Makefile.in: Add support for regex code.
authorJeff Johnston <jjohnstn@redhat.com>
Wed, 11 Jul 2001 00:11:12 +0000 (00:11 +0000)
committerDJ Delorie <dj@gcc.gnu.org>
Wed, 11 Jul 2001 00:11:12 +0000 (20:11 -0400)
* Makefile.in: Add support for regex code.
* regex.c: New file.

From-SVN: r43914

libiberty/ChangeLog
libiberty/Makefile.in
libiberty/regex.c [new file with mode: 0644]

index b0f8886ba1e53001f6bc15487cb6ef4ddec9f399..9df787b63eb90ec9140de76f87a18e661cee27cb 100644 (file)
@@ -1,3 +1,8 @@
+2001-07-10  Jeff Johnston  <jjohnstn@redhat.com>
+
+       * Makefile.in: Add support for regex code.
+       * regex.c: New file.
+
 2001-07-05  Mark Klein  <mklein@dis.com>
 
        * Makefile.in: Add ffs.c dependency.
index 66aa510137c61271a082015818d6190e6372af10..fd2f41581187f80dc134b954c5c94f8cc1ed4d3c 100644 (file)
@@ -127,7 +127,8 @@ CFILES = asprintf.c alloca.c argv.c atexit.c basename.c bcmp.c bcopy.c            \
        floatformat.c hashtab.c hex.c index.c insque.c lbasename.c            \
        md5.c make-temp-file.c memchr.c                                       \
        memcmp.c memcpy.c memmove.c memset.c mkstemps.c objalloc.c obstack.c  \
-       partition.c pexecute.c putenv.c random.c rename.c rindex.c setenv.c   \
+       partition.c pexecute.c putenv.c random.c                              \
+       regex.c rename.c rindex.c setenv.c                                    \
        sigsetmask.c safe-ctype.c sort.c spaces.c splay-tree.c strcasecmp.c   \
        strncasecmp.c strchr.c strdup.c strerror.c strncmp.c strrchr.c        \
        strsignal.c strstr.c strtod.c strtol.c strtoul.c tmpnam.c vasprintf.c \
@@ -139,7 +140,7 @@ REQUIRED_OFILES = argv.o alloca.o choose-temp.o concat.o cplus-dem.o          \
        cp-demangle.o dyn-string.o fdmatch.o fnmatch.o getopt.o getopt1.o     \
        getpwd.o getruntime.o hashtab.o hex.o floatformat.o lbasename.o       \
         md5.o make-temp-file.o objalloc.o                                    \
-       obstack.o partition.o pexecute.o safe-ctype.o sort.o spaces.o         \
+       obstack.o partition.o pexecute.o regex.o safe-ctype.o sort.o spaces.o \
        splay-tree.o strerror.o strsignal.o xatexit.o xexit.o xmalloc.o       \
        xmemdup.o xstrdup.o xstrerror.o ternary.o
 
@@ -281,6 +282,7 @@ objalloc.o: config.h $(INCDIR)/objalloc.h
 obstack.o: config.h $(INCDIR)/obstack.h
 partition.o: config.h $(INCDIR)/partition.h
 pexecute.o: config.h $(INCDIR)/libiberty.h
+regex.o: $(INCDIR)/xregex.h $(INCDIR)/xregex2.h
 rename.o: config.h
 setenv.o: config.h
 sort.o: config.h $(INCDIR)/sort.h $(INCDIR)/ansidecl.h
diff --git a/libiberty/regex.c b/libiberty/regex.c
new file mode 100644 (file)
index 0000000..642dc05
--- /dev/null
@@ -0,0 +1,8245 @@
+/* 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) 1993-1999, 2000, 2001 Free Software Foundation, Inc.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* This file has been modified for usage in libiberty.  It includes "xregex.h"
+   instead of <regex.h>.  The "xregex.h" header file renames all external
+   routines with an "x" prefix so they do not collide with the native regex
+   routines or with other components regex routines. */
+#if defined _AIX && !defined REGEX_MALLOC
+  #pragma alloca
+#endif
+
+#undef _GNU_SOURCE
+#define _GNU_SOURCE
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#ifndef PARAMS
+# if defined __GNUC__ || (defined __STDC__ && __STDC__)
+#  define PARAMS(args) args
+# else
+#  define PARAMS(args) ()
+# endif  /* GCC.  */
+#endif  /* Not PARAMS.  */
+
+#ifndef INSIDE_RECURSION
+
+# 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
+
+# define WIDE_CHAR_SUPPORT (HAVE_WCTYPE_H && HAVE_WCHAR_H && HAVE_BTOWC)
+
+/* For platform which support the ISO C amendement 1 functionality we
+   support user defined character classes.  */
+# if defined _LIBC || 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)
+
+#  define btowc __btowc
+
+/* We are also using some library internals.  */
+#  include <locale/localeinfo.h>
+#  include <locale/elem-hash.h>
+#  include <langinfo.h>
+#  include <locale/coll-lookup.h>
+# endif
+
+/* This is for other GNU distributions with internationalized messages.  */
+# if HAVE_LIBINTL_H || defined _LIBC
+#  include <libintl.h>
+#  ifdef _LIBC
+#   undef gettext
+#   define gettext(msgid) __dcgettext ("libc", msgid, LC_MESSAGES)
+#  endif
+# 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"
+#  include "syntax.h"
+
+# 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 a bcopy and a 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.  */
+
+/* This must be nonzero for the wordchar and notwordchar pattern
+   commands in re_match_2.  */
+#  ifndef Sword
+#   define Sword 1
+#  endif
+
+#  ifdef SWITCH_ENUM_BUG
+#   define SWITCH_ENUM_CAST(x) ((int)(x))
+#  else
+#   define SWITCH_ENUM_CAST(x) (x)
+#  endif
+
+# endif /* not emacs */
+
+# if defined _LIBC || HAVE_LIMITS_H
+#  include <limits.h>
+# endif
+
+# ifndef MB_LEN_MAX
+#  define MB_LEN_MAX 1
+# endif
+\f
+/* Get the interface, including the syntax bits.  */
+# include "xregex.h"  /* change for libiberty */
+
+/* isalpha etc. are used for the character classes.  */
+# include <ctype.h>
+
+/* 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
+
+# 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))
+
+# ifdef _tolower
+#  define TOLOWER(c) _tolower(c)
+# else
+#  define TOLOWER(c) tolower(c)
+# endif
+
+# 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
+\f
+# ifndef emacs
+/* 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 PARAMS ((void));
+
+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[(unsigned char) (c)]
+
+# endif /* emacs */
+\f
+/* Integer type for pointers.  */
+# if !defined _LIBC
+typedef unsigned long int uintptr_t;
+# 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__ */
+#    if 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)
+
+#  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))
+
+typedef char boolean;
+# define false 0
+# define true 1
+
+static reg_errcode_t byte_regex_compile _RE_ARGS ((const char *pattern, size_t size,
+                                                   reg_syntax_t syntax,
+                                                   struct re_pattern_buffer *bufp));
+static reg_errcode_t wcs_regex_compile _RE_ARGS ((const char *pattern, size_t size,
+                                                   reg_syntax_t syntax,
+                                                   struct re_pattern_buffer *bufp));
+
+static int byte_re_match_2_internal PARAMS ((struct re_pattern_buffer *bufp,
+                                            const char *string1, int size1,
+                                            const char *string2, int size2,
+                                            int pos,
+                                            struct re_registers *regs,
+                                            int stop));
+static int wcs_re_match_2_internal PARAMS ((struct re_pattern_buffer *bufp,
+                                           const char *cstring1, int csize1,
+                                           const char *cstring2, int csize2,
+                                           int pos,
+                                           struct re_registers *regs,
+                                           int stop,
+                                           wchar_t *string1, int size1,
+                                           wchar_t *string2, int size2,
+                                           int *mbs_offset1, int *mbs_offset2));
+static int byte_re_search_2 PARAMS ((struct re_pattern_buffer *bufp,
+                                    const char *string1, int size1,
+                                    const char *string2, int size2,
+                                    int startpos, int range,
+                                    struct re_registers *regs, int stop));
+static int wcs_re_search_2 PARAMS ((struct re_pattern_buffer *bufp,
+                                   const char *string1, int size1,
+                                   const char *string2, int size2,
+                                   int startpos, int range,
+                                   struct re_registers *regs, int stop));
+static int byte_re_compile_fastmap PARAMS ((struct re_pattern_buffer *bufp));
+static int wcs_re_compile_fastmap PARAMS ((struct re_pattern_buffer *bufp));
+
+\f
+/* 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,
+
+# ifdef MBS_SUPPORT
+       /* Same as exactn, but contains binary data.  */
+  exactn_bin,
+# endif
+
+        /* 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.  */
+        /* ifdef MBS_SUPPORT, following element is length of character
+          classes, length of collating symbols, length of equivalence
+          classes, length of character ranges, and length of characters.
+          Next, character class element, collating symbols elements,
+          equivalence class elements, range elements, and character
+          elements follow.
+          See regex_compile function.  */
+  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.  Then followed by one byte with the number of groups
+           inner to this one.  (This last has to be part of the
+           start_memory only because we need it in the on_failure_jump
+           of re_match_2.)  */
+  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, and one byte with the number of inner groups,
+           just like `start_memory'.  (We need the number of inner
+           groups here because we don't have any easy way of finding the
+           corresponding start_memory when we're at a stop_memory.)  */
+  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,
+
+       /* Same as jump, but marks the end of an alternative.  */
+  jump_past_alt,
+
+        /* Followed by two-byte relative address of place to resume at
+           in case of failure.  */
+        /* ifdef MBS_SUPPORT, the size of address is 1.  */
+  on_failure_jump,
+
+        /* Like on_failure_jump, but pushes a placeholder instead of the
+           current string position when executed.  */
+  on_failure_keep_string_jump,
+
+        /* Throw away latest failure point and then jump to following
+           two-byte relative address.  */
+        /* ifdef MBS_SUPPORT, the size of address is 1.  */
+  pop_failure_jump,
+
+        /* Change to pop_failure_jump if know won't have to backtrack to
+           match; otherwise change to jump.  This is used to jump
+           back to the beginning of a repeat.  If what follows this jump
+           clearly won't match what the repeat does, such that we can be
+           sure that there is no use backtracking out of repetitions
+           already matched, then we change it to a pop_failure_jump.
+           Followed by two-byte address.  */
+        /* ifdef MBS_SUPPORT, the size of address is 1.  */
+  maybe_pop_jump,
+
+        /* Jump to following two-byte address, and push a dummy failure
+           point. This failure point will be thrown away if an attempt
+           is made to use it for a failure.  A `+' construct makes this
+           before the first repeat.  Also used as an intermediary kind
+           of jump when compiling an alternative.  */
+        /* ifdef MBS_SUPPORT, the size of address is 1.  */
+  dummy_failure_jump,
+
+       /* Push a dummy failure point and continue.  Used at the end of
+          alternatives.  */
+  push_dummy_failure,
+
+        /* Followed by two-byte relative address and two-byte number n.
+           After matching N times, jump to the address upon failure.  */
+        /* ifdef MBS_SUPPORT, the size of address is 1.  */
+  succeed_n,
+
+        /* Followed by two-byte relative address, and two-byte number n.
+           Jump to the address N times, then fail.  */
+        /* ifdef MBS_SUPPORT, the size of address is 1.  */
+  jump_n,
+
+        /* Set the following two-byte relative address to the
+           subsequent two-byte number.  The address *includes* the two
+           bytes of number.  */
+        /* ifdef MBS_SUPPORT, the size of address is 1.  */
+  set_number_at,
+
+  wordchar,    /* Matches any word-constituent character.  */
+  notwordchar, /* Matches any char that is not a word-constituent.  */
+
+  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.  */
+
+# ifdef emacs
+  ,before_dot, /* Succeeds if before point.  */
+  at_dot,      /* Succeeds if at point.  */
+  after_dot,   /* Succeeds if after point.  */
+
+       /* 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
+# endif /* emacs */
+} re_opcode_t;
+#endif /* not INSIDE_RECURSION */
+\f
+
+#ifdef BYTE
+# define CHAR_T char
+# define UCHAR_T unsigned char
+# define COMPILED_BUFFER_VAR bufp->buffer
+# define OFFSET_ADDRESS_SIZE 2
+# define PREFIX(name) byte_##name
+# define ARG_PREFIX(name) name
+# define PUT_CHAR(c) putchar (c)
+#elif defined WCHAR
+# define CHAR_T wchar_t
+# define UCHAR_T wchar_t
+# define COMPILED_BUFFER_VAR wc_buffer
+# define OFFSET_ADDRESS_SIZE 1 /* the size which STORE_NUMBER macro use */
+# define CHAR_CLASS_SIZE ((__alignof__(wctype_t)+sizeof(wctype_t))/sizeof(CHAR_T)+1)
+# define PREFIX(name) wcs_##name
+# define ARG_PREFIX(name) c##name
+/* Should we use wide stream??  */
+# define PUT_CHAR(c) printf ("%C", c);
+# define TRUE 1
+# define FALSE 0
+#else
+# ifdef MBS_SUPPORT
+#  define WCHAR
+#  define INSIDE_RECURSION
+#  include "regex.c"
+#  undef INSIDE_RECURSION
+# endif
+# define BYTE
+# define INSIDE_RECURSION
+# include "regex.c"
+# undef INSIDE_RECURSION
+#endif
+
+#ifdef INSIDE_RECURSION
+/* Common operations on the compiled pattern.  */
+
+/* Store NUMBER in two contiguous bytes starting at DESTINATION.  */
+/* ifdef MBS_SUPPORT, we store NUMBER in 1 element.  */
+
+# ifdef WCHAR
+#  define STORE_NUMBER(destination, number)                            \
+  do {                                                                 \
+    *(destination) = (UCHAR_T)(number);                                \
+  } while (0)
+# else /* BYTE */
+#  define STORE_NUMBER(destination, number)                            \
+  do {                                                                 \
+    (destination)[0] = (number) & 0377;                                        \
+    (destination)[1] = (number) >> 8;                                  \
+  } while (0)
+# endif /* WCHAR */
+
+/* Same as STORE_NUMBER, except increment DESTINATION to
+   the byte after where the number is stored.  Therefore, DESTINATION
+   must be an lvalue.  */
+/* ifdef MBS_SUPPORT, we store NUMBER in 1 element.  */
+
+# define STORE_NUMBER_AND_INCR(destination, number)                    \
+  do {                                                                 \
+    STORE_NUMBER (destination, number);                                        \
+    (destination) += OFFSET_ADDRESS_SIZE;                              \
+  } while (0)
+
+/* Put into DESTINATION a number stored in two contiguous bytes starting
+   at SOURCE.  */
+/* ifdef MBS_SUPPORT, we store NUMBER in 1 element.  */
+
+# ifdef WCHAR
+#  define EXTRACT_NUMBER(destination, source)                          \
+  do {                                                                 \
+    (destination) = *(source);                                         \
+  } while (0)
+# else /* BYTE */
+#  define EXTRACT_NUMBER(destination, source)                          \
+  do {                                                                 \
+    (destination) = *(source) & 0377;                                  \
+    (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8;          \
+  } while (0)
+# endif
+
+# ifdef DEBUG
+static void PREFIX(extract_number) _RE_ARGS ((int *dest, UCHAR_T *source));
+static void
+PREFIX(extract_number) (dest, source)
+    int *dest;
+    UCHAR_T *source;
+{
+#  ifdef WCHAR
+  *dest = *source;
+#  else /* BYTE */
+  int temp = SIGN_EXTEND_CHAR (*(source + 1));
+  *dest = *source & 0377;
+  *dest += temp << 8;
+#  endif
+}
+
+#  ifndef EXTRACT_MACROS /* To debug the macros.  */
+#   undef EXTRACT_NUMBER
+#   define EXTRACT_NUMBER(dest, src) PREFIX(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) += OFFSET_ADDRESS_SIZE;                                   \
+  } while (0)
+
+# ifdef DEBUG
+static void PREFIX(extract_number_and_incr) _RE_ARGS ((int *destination,
+                                                      UCHAR_T **source));
+static void
+PREFIX(extract_number_and_incr) (destination, source)
+    int *destination;
+    UCHAR_T **source;
+{
+  PREFIX(extract_number) (destination, *source);
+  *source += OFFSET_ADDRESS_SIZE;
+}
+
+#  ifndef EXTRACT_MACROS
+#   undef EXTRACT_NUMBER_AND_INCR
+#   define EXTRACT_NUMBER_AND_INCR(dest, src) \
+  PREFIX(extract_number_and_incr) (&dest, &src)
+#  endif /* not EXTRACT_MACROS */
+
+# endif /* DEBUG */
+
+\f
+
+/* 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
+
+#  ifndef DEFINED_ONCE
+
+/* 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;
+
+#   define DEBUG_STATEMENT(e) e
+#   define DEBUG_PRINT1(x) if (debug) printf (x)
+#   define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
+#   define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
+#   define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
+#  endif /* not DEFINED_ONCE */
+
+#  define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)                        \
+  if (debug) PREFIX(print_partial_compiled_pattern) (s, e)
+#  define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)               \
+  if (debug) PREFIX(print_double_string) (w, s1, sz1, s2, sz2)
+
+
+/* Print the fastmap in human-readable form.  */
+
+#  ifndef DEFINED_ONCE
+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');
+}
+#  endif /* not DEFINED_ONCE */
+
+
+/* Print a compiled pattern string in human-readable form, starting at
+   the START pointer into it and ending just before the pointer END.  */
+
+void
+PREFIX(print_partial_compiled_pattern) (start, end)
+    UCHAR_T *start;
+    UCHAR_T *end;
+{
+  int mcnt, mcnt2;
+  UCHAR_T *p1;
+  UCHAR_T *p = start;
+  UCHAR_T *pend = end;
+
+  if (start == NULL)
+    {
+      printf ("(null)\n");
+      return;
+    }
+
+  /* Loop over pattern commands.  */
+  while (p < pend)
+    {
+#  ifdef _LIBC
+      printf ("%td:\t", p - start);
+#  else
+      printf ("%ld:\t", (long int) (p - start));
+#  endif
+
+      switch ((re_opcode_t) *p++)
+       {
+        case no_op:
+          printf ("/no_op");
+          break;
+
+       case exactn:
+         mcnt = *p++;
+          printf ("/exactn/%d", mcnt);
+          do
+           {
+              putchar ('/');
+             PUT_CHAR (*p++);
+            }
+          while (--mcnt);
+          break;
+
+#  ifdef MBS_SUPPORT
+       case exactn_bin:
+         mcnt = *p++;
+         printf ("/exactn_bin/%d", mcnt);
+          do
+           {
+             printf("/%lx", (long int) *p++);
+            }
+          while (--mcnt);
+          break;
+#  endif /* MBS_SUPPORT */
+
+       case start_memory:
+          mcnt = *p++;
+          printf ("/start_memory/%d/%ld", mcnt, (long int) *p++);
+          break;
+
+       case stop_memory:
+          mcnt = *p++;
+         printf ("/stop_memory/%d/%ld", mcnt, (long int) *p++);
+          break;
+
+       case duplicate:
+         printf ("/duplicate/%ld", (long int) *p++);
+         break;
+
+       case anychar:
+         printf ("/anychar");
+         break;
+
+       case charset:
+        case charset_not:
+          {
+#  ifdef WCHAR
+           int i, length;
+           wchar_t *workp = p;
+           printf ("/charset [%s",
+                   (re_opcode_t) *(workp - 1) == charset_not ? "^" : "");
+           p += 5;
+           length = *workp++; /* the length of char_classes */
+           for (i=0 ; i<length ; i++)
+             printf("[:%lx:]", (long int) *p++);
+           length = *workp++; /* the length of collating_symbol */
+           for (i=0 ; i<length ;)
+             {
+               printf("[.");
+               while(*p != 0)
+                 PUT_CHAR((i++,*p++));
+               i++,p++;
+               printf(".]");
+             }
+           length = *workp++; /* the length of equivalence_class */
+           for (i=0 ; i<length ;)
+             {
+               printf("[=");
+               while(*p != 0)
+                 PUT_CHAR((i++,*p++));
+               i++,p++;
+               printf("=]");
+             }
+           length = *workp++; /* the length of char_range */
+           for (i=0 ; i<length ; i++)
+             {
+               wchar_t range_start = *p++;
+               wchar_t range_end = *p++;
+               printf("%C-%C", range_start, range_end);
+             }
+           length = *workp++; /* the length of char */
+           for (i=0 ; i<length ; i++)
+             printf("%C", *p++);
+           putchar (']');
+#  else
+            register int c, last = -100;
+           register int in_range = 0;
+
+           printf ("/charset [%s",
+                   (re_opcode_t) *(p - 1) == charset_not ? "^" : "");
+
+            assert (p + *p < pend);
+
+            for (c = 0; c < 256; c++)
+             if (c / 8 < *p
+                 && (p[1 + (c/8)] & (1 << (c % 8))))
+               {
+                 /* Are we starting a range?  */
+                 if (last + 1 == c && ! in_range)
+                   {
+                     putchar ('-');
+                     in_range = 1;
+                   }
+                 /* Have we broken a range?  */
+                 else if (last + 1 != c && in_range)
+              {
+                     putchar (last);
+                     in_range = 0;
+                   }
+
+                 if (! in_range)
+                   putchar (c);
+
+                 last = c;
+              }
+
+           if (in_range)
+             putchar (last);
+
+           putchar (']');
+
+           p += 1 + *p;
+#  endif /* WCHAR */
+         }
+         break;
+
+       case begline:
+         printf ("/begline");
+          break;
+
+       case endline:
+          printf ("/endline");
+          break;
+
+       case on_failure_jump:
+          PREFIX(extract_number_and_incr) (&mcnt, &p);
+#  ifdef _LIBC
+         printf ("/on_failure_jump to %td", p + mcnt - start);
+#  else
+         printf ("/on_failure_jump to %ld", (long int) (p + mcnt - start));
+#  endif
+          break;
+
+       case on_failure_keep_string_jump:
+          PREFIX(extract_number_and_incr) (&mcnt, &p);
+#  ifdef _LIBC
+         printf ("/on_failure_keep_string_jump to %td", p + mcnt - start);
+#  else
+         printf ("/on_failure_keep_string_jump to %ld",
+                 (long int) (p + mcnt - start));
+#  endif
+          break;
+
+       case dummy_failure_jump:
+          PREFIX(extract_number_and_incr) (&mcnt, &p);
+#  ifdef _LIBC
+         printf ("/dummy_failure_jump to %td", p + mcnt - start);
+#  else
+         printf ("/dummy_failure_jump to %ld", (long int) (p + mcnt - start));
+#  endif
+          break;
+
+       case push_dummy_failure:
+          printf ("/push_dummy_failure");
+          break;
+
+        case maybe_pop_jump:
+          PREFIX(extract_number_and_incr) (&mcnt, &p);
+#  ifdef _LIBC
+         printf ("/maybe_pop_jump to %td", p + mcnt - start);
+#  else
+         printf ("/maybe_pop_jump to %ld", (long int) (p + mcnt - start));
+#  endif
+         break;
+
+        case pop_failure_jump:
+         PREFIX(extract_number_and_incr) (&mcnt, &p);
+#  ifdef _LIBC
+         printf ("/pop_failure_jump to %td", p + mcnt - start);
+#  else
+         printf ("/pop_failure_jump to %ld", (long int) (p + mcnt - start));
+#  endif
+         break;
+
+        case jump_past_alt:
+         PREFIX(extract_number_and_incr) (&mcnt, &p);
+#  ifdef _LIBC
+         printf ("/jump_past_alt to %td", p + mcnt - start);
+#  else
+         printf ("/jump_past_alt to %ld", (long int) (p + mcnt - start));
+#  endif
+         break;
+
+        case jump:
+         PREFIX(extract_number_and_incr) (&mcnt, &p);
+#  ifdef _LIBC
+         printf ("/jump to %td", p + mcnt - start);
+#  else
+         printf ("/jump to %ld", (long int) (p + mcnt - start));
+#  endif
+         break;
+
+        case succeed_n:
+          PREFIX(extract_number_and_incr) (&mcnt, &p);
+         p1 = p + mcnt;
+          PREFIX(extract_number_and_incr) (&mcnt2, &p);
+#  ifdef _LIBC
+         printf ("/succeed_n to %td, %d times", p1 - start, mcnt2);
+#  else
+         printf ("/succeed_n to %ld, %d times",
+                 (long int) (p1 - start), mcnt2);
+#  endif
+          break;
+
+        case jump_n:
+          PREFIX(extract_number_and_incr) (&mcnt, &p);
+         p1 = p + mcnt;
+          PREFIX(extract_number_and_incr) (&mcnt2, &p);
+         printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
+          break;
+
+        case set_number_at:
+          PREFIX(extract_number_and_incr) (&mcnt, &p);
+         p1 = p + mcnt;
+          PREFIX(extract_number_and_incr) (&mcnt2, &p);
+#  ifdef _LIBC
+         printf ("/set_number_at location %td to %d", p1 - start, mcnt2);
+#  else
+         printf ("/set_number_at location %ld to %d",
+                 (long int) (p1 - start), mcnt2);
+#  endif
+          break;
+
+        case wordbound:
+         printf ("/wordbound");
+         break;
+
+       case notwordbound:
+         printf ("/notwordbound");
+          break;
+
+       case wordbeg:
+         printf ("/wordbeg");
+         break;
+
+       case wordend:
+         printf ("/wordend");
+         break;
+
+#  ifdef emacs
+       case before_dot:
+         printf ("/before_dot");
+          break;
+
+       case at_dot:
+         printf ("/at_dot");
+          break;
+
+       case after_dot:
+         printf ("/after_dot");
+          break;
+
+       case syntaxspec:
+          printf ("/syntaxspec");
+         mcnt = *p++;
+         printf ("/%d", mcnt);
+          break;
+
+       case notsyntaxspec:
+          printf ("/notsyntaxspec");
+         mcnt = *p++;
+         printf ("/%d", mcnt);
+         break;
+#  endif /* emacs */
+
+       case wordchar:
+         printf ("/wordchar");
+          break;
+
+       case notwordchar:
+         printf ("/notwordchar");
+          break;
+
+       case begbuf:
+         printf ("/begbuf");
+          break;
+
+       case endbuf:
+         printf ("/endbuf");
+          break;
+
+        default:
+          printf ("?%ld", (long int) *(p-1));
+       }
+
+      putchar ('\n');
+    }
+
+#  ifdef _LIBC
+  printf ("%td:\tend of pattern.\n", p - start);
+#  else
+  printf ("%ld:\tend of pattern.\n", (long int) (p - start));
+#  endif
+}
+
+
+void
+PREFIX(print_compiled_pattern) (bufp)
+    struct re_pattern_buffer *bufp;
+{
+  UCHAR_T *buffer = (UCHAR_T*) bufp->buffer;
+
+  PREFIX(print_partial_compiled_pattern) (buffer, buffer
+                                 + bufp->used / sizeof(UCHAR_T));
+  printf ("%ld bytes used/%ld bytes allocated.\n",
+         bufp->used, bufp->allocated);
+
+  if (bufp->fastmap_accurate && bufp->fastmap)
+    {
+      printf ("fastmap: ");
+      print_fastmap (bufp->fastmap);
+    }
+
+#  ifdef _LIBC
+  printf ("re_nsub: %Zd\t", bufp->re_nsub);
+#  else
+  printf ("re_nsub: %ld\t", (long int) bufp->re_nsub);
+#  endif
+  printf ("regs_alloc: %d\t", bufp->regs_allocated);
+  printf ("can_be_null: %d\t", bufp->can_be_null);
+  printf ("newline_anchor: %d\n", bufp->newline_anchor);
+  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);
+  /* Perhaps we should print the translate table?  */
+}
+
+
+void
+PREFIX(print_double_string) (where, string1, size1, string2, size2)
+    const CHAR_T *where;
+    const CHAR_T *string1;
+    const CHAR_T *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++)
+           PUT_CHAR (string1[this_char]);
+
+          where = string2;
+        }
+
+      for (this_char = where - string2; this_char < size2; this_char++)
+        PUT_CHAR (string2[this_char]);
+    }
+}
+
+#  ifndef DEFINED_ONCE
+void
+printchar (c)
+     int c;
+{
+  putc (c, stderr);
+}
+#  endif
+
+# else /* not DEBUG */
+
+#  ifndef DEFINED_ONCE
+#   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)
+#  endif /* not DEFINED_ONCE */
+#  define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
+#  define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)
+
+# endif /* not DEBUG */
+
+\f
+
+# ifdef WCHAR
+/* This  convert a multibyte string to a wide character string.
