/* Hierarchial argument parsing
   Copyright (C) 1995, 96, 97, 98, 99, 2000,2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Written by Miles Bader <miles@gnu.ai.mit.edu>.

   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.  */

#ifndef _GNU_SOURCE
# define _GNU_SOURCE	1
#endif

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

/* AIX requires this to be the first thing in the file.  */
#ifndef __GNUC__
# if HAVE_ALLOCA_H
#  include <alloca.h>
# else
#  ifdef _AIX
 #pragma alloca
#  else
#   ifndef alloca /* predefined by HP cc +Olibcalls */
char *alloca ();
#   endif
#  endif
# endif
#endif

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <assert.h>
#ifdef _WIN32
#include <malloc.h>
#endif

#ifndef _
/* This is for other GNU distributions with internationalized messages.
   When compiling libc, the _ macro is predefined.  */
# if defined HAVE_LIBINTL_H || defined _LIBC
#  include <libintl.h>
#  ifdef _LIBC
#   undef dgettext
#   define dgettext(domain, msgid) __dcgettext (domain, msgid, LC_MESSAGES)
#  endif
# else
#  define dgettext(domain, msgid) (msgid)
#  define gettext(msgid) (msgid)
# endif
#endif
#ifndef N_
# define N_(msgid) (msgid)
#endif

#if _LIBC - 0
#include <bits/libc-lock.h>
#else
#ifdef HAVE_CTHREADS_H
#include <cthreads.h>
#endif
#endif /* _LIBC */

#include "argp.h"
#include "argp-namefrob.h"


/* The meta-argument used to prevent any further arguments being interpreted
   as options.  */
#define QUOTE "--"

/* EZ alias for ARGP_ERR_UNKNOWN.  */
#define EBADKEY ARGP_ERR_UNKNOWN


/* Default options.  */

/* When argp is given the --HANG switch, _ARGP_HANG is set and argp will sleep
   for one second intervals, decrementing _ARGP_HANG until it's zero.  Thus
   you can force the program to continue by attaching a debugger and setting
   it to 0 yourself.  */
volatile int _argp_hang;

#define OPT_PROGNAME	-2
#define OPT_USAGE	-3
#define OPT_HANG	-4

static const struct argp_option argp_default_options[] =
{
  {"help",	  '?',    	0, 0,  N_("Give this help list"), -1},
  {"usage",	  OPT_USAGE,	0, 0,  N_("Give a short usage message"), 0 },
  {"program-name",OPT_PROGNAME,"NAME", OPTION_HIDDEN,
     N_("Set the program name"), 0},
  {"HANG",	  OPT_HANG,    "SECS", OPTION_ARG_OPTIONAL | OPTION_HIDDEN,
     N_("Hang for SECS seconds (default 3600)"), 0 },
  {0, 0, 0, 0, 0, 0}
};

static error_t
argp_default_parser (int key, char *arg, struct argp_state *state)
{
  switch (key)
    {
    case '?':
      __argp_state_help (state, state->out_stream, ARGP_HELP_STD_HELP);
      break;
    case OPT_USAGE:
      __argp_state_help (state, state->out_stream,
		       ARGP_HELP_USAGE | ARGP_HELP_EXIT_OK);
      break;

    case OPT_PROGNAME:		/* Set the program name.  */
#if HAVE_DECL_PROGRAM_INVOCATION_NAME
      program_invocation_name = arg;
#endif
      /* [Note that some systems only have PROGRAM_INVOCATION_SHORT_NAME (aka
	 __PROGNAME), in which case, PROGRAM_INVOCATION_NAME is just defined
	 to be that, so we have to be a bit careful here.]  */

      /* Update what we use for messages.  */

      state->name = __argp_basename(arg);
      
#if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME
      program_invocation_short_name = state->name;
#endif

      if ((state->flags & (ARGP_PARSE_ARGV0 | ARGP_NO_ERRS))
	  == ARGP_PARSE_ARGV0)
	/* Update what getopt uses too.  */
	state->argv[0] = arg;

      break;

    case OPT_HANG:
      _argp_hang = atoi (arg ? arg : "3600");
      fprintf(state->err_stream, "%s: pid = %ld\n",
	      state->name, (long) getpid());
      while (_argp_hang-- > 0)
	__sleep(1);
      break;

    default:
      return EBADKEY;
    }
  return 0;
}

static const struct argp argp_default_argp =
  {argp_default_options, &argp_default_parser, NULL, NULL, NULL, NULL, "libc"};


static const struct argp_option argp_version_options[] =
{
  {"version",	  'V',    	0, 0,  N_("Print program version"), -1},
  {0, 0, 0, 0, 0, 0 }
};

static error_t
argp_version_parser (int key, char *arg UNUSED, struct argp_state *state)
{
  switch (key)
    {
    case 'V':
      if (argp_program_version_hook)
	(*argp_program_version_hook) (state->out_stream, state);
      else if (argp_program_version)
	fprintf (state->out_stream, "%s\n", argp_program_version);
      else
	__argp_error (state, dgettext (state->root_argp->argp_domain,
				       "(PROGRAM ERROR) No version known!?"));
      if (! (state->flags & ARGP_NO_EXIT))
	exit (0);
      break;
    default:
      return EBADKEY;
    }
  return 0;
}

static const struct argp argp_version_argp =
  {argp_version_options, &argp_version_parser, NULL, NULL, NULL, NULL, "libc"};



