523 lines
14 KiB
C
523 lines
14 KiB
C
/* Low level interface to ptrace, for GDB when running under Unix.
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Copyright 1986, 1987, 1989, 1991, 1992 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "defs.h"
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#include "frame.h"
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#include "inferior.h"
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#include "command.h"
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#include "signals.h"
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#include "serial.h"
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#include "target.h"
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#ifdef USG
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#include <sys/types.h>
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#endif
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/* Some USG-esque systems (some of which are BSD-esque enough so that USG
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is not defined) want this header, and it won't do any harm. */
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#include <fcntl.h>
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#include <sys/param.h>
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#include <signal.h>
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static void
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kill_command PARAMS ((char *, int));
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static void
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terminal_ours_1 PARAMS ((int));
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/* Nonzero if we are debugging an attached outside process
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rather than an inferior. */
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int attach_flag;
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/* Record terminal status separately for debugger and inferior. */
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static serial_t stdin_serial;
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/* TTY state for the inferior. We save it whenever the inferior stops, and
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restore it when it resumes. */
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static serial_ttystate inferior_ttystate;
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/* Our own tty state, which we restore every time we need to deal with the
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terminal. We only set it once, when GDB first starts. The settings of
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flags which readline saves and restores and unimportant. */
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static serial_ttystate our_ttystate;
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/* fcntl flags for us and the inferior. Saved and restored just like
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{our,inferior}_ttystate. */
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static int tflags_inferior;
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static int tflags_ours;
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/* While the inferior is running, we want SIGINT and SIGQUIT to go to the
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inferior only. If we have job control, that takes care of it. If not,
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we save our handlers in these two variables and set SIGINT and SIGQUIT
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to SIG_IGN. */
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static void (*sigint_ours) ();
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static void (*sigquit_ours) ();
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/* The name of the tty (from the `tty' command) that we gave to the inferior
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when it was last started. */
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static char *inferior_thisrun_terminal;
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/* Nonzero if our terminal settings are in effect.
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Zero if the inferior's settings are in effect. */
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static int terminal_is_ours;
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enum {yes, no, have_not_checked} gdb_has_a_terminal_flag = have_not_checked;
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/* Does GDB have a terminal (on stdin)? */
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int
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gdb_has_a_terminal ()
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{
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switch (gdb_has_a_terminal_flag)
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{
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case yes:
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return 1;
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case no:
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return 0;
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case have_not_checked:
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/* Get all the current tty settings (including whether we have a tty at
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all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
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won't work until the serial_ops_list is initialized. */
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tflags_ours = fcntl (0, F_GETFL, 0);
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gdb_has_a_terminal_flag = no;
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stdin_serial = SERIAL_FDOPEN (0);
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if (stdin_serial != NULL)
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{
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our_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
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if (our_ttystate != NULL)
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gdb_has_a_terminal_flag = yes;
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}
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return gdb_has_a_terminal_flag == yes;
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}
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}
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/* Macro for printing errors from ioctl operations */
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#define OOPSY(what) \
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if (result == -1) \
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fprintf(stderr, "[%s failed in terminal_inferior: %s]\n", \
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what, strerror (errno))
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static void terminal_ours_1 PARAMS ((int));
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/* Initialize the terminal settings we record for the inferior,
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before we actually run the inferior. */
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void
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terminal_init_inferior ()
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{
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/* Make sure that our_ttystate (etc) are initialized. */
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gdb_has_a_terminal ();
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/* We could just as well copy our_ttystate (if we felt like adding
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a new function SERIAL_COPY_TTY_STATE). */
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if (inferior_ttystate)
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free (inferior_ttystate);
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inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
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SERIAL_SET_PROCESS_GROUP (stdin_serial, inferior_ttystate, inferior_pid);
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/* Make sure that next time we call terminal_inferior (which will be
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before the program runs, as it needs to be), we install the new
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process group. */
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terminal_is_ours = 1;
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}
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/* Put the inferior's terminal settings into effect.