+   And write their correspondances to offset_buffer(see below)
+   and write whether each wchar_t is binary data to is_binary.
+   This assume invalid multibyte sequences as binary data.
+   We assume offset_buffer and is_binary is already allocated
+   enough space.  */
+
+static size_t convert_mbs_to_wcs (CHAR_T *dest, const unsigned char* src,
+                                 size_t len, int *offset_buffer,
+                                 char *is_binary);
+static size_t
+convert_mbs_to_wcs (dest, src, len, offset_buffer, is_binary)
+     CHAR_T *dest;
+     const unsigned char* src;
+     size_t len; /* the length of multibyte string.  */
+
+     /* It hold correspondances between src(char string) and
+       dest(wchar_t string) for optimization.
+       e.g. src  = "xxxyzz"
+             dest = {'X', 'Y', 'Z'}
+             (each "xxx", "y" and "zz" represent one multibyte character
+              corresponding to 'X', 'Y' and 'Z'.)
+         offset_buffer = {0, 0+3("xxx"), 0+3+1("y"), 0+3+1+2("zz")}
+                       = {0, 3, 4, 6}
+     */
+     int *offset_buffer;
+     char *is_binary;
+{
+  wchar_t *pdest = dest;
+  const unsigned char *psrc = src;
+  size_t wc_count = 0;
+
+  mbstate_t mbs;
+  int i, consumed;
+  size_t mb_remain = len;
+  size_t mb_count = 0;
+
+  /* Initialize the conversion state.  */
+  memset (&mbs, 0, sizeof (mbstate_t));
+
+  offset_buffer[0] = 0;
+  for( ; mb_remain > 0 ; ++wc_count, ++pdest, mb_remain -= consumed,
+        psrc += consumed)
+    {
+      consumed = mbrtowc (pdest, psrc, mb_remain, &mbs);
+
+      if (consumed <= 0)
+       /* failed to convert. maybe src contains binary data.
+          So we consume 1 byte manualy.  */
+       {
+         *pdest = *psrc;
+         consumed = 1;
+         is_binary[wc_count] = TRUE;
+       }
+      else
+       is_binary[wc_count] = FALSE;
+      /* In sjis encoding, we use yen sign as escape character in
+        place of reverse solidus. So we convert 0x5c(yen sign in
+        sjis) to not 0xa5(yen sign in UCS2) but 0x5c(reverse
+        solidus in UCS2).  */
+      if (consumed == 1 && (int) *psrc == 0x5c && (int) *pdest == 0xa5)
+       *pdest = (wchar_t) *psrc;
+
+      offset_buffer[wc_count + 1] = mb_count += consumed;
+    }
+
+  /* Fill remain of the buffer with sentinel.  */
+  for (i = wc_count + 1 ; i <= len ; i++)
+    offset_buffer[i] = mb_count + 1;
+
+  return wc_count;
+}
+
+# endif /* WCHAR */
+
+#else /* not INSIDE_RECURSION */
+
+/* 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;
+# ifdef DEBUG
+  if (syntax & RE_DEBUG)
+    debug = 1;
+  else if (debug) /* was on but now is not */
+    debug = 0;
+# endif /* DEBUG */
+  return ret;
+}
+# ifdef _LIBC
+weak_alias (__re_set_syntax, re_set_syntax)
+# endif
+\f
+/* 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[] =
+  {
+# define REG_NOERROR_IDX       0
+    gettext_noop ("Success")   /* REG_NOERROR */
+    "\0"
+# define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success")
+    gettext_noop ("No match")  /* REG_NOMATCH */
+    "\0"
+# define REG_BADPAT_IDX        (REG_NOMATCH_IDX + sizeof "No match")
+    gettext_noop ("Invalid regular expression") /* REG_BADPAT */
+    "\0"
+# define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression")
+    gettext_noop ("Invalid collation character") /* REG_ECOLLATE */
+    "\0"
+# define REG_ECTYPE_IDX        (REG_ECOLLATE_IDX + sizeof "Invalid collation character")
+    gettext_noop ("Invalid character class name") /* REG_ECTYPE */
+    "\0"
+# define REG_EESCAPE_IDX       (REG_ECTYPE_IDX + sizeof "Invalid character class name")
+    gettext_noop ("Trailing backslash") /* REG_EESCAPE */
+    "\0"
+# define REG_ESUBREG_IDX       (REG_EESCAPE_IDX + sizeof "Trailing backslash")
+    gettext_noop ("Invalid back reference") /* REG_ESUBREG */
+    "\0"
+# define REG_EBRACK_IDX        (REG_ESUBREG_IDX + sizeof "Invalid back reference")
+    gettext_noop ("Unmatched [ or [^") /* REG_EBRACK */
+    "\0"
+# define REG_EPAREN_IDX        (REG_EBRACK_IDX + sizeof "Unmatched [ or [^")
+    gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */
+    "\0"
+# define REG_EBRACE_IDX        (REG_EPAREN_IDX + sizeof "Unmatched ( or \\(")
+    gettext_noop ("Unmatched \\{") /* REG_EBRACE */
+    "\0"
+# define REG_BADBR_IDX (REG_EBRACE_IDX + sizeof "Unmatched \\{")
+    gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */
+    "\0"
+# define REG_ERANGE_IDX        (REG_BADBR_IDX + sizeof "Invalid content of \\{\\}")
+    gettext_noop ("Invalid range end") /* REG_ERANGE */
+    "\0"
+# define REG_ESPACE_IDX        (REG_ERANGE_IDX + sizeof "Invalid range end")
+    gettext_noop ("Memory exhausted") /* REG_ESPACE */
+    "\0"
+# define REG_BADRPT_IDX        (REG_ESPACE_IDX + sizeof "Memory exhausted")
+    gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */
+    "\0"
+# define REG_EEND_IDX  (REG_BADRPT_IDX + sizeof "Invalid preceding regular expression")
+    gettext_noop ("Premature end of regular expression") /* REG_EEND */
+    "\0"
+# define REG_ESIZE_IDX (REG_EEND_IDX + sizeof "Premature end of regular expression")
+    gettext_noop ("Regular expression too big") /* REG_ESIZE */
+    "\0"
+# define REG_ERPAREN_IDX       (REG_ESIZE_IDX + sizeof "Regular expression too big")
+    gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
+  };
+
+static const size_t re_error_msgid_idx[] =
+  {
+    REG_NOERROR_IDX,
+    REG_NOMATCH_IDX,
+    REG_BADPAT_IDX,
+    REG_ECOLLATE_IDX,
+    REG_ECTYPE_IDX,
+    REG_EESCAPE_IDX,
+    REG_ESUBREG_IDX,
+    REG_EBRACK_IDX,
+    REG_EPAREN_IDX,
+    REG_EBRACE_IDX,
+    REG_BADBR_IDX,
+    REG_ERANGE_IDX,
+    REG_ESPACE_IDX,
+    REG_BADRPT_IDX,
+    REG_EEND_IDX,
+    REG_ESIZE_IDX,
+    REG_ERPAREN_IDX
+  };
+\f
+#endif /* INSIDE_RECURSION */
+
+#ifndef DEFINED_ONCE
+/* 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
+#endif /* not DEFINED_ONCE */
+\f
+#ifdef INSIDE_RECURSION
+/* 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.  */
+
+
+/* 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 5
+# endif
+
+/* Roughly the maximum number of failure points on the stack.  Would be
+   exactly that if always used MAX_FAILURE_ITEMS items each time we failed.
+   This is a variable only so users of regex can assign to it; we never
+   change it ourselves.  */
+
+# ifdef INT_IS_16BIT
+
+#  ifndef DEFINED_ONCE
+#   if defined MATCH_MAY_ALLOCATE
+/* 4400 was enough to cause a crash on Alpha OSF/1,
+   whose default stack limit is 2mb.  */
+long int re_max_failures = 4000;
+#   else
+long int re_max_failures = 2000;
+#   endif
+#  endif
+
+union PREFIX(fail_stack_elt)
+{
+  UCHAR_T *pointer;
+  long int integer;
+};
+
+typedef union PREFIX(fail_stack_elt) PREFIX(fail_stack_elt_t);
+
+typedef struct
+{
+  PREFIX(fail_stack_elt_t) *stack;
+  unsigned long int size;
+  unsigned long int avail;             /* Offset of next open position.  */
+} PREFIX(fail_stack_type);
+
+# else /* not INT_IS_16BIT */
+
+#  ifndef DEFINED_ONCE
+#   if defined MATCH_MAY_ALLOCATE
+/* 4400 was enough to cause a crash on Alpha OSF/1,
+   whose default stack limit is 2mb.  */
+int re_max_failures = 4000;
+#   else
+int re_max_failures = 2000;
+#   endif
+#  endif
+
+union PREFIX(fail_stack_elt)
+{
+  UCHAR_T *pointer;
+  int integer;
+};
+
+typedef union PREFIX(fail_stack_elt) PREFIX(fail_stack_elt_t);
+
+typedef struct
+{
+  PREFIX(fail_stack_elt_t) *stack;
+  unsigned size;
+  unsigned avail;                      /* Offset of next open position.  */
+} PREFIX(fail_stack_type);
+
+# endif /* INT_IS_16BIT */
+
+# ifndef DEFINED_ONCE
+#  define FAIL_STACK_EMPTY()     (fail_stack.avail == 0)
+#  define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
+#  define FAIL_STACK_FULL()      (fail_stack.avail == fail_stack.size)
+# endif
+
+
+/* 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 = (PREFIX(fail_stack_elt_t) *)            \
+      REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (PREFIX(fail_stack_elt_t))); \
+                                                                       \
+    if (fail_stack.stack == NULL)                              \
+      return -2;                                                       \
+                                                                       \
+    fail_stack.size = INIT_FAILURE_ALLOC;                      \
+    fail_stack.avail = 0;                                      \
+  } while (0)
+
+#  define RESET_FAIL_STACK()  REGEX_FREE_STACK (fail_stack.stack)
+# else
+#  define INIT_FAIL_STACK()                                            \
+  do {                                                                 \
+    fail_stack.avail = 0;                                      \
+  } while (0)
+
+#  define RESET_FAIL_STACK()
+# endif
+
+
+/* Double the size of FAIL_STACK, up to 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.   */
+
+# define DOUBLE_FAIL_STACK(fail_stack)                                 \
+  ((fail_stack).size > (unsigned) (re_max_failures * MAX_FAILURE_ITEMS)        \
+   ? 0                                                                 \
+   : ((fail_stack).stack = (PREFIX(fail_stack_elt_t) *)                        \
+        REGEX_REALLOCATE_STACK ((fail_stack).stack,                    \
+          (fail_stack).size * sizeof (PREFIX(fail_stack_elt_t)),       \
+          ((fail_stack).size << 1) * sizeof (PREFIX(fail_stack_elt_t))),\
+                                                                       \
+      (fail_stack).stack == NULL                                       \
+      ? 0                                                              \
+      : ((fail_stack).size <<= 1,                                      \
+         1)))
+
+
+/* Push pointer POINTER on FAIL_STACK.
+   Return 1 if was able to do so and 0 if ran out of memory allocating
+   space to do so.  */
+# define PUSH_PATTERN_OP(POINTER, FAIL_STACK)                          \
+  ((FAIL_STACK_FULL ()                                                 \
+    && !DOUBLE_FAIL_STACK (FAIL_STACK))                                        \
+   ? 0                                                                 \
+   : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER,      \
+      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 = (UCHAR_T *) (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]
+
+/* Used to omit pushing failure point id's when we're not debugging.  */
+# ifdef DEBUG
+#  define DEBUG_PUSH PUSH_FAILURE_INT
+#  define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT ()
+# else
+#  define DEBUG_PUSH(item)
+#  define DEBUG_POP(item_addr)
+# endif
+
+
+/* Push the information about the state we will need
+   if we ever fail back to it.
+
+   Requires variables fail_stack, regstart, regend, reg_info, and
+   num_regs_pushed be declared.  DOUBLE_FAIL_STACK requires `destination'
+   be declared.
+
+   Does `return FAILURE_CODE' if runs out of memory.  */
+
+# define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \
+  do {                                                                 \
+    char *destination;                                                 \
+    /* Must be int, so when we don't save any registers, the arithmetic        \
+       of 0 + -1 isn't done as unsigned.  */                           \
+    /* Can't be int, since there is not a shred of a guarantee that int        \
+       is wide enough to hold a value of something to which pointer can        \
+       be assigned */                                                  \
+    active_reg_t this_reg;                                             \
+                                                                       \
+    DEBUG_STATEMENT (failure_id++);                                    \
+    DEBUG_STATEMENT (nfailure_points_pushed++);                                \
+    DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id);          \
+    DEBUG_PRINT2 ("  Before push, next avail: %d\n", (fail_stack).avail);\
+    DEBUG_PRINT2 ("                     size: %d\n", (fail_stack).size);\
+                                                                       \
+    DEBUG_PRINT2 ("  slots needed: %ld\n", NUM_FAILURE_ITEMS);         \
+    DEBUG_PRINT2 ("     available: %d\n", REMAINING_AVAIL_SLOTS);      \
+                                                                       \
+    /* Ensure we have enough space allocated for what we will push.  */        \
+    while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS)                  \
+      {                                                                        \
+        if (!DOUBLE_FAIL_STACK (fail_stack))                           \
+          return failure_code;                                         \
+                                                                       \
+        DEBUG_PRINT2 ("\n  Doubled stack; size now: %d\n",             \
+                      (fail_stack).size);                              \
+        DEBUG_PRINT2 ("  slots available: %d\n", REMAINING_AVAIL_SLOTS);\
+      }                                                                        \
+                                                                       \
+    /* Push the info, starting with the registers.  */                 \
+    DEBUG_PRINT1 ("\n");                                               \
+                                                                       \
+    if (1)                                                             \
+      for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
+          this_reg++)                                                  \
+       {                                                               \
+         DEBUG_PRINT2 ("  Pushing reg: %lu\n", this_reg);              \
+         DEBUG_STATEMENT (num_regs_pushed++);                          \
+                                                                       \
+         DEBUG_PRINT2 ("    start: %p\n", regstart[this_reg]);         \
+         PUSH_FAILURE_POINTER (regstart[this_reg]);                    \
+                                                                       \
+         DEBUG_PRINT2 ("    end: %p\n", regend[this_reg]);             \
+         PUSH_FAILURE_POINTER (regend[this_reg]);                      \
+                                                                       \
+         DEBUG_PRINT2 ("    info: %p\n      ",                         \
+                       reg_info[this_reg].word.pointer);               \
+         DEBUG_PRINT2 (" match_null=%d",                               \
+                       REG_MATCH_NULL_STRING_P (reg_info[this_reg]));  \
+         DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg]));  \
+         DEBUG_PRINT2 (" matched_something=%d",                        \
+                       MATCHED_SOMETHING (reg_info[this_reg]));        \
+         DEBUG_PRINT2 (" ever_matched=%d",                             \
+                       EVER_MATCHED_SOMETHING (reg_info[this_reg]));   \
+         DEBUG_PRINT1 ("\n");                                          \
+         PUSH_FAILURE_ELT (reg_info[this_reg].word);                   \
+       }                                                               \
+                                                                       \
+    DEBUG_PRINT2 ("  Pushing  low active reg: %ld\n", lowest_active_reg);\
+    PUSH_FAILURE_INT (lowest_active_reg);                              \
+                                                                       \
+    DEBUG_PRINT2 ("  Pushing high active reg: %ld\n", highest_active_reg);\
+    PUSH_FAILURE_INT (highest_active_reg);                             \
+                                                                       \
+    DEBUG_PRINT2 ("  Pushing pattern %p:\n", pattern_place);           \
+    DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend);          \
+    PUSH_FAILURE_POINTER (pattern_place);                              \
+                                                                       \
+    DEBUG_PRINT2 ("  Pushing string %p: `", string_place);             \
+    DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2,   \
+                                size2);                                \
+    DEBUG_PRINT1 ("'\n");                                              \
+    PUSH_FAILURE_POINTER (string_place);                               \
+                                                                       \
+    DEBUG_PRINT2 ("  Pushing failure id: %u\n", failure_id);           \
+    DEBUG_PUSH (failure_id);                                           \
+  } while (0)
+
+# ifndef DEFINED_ONCE
+/* This is the number of items that are pushed and popped on the stack
+   for each register.  */
+#  define NUM_REG_ITEMS  3
+
+/* Individual items aside from the registers.  */
+#  ifdef DEBUG
+#   define NUM_NONREG_ITEMS 5 /* Includes failure point id.  */
+#  else
+#   define NUM_NONREG_ITEMS 4
+#  endif
+
+/* We push at most this many items on the stack.  */
+/* We used to use (num_regs - 1), which is the number of registers
+   this regexp will save; but that was changed to 5
+   to avoid stack overflow for a regexp with lots of parens.  */
+#  define MAX_FAILURE_ITEMS (5 * NUM_REG_ITEMS + NUM_NONREG_ITEMS)
+
+/* We actually push this many items.  */
+#  define NUM_FAILURE_ITEMS                            \
+  (((0                                                 \
+     ? 0 : highest_active_reg - lowest_active_reg + 1) \
+    * NUM_REG_ITEMS)                                   \
+   + NUM_NONREG_ITEMS)
+
+/* How many items can still be added to the stack without overflowing it.  */
+#  define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)
+# endif /* not DEFINED_ONCE */
+
+
+/* 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.
+     LOW_REG, HIGH_REG -- the highest and lowest active registers.
+     REGSTART, REGEND -- arrays of string positions.
+     REG_INFO -- array of information about each subexpression.
+
+   Also assumes the variables `fail_stack' and (if debugging), `bufp',
+   `pend', `string1', `size1', `string2', and `size2'.  */
+# define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
+{                                                                      \
+  DEBUG_STATEMENT (unsigned failure_id;)                               \
+  active_reg_t this_reg;                                               \
+  const UCHAR_T *string_temp;                                          \
+                                                                       \
+  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);    \
+                                                                       \
+  assert (fail_stack.avail >= NUM_NONREG_ITEMS);                       \
+                                                                       \
+  DEBUG_POP (&failure_id);                                             \
+  DEBUG_PRINT2 ("  Popping failure id: %u\n", failure_id);             \
+                                                                       \
+  /* 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.  */        \
+  string_temp = POP_FAILURE_POINTER ();                                        \
+  if (string_temp != NULL)                                             \
+    str = (const CHAR_T *) string_temp;                                        \
+                                                                       \
+  DEBUG_PRINT2 ("  Popping string %p: `", str);                                \
+  DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2);     \
+  DEBUG_PRINT1 ("'\n");                                                        \
+                                                                       \
+  pat = (UCHAR_T *) POP_FAILURE_POINTER ();                            \
+  DEBUG_PRINT2 ("  Popping pattern %p:\n", pat);                       \
+  DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend);                      \
+                                                                       \
+  /* Restore register info.  */                                                \
+  high_reg = (active_reg_t) POP_FAILURE_INT ();                                \
+  DEBUG_PRINT2 ("  Popping high active reg: %ld\n", high_reg);         \
+                                                                       \
+  low_reg = (active_reg_t) POP_FAILURE_INT ();                         \
+  DEBUG_PRINT2 ("  Popping  low active reg: %ld\n", low_reg);          \
+                                                                       \
+  if (1)                                                               \
+    for (this_reg = high_reg; this_reg >= low_reg; this_reg--)         \
+      {                                                                        \
+       DEBUG_PRINT2 ("    Popping reg: %ld\n", this_reg);              \
+                                                                       \
+       reg_info[this_reg].word = POP_FAILURE_ELT ();                   \
+       DEBUG_PRINT2 ("      info: %p\n",                               \
+                     reg_info[this_reg].word.pointer);                 \
+                                                                       \
+       regend[this_reg] = (const CHAR_T *) POP_FAILURE_POINTER ();     \
+       DEBUG_PRINT2 ("      end: %p\n", regend[this_reg]);             \
+                                                                       \
+       regstart[this_reg] = (const CHAR_T *) POP_FAILURE_POINTER ();   \
+       DEBUG_PRINT2 ("      start: %p\n", regstart[this_reg]);         \
+      }                                                                        \
+  else                                                                 \
+    {                                                                  \
+      for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \
+       {                                                               \
+         reg_info[this_reg].word.integer = 0;                          \
+         regend[this_reg] = 0;                                         \
+         regstart[this_reg] = 0;                                       \
+       }                                                               \
+      highest_active_reg = high_reg;                                   \
+    }                                                                  \
+                                                                       \
+  set_regs_matched_done = 0;                                           \
+  DEBUG_STATEMENT (nfailure_points_popped++);                          \
+} /* POP_FAILURE_POINT */
+\f
+/* Structure for per-register (a.k.a. per-group) information.
+   Other register information, such as the
+   starting and ending positions (which are addresses), and the list of
+   inner groups (which is a bits list) are maintained in separate
+   variables.