/* The state of a `group' during parsing.  Each group corresponds to a
   particular argp structure from the tree of such descending from the top
   level argp passed to argp_parse.  */
struct group
{
  /* This group's parsing function.  */
  argp_parser_t parser;

  /* Which argp this group is from.  */
  const struct argp *argp;

  /* The number of non-option args sucessfully handled by this parser.  */
  unsigned args_processed;

  /* This group's parser's parent's group.  */
  struct group *parent;
  unsigned parent_index;	/* And the our position in the parent.   */

  /* These fields are swapped into and out of the state structure when
     calling this group's parser.  */
  void *input, **child_inputs;
  void *hook;
};

/* Call GROUP's parser with KEY and ARG, swapping any group-specific info
   from STATE before calling, and back into state afterwards.  If GROUP has
   no parser, EBADKEY is returned.  */
static error_t
group_parse (struct group *group, struct argp_state *state, int key, char *arg)
{
  if (group->parser)
    {
      error_t err;
      state->hook = group->hook;
      state->input = group->input;
      state->child_inputs = group->child_inputs;
      state->arg_num = group->args_processed;
      err = (*group->parser)(key, arg, state);
      group->hook = state->hook;
      return err;
    }
  else
    return EBADKEY;
}

struct parser
{
  const struct argp *argp;

  const char *posixly_correct;
  
  /* True if there are only no-option arguments left, which are just
     passed verbatim with ARGP_KEY_ARG. This is set if we encounter a
     quote, or the end of the proper options, but may be cleared again
     if the user moves the next argument pointer backwards. */
  int args_only;

  /* Describe how to deal with options that follow non-option ARGV-elements.

     If the caller did not specify anything, the default is
     REQUIRE_ORDER if the environment variable POSIXLY_CORRECT is
     defined, PERMUTE otherwise.

     REQUIRE_ORDER means don't recognize them as options; stop option
     processing when the first non-option is seen. This is what Unix
     does. This mode of operation is selected by either setting the
     environment variable POSIXLY_CORRECT, or using `+' as the first
     character of the list of option characters.

     PERMUTE is the default. We permute the contents of ARGV as we
     scan, so that eventually all the non-options are at the end. This
     allows options to be given in any order, even with programs that
     were not written to expect this.

     RETURN_IN_ORDER is an option available to programs that were
     written to expect options and other ARGV-elements in any order
     and that care about the ordering of the two. We describe each
     non-option ARGV-element as if it were the argument of an option
     with character code 1. Using `-' as the first character of the
     list of option characters selects this mode of operation.

  */
  enum { REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER } ordering;

  /* A segment of non-option arguments that have been skipped for
     later processing, after all options. `first_nonopt' is the index
     in ARGV of the first of them; `last_nonopt' is the index after
     the last of them.

     If quoted or args_only is non-zero, this segment should be empty. */

  /* FIXME: I'd prefer to use unsigned, but it's more consistent to
     use the same type as for state.next. */
  int first_nonopt;
  int last_nonopt;
  
  /* String of all recognized short options. Needed for ARGP_LONG_ONLY. */
  /* FIXME: Perhaps change to a pointer to a suitable bitmap instead? */
  char *short_opts;

  /* For parsing combined short options. */
  char *nextchar;
  
  /* States of the various parsing groups.  */
  struct group *groups;
  /* The end of the GROUPS array.  */
  struct group *egroup;
  /* An vector containing storage for the CHILD_INPUTS field in all groups.  */
  void **child_inputs;
  
  /* State block supplied to parsing routines.  */
  struct argp_state state;

  /* Memory used by this parser.  */
  void *storage;
};

/* Search for a group defining a short option. */
static const struct argp_option *
find_short_option(struct parser *parser, int key, struct group **p)
{
  struct group *group;
  
  assert(key >= 0);
  assert(isascii(key));

  for (group = parser->groups; group < parser->egroup; group++)
    {
      const struct argp_option *opts;

      for (opts = group->argp->options; !__option_is_end(opts); opts++)
	if (opts->key == key)
	  {
	    *p = group;
	    return opts;
	  }
    }
  return NULL;
}

enum match_result { MATCH_EXACT, MATCH_PARTIAL, MATCH_NO };

