xref: /freebsd-10-stable/contrib/gdb/gdb/main.c

/* Top level stuff for GDB, the GNU debugger.

   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
   1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software
   Foundation, Inc.

   This file is part of GDB.

   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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "top.h"
#include "target.h"
#include "inferior.h"
#include "symfile.h"
#include "gdbcore.h"

#include "getopt.h"

#include <sys/types.h>
#include "gdb_stat.h"
#include <ctype.h>

#include "gdb_string.h"
#include "event-loop.h"
#include "ui-out.h"

#include "interps.h"
#include "main.h"

/* If nonzero, display time usage both at startup and for each command.  */

int display_time;

/* If nonzero, display space usage both at startup and for each command.  */

int display_space;

/* Whether this is the async version or not.  The async version is
   invoked on the command line with the -nw --async options.  In this
   version, the usual command_loop is substituted by and event loop which
   processes UI events asynchronously. */
int event_loop_p = 1;

/* The selected interpreter.  This will be used as a set command
   variable, so it should always be malloc'ed - since
   do_setshow_command will free it. */
char *interpreter_p;

/* Whether xdb commands will be handled */
int xdb_commands = 0;

/* Whether dbx commands will be handled */
int dbx_commands = 0;

/* System root path, used to find libraries etc.  */
char *gdb_sysroot = 0;

struct ui_file *gdb_stdout;
struct ui_file *gdb_stderr;
struct ui_file *gdb_stdlog;
struct ui_file *gdb_stdin;
/* target IO streams */
struct ui_file *gdb_stdtargin;
struct ui_file *gdb_stdtarg;
struct ui_file *gdb_stdtargerr;

/* Whether to enable writing into executable and core files */
extern int write_files;

static void print_gdb_help (struct ui_file *);

/* These two are used to set the external editor commands when gdb is farming
   out files to be edited by another program. */

extern char *external_editor_command;

/* Call command_loop.  If it happens to return, pass that through as a
   non-zero return status. */

static int
captured_command_loop (void *data)
{
  current_interp_command_loop ();
  /* FIXME: cagney/1999-11-05: A correct command_loop() implementaton
     would clean things up (restoring the cleanup chain) to the state
     they were just prior to the call.  Technically, this means that
     the do_cleanups() below is redundant.  Unfortunately, many FUNCs
     are not that well behaved.  do_cleanups should either be replaced
     with a do_cleanups call (to cover the problem) or an assertion
     check to detect bad FUNCs code. */
  do_cleanups (ALL_CLEANUPS);
  /* If the command_loop returned, normally (rather than threw an
     error) we try to quit. If the quit is aborted, catch_errors()
     which called this catch the signal and restart the command
     loop. */
  quit_command (NULL, instream == stdin);
  return 1;
}

static int
captured_main (void *data)
{
  struct captured_main_args *context = data;
  int argc = context->argc;
  char **argv = context->argv;
  int count;
  static int quiet = 0;
  static int batch = 0;
  static int set_args = 0;

  /* Pointers to various arguments from command line.  */
  char *symarg = NULL;
  char *execarg = NULL;
  char *corearg = NULL;
  char *cdarg = NULL;
  char *ttyarg = NULL;

  /* These are static so that we can take their address in an initializer.  */
  static int print_help;
  static int print_version;

  /* Pointers to all arguments of --command option.  */
  char **cmdarg;
  /* Allocated size of cmdarg.  */
  int cmdsize;
  /* Number of elements of cmdarg used.  */
  int ncmd;

  /* Indices of all arguments of --directory option.  */
  char **dirarg;
  /* Allocated size.  */
  int dirsize;
  /* Number of elements used.  */
  int ndir;

  struct stat homebuf, cwdbuf;
  char *homedir, *homeinit;

  int i;

  long time_at_startup = get_run_time ();

#if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
  setlocale (LC_MESSAGES, "");
#endif
#if defined (HAVE_SETLOCALE)
  setlocale (LC_CTYPE, "");
#endif
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  /* This needs to happen before the first use of malloc.  */
  init_malloc (NULL);

