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,
19 Boston, MA 02111-1307, USA. */
28 #include "gdbthread.h"
30 #include "gdb_string.h"
33 #ifdef HAVE_SYS_SELECT_H
34 #include <sys/select.h>
38 #define PROCESS_GROUP_TYPE pid_t
42 #define PROCESS_GROUP_TYPE int
47 /* This is only used for the ultra. Does it have pid_t? */
48 #define PROCESS_GROUP_TYPE short
50 #define PROCESS_GROUP_TYPE int
54 #ifdef HAVE_SYS_IOCTL_H
55 #include <sys/ioctl.h>
58 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
59 static void handle_sigio (int);
62 extern void _initialize_inflow (void);
64 static void pass_signal (int);
66 static void kill_command (char *, int);
68 static void terminal_ours_1 (int);
70 /* Record terminal status separately for debugger and inferior. */
72 static serial_t stdin_serial
;
74 /* TTY state for the inferior. We save it whenever the inferior stops, and
75 restore it when it resumes. */
76 static serial_ttystate inferior_ttystate
;
78 /* Our own tty state, which we restore every time we need to deal with the
79 terminal. We only set it once, when GDB first starts. The settings of
80 flags which readline saves and restores and unimportant. */
81 static serial_ttystate our_ttystate
;
83 /* fcntl flags for us and the inferior. Saved and restored just like
84 {our,inferior}_ttystate. */
85 static int tflags_inferior
;
86 static int tflags_ours
;
88 #ifdef PROCESS_GROUP_TYPE
89 /* Process group for us and the inferior. Saved and restored just like
90 {our,inferior}_ttystate. */
91 PROCESS_GROUP_TYPE our_process_group
;
92 PROCESS_GROUP_TYPE inferior_process_group
;
95 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
96 inferior only. If we have job control, that takes care of it. If not,
97 we save our handlers in these two variables and set SIGINT and SIGQUIT
100 static void (*sigint_ours
) ();
101 static void (*sigquit_ours
) ();
103 /* The name of the tty (from the `tty' command) that we gave to the inferior
104 when it was last started. */
106 static char *inferior_thisrun_terminal
;
108 /* Nonzero if our terminal settings are in effect. Zero if the
109 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
112 int terminal_is_ours
;
116 yes
, no
, have_not_checked
118 gdb_has_a_terminal_flag
= have_not_checked
;
120 /* Does GDB have a terminal (on stdin)? */
122 gdb_has_a_terminal (void)
124 switch (gdb_has_a_terminal_flag
)
130 case have_not_checked
:
131 /* Get all the current tty settings (including whether we have a tty at
132 all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
133 won't work until the serial_ops_list is initialized. */
136 tflags_ours
= fcntl (0, F_GETFL
, 0);
139 gdb_has_a_terminal_flag
= no
;
140 stdin_serial
= SERIAL_FDOPEN (0);
141 if (stdin_serial
!= NULL
)
143 our_ttystate
= SERIAL_GET_TTY_STATE (stdin_serial
);
145 if (our_ttystate
!= NULL
)
147 gdb_has_a_terminal_flag
= yes
;
149 our_process_group
= tcgetpgrp (0);
152 our_process_group
= getpgrp ();
155 ioctl (0, TIOCGPGRP
, &our_process_group
);
160 return gdb_has_a_terminal_flag
== yes
;
162 /* "Can't happen". */
167 /* Macro for printing errors from ioctl operations */
169 #define OOPSY(what) \
171 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
172 what, strerror (errno))
174 static void terminal_ours_1 (int);
176 /* Initialize the terminal settings we record for the inferior,
177 before we actually run the inferior. */
180 terminal_init_inferior_with_pgrp (int 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 xfree (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 (void)
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. */
219 terminal_inferior (void)
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 (void)
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 (int output_only
)
311 /* Checking inferior_thisrun_terminal is necessary so that
312 if GDB is running in the background, it won't block trying
313 to do the ioctl()'s below. Checking gdb_has_a_terminal
314 avoids attempting all the ioctl's when running in batch. */
315 if (inferior_thisrun_terminal
!= 0 || gdb_has_a_terminal () == 0)
318 if (!terminal_is_ours
)
321 /* Ignore this signal since it will happen when we try to set the
323 void (*osigttou
) () = NULL
;
327 terminal_is_ours
= 1;
331 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
334 if (inferior_ttystate
)
335 xfree (inferior_ttystate
);
336 inferior_ttystate
= SERIAL_GET_TTY_STATE (stdin_serial
);
338 inferior_process_group
= tcgetpgrp (0);
341 inferior_process_group
= getpgrp ();
344 ioctl (0, TIOCGPGRP
, &inferior_process_group
);
347 /* Here we used to set ICANON in our ttystate, but I believe this
348 was an artifact from before when we used readline. Readline sets
349 the tty state when it needs to.
