* gdbthread.h (struct thread_info): Add comments around

[binutils-gdb.git] / gdb / infcmd.c

/* Memory-access and commands for "inferior" process, for GDB.

   Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
   2008 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 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 "defs.h"
#include <signal.h>
#include "gdb_string.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "frame.h"
#include "inferior.h"
#include "environ.h"
#include "value.h"
#include "gdbcmd.h"
#include "symfile.h"
#include "gdbcore.h"
#include "target.h"
#include "language.h"
#include "symfile.h"
#include "objfiles.h"
#include "completer.h"
#include "ui-out.h"
#include "event-top.h"
#include "parser-defs.h"
#include "regcache.h"
#include "reggroups.h"
#include "block.h"
#include "solib.h"
#include <ctype.h>
#include "gdb_assert.h"
#include "observer.h"
#include "target-descriptions.h"
#include "user-regs.h"
#include "exceptions.h"
#include "cli/cli-decode.h"
#include "gdbthread.h"

/* Functions exported for general use, in inferior.h: */

void all_registers_info (char *, int);

void registers_info (char *, int);

void nexti_command (char *, int);

void stepi_command (char *, int);

void continue_command (char *, int);

void interrupt_target_command (char *args, int from_tty);

/* Local functions: */

static void nofp_registers_info (char *, int);

static void print_return_value (struct type *func_type,
                                struct type *value_type);

static void until_next_command (int);

static void until_command (char *, int);

static void path_info (char *, int);

static void path_command (char *, int);

static void unset_command (char *, int);

static void float_info (char *, int);

static void detach_command (char *, int);

static void disconnect_command (char *, int);

static void unset_environment_command (char *, int);

static void set_environment_command (char *, int);

static void environment_info (char *, int);

static void program_info (char *, int);

static void finish_command (char *, int);

static void signal_command (char *, int);

static void jump_command (char *, int);

static void step_1 (int, int, char *);
static void step_once (int skip_subroutines, int single_inst, int count, int thread);

static void next_command (char *, int);

static void step_command (char *, int);

static void run_command (char *, int);

static void run_no_args_command (char *args, int from_tty);

static void go_command (char *line_no, int from_tty);

static int strip_bg_char (char **);

void _initialize_infcmd (void);

#define GO_USAGE   "Usage: go <location>\n"

#define ERROR_NO_INFERIOR \
   if (!target_has_execution) error (_("The program is not being run."));

/* String containing arguments to give to the program, separated by spaces.
   Empty string (pointer to '\0') means no args.  */

static char *inferior_args;

/* The inferior arguments as a vector.  If INFERIOR_ARGC is nonzero,
   then we must compute INFERIOR_ARGS from this (via the target).  */

static int inferior_argc;
static char **inferior_argv;

/* File name for default use for standard in/out in the inferior.  */

static char *inferior_io_terminal;

/* Pid of our debugged inferior, or 0 if no inferior now.
   Since various parts of infrun.c test this to see whether there is a program
   being debugged it should be nonzero (currently 3 is used) for remote
   debugging.  */

ptid_t inferior_ptid;

/* Last signal that the inferior received (why it stopped).  */

enum target_signal stop_signal;

/* Address at which inferior stopped.  */

CORE_ADDR stop_pc;

/* Flag indicating that a command has proceeded the inferior past the
   current breakpoint.  */

int breakpoint_proceeded;

/* Nonzero if stopped due to a step command.  */

int stop_step;

/* Nonzero if stopped due to completion of a stack dummy routine.  */

int stop_stack_dummy;

/* Nonzero if stopped due to a random (unexpected) signal in inferior
   process.  */

int stopped_by_random_signal;

/* If stepping, nonzero means step count is > 1
   so don't print frame next time inferior stops
   if it stops due to stepping.  */

int step_multi;

/* Environment to use for running inferior,
   in format described in environ.h.  */

struct gdb_environ *inferior_environ;

/* When set, no calls to target_resumed observer will be made.  */
int suppress_resume_observer = 0;
/* When set, normal_stop will not call the normal_stop observer.  */
int suppress_stop_observer = 0;
\f
/* Accessor routines. */

void 
set_inferior_io_terminal (const char *terminal_name)
{
  if (inferior_io_terminal)
    xfree (inferior_io_terminal);

  if (!terminal_name)
    inferior_io_terminal = NULL;
  else
    inferior_io_terminal = savestring (terminal_name, strlen (terminal_name));
}

const char *
get_inferior_io_terminal (void)
{
  return inferior_io_terminal;
}

char *
get_inferior_args (void)
{
  if (inferior_argc != 0)
    {
      char *n, *old;

      n = gdbarch_construct_inferior_arguments (current_gdbarch,
                                                inferior_argc, inferior_argv);
      old = set_inferior_args (n);
      xfree (old);
    }

  if (inferior_args == NULL)
    inferior_args = xstrdup ("");

  return inferior_args;
}

char *
set_inferior_args (char *newargs)
{
  char *saved_args = inferior_args;

  inferior_args = newargs;
  inferior_argc = 0;
  inferior_argv = 0;

  return saved_args;
}

void
set_inferior_args_vector (int argc, char **argv)
{
  inferior_argc = argc;
  inferior_argv = argv;
}

/* Notice when `set args' is run.  */
static void
notice_args_set (char *args, int from_tty, struct cmd_list_element *c)
{
  inferior_argc = 0;
  inferior_argv = 0;
}

/* Notice when `show args' is run.  */
static void
notice_args_read (struct ui_file *file, int from_tty,
                  struct cmd_list_element *c, const char *value)
{
  /* Note that we ignore the passed-in value in favor of computing it
     directly.  */
  deprecated_show_value_hack (file, from_tty, c, get_inferior_args ());
}

\f
/* Compute command-line string given argument vector.  This does the
   same shell processing as fork_inferior.  */
char *
construct_inferior_arguments (struct gdbarch *gdbarch, int argc, char **argv)
{
  char *result;

  if (STARTUP_WITH_SHELL)
    {
      /* This holds all the characters considered special to the
         typical Unix shells.  We include `^' because the SunOS
         /bin/sh treats it as a synonym for `|'.  */
      char *special = "\"!#$&*()\\|[]{}<>?'\"`~^; \t\n";
      int i;
      int length = 0;
      char *out, *cp;

      /* We over-compute the size.  It shouldn't matter.  */
      for (i = 0; i < argc; ++i)
        length += 2 * strlen (argv[i]) + 1 + 2 * (argv[i][0] == '\0');

      result = (char *) xmalloc (length);
      out = result;

      for (i = 0; i < argc; ++i)
        {
          if (i > 0)
            *out++ = ' ';

          /* Need to handle empty arguments specially.  */
          if (argv[i][0] == '\0')
            {
              *out++ = '\'';
              *out++ = '\'';
            }
          else
            {
              for (cp = argv[i]; *cp; ++cp)
                {
                  if (strchr (special, *cp) != NULL)
                    *out++ = '\\';
                  *out++ = *cp;
                }
            }
        }
      *out = '\0';
    }
  else
    {
      /* In this case we can't handle arguments that contain spaces,
         tabs, or newlines -- see breakup_args().  */
      int i;
      int length = 0;

      for (i = 0; i < argc; ++i)
        {
          char *cp = strchr (argv[i], ' ');
          if (cp == NULL)
            cp = strchr (argv[i], '\t');
          if (cp == NULL)
            cp = strchr (argv[i], '\n');
          if (cp != NULL)
            error (_("can't handle command-line argument containing whitespace"));
          length += strlen (argv[i]) + 1;
        }

      result = (char *) xmalloc (length);
      result[0] = '\0';
      for (i = 0; i < argc; ++i)
        {
          if (i > 0)
            strcat (result, " ");
          strcat (result, argv[i]);
        }
    }

  return result;
}
\f

/* This function detects whether or not a '&' character (indicating
   background execution) has been added as *the last* of the arguments ARGS
   of a command. If it has, it removes it and returns 1. Otherwise it
   does nothing and returns 0. */
static int
strip_bg_char (char **args)
{
  char *p = NULL;

  p = strchr (*args, '&');

  if (p)
    {
      if (p == (*args + strlen (*args) - 1))
        {
          if (strlen (*args) > 1)
            {
              do
                p--;
              while (*p == ' ' || *p == '\t');
              *(p + 1) = '\0';
            }
          else
            *args = 0;
          return 1;
        }
    }
  return 0;
}

void
tty_command (char *file, int from_tty)
{
  if (file == 0)
    error_no_arg (_("terminal name for running target process"));

  set_inferior_io_terminal (file);
}

/* Common actions to take after creating any sort of inferior, by any
   means (running, attaching, connecting, et cetera).  The target
   should be stopped.  */

void
post_create_inferior (struct target_ops *target, int from_tty)
{
  /* Be sure we own the terminal in case write operations are performed.  */ 
  target_terminal_ours ();

