/lib/regex.c

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/*
 * regex.c -- POSIX-conformant regular expression function set for the lsof
 *	      library
 *
 * This file is used when the UNIX dialect does not have a POSIX-conformant
 * regular expression function set.  In that case USE_LIB_REGEX is defined.
 *
 * V. Abell <abe@purdue.edu>
 * Purdue University Computing Center
 */


/*
 * Copyright 2000 Purdue Research Foundation, West Lafayette, Indiana
 * 47907.  All rights reserved.
 *
 * Written by Victor A. Abell
 *
 * This software is not subject to any license of the American Telephone
 * and Telegraph Company or the Regents of the University of California.
 *
 * This software has been adapted from snprintf.c in sendmail 8.9.3.  It
 * is subject to the sendmail copyright statements listed below, and the
 * sendmail licensing terms stated in the sendmail LICENSE file comment
 * section of this file.
 *
 * Permission is granted to anyone to use this software for any purpose on
 * any computer system, and to alter it and redistribute it freely, subject
 * to the following restrictions:
 *
 * 1. Neither the authors nor Purdue University are responsible for any
 *    consequences of the use of this software.
 *
 * 2. The origin of this software must not be misrepresented, either by
 *    explicit claim or by omission.  Credit to the authors and Purdue
 *    University must appear in documentation and sources.
 *
 * 3. Altered versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 *
 * 4. This notice may not be removed or altered.
 */


#include "../machine.h"

#ifdef	USE_LIB_REGEX
/*
 * This file comes from GLIBC 2.2.  It is used when the UNIX dialect does not
 * have a POSIX-conformant regular expression function set.  In that case
 * USE_LIB_REGEX is defined.
 */

/* Extended regular expression matching and search library,
   version 0.12.
   (Implements POSIX draft P1003.2/D11.2, except for some of the
   internationalization features.)
   Copyright (C) 1993-1999, 2000 Free Software Foundation, Inc.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

/* AIX requires this to be the first thing in the file. */
#if defined _AIX && !defined REGEX_MALLOC
  #pragma alloca
#endif

#undef	_GNU_SOURCE
#define _GNU_SOURCE

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#ifndef PARAMS
# if defined __GNUC__ || (defined __STDC__ && __STDC__)
#  define PARAMS(args) args
# else
#  define PARAMS(args) ()
# endif  /* GCC.  */
#endif  /* Not PARAMS.  */

#if defined STDC_HEADERS && !defined emacs
# include <stddef.h>
#else
/* We need this for `regex.h', and perhaps for the Emacs include files.  */
# include <sys/types.h>
#endif

#define WIDE_CHAR_SUPPORT (HAVE_WCTYPE_H && HAVE_WCHAR_H && HAVE_BTOWC)

/* For platform which support the ISO C amendement 1 functionality we
   support user defined character classes.  */
#if defined _LIBC || WIDE_CHAR_SUPPORT
/* Solaris 2.5 has a bug: <wchar.h> must be included before <wctype.h>.  */
# include <wchar.h>
# include <wctype.h>
#endif

#ifdef _LIBC
/* We have to keep the namespace clean.  */
# define regfree(preg) __regfree (preg)
# define regexec(pr, st, nm, pm, ef) __regexec (pr, st, nm, pm, ef)
# define regcomp(preg, pattern, cflags) __regcomp (preg, pattern, cflags)
# define regerror(errcode, preg, errbuf, errbuf_size) \
	__regerror(errcode, preg, errbuf, errbuf_size)
# define re_set_registers(bu, re, nu, st, en) \
	__re_set_registers (bu, re, nu, st, en)
# define re_match_2(bufp, string1, size1, string2, size2, pos, regs, stop) \
	__re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
# define re_match(bufp, string, size, pos, regs) \
	__re_match (bufp, string, size, pos, regs)
# define re_search(bufp, string, size, startpos, range, regs) \
	__re_search (bufp, string, size, startpos, range, regs)
# define re_compile_pattern(pattern, length, bufp) \
	__re_compile_pattern (pattern, length, bufp)
# define re_set_syntax(syntax) __re_set_syntax (syntax)
# define re_search_2(bufp, st1, s1, st2, s2, startpos, range, regs, stop) \
	__re_search_2 (bufp, st1, s1, st2, s2, startpos, range, regs, stop)
# define re_compile_fastmap(bufp) __re_compile_fastmap (bufp)

