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. */
52 #define WIDE_INT EMACS_INT
63 /* This isn't right--it needs to check for machines with 64-bit pointers
64 and do something different. But I don't know what, and I don't
65 need to deal with it right now. -- rms. */
68 /* We used to test for `BSTRING' here, but only GCC and Emacs define
69 `BSTRING', as far as I know, and neither of them use this code. */
70 #ifndef INHIBIT_STRING_HEADER
71 #if HAVE_STRING_H || STDC_HEADERS
74 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
77 #define bcopy(s, d, n) memcpy ((d), (s), (n))
80 #define bzero(s, n) memset ((s), 0, (n))
87 /* Define the syntax stuff for \<, \>, etc. */
89 /* This must be nonzero for the wordchar and notwordchar pattern
90 commands in re_match_2. */
95 #ifdef SWITCH_ENUM_BUG
96 #define SWITCH_ENUM_CAST(x) ((int)(x))
98 #define SWITCH_ENUM_CAST(x) (x)
103 extern char *re_syntax_table;
105 #else /* not SYNTAX_TABLE */
107 /* How many characters in the character set. */
108 #define CHAR_SET_SIZE 256
110 static char re_syntax_table[CHAR_SET_SIZE];
121 bzero (re_syntax_table, sizeof re_syntax_table);
123 for (c = 'a'; c <= 'z'; c++)
124 re_syntax_table[c] = Sword;
126 for (c = 'A'; c <= 'Z'; c++)
127 re_syntax_table[c] = Sword;
129 for (c = '0'; c <= '9'; c++)
130 re_syntax_table[c] = Sword;
132 re_syntax_table['_'] = Sword;
137 #endif /* not SYNTAX_TABLE */
139 #define SYNTAX(c) re_syntax_table[c]
141 #endif /* not emacs */
143 /* Get the interface, including the syntax bits. */
146 /* isalpha etc. are used for the character classes. */
149 /* Jim Meyering writes:
151 "... Some ctype macros are valid only for character codes that
152 isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
153 using /bin/cc or gcc but without giving an ansi option). So, all
154 ctype uses should be through macros like ISPRINT... If
155 STDC_HEADERS is defined, then autoconf has verified that the ctype
156 macros don't need to be guarded with references to isascii. ...
157 Defining isascii to 1 should let any compiler worth its salt
158 eliminate the && through constant folding." */
160 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
163 #define ISASCII(c) isascii(c)
167 #define ISBLANK(c) (ISASCII (c) && isblank (c))
169 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
172 #define ISGRAPH(c) (ISASCII (c) && isgraph (c))
174 #define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
177 #define ISPRINT(c) (ISASCII (c) && isprint (c))
178 #define ISDIGIT(c) (ISASCII (c) && isdigit (c))
179 #define ISALNUM(c) (ISASCII (c) && isalnum (c))
180 #define ISALPHA(c) (ISASCII (c) && isalpha (c))
181 #define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
182 #define ISLOWER(c) (ISASCII (c) && islower (c))
183 #define ISPUNCT(c) (ISASCII (c) && ispunct (c))
184 #define ISSPACE(c) (ISASCII (c) && isspace (c))
185 #define ISUPPER(c) (ISASCII (c) && isupper (c))
186 #define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
192 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
193 since ours (we hope) works properly with all combinations of
194 machines, compilers, `char' and `unsigned char' argument types.
195 (Per Bothner suggested the basic approach.) */
196 #undef SIGN_EXTEND_CHAR
198 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
199 #else /* not __STDC__ */
200 /* As in Harbison and Steele. */
201 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
204 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
205 use `alloca' instead of `malloc'. This is because using malloc in
206 re_search* or re_match* could cause memory leaks when C-g is used in
207 Emacs; also, malloc is slower and causes storage fragmentation. On
208 the other hand, malloc is more portable, and easier to debug.
210 Because we sometimes use alloca, some routines have to be macros,
211 not functions -- `alloca'-allocated space disappears at the end of the
212 function it is called in. */
216 #define REGEX_ALLOCATE malloc
217 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
218 #define REGEX_FREE free
220 #else /* not REGEX_MALLOC */
222 /* Emacs already defines alloca, sometimes. */
225 /* Make alloca work the best possible way. */
227 #define alloca __builtin_alloca
228 #else /* not __GNUC__ */
231 #else /* not __GNUC__ or HAVE_ALLOCA_H */
232 #ifndef _AIX /* Already did AIX, up at the top. */
234 #endif /* not _AIX */
235 #endif /* not HAVE_ALLOCA_H */
236 #endif /* not __GNUC__ */
238 #endif /* not alloca */
240 #define REGEX_ALLOCATE alloca
242 /* Assumes a `char *destination' variable. */
243 #define REGEX_REALLOCATE(source, osize, nsize) \
244 (destination = (char *) alloca (nsize), \
245 bcopy (source, destination, osize), \
248 /* No need to do anything to free, after alloca. */
249 #define REGEX_FREE(arg) (0)
251 #endif /* not REGEX_MALLOC */
253 /* Define how to allocate the failure stack. */
256 #define REGEX_ALLOCATE_STACK(size) \
257 r_alloc (&failure_stack_ptr, (size))
258 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
259 r_re_alloc (&failure_stack_ptr, (nsize))
260 #define REGEX_FREE_STACK(ptr) \
261 r_alloc_free (&failure_stack_ptr)
263 #else /* not REL_ALLOC */
267 #define REGEX_ALLOCATE_STACK malloc
268 #define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
269 #define REGEX_FREE_STACK free
271 #else /* not REGEX_MALLOC */
273 #define REGEX_ALLOCATE_STACK alloca
275 #define REGEX_REALLOCATE_STACK(source, osize, nsize) \
276 REGEX_REALLOCATE (source, osize, nsize)
277 /* No need to explicitly free anything. */
278 #define REGEX_FREE_STACK(arg)
280 #endif /* not REGEX_MALLOC */
281 #endif /* not REL_ALLOC */
284 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
285 `string1' or just past its end. This works if PTR is NULL, which is
287 #define FIRST_STRING_P(ptr) \
288 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
290 /* (Re)Allocate N items of type T using malloc, or fail. */
291 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
292 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
293 #define RETALLOC_IF(addr, n, t) \
294 if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
295 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
297 #define BYTEWIDTH 8 /* In bits. */
299 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
303 #define MAX(a, b) ((a) > (b) ? (a) : (b))
304 #define MIN(a, b) ((a) < (b) ? (a) : (b))
306 typedef char boolean;
310 static int re_match_2_internal ();
312 /* These are the command codes that appear in compiled regular
313 expressions. Some opcodes are followed by argument bytes. A
314 command code can specify any interpretation whatsoever for its
315 arguments. Zero bytes may appear in the compiled regular expression. */
321 /* Succeed right away--no more backtracking. */
324 /* Followed by one byte giving n, then by n literal bytes. */
327 /* Matches any (more or less) character. */
330 /* Matches any one char belonging to specified set. First
331 following byte is number of bitmap bytes. Then come bytes
332 for a bitmap saying which chars are in. Bits in each byte
333 are ordered low-bit-first. A character is in the set if its
334 bit is 1. A character too large to have a bit in the map is
335 automatically not in the set. */
338 /* Same parameters as charset, but match any character that is
339 not one of those specified. */
342 /* Start remembering the text that is matched, for storing in a
343 register. Followed by one byte with the register number, in
344 the range 0 to one less than the pattern buffer's re_nsub
345 field. Then followed by one byte with the number of groups
346 inner to this one. (This last has to be part of the
347 start_memory only because we need it in the on_failure_jump
351 /* Stop remembering the text that is matched and store it in a
352 memory register. Followed by one byte with the register
353 number, in the range 0 to one less than `re_nsub' in the
354 pattern buffer, and one byte with the number of inner groups,
355 just like `start_memory'. (We need the number of inner
356 groups here because we don't have any easy way of finding the
357 corresponding start_memory when we're at a stop_memory.) */
360 /* Match a duplicate of something remembered. Followed by one
361 byte containing the register number. */
364 /* Fail unless at beginning of line. */
367 /* Fail unless at end of line. */
370 /* Succeeds if at beginning of buffer (if emacs) or at beginning
371 of string to be matched (if not). */
374 /* Analogously, for end of buffer/string. */
377 /* Followed by two byte relative address to which to jump. */
380 /* Same as jump, but marks the end of an alternative. */
383 /* Followed by two-byte relative address of place to resume at
384 in case of failure. */
387 /* Like on_failure_jump, but pushes a placeholder instead of the
388 current string position when executed. */
389 on_failure_keep_string_jump,
391 /* Throw away latest failure point and then jump to following
392 two-byte relative address. */
395 /* Change to pop_failure_jump if know won't have to backtrack to
396 match; otherwise change to jump. This is used to jump
397 back to the beginning of a repeat. If what follows this jump
398 clearly won't match what the repeat does, such that we can be
399 sure that there is no use backtracking out of repetitions
400 already matched, then we change it to a pop_failure_jump.
401 Followed by two-byte address. */
404 /* Jump to following two-byte address, and push a dummy failure
405 point. This failure point will be thrown away if an attempt
406 is made to use it for a failure. A `+' construct makes this
407 before the first repeat. Also used as an intermediary kind
408 of jump when compiling an alternative. */
411 /* Push a dummy failure point and continue. Used at the end of
415 /* Followed by two-byte relative address and two-byte number n.
416 After matching N times, jump to the address upon failure. */
419 /* Followed by two-byte relative address, and two-byte number n.
420 Jump to the address N times, then fail. */
423 /* Set the following two-byte relative address to the
424 subsequent two-byte number. The address *includes* the two
428 wordchar, /* Matches any word-constituent character. */
429 notwordchar, /* Matches any char that is not a word-constituent. */
431 wordbeg, /* Succeeds if at word beginning. */
432 wordend, /* Succeeds if at word end. */
434 wordbound, /* Succeeds if at a word boundary. */
435 notwordbound /* Succeeds if not at a word boundary. */
438 ,before_dot, /* Succeeds if before point. */
439 at_dot, /* Succeeds if at point. */
440 after_dot, /* Succeeds if after point. */
442 /* Matches any character whose syntax is specified. Followed by
443 a byte which contains a syntax code, e.g., Sword. */
446 /* Matches any character whose syntax is not that specified. */
451 /* Common operations on the compiled pattern. */
453 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
455 #define STORE_NUMBER(destination, number) \
457 (destination)[0] = (number) & 0377; \
458 (destination)[1] = (number) >> 8; \
461 /* Same as STORE_NUMBER, except increment DESTINATION to
462 the byte after where the number is stored. Therefore, DESTINATION
463 must be an lvalue. */
465 #define STORE_NUMBER_AND_INCR(destination, number) \
467 STORE_NUMBER (destination, number); \
468 (destination) += 2; \
471 /* Put into DESTINATION a number stored in two contiguous bytes starting
474 #define EXTRACT_NUMBER(destination, source) \
476 (destination) = *(source) & 0377; \
477 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
482 extract_number (dest, source)
484 unsigned char *source;
486 int temp = SIGN_EXTEND_CHAR (*(source + 1));
487 *dest = *source & 0377;
491 #ifndef EXTRACT_MACROS /* To debug the macros. */
492 #undef EXTRACT_NUMBER
493 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
494 #endif /* not EXTRACT_MACROS */
498 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
499 SOURCE must be an lvalue. */
501 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
503 EXTRACT_NUMBER (destination, source); \
509 extract_number_and_incr (destination, source)
511 unsigned char **source;
513 extract_number (destination, *source);
517 #ifndef EXTRACT_MACROS
518 #undef EXTRACT_NUMBER_AND_INCR
519 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
520 extract_number_and_incr (&dest, &src)
521 #endif /* not EXTRACT_MACROS */
525 /* If DEBUG is defined, Regex prints many voluminous messages about what
526 it is doing (if the variable `debug' is nonzero). If linked with the
527 main program in `iregex.c', you can enter patterns and strings
528 interactively. And if linked with the main program in `main.c' and
529 the other test files, you can run the already-written tests. */
533 /* We use standard I/O for debugging. */
536 /* It is useful to test things that ``must'' be true when debugging. */
539 static int debug = 0;
541 #define DEBUG_STATEMENT(e) e
542 #define DEBUG_PRINT1(x) if (debug) printf (x)
543 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
544 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
545 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
546 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
547 if (debug) print_partial_compiled_pattern (s, e)
548 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
549 if (debug) print_double_string (w, s1, sz1, s2, sz2)
552 /* Print the fastmap in human-readable form. */
555 print_fastmap (fastmap)
558 unsigned was_a_range = 0;
561 while (i < (1 << BYTEWIDTH))
567 while (i < (1 << BYTEWIDTH) && fastmap[i])
583 /* Print a compiled pattern string in human-readable form, starting at
584 the START pointer into it and ending just before the pointer END. */
587 print_partial_compiled_pattern (start, end)
588 unsigned char *start;
592 unsigned char *p = start;
593 unsigned char *pend = end;
601 /* Loop over pattern commands. */
604 printf ("%d:\t", p - start);
606 switch ((re_opcode_t) *p++)
614 printf ("/exactn/%d", mcnt);
625 printf ("/start_memory/%d/%d", mcnt, *p++);
630 printf ("/stop_memory/%d/%d", mcnt, *p++);
634 printf ("/duplicate/%d", *p++);
644 register int c, last = -100;
645 register int in_range = 0;
647 printf ("/charset [%s",
648 (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
650 assert (p + *p < pend);
652 for (c = 0; c < 256; c++)
654 && (p[1 + (c/8)] & (1 << (c % 8))))
656 /* Are we starting a range? */
657 if (last + 1 == c && ! in_range)
662 /* Have we broken a range? */
663 else if (last + 1 != c && in_range)
692 case on_failure_jump:
693 extract_number_and_incr (&mcnt, &p);
694 printf ("/on_failure_jump to %d", p + mcnt - start);
697 case on_failure_keep_string_jump:
698 extract_number_and_incr (&mcnt, &p);
699 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
702 case dummy_failure_jump:
703 extract_number_and_incr (&mcnt, &p);
704 printf ("/dummy_failure_jump to %d", p + mcnt - start);
707 case push_dummy_failure:
708 printf ("/push_dummy_failure");
712 extract_number_and_incr (&mcnt, &p);
713 printf ("/maybe_pop_jump to %d", p + mcnt - start);
716 case pop_failure_jump:
717 extract_number_and_incr (&mcnt, &p);
718 printf ("/pop_failure_jump to %d", p + mcnt - start);
722 extract_number_and_incr (&mcnt, &p);
723 printf ("/jump_past_alt to %d", p + mcnt - start);
727 extract_number_and_incr (&mcnt, &p);
728 printf ("/jump to %d", p + mcnt - start);
732 extract_number_and_incr (&mcnt, &p);
733 extract_number_and_incr (&mcnt2, &p);
734 printf ("/succeed_n to %d, %d times", p + mcnt - start, mcnt2);
738 extract_number_and_incr (&mcnt, &p);
739 extract_number_and_incr (&mcnt2, &p);
740 printf ("/jump_n to %d, %d times", p + mcnt - start, mcnt2);
744 extract_number_and_incr (&mcnt, &p);
745 extract_number_and_incr (&mcnt2, &p);
746 printf ("/set_number_at location %d to %d", p + mcnt - start, mcnt2);
750 printf ("/wordbound");
754 printf ("/notwordbound");
766 printf ("/before_dot");
774 printf ("/after_dot");
778 printf ("/syntaxspec");
780 printf ("/%d", mcnt);
784 printf ("/notsyntaxspec");
786 printf ("/%d", mcnt);
791 printf ("/wordchar");
795 printf ("/notwordchar");
807 printf ("?%d", *(p-1));
813 printf ("%d:\tend of pattern.\n", p - start);
818 print_compiled_pattern (bufp)
819 struct re_pattern_buffer *bufp;
821 unsigned char *buffer = bufp->buffer;
823 print_partial_compiled_pattern (buffer, buffer + bufp->used);
824 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
826 if (bufp->fastmap_accurate && bufp->fastmap)
828 printf ("fastmap: ");
829 print_fastmap (bufp->fastmap);
832 printf ("re_nsub: %d\t", bufp->re_nsub);
833 printf ("regs_alloc: %d\t", bufp->regs_allocated);
834 printf ("can_be_null: %d\t", bufp->can_be_null);
835 printf ("newline_anchor: %d\n", bufp->newline_anchor);
836 printf ("no_sub: %d\t", bufp->no_sub);
837 printf ("not_bol: %d\t", bufp->not_bol);
838 printf ("not_eol: %d\t", bufp->not_eol);
839 printf ("syntax: %d\n", bufp->syntax);
840 /* Perhaps we should print the translate table? */
845 print_double_string (where, string1, size1, string2, size2)
858 if (FIRST_STRING_P (where))
860 for (this_char = where - string1; this_char < size1; this_char++)
861 putchar (string1[this_char]);
866 for (this_char = where - string2; this_char < size2; this_char++)
867 putchar (string2[this_char]);
871 #else /* not DEBUG */
876 #define DEBUG_STATEMENT(e)
877 #define DEBUG_PRINT1(x)
878 #define DEBUG_PRINT2(x1, x2)
879 #define DEBUG_PRINT3(x1, x2, x3)
880 #define DEBUG_PRINT4(x1, x2, x3, x4)
881 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
882 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
884 #endif /* not DEBUG */
886 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
887 also be assigned to arbitrarily: each pattern buffer stores its own
888 syntax, so it can be changed between regex compilations. */
889 /* This has no initializer because initialized variables in Emacs
890 become read-only after dumping. */
891 reg_syntax_t re_syntax_options;
894 /* Specify the precise syntax of regexps for compilation. This provides
895 for compatibility for various utilities which historically have
896 different, incompatible syntaxes.
