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 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)
29 /* We need this for `regex.h', and perhaps for the Emacs include files. */
30 #include <sys/types.h>
36 /* The `emacs' switch turns on certain matching commands
37 that make sense only in Emacs. */
44 /* Emacs uses `NULL' as a predicate. */
49 /* We used to test for `BSTRING' here, but only GCC and Emacs define
50 `BSTRING', as far as I know, and neither of them use this code. */
51 #if HAVE_STRING_H || STDC_HEADERS
54 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
57 #define bcopy(s, d, n) memcpy ((d), (s), (n))
60 #define bzero(s, n) memset ((s), 0, (n))
74 /* Define the syntax stuff for \<, \>, etc. */
76 /* This must be nonzero for the wordchar and notwordchar pattern
77 commands in re_match_2. */
84 extern char *re_syntax_table;
86 #else /* not SYNTAX_TABLE */
88 /* How many characters in the character set. */
89 #define CHAR_SET_SIZE 256
91 static char re_syntax_table[CHAR_SET_SIZE];
102 bzero (re_syntax_table, sizeof re_syntax_table);
104 for (c = 'a'; c <= 'z'; c++)
105 re_syntax_table[c] = Sword;
107 for (c = 'A'; c <= 'Z'; c++)
108 re_syntax_table[c] = Sword;
110 for (c = '0'; c <= '9'; c++)
111 re_syntax_table[c] = Sword;
113 re_syntax_table['_'] = Sword;
118 #endif /* not SYNTAX_TABLE */
120 #define SYNTAX(c) re_syntax_table[c]
122 #endif /* not emacs */
124 /* Get the interface, including the syntax bits. */
127 /* isalpha etc. are used for the character classes. */
130 /* Jim Meyering writes:
132 "... Some ctype macros are valid only for character codes that
133 isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
134 using /bin/cc or gcc but without giving an ansi option). So, all
135 ctype uses should be through macros like ISPRINT... If
136 STDC_HEADERS is defined, then autoconf has verified that the ctype
137 macros don't need to be guarded with references to isascii. ...
138 Defining isascii to 1 should let any compiler worth its salt
139 eliminate the && through constant folding." */
140 #if ! defined (isascii) || defined (STDC_HEADERS)
146 #define ISBLANK(c) (isascii (c) && isblank (c))
148 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
151 #define ISGRAPH(c) (isascii (c) && isgraph (c))
153 #define ISGRAPH(c) (isascii (c) && isprint (c) && !isspace (c))
156 #define ISPRINT(c) (isascii (c) && isprint (c))
157 #define ISDIGIT(c) (isascii (c) && isdigit (c))
158 #define ISALNUM(c) (isascii (c) && isalnum (c))
159 #define ISALPHA(c) (isascii (c) && isalpha (c))
160 #define ISCNTRL(c) (isascii (c) && iscntrl (c))
161 #define ISLOWER(c) (isascii (c) && islower (c))
162 #define ISPUNCT(c) (isascii (c) && ispunct (c))
163 #define ISSPACE(c) (isascii (c) && isspace (c))
164 #define ISUPPER(c) (isascii (c) && isupper (c))
165 #define ISXDIGIT(c) (isascii (c) && isxdigit (c))
171 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
172 since ours (we hope) works properly with all combinations of
173 machines, compilers, `char' and `unsigned char' argument types.
174 (Per Bothner suggested the basic approach.) */
175 #undef SIGN_EXTEND_CHAR
177 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
178 #else /* not __STDC__ */
179 /* As in Harbison and Steele. */
180 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
183 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
184 use `alloca' instead of `malloc'. This is because using malloc in
185 re_search* or re_match* could cause memory leaks when C-g is used in
186 Emacs; also, malloc is slower and causes storage fragmentation. On
187 the other hand, malloc is more portable, and easier to debug.
189 Because we sometimes use alloca, some routines have to be macros,
190 not functions -- `alloca'-allocated space disappears at the end of the
191 function it is called in. */
195 #define REGEX_ALLOCATE malloc
196 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
198 #else /* not REGEX_MALLOC */
200 /* Emacs already defines alloca, sometimes. */
203 /* Make alloca work the best possible way. */
205 #define alloca __builtin_alloca
206 #else /* not __GNUC__ */
209 #else /* not __GNUC__ or HAVE_ALLOCA_H */
210 #ifndef _AIX /* Already did AIX, up at the top. */
212 #endif /* not _AIX */
213 #endif /* not HAVE_ALLOCA_H */
214 #endif /* not __GNUC__ */
216 #endif /* not alloca */
218 #define REGEX_ALLOCATE alloca
220 /* Assumes a `char *destination' variable. */
221 #define REGEX_REALLOCATE(source, osize, nsize) \
222 (destination = (char *) alloca (nsize), \
223 bcopy (source, destination, osize), \
226 #endif /* not REGEX_MALLOC */
229 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
230 `string1' or just past its end. This works if PTR is NULL, which is
232 #define FIRST_STRING_P(ptr) \
233 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
235 /* (Re)Allocate N items of type T using malloc, or fail. */
236 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
237 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
238 #define RETALLOC_IF(addr, n, t) \
239 if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
240 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
242 #define BYTEWIDTH 8 /* In bits. */
244 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
246 #define MAX(a, b) ((a) > (b) ? (a) : (b))
247 #define MIN(a, b) ((a) < (b) ? (a) : (b))
249 typedef char boolean;
253 /* These are the command codes that appear in compiled regular
254 expressions. Some opcodes are followed by argument bytes. A
255 command code can specify any interpretation whatsoever for its
256 arguments. Zero bytes may appear in the compiled regular expression.
258 The value of `exactn' is needed in search.c (search_buffer) in Emacs.
259 So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of
260 `exactn' we use here must also be 1. */
266 /* Followed by one byte giving n, then by n literal bytes. */
269 /* Matches any (more or less) character. */
272 /* Matches any one char belonging to specified set. First
273 following byte is number of bitmap bytes. Then come bytes
274 for a bitmap saying which chars are in. Bits in each byte
275 are ordered low-bit-first. A character is in the set if its
276 bit is 1. A character too large to have a bit in the map is
277 automatically not in the set. */
280 /* Same parameters as charset, but match any character that is
281 not one of those specified. */
284 /* Start remembering the text that is matched, for storing in a
285 register. Followed by one byte with the register number, in
286 the range 0 to one less than the pattern buffer's re_nsub
287 field. Then followed by one byte with the number of groups
288 inner to this one. (This last has to be part of the
289 start_memory only because we need it in the on_failure_jump
293 /* Stop remembering the text that is matched and store it in a
294 memory register. Followed by one byte with the register
295 number, in the range 0 to one less than `re_nsub' in the
296 pattern buffer, and one byte with the number of inner groups,
297 just like `start_memory'. (We need the number of inner
298 groups here because we don't have any easy way of finding the
299 corresponding start_memory when we're at a stop_memory.) */
302 /* Match a duplicate of something remembered. Followed by one
303 byte containing the register number. */
306 /* Fail unless at beginning of line. */
309 /* Fail unless at end of line. */
312 /* Succeeds if at beginning of buffer (if emacs) or at beginning
313 of string to be matched (if not). */
316 /* Analogously, for end of buffer/string. */
319 /* Followed by two byte relative address to which to jump. */
322 /* Same as jump, but marks the end of an alternative. */
325 /* Followed by two-byte relative address of place to resume at
326 in case of failure. */
329 /* Like on_failure_jump, but pushes a placeholder instead of the
330 current string position when executed. */
331 on_failure_keep_string_jump,
333 /* Throw away latest failure point and then jump to following
334 two-byte relative address. */
337 /* Change to pop_failure_jump if know won't have to backtrack to
338 match; otherwise change to jump. This is used to jump
339 back to the beginning of a repeat. If what follows this jump
340 clearly won't match what the repeat does, such that we can be
341 sure that there is no use backtracking out of repetitions
342 already matched, then we change it to a pop_failure_jump.
343 Followed by two-byte address. */
346 /* Jump to following two-byte address, and push a dummy failure
347 point. This failure point will be thrown away if an attempt
348 is made to use it for a failure. A `+' construct makes this
349 before the first repeat. Also used as an intermediary kind
350 of jump when compiling an alternative. */
353 /* Push a dummy failure point and continue. Used at the end of
357 /* Followed by two-byte relative address and two-byte number n.
358 After matching N times, jump to the address upon failure. */
361 /* Followed by two-byte relative address, and two-byte number n.
362 Jump to the address N times, then fail. */
365 /* Set the following two-byte relative address to the
366 subsequent two-byte number. The address *includes* the two
370 wordchar, /* Matches any word-constituent character. */
371 notwordchar, /* Matches any char that is not a word-constituent. */
373 wordbeg, /* Succeeds if at word beginning. */
374 wordend, /* Succeeds if at word end. */
376 wordbound, /* Succeeds if at a word boundary. */
377 notwordbound /* Succeeds if not at a word boundary. */
380 ,before_dot, /* Succeeds if before point. */
381 at_dot, /* Succeeds if at point. */
382 after_dot, /* Succeeds if after point. */
384 /* Matches any character whose syntax is specified. Followed by
385 a byte which contains a syntax code, e.g., Sword. */
388 /* Matches any character whose syntax is not that specified. */
393 /* Common operations on the compiled pattern. */
395 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
397 #define STORE_NUMBER(destination, number) \
399 (destination)[0] = (number) & 0377; \
400 (destination)[1] = (number) >> 8; \
403 /* Same as STORE_NUMBER, except increment DESTINATION to
404 the byte after where the number is stored. Therefore, DESTINATION
405 must be an lvalue. */
407 #define STORE_NUMBER_AND_INCR(destination, number) \
409 STORE_NUMBER (destination, number); \
410 (destination) += 2; \
413 /* Put into DESTINATION a number stored in two contiguous bytes starting
416 #define EXTRACT_NUMBER(destination, source) \
418 (destination) = *(source) & 0377; \
419 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
424 extract_number (dest, source)
426 unsigned char *source;
428 int temp = SIGN_EXTEND_CHAR (*(source + 1));
429 *dest = *source & 0377;
433 #ifndef EXTRACT_MACROS /* To debug the macros. */
434 #undef EXTRACT_NUMBER
435 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
436 #endif /* not EXTRACT_MACROS */
440 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
441 SOURCE must be an lvalue. */
443 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
445 EXTRACT_NUMBER (destination, source); \
451 extract_number_and_incr (destination, source)
453 unsigned char **source;
455 extract_number (destination, *source);
459 #ifndef EXTRACT_MACROS
460 #undef EXTRACT_NUMBER_AND_INCR
461 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
462 extract_number_and_incr (&dest, &src)
463 #endif /* not EXTRACT_MACROS */
467 /* If DEBUG is defined, Regex prints many voluminous messages about what
468 it is doing (if the variable `debug' is nonzero). If linked with the
469 main program in `iregex.c', you can enter patterns and strings
470 interactively. And if linked with the main program in `main.c' and
471 the other test files, you can run the already-written tests. */
475 /* We use standard I/O for debugging. */
478 /* It is useful to test things that ``must'' be true when debugging. */
481 static int debug = 0;
483 #define DEBUG_STATEMENT(e) e
484 #define DEBUG_PRINT1(x) if (debug) printf (x)
485 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
486 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
487 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
488 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
489 if (debug) print_partial_compiled_pattern (s, e)
490 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
491 if (debug) print_double_string (w, s1, sz1, s2, sz2)
494 extern void printchar ();
496 /* Print the fastmap in human-readable form. */
499 print_fastmap (fastmap)
502 unsigned was_a_range = 0;
505 while (i < (1 << BYTEWIDTH))
511 while (i < (1 << BYTEWIDTH) && fastmap[i])
527 /* Print a compiled pattern string in human-readable form, starting at
528 the START pointer into it and ending just before the pointer END. */
531 print_partial_compiled_pattern (start, end)
532 unsigned char *start;
536 unsigned char *p = start;
537 unsigned char *pend = end;
545 /* Loop over pattern commands. */
548 printf ("%d:\t", p - start);
550 switch ((re_opcode_t) *p++)
558 printf ("/exactn/%d", mcnt);
569 printf ("/start_memory/%d/%d", mcnt, *p++);
574 printf ("/stop_memory/%d/%d", mcnt, *p++);
578 printf ("/duplicate/%d", *p++);
588 register int c, last = -100;
589 register int in_range = 0;
591 printf ("/charset [%s",
592 (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
594 assert (p + *p < pend);
596 for (c = 0; c < 256; c++)
598 && (p[1 + (c/8)] & (1 << (c % 8))))
600 /* Are we starting a range? */
601 if (last + 1 == c && ! in_range)
606 /* Have we broken a range? */
607 else if (last + 1 != c && in_range)
636 case on_failure_jump:
637 extract_number_and_incr (&mcnt, &p);
638 printf ("/on_failure_jump to %d", p + mcnt - start);
641 case on_failure_keep_string_jump:
642 extract_number_and_incr (&mcnt, &p);
643 printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
646 case dummy_failure_jump:
647 extract_number_and_incr (&mcnt, &p);
648 printf ("/dummy_failure_jump to %d", p + mcnt - start);
651 case push_dummy_failure:
652 printf ("/push_dummy_failure");
656 extract_number_and_incr (&mcnt, &p);
657 printf ("/maybe_pop_jump to %d", p + mcnt - start);
660 case pop_failure_jump:
661 extract_number_and_incr (&mcnt, &p);
662 printf ("/pop_failure_jump to %d", p + mcnt - start);
666 extract_number_and_incr (&mcnt, &p);
667 printf ("/jump_past_alt to %d", p + mcnt - start);
671 extract_number_and_incr (&mcnt, &p);
672 printf ("/jump to %d", p + mcnt - start);
676 extract_number_and_incr (&mcnt, &p);
677 extract_number_and_incr (&mcnt2, &p);
678 printf ("/succeed_n to %d, %d times", p + mcnt - start, mcnt2);
682 extract_number_and_incr (&mcnt, &p);
683 extract_number_and_incr (&mcnt2, &p);
684 printf ("/jump_n to %d, %d times", p + mcnt - start, mcnt2);
688 extract_number_and_incr (&mcnt, &p);
689 extract_number_and_incr (&mcnt2, &p);
690 printf ("/set_number_at location %d to %d", p + mcnt - start, mcnt2);
694 printf ("/wordbound");
698 printf ("/notwordbound");
710 printf ("/before_dot");
718 printf ("/after_dot");
722 printf ("/syntaxspec");
724 printf ("/%d", mcnt);
728 printf ("/notsyntaxspec");
730 printf ("/%d", mcnt);
735 printf ("/wordchar");
739 printf ("/notwordchar");
751 printf ("?%d", *(p-1));
757 printf ("%d:\tend of pattern.\n", p - start);
762 print_compiled_pattern (bufp)
763 struct re_pattern_buffer *bufp;
765 unsigned char *buffer = bufp->buffer;
767 print_partial_compiled_pattern (buffer, buffer + bufp->used);
768 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
770 if (bufp->fastmap_accurate && bufp->fastmap)
772 printf ("fastmap: ");
773 print_fastmap (bufp->fastmap);
776 printf ("re_nsub: %d\t", bufp->re_nsub);
777 printf ("regs_alloc: %d\t", bufp->regs_allocated);
778 printf ("can_be_null: %d\t", bufp->can_be_null);
779 printf ("newline_anchor: %d\n", bufp->newline_anchor);
780 printf ("no_sub: %d\t", bufp->no_sub);
781 printf ("not_bol: %d\t", bufp->not_bol);
782 printf ("not_eol: %d\t", bufp->not_eol);
783 printf ("syntax: %d\n", bufp->syntax);
784 /* Perhaps we should print the translate table? */
789 print_double_string (where, string1, size1, string2, size2)
802 if (FIRST_STRING_P (where))
804 for (this_char = where - string1; this_char < size1; this_char++)
805 printchar (string1[this_char]);
810 for (this_char = where - string2; this_char < size2; this_char++)
811 printchar (string2[this_char]);
815 #else /* not DEBUG */
820 #define DEBUG_STATEMENT(e)
821 #define DEBUG_PRINT1(x)
822 #define DEBUG_PRINT2(x1, x2)
823 #define DEBUG_PRINT3(x1, x2, x3)
824 #define DEBUG_PRINT4(x1, x2, x3, x4)
825 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
826 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
828 #endif /* not DEBUG */
830 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
831 also be assigned to arbitrarily: each pattern buffer stores its own
832 syntax, so it can be changed between regex compilations. */
833 reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS;
836 /* Specify the precise syntax of regexps for compilation. This provides
837 for compatibility for various utilities which historically have
838 different, incompatible syntaxes.