#ifdef HAVE_SBRK
  lim_at_start = (char *) sbrk (0);
#endif

#if defined (ALIGN_STACK_ON_STARTUP)
  i = (int) &count & 0x3;
  if (i != 0)
    alloca (4 - i);
#endif

  cmdsize = 1;
  cmdarg = (char **) xmalloc (cmdsize * sizeof (*cmdarg));
  ncmd = 0;
  dirsize = 1;
  dirarg = (char **) xmalloc (dirsize * sizeof (*dirarg));
  ndir = 0;

  quit_flag = 0;
  line = (char *) xmalloc (linesize);
  line[0] = '\0';		/* Terminate saved (now empty) cmd line */
  instream = stdin;

  getcwd (gdb_dirbuf, sizeof (gdb_dirbuf));
  current_directory = gdb_dirbuf;

  gdb_stdout = stdio_fileopen (stdout);
  gdb_stderr = stdio_fileopen (stderr);
  gdb_stdlog = gdb_stderr;	/* for moment */
  gdb_stdtarg = gdb_stderr;	/* for moment */
  gdb_stdin = stdio_fileopen (stdin);
  gdb_stdtargerr = gdb_stderr;	/* for moment */
  gdb_stdtargin = gdb_stdin;	/* for moment */

  /* initialize error() */
  error_init ();

  /* Set the sysroot path.  */
#ifdef TARGET_SYSTEM_ROOT_RELOCATABLE
  gdb_sysroot = make_relative_prefix (argv[0], BINDIR, TARGET_SYSTEM_ROOT);
  if (gdb_sysroot)
    {
      struct stat s;
      int res = 0;

      if (stat (gdb_sysroot, &s) == 0)
	if (S_ISDIR (s.st_mode))
	  res = 1;

      if (res == 0)
	{
	  xfree (gdb_sysroot);
	  gdb_sysroot = TARGET_SYSTEM_ROOT;
	}
    }
  else
    gdb_sysroot = TARGET_SYSTEM_ROOT;
#else
#if defined (TARGET_SYSTEM_ROOT)
  gdb_sysroot = TARGET_SYSTEM_ROOT;
#else
  gdb_sysroot = "";
#endif
#endif

  /* There will always be an interpreter.  Either the one passed into
     this captured main, or one specified by the user at start up, or
     the console.  Initialize the interpreter to the one requested by
     the application.  */
  interpreter_p = xstrdup (context->interpreter_p);

  /* Parse arguments and options.  */
  {
    int c;
    /* When var field is 0, use flag field to record the equivalent
       short option (or arbitrary numbers starting at 10 for those
       with no equivalent).  */
    enum {
      OPT_SE = 10,
      OPT_CD,
      OPT_ANNOTATE,
      OPT_STATISTICS,
      OPT_TUI,
      OPT_NOWINDOWS,
      OPT_WINDOWS
    };
    static struct option long_options[] =
    {
      {"async", no_argument, &event_loop_p, 1},
      {"noasync", no_argument, &event_loop_p, 0},
#if defined(TUI)
      {"tui", no_argument, 0, OPT_TUI},
#endif
      {"xdb", no_argument, &xdb_commands, 1},
      {"dbx", no_argument, &dbx_commands, 1},
      {"readnow", no_argument, &readnow_symbol_files, 1},
      {"r", no_argument, &readnow_symbol_files, 1},
      {"quiet", no_argument, &quiet, 1},
      {"q", no_argument, &quiet, 1},
      {"silent", no_argument, &quiet, 1},
      {"nx", no_argument, &inhibit_gdbinit, 1},
      {"n", no_argument, &inhibit_gdbinit, 1},
      {"batch", no_argument, &batch, 1},
      {"epoch", no_argument, &epoch_interface, 1},

    /* This is a synonym for "--annotate=1".  --annotate is now preferred,
       but keep this here for a long time because people will be running
       emacses which use --fullname.  */
      {"fullname", no_argument, 0, 'f'},
      {"f", no_argument, 0, 'f'},