898 The argument SYNTAX is a bit mask comprised of the various bits
899 defined in regex.h. We return the old syntax. */
902 re_set_syntax (syntax)
905 reg_syntax_t ret = re_syntax_options;
907 re_syntax_options = syntax;
911 /* This table gives an error message for each of the error codes listed
912 in regex.h. Obviously the order here has to be same as there.
913 POSIX doesn't require that we do anything for REG_NOERROR,
914 but why not be nice? */
916 static const char *re_error_msgid[] =
917 { "Success", /* REG_NOERROR */
918 "No match", /* REG_NOMATCH */
919 "Invalid regular expression", /* REG_BADPAT */
920 "Invalid collation character", /* REG_ECOLLATE */
921 "Invalid character class name", /* REG_ECTYPE */
922 "Trailing backslash", /* REG_EESCAPE */
923 "Invalid back reference", /* REG_ESUBREG */
924 "Unmatched [ or [^", /* REG_EBRACK */
925 "Unmatched ( or \\(", /* REG_EPAREN */
926 "Unmatched \\{", /* REG_EBRACE */
927 "Invalid content of \\{\\}", /* REG_BADBR */
928 "Invalid range end", /* REG_ERANGE */
929 "Memory exhausted", /* REG_ESPACE */
930 "Invalid preceding regular expression", /* REG_BADRPT */
931 "Premature end of regular expression", /* REG_EEND */
932 "Regular expression too big", /* REG_ESIZE */
933 "Unmatched ) or \\)", /* REG_ERPAREN */
936 /* Avoiding alloca during matching, to placate r_alloc. */
938 /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
939 searching and matching functions should not call alloca. On some
940 systems, alloca is implemented in terms of malloc, and if we're
941 using the relocating allocator routines, then malloc could cause a
942 relocation, which might (if the strings being searched are in the
943 ralloc heap) shift the data out from underneath the regexp
946 Here's another reason to avoid allocation: Emacs
947 processes input from X in a signal handler; processing X input may
948 call malloc; if input arrives while a matching routine is calling
949 malloc, then we're scrod. But Emacs can't just block input while
950 calling matching routines; then we don't notice interrupts when
951 they come in. So, Emacs blocks input around all regexp calls
952 except the matching calls, which it leaves unprotected, in the
953 faith that they will not malloc. */
955 /* Normally, this is fine. */
956 #define MATCH_MAY_ALLOCATE
958 /* When using GNU C, we are not REALLY using the C alloca, no matter
959 what config.h may say. So don't take precautions for it. */
964 /* The match routines may not allocate if (1) they would do it with malloc
965 and (2) it's not safe for them to use malloc. */
966 #if (defined (C_ALLOCA) || defined (REGEX_MALLOC)) && (defined (emacs) || defined (REL_ALLOC))
967 #undef MATCH_MAY_ALLOCATE
971 /* Failure stack declarations and macros; both re_compile_fastmap and
972 re_match_2 use a failure stack. These have to be macros because of
973 REGEX_ALLOCATE_STACK. */
976 /* Number of failure points for which to initially allocate space
977 when matching. If this number is exceeded, we allocate more
978 space, so it is not a hard limit. */
979 #ifndef INIT_FAILURE_ALLOC
980 #define INIT_FAILURE_ALLOC 5
983 /* Roughly the maximum number of failure points on the stack. Would be
984 exactly that if always used MAX_FAILURE_SPACE each time we failed.
985 This is a variable only so users of regex can assign to it; we never
986 change it ourselves. */
988 int re_max_failures = 20000000;
990 int re_max_failures = 2000;
993 typedef unsigned char *fail_stack_elt_t;
997 fail_stack_elt_t *stack;
999 unsigned avail; /* Offset of next open position. */
1002 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
1003 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
1004 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
1005 #define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail])
1008 /* Initialize `fail_stack'. Do `return -2' if the alloc fails. */
1010 #ifdef MATCH_MAY_ALLOCATE
1011 #define INIT_FAIL_STACK() \
1013 fail_stack.stack = (fail_stack_elt_t *) \
1014 REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
1016 if (fail_stack.stack == NULL) \
1019 fail_stack.size = INIT_FAILURE_ALLOC; \
1020 fail_stack.avail = 0; \
1023 #define INIT_FAIL_STACK() \
1025 fail_stack.avail = 0; \
1030 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
1032 Return 1 if succeeds, and 0 if either ran out of memory
1033 allocating space for it or it was already too large.
1035 REGEX_REALLOCATE_STACK requires `destination' be declared. */
1037 #define DOUBLE_FAIL_STACK(fail_stack) \
1038 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
1040 : ((fail_stack).stack = (fail_stack_elt_t *) \
1041 REGEX_REALLOCATE_STACK ((fail_stack).stack, \
1042 (fail_stack).size * sizeof (fail_stack_elt_t), \
1043 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
1045 (fail_stack).stack == NULL \
1047 : ((fail_stack).size <<= 1, \
1051 /* Push PATTERN_OP on FAIL_STACK.
1053 Return 1 if was able to do so and 0 if ran out of memory allocating
1055 #define PUSH_PATTERN_OP(pattern_op, fail_stack) \
1056 ((FAIL_STACK_FULL () \
1057 && !DOUBLE_FAIL_STACK (fail_stack)) \
1059 : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \
1062 /* Push a pointer value onto the failure stack.
1063 Assumes the variable `fail_stack'. Probably should only
1064 be called from within `PUSH_FAILURE_POINT'. */
1065 #define PUSH_FAILURE_POINTER(item) \
1066 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) (item)
1068 /* This pushes an integer-valued item onto the failure stack.
1069 Assumes the variable `fail_stack'. Probably should only
1070 be called from within `PUSH_FAILURE_POINT'. */
1071 #define PUSH_FAILURE_INT(item) \
1072 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) (WIDE_INT) (item)
1074 /* The complement operation. Assumes `fail_stack' is nonempty. */
1075 #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail]
1077 /* The complement operation. Assumes `fail_stack' is nonempty. */
1078 #define POP_FAILURE_INT() (WIDE_INT) fail_stack.stack[--fail_stack.avail]
1080 /* Used to omit pushing failure point id's when we're not debugging. */
1082 #define DEBUG_PUSH PUSH_FAILURE_INT
1083 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT ()
1085 #define DEBUG_PUSH(item)
1086 #define DEBUG_POP(item_addr)
1090 /* Push the information about the state we will need
1091 if we ever fail back to it.
1093 Requires variables fail_stack, regstart, regend, reg_info, and
1094 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
1097 Does `return FAILURE_CODE' if runs out of memory. */
1099 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1101 char *destination; \
1102 /* Must be int, so when we don't save any registers, the arithmetic \
1103 of 0 + -1 isn't done as unsigned. */ \
1106 DEBUG_STATEMENT (failure_id++); \
1107 DEBUG_STATEMENT (nfailure_points_pushed++); \
1108 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1109 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1110 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1112 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
1113 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1115 /* Ensure we have enough space allocated for what we will push. */ \
1116 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1118 if (!DOUBLE_FAIL_STACK (fail_stack)) \
1119 return failure_code; \
1121 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1122 (fail_stack).size); \
1123 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1126 /* Push the info, starting with the registers. */ \
1127 DEBUG_PRINT1 ("\n"); \
1129 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
1132 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
1133 DEBUG_STATEMENT (num_regs_pushed++); \
1135 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1136 PUSH_FAILURE_POINTER (regstart[this_reg]); \
1138 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1139 PUSH_FAILURE_POINTER (regend[this_reg]); \
1141 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
1142 DEBUG_PRINT2 (" match_null=%d", \
1143 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1144 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1145 DEBUG_PRINT2 (" matched_something=%d", \
1146 MATCHED_SOMETHING (reg_info[this_reg])); \
1147 DEBUG_PRINT2 (" ever_matched=%d", \
1148 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1149 DEBUG_PRINT1 ("\n"); \
1150 PUSH_FAILURE_POINTER (reg_info[this_reg].word); \
1153 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
1154 PUSH_FAILURE_INT (lowest_active_reg); \
1156 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
1157 PUSH_FAILURE_INT (highest_active_reg); \
1159 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
1160 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1161 PUSH_FAILURE_POINTER (pattern_place); \
1163 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
1164 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1166 DEBUG_PRINT1 ("'\n"); \
1167 PUSH_FAILURE_POINTER (string_place); \
1169 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1170 DEBUG_PUSH (failure_id); \
1173 /* This is the number of items that are pushed and popped on the stack
1174 for each register. */
1175 #define NUM_REG_ITEMS 3
1177 /* Individual items aside from the registers. */
1179 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1181 #define NUM_NONREG_ITEMS 4
1184 /* We push at most this many items on the stack. */
1185 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1187 /* We actually push this many items. */
1188 #define NUM_FAILURE_ITEMS \
1189 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
1192 /* How many items can still be added to the stack without overflowing it. */
1193 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1196 /* Pops what PUSH_FAIL_STACK pushes.
1198 We restore into the parameters, all of which should be lvalues:
1199 STR -- the saved data position.
1200 PAT -- the saved pattern position.
1201 LOW_REG, HIGH_REG -- the highest and lowest active registers.
1202 REGSTART, REGEND -- arrays of string positions.
1203 REG_INFO -- array of information about each subexpression.
1205 Also assumes the variables `fail_stack' and (if debugging), `bufp',
1206 `pend', `string1', `size1', `string2', and `size2'. */
1208 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1210 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
1212 const unsigned char *string_temp; \
1214 assert (!FAIL_STACK_EMPTY ()); \
1216 /* Remove failure points and point to how many regs pushed. */ \
1217 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1218 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1219 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1221 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1223 DEBUG_POP (&failure_id); \
1224 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1226 /* If the saved string location is NULL, it came from an \
1227 on_failure_keep_string_jump opcode, and we want to throw away the \
1228 saved NULL, thus retaining our current position in the string. */ \
1229 string_temp = POP_FAILURE_POINTER (); \
1230 if (string_temp != NULL) \
1231 str = (const char *) string_temp; \
1233 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
1234 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1235 DEBUG_PRINT1 ("'\n"); \
1237 pat = (unsigned char *) POP_FAILURE_POINTER (); \
1238 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
1239 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1241 /* Restore register info. */ \
1242 high_reg = (unsigned) POP_FAILURE_INT (); \
1243 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
1245 low_reg = (unsigned) POP_FAILURE_INT (); \
1246 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
1248 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
1250 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
1252 reg_info[this_reg].word = POP_FAILURE_POINTER (); \
1253 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
1255 regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1256 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1258 regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \
1259 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1262 set_regs_matched_done = 0; \
1263 DEBUG_STATEMENT (nfailure_points_popped++); \
1264 } /* POP_FAILURE_POINT */
1268 /* Structure for per-register (a.k.a. per-group) information.
