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 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
22 /* AIX requires this to be the first thing in the file. */
23 #if defined (_AIX) && !defined (REGEX_MALLOC)
33 /* We need this for `regex.h', and perhaps for the Emacs include files. */
34 #include <sys/types.h>
36 /* This is for other GNU distributions with internationalized messages.
37 The GNU C Library itself does not yet support such messages. */
41 # define gettext(msgid) (msgid)
44 /* The `emacs' switch turns on certain matching commands
45 that make sense only in Emacs. */
54 /* If we are not linking with Emacs proper,
55 we can't use the relocating allocator
56 even if config.h says that we can. */
66 /* We used to test for `BSTRING' here, but only GCC and Emacs define
67 `BSTRING', as far as I know, and neither of them use this code. */
68 #ifndef INHIBIT_STRING_HEADER
69 #if HAVE_STRING_H || STDC_HEADERS
72 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
75 #define bcopy(s, d, n) memcpy ((d), (s), (n))
78 #define bzero(s, n) memset ((s), 0, (n))
85 /* Define the syntax stuff for \<, \>, etc. */
87 /* This must be nonzero for the wordchar and notwordchar pattern
88 commands in re_match_2. */
93 #ifdef SWITCH_ENUM_BUG
94 #define SWITCH_ENUM_CAST(x) ((int)(x))
96 #define SWITCH_ENUM_CAST(x) (x)
101 extern char *re_syntax_table;
103 #else /* not SYNTAX_TABLE */
105 /* How many characters in the character set. */
106 #define CHAR_SET_SIZE 256
108 static char re_syntax_table[CHAR_SET_SIZE];
119 bzero (re_syntax_table, sizeof re_syntax_table);
121 for (c = 'a'; c <= 'z'; c++)
122 re_syntax_table[c] = Sword;
124 for (c = 'A'; c <= 'Z'; c++)
125 re_syntax_table[c] = Sword;
127 for (c = '0'; c <= '9'; c++)
128 re_syntax_table[c] = Sword;
130 re_syntax_table['_'] = Sword;
135 #endif /* not SYNTAX_TABLE */
137 #define SYNTAX(c) re_syntax_table[c]
139 #endif /* not emacs */
141 /* Get the interface, including the syntax bits. */
144 /* isalpha etc. are used for the character classes. */
147 /* Jim Meyering writes:
149 "... Some ctype macros are valid only for character codes that
150 isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
151 using /bin/cc or gcc but without giving an ansi option). So, all
152 ctype uses should be through macros like ISPRINT... If
153 STDC_HEADERS is defined, then autoconf has verified that the ctype
154 macros don't need to be guarded with references to isascii. ...
155 Defining isascii to 1 should let any compiler worth its salt
156 eliminate the && through constant folding." */
158 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
161 #define ISASCII(c) isascii(c)
165 #define ISBLANK(c) (ISASCII (c) && isblank (c))
167 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
170 #define ISGRAPH(c) (ISASCII (c) && isgraph (c))
172 #define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
175 #define ISPRINT(c) (ISASCII (c) && isprint (c))
176 #define ISDIGIT(c) (ISASCII (c) && isdigit (c))
177 #define ISALNUM(c) (ISASCII (c) && isalnum (c))
178 #define ISALPHA(c) (ISASCII (c) && isalpha (c))
179 #define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
180 #define ISLOWER(c) (ISASCII (c) && islower (c))
181 #define ISPUNCT(c) (ISASCII (c) && ispunct (c))
182 #define ISSPACE(c) (ISASCII (c) && isspace (c))
183 #define ISUPPER(c) (ISASCII (c) && isupper (c))
184 #define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
190 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
191 since ours (we hope) works properly with all combinations of
192 machines, compilers, `char' and `unsigned char' argument types.
193 (Per Bothner suggested the basic approach.) */
194 #undef SIGN_EXTEND_CHAR
196 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
197 #else /* not __STDC__ */
198 /* As in Harbison and Steele. */
199 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
202 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
203 use `alloca' instead of `malloc'. This is because using malloc in
204 re_search* or re_match* could cause memory leaks when C-g is used in
205 Emacs; also, malloc is slower and causes storage fragmentation. On
206 the other hand, malloc is more portable, and easier to debug.
208 Because we sometimes use alloca, some routines have to be macros,
209 not functions -- `alloca'-allocated space disappears at the end of the
210 function it is called in. */
214 #define REGEX_ALLOCATE malloc
215 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
216 #define REGEX_FREE free
218 #else /* not REGEX_MALLOC */
220 /* Emacs already defines alloca, sometimes. */
223 /* Make alloca work the best possible way. */
225 #define alloca __builtin_alloca
226 #else /* not __GNUC__ */
229 #else /* not __GNUC__ or HAVE_ALLOCA_H */
230 #ifndef _AIX /* Already did AIX, up at the top. */
232 #endif /* not _AIX */
233 #endif /* not HAVE_ALLOCA_H */
234 #endif /* not __GNUC__ */
236 #endif /* not alloca */
238 #define REGEX_ALLOCATE alloca
240 /* Assumes a `char *destination' variable. */
241 #define REGEX_REALLOCATE(source, osize, nsize) \
242 (destination = (char *) alloca (nsize), \
243 bcopy (source, destination, osize), \
246 /* No need to do anything to free, after alloca. */
247 #define REGEX_FREE(arg) (0)
249 #endif /* not REGEX_MALLOC */
251 /* Define how to allocate the failure stack. */
254 #define REGEX_ALLOCATE_STACK(size) \
255 r_alloc (&failure_stack_ptr, (size))
256 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
257 r_re_alloc (&failure_stack_ptr, (nsize))
258 #define REGEX_FREE_STACK(ptr) \
259 r_alloc_free (&failure_stack_ptr)
261 #else /* not REL_ALLOC */
265 #define REGEX_ALLOCATE_STACK malloc
266 #define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
267 #define REGEX_FREE_STACK free
269 #else /* not REGEX_MALLOC */
271 #define REGEX_ALLOCATE_STACK alloca
273 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
274 REGEX_REALLOCATE (source, osize, nsize)
275 /* No need to explicitly free anything. */
276 #define REGEX_FREE_STACK(arg)
278 #endif /* not REGEX_MALLOC */
279 #endif /* not REL_ALLOC */
282 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
283 `string1' or just past its end. This works if PTR is NULL, which is
285 #define FIRST_STRING_P(ptr) \
286 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
288 /* (Re)Allocate N items of type T using malloc, or fail. */
289 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
290 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
291 #define RETALLOC_IF(addr, n, t) \
292 if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
293 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
295 #define BYTEWIDTH 8 /* In bits. */
297 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
301 #define MAX(a, b) ((a) > (b) ? (a) : (b))
302 #define MIN(a, b) ((a) < (b) ? (a) : (b))
304 typedef char boolean;
308 static int re_match_2_internal ();
310 /* These are the command codes that appear in compiled regular
311 expressions. Some opcodes are followed by argument bytes. A
312 command code can specify any interpretation whatsoever for its
313 arguments. Zero bytes may appear in the compiled regular expression. */
319 /* Succeed right away--no more backtracking. */
322 /* Followed by one byte giving n, then by n literal bytes. */
325 /* Matches any (more or less) character. */
328 /* Matches any one char belonging to specified set. First
329 following byte is number of bitmap bytes. Then come bytes
330 for a bitmap saying which chars are in. Bits in each byte
331 are ordered low-bit-first. A character is in the set if its
332 bit is 1. A character too large to have a bit in the map is
333 automatically not in the set. */
336 /* Same parameters as charset, but match any character that is
337 not one of those specified. */
340 /* Start remembering the text that is matched, for storing in a
341 register. Followed by one byte with the register number, in
342 the range 0 to one less than the pattern buffer's re_nsub
343 field. Then followed by one byte with the number of groups
344 inner to this one. (This last has to be part of the
345 start_memory only because we need it in the on_failure_jump
349 /* Stop remembering the text that is matched and store it in a
350 memory register. Followed by one byte with the register
351 number, in the range 0 to one less than `re_nsub' in the
352 pattern buffer, and one byte with the number of inner groups,
353 just like `start_memory'. (We need the number of inner
354 groups here because we don't have any easy way of finding the
355 corresponding start_memory when we're at a stop_memory.) */
358 /* Match a duplicate of something remembered. Followed by one
359 byte containing the register number. */
362 /* Fail unless at beginning of line. */
365 /* Fail unless at end of line. */
368 /* Succeeds if at beginning of buffer (if emacs) or at beginning
369 of string to be matched (if not). */
372 /* Analogously, for end of buffer/string. */
375 /* Followed by two byte relative address to which to jump. */
378 /* Same as jump, but marks the end of an alternative. */
381 /* Followed by two-byte relative address of place to resume at
382 in case of failure. */
385 /* Like on_failure_jump, but pushes a placeholder instead of the
386 current string position when executed. */
387 on_failure_keep_string_jump,
389 /* Throw away latest failure point and then jump to following
390 two-byte relative address. */
393 /* Change to pop_failure_jump if know won't have to backtrack to
394 match; otherwise change to jump. This is used to jump
395 back to the beginning of a repeat. If what follows this jump
396 clearly won't match what the repeat does, such that we can be
397 sure that there is no use backtracking out of repetitions
398 already matched, then we change it to a pop_failure_jump.
399 Followed by two-byte address. */
402 /* Jump to following two-byte address, and push a dummy failure
403 point. This failure point will be thrown away if an attempt
404 is made to use it for a failure. A `+' construct makes this
405 before the first repeat. Also used as an intermediary kind
406 of jump when compiling an alternative. */
409 /* Push a dummy failure point and continue. Used at the end of
413 /* Followed by two-byte relative address and two-byte number n.
414 After matching N times, jump to the address upon failure. */
417 /* Followed by two-byte relative address, and two-byte number n.
418 Jump to the address N times, then fail. */
421 /* Set the following two-byte relative address to the
422 subsequent two-byte number. The address *includes* the two
426 wordchar, /* Matches any word-constituent character. */
427 notwordchar, /* Matches any char that is not a word-constituent. */
429 wordbeg, /* Succeeds if at word beginning. */
430 wordend, /* Succeeds if at word end. */
432 wordbound, /* Succeeds if at a word boundary. */
433 notwordbound /* Succeeds if not at a word boundary. */
436 ,before_dot, /* Succeeds if before point. */
437 at_dot, /* Succeeds if at point. */
438 after_dot, /* Succeeds if after point. */
440 /* Matches any character whose syntax is specified. Followed by
441 a byte which contains a syntax code, e.g., Sword. */
444 /* Matches any character whose syntax is not that specified. */
449 /* Common operations on the compiled pattern. */
451 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
453 #define STORE_NUMBER(destination, number) \
455 (destination)[0] = (number) & 0377; \
456 (destination)[1] = (number) >> 8; \
459 /* Same as STORE_NUMBER, except increment DESTINATION to
460 the byte after where the number is stored. Therefore, DESTINATION
461 must be an lvalue. */
463 #define STORE_NUMBER_AND_INCR(destination, number) \
465 STORE_NUMBER (destination, number); \
466 (destination) += 2; \
469 /* Put into DESTINATION a number stored in two contiguous bytes starting
472 #define EXTRACT_NUMBER(destination, source) \
474 (destination) = *(source) & 0377; \
475 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
480 extract_number (dest, source)
482 unsigned char *source;
484 int temp = SIGN_EXTEND_CHAR (*(source + 1));
485 *dest = *source & 0377;
489 #ifndef EXTRACT_MACROS /* To debug the macros. */
490 #undef EXTRACT_NUMBER
491 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
492 #endif /* not EXTRACT_MACROS */
496 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
497 SOURCE must be an lvalue. */
499 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
501 EXTRACT_NUMBER (destination, source); \
507 extract_number_and_incr (destination, source)
509 unsigned char **source;
511 extract_number (destination, *source);
515 #ifndef EXTRACT_MACROS
516 #undef EXTRACT_NUMBER_AND_INCR
517 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
518 extract_number_and_incr (&dest, &src)
519 #endif /* not EXTRACT_MACROS */
523 /* If DEBUG is defined, Regex prints many voluminous messages about what
524 it is doing (if the variable `debug' is nonzero). If linked with the
525 main program in `iregex.c', you can enter patterns and strings
526 interactively. And if linked with the main program in `main.c' and
527 the other test files, you can run the already-written tests. */
531 /* We use standard I/O for debugging. */
534 /* It is useful to test things that ``must'' be true when debugging. */
537 static int debug = 0;
539 #define DEBUG_STATEMENT(e) e
540 #define DEBUG_PRINT1(x) if (debug) printf (x)
541 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
542 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
543 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
544 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
545 if (debug) print_partial_compiled_pattern (s, e)
546 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
547 if (debug) print_double_string (w, s1, sz1, s2, sz2)
550 /* Print the fastmap in human-readable form. */
553 print_fastmap (fastmap)
556 unsigned was_a_range = 0;
559 while (i < (1 << BYTEWIDTH))
565 while (i < (1 << BYTEWIDTH) && fastmap[i])
581 /* Print a compiled pattern string in human-readable form, starting at
582 the START pointer into it and ending just before the pointer END. */
585 print_partial_compiled_pattern (start, end)
586 unsigned char *start;
590 unsigned char *p = start;
591 unsigned char *pend = end;
599 /* Loop over pattern commands. */
602 printf ("%d:\t", p - start);
604 switch ((re_opcode_t) *p++)
612 printf ("/exactn/%d", mcnt);
623 printf ("/start_memory/%d/%d", mcnt, *p++);
628 printf ("/stop_memory/%d/%d", mcnt, *p++);
632 printf ("/duplicate/%d", *p++);
642 register int c, last = -100;
643 register int in_range = 0;
645 printf ("/charset [%s",
646 (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
648 assert (p + *p < pend);
650 for (c = 0; c < 256; c++)
652 && (p[1 + (c/8)] & (1 << (c % 8))))
654 /* Are we starting a range? */
655 if (last + 1 == c && ! in_range)
660 /* Have we broken a range? */
661 else if (last + 1 != c && in_range)
690 case on_failure_jump:
691 extract_number_and_incr (&mcnt, &p);
692 printf ("/on_failure_jump to %d", p + mcnt - start);
695 case on_failure_keep_string_jump:
696 extract_number_and_incr (&mcnt, &p);
697 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
700 case dummy_failure_jump:
701 extract_number_and_incr (&mcnt, &p);
702 printf ("/dummy_failure_jump to %d", p + mcnt - start);
705 case push_dummy_failure:
706 printf ("/push_dummy_failure");
710 extract_number_and_incr (&mcnt, &p);
711 printf ("/maybe_pop_jump to %d", p + mcnt - start);
714 case pop_failure_jump:
715 extract_number_and_incr (&mcnt, &p);
716 printf ("/pop_failure_jump to %d", p + mcnt - start);
720 extract_number_and_incr (&mcnt, &p);
721 printf ("/jump_past_alt to %d", p + mcnt - start);
725 extract_number_and_incr (&mcnt, &p);
726 printf ("/jump to %d", p + mcnt - start);
730 extract_number_and_incr (&mcnt, &p);
731 extract_number_and_incr (&mcnt2, &p);
732 printf ("/succeed_n to %d, %d times", p + mcnt - start, mcnt2);
736 extract_number_and_incr (&mcnt, &p);
737 extract_number_and_incr (&mcnt2, &p);
738 printf ("/jump_n to %d, %d times", p + mcnt - start, mcnt2);
742 extract_number_and_incr (&mcnt, &p);
743 extract_number_and_incr (&mcnt2, &p);
744 printf ("/set_number_at location %d to %d", p + mcnt - start, mcnt2);
748 printf ("/wordbound");
752 printf ("/notwordbound");
764 printf ("/before_dot");
772 printf ("/after_dot");
776 printf ("/syntaxspec");
778 printf ("/%d", mcnt);
782 printf ("/notsyntaxspec");
784 printf ("/%d", mcnt);
789 printf ("/wordchar");
793 printf ("/notwordchar");
805 printf ("?%d", *(p-1));
811 printf ("%d:\tend of pattern.\n", p - start);
816 print_compiled_pattern (bufp)
817 struct re_pattern_buffer *bufp;
819 unsigned char *buffer = bufp->buffer;
821 print_partial_compiled_pattern (buffer, buffer + bufp->used);
822 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
824 if (bufp->fastmap_accurate && bufp->fastmap)
826 printf ("fastmap: ");
827 print_fastmap (bufp->fastmap);
830 printf ("re_nsub: %d\t", bufp->re_nsub);
831 printf ("regs_alloc: %d\t", bufp->regs_allocated);
832 printf ("can_be_null: %d\t", bufp->can_be_null);
833 printf ("newline_anchor: %d\n", bufp->newline_anchor);
834 printf ("no_sub: %d\t", bufp->no_sub);
835 printf ("not_bol: %d\t", bufp->not_bol);
836 printf ("not_eol: %d\t", bufp->not_eol);
837 printf ("syntax: %d\n", bufp->syntax);
838 /* Perhaps we should print the translate table? */
843 print_double_string (where, string1, size1, string2, size2)
856 if (FIRST_STRING_P (where))
858 for (this_char = where - string1; this_char < size1; this_char++)
859 putchar (string1[this_char]);
864 for (this_char = where - string2; this_char < size2; this_char++)
865 putchar (string2[this_char]);
869 #else /* not DEBUG */
874 #define DEBUG_STATEMENT(e)
875 #define DEBUG_PRINT1(x)
876 #define DEBUG_PRINT2(x1, x2)
877 #define DEBUG_PRINT3(x1, x2, x3)
878 #define DEBUG_PRINT4(x1, x2, x3, x4)
879 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
880 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
882 #endif /* not DEBUG */
884 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
885 also be assigned to arbitrarily: each pattern buffer stores its own
886 syntax, so it can be changed between regex compilations. */
887 /* This has no initializer because initialized variables in Emacs
888 become read-only after dumping. */
889 reg_syntax_t re_syntax_options;
892 /* Specify the precise syntax of regexps for compilation. This provides
893 for compatibility for various utilities which historically have
894 different, incompatible syntaxes.