  /* If the target hasn't taken care of this already, do it now.
     Targets which need to access registers during to_open,
     to_create_inferior, or to_attach should do it earlier; but many
     don't need to.  */
  target_find_description ();

  if (exec_bfd)
    {
      /* Sometimes the platform-specific hook loads initial shared
         libraries, and sometimes it doesn't.  Try to do so first, so
         that we can add them with the correct value for FROM_TTY.
         If we made all the inferior hook methods consistent,
         this call could be removed.  */
#ifdef SOLIB_ADD
      SOLIB_ADD (NULL, from_tty, target, auto_solib_add);
#else
      solib_add (NULL, from_tty, target, auto_solib_add);
#endif

      /* Create the hooks to handle shared library load and unload
         events.  */
#ifdef SOLIB_CREATE_INFERIOR_HOOK
      SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
#else
      solib_create_inferior_hook ();
#endif
    }

  observer_notify_inferior_created (target, from_tty);
}

/* Kill the inferior if already running.  This function is designed
   to be called when we are about to start the execution of the program
   from the beginning.  Ask the user to confirm that he wants to restart
   the program being debugged when FROM_TTY is non-null.  */

static void
kill_if_already_running (int from_tty)
{
  if (! ptid_equal (inferior_ptid, null_ptid) && target_has_execution)
    {
      /* Bail out before killing the program if we will not be able to
         restart it.  */
      target_require_runnable ();

      if (from_tty
          && !query ("The program being debugged has been started already.\n\
Start it from the beginning? "))
        error (_("Program not restarted."));
      target_kill ();
      no_shared_libraries (NULL, from_tty);
      init_wait_for_inferior ();
    }
}

/* Implement the "run" command. If TBREAK_AT_MAIN is set, then insert
   a temporary breakpoint at the begining of the main program before
   running the program.  */

static void
run_command_1 (char *args, int from_tty, int tbreak_at_main)
{
  char *exec_file;

  dont_repeat ();

  kill_if_already_running (from_tty);
  clear_breakpoint_hit_counts ();

  /* Clean up any leftovers from other runs.  Some other things from
     this function should probably be moved into target_pre_inferior.  */
  target_pre_inferior (from_tty);

  /* The comment here used to read, "The exec file is re-read every
     time we do a generic_mourn_inferior, so we just have to worry
     about the symbol file."  The `generic_mourn_inferior' function
     gets called whenever the program exits.  However, suppose the
     program exits, and *then* the executable file changes?  We need
     to check again here.  Since reopen_exec_file doesn't do anything
     if the timestamp hasn't changed, I don't see the harm.  */
  reopen_exec_file ();
  reread_symbols ();

  /* Insert the temporary breakpoint if a location was specified.  */
  if (tbreak_at_main)
    tbreak_command (main_name (), 0);

  exec_file = (char *) get_exec_file (0);

  if (non_stop && !target_supports_non_stop ())
    error (_("The target does not support running in non-stop mode."));

  /* We keep symbols from add-symbol-file, on the grounds that the
     user might want to add some symbols before running the program
     (right?).  But sometimes (dynamic loading where the user manually
     introduces the new symbols with add-symbol-file), the code which
     the symbols describe does not persist between runs.  Currently
     the user has to manually nuke all symbols between runs if they
     want them to go away (PR 2207).  This is probably reasonable.  */

  if (!args)
    {
      if (target_can_async_p ())
        async_disable_stdin ();
    }
  else
    {
      int async_exec = strip_bg_char (&args);

      /* If we get a request for running in the bg but the target
         doesn't support it, error out. */
      if (async_exec && !target_can_async_p ())
        error (_("Asynchronous execution not supported on this target."));

      /* If we don't get a request of running in the bg, then we need
         to simulate synchronous (fg) execution. */
      if (!async_exec && target_can_async_p ())
        {
          /* Simulate synchronous execution */
          async_disable_stdin ();
        }

      /* If there were other args, beside '&', process them. */
      if (args)
        {
          char *old_args = set_inferior_args (xstrdup (args));
          xfree (old_args);
        }
    }

  if (from_tty)
    {
      ui_out_field_string (uiout, NULL, "Starting program");
      ui_out_text (uiout, ": ");
      if (exec_file)
        ui_out_field_string (uiout, "execfile", exec_file);
      ui_out_spaces (uiout, 1);
      /* We call get_inferior_args() because we might need to compute
         the value now.  */
      ui_out_field_string (uiout, "infargs", get_inferior_args ());
      ui_out_text (uiout, "\n");
      ui_out_flush (uiout);
    }

  /* We call get_inferior_args() because we might need to compute
     the value now.  */
  target_create_inferior (exec_file, get_inferior_args (),
                          environ_vector (inferior_environ), from_tty);

  /* Pass zero for FROM_TTY, because at this point the "run" command
     has done its thing; now we are setting up the running program.  */
  post_create_inferior (&current_target, 0);

  /* Start the target running.  */
  proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0);
}


static void
run_command (char *args, int from_tty)
{
  run_command_1 (args, from_tty, 0);
}

static void
run_no_args_command (char *args, int from_tty)
{
  char *old_args = set_inferior_args (xstrdup (""));
  xfree (old_args);
}
\f

/* Start the execution of the program up until the beginning of the main
   program.  */

static void
start_command (char *args, int from_tty)
{
  /* Some languages such as Ada need to search inside the program
     minimal symbols for the location where to put the temporary
     breakpoint before starting.  */
  if (!have_minimal_symbols ())
    error (_("No symbol table loaded.  Use the \"file\" command."));

  /* Run the program until reaching the main procedure...  */
  run_command_1 (args, from_tty, 1);
} 

static int
proceed_thread_callback (struct thread_info *thread, void *arg)
{
  if (!is_stopped (thread->ptid))
    return 0;

  context_switch_to (thread->ptid);
  clear_proceed_status ();
  proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);
  return 0;
}

void
continue_1 (int all_threads)
{
  ERROR_NO_INFERIOR;

  if (non_stop && all_threads)
    {
      /* Don't error out if the current thread is running, because
        there may be other stopped threads.  */
      struct cleanup *old_chain;

      /* Backup current thread and selected frame.  */
      old_chain = make_cleanup_restore_current_thread ();

      iterate_over_threads (proceed_thread_callback, NULL);

      /* Restore selected ptid.  */
      do_cleanups (old_chain);
    }
  else
    {
      ensure_not_running ();
      clear_proceed_status ();
      proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);
    }
}

/* continue [-a] [proceed-count] [&]  */
void
continue_command (char *args, int from_tty)
{
  int async_exec = 0;
  int all_threads = 0;
  ERROR_NO_INFERIOR;

  /* Find out whether we must run in the background. */
  if (args != NULL)
    async_exec = strip_bg_char (&args);

  /* If we must run in the background, but the target can't do it,
     error out. */
  if (async_exec && !target_can_async_p ())
    error (_("Asynchronous execution not supported on this target."));

  /* If we are not asked to run in the bg, then prepare to run in the
     foreground, synchronously. */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution */
      async_disable_stdin ();
    }

  if (args != NULL)
    {
      if (strncmp (args, "-a", sizeof ("-a") - 1) == 0)
        {
          all_threads = 1;
          args += sizeof ("-a") - 1;
          if (*args == '\0')
            args = NULL;
        }
    }

  if (!non_stop && all_threads)
    error (_("`-a' is meaningless in all-stop mode."));

  if (args != NULL && all_threads)
    error (_("\
Can't resume all threads and specify proceed count simultaneously."));

  /* If we have an argument left, set proceed count of breakpoint we
     stopped at.  */
  if (args != NULL)
    {
      bpstat bs = NULL;
      int num, stat;
      int stopped = 0;
      struct thread_info *tp;

      if (non_stop)
        tp = find_thread_pid (inferior_ptid);
      else
        {
          ptid_t last_ptid;
          struct target_waitstatus ws;

          get_last_target_status (&last_ptid, &ws);
          tp = find_thread_pid (last_ptid);
        }
      if (tp != NULL)
        bs = tp->stop_bpstat;

      while ((stat = bpstat_num (&bs, &num)) != 0)
        if (stat > 0)
          {
            set_ignore_count (num,
                              parse_and_eval_long (args) - 1,
                              from_tty);
            /* set_ignore_count prints a message ending with a period.
               So print two spaces before "Continuing.".  */
            if (from_tty)
              printf_filtered ("  ");
            stopped = 1;
          }

      if (!stopped && from_tty)
        {
          printf_filtered
            ("Not stopped at any breakpoint; argument ignored.\n");
        }
    }

  if (from_tty)
    printf_filtered (_("Continuing.\n"));

  continue_1 (all_threads);
}
\f
/* Step until outside of current statement.  */

static void
step_command (char *count_string, int from_tty)
{
  step_1 (0, 0, count_string);
}

