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, 2002, 2003, 2004
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
30 #include "gdbthread.h"
32 #include "gdb_string.h"
35 #ifdef HAVE_SYS_SELECT_H
36 #include <sys/select.h>
41 #ifdef HAVE_SYS_IOCTL_H
42 #include <sys/ioctl.h>
45 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
46 static void handle_sigio (int);
49 extern void _initialize_inflow (void);
51 static void pass_signal (int);
53 static void kill_command (char *, int);
55 static void terminal_ours_1 (int);
57 /* Record terminal status separately for debugger and inferior. */
59 static struct serial *stdin_serial;
61 /* TTY state for the inferior. We save it whenever the inferior stops, and
62 restore it when it resumes. */
63 static serial_ttystate inferior_ttystate;
65 /* Our own tty state, which we restore every time we need to deal with the
66 terminal. We only set it once, when GDB first starts. The settings of
67 flags which readline saves and restores and unimportant. */
68 static serial_ttystate our_ttystate;
70 /* fcntl flags for us and the inferior. Saved and restored just like
71 {our,inferior}_ttystate. */
72 static int tflags_inferior;
73 static int tflags_ours;
75 #ifdef PROCESS_GROUP_TYPE
76 /* Process group for us and the inferior. Saved and restored just like
77 {our,inferior}_ttystate. */
78 PROCESS_GROUP_TYPE our_process_group;
79 PROCESS_GROUP_TYPE inferior_process_group;
82 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
83 inferior only. If we have job control, that takes care of it. If not,
84 we save our handlers in these two variables and set SIGINT and SIGQUIT
87 static void (*sigint_ours) ();
88 static void (*sigquit_ours) ();
90 /* The name of the tty (from the `tty' command) that we gave to the inferior
91 when it was last started. */
93 static char *inferior_thisrun_terminal;
95 /* Nonzero if our terminal settings are in effect. Zero if the
96 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
103 yes, no, have_not_checked
105 gdb_has_a_terminal_flag = have_not_checked;
107 /* Does GDB have a terminal (on stdin)? */
109 gdb_has_a_terminal (void)
111 switch (gdb_has_a_terminal_flag)
117 case have_not_checked:
118 /* Get all the current tty settings (including whether we have a
119 tty at all!). Can't do this in _initialize_inflow because
120 serial_fdopen() won't work until the serial_ops_list is
124 tflags_ours = fcntl (0, F_GETFL, 0);
127 gdb_has_a_terminal_flag = no;
128 stdin_serial = serial_fdopen (0);
129 if (stdin_serial != NULL)
131 our_ttystate = serial_get_tty_state (stdin_serial);
133 if (our_ttystate != NULL)
135 gdb_has_a_terminal_flag = yes;
137 our_process_group = tcgetpgrp (0);
140 our_process_group = getpgrp ();
143 ioctl (0, TIOCGPGRP, &our_process_group);
148 return gdb_has_a_terminal_flag == yes;
150 /* "Can't happen". */
155 /* Macro for printing errors from ioctl operations */
157 #define OOPSY(what) \
159 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
160 what, safe_strerror (errno))
162 static void terminal_ours_1 (int);
164 /* Initialize the terminal settings we record for the inferior,
165 before we actually run the inferior. */
168 terminal_init_inferior_with_pgrp (int pgrp)
170 if (gdb_has_a_terminal ())
172 /* We could just as well copy our_ttystate (if we felt like
173 adding a new function serial_copy_tty_state()). */
174 if (inferior_ttystate)
175 xfree (inferior_ttystate);
176 inferior_ttystate = serial_get_tty_state (stdin_serial);
178 #ifdef PROCESS_GROUP_TYPE
179 inferior_process_group = pgrp;
182 /* Make sure that next time we call terminal_inferior (which will be
183 before the program runs, as it needs to be), we install the new
185 terminal_is_ours = 1;
189 /* Save the terminal settings again. This is necessary for the TUI
190 when it switches to TUI or non-TUI mode; curses changes the terminal
191 and gdb must be able to restore it correctly. */
194 terminal_save_ours (void)
196 if (gdb_has_a_terminal ())
198 /* We could just as well copy our_ttystate (if we felt like adding
199 a new function serial_copy_tty_state). */
201 xfree (our_ttystate);
202 our_ttystate = serial_get_tty_state (stdin_serial);
207 terminal_init_inferior (void)
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_ptid to the same routine). */
215 /* We assume INFERIOR_PID is also the child's process group. */
216 terminal_init_inferior_with_pgrp (PIDGET (inferior_ptid));
217 #endif /* PROCESS_GROUP_TYPE */
220 /* Put the inferior's terminal settings into effect.
