meet several constraints. They must not be valid
3478 register values; since we have a limit of 255 registers (because
3479 we use only one byte in the pattern for the register number), we can
3480 use numbers larger than 255. They must differ by 1, because of
3481 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3482 be larger than the value for the highest register, so we do not try
3483 to actually save any registers when none are active. */
3484 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3485 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3487 /* Matching routines. */
3489 #ifndef emacs /* Emacs never uses this. */
3490 /* re_match is like re_match_2 except it takes only a single string. */
3493 re_match (bufp, string, size, pos, regs)
3494 struct re_pattern_buffer *bufp;
3497 struct re_registers *regs;
3499 int result = re_match_2_internal (bufp, NULL, 0, string, size,
3504 #endif /* not emacs */
3507 /* re_match_2 matches the compiled pattern in BUFP against the
3508 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3509 and SIZE2, respectively). We start matching at POS, and stop
3512 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3513 store offsets for the substring each group matched in REGS. See the
3514 documentation for exactly how many groups we fill.
3516 We return -1 if no match, -2 if an internal error (such as the
3517 failure stack overflowing). Otherwise, we return the length of the
3518 matched substring. */
3521 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3522 struct re_pattern_buffer *bufp;
3523 const char *string1, *string2;
3526 struct re_registers *regs;
3529 int result = re_match_2_internal (bufp, string1, size1, string2, size2,
3535 /* This is a separate function so that we can force an alloca cleanup
3538 re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
3539 struct re_pattern_buffer *bufp;
3540 const char *string1, *string2;
3543 struct re_registers *regs;
3546 /* General temporaries. */
3550 /* Just past the end of the corresponding string. */
3551 const char *end1, *end2;
3553 /* Pointers into string1 and string2, just past the last characters in
3554 each to consider matching. */
3555 const char *end_match_1, *end_match_2;
3557 /* Where we are in the data, and the end of the current string. */
3558 const char *d, *dend;
3560 /* Where we are in the pattern, and the end of the pattern. */
3561 unsigned char *p = bufp->buffer;
3562 register unsigned char *pend = p + bufp->used;
3564 /* Mark the opcode just after a start_memory, so we can test for an
3565 empty subpattern when we get to the stop_memory. */
3566 unsigned char *just_past_start_mem = 0;
3568 /* We use this to map every character in the string. */
3569 RE_TRANSLATE_TYPE translate = bufp->translate;
3571 /* Failure point stack. Each place that can handle a failure further
3572 down the line pushes a failure point on this stack. It consists of
3573 restart, regend, and reg_info for all registers corresponding to
3574 the subexpressions we're currently inside, plus the number of such
3575 registers, and, finally, two char *'s. The first char * is where
3576 to resume scanning the pattern; the second one is where to resume
3577 scanning the strings. If the latter is zero, the failure point is
3578 a ``dummy''; if a failure happens and the failure point is a dummy,
3579 it gets discarded and the next next one is tried. */
3580 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3581 fail_stack_type fail_stack;
3584 static unsigned failure_id = 0;
3585 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3588 /* This holds the pointer to the failure stack, when
3589 it is allocated relocatably. */
3590 fail_stack_elt_t *failure_stack_ptr;
3592 /* We fill all the registers internally, independent of what we
3593 return, for use in backreferences. The number here includes
3594 an element for register zero. */
3595 unsigned num_regs = bufp->re_nsub + 1;
3597 /* The currently active registers. */
3598 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3599 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3601 /* Information on the contents of registers. These are pointers into
3602 the input strings; they record just what was matched (on this
3603 attempt) by a subexpression part of the pattern, that is, the
3604 regnum-th regstart pointer points to where in the pattern we began
3605 matching and the regnum-th regend points to right after where we
3606 stopped matching the regnum-th subexpression. (The zeroth register
3607 keeps track of what the whole pattern matches.) */
3608 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3609 const char **regstart, **regend;
3612 /* If a group that's operated upon by a repetition operator fails to
3613 match anything, then the register for its start will need to be
3614 restored because it will have been set to wherever in the string we
3615 are when we last see its open-group operator. Similarly for a
3617 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3618 const char **old_regstart, **old_regend;
3621 /* The is_active field of reg_info helps us keep track of which (possibly
3622 nested) subexpressions we are currently in. The matched_something
3623 field of reg_info[reg_num] helps us tell whether or not we have
3624 matched any of the pattern so far this time through the reg_num-th
3625 subexpression. These two fields get reset each time through any
3626 loop their register is in. */
3627 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3628 register_info_type *reg_info;
3631 /* The following record the register info as found in the above
3632 variables when we find a match better than any we've seen before.
