[PATCH 22/57][Arm][GAS] Add support for MVE instructions: vmlaldav, vmlalv, vmlsldav...

[binutils-gdb.git] / sim / common / sim-options.c

/* Simulator option handling.
   Copyright (C) 1996-2019 Free Software Foundation, Inc.
   Contributed by Cygnus Support.

This file is part of GDB, the GNU debugger.

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/>.  */

#include "config.h"
#include "sim-main.h"
#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <ctype.h>
#include <stdio.h>
#include "libiberty.h"
#include "sim-options.h"
#include "sim-io.h"
#include "sim-assert.h"
#include "version.h"

#include "bfd.h"

/* Add a set of options to the simulator.
   TABLE is an array of OPTIONS terminated by a NULL `opt.name' entry.
   This is intended to be called by modules in their `install' handler.  */

SIM_RC
sim_add_option_table (SIM_DESC sd, sim_cpu *cpu, const OPTION *table)
{
  struct option_list *ol = ((struct option_list *)
                            xmalloc (sizeof (struct option_list)));

  /* Note: The list is constructed in the reverse order we're called so
     later calls will override earlier ones (in case that ever happens).
     This is the intended behaviour.  */

  if (cpu)
    {
      ol->next = CPU_OPTIONS (cpu);
      ol->options = table;
      CPU_OPTIONS (cpu) = ol;
    }
  else
    {
      ol->next = STATE_OPTIONS (sd);
      ol->options = table;
      STATE_OPTIONS (sd) = ol;
    }

  return SIM_RC_OK;
}

/* Standard option table.
   Modules may specify additional ones.
   The caller of sim_parse_args may also specify additional options
   by calling sim_add_option_table first.  */

static DECLARE_OPTION_HANDLER (standard_option_handler);

/* FIXME: We shouldn't print in --help output options that aren't usable.
   Some fine tuning will be necessary.  One can either move less general
   options to another table or use a HAVE_FOO macro to ifdef out unavailable
   options.  */

/* ??? One might want to conditionally compile out the entries that
   aren't enabled.  There's a distinction, however, between options a
   simulator can't support and options that haven't been configured in.
   Certainly options a simulator can't support shouldn't appear in the
   output of --help.  Whether the same thing applies to options that haven't
   been configured in or not isn't something I can get worked up over.
   [Note that conditionally compiling them out might simply involve moving
   the option to another table.]
   If you decide to conditionally compile them out as well, delete this
   comment and add a comment saying that that is the rule.  */

typedef enum {
  OPTION_DEBUG_INSN = OPTION_START,
  OPTION_DEBUG_FILE,
  OPTION_DO_COMMAND,
  OPTION_ARCHITECTURE,
  OPTION_TARGET,
  OPTION_ARCHITECTURE_INFO,
  OPTION_ENVIRONMENT,
  OPTION_ALIGNMENT,
  OPTION_VERBOSE,
  OPTION_ENDIAN,
  OPTION_DEBUG,
  OPTION_HELP,
  OPTION_VERSION,
  OPTION_LOAD_LMA,
  OPTION_LOAD_VMA,
  OPTION_SYSROOT
} STANDARD_OPTIONS;

static const OPTION standard_options[] =
{
  { {"verbose", no_argument, NULL, OPTION_VERBOSE},
      'v', NULL, "Verbose output",
      standard_option_handler, NULL },

  { {"endian", required_argument, NULL, OPTION_ENDIAN},
      'E', "big|little", "Set endianness",
      standard_option_handler, NULL },

  /* This option isn't supported unless all choices are supported in keeping
     with the goal of not printing in --help output things the simulator can't
     do [as opposed to things that just haven't been configured in].  */
  { {"environment", required_argument, NULL, OPTION_ENVIRONMENT},
      '\0', "user|virtual|operating", "Set running environment",
      standard_option_handler },

  { {"alignment", required_argument, NULL, OPTION_ALIGNMENT},
      '\0', "strict|nonstrict|forced", "Set memory access alignment",
      standard_option_handler },