896 The argument SYNTAX is a bit mask comprised of the various bits
897 defined in regex.h. We return the old syntax. */
900 re_set_syntax (syntax)
903 reg_syntax_t ret = re_syntax_options;
905 re_syntax_options = syntax;
909 /* This table gives an error message for each of the error codes listed
910 in regex.h. Obviously the order here has to be same as there.
911 POSIX doesn't require that we do anything for REG_NOERROR,
912 but why not be nice? */
914 static const char *re_error_msgid[] =
915 { "Success", /* REG_NOERROR */
916 "No match", /* REG_NOMATCH */
917 "Invalid regular expression", /* REG_BADPAT */
918 "Invalid collation character", /* REG_ECOLLATE */
919 "Invalid character class name", /* REG_ECTYPE */
920 "Trailing backslash", /* REG_EESCAPE */
921 "Invalid back reference", /* REG_ESUBREG */
922 "Unmatched [ or [^", /* REG_EBRACK */
923 "Unmatched ( or \\(", /* REG_EPAREN */
924 "Unmatched \\{", /* REG_EBRACE */
925 "Invalid content of \\{\\}", /* REG_BADBR */
926 "Invalid range end", /* REG_ERANGE */
927 "Memory exhausted", /* REG_ESPACE */
928 "Invalid preceding regular expression", /* REG_BADRPT */
929 "Premature end of regular expression", /* REG_EEND */
930 "Regular expression too big", /* REG_ESIZE */
931 "Unmatched ) or \\)", /* REG_ERPAREN */
934 /* Avoiding alloca during matching, to placate r_alloc. */
936 /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
937 searching and matching functions should not call alloca. On some
938 systems, alloca is implemented in terms of malloc, and if we're
939 using the relocating allocator routines, then malloc could cause a
940 relocation, which might (if the strings being searched are in the
941 ralloc heap) shift the data out from underneath the regexp
944 Here's another reason to avoid allocation: Emacs
945 processes input from X in a signal handler; processing X input may
946 call malloc; if input arrives while a matching routine is calling
947 malloc, then we're scrod. But Emacs can't just block input while
948 calling matching routines; then we don't notice interrupts when
949 they come in. So, Emacs blocks input around all regexp calls
950 except the matching calls, which it leaves unprotected, in the
951 faith that they will not malloc. */
953 /* Normally, this is fine. */
954 #define MATCH_MAY_ALLOCATE
956 /* When using GNU C, we are not REALLY using the C alloca, no matter
957 what config.h may say. So don't take precautions for it. */
962 /* The match routines may not allocate if (1) they would do it with malloc
963 and (2) it's not safe for them to use malloc.
964 Note that if REL_ALLOC is defined, matching would not use malloc for the
965 failure stack, but we would still use it for the register vectors;
966 so REL_ALLOC should not affect this. */
967 #if (defined (C_ALLOCA) || defined (REGEX_MALLOC)) && defined (emacs)
968 #undef MATCH_MAY_ALLOCATE
972 /* Failure stack declarations and macros; both re_compile_fastmap and
973 re_match_2 use a failure stack. These have to be macros because of
974 REGEX_ALLOCATE_STACK. */
977 /* Number of failure points for which to initially allocate space
978 when matching. If this number is exceeded, we allocate more
979 space, so it is not a hard limit. */
980 #ifndef INIT_FAILURE_ALLOC
981 #define INIT_FAILURE_ALLOC 5
984 /* Roughly the maximum number of failure points on the stack. Would be
985 exactly that if always used MAX_FAILURE_SPACE each time we failed.
986 This is a variable only so users of regex can assign to it; we never
987 change it ourselves. */
988 #if defined (MATCH_MAY_ALLOCATE)
989 int re_max_failures = 200000;
991 int re_max_failures = 2000;
996 unsigned char *pointer;
1000 typedef union fail_stack_elt fail_stack_elt_t;
1004 fail_stack_elt_t *stack;
1006 unsigned avail; /* Offset of next open position. */
1009 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
1010 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
1011 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
1014 /* Define macros to initialize and free the failure stack.
1015 Do `return -2' if the alloc fails. */
1017 #ifdef MATCH_MAY_ALLOCATE
1018 #define INIT_FAIL_STACK() \
1020 fail_stack.stack = (fail_stack_elt_t *) \
1021 REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
1023 if (fail_stack.stack == NULL) \
1026 fail_stack.size = INIT_FAILURE_ALLOC; \
1027 fail_stack.avail = 0; \
1030 #define RESET_FAIL_STACK() REGEX_FREE_STACK (fail_stack.stack)
1032 #define INIT_FAIL_STACK() \
1034 fail_stack.avail = 0; \
1037 #define RESET_FAIL_STACK()
1041 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
1043 Return 1 if succeeds, and 0 if either ran out of memory
1044 allocating space for it or it was already too large.
1046 REGEX_REALLOCATE_STACK requires `destination' be declared. */
1048 #define DOUBLE_FAIL_STACK(fail_stack) \
1049 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
1051 : ((fail_stack).stack = (fail_stack_elt_t *) \
1052 REGEX_REALLOCATE_STACK ((fail_stack).stack, \
1053 (fail_stack).size * sizeof (fail_stack_elt_t), \
1054 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
1056 (fail_stack).stack == NULL \
1058 : ((fail_stack).size <<= 1, \
1062 /* Push pointer POINTER on FAIL_STACK.
1063 Return 1 if was able to do so and 0 if ran out of memory allocating
1065 #define PUSH_PATTERN_OP(POINTER, FAIL_STACK) \
1066 ((FAIL_STACK_FULL () \
1067 && !DOUBLE_FAIL_STACK (FAIL_STACK)) \
1069 : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER, \
1072 /* Push a pointer value onto the failure stack.
1073 Assumes the variable `fail_stack'. Probably should only
1074 be called from within `PUSH_FAILURE_POINT'. */
1075 #define PUSH_FAILURE_POINTER(item) \
1076 fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
1078 /* This pushes an integer-valued item onto the failure stack.
1079 Assumes the variable `fail_stack'. Probably should only
1080 be called from within `PUSH_FAILURE_POINT'. */
1081 #define PUSH_FAILURE_INT(item) \
1082 fail_stack.stack[fail_stack.avail++].integer = (item)
1084 /* Push a fail_stack_elt_t value onto the failure stack.
1085 Assumes the variable `fail_stack'. Probably should only
1086 be called from within `PUSH_FAILURE_POINT'. */
1087 #define PUSH_FAILURE_ELT(item) \
1088 fail_stack.stack[fail_stack.avail++] = (item)
1090 /* These three POP... operations complement the three PUSH... operations.
1091 All assume that `fail_stack' is nonempty. */
1092 #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
1093 #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
1094 #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
1096 /* Used to omit pushing failure point id's when we're not debugging. */
1098 #define DEBUG_PUSH PUSH_FAILURE_INT
1099 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT ()
1101 #define DEBUG_PUSH(item)
1102 #define DEBUG_POP(item_addr)
1106 /* Push the information about the state we will need
1107 if we ever fail back to it.
1109 Requires variables fail_stack, regstart, regend, reg_info, and
1110 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
1113 Does `return FAILURE_CODE' if runs out of memory. */
1115 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1117 char *destination; \
1118 /* Must be int, so when we don't save any registers, the arithmetic \
1119 of 0 + -1 isn't done as unsigned. */ \
1122 DEBUG_STATEMENT (failure_id++); \
1123 DEBUG_STATEMENT (nfailure_points_pushed++); \
1124 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1125 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1126 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1128 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
1129 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1131 /* Ensure we have enough space allocated for what we will push. */ \
1132 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1134 if (!DOUBLE_FAIL_STACK (fail_stack)) \
1135 return failure_code; \
1137 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1138 (fail_stack).size); \
1139 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1142 /* Push the info, starting with the registers. */ \
1143 DEBUG_PRINT1 ("\n"); \
1145 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
1148 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
1149 DEBUG_STATEMENT (num_regs_pushed++); \
1151 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1152 PUSH_FAILURE_POINTER (regstart[this_reg]); \
1154 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1155 PUSH_FAILURE_POINTER (regend[this_reg]); \
1157 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
1158 DEBUG_PRINT2 (" match_null=%d", \
1159 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1160 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1161 DEBUG_PRINT2 (" matched_something=%d", \
1162 MATCHED_SOMETHING (reg_info[this_reg])); \
1163 DEBUG_PRINT2 (" ever_matched=%d", \
1164 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1165 DEBUG_PRINT1 ("\n"); \
1166 PUSH_FAILURE_ELT (reg_info[this_reg].word); \
1169 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
1170 PUSH_FAILURE_INT (lowest_active_reg); \
1172 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
1173 PUSH_FAILURE_INT (highest_active_reg); \
1175 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
1176 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1177 PUSH_FAILURE_POINTER (pattern_place); \
1179 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
1180 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1182 DEBUG_PRINT1 ("'\n"); \
1183 PUSH_FAILURE_POINTER (string_place); \
1185 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1186 DEBUG_PUSH (failure_id); \
1189 /* This is the number of items that are pushed and popped on the stack
1190 for each register. */
1191 #define NUM_REG_ITEMS 3
1193 /* Individual items aside from the registers. */
1195 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1197 #define NUM_NONREG_ITEMS 4
1200 /* We push at most this many items on the stack. */
1201 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1203 /* We actually push this many items. */
1204 #define NUM_FAILURE_ITEMS \
1205 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
1208 /* How many items can still be added to the stack without overflowing it. */
1209 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1212 /* Pops what PUSH_FAIL_STACK pushes.
1214 We restore into the parameters, all of which should be lvalues:
1215 STR -- the saved data position.
1216 PAT -- the saved pattern position.
1217 LOW_REG, HIGH_REG -- the highest and lowest active registers.
1218 REGSTART, REGEND -- arrays of string positions.
1219 REG_INFO -- array of information about each subexpression.
1221 Also assumes the variables `fail_stack' and (if debugging), `bufp',
1222 `pend', `string1', `size1', `string2', and `size2'. */
1224 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1226 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
1228 const unsigned char *string_temp; \
1230 assert (!FAIL_STACK_EMPTY ()); \
1232 /* Remove failure points and point to how many regs pushed. */ \
1233 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1234 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1235 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1237 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1239 DEBUG_POP (&failure_id); \
1240 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1242 /* If the saved string location is NULL, it came from an \
1243 on_failure_keep_string_jump opcode, and we want to throw away the \
1244 saved NULL, thus retaining our current position in the string. */ \
1245 string_temp = POP_FAILURE_POINTER (); \
1246 if (string_temp != NULL) \
1247 str = (const char *) string_temp; \
1249 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
1250 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1251 DEBUG_PRINT1 ("'\n"); \
1253 pat = (unsigned char *) POP_FAILURE_POINTER (); \
1254 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
1255 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1257 /* Restore register info. */ \
1258 high_reg = (unsigned) POP_FAILURE_INT (); \
1259 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
1261 low_reg = (unsigned) POP_FAILURE_INT (); \
1262 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
1264 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
1266 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
1268 reg_info[this_reg].word = POP_FAILURE_ELT (); \
1269 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
1271 regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1272 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1274 regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1275 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1278 set_regs_matched_done = 0; \
1279 DEBUG_STATEMENT (nfailure_points_popped++); \
1280 } /* POP_FAILURE_POINT */
1284 /* Structure for per-register (a.k.a. per-group) information.
