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. */
32 #if !defined (HAVE_TERMIOS) && !defined (HAVE_TERMIO) && !defined (HAVE_SGTTY) && !defined (__GO32__)
36 #if defined (HAVE_TERMIOS)
42 #define PROCESS_GROUP_TYPE pid_t
47 /* This is only used for the ultra. Does it have pid_t? */
48 #define PROCESS_GROUP_TYPE short
50 #define PROCESS_GROUP_TYPE int
55 kill_command PARAMS ((char *, int));
58 terminal_ours_1 PARAMS ((int));
60 /* Nonzero if we are debugging an attached outside process
61 rather than an inferior. */
66 /* Record terminal status separately for debugger and inferior. */
68 static serial_t stdin_serial;
70 /* TTY state for the inferior. We save it whenever the inferior stops, and
71 restore it when it resumes. */
72 static serial_ttystate inferior_ttystate;
74 /* Our own tty state, which we restore every time we need to deal with the
75 terminal. We only set it once, when GDB first starts. The settings of
76 flags which readline saves and restores and unimportant. */
77 static serial_ttystate our_ttystate;
79 /* fcntl flags for us and the inferior. Saved and restored just like
80 {our,inferior}_ttystate. */
81 static int tflags_inferior;
82 static int tflags_ours;
84 #ifdef PROCESS_GROUP_TYPE
85 /* Process group for us and the inferior. Saved and restored just like
86 {our,inferior}_ttystate. */
87 PROCESS_GROUP_TYPE our_process_group;
88 PROCESS_GROUP_TYPE inferior_process_group;
91 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
92 inferior only. If we have job control, that takes care of it. If not,
93 we save our handlers in these two variables and set SIGINT and SIGQUIT
95 static void (*sigint_ours) ();
96 static void (*sigquit_ours) ();
98 /* The name of the tty (from the `tty' command) that we gave to the inferior
99 when it was last started. */
101 static char *inferior_thisrun_terminal;
103 /* Nonzero if our terminal settings are in effect. Zero if the
104 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
107 static int terminal_is_ours;
109 enum {yes, no, have_not_checked} gdb_has_a_terminal_flag = have_not_checked;
111 /* Does GDB have a terminal (on stdin)? */
113 gdb_has_a_terminal ()
115 switch (gdb_has_a_terminal_flag)
121 case have_not_checked:
122 /* Get all the current tty settings (including whether we have a tty at
123 all!). Can't do this in _initialize_inflow because SERIAL_FDOPEN
124 won't work until the serial_ops_list is initialized. */
127 tflags_ours = fcntl (0, F_GETFL, 0);
130 gdb_has_a_terminal_flag = no;
131 stdin_serial = SERIAL_FDOPEN (0);
132 if (stdin_serial != NULL)
134 our_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
136 if (our_ttystate != NULL)
138 gdb_has_a_terminal_flag = yes;
140 our_process_group = tcgetpgrp (0);
143 ioctl (0, TIOCGPGRP, &our_process_group);
148 return gdb_has_a_terminal_flag == yes;
152 /* Macro for printing errors from ioctl operations */
154 #define OOPSY(what) \
156 fprintf(stderr, "[%s failed in terminal_inferior: %s]\n", \
157 what, strerror (errno))
159 static void terminal_ours_1 PARAMS ((int));
161 /* Initialize the terminal settings we record for the inferior,
162 before we actually run the inferior. */
165 terminal_init_inferior ()
167 if (gdb_has_a_terminal ())
169 /* We could just as well copy our_ttystate (if we felt like adding
170 a new function SERIAL_COPY_TTY_STATE). */
171 if (inferior_ttystate)
172 free (inferior_ttystate);
173 inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
174 #ifdef PROCESS_GROUP_TYPE
175 inferior_process_group = inferior_pid;
178 /* Make sure that next time we call terminal_inferior (which will be
179 before the program runs, as it needs to be), we install the new
181 terminal_is_ours = 1;
185 /* Put the inferior's terminal settings into effect.
186 This is preparation for starting or resuming the inferior. */
191 if (gdb_has_a_terminal () && terminal_is_ours
192 && inferior_thisrun_terminal == 0)
197 /* Is there a reason this is being done twice? It happens both
198 places we use F_SETFL, so I'm inclined to think perhaps there
199 is some reason, however perverse. Perhaps not though... */
200 result = fcntl (0, F_SETFL, tflags_inferior);
201 result = fcntl (0, F_SETFL, tflags_inferior);
202 OOPSY ("fcntl F_SETFL");
205 /* Because we were careful to not change in or out of raw mode in
206 terminal_ours, we will not change in our out of raw mode with
207 this call, so we don't flush any input. */
208 result = SERIAL_SET_TTY_STATE (stdin_serial, inferior_ttystate);
209 OOPSY ("setting tty state");
213 sigint_ours = (void (*) ()) signal (SIGINT, SIG_IGN);
214 sigquit_ours = (void (*) ()) signal (SIGQUIT, SIG_IGN);
217 /* If attach_flag is set, we don't know whether we are sharing a
218 terminal with the inferior or not. (attaching a process
219 without a terminal is one case where we do not; attaching a
220 process which we ran from the same shell as GDB via `&' is
221 one case where we do, I think (but perhaps this is not
222 `sharing' in the sense that we need to save and restore tty
223 state)). I don't know if there is any way to tell whether we
224 are sharing a terminal. So what we do is to go through all
225 the saving and restoring of the tty state, but ignore errors
226 setting the process group, which will happen if we are not
227 sharing a terminal). */
232 result = tcsetpgrp (0, inferior_process_group);
238 result = ioctl (0, TIOCSPGRP, inferior_process_group);
245 terminal_is_ours = 0;
248 /* Put some of our terminal settings into effect,
249 enough to get proper results from our output,
250 but do not change into or out of RAW mode
251 so that no input is discarded.
