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>
39 #define PROCESS_GROUP_TYPE pid_t
43 #define PROCESS_GROUP_TYPE int
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
55 #ifdef HAVE_SYS_IOCTL_H
56 #include <sys/ioctl.h>
59 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
60 static void handle_sigio (int);
63 extern void _initialize_inflow (void);
65 static void pass_signal (int);
67 static void kill_command (char *, int);
69 static void terminal_ours_1 (int);
71 /* Record terminal status separately for debugger and inferior. */
73 static struct serial *stdin_serial;
75 /* TTY state for the inferior. We save it whenever the inferior stops, and
76 restore it when it resumes. */
77 static serial_ttystate inferior_ttystate;
79 /* Our own tty state, which we restore every time we need to deal with the
80 terminal. We only set it once, when GDB first starts. The settings of
81 flags which readline saves and restores and unimportant. */
82 static serial_ttystate our_ttystate;
84 /* fcntl flags for us and the inferior. Saved and restored just like
85 {our,inferior}_ttystate. */
86 static int tflags_inferior;
87 static int tflags_ours;
89 #ifdef PROCESS_GROUP_TYPE
90 /* Process group for us and the inferior. Saved and restored just like
91 {our,inferior}_ttystate. */
92 PROCESS_GROUP_TYPE our_process_group;
93 PROCESS_GROUP_TYPE inferior_process_group;
96 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
97 inferior only. If we have job control, that takes care of it. If not,
98 we save our handlers in these two variables and set SIGINT and SIGQUIT
101 static void (*sigint_ours) ();
102 static void (*sigquit_ours) ();
104 /* The name of the tty (from the `tty' command) that we gave to the inferior
105 when it was last started. */
107 static char *inferior_thisrun_terminal;
109 /* Nonzero if our terminal settings are in effect. Zero if the
110 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
113 int terminal_is_ours;
117 yes, no, have_not_checked
119 gdb_has_a_terminal_flag = have_not_checked;
121 /* Does GDB have a terminal (on stdin)? */
123 gdb_has_a_terminal (void)
125 switch (gdb_has_a_terminal_flag)
131 case have_not_checked:
132 /* Get all the current tty settings (including whether we have a
133 tty at all!). Can't do this in _initialize_inflow because
134 serial_fdopen() won't work until the serial_ops_list is
138 tflags_ours = fcntl (0, F_GETFL, 0);
141 gdb_has_a_terminal_flag = no;
142 stdin_serial = serial_fdopen (0);
143 if (stdin_serial != NULL)
145 our_ttystate = serial_get_tty_state (stdin_serial);
147 if (our_ttystate != NULL)
149 gdb_has_a_terminal_flag = yes;
151 our_process_group = tcgetpgrp (0);
154 our_process_group = getpgrp ();
157 ioctl (0, TIOCGPGRP, &our_process_group);
162 return gdb_has_a_terminal_flag == yes;
164 /* "Can't happen". */
169 /* Macro for printing errors from ioctl operations */
171 #define OOPSY(what) \
173 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
174 what, safe_strerror (errno))
176 static void terminal_ours_1 (int);
178 /* Initialize the terminal settings we record for the inferior,
179 before we actually run the inferior. */
182 terminal_init_inferior_with_pgrp (int pgrp)
184 if (gdb_has_a_terminal ())
186 /* We could just as well copy our_ttystate (if we felt like
187 adding a new function serial_copy_tty_state()). */
188 if (inferior_ttystate)
189 xfree (inferior_ttystate);
190 inferior_ttystate = serial_get_tty_state (stdin_serial);
192 #ifdef PROCESS_GROUP_TYPE
193 inferior_process_group = pgrp;
196 /* Make sure that next time we call terminal_inferior (which will be
197 before the program runs, as it needs to be), we install the new
199 terminal_is_ours = 1;
203 /* Save the terminal settings again. This is necessary for the TUI
204 when it switches to TUI or non-TUI mode; curses changes the terminal
205 and gdb must be able to restore it correctly. */
208 terminal_save_ours ()
210 if (gdb_has_a_terminal ())
212 /* We could just as well copy our_ttystate (if we felt like adding
213 a new function serial_copy_tty_state). */
215 xfree (our_ttystate);
216 our_ttystate = serial_get_tty_state (stdin_serial);
221 terminal_init_inferior (void)
223 #ifdef PROCESS_GROUP_TYPE
224 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
225 debugging target with a version of target_terminal_init_inferior which
226 passes in the process group to a generic routine which does all the work
227 (and the non-threaded child_terminal_init_inferior can just pass in
228 inferior_ptid to the same routine). */
229 /* We assume INFERIOR_PID is also the child's process group. */
230 terminal_init_inferior_with_pgrp (PIDGET (inferior_ptid));
231 #endif /* PROCESS_GROUP_TYPE */
234 /* Put the inferior's terminal settings into effect.
