1 /* Low level interface to ptrace, for GDB when running under Unix.
2 Copyright 1986-87, 1989, 1991-92, 1995, 1998 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
28 #include "gdbthread.h"
30 #include "gdb_string.h"
36 #ifdef HAVE_SYS_SELECT_H
37 #include <sys/select.h>
41 #define PROCESS_GROUP_TYPE pid_t
45 #define PROCESS_GROUP_TYPE int
50 /* This is only used for the ultra. Does it have pid_t? */
51 #define PROCESS_GROUP_TYPE short
53 #define PROCESS_GROUP_TYPE int
57 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
59 handle_sigio
PARAMS ((int));
62 extern void _initialize_inflow
PARAMS ((void));
65 pass_signal
PARAMS ((int));
68 kill_command
PARAMS ((char *, int));
71 terminal_ours_1
PARAMS ((int));
73 /* Record terminal status separately for debugger and inferior. */
75 static serial_t stdin_serial
;
77 /* TTY state for the inferior. We save it whenever the inferior stops, and
78 restore it when it resumes. */
79 static serial_ttystate inferior_ttystate
;
81 /* Our own tty state, which we restore every time we need to deal with the
82 terminal. We only set it once, when GDB first starts. The settings of
83 flags which readline saves and restores and unimportant. */
84 static serial_ttystate our_ttystate
;
86 /* fcntl flags for us and the inferior. Saved and restored just like
87 {our,inferior}_ttystate. */
88 static int tflags_inferior
;
89 static int tflags_ours
;
91 #ifdef PROCESS_GROUP_TYPE
92 /* Process group for us and the inferior. Saved and restored just like
93 {our,inferior}_ttystate. */
94 PROCESS_GROUP_TYPE our_process_group
;
95 PROCESS_GROUP_TYPE inferior_process_group
;
98 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
99 inferior only. If we have job control, that takes care of it. If not,
100 we save our handlers in these two variables and set SIGINT and SIGQUIT
103 static void (*sigint_ours
) ();
104 static void (*sigquit_ours
) ();
106 /* The name of the tty (from the `tty' command) that we gave to the inferior
107 when it was last started. */
109 static char *inferior_thisrun_terminal
;
111 /* Nonzero if our terminal settings are in effect. Zero if the
112 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
115 int terminal_is_ours
;
117 enum {yes
, no
, have_not_checked
} gdb_has_a_terminal_flag
= have_not_checked
;
119 /* Does GDB have a terminal (on stdin)? */
121 gdb_has_a_terminal ()
123 switch (gdb_has_a_terminal_flag
)
129 case have_not_checked
:
130 /* Get all the current tty settings (including whether we have a tty at
131 all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
132 won't work until the serial_ops_list is initialized. */
135 tflags_ours
= fcntl (0, F_GETFL
, 0);
138 gdb_has_a_terminal_flag
= no
;
139 stdin_serial
= SERIAL_FDOPEN (0);
140 if (stdin_serial
!= NULL
)
142 our_ttystate
= SERIAL_GET_TTY_STATE (stdin_serial
);
144 if (our_ttystate
!= NULL
)
146 gdb_has_a_terminal_flag
= yes
;
148 our_process_group
= tcgetpgrp (0);
151 our_process_group
= getpgrp ();
154 ioctl (0, TIOCGPGRP
, &our_process_group
);
159 return gdb_has_a_terminal_flag
== yes
;
161 /* "Can't happen". */
166 /* Macro for printing errors from ioctl operations */
168 #define OOPSY(what) \
170 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
171 what, strerror (errno))
173 static void terminal_ours_1
PARAMS ((int));
175 /* Initialize the terminal settings we record for the inferior,
176 before we actually run the inferior. */
179 terminal_init_inferior_with_pgrp (pgrp
)
182 if (gdb_has_a_terminal ())
184 /* We could just as well copy our_ttystate (if we felt like adding
185 a new function SERIAL_COPY_TTY_STATE). */
186 if (inferior_ttystate
)
187 free (inferior_ttystate
);
188 inferior_ttystate
= SERIAL_GET_TTY_STATE (stdin_serial
);
190 #ifdef PROCESS_GROUP_TYPE
191 inferior_process_group
= pgrp
;
194 /* Make sure that next time we call terminal_inferior (which will be
195 before the program runs, as it needs to be), we install the new
197 terminal_is_ours
= 1;
202 terminal_init_inferior ()
204 #ifdef PROCESS_GROUP_TYPE
205 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
206 debugging target with a version of target_terminal_init_inferior which
207 passes in the process group to a generic routine which does all the work
208 (and the non-threaded child_terminal_init_inferior can just pass in
209 inferior_pid to the same routine). */
210 /* We assume INFERIOR_PID is also the child's process group. */
211 terminal_init_inferior_with_pgrp (PIDGET (inferior_pid
));
212 #endif /* PROCESS_GROUP_TYPE */
215 /* Put the inferior's terminal settings into effect.
