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       ---
       regex.c (184553B)
       ---
            1 /* Extended regular expression matching and search library,
            2    version 0.12.
            3    (Implements POSIX draft P1003.2/D11.2, except for some of the
            4    internationalization features.)
            5 
            6    Copyright (C) 1993-1998 Free Software Foundation, Inc.
            7 
            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)
           11    any later version.
           12 
           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.
           17 
           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 Foundation,
           20    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
           21 
           22 /* AIX requires this to be the first thing in the file. */
           23 #if defined (_AIX) && !defined (REGEX_MALLOC)
           24   #pragma alloca
           25 #endif
           26 
           27 #undef        _GNU_SOURCE
           28 #define _GNU_SOURCE
           29 
           30 #ifdef HAVE_CONFIG_H
           31 #include <config.h>
           32 #endif
           33 
           34 #if defined(STDC_HEADERS) && !defined(emacs)
           35 #include <stddef.h>
           36 #else
           37 /* We need this for `regex.h', and perhaps for the Emacs include files.  */
           38 #include <sys/types.h>
           39 #endif
           40 
           41 /* For platform which support the ISO C amendement 1 functionality we
           42    support user defined character classes.  */
           43 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
           44 # include <wctype.h>
           45 # include <wchar.h>
           46 #endif
           47 
           48 /* This is for other GNU distributions with internationalized messages.  */
           49 #if HAVE_LIBINTL_H || defined (_LIBC)
           50 # include <libintl.h>
           51 #else
           52 # define gettext(msgid) (msgid)
           53 #endif
           54 
           55 #ifndef gettext_noop
           56 /* This define is so xgettext can find the internationalizable
           57    strings.  */
           58 #define gettext_noop(String) String
           59 #endif
           60 
           61 /* The `emacs' switch turns on certain matching commands
           62    that make sense only in Emacs. */
           63 #ifdef emacs
           64 
           65 #include "lisp.h"
           66 #include "buffer.h"
           67 #include "syntax.h"
           68 
           69 #else  /* not emacs */
           70 
           71 /* If we are not linking with Emacs proper,
           72    we can't use the relocating allocator
           73    even if config.h says that we can.  */
           74 #undef REL_ALLOC
           75 
           76 #if defined (STDC_HEADERS) || defined (_LIBC)
           77 #include <stdlib.h>
           78 #else
           79 char *malloc ();
           80 char *realloc ();
           81 #endif
           82 
           83 /* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
           84    If nothing else has been done, use the method below.  */
           85 #ifdef INHIBIT_STRING_HEADER
           86 #if !(defined (HAVE_BZERO) && defined (HAVE_BCOPY))
           87 #if !defined (bzero) && !defined (bcopy)
           88 #undef INHIBIT_STRING_HEADER
           89 #endif
           90 #endif
           91 #endif
           92 
           93 /* This is the normal way of making sure we have a bcopy and a bzero.
           94    This is used in most programs--a few other programs avoid this
           95    by defining INHIBIT_STRING_HEADER.  */
           96 #ifndef INHIBIT_STRING_HEADER
           97 #if defined (HAVE_STRING_H) || defined (STDC_HEADERS) || defined (_LIBC)
           98 #include <string.h>
           99 #ifndef bcmp
          100 #define bcmp(s1, s2, n)        memcmp ((s1), (s2), (n))
          101 #endif
          102 #ifndef bcopy
          103 #define bcopy(s, d, n)        memcpy ((d), (s), (n))
          104 #endif
          105 #ifndef bzero
          106 #define bzero(s, n)        memset ((s), 0, (n))
          107 #endif
          108 #else
          109 #include <strings.h>
          110 #endif
          111 #endif
          112 
          113 /* Define the syntax stuff for \<, \>, etc.  */
          114 
          115 /* This must be nonzero for the wordchar and notwordchar pattern
          116    commands in re_match_2.  */
          117 #ifndef Sword
          118 #define Sword 1
          119 #endif
          120 
          121 #ifdef SWITCH_ENUM_BUG
          122 #define SWITCH_ENUM_CAST(x) ((int)(x))
          123 #else
          124 #define SWITCH_ENUM_CAST(x) (x)
          125 #endif
          126 
          127 #ifdef SYNTAX_TABLE
          128 
          129 extern char *re_syntax_table;
          130 
          131 #else /* not SYNTAX_TABLE */
          132 
          133 /* How many characters in the character set.  */
          134 #define CHAR_SET_SIZE 256
          135 
          136 static char re_syntax_table[CHAR_SET_SIZE];
          137 
          138 static void
          139 init_syntax_once ()
          140 {
          141    register int c;
          142    static int done = 0;
          143 
          144    if (done)
          145      return;
          146 
          147    bzero (re_syntax_table, sizeof re_syntax_table);
          148 
          149    for (c = 'a'; c <= 'z'; c++)
          150      re_syntax_table[c] = Sword;
          151 
          152    for (c = 'A'; c <= 'Z'; c++)
          153      re_syntax_table[c] = Sword;
          154 
          155    for (c = '0'; c <= '9'; c++)
          156      re_syntax_table[c] = Sword;
          157 
          158    re_syntax_table['_'] = Sword;
          159 
          160    done = 1;
          161 }
          162 
          163 #endif /* not SYNTAX_TABLE */
          164 
          165 #define SYNTAX(c) re_syntax_table[c]
          166 
          167 #endif /* not emacs */
          168 
          169 /* Get the interface, including the syntax bits.  */
          170 #include "regex.h"
          171 
          172 /* isalpha etc. are used for the character classes.  */
          173 #include <ctype.h>
          174 
          175 /* Jim Meyering writes:
          176 
          177    "... Some ctype macros are valid only for character codes that
          178    isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
          179    using /bin/cc or gcc but without giving an ansi option).  So, all
          180    ctype uses should be through macros like ISPRINT...  If
          181    STDC_HEADERS is defined, then autoconf has verified that the ctype
          182    macros don't need to be guarded with references to isascii. ...
          183    Defining isascii to 1 should let any compiler worth its salt
          184    eliminate the && through constant folding."  */
          185 
          186 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
          187 #define ISASCII(c) 1
          188 #else
          189 #define ISASCII(c) isascii(c)
          190 #endif
          191 
          192 #ifdef isblank
          193 #define ISBLANK(c) (ISASCII (c) && isblank (c))
          194 #else
          195 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
          196 #endif
          197 #ifdef isgraph
          198 #define ISGRAPH(c) (ISASCII (c) && isgraph (c))
          199 #else
          200 #define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
          201 #endif
          202 
          203 #define ISPRINT(c) (ISASCII (c) && isprint (c))
          204 #define ISDIGIT(c) (ISASCII (c) && isdigit (c))
          205 #define ISALNUM(c) (ISASCII (c) && isalnum (c))
          206 #define ISALPHA(c) (ISASCII (c) && isalpha (c))
          207 #define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
          208 #define ISLOWER(c) (ISASCII (c) && islower (c))
          209 #define ISPUNCT(c) (ISASCII (c) && ispunct (c))
          210 #define ISSPACE(c) (ISASCII (c) && isspace (c))
          211 #define ISUPPER(c) (ISASCII (c) && isupper (c))
          212 #define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
          213 
          214 #ifndef NULL
          215 #define NULL (void *)0
          216 #endif
          217 
          218 /* We remove any previous definition of `SIGN_EXTEND_CHAR',
          219    since ours (we hope) works properly with all combinations of
          220    machines, compilers, `char' and `unsigned char' argument types.
          221    (Per Bothner suggested the basic approach.)  */
          222 #undef SIGN_EXTEND_CHAR
          223 #if __STDC__
          224 #define SIGN_EXTEND_CHAR(c) ((signed char) (c))
          225 #else  /* not __STDC__ */
          226 /* As in Harbison and Steele.  */
          227 #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
          228 #endif
          229 
          230 /* Should we use malloc or alloca?  If REGEX_MALLOC is not defined, we
          231    use `alloca' instead of `malloc'.  This is because using malloc in
          232    re_search* or re_match* could cause memory leaks when C-g is used in
          233    Emacs; also, malloc is slower and causes storage fragmentation.  On
          234    the other hand, malloc is more portable, and easier to debug.
          235 
          236    Because we sometimes use alloca, some routines have to be macros,
          237    not functions -- `alloca'-allocated space disappears at the end of the
          238    function it is called in.  */
          239 
          240 #ifdef REGEX_MALLOC
          241 
          242 #define REGEX_ALLOCATE malloc
          243 #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
          244 #define REGEX_FREE free
          245 
          246 #else /* not REGEX_MALLOC  */
          247 
          248 /* Emacs already defines alloca, sometimes.  */
          249 #ifndef alloca
          250 
          251 /* Make alloca work the best possible way.  */
          252 #ifdef __GNUC__
          253 #define alloca __builtin_alloca
          254 #else /* not __GNUC__ */
          255 #if HAVE_ALLOCA_H
          256 #include <alloca.h>
          257 #else /* not __GNUC__ or HAVE_ALLOCA_H */
          258 #if 0 /* It is a bad idea to declare alloca.  We always cast the result.  */
          259 #ifndef _AIX /* Already did AIX, up at the top.  */
          260 char *alloca ();
          261 #endif /* not _AIX */
          262 #endif
          263 #endif /* not HAVE_ALLOCA_H */
          264 #endif /* not __GNUC__ */
          265 
          266 #endif /* not alloca */
          267 
          268 #define REGEX_ALLOCATE alloca
          269 
          270 /* Assumes a `char *destination' variable.  */
          271 #define REGEX_REALLOCATE(source, osize, nsize)                                \
          272   (destination = (char *) alloca (nsize),                                \
          273    bcopy (source, destination, osize),                                        \
          274    destination)
          275 
          276 /* No need to do anything to free, after alloca.  */
          277 #define REGEX_FREE(arg) ((void)0) /* Do nothing!  But inhibit gcc warning.  */
          278 
          279 #endif /* not REGEX_MALLOC */
          280 
          281 /* Define how to allocate the failure stack.  */
          282 
          283 #if defined (REL_ALLOC) && defined (REGEX_MALLOC)
          284 
          285 #define REGEX_ALLOCATE_STACK(size)                                \
          286   r_alloc (&failure_stack_ptr, (size))
          287 #define REGEX_REALLOCATE_STACK(source, osize, nsize)                \
          288   r_re_alloc (&failure_stack_ptr, (nsize))
          289 #define REGEX_FREE_STACK(ptr)                                        \
          290   r_alloc_free (&failure_stack_ptr)
          291 
          292 #else /* not using relocating allocator */
          293 
          294 #ifdef REGEX_MALLOC
          295 
          296 #define REGEX_ALLOCATE_STACK malloc
          297 #define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
          298 #define REGEX_FREE_STACK free
          299 
          300 #else /* not REGEX_MALLOC */
          301 
          302 #define REGEX_ALLOCATE_STACK alloca
          303 
          304 #define REGEX_REALLOCATE_STACK(source, osize, nsize)                        \
          305    REGEX_REALLOCATE (source, osize, nsize)
          306 /* No need to explicitly free anything.  */
          307 #define REGEX_FREE_STACK(arg)
          308 
          309 #endif /* not REGEX_MALLOC */
          310 #endif /* not using relocating allocator */
          311 
          312 
          313 /* True if `size1' is non-NULL and PTR is pointing anywhere inside
          314    `string1' or just past its end.  This works if PTR is NULL, which is
          315    a good thing.  */
          316 #define FIRST_STRING_P(ptr)                                         \
          317   (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
          318 
          319 /* (Re)Allocate N items of type T using malloc, or fail.  */
          320 #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
          321 #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
          322 #define RETALLOC_IF(addr, n, t) \
          323   if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
          324 #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
          325 
          326 #define BYTEWIDTH 8 /* In bits.  */
          327 
          328 #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
          329 
          330 #undef MAX
          331 #undef MIN
          332 #define MAX(a, b) ((a) > (b) ? (a) : (b))
          333 #define MIN(a, b) ((a) < (b) ? (a) : (b))
          334 
          335 typedef char boolean;
          336 #define false 0
          337 #define true 1
          338 
          339 static int re_match_2_internal ();
          340 
          341 /* These are the command codes that appear in compiled regular
          342    expressions.  Some opcodes are followed by argument bytes.  A
          343    command code can specify any interpretation whatsoever for its
          344    arguments.  Zero bytes may appear in the compiled regular expression.  */
          345 
          346 typedef enum
          347 {
          348   no_op = 0,
          349 
          350   /* Succeed right away--no more backtracking.  */
          351   succeed,
          352 
          353         /* Followed by one byte giving n, then by n literal bytes.  */
          354   exactn,
          355 
          356         /* Matches any (more or less) character.  */
          357   anychar,
          358 
          359         /* Matches any one char belonging to specified set.  First
          360            following byte is number of bitmap bytes.  Then come bytes
          361            for a bitmap saying which chars are in.  Bits in each byte
          362            are ordered low-bit-first.  A character is in the set if its
          363            bit is 1.  A character too large to have a bit in the map is
          364            automatically not in the set.  */
          365   charset,
          366 
          367         /* Same parameters as charset, but match any character that is
          368            not one of those specified.  */
          369   charset_not,
          370 
          371         /* Start remembering the text that is matched, for storing in a
          372            register.  Followed by one byte with the register number, in
          373            the range 0 to one less than the pattern buffer's re_nsub
          374            field.  Then followed by one byte with the number of groups
          375            inner to this one.  (This last has to be part of the
          376            start_memory only because we need it in the on_failure_jump
          377            of re_match_2.)  */
          378   start_memory,
          379 
          380         /* Stop remembering the text that is matched and store it in a
          381            memory register.  Followed by one byte with the register
          382            number, in the range 0 to one less than `re_nsub' in the
          383            pattern buffer, and one byte with the number of inner groups,
          384            just like `start_memory'.  (We need the number of inner
          385            groups here because we don't have any easy way of finding the
          386            corresponding start_memory when we're at a stop_memory.)  */
          387   stop_memory,
          388 
          389         /* Match a duplicate of something remembered. Followed by one
          390            byte containing the register number.  */
          391   duplicate,
          392 
          393         /* Fail unless at beginning of line.  */
          394   begline,
          395 
          396         /* Fail unless at end of line.  */
          397   endline,
          398 
          399         /* Succeeds if at beginning of buffer (if emacs) or at beginning
          400            of string to be matched (if not).  */
          401   begbuf,
          402 
          403         /* Analogously, for end of buffer/string.  */
          404   endbuf,
          405 
          406         /* Followed by two byte relative address to which to jump.  */
          407   jump,
          408 
          409         /* Same as jump, but marks the end of an alternative.  */
          410   jump_past_alt,
          411 
          412         /* Followed by two-byte relative address of place to resume at
          413            in case of failure.  */
          414   on_failure_jump,
          415 
          416         /* Like on_failure_jump, but pushes a placeholder instead of the
          417            current string position when executed.  */
          418   on_failure_keep_string_jump,
          419 
          420         /* Throw away latest failure point and then jump to following
          421            two-byte relative address.  */
          422   pop_failure_jump,
          423 
          424         /* Change to pop_failure_jump if know won't have to backtrack to
          425            match; otherwise change to jump.  This is used to jump
          426            back to the beginning of a repeat.  If what follows this jump
          427            clearly won't match what the repeat does, such that we can be
          428            sure that there is no use backtracking out of repetitions
          429            already matched, then we change it to a pop_failure_jump.
          430            Followed by two-byte address.  */
          431   maybe_pop_jump,
          432 
          433         /* Jump to following two-byte address, and push a dummy failure
          434            point. This failure point will be thrown away if an attempt
          435            is made to use it for a failure.  A `+' construct makes this
          436            before the first repeat.  Also used as an intermediary kind
          437            of jump when compiling an alternative.  */
          438   dummy_failure_jump,
          439 
          440         /* Push a dummy failure point and continue.  Used at the end of
          441            alternatives.  */
          442   push_dummy_failure,
          443 
          444         /* Followed by two-byte relative address and two-byte number n.
          445            After matching N times, jump to the address upon failure.  */
          446   succeed_n,
          447 
          448         /* Followed by two-byte relative address, and two-byte number n.
          449            Jump to the address N times, then fail.  */
          450   jump_n,
          451 
          452         /* Set the following two-byte relative address to the
          453            subsequent two-byte number.  The address *includes* the two
          454            bytes of number.  */
          455   set_number_at,
          456 
          457   wordchar,        /* Matches any word-constituent character.  */
          458   notwordchar,        /* Matches any char that is not a word-constituent.  */
          459 
          460   wordbeg,        /* Succeeds if at word beginning.  */
          461   wordend,        /* Succeeds if at word end.  */
          462 
          463   wordbound,        /* Succeeds if at a word boundary.  */
          464   notwordbound        /* Succeeds if not at a word boundary.  */
          465 
          466 #ifdef emacs
          467   ,before_dot,        /* Succeeds if before point.  */
          468   at_dot,        /* Succeeds if at point.  */
          469   after_dot,        /* Succeeds if after point.  */
          470 
          471         /* Matches any character whose syntax is specified.  Followed by
          472            a byte which contains a syntax code, e.g., Sword.  */
          473   syntaxspec,
          474 
          475         /* Matches any character whose syntax is not that specified.  */
          476   notsyntaxspec
          477 #endif /* emacs */
          478 } re_opcode_t;
          479 
          480 /* Common operations on the compiled pattern.  */
          481 
          482 /* Store NUMBER in two contiguous bytes starting at DESTINATION.  */
          483 
          484 #define STORE_NUMBER(destination, number)                                \
          485   do {                                                                        \
          486     (destination)[0] = (number) & 0377;                                        \
          487     (destination)[1] = (number) >> 8;                                        \
          488   } while (0)
          489 
          490 /* Same as STORE_NUMBER, except increment DESTINATION to
          491    the byte after where the number is stored.  Therefore, DESTINATION
          492    must be an lvalue.  */
          493 
          494 #define STORE_NUMBER_AND_INCR(destination, number)                        \
          495   do {                                                                        \
          496     STORE_NUMBER (destination, number);                                        \
          497     (destination) += 2;                                                        \
          498   } while (0)
          499 
          500 /* Put into DESTINATION a number stored in two contiguous bytes starting
          501    at SOURCE.  */
          502 
          503 #define EXTRACT_NUMBER(destination, source)                                \
          504   do {                                                                        \
          505     (destination) = *(source) & 0377;                                        \
          506     (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8;                \
          507   } while (0)
          508 
          509 #ifdef DEBUG
          510 static void extract_number _RE_ARGS ((int *dest, unsigned char *source));
          511 static void
          512 extract_number (dest, source)
          513     int *dest;
          514     unsigned char *source;
          515 {
          516   int temp = SIGN_EXTEND_CHAR (*(source + 1));
          517   *dest = *source & 0377;
          518   *dest += temp << 8;
          519 }
          520 
          521 #ifndef EXTRACT_MACROS /* To debug the macros.  */
          522 #undef EXTRACT_NUMBER
          523 #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
          524 #endif /* not EXTRACT_MACROS */
          525 
          526 #endif /* DEBUG */
          527 
          528 /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
          529    SOURCE must be an lvalue.  */
          530 
          531 #define EXTRACT_NUMBER_AND_INCR(destination, source)                        \
          532   do {                                                                        \
          533     EXTRACT_NUMBER (destination, source);                                \
          534     (source) += 2;                                                         \
          535   } while (0)
          536 
          537 #ifdef DEBUG
          538 static void extract_number_and_incr _RE_ARGS ((int *destination,
          539                                                unsigned char **source));
          540 static void
          541 extract_number_and_incr (destination, source)
          542     int *destination;
          543     unsigned char **source;
          544 {
          545   extract_number (destination, *source);
          546   *source += 2;
          547 }
          548 
          549 #ifndef EXTRACT_MACROS
          550 #undef EXTRACT_NUMBER_AND_INCR
          551 #define EXTRACT_NUMBER_AND_INCR(dest, src) \
          552   extract_number_and_incr (&dest, &src)
          553 #endif /* not EXTRACT_MACROS */
          554 
          555 #endif /* DEBUG */
          556 
          557 /* If DEBUG is defined, Regex prints many voluminous messages about what
          558    it is doing (if the variable `debug' is nonzero).  If linked with the
          559    main program in `iregex.c', you can enter patterns and strings
          560    interactively.  And if linked with the main program in `main.c' and
          561    the other test files, you can run the already-written tests.  */
          562 
          563 #ifdef DEBUG
          564 
          565 /* We use standard I/O for debugging.  */
          566 #include <stdio.h>
          567 
          568 /* It is useful to test things that ``must'' be true when debugging.  */
          569 #include <assert.h>
          570 
          571 static int debug = 0;
          572 
          573 #define DEBUG_STATEMENT(e) e
          574 #define DEBUG_PRINT1(x) if (debug) printf (x)
          575 #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
          576 #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
          577 #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
          578 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)                                 \
          579   if (debug) print_partial_compiled_pattern (s, e)
          580 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)                        \
          581   if (debug) print_double_string (w, s1, sz1, s2, sz2)
          582 
          583 
          584 /* Print the fastmap in human-readable form.  */
          585 
          586 void
          587 print_fastmap (fastmap)
          588     char *fastmap;
          589 {
          590   unsigned was_a_range = 0;
          591   unsigned i = 0;
          592 
          593   while (i < (1 << BYTEWIDTH))
          594     {
          595       if (fastmap[i++])
          596         {
          597           was_a_range = 0;
          598           putchar (i - 1);
          599           while (i < (1 << BYTEWIDTH)  &&  fastmap[i])
          600             {
          601               was_a_range = 1;
          602               i++;
          603             }
          604           if (was_a_range)
          605             {
          606               printf ("-");
          607               putchar (i - 1);
          608             }
          609         }
          610     }
          611   putchar ('\n');
          612 }
          613 
          614 
          615 /* Print a compiled pattern string in human-readable form, starting at
          616    the START pointer into it and ending just before the pointer END.  */
          617 
          618 void
          619 print_partial_compiled_pattern (start, end)
          620     unsigned char *start;
          621     unsigned char *end;
          622 {
          623   int mcnt, mcnt2;
          624   unsigned char *p1;
          625   unsigned char *p = start;
          626   unsigned char *pend = end;
          627 
          628   if (start == NULL)
          629     {
          630       printf ("(null)\n");
          631       return;
          632     }
          633 
          634   /* Loop over pattern commands.  */
          635   while (p < pend)
          636     {
          637       printf ("%d:\t", p - start);
          638 
          639       switch ((re_opcode_t) *p++)
          640         {
          641         case no_op:
          642           printf ("/no_op");
          643           break;
          644 
          645         case exactn:
          646           mcnt = *p++;
          647           printf ("/exactn/%d", mcnt);
          648           do
          649             {
          650               putchar ('/');
          651               putchar (*p++);
          652             }
          653           while (--mcnt);
          654           break;
          655 
          656         case start_memory:
          657           mcnt = *p++;
          658           printf ("/start_memory/%d/%d", mcnt, *p++);
          659           break;
          660 
          661         case stop_memory:
          662           mcnt = *p++;
          663           printf ("/stop_memory/%d/%d", mcnt, *p++);
          664           break;
          665 
          666         case duplicate:
          667           printf ("/duplicate/%d", *p++);
          668           break;
          669 
          670         case anychar:
          671           printf ("/anychar");
          672           break;
          673 
          674         case charset:
          675         case charset_not:
          676           {
          677             register int c, last = -100;
          678             register int in_range = 0;
          679 
          680             printf ("/charset [%s",
          681                     (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
          682 
          683             assert (p + *p < pend);
          684 
          685             for (c = 0; c < 256; c++)
          686               if (c / 8 < *p
          687                   && (p[1 + (c/8)] & (1 << (c % 8))))
          688                 {
          689                   /* Are we starting a range?  */
          690                   if (last + 1 == c && ! in_range)
          691                     {
          692                       putchar ('-');
          693                       in_range = 1;
          694                     }
          695                   /* Have we broken a range?  */
          696                   else if (last + 1 != c && in_range)
          697               {
          698                       putchar (last);
          699                       in_range = 0;
          700                     }
          701 
          702                   if (! in_range)
          703                     putchar (c);
          704 
          705                   last = c;
          706               }
          707 
          708             if (in_range)
          709               putchar (last);
          710 
          711             putchar (']');
          712 
          713             p += 1 + *p;
          714           }
          715           break;
          716 
          717         case begline:
          718           printf ("/begline");
          719           break;
          720 
          721         case endline:
          722           printf ("/endline");
          723           break;
          724 
          725         case on_failure_jump:
          726           extract_number_and_incr (&mcnt, &p);
          727             printf ("/on_failure_jump to %d", p + mcnt - start);
          728           break;
          729 
          730         case on_failure_keep_string_jump:
          731           extract_number_and_incr (&mcnt, &p);
          732             printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
          733           break;
          734 
          735         case dummy_failure_jump:
          736           extract_number_and_incr (&mcnt, &p);
          737             printf ("/dummy_failure_jump to %d", p + mcnt - start);
          738           break;
          739 
          740         case push_dummy_failure:
          741           printf ("/push_dummy_failure");
          742           break;
          743 
          744         case maybe_pop_jump:
          745           extract_number_and_incr (&mcnt, &p);
          746             printf ("/maybe_pop_jump to %d", p + mcnt - start);
          747           break;
          748 
          749         case pop_failure_jump:
          750           extract_number_and_incr (&mcnt, &p);
          751             printf ("/pop_failure_jump to %d", p + mcnt - start);
          752           break;
          753 
          754         case jump_past_alt:
          755           extract_number_and_incr (&mcnt, &p);
          756             printf ("/jump_past_alt to %d", p + mcnt - start);
          757           break;
          758 
          759         case jump:
          760           extract_number_and_incr (&mcnt, &p);
          761             printf ("/jump to %d", p + mcnt - start);
          762           break;
          763 
          764         case succeed_n:
          765           extract_number_and_incr (&mcnt, &p);
          766           p1 = p + mcnt;
          767           extract_number_and_incr (&mcnt2, &p);
          768           printf ("/succeed_n to %d, %d times", p1 - start, mcnt2);
          769           break;
          770 
          771         case jump_n:
          772           extract_number_and_incr (&mcnt, &p);
          773           p1 = p + mcnt;
          774           extract_number_and_incr (&mcnt2, &p);
          775           printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
          776           break;
          777 
          778         case set_number_at:
          779           extract_number_and_incr (&mcnt, &p);
          780           p1 = p + mcnt;
          781           extract_number_and_incr (&mcnt2, &p);
          782           printf ("/set_number_at location %d to %d", p1 - start, mcnt2);
          783           break;
          784 
          785         case wordbound:
          786           printf ("/wordbound");
          787           break;
          788 
          789         case notwordbound:
          790           printf ("/notwordbound");
          791           break;
          792 
          793         case wordbeg:
          794           printf ("/wordbeg");
          795           break;
          796 
          797         case wordend:
          798           printf ("/wordend");
          799 
          800 #ifdef emacs
          801         case before_dot:
          802           printf ("/before_dot");
          803           break;
          804 
          805         case at_dot:
          806           printf ("/at_dot");
          807           break;
          808 
          809         case after_dot:
          810           printf ("/after_dot");
          811           break;
          812 
          813         case syntaxspec:
          814           printf ("/syntaxspec");
          815           mcnt = *p++;
          816           printf ("/%d", mcnt);
          817           break;
          818 
          819         case notsyntaxspec:
          820           printf ("/notsyntaxspec");
          821           mcnt = *p++;
          822           printf ("/%d", mcnt);
          823           break;
          824 #endif /* emacs */
          825 
          826         case wordchar:
          827           printf ("/wordchar");
          828           break;
          829 
          830         case notwordchar:
          831           printf ("/notwordchar");
          832           break;
          833 
          834         case begbuf:
          835           printf ("/begbuf");
          836           break;
          837 
          838         case endbuf:
          839           printf ("/endbuf");
          840           break;
          841 
          842         default:
          843           printf ("?%d", *(p-1));
          844         }
          845 
          846       putchar ('\n');
          847     }
          848 
          849   printf ("%d:\tend of pattern.\n", p - start);
          850 }
          851 
          852 
          853 void
          854 print_compiled_pattern (bufp)
          855     struct re_pattern_buffer *bufp;
          856 {
          857   unsigned char *buffer = bufp->buffer;
          858 
          859   print_partial_compiled_pattern (buffer, buffer + bufp->used);
          860   printf ("%ld bytes used/%ld bytes allocated.\n",
          861           bufp->used, bufp->allocated);
          862 
          863   if (bufp->fastmap_accurate && bufp->fastmap)
          864     {
          865       printf ("fastmap: ");
          866       print_fastmap (bufp->fastmap);
          867     }
          868 
          869   printf ("re_nsub: %d\t", bufp->re_nsub);
          870   printf ("regs_alloc: %d\t", bufp->regs_allocated);
          871   printf ("can_be_null: %d\t", bufp->can_be_null);
          872   printf ("newline_anchor: %d\n", bufp->newline_anchor);
          873   printf ("no_sub: %d\t", bufp->no_sub);
          874   printf ("not_bol: %d\t", bufp->not_bol);
          875   printf ("not_eol: %d\t", bufp->not_eol);
          876   printf ("syntax: %lx\n", bufp->syntax);
          877   /* Perhaps we should print the translate table?  */
          878 }
          879 
          880 
          881 void
          882 print_double_string (where, string1, size1, string2, size2)
          883     const char *where;
          884     const char *string1;
          885     const char *string2;
          886     int size1;
          887     int size2;
          888 {
          889   int this_char;
          890 
          891   if (where == NULL)
          892     printf ("(null)");
          893   else
          894     {
          895       if (FIRST_STRING_P (where))
          896         {
          897           for (this_char = where - string1; this_char < size1; this_char++)
          898             putchar (string1[this_char]);
          899 
          900           where = string2;
          901         }
          902 
          903       for (this_char = where - string2; this_char < size2; this_char++)
          904         putchar (string2[this_char]);
          905     }
          906 }
          907 
          908 void
          909 printchar (c)
          910      int c;
          911 {
          912   putc (c, stderr);
          913 }
          914 
          915 #else /* not DEBUG */
          916 
          917 #undef assert
          918 #define assert(e)
          919 
          920 #define DEBUG_STATEMENT(e)
          921 #define DEBUG_PRINT1(x)
          922 #define DEBUG_PRINT2(x1, x2)
          923 #define DEBUG_PRINT3(x1, x2, x3)
          924 #define DEBUG_PRINT4(x1, x2, x3, x4)
          925 #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
          926 #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
          927 
          928 #endif /* not DEBUG */
          929 
          930 /* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
          931    also be assigned to arbitrarily: each pattern buffer stores its own
          932    syntax, so it can be changed between regex compilations.  */
          933 /* This has no initializer because initialized variables in Emacs
          934    become read-only after dumping.  */
          935 reg_syntax_t re_syntax_options;
          936 
          937 
          938 /* Specify the precise syntax of regexps for compilation.  This provides
          939    for compatibility for various utilities which historically have
          940    different, incompatible syntaxes.