221 This is preparation for starting or resuming the inferior. */
224 terminal_inferior (void)
226 if (gdb_has_a_terminal () && terminal_is_ours
227 && inferior_ttystate != NULL
228 && inferior_thisrun_terminal == 0)
233 /* Is there a reason this is being done twice? It happens both
234 places we use F_SETFL, so I'm inclined to think perhaps there
235 is some reason, however perverse. Perhaps not though... */
236 result = fcntl (0, F_SETFL, tflags_inferior);
237 result = fcntl (0, F_SETFL, tflags_inferior);
238 OOPSY ("fcntl F_SETFL");
241 /* Because we were careful to not change in or out of raw mode in
242 terminal_ours, we will not change in our out of raw mode with
243 this call, so we don't flush any input. */
244 result = serial_set_tty_state (stdin_serial, inferior_ttystate);
245 OOPSY ("setting tty state");
249 sigint_ours = (void (*)()) signal (SIGINT, SIG_IGN);
251 sigquit_ours = (void (*)()) signal (SIGQUIT, SIG_IGN);
255 /* If attach_flag is set, we don't know whether we are sharing a
256 terminal with the inferior or not. (attaching a process
257 without a terminal is one case where we do not; attaching a
258 process which we ran from the same shell as GDB via `&' is
259 one case where we do, I think (but perhaps this is not
260 `sharing' in the sense that we need to save and restore tty
261 state)). I don't know if there is any way to tell whether we
262 are sharing a terminal. So what we do is to go through all
263 the saving and restoring of the tty state, but ignore errors
264 setting the process group, which will happen if we are not
265 sharing a terminal). */
270 result = tcsetpgrp (0, inferior_process_group);
276 result = ioctl (0, TIOCSPGRP, &inferior_process_group);
283 terminal_is_ours = 0;
286 /* Put some of our terminal settings into effect,
287 enough to get proper results from our output,
288 but do not change into or out of RAW mode
289 so that no input is discarded.
291 After doing this, either terminal_ours or terminal_inferior
292 should be called to get back to a normal state of affairs. */
295 terminal_ours_for_output (void)
300 /* Put our terminal settings into effect.
301 First record the inferior's terminal settings
302 so they can be restored properly later. */
310 /* output_only is not used, and should not be used unless we introduce
311 separate terminal_is_ours and terminal_is_ours_for_output
315 terminal_ours_1 (int 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)
327 /* Ignore this signal since it will happen when we try to set the
329 void (*osigttou) () = NULL;
333 terminal_is_ours = 1;
337 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
340 if (inferior_ttystate)
341 xfree (inferior_ttystate);
342 inferior_ttystate = serial_get_tty_state (stdin_serial);
344 inferior_process_group = tcgetpgrp (0);
347 inferior_process_group = getpgrp ();
350 ioctl (0, TIOCGPGRP, &inferior_process_group);
353 /* Here we used to set ICANON in our ttystate, but I believe this
354 was an artifact from before when we used readline. Readline sets
355 the tty state when it needs to.
356 FIXME-maybe: However, query() expects non-raw mode and doesn't
357 use readline. Maybe query should use readline (on the other hand,
358 this only matters for HAVE_SGTTY, not termio or termios, I think). */
360 /* Set tty state to our_ttystate. We don't change in our out of raw
361 mode, to avoid flushing input. We need to do the same thing
362 regardless of output_only, because we don't have separate
363 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
364 though, since readline will deal with raw mode when/if it needs to.
