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 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
29 #include "gdbthread.h"
31 #include "gdb_string.h"
34 #ifdef HAVE_SYS_SELECT_H
35 #include <sys/select.h>
40 #ifdef HAVE_SYS_IOCTL_H
41 #include <sys/ioctl.h>
44 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
45 static void handle_sigio (int);
48 extern void _initialize_inflow (void);
50 static void pass_signal (int);
52 static void kill_command (char *, int);
54 static void terminal_ours_1 (int);
56 /* Record terminal status separately for debugger and inferior. */
58 static struct serial
*stdin_serial
;
60 /* TTY state for the inferior. We save it whenever the inferior stops, and
61 restore it when it resumes. */
62 static serial_ttystate inferior_ttystate
;
64 /* Our own tty state, which we restore every time we need to deal with the
65 terminal. We only set it once, when GDB first starts. The settings of
66 flags which readline saves and restores and unimportant. */
67 static serial_ttystate our_ttystate
;
69 /* fcntl flags for us and the inferior. Saved and restored just like
70 {our,inferior}_ttystate. */
71 static int tflags_inferior
;
72 static int tflags_ours
;
74 #ifdef PROCESS_GROUP_TYPE
75 /* Process group for us and the inferior. Saved and restored just like
76 {our,inferior}_ttystate. */
77 PROCESS_GROUP_TYPE our_process_group
;
78 PROCESS_GROUP_TYPE inferior_process_group
;
81 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
82 inferior only. If we have job control, that takes care of it. If not,
83 we save our handlers in these two variables and set SIGINT and SIGQUIT
86 static void (*sigint_ours
) ();
87 static void (*sigquit_ours
) ();
89 /* The name of the tty (from the `tty' command) that we gave to the inferior
90 when it was last started. */
92 static char *inferior_thisrun_terminal
;
94 /* Nonzero if our terminal settings are in effect. Zero if the
95 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
102 yes
, no
, have_not_checked
104 gdb_has_a_terminal_flag
= have_not_checked
;
106 /* Does GDB have a terminal (on stdin)? */
108 gdb_has_a_terminal (void)
110 switch (gdb_has_a_terminal_flag
)
116 case have_not_checked
:
117 /* Get all the current tty settings (including whether we have a
118 tty at all!). Can't do this in _initialize_inflow because
119 serial_fdopen() won't work until the serial_ops_list is
123 tflags_ours
= fcntl (0, F_GETFL
, 0);
126 gdb_has_a_terminal_flag
= no
;
127 stdin_serial
= serial_fdopen (0);
128 if (stdin_serial
!= NULL
)
130 our_ttystate
= serial_get_tty_state (stdin_serial
);
132 if (our_ttystate
!= NULL
)
134 gdb_has_a_terminal_flag
= yes
;
136 our_process_group
= tcgetpgrp (0);
139 our_process_group
= getpgrp ();
142 ioctl (0, TIOCGPGRP
, &our_process_group
);
147 return gdb_has_a_terminal_flag
== yes
;
149 /* "Can't happen". */
154 /* Macro for printing errors from ioctl operations */
156 #define OOPSY(what) \
158 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
159 what, safe_strerror (errno))
161 static void terminal_ours_1 (int);
163 /* Initialize the terminal settings we record for the inferior,
164 before we actually run the inferior. */
167 terminal_init_inferior_with_pgrp (int pgrp
)
169 if (gdb_has_a_terminal ())
171 /* We could just as well copy our_ttystate (if we felt like
172 adding a new function serial_copy_tty_state()). */
173 if (inferior_ttystate
)
174 xfree (inferior_ttystate
);
175 inferior_ttystate
= serial_get_tty_state (stdin_serial
);
177 #ifdef PROCESS_GROUP_TYPE
178 inferior_process_group
= pgrp
;
181 /* Make sure that next time we call terminal_inferior (which will be
182 before the program runs, as it needs to be), we install the new
184 terminal_is_ours
= 1;
188 /* Save the terminal settings again. This is necessary for the TUI
189 when it switches to TUI or non-TUI mode; curses changes the terminal
190 and gdb must be able to restore it correctly. */
193 terminal_save_ours (void)
195 if (gdb_has_a_terminal ())
197 /* We could just as well copy our_ttystate (if we felt like adding
198 a new function serial_copy_tty_state). */
200 xfree (our_ttystate
);
201 our_ttystate
= serial_get_tty_state (stdin_serial
);
206 terminal_init_inferior (void)
208 #ifdef PROCESS_GROUP_TYPE
209 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
210 debugging target with a version of target_terminal_init_inferior which
211 passes in the process group to a generic routine which does all the work
212 (and the non-threaded child_terminal_init_inferior can just pass in
213 inferior_ptid to the same routine). */
214 /* We assume INFERIOR_PID is also the child's process group. */
215 terminal_init_inferior_with_pgrp (PIDGET (inferior_ptid
));
216 #endif /* PROCESS_GROUP_TYPE */
219 /* Put the inferior's terminal settings into effect.
