/* Hierarchical argument parsing help output
   Copyright (C) 1995-2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Written by Miles Bader <miles@gnu.ai.mit.edu>.

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

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

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

#ifndef _GNU_SOURCE
# define _GNU_SOURCE    1
#endif

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

#include <alloca.h>
#include <errno.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <assert.h>
#include <stdarg.h>
#include <ctype.h>
#include <limits.h>
#ifdef _LIBC
# include <../libio/libioP.h>
# include <wchar.h>
#endif

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

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

#ifndef SIZE_MAX
# define SIZE_MAX ((size_t) -1)
#endif

/* ========================================================================== */

/* User-selectable (using an environment variable) formatting parameters.

   These may be specified in an environment variable called 'ARGP_HELP_FMT',
   with a contents like:  VAR1=VAL1,VAR2=VAL2,BOOLVAR2,no-BOOLVAR2
   Where VALn must be a positive integer.  The list of variables is in the
   UPARAM_NAMES vector, below.  */

/* Default parameters.  */
#define DUP_ARGS      0         /* True if option argument can be duplicated. */
#define DUP_ARGS_NOTE 1         /* True to print a note about duplicate args. */
#define SHORT_OPT_COL 2         /* column in which short options start */
#define LONG_OPT_COL  6         /* column in which long options start */
#define DOC_OPT_COL   2         /* column in which doc options start */
#define OPT_DOC_COL  29         /* column in which option text starts */
#define HEADER_COL    1         /* column in which group headers are printed */
#define USAGE_INDENT 12         /* indentation of wrapped usage lines */
#define RMARGIN      79         /* right margin used for wrapping */

/* User-selectable (using an environment variable) formatting parameters.
   They must all be of type 'int' for the parsing code to work.  */
struct uparams
{
  /* If true, arguments for an option are shown with both short and long
     options, even when a given option has both, e.g. '-x ARG, --longx=ARG'.
     If false, then if an option has both, the argument is only shown with
     the long one, e.g., '-x, --longx=ARG', and a message indicating that
     this really means both is printed below the options.  */
  int dup_args;

  /* This is true if when DUP_ARGS is false, and some duplicate arguments have
     been suppressed, an explanatory message should be printed.  */
  int dup_args_note;

  /* Various output columns.  */
  int short_opt_col;      /* column in which short options start */
  int long_opt_col;       /* column in which long options start */
  int doc_opt_col;        /* column in which doc options start */
  int opt_doc_col;        /* column in which option text starts */
  int header_col;         /* column in which group headers are printed */
  int usage_indent;       /* indentation of wrapped usage lines */
  int rmargin;            /* right margin used for wrapping */

  int valid;              /* True when the values in here are valid.  */
};

/* This is a global variable, as user options are only ever read once.  */
static struct uparams uparams = {
  DUP_ARGS, DUP_ARGS_NOTE,
  SHORT_OPT_COL, LONG_OPT_COL, DOC_OPT_COL, OPT_DOC_COL, HEADER_COL,
  USAGE_INDENT, RMARGIN
};

/* A particular uparam, and what the user name is.  */
struct uparam_name
{
  const char name[14];          /* User name.  */
  bool is_bool;                 /* Whether it's 'boolean'.  */
  unsigned char uparams_offs;   /* Location of the (int) field in UPARAMS.  */
};

/* The name-field mappings we know about.  */
static const struct uparam_name uparam_names[] =
{
  { "dup-args",       true, offsetof (struct uparams, dup_args) },
  { "dup-args-note",  true, offsetof (struct uparams, dup_args_note) },
  { "short-opt-col",  false, offsetof (struct uparams, short_opt_col) },
  { "long-opt-col",   false, offsetof (struct uparams, long_opt_col) },
  { "doc-opt-col",    false, offsetof (struct uparams, doc_opt_col) },
  { "opt-doc-col",    false, offsetof (struct uparams, opt_doc_col) },
  { "header-col",     false, offsetof (struct uparams, header_col) },
  { "usage-indent",   false, offsetof (struct uparams, usage_indent) },
  { "rmargin",        false, offsetof (struct uparams, rmargin) }
};
#define nuparam_names (sizeof (uparam_names) / sizeof (uparam_names[0]))

static void
validate_uparams (const struct argp_state *state, struct uparams *upptr)
{
  const struct uparam_name *up;

  for (up = uparam_names; up < uparam_names + nuparam_names; up++)
    {
      if (up->is_bool
          || up->uparams_offs == offsetof (struct uparams, rmargin))
        continue;
      if (*(int *)((char *)upptr + up->uparams_offs) >= upptr->rmargin)
        {
          __argp_failure (state, 0, 0,
                          dgettext (state == NULL ? NULL
                                    : state->root_argp->argp_domain,
                                    "\
ARGP_HELP_FMT: %s value is less than or equal to %s"),
                          "rmargin", up->name);
          return;
        }
    }
  uparams = *upptr;
  uparams.valid = 1;
}

/* Read user options from the environment, and fill in UPARAMS appropriately.  */
static void
fill_in_uparams (const struct argp_state *state)
{
  const char *var = getenv ("ARGP_HELP_FMT");
  struct uparams new_params = uparams;

#define SKIPWS(p) do { while (isspace ((unsigned char) *p)) p++; } while (0);

  if (var)
    {
      /* Parse var. */
      while (*var)
        {
          SKIPWS (var);

          if (isalpha ((unsigned char) *var))
            {
              size_t var_len;
              const struct uparam_name *un;
              int unspec = 0, val = 0;
              const char *arg = var;

              while (isalnum ((unsigned char) *arg) || *arg == '-' || *arg == '_')
                arg++;
              var_len = arg - var;

              SKIPWS (arg);

              if (*arg == '\0' || *arg == ',')
                unspec = 1;
              else if (*arg == '=')
                {
                  arg++;
                  SKIPWS (arg);
                }

              if (unspec)
                {
                  if (var[0] == 'n' && var[1] == 'o' && var[2] == '-')
                    {
                      val = 0;
                      var += 3;
                      var_len -= 3;
                    }
                  else
                    val = 1;
                }
              else if (isdigit ((unsigned char) *arg))
                {
                  val = atoi (arg);
                  while (isdigit ((unsigned char) *arg))
                    arg++;
                  SKIPWS (arg);
                }

              for (un = uparam_names;
                   un < uparam_names + nuparam_names;
                   un++)
                if (strlen (un->name) == var_len
                    && strncmp (var, un->name, var_len) == 0)
                  {
                    if (unspec && !un->is_bool)
                      __argp_failure (state, 0, 0,
                                      dgettext (state == NULL ? NULL
                                                : state->root_argp->argp_domain,
                                                "\
%.*s: ARGP_HELP_FMT parameter requires a value"),
                                      (int) var_len, var);
                    else
                      *(int *)((char *)&new_params + un->uparams_offs) = val;
                    break;
                  }
              if (un == uparam_names + nuparam_names)
                __argp_failure (state, 0, 0,
                                dgettext (state == NULL ? NULL
                                          : state->root_argp->argp_domain, "\
%.*s: Unknown ARGP_HELP_FMT parameter"),
                                (int) var_len, var);

              var = arg;
              if (*var == ',')
                var++;
            }
          else if (*var)
            {
              __argp_failure (state, 0, 0,
                              dgettext (state == NULL ? NULL
                                        : state->root_argp->argp_domain,
                                        "Garbage in ARGP_HELP_FMT: %s"), var);
              break;
            }
        }
      validate_uparams (state, &new_params);
    }
}

/* ========================================================================== */

/* Returns true if OPT hasn't been marked invisible.  Visibility only affects
   whether OPT is displayed or used in sorting, not option shadowing.  */
#define ovisible(opt) (! ((opt)->flags & OPTION_HIDDEN))

/* Returns true if OPT is an alias for an earlier option.  */
#define oalias(opt) ((opt)->flags & OPTION_ALIAS)

/* Returns true if OPT is a documentation-only entry.  */
#define odoc(opt) ((opt)->flags & OPTION_DOC)

/* Returns true if OPT should not be translated */
#define onotrans(opt) ((opt)->flags & OPTION_NO_TRANS)

/* Returns true if OPT is the end-of-list marker for a list of options.  */
#define oend(opt) __option_is_end (opt)

/* Returns true if OPT has a short option.  */
#define oshort(opt) __option_is_short (opt)

/*
   The help format for a particular option is like:

     -xARG, -yARG, --long1=ARG, --long2=ARG        Documentation...