235 This is preparation for starting or resuming the inferior. */
238 terminal_inferior (void)
240 if (gdb_has_a_terminal () && terminal_is_ours
241 && inferior_thisrun_terminal == 0)
246 /* Is there a reason this is being done twice? It happens both
247 places we use F_SETFL, so I'm inclined to think perhaps there
248 is some reason, however perverse. Perhaps not though... */
249 result = fcntl (0, F_SETFL, tflags_inferior);
250 result = fcntl (0, F_SETFL, tflags_inferior);
251 OOPSY ("fcntl F_SETFL");
254 /* Because we were careful to not change in or out of raw mode in
255 terminal_ours, we will not change in our out of raw mode with
256 this call, so we don't flush any input. */
257 result = serial_set_tty_state (stdin_serial, inferior_ttystate);
258 OOPSY ("setting tty state");
262 sigint_ours = (void (*)()) signal (SIGINT, SIG_IGN);
264 sigquit_ours = (void (*)()) signal (SIGQUIT, SIG_IGN);
268 /* If attach_flag is set, we don't know whether we are sharing a
269 terminal with the inferior or not. (attaching a process
270 without a terminal is one case where we do not; attaching a
271 process which we ran from the same shell as GDB via `&' is
272 one case where we do, I think (but perhaps this is not
273 `sharing' in the sense that we need to save and restore tty
274 state)). I don't know if there is any way to tell whether we
275 are sharing a terminal. So what we do is to go through all
276 the saving and restoring of the tty state, but ignore errors
277 setting the process group, which will happen if we are not
278 sharing a terminal). */
283 result = tcsetpgrp (0, inferior_process_group);
289 result = ioctl (0, TIOCSPGRP, &inferior_process_group);
296 terminal_is_ours = 0;
299 /* Put some of our terminal settings into effect,
300 enough to get proper results from our output,
301 but do not change into or out of RAW mode
302 so that no input is discarded.
304 After doing this, either terminal_ours or terminal_inferior
305 should be called to get back to a normal state of affairs. */
308 terminal_ours_for_output (void)
313 /* Put our terminal settings into effect.
314 First record the inferior's terminal settings
315 so they can be restored properly later. */
323 /* output_only is not used, and should not be used unless we introduce
324 separate terminal_is_ours and terminal_is_ours_for_output
328 terminal_ours_1 (int output_only)
330 /* Checking inferior_thisrun_terminal is necessary so that
331 if GDB is running in the background, it won't block trying
332 to do the ioctl()'s below. Checking gdb_has_a_terminal
333 avoids attempting all the ioctl's when running in batch. */
334 if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)
337 if (!terminal_is_ours)
340 /* Ignore this signal since it will happen when we try to set the
342 void (*osigttou) () = NULL;
346 terminal_is_ours = 1;
350 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
353 if (inferior_ttystate)
354 xfree (inferior_ttystate);
355 inferior_ttystate = serial_get_tty_state (stdin_serial);
357 inferior_process_group = tcgetpgrp (0);
360 inferior_process_group = getpgrp ();
363 ioctl (0, TIOCGPGRP, &inferior_process_group);
366 /* Here we used to set ICANON in our ttystate, but I believe this
367 was an artifact from before when we used readline. Readline sets
368 the tty state when it needs to.
369 FIXME-maybe: However, query() expects non-raw mode and doesn't
370 use readline. Maybe query should use readline (on the other hand,
371 this only matters for HAVE_SGTTY, not termio or termios, I think). */
373 /* Set tty state to our_ttystate. We don't change in our out of raw
374 mode, to avoid flushing input. We need to do the same thing
375 regardless of output_only, because we don't have separate
376 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
377 though, since readline will deal with raw mode when/if it needs to.