216 This is preparation for starting or resuming the inferior. */
221 if (gdb_has_a_terminal () && terminal_is_ours
222 && inferior_thisrun_terminal
== 0)
227 /* Is there a reason this is being done twice? It happens both
228 places we use F_SETFL, so I'm inclined to think perhaps there
229 is some reason, however perverse. Perhaps not though... */
230 result
= fcntl (0, F_SETFL
, tflags_inferior
);
231 result
= fcntl (0, F_SETFL
, tflags_inferior
);
232 OOPSY ("fcntl F_SETFL");
235 /* Because we were careful to not change in or out of raw mode in
236 terminal_ours, we will not change in our out of raw mode with
237 this call, so we don't flush any input. */
238 result
= SERIAL_SET_TTY_STATE (stdin_serial
, inferior_ttystate
);
239 OOPSY ("setting tty state");
243 sigint_ours
= (void (*) ()) signal (SIGINT
, SIG_IGN
);
245 sigquit_ours
= (void (*) ()) signal (SIGQUIT
, SIG_IGN
);
249 /* If attach_flag is set, we don't know whether we are sharing a
250 terminal with the inferior or not. (attaching a process
251 without a terminal is one case where we do not; attaching a
252 process which we ran from the same shell as GDB via `&' is
253 one case where we do, I think (but perhaps this is not
254 `sharing' in the sense that we need to save and restore tty
255 state)). I don't know if there is any way to tell whether we
256 are sharing a terminal. So what we do is to go through all
257 the saving and restoring of the tty state, but ignore errors
258 setting the process group, which will happen if we are not
259 sharing a terminal). */
264 result
= tcsetpgrp (0, inferior_process_group
);
270 result
= ioctl (0, TIOCSPGRP
, &inferior_process_group
);
277 terminal_is_ours
= 0;
280 /* Put some of our terminal settings into effect,
281 enough to get proper results from our output,
282 but do not change into or out of RAW mode
283 so that no input is discarded.
285 After doing this, either terminal_ours or terminal_inferior
286 should be called to get back to a normal state of affairs. */
289 terminal_ours_for_output ()
294 /* Put our terminal settings into effect.
295 First record the inferior's terminal settings
296 so they can be restored properly later. */
304 /* output_only is not used, and should not be used unless we introduce
305 separate terminal_is_ours and terminal_is_ours_for_output
309 terminal_ours_1 (output_only
)
312 /* Checking inferior_thisrun_terminal is necessary so that
313 if GDB is running in the background, it won't block trying
314 to do the ioctl()'s below. Checking gdb_has_a_terminal
315 avoids attempting all the ioctl's when running in batch. */
316 if (inferior_thisrun_terminal
!= 0 || gdb_has_a_terminal () == 0)
319 if (!terminal_is_ours
)
321 /* Ignore this signal since it will happen when we try to set the
326 terminal_is_ours
= 1;
330 osigttou
= (void (*) ()) signal (SIGTTOU
, SIG_IGN
);
333 if (inferior_ttystate
)
334 free (inferior_ttystate
);
335 inferior_ttystate
= SERIAL_GET_TTY_STATE (stdin_serial
);
337 inferior_process_group
= tcgetpgrp (0);
340 inferior_process_group
= getpgrp ();
343 ioctl (0, TIOCGPGRP
, &inferior_process_group
);
346 /* Here we used to set ICANON in our ttystate, but I believe this
347 was an artifact from before when we used readline. Readline sets
348 the tty state when it needs to.
349 FIXME-maybe: However, query() expects non-raw mode and doesn't
350 use readline. Maybe query should use readline (on the other hand,
351 this only matters for HAVE_SGTTY, not termio or termios, I think). */
353 /* Set tty state to our_ttystate. We don't change in our out of raw
354 mode, to avoid flushing input. We need to do the same thing
355 regardless of output_only, because we don't have separate
356 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
357 though, since readline will deal with raw mode when/if it needs to.
