text: /* 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) 1993-2017 Free Software Foundation, Inc.
     This file is part of the GNU C Library.
  
     The GNU C Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 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
     Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public
     License along with the GNU C Library; if not, write to the Free
     Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
     02110-1301 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. */
  /* AIX requires this to be the first thing in the file. */
  #if defined _AIX && !defined __GNUC__ && !defined REGEX_MALLOC
    #pragma alloca
  #endif
  
  #undef	_GNU_SOURCE
  #define _GNU_SOURCE
  
  #ifndef INSIDE_RECURSION
  # ifdef HAVE_CONFIG_H
  #  include <config.h>
  # endif
  #endif
  
  #include <ansidecl.h>
  
  #ifndef INSIDE_RECURSION
  
  # if defined STDC_HEADERS && !defined emacs
  #  include <stddef.h>
  #  define PTR_INT_TYPE ptrdiff_t
  # else
  /* We need this for `regex.h', and perhaps for the Emacs include files.  */
  #  include <sys/types.h>
  #  define PTR_INT_TYPE long
  # 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 && ENABLE_NLS) || 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)	((void) memset (s, '\0', n))
  #     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
  
  /* 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
  
  # 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 (void);
  
  static void
  init_syntax_once (void)
  {
     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 */
  
  /* Integer type for pointers.  */
  # if !defined _LIBC && !defined HAVE_UINTPTR_T
  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 (const char *pattern, size_t size,
                                           reg_syntax_t syntax,
                                           struct re_pattern_buffer *bufp);
  
  static int byte_re_match_2_internal (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 byte_re_search_2 (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 (struct re_pattern_buffer *bufp);
  
  #ifdef MBS_SUPPORT
  static reg_errcode_t wcs_regex_compile (const char *pattern, size_t size,
                                          reg_syntax_t syntax,
                                          struct re_pattern_buffer *bufp);
  
  
  static int wcs_re_match_2_internal (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 wcs_re_search_2 (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_compile_fastmap (struct re_pattern_buffer *bufp);
  #endif
  
  /* 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 */
  
  
  #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)
  #else
  # ifdef 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
  #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) += ((unsigned) SIGN_EXTEND_CHAR (*((source) + 1))) << 8; \
    } while (0)
  # endif
  
  # ifdef DEBUG
  static void PREFIX(extract_number) (int *dest, UCHAR_T *source);
  static void
  PREFIX(extract_number) (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) (int *destination,
                                               UCHAR_T **source);
  static void
  PREFIX(extract_number_and_incr) (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 */
  
  
  
  /* 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 (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) (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) (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) (const CHAR_T *where, const CHAR_T *string1,
                               int size1, const CHAR_T *string2, int size2)
  {
    int this_char;
  
    if (where == NULL)
      printf ("(null)");
    else
      {
        int cnt;
  
        if (FIRST_STRING_P (where))
          {
            for (this_char = where - string1; this_char < size1; this_char++)
  	    PUT_CHAR (string1[this_char]);
  
            where = string2;
          }
  
        cnt = 0;
        for (this_char = where - string2; this_char < size2; this_char++)
  	{
  	  PUT_CHAR (string2[this_char]);
  	  if (++cnt > 100)
  	    {
  	      fputs ("...", stdout);
  	      break;
  	    }
  	}
      }
  }
  
  #  ifndef DEFINED_ONCE
  void
  printchar (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 */
  
  
  
  # 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 (CHAR_T *dest, const unsigned char*src, size_t len,
                      int *offset_buffer, char *is_binary)
       /* 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}
       */
  {
    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)
      {
  #ifdef _LIBC
        consumed = __mbrtowc (pdest, psrc, mb_remain, &mbs);
  #else
        consumed = mbrtowc (pdest, psrc, mb_remain, &mbs);
  #endif
  
        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 (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
  
  /* This table gives an error message for each of the error codes listed
     in regex.h.  Obviously the order here has to be same as there.
     POSIX doesn't require that we do anything for REG_NOERROR,
     but why not be nice?  */
  
  static const char *re_error_msgid[] =
    {
      gettext_noop ("Success"),	/* REG_NOERROR */
      gettext_noop ("No match"),	/* REG_NOMATCH */
      gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
      gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
      gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
      gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
      gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
      gettext_noop ("Unmatched [ or [^"),	/* REG_EBRACK */
      gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
      gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
      gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
      gettext_noop ("Invalid range end"),	/* REG_ERANGE */
      gettext_noop ("Memory exhausted"), /* REG_ESPACE */
      gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
      gettext_noop ("Premature end of regular expression"), /* REG_EEND */
      gettext_noop ("Regular expression too big"), /* REG_ESIZE */
      gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
    };
  