          941 
          942    The argument SYNTAX is a bit mask comprised of the various bits
          943    defined in regex.h.  We return the old syntax.  */
          944 
          945 reg_syntax_t
          946 re_set_syntax (syntax)
          947     reg_syntax_t syntax;
          948 {
          949   reg_syntax_t ret = re_syntax_options;
          950 
          951   re_syntax_options = syntax;
          952 #ifdef DEBUG
          953   if (syntax & RE_DEBUG)
          954     debug = 1;
          955   else if (debug) /* was on but now is not */
          956     debug = 0;
          957 #endif /* DEBUG */
          958   return ret;
          959 }
          960 
          961 void
          962 #if __STDC__
          963 re_set_character_syntax (unsigned char ch, char syntax)
          964 #else
          965 re_set_character_syntax (ch, syntax)
          966      unsigned char ch;
          967      char syntax;
          968 #endif /* not __STDC__ */
          969 {
          970   init_syntax_once ();
          971 
          972   switch (syntax)
          973     {
          974     case 'w':
          975       SYNTAX (ch) = Sword;
          976       break;
          977 
          978     case ' ':
          979       SYNTAX (ch) = 0;
          980       break;
          981 
          982     default:
          983       /* This is an error, but we don't care. */
          984       break;
          985     }
          986 }
          987 
          988 
          989 /* This table gives an error message for each of the error codes listed
          990    in regex.h.  Obviously the order here has to be same as there.
          991    POSIX doesn't require that we do anything for REG_NOERROR,
          992    but why not be nice?  */
          993 
          994 static const char *re_error_msgid[] =
          995   {
          996     gettext_noop ("Success"),        /* REG_NOERROR */
          997     gettext_noop ("No match"),        /* REG_NOMATCH */
          998     gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
          999     gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
         1000     gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
         1001     gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
         1002     gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
         1003     gettext_noop ("Unmatched [ or [^"),        /* REG_EBRACK */
         1004     gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
         1005     gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
         1006     gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
         1007     gettext_noop ("Invalid range end"),        /* REG_ERANGE */
         1008     gettext_noop ("Memory exhausted"), /* REG_ESPACE */
         1009     gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
         1010     gettext_noop ("Premature end of regular expression"), /* REG_EEND */
         1011     gettext_noop ("Regular expression too big"), /* REG_ESIZE */
         1012     gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
         1013   };
         1014 
         1015 /* Avoiding alloca during matching, to placate r_alloc.  */
         1016 
         1017 /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
         1018    searching and matching functions should not call alloca.  On some
         1019    systems, alloca is implemented in terms of malloc, and if we're
         1020    using the relocating allocator routines, then malloc could cause a
         1021    relocation, which might (if the strings being searched are in the
         1022    ralloc heap) shift the data out from underneath the regexp
         1023    routines.
         1024 
         1025    Here's another reason to avoid allocation: Emacs
         1026    processes input from X in a signal handler; processing X input may
         1027    call malloc; if input arrives while a matching routine is calling
         1028    malloc, then we're scrod.  But Emacs can't just block input while
         1029    calling matching routines; then we don't notice interrupts when
         1030    they come in.  So, Emacs blocks input around all regexp calls
         1031    except the matching calls, which it leaves unprotected, in the
         1032    faith that they will not malloc.  */
         1033 
         1034 /* Normally, this is fine.  */
         1035 #define MATCH_MAY_ALLOCATE
         1036 
         1037 /* When using GNU C, we are not REALLY using the C alloca, no matter
         1038    what config.h may say.  So don't take precautions for it.  */
         1039 #ifdef __GNUC__
         1040 #undef C_ALLOCA
         1041 #endif
         1042 
         1043 /* The match routines may not allocate if (1) they would do it with malloc
         1044    and (2) it's not safe for them to use malloc.
         1045    Note that if REL_ALLOC is defined, matching would not use malloc for the
         1046    failure stack, but we would still use it for the register vectors;
         1047    so REL_ALLOC should not affect this.  */
         1048 #if (defined (C_ALLOCA) || defined (REGEX_MALLOC)) && defined (emacs)
         1049 #undef MATCH_MAY_ALLOCATE
         1050 #endif
         1051 
         1052 
         1053 /* Failure stack declarations and macros; both re_compile_fastmap and
         1054    re_match_2 use a failure stack.  These have to be macros because of
         1055    REGEX_ALLOCATE_STACK.  */
         1056 
         1057 
         1058 /* Number of failure points for which to initially allocate space
         1059    when matching.  If this number is exceeded, we allocate more
         1060    space, so it is not a hard limit.  */
         1061 #ifndef INIT_FAILURE_ALLOC
         1062 #define INIT_FAILURE_ALLOC 5
         1063 #endif
         1064 
         1065 /* Roughly the maximum number of failure points on the stack.  Would be
         1066    exactly that if always used MAX_FAILURE_ITEMS items each time we failed.
         1067    This is a variable only so users of regex can assign to it; we never
         1068    change it ourselves.  */
         1069 
         1070 #ifdef INT_IS_16BIT
         1071 
         1072 #if defined (MATCH_MAY_ALLOCATE)
         1073 /* 4400 was enough to cause a crash on Alpha OSF/1,
         1074    whose default stack limit is 2mb.  */
         1075 long int re_max_failures = 4000;
         1076 #else
         1077 long int re_max_failures = 2000;
         1078 #endif
         1079 
         1080 union fail_stack_elt
         1081 {
         1082   unsigned char *pointer;
         1083   long int integer;
         1084 };
         1085 
         1086 typedef union fail_stack_elt fail_stack_elt_t;
         1087 
         1088 typedef struct
         1089 {
         1090   fail_stack_elt_t *stack;
         1091   unsigned long int size;
         1092   unsigned long int avail;                /* Offset of next open position.  */
         1093 } fail_stack_type;
         1094 
         1095 #else /* not INT_IS_16BIT */
         1096 
         1097 #if defined (MATCH_MAY_ALLOCATE)
         1098 /* 4400 was enough to cause a crash on Alpha OSF/1,
         1099    whose default stack limit is 2mb.  */
         1100 int re_max_failures = 20000;
         1101 #else
         1102 int re_max_failures = 2000;
         1103 #endif
         1104 
         1105 union fail_stack_elt
         1106 {
         1107   unsigned char *pointer;
         1108   int integer;
         1109 };
         1110 
         1111 typedef union fail_stack_elt fail_stack_elt_t;
         1112 
         1113 typedef struct
         1114 {
         1115   fail_stack_elt_t *stack;
         1116   unsigned size;
         1117   unsigned avail;                        /* Offset of next open position.  */
         1118 } fail_stack_type;
         1119 
         1120 #endif /* INT_IS_16BIT */
         1121 
         1122 #define FAIL_STACK_EMPTY()     (fail_stack.avail == 0)
         1123 #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
         1124 #define FAIL_STACK_FULL()      (fail_stack.avail == fail_stack.size)
         1125 
         1126 
         1127 /* Define macros to initialize and free the failure stack.
         1128    Do `return -2' if the alloc fails.  */
         1129 
         1130 #ifdef MATCH_MAY_ALLOCATE
         1131 #define INIT_FAIL_STACK()                                                \
         1132   do {                                                                        \
         1133     fail_stack.stack = (fail_stack_elt_t *)                                \
         1134       REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t));        \
         1135                                                                         \
         1136     if (fail_stack.stack == NULL)                                        \
         1137       return -2;                                                        \
         1138                                                                         \
         1139     fail_stack.size = INIT_FAILURE_ALLOC;                                \
         1140     fail_stack.avail = 0;                                                \
         1141   } while (0)
         1142 
         1143 #define RESET_FAIL_STACK()  REGEX_FREE_STACK (fail_stack.stack)
         1144 #else
         1145 #define INIT_FAIL_STACK()                                                \
         1146   do {                                                                        \
         1147     fail_stack.avail = 0;                                                \
         1148   } while (0)
         1149 
         1150 #define RESET_FAIL_STACK()
         1151 #endif
         1152 
         1153 
         1154 /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.
         1155 
         1156    Return 1 if succeeds, and 0 if either ran out of memory
         1157    allocating space for it or it was already too large.
         1158 
         1159    REGEX_REALLOCATE_STACK requires `destination' be declared.   */
         1160 
         1161 #define DOUBLE_FAIL_STACK(fail_stack)                                        \
         1162   ((fail_stack).size > (unsigned) (re_max_failures * MAX_FAILURE_ITEMS)        \
         1163    ? 0                                                                        \
         1164    : ((fail_stack).stack = (fail_stack_elt_t *)                                \
         1165         REGEX_REALLOCATE_STACK ((fail_stack).stack,                         \
         1166           (fail_stack).size * sizeof (fail_stack_elt_t),                \
         1167           ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)),        \
         1168                                                                         \
         1169       (fail_stack).stack == NULL                                        \
         1170       ? 0                                                                \
         1171       : ((fail_stack).size <<= 1,                                         \
         1172          1)))
         1173 
         1174 
         1175 /* Push pointer POINTER on FAIL_STACK.
         1176    Return 1 if was able to do so and 0 if ran out of memory allocating
         1177    space to do so.  */
         1178 #define PUSH_PATTERN_OP(POINTER, FAIL_STACK)                                \
         1179   ((FAIL_STACK_FULL ()                                                        \
         1180     && !DOUBLE_FAIL_STACK (FAIL_STACK))                                        \
         1181    ? 0                                                                        \
         1182    : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER,        \
         1183       1))
         1184 
         1185 /* Push a pointer value onto the failure stack.
         1186    Assumes the variable `fail_stack'.  Probably should only
         1187    be called from within `PUSH_FAILURE_POINT'.  */
         1188 #define PUSH_FAILURE_POINTER(item)                                        \
         1189   fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)
         1190 
         1191 /* This pushes an integer-valued item onto the failure stack.
         1192    Assumes the variable `fail_stack'.  Probably should only
         1193    be called from within `PUSH_FAILURE_POINT'.  */
         1194 #define PUSH_FAILURE_INT(item)                                        \
         1195   fail_stack.stack[fail_stack.avail++].integer = (item)
         1196 
         1197 /* Push a fail_stack_elt_t value onto the failure stack.
         1198    Assumes the variable `fail_stack'.  Probably should only
         1199    be called from within `PUSH_FAILURE_POINT'.  */
         1200 #define PUSH_FAILURE_ELT(item)                                        \
         1201   fail_stack.stack[fail_stack.avail++] =  (item)
         1202 
         1203 /* These three POP... operations complement the three PUSH... operations.
         1204    All assume that `fail_stack' is nonempty.  */
         1205 #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
         1206 #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
         1207 #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
         1208 
         1209 /* Used to omit pushing failure point id's when we're not debugging.  */
         1210 #ifdef DEBUG
         1211 #define DEBUG_PUSH PUSH_FAILURE_INT
         1212 #define DEBUG_POP(item_addr) (item_addr)->integer = POP_FAILURE_INT ()
         1213 #else
         1214 #define DEBUG_PUSH(item)
         1215 #define DEBUG_POP(item_addr)
         1216 #endif
         1217 
         1218 
         1219 /* Push the information about the state we will need
         1220    if we ever fail back to it.
         1221 
         1222    Requires variables fail_stack, regstart, regend, reg_info, and
         1223    num_regs be declared.  DOUBLE_FAIL_STACK requires `destination' be
         1224    declared.
         1225 
         1226    Does `return FAILURE_CODE' if runs out of memory.  */
         1227 
         1228 #define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code)        \
         1229   do {                                                                        \
         1230     char *destination;                                                        \
         1231     /* Must be int, so when we don't save any registers, the arithmetic        \
         1232        of 0 + -1 isn't done as unsigned.  */                                \
         1233     /* Can't be int, since there is not a shred of a guarantee that int        \
         1234        is wide enough to hold a value of something to which pointer can        \
         1235        be assigned */                                                        \
         1236     s_reg_t this_reg;                                                        \
         1237                                                                             \
         1238     DEBUG_STATEMENT (failure_id++);                                        \
         1239     DEBUG_STATEMENT (nfailure_points_pushed++);                                \
         1240     DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id);                \
         1241     DEBUG_PRINT2 ("  Before push, next avail: %d\n", (fail_stack).avail);\
         1242     DEBUG_PRINT2 ("                     size: %d\n", (fail_stack).size);\
         1243                                                                         \
         1244     DEBUG_PRINT2 ("  slots needed: %d\n", NUM_FAILURE_ITEMS);                \
         1245     DEBUG_PRINT2 ("     available: %d\n", REMAINING_AVAIL_SLOTS);        \
         1246                                                                         \
         1247     /* Ensure we have enough space allocated for what we will push.  */        \
         1248     while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS)                        \
         1249       {                                                                        \
         1250         if (!DOUBLE_FAIL_STACK (fail_stack))                                \
         1251           return failure_code;                                                \
         1252                                                                         \
         1253         DEBUG_PRINT2 ("\n  Doubled stack; size now: %d\n",                \
         1254                        (fail_stack).size);                                \
         1255         DEBUG_PRINT2 ("  slots available: %d\n", REMAINING_AVAIL_SLOTS);\
         1256       }                                                                        \
         1257                                                                         \
         1258     /* Push the info, starting with the registers.  */                        \
         1259     DEBUG_PRINT1 ("\n");                                                \
         1260                                                                         \
         1261     if (1)                                                                \
         1262       for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
         1263            this_reg++)                                                        \
         1264         {                                                                \
         1265           DEBUG_PRINT2 ("  Pushing reg: %d\n", this_reg);                \
         1266           DEBUG_STATEMENT (num_regs_pushed++);                                \
         1267                                                                         \
         1268           DEBUG_PRINT2 ("    start: 0x%x\n", regstart[this_reg]);        \
         1269           PUSH_FAILURE_POINTER (regstart[this_reg]);                        \
         1270                                                                         \
         1271           DEBUG_PRINT2 ("    end: 0x%x\n", regend[this_reg]);                \
         1272           PUSH_FAILURE_POINTER (regend[this_reg]);                        \
         1273                                                                         \
         1274           DEBUG_PRINT2 ("    info: 0x%x\n      ", reg_info[this_reg]);        \
         1275           DEBUG_PRINT2 (" match_null=%d",                                \
         1276                         REG_MATCH_NULL_STRING_P (reg_info[this_reg]));        \
         1277           DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg]));        \
         1278           DEBUG_PRINT2 (" matched_something=%d",                        \
         1279                         MATCHED_SOMETHING (reg_info[this_reg]));        \
         1280           DEBUG_PRINT2 (" ever_matched=%d",                                \
         1281                         EVER_MATCHED_SOMETHING (reg_info[this_reg]));        \
         1282           DEBUG_PRINT1 ("\n");                                                \
         1283           PUSH_FAILURE_ELT (reg_info[this_reg].word);                        \
         1284         }                                                                \
         1285                                                                         \
         1286     DEBUG_PRINT2 ("  Pushing  low active reg: %d\n", lowest_active_reg);\
         1287     PUSH_FAILURE_INT (lowest_active_reg);                                \
         1288                                                                         \
         1289     DEBUG_PRINT2 ("  Pushing high active reg: %d\n", highest_active_reg);\
         1290     PUSH_FAILURE_INT (highest_active_reg);                                \
         1291                                                                         \
         1292     DEBUG_PRINT2 ("  Pushing pattern 0x%x:\n", pattern_place);                \
         1293     DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend);                \
         1294     PUSH_FAILURE_POINTER (pattern_place);                                \
         1295                                                                         \
         1296     DEBUG_PRINT2 ("  Pushing string 0x%x: `", string_place);                \
         1297     DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2,   \
         1298                                  size2);                                \
         1299     DEBUG_PRINT1 ("'\n");                                                \
         1300     PUSH_FAILURE_POINTER (string_place);                                \
         1301                                                                         \
         1302     DEBUG_PRINT2 ("  Pushing failure id: %u\n", failure_id);                \
         1303     DEBUG_PUSH (failure_id);                                                \
         1304   } while (0)
         1305 
         1306 /* This is the number of items that are pushed and popped on the stack
         1307    for each register.  */
         1308 #define NUM_REG_ITEMS  3
         1309 
         1310 /* Individual items aside from the registers.  */
         1311 #ifdef DEBUG
         1312 #define NUM_NONREG_ITEMS 5 /* Includes failure point id.  */
         1313 #else
         1314 #define NUM_NONREG_ITEMS 4
         1315 #endif
         1316 
         1317 /* We push at most this many items on the stack.  */
         1318 /* We used to use (num_regs - 1), which is the number of registers
         1319    this regexp will save; but that was changed to 5
         1320    to avoid stack overflow for a regexp with lots of parens.  */
         1321 #define MAX_FAILURE_ITEMS (5 * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
         1322 
         1323 /* We actually push this many items.  */
         1324 #define NUM_FAILURE_ITEMS                                \
         1325   (((0                                                        \
         1326      ? 0 : highest_active_reg - lowest_active_reg + 1)        \
         1327     * NUM_REG_ITEMS)                                        \
         1328    + NUM_NONREG_ITEMS)
         1329 
         1330 /* How many items can still be added to the stack without overflowing it.  */
         1331 #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
         1332 
         1333 
         1334 /* Pops what PUSH_FAIL_STACK pushes.
         1335 
         1336    We restore into the parameters, all of which should be lvalues:
         1337      STR -- the saved data position.
         1338      PAT -- the saved pattern position.
         1339      LOW_REG, HIGH_REG -- the highest and lowest active registers.
         1340      REGSTART, REGEND -- arrays of string positions.
         1341      REG_INFO -- array of information about each subexpression.
         1342 
         1343    Also assumes the variables `fail_stack' and (if debugging), `bufp',
         1344    `pend', `string1', `size1', `string2', and `size2'.  */
         1345 
         1346 #define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
         1347 {                                                                        \
         1348   DEBUG_STATEMENT (fail_stack_elt_t failure_id;)                        \
         1349   s_reg_t this_reg;                                                        \
         1350   const unsigned char *string_temp;                                        \
         1351                                                                         \
         1352   assert (!FAIL_STACK_EMPTY ());                                        \
         1353                                                                         \
         1354   /* Remove failure points and point to how many regs pushed.  */        \
         1355   DEBUG_PRINT1 ("POP_FAILURE_POINT:\n");                                \
         1356   DEBUG_PRINT2 ("  Before pop, next avail: %d\n", fail_stack.avail);        \
         1357   DEBUG_PRINT2 ("                    size: %d\n", fail_stack.size);        \
         1358                                                                         \
         1359   assert (fail_stack.avail >= NUM_NONREG_ITEMS);                        \
         1360                                                                         \
         1361   DEBUG_POP (&failure_id);                                                \
         1362   DEBUG_PRINT2 ("  Popping failure id: %u\n", failure_id);                \
         1363                                                                         \
         1364   /* If the saved string location is NULL, it came from an                \
         1365      on_failure_keep_string_jump opcode, and we want to throw away the        \
         1366      saved NULL, thus retaining our current position in the string.  */        \
         1367   string_temp = POP_FAILURE_POINTER ();                                        \
         1368   if (string_temp != NULL)                                                \
         1369     str = (const char *) string_temp;                                        \
         1370                                                                         \
         1371   DEBUG_PRINT2 ("  Popping string 0x%x: `", str);                        \
         1372   DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2);        \
         1373   DEBUG_PRINT1 ("'\n");                                                        \
         1374                                                                         \
         1375   pat = (unsigned char *) POP_FAILURE_POINTER ();                        \
         1376   DEBUG_PRINT2 ("  Popping pattern 0x%x:\n", pat);                        \
         1377   DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend);                        \
         1378                                                                         \
         1379   /* Restore register info.  */                                                \
         1380   high_reg = (active_reg_t) POP_FAILURE_INT ();                                \
         1381   DEBUG_PRINT2 ("  Popping high active reg: %d\n", high_reg);                \
         1382                                                                         \
         1383   low_reg = (active_reg_t) POP_FAILURE_INT ();                                \
         1384   DEBUG_PRINT2 ("  Popping  low active reg: %d\n", low_reg);                \
         1385                                                                         \
         1386   if (1)                                                                \
         1387     for (this_reg = high_reg; this_reg >= low_reg; this_reg--)                \
         1388       {                                                                        \
         1389         DEBUG_PRINT2 ("    Popping reg: %d\n", this_reg);                \
         1390                                                                         \
         1391         reg_info[this_reg].word = POP_FAILURE_ELT ();                        \
         1392         DEBUG_PRINT2 ("      info: 0x%x\n", reg_info[this_reg]);        \
         1393                                                                         \
         1394         regend[this_reg] = (const char *) POP_FAILURE_POINTER ();        \
         1395         DEBUG_PRINT2 ("      end: 0x%x\n", regend[this_reg]);                \
         1396                                                                         \
         1397         regstart[this_reg] = (const char *) POP_FAILURE_POINTER ();        \
         1398         DEBUG_PRINT2 ("      start: 0x%x\n", regstart[this_reg]);        \
         1399       }                                                                        \
         1400   else                                                                        \
         1401     {                                                                        \
         1402       for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \
         1403         {                                                                \
         1404           reg_info[this_reg].word.integer = 0;                                \
         1405           regend[this_reg] = 0;                                                \
         1406           regstart[this_reg] = 0;                                        \
         1407         }                                                                \
         1408       highest_active_reg = high_reg;                                        \
         1409     }                                                                        \
         1410                                                                         \
         1411   set_regs_matched_done = 0;                                                \
         1412   DEBUG_STATEMENT (nfailure_points_popped++);                                \
         1413 } /* POP_FAILURE_POINT */
         1414 
         1415 
         1416 
         1417 /* Structure for per-register (a.k.a. per-group) information.
         1418    Other register information, such as the
         1419    starting and ending positions (which are addresses), and the list of
         1420    inner groups (which is a bits list) are maintained in separate
         1421    variables.