840 The argument SYNTAX is a bit mask comprised of the various bits
841 defined in regex.h. We return the old syntax. */
844 re_set_syntax (syntax)
847 reg_syntax_t ret = re_syntax_options;
849 re_syntax_options = syntax;
853 /* This table gives an error message for each of the error codes listed
854 in regex.h. Obviously the order here has to be same as there. */
856 static const char *re_error_msg[] =
857 { NULL, /* REG_NOERROR */
858 "No match", /* REG_NOMATCH */
859 "Invalid regular expression", /* REG_BADPAT */
860 "Invalid collation character", /* REG_ECOLLATE */
861 "Invalid character class name", /* REG_ECTYPE */
862 "Trailing backslash", /* REG_EESCAPE */
863 "Invalid back reference", /* REG_ESUBREG */
864 "Unmatched [ or [^", /* REG_EBRACK */
865 "Unmatched ( or \\(", /* REG_EPAREN */
866 "Unmatched \\{", /* REG_EBRACE */
867 "Invalid content of \\{\\}", /* REG_BADBR */
868 "Invalid range end", /* REG_ERANGE */
869 "Memory exhausted", /* REG_ESPACE */
870 "Invalid preceding regular expression", /* REG_BADRPT */
871 "Premature end of regular expression", /* REG_EEND */
872 "Regular expression too big", /* REG_ESIZE */
873 "Unmatched ) or \\)", /* REG_ERPAREN */
876 /* Avoiding alloca during matching, to placate r_alloc. */
878 /* Define MATCH_MAY_ALLOCATE if we need to make sure that the
879 searching and matching functions should not call alloca. On some
880 systems, alloca is implemented in terms of malloc, and if we're
881 using the relocating allocator routines, then malloc could cause a
882 relocation, which might (if the strings being searched are in the
883 ralloc heap) shift the data out from underneath the regexp
886 /* Normally, this is fine. */
887 #define MATCH_MAY_ALLOCATE
889 /* But under some circumstances, it's not. */
890 #if defined (REL_ALLOC) && defined (C_ALLOCA)
891 #undef MATCH_MAY_ALLOCATE
895 /* Failure stack declarations and macros; both re_compile_fastmap and
896 re_match_2 use a failure stack. These have to be macros because of
900 /* Number of failure points for which to initially allocate space
901 when matching. If this number is exceeded, we allocate more
902 space, so it is not a hard limit. */
903 #ifndef INIT_FAILURE_ALLOC
904 #define INIT_FAILURE_ALLOC 5
907 /* Roughly the maximum number of failure points on the stack. Would be
908 exactly that if always used MAX_FAILURE_SPACE each time we failed.
909 This is a variable only so users of regex can assign to it; we never
910 change it ourselves. */
911 int re_max_failures = 2000;
913 typedef const unsigned char *fail_stack_elt_t;
917 fail_stack_elt_t *stack;
919 unsigned avail; /* Offset of next open position. */
922 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
923 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
924 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
925 #define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail])
928 /* Initialize `fail_stack'. Do `return -2' if the alloc fails. */
930 #ifdef MATCH_MAY_ALLOCATE
931 #define INIT_FAIL_STACK() \
933 fail_stack.stack = (fail_stack_elt_t *) \
934 REGEX_ALLOCATE (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
936 if (fail_stack.stack == NULL) \
939 fail_stack.size = INIT_FAILURE_ALLOC; \
940 fail_stack.avail = 0; \
943 #define INIT_FAIL_STACK() \
945 fail_stack.avail = 0; \
950 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
952 Return 1 if succeeds, and 0 if either ran out of memory
953 allocating space for it or it was already too large.
955 REGEX_REALLOCATE requires `destination' be declared. */
957 #define DOUBLE_FAIL_STACK(fail_stack) \
958 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
960 : ((fail_stack).stack = (fail_stack_elt_t *) \
961 REGEX_REALLOCATE ((fail_stack).stack, \
962 (fail_stack).size * sizeof (fail_stack_elt_t), \
963 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
965 (fail_stack).stack == NULL \
967 : ((fail_stack).size <<= 1, \
971 /* Push PATTERN_OP on FAIL_STACK.
973 Return 1 if was able to do so and 0 if ran out of memory allocating
975 #define PUSH_PATTERN_OP(pattern_op, fail_stack) \
976 ((FAIL_STACK_FULL () \
977 && !DOUBLE_FAIL_STACK (fail_stack)) \
979 : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \
982 /* This pushes an item onto the failure stack. Must be a four-byte
983 value. Assumes the variable `fail_stack'. Probably should only
984 be called from within `PUSH_FAILURE_POINT'. */
985 #define PUSH_FAILURE_ITEM(item) \
986 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) item
988 /* The complement operation. Assumes `fail_stack' is nonempty. */
989 #define POP_FAILURE_ITEM() fail_stack.stack[--fail_stack.avail]
991 /* Used to omit pushing failure point id's when we're not debugging. */
993 #define DEBUG_PUSH PUSH_FAILURE_ITEM
994 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_ITEM ()
996 #define DEBUG_PUSH(item)
997 #define DEBUG_POP(item_addr)
1001 /* Push the information about the state we will need
1002 if we ever fail back to it.
1004 Requires variables fail_stack, regstart, regend, reg_info, and
1005 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
1008 Does `return FAILURE_CODE' if runs out of memory. */
1010 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
1012 char *destination; \
1013 /* Must be int, so when we don't save any registers, the arithmetic \
1014 of 0 + -1 isn't done as unsigned. */ \
1017 DEBUG_STATEMENT (failure_id++); \
1018 DEBUG_STATEMENT (nfailure_points_pushed++); \
1019 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
1020 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
1021 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
1023 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
1024 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
1026 /* Ensure we have enough space allocated for what we will push. */ \
1027 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
1029 if (!DOUBLE_FAIL_STACK (fail_stack)) \
1030 return failure_code; \
1032 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
1033 (fail_stack).size); \
1034 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
1037 /* Push the info, starting with the registers. */ \
1038 DEBUG_PRINT1 ("\n"); \
1040 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
1043 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
1044 DEBUG_STATEMENT (num_regs_pushed++); \
1046 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1047 PUSH_FAILURE_ITEM (regstart[this_reg]); \
1049 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1050 PUSH_FAILURE_ITEM (regend[this_reg]); \
1052 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
1053 DEBUG_PRINT2 (" match_null=%d", \
1054 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
1055 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
1056 DEBUG_PRINT2 (" matched_something=%d", \
1057 MATCHED_SOMETHING (reg_info[this_reg])); \
1058 DEBUG_PRINT2 (" ever_matched=%d", \
1059 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
1060 DEBUG_PRINT1 ("\n"); \
1061 PUSH_FAILURE_ITEM (reg_info[this_reg].word); \
1064 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
1065 PUSH_FAILURE_ITEM (lowest_active_reg); \
1067 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
1068 PUSH_FAILURE_ITEM (highest_active_reg); \
1070 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
1071 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
1072 PUSH_FAILURE_ITEM (pattern_place); \
1074 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
1075 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
1077 DEBUG_PRINT1 ("'\n"); \
1078 PUSH_FAILURE_ITEM (string_place); \
1080 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
1081 DEBUG_PUSH (failure_id); \
1084 /* This is the number of items that are pushed and popped on the stack
1085 for each register. */
1086 #define NUM_REG_ITEMS 3
1088 /* Individual items aside from the registers. */
1090 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
1092 #define NUM_NONREG_ITEMS 4
1095 /* We push at most this many items on the stack. */
1096 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
1098 /* We actually push this many items. */
1099 #define NUM_FAILURE_ITEMS \
1100 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
1103 /* How many items can still be added to the stack without overflowing it. */
1104 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
1107 /* Pops what PUSH_FAIL_STACK pushes.
1109 We restore into the parameters, all of which should be lvalues:
1110 STR -- the saved data position.
1111 PAT -- the saved pattern position.
1112 LOW_REG, HIGH_REG -- the highest and lowest active registers.
1113 REGSTART, REGEND -- arrays of string positions.
1114 REG_INFO -- array of information about each subexpression.
1116 Also assumes the variables `fail_stack' and (if debugging), `bufp',
1117 `pend', `string1', `size1', `string2', and `size2'. */
1119 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
1121 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
1123 const unsigned char *string_temp; \
1125 assert (!FAIL_STACK_EMPTY ()); \
1127 /* Remove failure points and point to how many regs pushed. */ \
1128 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
1129 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
1130 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
1132 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
1134 DEBUG_POP (&failure_id); \
1135 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
1137 /* If the saved string location is NULL, it came from an \
1138 on_failure_keep_string_jump opcode, and we want to throw away the \
1139 saved NULL, thus retaining our current position in the string. */ \
1140 string_temp = POP_FAILURE_ITEM (); \
1141 if (string_temp != NULL) \
1142 str = (const char *) string_temp; \
1144 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
1145 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
1146 DEBUG_PRINT1 ("'\n"); \
1148 pat = (unsigned char *) POP_FAILURE_ITEM (); \
1149 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
1150 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
1152 /* Restore register info. */ \
1153 high_reg = (unsigned) POP_FAILURE_ITEM (); \
1154 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
1156 low_reg = (unsigned) POP_FAILURE_ITEM (); \
1157 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
1159 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
1161 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
1163 reg_info[this_reg].word = POP_FAILURE_ITEM (); \
1164 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
1166 regend[this_reg] = (const char *) POP_FAILURE_ITEM (); \
1167 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
1169 regstart[this_reg] = (const char *) POP_FAILURE_ITEM (); \
1170 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
1173 DEBUG_STATEMENT (nfailure_points_popped++); \
1174 } /* POP_FAILURE_POINT */
1178 /* Structure for per-register (a.k.a. per-group) information.
1179 This must not be longer than one word, because we push this value
1180 onto the failure stack. Other register information, such as the
1181 starting and ending positions (which are addresses), and the list of
1182 inner groups (which is a bits list) are maintained in separate
1185 We are making a (strictly speaking) nonportable assumption here: that
1186 the compiler will pack our bit fields into something that fits into
1187 the type of `word', i.e., is something that fits into one item on the
1191 fail_stack_elt_t word;
1194 /* This field is one if this group can match the empty string,
1195 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
1196 #define MATCH_NULL_UNSET_VALUE 3
1197 unsigned match_null_string_p : 2;
1198 unsigned is_active : 1;
1199 unsigned matched_something : 1;
1200 unsigned ever_matched_something : 1;
1202 } register_info_type;
1204 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
1205 #define IS_ACTIVE(R) ((R).bits.is_active)
1206 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
1207 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
1210 /* Call this when have matched a real character; it sets `matched' flags
1211 for the subexpressions which we are currently inside. Also records
1212 that those subexprs have matched. */
1213 #define SET_REGS_MATCHED() \
1217 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
1219 MATCHED_SOMETHING (reg_info[r]) \
1220 = EVER_MATCHED_SOMETHING (reg_info[r]) \
1227 /* Registers are set to a sentinel when they haven't yet matched. */
1228 #define REG_UNSET_VALUE ((char *) -1)
1229 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
1233 /* How do we implement a missing MATCH_MAY_ALLOCATE?
