1 /* Extended regular expression matching and search library,
3 (Implements POSIX draft P10003.2/D11.2, except for
4 internationalization features.)
6 Copyright (C) 1985, 89, 90, 91, 92 Free Software Foundation, Inc.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
22 /* AIX requires this to be the first thing in the file. */
23 #if defined (_AIX) && !defined (REGEX_MALLOC)
29 /* We need this for `regex.h', and perhaps for the Emacs include files. */
30 #include <sys/types.h>
32 /* The `emacs' switch turns on certain matching commands
33 that make sense only in Emacs. */
41 /* Emacs uses `NULL' as a predicate. */
46 /* We used to test for `BSTRING' here, but only GCC and Emacs define
47 `BSTRING', as far as I know, and neither of them use this code. */
48 #if HAVE_STRING_H || STDC_HEADERS
51 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
54 #define bcopy(s, d, n) memcpy ((d), (s), (n))
57 #define bzero(s, n) memset ((s), 0, (n))
71 /* Define the syntax stuff for \<, \>, etc. */
73 /* This must be nonzero for the wordchar and notwordchar pattern
74 commands in re_match_2. */
81 extern char *re_syntax_table;
83 #else /* not SYNTAX_TABLE */
85 /* How many characters in the character set. */
86 #define CHAR_SET_SIZE 256
88 static char re_syntax_table[CHAR_SET_SIZE];
99 bzero (re_syntax_table, sizeof re_syntax_table);
101 for (c = 'a'; c <= 'z'; c++)
102 re_syntax_table[c] = Sword;
104 for (c = 'A'; c <= 'Z'; c++)
105 re_syntax_table[c] = Sword;
107 for (c = '0'; c <= '9'; c++)
108 re_syntax_table[c] = Sword;
110 re_syntax_table['_'] = Sword;
115 #endif /* not SYNTAX_TABLE */
117 #define SYNTAX(c) re_syntax_table[c]
119 #endif /* not emacs */
121 /* Get the interface, including the syntax bits. */
125 /* isalpha etc. are used for the character classes. */
128 #define isgraph(c) (isprint (c) && !isspace (c))
131 #define isblank(c) ((c) == ' ' || (c) == '\t')
138 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
139 since ours (we hope) works properly with all combinations of
140 machines, compilers, `char' and `unsigned char' argument types.
141 (Per Bothner suggested the basic approach.) */
142 #undef SIGN_EXTEND_CHAR
144 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
145 #else /* not __STDC__ */
146 /* As in Harbison and Steele. */
147 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
150 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
151 use `alloca' instead of `malloc'. This is because using malloc in
152 re_search* or re_match* could cause memory leaks when C-g is used in
153 Emacs; also, malloc is slower and causes storage fragmentation. On
154 the other hand, malloc is more portable, and easier to debug.
156 Because we sometimes use alloca, some routines have to be macros,
157 not functions -- `alloca'-allocated space disappears at the end of the
158 function it is called in. */
162 #define REGEX_ALLOCATE malloc
163 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
165 #else /* not REGEX_MALLOC */
167 /* Emacs already defines alloca, sometimes. */
170 /* Make alloca work the best possible way. */
172 #define alloca __builtin_alloca
173 #else /* not __GNUC__ */
176 #else /* not __GNUC__ or HAVE_ALLOCA_H */
177 #ifndef _AIX /* Already did AIX, up at the top. */
179 #endif /* not _AIX */
180 #endif /* not HAVE_ALLOCA_H */
181 #endif /* not __GNUC__ */
183 #endif /* not alloca */
185 #define REGEX_ALLOCATE alloca
187 /* Assumes a `char *destination' variable. */
188 #define REGEX_REALLOCATE(source, osize, nsize) \
189 (destination = (char *) alloca (nsize), \
190 bcopy (source, destination, osize), \
193 #endif /* not REGEX_MALLOC */
196 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
197 `string1' or just past its end. This works if PTR is NULL, which is
199 #define FIRST_STRING_P(ptr) \
200 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
202 /* (Re)Allocate N items of type T using malloc, or fail. */
203 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
204 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
205 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
207 #define BYTEWIDTH 8 /* In bits. */
209 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
211 #define MAX(a, b) ((a) > (b) ? (a) : (b))
212 #define MIN(a, b) ((a) < (b) ? (a) : (b))
214 typedef char boolean;
218 /* These are the command codes that appear in compiled regular
219 expressions. Some opcodes are followed by argument bytes. A
220 command code can specify any interpretation whatsoever for its
221 arguments. Zero bytes may appear in the compiled regular expression.
223 The value of `exactn' is needed in search.c (search_buffer) in Emacs.
224 So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of
225 `exactn' we use here must also be 1. */
231 /* Followed by one byte giving n, then by n literal bytes. */
234 /* Matches any (more or less) character. */
237 /* Matches any one char belonging to specified set. First
238 following byte is number of bitmap bytes. Then come bytes
239 for a bitmap saying which chars are in. Bits in each byte
240 are ordered low-bit-first. A character is in the set if its
241 bit is 1. A character too large to have a bit in the map is
242 automatically not in the set. */
245 /* Same parameters as charset, but match any character that is
246 not one of those specified. */
249 /* Start remembering the text that is matched, for storing in a
250 register. Followed by one byte with the register number, in
251 the range 0 to one less than the pattern buffer's re_nsub
252 field. Then followed by one byte with the number of groups
253 inner to this one. (This last has to be part of the
254 start_memory only because we need it in the on_failure_jump
258 /* Stop remembering the text that is matched and store it in a
259 memory register. Followed by one byte with the register
260 number, in the range 0 to one less than `re_nsub' in the
261 pattern buffer, and one byte with the number of inner groups,
262 just like `start_memory'. (We need the number of inner
263 groups here because we don't have any easy way of finding the
264 corresponding start_memory when we're at a stop_memory.) */
267 /* Match a duplicate of something remembered. Followed by one
268 byte containing the register number. */
271 /* Fail unless at beginning of line. */
274 /* Fail unless at end of line. */
277 /* Succeeds if at beginning of buffer (if emacs) or at beginning
278 of string to be matched (if not). */
281 /* Analogously, for end of buffer/string. */
284 /* Followed by two byte relative address to which to jump. */
287 /* Same as jump, but marks the end of an alternative. */
290 /* Followed by two-byte relative address of place to resume at
291 in case of failure. */
294 /* Like on_failure_jump, but pushes a placeholder instead of the
295 current string position when executed. */
296 on_failure_keep_string_jump,
298 /* Throw away latest failure point and then jump to following
299 two-byte relative address. */
302 /* Change to pop_failure_jump if know won't have to backtrack to
303 match; otherwise change to jump. This is used to jump
304 back to the beginning of a repeat. If what follows this jump
305 clearly won't match what the repeat does, such that we can be
306 sure that there is no use backtracking out of repetitions
307 already matched, then we change it to a pop_failure_jump.
308 Followed by two-byte address. */
311 /* Jump to following two-byte address, and push a dummy failure
312 point. This failure point will be thrown away if an attempt
313 is made to use it for a failure. A `+' construct makes this
314 before the first repeat. Also used as an intermediary kind
315 of jump when compiling an alternative. */
318 /* Push a dummy failure point and continue. Used at the end of
322 /* Followed by two-byte relative address and two-byte number n.
323 After matching N times, jump to the address upon failure. */
326 /* Followed by two-byte relative address, and two-byte number n.
327 Jump to the address N times, then fail. */
330 /* Set the following two-byte relative address to the
331 subsequent two-byte number. The address *includes* the two
335 wordchar, /* Matches any word-constituent character. */
336 notwordchar, /* Matches any char that is not a word-constituent. */
338 wordbeg, /* Succeeds if at word beginning. */
339 wordend, /* Succeeds if at word end. */
341 wordbound, /* Succeeds if at a word boundary. */
342 notwordbound /* Succeeds if not at a word boundary. */
345 ,before_dot, /* Succeeds if before point. */
346 at_dot, /* Succeeds if at point. */
347 after_dot, /* Succeeds if after point. */
349 /* Matches any character whose syntax is specified. Followed by
350 a byte which contains a syntax code, e.g., Sword. */
353 /* Matches any character whose syntax is not that specified. */
358 /* Common operations on the compiled pattern. */
360 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
362 #define STORE_NUMBER(destination, number) \
364 (destination)[0] = (number) & 0377; \
365 (destination)[1] = (number) >> 8; \
368 /* Same as STORE_NUMBER, except increment DESTINATION to
369 the byte after where the number is stored. Therefore, DESTINATION
370 must be an lvalue. */
372 #define STORE_NUMBER_AND_INCR(destination, number) \
374 STORE_NUMBER (destination, number); \
375 (destination) += 2; \
378 /* Put into DESTINATION a number stored in two contiguous bytes starting
381 #define EXTRACT_NUMBER(destination, source) \
383 (destination) = *(source) & 0377; \
384 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
389 extract_number (dest, source)
391 unsigned char *source;
393 int temp = SIGN_EXTEND_CHAR (*(source + 1));
394 *dest = *source & 0377;
398 #ifndef EXTRACT_MACROS /* To debug the macros. */
399 #undef EXTRACT_NUMBER
400 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
401 #endif /* not EXTRACT_MACROS */
405 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
406 SOURCE must be an lvalue. */
408 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
410 EXTRACT_NUMBER (destination, source); \
416 extract_number_and_incr (destination, source)
418 unsigned char **source;
420 extract_number (destination, *source);
424 #ifndef EXTRACT_MACROS
425 #undef EXTRACT_NUMBER_AND_INCR
426 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
427 extract_number_and_incr (&dest, &src)
428 #endif /* not EXTRACT_MACROS */
432 /* If DEBUG is defined, Regex prints many voluminous messages about what
433 it is doing (if the variable `debug' is nonzero). If linked with the
434 main program in `iregex.c', you can enter patterns and strings
435 interactively. And if linked with the main program in `main.c' and
436 the other test files, you can run the already-written tests. */
440 /* We use standard I/O for debugging. */
443 /* It is useful to test things that ``must'' be true when debugging. */
446 static int debug = 0;
448 #define DEBUG_STATEMENT(e) e
449 #define DEBUG_PRINT1(x) if (debug) printf (x)
450 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
451 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
452 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
453 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
454 if (debug) print_partial_compiled_pattern (s, e)
455 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
456 if (debug) print_double_string (w, s1, sz1, s2, sz2)
459 extern void printchar ();
461 /* Print the fastmap in human-readable form. */
464 print_fastmap (fastmap)
467 unsigned was_a_range = 0;
470 while (i < (1 << BYTEWIDTH))
476 while (i < (1 << BYTEWIDTH) && fastmap[i])
492 /* Print a compiled pattern string in human-readable form, starting at
493 the START pointer into it and ending just before the pointer END. */
496 print_partial_compiled_pattern (start, end)
497 unsigned char *start;
501 unsigned char *p = start;
502 unsigned char *pend = end;
510 /* Loop over pattern commands. */
513 switch ((re_opcode_t) *p++)
521 printf ("/exactn/%d", mcnt);
532 printf ("/start_memory/%d/%d", mcnt, *p++);
537 printf ("/stop_memory/%d/%d", mcnt, *p++);
541 printf ("/duplicate/%d", *p++);
553 printf ("/charset%s",
554 (re_opcode_t) *(p - 1) == charset_not ? "_not" : "");
556 assert (p + *p < pend);
558 for (c = 0; c < *p; c++)
561 unsigned char map_byte = p[1 + c];
565 for (bit = 0; bit < BYTEWIDTH; bit++)
566 if (map_byte & (1 << bit))
567 printchar (c * BYTEWIDTH + bit);
581 case on_failure_jump:
582 extract_number_and_incr (&mcnt, &p);
583 printf ("/on_failure_jump/0/%d", mcnt);
586 case on_failure_keep_string_jump:
587 extract_number_and_incr (&mcnt, &p);
588 printf ("/on_failure_keep_string_jump/0/%d", mcnt);
591 case dummy_failure_jump:
592 extract_number_and_incr (&mcnt, &p);
593 printf ("/dummy_failure_jump/0/%d", mcnt);
596 case push_dummy_failure:
597 printf ("/push_dummy_failure");
601 extract_number_and_incr (&mcnt, &p);
602 printf ("/maybe_pop_jump/0/%d", mcnt);
605 case pop_failure_jump:
606 extract_number_and_incr (&mcnt, &p);
607 printf ("/pop_failure_jump/0/%d", mcnt);
611 extract_number_and_incr (&mcnt, &p);
612 printf ("/jump_past_alt/0/%d", mcnt);
616 extract_number_and_incr (&mcnt, &p);
617 printf ("/jump/0/%d", mcnt);
621 extract_number_and_incr (&mcnt, &p);
622 extract_number_and_incr (&mcnt2, &p);
623 printf ("/succeed_n/0/%d/0/%d", mcnt, mcnt2);
627 extract_number_and_incr (&mcnt, &p);
628 extract_number_and_incr (&mcnt2, &p);
629 printf ("/jump_n/0/%d/0/%d", mcnt, mcnt2);
633 extract_number_and_incr (&mcnt, &p);
634 extract_number_and_incr (&mcnt2, &p);
635 printf ("/set_number_at/0/%d/0/%d", mcnt, mcnt2);
639 printf ("/wordbound");
643 printf ("/notwordbound");
655 printf ("/before_dot");
663 printf ("/after_dot");
667 printf ("/syntaxspec");
669 printf ("/%d", mcnt);
673 printf ("/notsyntaxspec");
675 printf ("/%d", mcnt);
680 printf ("/wordchar");
684 printf ("/notwordchar");
696 printf ("?%d", *(p-1));
704 print_compiled_pattern (bufp)
705 struct re_pattern_buffer *bufp;
707 unsigned char *buffer = bufp->buffer;
709 print_partial_compiled_pattern (buffer, buffer + bufp->used);
710 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
712 if (bufp->fastmap_accurate && bufp->fastmap)
714 printf ("fastmap: ");
715 print_fastmap (bufp->fastmap);
718 printf ("re_nsub: %d\t", bufp->re_nsub);
719 printf ("regs_alloc: %d\t", bufp->regs_allocated);
720 printf ("can_be_null: %d\t", bufp->can_be_null);
721 printf ("newline_anchor: %d\n", bufp->newline_anchor);
722 printf ("no_sub: %d\t", bufp->no_sub);
723 printf ("not_bol: %d\t", bufp->not_bol);
724 printf ("not_eol: %d\t", bufp->not_eol);
725 printf ("syntax: %d\n", bufp->syntax);
726 /* Perhaps we should print the translate table? */
731 print_double_string (where, string1, size1, string2, size2)
744 if (FIRST_STRING_P (where))
746 for (this_char = where - string1; this_char < size1; this_char++)
747 printchar (string1[this_char]);
752 for (this_char = where - string2; this_char < size2; this_char++)
753 printchar (string2[this_char]);
757 #else /* not DEBUG */
762 #define DEBUG_STATEMENT(e)
763 #define DEBUG_PRINT1(x)
764 #define DEBUG_PRINT2(x1, x2)
765 #define DEBUG_PRINT3(x1, x2, x3)
766 #define DEBUG_PRINT4(x1, x2, x3, x4)
767 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
768 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
770 #endif /* not DEBUG */
772 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
773 also be assigned to arbitrarily: each pattern buffer stores its own
774 syntax, so it can be changed between regex compilations. */
775 reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS;
778 /* Specify the precise syntax of regexps for compilation. This provides
779 for compatibility for various utilities which historically have
780 different, incompatible syntaxes.