1285 Other register information, such as the
1286 starting and ending positions (which are addresses), and the list of
1287 inner groups (which is a bits list) are maintained in separate
1290 We are making a (strictly speaking) nonportable assumption here: that
1291 the compiler will pack our bit fields into something that fits into
1292 the type of `word', i.e., is something that fits into one item on the
1297 fail_stack_elt_t word;
1300 /* This field is one if this group can match the empty string,
1301 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1302 #define MATCH_NULL_UNSET_VALUE 3
1303 unsigned match_null_string_p : 2;
1304 unsigned is_active : 1;
1305 unsigned matched_something : 1;
1306 unsigned ever_matched_something : 1;
1308 } register_info_type;
1310 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1311 #define IS_ACTIVE(R) ((R).bits.is_active)
1312 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1313 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1316 /* Call this when have matched a real character; it sets `matched' flags
1317 for the subexpressions which we are currently inside. Also records
1318 that those subexprs have matched. */
1319 #define SET_REGS_MATCHED() \
1322 if (!set_regs_matched_done) \
1325 set_regs_matched_done = 1; \
1326 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1328 MATCHED_SOMETHING (reg_info[r]) \
1329 = EVER_MATCHED_SOMETHING (reg_info[r]) \
1336 /* Registers are set to a sentinel when they haven't yet matched. */
1337 static char reg_unset_dummy;
1338 #define REG_UNSET_VALUE (®_unset_dummy)
1339 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1341 /* Subroutine declarations and macros for regex_compile. */
1343 static void store_op1 (), store_op2 ();
1344 static void insert_op1 (), insert_op2 ();
1345 static boolean at_begline_loc_p (), at_endline_loc_p ();
1346 static boolean group_in_compile_stack ();
1347 static reg_errcode_t compile_range ();
1349 /* Fetch the next character in the uncompiled pattern---translating it
1350 if necessary. Also cast from a signed character in the constant
1351 string passed to us by the user to an unsigned char that we can use
1352 as an array index (in, e.g., `translate'). */
1353 #define PATFETCH(c) \
1354 do {if (p == pend) return REG_EEND; \
1355 c = (unsigned char) *p++; \
1356 if (translate) c = translate[c]; \
1359 /* Fetch the next character in the uncompiled pattern, with no
1361 #define PATFETCH_RAW(c) \
1362 do {if (p == pend) return REG_EEND; \
1363 c = (unsigned char) *p++; \
1366 /* Go backwards one character in the pattern. */
1367 #define PATUNFETCH p--
1370 /* If `translate' is non-null, return translate[D], else just D. We
1371 cast the subscript to translate because some data is declared as
1372 `char *', to avoid warnings when a string constant is passed. But
1373 when we use a character as a subscript we must make it unsigned. */
1374 #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
1377 /* Macros for outputting the compiled pattern into `buffer'. */
1379 /* If the buffer isn't allocated when it comes in, use this. */
1380 #define INIT_BUF_SIZE 32
1382 /* Make sure we have at least N more bytes of space in buffer. */
1383 #define GET_BUFFER_SPACE(n) \
1384 while (b - bufp->buffer + (n) > bufp->allocated) \
1387 /* Make sure we have one more byte of buffer space and then add C to it. */
1388 #define BUF_PUSH(c) \
1390 GET_BUFFER_SPACE (1); \
1391 *b++ = (unsigned char) (c); \
1395 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1396 #define BUF_PUSH_2(c1, c2) \
1398 GET_BUFFER_SPACE (2); \
1399 *b++ = (unsigned char) (c1); \
1400 *b++ = (unsigned char) (c2); \
1404 /* As with BUF_PUSH_2, except for three bytes. */
1405 #define BUF_PUSH_3(c1, c2, c3) \
1407 GET_BUFFER_SPACE (3); \
1408 *b++ = (unsigned char) (c1); \
1409 *b++ = (unsigned char) (c2); \
1410 *b++ = (unsigned char) (c3); \
1414 /* Store a jump with opcode OP at LOC to location TO. We store a
1415 relative address offset by the three bytes the jump itself occupies. */
1416 #define STORE_JUMP(op, loc, to) \
1417 store_op1 (op, loc, (to) - (loc) - 3)
1419 /* Likewise, for a two-argument jump. */
1420 #define STORE_JUMP2(op, loc, to, arg) \
1421 store_op2 (op, loc, (to) - (loc) - 3, arg)
1423 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1424 #define INSERT_JUMP(op, loc, to) \
1425 insert_op1 (op, loc, (to) - (loc) - 3, b)
1427 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1428 #define INSERT_JUMP2(op, loc, to, arg) \
1429 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
1432 /* This is not an arbitrary limit: the arguments which represent offsets
1433 into the pattern are two bytes long. So if 2^16 bytes turns out to
1434 be too small, many things would have to change. */
1435 #define MAX_BUF_SIZE (1L << 16)
1438 /* Extend the buffer by twice its current size via realloc and
1439 reset the pointers that pointed into the old block to point to the
1440 correct places in the new one. If extending the buffer results in it
1441 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1442 #define EXTEND_BUFFER() \
1444 unsigned char *old_buffer = bufp->buffer; \
1445 if (bufp->allocated == MAX_BUF_SIZE) \
1447 bufp->allocated <<= 1; \
1448 if (bufp->allocated > MAX_BUF_SIZE) \
1449 bufp->allocated = MAX_BUF_SIZE; \
1450 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
1451 if (bufp->buffer == NULL) \
1452 return REG_ESPACE; \
1453 /* If the buffer moved, move all the pointers into it. */ \
1454 if (old_buffer != bufp->buffer) \
1456 b = (b - old_buffer) + bufp->buffer; \
1457 begalt = (begalt - old_buffer) + bufp->buffer; \
1458 if (fixup_alt_jump) \
1459 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1461 laststart = (laststart - old_buffer) + bufp->buffer; \
1462 if (pending_exact) \
1463 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1468 /* Since we have one byte reserved for the register number argument to
1469 {start,stop}_memory, the maximum number of groups we can report
1470 things about is what fits in that byte. */
1471 #define MAX_REGNUM 255
1473 /* But patterns can have more than `MAX_REGNUM' registers. We just
1474 ignore the excess. */
1475 typedef unsigned regnum_t;
1478 /* Macros for the compile stack. */
1480 /* Since offsets can go either forwards or backwards, this type needs to
1481 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1482 typedef int pattern_offset_t;
1486 pattern_offset_t begalt_offset;
1487 pattern_offset_t fixup_alt_jump;
1488 pattern_offset_t inner_group_offset;
1489 pattern_offset_t laststart_offset;
1491 } compile_stack_elt_t;
1496 compile_stack_elt_t *stack;
1498 unsigned avail; /* Offset of next open position. */
1499 } compile_stack_type;
1502 #define INIT_COMPILE_STACK_SIZE 32
1504 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1505 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1507 /* The next available element. */
1508 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1511 /* Set the bit for character C in a list. */
1512 #define SET_LIST_BIT(c) \
1513 (b[((unsigned char) (c)) / BYTEWIDTH] \
1514 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1517 /* Get the next unsigned number in the uncompiled pattern. */
1518 #define GET_UNSIGNED_NUMBER(num) \
1522 while (ISDIGIT (c)) \
1526 num = num * 10 + c - '0'; \
1534 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1536 #define IS_CHAR_CLASS(string) \
1537 (STREQ (string, "alpha") || STREQ (string, "upper") \
1538 || STREQ (string, "lower") || STREQ (string, "digit") \
1539 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1540 || STREQ (string, "space") || STREQ (string, "print") \
1541 || STREQ (string, "punct") || STREQ (string, "graph") \
1542 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1544 #ifndef MATCH_MAY_ALLOCATE
1546 /* If we cannot allocate large objects within re_match_2_internal,
1547 we make the fail stack and register vectors global.
1548 The fail stack, we grow to the maximum size when a regexp
1550 The register vectors, we adjust in size each time we
1551 compile a regexp, according to the number of registers it needs. */
1553 static fail_stack_type fail_stack;
1555 /* Size with which the following vectors are currently allocated.
1556 That is so we can make them bigger as needed,
1557 but never make them smaller. */
1558 static int regs_allocated_size;
1560 static const char ** regstart, ** regend;
1561 static const char ** old_regstart, ** old_regend;
1562 static const char **best_regstart, **best_regend;
1563 static register_info_type *reg_info;
1564 static const char **reg_dummy;
1565 static register_info_type *reg_info_dummy;
1567 /* Make the register vectors big enough for NUM_REGS registers,
1568 but don't make them smaller. */
1571 regex_grow_registers (num_regs)
1574 if (num_regs > regs_allocated_size)
1576 RETALLOC_IF (regstart, num_regs, const char *);
1577 RETALLOC_IF (regend, num_regs, const char *);
1578 RETALLOC_IF (old_regstart, num_regs, const char *);
1579 RETALLOC_IF (old_regend, num_regs, const char *);
1580 RETALLOC_IF (best_regstart, num_regs, const char *);
1581 RETALLOC_IF (best_regend, num_regs, const char *);
1582 RETALLOC_IF (reg_info, num_regs, register_info_type);
1583 RETALLOC_IF (reg_dummy, num_regs, const char *);
1584 RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
1586 regs_allocated_size = num_regs;
1590 #endif /* not MATCH_MAY_ALLOCATE */
1592 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1593 Returns one of error codes defined in `regex.h', or zero for success.
1595 Assumes the `allocated' (and perhaps `buffer') and `translate'
1596 fields are set in BUFP on entry.
1598 If it succeeds, results are put in BUFP (if it returns an error, the
1599 contents of BUFP are undefined):
1600 `buffer' is the compiled pattern;
1601 `syntax' is set to SYNTAX;
1602 `used' is set to the length of the compiled pattern;
1603 `fastmap_accurate' is zero;
1604 `re_nsub' is the number of subexpressions in PATTERN;
1605 `not_bol' and `not_eol' are zero;
1607 The `fastmap' and `newline_anchor' fields are neither
1608 examined nor set. */
1610 /* Return, freeing storage we allocated. */
1611 #define FREE_STACK_RETURN(value) \
1612 return (free (compile_stack.stack), value)
1614 static reg_errcode_t
1615 regex_compile (pattern, size, syntax, bufp)
1616 const char *pattern;
1618 reg_syntax_t syntax;
1619 struct re_pattern_buffer *bufp;
1621 /* We fetch characters from PATTERN here. Even though PATTERN is
1622 `char *' (i.e., signed), we declare these variables as unsigned, so
1623 they can be reliably used as array indices. */
1624 register unsigned char c, c1;
1626 /* A random temporary spot in PATTERN. */
1629 /* Points to the end of the buffer, where we should append. */
1630 register unsigned char *b;
1632 /* Keeps track of unclosed groups. */
1633 compile_stack_type compile_stack;
1635 /* Points to the current (ending) position in the pattern. */
1636 const char *p = pattern;
1637 const char *pend = pattern + size;
1639 /* How to translate the characters in the pattern. */
1640 char *translate = bufp->translate;
1642 /* Address of the count-byte of the most recently inserted `exactn'
1643 command. This makes it possible to tell if a new exact-match
1644 character can be added to that command or if the character requires
1645 a new `exactn' command. */
1646 unsigned char *pending_exact = 0;
1648 /* Address of start of the most recently finished expression.
1649 This tells, e.g., postfix * where to find the start of its
1650 operand. Reset at the beginning of groups and alternatives. */
1651 unsigned char *laststart = 0;
1653 /* Address of beginning of regexp, or inside of last group. */
1654 unsigned char *begalt;
1656 /* Place in the uncompiled pattern (i.e., the {) to
1657 which to go back if the interval is invalid. */
1658 const char *beg_interval;
1660 /* Address of the place where a forward jump should go to the end of
1661 the containing expression. Each alternative of an `or' -- except the
1662 last -- ends with a forward jump of this sort. */
1663 unsigned char *fixup_alt_jump = 0;
1665 /* Counts open-groups as they are encountered. Remembered for the
1666 matching close-group on the compile stack, so the same register
1667 number is put in the stop_memory as the start_memory. */
1668 regnum_t regnum = 0;
1671 DEBUG_PRINT1 ("\nCompiling pattern: ");
1674 unsigned debug_count;
1676 for (debug_count = 0; debug_count < size; debug_count++)
1677 putchar (pattern[debug_count]);
1682 /* Initialize the compile stack. */
1683 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1684 if (compile_stack.stack == NULL)
1687 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1688 compile_stack.avail = 0;
1690 /* Initialize the pattern buffer. */
1691 bufp->syntax = syntax;
1692 bufp->fastmap_accurate = 0;
1693 bufp->not_bol = bufp->not_eol = 0;
1695 /* Set `used' to zero, so that if we return an error, the pattern
1696 printer (for debugging) will think there's no pattern. We reset it
1700 /* Always count groups, whether or not bufp->no_sub is set. */
1703 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1704 /* Initialize the syntax table. */
1705 init_syntax_once ();
1708 if (bufp->allocated == 0)
1711 { /* If zero allocated, but buffer is non-null, try to realloc
1712 enough space. This loses if buffer's address is bogus, but
1713 that is the user's responsibility. */
1714 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1717 { /* Caller did not allocate a buffer. Do it for them. */
1718 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1720 if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
1722 bufp->allocated = INIT_BUF_SIZE;
1725 begalt = b = bufp->buffer;
1727 /* Loop through the uncompiled pattern until we're at the end. */
1736 if ( /* If at start of pattern, it's an operator. */
1738 /* If context independent, it's an operator. */
1739 || syntax & RE_CONTEXT_INDEP_ANCHORS
1740 /* Otherwise, depends on what's come before. */
1741 || at_begline_loc_p (pattern, p, syntax))
1751 if ( /* If at end of pattern, it's an operator. */
1753 /* If context independent, it's an operator. */
1754 || syntax & RE_CONTEXT_INDEP_ANCHORS
1755 /* Otherwise, depends on what's next. */
1756 || at_endline_loc_p (p, pend, syntax))
1766 if ((syntax & RE_BK_PLUS_QM)
1767 || (syntax & RE_LIMITED_OPS))
1771 /* If there is no previous pattern... */
1774 if (syntax & RE_CONTEXT_INVALID_OPS)
1775 FREE_STACK_RETURN (REG_BADRPT);
1776 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1781 /* Are we optimizing this jump? */
1782 boolean keep_string_p = false;
1784 /* 1 means zero (many) matches is allowed. */
1785 char zero_times_ok = 0, many_times_ok = 0;
1787 /* If there is a sequence of repetition chars, collapse it
1788 down to just one (the right one). We can't combine
1789 interval operators with these because of, e.g., `a{2}*',
1790 which should only match an even number of `a's. */
1794 zero_times_ok |= c != '+';
1795 many_times_ok |= c != '?';
1803 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1806 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1808 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1811 if (!(c1 == '+' || c1 == '?'))
1826 /* If we get here, we found another repeat character. */
1829 /* Star, etc. applied to an empty pattern is equivalent
1830 to an empty pattern. */
1834 /* Now we know whether or not zero matches is allowed
1835 and also whether or not two or more matches is allowed. */
1837 { /* More than one repetition is allowed, so put in at the
1838 end a backward relative jump from `b' to before the next
1839 jump we're going to put in below (which jumps from
1840 laststart to after this jump).
