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"
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 serial_t 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 ()
125 switch (gdb_has_a_terminal_flag)
131 case have_not_checked:
132 /* Get all the current tty settings (including whether we have a tty at
133 all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
134 won't work until the serial_ops_list is initialized. */
137 tflags_ours = fcntl (0, F_GETFL, 0);
140 gdb_has_a_terminal_flag = no;
141 stdin_serial = SERIAL_FDOPEN (0);
142 if (stdin_serial != NULL)
144 our_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
146 if (our_ttystate != NULL)
148 gdb_has_a_terminal_flag = yes;
150 our_process_group = tcgetpgrp (0);
153 our_process_group = getpgrp ();
156 ioctl (0, TIOCGPGRP, &our_process_group);
161 return gdb_has_a_terminal_flag == yes;
163 /* "Can't happen". */
168 /* Macro for printing errors from ioctl operations */
170 #define OOPSY(what) \
172 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
173 what, strerror (errno))
175 static void terminal_ours_1 (int);
177 /* Initialize the terminal settings we record for the inferior,
178 before we actually run the inferior. */
181 terminal_init_inferior_with_pgrp (pgrp)
184 if (gdb_has_a_terminal ())
186 /* We could just as well copy our_ttystate (if we felt like adding
187 a new function SERIAL_COPY_TTY_STATE). */
188 if (inferior_ttystate)
189 free (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;
204 terminal_init_inferior ()
206 #ifdef PROCESS_GROUP_TYPE
207 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
208 debugging target with a version of target_terminal_init_inferior which
209 passes in the process group to a generic routine which does all the work
210 (and the non-threaded child_terminal_init_inferior can just pass in
211 inferior_pid to the same routine). */
212 /* We assume INFERIOR_PID is also the child's process group. */
213 terminal_init_inferior_with_pgrp (PIDGET (inferior_pid));
214 #endif /* PROCESS_GROUP_TYPE */
217 /* Put the inferior's terminal settings into effect.
218 This is preparation for starting or resuming the inferior. */
223 if (gdb_has_a_terminal () && terminal_is_ours
224 && inferior_thisrun_terminal == 0)
229 /* Is there a reason this is being done twice? It happens both
230 places we use F_SETFL, so I'm inclined to think perhaps there
231 is some reason, however perverse. Perhaps not though... */
232 result = fcntl (0, F_SETFL, tflags_inferior);
233 result = fcntl (0, F_SETFL, tflags_inferior);
234 OOPSY ("fcntl F_SETFL");
237 /* Because we were careful to not change in or out of raw mode in
238 terminal_ours, we will not change in our out of raw mode with
239 this call, so we don't flush any input. */
240 result = SERIAL_SET_TTY_STATE (stdin_serial, inferior_ttystate);
241 OOPSY ("setting tty state");
245 sigint_ours = (void (*)()) signal (SIGINT, SIG_IGN);
247 sigquit_ours = (void (*)()) signal (SIGQUIT, SIG_IGN);
251 /* If attach_flag is set, we don't know whether we are sharing a
252 terminal with the inferior or not. (attaching a process
253 without a terminal is one case where we do not; attaching a
254 process which we ran from the same shell as GDB via `&' is
255 one case where we do, I think (but perhaps this is not
256 `sharing' in the sense that we need to save and restore tty
257 state)). I don't know if there is any way to tell whether we
258 are sharing a terminal. So what we do is to go through all
259 the saving and restoring of the tty state, but ignore errors
260 setting the process group, which will happen if we are not
261 sharing a terminal). */
266 result = tcsetpgrp (0, inferior_process_group);
272 result = ioctl (0, TIOCSPGRP, &inferior_process_group);
279 terminal_is_ours = 0;
282 /* Put some of our terminal settings into effect,
283 enough to get proper results from our output,
284 but do not change into or out of RAW mode
285 so that no input is discarded.
287 After doing this, either terminal_ours or terminal_inferior
288 should be called to get back to a normal state of affairs. */
291 terminal_ours_for_output ()
296 /* Put our terminal settings into effect.
297 First record the inferior's terminal settings
298 so they can be restored properly later. */
306 /* output_only is not used, and should not be used unless we introduce
307 separate terminal_is_ours and terminal_is_ours_for_output
311 terminal_ours_1 (output_only)
314 /* Checking inferior_thisrun_terminal is necessary so that
315 if GDB is running in the background, it won't block trying
316 to do the ioctl()'s below. Checking gdb_has_a_terminal
317 avoids attempting all the ioctl's when running in batch. */
318 if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)
321 if (!terminal_is_ours)
323 /* Ignore this signal since it will happen when we try to set the
328 terminal_is_ours = 1;
332 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
335 if (inferior_ttystate)
336 free (inferior_ttystate);
337 inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
339 inferior_process_group = tcgetpgrp (0);
342 inferior_process_group = getpgrp ();
345 ioctl (0, TIOCGPGRP, &inferior_process_group);
348 /* Here we used to set ICANON in our ttystate, but I believe this
349 was an artifact from before when we used readline. Readline sets
350 the tty state when it needs to.