3633 This happens as we backtrack through the failure points, which in
3634 turn happens only if we have not yet matched the entire string. */
3635 unsigned best_regs_set = false;
3636 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3637 const char **best_regstart, **best_regend;
3640 /* Logically, this is `best_regend[0]'. But we don't want to have to
3641 allocate space for that if we're not allocating space for anything
3642 else (see below). Also, we never need info about register 0 for
3643 any of the other register vectors, and it seems rather a kludge to
3644 treat `best_regend' differently than the rest. So we keep track of
3645 the end of the best match so far in a separate variable. We
3646 initialize this to NULL so that when we backtrack the first time
3647 and need to test it, it's not garbage. */
3648 const char *match_end = NULL;
3650 /* This helps SET_REGS_MATCHED avoid doing redundant work. */
3651 int set_regs_matched_done = 0;
3653 /* Used when we pop values we don't care about. */
3654 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3655 const char **reg_dummy;
3656 register_info_type *reg_info_dummy;
3660 /* Counts the total number of registers pushed. */
3661 unsigned num_regs_pushed = 0;
3664 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3668 #ifdef MATCH_MAY_ALLOCATE
3669 /* Do not bother to initialize all the register variables if there are
3670 no groups in the pattern, as it takes a fair amount of time. If
3671 there are groups, we include space for register 0 (the whole
3672 pattern), even though we never use it, since it simplifies the
3673 array indexing. We should fix this. */
3676 regstart = REGEX_TALLOC (num_regs, const char *);
3677 regend = REGEX_TALLOC (num_regs, const char *);
3678 old_regstart = REGEX_TALLOC (num_regs, const char *);
3679 old_regend = REGEX_TALLOC (num_regs, const char *);
3680 best_regstart = REGEX_TALLOC (num_regs, const char *);
3681 best_regend = REGEX_TALLOC (num_regs, const char *);
3682 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3683 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3684 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3686 if (!(regstart && regend && old_regstart && old_regend && reg_info
3687 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3695 /* We must initialize all our variables to NULL, so that
3696 `FREE_VARIABLES' doesn't try to free them. */
3697 regstart = regend = old_regstart = old_regend = best_regstart
3698 = best_regend = reg_dummy = NULL;
3699 reg_info = reg_info_dummy = (register_info_type *) NULL;
3701 #endif /* MATCH_MAY_ALLOCATE */
3703 /* The starting position is bogus. */
3704 if (pos < 0 || pos > size1 + size2)
3710 /* Initialize subexpression text positions to -1 to mark ones that no
3711 start_memory/stop_memory has been seen for. Also initialize the
3712 register information struct. */
3713 for (mcnt = 1; mcnt < num_regs; mcnt++)
3715 regstart[mcnt] = regend[mcnt]
3716 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3718 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3719 IS_ACTIVE (reg_info[mcnt]) = 0;
3720 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3721 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3724 /* We move `string1' into `string2' if the latter's empty -- but not if
3725 `string1' is null. */
3726 if (size2 == 0 && string1 != NULL)
3733 end1 = string1 + size1;
3734 end2 = string2 + size2;
3736 /* Compute where to stop matching, within the two strings. */
3739 end_match_1 = string1 + stop;
3740 end_match_2 = string2;
3745 end_match_2 = string2 + stop - size1;
3748 /* `p' scans through the pattern as `d' scans through the data.
3749 `dend' is the end of the input string that `d' points within. `d'
3750 is advanced into the following input string whenever necessary, but
3751 this happens before fetching; therefore, at the beginning of the
3752 loop, `d' can be pointing at the end of a string, but it cannot
3754 if (size1 > 0 && pos <= size1)
3761 d = string2 + pos - size1;
3765 DEBUG_PRINT1 ("The compiled pattern is: ");
3766 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3767 DEBUG_PRINT1 ("The string to match is: `");
3768 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3769 DEBUG_PRINT1 ("'\n");
3771 /* This loops over pattern commands. It exits by returning from the
3772 function if the match is complete, or it drops through if the match
3773 fails at this starting point in the input data. */
3776 DEBUG_PRINT2 ("\n0x%x: ", p);
3779 { /* End of pattern means we might have succeeded. */
3780 DEBUG_PRINT1 ("end of pattern ... ");
3782 /* If we haven't matched the entire string, and we want the
3783 longest match, try backtracking. */
3784 if (d != end_match_2)
3786 /* 1 if this match ends in the same string (string1 or string2)
3787 as the best previous match. */
3788 boolean same_str_p = (FIRST_STRING_P (match_end)
3789 == MATCHING_IN_FIRST_STRING);
3790 /* 1 if this match is the best seen so far. */
3791 boolean best_match_p;
3793 /* AIX compiler got confused when this was combined
3794 with the previous declaration. */
3796 best_match_p = d > match_end;
3798 best_match_p = !MATCHING_IN_FIRST_STRING;
3800 DEBUG_PRINT1 ("backtracking.\n");
3802 if (!FAIL_STACK_EMPTY ())
3803 { /* More failure points to try. */
3805 /* If exceeds best match so far, save it. */
3806 if (!best_regs_set || best_match_p)
3808 best_regs_set = true;
3811 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3813 for (mcnt = 1; mcnt < num_regs; mcnt++)
3815 best_regstart[mcnt] = regstart[mcnt];
3816 best_regend[mcnt] = regend[mcnt];
3822 /* If no failure points, don't restore garbage. And if
3823 last match is real best match, don't restore second
3825 else if (best_regs_set && !best_match_p)
3828 /* Restore best match. It may happen that `dend ==
3829 end_match_1' while the restored d is in string2.
