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/* Low level interface to ptrace, for GDB when running under Unix.

   Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,

   1996, 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 "frame.h"

#include "inferior.h"

#include "command.h"

#include "serial.h"

#include "terminal.h"

#include "target.h"

#include "gdbthread.h"

#include "gdb_string.h"

#include <signal.h>

#include <fcntl.h>

#include "gdb_select.h"

#include "inflow.h"

#ifdef HAVE_SYS_IOCTL_H

#include <sys/ioctl.h>

#endif

#ifndef O_NOCTTY

#define O_NOCTTY 0

#endif

#if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)

static void handle_sigio (int);

#endif

extern void _initialize_inflow (void);

static void pass_signal (int);

static void kill_command (char *, int);

static void terminal_ours_1 (int);

/* Record terminal status separately for debugger and inferior.  */

static struct serial *stdin_serial;

/* TTY state for the inferior.  We save it whenever the inferior stops, and

   restore it when it resumes.  */

static serial_ttystate inferior_ttystate;

/* Our own tty state, which we restore every time we need to deal with the

   terminal.  We only set it once, when GDB first starts.  The settings of

   flags which readline saves and restores and unimportant.  */

static serial_ttystate our_ttystate;

/* fcntl flags for us and the inferior.  Saved and restored just like

   {our,inferior}_ttystate.  */

static int tflags_inferior;

static int tflags_ours;

#ifdef PROCESS_GROUP_TYPE

/* Process group for us and the inferior.  Saved and restored just like

   {our,inferior}_ttystate.  */

PROCESS_GROUP_TYPE our_process_group;

PROCESS_GROUP_TYPE inferior_process_group;

#endif

/* While the inferior is running, we want SIGINT and SIGQUIT to go to the

   inferior only.  If we have job control, that takes care of it.  If not,

   we save our handlers in these two variables and set SIGINT and SIGQUIT

   to SIG_IGN.  */

static void (*sigint_ours) ();

static void (*sigquit_ours) ();

/* The name of the tty (from the `tty' command) that we gave to the inferior

   when it was last started.  */

static const char *inferior_thisrun_terminal;

/* Nonzero if our terminal settings are in effect.  Zero if the

   inferior's settings are in effect.  Ignored if !gdb_has_a_terminal

   ().  */

int terminal_is_ours;

enum

  {

    yes, no, have_not_checked

  }

gdb_has_a_terminal_flag = have_not_checked;

/* Does GDB have a terminal (on stdin)?  */

int

gdb_has_a_terminal (void)

{

  switch (gdb_has_a_terminal_flag)

    {

    case yes:

      return 1;

    case no:

      return 0;

    case have_not_checked:

      /* Get all the current tty settings (including whether we have a

         tty at all!).  Can't do this in _initialize_inflow because

         serial_fdopen() won't work until the serial_ops_list is

         initialized.  */

#ifdef F_GETFL

      tflags_ours = fcntl (0, F_GETFL, 0);

#endif

      gdb_has_a_terminal_flag = no;

      if (stdin_serial != NULL)

        {

          our_ttystate = serial_get_tty_state (stdin_serial);

          if (our_ttystate != NULL)

            {

              gdb_has_a_terminal_flag = yes;

#ifdef HAVE_TERMIOS

              our_process_group = tcgetpgrp (0);

#endif

#ifdef HAVE_TERMIO

              our_process_group = getpgrp ();

#endif

#ifdef HAVE_SGTTY

              ioctl (0, TIOCGPGRP, &our_process_group);

#endif

            }

        }

      return gdb_has_a_terminal_flag == yes;

    default:

      /* "Can't happen".  */

      return 0;

    }

}

/* Macro for printing errors from ioctl operations */

#define OOPSY(what)     \

  if (result == -1)     \

    fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \

            what, safe_strerror (errno))

static void terminal_ours_1 (int);

/* Initialize the terminal settings we record for the inferior,

   before we actually run the inferior.  */

void

terminal_init_inferior_with_pgrp (int pgrp)

{

  if (gdb_has_a_terminal ())