1269 This must not be longer than one word, because we push this value
1270 onto the failure stack. Other register information, such as the
1271 starting and ending positions (which are addresses), and the list of
1272 inner groups (which is a bits list) are maintained in separate
1275 We are making a (strictly speaking) nonportable assumption here: that
1276 the compiler will pack our bit fields into something that fits into
1277 the type of `word', i.e., is something that fits into one item on the
1281 fail_stack_elt_t word;
1284 /* This field is one if this group can match the empty string,
1285 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1286 #define MATCH_NULL_UNSET_VALUE 3
1287 unsigned match_null_string_p : 2;
1288 unsigned is_active : 1;
1289 unsigned matched_something : 1;
1290 unsigned ever_matched_something : 1;
1292 } register_info_type;
1294 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1295 #define IS_ACTIVE(R) ((R).bits.is_active)
1296 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1297 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1300 /* Call this when have matched a real character; it sets `matched' flags
1301 for the subexpressions which we are currently inside. Also records
1302 that those subexprs have matched. */
1303 #define SET_REGS_MATCHED() \
1306 if (!set_regs_matched_done) \
1309 set_regs_matched_done = 1; \
1310 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1312 MATCHED_SOMETHING (reg_info[r]) \
1313 = EVER_MATCHED_SOMETHING (reg_info[r]) \
1320 /* Registers are set to a sentinel when they haven't yet matched. */
1321 static char reg_unset_dummy;
1322 #define REG_UNSET_VALUE (®_unset_dummy)
1323 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1325 /* Subroutine declarations and macros for regex_compile. */
1327 static void store_op1 (), store_op2 ();
1328 static void insert_op1 (), insert_op2 ();
1329 static boolean at_begline_loc_p (), at_endline_loc_p ();
1330 static boolean group_in_compile_stack ();
1331 static reg_errcode_t compile_range ();
1333 /* Fetch the next character in the uncompiled pattern---translating it
1334 if necessary. Also cast from a signed character in the constant
1335 string passed to us by the user to an unsigned char that we can use
1336 as an array index (in, e.g., `translate'). */
1337 #define PATFETCH(c) \
1338 do {if (p == pend) return REG_EEND; \
1339 c = (unsigned char) *p++; \
1340 if (translate) c = translate[c]; \
1343 /* Fetch the next character in the uncompiled pattern, with no
1345 #define PATFETCH_RAW(c) \
1346 do {if (p == pend) return REG_EEND; \
1347 c = (unsigned char) *p++; \
1350 /* Go backwards one character in the pattern. */
1351 #define PATUNFETCH p--
1354 /* If `translate' is non-null, return translate[D], else just D. We
1355 cast the subscript to translate because some data is declared as
1356 `char *', to avoid warnings when a string constant is passed. But
1357 when we use a character as a subscript we must make it unsigned. */
1358 #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
1361 /* Macros for outputting the compiled pattern into `buffer'. */
1363 /* If the buffer isn't allocated when it comes in, use this. */
1364 #define INIT_BUF_SIZE 32
1366 /* Make sure we have at least N more bytes of space in buffer. */
1367 #define GET_BUFFER_SPACE(n) \
1368 while (b - bufp->buffer + (n) > bufp->allocated) \
1371 /* Make sure we have one more byte of buffer space and then add C to it. */
1372 #define BUF_PUSH(c) \
1374 GET_BUFFER_SPACE (1); \
1375 *b++ = (unsigned char) (c); \
1379 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1380 #define BUF_PUSH_2(c1, c2) \
1382 GET_BUFFER_SPACE (2); \
1383 *b++ = (unsigned char) (c1); \
1384 *b++ = (unsigned char) (c2); \
1388 /* As with BUF_PUSH_2, except for three bytes. */
1389 #define BUF_PUSH_3(c1, c2, c3) \
1391 GET_BUFFER_SPACE (3); \
1392 *b++ = (unsigned char) (c1); \
1393 *b++ = (unsigned char) (c2); \
1394 *b++ = (unsigned char) (c3); \
1398 /* Store a jump with opcode OP at LOC to location TO. We store a
1399 relative address offset by the three bytes the jump itself occupies. */
1400 #define STORE_JUMP(op, loc, to) \
1401 store_op1 (op, loc, (to) - (loc) - 3)
1403 /* Likewise, for a two-argument jump. */
1404 #define STORE_JUMP2(op, loc, to, arg) \
1405 store_op2 (op, loc, (to) - (loc) - 3, arg)
1407 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1408 #define INSERT_JUMP(op, loc, to) \
1409 insert_op1 (op, loc, (to) - (loc) - 3, b)
1411 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1412 #define INSERT_JUMP2(op, loc, to, arg) \
1413 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
1416 /* This is not an arbitrary limit: the arguments which represent offsets
1417 into the pattern are two bytes long. So if 2^16 bytes turns out to
1418 be too small, many things would have to change. */
1419 #define MAX_BUF_SIZE (1L << 16)
1422 /* Extend the buffer by twice its current size via realloc and
1423 reset the pointers that pointed into the old block to point to the
1424 correct places in the new one. If extending the buffer results in it
1425 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1426 #define EXTEND_BUFFER() \
1428 unsigned char *old_buffer = bufp->buffer; \
1429 if (bufp->allocated == MAX_BUF_SIZE) \
1431 bufp->allocated <<= 1; \
1432 if (bufp->allocated > MAX_BUF_SIZE) \
1433 bufp->allocated = MAX_BUF_SIZE; \
1434 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
1435 if (bufp->buffer == NULL) \
1436 return REG_ESPACE; \
1437 /* If the buffer moved, move all the pointers into it. */ \
1438 if (old_buffer != bufp->buffer) \
1440 b = (b - old_buffer) + bufp->buffer; \
1441 begalt = (begalt - old_buffer) + bufp->buffer; \
1442 if (fixup_alt_jump) \
1443 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1445 laststart = (laststart - old_buffer) + bufp->buffer; \
1446 if (pending_exact) \
1447 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1452 /* Since we have one byte reserved for the register number argument to
1453 {start,stop}_memory, the maximum number of groups we can report
1454 things about is what fits in that byte. */
1455 #define MAX_REGNUM 255
1457 /* But patterns can have more than `MAX_REGNUM' registers. We just
1458 ignore the excess. */
1459 typedef unsigned regnum_t;
1462 /* Macros for the compile stack. */
1464 /* Since offsets can go either forwards or backwards, this type needs to
1465 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1466 typedef int pattern_offset_t;
1470 pattern_offset_t begalt_offset;
1471 pattern_offset_t fixup_alt_jump;
1472 pattern_offset_t inner_group_offset;
1473 pattern_offset_t laststart_offset;
1475 } compile_stack_elt_t;
1480 compile_stack_elt_t *stack;
1482 unsigned avail; /* Offset of next open position. */
1483 } compile_stack_type;
1486 #define INIT_COMPILE_STACK_SIZE 32
1488 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1489 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1491 /* The next available element. */
1492 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1495 /* Set the bit for character C in a list. */
1496 #define SET_LIST_BIT(c) \
1497 (b[((unsigned char) (c)) / BYTEWIDTH] \
1498 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1501 /* Get the next unsigned number in the uncompiled pattern. */
1502 #define GET_UNSIGNED_NUMBER(num) \
1506 while (ISDIGIT (c)) \
1510 num = num * 10 + c - '0'; \
1518 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1520 #define IS_CHAR_CLASS(string) \
1521 (STREQ (string, "alpha") || STREQ (string, "upper") \
1522 || STREQ (string, "lower") || STREQ (string, "digit") \
1523 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1524 || STREQ (string, "space") || STREQ (string, "print") \
1525 || STREQ (string, "punct") || STREQ (string, "graph") \
1526 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1528 #ifndef MATCH_MAY_ALLOCATE
1530 /* If we cannot allocate large objects within re_match_2_internal,
1531 we make the fail stack and register vectors global.
1532 The fail stack, we grow to the maximum size when a regexp
1534 The register vectors, we adjust in size each time we
1535 compile a regexp, according to the number of registers it needs. */
1537 static fail_stack_type fail_stack;
1539 /* Size with which the following vectors are currently allocated.
1540 That is so we can make them bigger as needed,
1541 but never make them smaller. */
1542 static int regs_allocated_size;
1544 static const char ** regstart, ** regend;
1545 static const char ** old_regstart, ** old_regend;
1546 static const char **best_regstart, **best_regend;
1547 static register_info_type *reg_info;
1548 static const char **reg_dummy;
1549 static register_info_type *reg_info_dummy;
1551 /* Make the register vectors big enough for NUM_REGS registers,
1552 but don't make them smaller. */
1555 regex_grow_registers (num_regs)
1558 if (num_regs > regs_allocated_size)
1560 RETALLOC_IF (regstart, num_regs, const char *);
1561 RETALLOC_IF (regend, num_regs, const char *);
1562 RETALLOC_IF (old_regstart, num_regs, const char *);
1563 RETALLOC_IF (old_regend, num_regs, const char *);
1564 RETALLOC_IF (best_regstart, num_regs, const char *);
1565 RETALLOC_IF (best_regend, num_regs, const char *);
1566 RETALLOC_IF (reg_info, num_regs, register_info_type);
1567 RETALLOC_IF (reg_dummy, num_regs, const char *);
1568 RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
1570 regs_allocated_size = num_regs;
1574 #endif /* not MATCH_MAY_ALLOCATE */
1576 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1577 Returns one of error codes defined in `regex.h', or zero for success.
1579 Assumes the `allocated' (and perhaps `buffer') and `translate'
1580 fields are set in BUFP on entry.
1582 If it succeeds, results are put in BUFP (if it returns an error, the
1583 contents of BUFP are undefined):
1584 `buffer' is the compiled pattern;
1585 `syntax' is set to SYNTAX;
1586 `used' is set to the length of the compiled pattern;
1587 `fastmap_accurate' is zero;
1588 `re_nsub' is the number of subexpressions in PATTERN;
1589 `not_bol' and `not_eol' are zero;
1591 The `fastmap' and `newline_anchor' fields are neither
1592 examined nor set. */
1594 /* Return, freeing storage we allocated. */
1595 #define FREE_STACK_RETURN(value) \
1596 return (free (compile_stack.stack), value)
1598 static reg_errcode_t
1599 regex_compile (pattern, size, syntax, bufp)
1600 const char *pattern;
1602 reg_syntax_t syntax;
1603 struct re_pattern_buffer *bufp;
1605 /* We fetch characters from PATTERN here. Even though PATTERN is
1606 `char *' (i.e., signed), we declare these variables as unsigned, so
1607 they can be reliably used as array indices. */
1608 register unsigned char c, c1;
1610 /* A random temporary spot in PATTERN. */
1613 /* Points to the end of the buffer, where we should append. */
1614 register unsigned char *b;
1616 /* Keeps track of unclosed groups. */
1617 compile_stack_type compile_stack;
1619 /* Points to the current (ending) position in the pattern. */
1620 const char *p = pattern;
1621 const char *pend = pattern + size;
1623 /* How to translate the characters in the pattern. */
1624 char *translate = bufp->translate;
1626 /* Address of the count-byte of the most recently inserted `exactn'
1627 command. This makes it possible to tell if a new exact-match
1628 character can be added to that command or if the character requires
1629 a new `exactn' command. */
1630 unsigned char *pending_exact = 0;
1632 /* Address of start of the most recently finished expression.
1633 This tells, e.g., postfix * where to find the start of its
1634 operand. Reset at the beginning of groups and alternatives. */
1635 unsigned char *laststart = 0;
1637 /* Address of beginning of regexp, or inside of last group. */
1638 unsigned char *begalt;
1640 /* Place in the uncompiled pattern (i.e., the {) to
1641 which to go back if the interval is invalid. */
1642 const char *beg_interval;
1644 /* Address of the place where a forward jump should go to the end of
1645 the containing expression. Each alternative of an `or' -- except the
1646 last -- ends with a forward jump of this sort. */
1647 unsigned char *fixup_alt_jump = 0;
1649 /* Counts open-groups as they are encountered. Remembered for the
1650 matching close-group on the compile stack, so the same register
1651 number is put in the stop_memory as the start_memory. */
1652 regnum_t regnum = 0;
1655 DEBUG_PRINT1 ("\nCompiling pattern: ");
1658 unsigned debug_count;
1660 for (debug_count = 0; debug_count < size; debug_count++)
1661 putchar (pattern[debug_count]);
1666 /* Initialize the compile stack. */
1667 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1668 if (compile_stack.stack == NULL)
1671 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1672 compile_stack.avail = 0;
1674 /* Initialize the pattern buffer. */
1675 bufp->syntax = syntax;
1676 bufp->fastmap_accurate = 0;
1677 bufp->not_bol = bufp->not_eol = 0;
1679 /* Set `used' to zero, so that if we return an error, the pattern
1680 printer (for debugging) will think there's no pattern. We reset it
1684 /* Always count groups, whether or not bufp->no_sub is set. */
1687 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1688 /* Initialize the syntax table. */
1689 init_syntax_once ();
1692 if (bufp->allocated == 0)
1695 { /* If zero allocated, but buffer is non-null, try to realloc
1696 enough space. This loses if buffer's address is bogus, but
1697 that is the user's responsibility. */
1698 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1701 { /* Caller did not allocate a buffer. Do it for them. */
1702 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1704 if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
1706 bufp->allocated = INIT_BUF_SIZE;
1709 begalt = b = bufp->buffer;
1711 /* Loop through the uncompiled pattern until we're at the end. */
1720 if ( /* If at start of pattern, it's an operator. */
1722 /* If context independent, it's an operator. */
1723 || syntax & RE_CONTEXT_INDEP_ANCHORS
1724 /* Otherwise, depends on what's come before. */
1725 || at_begline_loc_p (pattern, p, syntax))
1735 if ( /* If at end of pattern, it's an operator. */
1737 /* If context independent, it's an operator. */
1738 || syntax & RE_CONTEXT_INDEP_ANCHORS
1739 /* Otherwise, depends on what's next. */
1740 || at_endline_loc_p (p, pend, syntax))
1750 if ((syntax & RE_BK_PLUS_QM)
1751 || (syntax & RE_LIMITED_OPS))
1755 /* If there is no previous pattern... */
1758 if (syntax & RE_CONTEXT_INVALID_OPS)
1759 FREE_STACK_RETURN (REG_BADRPT);
1760 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1765 /* Are we optimizing this jump? */
1766 boolean keep_string_p = false;
1768 /* 1 means zero (many) matches is allowed. */
1769 char zero_times_ok = 0, many_times_ok = 0;
1771 /* If there is a sequence of repetition chars, collapse it
1772 down to just one (the right one). We can't combine
1773 interval operators with these because of, e.g., `a{2}*',
1774 which should only match an even number of `a's. */
1778 zero_times_ok |= c != '+';
1779 many_times_ok |= c != '?';
1787 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1790 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1792 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1795 if (!(c1 == '+' || c1 == '?'))
1810 /* If we get here, we found another repeat character. */
1813 /* Star, etc. applied to an empty pattern is equivalent
1814 to an empty pattern. */
1818 /* Now we know whether or not zero matches is allowed
1819 and also whether or not two or more matches is allowed. */
1821 { /* More than one repetition is allowed, so put in at the
1822 end a backward relative jump from `b' to before the next
1823 jump we're going to put in below (which jumps from
1824 laststart to after this jump).
