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 USG || STDC_HEADERS
50 #define bcmp(s1, s2, n) memcmp ((s1), (s2), (n))
51 #define bcopy(s, d, n) memcpy ((d), (s), (n))
52 #define bzero(s, n) memset ((s), 0, (n))
65 /* Define the syntax stuff for \<, \>, etc. */
67 /* This must be nonzero for the wordchar and notwordchar pattern
68 commands in re_match_2. */
75 extern char *re_syntax_table;
77 #else /* not SYNTAX_TABLE */
79 /* How many characters in the character set. */
80 #define CHAR_SET_SIZE 256
82 static char re_syntax_table[CHAR_SET_SIZE];
93 bzero (re_syntax_table, sizeof re_syntax_table);
95 for (c = 'a'; c <= 'z'; c++)
96 re_syntax_table[c] = Sword;
98 for (c = 'A'; c <= 'Z'; c++)
99 re_syntax_table[c] = Sword;
101 for (c = '0'; c <= '9'; c++)
102 re_syntax_table[c] = Sword;
104 re_syntax_table['_'] = Sword;
109 #endif /* not SYNTAX_TABLE */
111 #define SYNTAX(c) re_syntax_table[c]
113 #endif /* not emacs */
115 /* Get the interface, including the syntax bits. */
119 /* isalpha etc. are used for the character classes. */
122 #define isgraph(c) (isprint (c) && !isspace (c))
125 #define isblank(c) ((c) == ' ' || (c) == '\t')
132 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
133 since ours (we hope) works properly with all combinations of
134 machines, compilers, `char' and `unsigned char' argument types.
135 (Per Bothner suggested the basic approach.) */
136 #undef SIGN_EXTEND_CHAR
138 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
140 /* As in Harbison and Steele. */
141 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
144 /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we
145 use `alloca' instead of `malloc'. This is because using malloc in
146 re_search* or re_match* could cause memory leaks when C-g is used in
147 Emacs; also, malloc is slower and causes storage fragmentation. On
148 the other hand, malloc is more portable, and easier to debug.
150 Because we sometimes use alloca, some routines have to be macros,
151 not functions -- `alloca'-allocated space disappears at the end of the
152 function it is called in. */
156 #define REGEX_ALLOCATE malloc
157 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
159 #else /* not REGEX_MALLOC */
161 /* Emacs already defines alloca, sometimes. */
164 /* Make alloca work the best possible way. */
166 #define alloca __builtin_alloca
167 #else /* not __GNUC__ */
170 #else /* not __GNUC__ or HAVE_ALLOCA_H */
171 #ifndef _AIX /* Already did AIX, up at the top. */
173 #endif /* not _AIX */
174 #endif /* not HAVE_ALLOCA_H */
175 #endif /* not __GNUC__ */
177 #endif /* not alloca */
179 #define REGEX_ALLOCATE alloca
181 /* Assumes a `char *destination' variable. */
182 #define REGEX_REALLOCATE(source, osize, nsize) \
183 (destination = (char *) alloca (nsize), \
184 bcopy (source, destination, osize), \
187 #endif /* not REGEX_MALLOC */
190 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
191 `string1' or just past its end. This works if PTR is NULL, which is
193 #define FIRST_STRING_P(ptr) \
194 (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
196 /* (Re)Allocate N items of type T using malloc, or fail. */
197 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
198 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
199 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
201 #define BYTEWIDTH 8 /* In bits. */
203 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
205 #define MAX(a, b) ((a) > (b) ? (a) : (b))
206 #define MIN(a, b) ((a) < (b) ? (a) : (b))
208 typedef char boolean;
212 /* These are the command codes that appear in compiled regular
213 expressions. Some opcodes are followed by argument bytes. A
214 command code can specify any interpretation whatsoever for its
215 arguments. Zero bytes may appear in the compiled regular expression.
217 The value of `exactn' is needed in search.c (search_buffer) in Emacs.
218 So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of
219 `exactn' we use here must also be 1. */
225 /* Followed by one byte giving n, then by n literal bytes. */
228 /* Matches any (more or less) character. */
231 /* Matches any one char belonging to specified set. First
232 following byte is number of bitmap bytes. Then come bytes
233 for a bitmap saying which chars are in. Bits in each byte
234 are ordered low-bit-first. A character is in the set if its
235 bit is 1. A character too large to have a bit in the map is
236 automatically not in the set. */
239 /* Same parameters as charset, but match any character that is
240 not one of those specified. */
243 /* Start remembering the text that is matched, for storing in a
244 register. Followed by one byte with the register number, in
245 the range 0 to one less than the pattern buffer's re_nsub
246 field. Then followed by one byte with the number of groups
247 inner to this one. (This last has to be part of the
248 start_memory only because we need it in the on_failure_jump
252 /* Stop remembering the text that is matched and store it in a
253 memory register. Followed by one byte with the register
254 number, in the range 0 to one less than `re_nsub' in the
255 pattern buffer, and one byte with the number of inner groups,
256 just like `start_memory'. (We need the number of inner
257 groups here because we don't have any easy way of finding the
258 corresponding start_memory when we're at a stop_memory.) */
261 /* Match a duplicate of something remembered. Followed by one
262 byte containing the register number. */
265 /* Fail unless at beginning of line. */
268 /* Fail unless at end of line. */
271 /* Succeeds if at beginning of buffer (if emacs) or at beginning
272 of string to be matched (if not). */
275 /* Analogously, for end of buffer/string. */
278 /* Followed by two byte relative address to which to jump. */
281 /* Same as jump, but marks the end of an alternative. */
284 /* Followed by two-byte relative address of place to resume at
285 in case of failure. */
288 /* Like on_failure_jump, but pushes a placeholder instead of the
289 current string position when executed. */
290 on_failure_keep_string_jump,
292 /* Throw away latest failure point and then jump to following
293 two-byte relative address. */
296 /* Change to pop_failure_jump if know won't have to backtrack to
297 match; otherwise change to jump. This is used to jump
298 back to the beginning of a repeat. If what follows this jump
299 clearly won't match what the repeat does, such that we can be
300 sure that there is no use backtracking out of repetitions
301 already matched, then we change it to a pop_failure_jump.
302 Followed by two-byte address. */
305 /* Jump to following two-byte address, and push a dummy failure
306 point. This failure point will be thrown away if an attempt
307 is made to use it for a failure. A `+' construct makes this
308 before the first repeat. Also used as an intermediary kind
309 of jump when compiling an alternative. */
312 /* Push a dummy failure point and continue. Used at the end of
316 /* Followed by two-byte relative address and two-byte number n.
317 After matching N times, jump to the address upon failure. */
320 /* Followed by two-byte relative address, and two-byte number n.
321 Jump to the address N times, then fail. */
324 /* Set the following two-byte relative address to the
325 subsequent two-byte number. The address *includes* the two
329 wordchar, /* Matches any word-constituent character. */
330 notwordchar, /* Matches any char that is not a word-constituent. */
332 wordbeg, /* Succeeds if at word beginning. */
333 wordend, /* Succeeds if at word end. */
335 wordbound, /* Succeeds if at a word boundary. */
336 notwordbound /* Succeeds if not at a word boundary. */
339 ,before_dot, /* Succeeds if before point. */
340 at_dot, /* Succeeds if at point. */
341 after_dot, /* Succeeds if after point. */
343 /* Matches any character whose syntax is specified. Followed by
344 a byte which contains a syntax code, e.g., Sword. */
347 /* Matches any character whose syntax is not that specified. */
352 /* Common operations on the compiled pattern. */
354 /* Store NUMBER in two contiguous bytes starting at DESTINATION. */
356 #define STORE_NUMBER(destination, number) \
358 (destination)[0] = (number) & 0377; \
359 (destination)[1] = (number) >> 8; \
362 /* Same as STORE_NUMBER, except increment DESTINATION to
363 the byte after where the number is stored. Therefore, DESTINATION
364 must be an lvalue. */
366 #define STORE_NUMBER_AND_INCR(destination, number) \
368 STORE_NUMBER (destination, number); \
369 (destination) += 2; \
372 /* Put into DESTINATION a number stored in two contiguous bytes starting
375 #define EXTRACT_NUMBER(destination, source) \
377 (destination) = *(source) & 0377; \
378 (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \
383 extract_number (dest, source)
385 unsigned char *source;
387 int temp = SIGN_EXTEND_CHAR (*(source + 1));
388 *dest = *source & 0377;
392 #ifndef EXTRACT_MACROS /* To debug the macros. */
393 #undef EXTRACT_NUMBER
394 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
395 #endif /* not EXTRACT_MACROS */
399 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
400 SOURCE must be an lvalue. */
402 #define EXTRACT_NUMBER_AND_INCR(destination, source) \
404 EXTRACT_NUMBER (destination, source); \
410 extract_number_and_incr (destination, source)
412 unsigned char **source;
414 extract_number (destination, *source);
418 #ifndef EXTRACT_MACROS
419 #undef EXTRACT_NUMBER_AND_INCR
420 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
421 extract_number_and_incr (&dest, &src)
422 #endif /* not EXTRACT_MACROS */
426 /* If DEBUG is defined, Regex prints many voluminous messages about what
427 it is doing (if the variable `debug' is nonzero). If linked with the
428 main program in `iregex.c', you can enter patterns and strings
429 interactively. And if linked with the main program in `main.c' and
430 the other test files, you can run the already-written tests. */
434 /* We use standard I/O for debugging. */
437 /* It is useful to test things that ``must'' be true when debugging. */
440 static int debug = 0;
442 #define DEBUG_STATEMENT(e) e
443 #define DEBUG_PRINT1(x) if (debug) printf (x)
444 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
445 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
446 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \
447 if (debug) print_partial_compiled_pattern (s, e)
448 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \
449 if (debug) print_double_string (w, s1, sz1, s2, sz2)
452 extern void printchar ();
454 /* Print the fastmap in human-readable form. */
457 print_fastmap (fastmap)
460 unsigned was_a_range = 0;
463 while (i < (1 << BYTEWIDTH))
469 while (i < (1 << BYTEWIDTH) && fastmap[i])
485 /* Print a compiled pattern string in human-readable form, starting at
486 the START pointer into it and ending just before the pointer END. */
489 print_partial_compiled_pattern (start, end)
490 unsigned char *start;
494 unsigned char *p = start;
495 unsigned char *pend = end;
503 /* Loop over pattern commands. */
506 switch ((re_opcode_t) *p++)
514 printf ("/exactn/%d", mcnt);
525 printf ("/start_memory/%d/%d", mcnt, *p++);
530 printf ("/stop_memory/%d/%d", mcnt, *p++);
534 printf ("/duplicate/%d", *p++);
546 printf ("/charset%s",
547 (re_opcode_t) *(p - 1) == charset_not ? "_not" : "");
549 assert (p + *p < pend);
551 for (c = 0; c < *p; c++)
554 unsigned char map_byte = p[1 + c];
558 for (bit = 0; bit < BYTEWIDTH; bit++)
559 if (map_byte & (1 << bit))
560 printchar (c * BYTEWIDTH + bit);
574 case on_failure_jump:
575 extract_number_and_incr (&mcnt, &p);
576 printf ("/on_failure_jump/0/%d", mcnt);
579 case on_failure_keep_string_jump:
580 extract_number_and_incr (&mcnt, &p);
581 printf ("/on_failure_keep_string_jump/0/%d", mcnt);
584 case dummy_failure_jump:
585 extract_number_and_incr (&mcnt, &p);
586 printf ("/dummy_failure_jump/0/%d", mcnt);
589 case push_dummy_failure:
590 printf ("/push_dummy_failure");
594 extract_number_and_incr (&mcnt, &p);
595 printf ("/maybe_pop_jump/0/%d", mcnt);
598 case pop_failure_jump:
599 extract_number_and_incr (&mcnt, &p);
600 printf ("/pop_failure_jump/0/%d", mcnt);
604 extract_number_and_incr (&mcnt, &p);
605 printf ("/jump_past_alt/0/%d", mcnt);
609 extract_number_and_incr (&mcnt, &p);
610 printf ("/jump/0/%d", mcnt);
614 extract_number_and_incr (&mcnt, &p);
615 extract_number_and_incr (&mcnt2, &p);
616 printf ("/succeed_n/0/%d/0/%d", mcnt, mcnt2);
620 extract_number_and_incr (&mcnt, &p);
621 extract_number_and_incr (&mcnt2, &p);
622 printf ("/jump_n/0/%d/0/%d", mcnt, mcnt2);
626 extract_number_and_incr (&mcnt, &p);
627 extract_number_and_incr (&mcnt2, &p);
628 printf ("/set_number_at/0/%d/0/%d", mcnt, mcnt2);
632 printf ("/wordbound");
636 printf ("/notwordbound");
648 printf ("/before_dot");
656 printf ("/after_dot");
660 printf ("/syntaxspec");
662 printf ("/%d", mcnt);
666 printf ("/notsyntaxspec");
668 printf ("/%d", mcnt);
673 printf ("/wordchar");
677 printf ("/notwordchar");
689 printf ("?%d", *(p-1));
697 print_compiled_pattern (bufp)
698 struct re_pattern_buffer *bufp;
700 unsigned char *buffer = bufp->buffer;
702 print_partial_compiled_pattern (buffer, buffer + bufp->used);
703 printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated);
705 if (bufp->fastmap_accurate && bufp->fastmap)
707 printf ("fastmap: ");
708 print_fastmap (bufp->fastmap);
711 printf ("re_nsub: %d\t", bufp->re_nsub);
712 printf ("regs_alloc: %d\t", bufp->regs_allocated);
713 printf ("can_be_null: %d\t", bufp->can_be_null);
714 printf ("newline_anchor: %d\n", bufp->newline_anchor);
715 printf ("no_sub: %d\t", bufp->no_sub);
716 printf ("not_bol: %d\t", bufp->not_bol);
717 printf ("not_eol: %d\t", bufp->not_eol);
718 printf ("syntax: %d\n", bufp->syntax);
719 /* Perhaps we should print the translate table? */
724 print_double_string (where, string1, size1, string2, size2)
737 if (FIRST_STRING_P (where))
739 for (this_char = where - string1; this_char < size1; this_char++)
740 printchar (string1[this_char]);
745 for (this_char = where - string2; this_char < size2; this_char++)
746 printchar (string2[this_char]);
750 #else /* not DEBUG */
755 #define DEBUG_STATEMENT(e)
756 #define DEBUG_PRINT1(x)
757 #define DEBUG_PRINT2(x1, x2)
758 #define DEBUG_PRINT3(x1, x2, x3)
759 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
760 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
762 #endif /* not DEBUG */
764 /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can
765 also be assigned to arbitrarily: each pattern buffer stores its own
766 syntax, so it can be changed between regex compilations. */
767 reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS;
770 /* Specify the precise syntax of regexps for compilation. This provides
771 for compatibility for various utilities which historically have
772 different, incompatible syntaxes.
