1 /* Low level interface to ptrace, for GDB when running under Unix.
2 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
3 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
30 #include "gdbthread.h"
32 #include "gdb_string.h"
35 #ifdef HAVE_SYS_SELECT_H
36 #include <sys/select.h>
41 #ifdef HAVE_SYS_IOCTL_H
42 #include <sys/ioctl.h>
49 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
50 static void handle_sigio (int);
53 extern void _initialize_inflow (void);
55 static void pass_signal (int);
57 static void kill_command (char *, int);
59 static void terminal_ours_1 (int);
61 /* Record terminal status separately for debugger and inferior. */
63 static struct serial *stdin_serial;
65 /* TTY state for the inferior. We save it whenever the inferior stops, and
66 restore it when it resumes. */
67 static serial_ttystate inferior_ttystate;
69 /* Our own tty state, which we restore every time we need to deal with the
70 terminal. We only set it once, when GDB first starts. The settings of
71 flags which readline saves and restores and unimportant. */
72 static serial_ttystate our_ttystate;
74 /* fcntl flags for us and the inferior. Saved and restored just like
75 {our,inferior}_ttystate. */
76 static int tflags_inferior;
77 static int tflags_ours;
79 #ifdef PROCESS_GROUP_TYPE
80 /* Process group for us and the inferior. Saved and restored just like
81 {our,inferior}_ttystate. */
82 PROCESS_GROUP_TYPE our_process_group;
83 PROCESS_GROUP_TYPE inferior_process_group;
86 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
87 inferior only. If we have job control, that takes care of it. If not,
88 we save our handlers in these two variables and set SIGINT and SIGQUIT
91 static void (*sigint_ours) ();
92 static void (*sigquit_ours) ();
94 /* The name of the tty (from the `tty' command) that we gave to the inferior
95 when it was last started. */
97 static char *inferior_thisrun_terminal;
99 /* Nonzero if our terminal settings are in effect. Zero if the
100 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
103 int terminal_is_ours;
107 yes, no, have_not_checked
109 gdb_has_a_terminal_flag = have_not_checked;
111 /* Does GDB have a terminal (on stdin)? */
113 gdb_has_a_terminal (void)
115 switch (gdb_has_a_terminal_flag)
121 case have_not_checked:
122 /* Get all the current tty settings (including whether we have a
123 tty at all!). Can't do this in _initialize_inflow because
124 serial_fdopen() won't work until the serial_ops_list is
128 tflags_ours = fcntl (0, F_GETFL, 0);
131 gdb_has_a_terminal_flag = no;
132 stdin_serial = serial_fdopen (0);
133 if (stdin_serial != NULL)
135 our_ttystate = serial_get_tty_state (stdin_serial);
137 if (our_ttystate != NULL)
139 gdb_has_a_terminal_flag = yes;
141 our_process_group = tcgetpgrp (0);
144 our_process_group = getpgrp ();
147 ioctl (0, TIOCGPGRP, &our_process_group);
152 return gdb_has_a_terminal_flag == yes;
154 /* "Can't happen". */
159 /* Macro for printing errors from ioctl operations */
161 #define OOPSY(what) \
163 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
164 what, safe_strerror (errno))
166 static void terminal_ours_1 (int);
168 /* Initialize the terminal settings we record for the inferior,
169 before we actually run the inferior. */
172 terminal_init_inferior_with_pgrp (int pgrp)
174 if (gdb_has_a_terminal ())
176 /* We could just as well copy our_ttystate (if we felt like
177 adding a new function serial_copy_tty_state()). */
178 if (inferior_ttystate)
179 xfree (inferior_ttystate);
180 inferior_ttystate = serial_get_tty_state (stdin_serial);
182 #ifdef PROCESS_GROUP_TYPE
183 inferior_process_group = pgrp;
186 /* Make sure that next time we call terminal_inferior (which will be
187 before the program runs, as it needs to be), we install the new
189 terminal_is_ours = 1;
193 /* Save the terminal settings again. This is necessary for the TUI
194 when it switches to TUI or non-TUI mode; curses changes the terminal
195 and gdb must be able to restore it correctly. */
198 terminal_save_ours (void)
200 if (gdb_has_a_terminal ())
202 /* We could just as well copy our_ttystate (if we felt like adding
203 a new function serial_copy_tty_state). */
205 xfree (our_ttystate);
206 our_ttystate = serial_get_tty_state (stdin_serial);
211 terminal_init_inferior (void)
213 #ifdef PROCESS_GROUP_TYPE
214 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
215 debugging target with a version of target_terminal_init_inferior which
216 passes in the process group to a generic routine which does all the work
217 (and the non-threaded child_terminal_init_inferior can just pass in
218 inferior_ptid to the same routine). */
219 /* We assume INFERIOR_PID is also the child's process group. */
220 terminal_init_inferior_with_pgrp (PIDGET (inferior_ptid));
221 #endif /* PROCESS_GROUP_TYPE */
224 /* Put the inferior's terminal settings into effect.