380 serial_noflush_set_tty_state (stdin_serial, our_ttystate,
386 result = tcsetpgrp (0, our_process_group);
388 /* This fails on Ultrix with EINVAL if you run the testsuite
389 in the background with nohup, and then log out. GDB never
390 used to check for an error here, so perhaps there are other
391 such situations as well. */
393 fprintf_unfiltered (gdb_stderr, "[tcsetpgrp failed in terminal_ours: %s]\n",
394 safe_strerror (errno));
399 result = ioctl (0, TIOCSPGRP, &our_process_group);
405 signal (SIGTTOU, osigttou);
410 signal (SIGINT, sigint_ours);
412 signal (SIGQUIT, sigquit_ours);
417 tflags_inferior = fcntl (0, F_GETFL, 0);
419 /* Is there a reason this is being done twice? It happens both
420 places we use F_SETFL, so I'm inclined to think perhaps there
421 is some reason, however perverse. Perhaps not though... */
422 result = fcntl (0, F_SETFL, tflags_ours);
423 result = fcntl (0, F_SETFL, tflags_ours);
426 result = result; /* lint */
432 term_info (char *arg, int from_tty)
434 target_terminal_info (arg, from_tty);
439 child_terminal_info (char *args, int from_tty)
441 if (!gdb_has_a_terminal ())
443 printf_filtered ("This GDB does not control a terminal.\n");
447 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
449 /* First the fcntl flags. */
453 flags = tflags_inferior;
455 printf_filtered ("File descriptor flags = ");
458 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
460 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
461 switch (flags & (O_ACCMODE))
464 printf_filtered ("O_RDONLY");
467 printf_filtered ("O_WRONLY");
470 printf_filtered ("O_RDWR");
473 flags &= ~(O_ACCMODE);
476 if (flags & O_NONBLOCK)
477 printf_filtered (" | O_NONBLOCK");
478 flags &= ~O_NONBLOCK;
481 #if defined (O_NDELAY)
482 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
483 print it as O_NONBLOCK, which is good cause that is what POSIX
484 has, and the flag will already be cleared by the time we get here. */
485 if (flags & O_NDELAY)
486 printf_filtered (" | O_NDELAY");
490 if (flags & O_APPEND)
491 printf_filtered (" | O_APPEND");
494 #if defined (O_BINARY)
495 if (flags & O_BINARY)
496 printf_filtered (" | O_BINARY");
501 printf_filtered (" | 0x%x", flags);
502 printf_filtered ("\n");
505 #ifdef PROCESS_GROUP_TYPE
506 printf_filtered ("Process group = %d\n",
507 (int) inferior_process_group);
510 serial_print_tty_state (stdin_serial, inferior_ttystate, gdb_stdout);
513 /* NEW_TTY_PREFORK is called before forking a new child process,
514 so we can record the state of ttys in the child to be formed.
515 TTYNAME is null if we are to share the terminal with gdb;
516 or points to a string containing the name of the desired tty.
518 NEW_TTY is called in new child processes under Unix, which will
519 become debugger target processes. This actually switches to
520 the terminal specified in the NEW_TTY_PREFORK call. */
523 new_tty_prefork (char *ttyname)
525 /* Save the name for later, for determining whether we and the child
526 are sharing a tty. */
527 inferior_thisrun_terminal = ttyname;
535 if (inferior_thisrun_terminal == 0)
537 #if !defined(__GO32__) && !defined(_WIN32)
539 /* Disconnect the child process from our controlling terminal. On some
540 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
542 tty = open ("/dev/tty", O_RDWR);
547 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
548 ioctl (tty, TIOCNOTTY, 0);
550 signal (SIGTTOU, osigttou);
554 /* Now open the specified new terminal. */
557 tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
559 tty = open (inferior_thisrun_terminal, O_RDWR);
563 print_sys_errmsg (inferior_thisrun_terminal, errno);
567 /* Avoid use of dup2; doesn't exist on all systems. */
585 #endif /* !go32 && !win32 */
588 /* Kill the inferior process. Make us have no inferior. */
592 kill_command (char *arg, int from_tty)
594 /* FIXME: This should not really be inferior_ptid (or target_has_execution).
