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[Emacs-diffs] Changes to emacs/src/regex.c [emacs-unicode-2]


From: Kenichi Handa
Subject: [Emacs-diffs] Changes to emacs/src/regex.c [emacs-unicode-2]
Date: Mon, 08 Sep 2003 08:49:27 -0400

Index: emacs/src/regex.c
diff -c /dev/null emacs/src/regex.c:1.186.4.1
*** /dev/null   Mon Sep  8 08:49:26 2003
--- emacs/src/regex.c   Mon Sep  8 08:48:12 2003
***************
*** 0 ****
--- 1,6476 ----
+ /* Extended regular expression matching and search library, version
+    0.12.  (Implements POSIX draft P1003.2/D11.2, except for some of the
+    internationalization features.)
+ 
+    Copyright (C) 1993,94,95,96,97,98,99,2000 Free Software Foundation, Inc.
+ 
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2, or (at your option)
+    any later version.
+ 
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.        See the
+    GNU General Public License for more details.
+ 
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+    USA.        */
+ 
+ /* TODO:
+    - structure the opcode space into opcode+flag.
+    - merge with glibc's regex.[ch].
+    - replace (succeed_n + jump_n + set_number_at) with something that doesn't
+      need to modify the compiled regexp so that re_match can be reentrant.
+    - get rid of on_failure_jump_smart by doing the optimization in re_comp
+      rather than at run-time, so that re_match can be reentrant.
+ */
+ 
+ /* AIX requires this to be the first thing in the file. */
+ #if defined _AIX && !defined REGEX_MALLOC
+   #pragma alloca
+ #endif
+ 
+ #ifdef HAVE_CONFIG_H
+ # include <config.h>
+ #endif
+ 
+ #if defined STDC_HEADERS && !defined emacs
+ # include <stddef.h>
+ #else
+ /* We need this for `regex.h', and perhaps for the Emacs include files.  */
+ # include <sys/types.h>
+ #endif
+ 
+ /* Whether to use ISO C Amendment 1 wide char functions.
+    Those should not be used for Emacs since it uses its own.  */
+ #if defined _LIBC
+ #define WIDE_CHAR_SUPPORT 1
+ #else
+ #define WIDE_CHAR_SUPPORT \
+       (HAVE_WCTYPE_H && HAVE_WCHAR_H && HAVE_BTOWC && !emacs)
+ #endif
+ 
+ /* For platform which support the ISO C amendement 1 functionality we
+    support user defined character classes.  */
+ #if WIDE_CHAR_SUPPORT
+ /* Solaris 2.5 has a bug: <wchar.h> must be included before <wctype.h>.  */
+ # include <wchar.h>
+ # include <wctype.h>
+ #endif
+ 
+ #ifdef _LIBC
+ /* We have to keep the namespace clean.  */
+ # define regfree(preg) __regfree (preg)
+ # define regexec(pr, st, nm, pm, ef) __regexec (pr, st, nm, pm, ef)
+ # define regcomp(preg, pattern, cflags) __regcomp (preg, pattern, cflags)
+ # define regerror(errcode, preg, errbuf, errbuf_size) \
+       __regerror(errcode, preg, errbuf, errbuf_size)
+ # define re_set_registers(bu, re, nu, st, en) \
+       __re_set_registers (bu, re, nu, st, en)
+ # define re_match_2(bufp, string1, size1, string2, size2, pos, regs, stop) \
+       __re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
+ # define re_match(bufp, string, size, pos, regs) \
+       __re_match (bufp, string, size, pos, regs)
+ # define re_search(bufp, string, size, startpos, range, regs) \
+       __re_search (bufp, string, size, startpos, range, regs)
+ # define re_compile_pattern(pattern, length, bufp) \
+       __re_compile_pattern (pattern, length, bufp)
+ # define re_set_syntax(syntax) __re_set_syntax (syntax)
+ # define re_search_2(bufp, st1, s1, st2, s2, startpos, range, regs, stop) \
+       __re_search_2 (bufp, st1, s1, st2, s2, startpos, range, regs, stop)
+ # define re_compile_fastmap(bufp) __re_compile_fastmap (bufp)
+ 
+ /* Make sure we call libc's function even if the user overrides them.  */
+ # define btowc __btowc
+ # define iswctype __iswctype
+ # define wctype __wctype
+ 
+ # define WEAK_ALIAS(a,b) weak_alias (a, b)
+ 
+ /* We are also using some library internals.  */
+ # include <locale/localeinfo.h>
+ # include <locale/elem-hash.h>
+ # include <langinfo.h>
+ #else
+ # define WEAK_ALIAS(a,b)
+ #endif
+ 
+ /* This is for other GNU distributions with internationalized messages.  */
+ #if HAVE_LIBINTL_H || defined _LIBC
+ # include <libintl.h>
+ #else
+ # define gettext(msgid) (msgid)
+ #endif
+ 
+ #ifndef gettext_noop
+ /* This define is so xgettext can find the internationalizable
+    strings.  */
+ # define gettext_noop(String) String
+ #endif
+ 
+ /* The `emacs' switch turns on certain matching commands
+    that make sense only in Emacs. */
+ #ifdef emacs
+ 
+ # include "lisp.h"
+ # include "buffer.h"
+ 
+ /* Make syntax table lookup grant data in gl_state.  */
+ # define SYNTAX_ENTRY_VIA_PROPERTY
+ 
+ # include "syntax.h"
+ # include "character.h"
+ # include "category.h"
+ 
+ # ifdef malloc
+ #  undef malloc
+ # endif
+ # define malloc xmalloc
+ # ifdef realloc
+ #  undef realloc
+ # endif
+ # define realloc xrealloc
+ # ifdef free
+ #  undef free
+ # endif
+ # define free xfree
+ 
+ /* Converts the pointer to the char to BEG-based offset from the start.       
 */
+ # define PTR_TO_OFFSET(d) POS_AS_IN_BUFFER (POINTER_TO_OFFSET (d))
+ # define POS_AS_IN_BUFFER(p) ((p) + (NILP (re_match_object) || BUFFERP 
(re_match_object)))
+ 
+ # define RE_MULTIBYTE_P(bufp) ((bufp)->multibyte)
+ # define RE_TARGET_MULTIBYTE_P(bufp) ((bufp)->target_multibyte)
+ # define RE_STRING_CHAR(p, s) \
+   (multibyte ? (STRING_CHAR (p, s)) : (*(p)))
+ # define RE_STRING_CHAR_AND_LENGTH(p, s, len) \
+   (multibyte ? (STRING_CHAR_AND_LENGTH (p, s, len)) : ((len) = 1, *(p)))
+ 
+ /* Set C a (possibly converted to multibyte) character before P.  P
+    points into a string which is the virtual concatenation of STR1
+    (which ends at END1) or STR2 (which ends at END2).  */
+ # define GET_CHAR_BEFORE_2(c, p, str1, end1, str2, end2)                   \
+   do {                                                                        
     \
+     if (multibyte)                                                         \
+       {                                                                       
     \
+       re_char *dtemp = (p) == (str2) ? (end1) : (p);                       \
+       re_char *dlimit = ((p) > (str2) && (p) <= (end2)) ? (str2) : (str1); \
+       while (dtemp-- > dlimit && !CHAR_HEAD_P (*dtemp));                   \
+       c = STRING_CHAR (dtemp, (p) - dtemp);                                \
+       }                                                                       
     \
+     else                                                                   \
+       {                                                                       
     \
+       (c = ((p) == (str2) ? (end1) : (p))[-1]);                            \
+       MAKE_CHAR_MULTIBYTE (c);                                             \
+       }                                                                       
     \
+   } while (0)
+ 
+ /* Set C a (possibly converted to multibyte) character at P, and set
+    LEN to the byte length of that character.  */
+ # define GET_CHAR_AFTER(c, p, len)            \
+   do {                                                \
+     if (multibyte)                            \
+       c = STRING_CHAR_AND_LENGTH (p, 0, len); \
+     else                                      \
+       {                                               \
+       c = *p;                                 \
+       len = 1;                                \
+       MAKE_CHAR_MULTIBYTE (c);                \
+       }                                               \
+    } while (0)
+ 
+ #else  /* not emacs */
+ 
+ /* If we are not linking with Emacs proper,
+    we can't use the relocating allocator
+    even if config.h says that we can.  */
+ # undef REL_ALLOC
+ 
+ # if defined STDC_HEADERS || defined _LIBC
+ #  include <stdlib.h>
+ # else
+ char *malloc ();
+ char *realloc ();
+ # endif
+ 
+ /* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
+    If nothing else has been done, use the method below.  */
+ # ifdef INHIBIT_STRING_HEADER
+ #  if !(defined HAVE_BZERO && defined HAVE_BCOPY)
+ #   if !defined bzero && !defined bcopy
+ #    undef INHIBIT_STRING_HEADER
+ #   endif
+ #  endif
+ # endif
+ 
+ /* This is the normal way of making sure we have memcpy, memcmp and bzero.
+    This is used in most programs--a few other programs avoid this
+    by defining INHIBIT_STRING_HEADER.  */
+ # ifndef INHIBIT_STRING_HEADER
+ #  if defined HAVE_STRING_H || defined STDC_HEADERS || defined _LIBC
+ #   include <string.h>
+ #   ifndef bzero
+ #    ifndef _LIBC
+ #     define bzero(s, n)      (memset (s, '\0', n), (s))
+ #    else
+ #     define bzero(s, n)      __bzero (s, n)
+ #    endif
+ #   endif
+ #  else
+ #   include <strings.h>
+ #   ifndef memcmp
+ #    define memcmp(s1, s2, n) bcmp (s1, s2, n)
+ #   endif
+ #   ifndef memcpy
+ #    define memcpy(d, s, n)   (bcopy (s, d, n), (d))
+ #   endif
+ #  endif
+ # endif
+ 
+ /* Define the syntax stuff for \<, \>, etc.  */
+ 
+ /* Sword must be nonzero for the wordchar pattern commands in re_match_2.  */
+ enum syntaxcode { Swhitespace = 0, Sword = 1 };
+ 
+ # ifdef SWITCH_ENUM_BUG
+ #  define SWITCH_ENUM_CAST(x) ((int)(x))
+ # else
+ #  define SWITCH_ENUM_CAST(x) (x)
+ # endif
+ 
+ /* Dummy macros for non-Emacs environments.  */
+ # define BASE_LEADING_CODE_P(c) (0)
+ # define CHAR_CHARSET(c) 0
+ # define CHARSET_LEADING_CODE_BASE(c) 0
+ # define MAX_MULTIBYTE_LENGTH 1
+ # define RE_MULTIBYTE_P(x) 0
+ # define RE_TARGET_MULTIBYTE_P(x) 0
+ # define WORD_BOUNDARY_P(c1, c2) (0)
+ # define CHAR_HEAD_P(p) (1)
+ # define SINGLE_BYTE_CHAR_P(c) (1)
+ # define SAME_CHARSET_P(c1, c2) (1)
+ # define MULTIBYTE_FORM_LENGTH(p, s) (1)
+ # define PREV_CHAR_BOUNDARY(p, limit) ((p)--)
+ # define STRING_CHAR(p, s) (*(p))
+ # define RE_STRING_CHAR STRING_CHAR
+ # define CHAR_STRING(c, s) (*(s) = (c), 1)
+ # define STRING_CHAR_AND_LENGTH(p, s, actual_len) ((actual_len) = 1, *(p))
+ # define RE_STRING_CHAR_AND_LENGTH STRING_CHAR_AND_LENGTH
+ # define GET_CHAR_BEFORE_2(c, p, str1, end1, str2, end2) \
+   (c = ((p) == (str2) ? *((end1) - 1) : *((p) - 1)))
+ # define GET_CHAR_AFTER(c, p, len)    \
+   (c = *p, len = 1)
+ # define MAKE_CHAR(charset, c1, c2) (c1)
+ # define BYTE8_TO_CHAR(c) (c)
+ # define CHAR_BYTE8_P(c) (0)
+ # define MAKE_CHAR_MULTIBYTE(c) (c)
+ # define MAKE_CHAR_UNIBYTE(c) (c)
+ # define CHAR_LEADING_CODE(c) (c)
+ 
+ #endif /* not emacs */
+ 
+ #ifndef RE_TRANSLATE
+ # define RE_TRANSLATE(TBL, C) ((unsigned char)(TBL)[C])
+ # define RE_TRANSLATE_P(TBL) (TBL)
+ #endif
+ 
+ /* Get the interface, including the syntax bits.  */
+ #include "regex.h"
+ 
+ /* isalpha etc. are used for the character classes.  */
+ #include <ctype.h>
+ 
+ #ifdef emacs
+ 
+ /* 1 if C is an ASCII character.  */
+ # define IS_REAL_ASCII(c) ((c) < 0200)
+ 
+ /* 1 if C is a unibyte character.  */
+ # define ISUNIBYTE(c) (SINGLE_BYTE_CHAR_P ((c)))
+ 
+ /* The Emacs definitions should not be directly affected by locales.  */
+ 
+ /* In Emacs, these are only used for single-byte characters.  */
+ # define ISDIGIT(c) ((c) >= '0' && (c) <= '9')
+ # define ISCNTRL(c) ((c) < ' ')
+ # define ISXDIGIT(c) (((c) >= '0' && (c) <= '9')              \
+                    || ((c) >= 'a' && (c) <= 'f')      \
+                    || ((c) >= 'A' && (c) <= 'F'))
+ 
+ /* This is only used for single-byte characters.  */
+ # define ISBLANK(c) ((c) == ' ' || (c) == '\t')
+ 
+ /* The rest must handle multibyte characters.  */
+ 
+ # define ISGRAPH(c) (SINGLE_BYTE_CHAR_P (c)                           \
+                   ? (c) > ' ' && !((c) >= 0177 && (c) <= 0237)        \
+                   : 1)
+ 
+ # define ISPRINT(c) (SINGLE_BYTE_CHAR_P (c)                           \
+                   ? (c) >= ' ' && !((c) >= 0177 && (c) <= 0237)       \
+                   : 1)
+ 
+ # define ISALNUM(c) (IS_REAL_ASCII (c)                        \
+                   ? (((c) >= 'a' && (c) <= 'z')       \
+                      || ((c) >= 'A' && (c) <= 'Z')    \
+                      || ((c) >= '0' && (c) <= '9'))   \
+                   : SYNTAX (c) == Sword)
+ 
+ # define ISALPHA(c) (IS_REAL_ASCII (c)                        \
+                   ? (((c) >= 'a' && (c) <= 'z')       \
+                      || ((c) >= 'A' && (c) <= 'Z'))   \
+                   : SYNTAX (c) == Sword)
+ 
+ # define ISLOWER(c) (LOWERCASEP (c))
+ 
+ # define ISPUNCT(c) (IS_REAL_ASCII (c)                                \
+                   ? ((c) > ' ' && (c) < 0177                  \
+                      && !(((c) >= 'a' && (c) <= 'z')          \
+                           || ((c) >= 'A' && (c) <= 'Z')       \
+                           || ((c) >= '0' && (c) <= '9')))     \
+                   : SYNTAX (c) != Sword)
+ 
+ # define ISSPACE(c) (SYNTAX (c) == Swhitespace)
+ 
+ # define ISUPPER(c) (UPPERCASEP (c))
+ 
+ # define ISWORD(c) (SYNTAX (c) == Sword)
+ 
+ #else /* not emacs */
+ 
+ /* Jim Meyering writes:
+ 
+    "... Some ctype macros are valid only for character codes that
+    isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
+    using /bin/cc or gcc but without giving an ansi option).  So, all
+    ctype uses should be through macros like ISPRINT...  If
+    STDC_HEADERS is defined, then autoconf has verified that the ctype
+    macros don't need to be guarded with references to isascii. ...
+    Defining isascii to 1 should let any compiler worth its salt
+    eliminate the && through constant folding."
+    Solaris defines some of these symbols so we must undefine them first.  */
+ 
+ # undef ISASCII
+ # if defined STDC_HEADERS || (!defined isascii && !defined HAVE_ISASCII)
+ #  define ISASCII(c) 1
+ # else
+ #  define ISASCII(c) isascii(c)
+ # endif
+ 
+ /* 1 if C is an ASCII character.  */
+ # define IS_REAL_ASCII(c) ((c) < 0200)
+ 
+ /* This distinction is not meaningful, except in Emacs.  */
+ # define ISUNIBYTE(c) 1
+ 
+ # ifdef isblank
+ #  define ISBLANK(c) (ISASCII (c) && isblank (c))
+ # else
+ #  define ISBLANK(c) ((c) == ' ' || (c) == '\t')
+ # endif
+ # ifdef isgraph
+ #  define ISGRAPH(c) (ISASCII (c) && isgraph (c))
+ # else
+ #  define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
+ # endif
+ 
+ # undef ISPRINT
+ # define ISPRINT(c) (ISASCII (c) && isprint (c))
+ # define ISDIGIT(c) (ISASCII (c) && isdigit (c))
+ # define ISALNUM(c) (ISASCII (c) && isalnum (c))
+ # define ISALPHA(c) (ISASCII (c) && isalpha (c))
+ # define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
+ # define ISLOWER(c) (ISASCII (c) && islower (c))
+ # define ISPUNCT(c) (ISASCII (c) && ispunct (c))
+ # define ISSPACE(c) (ISASCII (c) && isspace (c))
+ # define ISUPPER(c) (ISASCII (c) && isupper (c))
+ # define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
+ 
+ # define ISWORD(c) ISALPHA(c)
+ 
+ # ifdef _tolower
+ #  define TOLOWER(c) _tolower(c)
+ # else
+ #  define TOLOWER(c) tolower(c)
+ # endif
+ 
+ /* How many characters in the character set.  */
+ # define CHAR_SET_SIZE 256
+ 
+ # ifdef SYNTAX_TABLE
+ 
+ extern char *re_syntax_table;
+ 
+ # else /* not SYNTAX_TABLE */
+ 
+ static char re_syntax_table[CHAR_SET_SIZE];
+ 
+ static void
+ init_syntax_once ()
+ {
+    register int c;
+    static int done = 0;
+ 
+    if (done)
+      return;
+ 
+    bzero (re_syntax_table, sizeof re_syntax_table);
+ 
+    for (c = 0; c < CHAR_SET_SIZE; ++c)
+      if (ISALNUM (c))
+       re_syntax_table[c] = Sword;
+ 
+    re_syntax_table['_'] = Sword;
+ 
+    done = 1;
+ }
+ 
+ # endif /* not SYNTAX_TABLE */
+ 
+ # define SYNTAX(c) re_syntax_table[(c)]
+ 
+ #endif /* not emacs */
+ 
+ #ifndef NULL
+ # define NULL (void *)0
+ #endif
+ 
+ /* We remove any previous definition of `SIGN_EXTEND_CHAR',
+    since ours (we hope) works properly with all combinations of
+    machines, compilers, `char' and `unsigned char' argument types.
+    (Per Bothner suggested the basic approach.)  */
+ #undef SIGN_EXTEND_CHAR
+ #if __STDC__
+ # define SIGN_EXTEND_CHAR(c) ((signed char) (c))
+ #else  /* not __STDC__ */
+ /* As in Harbison and Steele.  */
+ # define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
+ #endif
+ 
+ /* Should we use malloc or alloca?  If REGEX_MALLOC is not defined, we
+    use `alloca' instead of `malloc'.  This is because using malloc in
+    re_search* or re_match* could cause memory leaks when C-g is used in
+    Emacs; also, malloc is slower and causes storage fragmentation.  On
+    the other hand, malloc is more portable, and easier to debug.
+ 
+    Because we sometimes use alloca, some routines have to be macros,
+    not functions -- `alloca'-allocated space disappears at the end of the
+    function it is called in.  */
+ 
+ #ifdef REGEX_MALLOC
+ 
+ # define REGEX_ALLOCATE malloc
+ # define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
+ # define REGEX_FREE free
+ 
+ #else /* not REGEX_MALLOC  */
+ 
+ /* Emacs already defines alloca, sometimes.  */
+ # ifndef alloca
+ 
+ /* Make alloca work the best possible way.  */
+ #  ifdef __GNUC__
+ #   define alloca __builtin_alloca
+ #  else /* not __GNUC__ */
+ #   ifdef HAVE_ALLOCA_H
+ #    include <alloca.h>
+ #   endif /* HAVE_ALLOCA_H */
+ #  endif /* not __GNUC__ */
+ 
+ # endif /* not alloca */
+ 
+ # define REGEX_ALLOCATE alloca
+ 
+ /* Assumes a `char *destination' variable.  */
+ # define REGEX_REALLOCATE(source, osize, nsize)                               
\
+   (destination = (char *) alloca (nsize),                             \
+    memcpy (destination, source, osize))
+ 
+ /* No need to do anything to free, after alloca.  */
+ # define REGEX_FREE(arg) ((void)0) /* Do nothing!  But inhibit gcc warning.  
*/
+ 
+ #endif /* not REGEX_MALLOC */
+ 
+ /* Define how to allocate the failure stack.  */
+ 
+ #if defined REL_ALLOC && defined REGEX_MALLOC
+ 
+ # define REGEX_ALLOCATE_STACK(size)                           \
+   r_alloc (&failure_stack_ptr, (size))
+ # define REGEX_REALLOCATE_STACK(source, osize, nsize)         \
+   r_re_alloc (&failure_stack_ptr, (nsize))
+ # define REGEX_FREE_STACK(ptr)                                        \
+   r_alloc_free (&failure_stack_ptr)
+ 
+ #else /* not using relocating allocator */
+ 
+ # ifdef REGEX_MALLOC
+ 
+ #  define REGEX_ALLOCATE_STACK malloc
+ #  define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
+ #  define REGEX_FREE_STACK free
+ 
+ # else /* not REGEX_MALLOC */
+ 
+ #  define REGEX_ALLOCATE_STACK alloca
+ 
+ #  define REGEX_REALLOCATE_STACK(source, osize, nsize)                        
\
+    REGEX_REALLOCATE (source, osize, nsize)
+ /* No need to explicitly free anything.        */
+ #  define REGEX_FREE_STACK(arg) ((void)0)
+ 
+ # endif /* not REGEX_MALLOC */
+ #endif /* not using relocating allocator */
+ 
+ 
+ /* True if `size1' is non-NULL and PTR is pointing anywhere inside
+    `string1' or just past its end.  This works if PTR is NULL, which is
+    a good thing.  */
+ #define FIRST_STRING_P(ptr)                                   \
+   (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)
+ 
+ /* (Re)Allocate N items of type T using malloc, or fail.  */
+ #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
+ #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
+ #define RETALLOC_IF(addr, n, t) \
+   if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
+ #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))
+ 
+ #define BYTEWIDTH 8 /* In bits.  */
+ 
+ #define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
+ 
+ #undef MAX
+ #undef MIN
+ #define MAX(a, b) ((a) > (b) ? (a) : (b))
+ #define MIN(a, b) ((a) < (b) ? (a) : (b))
+ 
+ /* Type of source-pattern and string chars.  */
+ typedef const unsigned char re_char;
+ 
+ typedef char boolean;
+ #define false 0
+ #define true 1
+ 
+ static int re_match_2_internal _RE_ARGS ((struct re_pattern_buffer *bufp,
+                                       re_char *string1, int size1,
+                                       re_char *string2, int size2,
+                                       int pos,
+                                       struct re_registers *regs,
+                                       int stop));
+ 
+ /* These are the command codes that appear in compiled regular
+    expressions.  Some opcodes are followed by argument bytes.  A
+    command code can specify any interpretation whatsoever for its
+    arguments.  Zero bytes may appear in the compiled regular expression.  */
+ 
+ typedef enum
+ {
+   no_op = 0,
+ 
+   /* Succeed right away--no more backtracking.  */
+   succeed,
+ 
+       /* Followed by one byte giving n, then by n literal bytes.  */
+   exactn,
+ 
+       /* Matches any (more or less) character.  */
+   anychar,
+ 
+       /* Matches any one char belonging to specified set.  First
+          following byte is number of bitmap bytes.  Then come bytes
+          for a bitmap saying which chars are in.  Bits in each byte
+          are ordered low-bit-first.  A character is in the set if its
+          bit is 1.  A character too large to have a bit in the map is
+          automatically not in the set.
+ 
+          If the length byte has the 0x80 bit set, then that stuff
+          is followed by a range table:
+              2 bytes of flags for character sets (low 8 bits, high 8 bits)
+                  See RANGE_TABLE_WORK_BITS below.
+              2 bytes, the number of pairs that follow (upto 32767)
+              pairs, each 2 multibyte characters,
+                  each multibyte character represented as 3 bytes.  */
+   charset,
+ 
+       /* Same parameters as charset, but match any character that is
+          not one of those specified.  */
+   charset_not,
+ 
+       /* Start remembering the text that is matched, for storing in a
+          register.  Followed by one byte with the register number, in
+          the range 0 to one less than the pattern buffer's re_nsub
+          field.  */
+   start_memory,
+ 
+       /* Stop remembering the text that is matched and store it in a
+          memory register.  Followed by one byte with the register
+          number, in the range 0 to one less than `re_nsub' in the
+          pattern buffer.  */
+   stop_memory,
+ 
+       /* Match a duplicate of something remembered. Followed by one
+          byte containing the register number.  */
+   duplicate,
+ 
+       /* Fail unless at beginning of line.  */
+   begline,
+ 
+       /* Fail unless at end of line.  */
+   endline,
+ 
+       /* Succeeds if at beginning of buffer (if emacs) or at beginning
+          of string to be matched (if not).  */
+   begbuf,
+ 
+       /* Analogously, for end of buffer/string.  */
+   endbuf,
+ 
+       /* Followed by two byte relative address to which to jump.  */
+   jump,
+ 
+       /* Followed by two-byte relative address of place to resume at
+          in case of failure.  */
+   on_failure_jump,
+ 
+       /* Like on_failure_jump, but pushes a placeholder instead of the
+          current string position when executed.  */
+   on_failure_keep_string_jump,
+ 
+       /* Just like `on_failure_jump', except that it checks that we
+          don't get stuck in an infinite loop (matching an empty string
+          indefinitely).  */
+   on_failure_jump_loop,
+ 
+       /* Just like `on_failure_jump_loop', except that it checks for
+          a different kind of loop (the kind that shows up with non-greedy
+          operators).  This operation has to be immediately preceded
+          by a `no_op'.  */
+   on_failure_jump_nastyloop,
+ 
+       /* A smart `on_failure_jump' used for greedy * and + operators.
+          It analyses the loop before which it is put and if the
+          loop does not require backtracking, it changes itself to
+          `on_failure_keep_string_jump' and short-circuits the loop,
+          else it just defaults to changing itself into `on_failure_jump'.
+          It assumes that it is pointing to just past a `jump'.  */
+   on_failure_jump_smart,
+ 
+       /* Followed by two-byte relative address and two-byte number n.
+          After matching N times, jump to the address upon failure.
+          Does not work if N starts at 0: use on_failure_jump_loop
+          instead.  */
+   succeed_n,
+ 
+       /* Followed by two-byte relative address, and two-byte number n.