774 The argument SYNTAX is a bit mask comprised of the various bits
775 defined in regex.h. We return the old syntax. */
778 re_set_syntax (syntax)
781 reg_syntax_t ret = re_syntax_options;
783 re_syntax_options = syntax;
787 /* This table gives an error message for each of the error codes listed
788 in regex.h. Obviously the order here has to be same as there. */
790 static const char *re_error_msg[] =
791 { NULL, /* REG_NOERROR */
792 "No match", /* REG_NOMATCH */
793 "Invalid regular expression", /* REG_BADPAT */
794 "Invalid collation character", /* REG_ECOLLATE */
795 "Invalid character class name", /* REG_ECTYPE */
796 "Trailing backslash", /* REG_EESCAPE */
797 "Invalid back reference", /* REG_ESUBREG */
798 "Unmatched [ or [^", /* REG_EBRACK */
799 "Unmatched ( or \\(", /* REG_EPAREN */
800 "Unmatched \\{", /* REG_EBRACE */
801 "Invalid content of \\{\\}", /* REG_BADBR */
802 "Invalid range end", /* REG_ERANGE */
803 "Memory exhausted", /* REG_ESPACE */
804 "Invalid preceding regular expression", /* REG_BADRPT */
805 "Premature end of regular expression", /* REG_EEND */
806 "Regular expression too big", /* REG_ESIZE */
807 "Unmatched ) or \\)", /* REG_ERPAREN */
810 /* Subroutine declarations and macros for regex_compile. */
812 static void store_op1 (), store_op2 ();
813 static void insert_op1 (), insert_op2 ();
814 static boolean at_begline_loc_p (), at_endline_loc_p ();
815 static boolean group_in_compile_stack ();
816 static reg_errcode_t compile_range ();
818 /* Fetch the next character in the uncompiled pattern---translating it
819 if necessary. Also cast from a signed character in the constant
820 string passed to us by the user to an unsigned char that we can use
821 as an array index (in, e.g., `translate'). */
822 #define PATFETCH(c) \
823 do {if (p == pend) return REG_EEND; \
824 c = (unsigned char) *p++; \
825 if (translate) c = translate[c]; \
828 /* Fetch the next character in the uncompiled pattern, with no
830 #define PATFETCH_RAW(c) \
831 do {if (p == pend) return REG_EEND; \
832 c = (unsigned char) *p++; \
835 /* Go backwards one character in the pattern. */
836 #define PATUNFETCH p--
839 /* If `translate' is non-null, return translate[D], else just D. We
840 cast the subscript to translate because some data is declared as
841 `char *', to avoid warnings when a string constant is passed. But
842 when we use a character as a subscript we must make it unsigned. */
843 #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d))
846 /* Macros for outputting the compiled pattern into `buffer'. */
848 /* If the buffer isn't allocated when it comes in, use this. */
849 #define INIT_BUF_SIZE 32
851 /* Make sure we have at least N more bytes of space in buffer. */
852 #define GET_BUFFER_SPACE(n) \
853 while (b - bufp->buffer + (n) > bufp->allocated) \
856 /* Make sure we have one more byte of buffer space and then add C to it. */
857 #define BUF_PUSH(c) \
859 GET_BUFFER_SPACE (1); \
860 *b++ = (unsigned char) (c); \
864 /* Ensure we have two more bytes of buffer space and then append C1 and C2. */
865 #define BUF_PUSH_2(c1, c2) \
867 GET_BUFFER_SPACE (2); \
868 *b++ = (unsigned char) (c1); \
869 *b++ = (unsigned char) (c2); \
873 /* As with BUF_PUSH_2, except for three bytes. */
874 #define BUF_PUSH_3(c1, c2, c3) \
876 GET_BUFFER_SPACE (3); \
877 *b++ = (unsigned char) (c1); \
878 *b++ = (unsigned char) (c2); \
879 *b++ = (unsigned char) (c3); \
883 /* Store a jump with opcode OP at LOC to location TO. We store a
884 relative address offset by the three bytes the jump itself occupies. */
885 #define STORE_JUMP(op, loc, to) \
886 store_op1 (op, loc, (to) - (loc) - 3)
888 /* Likewise, for a two-argument jump. */
889 #define STORE_JUMP2(op, loc, to, arg) \
890 store_op2 (op, loc, (to) - (loc) - 3, arg)
892 /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */
893 #define INSERT_JUMP(op, loc, to) \
894 insert_op1 (op, loc, (to) - (loc) - 3, b)
896 /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */
897 #define INSERT_JUMP2(op, loc, to, arg) \
898 insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
901 /* This is not an arbitrary limit: the arguments which represent offsets
902 into the pattern are two bytes long. So if 2^16 bytes turns out to
903 be too small, many things would have to change. */
904 #define MAX_BUF_SIZE (1L << 16)
907 /* Extend the buffer by twice its current size via realloc and
908 reset the pointers that pointed into the old block to point to the
909 correct places in the new one. If extending the buffer results in it
910 being larger than MAX_BUF_SIZE, then flag memory exhausted. */
911 #define EXTEND_BUFFER() \
913 unsigned char *old_buffer = bufp->buffer; \
914 if (bufp->allocated == MAX_BUF_SIZE) \
916 bufp->allocated <<= 1; \
917 if (bufp->allocated > MAX_BUF_SIZE) \
918 bufp->allocated = MAX_BUF_SIZE; \
919 bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\
920 if (bufp->buffer == NULL) \
922 /* If the buffer moved, move all the pointers into it. */ \
923 if (old_buffer != bufp->buffer) \
925 b = (b - old_buffer) + bufp->buffer; \
926 begalt = (begalt - old_buffer) + bufp->buffer; \
927 if (fixup_alt_jump) \
928 fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
930 laststart = (laststart - old_buffer) + bufp->buffer; \
932 pending_exact = (pending_exact - old_buffer) + bufp->buffer; \
937 /* Since we have one byte reserved for the register number argument to
938 {start,stop}_memory, the maximum number of groups we can report
939 things about is what fits in that byte. */
940 #define MAX_REGNUM 255
942 /* But patterns can have more than `MAX_REGNUM' registers. We just
943 ignore the excess. */
944 typedef unsigned regnum_t;
947 /* Macros for the compile stack. */
949 /* Since offsets can go either forwards or backwards, this type needs to
950 be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */
951 typedef int pattern_offset_t;
955 pattern_offset_t begalt_offset;
956 pattern_offset_t fixup_alt_jump;
957 pattern_offset_t inner_group_offset;
958 pattern_offset_t laststart_offset;
960 } compile_stack_elt_t;
965 compile_stack_elt_t *stack;
967 unsigned avail; /* Offset of next open position. */
968 } compile_stack_type;
971 #define INIT_COMPILE_STACK_SIZE 32
973 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0)
974 #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size)
976 /* The next available element. */
977 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
980 /* Set the bit for character C in a list. */
981 #define SET_LIST_BIT(c) \
982 (b[((unsigned char) (c)) / BYTEWIDTH] \
983 |= 1 << (((unsigned char) c) % BYTEWIDTH))
986 /* Get the next unsigned number in the uncompiled pattern. */
987 #define GET_UNSIGNED_NUMBER(num) \
991 while (isdigit (c)) \
995 num = num * 10 + c - '0'; \
1003 #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */
1005 #define IS_CHAR_CLASS(string) \
1006 (STREQ (string, "alpha") || STREQ (string, "upper") \
1007 || STREQ (string, "lower") || STREQ (string, "digit") \
1008 || STREQ (string, "alnum") || STREQ (string, "xdigit") \
1009 || STREQ (string, "space") || STREQ (string, "print") \
1010 || STREQ (string, "punct") || STREQ (string, "graph") \
1011 || STREQ (string, "cntrl") || STREQ (string, "blank"))
1013 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
1014 Returns one of error codes defined in `regex.h', or zero for success.
1016 Assumes the `allocated' (and perhaps `buffer') and `translate'
1017 fields are set in BUFP on entry.
1019 If it succeeds, results are put in BUFP (if it returns an error, the
1020 contents of BUFP are undefined):
1021 `buffer' is the compiled pattern;
1022 `syntax' is set to SYNTAX;
1023 `used' is set to the length of the compiled pattern;
1024 `fastmap_accurate' is set to zero;
1025 `re_nsub' is set to the number of groups in PATTERN;
1026 `not_bol' and `not_eol' are set to zero.
1028 The `fastmap' and `newline_anchor' fields are neither
1029 examined nor set. */
1031 static reg_errcode_t
1032 regex_compile (pattern, size, syntax, bufp)
1033 const char *pattern;
1035 reg_syntax_t syntax;
1036 struct re_pattern_buffer *bufp;
1038 /* We fetch characters from PATTERN here. Even though PATTERN is
1039 `char *' (i.e., signed), we declare these variables as unsigned, so
1040 they can be reliably used as array indices. */
1041 register unsigned char c, c1;
1043 /* A random tempory spot in PATTERN. */
1046 /* Points to the end of the buffer, where we should append. */
1047 register unsigned char *b;
1049 /* Keeps track of unclosed groups. */
1050 compile_stack_type compile_stack;
1052 /* Points to the current (ending) position in the pattern. */
1053 const char *p = pattern;
1054 const char *pend = pattern + size;
1056 /* How to translate the characters in the pattern. */
1057 char *translate = bufp->translate;
1059 /* Address of the count-byte of the most recently inserted `exactn'
1060 command. This makes it possible to tell if a new exact-match
1061 character can be added to that command or if the character requires
1062 a new `exactn' command. */
1063 unsigned char *pending_exact = 0;
1065 /* Address of start of the most recently finished expression.
1066 This tells, e.g., postfix * where to find the start of its
1067 operand. Reset at the beginning of groups and alternatives. */
1068 unsigned char *laststart = 0;
1070 /* Address of beginning of regexp, or inside of last group. */
1071 unsigned char *begalt;
1073 /* Place in the uncompiled pattern (i.e., the {) to
1074 which to go back if the interval is invalid. */
1075 const char *beg_interval;
1077 /* Address of the place where a forward jump should go to the end of
1078 the containing expression. Each alternative of an `or' -- except the
1079 last -- ends with a forward jump of this sort. */
1080 unsigned char *fixup_alt_jump = 0;
1082 /* Counts open-groups as they are encountered. Remembered for the
1083 matching close-group on the compile stack, so the same register
1084 number is put in the stop_memory as the start_memory. */
1085 regnum_t regnum = 0;
1088 DEBUG_PRINT1 ("\nCompiling pattern: ");
1091 unsigned debug_count;
1093 for (debug_count = 0; debug_count < size; debug_count++)
1094 printchar (pattern[debug_count]);
1099 /* Initialize the compile stack. */
1100 compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
1101 if (compile_stack.stack == NULL)
1104 compile_stack.size = INIT_COMPILE_STACK_SIZE;
1105 compile_stack.avail = 0;
1107 /* Initialize the pattern buffer. */
1108 bufp->syntax = syntax;
1109 bufp->fastmap_accurate = 0;
1110 bufp->not_bol = bufp->not_eol = 0;
1112 /* Set `used' to zero, so that if we return an error, the pattern
1113 printer (for debugging) will think there's no pattern. We reset it
1117 /* Always count groups, whether or not bufp->no_sub is set. */
1120 #if !defined (emacs) && !defined (SYNTAX_TABLE)
1121 /* Initialize the syntax table. */
1122 init_syntax_once ();
1125 if (bufp->allocated == 0)
1128 { /* If zero allocated, but buffer is non-null, try to realloc
1129 enough space. This loses if buffer's address is bogus, but
1130 that is the user's responsibility. */
1131 RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
1134 { /* Caller did not allocate a buffer. Do it for them. */
1135 bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
1137 if (!bufp->buffer) return REG_ESPACE;
1139 bufp->allocated = INIT_BUF_SIZE;
1142 begalt = b = bufp->buffer;
1144 /* Loop through the uncompiled pattern until we're at the end. */
1153 if ( /* If at start of pattern, it's an operator. */
1155 /* If context independent, it's an operator. */
1156 || syntax & RE_CONTEXT_INDEP_ANCHORS
1157 /* Otherwise, depends on what's come before. */
1158 || at_begline_loc_p (pattern, p, syntax))
1168 if ( /* If at end of pattern, it's an operator. */
1170 /* If context independent, it's an operator. */
1171 || syntax & RE_CONTEXT_INDEP_ANCHORS
1172 /* Otherwise, depends on what's next. */
1173 || at_endline_loc_p (p, pend, syntax))
1183 if ((syntax & RE_BK_PLUS_QM)
1184 || (syntax & RE_LIMITED_OPS))
1188 /* If there is no previous pattern... */
1191 if (syntax & RE_CONTEXT_INVALID_OPS)
1193 else if (!(syntax & RE_CONTEXT_INDEP_OPS))
1198 /* Are we optimizing this jump? */
1199 boolean keep_string_p = false;
1201 /* 1 means zero (many) matches is allowed. */
1202 char zero_times_ok = 0, many_times_ok = 0;
1204 /* If there is a sequence of repetition chars, collapse it
1205 down to just one (the right one). We can't combine
1206 interval operators with these because of, e.g., `a{2}*',
1207 which should only match an even number of `a's. */
1211 zero_times_ok |= c != '+';
1212 many_times_ok |= c != '?';
1220 || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
1223 else if (syntax & RE_BK_PLUS_QM && c == '\\')
1225 if (p == pend) return REG_EESCAPE;
1228 if (!(c1 == '+' || c1 == '?'))
1243 /* If we get here, we found another repeat character. */
1246 /* Star, etc. applied to an empty pattern is equivalent
1247 to an empty pattern. */
1251 /* Now we know whether or not zero matches is allowed
1252 and also whether or not two or more matches is allowed. */
1254 { /* More than one repetition is allowed, so put in at the
1255 end a backward relative jump from `b' to before the next
1256 jump we're going to put in below (which jumps from
1257 laststart to after this jump).