225 This is preparation for starting or resuming the inferior. */
228 terminal_inferior (void)
230 if (gdb_has_a_terminal () && terminal_is_ours
231 && inferior_ttystate != NULL
232 && inferior_thisrun_terminal == 0)
237 /* Is there a reason this is being done twice? It happens both
238 places we use F_SETFL, so I'm inclined to think perhaps there
239 is some reason, however perverse. Perhaps not though... */
240 result = fcntl (0, F_SETFL, tflags_inferior);
241 result = fcntl (0, F_SETFL, tflags_inferior);
242 OOPSY ("fcntl F_SETFL");
245 /* Because we were careful to not change in or out of raw mode in
246 terminal_ours, we will not change in our out of raw mode with
247 this call, so we don't flush any input. */
248 result = serial_set_tty_state (stdin_serial, inferior_ttystate);
249 OOPSY ("setting tty state");
253 sigint_ours = (void (*)()) signal (SIGINT, SIG_IGN);
255 sigquit_ours = (void (*)()) signal (SIGQUIT, SIG_IGN);
259 /* If attach_flag is set, we don't know whether we are sharing a
260 terminal with the inferior or not. (attaching a process
261 without a terminal is one case where we do not; attaching a
262 process which we ran from the same shell as GDB via `&' is
263 one case where we do, I think (but perhaps this is not
264 `sharing' in the sense that we need to save and restore tty
265 state)). I don't know if there is any way to tell whether we
266 are sharing a terminal. So what we do is to go through all
267 the saving and restoring of the tty state, but ignore errors
268 setting the process group, which will happen if we are not
269 sharing a terminal). */
274 result = tcsetpgrp (0, inferior_process_group);
280 result = ioctl (0, TIOCSPGRP, &inferior_process_group);
287 terminal_is_ours = 0;
290 /* Put some of our terminal settings into effect,
291 enough to get proper results from our output,
292 but do not change into or out of RAW mode
293 so that no input is discarded.
295 After doing this, either terminal_ours or terminal_inferior
296 should be called to get back to a normal state of affairs. */
299 terminal_ours_for_output (void)
304 /* Put our terminal settings into effect.
305 First record the inferior's terminal settings
306 so they can be restored properly later. */
314 /* output_only is not used, and should not be used unless we introduce
315 separate terminal_is_ours and terminal_is_ours_for_output
319 terminal_ours_1 (int output_only)
321 /* Checking inferior_thisrun_terminal is necessary so that
322 if GDB is running in the background, it won't block trying
323 to do the ioctl()'s below. Checking gdb_has_a_terminal
324 avoids attempting all the ioctl's when running in batch. */
325 if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)
328 if (!terminal_is_ours)
331 /* Ignore this signal since it will happen when we try to set the
333 void (*osigttou) () = NULL;
337 terminal_is_ours = 1;
341 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
344 if (inferior_ttystate)
345 xfree (inferior_ttystate);
346 inferior_ttystate = serial_get_tty_state (stdin_serial);
348 inferior_process_group = tcgetpgrp (0);
351 inferior_process_group = getpgrp ();
354 ioctl (0, TIOCGPGRP, &inferior_process_group);
357 /* Here we used to set ICANON in our ttystate, but I believe this
358 was an artifact from before when we used readline. Readline sets
359 the tty state when it needs to.
360 FIXME-maybe: However, query() expects non-raw mode and doesn't
361 use readline. Maybe query should use readline (on the other hand,
362 this only matters for HAVE_SGTTY, not termio or termios, I think). */
364 /* Set tty state to our_ttystate. We don't change in our out of raw
365 mode, to avoid flushing input. We need to do the same thing
366 regardless of output_only, because we don't have separate
367 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
368 though, since readline will deal with raw mode when/if it needs to.