      {"annotate", required_argument, 0, OPT_ANNOTATE},
      {"help", no_argument, &print_help, 1},
      {"se", required_argument, 0, OPT_SE},
      {"symbols", required_argument, 0, 's'},
      {"s", required_argument, 0, 's'},
      {"exec", required_argument, 0, 'e'},
      {"e", required_argument, 0, 'e'},
      {"core", required_argument, 0, 'c'},
      {"c", required_argument, 0, 'c'},
      {"pid", required_argument, 0, 'p'},
      {"p", required_argument, 0, 'p'},
      {"command", required_argument, 0, 'x'},
      {"version", no_argument, &print_version, 1},
      {"x", required_argument, 0, 'x'},
#ifdef GDBTK
      {"tclcommand", required_argument, 0, 'z'},
      {"enable-external-editor", no_argument, 0, 'y'},
      {"editor-command", required_argument, 0, 'w'},
#endif
      {"ui", required_argument, 0, 'i'},
      {"interpreter", required_argument, 0, 'i'},
      {"i", required_argument, 0, 'i'},
      {"directory", required_argument, 0, 'd'},
      {"d", required_argument, 0, 'd'},
      {"cd", required_argument, 0, OPT_CD},
      {"tty", required_argument, 0, 't'},
      {"baud", required_argument, 0, 'b'},
      {"b", required_argument, 0, 'b'},
      {"nw", no_argument, NULL, OPT_NOWINDOWS},
      {"nowindows", no_argument, NULL, OPT_NOWINDOWS},
      {"w", no_argument, NULL, OPT_WINDOWS},
      {"windows", no_argument, NULL, OPT_WINDOWS},
      {"statistics", no_argument, 0, OPT_STATISTICS},
      {"write", no_argument, &write_files, 1},
      {"args", no_argument, &set_args, 1},
      {0, no_argument, 0, 0}
    };

    while (1)
      {
	int option_index;

	c = getopt_long_only (argc, argv, "",
			      long_options, &option_index);
	if (c == EOF || set_args)
	  break;

	/* Long option that takes an argument.  */
	if (c == 0 && long_options[option_index].flag == 0)
	  c = long_options[option_index].val;

	switch (c)
	  {
	  case 0:
	    /* Long option that just sets a flag.  */
	    break;
	  case OPT_SE:
	    symarg = optarg;
	    execarg = optarg;
	    break;
	  case OPT_CD:
	    cdarg = optarg;
	    break;
	  case OPT_ANNOTATE:
	    /* FIXME: what if the syntax is wrong (e.g. not digits)?  */
	    annotation_level = atoi (optarg);
	    break;
	  case OPT_STATISTICS:
	    /* Enable the display of both time and space usage.  */
	    display_time = 1;
	    display_space = 1;
	    break;
	  case OPT_TUI:
	    /* --tui is equivalent to -i=tui.  */
	    xfree (interpreter_p);
	    interpreter_p = xstrdup ("tui");
	    break;
	  case OPT_WINDOWS:
	    /* FIXME: cagney/2003-03-01: Not sure if this option is
               actually useful, and if it is, what it should do.  */
	    use_windows = 1;
	    break;
	  case OPT_NOWINDOWS:
	    /* -nw is equivalent to -i=console.  */
	    xfree (interpreter_p);
	    interpreter_p = xstrdup (INTERP_CONSOLE);
	    use_windows = 0;
	    break;
	  case 'f':
	    annotation_level = 1;
/* We have probably been invoked from emacs.  Disable window interface.  */
	    use_windows = 0;
	    break;
	  case 's':
	    symarg = optarg;
	    break;
	  case 'e':
	    execarg = optarg;
	    break;
	  case 'c':
	    corearg = optarg;
	    break;
	  case 'p':
	    /* "corearg" is shared by "--core" and "--pid" */
	    corearg = optarg;
	    break;
	  case 'x':
	    cmdarg[ncmd++] = optarg;
	    if (ncmd >= cmdsize)
	      {
		cmdsize *= 2;
		cmdarg = (char **) xrealloc ((char *) cmdarg,
					     cmdsize * sizeof (*cmdarg));
	      }
	    break;
#ifdef GDBTK
	  case 'z':
	    {
extern int gdbtk_test (char *);
	      if (!gdbtk_test (optarg))
		{
		  fprintf_unfiltered (gdb_stderr, _("%s: unable to load tclcommand file \"%s\""),
				      argv[0], optarg);
		  exit (1);
		}
	      break;
	    }
	  case 'y':
	    /* Backwards compatibility only.  */
	    break;
	  case 'w':
	    {
	      external_editor_command = xstrdup (optarg);
	      break;
	    }
#endif /* GDBTK */
	  case 'i':
	    xfree (interpreter_p);
	    interpreter_p = xstrdup (optarg);
	    break;
	  case 'd':
	    dirarg[ndir++] = optarg;
	    if (ndir >= dirsize)
	      {
		dirsize *= 2;
		dirarg = (char **) xrealloc ((char *) dirarg,
					     dirsize * sizeof (*dirarg));
	      }
	    break;
	  case 't':
	    ttyarg = optarg;
	    break;
	  case 'q':
	    quiet = 1;
	    break;
	  case 'b':
	    {
	      int i;
	      char *p;

