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. */
29 #include "gdbthread.h"
31 #include "gdb_string.h"
37 #ifdef HAVE_SYS_SELECT_H
38 #include <sys/select.h>
42 #define PROCESS_GROUP_TYPE pid_t
46 #define PROCESS_GROUP_TYPE int
51 /* This is only used for the ultra. Does it have pid_t? */
52 #define PROCESS_GROUP_TYPE short
54 #define PROCESS_GROUP_TYPE int
58 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
60 handle_sigio PARAMS ((int));
63 extern void _initialize_inflow PARAMS ((void));
66 pass_signal PARAMS ((int));
69 kill_command PARAMS ((char *, int));
72 terminal_ours_1 PARAMS ((int));
74 /* Record terminal status separately for debugger and inferior. */
76 static serial_t stdin_serial;
78 /* TTY state for the inferior. We save it whenever the inferior stops, and
79 restore it when it resumes. */
80 static serial_ttystate inferior_ttystate;
82 /* Our own tty state, which we restore every time we need to deal with the
83 terminal. We only set it once, when GDB first starts. The settings of
84 flags which readline saves and restores and unimportant. */
85 static serial_ttystate our_ttystate;
87 /* fcntl flags for us and the inferior. Saved and restored just like
88 {our,inferior}_ttystate. */
89 static int tflags_inferior;
90 static int tflags_ours;
92 #ifdef PROCESS_GROUP_TYPE
93 /* Process group for us and the inferior. Saved and restored just like
94 {our,inferior}_ttystate. */
95 PROCESS_GROUP_TYPE our_process_group;
96 PROCESS_GROUP_TYPE inferior_process_group;
99 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
100 inferior only. If we have job control, that takes care of it. If not,
101 we save our handlers in these two variables and set SIGINT and SIGQUIT
104 static void (*sigint_ours) ();
105 static void (*sigquit_ours) ();
107 /* The name of the tty (from the `tty' command) that we gave to the inferior
108 when it was last started. */
110 static char *inferior_thisrun_terminal;
112 /* Nonzero if our terminal settings are in effect. Zero if the
113 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
116 int terminal_is_ours;
120 yes, no, have_not_checked
122 gdb_has_a_terminal_flag = have_not_checked;
124 /* Does GDB have a terminal (on stdin)? */
126 gdb_has_a_terminal ()
128 switch (gdb_has_a_terminal_flag)
134 case have_not_checked:
135 /* Get all the current tty settings (including whether we have a tty at
136 all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
137 won't work until the serial_ops_list is initialized. */
140 tflags_ours = fcntl (0, F_GETFL, 0);
143 gdb_has_a_terminal_flag = no;
144 stdin_serial = SERIAL_FDOPEN (0);
145 if (stdin_serial != NULL)
147 our_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
149 if (our_ttystate != NULL)
151 gdb_has_a_terminal_flag = yes;
153 our_process_group = tcgetpgrp (0);
156 our_process_group = getpgrp ();
159 ioctl (0, TIOCGPGRP, &our_process_group);
164 return gdb_has_a_terminal_flag == yes;
166 /* "Can't happen". */
171 /* Macro for printing errors from ioctl operations */
173 #define OOPSY(what) \
175 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
176 what, strerror (errno))
178 static void terminal_ours_1 PARAMS ((int));
180 /* Initialize the terminal settings we record for the inferior,
181 before we actually run the inferior. */
184 terminal_init_inferior_with_pgrp (pgrp)
187 if (gdb_has_a_terminal ())
189 /* We could just as well copy our_ttystate (if we felt like adding
190 a new function SERIAL_COPY_TTY_STATE). */
191 if (inferior_ttystate)
192 free (inferior_ttystate);
193 inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
195 #ifdef PROCESS_GROUP_TYPE
196 inferior_process_group = pgrp;
199 /* Make sure that next time we call terminal_inferior (which will be
200 before the program runs, as it needs to be), we install the new
202 terminal_is_ours = 1;
207 terminal_init_inferior ()
209 #ifdef PROCESS_GROUP_TYPE
210 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
211 debugging target with a version of target_terminal_init_inferior which
212 passes in the process group to a generic routine which does all the work
213 (and the non-threaded child_terminal_init_inferior can just pass in
214 inferior_pid to the same routine). */
215 /* We assume INFERIOR_PID is also the child's process group. */
216 terminal_init_inferior_with_pgrp (PIDGET (inferior_pid));
217 #endif /* PROCESS_GROUP_TYPE */
220 /* Put the inferior's terminal settings into effect.
