1 /* Low level interface to ptrace, for GDB when running under Unix.
2 Copyright 1986, 1987, 1989, 1991, 1992 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
33 #if !defined (HAVE_TERMIOS) && !defined (HAVE_TERMIO) && !defined (HAVE_SGTTY) && !defined (__GO32__)
37 #if defined (HAVE_TERMIOS)
43 #define PROCESS_GROUP_TYPE pid_t
48 /* This is only used for the ultra. Does it have pid_t? */
49 #define PROCESS_GROUP_TYPE short
51 #define PROCESS_GROUP_TYPE int
56 kill_command
PARAMS ((char *, int));
59 terminal_ours_1
PARAMS ((int));
61 /* Nonzero if we are debugging an attached outside process
62 rather than an inferior. */
67 /* Record terminal status separately for debugger and inferior. */
69 static serial_t stdin_serial
;
71 /* TTY state for the inferior. We save it whenever the inferior stops, and
72 restore it when it resumes. */
73 static serial_ttystate inferior_ttystate
;
75 /* Our own tty state, which we restore every time we need to deal with the
76 terminal. We only set it once, when GDB first starts. The settings of
77 flags which readline saves and restores and unimportant. */
78 static serial_ttystate our_ttystate
;
80 /* fcntl flags for us and the inferior. Saved and restored just like
81 {our,inferior}_ttystate. */
82 static int tflags_inferior
;
83 static int tflags_ours
;
85 #ifdef PROCESS_GROUP_TYPE
86 /* Process group for us and the inferior. Saved and restored just like
87 {our,inferior}_ttystate. */
88 PROCESS_GROUP_TYPE our_process_group
;
89 PROCESS_GROUP_TYPE inferior_process_group
;
92 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
93 inferior only. If we have job control, that takes care of it. If not,
94 we save our handlers in these two variables and set SIGINT and SIGQUIT
96 static void (*sigint_ours
) ();
97 static void (*sigquit_ours
) ();
99 /* The name of the tty (from the `tty' command) that we gave to the inferior
100 when it was last started. */
102 static char *inferior_thisrun_terminal
;
104 /* Nonzero if our terminal settings are in effect. Zero if the
105 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
108 static int terminal_is_ours
;
110 enum {yes
, no
, have_not_checked
} gdb_has_a_terminal_flag
= have_not_checked
;
112 /* Does GDB have a terminal (on stdin)? */
114 gdb_has_a_terminal ()
116 switch (gdb_has_a_terminal_flag
)
122 case have_not_checked
:
123 /* Get all the current tty settings (including whether we have a tty at
124 all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
125 won't work until the serial_ops_list is initialized. */
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 ioctl (0, TIOCGPGRP
, &our_process_group
);
149 return gdb_has_a_terminal_flag
== yes
;
151 /* "Can't happen". */
156 /* Macro for printing errors from ioctl operations */
158 #define OOPSY(what) \
160 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
161 what, strerror (errno))
163 static void terminal_ours_1
PARAMS ((int));
165 /* Initialize the terminal settings we record for the inferior,
166 before we actually run the inferior. */
169 terminal_init_inferior ()
171 if (gdb_has_a_terminal ())
173 /* We could just as well copy our_ttystate (if we felt like adding
174 a new function SERIAL_COPY_TTY_STATE). */
175 if (inferior_ttystate
)
176 free (inferior_ttystate
);
177 inferior_ttystate
= SERIAL_GET_TTY_STATE (stdin_serial
);
178 #ifdef PROCESS_GROUP_TYPE
179 inferior_process_group
= inferior_pid
;
182 /* Make sure that next time we call terminal_inferior (which will be
183 before the program runs, as it needs to be), we install the new
185 terminal_is_ours
= 1;
189 /* Put the inferior's terminal settings into effect.
190 This is preparation for starting or resuming the inferior. */
195 if (gdb_has_a_terminal () && terminal_is_ours
196 && inferior_thisrun_terminal
== 0)
201 /* Is there a reason this is being done twice? It happens both
202 places we use F_SETFL, so I'm inclined to think perhaps there
203 is some reason, however perverse. Perhaps not though... */
204 result
= fcntl (0, F_SETFL
, tflags_inferior
);
205 result
= fcntl (0, F_SETFL
, tflags_inferior
);
206 OOPSY ("fcntl F_SETFL");
209 /* Because we were careful to not change in or out of raw mode in
210 terminal_ours, we will not change in our out of raw mode with
211 this call, so we don't flush any input. */
212 result
= SERIAL_SET_TTY_STATE (stdin_serial
, inferior_ttystate
);
213 OOPSY ("setting tty state");
217 sigint_ours
= (void (*) ()) signal (SIGINT
, SIG_IGN
);
218 sigquit_ours
= (void (*) ()) signal (SIGQUIT
, SIG_IGN
);
221 /* If attach_flag is set, we don't know whether we are sharing a
222 terminal with the inferior or not. (attaching a process
223 without a terminal is one case where we do not; attaching a
224 process which we ran from the same shell as GDB via `&' is
225 one case where we do, I think (but perhaps this is not
226 `sharing' in the sense that we need to save and restore tty
227 state)). I don't know if there is any way to tell whether we
228 are sharing a terminal. So what we do is to go through all
229 the saving and restoring of the tty state, but ignore errors
230 setting the process group, which will happen if we are not
231 sharing a terminal). */
236 result
= tcsetpgrp (0, inferior_process_group
);
242 result
= ioctl (0, TIOCSPGRP
, &inferior_process_group
);
249 terminal_is_ours
= 0;
252 /* Put some of our terminal settings into effect,
253 enough to get proper results from our output,
254 but do not change into or out of RAW mode
255 so that no input is discarded.