1826 But if we are at the `*' in the exact sequence `.*\n',
1827 insert an unconditional jump backwards to the .,
1828 instead of the beginning of the loop. This way we only
1829 push a failure point once, instead of every time
1830 through the loop. */
1831 assert (p - 1 > pattern);
1833 /* Allocate the space for the jump. */
1834 GET_BUFFER_SPACE (3);
1836 /* We know we are not at the first character of the pattern,
1837 because laststart was nonzero. And we've already
1838 incremented `p', by the way, to be the character after
1839 the `*'. Do we have to do something analogous here
1840 for null bytes, because of RE_DOT_NOT_NULL? */
1841 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1843 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1844 && !(syntax & RE_DOT_NEWLINE))
1845 { /* We have .*\n. */
1846 STORE_JUMP (jump, b, laststart);
1847 keep_string_p = true;
1850 /* Anything else. */
1851 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1853 /* We've added more stuff to the buffer. */
1857 /* On failure, jump from laststart to b + 3, which will be the
1858 end of the buffer after this jump is inserted. */
1859 GET_BUFFER_SPACE (3);
1860 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1868 /* At least one repetition is required, so insert a
1869 `dummy_failure_jump' before the initial
1870 `on_failure_jump' instruction of the loop. This
1871 effects a skip over that instruction the first time
1872 we hit that loop. */
1873 GET_BUFFER_SPACE (3);
1874 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1889 boolean had_char_class = false;
1891 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
1893 /* Ensure that we have enough space to push a charset: the
1894 opcode, the length count, and the bitset; 34 bytes in all. */
1895 GET_BUFFER_SPACE (34);
1899 /* We test `*p == '^' twice, instead of using an if
1900 statement, so we only need one BUF_PUSH. */
1901 BUF_PUSH (*p == '^' ? charset_not : charset);
1905 /* Remember the first position in the bracket expression. */
1908 /* Push the number of bytes in the bitmap. */
1909 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1911 /* Clear the whole map. */
1912 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1914 /* charset_not matches newline according to a syntax bit. */
1915 if ((re_opcode_t) b[-2] == charset_not
1916 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1917 SET_LIST_BIT ('\n');
1919 /* Read in characters and ranges, setting map bits. */
1922 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
1926 /* \ might escape characters inside [...] and [^...]. */
1927 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1929 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
1936 /* Could be the end of the bracket expression. If it's
1937 not (i.e., when the bracket expression is `[]' so
1938 far), the ']' character bit gets set way below. */
1939 if (c == ']' && p != p1 + 1)
1942 /* Look ahead to see if it's a range when the last thing
1943 was a character class. */
1944 if (had_char_class && c == '-' && *p != ']')
1945 FREE_STACK_RETURN (REG_ERANGE);
1947 /* Look ahead to see if it's a range when the last thing
1948 was a character: if this is a hyphen not at the
1949 beginning or the end of a list, then it's the range
1952 && !(p - 2 >= pattern && p[-2] == '[')
1953 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1957 = compile_range (&p, pend, translate, syntax, b);
1958 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
1961 else if (p[0] == '-' && p[1] != ']')
1962 { /* This handles ranges made up of characters only. */
1965 /* Move past the `-'. */
1968 ret = compile_range (&p, pend, translate, syntax, b);
1969 if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
1972 /* See if we're at the beginning of a possible character
1975 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1976 { /* Leave room for the null. */
1977 char str[CHAR_CLASS_MAX_LENGTH + 1];
1982 /* If pattern is `[[:'. */
1983 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
1988 if (c == ':' || c == ']' || p == pend
1989 || c1 == CHAR_CLASS_MAX_LENGTH)
1995 /* If isn't a word bracketed by `[:' and:`]':
1996 undo the ending character, the letters, and leave
1997 the leading `:' and `[' (but set bits for them). */
1998 if (c == ':' && *p == ']')
2001 boolean is_alnum = STREQ (str, "alnum");
2002 boolean is_alpha = STREQ (str, "alpha");
2003 boolean is_blank = STREQ (str, "blank");
2004 boolean is_cntrl = STREQ (str, "cntrl");
2005 boolean is_digit = STREQ (str, "digit");
2006 boolean is_graph = STREQ (str, "graph");
2007 boolean is_lower = STREQ (str, "lower");
2008 boolean is_print = STREQ (str, "print");
2009 boolean is_punct = STREQ (str, "punct");
2010 boolean is_space = STREQ (str, "space");
2011 boolean is_upper = STREQ (str, "upper");
2012 boolean is_xdigit = STREQ (str, "xdigit");
2014 if (!IS_CHAR_CLASS (str))
2015 FREE_STACK_RETURN (REG_ECTYPE);
2017 /* Throw away the ] at the end of the character
2021 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
2023 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
2025 /* This was split into 3 if's to
2026 avoid an arbitrary limit in some compiler. */
2027 if ( (is_alnum && ISALNUM (ch))
2028 || (is_alpha && ISALPHA (ch))
2029 || (is_blank && ISBLANK (ch))
2030 || (is_cntrl && ISCNTRL (ch)))
2032 if ( (is_digit && ISDIGIT (ch))
2033 || (is_graph && ISGRAPH (ch))
2034 || (is_lower && ISLOWER (ch))
2035 || (is_print && ISPRINT (ch)))
2037 if ( (is_punct && ISPUNCT (ch))
2038 || (is_space && ISSPACE (ch))
2039 || (is_upper && ISUPPER (ch))
2040 || (is_xdigit && ISXDIGIT (ch)))
2043 had_char_class = true;
2052 had_char_class = false;
2057 had_char_class = false;
2062 /* Discard any (non)matching list bytes that are all 0 at the
2063 end of the map. Decrease the map-length byte too. */
2064 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
2072 if (syntax & RE_NO_BK_PARENS)
2079 if (syntax & RE_NO_BK_PARENS)
2086 if (syntax & RE_NEWLINE_ALT)
2093 if (syntax & RE_NO_BK_VBAR)
2100 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
2101 goto handle_interval;
2107 if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
2109 /* Do not translate the character after the \, so that we can
2110 distinguish, e.g., \B from \b, even if we normally would
2111 translate, e.g., B to b. */
2117 if (syntax & RE_NO_BK_PARENS)
2118 goto normal_backslash;
2124 if (COMPILE_STACK_FULL)
2126 RETALLOC (compile_stack.stack, compile_stack.size << 1,
2127 compile_stack_elt_t);
2128 if (compile_stack.stack == NULL) return REG_ESPACE;
2130 compile_stack.size <<= 1;
2133 /* These are the values to restore when we hit end of this
2134 group. They are all relative offsets, so that if the
2135 whole pattern moves because of realloc, they will still
2137 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2138 COMPILE_STACK_TOP.fixup_alt_jump
2139 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2140 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2141 COMPILE_STACK_TOP.regnum = regnum;
2143 /* We will eventually replace the 0 with the number of
2144 groups inner to this one. But do not push a
2145 start_memory for groups beyond the last one we can
2146 represent in the compiled pattern. */
2147 if (regnum <= MAX_REGNUM)
2149 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2150 BUF_PUSH_3 (start_memory, regnum, 0);
2153 compile_stack.avail++;
2158 /* If we've reached MAX_REGNUM groups, then this open
2159 won't actually generate any code, so we'll have to
2160 clear pending_exact explicitly. */
2166 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
2168 if (COMPILE_STACK_EMPTY)
2169 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2170 goto normal_backslash;
2172 FREE_STACK_RETURN (REG_ERPAREN);
2176 { /* Push a dummy failure point at the end of the
2177 alternative for a possible future
2178 `pop_failure_jump' to pop. See comments at
2179 `push_dummy_failure' in `re_match_2'. */
2180 BUF_PUSH (push_dummy_failure);
2182 /* We allocated space for this jump when we assigned
2183 to `fixup_alt_jump', in the `handle_alt' case below. */
2184 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2187 /* See similar code for backslashed left paren above. */
2188 if (COMPILE_STACK_EMPTY)
2189 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2192 FREE_STACK_RETURN (REG_ERPAREN);
2194 /* Since we just checked for an empty stack above, this
2195 ``can't happen''. */
2196 assert (compile_stack.avail != 0);
2198 /* We don't just want to restore into `regnum', because
2199 later groups should continue to be numbered higher,
2200 as in `(ab)c(de)' -- the second group is #2. */
2201 regnum_t this_group_regnum;
2203 compile_stack.avail--;
2204 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2206 = COMPILE_STACK_TOP.fixup_alt_jump
2207 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
2209 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2210 this_group_regnum = COMPILE_STACK_TOP.regnum;
2211 /* If we've reached MAX_REGNUM groups, then this open
2212 won't actually generate any code, so we'll have to
2213 clear pending_exact explicitly. */
2216 /* We're at the end of the group, so now we know how many
2217 groups were inside this one. */
2218 if (this_group_regnum <= MAX_REGNUM)
2220 unsigned char *inner_group_loc
2221 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2223 *inner_group_loc = regnum - this_group_regnum;
2224 BUF_PUSH_3 (stop_memory, this_group_regnum,
2225 regnum - this_group_regnum);
2231 case '|': /* `\|'. */
2232 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
2233 goto normal_backslash;
2235 if (syntax & RE_LIMITED_OPS)
2238 /* Insert before the previous alternative a jump which
2239 jumps to this alternative if the former fails. */
2240 GET_BUFFER_SPACE (3);
2241 INSERT_JUMP (on_failure_jump, begalt, b + 6);
2245 /* The alternative before this one has a jump after it
2246 which gets executed if it gets matched. Adjust that
2247 jump so it will jump to this alternative's analogous
2248 jump (put in below, which in turn will jump to the next
2249 (if any) alternative's such jump, etc.). The last such
2250 jump jumps to the correct final destination. A picture:
2256 If we are at `b', then fixup_alt_jump right now points to a
2257 three-byte space after `a'. We'll put in the jump, set
2258 fixup_alt_jump to right after `b', and leave behind three
2259 bytes which we'll fill in when we get to after `c'. */
2262 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2264 /* Mark and leave space for a jump after this alternative,
2265 to be filled in later either by next alternative or
2266 when know we're at the end of a series of alternatives. */
2268 GET_BUFFER_SPACE (3);
2277 /* If \{ is a literal. */
2278 if (!(syntax & RE_INTERVALS)
2279 /* If we're at `\{' and it's not the open-interval
2281 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2282 || (p - 2 == pattern && p == pend))
2283 goto normal_backslash;
2287 /* If got here, then the syntax allows intervals. */
2289 /* At least (most) this many matches must be made. */
2290 int lower_bound = -1, upper_bound = -1;
2292 beg_interval = p - 1;
2296 if (syntax & RE_NO_BK_BRACES)
2297 goto unfetch_interval;
2299 FREE_STACK_RETURN (REG_EBRACE);
2302 GET_UNSIGNED_NUMBER (lower_bound);
2306 GET_UNSIGNED_NUMBER (upper_bound);
2307 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
2310 /* Interval such as `{1}' => match exactly once. */
2311 upper_bound = lower_bound;
2313 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
2314 || lower_bound > upper_bound)
2316 if (syntax & RE_NO_BK_BRACES)
2317 goto unfetch_interval;
2319 FREE_STACK_RETURN (REG_BADBR);
2322 if (!(syntax & RE_NO_BK_BRACES))
2324 if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
2331 if (syntax & RE_NO_BK_BRACES)
2332 goto unfetch_interval;
2334 FREE_STACK_RETURN (REG_BADBR);
2337 /* We just parsed a valid interval. */
2339 /* If it's invalid to have no preceding re. */
2342 if (syntax & RE_CONTEXT_INVALID_OPS)
2343 FREE_STACK_RETURN (REG_BADRPT);
2344 else if (syntax & RE_CONTEXT_INDEP_OPS)
2347 goto unfetch_interval;
2350 /* If the upper bound is zero, don't want to succeed at
2351 all; jump from `laststart' to `b + 3', which will be
2352 the end of the buffer after we insert the jump. */
2353 if (upper_bound == 0)
2355 GET_BUFFER_SPACE (3);
2356 INSERT_JUMP (jump, laststart, b + 3);
2360 /* Otherwise, we have a nontrivial interval. When
2361 we're all done, the pattern will look like:
2362 set_number_at <jump count> <upper bound>
2363 set_number_at <succeed_n count> <lower bound>
2364 succeed_n <after jump addr> <succeed_n count>
2366 jump_n <succeed_n addr> <jump count>
2367 (The upper bound and `jump_n' are omitted if
2368 `upper_bound' is 1, though.) */
2370 { /* If the upper bound is > 1, we need to insert
2371 more at the end of the loop. */
2372 unsigned nbytes = 10 + (upper_bound > 1) * 10;
2374 GET_BUFFER_SPACE (nbytes);
2376 /* Initialize lower bound of the `succeed_n', even
2377 though it will be set during matching by its
2378 attendant `set_number_at' (inserted next),
2379 because `re_compile_fastmap' needs to know.
2380 Jump to the `jump_n' we might insert below. */
2381 INSERT_JUMP2 (succeed_n, laststart,
2382 b + 5 + (upper_bound > 1) * 5,
2386 /* Code to initialize the lower bound. Insert
2387 before the `succeed_n'. The `5' is the last two
2388 bytes of this `set_number_at', plus 3 bytes of
2389 the following `succeed_n'. */
2390 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2393 if (upper_bound > 1)
2394 { /* More than one repetition is allowed, so
2395 append a backward jump to the `succeed_n'
2396 that starts this interval.
2398 When we've reached this during matching,
2399 we'll have matched the interval once, so
2400 jump back only `upper_bound - 1' times. */
2401 STORE_JUMP2 (jump_n, b, laststart + 5,
2405 /* The location we want to set is the second
2406 parameter of the `jump_n'; that is `b-2' as
2407 an absolute address. `laststart' will be
2408 the `set_number_at' we're about to insert;
2409 `laststart+3' the number to set, the source
2410 for the relative address. But we are
2411 inserting into the middle of the pattern --
2412 so everything is getting moved up by 5.
2413 Conclusion: (b - 2) - (laststart + 3) + 5,
2414 i.e., b - laststart.
2416 We insert this at the beginning of the loop
2417 so that if we fail during matching, we'll
2418 reinitialize the bounds. */
2419 insert_op2 (set_number_at, laststart, b - laststart,
2420 upper_bound - 1, b);
2425 beg_interval = NULL;
2430 /* If an invalid interval, match the characters as literals. */
2431 assert (beg_interval);
2433 beg_interval = NULL;
2435 /* normal_char and normal_backslash need `c'. */
2438 if (!(syntax & RE_NO_BK_BRACES))
2440 if (p > pattern && p[-1] == '\\')
2441 goto normal_backslash;
2446 /* There is no way to specify the before_dot and after_dot
2447 operators. rms says this is ok. --karl */
2455 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2461 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2468 BUF_PUSH (wordchar);
2474 BUF_PUSH (notwordchar);
2487 BUF_PUSH (wordbound);
2491 BUF_PUSH (notwordbound);
2502 case '1': case '2': case '3': case '4': case '5':
2503 case '6': case '7': case '8': case '9':
2504 if (syntax & RE_NO_BK_REFS)
2510 FREE_STACK_RETURN (REG_ESUBREG);
2512 /* Can't back reference to a subexpression if inside of it. */
2513 if (group_in_compile_stack (compile_stack, c1))
2517 BUF_PUSH_2 (duplicate, c1);
2523 if (syntax & RE_BK_PLUS_QM)
2526 goto normal_backslash;
2530 /* You might think it would be useful for \ to mean
2531 not to translate; but if we don't translate it
2532 it will never match anything. */
2540 /* Expects the character in `c'. */
2542 /* If no exactn currently being built. */
2545 /* If last exactn not at current position. */
2546 || pending_exact + *pending_exact + 1 != b
2548 /* We have only one byte following the exactn for the count. */
2549 || *pending_exact == (1 << BYTEWIDTH) - 1
2551 /* If followed by a repetition operator. */
2552 || *p == '*' || *p == '^'
2553 || ((syntax & RE_BK_PLUS_QM)
2554 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2555 : (*p == '+' || *p == '?'))