   Where ARG will be omitted if there's no argument, for this option, or
   will be surrounded by "[" and "]" appropriately if the argument is
   optional.  The documentation string is word-wrapped appropriately, and if
   the list of options is long enough, it will be started on a separate line.
   If there are no short options for a given option, the first long option is
   indented slightly in a way that's supposed to make most long options appear
   to be in a separate column.

   For example, the following output (from ps):

     -p PID, --pid=PID          List the process PID
         --pgrp=PGRP            List processes in the process group PGRP
     -P, -x, --no-parent        Include processes without parents
     -Q, --all-fields           Don't elide unusable fields (normally if there's
                                some reason ps can't print a field for any
                                process, it's removed from the output entirely)
     -r, --reverse, --gratuitously-long-reverse-option
                                Reverse the order of any sort
         --session[=SID]        Add the processes from the session SID (which
                                defaults to the sid of the current process)

    Here are some more options:
     -f ZOT, --foonly=ZOT       Glork a foonly
     -z, --zaza                 Snit a zar

     -?, --help                 Give this help list
         --usage                Give a short usage message
     -V, --version              Print program version

   The struct argp_option array for the above could look like:

   {
     {"pid",       'p',      "PID",  0, "List the process PID"},
     {"pgrp",      OPT_PGRP, "PGRP", 0, "List processes in the process group PGRP"},
     {"no-parent", 'P',       0,     0, "Include processes without parents"},
     {0,           'x',       0,     OPTION_ALIAS},
     {"all-fields",'Q',       0,     0, "Don't elide unusable fields (normally"
                                        " if there's some reason ps can't"
                                        " print a field for any process, it's"
                                        " removed from the output entirely)" },
     {"reverse",   'r',       0,     0, "Reverse the order of any sort"},
     {"gratuitously-long-reverse-option", 0, 0, OPTION_ALIAS},
     {"session",   OPT_SESS,  "SID", OPTION_ARG_OPTIONAL,
                                        "Add the processes from the session"
                                        " SID (which defaults to the sid of"
                                        " the current process)" },

     {0,0,0,0, "Here are some more options:"},
     {"foonly", 'f', "ZOT", 0, "Glork a foonly"},
     {"zaza", 'z', 0, 0, "Snit a zar"},

     {0}
   }

   Note that the last three options are automatically supplied by argp_parse,
   unless you tell it not to with ARGP_NO_HELP.

*/

/* Returns true if CH occurs between BEG and END.  */
static int
find_char (char ch, char *beg, char *end)
{
  while (beg < end)
    if (*beg == ch)
      return 1;
    else
      beg++;
  return 0;
}

/* -------------------------------------------------------------------------- */
/* Data structure: HOL = Help Option List                                     */

struct hol_cluster;             /* fwd decl */

struct hol_entry
{
  /* First option.  */
  const struct argp_option *opt;
  /* Number of options (including aliases).  */
  unsigned num;

  /* A pointers into the HOL's short_options field, to the first short option
     letter for this entry.  The order of the characters following this point
     corresponds to the order of options pointed to by OPT, and there are at
     most NUM.  A short option recorded in an option following OPT is only
     valid if it occurs in the right place in SHORT_OPTIONS (otherwise it's
     probably been shadowed by some other entry).  */
  char *short_options;

  /* Entries are sorted by their group first, in the order:
       0, 1, 2, ..., n, -m, ..., -2, -1
     and then alphabetically within each group.  The default is 0.  */
  int group;

  /* The cluster of options this entry belongs to, or NULL if none.  */
  struct hol_cluster *cluster;

  /* The argp from which this option came.  */
  const struct argp *argp;

  /* Position in the array */
  unsigned ord;
};

/* A cluster of entries to reflect the argp tree structure.  */
struct hol_cluster
{
  /* A descriptive header printed before options in this cluster.  */
  const char *header;

  /* Used to order clusters within the same group with the same parent,
     according to the order in which they occurred in the parent argp's child
     list.  */
  int index;

  /* How to sort this cluster with respect to options and other clusters at the
     same depth (clusters always follow options in the same group).  */
  int group;

  /* The cluster to which this cluster belongs, or NULL if it's at the base
     level.  */
  struct hol_cluster *parent;

  /* The argp from which this cluster is (eventually) derived.  */
  const struct argp *argp;

  /* The distance this cluster is from the root.  */
  int depth;

  /* Clusters in a given hol are kept in a linked list, to make freeing them
     possible.  */
  struct hol_cluster *next;
};

/* A list of options for help.  */
struct hol
{
  /* An array of hol_entry's.  */
  struct hol_entry *entries;
  /* The number of entries in this hol.  If this field is zero, the others
     are undefined.  */
  unsigned num_entries;

  /* A string containing all short options in this HOL.  Each entry contains
     pointers into this string, so the order can't be messed with blindly.  */
  char *short_options;

  /* Clusters of entries in this hol.  */
  struct hol_cluster *clusters;
};

/* Create a struct hol from the options in ARGP.  CLUSTER is the
   hol_cluster in which these entries occur, or NULL if at the root.  */
static struct hol *
make_hol (const struct argp *argp, struct hol_cluster *cluster)
{
  char *so;
  const struct argp_option *o;
  const struct argp_option *opts = argp->options;
  struct hol_entry *entry;
  unsigned num_short_options = 0;
  struct hol *hol = malloc (sizeof (struct hol));

  assert (hol);

  hol->num_entries = 0;
  hol->clusters = 0;

  if (opts)
    {
      int cur_group = 0;

      /* The first option must not be an alias.  */
      assert (! oalias (opts));

      /* Calculate the space needed.  */
      for (o = opts; ! oend (o); o++)
        {
          if (! oalias (o))
            hol->num_entries++;
          if (oshort (o))
            num_short_options++;        /* This is an upper bound.  */
        }

      hol->entries = malloc (sizeof (struct hol_entry) * hol->num_entries);
      hol->short_options = malloc (num_short_options + 1);

      assert (hol->entries && hol->short_options);
      if (SIZE_MAX <= UINT_MAX)
        assert (hol->num_entries <= SIZE_MAX / sizeof (struct hol_entry));

      /* Fill in the entries.  */
      so = hol->short_options;
      for (o = opts, entry = hol->entries; ! oend (o); entry++)
        {
          entry->opt = o;
          entry->num = 0;
          entry->short_options = so;
          entry->group = cur_group =
            o->group
            ? o->group
            : ((!o->name && !o->key)
               ? cur_group + 1
               : cur_group);
          entry->cluster = cluster;
          entry->argp = argp;

          do
            {
              entry->num++;
              if (oshort (o) && ! find_char (o->key, hol->short_options, so))
                /* O has a valid short option which hasn't already been used.*/
                *so++ = o->key;
              o++;
            }
          while (! oend (o) && oalias (o));
        }
      *so = '\0';               /* null terminated so we can find the length */
    }

  return hol;
}

/* Add a new cluster to HOL, with the given GROUP and HEADER (taken from the
   associated argp child list entry), INDEX, and PARENT, and return a pointer
   to it.  ARGP is the argp that this cluster results from.  */
static struct hol_cluster *
hol_add_cluster (struct hol *hol, int group, const char *header, int index,
                 struct hol_cluster *parent, const struct argp *argp)
{
  struct hol_cluster *cl = malloc (sizeof (struct hol_cluster));
  if (cl)
    {
      cl->group = group;
      cl->header = header;