/* Likewise, but skip over subroutine calls as if single instructions.  */

static void
next_command (char *count_string, int from_tty)
{
  step_1 (1, 0, count_string);
}

/* Likewise, but step only one instruction.  */

void
stepi_command (char *count_string, int from_tty)
{
  step_1 (0, 1, count_string);
}

void
nexti_command (char *count_string, int from_tty)
{
  step_1 (1, 1, count_string);
}

static void
delete_longjmp_breakpoint_cleanup (void *arg)
{
  int thread = * (int *) arg;
  delete_longjmp_breakpoint (thread);
}

static void
step_1 (int skip_subroutines, int single_inst, char *count_string)
{
  int count = 1;
  struct frame_info *frame;
  struct cleanup *cleanups = make_cleanup (null_cleanup, NULL);
  int async_exec = 0;
  int thread = -1;

  ERROR_NO_INFERIOR;
  ensure_not_running ();

  if (count_string)
    async_exec = strip_bg_char (&count_string);

  /* If we get a request for running in the bg but the target
     doesn't support it, error out. */
  if (async_exec && !target_can_async_p ())
    error (_("Asynchronous execution not supported on this target."));

  /* If we don't get a request of running in the bg, then we need
     to simulate synchronous (fg) execution. */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution */
      async_disable_stdin ();
    }

  count = count_string ? parse_and_eval_long (count_string) : 1;

  if (!single_inst || skip_subroutines)         /* leave si command alone */
    {
      if (in_thread_list (inferior_ptid))
        thread = pid_to_thread_id (inferior_ptid);

      set_longjmp_breakpoint ();

      make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
    }

  /* In synchronous case, all is well, just use the regular for loop. */
  if (!target_can_async_p ())
    {
      for (; count > 0; count--)
        {
          struct thread_info *tp = inferior_thread ();
          clear_proceed_status ();

          frame = get_current_frame ();
          tp->step_frame_id = get_frame_id (frame);

          if (!single_inst)
            {
              find_pc_line_pc_range (stop_pc,
                                     &tp->step_range_start, &tp->step_range_end);
              if (tp->step_range_end == 0)
                {
                  char *name;
                  if (find_pc_partial_function (stop_pc, &name,
                                                &tp->step_range_start,
                                                &tp->step_range_end) == 0)
                    error (_("Cannot find bounds of current function"));

                  target_terminal_ours ();
                  printf_filtered (_("\
Single stepping until exit from function %s, \n\
which has no line number information.\n"), name);
                }
            }
          else
            {
              /* Say we are stepping, but stop after one insn whatever it does.  */
              tp->step_range_start = tp->step_range_end = 1;
              if (!skip_subroutines)
                /* It is stepi.
                   Don't step over function calls, not even to functions lacking
                   line numbers.  */
                tp->step_over_calls = STEP_OVER_NONE;
            }

          if (skip_subroutines)
            tp->step_over_calls = STEP_OVER_ALL;

          step_multi = (count > 1);
          proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 1);

          if (!stop_step)
            break;
        }

      do_cleanups (cleanups);
      return;
    }
  /* In case of asynchronous target things get complicated, do only
     one step for now, before returning control to the event loop. Let
     the continuation figure out how many other steps we need to do,
     and handle them one at the time, through step_once(). */
  else
    {
      step_once (skip_subroutines, single_inst, count, thread);
      /* We are running, and the continuation is installed.  It will
         disable the longjmp breakpoint as appropriate.  */
      discard_cleanups (cleanups);
    }
}

struct step_1_continuation_args
{
  int count;
  int skip_subroutines;
  int single_inst;
  int thread;
};

/* Called after we are done with one step operation, to check whether
   we need to step again, before we print the prompt and return control
   to the user. If count is > 1, we will need to do one more call to
   proceed(), via step_once(). Basically it is like step_once and
   step_1_continuation are co-recursive. */
static void
step_1_continuation (void *args)
{
  struct step_1_continuation_args *a = args;

  if (!step_multi || !stop_step)
    {
      /* If we stopped for some reason that is not stepping there are
         no further steps to make.  Cleanup.  */
      if (!a->single_inst || a->skip_subroutines)
        delete_longjmp_breakpoint (a->thread);
      step_multi = 0;
    }
  else
    step_once (a->skip_subroutines, a->single_inst, a->count - 1, a->thread);
}

/* Do just one step operation. If count >1 we will have to set up a
   continuation to be done after the target stops (after this one
   step). This is useful to implement the 'step n' kind of commands, in
   case of asynchronous targets. We had to split step_1 into two parts,
   one to be done before proceed() and one afterwards. This function is
   called in case of step n with n>1, after the first step operation has
   been completed.*/
static void 
step_once (int skip_subroutines, int single_inst, int count, int thread)
{
  struct frame_info *frame;
  struct step_1_continuation_args *args;

  if (count > 0)
    {
      /* Don't assume THREAD is a valid thread id.  It is set to -1 if
         the longjmp breakpoint was not required.  Use the
         INFERIOR_PTID thread instead, which is the same thread when
         THREAD is set.  */
      struct thread_info *tp = inferior_thread ();
      clear_proceed_status ();

      frame = get_current_frame ();
      if (!frame)               /* Avoid coredump here.  Why tho? */
        error (_("No current frame"));
      tp->step_frame_id = get_frame_id (frame);

      if (!single_inst)
        {
          find_pc_line_pc_range (stop_pc,
                                 &tp->step_range_start, &tp->step_range_end);

          /* If we have no line info, switch to stepi mode.  */
          if (tp->step_range_end == 0 && step_stop_if_no_debug)
            {
              tp->step_range_start = tp->step_range_end = 1;
            }
          else if (tp->step_range_end == 0)
            {
              char *name;
              if (find_pc_partial_function (stop_pc, &name,
                                            &tp->step_range_start,
                                            &tp->step_range_end) == 0)
                error (_("Cannot find bounds of current function"));

              target_terminal_ours ();
              printf_filtered (_("\
Single stepping until exit from function %s, \n\
which has no line number information.\n"), name);
            }
        }
      else
        {
          /* Say we are stepping, but stop after one insn whatever it does.  */
          tp->step_range_start = tp->step_range_end = 1;
          if (!skip_subroutines)
            /* It is stepi.
               Don't step over function calls, not even to functions lacking
               line numbers.  */
            tp->step_over_calls = STEP_OVER_NONE;
        }

      if (skip_subroutines)
        tp->step_over_calls = STEP_OVER_ALL;

      step_multi = (count > 1);
      proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 1);

      args = xmalloc (sizeof (*args));
      args->skip_subroutines = skip_subroutines;
      args->single_inst = single_inst;
      args->count = count;
      args->thread = thread;
      add_intermediate_continuation (step_1_continuation, args, xfree);
    }
}

\f
/* Continue program at specified address.  */

static void
jump_command (char *arg, int from_tty)
{
  CORE_ADDR addr;
  struct symtabs_and_lines sals;
  struct symtab_and_line sal;
  struct symbol *fn;
  struct symbol *sfn;
  int async_exec = 0;

  ERROR_NO_INFERIOR;
  ensure_not_running ();

  /* Find out whether we must run in the background. */
  if (arg != NULL)
    async_exec = strip_bg_char (&arg);

  /* If we must run in the background, but the target can't do it,
     error out. */
  if (async_exec && !target_can_async_p ())
    error (_("Asynchronous execution not supported on this target."));

  if (!arg)
    error_no_arg (_("starting address"));

  sals = decode_line_spec_1 (arg, 1);
  if (sals.nelts != 1)
    {
      error (_("Unreasonable jump request"));
    }

  sal = sals.sals[0];
  xfree (sals.sals);

  if (sal.symtab == 0 && sal.pc == 0)
    error (_("No source file has been specified."));

  resolve_sal_pc (&sal);        /* May error out */

  /* See if we are trying to jump to another function. */
  fn = get_frame_function (get_current_frame ());
  sfn = find_pc_function (sal.pc);
  if (fn != NULL && sfn != fn)
    {
      if (!query ("Line %d is not in `%s'.  Jump anyway? ", sal.line,
                  SYMBOL_PRINT_NAME (fn)))
        {
          error (_("Not confirmed."));
          /* NOTREACHED */
        }
    }

  if (sfn != NULL)
    {
      fixup_symbol_section (sfn, 0);
      if (section_is_overlay (SYMBOL_OBJ_SECTION (sfn)) &&
          !section_is_mapped (SYMBOL_OBJ_SECTION (sfn)))
        {
          if (!query ("WARNING!!!  Destination is in unmapped overlay!  Jump anyway? "))
            {
              error (_("Not confirmed."));
              /* NOTREACHED */
            }
        }
    }

  addr = sal.pc;

  if (from_tty)
    {
      printf_filtered (_("Continuing at "));
      fputs_filtered (paddress (addr), gdb_stdout);
      printf_filtered (".\n");
    }