253 After doing this, either terminal_ours or terminal_inferior
254 should be called to get back to a normal state of affairs. */
257 terminal_ours_for_output ()
262 /* Put our terminal settings into effect.
263 First record the inferior's terminal settings
264 so they can be restored properly later. */
272 /* output_only is not used, and should not be used unless we introduce
273 separate terminal_is_ours and terminal_is_ours_for_output
277 terminal_ours_1 (output_only)
280 /* Checking inferior_thisrun_terminal is necessary so that
281 if GDB is running in the background, it won't block trying
282 to do the ioctl()'s below. Checking gdb_has_a_terminal
283 avoids attempting all the ioctl's when running in batch. */
284 if (inferior_thisrun_terminal != 0 || gdb_has_a_terminal () == 0)
287 if (!terminal_is_ours)
289 /* Ignore this signal since it will happen when we try to set the
294 terminal_is_ours = 1;
298 osigttou = (void (*) ()) signal (SIGTTOU, SIG_IGN);
301 if (inferior_ttystate)
302 free (inferior_ttystate);
303 inferior_ttystate = SERIAL_GET_TTY_STATE (stdin_serial);
305 inferior_process_group = tcgetpgrp (0);
308 ioctl (0, TIOCGPGRP, &inferior_process_group);
311 /* Here we used to set ICANON in our ttystate, but I believe this
312 was an artifact from before when we used readline. Readline sets
313 the tty state when it needs to. */
315 /* Set tty state to our_ttystate. We don't change in our out of raw
316 mode, to avoid flushing input. We need to do the same thing
317 regardless of output_only, because we don't have separate
318 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
319 though, since readline will deal with raw mode when/if it needs to.
321 SERIAL_NOFLUSH_SET_TTY_STATE (stdin_serial, our_ttystate,
327 result = tcsetpgrp (0, our_process_group);
329 /* This fails on Ultrix with EINVAL if you run the testsuite
330 in the background with nohup, and then log out. GDB never
331 used to check for an error here, so perhaps there are other
332 such situations as well. */
334 fprintf (stderr, "[tcsetpgrp failed in terminal_ours: %s]\n",
340 result = ioctl (0, TIOCSPGRP, our_process_group);
346 signal (SIGTTOU, osigttou);
351 signal (SIGINT, sigint_ours);
352 signal (SIGQUIT, sigquit_ours);
356 tflags_inferior = fcntl (0, F_GETFL, 0);
358 /* Is there a reason this is being done twice? It happens both
359 places we use F_SETFL, so I'm inclined to think perhaps there
360 is some reason, however perverse. Perhaps not though... */
361 result = fcntl (0, F_SETFL, tflags_ours);
362 result = fcntl (0, F_SETFL, tflags_ours);
365 result = result; /* lint */
371 term_info (arg, from_tty)
375 target_terminal_info (arg, from_tty);
380 child_terminal_info (args, from_tty)
384 if (!gdb_has_a_terminal ())
386 printf_filtered ("This GDB does not control a terminal.\n");
390 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
392 /* First the fcntl flags. */
396 flags = tflags_inferior;
398 printf_filtered ("File descriptor flags = ");
401 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
403 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
404 switch (flags & (O_ACCMODE))
406 case O_RDONLY: printf_filtered ("O_RDONLY"); break;
407 case O_WRONLY: printf_filtered ("O_WRONLY"); break;
408 case O_RDWR: printf_filtered ("O_RDWR"); break;
410 flags &= ~(O_ACCMODE);
413 if (flags & O_NONBLOCK)
414 printf_filtered (" | O_NONBLOCK");
415 flags &= ~O_NONBLOCK;
418 #if defined (O_NDELAY)
419 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
420 print it as O_NONBLOCK, which is good cause that is what POSIX
421 has, and the flag will already be cleared by the time we get here. */
422 if (flags & O_NDELAY)
423 printf_filtered (" | O_NDELAY");
427 if (flags & O_APPEND)
428 printf_filtered (" | O_APPEND");
431 #if defined (O_BINARY)
432 if (flags & O_BINARY)
433 printf_filtered (" | O_BINARY");
438 printf_filtered (" | 0x%x", flags);
439 printf_filtered ("\n");
442 #ifdef PROCESS_GROUP_TYPE
443 printf_filtered ("Process group = %d\n", inferior_process_group);
446 SERIAL_PRINT_TTY_STATE (stdin_serial, inferior_ttystate);
449 /* NEW_TTY_PREFORK is called before forking a new child process,
450 so we can record the state of ttys in the child to be formed.