350 FIXME-maybe: However, query() expects non-raw mode and doesn't
351 use readline. Maybe query should use readline (on the other hand,
352 this only matters for HAVE_SGTTY, not termio or termios, I think). */
354 /* Set tty state to our_ttystate. We don't change in our out of raw
355 mode, to avoid flushing input. We need to do the same thing
356 regardless of output_only, because we don't have separate
357 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
358 though, since readline will deal with raw mode when/if it needs to.
361 SERIAL_NOFLUSH_SET_TTY_STATE (stdin_serial
, our_ttystate
,
367 result
= tcsetpgrp (0, our_process_group
);
369 /* This fails on Ultrix with EINVAL if you run the testsuite
370 in the background with nohup, and then log out. GDB never
371 used to check for an error here, so perhaps there are other
372 such situations as well. */
374 fprintf_unfiltered (gdb_stderr
, "[tcsetpgrp failed in terminal_ours: %s]\n",
380 result
= ioctl (0, TIOCSPGRP
, &our_process_group
);
386 signal (SIGTTOU
, osigttou
);
391 signal (SIGINT
, sigint_ours
);
393 signal (SIGQUIT
, sigquit_ours
);
398 tflags_inferior
= fcntl (0, F_GETFL
, 0);
400 /* Is there a reason this is being done twice? It happens both
401 places we use F_SETFL, so I'm inclined to think perhaps there
402 is some reason, however perverse. Perhaps not though... */
403 result
= fcntl (0, F_SETFL
, tflags_ours
);
404 result
= fcntl (0, F_SETFL
, tflags_ours
);
407 result
= result
; /* lint */
413 term_info (char *arg
, int from_tty
)
415 target_terminal_info (arg
, from_tty
);
420 child_terminal_info (char *args
, int from_tty
)
422 if (!gdb_has_a_terminal ())
424 printf_filtered ("This GDB does not control a terminal.\n");
428 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
430 /* First the fcntl flags. */
434 flags
= tflags_inferior
;
436 printf_filtered ("File descriptor flags = ");
439 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
441 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
442 switch (flags
& (O_ACCMODE
))
445 printf_filtered ("O_RDONLY");
448 printf_filtered ("O_WRONLY");
451 printf_filtered ("O_RDWR");
454 flags
&= ~(O_ACCMODE
);
457 if (flags
& O_NONBLOCK
)
458 printf_filtered (" | O_NONBLOCK");
459 flags
&= ~O_NONBLOCK
;
462 #if defined (O_NDELAY)
463 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
464 print it as O_NONBLOCK, which is good cause that is what POSIX
465 has, and the flag will already be cleared by the time we get here. */
466 if (flags
& O_NDELAY
)
467 printf_filtered (" | O_NDELAY");
471 if (flags
& O_APPEND
)
472 printf_filtered (" | O_APPEND");
475 #if defined (O_BINARY)
476 if (flags
& O_BINARY
)
477 printf_filtered (" | O_BINARY");
482 printf_filtered (" | 0x%x", flags
);
483 printf_filtered ("\n");
486 #ifdef PROCESS_GROUP_TYPE
487 printf_filtered ("Process group = %d\n",
488 (int) inferior_process_group
);
491 SERIAL_PRINT_TTY_STATE (stdin_serial
, inferior_ttystate
, gdb_stdout
);
494 /* NEW_TTY_PREFORK is called before forking a new child process,
495 so we can record the state of ttys in the child to be formed.
496 TTYNAME is null if we are to share the terminal with gdb;
497 or points to a string containing the name of the desired tty.
499 NEW_TTY is called in new child processes under Unix, which will
500 become debugger target processes. This actually switches to
501 the terminal specified in the NEW_TTY_PREFORK call. */
504 new_tty_prefork (char *ttyname
)
506 /* Save the name for later, for determining whether we and the child
507 are sharing a tty. */
508 inferior_thisrun_terminal
= ttyname
;
516 if (inferior_thisrun_terminal
== 0)
518 #if !defined(__GO32__) && !defined(_WIN32)
520 /* Disconnect the child process from our controlling terminal. On some
521 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
523 tty
= open ("/dev/tty", O_RDWR
);
528 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
529 ioctl (tty
, TIOCNOTTY
, 0);
531 signal (SIGTTOU
, osigttou
);
535 /* Now open the specified new terminal. */
538 tty
= open (inferior_thisrun_terminal
, O_RDWR
| O_NOCTTY
);
540 tty
= open (inferior_thisrun_terminal
, O_RDWR
);
544 print_sys_errmsg (inferior_thisrun_terminal
, errno
);
548 /* Avoid use of dup2; doesn't exist on all systems. */
566 #endif /* !go32 && !win32 */
569 /* Kill the inferior process. Make us have no inferior. */
573 kill_command (char *arg
, int from_tty
)
575 /* FIXME: This should not really be inferior_pid (or target_has_execution).