+
+   We are making a (strictly speaking) nonportable assumption here: that
+   the compiler will pack our bit fields into something that fits into
+   the type of `word', i.e., is something that fits into one item on the
+   failure stack.  */
+
+
+/* Declarations and macros for re_match_2.  */
+
+typedef union
+{
+  PREFIX(fail_stack_elt_t) word;
+  struct
+  {
+      /* This field is one if this group can match the empty string,
+         zero if not.  If not yet determined,  `MATCH_NULL_UNSET_VALUE'.  */
+# define MATCH_NULL_UNSET_VALUE 3
+    unsigned match_null_string_p : 2;
+    unsigned is_active : 1;
+    unsigned matched_something : 1;
+    unsigned ever_matched_something : 1;
+  } bits;
+} PREFIX(register_info_type);
+
+# ifndef DEFINED_ONCE
+#  define REG_MATCH_NULL_STRING_P(R)  ((R).bits.match_null_string_p)
+#  define IS_ACTIVE(R)  ((R).bits.is_active)
+#  define MATCHED_SOMETHING(R)  ((R).bits.matched_something)
+#  define EVER_MATCHED_SOMETHING(R)  ((R).bits.ever_matched_something)
+
+
+/* Call this when have matched a real character; it sets `matched' flags
+   for the subexpressions which we are currently inside.  Also records
+   that those subexprs have matched.  */
+#  define SET_REGS_MATCHED()                                           \
+  do                                                                   \
+    {                                                                  \
+      if (!set_regs_matched_done)                                      \
+       {                                                               \
+         active_reg_t r;                                               \
+         set_regs_matched_done = 1;                                    \
+         for (r = lowest_active_reg; r <= highest_active_reg; r++)     \
+           {                                                           \
+             MATCHED_SOMETHING (reg_info[r])                           \
+               = EVER_MATCHED_SOMETHING (reg_info[r])                  \
+               = 1;                                                    \
+           }                                                           \
+       }                                                               \
+    }                                                                  \
+  while (0)
+# endif /* not DEFINED_ONCE */
+
+/* Registers are set to a sentinel when they haven't yet matched.  */
+static CHAR_T PREFIX(reg_unset_dummy);
+# define REG_UNSET_VALUE (&PREFIX(reg_unset_dummy))
+# define REG_UNSET(e) ((e) == REG_UNSET_VALUE)
+
+/* Subroutine declarations and macros for regex_compile.  */
+static void PREFIX(store_op1) _RE_ARGS ((re_opcode_t op, UCHAR_T *loc, int arg));
+static void PREFIX(store_op2) _RE_ARGS ((re_opcode_t op, UCHAR_T *loc,
+                                int arg1, int arg2));
+static void PREFIX(insert_op1) _RE_ARGS ((re_opcode_t op, UCHAR_T *loc,
+                                 int arg, UCHAR_T *end));
+static void PREFIX(insert_op2) _RE_ARGS ((re_opcode_t op, UCHAR_T *loc,
+                                 int arg1, int arg2, UCHAR_T *end));
+static boolean PREFIX(at_begline_loc_p) _RE_ARGS ((const CHAR_T *pattern,
+                                          const CHAR_T *p,
+                                          reg_syntax_t syntax));
+static boolean PREFIX(at_endline_loc_p) _RE_ARGS ((const CHAR_T *p,
+                                          const CHAR_T *pend,
+                                          reg_syntax_t syntax));
+# ifdef WCHAR
+static reg_errcode_t wcs_compile_range _RE_ARGS ((CHAR_T range_start,
+                                                 const CHAR_T **p_ptr,
+                                                 const CHAR_T *pend,
+                                                 char *translate,
+                                                 reg_syntax_t syntax,
+                                                 UCHAR_T *b,
+                                                 CHAR_T *char_set));
+static void insert_space _RE_ARGS ((int num, CHAR_T *loc, CHAR_T *end));
+# else /* BYTE */
+static reg_errcode_t byte_compile_range _RE_ARGS ((unsigned int range_start,
+                                                  const char **p_ptr,
+                                                  const char *pend,
+                                                  char *translate,
+                                                  reg_syntax_t syntax,
+                                                  unsigned char *b));
+# endif /* WCHAR */
+
+/* Fetch the next character in the uncompiled pattern---translating it
+   if necessary.  Also cast from a signed character in the constant
+   string passed to us by the user to an unsigned char that we can use
+   as an array index (in, e.g., `translate').  */
+/* ifdef MBS_SUPPORT, we translate only if character <= 0xff,
+   because it is impossible to allocate 4GB array for some encodings
+   which have 4 byte character_set like UCS4.  */
+# ifndef PATFETCH
+#  ifdef WCHAR
+#   define PATFETCH(c)                                                 \
+  do {if (p == pend) return REG_EEND;                                  \
+    c = (UCHAR_T) *p++;                                                        \
+    if (translate && (c <= 0xff)) c = (UCHAR_T) translate[c];          \
+  } while (0)
+#  else /* BYTE */
+#   define PATFETCH(c)                                                 \
+  do {if (p == pend) return REG_EEND;                                  \
+    c = (unsigned char) *p++;                                          \
+    if (translate) c = (unsigned char) translate[c];                   \
+  } while (0)
+#  endif /* WCHAR */
+# endif
+
+/* Fetch the next character in the uncompiled pattern, with no
+   translation.  */
+# define PATFETCH_RAW(c)                                               \
+  do {if (p == pend) return REG_EEND;                                  \
+    c = (UCHAR_T) *p++;                                                \
+  } while (0)
+
+/* Go backwards one character in the pattern.  */
+# define PATUNFETCH p--
+
+
+/* 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.  */
+/* ifdef MBS_SUPPORT, we translate only if character <= 0xff,
+   because it is impossible to allocate 4GB array for some encodings
+   which have 4 byte character_set like UCS4.  */
+
+# ifndef TRANSLATE
+#  ifdef WCHAR
+#   define TRANSLATE(d) \
+  ((translate && ((UCHAR_T) (d)) <= 0xff) \
+   ? (char) translate[(unsigned char) (d)] : (d))
+# else /* BYTE */
+#   define TRANSLATE(d) \
+  (translate ? (char) translate[(unsigned char) (d)] : (d))
+#  endif /* WCHAR */
+# 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 * sizeof(UCHAR_T))
+
+/* Make sure we have at least N more bytes of space in buffer.  */
+# ifdef WCHAR
+#  define GET_BUFFER_SPACE(n)                                          \
+    while (((unsigned long)b - (unsigned long)COMPILED_BUFFER_VAR      \
+            + (n)*sizeof(CHAR_T)) > bufp->allocated)                   \
+      EXTEND_BUFFER ()
+# else /* BYTE */
+#  define GET_BUFFER_SPACE(n)                                          \
+    while ((unsigned long) (b - bufp->buffer + (n)) > bufp->allocated) \
+      EXTEND_BUFFER ()
+# endif /* WCHAR */
+
+/* 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++ = (UCHAR_T) (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++ = (UCHAR_T) (c1);                                             \
+    *b++ = (UCHAR_T) (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++ = (UCHAR_T) (c1);                                             \
+    *b++ = (UCHAR_T) (c2);                                             \
+    *b++ = (UCHAR_T) (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) \
+ PREFIX(store_op1) (op, loc, (int) ((to) - (loc) - (1 + OFFSET_ADDRESS_SIZE)))
+
+/* Likewise, for a two-argument jump.  */
+# define STORE_JUMP2(op, loc, to, arg) \
+  PREFIX(store_op2) (op, loc, (int) ((to) - (loc) - (1 + OFFSET_ADDRESS_SIZE)), arg)
+
+/* Like `STORE_JUMP', but for inserting.  Assume `b' is the buffer end.  */
+# define INSERT_JUMP(op, loc, to) \
+  PREFIX(insert_op1) (op, loc, (int) ((to) - (loc) - (1 + OFFSET_ADDRESS_SIZE)), b)
+
+/* Like `STORE_JUMP2', but for inserting.  Assume `b' is the buffer end.  */
+# define INSERT_JUMP2(op, loc, to, arg) \
+  PREFIX(insert_op2) (op, loc, (int) ((to) - (loc) - (1 + OFFSET_ADDRESS_SIZE)),\
+             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!!  */
+# ifndef DEFINED_ONCE
+#  if defined _MSC_VER  && !defined WIN32
+/* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
+   The REALLOC define eliminates a flurry of conversion warnings,
+   but is not required. */
+#   define MAX_BUF_SIZE  65500L
+#   define REALLOC(p,s) realloc ((p), (size_t) (s))
+#  else
+#   define MAX_BUF_SIZE (1L << 16)
+#   define REALLOC(p,s) realloc ((p), (s))
+#  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
+# endif /* not DEFINED_ONCE */
+
+# ifdef WCHAR
+#  define EXTEND_BUFFER()                                              \
+  do {                                                                 \
+    UCHAR_T *old_buffer = COMPILED_BUFFER_VAR;                         \
+    int wchar_count;                                                   \
+    if (bufp->allocated + sizeof(UCHAR_T) > MAX_BUF_SIZE)              \
+      return REG_ESIZE;                                                        \
+    bufp->allocated <<= 1;                                             \
+    if (bufp->allocated > MAX_BUF_SIZE)                                        \
+      bufp->allocated = MAX_BUF_SIZE;                                  \
+    /* How many characters the new buffer can have?  */                        \
+    wchar_count = bufp->allocated / sizeof(UCHAR_T);                   \
+    if (wchar_count == 0) wchar_count = 1;                             \
+    /* Truncate the buffer to CHAR_T align.  */                        \
+    bufp->allocated = wchar_count * sizeof(UCHAR_T);                   \
+    RETALLOC (COMPILED_BUFFER_VAR, wchar_count, UCHAR_T);              \
+    bufp->buffer = (char*)COMPILED_BUFFER_VAR;                         \
+    if (COMPILED_BUFFER_VAR == NULL)                                   \
+      return REG_ESPACE;                                               \
+    /* If the buffer moved, move all the pointers into it.  */         \
+    if (old_buffer != COMPILED_BUFFER_VAR)                             \
+      {                                                                        \
+       int incr = COMPILED_BUFFER_VAR - 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)
+# else /* BYTE */
+#  define EXTEND_BUFFER()                                              \
+  do {                                                                 \
+    UCHAR_T *old_buffer = COMPILED_BUFFER_VAR;                         \
+    if (bufp->allocated == MAX_BUF_SIZE)                               \
+      return REG_ESIZE;                                                        \
+    bufp->allocated <<= 1;                                             \
+    if (bufp->allocated > MAX_BUF_SIZE)                                        \
+      bufp->allocated = MAX_BUF_SIZE;                                  \
+    bufp->buffer = (UCHAR_T *) REALLOC (COMPILED_BUFFER_VAR,           \
+                                               bufp->allocated);       \
+    if (COMPILED_BUFFER_VAR == NULL)                                   \
+      return REG_ESPACE;                                               \
+    /* If the buffer moved, move all the pointers into it.  */         \
+    if (old_buffer != COMPILED_BUFFER_VAR)                             \
+      {                                                                        \
+       int incr = COMPILED_BUFFER_VAR - 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)
+# endif /* WCHAR */
+
+# ifndef DEFINED_ONCE
+/* 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 unsigned 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 inner_group_offset;
+  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])
+
+# endif /* not DEFINED_ONCE */
+
+/* Set the bit for character C in a list.  */
+# ifndef DEFINED_ONCE
+#  define SET_LIST_BIT(c)                               \
+  (b[((unsigned char) (c)) / BYTEWIDTH]               \
+   |= 1 << (((unsigned char) c) % BYTEWIDTH))
+# endif /* DEFINED_ONCE */
+
+/* Get the next unsigned number in the uncompiled pattern.  */
+# define GET_UNSIGNED_NUMBER(num) \
+  {                                                                    \
+    while (p != pend)                                                  \
+      {                                                                        \
+       PATFETCH (c);                                                   \
+       if (c < '0' || c > '9')                                         \
+         break;                                                        \
+       if (num <= RE_DUP_MAX)                                          \
+         {                                                             \
+           if (num < 0)                                                \
+             num = 0;                                                  \
+           num = num * 10 + c - '0';                                   \
+         }                                                             \
+      }                                                                        \
+  }
+
+# ifndef DEFINED_ONCE
+#  if defined _LIBC || 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
+
+#   ifdef _LIBC
+#    define IS_CHAR_CLASS(string) __wctype (string)
+#   else
+#    define IS_CHAR_CLASS(string) wctype (string)
+#   endif
+#  else
+#   define CHAR_CLASS_MAX_LENGTH  6 /* Namely, `xdigit'.  */
+
+#   define IS_CHAR_CLASS(string)                                       \
+   (STREQ (string, "alpha") || STREQ (string, "upper")                 \
+    || STREQ (string, "lower") || STREQ (string, "digit")              \
+    || STREQ (string, "alnum") || STREQ (string, "xdigit")             \
+    || STREQ (string, "space") || STREQ (string, "print")              \
+    || STREQ (string, "punct") || STREQ (string, "graph")              \
+    || STREQ (string, "cntrl") || STREQ (string, "blank"))
+#  endif
+# endif /* DEFINED_ONCE */
+\f
+# 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 PREFIX(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.  */
+#  ifdef DEFINED_ONCE
+static int regs_allocated_size;
+
+static const char **     regstart, **     regend;
+static const char ** old_regstart, ** old_regend;
+static const char **best_regstart, **best_regend;
+static const char **reg_dummy;
+#  endif /* DEFINED_ONCE */
+
+static PREFIX(register_info_type) *PREFIX(reg_info);
+static PREFIX(register_info_type) *PREFIX(reg_info_dummy);
+
+/* Make the register vectors big enough for NUM_REGS registers,
+   but don't make them smaller.  */
+
+static void
+PREFIX(regex_grow_registers) (num_regs)
+     int num_regs;
+{
+  if (num_regs > regs_allocated_size)
+    {
+      RETALLOC_IF (regstart,    num_regs, const char *);
+      RETALLOC_IF (regend,      num_regs, const char *);
+      RETALLOC_IF (old_regstart, num_regs, const char *);
+      RETALLOC_IF (old_regend,  num_regs, const char *);
+      RETALLOC_IF (best_regstart, num_regs, const char *);
+      RETALLOC_IF (best_regend,         num_regs, const char *);
+      RETALLOC_IF (PREFIX(reg_info), num_regs, PREFIX(register_info_type));
+      RETALLOC_IF (reg_dummy,   num_regs, const char *);
+      RETALLOC_IF (PREFIX(reg_info_dummy), num_regs, PREFIX(register_info_type));
+
+      regs_allocated_size = num_regs;
+    }
+}
+
+# endif /* not MATCH_MAY_ALLOCATE */
+\f
+# ifndef DEFINED_ONCE
+static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
+                                                compile_stack,
+                                                regnum_t regnum));
+# endif /* not DEFINED_ONCE */
+
+/* `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' and `newline_anchor' fields are neither
+   examined nor set.  */
+
+/* Return, freeing storage we allocated.  */
+# ifdef WCHAR
+#  define FREE_STACK_RETURN(value)             \
+  return (free(pattern), free(mbs_offset), free(is_binary), free (compile_stack.stack), value)
+# else
+#  define FREE_STACK_RETURN(value)             \
+  return (free (compile_stack.stack), value)
+# endif /* WCHAR */
+
+static reg_errcode_t
+PREFIX(regex_compile) (ARG_PREFIX(pattern), ARG_PREFIX(size), syntax, bufp)
+     const char *ARG_PREFIX(pattern);
+     size_t ARG_PREFIX(size);
+     reg_syntax_t syntax;
+     struct re_pattern_buffer *bufp;
+{
+  /* We fetch characters from PATTERN here.  Even though PATTERN is
+     `char *' (i.e., signed), we declare these variables as unsigned, so
+     they can be reliably used as array indices.  */
+  register UCHAR_T c, c1;
+
+#ifdef WCHAR
+  /* A temporary space to keep wchar_t pattern and compiled pattern.  */
+  CHAR_T *pattern, *COMPILED_BUFFER_VAR;
+  size_t size;
+  /* offset buffer for optimization. See convert_mbs_to_wc.  */
+  int *mbs_offset = NULL;
+  /* It hold whether each wchar_t is binary data or not.  */
+  char *is_binary = NULL;
+  /* A flag whether exactn is handling binary data or not.  */
+  char is_exactn_bin = FALSE;
+#endif /* WCHAR */
+
+  /* A random temporary spot in PATTERN.  */
+  const CHAR_T *p1;
+
+  /* Points to the end of the buffer, where we should append.  */
+  register UCHAR_T *b;
+
+  /* Keeps track of unclosed groups.  */
+  compile_stack_type compile_stack;
+
+  /* Points to the current (ending) position in the pattern.  */
+#ifdef WCHAR
+  const CHAR_T *p;
+  const CHAR_T *pend;
+#else /* BYTE */
+  const CHAR_T *p = pattern;
+  const CHAR_T *pend = pattern + size;
+#endif /* WCHAR */
+
+  /* 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.  */
+  UCHAR_T *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.  */
+  UCHAR_T *laststart = 0;
+
+  /* Address of beginning of regexp, or inside of last group.  */
+  UCHAR_T *begalt;
+
+  /* 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.  */
+  UCHAR_T *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;
+
+#ifdef WCHAR
+  /* Initialize the wchar_t PATTERN and offset_buffer.  */
+  p = pend = pattern = TALLOC(csize + 1, CHAR_T);
+  mbs_offset = TALLOC(csize + 1, int);
+  is_binary = TALLOC(csize + 1, char);
+  if (pattern == NULL || mbs_offset == NULL || is_binary == NULL)
+    {
+      free(pattern);
+      free(mbs_offset);
+      free(is_binary);
+      return REG_ESPACE;
+    }
+  pattern[csize] = L'\0';      /* sentinel */
+  size = convert_mbs_to_wcs(pattern, cpattern, csize, mbs_offset, is_binary);
+  pend = p + size;
+  if (size < 0)
+    {
+      free(pattern);
+      free(mbs_offset);
+      free(is_binary);
+      return REG_BADPAT;
+    }
+#endif
+
+#ifdef DEBUG
+  DEBUG_PRINT1 ("\nCompiling pattern: ");
+  if (debug)
+    {
+      unsigned debug_count;
+
+      for (debug_count = 0; debug_count < size; debug_count++)
+        PUT_CHAR (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)
+    {
+#ifdef WCHAR
+      free(pattern);
+      free(mbs_offset);
+      free(is_binary);
+#endif
+      return REG_ESPACE;
+    }
+
+  compile_stack.size = INIT_COMPILE_STACK_SIZE;
+  compile_stack.avail = 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.  */
+#ifdef WCHAR
+         /* Free bufp->buffer and allocate an array for wchar_t pattern
+            buffer.  */
+          free(bufp->buffer);
+          COMPILED_BUFFER_VAR = TALLOC (INIT_BUF_SIZE/sizeof(UCHAR_T),
+                                       UCHAR_T);
+#else
+          RETALLOC (COMPILED_BUFFER_VAR, INIT_BUF_SIZE, UCHAR_T);
+#endif /* WCHAR */
+        }
+      else
+        { /* Caller did not allocate a buffer.  Do it for them.  */
+          COMPILED_BUFFER_VAR = TALLOC (INIT_BUF_SIZE / sizeof(UCHAR_T),
+                                       UCHAR_T);
+        }
+
+      if (!COMPILED_BUFFER_VAR) FREE_STACK_RETURN (REG_ESPACE);
+#ifdef WCHAR
+      bufp->buffer = (char*)COMPILED_BUFFER_VAR;
+#endif /* WCHAR */
+      bufp->allocated = INIT_BUF_SIZE;
+    }
+#ifdef WCHAR
+  else
+    COMPILED_BUFFER_VAR = (UCHAR_T*) bufp->buffer;
+#endif
+
+  begalt = b = COMPILED_BUFFER_VAR;
+
+  /* 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.  */
+                || PREFIX(at_begline_loc_p) (pattern, p, syntax))
+              BUF_PUSH (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.  */
+                || PREFIX(at_endline_loc_p) (p, pend, syntax))
+               BUF_PUSH (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;
+            }
+
+          {
+            /* Are we optimizing this jump?  */
+            boolean keep_string_p = false;
+
+            /* 1 means zero (many) matches is allowed.  */
+            char zero_times_ok = 0, many_times_ok = 0;
+
+            /* 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 (;;)
+              {
+                zero_times_ok |= c != '+';
+                many_times_ok |= c != '?';
+
+                if (p == pend)
+                  break;
+
+                PATFETCH (c);
+
+                if (c == '*'
+                    || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
+                  ;
+
+                else if (syntax & RE_BK_PLUS_QM  &&  c == '\\')
+                  {
+                    if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+
+                    PATFETCH (c1);
+                    if (!(c1 == '+' || c1 == '?'))
+                      {
+                        PATUNFETCH;
+                        PATUNFETCH;
+                        break;
+                      }
+
+                    c = c1;
+                  }
+                else
+                  {
+                    PATUNFETCH;
+                    break;
+                  }
+
+                /* If we get here, we found another repeat character.  */
+               }
+
+            /* Star, etc. applied to an empty pattern is equivalent
+               to an empty pattern.  */
+            if (!laststart)
+              break;
+
+            /* Now we know whether or not zero matches is allowed
+               and also whether or not two or more matches is allowed.  */
+            if (many_times_ok)
+              { /* More than one repetition is allowed, so put in at the
+                   end a backward relative jump from `b' to before the next
+                   jump we're going to put in below (which jumps from
+                   laststart to after this jump).
+
+                   But if we are at the `*' in the exact sequence `.*\n',
+                   insert an unconditional jump backwards to the .,
+                   instead of the beginning of the loop.  This way we only
+                   push a failure point once, instead of every time
+                   through the loop.  */
+                assert (p - 1 > pattern);
+
+                /* Allocate the space for the jump.  */
+                GET_BUFFER_SPACE (1 + OFFSET_ADDRESS_SIZE);
+
+                /* We know we are not at the first character of the pattern,
+                   because laststart was nonzero.  And we've already
+                   incremented `p', by the way, to be the character after
+                   the `*'.  Do we have to do something analogous here
+                   for null bytes, because of RE_DOT_NOT_NULL?  */
+                if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
+                   && zero_times_ok
+                    && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
+                    && !(syntax & RE_DOT_NEWLINE))
+                  { /* We have .*\n.  */
+                    STORE_JUMP (jump, b, laststart);
+                    keep_string_p = true;
+                  }
+                else
+                  /* Anything else.  */
+                  STORE_JUMP (maybe_pop_jump, b, laststart -
+                             (1 + OFFSET_ADDRESS_SIZE));
+
+                /* We've added more stuff to the buffer.  */
+                b += 1 + OFFSET_ADDRESS_SIZE;
+              }
+
+            /* On failure, jump from laststart to b + 3, which will be the
+               end of the buffer after this jump is inserted.  */
+           /* ifdef WCHAR, 'b + 1 + OFFSET_ADDRESS_SIZE' instead of
+              'b + 3'.  */
+            GET_BUFFER_SPACE (1 + OFFSET_ADDRESS_SIZE);
+            INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
+                                       : on_failure_jump,
+                         laststart, b + 1 + OFFSET_ADDRESS_SIZE);
+            pending_exact = 0;
+            b += 1 + OFFSET_ADDRESS_SIZE;
+
+            if (!zero_times_ok)
+              {
+                /* At least one repetition is required, so insert a
+                   `dummy_failure_jump' before the initial
+                   `on_failure_jump' instruction of the loop. This
+                   effects a skip over that instruction the first time
+                   we hit that loop.  */
+                GET_BUFFER_SPACE (1 + OFFSET_ADDRESS_SIZE);
+                INSERT_JUMP (dummy_failure_jump, laststart, laststart +
+                            2 + 2 * OFFSET_ADDRESS_SIZE);
+                b += 1 + OFFSET_ADDRESS_SIZE;
+              }
+            }
+         break;
+
+
+       case '.':
+          laststart = b;
+          BUF_PUSH (anychar);
+          break;
+
+
+        case '[':
+          {
+            boolean had_char_class = false;
+#ifdef WCHAR
+           CHAR_T range_start = 0xffffffff;
+#else
+           unsigned int range_start = 0xffffffff;
+#endif
+            if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+
+#ifdef WCHAR
+           /* We assume a charset(_not) structure as a wchar_t array.
+              charset[0] = (re_opcode_t) charset(_not)
+               charset[1] = l (= length of char_classes)
+               charset[2] = m (= length of collating_symbols)
+               charset[3] = n (= length of equivalence_classes)
+              charset[4] = o (= length of char_ranges)
+              charset[5] = p (= length of chars)
+
+               charset[6] = char_class (wctype_t)
+               charset[6+CHAR_CLASS_SIZE] = char_class (wctype_t)
+                         ...
+               charset[l+5]  = char_class (wctype_t)
+
+               charset[l+6]  = collating_symbol (wchar_t)
+                            ...
+               charset[l+m+5]  = collating_symbol (wchar_t)
+                                       ifdef _LIBC we use the index if
+                                       _NL_COLLATE_SYMB_EXTRAMB instead of
+                                       wchar_t string.
+
+               charset[l+m+6]  = equivalence_classes (wchar_t)
+                              ...
+               charset[l+m+n+5]  = equivalence_classes (wchar_t)
+                                       ifdef _LIBC we use the index in
+                                       _NL_COLLATE_WEIGHT instead of
+                                       wchar_t string.
+
+              charset[l+m+n+6] = range_start
+              charset[l+m+n+7] = range_end
+                              ...
+              charset[l+m+n+2o+4] = range_start
+              charset[l+m+n+2o+5] = range_end
+                                       ifdef _LIBC we use the value looked up
+                                       in _NL_COLLATE_COLLSEQ instead of
+                                       wchar_t character.
+
+              charset[l+m+n+2o+6] = char
+                                 ...
+              charset[l+m+n+2o+p+5] = char
+
+            */
+
+           /* We need at least 6 spaces: the opcode, the length of
+               char_classes, the length of collating_symbols, the length of
+               equivalence_classes, the length of char_ranges, the length of
+               chars.  */
+           GET_BUFFER_SPACE (6);
+
+           /* Save b as laststart. And We use laststart as the pointer
+              to the first element of the charset here.
+              In other words, laststart[i] indicates charset[i].  */
+            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++;
+
+            /* Push the length of char_classes, the length of
+               collating_symbols, the length of equivalence_classes, the
+               length of char_ranges and the length of chars.  */
+            BUF_PUSH_3 (0, 0, 0);
+            BUF_PUSH_2 (0, 0);
+
+            /* Remember the first position in the bracket expression.  */
+            p1 = p;
+
+            /* charset_not matches newline according to a syntax bit.  */
+            if ((re_opcode_t) b[-6] == charset_not
+                && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
+             {
+               BUF_PUSH('\n');
+               laststart[5]++; /* Update the length of characters  */
+             }
+
+            /* Read in characters and ranges, setting map bits.  */
+            for (;;)
+              {
+                if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+
+                PATFETCH (c);
+
+                /* \ might escape characters inside [...] and [^...].  */
+                if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
+                  {
+                    if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+
+                    PATFETCH (c1);
+                   BUF_PUSH(c1);
+                   laststart[5]++; /* Update the length of chars  */
+                   range_start = c1;
+                    continue;
+                  }
+
+                /* 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 == ']' && p != p1 + 1)
+                  break;
+
+                /* Look ahead to see if it's a range when the last thing
+                   was a character class.  */
+                if (had_char_class && c == '-' && *p != ']')
+                  FREE_STACK_RETURN (REG_ERANGE);
+
+                /* Look ahead to see if it's a range when the last thing
+                   was a character: if this is a hyphen not at the
+                   beginning or the end of a list, then it's the range
+                   operator.  */
+                if (c == '-'
+                    && !(p - 2 >= pattern && p[-2] == '[')
+                    && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
+                    && *p != ']')
+                  {
+                    reg_errcode_t ret;
+                   /* Allocate the space for range_start and range_end.  */
+                   GET_BUFFER_SPACE (2);
+                   /* Update the pointer to indicate end of buffer.  */
+                    b += 2;
+                    ret = wcs_compile_range (range_start, &p, pend, translate,
+                                         syntax, b, laststart);
+                    if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
+                    range_start = 0xffffffff;
+                  }
+                else if (p[0] == '-' && p[1] != ']')
+                  { /* This handles ranges made up of characters only.  */
+                    reg_errcode_t ret;
+
+                   /* Move past the `-'.  */
+                    PATFETCH (c1);
+                   /* Allocate the space for range_start and range_end.  */
+                   GET_BUFFER_SPACE (2);
+                   /* Update the pointer to indicate end of buffer.  */
+                    b += 2;
+                    ret = wcs_compile_range (c, &p, pend, translate, syntax, b,
+                                         laststart);
+                    if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
+                   range_start = 0xffffffff;
+                  }
+
+                /* See if we're at the beginning of a possible character
+                   class.  */
+                else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
+                  { /* Leave room for the null.  */
+                    char str[CHAR_CLASS_MAX_LENGTH + 1];
+
+                    PATFETCH (c);
+                    c1 = 0;
+
+                    /* 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 store them as character).  */
+                    if (c == ':' && *p == ']')
+                      {
+                       wctype_t wt;
+                       uintptr_t alignedp;
+
+                       /* Query the character class as wctype_t.  */
+                       wt = IS_CHAR_CLASS (str);
+                       if (wt == 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);
+
+                       /* Allocate the space for character class.  */
+                        GET_BUFFER_SPACE(CHAR_CLASS_SIZE);
+                       /* Update the pointer to indicate end of buffer.  */
+                        b += CHAR_CLASS_SIZE;
+                       /* Move data which follow character classes
+                           not to violate the data.  */
+                        insert_space(CHAR_CLASS_SIZE,
+                                    laststart + 6 + laststart[1],
+                                    b - 1);
+                       alignedp = ((uintptr_t)(laststart + 6 + laststart[1])
+                                   + __alignof__(wctype_t) - 1)
+                                   & ~(uintptr_t)(__alignof__(wctype_t) - 1);
+                       /* Store the character class.  */
+                        *((wctype_t*)alignedp) = wt;
+                        /* Update length of char_classes */
+                        laststart[1] += CHAR_CLASS_SIZE;
+
+                        had_char_class = true;
+                      }
+                    else
+                      {
+                        c1++;
+                        while (c1--)
+                          PATUNFETCH;
+                        BUF_PUSH ('[');
+                        BUF_PUSH (':');
+                        laststart[5] += 2; /* Update the length of characters  */
+                       range_start = ':';
+                        had_char_class = false;
+                      }
+                  }
+                else if (syntax & RE_CHAR_CLASSES && c == '[' && (*p == '='
+                                                         || *p == '.'))
