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>
38 /* The `emacs' switch turns on certain matching commands
39 that make sense only in Emacs. */
46 /* Emacs uses `NULL' as a predicate. */
51 /* We used to test for `BSTRING' here, but only GCC and Emacs define
52 `BSTRING', as far as I know, and neither of them use this code. */
53 #if HAVE_STRING_H || STDC_HEADERS
56 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
59 #define bcopy(s, d, n) memcpy ((d), (s), (n))
62 #define bzero(s, n) memset ((s), 0, (n))
76 /* Define the syntax stuff for \<, \>, etc. */
78 /* This must be nonzero for the wordchar and notwordchar pattern
79 commands in re_match_2. */
86 extern char *re_syntax_table;
88 #else /* not SYNTAX_TABLE */
90 /* How many characters in the character set. */
91 #define CHAR_SET_SIZE 256
93 static char re_syntax_table[CHAR_SET_SIZE];
104 bzero (re_syntax_table, sizeof re_syntax_table);
106 for (c = 'a'; c <= 'z'; c++)
107 re_syntax_table[c] = Sword;
109 for (c = 'A'; c <= 'Z'; c++)
110 re_syntax_table[c] = Sword;
112 for (c = '0'; c <= '9'; c++)
113 re_syntax_table[c] = Sword;
115 re_syntax_table['_'] = Sword;
120 #endif /* not SYNTAX_TABLE */
122 #define SYNTAX(c) re_syntax_table[c]
124 #endif /* not emacs */
126 /* Get the interface, including the syntax bits. */
129 /* isalpha etc. are used for the character classes. */
137 #define ISBLANK(c) (isascii (c) && isblank (c))
139 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
142 #define ISGRAPH(c) (isascii (c) && isgraph (c))
144 #define ISGRAPH(c) (isascii (c) && isprint (c) && !isspace (c))
147 #define ISPRINT(c) (isascii (c) && isprint (c))
148 #define ISDIGIT(c) (isascii (c) && isdigit (c))
149 #define ISALNUM(c) (isascii (c) && isalnum (c))
150 #define ISALPHA(c) (isascii (c) && isalpha (c))
151 #define ISCNTRL(c) (isascii (c) && iscntrl (c))
152 #define ISLOWER(c) (isascii (c) && islower (c))
153 #define ISPUNCT(c) (isascii (c) && ispunct (c))
154 #define ISSPACE(c) (isascii (c) && isspace (c))
155 #define ISUPPER(c) (isascii (c) && isupper (c))
156 #define ISXDIGIT(c) (isascii (c) && isxdigit (c))
162 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
163 since ours (we hope) works properly with all combinations of
164 machines, compilers, `char' and `unsigned char' argument types.
165 (Per Bothner suggested the basic approach.) */
166 #undef SIGN_EXTEND_CHAR
168 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
169 #else /* not __STDC__ */
170 /* As in Harbison and Steele. */
171 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
174 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
175 use `alloca' instead of `malloc'. This is because using malloc in
176 re_search* or re_match* could cause memory leaks when C-g is used in
177 Emacs; also, malloc is slower and causes storage fragmentation. On
178 the other hand, malloc is more portable, and easier to debug.
180 Because we sometimes use alloca, some routines have to be macros,
181 not functions -- `alloca'-allocated space disappears at the end of the
182 function it is called in. */
186 #define REGEX_ALLOCATE malloc
187 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
189 #else /* not REGEX_MALLOC */
191 /* Emacs already defines alloca, sometimes. */
194 /* Make alloca work the best possible way. */
196 #define alloca __builtin_alloca
197 #else /* not __GNUC__ */
200 #else /* not __GNUC__ or HAVE_ALLOCA_H */
201 #ifndef _AIX /* Already did AIX, up at the top. */
203 #endif /* not _AIX */
204 #endif /* not HAVE_ALLOCA_H */
205 #endif /* not __GNUC__ */
207 #endif /* not alloca */
209 #define REGEX_ALLOCATE alloca
211 /* Assumes a `char *destination' variable. */
212 #define REGEX_REALLOCATE(source, osize, nsize) \
213 (destination = (char *) alloca (nsize), \
214 bcopy (source, destination, osize), \
217 #endif /* not REGEX_MALLOC */
220 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
221 `string1' or just past its end. This works if PTR is NULL, which is
223 #define FIRST_STRING_P(ptr) \
224 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
226 /* (Re)Allocate N items of type T using malloc, or fail. */
227 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
228 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
229 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
231 #define BYTEWIDTH 8 /* In bits. */
233 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
235 #define MAX(a, b) ((a) > (b) ? (a) : (b))
236 #define MIN(a, b) ((a) < (b) ? (a) : (b))
238 typedef char boolean;
242 /* These are the command codes that appear in compiled regular
243 expressions. Some opcodes are followed by argument bytes. A
244 command code can specify any interpretation whatsoever for its
245 arguments. Zero bytes may appear in the compiled regular expression.
247 The value of `exactn' is needed in search.c (search_buffer) in Emacs.
248 So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of
249 `exactn' we use here must also be 1. */
255 /* Followed by one byte giving n, then by n literal bytes. */
258 /* Matches any (more or less) character. */
261 /* Matches any one char belonging to specified set. First
262 following byte is number of bitmap bytes. Then come bytes
263 for a bitmap saying which chars are in. Bits in each byte
264 are ordered low-bit-first. A character is in the set if its
265 bit is 1. A character too large to have a bit in the map is
266 automatically not in the set. */
269 /* Same parameters as charset, but match any character that is
270 not one of those specified. */
273 /* Start remembering the text that is matched, for storing in a
274 register. Followed by one byte with the register number, in
275 the range 0 to one less than the pattern buffer's re_nsub
276 field. Then followed by one byte with the number of groups
277 inner to this one. (This last has to be part of the
278 start_memory only because we need it in the on_failure_jump
282 /* Stop remembering the text that is matched and store it in a
283 memory register. Followed by one byte with the register
284 number, in the range 0 to one less than `re_nsub' in the
285 pattern buffer, and one byte with the number of inner groups,
286 just like `start_memory'. (We need the number of inner
287 groups here because we don't have any easy way of finding the
288 corresponding start_memory when we're at a stop_memory.) */
291 /* Match a duplicate of something remembered. Followed by one
292 byte containing the register number. */
295 /* Fail unless at beginning of line. */
298 /* Fail unless at end of line. */
301 /* Succeeds if at beginning of buffer (if emacs) or at beginning
302 of string to be matched (if not). */
305 /* Analogously, for end of buffer/string. */
308 /* Followed by two byte relative address to which to jump. */
311 /* Same as jump, but marks the end of an alternative. */
314 /* Followed by two-byte relative address of place to resume at
315 in case of failure. */
318 /* Like on_failure_jump, but pushes a placeholder instead of the
319 current string position when executed. */
320 on_failure_keep_string_jump,
322 /* Throw away latest failure point and then jump to following
323 two-byte relative address. */
326 /* Change to pop_failure_jump if know won't have to backtrack to
327 match; otherwise change to jump. This is used to jump
328 back to the beginning of a repeat. If what follows this jump
329 clearly won't match what the repeat does, such that we can be
330 sure that there is no use backtracking out of repetitions
331 already matched, then we change it to a pop_failure_jump.
332 Followed by two-byte address. */
335 /* Jump to following two-byte address, and push a dummy failure
336 point. This failure point will be thrown away if an attempt
337 is made to use it for a failure. A `+' construct makes this
338 before the first repeat. Also used as an intermediary kind
339 of jump when compiling an alternative. */
342 /* Push a dummy failure point and continue. Used at the end of
346 /* Followed by two-byte relative address and two-byte number n.
347 After matching N times, jump to the address upon failure. */
350 /* Followed by two-byte relative address, and two-byte number n.
351 Jump to the address N times, then fail. */
354 /* Set the following two-byte relative address to the
355 subsequent two-byte number. The address *includes* the two
359 wordchar, /* Matches any word-constituent character. */
360 notwordchar, /* Matches any char that is not a word-constituent. */
362 wordbeg, /* Succeeds if at word beginning. */
363 wordend, /* Succeeds if at word end. */
365 wordbound, /* Succeeds if at a word boundary. */
366 notwordbound /* Succeeds if not at a word boundary. */
369 ,before_dot, /* Succeeds if before point. */
370 at_dot, /* Succeeds if at point. */
371 after_dot, /* Succeeds if after point. */
373 /* Matches any character whose syntax is specified. Followed by
374 a byte which contains a syntax code, e.g., Sword. */
377 /* Matches any character whose syntax is not that specified. */
382 /* Common operations on the compiled pattern. */
384 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
386 #define STORE_NUMBER(destination, number) \
388 (destination)[0] = (number) & 0377; \
389 (destination)[1] = (number) >> 8; \
392 /* Same as STORE_NUMBER, except increment DESTINATION to
393 the byte after where the number is stored. Therefore, DESTINATION
394 must be an lvalue. */
396 #define STORE_NUMBER_AND_INCR(destination, number) \
398 STORE_NUMBER (destination, number); \
399 (destination) += 2; \
402 /* Put into DESTINATION a number stored in two contiguous bytes starting
405 #define EXTRACT_NUMBER(destination, source) \
407 (destination) = *(source) & 0377; \
408 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
413 extract_number (dest, source)
415 unsigned char *source;
417 int temp = SIGN_EXTEND_CHAR (*(source + 1));
418 *dest = *source & 0377;
422 #ifndef EXTRACT_MACROS /* To debug the macros. */
423 #undef EXTRACT_NUMBER
424 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
425 #endif /* not EXTRACT_MACROS */
429 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
430 SOURCE must be an lvalue. */
432 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
434 EXTRACT_NUMBER (destination, source); \
440 extract_number_and_incr (destination, source)
442 unsigned char **source;
444 extract_number (destination, *source);
448 #ifndef EXTRACT_MACROS
449 #undef EXTRACT_NUMBER_AND_INCR
450 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
451 extract_number_and_incr (&dest, &src)
452 #endif /* not EXTRACT_MACROS */
456 /* If DEBUG is defined, Regex prints many voluminous messages about what
457 it is doing (if the variable `debug' is nonzero). If linked with the
458 main program in `iregex.c', you can enter patterns and strings
459 interactively. And if linked with the main program in `main.c' and
460 the other test files, you can run the already-written tests. */
464 /* We use standard I/O for debugging. */
467 /* It is useful to test things that ``must'' be true when debugging. */
470 static int debug = 0;
472 #define DEBUG_STATEMENT(e) e
473 #define DEBUG_PRINT1(x) if (debug) printf (x)
474 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
475 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
476 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
477 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
478 if (debug) print_partial_compiled_pattern (s, e)
479 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
480 if (debug) print_double_string (w, s1, sz1, s2, sz2)
483 extern void printchar ();
485 /* Print the fastmap in human-readable form. */
488 print_fastmap (fastmap)
491 unsigned was_a_range = 0;
494 while (i < (1 << BYTEWIDTH))
500 while (i < (1 << BYTEWIDTH) && fastmap[i])
516 /* Print a compiled pattern string in human-readable form, starting at
517 the START pointer into it and ending just before the pointer END. */
520 print_partial_compiled_pattern (start, end)
521 unsigned char *start;
525 unsigned char *p = start;
526 unsigned char *pend = end;
534 /* Loop over pattern commands. */
537 switch ((re_opcode_t) *p++)
545 printf ("/exactn/%d", mcnt);
556 printf ("/start_memory/%d/%d", mcnt, *p++);
561 printf ("/stop_memory/%d/%d", mcnt, *p++);
565 printf ("/duplicate/%d", *p++);
577 printf ("/charset%s",
578 (re_opcode_t) *(p - 1) == charset_not ? "_not" : "");
580 assert (p + *p < pend);
582 for (c = 0; c < *p; c++)
585 unsigned char map_byte = p[1 + c];
589 for (bit = 0; bit < BYTEWIDTH; bit++)
590 if (map_byte & (1 << bit))
591 printchar (c * BYTEWIDTH + bit);
605 case on_failure_jump:
606 extract_number_and_incr (&mcnt, &p);
607 printf ("/on_failure_jump/0/%d", mcnt);
610 case on_failure_keep_string_jump:
611 extract_number_and_incr (&mcnt, &p);
612 printf ("/on_failure_keep_string_jump/0/%d", mcnt);
615 case dummy_failure_jump:
616 extract_number_and_incr (&mcnt, &p);
617 printf ("/dummy_failure_jump/0/%d", mcnt);
620 case push_dummy_failure:
621 printf ("/push_dummy_failure");
625 extract_number_and_incr (&mcnt, &p);
626 printf ("/maybe_pop_jump/0/%d", mcnt);
629 case pop_failure_jump:
630 extract_number_and_incr (&mcnt, &p);
631 printf ("/pop_failure_jump/0/%d", mcnt);
635 extract_number_and_incr (&mcnt, &p);
636 printf ("/jump_past_alt/0/%d", mcnt);
640 extract_number_and_incr (&mcnt, &p);
641 printf ("/jump/0/%d", mcnt);
645 extract_number_and_incr (&mcnt, &p);
646 extract_number_and_incr (&mcnt2, &p);
647 printf ("/succeed_n/0/%d/0/%d", mcnt, mcnt2);
651 extract_number_and_incr (&mcnt, &p);
652 extract_number_and_incr (&mcnt2, &p);
653 printf ("/jump_n/0/%d/0/%d", mcnt, mcnt2);
657 extract_number_and_incr (&mcnt, &p);
658 extract_number_and_incr (&mcnt2, &p);
659 printf ("/set_number_at/0/%d/0/%d", mcnt, mcnt2);
663 printf ("/wordbound");
667 printf ("/notwordbound");
679 printf ("/before_dot");
687 printf ("/after_dot");
691 printf ("/syntaxspec");
693 printf ("/%d", mcnt);
697 printf ("/notsyntaxspec");
699 printf ("/%d", mcnt);
704 printf ("/wordchar");
708 printf ("/notwordchar");
720 printf ("?%d", *(p-1));
728 print_compiled_pattern (bufp)
729 struct re_pattern_buffer *bufp;
731 unsigned char *buffer = bufp->buffer;
733 print_partial_compiled_pattern (buffer, buffer + bufp->used);
734 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
736 if (bufp->fastmap_accurate && bufp->fastmap)
738 printf ("fastmap: ");
739 print_fastmap (bufp->fastmap);
742 printf ("re_nsub: %d\t", bufp->re_nsub);
743 printf ("regs_alloc: %d\t", bufp->regs_allocated);
744 printf ("can_be_null: %d\t", bufp->can_be_null);
745 printf ("newline_anchor: %d\n", bufp->newline_anchor);
746 printf ("no_sub: %d\t", bufp->no_sub);
747 printf ("not_bol: %d\t", bufp->not_bol);
748 printf ("not_eol: %d\t", bufp->not_eol);
749 printf ("syntax: %d\n", bufp->syntax);
750 /* Perhaps we should print the translate table? */
755 print_double_string (where, string1, size1, string2, size2)
768 if (FIRST_STRING_P (where))
770 for (this_char = where - string1; this_char < size1; this_char++)
771 printchar (string1[this_char]);
776 for (this_char = where - string2; this_char < size2; this_char++)
777 printchar (string2[this_char]);
781 #else /* not DEBUG */
786 #define DEBUG_STATEMENT(e)
787 #define DEBUG_PRINT1(x)
788 #define DEBUG_PRINT2(x1, x2)
789 #define DEBUG_PRINT3(x1, x2, x3)
790 #define DEBUG_PRINT4(x1, x2, x3, x4)
791 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
792 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
794 #endif /* not DEBUG */
796 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
797 also be assigned to arbitrarily: each pattern buffer stores its own
798 syntax, so it can be changed between regex compilations. */
799 reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS;
802 /* Specify the precise syntax of regexps for compilation. This provides
803 for compatibility for various utilities which historically have
804 different, incompatible syntaxes.