  { {"debug", no_argument, NULL, OPTION_DEBUG},
      'D', NULL, "Print debugging messages",
      standard_option_handler },
  { {"debug-insn", no_argument, NULL, OPTION_DEBUG_INSN},
      '\0', NULL, "Print instruction debugging messages",
      standard_option_handler },
  { {"debug-file", required_argument, NULL, OPTION_DEBUG_FILE},
      '\0', "FILE NAME", "Specify debugging output file",
      standard_option_handler },

  { {"do-command", required_argument, NULL, OPTION_DO_COMMAND},
      '\0', "COMMAND", ""/*undocumented*/,
      standard_option_handler },

  { {"help", no_argument, NULL, OPTION_HELP},
      'H', NULL, "Print help information",
      standard_option_handler },
  { {"version", no_argument, NULL, OPTION_VERSION},
      '\0', NULL, "Print version information",
      standard_option_handler },

  { {"architecture", required_argument, NULL, OPTION_ARCHITECTURE},
      '\0', "MACHINE", "Specify the architecture to use",
      standard_option_handler },
  { {"architecture-info", no_argument, NULL, OPTION_ARCHITECTURE_INFO},
      '\0', NULL, "List supported architectures",
      standard_option_handler },
  { {"info-architecture", no_argument, NULL, OPTION_ARCHITECTURE_INFO},
      '\0', NULL, NULL,
      standard_option_handler },

  { {"target", required_argument, NULL, OPTION_TARGET},
      '\0', "BFDNAME", "Specify the object-code format for the object files",
      standard_option_handler },

  { {"load-lma", no_argument, NULL, OPTION_LOAD_LMA},
      '\0', NULL,
    "Use VMA or LMA addresses when loading image (default LMA)",
      standard_option_handler, "load-{lma,vma}" },
  { {"load-vma", no_argument, NULL, OPTION_LOAD_VMA},
      '\0', NULL, "", standard_option_handler,  "" },

  { {"sysroot", required_argument, NULL, OPTION_SYSROOT},
      '\0', "SYSROOT",
    "Root for system calls with absolute file-names and cwd at start",
      standard_option_handler, NULL },

  { {NULL, no_argument, NULL, 0}, '\0', NULL, NULL, NULL, NULL }
};

static SIM_RC
standard_option_handler (SIM_DESC sd, sim_cpu *cpu, int opt,
                         char *arg, int is_command)
{
  int i,n;

  switch ((STANDARD_OPTIONS) opt)
    {
    case OPTION_VERBOSE:
      STATE_VERBOSE_P (sd) = 1;
      break;

    case OPTION_ENDIAN:
      if (strcmp (arg, "big") == 0)
        {
          if (WITH_TARGET_BYTE_ORDER == BFD_ENDIAN_LITTLE)
            {
              sim_io_eprintf (sd, "Simulator compiled for little endian only.\n");
              return SIM_RC_FAIL;
            }
          /* FIXME:wip: Need to set something in STATE_CONFIG.  */
          current_target_byte_order = BFD_ENDIAN_BIG;
        }
      else if (strcmp (arg, "little") == 0)
        {
          if (WITH_TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
            {
              sim_io_eprintf (sd, "Simulator compiled for big endian only.\n");
              return SIM_RC_FAIL;
            }
          /* FIXME:wip: Need to set something in STATE_CONFIG.  */
          current_target_byte_order = BFD_ENDIAN_LITTLE;
        }
      else
        {
          sim_io_eprintf (sd, "Invalid endian specification `%s'\n", arg);
          return SIM_RC_FAIL;
        }
      break;

    case OPTION_ENVIRONMENT:
      if (strcmp (arg, "user") == 0)
        STATE_ENVIRONMENT (sd) = USER_ENVIRONMENT;
      else if (strcmp (arg, "virtual") == 0)
        STATE_ENVIRONMENT (sd) = VIRTUAL_ENVIRONMENT;
      else if (strcmp (arg, "operating") == 0)
        STATE_ENVIRONMENT (sd) = OPERATING_ENVIRONMENT;
      else
        {
          sim_io_eprintf (sd, "Invalid environment specification `%s'\n", arg);
          return SIM_RC_FAIL;
        }
      if (WITH_ENVIRONMENT != ALL_ENVIRONMENT
          && WITH_ENVIRONMENT != STATE_ENVIRONMENT (sd))
        {
          const char *type;
          switch (WITH_ENVIRONMENT)
            {
            case USER_ENVIRONMENT: type = "user"; break;
            case VIRTUAL_ENVIRONMENT: type = "virtual"; break;
            case OPERATING_ENVIRONMENT: type = "operating"; break;
            }
          sim_io_eprintf (sd, "Simulator compiled for the %s environment only.\n",
                          type);
          return SIM_RC_FAIL;
        }
      break;