         1422 
         1423    We are making a (strictly speaking) nonportable assumption here: that
         1424    the compiler will pack our bit fields into something that fits into
         1425    the type of `word', i.e., is something that fits into one item on the
         1426    failure stack.  */
         1427 
         1428 
         1429 /* Declarations and macros for re_match_2.  */
         1430 
         1431 typedef union
         1432 {
         1433   fail_stack_elt_t word;
         1434   struct
         1435   {
         1436       /* This field is one if this group can match the empty string,
         1437          zero if not.  If not yet determined,  `MATCH_NULL_UNSET_VALUE'.  */
         1438 #define MATCH_NULL_UNSET_VALUE 3
         1439     unsigned match_null_string_p : 2;
         1440     unsigned is_active : 1;
         1441     unsigned matched_something : 1;
         1442     unsigned ever_matched_something : 1;
         1443   } bits;
         1444 } register_info_type;
         1445 
         1446 #define REG_MATCH_NULL_STRING_P(R)  ((R).bits.match_null_string_p)
         1447 #define IS_ACTIVE(R)  ((R).bits.is_active)
         1448 #define MATCHED_SOMETHING(R)  ((R).bits.matched_something)
         1449 #define EVER_MATCHED_SOMETHING(R)  ((R).bits.ever_matched_something)
         1450 
         1451 
         1452 /* Call this when have matched a real character; it sets `matched' flags
         1453    for the subexpressions which we are currently inside.  Also records
         1454    that those subexprs have matched.  */
         1455 #define SET_REGS_MATCHED()                                                \
         1456   do                                                                        \
         1457     {                                                                        \
         1458       if (!set_regs_matched_done)                                        \
         1459         {                                                                \
         1460           active_reg_t r;                                                \
         1461           set_regs_matched_done = 1;                                        \
         1462           for (r = lowest_active_reg; r <= highest_active_reg; r++)        \
         1463             {                                                                \
         1464               MATCHED_SOMETHING (reg_info[r])                                \
         1465                 = EVER_MATCHED_SOMETHING (reg_info[r])                        \
         1466                 = 1;                                                        \
         1467             }                                                                \
         1468         }                                                                \
         1469     }                                                                        \
         1470   while (0)
         1471 
         1472 /* Registers are set to a sentinel when they haven't yet matched.  */
         1473 static char reg_unset_dummy;
         1474 #define REG_UNSET_VALUE (&reg_unset_dummy)
         1475 #define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
         1476 
         1477 /* Subroutine declarations and macros for regex_compile.  */
         1478 
         1479 static reg_errcode_t regex_compile _RE_ARGS ((const char *pattern, size_t size,
         1480                                               reg_syntax_t syntax,
         1481                                               struct re_pattern_buffer *bufp));
         1482 static void store_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg));
         1483 static void store_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
         1484                                  int arg1, int arg2));
         1485 static void insert_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
         1486                                   int arg, unsigned char *end));
         1487 static void insert_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
         1488                                   int arg1, int arg2, unsigned char *end));
         1489 static boolean at_begline_loc_p _RE_ARGS ((const char *pattern, const char *p,
         1490                                            reg_syntax_t syntax));
         1491 static boolean at_endline_loc_p _RE_ARGS ((const char *p, const char *pend,
         1492                                            reg_syntax_t syntax));
         1493 static reg_errcode_t compile_range _RE_ARGS ((const char **p_ptr,
         1494                                               const char *pend,
         1495                                               char *translate,
         1496                                               reg_syntax_t syntax,
         1497                                               unsigned char *b));
         1498 
         1499 /* Fetch the next character in the uncompiled pattern---translating it
         1500    if necessary.  Also cast from a signed character in the constant
         1501    string passed to us by the user to an unsigned char that we can use
         1502    as an array index (in, e.g., `translate').  */
         1503 #ifndef PATFETCH
         1504 #define PATFETCH(c)                                                        \
         1505   do {if (p == pend) return REG_EEND;                                        \
         1506     c = (unsigned char) *p++;                                                \
         1507     if (translate) c = (unsigned char) translate[c];                        \
         1508   } while (0)
         1509 #endif
         1510 
         1511 /* Fetch the next character in the uncompiled pattern, with no
         1512    translation.  */
         1513 #define PATFETCH_RAW(c)                                                        \
         1514   do {if (p == pend) return REG_EEND;                                        \
         1515     c = (unsigned char) *p++;                                                 \
         1516   } while (0)
         1517 
         1518 /* Go backwards one character in the pattern.  */
         1519 #define PATUNFETCH p--
         1520 
         1521 
         1522 /* If `translate' is non-null, return translate[D], else just D.  We
         1523    cast the subscript to translate because some data is declared as
         1524    `char *', to avoid warnings when a string constant is passed.  But
         1525    when we use a character as a subscript we must make it unsigned.  */
         1526 #ifndef TRANSLATE
         1527 #define TRANSLATE(d) \
         1528   (translate ? (char) translate[(unsigned char) (d)] : (d))
         1529 #endif
         1530 
         1531 
         1532 /* Macros for outputting the compiled pattern into `buffer'.  */
         1533 
         1534 /* If the buffer isn't allocated when it comes in, use this.  */
         1535 #define INIT_BUF_SIZE  32
         1536 
         1537 /* Make sure we have at least N more bytes of space in buffer.  */
         1538 #define GET_BUFFER_SPACE(n)                                                \
         1539     while ((unsigned long) (b - bufp->buffer + (n)) > bufp->allocated)        \
         1540       EXTEND_BUFFER ()
         1541 
         1542 /* Make sure we have one more byte of buffer space and then add C to it.  */
         1543 #define BUF_PUSH(c)                                                        \
         1544   do {                                                                        \
         1545     GET_BUFFER_SPACE (1);                                                \
         1546     *b++ = (unsigned char) (c);                                                \
         1547   } while (0)
         1548 
         1549 
         1550 /* Ensure we have two more bytes of buffer space and then append C1 and C2.  */
         1551 #define BUF_PUSH_2(c1, c2)                                                \
         1552   do {                                                                        \
         1553     GET_BUFFER_SPACE (2);                                                \
         1554     *b++ = (unsigned char) (c1);                                        \
         1555     *b++ = (unsigned char) (c2);                                        \
         1556   } while (0)
         1557 
         1558 
         1559 /* As with BUF_PUSH_2, except for three bytes.  */
         1560 #define BUF_PUSH_3(c1, c2, c3)                                                \
         1561   do {                                                                        \
         1562     GET_BUFFER_SPACE (3);                                                \
         1563     *b++ = (unsigned char) (c1);                                        \
         1564     *b++ = (unsigned char) (c2);                                        \
         1565     *b++ = (unsigned char) (c3);                                        \
         1566   } while (0)
         1567 
         1568 
         1569 /* Store a jump with opcode OP at LOC to location TO.  We store a
         1570    relative address offset by the three bytes the jump itself occupies.  */
         1571 #define STORE_JUMP(op, loc, to) \
         1572   store_op1 (op, loc, (int) ((to) - (loc) - 3))
         1573 
         1574 /* Likewise, for a two-argument jump.  */
         1575 #define STORE_JUMP2(op, loc, to, arg) \
         1576   store_op2 (op, loc, (int) ((to) - (loc) - 3), arg)
         1577 
         1578 /* Like `STORE_JUMP', but for inserting.  Assume `b' is the buffer end.  */
         1579 #define INSERT_JUMP(op, loc, to) \
         1580   insert_op1 (op, loc, (int) ((to) - (loc) - 3), b)
         1581 
         1582 /* Like `STORE_JUMP2', but for inserting.  Assume `b' is the buffer end.  */
         1583 #define INSERT_JUMP2(op, loc, to, arg) \
         1584   insert_op2 (op, loc, (int) ((to) - (loc) - 3), arg, b)
         1585 
         1586 
         1587 /* This is not an arbitrary limit: the arguments which represent offsets
         1588    into the pattern are two bytes long.  So if 2^16 bytes turns out to
         1589    be too small, many things would have to change.  */
         1590 /* Any other compiler which, like MSC, has allocation limit below 2^16
         1591    bytes will have to use approach similar to what was done below for
         1592    MSC and drop MAX_BUF_SIZE a bit.  Otherwise you may end up
         1593    reallocating to 0 bytes.  Such thing is not going to work too well.
         1594    You have been warned!!  */
         1595 #if defined(_MSC_VER) && !defined(WIN32)
         1596 /* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
         1597    The REALLOC define eliminates a flurry of conversion warnings,
         1598    but is not required. */
         1599 #define MAX_BUF_SIZE  65500L
         1600 #define REALLOC(p,s) realloc ((p), (size_t) (s))
         1601 #else
         1602 #define MAX_BUF_SIZE (1L << 16)
         1603 #define REALLOC(p,s) realloc ((p), (s))
         1604 #endif
         1605 
         1606 /* Extend the buffer by twice its current size via realloc and
         1607    reset the pointers that pointed into the old block to point to the
         1608    correct places in the new one.  If extending the buffer results in it
         1609    being larger than MAX_BUF_SIZE, then flag memory exhausted.  */
         1610 #define EXTEND_BUFFER()                                                        \
         1611   do {                                                                         \
         1612     unsigned char *old_buffer = bufp->buffer;                                \
         1613     if (bufp->allocated == MAX_BUF_SIZE)                                 \
         1614       return REG_ESIZE;                                                        \
         1615     bufp->allocated <<= 1;                                                \
         1616     if (bufp->allocated > MAX_BUF_SIZE)                                        \
         1617       bufp->allocated = MAX_BUF_SIZE;                                         \
         1618     bufp->buffer = (unsigned char *) REALLOC (bufp->buffer, bufp->allocated);\
         1619     if (bufp->buffer == NULL)                                                \
         1620       return REG_ESPACE;                                                \
         1621     /* If the buffer moved, move all the pointers into it.  */                \
         1622     if (old_buffer != bufp->buffer)                                        \
         1623       {                                                                        \
         1624         b = (b - old_buffer) + bufp->buffer;                                \
         1625         begalt = (begalt - old_buffer) + bufp->buffer;                        \
         1626         if (fixup_alt_jump)                                                \
         1627           fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
         1628         if (laststart)                                                        \
         1629           laststart = (laststart - old_buffer) + bufp->buffer;                \
         1630         if (pending_exact)                                                \
         1631           pending_exact = (pending_exact - old_buffer) + bufp->buffer;        \
         1632       }                                                                        \
         1633   } while (0)
         1634 
         1635 
         1636 /* Since we have one byte reserved for the register number argument to
         1637    {start,stop}_memory, the maximum number of groups we can report
         1638    things about is what fits in that byte.  */
         1639 #define MAX_REGNUM 255
         1640 
         1641 /* But patterns can have more than `MAX_REGNUM' registers.  We just
         1642    ignore the excess.  */
         1643 typedef unsigned regnum_t;
         1644 
         1645 
         1646 /* Macros for the compile stack.  */
         1647 
         1648 /* Since offsets can go either forwards or backwards, this type needs to
         1649    be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1.  */
         1650 /* int may be not enough when sizeof(int) == 2.  */
         1651 typedef long pattern_offset_t;
         1652 
         1653 typedef struct
         1654 {
         1655   pattern_offset_t begalt_offset;
         1656   pattern_offset_t fixup_alt_jump;
         1657   pattern_offset_t inner_group_offset;
         1658   pattern_offset_t laststart_offset;
         1659   regnum_t regnum;
         1660 } compile_stack_elt_t;
         1661 
         1662 
         1663 typedef struct
         1664 {
         1665   compile_stack_elt_t *stack;
         1666   unsigned size;
         1667   unsigned avail;                        /* Offset of next open position.  */
         1668 } compile_stack_type;
         1669 
         1670 
         1671 #define INIT_COMPILE_STACK_SIZE 32
         1672 
         1673 #define COMPILE_STACK_EMPTY  (compile_stack.avail == 0)
         1674 #define COMPILE_STACK_FULL  (compile_stack.avail == compile_stack.size)
         1675 
         1676 /* The next available element.  */
         1677 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
         1678 
         1679 
         1680 /* Set the bit for character C in a list.  */
         1681 #define SET_LIST_BIT(c)                               \
         1682   (b[((unsigned char) (c)) / BYTEWIDTH]               \
         1683    |= 1 << (((unsigned char) c) % BYTEWIDTH))
         1684 
         1685 
         1686 /* Get the next unsigned number in the uncompiled pattern.  */
         1687 #define GET_UNSIGNED_NUMBER(num)                                         \
         1688   { if (p != pend)                                                        \
         1689      {                                                                        \
         1690        PATFETCH (c);                                                         \
         1691        while (ISDIGIT (c))                                                 \
         1692          {                                                                 \
         1693            if (num < 0)                                                        \
         1694               num = 0;                                                        \
         1695            num = num * 10 + c - '0';                                         \
         1696            if (p == pend)                                                 \
         1697               break;                                                         \
         1698            PATFETCH (c);                                                \
         1699          }                                                                 \
         1700        }                                                                 \
         1701     }
         1702 
         1703 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
         1704 /* The GNU C library provides support for user-defined character classes
         1705    and the functions from ISO C amendement 1.  */
         1706 # ifdef CHARCLASS_NAME_MAX
         1707 #  define CHAR_CLASS_MAX_LENGTH CHARCLASS_NAME_MAX
         1708 # else
         1709 /* This shouldn't happen but some implementation might still have this
         1710    problem.  Use a reasonable default value.  */
         1711 #  define CHAR_CLASS_MAX_LENGTH 256
         1712 # endif
         1713 
         1714 # define IS_CHAR_CLASS(string) wctype (string)
         1715 #else
         1716 # define CHAR_CLASS_MAX_LENGTH  6 /* Namely, `xdigit'.  */
         1717 
         1718 # define IS_CHAR_CLASS(string)                                                \
         1719    (STREQ (string, "alpha") || STREQ (string, "upper")                        \
         1720     || STREQ (string, "lower") || STREQ (string, "digit")                \
         1721     || STREQ (string, "alnum") || STREQ (string, "xdigit")                \
         1722     || STREQ (string, "space") || STREQ (string, "print")                \
         1723     || STREQ (string, "punct") || STREQ (string, "graph")                \
         1724     || STREQ (string, "cntrl") || STREQ (string, "blank"))
         1725 #endif
         1726 
         1727 #ifndef MATCH_MAY_ALLOCATE
         1728 
         1729 /* If we cannot allocate large objects within re_match_2_internal,
         1730    we make the fail stack and register vectors global.
         1731    The fail stack, we grow to the maximum size when a regexp
         1732    is compiled.
         1733    The register vectors, we adjust in size each time we
         1734    compile a regexp, according to the number of registers it needs.  */
         1735 
         1736 static fail_stack_type fail_stack;
         1737 
         1738 /* Size with which the following vectors are currently allocated.
         1739    That is so we can make them bigger as needed,
         1740    but never make them smaller.  */
         1741 static int regs_allocated_size;
         1742 
         1743 static const char **     regstart, **     regend;
         1744 static const char ** old_regstart, ** old_regend;
         1745 static const char **best_regstart, **best_regend;
         1746 static register_info_type *reg_info;
         1747 static const char **reg_dummy;
         1748 static register_info_type *reg_info_dummy;
         1749 
         1750 /* Make the register vectors big enough for NUM_REGS registers,
         1751    but don't make them smaller.  */
         1752 
         1753 static
         1754 regex_grow_registers (num_regs)
         1755      int num_regs;
         1756 {
         1757   if (num_regs > regs_allocated_size)
         1758     {
         1759       RETALLOC_IF (regstart,         num_regs, const char *);
         1760       RETALLOC_IF (regend,         num_regs, const char *);
         1761       RETALLOC_IF (old_regstart, num_regs, const char *);
         1762       RETALLOC_IF (old_regend,         num_regs, const char *);
         1763       RETALLOC_IF (best_regstart, num_regs, const char *);
         1764       RETALLOC_IF (best_regend,         num_regs, const char *);
         1765       RETALLOC_IF (reg_info,         num_regs, register_info_type);
         1766       RETALLOC_IF (reg_dummy,         num_regs, const char *);
         1767       RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);
         1768 
         1769       regs_allocated_size = num_regs;
         1770     }
         1771 }
         1772 
         1773 #endif /* not MATCH_MAY_ALLOCATE */
         1774 
         1775 static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
         1776                                                  compile_stack,
         1777                                                  regnum_t regnum));
         1778 
         1779 /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
         1780    Returns one of error codes defined in `regex.h', or zero for success.
         1781 
         1782    Assumes the `allocated' (and perhaps `buffer') and `translate'
         1783    fields are set in BUFP on entry.
         1784 
         1785    If it succeeds, results are put in BUFP (if it returns an error, the
         1786    contents of BUFP are undefined):
         1787      `buffer' is the compiled pattern;
         1788      `syntax' is set to SYNTAX;
         1789      `used' is set to the length of the compiled pattern;
         1790      `fastmap_accurate' is zero;
         1791      `re_nsub' is the number of subexpressions in PATTERN;
         1792      `not_bol' and `not_eol' are zero;
         1793 
         1794    The `fastmap' and `newline_anchor' fields are neither
         1795    examined nor set.  */
         1796 
         1797 /* Return, freeing storage we allocated.  */
         1798 #define FREE_STACK_RETURN(value)                \
         1799   return (free (compile_stack.stack), value)
         1800 
         1801 static reg_errcode_t
         1802 regex_compile (pattern, size, syntax, bufp)
         1803      const char *pattern;
         1804      size_t size;
         1805      reg_syntax_t syntax;
         1806      struct re_pattern_buffer *bufp;
         1807 {
         1808   /* We fetch characters from PATTERN here.  Even though PATTERN is
         1809      `char *' (i.e., signed), we declare these variables as unsigned, so
         1810      they can be reliably used as array indices.  */
         1811   register unsigned char c, c1;
         1812 
         1813   /* A random temporary spot in PATTERN.  */
         1814   const char *p1;
         1815 
         1816   /* Points to the end of the buffer, where we should append.  */
         1817   register unsigned char *b;
         1818 
         1819   /* Keeps track of unclosed groups.  */
         1820   compile_stack_type compile_stack;
         1821 
         1822   /* Points to the current (ending) position in the pattern.  */
         1823   const char *p = pattern;
         1824   const char *pend = pattern + size;
         1825 
         1826   /* How to translate the characters in the pattern.  */
         1827   RE_TRANSLATE_TYPE translate = bufp->translate;
         1828 
         1829   /* Address of the count-byte of the most recently inserted `exactn'
         1830      command.  This makes it possible to tell if a new exact-match
         1831      character can be added to that command or if the character requires
         1832      a new `exactn' command.  */
         1833   unsigned char *pending_exact = 0;
         1834 
         1835   /* Address of start of the most recently finished expression.
         1836      This tells, e.g., postfix * where to find the start of its
         1837      operand.  Reset at the beginning of groups and alternatives.  */
         1838   unsigned char *laststart = 0;
         1839 
         1840   /* Address of beginning of regexp, or inside of last group.  */
         1841   unsigned char *begalt;
         1842 
         1843   /* Place in the uncompiled pattern (i.e., the {) to
         1844      which to go back if the interval is invalid.  */
         1845   const char *beg_interval;
         1846 
         1847   /* Address of the place where a forward jump should go to the end of
         1848      the containing expression.  Each alternative of an `or' -- except the
         1849      last -- ends with a forward jump of this sort.  */
         1850   unsigned char *fixup_alt_jump = 0;
         1851 
         1852   /* Counts open-groups as they are encountered.  Remembered for the
         1853      matching close-group on the compile stack, so the same register
         1854      number is put in the stop_memory as the start_memory.  */
         1855   regnum_t regnum = 0;
         1856 
         1857 #ifdef DEBUG
         1858   DEBUG_PRINT1 ("\nCompiling pattern: ");
         1859   if (debug)
         1860     {
         1861       unsigned debug_count;
         1862 
         1863       for (debug_count = 0; debug_count < size; debug_count++)
         1864         putchar (pattern[debug_count]);
         1865       putchar ('\n');
         1866     }
         1867 #endif /* DEBUG */
         1868 
         1869   /* Initialize the compile stack.  */
         1870   compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
         1871   if (compile_stack.stack == NULL)
         1872     return REG_ESPACE;
         1873 
         1874   compile_stack.size = INIT_COMPILE_STACK_SIZE;
         1875   compile_stack.avail = 0;
         1876 
         1877   /* Initialize the pattern buffer.  */
         1878   bufp->syntax = syntax;
         1879   bufp->fastmap_accurate = 0;
         1880   bufp->not_bol = bufp->not_eol = 0;
         1881 
         1882   /* Set `used' to zero, so that if we return an error, the pattern
         1883      printer (for debugging) will think there's no pattern.  We reset it
         1884      at the end.  */
         1885   bufp->used = 0;
         1886 
         1887   /* Always count groups, whether or not bufp->no_sub is set.  */
         1888   bufp->re_nsub = 0;
         1889 
         1890 #if !defined (emacs) && !defined (SYNTAX_TABLE)
         1891   /* Initialize the syntax table.  */
         1892    init_syntax_once ();
         1893 #endif
         1894 
         1895   if (bufp->allocated == 0)
         1896     {
         1897       if (bufp->buffer)
         1898         { /* If zero allocated, but buffer is non-null, try to realloc
         1899              enough space.  This loses if buffer's address is bogus, but
         1900              that is the user's responsibility.  */
         1901           RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
         1902         }
         1903       else
         1904         { /* Caller did not allocate a buffer.  Do it for them.  */
         1905           bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
         1906         }
         1907       if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
         1908 
         1909       bufp->allocated = INIT_BUF_SIZE;
         1910     }
         1911 
         1912   begalt = b = bufp->buffer;
         1913 
         1914   /* Loop through the uncompiled pattern until we're at the end.  */
         1915   while (p != pend)
         1916     {
         1917       PATFETCH (c);
         1918 
         1919       switch (c)
         1920         {
         1921         case '^':
         1922           {
         1923             if (   /* If at start of pattern, it's an operator.  */
         1924                    p == pattern + 1
         1925                    /* If context independent, it's an operator.  */
         1926                 || syntax & RE_CONTEXT_INDEP_ANCHORS
         1927                    /* Otherwise, depends on what's come before.  */
         1928                 || at_begline_loc_p (pattern, p, syntax))
         1929               BUF_PUSH (begline);
         1930             else
         1931               goto normal_char;
         1932           }
         1933           break;
         1934 
         1935 
         1936         case '$':
         1937           {
         1938             if (   /* If at end of pattern, it's an operator.  */
         1939                    p == pend
         1940                    /* If context independent, it's an operator.  */
         1941                 || syntax & RE_CONTEXT_INDEP_ANCHORS
         1942                    /* Otherwise, depends on what's next.  */
         1943                 || at_endline_loc_p (p, pend, syntax))
         1944                BUF_PUSH (endline);
         1945              else
         1946                goto normal_char;
         1947            }
         1948            break;
         1949 
         1950 
         1951         case '+':
         1952         case '?':
         1953           if ((syntax & RE_BK_PLUS_QM)
         1954               || (syntax & RE_LIMITED_OPS))
         1955             goto normal_char;
         1956         handle_plus:
         1957         case '*':
         1958           /* If there is no previous pattern... */
         1959           if (!laststart)
         1960             {
         1961               if (syntax & RE_CONTEXT_INVALID_OPS)
         1962                 FREE_STACK_RETURN (REG_BADRPT);
         1963               else if (!(syntax & RE_CONTEXT_INDEP_OPS))
         1964                 goto normal_char;
         1965             }
         1966 
         1967           {
         1968             /* Are we optimizing this jump?  */
         1969             boolean keep_string_p = false;
         1970 
         1971             /* 1 means zero (many) matches is allowed.  */
         1972             char zero_times_ok = 0, many_times_ok = 0;
         1973 
         1974             /* If there is a sequence of repetition chars, collapse it
         1975                down to just one (the right one).  We can't combine
         1976                interval operators with these because of, e.g., `a{2}*',
         1977                which should only match an even number of `a's.  */
         1978 
         1979             for (;;)
         1980               {
         1981                 zero_times_ok |= c != '+';
         1982                 many_times_ok |= c != '?';
         1983 
         1984                 if (p == pend)
         1985                   break;
         1986 
         1987                 PATFETCH (c);
         1988 
         1989                 if (c == '*'
         1990                     || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
         1991                   ;
         1992 
         1993                 else if (syntax & RE_BK_PLUS_QM  &&  c == '\\')
         1994                   {
         1995                     if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
         1996 
         1997                     PATFETCH (c1);
         1998                     if (!(c1 == '+' || c1 == '?'))
         1999                       {
         2000                         PATUNFETCH;
         2001                         PATUNFETCH;
         2002                         break;
         2003                       }
         2004 
         2005                     c = c1;
         2006                   }
         2007                 else
         2008                   {
         2009                     PATUNFETCH;
         2010                     break;
         2011                   }
         2012 
         2013                 /* If we get here, we found another repeat character.  */
         2014                }
         2015 
         2016             /* Star, etc. applied to an empty pattern is equivalent
         2017                to an empty pattern.  */
         2018             if (!laststart)
         2019               break;
         2020 
         2021             /* Now we know whether or not zero matches is allowed
         2022                and also whether or not two or more matches is allowed.  */
         2023             if (many_times_ok)
         2024               { /* More than one repetition is allowed, so put in at the
         2025                    end a backward relative jump from `b' to before the next
         2026                    jump we're going to put in below (which jumps from
         2027                    laststart to after this jump).