221 This is preparation for starting or resuming the inferior. */
226 if (gdb_has_a_terminal () && terminal_is_ours
227 && inferior_thisrun_terminal == 0)
232 /* Is there a reason this is being done twice? It happens both
233 places we use F_SETFL, so I'm inclined to think perhaps there
234 is some reason, however perverse. Perhaps not though... */
235 result = fcntl (0, F_SETFL, tflags_inferior);
236 result = fcntl (0, F_SETFL, tflags_inferior);
237 OOPSY ("fcntl F_SETFL");
240 /* Because we were careful to not change in or out of raw mode in
241 terminal_ours, we will not change in our out of raw mode with
242 this call, so we don't flush any input. */
243 result = SERIAL_SET_TTY_STATE (stdin_serial, inferior_ttystate);
244 OOPSY ("setting tty state");
248 sigint_ours = (void (*)()) signal (SIGINT, SIG_IGN);
250 sigquit_ours = (void (*)()) signal (SIGQUIT, SIG_IGN);
254 /* If attach_flag is set, we don't know whether we are sharing a
255 terminal with the inferior or not. (attaching a process
256 without a terminal is one case where we do not; attaching a
257 process which we ran from the same shell as GDB via `&' is
258 one case where we do, I think (but perhaps this is not
259 `sharing' in the sense that we need to save and restore tty
260 state)). I don't know if there is any way to tell whether we
261 are sharing a terminal. So what we do is to go through all
262 the saving and restoring of the tty state, but ignore errors
263 setting the process group, which will happen if we are not
264 sharing a terminal). */
269 result = tcsetpgrp (0, inferior_process_group);
275 result = ioctl (0, TIOCSPGRP, &inferior_process_group);
282 terminal_is_ours = 0;
285 /* Put some of our terminal settings into effect,
286 enough to get proper results from our output,
287 but do not change into or out of RAW mode
288 so that no input is discarded.
290 After doing this, either terminal_ours or terminal_inferior
291 should be called to get back to a normal state of affairs. */
294 terminal_ours_for_output ()
299 /* Put our terminal settings into effect.
300 First record the inferior's terminal settings
301 so they can be restored properly later. */
309 /* output_only is not used, and should not be used unless we introduce
310 separate terminal_is_ours and terminal_is_ours_for_output
314 terminal_ours_1 (output_only)
317 /* Checking inferior_thisrun_terminal is necessary so that
318 if GDB is running in the background, it won't block trying
319 to do the ioctl()'s below. Checking gdb_has_a_terminal
320 avoids attempting all the ioctl's when running in batch. */
321 if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)
324 if (!terminal_is_ours)
326 /* Ignore this signal since it will happen when we try to set the
331 terminal_is_ours = 1;
335 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
338 if (inferior_ttystate)
339 free (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",
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 */
417 term_info (arg, from_tty)
421 target_terminal_info (arg, from_tty);
426 child_terminal_info (args, 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", inferior_process_group);
498 SERIAL_PRINT_TTY_STATE (stdin_serial, inferior_ttystate);
501 /* NEW_TTY_PREFORK is called before forking a new child process,
502 so we can record the state of ttys in the child to be formed.
503 TTYNAME is null if we are to share the terminal with gdb;
504 or points to a string containing the name of the desired tty.
506 NEW_TTY is called in new child processes under Unix, which will
507 become debugger target processes. This actually switches to
508 the terminal specified in the NEW_TTY_PREFORK call. */
511 new_tty_prefork (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. */
546 tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
548 tty = open (inferior_thisrun_terminal, O_RDWR);
552 print_sys_errmsg (inferior_thisrun_terminal, errno);
556 /* Avoid use of dup2; doesn't exist on all systems. */
574 #endif /* !go32 && !win32 */
577 /* Kill the inferior process. Make us have no inferior. */
581 kill_command (arg, from_tty)
585 /* FIXME: This should not really be inferior_pid (or target_has_execution).