/* If defined, allow complete.el-like abbreviations of long options. */
#ifndef ARGP_COMPLETE
#define ARGP_COMPLETE 0
#endif

/* Matches an encountern long-option argument ARG against an option NAME.
 * ARG is terminated by NUL or '='. */
static enum match_result
match_option(const char *arg, const char *name)
{
  unsigned i, j;
  for (i = j = 0;; i++, j++)
    {
      switch(arg[i])
	{
	case '\0':
	case '=':
	  return name[j] ? MATCH_PARTIAL : MATCH_EXACT;
#if ARGP_COMPLETE
	case '-':
	  while (name[j] != '-')
	    if (!name[j++])
	      return MATCH_NO;
	  break;
#endif
	default:
	  if (arg[i] != name[j])
	    return MATCH_NO;
	}
    }
}

static const struct argp_option *
find_long_option(struct parser *parser,
		 const char *arg,
		 struct group **p)
{
  struct group *group;

  /* Partial match found so far. */
  struct group *matched_group = NULL;
  const struct argp_option *matched_option = NULL;

  /* Number of partial matches. */
  int num_partial = 0;

  for (group = parser->groups; group < parser->egroup; group++)
    {
      const struct argp_option *opts;

      for (opts = group->argp->options; !__option_is_end(opts); opts++)
	{
	  if (!opts->name)
	    continue;
	  switch (match_option(arg, opts->name))
	    {
	    case MATCH_NO:
	      break;
	    case MATCH_PARTIAL:
	      num_partial++;

	      matched_group = group;
	      matched_option = opts;

	      break;
	    case MATCH_EXACT:
	      /* Exact match. */
	      *p = group;
	      return opts;
	    }
	}
    }
  if (num_partial == 1)
    {
      *p = matched_group;
      return matched_option;
    }

  return NULL;
}


/* The next usable entries in the various parser tables being filled in by
   convert_options.  */
struct parser_convert_state
{
  struct parser *parser;
  char *short_end;
  void **child_inputs_end;
};

/* Initialize GROUP from ARGP. If CVT->SHORT_END is non-NULL, short
   options are recorded in the short options string. Returns the next
   unused group entry. CVT holds state used during the conversion. */
static struct group *
convert_options (const struct argp *argp,
		 struct group *parent, unsigned parent_index,
		 struct group *group, struct parser_convert_state *cvt)
{
  const struct argp_option *opt = argp->options;
  const struct argp_child *children = argp->children;

  if (opt || argp->parser)
    {
      /* This parser needs a group. */
      if (cvt->short_end)
	{
	  /* Record any short options. */
	  for ( ; !__option_is_end (opt); opt++)
	    if (__option_is_short(opt))
	      *cvt->short_end++ = opt->key;
	}
      
      group->parser = argp->parser;
      group->argp = argp;
      group->args_processed = 0;
      group->parent = parent;
      group->parent_index = parent_index;
      group->input = 0;
      group->hook = 0;
      group->child_inputs = 0;
      
      if (children)
	/* Assign GROUP's CHILD_INPUTS field some space from
	   CVT->child_inputs_end.*/
	{
	  unsigned num_children = 0;
	  while (children[num_children].argp)
	    num_children++;
	  group->child_inputs = cvt->child_inputs_end;
	  cvt->child_inputs_end += num_children;
	}
      parent = group++;
    }
  else
    parent = 0;

  if (children)
    {
      unsigned index = 0;
      while (children->argp)
	group =
	  convert_options (children++->argp, parent, index++, group, cvt);
    }

  return group;
}
/* Allocate and initialize the group structures, so that they are
   ordered as if by traversing the corresponding argp parser tree in
   pre-order. Also build the list of short options, if that is needed. */
static void
parser_convert (struct parser *parser, const struct argp *argp)
{
  struct parser_convert_state cvt;

  cvt.parser = parser;
  cvt.short_end = parser->short_opts;
  cvt.child_inputs_end = parser->child_inputs;

  parser->argp = argp;

  if (argp)
    parser->egroup = convert_options (argp, 0, 0, parser->groups, &cvt);
  else
    parser->egroup = parser->groups; /* No parsers at all! */

  if (parser->short_opts)
    *cvt.short_end ='\0';
}

/* Lengths of various parser fields which we will allocated.  */
struct parser_sizes
{
  /* Needed only ARGP_LONG_ONLY */
  size_t short_len;		/* Number of short options.  */

  size_t num_groups;		/* Group structures we allocate.  */
  size_t num_child_inputs;	/* Child input slots.  */
};