1234 We make the fail stack a global thing, and then grow it to
1235 re_max_failures when we compile. */
1236 #ifndef MATCH_MAY_ALLOCATE
1237 static fail_stack_type fail_stack;
1239 static const char ** regstart, ** regend;
1240 static const char ** old_regstart, ** old_regend;
1241 static const char **best_regstart, **best_regend;
1242 static register_info_type *reg_info;
1243 static const char **reg_dummy;
1244 static register_info_type *reg_info_dummy;
1248 /* Subroutine declarations and macros for regex_compile. */
1250 static void store_op1 (), store_op2 ();
1251 static void insert_op1 (), insert_op2 ();
1252 static boolean at_begline_loc_p (), at_endline_loc_p ();
1253 static boolean group_in_compile_stack ();
1254 static reg_errcode_t compile_range ();
1256 /* Fetch the next character in the uncompiled pattern---translating it
1257 if necessary. Also cast from a signed character in the constant
1258 string passed to us by the user to an unsigned char that we can use
1259 as an array index (in, e.g., `translate'). */
1260 #define PATFETCH(c) \
1261 do {if (p == pend) return REG_EEND; \
1262 c = (unsigned char) *p++; \
1263 if (translate) c = translate[c]; \
1266 /* Fetch the next character in the uncompiled pattern, with no
1268 #define PATFETCH_RAW(c) \
1269 do {if (p == pend) return REG_EEND; \
1270 c = (unsigned char) *p++; \
1273 /* Go backwards one character in the pattern. */
1274 #define PATUNFETCH p--
1277 /* If `translate' is non-null, return translate[D], else just D. We
1278 cast the subscript to translate because some data is declared as
1279 `char *', to avoid warnings when a string constant is passed. But
1280 when we use a character as a subscript we must make it unsigned. */
1281 #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
1284 /* Macros for outputting the compiled pattern into `buffer'. */
1286 /* If the buffer isn't allocated when it comes in, use this. */
1287 #define INIT_BUF_SIZE 32
1289 /* Make sure we have at least N more bytes of space in buffer. */
1290 #define GET_BUFFER_SPACE(n) \
1291 while (b - bufp->buffer + (n) > bufp->allocated) \
1294 /* Make sure we have one more byte of buffer space and then add C to it. */
1295 #define BUF_PUSH(c) \
1297 GET_BUFFER_SPACE (1); \
1298 *b++ = (unsigned char) (c); \
1302 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
1303 #define BUF_PUSH_2(c1, c2) \
1305 GET_BUFFER_SPACE (2); \
1306 *b++ = (unsigned char) (c1); \
1307 *b++ = (unsigned char) (c2); \
1311 /* As with BUF_PUSH_2, except for three bytes. */
1312 #define BUF_PUSH_3(c1, c2, c3) \
1314 GET_BUFFER_SPACE (3); \
1315 *b++ = (unsigned char) (c1); \
1316 *b++ = (unsigned char) (c2); \
1317 *b++ = (unsigned char) (c3); \
1321 /* Store a jump with opcode OP at LOC to location TO. We store a
1322 relative address offset by the three bytes the jump itself occupies. */
1323 #define STORE_JUMP(op, loc, to) \
1324 store_op1 (op, loc, (to) - (loc) - 3)
1326 /* Likewise, for a two-argument jump. */
1327 #define STORE_JUMP2(op, loc, to, arg) \
1328 store_op2 (op, loc, (to) - (loc) - 3, arg)
1330 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
1331 #define INSERT_JUMP(op, loc, to) \
1332 insert_op1 (op, loc, (to) - (loc) - 3, b)
1334 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
1335 #define INSERT_JUMP2(op, loc, to, arg) \
1336 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
1339 /* This is not an arbitrary limit: the arguments which represent offsets
1340 into the pattern are two bytes long. So if 2^16 bytes turns out to
1341 be too small, many things would have to change. */
1342 #define MAX_BUF_SIZE (1L << 16)
1345 /* Extend the buffer by twice its current size via realloc and
1346 reset the pointers that pointed into the old block to point to the
1347 correct places in the new one. If extending the buffer results in it
1348 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
1349 #define EXTEND_BUFFER() \
1351 unsigned char *old_buffer = bufp->buffer; \
1352 if (bufp->allocated == MAX_BUF_SIZE) \
1354 bufp->allocated <<= 1; \
1355 if (bufp->allocated > MAX_BUF_SIZE) \
1356 bufp->allocated = MAX_BUF_SIZE; \
1357 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
1358 if (bufp->buffer == NULL) \
1359 return REG_ESPACE; \
1360 /* If the buffer moved, move all the pointers into it. */ \
1361 if (old_buffer != bufp->buffer) \
1363 b = (b - old_buffer) + bufp->buffer; \
1364 begalt = (begalt - old_buffer) + bufp->buffer; \
1365 if (fixup_alt_jump) \
1366 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
1368 laststart = (laststart - old_buffer) + bufp->buffer; \
1369 if (pending_exact) \
1370 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
1375 /* Since we have one byte reserved for the register number argument to
1376 {start,stop}_memory, the maximum number of groups we can report
1377 things about is what fits in that byte. */
1378 #define MAX_REGNUM 255
1380 /* But patterns can have more than `MAX_REGNUM' registers. We just
1381 ignore the excess. */
1382 typedef unsigned regnum_t;
1385 /* Macros for the compile stack. */
1387 /* Since offsets can go either forwards or backwards, this type needs to
1388 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
1389 typedef int pattern_offset_t;
1393 pattern_offset_t begalt_offset;
1394 pattern_offset_t fixup_alt_jump;
1395 pattern_offset_t inner_group_offset;
1396 pattern_offset_t laststart_offset;
1398 } compile_stack_elt_t;
1403 compile_stack_elt_t *stack;
1405 unsigned avail; /* Offset of next open position. */
1406 } compile_stack_type;
1409 #define INIT_COMPILE_STACK_SIZE 32
1411 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1412 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1414 /* The next available element. */
1415 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1418 /* Set the bit for character C in a list. */
1419 #define SET_LIST_BIT(c) \
1420 (b[((unsigned char) (c)) / BYTEWIDTH] \
1421 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1424 /* Get the next unsigned number in the uncompiled pattern. */
1425 #define GET_UNSIGNED_NUMBER(num) \
1429 while (ISDIGIT (c)) \
1433 num = num * 10 + c - '0'; \
1441 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1443 #define IS_CHAR_CLASS(string) \
1444 (STREQ (string, "alpha") || STREQ (string, "upper") \
1445 || STREQ (string, "lower") || STREQ (string, "digit") \
1446 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1447 || STREQ (string, "space") || STREQ (string, "print") \
1448 || STREQ (string, "punct") || STREQ (string, "graph") \
1449 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1451 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1452 Returns one of error codes defined in `regex.h', or zero for success.
1454 Assumes the `allocated' (and perhaps `buffer') and `translate'
1455 fields are set in BUFP on entry.
1457 If it succeeds, results are put in BUFP (if it returns an error, the
1458 contents of BUFP are undefined):
1459 `buffer' is the compiled pattern;
1460 `syntax' is set to SYNTAX;
1461 `used' is set to the length of the compiled pattern;
1462 `fastmap_accurate' is zero;
1463 `re_nsub' is the number of subexpressions in PATTERN;
1464 `not_bol' and `not_eol' are zero;
1466 The `fastmap' and `newline_anchor' fields are neither
1467 examined nor set. */
1469 static reg_errcode_t
1470 regex_compile (pattern, size, syntax, bufp)
1471 const char *pattern;
1473 reg_syntax_t syntax;
1474 struct re_pattern_buffer *bufp;
1476 /* We fetch characters from PATTERN here. Even though PATTERN is
1477 `char *' (i.e., signed), we declare these variables as unsigned, so
1478 they can be reliably used as array indices. */
1479 register unsigned char c, c1;
1481 /* A random tempory spot in PATTERN. */
1484 /* Points to the end of the buffer, where we should append. */
1485 register unsigned char *b;
1487 /* Keeps track of unclosed groups. */
1488 compile_stack_type compile_stack;
1490 /* Points to the current (ending) position in the pattern. */
1491 const char *p = pattern;
1492 const char *pend = pattern + size;
1494 /* How to translate the characters in the pattern. */
1495 char *translate = bufp->translate;
1497 /* Address of the count-byte of the most recently inserted `exactn'
1498 command. This makes it possible to tell if a new exact-match
1499 character can be added to that command or if the character requires
1500 a new `exactn' command. */
1501 unsigned char *pending_exact = 0;
1503 /* Address of start of the most recently finished expression.
1504 This tells, e.g., postfix * where to find the start of its
1505 operand. Reset at the beginning of groups and alternatives. */
1506 unsigned char *laststart = 0;
1508 /* Address of beginning of regexp, or inside of last group. */
1509 unsigned char *begalt;
1511 /* Place in the uncompiled pattern (i.e., the {) to
1512 which to go back if the interval is invalid. */
1513 const char *beg_interval;
1515 /* Address of the place where a forward jump should go to the end of
1516 the containing expression. Each alternative of an `or' -- except the
1517 last -- ends with a forward jump of this sort. */
1518 unsigned char *fixup_alt_jump = 0;
1520 /* Counts open-groups as they are encountered. Remembered for the
1521 matching close-group on the compile stack, so the same register
1522 number is put in the stop_memory as the start_memory. */
1523 regnum_t regnum = 0;
1526 DEBUG_PRINT1 ("\nCompiling pattern: ");
1529 unsigned debug_count;
1531 for (debug_count = 0; debug_count < size; debug_count++)
1532 printchar (pattern[debug_count]);
1537 /* Initialize the compile stack. */
1538 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1539 if (compile_stack.stack == NULL)
1542 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1543 compile_stack.avail = 0;
1545 /* Initialize the pattern buffer. */
1546 bufp->syntax = syntax;
1547 bufp->fastmap_accurate = 0;
1548 bufp->not_bol = bufp->not_eol = 0;
1550 /* Set `used' to zero, so that if we return an error, the pattern
1551 printer (for debugging) will think there's no pattern. We reset it
1555 /* Always count groups, whether or not bufp->no_sub is set. */
1558 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1559 /* Initialize the syntax table. */
1560 init_syntax_once ();
1563 if (bufp->allocated == 0)
1566 { /* If zero allocated, but buffer is non-null, try to realloc
1567 enough space. This loses if buffer's address is bogus, but
1568 that is the user's responsibility. */
1569 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1572 { /* Caller did not allocate a buffer. Do it for them. */
1573 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1575 if (!bufp->buffer) return REG_ESPACE;
1577 bufp->allocated = INIT_BUF_SIZE;
1580 begalt = b = bufp->buffer;
1582 /* Loop through the uncompiled pattern until we're at the end. */
1591 if ( /* If at start of pattern, it's an operator. */
1593 /* If context independent, it's an operator. */
1594 || syntax & RE_CONTEXT_INDEP_ANCHORS
1595 /* Otherwise, depends on what's come before. */
1596 || at_begline_loc_p (pattern, p, syntax))
1606 if ( /* If at end of pattern, it's an operator. */
1608 /* If context independent, it's an operator. */
1609 || syntax & RE_CONTEXT_INDEP_ANCHORS
1610 /* Otherwise, depends on what's next. */
1611 || at_endline_loc_p (p, pend, syntax))
1621 if ((syntax & RE_BK_PLUS_QM)
1622 || (syntax & RE_LIMITED_OPS))
1626 /* If there is no previous pattern... */
1629 if (syntax & RE_CONTEXT_INVALID_OPS)
1631 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1636 /* Are we optimizing this jump? */
1637 boolean keep_string_p = false;
1639 /* 1 means zero (many) matches is allowed. */
1640 char zero_times_ok = 0, many_times_ok = 0;
1642 /* If there is a sequence of repetition chars, collapse it
1643 down to just one (the right one). We can't combine
1644 interval operators with these because of, e.g., `a{2}*',
1645 which should only match an even number of `a's. */
1649 zero_times_ok |= c != '+';
1650 many_times_ok |= c != '?';
1658 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1661 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1663 if (p == pend) return REG_EESCAPE;
1666 if (!(c1 == '+' || c1 == '?'))
1681 /* If we get here, we found another repeat character. */
1684 /* Star, etc. applied to an empty pattern is equivalent
1685 to an empty pattern. */
1689 /* Now we know whether or not zero matches is allowed
1690 and also whether or not two or more matches is allowed. */
1692 { /* More than one repetition is allowed, so put in at the
1693 end a backward relative jump from `b' to before the next
1694 jump we're going to put in below (which jumps from
1695 laststart to after this jump).