    case OPTION_ALIGNMENT:
      if (strcmp (arg, "strict") == 0)
        {
          if (WITH_ALIGNMENT == 0 || WITH_ALIGNMENT == STRICT_ALIGNMENT)
            {
              current_alignment = STRICT_ALIGNMENT;
              break;
            }
        }
      else if (strcmp (arg, "nonstrict") == 0)
        {
          if (WITH_ALIGNMENT == 0 || WITH_ALIGNMENT == NONSTRICT_ALIGNMENT)
            {
              current_alignment = NONSTRICT_ALIGNMENT;
              break;
            }
        }
      else if (strcmp (arg, "forced") == 0)
        {
          if (WITH_ALIGNMENT == 0 || WITH_ALIGNMENT == FORCED_ALIGNMENT)
            {
              current_alignment = FORCED_ALIGNMENT;
              break;
            }
        }
      else
        {
          sim_io_eprintf (sd, "Invalid alignment specification `%s'\n", arg);
          return SIM_RC_FAIL;
        }
      switch (WITH_ALIGNMENT)
        {
        case STRICT_ALIGNMENT:
          sim_io_eprintf (sd, "Simulator compiled for strict alignment only.\n");
          break;
        case NONSTRICT_ALIGNMENT:
          sim_io_eprintf (sd, "Simulator compiled for nonstrict alignment only.\n");
          break;
        case FORCED_ALIGNMENT:
          sim_io_eprintf (sd, "Simulator compiled for forced alignment only.\n");
          break;
        }
      return SIM_RC_FAIL;

    case OPTION_DEBUG:
      if (! WITH_DEBUG)
        sim_io_eprintf (sd, "Debugging not compiled in, `-D' ignored\n");
      else
        {
          for (n = 0; n < MAX_NR_PROCESSORS; ++n)
            for (i = 0; i < MAX_DEBUG_VALUES; ++i)
              CPU_DEBUG_FLAGS (STATE_CPU (sd, n))[i] = 1;
        }
      break;

    case OPTION_DEBUG_INSN :
      if (! WITH_DEBUG)
        sim_io_eprintf (sd, "Debugging not compiled in, `--debug-insn' ignored\n");
      else
        {
          for (n = 0; n < MAX_NR_PROCESSORS; ++n)
            CPU_DEBUG_FLAGS (STATE_CPU (sd, n))[DEBUG_INSN_IDX] = 1;
        }
      break;

    case OPTION_DEBUG_FILE :
      if (! WITH_DEBUG)
        sim_io_eprintf (sd, "Debugging not compiled in, `--debug-file' ignored\n");
      else
        {
          FILE *f = fopen (arg, "w");

          if (f == NULL)
            {
              sim_io_eprintf (sd, "Unable to open debug output file `%s'\n", arg);
              return SIM_RC_FAIL;
            }
          for (n = 0; n < MAX_NR_PROCESSORS; ++n)
            CPU_DEBUG_FILE (STATE_CPU (sd, n)) = f;
        }
      break;

    case OPTION_DO_COMMAND:
      sim_do_command (sd, arg);
      break;

    case OPTION_ARCHITECTURE:
      {
        const struct bfd_arch_info *ap = bfd_scan_arch (arg);
        if (ap == NULL)
          {
            sim_io_eprintf (sd, "Architecture `%s' unknown\n", arg);
            return SIM_RC_FAIL;
          }
        STATE_ARCHITECTURE (sd) = ap;
        break;
      }