220 This is preparation for starting or resuming the inferior. */
223 terminal_inferior (void)
225 if (gdb_has_a_terminal () && terminal_is_ours
226 && inferior_thisrun_terminal
== 0)
231 /* Is there a reason this is being done twice? It happens both
232 places we use F_SETFL, so I'm inclined to think perhaps there
233 is some reason, however perverse. Perhaps not though... */
234 result
= fcntl (0, F_SETFL
, tflags_inferior
);
235 result
= fcntl (0, F_SETFL
, tflags_inferior
);
236 OOPSY ("fcntl F_SETFL");
239 /* Because we were careful to not change in or out of raw mode in
240 terminal_ours, we will not change in our out of raw mode with
241 this call, so we don't flush any input. */
242 result
= serial_set_tty_state (stdin_serial
, inferior_ttystate
);
243 OOPSY ("setting tty state");
247 sigint_ours
= (void (*)()) signal (SIGINT
, SIG_IGN
);
249 sigquit_ours
= (void (*)()) signal (SIGQUIT
, SIG_IGN
);
253 /* If attach_flag is set, we don't know whether we are sharing a
254 terminal with the inferior or not. (attaching a process
255 without a terminal is one case where we do not; attaching a
256 process which we ran from the same shell as GDB via `&' is
257 one case where we do, I think (but perhaps this is not
258 `sharing' in the sense that we need to save and restore tty
259 state)). I don't know if there is any way to tell whether we
260 are sharing a terminal. So what we do is to go through all
261 the saving and restoring of the tty state, but ignore errors
262 setting the process group, which will happen if we are not
263 sharing a terminal). */
268 result
= tcsetpgrp (0, inferior_process_group
);
274 result
= ioctl (0, TIOCSPGRP
, &inferior_process_group
);
281 terminal_is_ours
= 0;
284 /* Put some of our terminal settings into effect,
285 enough to get proper results from our output,
286 but do not change into or out of RAW mode
287 so that no input is discarded.
289 After doing this, either terminal_ours or terminal_inferior
290 should be called to get back to a normal state of affairs. */
293 terminal_ours_for_output (void)
298 /* Put our terminal settings into effect.
299 First record the inferior's terminal settings
300 so they can be restored properly later. */
308 /* output_only is not used, and should not be used unless we introduce
309 separate terminal_is_ours and terminal_is_ours_for_output
313 terminal_ours_1 (int output_only
)
315 /* Checking inferior_thisrun_terminal is necessary so that
316 if GDB is running in the background, it won't block trying
317 to do the ioctl()'s below. Checking gdb_has_a_terminal
318 avoids attempting all the ioctl's when running in batch. */
319 if (inferior_thisrun_terminal
!= 0 || gdb_has_a_terminal () == 0)
322 if (!terminal_is_ours
)
325 /* Ignore this signal since it will happen when we try to set the
327 void (*osigttou
) () = NULL
;
331 terminal_is_ours
= 1;
335 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
338 if (inferior_ttystate
)
339 xfree (inferior_ttystate
);
340 inferior_ttystate
= serial_get_tty_state (stdin_serial
);
342 inferior_process_group
= tcgetpgrp (0);
345 inferior_process_group
= getpgrp ();
348 ioctl (0, TIOCGPGRP
, &inferior_process_group
);
351 /* Here we used to set ICANON in our ttystate, but I believe this
352 was an artifact from before when we used readline. Readline sets
353 the tty state when it needs to.
354 FIXME-maybe: However, query() expects non-raw mode and doesn't
355 use readline. Maybe query should use readline (on the other hand,
356 this only matters for HAVE_SGTTY, not termio or termios, I think). */
358 /* Set tty state to our_ttystate. We don't change in our out of raw
359 mode, to avoid flushing input. We need to do the same thing
360 regardless of output_only, because we don't have separate
361 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
362 though, since readline will deal with raw mode when/if it needs to.