451 TTYNAME is null if we are to share the terminal with gdb;
452 or points to a string containing the name of the desired tty.
454 NEW_TTY is called in new child processes under Unix, which will
455 become debugger target processes. This actually switches to
456 the terminal specified in the NEW_TTY_PREFORK call. */
459 new_tty_prefork (ttyname)
462 /* Save the name for later, for determining whether we and the child
463 are sharing a tty. */
464 inferior_thisrun_terminal = ttyname;
472 if (inferior_thisrun_terminal == 0)
474 #if !defined(__GO32__)
476 /* Disconnect the child process from our controlling terminal. On some
477 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
479 tty = open("/dev/tty", O_RDWR);
484 osigttou = (void (*)()) signal(SIGTTOU, SIG_IGN);
485 ioctl(tty, TIOCNOTTY, 0);
487 signal(SIGTTOU, osigttou);
491 /* Now open the specified new terminal. */
494 tty = open(inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
496 tty = open(inferior_thisrun_terminal, O_RDWR);
500 print_sys_errmsg (inferior_thisrun_terminal, errno);
504 /* Avoid use of dup2; doesn't exist on all systems. */
506 { close (0); dup (tty); }
508 { close (1); dup (tty); }
510 { close (2); dup (tty); }
516 /* Kill the inferior process. Make us have no inferior. */
520 kill_command (arg, from_tty)
524 /* Shouldn't this be target_has_execution? FIXME. */
525 if (inferior_pid == 0)
526 error ("The program is not being run.");
527 if (!query ("Kill the program being debugged? "))
528 error ("Not confirmed.");
531 /* Killing off the inferior can leave us with a core file. If so,
532 print the state we are left in. */
533 if (target_has_stack) {
534 printf_filtered ("In %s,\n", current_target->to_longname);
535 if (selected_frame == NULL)
536 fputs_filtered ("No selected stack frame.\n", stdout);
538 print_stack_frame (selected_frame, selected_frame_level, 1);
542 /* The inferior process has died. Long live the inferior! */
545 generic_mourn_inferior ()
549 breakpoint_init_inferior ();
550 registers_changed ();
552 #ifdef CLEAR_DEFERRED_STORES
553 /* Delete any pending stores to the inferior... */
554 CLEAR_DEFERRED_STORES;
558 reinit_frame_cache ();
560 /* It is confusing to the user for ignore counts to stick around
561 from previous runs of the inferior. So clear them. */
562 breakpoint_clear_ignore_counts ();
565 /* Call set_sigint_trap when you need to pass a signal on to an attached
566 process when handling SIGINT */
573 kill (inferior_pid, SIGINT);
576 static void (*osig)();
581 osig = (void (*) ()) signal (SIGINT, pass_signal);
587 signal (SIGINT, osig);
593 /* This is here because this is where we figure out whether we (probably)
594 have job control. Just using job_control only does part of it because
595 setpgid or setpgrp might not exist on a system without job control.
596 It might be considered misplaced (on the other hand, process groups and
597 job control are closely related to ttys).
599 For a more clean implementation, in libiberty, put a setpgid which merely
600 calls setpgrp and a setpgrp which does nothing (any system with job control
601 will have one or the other). */
608 #if defined (NEED_POSIX_SETPGID) || defined (HAVE_TERMIOS)
609 /* Do all systems with termios have setpgid? I hope so. */
610 /* setpgid (0, 0) is supposed to work and mean the same thing as
611 this, but on Ultrix 4.2A it fails with EPERM (and
612 setpgid (getpid (), getpid ()) succeeds). */
613 retval = setpgid (getpid (), getpid ());
615 #if defined (TIOCGPGRP)
616 #if defined(USG) && !defined(SETPGRP_ARGS)
619 retval = setpgrp (getpid (), getpid ());
621 #endif /* TIOCGPGRP. */
622 #endif /* NEED_POSIX_SETPGID */
628 _initialize_inflow ()
630 add_info ("terminal", term_info,
631 "Print inferior's saved terminal status.");
633 add_com ("kill", class_run, kill_command,
634 "Kill execution of program being debugged.");
638 terminal_is_ours = 1;
640 /* OK, figure out whether we have job control. If neither termios nor
641 sgtty (i.e. termio or go32), leave job_control 0. */
643 #if defined (HAVE_TERMIOS)
644 /* Do all systems with termios have the POSIX way of identifying job
645 control? I hope so. */
646 #ifdef _POSIX_JOB_CONTROL
649 job_control = sysconf (_SC_JOB_CONTROL);
658 #endif /* TIOCGPGRP */