      cl->index = index;
      cl->parent = parent;
      cl->argp = argp;
      cl->depth = parent ? parent->depth + 1 : 0;

      cl->next = hol->clusters;
      hol->clusters = cl;
    }
  return cl;
}

/* Free HOL and any resources it uses.  */
static void
hol_free (struct hol *hol)
{
  struct hol_cluster *cl = hol->clusters;

  while (cl)
    {
      struct hol_cluster *next = cl->next;
      free (cl);
      cl = next;
    }

  if (hol->num_entries > 0)
    {
      free (hol->entries);
      free (hol->short_options);
    }

  free (hol);
}

/* Iterate across the short_options of the given ENTRY.  Call FUNC for each.
   Stop when such a call returns a non-zero value, and return this value.
   If all FUNC invocations returned 0, return 0.  */
static int
hol_entry_short_iterate (const struct hol_entry *entry,
                         int (*func)(const struct argp_option *opt,
                                     const struct argp_option *real,
                                     const char *domain, void *cookie),
                         const char *domain, void *cookie)
{
  unsigned nopts;
  int val = 0;
  const struct argp_option *opt, *real = entry->opt;
  char *so = entry->short_options;

  for (opt = real, nopts = entry->num; nopts > 0 && !val; opt++, nopts--)
    if (oshort (opt) && *so == opt->key)
      {
        if (!oalias (opt))
          real = opt;
        if (ovisible (opt))
          val = (*func)(opt, real, domain, cookie);
        so++;
      }

  return val;
}

/* Iterate across the long options of the given ENTRY.  Call FUNC for each.
   Stop when such a call returns a non-zero value, and return this value.
   If all FUNC invocations returned 0, return 0.  */
static inline int
#if (__GNUC__ >= 3) || (__clang_major__ >= 4)
__attribute__ ((always_inline))
#endif
hol_entry_long_iterate (const struct hol_entry *entry,
                        int (*func)(const struct argp_option *opt,
                                    const struct argp_option *real,
                                    const char *domain, void *cookie),
                        const char *domain, void *cookie)
{
  unsigned nopts;
  int val = 0;
  const struct argp_option *opt, *real = entry->opt;

  for (opt = real, nopts = entry->num; nopts > 0 && !val; opt++, nopts--)
    if (opt->name)
      {
        if (!oalias (opt))
          real = opt;
        if (ovisible (opt))
          val = (*func)(opt, real, domain, cookie);
      }

  return val;
}

/* A filter that returns true for the first short option of a given ENTRY.  */
static int
until_short (const struct argp_option *opt, const struct argp_option *real,
             const char *domain, void *cookie)
{
  return oshort (opt) ? opt->key : 0;
}

/* Returns the first valid short option in ENTRY, or 0 if there is none.  */
static char
hol_entry_first_short (const struct hol_entry *entry)
{
  return hol_entry_short_iterate (entry, until_short,
                                  entry->argp->argp_domain, 0);
}

/* Returns the first valid long option in ENTRY, or NULL if there is none.  */
static const char *
hol_entry_first_long (const struct hol_entry *entry)
{
  const struct argp_option *opt;
  unsigned num;
  for (opt = entry->opt, num = entry->num; num > 0; opt++, num--)
    if (opt->name && ovisible (opt))
      return opt->name;
  return 0;
}

/* Returns the entry in HOL with the long option name NAME, or NULL if there is
   none.  */
static struct hol_entry *
hol_find_entry (struct hol *hol, const char *name)
{
  struct hol_entry *entry = hol->entries;
  unsigned num_entries = hol->num_entries;

  while (num_entries-- > 0)
    {
      const struct argp_option *opt = entry->opt;
      unsigned num_opts = entry->num;

      while (num_opts-- > 0)
        if (opt->name && ovisible (opt) && strcmp (opt->name, name) == 0)
          return entry;
        else
          opt++;

      entry++;
    }

  return 0;
}

/* If an entry with the long option NAME occurs in HOL, set its special
   sort position to GROUP.  */
static void
hol_set_group (struct hol *hol, const char *name, int group)
{
  struct hol_entry *entry = hol_find_entry (hol, name);
  if (entry)
    entry->group = group;
}

/* -------------------------------------------------------------------------- */
/* Sorting the entries in a HOL.                                              */

/* Order by group:  0, 1, 2, ..., n, -m, ..., -2, -1.  */
static int
group_cmp (int group1, int group2)
{
  if ((group1 < 0 && group2 < 0) || (group1 >= 0 && group2 >= 0))
    return group1 - group2;
  else
    /* Return > 0 if group1 < 0 <= group2.
       Return < 0 if group2 < 0 <= group1.  */
    return group2 - group1;
}

/* Compare clusters CL1 and CL2 by the order that they should appear in
   output.  Assume CL1 and CL2 have the same parent.  */
static int
hol_sibling_cluster_cmp (const struct hol_cluster *cl1,
                         const struct hol_cluster *cl2)
{
  /* Compare by group first.  */
  int cmp = group_cmp (cl1->group, cl2->group);
  if (cmp != 0)
    return cmp;

  /* Within a group, compare by index within the group.  */
  return cl2->index - cl1->index;
}

/* Compare clusters CL1 and CL2 by the order that they should appear in
   output.  Assume CL1 and CL2 are at the same depth.  */
static int
hol_cousin_cluster_cmp (const struct hol_cluster *cl1,
                        const struct hol_cluster *cl2)
{
  if (cl1->parent == cl2->parent)
    return hol_sibling_cluster_cmp (cl1, cl2);
  else
    {
      /* Compare the parent clusters first.  */
      int cmp = hol_cousin_cluster_cmp (cl1->parent, cl2->parent);
      if (cmp != 0)
        return cmp;

      /* Next, compare by group.  */
      cmp = group_cmp (cl1->group, cl2->group);
      if (cmp != 0)
        return cmp;

      /* Next, within a group, compare by index within the group.  */
      return cl2->index - cl1->index;
    }
}

/* Compare clusters CL1 and CL2 by the order that they should appear in
   output.  */
static int
hol_cluster_cmp (const struct hol_cluster *cl1, const struct hol_cluster *cl2)
{
  /* If one cluster is deeper than the other, use its ancestor at the same
     level.  Then, go by the rule that entries that are not in a sub-cluster
     come before entries in a sub-cluster.  */
  if (cl1->depth > cl2->depth)
    {
      do
        cl1 = cl1->parent;
      while (cl1->depth > cl2->depth);
      int cmp = hol_cousin_cluster_cmp (cl1, cl2);
      if (cmp != 0)
        return cmp;

      return 1;
    }
  else if (cl1->depth < cl2->depth)
    {
      do
        cl2 = cl2->parent;
      while (cl1->depth < cl2->depth);
      int cmp = hol_cousin_cluster_cmp (cl1, cl2);
      if (cmp != 0)
        return cmp;

      return -1;
    }
  else
    return hol_cousin_cluster_cmp (cl1, cl2);
}

/* Return the ancestor of CL that's just below the root (i.e., has a parent
   of 0).  */
static struct hol_cluster *
hol_cluster_base (struct hol_cluster *cl)
{
  while (cl->parent)
    cl = cl->parent;
  return cl;
}

/* Given the name of an OPTION_DOC option, modifies *NAME to start at the tail
   that should be used for comparisons, and returns true iff it should be
   treated as a non-option.  */
static int
canon_doc_option (const char **name)
{
  int non_opt;
  /* Skip initial whitespace.  */
  while (isspace ((unsigned char) **name))
    (*name)++;
  /* Decide whether this looks like an option (leading '-') or not.  */
  non_opt = (**name != '-');
  /* Skip until part of name used for sorting.  */
  while (**name && !isalnum ((unsigned char) **name))
    (*name)++;
  return non_opt;
}

