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)
31 /* We need this for `regex.h', and perhaps for the Emacs include files. */
32 #include <sys/types.h>
43 /* The `emacs' switch turns on certain matching commands
44 that make sense only in Emacs. */
51 /* Emacs uses `NULL' as a predicate. */
56 /* We used to test for `BSTRING' here, but only GCC and Emacs define
57 `BSTRING', as far as I know, and neither of them use this code. */
58 #if HAVE_STRING_H || STDC_HEADERS
61 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
64 #define bcopy(s, d, n) memcpy ((d), (s), (n))
67 #define bzero(s, n) memset ((s), 0, (n))
81 /* Define the syntax stuff for \<, \>, etc. */
83 /* This must be nonzero for the wordchar and notwordchar pattern
84 commands in re_match_2. */
91 extern char *re_syntax_table;
93 #else /* not SYNTAX_TABLE */
95 /* How many characters in the character set. */
96 #define CHAR_SET_SIZE 256
98 static char re_syntax_table[CHAR_SET_SIZE];
109 bzero (re_syntax_table, sizeof re_syntax_table);
111 for (c = 'a'; c <= 'z'; c++)
112 re_syntax_table[c] = Sword;
114 for (c = 'A'; c <= 'Z'; c++)
115 re_syntax_table[c] = Sword;
117 for (c = '0'; c <= '9'; c++)
118 re_syntax_table[c] = Sword;
120 re_syntax_table['_'] = Sword;
125 #endif /* not SYNTAX_TABLE */
127 #define SYNTAX(c) re_syntax_table[c]
129 #endif /* not emacs */
131 /* Get the interface, including the syntax bits. */
134 /* isalpha etc. are used for the character classes. */
142 #define ISBLANK(c) (isascii (c) && isblank (c))
144 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
147 #define ISGRAPH(c) (isascii (c) && isgraph (c))
149 #define ISGRAPH(c) (isascii (c) && isprint (c) && !isspace (c))
152 #define ISPRINT(c) (isascii (c) && isprint (c))
153 #define ISDIGIT(c) (isascii (c) && isdigit (c))
154 #define ISALNUM(c) (isascii (c) && isalnum (c))
155 #define ISALPHA(c) (isascii (c) && isalpha (c))
156 #define ISCNTRL(c) (isascii (c) && iscntrl (c))
157 #define ISLOWER(c) (isascii (c) && islower (c))
158 #define ISPUNCT(c) (isascii (c) && ispunct (c))
159 #define ISSPACE(c) (isascii (c) && isspace (c))
160 #define ISUPPER(c) (isascii (c) && isupper (c))
161 #define ISXDIGIT(c) (isascii (c) && isxdigit (c))
167 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
168 since ours (we hope) works properly with all combinations of
169 machines, compilers, `char' and `unsigned char' argument types.
170 (Per Bothner suggested the basic approach.) */
171 #undef SIGN_EXTEND_CHAR
173 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
174 #else /* not __STDC__ */
175 /* As in Harbison and Steele. */
176 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
179 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
180 use `alloca' instead of `malloc'. This is because using malloc in
181 re_search* or re_match* could cause memory leaks when C-g is used in
182 Emacs; also, malloc is slower and causes storage fragmentation. On
183 the other hand, malloc is more portable, and easier to debug.
185 Because we sometimes use alloca, some routines have to be macros,
186 not functions -- `alloca'-allocated space disappears at the end of the
187 function it is called in. */
191 #define REGEX_ALLOCATE malloc
192 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
194 #else /* not REGEX_MALLOC */
196 /* Emacs already defines alloca, sometimes. */
199 /* Make alloca work the best possible way. */
201 #define alloca __builtin_alloca
202 #else /* not __GNUC__ */
205 #else /* not __GNUC__ or HAVE_ALLOCA_H */
206 #ifndef _AIX /* Already did AIX, up at the top. */
208 #endif /* not _AIX */
209 #endif /* not HAVE_ALLOCA_H */
210 #endif /* not __GNUC__ */
212 #endif /* not alloca */
214 #define REGEX_ALLOCATE alloca
216 /* Assumes a `char *destination' variable. */
217 #define REGEX_REALLOCATE(source, osize, nsize) \
218 (destination = (char *) alloca (nsize), \
219 bcopy (source, destination, osize), \
222 #endif /* not REGEX_MALLOC */
225 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
226 `string1' or just past its end. This works if PTR is NULL, which is
228 #define FIRST_STRING_P(ptr) \
229 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
231 /* (Re)Allocate N items of type T using malloc, or fail. */
232 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
233 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
234 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
236 #define BYTEWIDTH 8 /* In bits. */
238 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
240 #define MAX(a, b) ((a) > (b) ? (a) : (b))
241 #define MIN(a, b) ((a) < (b) ? (a) : (b))
243 typedef char boolean;
247 /* These are the command codes that appear in compiled regular
248 expressions. Some opcodes are followed by argument bytes. A
249 command code can specify any interpretation whatsoever for its
250 arguments. Zero bytes may appear in the compiled regular expression.
252 The value of `exactn' is needed in search.c (search_buffer) in Emacs.
253 So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of
254 `exactn' we use here must also be 1. */
260 /* Followed by one byte giving n, then by n literal bytes. */
263 /* Matches any (more or less) character. */
266 /* Matches any one char belonging to specified set. First
267 following byte is number of bitmap bytes. Then come bytes
268 for a bitmap saying which chars are in. Bits in each byte
269 are ordered low-bit-first. A character is in the set if its
270 bit is 1. A character too large to have a bit in the map is
271 automatically not in the set. */
274 /* Same parameters as charset, but match any character that is
275 not one of those specified. */
278 /* Start remembering the text that is matched, for storing in a
279 register. Followed by one byte with the register number, in
280 the range 0 to one less than the pattern buffer's re_nsub
281 field. Then followed by one byte with the number of groups
282 inner to this one. (This last has to be part of the
283 start_memory only because we need it in the on_failure_jump
287 /* Stop remembering the text that is matched and store it in a
288 memory register. Followed by one byte with the register
289 number, in the range 0 to one less than `re_nsub' in the
290 pattern buffer, and one byte with the number of inner groups,
291 just like `start_memory'. (We need the number of inner
292 groups here because we don't have any easy way of finding the
293 corresponding start_memory when we're at a stop_memory.) */
296 /* Match a duplicate of something remembered. Followed by one
297 byte containing the register number. */
300 /* Fail unless at beginning of line. */
303 /* Fail unless at end of line. */
306 /* Succeeds if at beginning of buffer (if emacs) or at beginning
307 of string to be matched (if not). */
310 /* Analogously, for end of buffer/string. */
313 /* Followed by two byte relative address to which to jump. */
316 /* Same as jump, but marks the end of an alternative. */
319 /* Followed by two-byte relative address of place to resume at
320 in case of failure. */
323 /* Like on_failure_jump, but pushes a placeholder instead of the
324 current string position when executed. */
325 on_failure_keep_string_jump,
327 /* Throw away latest failure point and then jump to following
328 two-byte relative address. */
331 /* Change to pop_failure_jump if know won't have to backtrack to
332 match; otherwise change to jump. This is used to jump
333 back to the beginning of a repeat. If what follows this jump
334 clearly won't match what the repeat does, such that we can be
335 sure that there is no use backtracking out of repetitions
336 already matched, then we change it to a pop_failure_jump.
337 Followed by two-byte address. */
340 /* Jump to following two-byte address, and push a dummy failure
341 point. This failure point will be thrown away if an attempt
342 is made to use it for a failure. A `+' construct makes this
343 before the first repeat. Also used as an intermediary kind
344 of jump when compiling an alternative. */
347 /* Push a dummy failure point and continue. Used at the end of
351 /* Followed by two-byte relative address and two-byte number n.
352 After matching N times, jump to the address upon failure. */
355 /* Followed by two-byte relative address, and two-byte number n.
356 Jump to the address N times, then fail. */
359 /* Set the following two-byte relative address to the
360 subsequent two-byte number. The address *includes* the two
364 wordchar, /* Matches any word-constituent character. */
365 notwordchar, /* Matches any char that is not a word-constituent. */
367 wordbeg, /* Succeeds if at word beginning. */
368 wordend, /* Succeeds if at word end. */
370 wordbound, /* Succeeds if at a word boundary. */
371 notwordbound /* Succeeds if not at a word boundary. */
374 ,before_dot, /* Succeeds if before point. */
375 at_dot, /* Succeeds if at point. */
376 after_dot, /* Succeeds if after point. */
378 /* Matches any character whose syntax is specified. Followed by
379 a byte which contains a syntax code, e.g., Sword. */
382 /* Matches any character whose syntax is not that specified. */
387 /* Common operations on the compiled pattern. */
389 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
391 #define STORE_NUMBER(destination, number) \
393 (destination)[0] = (number) & 0377; \
394 (destination)[1] = (number) >> 8; \
397 /* Same as STORE_NUMBER, except increment DESTINATION to
398 the byte after where the number is stored. Therefore, DESTINATION
399 must be an lvalue. */
401 #define STORE_NUMBER_AND_INCR(destination, number) \
403 STORE_NUMBER (destination, number); \
404 (destination) += 2; \
407 /* Put into DESTINATION a number stored in two contiguous bytes starting
410 #define EXTRACT_NUMBER(destination, source) \
412 (destination) = *(source) & 0377; \
413 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
418 extract_number (dest, source)
420 unsigned char *source;
422 int temp = SIGN_EXTEND_CHAR (*(source + 1));
423 *dest = *source & 0377;
427 #ifndef EXTRACT_MACROS /* To debug the macros. */
428 #undef EXTRACT_NUMBER
429 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
430 #endif /* not EXTRACT_MACROS */
434 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
435 SOURCE must be an lvalue. */
437 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
439 EXTRACT_NUMBER (destination, source); \
445 extract_number_and_incr (destination, source)
447 unsigned char **source;
449 extract_number (destination, *source);
453 #ifndef EXTRACT_MACROS
454 #undef EXTRACT_NUMBER_AND_INCR
455 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
456 extract_number_and_incr (&dest, &src)
457 #endif /* not EXTRACT_MACROS */
461 /* If DEBUG is defined, Regex prints many voluminous messages about what
462 it is doing (if the variable `debug' is nonzero). If linked with the
463 main program in `iregex.c', you can enter patterns and strings
464 interactively. And if linked with the main program in `main.c' and
465 the other test files, you can run the already-written tests. */
469 /* We use standard I/O for debugging. */
472 /* It is useful to test things that ``must'' be true when debugging. */
475 static int debug = 0;
477 #define DEBUG_STATEMENT(e) e
478 #define DEBUG_PRINT1(x) if (debug) printf (x)
479 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
480 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
481 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
482 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
483 if (debug) print_partial_compiled_pattern (s, e)
484 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
485 if (debug) print_double_string (w, s1, sz1, s2, sz2)
488 extern void printchar ();
490 /* Print the fastmap in human-readable form. */
493 print_fastmap (fastmap)
496 unsigned was_a_range = 0;
499 while (i < (1 << BYTEWIDTH))
505 while (i < (1 << BYTEWIDTH) && fastmap[i])
521 /* Print a compiled pattern string in human-readable form, starting at
522 the START pointer into it and ending just before the pointer END. */
525 print_partial_compiled_pattern (start, end)
526 unsigned char *start;
530 unsigned char *p = start;
531 unsigned char *pend = end;
539 /* Loop over pattern commands. */
542 switch ((re_opcode_t) *p++)
550 printf ("/exactn/%d", mcnt);
561 printf ("/start_memory/%d/%d", mcnt, *p++);
566 printf ("/stop_memory/%d/%d", mcnt, *p++);
570 printf ("/duplicate/%d", *p++);
582 printf ("/charset%s",
583 (re_opcode_t) *(p - 1) == charset_not ? "_not" : "");
585 assert (p + *p < pend);
587 for (c = 0; c < *p; c++)
590 unsigned char map_byte = p[1 + c];
594 for (bit = 0; bit < BYTEWIDTH; bit++)
595 if (map_byte & (1 << bit))
596 printchar (c * BYTEWIDTH + bit);
610 case on_failure_jump:
611 extract_number_and_incr (&mcnt, &p);
612 printf ("/on_failure_jump/0/%d", mcnt);
615 case on_failure_keep_string_jump:
616 extract_number_and_incr (&mcnt, &p);
617 printf ("/on_failure_keep_string_jump/0/%d", mcnt);
620 case dummy_failure_jump:
621 extract_number_and_incr (&mcnt, &p);
622 printf ("/dummy_failure_jump/0/%d", mcnt);
625 case push_dummy_failure:
626 printf ("/push_dummy_failure");
630 extract_number_and_incr (&mcnt, &p);
631 printf ("/maybe_pop_jump/0/%d", mcnt);
634 case pop_failure_jump:
635 extract_number_and_incr (&mcnt, &p);
636 printf ("/pop_failure_jump/0/%d", mcnt);
640 extract_number_and_incr (&mcnt, &p);
641 printf ("/jump_past_alt/0/%d", mcnt);
645 extract_number_and_incr (&mcnt, &p);
646 printf ("/jump/0/%d", mcnt);
650 extract_number_and_incr (&mcnt, &p);
651 extract_number_and_incr (&mcnt2, &p);
652 printf ("/succeed_n/0/%d/0/%d", mcnt, mcnt2);
656 extract_number_and_incr (&mcnt, &p);
657 extract_number_and_incr (&mcnt2, &p);
658 printf ("/jump_n/0/%d/0/%d", mcnt, mcnt2);
662 extract_number_and_incr (&mcnt, &p);
663 extract_number_and_incr (&mcnt2, &p);
664 printf ("/set_number_at/0/%d/0/%d", mcnt, mcnt2);
668 printf ("/wordbound");
672 printf ("/notwordbound");
684 printf ("/before_dot");
692 printf ("/after_dot");
696 printf ("/syntaxspec");
698 printf ("/%d", mcnt);
702 printf ("/notsyntaxspec");
704 printf ("/%d", mcnt);
709 printf ("/wordchar");
713 printf ("/notwordchar");
725 printf ("?%d", *(p-1));
733 print_compiled_pattern (bufp)
734 struct re_pattern_buffer *bufp;
736 unsigned char *buffer = bufp->buffer;
738 print_partial_compiled_pattern (buffer, buffer + bufp->used);
739 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
741 if (bufp->fastmap_accurate && bufp->fastmap)
743 printf ("fastmap: ");
744 print_fastmap (bufp->fastmap);
747 printf ("re_nsub: %d\t", bufp->re_nsub);
748 printf ("regs_alloc: %d\t", bufp->regs_allocated);
749 printf ("can_be_null: %d\t", bufp->can_be_null);
750 printf ("newline_anchor: %d\n", bufp->newline_anchor);
751 printf ("no_sub: %d\t", bufp->no_sub);
752 printf ("not_bol: %d\t", bufp->not_bol);
753 printf ("not_eol: %d\t", bufp->not_eol);
754 printf ("syntax: %d\n", bufp->syntax);
755 /* Perhaps we should print the translate table? */
760 print_double_string (where, string1, size1, string2, size2)
773 if (FIRST_STRING_P (where))
775 for (this_char = where - string1; this_char < size1; this_char++)
776 printchar (string1[this_char]);
781 for (this_char = where - string2; this_char < size2; this_char++)
782 printchar (string2[this_char]);
786 #else /* not DEBUG */
791 #define DEBUG_STATEMENT(e)
792 #define DEBUG_PRINT1(x)
793 #define DEBUG_PRINT2(x1, x2)
794 #define DEBUG_PRINT3(x1, x2, x3)
795 #define DEBUG_PRINT4(x1, x2, x3, x4)
796 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
797 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
799 #endif /* not DEBUG */
801 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
802 also be assigned to arbitrarily: each pattern buffer stores its own
803 syntax, so it can be changed between regex compilations. */
804 reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS;
807 /* Specify the precise syntax of regexps for compilation. This provides
808 for compatibility for various utilities which historically have
809 different, incompatible syntaxes.