1697 But if we are at the `*' in the exact sequence `.*\n',
1698 insert an unconditional jump backwards to the .,
1699 instead of the beginning of the loop. This way we only
1700 push a failure point once, instead of every time
1701 through the loop. */
1702 assert (p - 1 > pattern);
1704 /* Allocate the space for the jump. */
1705 GET_BUFFER_SPACE (3);
1707 /* We know we are not at the first character of the pattern,
1708 because laststart was nonzero. And we've already
1709 incremented `p', by the way, to be the character after
1710 the `*'. Do we have to do something analogous here
1711 for null bytes, because of RE_DOT_NOT_NULL? */
1712 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1714 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1715 && !(syntax & RE_DOT_NEWLINE))
1716 { /* We have .*\n. */
1717 STORE_JUMP (jump, b, laststart);
1718 keep_string_p = true;
1721 /* Anything else. */
1722 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1724 /* We've added more stuff to the buffer. */
1728 /* On failure, jump from laststart to b + 3, which will be the
1729 end of the buffer after this jump is inserted. */
1730 GET_BUFFER_SPACE (3);
1731 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1739 /* At least one repetition is required, so insert a
1740 `dummy_failure_jump' before the initial
1741 `on_failure_jump' instruction of the loop. This
1742 effects a skip over that instruction the first time
1743 we hit that loop. */
1744 GET_BUFFER_SPACE (3);
1745 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1760 boolean had_char_class = false;
1762 if (p == pend) return REG_EBRACK;
1764 /* Ensure that we have enough space to push a charset: the
1765 opcode, the length count, and the bitset; 34 bytes in all. */
1766 GET_BUFFER_SPACE (34);
1770 /* We test `*p == '^' twice, instead of using an if
1771 statement, so we only need one BUF_PUSH. */
1772 BUF_PUSH (*p == '^' ? charset_not : charset);
1776 /* Remember the first position in the bracket expression. */
1779 /* Push the number of bytes in the bitmap. */
1780 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1782 /* Clear the whole map. */
1783 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1785 /* charset_not matches newline according to a syntax bit. */
1786 if ((re_opcode_t) b[-2] == charset_not
1787 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1788 SET_LIST_BIT ('\n');
1790 /* Read in characters and ranges, setting map bits. */
1793 if (p == pend) return REG_EBRACK;
1797 /* \ might escape characters inside [...] and [^...]. */
1798 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1800 if (p == pend) return REG_EESCAPE;
1807 /* Could be the end of the bracket expression. If it's
1808 not (i.e., when the bracket expression is `[]' so
1809 far), the ']' character bit gets set way below. */
1810 if (c == ']' && p != p1 + 1)
1813 /* Look ahead to see if it's a range when the last thing
1814 was a character class. */
1815 if (had_char_class && c == '-' && *p != ']')
1818 /* Look ahead to see if it's a range when the last thing
1819 was a character: if this is a hyphen not at the
1820 beginning or the end of a list, then it's the range
1823 && !(p - 2 >= pattern && p[-2] == '[')
1824 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1828 = compile_range (&p, pend, translate, syntax, b);
1829 if (ret != REG_NOERROR) return ret;
1832 else if (p[0] == '-' && p[1] != ']')
1833 { /* This handles ranges made up of characters only. */
1836 /* Move past the `-'. */
1839 ret = compile_range (&p, pend, translate, syntax, b);
1840 if (ret != REG_NOERROR) return ret;
1843 /* See if we're at the beginning of a possible character
1846 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1847 { /* Leave room for the null. */
1848 char str[CHAR_CLASS_MAX_LENGTH + 1];
1853 /* If pattern is `[[:'. */
1854 if (p == pend) return REG_EBRACK;
1859 if (c == ':' || c == ']' || p == pend
1860 || c1 == CHAR_CLASS_MAX_LENGTH)
1866 /* If isn't a word bracketed by `[:' and:`]':
1867 undo the ending character, the letters, and leave
1868 the leading `:' and `[' (but set bits for them). */
1869 if (c == ':' && *p == ']')
1872 boolean is_alnum = STREQ (str, "alnum");
1873 boolean is_alpha = STREQ (str, "alpha");
1874 boolean is_blank = STREQ (str, "blank");
1875 boolean is_cntrl = STREQ (str, "cntrl");
1876 boolean is_digit = STREQ (str, "digit");
1877 boolean is_graph = STREQ (str, "graph");
1878 boolean is_lower = STREQ (str, "lower");
1879 boolean is_print = STREQ (str, "print");
1880 boolean is_punct = STREQ (str, "punct");
1881 boolean is_space = STREQ (str, "space");
1882 boolean is_upper = STREQ (str, "upper");
1883 boolean is_xdigit = STREQ (str, "xdigit");
1885 if (!IS_CHAR_CLASS (str)) return REG_ECTYPE;
1887 /* Throw away the ] at the end of the character
1891 if (p == pend) return REG_EBRACK;
1893 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
1895 if ( (is_alnum && ISALNUM (ch))
1896 || (is_alpha && ISALPHA (ch))
1897 || (is_blank && ISBLANK (ch))
1898 || (is_cntrl && ISCNTRL (ch))
1899 || (is_digit && ISDIGIT (ch))
1900 || (is_graph && ISGRAPH (ch))
1901 || (is_lower && ISLOWER (ch))
1902 || (is_print && ISPRINT (ch))
1903 || (is_punct && ISPUNCT (ch))
1904 || (is_space && ISSPACE (ch))
1905 || (is_upper && ISUPPER (ch))
1906 || (is_xdigit && ISXDIGIT (ch)))
1909 had_char_class = true;
1918 had_char_class = false;
1923 had_char_class = false;
1928 /* Discard any (non)matching list bytes that are all 0 at the
1929 end of the map. Decrease the map-length byte too. */
1930 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
1938 if (syntax & RE_NO_BK_PARENS)
1945 if (syntax & RE_NO_BK_PARENS)
1952 if (syntax & RE_NEWLINE_ALT)
1959 if (syntax & RE_NO_BK_VBAR)
1966 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
1967 goto handle_interval;
1973 if (p == pend) return REG_EESCAPE;
1975 /* Do not translate the character after the \, so that we can
1976 distinguish, e.g., \B from \b, even if we normally would
1977 translate, e.g., B to b. */
1983 if (syntax & RE_NO_BK_PARENS)
1984 goto normal_backslash;
1990 if (COMPILE_STACK_FULL)
1992 RETALLOC (compile_stack.stack, compile_stack.size << 1,
1993 compile_stack_elt_t);
1994 if (compile_stack.stack == NULL) return REG_ESPACE;
1996 compile_stack.size <<= 1;
1999 /* These are the values to restore when we hit end of this
2000 group. They are all relative offsets, so that if the
2001 whole pattern moves because of realloc, they will still
2003 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
2004 COMPILE_STACK_TOP.fixup_alt_jump
2005 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
2006 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
2007 COMPILE_STACK_TOP.regnum = regnum;
2009 /* We will eventually replace the 0 with the number of
2010 groups inner to this one. But do not push a
2011 start_memory for groups beyond the last one we can
2012 represent in the compiled pattern. */
2013 if (regnum <= MAX_REGNUM)
2015 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
2016 BUF_PUSH_3 (start_memory, regnum, 0);
2019 compile_stack.avail++;
2024 /* If we've reached MAX_REGNUM groups, then this open
2025 won't actually generate any code, so we'll have to
2026 clear pending_exact explicitly. */
2032 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
2034 if (COMPILE_STACK_EMPTY)
2035 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2036 goto normal_backslash;
2042 { /* Push a dummy failure point at the end of the
2043 alternative for a possible future
2044 `pop_failure_jump' to pop. See comments at
2045 `push_dummy_failure' in `re_match_2'. */
2046 BUF_PUSH (push_dummy_failure);
2048 /* We allocated space for this jump when we assigned
2049 to `fixup_alt_jump', in the `handle_alt' case below. */
2050 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
2053 /* See similar code for backslashed left paren above. */
2054 if (COMPILE_STACK_EMPTY)
2055 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
2060 /* Since we just checked for an empty stack above, this
2061 ``can't happen''. */
2062 assert (compile_stack.avail != 0);
2064 /* We don't just want to restore into `regnum', because
2065 later groups should continue to be numbered higher,
2066 as in `(ab)c(de)' -- the second group is #2. */
2067 regnum_t this_group_regnum;
2069 compile_stack.avail--;
2070 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
2072 = COMPILE_STACK_TOP.fixup_alt_jump
2073 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
2075 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
2076 this_group_regnum = COMPILE_STACK_TOP.regnum;
2077 /* If we've reached MAX_REGNUM groups, then this open
2078 won't actually generate any code, so we'll have to
2079 clear pending_exact explicitly. */
2082 /* We're at the end of the group, so now we know how many
2083 groups were inside this one. */
2084 if (this_group_regnum <= MAX_REGNUM)
2086 unsigned char *inner_group_loc
2087 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
2089 *inner_group_loc = regnum - this_group_regnum;
2090 BUF_PUSH_3 (stop_memory, this_group_regnum,
2091 regnum - this_group_regnum);
2097 case '|': /* `\|'. */
2098 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
2099 goto normal_backslash;
2101 if (syntax & RE_LIMITED_OPS)
2104 /* Insert before the previous alternative a jump which
2105 jumps to this alternative if the former fails. */
2106 GET_BUFFER_SPACE (3);
2107 INSERT_JUMP (on_failure_jump, begalt, b + 6);
2111 /* The alternative before this one has a jump after it
2112 which gets executed if it gets matched. Adjust that
2113 jump so it will jump to this alternative's analogous
2114 jump (put in below, which in turn will jump to the next
2115 (if any) alternative's such jump, etc.). The last such
2116 jump jumps to the correct final destination. A picture:
2122 If we are at `b', then fixup_alt_jump right now points to a
2123 three-byte space after `a'. We'll put in the jump, set
2124 fixup_alt_jump to right after `b', and leave behind three
2125 bytes which we'll fill in when we get to after `c'. */
2128 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2130 /* Mark and leave space for a jump after this alternative,
2131 to be filled in later either by next alternative or
2132 when know we're at the end of a series of alternatives. */
2134 GET_BUFFER_SPACE (3);
2143 /* If \{ is a literal. */
2144 if (!(syntax & RE_INTERVALS)
2145 /* If we're at `\{' and it's not the open-interval
2147 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
2148 || (p - 2 == pattern && p == pend))
2149 goto normal_backslash;
2153 /* If got here, then the syntax allows intervals. */
2155 /* At least (most) this many matches must be made. */
2156 int lower_bound = -1, upper_bound = -1;
2158 beg_interval = p - 1;
2162 if (syntax & RE_NO_BK_BRACES)
2163 goto unfetch_interval;
2168 GET_UNSIGNED_NUMBER (lower_bound);
2172 GET_UNSIGNED_NUMBER (upper_bound);
2173 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
2176 /* Interval such as `{1}' => match exactly once. */
2177 upper_bound = lower_bound;
2179 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
2180 || lower_bound > upper_bound)
2182 if (syntax & RE_NO_BK_BRACES)
2183 goto unfetch_interval;
2188 if (!(syntax & RE_NO_BK_BRACES))
2190 if (c != '\\') return REG_EBRACE;
2197 if (syntax & RE_NO_BK_BRACES)
2198 goto unfetch_interval;
2203 /* We just parsed a valid interval. */
2205 /* If it's invalid to have no preceding re. */
2208 if (syntax & RE_CONTEXT_INVALID_OPS)
2210 else if (syntax & RE_CONTEXT_INDEP_OPS)
2213 goto unfetch_interval;
2216 /* If the upper bound is zero, don't want to succeed at
2217 all; jump from `laststart' to `b + 3', which will be
2218 the end of the buffer after we insert the jump. */
2219 if (upper_bound == 0)
2221 GET_BUFFER_SPACE (3);
2222 INSERT_JUMP (jump, laststart, b + 3);
2226 /* Otherwise, we have a nontrivial interval. When
2227 we're all done, the pattern will look like:
2228 set_number_at <jump count> <upper bound>
2229 set_number_at <succeed_n count> <lower bound>
2230 succeed_n <after jump addr> <succed_n count>
2232 jump_n <succeed_n addr> <jump count>
2233 (The upper bound and `jump_n' are omitted if
2234 `upper_bound' is 1, though.) */
2236 { /* If the upper bound is > 1, we need to insert
2237 more at the end of the loop. */
2238 unsigned nbytes = 10 + (upper_bound > 1) * 10;
2240 GET_BUFFER_SPACE (nbytes);
2242 /* Initialize lower bound of the `succeed_n', even
2243 though it will be set during matching by its
2244 attendant `set_number_at' (inserted next),
2245 because `re_compile_fastmap' needs to know.
2246 Jump to the `jump_n' we might insert below. */
2247 INSERT_JUMP2 (succeed_n, laststart,
2248 b + 5 + (upper_bound > 1) * 5,
2252 /* Code to initialize the lower bound. Insert
2253 before the `succeed_n'. The `5' is the last two
2254 bytes of this `set_number_at', plus 3 bytes of
2255 the following `succeed_n'. */
2256 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
2259 if (upper_bound > 1)
2260 { /* More than one repetition is allowed, so
2261 append a backward jump to the `succeed_n'
2262 that starts this interval.
2264 When we've reached this during matching,
2265 we'll have matched the interval once, so
2266 jump back only `upper_bound - 1' times. */
2267 STORE_JUMP2 (jump_n, b, laststart + 5,
2271 /* The location we want to set is the second
2272 parameter of the `jump_n'; that is `b-2' as
2273 an absolute address. `laststart' will be
2274 the `set_number_at' we're about to insert;
2275 `laststart+3' the number to set, the source
2276 for the relative address. But we are
2277 inserting into the middle of the pattern --
2278 so everything is getting moved up by 5.
2279 Conclusion: (b - 2) - (laststart + 3) + 5,
2280 i.e., b - laststart.
2282 We insert this at the beginning of the loop
2283 so that if we fail during matching, we'll
2284 reinitialize the bounds. */
2285 insert_op2 (set_number_at, laststart, b - laststart,
2286 upper_bound - 1, b);
2291 beg_interval = NULL;
2296 /* If an invalid interval, match the characters as literals. */
2297 assert (beg_interval);
2299 beg_interval = NULL;
2301 /* normal_char and normal_backslash need `c'. */
2304 if (!(syntax & RE_NO_BK_BRACES))
2306 if (p > pattern && p[-1] == '\\')
2307 goto normal_backslash;
2312 /* There is no way to specify the before_dot and after_dot
2313 operators. rms says this is ok. --karl */
2321 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
2327 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
2334 BUF_PUSH (wordchar);
2340 BUF_PUSH (notwordchar);
2353 BUF_PUSH (wordbound);
2357 BUF_PUSH (notwordbound);
2368 case '1': case '2': case '3': case '4': case '5':
2369 case '6': case '7': case '8': case '9':
2370 if (syntax & RE_NO_BK_REFS)
2378 /* Can't back reference to a subexpression if inside of it. */
2379 if (group_in_compile_stack (compile_stack, c1))
2383 BUF_PUSH_2 (duplicate, c1);
2389 if (syntax & RE_BK_PLUS_QM)
2392 goto normal_backslash;
2396 /* You might think it would be useful for \ to mean
2397 not to translate; but if we don't translate it
2398 it will never match anything. */
2406 /* Expects the character in `c'. */
2408 /* If no exactn currently being built. */
2411 /* If last exactn not at current position. */
2412 || pending_exact + *pending_exact + 1 != b
2414 /* We have only one byte following the exactn for the count. */
2415 || *pending_exact == (1 << BYTEWIDTH) - 1
2417 /* If followed by a repetition operator. */
2418 || *p == '*' || *p == '^'
2419 || ((syntax & RE_BK_PLUS_QM)
2420 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2421 : (*p == '+' || *p == '?'))
2422 || ((syntax & RE_INTERVALS)
2423 && ((syntax & RE_NO_BK_BRACES)
2425 : (p[0] == '\\' && p[1] == '{'))))
2427 /* Start building a new exactn. */
2431 BUF_PUSH_2 (exactn, 0);
2432 pending_exact = b - 1;
2439 } /* while p != pend */
2442 /* Through the pattern now. */
2445 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2447 if (!COMPILE_STACK_EMPTY)
2450 free (compile_stack.stack);
2452 /* We have succeeded; set the length of the buffer. */
2453 bufp->used = b - bufp->buffer;
2458 DEBUG_PRINT1 ("\nCompiled pattern: \n");
2459 print_compiled_pattern (bufp);
2463 #ifndef MATCH_MAY_ALLOCATE
2464 /* Initialize the failure stack to the largest possible stack. This
2465 isn't necessary unless we're trying to avoid calling alloca in
2466 the search and match routines. */
2468 int num_regs = bufp->re_nsub + 1;
2470 /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
2471 is strictly greater than re_max_failures, the largest possible stack
2472 is 2 * re_max_failures failure points. */
2473 fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
2474 if (fail_stack.stack)
2476 (fail_stack_elt_t *) realloc (fail_stack.stack,
2478 * sizeof (fail_stack_elt_t)));
2481 (fail_stack_elt_t *) malloc (fail_stack.size
2482 * sizeof (fail_stack_elt_t));
2484 /* Initialize some other variables the matcher uses. */
2485 RETALLOC_IF (regstart, num_regs, const char *);
2486 RETALLOC_IF (regend, num_regs, const char *);
2487 RETALLOC_IF (old_regstart, num_regs, const char *);
2488 RETALLOC_IF (old_regend, num_regs, const char *);
2489 RETALLOC_IF (best_regstart, num_regs, const char *);
2490 RETALLOC_IF (best_regend, num_regs, const char *);
2491 RETALLOC_IF (reg_info, num_regs, register_info_type);
2492 RETALLOC_IF (reg_dummy, num_regs, const char *);
2493 RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
2498 } /* regex_compile */
2500 /* Subroutines for `regex_compile'. */
2502 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2505 store_op1 (op, loc, arg)
2510 *loc = (unsigned char) op;
2511 STORE_NUMBER (loc + 1, arg);
2515 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2518 store_op2 (op, loc, arg1, arg2)
2523 *loc = (unsigned char) op;
2524 STORE_NUMBER (loc + 1, arg1);
2525 STORE_NUMBER (loc + 3, arg2);
2529 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2530 for OP followed by two-byte integer parameter ARG. */
2533 insert_op1 (op, loc, arg, end)
2539 register unsigned char *pfrom = end;
2540 register unsigned char *pto = end + 3;
2542 while (pfrom != loc)
2545 store_op1 (op, loc, arg);
2549 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2552 insert_op2 (op, loc, arg1, arg2, end)
2558 register unsigned char *pfrom = end;
2559 register unsigned char *pto = end + 5;
2561 while (pfrom != loc)
2564 store_op2 (op, loc, arg1, arg2);
2568 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2569 after an alternative or a begin-subexpression. We assume there is at
2570 least one character before the ^. */
2573 at_begline_loc_p (pattern, p, syntax)
2574 const char *pattern, *p;
2575 reg_syntax_t syntax;
2577 const char *prev = p - 2;
2578 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2581 /* After a subexpression? */
2582 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2583 /* After an alternative? */
2584 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2588 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2589 at least one character after the $, i.e., `P < PEND'. */
2592 at_endline_loc_p (p, pend, syntax)
2593 const char *p, *pend;
2596 const char *next = p;
2597 boolean next_backslash = *next == '\\';
2598 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2601 /* Before a subexpression? */
2602 (syntax & RE_NO_BK_PARENS ? *next == ')'
2603 : next_backslash && next_next && *next_next == ')')
2604 /* Before an alternative? */
2605 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2606 : next_backslash && next_next && *next_next == '|');
2610 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2611 false if it's not. */
2614 group_in_compile_stack (compile_stack, regnum)
2615 compile_stack_type compile_stack;
2620 for (this_element = compile_stack.avail - 1;
2623 if (compile_stack.stack[this_element].regnum == regnum)
2630 /* Read the ending character of a range (in a bracket expression) from the
2631 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2632 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2633 Then we set the translation of all bits between the starting and
2634 ending characters (inclusive) in the compiled pattern B.