# define btowc __btowc

/* We are also using some library internals.  */
# include <locale/localeinfo.h>
# include <locale/elem-hash.h>
# include <langinfo.h>
#endif

/* This is for other GNU distributions with internationalized messages.  */
#if HAVE_LIBINTL_H || defined _LIBC
# include <libintl.h>
# ifdef _LIBC
#  undef gettext
#  define gettext(msgid) __dcgettext ("libc", msgid, LC_MESSAGES)
# endif
#else
# define gettext(msgid) (msgid)
#endif

#ifndef gettext_noop
/* This define is so xgettext can find the internationalizable
   strings.  */
# define gettext_noop(String) String
#endif

/* The `emacs' switch turns on certain matching commands
   that make sense only in Emacs. */
#ifdef emacs

# include "lisp.h"
# include "buffer.h"
# include "syntax.h"

#else  /* not emacs */

/* If we are not linking with Emacs proper,
   we can't use the relocating allocator
   even if config.h says that we can.  */
# undef REL_ALLOC

# if defined STDC_HEADERS || defined _LIBC
#  include <stdlib.h>
# else
char *malloc ();
char *realloc ();
# endif

/* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
   If nothing else has been done, use the method below.  */
# ifdef INHIBIT_STRING_HEADER
#  if !(defined HAVE_BZERO && defined HAVE_BCOPY)
#   if !defined bzero && !defined bcopy
#    undef INHIBIT_STRING_HEADER
#   endif
#  endif
# endif

/* This is the normal way of making sure we have a bcopy and a bzero.
   This is used in most programs--a few other programs avoid this
   by defining INHIBIT_STRING_HEADER.  */
# ifndef INHIBIT_STRING_HEADER
#  if defined HAVE_STRING_H || defined STDC_HEADERS || defined _LIBC
#   include <string.h>
#   ifndef bzero
#    ifndef _LIBC
#     define bzero(s, n)	(memset (s, '\0', n), (s))
#    else
#     define bzero(s, n)	__bzero (s, n)
#    endif
#   endif
#  else
#   include <strings.h>
#   ifndef memcmp
#    define memcmp(s1, s2, n)	bcmp (s1, s2, n)
#   endif
#   ifndef memcpy
#    define memcpy(d, s, n)	(bcopy (s, d, n), (d))
#   endif
#  endif
# endif

/* Define the syntax stuff for \<, \>, etc.  */

/* This must be nonzero for the wordchar and notwordchar pattern
   commands in re_match_2.  */
# ifndef Sword
#  define Sword 1
# endif

# ifdef SWITCH_ENUM_BUG
#  define SWITCH_ENUM_CAST(x) ((int)(x))
# else
#  define SWITCH_ENUM_CAST(x) (x)
# endif

#endif /* not emacs */

#if defined _LIBC || HAVE_LIMITS_H
# include <limits.h>
#endif

#ifndef MB_LEN_MAX
# define MB_LEN_MAX 1
#endif

/* Get the interface, including the syntax bits.  */
/* Disabled by V. Abell on January 29, 2001: #include <regex.h> */
#include "../regex.h"

/* 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 ()
{
   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 */

/* 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 int re_match_2_internal PARAMS ((struct re_pattern_buffer *bufp,
					const char *string1, int size1,
					const char *string2, int size2,
					int pos,
					struct re_registers *regs,
					int stop));

/* These are the command codes that appear in compiled regular
   expressions.  Some opcodes are followed by argument bytes.  A
   command code can specify any interpretation whatsoever for its
   arguments.  Zero bytes may appear in the compiled regular expression.  */

typedef enum
{
  no_op = 0,

  /* Succeed right away--no more backtracking.  */
  succeed,

        /* Followed by one byte giving n, then by n literal bytes.  */
  exactn,

        /* Matches any (more or less) character.  */
  anychar,

        /* Matches any one char belonging to specified set.  First
           following byte is number of bitmap bytes.  Then come bytes
           for a bitmap saying which chars are in.  Bits in each byte
           are ordered low-bit-first.  A character is in the set if its
           bit is 1.  A character too large to have a bit in the map is
           automatically not in the set.  */
  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.  */
  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.  */
  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.  */
  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.  */
  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.  */
  succeed_n,

        /* Followed by two-byte relative address, and two-byte number n.
           Jump to the address N times, then fail.  */
  jump_n,