/* Order ENTRY1 and ENTRY2 by the order which they should appear in a help
   listing.
   This function implements a total order, that is:
     - if cmp (entry1, entry2) < 0 and cmp (entry2, entry3) < 0,
       then cmp (entry1, entry3) < 0.
     - if cmp (entry1, entry2) < 0 and cmp (entry2, entry3) == 0,
       then cmp (entry1, entry3) < 0.
     - if cmp (entry1, entry2) == 0 and cmp (entry2, entry3) < 0,
       then cmp (entry1, entry3) < 0.
     - if cmp (entry1, entry2) == 0 and cmp (entry2, entry3) == 0,
       then cmp (entry1, entry3) == 0.  */
static int
hol_entry_cmp (const struct hol_entry *entry1,
               const struct hol_entry *entry2)
{
  /* First, compare the group numbers.  For entries within a cluster, what
     matters is the group number of the base cluster in which the entry
     resides.  */
  int group1 = (entry1->cluster
                ? hol_cluster_base (entry1->cluster)->group
                : entry1->group);
  int group2 = (entry2->cluster
                ? hol_cluster_base (entry2->cluster)->group
                : entry2->group);
  int cmp = group_cmp (group1, group2);
  if (cmp != 0)
    return cmp;

  /* The group numbers are the same.  */

  /* Entries that are not in a cluster come before entries in a cluster.  */
  cmp = (entry1->cluster != NULL) - (entry2->cluster != NULL);
  if (cmp != 0)
    return cmp;

  /* Compare the clusters.  */
  if (entry1->cluster != NULL)
    {
      cmp = hol_cluster_cmp (entry1->cluster, entry2->cluster);
      if (cmp != 0)
        return cmp;
    }

  /* For entries in the same cluster, compare also the group numbers
     within the cluster.  */
  cmp = group_cmp (entry1->group, entry2->group);
  if (cmp != 0)
    return cmp;

  /* The entries are both in the same group and the same cluster.  */

  /* 'documentation' options always follow normal options (or documentation
     options that *look* like normal options).  */
  const char *long1 = hol_entry_first_long (entry1);
  const char *long2 = hol_entry_first_long (entry2);
  int doc1 =
    (odoc (entry1->opt) ? long1 != NULL && canon_doc_option (&long1) : 0);
  int doc2 =
    (odoc (entry2->opt) ? long2 != NULL && canon_doc_option (&long2) : 0);
  cmp = doc1 - doc2;
  if (cmp != 0)
    return cmp;

  /* Compare the entries alphabetically.  */

  /* First, compare the first character of the options.
     Put entries without *any* valid options (such as options with
     OPTION_HIDDEN set) first.  But as they're not displayed, it doesn't
     matter where they are.  */
  int short1 = hol_entry_first_short (entry1);
  int short2 = hol_entry_first_short (entry2);
  unsigned char first1 = short1 ? short1 : long1 != NULL ? *long1 : 0;
  unsigned char first2 = short2 ? short2 : long2 != NULL ? *long2 : 0;
  /* Compare ignoring case.  */
  /* Use tolower, not _tolower, since the latter has undefined behaviour
     for characters that are not uppercase letters.  */
  cmp = tolower (first1) - tolower (first2);
  if (cmp != 0)
    return cmp;
  /* When the options start with the same letter (ignoring case), lower-case
     comes first.  */
  cmp = first2 - first1;
  if (cmp != 0)
    return cmp;

  /* The first character of the options agree.  */

  /* Put entries with a short option before entries without a short option.  */
  cmp = (short1 != 0) - (short2 != 0);
  if (cmp != 0)
    return cmp;

  /* Compare entries without a short option by comparing the long option.  */
  if (short1 == 0)
    {
      cmp = (long1 != NULL) - (long2 != NULL);
      if (cmp != 0)
        return cmp;

      if (long1 != NULL)
        {
          cmp = __strcasecmp (long1, long2);
          if (cmp != 0)
            return cmp;
        }
    }

  /* We're out of comparison criteria.  At this point, if ENTRY1 != ENTRY2,
     the order of these entries will be unpredictable.  */
  return 0;
}

/* Variant of hol_entry_cmp with correct signature for qsort.  */
static int
hol_entry_qcmp (const void *entry1_v, const void *entry2_v)
{
  return hol_entry_cmp (entry1_v, entry2_v);
}

/* Sort HOL by group and alphabetically by option name (with short options
   taking precedence over long).  Since the sorting is for display purposes
   only, the shadowing of options isn't effected.  */
static void
hol_sort (struct hol *hol)
{
  if (hol->num_entries > 0)
    {
      unsigned i;
      struct hol_entry *e;
      for (i = 0, e = hol->entries; i < hol->num_entries; i++, e++)
        e->ord = i;

      qsort (hol->entries, hol->num_entries, sizeof (struct hol_entry),
             hol_entry_qcmp);
    }
}

/* -------------------------------------------------------------------------- */
/* Constructing the HOL.                                                      */

/* Append MORE to HOL, destroying MORE in the process.  Options in HOL shadow
   any in MORE with the same name.  */
static void
hol_append (struct hol *hol, struct hol *more)
{
  struct hol_cluster **cl_end = &hol->clusters;

  /* Steal MORE's cluster list, and add it to the end of HOL's.  */
  while (*cl_end)
    cl_end = &(*cl_end)->next;
  *cl_end = more->clusters;
  more->clusters = 0;

  /* Merge entries.  */
  if (more->num_entries > 0)
    {
      if (hol->num_entries == 0)
        {
          hol->num_entries = more->num_entries;
          hol->entries = more->entries;
          hol->short_options = more->short_options;
          more->num_entries = 0;        /* Mark MORE's fields as invalid.  */
        }
      else
        /* Append the entries in MORE to those in HOL, taking care to only add
           non-shadowed SHORT_OPTIONS values.  */
        {
          unsigned left;
          char *so, *more_so;
          struct hol_entry *e;
          unsigned num_entries = hol->num_entries + more->num_entries;
          struct hol_entry *entries =
            malloc (num_entries * sizeof (struct hol_entry));
          unsigned hol_so_len = strlen (hol->short_options);
          char *short_options =
            malloc (hol_so_len + strlen (more->short_options) + 1);

          assert (entries && short_options);
          if (SIZE_MAX <= UINT_MAX)
            assert (num_entries <= SIZE_MAX / sizeof (struct hol_entry));

          __mempcpy (__mempcpy (entries, hol->entries,
                                hol->num_entries * sizeof (struct hol_entry)),
                     more->entries,
                     more->num_entries * sizeof (struct hol_entry));

          __mempcpy (short_options, hol->short_options, hol_so_len);

          /* Fix up the short options pointers from HOL.  */
          for (e = entries, left = hol->num_entries; left > 0; e++, left--)
            e->short_options
              = short_options + (e->short_options - hol->short_options);

          /* Now add the short options from MORE, fixing up its entries
             too.  */
          so = short_options + hol_so_len;
          more_so = more->short_options;
          for (left = more->num_entries; left > 0; e++, left--)
            {
              int opts_left;
              const struct argp_option *opt;

              e->short_options = so;

              for (opts_left = e->num, opt = e->opt; opts_left; opt++, opts_left--)
                {
                  int ch = *more_so;
                  if (oshort (opt) && ch == opt->key)
                    /* The next short option in MORE_SO, CH, is from OPT.  */
                    {
                      if (! find_char (ch, short_options,
                                       short_options + hol_so_len))
                        /* The short option CH isn't shadowed by HOL's options,
                           so add it to the sum.  */
                        *so++ = ch;
                      more_so++;
                    }
                }
            }