351 FIXME-maybe: However, query() expects non-raw mode and doesn't
352 use readline. Maybe query should use readline (on the other hand,
353 this only matters for HAVE_SGTTY, not termio or termios, I think). */
355 /* Set tty state to our_ttystate. We don't change in our out of raw
356 mode, to avoid flushing input. We need to do the same thing
357 regardless of output_only, because we don't have separate
358 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
359 though, since readline will deal with raw mode when/if it needs to.
362 SERIAL_NOFLUSH_SET_TTY_STATE (stdin_serial, our_ttystate,
368 result = tcsetpgrp (0, our_process_group);
370 /* This fails on Ultrix with EINVAL if you run the testsuite
371 in the background with nohup, and then log out. GDB never
372 used to check for an error here, so perhaps there are other
373 such situations as well. */
375 fprintf_unfiltered (gdb_stderr, "[tcsetpgrp failed in terminal_ours: %s]\n",
381 result = ioctl (0, TIOCSPGRP, &our_process_group);
387 signal (SIGTTOU, osigttou);
392 signal (SIGINT, sigint_ours);
394 signal (SIGQUIT, sigquit_ours);
399 tflags_inferior = fcntl (0, F_GETFL, 0);
401 /* Is there a reason this is being done twice? It happens both
402 places we use F_SETFL, so I'm inclined to think perhaps there
403 is some reason, however perverse. Perhaps not though... */
404 result = fcntl (0, F_SETFL, tflags_ours);
405 result = fcntl (0, F_SETFL, tflags_ours);
408 result = result; /* lint */
414 term_info (arg, from_tty)
418 target_terminal_info (arg, from_tty);
423 child_terminal_info (args, from_tty)
427 if (!gdb_has_a_terminal ())
429 printf_filtered ("This GDB does not control a terminal.\n");
433 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
435 /* First the fcntl flags. */
439 flags = tflags_inferior;
441 printf_filtered ("File descriptor flags = ");
444 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
446 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
447 switch (flags & (O_ACCMODE))
450 printf_filtered ("O_RDONLY");
453 printf_filtered ("O_WRONLY");
456 printf_filtered ("O_RDWR");
459 flags &= ~(O_ACCMODE);
462 if (flags & O_NONBLOCK)
463 printf_filtered (" | O_NONBLOCK");
464 flags &= ~O_NONBLOCK;
467 #if defined (O_NDELAY)
468 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
469 print it as O_NONBLOCK, which is good cause that is what POSIX
470 has, and the flag will already be cleared by the time we get here. */
471 if (flags & O_NDELAY)
472 printf_filtered (" | O_NDELAY");
476 if (flags & O_APPEND)
477 printf_filtered (" | O_APPEND");
480 #if defined (O_BINARY)
481 if (flags & O_BINARY)
482 printf_filtered (" | O_BINARY");
487 printf_filtered (" | 0x%x", flags);
488 printf_filtered ("\n");
491 #ifdef PROCESS_GROUP_TYPE
492 printf_filtered ("Process group = %d\n",
493 (int) inferior_process_group);
496 SERIAL_PRINT_TTY_STATE (stdin_serial, inferior_ttystate, gdb_stdout);
499 /* NEW_TTY_PREFORK is called before forking a new child process,
500 so we can record the state of ttys in the child to be formed.
501 TTYNAME is null if we are to share the terminal with gdb;
502 or points to a string containing the name of the desired tty.
504 NEW_TTY is called in new child processes under Unix, which will
505 become debugger target processes. This actually switches to
506 the terminal specified in the NEW_TTY_PREFORK call. */
509 new_tty_prefork (ttyname)
512 /* Save the name for later, for determining whether we and the child
513 are sharing a tty. */
514 inferior_thisrun_terminal = ttyname;
522 if (inferior_thisrun_terminal == 0)
524 #if !defined(__GO32__) && !defined(_WIN32)
526 /* Disconnect the child process from our controlling terminal. On some
527 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
529 tty = open ("/dev/tty", O_RDWR);
534 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
535 ioctl (tty, TIOCNOTTY, 0);
537 signal (SIGTTOU, osigttou);
541 /* Now open the specified new terminal. */
544 tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
546 tty = open (inferior_thisrun_terminal, O_RDWR);
550 print_sys_errmsg (inferior_thisrun_terminal, errno);
554 /* Avoid use of dup2; doesn't exist on all systems. */
572 #endif /* !go32 && !win32 */
575 /* Kill the inferior process. Make us have no inferior. */
579 kill_command (arg, from_tty)
583 /* FIXME: This should not really be inferior_pid (or target_has_execution).