+          Jump to the address N times, then fail.  */
+   jump_n,
+ 
+       /* Set the following two-byte relative address to the
+          subsequent two-byte number.  The address *includes* the two
+          bytes of number.  */
+   set_number_at,
+ 
+   wordbeg,    /* Succeeds if at word beginning.  */
+   wordend,    /* Succeeds if at word end.  */
+ 
+   wordbound,  /* Succeeds if at a word boundary.  */
+   notwordbound,       /* Succeeds if not at a word boundary.  */
+ 
+       /* Matches any character whose syntax is specified.  Followed by
+          a byte which contains a syntax code, e.g., Sword.  */
+   syntaxspec,
+ 
+       /* Matches any character whose syntax is not that specified.  */
+   notsyntaxspec
+ 
+ #ifdef emacs
+   ,before_dot,        /* Succeeds if before point.  */
+   at_dot,     /* Succeeds if at point.  */
+   after_dot,  /* Succeeds if after point.  */
+ 
+   /* Matches any character whose category-set contains the specified
+      category.        The operator is followed by a byte which contains a
+      category code (mnemonic ASCII character).        */
+   categoryspec,
+ 
+   /* Matches any character whose category-set does not contain the
+      specified category.  The operator is followed by a byte which
+      contains the category code (mnemonic ASCII character).  */
+   notcategoryspec
+ #endif /* emacs */
+ } re_opcode_t;
+ 
+ /* Common operations on the compiled pattern.  */
+ 
+ /* Store NUMBER in two contiguous bytes starting at DESTINATION.  */
+ 
+ #define STORE_NUMBER(destination, number)                             \
+   do {                                                                        
\
+     (destination)[0] = (number) & 0377;                                       
\
+     (destination)[1] = (number) >> 8;                                 \
+   } while (0)
+ 
+ /* Same as STORE_NUMBER, except increment DESTINATION to
+    the byte after where the number is stored.  Therefore, DESTINATION
+    must be an lvalue.  */
+ 
+ #define STORE_NUMBER_AND_INCR(destination, number)                    \
+   do {                                                                        
\
+     STORE_NUMBER (destination, number);                                       
\
+     (destination) += 2;                                                       
\
+   } while (0)
+ 
+ /* Put into DESTINATION a number stored in two contiguous bytes starting
+    at SOURCE.  */
+ 
+ #define EXTRACT_NUMBER(destination, source)                           \
+   do {                                                                        
\
+     (destination) = *(source) & 0377;                                 \
+     (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8;         \
+   } while (0)
+ 
+ #ifdef DEBUG
+ static void extract_number _RE_ARGS ((int *dest, re_char *source));
+ static void
+ extract_number (dest, source)
+     int *dest;
+     re_char *source;
+ {
+   int temp = SIGN_EXTEND_CHAR (*(source + 1));
+   *dest = *source & 0377;
+   *dest += temp << 8;
+ }
+ 
+ # ifndef EXTRACT_MACROS /* To debug the macros.  */
+ #  undef EXTRACT_NUMBER
+ #  define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
+ # endif /* not EXTRACT_MACROS */
+ 
+ #endif /* DEBUG */
+ 
+ /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
+    SOURCE must be an lvalue.  */
+ 
+ #define EXTRACT_NUMBER_AND_INCR(destination, source)                  \
+   do {                                                                        
\
+     EXTRACT_NUMBER (destination, source);                             \
+     (source) += 2;                                                    \
+   } while (0)
+ 
+ #ifdef DEBUG
+ static void extract_number_and_incr _RE_ARGS ((int *destination,
+                                              re_char **source));
+ static void
+ extract_number_and_incr (destination, source)
+     int *destination;
+     re_char **source;
+ {
+   extract_number (destination, *source);
+   *source += 2;
+ }
+ 
+ # ifndef EXTRACT_MACROS
+ #  undef EXTRACT_NUMBER_AND_INCR
+ #  define EXTRACT_NUMBER_AND_INCR(dest, src) \
+   extract_number_and_incr (&dest, &src)
+ # endif /* not EXTRACT_MACROS */
+ 
+ #endif /* DEBUG */
+ 
+ /* Store a multibyte character in three contiguous bytes starting
+    DESTINATION, and increment DESTINATION to the byte after where the
+    character is stored.        Therefore, DESTINATION must be an lvalue.  */
+ 
+ #define STORE_CHARACTER_AND_INCR(destination, character)      \
+   do {                                                                \
+     (destination)[0] = (character) & 0377;                    \
+     (destination)[1] = ((character) >> 8) & 0377;             \
+     (destination)[2] = (character) >> 16;                     \
+     (destination) += 3;                                               \
+   } while (0)
+ 
+ /* Put into DESTINATION a character stored in three contiguous bytes
+    starting at SOURCE.        */
+ 
+ #define EXTRACT_CHARACTER(destination, source)        \
+   do {                                                \
+     (destination) = ((source)[0]              \
+                    | ((source)[1] << 8)       \
+                    | ((source)[2] << 16));    \
+   } while (0)
+ 
+ 
+ /* Macros for charset. */
+ 
+ /* Size of bitmap of charset P in bytes.  P is a start of charset,
+    i.e. *P is (re_opcode_t) charset or (re_opcode_t) charset_not.  */
+ #define CHARSET_BITMAP_SIZE(p) ((p)[1] & 0x7F)
+ 
+ /* Nonzero if charset P has range table.  */
+ #define CHARSET_RANGE_TABLE_EXISTS_P(p)        ((p)[1] & 0x80)
+ 
+ /* Return the address of range table of charset P.  But not the start
+    of table itself, but the before where the number of ranges is
+    stored.  `2 +' means to skip re_opcode_t and size of bitmap,
+    and the 2 bytes of flags at the start of the range table.  */
+ #define CHARSET_RANGE_TABLE(p) (&(p)[4 + CHARSET_BITMAP_SIZE (p)])
+ 
+ /* Extract the bit flags that start a range table.  */
+ #define CHARSET_RANGE_TABLE_BITS(p)           \
+   ((p)[2 + CHARSET_BITMAP_SIZE (p)]           \
+    + (p)[3 + CHARSET_BITMAP_SIZE (p)] * 0x100)
+ 
+ /* Test if C is listed in the bitmap of charset P.  */
+ #define CHARSET_LOOKUP_BITMAP(p, c)                           \
+   ((c) < CHARSET_BITMAP_SIZE (p) * BYTEWIDTH                  \
+    && (p)[2 + (c) / BYTEWIDTH] & (1 << ((c) % BYTEWIDTH)))
+ 
+ /* Return the address of end of RANGE_TABLE.  COUNT is number of
+    ranges (which is a pair of (start, end)) in the RANGE_TABLE.        `* 2'
+    is start of range and end of range.        `* 3' is size of each start
+    and end.  */
+ #define CHARSET_RANGE_TABLE_END(range_table, count)   \
+   ((range_table) + (count) * 2 * 3)
+ 
+ /* Test if C is in RANGE_TABLE.        A flag NOT is negated if C is in.
+    COUNT is number of ranges in RANGE_TABLE.  */
+ #define CHARSET_LOOKUP_RANGE_TABLE_RAW(not, c, range_table, count)    \
+   do                                                                  \
+     {                                                                 \
+       re_wchar_t range_start, range_end;                              \
+       re_char *p;                                                     \
+       re_char *range_table_end                                                
\
+       = CHARSET_RANGE_TABLE_END ((range_table), (count));             \
+                                                                       \
+       for (p = (range_table); p < range_table_end; p += 2 * 3)                
\
+       {                                                               \
+         EXTRACT_CHARACTER (range_start, p);                           \
+         EXTRACT_CHARACTER (range_end, p + 3);                         \
+                                                                       \
+         if (range_start <= (c) && (c) <= range_end)                   \
+           {                                                           \
+             (not) = !(not);                                           \
+             break;                                                    \
+           }                                                           \
+       }                                                               \
+     }                                                                 \
+   while (0)
+ 
+ /* Test if C is in range table of CHARSET.  The flag NOT is negated if
+    C is listed in it.  */
+ #define CHARSET_LOOKUP_RANGE_TABLE(not, c, charset)                   \
+   do                                                                  \
+     {                                                                 \
+       /* Number of ranges in range table. */                          \
+       int count;                                                      \
+       re_char *range_table = CHARSET_RANGE_TABLE (charset);           \
+                                                                               
\
+       EXTRACT_NUMBER_AND_INCR (count, range_table);                   \
+       CHARSET_LOOKUP_RANGE_TABLE_RAW ((not), (c), range_table, count);        
\
+     }                                                                 \
+   while (0)
+ 
+ /* If DEBUG is defined, Regex prints many voluminous messages about what
+    it is doing (if the variable `debug' is nonzero).  If linked with the
+    main program in `iregex.c', you can enter patterns and strings
+    interactively.  And if linked with the main program in `main.c' and
+    the other test files, you can run the already-written tests.  */
+ 
+ #ifdef DEBUG
+ 
+ /* We use standard I/O for debugging.  */
+ # include <stdio.h>
+ 
+ /* It is useful to test things that ``must'' be true when debugging.  */
+ # include <assert.h>
+ 
+ static int debug = -100000;
+ 
+ # define DEBUG_STATEMENT(e) e
+ # define DEBUG_PRINT1(x) if (debug > 0) printf (x)
+ # define DEBUG_PRINT2(x1, x2) if (debug > 0) printf (x1, x2)
+ # define DEBUG_PRINT3(x1, x2, x3) if (debug > 0) printf (x1, x2, x3)
+ # define DEBUG_PRINT4(x1, x2, x3, x4) if (debug > 0) printf (x1, x2, x3, x4)
+ # define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)                                
\
+   if (debug > 0) print_partial_compiled_pattern (s, e)
+ # define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)                       
\
+   if (debug > 0) print_double_string (w, s1, sz1, s2, sz2)
+ 
+ 
+ /* Print the fastmap in human-readable form.  */
+ 
+ void
+ print_fastmap (fastmap)
+     char *fastmap;
+ {
+   unsigned was_a_range = 0;
+   unsigned i = 0;
+ 
+   while (i < (1 << BYTEWIDTH))
+     {
+       if (fastmap[i++])
+       {
+         was_a_range = 0;
+         putchar (i - 1);
+         while (i < (1 << BYTEWIDTH)  &&  fastmap[i])
+           {
+             was_a_range = 1;
+             i++;
+           }
+         if (was_a_range)
+           {
+             printf ("-");
+             putchar (i - 1);
+           }
+       }
+     }
+   putchar ('\n');
+ }
+ 
+ 
+ /* Print a compiled pattern string in human-readable form, starting at
+    the START pointer into it and ending just before the pointer END.  */
+ 
+ void
+ print_partial_compiled_pattern (start, end)
+     re_char *start;
+     re_char *end;
+ {
+   int mcnt, mcnt2;
+   re_char *p = start;
+   re_char *pend = end;
+ 
+   if (start == NULL)
+     {
+       fprintf (stderr, "(null)\n");
+       return;
+     }
+ 
+   /* Loop over pattern commands.  */
+   while (p < pend)
+     {
+       fprintf (stderr, "%d:\t", p - start);
+ 
+       switch ((re_opcode_t) *p++)
+       {
+       case no_op:
+         fprintf (stderr, "/no_op");
+         break;
+ 
+       case succeed:
+         fprintf (stderr, "/succeed");
+         break;
+ 
+       case exactn:
+         mcnt = *p++;
+         fprintf (stderr, "/exactn/%d", mcnt);
+         do
+           {
+             fprintf (stderr, "/%c", *p++);
+           }
+         while (--mcnt);
+         break;
+ 
+       case start_memory:
+         fprintf (stderr, "/start_memory/%d", *p++);
+         break;
+ 
+       case stop_memory:
+         fprintf (stderr, "/stop_memory/%d", *p++);
+         break;
+ 
+       case duplicate:
+         fprintf (stderr, "/duplicate/%d", *p++);
+         break;
+ 
+       case anychar:
+         fprintf (stderr, "/anychar");
+         break;
+ 
+       case charset:
+       case charset_not:
+         {
+           register int c, last = -100;
+           register int in_range = 0;
+           int length = CHARSET_BITMAP_SIZE (p - 1);
+           int has_range_table = CHARSET_RANGE_TABLE_EXISTS_P (p - 1);
+ 
+           fprintf (stderr, "/charset [%s",
+                   (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
+ 
+           assert (p + *p < pend);
+ 
+           for (c = 0; c < 256; c++)
+             if (c / 8 < length
+                 && (p[1 + (c/8)] & (1 << (c % 8))))
+               {
+                 /* Are we starting a range?  */
+                 if (last + 1 == c && ! in_range)
+                   {
+                     fprintf (stderr, "-");
+                     in_range = 1;
+                   }
+                 /* Have we broken a range?  */
+                 else if (last + 1 != c && in_range)
+                   {
+                     fprintf (stderr, "%c", last);
+                     in_range = 0;
+                   }
+ 
+                 if (! in_range)
+                   fprintf (stderr, "%c", c);
+ 
+                 last = c;
+             }
+ 
+           if (in_range)
+             fprintf (stderr, "%c", last);
+ 
+           fprintf (stderr, "]");
+ 
+           p += 1 + length;
+ 
+           if (has_range_table)
+             {
+               int count;
+               fprintf (stderr, "has-range-table");
+ 
+               /* ??? Should print the range table; for now, just skip it.  */
+               p += 2;         /* skip range table bits */
+               EXTRACT_NUMBER_AND_INCR (count, p);
+               p = CHARSET_RANGE_TABLE_END (p, count);
+             }
+         }
+         break;
+ 
+       case begline:
+         fprintf (stderr, "/begline");
+         break;
+ 
+       case endline:
+         fprintf (stderr, "/endline");
+         break;
+ 
+       case on_failure_jump:
+         extract_number_and_incr (&mcnt, &p);
+         fprintf (stderr, "/on_failure_jump to %d", p + mcnt - start);
+         break;
+ 
+       case on_failure_keep_string_jump:
+         extract_number_and_incr (&mcnt, &p);
+         fprintf (stderr, "/on_failure_keep_string_jump to %d", p + mcnt - 
start);
+         break;
+ 
+       case on_failure_jump_nastyloop:
+         extract_number_and_incr (&mcnt, &p);
+         fprintf (stderr, "/on_failure_jump_nastyloop to %d", p + mcnt - 
start);
+         break;
+ 
+       case on_failure_jump_loop:
+         extract_number_and_incr (&mcnt, &p);
+         fprintf (stderr, "/on_failure_jump_loop to %d", p + mcnt - start);
+         break;
+ 
+       case on_failure_jump_smart:
+         extract_number_and_incr (&mcnt, &p);
+         fprintf (stderr, "/on_failure_jump_smart to %d", p + mcnt - start);
+         break;
+ 
+       case jump:
+         extract_number_and_incr (&mcnt, &p);
+         fprintf (stderr, "/jump to %d", p + mcnt - start);
+         break;
+ 
+       case succeed_n:
+         extract_number_and_incr (&mcnt, &p);
+         extract_number_and_incr (&mcnt2, &p);
+         fprintf (stderr, "/succeed_n to %d, %d times", p - 2 + mcnt - start, 
mcnt2);
+         break;
+ 
+       case jump_n:
+         extract_number_and_incr (&mcnt, &p);
+         extract_number_and_incr (&mcnt2, &p);
+         fprintf (stderr, "/jump_n to %d, %d times", p - 2 + mcnt - start, 
mcnt2);
+         break;
+ 
+       case set_number_at:
+         extract_number_and_incr (&mcnt, &p);
+         extract_number_and_incr (&mcnt2, &p);
+         fprintf (stderr, "/set_number_at location %d to %d", p - 2 + mcnt - 
start, mcnt2);
+         break;
+ 
+       case wordbound:
+         fprintf (stderr, "/wordbound");
+         break;
+ 
+       case notwordbound:
+         fprintf (stderr, "/notwordbound");
+         break;
+ 
+       case wordbeg:
+         fprintf (stderr, "/wordbeg");
+         break;
+ 
+       case wordend:
+         fprintf (stderr, "/wordend");
+ 
+       case syntaxspec:
+         fprintf (stderr, "/syntaxspec");
+         mcnt = *p++;
+         fprintf (stderr, "/%d", mcnt);
+         break;
+ 
+       case notsyntaxspec:
+         fprintf (stderr, "/notsyntaxspec");
+         mcnt = *p++;
+         fprintf (stderr, "/%d", mcnt);
+         break;
+ 
+ # ifdef emacs
+       case before_dot:
+         fprintf (stderr, "/before_dot");
+         break;
+ 
+       case at_dot:
+         fprintf (stderr, "/at_dot");
+         break;
+ 
+       case after_dot:
+         fprintf (stderr, "/after_dot");
+         break;
+ 
+       case categoryspec:
+         fprintf (stderr, "/categoryspec");
+         mcnt = *p++;
+         fprintf (stderr, "/%d", mcnt);
+         break;
+ 
+       case notcategoryspec:
+         fprintf (stderr, "/notcategoryspec");
+         mcnt = *p++;
+         fprintf (stderr, "/%d", mcnt);
+         break;
+ # endif /* emacs */
+ 
+       case begbuf:
+         fprintf (stderr, "/begbuf");
+         break;
+ 
+       case endbuf:
+         fprintf (stderr, "/endbuf");
+         break;
+ 
+       default:
+         fprintf (stderr, "?%d", *(p-1));
+       }
+ 
+       fprintf (stderr, "\n");
+     }
+ 
+   fprintf (stderr, "%d:\tend of pattern.\n", p - start);
+ }
+ 
+ 
+ void
+ print_compiled_pattern (bufp)
+     struct re_pattern_buffer *bufp;
+ {
+   re_char *buffer = bufp->buffer;
+ 
+   print_partial_compiled_pattern (buffer, buffer + bufp->used);
+   printf ("%ld bytes used/%ld bytes allocated.\n",
+         bufp->used, bufp->allocated);
+ 
+   if (bufp->fastmap_accurate && bufp->fastmap)
+     {
+       printf ("fastmap: ");
+       print_fastmap (bufp->fastmap);
+     }
+ 
+   printf ("re_nsub: %d\t", bufp->re_nsub);
+   printf ("regs_alloc: %d\t", bufp->regs_allocated);
+   printf ("can_be_null: %d\t", bufp->can_be_null);
+   printf ("no_sub: %d\t", bufp->no_sub);
+   printf ("not_bol: %d\t", bufp->not_bol);
+   printf ("not_eol: %d\t", bufp->not_eol);
+   printf ("syntax: %lx\n", bufp->syntax);
+   fflush (stdout);
+   /* Perhaps we should print the translate table?  */
+ }
+ 
+ 
+ void
+ print_double_string (where, string1, size1, string2, size2)
+     re_char *where;
+     re_char *string1;
+     re_char *string2;
+     int size1;
+     int size2;
+ {
+   int this_char;
+ 
+   if (where == NULL)
+     printf ("(null)");
+   else
+     {
+       if (FIRST_STRING_P (where))
+       {
+         for (this_char = where - string1; this_char < size1; this_char++)
+           putchar (string1[this_char]);
+ 
+         where = string2;
+       }
+ 
+       for (this_char = where - string2; this_char < size2; this_char++)
+       putchar (string2[this_char]);
+     }
+ }
+ 
+ #else /* not DEBUG */
+ 
+ # undef assert
+ # define assert(e)
+ 
+ # define DEBUG_STATEMENT(e)
+ # define DEBUG_PRINT1(x)
+ # define DEBUG_PRINT2(x1, x2)
+ # define DEBUG_PRINT3(x1, x2, x3)
+ # define DEBUG_PRINT4(x1, x2, x3, x4)
+ # define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
+ # define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
+ 
+ #endif /* not DEBUG */
+ 
+ /* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
+    also be assigned to arbitrarily: each pattern buffer stores its own
+    syntax, so it can be changed between regex compilations.  */
+ /* This has no initializer because initialized variables in Emacs
+    become read-only after dumping.  */
+ reg_syntax_t re_syntax_options;
+ 
+ 
+ /* Specify the precise syntax of regexps for compilation.  This provides
+    for compatibility for various utilities which historically have
+    different, incompatible syntaxes.
+ 
+    The argument SYNTAX is a bit mask comprised of the various bits
+    defined in regex.h.  We return the old syntax.  */
+ 
+ reg_syntax_t
+ re_set_syntax (syntax)
+     reg_syntax_t syntax;
+ {
+   reg_syntax_t ret = re_syntax_options;
+ 
+   re_syntax_options = syntax;
+   return ret;
+ }
+ WEAK_ALIAS (__re_set_syntax, re_set_syntax)
+ 
+ /* This table gives an error message for each of the error codes listed
+    in regex.h.  Obviously the order here has to be same as there.
+    POSIX doesn't require that we do anything for REG_NOERROR,
+    but why not be nice?  */
+ 
+ static const char *re_error_msgid[] =
+   {
+     gettext_noop ("Success"), /* REG_NOERROR */
+     gettext_noop ("No match"),        /* REG_NOMATCH */
+     gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
+     gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
+     gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
+     gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
+     gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
+     gettext_noop ("Unmatched [ or [^"),       /* REG_EBRACK */
+     gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
+     gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
+     gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
+     gettext_noop ("Invalid range end"),       /* REG_ERANGE */
+     gettext_noop ("Memory exhausted"), /* REG_ESPACE */
+     gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
+     gettext_noop ("Premature end of regular expression"), /* REG_EEND */
+     gettext_noop ("Regular expression too big"), /* REG_ESIZE */
+     gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
+   };
+ 
+ /* Avoiding alloca during matching, to placate r_alloc.  */
+ 
+ /* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
+    searching and matching functions should not call alloca.  On some
+    systems, alloca is implemented in terms of malloc, and if we're
+    using the relocating allocator routines, then malloc could cause a
+    relocation, which might (if the strings being searched are in the
+    ralloc heap) shift the data out from underneath the regexp
+    routines.
+ 
+    Here's another reason to avoid allocation: Emacs
+    processes input from X in a signal handler; processing X input may
+    call malloc; if input arrives while a matching routine is calling
+    malloc, then we're scrod.  But Emacs can't just block input while
+    calling matching routines; then we don't notice interrupts when
+    they come in.  So, Emacs blocks input around all regexp calls
+    except the matching calls, which it leaves unprotected, in the
+    faith that they will not malloc.  */
+ 
+ /* Normally, this is fine.  */
+ #define MATCH_MAY_ALLOCATE
+ 
+ /* When using GNU C, we are not REALLY using the C alloca, no matter
+    what config.h may say.  So don't take precautions for it.  */
+ #ifdef __GNUC__
+ # undef C_ALLOCA
+ #endif
+ 
+ /* The match routines may not allocate if (1) they would do it with malloc
+    and (2) it's not safe for them to use malloc.
+    Note that if REL_ALLOC is defined, matching would not use malloc for the
+    failure stack, but we would still use it for the register vectors;
+    so REL_ALLOC should not affect this.  */
+ #if (defined C_ALLOCA || defined REGEX_MALLOC) && defined emacs
+ # undef MATCH_MAY_ALLOCATE
+ #endif
+ 
+ 
+ /* Failure stack declarations and macros; both re_compile_fastmap and
+    re_match_2 use a failure stack.  These have to be macros because of
+    REGEX_ALLOCATE_STACK.  */
+ 
+ 
+ /* Approximate number of failure points for which to initially allocate space
+    when matching.  If this number is exceeded, we allocate more
+    space, so it is not a hard limit.  */
+ #ifndef INIT_FAILURE_ALLOC
+ # define INIT_FAILURE_ALLOC 20
+ #endif
+ 
+ /* Roughly the maximum number of failure points on the stack.  Would be
+    exactly that if always used TYPICAL_FAILURE_SIZE items each time we failed.
+    This is a variable only so users of regex can assign to it; we never
+    change it ourselves.  We always multiply it by TYPICAL_FAILURE_SIZE
+    before using it, so it should probably be a byte-count instead.  */
+ # if defined MATCH_MAY_ALLOCATE
+ /* Note that 4400 was enough to cause a crash on Alpha OSF/1,
+    whose default stack limit is 2mb.  In order for a larger
+    value to work reliably, you have to try to make it accord
+    with the process stack limit.  */
+ size_t re_max_failures = 40000;
+ # else
+ size_t re_max_failures = 4000;
+ # endif
+ 
+ union fail_stack_elt
+ {
+   re_char *pointer;
+   /* This should be the biggest `int' that's no bigger than a pointer.  */
+   long integer;
+ };
+ 
+ typedef union fail_stack_elt fail_stack_elt_t;
+ 
+ typedef struct
+ {
+   fail_stack_elt_t *stack;
+   size_t size;
+   size_t avail;       /* Offset of next open position.  */
+   size_t frame;       /* Offset of the cur constructed frame.  */
+ } fail_stack_type;
+ 
+ #define FAIL_STACK_EMPTY()     (fail_stack.frame == 0)
+ #define FAIL_STACK_FULL()      (fail_stack.avail == fail_stack.size)
+ 
+ 
+ /* Define macros to initialize and free the failure stack.
+    Do `return -2' if the alloc fails.  */
+ 
+ #ifdef MATCH_MAY_ALLOCATE
+ # define INIT_FAIL_STACK()                                            \
+   do {                                                                        
\
+     fail_stack.stack = (fail_stack_elt_t *)                           \
+       REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * TYPICAL_FAILURE_SIZE \
+                           * sizeof (fail_stack_elt_t));               \
+                                                                       \
+     if (fail_stack.stack == NULL)                                     \
+       return -2;                                                      \
+                                                                       \
+     fail_stack.size = INIT_FAILURE_ALLOC;                             \
+     fail_stack.avail = 0;                                             \
+     fail_stack.frame = 0;                                             \
+   } while (0)
+ 
+ # define RESET_FAIL_STACK()  REGEX_FREE_STACK (fail_stack.stack)
+ #else
+ # define INIT_FAIL_STACK()                                            \
+   do {                                                                        
\
+     fail_stack.avail = 0;                                             \
+     fail_stack.frame = 0;                                             \
+   } while (0)
+ 
+ # define RESET_FAIL_STACK() ((void)0)
+ #endif
+ 
+ 
+ /* Double the size of FAIL_STACK, up to a limit
+    which allows approximately `re_max_failures' items.
+ 
+    Return 1 if succeeds, and 0 if either ran out of memory
+    allocating space for it or it was already too large.
+ 
+    REGEX_REALLOCATE_STACK requires `destination' be declared.   */
+ 
+ /* Factor to increase the failure stack size by
+    when we increase it.
+    This used to be 2, but 2 was too wasteful
+    because the old discarded stacks added up to as much space
+    were as ultimate, maximum-size stack.  */
+ #define FAIL_STACK_GROWTH_FACTOR 4
+ 
+ #define GROW_FAIL_STACK(fail_stack)                                   \
+   (((fail_stack).size * sizeof (fail_stack_elt_t)                     \
+     >= re_max_failures * TYPICAL_FAILURE_SIZE)                                
\
+    ? 0                                                                        
\
+    : ((fail_stack).stack                                              \
+       = (fail_stack_elt_t *)                                          \
+       REGEX_REALLOCATE_STACK ((fail_stack).stack,                     \
+         (fail_stack).size * sizeof (fail_stack_elt_t),                \
+         MIN (re_max_failures * TYPICAL_FAILURE_SIZE,                  \
+              ((fail_stack).size * sizeof (fail_stack_elt_t)           \
+               * FAIL_STACK_GROWTH_FACTOR))),                          \
+                                                                       \
+       (fail_stack).stack == NULL                                      \
+       ? 0                                                             \
+       : ((fail_stack).size                                            \
+        = (MIN (re_max_failures * TYPICAL_FAILURE_SIZE,                \
+                ((fail_stack).size * sizeof (fail_stack_elt_t)         \
+                 * FAIL_STACK_GROWTH_FACTOR))                          \
+           / sizeof (fail_stack_elt_t)),                               \
+        1)))
+ 
+ 
+ /* Push a pointer value onto the failure stack.
+    Assumes the variable `fail_stack'.  Probably should only
+    be called from within `PUSH_FAILURE_POINT'.  */
+ #define PUSH_FAILURE_POINTER(item)                                    \
+   fail_stack.stack[fail_stack.avail++].pointer = (item)
+ 
+ /* This pushes an integer-valued item onto the failure stack.
+    Assumes the variable `fail_stack'.  Probably should only
+    be called from within `PUSH_FAILURE_POINT'.  */
+ #define PUSH_FAILURE_INT(item)                                        \
+   fail_stack.stack[fail_stack.avail++].integer = (item)
+ 
+ /* Push a fail_stack_elt_t value onto the failure stack.
+    Assumes the variable `fail_stack'.  Probably should only
+    be called from within `PUSH_FAILURE_POINT'.  */
+ #define PUSH_FAILURE_ELT(item)                                        \
+   fail_stack.stack[fail_stack.avail++] =  (item)
+ 
+ /* These three POP... operations complement the three PUSH... operations.