/* For ARGP, increments the NUM_GROUPS field in SZS by the total
   number of argp structures descended from it, and the SHORT_LEN by
   the total number of short options. */
static void
calc_sizes (const struct argp *argp,  struct parser_sizes *szs)
{
  const struct argp_child *child = argp->children;
  const struct argp_option *opt = argp->options;

  if (opt || argp->parser)
    {
      /* This parser needs a group. */
      szs->num_groups++;
      if (opt)
	{
	  while (__option_is_short (opt++))
	    szs->short_len++;
	}
    }

  if (child)
    while (child->argp)
      {
	calc_sizes ((child++)->argp, szs);
	szs->num_child_inputs++;
      }
}

/* Initializes PARSER to parse ARGP in a manner described by FLAGS.  */
static error_t
parser_init (struct parser *parser, const struct argp *argp,
	     int argc, char **argv, int flags, void *input)
{
  error_t err = 0;
  struct group *group;
  struct parser_sizes szs;

  parser->posixly_correct = getenv ("POSIXLY_CORRECT");

  if (flags & ARGP_IN_ORDER)
    parser->ordering = RETURN_IN_ORDER;
  else if (flags & ARGP_NO_ARGS)
    parser->ordering = REQUIRE_ORDER;
  else if (parser->posixly_correct)
    parser->ordering = REQUIRE_ORDER;
  else
    parser->ordering = PERMUTE;
  
  szs.short_len = 0;
  szs.num_groups = 0;
  szs.num_child_inputs = 0;

  if (argp)
    calc_sizes (argp, &szs);

  if (!(flags & ARGP_LONG_ONLY))
    /* We have no use for the short option array. */
    szs.short_len = 0;
  
  /* Lengths of the various bits of storage used by PARSER.  */
#define GLEN (szs.num_groups + 1) * sizeof (struct group)
#define CLEN (szs.num_child_inputs * sizeof (void *))
#define SLEN (szs.short_len + 1)
#define STORAGE(offset) ((void *) (((char *) parser->storage) + (offset)))

  parser->storage = malloc (GLEN + CLEN + SLEN);
  if (! parser->storage)
    return ENOMEM;

  parser->groups = parser->storage;

  parser->child_inputs = STORAGE(GLEN);
  memset (parser->child_inputs, 0, szs.num_child_inputs * sizeof (void *));

  if (flags & ARGP_LONG_ONLY)
    parser->short_opts = STORAGE(GLEN + CLEN);
  else
    parser->short_opts = NULL;

  parser_convert (parser, argp);

  memset (&parser->state, 0, sizeof (struct argp_state));
  
  parser->state.root_argp = parser->argp;
  parser->state.argc = argc;
  parser->state.argv = argv;
  parser->state.flags = flags;
  parser->state.err_stream = stderr;
  parser->state.out_stream = stdout;
  parser->state.pstate = parser;

  parser->args_only = 0;
  parser->nextchar = NULL;
  parser->first_nonopt = parser->last_nonopt = 0;
    
  /* Call each parser for the first time, giving it a chance to propagate
     values to child parsers.  */
  if (parser->groups < parser->egroup)
    parser->groups->input = input;
  for (group = parser->groups;
       group < parser->egroup && (!err || err == EBADKEY);
       group++)
    {
      if (group->parent)
	/* If a child parser, get the initial input value from the parent. */
	group->input = group->parent->child_inputs[group->parent_index];

      if (!group->parser
	  && group->argp->children && group->argp->children->argp)
	/* For the special case where no parsing function is supplied for an
	   argp, propagate its input to its first child, if any (this just
	   makes very simple wrapper argps more convenient).  */
	group->child_inputs[0] = group->input;

      err = group_parse (group, &parser->state, ARGP_KEY_INIT, 0);
    }
  if (err == EBADKEY)
    err = 0;			/* Some parser didn't understand.  */

  if (err)
    return err;

  if (argv[0] && !(parser->state.flags & ARGP_PARSE_ARGV0))
    /* There's an argv[0]; use it for messages.  */
    {
      parser->state.name = __argp_basename(argv[0]);

      /* Don't parse it as an argument. */
      parser->state.next = 1;
    }
  else
    parser->state.name = __argp_short_program_name(NULL);
  
  return 0;
}

/* Free any storage consumed by PARSER (but not PARSER itself).  */
static error_t
parser_finalize (struct parser *parser,
		 error_t err, int arg_ebadkey, int *end_index)
{
  struct group *group;

  if (err == EBADKEY && arg_ebadkey)
    /* Suppress errors generated by unparsed arguments.  */
    err = 0;

  if (! err)
    {
      if (parser->state.next == parser->state.argc)
	/* We successfully parsed all arguments!  Call all the parsers again,
	   just a few more times... */
	{
	  for (group = parser->groups;
	       group < parser->egroup && (!err || err==EBADKEY);
	       group++)
	    if (group->args_processed == 0)
	      err = group_parse (group, &parser->state, ARGP_KEY_NO_ARGS, 0);
	  for (group = parser->egroup - 1;
	       group >= parser->groups && (!err || err==EBADKEY);
	       group--)
	    err = group_parse (group, &parser->state, ARGP_KEY_END, 0);

