GDB (xrefs)
/tmp/gdb-7.10/gdb/inflow.c
Go to the documentation of this file.
1 /* Low level interface to ptrace, for GDB when running under Unix.
2  Copyright (C) 1986-2015 Free Software Foundation, Inc.
3 
4  This file is part of GDB.
5 
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 3 of the License, or
9  (at your option) any later version.
10 
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.
15 
16  You should have received a copy of the GNU General Public License
17  along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 
19 #include "defs.h"
20 #include "frame.h"
21 #include "inferior.h"
22 #include "command.h"
23 #include "serial.h"
24 #include "terminal.h"
25 #include "target.h"
26 #include "gdbthread.h"
27 #include "observer.h"
28 #include <signal.h>
29 #include <fcntl.h>
30 #include "gdb_select.h"
31 
32 #include "inflow.h"
33 #include "gdbcmd.h"
34 
35 #ifdef HAVE_SYS_IOCTL_H
36 #include <sys/ioctl.h>
37 #endif
38 
39 #ifndef O_NOCTTY
40 #define O_NOCTTY 0
41 #endif
42 
43 extern void _initialize_inflow (void);
44 
45 static void pass_signal (int);
46 
47 static void child_terminal_ours_1 (int);
48 
49 /* Record terminal status separately for debugger and inferior. */
50 
51 static struct serial *stdin_serial;
52 
53 /* Terminal related info we need to keep track of. Each inferior
54  holds an instance of this structure --- we save it whenever the
55  corresponding inferior stops, and restore it to the foreground
56  inferior when it resumes. */
58 {
59  /* The name of the tty (from the `tty' command) that we gave to the
60  inferior when it was started. */
61  char *run_terminal;
62 
63  /* TTY state. We save it whenever the inferior stops, and restore
64  it when it resumes. */
66 
67 #ifdef PROCESS_GROUP_TYPE
68  /* Process group. Saved and restored just like ttystate. */
70 #endif
71 
72  /* fcntl flags. Saved and restored just like ttystate. */
73  int tflags;
74 };
75 
76 /* Our own tty state, which we restore every time we need to deal with
77  the terminal. This is only set once, when GDB first starts. The
78  settings of flags which readline saves and restores and
79  unimportant. */
81 
82 /* Snapshot of our own tty state taken during initialization of GDB.
83  This is used as the initial tty state given to each new inferior. */
85 
86 static struct terminal_info *get_inflow_inferior_data (struct inferior *);
87 
88 #ifdef PROCESS_GROUP_TYPE
89 
90 /* Return the process group of the current inferior. */
91 
94 {
96 }
97 #endif
98 
99 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
100  inferior only. If we have job control, that takes care of it. If not,
101  we save our handlers in these two variables and set SIGINT and SIGQUIT
102  to SIG_IGN. */
103 
104 static void (*sigint_ours) ();
105 static void (*sigquit_ours) ();
106 
107 /* The name of the tty (from the `tty' command) that we're giving to
108  the inferior when starting it up. This is only (and should only
109  be) used as a transient global by new_tty_prefork,
110  create_tty_session, new_tty and new_tty_postfork, all called from
111  fork_inferior, while forking a new child. */
112 static const char *inferior_thisrun_terminal;
113 
114 /* Nonzero if our terminal settings are in effect. Zero if the
115  inferior's settings are in effect. Ignored if !gdb_has_a_terminal
116  (). */
117 
119 
120 #ifdef PROCESS_GROUP_TYPE
121 static PROCESS_GROUP_TYPE
123 {
124  int process_group = -1;
125 
126 #ifdef HAVE_TERMIOS
127  process_group = tcgetpgrp (0);
128 #endif
129 #ifdef HAVE_TERMIO
130  process_group = getpgrp ();
131 #endif
132 #ifdef HAVE_SGTTY
133  ioctl (0, TIOCGPGRP, &process_group);
134 #endif
135  return process_group;
136 }
137 #endif