586 It should be a distinct flag that indicates that a target is active, cuz
587 some targets don't have processes! */
589 if (inferior_pid == 0)
590 error ("The program is not being run.");
591 if (!query ("Kill the program being debugged? "))
592 error ("Not confirmed.");
595 init_thread_list (); /* Destroy thread info */
597 /* Killing off the inferior can leave us with a core file. If so,
598 print the state we are left in. */
599 if (target_has_stack)
601 printf_filtered ("In %s,\n", target_longname);
602 if (selected_frame == NULL)
603 fputs_filtered ("No selected stack frame.\n", gdb_stdout);
605 print_stack_frame (selected_frame, selected_frame_level, 1);
609 /* Call set_sigint_trap when you need to pass a signal on to an attached
610 process when handling SIGINT */
618 kill (PIDGET (inferior_pid), SIGINT);
622 static void (*osig) ();
627 if (attach_flag || inferior_thisrun_terminal)
629 osig = (void (*)()) signal (SIGINT, pass_signal);
636 if (attach_flag || inferior_thisrun_terminal)
638 signal (SIGINT, osig);
642 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
643 static void (*old_sigio) ();
652 signal (SIGIO, handle_sigio);
655 FD_SET (target_activity_fd, &readfds);
656 numfds = select (target_activity_fd + 1, &readfds, NULL, NULL, NULL);
657 if (numfds >= 0 && FD_ISSET (target_activity_fd, &readfds))
660 if ((*target_activity_function) ())
661 kill (inferior_pid, SIGINT);
666 static int old_fcntl_flags;
671 if (target_activity_function)
673 old_sigio = (void (*)()) signal (SIGIO, handle_sigio);
674 fcntl (target_activity_fd, F_SETOWN, getpid ());
675 old_fcntl_flags = fcntl (target_activity_fd, F_GETFL, 0);
676 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags | FASYNC);
683 if (target_activity_function)
685 signal (SIGIO, old_sigio);
686 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags);
689 #else /* No SIGIO. */
693 if (target_activity_function)
700 if (target_activity_function)
703 #endif /* No SIGIO. */
706 /* This is here because this is where we figure out whether we (probably)
707 have job control. Just using job_control only does part of it because
708 setpgid or setpgrp might not exist on a system without job control.
709 It might be considered misplaced (on the other hand, process groups and
710 job control are closely related to ttys).
712 For a more clean implementation, in libiberty, put a setpgid which merely
713 calls setpgrp and a setpgrp which does nothing (any system with job control
714 will have one or the other). */
722 #if defined (NEED_POSIX_SETPGID) || (defined (HAVE_TERMIOS) && defined (HAVE_SETPGID))
723 /* setpgid (0, 0) is supposed to work and mean the same thing as
724 this, but on Ultrix 4.2A it fails with EPERM (and
725 setpgid (getpid (), getpid ()) succeeds). */
726 retval = setpgid (getpid (), getpid ());
728 #if defined (TIOCGPGRP)
729 #if defined(USG) && !defined(SETPGRP_ARGS)
732 retval = setpgrp (getpid (), getpid ());
734 #endif /* TIOCGPGRP. */
735 #endif /* NEED_POSIX_SETPGID */
741 _initialize_inflow ()
743 add_info ("terminal", term_info,
744 "Print inferior's saved terminal status.");
746 add_com ("kill", class_run, kill_command,
747 "Kill execution of program being debugged.");
751 terminal_is_ours = 1;
753 /* OK, figure out whether we have job control. If neither termios nor
754 sgtty (i.e. termio or go32), leave job_control 0. */
756 #if defined (HAVE_TERMIOS)
757 /* Do all systems with termios have the POSIX way of identifying job
758 control? I hope so. */
759 #ifdef _POSIX_JOB_CONTROL
762 #ifdef _SC_JOB_CONTROL
763 job_control = sysconf (_SC_JOB_CONTROL);
765 job_control = 0; /* have to assume the worst */
766 #endif /* _SC_JOB_CONTROL */
767 #endif /* _POSIX_JOB_CONTROL */
768 #endif /* HAVE_TERMIOS */
775 #endif /* TIOCGPGRP */