367 serial_noflush_set_tty_state (stdin_serial, our_ttystate,
373 result = tcsetpgrp (0, our_process_group);
375 /* This fails on Ultrix with EINVAL if you run the testsuite
376 in the background with nohup, and then log out. GDB never
377 used to check for an error here, so perhaps there are other
378 such situations as well. */
380 fprintf_unfiltered (gdb_stderr, "[tcsetpgrp failed in terminal_ours: %s]\n",
381 safe_strerror (errno));
386 result = ioctl (0, TIOCSPGRP, &our_process_group);
392 signal (SIGTTOU, osigttou);
397 signal (SIGINT, sigint_ours);
399 signal (SIGQUIT, sigquit_ours);
404 tflags_inferior = fcntl (0, F_GETFL, 0);
406 /* Is there a reason this is being done twice? It happens both
407 places we use F_SETFL, so I'm inclined to think perhaps there
408 is some reason, however perverse. Perhaps not though... */
409 result = fcntl (0, F_SETFL, tflags_ours);
410 result = fcntl (0, F_SETFL, tflags_ours);
413 result = result; /* lint */
418 term_info (char *arg, int from_tty)
420 target_terminal_info (arg, from_tty);
424 child_terminal_info (char *args, int from_tty)
426 if (!gdb_has_a_terminal ())
428 printf_filtered ("This GDB does not control a terminal.\n");
432 printf_filtered ("Inferior's terminal status (currently saved by GDB):\n");
434 /* First the fcntl flags. */
438 flags = tflags_inferior;
440 printf_filtered ("File descriptor flags = ");
443 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
445 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
446 switch (flags & (O_ACCMODE))
449 printf_filtered ("O_RDONLY");
452 printf_filtered ("O_WRONLY");
455 printf_filtered ("O_RDWR");
458 flags &= ~(O_ACCMODE);
461 if (flags & O_NONBLOCK)
462 printf_filtered (" | O_NONBLOCK");
463 flags &= ~O_NONBLOCK;
466 #if defined (O_NDELAY)
467 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
468 print it as O_NONBLOCK, which is good cause that is what POSIX
469 has, and the flag will already be cleared by the time we get here. */
470 if (flags & O_NDELAY)
471 printf_filtered (" | O_NDELAY");
475 if (flags & O_APPEND)
476 printf_filtered (" | O_APPEND");
479 #if defined (O_BINARY)
480 if (flags & O_BINARY)
481 printf_filtered (" | O_BINARY");
486 printf_filtered (" | 0x%x", flags);
487 printf_filtered ("\n");
490 #ifdef PROCESS_GROUP_TYPE
491 printf_filtered ("Process group = %d\n",
492 (int) inferior_process_group);
495 serial_print_tty_state (stdin_serial, inferior_ttystate, gdb_stdout);
498 /* NEW_TTY_PREFORK is called before forking a new child process,
499 so we can record the state of ttys in the child to be formed.
500 TTYNAME is null if we are to share the terminal with gdb;
501 or points to a string containing the name of the desired tty.
503 NEW_TTY is called in new child processes under Unix, which will
504 become debugger target processes. This actually switches to
505 the terminal specified in the NEW_TTY_PREFORK call. */
508 new_tty_prefork (char *ttyname)
510 /* Save the name for later, for determining whether we and the child
511 are sharing a tty. */
512 inferior_thisrun_terminal = ttyname;
520 if (inferior_thisrun_terminal == 0)
522 #if !defined(__GO32__) && !defined(_WIN32)
524 /* Disconnect the child process from our controlling terminal. On some
525 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
527 tty = open ("/dev/tty", O_RDWR);
532 osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
533 ioctl (tty, TIOCNOTTY, 0);
535 signal (SIGTTOU, osigttou);
539 /* Now open the specified new terminal. */
542 tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
544 tty = open (inferior_thisrun_terminal, O_RDWR);
548 print_sys_errmsg (inferior_thisrun_terminal, errno);
552 /* Avoid use of dup2; doesn't exist on all systems. */
570 #endif /* !go32 && !win32 */
573 /* Kill the inferior process. Make us have no inferior. */
576 kill_command (char *arg, int from_tty)
578 /* FIXME: This should not really be inferior_ptid (or target_has_execution).