  #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 */
  
  #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 */
  
  /* 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_opcode_t op, UCHAR_T *loc, int arg);
  static void PREFIX(store_op2) (re_opcode_t op, UCHAR_T *loc,
                                 int arg1, int arg2);
  static void PREFIX(insert_op1) (re_opcode_t op, UCHAR_T *loc,
                                  int arg, UCHAR_T *end);
  static void PREFIX(insert_op2) (re_opcode_t op, UCHAR_T *loc,
                                  int arg1, int arg2, UCHAR_T *end);
  static boolean PREFIX(at_begline_loc_p) (const CHAR_T *pattern,
                                           const CHAR_T *p,
                                           reg_syntax_t syntax);
  static boolean PREFIX(at_endline_loc_p) (const CHAR_T *p,
                                           const CHAR_T *pend,
                                           reg_syntax_t syntax);
  # ifdef WCHAR
  static reg_errcode_t wcs_compile_range (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 (int num, CHAR_T *loc, CHAR_T *end);
  # else /* BYTE */
  static reg_errcode_t byte_compile_range (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)] : (char) (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)				\
        {									\
  	PTR_INT_TYPE 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)				\
        {									\
  	PTR_INT_TYPE 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 */
  
  # 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) (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 */
  
  # ifndef DEFINED_ONCE
  static boolean group_in_compile_stack (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) (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;
  	  /* Fall through.  */
          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 (char_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) & ~3;
  
  				    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 through 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) (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) (re_opcode_t op, UCHAR_T *loc, int arg1, int 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) (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) (re_opcode_t op, UCHAR_T *loc, int arg1,
                      int 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) (const CHAR_T *pattern, const CHAR_T *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) (const CHAR_T *p, const CHAR_T *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_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 (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 (CHAR_T range_start_char, const CHAR_T **p_ptr,
                     const CHAR_T *pend, RE_TRANSLATE_TYPE translate,
                     reg_syntax_t syntax, CHAR_T *b, CHAR_T *char_set)
  {
    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 (unsigned int range_start_char, const char **p_ptr,
                      const char *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 */
  
  /* 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 (CHAR_T c)
  {
    unsigned char buf[MB_CUR_MAX];
    mbstate_t state;
    int retval;
    memset (&state, '\0', sizeof (state));
  # ifdef _LIBC
    retval = __wcrtomb (buf, c, &state);
  # else
    retval = wcrtomb (buf, c, &state);
  # endif
    return retval > 0 ? buf[0] : (unsigned char) c;
  }
  #endif /* WCHAR */
  
  static int
  PREFIX(re_compile_fastmap) (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 == (UCHAR_T) 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 (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
  
  
  /* 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 (struct re_pattern_buffer *bufp,
                    struct re_registers *regs, unsigned num_regs,
                    regoff_t *starts, regoff_t *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
  
  /* 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 (struct re_pattern_buffer *bufp, const char *string, int size,
             int startpos, int 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 (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)
  {
  # 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) free (var); var = NULL
  #endif
  
  #ifdef WCHAR
  # define MAX_ALLOCA_SIZE	2000
  
  # define FREE_WCS_BUFFERS() \
    do {									      \
      if (size1 > MAX_ALLOCA_SIZE)					      \
        {									      \
  	free (wcs_string1);						      \
  	free (mbs_offset1);						      \
        }									      \
      else								      \
        {									      \
  	FREE_VAR (wcs_string1);						      \
  	FREE_VAR (mbs_offset1);						      \
        }									      \
      if (size2 > MAX_ALLOCA_SIZE) 					      \
        {									      \
  	free (wcs_string2);						      \
  	free (mbs_offset2);						      \
        }									      \
      else								      \
        {									      \
  	FREE_VAR (wcs_string2);						      \
  	FREE_VAR (mbs_offset2);						      \
        }									      \
    } while (0)
  
  #endif
  
  
  static int
  PREFIX(re_search_2) (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)
  {
    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)
      {
        if (size1 > MAX_ALLOCA_SIZE)
  	{
  	  wcs_string1 = TALLOC (size1 + 1, CHAR_T);
  	  mbs_offset1 = TALLOC (size1 + 1, int);
  	  is_binary = TALLOC (size1 + 1, char);
  	}
        else
  	{
  	  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)
  	{
  	  if (size1 > MAX_ALLOCA_SIZE)
  	    {
  	      free (wcs_string1);
  	      free (mbs_offset1);
  	      free (is_binary);
  	    }
  	  else
  	    {
  	      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  */
        if (size1 > MAX_ALLOCA_SIZE)
  	free (is_binary);
        else
  	FREE_VAR (is_binary);
      }
    if (size2 != 0)
      {
        if (size2 > MAX_ALLOCA_SIZE)
  	{
  	  wcs_string2 = TALLOC (size2 + 1, CHAR_T);
  	  mbs_offset2 = TALLOC (size2 + 1, int);
  	  is_binary = TALLOC (size2 + 1, char);
  	}
        else
  	{
  	  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 ();
  	  if (size2 > MAX_ALLOCA_SIZE)
  	    free (is_binary);
  	  else
  	    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  */
        if (size2 > MAX_ALLOCA_SIZE)
  	free (is_binary);
        else
  	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		\
     || ((d) == end1 ? *string2						\
         : (d) == string2 - 1 ? *(end1 - 1) : *(d)) == L'_')
  #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)
  