    case OPTION_ARCHITECTURE_INFO:
      {
        const char **list = bfd_arch_list ();
        const char **lp;
        if (list == NULL)
          abort ();
        sim_io_printf (sd, "Possible architectures:");
        for (lp = list; *lp != NULL; lp++)
          sim_io_printf (sd, " %s", *lp);
        sim_io_printf (sd, "\n");
        free (list);
        break;
      }

    case OPTION_TARGET:
      {
        STATE_TARGET (sd) = xstrdup (arg);
        break;
      }

    case OPTION_LOAD_LMA:
      {
        STATE_LOAD_AT_LMA_P (sd) = 1;
        break;
      }

    case OPTION_LOAD_VMA:
      {
        STATE_LOAD_AT_LMA_P (sd) = 0;
        break;
      }

    case OPTION_HELP:
      sim_print_help (sd, is_command);
      if (STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
        exit (0);
      /* FIXME: 'twould be nice to do something similar if gdb.  */
      break;

    case OPTION_VERSION:
      sim_io_printf (sd, "GNU simulator %s%s\n", PKGVERSION, version);
      if (STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
        exit (0);
      break;

    case OPTION_SYSROOT:
      /* Don't leak memory in the odd event that there's lots of
         --sysroot=... options.  We treat "" specially since this
         is the statically initialized value and cannot free it.  */
      if (simulator_sysroot[0] != '\0')
        free (simulator_sysroot);
      if (arg[0] != '\0')
        simulator_sysroot = xstrdup (arg);
      else
        simulator_sysroot = "";
      break;
    }

  return SIM_RC_OK;
}

/* Add the standard option list to the simulator.  */

SIM_RC
standard_install (SIM_DESC sd)
{
  SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
  if (sim_add_option_table (sd, NULL, standard_options) != SIM_RC_OK)
    return SIM_RC_FAIL;
  STATE_LOAD_AT_LMA_P (sd) = 1;
  return SIM_RC_OK;
}

/* Return non-zero if arg is a duplicate argument.
   If ARG is NULL, initialize.  */

#define ARG_HASH_SIZE 97
#define ARG_HASH(a) ((256 * (unsigned char) a[0] + (unsigned char) a[1]) % ARG_HASH_SIZE)

static int
dup_arg_p (const char *arg)
{
  int hash;
  static const char **arg_table = NULL;

  if (arg == NULL)
    {
      if (arg_table == NULL)
        arg_table = (const char **) xmalloc (ARG_HASH_SIZE * sizeof (char *));
      memset (arg_table, 0, ARG_HASH_SIZE * sizeof (char *));
      return 0;
    }

  hash = ARG_HASH (arg);
  while (arg_table[hash] != NULL)
    {
      if (strcmp (arg, arg_table[hash]) == 0)
        return 1;
      /* We assume there won't be more than ARG_HASH_SIZE arguments so we
         don't check if the table is full.  */
      if (++hash == ARG_HASH_SIZE)
        hash = 0;
    }
  arg_table[hash] = arg;
  return 0;
}

/* Called by sim_open to parse the arguments.  */

SIM_RC
sim_parse_args (SIM_DESC sd, char * const *argv)
{
  int c, i, argc, num_opts, save_opterr;
  char *p, *short_options;
  /* The `val' option struct entry is dynamically assigned for options that
     only come in the long form.  ORIG_VAL is used to get the original value
     back.  */
  int *orig_val;
  struct option *lp, *long_options;
  const struct option_list *ol;
  const OPTION *opt;
  OPTION_HANDLER **handlers;
  sim_cpu **opt_cpu;
  SIM_RC result = SIM_RC_OK;

  /* Count the number of arguments.  */
  argc = countargv (argv);

  /* Count the number of options.  */
  num_opts = 0;
  for (ol = STATE_OPTIONS (sd); ol != NULL; ol = ol->next)
    for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
      ++num_opts;
  for (i = 0; i < MAX_NR_PROCESSORS; ++i)
    for (ol = CPU_OPTIONS (STATE_CPU (sd, i)); ol != NULL; ol = ol->next)
      for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
        ++num_opts;

  /* Initialize duplicate argument checker.  */
  (void) dup_arg_p (NULL);