782 The argument SYNTAX is a bit mask comprised of the various bits
783 defined in regex.h. We return the old syntax. */
786 re_set_syntax (syntax)
789 reg_syntax_t ret = re_syntax_options;
791 re_syntax_options = syntax;
795 /* This table gives an error message for each of the error codes listed
796 in regex.h. Obviously the order here has to be same as there. */
798 static const char *re_error_msg[] =
799 { NULL, /* REG_NOERROR */
800 "No match", /* REG_NOMATCH */
801 "Invalid regular expression", /* REG_BADPAT */
802 "Invalid collation character", /* REG_ECOLLATE */
803 "Invalid character class name", /* REG_ECTYPE */
804 "Trailing backslash", /* REG_EESCAPE */
805 "Invalid back reference", /* REG_ESUBREG */
806 "Unmatched [ or [^", /* REG_EBRACK */
807 "Unmatched ( or \\(", /* REG_EPAREN */
808 "Unmatched \\{", /* REG_EBRACE */
809 "Invalid content of \\{\\}", /* REG_BADBR */
810 "Invalid range end", /* REG_ERANGE */
811 "Memory exhausted", /* REG_ESPACE */
812 "Invalid preceding regular expression", /* REG_BADRPT */
813 "Premature end of regular expression", /* REG_EEND */
814 "Regular expression too big", /* REG_ESIZE */
815 "Unmatched ) or \\)", /* REG_ERPAREN */
818 /* Subroutine declarations and macros for regex_compile. */
820 static void store_op1 (), store_op2 ();
821 static void insert_op1 (), insert_op2 ();
822 static boolean at_begline_loc_p (), at_endline_loc_p ();
823 static boolean group_in_compile_stack ();
824 static reg_errcode_t compile_range ();
826 /* Fetch the next character in the uncompiled pattern---translating it
827 if necessary. Also cast from a signed character in the constant
828 string passed to us by the user to an unsigned char that we can use
829 as an array index (in, e.g., `translate'). */
830 #define PATFETCH(c) \
831 do {if (p == pend) return REG_EEND; \
832 c = (unsigned char) *p++; \
833 if (translate) c = translate[c]; \
836 /* Fetch the next character in the uncompiled pattern, with no
838 #define PATFETCH_RAW(c) \
839 do {if (p == pend) return REG_EEND; \
840 c = (unsigned char) *p++; \
843 /* Go backwards one character in the pattern. */
844 #define PATUNFETCH p--
847 /* If `translate' is non-null, return translate[D], else just D. We
848 cast the subscript to translate because some data is declared as
849 `char *', to avoid warnings when a string constant is passed. But
850 when we use a character as a subscript we must make it unsigned. */
851 #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
854 /* Macros for outputting the compiled pattern into `buffer'. */
856 /* If the buffer isn't allocated when it comes in, use this. */
857 #define INIT_BUF_SIZE 32
859 /* Make sure we have at least N more bytes of space in buffer. */
860 #define GET_BUFFER_SPACE(n) \
861 while (b - bufp->buffer + (n) > bufp->allocated) \
864 /* Make sure we have one more byte of buffer space and then add C to it. */
865 #define BUF_PUSH(c) \
867 GET_BUFFER_SPACE (1); \
868 *b++ = (unsigned char) (c); \
872 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
873 #define BUF_PUSH_2(c1, c2) \
875 GET_BUFFER_SPACE (2); \
876 *b++ = (unsigned char) (c1); \
877 *b++ = (unsigned char) (c2); \
881 /* As with BUF_PUSH_2, except for three bytes. */
882 #define BUF_PUSH_3(c1, c2, c3) \
884 GET_BUFFER_SPACE (3); \
885 *b++ = (unsigned char) (c1); \
886 *b++ = (unsigned char) (c2); \
887 *b++ = (unsigned char) (c3); \
891 /* Store a jump with opcode OP at LOC to location TO. We store a
892 relative address offset by the three bytes the jump itself occupies. */
893 #define STORE_JUMP(op, loc, to) \
894 store_op1 (op, loc, (to) - (loc) - 3)
896 /* Likewise, for a two-argument jump. */
897 #define STORE_JUMP2(op, loc, to, arg) \
898 store_op2 (op, loc, (to) - (loc) - 3, arg)
900 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
901 #define INSERT_JUMP(op, loc, to) \
902 insert_op1 (op, loc, (to) - (loc) - 3, b)
904 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
905 #define INSERT_JUMP2(op, loc, to, arg) \
906 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
909 /* This is not an arbitrary limit: the arguments which represent offsets
910 into the pattern are two bytes long. So if 2^16 bytes turns out to
911 be too small, many things would have to change. */
912 #define MAX_BUF_SIZE (1L << 16)
915 /* Extend the buffer by twice its current size via realloc and
916 reset the pointers that pointed into the old block to point to the
917 correct places in the new one. If extending the buffer results in it
918 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
919 #define EXTEND_BUFFER() \
921 unsigned char *old_buffer = bufp->buffer; \
922 if (bufp->allocated == MAX_BUF_SIZE) \
924 bufp->allocated <<= 1; \
925 if (bufp->allocated > MAX_BUF_SIZE) \
926 bufp->allocated = MAX_BUF_SIZE; \
927 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
928 if (bufp->buffer == NULL) \
930 /* If the buffer moved, move all the pointers into it. */ \
931 if (old_buffer != bufp->buffer) \
933 b = (b - old_buffer) + bufp->buffer; \
934 begalt = (begalt - old_buffer) + bufp->buffer; \
935 if (fixup_alt_jump) \
936 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
938 laststart = (laststart - old_buffer) + bufp->buffer; \
940 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
945 /* Since we have one byte reserved for the register number argument to
946 {start,stop}_memory, the maximum number of groups we can report
947 things about is what fits in that byte. */
948 #define MAX_REGNUM 255
950 /* But patterns can have more than `MAX_REGNUM' registers. We just
951 ignore the excess. */
952 typedef unsigned regnum_t;
955 /* Macros for the compile stack. */
957 /* Since offsets can go either forwards or backwards, this type needs to
958 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
959 typedef int pattern_offset_t;
963 pattern_offset_t begalt_offset;
964 pattern_offset_t fixup_alt_jump;
965 pattern_offset_t inner_group_offset;
966 pattern_offset_t laststart_offset;
968 } compile_stack_elt_t;
973 compile_stack_elt_t *stack;
975 unsigned avail; /* Offset of next open position. */
976 } compile_stack_type;
979 #define INIT_COMPILE_STACK_SIZE 32
981 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
982 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
984 /* The next available element. */
985 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
988 /* Set the bit for character C in a list. */
989 #define SET_LIST_BIT(c) \
990 (b[((unsigned char) (c)) / BYTEWIDTH] \
991 |= 1 << (((unsigned char) c) % BYTEWIDTH))
994 /* Get the next unsigned number in the uncompiled pattern. */
995 #define GET_UNSIGNED_NUMBER(num) \
999 while (isdigit (c)) \
1003 num = num * 10 + c - '0'; \
1011 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1013 #define IS_CHAR_CLASS(string) \
1014 (STREQ (string, "alpha") || STREQ (string, "upper") \
1015 || STREQ (string, "lower") || STREQ (string, "digit") \
1016 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1017 || STREQ (string, "space") || STREQ (string, "print") \
1018 || STREQ (string, "punct") || STREQ (string, "graph") \
1019 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1021 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1022 Returns one of error codes defined in `regex.h', or zero for success.
1024 Assumes the `allocated' (and perhaps `buffer') and `translate'
1025 fields are set in BUFP on entry.
1027 If it succeeds, results are put in BUFP (if it returns an error, the
1028 contents of BUFP are undefined):
1029 `buffer' is the compiled pattern;
1030 `syntax' is set to SYNTAX;
1031 `used' is set to the length of the compiled pattern;
1032 `fastmap_accurate' is zero;
1033 `re_nsub' is the number of subexpressions in PATTERN;
1034 `not_bol' and `not_eol' are zero;
1036 The `fastmap' and `newline_anchor' fields are neither
1037 examined nor set. */
1039 static reg_errcode_t
1040 regex_compile (pattern, size, syntax, bufp)
1041 const char *pattern;
1043 reg_syntax_t syntax;
1044 struct re_pattern_buffer *bufp;
1046 /* We fetch characters from PATTERN here. Even though PATTERN is
1047 `char *' (i.e., signed), we declare these variables as unsigned, so
1048 they can be reliably used as array indices. */
1049 register unsigned char c, c1;
1051 /* A random tempory spot in PATTERN. */
1054 /* Points to the end of the buffer, where we should append. */
1055 register unsigned char *b;
1057 /* Keeps track of unclosed groups. */
1058 compile_stack_type compile_stack;
1060 /* Points to the current (ending) position in the pattern. */
1061 const char *p = pattern;
1062 const char *pend = pattern + size;
1064 /* How to translate the characters in the pattern. */
1065 char *translate = bufp->translate;
1067 /* Address of the count-byte of the most recently inserted `exactn'
1068 command. This makes it possible to tell if a new exact-match
1069 character can be added to that command or if the character requires
1070 a new `exactn' command. */
1071 unsigned char *pending_exact = 0;
1073 /* Address of start of the most recently finished expression.
1074 This tells, e.g., postfix * where to find the start of its
1075 operand. Reset at the beginning of groups and alternatives. */
1076 unsigned char *laststart = 0;
1078 /* Address of beginning of regexp, or inside of last group. */
1079 unsigned char *begalt;
1081 /* Place in the uncompiled pattern (i.e., the {) to
1082 which to go back if the interval is invalid. */
1083 const char *beg_interval;
1085 /* Address of the place where a forward jump should go to the end of
1086 the containing expression. Each alternative of an `or' -- except the
1087 last -- ends with a forward jump of this sort. */
1088 unsigned char *fixup_alt_jump = 0;
1090 /* Counts open-groups as they are encountered. Remembered for the
1091 matching close-group on the compile stack, so the same register
1092 number is put in the stop_memory as the start_memory. */
1093 regnum_t regnum = 0;
1096 DEBUG_PRINT1 ("\nCompiling pattern: ");
1099 unsigned debug_count;
1101 for (debug_count = 0; debug_count < size; debug_count++)
1102 printchar (pattern[debug_count]);
1107 /* Initialize the compile stack. */
1108 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1109 if (compile_stack.stack == NULL)
1112 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1113 compile_stack.avail = 0;
1115 /* Initialize the pattern buffer. */
1116 bufp->syntax = syntax;
1117 bufp->fastmap_accurate = 0;
1118 bufp->not_bol = bufp->not_eol = 0;
1120 /* Set `used' to zero, so that if we return an error, the pattern
1121 printer (for debugging) will think there's no pattern. We reset it
1125 /* Always count groups, whether or not bufp->no_sub is set. */
1128 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1129 /* Initialize the syntax table. */
1130 init_syntax_once ();
1133 if (bufp->allocated == 0)
1136 { /* If zero allocated, but buffer is non-null, try to realloc
1137 enough space. This loses if buffer's address is bogus, but
1138 that is the user's responsibility. */
1139 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1142 { /* Caller did not allocate a buffer. Do it for them. */
1143 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1145 if (!bufp->buffer) return REG_ESPACE;
1147 bufp->allocated = INIT_BUF_SIZE;
1150 begalt = b = bufp->buffer;
1152 /* Loop through the uncompiled pattern until we're at the end. */
1161 if ( /* If at start of pattern, it's an operator. */
1163 /* If context independent, it's an operator. */
1164 || syntax & RE_CONTEXT_INDEP_ANCHORS
1165 /* Otherwise, depends on what's come before. */
1166 || at_begline_loc_p (pattern, p, syntax))
1176 if ( /* If at end of pattern, it's an operator. */
1178 /* If context independent, it's an operator. */
1179 || syntax & RE_CONTEXT_INDEP_ANCHORS
1180 /* Otherwise, depends on what's next. */
1181 || at_endline_loc_p (p, pend, syntax))
1191 if ((syntax & RE_BK_PLUS_QM)
1192 || (syntax & RE_LIMITED_OPS))
1196 /* If there is no previous pattern... */
1199 if (syntax & RE_CONTEXT_INVALID_OPS)
1201 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1206 /* Are we optimizing this jump? */
1207 boolean keep_string_p = false;
1209 /* 1 means zero (many) matches is allowed. */
1210 char zero_times_ok = 0, many_times_ok = 0;
1212 /* If there is a sequence of repetition chars, collapse it
1213 down to just one (the right one). We can't combine
1214 interval operators with these because of, e.g., `a{2}*',
1215 which should only match an even number of `a's. */
1219 zero_times_ok |= c != '+';
1220 many_times_ok |= c != '?';
1228 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1231 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1233 if (p == pend) return REG_EESCAPE;
1236 if (!(c1 == '+' || c1 == '?'))