595 It should be a distinct flag that indicates that a target is active, cuz
596 some targets don't have processes! */
598 if (ptid_equal (inferior_ptid, null_ptid))
599 error ("The program is not being run.");
600 if (!query ("Kill the program being debugged? "))
601 error ("Not confirmed.");
604 init_thread_list (); /* Destroy thread info */
606 /* Killing off the inferior can leave us with a core file. If so,
607 print the state we are left in. */
608 if (target_has_stack)
610 printf_filtered ("In %s,\n", target_longname);
611 if (selected_frame == NULL)
612 fputs_filtered ("No selected stack frame.\n", gdb_stdout);
614 print_stack_frame (selected_frame,
615 frame_relative_level (selected_frame), 1);
619 /* Call set_sigint_trap when you need to pass a signal on to an attached
620 process when handling SIGINT */
624 pass_signal (int signo)
627 kill (PIDGET (inferior_ptid), SIGINT);
631 static void (*osig) ();
634 set_sigint_trap (void)
636 if (attach_flag || inferior_thisrun_terminal)
638 osig = (void (*)()) signal (SIGINT, pass_signal);
643 clear_sigint_trap (void)
645 if (attach_flag || inferior_thisrun_terminal)
647 signal (SIGINT, osig);
651 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
652 static void (*old_sigio) ();
655 handle_sigio (int signo)
660 signal (SIGIO, handle_sigio);
663 FD_SET (target_activity_fd, &readfds);
664 numfds = select (target_activity_fd + 1, &readfds, NULL, NULL, NULL);
665 if (numfds >= 0 && FD_ISSET (target_activity_fd, &readfds))
668 if ((*target_activity_function) ())
669 kill (PIDGET (inferior_ptid), SIGINT);
674 static int old_fcntl_flags;
677 set_sigio_trap (void)
679 if (target_activity_function)
681 old_sigio = (void (*)()) signal (SIGIO, handle_sigio);
682 fcntl (target_activity_fd, F_SETOWN, getpid ());
683 old_fcntl_flags = fcntl (target_activity_fd, F_GETFL, 0);
684 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags | FASYNC);
689 clear_sigio_trap (void)
691 if (target_activity_function)
693 signal (SIGIO, old_sigio);
694 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags);
697 #else /* No SIGIO. */
699 set_sigio_trap (void)
701 if (target_activity_function)
702 internal_error (__FILE__, __LINE__, "failed internal consistency check");
706 clear_sigio_trap (void)
708 if (target_activity_function)
709 internal_error (__FILE__, __LINE__, "failed internal consistency check");
711 #endif /* No SIGIO. */
714 /* This is here because this is where we figure out whether we (probably)
715 have job control. Just using job_control only does part of it because
716 setpgid or setpgrp might not exist on a system without job control.
717 It might be considered misplaced (on the other hand, process groups and
718 job control are closely related to ttys).
720 For a more clean implementation, in libiberty, put a setpgid which merely
721 calls setpgrp and a setpgrp which does nothing (any system with job control
722 will have one or the other). */
730 #if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
732 /* The call setpgid (0, 0) is supposed to work and mean the same
733 thing as this, but on Ultrix 4.2A it fails with EPERM (and
734 setpgid (getpid (), getpid ()) succeeds). */
735 retval = setpgid (getpid (), getpid ());
741 retval = setpgrp (getpid (), getpid ());
743 #endif /* HAVE_SETPGRP */
744 #endif /* HAVE_SETPGID */
745 #endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
752 _initialize_inflow (void)
754 add_info ("terminal", term_info,
755 "Print inferior's saved terminal status.");
757 add_com ("kill", class_run, kill_command,
758 "Kill execution of program being debugged.");
760 inferior_ptid = null_ptid;
762 terminal_is_ours = 1;
764 /* OK, figure out whether we have job control. If neither termios nor
765 sgtty (i.e. termio or go32), leave job_control 0. */
767 #if defined (HAVE_TERMIOS)
768 /* Do all systems with termios have the POSIX way of identifying job
769 control? I hope so. */
770 #ifdef _POSIX_JOB_CONTROL
773 #ifdef _SC_JOB_CONTROL
774 job_control = sysconf (_SC_JOB_CONTROL);
776 job_control = 0; /* have to assume the worst */
777 #endif /* _SC_JOB_CONTROL */
778 #endif /* _POSIX_JOB_CONTROL */
779 #endif /* HAVE_TERMIOS */
786 #endif /* TIOCGPGRP */