  /* Build the option table for getopt.  */

  long_options = NZALLOC (struct option, num_opts + 1);
  lp = long_options;
  short_options = NZALLOC (char, num_opts * 3 + 1);
  p = short_options;
  handlers = NZALLOC (OPTION_HANDLER *, OPTION_START + num_opts);
  orig_val = NZALLOC (int, OPTION_START + num_opts);
  opt_cpu = NZALLOC (sim_cpu *, OPTION_START + num_opts);

  /* Set '+' as first char so argument permutation isn't done.  This
     is done to stop getopt_long returning options that appear after
     the target program.  Such options should be passed unchanged into
     the program image. */
  *p++ = '+';

  for (i = OPTION_START, ol = STATE_OPTIONS (sd); ol != NULL; ol = ol->next)
    for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
      {
        if (dup_arg_p (opt->opt.name))
          continue;
        if (opt->shortopt != 0)
          {
            *p++ = opt->shortopt;
            if (opt->opt.has_arg == required_argument)
              *p++ = ':';
            else if (opt->opt.has_arg == optional_argument)
              { *p++ = ':'; *p++ = ':'; }
            handlers[(unsigned char) opt->shortopt] = opt->handler;
            if (opt->opt.val != 0)
              orig_val[(unsigned char) opt->shortopt] = opt->opt.val;
            else
              orig_val[(unsigned char) opt->shortopt] = opt->shortopt;
          }
        if (opt->opt.name != NULL)
          {
            *lp = opt->opt;
            /* Dynamically assign `val' numbers for long options. */
            lp->val = i++;
            handlers[lp->val] = opt->handler;
            orig_val[lp->val] = opt->opt.val;
            opt_cpu[lp->val] = NULL;
            ++lp;
          }
      }

  for (c = 0; c < MAX_NR_PROCESSORS; ++c)
    {
      sim_cpu *cpu = STATE_CPU (sd, c);
      for (ol = CPU_OPTIONS (cpu); ol != NULL; ol = ol->next)
        for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
          {
#if 0 /* Each option is prepended with --<cpuname>- so this greatly cuts down
         on the need for dup_arg_p checking.  Maybe in the future it'll be
         needed so this is just commented out, and not deleted.  */
            if (dup_arg_p (opt->opt.name))
              continue;
#endif
            /* Don't allow short versions of cpu specific options for now.  */
            if (opt->shortopt != 0)
              {
                sim_io_eprintf (sd, "internal error, short cpu specific option");
                result = SIM_RC_FAIL;
                break;
              }
            if (opt->opt.name != NULL)
              {
                char *name;
                *lp = opt->opt;
                /* Prepend --<cpuname>- to the option.  */
                if (asprintf (&name, "%s-%s", CPU_NAME (cpu), lp->name) < 0)
                  {
                    sim_io_eprintf (sd, "internal error, out of memory");
                    result = SIM_RC_FAIL;
                    break;
                  }
                lp->name = name;
                /* Dynamically assign `val' numbers for long options. */
                lp->val = i++;
                handlers[lp->val] = opt->handler;
                orig_val[lp->val] = opt->opt.val;
                opt_cpu[lp->val] = cpu;
                ++lp;
              }
          }
    }

  /* Terminate the short and long option lists.  */
  *p = 0;
  lp->name = NULL;

  /* Ensure getopt is initialized.  */
  optind = 0;

  /* Do not lot getopt throw errors for us.  But don't mess with the state for
     any callers higher up by saving/restoring it.  */
  save_opterr = opterr;
  opterr = 0;

  while (1)
    {
      int longind, optc;

      optc = getopt_long (argc, argv, short_options, long_options, &longind);
      if (optc == -1)
        {
          if (STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
            STATE_PROG_ARGV (sd) = dupargv (argv + optind);
          break;
        }
      if (optc == '?')
        {
          /* If getopt rejects a short option, optopt is set to the bad char.
             If it rejects a long option, we have to look at optind.  In the
             short option case, argv could be multiple short options.  */
          const char *badopt;
          char optbuf[3];