806 The argument SYNTAX is a bit mask comprised of the various bits
807 defined in regex.h. We return the old syntax. */
810 re_set_syntax (syntax)
813 reg_syntax_t ret = re_syntax_options;
815 re_syntax_options = syntax;
819 /* This table gives an error message for each of the error codes listed
820 in regex.h. Obviously the order here has to be same as there. */
822 static const char *re_error_msg[] =
823 { NULL, /* REG_NOERROR */
824 "No match", /* REG_NOMATCH */
825 "Invalid regular expression", /* REG_BADPAT */
826 "Invalid collation character", /* REG_ECOLLATE */
827 "Invalid character class name", /* REG_ECTYPE */
828 "Trailing backslash", /* REG_EESCAPE */
829 "Invalid back reference", /* REG_ESUBREG */
830 "Unmatched [ or [^", /* REG_EBRACK */
831 "Unmatched ( or \\(", /* REG_EPAREN */
832 "Unmatched \\{", /* REG_EBRACE */
833 "Invalid content of \\{\\}", /* REG_BADBR */
834 "Invalid range end", /* REG_ERANGE */
835 "Memory exhausted", /* REG_ESPACE */
836 "Invalid preceding regular expression", /* REG_BADRPT */
837 "Premature end of regular expression", /* REG_EEND */
838 "Regular expression too big", /* REG_ESIZE */
839 "Unmatched ) or \\)", /* REG_ERPAREN */
842 /* Subroutine declarations and macros for regex_compile. */
844 static void store_op1 (), store_op2 ();
845 static void insert_op1 (), insert_op2 ();
846 static boolean at_begline_loc_p (), at_endline_loc_p ();
847 static boolean group_in_compile_stack ();
848 static reg_errcode_t compile_range ();
850 /* Fetch the next character in the uncompiled pattern---translating it
851 if necessary. Also cast from a signed character in the constant
852 string passed to us by the user to an unsigned char that we can use
853 as an array index (in, e.g., `translate'). */
854 #define PATFETCH(c) \
855 do {if (p == pend) return REG_EEND; \
856 c = (unsigned char) *p++; \
857 if (translate) c = translate[c]; \
860 /* Fetch the next character in the uncompiled pattern, with no
862 #define PATFETCH_RAW(c) \
863 do {if (p == pend) return REG_EEND; \
864 c = (unsigned char) *p++; \
867 /* Go backwards one character in the pattern. */
868 #define PATUNFETCH p--
871 /* If `translate' is non-null, return translate[D], else just D. We
872 cast the subscript to translate because some data is declared as
873 `char *', to avoid warnings when a string constant is passed. But
874 when we use a character as a subscript we must make it unsigned. */
875 #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
878 /* Macros for outputting the compiled pattern into `buffer'. */
880 /* If the buffer isn't allocated when it comes in, use this. */
881 #define INIT_BUF_SIZE 32
883 /* Make sure we have at least N more bytes of space in buffer. */
884 #define GET_BUFFER_SPACE(n) \
885 while (b - bufp->buffer + (n) > bufp->allocated) \
888 /* Make sure we have one more byte of buffer space and then add C to it. */
889 #define BUF_PUSH(c) \
891 GET_BUFFER_SPACE (1); \
892 *b++ = (unsigned char) (c); \
896 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
897 #define BUF_PUSH_2(c1, c2) \
899 GET_BUFFER_SPACE (2); \
900 *b++ = (unsigned char) (c1); \
901 *b++ = (unsigned char) (c2); \
905 /* As with BUF_PUSH_2, except for three bytes. */
906 #define BUF_PUSH_3(c1, c2, c3) \
908 GET_BUFFER_SPACE (3); \
909 *b++ = (unsigned char) (c1); \
910 *b++ = (unsigned char) (c2); \
911 *b++ = (unsigned char) (c3); \
915 /* Store a jump with opcode OP at LOC to location TO. We store a
916 relative address offset by the three bytes the jump itself occupies. */
917 #define STORE_JUMP(op, loc, to) \
918 store_op1 (op, loc, (to) - (loc) - 3)
920 /* Likewise, for a two-argument jump. */
921 #define STORE_JUMP2(op, loc, to, arg) \
922 store_op2 (op, loc, (to) - (loc) - 3, arg)
924 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
925 #define INSERT_JUMP(op, loc, to) \
926 insert_op1 (op, loc, (to) - (loc) - 3, b)
928 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
929 #define INSERT_JUMP2(op, loc, to, arg) \
930 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
933 /* This is not an arbitrary limit: the arguments which represent offsets
934 into the pattern are two bytes long. So if 2^16 bytes turns out to
935 be too small, many things would have to change. */
936 #define MAX_BUF_SIZE (1L << 16)
939 /* Extend the buffer by twice its current size via realloc and
940 reset the pointers that pointed into the old block to point to the
941 correct places in the new one. If extending the buffer results in it
942 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
943 #define EXTEND_BUFFER() \
945 unsigned char *old_buffer = bufp->buffer; \
946 if (bufp->allocated == MAX_BUF_SIZE) \
948 bufp->allocated <<= 1; \
949 if (bufp->allocated > MAX_BUF_SIZE) \
950 bufp->allocated = MAX_BUF_SIZE; \
951 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
952 if (bufp->buffer == NULL) \
954 /* If the buffer moved, move all the pointers into it. */ \
955 if (old_buffer != bufp->buffer) \
957 b = (b - old_buffer) + bufp->buffer; \
958 begalt = (begalt - old_buffer) + bufp->buffer; \
959 if (fixup_alt_jump) \
960 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
962 laststart = (laststart - old_buffer) + bufp->buffer; \
964 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
969 /* Since we have one byte reserved for the register number argument to
970 {start,stop}_memory, the maximum number of groups we can report
971 things about is what fits in that byte. */
972 #define MAX_REGNUM 255
974 /* But patterns can have more than `MAX_REGNUM' registers. We just
975 ignore the excess. */
976 typedef unsigned regnum_t;
979 /* Macros for the compile stack. */
981 /* Since offsets can go either forwards or backwards, this type needs to
982 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
983 typedef int pattern_offset_t;
987 pattern_offset_t begalt_offset;
988 pattern_offset_t fixup_alt_jump;
989 pattern_offset_t inner_group_offset;
990 pattern_offset_t laststart_offset;
992 } compile_stack_elt_t;
997 compile_stack_elt_t *stack;
999 unsigned avail; /* Offset of next open position. */
1000 } compile_stack_type;
1003 #define INIT_COMPILE_STACK_SIZE 32
1005 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
1006 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
1008 /* The next available element. */
1009 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
1012 /* Set the bit for character C in a list. */
1013 #define SET_LIST_BIT(c) \
1014 (b[((unsigned char) (c)) / BYTEWIDTH] \
1015 |= 1 << (((unsigned char) c) % BYTEWIDTH))
1018 /* Get the next unsigned number in the uncompiled pattern. */
1019 #define GET_UNSIGNED_NUMBER(num) \
1023 while (ISDIGIT (c)) \
1027 num = num * 10 + c - '0'; \
1035 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1037 #define IS_CHAR_CLASS(string) \
1038 (STREQ (string, "alpha") || STREQ (string, "upper") \
1039 || STREQ (string, "lower") || STREQ (string, "digit") \
1040 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1041 || STREQ (string, "space") || STREQ (string, "print") \
1042 || STREQ (string, "punct") || STREQ (string, "graph") \
1043 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1045 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1046 Returns one of error codes defined in `regex.h', or zero for success.
1048 Assumes the `allocated' (and perhaps `buffer') and `translate'
1049 fields are set in BUFP on entry.
1051 If it succeeds, results are put in BUFP (if it returns an error, the
1052 contents of BUFP are undefined):
1053 `buffer' is the compiled pattern;
1054 `syntax' is set to SYNTAX;
1055 `used' is set to the length of the compiled pattern;
1056 `fastmap_accurate' is zero;
1057 `re_nsub' is the number of subexpressions in PATTERN;
1058 `not_bol' and `not_eol' are zero;
1060 The `fastmap' and `newline_anchor' fields are neither
1061 examined nor set. */
1063 static reg_errcode_t
1064 regex_compile (pattern, size, syntax, bufp)
1065 const char *pattern;
1067 reg_syntax_t syntax;
1068 struct re_pattern_buffer *bufp;
1070 /* We fetch characters from PATTERN here. Even though PATTERN is
1071 `char *' (i.e., signed), we declare these variables as unsigned, so
1072 they can be reliably used as array indices. */
1073 register unsigned char c, c1;
1075 /* A random tempory spot in PATTERN. */
1078 /* Points to the end of the buffer, where we should append. */
1079 register unsigned char *b;
1081 /* Keeps track of unclosed groups. */
1082 compile_stack_type compile_stack;
1084 /* Points to the current (ending) position in the pattern. */
1085 const char *p = pattern;
1086 const char *pend = pattern + size;
1088 /* How to translate the characters in the pattern. */
1089 char *translate = bufp->translate;
1091 /* Address of the count-byte of the most recently inserted `exactn'
1092 command. This makes it possible to tell if a new exact-match
1093 character can be added to that command or if the character requires
1094 a new `exactn' command. */
1095 unsigned char *pending_exact = 0;
1097 /* Address of start of the most recently finished expression.
1098 This tells, e.g., postfix * where to find the start of its
1099 operand. Reset at the beginning of groups and alternatives. */
1100 unsigned char *laststart = 0;
1102 /* Address of beginning of regexp, or inside of last group. */
1103 unsigned char *begalt;
1105 /* Place in the uncompiled pattern (i.e., the {) to
1106 which to go back if the interval is invalid. */
1107 const char *beg_interval;
1109 /* Address of the place where a forward jump should go to the end of
1110 the containing expression. Each alternative of an `or' -- except the
1111 last -- ends with a forward jump of this sort. */
1112 unsigned char *fixup_alt_jump = 0;
1114 /* Counts open-groups as they are encountered. Remembered for the
1115 matching close-group on the compile stack, so the same register
1116 number is put in the stop_memory as the start_memory. */
1117 regnum_t regnum = 0;
1120 DEBUG_PRINT1 ("\nCompiling pattern: ");
1123 unsigned debug_count;
1125 for (debug_count = 0; debug_count < size; debug_count++)
1126 printchar (pattern[debug_count]);
1131 /* Initialize the compile stack. */
1132 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1133 if (compile_stack.stack == NULL)
1136 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1137 compile_stack.avail = 0;
1139 /* Initialize the pattern buffer. */
1140 bufp->syntax = syntax;
1141 bufp->fastmap_accurate = 0;
1142 bufp->not_bol = bufp->not_eol = 0;
1144 /* Set `used' to zero, so that if we return an error, the pattern
1145 printer (for debugging) will think there's no pattern. We reset it
1149 /* Always count groups, whether or not bufp->no_sub is set. */
1152 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1153 /* Initialize the syntax table. */
1154 init_syntax_once ();
1157 if (bufp->allocated == 0)
1160 { /* If zero allocated, but buffer is non-null, try to realloc
1161 enough space. This loses if buffer's address is bogus, but
1162 that is the user's responsibility. */
1163 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1166 { /* Caller did not allocate a buffer. Do it for them. */
1167 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1169 if (!bufp->buffer) return REG_ESPACE;
1171 bufp->allocated = INIT_BUF_SIZE;
1174 begalt = b = bufp->buffer;
1176 /* Loop through the uncompiled pattern until we're at the end. */
1185 if ( /* If at start of pattern, it's an operator. */
1187 /* If context independent, it's an operator. */
1188 || syntax & RE_CONTEXT_INDEP_ANCHORS
1189 /* Otherwise, depends on what's come before. */
1190 || at_begline_loc_p (pattern, p, syntax))
1200 if ( /* If at end of pattern, it's an operator. */
1202 /* If context independent, it's an operator. */
1203 || syntax & RE_CONTEXT_INDEP_ANCHORS
1204 /* Otherwise, depends on what's next. */
1205 || at_endline_loc_p (p, pend, syntax))
1215 if ((syntax & RE_BK_PLUS_QM)
1216 || (syntax & RE_LIMITED_OPS))
1220 /* If there is no previous pattern... */
1223 if (syntax & RE_CONTEXT_INVALID_OPS)
1225 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1230 /* Are we optimizing this jump? */
1231 boolean keep_string_p = false;
1233 /* 1 means zero (many) matches is allowed. */
1234 char zero_times_ok = 0, many_times_ok = 0;
1236 /* If there is a sequence of repetition chars, collapse it
1237 down to just one (the right one). We can't combine
1238 interval operators with these because of, e.g., `a{2}*',
1239 which should only match an even number of `a's. */
1243 zero_times_ok |= c != '+';
1244 many_times_ok |= c != '?';
1252 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1255 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1257 if (p == pend) return REG_EESCAPE;
1260 if (!(c1 == '+' || c1 == '?'))