360 SERIAL_NOFLUSH_SET_TTY_STATE (stdin_serial
, our_ttystate
,
366 result
= tcsetpgrp (0, our_process_group
);
368 /* This fails on Ultrix with EINVAL if you run the testsuite
369 in the background with nohup, and then log out. GDB never
370 used to check for an error here, so perhaps there are other
371 such situations as well. */
373 fprintf_unfiltered (gdb_stderr
, "[tcsetpgrp failed in terminal_ours: %s]\n",
379 result
= ioctl (0, TIOCSPGRP
, &our_process_group
);
385 signal (SIGTTOU
, osigttou
);
390 signal (SIGINT
, sigint_ours
);
392 signal (SIGQUIT
, sigquit_ours
);
397 tflags_inferior
= fcntl (0, F_GETFL
, 0);
399 /* Is there a reason this is being done twice? It happens both
400 places we use F_SETFL, so I'm inclined to think perhaps there
401 is some reason, however perverse. Perhaps not though... */
402 result
= fcntl (0, F_SETFL
, tflags_ours
);
403 result
= fcntl (0, F_SETFL
, tflags_ours
);
406 result
= result
; /* lint */
412 term_info (arg
, from_tty
)
416 target_terminal_info (arg
, from_tty
);
421 child_terminal_info (args
, from_tty
)
425 if (!gdb_has_a_terminal ())
427 printf_filtered ("This GDB does not control a terminal.\n");
431 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
433 /* First the fcntl flags. */
437 flags
= tflags_inferior
;
439 printf_filtered ("File descriptor flags = ");
442 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
444 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
445 switch (flags
& (O_ACCMODE
))
447 case O_RDONLY
: printf_filtered ("O_RDONLY"); break;
448 case O_WRONLY
: printf_filtered ("O_WRONLY"); break;
449 case O_RDWR
: printf_filtered ("O_RDWR"); break;
451 flags
&= ~(O_ACCMODE
);
454 if (flags
& O_NONBLOCK
)
455 printf_filtered (" | O_NONBLOCK");
456 flags
&= ~O_NONBLOCK
;
459 #if defined (O_NDELAY)
460 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
461 print it as O_NONBLOCK, which is good cause that is what POSIX
462 has, and the flag will already be cleared by the time we get here. */
463 if (flags
& O_NDELAY
)
464 printf_filtered (" | O_NDELAY");
468 if (flags
& O_APPEND
)
469 printf_filtered (" | O_APPEND");
472 #if defined (O_BINARY)
473 if (flags
& O_BINARY
)
474 printf_filtered (" | O_BINARY");
479 printf_filtered (" | 0x%x", flags
);
480 printf_filtered ("\n");
483 #ifdef PROCESS_GROUP_TYPE
484 printf_filtered ("Process group = %d\n", inferior_process_group
);
487 SERIAL_PRINT_TTY_STATE (stdin_serial
, inferior_ttystate
);
490 /* NEW_TTY_PREFORK is called before forking a new child process,
491 so we can record the state of ttys in the child to be formed.
492 TTYNAME is null if we are to share the terminal with gdb;
493 or points to a string containing the name of the desired tty.
495 NEW_TTY is called in new child processes under Unix, which will
496 become debugger target processes. This actually switches to
497 the terminal specified in the NEW_TTY_PREFORK call. */
500 new_tty_prefork (ttyname
)
503 /* Save the name for later, for determining whether we and the child
504 are sharing a tty. */
505 inferior_thisrun_terminal
= ttyname
;
513 if (inferior_thisrun_terminal
== 0)
515 #if !defined(__GO32__) && !defined(_WIN32)
517 /* Disconnect the child process from our controlling terminal. On some
518 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
520 tty
= open("/dev/tty", O_RDWR
);
525 osigttou
= (void (*)()) signal(SIGTTOU
, SIG_IGN
);
526 ioctl(tty
, TIOCNOTTY
, 0);
528 signal(SIGTTOU
, osigttou
);
532 /* Now open the specified new terminal. */
535 tty
= open(inferior_thisrun_terminal
, O_RDWR
| O_NOCTTY
);
537 tty
= open(inferior_thisrun_terminal
, O_RDWR
);
541 print_sys_errmsg (inferior_thisrun_terminal
, errno
);
545 /* Avoid use of dup2; doesn't exist on all systems. */
547 { close (0); dup (tty
); }
549 { close (1); dup (tty
); }
551 { close (2); dup (tty
); }
554 #endif /* !go32 && !win32*/
557 /* Kill the inferior process. Make us have no inferior. */
561 kill_command (arg
, from_tty
)
565 /* FIXME: This should not really be inferior_pid (or target_has_execution).