  /* If we are not asked to run in the bg, then prepare to run in the
     foreground, synchronously. */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution */
      async_disable_stdin ();
    }

  clear_proceed_status ();
  proceed (addr, TARGET_SIGNAL_0, 0);
}
\f

/* Go to line or address in current procedure */
static void
go_command (char *line_no, int from_tty)
{
  if (line_no == (char *) NULL || !*line_no)
    printf_filtered (GO_USAGE);
  else
    {
      tbreak_command (line_no, from_tty);
      jump_command (line_no, from_tty);
    }
}
\f

/* Continue program giving it specified signal.  */

static void
signal_command (char *signum_exp, int from_tty)
{
  enum target_signal oursig;
  int async_exec = 0;

  dont_repeat ();               /* Too dangerous.  */
  ERROR_NO_INFERIOR;
  ensure_not_running ();

  /* Find out whether we must run in the background.  */
  if (signum_exp != NULL)
    async_exec = strip_bg_char (&signum_exp);

  /* If we must run in the background, but the target can't do it,
     error out.  */
  if (async_exec && !target_can_async_p ())
    error (_("Asynchronous execution not supported on this target."));

  /* If we are not asked to run in the bg, then prepare to run in the
     foreground, synchronously.  */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution.  */
      async_disable_stdin ();
    }

  if (!signum_exp)
    error_no_arg (_("signal number"));

  /* It would be even slicker to make signal names be valid expressions,
     (the type could be "enum $signal" or some such), then the user could
     assign them to convenience variables.  */
  oursig = target_signal_from_name (signum_exp);

  if (oursig == TARGET_SIGNAL_UNKNOWN)
    {
      /* No, try numeric.  */
      int num = parse_and_eval_long (signum_exp);

      if (num == 0)
        oursig = TARGET_SIGNAL_0;
      else
        oursig = target_signal_from_command (num);
    }

  if (from_tty)
    {
      if (oursig == TARGET_SIGNAL_0)
        printf_filtered (_("Continuing with no signal.\n"));
      else
        printf_filtered (_("Continuing with signal %s.\n"),
                         target_signal_to_name (oursig));
    }

  clear_proceed_status ();
  /* "signal 0" should not get stuck if we are stopped at a breakpoint.
     FIXME: Neither should "signal foo" but when I tried passing
     (CORE_ADDR)-1 unconditionally I got a testsuite failure which I haven't
     tried to track down yet.  */
  proceed (oursig == TARGET_SIGNAL_0 ? (CORE_ADDR) -1 : stop_pc, oursig, 0);
}

/* Proceed until we reach a different source line with pc greater than
   our current one or exit the function.  We skip calls in both cases.

   Note that eventually this command should probably be changed so
   that only source lines are printed out when we hit the breakpoint
   we set.  This may involve changes to wait_for_inferior and the
   proceed status code.  */

static void
until_next_command (int from_tty)
{
  struct frame_info *frame;
  CORE_ADDR pc;
  struct symbol *func;
  struct symtab_and_line sal;
  struct thread_info *tp = inferior_thread ();

  clear_proceed_status ();

  frame = get_current_frame ();

  /* Step until either exited from this function or greater
     than the current line (if in symbolic section) or pc (if
     not). */

  pc = read_pc ();
  func = find_pc_function (pc);

  if (!func)
    {
      struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc);

      if (msymbol == NULL)
        error (_("Execution is not within a known function."));

      tp->step_range_start = SYMBOL_VALUE_ADDRESS (msymbol);
      tp->step_range_end = pc;
    }
  else
    {
      sal = find_pc_line (pc, 0);

      tp->step_range_start = BLOCK_START (SYMBOL_BLOCK_VALUE (func));
      tp->step_range_end = sal.end;
    }

  tp->step_over_calls = STEP_OVER_ALL;
  tp->step_frame_id = get_frame_id (frame);

  step_multi = 0;               /* Only one call to proceed */

  proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 1);
}

static void
until_command (char *arg, int from_tty)
{
  int async_exec = 0;

  if (!target_has_execution)
    error (_("The program is not running."));

  /* Find out whether we must run in the background. */
  if (arg != NULL)
    async_exec = strip_bg_char (&arg);

  /* If we must run in the background, but the target can't do it,
     error out. */
  if (async_exec && !target_can_async_p ())
    error (_("Asynchronous execution not supported on this target."));

  /* If we are not asked to run in the bg, then prepare to run in the
     foreground, synchronously. */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution */
      async_disable_stdin ();
    }

  if (arg)
    until_break_command (arg, from_tty, 0);
  else
    until_next_command (from_tty);
}

static void
advance_command (char *arg, int from_tty)
{
  int async_exec = 0;

  if (!target_has_execution)
    error (_("The program is not running."));

  if (arg == NULL)
    error_no_arg (_("a location"));

  /* Find out whether we must run in the background.  */
  if (arg != NULL)
    async_exec = strip_bg_char (&arg);

  /* If we must run in the background, but the target can't do it,
     error out.  */
  if (async_exec && !target_can_async_p ())
    error (_("Asynchronous execution not supported on this target."));

  /* If we are not asked to run in the bg, then prepare to run in the
     foreground, synchronously.  */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution.  */
      async_disable_stdin ();
    }

  until_break_command (arg, from_tty, 1);
}
\f
/* Print the result of a function at the end of a 'finish' command.  */

static void
print_return_value (struct type *func_type, struct type *value_type)
{
  struct gdbarch *gdbarch = current_gdbarch;
  struct cleanup *old_chain;
  struct ui_stream *stb;
  struct value *value;

  CHECK_TYPEDEF (value_type);
  gdb_assert (TYPE_CODE (value_type) != TYPE_CODE_VOID);

  /* FIXME: 2003-09-27: When returning from a nested inferior function
     call, it's possible (with no help from the architecture vector)
     to locate and return/print a "struct return" value.  This is just
     a more complicated case of what is already being done in in the
     inferior function call code.  In fact, when inferior function
     calls are made async, this will likely be made the norm.  */

  switch (gdbarch_return_value (gdbarch, func_type, value_type,
                                NULL, NULL, NULL))
    {
    case RETURN_VALUE_REGISTER_CONVENTION:
    case RETURN_VALUE_ABI_RETURNS_ADDRESS:
    case RETURN_VALUE_ABI_PRESERVES_ADDRESS:
      value = allocate_value (value_type);
      gdbarch_return_value (gdbarch, func_type, value_type, stop_registers,
                            value_contents_raw (value), NULL);
      break;
    case RETURN_VALUE_STRUCT_CONVENTION:
      value = NULL;
      break;
    default:
      internal_error (__FILE__, __LINE__, _("bad switch"));
    }

  if (value)
    {
      /* Print it.  */
      stb = ui_out_stream_new (uiout);
      old_chain = make_cleanup_ui_out_stream_delete (stb);
      ui_out_text (uiout, "Value returned is ");
      ui_out_field_fmt (uiout, "gdb-result-var", "$%d",
                        record_latest_value (value));
      ui_out_text (uiout, " = ");
      value_print (value, stb->stream, 0, Val_no_prettyprint);
      ui_out_field_stream (uiout, "return-value", stb);
      ui_out_text (uiout, "\n");
      do_cleanups (old_chain);
    }
  else
    {
      ui_out_text (uiout, "Value returned has type: ");
      ui_out_field_string (uiout, "return-type", TYPE_NAME (value_type));
      ui_out_text (uiout, ".");
      ui_out_text (uiout, " Cannot determine contents\n");
    }
}