         2028 
         2029                    But if we are at the `*' in the exact sequence `.*\n',
         2030                    insert an unconditional jump backwards to the .,
         2031                    instead of the beginning of the loop.  This way we only
         2032                    push a failure point once, instead of every time
         2033                    through the loop.  */
         2034                 assert (p - 1 > pattern);
         2035 
         2036                 /* Allocate the space for the jump.  */
         2037                 GET_BUFFER_SPACE (3);
         2038 
         2039                 /* We know we are not at the first character of the pattern,
         2040                    because laststart was nonzero.  And we've already
         2041                    incremented `p', by the way, to be the character after
         2042                    the `*'.  Do we have to do something analogous here
         2043                    for null bytes, because of RE_DOT_NOT_NULL?  */
         2044                 if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
         2045                     && zero_times_ok
         2046                     && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
         2047                     && !(syntax & RE_DOT_NEWLINE))
         2048                   { /* We have .*\n.  */
         2049                     STORE_JUMP (jump, b, laststart);
         2050                     keep_string_p = true;
         2051                   }
         2052                 else
         2053                   /* Anything else.  */
         2054                   STORE_JUMP (maybe_pop_jump, b, laststart - 3);
         2055 
         2056                 /* We've added more stuff to the buffer.  */
         2057                 b += 3;
         2058               }
         2059 
         2060             /* On failure, jump from laststart to b + 3, which will be the
         2061                end of the buffer after this jump is inserted.  */
         2062             GET_BUFFER_SPACE (3);
         2063             INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
         2064                                        : on_failure_jump,
         2065                          laststart, b + 3);
         2066             pending_exact = 0;
         2067             b += 3;
         2068 
         2069             if (!zero_times_ok)
         2070               {
         2071                 /* At least one repetition is required, so insert a
         2072                    `dummy_failure_jump' before the initial
         2073                    `on_failure_jump' instruction of the loop. This
         2074                    effects a skip over that instruction the first time
         2075                    we hit that loop.  */
         2076                 GET_BUFFER_SPACE (3);
         2077                 INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
         2078                 b += 3;
         2079               }
         2080             }
         2081           break;
         2082 
         2083 
         2084         case '.':
         2085           laststart = b;
         2086           BUF_PUSH (anychar);
         2087           break;
         2088 
         2089 
         2090         case '[':
         2091           {
         2092             boolean had_char_class = false;
         2093 
         2094             if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
         2095 
         2096             /* Ensure that we have enough space to push a charset: the
         2097                opcode, the length count, and the bitset; 34 bytes in all.  */
         2098             GET_BUFFER_SPACE (34);
         2099 
         2100             laststart = b;
         2101 
         2102             /* We test `*p == '^' twice, instead of using an if
         2103                statement, so we only need one BUF_PUSH.  */
         2104             BUF_PUSH (*p == '^' ? charset_not : charset);
         2105             if (*p == '^')
         2106               p++;
         2107 
         2108             /* Remember the first position in the bracket expression.  */
         2109             p1 = p;
         2110 
         2111             /* Push the number of bytes in the bitmap.  */
         2112             BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
         2113 
         2114             /* Clear the whole map.  */
         2115             bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
         2116 
         2117             /* charset_not matches newline according to a syntax bit.  */
         2118             if ((re_opcode_t) b[-2] == charset_not
         2119                 && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
         2120               SET_LIST_BIT ('\n');
         2121 
         2122             /* Read in characters and ranges, setting map bits.  */
         2123             for (;;)
         2124               {
         2125                 if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
         2126 
         2127                 PATFETCH (c);
         2128 
         2129                 /* \ might escape characters inside [...] and [^...].  */
         2130                 if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
         2131                   {
         2132                     if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
         2133 
         2134                     PATFETCH (c1);
         2135                     SET_LIST_BIT (c1);
         2136                     continue;
         2137                   }
         2138 
         2139                 /* Could be the end of the bracket expression.  If it's
         2140                    not (i.e., when the bracket expression is `[]' so
         2141                    far), the ']' character bit gets set way below.  */
         2142                 if (c == ']' && p != p1 + 1)
         2143                   break;
         2144 
         2145                 /* Look ahead to see if it's a range when the last thing
         2146                    was a character class.  */
         2147                 if (had_char_class && c == '-' && *p != ']')
         2148                   FREE_STACK_RETURN (REG_ERANGE);
         2149 
         2150                 /* Look ahead to see if it's a range when the last thing
         2151                    was a character: if this is a hyphen not at the
         2152                    beginning or the end of a list, then it's the range
         2153                    operator.  */
         2154                 if (c == '-'
         2155                     && !(p - 2 >= pattern && p[-2] == '[')
         2156                     && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
         2157                     && *p != ']')
         2158                   {
         2159                     reg_errcode_t ret
         2160                       = compile_range (&p, pend, translate, syntax, b);
         2161                     if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
         2162                   }
         2163 
         2164                 else if (p[0] == '-' && p[1] != ']')
         2165                   { /* This handles ranges made up of characters only.  */
         2166                     reg_errcode_t ret;
         2167 
         2168                     /* Move past the `-'.  */
         2169                     PATFETCH (c1);
         2170 
         2171                     ret = compile_range (&p, pend, translate, syntax, b);
         2172                     if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
         2173                   }
         2174 
         2175                 /* See if we're at the beginning of a possible character
         2176                    class.  */
         2177 
         2178                 else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
         2179                   { /* Leave room for the null.  */
         2180                     char str[CHAR_CLASS_MAX_LENGTH + 1];
         2181 
         2182                     PATFETCH (c);
         2183                     c1 = 0;
         2184 
         2185                     /* If pattern is `[[:'.  */
         2186                     if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
         2187 
         2188                     for (;;)
         2189                       {
         2190                         PATFETCH (c);
         2191                         if (c == ':' || c == ']' || p == pend
         2192                             || c1 == CHAR_CLASS_MAX_LENGTH)
         2193                           break;
         2194                         str[c1++] = c;
         2195                       }
         2196                     str[c1] = '\0';
         2197 
         2198                     /* If isn't a word bracketed by `[:' and:`]':
         2199                        undo the ending character, the letters, and leave
         2200                        the leading `:' and `[' (but set bits for them).  */
         2201                     if (c == ':' && *p == ']')
         2202                       {
         2203 #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
         2204                         boolean is_lower = STREQ (str, "lower");
         2205                         boolean is_upper = STREQ (str, "upper");
         2206                         wctype_t wt;
         2207                         int ch;
         2208 
         2209                         wt = wctype (str);
         2210                         if (wt == 0)
         2211                           FREE_STACK_RETURN (REG_ECTYPE);
         2212 
         2213                         /* Throw away the ] at the end of the character
         2214                            class.  */
         2215                         PATFETCH (c);
         2216 
         2217                         if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
         2218 
         2219                         for (ch = 0; ch < 1 << BYTEWIDTH; ++ch)
         2220                           {
         2221                             if (iswctype (btowc (ch), wt))
         2222                               SET_LIST_BIT (ch);
         2223 
         2224                             if (translate && (is_upper || is_lower)
         2225                                 && (ISUPPER (ch) || ISLOWER (ch)))
         2226                               SET_LIST_BIT (ch);
         2227                           }
         2228 
         2229                         had_char_class = true;
         2230 #else
         2231                         int ch;
         2232                         boolean is_alnum = STREQ (str, "alnum");
         2233                         boolean is_alpha = STREQ (str, "alpha");
         2234                         boolean is_blank = STREQ (str, "blank");
         2235                         boolean is_cntrl = STREQ (str, "cntrl");
         2236                         boolean is_digit = STREQ (str, "digit");
         2237                         boolean is_graph = STREQ (str, "graph");
         2238                         boolean is_lower = STREQ (str, "lower");
         2239                         boolean is_print = STREQ (str, "print");
         2240                         boolean is_punct = STREQ (str, "punct");
         2241                         boolean is_space = STREQ (str, "space");
         2242                         boolean is_upper = STREQ (str, "upper");
         2243                         boolean is_xdigit = STREQ (str, "xdigit");
         2244 
         2245                         if (!IS_CHAR_CLASS (str))
         2246                           FREE_STACK_RETURN (REG_ECTYPE);
         2247 
         2248                         /* Throw away the ] at the end of the character
         2249                            class.  */
         2250                         PATFETCH (c);
         2251 
         2252                         if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
         2253 
         2254                         for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
         2255                           {
         2256                             /* This was split into 3 if's to
         2257                                avoid an arbitrary limit in some compiler.  */
         2258                             if (   (is_alnum  && ISALNUM (ch))
         2259                                 || (is_alpha  && ISALPHA (ch))
         2260                                 || (is_blank  && ISBLANK (ch))
         2261                                 || (is_cntrl  && ISCNTRL (ch)))
         2262                               SET_LIST_BIT (ch);
         2263                             if (   (is_digit  && ISDIGIT (ch))
         2264                                 || (is_graph  && ISGRAPH (ch))
         2265                                 || (is_lower  && ISLOWER (ch))
         2266                                 || (is_print  && ISPRINT (ch)))
         2267                               SET_LIST_BIT (ch);
         2268                             if (   (is_punct  && ISPUNCT (ch))
         2269                                 || (is_space  && ISSPACE (ch))
         2270                                 || (is_upper  && ISUPPER (ch))
         2271                                 || (is_xdigit && ISXDIGIT (ch)))
         2272                               SET_LIST_BIT (ch);
         2273                             if (   translate && (is_upper || is_lower)
         2274                                 && (ISUPPER (ch) || ISLOWER (ch)))
         2275                               SET_LIST_BIT (ch);
         2276                           }
         2277                         had_char_class = true;
         2278 #endif        /* libc || wctype.h */
         2279                       }
         2280                     else
         2281                       {
         2282                         c1++;
         2283                         while (c1--)
         2284                           PATUNFETCH;
         2285                         SET_LIST_BIT ('[');
         2286                         SET_LIST_BIT (':');
         2287                         had_char_class = false;
         2288                       }
         2289                   }
         2290                 else
         2291                   {
         2292                     had_char_class = false;
         2293                     SET_LIST_BIT (c);
         2294                   }
         2295               }
         2296 
         2297             /* Discard any (non)matching list bytes that are all 0 at the
         2298                end of the map.  Decrease the map-length byte too.  */
         2299             while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
         2300               b[-1]--;
         2301             b += b[-1];
         2302           }
         2303           break;
         2304 
         2305 
         2306         case '(':
         2307           if (syntax & RE_NO_BK_PARENS)
         2308             goto handle_open;
         2309           else
         2310             goto normal_char;
         2311 
         2312 
         2313         case ')':
         2314           if (syntax & RE_NO_BK_PARENS)
         2315             goto handle_close;
         2316           else
         2317             goto normal_char;
         2318 
         2319 
         2320         case '\n':
         2321           if (syntax & RE_NEWLINE_ALT)
         2322             goto handle_alt;
         2323           else
         2324             goto normal_char;
         2325 
         2326 
         2327         case '|':
         2328           if (syntax & RE_NO_BK_VBAR)
         2329             goto handle_alt;
         2330           else
         2331             goto normal_char;
         2332 
         2333 
         2334         case '{':
         2335            if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
         2336              goto handle_interval;
         2337            else
         2338              goto normal_char;
         2339 
         2340 
         2341         case '\\':
         2342           if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
         2343 
         2344           /* Do not translate the character after the \, so that we can
         2345              distinguish, e.g., \B from \b, even if we normally would
         2346              translate, e.g., B to b.  */
         2347           PATFETCH_RAW (c);
         2348 
         2349           switch (c)
         2350             {
         2351             case '(':
         2352               if (syntax & RE_NO_BK_PARENS)
         2353                 goto normal_backslash;
         2354 
         2355             handle_open:
         2356               bufp->re_nsub++;
         2357               regnum++;
         2358 
         2359               if (COMPILE_STACK_FULL)
         2360                 {
         2361                   RETALLOC (compile_stack.stack, compile_stack.size << 1,
         2362                             compile_stack_elt_t);
         2363                   if (compile_stack.stack == NULL) return REG_ESPACE;
         2364 
         2365                   compile_stack.size <<= 1;
         2366                 }
         2367 
         2368               /* These are the values to restore when we hit end of this
         2369                  group.  They are all relative offsets, so that if the
         2370                  whole pattern moves because of realloc, they will still
         2371                  be valid.  */
         2372               COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
         2373               COMPILE_STACK_TOP.fixup_alt_jump
         2374                 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
         2375               COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
         2376               COMPILE_STACK_TOP.regnum = regnum;
         2377 
         2378               /* We will eventually replace the 0 with the number of
         2379                  groups inner to this one.  But do not push a
         2380                  start_memory for groups beyond the last one we can
         2381                  represent in the compiled pattern.  */
         2382               if (regnum <= MAX_REGNUM)
         2383                 {
         2384                   COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
         2385                   BUF_PUSH_3 (start_memory, regnum, 0);
         2386                 }
         2387 
         2388               compile_stack.avail++;
         2389 
         2390               fixup_alt_jump = 0;
         2391               laststart = 0;
         2392               begalt = b;
         2393               /* If we've reached MAX_REGNUM groups, then this open
         2394                  won't actually generate any code, so we'll have to
         2395                  clear pending_exact explicitly.  */
         2396               pending_exact = 0;
         2397               break;
         2398 
         2399 
         2400             case ')':
         2401               if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
         2402 
         2403               if (COMPILE_STACK_EMPTY) {
         2404                 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
         2405                   goto normal_backslash;
         2406                 else
         2407                   FREE_STACK_RETURN (REG_ERPAREN);
         2408               }
         2409 
         2410             handle_close:
         2411               if (fixup_alt_jump)
         2412                 { /* Push a dummy failure point at the end of the
         2413                      alternative for a possible future
         2414                      `pop_failure_jump' to pop.  See comments at
         2415                      `push_dummy_failure' in `re_match_2'.  */
         2416                   BUF_PUSH (push_dummy_failure);
         2417 
         2418                   /* We allocated space for this jump when we assigned
         2419                      to `fixup_alt_jump', in the `handle_alt' case below.  */
         2420                   STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
         2421                 }
         2422 
         2423               /* See similar code for backslashed left paren above.  */
         2424               if (COMPILE_STACK_EMPTY) {
         2425                 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
         2426                   goto normal_char;
         2427                 else
         2428                   FREE_STACK_RETURN (REG_ERPAREN);
         2429               }
         2430 
         2431               /* Since we just checked for an empty stack above, this
         2432                  ``can't happen''.  */
         2433               assert (compile_stack.avail != 0);
         2434               {
         2435                 /* We don't just want to restore into `regnum', because
         2436                    later groups should continue to be numbered higher,
         2437                    as in `(ab)c(de)' -- the second group is #2.  */
         2438                 regnum_t this_group_regnum;
         2439 
         2440                 compile_stack.avail--;
         2441                 begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
         2442                 fixup_alt_jump
         2443                   = COMPILE_STACK_TOP.fixup_alt_jump
         2444                     ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
         2445                     : 0;
         2446                 laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
         2447                 this_group_regnum = COMPILE_STACK_TOP.regnum;
         2448                 /* If we've reached MAX_REGNUM groups, then this open
         2449                    won't actually generate any code, so we'll have to
         2450                    clear pending_exact explicitly.  */
         2451                 pending_exact = 0;
         2452 
         2453                 /* We're at the end of the group, so now we know how many
         2454                    groups were inside this one.  */
         2455                 if (this_group_regnum <= MAX_REGNUM)
         2456                   {
         2457                     unsigned char *inner_group_loc
         2458                       = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;
         2459 
         2460                     *inner_group_loc = regnum - this_group_regnum;
         2461                     BUF_PUSH_3 (stop_memory, this_group_regnum,
         2462                                 regnum - this_group_regnum);
         2463                   }
         2464               }
         2465               break;
         2466 
         2467 
         2468             case '|':                                        /* `\|'.  */
         2469               if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
         2470                 goto normal_backslash;
         2471             handle_alt:
         2472               if (syntax & RE_LIMITED_OPS)
         2473                 goto normal_char;
         2474 
         2475               /* Insert before the previous alternative a jump which
         2476                  jumps to this alternative if the former fails.  */
         2477               GET_BUFFER_SPACE (3);
         2478               INSERT_JUMP (on_failure_jump, begalt, b + 6);
         2479               pending_exact = 0;
         2480               b += 3;
         2481 
         2482               /* The alternative before this one has a jump after it
         2483                  which gets executed if it gets matched.  Adjust that
         2484                  jump so it will jump to this alternative's analogous
         2485                  jump (put in below, which in turn will jump to the next
         2486                  (if any) alternative's such jump, etc.).  The last such
         2487                  jump jumps to the correct final destination.  A picture:
         2488                           _____ _____
         2489                           |   | |   |
         2490                           |   v |   v
         2491                          a | b   | c
         2492 
         2493                  If we are at `b', then fixup_alt_jump right now points to a
         2494                  three-byte space after `a'.  We'll put in the jump, set
         2495                  fixup_alt_jump to right after `b', and leave behind three
         2496                  bytes which we'll fill in when we get to after `c'.  */
         2497 
         2498               if (fixup_alt_jump)
         2499                 STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
         2500 
         2501               /* Mark and leave space for a jump after this alternative,
         2502                  to be filled in later either by next alternative or
         2503                  when know we're at the end of a series of alternatives.  */
         2504               fixup_alt_jump = b;
         2505               GET_BUFFER_SPACE (3);
         2506               b += 3;
         2507 
         2508               laststart = 0;
         2509               begalt = b;
         2510               break;
         2511 
         2512 
         2513             case '{':
         2514               /* If \{ is a literal.  */
         2515               if (!(syntax & RE_INTERVALS)
         2516                      /* If we're at `\{' and it's not the open-interval
         2517                         operator.  */
         2518                   || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
         2519                   || (p - 2 == pattern  &&  p == pend))
         2520                 goto normal_backslash;
         2521 
         2522             handle_interval:
         2523               {
         2524                 /* If got here, then the syntax allows intervals.  */
         2525 
         2526                 /* At least (most) this many matches must be made.  */
         2527                 int lower_bound = -1, upper_bound = -1;
         2528 
         2529                 beg_interval = p - 1;
         2530 
         2531                 if (p == pend)
         2532                   {
         2533                     if (syntax & RE_NO_BK_BRACES)
         2534                       goto unfetch_interval;
         2535                     else
         2536                       FREE_STACK_RETURN (REG_EBRACE);
         2537                   }
         2538 
         2539                 GET_UNSIGNED_NUMBER (lower_bound);
         2540 
         2541                 if (c == ',')
         2542                   {
         2543                     GET_UNSIGNED_NUMBER (upper_bound);
         2544                     if (upper_bound < 0) upper_bound = RE_DUP_MAX;
         2545                   }
         2546                 else
         2547                   /* Interval such as `{1}' => match exactly once. */
         2548                   upper_bound = lower_bound;
         2549 
         2550                 if (lower_bound < 0 || upper_bound > RE_DUP_MAX
         2551                     || lower_bound > upper_bound)
         2552                   {
         2553                     if (syntax & RE_NO_BK_BRACES)
         2554                       goto unfetch_interval;
         2555                     else
         2556                       FREE_STACK_RETURN (REG_BADBR);
         2557                   }
         2558 
         2559                 if (!(syntax & RE_NO_BK_BRACES))
         2560                   {
         2561                     if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);
         2562 
         2563                     PATFETCH (c);
         2564                   }
         2565 
         2566                 if (c != '}')
         2567                   {
         2568                     if (syntax & RE_NO_BK_BRACES)
         2569                       goto unfetch_interval;
         2570                     else
         2571                       FREE_STACK_RETURN (REG_BADBR);
         2572                   }
         2573 
         2574                 /* We just parsed a valid interval.  */
         2575 
         2576                 /* If it's invalid to have no preceding re.  */
         2577                 if (!laststart)
         2578                   {
         2579                     if (syntax & RE_CONTEXT_INVALID_OPS)
         2580                       FREE_STACK_RETURN (REG_BADRPT);
         2581                     else if (syntax & RE_CONTEXT_INDEP_OPS)
         2582                       laststart = b;
         2583                     else
         2584                       goto unfetch_interval;
         2585                   }
         2586 
         2587                 /* If the upper bound is zero, don't want to succeed at
         2588                    all; jump from `laststart' to `b + 3', which will be
         2589                    the end of the buffer after we insert the jump.  */
         2590                  if (upper_bound == 0)
         2591                    {
         2592                      GET_BUFFER_SPACE (3);
         2593                      INSERT_JUMP (jump, laststart, b + 3);
         2594                      b += 3;
         2595                    }
         2596 
         2597                  /* Otherwise, we have a nontrivial interval.  When
         2598                     we're all done, the pattern will look like:
         2599                       set_number_at <jump count> <upper bound>
         2600                       set_number_at <succeed_n count> <lower bound>
         2601                       succeed_n <after jump addr> <succeed_n count>
         2602                       <body of loop>
         2603                       jump_n <succeed_n addr> <jump count>
         2604                     (The upper bound and `jump_n' are omitted if
         2605                     `upper_bound' is 1, though.)  */
         2606                  else
         2607                    { /* If the upper bound is > 1, we need to insert
         2608                         more at the end of the loop.  */
         2609                      unsigned nbytes = 10 + (upper_bound > 1) * 10;
         2610 
         2611                      GET_BUFFER_SPACE (nbytes);
         2612 
         2613                      /* Initialize lower bound of the `succeed_n', even
         2614                         though it will be set during matching by its
         2615                         attendant `set_number_at' (inserted next),
         2616                         because `re_compile_fastmap' needs to know.
         2617                         Jump to the `jump_n' we might insert below.  */
         2618                      INSERT_JUMP2 (succeed_n, laststart,
         2619                                    b + 5 + (upper_bound > 1) * 5,
         2620                                    lower_bound);
         2621                      b += 5;
         2622 
         2623                      /* Code to initialize the lower bound.  Insert
         2624                         before the `succeed_n'.  The `5' is the last two
         2625                         bytes of this `set_number_at', plus 3 bytes of
         2626                         the following `succeed_n'.  */
         2627                      insert_op2 (set_number_at, laststart, 5, lower_bound, b);
         2628                      b += 5;
         2629 
         2630                      if (upper_bound > 1)
         2631                        { /* More than one repetition is allowed, so
         2632                             append a backward jump to the `succeed_n'
         2633                             that starts this interval.
         2634 
         2635                             When we've reached this during matching,
         2636                             we'll have matched the interval once, so
         2637                             jump back only `upper_bound - 1' times.  */
         2638                          STORE_JUMP2 (jump_n, b, laststart + 5,
         2639                                       upper_bound - 1);
         2640                          b += 5;
         2641 
         2642                          /* The location we want to set is the second
         2643                             parameter of the `jump_n'; that is `b-2' as
         2644                             an absolute address.  `laststart' will be
         2645                             the `set_number_at' we're about to insert;
         2646                             `laststart+3' the number to set, the source
         2647                             for the relative address.  But we are
         2648                             inserting into the middle of the pattern --
         2649                             so everything is getting moved up by 5.
         2650                             Conclusion: (b - 2) - (laststart + 3) + 5,
         2651                             i.e., b - laststart.
         2652 
         2653                             We insert this at the beginning of the loop
         2654                             so that if we fail during matching, we'll
         2655                             reinitialize the bounds.  */
         2656                          insert_op2 (set_number_at, laststart, b - laststart,
         2657                                      upper_bound - 1, b);
         2658                          b += 5;
         2659                        }
         2660                    }
         2661                 pending_exact = 0;
         2662                 beg_interval = NULL;
         2663               }
         2664               break;
         2665 
         2666             unfetch_interval:
         2667               /* If an invalid interval, match the characters as literals.  */
         2668                assert (beg_interval);
         2669                p = beg_interval;
         2670                beg_interval = NULL;
         2671 
         2672                /* normal_char and normal_backslash need `c'.  */
         2673                PATFETCH (c);
         2674 
         2675                if (!(syntax & RE_NO_BK_BRACES))
         2676                  {
         2677                    if (p > pattern  &&  p[-1] == '\\')
         2678                      goto normal_backslash;
         2679                  }
         2680                goto normal_char;
         2681 
         2682 #ifdef emacs
         2683             /* There is no way to specify the before_dot and after_dot
         2684                operators.  rms says this is ok.  --karl  */
         2685             case '=':
         2686               BUF_PUSH (at_dot);
         2687               break;
         2688 
         2689             case 's':
         2690               laststart = b;
         2691               PATFETCH (c);
         2692               BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
         2693               break;
         2694 
         2695             case 'S':
         2696               laststart = b;
         2697               PATFETCH (c);
         2698               BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
         2699               break;
         2700 #endif /* emacs */
         2701 
         2702 
         2703             case 'w':
         2704               if (re_syntax_options & RE_NO_GNU_OPS)
         2705                 goto normal_char;
         2706               laststart = b;
         2707               BUF_PUSH (wordchar);
         2708               break;
         2709 
         2710 
         2711             case 'W':
         2712               if (re_syntax_options & RE_NO_GNU_OPS)
         2713                 goto normal_char;
         2714               laststart = b;
         2715               BUF_PUSH (notwordchar);
         2716               break;
         2717 
         2718 
         2719             case '<':
         2720               if (re_syntax_options & RE_NO_GNU_OPS)
         2721                 goto normal_char;
         2722               BUF_PUSH (wordbeg);
         2723               break;
         2724 
         2725             case '>':
         2726               if (re_syntax_options & RE_NO_GNU_OPS)
         2727                 goto normal_char;
         2728               BUF_PUSH (wordend);
         2729               break;
         2730 
         2731             case 'b':
         2732               if (re_syntax_options & RE_NO_GNU_OPS)
         2733                 goto normal_char;
         2734               BUF_PUSH (wordbound);
         2735               break;
         2736 
         2737             case 'B':
         2738               if (re_syntax_options & RE_NO_GNU_OPS)
         2739                 goto normal_char;
         2740               BUF_PUSH (notwordbound);
         2741               break;
         2742 
         2743             case '`':
         2744               if (re_syntax_options & RE_NO_GNU_OPS)
         2745                 goto normal_char;
         2746               BUF_PUSH (begbuf);
         2747               break;
         2748 
         2749             case '\'':
         2750               if (re_syntax_options & RE_NO_GNU_OPS)
         2751                 goto normal_char;
         2752               BUF_PUSH (endbuf);
         2753               break;
         2754 
         2755             case '1': case '2': case '3': case '4': case '5':
         2756             case '6': case '7': case '8': case '9':
         2757               if (syntax & RE_NO_BK_REFS)
         2758                 goto normal_char;
         2759 
         2760               c1 = c - '0';
         2761 
         2762               if (c1 > regnum)
         2763                 FREE_STACK_RETURN (REG_ESUBREG);
         2764 
         2765               /* Can't back reference to a subexpression if inside of it.  */
         2766               if (group_in_compile_stack (compile_stack, (regnum_t) c1))
         2767                 goto normal_char;
         2768 
         2769               laststart = b;
         2770               BUF_PUSH_2 (duplicate, c1);
         2771               break;
         2772 
         2773 
         2774             case '+':
         2775             case '?':
         2776               if (syntax & RE_BK_PLUS_QM)
         2777                 goto handle_plus;
         2778               else
         2779                 goto normal_backslash;
         2780 
         2781             default:
         2782             normal_backslash:
         2783               /* You might think it would be useful for \ to mean
         2784                  not to translate; but if we don't translate it
         2785                  it will never match anything.  */
         2786               c = TRANSLATE (c);
         2787               goto normal_char;
         2788             }
         2789           break;
         2790 
         2791 
         2792         default:
         2793         /* Expects the character in `c'.  */
         2794         normal_char:
         2795               /* If no exactn currently being built.  */
         2796           if (!pending_exact
         2797 
         2798               /* If last exactn not at current position.  */
         2799               || pending_exact + *pending_exact + 1 != b
         2800 
         2801               /* We have only one byte following the exactn for the count.  */
         2802               || *pending_exact == (1 << BYTEWIDTH) - 1
         2803 
         2804               /* If followed by a repetition operator.  */
         2805               || *p == '*' || *p == '^'
         2806               || ((syntax & RE_BK_PLUS_QM)
         2807                   ? *p == '\\' && (p[1] == '+' || p[1] == '?')
         2808                   : (*p == '+' || *p == '?'))