2556 || ((syntax & RE_INTERVALS)
2557 && ((syntax & RE_NO_BK_BRACES)
2559 : (p[0] == '\\' && p[1] == '{'))))
2561 /* Start building a new exactn. */
2565 BUF_PUSH_2 (exactn, 0);
2566 pending_exact = b - 1;
2573 } /* while p != pend */
2576 /* Through the pattern now. */
2579 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2581 if (!COMPILE_STACK_EMPTY)
2582 FREE_STACK_RETURN (REG_EPAREN);
2584 /* If we don't want backtracking, force success
2585 the first time we reach the end of the compiled pattern. */
2586 if (syntax & RE_NO_POSIX_BACKTRACKING)
2589 free (compile_stack.stack);
2591 /* We have succeeded; set the length of the buffer. */
2592 bufp->used = b - bufp->buffer;
2597 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2598 print_compiled_pattern (bufp);
2602 #ifndef MATCH_MAY_ALLOCATE
2603 /* Initialize the failure stack to the largest possible stack. This
2604 isn't necessary unless we're trying to avoid calling alloca in
2605 the search and match routines. */
2607 int num_regs = bufp->re_nsub + 1;
2609 /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2610 is strictly greater than re_max_failures, the largest possible stack
2611 is 2 * re_max_failures failure points. */
2612 if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
2614 fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2617 if (! fail_stack.stack)
2619 = (fail_stack_elt_t *) xmalloc (fail_stack.size
2620 * sizeof (fail_stack_elt_t));
2623 = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
2625 * sizeof (fail_stack_elt_t)));
2626 #else /* not emacs */
2627 if (! fail_stack.stack)
2629 = (fail_stack_elt_t *) malloc (fail_stack.size
2630 * sizeof (fail_stack_elt_t));
2633 = (fail_stack_elt_t *) realloc (fail_stack.stack,
2635 * sizeof (fail_stack_elt_t)));
2636 #endif /* not emacs */
2639 regex_grow_registers (num_regs);
2641 #endif /* not MATCH_MAY_ALLOCATE */
2644 } /* regex_compile */
2646 /* Subroutines for `regex_compile'. */
2648 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2651 store_op1 (op, loc, arg)
2656 *loc = (unsigned char) op;
2657 STORE_NUMBER (loc + 1, arg);
2661 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2664 store_op2 (op, loc, arg1, arg2)
2669 *loc = (unsigned char) op;
2670 STORE_NUMBER (loc + 1, arg1);
2671 STORE_NUMBER (loc + 3, arg2);
2675 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2676 for OP followed by two-byte integer parameter ARG. */
2679 insert_op1 (op, loc, arg, end)
2685 register unsigned char *pfrom = end;
2686 register unsigned char *pto = end + 3;
2688 while (pfrom != loc)
2691 store_op1 (op, loc, arg);
2695 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2698 insert_op2 (op, loc, arg1, arg2, end)
2704 register unsigned char *pfrom = end;
2705 register unsigned char *pto = end + 5;
2707 while (pfrom != loc)
2710 store_op2 (op, loc, arg1, arg2);
2714 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2715 after an alternative or a begin-subexpression. We assume there is at
2716 least one character before the ^. */
2719 at_begline_loc_p (pattern, p, syntax)
2720 const char *pattern, *p;
2721 reg_syntax_t syntax;
2723 const char *prev = p - 2;
2724 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2727 /* After a subexpression? */
2728 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2729 /* After an alternative? */
2730 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2734 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2735 at least one character after the $, i.e., `P < PEND'. */
2738 at_endline_loc_p (p, pend, syntax)
2739 const char *p, *pend;
2742 const char *next = p;
2743 boolean next_backslash = *next == '\\';
2744 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2747 /* Before a subexpression? */
2748 (syntax & RE_NO_BK_PARENS ? *next == ')'
2749 : next_backslash && next_next && *next_next == ')')
2750 /* Before an alternative? */
2751 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2752 : next_backslash && next_next && *next_next == '|');
2756 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2757 false if it's not. */
2760 group_in_compile_stack (compile_stack, regnum)
2761 compile_stack_type compile_stack;
2766 for (this_element = compile_stack.avail - 1;
2769 if (compile_stack.stack[this_element].regnum == regnum)
2776 /* Read the ending character of a range (in a bracket expression) from the
2777 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2778 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2779 Then we set the translation of all bits between the starting and
2780 ending characters (inclusive) in the compiled pattern B.
2782 Return an error code.
2784 We use these short variable names so we can use the same macros as
2785 `regex_compile' itself. */
2787 static reg_errcode_t
2788 compile_range (p_ptr, pend, translate, syntax, b)
2789 const char **p_ptr, *pend;
2791 reg_syntax_t syntax;
2796 const char *p = *p_ptr;
2797 int range_start, range_end;
2802 /* Even though the pattern is a signed `char *', we need to fetch
2803 with unsigned char *'s; if the high bit of the pattern character
2804 is set, the range endpoints will be negative if we fetch using a
2807 We also want to fetch the endpoints without translating them; the
2808 appropriate translation is done in the bit-setting loop below. */
2809 /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *. */
2810 range_start = ((const unsigned char *) p)[-2];
2811 range_end = ((const unsigned char *) p)[0];
2813 /* Have to increment the pointer into the pattern string, so the
2814 caller isn't still at the ending character. */
2817 /* If the start is after the end, the range is empty. */
2818 if (range_start > range_end)
2819 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2821 /* Here we see why `this_char' has to be larger than an `unsigned
2822 char' -- the range is inclusive, so if `range_end' == 0xff
2823 (assuming 8-bit characters), we would otherwise go into an infinite
2824 loop, since all characters <= 0xff. */
2825 for (this_char = range_start; this_char <= range_end; this_char++)
2827 SET_LIST_BIT (TRANSLATE (this_char));
2833 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2834 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2835 characters can start a string that matches the pattern. This fastmap
2836 is used by re_search to skip quickly over impossible starting points.
2838 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2839 area as BUFP->fastmap.
2841 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2844 Returns 0 if we succeed, -2 if an internal error. */
2847 re_compile_fastmap (bufp)
2848 struct re_pattern_buffer *bufp;
2851 #ifdef MATCH_MAY_ALLOCATE
2852 fail_stack_type fail_stack;
2854 #ifndef REGEX_MALLOC
2857 /* We don't push any register information onto the failure stack. */
2858 unsigned num_regs = 0;
2860 register char *fastmap = bufp->fastmap;
2861 unsigned char *pattern = bufp->buffer;
2862 unsigned long size = bufp->used;
2863 unsigned char *p = pattern;
2864 register unsigned char *pend = pattern + size;
2866 /* This holds the pointer to the failure stack, when
2867 it is allocated relocatably. */
2868 fail_stack_elt_t *failure_stack_ptr;
2870 /* Assume that each path through the pattern can be null until
2871 proven otherwise. We set this false at the bottom of switch
2872 statement, to which we get only if a particular path doesn't
2873 match the empty string. */
2874 boolean path_can_be_null = true;
2876 /* We aren't doing a `succeed_n' to begin with. */
2877 boolean succeed_n_p = false;
2879 assert (fastmap != NULL && p != NULL);
2882 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2883 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2884 bufp->can_be_null = 0;
2888 if (p == pend || *p == succeed)
2890 /* We have reached the (effective) end of pattern. */
2891 if (!FAIL_STACK_EMPTY ())
2893 bufp->can_be_null |= path_can_be_null;
2895 /* Reset for next path. */
2896 path_can_be_null = true;
2898 p = fail_stack.stack[--fail_stack.avail];
2906 /* We should never be about to go beyond the end of the pattern. */
2909 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
2912 /* I guess the idea here is to simply not bother with a fastmap
2913 if a backreference is used, since it's too hard to figure out
2914 the fastmap for the corresponding group. Setting
2915 `can_be_null' stops `re_search_2' from using the fastmap, so
2916 that is all we do. */
2918 bufp->can_be_null = 1;
2922 /* Following are the cases which match a character. These end
2931 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2932 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2938 /* Chars beyond end of map must be allowed. */
2939 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2942 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2943 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2949 for (j = 0; j < (1 << BYTEWIDTH); j++)
2950 if (SYNTAX (j) == Sword)
2956 for (j = 0; j < (1 << BYTEWIDTH); j++)
2957 if (SYNTAX (j) != Sword)
2964 int fastmap_newline = fastmap['\n'];
2966 /* `.' matches anything ... */
2967 for (j = 0; j < (1 << BYTEWIDTH); j++)
2970 /* ... except perhaps newline. */
2971 if (!(bufp->syntax & RE_DOT_NEWLINE))
2972 fastmap['\n'] = fastmap_newline;
2974 /* Return if we have already set `can_be_null'; if we have,
2975 then the fastmap is irrelevant. Something's wrong here. */
2976 else if (bufp->can_be_null)
2979 /* Otherwise, have to check alternative paths. */
2986 for (j = 0; j < (1 << BYTEWIDTH); j++)
2987 if (SYNTAX (j) == (enum syntaxcode) k)
2994 for (j = 0; j < (1 << BYTEWIDTH); j++)
2995 if (SYNTAX (j) != (enum syntaxcode) k)
3000 /* All cases after this match the empty string. These end with
3008 #endif /* not emacs */
3020 case push_dummy_failure:
3025 case pop_failure_jump:
3026 case maybe_pop_jump:
3029 case dummy_failure_jump:
3030 EXTRACT_NUMBER_AND_INCR (j, p);
3035 /* Jump backward implies we just went through the body of a
3036 loop and matched nothing. Opcode jumped to should be
3037 `on_failure_jump' or `succeed_n'. Just treat it like an
3038 ordinary jump. For a * loop, it has pushed its failure
3039 point already; if so, discard that as redundant. */
3040 if ((re_opcode_t) *p != on_failure_jump
3041 && (re_opcode_t) *p != succeed_n)
3045 EXTRACT_NUMBER_AND_INCR (j, p);
3048 /* If what's on the stack is where we are now, pop it. */
3049 if (!FAIL_STACK_EMPTY ()
3050 && fail_stack.stack[fail_stack.avail - 1] == p)
3056 case on_failure_jump:
3057 case on_failure_keep_string_jump:
3058 handle_on_failure_jump:
3059 EXTRACT_NUMBER_AND_INCR (j, p);
3061 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
3062 end of the pattern. We don't want to push such a point,
3063 since when we restore it above, entering the switch will
3064 increment `p' past the end of the pattern. We don't need
3065 to push such a point since we obviously won't find any more
3066 fastmap entries beyond `pend'. Such a pattern can match
3067 the null string, though. */
3070 if (!PUSH_PATTERN_OP (p + j, fail_stack))
3072 REGEX_FREE_STACK (fail_stack.stack);
3077 bufp->can_be_null = 1;
3081 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
3082 succeed_n_p = false;
3089 /* Get to the number of times to succeed. */
3092 /* Increment p past the n for when k != 0. */
3093 EXTRACT_NUMBER_AND_INCR (k, p);
3097 succeed_n_p = true; /* Spaghetti code alert. */
3098 goto handle_on_failure_jump;
3115 abort (); /* We have listed all the cases. */
3118 /* Getting here means we have found the possible starting
3119 characters for one path of the pattern -- and that the empty
3120 string does not match. We need not follow this path further.
3121 Instead, look at the next alternative (remembered on the
3122 stack), or quit if no more. The test at the top of the loop
3123 does these things. */
3124 path_can_be_null = false;
3128 /* Set `can_be_null' for the last path (also the first path, if the
3129 pattern is empty). */
3130 bufp->can_be_null |= path_can_be_null;
3133 REGEX_FREE_STACK (fail_stack.stack);
3135 } /* re_compile_fastmap */
3137 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
3138 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
3139 this memory for recording register information. STARTS and ENDS
3140 must be allocated using the malloc library routine, and must each
3141 be at least NUM_REGS * sizeof (regoff_t) bytes long.
3143 If NUM_REGS == 0, then subsequent matches should allocate their own
3146 Unless this function is called, the first search or match using
3147 PATTERN_BUFFER will allocate its own register data, without
3148 freeing the old data. */
3151 re_set_registers (bufp, regs, num_regs, starts, ends)
3152 struct re_pattern_buffer *bufp;
3153 struct re_registers *regs;
3155 regoff_t *starts, *ends;
3159 bufp->regs_allocated = REGS_REALLOCATE;
3160 regs->num_regs = num_regs;
3161 regs->start = starts;
3166 bufp->regs_allocated = REGS_UNALLOCATED;
3168 regs->start = regs->end = (regoff_t *) 0;
3172 /* Searching routines. */
3174 /* Like re_search_2, below, but only one string is specified, and
3175 doesn't let you say where to stop matching. */
3178 re_search (bufp, string, size, startpos, range, regs)
3179 struct re_pattern_buffer *bufp;
3181 int size, startpos, range;
3182 struct re_registers *regs;
3184 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3189 /* Using the compiled pattern in BUFP->buffer, first tries to match the
3190 virtual concatenation of STRING1 and STRING2, starting first at index
3191 STARTPOS, then at STARTPOS + 1, and so on.
3193 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3195 RANGE is how far to scan while trying to match. RANGE = 0 means try
3196 only at STARTPOS; in general, the last start tried is STARTPOS +
3199 In REGS, return the indices of the virtual concatenation of STRING1
3200 and STRING2 that matched the entire BUFP->buffer and its contained
3203 Do not consider matching one past the index STOP in the virtual
3204 concatenation of STRING1 and STRING2.
3206 We return either the position in the strings at which the match was
3207 found, -1 if no match, or -2 if error (such as failure
3211 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3212 struct re_pattern_buffer *bufp;
3213 const char *string1, *string2;
3217 struct re_registers *regs;
3221 register char *fastmap = bufp->fastmap;
3222 register char *translate = bufp->translate;
3223 int total_size = size1 + size2;
3224 int endpos = startpos + range;
3226 /* Check for out-of-range STARTPOS. */
3227 if (startpos < 0 || startpos > total_size)
3230 /* Fix up RANGE if it might eventually take us outside
3231 the virtual concatenation of STRING1 and STRING2. */
3233 range = -1 - startpos;
3234 else if (endpos > total_size)
3235 range = total_size - startpos;
3237 /* If the search isn't to be a backwards one, don't waste time in a
3238 search for a pattern that must be anchored. */
3239 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3247 /* Update the fastmap now if not correct already. */
3248 if (fastmap && !bufp->fastmap_accurate)
3249 if (re_compile_fastmap (bufp) == -2)
3252 /* Loop through the string, looking for a place to start matching. */
3255 /* If a fastmap is supplied, skip quickly over characters that
3256 cannot be the start of a match. If the pattern can match the
3257 null string, however, we don't need to skip characters; we want
3258 the first null string. */
3259 if (fastmap && startpos < total_size && !bufp->can_be_null)
3261 if (range > 0) /* Searching forwards. */
3263 register const char *d;
3264 register int lim = 0;
3267 if (startpos < size1 && startpos + range >= size1)
3268 lim = range - (size1 - startpos);
3270 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3272 /* Written out as an if-else to avoid testing `translate'
3276 && !fastmap[(unsigned char)
3277 translate[(unsigned char) *d++]])
3280 while (range > lim && !fastmap[(unsigned char) *d++])
3283 startpos += irange - range;
3285 else /* Searching backwards. */
3287 register char c = (size1 == 0 || startpos >= size1
3288 ? string2[startpos - size1]
3289 : string1[startpos]);
3291 if (!fastmap[(unsigned char) TRANSLATE (c)])
3296 /* If can't match the null string, and that's all we have left, fail. */
3297 if (range >= 0 && startpos == total_size && fastmap
3298 && !bufp->can_be_null)
3301 val = re_match_2_internal (bufp, string1, size1, string2, size2,
3302 startpos, regs, stop);
3303 #ifndef REGEX_MALLOC
3332 /* Declarations and macros for re_match_2. */
3334 static int bcmp_translate ();
3335 static boolean alt_match_null_string_p (),
3336 common_op_match_null_string_p (),
3337 group_match_null_string_p ();
3339 /* This converts PTR, a pointer into one of the search strings `string1'
3340 and `string2' into an offset from the beginning of that string. */
3341 #define POINTER_TO_OFFSET(ptr) \
3342 (FIRST_STRING_P (ptr) \
3343 ? ((regoff_t) ((ptr) - string1)) \
3344 : ((regoff_t) ((ptr) - string2 + size1)))
3346 /* Macros for dealing with the split strings in re_match_2. */
3348 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3350 /* Call before fetching a character with *d. This switches over to
3351 string2 if necessary. */
3352 #define PREFETCH() \
3355 /* End of string2 => fail. */ \
3356 if (dend == end_match_2) \
3358 /* End of string1 => advance to string2. */ \
3360 dend = end_match_2; \
3364 /* Test if at very beginning or at very end of the virtual concatenation
3365 of `string1' and `string2'. If only one string, it's `string2'. */
3366 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3367 #define AT_STRINGS_END(d) ((d) == end2)
3370 /* Test if D points to a character which is word-constituent. We have
3371 two special cases to check for: if past the end of string1, look at
3372 the first character in string2; and if before the beginning of
3373 string2, look at the last character in string1. */
3374 #define WORDCHAR_P(d) \
3375 (SYNTAX ((d) == end1 ? *string2 \
3376 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3379 /* Test if the character before D and the one at D differ with respect
3380 to being word-constituent. */
3381 #define AT_WORD_BOUNDARY(d) \
3382 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3383 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3386 /* Free everything we malloc. */
3387 #ifdef MATCH_MAY_ALLOCATE
3388 #define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
3389 #define FREE_VARIABLES() \
3391 REGEX_FREE_STACK (fail_stack.stack); \
3392 FREE_VAR (regstart); \
3393 FREE_VAR (regend); \
3394 FREE_VAR (old_regstart); \
3395 FREE_VAR (old_regend); \
3396 FREE_VAR (best_regstart); \
3397 FREE_VAR (best_regend); \
3398 FREE_VAR (reg_info); \
3399 FREE_VAR (reg_dummy); \
3400 FREE_VAR (reg_info_dummy); \
3403 #define FREE_VARIABLES() /* Do nothing! */
3404 #endif /* not MATCH_MAY_ALLOCATE */
3406 /* These values must meet several constraints. They must not be valid
3407 register values; since we have a limit of 255 registers (because
3408 we use only one byte in the pattern for the register number), we can
3409 use numbers larger than 255. They must differ by 1, because of
3410 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3411 be larger than the value for the highest register, so we do not try
3412 to actually save any registers when none are active. */
3413 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3414 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3416 /* Matching routines. */
3418 #ifndef emacs /* Emacs never uses this. */
3419 /* re_match is like re_match_2 except it takes only a single string. */
3422 re_match (bufp, string, size, pos, regs)
3423 struct re_pattern_buffer *bufp;
3426 struct re_registers *regs;
3428 int result = re_match_2_internal (bufp, NULL, 0, string, size,
3433 #endif /* not emacs */
3436 /* re_match_2 matches the compiled pattern in BUFP against the
3437 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3438 and SIZE2, respectively). We start matching at POS, and stop
3441 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3442 store offsets for the substring each group matched in REGS. See the
3443 documentation for exactly how many groups we fill.