/* Stuff that needs to be done by the finish command after the target
   has stopped.  In asynchronous mode, we wait for the target to stop
   in the call to poll or select in the event loop, so it is
   impossible to do all the stuff as part of the finish_command
   function itself.  The only chance we have to complete this command
   is in fetch_inferior_event, which is called by the event loop as
   soon as it detects that the target has stopped. This function is
   called via the cmd_continuation pointer.  */

struct finish_command_continuation_args
{
  struct breakpoint *breakpoint;
  struct symbol *function;
};

static void
finish_command_continuation (void *arg)
{
  struct finish_command_continuation_args *a = arg;

  bpstat bs = NULL;

  if (!ptid_equal (inferior_ptid, null_ptid)
      && target_has_execution
      && is_stopped (inferior_ptid))
    bs = inferior_thread ()->stop_bpstat;

  if (bpstat_find_breakpoint (bs, a->breakpoint) != NULL
      && a->function != NULL)
    {
      struct type *value_type;

      value_type = TYPE_TARGET_TYPE (SYMBOL_TYPE (a->function));
      if (!value_type)
        internal_error (__FILE__, __LINE__,
                        _("finish_command: function has no target type"));

      if (TYPE_CODE (value_type) != TYPE_CODE_VOID)
        print_return_value (SYMBOL_TYPE (a->function), value_type);
    }

  /* We suppress normal call of normal_stop observer and do it here so
     that that *stopped notification includes the return value.  */
  /* NOTE: This is broken in non-stop mode.  There is no guarantee the
     next stop will be in the same thread that we started doing a
     finish on.  This suppressing (or some other replacement means)
     should be a thread property.  */
  observer_notify_normal_stop (bs);
  suppress_stop_observer = 0;
  delete_breakpoint (a->breakpoint);
}

static void
finish_command_continuation_free_arg (void *arg)
{
  /* NOTE: See finish_command_continuation.  This would go away, if
     this suppressing is made a thread property.  */
  suppress_stop_observer = 0;
  xfree (arg);
}

/* "finish": Set a temporary breakpoint at the place the selected
   frame will return to, then continue.  */

static void
finish_command (char *arg, int from_tty)
{
  struct symtab_and_line sal;
  struct frame_info *frame;
  struct symbol *function;
  struct breakpoint *breakpoint;
  struct cleanup *old_chain;
  struct finish_command_continuation_args *cargs;
  struct thread_info *tp;

  int async_exec = 0;

  /* Find out whether we must run in the background.  */
  if (arg != NULL)
    async_exec = strip_bg_char (&arg);

  /* If we must run in the background, but the target can't do it,
     error out.  */
  if (async_exec && !target_can_async_p ())
    error (_("Asynchronous execution not supported on this target."));

  /* If we are not asked to run in the bg, then prepare to run in the
     foreground, synchronously.  */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution.  */
      async_disable_stdin ();
    }

  if (arg)
    error (_("The \"finish\" command does not take any arguments."));
  if (!target_has_execution)
    error (_("The program is not running."));

  frame = get_prev_frame (get_selected_frame (_("No selected frame.")));
  if (frame == 0)
    error (_("\"finish\" not meaningful in the outermost frame."));

  tp = inferior_thread ();

  clear_proceed_status ();

  sal = find_pc_line (get_frame_pc (frame), 0);
  sal.pc = get_frame_pc (frame);

  breakpoint = set_momentary_breakpoint (sal, get_frame_id (frame), bp_finish);

  old_chain = make_cleanup_delete_breakpoint (breakpoint);

  /* Find the function we will return from.  */

  function = find_pc_function (get_frame_pc (get_selected_frame (NULL)));

  /* Print info on the selected frame, including level number but not
     source.  */
  if (from_tty)
    {
      printf_filtered (_("Run till exit from "));
      print_stack_frame (get_selected_frame (NULL), 1, LOCATION);
    }

  tp->proceed_to_finish = 1;    /* We want stop_registers, please...  */
  make_cleanup_restore_integer (&suppress_stop_observer);
  suppress_stop_observer = 1;
  proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);

  cargs = xmalloc (sizeof (*cargs));

  cargs->breakpoint = breakpoint;
  cargs->function = function;
  add_continuation (finish_command_continuation, cargs,
                    finish_command_continuation_free_arg);

  discard_cleanups (old_chain);
  if (!target_can_async_p ())
    do_all_continuations ();
}
\f

static void
program_info (char *args, int from_tty)
{
  bpstat bs;
  int num, stat;
  struct thread_info *tp;
  ptid_t ptid;

  if (!target_has_execution)
    {
      printf_filtered (_("The program being debugged is not being run.\n"));
      return;
    }

  if (non_stop)
    ptid = inferior_ptid;
  else
    {
      struct target_waitstatus ws;
      get_last_target_status (&ptid, &ws);
    }

  if (ptid_equal (ptid, null_ptid) || is_exited (ptid))
    error (_("Invalid selected thread."));
  else if (is_running (ptid))
    error (_("Selected thread is running."));

  tp = find_thread_pid (ptid);
  bs = tp->stop_bpstat;
  stat = bpstat_num (&bs, &num);

  target_files_info ();
  printf_filtered (_("Program stopped at %s.\n"),
                   hex_string ((unsigned long) stop_pc));
  if (stop_step)
    printf_filtered (_("It stopped after being stepped.\n"));
  else if (stat != 0)
    {
      /* There may be several breakpoints in the same place, so this
         isn't as strange as it seems.  */
      while (stat != 0)
        {
          if (stat < 0)
            {
              printf_filtered (_("\
It stopped at a breakpoint that has since been deleted.\n"));
            }
          else
            printf_filtered (_("It stopped at breakpoint %d.\n"), num);
          stat = bpstat_num (&bs, &num);
        }
    }
  else if (stop_signal != TARGET_SIGNAL_0)
    {
      printf_filtered (_("It stopped with signal %s, %s.\n"),
                       target_signal_to_name (stop_signal),
                       target_signal_to_string (stop_signal));
    }

  if (!from_tty)
    {
      printf_filtered (_("\
Type \"info stack\" or \"info registers\" for more information.\n"));
    }
}
\f
static void
environment_info (char *var, int from_tty)
{
  if (var)
    {
      char *val = get_in_environ (inferior_environ, var);
      if (val)
        {
          puts_filtered (var);
          puts_filtered (" = ");
          puts_filtered (val);
          puts_filtered ("\n");
        }
      else
        {
          puts_filtered ("Environment variable \"");
          puts_filtered (var);
          puts_filtered ("\" not defined.\n");
        }
    }
  else
    {
      char **vector = environ_vector (inferior_environ);
      while (*vector)
        {
          puts_filtered (*vector++);
          puts_filtered ("\n");
        }
    }
}

static void
set_environment_command (char *arg, int from_tty)
{
  char *p, *val, *var;
  int nullset = 0;

  if (arg == 0)
    error_no_arg (_("environment variable and value"));

  /* Find seperation between variable name and value */
  p = (char *) strchr (arg, '=');
  val = (char *) strchr (arg, ' ');

  if (p != 0 && val != 0)
    {
      /* We have both a space and an equals.  If the space is before the
         equals, walk forward over the spaces til we see a nonspace 
         (possibly the equals). */
      if (p > val)
        while (*val == ' ')
          val++;

      /* Now if the = is after the char following the spaces,
         take the char following the spaces.  */
      if (p > val)
        p = val - 1;
    }
  else if (val != 0 && p == 0)
    p = val;

  if (p == arg)
    error_no_arg (_("environment variable to set"));

  if (p == 0 || p[1] == 0)
    {
      nullset = 1;
      if (p == 0)
        p = arg + strlen (arg); /* So that savestring below will work */
    }
  else
    {
      /* Not setting variable value to null */
      val = p + 1;
      while (*val == ' ' || *val == '\t')
        val++;
    }

  while (p != arg && (p[-1] == ' ' || p[-1] == '\t'))
    p--;

  var = savestring (arg, p - arg);
  if (nullset)
    {
      printf_filtered (_("\
Setting environment variable \"%s\" to null value.\n"),
                       var);
      set_in_environ (inferior_environ, var, "");
    }
  else
    set_in_environ (inferior_environ, var, val);
  xfree (var);
}

static void
unset_environment_command (char *var, int from_tty)
{
  if (var == 0)
    {
      /* If there is no argument, delete all environment variables.
         Ask for confirmation if reading from the terminal.  */
      if (!from_tty || query (_("Delete all environment variables? ")))
        {
          free_environ (inferior_environ);
          inferior_environ = make_environ ();
        }
    }
  else
    unset_in_environ (inferior_environ, var);
}

/* Handle the execution path (PATH variable) */

static const char path_var_name[] = "PATH";

static void
path_info (char *args, int from_tty)
{
  puts_filtered ("Executable and object file path: ");
  puts_filtered (get_in_environ (inferior_environ, path_var_name));
  puts_filtered ("\n");
}

/* Add zero or more directories to the front of the execution path.  */

static void
path_command (char *dirname, int from_tty)
{
  char *exec_path;
  char *env;
  dont_repeat ();
  env = get_in_environ (inferior_environ, path_var_name);
  /* Can be null if path is not set */
  if (!env)
    env = "";
  exec_path = xstrdup (env);
  mod_path (dirname, &exec_path);
  set_in_environ (inferior_environ, path_var_name, exec_path);
  xfree (exec_path);
  if (from_tty)
    path_info ((char *) NULL, from_tty);
}
\f

/* Print out the machine register regnum. If regnum is -1, print all
   registers (print_all == 1) or all non-float and non-vector
   registers (print_all == 0).