1842 But if we are at the `*' in the exact sequence `.*\n',
1843 insert an unconditional jump backwards to the .,
1844 instead of the beginning of the loop. This way we only
1845 push a failure point once, instead of every time
1846 through the loop. */
1847 assert (p - 1 > pattern);
1849 /* Allocate the space for the jump. */
1850 GET_BUFFER_SPACE (3);
1852 /* We know we are not at the first character of the pattern,
1853 because laststart was nonzero. And we've already
1854 incremented `p', by the way, to be the character after
1855 the `*'. Do we have to do something analogous here
1856 for null bytes, because of RE_DOT_NOT_NULL? */
1857 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1859 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1860 && !(syntax & RE_DOT_NEWLINE))
1861 { /* We have .*\n. */
1862 STORE_JUMP (jump, b, laststart);
1863 keep_string_p = true;
1866 /* Anything else. */
1867 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1869 /* We've added more stuff to the buffer. */
1873 /* On failure, jump from laststart to b + 3, which will be the
1874 end of the buffer after this jump is inserted. */
1875 GET_BUFFER_SPACE (3);
1876 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1884 /* At least one repetition is required, so insert a
1885 `dummy_failure_jump' before the initial
1886 `on_failure_jump' instruction of the loop. This
1887 effects a skip over that instruction the first time
1888 we hit that loop. */
1889 GET_BUFFER_SPACE (3);
1890 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1905 boolean had_char_class = false;
1907 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
1909 /* Ensure that we have enough space to push a charset: the
1910 opcode, the length count, and the bitset; 34 bytes in all. */
1911 GET_BUFFER_SPACE (34);
1915 /* We test `*p == '^' twice, instead of using an if
1916 statement, so we only need one BUF_PUSH. */
1917 BUF_PUSH (*p == '^' ? charset_not : charset);
1921 /* Remember the first position in the bracket expression. */
1924 /* Push the number of bytes in the bitmap. */
1925 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1927 /* Clear the whole map. */
1928 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1930 /* charset_not matches newline according to a syntax bit. */
1931 if ((re_opcode_t) b[-2] == charset_not
1932 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1933 SET_LIST_BIT ('\n');
1935 /* Read in characters and ranges, setting map bits. */
1938 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
1942 /* \ might escape characters inside [...] and [^...]. */
1943 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1945 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1952 /* Could be the end of the bracket expression. If it's
1953 not (i.e., when the bracket expression is `[]' so
1954 far), the ']' character bit gets set way below. */
1955 if (c == ']' && p != p1 + 1)
1958 /* Look ahead to see if it's a range when the last thing
1959 was a character class. */
1960 if (had_char_class && c == '-' && *p != ']')
1961 FREE_STACK_RETURN (REG_ERANGE);
1963 /* Look ahead to see if it's a range when the last thing
1964 was a character: if this is a hyphen not at the
1965 beginning or the end of a list, then it's the range
1968 && !(p - 2 >= pattern && p[-2] == '[')
1969 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1973 = compile_range (&p, pend, translate, syntax, b);
1974 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
1977 else if (p[0] == '-' && p[1] != ']')
1978 { /* This handles ranges made up of characters only. */
1981 /* Move past the `-'. */
1984 ret = compile_range (&p, pend, translate, syntax, b);
1985 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
1988 /* See if we're at the beginning of a possible character
1991 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1992 { /* Leave room for the null. */
1993 char str[CHAR_CLASS_MAX_LENGTH + 1];
1998 /* If pattern is `[[:'. */
1999 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2004 if (c == ':' || c == ']' || p == pend
2005 || c1 == CHAR_CLASS_MAX_LENGTH)
2011 /* If isn't a word bracketed by `[:' and:`]':
2012 undo the ending character, the letters, and leave
2013 the leading `:' and `[' (but set bits for them). */
2014 if (c == ':' && *p == ']')
2017 boolean is_alnum = STREQ (str, "alnum");
2018 boolean is_alpha = STREQ (str, "alpha");
2019 boolean is_blank = STREQ (str, "blank");
2020 boolean is_cntrl = STREQ (str, "cntrl");
2021 boolean is_digit = STREQ (str, "digit");
2022 boolean is_graph = STREQ (str, "graph");
2023 boolean is_lower = STREQ (str, "lower");
2024 boolean is_print = STREQ (str, "print");
2025 boolean is_punct = STREQ (str, "punct");
2026 boolean is_space = STREQ (str, "space");
2027 boolean is_upper = STREQ (str, "upper");
2028 boolean is_xdigit = STREQ (str, "xdigit");
2030 if (!IS_CHAR_CLASS (str))
2031 FREE_STACK_RETURN (REG_ECTYPE);
2033 /* Throw away the ] at the end of the character
2037 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2039 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
2041 /* This was split into 3 if's to
2042 avoid an arbitrary limit in some compiler. */
2043 if ( (is_alnum && ISALNUM (ch))
2044 || (is_alpha && ISALPHA (ch))
2045 || (is_blank && ISBLANK (ch))
2046 || (is_cntrl && ISCNTRL (ch)))
2048 if ( (is_digit && ISDIGIT (ch))
2049 || (is_graph && ISGRAPH (ch))
2050 || (is_lower && ISLOWER (ch))
2051 || (is_print && ISPRINT (ch)))
2053 if ( (is_punct && ISPUNCT (ch))
2054 || (is_space && ISSPACE (ch))
2055 || (is_upper && ISUPPER (ch))
2056 || (is_xdigit && ISXDIGIT (ch)))
2059 had_char_class = true;
2068 had_char_class = false;
2073 had_char_class = false;
2078 /* Discard any (non)matching list bytes that are all 0 at the
2079 end of the map. Decrease the map-length byte too. */
2080 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
2088 if (syntax & RE_NO_BK_PARENS)
2095 if (syntax & RE_NO_BK_PARENS)
2102 if (syntax & RE_NEWLINE_ALT)
2109 if (syntax & RE_NO_BK_VBAR)
2116 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
2117 goto handle_interval;
2123 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2125 /* Do not translate the character after the \, so that we can
2126 distinguish, e.g., \B from \b, even if we normally would
2127 translate, e.g., B to b. */
2133 if (syntax & RE_NO_BK_PARENS)
2134 goto normal_backslash;
2140 if (COMPILE_STACK_FULL)
2142 RETALLOC (compile_stack.stack, compile_stack.size << 1,
2143 compile_stack_elt_t);
2144 if (compile_stack.stack == NULL) return REG_ESPACE;
2146 compile_stack.size <<= 1;
2149 /* These are the values to restore when we hit end of this
2150 group. They are all relative offsets, so that if the
2151 whole pattern moves because of realloc, they will still
2153 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2154 COMPILE_STACK_TOP.fixup_alt_jump
2155 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2156 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2157 COMPILE_STACK_TOP.regnum = regnum;
2159 /* We will eventually replace the 0 with the number of
2160 groups inner to this one. But do not push a
2161 start_memory for groups beyond the last one we can
2162 represent in the compiled pattern. */
2163 if (regnum <= MAX_REGNUM)
2165 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2166 BUF_PUSH_3 (start_memory, regnum, 0);
2169 compile_stack.avail++;
2174 /* If we've reached MAX_REGNUM groups, then this open
2175 won't actually generate any code, so we'll have to
2176 clear pending_exact explicitly. */
2182 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
2184 if (COMPILE_STACK_EMPTY)
2185 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2186 goto normal_backslash;
2188 FREE_STACK_RETURN (REG_ERPAREN);
2192 { /* Push a dummy failure point at the end of the
2193 alternative for a possible future
2194 `pop_failure_jump' to pop. See comments at
2195 `push_dummy_failure' in `re_match_2'. */
2196 BUF_PUSH (push_dummy_failure);
2198 /* We allocated space for this jump when we assigned
2199 to `fixup_alt_jump', in the `handle_alt' case below. */
2200 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2203 /* See similar code for backslashed left paren above. */
2204 if (COMPILE_STACK_EMPTY)
2205 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2208 FREE_STACK_RETURN (REG_ERPAREN);
2210 /* Since we just checked for an empty stack above, this
2211 ``can't happen''. */
2212 assert (compile_stack.avail != 0);
2214 /* We don't just want to restore into `regnum', because
2215 later groups should continue to be numbered higher,
2216 as in `(ab)c(de)' -- the second group is #2. */
2217 regnum_t this_group_regnum;
2219 compile_stack.avail--;
2220 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2222 = COMPILE_STACK_TOP.fixup_alt_jump
2223 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
2225 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2226 this_group_regnum = COMPILE_STACK_TOP.regnum;
2227 /* If we've reached MAX_REGNUM groups, then this open
2228 won't actually generate any code, so we'll have to
2229 clear pending_exact explicitly. */
2232 /* We're at the end of the group, so now we know how many
2233 groups were inside this one. */
2234 if (this_group_regnum <= MAX_REGNUM)
2236 unsigned char *inner_group_loc
2237 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2239 *inner_group_loc = regnum - this_group_regnum;
2240 BUF_PUSH_3 (stop_memory, this_group_regnum,
2241 regnum - this_group_regnum);
2247 case '|': /* `\|'. */
2248 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
2249 goto normal_backslash;
2251 if (syntax & RE_LIMITED_OPS)
2254 /* Insert before the previous alternative a jump which
2255 jumps to this alternative if the former fails. */
2256 GET_BUFFER_SPACE (3);
2257 INSERT_JUMP (on_failure_jump, begalt, b + 6);
2261 /* The alternative before this one has a jump after it
2262 which gets executed if it gets matched. Adjust that
2263 jump so it will jump to this alternative's analogous
2264 jump (put in below, which in turn will jump to the next
2265 (if any) alternative's such jump, etc.). The last such
2266 jump jumps to the correct final destination. A picture:
2272 If we are at `b', then fixup_alt_jump right now points to a
2273 three-byte space after `a'. We'll put in the jump, set
2274 fixup_alt_jump to right after `b', and leave behind three
2275 bytes which we'll fill in when we get to after `c'. */
2278 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2280 /* Mark and leave space for a jump after this alternative,
2281 to be filled in later either by next alternative or
2282 when know we're at the end of a series of alternatives. */
2284 GET_BUFFER_SPACE (3);
2293 /* If \{ is a literal. */
2294 if (!(syntax & RE_INTERVALS)
2295 /* If we're at `\{' and it's not the open-interval
2297 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2298 || (p - 2 == pattern && p == pend))
2299 goto normal_backslash;
2303 /* If got here, then the syntax allows intervals. */
2305 /* At least (most) this many matches must be made. */
2306 int lower_bound = -1, upper_bound = -1;
2308 beg_interval = p - 1;
2312 if (syntax & RE_NO_BK_BRACES)
2313 goto unfetch_interval;
2315 FREE_STACK_RETURN (REG_EBRACE);
2318 GET_UNSIGNED_NUMBER (lower_bound);
2322 GET_UNSIGNED_NUMBER (upper_bound);
2323 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
2326 /* Interval such as `{1}' => match exactly once. */
2327 upper_bound = lower_bound;
2329 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
2330 || lower_bound > upper_bound)
2332 if (syntax & RE_NO_BK_BRACES)
2333 goto unfetch_interval;
2335 FREE_STACK_RETURN (REG_BADBR);
2338 if (!(syntax & RE_NO_BK_BRACES))
2340 if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
2347 if (syntax & RE_NO_BK_BRACES)
2348 goto unfetch_interval;
2350 FREE_STACK_RETURN (REG_BADBR);
2353 /* We just parsed a valid interval. */
2355 /* If it's invalid to have no preceding re. */
2358 if (syntax & RE_CONTEXT_INVALID_OPS)
2359 FREE_STACK_RETURN (REG_BADRPT);
2360 else if (syntax & RE_CONTEXT_INDEP_OPS)
2363 goto unfetch_interval;
2366 /* If the upper bound is zero, don't want to succeed at
2367 all; jump from `laststart' to `b + 3', which will be
2368 the end of the buffer after we insert the jump. */
2369 if (upper_bound == 0)
2371 GET_BUFFER_SPACE (3);
2372 INSERT_JUMP (jump, laststart, b + 3);
2376 /* Otherwise, we have a nontrivial interval. When
2377 we're all done, the pattern will look like:
2378 set_number_at <jump count> <upper bound>
2379 set_number_at <succeed_n count> <lower bound>
2380 succeed_n <after jump addr> <succeed_n count>
2382 jump_n <succeed_n addr> <jump count>
2383 (The upper bound and `jump_n' are omitted if
2384 `upper_bound' is 1, though.) */
2386 { /* If the upper bound is > 1, we need to insert
2387 more at the end of the loop. */
2388 unsigned nbytes = 10 + (upper_bound > 1) * 10;
2390 GET_BUFFER_SPACE (nbytes);
2392 /* Initialize lower bound of the `succeed_n', even
2393 though it will be set during matching by its
2394 attendant `set_number_at' (inserted next),
2395 because `re_compile_fastmap' needs to know.
2396 Jump to the `jump_n' we might insert below. */
2397 INSERT_JUMP2 (succeed_n, laststart,
2398 b + 5 + (upper_bound > 1) * 5,
2402 /* Code to initialize the lower bound. Insert
2403 before the `succeed_n'. The `5' is the last two
2404 bytes of this `set_number_at', plus 3 bytes of
2405 the following `succeed_n'. */
2406 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2409 if (upper_bound > 1)
2410 { /* More than one repetition is allowed, so
2411 append a backward jump to the `succeed_n'
2412 that starts this interval.
2414 When we've reached this during matching,
2415 we'll have matched the interval once, so
2416 jump back only `upper_bound - 1' times. */
2417 STORE_JUMP2 (jump_n, b, laststart + 5,
2421 /* The location we want to set is the second
2422 parameter of the `jump_n'; that is `b-2' as
2423 an absolute address. `laststart' will be
2424 the `set_number_at' we're about to insert;
2425 `laststart+3' the number to set, the source
2426 for the relative address. But we are
2427 inserting into the middle of the pattern --
2428 so everything is getting moved up by 5.
2429 Conclusion: (b - 2) - (laststart + 3) + 5,
2430 i.e., b - laststart.
2432 We insert this at the beginning of the loop
2433 so that if we fail during matching, we'll
2434 reinitialize the bounds. */
2435 insert_op2 (set_number_at, laststart, b - laststart,
2436 upper_bound - 1, b);
2441 beg_interval = NULL;
2446 /* If an invalid interval, match the characters as literals. */
2447 assert (beg_interval);
2449 beg_interval = NULL;
2451 /* normal_char and normal_backslash need `c'. */
2454 if (!(syntax & RE_NO_BK_BRACES))
2456 if (p > pattern && p[-1] == '\\')
2457 goto normal_backslash;
2462 /* There is no way to specify the before_dot and after_dot
2463 operators. rms says this is ok. --karl */
2471 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2477 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2484 BUF_PUSH (wordchar);
2490 BUF_PUSH (notwordchar);
2503 BUF_PUSH (wordbound);
2507 BUF_PUSH (notwordbound);
2518 case '1': case '2': case '3': case '4': case '5':
2519 case '6': case '7': case '8': case '9':
2520 if (syntax & RE_NO_BK_REFS)
2526 FREE_STACK_RETURN (REG_ESUBREG);
2528 /* Can't back reference to a subexpression if inside of it. */
2529 if (group_in_compile_stack (compile_stack, c1))
2533 BUF_PUSH_2 (duplicate, c1);
2539 if (syntax & RE_BK_PLUS_QM)
2542 goto normal_backslash;
2546 /* You might think it would be useful for \ to mean
2547 not to translate; but if we don't translate it
2548 it will never match anything. */
2556 /* Expects the character in `c'. */
2558 /* If no exactn currently being built. */
2561 /* If last exactn not at current position. */
2562 || pending_exact + *pending_exact + 1 != b
2564 /* We have only one byte following the exactn for the count. */
2565 || *pending_exact == (1 << BYTEWIDTH) - 1
2567 /* If followed by a repetition operator. */
2568 || *p == '*' || *p == '^'
2569 || ((syntax & RE_BK_PLUS_QM)
2570 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2571 : (*p == '+' || *p == '?'))