3445 We return -1 if no match, -2 if an internal error (such as the
3446 failure stack overflowing). Otherwise, we return the length of the
3447 matched substring. */
3450 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3451 struct re_pattern_buffer *bufp;
3452 const char *string1, *string2;
3455 struct re_registers *regs;
3458 int result = re_match_2_internal (bufp, string1, size1, string2, size2,
3464 /* This is a separate function so that we can force an alloca cleanup
3467 re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
3468 struct re_pattern_buffer *bufp;
3469 const char *string1, *string2;
3472 struct re_registers *regs;
3475 /* General temporaries. */
3479 /* Just past the end of the corresponding string. */
3480 const char *end1, *end2;
3482 /* Pointers into string1 and string2, just past the last characters in
3483 each to consider matching. */
3484 const char *end_match_1, *end_match_2;
3486 /* Where we are in the data, and the end of the current string. */
3487 const char *d, *dend;
3489 /* Where we are in the pattern, and the end of the pattern. */
3490 unsigned char *p = bufp->buffer;
3491 register unsigned char *pend = p + bufp->used;
3493 /* Mark the opcode just after a start_memory, so we can test for an
3494 empty subpattern when we get to the stop_memory. */
3495 unsigned char *just_past_start_mem = 0;
3497 /* We use this to map every character in the string. */
3498 char *translate = bufp->translate;
3500 /* Failure point stack. Each place that can handle a failure further
3501 down the line pushes a failure point on this stack. It consists of
3502 restart, regend, and reg_info for all registers corresponding to
3503 the subexpressions we're currently inside, plus the number of such
3504 registers, and, finally, two char *'s. The first char * is where
3505 to resume scanning the pattern; the second one is where to resume
3506 scanning the strings. If the latter is zero, the failure point is
3507 a ``dummy''; if a failure happens and the failure point is a dummy,
3508 it gets discarded and the next next one is tried. */
3509 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3510 fail_stack_type fail_stack;
3513 static unsigned failure_id = 0;
3514 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3517 /* This holds the pointer to the failure stack, when
3518 it is allocated relocatably. */
3519 fail_stack_elt_t *failure_stack_ptr;
3521 /* We fill all the registers internally, independent of what we
3522 return, for use in backreferences. The number here includes
3523 an element for register zero. */
3524 unsigned num_regs = bufp->re_nsub + 1;
3526 /* The currently active registers. */
3527 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3528 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3530 /* Information on the contents of registers. These are pointers into
3531 the input strings; they record just what was matched (on this
3532 attempt) by a subexpression part of the pattern, that is, the
3533 regnum-th regstart pointer points to where in the pattern we began
3534 matching and the regnum-th regend points to right after where we
3535 stopped matching the regnum-th subexpression. (The zeroth register
3536 keeps track of what the whole pattern matches.) */
3537 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3538 const char **regstart, **regend;
3541 /* If a group that's operated upon by a repetition operator fails to
3542 match anything, then the register for its start will need to be
3543 restored because it will have been set to wherever in the string we
3544 are when we last see its open-group operator. Similarly for a
3546 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3547 const char **old_regstart, **old_regend;
3550 /* The is_active field of reg_info helps us keep track of which (possibly
3551 nested) subexpressions we are currently in. The matched_something
3552 field of reg_info[reg_num] helps us tell whether or not we have
3553 matched any of the pattern so far this time through the reg_num-th
3554 subexpression. These two fields get reset each time through any
3555 loop their register is in. */
3556 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3557 register_info_type *reg_info;
3560 /* The following record the register info as found in the above
3561 variables when we find a match better than any we've seen before.
3562 This happens as we backtrack through the failure points, which in
3563 turn happens only if we have not yet matched the entire string. */
3564 unsigned best_regs_set = false;
3565 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3566 const char **best_regstart, **best_regend;
3569 /* Logically, this is `best_regend[0]'. But we don't want to have to
3570 allocate space for that if we're not allocating space for anything
3571 else (see below). Also, we never need info about register 0 for
3572 any of the other register vectors, and it seems rather a kludge to
3573 treat `best_regend' differently than the rest. So we keep track of
3574 the end of the best match so far in a separate variable. We
3575 initialize this to NULL so that when we backtrack the first time
3576 and need to test it, it's not garbage. */
3577 const char *match_end = NULL;
3579 /* This helps SET_REGS_MATCHED avoid doing redundant work. */
3580 int set_regs_matched_done = 0;
3582 /* Used when we pop values we don't care about. */
3583 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3584 const char **reg_dummy;
3585 register_info_type *reg_info_dummy;
3589 /* Counts the total number of registers pushed. */
3590 unsigned num_regs_pushed = 0;
3593 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3597 #ifdef MATCH_MAY_ALLOCATE
3598 /* Do not bother to initialize all the register variables if there are
3599 no groups in the pattern, as it takes a fair amount of time. If
3600 there are groups, we include space for register 0 (the whole
3601 pattern), even though we never use it, since it simplifies the
3602 array indexing. We should fix this. */
3605 regstart = REGEX_TALLOC (num_regs, const char *);
3606 regend = REGEX_TALLOC (num_regs, const char *);
3607 old_regstart = REGEX_TALLOC (num_regs, const char *);
3608 old_regend = REGEX_TALLOC (num_regs, const char *);
3609 best_regstart = REGEX_TALLOC (num_regs, const char *);
3610 best_regend = REGEX_TALLOC (num_regs, const char *);
3611 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3612 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3613 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3615 if (!(regstart && regend && old_regstart && old_regend && reg_info
3616 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3624 /* We must initialize all our variables to NULL, so that
3625 `FREE_VARIABLES' doesn't try to free them. */
3626 regstart = regend = old_regstart = old_regend = best_regstart
3627 = best_regend = reg_dummy = NULL;
3628 reg_info = reg_info_dummy = (register_info_type *) NULL;
3630 #endif /* MATCH_MAY_ALLOCATE */
3632 /* The starting position is bogus. */
3633 if (pos < 0 || pos > size1 + size2)
3639 /* Initialize subexpression text positions to -1 to mark ones that no
3640 start_memory/stop_memory has been seen for. Also initialize the
3641 register information struct. */
3642 for (mcnt = 1; mcnt < num_regs; mcnt++)
3644 regstart[mcnt] = regend[mcnt]
3645 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3647 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3648 IS_ACTIVE (reg_info[mcnt]) = 0;
3649 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3650 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3653 /* We move `string1' into `string2' if the latter's empty -- but not if
3654 `string1' is null. */
3655 if (size2 == 0 && string1 != NULL)
3662 end1 = string1 + size1;
3663 end2 = string2 + size2;
3665 /* Compute where to stop matching, within the two strings. */
3668 end_match_1 = string1 + stop;
3669 end_match_2 = string2;
3674 end_match_2 = string2 + stop - size1;
3677 /* `p' scans through the pattern as `d' scans through the data.
3678 `dend' is the end of the input string that `d' points within. `d'
3679 is advanced into the following input string whenever necessary, but
3680 this happens before fetching; therefore, at the beginning of the
3681 loop, `d' can be pointing at the end of a string, but it cannot
3683 if (size1 > 0 && pos <= size1)
3690 d = string2 + pos - size1;
3694 DEBUG_PRINT1 ("The compiled pattern is: ");
3695 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3696 DEBUG_PRINT1 ("The string to match is: `");
3697 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3698 DEBUG_PRINT1 ("'\n");
3700 /* This loops over pattern commands. It exits by returning from the
3701 function if the match is complete, or it drops through if the match
3702 fails at this starting point in the input data. */
3705 DEBUG_PRINT2 ("\n0x%x: ", p);
3708 { /* End of pattern means we might have succeeded. */
3709 DEBUG_PRINT1 ("end of pattern ... ");
3711 /* If we haven't matched the entire string, and we want the
3712 longest match, try backtracking. */
3713 if (d != end_match_2)
3715 /* 1 if this match ends in the same string (string1 or string2)
3716 as the best previous match. */
3717 boolean same_str_p = (FIRST_STRING_P (match_end)
3718 == MATCHING_IN_FIRST_STRING);
3719 /* 1 if this match is the best seen so far. */
3720 boolean best_match_p;
3722 /* AIX compiler got confused when this was combined
3723 with the previous declaration. */
3725 best_match_p = d > match_end;
3727 best_match_p = !MATCHING_IN_FIRST_STRING;
3729 DEBUG_PRINT1 ("backtracking.\n");
3731 if (!FAIL_STACK_EMPTY ())
3732 { /* More failure points to try. */
3734 /* If exceeds best match so far, save it. */
3735 if (!best_regs_set || best_match_p)
3737 best_regs_set = true;
3740 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3742 for (mcnt = 1; mcnt < num_regs; mcnt++)
3744 best_regstart[mcnt] = regstart[mcnt];
3745 best_regend[mcnt] = regend[mcnt];
3751 /* If no failure points, don't restore garbage. And if
3752 last match is real best match, don't restore second
3754 else if (best_regs_set && !best_match_p)
3757 /* Restore best match. It may happen that `dend ==
3758 end_match_1' while the restored d is in string2.
3759 For example, the pattern `x.*y.*z' against the
3760 strings `x-' and `y-z-', if the two strings are
3761 not consecutive in memory. */
3762 DEBUG_PRINT1 ("Restoring best registers.\n");
3765 dend = ((d >= string1 && d <= end1)
3766 ? end_match_1 : end_match_2);
3768 for (mcnt = 1; mcnt < num_regs; mcnt++)
3770 regstart[mcnt] = best_regstart[mcnt];
3771 regend[mcnt] = best_regend[mcnt];
3774 } /* d != end_match_2 */
3777 DEBUG_PRINT1 ("Accepting match.\n");
3779 /* If caller wants register contents data back, do it. */
3780 if (regs && !bufp->no_sub)
3782 /* Have the register data arrays been allocated? */
3783 if (bufp->regs_allocated == REGS_UNALLOCATED)
3784 { /* No. So allocate them with malloc. We need one
3785 extra element beyond `num_regs' for the `-1' marker
3787 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3788 regs->start = TALLOC (regs->num_regs, regoff_t);
3789 regs->end = TALLOC (regs->num_regs, regoff_t);
3790 if (regs->start == NULL || regs->end == NULL)
3795 bufp->regs_allocated = REGS_REALLOCATE;
3797 else if (bufp->regs_allocated == REGS_REALLOCATE)
3798 { /* Yes. If we need more elements than were already
3799 allocated, reallocate them. If we need fewer, just
3801 if (regs->num_regs < num_regs + 1)
3803 regs->num_regs = num_regs + 1;
3804 RETALLOC (regs->start, regs->num_regs, regoff_t);
3805 RETALLOC (regs->end, regs->num_regs, regoff_t);
3806 if (regs->start == NULL || regs->end == NULL)
3815 /* These braces fend off a "empty body in an else-statement"
3816 warning under GCC when assert expands to nothing. */
3817 assert (bufp->regs_allocated == REGS_FIXED);
3820 /* Convert the pointer data in `regstart' and `regend' to
3821 indices. Register zero has to be set differently,
3822 since we haven't kept track of any info for it. */
3823 if (regs->num_regs > 0)
3825 regs->start[0] = pos;
3826 regs->end[0] = (MATCHING_IN_FIRST_STRING
3827 ? ((regoff_t) (d - string1))
3828 : ((regoff_t) (d - string2 + size1)));
3831 /* Go through the first `min (num_regs, regs->num_regs)'
3832 registers, since that is all we initialized. */
3833 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3835 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3836 regs->start[mcnt] = regs->end[mcnt] = -1;
3840 = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
3842 = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
3846 /* If the regs structure we return has more elements than
3847 were in the pattern, set the extra elements to -1. If
3848 we (re)allocated the registers, this is the case,
3849 because we always allocate enough to have at least one
3851 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3852 regs->start[mcnt] = regs->end[mcnt] = -1;
3853 } /* regs && !bufp->no_sub */
3855 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3856 nfailure_points_pushed, nfailure_points_popped,
3857 nfailure_points_pushed - nfailure_points_popped);
3858 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3860 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3864 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3870 /* Otherwise match next pattern command. */
3871 switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
3873 /* Ignore these. Used to ignore the n of succeed_n's which
3874 currently have n == 0. */
3876 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3880 DEBUG_PRINT1 ("EXECUTING succeed.\n");
3883 /* Match the next n pattern characters exactly. The following
3884 byte in the pattern defines n, and the n bytes after that
3885 are the characters to match. */
3888 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3890 /* This is written out as an if-else so we don't waste time
3891 testing `translate' inside the loop. */
3897 if (translate[(unsigned char) *d++] != (char) *p++)
3907 if (*d++ != (char) *p++) goto fail;
3911 SET_REGS_MATCHED ();
3915 /* Match any character except possibly a newline or a null. */
3917 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3921 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3922 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3925 SET_REGS_MATCHED ();
3926 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3934 register unsigned char c;
3935 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3937 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3940 c = TRANSLATE (*d); /* The character to match. */
3942 /* Cast to `unsigned' instead of `unsigned char' in case the
3943 bit list is a full 32 bytes long. */
3944 if (c < (unsigned) (*p * BYTEWIDTH)
3945 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3950 if (!not) goto fail;
3952 SET_REGS_MATCHED ();
3958 /* The beginning of a group is represented by start_memory.