+    All assume that `fail_stack' is nonempty.  */
+ #define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
+ #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
+ #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]
+ 
+ /* Individual items aside from the registers.  */
+ #define NUM_NONREG_ITEMS 3
+ 
+ /* Used to examine the stack (to detect infinite loops).  */
+ #define FAILURE_PAT(h) fail_stack.stack[(h) - 1].pointer
+ #define FAILURE_STR(h) (fail_stack.stack[(h) - 2].pointer)
+ #define NEXT_FAILURE_HANDLE(h) fail_stack.stack[(h) - 3].integer
+ #define TOP_FAILURE_HANDLE() fail_stack.frame
+ 
+ 
+ #define ENSURE_FAIL_STACK(space)                                      \
+ while (REMAINING_AVAIL_SLOTS <= space) {                              \
+   if (!GROW_FAIL_STACK (fail_stack))                                  \
+     return -2;                                                                
\
+   DEBUG_PRINT2 ("\n  Doubled stack; size now: %d\n", (fail_stack).size);\
+   DEBUG_PRINT2 ("      slots available: %d\n", REMAINING_AVAIL_SLOTS);\
+ }
+ 
+ /* Push register NUM onto the stack.  */
+ #define PUSH_FAILURE_REG(num)                                         \
+ do {                                                                  \
+   char *destination;                                                  \
+   ENSURE_FAIL_STACK(3);                                                       
\
+   DEBUG_PRINT4 ("    Push reg %d (spanning %p -> %p)\n",              \
+               num, regstart[num], regend[num]);                       \
+   PUSH_FAILURE_POINTER (regstart[num]);                                       
\
+   PUSH_FAILURE_POINTER (regend[num]);                                 \
+   PUSH_FAILURE_INT (num);                                             \
+ } while (0)
+ 
+ /* Change the counter's value to VAL, but make sure that it will
+    be reset when backtracking.  */
+ #define PUSH_NUMBER(ptr,val)                                          \
+ do {                                                                  \
+   char *destination;                                                  \
+   int c;                                                              \
+   ENSURE_FAIL_STACK(3);                                                       
\
+   EXTRACT_NUMBER (c, ptr);                                            \
+   DEBUG_PRINT4 ("    Push number %p = %d -> %d\n", ptr, c, val);      \
+   PUSH_FAILURE_INT (c);                                                       
\
+   PUSH_FAILURE_POINTER (ptr);                                         \
+   PUSH_FAILURE_INT (-1);                                              \
+   STORE_NUMBER (ptr, val);                                            \
+ } while (0)
+ 
+ /* Pop a saved register off the stack.  */
+ #define POP_FAILURE_REG_OR_COUNT()                                    \
+ do {                                                                  \
+   int reg = POP_FAILURE_INT ();                                               
\
+   if (reg == -1)                                                      \
+     {                                                                 \
+       /* It's a counter.  */                                          \
+       /* Here, we discard `const', making re_match non-reentrant.  */ \
+       unsigned char *ptr = (unsigned char*) POP_FAILURE_POINTER ();   \
+       reg = POP_FAILURE_INT ();                                               
\
+       STORE_NUMBER (ptr, reg);                                                
\
+       DEBUG_PRINT3 ("     Pop counter %p = %d\n", ptr, reg);          \
+     }                                                                 \
+   else                                                                        
\
+     {                                                                 \
+       regend[reg] = POP_FAILURE_POINTER ();                           \
+       regstart[reg] = POP_FAILURE_POINTER ();                         \
+       DEBUG_PRINT4 ("     Pop reg %d (spanning %p -> %p)\n",          \
+                   reg, regstart[reg], regend[reg]);                   \
+     }                                                                 \
+ } while (0)
+ 
+ /* Check that we are not stuck in an infinite loop.  */
+ #define CHECK_INFINITE_LOOP(pat_cur, string_place)                    \
+ do {                                                                  \
+   int failure = TOP_FAILURE_HANDLE ();                                        
\
+   /* Check for infinite matching loops */                             \
+   while (failure > 0                                                  \
+        && (FAILURE_STR (failure) == string_place                      \
+            || FAILURE_STR (failure) == NULL))                         \
+     {                                                                 \
+       assert (FAILURE_PAT (failure) >= bufp->buffer                   \
+             && FAILURE_PAT (failure) <= bufp->buffer + bufp->used);   \
+       if (FAILURE_PAT (failure) == pat_cur)                           \
+       {                                                               \
+         cycle = 1;                                                    \
+         break;                                                        \
+       }                                                               \
+       DEBUG_PRINT2 ("  Other pattern: %p\n", FAILURE_PAT (failure));  \
+       failure = NEXT_FAILURE_HANDLE(failure);                         \
+     }                                                                 \
+   DEBUG_PRINT2 ("  Other string: %p\n", FAILURE_STR (failure));               
\
+ } while (0)
+ 
+ /* Push the information about the state we will need
+    if we ever fail back to it.
+ 
+    Requires variables fail_stack, regstart, regend and
+    num_regs be declared.  GROW_FAIL_STACK requires `destination' be
+    declared.
+ 
+    Does `return FAILURE_CODE' if runs out of memory.  */
+ 
+ #define PUSH_FAILURE_POINT(pattern, string_place)                     \
+ do {                                                                  \
+   char *destination;                                                  \
+   /* Must be int, so when we don't save any registers, the arithmetic \
+      of 0 + -1 isn't done as unsigned.  */                            \
+                                                                       \
+   DEBUG_STATEMENT (nfailure_points_pushed++);                         \
+   DEBUG_PRINT1 ("\nPUSH_FAILURE_POINT:\n");                           \
+   DEBUG_PRINT2 ("  Before push, next avail: %d\n", (fail_stack).avail);       
\
+   DEBUG_PRINT2 ("                     size: %d\n", (fail_stack).size);\
+                                                                       \
+   ENSURE_FAIL_STACK (NUM_NONREG_ITEMS);                                       
\
+                                                                       \
+   DEBUG_PRINT1 ("\n");                                                        
\
+                                                                       \
+   DEBUG_PRINT2 ("  Push frame index: %d\n", fail_stack.frame);                
\
+   PUSH_FAILURE_INT (fail_stack.frame);                                        
\
+                                                                       \
+   DEBUG_PRINT2 ("  Push string %p: `", string_place);                 \
+   DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, size2);\
+   DEBUG_PRINT1 ("'\n");                                                       
\
+   PUSH_FAILURE_POINTER (string_place);                                        
\
+                                                                       \
+   DEBUG_PRINT2 ("  Push pattern %p: ", pattern);                      \
+   DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern, pend);                 \
+   PUSH_FAILURE_POINTER (pattern);                                     \
+                                                                       \
+   /* Close the frame by moving the frame pointer past it.  */         \
+   fail_stack.frame = fail_stack.avail;                                        
\
+ } while (0)
+ 
+ /* Estimate the size of data pushed by a typical failure stack entry.
+    An estimate is all we need, because all we use this for
+    is to choose a limit for how big to make the failure stack.  */
+ /* BEWARE, the value `20' is hard-coded in emacs.c:main().  */
+ #define TYPICAL_FAILURE_SIZE 20
+ 
+ /* How many items can still be added to the stack without overflowing it.  */
+ #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
+ 
+ 
+ /* Pops what PUSH_FAIL_STACK pushes.
+ 
+    We restore into the parameters, all of which should be lvalues:
+      STR -- the saved data position.
+      PAT -- the saved pattern position.
+      REGSTART, REGEND -- arrays of string positions.
+ 
+    Also assumes the variables `fail_stack' and (if debugging), `bufp',
+    `pend', `string1', `size1', `string2', and `size2'.        */
+ 
+ #define POP_FAILURE_POINT(str, pat)                                     \
+ do {                                                                  \
+   assert (!FAIL_STACK_EMPTY ());                                      \
+                                                                       \
+   /* Remove failure points and point to how many regs pushed.  */     \
+   DEBUG_PRINT1 ("POP_FAILURE_POINT:\n");                              \
+   DEBUG_PRINT2 ("  Before pop, next avail: %d\n", fail_stack.avail);  \
+   DEBUG_PRINT2 ("                  size: %d\n", fail_stack.size);     \
+                                                                       \
+   /* Pop the saved registers.  */                                     \
+   while (fail_stack.frame < fail_stack.avail)                         \
+     POP_FAILURE_REG_OR_COUNT ();                                      \
+                                                                       \
+   pat = POP_FAILURE_POINTER ();                               \
+   DEBUG_PRINT2 ("  Popping pattern %p: ", pat);                               
\
+   DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend);                     \
+                                                                       \
+   /* If the saved string location is NULL, it came from an            \
+      on_failure_keep_string_jump opcode, and we want to throw away the        
\
+      saved NULL, thus retaining our current position in the string.  */       
\
+   str = POP_FAILURE_POINTER ();                                               
\
+   DEBUG_PRINT2 ("  Popping string %p: `", str);                               
\
+   DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2);    \
+   DEBUG_PRINT1 ("'\n");                                                       
\
+                                                                       \
+   fail_stack.frame = POP_FAILURE_INT ();                              \
+   DEBUG_PRINT2 ("  Popping  frame index: %d\n", fail_stack.frame);    \
+                                                                       \
+   assert (fail_stack.avail >= 0);                                     \
+   assert (fail_stack.frame <= fail_stack.avail);                      \
+                                                                       \
+   DEBUG_STATEMENT (nfailure_points_popped++);                         \
+ } while (0) /* POP_FAILURE_POINT */
+ 
+ 
+ 
+ /* Registers are set to a sentinel when they haven't yet matched.  */
+ #define REG_UNSET(e) ((e) == NULL)
+ 
+ /* Subroutine declarations and macros for regex_compile.  */
+ 
+ static reg_errcode_t regex_compile _RE_ARGS ((re_char *pattern, size_t size,
+                                             reg_syntax_t syntax,
+                                             struct re_pattern_buffer *bufp));
+ static void store_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int 
arg));
+ static void store_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
+                                int arg1, int arg2));
+ static void insert_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
+                                 int arg, unsigned char *end));
+ static void insert_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
+                                 int arg1, int arg2, unsigned char *end));
+ static boolean at_begline_loc_p _RE_ARGS ((re_char *pattern,
+                                          re_char *p,
+                                          reg_syntax_t syntax));
+ static boolean at_endline_loc_p _RE_ARGS ((re_char *p,
+                                          re_char *pend,
+                                          reg_syntax_t syntax));
+ static re_char *skip_one_char _RE_ARGS ((re_char *p));
+ static int analyse_first _RE_ARGS ((re_char *p, re_char *pend,
+                                   char *fastmap, const int multibyte));
+ 
+ /* Fetch the next character in the uncompiled pattern, with no
+    translation.  */
+ #define PATFETCH(c)                                                   \
+   do {                                                                        
\
+     int len;                                                          \
+     if (p == pend) return REG_EEND;                                   \
+     c = RE_STRING_CHAR_AND_LENGTH (p, pend - p, len);                 \
+     p += len;                                                         \
+   } while (0)
+ 
+ 
+ /* If `translate' is non-null, return translate[D], else just D.  We
+    cast the subscript to translate because some data is declared as
+    `char *', to avoid warnings when a string constant is passed.  But
+    when we use a character as a subscript we must make it unsigned.  */
+ #ifndef TRANSLATE
+ # define TRANSLATE(d) \
+   (RE_TRANSLATE_P (translate) ? RE_TRANSLATE (translate, (d)) : (d))
+ #endif
+ 
+ 
+ /* Macros for outputting the compiled pattern into `buffer'.  */
+ 
+ /* If the buffer isn't allocated when it comes in, use this.  */
+ #define INIT_BUF_SIZE  32
+ 
+ /* Make sure we have at least N more bytes of space in buffer.  */
+ #define GET_BUFFER_SPACE(n)                                           \
+     while ((size_t) (b - bufp->buffer + (n)) > bufp->allocated)               
\
+       EXTEND_BUFFER ()
+ 
+ /* Make sure we have one more byte of buffer space and then add C to it.  */
+ #define BUF_PUSH(c)                                                   \
+   do {                                                                        
\
+     GET_BUFFER_SPACE (1);                                             \
+     *b++ = (unsigned char) (c);                                               
\
+   } while (0)
+ 
+ 
+ /* Ensure we have two more bytes of buffer space and then append C1 and C2.  
*/
+ #define BUF_PUSH_2(c1, c2)                                            \
+   do {                                                                        
\
+     GET_BUFFER_SPACE (2);                                             \
+     *b++ = (unsigned char) (c1);                                      \
+     *b++ = (unsigned char) (c2);                                      \
+   } while (0)
+ 
+ 
+ /* As with BUF_PUSH_2, except for three bytes.  */
+ #define BUF_PUSH_3(c1, c2, c3)                                                
\
+   do {                                                                        
\
+     GET_BUFFER_SPACE (3);                                             \
+     *b++ = (unsigned char) (c1);                                      \
+     *b++ = (unsigned char) (c2);                                      \
+     *b++ = (unsigned char) (c3);                                      \
+   } while (0)
+ 
+ 
+ /* Store a jump with opcode OP at LOC to location TO.  We store a
+    relative address offset by the three bytes the jump itself occupies.  */
+ #define STORE_JUMP(op, loc, to) \
+   store_op1 (op, loc, (to) - (loc) - 3)
+ 
+ /* Likewise, for a two-argument jump.  */
+ #define STORE_JUMP2(op, loc, to, arg) \
+   store_op2 (op, loc, (to) - (loc) - 3, arg)
+ 
+ /* Like `STORE_JUMP', but for inserting.  Assume `b' is the buffer end.  */
+ #define INSERT_JUMP(op, loc, to) \
+   insert_op1 (op, loc, (to) - (loc) - 3, b)
+ 
+ /* Like `STORE_JUMP2', but for inserting.  Assume `b' is the buffer end.  */
+ #define INSERT_JUMP2(op, loc, to, arg) \
+   insert_op2 (op, loc, (to) - (loc) - 3, arg, b)
+ 
+ 
+ /* This is not an arbitrary limit: the arguments which represent offsets
+    into the pattern are two bytes long.  So if 2^16 bytes turns out to
+    be too small, many things would have to change.  */
+ /* Any other compiler which, like MSC, has allocation limit below 2^16
+    bytes will have to use approach similar to what was done below for
+    MSC and drop MAX_BUF_SIZE a bit.  Otherwise you may end up
+    reallocating to 0 bytes.  Such thing is not going to work too well.
+    You have been warned!!  */
+ #if defined _MSC_VER  && !defined WIN32
+ /* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.  */
+ # define MAX_BUF_SIZE  65500L
+ #else
+ # define MAX_BUF_SIZE (1L << 16)
+ #endif
+ 
+ /* Extend the buffer by twice its current size via realloc and
+    reset the pointers that pointed into the old block to point to the
+    correct places in the new one.  If extending the buffer results in it
+    being larger than MAX_BUF_SIZE, then flag memory exhausted.  */
+ #if __BOUNDED_POINTERS__
+ # define SET_HIGH_BOUND(P) (__ptrhigh (P) = __ptrlow (P) + bufp->allocated)
+ # define MOVE_BUFFER_POINTER(P) \
+   (__ptrlow (P) += incr, SET_HIGH_BOUND (P), __ptrvalue (P) += incr)
+ # define ELSE_EXTEND_BUFFER_HIGH_BOUND                \
+   else                                                \
+     {                                         \
+       SET_HIGH_BOUND (b);                     \
+       SET_HIGH_BOUND (begalt);                        \
+       if (fixup_alt_jump)                     \
+       SET_HIGH_BOUND (fixup_alt_jump);        \
+       if (laststart)                          \
+       SET_HIGH_BOUND (laststart);             \
+       if (pending_exact)                      \
+       SET_HIGH_BOUND (pending_exact);         \
+     }
+ #else
+ # define MOVE_BUFFER_POINTER(P) (P) += incr
+ # define ELSE_EXTEND_BUFFER_HIGH_BOUND
+ #endif
+ #define EXTEND_BUFFER()                                                       
\
+   do {                                                                        
\
+     re_char *old_buffer = bufp->buffer;                                       
\
+     if (bufp->allocated == MAX_BUF_SIZE)                              \
+       return REG_ESIZE;                                                       
\
+     bufp->allocated <<= 1;                                            \
+     if (bufp->allocated > MAX_BUF_SIZE)                                       
\
+       bufp->allocated = MAX_BUF_SIZE;                                 \
+     RETALLOC (bufp->buffer, bufp->allocated, unsigned char);          \
+     if (bufp->buffer == NULL)                                         \
+       return REG_ESPACE;                                              \
+     /* If the buffer moved, move all the pointers into it.  */                
\
+     if (old_buffer != bufp->buffer)                                   \
+       {                                                                       
\
+       int incr = bufp->buffer - old_buffer;                           \
+       MOVE_BUFFER_POINTER (b);                                        \
+       MOVE_BUFFER_POINTER (begalt);                                   \
+       if (fixup_alt_jump)                                             \
+         MOVE_BUFFER_POINTER (fixup_alt_jump);                         \
+       if (laststart)                                                  \
+         MOVE_BUFFER_POINTER (laststart);                              \
+       if (pending_exact)                                              \
+         MOVE_BUFFER_POINTER (pending_exact);                          \
+       }                                                                       
\
+     ELSE_EXTEND_BUFFER_HIGH_BOUND                                     \
+   } while (0)
+ 
+ 
+ /* Since we have one byte reserved for the register number argument to
+    {start,stop}_memory, the maximum number of groups we can report
+    things about is what fits in that byte.  */
+ #define MAX_REGNUM 255
+ 
+ /* But patterns can have more than `MAX_REGNUM' registers.  We just
+    ignore the excess.  */
+ typedef int regnum_t;
+ 
+ 
+ /* Macros for the compile stack.  */
+ 
+ /* Since offsets can go either forwards or backwards, this type needs to
+    be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1.  */
+ /* int may be not enough when sizeof(int) == 2.  */
+ typedef long pattern_offset_t;
+ 
+ typedef struct
+ {
+   pattern_offset_t begalt_offset;
+   pattern_offset_t fixup_alt_jump;
+   pattern_offset_t laststart_offset;
+   regnum_t regnum;
+ } compile_stack_elt_t;
+ 
+ 
+ typedef struct
+ {
+   compile_stack_elt_t *stack;
+   unsigned size;
+   unsigned avail;                     /* Offset of next open position.  */
+ } compile_stack_type;
+ 
+ 
+ #define INIT_COMPILE_STACK_SIZE 32
+ 
+ #define COMPILE_STACK_EMPTY  (compile_stack.avail == 0)
+ #define COMPILE_STACK_FULL  (compile_stack.avail == compile_stack.size)
+ 
+ /* The next available element.  */
+ #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
+ 
+ /* Explicit quit checking is only used on NTemacs.  */
+ #if defined WINDOWSNT && defined emacs && defined QUIT
+ extern int immediate_quit;
+ # define IMMEDIATE_QUIT_CHECK                 \
+     do {                                      \
+       if (immediate_quit) QUIT;                       \
+     } while (0)
+ #else
+ # define IMMEDIATE_QUIT_CHECK    ((void)0)
+ #endif
+ 
+ /* Structure to manage work area for range table.  */
+ struct range_table_work_area
+ {
+   int *table;                 /* actual work area.  */
+   int allocated;              /* allocated size for work area in bytes.  */
+   int used;                   /* actually used size in words.  */
+   int bits;                   /* flag to record character classes */
+ };
+ 
+ /* Make sure that WORK_AREA can hold more N multibyte characters.
+    This is used only in set_image_of_range and set_image_of_range_1.
+    It expects WORK_AREA to be a pointer.
+    If it can't get the space, it returns from the surrounding function.  */
+ 
+ #define EXTEND_RANGE_TABLE(work_area, n)                              \
+   do {                                                                        
\
+     if (((work_area).used + (n)) * sizeof (int) > (work_area).allocated) \
+       {                                                                       
\
+         extend_range_table_work_area (&work_area);                    \
+         if ((work_area).table == 0)                                   \
+           return (REG_ESPACE);                                                
\
+       }                                                                       
\
+   } while (0)
+ 
+ #define SET_RANGE_TABLE_WORK_AREA_BIT(work_area, bit)         \
+   (work_area).bits |= (bit)
+ 
+ /* Bits used to implement the multibyte-part of the various character classes
+    such as [:alnum:] in a charset's range table.  */
+ #define BIT_WORD      0x1
+ #define BIT_LOWER     0x2
+ #define BIT_PUNCT     0x4
+ #define BIT_SPACE     0x8
+ #define BIT_UPPER     0x10
+ #define BIT_MULTIBYTE 0x20
+ 
+ /* Set a range (RANGE_START, RANGE_END) to WORK_AREA.  */
+ #define SET_RANGE_TABLE_WORK_AREA(work_area, range_start, range_end)  \
+   do {                                                                        
\
+     EXTEND_RANGE_TABLE ((work_area), 2);                              \
+     (work_area).table[(work_area).used++] = (range_start);            \
+     (work_area).table[(work_area).used++] = (range_end);              \
+   } while (0)
+ 
+ /* Free allocated memory for WORK_AREA.        */
+ #define FREE_RANGE_TABLE_WORK_AREA(work_area) \
+   do {                                                \
+     if ((work_area).table)                    \
+       free ((work_area).table);                       \
+   } while (0)
+ 
+ #define CLEAR_RANGE_TABLE_WORK_USED(work_area) ((work_area).used = 0, 
(work_area).bits = 0)
+ #define RANGE_TABLE_WORK_USED(work_area) ((work_area).used)
+ #define RANGE_TABLE_WORK_BITS(work_area) ((work_area).bits)
+ #define RANGE_TABLE_WORK_ELT(work_area, i) ((work_area).table[i])
+ 
+ 
+ /* Set the bit for character C in a list.  */
+ #define SET_LIST_BIT(c) (b[((c)) / BYTEWIDTH] |= 1 << ((c) % BYTEWIDTH))
+ 
+ 
+ #ifdef emacs
+ 
+ /* Store characters in the rage range C0 to C1 in WORK_AREA while
+    translating them and paying attention to the continuity of
+    translated characters.
+ 
+    Implementation note: It is better to implement this fairly big
+    macro by a function, but it's not that easy because macros called
+    in this macro assume various local variables already declared.  */
+ 
+ #define SETUP_MULTIBYTE_RANGE(work_area, c0, c1)                            \
+   do {                                                                        
      \
+     re_wchar_t c, t, t_last;                                                \
+     int n;                                                                  \
+                                                                             \
+     c = (c0);                                                               \
+     t_last = multibyte ? TRANSLATE (c) : TRANSLATE (MAKE_CHAR_MULTIBYTE (c)); 
\
+     for (c++, n = 1; c <= (c1); c++, n++)                                   \
+       {                                                                       
      \
+       t = multibyte ? TRANSLATE (c) : TRANSLATE (MAKE_CHAR_MULTIBYTE (c));  \
+       if (t_last + n == t)                                                  \
+         continue;                                                           \
+       SET_RANGE_TABLE_WORK_AREA ((work_area), t_last, t_last + n - 1);      \
+       t_last = t;                                                           \
+       n = 0;                                                                \
+       }                                                                       
      \
+     if (n > 0)                                                                
      \
+       SET_RANGE_TABLE_WORK_AREA ((work_area), t_last, t_last + n - 1);        
      \
+   } while (0)
+ 
+ #endif /* emacs */
+ 
+ /* Get the next unsigned number in the uncompiled pattern.  */
+ #define GET_UNSIGNED_NUMBER(num)                                      \
+  do { if (p != pend)                                                  \
+      {                                                                        
\
+        PATFETCH (c);                                                  \
+        if (c == ' ')                                                  \
+        FREE_STACK_RETURN (REG_BADBR);                                 \
+        while ('0' <= c && c <= '9')                                   \
+        {                                                              \
+            int prev;                                                  \
+          if (num < 0)                                                 \
+            num = 0;                                                   \
+          prev = num;                                                  \
+          num = num * 10 + c - '0';                                    \
+          if (num / 10 != prev)                                        \
+            FREE_STACK_RETURN (REG_BADBR);                             \
+          if (p == pend)                                               \
+            break;                                                     \
+          PATFETCH (c);                                                \
+        }                                                              \
+        if (c == ' ')                                                  \
+        FREE_STACK_RETURN (REG_BADBR);                                 \
+        }                                                              \
+     } while (0)
+ 
+ #if WIDE_CHAR_SUPPORT
+ /* The GNU C library provides support for user-defined character classes
+    and the functions from ISO C amendement 1.  */
+ # ifdef CHARCLASS_NAME_MAX
+ #  define CHAR_CLASS_MAX_LENGTH CHARCLASS_NAME_MAX
+ # else
+ /* This shouldn't happen but some implementation might still have this
+    problem.  Use a reasonable default value.  */
+ #  define CHAR_CLASS_MAX_LENGTH 256
+ # endif
+ typedef wctype_t re_wctype_t;
+ typedef wchar_t re_wchar_t;
+ # define re_wctype wctype
+ # define re_iswctype iswctype
+ # define re_wctype_to_bit(cc) 0
+ #else
+ # define CHAR_CLASS_MAX_LENGTH  9 /* Namely, `multibyte'.  */
+ # define btowc(c) c
+ 
+ /* Character classes.  */
+ typedef enum { RECC_ERROR = 0,
+              RECC_ALNUM, RECC_ALPHA, RECC_WORD,
+              RECC_GRAPH, RECC_PRINT,
+              RECC_LOWER, RECC_UPPER,
+              RECC_PUNCT, RECC_CNTRL,
+              RECC_DIGIT, RECC_XDIGIT,
+              RECC_BLANK, RECC_SPACE,
+              RECC_MULTIBYTE, RECC_NONASCII,
+              RECC_ASCII, RECC_UNIBYTE
+ } re_wctype_t;
+ 
+ typedef int re_wchar_t;
+ 
+ /* Map a string to the char class it names (if any).  */
+ static re_wctype_t
+ re_wctype (str)
+      re_char *str;
+ {
+   const char *string = str;
+   if      (STREQ (string, "alnum"))   return RECC_ALNUM;
+   else if (STREQ (string, "alpha"))   return RECC_ALPHA;
+   else if (STREQ (string, "word"))    return RECC_WORD;
+   else if (STREQ (string, "ascii"))   return RECC_ASCII;
+   else if (STREQ (string, "nonascii"))        return RECC_NONASCII;
+   else if (STREQ (string, "graph"))   return RECC_GRAPH;
+   else if (STREQ (string, "lower"))   return RECC_LOWER;
+   else if (STREQ (string, "print"))   return RECC_PRINT;
+   else if (STREQ (string, "punct"))   return RECC_PUNCT;
+   else if (STREQ (string, "space"))   return RECC_SPACE;
+   else if (STREQ (string, "upper"))   return RECC_UPPER;
+   else if (STREQ (string, "unibyte")) return RECC_UNIBYTE;
+   else if (STREQ (string, "multibyte"))       return RECC_MULTIBYTE;
+   else if (STREQ (string, "digit"))   return RECC_DIGIT;
+   else if (STREQ (string, "xdigit"))  return RECC_XDIGIT;
+   else if (STREQ (string, "cntrl"))   return RECC_CNTRL;
+   else if (STREQ (string, "blank"))   return RECC_BLANK;
+   else return 0;
+ }
+ 
+ /* True iff CH is in the char class CC.  */
+ static boolean
+ re_iswctype (ch, cc)
+      int ch;
+      re_wctype_t cc;
+ {
+   switch (cc)
+     {
+     case RECC_ALNUM: return ISALNUM (ch);
+     case RECC_ALPHA: return ISALPHA (ch);
+     case RECC_BLANK: return ISBLANK (ch);
+     case RECC_CNTRL: return ISCNTRL (ch);
+     case RECC_DIGIT: return ISDIGIT (ch);
+     case RECC_GRAPH: return ISGRAPH (ch);
+     case RECC_LOWER: return ISLOWER (ch);
+     case RECC_PRINT: return ISPRINT (ch);
+     case RECC_PUNCT: return ISPUNCT (ch);
+     case RECC_SPACE: return ISSPACE (ch);
+     case RECC_UPPER: return ISUPPER (ch);
+     case RECC_XDIGIT: return ISXDIGIT (ch);
+     case RECC_ASCII: return IS_REAL_ASCII (ch);
+     case RECC_NONASCII: return !IS_REAL_ASCII (ch);
+     case RECC_UNIBYTE: return ISUNIBYTE (ch);
+     case RECC_MULTIBYTE: return !ISUNIBYTE (ch);
+     case RECC_WORD: return ISWORD (ch);
+     case RECC_ERROR: return false;
+     default:
+       abort();
+     }
+ }
+ 
+ /* Return a bit-pattern to use in the range-table bits to match multibyte
+    chars of class CC.  */
+ static int
+ re_wctype_to_bit (cc)
+      re_wctype_t cc;
+ {
+   switch (cc)
+     {
+     case RECC_NONASCII: case RECC_PRINT: case RECC_GRAPH:
+     case RECC_MULTIBYTE: return BIT_MULTIBYTE;
+     case RECC_ALPHA: case RECC_ALNUM: case RECC_WORD: return BIT_WORD;
+     case RECC_LOWER: return BIT_LOWER;
+     case RECC_UPPER: return BIT_UPPER;
+     case RECC_PUNCT: return BIT_PUNCT;
+     case RECC_SPACE: return BIT_SPACE;
+     case RECC_ASCII: case RECC_DIGIT: case RECC_XDIGIT: case RECC_CNTRL:
+     case RECC_BLANK: case RECC_UNIBYTE: case RECC_ERROR: return 0;
+     default:
+       abort();
+     }
+ }
+ #endif
+ 
+ /* Filling in the work area of a range.  */
+ 
+ /* Actually extend the space in WORK_AREA.  */
+ 
+ static void
+ extend_range_table_work_area (work_area)
+      struct range_table_work_area *work_area;
+ {
+   work_area->allocated += 16 * sizeof (int);
+   if (work_area->table)
+     work_area->table
+       = (int *) realloc (work_area->table, work_area->allocated);
+   else
+     work_area->table
+       = (int *) malloc (work_area->allocated);
+ }
+ 
+ #if 0
+ #ifdef emacs
+ 
+ /* Carefully find the ranges of codes that are equivalent
+    under case conversion to the range start..end when passed through
+    TRANSLATE.  Handle the case where non-letters can come in between
+    two upper-case letters (which happens in Latin-1).
+    Also handle the case of groups of more than 2 case-equivalent chars.
+ 
+    The basic method is to look at consecutive characters and see
+    if they can form a run that can be handled as one.