257 After doing this, either terminal_ours or terminal_inferior
258 should be called to get back to a normal state of affairs. */
261 terminal_ours_for_output ()
266 /* Put our terminal settings into effect.
267 First record the inferior's terminal settings
268 so they can be restored properly later. */
276 /* output_only is not used, and should not be used unless we introduce
277 separate terminal_is_ours and terminal_is_ours_for_output
281 terminal_ours_1 (output_only
)
284 /* Checking inferior_thisrun_terminal is necessary so that
285 if GDB is running in the background, it won't block trying
286 to do the ioctl()'s below. Checking gdb_has_a_terminal
287 avoids attempting all the ioctl's when running in batch. */
288 if (inferior_thisrun_terminal
!= 0 || gdb_has_a_terminal () == 0)
291 if (!terminal_is_ours
)
293 /* Ignore this signal since it will happen when we try to set the
298 terminal_is_ours
= 1;
302 osigttou
= (void (*) ()) signal (SIGTTOU
, SIG_IGN
);
305 if (inferior_ttystate
)
306 free (inferior_ttystate
);
307 inferior_ttystate
= SERIAL_GET_TTY_STATE (stdin_serial
);
309 inferior_process_group
= tcgetpgrp (0);
312 ioctl (0, TIOCGPGRP
, &inferior_process_group
);
315 /* Here we used to set ICANON in our ttystate, but I believe this
316 was an artifact from before when we used readline. Readline sets
317 the tty state when it needs to. */
319 /* Set tty state to our_ttystate. We don't change in our out of raw
320 mode, to avoid flushing input. We need to do the same thing
321 regardless of output_only, because we don't have separate
322 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
323 though, since readline will deal with raw mode when/if it needs to.
325 SERIAL_NOFLUSH_SET_TTY_STATE (stdin_serial
, our_ttystate
,
331 result
= tcsetpgrp (0, our_process_group
);
333 /* This fails on Ultrix with EINVAL if you run the testsuite
334 in the background with nohup, and then log out. GDB never
335 used to check for an error here, so perhaps there are other
336 such situations as well. */
338 fprintf_unfiltered (gdb_stderr
, "[tcsetpgrp failed in terminal_ours: %s]\n",
344 result
= ioctl (0, TIOCSPGRP
, &our_process_group
);
350 signal (SIGTTOU
, osigttou
);
355 signal (SIGINT
, sigint_ours
);
356 signal (SIGQUIT
, sigquit_ours
);
360 tflags_inferior
= fcntl (0, F_GETFL
, 0);
362 /* Is there a reason this is being done twice? It happens both
363 places we use F_SETFL, so I'm inclined to think perhaps there
364 is some reason, however perverse. Perhaps not though... */
365 result
= fcntl (0, F_SETFL
, tflags_ours
);
366 result
= fcntl (0, F_SETFL
, tflags_ours
);
369 result
= result
; /* lint */
375 term_info (arg
, from_tty
)
379 target_terminal_info (arg
, from_tty
);
384 child_terminal_info (args
, from_tty
)
388 if (!gdb_has_a_terminal ())
390 printf_filtered ("This GDB does not control a terminal.\n");
394 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
396 /* First the fcntl flags. */
400 flags
= tflags_inferior
;
402 printf_filtered ("File descriptor flags = ");
405 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
407 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
408 switch (flags
& (O_ACCMODE
))
410 case O_RDONLY
: printf_filtered ("O_RDONLY"); break;
411 case O_WRONLY
: printf_filtered ("O_WRONLY"); break;
412 case O_RDWR
: printf_filtered ("O_RDWR"); break;
414 flags
&= ~(O_ACCMODE
);
417 if (flags
& O_NONBLOCK
)
418 printf_filtered (" | O_NONBLOCK");
419 flags
&= ~O_NONBLOCK
;
422 #if defined (O_NDELAY)
423 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
424 print it as O_NONBLOCK, which is good cause that is what POSIX
425 has, and the flag will already be cleared by the time we get here. */
426 if (flags
& O_NDELAY
)
427 printf_filtered (" | O_NDELAY");
431 if (flags
& O_APPEND
)
432 printf_filtered (" | O_APPEND");
435 #if defined (O_BINARY)
436 if (flags
& O_BINARY
)
437 printf_filtered (" | O_BINARY");
442 printf_filtered (" | 0x%x", flags
);
443 printf_filtered ("\n");
446 #ifdef PROCESS_GROUP_TYPE
447 printf_filtered ("Process group = %d\n", inferior_process_group
);
450 SERIAL_PRINT_TTY_STATE (stdin_serial
, inferior_ttystate
);
453 /* NEW_TTY_PREFORK is called before forking a new child process,
454 so we can record the state of ttys in the child to be formed.