1259 But if we are at the `*' in the exact sequence `.*\n',
1260 insert an unconditional jump backwards to the .,
1261 instead of the beginning of the loop. This way we only
1262 push a failure point once, instead of every time
1263 through the loop. */
1264 assert (p - 1 > pattern);
1266 /* Allocate the space for the jump. */
1267 GET_BUFFER_SPACE (3);
1269 /* We know we are not at the first character of the pattern,
1270 because laststart was nonzero. And we've already
1271 incremented `p', by the way, to be the character after
1272 the `*'. Do we have to do something analogous here
1273 for null bytes, because of RE_DOT_NOT_NULL? */
1274 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
1275 && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
1276 && !(syntax & RE_DOT_NEWLINE))
1277 { /* We have .*\n. */
1278 STORE_JUMP (jump, b, laststart);
1279 keep_string_p = true;
1282 /* Anything else. */
1283 STORE_JUMP (maybe_pop_jump, b, laststart - 3);
1285 /* We've added more stuff to the buffer. */
1289 /* On failure, jump from laststart to b + 3, which will be the
1290 end of the buffer after this jump is inserted. */
1291 GET_BUFFER_SPACE (3);
1292 INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
1300 /* At least one repetition is required, so insert a
1301 `dummy_failure_jump' before the initial
1302 `on_failure_jump' instruction of the loop. This
1303 effects a skip over that instruction the first time
1304 we hit that loop. */
1305 GET_BUFFER_SPACE (3);
1306 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
1321 boolean had_char_class = false;
1323 if (p == pend) return REG_EBRACK;
1325 /* Ensure that we have enough space to push a charset: the
1326 opcode, the length count, and the bitset; 34 bytes in all. */
1327 GET_BUFFER_SPACE (34);
1331 /* We test `*p == '^' twice, instead of using an if
1332 statement, so we only need one BUF_PUSH. */
1333 BUF_PUSH (*p == '^' ? charset_not : charset);
1337 /* Remember the first position in the bracket expression. */
1340 /* Push the number of bytes in the bitmap. */
1341 BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
1343 /* Clear the whole map. */
1344 bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
1346 /* charset_not matches newline according to a syntax bit. */
1347 if ((re_opcode_t) b[-2] == charset_not
1348 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
1349 SET_LIST_BIT ('\n');
1351 /* Read in characters and ranges, setting map bits. */
1354 if (p == pend) return REG_EBRACK;
1358 /* \ might escape characters inside [...] and [^...]. */
1359 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
1361 if (p == pend) return REG_EESCAPE;
1368 /* Could be the end of the bracket expression. If it's
1369 not (i.e., when the bracket expression is `[]' so
1370 far), the ']' character bit gets set way below. */
1371 if (c == ']' && p != p1 + 1)
1374 /* Look ahead to see if it's a range when the last thing
1375 was a character class. */
1376 if (had_char_class && c == '-' && *p != ']')
1379 /* Look ahead to see if it's a range when the last thing
1380 was a character: if this is a hyphen not at the
1381 beginning or the end of a list, then it's the range
1384 && !(p - 2 >= pattern && p[-2] == '[')
1385 && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
1389 = compile_range (&p, pend, translate, syntax, b);
1390 if (ret != REG_NOERROR) return ret;
1393 else if (p[0] == '-' && p[1] != ']')
1394 { /* This handles ranges made up of characters only. */
1397 /* Move past the `-'. */
1400 ret = compile_range (&p, pend, translate, syntax, b);
1401 if (ret != REG_NOERROR) return ret;
1404 /* See if we're at the beginning of a possible character
1407 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
1408 { /* Leave room for the null. */
1409 char str[CHAR_CLASS_MAX_LENGTH + 1];
1414 /* If pattern is `[[:'. */
1415 if (p == pend) return REG_EBRACK;
1420 if (c == ':' || c == ']' || p == pend
1421 || c1 == CHAR_CLASS_MAX_LENGTH)
1427 /* If isn't a word bracketed by `[:' and:`]':
1428 undo the ending character, the letters, and leave
1429 the leading `:' and `[' (but set bits for them). */
1430 if (c == ':' && *p == ']')
1433 boolean is_alnum = STREQ (str, "alnum");
1434 boolean is_alpha = STREQ (str, "alpha");
1435 boolean is_blank = STREQ (str, "blank");
1436 boolean is_cntrl = STREQ (str, "cntrl");
1437 boolean is_digit = STREQ (str, "digit");
1438 boolean is_graph = STREQ (str, "graph");
1439 boolean is_lower = STREQ (str, "lower");
1440 boolean is_print = STREQ (str, "print");
1441 boolean is_punct = STREQ (str, "punct");
1442 boolean is_space = STREQ (str, "space");
1443 boolean is_upper = STREQ (str, "upper");
1444 boolean is_xdigit = STREQ (str, "xdigit");
1446 if (!IS_CHAR_CLASS (str)) return REG_ECTYPE;
1448 /* Throw away the ] at the end of the character
1452 if (p == pend) return REG_EBRACK;
1454 for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
1456 if ( (is_alnum && isalnum (ch))
1457 || (is_alpha && isalpha (ch))
1458 || (is_blank && isblank (ch))
1459 || (is_cntrl && iscntrl (ch))
1460 || (is_digit && isdigit (ch))
1461 || (is_graph && isgraph (ch))
1462 || (is_lower && islower (ch))
1463 || (is_print && isprint (ch))
1464 || (is_punct && ispunct (ch))
1465 || (is_space && isspace (ch))
1466 || (is_upper && isupper (ch))
1467 || (is_xdigit && isxdigit (ch)))
1470 had_char_class = true;
1479 had_char_class = false;
1484 had_char_class = false;
1489 /* Discard any (non)matching list bytes that are all 0 at the
1490 end of the map. Decrease the map-length byte too. */
1491 while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
1499 if (syntax & RE_NO_BK_PARENS)
1506 if (syntax & RE_NO_BK_PARENS)
1513 if (syntax & RE_NEWLINE_ALT)
1520 if (syntax & RE_NO_BK_VBAR)
1527 if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
1528 goto handle_interval;
1534 if (p == pend) return REG_EESCAPE;
1536 /* Do not translate the character after the \, so that we can
1537 distinguish, e.g., \B from \b, even if we normally would
1538 translate, e.g., B to b. */
1544 if (syntax & RE_NO_BK_PARENS)
1545 goto normal_backslash;
1551 if (COMPILE_STACK_FULL)
1553 RETALLOC (compile_stack.stack, compile_stack.size << 1,
1554 compile_stack_elt_t);
1555 if (compile_stack.stack == NULL) return REG_ESPACE;
1557 compile_stack.size <<= 1;
1560 /* These are the values to restore when we hit end of this
1561 group. They are all relative offsets, so that if the
1562 whole pattern moves because of realloc, they will still
1564 COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
1565 COMPILE_STACK_TOP.fixup_alt_jump
1566 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
1567 COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
1568 COMPILE_STACK_TOP.regnum = regnum;
1570 /* We will eventually replace the 0 with the number of
1571 groups inner to this one. But do not push a
1572 start_memory for groups beyond the last one we can
1573 represent in the compiled pattern. */
1574 if (regnum <= MAX_REGNUM)
1576 COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
1577 BUF_PUSH_3 (start_memory, regnum, 0);
1580 compile_stack.avail++;
1589 if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
1591 if (COMPILE_STACK_EMPTY)
1592 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1593 goto normal_backslash;
1599 { /* Push a dummy failure point at the end of the
1600 alternative for a possible future
1601 `pop_failure_jump' to pop. See comments at
1602 `push_dummy_failure' in `re_match_2'. */
1603 BUF_PUSH (push_dummy_failure);
1605 /* We allocated space for this jump when we assigned
1606 to `fixup_alt_jump', in the `handle_alt' case below. */
1607 STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
1610 /* See similar code for backslashed left paren above. */
1611 if (COMPILE_STACK_EMPTY)
1612 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
1617 /* Since we just checked for an empty stack above, this
1618 ``can't happen''. */
1619 assert (compile_stack.avail != 0);
1621 /* We don't just want to restore into `regnum', because
1622 later groups should continue to be numbered higher,
1623 as in `(ab)c(de)' -- the second group is #2. */
1624 regnum_t this_group_regnum;
1626 compile_stack.avail--;
1627 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
1629 = COMPILE_STACK_TOP.fixup_alt_jump
1630 ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
1632 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
1633 this_group_regnum = COMPILE_STACK_TOP.regnum;
1635 /* We're at the end of the group, so now we know how many
1636 groups were inside this one. */
1637 if (this_group_regnum <= MAX_REGNUM)
1639 unsigned char *inner_group_loc
1640 = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
1642 *inner_group_loc = regnum - this_group_regnum;
1643 BUF_PUSH_3 (stop_memory, this_group_regnum,
1644 regnum - this_group_regnum);
1650 case '|': /* `\|'. */
1651 if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
1652 goto normal_backslash;
1654 if (syntax & RE_LIMITED_OPS)
1657 /* Insert before the previous alternative a jump which
1658 jumps to this alternative if the former fails. */
1659 GET_BUFFER_SPACE (3);
1660 INSERT_JUMP (on_failure_jump, begalt, b + 6);
1664 /* The alternative before this one has a jump after it
1665 which gets executed if it gets matched. Adjust that
1666 jump so it will jump to this alternative's analogous
1667 jump (put in below, which in turn will jump to the next
1668 (if any) alternative's such jump, etc.). The last such
1669 jump jumps to the correct final destination. A picture:
1675 If we are at `b,' then fixup_alt_jump right now points to a
1676 three-byte space after `a.' We'll put in the jump, set
1677 fixup_alt_jump to right after `b,' and leave behind three
1678 bytes which we'll fill in when we get to after `c.' */
1681 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
1683 /* Mark and leave space for a jump after this alternative,
1684 to be filled in later either by next alternative or
1685 when know we're at the end of a series of alternatives. */
1687 GET_BUFFER_SPACE (3);
1696 /* If \{ is a literal. */
1697 if (!(syntax & RE_INTERVALS)
1698 /* If we're at `\{' and it's not the open-interval
1700 || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
1701 || (p - 2 == pattern && p == pend))
1702 goto normal_backslash;
1706 /* If got here, then the syntax allows intervals. */
1708 /* At least (most) this many matches must be made. */
1709 int lower_bound = -1, upper_bound = -1;
1711 beg_interval = p - 1;
1715 if (syntax & RE_NO_BK_BRACES)
1716 goto unfetch_interval;
1721 GET_UNSIGNED_NUMBER (lower_bound);
1725 GET_UNSIGNED_NUMBER (upper_bound);
1726 if (upper_bound < 0) upper_bound = RE_DUP_MAX;
1729 /* Interval such as `{1}' => match exactly once. */
1730 upper_bound = lower_bound;
1732 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
1733 || lower_bound > upper_bound)
1735 if (syntax & RE_NO_BK_BRACES)
1736 goto unfetch_interval;
1741 if (!(syntax & RE_NO_BK_BRACES))
1743 if (c != '\\') return REG_EBRACE;
1750 if (syntax & RE_NO_BK_BRACES)
1751 goto unfetch_interval;
1756 /* We just parsed a valid interval. */
1758 /* If it's invalid to have no preceding re. */
1761 if (syntax & RE_CONTEXT_INVALID_OPS)
1763 else if (syntax & RE_CONTEXT_INDEP_OPS)
1766 goto unfetch_interval;
1769 /* If the upper bound is zero, don't want to succeed at
1770 all; jump from `laststart' to `b + 3', which will be
1771 the end of the buffer after we insert the jump. */
1772 if (upper_bound == 0)
1774 GET_BUFFER_SPACE (3);
1775 INSERT_JUMP (jump, laststart, b + 3);
1779 /* Otherwise, we have a nontrivial interval. When
1780 we're all done, the pattern will look like:
1781 set_number_at <jump count> <upper bound>
1782 set_number_at <succeed_n count> <lower bound>
1783 succeed_n <after jump addr> <succed_n count>
1785 jump_n <succeed_n addr> <jump count>
1786 (The upper bound and `jump_n' are omitted if
1787 `upper_bound' is 1, though.) */
1789 { /* If the upper bound is > 1, we need to insert
1790 more at the end of the loop. */
1791 unsigned nbytes = 10 + (upper_bound > 1) * 10;
1793 GET_BUFFER_SPACE (nbytes);
1795 /* Initialize lower bound of the `succeed_n', even
1796 though it will be set during matching by its
1797 attendant `set_number_at' (inserted next),
1798 because `re_compile_fastmap' needs to know.
1799 Jump to the `jump_n' we might insert below. */
1800 INSERT_JUMP2 (succeed_n, laststart,
1801 b + 5 + (upper_bound > 1) * 5,
1805 /* Code to initialize the lower bound. Insert
1806 before the `succeed_n'. The `5' is the last two
1807 bytes of this `set_number_at', plus 3 bytes of
1808 the following `succeed_n'. */
1809 insert_op2 (set_number_at, laststart, 5, lower_bound, b);
1812 if (upper_bound > 1)
1813 { /* More than one repetition is allowed, so
1814 append a backward jump to the `succeed_n'
1815 that starts this interval.
1817 When we've reached this during matching,
1818 we'll have matched the interval once, so
1819 jump back only `upper_bound - 1' times. */
1820 STORE_JUMP2 (jump_n, b, laststart + 5,
1824 /* The location we want to set is the second
1825 parameter of the `jump_n'; that is `b-2' as
1826 an absolute address. `laststart' will be
1827 the `set_number_at' we're about to insert;
1828 `laststart+3' the number to set, the source
1829 for the relative address. But we are
1830 inserting into the middle of the pattern --
1831 so everything is getting moved up by 5.
1832 Conclusion: (b - 2) - (laststart + 3) + 5,
1833 i.e., b - laststart.
1835 We insert this at the beginning of the loop
1836 so that if we fail during matching, we'll
1837 reinitialize the bounds. */
1838 insert_op2 (set_number_at, laststart, b - laststart,
1839 upper_bound - 1, b);
1844 beg_interval = NULL;
1849 /* If an invalid interval, match the characters as literals. */
1850 assert (beg_interval);
1852 beg_interval = NULL;
1854 /* normal_char and normal_backslash need `c'. */
1857 if (!(syntax & RE_NO_BK_BRACES))
1859 if (p > pattern && p[-1] == '\\')
1860 goto normal_backslash;
1865 /* There is no way to specify the before_dot and after_dot
1866 operators. rms says this is ok. --karl */
1874 BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
1880 BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
1887 BUF_PUSH (wordchar);
1893 BUF_PUSH (notwordchar);
1906 BUF_PUSH (wordbound);
1910 BUF_PUSH (notwordbound);
1921 case '1': case '2': case '3': case '4': case '5':
1922 case '6': case '7': case '8': case '9':
1923 if (syntax & RE_NO_BK_REFS)
1931 /* Can't back reference to a subexpression if inside of it. */
1932 if (group_in_compile_stack (compile_stack, c1))
1936 BUF_PUSH_2 (duplicate, c1);
1942 if (syntax & RE_BK_PLUS_QM)
1945 goto normal_backslash;
1949 /* You might think it would be useful for \ to mean
1950 not to translate; but if we don't translate it
1951 it will never match anything. */
1959 /* Expects the character in `c'. */
1961 /* If no exactn currently being built. */
1964 /* If last exactn not at current position. */
1965 || pending_exact + *pending_exact + 1 != b
1967 /* We have only one byte following the exactn for the count. */
1968 || *pending_exact == (1 << BYTEWIDTH) - 1
1970 /* If followed by a repetition operator. */
1971 || *p == '*' || *p == '^'
1972 || ((syntax & RE_BK_PLUS_QM)
1973 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
1974 : (*p == '+' || *p == '?'))