1275 /* If we get here, we found another repeat character. */
1278 /* Star, etc. applied to an empty pattern is equivalent
1279 to an empty pattern. */
1283 /* Now we know whether or not zero matches is allowed
1284 and also whether or not two or more matches is allowed. */
1286 { /* More than one repetition is allowed, so put in at the
1287 end a backward relative jump from `b' to before the next
1288 jump we're going to put in below (which jumps from
1289 laststart to after this jump).
1291 But if we are at the `*' in the exact sequence `.*\n',
1292 insert an unconditional jump backwards to the .,
1293 instead of the beginning of the loop. This way we only
1294 push a failure point once, instead of every time
1295 through the loop. */
1296 assert (p - 1 > pattern);
1298 /* Allocate the space for the jump. */
1299 GET_BUFFER_SPACE (3);
1301 /* We know we are not at the first character of the pattern,
1302 because laststart was nonzero. And we've already
1303 incremented `p', by the way, to be the character after
1304 the `*'. Do we have to do something analogous here
1305 for null bytes, because of RE_DOT_NOT_NULL? */
1306 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1308 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1309 && !(syntax & RE_DOT_NEWLINE))
1310 { /* We have .*\n. */
1311 STORE_JUMP (jump, b, laststart);
1312 keep_string_p = true;
1315 /* Anything else. */
1316 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1318 /* We've added more stuff to the buffer. */
1322 /* On failure, jump from laststart to b + 3, which will be the
1323 end of the buffer after this jump is inserted. */
1324 GET_BUFFER_SPACE (3);
1325 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1333 /* At least one repetition is required, so insert a
1334 `dummy_failure_jump' before the initial
1335 `on_failure_jump' instruction of the loop. This
1336 effects a skip over that instruction the first time
1337 we hit that loop. */
1338 GET_BUFFER_SPACE (3);
1339 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1354 boolean had_char_class = false;
1356 if (p == pend) return REG_EBRACK;
1358 /* Ensure that we have enough space to push a charset: the
1359 opcode, the length count, and the bitset; 34 bytes in all. */
1360 GET_BUFFER_SPACE (34);
1364 /* We test `*p == '^' twice, instead of using an if
1365 statement, so we only need one BUF_PUSH. */
1366 BUF_PUSH (*p == '^' ? charset_not : charset);
1370 /* Remember the first position in the bracket expression. */
1373 /* Push the number of bytes in the bitmap. */
1374 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1376 /* Clear the whole map. */
1377 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1379 /* charset_not matches newline according to a syntax bit. */
1380 if ((re_opcode_t) b[-2] == charset_not
1381 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1382 SET_LIST_BIT ('\n');
1384 /* Read in characters and ranges, setting map bits. */
1387 if (p == pend) return REG_EBRACK;
1391 /* \ might escape characters inside [...] and [^...]. */
1392 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1394 if (p == pend) return REG_EESCAPE;
1401 /* Could be the end of the bracket expression. If it's
1402 not (i.e., when the bracket expression is `[]' so
1403 far), the ']' character bit gets set way below. */
1404 if (c == ']' && p != p1 + 1)
1407 /* Look ahead to see if it's a range when the last thing
1408 was a character class. */
1409 if (had_char_class && c == '-' && *p != ']')
1412 /* Look ahead to see if it's a range when the last thing
1413 was a character: if this is a hyphen not at the
1414 beginning or the end of a list, then it's the range
1417 && !(p - 2 >= pattern && p[-2] == '[')
1418 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1422 = compile_range (&p, pend, translate, syntax, b);
1423 if (ret != REG_NOERROR) return ret;
1426 else if (p[0] == '-' && p[1] != ']')
1427 { /* This handles ranges made up of characters only. */
1430 /* Move past the `-'. */
1433 ret = compile_range (&p, pend, translate, syntax, b);
1434 if (ret != REG_NOERROR) return ret;
1437 /* See if we're at the beginning of a possible character
1440 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1441 { /* Leave room for the null. */
1442 char str[CHAR_CLASS_MAX_LENGTH + 1];
1447 /* If pattern is `[[:'. */
1448 if (p == pend) return REG_EBRACK;
1453 if (c == ':' || c == ']' || p == pend
1454 || c1 == CHAR_CLASS_MAX_LENGTH)
1460 /* If isn't a word bracketed by `[:' and:`]':
1461 undo the ending character, the letters, and leave
1462 the leading `:' and `[' (but set bits for them). */
1463 if (c == ':' && *p == ']')
1466 boolean is_alnum = STREQ (str, "alnum");
1467 boolean is_alpha = STREQ (str, "alpha");
1468 boolean is_blank = STREQ (str, "blank");
1469 boolean is_cntrl = STREQ (str, "cntrl");
1470 boolean is_digit = STREQ (str, "digit");
1471 boolean is_graph = STREQ (str, "graph");
1472 boolean is_lower = STREQ (str, "lower");
1473 boolean is_print = STREQ (str, "print");
1474 boolean is_punct = STREQ (str, "punct");
1475 boolean is_space = STREQ (str, "space");
1476 boolean is_upper = STREQ (str, "upper");
1477 boolean is_xdigit = STREQ (str, "xdigit");
1479 if (!IS_CHAR_CLASS (str)) return REG_ECTYPE;
1481 /* Throw away the ] at the end of the character
1485 if (p == pend) return REG_EBRACK;
1487 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
1489 if ( (is_alnum && ISALNUM (ch))
1490 || (is_alpha && ISALPHA (ch))
1491 || (is_blank && ISBLANK (ch))
1492 || (is_cntrl && ISCNTRL (ch))
1493 || (is_digit && ISDIGIT (ch))
1494 || (is_graph && ISGRAPH (ch))
1495 || (is_lower && ISLOWER (ch))
1496 || (is_print && ISPRINT (ch))
1497 || (is_punct && ISPUNCT (ch))
1498 || (is_space && ISSPACE (ch))
1499 || (is_upper && ISUPPER (ch))
1500 || (is_xdigit && ISXDIGIT (ch)))
1503 had_char_class = true;
1512 had_char_class = false;
1517 had_char_class = false;
1522 /* Discard any (non)matching list bytes that are all 0 at the
1523 end of the map. Decrease the map-length byte too. */
1524 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
1532 if (syntax & RE_NO_BK_PARENS)
1539 if (syntax & RE_NO_BK_PARENS)
1546 if (syntax & RE_NEWLINE_ALT)
1553 if (syntax & RE_NO_BK_VBAR)
1560 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
1561 goto handle_interval;
1567 if (p == pend) return REG_EESCAPE;
1569 /* Do not translate the character after the \, so that we can
1570 distinguish, e.g., \B from \b, even if we normally would
1571 translate, e.g., B to b. */
1577 if (syntax & RE_NO_BK_PARENS)
1578 goto normal_backslash;
1584 if (COMPILE_STACK_FULL)
1586 RETALLOC (compile_stack.stack, compile_stack.size << 1,
1587 compile_stack_elt_t);
1588 if (compile_stack.stack == NULL) return REG_ESPACE;
1590 compile_stack.size <<= 1;
1593 /* These are the values to restore when we hit end of this
1594 group. They are all relative offsets, so that if the
1595 whole pattern moves because of realloc, they will still
1597 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
1598 COMPILE_STACK_TOP.fixup_alt_jump
1599 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
1600 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
1601 COMPILE_STACK_TOP.regnum = regnum;
1603 /* We will eventually replace the 0 with the number of
1604 groups inner to this one. But do not push a
1605 start_memory for groups beyond the last one we can
1606 represent in the compiled pattern. */
1607 if (regnum <= MAX_REGNUM)
1609 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
1610 BUF_PUSH_3 (start_memory, regnum, 0);
1613 compile_stack.avail++;
1618 /* If we've reached MAX_REGNUM groups, then this open
1619 won't actually generate any code, so we'll have to
1620 clear pending_exact explicitly. */
1626 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
1628 if (COMPILE_STACK_EMPTY)
1630 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1631 goto normal_backslash;
1638 { /* Push a dummy failure point at the end of the
1639 alternative for a possible future
1640 `pop_failure_jump' to pop. See comments at
1641 `push_dummy_failure' in `re_match_2'. */
1642 BUF_PUSH (push_dummy_failure);
1644 /* We allocated space for this jump when we assigned
1645 to `fixup_alt_jump', in the `handle_alt' case below. */
1646 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
1649 /* See similar code for backslashed left paren above. */
1650 if (COMPILE_STACK_EMPTY)
1652 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1658 /* Since we just checked for an empty stack above, this
1659 ``can't happen''. */
1660 assert (compile_stack.avail != 0);
1662 /* We don't just want to restore into `regnum', because
1663 later groups should continue to be numbered higher,
1664 as in `(ab)c(de)' -- the second group is #2. */
1665 regnum_t this_group_regnum;
1667 compile_stack.avail--;
1668 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
1670 = COMPILE_STACK_TOP.fixup_alt_jump
1671 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
1673 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
1674 this_group_regnum = COMPILE_STACK_TOP.regnum;
1675 /* If we've reached MAX_REGNUM groups, then this open
1676 won't actually generate any code, so we'll have to
1677 clear pending_exact explicitly. */
1680 /* We're at the end of the group, so now we know how many
1681 groups were inside this one. */
1682 if (this_group_regnum <= MAX_REGNUM)
1684 unsigned char *inner_group_loc
1685 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
1687 *inner_group_loc = regnum - this_group_regnum;
1688 BUF_PUSH_3 (stop_memory, this_group_regnum,
1689 regnum - this_group_regnum);
1695 case '|': /* `\|'. */
1696 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
1697 goto normal_backslash;
1699 if (syntax & RE_LIMITED_OPS)
1702 /* Insert before the previous alternative a jump which
1703 jumps to this alternative if the former fails. */
1704 GET_BUFFER_SPACE (3);
1705 INSERT_JUMP (on_failure_jump, begalt, b + 6);
1709 /* The alternative before this one has a jump after it
1710 which gets executed if it gets matched. Adjust that
1711 jump so it will jump to this alternative's analogous
1712 jump (put in below, which in turn will jump to the next
1713 (if any) alternative's such jump, etc.). The last such
1714 jump jumps to the correct final destination. A picture:
1720 If we are at `b', then fixup_alt_jump right now points to a
1721 three-byte space after `a'. We'll put in the jump, set
1722 fixup_alt_jump to right after `b', and leave behind three
1723 bytes which we'll fill in when we get to after `c'. */
1726 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
1728 /* Mark and leave space for a jump after this alternative,
1729 to be filled in later either by next alternative or
1730 when know we're at the end of a series of alternatives. */
1732 GET_BUFFER_SPACE (3);
1741 /* If \{ is a literal. */
1742 if (!(syntax & RE_INTERVALS)
1743 /* If we're at `\{' and it's not the open-interval
1745 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
1746 || (p - 2 == pattern && p == pend))
1747 goto normal_backslash;
1751 /* If got here, then the syntax allows intervals. */
1753 /* At least (most) this many matches must be made. */
1754 int lower_bound = -1, upper_bound = -1;
1756 beg_interval = p - 1;
1760 if (syntax & RE_NO_BK_BRACES)
1761 goto unfetch_interval;
1766 GET_UNSIGNED_NUMBER (lower_bound);
1770 GET_UNSIGNED_NUMBER (upper_bound);
1771 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
1774 /* Interval such as `{1}' => match exactly once. */
1775 upper_bound = lower_bound;
1777 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
1778 || lower_bound > upper_bound)
1780 if (syntax & RE_NO_BK_BRACES)
1781 goto unfetch_interval;
1786 if (!(syntax & RE_NO_BK_BRACES))
1788 if (c != '\\') return REG_EBRACE;
1795 if (syntax & RE_NO_BK_BRACES)
1796 goto unfetch_interval;
1801 /* We just parsed a valid interval. */
1803 /* If it's invalid to have no preceding re. */
1806 if (syntax & RE_CONTEXT_INVALID_OPS)
1808 else if (syntax & RE_CONTEXT_INDEP_OPS)
1811 goto unfetch_interval;
1814 /* If the upper bound is zero, don't want to succeed at
1815 all; jump from `laststart' to `b + 3', which will be
1816 the end of the buffer after we insert the jump. */
1817 if (upper_bound == 0)
1819 GET_BUFFER_SPACE (3);
1820 INSERT_JUMP (jump, laststart, b + 3);
1824 /* Otherwise, we have a nontrivial interval. When
1825 we're all done, the pattern will look like:
1826 set_number_at <jump count> <upper bound>
1827 set_number_at <succeed_n count> <lower bound>
1828 succeed_n <after jump addr> <succed_n count>
1830 jump_n <succeed_n addr> <jump count>
1831 (The upper bound and `jump_n' are omitted if
1832 `upper_bound' is 1, though.) */
1834 { /* If the upper bound is > 1, we need to insert
1835 more at the end of the loop. */
1836 unsigned nbytes = 10 + (upper_bound > 1) * 10;
1838 GET_BUFFER_SPACE (nbytes);
1840 /* Initialize lower bound of the `succeed_n', even
1841 though it will be set during matching by its
1842 attendant `set_number_at' (inserted next),
1843 because `re_compile_fastmap' needs to know.
1844 Jump to the `jump_n' we might insert below. */
1845 INSERT_JUMP2 (succeed_n, laststart,
1846 b + 5 + (upper_bound > 1) * 5,
1850 /* Code to initialize the lower bound. Insert
1851 before the `succeed_n'. The `5' is the last two
1852 bytes of this `set_number_at', plus 3 bytes of
1853 the following `succeed_n'. */
1854 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
1857 if (upper_bound > 1)
1858 { /* More than one repetition is allowed, so
1859 append a backward jump to the `succeed_n'
1860 that starts this interval.