1251 /* If we get here, we found another repeat character. */
1254 /* Star, etc. applied to an empty pattern is equivalent
1255 to an empty pattern. */
1259 /* Now we know whether or not zero matches is allowed
1260 and also whether or not two or more matches is allowed. */
1262 { /* More than one repetition is allowed, so put in at the
1263 end a backward relative jump from `b' to before the next
1264 jump we're going to put in below (which jumps from
1265 laststart to after this jump).
1267 But if we are at the `*' in the exact sequence `.*\n',
1268 insert an unconditional jump backwards to the .,
1269 instead of the beginning of the loop. This way we only
1270 push a failure point once, instead of every time
1271 through the loop. */
1272 assert (p - 1 > pattern);
1274 /* Allocate the space for the jump. */
1275 GET_BUFFER_SPACE (3);
1277 /* We know we are not at the first character of the pattern,
1278 because laststart was nonzero. And we've already
1279 incremented `p', by the way, to be the character after
1280 the `*'. Do we have to do something analogous here
1281 for null bytes, because of RE_DOT_NOT_NULL? */
1282 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1283 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1284 && !(syntax & RE_DOT_NEWLINE))
1285 { /* We have .*\n. */
1286 STORE_JUMP (jump, b, laststart);
1287 keep_string_p = true;
1290 /* Anything else. */
1291 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1293 /* We've added more stuff to the buffer. */
1297 /* On failure, jump from laststart to b + 3, which will be the
1298 end of the buffer after this jump is inserted. */
1299 GET_BUFFER_SPACE (3);
1300 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1308 /* At least one repetition is required, so insert a
1309 `dummy_failure_jump' before the initial
1310 `on_failure_jump' instruction of the loop. This
1311 effects a skip over that instruction the first time
1312 we hit that loop. */
1313 GET_BUFFER_SPACE (3);
1314 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1329 boolean had_char_class = false;
1331 if (p == pend) return REG_EBRACK;
1333 /* Ensure that we have enough space to push a charset: the
1334 opcode, the length count, and the bitset; 34 bytes in all. */
1335 GET_BUFFER_SPACE (34);
1339 /* We test `*p == '^' twice, instead of using an if
1340 statement, so we only need one BUF_PUSH. */
1341 BUF_PUSH (*p == '^' ? charset_not : charset);
1345 /* Remember the first position in the bracket expression. */
1348 /* Push the number of bytes in the bitmap. */
1349 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1351 /* Clear the whole map. */
1352 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1354 /* charset_not matches newline according to a syntax bit. */
1355 if ((re_opcode_t) b[-2] == charset_not
1356 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1357 SET_LIST_BIT ('\n');
1359 /* Read in characters and ranges, setting map bits. */
1362 if (p == pend) return REG_EBRACK;
1366 /* \ might escape characters inside [...] and [^...]. */
1367 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1369 if (p == pend) return REG_EESCAPE;
1376 /* Could be the end of the bracket expression. If it's
1377 not (i.e., when the bracket expression is `[]' so
1378 far), the ']' character bit gets set way below. */
1379 if (c == ']' && p != p1 + 1)
1382 /* Look ahead to see if it's a range when the last thing
1383 was a character class. */
1384 if (had_char_class && c == '-' && *p != ']')
1387 /* Look ahead to see if it's a range when the last thing
1388 was a character: if this is a hyphen not at the
1389 beginning or the end of a list, then it's the range
1392 && !(p - 2 >= pattern && p[-2] == '[')
1393 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1397 = compile_range (&p, pend, translate, syntax, b);
1398 if (ret != REG_NOERROR) return ret;
1401 else if (p[0] == '-' && p[1] != ']')
1402 { /* This handles ranges made up of characters only. */
1405 /* Move past the `-'. */
1408 ret = compile_range (&p, pend, translate, syntax, b);
1409 if (ret != REG_NOERROR) return ret;
1412 /* See if we're at the beginning of a possible character
1415 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1416 { /* Leave room for the null. */
1417 char str[CHAR_CLASS_MAX_LENGTH + 1];
1422 /* If pattern is `[[:'. */
1423 if (p == pend) return REG_EBRACK;
1428 if (c == ':' || c == ']' || p == pend
1429 || c1 == CHAR_CLASS_MAX_LENGTH)
1435 /* If isn't a word bracketed by `[:' and:`]':
1436 undo the ending character, the letters, and leave
1437 the leading `:' and `[' (but set bits for them). */
1438 if (c == ':' && *p == ']')
1441 boolean is_alnum = STREQ (str, "alnum");
1442 boolean is_alpha = STREQ (str, "alpha");
1443 boolean is_blank = STREQ (str, "blank");
1444 boolean is_cntrl = STREQ (str, "cntrl");
1445 boolean is_digit = STREQ (str, "digit");
1446 boolean is_graph = STREQ (str, "graph");
1447 boolean is_lower = STREQ (str, "lower");
1448 boolean is_print = STREQ (str, "print");
1449 boolean is_punct = STREQ (str, "punct");
1450 boolean is_space = STREQ (str, "space");
1451 boolean is_upper = STREQ (str, "upper");
1452 boolean is_xdigit = STREQ (str, "xdigit");
1454 if (!IS_CHAR_CLASS (str)) return REG_ECTYPE;
1456 /* Throw away the ] at the end of the character
1460 if (p == pend) return REG_EBRACK;
1462 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
1464 if ( (is_alnum && isalnum (ch))
1465 || (is_alpha && isalpha (ch))
1466 || (is_blank && isblank (ch))
1467 || (is_cntrl && iscntrl (ch))
1468 || (is_digit && isdigit (ch))
1469 || (is_graph && isgraph (ch))
1470 || (is_lower && islower (ch))
1471 || (is_print && isprint (ch))
1472 || (is_punct && ispunct (ch))
1473 || (is_space && isspace (ch))
1474 || (is_upper && isupper (ch))
1475 || (is_xdigit && isxdigit (ch)))
1478 had_char_class = true;
1487 had_char_class = false;
1492 had_char_class = false;
1497 /* Discard any (non)matching list bytes that are all 0 at the
1498 end of the map. Decrease the map-length byte too. */
1499 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
1507 if (syntax & RE_NO_BK_PARENS)
1514 if (syntax & RE_NO_BK_PARENS)
1521 if (syntax & RE_NEWLINE_ALT)
1528 if (syntax & RE_NO_BK_VBAR)
1535 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
1536 goto handle_interval;
1542 if (p == pend) return REG_EESCAPE;
1544 /* Do not translate the character after the \, so that we can
1545 distinguish, e.g., \B from \b, even if we normally would
1546 translate, e.g., B to b. */
1552 if (syntax & RE_NO_BK_PARENS)
1553 goto normal_backslash;
1559 if (COMPILE_STACK_FULL)
1561 RETALLOC (compile_stack.stack, compile_stack.size << 1,
1562 compile_stack_elt_t);
1563 if (compile_stack.stack == NULL) return REG_ESPACE;
1565 compile_stack.size <<= 1;
1568 /* These are the values to restore when we hit end of this
1569 group. They are all relative offsets, so that if the
1570 whole pattern moves because of realloc, they will still
1572 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
1573 COMPILE_STACK_TOP.fixup_alt_jump
1574 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
1575 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
1576 COMPILE_STACK_TOP.regnum = regnum;
1578 /* We will eventually replace the 0 with the number of
1579 groups inner to this one. But do not push a
1580 start_memory for groups beyond the last one we can
1581 represent in the compiled pattern. */
1582 if (regnum <= MAX_REGNUM)
1584 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
1585 BUF_PUSH_3 (start_memory, regnum, 0);
1588 compile_stack.avail++;
1597 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
1599 if (COMPILE_STACK_EMPTY)
1600 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1601 goto normal_backslash;
1607 { /* Push a dummy failure point at the end of the
1608 alternative for a possible future
1609 `pop_failure_jump' to pop. See comments at
1610 `push_dummy_failure' in `re_match_2'. */
1611 BUF_PUSH (push_dummy_failure);
1613 /* We allocated space for this jump when we assigned
1614 to `fixup_alt_jump', in the `handle_alt' case below. */
1615 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
1618 /* See similar code for backslashed left paren above. */
1619 if (COMPILE_STACK_EMPTY)
1620 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1625 /* Since we just checked for an empty stack above, this
1626 ``can't happen''. */
1627 assert (compile_stack.avail != 0);
1629 /* We don't just want to restore into `regnum', because
1630 later groups should continue to be numbered higher,
1631 as in `(ab)c(de)' -- the second group is #2. */
1632 regnum_t this_group_regnum;
1634 compile_stack.avail--;
1635 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
1637 = COMPILE_STACK_TOP.fixup_alt_jump
1638 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
1640 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
1641 this_group_regnum = COMPILE_STACK_TOP.regnum;
1643 /* We're at the end of the group, so now we know how many
1644 groups were inside this one. */
1645 if (this_group_regnum <= MAX_REGNUM)
1647 unsigned char *inner_group_loc
1648 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
1650 *inner_group_loc = regnum - this_group_regnum;
1651 BUF_PUSH_3 (stop_memory, this_group_regnum,
1652 regnum - this_group_regnum);
1658 case '|': /* `\|'. */
1659 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
1660 goto normal_backslash;
1662 if (syntax & RE_LIMITED_OPS)
1665 /* Insert before the previous alternative a jump which
1666 jumps to this alternative if the former fails. */
1667 GET_BUFFER_SPACE (3);
1668 INSERT_JUMP (on_failure_jump, begalt, b + 6);
1672 /* The alternative before this one has a jump after it
1673 which gets executed if it gets matched. Adjust that
1674 jump so it will jump to this alternative's analogous
1675 jump (put in below, which in turn will jump to the next
1676 (if any) alternative's such jump, etc.). The last such
1677 jump jumps to the correct final destination. A picture:
1683 If we are at `b', then fixup_alt_jump right now points to a
1684 three-byte space after `a'. We'll put in the jump, set
1685 fixup_alt_jump to right after `b', and leave behind three
1686 bytes which we'll fill in when we get to after `c'. */
1689 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
1691 /* Mark and leave space for a jump after this alternative,
1692 to be filled in later either by next alternative or
1693 when know we're at the end of a series of alternatives. */
1695 GET_BUFFER_SPACE (3);
1704 /* If \{ is a literal. */
1705 if (!(syntax & RE_INTERVALS)
1706 /* If we're at `\{' and it's not the open-interval
1708 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
1709 || (p - 2 == pattern && p == pend))
1710 goto normal_backslash;
1714 /* If got here, then the syntax allows intervals. */
1716 /* At least (most) this many matches must be made. */
1717 int lower_bound = -1, upper_bound = -1;
1719 beg_interval = p - 1;
1723 if (syntax & RE_NO_BK_BRACES)
1724 goto unfetch_interval;
1729 GET_UNSIGNED_NUMBER (lower_bound);
1733 GET_UNSIGNED_NUMBER (upper_bound);
1734 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
1737 /* Interval such as `{1}' => match exactly once. */
1738 upper_bound = lower_bound;
1740 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
1741 || lower_bound > upper_bound)
1743 if (syntax & RE_NO_BK_BRACES)
1744 goto unfetch_interval;
1749 if (!(syntax & RE_NO_BK_BRACES))
1751 if (c != '\\') return REG_EBRACE;
1758 if (syntax & RE_NO_BK_BRACES)
1759 goto unfetch_interval;
1764 /* We just parsed a valid interval. */
1766 /* If it's invalid to have no preceding re. */
1769 if (syntax & RE_CONTEXT_INVALID_OPS)
1771 else if (syntax & RE_CONTEXT_INDEP_OPS)
1774 goto unfetch_interval;
1777 /* If the upper bound is zero, don't want to succeed at
1778 all; jump from `laststart' to `b + 3', which will be
1779 the end of the buffer after we insert the jump. */
1780 if (upper_bound == 0)
1782 GET_BUFFER_SPACE (3);
1783 INSERT_JUMP (jump, laststart, b + 3);
1787 /* Otherwise, we have a nontrivial interval. When
1788 we're all done, the pattern will look like:
1789 set_number_at <jump count> <upper bound>
1790 set_number_at <succeed_n count> <lower bound>
1791 succeed_n <after jump addr> <succed_n count>
1793 jump_n <succeed_n addr> <jump count>
1794 (The upper bound and `jump_n' are omitted if
1795 `upper_bound' is 1, though.) */
1797 { /* If the upper bound is > 1, we need to insert
1798 more at the end of the loop. */
1799 unsigned nbytes = 10 + (upper_bound > 1) * 10;
1801 GET_BUFFER_SPACE (nbytes);
1803 /* Initialize lower bound of the `succeed_n', even
1804 though it will be set during matching by its
1805 attendant `set_number_at' (inserted next),
1806 because `re_compile_fastmap' needs to know.
1807 Jump to the `jump_n' we might insert below. */
1808 INSERT_JUMP2 (succeed_n, laststart,
1809 b + 5 + (upper_bound > 1) * 5,
1813 /* Code to initialize the lower bound. Insert
1814 before the `succeed_n'. The `5' is the last two
1815 bytes of this `set_number_at', plus 3 bytes of
1816 the following `succeed_n'. */
1817 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
1820 if (upper_bound > 1)
1821 { /* More than one repetition is allowed, so
1822 append a backward jump to the `succeed_n'
1823 that starts this interval.
1825 When we've reached this during matching,
1826 we'll have matched the interval once, so
1827 jump back only `upper_bound - 1' times. */
1828 STORE_JUMP2 (jump_n, b, laststart + 5,
1832 /* The location we want to set is the second
1833 parameter of the `jump_n'; that is `b-2' as
1834 an absolute address. `laststart' will be
1835 the `set_number_at' we're about to insert;
1836 `laststart+3' the number to set, the source
1837 for the relative address. But we are
1838 inserting into the middle of the pattern --
1839 so everything is getting moved up by 5.