+                 {
+                   CHAR_T str[128];    /* Should be large enough.  */
+                   CHAR_T delim = *p; /* '=' or '.'  */
+# ifdef _LIBC
+                   uint32_t nrules =
+                     _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+# endif
+                   PATFETCH (c);
+                   c1 = 0;
+
+                   /* If pattern is `[[=' or '[[.'.  */
+                   if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+
+                   for (;;)
+                     {
+                       PATFETCH (c);
+                       if ((c == delim && *p == ']') || p == pend)
+                         break;
+                       if (c1 < sizeof (str) - 1)
+                         str[c1++] = c;
+                       else
+                         /* This is in any case an invalid class name.  */
+                         str[0] = '\0';
+                      }
+                   str[c1] = '\0';
+
+                   if (c == delim && *p == ']' && str[0] != '\0')
+                     {
+                        unsigned int i, offset;
+                       /* If we have no collation data we use the default
+                          collation in which each character is in a class
+                          by itself.  It also means that ASCII is the
+                          character set and therefore we cannot have character
+                          with more than one byte in the multibyte
+                          representation.  */
+
+                        /* If not defined _LIBC, we push the name and
+                          `\0' for the sake of matching performance.  */
+                       int datasize = c1 + 1;
+
+# ifdef _LIBC
+                       int32_t idx = 0;
+                       if (nrules == 0)
+# endif
+                         {
+                           if (c1 != 1)
+                             FREE_STACK_RETURN (REG_ECOLLATE);
+                         }
+# ifdef _LIBC
+                       else
+                         {
+                           const int32_t *table;
+                           const int32_t *weights;
+                           const int32_t *extra;
+                           const int32_t *indirect;
+                           wint_t *cp;
+
+                           /* This #include defines a local function!  */
+#  include <locale/weightwc.h>
+
+                           if(delim == '=')
+                             {
+                               /* We push the index for equivalence class.  */
+                               cp = (wint_t*)str;
+
+                               table = (const int32_t *)
+                                 _NL_CURRENT (LC_COLLATE,
+                                              _NL_COLLATE_TABLEWC);
+                               weights = (const int32_t *)
+                                 _NL_CURRENT (LC_COLLATE,
+                                              _NL_COLLATE_WEIGHTWC);
+                               extra = (const int32_t *)
+                                 _NL_CURRENT (LC_COLLATE,
+                                              _NL_COLLATE_EXTRAWC);
+                               indirect = (const int32_t *)
+                                 _NL_CURRENT (LC_COLLATE,
+                                              _NL_COLLATE_INDIRECTWC);
+
+                               idx = findidx ((const wint_t**)&cp);
+                               if (idx == 0 || cp < (wint_t*) str + c1)
+                                 /* This is no valid character.  */
+                                 FREE_STACK_RETURN (REG_ECOLLATE);
+
+                               str[0] = (wchar_t)idx;
+                             }
+                           else /* delim == '.' */
+                             {
+                               /* We push collation sequence value
+                                  for collating symbol.  */
+                               int32_t table_size;
+                               const int32_t *symb_table;
+                               const unsigned char *extra;
+                               int32_t idx;
+                               int32_t elem;
+                               int32_t second;
+                               int32_t hash;
+                               char char_str[c1];
+
+                               /* We have to convert the name to a single-byte
+                                  string.  This is possible since the names
+                                  consist of ASCII characters and the internal
+                                  representation is UCS4.  */
+                               for (i = 0; i < c1; ++i)
+                                 char_str[i] = str[i];
+
+                               table_size =
+                                 _NL_CURRENT_WORD (LC_COLLATE,
+                                                   _NL_COLLATE_SYMB_HASH_SIZEMB);
+                               symb_table = (const int32_t *)
+                                 _NL_CURRENT (LC_COLLATE,
+                                              _NL_COLLATE_SYMB_TABLEMB);
+                               extra = (const unsigned char *)
+                                 _NL_CURRENT (LC_COLLATE,
+                                              _NL_COLLATE_SYMB_EXTRAMB);
+
+                               /* Locate the character in the hashing table.  */
+                               hash = elem_hash (char_str, c1);
+
+                               idx = 0;
+                               elem = hash % table_size;
+                               second = hash % (table_size - 2);
+                               while (symb_table[2 * elem] != 0)
+                                 {
+                                   /* First compare the hashing value.  */
+                                   if (symb_table[2 * elem] == hash
+                                       && c1 == extra[symb_table[2 * elem + 1]]
+                                       && memcmp (str,
+                                                  &extra[symb_table[2 * elem + 1]
+                                                        + 1], c1) == 0)
+                                     {
+                                       /* Yep, this is the entry.  */
+                                       idx = symb_table[2 * elem + 1];
+                                       idx += 1 + extra[idx];
+                                       break;
+                                     }
+
+                                   /* Next entry.  */
+                                   elem += second;
+                                 }
+
+                               if (symb_table[2 * elem] != 0)
+                                 {
+                                   /* Compute the index of the byte sequence
+                                      in the table.  */
+                                   idx += 1 + extra[idx];
+                                   /* Adjust for the alignment.  */
+                                   idx = (idx + 3) & ~4;
+
+                                   str[0] = (wchar_t) idx + 4;
+                                 }
+                               else if (symb_table[2 * elem] == 0 && c1 == 1)
+                                 {
+                                   /* No valid character.  Match it as a
+                                      single byte character.  */
+                                   had_char_class = false;
+                                   BUF_PUSH(str[0]);
+                                   /* Update the length of characters  */
+                                   laststart[5]++;
+                                   range_start = str[0];
+
+                                   /* Throw away the ] at the end of the
+                                      collating symbol.  */
+                                   PATFETCH (c);
+                                   /* exit from the switch block.  */
+                                   continue;
+                                 }
+                               else
+                                 FREE_STACK_RETURN (REG_ECOLLATE);
+                             }
+                           datasize = 1;
+                         }
+# endif
+                        /* Throw away the ] at the end of the equivalence
+                           class (or collating symbol).  */
+                        PATFETCH (c);
+
+                       /* Allocate the space for the equivalence class
+                          (or collating symbol) (and '\0' if needed).  */
+                        GET_BUFFER_SPACE(datasize);
+                       /* Update the pointer to indicate end of buffer.  */
+                        b += datasize;
+
+                       if (delim == '=')
+                         { /* equivalence class  */
+                           /* Calculate the offset of char_ranges,
+                              which is next to equivalence_classes.  */
+                           offset = laststart[1] + laststart[2]
+                             + laststart[3] +6;
+                           /* Insert space.  */
+                           insert_space(datasize, laststart + offset, b - 1);
+
+                           /* Write the equivalence_class and \0.  */
+                           for (i = 0 ; i < datasize ; i++)
+                             laststart[offset + i] = str[i];
+
+                           /* Update the length of equivalence_classes.  */
+                           laststart[3] += datasize;
+                           had_char_class = true;
+                         }
+                       else /* delim == '.' */
+                         { /* collating symbol  */
+                           /* Calculate the offset of the equivalence_classes,
+                              which is next to collating_symbols.  */
+                           offset = laststart[1] + laststart[2] + 6;
+                           /* Insert space and write the collationg_symbol
+                              and \0.  */
+                           insert_space(datasize, laststart + offset, b-1);
+                           for (i = 0 ; i < datasize ; i++)
+                             laststart[offset + i] = str[i];
+
+                           /* In re_match_2_internal if range_start < -1, we
+                              assume -range_start is the offset of the
+                              collating symbol which is specified as
+                              the character of the range start.  So we assign
+                              -(laststart[1] + laststart[2] + 6) to
+                              range_start.  */
+                           range_start = -(laststart[1] + laststart[2] + 6);
+                           /* Update the length of collating_symbol.  */
+                           laststart[2] += datasize;
+                           had_char_class = false;
+                         }
+                     }
+                    else
+                      {
+                        c1++;
+                        while (c1--)
+                          PATUNFETCH;
+                        BUF_PUSH ('[');
+                        BUF_PUSH (delim);
+                        laststart[5] += 2; /* Update the length of characters  */
+                       range_start = delim;
+                        had_char_class = false;
+                      }
+                 }
+                else
+                  {
+                    had_char_class = false;
+                   BUF_PUSH(c);
+                   laststart[5]++;  /* Update the length of characters  */
+                   range_start = c;
+                  }
+             }
+
+#else /* BYTE */
+            /* 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 (;;)
+              {
+                if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+
+                PATFETCH (c);
+
+                /* \ might escape characters inside [...] and [^...].  */
+                if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
+                  {
+                    if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);
+
+                    PATFETCH (c1);
+                    SET_LIST_BIT (c1);
+                   range_start = c1;
+                    continue;
+                  }
+
+                /* 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 == ']' && p != p1 + 1)
+                  break;
+
+                /* Look ahead to see if it's a range when the last thing
+                   was a character class.  */
+                if (had_char_class && c == '-' && *p != ']')
+                  FREE_STACK_RETURN (REG_ERANGE);
+
+                /* Look ahead to see if it's a range when the last thing
+                   was a character: if this is a hyphen not at the
+                   beginning or the end of a list, then it's the range
+                   operator.  */
+                if (c == '-'
+                    && !(p - 2 >= pattern && p[-2] == '[')
+                    && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
+                    && *p != ']')
+                  {
+                    reg_errcode_t ret
+                      = byte_compile_range (range_start, &p, pend, translate,
+                                           syntax, b);
+                    if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
+                   range_start = 0xffffffff;
+                  }
+
+                else if (p[0] == '-' && p[1] != ']')
+                  { /* This handles ranges made up of characters only.  */
+                    reg_errcode_t ret;
+
+                   /* Move past the `-'.  */
+                    PATFETCH (c1);
+
+                    ret = byte_compile_range (c, &p, pend, translate, syntax, b);
+                    if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
+                   range_start = 0xffffffff;
+                  }
+
+                /* See if we're at the beginning of a possible character
+                   class.  */
+
+                else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
+                  { /* Leave room for the null.  */
+                    char str[CHAR_CLASS_MAX_LENGTH + 1];
+
+                    PATFETCH (c);
+                    c1 = 0;
+
+                    /* 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 == ']')
+                      {
+# if defined _LIBC || WIDE_CHAR_SUPPORT
+                        boolean is_lower = STREQ (str, "lower");
+                        boolean is_upper = STREQ (str, "upper");
+                       wctype_t wt;
+                        int ch;
+
+                       wt = IS_CHAR_CLASS (str);
+                       if (wt == 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);
+
+                        for (ch = 0; ch < 1 << BYTEWIDTH; ++ch)
+                         {
+#  ifdef _LIBC
+                           if (__iswctype (__btowc (ch), wt))
+                             SET_LIST_BIT (ch);
+#  else
+                           if (iswctype (btowc (ch), wt))
+                             SET_LIST_BIT (ch);
+#  endif
+
+                           if (translate && (is_upper || is_lower)
+                               && (ISUPPER (ch) || ISLOWER (ch)))
+                             SET_LIST_BIT (ch);
+                         }
+
+                        had_char_class = true;
+# else
+                        int ch;
+                        boolean is_alnum = STREQ (str, "alnum");
+                        boolean is_alpha = STREQ (str, "alpha");
+                        boolean is_blank = STREQ (str, "blank");
+                        boolean is_cntrl = STREQ (str, "cntrl");
+                        boolean is_digit = STREQ (str, "digit");
+                        boolean is_graph = STREQ (str, "graph");
+                        boolean is_lower = STREQ (str, "lower");
+                        boolean is_print = STREQ (str, "print");
+                        boolean is_punct = STREQ (str, "punct");
+                        boolean is_space = STREQ (str, "space");
+                        boolean is_upper = STREQ (str, "upper");
+                        boolean is_xdigit = STREQ (str, "xdigit");
+
+                        if (!IS_CHAR_CLASS (str))
+                         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);
+
+                        for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
+                          {
+                           /* This was split into 3 if's to
+                              avoid an arbitrary limit in some compiler.  */
+                            if (   (is_alnum  && ISALNUM (ch))
+                                || (is_alpha  && ISALPHA (ch))
+                                || (is_blank  && ISBLANK (ch))
+                                || (is_cntrl  && ISCNTRL (ch)))
+                             SET_LIST_BIT (ch);
+                           if (   (is_digit  && ISDIGIT (ch))
+                                || (is_graph  && ISGRAPH (ch))
+                                || (is_lower  && ISLOWER (ch))
+                                || (is_print  && ISPRINT (ch)))
+                             SET_LIST_BIT (ch);
+                           if (   (is_punct  && ISPUNCT (ch))
+                                || (is_space  && ISSPACE (ch))
+                                || (is_upper  && ISUPPER (ch))
+                                || (is_xdigit && ISXDIGIT (ch)))
+                             SET_LIST_BIT (ch);
+                           if (   translate && (is_upper || is_lower)
+                               && (ISUPPER (ch) || ISLOWER (ch)))
+                             SET_LIST_BIT (ch);
+                          }
+                        had_char_class = true;
+# endif        /* libc || wctype.h */
+                      }
+                    else
+                      {
+                        c1++;
+                        while (c1--)
+                          PATUNFETCH;
+                        SET_LIST_BIT ('[');
+                        SET_LIST_BIT (':');
+                       range_start = ':';
+                        had_char_class = false;
+                      }
+                  }
+                else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == '=')
+                 {
+                   unsigned char str[MB_LEN_MAX + 1];
+# ifdef _LIBC
+                   uint32_t nrules =
+                     _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+# endif
+
+                   PATFETCH (c);
+                   c1 = 0;
+
+                   /* If pattern is `[[='.  */
+                   if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+
+                   for (;;)
+                     {
+                       PATFETCH (c);
+                       if ((c == '=' && *p == ']') || p == pend)
+                         break;
+                       if (c1 < MB_LEN_MAX)
+                         str[c1++] = c;
+                       else
+                         /* This is in any case an invalid class name.  */
+                         str[0] = '\0';
+                      }
+                   str[c1] = '\0';
+
+                   if (c == '=' && *p == ']' && str[0] != '\0')
+                     {
+                       /* If we have no collation data we use the default
+                          collation in which each character is in a class
+                          by itself.  It also means that ASCII is the
+                          character set and therefore we cannot have character
+                          with more than one byte in the multibyte
+                          representation.  */
+# ifdef _LIBC
+                       if (nrules == 0)
+# endif
+                         {
+                           if (c1 != 1)
+                             FREE_STACK_RETURN (REG_ECOLLATE);
+
+                           /* Throw away the ] at the end of the equivalence
+                              class.  */
+                           PATFETCH (c);
+
+                           /* Set the bit for the character.  */
+                           SET_LIST_BIT (str[0]);
+                         }
+# ifdef _LIBC
+                       else
+                         {
+                           /* Try to match the byte sequence in `str' against
+                              those known to the collate implementation.
+                              First find out whether the bytes in `str' are
+                              actually from exactly one character.  */
+                           const int32_t *table;
+                           const unsigned char *weights;
+                           const unsigned char *extra;
+                           const int32_t *indirect;
+                           int32_t idx;
+                           const unsigned char *cp = str;
+                           int ch;
+
+                           /* This #include defines a local function!  */
+#  include <locale/weight.h>
+
+                           table = (const int32_t *)
+                             _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+                           weights = (const unsigned char *)
+                             _NL_CURRENT (LC_COLLATE, _NL_COLLATE_WEIGHTMB);
+                           extra = (const unsigned char *)
+                             _NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAMB);
+                           indirect = (const int32_t *)
+                             _NL_CURRENT (LC_COLLATE, _NL_COLLATE_INDIRECTMB);
+
+                           idx = findidx (&cp);
+                           if (idx == 0 || cp < str + c1)
+                             /* This is no valid character.  */
+                             FREE_STACK_RETURN (REG_ECOLLATE);
+
+                           /* Throw away the ] at the end of the equivalence
+                              class.  */
+                           PATFETCH (c);
+
+                           /* Now we have to go throught the whole table
+                              and find all characters which have the same
+                              first level weight.
+
+                              XXX Note that this is not entirely correct.
+                              we would have to match multibyte sequences
+                              but this is not possible with the current
+                              implementation.  */
+                           for (ch = 1; ch < 256; ++ch)
+                             /* XXX This test would have to be changed if we
+                                would allow matching multibyte sequences.  */
+                             if (table[ch] > 0)
+                               {
+                                 int32_t idx2 = table[ch];
+                                 size_t len = weights[idx2];
+
+                                 /* Test whether the lenghts match.  */
+                                 if (weights[idx] == len)
+                                   {
+                                     /* They do.  New compare the bytes of
+                                        the weight.  */
+                                     size_t cnt = 0;
+
+                                     while (cnt < len
+                                            && (weights[idx + 1 + cnt]
+                                                == weights[idx2 + 1 + cnt]))
+                                       ++cnt;
+
+                                     if (cnt == len)
+                                       /* They match.  Mark the character as
+                                          acceptable.  */
+                                       SET_LIST_BIT (ch);
+                                   }
+                               }
+                         }
+# endif
+                       had_char_class = true;
+                     }
+                    else
+                      {
+                        c1++;
+                        while (c1--)
+                          PATUNFETCH;
+                        SET_LIST_BIT ('[');
+                        SET_LIST_BIT ('=');
+                       range_start = '=';
+                        had_char_class = false;
+                      }
+                 }
+                else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == '.')
+                 {
+                   unsigned char str[128];     /* Should be large enough.  */
+# ifdef _LIBC
+                   uint32_t nrules =
+                     _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+# endif
+
+                   PATFETCH (c);
+                   c1 = 0;
+
+                   /* If pattern is `[[.'.  */
+                   if (p == pend) FREE_STACK_RETURN (REG_EBRACK);
+
+                   for (;;)
+                     {
+                       PATFETCH (c);
+                       if ((c == '.' && *p == ']') || p == pend)
+                         break;
+                       if (c1 < sizeof (str))
+                         str[c1++] = c;
+                       else
+                         /* This is in any case an invalid class name.  */
+                         str[0] = '\0';
+                      }
+                   str[c1] = '\0';
+
+                   if (c == '.' && *p == ']' && str[0] != '\0')
+                     {
+                       /* If we have no collation data we use the default
+                          collation in which each character is the name
+                          for its own class which contains only the one
+                          character.  It also means that ASCII is the
+                          character set and therefore we cannot have character
+                          with more than one byte in the multibyte
+                          representation.  */
+# ifdef _LIBC
+                       if (nrules == 0)
+# endif
+                         {
+                           if (c1 != 1)
+                             FREE_STACK_RETURN (REG_ECOLLATE);
+
+                           /* Throw away the ] at the end of the equivalence
+                              class.  */
+                           PATFETCH (c);
+
+                           /* Set the bit for the character.  */
+                           SET_LIST_BIT (str[0]);
+                           range_start = ((const unsigned char *) str)[0];
+                         }
+# ifdef _LIBC
+                       else
+                         {
+                           /* Try to match the byte sequence in `str' against
+                              those known to the collate implementation.
+                              First find out whether the bytes in `str' are
+                              actually from exactly one character.  */
+                           int32_t table_size;
+                           const int32_t *symb_table;
+                           const unsigned char *extra;
+                           int32_t idx;
+                           int32_t elem;
+                           int32_t second;
+                           int32_t hash;
+
+                           table_size =
+                             _NL_CURRENT_WORD (LC_COLLATE,
+                                               _NL_COLLATE_SYMB_HASH_SIZEMB);
+                           symb_table = (const int32_t *)
+                             _NL_CURRENT (LC_COLLATE,
+                                          _NL_COLLATE_SYMB_TABLEMB);
+                           extra = (const unsigned char *)
+                             _NL_CURRENT (LC_COLLATE,
+                                          _NL_COLLATE_SYMB_EXTRAMB);
+
+                           /* Locate the character in the hashing table.  */
+                           hash = elem_hash (str, c1);
+
+                           idx = 0;
+                           elem = hash % table_size;
+                           second = hash % (table_size - 2);
+                           while (symb_table[2 * elem] != 0)
+                             {
+                               /* First compare the hashing value.  */
+                               if (symb_table[2 * elem] == hash
+                                   && c1 == extra[symb_table[2 * elem + 1]]
+                                   && memcmp (str,
+                                              &extra[symb_table[2 * elem + 1]
+                                                    + 1],
+                                              c1) == 0)
+                                 {
+                                   /* Yep, this is the entry.  */
+                                   idx = symb_table[2 * elem + 1];
+                                   idx += 1 + extra[idx];
+                                   break;
+                                 }
+
+                               /* Next entry.  */
+                               elem += second;
+                             }
+
+                           if (symb_table[2 * elem] == 0)
+                             /* This is no valid character.  */
+                             FREE_STACK_RETURN (REG_ECOLLATE);
+
+                           /* Throw away the ] at the end of the equivalence
+                              class.  */
+                           PATFETCH (c);
+
+                           /* Now add the multibyte character(s) we found
+                              to the accept list.
+
+                              XXX Note that this is not entirely correct.
+                              we would have to match multibyte sequences
+                              but this is not possible with the current
+                              implementation.  Also, we have to match
+                              collating symbols, which expand to more than
+                              one file, as a whole and not allow the
+                              individual bytes.  */
+                           c1 = extra[idx++];
+                           if (c1 == 1)
+                             range_start = extra[idx];
+                           while (c1-- > 0)
+                             {
+                               SET_LIST_BIT (extra[idx]);
+                               ++idx;
+                             }
+                         }
+# endif
+                       had_char_class = false;
+                     }
+                    else
+                      {
+                        c1++;
+                        while (c1--)
+                          PATUNFETCH;
+                        SET_LIST_BIT ('[');
+                        SET_LIST_BIT ('.');
+                       range_start = '.';
+                        had_char_class = false;
+                      }
+                 }
+                else
+                  {
+                    had_char_class = false;
+                    SET_LIST_BIT (c);
+                   range_start = c;
+                  }
+              }
+
+            /* 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];
+#endif /* WCHAR */
+          }
+          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_RAW (c);
+
+          switch (c)
+            {
+            case '(':
+              if (syntax & RE_NO_BK_PARENS)
+                goto normal_backslash;
+
+            handle_open:
+              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 - COMPILED_BUFFER_VAR;
+              COMPILE_STACK_TOP.fixup_alt_jump
+                = fixup_alt_jump ? fixup_alt_jump - COMPILED_BUFFER_VAR + 1 : 0;
+              COMPILE_STACK_TOP.laststart_offset = b - COMPILED_BUFFER_VAR;
+              COMPILE_STACK_TOP.regnum = regnum;
+
+              /* We will eventually replace the 0 with the number of
+                 groups inner to this one.  But do not push a
+                 start_memory for groups beyond the last one we can
+                 represent in the compiled pattern.  */
+              if (regnum <= MAX_REGNUM)
+                {
+                  COMPILE_STACK_TOP.inner_group_offset = b
+                   - COMPILED_BUFFER_VAR + 2;
+                  BUF_PUSH_3 (start_memory, regnum, 0);
+                }
+
+              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:
+              if (fixup_alt_jump)
+                { /* Push a dummy failure point at the end of the
+                     alternative for a possible future
+                     `pop_failure_jump' to pop.  See comments at
+                     `push_dummy_failure' in `re_match_2'.  */
+                  BUF_PUSH (push_dummy_failure);
+
+                  /* We allocated space for this jump when we assigned
+                     to `fixup_alt_jump', in the `handle_alt' case below.  */
+                  STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
+                }
+
+              /* 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 = COMPILED_BUFFER_VAR + COMPILE_STACK_TOP.begalt_offset;
+                fixup_alt_jump
+                  = COMPILE_STACK_TOP.fixup_alt_jump
+                    ? COMPILED_BUFFER_VAR + COMPILE_STACK_TOP.fixup_alt_jump - 1
+                    : 0;
+                laststart = COMPILED_BUFFER_VAR + 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)
+                  {
+                   UCHAR_T *inner_group_loc
+                      = COMPILED_BUFFER_VAR + COMPILE_STACK_TOP.inner_group_offset;
+
+                    *inner_group_loc = regnum - this_group_regnum;
+                    BUF_PUSH_3 (stop_memory, this_group_regnum,
+                                regnum - 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 (1 + OFFSET_ADDRESS_SIZE);
+              INSERT_JUMP (on_failure_jump, begalt,
+                          b + 2 + 2 * OFFSET_ADDRESS_SIZE);
+              pending_exact = 0;
+              b += 1 + OFFSET_ADDRESS_SIZE;
+
+              /* 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'.  */
+
+              if (fixup_alt_jump)
+                STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
+
+              /* 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 (1 + OFFSET_ADDRESS_SIZE);
+              b += 1 + OFFSET_ADDRESS_SIZE;
+
+              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 = -1, upper_bound = -1;
+
+               /* Place in the uncompiled pattern (i.e., just after
+                  the '{') to go back to if the interval is invalid.  */
+               const CHAR_T *beg_interval = p;
+
+                if (p == pend)
+                 goto invalid_interval;
+
+                GET_UNSIGNED_NUMBER (lower_bound);
+
+                if (c == ',')
+                  {
+                    GET_UNSIGNED_NUMBER (upper_bound);
+                   if (upper_bound < 0)
+                     upper_bound = RE_DUP_MAX;
+                  }
+                else
+                  /* Interval such as `{1}' => match exactly once. */
+                  upper_bound = lower_bound;
+
+                if (! (0 <= lower_bound && lower_bound <= upper_bound))
+                 goto invalid_interval;
+
+                if (!(syntax & RE_NO_BK_BRACES))
+                  {
+                   if (c != '\\' || p == pend)
+                     goto invalid_interval;
+                    PATFETCH (c);
+                  }
+
+                if (c != '}')
+                 goto invalid_interval;
+
+                /* If it's invalid to have no preceding re.  */
+                if (!laststart)
+                  {
+                   if (syntax & RE_CONTEXT_INVALID_OPS
+                       && !(syntax & RE_INVALID_INTERVAL_ORD))
+                      FREE_STACK_RETURN (REG_BADRPT);
+                    else if (syntax & RE_CONTEXT_INDEP_OPS)
+                      laststart = b;
+                    else
+                      goto unfetch_interval;
+                  }
+
+                /* We just parsed a valid interval.  */
+
+                if (RE_DUP_MAX < upper_bound)
+                 FREE_STACK_RETURN (REG_BADBR);
+
+                /* If the upper bound is zero, don't want to succeed at
+                   all; jump from `laststart' to `b + 3', which will be
+                  the end of the buffer after we insert the jump.  */
+               /* ifdef WCHAR, 'b + 1 + OFFSET_ADDRESS_SIZE'
+                  instead of 'b + 3'.  */
+                 if (upper_bound == 0)
+                   {
+                     GET_BUFFER_SPACE (1 + OFFSET_ADDRESS_SIZE);
+                     INSERT_JUMP (jump, laststart, b + 1
+                                 + OFFSET_ADDRESS_SIZE);
+                     b += 1 + OFFSET_ADDRESS_SIZE;
+                   }
+
+                 /* 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 nbytes = 2 + 4 * OFFSET_ADDRESS_SIZE +
+                      (upper_bound > 1) * (2 + 4 * OFFSET_ADDRESS_SIZE);
+
+                     GET_BUFFER_SPACE (nbytes);
+
+                     /* 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 + 1 + 2 * OFFSET_ADDRESS_SIZE
+                                  + (upper_bound > 1) * (1 + 2 * OFFSET_ADDRESS_SIZE)
+                                  , lower_bound);
+                     b += 1 + 2 * OFFSET_ADDRESS_SIZE;
+
+                     /* 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'.  */
+                    /* ifdef WCHAR, The '1+2*OFFSET_ADDRESS_SIZE'
+                       is the 'set_number_at', plus '1+OFFSET_ADDRESS_SIZE'
+                       of the following `succeed_n'.  */
+                     PREFIX(insert_op2) (set_number_at, laststart, 1
+                                + 2 * OFFSET_ADDRESS_SIZE, lower_bound, b);
+                     b += 1 + 2 * OFFSET_ADDRESS_SIZE;
+
+                     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
+                                     + 2 * OFFSET_ADDRESS_SIZE + 1,
+                                      upper_bound - 1);
+                         b += 1 + 2 * OFFSET_ADDRESS_SIZE;
+
+                         /* 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.  */
+                         PREFIX(insert_op2) (set_number_at, laststart,
+                                            b - laststart,
+                                            upper_bound - 1, b);
+                         b += 1 + 2 * OFFSET_ADDRESS_SIZE;
+                       }
+                   }
+                pending_exact = 0;
+               break;
+
+             invalid_interval:
+               if (!(syntax & RE_INVALID_INTERVAL_ORD))
+                 FREE_STACK_RETURN (p == pend ? REG_EBRACE : REG_BADBR);
+             unfetch_interval:
+               /* Match the characters as literals.  */
+               p = beg_interval;
+               c = '{';
+               if (syntax & RE_NO_BK_BRACES)
+                 goto normal_char;
+               else
+                 goto normal_backslash;
+             }
+
+#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;
+#endif /* emacs */
+
+
+            case 'w':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+              laststart = b;
+              BUF_PUSH (wordchar);
+              break;
+
+
+            case 'W':
+             if (syntax & RE_NO_GNU_OPS)
+               goto normal_char;
+              laststart = b;
+              BUF_PUSH (notwordchar);
+              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':
+              if (syntax & RE_NO_BK_REFS)
+                goto normal_char;
+
+              c1 = c - '0';
+
+              if (c1 > regnum)
+                FREE_STACK_RETURN (REG_ESUBREG);
+
+              /* Can't back reference to a subexpression if inside of it.  */
+              if (group_in_compile_stack (compile_stack, (regnum_t) c1))
+                goto normal_char;
+
+              laststart = b;
+              BUF_PUSH_2 (duplicate, c1);
+              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.  */
+              c = TRANSLATE (c);
+              goto normal_char;
+            }
+          break;
+
+
+       default:
+        /* Expects the character in `c'.  */
+       normal_char:
+             /* If no exactn currently being built.  */
+          if (!pending_exact
+#ifdef WCHAR
+             /* If last exactn handle binary(or character) and
+                new exactn handle character(or binary).  */
+             || is_exactn_bin != is_binary[p - 1 - pattern]
+#endif /* WCHAR */
+
+              /* 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) - 1
+
+              /* If followed by a repetition operator.  */
+              || *p == '*' || *p == '^'
+             || ((syntax & RE_BK_PLUS_QM)
+                 ? *p == '\\' && (p[1] == '+' || p[1] == '?')