365 serial_noflush_set_tty_state (stdin_serial
, our_ttystate
,
371 result
= tcsetpgrp (0, our_process_group
);
373 /* This fails on Ultrix with EINVAL if you run the testsuite
374 in the background with nohup, and then log out. GDB never
375 used to check for an error here, so perhaps there are other
376 such situations as well. */
378 fprintf_unfiltered (gdb_stderr
, "[tcsetpgrp failed in terminal_ours: %s]\n",
379 safe_strerror (errno
));
384 result
= ioctl (0, TIOCSPGRP
, &our_process_group
);
390 signal (SIGTTOU
, osigttou
);
395 signal (SIGINT
, sigint_ours
);
397 signal (SIGQUIT
, sigquit_ours
);
402 tflags_inferior
= fcntl (0, F_GETFL
, 0);
404 /* Is there a reason this is being done twice? It happens both
405 places we use F_SETFL, so I'm inclined to think perhaps there
406 is some reason, however perverse. Perhaps not though... */
407 result
= fcntl (0, F_SETFL
, tflags_ours
);
408 result
= fcntl (0, F_SETFL
, tflags_ours
);
411 result
= result
; /* lint */
416 term_info (char *arg
, int from_tty
)
418 target_terminal_info (arg
, from_tty
);
422 child_terminal_info (char *args
, int from_tty
)
424 if (!gdb_has_a_terminal ())
426 printf_filtered ("This GDB does not control a terminal.\n");
430 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
432 /* First the fcntl flags. */
436 flags
= tflags_inferior
;
438 printf_filtered ("File descriptor flags = ");
441 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
443 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
444 switch (flags
& (O_ACCMODE
))
447 printf_filtered ("O_RDONLY");
450 printf_filtered ("O_WRONLY");
453 printf_filtered ("O_RDWR");
456 flags
&= ~(O_ACCMODE
);
459 if (flags
& O_NONBLOCK
)
460 printf_filtered (" | O_NONBLOCK");
461 flags
&= ~O_NONBLOCK
;
464 #if defined (O_NDELAY)
465 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
466 print it as O_NONBLOCK, which is good cause that is what POSIX
467 has, and the flag will already be cleared by the time we get here. */
468 if (flags
& O_NDELAY
)
469 printf_filtered (" | O_NDELAY");
473 if (flags
& O_APPEND
)
474 printf_filtered (" | O_APPEND");
477 #if defined (O_BINARY)
478 if (flags
& O_BINARY
)
479 printf_filtered (" | O_BINARY");
484 printf_filtered (" | 0x%x", flags
);
485 printf_filtered ("\n");
488 #ifdef PROCESS_GROUP_TYPE
489 printf_filtered ("Process group = %d\n",
490 (int) inferior_process_group
);
493 serial_print_tty_state (stdin_serial
, inferior_ttystate
, gdb_stdout
);
496 /* NEW_TTY_PREFORK is called before forking a new child process,
497 so we can record the state of ttys in the child to be formed.
498 TTYNAME is null if we are to share the terminal with gdb;
499 or points to a string containing the name of the desired tty.
501 NEW_TTY is called in new child processes under Unix, which will
502 become debugger target processes. This actually switches to
503 the terminal specified in the NEW_TTY_PREFORK call. */
506 new_tty_prefork (char *ttyname
)
508 /* Save the name for later, for determining whether we and the child
509 are sharing a tty. */
510 inferior_thisrun_terminal
= ttyname
;
518 if (inferior_thisrun_terminal
== 0)
520 #if !defined(__GO32__) && !defined(_WIN32)
522 /* Disconnect the child process from our controlling terminal. On some
523 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
525 tty
= open ("/dev/tty", O_RDWR
);
530 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
531 ioctl (tty
, TIOCNOTTY
, 0);
533 signal (SIGTTOU
, osigttou
);
537 /* Now open the specified new terminal. */
540 tty
= open (inferior_thisrun_terminal
, O_RDWR
| O_NOCTTY
);
542 tty
= open (inferior_thisrun_terminal
, O_RDWR
);
546 print_sys_errmsg (inferior_thisrun_terminal
, errno
);
550 /* Avoid use of dup2; doesn't exist on all systems. */
568 #endif /* !go32 && !win32 */
571 /* Kill the inferior process. Make us have no inferior. */
574 kill_command (char *arg
, int from_tty
)
576 /* FIXME: This should not really be inferior_ptid (or target_has_execution).