	      i = strtol (optarg, &p, 0);
	      if (i == 0 && p == optarg)

		/* Don't use *_filtered or warning() (which relies on
		   current_target) until after initialize_all_files(). */

		fprintf_unfiltered
		  (gdb_stderr,
		   _("warning: could not set baud rate to `%s'.\n"), optarg);
	      else
		baud_rate = i;
	    }
            break;
	  case 'l':
	    {
	      int i;
	      char *p;

	      i = strtol (optarg, &p, 0);
	      if (i == 0 && p == optarg)

		/* Don't use *_filtered or warning() (which relies on
		   current_target) until after initialize_all_files(). */

		fprintf_unfiltered
		  (gdb_stderr,
		 _("warning: could not set timeout limit to `%s'.\n"), optarg);
	      else
		remote_timeout = i;
	    }
	    break;

	  case '?':
	    fprintf_unfiltered (gdb_stderr,
			_("Use `%s --help' for a complete list of options.\n"),
				argv[0]);
	    exit (1);
	  }
      }

    /* If --help or --version, disable window interface.  */
    if (print_help || print_version)
      {
	use_windows = 0;
      }

    if (set_args)
      {
	/* The remaining options are the command-line options for the
	   inferior.  The first one is the sym/exec file, and the rest
	   are arguments.  */
	if (optind >= argc)
	  {
	    fprintf_unfiltered (gdb_stderr,
				_("%s: `--args' specified but no program specified\n"),
				argv[0]);
	    exit (1);
	  }
	symarg = argv[optind];
	execarg = argv[optind];
	++optind;
	set_inferior_args_vector (argc - optind, &argv[optind]);
      }
    else
      {
	/* OK, that's all the options.  The other arguments are filenames.  */
	count = 0;
	for (; optind < argc; optind++)
	  switch (++count)
	    {
	    case 1:
	      symarg = argv[optind];
	      execarg = argv[optind];
	      break;
	    case 2:
	      /* The documentation says this can be a "ProcID" as well.
	         We will try it as both a corefile and a pid.  */
	      corearg = argv[optind];
	      break;
	    case 3:
	      fprintf_unfiltered (gdb_stderr,
				  _("Excess command line arguments ignored. (%s%s)\n"),
				  argv[optind], (optind == argc - 1) ? "" : " ...");
	      break;
	    }
      }
    if (batch)
      quiet = 1;
  }

  /* Initialize all files.  Give the interpreter a chance to take
     control of the console via the init_ui_hook()) */
  gdb_init (argv[0]);

  /* Do these (and anything which might call wrap_here or *_filtered)
     after initialize_all_files() but before the interpreter has been
     installed.  Otherwize the help/version messages will be eaten by
     the interpreter's output handler.  */

  if (print_version)
    {
      print_gdb_version (gdb_stdout);
      wrap_here ("");
      printf_filtered ("\n");
      exit (0);
    }

  if (print_help)
    {
      print_gdb_help (gdb_stdout);
      fputs_unfiltered ("\n", gdb_stdout);
      exit (0);
    }