3959 The arguments are the register number in the next byte, and the
3960 number of groups inner to this one in the next. The text
3961 matched within the group is recorded (in the internal
3962 registers data structure) under the register number. */
3964 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3966 /* Find out if this group can match the empty string. */
3967 p1 = p; /* To send to group_match_null_string_p. */
3969 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3970 REG_MATCH_NULL_STRING_P (reg_info[*p])
3971 = group_match_null_string_p (&p1, pend, reg_info);
3973 /* Save the position in the string where we were the last time
3974 we were at this open-group operator in case the group is
3975 operated upon by a repetition operator, e.g., with `(a*)*b'
3976 against `ab'; then we want to ignore where we are now in
3977 the string in case this attempt to match fails. */
3978 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3979 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3981 DEBUG_PRINT2 (" old_regstart: %d\n",
3982 POINTER_TO_OFFSET (old_regstart[*p]));
3985 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
3987 IS_ACTIVE (reg_info[*p]) = 1;
3988 MATCHED_SOMETHING (reg_info[*p]) = 0;
3990 /* Clear this whenever we change the register activity status. */
3991 set_regs_matched_done = 0;
3993 /* This is the new highest active register. */
3994 highest_active_reg = *p;
3996 /* If nothing was active before, this is the new lowest active
3998 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3999 lowest_active_reg = *p;
4001 /* Move past the register number and inner group count. */
4003 just_past_start_mem = p;
4008 /* The stop_memory opcode represents the end of a group. Its
4009 arguments are the same as start_memory's: the register
4010 number, and the number of inner groups. */
4012 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
4014 /* We need to save the string position the last time we were at
4015 this close-group operator in case the group is operated
4016 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
4017 against `aba'; then we want to ignore where we are now in
4018 the string in case this attempt to match fails. */
4019 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
4020 ? REG_UNSET (regend[*p]) ? d : regend[*p]
4022 DEBUG_PRINT2 (" old_regend: %d\n",
4023 POINTER_TO_OFFSET (old_regend[*p]));
4026 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
4028 /* This register isn't active anymore. */
4029 IS_ACTIVE (reg_info[*p]) = 0;
4031 /* Clear this whenever we change the register activity status. */
4032 set_regs_matched_done = 0;
4034 /* If this was the only register active, nothing is active
4036 if (lowest_active_reg == highest_active_reg)
4038 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4039 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4042 { /* We must scan for the new highest active register, since
4043 it isn't necessarily one less than now: consider
4044 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
4045 new highest active register is 1. */
4046 unsigned char r = *p - 1;
4047 while (r > 0 && !IS_ACTIVE (reg_info[r]))
4050 /* If we end up at register zero, that means that we saved
4051 the registers as the result of an `on_failure_jump', not
4052 a `start_memory', and we jumped to past the innermost
4053 `stop_memory'. For example, in ((.)*) we save
4054 registers 1 and 2 as a result of the *, but when we pop
4055 back to the second ), we are at the stop_memory 1.
4056 Thus, nothing is active. */
4059 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
4060 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
4063 highest_active_reg = r;
4066 /* If just failed to match something this time around with a
4067 group that's operated on by a repetition operator, try to
4068 force exit from the ``loop'', and restore the register
4069 information for this group that we had before trying this
4071 if ((!MATCHED_SOMETHING (reg_info[*p])
4072 || just_past_start_mem == p - 1)
4075 boolean is_a_jump_n = false;
4079 switch ((re_opcode_t) *p1++)
4083 case pop_failure_jump:
4084 case maybe_pop_jump:
4086 case dummy_failure_jump:
4087 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4097 /* If the next operation is a jump backwards in the pattern
4098 to an on_failure_jump right before the start_memory
4099 corresponding to this stop_memory, exit from the loop
4100 by forcing a failure after pushing on the stack the
4101 on_failure_jump's jump in the pattern, and d. */
4102 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
4103 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
4105 /* If this group ever matched anything, then restore
4106 what its registers were before trying this last
4107 failed match, e.g., with `(a*)*b' against `ab' for
4108 regstart[1], and, e.g., with `((a*)*(b*)*)*'
4109 against `aba' for regend[3].
4111 Also restore the registers for inner groups for,
4112 e.g., `((a*)(b*))*' against `aba' (register 3 would
4113 otherwise get trashed). */
4115 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
4119 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
4121 /* Restore this and inner groups' (if any) registers. */
4122 for (r = *p; r < *p + *(p + 1); r++)
4124 regstart[r] = old_regstart[r];
4126 /* xx why this test? */
4127 if (old_regend[r] >= regstart[r])
4128 regend[r] = old_regend[r];
4132 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4133 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
4139 /* Move past the register number and the inner group count. */
4144 /* \<digit> has been turned into a `duplicate' command which is
4145 followed by the numeric value of <digit> as the register number. */
4148 register const char *d2, *dend2;
4149 int regno = *p++; /* Get which register to match against. */
4150 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
4152 /* Can't back reference a group which we've never matched. */
4153 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
4156 /* Where in input to try to start matching. */
4157 d2 = regstart[regno];
4159 /* Where to stop matching; if both the place to start and
4160 the place to stop matching are in the same string, then
4161 set to the place to stop, otherwise, for now have to use
4162 the end of the first string. */
4164 dend2 = ((FIRST_STRING_P (regstart[regno])
4165 == FIRST_STRING_P (regend[regno]))
4166 ? regend[regno] : end_match_1);
4169 /* If necessary, advance to next segment in register
4173 if (dend2 == end_match_2) break;
4174 if (dend2 == regend[regno]) break;
4176 /* End of string1 => advance to string2. */
4178 dend2 = regend[regno];
4180 /* At end of register contents => success */
4181 if (d2 == dend2) break;
4183 /* If necessary, advance to next segment in data. */
4186 /* How many characters left in this segment to match. */
4189 /* Want how many consecutive characters we can match in
4190 one shot, so, if necessary, adjust the count. */
4191 if (mcnt > dend2 - d2)
4194 /* Compare that many; failure if mismatch, else move
4197 ? bcmp_translate (d, d2, mcnt, translate)
4198 : bcmp (d, d2, mcnt))
4200 d += mcnt, d2 += mcnt;
4202 /* Do this because we've match some characters. */
4203 SET_REGS_MATCHED ();
4209 /* begline matches the empty string at the beginning of the string
4210 (unless `not_bol' is set in `bufp'), and, if
4211 `newline_anchor' is set, after newlines. */
4213 DEBUG_PRINT1 ("EXECUTING begline.\n");
4215 if (AT_STRINGS_BEG (d))
4217 if (!bufp->not_bol) break;
4219 else if (d[-1] == '\n' && bufp->newline_anchor)
4223 /* In all other cases, we fail. */
4227 /* endline is the dual of begline. */
4229 DEBUG_PRINT1 ("EXECUTING endline.\n");
4231 if (AT_STRINGS_END (d))
4233 if (!bufp->not_eol) break;
4236 /* We have to ``prefetch'' the next character. */
4237 else if ((d == end1 ? *string2 : *d) == '\n'
4238 && bufp->newline_anchor)
4245 /* Match at the very beginning of the data. */
4247 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4248 if (AT_STRINGS_BEG (d))
4253 /* Match at the very end of the data. */
4255 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4256 if (AT_STRINGS_END (d))
4261 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
4262 pushes NULL as the value for the string on the stack. Then
4263 `pop_failure_point' will keep the current value for the
4264 string, instead of restoring it. To see why, consider
4265 matching `foo\nbar' against `.*\n'. The .* matches the foo;
4266 then the . fails against the \n. But the next thing we want
4267 to do is match the \n against the \n; if we restored the
4268 string value, we would be back at the foo.
4270 Because this is used only in specific cases, we don't need to
4271 check all the things that `on_failure_jump' does, to make
4272 sure the right things get saved on the stack. Hence we don't
4273 share its code. The only reason to push anything on the
4274 stack at all is that otherwise we would have to change
4275 `anychar's code to do something besides goto fail in this
4276 case; that seems worse than this. */
4277 case on_failure_keep_string_jump:
4278 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4280 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4281 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4283 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4287 /* Uses of on_failure_jump:
4289 Each alternative starts with an on_failure_jump that points
4290 to the beginning of the next alternative. Each alternative
4291 except the last ends with a jump that in effect jumps past
4292 the rest of the alternatives. (They really jump to the
4293 ending jump of the following alternative, because tensioning
4294 these jumps is a hassle.)
4296 Repeats start with an on_failure_jump that points past both
4297 the repetition text and either the following jump or
4298 pop_failure_jump back to this on_failure_jump. */
4299 case on_failure_jump:
4301 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4303 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4304 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4306 /* If this on_failure_jump comes right before a group (i.e.,
4307 the original * applied to a group), save the information
4308 for that group and all inner ones, so that if we fail back
4309 to this point, the group's information will be correct.
4310 For example, in \(a*\)*\1, we need the preceding group,
4311 and in \(\(a*\)b*\)\2, we need the inner group. */
4313 /* We can't use `p' to check ahead because we push
4314 a failure point to `p + mcnt' after we do this. */
4317 /* We need to skip no_op's before we look for the
4318 start_memory in case this on_failure_jump is happening as
4319 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
4321 while (p1 < pend && (re_opcode_t) *p1 == no_op)
4324 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
4326 /* We have a new highest active register now. This will
4327 get reset at the start_memory we are about to get to,
4328 but we will have saved all the registers relevant to
4329 this repetition op, as described above. */
4330 highest_active_reg = *(p1 + 1) + *(p1 + 2);
4331 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4332 lowest_active_reg = *(p1 + 1);
4335 DEBUG_PRINT1 (":\n");
4336 PUSH_FAILURE_POINT (p + mcnt, d, -2);
4340 /* A smart repeat ends with `maybe_pop_jump'.
4341 We change it to either `pop_failure_jump' or `jump'. */
4342 case maybe_pop_jump:
4343 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4344 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4346 register unsigned char *p2 = p;
4348 /* Compare the beginning of the repeat with what in the
4349 pattern follows its end. If we can establish that there
4350 is nothing that they would both match, i.e., that we
4351 would have to backtrack because of (as in, e.g., `a*a')
4352 then we can change to pop_failure_jump, because we'll
4353 never have to backtrack.
4355 This is not true in the case of alternatives: in
4356 `(a|ab)*' we do need to backtrack to the `ab' alternative
4357 (e.g., if the string was `ab'). But instead of trying to
4358 detect that here, the alternative has put on a dummy
4359 failure point which is what we will end up popping. */
4361 /* Skip over open/close-group commands.
4362 If what follows this loop is a ...+ construct,
4363 look at what begins its body, since we will have to
4364 match at least one of that. */
4368 && ((re_opcode_t) *p2 == stop_memory
4369 || (re_opcode_t) *p2 == start_memory))
4371 else if (p2 + 6 < pend
4372 && (re_opcode_t) *p2 == dummy_failure_jump)
4379 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4380 to the `maybe_finalize_jump' of this case. Examine what
4383 /* If we're at the end of the pattern, we can change. */
4386 /* Consider what happens when matching ":\(.*\)"
4387 against ":/". I don't really understand this code
4389 p[-3] = (unsigned char) pop_failure_jump;
4391 (" End of pattern: change to `pop_failure_jump'.\n");
4394 else if ((re_opcode_t) *p2 == exactn
4395 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4397 register unsigned char c
4398 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4400 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4402 p[-3] = (unsigned char) pop_failure_jump;
4403 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4407 else if ((re_opcode_t) p1[3] == charset
4408 || (re_opcode_t) p1[3] == charset_not)
4410 int not = (re_opcode_t) p1[3] == charset_not;
4412 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4413 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4416 /* `not' is equal to 1 if c would match, which means
4417 that we can't change to pop_failure_jump. */
4420 p[-3] = (unsigned char) pop_failure_jump;
4421 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4425 else if ((re_opcode_t) *p2 == charset)
4428 register unsigned char c
4429 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4432 if ((re_opcode_t) p1[3] == exactn
4433 && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
4434 && (p2[1 + p1[4] / BYTEWIDTH]
4435 & (1 << (p1[4] % BYTEWIDTH)))))
4437 p[-3] = (unsigned char) pop_failure_jump;
4438 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4442 else if ((re_opcode_t) p1[3] == charset_not)
4445 /* We win if the charset_not inside the loop
4446 lists every character listed in the charset after. */
4447 for (idx = 0; idx < (int) p2[1]; idx++)
4448 if (! (p2[2 + idx] == 0
4449 || (idx < (int) p1[4]
4450 && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
4455 p[-3] = (unsigned char) pop_failure_jump;
4456 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4459 else if ((re_opcode_t) p1[3] == charset)
4462 /* We win if the charset inside the loop
4463 has no overlap with the one after the loop. */
4465 idx < (int) p2[1] && idx < (int) p1[4];
4467 if ((p2[2 + idx] & p1[5 + idx]) != 0)
4470 if (idx == p2[1] || idx == p1[4])
4472 p[-3] = (unsigned char) pop_failure_jump;
4473 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4478 p -= 2; /* Point at relative address again. */
4479 if ((re_opcode_t) p[-1] != pop_failure_jump)
4481 p[-1] = (unsigned char) jump;
4482 DEBUG_PRINT1 (" Match => jump.\n");
4483 goto unconditional_jump;
4485 /* Note fall through. */
4488 /* The end of a simple repeat has a pop_failure_jump back to
4489 its matching on_failure_jump, where the latter will push a
4490 failure point. The pop_failure_jump takes off failure
4491 points put on by this pop_failure_jump's matching
4492 on_failure_jump; we got through the pattern to here from the
4493 matching on_failure_jump, so didn't fail. */
4494 case pop_failure_jump:
4496 /* We need to pass separate storage for the lowest and
4497 highest registers, even though we don't care about the
4498 actual values. Otherwise, we will restore only one
4499 register from the stack, since lowest will == highest in
4500 `pop_failure_point'. */
4501 unsigned dummy_low_reg, dummy_high_reg;
4502 unsigned char *pdummy;
4505 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4506 POP_FAILURE_POINT (sdummy, pdummy,
4507 dummy_low_reg, dummy_high_reg,
4508 reg_dummy, reg_dummy, reg_info_dummy);
4510 /* Note fall through. */
4513 /* Unconditionally jump (without popping any failure points). */
4516 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4517 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4518 p += mcnt; /* Do the jump. */
4519 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4523 /* We need this opcode so we can detect where alternatives end
4524 in `group_match_null_string_p' et al. */
4526 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4527 goto unconditional_jump;
4530 /* Normally, the on_failure_jump pushes a failure point, which
4531 then gets popped at pop_failure_jump. We will end up at
4532 pop_failure_jump, also, and with a pattern of, say, `a+', we
4533 are skipping over the on_failure_jump, so we have to push
4534 something meaningless for pop_failure_jump to pop. */
4535 case dummy_failure_jump:
4536 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4537 /* It doesn't matter what we push for the string here. What
4538 the code at `fail' tests is the value for the pattern. */
4539 PUSH_FAILURE_POINT (0, 0, -2);
4540 goto unconditional_jump;
4543 /* At the end of an alternative, we need to push a dummy failure
4544 point in case we are followed by a `pop_failure_jump', because
4545 we don't want the failure point for the alternative to be
4546 popped. For example, matching `(a|ab)*' against `aab'
4547 requires that we match the `ab' alternative. */
4548 case push_dummy_failure:
4549 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4550 /* See comments just above at `dummy_failure_jump' about the
4552 PUSH_FAILURE_POINT (0, 0, -2);
4555 /* Have to succeed matching what follows at least n times.