	  if (err == EBADKEY)
	    err = 0;		/* Some parser didn't understand.  */

	  /* Tell the user that all arguments are parsed.  */
	  if (end_index)
	    *end_index = parser->state.next;
	}
      else if (end_index)
	/* Return any remaining arguments to the user.  */
	*end_index = parser->state.next;
      else
	/* No way to return the remaining arguments, they must be bogus. */
	{
	  if (!(parser->state.flags & ARGP_NO_ERRS)
	      && parser->state.err_stream)
	    fprintf (parser->state.err_stream,
		     dgettext (parser->argp->argp_domain,
			       "%s: Too many arguments\n"),
		     parser->state.name);
	  err = EBADKEY;
	}
    }

  /* Okay, we're all done, with either an error or success; call the parsers
     to indicate which one.  */

  if (err)
    {
      /* Maybe print an error message.  */
      if (err == EBADKEY)
	/* An appropriate message describing what the error was should have
	   been printed earlier.  */
	__argp_state_help (&parser->state, parser->state.err_stream,
			   ARGP_HELP_STD_ERR);

      /* Since we didn't exit, give each parser an error indication.  */
      for (group = parser->groups; group < parser->egroup; group++)
	group_parse (group, &parser->state, ARGP_KEY_ERROR, 0);
    }
  else
    /* Notify parsers of success, and propagate back values from parsers.  */
    {
      /* We pass over the groups in reverse order so that child groups are
	 given a chance to do there processing before passing back a value to
	 the parent.  */
      for (group = parser->egroup - 1
	   ; group >= parser->groups && (!err || err == EBADKEY)
	   ; group--)
	err = group_parse (group, &parser->state, ARGP_KEY_SUCCESS, 0);
      if (err == EBADKEY)
	err = 0;		/* Some parser didn't understand.  */
    }

  /* Call parsers once more, to do any final cleanup.  Errors are ignored.  */
  for (group = parser->egroup - 1; group >= parser->groups; group--)
    group_parse (group, &parser->state, ARGP_KEY_FINI, 0);

  if (err == EBADKEY)
    err = EINVAL;

  free (parser->storage);

  return err;
}

/* Call the user parsers to parse the non-option argument VAL, at the
   current position, returning any error. The state NEXT pointer
   should point to the argument; this function will adjust it
   correctly to reflect however many args actually end up being
   consumed. */
static error_t
parser_parse_arg (struct parser *parser, char *val)
{
  /* Save the starting value of NEXT */
  int index = parser->state.next;
  error_t err = EBADKEY;
  struct group *group;
  int key = 0;			/* Which of ARGP_KEY_ARG[S] we used.  */

  /* Try to parse the argument in each parser.  */
  for (group = parser->groups
       ; group < parser->egroup && err == EBADKEY
       ; group++)
    {
      parser->state.next++;	/* For ARGP_KEY_ARG, consume the arg.  */
      key = ARGP_KEY_ARG;
      err = group_parse (group, &parser->state, key, val);

      if (err == EBADKEY)
	/* This parser doesn't like ARGP_KEY_ARG; try ARGP_KEY_ARGS instead. */
	{
	  parser->state.next--;	/* For ARGP_KEY_ARGS, put back the arg.  */
	  key = ARGP_KEY_ARGS;
	  err = group_parse (group, &parser->state, key, 0);
	}
    }

  if (! err)
    {
      if (key == ARGP_KEY_ARGS)
	/* The default for ARGP_KEY_ARGS is to assume that if NEXT isn't
	   changed by the user, *all* arguments should be considered
	   consumed.  */
	parser->state.next = parser->state.argc;

      if (parser->state.next > index)
	/* Remember that we successfully processed a non-option
	   argument -- but only if the user hasn't gotten tricky and set
	   the clock back.  */
	(--group)->args_processed += (parser->state.next - index);
      else
	/* The user wants to reparse some args, so try looking for options again.  */
	parser->args_only = 0;
    }

  return err;
}

/* Exchange two adjacent subsequences of ARGV.
   One subsequence is elements [first_nonopt,last_nonopt)
   which contains all the non-options that have been skipped so far.
   The other is elements [last_nonopt,next), which contains all
   the options processed since those non-options were skipped.