1840 Conclusion: (b - 2) - (laststart + 3) + 5,
1841 i.e., b - laststart.
1843 We insert this at the beginning of the loop
1844 so that if we fail during matching, we'll
1845 reinitialize the bounds. */
1846 insert_op2 (set_number_at, laststart, b - laststart,
1847 upper_bound - 1, b);
1852 beg_interval = NULL;
1857 /* If an invalid interval, match the characters as literals. */
1858 assert (beg_interval);
1860 beg_interval = NULL;
1862 /* normal_char and normal_backslash need `c'. */
1865 if (!(syntax & RE_NO_BK_BRACES))
1867 if (p > pattern && p[-1] == '\\')
1868 goto normal_backslash;
1873 /* There is no way to specify the before_dot and after_dot
1874 operators. rms says this is ok. --karl */
1882 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
1888 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
1895 BUF_PUSH (wordchar);
1901 BUF_PUSH (notwordchar);
1914 BUF_PUSH (wordbound);
1918 BUF_PUSH (notwordbound);
1929 case '1': case '2': case '3': case '4': case '5':
1930 case '6': case '7': case '8': case '9':
1931 if (syntax & RE_NO_BK_REFS)
1939 /* Can't back reference to a subexpression if inside of it. */
1940 if (group_in_compile_stack (compile_stack, c1))
1944 BUF_PUSH_2 (duplicate, c1);
1950 if (syntax & RE_BK_PLUS_QM)
1953 goto normal_backslash;
1957 /* You might think it would be useful for \ to mean
1958 not to translate; but if we don't translate it
1959 it will never match anything. */
1967 /* Expects the character in `c'. */
1969 /* If no exactn currently being built. */
1972 /* If last exactn not at current position. */
1973 || pending_exact + *pending_exact + 1 != b
1975 /* We have only one byte following the exactn for the count. */
1976 || *pending_exact == (1 << BYTEWIDTH) - 1
1978 /* If followed by a repetition operator. */
1979 || *p == '*' || *p == '^'
1980 || ((syntax & RE_BK_PLUS_QM)
1981 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
1982 : (*p == '+' || *p == '?'))
1983 || ((syntax & RE_INTERVALS)
1984 && ((syntax & RE_NO_BK_BRACES)
1986 : (p[0] == '\\' && p[1] == '{'))))
1988 /* Start building a new exactn. */
1992 BUF_PUSH_2 (exactn, 0);
1993 pending_exact = b - 1;
2000 } /* while p != pend */
2003 /* Through the pattern now. */
2006 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2008 if (!COMPILE_STACK_EMPTY)
2011 free (compile_stack.stack);
2013 /* We have succeeded; set the length of the buffer. */
2014 bufp->used = b - bufp->buffer;
2019 DEBUG_PRINT1 ("\nCompiled pattern: ");
2020 print_compiled_pattern (bufp);
2025 } /* regex_compile */
2027 /* Subroutines for `regex_compile'. */
2029 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2032 store_op1 (op, loc, arg)
2037 *loc = (unsigned char) op;
2038 STORE_NUMBER (loc + 1, arg);
2042 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2045 store_op2 (op, loc, arg1, arg2)
2050 *loc = (unsigned char) op;
2051 STORE_NUMBER (loc + 1, arg1);
2052 STORE_NUMBER (loc + 3, arg2);
2056 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2057 for OP followed by two-byte integer parameter ARG. */
2060 insert_op1 (op, loc, arg, end)
2066 register unsigned char *pfrom = end;
2067 register unsigned char *pto = end + 3;
2069 while (pfrom != loc)
2072 store_op1 (op, loc, arg);
2076 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2079 insert_op2 (op, loc, arg1, arg2, end)
2085 register unsigned char *pfrom = end;
2086 register unsigned char *pto = end + 5;
2088 while (pfrom != loc)
2091 store_op2 (op, loc, arg1, arg2);
2095 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2096 after an alternative or a begin-subexpression. We assume there is at
2097 least one character before the ^. */
2100 at_begline_loc_p (pattern, p, syntax)
2101 const char *pattern, *p;
2102 reg_syntax_t syntax;
2104 const char *prev = p - 2;
2105 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2108 /* After a subexpression? */
2109 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2110 /* After an alternative? */
2111 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2115 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2116 at least one character after the $, i.e., `P < PEND'. */
2119 at_endline_loc_p (p, pend, syntax)
2120 const char *p, *pend;
2123 const char *next = p;
2124 boolean next_backslash = *next == '\\';
2125 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2128 /* Before a subexpression? */
2129 (syntax & RE_NO_BK_PARENS ? *next == ')'
2130 : next_backslash && next_next && *next_next == ')')
2131 /* Before an alternative? */
2132 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2133 : next_backslash && next_next && *next_next == '|');
2137 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2138 false if it's not. */
2141 group_in_compile_stack (compile_stack, regnum)
2142 compile_stack_type compile_stack;
2147 for (this_element = compile_stack.avail - 1;
2150 if (compile_stack.stack[this_element].regnum == regnum)
2157 /* Read the ending character of a range (in a bracket expression) from the
2158 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2159 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2160 Then we set the translation of all bits between the starting and
2161 ending characters (inclusive) in the compiled pattern B.
2163 Return an error code.
2165 We use these short variable names so we can use the same macros as
2166 `regex_compile' itself. */
2168 static reg_errcode_t
2169 compile_range (p_ptr, pend, translate, syntax, b)
2170 const char **p_ptr, *pend;
2172 reg_syntax_t syntax;
2177 const char *p = *p_ptr;
2179 /* Even though the pattern is a signed `char *', we need to fetch into
2180 `unsigned char's. Reason: if the high bit of the pattern character
2181 is set, the range endpoints will be negative if we fetch into a
2183 unsigned char range_end;
2184 unsigned char range_start = p[-2];
2189 PATFETCH (range_end);
2191 /* Have to increment the pointer into the pattern string, so the
2192 caller isn't still at the ending character. */
2195 /* If the start is after the end, the range is empty. */
2196 if (range_start > range_end)
2197 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2199 /* Here we see why `this_char' has to be larger than an `unsigned
2200 char' -- the range is inclusive, so if `range_end' == 0xff
2201 (assuming 8-bit characters), we would otherwise go into an infinite
2202 loop, since all characters <= 0xff. */
2203 for (this_char = range_start; this_char <= range_end; this_char++)
2205 SET_LIST_BIT (TRANSLATE (this_char));
2211 /* Failure stack declarations and macros; both re_compile_fastmap and
2212 re_match_2 use a failure stack. These have to be macros because of
2216 /* Number of failure points for which to initially allocate space
2217 when matching. If this number is exceeded, we allocate more
2218 space, so it is not a hard limit. */
2219 #ifndef INIT_FAILURE_ALLOC
2220 #define INIT_FAILURE_ALLOC 5
2223 /* Roughly the maximum number of failure points on the stack. Would be
2224 exactly that if always used MAX_FAILURE_SPACE each time we failed.
2225 This is a variable only so users of regex can assign to it; we never
2226 change it ourselves. */
2227 int re_max_failures = 2000;
2229 typedef const unsigned char *fail_stack_elt_t;
2233 fail_stack_elt_t *stack;
2235 unsigned avail; /* Offset of next open position. */
2238 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
2239 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
2240 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
2241 #define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail])
2244 /* Initialize `fail_stack'. Do `return -2' if the alloc fails. */
2246 #define INIT_FAIL_STACK() \
2248 fail_stack.stack = (fail_stack_elt_t *) \
2249 REGEX_ALLOCATE (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
2251 if (fail_stack.stack == NULL) \
2254 fail_stack.size = INIT_FAILURE_ALLOC; \
2255 fail_stack.avail = 0; \
2259 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
2261 Return 1 if succeeds, and 0 if either ran out of memory
2262 allocating space for it or it was already too large.
2264 REGEX_REALLOCATE requires `destination' be declared. */
2266 #define DOUBLE_FAIL_STACK(fail_stack) \
2267 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
2269 : ((fail_stack).stack = (fail_stack_elt_t *) \
2270 REGEX_REALLOCATE ((fail_stack).stack, \
2271 (fail_stack).size * sizeof (fail_stack_elt_t), \
2272 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
2274 (fail_stack).stack == NULL \
2276 : ((fail_stack).size <<= 1, \
2280 /* Push PATTERN_OP on FAIL_STACK.
2282 Return 1 if was able to do so and 0 if ran out of memory allocating
2284 #define PUSH_PATTERN_OP(pattern_op, fail_stack) \
2285 ((FAIL_STACK_FULL () \
2286 && !DOUBLE_FAIL_STACK (fail_stack)) \
2288 : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \
2291 /* This pushes an item onto the failure stack. Must be a four-byte
2292 value. Assumes the variable `fail_stack'. Probably should only
2293 be called from within `PUSH_FAILURE_POINT'. */
2294 #define PUSH_FAILURE_ITEM(item) \
2295 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) item
2297 /* The complement operation. Assumes `fail_stack' is nonempty. */
2298 #define POP_FAILURE_ITEM() fail_stack.stack[--fail_stack.avail]
2300 /* Used to omit pushing failure point id's when we're not debugging. */
2302 #define DEBUG_PUSH PUSH_FAILURE_ITEM
2303 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_ITEM ()
2305 #define DEBUG_PUSH(item)
2306 #define DEBUG_POP(item_addr)
2310 /* Push the information about the state we will need
2311 if we ever fail back to it.
2313 Requires variables fail_stack, regstart, regend, reg_info, and
2314 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
2317 Does `return FAILURE_CODE' if runs out of memory. */
2319 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
2321 char *destination; \
2322 /* Must be int, so when we don't save any registers, the arithmetic \
2323 of 0 + -1 isn't done as unsigned. */ \
2326 DEBUG_STATEMENT (failure_id++); \
2327 DEBUG_STATEMENT (nfailure_points_pushed++); \
2328 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
2329 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
2330 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
2332 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
2333 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
2335 /* Ensure we have enough space allocated for what we will push. */ \
2336 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
2338 if (!DOUBLE_FAIL_STACK (fail_stack)) \
2339 return failure_code; \
2341 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
2342 (fail_stack).size); \
2343 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
2346 /* Push the info, starting with the registers. */ \
2347 DEBUG_PRINT1 ("\n"); \
2349 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
2352 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
2353 DEBUG_STATEMENT (num_regs_pushed++); \
2355 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2356 PUSH_FAILURE_ITEM (regstart[this_reg]); \
2358 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2359 PUSH_FAILURE_ITEM (regend[this_reg]); \
2361 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
2362 DEBUG_PRINT2 (" match_null=%d", \
2363 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
2364 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
2365 DEBUG_PRINT2 (" matched_something=%d", \
2366 MATCHED_SOMETHING (reg_info[this_reg])); \
2367 DEBUG_PRINT2 (" ever_matched=%d", \
2368 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
2369 DEBUG_PRINT1 ("\n"); \
2370 PUSH_FAILURE_ITEM (reg_info[this_reg].word); \
2373 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
2374 PUSH_FAILURE_ITEM (lowest_active_reg); \
2376 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
2377 PUSH_FAILURE_ITEM (highest_active_reg); \
2379 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
2380 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
2381 PUSH_FAILURE_ITEM (pattern_place); \
2383 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
2384 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
2386 DEBUG_PRINT1 ("'\n"); \
2387 PUSH_FAILURE_ITEM (string_place); \
2389 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
2390 DEBUG_PUSH (failure_id); \
2393 /* This is the number of items that are pushed and popped on the stack
2394 for each register. */
2395 #define NUM_REG_ITEMS 3
2397 /* Individual items aside from the registers. */
2399 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
2401 #define NUM_NONREG_ITEMS 4
2404 /* We push at most this many items on the stack. */
2405 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
2407 /* We actually push this many items. */
2408 #define NUM_FAILURE_ITEMS \
2409 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
2412 /* How many items can still be added to the stack without overflowing it. */
2413 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
2416 /* Pops what PUSH_FAIL_STACK pushes.
2418 We restore into the parameters, all of which should be lvalues:
2419 STR -- the saved data position.
2420 PAT -- the saved pattern position.
2421 LOW_REG, HIGH_REG -- the highest and lowest active registers.
2422 REGSTART, REGEND -- arrays of string positions.
2423 REG_INFO -- array of information about each subexpression.
2425 Also assumes the variables `fail_stack' and (if debugging), `bufp',
2426 `pend', `string1', `size1', `string2', and `size2'. */
2428 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
2430 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
2432 const unsigned char *string_temp; \
2434 assert (!FAIL_STACK_EMPTY ()); \
2436 /* Remove failure points and point to how many regs pushed. */ \
2437 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
2438 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
2439 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
2441 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
2443 DEBUG_POP (&failure_id); \
2444 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
2446 /* If the saved string location is NULL, it came from an \
2447 on_failure_keep_string_jump opcode, and we want to throw away the \
2448 saved NULL, thus retaining our current position in the string. */ \
2449 string_temp = POP_FAILURE_ITEM (); \
2450 if (string_temp != NULL) \
2451 str = (const char *) string_temp; \
2453 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
2454 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
2455 DEBUG_PRINT1 ("'\n"); \
2457 pat = (unsigned char *) POP_FAILURE_ITEM (); \
2458 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
2459 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
2461 /* Restore register info. */ \
2462 high_reg = (unsigned) POP_FAILURE_ITEM (); \
2463 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
2465 low_reg = (unsigned) POP_FAILURE_ITEM (); \
2466 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
2468 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
2470 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
2472 reg_info[this_reg].word = POP_FAILURE_ITEM (); \
2473 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
2475 regend[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2476 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2478 regstart[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2479 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2482 DEBUG_STATEMENT (nfailure_points_popped++); \
2483 } /* POP_FAILURE_POINT */
2485 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2486 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2487 characters can start a string that matches the pattern. This fastmap
2488 is used by re_search to skip quickly over impossible starting points.
2490 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2491 area as BUFP->fastmap.