+ 
+    Returns -1 if successful, REG_ESPACE if ran out of space.  */
+ 
+ static int
+ set_image_of_range_1 (work_area, start, end, translate)
+      RE_TRANSLATE_TYPE translate;
+      struct range_table_work_area *work_area;
+      re_wchar_t start, end;
+ {
+   /* `one_case' indicates a character, or a run of characters,
+      each of which is an isolate (no case-equivalents).
+      This includes all ASCII non-letters.
+ 
+      `two_case' indicates a character, or a run of characters,
+      each of which has two case-equivalent forms.
+      This includes all ASCII letters.
+ 
+      `strange' indicates a character that has more than one
+      case-equivalent.  */
+ 
+   enum case_type {one_case, two_case, strange};
+ 
+   /* Describe the run that is in progress,
+      which the next character can try to extend.
+      If run_type is strange, that means there really is no run.
+      If run_type is one_case, then run_start...run_end is the run.
+      If run_type is two_case, then the run is run_start...run_end,
+      and the case-equivalents end at run_eqv_end.  */
+ 
+   enum case_type run_type = strange;
+   int run_start, run_end, run_eqv_end;
+ 
+   Lisp_Object eqv_table;
+ 
+   if (!RE_TRANSLATE_P (translate))
+     {
+       EXTEND_RANGE_TABLE (work_area, 2);
+       work_area->table[work_area->used++] = (start);
+       work_area->table[work_area->used++] = (end);
+       return -1;
+     }
+ 
+   eqv_table = XCHAR_TABLE (translate)->extras[2];
+ 
+   for (; start <= end; start++)
+     {
+       enum case_type this_type;
+       int eqv = RE_TRANSLATE (eqv_table, start);
+       int minchar, maxchar;
+ 
+       /* Classify this character */
+       if (eqv == start)
+       this_type = one_case;
+       else if (RE_TRANSLATE (eqv_table, eqv) == start)
+       this_type = two_case;
+       else
+       this_type = strange;
+ 
+       if (start < eqv)
+       minchar = start, maxchar = eqv;
+       else
+       minchar = eqv, maxchar = start;
+ 
+       /* Can this character extend the run in progress?  */
+       if (this_type == strange || this_type != run_type
+         || !(minchar == run_end + 1
+              && (run_type == two_case
+                  ? maxchar == run_eqv_end + 1 : 1)))
+       {
+         /* No, end the run.
+            Record each of its equivalent ranges.  */
+         if (run_type == one_case)
+           {
+             EXTEND_RANGE_TABLE (work_area, 2);
+             work_area->table[work_area->used++] = run_start;
+             work_area->table[work_area->used++] = run_end;
+           }
+         else if (run_type == two_case)
+           {
+             EXTEND_RANGE_TABLE (work_area, 4);
+             work_area->table[work_area->used++] = run_start;
+             work_area->table[work_area->used++] = run_end;
+             work_area->table[work_area->used++]
+               = RE_TRANSLATE (eqv_table, run_start);
+             work_area->table[work_area->used++]
+               = RE_TRANSLATE (eqv_table, run_end);
+           }
+         run_type = strange;
+       }
+ 
+       if (this_type == strange)
+       {
+         /* For a strange character, add each of its equivalents, one
+            by one.  Don't start a range.  */
+         do
+           {
+             EXTEND_RANGE_TABLE (work_area, 2);
+             work_area->table[work_area->used++] = eqv;
+             work_area->table[work_area->used++] = eqv;
+             eqv = RE_TRANSLATE (eqv_table, eqv);
+           }
+         while (eqv != start);
+       }
+ 
+       /* Add this char to the run, or start a new run.  */
+       else if (run_type == strange)
+       {
+         /* Initialize a new range.  */
+         run_type = this_type;
+         run_start = start;
+         run_end = start;
+         run_eqv_end = RE_TRANSLATE (eqv_table, run_end);
+       }
+       else
+       {
+         /* Extend a running range.  */
+         run_end = minchar;
+         run_eqv_end = RE_TRANSLATE (eqv_table, run_end);
+       }
+     }
+ 
+   /* If a run is still in progress at the end, finish it now
+      by recording its equivalent ranges.  */
+   if (run_type == one_case)
+     {
+       EXTEND_RANGE_TABLE (work_area, 2);
+       work_area->table[work_area->used++] = run_start;
+       work_area->table[work_area->used++] = run_end;
+     }
+   else if (run_type == two_case)
+     {
+       EXTEND_RANGE_TABLE (work_area, 4);
+       work_area->table[work_area->used++] = run_start;
+       work_area->table[work_area->used++] = run_end;
+       work_area->table[work_area->used++]
+       = RE_TRANSLATE (eqv_table, run_start);
+       work_area->table[work_area->used++]
+       = RE_TRANSLATE (eqv_table, run_end);
+     }
+ 
+   return -1;
+ }
+ 
+ #endif /* emacs */
+ 
+ /* Record the the image of the range start..end when passed through
+    TRANSLATE.  This is not necessarily TRANSLATE(start)..TRANSLATE(end)
+    and is not even necessarily contiguous.
+    Normally we approximate it with the smallest contiguous range that contains
+    all the chars we need.  However, for Latin-1 we go to extra effort
+    to do a better job.
+ 
+    This function is not called for ASCII ranges.
+ 
+    Returns -1 if successful, REG_ESPACE if ran out of space.  */
+ 
+ static int
+ set_image_of_range (work_area, start, end, translate)
+      RE_TRANSLATE_TYPE translate;
+      struct range_table_work_area *work_area;
+      re_wchar_t start, end;
+ {
+   re_wchar_t cmin, cmax;
+ 
+ #ifdef emacs
+   /* For Latin-1 ranges, use set_image_of_range_1
+      to get proper handling of ranges that include letters and nonletters.
+      For a range that includes the whole of Latin-1, this is not necessary.
+      For other character sets, we don't bother to get this right.  */
+   if (RE_TRANSLATE_P (translate) && start < 04400
+       && !(start < 04200 && end >= 04377))
+     {
+       int newend;
+       int tem;
+       newend = end;
+       if (newend > 04377)
+       newend = 04377;
+       tem = set_image_of_range_1 (work_area, start, newend, translate);
+       if (tem > 0)
+       return tem;
+ 
+       start = 04400;
+       if (end < 04400)
+       return -1;
+     }
+ #endif
+ 
+   EXTEND_RANGE_TABLE (work_area, 2);
+   work_area->table[work_area->used++] = (start);
+   work_area->table[work_area->used++] = (end);
+ 
+   cmin = -1, cmax = -1;
+ 
+   if (RE_TRANSLATE_P (translate))
+     {
+       int ch;
+ 
+       for (ch = start; ch <= end; ch++)
+       {
+         re_wchar_t c = TRANSLATE (ch);
+         if (! (start <= c && c <= end))
+           {
+             if (cmin == -1)
+               cmin = c, cmax = c;
+             else
+               {
+                 cmin = MIN (cmin, c);
+                 cmax = MAX (cmax, c);
+               }
+           }
+       }
+ 
+       if (cmin != -1)
+       {
+         EXTEND_RANGE_TABLE (work_area, 2);
+         work_area->table[work_area->used++] = (cmin);
+         work_area->table[work_area->used++] = (cmax);
+       }
+     }
+ 
+   return -1;
+ }
+ #endif        /* 0 */
+ 
+ #ifndef MATCH_MAY_ALLOCATE
+ 
+ /* If we cannot allocate large objects within re_match_2_internal,
+    we make the fail stack and register vectors global.
+    The fail stack, we grow to the maximum size when a regexp
+    is compiled.
+    The register vectors, we adjust in size each time we
+    compile a regexp, according to the number of registers it needs.  */
+ 
+ static fail_stack_type fail_stack;
+ 
+ /* Size with which the following vectors are currently allocated.
+    That is so we can make them bigger as needed,
+    but never make them smaller.  */
+ static int regs_allocated_size;
+ 
+ static re_char **     regstart, **     regend;
+ static re_char **best_regstart, **best_regend;
+ 
+ /* Make the register vectors big enough for NUM_REGS registers,
+    but don't make them smaller.  */
+ 
+ static
+ regex_grow_registers (num_regs)
+      int num_regs;
+ {
+   if (num_regs > regs_allocated_size)
+     {
+       RETALLOC_IF (regstart,   num_regs, re_char *);
+       RETALLOC_IF (regend,     num_regs, re_char *);
+       RETALLOC_IF (best_regstart, num_regs, re_char *);
+       RETALLOC_IF (best_regend,        num_regs, re_char *);
+ 
+       regs_allocated_size = num_regs;
+     }
+ }
+ 
+ #endif /* not MATCH_MAY_ALLOCATE */
+ 
+ static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
+                                                compile_stack,
+                                                regnum_t regnum));
+ 
+ /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
+    Returns one of error codes defined in `regex.h', or zero for success.
+ 
+    Assumes the `allocated' (and perhaps `buffer') and `translate'
+    fields are set in BUFP on entry.
+ 
+    If it succeeds, results are put in BUFP (if it returns an error, the
+    contents of BUFP are undefined):
+      `buffer' is the compiled pattern;
+      `syntax' is set to SYNTAX;
+      `used' is set to the length of the compiled pattern;
+      `fastmap_accurate' is zero;
+      `re_nsub' is the number of subexpressions in PATTERN;
+      `not_bol' and `not_eol' are zero;
+ 
+    The `fastmap' field is neither examined nor set.  */
+ 
+ /* Insert the `jump' from the end of last alternative to "here".
+    The space for the jump has already been allocated. */
+ #define FIXUP_ALT_JUMP()                                              \
+ do {                                                                  \
+   if (fixup_alt_jump)                                                 \
+     STORE_JUMP (jump, fixup_alt_jump, b);                             \
+ } while (0)
+ 
+ 
+ /* Return, freeing storage we allocated.  */
+ #define FREE_STACK_RETURN(value)              \
+   do {                                                        \
+     FREE_RANGE_TABLE_WORK_AREA (range_table_work);    \
+     free (compile_stack.stack);                               \
+     return value;                                     \
+   } while (0)
+ 
+ static reg_errcode_t
+ regex_compile (pattern, size, syntax, bufp)
+      re_char *pattern;
+      size_t size;
+      reg_syntax_t syntax;
+      struct re_pattern_buffer *bufp;
+ {
+   /* We fetch characters from PATTERN here.  */
+   register re_wchar_t c, c1;
+ 
+   /* A random temporary spot in PATTERN.  */
+   re_char *p1;
+ 
+   /* Points to the end of the buffer, where we should append.  */
+   register unsigned char *b;
+ 
+   /* Keeps track of unclosed groups.  */
+   compile_stack_type compile_stack;
+ 
+   /* Points to the current (ending) position in the pattern.  */
+ #ifdef AIX
+   /* `const' makes AIX compiler fail.  */
+   unsigned char *p = pattern;
+ #else
+   re_char *p = pattern;
+ #endif
+   re_char *pend = pattern + size;
+ 
+   /* How to translate the characters in the pattern.  */
+   RE_TRANSLATE_TYPE translate = bufp->translate;
+ 
+   /* Address of the count-byte of the most recently inserted `exactn'
+      command.  This makes it possible to tell if a new exact-match
+      character can be added to that command or if the character requires
+      a new `exactn' command.  */
+   unsigned char *pending_exact = 0;
+ 
+   /* Address of start of the most recently finished expression.
+      This tells, e.g., postfix * where to find the start of its
+      operand.  Reset at the beginning of groups and alternatives.  */
+   unsigned char *laststart = 0;
+ 
+   /* Address of beginning of regexp, or inside of last group.  */
+   unsigned char *begalt;
+ 
+   /* Place in the uncompiled pattern (i.e., the {) to
+      which to go back if the interval is invalid.  */
+   re_char *beg_interval;
+ 
+   /* Address of the place where a forward jump should go to the end of
+      the containing expression.        Each alternative of an `or' -- except 
the
+      last -- ends with a forward jump of this sort.  */
+   unsigned char *fixup_alt_jump = 0;
+ 
+   /* Counts open-groups as they are encountered.  Remembered for the
+      matching close-group on the compile stack, so the same register
+      number is put in the stop_memory as the start_memory.  */
+   regnum_t regnum = 0;
+ 
+   /* Work area for range table of charset.  */
+   struct range_table_work_area range_table_work;
+ 
+   /* If the object matched can contain multibyte characters.  */
+   const boolean multibyte = RE_MULTIBYTE_P (bufp);
+ 
+   /* If a target of matching can contain multibyte characters.  */
+   const boolean target_multibyte = RE_TARGET_MULTIBYTE_P (bufp);
+ 
+ #ifdef DEBUG
+   debug++;
+   DEBUG_PRINT1 ("\nCompiling pattern: ");
+   if (debug > 0)
+     {
+       unsigned debug_count;
+ 
+       for (debug_count = 0; debug_count < size; debug_count++)
+       putchar (pattern[debug_count]);
+       putchar ('\n');
+     }
+ #endif /* DEBUG */
+ 
+   /* Initialize the compile stack.  */
+   compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
+   if (compile_stack.stack == NULL)
+     return REG_ESPACE;
+ 
+   compile_stack.size = INIT_COMPILE_STACK_SIZE;
+   compile_stack.avail = 0;
+ 
+   range_table_work.table = 0;
+   range_table_work.allocated = 0;
+ 
+   /* Initialize the pattern buffer.  */
+   bufp->syntax = syntax;
+   bufp->fastmap_accurate = 0;
+   bufp->not_bol = bufp->not_eol = 0;
+ 
+   /* Set `used' to zero, so that if we return an error, the pattern
+      printer (for debugging) will think there's no pattern.  We reset it
+      at the end.  */
+   bufp->used = 0;
+ 
+   /* Always count groups, whether or not bufp->no_sub is set.  */
+   bufp->re_nsub = 0;
+ 
+ #if !defined emacs && !defined SYNTAX_TABLE
+   /* Initialize the syntax table.  */
+    init_syntax_once ();
+ #endif
+ 
+   if (bufp->allocated == 0)
+     {
+       if (bufp->buffer)
+       { /* If zero allocated, but buffer is non-null, try to realloc
+            enough space.  This loses if buffer's address is bogus, but
+            that is the user's responsibility.  */
+         RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
+       }
+       else
+       { /* Caller did not allocate a buffer.  Do it for them.  */
+         bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
+       }
+       if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);
+ 
+       bufp->allocated = INIT_BUF_SIZE;
+     }
+ 
+   begalt = b = bufp->buffer;
+ 
+   /* Loop through the uncompiled pattern until we're at the end.  */
+   while (p != pend)
+     {
+       PATFETCH (c);
+ 
+       switch (c)
+       {
+       case '^':
+         {
+           if (   /* If at start of pattern, it's an operator.  */
+                  p == pattern + 1
+                  /* If context independent, it's an operator.  */
+               || syntax & RE_CONTEXT_INDEP_ANCHORS
+                  /* Otherwise, depends on what's come before.  */
+               || at_begline_loc_p (pattern, p, syntax))
+             BUF_PUSH ((syntax & RE_NO_NEWLINE_ANCHOR) ? begbuf : begline);
+           else
+             goto normal_char;
+         }
+         break;
+ 
+ 
+       case '$':
+         {
+           if (   /* If at end of pattern, it's an operator.  */
+                  p == pend
+                  /* If context independent, it's an operator.  */
+               || syntax & RE_CONTEXT_INDEP_ANCHORS
+                  /* Otherwise, depends on what's next.  */
+               || at_endline_loc_p (p, pend, syntax))
+              BUF_PUSH ((syntax & RE_NO_NEWLINE_ANCHOR) ? endbuf : endline);
+            else
+              goto normal_char;
+          }
+          break;
+ 
+ 
+       case '+':
+       case '?':
+         if ((syntax & RE_BK_PLUS_QM)
+             || (syntax & RE_LIMITED_OPS))
+           goto normal_char;
+       handle_plus:
+       case '*':
+         /* If there is no previous pattern... */
+         if (!laststart)
+           {
+             if (syntax & RE_CONTEXT_INVALID_OPS)
+               FREE_STACK_RETURN (REG_BADRPT);
+             else if (!(syntax & RE_CONTEXT_INDEP_OPS))
+               goto normal_char;
+           }
+ 
+         {
+           /* 1 means zero (many) matches is allowed.  */
+           boolean zero_times_ok = 0, many_times_ok = 0;
+           boolean greedy = 1;
+ 
+           /* If there is a sequence of repetition chars, collapse it
+              down to just one (the right one).  We can't combine
+              interval operators with these because of, e.g., `a{2}*',
+              which should only match an even number of `a's.  */
+ 
+           for (;;)
+             {
+               if ((syntax & RE_FRUGAL)
+                   && c == '?' && (zero_times_ok || many_times_ok))
+                 greedy = 0;
+               else
+                 {
+                   zero_times_ok |= c != '+';
+                   many_times_ok |= c != '?';
+                 }
+ 
+               if (p == pend)
+                 break;
+               else if (*p == '*'
+                        || (!(syntax & RE_BK_PLUS_QM)
+                            && (*p == '+' || *p == '?')))
+                 ;
+               else if (syntax & RE_BK_PLUS_QM  && *p == '\\')
+                 {
+                   if (p+1 == pend)
+                     FREE_STACK_RETURN (REG_EESCAPE);
+                   if (p[1] == '+' || p[1] == '?')
+                     PATFETCH (c); /* Gobble up the backslash.  */
+                   else
+                     break;
+                 }
+               else
+                 break;
+               /* If we get here, we found another repeat character.  */
+               PATFETCH (c);
+              }
+ 
+           /* Star, etc. applied to an empty pattern is equivalent
+              to an empty pattern.  */
+           if (!laststart || laststart == b)
+             break;
+ 
+           /* Now we know whether or not zero matches is allowed
+              and also whether or not two or more matches is allowed.  */
+           if (greedy)
+             {
+               if (many_times_ok)
+                 {
+                   boolean simple = skip_one_char (laststart) == b;
+                   unsigned int startoffset = 0;
+                   re_opcode_t ofj =
+                     /* Check if the loop can match the empty string.  */
+                     (simple || !analyse_first (laststart, b, NULL, 0))
+                     ? on_failure_jump : on_failure_jump_loop;
+                   assert (skip_one_char (laststart) <= b);
+ 
+                   if (!zero_times_ok && simple)
+                     { /* Since simple * loops can be made faster by using
+                          on_failure_keep_string_jump, we turn simple P+
+                          into PP* if P is simple.  */
+                       unsigned char *p1, *p2;
+                       startoffset = b - laststart;
+                       GET_BUFFER_SPACE (startoffset);
+                       p1 = b; p2 = laststart;
+                       while (p2 < p1)
+                         *b++ = *p2++;
+                       zero_times_ok = 1;
+                     }
+ 
+                   GET_BUFFER_SPACE (6);
+                   if (!zero_times_ok)
+                     /* A + loop.  */
+                     STORE_JUMP (ofj, b, b + 6);
+                   else
+                     /* Simple * loops can use on_failure_keep_string_jump
+                        depending on what follows.  But since we don't know
+                        that yet, we leave the decision up to
+                        on_failure_jump_smart.  */
+                     INSERT_JUMP (simple ? on_failure_jump_smart : ofj,
+                                  laststart + startoffset, b + 6);
+                   b += 3;
+                   STORE_JUMP (jump, b, laststart + startoffset);
+                   b += 3;
+                 }
+               else
+                 {
+                   /* A simple ? pattern.  */
+                   assert (zero_times_ok);
+                   GET_BUFFER_SPACE (3);
+                   INSERT_JUMP (on_failure_jump, laststart, b + 3);
+                   b += 3;
+                 }
+             }
+           else                /* not greedy */
+             { /* I wish the greedy and non-greedy cases could be merged. */
+ 
+               GET_BUFFER_SPACE (7); /* We might use less.  */
+               if (many_times_ok)
+                 {
+                   boolean emptyp = analyse_first (laststart, b, NULL, 0);
+ 
+                   /* The non-greedy multiple match looks like
+                      a repeat..until: we only need a conditional jump
+                      at the end of the loop.  */
+                   if (emptyp) BUF_PUSH (no_op);
+                   STORE_JUMP (emptyp ? on_failure_jump_nastyloop
+                               : on_failure_jump, b, laststart);
+                   b += 3;
+                   if (zero_times_ok)
+                     {
+                       /* The repeat...until naturally matches one or more.
+                          To also match zero times, we need to first jump to
+                          the end of the loop (its conditional jump).  */
+                       INSERT_JUMP (jump, laststart, b);
+                       b += 3;
+                     }
+                 }
+               else
+                 {
+                   /* non-greedy a?? */
+                   INSERT_JUMP (jump, laststart, b + 3);
+                   b += 3;
+                   INSERT_JUMP (on_failure_jump, laststart, laststart + 6);
+                   b += 3;
+                 }
+             }
+         }
+         pending_exact = 0;
+         break;
+ 
+ 
+       case '.':
+         laststart = b;
+         BUF_PUSH (anychar);
+         break;
+ 
+ 
+       case '[':
+         {
+           CLEAR_RANGE_TABLE_WORK_USED (range_table_work);
+ 
+           if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+ 
+           /* Ensure that we have enough space to push a charset: the
+              opcode, the length count, and the bitset; 34 bytes in all.  */
+           GET_BUFFER_SPACE (34);
+ 
+           laststart = b;
+ 
+           /* We test `*p == '^' twice, instead of using an if
+              statement, so we only need one BUF_PUSH.  */
+           BUF_PUSH (*p == '^' ? charset_not : charset);
+           if (*p == '^')
+             p++;
+ 
+           /* Remember the first position in the bracket expression.  */
+           p1 = p;
+ 
+           /* Push the number of bytes in the bitmap.  */
+           BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
+ 
+           /* Clear the whole map.  */
+           bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
+ 
+           /* charset_not matches newline according to a syntax bit.  */
+           if ((re_opcode_t) b[-2] == charset_not
+               && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
+             SET_LIST_BIT ('\n');
+ 
+           /* Read in characters and ranges, setting map bits.  */
+           for (;;)
+             {
+               boolean escaped_char = false;
+               const unsigned char *p2 = p;
+ 
+               if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+ 
+               /* Don't translate yet.  The range TRANSLATE(X..Y) cannot
+                  always be determined from TRANSLATE(X) and TRANSLATE(Y)
+                  So the translation is done later in a loop.  Example:
+                  (let ((case-fold-search t)) (string-match "[A-_]" "A"))  */
+               PATFETCH (c);
+ 
+               /* \ might escape characters inside [...] and [^...].  */
+               if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
+                 {
+                   if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+ 
+                   PATFETCH (c);
+                   escaped_char = true;
+                 }
+               else
+                 {
+                   /* Could be the end of the bracket expression.      If it's
+                      not (i.e., when the bracket expression is `[]' so
+                      far), the ']' character bit gets set way below.  */
+                   if (c == ']' && p2 != p1)
+                     break;
+                 }
+ 
+               /* See if we're at the beginning of a possible character
+                  class.  */
+ 
+               if (!escaped_char &&
+                   syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
+                 {
+                   /* Leave room for the null.  */
+                   unsigned char str[CHAR_CLASS_MAX_LENGTH + 1];
+                   const unsigned char *class_beg;
+ 
+                   PATFETCH (c);
+                   c1 = 0;
+                   class_beg = p;
+ 
+                   /* If pattern is `[[:'.  */
+                   if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+ 
+                   for (;;)
+                     {
+                       PATFETCH (c);
+                       if ((c == ':' && *p == ']') || p == pend)
+                         break;
+                       if (c1 < CHAR_CLASS_MAX_LENGTH)
+                         str[c1++] = c;
+                       else
+                         /* This is in any case an invalid class name.  */
+                         str[0] = '\0';
+                     }
+                   str[c1] = '\0';
+ 
+                   /* If isn't a word bracketed by `[:' and `:]':
+                      undo the ending character, the letters, and
+                      leave the leading `:' and `[' (but set bits for
+                      them).  */
+                   if (c == ':' && *p == ']')
+                     {
+                       re_wchar_t ch;
+                       re_wctype_t cc;
+                       int limit;
+ 
+                       cc = re_wctype (str);
+ 
+                       if (cc == 0)
+                         FREE_STACK_RETURN (REG_ECTYPE);
+ 
+                         /* Throw away the ] at the end of the character
+                            class.  */
+                         PATFETCH (c);
+ 
+                         if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+ 
+                       /* Most character classes in a multibyte match
+                          just set a flag.  Exceptions are is_blank,
+                          is_digit, is_cntrl, and is_xdigit, since
+                          they can only match ASCII characters.  We
+                          don't need to handle them for multibyte.
+                          They are distinguished by a negative wctype.  */
+ 
+                       for (ch = 0; ch < 128; ++ch)
+                         if (re_iswctype (btowc (ch), cc))
+                           {
+                             c = TRANSLATE (ch);
+                             SET_LIST_BIT (c);
+                           }
+ 
+                       if (target_multibyte)
+                         {
+                           SET_RANGE_TABLE_WORK_AREA_BIT
+                             (range_table_work, re_wctype_to_bit (cc));
+                         }
+                       else
+                         {
+                           for (ch = 0; ch < (1 << BYTEWIDTH); ++ch)
+                             {
+                               c = ch;
+                               MAKE_CHAR_MULTIBYTE (c);
+                               if (re_iswctype (btowc (c), cc))
+                                 {
+                                   c = TRANSLATE (c);
+                                   MAKE_CHAR_UNIBYTE (c);
+                                   SET_LIST_BIT (c);
+                                 }
+                             }
+                         }
+ 
+                       /* Repeat the loop. */
+                       continue;
+                     }
+                   else
+                     {
+                       /* Go back to right after the "[:".  */
+                       p = class_beg;
+                       SET_LIST_BIT ('[');
+ 
+                       /* Because the `:' may starts the range, we
+                          can't simply set bit and repeat the loop.
+                          Instead, just set it to C and handle below.  */
+                       c = ':';
+                     }
+                 }
+ 
+               if (p < pend && p[0] == '-' && p[1] != ']')
+                 {
+ 
+                   /* Discard the `-'. */
+                   PATFETCH (c1);
+ 
+                   /* Fetch the character which ends the range. */
+                   PATFETCH (c1);
+                   if (c > c1)
+                     {
+                       if (syntax & RE_NO_EMPTY_RANGES)
+                         FREE_STACK_RETURN (REG_ERANGE);
+                       /* Else, repeat the loop.  */
+                     }
+                 }
+               else
+                 /* Range from C to C. */
+                 c1 = c;
+ 
+ #ifndef emacs
+               c = TRANSLATE (c);
+               c1 = TRANSLATE (c1);
+               /* Set the range into bitmap */
+               for (; c <= c1; c++)
+                 SET_LIST_BIT (TRANSLATE (c));
+ #else  /* not emacs */
+               if (target_multibyte)
+                 {
+                   if (c1 >= 128)
+                     {
+                       re_wchar_t c0 = MAX (c, 128);
+ 
+                       SETUP_MULTIBYTE_RANGE (range_table_work, c0, c1);
+                       c1 = 127;
+                     }
+                   for (; c <= c1; c++)
+                     SET_LIST_BIT (TRANSLATE (c));
+                 }
+               else
+                 {
+                   re_wchar_t c0;
+ 
+                   for (; c <= c1; c++)
+                     {
+                       c0 = c;
+                       if (! multibyte)
+                         MAKE_CHAR_MULTIBYTE (c0);
+                       c0 = TRANSLATE (c0);
+                       MAKE_CHAR_UNIBYTE (c0);
+                       SET_LIST_BIT (c0);
+                     }
+                 }
+ #endif /* not emacs */
+             }
+ 
+           /* Discard any (non)matching list bytes that are all 0 at the
+              end of the map.  Decrease the map-length byte too.  */
+           while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
+             b[-1]--;
+           b += b[-1];
+ 
+           /* Build real range table from work area.  */
+           if (RANGE_TABLE_WORK_USED (range_table_work)
+               || RANGE_TABLE_WORK_BITS (range_table_work))
+             {
+               int i;
+               int used = RANGE_TABLE_WORK_USED (range_table_work);
+ 
+               /* Allocate space for COUNT + RANGE_TABLE.  Needs two
+                  bytes for flags, two for COUNT, and three bytes for
+                  each character. */
+               GET_BUFFER_SPACE (4 + used * 3);
+ 
+               /* Indicate the existence of range table.  */
+               laststart[1] |= 0x80;
+ 
+               /* Store the character class flag bits into the range table.