+                 : (*p == '+' || *p == '?'))
+             || ((syntax & RE_INTERVALS)
+                  && ((syntax & RE_NO_BK_BRACES)
+                     ? *p == '{'
+                      : (p[0] == '\\' && p[1] == '{'))))
+           {
+             /* Start building a new exactn.  */
+
+              laststart = b;
+
+#ifdef WCHAR
+             /* Is this exactn binary data or character? */
+             is_exactn_bin = is_binary[p - 1 - pattern];
+             if (is_exactn_bin)
+                 BUF_PUSH_2 (exactn_bin, 0);
+             else
+                 BUF_PUSH_2 (exactn, 0);
+#else
+             BUF_PUSH_2 (exactn, 0);
+#endif /* WCHAR */
+             pending_exact = b - 1;
+            }
+
+         BUF_PUSH (c);
+          (*pending_exact)++;
+         break;
+        } /* switch (c) */
+    } /* while p != pend */
+
+
+  /* Through the pattern now.  */
+
+  if (fixup_alt_jump)
+    STORE_JUMP (jump_past_alt, fixup_alt_jump, b);
+
+  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);
+
+#ifdef WCHAR
+  free (pattern);
+  free (mbs_offset);
+  free (is_binary);
+#endif
+  free (compile_stack.stack);
+
+  /* We have succeeded; set the length of the buffer.  */
+#ifdef WCHAR
+  bufp->used = (uintptr_t) b - (uintptr_t) COMPILED_BUFFER_VAR;
+#else
+  bufp->used = b - bufp->buffer;
+#endif
+
+#ifdef DEBUG
+  if (debug)
+    {
+      DEBUG_PRINT1 ("\nCompiled pattern: \n");
+      PREFIX(print_compiled_pattern) (bufp);
+    }
+#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;
+
+    /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
+       is strictly greater than re_max_failures, the largest possible stack
+       is 2 * re_max_failures failure points.  */
+    if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
+      {
+       fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);
+
+# ifdef emacs
+       if (! fail_stack.stack)
+         fail_stack.stack
+           = (PREFIX(fail_stack_elt_t) *) xmalloc (fail_stack.size
+                                   * sizeof (PREFIX(fail_stack_elt_t)));
+       else
+         fail_stack.stack
+           = (PREFIX(fail_stack_elt_t) *) xrealloc (fail_stack.stack,
+                                    (fail_stack.size
+                                     * sizeof (PREFIX(fail_stack_elt_t))));
+# else /* not emacs */
+       if (! fail_stack.stack)
+         fail_stack.stack
+           = (PREFIX(fail_stack_elt_t) *) malloc (fail_stack.size
+                                  * sizeof (PREFIX(fail_stack_elt_t)));
+       else
+         fail_stack.stack
+           = (PREFIX(fail_stack_elt_t) *) realloc (fail_stack.stack,
+                                           (fail_stack.size
+                                    * sizeof (PREFIX(fail_stack_elt_t))));
+# endif /* not emacs */
+      }
+
+   PREFIX(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.  */
+/* ifdef WCHAR, integer parameter is 1 wchar_t.  */
+
+static void
+PREFIX(store_op1) (op, loc, arg)
+    re_opcode_t op;
+    UCHAR_T *loc;
+    int arg;
+{
+  *loc = (UCHAR_T) op;
+  STORE_NUMBER (loc + 1, arg);
+}
+
+
+/* Like `store_op1', but for two two-byte parameters ARG1 and ARG2.  */
+/* ifdef WCHAR, integer parameter is 1 wchar_t.  */
+
+static void
+PREFIX(store_op2) (op, loc, arg1, arg2)
+    re_opcode_t op;
+    UCHAR_T *loc;
+    int arg1, arg2;
+{
+  *loc = (UCHAR_T) op;
+  STORE_NUMBER (loc + 1, arg1);
+  STORE_NUMBER (loc + 1 + OFFSET_ADDRESS_SIZE, 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.  */
+/* ifdef WCHAR, integer parameter is 1 wchar_t.  */
+
+static void
+PREFIX(insert_op1) (op, loc, arg, end)
+    re_opcode_t op;
+    UCHAR_T *loc;
+    int arg;
+    UCHAR_T *end;
+{
+  register UCHAR_T *pfrom = end;
+  register UCHAR_T *pto = end + 1 + OFFSET_ADDRESS_SIZE;
+
+  while (pfrom != loc)
+    *--pto = *--pfrom;
+
+  PREFIX(store_op1) (op, loc, arg);
+}
+
+
+/* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2.  */
+/* ifdef WCHAR, integer parameter is 1 wchar_t.  */
+
+static void
+PREFIX(insert_op2) (op, loc, arg1, arg2, end)
+    re_opcode_t op;
+    UCHAR_T *loc;
+    int arg1, arg2;
+    UCHAR_T *end;
+{
+  register UCHAR_T *pfrom = end;
+  register UCHAR_T *pto = end + 1 + 2 * OFFSET_ADDRESS_SIZE;
+
+  while (pfrom != loc)
+    *--pto = *--pfrom;
+
+  PREFIX(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
+PREFIX(at_begline_loc_p) (pattern, p, syntax)
+    const CHAR_T *pattern, *p;
+    reg_syntax_t syntax;
+{
+  const CHAR_T *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));
+}
+
+
+/* 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
+PREFIX(at_endline_loc_p) (p, pend, syntax)
+    const CHAR_T *p, *pend;
+    reg_syntax_t syntax;
+{
+  const CHAR_T *next = p;
+  boolean next_backslash = *next == '\\';
+  const CHAR_T *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 == '|');
+}
+
+#else /* not INSIDE_RECURSION */
+
+/* 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;
+}
+#endif /* not INSIDE_RECURSION */
+
+#ifdef INSIDE_RECURSION
+
+#ifdef WCHAR
+/* This insert space, which size is "num", into the pattern at "loc".
+   "end" must point the end of the allocated buffer.  */
+static void
+insert_space (num, loc, end)
+     int num;
+     CHAR_T *loc;
+     CHAR_T *end;
+{
+  register CHAR_T *pto = end;
+  register CHAR_T *pfrom = end - num;
+
+  while (pfrom >= loc)
+    *pto-- = *pfrom--;
+}
+#endif /* WCHAR */
+
+#ifdef WCHAR
+static reg_errcode_t
+wcs_compile_range (range_start_char, p_ptr, pend, translate, syntax, b,
+                  char_set)
+     CHAR_T range_start_char;
+     const CHAR_T **p_ptr, *pend;
+     CHAR_T *char_set, *b;
+     RE_TRANSLATE_TYPE translate;
+     reg_syntax_t syntax;
+{
+  const CHAR_T *p = *p_ptr;
+  CHAR_T range_start, range_end;
+  reg_errcode_t ret;
+# ifdef _LIBC
+  uint32_t nrules;
+  uint32_t start_val, end_val;
+# endif
+  if (p == pend)
+    return REG_ERANGE;
+
+# ifdef _LIBC
+  nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules != 0)
+    {
+      const char *collseq = (const char *) _NL_CURRENT(LC_COLLATE,
+                                                      _NL_COLLATE_COLLSEQWC);
+      const unsigned char *extra = (const unsigned char *)
+       _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+
+      if (range_start_char < -1)
+       {
+         /* range_start is a collating symbol.  */
+         int32_t *wextra;
+         /* Retreive the index and get collation sequence value.  */
+         wextra = (int32_t*)(extra + char_set[-range_start_char]);
+         start_val = wextra[1 + *wextra];
+       }
+      else
+       start_val = collseq_table_lookup(collseq, TRANSLATE(range_start_char));
+
+      end_val = collseq_table_lookup (collseq, TRANSLATE (p[0]));
+
+      /* Report an error if the range is empty and the syntax prohibits
+        this.  */
+      ret = ((syntax & RE_NO_EMPTY_RANGES)
+            && (start_val > end_val))? REG_ERANGE : REG_NOERROR;
+
+      /* Insert space to the end of the char_ranges.  */
+      insert_space(2, b - char_set[5] - 2, b - 1);
+      *(b - char_set[5] - 2) = (wchar_t)start_val;
+      *(b - char_set[5] - 1) = (wchar_t)end_val;
+      char_set[4]++; /* ranges_index */
+    }
+  else
+# endif
+    {
+      range_start = (range_start_char >= 0)? TRANSLATE (range_start_char):
+       range_start_char;
+      range_end = TRANSLATE (p[0]);
+      /* Report an error if the range is empty and the syntax prohibits
+        this.  */
+      ret = ((syntax & RE_NO_EMPTY_RANGES)
+            && (range_start > range_end))? REG_ERANGE : REG_NOERROR;
+
+      /* Insert space to the end of the char_ranges.  */
+      insert_space(2, b - char_set[5] - 2, b - 1);
+      *(b - char_set[5] - 2) = range_start;
+      *(b - char_set[5] - 1) = range_end;
+      char_set[4]++; /* ranges_index */
+    }
+  /* Have to increment the pointer into the pattern string, so the
+     caller isn't still at the ending character.  */
+  (*p_ptr)++;
+
+  return ret;
+}
+#else /* BYTE */
+/* Read the ending character of a range (in a bracket expression) from the
+   uncompiled pattern *P_PTR (which ends at PEND).  We assume the
+   starting character is in `P[-2]'.  (`P[-1]' is the character `-'.)
+   Then we set the translation of all bits between the starting and
+   ending characters (inclusive) in the compiled pattern B.
+
+   Return an error code.
+
+   We use these short variable names so we can use the same macros as
+   `regex_compile' itself.  */
+
+static reg_errcode_t
+byte_compile_range (range_start_char, p_ptr, pend, translate, syntax, b)
+     unsigned int range_start_char;
+     const char **p_ptr, *pend;
+     RE_TRANSLATE_TYPE translate;
+     reg_syntax_t syntax;
+     unsigned char *b;
+{
+  unsigned this_char;
+  const char *p = *p_ptr;
+  reg_errcode_t ret;
+# if _LIBC
+  const unsigned char *collseq;
+  unsigned int start_colseq;
+  unsigned int end_colseq;
+# else
+  unsigned end_char;
+# endif
+
+  if (p == pend)
+    return REG_ERANGE;
+
+  /* Have to increment the pointer into the pattern string, so the
+     caller isn't still at the ending character.  */
+  (*p_ptr)++;
+
+  /* Report an error if the range is empty and the syntax prohibits this.  */
+  ret = syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;
+
+# if _LIBC
+  collseq = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+                                                _NL_COLLATE_COLLSEQMB);
+
+  start_colseq = collseq[(unsigned char) TRANSLATE (range_start_char)];
+  end_colseq = collseq[(unsigned char) TRANSLATE (p[0])];
+  for (this_char = 0; this_char <= (unsigned char) -1; ++this_char)
+    {
+      unsigned int this_colseq = collseq[(unsigned char) TRANSLATE (this_char)];
+
+      if (start_colseq <= this_colseq && this_colseq <= end_colseq)
+       {
+         SET_LIST_BIT (TRANSLATE (this_char));
+         ret = REG_NOERROR;
+       }
+    }
+# else
+  /* Here we see why `this_char' has to be larger than an `unsigned
+     char' -- we would otherwise go into an infinite loop, since all
+     characters <= 0xff.  */
+  range_start_char = TRANSLATE (range_start_char);
+  /* TRANSLATE(p[0]) is casted to char (not unsigned char) in TRANSLATE,
+     and some compilers cast it to int implicitly, so following for_loop
+     may fall to (almost) infinite loop.
+     e.g. If translate[p[0]] = 0xff, end_char may equals to 0xffffffff.
+     To avoid this, we cast p[0] to unsigned int and truncate it.  */
+  end_char = ((unsigned)TRANSLATE(p[0]) & ((1 << BYTEWIDTH) - 1));
+
+  for (this_char = range_start_char; this_char <= end_char; ++this_char)
+    {
+      SET_LIST_BIT (TRANSLATE (this_char));
+      ret = REG_NOERROR;
+    }
+# endif
+
+  return ret;
+}
+#endif /* WCHAR */
+\f
+/* 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.
+
+   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.   */
+
+#ifdef WCHAR
+/* local function for re_compile_fastmap.
+   truncate wchar_t character to char.  */
+static unsigned char truncate_wchar (CHAR_T c);
+
+static unsigned char
+truncate_wchar (c)
+     CHAR_T c;
+{
+  unsigned char buf[MB_LEN_MAX];
+  int retval = wctomb(buf, c);
+  return retval > 0 ? buf[0] : (unsigned char)c;
+}
+#endif /* WCHAR */
+
+static int
+PREFIX(re_compile_fastmap) (bufp)
+     struct re_pattern_buffer *bufp;
+{
+  int j, k;
+#ifdef MATCH_MAY_ALLOCATE
+  PREFIX(fail_stack_type) fail_stack;
+#endif
+#ifndef REGEX_MALLOC
+  char *destination;
+#endif
+
+  register char *fastmap = bufp->fastmap;
+
+#ifdef WCHAR
+  /* We need to cast pattern to (wchar_t*), because we casted this compiled
+     pattern to (char*) in regex_compile.  */
+  UCHAR_T *pattern = (UCHAR_T*)bufp->buffer;
+  register UCHAR_T *pend = (UCHAR_T*) (bufp->buffer + bufp->used);
+#else /* BYTE */
+  UCHAR_T *pattern = bufp->buffer;
+  register UCHAR_T *pend = pattern + bufp->used;
+#endif /* WCHAR */
+  UCHAR_T *p = pattern;
+
+#ifdef REL_ALLOC
+  /* This holds the pointer to the failure stack, when
+     it is allocated relocatably.  */
+  fail_stack_elt_t *failure_stack_ptr;
+#endif
+
+  /* Assume that each path through the pattern can be null until
+     proven otherwise.  We set this false at the bottom of switch
+     statement, to which we get only if a particular path doesn't
+     match the empty string.  */
+  boolean path_can_be_null = true;
+
+  /* We aren't doing a `succeed_n' to begin with.  */
+  boolean succeed_n_p = false;
+
+  assert (fastmap != NULL && p != NULL);
+
+  INIT_FAIL_STACK ();
+  bzero (fastmap, 1 << BYTEWIDTH);  /* Assume nothing's valid.  */
+  bufp->fastmap_accurate = 1;      /* It will be when we're done.  */
+  bufp->can_be_null = 0;
+
+  while (1)
+    {
+      if (p == pend || *p == succeed)
+       {
+         /* We have reached the (effective) end of pattern.  */
+         if (!FAIL_STACK_EMPTY ())
+           {
+             bufp->can_be_null |= path_can_be_null;
+
+             /* Reset for next path.  */
+             path_can_be_null = true;
+
+             p = fail_stack.stack[--fail_stack.avail].pointer;
+
+             continue;
+           }
+         else
+           break;
+       }
+
+      /* We should never be about to go beyond the end of the pattern.  */
+      assert (p < pend);
+
+      switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
+       {
+
+        /* I guess the idea here is to simply not bother with a fastmap
+           if a backreference is used, since it's too hard to figure out
+           the fastmap for the corresponding group.  Setting
+           `can_be_null' stops `re_search_2' from using the fastmap, so
+           that is all we do.  */
+       case duplicate:
+         bufp->can_be_null = 1;
+          goto done;
+
+
+      /* Following are the cases which match a character.  These end
+         with `break'.  */
+
+#ifdef WCHAR
+       case exactn:
+          fastmap[truncate_wchar(p[1])] = 1;
+         break;
+#else /* BYTE */
+       case exactn:
+          fastmap[p[1]] = 1;
+         break;
+#endif /* WCHAR */
+#ifdef MBS_SUPPORT
+       case exactn_bin:
+         fastmap[p[1]] = 1;
+         break;
+#endif
+
+#ifdef WCHAR
+        /* It is hard to distinguish fastmap from (multi byte) characters
+           which depends on current locale.  */
+        case charset:
+       case charset_not:
+       case wordchar:
+       case notwordchar:
+          bufp->can_be_null = 1;
+          goto done;
+#else /* BYTE */
+        case charset:
+          for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+           if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
+              fastmap[j] = 1;
+         break;
+
+
+       case charset_not:
+         /* Chars beyond end of map must be allowed.  */
+         for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
+            fastmap[j] = 1;
+
+         for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+           if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
+              fastmap[j] = 1;
+          break;
+
+
+       case wordchar:
+         for (j = 0; j < (1 << BYTEWIDTH); j++)
+           if (SYNTAX (j) == Sword)
+             fastmap[j] = 1;
+         break;
+
+
+       case notwordchar:
+         for (j = 0; j < (1 << BYTEWIDTH); j++)
+           if (SYNTAX (j) != Sword)
+             fastmap[j] = 1;
+         break;
+#endif /* WCHAR */
+
+        case anychar:
+         {
+           int fastmap_newline = fastmap['\n'];
+
+           /* `.' matches anything ...  */
+           for (j = 0; j < (1 << BYTEWIDTH); j++)
+             fastmap[j] = 1;
+
+           /* ... except perhaps newline.  */
+           if (!(bufp->syntax & RE_DOT_NEWLINE))
+             fastmap['\n'] = fastmap_newline;
+
+           /* Return if we have already set `can_be_null'; if we have,
+              then the fastmap is irrelevant.  Something's wrong here.  */
+           else if (bufp->can_be_null)
+             goto done;
+
+           /* Otherwise, have to check alternative paths.  */
+           break;
+         }
+
+#ifdef emacs
+        case syntaxspec:
+         k = *p++;
+         for (j = 0; j < (1 << BYTEWIDTH); j++)
+           if (SYNTAX (j) == (enum syntaxcode) k)
+             fastmap[j] = 1;
+         break;
+
+
+       case notsyntaxspec:
+         k = *p++;
+         for (j = 0; j < (1 << BYTEWIDTH); j++)
+           if (SYNTAX (j) != (enum syntaxcode) k)
+             fastmap[j] = 1;
+         break;
+
+
+      /* All cases after this match the empty string.  These end with
+         `continue'.  */
+
+
+       case before_dot:
+       case at_dot:
+       case after_dot:
+          continue;
+#endif /* emacs */
+
+
+        case no_op:
+        case begline:
+        case endline:
+       case begbuf:
+       case endbuf:
+       case wordbound:
+       case notwordbound:
+       case wordbeg:
+       case wordend:
+        case push_dummy_failure:
+          continue;
+
+
+       case jump_n:
+        case pop_failure_jump:
+       case maybe_pop_jump:
+       case jump:
+        case jump_past_alt:
+       case dummy_failure_jump:
+          EXTRACT_NUMBER_AND_INCR (j, p);
+         p += j;
+         if (j > 0)
+           continue;
+
+          /* Jump backward implies we just went through the body of a
+             loop and matched nothing.  Opcode jumped to should be
+             `on_failure_jump' or `succeed_n'.  Just treat it like an
+             ordinary jump.  For a * loop, it has pushed its failure
+             point already; if so, discard that as redundant.  */
+          if ((re_opcode_t) *p != on_failure_jump
+             && (re_opcode_t) *p != succeed_n)
+           continue;
+
+          p++;
+          EXTRACT_NUMBER_AND_INCR (j, p);
+          p += j;
+
+          /* If what's on the stack is where we are now, pop it.  */
+          if (!FAIL_STACK_EMPTY ()
+             && fail_stack.stack[fail_stack.avail - 1].pointer == p)
+            fail_stack.avail--;
+
+          continue;
+
+
+        case on_failure_jump:
+        case on_failure_keep_string_jump:
+       handle_on_failure_jump:
+          EXTRACT_NUMBER_AND_INCR (j, p);
+
+          /* For some patterns, e.g., `(a?)?', `p+j' here points to the
+             end of the pattern.  We don't want to push such a point,
+             since when we restore it above, entering the switch will
+             increment `p' past the end of the pattern.  We don't need
+             to push such a point since we obviously won't find any more
+             fastmap entries beyond `pend'.  Such a pattern can match
+             the null string, though.  */
+          if (p + j < pend)
+            {
+              if (!PUSH_PATTERN_OP (p + j, fail_stack))
+               {
+                 RESET_FAIL_STACK ();
+                 return -2;
+               }
+            }
+          else
+            bufp->can_be_null = 1;
+
+          if (succeed_n_p)
+            {
+              EXTRACT_NUMBER_AND_INCR (k, p);  /* Skip the n.  */
+              succeed_n_p = false;
+           }
+
+          continue;
+
+
+       case succeed_n:
+          /* Get to the number of times to succeed.  */
+          p += OFFSET_ADDRESS_SIZE;
+
+          /* Increment p past the n for when k != 0.  */
+          EXTRACT_NUMBER_AND_INCR (k, p);
+          if (k == 0)
+           {
+              p -= 2 * OFFSET_ADDRESS_SIZE;
+             succeed_n_p = true;  /* Spaghetti code alert.  */
+              goto handle_on_failure_jump;
+            }
+          continue;
+
+
+       case set_number_at:
+          p += 2 * OFFSET_ADDRESS_SIZE;
+          continue;
+
+
+       case start_memory:
+        case stop_memory:
+         p += 2;
+         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.