811 The argument SYNTAX is a bit mask comprised of the various bits
812 defined in regex.h. We return the old syntax. */
815 re_set_syntax (syntax)
818 reg_syntax_t ret = re_syntax_options;
820 re_syntax_options = syntax;
824 /* This table gives an error message for each of the error codes listed
825 in regex.h. Obviously the order here has to be same as there. */
827 static const char *re_error_msg[] =
828 { NULL, /* REG_NOERROR */
829 "No match", /* REG_NOMATCH */
830 "Invalid regular expression", /* REG_BADPAT */
831 "Invalid collation character", /* REG_ECOLLATE */
832 "Invalid character class name", /* REG_ECTYPE */
833 "Trailing backslash", /* REG_EESCAPE */
834 "Invalid back reference", /* REG_ESUBREG */
835 "Unmatched [ or [^", /* REG_EBRACK */
836 "Unmatched ( or \\(", /* REG_EPAREN */
837 "Unmatched \\{", /* REG_EBRACE */
838 "Invalid content of \\{\\}", /* REG_BADBR */
839 "Invalid range end", /* REG_ERANGE */
840 "Memory exhausted", /* REG_ESPACE */
841 "Invalid preceding regular expression", /* REG_BADRPT */
842 "Premature end of regular expression", /* REG_EEND */
843 "Regular expression too big", /* REG_ESIZE */
844 "Unmatched ) or \\)", /* REG_ERPAREN */
847 /* Subroutine declarations and macros for regex_compile. */
849 static void store_op1 (), store_op2 ();
850 static void insert_op1 (), insert_op2 ();
851 static boolean at_begline_loc_p (), at_endline_loc_p ();
852 static boolean group_in_compile_stack ();
853 static reg_errcode_t compile_range ();
855 /* Fetch the next character in the uncompiled pattern---translating it
856 if necessary. Also cast from a signed character in the constant
857 string passed to us by the user to an unsigned char that we can use
858 as an array index (in, e.g., `translate'). */
859 #define PATFETCH(c) \
860 do {if (p == pend) return REG_EEND; \
861 c = (unsigned char) *p++; \
862 if (translate) c = translate[c]; \
865 /* Fetch the next character in the uncompiled pattern, with no
867 #define PATFETCH_RAW(c) \
868 do {if (p == pend) return REG_EEND; \
869 c = (unsigned char) *p++; \
872 /* Go backwards one character in the pattern. */
873 #define PATUNFETCH p--
876 /* If `translate' is non-null, return translate[D], else just D. We
877 cast the subscript to translate because some data is declared as
878 `char *', to avoid warnings when a string constant is passed. But
879 when we use a character as a subscript we must make it unsigned. */
880 #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
883 /* Macros for outputting the compiled pattern into `buffer'. */
885 /* If the buffer isn't allocated when it comes in, use this. */
886 #define INIT_BUF_SIZE 32
888 /* Make sure we have at least N more bytes of space in buffer. */
889 #define GET_BUFFER_SPACE(n) \
890 while (b - bufp->buffer + (n) > bufp->allocated) \
893 /* Make sure we have one more byte of buffer space and then add C to it. */
894 #define BUF_PUSH(c) \
896 GET_BUFFER_SPACE (1); \
897 *b++ = (unsigned char) (c); \
901 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
902 #define BUF_PUSH_2(c1, c2) \
904 GET_BUFFER_SPACE (2); \
905 *b++ = (unsigned char) (c1); \
906 *b++ = (unsigned char) (c2); \
910 /* As with BUF_PUSH_2, except for three bytes. */
911 #define BUF_PUSH_3(c1, c2, c3) \
913 GET_BUFFER_SPACE (3); \
914 *b++ = (unsigned char) (c1); \
915 *b++ = (unsigned char) (c2); \
916 *b++ = (unsigned char) (c3); \
920 /* Store a jump with opcode OP at LOC to location TO. We store a
921 relative address offset by the three bytes the jump itself occupies. */
922 #define STORE_JUMP(op, loc, to) \
923 store_op1 (op, loc, (to) - (loc) - 3)
925 /* Likewise, for a two-argument jump. */
926 #define STORE_JUMP2(op, loc, to, arg) \
927 store_op2 (op, loc, (to) - (loc) - 3, arg)
929 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
930 #define INSERT_JUMP(op, loc, to) \
931 insert_op1 (op, loc, (to) - (loc) - 3, b)
933 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
934 #define INSERT_JUMP2(op, loc, to, arg) \
935 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
938 /* This is not an arbitrary limit: the arguments which represent offsets
939 into the pattern are two bytes long. So if 2^16 bytes turns out to
940 be too small, many things would have to change. */
941 #define MAX_BUF_SIZE (1L << 16)
944 /* Extend the buffer by twice its current size via realloc and
945 reset the pointers that pointed into the old block to point to the
946 correct places in the new one. If extending the buffer results in it
947 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
948 #define EXTEND_BUFFER() \
950 unsigned char *old_buffer = bufp->buffer; \
951 if (bufp->allocated == MAX_BUF_SIZE) \
953 bufp->allocated <<= 1; \
954 if (bufp->allocated > MAX_BUF_SIZE) \
955 bufp->allocated = MAX_BUF_SIZE; \
956 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
957 if (bufp->buffer == NULL) \
959 /* If the buffer moved, move all the pointers into it. */ \
960 if (old_buffer != bufp->buffer) \
962 b = (b - old_buffer) + bufp->buffer; \
963 begalt = (begalt - old_buffer) + bufp->buffer; \
964 if (fixup_alt_jump) \
965 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
967 laststart = (laststart - old_buffer) + bufp->buffer; \
969 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
974 /* Since we have one byte reserved for the register number argument to
975 {start,stop}_memory, the maximum number of groups we can report
976 things about is what fits in that byte. */
977 #define MAX_REGNUM 255
979 /* But patterns can have more than `MAX_REGNUM' registers. We just
980 ignore the excess. */
981 typedef unsigned regnum_t;
984 /* Macros for the compile stack. */
986 /* Since offsets can go either forwards or backwards, this type needs to
987 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
988 typedef int pattern_offset_t;
992 pattern_offset_t begalt_offset;
993 pattern_offset_t fixup_alt_jump;
994 pattern_offset_t inner_group_offset;
995 pattern_offset_t laststart_offset;
997 } compile_stack_elt_t;
1002 compile_stack_elt_t *stack;
1004 unsigned avail; /* Offset of next open position. */
1005 } compile_stack_type;
1008 #define INIT_COMPILE_STACK_SIZE 32
1010 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1011 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1013 /* The next available element. */
1014 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1017 /* Set the bit for character C in a list. */
1018 #define SET_LIST_BIT(c) \
1019 (b[((unsigned char) (c)) / BYTEWIDTH] \
1020 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1023 /* Get the next unsigned number in the uncompiled pattern. */
1024 #define GET_UNSIGNED_NUMBER(num) \
1028 while (ISDIGIT (c)) \
1032 num = num * 10 + c - '0'; \
1040 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1042 #define IS_CHAR_CLASS(string) \
1043 (STREQ (string, "alpha") || STREQ (string, "upper") \
1044 || STREQ (string, "lower") || STREQ (string, "digit") \
1045 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1046 || STREQ (string, "space") || STREQ (string, "print") \
1047 || STREQ (string, "punct") || STREQ (string, "graph") \
1048 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1050 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1051 Returns one of error codes defined in `regex.h', or zero for success.
1053 Assumes the `allocated' (and perhaps `buffer') and `translate'
1054 fields are set in BUFP on entry.
1056 If it succeeds, results are put in BUFP (if it returns an error, the
1057 contents of BUFP are undefined):
1058 `buffer' is the compiled pattern;
1059 `syntax' is set to SYNTAX;
1060 `used' is set to the length of the compiled pattern;
1061 `fastmap_accurate' is zero;
1062 `re_nsub' is the number of subexpressions in PATTERN;
1063 `not_bol' and `not_eol' are zero;
1065 The `fastmap' and `newline_anchor' fields are neither
1066 examined nor set. */
1068 static reg_errcode_t
1069 regex_compile (pattern, size, syntax, bufp)
1070 const char *pattern;
1072 reg_syntax_t syntax;
1073 struct re_pattern_buffer *bufp;
1075 /* We fetch characters from PATTERN here. Even though PATTERN is
1076 `char *' (i.e., signed), we declare these variables as unsigned, so
1077 they can be reliably used as array indices. */
1078 register unsigned char c, c1;
1080 /* A random tempory spot in PATTERN. */
1083 /* Points to the end of the buffer, where we should append. */
1084 register unsigned char *b;
1086 /* Keeps track of unclosed groups. */
1087 compile_stack_type compile_stack;
1089 /* Points to the current (ending) position in the pattern. */
1090 const char *p = pattern;
1091 const char *pend = pattern + size;
1093 /* How to translate the characters in the pattern. */
1094 char *translate = bufp->translate;
1096 /* Address of the count-byte of the most recently inserted `exactn'
1097 command. This makes it possible to tell if a new exact-match
1098 character can be added to that command or if the character requires
1099 a new `exactn' command. */
1100 unsigned char *pending_exact = 0;
1102 /* Address of start of the most recently finished expression.
1103 This tells, e.g., postfix * where to find the start of its
1104 operand. Reset at the beginning of groups and alternatives. */
1105 unsigned char *laststart = 0;
1107 /* Address of beginning of regexp, or inside of last group. */
1108 unsigned char *begalt;
1110 /* Place in the uncompiled pattern (i.e., the {) to
1111 which to go back if the interval is invalid. */
1112 const char *beg_interval;
1114 /* Address of the place where a forward jump should go to the end of
1115 the containing expression. Each alternative of an `or' -- except the
1116 last -- ends with a forward jump of this sort. */
1117 unsigned char *fixup_alt_jump = 0;
1119 /* Counts open-groups as they are encountered. Remembered for the
1120 matching close-group on the compile stack, so the same register
1121 number is put in the stop_memory as the start_memory. */
1122 regnum_t regnum = 0;
1125 DEBUG_PRINT1 ("\nCompiling pattern: ");
1128 unsigned debug_count;
1130 for (debug_count = 0; debug_count < size; debug_count++)
1131 printchar (pattern[debug_count]);
1136 /* Initialize the compile stack. */
1137 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1138 if (compile_stack.stack == NULL)
1141 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1142 compile_stack.avail = 0;
1144 /* Initialize the pattern buffer. */
1145 bufp->syntax = syntax;
1146 bufp->fastmap_accurate = 0;
1147 bufp->not_bol = bufp->not_eol = 0;
1149 /* Set `used' to zero, so that if we return an error, the pattern
1150 printer (for debugging) will think there's no pattern. We reset it
1154 /* Always count groups, whether or not bufp->no_sub is set. */
1157 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1158 /* Initialize the syntax table. */
1159 init_syntax_once ();
1162 if (bufp->allocated == 0)
1165 { /* If zero allocated, but buffer is non-null, try to realloc
1166 enough space. This loses if buffer's address is bogus, but
1167 that is the user's responsibility. */
1168 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1171 { /* Caller did not allocate a buffer. Do it for them. */
1172 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1174 if (!bufp->buffer) return REG_ESPACE;
1176 bufp->allocated = INIT_BUF_SIZE;
1179 begalt = b = bufp->buffer;
1181 /* Loop through the uncompiled pattern until we're at the end. */
1190 if ( /* If at start of pattern, it's an operator. */
1192 /* If context independent, it's an operator. */
1193 || syntax & RE_CONTEXT_INDEP_ANCHORS
1194 /* Otherwise, depends on what's come before. */
1195 || at_begline_loc_p (pattern, p, syntax))
1205 if ( /* If at end of pattern, it's an operator. */
1207 /* If context independent, it's an operator. */
1208 || syntax & RE_CONTEXT_INDEP_ANCHORS
1209 /* Otherwise, depends on what's next. */
1210 || at_endline_loc_p (p, pend, syntax))
1220 if ((syntax & RE_BK_PLUS_QM)
1221 || (syntax & RE_LIMITED_OPS))
1225 /* If there is no previous pattern... */
1228 if (syntax & RE_CONTEXT_INVALID_OPS)
1230 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1235 /* Are we optimizing this jump? */
1236 boolean keep_string_p = false;
1238 /* 1 means zero (many) matches is allowed. */
1239 char zero_times_ok = 0, many_times_ok = 0;
1241 /* If there is a sequence of repetition chars, collapse it
1242 down to just one (the right one). We can't combine
1243 interval operators with these because of, e.g., `a{2}*',
1244 which should only match an even number of `a's. */
1248 zero_times_ok |= c != '+';
1249 many_times_ok |= c != '?';
1257 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1260 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1262 if (p == pend) return REG_EESCAPE;
1265 if (!(c1 == '+' || c1 == '?'))