3830 For example, the pattern `x.*y.*z' against the
3831 strings `x-' and `y-z-', if the two strings are
3832 not consecutive in memory. */
3833 DEBUG_PRINT1 ("Restoring best registers.\n");
3836 dend = ((d >= string1 && d <= end1)
3837 ? end_match_1 : end_match_2);
3839 for (mcnt = 1; mcnt < num_regs; mcnt++)
3841 regstart[mcnt] = best_regstart[mcnt];
3842 regend[mcnt] = best_regend[mcnt];
3845 } /* d != end_match_2 */
3848 DEBUG_PRINT1 ("Accepting match.\n");
3850 /* If caller wants register contents data back, do it. */
3851 if (regs && !bufp->no_sub)
3853 /* Have the register data arrays been allocated? */
3854 if (bufp->regs_allocated == REGS_UNALLOCATED)
3855 { /* No. So allocate them with malloc. We need one
3856 extra element beyond `num_regs' for the `-1' marker
3858 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3859 regs->start = TALLOC (regs->num_regs, regoff_t);
3860 regs->end = TALLOC (regs->num_regs, regoff_t);
3861 if (regs->start == NULL || regs->end == NULL)
3866 bufp->regs_allocated = REGS_REALLOCATE;
3868 else if (bufp->regs_allocated == REGS_REALLOCATE)
3869 { /* Yes. If we need more elements than were already
3870 allocated, reallocate them. If we need fewer, just
3872 if (regs->num_regs < num_regs + 1)
3874 regs->num_regs = num_regs + 1;
3875 RETALLOC (regs->start, regs->num_regs, regoff_t);
3876 RETALLOC (regs->end, regs->num_regs, regoff_t);
3877 if (regs->start == NULL || regs->end == NULL)
3886 /* These braces fend off a "empty body in an else-statement"
3887 warning under GCC when assert expands to nothing. */
3888 assert (bufp->regs_allocated == REGS_FIXED);
3891 /* Convert the pointer data in `regstart' and `regend' to
3892 indices. Register zero has to be set differently,
3893 since we haven't kept track of any info for it. */
3894 if (regs->num_regs > 0)
3896 regs->start[0] = pos;
3897 regs->end[0] = (MATCHING_IN_FIRST_STRING
3898 ? ((regoff_t) (d - string1))
3899 : ((regoff_t) (d - string2 + size1)));
3902 /* Go through the first `min (num_regs, regs->num_regs)'
3903 registers, since that is all we initialized. */
3904 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3906 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3907 regs->start[mcnt] = regs->end[mcnt] = -1;
3911 = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
3913 = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
3917 /* If the regs structure we return has more elements than
3918 were in the pattern, set the extra elements to -1. If
3919 we (re)allocated the registers, this is the case,
3920 because we always allocate enough to have at least one
3922 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3923 regs->start[mcnt] = regs->end[mcnt] = -1;
3924 } /* regs && !bufp->no_sub */
3926 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3927 nfailure_points_pushed, nfailure_points_popped,
3928 nfailure_points_pushed - nfailure_points_popped);
3929 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3931 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3935 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3941 /* Otherwise match next pattern command. */
3942 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
3944 /* Ignore these. Used to ignore the n of succeed_n's which
3945 currently have n == 0. */
3947 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3951 DEBUG_PRINT1 ("EXECUTING succeed.\n");
3954 /* Match the next n pattern characters exactly. The following
3955 byte in the pattern defines n, and the n bytes after that
3956 are the characters to match. */
3959 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3961 /* This is written out as an if-else so we don't waste time
3962 testing `translate' inside the loop. */
3968 if ((unsigned char) translate[(unsigned char) *d++]
3969 != (unsigned char) *p++)
3979 if (*d++ != (char) *p++) goto fail;
3983 SET_REGS_MATCHED ();
3987 /* Match any character except possibly a newline or a null. */
3989 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3993 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3994 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3997 SET_REGS_MATCHED ();
3998 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
4006 register unsigned char c;
4007 boolean not = (re_opcode_t) *(p - 1) == charset_not;
4009 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
4012 c = TRANSLATE (*d); /* The character to match. */
4014 /* Cast to `unsigned' instead of `unsigned char' in case the
4015 bit list is a full 32 bytes long. */
4016 if (c < (unsigned) (*p * BYTEWIDTH)
4017 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4022 if (!not) goto fail;
4024 SET_REGS_MATCHED ();
4030 /* The beginning of a group is represented by start_memory.
4031 The arguments are the register number in the next byte, and the
4032 number of groups inner to this one in the next. The text
4033 matched within the group is recorded (in the internal
4034 registers data structure) under the register number. */
4036 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
4038 /* Find out if this group can match the empty string. */
4039 p1 = p; /* To send to group_match_null_string_p. */
4041 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
4042 REG_MATCH_NULL_STRING_P (reg_info[*p])
4043 = group_match_null_string_p (&p1, pend, reg_info);
4045 /* Save the position in the string where we were the last time
4046 we were at this open-group operator in case the group is
4047 operated upon by a repetition operator, e.g., with `(a*)*b'
4048 against `ab'; then we want to ignore where we are now in
4049 the string in case this attempt to match fails. */
4050 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4051 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
4053 DEBUG_PRINT2 (" old_regstart: %d\n",
4054 POINTER_TO_OFFSET (old_regstart[*p]));
4057 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
4059 IS_ACTIVE (reg_info[*p]) = 1;
4060 MATCHED_SOMETHING (reg_info[*p]) = 0;
4062 /* Clear this whenever we change the register activity status. */
4063 set_regs_matched_done = 0;
4065 /* This is the new highest active register. */
4066 highest_active_reg = *p;
4068 /* If nothing was active before, this is the new lowest active
4070 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4071 lowest_active_reg = *p;
4073 /* Move past the register number and inner group count. */
4075 just_past_start_mem = p;
4080 /* The stop_memory opcode represents the end of a group. Its
4081 arguments are the same as start_memory's: the register
4082 number, and the number of inner groups. */
4084 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
4086 /* We need to save the string position the last time we were at
4087 this close-group operator in case the group is operated
4088 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
4089 against `aba'; then we want to ignore where we are now in
4090 the string in case this attempt to match fails. */
4091 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4092 ? REG_UNSET (regend[*p]) ? d : regend[*p]
4094 DEBUG_PRINT2 (" old_regend: %d\n",
4095 POINTER_TO_OFFSET (old_regend[*p]));
4098 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
4100 /* This register isn't active anymore. */
4101 IS_ACTIVE (reg_info[*p]) = 0;
4103 /* Clear this whenever we change the register activity status. */
4104 set_regs_matched_done = 0;
4106 /* If this was the only register active, nothing is active
4108 if (lowest_active_reg == highest_active_reg)
4110 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4111 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4114 { /* We must scan for the new highest active register, since
4115 it isn't necessarily one less than now: consider
4116 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
4117 new highest active register is 1. */
4118 unsigned char r = *p - 1;
4119 while (r > 0 && !IS_ACTIVE (reg_info[r]))
4122 /* If we end up at register zero, that means that we saved
4123 the registers as the result of an `on_failure_jump', not
4124 a `start_memory', and we jumped to past the innermost
4125 `stop_memory'. For example, in ((.)*) we save
4126 registers 1 and 2 as a result of the *, but when we pop
4127 back to the second ), we are at the stop_memory 1.