+         Instead, look at the next alternative (remembered on the
+         stack), or quit if no more.  The test at the top of the loop
+         does these things.  */
+      path_can_be_null = false;
+      p = pend;
+    } /* while p */
+
+  /* Set `can_be_null' for the last path (also the first path, if the
+     pattern is empty).  */
+  bufp->can_be_null |= path_can_be_null;
+
+ done:
+  RESET_FAIL_STACK ();
+  return 0;
+}
+
+#else /* not INSIDE_RECURSION */
+
+int
+re_compile_fastmap (bufp)
+     struct re_pattern_buffer *bufp;
+{
+# ifdef MBS_SUPPORT
+  if (MB_CUR_MAX != 1)
+    return wcs_re_compile_fastmap(bufp);
+  else
+# endif
+    return byte_re_compile_fastmap(bufp);
+} /* re_compile_fastmap */
+#ifdef _LIBC
+weak_alias (__re_compile_fastmap, re_compile_fastmap)
+#endif
+\f
+
+/* 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;
+    }
+}
+#ifdef _LIBC
+weak_alias (__re_set_registers, re_set_registers)
+#endif
+\f
+/* 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);
+}
+#ifdef _LIBC
+weak_alias (__re_search, re_search)
+#endif
+
+
+/* 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, string1, size1, string2, size2, startpos, range, regs, stop)
+     struct re_pattern_buffer *bufp;
+     const char *string1, *string2;
+     int size1, size2;
+     int startpos;
+     int range;
+     struct re_registers *regs;
+     int stop;
+{
+# ifdef MBS_SUPPORT
+  if (MB_CUR_MAX != 1)
+    return wcs_re_search_2 (bufp, string1, size1, string2, size2, startpos,
+                           range, regs, stop);
+  else
+# endif
+    return byte_re_search_2 (bufp, string1, size1, string2, size2, startpos,
+                            range, regs, stop);
+} /* re_search_2 */
+#ifdef _LIBC
+weak_alias (__re_search_2, re_search_2)
+#endif
+
+#endif /* not INSIDE_RECURSION */
+
+#ifdef INSIDE_RECURSION
+
+#ifdef MATCH_MAY_ALLOCATE
+# define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
+#else
+# define FREE_VAR(var) if (var) free (var); var = NULL
+#endif
+
+#ifdef WCHAR
+# define FREE_WCS_BUFFERS()    \
+  do {                         \
+    FREE_VAR (string1);                \
+    FREE_VAR (string2);                \
+    FREE_VAR (mbs_offset1);    \
+    FREE_VAR (mbs_offset2);    \
+  } while (0)
+
+#endif
+
+static int
+PREFIX(re_search_2) (bufp, string1, size1, string2, size2, startpos, range,
+                    regs, stop)
+     struct re_pattern_buffer *bufp;
+     const char *string1, *string2;
+     int size1, size2;
+     int startpos;
+     int range;
+     struct re_registers *regs;
+     int stop;
+{
+  int val;
+  register char *fastmap = bufp->fastmap;
+  register RE_TRANSLATE_TYPE translate = bufp->translate;
+  int total_size = size1 + size2;
+  int endpos = startpos + range;
+#ifdef WCHAR
+  /* We need wchar_t* buffers correspond to cstring1, cstring2.  */
+  wchar_t *wcs_string1 = NULL, *wcs_string2 = NULL;
+  /* We need the size of wchar_t buffers correspond to csize1, csize2.  */
+  int wcs_size1 = 0, wcs_size2 = 0;
+  /* offset buffer for optimizatoin. See convert_mbs_to_wc.  */
+  int *mbs_offset1 = NULL, *mbs_offset2 = NULL;
+  /* They hold whether each wchar_t is binary data or not.  */
+  char *is_binary = NULL;
+#endif /* WCHAR */
+
+  /* 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 that must be anchored.  */
+  if (bufp->used > 0 && range > 0
+      && ((re_opcode_t) bufp->buffer[0] == begbuf
+         /* `begline' is like `begbuf' if it cannot match at newlines.  */
+         || ((re_opcode_t) bufp->buffer[0] == begline
+             && !bufp->newline_anchor)))
+    {
+      if (startpos > 0)
+       return -1;
+      else
+       range = 1;
+    }
+
+#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 - startpos;
+      if (range <= 0)
+       return -1;
+    }
+#endif /* emacs */
+
+  /* Update the fastmap now if not correct already.  */
+  if (fastmap && !bufp->fastmap_accurate)
+    if (re_compile_fastmap (bufp) == -2)
+      return -2;
+
+#ifdef WCHAR
+  /* Allocate wchar_t array for wcs_string1 and wcs_string2 and
+     fill them with converted string.  */
+  if (size1 != 0)
+    {
+      wcs_string1 = REGEX_TALLOC (size1 + 1, CHAR_T);
+      mbs_offset1 = REGEX_TALLOC (size1 + 1, int);
+      is_binary = REGEX_TALLOC (size1 + 1, char);
+      if (!wcs_string1 || !mbs_offset1 || !is_binary)
+       {
+         FREE_VAR (wcs_string1);
+         FREE_VAR (mbs_offset1);
+         FREE_VAR (is_binary);
+         return -2;
+       }
+      wcs_size1 = convert_mbs_to_wcs(wcs_string1, string1, size1,
+                                    mbs_offset1, is_binary);
+      wcs_string1[wcs_size1] = L'\0'; /* for a sentinel  */
+      FREE_VAR (is_binary);
+    }
+  if (size2 != 0)
+    {
+      wcs_string2 = REGEX_TALLOC (size2 + 1, CHAR_T);
+      mbs_offset2 = REGEX_TALLOC (size2 + 1, int);
+      is_binary = REGEX_TALLOC (size2 + 1, char);
+      if (!wcs_string2 || !mbs_offset2 || !is_binary)
+       {
+         FREE_WCS_BUFFERS ();
+         FREE_VAR (is_binary);
+         return -2;
+       }
+      wcs_size2 = convert_mbs_to_wcs(wcs_string2, string2, size2,
+                                    mbs_offset2, is_binary);
+      wcs_string2[wcs_size2] = L'\0'; /* for a sentinel  */
+      FREE_VAR (is_binary);
+    }
+#endif /* WCHAR */
+
+
+  /* Loop through the string, looking for a place to start matching.  */
+  for (;;)
+    {
+      /* 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)
+       {
+         if (range > 0)        /* Searching forwards.  */
+           {
+             register const char *d;
+             register int lim = 0;
+             int irange = range;
+
+              if (startpos < size1 && startpos + range >= size1)
+                lim = range - (size1 - startpos);
+
+             d = (startpos >= size1 ? string2 - size1 : string1) + startpos;
+
+              /* Written out as an if-else to avoid testing `translate'
+                 inside the loop.  */
+             if (translate)
+                while (range > lim
+                       && !fastmap[(unsigned char)
+                                  translate[(unsigned char) *d++]])
+                  range--;
+             else
+                while (range > lim && !fastmap[(unsigned char) *d++])
+                  range--;
+
+             startpos += irange - range;
+           }
+         else                          /* Searching backwards.  */
+           {
+             register CHAR_T c = (size1 == 0 || startpos >= size1
+                                     ? string2[startpos - size1]
+                                     : string1[startpos]);
+
+             if (!fastmap[(unsigned char) TRANSLATE (c)])
+               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)
+       {
+#ifdef WCHAR
+         FREE_WCS_BUFFERS ();
+#endif
+         return -1;
+       }
+
+#ifdef WCHAR
+      val = wcs_re_match_2_internal (bufp, string1, size1, string2,
+                                    size2, startpos, regs, stop,
+                                    wcs_string1, wcs_size1,
+                                    wcs_string2, wcs_size2,
+                                    mbs_offset1, mbs_offset2);
+#else /* BYTE */
+      val = byte_re_match_2_internal (bufp, string1, size1, string2,
+                                     size2, startpos, regs, stop);
+#endif /* BYTE */
+
+#ifndef REGEX_MALLOC
+# ifdef C_ALLOCA
+      alloca (0);
+# endif
+#endif
+
+      if (val >= 0)
+       {
+#ifdef WCHAR
+         FREE_WCS_BUFFERS ();
+#endif
+         return startpos;
+       }
+
+      if (val == -2)
+       {
+#ifdef WCHAR
+         FREE_WCS_BUFFERS ();
+#endif
+         return -2;
+       }
+
+    advance:
+      if (!range)
+        break;
+      else if (range > 0)
+        {
+          range--;
+          startpos++;
+        }
+      else
+        {
+          range++;
+          startpos--;
+        }
+    }
+#ifdef WCHAR
+  FREE_WCS_BUFFERS ();
+#endif
+  return -1;
+}
+
+#ifdef WCHAR
+/* This converts PTR, a pointer into one of the search wchar_t strings
+   `string1' and `string2' into an multibyte string offset from the
+   beginning of that string. We use mbs_offset to optimize.
+   See convert_mbs_to_wcs.  */
+# define POINTER_TO_OFFSET(ptr)                                                \
+  (FIRST_STRING_P (ptr)                                                        \
+   ? ((regoff_t)(mbs_offset1 != NULL? mbs_offset1[(ptr)-string1] : 0)) \
+   : ((regoff_t)((mbs_offset2 != NULL? mbs_offset2[(ptr)-string2] : 0) \
+                + csize1)))
+#else /* BYTE */
+/* 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)))
+#endif /* WCHAR */
+
+/* Macros for dealing with the split strings in re_match_2.  */
+
+#define MATCHING_IN_FIRST_STRING  (dend == end_match_1)
+
+/* Call before fetching a character with *d.  This switches over to
+   string2 if necessary.  */
+#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;                                              \
+    }
+
+/* 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.  */
+#ifdef WCHAR
+/* Use internationalized API instead of SYNTAX.  */
+# define WORDCHAR_P(d)                                                 \
+  (iswalnum ((wint_t)((d) == end1 ? *string2                           \
+           : (d) == string2 - 1 ? *(end1 - 1) : *(d))) != 0)
+#else /* BYTE */
+# define WORDCHAR_P(d)                                                 \
+  (SYNTAX ((d) == end1 ? *string2                                      \
+           : (d) == string2 - 1 ? *(end1 - 1) : *(d))                  \
+   == Sword)
+#endif /* WCHAR */
+
+/* Disabled due to a compiler bug -- see comment at case wordbound */
+#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
+# ifdef WCHAR
+#  define FREE_VARIABLES()                                             \
+  do {                                                                 \
+    REGEX_FREE_STACK (fail_stack.stack);                               \
+    FREE_VAR (regstart);                                               \
+    FREE_VAR (regend);                                                 \
+    FREE_VAR (old_regstart);                                           \
+    FREE_VAR (old_regend);                                             \
+    FREE_VAR (best_regstart);                                          \
+    FREE_VAR (best_regend);                                            \
+    FREE_VAR (reg_info);                                               \
+    FREE_VAR (reg_dummy);                                              \
+    FREE_VAR (reg_info_dummy);                                         \
+    if (!cant_free_wcs_buf)                                            \
+      {                                                                        \
+        FREE_VAR (string1);                                            \
+        FREE_VAR (string2);                                            \
+        FREE_VAR (mbs_offset1);                                                \
+        FREE_VAR (mbs_offset2);                                                \
+      }                                                                        \
+  } while (0)
+# else /* BYTE */
+#  define FREE_VARIABLES()                                             \
+  do {                                                                 \
+    REGEX_FREE_STACK (fail_stack.stack);                               \
+    FREE_VAR (regstart);                                               \
+    FREE_VAR (regend);                                                 \
+    FREE_VAR (old_regstart);                                           \
+    FREE_VAR (old_regend);                                             \
+    FREE_VAR (best_regstart);                                          \
+    FREE_VAR (best_regend);                                            \
+    FREE_VAR (reg_info);                                               \
+    FREE_VAR (reg_dummy);                                              \
+    FREE_VAR (reg_info_dummy);                                         \
+  } while (0)
+# endif /* WCHAR */
+#else
+# ifdef WCHAR
+#  define FREE_VARIABLES()                                             \
+  do {                                                                 \
+    if (!cant_free_wcs_buf)                                            \
+      {                                                                        \
+        FREE_VAR (string1);                                            \
+        FREE_VAR (string2);                                            \
+        FREE_VAR (mbs_offset1);                                                \
+        FREE_VAR (mbs_offset2);                                                \
+      }                                                                        \
+  } while (0)
+# else /* BYTE */
+#  define FREE_VARIABLES() ((void)0) /* Do nothing!  But inhibit gcc warning. */
+# endif /* WCHAR */
+#endif /* not MATCH_MAY_ALLOCATE */
+
+/* These values must meet several constraints.  They must not be valid
+   register values; since we have a limit of 255 registers (because
+   we use only one byte in the pattern for the register number), we can
+   use numbers larger than 255.  They must differ by 1, because of
+   NUM_FAILURE_ITEMS above.  And the value for the lowest register must
+   be larger than the value for the highest register, so we do not try
+   to actually save any registers when none are active.  */
+#define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
+#define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)
+\f
+#else /* not INSIDE_RECURSION */
+/* 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;
+# ifdef MBS_SUPPORT
+  if (MB_CUR_MAX != 1)
+    result = wcs_re_match_2_internal (bufp, NULL, 0, string, size,
+                                     pos, regs, size,
+                                     NULL, 0, NULL, 0, NULL, NULL);
+  else
+# endif
+    result = byte_re_match_2_internal (bufp, NULL, 0, string, size,
+                                 pos, regs, size);
+# ifndef REGEX_MALLOC
+#  ifdef C_ALLOCA
+  alloca (0);
+#  endif
+# endif
+  return result;
+}
+# ifdef _LIBC
+weak_alias (__re_match, re_match)
+# endif
+#endif /* not emacs */
+
+#endif /* not INSIDE_RECURSION */
+
+#ifdef INSIDE_RECURSION
+static boolean PREFIX(group_match_null_string_p) _RE_ARGS ((UCHAR_T **p,
+                                                   UCHAR_T *end,
+                                       PREFIX(register_info_type) *reg_info));
+static boolean PREFIX(alt_match_null_string_p) _RE_ARGS ((UCHAR_T *p,
+                                                 UCHAR_T *end,
+                                       PREFIX(register_info_type) *reg_info));
+static boolean PREFIX(common_op_match_null_string_p) _RE_ARGS ((UCHAR_T **p,
+                                                       UCHAR_T *end,
+                                       PREFIX(register_info_type) *reg_info));
+static int PREFIX(bcmp_translate) _RE_ARGS ((const CHAR_T *s1, const CHAR_T *s2,
+                                    int len, char *translate));
+#else /* not INSIDE_RECURSION */
+
+/* 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 MBS_SUPPORT
+  if (MB_CUR_MAX != 1)
+    result = wcs_re_match_2_internal (bufp, string1, size1, string2, size2,
+                                     pos, regs, stop,
+                                     NULL, 0, NULL, 0, NULL, NULL);
+  else
+# endif
+    result = byte_re_match_2_internal (bufp, string1, size1, string2, size2,
+                                 pos, regs, stop);
+
+#ifndef REGEX_MALLOC
+# ifdef C_ALLOCA
+  alloca (0);
+# endif
+#endif
+  return result;
+}
+#ifdef _LIBC
+weak_alias (__re_match_2, re_match_2)
+#endif
+
+#endif /* not INSIDE_RECURSION */
+
+#ifdef INSIDE_RECURSION
+
+#ifdef WCHAR
+static int count_mbs_length PARAMS ((int *, int));
+
+/* This check the substring (from 0, to length) of the multibyte string,
+   to which offset_buffer correspond. And count how many wchar_t_characters
+   the substring occupy. We use offset_buffer to optimization.
+   See convert_mbs_to_wcs.  */
+
+static int
+count_mbs_length(offset_buffer, length)
+     int *offset_buffer;
+     int length;
+{
+  int upper, lower;
+
+  /* Check whether the size is valid.  */
+  if (length < 0)
+    return -1;
+
+  if (offset_buffer == NULL)
+    return 0;
+
+  /* If there are no multibyte character, offset_buffer[i] == i.
+   Optmize for this case.  */
+  if (offset_buffer[length] == length)
+    return length;
+
+  /* Set up upper with length. (because for all i, offset_buffer[i] >= i)  */
+  upper = length;
+  lower = 0;
+
+  while (true)
+    {
+      int middle = (lower + upper) / 2;
+      if (middle == lower || middle == upper)
+       break;
+      if (offset_buffer[middle] > length)
+       upper = middle;
+      else if (offset_buffer[middle] < length)
+       lower = middle;
+      else
+       return middle;
+    }
+
+  return -1;
+}
+#endif /* WCHAR */
+
+/* This is a separate function so that we can force an alloca cleanup
+   afterwards.  */
+#ifdef WCHAR
+static int
+wcs_re_match_2_internal (bufp, cstring1, csize1, cstring2, csize2, pos,
+                        regs, stop, string1, size1, string2, size2,
+                        mbs_offset1, mbs_offset2)
+     struct re_pattern_buffer *bufp;
+     const char *cstring1, *cstring2;
+     int csize1, csize2;
+     int pos;
+     struct re_registers *regs;
+     int stop;
+     /* string1 == string2 == NULL means string1/2, size1/2 and
+       mbs_offset1/2 need seting up in this function.  */
+     /* We need wchar_t* buffers correspond to cstring1, cstring2.  */
+     wchar_t *string1, *string2;
+     /* We need the size of wchar_t buffers correspond to csize1, csize2.  */
+     int size1, size2;
+     /* offset buffer for optimizatoin. See convert_mbs_to_wc.  */
+     int *mbs_offset1, *mbs_offset2;
+#else /* BYTE */
+static int
+byte_re_match_2_internal (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;
+#endif /* BYTE */
+{
+  /* General temporaries.  */
+  int mcnt;
+  UCHAR_T *p1;
+#ifdef WCHAR
+  /* They hold whether each wchar_t is binary data or not.  */
+  char *is_binary = NULL;
+  /* If true, we can't free string1/2, mbs_offset1/2.  */
+  int cant_free_wcs_buf = 1;
+#endif /* WCHAR */
+
+  /* Just past the end of the corresponding string.  */
+  const CHAR_T *end1, *end2;
+
+  /* Pointers into string1 and string2, just past the last characters in
+     each to consider matching.  */
+  const CHAR_T *end_match_1, *end_match_2;
+
+  /* Where we are in the data, and the end of the current string.  */
+  const CHAR_T *d, *dend;
+
+  /* Where we are in the pattern, and the end of the pattern.  */
+#ifdef WCHAR
+  UCHAR_T *pattern, *p;
+  register UCHAR_T *pend;
+#else /* BYTE */
+  UCHAR_T *p = bufp->buffer;
+  register UCHAR_T *pend = p + bufp->used;
+#endif /* WCHAR */
+
+  /* Mark the opcode just after a start_memory, so we can test for an
+     empty subpattern when we get to the stop_memory.  */
+  UCHAR_T *just_past_start_mem = 0;
+
+  /* We use this to map every character in the string.  */
+  RE_TRANSLATE_TYPE translate = bufp->translate;
+
+  /* Failure point stack.  Each place that can handle a failure further
+     down the line pushes a failure point on this stack.  It consists of
+     restart, regend, and reg_info 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.  If the latter is zero, the failure point is
+     a ``dummy''; if a failure happens and the failure point is a dummy,
+     it gets discarded and the next next one is tried.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
+  PREFIX(fail_stack_type) fail_stack;
+#endif
+#ifdef DEBUG
+  static unsigned failure_id;
+  unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
+#endif
+
+#ifdef REL_ALLOC
+  /* 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;
+
+  /* The currently active registers.  */
+  active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
+  active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;
+
+  /* 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.  */
+  const CHAR_T **regstart, **regend;
+#endif
+
+  /* If a group that's operated upon by a repetition operator fails to
+     match anything, then the register for its start will need to be
+     restored because it will have been set to wherever in the string we
+     are when we last see its open-group operator.  Similarly for a
+     register's end.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+  const CHAR_T **old_regstart, **old_regend;
+#endif
+
+  /* The is_active field of reg_info helps us keep track of which (possibly
+     nested) subexpressions we are currently in. The matched_something
+     field of reg_info[reg_num] helps us tell whether or not we have
+     matched any of the pattern so far this time through the reg_num-th
+     subexpression.  These two fields get reset each time through any
+     loop their register is in.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
+  PREFIX(register_info_type) *reg_info;
+#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.  */
+  const CHAR_T **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.  */
+  const CHAR_T *match_end = NULL;
+
+  /* This helps SET_REGS_MATCHED avoid doing redundant work.  */
+  int set_regs_matched_done = 0;
+
+  /* Used when we pop values we don't care about.  */
+#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
+  const CHAR_T **reg_dummy;
+  PREFIX(register_info_type) *reg_info_dummy;
+#endif
+
+#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, const CHAR_T *);
+      regend = REGEX_TALLOC (num_regs, const CHAR_T *);
+      old_regstart = REGEX_TALLOC (num_regs, const CHAR_T *);
+      old_regend = REGEX_TALLOC (num_regs, const CHAR_T *);
+      best_regstart = REGEX_TALLOC (num_regs, const CHAR_T *);
+      best_regend = REGEX_TALLOC (num_regs, const CHAR_T *);
+      reg_info = REGEX_TALLOC (num_regs, PREFIX(register_info_type));
+      reg_dummy = REGEX_TALLOC (num_regs, const CHAR_T *);
+      reg_info_dummy = REGEX_TALLOC (num_regs, PREFIX(register_info_type));
+
+      if (!(regstart && regend && old_regstart && old_regend && reg_info
+            && best_regstart && best_regend && reg_dummy && reg_info_dummy))
+        {
+          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 = old_regstart = old_regend = best_regstart
+        = best_regend = reg_dummy = NULL;
+      reg_info = reg_info_dummy = (PREFIX(register_info_type) *) NULL;
+    }
+#endif /* MATCH_MAY_ALLOCATE */
+
+  /* The starting position is bogus.  */
+#ifdef WCHAR
+  if (pos < 0 || pos > csize1 + csize2)
+#else /* BYTE */
+  if (pos < 0 || pos > size1 + size2)
+#endif
+    {
+      FREE_VARIABLES ();
+      return -1;
+    }
+
+#ifdef WCHAR
+  /* Allocate wchar_t array for string1 and string2 and
+     fill them with converted string.  */
+  if (string1 == NULL && string2 == NULL)
+    {
+      /* We need seting up buffers here.  */
+
+      /* We must free wcs buffers in this function.  */
+      cant_free_wcs_buf = 0;
+
+      if (csize1 != 0)
+       {
+         string1 = REGEX_TALLOC (csize1 + 1, CHAR_T);
+         mbs_offset1 = REGEX_TALLOC (csize1 + 1, int);
+         is_binary = REGEX_TALLOC (csize1 + 1, char);
+         if (!string1 || !mbs_offset1 || !is_binary)
+           {
+             FREE_VAR (string1);
+             FREE_VAR (mbs_offset1);
+             FREE_VAR (is_binary);
+             return -2;
+           }
+       }
+      if (csize2 != 0)
+       {
+         string2 = REGEX_TALLOC (csize2 + 1, CHAR_T);
+         mbs_offset2 = REGEX_TALLOC (csize2 + 1, int);
+         is_binary = REGEX_TALLOC (csize2 + 1, char);
+         if (!string2 || !mbs_offset2 || !is_binary)
+           {
+             FREE_VAR (string1);
+             FREE_VAR (mbs_offset1);
+             FREE_VAR (string2);
+             FREE_VAR (mbs_offset2);
+             FREE_VAR (is_binary);
+             return -2;
+           }
+         size2 = convert_mbs_to_wcs(string2, cstring2, csize2,
+                                    mbs_offset2, is_binary);
+         string2[size2] = L'\0'; /* for a sentinel  */
+         FREE_VAR (is_binary);
+       }
+    }
+
+  /* We need to cast pattern to (wchar_t*), because we casted this compiled
+     pattern to (char*) in regex_compile.  */
+  p = pattern = (CHAR_T*)bufp->buffer;
+  pend = (CHAR_T*)(bufp->buffer + bufp->used);
+
+#endif /* WCHAR */
+
+  /* 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 (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
+    {
+      regstart[mcnt] = regend[mcnt]
+        = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;
+
+      REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
+      IS_ACTIVE (reg_info[mcnt]) = 0;
+      MATCHED_SOMETHING (reg_info[mcnt]) = 0;
+      EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
+    }
+
+  /* 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;
+#ifdef WCHAR
+      mbs_offset2 = mbs_offset1;
+      csize2 = csize1;
+      mbs_offset1 = NULL;
+      csize1 = 0;
+#endif
+    }
+  end1 = string1 + size1;
+  end2 = string2 + size2;
+
+  /* Compute where to stop matching, within the two strings.  */
+#ifdef WCHAR
+  if (stop <= csize1)
+    {
+      mcnt = count_mbs_length(mbs_offset1, stop);
+      end_match_1 = string1 + mcnt;
+      end_match_2 = string2;
+    }
+  else
+    {
+      if (stop > csize1 + csize2)
+       stop = csize1 + csize2;
+      end_match_1 = end1;
+      mcnt = count_mbs_length(mbs_offset2, stop-csize1);
+      end_match_2 = string2 + mcnt;
+    }
+  if (mcnt < 0)
+    { /* count_mbs_length return error.  */
+      FREE_VARIABLES ();
+      return -1;
+    }
+#else
+  if (stop <= size1)
+    {
+      end_match_1 = string1 + stop;
+      end_match_2 = string2;
+    }
+  else
+    {
+      end_match_1 = end1;
+      end_match_2 = string2 + stop - size1;
+    }
+#endif /* WCHAR */
+
+  /* `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'.  */
+#ifdef WCHAR
+  if (size1 > 0 && pos <= csize1)
+    {
+      mcnt = count_mbs_length(mbs_offset1, pos);
+      d = string1 + mcnt;
+      dend = end_match_1;
+    }
+  else
+    {
+      mcnt = count_mbs_length(mbs_offset2, pos-csize1);
+      d = string2 + mcnt;
+      dend = end_match_2;
+    }
+
+  if (mcnt < 0)
+    { /* count_mbs_length return error.  */
+      FREE_VARIABLES ();
+      return -1;
+    }
+#else
+  if (size1 > 0 && pos <= size1)
+    {
+      d = string1 + pos;
+      dend = end_match_1;
+    }
+  else
+    {
+      d = string2 + pos - size1;
+      dend = end_match_2;
+    }
+#endif /* WCHAR */
+
+  DEBUG_PRINT1 ("The compiled pattern is:\n");
+  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 (;;)
+    {
+#ifdef _LIBC
+      DEBUG_PRINT2 ("\n%p: ", p);
+#else
+      DEBUG_PRINT2 ("\n0x%x: ", p);
+#endif
+
+      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)
+                                   == MATCHING_IN_FIRST_STRING);
+             /* 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 = !MATCHING_IN_FIRST_STRING;
+
+              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 (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
+                        {
+                          best_regstart[mcnt] = regstart[mcnt];
+                          best_regend[mcnt] = regend[mcnt];
+                        }
+                    }
+                  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 (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
+                   {
+                     regstart[mcnt] = best_regstart[mcnt];
+                     regend[mcnt] = best_regend[mcnt];
+                   }
+                }
+            } /* 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;
+#ifdef WCHAR
+                 if (MATCHING_IN_FIRST_STRING)
+                   regs->end[0] = mbs_offset1 != NULL ?
+                                       mbs_offset1[d-string1] : 0;
+                 else
+                   regs->end[0] = csize1 + (mbs_offset2 != NULL ?