1280 /* If we get here, we found another repeat character. */
1283 /* Star, etc. applied to an empty pattern is equivalent
1284 to an empty pattern. */
1288 /* Now we know whether or not zero matches is allowed
1289 and also whether or not two or more matches is allowed. */
1291 { /* More than one repetition is allowed, so put in at the
1292 end a backward relative jump from `b' to before the next
1293 jump we're going to put in below (which jumps from
1294 laststart to after this jump).
1296 But if we are at the `*' in the exact sequence `.*\n',
1297 insert an unconditional jump backwards to the .,
1298 instead of the beginning of the loop. This way we only
1299 push a failure point once, instead of every time
1300 through the loop. */
1301 assert (p - 1 > pattern);
1303 /* Allocate the space for the jump. */
1304 GET_BUFFER_SPACE (3);
1306 /* We know we are not at the first character of the pattern,
1307 because laststart was nonzero. And we've already
1308 incremented `p', by the way, to be the character after
1309 the `*'. Do we have to do something analogous here
1310 for null bytes, because of RE_DOT_NOT_NULL? */
1311 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1313 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1314 && !(syntax & RE_DOT_NEWLINE))
1315 { /* We have .*\n. */
1316 STORE_JUMP (jump, b, laststart);
1317 keep_string_p = true;
1320 /* Anything else. */
1321 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1323 /* We've added more stuff to the buffer. */
1327 /* On failure, jump from laststart to b + 3, which will be the
1328 end of the buffer after this jump is inserted. */
1329 GET_BUFFER_SPACE (3);
1330 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1338 /* At least one repetition is required, so insert a
1339 `dummy_failure_jump' before the initial
1340 `on_failure_jump' instruction of the loop. This
1341 effects a skip over that instruction the first time
1342 we hit that loop. */
1343 GET_BUFFER_SPACE (3);
1344 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1359 boolean had_char_class = false;
1361 if (p == pend) return REG_EBRACK;
1363 /* Ensure that we have enough space to push a charset: the
1364 opcode, the length count, and the bitset; 34 bytes in all. */
1365 GET_BUFFER_SPACE (34);
1369 /* We test `*p == '^' twice, instead of using an if
1370 statement, so we only need one BUF_PUSH. */
1371 BUF_PUSH (*p == '^' ? charset_not : charset);
1375 /* Remember the first position in the bracket expression. */
1378 /* Push the number of bytes in the bitmap. */
1379 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1381 /* Clear the whole map. */
1382 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1384 /* charset_not matches newline according to a syntax bit. */
1385 if ((re_opcode_t) b[-2] == charset_not
1386 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1387 SET_LIST_BIT ('\n');
1389 /* Read in characters and ranges, setting map bits. */
1392 if (p == pend) return REG_EBRACK;
1396 /* \ might escape characters inside [...] and [^...]. */
1397 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1399 if (p == pend) return REG_EESCAPE;
1406 /* Could be the end of the bracket expression. If it's
1407 not (i.e., when the bracket expression is `[]' so
1408 far), the ']' character bit gets set way below. */
1409 if (c == ']' && p != p1 + 1)
1412 /* Look ahead to see if it's a range when the last thing
1413 was a character class. */
1414 if (had_char_class && c == '-' && *p != ']')
1417 /* Look ahead to see if it's a range when the last thing
1418 was a character: if this is a hyphen not at the
1419 beginning or the end of a list, then it's the range
1422 && !(p - 2 >= pattern && p[-2] == '[')
1423 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1427 = compile_range (&p, pend, translate, syntax, b);
1428 if (ret != REG_NOERROR) return ret;
1431 else if (p[0] == '-' && p[1] != ']')
1432 { /* This handles ranges made up of characters only. */
1435 /* Move past the `-'. */
1438 ret = compile_range (&p, pend, translate, syntax, b);
1439 if (ret != REG_NOERROR) return ret;
1442 /* See if we're at the beginning of a possible character
1445 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1446 { /* Leave room for the null. */
1447 char str[CHAR_CLASS_MAX_LENGTH + 1];
1452 /* If pattern is `[[:'. */
1453 if (p == pend) return REG_EBRACK;
1458 if (c == ':' || c == ']' || p == pend
1459 || c1 == CHAR_CLASS_MAX_LENGTH)
1465 /* If isn't a word bracketed by `[:' and:`]':
1466 undo the ending character, the letters, and leave
1467 the leading `:' and `[' (but set bits for them). */
1468 if (c == ':' && *p == ']')
1471 boolean is_alnum = STREQ (str, "alnum");
1472 boolean is_alpha = STREQ (str, "alpha");
1473 boolean is_blank = STREQ (str, "blank");
1474 boolean is_cntrl = STREQ (str, "cntrl");
1475 boolean is_digit = STREQ (str, "digit");
1476 boolean is_graph = STREQ (str, "graph");
1477 boolean is_lower = STREQ (str, "lower");
1478 boolean is_print = STREQ (str, "print");
1479 boolean is_punct = STREQ (str, "punct");
1480 boolean is_space = STREQ (str, "space");
1481 boolean is_upper = STREQ (str, "upper");
1482 boolean is_xdigit = STREQ (str, "xdigit");
1484 if (!IS_CHAR_CLASS (str)) return REG_ECTYPE;
1486 /* Throw away the ] at the end of the character
1490 if (p == pend) return REG_EBRACK;
1492 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
1494 if ( (is_alnum && ISALNUM (ch))
1495 || (is_alpha && ISALPHA (ch))
1496 || (is_blank && ISBLANK (ch))
1497 || (is_cntrl && ISCNTRL (ch))
1498 || (is_digit && ISDIGIT (ch))
1499 || (is_graph && ISGRAPH (ch))
1500 || (is_lower && ISLOWER (ch))
1501 || (is_print && ISPRINT (ch))
1502 || (is_punct && ISPUNCT (ch))
1503 || (is_space && ISSPACE (ch))
1504 || (is_upper && ISUPPER (ch))
1505 || (is_xdigit && ISXDIGIT (ch)))
1508 had_char_class = true;
1517 had_char_class = false;
1522 had_char_class = false;
1527 /* Discard any (non)matching list bytes that are all 0 at the
1528 end of the map. Decrease the map-length byte too. */
1529 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
1537 if (syntax & RE_NO_BK_PARENS)
1544 if (syntax & RE_NO_BK_PARENS)
1551 if (syntax & RE_NEWLINE_ALT)
1558 if (syntax & RE_NO_BK_VBAR)
1565 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
1566 goto handle_interval;
1572 if (p == pend) return REG_EESCAPE;
1574 /* Do not translate the character after the \, so that we can
1575 distinguish, e.g., \B from \b, even if we normally would
1576 translate, e.g., B to b. */
1582 if (syntax & RE_NO_BK_PARENS)
1583 goto normal_backslash;
1589 if (COMPILE_STACK_FULL)
1591 RETALLOC (compile_stack.stack, compile_stack.size << 1,
1592 compile_stack_elt_t);
1593 if (compile_stack.stack == NULL) return REG_ESPACE;
1595 compile_stack.size <<= 1;
1598 /* These are the values to restore when we hit end of this
1599 group. They are all relative offsets, so that if the
1600 whole pattern moves because of realloc, they will still
1602 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
1603 COMPILE_STACK_TOP.fixup_alt_jump
1604 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
1605 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
1606 COMPILE_STACK_TOP.regnum = regnum;
1608 /* We will eventually replace the 0 with the number of
1609 groups inner to this one. But do not push a
1610 start_memory for groups beyond the last one we can
1611 represent in the compiled pattern. */
1612 if (regnum <= MAX_REGNUM)
1614 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
1615 BUF_PUSH_3 (start_memory, regnum, 0);
1618 compile_stack.avail++;
1623 /* If we've reached MAX_REGNUM groups, then this open
1624 won't actually generate any code, so we'll have to
1625 clear pending_exact explicitly. */
1631 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
1633 if (COMPILE_STACK_EMPTY)
1635 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1636 goto normal_backslash;
1643 { /* Push a dummy failure point at the end of the
1644 alternative for a possible future
1645 `pop_failure_jump' to pop. See comments at
1646 `push_dummy_failure' in `re_match_2'. */
1647 BUF_PUSH (push_dummy_failure);
1649 /* We allocated space for this jump when we assigned
1650 to `fixup_alt_jump', in the `handle_alt' case below. */
1651 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
1654 /* See similar code for backslashed left paren above. */
1655 if (COMPILE_STACK_EMPTY)
1657 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1663 /* Since we just checked for an empty stack above, this
1664 ``can't happen''. */
1665 assert (compile_stack.avail != 0);
1667 /* We don't just want to restore into `regnum', because
1668 later groups should continue to be numbered higher,
1669 as in `(ab)c(de)' -- the second group is #2. */
1670 regnum_t this_group_regnum;
1672 compile_stack.avail--;
1673 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
1675 = COMPILE_STACK_TOP.fixup_alt_jump
1676 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
1678 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
1679 this_group_regnum = COMPILE_STACK_TOP.regnum;
1680 /* If we've reached MAX_REGNUM groups, then this open
1681 won't actually generate any code, so we'll have to
1682 clear pending_exact explicitly. */
1685 /* We're at the end of the group, so now we know how many
1686 groups were inside this one. */
1687 if (this_group_regnum <= MAX_REGNUM)
1689 unsigned char *inner_group_loc
1690 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
1692 *inner_group_loc = regnum - this_group_regnum;
1693 BUF_PUSH_3 (stop_memory, this_group_regnum,
1694 regnum - this_group_regnum);
1700 case '|': /* `\|'. */
1701 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
1702 goto normal_backslash;
1704 if (syntax & RE_LIMITED_OPS)
1707 /* Insert before the previous alternative a jump which
1708 jumps to this alternative if the former fails. */
1709 GET_BUFFER_SPACE (3);
1710 INSERT_JUMP (on_failure_jump, begalt, b + 6);
1714 /* The alternative before this one has a jump after it
1715 which gets executed if it gets matched. Adjust that
1716 jump so it will jump to this alternative's analogous
1717 jump (put in below, which in turn will jump to the next
1718 (if any) alternative's such jump, etc.). The last such
1719 jump jumps to the correct final destination. A picture:
1725 If we are at `b', then fixup_alt_jump right now points to a
1726 three-byte space after `a'. We'll put in the jump, set
1727 fixup_alt_jump to right after `b', and leave behind three
1728 bytes which we'll fill in when we get to after `c'. */
1731 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
1733 /* Mark and leave space for a jump after this alternative,
1734 to be filled in later either by next alternative or
1735 when know we're at the end of a series of alternatives. */
1737 GET_BUFFER_SPACE (3);
1746 /* If \{ is a literal. */
1747 if (!(syntax & RE_INTERVALS)
1748 /* If we're at `\{' and it's not the open-interval
1750 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
1751 || (p - 2 == pattern && p == pend))
1752 goto normal_backslash;
1756 /* If got here, then the syntax allows intervals. */
1758 /* At least (most) this many matches must be made. */
1759 int lower_bound = -1, upper_bound = -1;
1761 beg_interval = p - 1;
1765 if (syntax & RE_NO_BK_BRACES)
1766 goto unfetch_interval;
1771 GET_UNSIGNED_NUMBER (lower_bound);
1775 GET_UNSIGNED_NUMBER (upper_bound);
1776 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
1779 /* Interval such as `{1}' => match exactly once. */
1780 upper_bound = lower_bound;
1782 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
1783 || lower_bound > upper_bound)
1785 if (syntax & RE_NO_BK_BRACES)
1786 goto unfetch_interval;
1791 if (!(syntax & RE_NO_BK_BRACES))
1793 if (c != '\\') return REG_EBRACE;
1800 if (syntax & RE_NO_BK_BRACES)
1801 goto unfetch_interval;
1806 /* We just parsed a valid interval. */
1808 /* If it's invalid to have no preceding re. */
1811 if (syntax & RE_CONTEXT_INVALID_OPS)
1813 else if (syntax & RE_CONTEXT_INDEP_OPS)
1816 goto unfetch_interval;
1819 /* If the upper bound is zero, don't want to succeed at
1820 all; jump from `laststart' to `b + 3', which will be
1821 the end of the buffer after we insert the jump. */
1822 if (upper_bound == 0)
1824 GET_BUFFER_SPACE (3);
1825 INSERT_JUMP (jump, laststart, b + 3);
1829 /* Otherwise, we have a nontrivial interval. When
1830 we're all done, the pattern will look like:
1831 set_number_at <jump count> <upper bound>
1832 set_number_at <succeed_n count> <lower bound>
1833 succeed_n <after jump addr> <succed_n count>
1835 jump_n <succeed_n addr> <jump count>
1836 (The upper bound and `jump_n' are omitted if
1837 `upper_bound' is 1, though.) */
1839 { /* If the upper bound is > 1, we need to insert
1840 more at the end of the loop. */
1841 unsigned nbytes = 10 + (upper_bound > 1) * 10;
1843 GET_BUFFER_SPACE (nbytes);
1845 /* Initialize lower bound of the `succeed_n', even
1846 though it will be set during matching by its
1847 attendant `set_number_at' (inserted next),
1848 because `re_compile_fastmap' needs to know.
1849 Jump to the `jump_n' we might insert below. */
1850 INSERT_JUMP2 (succeed_n, laststart,
1851 b + 5 + (upper_bound > 1) * 5,
1855 /* Code to initialize the lower bound. Insert
1856 before the `succeed_n'. The `5' is the last two
1857 bytes of this `set_number_at', plus 3 bytes of
1858 the following `succeed_n'. */
1859 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
1862 if (upper_bound > 1)
1863 { /* More than one repetition is allowed, so
1864 append a backward jump to the `succeed_n'
1865 that starts this interval.