1862 When we've reached this during matching,
1863 we'll have matched the interval once, so
1864 jump back only `upper_bound - 1' times. */
1865 STORE_JUMP2 (jump_n, b, laststart + 5,
1869 /* The location we want to set is the second
1870 parameter of the `jump_n'; that is `b-2' as
1871 an absolute address. `laststart' will be
1872 the `set_number_at' we're about to insert;
1873 `laststart+3' the number to set, the source
1874 for the relative address. But we are
1875 inserting into the middle of the pattern --
1876 so everything is getting moved up by 5.
1877 Conclusion: (b - 2) - (laststart + 3) + 5,
1878 i.e., b - laststart.
1880 We insert this at the beginning of the loop
1881 so that if we fail during matching, we'll
1882 reinitialize the bounds. */
1883 insert_op2 (set_number_at, laststart, b - laststart,
1884 upper_bound - 1, b);
1889 beg_interval = NULL;
1894 /* If an invalid interval, match the characters as literals. */
1895 assert (beg_interval);
1897 beg_interval = NULL;
1899 /* normal_char and normal_backslash need `c'. */
1902 if (!(syntax & RE_NO_BK_BRACES))
1904 if (p > pattern && p[-1] == '\\')
1905 goto normal_backslash;
1910 /* There is no way to specify the before_dot and after_dot
1911 operators. rms says this is ok. --karl */
1919 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
1925 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
1932 BUF_PUSH (wordchar);
1938 BUF_PUSH (notwordchar);
1951 BUF_PUSH (wordbound);
1955 BUF_PUSH (notwordbound);
1966 case '1': case '2': case '3': case '4': case '5':
1967 case '6': case '7': case '8': case '9':
1968 if (syntax & RE_NO_BK_REFS)
1976 /* Can't back reference to a subexpression if inside of it. */
1977 if (group_in_compile_stack (compile_stack, c1))
1981 BUF_PUSH_2 (duplicate, c1);
1987 if (syntax & RE_BK_PLUS_QM)
1990 goto normal_backslash;
1994 /* You might think it would be useful for \ to mean
1995 not to translate; but if we don't translate it
1996 it will never match anything. */
2004 /* Expects the character in `c'. */
2006 /* If no exactn currently being built. */
2009 /* If last exactn not at current position. */
2010 || pending_exact + *pending_exact + 1 != b
2012 /* We have only one byte following the exactn for the count. */
2013 || *pending_exact == (1 << BYTEWIDTH) - 1
2015 /* If followed by a repetition operator. */
2016 || *p == '*' || *p == '^'
2017 || ((syntax & RE_BK_PLUS_QM)
2018 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
2019 : (*p == '+' || *p == '?'))
2020 || ((syntax & RE_INTERVALS)
2021 && ((syntax & RE_NO_BK_BRACES)
2023 : (p[0] == '\\' && p[1] == '{'))))
2025 /* Start building a new exactn. */
2029 BUF_PUSH_2 (exactn, 0);
2030 pending_exact = b - 1;
2037 } /* while p != pend */
2040 /* Through the pattern now. */
2043 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2045 if (!COMPILE_STACK_EMPTY)
2048 free (compile_stack.stack);
2050 /* We have succeeded; set the length of the buffer. */
2051 bufp->used = b - bufp->buffer;
2056 DEBUG_PRINT1 ("\nCompiled pattern: ");
2057 print_compiled_pattern (bufp);
2062 } /* regex_compile */
2064 /* Subroutines for `regex_compile'. */
2066 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2069 store_op1 (op, loc, arg)
2074 *loc = (unsigned char) op;
2075 STORE_NUMBER (loc + 1, arg);
2079 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2082 store_op2 (op, loc, arg1, arg2)
2087 *loc = (unsigned char) op;
2088 STORE_NUMBER (loc + 1, arg1);
2089 STORE_NUMBER (loc + 3, arg2);
2093 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2094 for OP followed by two-byte integer parameter ARG. */
2097 insert_op1 (op, loc, arg, end)
2103 register unsigned char *pfrom = end;
2104 register unsigned char *pto = end + 3;
2106 while (pfrom != loc)
2109 store_op1 (op, loc, arg);
2113 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2116 insert_op2 (op, loc, arg1, arg2, end)
2122 register unsigned char *pfrom = end;
2123 register unsigned char *pto = end + 5;
2125 while (pfrom != loc)
2128 store_op2 (op, loc, arg1, arg2);
2132 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2133 after an alternative or a begin-subexpression. We assume there is at
2134 least one character before the ^. */
2137 at_begline_loc_p (pattern, p, syntax)
2138 const char *pattern, *p;
2139 reg_syntax_t syntax;
2141 const char *prev = p - 2;
2142 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2145 /* After a subexpression? */
2146 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2147 /* After an alternative? */
2148 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2152 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2153 at least one character after the $, i.e., `P < PEND'. */
2156 at_endline_loc_p (p, pend, syntax)
2157 const char *p, *pend;
2160 const char *next = p;
2161 boolean next_backslash = *next == '\\';
2162 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2165 /* Before a subexpression? */
2166 (syntax & RE_NO_BK_PARENS ? *next == ')'
2167 : next_backslash && next_next && *next_next == ')')
2168 /* Before an alternative? */
2169 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2170 : next_backslash && next_next && *next_next == '|');
2174 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2175 false if it's not. */
2178 group_in_compile_stack (compile_stack, regnum)
2179 compile_stack_type compile_stack;
2184 for (this_element = compile_stack.avail - 1;
2187 if (compile_stack.stack[this_element].regnum == regnum)
2194 /* Read the ending character of a range (in a bracket expression) from the
2195 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2196 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2197 Then we set the translation of all bits between the starting and
2198 ending characters (inclusive) in the compiled pattern B.
2200 Return an error code.
2202 We use these short variable names so we can use the same macros as
2203 `regex_compile' itself. */
2205 static reg_errcode_t
2206 compile_range (p_ptr, pend, translate, syntax, b)
2207 const char **p_ptr, *pend;
2209 reg_syntax_t syntax;
2214 const char *p = *p_ptr;
2215 int range_start, range_end;
2220 /* Even though the pattern is a signed `char *', we need to fetch
2221 with unsigned char *'s; if the high bit of the pattern character
2222 is set, the range endpoints will be negative if we fetch using a
2225 We also want to fetch the endpoints without translating them; the
2226 appropriate translation is done in the bit-setting loop below. */
2227 range_start = ((unsigned char *) p)[-2];
2228 range_end = ((unsigned char *) p)[0];
2230 /* Have to increment the pointer into the pattern string, so the
2231 caller isn't still at the ending character. */
2234 /* If the start is after the end, the range is empty. */
2235 if (range_start > range_end)
2236 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2238 /* Here we see why `this_char' has to be larger than an `unsigned
2239 char' -- the range is inclusive, so if `range_end' == 0xff
2240 (assuming 8-bit characters), we would otherwise go into an infinite
2241 loop, since all characters <= 0xff. */
2242 for (this_char = range_start; this_char <= range_end; this_char++)
2244 SET_LIST_BIT (TRANSLATE (this_char));
2250 /* Failure stack declarations and macros; both re_compile_fastmap and
2251 re_match_2 use a failure stack. These have to be macros because of
2255 /* Number of failure points for which to initially allocate space
2256 when matching. If this number is exceeded, we allocate more
2257 space, so it is not a hard limit. */
2258 #ifndef INIT_FAILURE_ALLOC
2259 #define INIT_FAILURE_ALLOC 5
2262 /* Roughly the maximum number of failure points on the stack. Would be
2263 exactly that if always used MAX_FAILURE_SPACE each time we failed.
2264 This is a variable only so users of regex can assign to it; we never
2265 change it ourselves. */
2266 int re_max_failures = 2000;
2268 typedef const unsigned char *fail_stack_elt_t;
2272 fail_stack_elt_t *stack;
2274 unsigned avail; /* Offset of next open position. */
2277 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
2278 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
2279 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
2280 #define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail])
2283 /* Initialize `fail_stack'. Do `return -2' if the alloc fails. */
2285 #define INIT_FAIL_STACK() \
2287 fail_stack.stack = (fail_stack_elt_t *) \
2288 REGEX_ALLOCATE (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
2290 if (fail_stack.stack == NULL) \
2293 fail_stack.size = INIT_FAILURE_ALLOC; \
2294 fail_stack.avail = 0; \
2298 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
2300 Return 1 if succeeds, and 0 if either ran out of memory
2301 allocating space for it or it was already too large.
2303 REGEX_REALLOCATE requires `destination' be declared. */
2305 #define DOUBLE_FAIL_STACK(fail_stack) \
2306 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
2308 : ((fail_stack).stack = (fail_stack_elt_t *) \
2309 REGEX_REALLOCATE ((fail_stack).stack, \
2310 (fail_stack).size * sizeof (fail_stack_elt_t), \
2311 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
2313 (fail_stack).stack == NULL \
2315 : ((fail_stack).size <<= 1, \
2319 /* Push PATTERN_OP on FAIL_STACK.
2321 Return 1 if was able to do so and 0 if ran out of memory allocating
2323 #define PUSH_PATTERN_OP(pattern_op, fail_stack) \
2324 ((FAIL_STACK_FULL () \
2325 && !DOUBLE_FAIL_STACK (fail_stack)) \
2327 : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \
2330 /* This pushes an item onto the failure stack. Must be a four-byte
2331 value. Assumes the variable `fail_stack'. Probably should only
2332 be called from within `PUSH_FAILURE_POINT'. */
2333 #define PUSH_FAILURE_ITEM(item) \
2334 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) item
2336 /* The complement operation. Assumes `fail_stack' is nonempty. */
2337 #define POP_FAILURE_ITEM() fail_stack.stack[--fail_stack.avail]
2339 /* Used to omit pushing failure point id's when we're not debugging. */
2341 #define DEBUG_PUSH PUSH_FAILURE_ITEM
2342 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_ITEM ()
2344 #define DEBUG_PUSH(item)
2345 #define DEBUG_POP(item_addr)
2349 /* Push the information about the state we will need
2350 if we ever fail back to it.
2352 Requires variables fail_stack, regstart, regend, reg_info, and
2353 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
2356 Does `return FAILURE_CODE' if runs out of memory. */
2358 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
2360 char *destination; \
2361 /* Must be int, so when we don't save any registers, the arithmetic \
2362 of 0 + -1 isn't done as unsigned. */ \
2365 DEBUG_STATEMENT (failure_id++); \
2366 DEBUG_STATEMENT (nfailure_points_pushed++); \
2367 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
2368 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
2369 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
2371 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
2372 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
2374 /* Ensure we have enough space allocated for what we will push. */ \
2375 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
2377 if (!DOUBLE_FAIL_STACK (fail_stack)) \
2378 return failure_code; \
2380 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
2381 (fail_stack).size); \
2382 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
2385 /* Push the info, starting with the registers. */ \
2386 DEBUG_PRINT1 ("\n"); \
2388 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
2391 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
2392 DEBUG_STATEMENT (num_regs_pushed++); \
2394 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2395 PUSH_FAILURE_ITEM (regstart[this_reg]); \
2397 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2398 PUSH_FAILURE_ITEM (regend[this_reg]); \
2400 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
2401 DEBUG_PRINT2 (" match_null=%d", \
2402 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
2403 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
2404 DEBUG_PRINT2 (" matched_something=%d", \
2405 MATCHED_SOMETHING (reg_info[this_reg])); \
2406 DEBUG_PRINT2 (" ever_matched=%d", \
2407 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
2408 DEBUG_PRINT1 ("\n"); \
2409 PUSH_FAILURE_ITEM (reg_info[this_reg].word); \
2412 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
2413 PUSH_FAILURE_ITEM (lowest_active_reg); \
2415 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
2416 PUSH_FAILURE_ITEM (highest_active_reg); \
2418 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
2419 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
2420 PUSH_FAILURE_ITEM (pattern_place); \
2422 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
2423 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
2425 DEBUG_PRINT1 ("'\n"); \
2426 PUSH_FAILURE_ITEM (string_place); \
2428 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
2429 DEBUG_PUSH (failure_id); \
2432 /* This is the number of items that are pushed and popped on the stack
2433 for each register. */
2434 #define NUM_REG_ITEMS 3
2436 /* Individual items aside from the registers. */
2438 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
2440 #define NUM_NONREG_ITEMS 4
2443 /* We push at most this many items on the stack. */
2444 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
2446 /* We actually push this many items. */
2447 #define NUM_FAILURE_ITEMS \
2448 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
2451 /* How many items can still be added to the stack without overflowing it. */
2452 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
2455 /* Pops what PUSH_FAIL_STACK pushes.
2457 We restore into the parameters, all of which should be lvalues:
2458 STR -- the saved data position.
2459 PAT -- the saved pattern position.
2460 LOW_REG, HIGH_REG -- the highest and lowest active registers.
2461 REGSTART, REGEND -- arrays of string positions.
2462 REG_INFO -- array of information about each subexpression.
2464 Also assumes the variables `fail_stack' and (if debugging), `bufp',
2465 `pend', `string1', `size1', `string2', and `size2'. */
2467 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
2469 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
2471 const unsigned char *string_temp; \
2473 assert (!FAIL_STACK_EMPTY ()); \
2475 /* Remove failure points and point to how many regs pushed. */ \
2476 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
2477 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
2478 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
2480 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
2482 DEBUG_POP (&failure_id); \
2483 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
2485 /* If the saved string location is NULL, it came from an \
2486 on_failure_keep_string_jump opcode, and we want to throw away the \
2487 saved NULL, thus retaining our current position in the string. */ \
2488 string_temp = POP_FAILURE_ITEM (); \
2489 if (string_temp != NULL) \
2490 str = (const char *) string_temp; \
2492 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
2493 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
2494 DEBUG_PRINT1 ("'\n"); \
2496 pat = (unsigned char *) POP_FAILURE_ITEM (); \
2497 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
2498 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
2500 /* Restore register info. */ \
2501 high_reg = (unsigned) POP_FAILURE_ITEM (); \
2502 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
2504 low_reg = (unsigned) POP_FAILURE_ITEM (); \
2505 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
2507 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
2509 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
2511 reg_info[this_reg].word = POP_FAILURE_ITEM (); \
2512 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
2514 regend[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2515 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2517 regstart[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2518 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2521 DEBUG_STATEMENT (nfailure_points_popped++); \
2522 } /* POP_FAILURE_POINT */
2524 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2525 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2526 characters can start a string that matches the pattern. This fastmap
2527 is used by re_search to skip quickly over impossible starting points.
