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 /* Record terminal status separately for debugger and inferior. */
63 static serial_t stdin_serial;
65 /* TTY state for the inferior. We save it whenever the inferior stops, and
66 restore it when it resumes. */
67 static serial_ttystate inferior_ttystate;
69 /* Our own tty state, which we restore every time we need to deal with the
70 terminal. We only set it once, when GDB first starts. The settings of
71 flags which readline saves and restores and unimportant. */
72 static serial_ttystate our_ttystate;
74 /* fcntl flags for us and the inferior. Saved and restored just like
75 {our,inferior}_ttystate. */
76 static int tflags_inferior;
77 static int tflags_ours;
79 #ifdef PROCESS_GROUP_TYPE
80 /* Process group for us and the inferior. Saved and restored just like
81 {our,inferior}_ttystate. */
82 PROCESS_GROUP_TYPE our_process_group;
83 PROCESS_GROUP_TYPE inferior_process_group;
86 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
87 inferior only. If we have job control, that takes care of it. If not,
88 we save our handlers in these two variables and set SIGINT and SIGQUIT
90 static void (*sigint_ours) ();
91 static void (*sigquit_ours) ();
93 /* The name of the tty (from the `tty' command) that we gave to the inferior
94 when it was last started. */
96 static char *inferior_thisrun_terminal;
98 /* Nonzero if our terminal settings are in effect. Zero if the
99 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
102 static int terminal_is_ours;
104 enum {yes, no, have_not_checked} gdb_has_a_terminal_flag = have_not_checked;
106 /* Does GDB have a terminal (on stdin)? */
108 gdb_has_a_terminal ()
110 switch (gdb_has_a_terminal_flag)
116 case have_not_checked:
117 /* Get all the current tty settings (including whether we have a tty at
118 all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
119 won't work until the serial_ops_list is initialized. */
122 tflags_ours = fcntl (0, F_GETFL, 0);
125 gdb_has_a_terminal_flag = no;
126 stdin_serial = SERIAL_FDOPEN (0);
127 if (stdin_serial != NULL)
129 our_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
131 if (our_ttystate != NULL)
133 gdb_has_a_terminal_flag = yes;
135 our_process_group = tcgetpgrp (0);
138 ioctl (0, TIOCGPGRP, &our_process_group);
143 return gdb_has_a_terminal_flag == yes;
145 /* "Can't happen". */
150 /* Macro for printing errors from ioctl operations */
152 #define OOPSY(what) \
154 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
155 what, strerror (errno))
157 static void terminal_ours_1 PARAMS ((int));
159 /* Initialize the terminal settings we record for the inferior,
160 before we actually run the inferior. */
163 terminal_init_inferior ()
165 if (gdb_has_a_terminal ())
167 /* We could just as well copy our_ttystate (if we felt like adding
168 a new function SERIAL_COPY_TTY_STATE). */
169 if (inferior_ttystate)
170 free (inferior_ttystate);
171 inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
172 #ifdef PROCESS_GROUP_TYPE
174 /* This is for Lynx, and should be cleaned up by having Lynx be
175 a separate debugging target with a version of
176 target_terminal_init_inferior which passes in the process
177 group to a generic routine which does all the work (and the
178 non-threaded child_terminal_init_inferior can just pass in
179 inferior_pid to the same routine). */
180 inferior_process_group = PIDGET (inferior_pid);
182 inferior_process_group = inferior_pid;
186 /* Make sure that next time we call terminal_inferior (which will be
187 before the program runs, as it needs to be), we install the new
189 terminal_is_ours = 1;
193 /* Put the inferior's terminal settings into effect.
194 This is preparation for starting or resuming the inferior. */
199 if (gdb_has_a_terminal () && terminal_is_ours
200 && inferior_thisrun_terminal == 0)
205 /* Is there a reason this is being done twice? It happens both
206 places we use F_SETFL, so I'm inclined to think perhaps there
207 is some reason, however perverse. Perhaps not though... */
208 result = fcntl (0, F_SETFL, tflags_inferior);
209 result = fcntl (0, F_SETFL, tflags_inferior);
210 OOPSY ("fcntl F_SETFL");
213 /* Because we were careful to not change in or out of raw mode in
214 terminal_ours, we will not change in our out of raw mode with
215 this call, so we don't flush any input. */
216 result = SERIAL_SET_TTY_STATE (stdin_serial, inferior_ttystate);
217 OOPSY ("setting tty state");
221 sigint_ours = (void (*) ()) signal (SIGINT, SIG_IGN);
222 sigquit_ours = (void (*) ()) signal (SIGQUIT, SIG_IGN);
225 /* If attach_flag is set, we don't know whether we are sharing a
226 terminal with the inferior or not. (attaching a process
227 without a terminal is one case where we do not; attaching a
228 process which we ran from the same shell as GDB via `&' is
229 one case where we do, I think (but perhaps this is not
230 `sharing' in the sense that we need to save and restore tty
231 state)). I don't know if there is any way to tell whether we
232 are sharing a terminal. So what we do is to go through all
233 the saving and restoring of the tty state, but ignore errors
234 setting the process group, which will happen if we are not
235 sharing a terminal). */
240 result = tcsetpgrp (0, inferior_process_group);
246 result = ioctl (0, TIOCSPGRP, &inferior_process_group);
253 terminal_is_ours = 0;
256 /* Put some of our terminal settings into effect,
257 enough to get proper results from our output,
258 but do not change into or out of RAW mode
259 so that no input is discarded.