371 serial_noflush_set_tty_state (stdin_serial, our_ttystate,
377 result = tcsetpgrp (0, our_process_group);
379 /* This fails on Ultrix with EINVAL if you run the testsuite
380 in the background with nohup, and then log out. GDB never
381 used to check for an error here, so perhaps there are other
382 such situations as well. */
384 fprintf_unfiltered (gdb_stderr, "[tcsetpgrp failed in terminal_ours: %s]\n",
385 safe_strerror (errno));
390 result = ioctl (0, TIOCSPGRP, &our_process_group);
396 signal (SIGTTOU, osigttou);
401 signal (SIGINT, sigint_ours);
403 signal (SIGQUIT, sigquit_ours);
408 tflags_inferior = fcntl (0, F_GETFL, 0);
410 /* Is there a reason this is being done twice? It happens both
411 places we use F_SETFL, so I'm inclined to think perhaps there
412 is some reason, however perverse. Perhaps not though... */
413 result = fcntl (0, F_SETFL, tflags_ours);
414 result = fcntl (0, F_SETFL, tflags_ours);
417 result = result; /* lint */
422 term_info (char *arg, int from_tty)
424 target_terminal_info (arg, from_tty);
428 child_terminal_info (char *args, int from_tty)
430 if (!gdb_has_a_terminal ())
432 printf_filtered ("This GDB does not control a terminal.\n");
436 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
438 /* First the fcntl flags. */
442 flags = tflags_inferior;
444 printf_filtered ("File descriptor flags = ");
447 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
449 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
450 switch (flags & (O_ACCMODE))
453 printf_filtered ("O_RDONLY");
456 printf_filtered ("O_WRONLY");
459 printf_filtered ("O_RDWR");
462 flags &= ~(O_ACCMODE);
465 if (flags & O_NONBLOCK)
466 printf_filtered (" | O_NONBLOCK");
467 flags &= ~O_NONBLOCK;
470 #if defined (O_NDELAY)
471 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
472 print it as O_NONBLOCK, which is good cause that is what POSIX
473 has, and the flag will already be cleared by the time we get here. */
474 if (flags & O_NDELAY)
475 printf_filtered (" | O_NDELAY");
479 if (flags & O_APPEND)
480 printf_filtered (" | O_APPEND");
483 #if defined (O_BINARY)
484 if (flags & O_BINARY)
485 printf_filtered (" | O_BINARY");
490 printf_filtered (" | 0x%x", flags);
491 printf_filtered ("\n");
494 #ifdef PROCESS_GROUP_TYPE
495 printf_filtered ("Process group = %d\n",
496 (int) inferior_process_group);
499 serial_print_tty_state (stdin_serial, inferior_ttystate, gdb_stdout);
502 /* NEW_TTY_PREFORK is called before forking a new child process,
503 so we can record the state of ttys in the child to be formed.
504 TTYNAME is null if we are to share the terminal with gdb;
505 or points to a string containing the name of the desired tty.
507 NEW_TTY is called in new child processes under Unix, which will
508 become debugger target processes. This actually switches to
509 the terminal specified in the NEW_TTY_PREFORK call. */
512 new_tty_prefork (char *ttyname)
514 /* Save the name for later, for determining whether we and the child
515 are sharing a tty. */
516 inferior_thisrun_terminal = ttyname;
524 if (inferior_thisrun_terminal == 0)
526 #if !defined(__GO32__) && !defined(_WIN32)
528 /* Disconnect the child process from our controlling terminal. On some
529 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
531 tty = open ("/dev/tty", O_RDWR);
536 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
537 ioctl (tty, TIOCNOTTY, 0);
539 signal (SIGTTOU, osigttou);
543 /* Now open the specified new terminal. */
544 tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
547 print_sys_errmsg (inferior_thisrun_terminal, errno);
551 /* Avoid use of dup2; doesn't exist on all systems. */
569 #endif /* !go32 && !win32 */
572 /* Kill the inferior process. Make us have no inferior. */
575 kill_command (char *arg, int from_tty)
577 /* FIXME: This should not really be inferior_ptid (or target_has_execution).