2636 Return an error code.
2638 We use these short variable names so we can use the same macros as
2639 `regex_compile' itself. */
2641 static reg_errcode_t
2642 compile_range (p_ptr, pend, translate, syntax, b)
2643 const char **p_ptr, *pend;
2645 reg_syntax_t syntax;
2650 const char *p = *p_ptr;
2651 int range_start, range_end;
2656 /* Even though the pattern is a signed `char *', we need to fetch
2657 with unsigned char *'s; if the high bit of the pattern character
2658 is set, the range endpoints will be negative if we fetch using a
2661 We also want to fetch the endpoints without translating them; the
2662 appropriate translation is done in the bit-setting loop below. */
2663 range_start = ((unsigned char *) p)[-2];
2664 range_end = ((unsigned char *) p)[0];
2666 /* Have to increment the pointer into the pattern string, so the
2667 caller isn't still at the ending character. */
2670 /* If the start is after the end, the range is empty. */
2671 if (range_start > range_end)
2672 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2674 /* Here we see why `this_char' has to be larger than an `unsigned
2675 char' -- the range is inclusive, so if `range_end' == 0xff
2676 (assuming 8-bit characters), we would otherwise go into an infinite
2677 loop, since all characters <= 0xff. */
2678 for (this_char = range_start; this_char <= range_end; this_char++)
2680 SET_LIST_BIT (TRANSLATE (this_char));
2686 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2687 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2688 characters can start a string that matches the pattern. This fastmap
2689 is used by re_search to skip quickly over impossible starting points.
2691 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2692 area as BUFP->fastmap.
2694 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2697 Returns 0 if we succeed, -2 if an internal error. */
2700 re_compile_fastmap (bufp)
2701 struct re_pattern_buffer *bufp;
2704 #ifdef MATCH_MAY_ALLOCATE
2705 fail_stack_type fail_stack;
2707 #ifndef REGEX_MALLOC
2710 /* We don't push any register information onto the failure stack. */
2711 unsigned num_regs = 0;
2713 register char *fastmap = bufp->fastmap;
2714 unsigned char *pattern = bufp->buffer;
2715 unsigned long size = bufp->used;
2716 const unsigned char *p = pattern;
2717 register unsigned char *pend = pattern + size;
2719 /* Assume that each path through the pattern can be null until
2720 proven otherwise. We set this false at the bottom of switch
2721 statement, to which we get only if a particular path doesn't
2722 match the empty string. */
2723 boolean path_can_be_null = true;
2725 /* We aren't doing a `succeed_n' to begin with. */
2726 boolean succeed_n_p = false;
2728 assert (fastmap != NULL && p != NULL);
2731 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2732 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2733 bufp->can_be_null = 0;
2735 while (p != pend || !FAIL_STACK_EMPTY ())
2739 bufp->can_be_null |= path_can_be_null;
2741 /* Reset for next path. */
2742 path_can_be_null = true;
2744 p = fail_stack.stack[--fail_stack.avail];
2747 /* We should never be about to go beyond the end of the pattern. */
2750 #ifdef SWITCH_ENUM_BUG
2751 switch ((int) ((re_opcode_t) *p++))
2753 switch ((re_opcode_t) *p++)
2757 /* I guess the idea here is to simply not bother with a fastmap
2758 if a backreference is used, since it's too hard to figure out
2759 the fastmap for the corresponding group. Setting
2760 `can_be_null' stops `re_search_2' from using the fastmap, so
2761 that is all we do. */
2763 bufp->can_be_null = 1;
2767 /* Following are the cases which match a character. These end
2776 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2777 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2783 /* Chars beyond end of map must be allowed. */
2784 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2787 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2788 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2794 for (j = 0; j < (1 << BYTEWIDTH); j++)
2795 if (SYNTAX (j) == Sword)
2801 for (j = 0; j < (1 << BYTEWIDTH); j++)
2802 if (SYNTAX (j) != Sword)
2808 /* `.' matches anything ... */
2809 for (j = 0; j < (1 << BYTEWIDTH); j++)
2812 /* ... except perhaps newline. */
2813 if (!(bufp->syntax & RE_DOT_NEWLINE))
2816 /* Return if we have already set `can_be_null'; if we have,
2817 then the fastmap is irrelevant. Something's wrong here. */
2818 else if (bufp->can_be_null)
2821 /* Otherwise, have to check alternative paths. */
2828 for (j = 0; j < (1 << BYTEWIDTH); j++)
2829 if (SYNTAX (j) == (enum syntaxcode) k)
2836 for (j = 0; j < (1 << BYTEWIDTH); j++)
2837 if (SYNTAX (j) != (enum syntaxcode) k)
2842 /* All cases after this match the empty string. These end with
2850 #endif /* not emacs */
2862 case push_dummy_failure:
2867 case pop_failure_jump:
2868 case maybe_pop_jump:
2871 case dummy_failure_jump:
2872 EXTRACT_NUMBER_AND_INCR (j, p);
2877 /* Jump backward implies we just went through the body of a
2878 loop and matched nothing. Opcode jumped to should be
2879 `on_failure_jump' or `succeed_n'. Just treat it like an
2880 ordinary jump. For a * loop, it has pushed its failure
2881 point already; if so, discard that as redundant. */
2882 if ((re_opcode_t) *p != on_failure_jump
2883 && (re_opcode_t) *p != succeed_n)
2887 EXTRACT_NUMBER_AND_INCR (j, p);
2890 /* If what's on the stack is where we are now, pop it. */
2891 if (!FAIL_STACK_EMPTY ()
2892 && fail_stack.stack[fail_stack.avail - 1] == p)
2898 case on_failure_jump:
2899 case on_failure_keep_string_jump:
2900 handle_on_failure_jump:
2901 EXTRACT_NUMBER_AND_INCR (j, p);
2903 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
2904 end of the pattern. We don't want to push such a point,
2905 since when we restore it above, entering the switch will
2906 increment `p' past the end of the pattern. We don't need
2907 to push such a point since we obviously won't find any more
2908 fastmap entries beyond `pend'. Such a pattern can match
2909 the null string, though. */
2912 if (!PUSH_PATTERN_OP (p + j, fail_stack))
2916 bufp->can_be_null = 1;
2920 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
2921 succeed_n_p = false;
2928 /* Get to the number of times to succeed. */
2931 /* Increment p past the n for when k != 0. */
2932 EXTRACT_NUMBER_AND_INCR (k, p);
2936 succeed_n_p = true; /* Spaghetti code alert. */
2937 goto handle_on_failure_jump;
2954 abort (); /* We have listed all the cases. */
2957 /* Getting here means we have found the possible starting
2958 characters for one path of the pattern -- and that the empty
2959 string does not match. We need not follow this path further.
2960 Instead, look at the next alternative (remembered on the
2961 stack), or quit if no more. The test at the top of the loop
2962 does these things. */
2963 path_can_be_null = false;
2967 /* Set `can_be_null' for the last path (also the first path, if the
2968 pattern is empty). */
2969 bufp->can_be_null |= path_can_be_null;
2971 } /* re_compile_fastmap */
2973 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
2974 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
2975 this memory for recording register information. STARTS and ENDS
2976 must be allocated using the malloc library routine, and must each
2977 be at least NUM_REGS * sizeof (regoff_t) bytes long.
2979 If NUM_REGS == 0, then subsequent matches should allocate their own
2982 Unless this function is called, the first search or match using
2983 PATTERN_BUFFER will allocate its own register data, without
2984 freeing the old data. */
2987 re_set_registers (bufp, regs, num_regs, starts, ends)
2988 struct re_pattern_buffer *bufp;
2989 struct re_registers *regs;
2991 regoff_t *starts, *ends;
2995 bufp->regs_allocated = REGS_REALLOCATE;
2996 regs->num_regs = num_regs;
2997 regs->start = starts;
3002 bufp->regs_allocated = REGS_UNALLOCATED;
3004 regs->start = regs->end = (regoff_t) 0;
3008 /* Searching routines. */
3010 /* Like re_search_2, below, but only one string is specified, and
3011 doesn't let you say where to stop matching. */
3014 re_search (bufp, string, size, startpos, range, regs)
3015 struct re_pattern_buffer *bufp;
3017 int size, startpos, range;
3018 struct re_registers *regs;
3020 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
3025 /* Using the compiled pattern in BUFP->buffer, first tries to match the
3026 virtual concatenation of STRING1 and STRING2, starting first at index
3027 STARTPOS, then at STARTPOS + 1, and so on.
3029 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
3031 RANGE is how far to scan while trying to match. RANGE = 0 means try
3032 only at STARTPOS; in general, the last start tried is STARTPOS +
3035 In REGS, return the indices of the virtual concatenation of STRING1
3036 and STRING2 that matched the entire BUFP->buffer and its contained
3039 Do not consider matching one past the index STOP in the virtual
3040 concatenation of STRING1 and STRING2.
3042 We return either the position in the strings at which the match was
3043 found, -1 if no match, or -2 if error (such as failure
3047 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
3048 struct re_pattern_buffer *bufp;
3049 const char *string1, *string2;
3053 struct re_registers *regs;
3057 register char *fastmap = bufp->fastmap;
3058 register char *translate = bufp->translate;
3059 int total_size = size1 + size2;
3060 int endpos = startpos + range;
3062 /* Check for out-of-range STARTPOS. */
3063 if (startpos < 0 || startpos > total_size)
3066 /* Fix up RANGE if it might eventually take us outside
3067 the virtual concatenation of STRING1 and STRING2. */
3069 range = -1 - startpos;
3070 else if (endpos > total_size)
3071 range = total_size - startpos;
3073 /* If the search isn't to be a backwards one, don't waste time in a
3074 search for a pattern that must be anchored. */
3075 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
3083 /* Update the fastmap now if not correct already. */
3084 if (fastmap && !bufp->fastmap_accurate)
3085 if (re_compile_fastmap (bufp) == -2)
3088 /* Loop through the string, looking for a place to start matching. */
3091 /* If a fastmap is supplied, skip quickly over characters that
3092 cannot be the start of a match. If the pattern can match the
3093 null string, however, we don't need to skip characters; we want
3094 the first null string. */
3095 if (fastmap && startpos < total_size && !bufp->can_be_null)
3097 if (range > 0) /* Searching forwards. */
3099 register const char *d;
3100 register int lim = 0;
3103 if (startpos < size1 && startpos + range >= size1)
3104 lim = range - (size1 - startpos);
3106 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
3108 /* Written out as an if-else to avoid testing `translate'
3112 && !fastmap[(unsigned char)
3113 translate[(unsigned char) *d++]])
3116 while (range > lim && !fastmap[(unsigned char) *d++])
3119 startpos += irange - range;
3121 else /* Searching backwards. */
3123 register char c = (size1 == 0 || startpos >= size1
3124 ? string2[startpos - size1]
3125 : string1[startpos]);
3127 if (!fastmap[(unsigned char) TRANSLATE (c)])
3132 /* If can't match the null string, and that's all we have left, fail. */
3133 if (range >= 0 && startpos == total_size && fastmap
3134 && !bufp->can_be_null)
3137 val = re_match_2 (bufp, string1, size1, string2, size2,
3138 startpos, regs, stop);
3162 /* Declarations and macros for re_match_2. */
3164 static int bcmp_translate ();
3165 static boolean alt_match_null_string_p (),
3166 common_op_match_null_string_p (),
3167 group_match_null_string_p ();
3169 /* This converts PTR, a pointer into one of the search strings `string1'
3170 and `string2' into an offset from the beginning of that string. */
3171 #define POINTER_TO_OFFSET(ptr) \
3172 (FIRST_STRING_P (ptr) ? (ptr) - string1 : (ptr) - string2 + size1)
3174 /* Macros for dealing with the split strings in re_match_2. */
3176 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3178 /* Call before fetching a character with *d. This switches over to
3179 string2 if necessary. */
3180 #define PREFETCH() \
3183 /* End of string2 => fail. */ \
3184 if (dend == end_match_2) \
3186 /* End of string1 => advance to string2. */ \
3188 dend = end_match_2; \
3192 /* Test if at very beginning or at very end of the virtual concatenation
3193 of `string1' and `string2'. If only one string, it's `string2'. */
3194 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3195 #define AT_STRINGS_END(d) ((d) == end2)
3198 /* Test if D points to a character which is word-constituent. We have
3199 two special cases to check for: if past the end of string1, look at
3200 the first character in string2; and if before the beginning of
3201 string2, look at the last character in string1. */
3202 #define WORDCHAR_P(d) \
3203 (SYNTAX ((d) == end1 ? *string2 \
3204 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3207 /* Test if the character before D and the one at D differ with respect
3208 to being word-constituent. */
3209 #define AT_WORD_BOUNDARY(d) \
3210 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3211 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3214 /* Free everything we malloc. */
3215 #ifdef MATCH_MAY_ALLOCATE
3217 #define FREE_VAR(var) if (var) free (var); var = NULL
3218 #define FREE_VARIABLES() \
3220 FREE_VAR (fail_stack.stack); \
3221 FREE_VAR (regstart); \
3222 FREE_VAR (regend); \
3223 FREE_VAR (old_regstart); \
3224 FREE_VAR (old_regend); \
3225 FREE_VAR (best_regstart); \
3226 FREE_VAR (best_regend); \
3227 FREE_VAR (reg_info); \
3228 FREE_VAR (reg_dummy); \
3229 FREE_VAR (reg_info_dummy); \
3231 #else /* not REGEX_MALLOC */
3232 /* Some MIPS systems (at least) want this to free alloca'd storage. */
3233 #define FREE_VARIABLES() alloca (0)
3234 #endif /* not REGEX_MALLOC */
3236 #define FREE_VARIABLES() /* Do nothing! */
3237 #endif /* not MATCH_MAY_ALLOCATE */
3239 /* These values must meet several constraints. They must not be valid
3240 register values; since we have a limit of 255 registers (because
3241 we use only one byte in the pattern for the register number), we can
3242 use numbers larger than 255. They must differ by 1, because of
3243 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3244 be larger than the value for the highest register, so we do not try
3245 to actually save any registers when none are active. */
3246 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3247 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3249 /* Matching routines. */
3251 #ifndef emacs /* Emacs never uses this. */
3252 /* re_match is like re_match_2 except it takes only a single string. */
3255 re_match (bufp, string, size, pos, regs)
3256 struct re_pattern_buffer *bufp;
3259 struct re_registers *regs;
3261 return re_match_2 (bufp, NULL, 0, string, size, pos, regs, size);
3263 #endif /* not emacs */
3266 /* re_match_2 matches the compiled pattern in BUFP against the
3267 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3268 and SIZE2, respectively). We start matching at POS, and stop
3271 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3272 store offsets for the substring each group matched in REGS. See the
3273 documentation for exactly how many groups we fill.