261 After doing this, either terminal_ours or terminal_inferior
262 should be called to get back to a normal state of affairs. */
265 terminal_ours_for_output ()
270 /* Put our terminal settings into effect.
271 First record the inferior's terminal settings
272 so they can be restored properly later. */
280 /* output_only is not used, and should not be used unless we introduce
281 separate terminal_is_ours and terminal_is_ours_for_output
285 terminal_ours_1 (output_only)
288 /* Checking inferior_thisrun_terminal is necessary so that
289 if GDB is running in the background, it won't block trying
290 to do the ioctl()'s below. Checking gdb_has_a_terminal
291 avoids attempting all the ioctl's when running in batch. */
292 if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)
295 if (!terminal_is_ours)
297 /* Ignore this signal since it will happen when we try to set the
302 terminal_is_ours = 1;
306 osigttou = (void (*) ()) signal (SIGTTOU, SIG_IGN);
309 if (inferior_ttystate)
310 free (inferior_ttystate);
311 inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
313 inferior_process_group = tcgetpgrp (0);
316 ioctl (0, TIOCGPGRP, &inferior_process_group);
319 /* Here we used to set ICANON in our ttystate, but I believe this
320 was an artifact from before when we used readline. Readline sets
321 the tty state when it needs to.
322 FIXME-maybe: However, query() expects non-raw mode and doesn't
323 use readline. Maybe query should use readline (on the other hand,
324 this only matters for HAVE_SGTTY, not termio or termios, I think). */
326 /* Set tty state to our_ttystate. We don't change in our out of raw
327 mode, to avoid flushing input. We need to do the same thing
328 regardless of output_only, because we don't have separate
329 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
330 though, since readline will deal with raw mode when/if it needs to.
333 SERIAL_NOFLUSH_SET_TTY_STATE (stdin_serial, our_ttystate,
339 result = tcsetpgrp (0, our_process_group);
341 /* This fails on Ultrix with EINVAL if you run the testsuite
342 in the background with nohup, and then log out. GDB never
343 used to check for an error here, so perhaps there are other
344 such situations as well. */
346 fprintf_unfiltered (gdb_stderr, "[tcsetpgrp failed in terminal_ours: %s]\n",
352 result = ioctl (0, TIOCSPGRP, &our_process_group);
358 signal (SIGTTOU, osigttou);
363 signal (SIGINT, sigint_ours);
364 signal (SIGQUIT, sigquit_ours);
368 tflags_inferior = fcntl (0, F_GETFL, 0);
370 /* Is there a reason this is being done twice? It happens both
371 places we use F_SETFL, so I'm inclined to think perhaps there
372 is some reason, however perverse. Perhaps not though... */
373 result = fcntl (0, F_SETFL, tflags_ours);
374 result = fcntl (0, F_SETFL, tflags_ours);
377 result = result; /* lint */
383 term_info (arg, from_tty)
387 target_terminal_info (arg, from_tty);
392 child_terminal_info (args, from_tty)
396 if (!gdb_has_a_terminal ())
398 printf_filtered ("This GDB does not control a terminal.\n");
402 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
404 /* First the fcntl flags. */
408 flags = tflags_inferior;
410 printf_filtered ("File descriptor flags = ");
413 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
415 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
416 switch (flags & (O_ACCMODE))
418 case O_RDONLY: printf_filtered ("O_RDONLY"); break;
419 case O_WRONLY: printf_filtered ("O_WRONLY"); break;
420 case O_RDWR: printf_filtered ("O_RDWR"); break;
422 flags &= ~(O_ACCMODE);
425 if (flags & O_NONBLOCK)
426 printf_filtered (" | O_NONBLOCK");
427 flags &= ~O_NONBLOCK;
430 #if defined (O_NDELAY)
431 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
432 print it as O_NONBLOCK, which is good cause that is what POSIX
433 has, and the flag will already be cleared by the time we get here. */
434 if (flags & O_NDELAY)
435 printf_filtered (" | O_NDELAY");
439 if (flags & O_APPEND)
440 printf_filtered (" | O_APPEND");
443 #if defined (O_BINARY)
444 if (flags & O_BINARY)
445 printf_filtered (" | O_BINARY");
450 printf_filtered (" | 0x%x", flags);
451 printf_filtered ("\n");
454 #ifdef PROCESS_GROUP_TYPE
455 printf_filtered ("Process group = %d\n", inferior_process_group);
458 SERIAL_PRINT_TTY_STATE (stdin_serial, inferior_ttystate);
461 /* NEW_TTY_PREFORK is called before forking a new child process,
462 so we can record the state of ttys in the child to be formed.