+                  If not in emacs, these flag bits are always 0.  */
+               *b++ = RANGE_TABLE_WORK_BITS (range_table_work) & 0xff;
+               *b++ = RANGE_TABLE_WORK_BITS (range_table_work) >> 8;
+ 
+               STORE_NUMBER_AND_INCR (b, used / 2);
+               for (i = 0; i < used; i++)
+                 STORE_CHARACTER_AND_INCR
+                   (b, RANGE_TABLE_WORK_ELT (range_table_work, i));
+             }
+         }
+         break;
+ 
+ 
+       case '(':
+         if (syntax & RE_NO_BK_PARENS)
+           goto handle_open;
+         else
+           goto normal_char;
+ 
+ 
+       case ')':
+         if (syntax & RE_NO_BK_PARENS)
+           goto handle_close;
+         else
+           goto normal_char;
+ 
+ 
+       case '\n':
+         if (syntax & RE_NEWLINE_ALT)
+           goto handle_alt;
+         else
+           goto normal_char;
+ 
+ 
+       case '|':
+         if (syntax & RE_NO_BK_VBAR)
+           goto handle_alt;
+         else
+           goto normal_char;
+ 
+ 
+       case '{':
+          if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
+            goto handle_interval;
+          else
+            goto normal_char;
+ 
+ 
+       case '\\':
+         if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+ 
+         /* Do not translate the character after the \, so that we can
+            distinguish, e.g., \B from \b, even if we normally would
+            translate, e.g., B to b.  */
+         PATFETCH (c);
+ 
+         switch (c)
+           {
+           case '(':
+             if (syntax & RE_NO_BK_PARENS)
+               goto normal_backslash;
+ 
+           handle_open:
+             {
+               int shy = 0;
+               if (p+1 < pend)
+                 {
+                   /* Look for a special (?...) construct */
+                   if ((syntax & RE_SHY_GROUPS) && *p == '?')
+                     {
+                       PATFETCH (c); /* Gobble up the '?'.  */
+                       PATFETCH (c);
+                       switch (c)
+                         {
+                         case ':': shy = 1; break;
+                         default:
+                           /* Only (?:...) is supported right now. */
+                           FREE_STACK_RETURN (REG_BADPAT);
+                         }
+                     }
+                 }
+ 
+               if (!shy)
+                 {
+                   bufp->re_nsub++;
+                   regnum++;
+                 }
+ 
+               if (COMPILE_STACK_FULL)
+                 {
+                   RETALLOC (compile_stack.stack, compile_stack.size << 1,
+                             compile_stack_elt_t);
+                   if (compile_stack.stack == NULL) return REG_ESPACE;
+ 
+                   compile_stack.size <<= 1;
+                 }
+ 
+               /* These are the values to restore when we hit end of this
+                  group.        They are all relative offsets, so that if the
+                  whole pattern moves because of realloc, they will still
+                  be valid.  */
+               COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
+               COMPILE_STACK_TOP.fixup_alt_jump
+                 = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
+               COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
+               COMPILE_STACK_TOP.regnum = shy ? -regnum : regnum;
+ 
+               /* Do not push a
+                  start_memory for groups beyond the last one we can
+                  represent in the compiled pattern.  */
+               if (regnum <= MAX_REGNUM && !shy)
+                 BUF_PUSH_2 (start_memory, regnum);
+ 
+               compile_stack.avail++;
+ 
+               fixup_alt_jump = 0;
+               laststart = 0;
+               begalt = b;
+               /* If we've reached MAX_REGNUM groups, then this open
+                  won't actually generate any code, so we'll have to
+                  clear pending_exact explicitly.  */
+               pending_exact = 0;
+               break;
+             }
+ 
+           case ')':
+             if (syntax & RE_NO_BK_PARENS) goto normal_backslash;
+ 
+             if (COMPILE_STACK_EMPTY)
+               {
+                 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
+                   goto normal_backslash;
+                 else
+                   FREE_STACK_RETURN (REG_ERPAREN);
+               }
+ 
+           handle_close:
+             FIXUP_ALT_JUMP ();
+ 
+             /* See similar code for backslashed left paren above.  */
+             if (COMPILE_STACK_EMPTY)
+               {
+                 if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
+                   goto normal_char;
+                 else
+                   FREE_STACK_RETURN (REG_ERPAREN);
+               }
+ 
+             /* Since we just checked for an empty stack above, this
+                ``can't happen''.  */
+             assert (compile_stack.avail != 0);
+             {
+               /* We don't just want to restore into `regnum', because
+                  later groups should continue to be numbered higher,
+                  as in `(ab)c(de)' -- the second group is #2.  */
+               regnum_t this_group_regnum;
+ 
+               compile_stack.avail--;
+               begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
+               fixup_alt_jump
+                 = COMPILE_STACK_TOP.fixup_alt_jump
+                   ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
+                   : 0;
+               laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
+               this_group_regnum = COMPILE_STACK_TOP.regnum;
+               /* If we've reached MAX_REGNUM groups, then this open
+                  won't actually generate any code, so we'll have to
+                  clear pending_exact explicitly.  */
+               pending_exact = 0;
+ 
+               /* We're at the end of the group, so now we know how many
+                  groups were inside this one.  */
+               if (this_group_regnum <= MAX_REGNUM && this_group_regnum > 0)
+                 BUF_PUSH_2 (stop_memory, this_group_regnum);
+             }
+             break;
+ 
+ 
+           case '|':                                   /* `\|'.  */
+             if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
+               goto normal_backslash;
+           handle_alt:
+             if (syntax & RE_LIMITED_OPS)
+               goto normal_char;
+ 
+             /* Insert before the previous alternative a jump which
+                jumps to this alternative if the former fails.  */
+             GET_BUFFER_SPACE (3);
+             INSERT_JUMP (on_failure_jump, begalt, b + 6);
+             pending_exact = 0;
+             b += 3;
+ 
+             /* The alternative before this one has a jump after it
+                which gets executed if it gets matched.  Adjust that
+                jump so it will jump to this alternative's analogous
+                jump (put in below, which in turn will jump to the next
+                (if any) alternative's such jump, etc.).  The last such
+                jump jumps to the correct final destination.  A picture:
+                         _____ _____
+                         |   | |   |
+                         |   v |   v
+                        a | b   | c
+ 
+                If we are at `b', then fixup_alt_jump right now points to a
+                three-byte space after `a'.  We'll put in the jump, set
+                fixup_alt_jump to right after `b', and leave behind three
+                bytes which we'll fill in when we get to after `c'.  */
+ 
+             FIXUP_ALT_JUMP ();
+ 
+             /* Mark and leave space for a jump after this alternative,
+                to be filled in later either by next alternative or
+                when know we're at the end of a series of alternatives.  */
+             fixup_alt_jump = b;
+             GET_BUFFER_SPACE (3);
+             b += 3;
+ 
+             laststart = 0;
+             begalt = b;
+             break;
+ 
+ 
+           case '{':
+             /* If \{ is a literal.  */
+             if (!(syntax & RE_INTERVALS)
+                    /* If we're at `\{' and it's not the open-interval
+                       operator.  */
+                 || (syntax & RE_NO_BK_BRACES))
+               goto normal_backslash;
+ 
+           handle_interval:
+             {
+               /* If got here, then the syntax allows intervals.  */
+ 
+               /* At least (most) this many matches must be made.  */
+               int lower_bound = 0, upper_bound = -1;
+ 
+               beg_interval = p;
+ 
+               if (p == pend)
+                 FREE_STACK_RETURN (REG_EBRACE);
+ 
+               GET_UNSIGNED_NUMBER (lower_bound);
+ 
+               if (c == ',')
+                 GET_UNSIGNED_NUMBER (upper_bound);
+               else
+                 /* Interval such as `{1}' => match exactly once. */
+                 upper_bound = lower_bound;
+ 
+               if (lower_bound < 0 || upper_bound > RE_DUP_MAX
+                   || (upper_bound >= 0 && lower_bound > upper_bound))
+                 FREE_STACK_RETURN (REG_BADBR);
+ 
+               if (!(syntax & RE_NO_BK_BRACES))
+                 {
+                   if (c != '\\')
+                     FREE_STACK_RETURN (REG_BADBR);
+ 
+                   PATFETCH (c);
+                 }
+ 
+               if (c != '}')
+                 FREE_STACK_RETURN (REG_BADBR);
+ 
+               /* We just parsed a valid interval.  */
+ 
+               /* If it's invalid to have no preceding re.  */
+               if (!laststart)
+                 {
+                   if (syntax & RE_CONTEXT_INVALID_OPS)
+                     FREE_STACK_RETURN (REG_BADRPT);
+                   else if (syntax & RE_CONTEXT_INDEP_OPS)
+                     laststart = b;
+                   else
+                     goto unfetch_interval;
+                 }
+ 
+               if (upper_bound == 0)
+                 /* If the upper bound is zero, just drop the sub pattern
+                    altogether.  */
+                 b = laststart;
+               else if (lower_bound == 1 && upper_bound == 1)
+                 /* Just match it once: nothing to do here.  */
+                 ;
+ 
+               /* Otherwise, we have a nontrivial interval.  When
+                  we're all done, the pattern will look like:
+                  set_number_at <jump count> <upper bound>
+                  set_number_at <succeed_n count> <lower bound>
+                  succeed_n <after jump addr> <succeed_n count>
+                  <body of loop>
+                  jump_n <succeed_n addr> <jump count>
+                  (The upper bound and `jump_n' are omitted if
+                  `upper_bound' is 1, though.)  */
+               else
+                 { /* If the upper bound is > 1, we need to insert
+                      more at the end of the loop.  */
+                   unsigned int nbytes = (upper_bound < 0 ? 3
+                                          : upper_bound > 1 ? 5 : 0);
+                   unsigned int startoffset = 0;
+ 
+                   GET_BUFFER_SPACE (20); /* We might use less.  */
+ 
+                   if (lower_bound == 0)
+                     {
+                       /* A succeed_n that starts with 0 is really a
+                          a simple on_failure_jump_loop.  */
+                       INSERT_JUMP (on_failure_jump_loop, laststart,
+                                    b + 3 + nbytes);
+                       b += 3;
+                     }
+                   else
+                     {
+                       /* Initialize lower bound of the `succeed_n', even
+                          though it will be set during matching by its
+                          attendant `set_number_at' (inserted next),
+                          because `re_compile_fastmap' needs to know.
+                          Jump to the `jump_n' we might insert below.  */
+                       INSERT_JUMP2 (succeed_n, laststart,
+                                     b + 5 + nbytes,
+                                     lower_bound);
+                       b += 5;
+ 
+                       /* Code to initialize the lower bound.  Insert
+                          before the `succeed_n'.       The `5' is the last two
+                          bytes of this `set_number_at', plus 3 bytes of
+                          the following `succeed_n'.  */
+                       insert_op2 (set_number_at, laststart, 5, lower_bound, 
b);
+                       b += 5;
+                       startoffset += 5;
+                     }
+ 
+                   if (upper_bound < 0)
+                     {
+                       /* A negative upper bound stands for infinity,
+                          in which case it degenerates to a plain jump.  */
+                       STORE_JUMP (jump, b, laststart + startoffset);
+                       b += 3;
+                     }
+                   else if (upper_bound > 1)
+                     { /* More than one repetition is allowed, so
+                          append a backward jump to the `succeed_n'
+                          that starts this interval.
+ 
+                          When we've reached this during matching,
+                          we'll have matched the interval once, so
+                          jump back only `upper_bound - 1' times.  */
+                       STORE_JUMP2 (jump_n, b, laststart + startoffset,
+                                    upper_bound - 1);
+                       b += 5;
+ 
+                       /* The location we want to set is the second
+                          parameter of the `jump_n'; that is `b-2' as
+                          an absolute address.  `laststart' will be
+                          the `set_number_at' we're about to insert;
+                          `laststart+3' the number to set, the source
+                          for the relative address.  But we are
+                          inserting into the middle of the pattern --
+                          so everything is getting moved up by 5.
+                          Conclusion: (b - 2) - (laststart + 3) + 5,
+                          i.e., b - laststart.
+ 
+                          We insert this at the beginning of the loop
+                          so that if we fail during matching, we'll
+                          reinitialize the bounds.  */
+                       insert_op2 (set_number_at, laststart, b - laststart,
+                                   upper_bound - 1, b);
+                       b += 5;
+                     }
+                 }
+               pending_exact = 0;
+               beg_interval = NULL;
+             }
+             break;
+ 
+           unfetch_interval:
+             /* If an invalid interval, match the characters as literals.  */
+              assert (beg_interval);
+              p = beg_interval;
+              beg_interval = NULL;
+ 
+              /* normal_char and normal_backslash need `c'.  */
+              c = '{';
+ 
+              if (!(syntax & RE_NO_BK_BRACES))
+                {
+                  assert (p > pattern && p[-1] == '\\');
+                  goto normal_backslash;
+                }
+              else
+                goto normal_char;
+ 
+ #ifdef emacs
+           /* There is no way to specify the before_dot and after_dot
+              operators.  rms says this is ok.  --karl  */
+           case '=':
+             BUF_PUSH (at_dot);
+             break;
+ 
+           case 's':
+             laststart = b;
+             PATFETCH (c);
+             BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
+             break;
+ 
+           case 'S':
+             laststart = b;
+             PATFETCH (c);
+             BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
+             break;
+ 
+           case 'c':
+             laststart = b;
+             PATFETCH (c);
+             BUF_PUSH_2 (categoryspec, c);
+             break;
+ 
+           case 'C':
+             laststart = b;
+             PATFETCH (c);
+             BUF_PUSH_2 (notcategoryspec, c);
+             break;
+ #endif /* emacs */
+ 
+ 
+           case 'w':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             laststart = b;
+             BUF_PUSH_2 (syntaxspec, Sword);
+             break;
+ 
+ 
+           case 'W':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             laststart = b;
+             BUF_PUSH_2 (notsyntaxspec, Sword);
+             break;
+ 
+ 
+           case '<':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             BUF_PUSH (wordbeg);
+             break;
+ 
+           case '>':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             BUF_PUSH (wordend);
+             break;
+ 
+           case 'b':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             BUF_PUSH (wordbound);
+             break;
+ 
+           case 'B':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             BUF_PUSH (notwordbound);
+             break;
+ 
+           case '`':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             BUF_PUSH (begbuf);
+             break;
+ 
+           case '\'':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+             BUF_PUSH (endbuf);
+             break;
+ 
+           case '1': case '2': case '3': case '4': case '5':
+           case '6': case '7': case '8': case '9':
+             {
+               regnum_t reg;
+ 
+               if (syntax & RE_NO_BK_REFS)
+                 goto normal_backslash;
+ 
+               reg = c - '0';
+ 
+               /* Can't back reference to a subexpression before its end.  */
+               if (reg > regnum || group_in_compile_stack (compile_stack, reg))
+                 FREE_STACK_RETURN (REG_ESUBREG);
+ 
+               laststart = b;
+               BUF_PUSH_2 (duplicate, reg);
+             }
+             break;
+ 
+ 
+           case '+':
+           case '?':
+             if (syntax & RE_BK_PLUS_QM)
+               goto handle_plus;
+             else
+               goto normal_backslash;
+ 
+           default:
+           normal_backslash:
+             /* You might think it would be useful for \ to mean
+                not to translate; but if we don't translate it
+                it will never match anything.  */
+             goto normal_char;
+           }
+         break;
+ 
+ 
+       default:
+       /* Expects the character in `c'.  */
+       normal_char:
+         /* If no exactn currently being built.  */
+         if (!pending_exact
+ 
+             /* If last exactn not at current position.  */
+             || pending_exact + *pending_exact + 1 != b
+ 
+             /* We have only one byte following the exactn for the count.  */
+             || *pending_exact >= (1 << BYTEWIDTH) - MAX_MULTIBYTE_LENGTH
+ 
+             /* If followed by a repetition operator.  */
+             || (p != pend && (*p == '*' || *p == '^'))
+             || ((syntax & RE_BK_PLUS_QM)
+                 ? p + 1 < pend && *p == '\\' && (p[1] == '+' || p[1] == '?')
+                 : p != pend && (*p == '+' || *p == '?'))
+             || ((syntax & RE_INTERVALS)
+                 && ((syntax & RE_NO_BK_BRACES)
+                     ? p != pend && *p == '{'
+                     : p + 1 < pend && p[0] == '\\' && p[1] == '{')))
+           {
+             /* Start building a new exactn.  */
+ 
+             laststart = b;
+ 
+             BUF_PUSH_2 (exactn, 0);
+             pending_exact = b - 1;
+           }
+ 
+         GET_BUFFER_SPACE (MAX_MULTIBYTE_LENGTH);
+         {
+           int len;
+ 
+           if (! multibyte)
+             MAKE_CHAR_MULTIBYTE (c);
+           c = TRANSLATE (c);
+           if (target_multibyte)
+             {
+               len = CHAR_STRING (c, b);
+               b += len;
+             }
+           else
+             {
+               MAKE_CHAR_UNIBYTE (c);
+               *b++ = c;
+               len = 1;
+             }
+           (*pending_exact) += len;
+         }
+ 
+         break;
+       } /* switch (c) */
+     } /* while p != pend */
+ 
+ 
+   /* Through the pattern now.  */
+ 
+   FIXUP_ALT_JUMP ();
+ 
+   if (!COMPILE_STACK_EMPTY)
+     FREE_STACK_RETURN (REG_EPAREN);
+ 
+   /* If we don't want backtracking, force success
+      the first time we reach the end of the compiled pattern.  */
+   if (syntax & RE_NO_POSIX_BACKTRACKING)
+     BUF_PUSH (succeed);
+ 
+   free (compile_stack.stack);
+ 
+   /* We have succeeded; set the length of the buffer.  */
+   bufp->used = b - bufp->buffer;
+ 
+ #ifdef emacs
+   /* Now the buffer is adjusted for the multibyteness of a target.  */
+   bufp->multibyte = bufp->target_multibyte;
+ #endif
+ 
+ #ifdef DEBUG
+   if (debug > 0)
+     {
+       re_compile_fastmap (bufp);
+       DEBUG_PRINT1 ("\nCompiled pattern: \n");
+       print_compiled_pattern (bufp);
+     }
+   debug--;
+ #endif /* DEBUG */
+ 
+ #ifndef MATCH_MAY_ALLOCATE
+   /* Initialize the failure stack to the largest possible stack.  This
+      isn't necessary unless we're trying to avoid calling alloca in
+      the search and match routines.  */
+   {
+     int num_regs = bufp->re_nsub + 1;
+ 
+     if (fail_stack.size < re_max_failures * TYPICAL_FAILURE_SIZE)
+       {
+       fail_stack.size = re_max_failures * TYPICAL_FAILURE_SIZE;
+ 
+       if (! fail_stack.stack)
+         fail_stack.stack
+           = (fail_stack_elt_t *) malloc (fail_stack.size
+                                          * sizeof (fail_stack_elt_t));
+       else
+         fail_stack.stack
+           = (fail_stack_elt_t *) realloc (fail_stack.stack,
+                                           (fail_stack.size
+                                            * sizeof (fail_stack_elt_t)));
+       }
+ 
+     regex_grow_registers (num_regs);
+   }
+ #endif /* not MATCH_MAY_ALLOCATE */
+ 
+   return REG_NOERROR;
+ } /* regex_compile */
+ 
+ /* Subroutines for `regex_compile'.  */
+ 
+ /* Store OP at LOC followed by two-byte integer parameter ARG.        */
+ 
+ static void
+ store_op1 (op, loc, arg)
+     re_opcode_t op;
+     unsigned char *loc;
+     int arg;
+ {
+   *loc = (unsigned char) op;
+   STORE_NUMBER (loc + 1, arg);
+ }
+ 
+ 
+ /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2.  */
+ 
+ static void
+ store_op2 (op, loc, arg1, arg2)
+     re_opcode_t op;
+     unsigned char *loc;
+     int arg1, arg2;
+ {
+   *loc = (unsigned char) op;
+   STORE_NUMBER (loc + 1, arg1);
+   STORE_NUMBER (loc + 3, arg2);
+ }
+ 
+ 
+ /* Copy the bytes from LOC to END to open up three bytes of space at LOC
+    for OP followed by two-byte integer parameter ARG.  */
+ 
+ static void
+ insert_op1 (op, loc, arg, end)
+     re_opcode_t op;
+     unsigned char *loc;
+     int arg;
+     unsigned char *end;
+ {
+   register unsigned char *pfrom = end;
+   register unsigned char *pto = end + 3;
+ 
+   while (pfrom != loc)
+     *--pto = *--pfrom;
+ 
+   store_op1 (op, loc, arg);
+ }
+ 
+ 
+ /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2.  */
+ 
+ static void
+ insert_op2 (op, loc, arg1, arg2, end)
+     re_opcode_t op;
+     unsigned char *loc;
+     int arg1, arg2;
+     unsigned char *end;
+ {
+   register unsigned char *pfrom = end;
+   register unsigned char *pto = end + 5;
+ 
+   while (pfrom != loc)
+     *--pto = *--pfrom;
+ 
+   store_op2 (op, loc, arg1, arg2);
+ }
+ 
+ 
+ /* P points to just after a ^ in PATTERN.  Return true if that ^ comes
+    after an alternative or a begin-subexpression.  We assume there is at
+    least one character before the ^.  */
+ 
+ static boolean
+ at_begline_loc_p (pattern, p, syntax)
+     re_char *pattern, *p;
+     reg_syntax_t syntax;
+ {
+   re_char *prev = p - 2;
+   boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';
+ 
+   return
+        /* After a subexpression?  */
+        (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
+        /* After an alternative?        */
+     || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash))
+        /* After a shy subexpression?  */
+     || ((syntax & RE_SHY_GROUPS) && prev - 2 >= pattern
+       && prev[-1] == '?' && prev[-2] == '('
+       && (syntax & RE_NO_BK_PARENS
+           || (prev - 3 >= pattern && prev[-3] == '\\')));
+ }
+ 
+ 
+ /* The dual of at_begline_loc_p.  This one is for $.  We assume there is
+    at least one character after the $, i.e., `P < PEND'.  */
+ 
+ static boolean
+ at_endline_loc_p (p, pend, syntax)
+     re_char *p, *pend;
+     reg_syntax_t syntax;
+ {
+   re_char *next = p;
+   boolean next_backslash = *next == '\\';
+   re_char *next_next = p + 1 < pend ? p + 1 : 0;
+ 
+   return
+        /* Before a subexpression?  */
+        (syntax & RE_NO_BK_PARENS ? *next == ')'
+       : next_backslash && next_next && *next_next == ')')
+        /* Before an alternative?  */
+     || (syntax & RE_NO_BK_VBAR ? *next == '|'
+       : next_backslash && next_next && *next_next == '|');
+ }
+ 
+ 
+ /* Returns true if REGNUM is in one of COMPILE_STACK's elements and
+    false if it's not.  */
+ 
+ static boolean
+ group_in_compile_stack (compile_stack, regnum)
+     compile_stack_type compile_stack;
+     regnum_t regnum;
+ {
+   int this_element;
+ 
+   for (this_element = compile_stack.avail - 1;
+        this_element >= 0;
+        this_element--)
+     if (compile_stack.stack[this_element].regnum == regnum)
+       return true;
+ 
+   return false;
+ }
+ 
+ /* analyse_first.
+    If fastmap is non-NULL, go through the pattern and fill fastmap
+    with all the possible leading chars.  If fastmap is NULL, don't
+    bother filling it up (obviously) and only return whether the
+    pattern could potentially match the empty string.
+ 
+    Return 1  if p..pend might match the empty string.
+    Return 0  if p..pend matches at least one char.
+    Return -1 if fastmap was not updated accurately.  */
+ 
+ static int
+ analyse_first (p, pend, fastmap, multibyte)
+      re_char *p, *pend;
+      char *fastmap;
+      const int multibyte;
+ {
+   int j, k;
+   boolean not;
+ 
+   /* If all elements for base leading-codes in fastmap is set, this
+      flag is set true.        */
+   boolean match_any_multibyte_characters = false;
+ 
+   assert (p);
+ 
+   /* The loop below works as follows:
+      - It has a working-list kept in the PATTERN_STACK and which basically
+        starts by only containing a pointer to the first operation.
+      - If the opcode we're looking at is a match against some set of
+        chars, then we add those chars to the fastmap and go on to the
+        next work element from the worklist (done via `break').
+      - If the opcode is a control operator on the other hand, we either
+        ignore it (if it's meaningless at this point, such as `start_memory')
+        or execute it (if it's a jump).  If the jump has several destinations
+        (i.e. `on_failure_jump'), then we push the other destination onto the
+        worklist.
+      We guarantee termination by ignoring backward jumps (more or less),
+      so that `p' is monotonically increasing.  More to the point, we
+      never set `p' (or push) anything `<= p1'.  */
+ 
+   while (p < pend)
+     {
+       /* `p1' is used as a marker of how far back a `on_failure_jump'
+        can go without being ignored.  It is normally equal to `p'
+        (which prevents any backward `on_failure_jump') except right
+        after a plain `jump', to allow patterns such as:
+           0: jump 10
+           3..9: <body>
+           10: on_failure_jump 3
+        as used for the *? operator.  */
+       re_char *p1 = p;
+ 
+       switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
+       {
+       case succeed:
+         return 1;
+         continue;
+ 
+       case duplicate:
+         /* If the first character has to match a backreference, that means
+            that the group was empty (since it already matched).  Since this
+            is the only case that interests us here, we can assume that the
+            backreference must match the empty string.  */
+         p++;
+         continue;
+ 
+ 
+       /* Following are the cases which match a character.  These end
+        with `break'.  */
+ 
+       case exactn:
+         if (fastmap)
+           /* If multibyte is nonzero, the first byte of each
+              character is an ASCII or a leading code.  Otherwise,
+              each byte is a character.  Thus, this works in both
+              cases. */
+           fastmap[p[1]] = 1;
+         break;
+ 
+ 
+       case anychar:
+         /* We could put all the chars except for \n (and maybe \0)
+            but we don't bother since it is generally not worth it.  */
+         if (!fastmap) break;
+         return -1;
+ 
+ 
+       case charset_not:
+         if (!fastmap) break;
+         {
+           /* Chars beyond end of bitmap are possible matches.  */
+           /* In a multibyte case, the bitmap is used only for ASCII
+              characters.  */
+           int limit = multibyte ? 128 : (1 << BYTEWIDTH);
+ 
+           for (j = CHARSET_BITMAP_SIZE (&p[-1]) * BYTEWIDTH;
+                j < limit; j++)
+             fastmap[j] = 1;
+         }
+ 
+         /* Fallthrough */
+       case charset:
+         if (!fastmap) break;
+         not = (re_opcode_t) *(p - 1) == charset_not;
+         for (j = CHARSET_BITMAP_SIZE (&p[-1]) * BYTEWIDTH - 1, p++;
+              j >= 0; j--)
+           if (!!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))) ^ not)
+             fastmap[j] = 1;
+ 
+         if ((not && multibyte)
+             /* Any leading code can possibly start a character
+                which doesn't match the specified set of characters.  */
+             || (CHARSET_RANGE_TABLE_EXISTS_P (&p[-2])
+                 && CHARSET_RANGE_TABLE_BITS (&p[-2]) != 0))
+           /* If we can match a character class, we can match
+              any multibyte characters.  */
+           {
+             if (match_any_multibyte_characters == false)
+               {
+                 for (j = 0x80; j < (1 << BYTEWIDTH); j++)
+                   fastmap[j] = 1;
+                 match_any_multibyte_characters = true;
+               }
+           }
+ 
+         else if (!not && CHARSET_RANGE_TABLE_EXISTS_P (&p[-2])
+                  && match_any_multibyte_characters == false)
+           {
+             /* Set fastmap[I] to 1 where I is a leading code of each
+                multibyte characer in the range table. */
+             int c, count;
+             unsigned char lc1, lc2;
+ 
+             /* Make P points the range table.  `+ 2' is to skip flag
+                bits for a character class.  */
+             p += CHARSET_BITMAP_SIZE (&p[-2]) + 2;
+ 
+             /* Extract the number of ranges in range table into COUNT.  */
+             EXTRACT_NUMBER_AND_INCR (count, p);
+             for (; count > 0; count--, p += 2 * 3) /* XXX */
+               {
+                 /* Extract the start and end of each range.  */
+                 EXTRACT_CHARACTER (c, p);
+                 lc1 = CHAR_LEADING_CODE (c);
+                 p += 3;
+                 EXTRACT_CHARACTER (c, p);
+                 lc2 = CHAR_LEADING_CODE (c);
+                 for (j = lc1; j <= lc2; j++)
+                   fastmap[j] = 1;
+               }
+           }
+         break;
+ 
+       case syntaxspec:
+       case notsyntaxspec:
+         if (!fastmap) break;
+ #ifndef emacs
+         not = (re_opcode_t)p[-1] == notsyntaxspec;
+         k = *p++;
+         for (j = 0; j < (1 << BYTEWIDTH); j++)
+           if ((SYNTAX (j) == (enum syntaxcode) k) ^ not)
+             fastmap[j] = 1;
+         break;
+ #else  /* emacs */
+         /* This match depends on text properties.  These end with
+            aborting optimizations.  */
+         return -1;
+ 
+       case categoryspec:
+       case notcategoryspec:
+         if (!fastmap) break;
+         not = (re_opcode_t)p[-1] == notcategoryspec;
+         k = *p++;
+         for (j = (multibyte ? 127 : (1 << BYTEWIDTH)); j >= 0; j--)
+           if ((CHAR_HAS_CATEGORY (j, k)) ^ not)
+             fastmap[j] = 1;
+ 
+         if (multibyte)
+           {
+             /* Any character set can possibly contain a character
+                whose category is K (or not).  */
+             if (match_any_multibyte_characters == false)
+               {
+                 for (j = 0x80; j < (1 << BYTEWIDTH); j++)
+                   fastmap[j] = 1;
+                 match_any_multibyte_characters = true;
+               }
+           }
+         break;
+ 
+       /* All cases after this match the empty string.  These end with
+        `continue'.  */
+ 
+       case before_dot:
+       case at_dot:
+       case after_dot:
+ #endif /* !emacs */
+       case no_op:
+       case begline:
+       case endline:
+       case begbuf:
+       case endbuf:
+       case wordbound:
+       case notwordbound:
+       case wordbeg:
+       case wordend:
+         continue;
+ 
+ 
+       case jump:
+         EXTRACT_NUMBER_AND_INCR (j, p);
+         if (j < 0)
+           /* Backward jumps can only go back to code that we've already
+              visited.  `re_compile' should make sure this is true.  */
+           break;
+         p += j;
+         switch (SWITCH_ENUM_CAST ((re_opcode_t) *p))
+           {
+           case on_failure_jump:
+           case on_failure_keep_string_jump:
+           case on_failure_jump_loop:
+           case on_failure_jump_nastyloop:
+           case on_failure_jump_smart:
+             p++;
+             break;
+           default:
+             continue;
+           };
+         /* Keep `p1' to allow the `on_failure_jump' we are jumping to
+            to jump back to "just after here".  */
+         /* Fallthrough */
+ 
+       case on_failure_jump:
+       case on_failure_keep_string_jump:
+       case on_failure_jump_nastyloop:
+       case on_failure_jump_loop:
+       case on_failure_jump_smart:
+         EXTRACT_NUMBER_AND_INCR (j, p);
+         if (p + j <= p1)
+           ; /* Backward jump to be ignored.  */
+         else
+           { /* We have to look down both arms.