2572 || ((syntax & RE_INTERVALS)
2573 && ((syntax & RE_NO_BK_BRACES)
2575 : (p[0] == '\\' && p[1] == '{'))))
2577 /* Start building a new exactn. */
2581 BUF_PUSH_2 (exactn, 0);
2582 pending_exact = b - 1;
2589 } /* while p != pend */
2592 /* Through the pattern now. */
2595 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2597 if (!COMPILE_STACK_EMPTY)
2598 FREE_STACK_RETURN (REG_EPAREN);
2600 /* If we don't want backtracking, force success
2601 the first time we reach the end of the compiled pattern. */
2602 if (syntax & RE_NO_POSIX_BACKTRACKING)
2605 free (compile_stack.stack);
2607 /* We have succeeded; set the length of the buffer. */
2608 bufp->used = b - bufp->buffer;
2613 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2614 print_compiled_pattern (bufp);
2618 #ifndef MATCH_MAY_ALLOCATE
2619 /* Initialize the failure stack to the largest possible stack. This
2620 isn't necessary unless we're trying to avoid calling alloca in
2621 the search and match routines. */
2623 int num_regs = bufp->re_nsub + 1;
2625 /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2626 is strictly greater than re_max_failures, the largest possible stack
2627 is 2 * re_max_failures failure points. */
2628 if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
2630 fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2633 if (! fail_stack.stack)
2635 = (fail_stack_elt_t *) xmalloc (fail_stack.size
2636 * sizeof (fail_stack_elt_t));
2639 = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
2641 * sizeof (fail_stack_elt_t)));
2642 #else /* not emacs */
2643 if (! fail_stack.stack)
2645 = (fail_stack_elt_t *) malloc (fail_stack.size
2646 * sizeof (fail_stack_elt_t));
2649 = (fail_stack_elt_t *) realloc (fail_stack.stack,
2651 * sizeof (fail_stack_elt_t)));
2652 #endif /* not emacs */
2655 regex_grow_registers (num_regs);
2657 #endif /* not MATCH_MAY_ALLOCATE */
2660 } /* regex_compile */
2662 /* Subroutines for `regex_compile'. */
2664 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2667 store_op1 (op, loc, arg)
2672 *loc = (unsigned char) op;
2673 STORE_NUMBER (loc + 1, arg);
2677 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2680 store_op2 (op, loc, arg1, arg2)
2685 *loc = (unsigned char) op;
2686 STORE_NUMBER (loc + 1, arg1);
2687 STORE_NUMBER (loc + 3, arg2);
2691 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2692 for OP followed by two-byte integer parameter ARG. */
2695 insert_op1 (op, loc, arg, end)
2701 register unsigned char *pfrom = end;
2702 register unsigned char *pto = end + 3;
2704 while (pfrom != loc)
2707 store_op1 (op, loc, arg);
2711 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2714 insert_op2 (op, loc, arg1, arg2, end)
2720 register unsigned char *pfrom = end;
2721 register unsigned char *pto = end + 5;
2723 while (pfrom != loc)
2726 store_op2 (op, loc, arg1, arg2);
2730 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2731 after an alternative or a begin-subexpression. We assume there is at
2732 least one character before the ^. */
2735 at_begline_loc_p (pattern, p, syntax)
2736 const char *pattern, *p;
2737 reg_syntax_t syntax;
2739 const char *prev = p - 2;
2740 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2743 /* After a subexpression? */
2744 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2745 /* After an alternative? */
2746 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2750 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2751 at least one character after the $, i.e., `P < PEND'. */
2754 at_endline_loc_p (p, pend, syntax)
2755 const char *p, *pend;
2758 const char *next = p;
2759 boolean next_backslash = *next == '\\';
2760 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2763 /* Before a subexpression? */
2764 (syntax & RE_NO_BK_PARENS ? *next == ')'
2765 : next_backslash && next_next && *next_next == ')')
2766 /* Before an alternative? */
2767 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2768 : next_backslash && next_next && *next_next == '|');
2772 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2773 false if it's not. */
2776 group_in_compile_stack (compile_stack, regnum)
2777 compile_stack_type compile_stack;
2782 for (this_element = compile_stack.avail - 1;
2785 if (compile_stack.stack[this_element].regnum == regnum)
2792 /* Read the ending character of a range (in a bracket expression) from the
2793 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2794 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2795 Then we set the translation of all bits between the starting and
2796 ending characters (inclusive) in the compiled pattern B.
2798 Return an error code.
2800 We use these short variable names so we can use the same macros as
2801 `regex_compile' itself. */
2803 static reg_errcode_t
2804 compile_range (p_ptr, pend, translate, syntax, b)
2805 const char **p_ptr, *pend;
2807 reg_syntax_t syntax;
2812 const char *p = *p_ptr;
2813 int range_start, range_end;
2818 /* Even though the pattern is a signed `char *', we need to fetch
2819 with unsigned char *'s; if the high bit of the pattern character
2820 is set, the range endpoints will be negative if we fetch using a
2823 We also want to fetch the endpoints without translating them; the
2824 appropriate translation is done in the bit-setting loop below. */
2825 /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *. */
2826 range_start = ((const unsigned char *) p)[-2];
2827 range_end = ((const unsigned char *) p)[0];
2829 /* Have to increment the pointer into the pattern string, so the
2830 caller isn't still at the ending character. */
2833 /* If the start is after the end, the range is empty. */
2834 if (range_start > range_end)
2835 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2837 /* Here we see why `this_char' has to be larger than an `unsigned
2838 char' -- the range is inclusive, so if `range_end' == 0xff
2839 (assuming 8-bit characters), we would otherwise go into an infinite
2840 loop, since all characters <= 0xff. */
2841 for (this_char = range_start; this_char <= range_end; this_char++)
2843 SET_LIST_BIT (TRANSLATE (this_char));
2849 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2850 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2851 characters can start a string that matches the pattern. This fastmap
2852 is used by re_search to skip quickly over impossible starting points.
2854 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2855 area as BUFP->fastmap.
2857 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2860 Returns 0 if we succeed, -2 if an internal error. */
2863 re_compile_fastmap (bufp)
2864 struct re_pattern_buffer *bufp;
2867 #ifdef MATCH_MAY_ALLOCATE
2868 fail_stack_type fail_stack;
2870 #ifndef REGEX_MALLOC
2873 /* We don't push any register information onto the failure stack. */
2874 unsigned num_regs = 0;
2876 register char *fastmap = bufp->fastmap;
2877 unsigned char *pattern = bufp->buffer;
2878 unsigned long size = bufp->used;
2879 unsigned char *p = pattern;
2880 register unsigned char *pend = pattern + size;
2882 /* This holds the pointer to the failure stack, when
2883 it is allocated relocatably. */
2884 fail_stack_elt_t *failure_stack_ptr;
2886 /* Assume that each path through the pattern can be null until
2887 proven otherwise. We set this false at the bottom of switch
2888 statement, to which we get only if a particular path doesn't
2889 match the empty string. */
2890 boolean path_can_be_null = true;
2892 /* We aren't doing a `succeed_n' to begin with. */
2893 boolean succeed_n_p = false;
2895 assert (fastmap != NULL && p != NULL);
2898 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2899 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2900 bufp->can_be_null = 0;
2904 if (p == pend || *p == succeed)
2906 /* We have reached the (effective) end of pattern. */
2907 if (!FAIL_STACK_EMPTY ())
2909 bufp->can_be_null |= path_can_be_null;
2911 /* Reset for next path. */
2912 path_can_be_null = true;
2914 p = fail_stack.stack[--fail_stack.avail].pointer;
2922 /* We should never be about to go beyond the end of the pattern. */
2925 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
2928 /* I guess the idea here is to simply not bother with a fastmap
2929 if a backreference is used, since it's too hard to figure out
2930 the fastmap for the corresponding group. Setting
2931 `can_be_null' stops `re_search_2' from using the fastmap, so
2932 that is all we do. */
2934 bufp->can_be_null = 1;
2938 /* Following are the cases which match a character. These end
2947 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2948 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2954 /* Chars beyond end of map must be allowed. */
2955 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2958 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2959 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2965 for (j = 0; j < (1 << BYTEWIDTH); j++)
2966 if (SYNTAX (j) == Sword)
2972 for (j = 0; j < (1 << BYTEWIDTH); j++)
2973 if (SYNTAX (j) != Sword)
2980 int fastmap_newline = fastmap['\n'];
2982 /* `.' matches anything ... */
2983 for (j = 0; j < (1 << BYTEWIDTH); j++)
2986 /* ... except perhaps newline. */
2987 if (!(bufp->syntax & RE_DOT_NEWLINE))
2988 fastmap['\n'] = fastmap_newline;
2990 /* Return if we have already set `can_be_null'; if we have,
2991 then the fastmap is irrelevant. Something's wrong here. */
2992 else if (bufp->can_be_null)
2995 /* Otherwise, have to check alternative paths. */
3002 for (j = 0; j < (1 << BYTEWIDTH); j++)
3003 if (SYNTAX (j) == (enum syntaxcode) k)
3010 for (j = 0; j < (1 << BYTEWIDTH); j++)
3011 if (SYNTAX (j) != (enum syntaxcode) k)
3016 /* All cases after this match the empty string. These end with
3024 #endif /* not emacs */
3036 case push_dummy_failure:
3041 case pop_failure_jump:
3042 case maybe_pop_jump:
3045 case dummy_failure_jump:
3046 EXTRACT_NUMBER_AND_INCR (j, p);
3051 /* Jump backward implies we just went through the body of a
3052 loop and matched nothing. Opcode jumped to should be
3053 `on_failure_jump' or `succeed_n'. Just treat it like an
3054 ordinary jump. For a * loop, it has pushed its failure
3055 point already; if so, discard that as redundant. */
3056 if ((re_opcode_t) *p != on_failure_jump
3057 && (re_opcode_t) *p != succeed_n)
3061 EXTRACT_NUMBER_AND_INCR (j, p);
3064 /* If what's on the stack is where we are now, pop it. */
3065 if (!FAIL_STACK_EMPTY ()
3066 && fail_stack.stack[fail_stack.avail - 1].pointer == p)
3072 case on_failure_jump:
3073 case on_failure_keep_string_jump:
3074 handle_on_failure_jump:
3075 EXTRACT_NUMBER_AND_INCR (j, p);
3077 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
3078 end of the pattern. We don't want to push such a point,
3079 since when we restore it above, entering the switch will
3080 increment `p' past the end of the pattern. We don't need
3081 to push such a point since we obviously won't find any more
3082 fastmap entries beyond `pend'. Such a pattern can match
3083 the null string, though. */
3086 if (!PUSH_PATTERN_OP (p + j, fail_stack))
3088 RESET_FAIL_STACK ();
3093 bufp->can_be_null = 1;
3097 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
3098 succeed_n_p = false;
3105 /* Get to the number of times to succeed. */
3108 /* Increment p past the n for when k != 0. */
3109 EXTRACT_NUMBER_AND_INCR (k, p);
3113 succeed_n_p = true; /* Spaghetti code alert. */
3114 goto handle_on_failure_jump;
3131 abort (); /* We have listed all the cases. */
3134 /* Getting here means we have found the possible starting
3135 characters for one path of the pattern -- and that the empty
3136 string does not match. We need not follow this path further.
3137 Instead, look at the next alternative (remembered on the
3138 stack), or quit if no more. The test at the top of the loop
3139 does these things. */
3140 path_can_be_null = false;
3144 /* Set `can_be_null' for the last path (also the first path, if the
3145 pattern is empty). */
3146 bufp->can_be_null |= path_can_be_null;
3149 RESET_FAIL_STACK ();
3151 } /* re_compile_fastmap */
3153 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
3154 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
3155 this memory for recording register information. STARTS and ENDS
3156 must be allocated using the malloc library routine, and must each
3157 be at least NUM_REGS * sizeof (regoff_t) bytes long.
3159 If NUM_REGS == 0, then subsequent matches should allocate their own
3162 Unless this function is called, the first search or match using
3163 PATTERN_BUFFER will allocate its own register data, without
3164 freeing the old data. */
3167 re_set_registers (bufp, regs, num_regs, starts, ends)
3168 struct re_pattern_buffer *bufp;
3169 struct re_registers *regs;
3171 regoff_t *starts, *ends;
3175 bufp->regs_allocated = REGS_REALLOCATE;
3176 regs->num_regs = num_regs;
3177 regs->start = starts;
3182 bufp->regs_allocated = REGS_UNALLOCATED;
3184 regs->start = regs->end = (regoff_t *) 0;
3188 /* Searching routines. */
3190 /* Like re_search_2, below, but only one string is specified, and
3191 doesn't let you say where to stop matching. */
3194 re_search (bufp, string, size, startpos, range, regs)
3195 struct re_pattern_buffer *bufp;
3197 int size, startpos, range;
3198 struct re_registers *regs;
3200 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3205 /* Using the compiled pattern in BUFP->buffer, first tries to match the
3206 virtual concatenation of STRING1 and STRING2, starting first at index
3207 STARTPOS, then at STARTPOS + 1, and so on.
3209 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3211 RANGE is how far to scan while trying to match. RANGE = 0 means try
3212 only at STARTPOS; in general, the last start tried is STARTPOS +
3215 In REGS, return the indices of the virtual concatenation of STRING1
3216 and STRING2 that matched the entire BUFP->buffer and its contained
3219 Do not consider matching one past the index STOP in the virtual
3220 concatenation of STRING1 and STRING2.
3222 We return either the position in the strings at which the match was
3223 found, -1 if no match, or -2 if error (such as failure
3227 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3228 struct re_pattern_buffer *bufp;
3229 const char *string1, *string2;
3233 struct re_registers *regs;
3237 register char *fastmap = bufp->fastmap;
3238 register char *translate = bufp->translate;
3239 int total_size = size1 + size2;
3240 int endpos = startpos + range;
3242 /* Check for out-of-range STARTPOS. */
3243 if (startpos < 0 || startpos > total_size)
3246 /* Fix up RANGE if it might eventually take us outside
3247 the virtual concatenation of STRING1 and STRING2. */
3249 range = -1 - startpos;
3250 else if (endpos > total_size)
3251 range = total_size - startpos;
3253 /* If the search isn't to be a backwards one, don't waste time in a
3254 search for a pattern that must be anchored. */
3255 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3263 /* Update the fastmap now if not correct already. */
3264 if (fastmap && !bufp->fastmap_accurate)
3265 if (re_compile_fastmap (bufp) == -2)
3268 /* Loop through the string, looking for a place to start matching. */
3271 /* If a fastmap is supplied, skip quickly over characters that
3272 cannot be the start of a match. If the pattern can match the
3273 null string, however, we don't need to skip characters; we want
3274 the first null string. */
3275 if (fastmap && startpos < total_size && !bufp->can_be_null)
3277 if (range > 0) /* Searching forwards. */
3279 register const char *d;
3280 register int lim = 0;
3283 if (startpos < size1 && startpos + range >= size1)
3284 lim = range - (size1 - startpos);
3286 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3288 /* Written out as an if-else to avoid testing `translate'
3292 && !fastmap[(unsigned char)
3293 translate[(unsigned char) *d++]])
3296 while (range > lim && !fastmap[(unsigned char) *d++])
3299 startpos += irange - range;
3301 else /* Searching backwards. */
3303 register char c = (size1 == 0 || startpos >= size1
3304 ? string2[startpos - size1]
3305 : string1[startpos]);
3307 if (!fastmap[(unsigned char) TRANSLATE (c)])
3312 /* If can't match the null string, and that's all we have left, fail. */
3313 if (range >= 0 && startpos == total_size && fastmap
3314 && !bufp->can_be_null)
3317 val = re_match_2_internal (bufp, string1, size1, string2, size2,
3318 startpos, regs, stop);
3319 #ifndef REGEX_MALLOC
3348 /* Declarations and macros for re_match_2. */
3350 static int bcmp_translate ();
3351 static boolean alt_match_null_string_p (),
3352 common_op_match_null_string_p (),
3353 group_match_null_string_p ();
3355 /* This converts PTR, a pointer into one of the search strings `string1'
3356 and `string2' into an offset from the beginning of that string. */
3357 #define POINTER_TO_OFFSET(ptr) \
3358 (FIRST_STRING_P (ptr) \
3359 ? ((regoff_t) ((ptr) - string1)) \
3360 : ((regoff_t) ((ptr) - string2 + size1)))
3362 /* Macros for dealing with the split strings in re_match_2. */
3364 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3366 /* Call before fetching a character with *d. This switches over to
3367 string2 if necessary. */
3368 #define PREFETCH() \
3371 /* End of string2 => fail. */ \
3372 if (dend == end_match_2) \
3374 /* End of string1 => advance to string2. */ \
3376 dend = end_match_2; \
3380 /* Test if at very beginning or at very end of the virtual concatenation
3381 of `string1' and `string2'. If only one string, it's `string2'. */
3382 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3383 #define AT_STRINGS_END(d) ((d) == end2)
3386 /* Test if D points to a character which is word-constituent. We have
3387 two special cases to check for: if past the end of string1, look at
3388 the first character in string2; and if before the beginning of
3389 string2, look at the last character in string1. */
3390 #define WORDCHAR_P(d) \
3391 (SYNTAX ((d) == end1 ? *string2 \
3392 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3395 /* Test if the character before D and the one at D differ with respect
3396 to being word-constituent. */
3397 #define AT_WORD_BOUNDARY(d) \
3398 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3399 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3402 /* Free everything we malloc. */
3403 #ifdef MATCH_MAY_ALLOCATE
3404 #define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
3405 #define FREE_VARIABLES() \
3407 REGEX_FREE_STACK (fail_stack.stack); \
3408 FREE_VAR (regstart); \
3409 FREE_VAR (regend); \
3410 FREE_VAR (old_regstart); \
3411 FREE_VAR (old_regend); \
3412 FREE_VAR (best_regstart); \
3413 FREE_VAR (best_regend); \
3414 FREE_VAR (reg_info); \
3415 FREE_VAR (reg_dummy); \
3416 FREE_VAR (reg_info_dummy); \
3419 #define FREE_VARIABLES() /* Do nothing! */
3420 #endif /* not MATCH_MAY_ALLOCATE */
3422 /* These values must meet several constraints. They must not be valid
3423 register values; since we have a limit of 255 registers (because
3424 we use only one byte in the pattern for the register number), we can
3425 use numbers larger than 255. They must differ by 1, because of
3426 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3427 be larger than the value for the highest register, so we do not try
3428 to actually save any registers when none are active. */
3429 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3430 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3432 /* Matching routines. */
3434 #ifndef emacs /* Emacs never uses this. */
3435 /* re_match is like re_match_2 except it takes only a single string. */
3438 re_match (bufp, string, size, pos, regs)
3439 struct re_pattern_buffer *bufp;
3442 struct re_registers *regs;
3444 int result = re_match_2_internal (bufp, NULL, 0, string, size,
3449 #endif /* not emacs */
3452 /* re_match_2 matches the compiled pattern in BUFP against the
3453 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3454 and SIZE2, respectively). We start matching at POS, and stop
3457 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3458 store offsets for the substring each group matched in REGS. See the
3459 documentation for exactly how many groups we fill.