        /* Set the following two-byte relative address to the
           subsequent two-byte number.  The address *includes* the two
           bytes of number.  */
  set_number_at,

  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;

/* Common operations on the compiled pattern.  */

/* Store NUMBER in two contiguous bytes starting at DESTINATION.  */

#define STORE_NUMBER(destination, number)				\
  do {									\
    (destination)[0] = (number) & 0377;					\
    (destination)[1] = (number) >> 8;					\
  } while (0)

/* Same as STORE_NUMBER, except increment DESTINATION to
   the byte after where the number is stored.  Therefore, DESTINATION
   must be an lvalue.  */

#define STORE_NUMBER_AND_INCR(destination, number)			\
  do {									\
    STORE_NUMBER (destination, number);					\
    (destination) += 2;							\
  } while (0)

/* Put into DESTINATION a number stored in two contiguous bytes starting
   at SOURCE.  */

#define EXTRACT_NUMBER(destination, source)				\
  do {									\
    (destination) = *(source) & 0377;					\
    (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8;		\
  } while (0)

#ifdef DEBUG
static void extract_number _RE_ARGS ((int *dest, unsigned char *source));
static void
extract_number (dest, source)
    int *dest;
    unsigned char *source;
{
  int temp = SIGN_EXTEND_CHAR (*(source + 1));
  *dest = *source & 0377;
  *dest += temp << 8;
}

# ifndef EXTRACT_MACROS /* To debug the macros.  */
#  undef EXTRACT_NUMBER
#  define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
# endif /* not EXTRACT_MACROS */

#endif /* DEBUG */

/* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
   SOURCE must be an lvalue.  */

#define EXTRACT_NUMBER_AND_INCR(destination, source)			\
  do {									\
    EXTRACT_NUMBER (destination, source);				\
    (source) += 2; 							\
  } while (0)

#ifdef DEBUG
static void extract_number_and_incr _RE_ARGS ((int *destination,
					       unsigned char **source));
static void
extract_number_and_incr (destination, source)
    int *destination;
    unsigned char **source;
{
  extract_number (destination, *source);
  *source += 2;
}

# ifndef EXTRACT_MACROS
#  undef EXTRACT_NUMBER_AND_INCR
#  define EXTRACT_NUMBER_AND_INCR(dest, src) \
  extract_number_and_incr (&dest, &src)
# endif /* not EXTRACT_MACROS */

#endif /* DEBUG */

/* If DEBUG is defined, Regex prints many voluminous messages about what
   it is doing (if the variable `debug' is nonzero).  If linked with the
   main program in `iregex.c', you can enter patterns and strings
   interactively.  And if linked with the main program in `main.c' and
   the other test files, you can run the already-written tests.  */

#ifdef DEBUG

/* We use standard I/O for debugging.  */
# include <stdio.h>

/* It is useful to test things that ``must'' be true when debugging.  */
# include <assert.h>

static int debug;

# 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)
# define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) 				\
  if (debug) print_partial_compiled_pattern (s, e)
# define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)			\
  if (debug) print_double_string (w, s1, sz1, s2, sz2)


/* Print the fastmap in human-readable form.  */

void
print_fastmap (fastmap)
    char *fastmap;
{
  unsigned was_a_range = 0;
  unsigned i = 0;

  while (i < (1 << BYTEWIDTH))
    {
      if (fastmap[i++])
	{
	  was_a_range = 0;
          putchar (i - 1);
          while (i < (1 << BYTEWIDTH)  &&  fastmap[i])
            {
              was_a_range = 1;
              i++;
            }
	  if (was_a_range)
            {
              printf ("-");
              putchar (i - 1);
            }
        }
    }
  putchar ('\n');
}


/* Print a compiled pattern string in human-readable form, starting at
   the START pointer into it and ending just before the pointer END.  */

void
print_partial_compiled_pattern (start, end)
    unsigned char *start;
    unsigned char *end;
{
  int mcnt, mcnt2;
  unsigned char *p1;
  unsigned char *p = start;
  unsigned char *pend = end;

  if (start == NULL)
    {
      printf ("(null)\n");
      return;
    }

  /* Loop over pattern commands.  */
  while (p < pend)
    {
#ifdef _LIBC
      printf ("%t:\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 ('/');
	      putchar (*p++);
            }
          while (--mcnt);
          break;