   For most machines, having all_registers_info() print the
   register(s) one per line is good enough.  If a different format is
   required, (eg, for MIPS or Pyramid 90x, which both have lots of
   regs), or there is an existing convention for showing all the
   registers, define the architecture method PRINT_REGISTERS_INFO to
   provide that format.  */

void
default_print_registers_info (struct gdbarch *gdbarch,
                              struct ui_file *file,
                              struct frame_info *frame,
                              int regnum, int print_all)
{
  int i;
  const int numregs = gdbarch_num_regs (gdbarch)
                      + gdbarch_num_pseudo_regs (gdbarch);
  gdb_byte buffer[MAX_REGISTER_SIZE];

  for (i = 0; i < numregs; i++)
    {
      /* Decide between printing all regs, non-float / vector regs, or
         specific reg.  */
      if (regnum == -1)
        {
          if (print_all)
            {
              if (!gdbarch_register_reggroup_p (gdbarch, i, all_reggroup))
                continue;
            }
          else
            {
              if (!gdbarch_register_reggroup_p (gdbarch, i, general_reggroup))
                continue;
            }
        }
      else
        {
          if (i != regnum)
            continue;
        }

      /* If the register name is empty, it is undefined for this
         processor, so don't display anything.  */
      if (gdbarch_register_name (gdbarch, i) == NULL
          || *(gdbarch_register_name (gdbarch, i)) == '\0')
        continue;

      fputs_filtered (gdbarch_register_name (gdbarch, i), file);
      print_spaces_filtered (15 - strlen (gdbarch_register_name
                                          (gdbarch, i)), file);

      /* Get the data in raw format.  */
      if (! frame_register_read (frame, i, buffer))
        {
          fprintf_filtered (file, "*value not available*\n");
          continue;
        }

      /* If virtual format is floating, print it that way, and in raw
         hex.  */
      if (TYPE_CODE (register_type (gdbarch, i)) == TYPE_CODE_FLT
          || TYPE_CODE (register_type (gdbarch, i)) == TYPE_CODE_DECFLOAT)
        {
          int j;

          val_print (register_type (gdbarch, i), buffer, 0, 0,
                     file, 0, 1, 0, Val_pretty_default, current_language);

          fprintf_filtered (file, "\t(raw 0x");
          for (j = 0; j < register_size (gdbarch, i); j++)
            {
              int idx;
              if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
                idx = j;
              else
                idx = register_size (gdbarch, i) - 1 - j;
              fprintf_filtered (file, "%02x", (unsigned char) buffer[idx]);
            }
          fprintf_filtered (file, ")");
        }
      else
        {
          /* Print the register in hex.  */
          val_print (register_type (gdbarch, i), buffer, 0, 0,
                     file, 'x', 1, 0, Val_pretty_default, current_language);
          /* If not a vector register, print it also according to its
             natural format.  */
          if (TYPE_VECTOR (register_type (gdbarch, i)) == 0)
            {
              fprintf_filtered (file, "\t");
              val_print (register_type (gdbarch, i), buffer, 0, 0,
                         file, 0, 1, 0, Val_pretty_default, current_language);
            }
        }

      fprintf_filtered (file, "\n");
    }
}

void
registers_info (char *addr_exp, int fpregs)
{
  struct frame_info *frame;
  struct gdbarch *gdbarch;
  int regnum, numregs;
  char *end;

  if (!target_has_registers)
    error (_("The program has no registers now."));
  frame = get_selected_frame (NULL);
  gdbarch = get_frame_arch (frame);

  if (!addr_exp)
    {
      gdbarch_print_registers_info (gdbarch, gdb_stdout,
                                    frame, -1, fpregs);
      return;
    }

  while (*addr_exp != '\0')
    {
      char *start;
      const char *end;

      /* Keep skipping leading white space.  */
      if (isspace ((*addr_exp)))
        {
          addr_exp++;
          continue;
        }

      /* Discard any leading ``$''.  Check that there is something
         resembling a register following it.  */
      if (addr_exp[0] == '$')
        addr_exp++;
      if (isspace ((*addr_exp)) || (*addr_exp) == '\0')
        error (_("Missing register name"));

      /* Find the start/end of this register name/num/group.  */
      start = addr_exp;
      while ((*addr_exp) != '\0' && !isspace ((*addr_exp)))
        addr_exp++;
      end = addr_exp;

      /* Figure out what we've found and display it.  */

      /* A register name?  */
      {
        int regnum = user_reg_map_name_to_regnum (gdbarch, start, end - start);
        if (regnum >= 0)
          {
            /* User registers lie completely outside of the range of
               normal registers.  Catch them early so that the target
               never sees them.  */
            if (regnum >= gdbarch_num_regs (gdbarch)
                          + gdbarch_num_pseudo_regs (gdbarch))
              {
                struct value *val = value_of_user_reg (regnum, frame);

                printf_filtered ("%s: ", start);
                print_scalar_formatted (value_contents (val),
                                        check_typedef (value_type (val)),
                                        'x', 0, gdb_stdout);
                printf_filtered ("\n");
              }
            else
              gdbarch_print_registers_info (gdbarch, gdb_stdout,
                                            frame, regnum, fpregs);
            continue;
          }
      }

      /* A register number?  (how portable is this one?).  */
      {
        char *endptr;
        int regnum = strtol (start, &endptr, 0);
        if (endptr == end
            && regnum >= 0
            && regnum < gdbarch_num_regs (gdbarch)
                        + gdbarch_num_pseudo_regs (gdbarch))
          {
            gdbarch_print_registers_info (gdbarch, gdb_stdout,
                                          frame, regnum, fpregs);
            continue;
          }
      }

      /* A register group?  */
      {
        struct reggroup *group;
        for (group = reggroup_next (gdbarch, NULL);
             group != NULL;
             group = reggroup_next (gdbarch, group))
          {
            /* Don't bother with a length check.  Should the user
               enter a short register group name, go with the first
               group that matches.  */
            if (strncmp (start, reggroup_name (group), end - start) == 0)
              break;
          }
        if (group != NULL)
          {
            int regnum;
            for (regnum = 0;
                 regnum < gdbarch_num_regs (gdbarch)
                          + gdbarch_num_pseudo_regs (gdbarch);
                 regnum++)
              {
                if (gdbarch_register_reggroup_p (gdbarch, regnum, group))
                  gdbarch_print_registers_info (gdbarch,
                                                gdb_stdout, frame,
                                                regnum, fpregs);
              }
            continue;
          }
      }

      /* Nothing matched.  */
      error (_("Invalid register `%.*s'"), (int) (end - start), start);
    }
}

void
all_registers_info (char *addr_exp, int from_tty)
{
  registers_info (addr_exp, 1);
}

static void
nofp_registers_info (char *addr_exp, int from_tty)
{
  registers_info (addr_exp, 0);
}

static void
print_vector_info (struct gdbarch *gdbarch, struct ui_file *file,
                   struct frame_info *frame, const char *args)
{
  if (gdbarch_print_vector_info_p (gdbarch))
    gdbarch_print_vector_info (gdbarch, file, frame, args);
  else
    {
      int regnum;
      int printed_something = 0;

      for (regnum = 0;
           regnum < gdbarch_num_regs (gdbarch)
                    + gdbarch_num_pseudo_regs (gdbarch);
           regnum++)
        {
          if (gdbarch_register_reggroup_p (gdbarch, regnum, vector_reggroup))
            {
              printed_something = 1;
              gdbarch_print_registers_info (gdbarch, file, frame, regnum, 1);
            }
        }
      if (!printed_something)
        fprintf_filtered (file, "No vector information\n");
    }
}

static void
vector_info (char *args, int from_tty)
{
  if (!target_has_registers)
    error (_("The program has no registers now."));

  print_vector_info (current_gdbarch, gdb_stdout,
                     get_selected_frame (NULL), args);
}
\f

/*
 * TODO:
 * Should save/restore the tty state since it might be that the
 * program to be debugged was started on this tty and it wants
 * the tty in some state other than what we want.  If it's running
 * on another terminal or without a terminal, then saving and
 * restoring the tty state is a harmless no-op.
 * This only needs to be done if we are attaching to a process.
 */

/*
   attach_command --
   takes a program started up outside of gdb and ``attaches'' to it.
   This stops it cold in its tracks and allows us to start debugging it.
   and wait for the trace-trap that results from attaching.  */

static void
attach_command_post_wait (char *args, int from_tty, int async_exec)
{
  char *exec_file;
  char *full_exec_path = NULL;

  stop_soon = NO_STOP_QUIETLY;

  /* If no exec file is yet known, try to determine it from the
     process itself.  */
  exec_file = (char *) get_exec_file (0);
  if (!exec_file)
    {
      exec_file = target_pid_to_exec_file (PIDGET (inferior_ptid));
      if (exec_file)
        {
          /* It's possible we don't have a full path, but rather just a
             filename.  Some targets, such as HP-UX, don't provide the
             full path, sigh.