    {

      /* We could just as well copy our_ttystate (if we felt like

         adding a new function serial_copy_tty_state()).  */

      if (inferior_ttystate)

        xfree (inferior_ttystate);

      inferior_ttystate = serial_get_tty_state (stdin_serial);

#ifdef PROCESS_GROUP_TYPE

      inferior_process_group = pgrp;

#endif

      /* Make sure that next time we call terminal_inferior (which will be

         before the program runs, as it needs to be), we install the new

         process group.  */

      terminal_is_ours = 1;

    }

}

/* Save the terminal settings again.  This is necessary for the TUI

   when it switches to TUI or non-TUI mode;  curses changes the terminal

   and gdb must be able to restore it correctly.  */

void

terminal_save_ours (void)

{

  if (gdb_has_a_terminal ())

    {

      /* We could just as well copy our_ttystate (if we felt like adding

         a new function serial_copy_tty_state).  */

      if (our_ttystate)

        xfree (our_ttystate);

      our_ttystate = serial_get_tty_state (stdin_serial);

    }

}

void

terminal_init_inferior (void)

{

#ifdef PROCESS_GROUP_TYPE

  /* This is for Lynx, and should be cleaned up by having Lynx be a separate

     debugging target with a version of target_terminal_init_inferior which

     passes in the process group to a generic routine which does all the work

     (and the non-threaded child_terminal_init_inferior can just pass in

     inferior_ptid to the same routine).  */

  /* We assume INFERIOR_PID is also the child's process group.  */

  terminal_init_inferior_with_pgrp (PIDGET (inferior_ptid));

#endif /* PROCESS_GROUP_TYPE */

}

/* Put the inferior's terminal settings into effect.

   This is preparation for starting or resuming the inferior.  */

void

terminal_inferior (void)

{

  if (gdb_has_a_terminal () && terminal_is_ours

      && inferior_ttystate != NULL

      && inferior_thisrun_terminal == 0)

    {

      int result;

#ifdef F_GETFL

      /* Is there a reason this is being done twice?  It happens both

         places we use F_SETFL, so I'm inclined to think perhaps there

         is some reason, however perverse.  Perhaps not though...  */

      result = fcntl (0, F_SETFL, tflags_inferior);

      result = fcntl (0, F_SETFL, tflags_inferior);

      OOPSY ("fcntl F_SETFL");

#endif

      /* Because we were careful to not change in or out of raw mode in

         terminal_ours, we will not change in our out of raw mode with

         this call, so we don't flush any input.  */

      result = serial_set_tty_state (stdin_serial, inferior_ttystate);

      OOPSY ("setting tty state");

      if (!job_control)

        {

          sigint_ours = (void (*)()) signal (SIGINT, SIG_IGN);

#ifdef SIGQUIT

          sigquit_ours = (void (*)()) signal (SIGQUIT, SIG_IGN);

#endif

        }

      /* If attach_flag is set, we don't know whether we are sharing a

         terminal with the inferior or not.  (attaching a process

         without a terminal is one case where we do not; attaching a

         process which we ran from the same shell as GDB via `&' is

         one case where we do, I think (but perhaps this is not

         `sharing' in the sense that we need to save and restore tty

         state)).  I don't know if there is any way to tell whether we

         are sharing a terminal.  So what we do is to go through all

         the saving and restoring of the tty state, but ignore errors

         setting the process group, which will happen if we are not

         sharing a terminal).  */

      if (job_control)

        {

#ifdef HAVE_TERMIOS

          result = tcsetpgrp (0, inferior_process_group);

          if (!attach_flag)

            OOPSY ("tcsetpgrp");

#endif

#ifdef HAVE_SGTTY

          result = ioctl (0, TIOCSPGRP, &inferior_process_group);

          if (!attach_flag)

            OOPSY ("TIOCSPGRP");

#endif

        }

    }

  terminal_is_ours = 0;

}

/* Put some of our terminal settings into effect,

   enough to get proper results from our output,

   but do not change into or out of RAW mode

   so that no input is discarded.

   After doing this, either terminal_ours or terminal_inferior

   should be called to get back to a normal state of affairs.  */

void

terminal_ours_for_output (void)

{

  terminal_ours_1 (1);

}

/* Put our terminal settings into effect.