	case start_memory:
          mcnt = *p++;
          printf ("/start_memory/%d/%d", mcnt, *p++);
          break;

	case stop_memory:
          mcnt = *p++;
	  printf ("/stop_memory/%d/%d", mcnt, *p++);
          break;

	case duplicate:
	  printf ("/duplicate/%d", *p++);
	  break;

	case anychar:
	  printf ("/anychar");
	  break;

	case charset:
        case charset_not:
          {
            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;
	  }
	  break;

	case begline:
	  printf ("/begline");
          break;

	case endline:
          printf ("/endline");
          break;

	case on_failure_jump:
          extract_number_and_incr (&mcnt, &p);
#ifdef _LIBC
  	  printf ("/on_failure_jump to %t", p + mcnt - start);
#else
  	  printf ("/on_failure_jump to %ld", (long int) (p + mcnt - start));
#endif
          break;

	case on_failure_keep_string_jump:
          extract_number_and_incr (&mcnt, &p);
#ifdef _LIBC
  	  printf ("/on_failure_keep_string_jump to %t", p + mcnt - start);
#else
  	  printf ("/on_failure_keep_string_jump to %ld",
		  (long int) (p + mcnt - start));
#endif
          break;

	case dummy_failure_jump:
          extract_number_and_incr (&mcnt, &p);
#ifdef _LIBC
  	  printf ("/dummy_failure_jump to %t", 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:
          extract_number_and_incr (&mcnt, &p);
#ifdef _LIBC
  	  printf ("/maybe_pop_jump to %t", p + mcnt - start);
#else
  	  printf ("/maybe_pop_jump to %ld", (long int) (p + mcnt - start));
#endif
	  break;

        case pop_failure_jump:
	  extract_number_and_incr (&mcnt, &p);
#ifdef _LIBC
  	  printf ("/pop_failure_jump to %t", p + mcnt - start);
#else
  	  printf ("/pop_failure_jump to %ld", (long int) (p + mcnt - start));
#endif
	  break;

        case jump_past_alt:
	  extract_number_and_incr (&mcnt, &p);
#ifdef _LIBC
  	  printf ("/jump_past_alt to %t", p + mcnt - start);
#else
  	  printf ("/jump_past_alt to %ld", (long int) (p + mcnt - start));
#endif
	  break;

        case jump:
	  extract_number_and_incr (&mcnt, &p);
#ifdef _LIBC
  	  printf ("/jump to %t", p + mcnt - start);
#else
  	  printf ("/jump to %ld", (long int) (p + mcnt - start));
#endif
	  break;

        case succeed_n:
          extract_number_and_incr (&mcnt, &p);
	  p1 = p + mcnt;
          extract_number_and_incr (&mcnt2, &p);
#ifdef _LIBC
	  printf ("/succeed_n to %t, %d times", p1 - start, mcnt2);
#else
	  printf ("/succeed_n to %ld, %d times",
		  (long int) (p1 - start), mcnt2);
#endif
          break;

        case jump_n:
          extract_number_and_incr (&mcnt, &p);
	  p1 = p + mcnt;
          extract_number_and_incr (&mcnt2, &p);
	  printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
          break;

        case set_number_at:
          extract_number_and_incr (&mcnt, &p);
	  p1 = p + mcnt;
          extract_number_and_incr (&mcnt2, &p);
#ifdef _LIBC
	  printf ("/set_number_at location %t 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");

# 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 ("?%d", *(p-1));
	}

      putchar ('\n');
    }

#ifdef _LIBC
  printf ("%t:\tend of pattern.\n", p - start);
#else
  printf ("%ld:\tend of pattern.\n", (long int) (p - start));
#endif
}


void
print_compiled_pattern (bufp)
    struct re_pattern_buffer *bufp;
{
  unsigned char *buffer = bufp->buffer;

  print_partial_compiled_pattern (buffer, buffer + bufp->used);
  printf ("%ld bytes used/%ld bytes allocated.\n",
	  bufp->used, bufp->allocated);

  if (bufp->fastmap_accurate && bufp->fastmap)
    {
      printf ("fastmap: ");
      print_fastmap (bufp->fastmap);
    }