  #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 (struct re_pattern_buffer *bufp, const char *string,
            int size, int 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) (UCHAR_T **p,
                                                    UCHAR_T *end,
  					PREFIX(register_info_type) *reg_info);
  static boolean PREFIX(alt_match_null_string_p) (UCHAR_T *p,
                                                  UCHAR_T *end,
  					PREFIX(register_info_type) *reg_info);
  static boolean PREFIX(common_op_match_null_string_p) (UCHAR_T **p,
                                                        UCHAR_T *end,
  					PREFIX(register_info_type) *reg_info);
  static int PREFIX(bcmp_translate) (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 (struct re_pattern_buffer *bufp, const char *string1, int size1,
              const char *string2, int 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 (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(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 (struct re_pattern_buffer *bufp,
                           const char *cstring1, int csize1,
                           const char *cstring2, int 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, int size1,
                           wchar_t *string2, int size2,
       /* offset buffer for optimizatoin. See convert_mbs_to_wc.  */
  			 int *mbs_offset1, int *mbs_offset2)
  #else /* BYTE */
  static int
  byte_re_match_2_internal (struct re_pattern_buffer *bufp,
                            const char *string1, int size1,
                            const char *string2, int 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;
  
  	      /* 1 if this match is the best seen so far.  */
  	      boolean best_match_p;
  
                same_str_p = (FIRST_STRING_P (match_end)
                              == MATCHING_IN_FIRST_STRING);
  
  	      /* 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 negate = (re_opcode_t) *(p - 1) == charset_not;
  
              DEBUG_PRINT2 ("EXECUTING charset%s.\n", negate ? "_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;
  # ifdef _LIBC
  		if (__iswctype((wint_t)c, wctype))
  		  goto char_set_matched;
  # else
  		if (iswctype((wint_t)c, wctype))
  		  goto char_set_matched;
  # endif
  	      }
  
              /* 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;
  # ifdef _LIBC
  		    length = __wcslen (workp);
  # else
  		    length = wcslen (workp);
  # endif
  
  		    /* If wcscoll(the collating symbol, whole string) > 0,
  		       any substring of the string never match with the
  		       collating symbol.  */
  # ifdef _LIBC
  		    if (__wcscoll (workp, d) > 0)
  # else
  		    if (wcscoll (workp, d) > 0)
  # endif
  		      {
  			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';
  
  # ifdef _LIBC
  			match = __wcscoll (workp, str_buf);
  # else
  			match = wcscoll (workp, str_buf);
  # endif
  			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;
  # ifdef _LIBC
  		    length = __wcslen (workp);
  # else
  		    length = wcslen (workp);
  # endif
  
  		    /* If wcscoll(the collating symbol, whole string) > 0,
  		       any substring of the string never match with the
  		       collating symbol.  */
  # ifdef _LIBC
  		    if (__wcscoll (workp, d) > 0)
  # else
  		    if (wcscoll (workp, d) > 0)
  # endif
  		      {
  			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';
  
  # ifdef _LIBC
  			match = __wcscoll (workp, str_buf);
  # else
  			match = wcscoll (workp, str_buf);
  # endif
  
  			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;
  		      }
  
  # ifdef _LIBC
  		    if (__wcscoll (range_start_char, str_buf+2) <= 0
  			&& __wcscoll (str_buf+2, range_end_char) <= 0)
  # else
  		    if (wcscoll (range_start_char, str_buf+2) <= 0
  			&& wcscoll (str_buf+2, range_end_char) <= 0)
  # endif
  		      goto char_set_matched;
  		  }
  	      }
  
              /* match with char?  */
  	    for (; workp < p ; workp++)
  	      if (c == *workp)
  		goto char_set_matched;
  
  	    negate = !negate;
  
  	  char_set_matched:
  	    if (negate) 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)))
  	      negate = !negate;
  
  	    p += 1 + *p;
  
  	    if (!negate) 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;
  		    /* Fall through.  */
                    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 negate = (re_opcode_t) p1[3] == charset_not;
  
  		    if (c < (unsigned) (p1[4] * BYTEWIDTH)
  			&& p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
  		      negate = !negate;
  