3461 We return -1 if no match, -2 if an internal error (such as the
3462 failure stack overflowing). Otherwise, we return the length of the
3463 matched substring. */
3466 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3467 struct re_pattern_buffer *bufp;
3468 const char *string1, *string2;
3471 struct re_registers *regs;
3474 int result = re_match_2_internal (bufp, string1, size1, string2, size2,
3480 /* This is a separate function so that we can force an alloca cleanup
3483 re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
3484 struct re_pattern_buffer *bufp;
3485 const char *string1, *string2;
3488 struct re_registers *regs;
3491 /* General temporaries. */
3495 /* Just past the end of the corresponding string. */
3496 const char *end1, *end2;
3498 /* Pointers into string1 and string2, just past the last characters in
3499 each to consider matching. */
3500 const char *end_match_1, *end_match_2;
3502 /* Where we are in the data, and the end of the current string. */
3503 const char *d, *dend;
3505 /* Where we are in the pattern, and the end of the pattern. */
3506 unsigned char *p = bufp->buffer;
3507 register unsigned char *pend = p + bufp->used;
3509 /* Mark the opcode just after a start_memory, so we can test for an
3510 empty subpattern when we get to the stop_memory. */
3511 unsigned char *just_past_start_mem = 0;
3513 /* We use this to map every character in the string. */
3514 char *translate = bufp->translate;
3516 /* Failure point stack. Each place that can handle a failure further
3517 down the line pushes a failure point on this stack. It consists of
3518 restart, regend, and reg_info for all registers corresponding to
3519 the subexpressions we're currently inside, plus the number of such
3520 registers, and, finally, two char *'s. The first char * is where
3521 to resume scanning the pattern; the second one is where to resume
3522 scanning the strings. If the latter is zero, the failure point is
3523 a ``dummy''; if a failure happens and the failure point is a dummy,
3524 it gets discarded and the next next one is tried. */
3525 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3526 fail_stack_type fail_stack;
3529 static unsigned failure_id = 0;
3530 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3533 /* This holds the pointer to the failure stack, when
3534 it is allocated relocatably. */
3535 fail_stack_elt_t *failure_stack_ptr;
3537 /* We fill all the registers internally, independent of what we
3538 return, for use in backreferences. The number here includes
3539 an element for register zero. */
3540 unsigned num_regs = bufp->re_nsub + 1;
3542 /* The currently active registers. */
3543 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3544 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3546 /* Information on the contents of registers. These are pointers into
3547 the input strings; they record just what was matched (on this
3548 attempt) by a subexpression part of the pattern, that is, the
3549 regnum-th regstart pointer points to where in the pattern we began
3550 matching and the regnum-th regend points to right after where we
3551 stopped matching the regnum-th subexpression. (The zeroth register
3552 keeps track of what the whole pattern matches.) */
3553 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3554 const char **regstart, **regend;
3557 /* If a group that's operated upon by a repetition operator fails to
3558 match anything, then the register for its start will need to be
3559 restored because it will have been set to wherever in the string we
3560 are when we last see its open-group operator. Similarly for a
3562 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3563 const char **old_regstart, **old_regend;
3566 /* The is_active field of reg_info helps us keep track of which (possibly
3567 nested) subexpressions we are currently in. The matched_something
3568 field of reg_info[reg_num] helps us tell whether or not we have
3569 matched any of the pattern so far this time through the reg_num-th
3570 subexpression. These two fields get reset each time through any
3571 loop their register is in. */
3572 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3573 register_info_type *reg_info;
3576 /* The following record the register info as found in the above
3577 variables when we find a match better than any we've seen before.
3578 This happens as we backtrack through the failure points, which in
3579 turn happens only if we have not yet matched the entire string. */
3580 unsigned best_regs_set = false;
3581 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3582 const char **best_regstart, **best_regend;
3585 /* Logically, this is `best_regend[0]'. But we don't want to have to
3586 allocate space for that if we're not allocating space for anything
3587 else (see below). Also, we never need info about register 0 for
3588 any of the other register vectors, and it seems rather a kludge to
3589 treat `best_regend' differently than the rest. So we keep track of
3590 the end of the best match so far in a separate variable. We
3591 initialize this to NULL so that when we backtrack the first time
3592 and need to test it, it's not garbage. */
3593 const char *match_end = NULL;
3595 /* This helps SET_REGS_MATCHED avoid doing redundant work. */
3596 int set_regs_matched_done = 0;
3598 /* Used when we pop values we don't care about. */
3599 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3600 const char **reg_dummy;
3601 register_info_type *reg_info_dummy;
3605 /* Counts the total number of registers pushed. */
3606 unsigned num_regs_pushed = 0;
3609 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3613 #ifdef MATCH_MAY_ALLOCATE
3614 /* Do not bother to initialize all the register variables if there are
3615 no groups in the pattern, as it takes a fair amount of time. If
3616 there are groups, we include space for register 0 (the whole
3617 pattern), even though we never use it, since it simplifies the
3618 array indexing. We should fix this. */
3621 regstart = REGEX_TALLOC (num_regs, const char *);
3622 regend = REGEX_TALLOC (num_regs, const char *);
3623 old_regstart = REGEX_TALLOC (num_regs, const char *);
3624 old_regend = REGEX_TALLOC (num_regs, const char *);
3625 best_regstart = REGEX_TALLOC (num_regs, const char *);
3626 best_regend = REGEX_TALLOC (num_regs, const char *);
3627 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3628 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3629 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3631 if (!(regstart && regend && old_regstart && old_regend && reg_info
3632 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3640 /* We must initialize all our variables to NULL, so that
3641 `FREE_VARIABLES' doesn't try to free them. */
3642 regstart = regend = old_regstart = old_regend = best_regstart
3643 = best_regend = reg_dummy = NULL;
3644 reg_info = reg_info_dummy = (register_info_type *) NULL;
3646 #endif /* MATCH_MAY_ALLOCATE */
3648 /* The starting position is bogus. */
3649 if (pos < 0 || pos > size1 + size2)
3655 /* Initialize subexpression text positions to -1 to mark ones that no
3656 start_memory/stop_memory has been seen for. Also initialize the
3657 register information struct. */
3658 for (mcnt = 1; mcnt < num_regs; mcnt++)
3660 regstart[mcnt] = regend[mcnt]
3661 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3663 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3664 IS_ACTIVE (reg_info[mcnt]) = 0;
3665 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3666 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3669 /* We move `string1' into `string2' if the latter's empty -- but not if
3670 `string1' is null. */
3671 if (size2 == 0 && string1 != NULL)
3678 end1 = string1 + size1;
3679 end2 = string2 + size2;
3681 /* Compute where to stop matching, within the two strings. */
3684 end_match_1 = string1 + stop;
3685 end_match_2 = string2;
3690 end_match_2 = string2 + stop - size1;
3693 /* `p' scans through the pattern as `d' scans through the data.
3694 `dend' is the end of the input string that `d' points within. `d'
3695 is advanced into the following input string whenever necessary, but
3696 this happens before fetching; therefore, at the beginning of the
3697 loop, `d' can be pointing at the end of a string, but it cannot
3699 if (size1 > 0 && pos <= size1)
3706 d = string2 + pos - size1;
3710 DEBUG_PRINT1 ("The compiled pattern is: ");
3711 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3712 DEBUG_PRINT1 ("The string to match is: `");
3713 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3714 DEBUG_PRINT1 ("'\n");
3716 /* This loops over pattern commands. It exits by returning from the
3717 function if the match is complete, or it drops through if the match
3718 fails at this starting point in the input data. */
3721 DEBUG_PRINT2 ("\n0x%x: ", p);
3724 { /* End of pattern means we might have succeeded. */
3725 DEBUG_PRINT1 ("end of pattern ... ");
3727 /* If we haven't matched the entire string, and we want the
3728 longest match, try backtracking. */
3729 if (d != end_match_2)
3731 /* 1 if this match ends in the same string (string1 or string2)
3732 as the best previous match. */
3733 boolean same_str_p = (FIRST_STRING_P (match_end)
3734 == MATCHING_IN_FIRST_STRING);
3735 /* 1 if this match is the best seen so far. */
3736 boolean best_match_p;
3738 /* AIX compiler got confused when this was combined
3739 with the previous declaration. */
3741 best_match_p = d > match_end;
3743 best_match_p = !MATCHING_IN_FIRST_STRING;
3745 DEBUG_PRINT1 ("backtracking.\n");
3747 if (!FAIL_STACK_EMPTY ())
3748 { /* More failure points to try. */
3750 /* If exceeds best match so far, save it. */
3751 if (!best_regs_set || best_match_p)
3753 best_regs_set = true;
3756 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3758 for (mcnt = 1; mcnt < num_regs; mcnt++)
3760 best_regstart[mcnt] = regstart[mcnt];
3761 best_regend[mcnt] = regend[mcnt];
3767 /* If no failure points, don't restore garbage. And if
3768 last match is real best match, don't restore second
3770 else if (best_regs_set && !best_match_p)
3773 /* Restore best match. It may happen that `dend ==
3774 end_match_1' while the restored d is in string2.
3775 For example, the pattern `x.*y.*z' against the
3776 strings `x-' and `y-z-', if the two strings are
3777 not consecutive in memory. */
3778 DEBUG_PRINT1 ("Restoring best registers.\n");
3781 dend = ((d >= string1 && d <= end1)
3782 ? end_match_1 : end_match_2);
3784 for (mcnt = 1; mcnt < num_regs; mcnt++)
3786 regstart[mcnt] = best_regstart[mcnt];
3787 regend[mcnt] = best_regend[mcnt];
3790 } /* d != end_match_2 */
3793 DEBUG_PRINT1 ("Accepting match.\n");
3795 /* If caller wants register contents data back, do it. */
3796 if (regs && !bufp->no_sub)
3798 /* Have the register data arrays been allocated? */
3799 if (bufp->regs_allocated == REGS_UNALLOCATED)
3800 { /* No. So allocate them with malloc. We need one
3801 extra element beyond `num_regs' for the `-1' marker
3803 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3804 regs->start = TALLOC (regs->num_regs, regoff_t);
3805 regs->end = TALLOC (regs->num_regs, regoff_t);
3806 if (regs->start == NULL || regs->end == NULL)
3811 bufp->regs_allocated = REGS_REALLOCATE;
3813 else if (bufp->regs_allocated == REGS_REALLOCATE)
3814 { /* Yes. If we need more elements than were already
3815 allocated, reallocate them. If we need fewer, just
3817 if (regs->num_regs < num_regs + 1)
3819 regs->num_regs = num_regs + 1;
3820 RETALLOC (regs->start, regs->num_regs, regoff_t);
3821 RETALLOC (regs->end, regs->num_regs, regoff_t);
3822 if (regs->start == NULL || regs->end == NULL)
3831 /* These braces fend off a "empty body in an else-statement"
3832 warning under GCC when assert expands to nothing. */
3833 assert (bufp->regs_allocated == REGS_FIXED);
3836 /* Convert the pointer data in `regstart' and `regend' to
3837 indices. Register zero has to be set differently,
3838 since we haven't kept track of any info for it. */
3839 if (regs->num_regs > 0)
3841 regs->start[0] = pos;
3842 regs->end[0] = (MATCHING_IN_FIRST_STRING
3843 ? ((regoff_t) (d - string1))
3844 : ((regoff_t) (d - string2 + size1)));
3847 /* Go through the first `min (num_regs, regs->num_regs)'
3848 registers, since that is all we initialized. */
3849 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3851 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3852 regs->start[mcnt] = regs->end[mcnt] = -1;
3856 = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
3858 = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
3862 /* If the regs structure we return has more elements than
3863 were in the pattern, set the extra elements to -1. If
3864 we (re)allocated the registers, this is the case,
3865 because we always allocate enough to have at least one
3867 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3868 regs->start[mcnt] = regs->end[mcnt] = -1;
3869 } /* regs && !bufp->no_sub */
3871 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3872 nfailure_points_pushed, nfailure_points_popped,
3873 nfailure_points_pushed - nfailure_points_popped);
3874 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3876 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3880 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3886 /* Otherwise match next pattern command. */
3887 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
3889 /* Ignore these. Used to ignore the n of succeed_n's which
3890 currently have n == 0. */
3892 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3896 DEBUG_PRINT1 ("EXECUTING succeed.\n");
3899 /* Match the next n pattern characters exactly. The following
3900 byte in the pattern defines n, and the n bytes after that
3901 are the characters to match. */
3904 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3906 /* This is written out as an if-else so we don't waste time
3907 testing `translate' inside the loop. */
3913 if (translate[(unsigned char) *d++] != (char) *p++)
3923 if (*d++ != (char) *p++) goto fail;
3927 SET_REGS_MATCHED ();
3931 /* Match any character except possibly a newline or a null. */
3933 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3937 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3938 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3941 SET_REGS_MATCHED ();
3942 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3950 register unsigned char c;
3951 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3953 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3956 c = TRANSLATE (*d); /* The character to match. */
3958 /* Cast to `unsigned' instead of `unsigned char' in case the
3959 bit list is a full 32 bytes long. */
3960 if (c < (unsigned) (*p * BYTEWIDTH)
3961 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3966 if (!not) goto fail;
3968 SET_REGS_MATCHED ();
3974 /* The beginning of a group is represented by start_memory.