          if (optopt)
            {
              sprintf (optbuf, "-%c", optopt);
              badopt = optbuf;
            }
          else
            badopt = argv[optind - 1];

          sim_io_eprintf (sd,
                          "%s: unrecognized option '%s'\n"
                          "Use --help for a complete list of options.\n",
                          STATE_MY_NAME (sd), badopt);

          result = SIM_RC_FAIL;
          break;
        }

      if ((*handlers[optc]) (sd, opt_cpu[optc], orig_val[optc], optarg, 0/*!is_command*/) == SIM_RC_FAIL)
        {
          result = SIM_RC_FAIL;
          break;
        }
    }

  opterr = save_opterr;

  free (long_options);
  free (short_options);
  free (handlers);
  free (opt_cpu);
  free (orig_val);
  return result;
}

/* Utility of sim_print_help to print a list of option tables.  */

static void
print_help (SIM_DESC sd, sim_cpu *cpu, const struct option_list *ol, int is_command)
{
  const OPTION *opt;

  for ( ; ol != NULL; ol = ol->next)
    for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
      {
        const int indent = 30;
        int comma, len;
        const OPTION *o;

        if (dup_arg_p (opt->opt.name))
          continue;

        if (opt->doc == NULL)
          continue;

        if (opt->doc_name != NULL && opt->doc_name [0] == '\0')
          continue;

        sim_io_printf (sd, "  ");

        comma = 0;
        len = 2;

        /* list any short options (aliases) for the current OPT */
        if (!is_command)
          {
            o = opt;
            do
              {
                if (o->shortopt != '\0')
                  {
                    sim_io_printf (sd, "%s-%c", comma ? ", " : "", o->shortopt);
                    len += (comma ? 2 : 0) + 2;
                    if (o->arg != NULL)
                      {
                        if (o->opt.has_arg == optional_argument)
                          {
                            sim_io_printf (sd, "[%s]", o->arg);
                            len += 1 + strlen (o->arg) + 1;
                          }
                        else
                          {
                            sim_io_printf (sd, " %s", o->arg);
                            len += 1 + strlen (o->arg);
                          }
                      }
                    comma = 1;
                  }
                ++o;
              }
            while (OPTION_VALID_P (o) && o->doc == NULL);
          }

        /* list any long options (aliases) for the current OPT */
        o = opt;
        do
          {
            const char *name;
            const char *cpu_prefix = cpu ? CPU_NAME (cpu) : NULL;
            if (o->doc_name != NULL)
              name = o->doc_name;
            else
              name = o->opt.name;
            if (name != NULL)
              {
                sim_io_printf (sd, "%s%s%s%s%s",
                               comma ? ", " : "",
                               is_command ? "" : "--",
                               cpu ? cpu_prefix : "",
                               cpu ? "-" : "",
                               name);
                len += ((comma ? 2 : 0)
                        + (is_command ? 0 : 2)
                        + strlen (name));
                if (o->arg != NULL)
                  {
                    if (o->opt.has_arg == optional_argument)
                      {
                        sim_io_printf (sd, "[=%s]", o->arg);
                        len += 2 + strlen (o->arg) + 1;
                      }
                    else
                      {
                        sim_io_printf (sd, " %s", o->arg);
                        len += 1 + strlen (o->arg);
                      }
                  }
                comma = 1;
              }
            ++o;
          }
        while (OPTION_VALID_P (o) && o->doc == NULL);

        if (len >= indent)
          {
            sim_io_printf (sd, "\n%*s", indent, "");
          }
        else
          sim_io_printf (sd, "%*s", indent - len, "");

        /* print the description, word wrap long lines */
        {
          const char *chp = opt->doc;
          unsigned doc_width = 80 - indent;
          while (strlen (chp) >= doc_width) /* some slack */
            {
              const char *end = chp + doc_width - 1;
              while (end > chp && !isspace (*end))
                end --;
              if (end == chp)
                end = chp + doc_width - 1;
              /* The cast should be ok - its distances between to
                 points in a string.  */
              sim_io_printf (sd, "%.*s\n%*s", (int) (end - chp), chp, indent,
                             "");
              chp = end;
              while (isspace (*chp) && *chp != '\0')
                chp++;
            }
          sim_io_printf (sd, "%s\n", chp);
        }
      }
}