2529 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2530 area as BUFP->fastmap.
2532 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2535 Returns 0 if we succeed, -2 if an internal error. */
2538 re_compile_fastmap (bufp)
2539 struct re_pattern_buffer *bufp;
2542 fail_stack_type fail_stack;
2543 #ifndef REGEX_MALLOC
2546 /* We don't push any register information onto the failure stack. */
2547 unsigned num_regs = 0;
2549 register char *fastmap = bufp->fastmap;
2550 unsigned char *pattern = bufp->buffer;
2551 unsigned long size = bufp->used;
2552 const unsigned char *p = pattern;
2553 register unsigned char *pend = pattern + size;
2555 /* Assume that each path through the pattern can be null until
2556 proven otherwise. We set this false at the bottom of switch
2557 statement, to which we get only if a particular path doesn't
2558 match the empty string. */
2559 boolean path_can_be_null = true;
2561 /* We aren't doing a `succeed_n' to begin with. */
2562 boolean succeed_n_p = false;
2564 assert (fastmap != NULL && p != NULL);
2567 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2568 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2569 bufp->can_be_null = 0;
2571 while (p != pend || !FAIL_STACK_EMPTY ())
2575 bufp->can_be_null |= path_can_be_null;
2577 /* Reset for next path. */
2578 path_can_be_null = true;
2580 p = fail_stack.stack[--fail_stack.avail];
2583 /* We should never be about to go beyond the end of the pattern. */
2586 #ifdef SWITCH_ENUM_BUG
2587 switch ((int) ((re_opcode_t) *p++))
2589 switch ((re_opcode_t) *p++)
2593 /* I guess the idea here is to simply not bother with a fastmap
2594 if a backreference is used, since it's too hard to figure out
2595 the fastmap for the corresponding group. Setting
2596 `can_be_null' stops `re_search_2' from using the fastmap, so
2597 that is all we do. */
2599 bufp->can_be_null = 1;
2603 /* Following are the cases which match a character. These end
2612 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2613 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2619 /* Chars beyond end of map must be allowed. */
2620 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2623 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2624 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2630 for (j = 0; j < (1 << BYTEWIDTH); j++)
2631 if (SYNTAX (j) == Sword)
2637 for (j = 0; j < (1 << BYTEWIDTH); j++)
2638 if (SYNTAX (j) != Sword)
2644 /* `.' matches anything ... */
2645 for (j = 0; j < (1 << BYTEWIDTH); j++)
2648 /* ... except perhaps newline. */
2649 if (!(bufp->syntax & RE_DOT_NEWLINE))
2652 /* Return if we have already set `can_be_null'; if we have,
2653 then the fastmap is irrelevant. Something's wrong here. */
2654 else if (bufp->can_be_null)
2657 /* Otherwise, have to check alternative paths. */
2664 for (j = 0; j < (1 << BYTEWIDTH); j++)
2665 if (SYNTAX (j) == (enum syntaxcode) k)
2672 for (j = 0; j < (1 << BYTEWIDTH); j++)
2673 if (SYNTAX (j) != (enum syntaxcode) k)
2678 /* All cases after this match the empty string. These end with
2686 #endif /* not emacs */
2698 case push_dummy_failure:
2703 case pop_failure_jump:
2704 case maybe_pop_jump:
2707 case dummy_failure_jump:
2708 EXTRACT_NUMBER_AND_INCR (j, p);
2713 /* Jump backward implies we just went through the body of a
2714 loop and matched nothing. Opcode jumped to should be
2715 `on_failure_jump' or `succeed_n'. Just treat it like an
2716 ordinary jump. For a * loop, it has pushed its failure
2717 point already; if so, discard that as redundant. */
2718 if ((re_opcode_t) *p != on_failure_jump
2719 && (re_opcode_t) *p != succeed_n)
2723 EXTRACT_NUMBER_AND_INCR (j, p);
2726 /* If what's on the stack is where we are now, pop it. */
2727 if (!FAIL_STACK_EMPTY ()
2728 && fail_stack.stack[fail_stack.avail - 1] == p)
2734 case on_failure_jump:
2735 case on_failure_keep_string_jump:
2736 handle_on_failure_jump:
2737 EXTRACT_NUMBER_AND_INCR (j, p);
2739 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
2740 end of the pattern. We don't want to push such a point,
2741 since when we restore it above, entering the switch will
2742 increment `p' past the end of the pattern. We don't need
2743 to push such a point since we obviously won't find any more
2744 fastmap entries beyond `pend'. Such a pattern can match
2745 the null string, though. */
2748 if (!PUSH_PATTERN_OP (p + j, fail_stack))
2752 bufp->can_be_null = 1;
2756 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
2757 succeed_n_p = false;
2764 /* Get to the number of times to succeed. */
2767 /* Increment p past the n for when k != 0. */
2768 EXTRACT_NUMBER_AND_INCR (k, p);
2772 succeed_n_p = true; /* Spaghetti code alert. */
2773 goto handle_on_failure_jump;
2790 abort (); /* We have listed all the cases. */
2793 /* Getting here means we have found the possible starting
2794 characters for one path of the pattern -- and that the empty
2795 string does not match. We need not follow this path further.
2796 Instead, look at the next alternative (remembered on the
2797 stack), or quit if no more. The test at the top of the loop
2798 does these things. */
2799 path_can_be_null = false;
2803 /* Set `can_be_null' for the last path (also the first path, if the
2804 pattern is empty). */
2805 bufp->can_be_null |= path_can_be_null;
2807 } /* re_compile_fastmap */
2809 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
2810 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
2811 this memory for recording register information. STARTS and ENDS
2812 must be allocated using the malloc library routine, and must each
2813 be at least NUM_REGS * sizeof (regoff_t) bytes long.
2815 If NUM_REGS == 0, then subsequent matches should allocate their own
2818 Unless this function is called, the first search or match using
2819 PATTERN_BUFFER will allocate its own register data, without
2820 freeing the old data. */
2823 re_set_registers (bufp, regs, num_regs, starts, ends)
2824 struct re_pattern_buffer *bufp;
2825 struct re_registers *regs;
2827 regoff_t *starts, *ends;
2831 bufp->regs_allocated = REGS_REALLOCATE;
2832 regs->num_regs = num_regs;
2833 regs->start = starts;
2838 bufp->regs_allocated = REGS_UNALLOCATED;
2840 regs->start = regs->end = (regoff_t) 0;
2844 /* Searching routines. */
2846 /* Like re_search_2, below, but only one string is specified, and
2847 doesn't let you say where to stop matching. */
2850 re_search (bufp, string, size, startpos, range, regs)
2851 struct re_pattern_buffer *bufp;
2853 int size, startpos, range;
2854 struct re_registers *regs;
2856 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
2861 /* Using the compiled pattern in BUFP->buffer, first tries to match the
2862 virtual concatenation of STRING1 and STRING2, starting first at index
2863 STARTPOS, then at STARTPOS + 1, and so on.
2865 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
2867 RANGE is how far to scan while trying to match. RANGE = 0 means try
2868 only at STARTPOS; in general, the last start tried is STARTPOS +
2871 In REGS, return the indices of the virtual concatenation of STRING1
2872 and STRING2 that matched the entire BUFP->buffer and its contained
2875 Do not consider matching one past the index STOP in the virtual
2876 concatenation of STRING1 and STRING2.
2878 We return either the position in the strings at which the match was
2879 found, -1 if no match, or -2 if error (such as failure
2883 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
2884 struct re_pattern_buffer *bufp;
2885 const char *string1, *string2;
2889 struct re_registers *regs;
2893 register char *fastmap = bufp->fastmap;
2894 register char *translate = bufp->translate;
2895 int total_size = size1 + size2;
2896 int endpos = startpos + range;
2898 /* Check for out-of-range STARTPOS. */
2899 if (startpos < 0 || startpos > total_size)
2902 /* Fix up RANGE if it might eventually take us outside
2903 the virtual concatenation of STRING1 and STRING2. */
2905 range = -1 - startpos;
2906 else if (endpos > total_size)
2907 range = total_size - startpos;
2909 /* If the search isn't to be a backwards one, don't waste time in a
2910 search for a pattern that must be anchored. */
2911 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
2919 /* Update the fastmap now if not correct already. */
2920 if (fastmap && !bufp->fastmap_accurate)
2921 if (re_compile_fastmap (bufp) == -2)
2924 /* Loop through the string, looking for a place to start matching. */
2927 /* If a fastmap is supplied, skip quickly over characters that
2928 cannot be the start of a match. If the pattern can match the
2929 null string, however, we don't need to skip characters; we want
2930 the first null string. */
2931 if (fastmap && startpos < total_size && !bufp->can_be_null)
2933 if (range > 0) /* Searching forwards. */
2935 register const char *d;
2936 register int lim = 0;
2939 if (startpos < size1 && startpos + range >= size1)
2940 lim = range - (size1 - startpos);
2942 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
2944 /* Written out as an if-else to avoid testing `translate'
2948 && !fastmap[(unsigned char)
2949 translate[(unsigned char) *d++]])
2952 while (range > lim && !fastmap[(unsigned char) *d++])
2955 startpos += irange - range;
2957 else /* Searching backwards. */
2959 register char c = (size1 == 0 || startpos >= size1
2960 ? string2[startpos - size1]
2961 : string1[startpos]);
2963 if (!fastmap[(unsigned char) TRANSLATE (c)])
2968 /* If can't match the null string, and that's all we have left, fail. */
2969 if (range >= 0 && startpos == total_size && fastmap
2970 && !bufp->can_be_null)
2973 val = re_match_2 (bufp, string1, size1, string2, size2,
2974 startpos, regs, stop);
2998 /* Declarations and macros for re_match_2. */
3000 static int bcmp_translate ();
3001 static boolean alt_match_null_string_p (),
3002 common_op_match_null_string_p (),
3003 group_match_null_string_p ();
3005 /* Structure for per-register (a.k.a. per-group) information.
3006 This must not be longer than one word, because we push this value
3007 onto the failure stack. Other register information, such as the
3008 starting and ending positions (which are addresses), and the list of
3009 inner groups (which is a bits list) are maintained in separate
3012 We are making a (strictly speaking) nonportable assumption here: that
3013 the compiler will pack our bit fields into something that fits into
3014 the type of `word', i.e., is something that fits into one item on the
3018 fail_stack_elt_t word;
3021 /* This field is one if this group can match the empty string,
3022 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
3023 #define MATCH_NULL_UNSET_VALUE 3
3024 unsigned match_null_string_p : 2;
3025 unsigned is_active : 1;
3026 unsigned matched_something : 1;
3027 unsigned ever_matched_something : 1;
3029 } register_info_type;
3031 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
3032 #define IS_ACTIVE(R) ((R).bits.is_active)
3033 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
3034 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
3037 /* Call this when have matched a real character; it sets `matched' flags
3038 for the subexpressions which we are currently inside. Also records
3039 that those subexprs have matched. */
3040 #define SET_REGS_MATCHED() \
3044 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
3046 MATCHED_SOMETHING (reg_info[r]) \
3047 = EVER_MATCHED_SOMETHING (reg_info[r]) \
3054 /* This converts PTR, a pointer into one of the search strings `string1'
3055 and `string2' into an offset from the beginning of that string. */
3056 #define POINTER_TO_OFFSET(ptr) \
3057 (FIRST_STRING_P (ptr) ? (ptr) - string1 : (ptr) - string2 + size1)
3059 /* Registers are set to a sentinel when they haven't yet matched. */
3060 #define REG_UNSET_VALUE ((char *) -1)
3061 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
3064 /* Macros for dealing with the split strings in re_match_2. */
3066 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3068 /* Call before fetching a character with *d. This switches over to
3069 string2 if necessary. */
3070 #define PREFETCH() \
3073 /* End of string2 => fail. */ \
3074 if (dend == end_match_2) \
3076 /* End of string1 => advance to string2. */ \
3078 dend = end_match_2; \
3082 /* Test if at very beginning or at very end of the virtual concatenation
3083 of `string1' and `string2'. If only one string, it's `string2'. */
3084 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3085 #define AT_STRINGS_END(d) ((d) == end2)
3088 /* Test if D points to a character which is word-constituent. We have
3089 two special cases to check for: if past the end of string1, look at
3090 the first character in string2; and if before the beginning of
3091 string2, look at the last character in string1. */
3092 #define WORDCHAR_P(d) \
3093 (SYNTAX ((d) == end1 ? *string2 \
3094 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3097 /* Test if the character before D and the one at D differ with respect
3098 to being word-constituent. */
3099 #define AT_WORD_BOUNDARY(d) \
3100 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3101 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3104 /* Free everything we malloc. */
3106 #define FREE_VAR(var) if (var) free (var); var = NULL
3107 #define FREE_VARIABLES() \
3109 FREE_VAR (fail_stack.stack); \
3110 FREE_VAR (regstart); \
3111 FREE_VAR (regend); \
3112 FREE_VAR (old_regstart); \
3113 FREE_VAR (old_regend); \
3114 FREE_VAR (best_regstart); \
3115 FREE_VAR (best_regend); \
3116 FREE_VAR (reg_info); \
3117 FREE_VAR (reg_dummy); \
3118 FREE_VAR (reg_info_dummy); \
3120 #else /* not REGEX_MALLOC */
3121 /* Some MIPS systems (at least) want this to free alloca'd storage. */
3122 #define FREE_VARIABLES() alloca (0)
3123 #endif /* not REGEX_MALLOC */
3126 /* These values must meet several constraints. They must not be valid
3127 register values; since we have a limit of 255 registers (because
3128 we use only one byte in the pattern for the register number), we can
3129 use numbers larger than 255. They must differ by 1, because of
3130 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3131 be larger than the value for the highest register, so we do not try
3132 to actually save any registers when none are active. */
3133 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3134 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3136 /* Matching routines. */
3138 #ifndef emacs /* Emacs never uses this. */
3139 /* re_match is like re_match_2 except it takes only a single string. */
3142 re_match (bufp, string, size, pos, regs)
3143 struct re_pattern_buffer *bufp;
3146 struct re_registers *regs;
3148 return re_match_2 (bufp, NULL, 0, string, size, pos, regs, size);
3150 #endif /* not emacs */
3153 /* re_match_2 matches the compiled pattern in BUFP against the
3154 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3155 and SIZE2, respectively). We start matching at POS, and stop
3158 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3159 store offsets for the substring each group matched in REGS. See the
3160 documentation for exactly how many groups we fill.