579 It should be a distinct flag that indicates that a target is active, cuz
580 some targets don't have processes! */
582 if (ptid_equal (inferior_ptid, null_ptid))
583 error ("The program is not being run.");
584 if (!query ("Kill the program being debugged? "))
585 error ("Not confirmed.");
588 init_thread_list (); /* Destroy thread info */
590 /* Killing off the inferior can leave us with a core file. If so,
591 print the state we are left in. */
592 if (target_has_stack)
594 printf_filtered ("In %s,\n", target_longname);
595 if (deprecated_selected_frame == NULL)
596 fputs_filtered ("No selected stack frame.\n", gdb_stdout);
598 print_stack_frame (get_selected_frame (), 1, SRC_AND_LOC);
602 /* Call set_sigint_trap when you need to pass a signal on to an attached
603 process when handling SIGINT */
606 pass_signal (int signo)
609 kill (PIDGET (inferior_ptid), SIGINT);
613 static void (*osig) ();
616 set_sigint_trap (void)
618 if (attach_flag || inferior_thisrun_terminal)
620 osig = (void (*)()) signal (SIGINT, pass_signal);
625 clear_sigint_trap (void)
627 if (attach_flag || inferior_thisrun_terminal)
629 signal (SIGINT, osig);
633 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
634 static void (*old_sigio) ();
637 handle_sigio (int signo)
642 signal (SIGIO, handle_sigio);
645 FD_SET (target_activity_fd, &readfds);
646 numfds = select (target_activity_fd + 1, &readfds, NULL, NULL, NULL);
647 if (numfds >= 0 && FD_ISSET (target_activity_fd, &readfds))
650 if ((*target_activity_function) ())
651 kill (PIDGET (inferior_ptid), SIGINT);
656 static int old_fcntl_flags;
659 set_sigio_trap (void)
661 if (target_activity_function)
663 old_sigio = (void (*)()) signal (SIGIO, handle_sigio);
664 fcntl (target_activity_fd, F_SETOWN, getpid ());
665 old_fcntl_flags = fcntl (target_activity_fd, F_GETFL, 0);
666 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags | FASYNC);
671 clear_sigio_trap (void)
673 if (target_activity_function)
675 signal (SIGIO, old_sigio);
676 fcntl (target_activity_fd, F_SETFL, old_fcntl_flags);
679 #else /* No SIGIO. */
681 set_sigio_trap (void)
683 if (target_activity_function)
684 internal_error (__FILE__, __LINE__, "failed internal consistency check");
688 clear_sigio_trap (void)
690 if (target_activity_function)
691 internal_error (__FILE__, __LINE__, "failed internal consistency check");
693 #endif /* No SIGIO. */
696 /* This is here because this is where we figure out whether we (probably)
697 have job control. Just using job_control only does part of it because
698 setpgid or setpgrp might not exist on a system without job control.
699 It might be considered misplaced (on the other hand, process groups and
700 job control are closely related to ttys).
702 For a more clean implementation, in libiberty, put a setpgid which merely
703 calls setpgrp and a setpgrp which does nothing (any system with job control
704 will have one or the other). */
712 #if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
714 /* The call setpgid (0, 0) is supposed to work and mean the same
715 thing as this, but on Ultrix 4.2A it fails with EPERM (and
716 setpgid (getpid (), getpid ()) succeeds). */
717 retval = setpgid (getpid (), getpid ());
723 retval = setpgrp (getpid (), getpid ());
725 #endif /* HAVE_SETPGRP */
726 #endif /* HAVE_SETPGID */
727 #endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
734 _initialize_inflow (void)
736 add_info ("terminal", term_info,
737 "Print inferior's saved terminal status.");
739 add_com ("kill", class_run, kill_command,
740 "Kill execution of program being debugged.");
742 inferior_ptid = null_ptid;
744 terminal_is_ours = 1;
746 /* OK, figure out whether we have job control. If neither termios nor
747 sgtty (i.e. termio or go32), leave job_control 0. */
749 #if defined (HAVE_TERMIOS)
750 /* Do all systems with termios have the POSIX way of identifying job
751 control? I hope so. */
752 #ifdef _POSIX_JOB_CONTROL
755 #ifdef _SC_JOB_CONTROL
756 job_control = sysconf (_SC_JOB_CONTROL);
758 job_control = 0; /* have to assume the worst */
759 #endif /* _SC_JOB_CONTROL */
760 #endif /* _POSIX_JOB_CONTROL */
761 #endif /* HAVE_TERMIOS */
768 #endif /* TIOCGPGRP */