2493 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2496 Returns 0 if we succeed, -2 if an internal error. */
2499 re_compile_fastmap (bufp)
2500 struct re_pattern_buffer *bufp;
2503 fail_stack_type fail_stack;
2504 #ifndef REGEX_MALLOC
2507 /* We don't push any register information onto the failure stack. */
2508 unsigned num_regs = 0;
2510 register char *fastmap = bufp->fastmap;
2511 unsigned char *pattern = bufp->buffer;
2512 unsigned long size = bufp->used;
2513 const unsigned char *p = pattern;
2514 register unsigned char *pend = pattern + size;
2516 /* Assume that each path through the pattern can be null until
2517 proven otherwise. We set this false at the bottom of switch
2518 statement, to which we get only if a particular path doesn't
2519 match the empty string. */
2520 boolean path_can_be_null = true;
2522 /* We aren't doing a `succeed_n' to begin with. */
2523 boolean succeed_n_p = false;
2525 assert (fastmap != NULL && p != NULL);
2528 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2529 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2530 bufp->can_be_null = 0;
2532 while (p != pend || !FAIL_STACK_EMPTY ())
2536 bufp->can_be_null |= path_can_be_null;
2538 /* Reset for next path. */
2539 path_can_be_null = true;
2541 p = fail_stack.stack[--fail_stack.avail];
2544 /* We should never be about to go beyond the end of the pattern. */
2547 #ifdef SWITCH_ENUM_BUG
2548 switch ((int) ((re_opcode_t) *p++))
2550 switch ((re_opcode_t) *p++)
2554 /* I guess the idea here is to simply not bother with a fastmap
2555 if a backreference is used, since it's too hard to figure out
2556 the fastmap for the corresponding group. Setting
2557 `can_be_null' stops `re_search_2' from using the fastmap, so
2558 that is all we do. */
2560 bufp->can_be_null = 1;
2564 /* Following are the cases which match a character. These end
2573 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2574 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2580 /* Chars beyond end of map must be allowed. */
2581 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2584 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2585 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2591 for (j = 0; j < (1 << BYTEWIDTH); j++)
2592 if (SYNTAX (j) == Sword)
2598 for (j = 0; j < (1 << BYTEWIDTH); j++)
2599 if (SYNTAX (j) != Sword)
2605 /* `.' matches anything ... */
2606 for (j = 0; j < (1 << BYTEWIDTH); j++)
2609 /* ... except perhaps newline. */
2610 if (!(bufp->syntax & RE_DOT_NEWLINE))
2613 /* Return if we have already set `can_be_null'; if we have,
2614 then the fastmap is irrelevant. Something's wrong here. */
2615 else if (bufp->can_be_null)
2618 /* Otherwise, have to check alternative paths. */
2625 for (j = 0; j < (1 << BYTEWIDTH); j++)
2626 if (SYNTAX (j) == (enum syntaxcode) k)
2633 for (j = 0; j < (1 << BYTEWIDTH); j++)
2634 if (SYNTAX (j) != (enum syntaxcode) k)
2639 /* All cases after this match the empty string. These end with
2647 #endif /* not emacs */
2659 case push_dummy_failure:
2664 case pop_failure_jump:
2665 case maybe_pop_jump:
2668 case dummy_failure_jump:
2669 EXTRACT_NUMBER_AND_INCR (j, p);
2674 /* Jump backward implies we just went through the body of a
2675 loop and matched nothing. Opcode jumped to should be
2676 `on_failure_jump' or `succeed_n'. Just treat it like an
2677 ordinary jump. For a * loop, it has pushed its failure
2678 point already; if so, discard that as redundant. */
2679 if ((re_opcode_t) *p != on_failure_jump
2680 && (re_opcode_t) *p != succeed_n)
2684 EXTRACT_NUMBER_AND_INCR (j, p);
2687 /* If what's on the stack is where we are now, pop it. */
2688 if (!FAIL_STACK_EMPTY ()
2689 && fail_stack.stack[fail_stack.avail - 1] == p)
2695 case on_failure_jump:
2696 case on_failure_keep_string_jump:
2697 handle_on_failure_jump:
2698 EXTRACT_NUMBER_AND_INCR (j, p);
2700 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
2701 end of the pattern. We don't want to push such a point,
2702 since when we restore it above, entering the switch will
2703 increment `p' past the end of the pattern. We don't need
2704 to push such a point since we obviously won't find any more
2705 fastmap entries beyond `pend'. Such a pattern can match
2706 the null string, though. */
2709 if (!PUSH_PATTERN_OP (p + j, fail_stack))
2713 bufp->can_be_null = 1;
2717 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
2718 succeed_n_p = false;
2725 /* Get to the number of times to succeed. */
2728 /* Increment p past the n for when k != 0. */
2729 EXTRACT_NUMBER_AND_INCR (k, p);
2733 succeed_n_p = true; /* Spaghetti code alert. */
2734 goto handle_on_failure_jump;
2751 abort (); /* We have listed all the cases. */
2754 /* Getting here means we have found the possible starting
2755 characters for one path of the pattern -- and that the empty
2756 string does not match. We need not follow this path further.
2757 Instead, look at the next alternative (remembered on the
2758 stack), or quit if no more. The test at the top of the loop
2759 does these things. */
2760 path_can_be_null = false;
2764 /* Set `can_be_null' for the last path (also the first path, if the
2765 pattern is empty). */
2766 bufp->can_be_null |= path_can_be_null;
2768 } /* re_compile_fastmap */
2770 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
2771 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
2772 this memory for recording register information. STARTS and ENDS
2773 must be allocated using the malloc library routine, and must each
2774 be at least NUM_REGS * sizeof (regoff_t) bytes long.
2776 If NUM_REGS == 0, then subsequent matches should allocate their own
2779 Unless this function is called, the first search or match using
2780 PATTERN_BUFFER will allocate its own register data, without
2781 freeing the old data. */
2784 re_set_registers (bufp, regs, num_regs, starts, ends)
2785 struct re_pattern_buffer *bufp;
2786 struct re_registers *regs;
2788 regoff_t *starts, *ends;
2792 bufp->regs_allocated = REGS_REALLOCATE;
2793 regs->num_regs = num_regs;
2794 regs->start = starts;
2799 bufp->regs_allocated = REGS_UNALLOCATED;
2801 regs->start = regs->end = (regoff_t) 0;
2805 /* Searching routines. */
2807 /* Like re_search_2, below, but only one string is specified, and
2808 doesn't let you say where to stop matching. */
2811 re_search (bufp, string, size, startpos, range, regs)
2812 struct re_pattern_buffer *bufp;
2814 int size, startpos, range;
2815 struct re_registers *regs;
2817 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
2822 /* Using the compiled pattern in BUFP->buffer, first tries to match the
2823 virtual concatenation of STRING1 and STRING2, starting first at index
2824 STARTPOS, then at STARTPOS + 1, and so on.
2826 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
2828 RANGE is how far to scan while trying to match. RANGE = 0 means try
2829 only at STARTPOS; in general, the last start tried is STARTPOS +
2832 In REGS, return the indices of the virtual concatenation of STRING1
2833 and STRING2 that matched the entire BUFP->buffer and its contained
2836 Do not consider matching one past the index STOP in the virtual
2837 concatenation of STRING1 and STRING2.
2839 We return either the position in the strings at which the match was
2840 found, -1 if no match, or -2 if error (such as failure
2844 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
2845 struct re_pattern_buffer *bufp;
2846 const char *string1, *string2;
2850 struct re_registers *regs;
2854 register char *fastmap = bufp->fastmap;
2855 register char *translate = bufp->translate;
2856 int total_size = size1 + size2;
2857 int endpos = startpos + range;
2859 /* Check for out-of-range STARTPOS. */
2860 if (startpos < 0 || startpos > total_size)
2863 /* Fix up RANGE if it might eventually take us outside
2864 the virtual concatenation of STRING1 and STRING2. */
2866 range = -1 - startpos;
2867 else if (endpos > total_size)
2868 range = total_size - startpos;
2870 /* If the search isn't to be a backwards one, don't waste time in a
2871 search for a pattern that must be anchored. */
2872 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
2880 /* Update the fastmap now if not correct already. */
2881 if (fastmap && !bufp->fastmap_accurate)
2882 if (re_compile_fastmap (bufp) == -2)
2885 /* Loop through the string, looking for a place to start matching. */
2888 /* If a fastmap is supplied, skip quickly over characters that
2889 cannot be the start of a match. If the pattern can match the
2890 null string, however, we don't need to skip characters; we want
2891 the first null string. */
2892 if (fastmap && startpos < total_size && !bufp->can_be_null)
2894 if (range > 0) /* Searching forwards. */
2896 register const char *d;
2897 register int lim = 0;
2900 if (startpos < size1 && startpos + range >= size1)
2901 lim = range - (size1 - startpos);
2903 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
2905 /* Written out as an if-else to avoid testing `translate'
2909 && !fastmap[(unsigned char) translate[*d++]])
2912 while (range > lim && !fastmap[(unsigned char) *d++])
2915 startpos += irange - range;
2917 else /* Searching backwards. */
2919 register char c = (size1 == 0 || startpos >= size1
2920 ? string2[startpos - size1]
2921 : string1[startpos]);
2923 if (!fastmap[(unsigned char) TRANSLATE (c)])
2928 /* If can't match the null string, and that's all we have left, fail. */
2929 if (range >= 0 && startpos == total_size && fastmap
2930 && !bufp->can_be_null)
2933 val = re_match_2 (bufp, string1, size1, string2, size2,
2934 startpos, regs, stop);
2958 /* Declarations and macros for re_match_2. */
2960 static int bcmp_translate ();
2961 static boolean alt_match_null_string_p (),
2962 common_op_match_null_string_p (),
2963 group_match_null_string_p ();
2965 /* Structure for per-register (a.k.a. per-group) information.
2966 This must not be longer than one word, because we push this value
2967 onto the failure stack. Other register information, such as the
2968 starting and ending positions (which are addresses), and the list of
2969 inner groups (which is a bits list) are maintained in separate
2972 We are making a (strictly speaking) nonportable assumption here: that
2973 the compiler will pack our bit fields into something that fits into
2974 the type of `word', i.e., is something that fits into one item on the
2978 fail_stack_elt_t word;
2981 /* This field is one if this group can match the empty string,
2982 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
2983 #define MATCH_NULL_UNSET_VALUE 3
2984 unsigned match_null_string_p : 2;
2985 unsigned is_active : 1;
2986 unsigned matched_something : 1;
2987 unsigned ever_matched_something : 1;
2989 } register_info_type;
2991 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
2992 #define IS_ACTIVE(R) ((R).bits.is_active)
2993 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
2994 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
2997 /* Call this when have matched a real character; it sets `matched' flags
2998 for the subexpressions which we are currently inside. Also records
2999 that those subexprs have matched. */
3000 #define SET_REGS_MATCHED() \
3004 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
3006 MATCHED_SOMETHING (reg_info[r]) \
3007 = EVER_MATCHED_SOMETHING (reg_info[r]) \
3014 /* This converts PTR, a pointer into one of the search strings `string1'
3015 and `string2' into an offset from the beginning of that string. */
3016 #define POINTER_TO_OFFSET(ptr) \
3017 (FIRST_STRING_P (ptr) ? (ptr) - string1 : (ptr) - string2 + size1)
3019 /* Registers are set to a sentinel when they haven't yet matched. */
3020 #define REG_UNSET_VALUE ((char *) -1)
3021 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
3024 /* Macros for dealing with the split strings in re_match_2. */
3026 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3028 /* Call before fetching a character with *d. This switches over to
3029 string2 if necessary. */
3030 #define PREFETCH() \
3033 /* End of string2 => fail. */ \
3034 if (dend == end_match_2) \
3036 /* End of string1 => advance to string2. */ \
3038 dend = end_match_2; \
3042 /* Test if at very beginning or at very end of the virtual concatenation
3043 of `string1' and `string2'. If only one string, it's `string2'. */
3044 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
3045 #define AT_STRINGS_END(d) ((d) == end2)
3048 /* Test if D points to a character which is word-constituent. We have
3049 two special cases to check for: if past the end of string1, look at
3050 the first character in string2; and if before the beginning of
3051 string2, look at the last character in string1. */
3052 #define WORDCHAR_P(d) \
3053 (SYNTAX ((d) == end1 ? *string2 \
3054 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \
3057 /* Test if the character before D and the one at D differ with respect
3058 to being word-constituent. */
3059 #define AT_WORD_BOUNDARY(d) \
3060 (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \
3061 || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
3064 /* Free everything we malloc. */
3066 #define FREE_VAR(var) if (var) free (var); var = NULL
3067 #define FREE_VARIABLES() \
3069 FREE_VAR (fail_stack.stack); \
3070 FREE_VAR (regstart); \
3071 FREE_VAR (regend); \
3072 FREE_VAR (old_regstart); \
3073 FREE_VAR (old_regend); \
3074 FREE_VAR (best_regstart); \
3075 FREE_VAR (best_regend); \
3076 FREE_VAR (reg_info); \
3077 FREE_VAR (reg_dummy); \
3078 FREE_VAR (reg_info_dummy); \
3080 #else /* not REGEX_MALLOC */
3081 /* Some MIPS systems (at least) want this to free alloca'd storage. */
3082 #define FREE_VARIABLES() alloca (0)
3083 #endif /* not REGEX_MALLOC */
3086 /* These values must meet several constraints. They must not be valid
3087 register values; since we have a limit of 255 registers (because
3088 we use only one byte in the pattern for the register number), we can
3089 use numbers larger than 255. They must differ by 1, because of
3090 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3091 be larger than the value for the highest register, so we do not try
3092 to actually save any registers when none are active. */
3093 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3094 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3096 /* Matching routines. */
3098 #ifndef emacs /* Emacs never uses this. */
3099 /* re_match is like re_match_2 except it takes only a single string. */
3102 re_match (bufp, string, size, pos, regs)
3103 struct re_pattern_buffer *bufp;
3106 struct re_registers *regs;
3108 return re_match_2 (bufp, NULL, 0, string, size, pos, regs, size);
3110 #endif /* not emacs */
3113 /* re_match_2 matches the compiled pattern in BUFP against the
3114 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3115 and SIZE2, respectively). We start matching at POS, and stop
3118 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3119 store offsets for the substring each group matched in REGS. See the
3120 documentation for exactly how many groups we fill.
