argp-parse.c

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/* Hierarchial argument parsing, layered over getopt
   Copyright (C) 1995-2000, 2002, 2003, 2004 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Written by Miles Bader <[e-mail]>.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

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

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

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

#include <alloca.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <getopt.h>
#include <getopt_int.h>

#ifdef _LIBC
# include <libintl.h>
# undef dgettext
# define dgettext(domain, msgid) \
   INTUSE(__dcgettext) (domain, msgid, LC_MESSAGES)
#else
# include "gettext.h"
#endif
#define N_(msgid) msgid

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

#define alignof(type) offsetof (struct { char c; type x; }, x)
#define alignto(n, d) ((((n) + (d) - 1) / (d)) * (d))

/* Getopt return values.  */
#define KEY_END (-1)		/* The end of the options.  */
#define KEY_ARG 1		/* A non-option argument.  */
#define KEY_ERR '?'		/* An error parsing the options.  */

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

/* The number of bits we steal in a long-option value for our own use.  */
#define GROUP_BITS CHAR_BIT

/* The number of bits available for the user value.  */
#define USER_BITS ((sizeof ((struct option *)0)->val * CHAR_BIT) - GROUP_BITS)
#define USER_MASK ((1 << USER_BITS) - 1)

/* 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.  */
static 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,N_("NAME"), OPTION_HIDDEN, N_("set the program name"), 0},
  {"HANG",	  OPT_HANG,    N_("SECS"), OPTION_ARG_OPTIONAL | OPTION_HIDDEN,
     N_("hang for SECS seconds (default 3600)"), 0},
  {NULL, 0, 0, 0, NULL, 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 defined _LIBC || 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_base_name (arg);

#if defined _LIBC || 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");
      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},
  {NULL, 0, 0, 0, NULL, 0}
};

static error_t
argp_version_parser (int key, char *arg, 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"};

/* Returns the offset into the getopt long options array LONG_OPTIONS of a
   long option with called NAME, or -1 if none is found.  Passing NULL as
   NAME will return the number of options.  */
static int
find_long_option (struct option *long_options, const char *name)
{
  struct option *l = long_options;
  while (l->name != NULL)
    if (name != NULL && strcmp (l->name, name) == 0)
      return l - long_options;
    else
      l++;
  if (name == NULL)
    return l - long_options;
  else
    return -1;
}


/* 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;

  /* Points to the point in SHORT_OPTS corresponding to the end of the short
     options for this group.  We use it to determine from which group a
     particular short options is from.  */
  char *short_end;

  /* 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;

  /* SHORT_OPTS is the getopt short options string for the union of all the
     groups of options.  */
  char *short_opts;
  /* LONG_OPTS is the array of getop long option structures for the union of
     all the groups of options.  */
  struct option *long_opts;
  /* OPT_DATA is the getopt data used for the re-entrant getopt.  */
  struct _getopt_data opt_data;

  /* 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;

  /* True if we think using getopt is still useful; if false, then
     remaining arguments are just passed verbatim with ARGP_KEY_ARG.  This is
     cleared whenever getopt returns KEY_END, but may be set again if the user
     moves the next argument pointer backwards.  */
  int try_getopt;

  /* State block supplied to parsing routines.  */
  struct argp_state state;

  /* Memory used by this parser.  */
  void *storage;
};

/* 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;
  struct option *long_end;
  void **child_inputs_end;
};

/* Converts all options in ARGP (which is put in GROUP) and ancestors
   into getopt options stored in SHORT_OPTS and LONG_OPTS; SHORT_END and
   CVT->LONG_END are the points at which new options are added.  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)
{
  /* REAL is the most recent non-alias value of OPT.  */
  const struct argp_option *real = argp->options;
  const struct argp_child *children = argp->children;

  if (real || argp->parser)
    {
      const struct argp_option *opt;

      if (real)
	for (opt = real; !__option_is_end (opt); opt++)
	  {
	    if (! (opt->flags & OPTION_ALIAS))
	      /* OPT isn't an alias, so we can use values from it.  */
	      real = opt;

	    if (! (real->flags & OPTION_DOC))
	      /* A real option (not just documentation).  */
	      {
		if (__option_is_short (opt))
		  /* OPT can be used as a short option.  */
		  {
		    *cvt->short_end++ = opt->key;
		    if (real->arg)
		      {
			*cvt->short_end++ = ':';
			if (real->flags & OPTION_ARG_OPTIONAL)
			  *cvt->short_end++ = ':';
		      }
		    *cvt->short_end = '\0'; /* keep 0 terminated */
		  }

		if (opt->name
		    && find_long_option (cvt->parser->long_opts, opt->name) < 0)
		  /* OPT can be used as a long option.  */
		  {
		    cvt->long_end->name = opt->name;
		    cvt->long_end->has_arg =
		      (real->arg
		       ? (real->flags & OPTION_ARG_OPTIONAL
			  ? optional_argument
			  : required_argument)
		       : no_argument);
		    cvt->long_end->flag = 0;
		    /* we add a disambiguating code to all the user's
		       values (which is removed before we actually call
		       the function to parse the value); this means that
		       the user loses use of the high 8 bits in all his
		       values (the sign of the lower bits is preserved
		       however)...  */
		    cvt->long_end->val =
		      ((opt->key | real->key) & USER_MASK)
		      + (((group - cvt->parser->groups) + 1) << USER_BITS);

		    /* Keep the LONG_OPTS list terminated.  */
		    (++cvt->long_end)->name = NULL;
		  }
	      }
	    }

      group->parser = argp->parser;
      group->argp = argp;
      group->short_end = cvt->short_end;
      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;
}

/* Find the merged set of getopt options, with keys appropiately prefixed. */
static void
parser_convert (struct parser *parser, const struct argp *argp, int flags)
{
  struct parser_convert_state cvt;

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

  if (flags & ARGP_IN_ORDER)
    *cvt.short_end++ = '-';
  else if (flags & ARGP_NO_ARGS)
    *cvt.short_end++ = '+';
  *cvt.short_end = '\0';

  cvt.long_end->name = NULL;

  parser->argp = argp;

  if (argp)
    parser->egroup = convert_options (argp, 0, 0, parser->groups, &cvt);
  else
    parser->egroup = parser->groups; /* No parsers at all! */
}

/* Lengths of various parser fields which we will allocated.  */
struct parser_sizes
{
  size_t short_len;		/* Getopt short options string.  */
  size_t long_len;		/* Getopt long options vector.  */
  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 & LONG_LEN fields by
 the maximum lengths of the resulting merged getopt short options string and
 long-options array, respectively.  */
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)
    {
      szs->num_groups++;
      if (opt)
	{
	  int num_opts = 0;
	  while (!__option_is_end (opt++))
	    num_opts++;
	  szs->short_len += num_opts * 3; /* opt + up to 2 `:'s */
	  szs->long_len += num_opts;
	}
    }

  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;
  struct _getopt_data opt_data = _GETOPT_DATA_INITIALIZER;
  char *storage;
  size_t glen, gsum;
  size_t clen, csum;
  size_t llen, lsum;
  size_t slen, ssum;

  szs.short_len = (flags & ARGP_NO_ARGS) ? 0 : 1;
  szs.long_len = 0;
  szs.num_groups = 0;
  szs.num_child_inputs = 0;

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