  /* FIXME: cagney/2003-02-03: The big hack (part 1 of 2) that lets
     GDB retain the old MI1 interpreter startup behavior.  Output the
     copyright message before the interpreter is installed.  That way
     it isn't encapsulated in MI output.  */
  if (!quiet && strcmp (interpreter_p, INTERP_MI1) == 0)
    {
      /* Print all the junk at the top, with trailing "..." if we are about
         to read a symbol file (possibly slowly).  */
      print_gdb_version (gdb_stdout);
      if (symarg)
	printf_filtered ("..");
      wrap_here ("");
      gdb_flush (gdb_stdout);	/* Force to screen during slow operations */
    }


  /* Install the default UI.  All the interpreters should have had a
     look at things by now.  Initialize the default interpreter. */

  {
    /* Find it.  */
    struct interp *interp = interp_lookup (interpreter_p);
    if (interp == NULL)
      error ("Interpreter `%s' unrecognized", interpreter_p);
    /* Install it.  */
    if (!interp_set (interp))
      {
        fprintf_unfiltered (gdb_stderr,
			    "Interpreter `%s' failed to initialize.\n",
                            interpreter_p);
        exit (1);
      }
  }

  /* FIXME: cagney/2003-02-03: The big hack (part 2 of 2) that lets
     GDB retain the old MI1 interpreter startup behavior.  Output the
     copyright message after the interpreter is installed when it is
     any sane interpreter.  */
  if (!quiet && !current_interp_named_p (INTERP_MI1))
    {
      /* Print all the junk at the top, with trailing "..." if we are about
         to read a symbol file (possibly slowly).  */
      print_gdb_version (gdb_stdout);
      if (symarg)
	printf_filtered ("..");
      wrap_here ("");
      gdb_flush (gdb_stdout);	/* Force to screen during slow operations */
    }

  error_pre_print = "\n\n";
  quit_pre_print = error_pre_print;

  /* We may get more than one warning, don't double space all of them... */
  warning_pre_print = _("\nwarning: ");

  /* Read and execute $HOME/.gdbinit file, if it exists.  This is done
     *before* all the command line arguments are processed; it sets
     global parameters, which are independent of what file you are
     debugging or what directory you are in.  */
  homedir = getenv ("HOME");
  if (homedir)
    {
      homeinit = (char *) alloca (strlen (homedir) +
				  strlen (gdbinit) + 10);
      strcpy (homeinit, homedir);
      strcat (homeinit, "/");
      strcat (homeinit, gdbinit);

      if (!inhibit_gdbinit)
	{
	  catch_command_errors (source_command, homeinit, 0, RETURN_MASK_ALL);
	}

      /* Do stats; no need to do them elsewhere since we'll only
         need them if homedir is set.  Make sure that they are
         zero in case one of them fails (this guarantees that they
         won't match if either exists).  */

      memset (&homebuf, 0, sizeof (struct stat));
      memset (&cwdbuf, 0, sizeof (struct stat));

      stat (homeinit, &homebuf);
      stat (gdbinit, &cwdbuf);	/* We'll only need this if
				   homedir was set.  */
    }

  /* Now perform all the actions indicated by the arguments.  */
  if (cdarg != NULL)
    {
      catch_command_errors (cd_command, cdarg, 0, RETURN_MASK_ALL);
    }

  for (i = 0; i < ndir; i++)
    catch_command_errors (directory_command, dirarg[i], 0, RETURN_MASK_ALL);
  xfree (dirarg);

  if (execarg != NULL
      && symarg != NULL
      && strcmp (execarg, symarg) == 0)
    {
      /* The exec file and the symbol-file are the same.  If we can't
         open it, better only print one error message.
         catch_command_errors returns non-zero on success! */
      if (catch_command_errors (exec_file_attach, execarg, !batch, RETURN_MASK_ALL))
	catch_command_errors (symbol_file_add_main, symarg, 0, RETURN_MASK_ALL);
    }
  else
    {
      if (execarg != NULL)
	catch_command_errors (exec_file_attach, execarg, !batch, RETURN_MASK_ALL);
      if (symarg != NULL)
	catch_command_errors (symbol_file_add_main, symarg, 0, RETURN_MASK_ALL);
    }