+                                            mbs_offset2[d-string2] : 0);
+#else
+                  regs->end[0] = (MATCHING_IN_FIRST_STRING
+                                 ? ((regoff_t) (d - string1))
+                                 : ((regoff_t) (d - string2 + size1)));
+#endif /* WCHAR */
+                }
+
+              /* Go through the first `min (num_regs, regs->num_regs)'
+                 registers, since that is all we initialized.  */
+             for (mcnt = 1; (unsigned) mcnt < MIN (num_regs, regs->num_regs);
+                  mcnt++)
+               {
+                  if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
+                    regs->start[mcnt] = regs->end[mcnt] = -1;
+                  else
+                    {
+                     regs->start[mcnt]
+                       = (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
+                      regs->end[mcnt]
+                       = (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
+                    }
+               }
+
+              /* 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 (mcnt = num_regs; (unsigned) mcnt < regs->num_regs; mcnt++)
+                regs->start[mcnt] = regs->end[mcnt] = -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);
+
+#ifdef WCHAR
+         if (MATCHING_IN_FIRST_STRING)
+           mcnt = mbs_offset1 != NULL ? mbs_offset1[d-string1] : 0;
+         else
+           mcnt = (mbs_offset2 != NULL ? mbs_offset2[d-string2] : 0) +
+                       csize1;
+          mcnt -= pos;
+#else
+          mcnt = d - pos - (MATCHING_IN_FIRST_STRING
+                           ? string1
+                           : string2 - size1);
+#endif /* WCHAR */
+
+          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:
+#ifdef MBS_SUPPORT
+       case exactn_bin:
+#endif
+         mcnt = *p++;
+          DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);
+
+          /* This is written out as an if-else so we don't waste time
+             testing `translate' inside the loop.  */
+          if (translate)
+           {
+             do
+               {
+                 PREFETCH ();
+#ifdef WCHAR
+                 if (*d <= 0xff)
+                   {
+                     if ((UCHAR_T) translate[(unsigned char) *d++]
+                         != (UCHAR_T) *p++)
+                       goto fail;
+                   }
+                 else
+                   {
+                     if (*d++ != (CHAR_T) *p++)
+                       goto fail;
+                   }
+#else
+                 if ((UCHAR_T) translate[(unsigned char) *d++]
+                     != (UCHAR_T) *p++)
+                    goto fail;
+#endif /* WCHAR */
+               }
+             while (--mcnt);
+           }
+         else
+           {
+             do
+               {
+                 PREFETCH ();
+                 if (*d++ != (CHAR_T) *p++) goto fail;
+               }
+             while (--mcnt);
+           }
+         SET_REGS_MATCHED ();
+          break;
+
+
+        /* Match any character except possibly a newline or a null.  */
+       case anychar:
+          DEBUG_PRINT1 ("EXECUTING anychar.\n");
+
+          PREFETCH ();
+
+          if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
+              || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
+           goto fail;
+
+          SET_REGS_MATCHED ();
+          DEBUG_PRINT2 ("  Matched `%ld'.\n", (long int) *d);
+          d++;
+         break;
+
+
+       case charset:
+       case charset_not:
+         {
+           register UCHAR_T c;
+#ifdef WCHAR
+           unsigned int i, char_class_length, coll_symbol_length,
+              equiv_class_length, ranges_length, chars_length, length;
+           CHAR_T *workp, *workp2, *charset_top;
+#define WORK_BUFFER_SIZE 128
+            CHAR_T str_buf[WORK_BUFFER_SIZE];
+# ifdef _LIBC
+           uint32_t nrules;
+# endif /* _LIBC */
+#endif /* WCHAR */
+           boolean not = (re_opcode_t) *(p - 1) == charset_not;
+
+            DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");
+           PREFETCH ();
+           c = TRANSLATE (*d); /* The character to match.  */
+#ifdef WCHAR
+# ifdef _LIBC
+           nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+# endif /* _LIBC */
+           charset_top = p - 1;
+           char_class_length = *p++;
+           coll_symbol_length = *p++;
+           equiv_class_length = *p++;
+           ranges_length = *p++;
+           chars_length = *p++;
+           /* p points charset[6], so the address of the next instruction
+              (charset[l+m+n+2o+k+p']) equals p[l+m+n+2*o+p'],
+              where l=length of char_classes, m=length of collating_symbol,
+              n=equivalence_class, o=length of char_range,
+              p'=length of character.  */
+           workp = p;
+           /* Update p to indicate the next instruction.  */
+           p += char_class_length + coll_symbol_length+ equiv_class_length +
+              2*ranges_length + chars_length;
+
+            /* match with char_class?  */
+           for (i = 0; i < char_class_length ; i += CHAR_CLASS_SIZE)
+             {
+               wctype_t wctype;
+               uintptr_t alignedp = ((uintptr_t)workp
+                                     + __alignof__(wctype_t) - 1)
+                                     & ~(uintptr_t)(__alignof__(wctype_t) - 1);
+               wctype = *((wctype_t*)alignedp);
+               workp += CHAR_CLASS_SIZE;
+               if (iswctype((wint_t)c, wctype))
+                 goto char_set_matched;
+             }
+
+            /* match with collating_symbol?  */
+# ifdef _LIBC
+           if (nrules != 0)
+             {
+               const unsigned char *extra = (const unsigned char *)
+                 _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+
+               for (workp2 = workp + coll_symbol_length ; workp < workp2 ;
+                    workp++)
+                 {
+                   int32_t *wextra;
+                   wextra = (int32_t*)(extra + *workp++);
+                   for (i = 0; i < *wextra; ++i)
+                     if (TRANSLATE(d[i]) != wextra[1 + i])
+                       break;
+
+                   if (i == *wextra)
+                     {
+                       /* Update d, however d will be incremented at
+                          char_set_matched:, we decrement d here.  */
+                       d += i - 1;
+                       goto char_set_matched;
+                     }
+                 }
+             }
+           else /* (nrules == 0) */
+# endif
+             /* If we can't look up collation data, we use wcscoll
+                instead.  */
+             {
+               for (workp2 = workp + coll_symbol_length ; workp < workp2 ;)
+                 {
+                   const CHAR_T *backup_d = d, *backup_dend = dend;
+                   length = wcslen(workp);
+
+                   /* If wcscoll(the collating symbol, whole string) > 0,
+                      any substring of the string never match with the
+                      collating symbol.  */
+                   if (wcscoll(workp, d) > 0)
+                     {
+                       workp += length + 1;
+                       continue;
+                     }
+
+                   /* First, we compare the collating symbol with
+                      the first character of the string.
+                      If it don't match, we add the next character to
+                      the compare buffer in turn.  */
+                   for (i = 0 ; i < WORK_BUFFER_SIZE-1 ; i++, d++)
+                     {
+                       int match;
+                       if (d == dend)
+                         {
+                           if (dend == end_match_2)
+                             break;
+                           d = string2;
+                           dend = end_match_2;
+                         }
+
+                       /* add next character to the compare buffer.  */
+                       str_buf[i] = TRANSLATE(*d);
+                       str_buf[i+1] = '\0';
+
+                       match = wcscoll(workp, str_buf);
+                       if (match == 0)
+                         goto char_set_matched;
+
+                       if (match < 0)
+                         /* (str_buf > workp) indicate (str_buf + X > workp),
+                            because for all X (str_buf + X > str_buf).
+                            So we don't need continue this loop.  */
+                         break;
+
+                       /* Otherwise(str_buf < workp),
+                          (str_buf+next_character) may equals (workp).
+                          So we continue this loop.  */
+                     }
+                   /* not matched */
+                   d = backup_d;
+                   dend = backup_dend;
+                   workp += length + 1;
+                 }
+              }
+            /* match with equivalence_class?  */
+# ifdef _LIBC
+           if (nrules != 0)
+             {
+                const CHAR_T *backup_d = d, *backup_dend = dend;
+               /* Try to match the equivalence class against
+                  those known to the collate implementation.  */
+               const int32_t *table;
+               const int32_t *weights;
+               const int32_t *extra;
+               const int32_t *indirect;
+               int32_t idx, idx2;
+               wint_t *cp;
+               size_t len;
+
+               /* This #include defines a local function!  */
+#  include <locale/weightwc.h>
+
+               table = (const int32_t *)
+                 _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEWC);
+               weights = (const wint_t *)
+                 _NL_CURRENT (LC_COLLATE, _NL_COLLATE_WEIGHTWC);
+               extra = (const wint_t *)
+                 _NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAWC);
+               indirect = (const int32_t *)
+                 _NL_CURRENT (LC_COLLATE, _NL_COLLATE_INDIRECTWC);
+
+               /* Write 1 collating element to str_buf, and
+                  get its index.  */
+               idx2 = 0;
+
+               for (i = 0 ; idx2 == 0 && i < WORK_BUFFER_SIZE - 1; i++)
+                 {
+                   cp = (wint_t*)str_buf;
+                   if (d == dend)
+                     {
+                       if (dend == end_match_2)
+                         break;
+                       d = string2;
+                       dend = end_match_2;
+                     }
+                   str_buf[i] = TRANSLATE(*(d+i));
+                   str_buf[i+1] = '\0'; /* sentinel */
+                   idx2 = findidx ((const wint_t**)&cp);
+                 }
+
+               /* Update d, however d will be incremented at
+                  char_set_matched:, we decrement d here.  */
+               d = backup_d + ((wchar_t*)cp - (wchar_t*)str_buf - 1);
+               if (d >= dend)
+                 {
+                   if (dend == end_match_2)
+                       d = dend;
+                   else
+                     {
+                       d = string2;
+                       dend = end_match_2;
+                     }
+                 }
+
+               len = weights[idx2];
+
+               for (workp2 = workp + equiv_class_length ; workp < workp2 ;
+                    workp++)
+                 {
+                   idx = (int32_t)*workp;
+                   /* We already checked idx != 0 in regex_compile. */
+
+                   if (idx2 != 0 && len == weights[idx])
+                     {
+                       int cnt = 0;
+                       while (cnt < len && (weights[idx + 1 + cnt]
+                                            == weights[idx2 + 1 + cnt]))
+                         ++cnt;
+
+                       if (cnt == len)
+                         goto char_set_matched;
+                     }
+                 }
+               /* not matched */
+                d = backup_d;
+                dend = backup_dend;
+             }
+           else /* (nrules == 0) */
+# endif
+             /* If we can't look up collation data, we use wcscoll
+                instead.  */
+             {
+               for (workp2 = workp + equiv_class_length ; workp < workp2 ;)
+                 {
+                   const CHAR_T *backup_d = d, *backup_dend = dend;
+                   length = wcslen(workp);
+
+                   /* If wcscoll(the collating symbol, whole string) > 0,
+                      any substring of the string never match with the
+                      collating symbol.  */
+                   if (wcscoll(workp, d) > 0)
+                     {
+                       workp += length + 1;
+                       break;
+                     }
+
+                   /* First, we compare the equivalence class with
+                      the first character of the string.
+                      If it don't match, we add the next character to
+                      the compare buffer in turn.  */
+                   for (i = 0 ; i < WORK_BUFFER_SIZE - 1 ; i++, d++)
+                     {
+                       int match;
+                       if (d == dend)
+                         {
+                           if (dend == end_match_2)
+                             break;
+                           d = string2;
+                           dend = end_match_2;
+                         }
+
+                       /* add next character to the compare buffer.  */
+                       str_buf[i] = TRANSLATE(*d);
+                       str_buf[i+1] = '\0';
+
+                       match = wcscoll(workp, str_buf);
+
+                       if (match == 0)
+                         goto char_set_matched;
+
+                       if (match < 0)
+                       /* (str_buf > workp) indicate (str_buf + X > workp),
+                          because for all X (str_buf + X > str_buf).
+                          So we don't need continue this loop.  */
+                         break;
+
+                       /* Otherwise(str_buf < workp),
+                          (str_buf+next_character) may equals (workp).
+                          So we continue this loop.  */
+                     }
+                   /* not matched */
+                   d = backup_d;
+                   dend = backup_dend;
+                   workp += length + 1;
+                 }
+             }
+
+            /* match with char_range?  */
+#ifdef _LIBC
+           if (nrules != 0)
+             {
+               uint32_t collseqval;
+               const char *collseq = (const char *)
+                 _NL_CURRENT(LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+
+               collseqval = collseq_table_lookup (collseq, c);
+
+               for (; workp < p - chars_length ;)
+                 {
+                   uint32_t start_val, end_val;
+
+                   /* We already compute the collation sequence value
+                      of the characters (or collating symbols).  */
+                   start_val = (uint32_t) *workp++; /* range_start */
+                   end_val = (uint32_t) *workp++; /* range_end */
+
+                   if (start_val <= collseqval && collseqval <= end_val)
+                     goto char_set_matched;
+                 }
+             }
+           else
+#endif
+             {
+               /* We set range_start_char at str_buf[0], range_end_char
+                  at str_buf[4], and compared char at str_buf[2].  */
+               str_buf[1] = 0;
+               str_buf[2] = c;
+               str_buf[3] = 0;
+               str_buf[5] = 0;
+               for (; workp < p - chars_length ;)
+                 {
+                   wchar_t *range_start_char, *range_end_char;
+
+                   /* match if (range_start_char <= c <= range_end_char).  */
+
+                   /* If range_start(or end) < 0, we assume -range_start(end)
+                      is the offset of the collating symbol which is specified
+                      as the character of the range start(end).  */
+
+                   /* range_start */
+                   if (*workp < 0)
+                     range_start_char = charset_top - (*workp++);
+                   else
+                     {
+                       str_buf[0] = *workp++;
+                       range_start_char = str_buf;
+                     }
+
+                   /* range_end */
+                   if (*workp < 0)
+                     range_end_char = charset_top - (*workp++);
+                   else
+                     {
+                       str_buf[4] = *workp++;
+                       range_end_char = str_buf + 4;
+                     }
+
+                   if (wcscoll(range_start_char, str_buf+2) <= 0 &&
+                       wcscoll(str_buf+2, range_end_char) <= 0)
+
+                     goto char_set_matched;
+                 }
+             }
+
+            /* match with char?  */
+           for (; workp < p ; workp++)
+             if (c == *workp)
+               goto char_set_matched;
+
+           not = !not;
+
+         char_set_matched:
+           if (not) goto fail;
+#else
+            /* Cast to `unsigned' instead of `unsigned char' in case the
+               bit list is a full 32 bytes long.  */
+           if (c < (unsigned) (*p * BYTEWIDTH)
+               && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+             not = !not;
+
+           p += 1 + *p;
+
+           if (!not) goto fail;
+#undef WORK_BUFFER_SIZE
+#endif /* WCHAR */
+           SET_REGS_MATCHED ();
+            d++;
+           break;
+         }
+
+
+        /* The beginning of a group is represented by start_memory.
+           The arguments are the register number in the next byte, and the
+           number of groups inner to this one in the next.  The text
+           matched within the group is recorded (in the internal
+           registers data structure) under the register number.  */
+        case start_memory:
+         DEBUG_PRINT3 ("EXECUTING start_memory %ld (%ld):\n",
+                       (long int) *p, (long int) p[1]);
+
+          /* Find out if this group can match the empty string.  */
+         p1 = p;               /* To send to group_match_null_string_p.  */
+
+          if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
+            REG_MATCH_NULL_STRING_P (reg_info[*p])
+              = PREFIX(group_match_null_string_p) (&p1, pend, reg_info);
+
+          /* Save the position in the string where we were the last time
+             we were at this open-group operator in case the group is
+             operated upon by a repetition operator, e.g., with `(a*)*b'
+             against `ab'; then we want to ignore where we are now in
+             the string in case this attempt to match fails.  */
+          old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
+                             ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
+                             : regstart[*p];
+         DEBUG_PRINT2 ("  old_regstart: %d\n",
+                        POINTER_TO_OFFSET (old_regstart[*p]));
+
+          regstart[*p] = d;
+         DEBUG_PRINT2 ("  regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));
+
+          IS_ACTIVE (reg_info[*p]) = 1;
+          MATCHED_SOMETHING (reg_info[*p]) = 0;
+
+         /* Clear this whenever we change the register activity status.  */
+         set_regs_matched_done = 0;
+
+          /* This is the new highest active register.  */
+          highest_active_reg = *p;
+
+          /* If nothing was active before, this is the new lowest active
+             register.  */
+          if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
+            lowest_active_reg = *p;
+
+          /* Move past the register number and inner group count.  */
+          p += 2;
+         just_past_start_mem = p;
+
+          break;
+
+
+        /* The stop_memory opcode represents the end of a group.  Its
+           arguments are the same as start_memory's: the register
+           number, and the number of inner groups.  */
+       case stop_memory:
+         DEBUG_PRINT3 ("EXECUTING stop_memory %ld (%ld):\n",
+                       (long int) *p, (long int) p[1]);
+
+          /* We need to save the string position the last time we were at
+             this close-group operator in case the group is operated
+             upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
+             against `aba'; then we want to ignore where we are now in
+             the string in case this attempt to match fails.  */
+          old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
+                           ? REG_UNSET (regend[*p]) ? d : regend[*p]
+                          : regend[*p];
+         DEBUG_PRINT2 ("      old_regend: %d\n",
+                        POINTER_TO_OFFSET (old_regend[*p]));
+
+          regend[*p] = d;
+         DEBUG_PRINT2 ("      regend: %d\n", POINTER_TO_OFFSET (regend[*p]));
+
+          /* This register isn't active anymore.  */
+          IS_ACTIVE (reg_info[*p]) = 0;
+
+         /* Clear this whenever we change the register activity status.  */
+         set_regs_matched_done = 0;
+
+          /* If this was the only register active, nothing is active
+             anymore.  */
+          if (lowest_active_reg == highest_active_reg)
+            {
+              lowest_active_reg = NO_LOWEST_ACTIVE_REG;
+              highest_active_reg = NO_HIGHEST_ACTIVE_REG;
+            }
+          else
+            { /* We must scan for the new highest active register, since
+                 it isn't necessarily one less than now: consider
+                 (a(b)c(d(e)f)g).  When group 3 ends, after the f), the
+                 new highest active register is 1.  */
+              UCHAR_T r = *p - 1;
+              while (r > 0 && !IS_ACTIVE (reg_info[r]))
+                r--;
+
+              /* If we end up at register zero, that means that we saved
+                 the registers as the result of an `on_failure_jump', not
+                 a `start_memory', and we jumped to past the innermost
+                 `stop_memory'.  For example, in ((.)*) we save
+                 registers 1 and 2 as a result of the *, but when we pop
+                 back to the second ), we are at the stop_memory 1.
+                 Thus, nothing is active.  */
+             if (r == 0)
+                {
+                  lowest_active_reg = NO_LOWEST_ACTIVE_REG;
+                  highest_active_reg = NO_HIGHEST_ACTIVE_REG;
+                }
+              else
+                highest_active_reg = r;
+            }
+
+          /* If just failed to match something this time around with a
+             group that's operated on by a repetition operator, try to
+             force exit from the ``loop'', and restore the register
+             information for this group that we had before trying this
+             last match.  */
+          if ((!MATCHED_SOMETHING (reg_info[*p])
+               || just_past_start_mem == p - 1)
+             && (p + 2) < pend)
+            {
+              boolean is_a_jump_n = false;
+
+              p1 = p + 2;
+              mcnt = 0;
+              switch ((re_opcode_t) *p1++)
+                {
+                  case jump_n:
+                   is_a_jump_n = true;
+                  case pop_failure_jump:
+                 case maybe_pop_jump:
+                 case jump:
+                 case dummy_failure_jump:
+                    EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+                   if (is_a_jump_n)
+                     p1 += OFFSET_ADDRESS_SIZE;
+                    break;
+
+                  default:
+                    /* do nothing */ ;
+                }
+             p1 += mcnt;
+
+              /* If the next operation is a jump backwards in the pattern
+                to an on_failure_jump right before the start_memory
+                 corresponding to this stop_memory, exit from the loop
+                 by forcing a failure after pushing on the stack the
+                 on_failure_jump's jump in the pattern, and d.  */
+              if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
+                  && (re_opcode_t) p1[1+OFFSET_ADDRESS_SIZE] == start_memory
+                 && p1[2+OFFSET_ADDRESS_SIZE] == *p)
+               {
+                  /* If this group ever matched anything, then restore
+                     what its registers were before trying this last
+                     failed match, e.g., with `(a*)*b' against `ab' for
+                     regstart[1], and, e.g., with `((a*)*(b*)*)*'
+                     against `aba' for regend[3].
+
+                     Also restore the registers for inner groups for,
+                     e.g., `((a*)(b*))*' against `aba' (register 3 would
+                     otherwise get trashed).  */
+
+                  if (EVER_MATCHED_SOMETHING (reg_info[*p]))
+                   {
+                     unsigned r;
+
+                      EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;
+
+                     /* Restore this and inner groups' (if any) registers.  */
+                      for (r = *p; r < (unsigned) *p + (unsigned) *(p + 1);
+                          r++)
+                        {
+                          regstart[r] = old_regstart[r];
+
+                          /* xx why this test?  */
+                          if (old_regend[r] >= regstart[r])
+                            regend[r] = old_regend[r];
+                        }
+                    }
+                 p1++;
+                  EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+                  PUSH_FAILURE_POINT (p1 + mcnt, d, -2);
+
+                  goto fail;
+                }
+            }
+
+          /* Move past the register number and the inner group count.  */
+          p += 2;
+          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 const CHAR_T *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];
+
+            /* 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 (translate
+                    ? PREFIX(bcmp_translate) (d, d2, mcnt, translate)
+                    : memcmp (d, d2, mcnt*sizeof(UCHAR_T)))
+                 goto fail;
+               d += mcnt, d2 += mcnt;
+
+               /* Do this because we've match some characters.  */
+               SET_REGS_MATCHED ();
+             }
+         }
+         break;
+
+
+        /* begline matches the empty string at the beginning of the string
+           (unless `not_bol' is set in `bufp'), and, if
+           `newline_anchor' is set, after newlines.  */
+       case begline:
+          DEBUG_PRINT1 ("EXECUTING begline.\n");
+
+          if (AT_STRINGS_BEG (d))
+            {
+              if (!bufp->not_bol) break;
+            }
+          else if (d[-1] == '\n' && bufp->newline_anchor)
+            {
+              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;
+            }
+
+          /* We have to ``prefetch'' the next character.  */
+          else if ((d == end1 ? *string2 : *d) == '\n'
+                   && bufp->newline_anchor)
+            {
+              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:
+          DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");
+
+          EXTRACT_NUMBER_AND_INCR (mcnt, p);
+#ifdef _LIBC
+          DEBUG_PRINT3 (" %d (to %p):\n", mcnt, p + mcnt);
+#else
+          DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
+#endif
+
+          PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
+          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:
+        on_failure:
+          DEBUG_PRINT1 ("EXECUTING on_failure_jump");
+
+          EXTRACT_NUMBER_AND_INCR (mcnt, p);
+#ifdef _LIBC
+          DEBUG_PRINT3 (" %d (to %p)", mcnt, p + mcnt);
+#else
+          DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
+#endif
+
+          /* If this on_failure_jump comes right before a group (i.e.,
+             the original * applied to a group), save the information
+             for that group and all inner ones, so that if we fail back
+             to this point, the group's information will be correct.
+             For example, in \(a*\)*\1, we need the preceding group,
+             and in \(zz\(a*\)b*\)\2, we need the inner group.  */
+
+          /* We can't use `p' to check ahead because we push
+             a failure point to `p + mcnt' after we do this.  */
+          p1 = p;
+
+          /* We need to skip no_op's before we look for the
+             start_memory in case this on_failure_jump is happening as
+             the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
+             against aba.  */
+          while (p1 < pend && (re_opcode_t) *p1 == no_op)
+            p1++;
+
+          if (p1 < pend && (re_opcode_t) *p1 == start_memory)
+            {
+              /* We have a new highest active register now.  This will
+                 get reset at the start_memory we are about to get to,
+                 but we will have saved all the registers relevant to
+                 this repetition op, as described above.  */
+              highest_active_reg = *(p1 + 1) + *(p1 + 2);
+              if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
+                lowest_active_reg = *(p1 + 1);
+            }
+
+          DEBUG_PRINT1 (":\n");
+          PUSH_FAILURE_POINT (p + mcnt, d, -2);
+          break;
+
+
+        /* A smart repeat ends with `maybe_pop_jump'.
+          We change it to either `pop_failure_jump' or `jump'.  */
+        case maybe_pop_jump:
+          EXTRACT_NUMBER_AND_INCR (mcnt, p);
+          DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
+          {
+           register UCHAR_T *p2 = p;
+
+            /* 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 change to pop_failure_jump, because we'll
+               never have to backtrack.