1867 When we've reached this during matching,
1868 we'll have matched the interval once, so
1869 jump back only `upper_bound - 1' times. */
1870 STORE_JUMP2 (jump_n, b, laststart + 5,
1874 /* The location we want to set is the second
1875 parameter of the `jump_n'; that is `b-2' as
1876 an absolute address. `laststart' will be
1877 the `set_number_at' we're about to insert;
1878 `laststart+3' the number to set, the source
1879 for the relative address. But we are
1880 inserting into the middle of the pattern --
1881 so everything is getting moved up by 5.
1882 Conclusion: (b - 2) - (laststart + 3) + 5,
1883 i.e., b - laststart.
1885 We insert this at the beginning of the loop
1886 so that if we fail during matching, we'll
1887 reinitialize the bounds. */
1888 insert_op2 (set_number_at, laststart, b - laststart,
1889 upper_bound - 1, b);
1894 beg_interval = NULL;
1899 /* If an invalid interval, match the characters as literals. */
1900 assert (beg_interval);
1902 beg_interval = NULL;
1904 /* normal_char and normal_backslash need `c'. */
1907 if (!(syntax & RE_NO_BK_BRACES))
1909 if (p > pattern && p[-1] == '\\')
1910 goto normal_backslash;
1915 /* There is no way to specify the before_dot and after_dot
1916 operators. rms says this is ok. --karl */
1924 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
1930 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
1937 BUF_PUSH (wordchar);
1943 BUF_PUSH (notwordchar);
1956 BUF_PUSH (wordbound);
1960 BUF_PUSH (notwordbound);
1971 case '1': case '2': case '3': case '4': case '5':
1972 case '6': case '7': case '8': case '9':
1973 if (syntax & RE_NO_BK_REFS)
1981 /* Can't back reference to a subexpression if inside of it. */
1982 if (group_in_compile_stack (compile_stack, c1))
1986 BUF_PUSH_2 (duplicate, c1);
1992 if (syntax & RE_BK_PLUS_QM)
1995 goto normal_backslash;
1999 /* You might think it would be useful for \ to mean
2000 not to translate; but if we don't translate it
2001 it will never match anything. */
2009 /* Expects the character in `c'. */
2011 /* If no exactn currently being built. */
2014 /* If last exactn not at current position. */
2015 || pending_exact + *pending_exact + 1 != b
2017 /* We have only one byte following the exactn for the count. */
2018 || *pending_exact == (1 << BYTEWIDTH) - 1
2020 /* If followed by a repetition operator. */
2021 || *p == '*' || *p == '^'
2022 || ((syntax & RE_BK_PLUS_QM)
2023 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2024 : (*p == '+' || *p == '?'))
2025 || ((syntax & RE_INTERVALS)
2026 && ((syntax & RE_NO_BK_BRACES)
2028 : (p[0] == '\\' && p[1] == '{'))))
2030 /* Start building a new exactn. */
2034 BUF_PUSH_2 (exactn, 0);
2035 pending_exact = b - 1;
2042 } /* while p != pend */
2045 /* Through the pattern now. */
2048 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2050 if (!COMPILE_STACK_EMPTY)
2053 free (compile_stack.stack);
2055 /* We have succeeded; set the length of the buffer. */
2056 bufp->used = b - bufp->buffer;
2061 DEBUG_PRINT1 ("\nCompiled pattern: ");
2062 print_compiled_pattern (bufp);
2067 } /* regex_compile */
2069 /* Subroutines for `regex_compile'. */
2071 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2074 store_op1 (op, loc, arg)
2079 *loc = (unsigned char) op;
2080 STORE_NUMBER (loc + 1, arg);
2084 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2087 store_op2 (op, loc, arg1, arg2)
2092 *loc = (unsigned char) op;
2093 STORE_NUMBER (loc + 1, arg1);
2094 STORE_NUMBER (loc + 3, arg2);
2098 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2099 for OP followed by two-byte integer parameter ARG. */
2102 insert_op1 (op, loc, arg, end)
2108 register unsigned char *pfrom = end;
2109 register unsigned char *pto = end + 3;
2111 while (pfrom != loc)
2114 store_op1 (op, loc, arg);
2118 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2121 insert_op2 (op, loc, arg1, arg2, end)
2127 register unsigned char *pfrom = end;
2128 register unsigned char *pto = end + 5;
2130 while (pfrom != loc)
2133 store_op2 (op, loc, arg1, arg2);
2137 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2138 after an alternative or a begin-subexpression. We assume there is at
2139 least one character before the ^. */
2142 at_begline_loc_p (pattern, p, syntax)
2143 const char *pattern, *p;
2144 reg_syntax_t syntax;
2146 const char *prev = p - 2;
2147 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2150 /* After a subexpression? */
2151 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2152 /* After an alternative? */
2153 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2157 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2158 at least one character after the $, i.e., `P < PEND'. */
2161 at_endline_loc_p (p, pend, syntax)
2162 const char *p, *pend;
2165 const char *next = p;
2166 boolean next_backslash = *next == '\\';
2167 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2170 /* Before a subexpression? */
2171 (syntax & RE_NO_BK_PARENS ? *next == ')'
2172 : next_backslash && next_next && *next_next == ')')
2173 /* Before an alternative? */
2174 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2175 : next_backslash && next_next && *next_next == '|');
2179 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2180 false if it's not. */
2183 group_in_compile_stack (compile_stack, regnum)
2184 compile_stack_type compile_stack;
2189 for (this_element = compile_stack.avail - 1;
2192 if (compile_stack.stack[this_element].regnum == regnum)
2199 /* Read the ending character of a range (in a bracket expression) from the
2200 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2201 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2202 Then we set the translation of all bits between the starting and
2203 ending characters (inclusive) in the compiled pattern B.
2205 Return an error code.
2207 We use these short variable names so we can use the same macros as
2208 `regex_compile' itself. */
2210 static reg_errcode_t
2211 compile_range (p_ptr, pend, translate, syntax, b)
2212 const char **p_ptr, *pend;
2214 reg_syntax_t syntax;
2219 const char *p = *p_ptr;
2220 int range_start, range_end;
2225 /* Even though the pattern is a signed `char *', we need to fetch
2226 with unsigned char *'s; if the high bit of the pattern character
2227 is set, the range endpoints will be negative if we fetch using a
2230 We also want to fetch the endpoints without translating them; the
2231 appropriate translation is done in the bit-setting loop below. */
2232 range_start = ((unsigned char *) p)[-2];
2233 range_end = ((unsigned char *) p)[0];
2235 /* Have to increment the pointer into the pattern string, so the
2236 caller isn't still at the ending character. */
2239 /* If the start is after the end, the range is empty. */
2240 if (range_start > range_end)
2241 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2243 /* Here we see why `this_char' has to be larger than an `unsigned
2244 char' -- the range is inclusive, so if `range_end' == 0xff
2245 (assuming 8-bit characters), we would otherwise go into an infinite
2246 loop, since all characters <= 0xff. */
2247 for (this_char = range_start; this_char <= range_end; this_char++)
2249 SET_LIST_BIT (TRANSLATE (this_char));
2255 /* Failure stack declarations and macros; both re_compile_fastmap and
2256 re_match_2 use a failure stack. These have to be macros because of
2260 /* Number of failure points for which to initially allocate space
2261 when matching. If this number is exceeded, we allocate more
2262 space, so it is not a hard limit. */
2263 #ifndef INIT_FAILURE_ALLOC
2264 #define INIT_FAILURE_ALLOC 5
2267 /* Roughly the maximum number of failure points on the stack. Would be
2268 exactly that if always used MAX_FAILURE_SPACE each time we failed.
2269 This is a variable only so users of regex can assign to it; we never
2270 change it ourselves. */
2271 int re_max_failures = 2000;
2273 typedef const unsigned char *fail_stack_elt_t;
2277 fail_stack_elt_t *stack;
2279 unsigned avail; /* Offset of next open position. */
2282 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
2283 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
2284 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
2285 #define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail])
2288 /* Initialize `fail_stack'. Do `return -2' if the alloc fails. */
2290 #define INIT_FAIL_STACK() \
2292 fail_stack.stack = (fail_stack_elt_t *) \
2293 REGEX_ALLOCATE (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
2295 if (fail_stack.stack == NULL) \
2298 fail_stack.size = INIT_FAILURE_ALLOC; \
2299 fail_stack.avail = 0; \
2303 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
2305 Return 1 if succeeds, and 0 if either ran out of memory
2306 allocating space for it or it was already too large.
2308 REGEX_REALLOCATE requires `destination' be declared. */
2310 #define DOUBLE_FAIL_STACK(fail_stack) \
2311 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
2313 : ((fail_stack).stack = (fail_stack_elt_t *) \
2314 REGEX_REALLOCATE ((fail_stack).stack, \
2315 (fail_stack).size * sizeof (fail_stack_elt_t), \
2316 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
2318 (fail_stack).stack == NULL \
2320 : ((fail_stack).size <<= 1, \
2324 /* Push PATTERN_OP on FAIL_STACK.
2326 Return 1 if was able to do so and 0 if ran out of memory allocating
2328 #define PUSH_PATTERN_OP(pattern_op, fail_stack) \
2329 ((FAIL_STACK_FULL () \
2330 && !DOUBLE_FAIL_STACK (fail_stack)) \
2332 : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \
2335 /* This pushes an item onto the failure stack. Must be a four-byte
2336 value. Assumes the variable `fail_stack'. Probably should only
2337 be called from within `PUSH_FAILURE_POINT'. */
2338 #define PUSH_FAILURE_ITEM(item) \
2339 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) item
2341 /* The complement operation. Assumes `fail_stack' is nonempty. */
2342 #define POP_FAILURE_ITEM() fail_stack.stack[--fail_stack.avail]
2344 /* Used to omit pushing failure point id's when we're not debugging. */
2346 #define DEBUG_PUSH PUSH_FAILURE_ITEM
2347 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_ITEM ()
2349 #define DEBUG_PUSH(item)
2350 #define DEBUG_POP(item_addr)
2354 /* Push the information about the state we will need
2355 if we ever fail back to it.
2357 Requires variables fail_stack, regstart, regend, reg_info, and
2358 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
2361 Does `return FAILURE_CODE' if runs out of memory. */
2363 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
2365 char *destination; \
2366 /* Must be int, so when we don't save any registers, the arithmetic \
2367 of 0 + -1 isn't done as unsigned. */ \
2370 DEBUG_STATEMENT (failure_id++); \
2371 DEBUG_STATEMENT (nfailure_points_pushed++); \
2372 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
2373 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
2374 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
2376 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
2377 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
2379 /* Ensure we have enough space allocated for what we will push. */ \
2380 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
2382 if (!DOUBLE_FAIL_STACK (fail_stack)) \
2383 return failure_code; \
2385 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
2386 (fail_stack).size); \
2387 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
2390 /* Push the info, starting with the registers. */ \
2391 DEBUG_PRINT1 ("\n"); \
2393 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
2396 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
2397 DEBUG_STATEMENT (num_regs_pushed++); \
2399 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2400 PUSH_FAILURE_ITEM (regstart[this_reg]); \
2402 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2403 PUSH_FAILURE_ITEM (regend[this_reg]); \
2405 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
2406 DEBUG_PRINT2 (" match_null=%d", \
2407 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
2408 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
2409 DEBUG_PRINT2 (" matched_something=%d", \
2410 MATCHED_SOMETHING (reg_info[this_reg])); \
2411 DEBUG_PRINT2 (" ever_matched=%d", \
2412 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
2413 DEBUG_PRINT1 ("\n"); \
2414 PUSH_FAILURE_ITEM (reg_info[this_reg].word); \
2417 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
2418 PUSH_FAILURE_ITEM (lowest_active_reg); \
2420 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
2421 PUSH_FAILURE_ITEM (highest_active_reg); \
2423 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
2424 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
2425 PUSH_FAILURE_ITEM (pattern_place); \
2427 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
2428 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
2430 DEBUG_PRINT1 ("'\n"); \
2431 PUSH_FAILURE_ITEM (string_place); \
2433 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
2434 DEBUG_PUSH (failure_id); \
2437 /* This is the number of items that are pushed and popped on the stack
2438 for each register. */
2439 #define NUM_REG_ITEMS 3
2441 /* Individual items aside from the registers. */
2443 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
2445 #define NUM_NONREG_ITEMS 4
2448 /* We push at most this many items on the stack. */
2449 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
2451 /* We actually push this many items. */
2452 #define NUM_FAILURE_ITEMS \
2453 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
2456 /* How many items can still be added to the stack without overflowing it. */
2457 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
2460 /* Pops what PUSH_FAIL_STACK pushes.
2462 We restore into the parameters, all of which should be lvalues:
2463 STR -- the saved data position.
2464 PAT -- the saved pattern position.
2465 LOW_REG, HIGH_REG -- the highest and lowest active registers.
2466 REGSTART, REGEND -- arrays of string positions.
2467 REG_INFO -- array of information about each subexpression.
2469 Also assumes the variables `fail_stack' and (if debugging), `bufp',
2470 `pend', `string1', `size1', `string2', and `size2'. */
2472 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
2474 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
2476 const unsigned char *string_temp; \
2478 assert (!FAIL_STACK_EMPTY ()); \
2480 /* Remove failure points and point to how many regs pushed. */ \
2481 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
2482 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
2483 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
2485 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
2487 DEBUG_POP (&failure_id); \
2488 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
2490 /* If the saved string location is NULL, it came from an \
2491 on_failure_keep_string_jump opcode, and we want to throw away the \
2492 saved NULL, thus retaining our current position in the string. */ \
2493 string_temp = POP_FAILURE_ITEM (); \
2494 if (string_temp != NULL) \
2495 str = (const char *) string_temp; \
2497 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
2498 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
2499 DEBUG_PRINT1 ("'\n"); \
2501 pat = (unsigned char *) POP_FAILURE_ITEM (); \
2502 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
2503 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
2505 /* Restore register info. */ \
2506 high_reg = (unsigned) POP_FAILURE_ITEM (); \
2507 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
2509 low_reg = (unsigned) POP_FAILURE_ITEM (); \
2510 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
2512 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
2514 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
2516 reg_info[this_reg].word = POP_FAILURE_ITEM (); \
2517 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
2519 regend[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2520 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2522 regstart[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2523 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2526 DEBUG_STATEMENT (nfailure_points_popped++); \
2527 } /* POP_FAILURE_POINT */
2529 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2530 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2531 characters can start a string that matches the pattern. This fastmap
2532 is used by re_search to skip quickly over impossible starting points.