  /* After the symbol file has been read, print a newline to get us
     beyond the copyright line...  But errors should still set off
     the error message with a (single) blank line.  */
  if (!quiet)
    printf_filtered ("\n");
  error_pre_print = "\n";
  quit_pre_print = error_pre_print;
  warning_pre_print = _("\nwarning: ");

  if (corearg != NULL)
    {
      /* corearg may be either a corefile or a pid.
	 If its first character is a digit, try attach first
	 and then corefile.  Otherwise try corefile first. */

      if (isdigit (corearg[0]))
	{
	  if (catch_command_errors (attach_command, corearg,
				    !batch, RETURN_MASK_ALL) == 0)
	    catch_command_errors (core_file_command, corearg,
				  !batch, RETURN_MASK_ALL);
	}
      else /* Can't be a pid, better be a corefile. */
	catch_command_errors (core_file_command, corearg,
			      !batch, RETURN_MASK_ALL);
    }

  if (ttyarg != NULL)
    catch_command_errors (tty_command, ttyarg, !batch, RETURN_MASK_ALL);

  /* Error messages should no longer be distinguished with extra output. */
  error_pre_print = NULL;
  quit_pre_print = NULL;
  warning_pre_print = _("warning: ");

  /* Read the .gdbinit file in the current directory, *if* it isn't
     the same as the $HOME/.gdbinit file (it should exist, also).  */

  if (!homedir
      || memcmp ((char *) &homebuf, (char *) &cwdbuf, sizeof (struct stat)))
    if (!inhibit_gdbinit)
      {
	catch_command_errors (source_command, gdbinit, 0, RETURN_MASK_ALL);
      }

  for (i = 0; i < ncmd; i++)
    {
#if 0
      /* NOTE: cagney/1999-11-03: SET_TOP_LEVEL() was a macro that
         expanded into a call to setjmp().  */
      if (!SET_TOP_LEVEL ()) /* NB: This is #if 0'd out */
	{
	  /* NOTE: I am commenting this out, because it is not clear
	     where this feature is used. It is very old and
	     undocumented. ezannoni: 1999-05-04 */
#if 0
	  if (cmdarg[i][0] == '-' && cmdarg[i][1] == '\0')
	    read_command_file (stdin);
	  else
#endif
	    source_command (cmdarg[i], !batch);
	  do_cleanups (ALL_CLEANUPS);
	}
#endif
      catch_command_errors (source_command, cmdarg[i], !batch, RETURN_MASK_ALL);
    }
  xfree (cmdarg);

  /* Read in the old history after all the command files have been read. */
  init_history ();

  if (batch)
    {
      /* We have hit the end of the batch file.  */
      exit (0);
    }

  /* Do any host- or target-specific hacks.  This is used for i960 targets
     to force the user to set a nindy target and spec its parameters.  */

#ifdef BEFORE_MAIN_LOOP_HOOK
  BEFORE_MAIN_LOOP_HOOK;
#endif

  /* Show time and/or space usage.  */

  if (display_time)
    {
      long init_time = get_run_time () - time_at_startup;

      printf_unfiltered (_("Startup time: %ld.%06ld\n"),
			 init_time / 1000000, init_time % 1000000);
    }

  if (display_space)
    {
#ifdef HAVE_SBRK
      extern char **environ;
      char *lim = (char *) sbrk (0);

      printf_unfiltered (_("Startup size: data size %ld\n"),
			 (long) (lim - (char *) &environ));
#endif
    }