1975 || ((syntax & RE_INTERVALS)
1976 && ((syntax & RE_NO_BK_BRACES)
1978 : (p[0] == '\\' && p[1] == '{'))))
1980 /* Start building a new exactn. */
1984 BUF_PUSH_2 (exactn, 0);
1985 pending_exact = b - 1;
1992 } /* while p != pend */
1995 /* Through the pattern now. */
1998 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
2000 if (!COMPILE_STACK_EMPTY)
2003 free (compile_stack.stack);
2005 /* We have succeeded; set the length of the buffer. */
2006 bufp->used = b - bufp->buffer;
2011 DEBUG_PRINT1 ("\nCompiled pattern: ");
2012 print_compiled_pattern (bufp);
2017 } /* regex_compile */
2019 /* Subroutines for `regex_compile'. */
2021 /* Store OP at LOC followed by two-byte integer parameter ARG. */
2024 store_op1 (op, loc, arg)
2029 *loc = (unsigned char) op;
2030 STORE_NUMBER (loc + 1, arg);
2034 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */
2037 store_op2 (op, loc, arg1, arg2)
2042 *loc = (unsigned char) op;
2043 STORE_NUMBER (loc + 1, arg1);
2044 STORE_NUMBER (loc + 3, arg2);
2048 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
2049 for OP followed by two-byte integer parameter ARG. */
2052 insert_op1 (op, loc, arg, end)
2058 register unsigned char *pfrom = end;
2059 register unsigned char *pto = end + 3;
2061 while (pfrom != loc)
2064 store_op1 (op, loc, arg);
2068 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */
2071 insert_op2 (op, loc, arg1, arg2, end)
2077 register unsigned char *pfrom = end;
2078 register unsigned char *pto = end + 5;
2080 while (pfrom != loc)
2083 store_op2 (op, loc, arg1, arg2);
2087 /* P points to just after a ^ in PATTERN. Return true if that ^ comes
2088 after an alternative or a begin-subexpression. We assume there is at
2089 least one character before the ^. */
2092 at_begline_loc_p (pattern, p, syntax)
2093 const char *pattern, *p;
2094 reg_syntax_t syntax;
2096 const char *prev = p - 2;
2097 boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
2100 /* After a subexpression? */
2101 (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
2102 /* After an alternative? */
2103 || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
2107 /* The dual of at_begline_loc_p. This one is for $. We assume there is
2108 at least one character after the $, i.e., `P < PEND'. */
2111 at_endline_loc_p (p, pend, syntax)
2112 const char *p, *pend;
2115 const char *next = p;
2116 boolean next_backslash = *next == '\\';
2117 const char *next_next = p + 1 < pend ? p + 1 : NULL;
2120 /* Before a subexpression? */
2121 (syntax & RE_NO_BK_PARENS ? *next == ')'
2122 : next_backslash && next_next && *next_next == ')')
2123 /* Before an alternative? */
2124 || (syntax & RE_NO_BK_VBAR ? *next == '|'
2125 : next_backslash && next_next && *next_next == '|');
2129 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
2130 false if it's not. */
2133 group_in_compile_stack (compile_stack, regnum)
2134 compile_stack_type compile_stack;
2139 for (this_element = compile_stack.avail - 1;
2142 if (compile_stack.stack[this_element].regnum == regnum)
2149 /* Read the ending character of a range (in a bracket expression) from the
2150 uncompiled pattern *P_PTR (which ends at PEND). We assume the
2151 starting character is in `P[-2]'. (`P[-1]' is the character `-'.)
2152 Then we set the translation of all bits between the starting and
2153 ending characters (inclusive) in the compiled pattern B.
2155 Return an error code.
2157 We use these short variable names so we can use the same macros as
2158 `regex_compile' itself. */
2160 static reg_errcode_t
2161 compile_range (p_ptr, pend, translate, syntax, b)
2162 const char **p_ptr, *pend;
2164 reg_syntax_t syntax;
2169 const char *p = *p_ptr;
2171 /* Even though the pattern is a signed `char *', we need to fetch into
2172 `unsigned char's. Reason: if the high bit of the pattern character
2173 is set, the range endpoints will be negative if we fetch into a
2175 unsigned char range_end;
2176 unsigned char range_start = p[-2];
2181 PATFETCH (range_end);
2183 /* Have to increment the pointer into the pattern string, so the
2184 caller isn't still at the ending character. */
2187 /* If the start is after the end, the range is empty. */
2188 if (range_start > range_end)
2189 return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
2191 /* Here we see why `this_char' has to be larger than an `unsigned
2192 char' -- the range is inclusive, so if `range_end' == 0xff
2193 (assuming 8-bit characters), we would otherwise go into an infinite
2194 loop, since all characters <= 0xff. */
2195 for (this_char = range_start; this_char <= range_end; this_char++)
2197 SET_LIST_BIT (TRANSLATE (this_char));
2203 /* Failure stack declarations and macros; both re_compile_fastmap and
2204 re_match_2 use a failure stack. These have to be macros because of
2208 /* Number of failure points for which to initially allocate space
2209 when matching. If this number is exceeded, we allocate more
2210 space, so it is not a hard limit. */
2211 #ifndef INIT_FAILURE_ALLOC
2212 #define INIT_FAILURE_ALLOC 5
2215 /* Roughly the maximum number of failure points on the stack. Would be
2216 exactly that if always used MAX_FAILURE_SPACE each time we failed.
2217 This is a variable only so users of regex can assign to it; we never
2218 change it ourselves. */
2219 int re_max_failures = 2000;
2221 typedef const unsigned char *fail_stack_elt_t;
2225 fail_stack_elt_t *stack;
2227 unsigned avail; /* Offset of next open position. */
2230 #define FAIL_STACK_EMPTY() (fail_stack.avail == 0)
2231 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
2232 #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size)
2233 #define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail])
2236 /* Initialize `fail_stack'. Do `return -2' if the alloc fails. */
2238 #define INIT_FAIL_STACK() \
2240 fail_stack.stack = (fail_stack_elt_t *) \
2241 REGEX_ALLOCATE (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
2243 if (fail_stack.stack == NULL) \
2246 fail_stack.size = INIT_FAILURE_ALLOC; \
2247 fail_stack.avail = 0; \
2251 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
2253 Return 1 if succeeds, and 0 if either ran out of memory
2254 allocating space for it or it was already too large.
2256 REGEX_REALLOCATE requires `destination' be declared. */
2258 #define DOUBLE_FAIL_STACK(fail_stack) \
2259 ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \
2261 : ((fail_stack).stack = (fail_stack_elt_t *) \
2262 REGEX_REALLOCATE ((fail_stack).stack, \
2263 (fail_stack).size * sizeof (fail_stack_elt_t), \
2264 ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \
2266 (fail_stack).stack == NULL \
2268 : ((fail_stack).size <<= 1, \
2272 /* Push PATTERN_OP on FAIL_STACK.
2274 Return 1 if was able to do so and 0 if ran out of memory allocating
2276 #define PUSH_PATTERN_OP(pattern_op, fail_stack) \
2277 ((FAIL_STACK_FULL () \
2278 && !DOUBLE_FAIL_STACK (fail_stack)) \
2280 : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \
2283 /* This pushes an item onto the failure stack. Must be a four-byte
2284 value. Assumes the variable `fail_stack'. Probably should only
2285 be called from within `PUSH_FAILURE_POINT'. */
2286 #define PUSH_FAILURE_ITEM(item) \
2287 fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) item
2289 /* The complement operation. Assumes `fail_stack' is nonempty. */
2290 #define POP_FAILURE_ITEM() fail_stack.stack[--fail_stack.avail]
2292 /* Used to omit pushing failure point id's when we're not debugging. */
2294 #define DEBUG_PUSH PUSH_FAILURE_ITEM
2295 #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_ITEM ()
2297 #define DEBUG_PUSH(item)
2298 #define DEBUG_POP(item_addr)
2302 /* Push the information about the state we will need
2303 if we ever fail back to it.
2305 Requires variables fail_stack, regstart, regend, reg_info, and
2306 num_regs be declared. DOUBLE_FAIL_STACK requires `destination' be
2309 Does `return FAILURE_CODE' if runs out of memory. */
2311 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
2313 char *destination; \
2314 /* Must be int, so when we don't save any registers, the arithmetic \
2315 of 0 + -1 isn't done as unsigned. */ \
2318 DEBUG_STATEMENT (failure_id++); \
2319 DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \
2320 DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\
2321 DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\
2323 DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \
2324 DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \
2326 /* Ensure we have enough space allocated for what we will push. */ \
2327 while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \
2329 if (!DOUBLE_FAIL_STACK (fail_stack)) \
2330 return failure_code; \
2332 DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \
2333 (fail_stack).size); \
2334 DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\
2337 /* Push the info, starting with the registers. */ \
2338 DEBUG_PRINT1 ("\n"); \
2340 for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
2343 DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \
2344 DEBUG_STATEMENT (num_regs_pushed++); \
2346 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2347 PUSH_FAILURE_ITEM (regstart[this_reg]); \
2349 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2350 PUSH_FAILURE_ITEM (regend[this_reg]); \
2352 DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \
2353 DEBUG_PRINT2 (" match_null=%d", \
2354 REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \
2355 DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \
2356 DEBUG_PRINT2 (" matched_something=%d", \
2357 MATCHED_SOMETHING (reg_info[this_reg])); \
2358 DEBUG_PRINT2 (" ever_matched=%d", \
2359 EVER_MATCHED_SOMETHING (reg_info[this_reg])); \
2360 DEBUG_PRINT1 ("\n"); \
2361 PUSH_FAILURE_ITEM (reg_info[this_reg].word); \
2364 DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\
2365 PUSH_FAILURE_ITEM (lowest_active_reg); \
2367 DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\
2368 PUSH_FAILURE_ITEM (highest_active_reg); \
2370 DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \
2371 DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \
2372 PUSH_FAILURE_ITEM (pattern_place); \
2374 DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \
2375 DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \
2377 DEBUG_PRINT1 ("'\n"); \
2378 PUSH_FAILURE_ITEM (string_place); \
2380 DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \
2381 DEBUG_PUSH (failure_id); \
2384 /* This is the number of items that are pushed and popped on the stack
2385 for each register. */
2386 #define NUM_REG_ITEMS 3
2388 /* Individual items aside from the registers. */
2390 #define NUM_NONREG_ITEMS 5 /* Includes failure point id. */
2392 #define NUM_NONREG_ITEMS 4
2395 /* We push at most this many items on the stack. */
2396 #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
2398 /* We actually push this many items. */
2399 #define NUM_FAILURE_ITEMS \
2400 ((highest_active_reg - lowest_active_reg + 1) * NUM_REG_ITEMS \
2403 /* How many items can still be added to the stack without overflowing it. */
2404 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
2407 /* Pops what PUSH_FAIL_STACK pushes.
2409 We restore into the parameters, all of which should be lvalues:
2410 STR -- the saved data position.
2411 PAT -- the saved pattern position.
2412 LOW_REG, HIGH_REG -- the highest and lowest active registers.
2413 REGSTART, REGEND -- arrays of string positions.
2414 REG_INFO -- array of information about each subexpression.
2416 Also assumes the variables `fail_stack' and (if debugging), `bufp',
2417 `pend', `string1', `size1', `string2', and `size2'. */
2419 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
2421 DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \
2423 const unsigned char *string_temp; \
2425 assert (!FAIL_STACK_EMPTY ()); \
2427 /* Remove failure points and point to how many regs pushed. */ \
2428 DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \
2429 DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \
2430 DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \
2432 assert (fail_stack.avail >= NUM_NONREG_ITEMS); \
2434 DEBUG_POP (&failure_id); \
2435 DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \
2437 /* If the saved string location is NULL, it came from an \
2438 on_failure_keep_string_jump opcode, and we want to throw away the \
2439 saved NULL, thus retaining our current position in the string. */ \
2440 string_temp = POP_FAILURE_ITEM (); \
2441 if (string_temp != NULL) \
2442 str = (const char *) string_temp; \
2444 DEBUG_PRINT2 (" Popping string 0x%x: `", str); \
2445 DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \
2446 DEBUG_PRINT1 ("'\n"); \
2448 pat = (unsigned char *) POP_FAILURE_ITEM (); \
2449 DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \
2450 DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \
2452 /* Restore register info. */ \
2453 high_reg = (unsigned) POP_FAILURE_ITEM (); \
2454 DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \
2456 low_reg = (unsigned) POP_FAILURE_ITEM (); \
2457 DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \
2459 for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \
2461 DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \
2463 reg_info[this_reg].word = POP_FAILURE_ITEM (); \
2464 DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \
2466 regend[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2467 DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \
2469 regstart[this_reg] = (const char *) POP_FAILURE_ITEM (); \
2470 DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \
2472 } /* POP_FAILURE_POINT */
2474 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
2475 BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible
2476 characters can start a string that matches the pattern. This fastmap
2477 is used by re_search to skip quickly over impossible starting points.
2479 The caller must supply the address of a (1 << BYTEWIDTH)-byte data
2480 area as BUFP->fastmap.