2534 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2535 area as BUFP->fastmap.
2537 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2540 Returns 0 if we succeed, -2 if an internal error. */
2543 re_compile_fastmap (bufp)
2544 struct re_pattern_buffer *bufp;
2547 fail_stack_type fail_stack;
2548 #ifndef REGEX_MALLOC
2551 /* We don't push any register information onto the failure stack. */
2552 unsigned num_regs = 0;
2554 register char *fastmap = bufp->fastmap;
2555 unsigned char *pattern = bufp->buffer;
2556 unsigned long size = bufp->used;
2557 const unsigned char *p = pattern;
2558 register unsigned char *pend = pattern + size;
2560 /* Assume that each path through the pattern can be null until
2561 proven otherwise. We set this false at the bottom of switch
2562 statement, to which we get only if a particular path doesn't
2563 match the empty string. */
2564 boolean path_can_be_null = true;
2566 /* We aren't doing a `succeed_n' to begin with. */
2567 boolean succeed_n_p = false;
2569 assert (fastmap != NULL && p != NULL);
2572 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2573 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2574 bufp->can_be_null = 0;
2576 while (p != pend || !FAIL_STACK_EMPTY ())
2580 bufp->can_be_null |= path_can_be_null;
2582 /* Reset for next path. */
2583 path_can_be_null = true;
2585 p = fail_stack.stack[--fail_stack.avail];
2588 /* We should never be about to go beyond the end of the pattern. */
2591 #ifdef SWITCH_ENUM_BUG
2592 switch ((int) ((re_opcode_t) *p++))
2594 switch ((re_opcode_t) *p++)
2598 /* I guess the idea here is to simply not bother with a fastmap
2599 if a backreference is used, since it's too hard to figure out
2600 the fastmap for the corresponding group. Setting
2601 `can_be_null' stops `re_search_2' from using the fastmap, so
2602 that is all we do. */
2604 bufp->can_be_null = 1;
2608 /* Following are the cases which match a character. These end
2617 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2618 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2624 /* Chars beyond end of map must be allowed. */
2625 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2628 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2629 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2635 for (j = 0; j < (1 << BYTEWIDTH); j++)
2636 if (SYNTAX (j) == Sword)
2642 for (j = 0; j < (1 << BYTEWIDTH); j++)
2643 if (SYNTAX (j) != Sword)
2649 /* `.' matches anything ... */
2650 for (j = 0; j < (1 << BYTEWIDTH); j++)
2653 /* ... except perhaps newline. */
2654 if (!(bufp->syntax & RE_DOT_NEWLINE))
2657 /* Return if we have already set `can_be_null'; if we have,
2658 then the fastmap is irrelevant. Something's wrong here. */
2659 else if (bufp->can_be_null)
2662 /* Otherwise, have to check alternative paths. */
2669 for (j = 0; j < (1 << BYTEWIDTH); j++)
2670 if (SYNTAX (j) == (enum syntaxcode) k)
2677 for (j = 0; j < (1 << BYTEWIDTH); j++)
2678 if (SYNTAX (j) != (enum syntaxcode) k)
2683 /* All cases after this match the empty string. These end with
2691 #endif /* not emacs */
2703 case push_dummy_failure:
2708 case pop_failure_jump:
2709 case maybe_pop_jump:
2712 case dummy_failure_jump:
2713 EXTRACT_NUMBER_AND_INCR (j, p);
2718 /* Jump backward implies we just went through the body of a
2719 loop and matched nothing. Opcode jumped to should be
2720 `on_failure_jump' or `succeed_n'. Just treat it like an
2721 ordinary jump. For a * loop, it has pushed its failure
2722 point already; if so, discard that as redundant. */
2723 if ((re_opcode_t) *p != on_failure_jump
2724 && (re_opcode_t) *p != succeed_n)
2728 EXTRACT_NUMBER_AND_INCR (j, p);
2731 /* If what's on the stack is where we are now, pop it. */
2732 if (!FAIL_STACK_EMPTY ()
2733 && fail_stack.stack[fail_stack.avail - 1] == p)
2739 case on_failure_jump:
2740 case on_failure_keep_string_jump:
2741 handle_on_failure_jump:
2742 EXTRACT_NUMBER_AND_INCR (j, p);
2744 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
2745 end of the pattern. We don't want to push such a point,
2746 since when we restore it above, entering the switch will
2747 increment `p' past the end of the pattern. We don't need
2748 to push such a point since we obviously won't find any more
2749 fastmap entries beyond `pend'. Such a pattern can match
2750 the null string, though. */
2753 if (!PUSH_PATTERN_OP (p + j, fail_stack))
2757 bufp->can_be_null = 1;
2761 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
2762 succeed_n_p = false;
2769 /* Get to the number of times to succeed. */
2772 /* Increment p past the n for when k != 0. */
2773 EXTRACT_NUMBER_AND_INCR (k, p);
2777 succeed_n_p = true; /* Spaghetti code alert. */
2778 goto handle_on_failure_jump;
2795 abort (); /* We have listed all the cases. */
2798 /* Getting here means we have found the possible starting
2799 characters for one path of the pattern -- and that the empty
2800 string does not match. We need not follow this path further.
2801 Instead, look at the next alternative (remembered on the
2802 stack), or quit if no more. The test at the top of the loop
2803 does these things. */
2804 path_can_be_null = false;
2808 /* Set `can_be_null' for the last path (also the first path, if the
2809 pattern is empty). */
2810 bufp->can_be_null |= path_can_be_null;
2812 } /* re_compile_fastmap */
2814 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
2815 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
2816 this memory for recording register information. STARTS and ENDS
2817 must be allocated using the malloc library routine, and must each
2818 be at least NUM_REGS * sizeof (regoff_t) bytes long.
2820 If NUM_REGS == 0, then subsequent matches should allocate their own
2823 Unless this function is called, the first search or match using
2824 PATTERN_BUFFER will allocate its own register data, without
2825 freeing the old data. */
2828 re_set_registers (bufp, regs, num_regs, starts, ends)
2829 struct re_pattern_buffer *bufp;
2830 struct re_registers *regs;
2832 regoff_t *starts, *ends;
2836 bufp->regs_allocated = REGS_REALLOCATE;
2837 regs->num_regs = num_regs;
2838 regs->start = starts;
2843 bufp->regs_allocated = REGS_UNALLOCATED;
2845 regs->start = regs->end = (regoff_t) 0;
2849 /* Searching routines. */
2851 /* Like re_search_2, below, but only one string is specified, and
2852 doesn't let you say where to stop matching. */
2855 re_search (bufp, string, size, startpos, range, regs)
2856 struct re_pattern_buffer *bufp;
2858 int size, startpos, range;
2859 struct re_registers *regs;
2861 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
2866 /* Using the compiled pattern in BUFP->buffer, first tries to match the
2867 virtual concatenation of STRING1 and STRING2, starting first at index
2868 STARTPOS, then at STARTPOS + 1, and so on.
2870 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
2872 RANGE is how far to scan while trying to match. RANGE = 0 means try
2873 only at STARTPOS; in general, the last start tried is STARTPOS +
2876 In REGS, return the indices of the virtual concatenation of STRING1
2877 and STRING2 that matched the entire BUFP->buffer and its contained
2880 Do not consider matching one past the index STOP in the virtual
2881 concatenation of STRING1 and STRING2.
2883 We return either the position in the strings at which the match was
2884 found, -1 if no match, or -2 if error (such as failure
2888 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
2889 struct re_pattern_buffer *bufp;
2890 const char *string1, *string2;
2894 struct re_registers *regs;
2898 register char *fastmap = bufp->fastmap;
2899 register char *translate = bufp->translate;
2900 int total_size = size1 + size2;
2901 int endpos = startpos + range;
2903 /* Check for out-of-range STARTPOS. */
2904 if (startpos < 0 || startpos > total_size)
2907 /* Fix up RANGE if it might eventually take us outside
2908 the virtual concatenation of STRING1 and STRING2. */
2910 range = -1 - startpos;
2911 else if (endpos > total_size)
2912 range = total_size - startpos;
2914 /* If the search isn't to be a backwards one, don't waste time in a
2915 search for a pattern that must be anchored. */
2916 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
2924 /* Update the fastmap now if not correct already. */
2925 if (fastmap && !bufp->fastmap_accurate)
2926 if (re_compile_fastmap (bufp) == -2)
2929 /* Loop through the string, looking for a place to start matching. */
2932 /* If a fastmap is supplied, skip quickly over characters that
2933 cannot be the start of a match. If the pattern can match the
2934 null string, however, we don't need to skip characters; we want
2935 the first null string. */
2936 if (fastmap && startpos < total_size && !bufp->can_be_null)
2938 if (range > 0) /* Searching forwards. */
2940 register const char *d;
2941 register int lim = 0;
2944 if (startpos < size1 && startpos + range >= size1)
2945 lim = range - (size1 - startpos);
2947 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
2949 /* Written out as an if-else to avoid testing `translate'
2953 && !fastmap[(unsigned char)
2954 translate[(unsigned char) *d++]])
2957 while (range > lim && !fastmap[(unsigned char) *d++])
2960 startpos += irange - range;
2962 else /* Searching backwards. */
2964 register char c = (size1 == 0 || startpos >= size1
2965 ? string2[startpos - size1]
2966 : string1[startpos]);
2968 if (!fastmap[(unsigned char) TRANSLATE (c)])
2973 /* If can't match the null string, and that's all we have left, fail. */
2974 if (range >= 0 && startpos == total_size && fastmap
2975 && !bufp->can_be_null)
2978 val = re_match_2 (bufp, string1, size1, string2, size2,
2979 startpos, regs, stop);
3003 /* Declarations and macros for re_match_2. */
3005 static int bcmp_translate ();
3006 static boolean alt_match_null_string_p (),
3007 common_op_match_null_string_p (),
3008 group_match_null_string_p ();
3010 /* Structure for per-register (a.k.a. per-group) information.
3011 This must not be longer than one word, because we push this value
3012 onto the failure stack. Other register information, such as the
3013 starting and ending positions (which are addresses), and the list of
3014 inner groups (which is a bits list) are maintained in separate
3017 We are making a (strictly speaking) nonportable assumption here: that
3018 the compiler will pack our bit fields into something that fits into
3019 the type of `word', i.e., is something that fits into one item on the
3023 fail_stack_elt_t word;
3026 /* This field is one if this group can match the empty string,
3027 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
3028 #define MATCH_NULL_UNSET_VALUE 3
3029 unsigned match_null_string_p : 2;
3030 unsigned is_active : 1;
3031 unsigned matched_something : 1;
3032 unsigned ever_matched_something : 1;
3034 } register_info_type;
3036 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
3037 #define IS_ACTIVE(R) ((R).bits.is_active)
3038 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
3039 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
3042 /* Call this when have matched a real character; it sets `matched' flags
3043 for the subexpressions which we are currently inside. Also records
3044 that those subexprs have matched. */
3045 #define SET_REGS_MATCHED() \
3049 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
3051 MATCHED_SOMETHING (reg_info[r]) \
3052 = EVER_MATCHED_SOMETHING (reg_info[r]) \
3059 /* This converts PTR, a pointer into one of the search strings `string1'
3060 and `string2' into an offset from the beginning of that string. */
3061 #define POINTER_TO_OFFSET(ptr) \
3062 (FIRST_STRING_P (ptr) ? (ptr) - string1 : (ptr) - string2 + size1)
3064 /* Registers are set to a sentinel when they haven't yet matched. */
3065 #define REG_UNSET_VALUE ((char *) -1)
3066 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
3069 /* Macros for dealing with the split strings in re_match_2. */
3071 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3073 /* Call before fetching a character with *d. This switches over to
3074 string2 if necessary. */
3075 #define PREFETCH() \
3078 /* End of string2 => fail. */ \
3079 if (dend == end_match_2) \
3081 /* End of string1 => advance to string2. */ \
3083 dend = end_match_2; \
3087 /* Test if at very beginning or at very end of the virtual concatenation
3088 of `string1' and `string2'. If only one string, it's `string2'. */
3089 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3090 #define AT_STRINGS_END(d) ((d) == end2)
3093 /* Test if D points to a character which is word-constituent. We have
3094 two special cases to check for: if past the end of string1, look at
3095 the first character in string2; and if before the beginning of
3096 string2, look at the last character in string1. */
3097 #define WORDCHAR_P(d) \
3098 (SYNTAX ((d) == end1 ? *string2 \
3099 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3102 /* Test if the character before D and the one at D differ with respect
3103 to being word-constituent. */
3104 #define AT_WORD_BOUNDARY(d) \
3105 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3106 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3109 /* Free everything we malloc. */
3111 #define FREE_VAR(var) if (var) free (var); var = NULL
3112 #define FREE_VARIABLES() \
3114 FREE_VAR (fail_stack.stack); \
3115 FREE_VAR (regstart); \
3116 FREE_VAR (regend); \
3117 FREE_VAR (old_regstart); \
3118 FREE_VAR (old_regend); \
3119 FREE_VAR (best_regstart); \
3120 FREE_VAR (best_regend); \
3121 FREE_VAR (reg_info); \
3122 FREE_VAR (reg_dummy); \
3123 FREE_VAR (reg_info_dummy); \
3125 #else /* not REGEX_MALLOC */
3126 /* Some MIPS systems (at least) want this to free alloca'd storage. */
3127 #define FREE_VARIABLES() alloca (0)
3128 #endif /* not REGEX_MALLOC */
3131 /* These values must meet several constraints. They must not be valid
3132 register values; since we have a limit of 255 registers (because
3133 we use only one byte in the pattern for the register number), we can
3134 use numbers larger than 255. They must differ by 1, because of
3135 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3136 be larger than the value for the highest register, so we do not try
3137 to actually save any registers when none are active. */
3138 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3139 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3141 /* Matching routines. */
3143 #ifndef emacs /* Emacs never uses this. */
3144 /* re_match is like re_match_2 except it takes only a single string. */
3147 re_match (bufp, string, size, pos, regs)
3148 struct re_pattern_buffer *bufp;
3151 struct re_registers *regs;
3153 return re_match_2 (bufp, NULL, 0, string, size, pos, regs, size);
3155 #endif /* not emacs */
3158 /* re_match_2 matches the compiled pattern in BUFP against the
3159 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3160 and SIZE2, respectively). We start matching at POS, and stop
3163 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3164 store offsets for the substring each group matched in REGS. See the
3165 documentation for exactly how many groups we fill.