4128 Thus, nothing is active. */
4131 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4132 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4135 highest_active_reg = r;
4138 /* If just failed to match something this time around with a
4139 group that's operated on by a repetition operator, try to
4140 force exit from the ``loop'', and restore the register
4141 information for this group that we had before trying this
4143 if ((!MATCHED_SOMETHING (reg_info[*p])
4144 || just_past_start_mem == p - 1)
4147 boolean is_a_jump_n = false;
4151 switch ((re_opcode_t) *p1++)
4155 case pop_failure_jump:
4156 case maybe_pop_jump:
4158 case dummy_failure_jump:
4159 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4169 /* If the next operation is a jump backwards in the pattern
4170 to an on_failure_jump right before the start_memory
4171 corresponding to this stop_memory, exit from the loop
4172 by forcing a failure after pushing on the stack the
4173 on_failure_jump's jump in the pattern, and d. */
4174 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
4175 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
4177 /* If this group ever matched anything, then restore
4178 what its registers were before trying this last
4179 failed match, e.g., with `(a*)*b' against `ab' for
4180 regstart[1], and, e.g., with `((a*)*(b*)*)*'
4181 against `aba' for regend[3].
4183 Also restore the registers for inner groups for,
4184 e.g., `((a*)(b*))*' against `aba' (register 3 would
4185 otherwise get trashed). */
4187 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
4191 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
4193 /* Restore this and inner groups' (if any) registers. */
4194 for (r = *p; r < *p + *(p + 1); r++)
4196 regstart[r] = old_regstart[r];
4198 /* xx why this test? */
4199 if (old_regend[r] >= regstart[r])
4200 regend[r] = old_regend[r];
4204 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4205 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
4211 /* Move past the register number and the inner group count. */
4216 /* \<digit> has been turned into a `duplicate' command which is
4217 followed by the numeric value of <digit> as the register number. */
4220 register const char *d2, *dend2;
4221 int regno = *p++; /* Get which register to match against. */
4222 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
4224 /* Can't back reference a group which we've never matched. */
4225 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
4228 /* Where in input to try to start matching. */
4229 d2 = regstart[regno];
4231 /* Where to stop matching; if both the place to start and
4232 the place to stop matching are in the same string, then
4233 set to the place to stop, otherwise, for now have to use
4234 the end of the first string. */
4236 dend2 = ((FIRST_STRING_P (regstart[regno])
4237 == FIRST_STRING_P (regend[regno]))
4238 ? regend[regno] : end_match_1);
4241 /* If necessary, advance to next segment in register
4245 if (dend2 == end_match_2) break;
4246 if (dend2 == regend[regno]) break;
4248 /* End of string1 => advance to string2. */
4250 dend2 = regend[regno];
4252 /* At end of register contents => success */
4253 if (d2 == dend2) break;
4255 /* If necessary, advance to next segment in data. */
4258 /* How many characters left in this segment to match. */
4261 /* Want how many consecutive characters we can match in
4262 one shot, so, if necessary, adjust the count. */
4263 if (mcnt > dend2 - d2)
4266 /* Compare that many; failure if mismatch, else move
4269 ? bcmp_translate (d, d2, mcnt, translate)
4270 : bcmp (d, d2, mcnt))
4272 d += mcnt, d2 += mcnt;
4274 /* Do this because we've match some characters. */
4275 SET_REGS_MATCHED ();
4281 /* begline matches the empty string at the beginning of the string
4282 (unless `not_bol' is set in `bufp'), and, if
4283 `newline_anchor' is set, after newlines. */
4285 DEBUG_PRINT1 ("EXECUTING begline.\n");
4287 if (AT_STRINGS_BEG (d))
4289 if (!bufp->not_bol) break;
4291 else if (d[-1] == '\n' && bufp->newline_anchor)
4295 /* In all other cases, we fail. */
4299 /* endline is the dual of begline. */
4301 DEBUG_PRINT1 ("EXECUTING endline.\n");
4303 if (AT_STRINGS_END (d))
4305 if (!bufp->not_eol) break;
4308 /* We have to ``prefetch'' the next character. */
4309 else if ((d == end1 ? *string2 : *d) == '\n'
4310 && bufp->newline_anchor)
4317 /* Match at the very beginning of the data. */
4319 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4320 if (AT_STRINGS_BEG (d))
4325 /* Match at the very end of the data. */
4327 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4328 if (AT_STRINGS_END (d))
4333 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
4334 pushes NULL as the value for the string on the stack. Then
4335 `pop_failure_point' will keep the current value for the
4336 string, instead of restoring it. To see why, consider
4337 matching `foo\nbar' against `.*\n'. The .* matches the foo;
4338 then the . fails against the \n. But the next thing we want
4339 to do is match the \n against the \n; if we restored the
4340 string value, we would be back at the foo.
4342 Because this is used only in specific cases, we don't need to
4343 check all the things that `on_failure_jump' does, to make
4344 sure the right things get saved on the stack. Hence we don't
4345 share its code. The only reason to push anything on the
4346 stack at all is that otherwise we would have to change
4347 `anychar's code to do something besides goto fail in this
4348 case; that seems worse than this. */
4349 case on_failure_keep_string_jump:
4350 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4352 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4353 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4355 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4359 /* Uses of on_failure_jump:
4361 Each alternative starts with an on_failure_jump that points
4362 to the beginning of the next alternative. Each alternative
4363 except the last ends with a jump that in effect jumps past
4364 the rest of the alternatives. (They really jump to the
4365 ending jump of the following alternative, because tensioning
4366 these jumps is a hassle.)
4368 Repeats start with an on_failure_jump that points past both
4369 the repetition text and either the following jump or
4370 pop_failure_jump back to this on_failure_jump. */
4371 case on_failure_jump:
4373 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4375 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4376 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4378 /* If this on_failure_jump comes right before a group (i.e.,
4379 the original * applied to a group), save the information
4380 for that group and all inner ones, so that if we fail back
4381 to this point, the group's information will be correct.