3275 We return -1 if no match, -2 if an internal error (such as the
3276 failure stack overflowing). Otherwise, we return the length of the
3277 matched substring. */
3280 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3281 struct re_pattern_buffer *bufp;
3282 const char *string1, *string2;
3285 struct re_registers *regs;
3288 /* General temporaries. */
3292 /* Just past the end of the corresponding string. */
3293 const char *end1, *end2;
3295 /* Pointers into string1 and string2, just past the last characters in
3296 each to consider matching. */
3297 const char *end_match_1, *end_match_2;
3299 /* Where we are in the data, and the end of the current string. */
3300 const char *d, *dend;
3302 /* Where we are in the pattern, and the end of the pattern. */
3303 unsigned char *p = bufp->buffer;
3304 register unsigned char *pend = p + bufp->used;
3306 /* We use this to map every character in the string. */
3307 char *translate = bufp->translate;
3309 /* Failure point stack. Each place that can handle a failure further
3310 down the line pushes a failure point on this stack. It consists of
3311 restart, regend, and reg_info for all registers corresponding to
3312 the subexpressions we're currently inside, plus the number of such
3313 registers, and, finally, two char *'s. The first char * is where
3314 to resume scanning the pattern; the second one is where to resume
3315 scanning the strings. If the latter is zero, the failure point is
3316 a ``dummy''; if a failure happens and the failure point is a dummy,
3317 it gets discarded and the next next one is tried. */
3318 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3319 fail_stack_type fail_stack;
3322 static unsigned failure_id = 0;
3323 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3326 /* We fill all the registers internally, independent of what we
3327 return, for use in backreferences. The number here includes
3328 an element for register zero. */
3329 unsigned num_regs = bufp->re_nsub + 1;
3331 /* The currently active registers. */
3332 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3333 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3335 /* Information on the contents of registers. These are pointers into
3336 the input strings; they record just what was matched (on this
3337 attempt) by a subexpression part of the pattern, that is, the
3338 regnum-th regstart pointer points to where in the pattern we began
3339 matching and the regnum-th regend points to right after where we
3340 stopped matching the regnum-th subexpression. (The zeroth register
3341 keeps track of what the whole pattern matches.) */
3342 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3343 const char **regstart, **regend;
3346 /* If a group that's operated upon by a repetition operator fails to
3347 match anything, then the register for its start will need to be
3348 restored because it will have been set to wherever in the string we
3349 are when we last see its open-group operator. Similarly for a
3351 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3352 const char **old_regstart, **old_regend;
3355 /* The is_active field of reg_info helps us keep track of which (possibly
3356 nested) subexpressions we are currently in. The matched_something
3357 field of reg_info[reg_num] helps us tell whether or not we have
3358 matched any of the pattern so far this time through the reg_num-th
3359 subexpression. These two fields get reset each time through any
3360 loop their register is in. */
3361 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */
3362 register_info_type *reg_info;
3365 /* The following record the register info as found in the above
3366 variables when we find a match better than any we've seen before.
3367 This happens as we backtrack through the failure points, which in
3368 turn happens only if we have not yet matched the entire string. */
3369 unsigned best_regs_set = false;
3370 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3371 const char **best_regstart, **best_regend;
3374 /* Logically, this is `best_regend[0]'. But we don't want to have to
3375 allocate space for that if we're not allocating space for anything
3376 else (see below). Also, we never need info about register 0 for
3377 any of the other register vectors, and it seems rather a kludge to
3378 treat `best_regend' differently than the rest. So we keep track of
3379 the end of the best match so far in a separate variable. We
3380 initialize this to NULL so that when we backtrack the first time
3381 and need to test it, it's not garbage. */
3382 const char *match_end = NULL;
3384 /* Used when we pop values we don't care about. */
3385 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */
3386 const char **reg_dummy;
3387 register_info_type *reg_info_dummy;
3391 /* Counts the total number of registers pushed. */
3392 unsigned num_regs_pushed = 0;
3395 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3399 #ifdef MATCH_MAY_ALLOCATE
3400 /* Do not bother to initialize all the register variables if there are
3401 no groups in the pattern, as it takes a fair amount of time. If
3402 there are groups, we include space for register 0 (the whole
3403 pattern), even though we never use it, since it simplifies the
3404 array indexing. We should fix this. */
3407 regstart = REGEX_TALLOC (num_regs, const char *);
3408 regend = REGEX_TALLOC (num_regs, const char *);
3409 old_regstart = REGEX_TALLOC (num_regs, const char *);
3410 old_regend = REGEX_TALLOC (num_regs, const char *);
3411 best_regstart = REGEX_TALLOC (num_regs, const char *);
3412 best_regend = REGEX_TALLOC (num_regs, const char *);
3413 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3414 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3415 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3417 if (!(regstart && regend && old_regstart && old_regend && reg_info
3418 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3424 #if defined (REGEX_MALLOC)
3427 /* We must initialize all our variables to NULL, so that
3428 `FREE_VARIABLES' doesn't try to free them. */
3429 regstart = regend = old_regstart = old_regend = best_regstart
3430 = best_regend = reg_dummy = NULL;
3431 reg_info = reg_info_dummy = (register_info_type *) NULL;
3433 #endif /* REGEX_MALLOC */
3434 #endif /* MATCH_MAY_ALLOCATE */
3436 /* The starting position is bogus. */
3437 if (pos < 0 || pos > size1 + size2)
3443 /* Initialize subexpression text positions to -1 to mark ones that no
3444 start_memory/stop_memory has been seen for. Also initialize the
3445 register information struct. */
3446 for (mcnt = 1; mcnt < num_regs; mcnt++)
3448 regstart[mcnt] = regend[mcnt]
3449 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3451 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3452 IS_ACTIVE (reg_info[mcnt]) = 0;
3453 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3454 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3457 /* We move `string1' into `string2' if the latter's empty -- but not if
3458 `string1' is null. */
3459 if (size2 == 0 && string1 != NULL)
3466 end1 = string1 + size1;
3467 end2 = string2 + size2;
3469 /* Compute where to stop matching, within the two strings. */
3472 end_match_1 = string1 + stop;
3473 end_match_2 = string2;
3478 end_match_2 = string2 + stop - size1;
3481 /* `p' scans through the pattern as `d' scans through the data.
3482 `dend' is the end of the input string that `d' points within. `d'
3483 is advanced into the following input string whenever necessary, but
3484 this happens before fetching; therefore, at the beginning of the
3485 loop, `d' can be pointing at the end of a string, but it cannot
3487 if (size1 > 0 && pos <= size1)
3494 d = string2 + pos - size1;
3498 DEBUG_PRINT1 ("The compiled pattern is: ");
3499 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3500 DEBUG_PRINT1 ("The string to match is: `");
3501 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3502 DEBUG_PRINT1 ("'\n");
3504 /* This loops over pattern commands. It exits by returning from the
3505 function if the match is complete, or it drops through if the match
3506 fails at this starting point in the input data. */
3509 DEBUG_PRINT2 ("\n0x%x: ", p);
3512 { /* End of pattern means we might have succeeded. */
3513 DEBUG_PRINT1 ("end of pattern ... ");
3515 /* If we haven't matched the entire string, and we want the
3516 longest match, try backtracking. */
3517 if (d != end_match_2)
3519 DEBUG_PRINT1 ("backtracking.\n");
3521 if (!FAIL_STACK_EMPTY ())
3522 { /* More failure points to try. */
3523 boolean same_str_p = (FIRST_STRING_P (match_end)
3524 == MATCHING_IN_FIRST_STRING);
3526 /* If exceeds best match so far, save it. */
3528 || (same_str_p && d > match_end)
3529 || (!same_str_p && !MATCHING_IN_FIRST_STRING))
3531 best_regs_set = true;
3534 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3536 for (mcnt = 1; mcnt < num_regs; mcnt++)
3538 best_regstart[mcnt] = regstart[mcnt];
3539 best_regend[mcnt] = regend[mcnt];
3545 /* If no failure points, don't restore garbage. */
3546 else if (best_regs_set)
3549 /* Restore best match. It may happen that `dend ==
3550 end_match_1' while the restored d is in string2.
3551 For example, the pattern `x.*y.*z' against the
3552 strings `x-' and `y-z-', if the two strings are
3553 not consecutive in memory. */
3554 DEBUG_PRINT1 ("Restoring best registers.\n");
3557 dend = ((d >= string1 && d <= end1)
3558 ? end_match_1 : end_match_2);
3560 for (mcnt = 1; mcnt < num_regs; mcnt++)
3562 regstart[mcnt] = best_regstart[mcnt];
3563 regend[mcnt] = best_regend[mcnt];
3566 } /* d != end_match_2 */
3568 DEBUG_PRINT1 ("Accepting match.\n");
3570 /* If caller wants register contents data back, do it. */
3571 if (regs && !bufp->no_sub)
3573 /* Have the register data arrays been allocated? */
3574 if (bufp->regs_allocated == REGS_UNALLOCATED)
3575 { /* No. So allocate them with malloc. We need one
3576 extra element beyond `num_regs' for the `-1' marker
3578 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3579 regs->start = TALLOC (regs->num_regs, regoff_t);
3580 regs->end = TALLOC (regs->num_regs, regoff_t);
3581 if (regs->start == NULL || regs->end == NULL)
3583 bufp->regs_allocated = REGS_REALLOCATE;
3585 else if (bufp->regs_allocated == REGS_REALLOCATE)
3586 { /* Yes. If we need more elements than were already
3587 allocated, reallocate them. If we need fewer, just
3589 if (regs->num_regs < num_regs + 1)
3591 regs->num_regs = num_regs + 1;
3592 RETALLOC (regs->start, regs->num_regs, regoff_t);
3593 RETALLOC (regs->end, regs->num_regs, regoff_t);
3594 if (regs->start == NULL || regs->end == NULL)
3600 /* These braces fend off a "empty body in an else-statement"
3601 warning under GCC when assert expands to nothing. */
3602 assert (bufp->regs_allocated == REGS_FIXED);
3605 /* Convert the pointer data in `regstart' and `regend' to
3606 indices. Register zero has to be set differently,
3607 since we haven't kept track of any info for it. */
3608 if (regs->num_regs > 0)
3610 regs->start[0] = pos;
3611 regs->end[0] = (MATCHING_IN_FIRST_STRING ? d - string1
3612 : d - string2 + size1);
3615 /* Go through the first `min (num_regs, regs->num_regs)'
3616 registers, since that is all we initialized. */
3617 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3619 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3620 regs->start[mcnt] = regs->end[mcnt] = -1;
3623 regs->start[mcnt] = POINTER_TO_OFFSET (regstart[mcnt]);
3624 regs->end[mcnt] = POINTER_TO_OFFSET (regend[mcnt]);
3628 /* If the regs structure we return has more elements than
3629 were in the pattern, set the extra elements to -1. If
3630 we (re)allocated the registers, this is the case,
3631 because we always allocate enough to have at least one
3633 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3634 regs->start[mcnt] = regs->end[mcnt] = -1;
3635 } /* regs && !bufp->no_sub */
3638 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3639 nfailure_points_pushed, nfailure_points_popped,
3640 nfailure_points_pushed - nfailure_points_popped);
3641 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3643 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3647 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3652 /* Otherwise match next pattern command. */
3653 #ifdef SWITCH_ENUM_BUG
3654 switch ((int) ((re_opcode_t) *p++))
3656 switch ((re_opcode_t) *p++)
3659 /* Ignore these. Used to ignore the n of succeed_n's which
3660 currently have n == 0. */
3662 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3666 /* Match the next n pattern characters exactly. The following
3667 byte in the pattern defines n, and the n bytes after that
3668 are the characters to match. */
3671 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3673 /* This is written out as an if-else so we don't waste time
3674 testing `translate' inside the loop. */
3680 if (translate[(unsigned char) *d++] != (char) *p++)
3690 if (*d++ != (char) *p++) goto fail;
3694 SET_REGS_MATCHED ();
3698 /* Match any character except possibly a newline or a null. */
3700 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3704 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3705 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3708 SET_REGS_MATCHED ();
3709 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3717 register unsigned char c;
3718 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3720 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3723 c = TRANSLATE (*d); /* The character to match. */
3725 /* Cast to `unsigned' instead of `unsigned char' in case the
3726 bit list is a full 32 bytes long. */
3727 if (c < (unsigned) (*p * BYTEWIDTH)
3728 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3733 if (!not) goto fail;
3735 SET_REGS_MATCHED ();
3741 /* The beginning of a group is represented by start_memory.