577 It should be a distinct flag that indicates that a target is active, cuz
578 some targets don't have processes! */
580 if (ptid_equal (inferior_ptid
, null_ptid
))
581 error ("The program is not being run.");
582 if (!query ("Kill the program being debugged? "))
583 error ("Not confirmed.");
586 init_thread_list (); /* Destroy thread info */
588 /* Killing off the inferior can leave us with a core file. If so,
589 print the state we are left in. */
590 if (target_has_stack
)
592 printf_filtered ("In %s,\n", target_longname
);
593 if (deprecated_selected_frame
== NULL
)
594 fputs_filtered ("No selected stack frame.\n", gdb_stdout
);
596 print_stack_frame (deprecated_selected_frame
,
597 frame_relative_level (deprecated_selected_frame
), 1);
601 /* Call set_sigint_trap when you need to pass a signal on to an attached
602 process when handling SIGINT */
605 pass_signal (int signo
)
608 kill (PIDGET (inferior_ptid
), SIGINT
);
612 static void (*osig
) ();
615 set_sigint_trap (void)
617 if (attach_flag
|| inferior_thisrun_terminal
)
619 osig
= (void (*)()) signal (SIGINT
, pass_signal
);
624 clear_sigint_trap (void)
626 if (attach_flag
|| inferior_thisrun_terminal
)
628 signal (SIGINT
, osig
);
632 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
633 static void (*old_sigio
) ();
636 handle_sigio (int signo
)
641 signal (SIGIO
, handle_sigio
);
644 FD_SET (target_activity_fd
, &readfds
);
645 numfds
= select (target_activity_fd
+ 1, &readfds
, NULL
, NULL
, NULL
);
646 if (numfds
>= 0 && FD_ISSET (target_activity_fd
, &readfds
))
649 if ((*target_activity_function
) ())
650 kill (PIDGET (inferior_ptid
), SIGINT
);
655 static int old_fcntl_flags
;
658 set_sigio_trap (void)
660 if (target_activity_function
)
662 old_sigio
= (void (*)()) signal (SIGIO
, handle_sigio
);
663 fcntl (target_activity_fd
, F_SETOWN
, getpid ());
664 old_fcntl_flags
= fcntl (target_activity_fd
, F_GETFL
, 0);
665 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
| FASYNC
);
670 clear_sigio_trap (void)
672 if (target_activity_function
)
674 signal (SIGIO
, old_sigio
);
675 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
);
678 #else /* No SIGIO. */
680 set_sigio_trap (void)
682 if (target_activity_function
)
683 internal_error (__FILE__
, __LINE__
, "failed internal consistency check");
687 clear_sigio_trap (void)
689 if (target_activity_function
)
690 internal_error (__FILE__
, __LINE__
, "failed internal consistency check");
692 #endif /* No SIGIO. */
695 /* This is here because this is where we figure out whether we (probably)
696 have job control. Just using job_control only does part of it because
697 setpgid or setpgrp might not exist on a system without job control.
698 It might be considered misplaced (on the other hand, process groups and
699 job control are closely related to ttys).
701 For a more clean implementation, in libiberty, put a setpgid which merely
702 calls setpgrp and a setpgrp which does nothing (any system with job control
703 will have one or the other). */
711 #if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
713 /* The call setpgid (0, 0) is supposed to work and mean the same
714 thing as this, but on Ultrix 4.2A it fails with EPERM (and
715 setpgid (getpid (), getpid ()) succeeds). */
716 retval
= setpgid (getpid (), getpid ());
722 retval
= setpgrp (getpid (), getpid ());
724 #endif /* HAVE_SETPGRP */
725 #endif /* HAVE_SETPGID */
726 #endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
733 _initialize_inflow (void)
735 add_info ("terminal", term_info
,
736 "Print inferior's saved terminal status.");
738 add_com ("kill", class_run
, kill_command
,
739 "Kill execution of program being debugged.");
741 inferior_ptid
= null_ptid
;
743 terminal_is_ours
= 1;
745 /* OK, figure out whether we have job control. If neither termios nor
746 sgtty (i.e. termio or go32), leave job_control 0. */
748 #if defined (HAVE_TERMIOS)
749 /* Do all systems with termios have the POSIX way of identifying job
750 control? I hope so. */
751 #ifdef _POSIX_JOB_CONTROL
754 #ifdef _SC_JOB_CONTROL
755 job_control
= sysconf (_SC_JOB_CONTROL
);
757 job_control
= 0; /* have to assume the worst */
758 #endif /* _SC_JOB_CONTROL */
759 #endif /* _POSIX_JOB_CONTROL */
760 #endif /* HAVE_TERMIOS */
767 #endif /* TIOCGPGRP */