566 It should be a distinct flag that indicates that a target is active, cuz
567 some targets don't have processes! */
569 if (inferior_pid
== 0)
570 error ("The program is not being run.");
571 if (!query ("Kill the program being debugged? "))
572 error ("Not confirmed.");
575 init_thread_list(); /* Destroy thread info */
577 /* Killing off the inferior can leave us with a core file. If so,
578 print the state we are left in. */
579 if (target_has_stack
) {
580 printf_filtered ("In %s,\n", target_longname
);
581 if (selected_frame
== NULL
)
582 fputs_filtered ("No selected stack frame.\n", gdb_stdout
);
584 print_stack_frame (selected_frame
, selected_frame_level
, 1);
588 /* Call set_sigint_trap when you need to pass a signal on to an attached
589 process when handling SIGINT */
597 kill (PIDGET (inferior_pid
), SIGINT
);
601 static void (*osig
)();
606 if (attach_flag
|| inferior_thisrun_terminal
)
608 osig
= (void (*) ()) signal (SIGINT
, pass_signal
);
615 if (attach_flag
|| inferior_thisrun_terminal
)
617 signal (SIGINT
, osig
);
621 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
622 static void (*old_sigio
) ();
631 signal (SIGIO
, handle_sigio
);
634 FD_SET (target_activity_fd
, &readfds
);
635 numfds
= select (target_activity_fd
+ 1, &readfds
, NULL
, NULL
, NULL
);
636 if (numfds
>= 0 && FD_ISSET (target_activity_fd
, &readfds
))
639 if ((*target_activity_function
) ())
640 kill (inferior_pid
, SIGINT
);
645 static int old_fcntl_flags
;
650 if (target_activity_function
)
652 old_sigio
= (void (*) ()) signal (SIGIO
, handle_sigio
);
653 fcntl (target_activity_fd
, F_SETOWN
, getpid());
654 old_fcntl_flags
= fcntl (target_activity_fd
, F_GETFL
, 0);
655 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
| FASYNC
);
662 if (target_activity_function
)
664 signal (SIGIO
, old_sigio
);
665 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
);
668 #else /* No SIGIO. */
672 if (target_activity_function
)
679 if (target_activity_function
)
682 #endif /* No SIGIO. */
685 /* This is here because this is where we figure out whether we (probably)
686 have job control. Just using job_control only does part of it because
687 setpgid or setpgrp might not exist on a system without job control.
688 It might be considered misplaced (on the other hand, process groups and
689 job control are closely related to ttys).
691 For a more clean implementation, in libiberty, put a setpgid which merely
692 calls setpgrp and a setpgrp which does nothing (any system with job control
693 will have one or the other). */
701 #if defined (NEED_POSIX_SETPGID) || (defined (HAVE_TERMIOS) && defined (HAVE_SETPGID))
702 /* setpgid (0, 0) is supposed to work and mean the same thing as
703 this, but on Ultrix 4.2A it fails with EPERM (and
704 setpgid (getpid (), getpid ()) succeeds). */
705 retval
= setpgid (getpid (), getpid ());
707 #if defined (TIOCGPGRP)
708 #if defined(USG) && !defined(SETPGRP_ARGS)
711 retval
= setpgrp (getpid (), getpid ());
713 #endif /* TIOCGPGRP. */
714 #endif /* NEED_POSIX_SETPGID */
720 _initialize_inflow ()
722 add_info ("terminal", term_info
,
723 "Print inferior's saved terminal status.");
725 add_com ("kill", class_run
, kill_command
,
726 "Kill execution of program being debugged.");
730 terminal_is_ours
= 1;
732 /* OK, figure out whether we have job control. If neither termios nor
733 sgtty (i.e. termio or go32), leave job_control 0. */
735 #if defined (HAVE_TERMIOS)
736 /* Do all systems with termios have the POSIX way of identifying job
737 control? I hope so. */
738 #ifdef _POSIX_JOB_CONTROL
741 #ifdef _SC_JOB_CONTROL
742 job_control
= sysconf (_SC_JOB_CONTROL
);
744 job_control
= 0; /* have to assume the worst */
745 #endif /* _SC_JOB_CONTROL */
746 #endif /* _POSIX_JOB_CONTROL */
747 #endif /* HAVE_TERMIOS */
754 #endif /* TIOCGPGRP */