4382 For example, in \(a*\)*\1, we need the preceding group,
4383 and in \(zz\(a*\)b*\)\2, we need the inner group. */
4385 /* We can't use `p' to check ahead because we push
4386 a failure point to `p + mcnt' after we do this. */
4389 /* We need to skip no_op's before we look for the
4390 start_memory in case this on_failure_jump is happening as
4391 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
4393 while (p1 < pend && (re_opcode_t) *p1 == no_op)
4396 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
4398 /* We have a new highest active register now. This will
4399 get reset at the start_memory we are about to get to,
4400 but we will have saved all the registers relevant to
4401 this repetition op, as described above. */
4402 highest_active_reg = *(p1 + 1) + *(p1 + 2);
4403 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4404 lowest_active_reg = *(p1 + 1);
4407 DEBUG_PRINT1 (":\n");
4408 PUSH_FAILURE_POINT (p + mcnt, d, -2);
4412 /* A smart repeat ends with `maybe_pop_jump'.
4413 We change it to either `pop_failure_jump' or `jump'. */
4414 case maybe_pop_jump:
4415 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4416 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4418 register unsigned char *p2 = p;
4420 /* Compare the beginning of the repeat with what in the
4421 pattern follows its end. If we can establish that there
4422 is nothing that they would both match, i.e., that we
4423 would have to backtrack because of (as in, e.g., `a*a')
4424 then we can change to pop_failure_jump, because we'll
4425 never have to backtrack.
4427 This is not true in the case of alternatives: in
4428 `(a|ab)*' we do need to backtrack to the `ab' alternative
4429 (e.g., if the string was `ab'). But instead of trying to
4430 detect that here, the alternative has put on a dummy
4431 failure point which is what we will end up popping. */
4433 /* Skip over open/close-group commands.
4434 If what follows this loop is a ...+ construct,
4435 look at what begins its body, since we will have to
4436 match at least one of that. */
4440 && ((re_opcode_t) *p2 == stop_memory
4441 || (re_opcode_t) *p2 == start_memory))
4443 else if (p2 + 6 < pend
4444 && (re_opcode_t) *p2 == dummy_failure_jump)
4451 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4452 to the `maybe_finalize_jump' of this case. Examine what
4455 /* If we're at the end of the pattern, we can change. */
4458 /* Consider what happens when matching ":\(.*\)"
4459 against ":/". I don't really understand this code
4461 p[-3] = (unsigned char) pop_failure_jump;
4463 (" End of pattern: change to `pop_failure_jump'.\n");
4466 else if ((re_opcode_t) *p2 == exactn
4467 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4469 register unsigned char c
4470 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4472 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4474 p[-3] = (unsigned char) pop_failure_jump;
4475 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4479 else if ((re_opcode_t) p1[3] == charset
4480 || (re_opcode_t) p1[3] == charset_not)
4482 int not = (re_opcode_t) p1[3] == charset_not;
4484 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4485 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4488 /* `not' is equal to 1 if c would match, which means
4489 that we can't change to pop_failure_jump. */
4492 p[-3] = (unsigned char) pop_failure_jump;
4493 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4497 else if ((re_opcode_t) *p2 == charset)
4500 register unsigned char c
4501 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4504 if ((re_opcode_t) p1[3] == exactn
4505 && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
4506 && (p2[1 + p1[4] / BYTEWIDTH]
4507 & (1 << (p1[4] % BYTEWIDTH)))))
4509 p[-3] = (unsigned char) pop_failure_jump;
4510 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4514 else if ((re_opcode_t) p1[3] == charset_not)
4517 /* We win if the charset_not inside the loop
4518 lists every character listed in the charset after. */
4519 for (idx = 0; idx < (int) p2[1]; idx++)
4520 if (! (p2[2 + idx] == 0
4521 || (idx < (int) p1[4]
4522 && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
4527 p[-3] = (unsigned char) pop_failure_jump;
4528 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4531 else if ((re_opcode_t) p1[3] == charset)
4534 /* We win if the charset inside the loop
4535 has no overlap with the one after the loop. */
4537 idx < (int) p2[1] && idx < (int) p1[4];
4539 if ((p2[2 + idx] & p1[5 + idx]) != 0)
4542 if (idx == p2[1] || idx == p1[4])
4544 p[-3] = (unsigned char) pop_failure_jump;
4545 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4550 p -= 2; /* Point at relative address again. */
4551 if ((re_opcode_t) p[-1] != pop_failure_jump)
4553 p[-1] = (unsigned char) jump;
4554 DEBUG_PRINT1 (" Match => jump.\n");
4555 goto unconditional_jump;
4557 /* Note fall through. */
4560 /* The end of a simple repeat has a pop_failure_jump back to
4561 its matching on_failure_jump, where the latter will push a
4562 failure point. The pop_failure_jump takes off failure
4563 points put on by this pop_failure_jump's matching
4564 on_failure_jump; we got through the pattern to here from the
4565 matching on_failure_jump, so didn't fail. */
4566 case pop_failure_jump:
4568 /* We need to pass separate storage for the lowest and
4569 highest registers, even though we don't care about the
4570 actual values. Otherwise, we will restore only one
4571 register from the stack, since lowest will == highest in
4572 `pop_failure_point'. */
4573 unsigned dummy_low_reg, dummy_high_reg;
4574 unsigned char *pdummy;
4577 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4578 POP_FAILURE_POINT (sdummy, pdummy,
4579 dummy_low_reg, dummy_high_reg,
4580 reg_dummy, reg_dummy, reg_info_dummy);
4582 /* Note fall through. */
4585 /* Unconditionally jump (without popping any failure points). */
4588 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4589 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4590 p += mcnt; /* Do the jump. */
4591 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4595 /* We need this opcode so we can detect where alternatives end
4596 in `group_match_null_string_p' et al. */
4598 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4599 goto unconditional_jump;
4602 /* Normally, the on_failure_jump pushes a failure point, which
4603 then gets popped at pop_failure_jump. We will end up at
4604 pop_failure_jump, also, and with a pattern of, say, `a+', we
4605 are skipping over the on_failure_jump, so we have to push
4606 something meaningless for pop_failure_jump to pop. */
4607 case dummy_failure_jump:
4608 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4609 /* It doesn't matter what we push for the string here. What
4610 the code at `fail' tests is the value for the pattern. */
4611 PUSH_FAILURE_POINT (0, 0, -2);
4612 goto unconditional_jump;
4615 /* At the end of an alternative, we need to push a dummy failure
4616 point in case we are followed by a `pop_failure_jump', because
4617 we don't want the failure point for the alternative to be
4618 popped. For example, matching `(a|ab)*' against `aab'
4619 requires that we match the `ab' alternative. */
4620 case push_dummy_failure:
4621 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4622 /* See comments just above at `dummy_failure_jump' about the
4624 PUSH_FAILURE_POINT (0, 0, -2);
4627 /* Have to succeed matching what follows at least n times.