   First record the inferior's terminal settings

   so they can be restored properly later.  */

void

terminal_ours (void)

{

  terminal_ours_1 (0);

}

/* output_only is not used, and should not be used unless we introduce

   separate terminal_is_ours and terminal_is_ours_for_output

   flags.  */

static void

terminal_ours_1 (int output_only)

{

  /* Checking inferior_thisrun_terminal is necessary so that

     if GDB is running in the background, it won't block trying

     to do the ioctl()'s below.  Checking gdb_has_a_terminal

     avoids attempting all the ioctl's when running in batch.  */

  if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)

    return;

  if (!terminal_is_ours)

    {

#ifdef SIGTTOU

      /* Ignore this signal since it will happen when we try to set the

         pgrp.  */

      void (*osigttou) () = NULL;

#endif

      int result;

      terminal_is_ours = 1;

#ifdef SIGTTOU

      if (job_control)

        osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);

#endif

      if (inferior_ttystate)

        xfree (inferior_ttystate);

      inferior_ttystate = serial_get_tty_state (stdin_serial);

#ifdef HAVE_TERMIOS

      inferior_process_group = tcgetpgrp (0);

#endif

#ifdef HAVE_TERMIO

      inferior_process_group = getpgrp ();

#endif

#ifdef HAVE_SGTTY

      ioctl (0, TIOCGPGRP, &inferior_process_group);

#endif

      /* Here we used to set ICANON in our ttystate, but I believe this

         was an artifact from before when we used readline.  Readline sets

         the tty state when it needs to.

         FIXME-maybe: However, query() expects non-raw mode and doesn't

         use readline.  Maybe query should use readline (on the other hand,

         this only matters for HAVE_SGTTY, not termio or termios, I think).  */

      /* Set tty state to our_ttystate.  We don't change in our out of raw

         mode, to avoid flushing input.  We need to do the same thing

         regardless of output_only, because we don't have separate

         terminal_is_ours and terminal_is_ours_for_output flags.  It's OK,

         though, since readline will deal with raw mode when/if it needs to.

       */

      serial_noflush_set_tty_state (stdin_serial, our_ttystate,

                                    inferior_ttystate);

      if (job_control)

        {

#ifdef HAVE_TERMIOS

          result = tcsetpgrp (0, our_process_group);

#if 0

          /* This fails on Ultrix with EINVAL if you run the testsuite

             in the background with nohup, and then log out.  GDB never

             used to check for an error here, so perhaps there are other

             such situations as well.  */

          if (result == -1)

            fprintf_unfiltered (gdb_stderr, "[tcsetpgrp failed in terminal_ours: %s]\n",

                                safe_strerror (errno));

#endif

#endif /* termios */

#ifdef HAVE_SGTTY

          result = ioctl (0, TIOCSPGRP, &our_process_group);

#endif

        }

#ifdef SIGTTOU

      if (job_control)

        signal (SIGTTOU, osigttou);

#endif

      if (!job_control)

        {

          signal (SIGINT, sigint_ours);

#ifdef SIGQUIT

          signal (SIGQUIT, sigquit_ours);

#endif

        }

#ifdef F_GETFL

      tflags_inferior = fcntl (0, F_GETFL, 0);

      /* Is there a reason this is being done twice?  It happens both

         places we use F_SETFL, so I'm inclined to think perhaps there

         is some reason, however perverse.  Perhaps not though...  */

      result = fcntl (0, F_SETFL, tflags_ours);

      result = fcntl (0, F_SETFL, tflags_ours);

#endif

    }

}

void

term_info (char *arg, int from_tty)

{

  target_terminal_info (arg, from_tty);

}

void

child_terminal_info (char *args, int from_tty)

{

  if (!gdb_has_a_terminal ())

    {

      printf_filtered (_("This GDB does not control a terminal.\n"));

      return;

    }

  printf_filtered (_("Inferior's terminal status (currently saved by GDB):\n"));

  /* First the fcntl flags.  */

  {

    int flags;

    flags = tflags_inferior;

    printf_filtered ("File descriptor flags = ");