   `first_nonopt' and `last_nonopt' are relocated so that they describe
   the new indices of the non-options in ARGV after they are moved.  */

static void
exchange (struct parser *parser)
{
  int bottom = parser->first_nonopt;
  int middle = parser->last_nonopt;
  int top = parser->state.next;
  char **argv = parser->state.argv;
  
  char *tem;

  /* Exchange the shorter segment with the far end of the longer segment.
     That puts the shorter segment into the right place.
     It leaves the longer segment in the right place overall,
     but it consists of two parts that need to be swapped next.  */

  while (top > middle && middle > bottom)
    {
      if (top - middle > middle - bottom)
	{
	  /* Bottom segment is the short one.  */
	  int len = middle - bottom;
	  register int i;

	  /* Swap it with the top part of the top segment.  */
	  for (i = 0; i < len; i++)
	    {
	      tem = argv[bottom + i];
	      argv[bottom + i] = argv[top - (middle - bottom) + i];
	      argv[top - (middle - bottom) + i] = tem;
	    }
	  /* Exclude the moved bottom segment from further swapping.  */
	  top -= len;
	}
      else
	{
	  /* Top segment is the short one.  */
	  int len = top - middle;
	  register int i;

	  /* Swap it with the bottom part of the bottom segment.  */
	  for (i = 0; i < len; i++)
	    {
	      tem = argv[bottom + i];
	      argv[bottom + i] = argv[middle + i];
	      argv[middle + i] = tem;
	    }
	  /* Exclude the moved top segment from further swapping.  */
	  bottom += len;
	}
    }

  /* Update records for the slots the non-options now occupy.  */

  parser->first_nonopt += (parser->state.next - parser->last_nonopt);
  parser->last_nonopt = parser->state.next;
}



enum arg_type { ARG_ARG, ARG_SHORT_OPTION,
		ARG_LONG_OPTION, ARG_LONG_ONLY_OPTION,
		ARG_QUOTE };

static enum arg_type
classify_arg(struct parser *parser, char *arg, char **opt)
{
  if (arg[0] == '-')
    /* Looks like an option... */
    switch (arg[1])
      {
      case '\0':
	/* "-" is not an option. */
	return ARG_ARG;
      case '-':
	/* Long option, or quote. */
	if (!arg[2])
	  return ARG_QUOTE;
	  
	/* A long option. */
	if (opt)
	  *opt = arg + 2;
	return ARG_LONG_OPTION;

      default:
	/* Short option. But if ARGP_LONG_ONLY, it can also be a long option. */

	if (opt)
	  *opt = arg + 1;

	if (parser->state.flags & ARGP_LONG_ONLY)
	  {
	    /* Rules from getopt.c:

	       If long_only and the ARGV-element has the form "-f",
	       where f is a valid short option, don't consider it an
	       abbreviated form of a long option that starts with f.
	       Otherwise there would be no way to give the -f short
	       option.

	       On the other hand, if there's a long option "fubar" and
	       the ARGV-element is "-fu", do consider that an
	       abbreviation of the long option, just like "--fu", and
	       not "-f" with arg "u".

	       This distinction seems to be the most useful approach. */

	    assert(parser->short_opts);
	    
	    if (arg[2] || !strchr(parser->short_opts, arg[1]))
	      return ARG_LONG_ONLY_OPTION;
	  }

	return ARG_SHORT_OPTION;
      }
  
  else
    return ARG_ARG;
}

/* Parse the next argument in PARSER (as indicated by PARSER->state.next).
   Any error from the parsers is returned, and *ARGP_EBADKEY indicates
   whether a value of EBADKEY is due to an unrecognized argument (which is
   generally not fatal).  */
static error_t
parser_parse_next (struct parser *parser, int *arg_ebadkey)
{
  if (parser->state.quoted && parser->state.next < parser->state.quoted)
    /* The next argument pointer has been moved to before the quoted
       region, so pretend we never saw the quoting `--', and start
       looking for options again. If the `--' is still there we'll just
       process it one more time. */
    parser->state.quoted = parser->args_only = 0;

  /* Give FIRST_NONOPT & LAST_NONOPT rational values if NEXT has been
     moved back by the user (who may also have changed the arguments).  */
  if (parser->last_nonopt > parser->state.next)
    parser->last_nonopt = parser->state.next;
  if (parser->first_nonopt > parser->state.next)
    parser->first_nonopt = parser->state.next;

  if (parser->nextchar)
    /* Deal with short options. */
    {
      struct group *group;
      char c;
      const struct argp_option *option;
      char *value = NULL;;

      assert(!parser->args_only);

      c = *parser->nextchar++;
      
      option = find_short_option(parser, c, &group);
      if (!option)
	{
	  if (parser->posixly_correct)
	    /* 1003.2 specifies the format of this message.  */
	    fprintf (parser->state.err_stream,
		     dgettext(parser->state.root_argp->argp_domain,
			      "%s: illegal option -- %c\n"),
		     parser->state.name, c);
	  else
	    fprintf (parser->state.err_stream,
		     dgettext(parser->state.root_argp->argp_domain,
			      "%s: invalid option -- %c\n"),
		     parser->state.name, c);