4628 After that, handle like `on_failure_jump'. */
4630 EXTRACT_NUMBER (mcnt, p + 2);
4631 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4634 /* Originally, this is how many times we HAVE to succeed. */
4639 STORE_NUMBER_AND_INCR (p, mcnt);
4640 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4644 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4645 p[2] = (unsigned char) no_op;
4646 p[3] = (unsigned char) no_op;
4652 EXTRACT_NUMBER (mcnt, p + 2);
4653 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4655 /* Originally, this is how many times we CAN jump. */
4659 STORE_NUMBER (p + 2, mcnt);
4660 goto unconditional_jump;
4662 /* If don't have to jump any more, skip over the rest of command. */
4669 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4671 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4673 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4674 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4675 STORE_NUMBER (p1, mcnt);
4680 /* The DEC Alpha C compiler 3.x generates incorrect code for the
4681 test WORDCHAR_P (d - 1) != WORDCHAR_P (d) in the expansion of
4682 AT_WORD_BOUNDARY, so this code is disabled. Expanding the
4683 macro and introducing temporary variables works around the bug. */
4686 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4687 if (AT_WORD_BOUNDARY (d))
4692 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4693 if (AT_WORD_BOUNDARY (d))
4699 boolean prevchar, thischar;
4701 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4702 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4705 prevchar = WORDCHAR_P (d - 1);
4706 thischar = WORDCHAR_P (d);
4707 if (prevchar != thischar)
4714 boolean prevchar, thischar;
4716 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4717 if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
4720 prevchar = WORDCHAR_P (d - 1);
4721 thischar = WORDCHAR_P (d);
4722 if (prevchar != thischar)
4729 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4730 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4735 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4736 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4737 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4743 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4744 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4749 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4750 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4755 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4756 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4761 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4766 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4770 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4772 if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
4774 SET_REGS_MATCHED ();
4778 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4780 goto matchnotsyntax;
4783 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4787 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4789 if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
4791 SET_REGS_MATCHED ();
4794 #else /* not emacs */
4796 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4798 if (!WORDCHAR_P (d))
4800 SET_REGS_MATCHED ();
4805 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4809 SET_REGS_MATCHED ();
4812 #endif /* not emacs */
4817 continue; /* Successfully executed one pattern command; keep going. */
4820 /* We goto here if a matching operation fails. */
4822 if (!FAIL_STACK_EMPTY ())
4823 { /* A restart point is known. Restore to that state. */
4824 DEBUG_PRINT1 ("\nFAIL:\n");
4825 POP_FAILURE_POINT (d, p,
4826 lowest_active_reg, highest_active_reg,
4827 regstart, regend, reg_info);
4829 /* If this failure point is a dummy, try the next one. */
4833 /* If we failed to the end of the pattern, don't examine *p. */
4837 boolean is_a_jump_n = false;
4839 /* If failed to a backwards jump that's part of a repetition
4840 loop, need to pop this failure point and use the next one. */
4841 switch ((re_opcode_t) *p)
4845 case maybe_pop_jump:
4846 case pop_failure_jump:
4849 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4852 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4854 && (re_opcode_t) *p1 == on_failure_jump))
4862 if (d >= string1 && d <= end1)
4866 break; /* Matching at this starting point really fails. */
4870 goto restore_best_regs;
4874 return -1; /* Failure to match. */
4877 /* Subroutine definitions for re_match_2. */
4880 /* We are passed P pointing to a register number after a start_memory.
4882 Return true if the pattern up to the corresponding stop_memory can
4883 match the empty string, and false otherwise.
4885 If we find the matching stop_memory, sets P to point to one past its number.
4886 Otherwise, sets P to an undefined byte less than or equal to END.
4888 We don't handle duplicates properly (yet). */
4891 group_match_null_string_p (p, end, reg_info)
4892 unsigned char **p, *end;
4893 register_info_type *reg_info;
4896 /* Point to after the args to the start_memory. */
4897 unsigned char *p1 = *p + 2;
4901 /* Skip over opcodes that can match nothing, and return true or
4902 false, as appropriate, when we get to one that can't, or to the
4903 matching stop_memory. */
4905 switch ((re_opcode_t) *p1)
4907 /* Could be either a loop or a series of alternatives. */
4908 case on_failure_jump:
4910 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4912 /* If the next operation is not a jump backwards in the
4917 /* Go through the on_failure_jumps of the alternatives,
4918 seeing if any of the alternatives cannot match nothing.