578 It should be a distinct flag that indicates that a target is active, cuz
579 some targets don't have processes! */
581 if (ptid_equal (inferior_ptid, null_ptid))
582 error (_("The program is not being run."));
583 if (!query ("Kill the program being debugged? "))
584 error (_("Not confirmed."));
587 init_thread_list (); /* Destroy thread info */
589 /* Killing off the inferior can leave us with a core file. If so,
590 print the state we are left in. */
591 if (target_has_stack)
593 printf_filtered ("In %s,\n", target_longname);
594 if (deprecated_selected_frame == NULL)
595 fputs_filtered ("No selected stack frame.\n", gdb_stdout);
597 print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
599 bfd_cache_close_all ();
602 /* Call set_sigint_trap when you need to pass a signal on to an attached
603 process when handling SIGINT */
606 pass_signal (int signo)
609 kill (PIDGET (inferior_ptid), SIGINT);
613 static void (*osig) ();
616 set_sigint_trap (void)
618 if (attach_flag || inferior_thisrun_terminal)
620 osig = (void (*)()) signal (SIGINT, pass_signal);
625 clear_sigint_trap (void)
627 if (attach_flag || inferior_thisrun_terminal)
629 signal (SIGINT, osig);
633 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
634 static void (*old_sigio) ();
637 handle_sigio (int signo)
642 signal (SIGIO, handle_sigio);
645 FD_SET (target_activity_fd, &readfds);
646 numfds = select (target_activity_fd + 1, &readfds, NULL, NULL, NULL);
647 if (numfds >= 0 && FD_ISSET (target_activity_fd, &readfds))
650 if ((*target_activity_function) ())
651 kill (PIDGET (inferior_ptid), SIGINT);
656 static int old_fcntl_flags;
659 set_sigio_trap (void)
661 if (target_activity_function)
663 old_sigio = (void (*)()) signal (SIGIO, handle_sigio);
664 fcntl (target_activity_fd, F_SETOWN, getpid ());
665 old_fcntl_flags = fcntl (target_activity_fd, F_GETFL, 0);
666 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags | FASYNC);
671 clear_sigio_trap (void)
673 if (target_activity_function)
675 signal (SIGIO, old_sigio);
676 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags);
679 #else /* No SIGIO. */
681 set_sigio_trap (void)
683 if (target_activity_function)
684 internal_error (__FILE__, __LINE__, "failed internal consistency check");
688 clear_sigio_trap (void)
690 if (target_activity_function)
691 internal_error (__FILE__, __LINE__, "failed internal consistency check");
693 #endif /* No SIGIO. */
696 /* This is here because this is where we figure out whether we (probably)
697 have job control. Just using job_control only does part of it because
698 setpgid or setpgrp might not exist on a system without job control.
699 It might be considered misplaced (on the other hand, process groups and
700 job control are closely related to ttys).
702 For a more clean implementation, in libiberty, put a setpgid which merely
703 calls setpgrp and a setpgrp which does nothing (any system with job control
704 will have one or the other). */
712 #if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
714 /* The call setpgid (0, 0) is supposed to work and mean the same
715 thing as this, but on Ultrix 4.2A it fails with EPERM (and
716 setpgid (getpid (), getpid ()) succeeds). */
717 retval = setpgid (getpid (), getpid ());
723 retval = setpgrp (getpid (), getpid ());
725 #endif /* HAVE_SETPGRP */
726 #endif /* HAVE_SETPGID */
727 #endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
734 _initialize_inflow (void)
736 add_info ("terminal", term_info,
737 "Print inferior's saved terminal status.");
739 add_com ("kill", class_run, kill_command,
740 "Kill execution of program being debugged.");
742 inferior_ptid = null_ptid;
744 terminal_is_ours = 1;
746 /* OK, figure out whether we have job control. If neither termios nor
747 sgtty (i.e. termio or go32), leave job_control 0. */
749 #if defined (HAVE_TERMIOS)
750 /* Do all systems with termios have the POSIX way of identifying job
751 control? I hope so. */
752 #ifdef _POSIX_JOB_CONTROL
755 #ifdef _SC_JOB_CONTROL
756 job_control = sysconf (_SC_JOB_CONTROL);
758 job_control = 0; /* have to assume the worst */
759 #endif /* _SC_JOB_CONTROL */
760 #endif /* _POSIX_JOB_CONTROL */
761 #endif /* HAVE_TERMIOS */
768 #endif /* TIOCGPGRP */