455 TTYNAME is null if we are to share the terminal with gdb;
456 or points to a string containing the name of the desired tty.
458 NEW_TTY is called in new child processes under Unix, which will
459 become debugger target processes. This actually switches to
460 the terminal specified in the NEW_TTY_PREFORK call. */
463 new_tty_prefork (ttyname
)
466 /* Save the name for later, for determining whether we and the child
467 are sharing a tty. */
468 inferior_thisrun_terminal
= ttyname
;
476 if (inferior_thisrun_terminal
== 0)
478 #if !defined(__GO32__)
480 /* Disconnect the child process from our controlling terminal. On some
481 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
483 tty
= open("/dev/tty", O_RDWR
);
488 osigttou
= (void (*)()) signal(SIGTTOU
, SIG_IGN
);
489 ioctl(tty
, TIOCNOTTY
, 0);
491 signal(SIGTTOU
, osigttou
);
495 /* Now open the specified new terminal. */
498 tty
= open(inferior_thisrun_terminal
, O_RDWR
| O_NOCTTY
);
500 tty
= open(inferior_thisrun_terminal
, O_RDWR
);
504 print_sys_errmsg (inferior_thisrun_terminal
, errno
);
508 /* Avoid use of dup2; doesn't exist on all systems. */
510 { close (0); dup (tty
); }
512 { close (1); dup (tty
); }
514 { close (2); dup (tty
); }
520 /* Kill the inferior process. Make us have no inferior. */
524 kill_command (arg
, from_tty
)
528 /* Shouldn't this be target_has_execution? FIXME. */
529 if (inferior_pid
== 0)
530 error ("The program is not being run.");
531 if (!query ("Kill the program being debugged? "))
532 error ("Not confirmed.");
535 init_thread_list(); /* Destroy thread info */
537 /* Killing off the inferior can leave us with a core file. If so,
538 print the state we are left in. */
539 if (target_has_stack
) {
540 printf_filtered ("In %s,\n", current_target
->to_longname
);
541 if (selected_frame
== NULL
)
542 fputs_filtered ("No selected stack frame.\n", gdb_stdout
);
544 print_stack_frame (selected_frame
, selected_frame_level
, 1);
548 /* The inferior process has died. Long live the inferior! */
551 generic_mourn_inferior ()
555 breakpoint_init_inferior ();
556 registers_changed ();
558 #ifdef CLEAR_DEFERRED_STORES
559 /* Delete any pending stores to the inferior... */
560 CLEAR_DEFERRED_STORES
;
564 reinit_frame_cache ();
566 /* It is confusing to the user for ignore counts to stick around
567 from previous runs of the inferior. So clear them. */
568 breakpoint_clear_ignore_counts ();
571 /* Call set_sigint_trap when you need to pass a signal on to an attached
572 process when handling SIGINT */
579 kill (inferior_pid
, SIGINT
);
582 static void (*osig
)();
587 osig
= (void (*) ()) signal (SIGINT
, pass_signal
);
593 signal (SIGINT
, osig
);
599 /* This is here because this is where we figure out whether we (probably)
600 have job control. Just using job_control only does part of it because
601 setpgid or setpgrp might not exist on a system without job control.
602 It might be considered misplaced (on the other hand, process groups and
603 job control are closely related to ttys).
605 For a more clean implementation, in libiberty, put a setpgid which merely
606 calls setpgrp and a setpgrp which does nothing (any system with job control
607 will have one or the other). */
614 #if defined (NEED_POSIX_SETPGID) || defined (HAVE_TERMIOS)
615 /* Do all systems with termios have setpgid? I hope so. */
616 /* setpgid (0, 0) is supposed to work and mean the same thing as
617 this, but on Ultrix 4.2A it fails with EPERM (and
618 setpgid (getpid (), getpid ()) succeeds). */
619 retval
= setpgid (getpid (), getpid ());
621 #if defined (TIOCGPGRP)
622 #if defined(USG) && !defined(SETPGRP_ARGS)
625 retval
= setpgrp (getpid (), getpid ());
627 #endif /* TIOCGPGRP. */
628 #endif /* NEED_POSIX_SETPGID */
634 _initialize_inflow ()
636 add_info ("terminal", term_info
,
637 "Print inferior's saved terminal status.");
639 add_com ("kill", class_run
, kill_command
,
640 "Kill execution of program being debugged.");
644 terminal_is_ours
= 1;
646 /* OK, figure out whether we have job control. If neither termios nor
647 sgtty (i.e. termio or go32), leave job_control 0. */
649 #if defined (HAVE_TERMIOS)
650 /* Do all systems with termios have the POSIX way of identifying job
651 control? I hope so. */
652 #ifdef _POSIX_JOB_CONTROL
655 job_control
= sysconf (_SC_JOB_CONTROL
);
664 #endif /* TIOCGPGRP */