3167 We return -1 if no match, -2 if an internal error (such as the
3168 failure stack overflowing). Otherwise, we return the length of the
3169 matched substring. */
3172 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3173 struct re_pattern_buffer *bufp;
3174 const char *string1, *string2;
3177 struct re_registers *regs;
3180 /* General temporaries. */
3184 /* Just past the end of the corresponding string. */
3185 const char *end1, *end2;
3187 /* Pointers into string1 and string2, just past the last characters in
3188 each to consider matching. */
3189 const char *end_match_1, *end_match_2;
3191 /* Where we are in the data, and the end of the current string. */
3192 const char *d, *dend;
3194 /* Where we are in the pattern, and the end of the pattern. */
3195 unsigned char *p = bufp->buffer;
3196 register unsigned char *pend = p + bufp->used;
3198 /* We use this to map every character in the string. */
3199 char *translate = bufp->translate;
3201 /* Failure point stack. Each place that can handle a failure further
3202 down the line pushes a failure point on this stack. It consists of
3203 restart, regend, and reg_info for all registers corresponding to
3204 the subexpressions we're currently inside, plus the number of such
3205 registers, and, finally, two char *'s. The first char * is where
3206 to resume scanning the pattern; the second one is where to resume
3207 scanning the strings. If the latter is zero, the failure point is
3208 a ``dummy''; if a failure happens and the failure point is a dummy,
3209 it gets discarded and the next next one is tried. */
3210 fail_stack_type fail_stack;
3212 static unsigned failure_id = 0;
3213 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3216 /* We fill all the registers internally, independent of what we
3217 return, for use in backreferences. The number here includes
3218 an element for register zero. */
3219 unsigned num_regs = bufp->re_nsub + 1;
3221 /* The currently active registers. */
3222 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3223 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3225 /* Information on the contents of registers. These are pointers into
3226 the input strings; they record just what was matched (on this
3227 attempt) by a subexpression part of the pattern, that is, the
3228 regnum-th regstart pointer points to where in the pattern we began
3229 matching and the regnum-th regend points to right after where we
3230 stopped matching the regnum-th subexpression. (The zeroth register
3231 keeps track of what the whole pattern matches.) */
3232 const char **regstart = NULL, **regend = NULL;
3234 /* If a group that's operated upon by a repetition operator fails to
3235 match anything, then the register for its start will need to be
3236 restored because it will have been set to wherever in the string we
3237 are when we last see its open-group operator. Similarly for a
3239 const char **old_regstart = NULL, **old_regend = NULL;
3241 /* The is_active field of reg_info helps us keep track of which (possibly
3242 nested) subexpressions we are currently in. The matched_something
3243 field of reg_info[reg_num] helps us tell whether or not we have
3244 matched any of the pattern so far this time through the reg_num-th
3245 subexpression. These two fields get reset each time through any
3246 loop their register is in. */
3247 register_info_type *reg_info = NULL;
3249 /* The following record the register info as found in the above
3250 variables when we find a match better than any we've seen before.
3251 This happens as we backtrack through the failure points, which in
3252 turn happens only if we have not yet matched the entire string. */
3253 unsigned best_regs_set = false;
3254 const char **best_regstart = NULL, **best_regend = NULL;
3256 /* Logically, this is `best_regend[0]'. But we don't want to have to
3257 allocate space for that if we're not allocating space for anything
3258 else (see below). Also, we never need info about register 0 for
3259 any of the other register vectors, and it seems rather a kludge to
3260 treat `best_regend' differently than the rest. So we keep track of
3261 the end of the best match so far in a separate variable. We
3262 initialize this to NULL so that when we backtrack the first time
3263 and need to test it, it's not garbage. */
3264 const char *match_end = NULL;
3266 /* Used when we pop values we don't care about. */
3267 const char **reg_dummy = NULL;
3268 register_info_type *reg_info_dummy = NULL;
3271 /* Counts the total number of registers pushed. */
3272 unsigned num_regs_pushed = 0;
3275 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3279 /* Do not bother to initialize all the register variables if there are
3280 no groups in the pattern, as it takes a fair amount of time. If
3281 there are groups, we include space for register 0 (the whole
3282 pattern), even though we never use it, since it simplifies the
3283 array indexing. We should fix this. */
3286 regstart = REGEX_TALLOC (num_regs, const char *);
3287 regend = REGEX_TALLOC (num_regs, const char *);
3288 old_regstart = REGEX_TALLOC (num_regs, const char *);
3289 old_regend = REGEX_TALLOC (num_regs, const char *);
3290 best_regstart = REGEX_TALLOC (num_regs, const char *);
3291 best_regend = REGEX_TALLOC (num_regs, const char *);
3292 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3293 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3294 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3296 if (!(regstart && regend && old_regstart && old_regend && reg_info
3297 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3306 /* We must initialize all our variables to NULL, so that
3307 `FREE_VARIABLES' doesn't try to free them. */
3308 regstart = regend = old_regstart = old_regend = best_regstart
3309 = best_regend = reg_dummy = NULL;
3310 reg_info = reg_info_dummy = (register_info_type *) NULL;
3312 #endif /* REGEX_MALLOC */
3314 /* The starting position is bogus. */
3315 if (pos < 0 || pos > size1 + size2)
3321 /* Initialize subexpression text positions to -1 to mark ones that no
3322 start_memory/stop_memory has been seen for. Also initialize the
3323 register information struct. */
3324 for (mcnt = 1; mcnt < num_regs; mcnt++)
3326 regstart[mcnt] = regend[mcnt]
3327 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3329 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3330 IS_ACTIVE (reg_info[mcnt]) = 0;
3331 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3332 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3335 /* We move `string1' into `string2' if the latter's empty -- but not if
3336 `string1' is null. */
3337 if (size2 == 0 && string1 != NULL)
3344 end1 = string1 + size1;
3345 end2 = string2 + size2;
3347 /* Compute where to stop matching, within the two strings. */
3350 end_match_1 = string1 + stop;
3351 end_match_2 = string2;
3356 end_match_2 = string2 + stop - size1;
3359 /* `p' scans through the pattern as `d' scans through the data.
3360 `dend' is the end of the input string that `d' points within. `d'
3361 is advanced into the following input string whenever necessary, but
3362 this happens before fetching; therefore, at the beginning of the
3363 loop, `d' can be pointing at the end of a string, but it cannot
3365 if (size1 > 0 && pos <= size1)
3372 d = string2 + pos - size1;
3376 DEBUG_PRINT1 ("The compiled pattern is: ");
3377 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3378 DEBUG_PRINT1 ("The string to match is: `");
3379 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3380 DEBUG_PRINT1 ("'\n");
3382 /* This loops over pattern commands. It exits by returning from the
3383 function if the match is complete, or it drops through if the match
3384 fails at this starting point in the input data. */
3387 DEBUG_PRINT2 ("\n0x%x: ", p);
3390 { /* End of pattern means we might have succeeded. */
3391 DEBUG_PRINT1 ("end of pattern ... ");
3393 /* If we haven't matched the entire string, and we want the
3394 longest match, try backtracking. */
3395 if (d != end_match_2)
3397 DEBUG_PRINT1 ("backtracking.\n");
3399 if (!FAIL_STACK_EMPTY ())
3400 { /* More failure points to try. */
3401 boolean same_str_p = (FIRST_STRING_P (match_end)
3402 == MATCHING_IN_FIRST_STRING);
3404 /* If exceeds best match so far, save it. */
3406 || (same_str_p && d > match_end)
3407 || (!same_str_p && !MATCHING_IN_FIRST_STRING))
3409 best_regs_set = true;
3412 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3414 for (mcnt = 1; mcnt < num_regs; mcnt++)
3416 best_regstart[mcnt] = regstart[mcnt];
3417 best_regend[mcnt] = regend[mcnt];
3423 /* If no failure points, don't restore garbage. */
3424 else if (best_regs_set)
3427 /* Restore best match. It may happen that `dend ==
3428 end_match_1' while the restored d is in string2.
3429 For example, the pattern `x.*y.*z' against the
3430 strings `x-' and `y-z-', if the two strings are
3431 not consecutive in memory. */
3432 DEBUG_PRINT1 ("Restoring best registers.\n");
3435 dend = ((d >= string1 && d <= end1)
3436 ? end_match_1 : end_match_2);
3438 for (mcnt = 1; mcnt < num_regs; mcnt++)
3440 regstart[mcnt] = best_regstart[mcnt];
3441 regend[mcnt] = best_regend[mcnt];
3444 } /* d != end_match_2 */
3446 DEBUG_PRINT1 ("Accepting match.\n");
3448 /* If caller wants register contents data back, do it. */
3449 if (regs && !bufp->no_sub)
3451 /* Have the register data arrays been allocated? */
3452 if (bufp->regs_allocated == REGS_UNALLOCATED)
3453 { /* No. So allocate them with malloc. We need one
3454 extra element beyond `num_regs' for the `-1' marker
3456 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3457 regs->start = TALLOC (regs->num_regs, regoff_t);
3458 regs->end = TALLOC (regs->num_regs, regoff_t);
3459 if (regs->start == NULL || regs->end == NULL)
3461 bufp->regs_allocated = REGS_REALLOCATE;
3463 else if (bufp->regs_allocated == REGS_REALLOCATE)
3464 { /* Yes. If we need more elements than were already
3465 allocated, reallocate them. If we need fewer, just
3467 if (regs->num_regs < num_regs + 1)
3469 regs->num_regs = num_regs + 1;
3470 RETALLOC (regs->start, regs->num_regs, regoff_t);
3471 RETALLOC (regs->end, regs->num_regs, regoff_t);
3472 if (regs->start == NULL || regs->end == NULL)
3477 assert (bufp->regs_allocated == REGS_FIXED);
3479 /* Convert the pointer data in `regstart' and `regend' to
3480 indices. Register zero has to be set differently,
3481 since we haven't kept track of any info for it. */
3482 if (regs->num_regs > 0)
3484 regs->start[0] = pos;
3485 regs->end[0] = (MATCHING_IN_FIRST_STRING ? d - string1
3486 : d - string2 + size1);
3489 /* Go through the first `min (num_regs, regs->num_regs)'
3490 registers, since that is all we initialized. */
3491 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3493 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3494 regs->start[mcnt] = regs->end[mcnt] = -1;
3497 regs->start[mcnt] = POINTER_TO_OFFSET (regstart[mcnt]);
3498 regs->end[mcnt] = POINTER_TO_OFFSET (regend[mcnt]);
3502 /* If the regs structure we return has more elements than
3503 were in the pattern, set the extra elements to -1. If
3504 we (re)allocated the registers, this is the case,
3505 because we always allocate enough to have at least one
3507 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3508 regs->start[mcnt] = regs->end[mcnt] = -1;
3509 } /* regs && !bufp->no_sub */
3512 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3513 nfailure_points_pushed, nfailure_points_popped,
3514 nfailure_points_pushed - nfailure_points_popped);
3515 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3517 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3521 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3526 /* Otherwise match next pattern command. */
3527 #ifdef SWITCH_ENUM_BUG
3528 switch ((int) ((re_opcode_t) *p++))
3530 switch ((re_opcode_t) *p++)
3533 /* Ignore these. Used to ignore the n of succeed_n's which
3534 currently have n == 0. */
3536 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3540 /* Match the next n pattern characters exactly. The following
3541 byte in the pattern defines n, and the n bytes after that
3542 are the characters to match. */
3545 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3547 /* This is written out as an if-else so we don't waste time
3548 testing `translate' inside the loop. */
3554 if (translate[(unsigned char) *d++] != (char) *p++)
3564 if (*d++ != (char) *p++) goto fail;
3568 SET_REGS_MATCHED ();
3572 /* Match any character except possibly a newline or a null. */
3574 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3578 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3579 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3582 SET_REGS_MATCHED ();
3583 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3591 register unsigned char c;
3592 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3594 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3597 c = TRANSLATE (*d); /* The character to match. */
3599 /* Cast to `unsigned' instead of `unsigned char' in case the
3600 bit list is a full 32 bytes long. */
3601 if (c < (unsigned) (*p * BYTEWIDTH)
3602 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3607 if (!not) goto fail;
3609 SET_REGS_MATCHED ();
3615 /* The beginning of a group is represented by start_memory.