#ifndef O_ACCMODE

#define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)

#endif

    /* (O_ACCMODE) parens are to avoid Ultrix header file bug */

    switch (flags & (O_ACCMODE))

      {

      case O_RDONLY:

        printf_filtered ("O_RDONLY");

        break;

      case O_WRONLY:

        printf_filtered ("O_WRONLY");

        break;

      case O_RDWR:

        printf_filtered ("O_RDWR");

        break;

      }

    flags &= ~(O_ACCMODE);

#ifdef O_NONBLOCK

    if (flags & O_NONBLOCK)

      printf_filtered (" | O_NONBLOCK");

    flags &= ~O_NONBLOCK;

#endif

#if defined (O_NDELAY)

    /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will

       print it as O_NONBLOCK, which is good cause that is what POSIX

       has, and the flag will already be cleared by the time we get here.  */

    if (flags & O_NDELAY)

      printf_filtered (" | O_NDELAY");

    flags &= ~O_NDELAY;

#endif

    if (flags & O_APPEND)

      printf_filtered (" | O_APPEND");

    flags &= ~O_APPEND;

#if defined (O_BINARY)

    if (flags & O_BINARY)

      printf_filtered (" | O_BINARY");

    flags &= ~O_BINARY;

#endif

    if (flags)

      printf_filtered (" | 0x%x", flags);

    printf_filtered ("\n");

  }

#ifdef PROCESS_GROUP_TYPE

  printf_filtered ("Process group = %d\n",

                   (int) inferior_process_group);

#endif

  serial_print_tty_state (stdin_serial, inferior_ttystate, gdb_stdout);

}

/* NEW_TTY_PREFORK is called before forking a new child process,

   so we can record the state of ttys in the child to be formed.

   TTYNAME is null if we are to share the terminal with gdb;

   or points to a string containing the name of the desired tty.

   NEW_TTY is called in new child processes under Unix, which will

   become debugger target processes.  This actually switches to

   the terminal specified in the NEW_TTY_PREFORK call.  */

void

new_tty_prefork (const char *ttyname)

{

  /* Save the name for later, for determining whether we and the child

     are sharing a tty.  */

  inferior_thisrun_terminal = ttyname;

}

void

new_tty (void)

{

  int tty;

  if (inferior_thisrun_terminal == 0)

    return;

#if !defined(__GO32__) && !defined(_WIN32)

#ifdef TIOCNOTTY

  /* Disconnect the child process from our controlling terminal.  On some

     systems (SVR4 for example), this may cause a SIGTTOU, so temporarily

     ignore SIGTTOU. */

  tty = open ("/dev/tty", O_RDWR);

  if (tty > 0)

    {

      void (*osigttou) ();

      osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);

      ioctl (tty, TIOCNOTTY, 0);

      close (tty);

      signal (SIGTTOU, osigttou);

    }

#endif

  /* Now open the specified new terminal.  */

  tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY);

  if (tty == -1)

    {

      print_sys_errmsg (inferior_thisrun_terminal, errno);

      _exit (1);

    }

  /* Avoid use of dup2; doesn't exist on all systems.  */

  if (tty != 0)

    {

      close (0);

      dup (tty);

    }

  if (tty != 1)

    {

      close (1);

      dup (tty);

    }

  if (tty != 2)

    {

      close (2);

      dup (tty);

    }

  if (tty > 2)

    close (tty);

#endif /* !go32 && !win32 */

}

/* Kill the inferior process.  Make us have no inferior.  */

static void

kill_command (char *arg, int from_tty)

{

  /* FIXME:  This should not really be inferior_ptid (or target_has_execution).