                      /* `negate' is equal to 1 if c would match, which means
                          that we can't change to pop_failure_jump.  */
  		    if (!negate)
                        {
    		        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;
  	    }
          /* 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 ATTRIBUTE_UNUSED = NULL;
              const CHAR_T *sdummy ATTRIBUTE_UNUSED = 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);
            }
  	  /* 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;
  		  /* Fall through.  */
                  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 */
  
  /* 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) (UCHAR_T **p, UCHAR_T *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) (UCHAR_T *p, UCHAR_T *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) (UCHAR_T **p, UCHAR_T *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;
        return false;
  
      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) (const CHAR_T *s1, const CHAR_T *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;
  }
  
  
  #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 (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[(int) ret]);
  }
  #ifdef _LIBC
  weak_alias (__re_compile_pattern, re_compile_pattern)
  #endif
  
  /* 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 (const char *s)
  {
    reg_errcode_t ret;
  
    if (!s)
      {
        if (!re_comp_buf.buffer)
  	return (char *) gettext ("No previous regular expression");
        return 0;
      }
  
    if (!re_comp_buf.buffer)
      {
        re_comp_buf.buffer = (unsigned char *) malloc (200);
        if (re_comp_buf.buffer == NULL)
          return (char *) gettext (re_error_msgid[(int) REG_ESPACE]);
        re_comp_buf.allocated = 200;
  
        re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH);
        if (re_comp_buf.fastmap == NULL)
  	return (char *) gettext (re_error_msgid[(int) REG_ESPACE]);
      }
  
    /* Since `re_exec' always passes NULL for the `regs' argument, we
       don't need to initialize the pattern buffer fields which affect it.  */
  
    /* 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[(int) ret]);
  }
  
  
  int
  #ifdef _LIBC
  weak_function
  #endif
  re_exec (const char *s)
  {
    const int len = strlen (s);
    return
      0 <= re_search (&re_comp_buf, s, len, 0, len, (struct re_registers *) 0);
  }
  
  #endif /* _REGEX_RE_COMP */
  
  /* POSIX.2 functions.  Don't define these for Emacs.  */
  
  #ifndef emacs
  
  /* regcomp takes a regular expression as a string and compiles it.
  
     PREG is a regex_t *.  We do not expect any fields to be initialized,
     since POSIX says we shouldn't.  Thus, we set
  
       `buffer' to the compiled pattern;
       `used' to the length of the compiled pattern;
       `syntax' to RE_SYNTAX_POSIX_EXTENDED if the
         REG_EXTENDED bit in CFLAGS is set; otherwise, to
         RE_SYNTAX_POSIX_BASIC;
       `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 (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)
      {
        int 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 (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 (int errcode, const regex_t *preg ATTRIBUTE_UNUSED,
            char *errbuf, size_t errbuf_size)
  {
    const char *msg;
    size_t msg_size;
  
    if (errcode < 0
        || errcode >= (int) (sizeof (re_error_msgid)
  			   / sizeof (re_error_msgid[0])))
      /* Only error codes returned by the rest of the code should be passed
         to this routine.  If we are given anything else, or if other regex
         code generates an invalid error code, then the program has a bug.
         Dump core so we can fix it.  */
      abort ();
  
    msg = gettext (re_error_msgid[errcode]);
  
    msg_size = strlen (msg) + 1; /* Includes the null.  */
  
    if (errbuf_size != 0)
      {
        if (msg_size > errbuf_size)
          {
  #if defined HAVE_MEMPCPY || defined _LIBC
  	  *((char *) mempcpy (errbuf, msg, errbuf_size - 1)) = '\0';
  #else
            (void) memcpy (errbuf, msg, errbuf_size - 1);
            errbuf[errbuf_size - 1] = 0;
  #endif
          }
        else
          (void) memcpy (errbuf, msg, msg_size);
      }
  
    return msg_size;
  }
  #ifdef _LIBC
  weak_alias (__regerror, regerror)
  #endif
  
  
  /* Free dynamically allocated space used by PREG.  */
  
  void
  regfree (regex_t *preg)
  {
    free (preg->buffer);
    preg->buffer = NULL;
  
    preg->allocated = 0;
    preg->used = 0;
  
    free (preg->fastmap);
    preg->fastmap = NULL;
    preg->fastmap_accurate = 0;
  
    free (preg->translate);
    preg->translate = NULL;
  }
  #ifdef _LIBC
  weak_alias (__regfree, regfree)
  #endif
  
  #endif /* not emacs  */
  
  #endif /* not INSIDE_RECURSION */
  
  
  #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
  