2482 We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
2485 Returns 0 if we succeed, -2 if an internal error. */
2488 re_compile_fastmap (bufp)
2489 struct re_pattern_buffer *bufp;
2492 fail_stack_type fail_stack;
2493 #ifndef REGEX_MALLOC
2496 /* We don't push any register information onto the failure stack. */
2497 unsigned num_regs = 0;
2499 register char *fastmap = bufp->fastmap;
2500 unsigned char *pattern = bufp->buffer;
2501 unsigned long size = bufp->used;
2502 const unsigned char *p = pattern;
2503 register unsigned char *pend = pattern + size;
2505 /* Assume that each path through the pattern can be null until
2506 proven otherwise. We set this false at the bottom of switch
2507 statement, to which we get only if a particular path doesn't
2508 match the empty string. */
2509 boolean path_can_be_null = true;
2511 /* We aren't doing a `succeed_n' to begin with. */
2512 boolean succeed_n_p = false;
2514 assert (fastmap != NULL && p != NULL);
2517 bzero (fastmap, 1 << BYTEWIDTH); /* Assume nothing's valid. */
2518 bufp->fastmap_accurate = 1; /* It will be when we're done. */
2519 bufp->can_be_null = 0;
2521 while (p != pend || !FAIL_STACK_EMPTY ())
2525 bufp->can_be_null |= path_can_be_null;
2527 /* Reset for next path. */
2528 path_can_be_null = true;
2530 p = fail_stack.stack[--fail_stack.avail];
2533 /* We should never be about to go beyond the end of the pattern. */
2536 #ifdef SWITCH_ENUM_BUG
2537 switch ((int) ((re_opcode_t) *p++))
2539 switch ((re_opcode_t) *p++)
2543 /* I guess the idea here is to simply not bother with a fastmap
2544 if a backreference is used, since it's too hard to figure out
2545 the fastmap for the corresponding group. Setting
2546 `can_be_null' stops `re_search_2' from using the fastmap, so
2547 that is all we do. */
2549 bufp->can_be_null = 1;
2553 /* Following are the cases which match a character. These end
2562 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2563 if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
2569 /* Chars beyond end of map must be allowed. */
2570 for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
2573 for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
2574 if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
2580 for (j = 0; j < (1 << BYTEWIDTH); j++)
2581 if (SYNTAX (j) == Sword)
2587 for (j = 0; j < (1 << BYTEWIDTH); j++)
2588 if (SYNTAX (j) != Sword)
2594 /* `.' matches anything ... */
2595 for (j = 0; j < (1 << BYTEWIDTH); j++)
2598 /* ... except perhaps newline. */
2599 if (!(bufp->syntax & RE_DOT_NEWLINE))
2602 /* Return if we have already set `can_be_null'; if we have,
2603 then the fastmap is irrelevant. Something's wrong here. */
2604 else if (bufp->can_be_null)
2607 /* Otherwise, have to check alternative paths. */
2614 for (j = 0; j < (1 << BYTEWIDTH); j++)
2615 if (SYNTAX (j) == (enum syntaxcode) k)
2622 for (j = 0; j < (1 << BYTEWIDTH); j++)
2623 if (SYNTAX (j) != (enum syntaxcode) k)
2628 /* All cases after this match the empty string. These end with
2636 #endif /* not emacs */
2648 case push_dummy_failure:
2653 case pop_failure_jump:
2654 case maybe_pop_jump:
2657 case dummy_failure_jump:
2658 EXTRACT_NUMBER_AND_INCR (j, p);
2663 /* Jump backward implies we just went through the body of a
2664 loop and matched nothing. Opcode jumped to should be
2665 `on_failure_jump' or `succeed_n'. Just treat it like an
2666 ordinary jump. For a * loop, it has pushed its failure
2667 point already; if so, discard that as redundant. */
2668 if ((re_opcode_t) *p != on_failure_jump
2669 && (re_opcode_t) *p != succeed_n)
2673 EXTRACT_NUMBER_AND_INCR (j, p);
2676 /* If what's on the stack is where we are now, pop it. */
2677 if (!FAIL_STACK_EMPTY ()
2678 && fail_stack.stack[fail_stack.avail - 1] == p)
2684 case on_failure_jump:
2685 case on_failure_keep_string_jump:
2686 handle_on_failure_jump:
2687 EXTRACT_NUMBER_AND_INCR (j, p);
2689 /* For some patterns, e.g., `(a?)?', `p+j' here points to the
2690 end of the pattern. We don't want to push such a point,
2691 since when we restore it above, entering the switch will
2692 increment `p' past the end of the pattern. We don't need
2693 to push such a point since we obviously won't find any more
2694 fastmap entries beyond `pend'. Such a pattern can match
2695 the null string, though. */
2698 if (!PUSH_PATTERN_OP (p + j, fail_stack))
2702 bufp->can_be_null = 1;
2706 EXTRACT_NUMBER_AND_INCR (k, p); /* Skip the n. */
2707 succeed_n_p = false;
2714 /* Get to the number of times to succeed. */
2717 /* Increment p past the n for when k != 0. */
2718 EXTRACT_NUMBER_AND_INCR (k, p);
2722 succeed_n_p = true; /* Spaghetti code alert. */
2723 goto handle_on_failure_jump;
2740 abort (); /* We have listed all the cases. */
2743 /* Getting here means we have found the possible starting
2744 characters for one path of the pattern -- and that the empty
2745 string does not match. We need not follow this path further.
2746 Instead, look at the next alternative (remembered on the
2747 stack), or quit if no more. The test at the top of the loop
2748 does these things. */
2749 path_can_be_null = false;
2753 /* Set `can_be_null' for the last path (also the first path, if the
2754 pattern is empty). */
2755 bufp->can_be_null |= path_can_be_null;
2757 } /* re_compile_fastmap */
2759 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
2760 ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use
2761 this memory for recording register information. STARTS and ENDS
2762 must be allocated using the malloc library routine, and must each
2763 be at least NUM_REGS * sizeof (regoff_t) bytes long.
2765 If NUM_REGS == 0, then subsequent matches should allocate their own
2768 Unless this function is called, the first search or match using
2769 PATTERN_BUFFER will allocate its own register data, without
2770 freeing the old data. */
2773 re_set_registers (bufp, regs, num_regs, starts, ends)
2774 struct re_pattern_buffer *bufp;
2775 struct re_registers *regs;
2777 regoff_t *starts, *ends;
2781 bufp->regs_allocated = REGS_REALLOCATE;
2782 regs->num_regs = num_regs;
2783 regs->start = starts;
2788 bufp->regs_allocated = REGS_UNALLOCATED;
2790 regs->start = regs->end = (regoff_t) 0;
2794 /* Searching routines. */
2796 /* Like re_search_2, below, but only one string is specified, and
2797 doesn't let you say where to stop matching. */
2800 re_search (bufp, string, size, startpos, range, regs)
2801 struct re_pattern_buffer *bufp;
2803 int size, startpos, range;
2804 struct re_registers *regs;
2806 return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
2811 /* Using the compiled pattern in BUFP->buffer, first tries to match the
2812 virtual concatenation of STRING1 and STRING2, starting first at index
2813 STARTPOS, then at STARTPOS + 1, and so on.
2815 STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
2817 RANGE is how far to scan while trying to match. RANGE = 0 means try
2818 only at STARTPOS; in general, the last start tried is STARTPOS +
2821 In REGS, return the indices of the virtual concatenation of STRING1
2822 and STRING2 that matched the entire BUFP->buffer and its contained
2825 Do not consider matching one past the index STOP in the virtual
2826 concatenation of STRING1 and STRING2.
2828 We return either the position in the strings at which the match was
2829 found, -1 if no match, or -2 if error (such as failure
2833 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
2834 struct re_pattern_buffer *bufp;
2835 const char *string1, *string2;
2839 struct re_registers *regs;
2843 register char *fastmap = bufp->fastmap;
2844 register char *translate = bufp->translate;
2845 int total_size = size1 + size2;
2846 int endpos = startpos + range;
2848 /* Check for out-of-range STARTPOS. */
2849 if (startpos < 0 || startpos > total_size)
2852 /* Fix up RANGE if it might eventually take us outside
2853 the virtual concatenation of STRING1 and STRING2. */
2855 range = -1 - startpos;
2856 else if (endpos > total_size)
2857 range = total_size - startpos;
2859 /* Update the fastmap now if not correct already. */
2860 if (fastmap && !bufp->fastmap_accurate)
2861 if (re_compile_fastmap (bufp) == -2)
2864 /* If the search isn't to be a backwards one, don't waste time in a
2865 long search for a pattern that says it is anchored. */
2866 if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf
2877 /* If a fastmap is supplied, skip quickly over characters that
2878 cannot be the start of a match. If the pattern can match the
2879 null string, however, we don't need to skip characters; we want
2880 the first null string. */
2881 if (fastmap && startpos < total_size && !bufp->can_be_null)
2883 if (range > 0) /* Searching forwards. */
2885 register const char *d;
2886 register int lim = 0;
2889 if (startpos < size1 && startpos + range >= size1)
2890 lim = range - (size1 - startpos);
2892 d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
2894 /* Written out as an if-else to avoid testing `translate'
2898 && !fastmap[(unsigned char) translate[*d++]])
2901 while (range > lim && !fastmap[(unsigned char) *d++])
2904 startpos += irange - range;
2906 else /* Searching backwards. */
2908 register char c = (size1 == 0 || startpos >= size1
2909 ? string2[startpos - size1]
2910 : string1[startpos]);
2912 if (!fastmap[TRANSLATE (c)])
2917 /* If can't match the null string, and that's all we have left, fail. */
2918 if (range >= 0 && startpos == total_size && fastmap
2919 && !bufp->can_be_null)
2922 val = re_match_2 (bufp, string1, size1, string2, size2,
2923 startpos, regs, stop);
2947 /* Declarations and macros for re_match_2. */
2949 static int bcmp_translate ();
2950 static boolean alt_match_null_string_p (),
2951 common_op_match_null_string_p (),
2952 group_match_null_string_p ();
2954 /* Structure for per-register (a.k.a. per-group) information.
2955 This must not be longer than one word, because we push this value
2956 onto the failure stack. Other register information, such as the
2957 starting and ending positions (which are addresses), and the list of
2958 inner groups (which is a bits list) are maintained in separate
2961 We are making a (strictly speaking) nonportable assumption here: that
2962 the compiler will pack our bit fields into something that fits into
2963 the type of `word', i.e., is something that fits into one item on the
2967 fail_stack_elt_t word;
2970 /* This field is one if this group can match the empty string,
2971 zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */
2972 #define MATCH_NULL_UNSET_VALUE 3
2973 unsigned match_null_string_p : 2;
2974 unsigned is_active : 1;
2975 unsigned matched_something : 1;
2976 unsigned ever_matched_something : 1;
2978 } register_info_type;
2980 #define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p)
2981 #define IS_ACTIVE(R) ((R).bits.is_active)
2982 #define MATCHED_SOMETHING(R) ((R).bits.matched_something)
2983 #define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something)
2986 /* Call this when have matched something; it sets `matched' flags for the
2987 registers corresponding to the group of which we currently are inside.
2988 Also records whether this group ever matched something. We only care
2989 about this information at `stop_memory', and then only about the
2990 previous time through the loop (if the group is starred or whatever).
2991 So it is ok to clear all the nonactive registers here. */
2992 #define SET_REGS_MATCHED() \
2996 for (r = lowest_active_reg; r <= highest_active_reg; r++) \
2998 MATCHED_SOMETHING (reg_info[r]) \
2999 = EVER_MATCHED_SOMETHING (reg_info[r]) \
3006 /* This converts PTR, a pointer into one of the search strings `string1'
3007 and `string2' into an offset from the beginning of that string. */
3008 #define POINTER_TO_OFFSET(ptr) \
3009 (FIRST_STRING_P (ptr) ? (ptr) - string1 : (ptr) - string2 + size1)
3011 /* Registers are set to a sentinel when they haven't yet matched. */
3012 #define REG_UNSET_VALUE ((char *) -1)
3013 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
3016 /* Macros for dealing with the split strings in re_match_2. */
3018 #define MATCHING_IN_FIRST_STRING (dend == end_match_1)
3020 /* Call before fetching a character with *d. This switches over to
3021 string2 if necessary. */
3022 #define PREFETCH() \
3025 /* End of string2 => fail. */ \
3026 if (dend == end_match_2) \
3028 /* End of string1 => advance to string2. */ \
3030 dend = end_match_2; \
3034 /* Test if at very beginning or at very end of the virtual concatenation
3035 of `string1' and `string2'. If only one string, it's `string2'. */
3036 #define AT_STRINGS_BEG() (d == (size1 ? string1 : string2) || !size2)
3037 #define AT_STRINGS_END() (d == end2)
3040 /* Test if D points to a character which is word-constituent. We have
3041 two special cases to check for: if past the end of string1, look at
3042 the first character in string2; and if before the beginning of
3043 string2, look at the last character in string1.
3045 Assumes `string1' exists, so use in conjunction with AT_STRINGS_BEG (). */
3046 #define LETTER_P(d) \
3047 (SYNTAX ((d) == end1 ? *string2 \
3048 : (d) == string2 - 1 ? *(end1 - 1) : *(d)) == Sword)
3050 /* Test if the character before D and the one at D differ with respect
3051 to being word-constituent. */
3052 #define AT_WORD_BOUNDARY(d) \
3053 (AT_STRINGS_BEG () || AT_STRINGS_END () || LETTER_P (d - 1) != LETTER_P (d))
3056 /* Free everything we malloc. */
3058 #define FREE_VAR(var) if (var) free (var); var = NULL
3059 #define FREE_VARIABLES() \
3061 FREE_VAR (fail_stack.stack); \
3062 FREE_VAR (regstart); \
3063 FREE_VAR (regend); \
3064 FREE_VAR (old_regstart); \
3065 FREE_VAR (old_regend); \
3066 FREE_VAR (best_regstart); \
3067 FREE_VAR (best_regend); \
3068 FREE_VAR (reg_info); \
3069 FREE_VAR (reg_dummy); \
3070 FREE_VAR (reg_info_dummy); \
3072 #else /* not REGEX_MALLOC */
3073 /* Some MIPS systems (at least) want this to free alloca'd storage. */
3074 #define FREE_VARIABLES() alloca (0)
3075 #endif /* not REGEX_MALLOC */
3078 /* These values must meet several constraints. They must not be valid
3079 register values; since we have a limit of 255 registers (because
3080 we use only one byte in the pattern for the register number), we can
3081 use numbers larger than 255. They must differ by 1, because of
3082 NUM_FAILURE_ITEMS above. And the value for the lowest register must
3083 be larger than the value for the highest register, so we do not try
3084 to actually save any registers when none are active. */
3085 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
3086 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
3088 /* Matching routines. */
3090 #ifndef emacs /* Emacs never uses this. */
3091 /* re_match is like re_match_2 except it takes only a single string. */
3094 re_match (bufp, string, size, pos, regs)
3095 struct re_pattern_buffer *bufp;
3098 struct re_registers *regs;
3100 return re_match_2 (bufp, NULL, 0, string, size, pos, regs, size);
3102 #endif /* not emacs */
3105 /* re_match_2 matches the compiled pattern in BUFP against the
3106 the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
3107 and SIZE2, respectively). We start matching at POS, and stop
3110 If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
3111 store offsets for the substring each group matched in REGS. See the
3112 documentation for exactly how many groups we fill.