         2809               || ((syntax & RE_INTERVALS)
         2810                   && ((syntax & RE_NO_BK_BRACES)
         2811                       ? *p == '{'
         2812                       : (p[0] == '\\' && p[1] == '{'))))
         2813             {
         2814               /* Start building a new exactn.  */
         2815 
         2816               laststart = b;
         2817 
         2818               BUF_PUSH_2 (exactn, 0);
         2819               pending_exact = b - 1;
         2820             }
         2821 
         2822           BUF_PUSH (c);
         2823           (*pending_exact)++;
         2824           break;
         2825         } /* switch (c) */
         2826     } /* while p != pend */
         2827 
         2828 
         2829   /* Through the pattern now.  */
         2830 
         2831   if (fixup_alt_jump)
         2832     STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
         2833 
         2834   if (!COMPILE_STACK_EMPTY)
         2835     FREE_STACK_RETURN (REG_EPAREN);
         2836 
         2837   /* If we don't want backtracking, force success
         2838      the first time we reach the end of the compiled pattern.  */
         2839   if (syntax & RE_NO_POSIX_BACKTRACKING)
         2840     BUF_PUSH (succeed);
         2841 
         2842   free (compile_stack.stack);
         2843 
         2844   /* We have succeeded; set the length of the buffer.  */
         2845   bufp->used = b - bufp->buffer;
         2846 
         2847 #ifdef DEBUG
         2848   if (debug)
         2849     {
         2850       DEBUG_PRINT1 ("\nCompiled pattern: \n");
         2851       print_compiled_pattern (bufp);
         2852     }
         2853 #endif /* DEBUG */
         2854 
         2855 #ifndef MATCH_MAY_ALLOCATE
         2856   /* Initialize the failure stack to the largest possible stack.  This
         2857      isn't necessary unless we're trying to avoid calling alloca in
         2858      the search and match routines.  */
         2859   {
         2860     int num_regs = bufp->re_nsub + 1;
         2861 
         2862     /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
         2863        is strictly greater than re_max_failures, the largest possible stack
         2864        is 2 * re_max_failures failure points.  */
         2865     if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
         2866       {
         2867         fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
         2868 
         2869 #ifdef emacs
         2870         if (! fail_stack.stack)
         2871           fail_stack.stack
         2872             = (fail_stack_elt_t *) xmalloc (fail_stack.size
         2873                                             * sizeof (fail_stack_elt_t));
         2874         else
         2875           fail_stack.stack
         2876             = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
         2877                                              (fail_stack.size
         2878                                               * sizeof (fail_stack_elt_t)));
         2879 #else /* not emacs */
         2880         if (! fail_stack.stack)
         2881           fail_stack.stack
         2882             = (fail_stack_elt_t *) malloc (fail_stack.size
         2883                                            * sizeof (fail_stack_elt_t));
         2884         else
         2885           fail_stack.stack
         2886             = (fail_stack_elt_t *) realloc (fail_stack.stack,
         2887                                             (fail_stack.size
         2888                                              * sizeof (fail_stack_elt_t)));
         2889 #endif /* not emacs */
         2890       }
         2891 
         2892     regex_grow_registers (num_regs);
         2893   }
         2894 #endif /* not MATCH_MAY_ALLOCATE */
         2895 
         2896   return REG_NOERROR;
         2897 } /* regex_compile */
         2898 
         2899 /* Subroutines for `regex_compile'.  */
         2900 
         2901 /* Store OP at LOC followed by two-byte integer parameter ARG.  */
         2902 
         2903 static void
         2904 store_op1 (op, loc, arg)
         2905     re_opcode_t op;
         2906     unsigned char *loc;
         2907     int arg;
         2908 {
         2909   *loc = (unsigned char) op;
         2910   STORE_NUMBER (loc + 1, arg);
         2911 }
         2912 
         2913 
         2914 /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2.  */
         2915 
         2916 static void
         2917 store_op2 (op, loc, arg1, arg2)
         2918     re_opcode_t op;
         2919     unsigned char *loc;
         2920     int arg1, arg2;
         2921 {
         2922   *loc = (unsigned char) op;
         2923   STORE_NUMBER (loc + 1, arg1);
         2924   STORE_NUMBER (loc + 3, arg2);
         2925 }
         2926 
         2927 
         2928 /* Copy the bytes from LOC to END to open up three bytes of space at LOC
         2929    for OP followed by two-byte integer parameter ARG.  */
         2930 
         2931 static void
         2932 insert_op1 (op, loc, arg, end)
         2933     re_opcode_t op;
         2934     unsigned char *loc;
         2935     int arg;
         2936     unsigned char *end;
         2937 {
         2938   register unsigned char *pfrom = end;
         2939   register unsigned char *pto = end + 3;
         2940 
         2941   while (pfrom != loc)
         2942     *--pto = *--pfrom;
         2943 
         2944   store_op1 (op, loc, arg);
         2945 }
         2946 
         2947 
         2948 /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2.  */
         2949 
         2950 static void
         2951 insert_op2 (op, loc, arg1, arg2, end)
         2952     re_opcode_t op;
         2953     unsigned char *loc;
         2954     int arg1, arg2;
         2955     unsigned char *end;
         2956 {
         2957   register unsigned char *pfrom = end;
         2958   register unsigned char *pto = end + 5;
         2959 
         2960   while (pfrom != loc)
         2961     *--pto = *--pfrom;
         2962 
         2963   store_op2 (op, loc, arg1, arg2);
         2964 }
         2965 
         2966 
         2967 /* P points to just after a ^ in PATTERN.  Return true if that ^ comes
         2968    after an alternative or a begin-subexpression.  We assume there is at
         2969    least one character before the ^.  */
         2970 
         2971 static boolean
         2972 at_begline_loc_p (pattern, p, syntax)
         2973     const char *pattern, *p;
         2974     reg_syntax_t syntax;
         2975 {
         2976   const char *prev = p - 2;
         2977   boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
         2978 
         2979   return
         2980        /* After a subexpression?  */
         2981        (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
         2982        /* After an alternative?  */
         2983     || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
         2984 }
         2985 
         2986 
         2987 /* The dual of at_begline_loc_p.  This one is for $.  We assume there is
         2988    at least one character after the $, i.e., `P < PEND'.  */
         2989 
         2990 static boolean
         2991 at_endline_loc_p (p, pend, syntax)
         2992     const char *p, *pend;
         2993     reg_syntax_t syntax;
         2994 {
         2995   const char *next = p;
         2996   boolean next_backslash = *next == '\\';
         2997   const char *next_next = p + 1 < pend ? p + 1 : 0;
         2998 
         2999   return
         3000        /* Before a subexpression?  */
         3001        (syntax & RE_NO_BK_PARENS ? *next == ')'
         3002         : next_backslash && next_next && *next_next == ')')
         3003        /* Before an alternative?  */
         3004     || (syntax & RE_NO_BK_VBAR ? *next == '|'
         3005         : next_backslash && next_next && *next_next == '|');
         3006 }
         3007 
         3008 
         3009 /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
         3010    false if it's not.  */
         3011 
         3012 static boolean
         3013 group_in_compile_stack (compile_stack, regnum)
         3014     compile_stack_type compile_stack;
         3015     regnum_t regnum;
         3016 {
         3017   int this_element;
         3018 
         3019   for (this_element = compile_stack.avail - 1;
         3020        this_element >= 0;
         3021        this_element--)
         3022     if (compile_stack.stack[this_element].regnum == regnum)
         3023       return true;
         3024 
         3025   return false;
         3026 }
         3027 
         3028 
         3029 /* Read the ending character of a range (in a bracket expression) from the
         3030    uncompiled pattern *P_PTR (which ends at PEND).  We assume the
         3031    starting character is in `P[-2]'.  (`P[-1]' is the character `-'.)
         3032    Then we set the translation of all bits between the starting and
         3033    ending characters (inclusive) in the compiled pattern B.
         3034 
         3035    Return an error code.
         3036 
         3037    We use these short variable names so we can use the same macros as
         3038    `regex_compile' itself.  */
         3039 
         3040 static reg_errcode_t
         3041 compile_range (p_ptr, pend, translate, syntax, b)
         3042     const char **p_ptr, *pend;
         3043     RE_TRANSLATE_TYPE translate;
         3044     reg_syntax_t syntax;
         3045     unsigned char *b;
         3046 {
         3047   unsigned this_char;
         3048 
         3049   const char *p = *p_ptr;
         3050   unsigned int range_start, range_end;
         3051 
         3052   if (p == pend)
         3053     return REG_ERANGE;
         3054 
         3055   /* Even though the pattern is a signed `char *', we need to fetch
         3056      with unsigned char *'s; if the high bit of the pattern character
         3057      is set, the range endpoints will be negative if we fetch using a
         3058      signed char *.
         3059 
         3060      We also want to fetch the endpoints without translating them; the
         3061      appropriate translation is done in the bit-setting loop below.  */
         3062   /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *.  */
         3063   range_start = ((const unsigned char *) p)[-2];
         3064   range_end   = ((const unsigned char *) p)[0];
         3065 
         3066   /* Have to increment the pointer into the pattern string, so the
         3067      caller isn't still at the ending character.  */
         3068   (*p_ptr)++;
         3069 
         3070   /* If the start is after the end, the range is empty.  */
         3071   if (range_start > range_end)
         3072     return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
         3073 
         3074   /* Here we see why `this_char' has to be larger than an `unsigned
         3075      char' -- the range is inclusive, so if `range_end' == 0xff
         3076      (assuming 8-bit characters), we would otherwise go into an infinite
         3077      loop, since all characters <= 0xff.  */
         3078   for (this_char = range_start; this_char <= range_end; this_char++)
         3079     {
         3080       SET_LIST_BIT (TRANSLATE (this_char));
         3081     }
         3082 
         3083   return REG_NOERROR;
         3084 }
         3085 
         3086 /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
         3087    BUFP.  A fastmap records which of the (1 << BYTEWIDTH) possible
         3088    characters can start a string that matches the pattern.  This fastmap
         3089    is used by re_search to skip quickly over impossible starting points.
         3090 
         3091    The caller must supply the address of a (1 << BYTEWIDTH)-byte data
         3092    area as BUFP->fastmap.
         3093 
         3094    We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
         3095    the pattern buffer.
         3096 
         3097    Returns 0 if we succeed, -2 if an internal error.   */
         3098 
         3099 int
         3100 re_compile_fastmap (bufp)
         3101      struct re_pattern_buffer *bufp;
         3102 {
         3103   int j, k;
         3104 #ifdef MATCH_MAY_ALLOCATE
         3105   fail_stack_type fail_stack;
         3106 #endif
         3107 #ifndef REGEX_MALLOC
         3108   char *destination;
         3109 #endif
         3110   /* We don't push any register information onto the failure stack.  */
         3111   register char *fastmap = bufp->fastmap;
         3112   unsigned char *pattern = bufp->buffer;
         3113   unsigned char *p = pattern;
         3114   register unsigned char *pend = pattern + bufp->used;
         3115 
         3116 #ifdef REL_ALLOC
         3117   /* This holds the pointer to the failure stack, when
         3118      it is allocated relocatably.  */
         3119   fail_stack_elt_t *failure_stack_ptr;
         3120 #endif
         3121 
         3122   /* Assume that each path through the pattern can be null until
         3123      proven otherwise.  We set this false at the bottom of switch
         3124      statement, to which we get only if a particular path doesn't
         3125      match the empty string.  */
         3126   boolean path_can_be_null = true;
         3127 
         3128   /* We aren't doing a `succeed_n' to begin with.  */
         3129   boolean succeed_n_p = false;
         3130 
         3131   assert (fastmap != NULL && p != NULL);
         3132 
         3133   INIT_FAIL_STACK ();
         3134   bzero (fastmap, 1 << BYTEWIDTH);  /* Assume nothing's valid.  */
         3135   bufp->fastmap_accurate = 1;            /* It will be when we're done.  */
         3136   bufp->can_be_null = 0;
         3137 
         3138   while (1)
         3139     {
         3140       if (p == pend || *p == succeed)
         3141         {
         3142           /* We have reached the (effective) end of pattern.  */
         3143           if (!FAIL_STACK_EMPTY ())
         3144             {
         3145               bufp->can_be_null |= path_can_be_null;
         3146 
         3147               /* Reset for next path.  */
         3148               path_can_be_null = true;
         3149 
         3150               p = fail_stack.stack[--fail_stack.avail].pointer;
         3151 
         3152               continue;
         3153             }
         3154           else
         3155             break;
         3156         }
         3157 
         3158       /* We should never be about to go beyond the end of the pattern.  */
         3159       assert (p < pend);
         3160 
         3161       switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
         3162         {
         3163 
         3164         /* I guess the idea here is to simply not bother with a fastmap
         3165            if a backreference is used, since it's too hard to figure out
         3166            the fastmap for the corresponding group.  Setting
         3167            `can_be_null' stops `re_search_2' from using the fastmap, so
         3168            that is all we do.  */
         3169         case duplicate:
         3170           bufp->can_be_null = 1;
         3171           goto done;
         3172 
         3173 
         3174       /* Following are the cases which match a character.  These end
         3175          with `break'.  */
         3176 
         3177         case exactn:
         3178           fastmap[p[1]] = 1;
         3179           break;
         3180 
         3181 
         3182         case charset:
         3183           for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
         3184             if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
         3185               fastmap[j] = 1;
         3186           break;
         3187 
         3188 
         3189         case charset_not:
         3190           /* Chars beyond end of map must be allowed.  */
         3191           for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
         3192             fastmap[j] = 1;
         3193 
         3194           for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
         3195             if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
         3196               fastmap[j] = 1;
         3197           break;
         3198 
         3199 
         3200         case wordchar:
         3201           for (j = 0; j < (1 << BYTEWIDTH); j++)
         3202             if (SYNTAX (j) == Sword)
         3203               fastmap[j] = 1;
         3204           break;
         3205 
         3206 
         3207         case notwordchar:
         3208           for (j = 0; j < (1 << BYTEWIDTH); j++)
         3209             if (SYNTAX (j) != Sword)
         3210               fastmap[j] = 1;
         3211           break;
         3212 
         3213 
         3214         case anychar:
         3215           {
         3216             int fastmap_newline = fastmap['\n'];
         3217 
         3218             /* `.' matches anything ...  */
         3219             for (j = 0; j < (1 << BYTEWIDTH); j++)
         3220               fastmap[j] = 1;
         3221 
         3222             /* ... except perhaps newline.  */
         3223             if (!(bufp->syntax & RE_DOT_NEWLINE))
         3224               fastmap['\n'] = fastmap_newline;
         3225 
         3226             /* Return if we have already set `can_be_null'; if we have,
         3227                then the fastmap is irrelevant.  Something's wrong here.  */
         3228             else if (bufp->can_be_null)
         3229               goto done;
         3230 
         3231             /* Otherwise, have to check alternative paths.  */
         3232             break;
         3233           }
         3234 
         3235 #ifdef emacs
         3236         case syntaxspec:
         3237           k = *p++;
         3238           for (j = 0; j < (1 << BYTEWIDTH); j++)
         3239             if (SYNTAX (j) == (enum syntaxcode) k)
         3240               fastmap[j] = 1;
         3241           break;
         3242 
         3243 
         3244         case notsyntaxspec:
         3245           k = *p++;
         3246           for (j = 0; j < (1 << BYTEWIDTH); j++)
         3247             if (SYNTAX (j) != (enum syntaxcode) k)
         3248               fastmap[j] = 1;
         3249           break;
         3250 
         3251 
         3252       /* All cases after this match the empty string.  These end with
         3253          `continue'.  */
         3254 
         3255 
         3256         case before_dot:
         3257         case at_dot:
         3258         case after_dot:
         3259           continue;
         3260 #endif /* emacs */
         3261 
         3262 
         3263         case no_op:
         3264         case begline:
         3265         case endline:
         3266         case begbuf:
         3267         case endbuf:
         3268         case wordbound:
         3269         case notwordbound:
         3270         case wordbeg:
         3271         case wordend:
         3272         case push_dummy_failure:
         3273           continue;
         3274 
         3275 
         3276         case jump_n:
         3277         case pop_failure_jump:
         3278         case maybe_pop_jump:
         3279         case jump:
         3280         case jump_past_alt:
         3281         case dummy_failure_jump:
         3282           EXTRACT_NUMBER_AND_INCR (j, p);
         3283           p += j;
         3284           if (j > 0)
         3285             continue;
         3286 
         3287           /* Jump backward implies we just went through the body of a
         3288              loop and matched nothing.  Opcode jumped to should be
         3289              `on_failure_jump' or `succeed_n'.  Just treat it like an
         3290              ordinary jump.  For a * loop, it has pushed its failure
         3291              point already; if so, discard that as redundant.  */
         3292           if ((re_opcode_t) *p != on_failure_jump
         3293               && (re_opcode_t) *p != succeed_n)
         3294             continue;
         3295 
         3296           p++;
         3297           EXTRACT_NUMBER_AND_INCR (j, p);
         3298           p += j;
         3299 
         3300           /* If what's on the stack is where we are now, pop it.  */
         3301           if (!FAIL_STACK_EMPTY ()
         3302               && fail_stack.stack[fail_stack.avail - 1].pointer == p)
         3303             fail_stack.avail--;
         3304 
         3305           continue;
         3306 
         3307 
         3308         case on_failure_jump:
         3309         case on_failure_keep_string_jump:
         3310         handle_on_failure_jump:
         3311           EXTRACT_NUMBER_AND_INCR (j, p);
         3312 
         3313           /* For some patterns, e.g., `(a?)?', `p+j' here points to the
         3314              end of the pattern.  We don't want to push such a point,
         3315              since when we restore it above, entering the switch will
         3316              increment `p' past the end of the pattern.  We don't need
         3317              to push such a point since we obviously won't find any more
         3318              fastmap entries beyond `pend'.  Such a pattern can match
         3319              the null string, though.  */
         3320           if (p + j < pend)
         3321             {
         3322               if (!PUSH_PATTERN_OP (p + j, fail_stack))
         3323                 {
         3324                   RESET_FAIL_STACK ();
         3325                   return -2;
         3326                 }
         3327             }
         3328           else
         3329             bufp->can_be_null = 1;
         3330 
         3331           if (succeed_n_p)
         3332             {
         3333               EXTRACT_NUMBER_AND_INCR (k, p);        /* Skip the n.  */
         3334               succeed_n_p = false;
         3335             }
         3336 
         3337           continue;
         3338 
         3339 
         3340         case succeed_n:
         3341           /* Get to the number of times to succeed.  */
         3342           p += 2;
         3343 
         3344           /* Increment p past the n for when k != 0.  */
         3345           EXTRACT_NUMBER_AND_INCR (k, p);
         3346           if (k == 0)
         3347             {
         3348               p -= 4;
         3349                 succeed_n_p = true;  /* Spaghetti code alert.  */
         3350               goto handle_on_failure_jump;
         3351             }
         3352           continue;
         3353 
         3354 
         3355         case set_number_at:
         3356           p += 4;
         3357           continue;
         3358 
         3359 
         3360         case start_memory:
         3361         case stop_memory:
         3362           p += 2;
         3363           continue;
         3364 
         3365 
         3366         default:
         3367           abort (); /* We have listed all the cases.  */
         3368         } /* switch *p++ */
         3369 
         3370       /* Getting here means we have found the possible starting
         3371          characters for one path of the pattern -- and that the empty
         3372          string does not match.  We need not follow this path further.
         3373          Instead, look at the next alternative (remembered on the
         3374          stack), or quit if no more.  The test at the top of the loop
         3375          does these things.  */
         3376       path_can_be_null = false;
         3377       p = pend;
         3378     } /* while p */
         3379 
         3380   /* Set `can_be_null' for the last path (also the first path, if the
         3381      pattern is empty).  */
         3382   bufp->can_be_null |= path_can_be_null;
         3383 
         3384  done:
         3385   RESET_FAIL_STACK ();
         3386   return 0;
         3387 } /* re_compile_fastmap */
         3388 
         3389 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
         3390    ENDS.  Subsequent matches using PATTERN_BUFFER and REGS will use
         3391    this memory for recording register information.  STARTS and ENDS
         3392    must be allocated using the malloc library routine, and must each
         3393    be at least NUM_REGS * sizeof (regoff_t) bytes long.
         3394 
         3395    If NUM_REGS == 0, then subsequent matches should allocate their own
         3396    register data.
         3397 
         3398    Unless this function is called, the first search or match using
         3399    PATTERN_BUFFER will allocate its own register data, without
         3400    freeing the old data.  */
         3401 
         3402 void
         3403 re_set_registers (bufp, regs, num_regs, starts, ends)
         3404     struct re_pattern_buffer *bufp;
         3405     struct re_registers *regs;
         3406     unsigned num_regs;
         3407     regoff_t *starts, *ends;
         3408 {
         3409   if (num_regs)
         3410     {
         3411       bufp->regs_allocated = REGS_REALLOCATE;
         3412       regs->num_regs = num_regs;
         3413       regs->start = starts;
         3414       regs->end = ends;
         3415     }
         3416   else
         3417     {
         3418       bufp->regs_allocated = REGS_UNALLOCATED;
         3419       regs->num_regs = 0;
         3420       regs->start = regs->end = (regoff_t *) 0;
         3421     }
         3422 }
         3423 
         3424 /* Searching routines.  */
         3425 
         3426 /* Like re_search_2, below, but only one string is specified, and
         3427    doesn't let you say where to stop matching. */
         3428 
         3429 int
         3430 re_search (bufp, string, size, startpos, range, regs)
         3431      struct re_pattern_buffer *bufp;
         3432      const char *string;
         3433      int size, startpos, range;
         3434      struct re_registers *regs;
         3435 {
         3436   return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
         3437                       regs, size);
         3438 }
         3439 
         3440 
         3441 /* Using the compiled pattern in BUFP->buffer, first tries to match the
         3442    virtual concatenation of STRING1 and STRING2, starting first at index
         3443    STARTPOS, then at STARTPOS + 1, and so on.
         3444 
         3445    STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
         3446 
         3447    RANGE is how far to scan while trying to match.  RANGE = 0 means try
         3448    only at STARTPOS; in general, the last start tried is STARTPOS +
         3449    RANGE.
         3450 
         3451    In REGS, return the indices of the virtual concatenation of STRING1
         3452    and STRING2 that matched the entire BUFP->buffer and its contained
         3453    subexpressions.
         3454 
         3455    Do not consider matching one past the index STOP in the virtual
         3456    concatenation of STRING1 and STRING2.
         3457 
         3458    We return either the position in the strings at which the match was
         3459    found, -1 if no match, or -2 if error (such as failure
         3460    stack overflow).  */
         3461 
         3462 int
         3463 re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
         3464      struct re_pattern_buffer *bufp;
         3465      const char *string1, *string2;
         3466      int size1, size2;
         3467      int startpos;
         3468      int range;
         3469      struct re_registers *regs;
         3470      int stop;
         3471 {
         3472   int val;
         3473   register char *fastmap = bufp->fastmap;
         3474   register RE_TRANSLATE_TYPE translate = bufp->translate;
         3475   int total_size = size1 + size2;
         3476   int endpos = startpos + range;
         3477 
         3478   /* Check for out-of-range STARTPOS.  */
         3479   if (startpos < 0 || startpos > total_size)
         3480     return -1;
         3481 
         3482   /* Fix up RANGE if it might eventually take us outside
         3483      the virtual concatenation of STRING1 and STRING2.
         3484      Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE.  */
         3485   if (endpos < 0)
         3486     range = 0 - startpos;
         3487   else if (endpos > total_size)
         3488     range = total_size - startpos;
         3489 
         3490   /* If the search isn't to be a backwards one, don't waste time in a
         3491      search for a pattern that must be anchored.  */
         3492   if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
         3493     {
         3494       if (startpos > 0)
         3495         return -1;
         3496       else
         3497         range = 1;
         3498     }
         3499 
         3500 #ifdef emacs
         3501   /* In a forward search for something that starts with \=.