463 TTYNAME is null if we are to share the terminal with gdb;
464 or points to a string containing the name of the desired tty.
466 NEW_TTY is called in new child processes under Unix, which will
467 become debugger target processes. This actually switches to
468 the terminal specified in the NEW_TTY_PREFORK call. */
471 new_tty_prefork (ttyname)
474 /* Save the name for later, for determining whether we and the child
475 are sharing a tty. */
476 inferior_thisrun_terminal = ttyname;
484 if (inferior_thisrun_terminal == 0)
486 #if !defined(__GO32__)
488 /* Disconnect the child process from our controlling terminal. On some
489 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
491 tty = open("/dev/tty", O_RDWR);
496 osigttou = (void (*)()) signal(SIGTTOU, SIG_IGN);
497 ioctl(tty, TIOCNOTTY, 0);
499 signal(SIGTTOU, osigttou);
503 /* Now open the specified new terminal. */
506 tty = open(inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
508 tty = open(inferior_thisrun_terminal, O_RDWR);
512 print_sys_errmsg (inferior_thisrun_terminal, errno);
516 /* Avoid use of dup2; doesn't exist on all systems. */
518 { close (0); dup (tty); }
520 { close (1); dup (tty); }
522 { close (2); dup (tty); }
528 /* Kill the inferior process. Make us have no inferior. */
532 kill_command (arg, from_tty)
536 if (!target_has_execution)
537 error ("The program is not being run.");
538 if (!query ("Kill the program being debugged? "))
539 error ("Not confirmed.");
542 init_thread_list(); /* Destroy thread info */
544 /* Killing off the inferior can leave us with a core file. If so,
545 print the state we are left in. */
546 if (target_has_stack) {
547 printf_filtered ("In %s,\n", target_longname);
548 if (selected_frame == NULL)
549 fputs_filtered ("No selected stack frame.\n", gdb_stdout);
551 print_stack_frame (selected_frame, selected_frame_level, 1);
555 /* Call set_sigint_trap when you need to pass a signal on to an attached
556 process when handling SIGINT */
563 kill (inferior_pid, SIGINT);
566 static void (*osig)();
571 osig = (void (*) ()) signal (SIGINT, pass_signal);
577 signal (SIGINT, osig);
580 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
581 static void (*old_sigio) ();
590 signal (SIGIO, handle_sigio);
593 FD_SET (target_activity_fd, &readfds);
594 numfds = select (target_activity_fd + 1, &readfds, NULL, NULL, NULL);
595 if (numfds >= 0 && FD_ISSET (target_activity_fd, &readfds))
597 if ((*target_activity_function) ())
598 kill (inferior_pid, SIGINT);
602 static int old_fcntl_flags;
607 if (target_activity_function)
609 old_sigio = (void (*) ()) signal (SIGIO, handle_sigio);
610 fcntl (target_activity_fd, F_SETOWN, getpid());
611 old_fcntl_flags = fcntl (target_activity_fd, F_GETFL, 0);
612 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags | FASYNC);
619 if (target_activity_function)
621 signal (SIGIO, old_sigio);
622 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags);
625 #else /* No SIGIO. */
629 if (target_activity_function)
636 if (target_activity_function)
639 #endif /* No SIGIO. */
642 /* This is here because this is where we figure out whether we (probably)
643 have job control. Just using job_control only does part of it because
644 setpgid or setpgrp might not exist on a system without job control.
645 It might be considered misplaced (on the other hand, process groups and
646 job control are closely related to ttys).
648 For a more clean implementation, in libiberty, put a setpgid which merely
649 calls setpgrp and a setpgrp which does nothing (any system with job control
650 will have one or the other). */
658 #if defined (NEED_POSIX_SETPGID) || defined (HAVE_TERMIOS)
659 /* Do all systems with termios have setpgid? I hope so. */
660 /* setpgid (0, 0) is supposed to work and mean the same thing as
661 this, but on Ultrix 4.2A it fails with EPERM (and
662 setpgid (getpid (), getpid ()) succeeds). */
663 retval = setpgid (getpid (), getpid ());
665 #if defined (TIOCGPGRP)
666 #if defined(USG) && !defined(SETPGRP_ARGS)
669 retval = setpgrp (getpid (), getpid ());
671 #endif /* TIOCGPGRP. */
672 #endif /* NEED_POSIX_SETPGID */
678 _initialize_inflow ()
680 add_info ("terminal", term_info,
681 "Print inferior's saved terminal status.");
683 add_com ("kill", class_run, kill_command,
684 "Kill execution of program being debugged.");
688 terminal_is_ours = 1;
690 /* OK, figure out whether we have job control. If neither termios nor
691 sgtty (i.e. termio or go32), leave job_control 0. */
693 #if defined (HAVE_TERMIOS)
694 /* Do all systems with termios have the POSIX way of identifying job
695 control? I hope so. */
696 #ifdef _POSIX_JOB_CONTROL
699 job_control = sysconf (_SC_JOB_CONTROL);
708 #endif /* TIOCGPGRP */