3742 The arguments are the register number in the next byte, and the
3743 number of groups inner to this one in the next. The text
3744 matched within the group is recorded (in the internal
3745 registers data structure) under the register number. */
3747 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3749 /* Find out if this group can match the empty string. */
3750 p1 = p; /* To send to group_match_null_string_p. */
3752 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3753 REG_MATCH_NULL_STRING_P (reg_info[*p])
3754 = group_match_null_string_p (&p1, pend, reg_info);
3756 /* Save the position in the string where we were the last time
3757 we were at this open-group operator in case the group is
3758 operated upon by a repetition operator, e.g., with `(a*)*b'
3759 against `ab'; then we want to ignore where we are now in
3760 the string in case this attempt to match fails. */
3761 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3762 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3764 DEBUG_PRINT2 (" old_regstart: %d\n",
3765 POINTER_TO_OFFSET (old_regstart[*p]));
3768 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
3770 IS_ACTIVE (reg_info[*p]) = 1;
3771 MATCHED_SOMETHING (reg_info[*p]) = 0;
3773 /* This is the new highest active register. */
3774 highest_active_reg = *p;
3776 /* If nothing was active before, this is the new lowest active
3778 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3779 lowest_active_reg = *p;
3781 /* Move past the register number and inner group count. */
3786 /* The stop_memory opcode represents the end of a group. Its
3787 arguments are the same as start_memory's: the register
3788 number, and the number of inner groups. */
3790 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
3792 /* We need to save the string position the last time we were at
3793 this close-group operator in case the group is operated
3794 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
3795 against `aba'; then we want to ignore where we are now in
3796 the string in case this attempt to match fails. */
3797 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3798 ? REG_UNSET (regend[*p]) ? d : regend[*p]
3800 DEBUG_PRINT2 (" old_regend: %d\n",
3801 POINTER_TO_OFFSET (old_regend[*p]));
3804 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
3806 /* This register isn't active anymore. */
3807 IS_ACTIVE (reg_info[*p]) = 0;
3809 /* If this was the only register active, nothing is active
3811 if (lowest_active_reg == highest_active_reg)
3813 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3814 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3817 { /* We must scan for the new highest active register, since
3818 it isn't necessarily one less than now: consider
3819 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
3820 new highest active register is 1. */
3821 unsigned char r = *p - 1;
3822 while (r > 0 && !IS_ACTIVE (reg_info[r]))
3825 /* If we end up at register zero, that means that we saved
3826 the registers as the result of an `on_failure_jump', not
3827 a `start_memory', and we jumped to past the innermost
3828 `stop_memory'. For example, in ((.)*) we save
3829 registers 1 and 2 as a result of the *, but when we pop
3830 back to the second ), we are at the stop_memory 1.
3831 Thus, nothing is active. */
3834 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3835 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3838 highest_active_reg = r;
3841 /* If just failed to match something this time around with a
3842 group that's operated on by a repetition operator, try to
3843 force exit from the ``loop'', and restore the register
3844 information for this group that we had before trying this
3846 if ((!MATCHED_SOMETHING (reg_info[*p])
3847 || (re_opcode_t) p[-3] == start_memory)
3850 boolean is_a_jump_n = false;
3854 switch ((re_opcode_t) *p1++)
3858 case pop_failure_jump:
3859 case maybe_pop_jump:
3861 case dummy_failure_jump:
3862 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3872 /* If the next operation is a jump backwards in the pattern
3873 to an on_failure_jump right before the start_memory
3874 corresponding to this stop_memory, exit from the loop
3875 by forcing a failure after pushing on the stack the
3876 on_failure_jump's jump in the pattern, and d. */
3877 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
3878 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
3880 /* If this group ever matched anything, then restore
3881 what its registers were before trying this last
3882 failed match, e.g., with `(a*)*b' against `ab' for
3883 regstart[1], and, e.g., with `((a*)*(b*)*)*'
3884 against `aba' for regend[3].
3886 Also restore the registers for inner groups for,
3887 e.g., `((a*)(b*))*' against `aba' (register 3 would
3888 otherwise get trashed). */
3890 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
3894 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
3896 /* Restore this and inner groups' (if any) registers. */
3897 for (r = *p; r < *p + *(p + 1); r++)
3899 regstart[r] = old_regstart[r];
3901 /* xx why this test? */
3902 if ((int) old_regend[r] >= (int) regstart[r])
3903 regend[r] = old_regend[r];
3907 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3908 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
3914 /* Move past the register number and the inner group count. */
3919 /* \<digit> has been turned into a `duplicate' command which is
3920 followed by the numeric value of <digit> as the register number. */
3923 register const char *d2, *dend2;
3924 int regno = *p++; /* Get which register to match against. */
3925 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
3927 /* Can't back reference a group which we've never matched. */
3928 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
3931 /* Where in input to try to start matching. */
3932 d2 = regstart[regno];
3934 /* Where to stop matching; if both the place to start and
3935 the place to stop matching are in the same string, then
3936 set to the place to stop, otherwise, for now have to use
3937 the end of the first string. */
3939 dend2 = ((FIRST_STRING_P (regstart[regno])
3940 == FIRST_STRING_P (regend[regno]))
3941 ? regend[regno] : end_match_1);
3944 /* If necessary, advance to next segment in register
3948 if (dend2 == end_match_2) break;
3949 if (dend2 == regend[regno]) break;
3951 /* End of string1 => advance to string2. */
3953 dend2 = regend[regno];
3955 /* At end of register contents => success */
3956 if (d2 == dend2) break;
3958 /* If necessary, advance to next segment in data. */
3961 /* How many characters left in this segment to match. */
3964 /* Want how many consecutive characters we can match in
3965 one shot, so, if necessary, adjust the count. */
3966 if (mcnt > dend2 - d2)
3969 /* Compare that many; failure if mismatch, else move
3972 ? bcmp_translate (d, d2, mcnt, translate)
3973 : bcmp (d, d2, mcnt))
3975 d += mcnt, d2 += mcnt;
3981 /* begline matches the empty string at the beginning of the string
3982 (unless `not_bol' is set in `bufp'), and, if
3983 `newline_anchor' is set, after newlines. */
3985 DEBUG_PRINT1 ("EXECUTING begline.\n");
3987 if (AT_STRINGS_BEG (d))
3989 if (!bufp->not_bol) break;
3991 else if (d[-1] == '\n' && bufp->newline_anchor)
3995 /* In all other cases, we fail. */
3999 /* endline is the dual of begline. */
4001 DEBUG_PRINT1 ("EXECUTING endline.\n");
4003 if (AT_STRINGS_END (d))
4005 if (!bufp->not_eol) break;
4008 /* We have to ``prefetch'' the next character. */
4009 else if ((d == end1 ? *string2 : *d) == '\n'
4010 && bufp->newline_anchor)
4017 /* Match at the very beginning of the data. */
4019 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
4020 if (AT_STRINGS_BEG (d))
4025 /* Match at the very end of the data. */
4027 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
4028 if (AT_STRINGS_END (d))
4033 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
4034 pushes NULL as the value for the string on the stack. Then
4035 `pop_failure_point' will keep the current value for the
4036 string, instead of restoring it. To see why, consider
4037 matching `foo\nbar' against `.*\n'. The .* matches the foo;
4038 then the . fails against the \n. But the next thing we want
4039 to do is match the \n against the \n; if we restored the
4040 string value, we would be back at the foo.
4042 Because this is used only in specific cases, we don't need to
4043 check all the things that `on_failure_jump' does, to make
4044 sure the right things get saved on the stack. Hence we don't
4045 share its code. The only reason to push anything on the
4046 stack at all is that otherwise we would have to change
4047 `anychar's code to do something besides goto fail in this
4048 case; that seems worse than this. */
4049 case on_failure_keep_string_jump:
4050 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
4052 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4053 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
4055 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
4059 /* Uses of on_failure_jump:
4061 Each alternative starts with an on_failure_jump that points
4062 to the beginning of the next alternative. Each alternative
4063 except the last ends with a jump that in effect jumps past
4064 the rest of the alternatives. (They really jump to the
4065 ending jump of the following alternative, because tensioning
4066 these jumps is a hassle.)
4068 Repeats start with an on_failure_jump that points past both
4069 the repetition text and either the following jump or
4070 pop_failure_jump back to this on_failure_jump. */
4071 case on_failure_jump:
4073 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
4075 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4076 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
4078 /* If this on_failure_jump comes right before a group (i.e.,
4079 the original * applied to a group), save the information
4080 for that group and all inner ones, so that if we fail back
4081 to this point, the group's information will be correct.
4082 For example, in \(a*\)*\1, we need the preceding group,
4083 and in \(\(a*\)b*\)\2, we need the inner group. */
4085 /* We can't use `p' to check ahead because we push
4086 a failure point to `p + mcnt' after we do this. */
4089 /* We need to skip no_op's before we look for the
4090 start_memory in case this on_failure_jump is happening as
4091 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
4093 while (p1 < pend && (re_opcode_t) *p1 == no_op)
4096 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
4098 /* We have a new highest active register now. This will
4099 get reset at the start_memory we are about to get to,
4100 but we will have saved all the registers relevant to
4101 this repetition op, as described above. */
4102 highest_active_reg = *(p1 + 1) + *(p1 + 2);
4103 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
4104 lowest_active_reg = *(p1 + 1);
4107 DEBUG_PRINT1 (":\n");
4108 PUSH_FAILURE_POINT (p + mcnt, d, -2);
4112 /* A smart repeat ends with `maybe_pop_jump'.
4113 We change it to either `pop_failure_jump' or `jump'. */
4114 case maybe_pop_jump:
4115 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4116 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
4118 register unsigned char *p2 = p;
4120 /* Compare the beginning of the repeat with what in the
4121 pattern follows its end. If we can establish that there
4122 is nothing that they would both match, i.e., that we
4123 would have to backtrack because of (as in, e.g., `a*a')
4124 then we can change to pop_failure_jump, because we'll
4125 never have to backtrack.
4127 This is not true in the case of alternatives: in
4128 `(a|ab)*' we do need to backtrack to the `ab' alternative
4129 (e.g., if the string was `ab'). But instead of trying to
4130 detect that here, the alternative has put on a dummy
4131 failure point which is what we will end up popping. */
4133 /* Skip over open/close-group commands. */
4134 while (p2 + 2 < pend
4135 && ((re_opcode_t) *p2 == stop_memory
4136 || (re_opcode_t) *p2 == start_memory))
4137 p2 += 3; /* Skip over args, too. */
4139 /* If we're at the end of the pattern, we can change. */
4142 /* Consider what happens when matching ":\(.*\)"
4143 against ":/". I don't really understand this code
4145 p[-3] = (unsigned char) pop_failure_jump;
4147 (" End of pattern: change to `pop_failure_jump'.\n");
4150 else if ((re_opcode_t) *p2 == exactn
4151 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4153 register unsigned char c
4154 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4157 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4158 to the `maybe_finalize_jump' of this case. Examine what
4160 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4162 p[-3] = (unsigned char) pop_failure_jump;
4163 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4167 else if ((re_opcode_t) p1[3] == charset
4168 || (re_opcode_t) p1[3] == charset_not)
4170 int not = (re_opcode_t) p1[3] == charset_not;
4172 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4173 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4176 /* `not' is equal to 1 if c would match, which means
4177 that we can't change to pop_failure_jump. */
4180 p[-3] = (unsigned char) pop_failure_jump;
4181 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4186 p -= 2; /* Point at relative address again. */
4187 if ((re_opcode_t) p[-1] != pop_failure_jump)
4189 p[-1] = (unsigned char) jump;
4190 DEBUG_PRINT1 (" Match => jump.\n");
4191 goto unconditional_jump;
4193 /* Note fall through. */
4196 /* The end of a simple repeat has a pop_failure_jump back to
4197 its matching on_failure_jump, where the latter will push a
4198 failure point. The pop_failure_jump takes off failure
4199 points put on by this pop_failure_jump's matching
4200 on_failure_jump; we got through the pattern to here from the
4201 matching on_failure_jump, so didn't fail. */
4202 case pop_failure_jump:
4204 /* We need to pass separate storage for the lowest and
4205 highest registers, even though we don't care about the
4206 actual values. Otherwise, we will restore only one
4207 register from the stack, since lowest will == highest in
4208 `pop_failure_point'. */
4209 unsigned dummy_low_reg, dummy_high_reg;
4210 unsigned char *pdummy;
4213 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4214 POP_FAILURE_POINT (sdummy, pdummy,
4215 dummy_low_reg, dummy_high_reg,
4216 reg_dummy, reg_dummy, reg_info_dummy);
4218 /* Note fall through. */
4221 /* Unconditionally jump (without popping any failure points). */
4224 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4225 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4226 p += mcnt; /* Do the jump. */
4227 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4231 /* We need this opcode so we can detect where alternatives end
4232 in `group_match_null_string_p' et al. */
4234 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4235 goto unconditional_jump;
4238 /* Normally, the on_failure_jump pushes a failure point, which
4239 then gets popped at pop_failure_jump. We will end up at
4240 pop_failure_jump, also, and with a pattern of, say, `a+', we
4241 are skipping over the on_failure_jump, so we have to push
4242 something meaningless for pop_failure_jump to pop. */
4243 case dummy_failure_jump:
4244 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4245 /* It doesn't matter what we push for the string here. What
4246 the code at `fail' tests is the value for the pattern. */
4247 PUSH_FAILURE_POINT (0, 0, -2);
4248 goto unconditional_jump;
4251 /* At the end of an alternative, we need to push a dummy failure
4252 point in case we are followed by a `pop_failure_jump', because
4253 we don't want the failure point for the alternative to be
4254 popped. For example, matching `(a|ab)*' against `aab'
4255 requires that we match the `ab' alternative. */
4256 case push_dummy_failure:
4257 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4258 /* See comments just above at `dummy_failure_jump' about the
4260 PUSH_FAILURE_POINT (0, 0, -2);
4263 /* Have to succeed matching what follows at least n times.