         3502      don't keep searching past point.  */
         3503   if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0)
         3504     {
         3505       range = PT - startpos;
         3506       if (range <= 0)
         3507         return -1;
         3508     }
         3509 #endif /* emacs */
         3510 
         3511   /* Update the fastmap now if not correct already.  */
         3512   if (fastmap && !bufp->fastmap_accurate)
         3513     if (re_compile_fastmap (bufp) == -2)
         3514       return -2;
         3515 
         3516   /* Loop through the string, looking for a place to start matching.  */
         3517   for (;;)
         3518     {
         3519       /* If a fastmap is supplied, skip quickly over characters that
         3520          cannot be the start of a match.  If the pattern can match the
         3521          null string, however, we don't need to skip characters; we want
         3522          the first null string.  */
         3523       if (fastmap && startpos < total_size && !bufp->can_be_null)
         3524         {
         3525           if (range > 0)        /* Searching forwards.  */
         3526             {
         3527               register const char *d;
         3528               register int lim = 0;
         3529               int irange = range;
         3530 
         3531               if (startpos < size1 && startpos + range >= size1)
         3532                 lim = range - (size1 - startpos);
         3533 
         3534               d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
         3535 
         3536               /* Written out as an if-else to avoid testing `translate'
         3537                  inside the loop.  */
         3538               if (translate)
         3539                 while (range > lim
         3540                        && !fastmap[(unsigned char)
         3541                                    translate[(unsigned char) *d++]])
         3542                   range--;
         3543               else
         3544                 while (range > lim && !fastmap[(unsigned char) *d++])
         3545                   range--;
         3546 
         3547               startpos += irange - range;
         3548             }
         3549           else                                /* Searching backwards.  */
         3550             {
         3551               register char c = (size1 == 0 || startpos >= size1
         3552                                  ? string2[startpos - size1]
         3553                                  : string1[startpos]);
         3554 
         3555               if (!fastmap[(unsigned char) TRANSLATE (c)])
         3556                 goto advance;
         3557             }
         3558         }
         3559 
         3560       /* If can't match the null string, and that's all we have left, fail.  */
         3561       if (range >= 0 && startpos == total_size && fastmap
         3562           && !bufp->can_be_null)
         3563         return -1;
         3564 
         3565       val = re_match_2_internal (bufp, string1, size1, string2, size2,
         3566                                  startpos, regs, stop);
         3567 #ifndef REGEX_MALLOC
         3568 #ifdef C_ALLOCA
         3569       alloca (0);
         3570 #endif
         3571 #endif
         3572 
         3573       if (val >= 0)
         3574         return startpos;
         3575 
         3576       if (val == -2)
         3577         return -2;
         3578 
         3579     advance:
         3580       if (!range)
         3581         break;
         3582       else if (range > 0)
         3583         {
         3584           range--;
         3585           startpos++;
         3586         }
         3587       else
         3588         {
         3589           range++;
         3590           startpos--;
         3591         }
         3592     }
         3593   return -1;
         3594 } /* re_search_2 */
         3595 
         3596 /* This converts PTR, a pointer into one of the search strings `string1'
         3597    and `string2' into an offset from the beginning of that string.  */
         3598 #define POINTER_TO_OFFSET(ptr)                        \
         3599   (FIRST_STRING_P (ptr)                                \
         3600    ? ((regoff_t) ((ptr) - string1))                \
         3601    : ((regoff_t) ((ptr) - string2 + size1)))
         3602 
         3603 /* Macros for dealing with the split strings in re_match_2.  */
         3604 
         3605 #define MATCHING_IN_FIRST_STRING  (dend == end_match_1)
         3606 
         3607 /* Call before fetching a character with *d.  This switches over to
         3608    string2 if necessary.  */
         3609 #define PREFETCH()                                                        \
         3610   while (d == dend)                                                            \
         3611     {                                                                        \
         3612       /* End of string2 => fail.  */                                        \
         3613       if (dend == end_match_2)                                                 \
         3614         goto fail;                                                        \
         3615       /* End of string1 => advance to string2.  */                         \
         3616       d = string2;                                                        \
         3617       dend = end_match_2;                                                \
         3618     }
         3619 
         3620 
         3621 /* Test if at very beginning or at very end of the virtual concatenation
         3622    of `string1' and `string2'.  If only one string, it's `string2'.  */
         3623 #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
         3624 #define AT_STRINGS_END(d) ((d) == end2)
         3625 
         3626 
         3627 /* Test if D points to a character which is word-constituent.  We have
         3628    two special cases to check for: if past the end of string1, look at
         3629    the first character in string2; and if before the beginning of
         3630    string2, look at the last character in string1.  */
         3631 #define WORDCHAR_P(d)                                                        \
         3632   (SYNTAX ((d) == end1 ? *string2                                        \
         3633            : (d) == string2 - 1 ? *(end1 - 1) : *(d))                        \
         3634    == Sword)
         3635 
         3636 /* Disabled due to a compiler bug -- see comment at case wordbound */
         3637 #if 0
         3638 /* Test if the character before D and the one at D differ with respect
         3639    to being word-constituent.  */
         3640 #define AT_WORD_BOUNDARY(d)                                                \
         3641   (AT_STRINGS_BEG (d) || AT_STRINGS_END (d)                                \
         3642    || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
         3643 #endif
         3644 
         3645 /* Free everything we malloc.  */
         3646 #ifdef MATCH_MAY_ALLOCATE
         3647 #define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
         3648 #define FREE_VARIABLES()                                                \
         3649   do {                                                                        \
         3650     REGEX_FREE_STACK (fail_stack.stack);                                \
         3651     FREE_VAR (regstart);                                                \
         3652     FREE_VAR (regend);                                                        \
         3653     FREE_VAR (old_regstart);                                                \
         3654     FREE_VAR (old_regend);                                                \
         3655     FREE_VAR (best_regstart);                                                \
         3656     FREE_VAR (best_regend);                                                \
         3657     FREE_VAR (reg_info);                                                \
         3658     FREE_VAR (reg_dummy);                                                \
         3659     FREE_VAR (reg_info_dummy);                                                \
         3660   } while (0)
         3661 #else
         3662 #define FREE_VARIABLES() ((void)0) /* Do nothing!  But inhibit gcc warning.  */
         3663 #endif /* not MATCH_MAY_ALLOCATE */
         3664 
         3665 /* These values must meet several constraints.  They must not be valid
         3666    register values; since we have a limit of 255 registers (because
         3667    we use only one byte in the pattern for the register number), we can
         3668    use numbers larger than 255.  They must differ by 1, because of
         3669    NUM_FAILURE_ITEMS above.  And the value for the lowest register must
         3670    be larger than the value for the highest register, so we do not try
         3671    to actually save any registers when none are active.  */
         3672 #define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
         3673 #define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
         3674 
         3675 /* Matching routines.  */
         3676 
         3677 #ifndef emacs   /* Emacs never uses this.  */
         3678 /* re_match is like re_match_2 except it takes only a single string.  */
         3679 
         3680 int
         3681 re_match (bufp, string, size, pos, regs)
         3682      struct re_pattern_buffer *bufp;
         3683      const char *string;
         3684      int size, pos;
         3685      struct re_registers *regs;
         3686 {
         3687   int result = re_match_2_internal (bufp, NULL, 0, string, size,
         3688                                     pos, regs, size);
         3689 #ifndef REGEX_MALLOC
         3690 #ifdef C_ALLOCA
         3691   alloca (0);
         3692 #endif
         3693 #endif
         3694   return result;
         3695 }
         3696 #endif /* not emacs */
         3697 
         3698 static boolean group_match_null_string_p _RE_ARGS ((unsigned char **p,
         3699                                                     unsigned char *end,
         3700                                                 register_info_type *reg_info));
         3701 static boolean alt_match_null_string_p _RE_ARGS ((unsigned char *p,
         3702                                                   unsigned char *end,
         3703                                                 register_info_type *reg_info));
         3704 static boolean common_op_match_null_string_p _RE_ARGS ((unsigned char **p,
         3705                                                         unsigned char *end,
         3706                                                 register_info_type *reg_info));
         3707 static int bcmp_translate _RE_ARGS ((const char *s1, const char *s2,
         3708                                      int len, char *translate));
         3709 
         3710 /* re_match_2 matches the compiled pattern in BUFP against the
         3711    the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
         3712    and SIZE2, respectively).  We start matching at POS, and stop
         3713    matching at STOP.
         3714 
         3715    If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
         3716    store offsets for the substring each group matched in REGS.  See the
         3717    documentation for exactly how many groups we fill.
         3718 
         3719    We return -1 if no match, -2 if an internal error (such as the
         3720    failure stack overflowing).  Otherwise, we return the length of the
         3721    matched substring.  */
         3722 
         3723 int
         3724 re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
         3725      struct re_pattern_buffer *bufp;
         3726      const char *string1, *string2;
         3727      int size1, size2;
         3728      int pos;
         3729      struct re_registers *regs;
         3730      int stop;
         3731 {
         3732   int result = re_match_2_internal (bufp, string1, size1, string2, size2,
         3733                                     pos, regs, stop);
         3734 #ifndef REGEX_MALLOC
         3735 #ifdef C_ALLOCA
         3736   alloca (0);
         3737 #endif
         3738 #endif
         3739   return result;
         3740 }
         3741 
         3742 /* This is a separate function so that we can force an alloca cleanup
         3743    afterwards.  */
         3744 static int
         3745 re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
         3746      struct re_pattern_buffer *bufp;
         3747      const char *string1, *string2;
         3748      int size1, size2;
         3749      int pos;
         3750      struct re_registers *regs;
         3751      int stop;
         3752 {
         3753   /* General temporaries.  */
         3754   int mcnt;
         3755   unsigned char *p1;
         3756 
         3757   /* Just past the end of the corresponding string.  */
         3758   const char *end1, *end2;
         3759 
         3760   /* Pointers into string1 and string2, just past the last characters in
         3761      each to consider matching.  */
         3762   const char *end_match_1, *end_match_2;
         3763 
         3764   /* Where we are in the data, and the end of the current string.  */
         3765   const char *d, *dend;
         3766 
         3767   /* Where we are in the pattern, and the end of the pattern.  */
         3768   unsigned char *p = bufp->buffer;
         3769   register unsigned char *pend = p + bufp->used;
         3770 
         3771   /* Mark the opcode just after a start_memory, so we can test for an
         3772      empty subpattern when we get to the stop_memory.  */
         3773   unsigned char *just_past_start_mem = 0;
         3774 
         3775   /* We use this to map every character in the string.  */
         3776   RE_TRANSLATE_TYPE translate = bufp->translate;
         3777 
         3778   /* Failure point stack.  Each place that can handle a failure further
         3779      down the line pushes a failure point on this stack.  It consists of
         3780      restart, regend, and reg_info for all registers corresponding to
         3781      the subexpressions we're currently inside, plus the number of such
         3782      registers, and, finally, two char *'s.  The first char * is where
         3783      to resume scanning the pattern; the second one is where to resume
         3784      scanning the strings.  If the latter is zero, the failure point is
         3785      a ``dummy''; if a failure happens and the failure point is a dummy,
         3786      it gets discarded and the next next one is tried.  */
         3787 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
         3788   fail_stack_type fail_stack;
         3789 #endif
         3790 #ifdef DEBUG
         3791   static unsigned failure_id = 0;
         3792   unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
         3793 #endif
         3794 
         3795 #ifdef REL_ALLOC
         3796   /* This holds the pointer to the failure stack, when
         3797      it is allocated relocatably.  */
         3798   fail_stack_elt_t *failure_stack_ptr;
         3799 #endif
         3800 
         3801   /* We fill all the registers internally, independent of what we
         3802      return, for use in backreferences.  The number here includes
         3803      an element for register zero.  */
         3804   size_t num_regs = bufp->re_nsub + 1;
         3805 
         3806   /* The currently active registers.  */
         3807   active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
         3808   active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;
         3809 
         3810   /* Information on the contents of registers. These are pointers into
         3811      the input strings; they record just what was matched (on this
         3812      attempt) by a subexpression part of the pattern, that is, the
         3813      regnum-th regstart pointer points to where in the pattern we began
         3814      matching and the regnum-th regend points to right after where we
         3815      stopped matching the regnum-th subexpression.  (The zeroth register
         3816      keeps track of what the whole pattern matches.)  */
         3817 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
         3818   const char **regstart, **regend;
         3819 #endif
         3820 
         3821   /* If a group that's operated upon by a repetition operator fails to
         3822      match anything, then the register for its start will need to be
         3823      restored because it will have been set to wherever in the string we
         3824      are when we last see its open-group operator.  Similarly for a
         3825      register's end.  */
         3826 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
         3827   const char **old_regstart, **old_regend;
         3828 #endif
         3829 
         3830   /* The is_active field of reg_info helps us keep track of which (possibly
         3831      nested) subexpressions we are currently in. The matched_something
         3832      field of reg_info[reg_num] helps us tell whether or not we have
         3833      matched any of the pattern so far this time through the reg_num-th
         3834      subexpression.  These two fields get reset each time through any
         3835      loop their register is in.  */
         3836 #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
         3837   register_info_type *reg_info;
         3838 #endif
         3839 
         3840   /* The following record the register info as found in the above
         3841      variables when we find a match better than any we've seen before.
         3842      This happens as we backtrack through the failure points, which in
         3843      turn happens only if we have not yet matched the entire string. */
         3844   unsigned best_regs_set = false;
         3845 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
         3846   const char **best_regstart, **best_regend;
         3847 #endif
         3848 
         3849   /* Logically, this is `best_regend[0]'.  But we don't want to have to
         3850      allocate space for that if we're not allocating space for anything
         3851      else (see below).  Also, we never need info about register 0 for
         3852      any of the other register vectors, and it seems rather a kludge to
         3853      treat `best_regend' differently than the rest.  So we keep track of
         3854      the end of the best match so far in a separate variable.  We
         3855      initialize this to NULL so that when we backtrack the first time
         3856      and need to test it, it's not garbage.  */
         3857   const char *match_end = NULL;
         3858 
         3859   /* This helps SET_REGS_MATCHED avoid doing redundant work.  */
         3860   int set_regs_matched_done = 0;
         3861 
         3862   /* Used when we pop values we don't care about.  */
         3863 #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
         3864   const char **reg_dummy;
         3865   register_info_type *reg_info_dummy;
         3866 #endif
         3867 
         3868 #ifdef DEBUG
         3869   /* Counts the total number of registers pushed.  */
         3870   unsigned num_regs_pushed = 0;
         3871 #endif
         3872 
         3873   DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
         3874 
         3875   INIT_FAIL_STACK ();
         3876 
         3877 #ifdef MATCH_MAY_ALLOCATE
         3878   /* Do not bother to initialize all the register variables if there are
         3879      no groups in the pattern, as it takes a fair amount of time.  If
         3880      there are groups, we include space for register 0 (the whole
         3881      pattern), even though we never use it, since it simplifies the
         3882      array indexing.  We should fix this.  */
         3883   if (bufp->re_nsub)
         3884     {
         3885       regstart = REGEX_TALLOC (num_regs, const char *);
         3886       regend = REGEX_TALLOC (num_regs, const char *);
         3887       old_regstart = REGEX_TALLOC (num_regs, const char *);
         3888       old_regend = REGEX_TALLOC (num_regs, const char *);
         3889       best_regstart = REGEX_TALLOC (num_regs, const char *);
         3890       best_regend = REGEX_TALLOC (num_regs, const char *);
         3891       reg_info = REGEX_TALLOC (num_regs, register_info_type);
         3892       reg_dummy = REGEX_TALLOC (num_regs, const char *);
         3893       reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);
         3894 
         3895       if (!(regstart && regend && old_regstart && old_regend && reg_info
         3896             && best_regstart && best_regend && reg_dummy && reg_info_dummy))
         3897         {
         3898           FREE_VARIABLES ();
         3899           return -2;
         3900         }
         3901     }
         3902   else
         3903     {
         3904       /* We must initialize all our variables to NULL, so that
         3905          `FREE_VARIABLES' doesn't try to free them.  */
         3906       regstart = regend = old_regstart = old_regend = best_regstart
         3907         = best_regend = reg_dummy = NULL;
         3908       reg_info = reg_info_dummy = (register_info_type *) NULL;
         3909     }
         3910 #endif /* MATCH_MAY_ALLOCATE */
         3911 
         3912   /* The starting position is bogus.  */
         3913   if (pos < 0 || pos > size1 + size2)
         3914     {
         3915       FREE_VARIABLES ();
         3916       return -1;
         3917     }
         3918 
         3919   /* Initialize subexpression text positions to -1 to mark ones that no
         3920      start_memory/stop_memory has been seen for. Also initialize the
         3921      register information struct.  */
         3922   for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
         3923     {
         3924       regstart[mcnt] = regend[mcnt]
         3925         = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
         3926 
         3927       REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
         3928       IS_ACTIVE (reg_info[mcnt]) = 0;
         3929       MATCHED_SOMETHING (reg_info[mcnt]) = 0;
         3930       EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
         3931     }
         3932 
         3933   /* We move `string1' into `string2' if the latter's empty -- but not if
         3934      `string1' is null.  */
         3935   if (size2 == 0 && string1 != NULL)
         3936     {
         3937       string2 = string1;
         3938       size2 = size1;
         3939       string1 = 0;
         3940       size1 = 0;
         3941     }
         3942   end1 = string1 + size1;
         3943   end2 = string2 + size2;
         3944 
         3945   /* Compute where to stop matching, within the two strings.  */
         3946   if (stop <= size1)
         3947     {
         3948       end_match_1 = string1 + stop;
         3949       end_match_2 = string2;
         3950     }
         3951   else
         3952     {
         3953       end_match_1 = end1;
         3954       end_match_2 = string2 + stop - size1;
         3955     }
         3956 
         3957   /* `p' scans through the pattern as `d' scans through the data.
         3958      `dend' is the end of the input string that `d' points within.  `d'
         3959      is advanced into the following input string whenever necessary, but
         3960      this happens before fetching; therefore, at the beginning of the
         3961      loop, `d' can be pointing at the end of a string, but it cannot
         3962      equal `string2'.  */
         3963   if (size1 > 0 && pos <= size1)
         3964     {
         3965       d = string1 + pos;
         3966       dend = end_match_1;
         3967     }
         3968   else
         3969     {
         3970       d = string2 + pos - size1;
         3971       dend = end_match_2;
         3972     }
         3973 
         3974   DEBUG_PRINT1 ("The compiled pattern is:\n");
         3975   DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
         3976   DEBUG_PRINT1 ("The string to match is: `");
         3977   DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
         3978   DEBUG_PRINT1 ("'\n");
         3979 
         3980   /* This loops over pattern commands.  It exits by returning from the
         3981      function if the match is complete, or it drops through if the match
         3982      fails at this starting point in the input data.  */
         3983   for (;;)
         3984     {
         3985 #ifdef _LIBC
         3986       DEBUG_PRINT2 ("\n%p: ", p);
         3987 #else
         3988       DEBUG_PRINT2 ("\n0x%x: ", p);
         3989 #endif
         3990 
         3991       if (p == pend)
         3992         { /* End of pattern means we might have succeeded.  */
         3993           DEBUG_PRINT1 ("end of pattern ... ");
         3994 
         3995           /* If we haven't matched the entire string, and we want the
         3996              longest match, try backtracking.  */
         3997           if (d != end_match_2)
         3998             {
         3999               /* 1 if this match ends in the same string (string1 or string2)
         4000                  as the best previous match.  */
         4001               boolean same_str_p = (FIRST_STRING_P (match_end)
         4002                                     == MATCHING_IN_FIRST_STRING);
         4003               /* 1 if this match is the best seen so far.  */
         4004               boolean best_match_p;
         4005 
         4006               /* AIX compiler got confused when this was combined
         4007                  with the previous declaration.  */
         4008               if (same_str_p)
         4009                 best_match_p = d > match_end;
         4010               else
         4011                 best_match_p = !MATCHING_IN_FIRST_STRING;
         4012 
         4013               DEBUG_PRINT1 ("backtracking.\n");
         4014 
         4015               if (!FAIL_STACK_EMPTY ())
         4016                 { /* More failure points to try.  */
         4017 
         4018                   /* If exceeds best match so far, save it.  */
         4019                   if (!best_regs_set || best_match_p)
         4020                     {
         4021                       best_regs_set = true;
         4022                       match_end = d;
         4023 
         4024                       DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
         4025 
         4026                       for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
         4027                         {
         4028                           best_regstart[mcnt] = regstart[mcnt];
         4029                           best_regend[mcnt] = regend[mcnt];
         4030                         }
         4031                     }
         4032                   goto fail;
         4033                 }
         4034 
         4035               /* If no failure points, don't restore garbage.  And if
         4036                  last match is real best match, don't restore second
         4037                  best one. */
         4038               else if (best_regs_set && !best_match_p)
         4039                 {
         4040                   restore_best_regs:
         4041                   /* Restore best match.  It may happen that `dend ==
         4042                      end_match_1' while the restored d is in string2.
         4043                      For example, the pattern `x.*y.*z' against the
         4044                      strings `x-' and `y-z-', if the two strings are
         4045                      not consecutive in memory.  */
         4046                   DEBUG_PRINT1 ("Restoring best registers.\n");
         4047 
         4048                   d = match_end;
         4049                   dend = ((d >= string1 && d <= end1)
         4050                            ? end_match_1 : end_match_2);
         4051 
         4052                   for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
         4053                     {
         4054                       regstart[mcnt] = best_regstart[mcnt];
         4055                       regend[mcnt] = best_regend[mcnt];
         4056                     }
         4057                 }
         4058             } /* d != end_match_2 */
         4059 
         4060         succeed_label:
         4061           DEBUG_PRINT1 ("Accepting match.\n");
         4062 
         4063           /* If caller wants register contents data back, do it.  */
         4064           if (regs && !bufp->no_sub)
         4065             {
         4066               /* Have the register data arrays been allocated?  */
         4067               if (bufp->regs_allocated == REGS_UNALLOCATED)
         4068                 { /* No.  So allocate them with malloc.  We need one
         4069                      extra element beyond `num_regs' for the `-1' marker
         4070                      GNU code uses.  */
         4071                   regs->num_regs = MAX (RE_NREGS, num_regs + 1);
         4072                   regs->start = TALLOC (regs->num_regs, regoff_t);
         4073                   regs->end = TALLOC (regs->num_regs, regoff_t);
         4074                   if (regs->start == NULL || regs->end == NULL)
         4075                     {
         4076                       FREE_VARIABLES ();
         4077                       return -2;
         4078                     }
         4079                   bufp->regs_allocated = REGS_REALLOCATE;
         4080                 }
         4081               else if (bufp->regs_allocated == REGS_REALLOCATE)
         4082                 { /* Yes.  If we need more elements than were already
         4083                      allocated, reallocate them.  If we need fewer, just
         4084                      leave it alone.  */
         4085                   if (regs->num_regs < num_regs + 1)
         4086                     {
         4087                       regs->num_regs = num_regs + 1;
         4088                       RETALLOC (regs->start, regs->num_regs, regoff_t);
         4089                       RETALLOC (regs->end, regs->num_regs, regoff_t);
         4090                       if (regs->start == NULL || regs->end == NULL)
         4091                         {
         4092                           FREE_VARIABLES ();
         4093                           return -2;
         4094                         }
         4095                     }
         4096                 }
         4097               else
         4098                 {
         4099                   /* These braces fend off a "empty body in an else-statement"
         4100                      warning under GCC when assert expands to nothing.  */
         4101                   assert (bufp->regs_allocated == REGS_FIXED);
         4102                 }
         4103 
         4104               /* Convert the pointer data in `regstart' and `regend' to
         4105                  indices.  Register zero has to be set differently,
         4106                  since we haven't kept track of any info for it.  */
         4107               if (regs->num_regs > 0)
         4108                 {
         4109                   regs->start[0] = pos;
         4110                   regs->end[0] = (MATCHING_IN_FIRST_STRING
         4111                                   ? ((regoff_t) (d - string1))
         4112                                   : ((regoff_t) (d - string2 + size1)));
         4113                 }
         4114 
         4115               /* Go through the first `min (num_regs, regs->num_regs)'
         4116                  registers, since that is all we initialized.  */
         4117               for (mcnt = 1; (unsigned) mcnt < MIN (num_regs, regs->num_regs);
         4118                    mcnt++)
         4119                 {
         4120                   if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
         4121                     regs->start[mcnt] = regs->end[mcnt] = -1;
         4122                   else
         4123                     {
         4124                       regs->start[mcnt]
         4125                         = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
         4126                       regs->end[mcnt]
         4127                         = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
         4128                     }
         4129                 }
         4130 
         4131               /* If the regs structure we return has more elements than
         4132                  were in the pattern, set the extra elements to -1.  If
         4133                  we (re)allocated the registers, this is the case,
         4134                  because we always allocate enough to have at least one
         4135                  -1 at the end.  */
         4136               for (mcnt = num_regs; (unsigned) mcnt < regs->num_regs; mcnt++)
         4137                 regs->start[mcnt] = regs->end[mcnt] = -1;
         4138             } /* regs && !bufp->no_sub */
         4139 
         4140           DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
         4141                         nfailure_points_pushed, nfailure_points_popped,
         4142                         nfailure_points_pushed - nfailure_points_popped);
         4143           DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
         4144 
         4145           mcnt = d - pos - (MATCHING_IN_FIRST_STRING
         4146                             ? string1
         4147                             : string2 - size1);
         4148 
         4149           DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
         4150 
         4151           FREE_VARIABLES ();
         4152           return mcnt;
         4153         }
         4154 
         4155       /* Otherwise match next pattern command.  */
         4156       switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
         4157         {
         4158         /* Ignore these.  Used to ignore the n of succeed_n's which
         4159            currently have n == 0.  */
         4160         case no_op:
         4161           DEBUG_PRINT1 ("EXECUTING no_op.\n");
         4162           break;
         4163 
         4164         case succeed:
         4165           DEBUG_PRINT1 ("EXECUTING succeed.\n");
         4166           goto succeed_label;
         4167 
         4168         /* Match the next n pattern characters exactly.  The following
         4169            byte in the pattern defines n, and the n bytes after that
         4170            are the characters to match.  */
         4171         case exactn:
         4172           mcnt = *p++;
         4173           DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
         4174 
         4175           /* This is written out as an if-else so we don't waste time
         4176              testing `translate' inside the loop.  */
         4177           if (translate)
         4178             {
         4179               do
         4180                 {
         4181                   PREFETCH ();
         4182                   if ((unsigned char) translate[(unsigned char) *d++]
         4183                       != (unsigned char) *p++)
         4184                     goto fail;
         4185                 }
         4186               while (--mcnt);
         4187             }
         4188           else
         4189             {
         4190               do
         4191                 {
         4192                   PREFETCH ();
         4193                   if (*d++ != (char) *p++) goto fail;
         4194                 }
         4195               while (--mcnt);
         4196             }
         4197           SET_REGS_MATCHED ();
         4198           break;
         4199 
         4200 
         4201         /* Match any character except possibly a newline or a null.  */
         4202         case anychar:
         4203           DEBUG_PRINT1 ("EXECUTING anychar.\n");
         4204 
         4205           PREFETCH ();
         4206 
         4207           if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
         4208               || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
         4209             goto fail;
         4210 
         4211           SET_REGS_MATCHED ();
         4212           DEBUG_PRINT2 ("  Matched `%d'.\n", *d);
         4213           d++;
         4214           break;
         4215 
         4216 
         4217         case charset:
         4218         case charset_not:
         4219           {
         4220             register unsigned char c;
         4221             boolean not = (re_opcode_t) *(p - 1) == charset_not;
         4222 
         4223             DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
         4224 
         4225             PREFETCH ();
         4226             c = TRANSLATE (*d); /* The character to match.  */
         4227 
         4228             /* Cast to `unsigned' instead of `unsigned char' in case the
         4229                bit list is a full 32 bytes long.  */
         4230             if (c < (unsigned) (*p * BYTEWIDTH)
         4231                 && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
         4232               not = !not;
         4233 
         4234             p += 1 + *p;
         4235 
         4236             if (!not) goto fail;
         4237 
         4238             SET_REGS_MATCHED ();
         4239             d++;
         4240             break;
         4241           }
         4242 
         4243 
         4244         /* The beginning of a group is represented by start_memory.