          *so = '\0';

          free (hol->entries);
          free (hol->short_options);

          hol->entries = entries;
          hol->num_entries = num_entries;
          hol->short_options = short_options;
        }
    }

  hol_free (more);
}

/* Make a HOL containing all levels of options in ARGP.  CLUSTER is the
   cluster in which ARGP's entries should be clustered, or NULL.  */
static struct hol *
argp_hol (const struct argp *argp, struct hol_cluster *cluster)
{
  const struct argp_child *child = argp->children;
  struct hol *hol = make_hol (argp, cluster);
  if (child)
    while (child->argp)
      {
        struct hol_cluster *child_cluster =
          ((child->group || child->header)
           /* Put CHILD->argp within its own cluster.  */
           ? hol_add_cluster (hol, child->group, child->header,
                              child - argp->children, cluster, argp)
           /* Just merge it into the parent's cluster.  */
           : cluster);
        hol_append (hol, argp_hol (child->argp, child_cluster)) ;
        child++;
      }
  return hol;
}

/* -------------------------------------------------------------------------- */
/* Printing the HOL.                                                          */

/* Inserts enough spaces to make sure STREAM is at column COL.  */
static void
indent_to (argp_fmtstream_t stream, unsigned col)
{
  int needed = col - __argp_fmtstream_point (stream);
  while (needed-- > 0)
    __argp_fmtstream_putc (stream, ' ');
}

/* Output to STREAM either a space, or a newline if there isn't room for at
   least ENSURE characters before the right margin.  */
static void
space (argp_fmtstream_t stream, size_t ensure)
{
  if (__argp_fmtstream_point (stream) + ensure
      >= __argp_fmtstream_rmargin (stream))
    __argp_fmtstream_putc (stream, '\n');
  else
    __argp_fmtstream_putc (stream, ' ');
}

/* If the option REAL has an argument, we print it in using the printf
   format REQ_FMT or OPT_FMT depending on whether it's a required or
   optional argument.  */
static void
arg (const struct argp_option *real, const char *req_fmt, const char *opt_fmt,
     const char *domain, argp_fmtstream_t stream)
{
  if (real->arg)
    {
      if (real->flags & OPTION_ARG_OPTIONAL)
        __argp_fmtstream_printf (stream, opt_fmt,
                                 dgettext (domain, real->arg));
      else
        __argp_fmtstream_printf (stream, req_fmt,
                                 dgettext (domain, real->arg));
    }
}

/* Helper functions for hol_entry_help.  */

/* State used during the execution of hol_help.  */
struct hol_help_state
{
  /* PREV_ENTRY should contain the previous entry printed, or NULL.  */
  struct hol_entry *prev_entry;

  /* If an entry is in a different group from the previous one, and SEP_GROUPS
     is true, then a blank line will be printed before any output. */
  int sep_groups;

  /* True if a duplicate option argument was suppressed (only ever set if
     UPARAMS.dup_args is false).  */
  int suppressed_dup_arg;
};

/* Some state used while printing a help entry (used to communicate with
   helper functions).  See the doc for hol_entry_help for more info, as most
   of the fields are copied from its arguments.  */
struct pentry_state
{
  const struct hol_entry *entry;
  argp_fmtstream_t stream;
  struct hol_help_state *hhstate;

  /* True if nothing's been printed so far.  */
  int first;

  /* If non-zero, the state that was used to print this help.  */
  const struct argp_state *state;
};

/* If a user doc filter should be applied to DOC, do so.  */
static const char *
filter_doc (const char *doc, int key, const struct argp *argp,
            const struct argp_state *state)
{
  if (argp && argp->help_filter)
    /* We must apply a user filter to this output.  */
    {
      void *input = __argp_input (argp, state);
      return (*argp->help_filter) (key, doc, input);
    }
  else
    /* No filter.  */
    return doc;
}

/* Prints STR as a header line, with the margin lines set appropriately, and
   notes the fact that groups should be separated with a blank line.  ARGP is
   the argp that should dictate any user doc filtering to take place.  Note
   that the previous wrap margin isn't restored, but the left margin is reset
   to 0.  */
static void
print_header (const char *str, const struct argp *argp,
              struct pentry_state *pest)
{
  const char *tstr = str ? dgettext (argp->argp_domain, str) : NULL;
  const char *fstr = filter_doc (tstr, ARGP_KEY_HELP_HEADER, argp, pest->state);

  if (fstr)
    {
      if (*fstr)
        {
          if (pest->hhstate->prev_entry)
            /* Precede with a blank line.  */
            __argp_fmtstream_putc (pest->stream, '\n');
          indent_to (pest->stream, uparams.header_col);
          __argp_fmtstream_set_lmargin (pest->stream, uparams.header_col);
          __argp_fmtstream_set_wmargin (pest->stream, uparams.header_col);
          __argp_fmtstream_puts (pest->stream, fstr);
          __argp_fmtstream_set_lmargin (pest->stream, 0);
          __argp_fmtstream_putc (pest->stream, '\n');
        }

      pest->hhstate->sep_groups = 1; /* Separate subsequent groups. */
    }

  if (fstr != tstr)
    free ((char *) fstr);
}

/* Return true if CL1 is a child of CL2.  */
static int
hol_cluster_is_child (const struct hol_cluster *cl1,
                      const struct hol_cluster *cl2)
{
  while (cl1 && cl1 != cl2)
    cl1 = cl1->parent;
  return cl1 == cl2;
}

/* Inserts a comma if this isn't the first item on the line, and then makes
   sure we're at least to column COL.  If this *is* the first item on a line,
   prints any pending whitespace/headers that should precede this line. Also
   clears FIRST.  */
static void
comma (unsigned col, struct pentry_state *pest)
{
  if (pest->first)
    {
      const struct hol_entry *pe = pest->hhstate->prev_entry;
      const struct hol_cluster *cl = pest->entry->cluster;

      if (pest->hhstate->sep_groups && pe && pest->entry->group != pe->group)
        __argp_fmtstream_putc (pest->stream, '\n');

      if (cl && cl->header && *cl->header
          && (!pe
              || (pe->cluster != cl
                  && !hol_cluster_is_child (pe->cluster, cl))))
        /* If we're changing clusters, then this must be the start of the
           ENTRY's cluster unless that is an ancestor of the previous one
           (in which case we had just popped into a sub-cluster for a bit).
           If so, then print the cluster's header line.  */
        {
          int old_wm = __argp_fmtstream_wmargin (pest->stream);
          print_header (cl->header, cl->argp, pest);
          __argp_fmtstream_set_wmargin (pest->stream, old_wm);
        }

      pest->first = 0;
    }
  else
    __argp_fmtstream_puts (pest->stream, ", ");

  indent_to (pest->stream, col);
}

/* Print help for ENTRY to STREAM.  */
static void
hol_entry_help (struct hol_entry *entry, const struct argp_state *state,
                argp_fmtstream_t stream, struct hol_help_state *hhstate)
{
  unsigned num;
  const struct argp_option *real = entry->opt, *opt;
  char *so = entry->short_options;
  int have_long_opt = 0;        /* We have any long options.  */
  /* Saved margins.  */
  int old_lm = __argp_fmtstream_set_lmargin (stream, 0);
  int old_wm = __argp_fmtstream_wmargin (stream);
  /* PEST is a state block holding some of our variables that we'd like to
     share with helper functions.  */
  struct pentry_state pest = { entry, stream, hhstate, 1, state };

  if (! odoc (real))
    for (opt = real, num = entry->num; num > 0; opt++, num--)
      if (opt->name && ovisible (opt))
        {
          have_long_opt = 1;
          break;
        }

  /* First emit short options.  */
  __argp_fmtstream_set_wmargin (stream, uparams.short_opt_col); /* For truly bizarre cases. */
  for (opt = real, num = entry->num; num > 0; opt++, num--)
    if (oshort (opt) && opt->key == *so)
      /* OPT has a valid (non shadowed) short option.  */
      {
        if (ovisible (opt))
          {
            comma (uparams.short_opt_col, &pest);
            __argp_fmtstream_putc (stream, '-');
            __argp_fmtstream_putc (stream, *so);
            if (!have_long_opt || uparams.dup_args)
              arg (real, " %s", "[%s]",
                   state == NULL ? NULL : state->root_argp->argp_domain,
                   stream);
            else if (real->arg)
              hhstate->suppressed_dup_arg = 1;
          }
        so++;
      }