#if 0
  /* FIXME: cagney/1999-11-06: The original main loop was like: */
  while (1)
    {
      if (!SET_TOP_LEVEL ())
	{
	  do_cleanups (ALL_CLEANUPS);	/* Do complete cleanup */
	  /* GUIs generally have their own command loop, mainloop, or whatever.
	     This is a good place to gain control because many error
	     conditions will end up here via longjmp(). */
	  if (command_loop_hook)
	    command_loop_hook ();
	  else
	    command_loop ();
	  quit_command ((char *) 0, instream == stdin);
	}
    }
  /* NOTE: If the command_loop() returned normally, the loop would
     attempt to exit by calling the function quit_command().  That
     function would either call exit() or throw an error returning
     control to SET_TOP_LEVEL. */
  /* NOTE: The function do_cleanups() was called once each time round
     the loop.  The usefulness of the call isn't clear.  If an error
     was thrown, everything would have already been cleaned up.  If
     command_loop() returned normally and quit_command() was called,
     either exit() or error() (again cleaning up) would be called. */
#endif
  /* NOTE: cagney/1999-11-07: There is probably no reason for not
     moving this loop and the code found in captured_command_loop()
     into the command_loop() proper.  The main thing holding back that
     change - SET_TOP_LEVEL() - has been eliminated. */
  while (1)
    {
      catch_errors (captured_command_loop, 0, "", RETURN_MASK_ALL);
    }
  /* No exit -- exit is through quit_command.  */
}

int
gdb_main (struct captured_main_args *args)
{
  use_windows = args->use_windows;
  catch_errors (captured_main, args, "", RETURN_MASK_ALL);
  /* The only way to end up here is by an error (normal exit is
     handled by quit_force()), hence always return an error status.  */
  return 1;
}


/* Don't use *_filtered for printing help.  We don't want to prompt
   for continue no matter how small the screen or how much we're going
   to print.  */

static void
print_gdb_help (struct ui_file *stream)
{
  fputs_unfiltered (_("\
This is the GNU debugger.  Usage:\n\n\
    gdb [options] [executable-file [core-file or process-id]]\n\
    gdb [options] --args executable-file [inferior-arguments ...]\n\n\
Options:\n\n\
"), stream);
  fputs_unfiltered (_("\
  --args             Arguments after executable-file are passed to inferior\n\
"), stream);
  fputs_unfiltered (_("\
  --[no]async        Enable (disable) asynchronous version of CLI\n\
"), stream);
  fputs_unfiltered (_("\
  -b BAUDRATE        Set serial port baud rate used for remote debugging.\n\
  --batch            Exit after processing options.\n\
  --cd=DIR           Change current directory to DIR.\n\
  --command=FILE     Execute GDB commands from FILE.\n\
  --core=COREFILE    Analyze the core dump COREFILE.\n\
  --pid=PID          Attach to running process PID.\n\
"), stream);
  fputs_unfiltered (_("\
  --dbx              DBX compatibility mode.\n\
  --directory=DIR    Search for source files in DIR.\n\
  --epoch            Output information used by epoch emacs-GDB interface.\n\
  --exec=EXECFILE    Use EXECFILE as the executable.\n\
  --fullname         Output information used by emacs-GDB interface.\n\
  --help             Print this message.\n\
"), stream);
  fputs_unfiltered (_("\
  --interpreter=INTERP\n\
                     Select a specific interpreter / user interface\n\
"), stream);
  fputs_unfiltered (_("\
  --mapped           Use mapped symbol files if supported on this system.\n\
  --nw		     Do not use a window interface.\n\
  --nx               Do not read "), stream);
  fputs_unfiltered (gdbinit, stream);
  fputs_unfiltered (_(" file.\n\
  --quiet            Do not print version number on startup.\n\
  --readnow          Fully read symbol files on first access.\n\
"), stream);
  fputs_unfiltered (_("\
  --se=FILE          Use FILE as symbol file and executable file.\n\
  --symbols=SYMFILE  Read symbols from SYMFILE.\n\
  --tty=TTY          Use TTY for input/output by the program being debugged.\n\
"), stream);
#if defined(TUI)
  fputs_unfiltered (_("\
  --tui              Use a terminal user interface.\n\
"), stream);
#endif
  fputs_unfiltered (_("\
  --version          Print version information and then exit.\n\
  -w                 Use a window interface.\n\
  --write            Set writing into executable and core files.\n\
  --xdb              XDB compatibility mode.\n\
"), stream);
  fputs_unfiltered (_("\n\
For more information, type \"help\" from within GDB, or consult the\n\
GDB manual (available as on-line info or a printed manual).\n\
Report bugs to \"bug-gdb@gnu.org\".\
"), stream);
}