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This is preparation for starting or resuming the inferior. */
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void
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terminal_inferior ()
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{
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if (gdb_has_a_terminal () && terminal_is_ours
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&& inferior_thisrun_terminal == 0)
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{
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int result;
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/* Is there a reason this is being done twice? It happens both
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places we use F_SETFL, so I'm inclined to think perhaps there
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is some reason, however perverse. Perhaps not though... */
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result = fcntl (0, F_SETFL, tflags_inferior);
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result = fcntl (0, F_SETFL, tflags_inferior);
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OOPSY ("fcntl F_SETFL");
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/* Because we were careful to not change in or out of raw mode in
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terminal_ours, we will not change in our out of raw mode with
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this call, so we don't flush any input. */
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result = SERIAL_SET_TTY_STATE (stdin_serial, inferior_ttystate);
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/* If attach_flag is set, we don't know whether we are sharing a
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terminal with the inferior or not. (attaching a process
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without a terminal is one case where we do not; attaching a
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process which we ran from the same shell as GDB via `&' is
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one case where we do, I think (but perhaps this is not
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`sharing' in the sense that we need to save and restore tty
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state)). I don't know if there is any way to tell whether we
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are sharing a terminal. So what we do is to go through all
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the saving and restoring of terminal state, but ignore errors
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(which will occur, in tcsetpgrp, if we are not sharing a
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terminal). */
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if (!attach_flag)
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OOPSY ("setting tty state");
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if (!job_control)
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{
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sigint_ours = (void (*) ()) signal (SIGINT, SIG_IGN);
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sigquit_ours = (void (*) ()) signal (SIGQUIT, SIG_IGN);
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}
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}
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terminal_is_ours = 0;
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}
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/* Put some of our terminal settings into effect,
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enough to get proper results from our output,
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but do not change into or out of RAW mode
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so that no input is discarded.
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After doing this, either terminal_ours or terminal_inferior
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should be called to get back to a normal state of affairs. */
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void
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terminal_ours_for_output ()
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{
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terminal_ours_1 (1);
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}
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/* Put our terminal settings into effect.
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First record the inferior's terminal settings
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so they can be restored properly later. */
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void
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terminal_ours ()
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{
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terminal_ours_1 (0);
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}
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/* output_only is not used, and should not be used unless we introduce
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separate terminal_is_ours and terminal_is_ours_for_output
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flags. */
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static void
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terminal_ours_1 (output_only)
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int output_only;
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{
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/* Checking inferior_thisrun_terminal is necessary so that
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if GDB is running in the background, it won't block trying
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to do the ioctl()'s below. Checking gdb_has_a_terminal
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avoids attempting all the ioctl's when running in batch. */
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if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)
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return;
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if (!terminal_is_ours)
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{
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/* Ignore this signal since it will happen when we try to set the
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pgrp. */
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void (*osigttou) ();
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int result;
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terminal_is_ours = 1;
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#ifdef SIGTTOU
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if (job_control)
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osigttou = (void (*) ()) signal (SIGTTOU, SIG_IGN);
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#endif
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if (inferior_ttystate)
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free (inferior_ttystate);
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inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
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/* Here we used to set ICANON in our ttystate, but I believe this
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was an artifact from before when we used readline. Readline sets
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the tty state when it needs to. */
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/* Set tty state to our_ttystate. We don't change in our out of raw
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mode, to avoid flushing input. We need to do the same thing
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regardless of output_only, because we don't have separate
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terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
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though, since readline will deal with raw mode when/if it needs to.
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*/
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SERIAL_NOFLUSH_SET_TTY_STATE (stdin_serial, our_ttystate,
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inferior_ttystate);
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#ifdef SIGTTOU
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if (job_control)
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signal (SIGTTOU, osigttou);
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#endif
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if (!job_control)
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{
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signal (SIGINT, sigint_ours);
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signal (SIGQUIT, sigquit_ours);
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}
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tflags_inferior = fcntl (0, F_GETFL, 0);
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/* Is there a reason this is being done twice? It happens both
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places we use F_SETFL, so I'm inclined to think perhaps there
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is some reason, however perverse. Perhaps not though... */
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result = fcntl (0, F_SETFL, tflags_ours);
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result = fcntl (0, F_SETFL, tflags_ours);
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result = result; /* lint */
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}
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}
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/* ARGSUSED */
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void
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term_info (arg, from_tty)
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char *arg;
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int from_tty;
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{
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target_terminal_info (arg, from_tty);
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}
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/* ARGSUSED */
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void
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child_terminal_info (args, from_tty)
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char *args;
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int from_tty;
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{
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if (!gdb_has_a_terminal ())
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{
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printf_filtered ("This GDB does not control a terminal.\n");
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return;
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}
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printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
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/* First the fcntl flags. */
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{
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int flags;
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flags = tflags_inferior;
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printf_filtered ("File descriptor flags = ");
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#ifndef O_ACCMODE
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#define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
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#endif
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/* (O_ACCMODE) parens are to avoid Ultrix header file bug */
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switch (flags & (O_ACCMODE))
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{
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case O_RDONLY: printf_filtered ("O_RDONLY"); break;
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case O_WRONLY: printf_filtered ("O_WRONLY"); break;
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case O_RDWR: printf_filtered ("O_RDWR"); break;
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}
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flags &= ~(O_ACCMODE);
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#ifdef O_NONBLOCK
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if (flags & O_NONBLOCK)
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printf_filtered (" | O_NONBLOCK");
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flags &= ~O_NONBLOCK;
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#endif
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#if defined (O_NDELAY)
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/* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
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print it as O_NONBLOCK, which is good cause that is what POSIX
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has, and the flag will already be cleared by the time we get here. */
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if (flags & O_NDELAY)
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printf_filtered (" | O_NDELAY");
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flags &= ~O_NDELAY;
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#endif
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if (flags & O_APPEND)
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printf_filtered (" | O_APPEND");
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flags &= ~O_APPEND;
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#if defined (O_BINARY)
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if (flags & O_BINARY)
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printf_filtered (" | O_BINARY");
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flags &= ~O_BINARY;
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#endif
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if (flags)
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printf_filtered (" | 0x%x", flags);
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printf_filtered ("\n");
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}
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SERIAL_PRINT_TTY_STATE (stdin_serial, inferior_ttystate);
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}
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/* NEW_TTY_PREFORK is called before forking a new child process,
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so we can record the state of ttys in the child to be formed.