	  *arg_ebadkey = 0;
	  return EBADKEY;
	}

      if (!*parser->nextchar)
	parser->nextchar = NULL;

      if (option->arg)
	{
	  value = parser->nextchar;
	  parser->nextchar = NULL;
	      
	  if (!value
	      && !(option->flags & OPTION_ARG_OPTIONAL))
	    /* We need an mandatory argument. */
	    {
	      if (parser->state.next == parser->state.argc)
		/* Missing argument */
		{
		  /* 1003.2 specifies the format of this message.  */
		  fprintf (parser->state.err_stream,
			   dgettext(parser->state.root_argp->argp_domain,
				    "%s: option requires an argument -- %c\n"),
			   parser->state.name, c);

		  *arg_ebadkey = 0;
		  return EBADKEY;
		}
	      value = parser->state.argv[parser->state.next++];
	    }
	}
      return group_parse(group, &parser->state,
			 option->key, value);
    }
  else
    /* Advance to the next ARGV-element.  */
    {
      if (parser->args_only)
	{
	  *arg_ebadkey = 1;
	  if (parser->state.next >= parser->state.argc)
	    /* We're done. */
	    return EBADKEY;
	  else
	    return parser_parse_arg(parser,
				    parser->state.argv[parser->state.next]);
	}
      
      if (parser->state.next >= parser->state.argc)
	/* Almost done. If there are non-options that we skipped
	   previously, we should process them now. */
	{
	  *arg_ebadkey = 1;
	  if (parser->first_nonopt != parser->last_nonopt)
	    {
	      exchange(parser);
	      
	      /* Start processing the arguments we skipped previously. */
	      parser->state.next = parser->first_nonopt;
	      
	      parser->first_nonopt = parser->last_nonopt = 0;

	      parser->args_only = 1;
	      return 0;
	    }
	  else
	    /* Indicate that we're really done. */
	    return EBADKEY;
	}
      else
	/* Look for options. */
	{
	  char *arg = parser->state.argv[parser->state.next];

	  char *optstart;
	  enum arg_type token = classify_arg(parser, arg, &optstart);
	  
	  switch (token)
	    {
	    case ARG_ARG:
	      switch (parser->ordering)
		{
		case PERMUTE:
		  if (parser->first_nonopt == parser->last_nonopt)
		    /* Skipped sequence is empty; start a new one. */
		    parser->first_nonopt = parser->last_nonopt = parser->state.next;

		  else if (parser->last_nonopt != parser->state.next)
		    /* We have a non-empty skipped sequence, and
		       we're not at the end-point, so move it. */
		    exchange(parser);

		  assert(parser->last_nonopt == parser->state.next);
		  
		  /* Skip this argument for now. */
		  parser->state.next++;
		  parser->last_nonopt = parser->state.next; 
		  
		  return 0;

		case REQUIRE_ORDER:
		  /* Implicit quote before the first argument. */
		   parser->args_only = 1;
		   return 0;
		   
		case RETURN_IN_ORDER:
		  *arg_ebadkey = 1;
		  return parser_parse_arg(parser, arg);

		default:
		  abort();
		}
	    case ARG_QUOTE:
	      /* Skip it, then exchange with any previous non-options. */
	      parser->state.next++;
	      assert (parser->last_nonopt != parser->state.next);

	      if (parser->first_nonopt != parser->last_nonopt)
		{
		  exchange(parser);
		  
		  /* Start processing the skipped and the quoted
		     arguments. */

		  parser->state.quoted = parser->state.next = parser->first_nonopt;

		  /* Also empty the skipped-list, to avoid confusion
		     if the user resets the next pointer. */
		  parser->first_nonopt = parser->last_nonopt = 0;
		}
	      else
		parser->state.quoted = parser->state.next;

	      parser->args_only = 1;	      
	      return 0;

	    case ARG_LONG_ONLY_OPTION:
	    case ARG_LONG_OPTION:
	      {
		struct group *group;
		const struct argp_option *option;
		char *value;

		parser->state.next++;
		option = find_long_option(parser, optstart, &group);
		
		if (!option)
		  {
		    /* NOTE: This includes any "=something" in the output. */
		    fprintf (parser->state.err_stream,
			     dgettext(parser->state.root_argp->argp_domain,
				      "%s: unrecognized option `%s'\n"),
			     parser->state.name, arg);
		    *arg_ebadkey = 0;
		    return EBADKEY;
		  }

		value = strchr(optstart, '=');
		if (value)
		  value++;
		
		if (value && !option->arg)
		  /* Unexpected argument. */
		  {
		    if (token == ARG_LONG_OPTION)
		      /* --option */
		      fprintf (parser->state.err_stream,
			       dgettext(parser->state.root_argp->argp_domain,
					"%s: option `--%s' doesn't allow an argument\n"),
			       parser->state.name, option->name);
		    else
		      /* +option or -option */
		      fprintf (parser->state.err_stream,
			       dgettext(parser->state.root_argp->argp_domain,
					"%s: option `%c%s' doesn't allow an argument\n"),
			       parser->state.name, arg[0], option->name);