3122 We return -1 if no match, -2 if an internal error (such as the
3123 failure stack overflowing). Otherwise, we return the length of the
3124 matched substring. */
3127 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3128 struct re_pattern_buffer *bufp;
3129 const char *string1, *string2;
3132 struct re_registers *regs;
3135 /* General temporaries. */
3139 /* Just past the end of the corresponding string. */
3140 const char *end1, *end2;
3142 /* Pointers into string1 and string2, just past the last characters in
3143 each to consider matching. */
3144 const char *end_match_1, *end_match_2;
3146 /* Where we are in the data, and the end of the current string. */
3147 const char *d, *dend;
3149 /* Where we are in the pattern, and the end of the pattern. */
3150 unsigned char *p = bufp->buffer;
3151 register unsigned char *pend = p + bufp->used;
3153 /* We use this to map every character in the string. */
3154 char *translate = bufp->translate;
3156 /* Failure point stack. Each place that can handle a failure further
3157 down the line pushes a failure point on this stack. It consists of
3158 restart, regend, and reg_info for all registers corresponding to
3159 the subexpressions we're currently inside, plus the number of such
3160 registers, and, finally, two char *'s. The first char * is where
3161 to resume scanning the pattern; the second one is where to resume
3162 scanning the strings. If the latter is zero, the failure point is
3163 a ``dummy''; if a failure happens and the failure point is a dummy,
3164 it gets discarded and the next next one is tried. */
3165 fail_stack_type fail_stack;
3167 static unsigned failure_id = 0;
3168 unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
3171 /* We fill all the registers internally, independent of what we
3172 return, for use in backreferences. The number here includes
3173 an element for register zero. */
3174 unsigned num_regs = bufp->re_nsub + 1;
3176 /* The currently active registers. */
3177 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3178 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3180 /* Information on the contents of registers. These are pointers into
3181 the input strings; they record just what was matched (on this
3182 attempt) by a subexpression part of the pattern, that is, the
3183 regnum-th regstart pointer points to where in the pattern we began
3184 matching and the regnum-th regend points to right after where we
3185 stopped matching the regnum-th subexpression. (The zeroth register
3186 keeps track of what the whole pattern matches.) */
3187 const char **regstart, **regend;
3189 /* If a group that's operated upon by a repetition operator fails to
3190 match anything, then the register for its start will need to be
3191 restored because it will have been set to wherever in the string we
3192 are when we last see its open-group operator. Similarly for a
3194 const char **old_regstart, **old_regend;
3196 /* The is_active field of reg_info helps us keep track of which (possibly
3197 nested) subexpressions we are currently in. The matched_something
3198 field of reg_info[reg_num] helps us tell whether or not we have
3199 matched any of the pattern so far this time through the reg_num-th
3200 subexpression. These two fields get reset each time through any
3201 loop their register is in. */
3202 register_info_type *reg_info;
3204 /* The following record the register info as found in the above
3205 variables when we find a match better than any we've seen before.
3206 This happens as we backtrack through the failure points, which in
3207 turn happens only if we have not yet matched the entire string. */
3208 unsigned best_regs_set = false;
3209 const char **best_regstart, **best_regend;
3211 /* Logically, this is `best_regend[0]'. But we don't want to have to
3212 allocate space for that if we're not allocating space for anything
3213 else (see below). Also, we never need info about register 0 for
3214 any of the other register vectors, and it seems rather a kludge to
3215 treat `best_regend' differently than the rest. So we keep track of
3216 the end of the best match so far in a separate variable. We
3217 initialize this to NULL so that when we backtrack the first time
3218 and need to test it, it's not garbage. */
3219 const char *match_end = NULL;
3221 /* Used when we pop values we don't care about. */
3222 const char **reg_dummy;
3223 register_info_type *reg_info_dummy;
3226 /* Counts the total number of registers pushed. */
3227 unsigned num_regs_pushed = 0;
3230 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3234 /* Do not bother to initialize all the register variables if there are
3235 no groups in the pattern, as it takes a fair amount of time. If
3236 there are groups, we include space for register 0 (the whole
3237 pattern), even though we never use it, since it simplifies the
3238 array indexing. We should fix this. */
3241 regstart = REGEX_TALLOC (num_regs, const char *);
3242 regend = REGEX_TALLOC (num_regs, const char *);
3243 old_regstart = REGEX_TALLOC (num_regs, const char *);
3244 old_regend = REGEX_TALLOC (num_regs, const char *);
3245 best_regstart = REGEX_TALLOC (num_regs, const char *);
3246 best_regend = REGEX_TALLOC (num_regs, const char *);
3247 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3248 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3249 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3251 if (!(regstart && regend && old_regstart && old_regend && reg_info
3252 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3261 /* We must initialize all our variables to NULL, so that
3262 `FREE_VARIABLES' doesn't try to free them. */
3263 regstart = regend = old_regstart = old_regend = best_regstart
3264 = best_regend = reg_dummy = NULL;
3265 reg_info = reg_info_dummy = (register_info_type *) NULL;
3267 #endif /* REGEX_MALLOC */
3269 /* The starting position is bogus. */
3270 if (pos < 0 || pos > size1 + size2)
3276 /* Initialize subexpression text positions to -1 to mark ones that no
3277 start_memory/stop_memory has been seen for. Also initialize the
3278 register information struct. */
3279 for (mcnt = 1; mcnt < num_regs; mcnt++)
3281 regstart[mcnt] = regend[mcnt]
3282 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3284 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3285 IS_ACTIVE (reg_info[mcnt]) = 0;
3286 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3287 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3290 /* We move `string1' into `string2' if the latter's empty -- but not if
3291 `string1' is null. */
3292 if (size2 == 0 && string1 != NULL)
3299 end1 = string1 + size1;
3300 end2 = string2 + size2;
3302 /* Compute where to stop matching, within the two strings. */
3305 end_match_1 = string1 + stop;
3306 end_match_2 = string2;
3311 end_match_2 = string2 + stop - size1;
3314 /* `p' scans through the pattern as `d' scans through the data.
3315 `dend' is the end of the input string that `d' points within. `d'
3316 is advanced into the following input string whenever necessary, but
3317 this happens before fetching; therefore, at the beginning of the
3318 loop, `d' can be pointing at the end of a string, but it cannot
3320 if (size1 > 0 && pos <= size1)
3327 d = string2 + pos - size1;
3331 DEBUG_PRINT1 ("The compiled pattern is: ");
3332 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3333 DEBUG_PRINT1 ("The string to match is: `");
3334 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3335 DEBUG_PRINT1 ("'\n");
3337 /* This loops over pattern commands. It exits by returning from the
3338 function if the match is complete, or it drops through if the match
3339 fails at this starting point in the input data. */
3342 DEBUG_PRINT2 ("\n0x%x: ", p);
3345 { /* End of pattern means we might have succeeded. */
3346 DEBUG_PRINT1 ("end of pattern ... ");
3348 /* If we haven't matched the entire string, and we want the
3349 longest match, try backtracking. */
3350 if (d != end_match_2)
3352 DEBUG_PRINT1 ("backtracking.\n");
3354 if (!FAIL_STACK_EMPTY ())
3355 { /* More failure points to try. */
3356 boolean same_str_p = (FIRST_STRING_P (match_end)
3357 == MATCHING_IN_FIRST_STRING);
3359 /* If exceeds best match so far, save it. */
3361 || (same_str_p && d > match_end)
3362 || (!same_str_p && !MATCHING_IN_FIRST_STRING))
3364 best_regs_set = true;
3367 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3369 for (mcnt = 1; mcnt < num_regs; mcnt++)
3371 best_regstart[mcnt] = regstart[mcnt];
3372 best_regend[mcnt] = regend[mcnt];
3378 /* If no failure points, don't restore garbage. */
3379 else if (best_regs_set)
3382 /* Restore best match. It may happen that `dend ==
3383 end_match_1' while the restored d is in string2.
3384 For example, the pattern `x.*y.*z' against the
3385 strings `x-' and `y-z-', if the two strings are
3386 not consecutive in memory. */
3387 DEBUG_PRINT1 ("Restoring best registers.\n");
3390 dend = ((d >= string1 && d <= end1)
3391 ? end_match_1 : end_match_2);
3393 for (mcnt = 1; mcnt < num_regs; mcnt++)
3395 regstart[mcnt] = best_regstart[mcnt];
3396 regend[mcnt] = best_regend[mcnt];
3399 } /* d != end_match_2 */
3401 DEBUG_PRINT1 ("Accepting match.\n");
3403 /* If caller wants register contents data back, do it. */
3404 if (regs && !bufp->no_sub)
3406 /* Have the register data arrays been allocated? */
3407 if (bufp->regs_allocated == REGS_UNALLOCATED)
3408 { /* No. So allocate them with malloc. We need one
3409 extra element beyond `num_regs' for the `-1' marker
3411 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3412 regs->start = TALLOC (regs->num_regs, regoff_t);
3413 regs->end = TALLOC (regs->num_regs, regoff_t);
3414 if (regs->start == NULL || regs->end == NULL)
3416 bufp->regs_allocated = REGS_REALLOCATE;
3418 else if (bufp->regs_allocated == REGS_REALLOCATE)
3419 { /* Yes. If we need more elements than were already
3420 allocated, reallocate them. If we need fewer, just
3422 if (regs->num_regs < num_regs + 1)
3424 regs->num_regs = num_regs + 1;
3425 RETALLOC (regs->start, regs->num_regs, regoff_t);
3426 RETALLOC (regs->end, regs->num_regs, regoff_t);
3427 if (regs->start == NULL || regs->end == NULL)
3432 assert (bufp->regs_allocated == REGS_FIXED);
3434 /* Convert the pointer data in `regstart' and `regend' to
3435 indices. Register zero has to be set differently,
3436 since we haven't kept track of any info for it. */
3437 if (regs->num_regs > 0)
3439 regs->start[0] = pos;
3440 regs->end[0] = (MATCHING_IN_FIRST_STRING ? d - string1
3441 : d - string2 + size1);
3444 /* Go through the first `min (num_regs, regs->num_regs)'
3445 registers, since that is all we initialized. */
3446 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3448 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3449 regs->start[mcnt] = regs->end[mcnt] = -1;
3452 regs->start[mcnt] = POINTER_TO_OFFSET (regstart[mcnt]);
3453 regs->end[mcnt] = POINTER_TO_OFFSET (regend[mcnt]);
3457 /* If the regs structure we return has more elements than
3458 were in the pattern, set the extra elements to -1. If
3459 we (re)allocated the registers, this is the case,
3460 because we always allocate enough to have at least one
3462 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3463 regs->start[mcnt] = regs->end[mcnt] = -1;
3464 } /* regs && !bufp->no_sub */
3467 DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
3468 nfailure_points_pushed, nfailure_points_popped,
3469 nfailure_points_pushed - nfailure_points_popped);
3470 DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
3472 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3476 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3481 /* Otherwise match next pattern command. */
3482 #ifdef SWITCH_ENUM_BUG
3483 switch ((int) ((re_opcode_t) *p++))
3485 switch ((re_opcode_t) *p++)
3488 /* Ignore these. Used to ignore the n of succeed_n's which
3489 currently have n == 0. */
3491 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3495 /* Match the next n pattern characters exactly. The following
3496 byte in the pattern defines n, and the n bytes after that
3497 are the characters to match. */
3500 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3502 /* This is written out as an if-else so we don't waste time
3503 testing `translate' inside the loop. */
3509 if (translate[(unsigned char) *d++] != (char) *p++)
3519 if (*d++ != (char) *p++) goto fail;
3523 SET_REGS_MATCHED ();
3527 /* Match any character except possibly a newline or a null. */
3529 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3533 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3534 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3537 SET_REGS_MATCHED ();
3538 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3546 register unsigned char c;
3547 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3549 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3552 c = TRANSLATE (*d); /* The character to match. */
3554 /* Cast to `unsigned' instead of `unsigned char' in case the
3555 bit list is a full 32 bytes long. */
3556 if (c < (unsigned) (*p * BYTEWIDTH)
3557 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3562 if (!not) goto fail;
3564 SET_REGS_MATCHED ();
3570 /* The beginning of a group is represented by start_memory.
3571 The arguments are the register number in the next byte, and the
3572 number of groups inner to this one in the next. The text
3573 matched within the group is recorded (in the internal
3574 registers data structure) under the register number. */
3576 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3578 /* Find out if this group can match the empty string. */
3579 p1 = p; /* To send to group_match_null_string_p. */
3581 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3582 REG_MATCH_NULL_STRING_P (reg_info[*p])
3583 = group_match_null_string_p (&p1, pend, reg_info);
3585 /* Save the position in the string where we were the last time
3586 we were at this open-group operator in case the group is
3587 operated upon by a repetition operator, e.g., with `(a*)*b'
3588 against `ab'; then we want to ignore where we are now in
3589 the string in case this attempt to match fails. */
3590 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3591 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3593 DEBUG_PRINT2 (" old_regstart: %d\n",
3594 POINTER_TO_OFFSET (old_regstart[*p]));
3597 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
3599 IS_ACTIVE (reg_info[*p]) = 1;
3600 MATCHED_SOMETHING (reg_info[*p]) = 0;
3602 /* This is the new highest active register. */
3603 highest_active_reg = *p;
3605 /* If nothing was active before, this is the new lowest active
3607 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3608 lowest_active_reg = *p;
3610 /* Move past the register number and inner group count. */
3615 /* The stop_memory opcode represents the end of a group. Its
3616 arguments are the same as start_memory's: the register
3617 number, and the number of inner groups. */
3619 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
3621 /* We need to save the string position the last time we were at
3622 this close-group operator in case the group is operated
3623 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
3624 against `aba'; then we want to ignore where we are now in
3625 the string in case this attempt to match fails. */
3626 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3627 ? REG_UNSET (regend[*p]) ? d : regend[*p]
3629 DEBUG_PRINT2 (" old_regend: %d\n",
3630 POINTER_TO_OFFSET (old_regend[*p]));
3633 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
3635 /* This register isn't active anymore. */
3636 IS_ACTIVE (reg_info[*p]) = 0;
3638 /* If this was the only register active, nothing is active
3640 if (lowest_active_reg == highest_active_reg)
3642 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3643 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3646 { /* We must scan for the new highest active register, since
3647 it isn't necessarily one less than now: consider
3648 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
3649 new highest active register is 1. */
3650 unsigned char r = *p - 1;
3651 while (r > 0 && !IS_ACTIVE (reg_info[r]))
3654 /* If we end up at register zero, that means that we saved
3655 the registers as the result of an `on_failure_jump', not
3656 a `start_memory', and we jumped to past the innermost
3657 `stop_memory'. For example, in ((.)*) we save
3658 registers 1 and 2 as a result of the *, but when we pop
3659 back to the second ), we are at the stop_memory 1.