/* Print help messages for the options.  */

void
sim_print_help (SIM_DESC sd, int is_command)
{
  if (STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
    sim_io_printf (sd, "Usage: %s [options] program [program args]\n",
                   STATE_MY_NAME (sd));

  /* Initialize duplicate argument checker.  */
  (void) dup_arg_p (NULL);

  if (STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
    sim_io_printf (sd, "Options:\n");
  else
    sim_io_printf (sd, "Commands:\n");

  print_help (sd, NULL, STATE_OPTIONS (sd), is_command);
  sim_io_printf (sd, "\n");

  /* Print cpu-specific options.  */
  {
    int i;

    for (i = 0; i < MAX_NR_PROCESSORS; ++i)
      {
        sim_cpu *cpu = STATE_CPU (sd, i);
        if (CPU_OPTIONS (cpu) == NULL)
          continue;
        sim_io_printf (sd, "CPU %s specific options:\n", CPU_NAME (cpu));
        print_help (sd, cpu, CPU_OPTIONS (cpu), is_command);
        sim_io_printf (sd, "\n");
      }
  }

  sim_io_printf (sd, "Note: Depending on the simulator configuration some %ss\n",
                 STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE ? "option" : "command");
  sim_io_printf (sd, "      may not be applicable\n");

  if (STATE_OPEN_KIND (sd) == SIM_OPEN_STANDALONE)
    {
      sim_io_printf (sd, "\n");
      sim_io_printf (sd, "program args    Arguments to pass to simulated program.\n");
      sim_io_printf (sd, "                Note: Very few simulators support this.\n");
    }
}

/* Utility of sim_args_command to find the closest match for a command.
   Commands that have "-" in them can be specified as separate words.
   e.g. sim memory-region 0x800000,0x4000
   or   sim memory region 0x800000,0x4000
   If CPU is non-null, use its option table list, otherwise use the main one.
   *PARGI is where to start looking in ARGV.  It is updated to point past
   the found option.  */

static const OPTION *
find_match (SIM_DESC sd, sim_cpu *cpu, char *argv[], int *pargi)
{
  const struct option_list *ol;
  const OPTION *opt;
  /* most recent option match */
  const OPTION *matching_opt = NULL;
  int matching_argi = -1;

  if (cpu)
    ol = CPU_OPTIONS (cpu);
  else
    ol = STATE_OPTIONS (sd);

  /* Skip passed elements specified by *PARGI.  */
  argv += *pargi;

  for ( ; ol != NULL; ol = ol->next)
    for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
      {
        int argi = 0;
        const char *name = opt->opt.name;
        if (name == NULL)
          continue;
        while (argv [argi] != NULL
               && strncmp (name, argv [argi], strlen (argv [argi])) == 0)
          {
            name = &name [strlen (argv[argi])];
            if (name [0] == '-')
              {
                /* leading match ...<a-b-c>-d-e-f - continue search */
                name ++; /* skip `-' */
                argi ++;
                continue;
              }
            else if (name [0] == '\0')
              {
                /* exact match ...<a-b-c-d-e-f> - better than before? */
                if (argi > matching_argi)
                  {
                    matching_argi = argi;
                    matching_opt = opt;
                  }
                break;
              }
            else
              break;
          }
      }

  *pargi = matching_argi;
  return matching_opt;
}

static char **
complete_option_list (char **ret, size_t *cnt, const struct option_list *ol,
                      const char *text, const char *word)
{
  const OPTION *opt = NULL;
  int argi;
  size_t len = strlen (word);

  for ( ; ol != NULL; ol = ol->next)
    for (opt = ol->options; OPTION_VALID_P (opt); ++opt)
      {
        const char *name = opt->opt.name;

        /* A long option to match against?  */
        if (!name)
          continue;