             Attempt to qualify the filename against the source path.
             (If that fails, we'll just fall back on the original
             filename.  Not much more we can do...)
           */
          if (!source_full_path_of (exec_file, &full_exec_path))
            full_exec_path = savestring (exec_file, strlen (exec_file));

          exec_file_attach (full_exec_path, from_tty);
          symbol_file_add_main (full_exec_path, from_tty);
        }
    }
  else
    {
      reopen_exec_file ();
      reread_symbols ();
    }

  /* Take any necessary post-attaching actions for this platform.  */
  target_post_attach (PIDGET (inferior_ptid));

  post_create_inferior (&current_target, from_tty);

  /* Install inferior's terminal modes.  */
  target_terminal_inferior ();

  if (async_exec)
    proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0);
  else
    {
      if (target_can_async_p ())
        async_enable_stdin ();
      normal_stop ();
      if (deprecated_attach_hook)
        deprecated_attach_hook ();
    }
}

struct attach_command_continuation_args
{
  char *args;
  int from_tty;
  int async_exec;
};

static void
attach_command_continuation (void *args)
{
  struct attach_command_continuation_args *a = args;
  attach_command_post_wait (a->args, a->from_tty, a->async_exec);
}

static void
attach_command_continuation_free_args (void *args)
{
  struct attach_command_continuation_args *a = args;
  xfree (a->args);
  xfree (a);
}

void
attach_command (char *args, int from_tty)
{
  char *exec_file;
  char *full_exec_path = NULL;
  int async_exec = 0;

  dont_repeat ();               /* Not for the faint of heart */

  if (target_has_execution)
    {
      if (query ("A program is being debugged already.  Kill it? "))
        target_kill ();
      else
        error (_("Not killed."));
    }

  /* Clean up any leftovers from other runs.  Some other things from
     this function should probably be moved into target_pre_inferior.  */
  target_pre_inferior (from_tty);

  if (non_stop && !target_supports_non_stop ())
    error (_("Cannot attach to this target in non-stop mode"));

  if (args)
    {
      async_exec = strip_bg_char (&args);

      /* If we get a request for running in the bg but the target
         doesn't support it, error out. */
      if (async_exec && !target_can_async_p ())
        error (_("Asynchronous execution not supported on this target."));
    }

  /* If we don't get a request of running in the bg, then we need
     to simulate synchronous (fg) execution.  */
  if (!async_exec && target_can_async_p ())
    {
      /* Simulate synchronous execution */
      async_disable_stdin ();
    }

  target_attach (args, from_tty);

  /* Set up the "saved terminal modes" of the inferior
     based on what modes we are starting it with.  */
  target_terminal_init ();

  /* Set up execution context to know that we should return from
     wait_for_inferior as soon as the target reports a stop.  */
  init_wait_for_inferior ();
  clear_proceed_status ();

  /* Some system don't generate traps when attaching to inferior.
     E.g. Mach 3 or GNU hurd.  */
  if (!target_attach_no_wait)
    {
      /* Careful here. See comments in inferior.h.  Basically some
         OSes don't ignore SIGSTOPs on continue requests anymore.  We
         need a way for handle_inferior_event to reset the stop_signal
         variable after an attach, and this is what
         STOP_QUIETLY_NO_SIGSTOP is for.  */
      stop_soon = STOP_QUIETLY_NO_SIGSTOP;

      if (target_can_async_p ())
        {
          /* sync_execution mode.  Wait for stop.  */
          struct attach_command_continuation_args *a;

          a = xmalloc (sizeof (*a));
          a->args = xstrdup (args);
          a->from_tty = from_tty;
          a->async_exec = async_exec;
          add_continuation (attach_command_continuation, a,
                            attach_command_continuation_free_args);
          return;
        }

      wait_for_inferior (0);
    }

  attach_command_post_wait (args, from_tty, async_exec);
}

/*
 * detach_command --
 * takes a program previously attached to and detaches it.
 * The program resumes execution and will no longer stop
 * on signals, etc.  We better not have left any breakpoints
 * in the program or it'll die when it hits one.  For this
 * to work, it may be necessary for the process to have been
 * previously attached.  It *might* work if the program was
 * started via the normal ptrace (PTRACE_TRACEME).
 */

static void
detach_command (char *args, int from_tty)
{
  dont_repeat ();               /* Not for the faint of heart.  */
  target_detach (args, from_tty);
  no_shared_libraries (NULL, from_tty);
  init_thread_list ();
  if (deprecated_detach_hook)
    deprecated_detach_hook ();
}

/* Disconnect from the current target without resuming it (leaving it
   waiting for a debugger).

   We'd better not have left any breakpoints in the program or the
   next debugger will get confused.  Currently only supported for some
   remote targets, since the normal attach mechanisms don't work on
   stopped processes on some native platforms (e.g. GNU/Linux).  */

static void
disconnect_command (char *args, int from_tty)
{
  dont_repeat ();               /* Not for the faint of heart */
  target_disconnect (args, from_tty);
  no_shared_libraries (NULL, from_tty);
  init_thread_list ();
  if (deprecated_detach_hook)
    deprecated_detach_hook ();
}

void 
interrupt_target_1 (int all_threads)
{
  ptid_t ptid;
  if (all_threads)
    ptid = minus_one_ptid;
  else
    ptid = inferior_ptid;
  target_stop (ptid);
}

/* Stop the execution of the target while running in async mode, in
   the backgound.  In all-stop, stop the whole process.  In non-stop
   mode, stop the current thread only by default, or stop all threads
   if the `-a' switch is used.  */

/* interrupt [-a]  */
void
interrupt_target_command (char *args, int from_tty)
{
  if (target_can_async_p ())
    {
      int all_threads = 0;

      dont_repeat ();           /* Not for the faint of heart */

      if (args != NULL
          && strncmp (args, "-a", sizeof ("-a") - 1) == 0)
        all_threads = 1;

      if (!non_stop && all_threads)
        error (_("-a is meaningless in all-stop mode."));

      interrupt_target_1 (all_threads);
    }
}

static void
print_float_info (struct gdbarch *gdbarch, struct ui_file *file,
                  struct frame_info *frame, const char *args)
{
  if (gdbarch_print_float_info_p (gdbarch))
    gdbarch_print_float_info (gdbarch, file, frame, args);
  else
    {
      int regnum;
      int printed_something = 0;

      for (regnum = 0;
           regnum < gdbarch_num_regs (gdbarch)
                    + gdbarch_num_pseudo_regs (gdbarch);
           regnum++)
        {
          if (gdbarch_register_reggroup_p (gdbarch, regnum, float_reggroup))
            {
              printed_something = 1;
              gdbarch_print_registers_info (gdbarch, file, frame, regnum, 1);
            }
        }
      if (!printed_something)
        fprintf_filtered (file, "\
No floating-point info available for this processor.\n");
    }
}

static void
float_info (char *args, int from_tty)
{
  if (!target_has_registers)
    error (_("The program has no registers now."));

  print_float_info (current_gdbarch, gdb_stdout, 
                    get_selected_frame (NULL), args);
}
\f
static void
unset_command (char *args, int from_tty)
{
  printf_filtered (_("\
\"unset\" must be followed by the name of an unset subcommand.\n"));
  help_list (unsetlist, "unset ", -1, gdb_stdout);
}

void
_initialize_infcmd (void)
{
  struct cmd_list_element *c = NULL;