3660 Thus, nothing is active. */
3663 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3664 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3667 highest_active_reg = r;
3670 /* If just failed to match something this time around with a
3671 group that's operated on by a repetition operator, try to
3672 force exit from the ``loop'', and restore the register
3673 information for this group that we had before trying this
3675 if ((!MATCHED_SOMETHING (reg_info[*p])
3676 || (re_opcode_t) p[-3] == start_memory)
3679 boolean is_a_jump_n = false;
3683 switch ((re_opcode_t) *p1++)
3687 case pop_failure_jump:
3688 case maybe_pop_jump:
3690 case dummy_failure_jump:
3691 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3701 /* If the next operation is a jump backwards in the pattern
3702 to an on_failure_jump right before the start_memory
3703 corresponding to this stop_memory, exit from the loop
3704 by forcing a failure after pushing on the stack the
3705 on_failure_jump's jump in the pattern, and d. */
3706 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
3707 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
3709 /* If this group ever matched anything, then restore
3710 what its registers were before trying this last
3711 failed match, e.g., with `(a*)*b' against `ab' for
3712 regstart[1], and, e.g., with `((a*)*(b*)*)*'
3713 against `aba' for regend[3].
3715 Also restore the registers for inner groups for,
3716 e.g., `((a*)(b*))*' against `aba' (register 3 would
3717 otherwise get trashed). */
3719 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
3723 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
3725 /* Restore this and inner groups' (if any) registers. */
3726 for (r = *p; r < *p + *(p + 1); r++)
3728 regstart[r] = old_regstart[r];
3730 /* xx why this test? */
3731 if ((int) old_regend[r] >= (int) regstart[r])
3732 regend[r] = old_regend[r];
3736 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3737 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
3743 /* Move past the register number and the inner group count. */
3748 /* \<digit> has been turned into a `duplicate' command which is
3749 followed by the numeric value of <digit> as the register number. */
3752 register const char *d2, *dend2;
3753 int regno = *p++; /* Get which register to match against. */
3754 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
3756 /* Can't back reference a group which we've never matched. */
3757 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
3760 /* Where in input to try to start matching. */
3761 d2 = regstart[regno];
3763 /* Where to stop matching; if both the place to start and
3764 the place to stop matching are in the same string, then
3765 set to the place to stop, otherwise, for now have to use
3766 the end of the first string. */
3768 dend2 = ((FIRST_STRING_P (regstart[regno])
3769 == FIRST_STRING_P (regend[regno]))
3770 ? regend[regno] : end_match_1);
3773 /* If necessary, advance to next segment in register
3777 if (dend2 == end_match_2) break;
3778 if (dend2 == regend[regno]) break;
3780 /* End of string1 => advance to string2. */
3782 dend2 = regend[regno];
3784 /* At end of register contents => success */
3785 if (d2 == dend2) break;
3787 /* If necessary, advance to next segment in data. */
3790 /* How many characters left in this segment to match. */
3793 /* Want how many consecutive characters we can match in
3794 one shot, so, if necessary, adjust the count. */
3795 if (mcnt > dend2 - d2)
3798 /* Compare that many; failure if mismatch, else move
3801 ? bcmp_translate (d, d2, mcnt, translate)
3802 : bcmp (d, d2, mcnt))
3804 d += mcnt, d2 += mcnt;
3810 /* begline matches the empty string at the beginning of the string
3811 (unless `not_bol' is set in `bufp'), and, if
3812 `newline_anchor' is set, after newlines. */
3814 DEBUG_PRINT1 ("EXECUTING begline.\n");
3816 if (AT_STRINGS_BEG (d))
3818 if (!bufp->not_bol) break;
3820 else if (d[-1] == '\n' && bufp->newline_anchor)
3824 /* In all other cases, we fail. */
3828 /* endline is the dual of begline. */
3830 DEBUG_PRINT1 ("EXECUTING endline.\n");
3832 if (AT_STRINGS_END (d))
3834 if (!bufp->not_eol) break;
3837 /* We have to ``prefetch'' the next character. */
3838 else if ((d == end1 ? *string2 : *d) == '\n'
3839 && bufp->newline_anchor)
3846 /* Match at the very beginning of the data. */
3848 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
3849 if (AT_STRINGS_BEG (d))
3854 /* Match at the very end of the data. */
3856 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
3857 if (AT_STRINGS_END (d))
3862 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
3863 pushes NULL as the value for the string on the stack. Then
3864 `pop_failure_point' will keep the current value for the
3865 string, instead of restoring it. To see why, consider
3866 matching `foo\nbar' against `.*\n'. The .* matches the foo;
3867 then the . fails against the \n. But the next thing we want
3868 to do is match the \n against the \n; if we restored the
3869 string value, we would be back at the foo.
3871 Because this is used only in specific cases, we don't need to
3872 check all the things that `on_failure_jump' does, to make
3873 sure the right things get saved on the stack. Hence we don't
3874 share its code. The only reason to push anything on the
3875 stack at all is that otherwise we would have to change
3876 `anychar's code to do something besides goto fail in this
3877 case; that seems worse than this. */
3878 case on_failure_keep_string_jump:
3879 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
3881 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3882 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
3884 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
3888 /* Uses of on_failure_jump:
3890 Each alternative starts with an on_failure_jump that points
3891 to the beginning of the next alternative. Each alternative
3892 except the last ends with a jump that in effect jumps past
3893 the rest of the alternatives. (They really jump to the
3894 ending jump of the following alternative, because tensioning
3895 these jumps is a hassle.)
3897 Repeats start with an on_failure_jump that points past both
3898 the repetition text and either the following jump or
3899 pop_failure_jump back to this on_failure_jump. */
3900 case on_failure_jump:
3902 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
3904 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3905 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
3907 /* If this on_failure_jump comes right before a group (i.e.,
3908 the original * applied to a group), save the information
3909 for that group and all inner ones, so that if we fail back
3910 to this point, the group's information will be correct.
3911 For example, in \(a*\)*\1, we need the preceding group,
3912 and in \(\(a*\)b*\)\2, we need the inner group. */
3914 /* We can't use `p' to check ahead because we push
3915 a failure point to `p + mcnt' after we do this. */
3918 /* We need to skip no_op's before we look for the
3919 start_memory in case this on_failure_jump is happening as
3920 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
3922 while (p1 < pend && (re_opcode_t) *p1 == no_op)
3925 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
3927 /* We have a new highest active register now. This will
3928 get reset at the start_memory we are about to get to,
3929 but we will have saved all the registers relevant to
3930 this repetition op, as described above. */
3931 highest_active_reg = *(p1 + 1) + *(p1 + 2);
3932 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3933 lowest_active_reg = *(p1 + 1);
3936 DEBUG_PRINT1 (":\n");
3937 PUSH_FAILURE_POINT (p + mcnt, d, -2);
3941 /* A smart repeat ends with `maybe_pop_jump'.
3942 We change it to either `pop_failure_jump' or `jump'. */
3943 case maybe_pop_jump:
3944 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3945 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
3947 register unsigned char *p2 = p;
3949 /* Compare the beginning of the repeat with what in the
3950 pattern follows its end. If we can establish that there
3951 is nothing that they would both match, i.e., that we
3952 would have to backtrack because of (as in, e.g., `a*a')
3953 then we can change to pop_failure_jump, because we'll
3954 never have to backtrack.
3956 This is not true in the case of alternatives: in
3957 `(a|ab)*' we do need to backtrack to the `ab' alternative
3958 (e.g., if the string was `ab'). But instead of trying to
3959 detect that here, the alternative has put on a dummy
3960 failure point which is what we will end up popping. */
3962 /* Skip over open/close-group commands. */
3963 while (p2 + 2 < pend
3964 && ((re_opcode_t) *p2 == stop_memory
3965 || (re_opcode_t) *p2 == start_memory))
3966 p2 += 3; /* Skip over args, too. */
3968 /* If we're at the end of the pattern, we can change. */
3970 { /* But if we're also at the end of the string, we might
3971 as well skip changing anything. For example, in `a+'
3972 against `a', we'll have already matched the `a', and
3973 I don't see the the point of changing the opcode,
3974 popping the failure point, finding out it fails, and
3975 then going into our endgame. */
3979 DEBUG_PRINT1 (" End of pattern & string => done.\n");
3983 p[-3] = (unsigned char) pop_failure_jump;
3984 DEBUG_PRINT1 (" End of pattern => pop_failure_jump.\n");
3987 else if ((re_opcode_t) *p2 == exactn
3988 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
3990 register unsigned char c
3991 = *p2 == (unsigned char) endline ? '\n' : p2[2];
3994 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
3995 to the `maybe_finalize_jump' of this case. Examine what
3997 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
3999 p[-3] = (unsigned char) pop_failure_jump;
4000 DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n",
4004 else if ((re_opcode_t) p1[3] == charset
4005 || (re_opcode_t) p1[3] == charset_not)
4007 int not = (re_opcode_t) p1[3] == charset_not;
4009 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
4010 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
4013 /* `not' is equal to 1 if c would match, which means
4014 that we can't change to pop_failure_jump. */
4017 p[-3] = (unsigned char) pop_failure_jump;
4018 DEBUG_PRINT1 (" No match => pop_failure_jump.\n");
4023 p -= 2; /* Point at relative address again. */
4024 if ((re_opcode_t) p[-1] != pop_failure_jump)
4026 p[-1] = (unsigned char) jump;
4027 DEBUG_PRINT1 (" Match => jump.\n");
4028 goto unconditional_jump;
4030 /* Note fall through. */
4033 /* The end of a simple repeat has a pop_failure_jump back to
4034 its matching on_failure_jump, where the latter will push a
4035 failure point. The pop_failure_jump takes off failure
4036 points put on by this pop_failure_jump's matching
4037 on_failure_jump; we got through the pattern to here from the
4038 matching on_failure_jump, so didn't fail. */
4039 case pop_failure_jump:
4041 /* We need to pass separate storage for the lowest and
4042 highest registers, even though we don't care about the
4043 actual values. Otherwise, we will restore only one
4044 register from the stack, since lowest will == highest in
4045 `pop_failure_point'. */
4046 unsigned dummy_low_reg, dummy_high_reg;
4047 unsigned char *pdummy;
4050 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4051 POP_FAILURE_POINT (sdummy, pdummy,
4052 dummy_low_reg, dummy_high_reg,
4053 reg_dummy, reg_dummy, reg_info_dummy);
4055 /* Note fall through. */
4058 /* Unconditionally jump (without popping any failure points). */
4061 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4062 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4063 p += mcnt; /* Do the jump. */
4064 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4068 /* We need this opcode so we can detect where alternatives end
4069 in `group_match_null_string_p' et al. */
4071 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4072 goto unconditional_jump;
4075 /* Normally, the on_failure_jump pushes a failure point, which
4076 then gets popped at pop_failure_jump. We will end up at
4077 pop_failure_jump, also, and with a pattern of, say, `a+', we
4078 are skipping over the on_failure_jump, so we have to push
4079 something meaningless for pop_failure_jump to pop. */
4080 case dummy_failure_jump:
4081 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4082 /* It doesn't matter what we push for the string here. What
4083 the code at `fail' tests is the value for the pattern. */
4084 PUSH_FAILURE_POINT (0, 0, -2);
4085 goto unconditional_jump;
4088 /* At the end of an alternative, we need to push a dummy failure
4089 point in case we are followed by a `pop_failure_jump', because
4090 we don't want the failure point for the alternative to be
4091 popped. For example, matching `(a|ab)*' against `aab'
4092 requires that we match the `ab' alternative. */
4093 case push_dummy_failure:
4094 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4095 /* See comments just above at `dummy_failure_jump' about the
4097 PUSH_FAILURE_POINT (0, 0, -2);
4100 /* Have to succeed matching what follows at least n times.