3162 We return -1 if no match, -2 if an internal error (such as the
3163 failure stack overflowing). Otherwise, we return the length of the
3164 matched substring. */
3167 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3168 struct re_pattern_buffer *bufp;
3169 const char *string1, *string2;
3172 struct re_registers *regs;
3175 /* General temporaries. */
3179 /* Just past the end of the corresponding string. */
3180 const char *end1, *end2;
3182 /* Pointers into string1 and string2, just past the last characters in
3183 each to consider matching. */
3184 const char *end_match_1, *end_match_2;
3186 /* Where we are in the data, and the end of the current string. */
3187 const char *d, *dend;
3189 /* Where we are in the pattern, and the end of the pattern. */
3190 unsigned char *p = bufp->buffer;
3191 register unsigned char *pend = p + bufp->used;
3193 /* We use this to map every character in the string. */
3194 char *translate = bufp->translate;
3196 /* Failure point stack. Each place that can handle a failure further
3197 down the line pushes a failure point on this stack. It consists of
3198 restart, regend, and reg_info for all registers corresponding to
3199 the subexpressions we're currently inside, plus the number of such
3200 registers, and, finally, two char *'s. The first char * is where
3201 to resume scanning the pattern; the second one is where to resume
3202 scanning the strings. If the latter is zero, the failure point is
3203 a ``dummy''; if a failure happens and the failure point is a dummy,
3204 it gets discarded and the next next one is tried. */
3205 fail_stack_type fail_stack;
3207 static unsigned failure_id = 0;
3208 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3211 /* We fill all the registers internally, independent of what we
3212 return, for use in backreferences. The number here includes
3213 an element for register zero. */
3214 unsigned num_regs = bufp->re_nsub + 1;
3216 /* The currently active registers. */
3217 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3218 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3220 /* Information on the contents of registers. These are pointers into
3221 the input strings; they record just what was matched (on this
3222 attempt) by a subexpression part of the pattern, that is, the
3223 regnum-th regstart pointer points to where in the pattern we began
3224 matching and the regnum-th regend points to right after where we
3225 stopped matching the regnum-th subexpression. (The zeroth register
3226 keeps track of what the whole pattern matches.) */
3227 const char **regstart = NULL, **regend = NULL;
3229 /* If a group that's operated upon by a repetition operator fails to
3230 match anything, then the register for its start will need to be
3231 restored because it will have been set to wherever in the string we
3232 are when we last see its open-group operator. Similarly for a
3234 const char **old_regstart = NULL, **old_regend = NULL;
3236 /* The is_active field of reg_info helps us keep track of which (possibly
3237 nested) subexpressions we are currently in. The matched_something
3238 field of reg_info[reg_num] helps us tell whether or not we have
3239 matched any of the pattern so far this time through the reg_num-th
3240 subexpression. These two fields get reset each time through any
3241 loop their register is in. */
3242 register_info_type *reg_info = NULL;
3244 /* The following record the register info as found in the above
3245 variables when we find a match better than any we've seen before.
3246 This happens as we backtrack through the failure points, which in
3247 turn happens only if we have not yet matched the entire string. */
3248 unsigned best_regs_set = false;
3249 const char **best_regstart = NULL, **best_regend = NULL;
3251 /* Logically, this is `best_regend[0]'. But we don't want to have to
3252 allocate space for that if we're not allocating space for anything
3253 else (see below). Also, we never need info about register 0 for
3254 any of the other register vectors, and it seems rather a kludge to
3255 treat `best_regend' differently than the rest. So we keep track of
3256 the end of the best match so far in a separate variable. We
3257 initialize this to NULL so that when we backtrack the first time
3258 and need to test it, it's not garbage. */
3259 const char *match_end = NULL;
3261 /* Used when we pop values we don't care about. */
3262 const char **reg_dummy = NULL;
3263 register_info_type *reg_info_dummy = NULL;
3266 /* Counts the total number of registers pushed. */
3267 unsigned num_regs_pushed = 0;
3270 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3274 /* Do not bother to initialize all the register variables if there are
3275 no groups in the pattern, as it takes a fair amount of time. If
3276 there are groups, we include space for register 0 (the whole
3277 pattern), even though we never use it, since it simplifies the
3278 array indexing. We should fix this. */
3281 regstart = REGEX_TALLOC (num_regs, const char *);
3282 regend = REGEX_TALLOC (num_regs, const char *);
3283 old_regstart = REGEX_TALLOC (num_regs, const char *);
3284 old_regend = REGEX_TALLOC (num_regs, const char *);
3285 best_regstart = REGEX_TALLOC (num_regs, const char *);
3286 best_regend = REGEX_TALLOC (num_regs, const char *);
3287 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3288 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3289 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3291 if (!(regstart && regend && old_regstart && old_regend && reg_info
3292 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3301 /* We must initialize all our variables to NULL, so that
3302 `FREE_VARIABLES' doesn't try to free them. */
3303 regstart = regend = old_regstart = old_regend = best_regstart
3304 = best_regend = reg_dummy = NULL;
3305 reg_info = reg_info_dummy = (register_info_type *) NULL;
3307 #endif /* REGEX_MALLOC */
3309 /* The starting position is bogus. */
3310 if (pos < 0 || pos > size1 + size2)
3316 /* Initialize subexpression text positions to -1 to mark ones that no
3317 start_memory/stop_memory has been seen for. Also initialize the
3318 register information struct. */
3319 for (mcnt = 1; mcnt < num_regs; mcnt++)
3321 regstart[mcnt] = regend[mcnt]
3322 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3324 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3325 IS_ACTIVE (reg_info[mcnt]) = 0;
3326 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3327 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3330 /* We move `string1' into `string2' if the latter's empty -- but not if
3331 `string1' is null. */
3332 if (size2 == 0 && string1 != NULL)
3339 end1 = string1 + size1;
3340 end2 = string2 + size2;
3342 /* Compute where to stop matching, within the two strings. */
3345 end_match_1 = string1 + stop;
3346 end_match_2 = string2;
3351 end_match_2 = string2 + stop - size1;
3354 /* `p' scans through the pattern as `d' scans through the data.
3355 `dend' is the end of the input string that `d' points within. `d'
3356 is advanced into the following input string whenever necessary, but
3357 this happens before fetching; therefore, at the beginning of the
3358 loop, `d' can be pointing at the end of a string, but it cannot
3360 if (size1 > 0 && pos <= size1)
3367 d = string2 + pos - size1;
3371 DEBUG_PRINT1 ("The compiled pattern is: ");
3372 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3373 DEBUG_PRINT1 ("The string to match is: `");
3374 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3375 DEBUG_PRINT1 ("'\n");
3377 /* This loops over pattern commands. It exits by returning from the
3378 function if the match is complete, or it drops through if the match
3379 fails at this starting point in the input data. */
3382 DEBUG_PRINT2 ("\n0x%x: ", p);
3385 { /* End of pattern means we might have succeeded. */
3386 DEBUG_PRINT1 ("end of pattern ... ");
3388 /* If we haven't matched the entire string, and we want the
3389 longest match, try backtracking. */
3390 if (d != end_match_2)
3392 DEBUG_PRINT1 ("backtracking.\n");
3394 if (!FAIL_STACK_EMPTY ())
3395 { /* More failure points to try. */
3396 boolean same_str_p = (FIRST_STRING_P (match_end)
3397 == MATCHING_IN_FIRST_STRING);
3399 /* If exceeds best match so far, save it. */
3401 || (same_str_p && d > match_end)
3402 || (!same_str_p && !MATCHING_IN_FIRST_STRING))
3404 best_regs_set = true;
3407 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3409 for (mcnt = 1; mcnt < num_regs; mcnt++)
3411 best_regstart[mcnt] = regstart[mcnt];
3412 best_regend[mcnt] = regend[mcnt];
3418 /* If no failure points, don't restore garbage. */
3419 else if (best_regs_set)
3422 /* Restore best match. It may happen that `dend ==
3423 end_match_1' while the restored d is in string2.
3424 For example, the pattern `x.*y.*z' against the
3425 strings `x-' and `y-z-', if the two strings are
3426 not consecutive in memory. */
3427 DEBUG_PRINT1 ("Restoring best registers.\n");
3430 dend = ((d >= string1 && d <= end1)
3431 ? end_match_1 : end_match_2);
3433 for (mcnt = 1; mcnt < num_regs; mcnt++)
3435 regstart[mcnt] = best_regstart[mcnt];
3436 regend[mcnt] = best_regend[mcnt];
3439 } /* d != end_match_2 */
3441 DEBUG_PRINT1 ("Accepting match.\n");
3443 /* If caller wants register contents data back, do it. */
3444 if (regs && !bufp->no_sub)
3446 /* Have the register data arrays been allocated? */
3447 if (bufp->regs_allocated == REGS_UNALLOCATED)
3448 { /* No. So allocate them with malloc. We need one
3449 extra element beyond `num_regs' for the `-1' marker
3451 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3452 regs->start = TALLOC (regs->num_regs, regoff_t);
3453 regs->end = TALLOC (regs->num_regs, regoff_t);
3454 if (regs->start == NULL || regs->end == NULL)
3456 bufp->regs_allocated = REGS_REALLOCATE;
3458 else if (bufp->regs_allocated == REGS_REALLOCATE)
3459 { /* Yes. If we need more elements than were already
3460 allocated, reallocate them. If we need fewer, just
3462 if (regs->num_regs < num_regs + 1)
3464 regs->num_regs = num_regs + 1;
3465 RETALLOC (regs->start, regs->num_regs, regoff_t);
3466 RETALLOC (regs->end, regs->num_regs, regoff_t);
3467 if (regs->start == NULL || regs->end == NULL)
3472 assert (bufp->regs_allocated == REGS_FIXED);
3474 /* Convert the pointer data in `regstart' and `regend' to
3475 indices. Register zero has to be set differently,
3476 since we haven't kept track of any info for it. */
3477 if (regs->num_regs > 0)
3479 regs->start[0] = pos;
3480 regs->end[0] = (MATCHING_IN_FIRST_STRING ? d - string1
3481 : d - string2 + size1);
3484 /* Go through the first `min (num_regs, regs->num_regs)'
3485 registers, since that is all we initialized. */
3486 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3488 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3489 regs->start[mcnt] = regs->end[mcnt] = -1;
3492 regs->start[mcnt] = POINTER_TO_OFFSET (regstart[mcnt]);
3493 regs->end[mcnt] = POINTER_TO_OFFSET (regend[mcnt]);
3497 /* If the regs structure we return has more elements than
3498 were in the pattern, set the extra elements to -1. If
3499 we (re)allocated the registers, this is the case,
3500 because we always allocate enough to have at least one
3502 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3503 regs->start[mcnt] = regs->end[mcnt] = -1;
3504 } /* regs && !bufp->no_sub */
3507 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3508 nfailure_points_pushed, nfailure_points_popped,
3509 nfailure_points_pushed - nfailure_points_popped);
3510 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3512 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3516 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3521 /* Otherwise match next pattern command. */
3522 #ifdef SWITCH_ENUM_BUG
3523 switch ((int) ((re_opcode_t) *p++))
3525 switch ((re_opcode_t) *p++)
3528 /* Ignore these. Used to ignore the n of succeed_n's which
3529 currently have n == 0. */
3531 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3535 /* Match the next n pattern characters exactly. The following
3536 byte in the pattern defines n, and the n bytes after that
3537 are the characters to match. */
3540 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3542 /* This is written out as an if-else so we don't waste time
3543 testing `translate' inside the loop. */
3549 if (translate[(unsigned char) *d++] != (char) *p++)
3559 if (*d++ != (char) *p++) goto fail;
3563 SET_REGS_MATCHED ();
3567 /* Match any character except possibly a newline or a null. */
3569 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3573 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3574 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3577 SET_REGS_MATCHED ();
3578 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3586 register unsigned char c;
3587 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3589 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3592 c = TRANSLATE (*d); /* The character to match. */
3594 /* Cast to `unsigned' instead of `unsigned char' in case the
3595 bit list is a full 32 bytes long. */
3596 if (c < (unsigned) (*p * BYTEWIDTH)
3597 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3602 if (!not) goto fail;
3604 SET_REGS_MATCHED ();
3610 /* The beginning of a group is represented by start_memory.