3114 We return -1 if no match, -2 if an internal error (such as the
3115 failure stack overflowing). Otherwise, we return the length of the
3116 matched substring. */
3119 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
3120 struct re_pattern_buffer *bufp;
3121 const char *string1, *string2;
3124 struct re_registers *regs;
3127 /* General temporaries. */
3131 /* Just past the end of the corresponding string. */
3132 const char *end1, *end2;
3134 /* Pointers into string1 and string2, just past the last characters in
3135 each to consider matching. */
3136 const char *end_match_1, *end_match_2;
3138 /* Where we are in the data, and the end of the current string. */
3139 const char *d, *dend;
3141 /* Where we are in the pattern, and the end of the pattern. */
3142 unsigned char *p = bufp->buffer;
3143 register unsigned char *pend = p + bufp->used;
3145 /* We use this to map every character in the string. */
3146 char *translate = bufp->translate;
3148 /* Failure point stack. Each place that can handle a failure further
3149 down the line pushes a failure point on this stack. It consists of
3150 restart, regend, and reg_info for all registers corresponding to
3151 the subexpressions we're currently inside, plus the number of such
3152 registers, and, finally, two char *'s. The first char * is where
3153 to resume scanning the pattern; the second one is where to resume
3154 scanning the strings. If the latter is zero, the failure point is
3155 a ``dummy''; if a failure happens and the failure point is a dummy,
3156 it gets discarded and the next next one is tried. */
3157 fail_stack_type fail_stack;
3159 static unsigned failure_id = 0;
3162 /* We fill all the registers internally, independent of what we
3163 return, for use in backreferences. The number here includes
3164 an element for register zero. */
3165 unsigned num_regs = bufp->re_nsub + 1;
3167 /* The currently active registers. */
3168 unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3169 unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3171 /* Information on the contents of registers. These are pointers into
3172 the input strings; they record just what was matched (on this
3173 attempt) by a subexpression part of the pattern, that is, the
3174 regnum-th regstart pointer points to where in the pattern we began
3175 matching and the regnum-th regend points to right after where we
3176 stopped matching the regnum-th subexpression. (The zeroth register
3177 keeps track of what the whole pattern matches.) */
3178 const char **regstart, **regend;
3180 /* If a group that's operated upon by a repetition operator fails to
3181 match anything, then the register for its start will need to be
3182 restored because it will have been set to wherever in the string we
3183 are when we last see its open-group operator. Similarly for a
3185 const char **old_regstart, **old_regend;
3187 /* The is_active field of reg_info helps us keep track of which (possibly
3188 nested) subexpressions we are currently in. The matched_something
3189 field of reg_info[reg_num] helps us tell whether or not we have
3190 matched any of the pattern so far this time through the reg_num-th
3191 subexpression. These two fields get reset each time through any
3192 loop their register is in. */
3193 register_info_type *reg_info;
3195 /* The following record the register info as found in the above
3196 variables when we find a match better than any we've seen before.
3197 This happens as we backtrack through the failure points, which in
3198 turn happens only if we have not yet matched the entire string. */
3199 unsigned best_regs_set = false;
3200 const char **best_regstart, **best_regend;
3202 /* Logically, this is `best_regend[0]'. But we don't want to have to
3203 allocate space for that if we're not allocating space for anything
3204 else (see below). Also, we never need info about register 0 for
3205 any of the other register vectors, and it seems rather a kludge to
3206 treat `best_regend' differently than the rest. So we keep track of
3207 the end of the best match so far in a separate variable. We
3208 initialize this to NULL so that when we backtrack the first time
3209 and need to test it, it's not garbage. */
3210 const char *match_end = NULL;
3212 /* Used when we pop values we don't care about. */
3213 const char **reg_dummy;
3214 register_info_type *reg_info_dummy;
3217 /* Counts the total number of registers pushed. */
3218 unsigned num_regs_pushed = 0;
3221 DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
3225 /* Do not bother to initialize all the register variables if there are
3226 no groups in the pattern, as it takes a fair amount of time. If
3227 there are groups, we include space for register 0 (the whole
3228 pattern), even though we never use it, since it simplifies the
3229 array indexing. We should fix this. */
3232 regstart = REGEX_TALLOC (num_regs, const char *);
3233 regend = REGEX_TALLOC (num_regs, const char *);
3234 old_regstart = REGEX_TALLOC (num_regs, const char *);
3235 old_regend = REGEX_TALLOC (num_regs, const char *);
3236 best_regstart = REGEX_TALLOC (num_regs, const char *);
3237 best_regend = REGEX_TALLOC (num_regs, const char *);
3238 reg_info = REGEX_TALLOC (num_regs, register_info_type);
3239 reg_dummy = REGEX_TALLOC (num_regs, const char *);
3240 reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
3242 if (!(regstart && regend && old_regstart && old_regend && reg_info
3243 && best_regstart && best_regend && reg_dummy && reg_info_dummy))
3252 /* We must initialize all our variables to NULL, so that
3253 `FREE_VARIABLES' doesn't try to free them. Too bad this isn't
3254 Lisp, so we could have a list of variables. As it is, */
3255 regstart = regend = old_regstart = old_regend = best_regstart
3256 = best_regend = reg_dummy = NULL;
3257 reg_info = reg_info_dummy = (register_info_type *) NULL;
3259 #endif /* REGEX_MALLOC */
3261 /* The starting position is bogus. */
3262 if (pos < 0 || pos > size1 + size2)
3268 /* Initialize subexpression text positions to -1 to mark ones that no
3269 start_memory/stop_memory has been seen for. Also initialize the
3270 register information struct. */
3271 for (mcnt = 1; mcnt < num_regs; mcnt++)
3273 regstart[mcnt] = regend[mcnt]
3274 = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
3276 REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
3277 IS_ACTIVE (reg_info[mcnt]) = 0;
3278 MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3279 EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
3282 /* We move `string1' into `string2' if the latter's empty -- but not if
3283 `string1' is null. */
3284 if (size2 == 0 && string1 != NULL)
3291 end1 = string1 + size1;
3292 end2 = string2 + size2;
3294 /* Compute where to stop matching, within the two strings. */
3297 end_match_1 = string1 + stop;
3298 end_match_2 = string2;
3303 end_match_2 = string2 + stop - size1;
3306 /* `p' scans through the pattern as `d' scans through the data.
3307 `dend' is the end of the input string that `d' points within. `d'
3308 is advanced into the following input string whenever necessary, but
3309 this happens before fetching; therefore, at the beginning of the
3310 loop, `d' can be pointing at the end of a string, but it cannot
3312 if (size1 > 0 && pos <= size1)
3319 d = string2 + pos - size1;
3323 DEBUG_PRINT1 ("The compiled pattern is: ");
3324 DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
3325 DEBUG_PRINT1 ("The string to match is: `");
3326 DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
3327 DEBUG_PRINT1 ("'\n");
3329 /* This loops over pattern commands. It exits by returning from the
3330 function if the match is complete, or it drops through if the match
3331 fails at this starting point in the input data. */
3334 DEBUG_PRINT2 ("\n0x%x: ", p);
3337 { /* End of pattern means we might have succeeded. */
3338 DEBUG_PRINT1 ("End of pattern: ");
3339 /* If not end of string, try backtracking. Otherwise done. */
3340 if (d != end_match_2)
3342 DEBUG_PRINT1 ("backtracking.\n");
3344 if (!FAIL_STACK_EMPTY ())
3345 { /* More failure points to try. */
3346 boolean same_str_p = (FIRST_STRING_P (match_end)
3347 == MATCHING_IN_FIRST_STRING);
3349 /* If exceeds best match so far, save it. */
3351 || (same_str_p && d > match_end)
3352 || (!same_str_p && !MATCHING_IN_FIRST_STRING))
3354 best_regs_set = true;
3357 DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
3359 for (mcnt = 1; mcnt < num_regs; mcnt++)
3361 best_regstart[mcnt] = regstart[mcnt];
3362 best_regend[mcnt] = regend[mcnt];
3368 /* If no failure points, don't restore garbage. */
3369 else if (best_regs_set)
3372 /* Restore best match. It may happen that `dend ==
3373 end_match_1' while the restored d is in string2.
3374 For example, the pattern `x.*y.*z' against the
3375 strings `x-' and `y-z-', if the two strings are
3376 not consecutive in memory. */
3378 dend = ((d >= string1 && d <= end1)
3379 ? end_match_1 : end_match_2);
3381 for (mcnt = 1; mcnt < num_regs; mcnt++)
3383 regstart[mcnt] = best_regstart[mcnt];
3384 regend[mcnt] = best_regend[mcnt];
3387 } /* d != end_match_2 */
3389 DEBUG_PRINT1 ("\nAccepting match.\n");
3391 /* If caller wants register contents data back, do it. */
3392 if (regs && !bufp->no_sub)
3394 /* Have the register data arrays been allocated? */
3395 if (bufp->regs_allocated == REGS_UNALLOCATED)
3396 { /* No. So allocate them with malloc. We need one
3397 extra element beyond `num_regs' for the `-1' marker
3399 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
3400 regs->start = TALLOC (regs->num_regs, regoff_t);
3401 regs->end = TALLOC (regs->num_regs, regoff_t);
3402 if (regs->start == NULL || regs->end == NULL)
3404 bufp->regs_allocated = REGS_REALLOCATE;
3406 else if (bufp->regs_allocated == REGS_REALLOCATE)
3407 { /* Yes. If we need more elements than were already
3408 allocated, reallocate them. If we need fewer, just
3410 if (regs->num_regs < num_regs + 1)
3412 regs->num_regs = num_regs + 1;
3413 RETALLOC (regs->start, regs->num_regs, regoff_t);
3414 RETALLOC (regs->end, regs->num_regs, regoff_t);
3415 if (regs->start == NULL || regs->end == NULL)
3420 assert (bufp->regs_allocated == REGS_FIXED);
3422 /* Convert the pointer data in `regstart' and `regend' to
3423 indices. Register zero has to be set differently,
3424 since we haven't kept track of any info for it. */
3425 if (regs->num_regs > 0)
3427 regs->start[0] = pos;
3428 regs->end[0] = (MATCHING_IN_FIRST_STRING ? d - string1
3429 : d - string2 + size1);
3432 /* Go through the first `min (num_regs, regs->num_regs)'
3433 registers, since that is all we initialized. */
3434 for (mcnt = 1; mcnt < MIN (num_regs, regs->num_regs); mcnt++)
3436 if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
3437 regs->start[mcnt] = regs->end[mcnt] = -1;
3440 regs->start[mcnt] = POINTER_TO_OFFSET (regstart[mcnt]);
3441 regs->end[mcnt] = POINTER_TO_OFFSET (regend[mcnt]);
3445 /* If the regs structure we return has more elements than
3446 were in the pattern, set the extra elements to -1. If
3447 we (re)allocated the registers, this is the case,
3448 because we always allocate enough to have at least one
3450 for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++)
3451 regs->start[mcnt] = regs->end[mcnt] = -1;
3452 } /* regs && !bufp->no_sub */
3455 DEBUG_PRINT2 ("%d registers pushed.\n", num_regs_pushed);
3457 mcnt = d - pos - (MATCHING_IN_FIRST_STRING
3461 DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
3466 /* Otherwise match next pattern command. */
3467 #ifdef SWITCH_ENUM_BUG
3468 switch ((int) ((re_opcode_t) *p++))
3470 switch ((re_opcode_t) *p++)
3473 /* Ignore these. Used to ignore the n of succeed_n's which
3474 currently have n == 0. */
3476 DEBUG_PRINT1 ("EXECUTING no_op.\n");
3480 /* Match the next n pattern characters exactly. The following
3481 byte in the pattern defines n, and the n bytes after that
3482 are the characters to match. */
3485 DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
3487 /* This is written out as an if-else so we don't waste time
3488 testing `translate' inside the loop. */
3494 if (translate[(unsigned char) *d++] != (char) *p++)
3504 if (*d++ != (char) *p++) goto fail;
3508 SET_REGS_MATCHED ();
3512 /* Match any character except possibly a newline or a null. */
3514 DEBUG_PRINT1 ("EXECUTING anychar.\n");
3518 if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
3519 || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
3522 SET_REGS_MATCHED ();
3523 DEBUG_PRINT2 (" Matched `%d'.\n", *d);
3531 register unsigned char c;
3532 boolean not = (re_opcode_t) *(p - 1) == charset_not;
3534 DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
3537 c = TRANSLATE (*d); /* The character to match. */
3539 /* Cast to `unsigned' instead of `unsigned char' in case the
3540 bit list is a full 32 bytes long. */
3541 if (c < (unsigned) (*p * BYTEWIDTH)
3542 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3547 if (!not) goto fail;
3549 SET_REGS_MATCHED ();
3555 /* The beginning of a group is represented by start_memory.
3556 The arguments are the register number in the next byte, and the
3557 number of groups inner to this one in the next. The text
3558 matched within the group is recorded (in the internal
3559 registers data structure) under the register number. */
3561 DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
3563 /* Find out if this group can match the empty string. */
3564 p1 = p; /* To send to group_match_null_string_p. */
3566 if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
3567 REG_MATCH_NULL_STRING_P (reg_info[*p])
3568 = group_match_null_string_p (&p1, pend, reg_info);
3570 /* Save the position in the string where we were the last time
3571 we were at this open-group operator in case the group is
3572 operated upon by a repetition operator, e.g., with `(a*)*b'
3573 against `ab'; then we want to ignore where we are now in
3574 the string in case this attempt to match fails. */
3575 old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3576 ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
3578 DEBUG_PRINT2 (" old_regstart: %d\n",
3579 POINTER_TO_OFFSET (old_regstart[*p]));
3582 DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
3584 IS_ACTIVE (reg_info[*p]) = 1;
3585 MATCHED_SOMETHING (reg_info[*p]) = 0;
3587 /* This is the new highest active register. */
3588 highest_active_reg = *p;
3590 /* If nothing was active before, this is the new lowest active
3592 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3593 lowest_active_reg = *p;
3595 /* Move past the register number and inner group count. */
3600 /* The stop_memory opcode represents the end of a group. Its
3601 arguments are the same as start_memory's: the register
3602 number, and the number of inner groups. */
3604 DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
3606 /* We need to save the string position the last time we were at
3607 this close-group operator in case the group is operated
3608 upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
3609 against `aba'; then we want to ignore where we are now in
3610 the string in case this attempt to match fails. */
3611 old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
3612 ? REG_UNSET (regend[*p]) ? d : regend[*p]
3614 DEBUG_PRINT2 (" old_regend: %d\n",
3615 POINTER_TO_OFFSET (old_regend[*p]));
3618 DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
3620 /* This register isn't active anymore. */
3621 IS_ACTIVE (reg_info[*p]) = 0;
3623 /* If this was the only register active, nothing is active
3625 if (lowest_active_reg == highest_active_reg)
3627 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3628 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3631 { /* We must scan for the new highest active register, since
3632 it isn't necessarily one less than now: consider
3633 (a(b)c(d(e)f)g). When group 3 ends, after the f), the
3634 new highest active register is 1. */
3635 unsigned char r = *p - 1;
3636 while (r > 0 && !IS_ACTIVE (reg_info[r]))
3639 /* If we end up at register zero, that means that we saved
3640 the registers as the result of an `on_failure_jump', not
3641 a `start_memory', and we jumped to past the innermost
3642 `stop_memory'. For example, in ((.)*) we save
3643 registers 1 and 2 as a result of the *, but when we pop
3644 back to the second ), we are at the stop_memory 1.