  /* Now, long options.  */
  if (odoc (real))
    /* A "documentation" option.  */
    {
      __argp_fmtstream_set_wmargin (stream, uparams.doc_opt_col);
      for (opt = real, num = entry->num; num > 0; opt++, num--)
        if (opt->name && ovisible (opt))
          {
            comma (uparams.doc_opt_col, &pest);
            /* Calling dgettext here isn't quite right, since sorting will
               have been done on the original; but documentation options
               should be pretty rare anyway...  */
            __argp_fmtstream_puts (stream,
                                   dgettext (state == NULL ? NULL
                                             : state->root_argp->argp_domain,
                                             opt->name));
          }
    }
  else
    /* A real long option.  */
    {
      __argp_fmtstream_set_wmargin (stream, uparams.long_opt_col);
      for (opt = real, num = entry->num; num > 0; opt++, num--)
        if (opt->name && ovisible (opt))
          {
            comma (uparams.long_opt_col, &pest);
            __argp_fmtstream_printf (stream, "--%s", opt->name);
            arg (real, "=%s", "[=%s]",
                 state == NULL ? NULL : state->root_argp->argp_domain, stream);
          }
    }

  /* Next, documentation strings.  */
  __argp_fmtstream_set_lmargin (stream, 0);

  if (pest.first)
    {
      /* Didn't print any switches, what's up?  */
      if (!oshort (real) && !real->name)
        /* This is a group header, print it nicely.  */
        print_header (real->doc, entry->argp, &pest);
      else
        /* Just a totally shadowed option or null header; print nothing.  */
        goto cleanup;           /* Just return, after cleaning up.  */
    }
  else
    {
      const char *tstr = real->doc ? dgettext (state == NULL ? NULL
                                               : state->root_argp->argp_domain,
                                               real->doc) : 0;
      const char *fstr = filter_doc (tstr, real->key, entry->argp, state);
      if (fstr && *fstr)
        {
          unsigned int col = __argp_fmtstream_point (stream);

          __argp_fmtstream_set_lmargin (stream, uparams.opt_doc_col);
          __argp_fmtstream_set_wmargin (stream, uparams.opt_doc_col);

          if (col > (unsigned int) (uparams.opt_doc_col + 3))
            __argp_fmtstream_putc (stream, '\n');
          else if (col >= (unsigned int) uparams.opt_doc_col)
            __argp_fmtstream_puts (stream, "   ");
          else
            indent_to (stream, uparams.opt_doc_col);

          __argp_fmtstream_puts (stream, fstr);
        }
      if (fstr && fstr != tstr)
        free ((char *) fstr);

      /* Reset the left margin.  */
      __argp_fmtstream_set_lmargin (stream, 0);
      __argp_fmtstream_putc (stream, '\n');
    }

  hhstate->prev_entry = entry;

cleanup:
  __argp_fmtstream_set_lmargin (stream, old_lm);
  __argp_fmtstream_set_wmargin (stream, old_wm);
}

/* Output a long help message about the options in HOL to STREAM.  */
static void
hol_help (struct hol *hol, const struct argp_state *state,
          argp_fmtstream_t stream)
{
  unsigned num;
  struct hol_entry *entry;
  struct hol_help_state hhstate = { 0, 0, 0 };

  for (entry = hol->entries, num = hol->num_entries; num > 0; entry++, num--)
    hol_entry_help (entry, state, stream, &hhstate);

  if (hhstate.suppressed_dup_arg && uparams.dup_args_note)
    {
      const char *tstr = dgettext (state == NULL ? NULL
                                   : state->root_argp->argp_domain, "\
Mandatory or optional arguments to long options are also mandatory or \
optional for any corresponding short options.");
      const char *fstr = filter_doc (tstr, ARGP_KEY_HELP_DUP_ARGS_NOTE,
                                     state ? state->root_argp : 0, state);
      if (fstr && *fstr)
        {
          __argp_fmtstream_putc (stream, '\n');
          __argp_fmtstream_puts (stream, fstr);
          __argp_fmtstream_putc (stream, '\n');
        }
      if (fstr && fstr != tstr)
        free ((char *) fstr);
    }
}

/* Helper functions for hol_usage.  */

/* If OPT is a short option without an arg, append its key to the string
   pointer pointer to by COOKIE, and advance the pointer.  */
static int
add_argless_short_opt (const struct argp_option *opt,
                       const struct argp_option *real,
                       const char *domain, void *cookie)
{
  char **snao_end = cookie;
  if (!(opt->arg || real->arg)
      && !((opt->flags | real->flags) & OPTION_NO_USAGE))
    *(*snao_end)++ = opt->key;
  return 0;
}

/* If OPT is a short option with an arg, output a usage entry for it to the
   stream pointed at by COOKIE.  */
static int
usage_argful_short_opt (const struct argp_option *opt,
                        const struct argp_option *real,
                        const char *domain, void *cookie)
{
  argp_fmtstream_t stream = cookie;
  const char *arg = opt->arg;
  int flags = opt->flags | real->flags;

  if (! arg)
    arg = real->arg;

  if (arg && !(flags & OPTION_NO_USAGE))
    {
      arg = dgettext (domain, arg);

      if (flags & OPTION_ARG_OPTIONAL)
        __argp_fmtstream_printf (stream, " [-%c[%s]]", opt->key, arg);
      else
        {
          /* Manually do line wrapping so that it (probably) won't
             get wrapped at the embedded space.  */
          space (stream, 6 + strlen (arg));
          __argp_fmtstream_printf (stream, "[-%c %s]", opt->key, arg);
        }
    }

  return 0;
}

/* Output a usage entry for the long option opt to the stream pointed at by
   COOKIE.  */
static int
usage_long_opt (const struct argp_option *opt,
                const struct argp_option *real,
                const char *domain, void *cookie)
{
  argp_fmtstream_t stream = cookie;
  const char *arg = opt->arg;
  int flags = opt->flags | real->flags;

  if (! arg)
    arg = real->arg;

  if (! (flags & OPTION_NO_USAGE))
    {
      if (arg)
        {
          arg = dgettext (domain, arg);
          if (flags & OPTION_ARG_OPTIONAL)
            __argp_fmtstream_printf (stream, " [--%s[=%s]]", opt->name, arg);
          else
            __argp_fmtstream_printf (stream, " [--%s=%s]", opt->name, arg);
        }
      else
        __argp_fmtstream_printf (stream, " [--%s]", opt->name);
    }

  return 0;
}

/* Print a short usage description for the arguments in HOL to STREAM.  */
static void
hol_usage (struct hol *hol, argp_fmtstream_t stream)
{
  if (hol->num_entries > 0)
    {
      unsigned nentries;
      struct hol_entry *entry;
      char *short_no_arg_opts = alloca (strlen (hol->short_options) + 1);
      char *snao_end = short_no_arg_opts;

      /* First we put a list of short options without arguments.  */
      for (entry = hol->entries, nentries = hol->num_entries
           ; nentries > 0
           ; entry++, nentries--)
        hol_entry_short_iterate (entry, add_argless_short_opt,
                                 entry->argp->argp_domain, &snao_end);
      if (snao_end > short_no_arg_opts)
        {
          *snao_end++ = 0;
          __argp_fmtstream_printf (stream, " [-%s]", short_no_arg_opts);
        }

      /* Now a list of short options *with* arguments.  */
      for (entry = hol->entries, nentries = hol->num_entries
           ; nentries > 0
           ; entry++, nentries--)
        hol_entry_short_iterate (entry, usage_argful_short_opt,
                                 entry->argp->argp_domain, stream);

      /* Finally, a list of long options (whew!).  */
      for (entry = hol->entries, nentries = hol->num_entries
           ; nentries > 0
           ; entry++, nentries--)
        hol_entry_long_iterate (entry, usage_long_opt,
                                entry->argp->argp_domain, stream);
    }
}