  /* add the filename of the terminal connected to inferior I/O */
  add_setshow_filename_cmd ("inferior-tty", class_run,
                            &inferior_io_terminal, _("\
Set terminal for future runs of program being debugged."), _("\
Show terminal for future runs of program being debugged."), _("\
Usage: set inferior-tty /dev/pts/1"), NULL, NULL, &setlist, &showlist);
  add_com_alias ("tty", "set inferior-tty", class_alias, 0);

  add_setshow_optional_filename_cmd ("args", class_run,
                                     &inferior_args, _("\
Set argument list to give program being debugged when it is started."), _("\
Show argument list to give program being debugged when it is started."), _("\
Follow this command with any number of args, to be passed to the program."),
                                     notice_args_set,
                                     notice_args_read,
                                     &setlist, &showlist);

  c = add_cmd ("environment", no_class, environment_info, _("\
The environment to give the program, or one variable's value.\n\
With an argument VAR, prints the value of environment variable VAR to\n\
give the program being debugged.  With no arguments, prints the entire\n\
environment to be given to the program."), &showlist);
  set_cmd_completer (c, noop_completer);

  add_prefix_cmd ("unset", no_class, unset_command,
                  _("Complement to certain \"set\" commands."),
                  &unsetlist, "unset ", 0, &cmdlist);

  c = add_cmd ("environment", class_run, unset_environment_command, _("\
Cancel environment variable VAR for the program.\n\
This does not affect the program until the next \"run\" command."),
               &unsetlist);
  set_cmd_completer (c, noop_completer);

  c = add_cmd ("environment", class_run, set_environment_command, _("\
Set environment variable value to give the program.\n\
Arguments are VAR VALUE where VAR is variable name and VALUE is value.\n\
VALUES of environment variables are uninterpreted strings.\n\
This does not affect the program until the next \"run\" command."),
               &setlist);
  set_cmd_completer (c, noop_completer);

  c = add_com ("path", class_files, path_command, _("\
Add directory DIR(s) to beginning of search path for object files.\n\
$cwd in the path means the current working directory.\n\
This path is equivalent to the $PATH shell variable.  It is a list of\n\
directories, separated by colons.  These directories are searched to find\n\
fully linked executable files and separately compiled object files as needed."));
  set_cmd_completer (c, filename_completer);

  c = add_cmd ("paths", no_class, path_info, _("\
Current search path for finding object files.\n\
$cwd in the path means the current working directory.\n\
This path is equivalent to the $PATH shell variable.  It is a list of\n\
directories, separated by colons.  These directories are searched to find\n\
fully linked executable files and separately compiled object files as needed."),
               &showlist);
  set_cmd_completer (c, noop_completer);

  add_com ("attach", class_run, attach_command, _("\
Attach to a process or file outside of GDB.\n\
This command attaches to another target, of the same type as your last\n\
\"target\" command (\"info files\" will show your target stack).\n\
The command may take as argument a process id or a device file.\n\
For a process id, you must have permission to send the process a signal,\n\
and it must have the same effective uid as the debugger.\n\
When using \"attach\" with a process id, the debugger finds the\n\
program running in the process, looking first in the current working\n\
directory, or (if not found there) using the source file search path\n\
(see the \"directory\" command).  You can also use the \"file\" command\n\
to specify the program, and to load its symbol table."));

  add_prefix_cmd ("detach", class_run, detach_command, _("\
Detach a process or file previously attached.\n\
If a process, it is no longer traced, and it continues its execution.  If\n\
you were debugging a file, the file is closed and gdb no longer accesses it."),
                  &detachlist, "detach ", 0, &cmdlist);

  add_com ("disconnect", class_run, disconnect_command, _("\
Disconnect from a target.\n\
The target will wait for another debugger to connect.  Not available for\n\
all targets."));

  add_com ("signal", class_run, signal_command, _("\
Continue program giving it signal specified by the argument.\n\
An argument of \"0\" means continue program without giving it a signal."));

  add_com ("stepi", class_run, stepi_command, _("\
Step one instruction exactly.\n\
Argument N means do this N times (or till program stops for another reason)."));
  add_com_alias ("si", "stepi", class_alias, 0);

  add_com ("nexti", class_run, nexti_command, _("\
Step one instruction, but proceed through subroutine calls.\n\
Argument N means do this N times (or till program stops for another reason)."));
  add_com_alias ("ni", "nexti", class_alias, 0);

  add_com ("finish", class_run, finish_command, _("\
Execute until selected stack frame returns.\n\
Upon return, the value returned is printed and put in the value history."));
  add_com_alias ("fin", "finish", class_run, 1);

  add_com ("next", class_run, next_command, _("\
Step program, proceeding through subroutine calls.\n\
Like the \"step\" command as long as subroutine calls do not happen;\n\
when they do, the call is treated as one instruction.\n\
Argument N means do this N times (or till program stops for another reason)."));
  add_com_alias ("n", "next", class_run, 1);
  if (xdb_commands)
    add_com_alias ("S", "next", class_run, 1);

  add_com ("step", class_run, step_command, _("\
Step program until it reaches a different source line.\n\
Argument N means do this N times (or till program stops for another reason)."));
  add_com_alias ("s", "step", class_run, 1);

  c = add_com ("until", class_run, until_command, _("\
Execute until the program reaches a source line greater than the current\n\
or a specified location (same args as break command) within the current frame."));
  set_cmd_completer (c, location_completer);
  add_com_alias ("u", "until", class_run, 1);

  c = add_com ("advance", class_run, advance_command, _("\
Continue the program up to the given location (same form as args for break command).\n\
Execution will also stop upon exit from the current stack frame."));
  set_cmd_completer (c, location_completer);

  c = add_com ("jump", class_run, jump_command, _("\
Continue program being debugged at specified line or address.\n\
Give as argument either LINENUM or *ADDR, where ADDR is an expression\n\
for an address to start at."));
  set_cmd_completer (c, location_completer);

  if (xdb_commands)
    {
      c = add_com ("go", class_run, go_command, _("\
Usage: go <location>\n\
Continue program being debugged, stopping at specified line or \n\
address.\n\
Give as argument either LINENUM or *ADDR, where ADDR is an \n\
expression for an address to start at.\n\
This command is a combination of tbreak and jump."));
      set_cmd_completer (c, location_completer);
    }

  if (xdb_commands)
    add_com_alias ("g", "go", class_run, 1);

  c = add_com ("continue", class_run, continue_command, _("\
Continue program being debugged, after signal or breakpoint.\n\
If proceeding from breakpoint, a number N may be used as an argument,\n\
which means to set the ignore count of that breakpoint to N - 1 (so that\n\
the breakpoint won't break until the Nth time it is reached).\n\
\n\
If non-stop mode is enabled, continue only the current thread,\n\
otherwise all the threads in the program are continued.  To \n\
continue all stopped threads in non-stop mode, use the -a option.\n\
Specifying -a and an ignore count simultaneously is an error."));
  add_com_alias ("c", "cont", class_run, 1);
  add_com_alias ("fg", "cont", class_run, 1);

  c = add_com ("run", class_run, run_command, _("\
Start debugged program.  You may specify arguments to give it.\n\
Args may include \"*\", or \"[...]\"; they are expanded using \"sh\".\n\
Input and output redirection with \">\", \"<\", or \">>\" are also allowed.\n\n\
With no arguments, uses arguments last specified (with \"run\" or \"set args\").\n\
To cancel previous arguments and run with no arguments,\n\
use \"set args\" without arguments."));
  set_cmd_completer (c, filename_completer);
  add_com_alias ("r", "run", class_run, 1);
  if (xdb_commands)
    add_com ("R", class_run, run_no_args_command,
             _("Start debugged program with no arguments."));

  c = add_com ("start", class_run, start_command, _("\
Run the debugged program until the beginning of the main procedure.\n\
You may specify arguments to give to your program, just as with the\n\
\"run\" command."));
  set_cmd_completer (c, filename_completer);

  c = add_com ("interrupt", class_run, interrupt_target_command,
               _("Interrupt the execution of the debugged program.\n\
If non-stop mode is enabled, interrupt only the current thread,\n\
otherwise all the threads in the program are stopped.  To \n\
interrupt all running threads in non-stop mode, use the -a option."));

  add_info ("registers", nofp_registers_info, _("\
List of integer registers and their contents, for selected stack frame.\n\
Register name as argument means describe only that register."));
  add_info_alias ("r", "registers", 1);

  if (xdb_commands)
    add_com ("lr", class_info, nofp_registers_info, _("\
List of integer registers and their contents, for selected stack frame.\n\
Register name as argument means describe only that register."));
  add_info ("all-registers", all_registers_info, _("\
List of all registers and their contents, for selected stack frame.\n\
Register name as argument means describe only that register."));

  add_info ("program", program_info,
            _("Execution status of the program."));

  add_info ("float", float_info,
            _("Print the status of the floating point unit\n"));

  add_info ("vector", vector_info,
            _("Print the status of the vector unit\n"));

  inferior_environ = make_environ ();
  init_environ (inferior_environ);
}