         4245            The arguments are the register number in the next byte, and the
         4246            number of groups inner to this one in the next.  The text
         4247            matched within the group is recorded (in the internal
         4248            registers data structure) under the register number.  */
         4249         case start_memory:
         4250           DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);
         4251 
         4252           /* Find out if this group can match the empty string.  */
         4253           p1 = p;                /* To send to group_match_null_string_p.  */
         4254 
         4255           if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
         4256             REG_MATCH_NULL_STRING_P (reg_info[*p])
         4257               = group_match_null_string_p (&p1, pend, reg_info);
         4258 
         4259           /* Save the position in the string where we were the last time
         4260              we were at this open-group operator in case the group is
         4261              operated upon by a repetition operator, e.g., with `(a*)*b'
         4262              against `ab'; then we want to ignore where we are now in
         4263              the string in case this attempt to match fails.  */
         4264           old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
         4265                              ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
         4266                              : regstart[*p];
         4267           DEBUG_PRINT2 ("  old_regstart: %d\n",
         4268                          POINTER_TO_OFFSET (old_regstart[*p]));
         4269 
         4270           regstart[*p] = d;
         4271           DEBUG_PRINT2 ("  regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
         4272 
         4273           IS_ACTIVE (reg_info[*p]) = 1;
         4274           MATCHED_SOMETHING (reg_info[*p]) = 0;
         4275 
         4276           /* Clear this whenever we change the register activity status.  */
         4277           set_regs_matched_done = 0;
         4278 
         4279           /* This is the new highest active register.  */
         4280           highest_active_reg = *p;
         4281 
         4282           /* If nothing was active before, this is the new lowest active
         4283              register.  */
         4284           if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
         4285             lowest_active_reg = *p;
         4286 
         4287           /* Move past the register number and inner group count.  */
         4288           p += 2;
         4289           just_past_start_mem = p;
         4290 
         4291           break;
         4292 
         4293 
         4294         /* The stop_memory opcode represents the end of a group.  Its
         4295            arguments are the same as start_memory's: the register
         4296            number, and the number of inner groups.  */
         4297         case stop_memory:
         4298           DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);
         4299 
         4300           /* We need to save the string position the last time we were at
         4301              this close-group operator in case the group is operated
         4302              upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
         4303              against `aba'; then we want to ignore where we are now in
         4304              the string in case this attempt to match fails.  */
         4305           old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
         4306                            ? REG_UNSET (regend[*p]) ? d : regend[*p]
         4307                            : regend[*p];
         4308           DEBUG_PRINT2 ("      old_regend: %d\n",
         4309                          POINTER_TO_OFFSET (old_regend[*p]));
         4310 
         4311           regend[*p] = d;
         4312           DEBUG_PRINT2 ("      regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
         4313 
         4314           /* This register isn't active anymore.  */
         4315           IS_ACTIVE (reg_info[*p]) = 0;
         4316 
         4317           /* Clear this whenever we change the register activity status.  */
         4318           set_regs_matched_done = 0;
         4319 
         4320           /* If this was the only register active, nothing is active
         4321              anymore.  */
         4322           if (lowest_active_reg == highest_active_reg)
         4323             {
         4324               lowest_active_reg = NO_LOWEST_ACTIVE_REG;
         4325               highest_active_reg = NO_HIGHEST_ACTIVE_REG;
         4326             }
         4327           else
         4328             { /* We must scan for the new highest active register, since
         4329                  it isn't necessarily one less than now: consider
         4330                  (a(b)c(d(e)f)g).  When group 3 ends, after the f), the
         4331                  new highest active register is 1.  */
         4332               unsigned char r = *p - 1;
         4333               while (r > 0 && !IS_ACTIVE (reg_info[r]))
         4334                 r--;
         4335 
         4336               /* If we end up at register zero, that means that we saved
         4337                  the registers as the result of an `on_failure_jump', not
         4338                  a `start_memory', and we jumped to past the innermost
         4339                  `stop_memory'.  For example, in ((.)*) we save
         4340                  registers 1 and 2 as a result of the *, but when we pop
         4341                  back to the second ), we are at the stop_memory 1.
         4342                  Thus, nothing is active.  */
         4343               if (r == 0)
         4344                 {
         4345                   lowest_active_reg = NO_LOWEST_ACTIVE_REG;
         4346                   highest_active_reg = NO_HIGHEST_ACTIVE_REG;
         4347                 }
         4348               else
         4349                 highest_active_reg = r;
         4350             }
         4351 
         4352           /* If just failed to match something this time around with a
         4353              group that's operated on by a repetition operator, try to
         4354              force exit from the ``loop'', and restore the register
         4355              information for this group that we had before trying this
         4356              last match.  */
         4357           if ((!MATCHED_SOMETHING (reg_info[*p])
         4358                || just_past_start_mem == p - 1)
         4359               && (p + 2) < pend)
         4360             {
         4361               boolean is_a_jump_n = false;
         4362 
         4363               p1 = p + 2;
         4364               mcnt = 0;
         4365               switch ((re_opcode_t) *p1++)
         4366                 {
         4367                   case jump_n:
         4368                     is_a_jump_n = true;
         4369                   case pop_failure_jump:
         4370                   case maybe_pop_jump:
         4371                   case jump:
         4372                   case dummy_failure_jump:
         4373                     EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         4374                     if (is_a_jump_n)
         4375                       p1 += 2;
         4376                     break;
         4377 
         4378                   default:
         4379                     /* do nothing */ ;
         4380                 }
         4381               p1 += mcnt;
         4382 
         4383               /* If the next operation is a jump backwards in the pattern
         4384                  to an on_failure_jump right before the start_memory
         4385                  corresponding to this stop_memory, exit from the loop
         4386                  by forcing a failure after pushing on the stack the
         4387                  on_failure_jump's jump in the pattern, and d.  */
         4388               if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
         4389                   && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
         4390                 {
         4391                   /* If this group ever matched anything, then restore
         4392                      what its registers were before trying this last
         4393                      failed match, e.g., with `(a*)*b' against `ab' for
         4394                      regstart[1], and, e.g., with `((a*)*(b*)*)*'
         4395                      against `aba' for regend[3].
         4396 
         4397                      Also restore the registers for inner groups for,
         4398                      e.g., `((a*)(b*))*' against `aba' (register 3 would
         4399                      otherwise get trashed).  */
         4400 
         4401                   if (EVER_MATCHED_SOMETHING (reg_info[*p]))
         4402                     {
         4403                       unsigned r;
         4404 
         4405                       EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
         4406 
         4407                       /* Restore this and inner groups' (if any) registers.  */
         4408                       for (r = *p; r < (unsigned) *p + (unsigned) *(p + 1);
         4409                            r++)
         4410                         {
         4411                           regstart[r] = old_regstart[r];
         4412 
         4413                           /* xx why this test?  */
         4414                           if (old_regend[r] >= regstart[r])
         4415                             regend[r] = old_regend[r];
         4416                         }
         4417                     }
         4418                   p1++;
         4419                   EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         4420                   PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
         4421 
         4422                   goto fail;
         4423                 }
         4424             }
         4425 
         4426           /* Move past the register number and the inner group count.  */
         4427           p += 2;
         4428           break;
         4429 
         4430 
         4431         /* \<digit> has been turned into a `duplicate' command which is
         4432            followed by the numeric value of <digit> as the register number.  */
         4433         case duplicate:
         4434           {
         4435             register const char *d2, *dend2;
         4436             int regno = *p++;   /* Get which register to match against.  */
         4437             DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
         4438 
         4439             /* Can't back reference a group which we've never matched.  */
         4440             if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
         4441               goto fail;
         4442 
         4443             /* Where in input to try to start matching.  */
         4444             d2 = regstart[regno];
         4445 
         4446             /* Where to stop matching; if both the place to start and
         4447                the place to stop matching are in the same string, then
         4448                set to the place to stop, otherwise, for now have to use
         4449                the end of the first string.  */
         4450 
         4451             dend2 = ((FIRST_STRING_P (regstart[regno])
         4452                       == FIRST_STRING_P (regend[regno]))
         4453                      ? regend[regno] : end_match_1);
         4454             for (;;)
         4455               {
         4456                 /* If necessary, advance to next segment in register
         4457                    contents.  */
         4458                 while (d2 == dend2)
         4459                   {
         4460                     if (dend2 == end_match_2) break;
         4461                     if (dend2 == regend[regno]) break;
         4462 
         4463                     /* End of string1 => advance to string2. */
         4464                     d2 = string2;
         4465                     dend2 = regend[regno];
         4466                   }
         4467                 /* At end of register contents => success */
         4468                 if (d2 == dend2) break;
         4469 
         4470                 /* If necessary, advance to next segment in data.  */
         4471                 PREFETCH ();
         4472 
         4473                 /* How many characters left in this segment to match.  */
         4474                 mcnt = dend - d;
         4475 
         4476                 /* Want how many consecutive characters we can match in
         4477                    one shot, so, if necessary, adjust the count.  */
         4478                 if (mcnt > dend2 - d2)
         4479                   mcnt = dend2 - d2;
         4480 
         4481                 /* Compare that many; failure if mismatch, else move
         4482                    past them.  */
         4483                 if (translate
         4484                     ? bcmp_translate (d, d2, mcnt, translate)
         4485                     : bcmp (d, d2, mcnt))
         4486                   goto fail;
         4487                 d += mcnt, d2 += mcnt;
         4488 
         4489                 /* Do this because we've match some characters.  */
         4490                 SET_REGS_MATCHED ();
         4491               }
         4492           }
         4493           break;
         4494 
         4495 
         4496         /* begline matches the empty string at the beginning of the string
         4497            (unless `not_bol' is set in `bufp'), and, if
         4498            `newline_anchor' is set, after newlines.  */
         4499         case begline:
         4500           DEBUG_PRINT1 ("EXECUTING begline.\n");
         4501 
         4502           if (AT_STRINGS_BEG (d))
         4503             {
         4504               if (!bufp->not_bol) break;
         4505             }
         4506           else if (d[-1] == '\n' && bufp->newline_anchor)
         4507             {
         4508               break;
         4509             }
         4510           /* In all other cases, we fail.  */
         4511           goto fail;
         4512 
         4513 
         4514         /* endline is the dual of begline.  */
         4515         case endline:
         4516           DEBUG_PRINT1 ("EXECUTING endline.\n");
         4517 
         4518           if (AT_STRINGS_END (d))
         4519             {
         4520               if (!bufp->not_eol) break;
         4521             }
         4522 
         4523           /* We have to ``prefetch'' the next character.  */
         4524           else if ((d == end1 ? *string2 : *d) == '\n'
         4525                    && bufp->newline_anchor)
         4526             {
         4527               break;
         4528             }
         4529           goto fail;
         4530 
         4531 
         4532         /* Match at the very beginning of the data.  */
         4533         case begbuf:
         4534           DEBUG_PRINT1 ("EXECUTING begbuf.\n");
         4535           if (AT_STRINGS_BEG (d))
         4536             break;
         4537           goto fail;
         4538 
         4539 
         4540         /* Match at the very end of the data.  */
         4541         case endbuf:
         4542           DEBUG_PRINT1 ("EXECUTING endbuf.\n");
         4543           if (AT_STRINGS_END (d))
         4544             break;
         4545           goto fail;
         4546 
         4547 
         4548         /* on_failure_keep_string_jump is used to optimize `.*\n'.  It
         4549            pushes NULL as the value for the string on the stack.  Then
         4550            `pop_failure_point' will keep the current value for the
         4551            string, instead of restoring it.  To see why, consider
         4552            matching `foo\nbar' against `.*\n'.  The .* matches the foo;
         4553            then the . fails against the \n.  But the next thing we want
         4554            to do is match the \n against the \n; if we restored the
         4555            string value, we would be back at the foo.
         4556 
         4557            Because this is used only in specific cases, we don't need to
         4558            check all the things that `on_failure_jump' does, to make
         4559            sure the right things get saved on the stack.  Hence we don't
         4560            share its code.  The only reason to push anything on the
         4561            stack at all is that otherwise we would have to change
         4562            `anychar's code to do something besides goto fail in this
         4563            case; that seems worse than this.  */
         4564         case on_failure_keep_string_jump:
         4565           DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
         4566 
         4567           EXTRACT_NUMBER_AND_INCR (mcnt, p);
         4568 #ifdef _LIBC
         4569           DEBUG_PRINT3 (" %d (to %p):\n", mcnt, p + mcnt);
         4570 #else
         4571           DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
         4572 #endif
         4573 
         4574           PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
         4575           break;
         4576 
         4577 
         4578         /* Uses of on_failure_jump:
         4579 
         4580            Each alternative starts with an on_failure_jump that points
         4581            to the beginning of the next alternative.  Each alternative
         4582            except the last ends with a jump that in effect jumps past
         4583            the rest of the alternatives.  (They really jump to the
         4584            ending jump of the following alternative, because tensioning
         4585            these jumps is a hassle.)
         4586 
         4587            Repeats start with an on_failure_jump that points past both
         4588            the repetition text and either the following jump or
         4589            pop_failure_jump back to this on_failure_jump.  */
         4590         case on_failure_jump:
         4591         on_failure:
         4592           DEBUG_PRINT1 ("EXECUTING on_failure_jump");
         4593 
         4594           EXTRACT_NUMBER_AND_INCR (mcnt, p);
         4595 #ifdef _LIBC
         4596           DEBUG_PRINT3 (" %d (to %p)", mcnt, p + mcnt);
         4597 #else
         4598           DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
         4599 #endif
         4600 
         4601           /* If this on_failure_jump comes right before a group (i.e.,
         4602              the original * applied to a group), save the information
         4603              for that group and all inner ones, so that if we fail back
         4604              to this point, the group's information will be correct.
         4605              For example, in \(a*\)*\1, we need the preceding group,
         4606              and in \(zz\(a*\)b*\)\2, we need the inner group.  */
         4607 
         4608           /* We can't use `p' to check ahead because we push
         4609              a failure point to `p + mcnt' after we do this.  */
         4610           p1 = p;
         4611 
         4612           /* We need to skip no_op's before we look for the
         4613              start_memory in case this on_failure_jump is happening as
         4614              the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
         4615              against aba.  */
         4616           while (p1 < pend && (re_opcode_t) *p1 == no_op)
         4617             p1++;
         4618 
         4619           if (p1 < pend && (re_opcode_t) *p1 == start_memory)
         4620             {
         4621               /* We have a new highest active register now.  This will
         4622                  get reset at the start_memory we are about to get to,
         4623                  but we will have saved all the registers relevant to
         4624                  this repetition op, as described above.  */
         4625               highest_active_reg = *(p1 + 1) + *(p1 + 2);
         4626               if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
         4627                 lowest_active_reg = *(p1 + 1);
         4628             }
         4629 
         4630           DEBUG_PRINT1 (":\n");
         4631           PUSH_FAILURE_POINT (p + mcnt, d, -2);
         4632           break;
         4633 
         4634 
         4635         /* A smart repeat ends with `maybe_pop_jump'.
         4636            We change it to either `pop_failure_jump' or `jump'.  */
         4637         case maybe_pop_jump:
         4638           EXTRACT_NUMBER_AND_INCR (mcnt, p);
         4639           DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
         4640           {
         4641             register unsigned char *p2 = p;
         4642 
         4643             /* Compare the beginning of the repeat with what in the
         4644                pattern follows its end. If we can establish that there
         4645                is nothing that they would both match, i.e., that we
         4646                would have to backtrack because of (as in, e.g., `a*a')
         4647                then we can change to pop_failure_jump, because we'll
         4648                never have to backtrack.
         4649 
         4650                This is not true in the case of alternatives: in
         4651                `(a|ab)*' we do need to backtrack to the `ab' alternative
         4652                (e.g., if the string was `ab').  But instead of trying to
         4653                detect that here, the alternative has put on a dummy
         4654                failure point which is what we will end up popping.  */
         4655 
         4656             /* Skip over open/close-group commands.
         4657                If what follows this loop is a ...+ construct,
         4658                look at what begins its body, since we will have to
         4659                match at least one of that.  */
         4660             while (1)
         4661               {
         4662                 if (p2 + 2 < pend
         4663                     && ((re_opcode_t) *p2 == stop_memory
         4664                         || (re_opcode_t) *p2 == start_memory))
         4665                   p2 += 3;
         4666                 else if (p2 + 6 < pend
         4667                          && (re_opcode_t) *p2 == dummy_failure_jump)
         4668                   p2 += 6;
         4669                 else
         4670                   break;
         4671               }
         4672 
         4673             p1 = p + mcnt;
         4674             /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
         4675                to the `maybe_finalize_jump' of this case.  Examine what
         4676                follows.  */
         4677 
         4678             /* If we're at the end of the pattern, we can change.  */
         4679             if (p2 == pend)
         4680               {
         4681                 /* Consider what happens when matching ":\(.*\)"
         4682                    against ":/".  I don't really understand this code
         4683                    yet.  */
         4684                   p[-3] = (unsigned char) pop_failure_jump;
         4685                 DEBUG_PRINT1
         4686                   ("  End of pattern: change to `pop_failure_jump'.\n");
         4687               }
         4688 
         4689             else if ((re_opcode_t) *p2 == exactn
         4690                      || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
         4691               {
         4692                 register unsigned char c
         4693                   = *p2 == (unsigned char) endline ? '\n' : p2[2];
         4694 
         4695                 if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
         4696                   {
         4697                       p[-3] = (unsigned char) pop_failure_jump;
         4698                     DEBUG_PRINT3 ("  %c != %c => pop_failure_jump.\n",
         4699                                   c, p1[5]);
         4700                   }
         4701 
         4702                 else if ((re_opcode_t) p1[3] == charset
         4703                          || (re_opcode_t) p1[3] == charset_not)
         4704                   {
         4705                     int not = (re_opcode_t) p1[3] == charset_not;
         4706 
         4707                     if (c < (unsigned char) (p1[4] * BYTEWIDTH)
         4708                         && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
         4709                       not = !not;
         4710 
         4711                     /* `not' is equal to 1 if c would match, which means
         4712                         that we can't change to pop_failure_jump.  */
         4713                     if (!not)
         4714                       {
         4715                           p[-3] = (unsigned char) pop_failure_jump;
         4716                         DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
         4717                       }
         4718                   }
         4719               }
         4720             else if ((re_opcode_t) *p2 == charset)
         4721               {
         4722 #ifdef DEBUG
         4723                 register unsigned char c
         4724                   = *p2 == (unsigned char) endline ? '\n' : p2[2];
         4725 #endif
         4726 
         4727 #if 0
         4728                 if ((re_opcode_t) p1[3] == exactn
         4729                     && ! ((int) p2[1] * BYTEWIDTH > (int) p1[5]
         4730                           && (p2[2 + p1[5] / BYTEWIDTH]
         4731                               & (1 << (p1[5] % BYTEWIDTH)))))
         4732 #else
         4733                 if ((re_opcode_t) p1[3] == exactn
         4734                     && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
         4735                           && (p2[2 + p1[4] / BYTEWIDTH]
         4736                               & (1 << (p1[4] % BYTEWIDTH)))))
         4737 #endif
         4738                   {
         4739                       p[-3] = (unsigned char) pop_failure_jump;
         4740                     DEBUG_PRINT3 ("  %c != %c => pop_failure_jump.\n",
         4741                                   c, p1[5]);
         4742                   }
         4743 
         4744                 else if ((re_opcode_t) p1[3] == charset_not)
         4745                   {
         4746                     int idx;
         4747                     /* We win if the charset_not inside the loop
         4748                        lists every character listed in the charset after.  */
         4749                     for (idx = 0; idx < (int) p2[1]; idx++)
         4750                       if (! (p2[2 + idx] == 0
         4751                              || (idx < (int) p1[4]
         4752                                  && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
         4753                         break;
         4754 
         4755                     if (idx == p2[1])
         4756                       {
         4757                           p[-3] = (unsigned char) pop_failure_jump;
         4758                         DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
         4759                       }
         4760                   }
         4761                 else if ((re_opcode_t) p1[3] == charset)
         4762                   {
         4763                     int idx;
         4764                     /* We win if the charset inside the loop
         4765                        has no overlap with the one after the loop.  */
         4766                     for (idx = 0;
         4767                          idx < (int) p2[1] && idx < (int) p1[4];
         4768                          idx++)
         4769                       if ((p2[2 + idx] & p1[5 + idx]) != 0)
         4770                         break;
         4771 
         4772                     if (idx == p2[1] || idx == p1[4])
         4773                       {
         4774                           p[-3] = (unsigned char) pop_failure_jump;
         4775                         DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
         4776                       }
         4777                   }
         4778               }
         4779           }
         4780           p -= 2;                /* Point at relative address again.  */
         4781           if ((re_opcode_t) p[-1] != pop_failure_jump)
         4782             {
         4783               p[-1] = (unsigned char) jump;
         4784               DEBUG_PRINT1 ("  Match => jump.\n");
         4785               goto unconditional_jump;
         4786             }
         4787         /* Note fall through.  */
         4788 
         4789 
         4790         /* The end of a simple repeat has a pop_failure_jump back to
         4791            its matching on_failure_jump, where the latter will push a
         4792            failure point.  The pop_failure_jump takes off failure
         4793            points put on by this pop_failure_jump's matching
         4794            on_failure_jump; we got through the pattern to here from the
         4795            matching on_failure_jump, so didn't fail.  */
         4796         case pop_failure_jump:
         4797           {
         4798             /* We need to pass separate storage for the lowest and
         4799                highest registers, even though we don't care about the
         4800                actual values.  Otherwise, we will restore only one
         4801                register from the stack, since lowest will == highest in
         4802                `pop_failure_point'.  */
         4803             active_reg_t dummy_low_reg, dummy_high_reg;
         4804             unsigned char *pdummy __attribute__ ((__unused__));
         4805             const char *sdummy __attribute__ ((__unused__));
         4806 
         4807             DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
         4808             POP_FAILURE_POINT (sdummy, pdummy,
         4809                                dummy_low_reg, dummy_high_reg,
         4810                                reg_dummy, reg_dummy, reg_info_dummy);
         4811           }
         4812           /* Note fall through.  */
         4813 
         4814         unconditional_jump:
         4815 #ifdef _LIBC
         4816           DEBUG_PRINT2 ("\n%p: ", p);
         4817 #else
         4818           DEBUG_PRINT2 ("\n0x%x: ", p);
         4819 #endif
         4820           /* Note fall through.  */
         4821 
         4822         /* Unconditionally jump (without popping any failure points).  */
         4823         case jump:
         4824           EXTRACT_NUMBER_AND_INCR (mcnt, p);        /* Get the amount to jump.  */
         4825           DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
         4826           p += mcnt;                                /* Do the jump.  */
         4827 #ifdef _LIBC
         4828           DEBUG_PRINT2 ("(to %p).\n", p);
         4829 #else
         4830           DEBUG_PRINT2 ("(to 0x%x).\n", p);
         4831 #endif
         4832           break;
         4833 
         4834 
         4835         /* We need this opcode so we can detect where alternatives end
         4836            in `group_match_null_string_p' et al.  */
         4837         case jump_past_alt:
         4838           DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
         4839           goto unconditional_jump;
         4840 
         4841 
         4842         /* Normally, the on_failure_jump pushes a failure point, which
         4843            then gets popped at pop_failure_jump.  We will end up at
         4844            pop_failure_jump, also, and with a pattern of, say, `a+', we
         4845            are skipping over the on_failure_jump, so we have to push
         4846            something meaningless for pop_failure_jump to pop.  */
         4847         case dummy_failure_jump:
         4848           DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
         4849           /* It doesn't matter what we push for the string here.  What
         4850              the code at `fail' tests is the value for the pattern.  */
         4851           PUSH_FAILURE_POINT (0, 0, -2);
         4852           goto unconditional_jump;
         4853 
         4854 
         4855         /* At the end of an alternative, we need to push a dummy failure
         4856            point in case we are followed by a `pop_failure_jump', because
         4857            we don't want the failure point for the alternative to be
         4858            popped.  For example, matching `(a|ab)*' against `aab'
         4859            requires that we match the `ab' alternative.  */
         4860         case push_dummy_failure:
         4861           DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
         4862           /* See comments just above at `dummy_failure_jump' about the
         4863              two zeroes.  */
         4864           PUSH_FAILURE_POINT (0, 0, -2);
         4865           break;
         4866 
         4867         /* Have to succeed matching what follows at least n times.