+                We first go down the "straight" path so as to minimize
+                stack usage when going through alternatives.  */
+             int r = analyse_first (p, pend, fastmap, multibyte);
+             if (r) return r;
+             p += j;
+           }
+         continue;
+ 
+ 
+       case jump_n:
+         /* This code simply does not properly handle forward jump_n.  */
+         DEBUG_STATEMENT (EXTRACT_NUMBER (j, p); assert (j < 0));
+         p += 4;
+         /* jump_n can either jump or fall through.  The (backward) jump
+            case has already been handled, so we only need to look at the
+            fallthrough case.  */
+         continue;
+ 
+       case succeed_n:
+         /* If N == 0, it should be an on_failure_jump_loop instead.  */
+         DEBUG_STATEMENT (EXTRACT_NUMBER (j, p + 2); assert (j > 0));
+         p += 4;
+         /* We only care about one iteration of the loop, so we don't
+            need to consider the case where this behaves like an
+            on_failure_jump.  */
+         continue;
+ 
+ 
+       case set_number_at:
+         p += 4;
+         continue;
+ 
+ 
+       case start_memory:
+       case stop_memory:
+         p += 1;
+         continue;
+ 
+ 
+       default:
+         abort (); /* We have listed all the cases.  */
+       } /* switch *p++ */
+ 
+       /* Getting here means we have found the possible starting
+        characters for one path of the pattern -- and that the empty
+        string does not match.  We need not follow this path further.  */
+       return 0;
+     } /* while p */
+ 
+   /* We reached the end without matching anything.  */
+   return 1;
+ 
+ } /* analyse_first */
+ 
+ /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
+    BUFP.  A fastmap records which of the (1 << BYTEWIDTH) possible
+    characters can start a string that matches the pattern.  This fastmap
+    is used by re_search to skip quickly over impossible starting points.
+ 
+    Character codes above (1 << BYTEWIDTH) are not represented in the
+    fastmap, but the leading codes are represented.  Thus, the fastmap
+    indicates which character sets could start a match.
+ 
+    The caller must supply the address of a (1 << BYTEWIDTH)-byte data
+    area as BUFP->fastmap.
+ 
+    We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
+    the pattern buffer.
+ 
+    Returns 0 if we succeed, -2 if an internal error.   */
+ 
+ int
+ re_compile_fastmap (bufp)
+      struct re_pattern_buffer *bufp;
+ {
+   char *fastmap = bufp->fastmap;
+   int analysis;
+ 
+   assert (fastmap && bufp->buffer);
+ 
+   bzero (fastmap, 1 << BYTEWIDTH);  /* Assume nothing's valid.        */
+   bufp->fastmap_accurate = 1;     /* It will be when we're done.  */
+ 
+   analysis = analyse_first (bufp->buffer, bufp->buffer + bufp->used,
+                           fastmap, RE_MULTIBYTE_P (bufp));
+   bufp->can_be_null = (analysis != 0);
+   return 0;
+ } /* re_compile_fastmap */
+ 
+ /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+    ENDS.  Subsequent matches using PATTERN_BUFFER and REGS will use
+    this memory for recording register information.  STARTS and ENDS
+    must be allocated using the malloc library routine, and must each
+    be at least NUM_REGS * sizeof (regoff_t) bytes long.
+ 
+    If NUM_REGS == 0, then subsequent matches should allocate their own
+    register data.
+ 
+    Unless this function is called, the first search or match using
+    PATTERN_BUFFER will allocate its own register data, without
+    freeing the old data.  */
+ 
+ void
+ re_set_registers (bufp, regs, num_regs, starts, ends)
+     struct re_pattern_buffer *bufp;
+     struct re_registers *regs;
+     unsigned num_regs;
+     regoff_t *starts, *ends;
+ {
+   if (num_regs)
+     {
+       bufp->regs_allocated = REGS_REALLOCATE;
+       regs->num_regs = num_regs;
+       regs->start = starts;
+       regs->end = ends;
+     }
+   else
+     {
+       bufp->regs_allocated = REGS_UNALLOCATED;
+       regs->num_regs = 0;
+       regs->start = regs->end = (regoff_t *) 0;
+     }
+ }
+ WEAK_ALIAS (__re_set_registers, re_set_registers)
+ 
+ /* Searching routines.        */
+ 
+ /* Like re_search_2, below, but only one string is specified, and
+    doesn't let you say where to stop matching. */
+ 
+ int
+ re_search (bufp, string, size, startpos, range, regs)
+      struct re_pattern_buffer *bufp;
+      const char *string;
+      int size, startpos, range;
+      struct re_registers *regs;
+ {
+   return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
+                     regs, size);
+ }
+ WEAK_ALIAS (__re_search, re_search)
+ 
+ /* Head address of virtual concatenation of string.  */
+ #define HEAD_ADDR_VSTRING(P)          \
+   (((P) >= size1 ? string2 : string1))
+ 
+ /* End address of virtual concatenation of string.  */
+ #define STOP_ADDR_VSTRING(P)                          \
+   (((P) >= size1 ? string2 + size2 : string1 + size1))
+ 
+ /* Address of POS in the concatenation of virtual string. */
+ #define POS_ADDR_VSTRING(POS)                                 \
+   (((POS) >= size1 ? string2 - size1 : string1) + (POS))
+ 
+ /* Using the compiled pattern in BUFP->buffer, first tries to match the
+    virtual concatenation of STRING1 and STRING2, starting first at index
+    STARTPOS, then at STARTPOS + 1, and so on.
+ 
+    STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.
+ 
+    RANGE is how far to scan while trying to match.  RANGE = 0 means try
+    only at STARTPOS; in general, the last start tried is STARTPOS +
+    RANGE.
+ 
+    In REGS, return the indices of the virtual concatenation of STRING1
+    and STRING2 that matched the entire BUFP->buffer and its contained
+    subexpressions.
+ 
+    Do not consider matching one past the index STOP in the virtual
+    concatenation of STRING1 and STRING2.
+ 
+    We return either the position in the strings at which the match was
+    found, -1 if no match, or -2 if error (such as failure
+    stack overflow).  */
+ 
+ int
+ re_search_2 (bufp, str1, size1, str2, size2, startpos, range, regs, stop)
+      struct re_pattern_buffer *bufp;
+      const char *str1, *str2;
+      int size1, size2;
+      int startpos;
+      int range;
+      struct re_registers *regs;
+      int stop;
+ {
+   int val;
+   re_char *string1 = (re_char*) str1;
+   re_char *string2 = (re_char*) str2;
+   register char *fastmap = bufp->fastmap;
+   register RE_TRANSLATE_TYPE translate = bufp->translate;
+   int total_size = size1 + size2;
+   int endpos = startpos + range;
+   boolean anchored_start;
+   /* Nonzero if BUFP is setup for multibyte characters.  We are sure
+      that it is the same as RE_TARGET_MULTIBYTE_P (bufp).  */
+   const boolean multibyte = RE_MULTIBYTE_P (bufp);
+ 
+   /* Check for out-of-range STARTPOS.  */
+   if (startpos < 0 || startpos > total_size)
+     return -1;
+ 
+   /* Fix up RANGE if it might eventually take us outside
+      the virtual concatenation of STRING1 and STRING2.
+      Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE.  */
+   if (endpos < 0)
+     range = 0 - startpos;
+   else if (endpos > total_size)
+     range = total_size - startpos;
+ 
+   /* If the search isn't to be a backwards one, don't waste time in a
+      search for a pattern anchored at beginning of buffer.  */
+   if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
+     {
+       if (startpos > 0)
+       return -1;
+       else
+       range = 0;
+     }
+ 
+ #ifdef emacs
+   /* In a forward search for something that starts with \=.
+      don't keep searching past point.  */
+   if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0)
+     {
+       range = PT_BYTE - BEGV_BYTE - startpos;
+       if (range < 0)
+       return -1;
+     }
+ #endif /* emacs */
+ 
+   /* Update the fastmap now if not correct already.  */
+   if (fastmap && !bufp->fastmap_accurate)
+     re_compile_fastmap (bufp);
+ 
+   /* See whether the pattern is anchored.  */
+   anchored_start = (bufp->buffer[0] == begline);
+ 
+ #ifdef emacs
+   gl_state.object = re_match_object;
+   {
+     int charpos = SYNTAX_TABLE_BYTE_TO_CHAR (POS_AS_IN_BUFFER (startpos));
+ 
+     SETUP_SYNTAX_TABLE_FOR_OBJECT (re_match_object, charpos, 1);
+   }
+ #endif
+ 
+   /* Loop through the string, looking for a place to start matching.  */
+   for (;;)
+     {
+       /* If the pattern is anchored,
+        skip quickly past places we cannot match.
+        We don't bother to treat startpos == 0 specially
+        because that case doesn't repeat.  */
+       if (anchored_start && startpos > 0)
+       {
+         if (! ((startpos <= size1 ? string1[startpos - 1]
+                 : string2[startpos - size1 - 1])
+                == '\n'))
+           goto advance;
+       }
+ 
+       /* If a fastmap is supplied, skip quickly over characters that
+        cannot be the start of a match.  If the pattern can match the
+        null string, however, we don't need to skip characters; we want
+        the first null string.  */
+       if (fastmap && startpos < total_size && !bufp->can_be_null)
+       {
+         register re_char *d;
+         register re_wchar_t buf_ch;
+ 
+         d = POS_ADDR_VSTRING (startpos);
+ 
+         if (range > 0)        /* Searching forwards.  */
+           {
+             register int lim = 0;
+             int irange = range;
+ 
+             if (startpos < size1 && startpos + range >= size1)
+               lim = range - (size1 - startpos);
+ 
+             /* Written out as an if-else to avoid testing `translate'
+                inside the loop.  */
+             if (RE_TRANSLATE_P (translate))
+               {
+                 if (multibyte)
+                   while (range > lim)
+                     {
+                       int buf_charlen;
+ 
+                       buf_ch = STRING_CHAR_AND_LENGTH (d, range - lim,
+                                                        buf_charlen);
+                       buf_ch = RE_TRANSLATE (translate, buf_ch);
+                       if (fastmap[CHAR_LEADING_CODE (buf_ch)])
+                         break;
+ 
+                       range -= buf_charlen;
+                       d += buf_charlen;
+                     }
+                 else
+                   while (range > lim)
+                     {
+                       buf_ch = *d;
+                       MAKE_CHAR_MULTIBYTE (buf_ch);
+                       buf_ch = RE_TRANSLATE (translate, buf_ch);
+                       MAKE_CHAR_UNIBYTE (buf_ch);
+                       if (fastmap[buf_ch])
+                         break;
+                       d++;
+                       range--;
+                     }
+               }
+             else
+               {
+                 if (multibyte)
+                   while (range > lim)
+                     {
+                       int buf_charlen;
+ 
+                       buf_ch = STRING_CHAR_AND_LENGTH (d, range - lim,
+                                                        buf_charlen);
+                       if (fastmap[CHAR_LEADING_CODE (buf_ch)])
+                         break;
+                       range -= buf_charlen;
+                       d += buf_charlen;
+                     }
+                 else
+                   while (range > lim && !fastmap[*d])
+                     {
+                       d++;
+                       range--;
+                     }
+               }
+             startpos += irange - range;
+           }
+         else                          /* Searching backwards.  */
+           {
+             int room = (startpos >= size1
+                         ? size2 + size1 - startpos
+                         : size1 - startpos);
+             if (multibyte)
+               {
+                 buf_ch = STRING_CHAR (d, room);
+                 buf_ch = TRANSLATE (buf_ch);
+                 if (! fastmap[CHAR_LEADING_CODE (buf_ch)])
+                   goto advance;
+               }
+             else
+               {
+                 if (! fastmap[TRANSLATE (*d)])
+                   goto advance;
+               }
+           }
+       }
+ 
+       /* If can't match the null string, and that's all we have left, fail.  
*/
+       if (range >= 0 && startpos == total_size && fastmap
+         && !bufp->can_be_null)
+       return -1;
+ 
+       val = re_match_2_internal (bufp, string1, size1, string2, size2,
+                                startpos, regs, stop);
+ #ifndef REGEX_MALLOC
+ # ifdef C_ALLOCA
+       alloca (0);
+ # endif
+ #endif
+ 
+       if (val >= 0)
+       return startpos;
+ 
+       if (val == -2)
+       return -2;
+ 
+     advance:
+       if (!range)
+       break;
+       else if (range > 0)
+       {
+         /* Update STARTPOS to the next character boundary.  */
+         if (multibyte)
+           {
+             re_char *p = POS_ADDR_VSTRING (startpos);
+             re_char *pend = STOP_ADDR_VSTRING (startpos);
+             int len = MULTIBYTE_FORM_LENGTH (p, pend - p);
+ 
+             range -= len;
+             if (range < 0)
+               break;
+             startpos += len;
+           }
+         else
+           {
+             range--;
+             startpos++;
+           }
+       }
+       else
+       {
+         range++;
+         startpos--;
+ 
+         /* Update STARTPOS to the previous character boundary.  */
+         if (multibyte)
+           {
+             re_char *p = POS_ADDR_VSTRING (startpos) + 1;
+             re_char *p0 = p;
+             re_char *phead = HEAD_ADDR_VSTRING (startpos);
+ 
+             /* Find the head of multibyte form.  */
+             PREV_CHAR_BOUNDARY (p, phead);
+             range += p0 - 1 - p;
+             if (range > 0)
+               break;
+ 
+             startpos -= p0 - 1 - p;
+           }
+       }
+     }
+   return -1;
+ } /* re_search_2 */
+ WEAK_ALIAS (__re_search_2, re_search_2)
+ 
+ /* Declarations and macros for re_match_2.  */
+ 
+ static int bcmp_translate _RE_ARGS((re_char *s1, re_char *s2,
+                                   register int len,
+                                   RE_TRANSLATE_TYPE translate,
+                                   const int multibyte));
+ 
+ /* This converts PTR, a pointer into one of the search strings `string1'
+    and `string2' into an offset from the beginning of that string.  */
+ #define POINTER_TO_OFFSET(ptr)                        \
+   (FIRST_STRING_P (ptr)                               \
+    ? ((regoff_t) ((ptr) - string1))           \
+    : ((regoff_t) ((ptr) - string2 + size1)))
+ 
+ /* Call before fetching a character with *d.  This switches over to
+    string2 if necessary.
+    Check re_match_2_internal for a discussion of why end_match_2 might
+    not be within string2 (but be equal to end_match_1 instead).  */
+ #define PREFETCH()                                                    \
+   while (d == dend)                                                   \
+     {                                                                 \
+       /* End of string2 => fail.  */                                  \
+       if (dend == end_match_2)                                                
\
+       goto fail;                                                      \
+       /* End of string1 => advance to string2.  */                    \
+       d = string2;                                                    \
+       dend = end_match_2;                                             \
+     }
+ 
+ /* Call before fetching a char with *d if you already checked other limits.
+    This is meant for use in lookahead operations like wordend, etc..
+    where we might need to look at parts of the string that might be
+    outside of the LIMITs (i.e past `stop').  */
+ #define PREFETCH_NOLIMIT()                                            \
+   if (d == end1)                                                      \
+      {                                                                        
\
+        d = string2;                                                   \
+        dend = end_match_2;                                            \
+      }                                                                        
\
+ 
+ /* Test if at very beginning or at very end of the virtual concatenation
+    of `string1' and `string2'.        If only one string, it's `string2'.  */
+ #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
+ #define AT_STRINGS_END(d) ((d) == end2)
+ 
+ 
+ /* Test if D points to a character which is word-constituent.  We have
+    two special cases to check for: if past the end of string1, look at
+    the first character in string2; and if before the beginning of
+    string2, look at the last character in string1.  */
+ #define WORDCHAR_P(d)                                                 \
+   (SYNTAX ((d) == end1 ? *string2                                     \
+          : (d) == string2 - 1 ? *(end1 - 1) : *(d))                   \
+    == Sword)
+ 
+ /* Disabled due to a compiler bug -- see comment at case wordbound */
+ 
+ /* The comment at case wordbound is following one, but we don't use
+    AT_WORD_BOUNDARY anymore to support multibyte form.
+ 
+    The DEC Alpha C compiler 3.x generates incorrect code for the
+    test        WORDCHAR_P (d - 1) != WORDCHAR_P (d)  in the expansion of
+    AT_WORD_BOUNDARY, so this code is disabled.        Expanding the
+    macro and introducing temporary variables works around the bug.  */
+ 
+ #if 0
+ /* Test if the character before D and the one at D differ with respect
+    to being word-constituent.  */
+ #define AT_WORD_BOUNDARY(d)                                           \
+   (AT_STRINGS_BEG (d) || AT_STRINGS_END (d)                           \
+    || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
+ #endif
+ 
+ /* Free everything we malloc.  */
+ #ifdef MATCH_MAY_ALLOCATE
+ # define FREE_VAR(var) if (var) { REGEX_FREE (var); var = NULL; } else
+ # define FREE_VARIABLES()                                             \
+   do {                                                                        
\
+     REGEX_FREE_STACK (fail_stack.stack);                              \
+     FREE_VAR (regstart);                                              \
+     FREE_VAR (regend);                                                        
\
+     FREE_VAR (best_regstart);                                         \
+     FREE_VAR (best_regend);                                           \
+   } while (0)
+ #else
+ # define FREE_VARIABLES() ((void)0) /* Do nothing!  But inhibit gcc warning.  
*/
+ #endif /* not MATCH_MAY_ALLOCATE */
+ 
+ 
+ /* Optimization routines.  */
+ 
+ /* If the operation is a match against one or more chars,
+    return a pointer to the next operation, else return NULL.  */
+ static re_char *
+ skip_one_char (p)
+      re_char *p;
+ {
+   switch (SWITCH_ENUM_CAST (*p++))
+     {
+     case anychar:
+       break;
+ 
+     case exactn:
+       p += *p + 1;
+       break;
+ 
+     case charset_not:
+     case charset:
+       if (CHARSET_RANGE_TABLE_EXISTS_P (p - 1))
+       {
+         int mcnt;
+         p = CHARSET_RANGE_TABLE (p - 1);
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);
+         p = CHARSET_RANGE_TABLE_END (p, mcnt);
+       }
+       else
+       p += 1 + CHARSET_BITMAP_SIZE (p - 1);
+       break;
+ 
+     case syntaxspec:
+     case notsyntaxspec:
+ #ifdef emacs
+     case categoryspec:
+     case notcategoryspec:
+ #endif /* emacs */
+       p++;
+       break;
+ 
+     default:
+       p = NULL;
+     }
+   return p;
+ }
+ 
+ 
+ /* Jump over non-matching operations.  */
+ static unsigned char *
+ skip_noops (p, pend)
+      unsigned char *p, *pend;
+ {
+   int mcnt;
+   while (p < pend)
+     {
+       switch (SWITCH_ENUM_CAST ((re_opcode_t) *p))
+       {
+       case start_memory:
+       case stop_memory:
+         p += 2; break;
+       case no_op:
+         p += 1; break;
+       case jump:
+         p += 1;
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);
+         p += mcnt;
+         break;
+       default:
+         return p;
+       }
+     }
+   assert (p == pend);
+   return p;
+ }
+ 
+ /* Non-zero if "p1 matches something" implies "p2 fails".  */
+ static int
+ mutually_exclusive_p (bufp, p1, p2)
+      struct re_pattern_buffer *bufp;
+      unsigned char *p1, *p2;
+ {
+   re_opcode_t op2;
+   const boolean multibyte = RE_MULTIBYTE_P (bufp);
+   unsigned char *pend = bufp->buffer + bufp->used;
+ 
+   assert (p1 >= bufp->buffer && p1 < pend
+         && p2 >= bufp->buffer && p2 <= pend);
+ 
+   /* Skip over open/close-group commands.
+      If what follows this loop is a ...+ construct,
+      look at what begins its body, since we will have to
+      match at least one of that.  */
+   p2 = skip_noops (p2, pend);
+   /* The same skip can be done for p1, except that this function
+      is only used in the case where p1 is a simple match operator.  */
+   /* p1 = skip_noops (p1, pend); */
+ 
+   assert (p1 >= bufp->buffer && p1 < pend
+         && p2 >= bufp->buffer && p2 <= pend);
+ 
+   op2 = p2 == pend ? succeed : *p2;
+ 
+   switch (SWITCH_ENUM_CAST (op2))
+     {
+     case succeed:
+     case endbuf:
+       /* If we're at the end of the pattern, we can change.  */
+       if (skip_one_char (p1))
+       {
+         DEBUG_PRINT1 ("  End of pattern: fast loop.\n");
+         return 1;
+       }
+       break;
+ 
+     case endline:
+     case exactn:
+       {
+       register re_wchar_t c
+         = (re_opcode_t) *p2 == endline ? '\n'
+         : RE_STRING_CHAR (p2 + 2, pend - p2 - 2);
+ 
+       if ((re_opcode_t) *p1 == exactn)
+         {
+           if (c != RE_STRING_CHAR (p1 + 2, pend - p1 - 2))
+             {
+               DEBUG_PRINT3 ("  '%c' != '%c' => fast loop.\n", c, p1[2]);
+               return 1;
+             }
+         }
+ 
+       else if ((re_opcode_t) *p1 == charset
+                || (re_opcode_t) *p1 == charset_not)
+         {
+           int not = (re_opcode_t) *p1 == charset_not;
+ 
+           /* Test if C is listed in charset (or charset_not)
+              at `p1'.  */
+           if (! multibyte || IS_REAL_ASCII (c))
+             {
+               if (c < CHARSET_BITMAP_SIZE (p1) * BYTEWIDTH
+                   && p1[2 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+                 not = !not;
+             }
+           else if (CHARSET_RANGE_TABLE_EXISTS_P (p1))
+             CHARSET_LOOKUP_RANGE_TABLE (not, c, p1);
+ 
+           /* `not' is equal to 1 if c would match, which means
+              that we can't change to pop_failure_jump.  */
+           if (!not)
+             {
+               DEBUG_PRINT1 ("  No match => fast loop.\n");
+               return 1;
+             }
+         }
+       else if ((re_opcode_t) *p1 == anychar
+                && c == '\n')
+         {
+           DEBUG_PRINT1 ("   . != \\n => fast loop.\n");
+           return 1;
+         }
+       }
+       break;
+ 
+     case charset:
+       {
+       if ((re_opcode_t) *p1 == exactn)
+         /* Reuse the code above.  */
+         return mutually_exclusive_p (bufp, p2, p1);
+ 
+       /* It is hard to list up all the character in charset
+        P2 if it includes multibyte character.  Give up in
+        such case.  */
+       else if (!multibyte || !CHARSET_RANGE_TABLE_EXISTS_P (p2))
+       {
+         /* Now, we are sure that P2 has no range table.
+            So, for the size of bitmap in P2, `p2[1]' is
+            enough.    But P1 may have range table, so the
+            size of bitmap table of P1 is extracted by
+            using macro `CHARSET_BITMAP_SIZE'.
+ 
+            In a multibyte case, we know that all the character
+            listed in P2 is ASCII.  In a unibyte case, P1 has only a
+            bitmap table.  So, in both cases, it is enough to test
+            only the bitmap table of P1.  */
+ 
+         if ((re_opcode_t) *p1 == charset)
+           {
+             int idx;
+             /* We win if the charset inside the loop
+                has no overlap with the one after the loop.  */
+             for (idx = 0;
+                  (idx < (int) p2[1]
+                   && idx < CHARSET_BITMAP_SIZE (p1));
+                  idx++)
+               if ((p2[2 + idx] & p1[2 + idx]) != 0)
+                 break;
+ 
+             if (idx == p2[1]
+                 || idx == CHARSET_BITMAP_SIZE (p1))
+               {
+                 DEBUG_PRINT1 ("        No match => fast loop.\n");
+                 return 1;
+               }
+           }
+         else if ((re_opcode_t) *p1 == charset_not)
+           {
+             int idx;
+             /* We win if the charset_not inside the loop lists
+                every character listed in the charset after.    */
+             for (idx = 0; idx < (int) p2[1]; idx++)
+               if (! (p2[2 + idx] == 0
+                      || (idx < CHARSET_BITMAP_SIZE (p1)
+                          && ((p2[2 + idx] & ~ p1[2 + idx]) == 0))))
+                 break;
+ 
+               if (idx == p2[1])
+                 {
+                   DEBUG_PRINT1 ("      No match => fast loop.\n");
+                   return 1;
+                 }
+             }
+         }
+       }
+       break;
+ 
+     case charset_not:
+       switch (SWITCH_ENUM_CAST (*p1))
+       {
+       case exactn:
+       case charset:
+         /* Reuse the code above.  */
+         return mutually_exclusive_p (bufp, p2, p1);
+       case charset_not:
+         /* When we have two charset_not, it's very unlikely that
+            they don't overlap.  The union of the two sets of excluded
+            chars should cover all possible chars, which, as a matter of
+            fact, is virtually impossible in multibyte buffers.  */
+         break;
+       }
+       break;
+ 
+     case wordend:
+     case notsyntaxspec:
+       return ((re_opcode_t) *p1 == syntaxspec
+             && p1[1] == (op2 == wordend ? Sword : p2[1]));
+ 
+     case wordbeg:
+     case syntaxspec:
+       return ((re_opcode_t) *p1 == notsyntaxspec
+             && p1[1] == (op2 == wordend ? Sword : p2[1]));
+ 
+     case wordbound:
+       return (((re_opcode_t) *p1 == notsyntaxspec
+              || (re_opcode_t) *p1 == syntaxspec)
+             && p1[1] == Sword);
+ 
+ #ifdef emacs
+     case categoryspec:
+       return ((re_opcode_t) *p1 == notcategoryspec && p1[1] == p2[1]);
+     case notcategoryspec:
+       return ((re_opcode_t) *p1 == categoryspec && p1[1] == p2[1]);
+ #endif /* emacs */
+ 
+     default:
+       ;
+     }
+ 
+   /* Safe default.  */
+   return 0;
+ }
+ 
+ 
+ /* Matching routines.  */
+ 
+ #ifndef emacs /* Emacs never uses this.  */
+ /* re_match is like re_match_2 except it takes only a single string.  */
+ 
+ int
+ re_match (bufp, string, size, pos, regs)
+      struct re_pattern_buffer *bufp;
+      const char *string;
+      int size, pos;
+      struct re_registers *regs;
+ {
+   int result = re_match_2_internal (bufp, NULL, 0, (re_char*) string, size,
+                                   pos, regs, size);
+ # if defined C_ALLOCA && !defined REGEX_MALLOC
+   alloca (0);
+ # endif
+   return result;
+ }
+ WEAK_ALIAS (__re_match, re_match)
+ #endif /* not emacs */
+ 
+ #ifdef emacs
+ /* In Emacs, this is the string or buffer in which we
+    are matching.  It is used for looking up syntax properties.        */
+ Lisp_Object re_match_object;
+ #endif
+ 
+ /* re_match_2 matches the compiled pattern in BUFP against the
+    the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
+    and SIZE2, respectively).  We start matching at POS, and stop
+    matching at STOP.