4264 After that, handle like `on_failure_jump'. */
4266 EXTRACT_NUMBER (mcnt, p + 2);
4267 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4270 /* Originally, this is how many times we HAVE to succeed. */
4275 STORE_NUMBER_AND_INCR (p, mcnt);
4276 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4280 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4281 p[2] = (unsigned char) no_op;
4282 p[3] = (unsigned char) no_op;
4288 EXTRACT_NUMBER (mcnt, p + 2);
4289 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4291 /* Originally, this is how many times we CAN jump. */
4295 STORE_NUMBER (p + 2, mcnt);
4296 goto unconditional_jump;
4298 /* If don't have to jump any more, skip over the rest of command. */
4305 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4307 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4309 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4310 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4311 STORE_NUMBER (p1, mcnt);
4316 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4317 if (AT_WORD_BOUNDARY (d))
4322 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4323 if (AT_WORD_BOUNDARY (d))
4328 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4329 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4334 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4335 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4336 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4343 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4344 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4349 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4350 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4355 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4356 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4359 #else /* not emacs19 */
4361 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4362 if (PTR_CHAR_POS ((unsigned char *) d) + 1 != point)
4365 #endif /* not emacs19 */
4368 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4373 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4377 if (SYNTAX (*d++) != (enum syntaxcode) mcnt)
4379 SET_REGS_MATCHED ();
4383 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4385 goto matchnotsyntax;
4388 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4392 if (SYNTAX (*d++) == (enum syntaxcode) mcnt)
4394 SET_REGS_MATCHED ();
4397 #else /* not emacs */
4399 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4401 if (!WORDCHAR_P (d))
4403 SET_REGS_MATCHED ();
4408 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4412 SET_REGS_MATCHED ();
4415 #endif /* not emacs */
4420 continue; /* Successfully executed one pattern command; keep going. */
4423 /* We goto here if a matching operation fails. */
4425 if (!FAIL_STACK_EMPTY ())
4426 { /* A restart point is known. Restore to that state. */
4427 DEBUG_PRINT1 ("\nFAIL:\n");
4428 POP_FAILURE_POINT (d, p,
4429 lowest_active_reg, highest_active_reg,
4430 regstart, regend, reg_info);
4432 /* If this failure point is a dummy, try the next one. */
4436 /* If we failed to the end of the pattern, don't examine *p. */
4440 boolean is_a_jump_n = false;
4442 /* If failed to a backwards jump that's part of a repetition
4443 loop, need to pop this failure point and use the next one. */
4444 switch ((re_opcode_t) *p)
4448 case maybe_pop_jump:
4449 case pop_failure_jump:
4452 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4455 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4457 && (re_opcode_t) *p1 == on_failure_jump))
4465 if (d >= string1 && d <= end1)
4469 break; /* Matching at this starting point really fails. */
4473 goto restore_best_regs;
4477 return -1; /* Failure to match. */
4480 /* Subroutine definitions for re_match_2. */
4483 /* We are passed P pointing to a register number after a start_memory.
4485 Return true if the pattern up to the corresponding stop_memory can
4486 match the empty string, and false otherwise.
4488 If we find the matching stop_memory, sets P to point to one past its number.
4489 Otherwise, sets P to an undefined byte less than or equal to END.
4491 We don't handle duplicates properly (yet). */
4494 group_match_null_string_p (p, end, reg_info)
4495 unsigned char **p, *end;
4496 register_info_type *reg_info;
4499 /* Point to after the args to the start_memory. */
4500 unsigned char *p1 = *p + 2;
4504 /* Skip over opcodes that can match nothing, and return true or
4505 false, as appropriate, when we get to one that can't, or to the
4506 matching stop_memory. */
4508 switch ((re_opcode_t) *p1)
4510 /* Could be either a loop or a series of alternatives. */
4511 case on_failure_jump:
4513 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4515 /* If the next operation is not a jump backwards in the
4520 /* Go through the on_failure_jumps of the alternatives,
4521 seeing if any of the alternatives cannot match nothing.
4522 The last alternative starts with only a jump,
4523 whereas the rest start with on_failure_jump and end
4524 with a jump, e.g., here is the pattern for `a|b|c':
4526 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4527 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4530 So, we have to first go through the first (n-1)
4531 alternatives and then deal with the last one separately. */
4534 /* Deal with the first (n-1) alternatives, which start
4535 with an on_failure_jump (see above) that jumps to right
4536 past a jump_past_alt. */
4538 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4540 /* `mcnt' holds how many bytes long the alternative
4541 is, including the ending `jump_past_alt' and
4544 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4548 /* Move to right after this alternative, including the
4552 /* Break if it's the beginning of an n-th alternative
4553 that doesn't begin with an on_failure_jump. */
4554 if ((re_opcode_t) *p1 != on_failure_jump)
4557 /* Still have to check that it's not an n-th
4558 alternative that starts with an on_failure_jump. */
4560 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4561 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4563 /* Get to the beginning of the n-th alternative. */
4569 /* Deal with the last alternative: go back and get number
4570 of the `jump_past_alt' just before it. `mcnt' contains
4571 the length of the alternative. */
4572 EXTRACT_NUMBER (mcnt, p1 - 2);
4574 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4577 p1 += mcnt; /* Get past the n-th alternative. */
4583 assert (p1[1] == **p);
4589 if (!common_op_match_null_string_p (&p1, end, reg_info))
4592 } /* while p1 < end */
4595 } /* group_match_null_string_p */
4598 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4599 It expects P to be the first byte of a single alternative and END one
4600 byte past the last. The alternative can contain groups. */
4603 alt_match_null_string_p (p, end, reg_info)
4604 unsigned char *p, *end;
4605 register_info_type *reg_info;
4608 unsigned char *p1 = p;
4612 /* Skip over opcodes that can match nothing, and break when we get
4613 to one that can't. */
4615 switch ((re_opcode_t) *p1)
4618 case on_failure_jump:
4620 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4625 if (!common_op_match_null_string_p (&p1, end, reg_info))
4628 } /* while p1 < end */
4631 } /* alt_match_null_string_p */
4634 /* Deals with the ops common to group_match_null_string_p and
4635 alt_match_null_string_p.
4637 Sets P to one after the op and its arguments, if any. */
4640 common_op_match_null_string_p (p, end, reg_info)
4641 unsigned char **p, *end;
4642 register_info_type *reg_info;
4647 unsigned char *p1 = *p;
4649 switch ((re_opcode_t) *p1++)
4669 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
4670 ret = group_match_null_string_p (&p1, end, reg_info);
4672 /* Have to set this here in case we're checking a group which
4673 contains a group and a back reference to it. */
4675 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
4676 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
4682 /* If this is an optimized succeed_n for zero times, make the jump. */
4684 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4692 /* Get to the number of times to succeed. */
4694 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4699 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4707 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
4715 /* All other opcodes mean we cannot match the empty string. */
4721 } /* common_op_match_null_string_p */
4724 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
4725 bytes; nonzero otherwise. */
4728 bcmp_translate (s1, s2, len, translate)
4729 unsigned char *s1, *s2;
4733 register unsigned char *p1 = s1, *p2 = s2;
4736 if (translate[*p1++] != translate[*p2++]) return 1;
4742 /* Entry points for GNU code. */
4744 /* re_compile_pattern is the GNU regular expression compiler: it
4745 compiles PATTERN (of length SIZE) and puts the result in BUFP.
4746 Returns 0 if the pattern was valid, otherwise an error string.
4748 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
4749 are set in BUFP on entry.
4751 We call regex_compile to do the actual compilation. */
4754 re_compile_pattern (pattern, length, bufp)
4755 const char *pattern;
4757 struct re_pattern_buffer *bufp;
4761 /* GNU code is written to assume at least RE_NREGS registers will be set
4762 (and at least one extra will be -1). */
4763 bufp->regs_allocated = REGS_UNALLOCATED;
4765 /* And GNU code determines whether or not to get register information
4766 by passing null for the REGS argument to re_match, etc., not by
4770 /* Match anchors at newline. */
4771 bufp->newline_anchor = 1;
4773 ret = regex_compile (pattern, length, re_syntax_options, bufp);
4775 return re_error_msg[(int) ret];
4778 /* Entry points compatible with 4.2 BSD regex library. We don't define
4779 them if this is an Emacs or POSIX compilation. */
4781 #if !defined (emacs) && !defined (_POSIX_SOURCE)
4783 /* BSD has one and only one pattern buffer. */
4784 static struct re_pattern_buffer re_comp_buf;
4794 if (!re_comp_buf.buffer)
4795 return "No previous regular expression";
4799 if (!re_comp_buf.buffer)
4801 re_comp_buf.buffer = (unsigned char *) malloc (200);
4802 if (re_comp_buf.buffer == NULL)
4803 return "Memory exhausted";
4804 re_comp_buf.allocated = 200;
4806 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
4807 if (re_comp_buf.fastmap == NULL)
4808 return "Memory exhausted";
4811 /* Since `re_exec' always passes NULL for the `regs' argument, we
4812 don't need to initialize the pattern buffer fields which affect it. */
4814 /* Match anchors at newlines. */
4815 re_comp_buf.newline_anchor = 1;
4817 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
4819 /* Yes, we're discarding `const' here. */
4820 return (char *) re_error_msg[(int) ret];
4828 const int len = strlen (s);
4830 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
4832 #endif /* not emacs and not _POSIX_SOURCE */
4834 /* POSIX.2 functions. Don't define these for Emacs. */
4838 /* regcomp takes a regular expression as a string and compiles it.
4840 PREG is a regex_t *. We do not expect any fields to be initialized,
4841 since POSIX says we shouldn't. Thus, we set
4843 `buffer' to the compiled pattern;
4844 `used' to the length of the compiled pattern;
4845 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
4846 REG_EXTENDED bit in CFLAGS is set; otherwise, to
4847 RE_SYNTAX_POSIX_BASIC;
4848 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
4849 `fastmap' and `fastmap_accurate' to zero;
4850 `re_nsub' to the number of subexpressions in PATTERN.
4852 PATTERN is the address of the pattern string.
4854 CFLAGS is a series of bits which affect compilation.
4856 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
4857 use POSIX basic syntax.
4859 If REG_NEWLINE is set, then . and [^...] don't match newline.
4860 Also, regexec will try a match beginning after every newline.
4862 If REG_ICASE is set, then we considers upper- and lowercase
4863 versions of letters to be equivalent when matching.
4865 If REG_NOSUB is set, then when PREG is passed to regexec, that
4866 routine will report only success or failure, and nothing about the
4869 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
4870 the return codes and their meanings.) */
4873 regcomp (preg, pattern, cflags)
4875 const char *pattern;
4880 = (cflags & REG_EXTENDED) ?
4881 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
4883 /* regex_compile will allocate the space for the compiled pattern. */
4885 preg->allocated = 0;
4888 /* Don't bother to use a fastmap when searching. This simplifies the
4889 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
4890 characters after newlines into the fastmap. This way, we just try
4894 if (cflags & REG_ICASE)
4898 preg->translate = (char *) malloc (CHAR_SET_SIZE);
4899 if (preg->translate == NULL)
4900 return (int) REG_ESPACE;
4902 /* Map uppercase characters to corresponding lowercase ones. */
4903 for (i = 0; i < CHAR_SET_SIZE; i++)
4904 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
4907 preg->translate = NULL;
4909 /* If REG_NEWLINE is set, newlines are treated differently. */
4910 if (cflags & REG_NEWLINE)
4911 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
4912 syntax &= ~RE_DOT_NEWLINE;
4913 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
4914 /* It also changes the matching behavior. */
4915 preg->newline_anchor = 1;
4918 preg->newline_anchor = 0;
4920 preg->no_sub = !!(cflags & REG_NOSUB);
4922 /* POSIX says a null character in the pattern terminates it, so we
4923 can use strlen here in compiling the pattern. */
4924 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
4926 /* POSIX doesn't distinguish between an unmatched open-group and an
4927 unmatched close-group: both are REG_EPAREN. */
4928 if (ret == REG_ERPAREN) ret = REG_EPAREN;
4934 /* regexec searches for a given pattern, specified by PREG, in the
4937 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
4938 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
4939 least NMATCH elements, and we set them to the offsets of the
4940 corresponding matched substrings.
4942 EFLAGS specifies `execution flags' which affect matching: if
4943 REG_NOTBOL is set, then ^ does not match at the beginning of the
4944 string; if REG_NOTEOL is set, then $ does not match at the end.
4946 We return 0 if we find a match and REG_NOMATCH if not. */
4949 regexec (preg, string, nmatch, pmatch, eflags)
4950 const regex_t *preg;
4953 regmatch_t pmatch[];
4957 struct re_registers regs;
4958 regex_t private_preg;
4959 int len = strlen (string);
4960 boolean want_reg_info = !preg->no_sub && nmatch > 0;
4962 private_preg = *preg;
4964 private_preg.not_bol = !!(eflags & REG_NOTBOL);
4965 private_preg.not_eol = !!(eflags & REG_NOTEOL);
4967 /* The user has told us exactly how many registers to return
4968 information about, via `nmatch'. We have to pass that on to the
4969 matching routines. */
4970 private_preg.regs_allocated = REGS_FIXED;
4974 regs.num_regs = nmatch;
4975 regs.start = TALLOC (nmatch, regoff_t);
4976 regs.end = TALLOC (nmatch, regoff_t);
4977 if (regs.start == NULL || regs.end == NULL)
4978 return (int) REG_NOMATCH;
4981 /* Perform the searching operation. */
4982 ret = re_search (&private_preg, string, len,
4983 /* start: */ 0, /* range: */ len,
4984 want_reg_info ? ®s : (struct re_registers *) 0);
4986 /* Copy the register information to the POSIX structure. */
4993 for (r = 0; r < nmatch; r++)
4995 pmatch[r].rm_so = regs.start[r];
4996 pmatch[r].rm_eo = regs.end[r];
5000 /* If we needed the temporary register info, free the space now. */
5005 /* We want zero return to mean success, unlike `re_search'. */
5006 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
5010 /* Returns a message corresponding to an error code, ERRCODE, returned
5011 from either regcomp or regexec. We don't use PREG here. */
5014 regerror (errcode, preg, errbuf, errbuf_size)
5016 const regex_t *preg;
5024 || errcode >= (sizeof (re_error_msg) / sizeof (re_error_msg[0])))
5025 /* Only error codes returned by the rest of the code should be passed
5026 to this routine. If we are given anything else, or if other regex
5027 code generates an invalid error code, then the program has a bug.
5028 Dump core so we can fix it. */
5031 msg = re_error_msg[errcode];
5033 /* POSIX doesn't require that we do anything in this case, but why
5038 msg_size = strlen (msg) + 1; /* Includes the null. */
5040 if (errbuf_size != 0)
5042 if (msg_size > errbuf_size)
5044 strncpy (errbuf, msg, errbuf_size - 1);
5045 errbuf[errbuf_size - 1] = 0;
5048 strcpy (errbuf, msg);
5055 /* Free dynamically allocated space used by PREG. */
5061 if (preg->buffer != NULL)
5062 free (preg->buffer);
5063 preg->buffer = NULL;
5065 preg->allocated = 0;
5068 if (preg->fastmap != NULL)
5069 free (preg->fastmap);
5070 preg->fastmap = NULL;
5071 preg->fastmap_accurate = 0;
5073 if (preg->translate != NULL)
5074 free (preg->translate);
5075 preg->translate = NULL;
5078 #endif /* not emacs */
5082 make-backup-files: t
5084 trim-versions-without-asking: nil