3616 The arguments are the register number in the next byte, and the
3617 number of groups inner to this one in the next. The text
3618 matched within the group is recorded (in the internal
3619 registers data structure) under the register number. */
3621 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3623 /* Find out if this group can match the empty string. */
3624 p1 = p; /* To send to group_match_null_string_p. */
3626 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3627 REG_MATCH_NULL_STRING_P (reg_info[*p])
3628 = group_match_null_string_p (&p1, pend, reg_info);
3630 /* Save the position in the string where we were the last time
3631 we were at this open-group operator in case the group is
3632 operated upon by a repetition operator, e.g., with `(a*)*b'
3633 against `ab'; then we want to ignore where we are now in
3634 the string in case this attempt to match fails. */
3635 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3636 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3638 DEBUG_PRINT2 (" old_regstart: %d\n",
3639 POINTER_TO_OFFSET (old_regstart[*p]));
3642 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
3644 IS_ACTIVE (reg_info[*p]) = 1;
3645 MATCHED_SOMETHING (reg_info[*p]) = 0;
3647 /* This is the new highest active register. */
3648 highest_active_reg = *p;
3650 /* If nothing was active before, this is the new lowest active
3652 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3653 lowest_active_reg = *p;
3655 /* Move past the register number and inner group count. */
3660 /* The stop_memory opcode represents the end of a group. Its
3661 arguments are the same as start_memory's: the register
3662 number, and the number of inner groups. */
3664 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
3666 /* We need to save the string position the last time we were at
3667 this close-group operator in case the group is operated
3668 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
3669 against `aba'; then we want to ignore where we are now in
3670 the string in case this attempt to match fails. */
3671 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3672 ? REG_UNSET (regend[*p]) ? d : regend[*p]
3674 DEBUG_PRINT2 (" old_regend: %d\n",
3675 POINTER_TO_OFFSET (old_regend[*p]));
3678 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
3680 /* This register isn't active anymore. */
3681 IS_ACTIVE (reg_info[*p]) = 0;
3683 /* If this was the only register active, nothing is active
3685 if (lowest_active_reg == highest_active_reg)
3687 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3688 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3691 { /* We must scan for the new highest active register, since
3692 it isn't necessarily one less than now: consider
3693 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
3694 new highest active register is 1. */
3695 unsigned char r = *p - 1;
3696 while (r > 0 && !IS_ACTIVE (reg_info[r]))
3699 /* If we end up at register zero, that means that we saved
3700 the registers as the result of an `on_failure_jump', not
3701 a `start_memory', and we jumped to past the innermost
3702 `stop_memory'. For example, in ((.)*) we save
3703 registers 1 and 2 as a result of the *, but when we pop
3704 back to the second ), we are at the stop_memory 1.
3705 Thus, nothing is active. */
3708 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3709 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3712 highest_active_reg = r;
3715 /* If just failed to match something this time around with a
3716 group that's operated on by a repetition operator, try to
3717 force exit from the ``loop'', and restore the register
3718 information for this group that we had before trying this
3720 if ((!MATCHED_SOMETHING (reg_info[*p])
3721 || (re_opcode_t) p[-3] == start_memory)
3724 boolean is_a_jump_n = false;
3728 switch ((re_opcode_t) *p1++)
3732 case pop_failure_jump:
3733 case maybe_pop_jump:
3735 case dummy_failure_jump:
3736 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3746 /* If the next operation is a jump backwards in the pattern
3747 to an on_failure_jump right before the start_memory
3748 corresponding to this stop_memory, exit from the loop
3749 by forcing a failure after pushing on the stack the
3750 on_failure_jump's jump in the pattern, and d. */
3751 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
3752 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
3754 /* If this group ever matched anything, then restore
3755 what its registers were before trying this last
3756 failed match, e.g., with `(a*)*b' against `ab' for
3757 regstart[1], and, e.g., with `((a*)*(b*)*)*'
3758 against `aba' for regend[3].
3760 Also restore the registers for inner groups for,
3761 e.g., `((a*)(b*))*' against `aba' (register 3 would
3762 otherwise get trashed). */
3764 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
3768 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
3770 /* Restore this and inner groups' (if any) registers. */
3771 for (r = *p; r < *p + *(p + 1); r++)
3773 regstart[r] = old_regstart[r];
3775 /* xx why this test? */
3776 if ((int) old_regend[r] >= (int) regstart[r])
3777 regend[r] = old_regend[r];
3781 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3782 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
3788 /* Move past the register number and the inner group count. */
3793 /* \<digit> has been turned into a `duplicate' command which is
3794 followed by the numeric value of <digit> as the register number. */
3797 register const char *d2, *dend2;
3798 int regno = *p++; /* Get which register to match against. */
3799 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
3801 /* Can't back reference a group which we've never matched. */
3802 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
3805 /* Where in input to try to start matching. */
3806 d2 = regstart[regno];
3808 /* Where to stop matching; if both the place to start and
3809 the place to stop matching are in the same string, then
3810 set to the place to stop, otherwise, for now have to use
3811 the end of the first string. */
3813 dend2 = ((FIRST_STRING_P (regstart[regno])
3814 == FIRST_STRING_P (regend[regno]))
3815 ? regend[regno] : end_match_1);
3818 /* If necessary, advance to next segment in register
3822 if (dend2 == end_match_2) break;
3823 if (dend2 == regend[regno]) break;
3825 /* End of string1 => advance to string2. */
3827 dend2 = regend[regno];
3829 /* At end of register contents => success */
3830 if (d2 == dend2) break;
3832 /* If necessary, advance to next segment in data. */
3835 /* How many characters left in this segment to match. */
3838 /* Want how many consecutive characters we can match in
3839 one shot, so, if necessary, adjust the count. */
3840 if (mcnt > dend2 - d2)
3843 /* Compare that many; failure if mismatch, else move
3846 ? bcmp_translate (d, d2, mcnt, translate)
3847 : bcmp (d, d2, mcnt))
3849 d += mcnt, d2 += mcnt;
3855 /* begline matches the empty string at the beginning of the string
3856 (unless `not_bol' is set in `bufp'), and, if
3857 `newline_anchor' is set, after newlines. */
3859 DEBUG_PRINT1 ("EXECUTING begline.\n");
3861 if (AT_STRINGS_BEG (d))
3863 if (!bufp->not_bol) break;
3865 else if (d[-1] == '\n' && bufp->newline_anchor)
3869 /* In all other cases, we fail. */
3873 /* endline is the dual of begline. */
3875 DEBUG_PRINT1 ("EXECUTING endline.\n");
3877 if (AT_STRINGS_END (d))
3879 if (!bufp->not_eol) break;
3882 /* We have to ``prefetch'' the next character. */
3883 else if ((d == end1 ? *string2 : *d) == '\n'
3884 && bufp->newline_anchor)
3891 /* Match at the very beginning of the data. */
3893 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
3894 if (AT_STRINGS_BEG (d))
3899 /* Match at the very end of the data. */
3901 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
3902 if (AT_STRINGS_END (d))
3907 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
3908 pushes NULL as the value for the string on the stack. Then
3909 `pop_failure_point' will keep the current value for the
3910 string, instead of restoring it. To see why, consider
3911 matching `foo\nbar' against `.*\n'. The .* matches the foo;
3912 then the . fails against the \n. But the next thing we want
3913 to do is match the \n against the \n; if we restored the
3914 string value, we would be back at the foo.
3916 Because this is used only in specific cases, we don't need to
3917 check all the things that `on_failure_jump' does, to make
3918 sure the right things get saved on the stack. Hence we don't
3919 share its code. The only reason to push anything on the
3920 stack at all is that otherwise we would have to change
3921 `anychar's code to do something besides goto fail in this
3922 case; that seems worse than this. */
3923 case on_failure_keep_string_jump:
3924 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
3926 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3927 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
3929 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
3933 /* Uses of on_failure_jump:
3935 Each alternative starts with an on_failure_jump that points
3936 to the beginning of the next alternative. Each alternative
3937 except the last ends with a jump that in effect jumps past
3938 the rest of the alternatives. (They really jump to the
3939 ending jump of the following alternative, because tensioning
3940 these jumps is a hassle.)
3942 Repeats start with an on_failure_jump that points past both
3943 the repetition text and either the following jump or
3944 pop_failure_jump back to this on_failure_jump. */
3945 case on_failure_jump:
3947 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
3949 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3950 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
3952 /* If this on_failure_jump comes right before a group (i.e.,
3953 the original * applied to a group), save the information
3954 for that group and all inner ones, so that if we fail back
3955 to this point, the group's information will be correct.
3956 For example, in \(a*\)*\1, we need the preceding group,
3957 and in \(\(a*\)b*\)\2, we need the inner group. */
3959 /* We can't use `p' to check ahead because we push
3960 a failure point to `p + mcnt' after we do this. */
3963 /* We need to skip no_op's before we look for the
3964 start_memory in case this on_failure_jump is happening as
3965 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
3967 while (p1 < pend && (re_opcode_t) *p1 == no_op)
3970 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
3972 /* We have a new highest active register now. This will
3973 get reset at the start_memory we are about to get to,
3974 but we will have saved all the registers relevant to
3975 this repetition op, as described above. */
3976 highest_active_reg = *(p1 + 1) + *(p1 + 2);
3977 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3978 lowest_active_reg = *(p1 + 1);
3981 DEBUG_PRINT1 (":\n");
3982 PUSH_FAILURE_POINT (p + mcnt, d, -2);
3986 /* A smart repeat ends with `maybe_pop_jump'.
3987 We change it to either `pop_failure_jump' or `jump'. */
3988 case maybe_pop_jump:
3989 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3990 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
3992 register unsigned char *p2 = p;
3994 /* Compare the beginning of the repeat with what in the
3995 pattern follows its end. If we can establish that there
3996 is nothing that they would both match, i.e., that we
3997 would have to backtrack because of (as in, e.g., `a*a')
3998 then we can change to pop_failure_jump, because we'll
3999 never have to backtrack.
4001 This is not true in the case of alternatives: in
4002 `(a|ab)*' we do need to backtrack to the `ab' alternative
4003 (e.g., if the string was `ab'). But instead of trying to
4004 detect that here, the alternative has put on a dummy
4005 failure point which is what we will end up popping. */
4007 /* Skip over open/close-group commands. */
4008 while (p2 + 2 < pend
4009 && ((re_opcode_t) *p2 == stop_memory
4010 || (re_opcode_t) *p2 == start_memory))
4011 p2 += 3; /* Skip over args, too. */
4013 /* If we're at the end of the pattern, we can change. */
4016 /* Consider what happens when matching ":\(.*\)"
4017 against ":/". I don't really understand this code
4019 p[-3] = (unsigned char) pop_failure_jump;
4021 (" End of pattern: change to `pop_failure_jump'.\n");
4024 else if ((re_opcode_t) *p2 == exactn
4025 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4027 register unsigned char c
4028 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4031 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4032 to the `maybe_finalize_jump' of this case. Examine what
4034 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4036 p[-3] = (unsigned char) pop_failure_jump;
4037 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4041 else if ((re_opcode_t) p1[3] == charset
4042 || (re_opcode_t) p1[3] == charset_not)
4044 int not = (re_opcode_t) p1[3] == charset_not;
4046 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4047 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4050 /* `not' is equal to 1 if c would match, which means
4051 that we can't change to pop_failure_jump. */
4054 p[-3] = (unsigned char) pop_failure_jump;
4055 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4060 p -= 2; /* Point at relative address again. */
4061 if ((re_opcode_t) p[-1] != pop_failure_jump)
4063 p[-1] = (unsigned char) jump;
4064 DEBUG_PRINT1 (" Match => jump.\n");
4065 goto unconditional_jump;
4067 /* Note fall through. */
4070 /* The end of a simple repeat has a pop_failure_jump back to
4071 its matching on_failure_jump, where the latter will push a
4072 failure point. The pop_failure_jump takes off failure
4073 points put on by this pop_failure_jump's matching
4074 on_failure_jump; we got through the pattern to here from the
4075 matching on_failure_jump, so didn't fail. */
4076 case pop_failure_jump:
4078 /* We need to pass separate storage for the lowest and
4079 highest registers, even though we don't care about the
4080 actual values. Otherwise, we will restore only one
4081 register from the stack, since lowest will == highest in
4082 `pop_failure_point'. */
4083 unsigned dummy_low_reg, dummy_high_reg;
4084 unsigned char *pdummy;
4087 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4088 POP_FAILURE_POINT (sdummy, pdummy,
4089 dummy_low_reg, dummy_high_reg,
4090 reg_dummy, reg_dummy, reg_info_dummy);
4092 /* Note fall through. */
4095 /* Unconditionally jump (without popping any failure points). */
4098 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4099 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4100 p += mcnt; /* Do the jump. */
4101 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4105 /* We need this opcode so we can detect where alternatives end
4106 in `group_match_null_string_p' et al. */
4108 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4109 goto unconditional_jump;
4112 /* Normally, the on_failure_jump pushes a failure point, which
4113 then gets popped at pop_failure_jump. We will end up at
4114 pop_failure_jump, also, and with a pattern of, say, `a+', we
4115 are skipping over the on_failure_jump, so we have to push
4116 something meaningless for pop_failure_jump to pop. */
4117 case dummy_failure_jump:
4118 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4119 /* It doesn't matter what we push for the string here. What
4120 the code at `fail' tests is the value for the pattern. */
4121 PUSH_FAILURE_POINT (0, 0, -2);
4122 goto unconditional_jump;
4125 /* At the end of an alternative, we need to push a dummy failure
4126 point in case we are followed by a `pop_failure_jump', because
4127 we don't want the failure point for the alternative to be
4128 popped. For example, matching `(a|ab)*' against `aab'
4129 requires that we match the `ab' alternative. */
4130 case push_dummy_failure:
4131 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4132 /* See comments just above at `dummy_failure_jump' about the
4134 PUSH_FAILURE_POINT (0, 0, -2);
4137 /* Have to succeed matching what follows at least n times.