+ 
+    If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
+    store offsets for the substring each group matched in REGS.        See the
+    documentation for exactly how many groups we fill.
+ 
+    We return -1 if no match, -2 if an internal error (such as the
+    failure stack overflowing).        Otherwise, we return the length of the
+    matched substring.  */
+ 
+ int
+ re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
+      struct re_pattern_buffer *bufp;
+      const char *string1, *string2;
+      int size1, size2;
+      int pos;
+      struct re_registers *regs;
+      int stop;
+ {
+   int result;
+ 
+ #ifdef emacs
+   int charpos;
+   gl_state.object = re_match_object;
+   charpos = SYNTAX_TABLE_BYTE_TO_CHAR (POS_AS_IN_BUFFER (pos));
+   SETUP_SYNTAX_TABLE_FOR_OBJECT (re_match_object, charpos, 1);
+ #endif
+ 
+   result = re_match_2_internal (bufp, (re_char*) string1, size1,
+                               (re_char*) string2, size2,
+                               pos, regs, stop);
+ #if defined C_ALLOCA && !defined REGEX_MALLOC
+   alloca (0);
+ #endif
+   return result;
+ }
+ WEAK_ALIAS (__re_match_2, re_match_2)
+ 
+ #ifdef emacs
+ #define TRANSLATE_VIA_MULTIBYTE(c)    \
+   do {                                        \
+     if (multibyte)                    \
+       (c) = TRANSLATE (c);            \
+     else                              \
+       {                                       \
+       MAKE_CHAR_MULTIBYTE (c);        \
+       (c) = TRANSLATE (c);            \
+       MAKE_CHAR_UNIBYTE (c);          \
+       }                                       \
+   } while (0)
+ 
+ #else
+ #define TRANSLATE_VIA_MULTIBYTE(c) ((c) = TRANSLATE (c))
+ #endif
+ 
+ 
+ /* This is a separate function so that we can force an alloca cleanup
+    afterwards.        */
+ static int
+ re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
+      struct re_pattern_buffer *bufp;
+      re_char *string1, *string2;
+      int size1, size2;
+      int pos;
+      struct re_registers *regs;
+      int stop;
+ {
+   /* General temporaries.  */
+   int mcnt;
+   size_t reg;
+   boolean not;
+ 
+   /* Just past the end of the corresponding string.  */
+   re_char *end1, *end2;
+ 
+   /* Pointers into string1 and string2, just past the last characters in
+      each to consider matching.        */
+   re_char *end_match_1, *end_match_2;
+ 
+   /* Where we are in the data, and the end of the current string.  */
+   re_char *d, *dend;
+ 
+   /* Used sometimes to remember where we were before starting matching
+      an operator so that we can go back in case of failure.  This "atomic"
+      behavior of matching opcodes is indispensable to the correctness
+      of the on_failure_keep_string_jump optimization.  */
+   re_char *dfail;
+ 
+   /* Where we are in the pattern, and the end of the pattern.  */
+   re_char *p = bufp->buffer;
+   re_char *pend = p + bufp->used;
+ 
+   /* We use this to map every character in the string.        */
+   RE_TRANSLATE_TYPE translate = bufp->translate;
+ 
+   /* Nonzero if BUFP is setup for multibyte characters.  We are sure
+      that it is the same as RE_TARGET_MULTIBYTE_P (bufp).  */
+   const boolean multibyte = RE_MULTIBYTE_P (bufp);
+ 
+   /* Failure point stack.  Each place that can handle a failure further
+      down the line pushes a failure point on this stack.  It consists of
+      regstart, and regend for all registers corresponding to
+      the subexpressions we're currently inside, plus the number of such
+      registers, and, finally, two char *'s.  The first char * is where
+      to resume scanning the pattern; the second one is where to resume
+      scanning the strings.    */
+ #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.        */
+   fail_stack_type fail_stack;
+ #endif
+ #ifdef DEBUG
+   unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
+ #endif
+ 
+ #if defined REL_ALLOC && defined REGEX_MALLOC
+   /* This holds the pointer to the failure stack, when
+      it is allocated relocatably.  */
+   fail_stack_elt_t *failure_stack_ptr;
+ #endif
+ 
+   /* We fill all the registers internally, independent of what we
+      return, for use in backreferences.        The number here includes
+      an element for register zero.  */
+   size_t num_regs = bufp->re_nsub + 1;
+ 
+   /* Information on the contents of registers. These are pointers into
+      the input strings; they record just what was matched (on this
+      attempt) by a subexpression part of the pattern, that is, the
+      regnum-th regstart pointer points to where in the pattern we began
+      matching and the regnum-th regend points to right after where we
+      stopped matching the regnum-th subexpression.  (The zeroth register
+      keeps track of what the whole pattern matches.)  */
+ #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+   re_char **regstart, **regend;
+ #endif
+ 
+   /* The following record the register info as found in the above
+      variables when we find a match better than any we've seen before.
+      This happens as we backtrack through the failure points, which in
+      turn happens only if we have not yet matched the entire string. */
+   unsigned best_regs_set = false;
+ #ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+   re_char **best_regstart, **best_regend;
+ #endif
+ 
+   /* Logically, this is `best_regend[0]'.  But we don't want to have to
+      allocate space for that if we're not allocating space for anything
+      else (see below).        Also, we never need info about register 0 for
+      any of the other register vectors, and it seems rather a kludge to
+      treat `best_regend' differently than the rest.  So we keep track of
+      the end of the best match so far in a separate variable.  We
+      initialize this to NULL so that when we backtrack the first time
+      and need to test it, it's not garbage.  */
+   re_char *match_end = NULL;
+ 
+ #ifdef DEBUG
+   /* Counts the total number of registers pushed.  */
+   unsigned num_regs_pushed = 0;
+ #endif
+ 
+   DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");
+ 
+   INIT_FAIL_STACK ();
+ 
+ #ifdef MATCH_MAY_ALLOCATE
+   /* Do not bother to initialize all the register variables if there are
+      no groups in the pattern, as it takes a fair amount of time.  If
+      there are groups, we include space for register 0 (the whole
+      pattern), even though we never use it, since it simplifies the
+      array indexing.  We should fix this.  */
+   if (bufp->re_nsub)
+     {
+       regstart = REGEX_TALLOC (num_regs, re_char *);
+       regend = REGEX_TALLOC (num_regs, re_char *);
+       best_regstart = REGEX_TALLOC (num_regs, re_char *);
+       best_regend = REGEX_TALLOC (num_regs, re_char *);
+ 
+       if (!(regstart && regend && best_regstart && best_regend))
+       {
+         FREE_VARIABLES ();
+         return -2;
+       }
+     }
+   else
+     {
+       /* We must initialize all our variables to NULL, so that
+        `FREE_VARIABLES' doesn't try to free them.  */
+       regstart = regend = best_regstart = best_regend = NULL;
+     }
+ #endif /* MATCH_MAY_ALLOCATE */
+ 
+   /* The starting position is bogus.  */
+   if (pos < 0 || pos > size1 + size2)
+     {
+       FREE_VARIABLES ();
+       return -1;
+     }
+ 
+   /* Initialize subexpression text positions to -1 to mark ones that no
+      start_memory/stop_memory has been seen for. Also initialize the
+      register information struct.  */
+   for (reg = 1; reg < num_regs; reg++)
+     regstart[reg] = regend[reg] = NULL;
+ 
+   /* We move `string1' into `string2' if the latter's empty -- but not if
+      `string1' is null.        */
+   if (size2 == 0 && string1 != NULL)
+     {
+       string2 = string1;
+       size2 = size1;
+       string1 = 0;
+       size1 = 0;
+     }
+   end1 = string1 + size1;
+   end2 = string2 + size2;
+ 
+   /* `p' scans through the pattern as `d' scans through the data.
+      `dend' is the end of the input string that `d' points within.  `d'
+      is advanced into the following input string whenever necessary, but
+      this happens before fetching; therefore, at the beginning of the
+      loop, `d' can be pointing at the end of a string, but it cannot
+      equal `string2'.  */
+   if (pos >= size1)
+     {
+       /* Only match within string2.  */
+       d = string2 + pos - size1;
+       dend = end_match_2 = string2 + stop - size1;
+       end_match_1 = end1;     /* Just to give it a value.  */
+     }
+   else
+     {
+       if (stop < size1)
+       {
+         /* Only match within string1.  */
+         end_match_1 = string1 + stop;
+         /* BEWARE!
+            When we reach end_match_1, PREFETCH normally switches to string2.
+            But in the present case, this means that just doing a PREFETCH
+            makes us jump from `stop' to `gap' within the string.
+            What we really want here is for the search to stop as
+            soon as we hit end_match_1.  That's why we set end_match_2
+            to end_match_1 (since PREFETCH fails as soon as we hit
+            end_match_2).  */
+         end_match_2 = end_match_1;
+       }
+       else
+       { /* It's important to use this code when stop == size so that
+            moving `d' from end1 to string2 will not prevent the d == dend
+            check from catching the end of string.  */
+         end_match_1 = end1;
+         end_match_2 = string2 + stop - size1;
+       }
+       d = string1 + pos;
+       dend = end_match_1;
+     }
+ 
+   DEBUG_PRINT1 ("The compiled pattern is: ");
+   DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
+   DEBUG_PRINT1 ("The string to match is: `");
+   DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
+   DEBUG_PRINT1 ("'\n");
+ 
+   /* This loops over pattern commands.        It exits by returning from the
+      function if the match is complete, or it drops through if the match
+      fails at this starting point in the input data.  */
+   for (;;)
+     {
+       DEBUG_PRINT2 ("\n%p: ", p);
+ 
+       if (p == pend)
+       { /* End of pattern means we might have succeeded.  */
+         DEBUG_PRINT1 ("end of pattern ... ");
+ 
+         /* If we haven't matched the entire string, and we want the
+            longest match, try backtracking.  */
+         if (d != end_match_2)
+           {
+             /* 1 if this match ends in the same string (string1 or string2)
+                as the best previous match.  */
+             boolean same_str_p = (FIRST_STRING_P (match_end)
+                                   == FIRST_STRING_P (d));
+             /* 1 if this match is the best seen so far.  */
+             boolean best_match_p;
+ 
+             /* AIX compiler got confused when this was combined
+                with the previous declaration.  */
+             if (same_str_p)
+               best_match_p = d > match_end;
+             else
+               best_match_p = !FIRST_STRING_P (d);
+ 
+             DEBUG_PRINT1 ("backtracking.\n");
+ 
+             if (!FAIL_STACK_EMPTY ())
+               { /* More failure points to try.  */
+ 
+                 /* If exceeds best match so far, save it.  */
+                 if (!best_regs_set || best_match_p)
+                   {
+                     best_regs_set = true;
+                     match_end = d;
+ 
+                     DEBUG_PRINT1 ("\nSAVING match as best so far.\n");
+ 
+                     for (reg = 1; reg < num_regs; reg++)
+                       {
+                         best_regstart[reg] = regstart[reg];
+                         best_regend[reg] = regend[reg];
+                       }
+                   }
+                 goto fail;
+               }
+ 
+             /* If no failure points, don't restore garbage.  And if
+                last match is real best match, don't restore second
+                best one. */
+             else if (best_regs_set && !best_match_p)
+               {
+               restore_best_regs:
+                 /* Restore best match.  It may happen that `dend ==
+                    end_match_1' while the restored d is in string2.
+                    For example, the pattern `x.*y.*z' against the
+                    strings `x-' and `y-z-', if the two strings are
+                    not consecutive in memory.  */
+                 DEBUG_PRINT1 ("Restoring best registers.\n");
+ 
+                 d = match_end;
+                 dend = ((d >= string1 && d <= end1)
+                          ? end_match_1 : end_match_2);
+ 
+                 for (reg = 1; reg < num_regs; reg++)
+                   {
+                     regstart[reg] = best_regstart[reg];
+                     regend[reg] = best_regend[reg];
+                   }
+               }
+           } /* d != end_match_2 */
+ 
+       succeed_label:
+         DEBUG_PRINT1 ("Accepting match.\n");
+ 
+         /* If caller wants register contents data back, do it.  */
+         if (regs && !bufp->no_sub)
+           {
+             /* Have the register data arrays been allocated?  */
+             if (bufp->regs_allocated == REGS_UNALLOCATED)
+               { /* No.  So allocate them with malloc.  We need one
+                    extra element beyond `num_regs' for the `-1' marker
+                    GNU code uses.  */
+                 regs->num_regs = MAX (RE_NREGS, num_regs + 1);
+                 regs->start = TALLOC (regs->num_regs, regoff_t);
+                 regs->end = TALLOC (regs->num_regs, regoff_t);
+                 if (regs->start == NULL || regs->end == NULL)
+                   {
+                     FREE_VARIABLES ();
+                     return -2;
+                   }
+                 bufp->regs_allocated = REGS_REALLOCATE;
+               }
+             else if (bufp->regs_allocated == REGS_REALLOCATE)
+               { /* Yes.  If we need more elements than were already
+                    allocated, reallocate them.  If we need fewer, just
+                    leave it alone.  */
+                 if (regs->num_regs < num_regs + 1)
+                   {
+                     regs->num_regs = num_regs + 1;
+                     RETALLOC (regs->start, regs->num_regs, regoff_t);
+                     RETALLOC (regs->end, regs->num_regs, regoff_t);
+                     if (regs->start == NULL || regs->end == NULL)
+                       {
+                         FREE_VARIABLES ();
+                         return -2;
+                       }
+                   }
+               }
+             else
+               {
+                 /* These braces fend off a "empty body in an else-statement"
+                    warning under GCC when assert expands to nothing.  */
+                 assert (bufp->regs_allocated == REGS_FIXED);
+               }
+ 
+             /* Convert the pointer data in `regstart' and `regend' to
+                indices.  Register zero has to be set differently,
+                since we haven't kept track of any info for it.  */
+             if (regs->num_regs > 0)
+               {
+                 regs->start[0] = pos;
+                 regs->end[0] = POINTER_TO_OFFSET (d);
+               }
+ 
+             /* Go through the first `min (num_regs, regs->num_regs)'
+                registers, since that is all we initialized.  */
+             for (reg = 1; reg < MIN (num_regs, regs->num_regs); reg++)
+               {
+                 if (REG_UNSET (regstart[reg]) || REG_UNSET (regend[reg]))
+                   regs->start[reg] = regs->end[reg] = -1;
+                 else
+                   {
+                     regs->start[reg]
+                       = (regoff_t) POINTER_TO_OFFSET (regstart[reg]);
+                     regs->end[reg]
+                       = (regoff_t) POINTER_TO_OFFSET (regend[reg]);
+                   }
+               }
+ 
+             /* If the regs structure we return has more elements than
+                were in the pattern, set the extra elements to -1.  If
+                we (re)allocated the registers, this is the case,
+                because we always allocate enough to have at least one
+                -1 at the end.  */
+             for (reg = num_regs; reg < regs->num_regs; reg++)
+               regs->start[reg] = regs->end[reg] = -1;
+           } /* regs && !bufp->no_sub */
+ 
+         DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
+                       nfailure_points_pushed, nfailure_points_popped,
+                       nfailure_points_pushed - nfailure_points_popped);
+         DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);
+ 
+         mcnt = POINTER_TO_OFFSET (d) - pos;
+ 
+         DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);
+ 
+         FREE_VARIABLES ();
+         return mcnt;
+       }
+ 
+       /* Otherwise match next pattern command.        */
+       switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
+       {
+       /* Ignore these.  Used to ignore the n of succeed_n's which
+          currently have n == 0.  */
+       case no_op:
+         DEBUG_PRINT1 ("EXECUTING no_op.\n");
+         break;
+ 
+       case succeed:
+         DEBUG_PRINT1 ("EXECUTING succeed.\n");
+         goto succeed_label;
+ 
+       /* Match the next n pattern characters exactly.  The following
+          byte in the pattern defines n, and the n bytes after that
+          are the characters to match.  */
+       case exactn:
+         mcnt = *p++;
+         DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
+ 
+         /* Remember the start point to rollback upon failure.  */
+         dfail = d;
+ 
+ #ifndef emacs
+         /* This is written out as an if-else so we don't waste time
+            testing `translate' inside the loop.  */
+         if (RE_TRANSLATE_P (translate))
+           do
+             {
+               PREFETCH ();
+               if (RE_TRANSLATE (translate, *d) != *p++)
+                 {
+                   d = dfail;
+                   goto fail;
+                 }
+               d++;
+             }
+           while (--mcnt);
+         else
+           do
+             {
+               PREFETCH ();
+               if (*d++ != *p++)
+                 {
+                   d = dfail;
+                   goto fail;
+                 }
+             }
+           while (--mcnt);
+ #else  /* emacs */
+         /* The cost of testing `translate' is comparatively small.  */
+         if (multibyte)
+           do
+             {
+               int pat_charlen, buf_charlen;
+               unsigned int pat_ch, buf_ch;
+ 
+               PREFETCH ();
+               pat_ch = STRING_CHAR_AND_LENGTH (p, pend - p, pat_charlen);
+               buf_ch = STRING_CHAR_AND_LENGTH (d, dend - d, buf_charlen);
+ 
+               if (TRANSLATE (buf_ch) != pat_ch)
+                 {
+                   d = dfail;
+                   goto fail;
+                 }
+ 
+               p += pat_charlen;
+               d += buf_charlen;
+               mcnt -= pat_charlen;
+             }
+           while (mcnt > 0);
+         else
+           do
+             {
+               unsigned int buf_ch;
+ 
+               PREFETCH ();
+               buf_ch = *d++;
+               TRANSLATE_VIA_MULTIBYTE (buf_ch);
+               if (buf_ch != *p++)
+                 {
+                   d = dfail;
+                   goto fail;
+                 }
+             }
+           while (--mcnt);
+ #endif
+         break;
+ 
+ 
+       /* Match any character except possibly a newline or a null.  */
+       case anychar:
+         {
+           int buf_charlen;
+           re_wchar_t buf_ch;
+ 
+           DEBUG_PRINT1 ("EXECUTING anychar.\n");
+ 
+           PREFETCH ();
+           buf_ch = RE_STRING_CHAR_AND_LENGTH (d, dend - d, buf_charlen);
+           buf_ch = TRANSLATE (buf_ch);
+ 
+           if ((!(bufp->syntax & RE_DOT_NEWLINE)
+                && buf_ch == '\n')
+               || ((bufp->syntax & RE_DOT_NOT_NULL)
+                   && buf_ch == '\000'))
+             goto fail;
+ 
+           DEBUG_PRINT2 ("  Matched `%d'.\n", *d);
+           d += buf_charlen;
+         }
+         break;
+ 
+ 
+       case charset:
+       case charset_not:
+         {
+           register unsigned int c;
+           boolean not = (re_opcode_t) *(p - 1) == charset_not;
+           int len;
+ 
+           /* Start of actual range_table, or end of bitmap if there is no
+              range table.  */
+           re_char *range_table;
+ 
+           /* Nonzero if there is a range table.  */
+           int range_table_exists;
+ 
+           /* Number of ranges of range table.  This is not included
+              in the initial byte-length of the command.  */
+           int count = 0;
+ 
+           DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
+ 
+           range_table_exists = CHARSET_RANGE_TABLE_EXISTS_P (&p[-1]);
+ 
+           if (range_table_exists)
+             {
+               range_table = CHARSET_RANGE_TABLE (&p[-1]); /* Past the bitmap. 
 */
+               EXTRACT_NUMBER_AND_INCR (count, range_table);
+             }
+ 
+           PREFETCH ();
+           c = RE_STRING_CHAR_AND_LENGTH (d, dend - d, len);
+           TRANSLATE_VIA_MULTIBYTE (c); /* The character to match.  */
+ 
+           if (! multibyte || IS_REAL_ASCII (c))
+             {                 /* Lookup bitmap.  */
+               /* Cast to `unsigned' instead of `unsigned char' in
+                  case the bit list is a full 32 bytes long.  */
+               if (c < (unsigned) (CHARSET_BITMAP_SIZE (&p[-1]) * BYTEWIDTH)
+                   && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+                 not = !not;
+             }
+ #ifdef emacs
+           else if (range_table_exists)
+             {
+               int class_bits = CHARSET_RANGE_TABLE_BITS (&p[-1]);
+ 
+               if (  (class_bits & BIT_LOWER && ISLOWER (c))
+                   | (class_bits & BIT_MULTIBYTE)
+                   | (class_bits & BIT_PUNCT && ISPUNCT (c))
+                   | (class_bits & BIT_SPACE && ISSPACE (c))
+                   | (class_bits & BIT_UPPER && ISUPPER (c))
+                   | (class_bits & BIT_WORD  && ISWORD (c)))
+                 not = !not;
+               else
+                 CHARSET_LOOKUP_RANGE_TABLE_RAW (not, c, range_table, count);
+             }
+ #endif /* emacs */
+ 
+           if (range_table_exists)
+             p = CHARSET_RANGE_TABLE_END (range_table, count);
+           else
+             p += CHARSET_BITMAP_SIZE (&p[-1]) + 1;
+ 
+           if (!not) goto fail;
+ 
+           d += len;
+           break;
+         }
+ 
+ 
+       /* The beginning of a group is represented by start_memory.
+          The argument is the register number.  The text
+          matched within the group is recorded (in the internal
+          registers data structure) under the register number.  */
+       case start_memory:
+         DEBUG_PRINT2 ("EXECUTING start_memory %d:\n", *p);
+ 
+         /* In case we need to undo this operation (via backtracking).  */
+         PUSH_FAILURE_REG ((unsigned int)*p);
+ 
+         regstart[*p] = d;
+         regend[*p] = NULL;    /* probably unnecessary.  -sm  */
+         DEBUG_PRINT2 ("  regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
+ 
+         /* Move past the register number and inner group count.  */
+         p += 1;
+         break;
+ 
+ 
+       /* The stop_memory opcode represents the end of a group.  Its
+          argument is the same as start_memory's: the register number.  */
+       case stop_memory:
+         DEBUG_PRINT2 ("EXECUTING stop_memory %d:\n", *p);
+ 
+         assert (!REG_UNSET (regstart[*p]));
+         /* Strictly speaking, there should be code such as:
+ 
+               assert (REG_UNSET (regend[*p]));
+               PUSH_FAILURE_REGSTOP ((unsigned int)*p);
+ 
+            But the only info to be pushed is regend[*p] and it is known to
+            be UNSET, so there really isn't anything to push.
+            Not pushing anything, on the other hand deprives us from the
+            guarantee that regend[*p] is UNSET since undoing this operation
+            will not reset its value properly.  This is not important since
+            the value will only be read on the next start_memory or at
+            the very end and both events can only happen if this stop_memory
+            is *not* undone.  */
+ 
+         regend[*p] = d;
+         DEBUG_PRINT2 ("      regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
+ 
+         /* Move past the register number and the inner group count.  */
+         p += 1;
+         break;
+ 
+ 
+       /* \<digit> has been turned into a `duplicate' command which is
+          followed by the numeric value of <digit> as the register number.  */
+       case duplicate:
+         {
+           register re_char *d2, *dend2;
+           int regno = *p++;   /* Get which register to match against.  */
+           DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);
+ 
+           /* Can't back reference a group which we've never matched.  */
+           if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
+             goto fail;
+ 
+           /* Where in input to try to start matching.  */
+           d2 = regstart[regno];
+ 
+           /* Remember the start point to rollback upon failure.  */
+           dfail = d;
+ 
+           /* Where to stop matching; if both the place to start and
+              the place to stop matching are in the same string, then
+              set to the place to stop, otherwise, for now have to use
+              the end of the first string.  */
+ 
+           dend2 = ((FIRST_STRING_P (regstart[regno])
+                     == FIRST_STRING_P (regend[regno]))
+                    ? regend[regno] : end_match_1);
+           for (;;)
+             {
+               /* If necessary, advance to next segment in register
+                  contents.  */
+               while (d2 == dend2)
+                 {
+                   if (dend2 == end_match_2) break;
+                   if (dend2 == regend[regno]) break;
+ 
+                   /* End of string1 => advance to string2. */
+                   d2 = string2;
+                   dend2 = regend[regno];
+                 }
+               /* At end of register contents => success */
+               if (d2 == dend2) break;
+ 
+               /* If necessary, advance to next segment in data.  */
+               PREFETCH ();
+ 
+               /* How many characters left in this segment to match.  */
+               mcnt = dend - d;
+ 
+               /* Want how many consecutive characters we can match in
+                  one shot, so, if necessary, adjust the count.  */
+               if (mcnt > dend2 - d2)
+                 mcnt = dend2 - d2;
+ 
+               /* Compare that many; failure if mismatch, else move
+                  past them.  */
+               if (RE_TRANSLATE_P (translate)
+                   ? bcmp_translate (d, d2, mcnt, translate, multibyte)
+                   : memcmp (d, d2, mcnt))
+                 {
+                   d = dfail;
+                   goto fail;
+                 }
+               d += mcnt, d2 += mcnt;
+             }
+         }
+         break;
+ 
+ 
+       /* begline matches the empty string at the beginning of the string
+          (unless `not_bol' is set in `bufp'), and after newlines.  */
+       case begline:
+         DEBUG_PRINT1 ("EXECUTING begline.\n");
+ 
+         if (AT_STRINGS_BEG (d))
+           {
+             if (!bufp->not_bol) break;
+           }
+         else
+           {
+             unsigned c;
+             GET_CHAR_BEFORE_2 (c, d, string1, end1, string2, end2);
+             if (c == '\n')
+               break;
+           }
+         /* In all other cases, we fail.  */
+         goto fail;
+ 
+ 
+       /* endline is the dual of begline.  */
+       case endline:
+         DEBUG_PRINT1 ("EXECUTING endline.\n");
+ 
+         if (AT_STRINGS_END (d))
+           {
+             if (!bufp->not_eol) break;
+           }
+         else
+           {
+             PREFETCH_NOLIMIT ();
+             if (*d == '\n')
+               break;
+           }
+         goto fail;
+ 
+ 
+       /* Match at the very beginning of the data.  */
+       case begbuf:
+         DEBUG_PRINT1 ("EXECUTING begbuf.\n");
+         if (AT_STRINGS_BEG (d))
+           break;
+         goto fail;
+ 
+ 
+       /* Match at the very end of the data.  */
+       case endbuf:
+         DEBUG_PRINT1 ("EXECUTING endbuf.\n");
+         if (AT_STRINGS_END (d))
+           break;
+         goto fail;
+ 
+ 
+       /* on_failure_keep_string_jump is used to optimize `.*\n'.  It
+          pushes NULL as the value for the string on the stack.  Then
+          `POP_FAILURE_POINT' will keep the current value for the
+          string, instead of restoring it.  To see why, consider
+          matching `foo\nbar' against `.*\n'.  The .* matches the foo;
+          then the . fails against the \n.  But the next thing we want
+          to do is match the \n against the \n; if we restored the
+          string value, we would be back at the foo.
+ 
+          Because this is used only in specific cases, we don't need to
+          check all the things that `on_failure_jump' does, to make
+          sure the right things get saved on the stack.  Hence we don't
+          share its code.  The only reason to push anything on the
+          stack at all is that otherwise we would have to change
+          `anychar's code to do something besides goto fail in this
+          case; that seems worse than this.  */
+       case on_failure_keep_string_jump:
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);
+         DEBUG_PRINT3 ("EXECUTING on_failure_keep_string_jump %d (to %p):\n",
+                       mcnt, p + mcnt);
+ 
+         PUSH_FAILURE_POINT (p - 3, NULL);
+         break;
+ 
+         /* A nasty loop is introduced by the non-greedy *? and +?.
+            With such loops, the stack only ever contains one failure point
+            at a time, so that a plain on_failure_jump_loop kind of
+            cycle detection cannot work.  Worse yet, such a detection
+            can not only fail to detect a cycle, but it can also wrongly
+            detect a cycle (between different instantiations of the same
+            loop).
+            So the method used for those nasty loops is a little different:
+            We use a special cycle-detection-stack-frame which is pushed
+            when the on_failure_jump_nastyloop failure-point is *popped*.
+            This special frame thus marks the beginning of one iteration
+            through the loop and we can hence easily check right here
+            whether something matched between the beginning and the end of
+            the loop.  */
+       case on_failure_jump_nastyloop:
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);
+         DEBUG_PRINT3 ("EXECUTING on_failure_jump_nastyloop %d (to %p):\n",
+                       mcnt, p + mcnt);
+ 
+         assert ((re_opcode_t)p[-4] == no_op);
+         {
+           int cycle = 0;
+           CHECK_INFINITE_LOOP (p - 4, d);
+           if (!cycle)
+             /* If there's a cycle, just continue without pushing
+                this failure point.  The failure point is the "try again"
+                option, which shouldn't be tried.