     It should be a distinct flag that indicates that a target is active, cuz

     some targets don't have processes! */

  if (ptid_equal (inferior_ptid, null_ptid))

    error (_("The program is not being run."));

  if (!query ("Kill the program being debugged? "))

    error (_("Not confirmed."));

  target_kill ();

  init_thread_list ();          /* Destroy thread info */

  /* Killing off the inferior can leave us with a core file.  If so,

     print the state we are left in.  */

  if (target_has_stack)

    {

      printf_filtered (_("In %s,\n"), target_longname);

      print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);

    }

  bfd_cache_close_all ();

}

/* Call set_sigint_trap when you need to pass a signal on to an attached

   process when handling SIGINT */

static void

pass_signal (int signo)

{

#ifndef _WIN32

  kill (PIDGET (inferior_ptid), SIGINT);

#endif

}

static void (*osig) ();

void

set_sigint_trap (void)

{

  if (attach_flag || inferior_thisrun_terminal)

    {

      osig = (void (*)()) signal (SIGINT, pass_signal);

    }

}

void

clear_sigint_trap (void)

{

  if (attach_flag || inferior_thisrun_terminal)

    {

      signal (SIGINT, osig);

    }

}

#if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)

static void (*old_sigio) ();

static void

handle_sigio (int signo)

{

  int numfds;

  fd_set readfds;

  signal (SIGIO, handle_sigio);

  FD_ZERO (&readfds);

  FD_SET (target_activity_fd, &readfds);

  numfds = gdb_select (target_activity_fd + 1, &readfds, NULL, NULL, NULL);

  if (numfds >= 0 && FD_ISSET (target_activity_fd, &readfds))

    {

#ifndef _WIN32

      if ((*target_activity_function) ())

        kill (PIDGET (inferior_ptid), SIGINT);

#endif

    }

}

static int old_fcntl_flags;

void

set_sigio_trap (void)

{

  if (target_activity_function)

    {

      old_sigio = (void (*)()) signal (SIGIO, handle_sigio);

      fcntl (target_activity_fd, F_SETOWN, getpid ());

      old_fcntl_flags = fcntl (target_activity_fd, F_GETFL, 0);

      fcntl (target_activity_fd, F_SETFL, old_fcntl_flags | FASYNC);

    }

}

void

clear_sigio_trap (void)

{

  if (target_activity_function)

    {

      signal (SIGIO, old_sigio);

      fcntl (target_activity_fd, F_SETFL, old_fcntl_flags);

    }

}

#else /* No SIGIO.  */

void

set_sigio_trap (void)

{

  if (target_activity_function)

    internal_error (__FILE__, __LINE__, _("failed internal consistency check"));

}

void

clear_sigio_trap (void)

{

  if (target_activity_function)

    internal_error (__FILE__, __LINE__, _("failed internal consistency check"));

}

#endif /* No SIGIO.  */

/* This is here because this is where we figure out whether we (probably)

   have job control.  Just using job_control only does part of it because

   setpgid or setpgrp might not exist on a system without job control.

   It might be considered misplaced (on the other hand, process groups and

   job control are closely related to ttys).

   For a more clean implementation, in libiberty, put a setpgid which merely

   calls setpgrp and a setpgrp which does nothing (any system with job control

   will have one or the other).  */

int

gdb_setpgid (void)

{

  int retval = 0;

  if (job_control)

    {

#if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)

#ifdef HAVE_SETPGID

      /* The call setpgid (0, 0) is supposed to work and mean the same

         thing as this, but on Ultrix 4.2A it fails with EPERM (and

         setpgid (getpid (), getpid ()) succeeds).  */

      retval = setpgid (getpid (), getpid ());

#else

#ifdef HAVE_SETPGRP

#ifdef SETPGRP_VOID 

      retval = setpgrp ();

#else

      retval = setpgrp (getpid (), getpid ());

#endif

#endif /* HAVE_SETPGRP */

#endif /* HAVE_SETPGID */

#endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */

    }

  return retval;

}

/* Get all the current tty settings (including whether we have a

   tty at all!).  We can't do this in _initialize_inflow because

   serial_fdopen() won't work until the serial_ops_list is

   initialized, but we don't want to do it lazily either, so

   that we can guarantee stdin_serial is opened if there is

   a terminal.  */

void

initialize_stdin_serial (void)

{

  stdin_serial = serial_fdopen (0);

}

void

_initialize_inflow (void)

{

  add_info ("terminal", term_info,

            _("Print inferior's saved terminal status."));

  add_com ("kill", class_run, kill_command,

           _("Kill execution of program being debugged."));

  inferior_ptid = null_ptid;