/* Calculate how many different levels with alternative args strings exist in
   ARGP.  */
static size_t
argp_args_levels (const struct argp *argp)
{
  size_t levels = 0;
  const struct argp_child *child = argp->children;

  if (argp->args_doc && strchr (argp->args_doc, '\n'))
    levels++;

  if (child)
    while (child->argp)
      levels += argp_args_levels ((child++)->argp);

  return levels;
}

/* Print all the non-option args documented in ARGP to STREAM.  Any output is
   preceded by a space.  LEVELS is a pointer to a byte vector the length
   returned by argp_args_levels; it should be initialized to zero, and
   updated by this routine for the next call if ADVANCE is true.  True is
   returned as long as there are more patterns to output.  */
static int
argp_args_usage (const struct argp *argp, const struct argp_state *state,
                 char **levels, int advance, argp_fmtstream_t stream)
{
  char *our_level = *levels;
  int multiple = 0;
  const struct argp_child *child = argp->children;
  const char *tdoc =
    argp->args_doc ? dgettext (argp->argp_domain, argp->args_doc) : NULL;
  const char *fdoc = filter_doc (tdoc, ARGP_KEY_HELP_ARGS_DOC, argp, state);
  const char *nl = NULL;

  if (fdoc)
    {
      const char *cp = fdoc;
      nl = __strchrnul (cp, '\n');
      if (*nl != '\0')
        /* This is a 'multi-level' args doc; advance to the correct position
           as determined by our state in LEVELS, and update LEVELS.  */
        {
          int i;
          multiple = 1;
          for (i = 0; i < *our_level; i++)
            cp = nl + 1, nl = __strchrnul (cp, '\n');
          (*levels)++;
        }

      /* Manually do line wrapping so that it (probably) won't get wrapped at
         any embedded spaces.  */
      space (stream, 1 + nl - cp);

      __argp_fmtstream_write (stream, cp, nl - cp);
    }
  if (fdoc && fdoc != tdoc)
    free ((char *)fdoc);        /* Free user's modified doc string.  */

  if (child)
    while (child->argp)
      advance = !argp_args_usage ((child++)->argp, state, levels, advance, stream);

  if (advance && multiple)
    {
      /* Need to increment our level.  */
      if (*nl)
        /* There's more we can do here.  */
        {
          (*our_level)++;
          advance = 0;          /* Our parent shouldn't advance also. */
        }
      else if (*our_level > 0)
        /* We had multiple levels, but used them up; reset to zero.  */
        *our_level = 0;
    }

  return !advance;
}

/* Print the documentation for ARGP to STREAM; if POST is false, then
   everything preceding a '\v' character in the documentation strings (or
   the whole string, for those with none) is printed, otherwise, everything
   following the '\v' character (nothing for strings without).  Each separate
   bit of documentation is separated a blank line, and if PRE_BLANK is true,
   then the first is as well.  If FIRST_ONLY is true, only the first
   occurrence is output.  Returns true if anything was output.  */
static int
argp_doc (const struct argp *argp, const struct argp_state *state,
          int post, int pre_blank, int first_only,
          argp_fmtstream_t stream)
{
  const char *text;
  const char *inp_text;
  void *input = 0;
  int anything = 0;
  size_t inp_text_limit = 0;
  const char *doc = argp->doc ? dgettext (argp->argp_domain, argp->doc) : NULL;
  const struct argp_child *child = argp->children;

  if (doc)
    {
      char *vt = strchr (doc, '\v');
      inp_text = post ? (vt ? vt + 1 : 0) : doc;
      inp_text_limit = (!post && vt) ? (vt - doc) : 0;
    }
  else
    inp_text = 0;

  if (argp->help_filter)
    /* We have to filter the doc strings.  */
    {
      if (inp_text_limit)
        /* Copy INP_TEXT so that it's nul-terminated.  */
        inp_text = __strndup (inp_text, inp_text_limit);
      input = __argp_input (argp, state);
      text =
        (*argp->help_filter) (post
                              ? ARGP_KEY_HELP_POST_DOC
                              : ARGP_KEY_HELP_PRE_DOC,
                              inp_text, input);
    }
  else
    text = (const char *) inp_text;

  if (text)
    {
      if (pre_blank)
        __argp_fmtstream_putc (stream, '\n');

      if (text == inp_text && inp_text_limit)
        __argp_fmtstream_write (stream, inp_text, inp_text_limit);
      else
        __argp_fmtstream_puts (stream, text);

      if (__argp_fmtstream_point (stream) > __argp_fmtstream_lmargin (stream))
        __argp_fmtstream_putc (stream, '\n');

      anything = 1;
    }

  if (text && text != inp_text)
    free ((char *) text);       /* Free TEXT returned from the help filter.  */
  if (inp_text && inp_text_limit && argp->help_filter)
    free ((char *) inp_text);   /* We copied INP_TEXT, so free it now.  */

  if (post && argp->help_filter)
    /* Now see if we have to output a ARGP_KEY_HELP_EXTRA text.  */
    {
      text = (*argp->help_filter) (ARGP_KEY_HELP_EXTRA, 0, input);
      if (text)
        {
          if (anything || pre_blank)
            __argp_fmtstream_putc (stream, '\n');
          __argp_fmtstream_puts (stream, text);
          free ((char *) text);
          if (__argp_fmtstream_point (stream)
              > __argp_fmtstream_lmargin (stream))
            __argp_fmtstream_putc (stream, '\n');
          anything = 1;
        }
    }

  if (child)
    while (child->argp && !(first_only && anything))
      anything |=
        argp_doc ((child++)->argp, state,
                  post, anything || pre_blank, first_only,
                  stream);

  return anything;
}

/* Output a usage message for ARGP to STREAM.  If called from
   argp_state_help, STATE is the relevant parsing state.  FLAGS are from the
   set ARGP_HELP_*.  NAME is what to use wherever a 'program name' is
   needed. */
static void
_help (const struct argp *argp, const struct argp_state *state, FILE *stream,
       unsigned flags, char *name)
{
  int anything = 0;             /* Whether we've output anything.  */
  struct hol *hol = 0;
  argp_fmtstream_t fs;

  if (! stream)
    return;

#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)
  __flockfile (stream);
#endif

  if (! uparams.valid)
    fill_in_uparams (state);

  fs = __argp_make_fmtstream (stream, 0, uparams.rmargin, 0);
  if (! fs)
    {
#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)
      __funlockfile (stream);
#endif
      return;
    }

  if (flags & (ARGP_HELP_USAGE | ARGP_HELP_SHORT_USAGE | ARGP_HELP_LONG))
    {
      hol = argp_hol (argp, 0);

      /* If present, these options always come last.  */
      hol_set_group (hol, "help", -1);
      hol_set_group (hol, "version", -1);

      hol_sort (hol);
    }

  if (flags & (ARGP_HELP_USAGE | ARGP_HELP_SHORT_USAGE))
    /* Print a short "Usage:" message.  */
    {
      int first_pattern = 1, more_patterns;
      size_t num_pattern_levels = argp_args_levels (argp);
      char *pattern_levels = alloca (num_pattern_levels);

      memset (pattern_levels, 0, num_pattern_levels);

      do
        {
          int old_lm;
          int old_wm = __argp_fmtstream_set_wmargin (fs, uparams.usage_indent);
          char *levels = pattern_levels;

          if (first_pattern)
            __argp_fmtstream_printf (fs, "%s %s",
                                     dgettext (argp->argp_domain, "Usage:"),
                                     name);
          else
            __argp_fmtstream_printf (fs, "%s %s",
                                     dgettext (argp->argp_domain, "  or: "),
                                     name);

          /* We set the lmargin as well as the wmargin, because hol_usage
             manually wraps options with newline to avoid annoying breaks.  */
          old_lm = __argp_fmtstream_set_lmargin (fs, uparams.usage_indent);

          if (flags & ARGP_HELP_SHORT_USAGE)
            /* Just show where the options go.  */
            {
              if (hol->num_entries > 0)
                __argp_fmtstream_puts (fs, dgettext (argp->argp_domain,
                                                     " [OPTION...]"));
            }
          else
            /* Actually print the options.  */
            {
              hol_usage (hol, fs);
              flags |= ARGP_HELP_SHORT_USAGE; /* But only do so once.  */
            }

          more_patterns = argp_args_usage (argp, state, &levels, 1, fs);