4556 After that, handle like `on_failure_jump'. */
4558 EXTRACT_NUMBER (mcnt, p + 2);
4559 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4562 /* Originally, this is how many times we HAVE to succeed. */
4567 STORE_NUMBER_AND_INCR (p, mcnt);
4568 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4572 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4573 p[2] = (unsigned char) no_op;
4574 p[3] = (unsigned char) no_op;
4580 EXTRACT_NUMBER (mcnt, p + 2);
4581 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4583 /* Originally, this is how many times we CAN jump. */
4587 STORE_NUMBER (p + 2, mcnt);
4588 goto unconditional_jump;
4590 /* If don't have to jump any more, skip over the rest of command. */
4597 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4599 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4601 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4602 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4603 STORE_NUMBER (p1, mcnt);
4608 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4609 if (AT_WORD_BOUNDARY (d))
4614 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4615 if (AT_WORD_BOUNDARY (d))
4620 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4621 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4626 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4627 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4628 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4634 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4635 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4640 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4641 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4646 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4647 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4650 #if 0 /* not emacs19 */
4652 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4653 if (PTR_CHAR_POS ((unsigned char *) d) + 1 != point)
4656 #endif /* not emacs19 */
4659 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4664 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4668 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4670 if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
4672 SET_REGS_MATCHED ();
4676 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4678 goto matchnotsyntax;
4681 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4685 /* Can't use *d++ here; SYNTAX may be an unsafe macro. */
4687 if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
4689 SET_REGS_MATCHED ();
4692 #else /* not emacs */
4694 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4696 if (!WORDCHAR_P (d))
4698 SET_REGS_MATCHED ();
4703 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4707 SET_REGS_MATCHED ();
4710 #endif /* not emacs */
4715 continue; /* Successfully executed one pattern command; keep going. */
4718 /* We goto here if a matching operation fails. */
4720 if (!FAIL_STACK_EMPTY ())
4721 { /* A restart point is known. Restore to that state. */
4722 DEBUG_PRINT1 ("\nFAIL:\n");
4723 POP_FAILURE_POINT (d, p,
4724 lowest_active_reg, highest_active_reg,
4725 regstart, regend, reg_info);
4727 /* If this failure point is a dummy, try the next one. */
4731 /* If we failed to the end of the pattern, don't examine *p. */
4735 boolean is_a_jump_n = false;
4737 /* If failed to a backwards jump that's part of a repetition
4738 loop, need to pop this failure point and use the next one. */
4739 switch ((re_opcode_t) *p)
4743 case maybe_pop_jump:
4744 case pop_failure_jump:
4747 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4750 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4752 && (re_opcode_t) *p1 == on_failure_jump))
4760 if (d >= string1 && d <= end1)
4764 break; /* Matching at this starting point really fails. */
4768 goto restore_best_regs;
4772 return -1; /* Failure to match. */
4775 /* Subroutine definitions for re_match_2. */
4778 /* We are passed P pointing to a register number after a start_memory.
4780 Return true if the pattern up to the corresponding stop_memory can
4781 match the empty string, and false otherwise.
4783 If we find the matching stop_memory, sets P to point to one past its number.
4784 Otherwise, sets P to an undefined byte less than or equal to END.
4786 We don't handle duplicates properly (yet). */
4789 group_match_null_string_p (p, end, reg_info)
4790 unsigned char **p, *end;
4791 register_info_type *reg_info;
4794 /* Point to after the args to the start_memory. */
4795 unsigned char *p1 = *p + 2;
4799 /* Skip over opcodes that can match nothing, and return true or
4800 false, as appropriate, when we get to one that can't, or to the
4801 matching stop_memory. */
4803 switch ((re_opcode_t) *p1)
4805 /* Could be either a loop or a series of alternatives. */
4806 case on_failure_jump:
4808 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4810 /* If the next operation is not a jump backwards in the
4815 /* Go through the on_failure_jumps of the alternatives,
4816 seeing if any of the alternatives cannot match nothing.
4817 The last alternative starts with only a jump,
4818 whereas the rest start with on_failure_jump and end
4819 with a jump, e.g., here is the pattern for `a|b|c':
4821 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4822 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4825 So, we have to first go through the first (n-1)
4826 alternatives and then deal with the last one separately. */
4829 /* Deal with the first (n-1) alternatives, which start
4830 with an on_failure_jump (see above) that jumps to right
4831 past a jump_past_alt. */
4833 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4835 /* `mcnt' holds how many bytes long the alternative
4836 is, including the ending `jump_past_alt' and
4839 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4843 /* Move to right after this alternative, including the
4847 /* Break if it's the beginning of an n-th alternative
4848 that doesn't begin with an on_failure_jump. */
4849 if ((re_opcode_t) *p1 != on_failure_jump)
4852 /* Still have to check that it's not an n-th
4853 alternative that starts with an on_failure_jump. */
4855 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4856 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4858 /* Get to the beginning of the n-th alternative. */
4864 /* Deal with the last alternative: go back and get number
4865 of the `jump_past_alt' just before it. `mcnt' contains
4866 the length of the alternative. */
4867 EXTRACT_NUMBER (mcnt, p1 - 2);
4869 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4872 p1 += mcnt; /* Get past the n-th alternative. */
4878 assert (p1[1] == **p);
4884 if (!common_op_match_null_string_p (&p1, end, reg_info))
4887 } /* while p1 < end */
4890 } /* group_match_null_string_p */
4893 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4894 It expects P to be the first byte of a single alternative and END one
4895 byte past the last. The alternative can contain groups. */
4898 alt_match_null_string_p (p, end, reg_info)
4899 unsigned char *p, *end;
4900 register_info_type *reg_info;
4903 unsigned char *p1 = p;
4907 /* Skip over opcodes that can match nothing, and break when we get
4908 to one that can't. */
4910 switch ((re_opcode_t) *p1)
4913 case on_failure_jump:
4915 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4920 if (!common_op_match_null_string_p (&p1, end, reg_info))
4923 } /* while p1 < end */
4926 } /* alt_match_null_string_p */
4929 /* Deals with the ops common to group_match_null_string_p and
4930 alt_match_null_string_p.
4932 Sets P to one after the op and its arguments, if any. */
4935 common_op_match_null_string_p (p, end, reg_info)
4936 unsigned char **p, *end;
4937 register_info_type *reg_info;
4942 unsigned char *p1 = *p;
4944 switch ((re_opcode_t) *p1++)
4964 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
4965 ret = group_match_null_string_p (&p1, end, reg_info);
4967 /* Have to set this here in case we're checking a group which
4968 contains a group and a back reference to it. */
4970 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
4971 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
4977 /* If this is an optimized succeed_n for zero times, make the jump. */
4979 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4987 /* Get to the number of times to succeed. */
4989 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4994 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
5002 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
5010 /* All other opcodes mean we cannot match the empty string. */
5016 } /* common_op_match_null_string_p */
5019 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
5020 bytes; nonzero otherwise. */
5023 bcmp_translate (s1, s2, len, translate)
5024 unsigned char *s1, *s2;
5028 register unsigned char *p1 = s1, *p2 = s2;
5031 if (translate[*p1++] != translate[*p2++]) return 1;
5037 /* Entry points for GNU code. */
5039 /* re_compile_pattern is the GNU regular expression compiler: it
5040 compiles PATTERN (of length SIZE) and puts the result in BUFP.
5041 Returns 0 if the pattern was valid, otherwise an error string.
5043 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
5044 are set in BUFP on entry.
5046 We call regex_compile to do the actual compilation. */
5049 re_compile_pattern (pattern, length, bufp)
5050 const char *pattern;
5052 struct re_pattern_buffer *bufp;
5056 /* GNU code is written to assume at least RE_NREGS registers will be set
5057 (and at least one extra will be -1). */
5058 bufp->regs_allocated = REGS_UNALLOCATED;
5060 /* And GNU code determines whether or not to get register information
5061 by passing null for the REGS argument to re_match, etc., not by
5065 /* Match anchors at newline. */
5066 bufp->newline_anchor = 1;
5068 ret = regex_compile (pattern, length, re_syntax_options, bufp);
5072 return gettext (re_error_msgid[(int) ret]);
5075 /* Entry points compatible with 4.2 BSD regex library. We don't define
5076 them unless specifically requested. */
5078 #ifdef _REGEX_RE_COMP
5080 /* BSD has one and only one pattern buffer. */
5081 static struct re_pattern_buffer re_comp_buf;
5091 if (!re_comp_buf.buffer)
5092 return gettext ("No previous regular expression");
5096 if (!re_comp_buf.buffer)
5098 re_comp_buf.buffer = (unsigned char *) malloc (200);
5099 if (re_comp_buf.buffer == NULL)
5100 return gettext (re_error_msgid[(int) REG_ESPACE]);
5101 re_comp_buf.allocated = 200;
5103 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
5104 if (re_comp_buf.fastmap == NULL)
5105 return gettext (re_error_msgid[(int) REG_ESPACE]);
5108 /* Since `re_exec' always passes NULL for the `regs' argument, we
5109 don't need to initialize the pattern buffer fields which affect it. */
5111 /* Match anchors at newlines. */
5112 re_comp_buf.newline_anchor = 1;
5114 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
5119 /* Yes, we're discarding `const' here if !HAVE_LIBINTL. */
5120 return (char *) gettext (re_error_msgid[(int) ret]);
5128 const int len = strlen (s);
5130 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
5132 #endif /* _REGEX_RE_COMP */
5134 /* POSIX.2 functions. Don't define these for Emacs. */
5138 /* regcomp takes a regular expression as a string and compiles it.
5140 PREG is a regex_t *. We do not expect any fields to be initialized,
5141 since POSIX says we shouldn't. Thus, we set
5143 `buffer' to the compiled pattern;
5144 `used' to the length of the compiled pattern;
5145 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
5146 REG_EXTENDED bit in CFLAGS is set; otherwise, to
5147 RE_SYNTAX_POSIX_BASIC;
5148 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
5149 `fastmap' and `fastmap_accurate' to zero;
5150 `re_nsub' to the number of subexpressions in PATTERN.
5152 PATTERN is the address of the pattern string.
5154 CFLAGS is a series of bits which affect compilation.
5156 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
5157 use POSIX basic syntax.
5159 If REG_NEWLINE is set, then . and [^...] don't match newline.
5160 Also, regexec will try a match beginning after every newline.
5162 If REG_ICASE is set, then we considers upper- and lowercase
5163 versions of letters to be equivalent when matching.
5165 If REG_NOSUB is set, then when PREG is passed to regexec, that
5166 routine will report only success or failure, and nothing about the
5169 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
5170 the return codes and their meanings.) */
5173 regcomp (preg, pattern, cflags)
5175 const char *pattern;
5180 = (cflags & REG_EXTENDED) ?
5181 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
5183 /* regex_compile will allocate the space for the compiled pattern. */
5185 preg->allocated = 0;
5188 /* Don't bother to use a fastmap when searching. This simplifies the
5189 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
5190 characters after newlines into the fastmap. This way, we just try
5194 if (cflags & REG_ICASE)
5198 preg->translate = (char *) malloc (CHAR_SET_SIZE);
5199 if (preg->translate == NULL)
5200 return (int) REG_ESPACE;
5202 /* Map uppercase characters to corresponding lowercase ones. */
5203 for (i = 0; i < CHAR_SET_SIZE; i++)
5204 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
5207 preg->translate = NULL;
5209 /* If REG_NEWLINE is set, newlines are treated differently. */
5210 if (cflags & REG_NEWLINE)
5211 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
5212 syntax &= ~RE_DOT_NEWLINE;
5213 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
5214 /* It also changes the matching behavior. */
5215 preg->newline_anchor = 1;
5218 preg->newline_anchor = 0;
5220 preg->no_sub = !!(cflags & REG_NOSUB);
5222 /* POSIX says a null character in the pattern terminates it, so we
5223 can use strlen here in compiling the pattern. */
5224 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
5226 /* POSIX doesn't distinguish between an unmatched open-group and an
5227 unmatched close-group: both are REG_EPAREN. */
5228 if (ret == REG_ERPAREN) ret = REG_EPAREN;
5234 /* regexec searches for a given pattern, specified by PREG, in the
5237 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
5238 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
5239 least NMATCH elements, and we set them to the offsets of the
5240 corresponding matched substrings.
5242 EFLAGS specifies `execution flags' which affect matching: if
5243 REG_NOTBOL is set, then ^ does not match at the beginning of the
5244 string; if REG_NOTEOL is set, then $ does not match at the end.
5246 We return 0 if we find a match and REG_NOMATCH if not. */
5249 regexec (preg, string, nmatch, pmatch, eflags)
5250 const regex_t *preg;
5253 regmatch_t pmatch[];
5257 struct re_registers regs;
5258 regex_t private_preg;
5259 int len = strlen (string);
5260 boolean want_reg_info = !preg->no_sub && nmatch > 0;
5262 private_preg = *preg;
5264 private_preg.not_bol = !!(eflags & REG_NOTBOL);
5265 private_preg.not_eol = !!(eflags & REG_NOTEOL);
5267 /* The user has told us exactly how many registers to return
5268 information about, via `nmatch'. We have to pass that on to the
5269 matching routines. */
5270 private_preg.regs_allocated = REGS_FIXED;
5274 regs.num_regs = nmatch;
5275 regs.start = TALLOC (nmatch, regoff_t);
5276 regs.end = TALLOC (nmatch, regoff_t);
5277 if (regs.start == NULL || regs.end == NULL)
5278 return (int) REG_NOMATCH;
5281 /* Perform the searching operation. */
5282 ret = re_search (&private_preg, string, len,
5283 /* start: */ 0, /* range: */ len,
5284 want_reg_info ? ®s : (struct re_registers *) 0);
5286 /* Copy the register information to the POSIX structure. */
5293 for (r = 0; r < nmatch; r++)
5295 pmatch[r].rm_so = regs.start[r];
5296 pmatch[r].rm_eo = regs.end[r];
5300 /* If we needed the temporary register info, free the space now. */
5305 /* We want zero return to mean success, unlike `re_search'. */
5306 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5310 /* Returns a message corresponding to an error code, ERRCODE, returned
5311 from either regcomp or regexec. We don't use PREG here. */
5314 regerror (errcode, preg, errbuf, errbuf_size)
5316 const regex_t *preg;
5324 || errcode >= (sizeof (re_error_msgid) / sizeof (re_error_msgid[0])))
5325 /* Only error codes returned by the rest of the code should be passed
5326 to this routine. If we are given anything else, or if other regex
5327 code generates an invalid error code, then the program has a bug.
5328 Dump core so we can fix it. */
5331 msg = gettext (re_error_msgid[errcode]);
5333 msg_size = strlen (msg) + 1; /* Includes the null. */
5335 if (errbuf_size != 0)
5337 if (msg_size > errbuf_size)
5339 strncpy (errbuf, msg, errbuf_size - 1);
5340 errbuf[errbuf_size - 1] = 0;
5343 strcpy (errbuf, msg);
5350 /* Free dynamically allocated space used by PREG. */
5356 if (preg->buffer != NULL)
5357 free (preg->buffer);
5358 preg->buffer = NULL;
5360 preg->allocated = 0;
5363 if (preg->fastmap != NULL)
5364 free (preg->fastmap);
5365 preg->fastmap = NULL;
5366 preg->fastmap_accurate = 0;
5368 if (preg->translate != NULL)
5369 free (preg->translate);
5370 preg->translate = NULL;
5373 #endif /* not emacs */
5377 make-backup-files: t
5379 trim-versions-without-asking: nil