        /* Does this option actually match?  */
        if (strncmp (name, word, len))
          continue;

        ret = xrealloc (ret, ++*cnt * sizeof (ret[0]));
        ret[*cnt - 2] = xstrdup (name);
      }

  return ret;
}

/* All leading text is stored in @text, while the current word being
   completed is stored in @word.  Trailing text of @word is not.  */

char **
sim_complete_command (SIM_DESC sd, const char *text, const char *word)
{
  char **ret = NULL;
  size_t cnt = 1;
  sim_cpu *cpu;

  /* Only complete first word for now.  */
  if (text != word)
    return ret;

  cpu = STATE_CPU (sd, 0);
  if (cpu)
    ret = complete_option_list (ret, &cnt, CPU_OPTIONS (cpu), text, word);
  ret = complete_option_list (ret, &cnt, STATE_OPTIONS (sd), text, word);

  if (ret)
    ret[cnt - 1] = NULL;
  return ret;
}

SIM_RC
sim_args_command (SIM_DESC sd, const char *cmd)
{
  /* something to do? */
  if (cmd == NULL)
    return SIM_RC_OK; /* FIXME - perhaps help would be better */

  if (cmd [0] == '-')
    {
      /* user specified -<opt> ... form? */
      char **argv = buildargv (cmd);
      SIM_RC rc = sim_parse_args (sd, argv);
      freeargv (argv);
      return rc;
    }
  else
    {
      char **argv = buildargv (cmd);
      const OPTION *matching_opt = NULL;
      int matching_argi;
      sim_cpu *cpu;

      if (argv [0] == NULL)
        {
          freeargv (argv);
          return SIM_RC_OK; /* FIXME - perhaps help would be better */
        }

      /* First check for a cpu selector.  */
      {
        char *cpu_name = xstrdup (argv[0]);
        char *hyphen = strchr (cpu_name, '-');
        if (hyphen)
          *hyphen = 0;
        cpu = sim_cpu_lookup (sd, cpu_name);
        if (cpu)
          {
            /* If <cpuname>-<command>, point argv[0] at <command>.  */
            if (hyphen)
              {
                matching_argi = 0;
                argv[0] += hyphen - cpu_name + 1;
              }
            else
              matching_argi = 1;
            matching_opt = find_match (sd, cpu, argv, &matching_argi);
            /* If hyphen found restore argv[0].  */
            if (hyphen)
              argv[0] -= hyphen - cpu_name + 1;
          }
        free (cpu_name);
      }

      /* If that failed, try the main table.  */
      if (matching_opt == NULL)
        {
          matching_argi = 0;
          matching_opt = find_match (sd, NULL, argv, &matching_argi);
        }

      if (matching_opt != NULL)
        {
          switch (matching_opt->opt.has_arg)
            {
            case no_argument:
              if (argv [matching_argi + 1] == NULL)
                matching_opt->handler (sd, cpu, matching_opt->opt.val,
                                       NULL, 1/*is_command*/);
              else
                sim_io_eprintf (sd, "Command `%s' takes no arguments\n",
                                matching_opt->opt.name);
              break;
            case optional_argument:
              if (argv [matching_argi + 1] == NULL)
                matching_opt->handler (sd, cpu, matching_opt->opt.val,
                                       NULL, 1/*is_command*/);
              else if (argv [matching_argi + 2] == NULL)
                matching_opt->handler (sd, cpu, matching_opt->opt.val,
                                       argv [matching_argi + 1], 1/*is_command*/);
              else
                sim_io_eprintf (sd, "Command `%s' requires no more than one argument\n",
                                matching_opt->opt.name);
              break;
            case required_argument:
              if (argv [matching_argi + 1] == NULL)
                sim_io_eprintf (sd, "Command `%s' requires an argument\n",
                                matching_opt->opt.name);
              else if (argv [matching_argi + 2] == NULL)
                matching_opt->handler (sd, cpu, matching_opt->opt.val,
                                       argv [matching_argi + 1], 1/*is_command*/);
              else
                sim_io_eprintf (sd, "Command `%s' requires only one argument\n",
                                matching_opt->opt.name);
            }
          freeargv (argv);
          return SIM_RC_OK;
        }

      freeargv (argv);
    }

  /* didn't find anything that remotly matched */
  return SIM_RC_FAIL;
}