          __argp_fmtstream_set_wmargin (fs, old_wm);
          __argp_fmtstream_set_lmargin (fs, old_lm);

          __argp_fmtstream_putc (fs, '\n');
          anything = 1;

          first_pattern = 0;
        }
      while (more_patterns);
    }

  if (flags & ARGP_HELP_PRE_DOC)
    anything |= argp_doc (argp, state, 0, 0, 1, fs);

  if (flags & ARGP_HELP_SEE)
    {
      __argp_fmtstream_printf (fs, dgettext (argp->argp_domain, "\
Try '%s --help' or '%s --usage' for more information.\n"),
                               name, name);
      anything = 1;
    }

  if (flags & ARGP_HELP_LONG)
    /* Print a long, detailed help message.  */
    {
      /* Print info about all the options.  */
      if (hol->num_entries > 0)
        {
          if (anything)
            __argp_fmtstream_putc (fs, '\n');
          hol_help (hol, state, fs);
          anything = 1;
        }
    }

  if (flags & ARGP_HELP_POST_DOC)
    /* Print any documentation strings at the end.  */
    anything |= argp_doc (argp, state, 1, anything, 0, fs);

  if ((flags & ARGP_HELP_BUG_ADDR) && argp_program_bug_address)
    {
      if (anything)
        __argp_fmtstream_putc (fs, '\n');
      __argp_fmtstream_printf (fs, dgettext (argp->argp_domain,
                                             "Report bugs to %s.\n"),
                               argp_program_bug_address);
      anything = 1;
    }

#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)
  __funlockfile (stream);
#endif

  if (hol)
    hol_free (hol);

  __argp_fmtstream_free (fs);
}

/* Output a usage message for ARGP to STREAM.  FLAGS are from the set
   ARGP_HELP_*.  NAME is what to use wherever a 'program name' is needed. */
void __argp_help (const struct argp *argp, FILE *stream,
                  unsigned flags, char *name)
{
  _help (argp, 0, stream, flags, name);
}
#ifdef weak_alias
weak_alias (__argp_help, argp_help)
#endif

#if ! (defined _LIBC || HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME)
char *
__argp_short_program_name (void)
{
# if HAVE_DECL_PROGRAM_INVOCATION_NAME
  char *name = strrchr (program_invocation_name, '/');
  return name ? name + 1 : program_invocation_name;
# else
  /* FIXME: What now? Miles suggests that it is better to use NULL,
     but currently the value is passed on directly to fputs_unlocked,
     so that requires more changes. */
# if __GNUC__ || (__clang_major__ >= 4)
#  warning No reasonable value to return
# endif /* __GNUC__ */
  return "";
# endif
}
#endif

/* Output, if appropriate, a usage message for STATE to STREAM.  FLAGS are
   from the set ARGP_HELP_*.  */
void
__argp_state_help (const struct argp_state *state, FILE *stream, unsigned flags)
{
  if ((!state || ! (state->flags & ARGP_NO_ERRS)) && stream)
    {
      if (state && (state->flags & ARGP_LONG_ONLY))
        flags |= ARGP_HELP_LONG_ONLY;

      _help (state ? state->root_argp : 0, state, stream, flags,
             state ? state->name : __argp_short_program_name ());

      if (!state || ! (state->flags & ARGP_NO_EXIT))
        {
          if (flags & ARGP_HELP_EXIT_ERR)
            exit (argp_err_exit_status);
          if (flags & ARGP_HELP_EXIT_OK)
            exit (0);
        }
  }
}
#ifdef weak_alias
weak_alias (__argp_state_help, argp_state_help)
#endif

/* If appropriate, print the printf string FMT and following args, preceded
   by the program name and ':', to stderr, and followed by a "Try ... --help"
   message, then exit (1).  */
void
__argp_error (const struct argp_state *state, const char *fmt, ...)
{
  if (!state || !(state->flags & ARGP_NO_ERRS))
    {
      FILE *stream = state ? state->err_stream : stderr;

      if (stream)
        {
          va_list ap;

#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)
          __flockfile (stream);
#endif

          va_start (ap, fmt);

#ifdef _LIBC
          char *buf;

          if (_IO_vasprintf (&buf, fmt, ap) < 0)
            buf = NULL;

          __fxprintf (stream, "%s: %s\n",
                      state ? state->name : __argp_short_program_name (), buf);

          free (buf);
#else
          fputs_unlocked (state ? state->name : __argp_short_program_name (),
                          stream);
          putc_unlocked (':', stream);
          putc_unlocked (' ', stream);

          vfprintf (stream, fmt, ap);

          putc_unlocked ('\n', stream);
#endif

          __argp_state_help (state, stream, ARGP_HELP_STD_ERR);

          va_end (ap);

#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)
          __funlockfile (stream);
#endif
        }
    }
}
#ifdef weak_alias
weak_alias (__argp_error, argp_error)
#endif

/* Similar to the standard gnu error-reporting function error(), but will
   respect the ARGP_NO_EXIT and ARGP_NO_ERRS flags in STATE, and will print
   to STATE->err_stream.  This is useful for argument parsing code that is
   shared between program startup (when exiting is desired) and runtime
   option parsing (when typically an error code is returned instead).  The
   difference between this function and argp_error is that the latter is for
   *parsing errors*, and the former is for other problems that occur during
   parsing but don't reflect a (syntactic) problem with the input.  */
void
__argp_failure (const struct argp_state *state, int status, int errnum,
                const char *fmt, ...)
{
  if (!state || !(state->flags & ARGP_NO_ERRS))
    {
      FILE *stream = state ? state->err_stream : stderr;

      if (stream)
        {
#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)
          __flockfile (stream);
#endif

#ifdef _LIBC
          __fxprintf (stream, "%s",
                      state ? state->name : __argp_short_program_name ());
#else
          fputs_unlocked (state ? state->name : __argp_short_program_name (),
                          stream);
#endif

          if (fmt)
            {
              va_list ap;

              va_start (ap, fmt);
#ifdef _LIBC
              char *buf;

              if (_IO_vasprintf (&buf, fmt, ap) < 0)
                buf = NULL;

              __fxprintf (stream, ": %s", buf);

              free (buf);
#else
              putc_unlocked (':', stream);
              putc_unlocked (' ', stream);

              vfprintf (stream, fmt, ap);
#endif

              va_end (ap);
            }

          if (errnum)
            {
              char buf[200];

#ifdef _LIBC
              __fxprintf (stream, ": %s",
                          __strerror_r (errnum, buf, sizeof (buf)));
#else
              char const *s = NULL;
              putc_unlocked (':', stream);
              putc_unlocked (' ', stream);
# if GNULIB_STRERROR_R_POSIX || HAVE_DECL_STRERROR_R
#  if !GNULIB_STRERROR_R_POSIX && STRERROR_R_CHAR_P
              s = __strerror_r (errnum, buf, sizeof buf);
#  else
              if (__strerror_r (errnum, buf, sizeof buf) == 0)
                s = buf;
#  endif
# endif
              if (! s && ! (s = strerror (errnum)))
                s = dgettext (state->root_argp->argp_domain,
                              "Unknown system error");
              fputs_unlocked (s, stream);
#endif
            }

#if _LIBC
          if (_IO_fwide (stream, 0) > 0)
            putwc_unlocked (L'\n', stream);
          else
#endif
            putc_unlocked ('\n', stream);

#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)
          __funlockfile (stream);
#endif

          if (status && (!state || !(state->flags & ARGP_NO_EXIT)))
            exit (status);
        }
    }
}
#ifdef weak_alias
weak_alias (__argp_failure, argp_failure)
#endif