584 It should be a distinct flag that indicates that a target is active, cuz
585 some targets don't have processes! */
587 if (inferior_pid == 0)
588 error ("The program is not being run.");
589 if (!query ("Kill the program being debugged? "))
590 error ("Not confirmed.");
593 init_thread_list (); /* Destroy thread info */
595 /* Killing off the inferior can leave us with a core file. If so,
596 print the state we are left in. */
597 if (target_has_stack)
599 printf_filtered ("In %s,\n", target_longname);
600 if (selected_frame == NULL)
601 fputs_filtered ("No selected stack frame.\n", gdb_stdout);
603 print_stack_frame (selected_frame, selected_frame_level, 1);
607 /* Call set_sigint_trap when you need to pass a signal on to an attached
608 process when handling SIGINT */
616 kill (PIDGET (inferior_pid), SIGINT);
620 static void (*osig) ();
625 if (attach_flag || inferior_thisrun_terminal)
627 osig = (void (*)()) signal (SIGINT, pass_signal);
634 if (attach_flag || inferior_thisrun_terminal)
636 signal (SIGINT, osig);
640 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
641 static void (*old_sigio) ();
650 signal (SIGIO, handle_sigio);
653 FD_SET (target_activity_fd, &readfds);
654 numfds = select (target_activity_fd + 1, &readfds, NULL, NULL, NULL);
655 if (numfds >= 0 && FD_ISSET (target_activity_fd, &readfds))
658 if ((*target_activity_function) ())
659 kill (inferior_pid, SIGINT);
664 static int old_fcntl_flags;
669 if (target_activity_function)
671 old_sigio = (void (*)()) signal (SIGIO, handle_sigio);
672 fcntl (target_activity_fd, F_SETOWN, getpid ());
673 old_fcntl_flags = fcntl (target_activity_fd, F_GETFL, 0);
674 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags | FASYNC);
681 if (target_activity_function)
683 signal (SIGIO, old_sigio);
684 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags);
687 #else /* No SIGIO. */
691 if (target_activity_function)
698 if (target_activity_function)
701 #endif /* No SIGIO. */
704 /* This is here because this is where we figure out whether we (probably)
705 have job control. Just using job_control only does part of it because
706 setpgid or setpgrp might not exist on a system without job control.
707 It might be considered misplaced (on the other hand, process groups and
708 job control are closely related to ttys).
710 For a more clean implementation, in libiberty, put a setpgid which merely
711 calls setpgrp and a setpgrp which does nothing (any system with job control
712 will have one or the other). */
720 #if defined (NEED_POSIX_SETPGID) || (defined (HAVE_TERMIOS) && defined (HAVE_SETPGID))
721 /* setpgid (0, 0) is supposed to work and mean the same thing as
722 this, but on Ultrix 4.2A it fails with EPERM (and
723 setpgid (getpid (), getpid ()) succeeds). */
724 retval = setpgid (getpid (), getpid ());
726 #if defined (TIOCGPGRP)
727 #if defined(USG) && !defined(SETPGRP_ARGS)
730 retval = setpgrp (getpid (), getpid ());
732 #endif /* TIOCGPGRP. */
733 #endif /* NEED_POSIX_SETPGID */
739 _initialize_inflow ()
741 add_info ("terminal", term_info,
742 "Print inferior's saved terminal status.");
744 add_com ("kill", class_run, kill_command,
745 "Kill execution of program being debugged.");
749 terminal_is_ours = 1;
751 /* OK, figure out whether we have job control. If neither termios nor
752 sgtty (i.e. termio or go32), leave job_control 0. */
754 #if defined (HAVE_TERMIOS)
755 /* Do all systems with termios have the POSIX way of identifying job
756 control? I hope so. */
757 #ifdef _POSIX_JOB_CONTROL
760 #ifdef _SC_JOB_CONTROL
761 job_control = sysconf (_SC_JOB_CONTROL);
763 job_control = 0; /* have to assume the worst */
764 #endif /* _SC_JOB_CONTROL */
765 #endif /* _POSIX_JOB_CONTROL */
766 #endif /* HAVE_TERMIOS */
773 #endif /* TIOCGPGRP */