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TTYNAME is null if we are to share the terminal with gdb;
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or points to a string containing the name of the desired tty.
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NEW_TTY is called in new child processes under Unix, which will
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become debugger target processes. This actually switches to
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the terminal specified in the NEW_TTY_PREFORK call. */
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void
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new_tty_prefork (ttyname)
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char *ttyname;
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{
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/* Save the name for later, for determining whether we and the child
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are sharing a tty. */
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inferior_thisrun_terminal = ttyname;
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}
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void
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new_tty ()
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{
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register int tty;
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void (*osigttou) ();
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if (inferior_thisrun_terminal == 0)
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return;
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#if !defined(__GO32__)
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#ifdef TIOCNOTTY
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/* Disconnect the child process from our controlling terminal. On some
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systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
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ignore SIGTTOU. */
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tty = open("/dev/tty", O_RDWR);
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if (tty > 0)
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{
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osigttou = (void (*)()) signal(SIGTTOU, SIG_IGN);
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ioctl(tty, TIOCNOTTY, 0);
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close(tty);
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signal(SIGTTOU, osigttou);
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}
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#endif
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/* Now open the specified new terminal. */
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#ifdef USE_O_NOCTTY
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tty = open(inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
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#else
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tty = open(inferior_thisrun_terminal, O_RDWR);
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#endif
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if (tty == -1)
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{
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print_sys_errmsg (inferior_thisrun_terminal, errno);
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_exit(1);
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}
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/* Avoid use of dup2; doesn't exist on all systems. */
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if (tty != 0)
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{ close (0); dup (tty); }
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if (tty != 1)
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{ close (1); dup (tty); }
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if (tty != 2)
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{ close (2); dup (tty); }
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if (tty > 2)
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close(tty);
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#endif /* !go32 */
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}
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/* Kill the inferior process. Make us have no inferior. */
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/* ARGSUSED */
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static void
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kill_command (arg, from_tty)
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char *arg;
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int from_tty;
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{
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/* Shouldn't this be target_has_execution? FIXME. */
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if (inferior_pid == 0)
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error ("The program is not being run.");
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if (!query ("Kill the program being debugged? "))
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error ("Not confirmed.");
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target_kill ();
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/* Killing off the inferior can leave us with a core file. If so,
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print the state we are left in. */
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if (target_has_stack) {
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printf_filtered ("In %s,\n", current_target->to_longname);
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if (selected_frame == NULL)
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fputs_filtered ("No selected stack frame.\n", stdout);
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else
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print_stack_frame (selected_frame, selected_frame_level, 1);
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}
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}
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/* The inferior process has died. Long live the inferior! */
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void
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generic_mourn_inferior ()
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{
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inferior_pid = 0;
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attach_flag = 0;
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mark_breakpoints_out ();
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registers_changed ();
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#ifdef CLEAR_DEFERRED_STORES
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/* Delete any pending stores to the inferior... */
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CLEAR_DEFERRED_STORES;
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#endif
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reopen_exec_file ();
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if (target_has_stack) {
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set_current_frame ( create_new_frame (read_register (FP_REGNUM),
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read_pc ()));
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select_frame (get_current_frame (), 0);
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} else {
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set_current_frame (0);
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select_frame ((FRAME) 0, -1);
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}
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/* It is confusing to the user for ignore counts to stick around
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from previous runs of the inferior. So clear them. */
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breakpoint_clear_ignore_counts ();
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}
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/* Call set_sigint_trap when you need to pass a signal on to an attached
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process when handling SIGINT */
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/* ARGSUSED */
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static void
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pass_signal (signo)
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int signo;
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{
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kill (inferior_pid, SIGINT);
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}
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static void (*osig)();
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void
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set_sigint_trap()
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{
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osig = (void (*) ()) signal (SIGINT, pass_signal);
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}
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void
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clear_sigint_trap()
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{
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signal (SIGINT, osig);
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}
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void
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_initialize_inflow ()
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{
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add_info ("terminal", term_info,
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"Print inferior's saved terminal status.");
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add_com ("kill", class_run, kill_command,
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"Kill execution of program being debugged.");
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inferior_pid = 0;
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terminal_is_ours = 1;
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}
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