576 It should be a distinct flag that indicates that a target is active, cuz
577 some targets don't have processes! */
579 if (inferior_pid
== 0)
580 error ("The program is not being run.");
581 if (!query ("Kill the program being debugged? "))
582 error ("Not confirmed.");
585 init_thread_list (); /* Destroy thread info */
587 /* Killing off the inferior can leave us with a core file. If so,
588 print the state we are left in. */
589 if (target_has_stack
)
591 printf_filtered ("In %s,\n", target_longname
);
592 if (selected_frame
== NULL
)
593 fputs_filtered ("No selected stack frame.\n", gdb_stdout
);
595 print_stack_frame (selected_frame
, selected_frame_level
, 1);
599 /* Call set_sigint_trap when you need to pass a signal on to an attached
600 process when handling SIGINT */
604 pass_signal (int signo
)
607 kill (PIDGET (inferior_pid
), SIGINT
);
611 static void (*osig
) ();
614 set_sigint_trap (void)
616 if (attach_flag
|| inferior_thisrun_terminal
)
618 osig
= (void (*)()) signal (SIGINT
, pass_signal
);
623 clear_sigint_trap (void)
625 if (attach_flag
|| inferior_thisrun_terminal
)
627 signal (SIGINT
, osig
);
631 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
632 static void (*old_sigio
) ();
635 handle_sigio (int signo
)
640 signal (SIGIO
, handle_sigio
);
643 FD_SET (target_activity_fd
, &readfds
);
644 numfds
= select (target_activity_fd
+ 1, &readfds
, NULL
, NULL
, NULL
);
645 if (numfds
>= 0 && FD_ISSET (target_activity_fd
, &readfds
))
648 if ((*target_activity_function
) ())
649 kill (inferior_pid
, SIGINT
);
654 static int old_fcntl_flags
;
657 set_sigio_trap (void)
659 if (target_activity_function
)
661 old_sigio
= (void (*)()) signal (SIGIO
, handle_sigio
);
662 fcntl (target_activity_fd
, F_SETOWN
, getpid ());
663 old_fcntl_flags
= fcntl (target_activity_fd
, F_GETFL
, 0);
664 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
| FASYNC
);
669 clear_sigio_trap (void)
671 if (target_activity_function
)
673 signal (SIGIO
, old_sigio
);
674 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
);
677 #else /* No SIGIO. */
679 set_sigio_trap (void)
681 if (target_activity_function
)
682 internal_error (__FILE__
, __LINE__
, "failed internal consistency check");
686 clear_sigio_trap (void)
688 if (target_activity_function
)
689 internal_error (__FILE__
, __LINE__
, "failed internal consistency check");
691 #endif /* No SIGIO. */
694 /* This is here because this is where we figure out whether we (probably)
695 have job control. Just using job_control only does part of it because
696 setpgid or setpgrp might not exist on a system without job control.
697 It might be considered misplaced (on the other hand, process groups and
698 job control are closely related to ttys).
700 For a more clean implementation, in libiberty, put a setpgid which merely
701 calls setpgrp and a setpgrp which does nothing (any system with job control
702 will have one or the other). */
710 #if defined (NEED_POSIX_SETPGID) || (defined (HAVE_TERMIOS) && defined (HAVE_SETPGID))
711 /* setpgid (0, 0) is supposed to work and mean the same thing as
712 this, but on Ultrix 4.2A it fails with EPERM (and
713 setpgid (getpid (), getpid ()) succeeds). */
714 retval
= setpgid (getpid (), getpid ());
716 #if defined (TIOCGPGRP)
717 #if defined(USG) && !defined(SETPGRP_ARGS)
720 retval
= setpgrp (getpid (), getpid ());
722 #endif /* TIOCGPGRP. */
723 #endif /* NEED_POSIX_SETPGID */
729 _initialize_inflow (void)
731 add_info ("terminal", term_info
,
732 "Print inferior's saved terminal status.");
734 add_com ("kill", class_run
, kill_command
,
735 "Kill execution of program being debugged.");
739 terminal_is_ours
= 1;
741 /* OK, figure out whether we have job control. If neither termios nor
742 sgtty (i.e. termio or go32), leave job_control 0. */
744 #if defined (HAVE_TERMIOS)
745 /* Do all systems with termios have the POSIX way of identifying job
746 control? I hope so. */
747 #ifdef _POSIX_JOB_CONTROL
750 #ifdef _SC_JOB_CONTROL
751 job_control
= sysconf (_SC_JOB_CONTROL
);
753 job_control
= 0; /* have to assume the worst */
754 #endif /* _SC_JOB_CONTROL */
755 #endif /* _POSIX_JOB_CONTROL */
756 #endif /* HAVE_TERMIOS */
763 #endif /* TIOCGPGRP */