3611 The arguments are the register number in the next byte, and the
3612 number of groups inner to this one in the next. The text
3613 matched within the group is recorded (in the internal
3614 registers data structure) under the register number. */
3616 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3618 /* Find out if this group can match the empty string. */
3619 p1 = p; /* To send to group_match_null_string_p. */
3621 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3622 REG_MATCH_NULL_STRING_P (reg_info[*p])
3623 = group_match_null_string_p (&p1, pend, reg_info);
3625 /* Save the position in the string where we were the last time
3626 we were at this open-group operator in case the group is
3627 operated upon by a repetition operator, e.g., with `(a*)*b'
3628 against `ab'; then we want to ignore where we are now in
3629 the string in case this attempt to match fails. */
3630 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3631 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3633 DEBUG_PRINT2 (" old_regstart: %d\n",
3634 POINTER_TO_OFFSET (old_regstart[*p]));
3637 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
3639 IS_ACTIVE (reg_info[*p]) = 1;
3640 MATCHED_SOMETHING (reg_info[*p]) = 0;
3642 /* This is the new highest active register. */
3643 highest_active_reg = *p;
3645 /* If nothing was active before, this is the new lowest active
3647 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3648 lowest_active_reg = *p;
3650 /* Move past the register number and inner group count. */
3655 /* The stop_memory opcode represents the end of a group. Its
3656 arguments are the same as start_memory's: the register
3657 number, and the number of inner groups. */
3659 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
3661 /* We need to save the string position the last time we were at
3662 this close-group operator in case the group is operated
3663 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
3664 against `aba'; then we want to ignore where we are now in
3665 the string in case this attempt to match fails. */
3666 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3667 ? REG_UNSET (regend[*p]) ? d : regend[*p]
3669 DEBUG_PRINT2 (" old_regend: %d\n",
3670 POINTER_TO_OFFSET (old_regend[*p]));
3673 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
3675 /* This register isn't active anymore. */
3676 IS_ACTIVE (reg_info[*p]) = 0;
3678 /* If this was the only register active, nothing is active
3680 if (lowest_active_reg == highest_active_reg)
3682 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3683 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3686 { /* We must scan for the new highest active register, since
3687 it isn't necessarily one less than now: consider
3688 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
3689 new highest active register is 1. */
3690 unsigned char r = *p - 1;
3691 while (r > 0 && !IS_ACTIVE (reg_info[r]))
3694 /* If we end up at register zero, that means that we saved
3695 the registers as the result of an `on_failure_jump', not
3696 a `start_memory', and we jumped to past the innermost
3697 `stop_memory'. For example, in ((.)*) we save
3698 registers 1 and 2 as a result of the *, but when we pop
3699 back to the second ), we are at the stop_memory 1.
3700 Thus, nothing is active. */
3703 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3704 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3707 highest_active_reg = r;
3710 /* If just failed to match something this time around with a
3711 group that's operated on by a repetition operator, try to
3712 force exit from the ``loop'', and restore the register
3713 information for this group that we had before trying this
3715 if ((!MATCHED_SOMETHING (reg_info[*p])
3716 || (re_opcode_t) p[-3] == start_memory)
3719 boolean is_a_jump_n = false;
3723 switch ((re_opcode_t) *p1++)
3727 case pop_failure_jump:
3728 case maybe_pop_jump:
3730 case dummy_failure_jump:
3731 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3741 /* If the next operation is a jump backwards in the pattern
3742 to an on_failure_jump right before the start_memory
3743 corresponding to this stop_memory, exit from the loop
3744 by forcing a failure after pushing on the stack the
3745 on_failure_jump's jump in the pattern, and d. */
3746 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
3747 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
3749 /* If this group ever matched anything, then restore
3750 what its registers were before trying this last
3751 failed match, e.g., with `(a*)*b' against `ab' for
3752 regstart[1], and, e.g., with `((a*)*(b*)*)*'
3753 against `aba' for regend[3].
3755 Also restore the registers for inner groups for,
3756 e.g., `((a*)(b*))*' against `aba' (register 3 would
3757 otherwise get trashed). */
3759 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
3763 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
3765 /* Restore this and inner groups' (if any) registers. */
3766 for (r = *p; r < *p + *(p + 1); r++)
3768 regstart[r] = old_regstart[r];
3770 /* xx why this test? */
3771 if ((int) old_regend[r] >= (int) regstart[r])
3772 regend[r] = old_regend[r];
3776 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3777 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
3783 /* Move past the register number and the inner group count. */
3788 /* \<digit> has been turned into a `duplicate' command which is
3789 followed by the numeric value of <digit> as the register number. */
3792 register const char *d2, *dend2;
3793 int regno = *p++; /* Get which register to match against. */
3794 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
3796 /* Can't back reference a group which we've never matched. */
3797 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
3800 /* Where in input to try to start matching. */
3801 d2 = regstart[regno];
3803 /* Where to stop matching; if both the place to start and
3804 the place to stop matching are in the same string, then
3805 set to the place to stop, otherwise, for now have to use
3806 the end of the first string. */
3808 dend2 = ((FIRST_STRING_P (regstart[regno])
3809 == FIRST_STRING_P (regend[regno]))
3810 ? regend[regno] : end_match_1);
3813 /* If necessary, advance to next segment in register
3817 if (dend2 == end_match_2) break;
3818 if (dend2 == regend[regno]) break;
3820 /* End of string1 => advance to string2. */
3822 dend2 = regend[regno];
3824 /* At end of register contents => success */
3825 if (d2 == dend2) break;
3827 /* If necessary, advance to next segment in data. */
3830 /* How many characters left in this segment to match. */
3833 /* Want how many consecutive characters we can match in
3834 one shot, so, if necessary, adjust the count. */
3835 if (mcnt > dend2 - d2)
3838 /* Compare that many; failure if mismatch, else move
3841 ? bcmp_translate (d, d2, mcnt, translate)
3842 : bcmp (d, d2, mcnt))
3844 d += mcnt, d2 += mcnt;
3850 /* begline matches the empty string at the beginning of the string
3851 (unless `not_bol' is set in `bufp'), and, if
3852 `newline_anchor' is set, after newlines. */
3854 DEBUG_PRINT1 ("EXECUTING begline.\n");
3856 if (AT_STRINGS_BEG (d))
3858 if (!bufp->not_bol) break;
3860 else if (d[-1] == '\n' && bufp->newline_anchor)
3864 /* In all other cases, we fail. */
3868 /* endline is the dual of begline. */
3870 DEBUG_PRINT1 ("EXECUTING endline.\n");
3872 if (AT_STRINGS_END (d))
3874 if (!bufp->not_eol) break;
3877 /* We have to ``prefetch'' the next character. */
3878 else if ((d == end1 ? *string2 : *d) == '\n'
3879 && bufp->newline_anchor)
3886 /* Match at the very beginning of the data. */
3888 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
3889 if (AT_STRINGS_BEG (d))
3894 /* Match at the very end of the data. */
3896 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
3897 if (AT_STRINGS_END (d))
3902 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
3903 pushes NULL as the value for the string on the stack. Then
3904 `pop_failure_point' will keep the current value for the
3905 string, instead of restoring it. To see why, consider
3906 matching `foo\nbar' against `.*\n'. The .* matches the foo;
3907 then the . fails against the \n. But the next thing we want
3908 to do is match the \n against the \n; if we restored the
3909 string value, we would be back at the foo.
3911 Because this is used only in specific cases, we don't need to
3912 check all the things that `on_failure_jump' does, to make
3913 sure the right things get saved on the stack. Hence we don't
3914 share its code. The only reason to push anything on the
3915 stack at all is that otherwise we would have to change
3916 `anychar's code to do something besides goto fail in this
3917 case; that seems worse than this. */
3918 case on_failure_keep_string_jump:
3919 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
3921 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3922 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
3924 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
3928 /* Uses of on_failure_jump:
3930 Each alternative starts with an on_failure_jump that points
3931 to the beginning of the next alternative. Each alternative
3932 except the last ends with a jump that in effect jumps past
3933 the rest of the alternatives. (They really jump to the
3934 ending jump of the following alternative, because tensioning
3935 these jumps is a hassle.)
3937 Repeats start with an on_failure_jump that points past both
3938 the repetition text and either the following jump or
3939 pop_failure_jump back to this on_failure_jump. */
3940 case on_failure_jump:
3942 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
3944 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3945 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
3947 /* If this on_failure_jump comes right before a group (i.e.,
3948 the original * applied to a group), save the information
3949 for that group and all inner ones, so that if we fail back
3950 to this point, the group's information will be correct.
3951 For example, in \(a*\)*\1, we need the preceding group,
3952 and in \(\(a*\)b*\)\2, we need the inner group. */
3954 /* We can't use `p' to check ahead because we push
3955 a failure point to `p + mcnt' after we do this. */
3958 /* We need to skip no_op's before we look for the
3959 start_memory in case this on_failure_jump is happening as
3960 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
3962 while (p1 < pend && (re_opcode_t) *p1 == no_op)
3965 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
3967 /* We have a new highest active register now. This will
3968 get reset at the start_memory we are about to get to,
3969 but we will have saved all the registers relevant to
3970 this repetition op, as described above. */
3971 highest_active_reg = *(p1 + 1) + *(p1 + 2);
3972 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3973 lowest_active_reg = *(p1 + 1);
3976 DEBUG_PRINT1 (":\n");
3977 PUSH_FAILURE_POINT (p + mcnt, d, -2);
3981 /* A smart repeat ends with `maybe_pop_jump'.
3982 We change it to either `pop_failure_jump' or `jump'. */
3983 case maybe_pop_jump:
3984 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3985 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
3987 register unsigned char *p2 = p;
3989 /* Compare the beginning of the repeat with what in the
3990 pattern follows its end. If we can establish that there
3991 is nothing that they would both match, i.e., that we
3992 would have to backtrack because of (as in, e.g., `a*a')
3993 then we can change to pop_failure_jump, because we'll
3994 never have to backtrack.
3996 This is not true in the case of alternatives: in
3997 `(a|ab)*' we do need to backtrack to the `ab' alternative
3998 (e.g., if the string was `ab'). But instead of trying to
3999 detect that here, the alternative has put on a dummy
4000 failure point which is what we will end up popping. */
4002 /* Skip over open/close-group commands. */
4003 while (p2 + 2 < pend
4004 && ((re_opcode_t) *p2 == stop_memory
4005 || (re_opcode_t) *p2 == start_memory))
4006 p2 += 3; /* Skip over args, too. */
4008 /* If we're at the end of the pattern, we can change. */
4011 /* Consider what happens when matching ":\(.*\)"
4012 against ":/". I don't really understand this code
4014 p[-3] = (unsigned char) pop_failure_jump;
4016 (" End of pattern: change to `pop_failure_jump'.\n");
4019 else if ((re_opcode_t) *p2 == exactn
4020 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
4022 register unsigned char c
4023 = *p2 == (unsigned char) endline ? '\n' : p2[2];
4026 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
4027 to the `maybe_finalize_jump' of this case. Examine what
4029 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
4031 p[-3] = (unsigned char) pop_failure_jump;
4032 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4036 else if ((re_opcode_t) p1[3] == charset
4037 || (re_opcode_t) p1[3] == charset_not)
4039 int not = (re_opcode_t) p1[3] == charset_not;
4041 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4042 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4045 /* `not' is equal to 1 if c would match, which means
4046 that we can't change to pop_failure_jump. */
4049 p[-3] = (unsigned char) pop_failure_jump;
4050 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4055 p -= 2; /* Point at relative address again. */
4056 if ((re_opcode_t) p[-1] != pop_failure_jump)
4058 p[-1] = (unsigned char) jump;
4059 DEBUG_PRINT1 (" Match => jump.\n");
4060 goto unconditional_jump;
4062 /* Note fall through. */
4065 /* The end of a simple repeat has a pop_failure_jump back to
4066 its matching on_failure_jump, where the latter will push a
4067 failure point. The pop_failure_jump takes off failure
4068 points put on by this pop_failure_jump's matching
4069 on_failure_jump; we got through the pattern to here from the
4070 matching on_failure_jump, so didn't fail. */
4071 case pop_failure_jump:
4073 /* We need to pass separate storage for the lowest and
4074 highest registers, even though we don't care about the
4075 actual values. Otherwise, we will restore only one
4076 register from the stack, since lowest will == highest in
4077 `pop_failure_point'. */
4078 unsigned dummy_low_reg, dummy_high_reg;
4079 unsigned char *pdummy;
4082 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4083 POP_FAILURE_POINT (sdummy, pdummy,
4084 dummy_low_reg, dummy_high_reg,
4085 reg_dummy, reg_dummy, reg_info_dummy);
4087 /* Note fall through. */
4090 /* Unconditionally jump (without popping any failure points). */
4093 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4094 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4095 p += mcnt; /* Do the jump. */
4096 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4100 /* We need this opcode so we can detect where alternatives end
4101 in `group_match_null_string_p' et al. */
4103 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4104 goto unconditional_jump;
4107 /* Normally, the on_failure_jump pushes a failure point, which
4108 then gets popped at pop_failure_jump. We will end up at
4109 pop_failure_jump, also, and with a pattern of, say, `a+', we
4110 are skipping over the on_failure_jump, so we have to push
4111 something meaningless for pop_failure_jump to pop. */
4112 case dummy_failure_jump:
4113 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4114 /* It doesn't matter what we push for the string here. What
4115 the code at `fail' tests is the value for the pattern. */
4116 PUSH_FAILURE_POINT (0, 0, -2);
4117 goto unconditional_jump;
4120 /* At the end of an alternative, we need to push a dummy failure
4121 point in case we are followed by a `pop_failure_jump', because
4122 we don't want the failure point for the alternative to be
4123 popped. For example, matching `(a|ab)*' against `aab'
4124 requires that we match the `ab' alternative. */
4125 case push_dummy_failure:
4126 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4127 /* See comments just above at `dummy_failure_jump' about the
4129 PUSH_FAILURE_POINT (0, 0, -2);
4132 /* Have to succeed matching what follows at least n times.