3645 Thus, nothing is active. */
3648 lowest_active_reg = NO_LOWEST_ACTIVE_REG;
3649 highest_active_reg = NO_HIGHEST_ACTIVE_REG;
3652 highest_active_reg = r;
3655 /* If just failed to match something this time around with a
3656 group that's operated on by a repetition operator, try to
3657 force exit from the ``loop,'' and restore the register
3658 information for this group that we had before trying this
3660 if ((!MATCHED_SOMETHING (reg_info[*p])
3661 || (re_opcode_t) p[-3] == start_memory)
3664 boolean is_a_jump_n = false;
3668 switch ((re_opcode_t) *p1++)
3672 case pop_failure_jump:
3673 case maybe_pop_jump:
3675 case dummy_failure_jump:
3676 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3686 /* If the next operation is a jump backwards in the pattern
3687 to an on_failure_jump right before the start_memory
3688 corresponding to this stop_memory, exit from the loop
3689 by forcing a failure after pushing on the stack the
3690 on_failure_jump's jump in the pattern, and d. */
3691 if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
3692 && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
3694 /* If this group ever matched anything, then restore
3695 what its registers were before trying this last
3696 failed match, e.g., with `(a*)*b' against `ab' for
3697 regstart[1], and, e.g., with `((a*)*(b*)*)*'
3698 against `aba' for regend[3].
3700 Also restore the registers for inner groups for,
3701 e.g., `((a*)(b*))*' against `aba' (register 3 would
3702 otherwise get trashed). */
3704 if (EVER_MATCHED_SOMETHING (reg_info[*p]))
3708 EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
3710 /* Restore this and inner groups' (if any) registers. */
3711 for (r = *p; r < *p + *(p + 1); r++)
3713 regstart[r] = old_regstart[r];
3715 /* xx why this test? */
3716 if ((int) old_regend[r] >= (int) regstart[r])
3717 regend[r] = old_regend[r];
3721 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
3722 PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
3728 /* Move past the register number and the inner group count. */
3733 /* \<digit> has been turned into a `duplicate' command which is
3734 followed by the numeric value of <digit> as the register number. */
3737 register const char *d2, *dend2;
3738 int regno = *p++; /* Get which register to match against. */
3739 DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
3741 /* Can't back reference a group which we've never matched. */
3742 if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
3745 /* Where in input to try to start matching. */
3746 d2 = regstart[regno];
3748 /* Where to stop matching; if both the place to start and
3749 the place to stop matching are in the same string, then
3750 set to the place to stop, otherwise, for now have to use
3751 the end of the first string. */
3753 dend2 = ((FIRST_STRING_P (regstart[regno])
3754 == FIRST_STRING_P (regend[regno]))
3755 ? regend[regno] : end_match_1);
3758 /* If necessary, advance to next segment in register
3762 if (dend2 == end_match_2) break;
3763 if (dend2 == regend[regno]) break;
3765 /* End of string1 => advance to string2. */
3767 dend2 = regend[regno];
3769 /* At end of register contents => success */
3770 if (d2 == dend2) break;
3772 /* If necessary, advance to next segment in data. */
3775 /* How many characters left in this segment to match. */
3778 /* Want how many consecutive characters we can match in
3779 one shot, so, if necessary, adjust the count. */
3780 if (mcnt > dend2 - d2)
3783 /* Compare that many; failure if mismatch, else move
3786 ? bcmp_translate (d, d2, mcnt, translate)
3787 : bcmp (d, d2, mcnt))
3789 d += mcnt, d2 += mcnt;
3795 /* begline matches the empty string at the beginning of the string
3796 (unless `not_bol' is set in `bufp'), and, if
3797 `newline_anchor' is set, after newlines. */
3799 DEBUG_PRINT1 ("EXECUTING begline.\n");
3801 if (AT_STRINGS_BEG ())
3803 if (!bufp->not_bol) break;
3805 else if (d[-1] == '\n' && bufp->newline_anchor)
3809 /* In all other cases, we fail. */
3813 /* endline is the dual of begline. */
3815 DEBUG_PRINT1 ("EXECUTING endline.\n");
3817 if (AT_STRINGS_END ())
3819 if (!bufp->not_eol) break;
3822 /* We have to ``prefetch'' the next character. */
3823 else if ((d == end1 ? *string2 : *d) == '\n'
3824 && bufp->newline_anchor)
3831 /* Match at the very beginning of the data. */
3833 DEBUG_PRINT1 ("EXECUTING begbuf.\n");
3834 if (AT_STRINGS_BEG ())
3839 /* Match at the very end of the data. */
3841 DEBUG_PRINT1 ("EXECUTING endbuf.\n");
3842 if (AT_STRINGS_END ())
3847 /* on_failure_keep_string_jump is used to optimize `.*\n'. It
3848 pushes NULL as the value for the string on the stack. Then
3849 `pop_failure_point' will keep the current value for the
3850 string, instead of restoring it. To see why, consider
3851 matching `foo\nbar' against `.*\n'. The .* matches the foo;
3852 then the . fails against the \n. But the next thing we want
3853 to do is match the \n against the \n; if we restored the
3854 string value, we would be back at the foo.
3856 Because this is used only in specific cases, we don't need to
3857 check all the things that `on_failure_jump' does, to make
3858 sure the right things get saved on the stack. Hence we don't
3859 share its code. The only reason to push anything on the
3860 stack at all is that otherwise we would have to change
3861 `anychar's code to do something besides goto fail in this
3862 case; that seems worse than this. */
3863 case on_failure_keep_string_jump:
3864 DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
3866 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3867 DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
3869 PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
3873 /* Uses of on_failure_jump:
3875 Each alternative starts with an on_failure_jump that points
3876 to the beginning of the next alternative. Each alternative
3877 except the last ends with a jump that in effect jumps past
3878 the rest of the alternatives. (They really jump to the
3879 ending jump of the following alternative, because tensioning
3880 these jumps is a hassle.)
3882 Repeats start with an on_failure_jump that points past both
3883 the repetition text and either the following jump or
3884 pop_failure_jump back to this on_failure_jump. */
3885 case on_failure_jump:
3887 DEBUG_PRINT1 ("EXECUTING on_failure_jump");
3889 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3890 DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
3892 /* If this on_failure_jump comes right before a group (i.e.,
3893 the original * applied to a group), save the information
3894 for that group and all inner ones, so that if we fail back
3895 to this point, the group's information will be correct.
3896 For example, in \(a*\)*\1, we only need the preceding group,
3897 and in \(\(a*\)b*\)\2, we need the inner group. */
3899 /* We can't use `p' to check ahead because we push
3900 a failure point to `p + mcnt' after we do this. */
3903 /* We need to skip no_op's before we look for the
3904 start_memory in case this on_failure_jump is happening as
3905 the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
3907 while (p1 < pend && (re_opcode_t) *p1 == no_op)
3910 if (p1 < pend && (re_opcode_t) *p1 == start_memory)
3912 /* We have a new highest active register now. This will
3913 get reset at the start_memory we are about to get to,
3914 but we will have saved all the registers relevant to
3915 this repetition op, as described above. */
3916 highest_active_reg = *(p1 + 1) + *(p1 + 2);
3917 if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
3918 lowest_active_reg = *(p1 + 1);
3921 DEBUG_PRINT1 (":\n");
3922 PUSH_FAILURE_POINT (p + mcnt, d, -2);
3926 /* A smart repeat ends with a maybe_pop_jump.
3927 We change it either to a pop_failure_jump or a jump. */
3928 case maybe_pop_jump:
3929 EXTRACT_NUMBER_AND_INCR (mcnt, p);
3930 DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
3932 register unsigned char *p2 = p;
3934 /* Compare the beginning of the repeat with what in the
3935 pattern follows its end. If we can establish that there
3936 is nothing that they would both match, i.e., that we
3937 would have to backtrack because of (as in, e.g., `a*a')
3938 then we can change to pop_failure_jump, because we'll
3939 never have to backtrack.
3941 This is not true in the case of alternatives: in
3942 `(a|ab)*' we do need to backtrack to the `ab' alternative
3943 (e.g., if the string was `ab'). But instead of trying to
3944 detect that here, the alternative has put on a dummy
3945 failure point which is what we will end up popping. */
3947 /* Skip over open/close-group commands. */
3948 while (p2 + 2 < pend
3949 && ((re_opcode_t) *p2 == stop_memory
3950 || (re_opcode_t) *p2 == start_memory))
3951 p2 += 3; /* Skip over args, too. */
3953 /* If we're at the end of the pattern, we can change. */
3956 p[-3] = (unsigned char) pop_failure_jump;
3958 (" End of pattern: change to `pop_failure_jump'.\n");
3961 else if ((re_opcode_t) *p2 == exactn
3962 || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
3964 register unsigned char c
3965 = *p2 == (unsigned char) endline ? '\n' : p2[2];
3968 /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
3969 to the `maybe_finalize_jump' of this case. Examine what
3971 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
3972 p[-3] = (unsigned char) pop_failure_jump;
3973 else if ((re_opcode_t) p1[3] == charset
3974 || (re_opcode_t) p1[3] == charset_not)
3976 int not = (re_opcode_t) p1[3] == charset_not;
3978 if (c < (unsigned char) (p1[4] * BYTEWIDTH)
3979 && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
3982 /* `not' is equal to 1 if c would match, which means
3983 that we can't change to pop_failure_jump. */
3986 p[-3] = (unsigned char) pop_failure_jump;
3988 (" No match: change to `pop_failure_jump'.\n");
3994 p -= 2; /* Point at relative address again. */
3995 if ((re_opcode_t) p[-1] != pop_failure_jump)
3997 p[-1] = (unsigned char) jump;
3998 goto unconditional_jump;
4000 /* Note fall through. */
4003 /* The end of a simple repeat has a pop_failure_jump back to
4004 its matching on_failure_jump, where the latter will push a
4005 failure point. The pop_failure_jump takes off failure
4006 points put on by this pop_failure_jump's matching
4007 on_failure_jump; we got through the pattern to here from the
4008 matching on_failure_jump, so didn't fail. */
4009 case pop_failure_jump:
4011 /* We need to pass separate storage for the lowest and
4012 highest registers, even though we don't care about the
4013 actual values. Otherwise, we will restore only one
4014 register from the stack, since lowest will == highest in
4015 `pop_failure_point'. */
4016 unsigned dummy_low_reg, dummy_high_reg;
4017 unsigned char *pdummy;
4020 DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
4021 POP_FAILURE_POINT (sdummy, pdummy,
4022 dummy_low_reg, dummy_high_reg,
4023 reg_dummy, reg_dummy, reg_info_dummy);
4025 /* Note fall through. */
4028 /* Unconditionally jump (without popping any failure points). */
4031 EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */
4032 DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
4033 p += mcnt; /* Do the jump. */
4034 DEBUG_PRINT2 ("(to 0x%x).\n", p);
4038 /* We need this opcode so we can detect where alternatives end
4039 in `group_match_null_string_p' et al. */
4041 DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
4042 goto unconditional_jump;
4045 /* Normally, the on_failure_jump pushes a failure point, which
4046 then gets popped at pop_failure_jump. We will end up at
4047 pop_failure_jump, also, and with a pattern of, say, `a+', we
4048 are skipping over the on_failure_jump, so we have to push
4049 something meaningless for pop_failure_jump to pop. */
4050 case dummy_failure_jump:
4051 DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
4052 /* It doesn't matter what we push for the string here. What
4053 the code at `fail' tests is the value for the pattern. */
4054 PUSH_FAILURE_POINT (0, 0, -2);
4055 goto unconditional_jump;
4058 /* At the end of an alternative, we need to push a dummy failure
4059 point in case we are followed by a pop_failure_jump', because
4060 we don't want the failure point for the alternative to be
4061 popped. For example, matching `(a|ab)*' against `aab'
4062 requires that we match the `ab' alternative. */
4063 case push_dummy_failure:
4064 DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
4065 /* See comments just above at `dummy_failure_jump' about the
4067 PUSH_FAILURE_POINT (0, 0, -2);
4070 /* Have to succeed matching what follows at least n times.
4071 After that, handle like `on_failure_jump'. */
4073 EXTRACT_NUMBER (mcnt, p + 2);
4074 DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
4077 /* Originally, this is how many times we HAVE to succeed. */
4082 STORE_NUMBER_AND_INCR (p, mcnt);
4083 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt);
4087 DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2);
4088 p[2] = (unsigned char) no_op;
4089 p[3] = (unsigned char) no_op;
4095 EXTRACT_NUMBER (mcnt, p + 2);
4096 DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
4098 /* Originally, this is how many times we CAN jump. */
4102 STORE_NUMBER (p + 2, mcnt);
4103 goto unconditional_jump;
4105 /* If don't have to jump any more, skip over the rest of command. */
4112 DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
4114 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4116 EXTRACT_NUMBER_AND_INCR (mcnt, p);
4117 DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt);
4118 STORE_NUMBER (p1, mcnt);
4123 DEBUG_PRINT1 ("EXECUTING wordbound.\n");
4124 if (AT_WORD_BOUNDARY (d))
4129 DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
4130 if (AT_WORD_BOUNDARY (d))
4135 DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
4136 if (LETTER_P (d) && (AT_STRINGS_BEG () || !LETTER_P (d - 1)))
4141 DEBUG_PRINT1 ("EXECUTING wordend.\n");
4142 if (!AT_STRINGS_BEG () && LETTER_P (d - 1)
4143 && (!LETTER_P (d) || AT_STRINGS_END ()))
4150 DEBUG_PRINT1 ("EXECUTING before_dot.\n");
4151 if (PTR_CHAR_POS ((unsigned char *) d) >= point)
4156 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4157 if (PTR_CHAR_POS ((unsigned char *) d) != point)
4162 DEBUG_PRINT1 ("EXECUTING after_dot.\n");
4163 if (PTR_CHAR_POS ((unsigned char *) d) <= point)
4166 #else /* not emacs19 */
4168 DEBUG_PRINT1 ("EXECUTING at_dot.\n");
4169 if (PTR_CHAR_POS ((unsigned char *) d) + 1 != point)
4172 #endif /* not emacs19 */
4175 DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
4180 DEBUG_PRINT1 ("EXECUTING wordchar.\n");
4184 if (SYNTAX (*d++) != (enum syntaxcode) mcnt) goto fail;
4185 SET_REGS_MATCHED ();
4189 DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
4191 goto matchnotsyntax;
4194 DEBUG_PRINT1 ("EXECUTING notwordchar.\n");
4196 matchnotsyntax: /* We goto here from notsyntaxspec. */
4198 if (SYNTAX (*d++) == (enum syntaxcode) mcnt) goto fail;
4199 SET_REGS_MATCHED ();
4202 #else /* not emacs */
4204 DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
4208 SET_REGS_MATCHED ();
4212 DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
4216 SET_REGS_MATCHED ();
4218 #endif /* not emacs */
4223 continue; /* Successfully executed one pattern command; keep going. */
4226 /* We goto here if a matching operation fails. */
4228 if (!FAIL_STACK_EMPTY ())
4229 { /* A restart point is known. Restore to that state. */
4230 DEBUG_PRINT1 ("\nFAIL:\n");
4231 POP_FAILURE_POINT (d, p,
4232 lowest_active_reg, highest_active_reg,
4233 regstart, regend, reg_info);
4235 /* If this failure point is a dummy, try the next one. */
4239 /* If we failed to the end of the pattern, don't examine *p. */
4243 boolean is_a_jump_n = false;
4245 /* If failed to a backwards jump that's part of a repetition
4246 loop, need to pop this failure point and use the next one. */
4247 switch ((re_opcode_t) *p)
4251 case maybe_pop_jump:
4252 case pop_failure_jump:
4255 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4258 if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
4260 && (re_opcode_t) *p1 == on_failure_jump))
4268 if (d >= string1 && d <= end1)
4272 break; /* Matching at this starting point really fails. */
4276 goto restore_best_regs;
4280 return -1; /* Failure to match. */
4283 /* Subroutine definitions for re_match_2. */
4286 /* We are passed P pointing to a register number after a start_memory.