4101 After that, handle like `on_failure_jump'. */
4103 EXTRACT_NUMBER (mcnt, p + 2);
4104 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4107 /* Originally, this is how many times we HAVE to succeed. */
4112 STORE_NUMBER_AND_INCR (p, mcnt);
4113 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4117 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4118 p[2] = (unsigned char) no_op;
4119 p[3] = (unsigned char) no_op;
4125 EXTRACT_NUMBER (mcnt, p + 2);
4126 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4128 /* Originally, this is how many times we CAN jump. */
4132 STORE_NUMBER (p + 2, mcnt);
4133 goto unconditional_jump;
4135 /* If don't have to jump any more, skip over the rest of command. */
4142 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4144 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4146 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4147 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4148 STORE_NUMBER (p1, mcnt);
4153 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4154 if (AT_WORD_BOUNDARY (d))
4159 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4160 if (AT_WORD_BOUNDARY (d))
4165 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4166 if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
4171 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4172 if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
4173 && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
4180 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4181 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4186 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4187 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4192 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4193 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4196 #else /* not emacs19 */
4198 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4199 if (PTR_CHAR_POS ((unsigned char *) d) + 1 != point)
4202 #endif /* not emacs19 */
4205 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4210 DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
4214 if (SYNTAX (*d++) != (enum syntaxcode) mcnt)
4216 SET_REGS_MATCHED ();
4220 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4222 goto matchnotsyntax;
4225 DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
4229 if (SYNTAX (*d++) == (enum syntaxcode) mcnt)
4231 SET_REGS_MATCHED ();
4234 #else /* not emacs */
4236 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4238 if (!WORDCHAR_P (d))
4240 SET_REGS_MATCHED ();
4245 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4249 SET_REGS_MATCHED ();
4252 #endif /* not emacs */
4257 continue; /* Successfully executed one pattern command; keep going. */
4260 /* We goto here if a matching operation fails. */
4262 if (!FAIL_STACK_EMPTY ())
4263 { /* A restart point is known. Restore to that state. */
4264 DEBUG_PRINT1 ("\nFAIL:\n");
4265 POP_FAILURE_POINT (d, p,
4266 lowest_active_reg, highest_active_reg,
4267 regstart, regend, reg_info);
4269 /* If this failure point is a dummy, try the next one. */
4273 /* If we failed to the end of the pattern, don't examine *p. */
4277 boolean is_a_jump_n = false;
4279 /* If failed to a backwards jump that's part of a repetition
4280 loop, need to pop this failure point and use the next one. */
4281 switch ((re_opcode_t) *p)
4285 case maybe_pop_jump:
4286 case pop_failure_jump:
4289 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4292 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4294 && (re_opcode_t) *p1 == on_failure_jump))
4302 if (d >= string1 && d <= end1)
4306 break; /* Matching at this starting point really fails. */
4310 goto restore_best_regs;
4314 return -1; /* Failure to match. */
4317 /* Subroutine definitions for re_match_2. */
4320 /* We are passed P pointing to a register number after a start_memory.
4322 Return true if the pattern up to the corresponding stop_memory can
4323 match the empty string, and false otherwise.
4325 If we find the matching stop_memory, sets P to point to one past its number.
4326 Otherwise, sets P to an undefined byte less than or equal to END.
4328 We don't handle duplicates properly (yet). */
4331 group_match_null_string_p (p, end, reg_info)
4332 unsigned char **p, *end;
4333 register_info_type *reg_info;
4336 /* Point to after the args to the start_memory. */
4337 unsigned char *p1 = *p + 2;
4341 /* Skip over opcodes that can match nothing, and return true or
4342 false, as appropriate, when we get to one that can't, or to the
4343 matching stop_memory. */
4345 switch ((re_opcode_t) *p1)
4347 /* Could be either a loop or a series of alternatives. */
4348 case on_failure_jump:
4350 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4352 /* If the next operation is not a jump backwards in the
4357 /* Go through the on_failure_jumps of the alternatives,
4358 seeing if any of the alternatives cannot match nothing.
4359 The last alternative starts with only a jump,
4360 whereas the rest start with on_failure_jump and end
4361 with a jump, e.g., here is the pattern for `a|b|c':
4363 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4364 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4367 So, we have to first go through the first (n-1)
4368 alternatives and then deal with the last one separately. */
4371 /* Deal with the first (n-1) alternatives, which start
4372 with an on_failure_jump (see above) that jumps to right
4373 past a jump_past_alt. */
4375 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4377 /* `mcnt' holds how many bytes long the alternative
4378 is, including the ending `jump_past_alt' and
4381 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4385 /* Move to right after this alternative, including the
4389 /* Break if it's the beginning of an n-th alternative
4390 that doesn't begin with an on_failure_jump. */
4391 if ((re_opcode_t) *p1 != on_failure_jump)
4394 /* Still have to check that it's not an n-th
4395 alternative that starts with an on_failure_jump. */
4397 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4398 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4400 /* Get to the beginning of the n-th alternative. */
4406 /* Deal with the last alternative: go back and get number
4407 of the `jump_past_alt' just before it. `mcnt' contains
4408 the length of the alternative. */
4409 EXTRACT_NUMBER (mcnt, p1 - 2);
4411 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4414 p1 += mcnt; /* Get past the n-th alternative. */
4420 assert (p1[1] == **p);
4426 if (!common_op_match_null_string_p (&p1, end, reg_info))
4429 } /* while p1 < end */
4432 } /* group_match_null_string_p */
4435 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4436 It expects P to be the first byte of a single alternative and END one
4437 byte past the last. The alternative can contain groups. */
4440 alt_match_null_string_p (p, end, reg_info)
4441 unsigned char *p, *end;
4442 register_info_type *reg_info;
4445 unsigned char *p1 = p;
4449 /* Skip over opcodes that can match nothing, and break when we get
4450 to one that can't. */
4452 switch ((re_opcode_t) *p1)
4455 case on_failure_jump:
4457 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4462 if (!common_op_match_null_string_p (&p1, end, reg_info))
4465 } /* while p1 < end */
4468 } /* alt_match_null_string_p */
4471 /* Deals with the ops common to group_match_null_string_p and
4472 alt_match_null_string_p.
4474 Sets P to one after the op and its arguments, if any. */
4477 common_op_match_null_string_p (p, end, reg_info)
4478 unsigned char **p, *end;
4479 register_info_type *reg_info;
4484 unsigned char *p1 = *p;
4486 switch ((re_opcode_t) *p1++)
4506 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
4507 ret = group_match_null_string_p (&p1, end, reg_info);
4509 /* Have to set this here in case we're checking a group which
4510 contains a group and a back reference to it. */
4512 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
4513 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
4519 /* If this is an optimized succeed_n for zero times, make the jump. */
4521 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4529 /* Get to the number of times to succeed. */
4531 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4536 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4544 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
4552 /* All other opcodes mean we cannot match the empty string. */
4558 } /* common_op_match_null_string_p */
4561 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
4562 bytes; nonzero otherwise. */
4565 bcmp_translate (s1, s2, len, translate)
4566 unsigned char *s1, *s2;
4570 register unsigned char *p1 = s1, *p2 = s2;
4573 if (translate[*p1++] != translate[*p2++]) return 1;
4579 /* Entry points for GNU code. */
4581 /* re_compile_pattern is the GNU regular expression compiler: it
4582 compiles PATTERN (of length SIZE) and puts the result in BUFP.
4583 Returns 0 if the pattern was valid, otherwise an error string.
4585 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
4586 are set in BUFP on entry.
4588 We call regex_compile to do the actual compilation. */
4591 re_compile_pattern (pattern, length, bufp)
4592 const char *pattern;
4594 struct re_pattern_buffer *bufp;
4598 /* GNU code is written to assume at least RE_NREGS registers will be set
4599 (and at least one extra will be -1). */
4600 bufp->regs_allocated = REGS_UNALLOCATED;
4602 /* And GNU code determines whether or not to get register information
4603 by passing null for the REGS argument to re_match, etc., not by
4607 /* Match anchors at newline. */
4608 bufp->newline_anchor = 1;
4610 ret = regex_compile (pattern, length, re_syntax_options, bufp);
4612 return re_error_msg[(int) ret];
4615 /* Entry points compatible with 4.2 BSD regex library. We don't define
4616 them if this is an Emacs or POSIX compilation. */
4618 #if !defined (emacs) && !defined (_POSIX_SOURCE)
4620 /* BSD has one and only one pattern buffer. */
4621 static struct re_pattern_buffer re_comp_buf;
4631 if (!re_comp_buf.buffer)
4632 return "No previous regular expression";
4636 if (!re_comp_buf.buffer)
4638 re_comp_buf.buffer = (unsigned char *) malloc (200);
4639 if (re_comp_buf.buffer == NULL)
4640 return "Memory exhausted";
4641 re_comp_buf.allocated = 200;
4643 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
4644 if (re_comp_buf.fastmap == NULL)
4645 return "Memory exhausted";
4648 /* Since `re_exec' always passes NULL for the `regs' argument, we
4649 don't need to initialize the pattern buffer fields which affect it. */
4651 /* Match anchors at newlines. */
4652 re_comp_buf.newline_anchor = 1;
4654 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
4656 /* Yes, we're discarding `const' here. */
4657 return (char *) re_error_msg[(int) ret];
4665 const int len = strlen (s);
4667 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
4669 #endif /* not emacs and not _POSIX_SOURCE */
4671 /* POSIX.2 functions. Don't define these for Emacs. */
4675 /* regcomp takes a regular expression as a string and compiles it.
4677 PREG is a regex_t *. We do not expect any fields to be initialized,
4678 since POSIX says we shouldn't. Thus, we set
4680 `buffer' to the compiled pattern;
4681 `used' to the length of the compiled pattern;
4682 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
4683 REG_EXTENDED bit in CFLAGS is set; otherwise, to
4684 RE_SYNTAX_POSIX_BASIC;
4685 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
4686 `fastmap' and `fastmap_accurate' to zero;
4687 `re_nsub' to the number of subexpressions in PATTERN.
4689 PATTERN is the address of the pattern string.
4691 CFLAGS is a series of bits which affect compilation.
4693 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
4694 use POSIX basic syntax.
4696 If REG_NEWLINE is set, then . and [^...] don't match newline.
4697 Also, regexec will try a match beginning after every newline.
4699 If REG_ICASE is set, then we considers upper- and lowercase
4700 versions of letters to be equivalent when matching.
4702 If REG_NOSUB is set, then when PREG is passed to regexec, that
4703 routine will report only success or failure, and nothing about the
4706 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
4707 the return codes and their meanings.) */
4710 regcomp (preg, pattern, cflags)
4712 const char *pattern;
4717 = cflags & REG_EXTENDED ? RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
4719 /* regex_compile will allocate the space for the compiled pattern. */
4722 /* Don't bother to use a fastmap when searching. This simplifies the
4723 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
4724 characters after newlines into the fastmap. This way, we just try
4728 if (cflags & REG_ICASE)
4732 preg->translate = (char *) malloc (CHAR_SET_SIZE);
4733 if (preg->translate == NULL)
4734 return (int) REG_ESPACE;
4736 /* Map uppercase characters to corresponding lowercase ones. */
4737 for (i = 0; i < CHAR_SET_SIZE; i++)
4738 preg->translate[i] = isupper (i) ? tolower (i) : i;
4741 preg->translate = NULL;
4743 /* If REG_NEWLINE is set, newlines are treated differently. */
4744 if (cflags & REG_NEWLINE)
4745 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
4746 syntax &= ~RE_DOT_NEWLINE;
4747 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
4748 /* It also changes the matching behavior. */
4749 preg->newline_anchor = 1;
4752 preg->newline_anchor = 0;
4754 preg->no_sub = !!(cflags & REG_NOSUB);
4756 /* POSIX says a null character in the pattern terminates it, so we
4757 can use strlen here in compiling the pattern. */
4758 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
4760 /* POSIX doesn't distinguish between an unmatched open-group and an
4761 unmatched close-group: both are REG_EPAREN. */
4762 if (ret == REG_ERPAREN) ret = REG_EPAREN;
4768 /* regexec searches for a given pattern, specified by PREG, in the
4771 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
4772 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
4773 least NMATCH elements, and we set them to the offsets of the
4774 corresponding matched substrings.
4776 EFLAGS specifies `execution flags' which affect matching: if
4777 REG_NOTBOL is set, then ^ does not match at the beginning of the
4778 string; if REG_NOTEOL is set, then $ does not match at the end.
4780 We return 0 if we find a match and REG_NOMATCH if not. */
4783 regexec (preg, string, nmatch, pmatch, eflags)
4784 const regex_t *preg;
4787 regmatch_t pmatch[];
4791 struct re_registers regs;
4792 regex_t private_preg;
4793 int len = strlen (string);
4794 boolean want_reg_info = !preg->no_sub && nmatch > 0;
4796 private_preg = *preg;
4798 private_preg.not_bol = !!(eflags & REG_NOTBOL);
4799 private_preg.not_eol = !!(eflags & REG_NOTEOL);
4801 /* The user has told us exactly how many registers to return
4802 information about, via `nmatch'. We have to pass that on to the
4803 matching routines. */
4804 private_preg.regs_allocated = REGS_FIXED;
4808 regs.num_regs = nmatch;
4809 regs.start = TALLOC (nmatch, regoff_t);
4810 regs.end = TALLOC (nmatch, regoff_t);
4811 if (regs.start == NULL || regs.end == NULL)
4812 return (int) REG_NOMATCH;
4815 /* Perform the searching operation. */
4816 ret = re_search (&private_preg, string, len,
4817 /* start: */ 0, /* range: */ len,
4818 want_reg_info ? ®s : (struct re_registers *) 0);
4820 /* Copy the register information to the POSIX structure. */
4827 for (r = 0; r < nmatch; r++)
4829 pmatch[r].rm_so = regs.start[r];
4830 pmatch[r].rm_eo = regs.end[r];
4834 /* If we needed the temporary register info, free the space now. */
4839 /* We want zero return to mean success, unlike `re_search'. */
4840 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
4844 /* Returns a message corresponding to an error code, ERRCODE, returned
4845 from either regcomp or regexec. We don't use PREG here. */
4848 regerror (errcode, preg, errbuf, errbuf_size)
4850 const regex_t *preg;
4855 = re_error_msg[errcode] == NULL ? "Success" : re_error_msg[errcode];
4856 size_t msg_size = strlen (msg) + 1; /* Includes the null. */
4858 if (errbuf_size != 0)
4860 if (msg_size > errbuf_size)
4862 strncpy (errbuf, msg, errbuf_size - 1);
4863 errbuf[errbuf_size - 1] = 0;
4866 strcpy (errbuf, msg);
4873 /* Free dynamically allocated space used by PREG. */
4879 if (preg->buffer != NULL)
4880 free (preg->buffer);
4881 preg->buffer = NULL;
4883 preg->allocated = 0;
4886 if (preg->fastmap != NULL)
4887 free (preg->fastmap);
4888 preg->fastmap = NULL;
4889 preg->fastmap_accurate = 0;
4891 if (preg->translate != NULL)
4892 free (preg->translate);
4893 preg->translate = NULL;
4896 #endif /* not emacs */
4900 make-backup-files: t
4902 trim-versions-without-asking: nil