		    *arg_ebadkey = 0;
		    return EBADKEY;
		  }
		
		if (option->arg && !value
		    && !(option->flags & OPTION_ARG_OPTIONAL))
		  /* We need an mandatory argument. */
		  {
		    if (parser->state.next == parser->state.argc)
		      /* Missing argument */
		      {
			if (token == ARG_LONG_OPTION)
			  /* --option */
			  fprintf (parser->state.err_stream,
				   dgettext(parser->state.root_argp->argp_domain,
					    "%s: option `--%s' requires an argument\n"),
				 parser->state.name, option->name);
			else
			  /* +option or -option */
			  fprintf (parser->state.err_stream,
				   dgettext(parser->state.root_argp->argp_domain,
					    "%s: option `%c%s' requires an argument\n"),
				   parser->state.name, arg[0], option->name);

			*arg_ebadkey = 0;
			return EBADKEY;
		      }

		    value = parser->state.argv[parser->state.next++];
		  }
		*arg_ebadkey = 0;
		return group_parse(group, &parser->state,
				   option->key, value);
	      }
	    case ARG_SHORT_OPTION:
	      parser->state.next++;
	      parser->nextchar = optstart;
	      return 0;

	    default:
	      abort();
	    }
	}
    }
}

/* Parse the options strings in ARGC & ARGV according to the argp in ARGP.
   FLAGS is one of the ARGP_ flags above.  If END_INDEX is non-NULL, the
   index in ARGV of the first unparsed option is returned in it.  If an
   unknown option is present, EINVAL is returned; if some parser routine
   returned a non-zero value, it is returned; otherwise 0 is returned.  */
error_t
__argp_parse (const struct argp *argp, int argc, char **argv, unsigned flags,
	      int *end_index, void *input)
{
  error_t err;
  struct parser parser;

  /* If true, then err == EBADKEY is a result of a non-option argument failing
     to be parsed (which in some cases isn't actually an error).  */
  int arg_ebadkey = 0;

  if (! (flags & ARGP_NO_HELP))
    /* Add our own options.  */
    {
      struct argp_child *child = alloca (4 * sizeof (struct argp_child));
      struct argp *top_argp = alloca (sizeof (struct argp));

      /* TOP_ARGP has no options, it just serves to group the user & default
	 argps.  */
      memset (top_argp, 0, sizeof (*top_argp));
      top_argp->children = child;

      memset (child, 0, 4 * sizeof (struct argp_child));

      if (argp)
	(child++)->argp = argp;
      (child++)->argp = &argp_default_argp;
      if (argp_program_version || argp_program_version_hook)
	(child++)->argp = &argp_version_argp;
      child->argp = 0;

      argp = top_argp;
    }

  /* Construct a parser for these arguments.  */
  err = parser_init (&parser, argp, argc, argv, flags, input);

  if (! err)
    /* Parse! */
    {
      while (! err)
	err = parser_parse_next (&parser, &arg_ebadkey);
      err = parser_finalize (&parser, err, arg_ebadkey, end_index);
    }

  return err;
}
#ifdef weak_alias
weak_alias (__argp_parse, argp_parse)
#endif

/* Return the input field for ARGP in the parser corresponding to STATE; used
   by the help routines.  */
void *
__argp_input (const struct argp *argp, const struct argp_state *state)
{
  if (state)
    {
      struct group *group;
      struct parser *parser = state->pstate;

      for (group = parser->groups; group < parser->egroup; group++)
	if (group->argp == argp)
	  return group->input;
    }

  return 0;
}
#ifdef weak_alias
weak_alias (__argp_input, _argp_input)
#endif

/* Defined here, in case a user is not inlining the definitions in
 * argp.h */
void
__argp_usage (__const struct argp_state *__state)
{
  __argp_state_help (__state, stderr, ARGP_HELP_STD_USAGE);
}

int
__option_is_short (__const struct argp_option *__opt)
{
  if (__opt->flags & OPTION_DOC)
    return 0;
  else
    {
      int __key = __opt->key;
      /* FIXME: whether or not a particular key implies a short option
       * ought not to be locale dependent. */
      return __key > 0 && isprint (__key);
    }
}

int
__option_is_end (__const struct argp_option *__opt)
{
  return !__opt->key && !__opt->name && !__opt->doc && !__opt->group;
}