#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
print_double_string (where, string1, size1, string2, size2)
    const char *where;
    const char *string1;
    const char *string2;
    int size1;
    int size2;
{
  int this_char;

  if (where == NULL)
    printf ("(null)");
  else
    {
      if (FIRST_STRING_P (where))
        {
          for (this_char = where - string1; this_char < size1; this_char++)
            putchar (string1[this_char]);

          where = string2;
        }

      for (this_char = where - string2; this_char < size2; this_char++)
        putchar (string2[this_char]);
    }
}

void
printchar (c)
     int c;
{
  putc (c, stderr);
}

#else /* not DEBUG */

# undef assert
# define assert(e)

# define DEBUG_STATEMENT(e)
# define DEBUG_PRINT1(x)
# define DEBUG_PRINT2(x1, x2)
# define DEBUG_PRINT3(x1, x2, x3)
# define DEBUG_PRINT4(x1, x2, x3, x4)
# define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
# define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)

#endif /* not DEBUG */

/* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
   also be assigned to arbitrarily: each pattern buffer stores its own
   syntax, so it can be changed between regex compilations.  */
/* This has no initializer because initialized variables in Emacs
   become read-only after dumping.  */
reg_syntax_t re_syntax_options;


/* Specify the precise syntax of regexps for compilation.  This provides
   for compatibility for various utilities which historically have
   different, incompatible syntaxes.

   The argument SYNTAX is a bit mask comprised of the various bits
   defined in regex.h.  We return the old syntax.  */

reg_syntax_t
re_set_syntax (syntax)
    reg_syntax_t syntax;
{
  reg_syntax_t ret = re_syntax_options;

  re_syntax_options = syntax;
#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[] =
  {
#define REG_NOERROR_IDX	0
    gettext_noop ("Success")	/* REG_NOERROR */
    "\0"
#define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success")
    gettext_noop ("No match")	/* REG_NOMATCH */
    "\0"
#define REG_BADPAT_IDX	(REG_NOMATCH_IDX + sizeof "No match")
    gettext_noop ("Invalid regular expression") /* REG_BADPAT */
    "\0"
#define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression")
    gettext_noop ("Invalid collation character") /* REG_ECOLLATE */
    "\0"
#define REG_ECTYPE_IDX	(REG_ECOLLATE_IDX + sizeof "Invalid collation character")
    gettext_noop ("Invalid character class name") /* REG_ECTYPE */
    "\0"
#define REG_EESCAPE_IDX	(REG_ECTYPE_IDX + sizeof "Invalid character class name")
    gettext_noop ("Trailing backslash") /* REG_EESCAPE */
    "\0"
#define REG_ESUBREG_IDX	(REG_EESCAPE_IDX + sizeof "Trailing backslash")
    gettext_noop ("Invalid back reference") /* REG_ESUBREG */
    "\0"
#define REG_EBRACK_IDX	(REG_ESUBREG_IDX + sizeof "Invalid back reference")
    gettext_noop ("Unmatched [ or [^")	/* REG_EBRACK */
    "\0"
#define REG_EPAREN_IDX	(REG_EBRACK_IDX + sizeof "Unmatched [ or [^")
    gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */
    "\0"
#define REG_EBRACE_IDX	(REG_EPAREN_IDX + sizeof "Unmatched ( or \\(")
    gettext_noop ("Unmatched \\{") /* REG_EBRACE */
    "\0"
#define REG_BADBR_IDX	(REG_EBRACE_IDX + sizeof "Unmatched \\{")
    gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */
    "\0"
#define REG_ERANGE_IDX	(REG_BADBR_IDX + sizeof "Invalid content of \\{\\}")
    gettext_noop ("Invalid range end")	/* REG_ERANGE */
    "\0"
#define REG_ESPACE_IDX	(REG_ERANGE_IDX + sizeof "Invalid range end")
    gettext_noop ("Memory exhausted") /* REG_ESPACE */
    "\0"
#define REG_BADRPT_IDX	(REG_ESPACE_IDX + sizeof "Memory exhausted")
    gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */
    "\0"
#define REG_EEND_IDX	(REG_BADRPT_IDX + sizeof "Invalid preceding regular expression")
    gettext_noop ("Premature end of regular expression") /* REG_EEND */
    "\0"
#define REG_ESIZE_IDX	(REG_EEND_IDX + sizeof "Premature end of regular expression")
    gettext_noop ("Regular expression too big") /* REG_ESIZE */
    "\0"
#define REG_ERPAREN_IDX	(REG_ESIZE_IDX + sizeof "Regular expression too big")
    gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
  };