4133 After that, handle like `on_failure_jump'. */
4135 EXTRACT_NUMBER (mcnt, p + 2);
4136 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4139 /* Originally, this is how many times we HAVE to succeed. */
4144 STORE_NUMBER_AND_INCR (p, mcnt);
4145 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4149 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4150 p[2] = (unsigned char) no_op;
4151 p[3] = (unsigned char) no_op;
4157 EXTRACT_NUMBER (mcnt, p + 2);
4158 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4160 /* Originally, this is how many times we CAN jump. */
4164 STORE_NUMBER (p + 2, mcnt);
4165 goto unconditional_jump;
4167 /* If don't have to jump any more, skip over the rest of command. */
4174 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4176 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4178 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4179 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4180 STORE_NUMBER (p1, mcnt);
4185 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4186 if (AT_WORD_BOUNDARY (d))
4191 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4192 if (AT_WORD_BOUNDARY (d))
4197 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4198 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4203 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4204 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4205 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4212 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4213 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4218 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4219 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4224 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4225 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4228 #else /* not emacs19 */
4230 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4231 if (PTR_CHAR_POS ((unsigned char *) d) + 1 != point)
4234 #endif /* not emacs19 */
4237 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4242 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4246 if (SYNTAX (*d++) != (enum syntaxcode) mcnt)
4248 SET_REGS_MATCHED ();
4252 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4254 goto matchnotsyntax;
4257 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4261 if (SYNTAX (*d++) == (enum syntaxcode) mcnt)
4263 SET_REGS_MATCHED ();
4266 #else /* not emacs */
4268 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4270 if (!WORDCHAR_P (d))
4272 SET_REGS_MATCHED ();
4277 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4281 SET_REGS_MATCHED ();
4284 #endif /* not emacs */
4289 continue; /* Successfully executed one pattern command; keep going. */
4292 /* We goto here if a matching operation fails. */
4294 if (!FAIL_STACK_EMPTY ())
4295 { /* A restart point is known. Restore to that state. */
4296 DEBUG_PRINT1 ("\nFAIL:\n");
4297 POP_FAILURE_POINT (d, p,
4298 lowest_active_reg, highest_active_reg,
4299 regstart, regend, reg_info);
4301 /* If this failure point is a dummy, try the next one. */
4305 /* If we failed to the end of the pattern, don't examine *p. */
4309 boolean is_a_jump_n = false;
4311 /* If failed to a backwards jump that's part of a repetition
4312 loop, need to pop this failure point and use the next one. */
4313 switch ((re_opcode_t) *p)
4317 case maybe_pop_jump:
4318 case pop_failure_jump:
4321 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4324 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4326 && (re_opcode_t) *p1 == on_failure_jump))
4334 if (d >= string1 && d <= end1)
4338 break; /* Matching at this starting point really fails. */
4342 goto restore_best_regs;
4346 return -1; /* Failure to match. */
4349 /* Subroutine definitions for re_match_2. */
4352 /* We are passed P pointing to a register number after a start_memory.
4354 Return true if the pattern up to the corresponding stop_memory can
4355 match the empty string, and false otherwise.
4357 If we find the matching stop_memory, sets P to point to one past its number.
4358 Otherwise, sets P to an undefined byte less than or equal to END.
4360 We don't handle duplicates properly (yet). */
4363 group_match_null_string_p (p, end, reg_info)
4364 unsigned char **p, *end;
4365 register_info_type *reg_info;
4368 /* Point to after the args to the start_memory. */
4369 unsigned char *p1 = *p + 2;
4373 /* Skip over opcodes that can match nothing, and return true or
4374 false, as appropriate, when we get to one that can't, or to the
4375 matching stop_memory. */
4377 switch ((re_opcode_t) *p1)
4379 /* Could be either a loop or a series of alternatives. */
4380 case on_failure_jump:
4382 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4384 /* If the next operation is not a jump backwards in the
4389 /* Go through the on_failure_jumps of the alternatives,
4390 seeing if any of the alternatives cannot match nothing.
4391 The last alternative starts with only a jump,
4392 whereas the rest start with on_failure_jump and end
4393 with a jump, e.g., here is the pattern for `a|b|c':
4395 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4396 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4399 So, we have to first go through the first (n-1)
4400 alternatives and then deal with the last one separately. */
4403 /* Deal with the first (n-1) alternatives, which start
4404 with an on_failure_jump (see above) that jumps to right
4405 past a jump_past_alt. */
4407 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4409 /* `mcnt' holds how many bytes long the alternative
4410 is, including the ending `jump_past_alt' and
4413 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4417 /* Move to right after this alternative, including the
4421 /* Break if it's the beginning of an n-th alternative
4422 that doesn't begin with an on_failure_jump. */
4423 if ((re_opcode_t) *p1 != on_failure_jump)
4426 /* Still have to check that it's not an n-th
4427 alternative that starts with an on_failure_jump. */
4429 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4430 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4432 /* Get to the beginning of the n-th alternative. */
4438 /* Deal with the last alternative: go back and get number
4439 of the `jump_past_alt' just before it. `mcnt' contains
4440 the length of the alternative. */
4441 EXTRACT_NUMBER (mcnt, p1 - 2);
4443 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4446 p1 += mcnt; /* Get past the n-th alternative. */
4452 assert (p1[1] == **p);
4458 if (!common_op_match_null_string_p (&p1, end, reg_info))
4461 } /* while p1 < end */
4464 } /* group_match_null_string_p */
4467 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4468 It expects P to be the first byte of a single alternative and END one
4469 byte past the last. The alternative can contain groups. */
4472 alt_match_null_string_p (p, end, reg_info)
4473 unsigned char *p, *end;
4474 register_info_type *reg_info;
4477 unsigned char *p1 = p;
4481 /* Skip over opcodes that can match nothing, and break when we get
4482 to one that can't. */
4484 switch ((re_opcode_t) *p1)
4487 case on_failure_jump:
4489 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4494 if (!common_op_match_null_string_p (&p1, end, reg_info))
4497 } /* while p1 < end */
4500 } /* alt_match_null_string_p */
4503 /* Deals with the ops common to group_match_null_string_p and
4504 alt_match_null_string_p.
4506 Sets P to one after the op and its arguments, if any. */
4509 common_op_match_null_string_p (p, end, reg_info)
4510 unsigned char **p, *end;
4511 register_info_type *reg_info;
4516 unsigned char *p1 = *p;
4518 switch ((re_opcode_t) *p1++)
4538 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
4539 ret = group_match_null_string_p (&p1, end, reg_info);
4541 /* Have to set this here in case we're checking a group which
4542 contains a group and a back reference to it. */
4544 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
4545 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
4551 /* If this is an optimized succeed_n for zero times, make the jump. */
4553 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4561 /* Get to the number of times to succeed. */
4563 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4568 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4576 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
4584 /* All other opcodes mean we cannot match the empty string. */
4590 } /* common_op_match_null_string_p */
4593 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
4594 bytes; nonzero otherwise. */
4597 bcmp_translate (s1, s2, len, translate)
4598 unsigned char *s1, *s2;
4602 register unsigned char *p1 = s1, *p2 = s2;
4605 if (translate[*p1++] != translate[*p2++]) return 1;
4611 /* Entry points for GNU code. */
4613 /* re_compile_pattern is the GNU regular expression compiler: it
4614 compiles PATTERN (of length SIZE) and puts the result in BUFP.
4615 Returns 0 if the pattern was valid, otherwise an error string.
4617 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
4618 are set in BUFP on entry.
4620 We call regex_compile to do the actual compilation. */
4623 re_compile_pattern (pattern, length, bufp)
4624 const char *pattern;
4626 struct re_pattern_buffer *bufp;
4630 /* GNU code is written to assume at least RE_NREGS registers will be set
4631 (and at least one extra will be -1). */
4632 bufp->regs_allocated = REGS_UNALLOCATED;
4634 /* And GNU code determines whether or not to get register information
4635 by passing null for the REGS argument to re_match, etc., not by
4639 /* Match anchors at newline. */
4640 bufp->newline_anchor = 1;
4642 ret = regex_compile (pattern, length, re_syntax_options, bufp);
4644 return re_error_msg[(int) ret];
4647 /* Entry points compatible with 4.2 BSD regex library. We don't define
4648 them if this is an Emacs or POSIX compilation. */
4650 #if !defined (emacs) && !defined (_POSIX_SOURCE)
4652 /* BSD has one and only one pattern buffer. */
4653 static struct re_pattern_buffer re_comp_buf;
4663 if (!re_comp_buf.buffer)
4664 return "No previous regular expression";
4668 if (!re_comp_buf.buffer)
4670 re_comp_buf.buffer = (unsigned char *) malloc (200);
4671 if (re_comp_buf.buffer == NULL)
4672 return "Memory exhausted";
4673 re_comp_buf.allocated = 200;
4675 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
4676 if (re_comp_buf.fastmap == NULL)
4677 return "Memory exhausted";
4680 /* Since `re_exec' always passes NULL for the `regs' argument, we
4681 don't need to initialize the pattern buffer fields which affect it. */
4683 /* Match anchors at newlines. */
4684 re_comp_buf.newline_anchor = 1;
4686 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
4688 /* Yes, we're discarding `const' here. */
4689 return (char *) re_error_msg[(int) ret];
4697 const int len = strlen (s);
4699 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
4701 #endif /* not emacs and not _POSIX_SOURCE */
4703 /* POSIX.2 functions. Don't define these for Emacs. */
4707 /* regcomp takes a regular expression as a string and compiles it.
4709 PREG is a regex_t *. We do not expect any fields to be initialized,
4710 since POSIX says we shouldn't. Thus, we set
4712 `buffer' to the compiled pattern;
4713 `used' to the length of the compiled pattern;
4714 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
4715 REG_EXTENDED bit in CFLAGS is set; otherwise, to
4716 RE_SYNTAX_POSIX_BASIC;
4717 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
4718 `fastmap' and `fastmap_accurate' to zero;
4719 `re_nsub' to the number of subexpressions in PATTERN.
4721 PATTERN is the address of the pattern string.
4723 CFLAGS is a series of bits which affect compilation.
4725 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
4726 use POSIX basic syntax.
4728 If REG_NEWLINE is set, then . and [^...] don't match newline.
4729 Also, regexec will try a match beginning after every newline.
4731 If REG_ICASE is set, then we considers upper- and lowercase
4732 versions of letters to be equivalent when matching.
4734 If REG_NOSUB is set, then when PREG is passed to regexec, that
4735 routine will report only success or failure, and nothing about the
4738 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
4739 the return codes and their meanings.) */
4742 regcomp (preg, pattern, cflags)
4744 const char *pattern;
4749 = (cflags & REG_EXTENDED) ?
4750 RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
4752 /* regex_compile will allocate the space for the compiled pattern. */
4754 preg->allocated = 0;
4756 /* Don't bother to use a fastmap when searching. This simplifies the
4757 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
4758 characters after newlines into the fastmap. This way, we just try
4762 if (cflags & REG_ICASE)
4766 preg->translate = (char *) malloc (CHAR_SET_SIZE);
4767 if (preg->translate == NULL)
4768 return (int) REG_ESPACE;
4770 /* Map uppercase characters to corresponding lowercase ones. */
4771 for (i = 0; i < CHAR_SET_SIZE; i++)
4772 preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
4775 preg->translate = NULL;
4777 /* If REG_NEWLINE is set, newlines are treated differently. */
4778 if (cflags & REG_NEWLINE)
4779 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
4780 syntax &= ~RE_DOT_NEWLINE;
4781 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
4782 /* It also changes the matching behavior. */
4783 preg->newline_anchor = 1;
4786 preg->newline_anchor = 0;
4788 preg->no_sub = !!(cflags & REG_NOSUB);
4790 /* POSIX says a null character in the pattern terminates it, so we
4791 can use strlen here in compiling the pattern. */
4792 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
4794 /* POSIX doesn't distinguish between an unmatched open-group and an
4795 unmatched close-group: both are REG_EPAREN. */
4796 if (ret == REG_ERPAREN) ret = REG_EPAREN;
4802 /* regexec searches for a given pattern, specified by PREG, in the
4805 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
4806 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
4807 least NMATCH elements, and we set them to the offsets of the
4808 corresponding matched substrings.
4810 EFLAGS specifies `execution flags' which affect matching: if
4811 REG_NOTBOL is set, then ^ does not match at the beginning of the
4812 string; if REG_NOTEOL is set, then $ does not match at the end.
4814 We return 0 if we find a match and REG_NOMATCH if not. */
4817 regexec (preg, string, nmatch, pmatch, eflags)
4818 const regex_t *preg;
4821 regmatch_t pmatch[];
4825 struct re_registers regs;
4826 regex_t private_preg;
4827 int len = strlen (string);
4828 boolean want_reg_info = !preg->no_sub && nmatch > 0;
4830 private_preg = *preg;
4832 private_preg.not_bol = !!(eflags & REG_NOTBOL);
4833 private_preg.not_eol = !!(eflags & REG_NOTEOL);
4835 /* The user has told us exactly how many registers to return
4836 information about, via `nmatch'. We have to pass that on to the
4837 matching routines. */
4838 private_preg.regs_allocated = REGS_FIXED;
4842 regs.num_regs = nmatch;
4843 regs.start = TALLOC (nmatch, regoff_t);
4844 regs.end = TALLOC (nmatch, regoff_t);
4845 if (regs.start == NULL || regs.end == NULL)
4846 return (int) REG_NOMATCH;
4849 /* Perform the searching operation. */
4850 ret = re_search (&private_preg, string, len,
4851 /* start: */ 0, /* range: */ len,
4852 want_reg_info ? ®s : (struct re_registers *) 0);
4854 /* Copy the register information to the POSIX structure. */
4861 for (r = 0; r < nmatch; r++)
4863 pmatch[r].rm_so = regs.start[r];
4864 pmatch[r].rm_eo = regs.end[r];
4868 /* If we needed the temporary register info, free the space now. */
4873 /* We want zero return to mean success, unlike `re_search'. */
4874 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
4878 /* Returns a message corresponding to an error code, ERRCODE, returned
4879 from either regcomp or regexec. We don't use PREG here. */
4882 regerror (errcode, preg, errbuf, errbuf_size)
4884 const regex_t *preg;
4892 || errcode >= (sizeof (re_error_msg) / sizeof (re_error_msg[0])))
4893 /* Only error codes returned by the rest of the code should be passed
4894 to this routine. If we are given anything else, or if other regex
4895 code generates an invalid error code, then the program has a bug.
4896 Dump core so we can fix it. */
4899 msg = re_error_msg[errcode];
4901 /* POSIX doesn't require that we do anything in this case, but why
4906 msg_size = strlen (msg) + 1; /* Includes the null. */
4908 if (errbuf_size != 0)
4910 if (msg_size > errbuf_size)
4912 strncpy (errbuf, msg, errbuf_size - 1);
4913 errbuf[errbuf_size - 1] = 0;
4916 strcpy (errbuf, msg);
4923 /* Free dynamically allocated space used by PREG. */
4929 if (preg->buffer != NULL)
4930 free (preg->buffer);
4931 preg->buffer = NULL;
4933 preg->allocated = 0;
4936 if (preg->fastmap != NULL)
4937 free (preg->fastmap);
4938 preg->fastmap = NULL;
4939 preg->fastmap_accurate = 0;
4941 if (preg->translate != NULL)
4942 free (preg->translate);
4943 preg->translate = NULL;
4946 #endif /* not emacs */
4950 make-backup-files: t
4952 trim-versions-without-asking: nil