3975 The arguments are the register number in the next byte, and the
3976 number of groups inner to this one in the next. The text
3977 matched within the group is recorded (in the internal
3978 registers data structure) under the register number. */
3980 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3982 /* Find out if this group can match the empty string. */
3983 p1 = p; /* To send to group_match_null_string_p. */
3985 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3986 REG_MATCH_NULL_STRING_P (reg_info[*p])
3987 = group_match_null_string_p (&p1, pend, reg_info);
3989 /* Save the position in the string where we were the last time
3990 we were at this open-group operator in case the group is
3991 operated upon by a repetition operator, e.g., with `(a*)*b'
3992 against `ab'; then we want to ignore where we are now in
3993 the string in case this attempt to match fails. */
3994 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3995 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3997 DEBUG_PRINT2 (" old_regstart: %d\n",
3998 POINTER_TO_OFFSET (old_regstart[*p]));
4001 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
4003 IS_ACTIVE (reg_info[*p]) = 1;
4004 MATCHED_SOMETHING (reg_info[*p]) = 0;
4006 /* Clear this whenever we change the register activity status. */
4007 set_regs_matched_done = 0;
4009 /* This is the new highest active register. */
4010 highest_active_reg = *p;
4012 /* If nothing was active before, this is the new lowest active
4014 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4015 lowest_active_reg = *p;
4017 /* Move past the register number and inner group count. */
4019 just_past_start_mem = p;
4024 /* The stop_memory opcode represents the end of a group. Its
4025 arguments are the same as start_memory's: the register
4026 number, and the number of inner groups. */
4028 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
4030 /* We need to save the string position the last time we were at
4031 this close-group operator in case the group is operated
4032 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
4033 against `aba'; then we want to ignore where we are now in
4034 the string in case this attempt to match fails. */
4035 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4036 ? REG_UNSET (regend[*p]) ? d : regend[*p]
4038 DEBUG_PRINT2 (" old_regend: %d\n",
4039 POINTER_TO_OFFSET (old_regend[*p]));
4042 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
4044 /* This register isn't active anymore. */
4045 IS_ACTIVE (reg_info[*p]) = 0;
4047 /* Clear this whenever we change the register activity status. */
4048 set_regs_matched_done = 0;
4050 /* If this was the only register active, nothing is active
4052 if (lowest_active_reg == highest_active_reg)
4054 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4055 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4058 { /* We must scan for the new highest active register, since
4059 it isn't necessarily one less than now: consider
4060 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
4061 new highest active register is 1. */
4062 unsigned char r = *p - 1;
4063 while (r > 0 && !IS_ACTIVE (reg_info[r]))
4066 /* If we end up at register zero, that means that we saved
4067 the registers as the result of an `on_failure_jump', not
4068 a `start_memory', and we jumped to past the innermost
4069 `stop_memory'. For example, in ((.)*) we save
4070 registers 1 and 2 as a result of the *, but when we pop
4071 back to the second ), we are at the stop_memory 1.
4072 Thus, nothing is active. */
4075 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4076 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4079 highest_active_reg = r;
4082 /* If just failed to match something this time around with a
4083 group that's operated on by a repetition operator, try to
4084 force exit from the ``loop'', and restore the register
4085 information for this group that we had before trying this
4087 if ((!MATCHED_SOMETHING (reg_info[*p])
4088 || just_past_start_mem == p - 1)
4091 boolean is_a_jump_n = false;
4095 switch ((re_opcode_t) *p1++)
4099 case pop_failure_jump:
4100 case maybe_pop_jump:
4102 case dummy_failure_jump:
4103 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4113 /* If the next operation is a jump backwards in the pattern
4114 to an on_failure_jump right before the start_memory
4115 corresponding to this stop_memory, exit from the loop
4116 by forcing a failure after pushing on the stack the
4117 on_failure_jump's jump in the pattern, and d. */
4118 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
4119 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
4121 /* If this group ever matched anything, then restore
4122 what its registers were before trying this last
4123 failed match, e.g., with `(a*)*b' against `ab' for
4124 regstart[1], and, e.g., with `((a*)*(b*)*)*'
4125 against `aba' for regend[3].
4127 Also restore the registers for inner groups for,
4128 e.g., `((a*)(b*))*' against `aba' (register 3 would
4129 otherwise get trashed). */
4131 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
4135 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
4137 /* Restore this and inner groups' (if any) registers. */
4138 for (r = *p; r < *p + *(p + 1); r++)
4140 regstart[r] = old_regstart[r];
4142 /* xx why this test? */
4143 if (old_regend[r] >= regstart[r])
4144 regend[r] = old_regend[r];
4148 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4149 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
4155 /* Move past the register number and the inner group count. */
4160 /* \<digit> has been turned into a `duplicate' command which is
4161 followed by the numeric value of <digit> as the register number. */
4164 register const char *d2, *dend2;
4165 int regno = *p++; /* Get which register to match against. */
4166 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
4168 /* Can't back reference a group which we've never matched. */
4169 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
4172 /* Where in input to try to start matching. */
4173 d2 = regstart[regno];
4175 /* Where to stop matching; if both the place to start and
4176 the place to stop matching are in the same string, then
4177 set to the place to stop, otherwise, for now have to use
4178 the end of the first string. */
4180 dend2 = ((FIRST_STRING_P (regstart[regno])
4181 == FIRST_STRING_P (regend[regno]))
4182 ? regend[regno] : end_match_1);
4185 /* If necessary, advance to next segment in register
4189 if (dend2 == end_match_2) break;
4190 if (dend2 == regend[regno]) break;
4192 /* End of string1 => advance to string2. */
4194 dend2 = regend[regno];
4196 /* At end of register contents => success */
4197 if (d2 == dend2) break;
4199 /* If necessary, advance to next segment in data. */
4202 /* How many characters left in this segment to match. */
4205 /* Want how many consecutive characters we can match in
4206 one shot, so, if necessary, adjust the count. */
4207 if (mcnt > dend2 - d2)
4210 /* Compare that many; failure if mismatch, else move
4213 ? bcmp_translate (d, d2, mcnt, translate)
4214 : bcmp (d, d2, mcnt))
4216 d += mcnt, d2 += mcnt;
4218 /* Do this because we've match some characters. */
4219 SET_REGS_MATCHED ();
4225 /* begline matches the empty string at the beginning of the string
4226 (unless `not_bol' is set in `bufp'), and, if
4227 `newline_anchor' is set, after newlines. */
4229 DEBUG_PRINT1 ("EXECUTING begline.\n");
4231 if (AT_STRINGS_BEG (d))
4233 if (!bufp->not_bol) break;
4235 else if (d[-1] == '\n' && bufp->newline_anchor)
4239 /* In all other cases, we fail. */
4243 /* endline is the dual of begline. */
4245 DEBUG_PRINT1 ("EXECUTING endline.\n");
4247 if (AT_STRINGS_END (d))
4249 if (!bufp->not_eol) break;
4252 /* We have to ``prefetch'' the next character. */
4253 else if ((d == end1 ? *string2 : *d) == '\n'
4254 && bufp->newline_anchor)
4261 /* Match at the very beginning of the data. */
4263 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4264 if (AT_STRINGS_BEG (d))
4269 /* Match at the very end of the data. */
4271 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4272 if (AT_STRINGS_END (d))
4277 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
4278 pushes NULL as the value for the string on the stack. Then
4279 `pop_failure_point' will keep the current value for the
4280 string, instead of restoring it. To see why, consider
4281 matching `foo\nbar' against `.*\n'. The .* matches the foo;
4282 then the . fails against the \n. But the next thing we want
4283 to do is match the \n against the \n; if we restored the
4284 string value, we would be back at the foo.
4286 Because this is used only in specific cases, we don't need to
4287 check all the things that `on_failure_jump' does, to make
4288 sure the right things get saved on the stack. Hence we don't
4289 share its code. The only reason to push anything on the
4290 stack at all is that otherwise we would have to change
4291 `anychar's code to do something besides goto fail in this
4292 case; that seems worse than this. */
4293 case on_failure_keep_string_jump:
4294 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4296 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4297 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4299 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4303 /* Uses of on_failure_jump:
4305 Each alternative starts with an on_failure_jump that points
4306 to the beginning of the next alternative. Each alternative
4307 except the last ends with a jump that in effect jumps past
4308 the rest of the alternatives. (They really jump to the
4309 ending jump of the following alternative, because tensioning
4310 these jumps is a hassle.)
4312 Repeats start with an on_failure_jump that points past both
4313 the repetition text and either the following jump or
4314 pop_failure_jump back to this on_failure_jump. */
4315 case on_failure_jump:
4317 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4319 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4320 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4322 /* If this on_failure_jump comes right before a group (i.e.,
4323 the original * applied to a group), save the information
4324 for that group and all inner ones, so that if we fail back
4325 to this point, the group's information will be correct.
4326 For example, in \(a*\)*\1, we need the preceding group,
4327 and in \(\(a*\)b*\)\2, we need the inner group. */
4329 /* We can't use `p' to check ahead because we push
4330 a failure point to `p + mcnt' after we do this. */
4333 /* We need to skip no_op's before we look for the
4334 start_memory in case this on_failure_jump is happening as
4335 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
4337 while (p1 < pend && (re_opcode_t) *p1 == no_op)
4340 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
4342 /* We have a new highest active register now. This will
4343 get reset at the start_memory we are about to get to,
4344 but we will have saved all the registers relevant to
4345 this repetition op, as described above. */
4346 highest_active_reg = *(p1 + 1) + *(p1 + 2);
4347 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4348 lowest_active_reg = *(p1 + 1);
4351 DEBUG_PRINT1 (":\n");
4352 PUSH_FAILURE_POINT (p + mcnt, d, -2);
4356 /* A smart repeat ends with `maybe_pop_jump'.
4357 We change it to either `pop_failure_jump' or `jump'. */
4358 case maybe_pop_jump:
4359 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4360 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4362 register unsigned char *p2 = p;
4364 /* Compare the beginning of the repeat with what in the
4365 pattern follows its end. If we can establish that there
4366 is nothing that they would both match, i.e., that we
4367 would have to backtrack because of (as in, e.g., `a*a')
4368 then we can change to pop_failure_jump, because we'll
4369 never have to backtrack.
4371 This is not true in the case of alternatives: in
4372 `(a|ab)*' we do need to backtrack to the `ab' alternative
4373 (e.g., if the string was `ab'). But instead of trying to
4374 detect that here, the alternative has put on a dummy
4375 failure point which is what we will end up popping. */
4377 /* Skip over open/close-group commands.
4378 If what follows this loop is a ...+ construct,
4379 look at what begins its body, since we will have to
4380 match at least one of that. */
4384 && ((re_opcode_t) *p2 == stop_memory
4385 || (re_opcode_t) *p2 == start_memory))
4387 else if (p2 + 6 < pend
4388 && (re_opcode_t) *p2 == dummy_failure_jump)
4395 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4396 to the `maybe_finalize_jump' of this case. Examine what
4399 /* If we're at the end of the pattern, we can change. */
4402 /* Consider what happens when matching ":\(.*\)"
4403 against ":/". I don't really understand this code
4405 p[-3] = (unsigned char) pop_failure_jump;
4407 (" End of pattern: change to `pop_failure_jump'.\n");
4410 else if ((re_opcode_t) *p2 == exactn
4411 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4413 register unsigned char c
4414 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4416 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4418 p[-3] = (unsigned char) pop_failure_jump;
4419 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4423 else if ((re_opcode_t) p1[3] == charset
4424 || (re_opcode_t) p1[3] == charset_not)
4426 int not = (re_opcode_t) p1[3] == charset_not;
4428 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4429 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4432 /* `not' is equal to 1 if c would match, which means
4433 that we can't change to pop_failure_jump. */
4436 p[-3] = (unsigned char) pop_failure_jump;
4437 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4441 else if ((re_opcode_t) *p2 == charset)
4444 register unsigned char c
4445 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4448 if ((re_opcode_t) p1[3] == exactn
4449 && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
4450 && (p2[1 + p1[4] / BYTEWIDTH]
4451 & (1 << (p1[4] % BYTEWIDTH)))))
4453 p[-3] = (unsigned char) pop_failure_jump;
4454 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4458 else if ((re_opcode_t) p1[3] == charset_not)
4461 /* We win if the charset_not inside the loop
4462 lists every character listed in the charset after. */
4463 for (idx = 0; idx < (int) p2[1]; idx++)
4464 if (! (p2[2 + idx] == 0
4465 || (idx < (int) p1[4]
4466 && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
4471 p[-3] = (unsigned char) pop_failure_jump;
4472 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4475 else if ((re_opcode_t) p1[3] == charset)
4478 /* We win if the charset inside the loop
4479 has no overlap with the one after the loop. */
4481 idx < (int) p2[1] && idx < (int) p1[4];
4483 if ((p2[2 + idx] & p1[5 + idx]) != 0)
4486 if (idx == p2[1] || idx == p1[4])
4488 p[-3] = (unsigned char) pop_failure_jump;
4489 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4494 p -= 2; /* Point at relative address again. */
4495 if ((re_opcode_t) p[-1] != pop_failure_jump)
4497 p[-1] = (unsigned char) jump;
4498 DEBUG_PRINT1 (" Match => jump.\n");
4499 goto unconditional_jump;
4501 /* Note fall through. */
4504 /* The end of a simple repeat has a pop_failure_jump back to
4505 its matching on_failure_jump, where the latter will push a
4506 failure point. The pop_failure_jump takes off failure
4507 points put on by this pop_failure_jump's matching
4508 on_failure_jump; we got through the pattern to here from the
4509 matching on_failure_jump, so didn't fail. */
4510 case pop_failure_jump:
4512 /* We need to pass separate storage for the lowest and
4513 highest registers, even though we don't care about the
4514 actual values. Otherwise, we will restore only one
4515 register from the stack, since lowest will == highest in
4516 `pop_failure_point'. */
4517 unsigned dummy_low_reg, dummy_high_reg;
4518 unsigned char *pdummy;
4521 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4522 POP_FAILURE_POINT (sdummy, pdummy,
4523 dummy_low_reg, dummy_high_reg,
4524 reg_dummy, reg_dummy, reg_info_dummy);
4526 /* Note fall through. */
4529 /* Unconditionally jump (without popping any failure points). */
4532 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4533 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4534 p += mcnt; /* Do the jump. */
4535 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4539 /* We need this opcode so we can detect where alternatives end
4540 in `group_match_null_string_p' et al. */
4542 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4543 goto unconditional_jump;
4546 /* Normally, the on_failure_jump pushes a failure point, which
4547 then gets popped at pop_failure_jump. We will end up at
4548 pop_failure_jump, also, and with a pattern of, say, `a+', we
4549 are skipping over the on_failure_jump, so we have to push
4550 something meaningless for pop_failure_jump to pop. */
4551 case dummy_failure_jump:
4552 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4553 /* It doesn't matter what we push for the string here. What
4554 the code at `fail' tests is the value for the pattern. */
4555 PUSH_FAILURE_POINT (0, 0, -2);
4556 goto unconditional_jump;
4559 /* At the end of an alternative, we need to push a dummy failure
4560 point in case we are followed by a `pop_failure_jump', because
4561 we don't want the failure point for the alternative to be
4562 popped. For example, matching `(a|ab)*' against `aab'
4563 requires that we match the `ab' alternative. */
4564 case push_dummy_failure:
4565 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4566 /* See comments just above at `dummy_failure_jump' about the
4568 PUSH_FAILURE_POINT (0, 0, -2);
4571 /* Have to succeed matching what follows at least n times.