+                We want (x?)*?y\1z to match both xxyz and xxyxz.  */
+             PUSH_FAILURE_POINT (p - 3, d);
+         }
+         break;
+ 
+         /* Simple loop detecting on_failure_jump:  just check on the
+            failure stack if the same spot was already hit earlier.  */
+       case on_failure_jump_loop:
+       on_failure:
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);
+         DEBUG_PRINT3 ("EXECUTING on_failure_jump_loop %d (to %p):\n",
+                       mcnt, p + mcnt);
+         {
+           int cycle = 0;
+           CHECK_INFINITE_LOOP (p - 3, d);
+           if (cycle)
+             /* If there's a cycle, get out of the loop, as if the matching
+                had failed.  We used to just `goto fail' here, but that was
+                aborting the search a bit too early: we want to keep the
+                empty-loop-match and keep matching after the loop.
+                We want (x?)*y\1z to match both xxyz and xxyxz.  */
+             p += mcnt;
+           else
+             PUSH_FAILURE_POINT (p - 3, d);
+         }
+         break;
+ 
+ 
+       /* Uses of on_failure_jump:
+ 
+          Each alternative starts with an on_failure_jump that points
+          to the beginning of the next alternative.  Each alternative
+          except the last ends with a jump that in effect jumps past
+          the rest of the alternatives.  (They really jump to the
+          ending jump of the following alternative, because tensioning
+          these jumps is a hassle.)
+ 
+          Repeats start with an on_failure_jump that points past both
+          the repetition text and either the following jump or
+          pop_failure_jump back to this on_failure_jump.  */
+       case on_failure_jump:
+         IMMEDIATE_QUIT_CHECK;
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);
+         DEBUG_PRINT3 ("EXECUTING on_failure_jump %d (to %p):\n",
+                       mcnt, p + mcnt);
+ 
+         PUSH_FAILURE_POINT (p -3, d);
+         break;
+ 
+       /* This operation is used for greedy *.
+          Compare the beginning of the repeat with what in the
+          pattern follows its end. If we can establish that there
+          is nothing that they would both match, i.e., that we
+          would have to backtrack because of (as in, e.g., `a*a')
+          then we can use a non-backtracking loop based on
+          on_failure_keep_string_jump instead of on_failure_jump.  */
+       case on_failure_jump_smart:
+         IMMEDIATE_QUIT_CHECK;
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);
+         DEBUG_PRINT3 ("EXECUTING on_failure_jump_smart %d (to %p).\n",
+                       mcnt, p + mcnt);
+         {
+           re_char *p1 = p; /* Next operation.  */
+           /* Here, we discard `const', making re_match non-reentrant.  */
+           unsigned char *p2 = (unsigned char*) p + mcnt; /* Jump dest.  */
+           unsigned char *p3 = (unsigned char*) p - 3; /* opcode location.  */
+ 
+           p -= 3;             /* Reset so that we will re-execute the
+                                  instruction once it's been changed. */
+ 
+           EXTRACT_NUMBER (mcnt, p2 - 2);
+ 
+           /* Ensure this is a indeed the trivial kind of loop
+              we are expecting.  */
+           assert (skip_one_char (p1) == p2 - 3);
+           assert ((re_opcode_t) p2[-3] == jump && p2 + mcnt == p);
+           DEBUG_STATEMENT (debug += 2);
+           if (mutually_exclusive_p (bufp, p1, p2))
+             {
+               /* Use a fast `on_failure_keep_string_jump' loop.  */
+               DEBUG_PRINT1 ("  smart exclusive => fast loop.\n");
+               *p3 = (unsigned char) on_failure_keep_string_jump;
+               STORE_NUMBER (p2 - 2, mcnt + 3);
+             }
+           else
+             {
+               /* Default to a safe `on_failure_jump' loop.  */
+               DEBUG_PRINT1 ("  smart default => slow loop.\n");
+               *p3 = (unsigned char) on_failure_jump;
+             }
+           DEBUG_STATEMENT (debug -= 2);
+         }
+         break;
+ 
+       /* Unconditionally jump (without popping any failure points).  */
+       case jump:
+       unconditional_jump:
+         IMMEDIATE_QUIT_CHECK;
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);    /* Get the amount to jump.  */
+         DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
+         p += mcnt;                            /* Do the jump.  */
+         DEBUG_PRINT2 ("(to %p).\n", p);
+         break;
+ 
+ 
+       /* Have to succeed matching what follows at least n times.
+          After that, handle like `on_failure_jump'.  */
+       case succeed_n:
+         /* Signedness doesn't matter since we only compare MCNT to 0.  */
+         EXTRACT_NUMBER (mcnt, p + 2);
+         DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
+ 
+         /* Originally, mcnt is how many times we HAVE to succeed.  */
+         if (mcnt != 0)
+           {
+             /* Here, we discard `const', making re_match non-reentrant.  */
+             unsigned char *p2 = (unsigned char*) p + 2; /* counter loc.  */
+             mcnt--;
+             p += 4;
+             PUSH_NUMBER (p2, mcnt);
+           }
+         else
+           /* The two bytes encoding mcnt == 0 are two no_op opcodes.  */
+           goto on_failure;
+         break;
+ 
+       case jump_n:
+         /* Signedness doesn't matter since we only compare MCNT to 0.  */
+         EXTRACT_NUMBER (mcnt, p + 2);
+         DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
+ 
+         /* Originally, this is how many times we CAN jump.  */
+         if (mcnt != 0)
+           {
+              /* Here, we discard `const', making re_match non-reentrant.  */
+             unsigned char *p2 = (unsigned char*) p + 2; /* counter loc.  */
+             mcnt--;
+             PUSH_NUMBER (p2, mcnt);
+             goto unconditional_jump;
+           }
+         /* If don't have to jump any more, skip over the rest of command.  */
+         else
+           p += 4;
+         break;
+ 
+       case set_number_at:
+         {
+           unsigned char *p2;  /* Location of the counter.  */
+           DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
+ 
+           EXTRACT_NUMBER_AND_INCR (mcnt, p);
+           /* Here, we discard `const', making re_match non-reentrant.  */
+           p2 = (unsigned char*) p + mcnt;
+           /* Signedness doesn't matter since we only copy MCNT's bits .  */
+           EXTRACT_NUMBER_AND_INCR (mcnt, p);
+           DEBUG_PRINT3 ("  Setting %p to %d.\n", p2, mcnt);
+           PUSH_NUMBER (p2, mcnt);
+           break;
+         }
+ 
+       case wordbound:
+       case notwordbound:
+         not = (re_opcode_t) *(p - 1) == notwordbound;
+         DEBUG_PRINT2 ("EXECUTING %swordbound.\n", not?"not":"");
+ 
+         /* We SUCCEED (or FAIL) in one of the following cases: */
+ 
+         /* Case 1: D is at the beginning or the end of string.  */
+         if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
+           not = !not;
+         else
+           {
+             /* C1 is the character before D, S1 is the syntax of C1, C2
+                is the character at D, and S2 is the syntax of C2.  */
+             re_wchar_t c1, c2;
+             int s1, s2;
+             int dummy;
+ #ifdef emacs
+             int offset = PTR_TO_OFFSET (d - 1);
+             int charpos = SYNTAX_TABLE_BYTE_TO_CHAR (offset);
+             UPDATE_SYNTAX_TABLE (charpos);
+ #endif
+             GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+             s1 = SYNTAX (c1);
+ #ifdef emacs
+             UPDATE_SYNTAX_TABLE_FORWARD (charpos + 1);
+ #endif
+             PREFETCH_NOLIMIT ();
+             GET_CHAR_AFTER (c2, d, dummy);
+             s2 = SYNTAX (c2);
+ 
+             if (/* Case 2: Only one of S1 and S2 is Sword.  */
+                 ((s1 == Sword) != (s2 == Sword))
+                 /* Case 3: Both of S1 and S2 are Sword, and macro
+                    WORD_BOUNDARY_P (C1, C2) returns nonzero.  */
+                 || ((s1 == Sword) && WORD_BOUNDARY_P (c1, c2)))
+               not = !not;
+           }
+         if (not)
+           break;
+         else
+           goto fail;
+ 
+       case wordbeg:
+         DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
+ 
+         /* We FAIL in one of the following cases: */
+ 
+         /* Case 1: D is at the end of string.  */
+         if (AT_STRINGS_END (d))
+           goto fail;
+         else
+           {
+             /* C1 is the character before D, S1 is the syntax of C1, C2
+                is the character at D, and S2 is the syntax of C2.  */
+             re_wchar_t c1, c2;
+             int s1, s2;
+             int dummy;
+ #ifdef emacs
+             int offset = PTR_TO_OFFSET (d);
+             int charpos = SYNTAX_TABLE_BYTE_TO_CHAR (offset);
+             UPDATE_SYNTAX_TABLE (charpos);
+ #endif
+             PREFETCH ();
+             GET_CHAR_AFTER (c2, d, dummy);
+             s2 = SYNTAX (c2);
+ 
+             /* Case 2: S2 is not Sword. */
+             if (s2 != Sword)
+               goto fail;
+ 
+             /* Case 3: D is not at the beginning of string ... */
+             if (!AT_STRINGS_BEG (d))
+               {
+                 GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+ #ifdef emacs
+                 UPDATE_SYNTAX_TABLE_BACKWARD (charpos - 1);
+ #endif
+                 s1 = SYNTAX (c1);
+ 
+                 /* ... and S1 is Sword, and WORD_BOUNDARY_P (C1, C2)
+                    returns 0.  */
+                 if ((s1 == Sword) && !WORD_BOUNDARY_P (c1, c2))
+                   goto fail;
+               }
+           }
+         break;
+ 
+       case wordend:
+         DEBUG_PRINT1 ("EXECUTING wordend.\n");
+ 
+         /* We FAIL in one of the following cases: */
+ 
+         /* Case 1: D is at the beginning of string.  */
+         if (AT_STRINGS_BEG (d))
+           goto fail;
+         else
+           {
+             /* C1 is the character before D, S1 is the syntax of C1, C2
+                is the character at D, and S2 is the syntax of C2.  */
+             re_wchar_t c1, c2;
+             int s1, s2;
+             int dummy;
+ #ifdef emacs
+             int offset = PTR_TO_OFFSET (d) - 1;
+             int charpos = SYNTAX_TABLE_BYTE_TO_CHAR (offset);
+             UPDATE_SYNTAX_TABLE (charpos);
+ #endif
+             GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+             s1 = SYNTAX (c1);
+ 
+             /* Case 2: S1 is not Sword.  */
+             if (s1 != Sword)
+               goto fail;
+ 
+             /* Case 3: D is not at the end of string ... */
+             if (!AT_STRINGS_END (d))
+               {
+                 PREFETCH_NOLIMIT ();
+                 GET_CHAR_AFTER (c2, d, dummy);
+ #ifdef emacs
+                 UPDATE_SYNTAX_TABLE_FORWARD (charpos);
+ #endif
+                 s2 = SYNTAX (c2);
+ 
+                 /* ... and S2 is Sword, and WORD_BOUNDARY_P (C1, C2)
+                    returns 0.  */
+                 if ((s2 == Sword) && !WORD_BOUNDARY_P (c1, c2))
+         goto fail;
+               }
+           }
+         break;
+ 
+       case syntaxspec:
+       case notsyntaxspec:
+         not = (re_opcode_t) *(p - 1) == notsyntaxspec;
+         mcnt = *p++;
+         DEBUG_PRINT3 ("EXECUTING %ssyntaxspec %d.\n", not?"not":"", mcnt);
+         PREFETCH ();
+ #ifdef emacs
+         {
+           int offset = PTR_TO_OFFSET (d);
+           int pos1 = SYNTAX_TABLE_BYTE_TO_CHAR (offset);
+           UPDATE_SYNTAX_TABLE (pos1);
+         }
+ #endif
+         {
+           int len;
+           re_wchar_t c;
+ 
+           GET_CHAR_AFTER (c, d, len);
+           if ((SYNTAX (c) != (enum syntaxcode) mcnt) ^ not)
+             goto fail;
+           d += len;
+         }
+         break;
+ 
+ #ifdef emacs
+       case before_dot:
+         DEBUG_PRINT1 ("EXECUTING before_dot.\n");
+         if (PTR_BYTE_POS (d) >= PT_BYTE)
+           goto fail;
+         break;
+ 
+       case at_dot:
+         DEBUG_PRINT1 ("EXECUTING at_dot.\n");
+         if (PTR_BYTE_POS (d) != PT_BYTE)
+           goto fail;
+         break;
+ 
+       case after_dot:
+         DEBUG_PRINT1 ("EXECUTING after_dot.\n");
+         if (PTR_BYTE_POS (d) <= PT_BYTE)
+           goto fail;
+         break;
+ 
+       case categoryspec:
+       case notcategoryspec:
+         not = (re_opcode_t) *(p - 1) == notcategoryspec;
+         mcnt = *p++;
+         DEBUG_PRINT3 ("EXECUTING %scategoryspec %d.\n", not?"not":"", mcnt);
+         PREFETCH ();
+         {
+           int len;
+           re_wchar_t c;
+ 
+           GET_CHAR_AFTER (c, d, len);
+           if ((!CHAR_HAS_CATEGORY (c, mcnt)) ^ not)
+             goto fail;
+           d += len;
+         }
+         break;
+ 
+ #endif /* emacs */
+ 
+       default:
+         abort ();
+       }
+       continue;  /* Successfully executed one pattern command; keep going.  */
+ 
+ 
+     /* We goto here if a matching operation fails. */
+     fail:
+       IMMEDIATE_QUIT_CHECK;
+       if (!FAIL_STACK_EMPTY ())
+       {
+         re_char *str, *pat;
+         /* A restart point is known.  Restore to that state.  */
+         DEBUG_PRINT1 ("\nFAIL:\n");
+         POP_FAILURE_POINT (str, pat);
+         switch (SWITCH_ENUM_CAST ((re_opcode_t) *pat++))
+           {
+           case on_failure_keep_string_jump:
+             assert (str == NULL);
+             goto continue_failure_jump;
+ 
+           case on_failure_jump_nastyloop:
+             assert ((re_opcode_t)pat[-2] == no_op);
+             PUSH_FAILURE_POINT (pat - 2, str);
+             /* Fallthrough */
+ 
+           case on_failure_jump_loop:
+           case on_failure_jump:
+           case succeed_n:
+             d = str;
+           continue_failure_jump:
+             EXTRACT_NUMBER_AND_INCR (mcnt, pat);
+             p = pat + mcnt;
+             break;
+ 
+           case no_op:
+             /* A special frame used for nastyloops. */
+             goto fail;
+ 
+           default:
+             abort();
+           }
+ 
+         assert (p >= bufp->buffer && p <= pend);
+ 
+         if (d >= string1 && d <= end1)
+           dend = end_match_1;
+       }
+       else
+       break;   /* Matching at this starting point really fails.  */
+     } /* for (;;) */
+ 
+   if (best_regs_set)
+     goto restore_best_regs;
+ 
+   FREE_VARIABLES ();
+ 
+   return -1;                          /* Failure to match.  */
+ } /* re_match_2 */
+ 
+ /* Subroutine definitions for re_match_2.  */
+ 
+ /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
+    bytes; nonzero otherwise.  */
+ 
+ static int
+ bcmp_translate (s1, s2, len, translate, multibyte)
+      re_char *s1, *s2;
+      register int len;
+      RE_TRANSLATE_TYPE translate;
+      const int multibyte;
+ {
+   register re_char *p1 = s1, *p2 = s2;
+   re_char *p1_end = s1 + len;
+   re_char *p2_end = s2 + len;
+ 
+   /* FIXME: Checking both p1 and p2 presumes that the two strings might have
+      different lengths, but relying on a single `len' would break this. -sm  
*/
+   while (p1 < p1_end && p2 < p2_end)
+     {
+       int p1_charlen, p2_charlen;
+       re_wchar_t p1_ch, p2_ch;
+ 
+       GET_CHAR_AFTER (p1_ch, p1, p1_charlen);
+       GET_CHAR_AFTER (p2_ch, p2, p2_charlen);
+ 
+       if (RE_TRANSLATE (translate, p1_ch)
+         != RE_TRANSLATE (translate, p2_ch))
+       return 1;
+ 
+       p1 += p1_charlen, p2 += p2_charlen;
+     }
+ 
+   if (p1 != p1_end || p2 != p2_end)
+     return 1;
+ 
+   return 0;
+ }
+ 
+ /* Entry points for GNU code.  */
+ 
+ /* re_compile_pattern is the GNU regular expression compiler: it
+    compiles PATTERN (of length SIZE) and puts the result in BUFP.
+    Returns 0 if the pattern was valid, otherwise an error string.
+ 
+    Assumes the `allocated' (and perhaps `buffer') and `translate' fields
+    are set in BUFP on entry.
+ 
+    We call regex_compile to do the actual compilation.  */
+ 
+ const char *
+ re_compile_pattern (pattern, length, bufp)
+      const char *pattern;
+      size_t length;
+      struct re_pattern_buffer *bufp;
+ {
+   reg_errcode_t ret;
+ 
+   /* GNU code is written to assume at least RE_NREGS registers will be set
+      (and at least one extra will be -1).  */
+   bufp->regs_allocated = REGS_UNALLOCATED;
+ 
+   /* And GNU code determines whether or not to get register information
+      by passing null for the REGS argument to re_match, etc., not by
+      setting no_sub.  */
+   bufp->no_sub = 0;
+ 
+   ret = regex_compile ((re_char*) pattern, length, re_syntax_options, bufp);
+ 
+   if (!ret)
+     return NULL;
+   return gettext (re_error_msgid[(int) ret]);
+ }
+ WEAK_ALIAS (__re_compile_pattern, re_compile_pattern)
+ 
+ /* Entry points compatible with 4.2 BSD regex library.  We don't define
+    them unless specifically requested.  */
+ 
+ #if defined _REGEX_RE_COMP || defined _LIBC
+ 
+ /* BSD has one and only one pattern buffer.  */
+ static struct re_pattern_buffer re_comp_buf;
+ 
+ char *
+ # ifdef _LIBC
+ /* Make these definitions weak in libc, so POSIX programs can redefine
+    these names if they don't use our functions, and still use
+    regcomp/regexec below without link errors.  */
+ weak_function
+ # endif
+ re_comp (s)
+     const char *s;
+ {
+   reg_errcode_t ret;
+ 
+   if (!s)
+     {
+       if (!re_comp_buf.buffer)
+       /* Yes, we're discarding `const' here if !HAVE_LIBINTL.  */
+       return (char *) gettext ("No previous regular expression");
+       return 0;
+     }
+ 
+   if (!re_comp_buf.buffer)
+     {
+       re_comp_buf.buffer = (unsigned char *) malloc (200);
+       if (re_comp_buf.buffer == NULL)
+       /* Yes, we're discarding `const' here if !HAVE_LIBINTL.  */
+       return (char *) gettext (re_error_msgid[(int) REG_ESPACE]);
+       re_comp_buf.allocated = 200;
+ 
+       re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
+       if (re_comp_buf.fastmap == NULL)
+       /* Yes, we're discarding `const' here if !HAVE_LIBINTL.  */
+       return (char *) gettext (re_error_msgid[(int) REG_ESPACE]);
+     }
+ 
+   /* Since `re_exec' always passes NULL for the `regs' argument, we
+      don't need to initialize the pattern buffer fields which affect it.  */
+ 
+   ret = regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
+ 
+   if (!ret)
+     return NULL;
+ 
+   /* Yes, we're discarding `const' here if !HAVE_LIBINTL.  */
+   return (char *) gettext (re_error_msgid[(int) ret]);
+ }
+ 
+ 
+ int
+ # ifdef _LIBC
+ weak_function
+ # endif
+ re_exec (s)
+     const char *s;
+ {
+   const int len = strlen (s);
+   return
+     0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
+ }
+ #endif /* _REGEX_RE_COMP */
+ 
+ /* POSIX.2 functions.  Don't define these for Emacs.  */
+ 
+ #ifndef emacs
+ 
+ /* regcomp takes a regular expression as a string and compiles it.
+ 
+    PREG is a regex_t *.  We do not expect any fields to be initialized,
+    since POSIX says we shouldn't.  Thus, we set
+ 
+      `buffer' to the compiled pattern;
+      `used' to the length of the compiled pattern;
+      `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
+        REG_EXTENDED bit in CFLAGS is set; otherwise, to
+        RE_SYNTAX_POSIX_BASIC;
+      `fastmap' to an allocated space for the fastmap;
+      `fastmap_accurate' to zero;
+      `re_nsub' to the number of subexpressions in PATTERN.
+ 
+    PATTERN is the address of the pattern string.
+ 
+    CFLAGS is a series of bits which affect compilation.
+ 
+      If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
+      use POSIX basic syntax.
+ 
+      If REG_NEWLINE is set, then . and [^...] don't match newline.
+      Also, regexec will try a match beginning after every newline.
+ 
+      If REG_ICASE is set, then we considers upper- and lowercase
+      versions of letters to be equivalent when matching.
+ 
+      If REG_NOSUB is set, then when PREG is passed to regexec, that
+      routine will report only success or failure, and nothing about the
+      registers.
+ 
+    It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
+    the return codes and their meanings.)  */
+ 
+ int
+ regcomp (preg, pattern, cflags)
+     regex_t *__restrict preg;
+     const char *__restrict pattern;
+     int cflags;
+ {
+   reg_errcode_t ret;
+   reg_syntax_t syntax
+     = (cflags & REG_EXTENDED) ?
+       RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC;
+ 
+   /* regex_compile will allocate the space for the compiled pattern.  */
+   preg->buffer = 0;
+   preg->allocated = 0;
+   preg->used = 0;
+ 
+   /* Try to allocate space for the fastmap.  */
+   preg->fastmap = (char *) malloc (1 << BYTEWIDTH);
+ 
+   if (cflags & REG_ICASE)
+     {
+       unsigned i;
+ 
+       preg->translate
+       = (RE_TRANSLATE_TYPE) malloc (CHAR_SET_SIZE
+                                     * sizeof (*(RE_TRANSLATE_TYPE)0));
+       if (preg->translate == NULL)
+       return (int) REG_ESPACE;
+ 
+       /* Map uppercase characters to corresponding lowercase ones.  */
+       for (i = 0; i < CHAR_SET_SIZE; i++)
+       preg->translate[i] = ISUPPER (i) ? TOLOWER (i) : i;
+     }
+   else
+     preg->translate = NULL;
+ 
+   /* If REG_NEWLINE is set, newlines are treated differently.  */
+   if (cflags & REG_NEWLINE)
+     { /* REG_NEWLINE implies neither . nor [^...] match newline.  */
+       syntax &= ~RE_DOT_NEWLINE;
+       syntax |= RE_HAT_LISTS_NOT_NEWLINE;
+     }
+   else
+     syntax |= RE_NO_NEWLINE_ANCHOR;
+ 
+   preg->no_sub = !!(cflags & REG_NOSUB);
+ 
+   /* POSIX says a null character in the pattern terminates it, so we
+      can use strlen here in compiling the pattern.  */
+   ret = regex_compile ((re_char*) pattern, strlen (pattern), syntax, preg);
+ 
+   /* POSIX doesn't distinguish between an unmatched open-group and an
+      unmatched close-group: both are REG_EPAREN.  */
+   if (ret == REG_ERPAREN)
+     ret = REG_EPAREN;
+ 
+   if (ret == REG_NOERROR && preg->fastmap)
+     { /* Compute the fastmap now, since regexec cannot modify the pattern
+        buffer.  */
+       re_compile_fastmap (preg);
+       if (preg->can_be_null)
+       { /* The fastmap can't be used anyway.  */
+         free (preg->fastmap);
+         preg->fastmap = NULL;
+       }
+     }
+   return (int) ret;
+ }
+ WEAK_ALIAS (__regcomp, regcomp)
+ 
+ 
+ /* regexec searches for a given pattern, specified by PREG, in the
+    string STRING.
+ 
+    If NMATCH is zero or REG_NOSUB was set in the cflags argument to
+    `regcomp', we ignore PMATCH.  Otherwise, we assume PMATCH has at
+    least NMATCH elements, and we set them to the offsets of the
+    corresponding matched substrings.
+ 
+    EFLAGS specifies `execution flags' which affect matching: if
+    REG_NOTBOL is set, then ^ does not match at the beginning of the
+    string; if REG_NOTEOL is set, then $ does not match at the end.
+ 
+    We return 0 if we find a match and REG_NOMATCH if not.  */
+ 
+ int
+ regexec (preg, string, nmatch, pmatch, eflags)
+     const regex_t *__restrict preg;
+     const char *__restrict string;
+     size_t nmatch;
+     regmatch_t pmatch[__restrict_arr];
+     int eflags;
+ {
+   int ret;
+   struct re_registers regs;
+   regex_t private_preg;
+   int len = strlen (string);
+   boolean want_reg_info = !preg->no_sub && nmatch > 0 && pmatch;
+ 
+   private_preg = *preg;
+ 
+   private_preg.not_bol = !!(eflags & REG_NOTBOL);
+   private_preg.not_eol = !!(eflags & REG_NOTEOL);
+ 
+   /* The user has told us exactly how many registers to return
+      information about, via `nmatch'.  We have to pass that on to the
+      matching routines.  */
+   private_preg.regs_allocated = REGS_FIXED;
+ 
+   if (want_reg_info)
+     {
+       regs.num_regs = nmatch;
+       regs.start = TALLOC (nmatch * 2, regoff_t);
+       if (regs.start == NULL)
+       return (int) REG_NOMATCH;
+       regs.end = regs.start + nmatch;
+     }
+ 
+   /* Instead of using not_eol to implement REG_NOTEOL, we could simply
+      pass (&private_preg, string, len + 1, 0, len, ...) pretending the string
+      was a little bit longer but still only matching the real part.
+      This works because the `endline' will check for a '\n' and will find a
+      '\0', correctly deciding that this is not the end of a line.
+      But it doesn't work out so nicely for REG_NOTBOL, since we don't have
+      a convenient '\0' there.  For all we know, the string could be preceded
+      by '\n' which would throw things off.  */
+ 
+   /* Perform the searching operation.  */
+   ret = re_search (&private_preg, string, len,
+                  /* start: */ 0, /* range: */ len,
+                  want_reg_info ? &regs : (struct re_registers *) 0);
+ 
+   /* Copy the register information to the POSIX structure.  */
+   if (want_reg_info)
+     {
+       if (ret >= 0)
+       {
+         unsigned r;
+ 
+         for (r = 0; r < nmatch; r++)
+           {
+             pmatch[r].rm_so = regs.start[r];
+             pmatch[r].rm_eo = regs.end[r];
+           }
+       }
+ 
+       /* If we needed the temporary register info, free the space now.  */
+       free (regs.start);
+     }
+ 
+   /* We want zero return to mean success, unlike `re_search'.  */
+   return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH;
+ }
+ WEAK_ALIAS (__regexec, regexec)
+ 
+ 
+ /* Returns a message corresponding to an error code, ERRCODE, returned
+    from either regcomp or regexec.   We don't use PREG here.  */
+ 
+ size_t
+ regerror (errcode, preg, errbuf, errbuf_size)
+     int errcode;
+     const regex_t *preg;
+     char *errbuf;
+     size_t errbuf_size;
+ {
+   const char *msg;
+   size_t msg_size;
+ 
+   if (errcode < 0
+       || errcode >= (sizeof (re_error_msgid) / sizeof (re_error_msgid[0])))
+     /* Only error codes returned by the rest of the code should be passed
+        to this routine.  If we are given anything else, or if other regex
+        code generates an invalid error code, then the program has a bug.
+        Dump core so we can fix it.  */
+     abort ();
+ 
+   msg = gettext (re_error_msgid[errcode]);
+ 
+   msg_size = strlen (msg) + 1; /* Includes the null.  */
+ 
+   if (errbuf_size != 0)
+     {
+       if (msg_size > errbuf_size)
+       {
+         strncpy (errbuf, msg, errbuf_size - 1);
+         errbuf[errbuf_size - 1] = 0;
+       }
+       else
+       strcpy (errbuf, msg);
+     }
+ 
+   return msg_size;
+ }
+ WEAK_ALIAS (__regerror, regerror)
+ 
+ 
+ /* Free dynamically allocated space used by PREG.  */
+ 
+ void
+ regfree (preg)
+     regex_t *preg;
+ {
+   if (preg->buffer != NULL)
+     free (preg->buffer);
+   preg->buffer = NULL;
+ 
+   preg->allocated = 0;
+   preg->used = 0;
+ 
+   if (preg->fastmap != NULL)
+     free (preg->fastmap);
+   preg->fastmap = NULL;
+   preg->fastmap_accurate = 0;
+ 
+   if (preg->translate != NULL)
+     free (preg->translate);
+   preg->translate = NULL;
+ }
+ WEAK_ALIAS (__regfree, regfree)
+ 
+ #endif /* not emacs  */




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