         4868            After that, handle like `on_failure_jump'.  */
         4869         case succeed_n:
         4870           EXTRACT_NUMBER (mcnt, p + 2);
         4871           DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
         4872 
         4873           assert (mcnt >= 0);
         4874           /* Originally, this is how many times we HAVE to succeed.  */
         4875           if (mcnt > 0)
         4876             {
         4877                mcnt--;
         4878                p += 2;
         4879                STORE_NUMBER_AND_INCR (p, mcnt);
         4880 #ifdef _LIBC
         4881                DEBUG_PRINT3 ("  Setting %p to %d.\n", p - 2, mcnt);
         4882 #else
         4883                DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p - 2, mcnt);
         4884 #endif
         4885             }
         4886           else if (mcnt == 0)
         4887             {
         4888 #ifdef _LIBC
         4889               DEBUG_PRINT2 ("  Setting two bytes from %p to no_op.\n", p+2);
         4890 #else
         4891               DEBUG_PRINT2 ("  Setting two bytes from 0x%x to no_op.\n", p+2);
         4892 #endif
         4893               p[2] = (unsigned char) no_op;
         4894               p[3] = (unsigned char) no_op;
         4895               goto on_failure;
         4896             }
         4897           break;
         4898 
         4899         case jump_n:
         4900           EXTRACT_NUMBER (mcnt, p + 2);
         4901           DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
         4902 
         4903           /* Originally, this is how many times we CAN jump.  */
         4904           if (mcnt)
         4905             {
         4906                mcnt--;
         4907                STORE_NUMBER (p + 2, mcnt);
         4908 #ifdef _LIBC
         4909                DEBUG_PRINT3 ("  Setting %p to %d.\n", p + 2, mcnt);
         4910 #else
         4911                DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p + 2, mcnt);
         4912 #endif
         4913                goto unconditional_jump;
         4914             }
         4915           /* If don't have to jump any more, skip over the rest of command.  */
         4916           else
         4917             p += 4;
         4918           break;
         4919 
         4920         case set_number_at:
         4921           {
         4922             DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
         4923 
         4924             EXTRACT_NUMBER_AND_INCR (mcnt, p);
         4925             p1 = p + mcnt;
         4926             EXTRACT_NUMBER_AND_INCR (mcnt, p);
         4927 #ifdef _LIBC
         4928             DEBUG_PRINT3 ("  Setting %p to %d.\n", p1, mcnt);
         4929 #else
         4930             DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p1, mcnt);
         4931 #endif
         4932             STORE_NUMBER (p1, mcnt);
         4933             break;
         4934           }
         4935 
         4936 #if 0
         4937         /* The DEC Alpha C compiler 3.x generates incorrect code for the
         4938            test  WORDCHAR_P (d - 1) != WORDCHAR_P (d)  in the expansion of
         4939            AT_WORD_BOUNDARY, so this code is disabled.  Expanding the
         4940            macro and introducing temporary variables works around the bug.  */
         4941 
         4942         case wordbound:
         4943           DEBUG_PRINT1 ("EXECUTING wordbound.\n");
         4944           if (AT_WORD_BOUNDARY (d))
         4945             break;
         4946           goto fail;
         4947 
         4948         case notwordbound:
         4949           DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
         4950           if (AT_WORD_BOUNDARY (d))
         4951             goto fail;
         4952           break;
         4953 #else
         4954         case wordbound:
         4955         {
         4956           boolean prevchar, thischar;
         4957 
         4958           DEBUG_PRINT1 ("EXECUTING wordbound.\n");
         4959           if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
         4960             break;
         4961 
         4962           prevchar = WORDCHAR_P (d - 1);
         4963           thischar = WORDCHAR_P (d);
         4964           if (prevchar != thischar)
         4965             break;
         4966           goto fail;
         4967         }
         4968 
         4969       case notwordbound:
         4970         {
         4971           boolean prevchar, thischar;
         4972 
         4973           DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
         4974           if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
         4975             goto fail;
         4976 
         4977           prevchar = WORDCHAR_P (d - 1);
         4978           thischar = WORDCHAR_P (d);
         4979           if (prevchar != thischar)
         4980             goto fail;
         4981           break;
         4982         }
         4983 #endif
         4984 
         4985         case wordbeg:
         4986           DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
         4987           if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
         4988             break;
         4989           goto fail;
         4990 
         4991         case wordend:
         4992           DEBUG_PRINT1 ("EXECUTING wordend.\n");
         4993           if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
         4994               && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
         4995             break;
         4996           goto fail;
         4997 
         4998 #ifdef emacs
         4999           case before_dot:
         5000           DEBUG_PRINT1 ("EXECUTING before_dot.\n");
         5001            if (PTR_CHAR_POS ((unsigned char *) d) >= point)
         5002               goto fail;
         5003             break;
         5004 
         5005           case at_dot:
         5006           DEBUG_PRINT1 ("EXECUTING at_dot.\n");
         5007            if (PTR_CHAR_POS ((unsigned char *) d) != point)
         5008               goto fail;
         5009             break;
         5010 
         5011           case after_dot:
         5012           DEBUG_PRINT1 ("EXECUTING after_dot.\n");
         5013           if (PTR_CHAR_POS ((unsigned char *) d) <= point)
         5014               goto fail;
         5015             break;
         5016 
         5017         case syntaxspec:
         5018           DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
         5019           mcnt = *p++;
         5020           goto matchsyntax;
         5021 
         5022         case wordchar:
         5023           DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
         5024           mcnt = (int) Sword;
         5025         matchsyntax:
         5026           PREFETCH ();
         5027           /* Can't use *d++ here; SYNTAX may be an unsafe macro.  */
         5028           d++;
         5029           if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
         5030             goto fail;
         5031           SET_REGS_MATCHED ();
         5032           break;
         5033 
         5034         case notsyntaxspec:
         5035           DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
         5036           mcnt = *p++;
         5037           goto matchnotsyntax;
         5038 
         5039         case notwordchar:
         5040           DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
         5041           mcnt = (int) Sword;
         5042         matchnotsyntax:
         5043           PREFETCH ();
         5044           /* Can't use *d++ here; SYNTAX may be an unsafe macro.  */
         5045           d++;
         5046           if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
         5047             goto fail;
         5048           SET_REGS_MATCHED ();
         5049           break;
         5050 
         5051 #else /* not emacs */
         5052         case wordchar:
         5053           DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
         5054           PREFETCH ();
         5055           if (!WORDCHAR_P (d))
         5056             goto fail;
         5057           SET_REGS_MATCHED ();
         5058           d++;
         5059           break;
         5060 
         5061         case notwordchar:
         5062           DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
         5063           PREFETCH ();
         5064           if (WORDCHAR_P (d))
         5065             goto fail;
         5066           SET_REGS_MATCHED ();
         5067           d++;
         5068           break;
         5069 #endif /* not emacs */
         5070 
         5071         default:
         5072           abort ();
         5073         }
         5074       continue;  /* Successfully executed one pattern command; keep going.  */
         5075 
         5076 
         5077     /* We goto here if a matching operation fails. */
         5078     fail:
         5079       if (!FAIL_STACK_EMPTY ())
         5080         { /* A restart point is known.  Restore to that state.  */
         5081           DEBUG_PRINT1 ("\nFAIL:\n");
         5082           POP_FAILURE_POINT (d, p,
         5083                              lowest_active_reg, highest_active_reg,
         5084                              regstart, regend, reg_info);
         5085 
         5086           /* If this failure point is a dummy, try the next one.  */
         5087           if (!p)
         5088             goto fail;
         5089 
         5090           /* If we failed to the end of the pattern, don't examine *p.  */
         5091           assert (p <= pend);
         5092           if (p < pend)
         5093             {
         5094               boolean is_a_jump_n = false;
         5095 
         5096               /* If failed to a backwards jump that's part of a repetition
         5097                  loop, need to pop this failure point and use the next one.  */
         5098               switch ((re_opcode_t) *p)
         5099                 {
         5100                 case jump_n:
         5101                   is_a_jump_n = true;
         5102                 case maybe_pop_jump:
         5103                 case pop_failure_jump:
         5104                 case jump:
         5105                   p1 = p + 1;
         5106                   EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         5107                   p1 += mcnt;
         5108 
         5109                   if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
         5110                       || (!is_a_jump_n
         5111                           && (re_opcode_t) *p1 == on_failure_jump))
         5112                     goto fail;
         5113                   break;
         5114                 default:
         5115                   /* do nothing */ ;
         5116                 }
         5117             }
         5118 
         5119           if (d >= string1 && d <= end1)
         5120             dend = end_match_1;
         5121         }
         5122       else
         5123         break;   /* Matching at this starting point really fails.  */
         5124     } /* for (;;) */
         5125 
         5126   if (best_regs_set)
         5127     goto restore_best_regs;
         5128 
         5129   FREE_VARIABLES ();
         5130 
         5131   return -1;                                 /* Failure to match.  */
         5132 } /* re_match_2 */
         5133 
         5134 /* Subroutine definitions for re_match_2.  */
         5135 
         5136 
         5137 /* We are passed P pointing to a register number after a start_memory.
         5138 
         5139    Return true if the pattern up to the corresponding stop_memory can
         5140    match the empty string, and false otherwise.
         5141 
         5142    If we find the matching stop_memory, sets P to point to one past its number.
         5143    Otherwise, sets P to an undefined byte less than or equal to END.
         5144 
         5145    We don't handle duplicates properly (yet).  */
         5146 
         5147 static boolean
         5148 group_match_null_string_p (p, end, reg_info)
         5149     unsigned char **p, *end;
         5150     register_info_type *reg_info;
         5151 {
         5152   int mcnt;
         5153   /* Point to after the args to the start_memory.  */
         5154   unsigned char *p1 = *p + 2;
         5155 
         5156   while (p1 < end)
         5157     {
         5158       /* Skip over opcodes that can match nothing, and return true or
         5159          false, as appropriate, when we get to one that can't, or to the
         5160          matching stop_memory.  */
         5161 
         5162       switch ((re_opcode_t) *p1)
         5163         {
         5164         /* Could be either a loop or a series of alternatives.  */
         5165         case on_failure_jump:
         5166           p1++;
         5167           EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         5168 
         5169           /* If the next operation is not a jump backwards in the
         5170              pattern.  */
         5171 
         5172           if (mcnt >= 0)
         5173             {
         5174               /* Go through the on_failure_jumps of the alternatives,
         5175                  seeing if any of the alternatives cannot match nothing.
         5176                  The last alternative starts with only a jump,
         5177                  whereas the rest start with on_failure_jump and end
         5178                  with a jump, e.g., here is the pattern for `a|b|c':
         5179 
         5180                  /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
         5181                  /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
         5182                  /exactn/1/c
         5183 
         5184                  So, we have to first go through the first (n-1)
         5185                  alternatives and then deal with the last one separately.  */
         5186 
         5187 
         5188               /* Deal with the first (n-1) alternatives, which start
         5189                  with an on_failure_jump (see above) that jumps to right
         5190                  past a jump_past_alt.  */
         5191 
         5192               while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
         5193                 {
         5194                   /* `mcnt' holds how many bytes long the alternative
         5195                      is, including the ending `jump_past_alt' and
         5196                      its number.  */
         5197 
         5198                   if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
         5199                                                       reg_info))
         5200                     return false;
         5201 
         5202                   /* Move to right after this alternative, including the
         5203                      jump_past_alt.  */
         5204                   p1 += mcnt;
         5205 
         5206                   /* Break if it's the beginning of an n-th alternative
         5207                      that doesn't begin with an on_failure_jump.  */
         5208                   if ((re_opcode_t) *p1 != on_failure_jump)
         5209                     break;
         5210 
         5211                   /* Still have to check that it's not an n-th
         5212                      alternative that starts with an on_failure_jump.  */
         5213                   p1++;
         5214                   EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         5215                   if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
         5216                     {
         5217                       /* Get to the beginning of the n-th alternative.  */
         5218                       p1 -= 3;
         5219                       break;
         5220                     }
         5221                 }
         5222 
         5223               /* Deal with the last alternative: go back and get number
         5224                  of the `jump_past_alt' just before it.  `mcnt' contains
         5225                  the length of the alternative.  */
         5226               EXTRACT_NUMBER (mcnt, p1 - 2);
         5227 
         5228               if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
         5229                 return false;
         5230 
         5231               p1 += mcnt;        /* Get past the n-th alternative.  */
         5232             } /* if mcnt > 0 */
         5233           break;
         5234 
         5235 
         5236         case stop_memory:
         5237           assert (p1[1] == **p);
         5238           *p = p1 + 2;
         5239           return true;
         5240 
         5241 
         5242         default:
         5243           if (!common_op_match_null_string_p (&p1, end, reg_info))
         5244             return false;
         5245         }
         5246     } /* while p1 < end */
         5247 
         5248   return false;
         5249 } /* group_match_null_string_p */
         5250 
         5251 
         5252 /* Similar to group_match_null_string_p, but doesn't deal with alternatives:
         5253    It expects P to be the first byte of a single alternative and END one
         5254    byte past the last. The alternative can contain groups.  */
         5255 
         5256 static boolean
         5257 alt_match_null_string_p (p, end, reg_info)
         5258     unsigned char *p, *end;
         5259     register_info_type *reg_info;
         5260 {
         5261   int mcnt;
         5262   unsigned char *p1 = p;
         5263 
         5264   while (p1 < end)
         5265     {
         5266       /* Skip over opcodes that can match nothing, and break when we get
         5267          to one that can't.  */
         5268 
         5269       switch ((re_opcode_t) *p1)
         5270         {
         5271         /* It's a loop.  */
         5272         case on_failure_jump:
         5273           p1++;
         5274           EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         5275           p1 += mcnt;
         5276           break;
         5277 
         5278         default:
         5279           if (!common_op_match_null_string_p (&p1, end, reg_info))
         5280             return false;
         5281         }
         5282     }  /* while p1 < end */
         5283 
         5284   return true;
         5285 } /* alt_match_null_string_p */
         5286 
         5287 
         5288 /* Deals with the ops common to group_match_null_string_p and
         5289    alt_match_null_string_p.
         5290 
         5291    Sets P to one after the op and its arguments, if any.  */
         5292 
         5293 static boolean
         5294 common_op_match_null_string_p (p, end, reg_info)
         5295     unsigned char **p, *end;
         5296     register_info_type *reg_info;
         5297 {
         5298   int mcnt;
         5299   boolean ret;
         5300   int reg_no;
         5301   unsigned char *p1 = *p;
         5302 
         5303   switch ((re_opcode_t) *p1++)
         5304     {
         5305     case no_op:
         5306     case begline:
         5307     case endline:
         5308     case begbuf:
         5309     case endbuf:
         5310     case wordbeg:
         5311     case wordend:
         5312     case wordbound:
         5313     case notwordbound:
         5314 #ifdef emacs
         5315     case before_dot:
         5316     case at_dot:
         5317     case after_dot:
         5318 #endif
         5319       break;
         5320 
         5321     case start_memory:
         5322       reg_no = *p1;
         5323       assert (reg_no > 0 && reg_no <= MAX_REGNUM);
         5324       ret = group_match_null_string_p (&p1, end, reg_info);
         5325 
         5326       /* Have to set this here in case we're checking a group which
         5327          contains a group and a back reference to it.  */
         5328 
         5329       if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
         5330         REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
         5331 
         5332       if (!ret)
         5333         return false;
         5334       break;
         5335 
         5336     /* If this is an optimized succeed_n for zero times, make the jump.  */
         5337     case jump:
         5338       EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         5339       if (mcnt >= 0)
         5340         p1 += mcnt;
         5341       else
         5342         return false;
         5343       break;
         5344 
         5345     case succeed_n:
         5346       /* Get to the number of times to succeed.  */
         5347       p1 += 2;
         5348       EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         5349 
         5350       if (mcnt == 0)
         5351         {
         5352           p1 -= 4;
         5353           EXTRACT_NUMBER_AND_INCR (mcnt, p1);
         5354           p1 += mcnt;
         5355         }
         5356       else
         5357         return false;
         5358       break;
         5359 
         5360     case duplicate:
         5361       if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
         5362         return false;
         5363       break;
         5364 
         5365     case set_number_at:
         5366       p1 += 4;
         5367 
         5368     default:
         5369       /* All other opcodes mean we cannot match the empty string.  */
         5370       return false;
         5371   }
         5372 
         5373   *p = p1;
         5374   return true;
         5375 } /* common_op_match_null_string_p */
         5376 
         5377 
         5378 /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
         5379    bytes; nonzero otherwise.  */
         5380 
         5381 static int
         5382 bcmp_translate (s1, s2, len, translate)
         5383      const char *s1, *s2;
         5384      register int len;
         5385      RE_TRANSLATE_TYPE translate;
         5386 {
         5387   register const unsigned char *p1 = (const unsigned char *) s1;
         5388   register const unsigned char *p2 = (const unsigned char *) s2;
         5389   while (len)
         5390     {
         5391       if (translate[*p1++] != translate[*p2++]) return 1;
         5392       len--;
         5393     }
         5394   return 0;
         5395 }
         5396 
         5397 /* Entry points for GNU code.  */
         5398 
         5399 /* re_compile_pattern is the GNU regular expression compiler: it
         5400    compiles PATTERN (of length SIZE) and puts the result in BUFP.
         5401    Returns 0 if the pattern was valid, otherwise an error string.
         5402 
         5403    Assumes the `allocated' (and perhaps `buffer') and `translate' fields
         5404    are set in BUFP on entry.
         5405 
         5406    We call regex_compile to do the actual compilation.  */
         5407 
         5408 const char *
         5409 re_compile_pattern (pattern, length, bufp)
         5410      const char *pattern;
         5411      size_t length;
         5412      struct re_pattern_buffer *bufp;
         5413 {
         5414   reg_errcode_t ret;
         5415 
         5416   /* GNU code is written to assume at least RE_NREGS registers will be set
         5417      (and at least one extra will be -1).  */
         5418   bufp->regs_allocated = REGS_UNALLOCATED;
         5419 
         5420   /* And GNU code determines whether or not to get register information
         5421      by passing null for the REGS argument to re_match, etc., not by
         5422      setting no_sub.  */
         5423   bufp->no_sub = 0;
         5424 
         5425   /* Match anchors at newline.  */
         5426   bufp->newline_anchor = 1;
         5427 
         5428   ret = regex_compile (pattern, length, re_syntax_options, bufp);
         5429 
         5430   if (!ret)
         5431     return NULL;
         5432   return gettext (re_error_msgid[(int) ret]);
         5433 }
         5434 
         5435 /* Entry points compatible with 4.2 BSD regex library.  We don't define
         5436    them unless specifically requested.  */
         5437 
         5438 #if defined (_REGEX_RE_COMP) || defined (_LIBC)
         5439 
         5440 /* BSD has one and only one pattern buffer.  */
         5441 static struct re_pattern_buffer re_comp_buf;
         5442 
         5443 char *
         5444 #ifdef _LIBC
         5445 /* Make these definitions weak in libc, so POSIX programs can redefine
         5446    these names if they don't use our functions, and still use
         5447    regcomp/regexec below without link errors.  */
         5448 weak_function
         5449 #endif
         5450 re_comp (s)
         5451     const char *s;
         5452 {
         5453   reg_errcode_t ret;
         5454 
         5455   if (!s)
         5456     {
         5457       if (!re_comp_buf.buffer)
         5458         return gettext ("No previous regular expression");
         5459       return 0;
         5460     }
         5461 
         5462   if (!re_comp_buf.buffer)
         5463     {
         5464       re_comp_buf.buffer = (unsigned char *) malloc (200);
         5465       if (re_comp_buf.buffer == NULL)
         5466         return gettext (re_error_msgid[(int) REG_ESPACE]);
         5467       re_comp_buf.allocated = 200;
         5468 
         5469       re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
         5470       if (re_comp_buf.fastmap == NULL)
         5471         return gettext (re_error_msgid[(int) REG_ESPACE]);
         5472     }
         5473 
         5474   /* Since `re_exec' always passes NULL for the `regs' argument, we
         5475      don't need to initialize the pattern buffer fields which affect it.  */
         5476 
         5477   /* Match anchors at newlines.  */
         5478   re_comp_buf.newline_anchor = 1;
         5479 
         5480   ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
         5481 
         5482   if (!ret)
         5483     return NULL;
         5484 
         5485   /* Yes, we're discarding `const' here if !HAVE_LIBINTL.  */
         5486   return (char *) gettext (re_error_msgid[(int) ret]);
         5487 }
         5488 
         5489 
         5490 int
         5491 #ifdef _LIBC
         5492 weak_function
         5493 #endif
         5494 re_exec (s)
         5495     const char *s;
         5496 {
         5497   const int len = strlen (s);
         5498   return
         5499     0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
         5500 }
         5501 
         5502 #endif /* _REGEX_RE_COMP */
         5503 
         5504 /* POSIX.2 functions.  Don't define these for Emacs.  */
         5505 
         5506 #ifndef emacs
         5507 
         5508 /* regcomp takes a regular expression as a string and compiles it.
         5509 
         5510    PREG is a regex_t *.  We do not expect any fields to be initialized,
         5511    since POSIX says we shouldn't.  Thus, we set
         5512 
         5513      `buffer' to the compiled pattern;
         5514      `used' to the length of the compiled pattern;
         5515      `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
         5516        REG_EXTENDED bit in CFLAGS is set; otherwise, to
         5517        RE_SYNTAX_POSIX_BASIC;
         5518      `newline_anchor' to REG_NEWLINE being set in CFLAGS;
         5519      `fastmap' and `fastmap_accurate' to zero;
         5520      `re_nsub' to the number of subexpressions in PATTERN.
         5521 
         5522    PATTERN is the address of the pattern string.
         5523 
         5524    CFLAGS is a series of bits which affect compilation.
         5525 
         5526      If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
         5527      use POSIX basic syntax.
         5528 
         5529      If REG_NEWLINE is set, then . and [^...] don't match newline.
         5530      Also, regexec will try a match beginning after every newline.
         5531 
         5532      If REG_ICASE is set, then we considers upper- and lowercase
         5533      versions of letters to be equivalent when matching.
         5534 
         5535      If REG_NOSUB is set, then when PREG is passed to regexec, that
         5536      routine will report only success or failure, and nothing about the
         5537      registers.
         5538 
         5539    It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
         5540    the return codes and their meanings.)  */
         5541 
         5542 #ifdef __APPLE__
         5543 __private_extern__
         5544 #endif
         5545 int
         5546 regcomp (preg, pattern, cflags)
         5547     regex_t *preg;
         5548     const char *pattern;
         5549     int cflags;
         5550 {
         5551   reg_errcode_t ret;
         5552   reg_syntax_t syntax
         5553     = (cflags & REG_EXTENDED) ?
         5554       RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
         5555 
         5556   /* regex_compile will allocate the space for the compiled pattern.  */
         5557   preg->buffer = 0;
         5558   preg->allocated = 0;
         5559   preg->used = 0;
         5560 
         5561   /* Don't bother to use a fastmap when searching.  This simplifies the
         5562      REG_NEWLINE case: if we used a fastmap, we'd have to put all the
         5563      characters after newlines into the fastmap.  This way, we just try
         5564      every character.  */
         5565   preg->fastmap = 0;
         5566 
         5567   if (cflags & REG_ICASE)
         5568     {
         5569       unsigned i;
         5570 
         5571       preg->translate
         5572         = (RE_TRANSLATE_TYPE) malloc (CHAR_SET_SIZE
         5573                                       * sizeof (*(RE_TRANSLATE_TYPE)0));
         5574       if (preg->translate == NULL)
         5575         return (int) REG_ESPACE;
         5576 
         5577       /* Map uppercase characters to corresponding lowercase ones.  */
         5578       for (i = 0; i < CHAR_SET_SIZE; i++)
         5579         preg->translate[i] = ISUPPER (i) ? tolower (i) : i;
         5580     }
         5581   else
         5582     preg->translate = NULL;
         5583 
         5584   /* If REG_NEWLINE is set, newlines are treated differently.  */
         5585   if (cflags & REG_NEWLINE)
         5586     { /* REG_NEWLINE implies neither . nor [^...] match newline.  */
         5587       syntax &= ~RE_DOT_NEWLINE;
         5588       syntax |= RE_HAT_LISTS_NOT_NEWLINE;
         5589       /* It also changes the matching behavior.  */
         5590       preg->newline_anchor = 1;
         5591     }
         5592   else
         5593     preg->newline_anchor = 0;
         5594 
         5595   preg->no_sub = !!(cflags & REG_NOSUB);
         5596 
         5597   /* POSIX says a null character in the pattern terminates it, so we
         5598      can use strlen here in compiling the pattern.  */
         5599   ret = regex_compile (pattern, strlen (pattern), syntax, preg);
         5600 
         5601   /* POSIX doesn't distinguish between an unmatched open-group and an
         5602      unmatched close-group: both are REG_EPAREN.  */
         5603   if (ret == REG_ERPAREN) ret = REG_EPAREN;
         5604 
         5605   return (int) ret;
         5606 }
         5607 
         5608 
         5609 /* regexec searches for a given pattern, specified by PREG, in the
         5610    string STRING.
         5611 
         5612    If NMATCH is zero or REG_NOSUB was set in the cflags argument to
         5613    `regcomp', we ignore PMATCH.  Otherwise, we assume PMATCH has at
         5614    least NMATCH elements, and we set them to the offsets of the
         5615    corresponding matched substrings.
         5616 
         5617    EFLAGS specifies `execution flags' which affect matching: if
         5618    REG_NOTBOL is set, then ^ does not match at the beginning of the
         5619    string; if REG_NOTEOL is set, then $ does not match at the end.
         5620 
         5621    We return 0 if we find a match and REG_NOMATCH if not.  */
         5622 
         5623 #ifdef __APPLE__
         5624 __private_extern__
         5625 #endif
         5626 int
         5627 regexec (preg, string, nmatch, pmatch, eflags)
         5628     const regex_t *preg;
         5629     const char *string;
         5630     size_t nmatch;
         5631     regmatch_t pmatch[];
         5632     int eflags;
         5633 {
         5634   int ret;
         5635   struct re_registers regs;
         5636   regex_t private_preg;
         5637   int len = strlen (string);
         5638   boolean want_reg_info = !preg->no_sub && nmatch > 0;
         5639 
         5640   private_preg = *preg;
         5641 
         5642   private_preg.not_bol = !!(eflags & REG_NOTBOL);
         5643   private_preg.not_eol = !!(eflags & REG_NOTEOL);
         5644 
         5645   /* The user has told us exactly how many registers to return
         5646      information about, via `nmatch'.  We have to pass that on to the
         5647      matching routines.  */
         5648   private_preg.regs_allocated = REGS_FIXED;
         5649 
         5650   if (want_reg_info)
         5651     {
         5652       regs.num_regs = nmatch;
         5653       regs.start = TALLOC (nmatch, regoff_t);
         5654       regs.end = TALLOC (nmatch, regoff_t);
         5655       if (regs.start == NULL || regs.end == NULL)
         5656         return (int) REG_NOMATCH;
         5657     }
         5658 
         5659   /* Perform the searching operation.  */
         5660   ret = re_search (&private_preg, string, len,
         5661                    /* start: */ 0, /* range: */ len,
         5662                    want_reg_info ? &regs : (struct re_registers *) 0);
         5663 
         5664   /* Copy the register information to the POSIX structure.  */
         5665   if (want_reg_info)
         5666     {
         5667       if (ret >= 0)
         5668         {
         5669           unsigned r;
         5670 
         5671           for (r = 0; r < nmatch; r++)
         5672             {
         5673               pmatch[r].rm_so = regs.start[r];
         5674               pmatch[r].rm_eo = regs.end[r];
         5675             }
         5676         }
         5677 
         5678       /* If we needed the temporary register info, free the space now.  */
         5679       free (regs.start);
         5680       free (regs.end);
         5681     }
         5682 
         5683   /* We want zero return to mean success, unlike `re_search'.  */
         5684   return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
         5685 }
         5686 
         5687 
         5688 /* Returns a message corresponding to an error code, ERRCODE, returned
         5689    from either regcomp or regexec.   We don't use PREG here.  */
         5690 
         5691 size_t
         5692 regerror (errcode, preg, errbuf, errbuf_size)
         5693     int errcode;
         5694     const regex_t *preg;
         5695     char *errbuf;
         5696     size_t errbuf_size;
         5697 {
         5698   const char *msg;
         5699   size_t msg_size;
         5700 
         5701   if (errcode < 0
         5702       || errcode >= (int) (sizeof (re_error_msgid)
         5703                            / sizeof (re_error_msgid[0])))
         5704     /* Only error codes returned by the rest of the code should be passed
         5705        to this routine.  If we are given anything else, or if other regex
         5706        code generates an invalid error code, then the program has a bug.
         5707        Dump core so we can fix it.  */
         5708     abort ();
         5709 
         5710   msg = gettext (re_error_msgid[errcode]);
         5711 
         5712   msg_size = strlen (msg) + 1; /* Includes the null.  */
         5713 
         5714   if (errbuf_size != 0)
         5715     {
         5716       if (msg_size > errbuf_size)
         5717         {
         5718           strncpy (errbuf, msg, errbuf_size - 1);
         5719           errbuf[errbuf_size - 1] = 0;
         5720         }
         5721       else
         5722         strcpy (errbuf, msg);
         5723     }
         5724 
         5725   return msg_size;
         5726 }
         5727 
         5728 
         5729 /* Free dynamically allocated space used by PREG.  */
         5730 
         5731 #ifdef __APPLE__
         5732 __private_extern__
         5733 #endif
         5734 void
         5735 regfree (preg)
         5736     regex_t *preg;
         5737 {
         5738   if (preg->buffer != NULL)
         5739     free (preg->buffer);
         5740   preg->buffer = NULL;
         5741 
         5742   preg->allocated = 0;
         5743   preg->used = 0;
         5744 
         5745   if (preg->fastmap != NULL)
         5746     free (preg->fastmap);
         5747   preg->fastmap = NULL;
         5748   preg->fastmap_accurate = 0;
         5749 
         5750   if (preg->translate != NULL)
         5751     free (preg->translate);
         5752   preg->translate = NULL;
         5753 }
         5754 
         5755 #endif /* not emacs  */