static const size_t re_error_msgid_idx[] =
  {
    REG_NOERROR_IDX,
    REG_NOMATCH_IDX,
    REG_BADPAT_IDX,
    REG_ECOLLATE_IDX,
    REG_ECTYPE_IDX,
    REG_EESCAPE_IDX,
    REG_ESUBREG_IDX,
    REG_EBRACK_IDX,
    REG_EPAREN_IDX,
    REG_EBRACE_IDX,
    REG_BADBR_IDX,
    REG_ERANGE_IDX,
    REG_ESPACE_IDX,
    REG_BADRPT_IDX,
    REG_EEND_IDX,
    REG_ESIZE_IDX,
    REG_ERPAREN_IDX
  };

/* Avoiding alloca during matching, to placate r_alloc.  */

/* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
   searching and matching functions should not call alloca.  On some
   systems, alloca is implemented in terms of malloc, and if we're
   using the relocating allocator routines, then malloc could cause a
   relocation, which might (if the strings being searched are in the
   ralloc heap) shift the data out from underneath the regexp
   routines.

   Here's another reason to avoid allocation: Emacs
   processes input from X in a signal handler; processing X input may
   call malloc; if input arrives while a matching routine is calling
   malloc, then we're scrod.  But Emacs can't just block input while
   calling matching routines; then we don't notice interrupts when
   they come in.  So, Emacs blocks input around all regexp calls
   except the matching calls, which it leaves unprotected, in the
   faith that they will not malloc.  */

/* Normally, this is fine.  */
#define MATCH_MAY_ALLOCATE

/* When using GNU C, we are not REALLY using the C alloca, no matter
   what config.h may say.  So don't take precautions for it.  */
#ifdef __GNUC__
# undef C_ALLOCA
#endif

/* The match routines may not allocate if (1) they would do it with malloc
   and (2) it's not safe for them to use malloc.
   Note that if REL_ALLOC is defined, matching would not use malloc for the
   failure stack, but we would still use it for the register vectors;
   so REL_ALLOC should not affect this.  */
#if (defined C_ALLOCA || defined REGEX_MALLOC) && defined emacs
# undef MATCH_MAY_ALLOCATE
#endif


/* Failure stack declarations and macros; both re_compile_fastmap and
   re_match_2 use a failure stack.  These have to be macros because of
   REGEX_ALLOCATE_STACK.  */


/* 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

# 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

union fail_stack_elt
{
  unsigned char *pointer;
  long int integer;
};

typedef union fail_stack_elt fail_stack_elt_t;

typedef struct
{
  fail_stack_elt_t *stack;
  unsigned long int size;
  unsigned long int avail;		/* Offset of next open position.  */
} fail_stack_type;

#else /* not INT_IS_16BIT */

# 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

union fail_stack_elt
{
  unsigned char *pointer;
  int integer;
};

typedef union fail_stack_elt fail_stack_elt_t;

typedef struct
{
  fail_stack_elt_t *stack;
  unsigned size;
  unsigned avail;			/* Offset of next open position.  */
} fail_stack_type;

#endif /* INT_IS_16BIT */

#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)


/* Define macros to initialize and free the failure stack.
   Do `return -2' if the alloc fails.  */

#ifdef MATCH_MAY_ALLOCATE
# define INIT_FAIL_STACK()						\
  do {									\
    fail_stack.stack = (fail_stack_elt_t *)				\
      REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (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 = (fail_stack_elt_t *)				\
        REGEX_REALLOCATE_STACK ((fail_stack).stack, 			\
          (fail_stack).size * sizeof (fail_stack_elt_t),		\
          ((fail_stack).size << 1) * sizeof (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 = (unsigned char *) (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)

/* 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)


/* 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 unsigned char *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 *) string_temp;					\
									\
  DEBUG_PRINT2 ("  Popping string %p: `", str);				\
  DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2);	\
  DEBUG_PRINT1 ("'\n");							\
									\
  pat = (unsigned char *) 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 *) POP_FAILURE_POINTER ();	\
	DEBUG_PRINT2 ("      end: %p\n", regend[this_reg]);		\
									\
	regstart[this_reg] = (const char *) 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
{
  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;
} register_info_type;

#define REG_MATCH_NULL_STRING_P(R)  ((R).bits.match_null_string_p)
#define IS_ACTIVE(R)  ((R).bits.is_active)
#def…