4572 After that, handle like `on_failure_jump'. */
4574 EXTRACT_NUMBER (mcnt, p + 2);
4575 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4578 /* Originally, this is how many times we HAVE to succeed. */
4583 STORE_NUMBER_AND_INCR (p, mcnt);
4584 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4588 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4589 p[2] = (unsigned char) no_op;
4590 p[3] = (unsigned char) no_op;
4596 EXTRACT_NUMBER (mcnt, p + 2);
4597 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4599 /* Originally, this is how many times we CAN jump. */
4603 STORE_NUMBER (p + 2, mcnt);
4604 goto unconditional_jump;
4606 /* If don't have to jump any more, skip over the rest of command. */
4613 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4615 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4617 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4618 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4619 STORE_NUMBER (p1, mcnt);
4624 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4625 if (AT_WORD_BOUNDARY (d))
4630 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4631 if (AT_WORD_BOUNDARY (d))
4636 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4637 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4642 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4643 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4644 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4650 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4651 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4656 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4657 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4662 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4663 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4666 #if 0 /* not emacs19 */
4668 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4669 if (PTR_CHAR_POS ((unsigned char *) d) + 1 != point)
4672 #endif /* not emacs19 */
4675 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4680 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4684 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4686 if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
4688 SET_REGS_MATCHED ();
4692 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4694 goto matchnotsyntax;
4697 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4701 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4703 if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
4705 SET_REGS_MATCHED ();
4708 #else /* not emacs */
4710 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4712 if (!WORDCHAR_P (d))
4714 SET_REGS_MATCHED ();
4719 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4723 SET_REGS_MATCHED ();
4726 #endif /* not emacs */
4731 continue; /* Successfully executed one pattern command; keep going. */
4734 /* We goto here if a matching operation fails. */
4736 if (!FAIL_STACK_EMPTY ())
4737 { /* A restart point is known. Restore to that state. */
4738 DEBUG_PRINT1 ("\nFAIL:\n");
4739 POP_FAILURE_POINT (d, p,
4740 lowest_active_reg, highest_active_reg,
4741 regstart, regend, reg_info);
4743 /* If this failure point is a dummy, try the next one. */
4747 /* If we failed to the end of the pattern, don't examine *p. */
4751 boolean is_a_jump_n = false;
4753 /* If failed to a backwards jump that's part of a repetition
4754 loop, need to pop this failure point and use the next one. */
4755 switch ((re_opcode_t) *p)
4759 case maybe_pop_jump:
4760 case pop_failure_jump:
4763 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4766 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4768 && (re_opcode_t) *p1 == on_failure_jump))
4776 if (d >= string1 && d <= end1)
4780 break; /* Matching at this starting point really fails. */
4784 goto restore_best_regs;
4788 return -1; /* Failure to match. */
4791 /* Subroutine definitions for re_match_2. */
4794 /* We are passed P pointing to a register number after a start_memory.
4796 Return true if the pattern up to the corresponding stop_memory can
4797 match the empty string, and false otherwise.
4799 If we find the matching stop_memory, sets P to point to one past its number.
4800 Otherwise, sets P to an undefined byte less than or equal to END.
4802 We don't handle duplicates properly (yet). */
4805 group_match_null_string_p (p, end, reg_info)
4806 unsigned char **p, *end;
4807 register_info_type *reg_info;
4810 /* Point to after the args to the start_memory. */
4811 unsigned char *p1 = *p + 2;
4815 /* Skip over opcodes that can match nothing, and return true or
4816 false, as appropriate, when we get to one that can't, or to the
4817 matching stop_memory. */
4819 switch ((re_opcode_t) *p1)
4821 /* Could be either a loop or a series of alternatives. */
4822 case on_failure_jump:
4824 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4826 /* If the next operation is not a jump backwards in the
4831 /* Go through the on_failure_jumps of the alternatives,
4832 seeing if any of the alternatives cannot match nothing.
4833 The last alternative starts with only a jump,
4834 whereas the rest start with on_failure_jump and end
4835 with a jump, e.g., here is the pattern for `a|b|c':
4837 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4838 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4841 So, we have to first go through the first (n-1)
4842 alternatives and then deal with the last one separately. */
4845 /* Deal with the first (n-1) alternatives, which start
4846 with an on_failure_jump (see above) that jumps to right
4847 past a jump_past_alt. */
4849 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4851 /* `mcnt' holds how many bytes long the alternative
4852 is, including the ending `jump_past_alt' and
4855 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4859 /* Move to right after this alternative, including the
4863 /* Break if it's the beginning of an n-th alternative
4864 that doesn't begin with an on_failure_jump. */
4865 if ((re_opcode_t) *p1 != on_failure_jump)
4868 /* Still have to check that it's not an n-th
4869 alternative that starts with an on_failure_jump. */
4871 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4872 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4874 /* Get to the beginning of the n-th alternative. */
4880 /* Deal with the last alternative: go back and get number
4881 of the `jump_past_alt' just before it. `mcnt' contains
4882 the length of the alternative. */
4883 EXTRACT_NUMBER (mcnt, p1 - 2);
4885 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4888 p1 += mcnt; /* Get past the n-th alternative. */
4894 assert (p1[1] == **p);
4900 if (!common_op_match_null_string_p (&p1, end, reg_info))
4903 } /* while p1 < end */
4906 } /* group_match_null_string_p */
4909 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4910 It expects P to be the first byte of a single alternative and END one
4911 byte past the last. The alternative can contain groups. */
4914 alt_match_null_string_p (p, end, reg_info)
4915 unsigned char *p, *end;
4916 register_info_type *reg_info;
4919 unsigned char *p1 = p;
4923 /* Skip over opcodes that can match nothing, and break when we get
4924 to one that can't. */
4926 switch ((re_opcode_t) *p1)
4929 case on_failure_jump:
4931 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4936 if (!common_op_match_null_string_p (&p1, end, reg_info))
4939 } /* while p1 < end */
4942 } /* alt_match_null_string_p */
4945 /* Deals with the ops common to group_match_null_string_p and
4946 alt_match_null_string_p.
4948 Sets P to one after the op and its arguments, if any. */
4951 common_op_match_null_string_p (p, end, reg_info)
4952 unsigned char **p, *end;
4953 register_info_type *reg_info;
4958 unsigned char *p1 = *p;
4960 switch ((re_opcode_t) *p1++)
4980 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
4981 ret = group_match_null_string_p (&p1, end, reg_info);
4983 /* Have to set this here in case we're checking a group which
4984 contains a group and a back reference to it. */
4986 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
4987 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
4993 /* If this is an optimized succeed_n for zero times, make the jump. */
4995 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5003 /* Get to the number of times to succeed. */
5005 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5010 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5018 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
5026 /* All other opcodes mean we cannot match the empty string. */
5032 } /* common_op_match_null_string_p */
5035 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
5036 bytes; nonzero otherwise. */
5039 bcmp_translate (s1, s2, len, translate)
5040 unsigned char *s1, *s2;
5044 register unsigned char *p1 = s1, *p2 = s2;
5047 if (translate[*p1++] != translate[*p2++]) return 1;
5053 /* Entry points for GNU code. */
5055 /* re_compile_pattern is the GNU regular expression compiler: it
5056 compiles PATTERN (of length SIZE) and puts the result in BUFP.
5057 Returns 0 if the pattern was valid, otherwise an error string.
5059 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
5060 are set in BUFP on entry.
5062 We call regex_compile to do the actual compilation. */
5065 re_compile_pattern (pattern, length, bufp)
5066 const char *pattern;
5068 struct re_pattern_buffer *bufp;
5072 /* GNU code is written to assume at least RE_NREGS registers will be set
5073 (and at least one extra will be -1). */
5074 bufp->regs_allocated = REGS_UNALLOCATED;
5076 /* And GNU code determines whether or not to get register information
5077 by passing null for the REGS argument to re_match, etc., not by
5081 /* Match anchors at newline. */
5082 bufp->newline_anchor = 1;
5084 ret = regex_compile (pattern, length, re_syntax_options, bufp);
5088 return gettext (re_error_msgid[(int) ret]);
5091 /* Entry points compatible with 4.2 BSD regex library. We don't define
5092 them unless specifically requested. */
5094 #ifdef _REGEX_RE_COMP
5096 /* BSD has one and only one pattern buffer. */
5097 static struct re_pattern_buffer re_comp_buf;
5107 if (!re_comp_buf.buffer)
5108 return gettext ("No previous regular expression");
5112 if (!re_comp_buf.buffer)
5114 re_comp_buf.buffer = (unsigned char *) malloc (200);
5115 if (re_comp_buf.buffer == NULL)
5116 return gettext (re_error_msgid[(int) REG_ESPACE]);
5117 re_comp_buf.allocated = 200;
5119 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
5120 if (re_comp_buf.fastmap == NULL)
5121 return gettext (re_error_msgid[(int) REG_ESPACE]);
5124 /* Since `re_exec' always passes NULL for the `regs' argument, we
5125 don't need to initialize the pattern buffer fields which affect it. */
5127 /* Match anchors at newlines. */
5128 re_comp_buf.newline_anchor = 1;
5130 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
5135 /* Yes, we're discarding `const' here if !HAVE_LIBINTL. */
5136 return (char *) gettext (re_error_msgid[(int) ret]);
5144 const int len = strlen (s);
5146 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
5148 #endif /* _REGEX_RE_COMP */
5150 /* POSIX.2 functions. Don't define these for Emacs. */
5154 /* regcomp takes a regular expression as a string and compiles it.
5156 PREG is a regex_t *. We do not expect any fields to be initialized,
5157 since POSIX says we shouldn't. Thus, we set
5159 `buffer' to the compiled pattern;
5160 `used' to the length of the compiled pattern;
5161 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
5162 REG_EXTENDED bit in CFLAGS is set; otherwise, to
5163 RE_SYNTAX_POSIX_BASIC;
5164 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
5165 `fastmap' and `fastmap_accurate' to zero;
5166 `re_nsub' to the number of subexpressions in PATTERN.
5168 PATTERN is the address of the pattern string.
5170 CFLAGS is a series of bits which affect compilation.
5172 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
5173 use POSIX basic syntax.
5175 If REG_NEWLINE is set, then . and [^...] don't match newline.
5176 Also, regexec will try a match beginning after every newline.
5178 If REG_ICASE is set, then we considers upper- and lowercase
5179 versions of letters to be equivalent when matching.
5181 If REG_NOSUB is set, then when PREG is passed to regexec, that
5182 routine will report only success or failure, and nothing about the
5185 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
5186 the return codes and their meanings.) */
5189 regcomp (preg, pattern, cflags)
5191 const char *pattern;
5196 = (cflags & REG_EXTENDED) ?
5197 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
5199 /* regex_compile will allocate the space for the compiled pattern. */
5201 preg->allocated = 0;
5204 /* Don't bother to use a fastmap when searching. This simplifies the
5205 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
5206 characters after newlines into the fastmap. This way, we just try
5210 if (cflags & REG_ICASE)
5214 preg->translate = (char *) malloc (CHAR_SET_SIZE);
5215 if (preg->translate == NULL)
5216 return (int) REG_ESPACE;
5218 /* Map uppercase characters to corresponding lowercase ones. */
5219 for (i = 0; i < CHAR_SET_SIZE; i++)
5220 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
5223 preg->translate = NULL;
5225 /* If REG_NEWLINE is set, newlines are treated differently. */
5226 if (cflags & REG_NEWLINE)
5227 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
5228 syntax &= ~RE_DOT_NEWLINE;
5229 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
5230 /* It also changes the matching behavior. */
5231 preg->newline_anchor = 1;
5234 preg->newline_anchor = 0;
5236 preg->no_sub = !!(cflags & REG_NOSUB);
5238 /* POSIX says a null character in the pattern terminates it, so we
5239 can use strlen here in compiling the pattern. */
5240 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
5242 /* POSIX doesn't distinguish between an unmatched open-group and an
5243 unmatched close-group: both are REG_EPAREN. */
5244 if (ret == REG_ERPAREN) ret = REG_EPAREN;
5250 /* regexec searches for a given pattern, specified by PREG, in the
5253 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
5254 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
5255 least NMATCH elements, and we set them to the offsets of the
5256 corresponding matched substrings.
5258 EFLAGS specifies `execution flags' which affect matching: if
5259 REG_NOTBOL is set, then ^ does not match at the beginning of the
5260 string; if REG_NOTEOL is set, then $ does not match at the end.
5262 We return 0 if we find a match and REG_NOMATCH if not. */
5265 regexec (preg, string, nmatch, pmatch, eflags)
5266 const regex_t *preg;
5269 regmatch_t pmatch[];
5273 struct re_registers regs;
5274 regex_t private_preg;
5275 int len = strlen (string);
5276 boolean want_reg_info = !preg->no_sub && nmatch > 0;
5278 private_preg = *preg;
5280 private_preg.not_bol = !!(eflags & REG_NOTBOL);
5281 private_preg.not_eol = !!(eflags & REG_NOTEOL);
5283 /* The user has told us exactly how many registers to return
5284 information about, via `nmatch'. We have to pass that on to the
5285 matching routines. */
5286 private_preg.regs_allocated = REGS_FIXED;
5290 regs.num_regs = nmatch;
5291 regs.start = TALLOC (nmatch, regoff_t);
5292 regs.end = TALLOC (nmatch, regoff_t);
5293 if (regs.start == NULL || regs.end == NULL)
5294 return (int) REG_NOMATCH;
5297 /* Perform the searching operation. */
5298 ret = re_search (&private_preg, string, len,
5299 /* start: */ 0, /* range: */ len,
5300 want_reg_info ? ®s : (struct re_registers *) 0);
5302 /* Copy the register information to the POSIX structure. */
5309 for (r = 0; r < nmatch; r++)
5311 pmatch[r].rm_so = regs.start[r];
5312 pmatch[r].rm_eo = regs.end[r];
5316 /* If we needed the temporary register info, free the space now. */
5321 /* We want zero return to mean success, unlike `re_search'. */
5322 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5326 /* Returns a message corresponding to an error code, ERRCODE, returned
5327 from either regcomp or regexec. We don't use PREG here. */
5330 regerror (errcode, preg, errbuf, errbuf_size)
5332 const regex_t *preg;
5340 || errcode >= (sizeof (re_error_msgid) / sizeof (re_error_msgid[0])))
5341 /* Only error codes returned by the rest of the code should be passed
5342 to this routine. If we are given anything else, or if other regex
5343 code generates an invalid error code, then the program has a bug.
5344 Dump core so we can fix it. */
5347 msg = gettext (re_error_msgid[errcode]);
5349 msg_size = strlen (msg) + 1; /* Includes the null. */
5351 if (errbuf_size != 0)
5353 if (msg_size > errbuf_size)
5355 strncpy (errbuf, msg, errbuf_size - 1);
5356 errbuf[errbuf_size - 1] = 0;
5359 strcpy (errbuf, msg);
5366 /* Free dynamically allocated space used by PREG. */
5372 if (preg->buffer != NULL)
5373 free (preg->buffer);
5374 preg->buffer = NULL;
5376 preg->allocated = 0;
5379 if (preg->fastmap != NULL)
5380 free (preg->fastmap);
5381 preg->fastmap = NULL;
5382 preg->fastmap_accurate = 0;
5384 if (preg->translate != NULL)
5385 free (preg->translate);
5386 preg->translate = NULL;
5389 #endif /* not emacs */
5393 make-backup-files: t
5395 trim-versions-without-asking: nil