4919 The last alternative starts with only a jump,
4920 whereas the rest start with on_failure_jump and end
4921 with a jump, e.g., here is the pattern for `a|b|c':
4923 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4924 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4927 So, we have to first go through the first (n-1)
4928 alternatives and then deal with the last one separately. */
4931 /* Deal with the first (n-1) alternatives, which start
4932 with an on_failure_jump (see above) that jumps to right
4933 past a jump_past_alt. */
4935 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4937 /* `mcnt' holds how many bytes long the alternative
4938 is, including the ending `jump_past_alt' and
4941 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4945 /* Move to right after this alternative, including the
4949 /* Break if it's the beginning of an n-th alternative
4950 that doesn't begin with an on_failure_jump. */
4951 if ((re_opcode_t) *p1 != on_failure_jump)
4954 /* Still have to check that it's not an n-th
4955 alternative that starts with an on_failure_jump. */
4957 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4958 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4960 /* Get to the beginning of the n-th alternative. */
4966 /* Deal with the last alternative: go back and get number
4967 of the `jump_past_alt' just before it. `mcnt' contains
4968 the length of the alternative. */
4969 EXTRACT_NUMBER (mcnt, p1 - 2);
4971 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4974 p1 += mcnt; /* Get past the n-th alternative. */
4980 assert (p1[1] == **p);
4986 if (!common_op_match_null_string_p (&p1, end, reg_info))
4989 } /* while p1 < end */
4992 } /* group_match_null_string_p */
4995 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4996 It expects P to be the first byte of a single alternative and END one
4997 byte past the last. The alternative can contain groups. */
5000 alt_match_null_string_p (p, end, reg_info)
5001 unsigned char *p, *end;
5002 register_info_type *reg_info;
5005 unsigned char *p1 = p;
5009 /* Skip over opcodes that can match nothing, and break when we get
5010 to one that can't. */
5012 switch ((re_opcode_t) *p1)
5015 case on_failure_jump:
5017 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5022 if (!common_op_match_null_string_p (&p1, end, reg_info))
5025 } /* while p1 < end */
5028 } /* alt_match_null_string_p */
5031 /* Deals with the ops common to group_match_null_string_p and
5032 alt_match_null_string_p.
5034 Sets P to one after the op and its arguments, if any. */
5037 common_op_match_null_string_p (p, end, reg_info)
5038 unsigned char **p, *end;
5039 register_info_type *reg_info;
5044 unsigned char *p1 = *p;
5046 switch ((re_opcode_t) *p1++)
5066 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
5067 ret = group_match_null_string_p (&p1, end, reg_info);
5069 /* Have to set this here in case we're checking a group which
5070 contains a group and a back reference to it. */
5072 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
5073 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
5079 /* If this is an optimized succeed_n for zero times, make the jump. */
5081 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5089 /* Get to the number of times to succeed. */
5091 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5096 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5104 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
5112 /* All other opcodes mean we cannot match the empty string. */
5118 } /* common_op_match_null_string_p */
5121 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
5122 bytes; nonzero otherwise. */
5125 bcmp_translate (s1, s2, len, translate)
5126 unsigned char *s1, *s2;
5128 RE_TRANSLATE_TYPE translate;
5130 register unsigned char *p1 = s1, *p2 = s2;
5133 if (translate[*p1++] != translate[*p2++]) return 1;
5139 /* Entry points for GNU code. */
5141 /* re_compile_pattern is the GNU regular expression compiler: it
5142 compiles PATTERN (of length SIZE) and puts the result in BUFP.
5143 Returns 0 if the pattern was valid, otherwise an error string.
5145 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
5146 are set in BUFP on entry.
5148 We call regex_compile to do the actual compilation. */
5151 re_compile_pattern (pattern, length, bufp)
5152 const char *pattern;
5154 struct re_pattern_buffer *bufp;
5158 /* GNU code is written to assume at least RE_NREGS registers will be set
5159 (and at least one extra will be -1). */
5160 bufp->regs_allocated = REGS_UNALLOCATED;
5162 /* And GNU code determines whether or not to get register information
5163 by passing null for the REGS argument to re_match, etc., not by
5167 /* Match anchors at newline. */
5168 bufp->newline_anchor = 1;
5170 ret = regex_compile (pattern, length, re_syntax_options, bufp);
5174 return gettext (re_error_msgid[(int) ret]);
5177 /* Entry points compatible with 4.2 BSD regex library. We don't define
5178 them unless specifically requested. */
5180 #ifdef _REGEX_RE_COMP
5182 /* BSD has one and only one pattern buffer. */
5183 static struct re_pattern_buffer re_comp_buf;
5193 if (!re_comp_buf.buffer)
5194 return gettext ("No previous regular expression");
5198 if (!re_comp_buf.buffer)
5200 re_comp_buf.buffer = (unsigned char *) malloc (200);
5201 if (re_comp_buf.buffer == NULL)
5202 return gettext (re_error_msgid[(int) REG_ESPACE]);
5203 re_comp_buf.allocated = 200;
5205 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
5206 if (re_comp_buf.fastmap == NULL)
5207 return gettext (re_error_msgid[(int) REG_ESPACE]);
5210 /* Since `re_exec' always passes NULL for the `regs' argument, we
5211 don't need to initialize the pattern buffer fields which affect it. */
5213 /* Match anchors at newlines. */
5214 re_comp_buf.newline_anchor = 1;
5216 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
5221 /* Yes, we're discarding `const' here if !HAVE_LIBINTL. */
5222 return (char *) gettext (re_error_msgid[(int) ret]);
5230 const int len = strlen (s);
5232 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
5234 #endif /* _REGEX_RE_COMP */
5236 /* POSIX.2 functions. Don't define these for Emacs. */
5240 /* regcomp takes a regular expression as a string and compiles it.
5242 PREG is a regex_t *. We do not expect any fields to be initialized,
5243 since POSIX says we shouldn't. Thus, we set
5245 `buffer' to the compiled pattern;
5246 `used' to the length of the compiled pattern;
5247 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
5248 REG_EXTENDED bit in CFLAGS is set; otherwise, to
5249 RE_SYNTAX_POSIX_BASIC;
5250 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
5251 `fastmap' and `fastmap_accurate' to zero;
5252 `re_nsub' to the number of subexpressions in PATTERN.