4138 After that, handle like `on_failure_jump'. */
4140 EXTRACT_NUMBER (mcnt, p + 2);
4141 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4144 /* Originally, this is how many times we HAVE to succeed. */
4149 STORE_NUMBER_AND_INCR (p, mcnt);
4150 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4154 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4155 p[2] = (unsigned char) no_op;
4156 p[3] = (unsigned char) no_op;
4162 EXTRACT_NUMBER (mcnt, p + 2);
4163 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4165 /* Originally, this is how many times we CAN jump. */
4169 STORE_NUMBER (p + 2, mcnt);
4170 goto unconditional_jump;
4172 /* If don't have to jump any more, skip over the rest of command. */
4179 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4181 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4183 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4184 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4185 STORE_NUMBER (p1, mcnt);
4190 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4191 if (AT_WORD_BOUNDARY (d))
4196 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4197 if (AT_WORD_BOUNDARY (d))
4202 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4203 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4208 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4209 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4210 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4217 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4218 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4223 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4224 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4229 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4230 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4233 #else /* not emacs19 */
4235 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4236 if (PTR_CHAR_POS ((unsigned char *) d) + 1 != point)
4239 #endif /* not emacs19 */
4242 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4247 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4251 if (SYNTAX (*d++) != (enum syntaxcode) mcnt)
4253 SET_REGS_MATCHED ();
4257 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4259 goto matchnotsyntax;
4262 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4266 if (SYNTAX (*d++) == (enum syntaxcode) mcnt)
4268 SET_REGS_MATCHED ();
4271 #else /* not emacs */
4273 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4275 if (!WORDCHAR_P (d))
4277 SET_REGS_MATCHED ();
4282 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4286 SET_REGS_MATCHED ();
4289 #endif /* not emacs */
4294 continue; /* Successfully executed one pattern command; keep going. */
4297 /* We goto here if a matching operation fails. */
4299 if (!FAIL_STACK_EMPTY ())
4300 { /* A restart point is known. Restore to that state. */
4301 DEBUG_PRINT1 ("\nFAIL:\n");
4302 POP_FAILURE_POINT (d, p,
4303 lowest_active_reg, highest_active_reg,
4304 regstart, regend, reg_info);
4306 /* If this failure point is a dummy, try the next one. */
4310 /* If we failed to the end of the pattern, don't examine *p. */
4314 boolean is_a_jump_n = false;
4316 /* If failed to a backwards jump that's part of a repetition
4317 loop, need to pop this failure point and use the next one. */
4318 switch ((re_opcode_t) *p)
4322 case maybe_pop_jump:
4323 case pop_failure_jump:
4326 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4329 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4331 && (re_opcode_t) *p1 == on_failure_jump))
4339 if (d >= string1 && d <= end1)
4343 break; /* Matching at this starting point really fails. */
4347 goto restore_best_regs;
4351 return -1; /* Failure to match. */
4354 /* Subroutine definitions for re_match_2. */
4357 /* We are passed P pointing to a register number after a start_memory.
4359 Return true if the pattern up to the corresponding stop_memory can
4360 match the empty string, and false otherwise.
4362 If we find the matching stop_memory, sets P to point to one past its number.
4363 Otherwise, sets P to an undefined byte less than or equal to END.
4365 We don't handle duplicates properly (yet). */
4368 group_match_null_string_p (p, end, reg_info)
4369 unsigned char **p, *end;
4370 register_info_type *reg_info;
4373 /* Point to after the args to the start_memory. */
4374 unsigned char *p1 = *p + 2;
4378 /* Skip over opcodes that can match nothing, and return true or
4379 false, as appropriate, when we get to one that can't, or to the
4380 matching stop_memory. */
4382 switch ((re_opcode_t) *p1)
4384 /* Could be either a loop or a series of alternatives. */
4385 case on_failure_jump:
4387 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4389 /* If the next operation is not a jump backwards in the
4394 /* Go through the on_failure_jumps of the alternatives,
4395 seeing if any of the alternatives cannot match nothing.
4396 The last alternative starts with only a jump,
4397 whereas the rest start with on_failure_jump and end
4398 with a jump, e.g., here is the pattern for `a|b|c':
4400 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4401 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4404 So, we have to first go through the first (n-1)
4405 alternatives and then deal with the last one separately. */
4408 /* Deal with the first (n-1) alternatives, which start
4409 with an on_failure_jump (see above) that jumps to right
4410 past a jump_past_alt. */
4412 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4414 /* `mcnt' holds how many bytes long the alternative
4415 is, including the ending `jump_past_alt' and
4418 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4422 /* Move to right after this alternative, including the
4426 /* Break if it's the beginning of an n-th alternative
4427 that doesn't begin with an on_failure_jump. */
4428 if ((re_opcode_t) *p1 != on_failure_jump)
4431 /* Still have to check that it's not an n-th
4432 alternative that starts with an on_failure_jump. */
4434 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4435 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4437 /* Get to the beginning of the n-th alternative. */
4443 /* Deal with the last alternative: go back and get number
4444 of the `jump_past_alt' just before it. `mcnt' contains
4445 the length of the alternative. */
4446 EXTRACT_NUMBER (mcnt, p1 - 2);
4448 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4451 p1 += mcnt; /* Get past the n-th alternative. */
4457 assert (p1[1] == **p);
4463 if (!common_op_match_null_string_p (&p1, end, reg_info))
4466 } /* while p1 < end */
4469 } /* group_match_null_string_p */
4472 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4473 It expects P to be the first byte of a single alternative and END one
4474 byte past the last. The alternative can contain groups. */
4477 alt_match_null_string_p (p, end, reg_info)
4478 unsigned char *p, *end;
4479 register_info_type *reg_info;
4482 unsigned char *p1 = p;
4486 /* Skip over opcodes that can match nothing, and break when we get
4487 to one that can't. */
4489 switch ((re_opcode_t) *p1)
4492 case on_failure_jump:
4494 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4499 if (!common_op_match_null_string_p (&p1, end, reg_info))
4502 } /* while p1 < end */
4505 } /* alt_match_null_string_p */
4508 /* Deals with the ops common to group_match_null_string_p and
4509 alt_match_null_string_p.
4511 Sets P to one after the op and its arguments, if any. */
4514 common_op_match_null_string_p (p, end, reg_info)
4515 unsigned char **p, *end;
4516 register_info_type *reg_info;
4521 unsigned char *p1 = *p;
4523 switch ((re_opcode_t) *p1++)
4543 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
4544 ret = group_match_null_string_p (&p1, end, reg_info);
4546 /* Have to set this here in case we're checking a group which
4547 contains a group and a back reference to it. */
4549 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
4550 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
4556 /* If this is an optimized succeed_n for zero times, make the jump. */
4558 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4566 /* Get to the number of times to succeed. */
4568 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4573 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4581 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
4589 /* All other opcodes mean we cannot match the empty string. */
4595 } /* common_op_match_null_string_p */
4598 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
4599 bytes; nonzero otherwise. */
4602 bcmp_translate (s1, s2, len, translate)
4603 unsigned char *s1, *s2;
4607 register unsigned char *p1 = s1, *p2 = s2;
4610 if (translate[*p1++] != translate[*p2++]) return 1;
4616 /* Entry points for GNU code. */
4618 /* re_compile_pattern is the GNU regular expression compiler: it
4619 compiles PATTERN (of length SIZE) and puts the result in BUFP.
4620 Returns 0 if the pattern was valid, otherwise an error string.
4622 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
4623 are set in BUFP on entry.
4625 We call regex_compile to do the actual compilation. */
4628 re_compile_pattern (pattern, length, bufp)
4629 const char *pattern;
4631 struct re_pattern_buffer *bufp;
4635 /* GNU code is written to assume at least RE_NREGS registers will be set
4636 (and at least one extra will be -1). */
4637 bufp->regs_allocated = REGS_UNALLOCATED;
4639 /* And GNU code determines whether or not to get register information
4640 by passing null for the REGS argument to re_match, etc., not by
4644 /* Match anchors at newline. */
4645 bufp->newline_anchor = 1;
4647 ret = regex_compile (pattern, length, re_syntax_options, bufp);
4649 return re_error_msg[(int) ret];
4652 /* Entry points compatible with 4.2 BSD regex library. We don't define
4653 them if this is an Emacs or POSIX compilation. */
4655 #if !defined (emacs) && !defined (_POSIX_SOURCE)
4657 /* BSD has one and only one pattern buffer. */
4658 static struct re_pattern_buffer re_comp_buf;
4668 if (!re_comp_buf.buffer)
4669 return "No previous regular expression";
4673 if (!re_comp_buf.buffer)
4675 re_comp_buf.buffer = (unsigned char *) malloc (200);
4676 if (re_comp_buf.buffer == NULL)
4677 return "Memory exhausted";
4678 re_comp_buf.allocated = 200;
4680 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
4681 if (re_comp_buf.fastmap == NULL)
4682 return "Memory exhausted";
4685 /* Since `re_exec' always passes NULL for the `regs' argument, we
4686 don't need to initialize the pattern buffer fields which affect it. */
4688 /* Match anchors at newlines. */
4689 re_comp_buf.newline_anchor = 1;
4691 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
4693 /* Yes, we're discarding `const' here. */
4694 return (char *) re_error_msg[(int) ret];
4702 const int len = strlen (s);
4704 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
4706 #endif /* not emacs and not _POSIX_SOURCE */
4708 /* POSIX.2 functions. Don't define these for Emacs. */
4712 /* regcomp takes a regular expression as a string and compiles it.
4714 PREG is a regex_t *. We do not expect any fields to be initialized,
4715 since POSIX says we shouldn't. Thus, we set
4717 `buffer' to the compiled pattern;
4718 `used' to the length of the compiled pattern;
4719 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
4720 REG_EXTENDED bit in CFLAGS is set; otherwise, to
4721 RE_SYNTAX_POSIX_BASIC;
4722 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
4723 `fastmap' and `fastmap_accurate' to zero;
4724 `re_nsub' to the number of subexpressions in PATTERN.
4726 PATTERN is the address of the pattern string.
4728 CFLAGS is a series of bits which affect compilation.
4730 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
4731 use POSIX basic syntax.
4733 If REG_NEWLINE is set, then . and [^...] don't match newline.
4734 Also, regexec will try a match beginning after every newline.
4736 If REG_ICASE is set, then we considers upper- and lowercase
4737 versions of letters to be equivalent when matching.
4739 If REG_NOSUB is set, then when PREG is passed to regexec, that
4740 routine will report only success or failure, and nothing about the
4743 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
4744 the return codes and their meanings.) */
4747 regcomp (preg, pattern, cflags)
4749 const char *pattern;
4754 = (cflags & REG_EXTENDED) ?
4755 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
4757 /* regex_compile will allocate the space for the compiled pattern. */
4759 preg->allocated = 0;
4761 /* Don't bother to use a fastmap when searching. This simplifies the
4762 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
4763 characters after newlines into the fastmap. This way, we just try
4767 if (cflags & REG_ICASE)
4771 preg->translate = (char *) malloc (CHAR_SET_SIZE);
4772 if (preg->translate == NULL)
4773 return (int) REG_ESPACE;
4775 /* Map uppercase characters to corresponding lowercase ones. */
4776 for (i = 0; i < CHAR_SET_SIZE; i++)
4777 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
4780 preg->translate = NULL;
4782 /* If REG_NEWLINE is set, newlines are treated differently. */
4783 if (cflags & REG_NEWLINE)
4784 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
4785 syntax &= ~RE_DOT_NEWLINE;
4786 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
4787 /* It also changes the matching behavior. */
4788 preg->newline_anchor = 1;
4791 preg->newline_anchor = 0;
4793 preg->no_sub = !!(cflags & REG_NOSUB);
4795 /* POSIX says a null character in the pattern terminates it, so we
4796 can use strlen here in compiling the pattern. */
4797 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
4799 /* POSIX doesn't distinguish between an unmatched open-group and an
4800 unmatched close-group: both are REG_EPAREN. */
4801 if (ret == REG_ERPAREN) ret = REG_EPAREN;
4807 /* regexec searches for a given pattern, specified by PREG, in the
4810 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
4811 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
4812 least NMATCH elements, and we set them to the offsets of the
4813 corresponding matched substrings.
4815 EFLAGS specifies `execution flags' which affect matching: if
4816 REG_NOTBOL is set, then ^ does not match at the beginning of the
4817 string; if REG_NOTEOL is set, then $ does not match at the end.
4819 We return 0 if we find a match and REG_NOMATCH if not. */
4822 regexec (preg, string, nmatch, pmatch, eflags)
4823 const regex_t *preg;
4826 regmatch_t pmatch[];
4830 struct re_registers regs;
4831 regex_t private_preg;
4832 int len = strlen (string);
4833 boolean want_reg_info = !preg->no_sub && nmatch > 0;
4835 private_preg = *preg;
4837 private_preg.not_bol = !!(eflags & REG_NOTBOL);
4838 private_preg.not_eol = !!(eflags & REG_NOTEOL);
4840 /* The user has told us exactly how many registers to return
4841 information about, via `nmatch'. We have to pass that on to the
4842 matching routines. */
4843 private_preg.regs_allocated = REGS_FIXED;
4847 regs.num_regs = nmatch;
4848 regs.start = TALLOC (nmatch, regoff_t);
4849 regs.end = TALLOC (nmatch, regoff_t);
4850 if (regs.start == NULL || regs.end == NULL)
4851 return (int) REG_NOMATCH;
4854 /* Perform the searching operation. */
4855 ret = re_search (&private_preg, string, len,
4856 /* start: */ 0, /* range: */ len,
4857 want_reg_info ? ®s : (struct re_registers *) 0);
4859 /* Copy the register information to the POSIX structure. */
4866 for (r = 0; r < nmatch; r++)
4868 pmatch[r].rm_so = regs.start[r];
4869 pmatch[r].rm_eo = regs.end[r];
4873 /* If we needed the temporary register info, free the space now. */
4878 /* We want zero return to mean success, unlike `re_search'. */
4879 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
4883 /* Returns a message corresponding to an error code, ERRCODE, returned
4884 from either regcomp or regexec. We don't use PREG here. */
4887 regerror (errcode, preg, errbuf, errbuf_size)
4889 const regex_t *preg;
4897 || errcode >= (sizeof (re_error_msg) / sizeof (re_error_msg[0])))
4898 /* Only error codes returned by the rest of the code should be passed
4899 to this routine. If we are given anything else, or if other regex
4900 code generates an invalid error code, then the program has a bug.
4901 Dump core so we can fix it. */
4904 msg = re_error_msg[errcode];
4906 /* POSIX doesn't require that we do anything in this case, but why
4911 msg_size = strlen (msg) + 1; /* Includes the null. */
4913 if (errbuf_size != 0)
4915 if (msg_size > errbuf_size)
4917 strncpy (errbuf, msg, errbuf_size - 1);
4918 errbuf[errbuf_size - 1] = 0;
4921 strcpy (errbuf, msg);
4928 /* Free dynamically allocated space used by PREG. */
4934 if (preg->buffer != NULL)
4935 free (preg->buffer);
4936 preg->buffer = NULL;
4938 preg->allocated = 0;
4941 if (preg->fastmap != NULL)
4942 free (preg->fastmap);
4943 preg->fastmap = NULL;
4944 preg->fastmap_accurate = 0;
4946 if (preg->translate != NULL)
4947 free (preg->translate);
4948 preg->translate = NULL;
4951 #endif /* not emacs */
4955 make-backup-files: t
4957 trim-versions-without-asking: nil