+
+               This is not true in the case of alternatives: in
+               `(a|ab)*' we do need to backtrack to the `ab' alternative
+               (e.g., if the string was `ab').  But instead of trying to
+               detect that here, the alternative has put on a dummy
+               failure point which is what we will end up popping.  */
+
+           /* 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.  */
+           while (1)
+             {
+               if (p2 + 2 < pend
+                   && ((re_opcode_t) *p2 == stop_memory
+                       || (re_opcode_t) *p2 == start_memory))
+                 p2 += 3;
+               else if (p2 + 2 + 2 * OFFSET_ADDRESS_SIZE < pend
+                        && (re_opcode_t) *p2 == dummy_failure_jump)
+                 p2 += 2 + 2 * OFFSET_ADDRESS_SIZE;
+               else
+                 break;
+             }
+
+           p1 = p + mcnt;
+           /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
+              to the `maybe_finalize_jump' of this case.  Examine what
+              follows.  */
+
+            /* If we're at the end of the pattern, we can change.  */
+            if (p2 == pend)
+             {
+               /* Consider what happens when matching ":\(.*\)"
+                  against ":/".  I don't really understand this code
+                  yet.  */
+               p[-(1+OFFSET_ADDRESS_SIZE)] = (UCHAR_T)
+                 pop_failure_jump;
+                DEBUG_PRINT1
+                  ("  End of pattern: change to `pop_failure_jump'.\n");
+              }
+
+            else if ((re_opcode_t) *p2 == exactn
+#ifdef MBS_SUPPORT
+                    || (re_opcode_t) *p2 == exactn_bin
+#endif
+                    || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
+             {
+               register UCHAR_T c
+                  = *p2 == (UCHAR_T) endline ? '\n' : p2[2];
+
+                if (((re_opcode_t) p1[1+OFFSET_ADDRESS_SIZE] == exactn
+#ifdef MBS_SUPPORT
+                    || (re_opcode_t) p1[1+OFFSET_ADDRESS_SIZE] == exactn_bin
+#endif
+                   ) && p1[3+OFFSET_ADDRESS_SIZE] != c)
+                  {
+                   p[-(1+OFFSET_ADDRESS_SIZE)] = (UCHAR_T)
+                     pop_failure_jump;
+#ifdef WCHAR
+                     DEBUG_PRINT3 ("  %C != %C => pop_failure_jump.\n",
+                                   (wint_t) c,
+                                   (wint_t) p1[3+OFFSET_ADDRESS_SIZE]);
+#else
+                     DEBUG_PRINT3 ("  %c != %c => pop_failure_jump.\n",
+                                   (char) c,
+                                   (char) p1[3+OFFSET_ADDRESS_SIZE]);
+#endif
+                  }
+
+#ifndef WCHAR
+               else if ((re_opcode_t) p1[3] == charset
+                        || (re_opcode_t) p1[3] == charset_not)
+                 {
+                   int not = (re_opcode_t) p1[3] == charset_not;
+
+                   if (c < (unsigned) (p1[4] * BYTEWIDTH)
+                       && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+                     not = !not;
+
+                    /* `not' is equal to 1 if c would match, which means
+                        that we can't change to pop_failure_jump.  */
+                   if (!not)
+                      {
+                       p[-3] = (unsigned char) pop_failure_jump;
+                        DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
+                      }
+                 }
+#endif /* not WCHAR */
+             }
+#ifndef WCHAR
+            else if ((re_opcode_t) *p2 == charset)
+             {
+               /* We win if the first character of the loop is not part
+                   of the charset.  */
+                if ((re_opcode_t) p1[3] == exactn
+                   && ! ((int) p2[1] * BYTEWIDTH > (int) p1[5]
+                         && (p2[2 + p1[5] / BYTEWIDTH]
+                             & (1 << (p1[5] % BYTEWIDTH)))))
+                 {
+                   p[-3] = (unsigned char) pop_failure_jump;
+                   DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
+                  }
+
+               else if ((re_opcode_t) p1[3] == 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 < (int) p1[4]
+                                && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
+                       break;
+
+                   if (idx == p2[1])
+                      {
+                       p[-3] = (unsigned char) pop_failure_jump;
+                        DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
+                      }
+                 }
+               else if ((re_opcode_t) p1[3] == 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 < (int) p1[4];
+                        idx++)
+                     if ((p2[2 + idx] & p1[5 + idx]) != 0)
+                       break;
+
+                   if (idx == p2[1] || idx == p1[4])
+                      {
+                       p[-3] = (unsigned char) pop_failure_jump;
+                        DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
+                      }
+                 }
+             }
+#endif /* not WCHAR */
+         }
+         p -= OFFSET_ADDRESS_SIZE;     /* Point at relative address again.  */
+         if ((re_opcode_t) p[-1] != pop_failure_jump)
+           {
+             p[-1] = (UCHAR_T) jump;
+              DEBUG_PRINT1 ("  Match => jump.\n");
+             goto unconditional_jump;
+           }
+        /* Note fall through.  */
+
+
+       /* The end of a simple repeat has a pop_failure_jump back to
+           its matching on_failure_jump, where the latter will push a
+           failure point.  The pop_failure_jump takes off failure
+           points put on by this pop_failure_jump's matching
+           on_failure_jump; we got through the pattern to here from the
+           matching on_failure_jump, so didn't fail.  */
+        case pop_failure_jump:
+          {
+            /* We need to pass separate storage for the lowest and
+               highest registers, even though we don't care about the
+               actual values.  Otherwise, we will restore only one
+               register from the stack, since lowest will == highest in
+               `pop_failure_point'.  */
+            active_reg_t dummy_low_reg, dummy_high_reg;
+            UCHAR_T *pdummy = NULL;
+            const CHAR_T *sdummy = NULL;
+
+            DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
+            POP_FAILURE_POINT (sdummy, pdummy,
+                               dummy_low_reg, dummy_high_reg,
+                               reg_dummy, reg_dummy, reg_info_dummy);
+          }
+         /* Note fall through.  */
+
+       unconditional_jump:
+#ifdef _LIBC
+         DEBUG_PRINT2 ("\n%p: ", p);
+#else
+         DEBUG_PRINT2 ("\n0x%x: ", p);
+#endif
+          /* Note fall through.  */
+
+        /* Unconditionally jump (without popping any failure points).  */
+        case jump:
+         EXTRACT_NUMBER_AND_INCR (mcnt, p);    /* Get the amount to jump.  */
+          DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
+         p += mcnt;                            /* Do the jump.  */
+#ifdef _LIBC
+          DEBUG_PRINT2 ("(to %p).\n", p);
+#else
+          DEBUG_PRINT2 ("(to 0x%x).\n", p);
+#endif
+         break;
+
+
+        /* We need this opcode so we can detect where alternatives end
+           in `group_match_null_string_p' et al.  */
+        case jump_past_alt:
+          DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
+          goto unconditional_jump;
+
+
+        /* Normally, the on_failure_jump pushes a failure point, which
+           then gets popped at pop_failure_jump.  We will end up at
+           pop_failure_jump, also, and with a pattern of, say, `a+', we
+           are skipping over the on_failure_jump, so we have to push
+           something meaningless for pop_failure_jump to pop.  */
+        case dummy_failure_jump:
+          DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
+          /* It doesn't matter what we push for the string here.  What
+             the code at `fail' tests is the value for the pattern.  */
+          PUSH_FAILURE_POINT (NULL, NULL, -2);
+          goto unconditional_jump;
+
+
+        /* At the end of an alternative, we need to push a dummy failure
+           point in case we are followed by a `pop_failure_jump', because
+           we don't want the failure point for the alternative to be
+           popped.  For example, matching `(a|ab)*' against `aab'
+           requires that we match the `ab' alternative.  */
+        case push_dummy_failure:
+          DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
+          /* See comments just above at `dummy_failure_jump' about the
+             two zeroes.  */
+          PUSH_FAILURE_POINT (NULL, NULL, -2);
+          break;
+
+        /* Have to succeed matching what follows at least n times.
+           After that, handle like `on_failure_jump'.  */
+        case succeed_n:
+          EXTRACT_NUMBER (mcnt, p + OFFSET_ADDRESS_SIZE);
+          DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);
+
+          assert (mcnt >= 0);
+          /* Originally, this is how many times we HAVE to succeed.  */
+          if (mcnt > 0)
+            {
+               mcnt--;
+              p += OFFSET_ADDRESS_SIZE;
+               STORE_NUMBER_AND_INCR (p, mcnt);
+#ifdef _LIBC
+               DEBUG_PRINT3 ("  Setting %p to %d.\n", p - OFFSET_ADDRESS_SIZE
+                            , mcnt);
+#else
+               DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p - OFFSET_ADDRESS_SIZE
+                            , mcnt);
+#endif
+            }
+         else if (mcnt == 0)
+            {
+#ifdef _LIBC
+              DEBUG_PRINT2 ("  Setting two bytes from %p to no_op.\n",
+                           p + OFFSET_ADDRESS_SIZE);
+#else
+              DEBUG_PRINT2 ("  Setting two bytes from 0x%x to no_op.\n",
+                           p + OFFSET_ADDRESS_SIZE);
+#endif /* _LIBC */
+
+#ifdef WCHAR
+             p[1] = (UCHAR_T) no_op;
+#else
+             p[2] = (UCHAR_T) no_op;
+              p[3] = (UCHAR_T) no_op;
+#endif /* WCHAR */
+              goto on_failure;
+            }
+          break;
+
+        case jump_n:
+          EXTRACT_NUMBER (mcnt, p + OFFSET_ADDRESS_SIZE);
+          DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);
+
+          /* Originally, this is how many times we CAN jump.  */
+          if (mcnt)
+            {
+               mcnt--;
+               STORE_NUMBER (p + OFFSET_ADDRESS_SIZE, mcnt);
+
+#ifdef _LIBC
+               DEBUG_PRINT3 ("  Setting %p to %d.\n", p + OFFSET_ADDRESS_SIZE,
+                            mcnt);
+#else
+               DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p + OFFSET_ADDRESS_SIZE,
+                            mcnt);
+#endif /* _LIBC */
+              goto unconditional_jump;
+            }
+          /* If don't have to jump any more, skip over the rest of command.  */
+         else
+           p += 2 * OFFSET_ADDRESS_SIZE;
+          break;
+
+       case set_number_at:
+         {
+            DEBUG_PRINT1 ("EXECUTING set_number_at.\n");
+
+            EXTRACT_NUMBER_AND_INCR (mcnt, p);
+            p1 = p + mcnt;
+            EXTRACT_NUMBER_AND_INCR (mcnt, p);
+#ifdef _LIBC
+            DEBUG_PRINT3 ("  Setting %p to %d.\n", p1, mcnt);
+#else
+            DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p1, mcnt);
+#endif
+           STORE_NUMBER (p1, mcnt);
+            break;
+          }
+
+#if 0
+       /* 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.  */
+
+       case wordbound:
+         DEBUG_PRINT1 ("EXECUTING wordbound.\n");
+         if (AT_WORD_BOUNDARY (d))
+           break;
+         goto fail;
+
+       case notwordbound:
+         DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
+         if (AT_WORD_BOUNDARY (d))
+           goto fail;
+         break;
+#else
+       case wordbound:
+       {
+         boolean prevchar, thischar;
+
+         DEBUG_PRINT1 ("EXECUTING wordbound.\n");
+         if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
+           break;
+
+         prevchar = WORDCHAR_P (d - 1);
+         thischar = WORDCHAR_P (d);
+         if (prevchar != thischar)
+           break;
+         goto fail;
+       }
+
+      case notwordbound:
+       {
+         boolean prevchar, thischar;
+
+         DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
+         if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
+           goto fail;
+
+         prevchar = WORDCHAR_P (d - 1);
+         thischar = WORDCHAR_P (d);
+         if (prevchar != thischar)
+           goto fail;
+         break;
+       }
+#endif
+
+       case wordbeg:
+          DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
+         if (!AT_STRINGS_END (d) && WORDCHAR_P (d)
+             && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
+           break;
+          goto fail;
+
+       case wordend:
+          DEBUG_PRINT1 ("EXECUTING wordend.\n");
+         if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
+              && (AT_STRINGS_END (d) || !WORDCHAR_P (d)))
+           break;
+          goto fail;
+
+#ifdef emacs
+       case before_dot:
+          DEBUG_PRINT1 ("EXECUTING before_dot.\n");
+         if (PTR_CHAR_POS ((unsigned char *) d) >= point)
+           goto fail;
+         break;
+
+       case at_dot:
+          DEBUG_PRINT1 ("EXECUTING at_dot.\n");
+         if (PTR_CHAR_POS ((unsigned char *) d) != point)
+           goto fail;
+         break;
+
+       case after_dot:
+          DEBUG_PRINT1 ("EXECUTING after_dot.\n");
+          if (PTR_CHAR_POS ((unsigned char *) d) <= point)
+           goto fail;
+         break;
+
+       case syntaxspec:
+          DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
+         mcnt = *p++;
+         goto matchsyntax;
+
+        case wordchar:
+          DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
+         mcnt = (int) Sword;
+        matchsyntax:
+         PREFETCH ();
+         /* Can't use *d++ here; SYNTAX may be an unsafe macro.  */
+         d++;
+         if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
+           goto fail;
+          SET_REGS_MATCHED ();
+         break;
+
+       case notsyntaxspec:
+          DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
+         mcnt = *p++;
+         goto matchnotsyntax;
+
+        case notwordchar:
+          DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
+         mcnt = (int) Sword;
+        matchnotsyntax:
+         PREFETCH ();
+         /* Can't use *d++ here; SYNTAX may be an unsafe macro.  */
+         d++;
+         if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
+           goto fail;
+         SET_REGS_MATCHED ();
+          break;
+
+#else /* not emacs */
+       case wordchar:
+          DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
+         PREFETCH ();
+          if (!WORDCHAR_P (d))
+            goto fail;
+         SET_REGS_MATCHED ();
+          d++;
+         break;
+
+       case notwordchar:
+          DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
+         PREFETCH ();
+         if (WORDCHAR_P (d))
+            goto fail;
+          SET_REGS_MATCHED ();
+          d++;
+         break;
+#endif /* not emacs */
+
+        default:
+          abort ();
+       }
+      continue;  /* Successfully executed one pattern command; keep going.  */
+
+
+    /* We goto here if a matching operation fails. */
+    fail:
+      if (!FAIL_STACK_EMPTY ())
+       { /* A restart point is known.  Restore to that state.  */
+          DEBUG_PRINT1 ("\nFAIL:\n");
+          POP_FAILURE_POINT (d, p,
+                             lowest_active_reg, highest_active_reg,
+                             regstart, regend, reg_info);
+
+          /* If this failure point is a dummy, try the next one.  */
+          if (!p)
+           goto fail;
+
+          /* If we failed to the end of the pattern, don't examine *p.  */
+         assert (p <= pend);
+          if (p < pend)
+            {
+              boolean is_a_jump_n = false;
+
+              /* If failed to a backwards jump that's part of a repetition
+                 loop, need to pop this failure point and use the next one.  */
+              switch ((re_opcode_t) *p)
+                {
+                case jump_n:
+                  is_a_jump_n = true;
+                case maybe_pop_jump:
+                case pop_failure_jump:
+                case jump:
+                  p1 = p + 1;
+                  EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+                  p1 += mcnt;
+
+                  if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
+                      || (!is_a_jump_n
+                          && (re_opcode_t) *p1 == on_failure_jump))
+                    goto fail;
+                  break;
+                default:
+                  /* do nothing */ ;
+                }
+            }
+
+          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 */
+\f
+/* Subroutine definitions for re_match_2.  */
+
+
+/* We are passed P pointing to a register number after a start_memory.
+
+   Return true if the pattern up to the corresponding stop_memory can
+   match the empty string, and false otherwise.
+
+   If we find the matching stop_memory, sets P to point to one past its number.
+   Otherwise, sets P to an undefined byte less than or equal to END.
+
+   We don't handle duplicates properly (yet).  */
+
+static boolean
+PREFIX(group_match_null_string_p) (p, end, reg_info)
+    UCHAR_T **p, *end;
+    PREFIX(register_info_type) *reg_info;
+{
+  int mcnt;
+  /* Point to after the args to the start_memory.  */
+  UCHAR_T *p1 = *p + 2;
+
+  while (p1 < end)
+    {
+      /* Skip over opcodes that can match nothing, and return true or
+        false, as appropriate, when we get to one that can't, or to the
+         matching stop_memory.  */
+
+      switch ((re_opcode_t) *p1)
+        {
+        /* Could be either a loop or a series of alternatives.  */
+        case on_failure_jump:
+          p1++;
+          EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+
+          /* If the next operation is not a jump backwards in the
+            pattern.  */
+
+         if (mcnt >= 0)
+           {
+              /* Go through the on_failure_jumps of the alternatives,
+                 seeing if any of the alternatives cannot match nothing.
+                 The last alternative starts with only a jump,
+                 whereas the rest start with on_failure_jump and end
+                 with a jump, e.g., here is the pattern for `a|b|c':
+
+                 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
+                 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
+                 /exactn/1/c
+
+                 So, we have to first go through the first (n-1)
+                 alternatives and then deal with the last one separately.  */
+
+
+              /* Deal with the first (n-1) alternatives, which start
+                 with an on_failure_jump (see above) that jumps to right
+                 past a jump_past_alt.  */
+
+              while ((re_opcode_t) p1[mcnt-(1+OFFSET_ADDRESS_SIZE)] ==
+                    jump_past_alt)
+                {
+                  /* `mcnt' holds how many bytes long the alternative
+                     is, including the ending `jump_past_alt' and
+                     its number.  */
+
+                  if (!PREFIX(alt_match_null_string_p) (p1, p1 + mcnt -
+                                               (1 + OFFSET_ADDRESS_SIZE),
+                                               reg_info))
+                    return false;
+
+                  /* Move to right after this alternative, including the
+                    jump_past_alt.  */
+                  p1 += mcnt;
+
+                  /* Break if it's the beginning of an n-th alternative
+                     that doesn't begin with an on_failure_jump.  */
+                  if ((re_opcode_t) *p1 != on_failure_jump)
+                    break;
+
+                 /* Still have to check that it's not an n-th
+                    alternative that starts with an on_failure_jump.  */
+                 p1++;
+                  EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+                  if ((re_opcode_t) p1[mcnt-(1+OFFSET_ADDRESS_SIZE)] !=
+                     jump_past_alt)
+                    {
+                     /* Get to the beginning of the n-th alternative.  */
+                      p1 -= 1 + OFFSET_ADDRESS_SIZE;
+                      break;
+                    }
+                }
+
+              /* Deal with the last alternative: go back and get number
+                 of the `jump_past_alt' just before it.  `mcnt' contains
+                 the length of the alternative.  */
+              EXTRACT_NUMBER (mcnt, p1 - OFFSET_ADDRESS_SIZE);
+
+              if (!PREFIX(alt_match_null_string_p) (p1, p1 + mcnt, reg_info))
+                return false;
+
+              p1 += mcnt;      /* Get past the n-th alternative.  */
+            } /* if mcnt > 0 */
+          break;
+
+
+        case stop_memory:
+         assert (p1[1] == **p);
+          *p = p1 + 2;
+          return true;
+
+
+        default:
+          if (!PREFIX(common_op_match_null_string_p) (&p1, end, reg_info))
+            return false;
+        }
+    } /* while p1 < end */
+
+  return false;
+} /* group_match_null_string_p */
+
+
+/* Similar to group_match_null_string_p, but doesn't deal with alternatives:
+   It expects P to be the first byte of a single alternative and END one
+   byte past the last. The alternative can contain groups.  */
+
+static boolean
+PREFIX(alt_match_null_string_p) (p, end, reg_info)
+    UCHAR_T *p, *end;
+    PREFIX(register_info_type) *reg_info;
+{
+  int mcnt;
+  UCHAR_T *p1 = p;
+
+  while (p1 < end)
+    {
+      /* Skip over opcodes that can match nothing, and break when we get
+         to one that can't.  */
+
+      switch ((re_opcode_t) *p1)
+        {
+       /* It's a loop.  */
+        case on_failure_jump:
+          p1++;
+          EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+          p1 += mcnt;
+          break;
+
+       default:
+          if (!PREFIX(common_op_match_null_string_p) (&p1, end, reg_info))
+            return false;
+        }
+    }  /* while p1 < end */
+
+  return true;
+} /* alt_match_null_string_p */
+
+
+/* Deals with the ops common to group_match_null_string_p and
+   alt_match_null_string_p.
+
+   Sets P to one after the op and its arguments, if any.  */
+
+static boolean
+PREFIX(common_op_match_null_string_p) (p, end, reg_info)
+    UCHAR_T **p, *end;
+    PREFIX(register_info_type) *reg_info;
+{
+  int mcnt;
+  boolean ret;
+  int reg_no;
+  UCHAR_T *p1 = *p;
+
+  switch ((re_opcode_t) *p1++)
+    {
+    case no_op:
+    case begline:
+    case endline:
+    case begbuf:
+    case endbuf:
+    case wordbeg:
+    case wordend:
+    case wordbound:
+    case notwordbound:
+#ifdef emacs
+    case before_dot:
+    case at_dot:
+    case after_dot:
+#endif
+      break;
+
+    case start_memory:
+      reg_no = *p1;
+      assert (reg_no > 0 && reg_no <= MAX_REGNUM);
+      ret = PREFIX(group_match_null_string_p) (&p1, end, reg_info);
+
+      /* Have to set this here in case we're checking a group which
+         contains a group and a back reference to it.  */
+
+      if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
+        REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;
+
+      if (!ret)
+        return false;
+      break;
+
+    /* If this is an optimized succeed_n for zero times, make the jump.  */
+    case jump:
+      EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+      if (mcnt >= 0)
+        p1 += mcnt;
+      else
+        return false;
+      break;
+
+    case succeed_n:
+      /* Get to the number of times to succeed.  */
+      p1 += OFFSET_ADDRESS_SIZE;
+      EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+
+      if (mcnt == 0)
+        {
+          p1 -= 2 * OFFSET_ADDRESS_SIZE;
+          EXTRACT_NUMBER_AND_INCR (mcnt, p1);
+          p1 += mcnt;
+        }
+      else
+        return false;
+      break;
+
+    case duplicate:
+      if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
+        return false;
+      break;
+
+    case set_number_at:
+      p1 += 2 * OFFSET_ADDRESS_SIZE;
+
+    default:
+      /* All other opcodes mean we cannot match the empty string.  */
+      return false;
+  }
+
+  *p = p1;
+  return true;
+} /* common_op_match_null_string_p */
+
+
+/* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
+   bytes; nonzero otherwise.  */
+
+static int
+PREFIX(bcmp_translate) (s1, s2, len, translate)
+     const CHAR_T *s1, *s2;
+     register int len;
+     RE_TRANSLATE_TYPE translate;
+{
+  register const UCHAR_T *p1 = (const UCHAR_T *) s1;
+  register const UCHAR_T *p2 = (const UCHAR_T *) s2;
+  while (len)
+    {
+#ifdef WCHAR
+      if (((*p1<=0xff)?translate[*p1++]:*p1++)
+         != ((*p2<=0xff)?translate[*p2++]:*p2++))
+       return 1;
+#else /* BYTE */
+      if (translate[*p1++] != translate[*p2++]) return 1;
+#endif /* WCHAR */
+      len--;
+    }
+  return 0;
+}
+\f
+
+#else /* not INSIDE_RECURSION */
+
+/* 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;
+
+  /* Match anchors at newline.  */
+  bufp->newline_anchor = 1;
+
+# ifdef MBS_SUPPORT
+  if (MB_CUR_MAX != 1)
+    ret = wcs_regex_compile (pattern, length, re_syntax_options, bufp);
+  else
+# endif
+    ret = byte_regex_compile (pattern, length, re_syntax_options, bufp);
+
+  if (!ret)
+    return NULL;
+  return gettext (re_error_msgid + re_error_msgid_idx[(int) ret]);
+}
+#ifdef _LIBC
+weak_alias (__re_compile_pattern, re_compile_pattern)
+#endif
+\f
+/* 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)
+       return 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)
+        return (char *) gettext (re_error_msgid
+                                + re_error_msgid_idx[(int) REG_ESPACE]);
+      re_comp_buf.allocated = 200;
+
+      re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
+      if (re_comp_buf.fastmap == NULL)
+       return (char *) gettext (re_error_msgid
+                                + re_error_msgid_idx[(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.  */
+
+  /* Match anchors at newlines.  */
+  re_comp_buf.newline_anchor = 1;
+
+# ifdef MBS_SUPPORT
+  if (MB_CUR_MAX != 1)
+    ret = wcs_regex_compile (s, strlen (s), re_syntax_options, &re_comp_buf);
+  else
+# endif
+    ret = byte_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 + re_error_msgid_idx[(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 */
+\f
+/* 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;
+     `newline_anchor' to REG_NEWLINE being set in CFLAGS;
+     `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 *preg;
+    const char *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;
+      /* It also changes the matching behavior.  */
+      preg->newline_anchor = 1;
+    }
+  else
+    preg->newline_anchor = 0;
+
+  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.  */
+# ifdef MBS_SUPPORT
+  if (MB_CUR_MAX != 1)
+    ret = wcs_regex_compile (pattern, strlen (pattern), syntax, preg);
+  else
+# endif
+    ret = byte_regex_compile (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.  */
+      if (re_compile_fastmap (preg) == -2)
+       {
+         /* Some error occurred while computing the fastmap, just forget
+            about it.  */
+         free (preg->fastmap);
+         preg->fastmap = NULL;
+       }
+    }
+
+  return (int) ret;
+}
+#ifdef _LIBC
+weak_alias (__regcomp, regcomp)
+#endif
+
+
+/* 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 *preg;
+    const char *string;
+    size_t nmatch;
+    regmatch_t pmatch[];
+    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;
+
+  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;
+    }
+
+  /* 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;
+}
+#ifdef _LIBC
+weak_alias (__regexec, regexec)
+#endif
+
+
+/* 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 >= (int) (sizeof (re_error_msgid_idx)
+                          / sizeof (re_error_msgid_idx[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 + re_error_msgid_idx[errcode]);
+
+  msg_size = strlen (msg) + 1; /* Includes the null.  */
+
+  if (errbuf_size != 0)
+    {
+      if (msg_size > errbuf_size)
+        {
+#if defined HAVE_MEMPCPY || defined _LIBC
+         *((char *) __mempcpy (errbuf, msg, errbuf_size - 1)) = '\0';
+#else
+          memcpy (errbuf, msg, errbuf_size - 1);
+          errbuf[errbuf_size - 1] = 0;
+#endif
+        }
+      else
+        memcpy (errbuf, msg, msg_size);
+    }
+
+  return msg_size;
+}
+#ifdef _LIBC
+weak_alias (__regerror, regerror)
+#endif
+
+
+/* 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;
+}
+#ifdef _LIBC
+weak_alias (__regfree, regfree)
+#endif
+
+#endif /* not emacs  */
+
+#endif /* not INSIDE_RECURSION */
+
+\f
+#undef STORE_NUMBER
+#undef STORE_NUMBER_AND_INCR
+#undef EXTRACT_NUMBER
+#undef EXTRACT_NUMBER_AND_INCR
+
+#undef DEBUG_PRINT_COMPILED_PATTERN
+#undef DEBUG_PRINT_DOUBLE_STRING
+
+#undef INIT_FAIL_STACK
+#undef RESET_FAIL_STACK
+#undef DOUBLE_FAIL_STACK
+#undef PUSH_PATTERN_OP
+#undef PUSH_FAILURE_POINTER
+#undef PUSH_FAILURE_INT
+#undef PUSH_FAILURE_ELT
+#undef POP_FAILURE_POINTER
+#undef POP_FAILURE_INT
+#undef POP_FAILURE_ELT
+#undef DEBUG_PUSH
+#undef DEBUG_POP
+#undef PUSH_FAILURE_POINT
+#undef POP_FAILURE_POINT
+
+#undef REG_UNSET_VALUE
+#undef REG_UNSET
+
+#undef PATFETCH
+#undef PATFETCH_RAW
+#undef PATUNFETCH
+#undef TRANSLATE
+
+#undef INIT_BUF_SIZE
+#undef GET_BUFFER_SPACE
+#undef BUF_PUSH
+#undef BUF_PUSH_2
+#undef BUF_PUSH_3
+#undef STORE_JUMP
+#undef STORE_JUMP2
+#undef INSERT_JUMP
+#undef INSERT_JUMP2
+#undef EXTEND_BUFFER
+#undef GET_UNSIGNED_NUMBER
+#undef FREE_STACK_RETURN
+
+# undef POINTER_TO_OFFSET
+# undef MATCHING_IN_FRST_STRING
+# undef PREFETCH
+# undef AT_STRINGS_BEG
+# undef AT_STRINGS_END
+# undef WORDCHAR_P
+# undef FREE_VAR
+# undef FREE_VARIABLES
+# undef NO_HIGHEST_ACTIVE_REG
+# undef NO_LOWEST_ACTIVE_REG
+
+# undef CHAR_T
+# undef UCHAR_T
+# undef COMPILED_BUFFER_VAR
+# undef OFFSET_ADDRESS_SIZE
+# undef CHAR_CLASS_SIZE
+# undef PREFIX
+# undef ARG_PREFIX
+# undef PUT_CHAR
+# undef BYTE
+# undef WCHAR
+
+# define DEFINED_ONCE