5254 PATTERN is the address of the pattern string.
5256 CFLAGS is a series of bits which affect compilation.
5258 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
5259 use POSIX basic syntax.
5261 If REG_NEWLINE is set, then . and [^...] don't match newline.
5262 Also, regexec will try a match beginning after every newline.
5264 If REG_ICASE is set, then we considers upper- and lowercase
5265 versions of letters to be equivalent when matching.
5267 If REG_NOSUB is set, then when PREG is passed to regexec, that
5268 routine will report only success or failure, and nothing about the
5271 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
5272 the return codes and their meanings.) */
5275 regcomp (preg, pattern, cflags)
5277 const char *pattern;
5282 = (cflags & REG_EXTENDED) ?
5283 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
5285 /* regex_compile will allocate the space for the compiled pattern. */
5287 preg->allocated = 0;
5290 /* Don't bother to use a fastmap when searching. This simplifies the
5291 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
5292 characters after newlines into the fastmap. This way, we just try
5296 if (cflags & REG_ICASE)
5301 = (RE_TRANSLATE_TYPE) malloc (CHAR_SET_SIZE
5302 * sizeof (*(RE_TRANSLATE_TYPE)0));
5303 if (preg->translate == NULL)
5304 return (int) REG_ESPACE;
5306 /* Map uppercase characters to corresponding lowercase ones. */
5307 for (i = 0; i < CHAR_SET_SIZE; i++)
5308 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
5311 preg->translate = NULL;
5313 /* If REG_NEWLINE is set, newlines are treated differently. */
5314 if (cflags & REG_NEWLINE)
5315 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
5316 syntax &= ~RE_DOT_NEWLINE;
5317 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
5318 /* It also changes the matching behavior. */
5319 preg->newline_anchor = 1;
5322 preg->newline_anchor = 0;
5324 preg->no_sub = !!(cflags & REG_NOSUB);
5326 /* POSIX says a null character in the pattern terminates it, so we
5327 can use strlen here in compiling the pattern. */
5328 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
5330 /* POSIX doesn't distinguish between an unmatched open-group and an
5331 unmatched close-group: both are REG_EPAREN. */
5332 if (ret == REG_ERPAREN) ret = REG_EPAREN;
5338 /* regexec searches for a given pattern, specified by PREG, in the
5341 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
5342 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
5343 least NMATCH elements, and we set them to the offsets of the
5344 corresponding matched substrings.
5346 EFLAGS specifies `execution flags' which affect matching: if
5347 REG_NOTBOL is set, then ^ does not match at the beginning of the
5348 string; if REG_NOTEOL is set, then $ does not match at the end.
5350 We return 0 if we find a match and REG_NOMATCH if not. */
5353 regexec (preg, string, nmatch, pmatch, eflags)
5354 const regex_t *preg;
5357 regmatch_t pmatch[];
5361 struct re_registers regs;
5362 regex_t private_preg;
5363 int len = strlen (string);
5364 boolean want_reg_info = !preg->no_sub && nmatch > 0;
5366 private_preg = *preg;
5368 private_preg.not_bol = !!(eflags & REG_NOTBOL);
5369 private_preg.not_eol = !!(eflags & REG_NOTEOL);
5371 /* The user has told us exactly how many registers to return
5372 information about, via `nmatch'. We have to pass that on to the
5373 matching routines. */
5374 private_preg.regs_allocated = REGS_FIXED;
5378 regs.num_regs = nmatch;
5379 regs.start = TALLOC (nmatch, regoff_t);
5380 regs.end = TALLOC (nmatch, regoff_t);
5381 if (regs.start == NULL || regs.end == NULL)
5382 return (int) REG_NOMATCH;
5385 /* Perform the searching operation. */
5386 ret = re_search (&private_preg, string, len,
5387 /* start: */ 0, /* range: */ len,
5388 want_reg_info ? ®s : (struct re_registers *) 0);
5390 /* Copy the register information to the POSIX structure. */
5397 for (r = 0; r < nmatch; r++)
5399 pmatch[r].rm_so = regs.start[r];
5400 pmatch[r].rm_eo = regs.end[r];
5404 /* If we needed the temporary register info, free the space now. */
5409 /* We want zero return to mean success, unlike `re_search'. */
5410 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5414 /* Returns a message corresponding to an error code, ERRCODE, returned
5415 from either regcomp or regexec. We don't use PREG here. */
5418 regerror (errcode, preg, errbuf, errbuf_size)
5420 const regex_t *preg;
5428 || errcode >= (sizeof (re_error_msgid) / sizeof (re_error_msgid[0])))
5429 /* Only error codes returned by the rest of the code should be passed
5430 to this routine. If we are given anything else, or if other regex
5431 code generates an invalid error code, then the program has a bug.
5432 Dump core so we can fix it. */
5435 msg = gettext (re_error_msgid[errcode]);
5437 msg_size = strlen (msg) + 1; /* Includes the null. */
5439 if (errbuf_size != 0)
5441 if (msg_size > errbuf_size)
5443 strncpy (errbuf, msg, errbuf_size - 1);
5444 errbuf[errbuf_size - 1] = 0;
5447 strcpy (errbuf, msg);
5454 /* Free dynamically allocated space used by PREG. */
5460 if (preg->buffer != NULL)
5461 free (preg->buffer);
5462 preg->buffer = NULL;
5464 preg->allocated = 0;
5467 if (preg->fastmap != NULL)
5468 free (preg->fastmap);
5469 preg->fastmap = NULL;
5470 preg->fastmap_accurate = 0;
5472 if (preg->translate != NULL)
5473 free (preg->translate);
5474 preg->translate = NULL;
5477 #endif /* not emacs */
5481 make-backup-files: t
5483 trim-versions-without-asking: nil