4288 Return true if the pattern up to the corresponding stop_memory can
4289 match the empty string, and false otherwise.
4291 If we find the matching stop_memory, sets P to point to one past its number.
4292 Otherwise, sets P to an undefined byte less than or equal to END.
4294 We don't handle duplicates properly (yet). */
4297 group_match_null_string_p (p, end, reg_info)
4298 unsigned char **p, *end;
4299 register_info_type *reg_info;
4302 /* Point to after the args to the start_memory. */
4303 unsigned char *p1 = *p + 2;
4307 /* Skip over opcodes that can match nothing, and return true or
4308 false, as appropriate, when we get to one that can't, or to the
4309 matching stop_memory. */
4311 switch ((re_opcode_t) *p1)
4313 /* Could be either a loop or a series of alternatives. */
4314 case on_failure_jump:
4316 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4318 /* If the next operation is not a jump backwards in the
4323 /* Go through the on_failure_jumps of the alternatives,
4324 seeing if any of the alternatives cannot match nothing.
4325 The last alternative starts with only a jump,
4326 whereas the rest start with on_failure_jump and end
4327 with a jump, e.g., here is the pattern for `a|b|c':
4329 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
4330 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
4333 So, we have to first go through the first (n-1)
4334 alternatives and then deal with the last one separately. */
4337 /* Deal with the first (n-1) alternatives, which start
4338 with an on_failure_jump (see above) that jumps to right
4339 past a jump_past_alt. */
4341 while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
4343 /* `mcnt' holds how many bytes long the alternative
4344 is, including the ending `jump_past_alt' and
4347 if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
4351 /* Move to right after this alternative, including the
4355 /* Break if it's the beginning of an n-th alternative
4356 that doesn't begin with an on_failure_jump. */
4357 if ((re_opcode_t) *p1 != on_failure_jump)
4360 /* Still have to check that it's not an n-th
4361 alternative that starts with an on_failure_jump. */
4363 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4364 if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
4366 /* Get to the beginning of the n-th alternative. */
4372 /* Deal with the last alternative: go back and get number
4373 of the `jump_past_alt' just before it. `mcnt' contains
4374 the length of the alternative. */
4375 EXTRACT_NUMBER (mcnt, p1 - 2);
4377 if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
4380 p1 += mcnt; /* Get past the n-th alternative. */
4386 assert (p1[1] == **p);
4392 if (!common_op_match_null_string_p (&p1, end, reg_info))
4395 } /* while p1 < end */
4398 } /* group_match_null_string_p */
4401 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
4402 It expects P to be the first byte of a single alternative and END one
4403 byte past the last. The alternative can contain groups. */
4406 alt_match_null_string_p (p, end, reg_info)
4407 unsigned char *p, *end;
4408 register_info_type *reg_info;
4411 unsigned char *p1 = p;
4415 /* Skip over opcodes that can match nothing, and break when we get
4416 to one that can't. */
4418 switch ((re_opcode_t) *p1)
4421 case on_failure_jump:
4423 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4428 if (!common_op_match_null_string_p (&p1, end, reg_info))
4431 } /* while p1 < end */
4434 } /* alt_match_null_string_p */
4437 /* Deals with the ops common to group_match_null_string_p and
4438 alt_match_null_string_p.
4440 Sets P to one after the op and its arguments, if any. */
4443 common_op_match_null_string_p (p, end, reg_info)
4444 unsigned char **p, *end;
4445 register_info_type *reg_info;
4450 unsigned char *p1 = *p;
4452 switch ((re_opcode_t) *p1++)
4472 assert (reg_no > 0 && reg_no <= MAX_REGNUM);
4473 ret = group_match_null_string_p (&p1, end, reg_info);
4475 /* Have to set this here in case we're checking a group which
4476 contains a group and a back reference to it. */
4478 if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
4479 REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
4485 /* If this is an optimized succeed_n for zero times, make the jump. */
4487 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4495 /* Get to the number of times to succeed. */
4497 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4502 EXTRACT_NUMBER_AND_INCR (mcnt, p1);
4510 if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
4518 /* All other opcodes mean we cannot match the empty string. */
4524 } /* common_op_match_null_string_p */
4527 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
4528 bytes; nonzero otherwise. */
4531 bcmp_translate (s1, s2, len, translate)
4532 unsigned char *s1, *s2;
4536 register unsigned char *p1 = s1, *p2 = s2;
4539 if (translate[*p1++] != translate[*p2++]) return 1;
4545 /* Entry points for GNU code. */
4547 /* re_compile_pattern is the GNU regular expression compiler: it
4548 compiles PATTERN (of length SIZE) and puts the result in BUFP.
4549 Returns 0 if the pattern was valid, otherwise an error string.
4551 Assumes the `allocated' (and perhaps `buffer') and `translate' fields
4552 are set in BUFP on entry.
4554 We call regex_compile to do the actual compilation. */
4557 re_compile_pattern (pattern, length, bufp)
4558 const char *pattern;
4560 struct re_pattern_buffer *bufp;
4564 /* GNU code is written to assume at least RE_NREGS registers will be set
4565 (and at least one extra will be -1). */
4566 bufp->regs_allocated = REGS_UNALLOCATED;
4568 /* And GNU code determines whether or not to get register information
4569 by passing null for the REGS argument to re_match, etc., not by
4573 /* Match anchors at newline. */
4574 bufp->newline_anchor = 1;
4576 ret = regex_compile (pattern, length, re_syntax_options, bufp);
4578 return re_error_msg[(int) ret];
4581 /* Entry points compatible with 4.2 BSD regex library. We don't define
4582 them if this is an Emacs or POSIX compilation. */
4584 #if !defined (emacs) && !defined (_POSIX_SOURCE)
4586 /* BSD has one and only one pattern buffer. */
4587 static struct re_pattern_buffer re_comp_buf;
4597 if (!re_comp_buf.buffer)
4598 return "No previous regular expression";
4602 if (!re_comp_buf.buffer)
4604 re_comp_buf.buffer = (unsigned char *) malloc (200);
4605 if (re_comp_buf.buffer == NULL)
4606 return "Memory exhausted";
4607 re_comp_buf.allocated = 200;
4609 re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
4610 if (re_comp_buf.fastmap == NULL)
4611 return "Memory exhausted";
4614 /* Since `re_exec' always passes NULL for the `regs' argument, we
4615 don't need to initialize the pattern buffer fields which affect it. */
4617 /* Match anchors at newlines. */
4618 re_comp_buf.newline_anchor = 1;
4620 ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
4622 /* Yes, we're discarding `const' here. */
4623 return (char *) re_error_msg[(int) ret];
4631 const int len = strlen (s);
4633 0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
4635 #endif /* not emacs and not _POSIX_SOURCE */
4637 /* POSIX.2 functions. Don't define these for Emacs. */
4641 /* regcomp takes a regular expression as a string and compiles it.
4643 PREG is a regex_t *. We do not expect any fields to be initialized,
4644 since POSIX says we shouldn't. Thus, we set
4646 `buffer' to the compiled pattern;
4647 `used' to the length of the compiled pattern;
4648 `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
4649 REG_EXTENDED bit in CFLAGS is set; otherwise, to
4650 RE_SYNTAX_POSIX_BASIC;
4651 `newline_anchor' to REG_NEWLINE being set in CFLAGS;
4652 `fastmap' and `fastmap_accurate' to zero;
4653 `re_nsub' to the number of subexpressions in PATTERN.
4655 PATTERN is the address of the pattern string.
4657 CFLAGS is a series of bits which affect compilation.
4659 If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
4660 use POSIX basic syntax.
4662 If REG_NEWLINE is set, then . and [^...] don't match newline.
4663 Also, regexec will try a match beginning after every newline.
4665 If REG_ICASE is set, then we considers upper- and lowercase
4666 versions of letters to be equivalent when matching.
4668 If REG_NOSUB is set, then when PREG is passed to regexec, that
4669 routine will report only success or failure, and nothing about the
4672 It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for
4673 the return codes and their meanings.) */
4676 regcomp (preg, pattern, cflags)
4678 const char *pattern;
4683 = cflags & REG_EXTENDED ? RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
4685 /* regex_compile will allocate the space for the compiled pattern. */
4688 /* Don't bother to use a fastmap when searching. This simplifies the
4689 REG_NEWLINE case: if we used a fastmap, we'd have to put all the
4690 characters after newlines into the fastmap. This way, we just try
4694 if (cflags & REG_ICASE)
4698 preg->translate = (char *) malloc (CHAR_SET_SIZE);
4699 if (preg->translate == NULL)
4700 return (int) REG_ESPACE;
4702 /* Map uppercase characters to corresponding lowercase ones. */
4703 for (i = 0; i < CHAR_SET_SIZE; i++)
4704 preg->translate[i] = isupper (i) ? tolower (i) : i;
4707 preg->translate = NULL;
4709 /* If REG_NEWLINE is set, newlines are treated differently. */
4710 if (cflags & REG_NEWLINE)
4711 { /* REG_NEWLINE implies neither . nor [^...] match newline. */
4712 syntax &= ~RE_DOT_NEWLINE;
4713 syntax |= RE_HAT_LISTS_NOT_NEWLINE;
4714 /* It also changes the matching behavior. */
4715 preg->newline_anchor = 1;
4718 preg->newline_anchor = 0;
4720 preg->no_sub = !!(cflags & REG_NOSUB);
4722 /* POSIX says a null character in the pattern terminates it, so we
4723 can use strlen here in compiling the pattern. */
4724 ret = regex_compile (pattern, strlen (pattern), syntax, preg);
4726 /* POSIX doesn't distinguish between an unmatched open-group and an
4727 unmatched close-group: both are REG_EPAREN. */
4728 if (ret == REG_ERPAREN) ret = REG_EPAREN;
4734 /* regexec searches for a given pattern, specified by PREG, in the
4737 If NMATCH is zero or REG_NOSUB was set in the cflags argument to
4738 `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at
4739 least NMATCH elements, and we set them to the offsets of the
4740 corresponding matched substrings.
4742 EFLAGS specifies `execution flags' which affect matching: if
4743 REG_NOTBOL is set, then ^ does not match at the beginning of the
4744 string; if REG_NOTEOL is set, then $ does not match at the end.
4746 We return 0 if we find a match and REG_NOMATCH if not. */
4749 regexec (preg, string, nmatch, pmatch, eflags)
4750 const regex_t *preg;
4753 regmatch_t pmatch[];
4757 struct re_registers regs;
4758 regex_t private_preg;
4759 int len = strlen (string);
4760 boolean want_reg_info = !preg->no_sub && nmatch > 0;
4762 private_preg = *preg;
4764 private_preg.not_bol = !!(eflags & REG_NOTBOL);
4765 private_preg.not_eol = !!(eflags & REG_NOTEOL);
4767 /* The user has told us exactly how many registers to return
4768 information about, via `nmatch'. We have to pass that on to the
4769 matching routines. */
4770 private_preg.regs_allocated = REGS_FIXED;
4774 regs.num_regs = nmatch;
4775 regs.start = TALLOC (nmatch, regoff_t);
4776 regs.end = TALLOC (nmatch, regoff_t);
4777 if (regs.start == NULL || regs.end == NULL)
4778 return (int) REG_NOMATCH;
4781 /* Perform the searching operation. */
4782 ret = re_search (&private_preg, string, len,
4783 /* start: */ 0, /* range: */ len,
4784 want_reg_info ? ®s : (struct re_registers *) 0);
4786 /* Copy the register information to the POSIX structure. */
4793 for (r = 0; r < nmatch; r++)
4795 pmatch[r].rm_so = regs.start[r];
4796 pmatch[r].rm_eo = regs.end[r];
4800 /* If we needed the temporary register info, free the space now. */
4805 /* We want zero return to mean success, unlike `re_search'. */
4806 return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
4810 /* Returns a message corresponding to an error code, ERRCODE, returned
4811 from either regcomp or regexec. */
4814 regerror (errcode, preg, errbuf, errbuf_size)
4816 const regex_t *preg;
4821 = re_error_msg[errcode] == NULL ? "Success" : re_error_msg[errcode];
4822 size_t msg_size = strlen (msg) + 1; /* Includes the null. */
4824 if (errbuf_size != 0)
4826 if (msg_size > errbuf_size)
4828 strncpy (errbuf, msg, errbuf_size - 1);
4829 errbuf[errbuf_size - 1] = 0;
4832 strcpy (errbuf, msg);
4839 /* Free dynamically allocated space used by PREG. */
4845 if (preg->buffer != NULL)
4846 free (preg->buffer);
4847 preg->buffer = NULL;
4849 preg->allocated = 0;
4852 if (preg->fastmap != NULL)
4853 free (preg->fastmap);
4854 preg->fastmap = NULL;
4855 preg->fastmap_accurate = 0;
4857 if (preg->translate != NULL)
4858 free (preg->translate);
4859 preg->translate = NULL;
4862 #endif /* not emacs */
4866 make-backup-files: t
4868 trim-versions-without-asking: nil