138 
139 enum
140  {
142  }
144 
145 /* The value of the "interactive-mode" setting. */
147 
148 /* Implement the "show interactive-mode" option. */
149 
150 static void
151 show_interactive_mode (struct ui_file *file, int from_tty,
152  struct cmd_list_element *c,
153  const char *value)
154 {
156  fprintf_filtered (file, "Debugger's interactive mode "
157  "is %s (currently %s).\n",
158  value, gdb_has_a_terminal () ? "on" : "off");
159  else
160  fprintf_filtered (file, "Debugger's interactive mode is %s.\n", value);
161 }
162 
163 /* Set the initial tty state that is to be inherited by new inferiors. */
164 
165 void
167 {
169 }
170 
171 /* Does GDB have a terminal (on stdin)? */
172 int
174 {
177 
178  switch (gdb_has_a_terminal_flag)
179  {
180  case yes:
181  return 1;
182  case no:
183  return 0;
184  case have_not_checked:
185  /* Get all the current tty settings (including whether we have a
186  tty at all!). Can't do this in _initialize_inflow because
187  serial_fdopen() won't work until the serial_ops_list is
188  initialized. */
189 
190 #ifdef F_GETFL
191  our_terminal_info.tflags = fcntl (0, F_GETFL, 0);
192 #endif
193 
195  if (stdin_serial != NULL)
196  {
198 
199  if (our_terminal_info.ttystate != NULL)
200  {
202 #ifdef PROCESS_GROUP_TYPE
204 #endif
205  }
206  }
207 
208  return gdb_has_a_terminal_flag == yes;
209  default:
210  /* "Can't happen". */
211  return 0;
212  }
213 }
214 
215 /* Macro for printing errors from ioctl operations */
216 
217 #define OOPSY(what) \
218  if (result == -1) \
219  fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
220  what, safe_strerror (errno))
221 
222 /* Initialize the terminal settings we record for the inferior,
223  before we actually run the inferior. */
224 
225 void
227 {
228  struct inferior *inf = current_inferior ();
229  struct terminal_info *tinfo = get_inflow_inferior_data (inf);
230 
231 #ifdef PROCESS_GROUP_TYPE
232  /* Store the process group even without a terminal as it is used not
233  only to reset the tty foreground process group, but also to
234  interrupt the inferior. */
235  tinfo->process_group = pgrp;
236 #endif
237 
238  if (gdb_has_a_terminal ())
239  {
240  xfree (tinfo->ttystate);
241  tinfo->ttystate = serial_copy_tty_state (stdin_serial,
243 
244  /* Make sure that next time we call terminal_inferior (which will be
245  before the program runs, as it needs to be), we install the new
246  process group. */
247  terminal_is_ours = 1;
248  }
249 }
250 
251 /* Save the terminal settings again. This is necessary for the TUI
252  when it switches to TUI or non-TUI mode; curses changes the terminal
253  and gdb must be able to restore it correctly. */
254 
255 void
257 {
258  if (gdb_has_a_terminal ())
259  {
262  }
263 }
264 
265 void
267 {
268 #ifdef PROCESS_GROUP_TYPE
269  /* This is for Lynx, and should be cleaned up by having Lynx be a
270  separate debugging target with a version of target_terminal_init
271  which passes in the process group to a generic routine which does
272  all the work (and the non-threaded child_terminal_init can just
273  pass in inferior_ptid to the same routine). */
274  /* We assume INFERIOR_PID is also the child's process group. */
276 #endif /* PROCESS_GROUP_TYPE */
277 }
278 
279 /* Put the inferior's terminal settings into effect.
280  This is preparation for starting or resuming the inferior.
281 
282  N.B. Targets that want to use this with async support must build that
283  support on top of this (e.g., the caller still needs to remove stdin
284  from the event loop). E.g., see linux_nat_terminal_inferior. */
285 
286 void
288 {
289  struct inferior *inf;
290  struct terminal_info *tinfo;
291 
292  if (!terminal_is_ours)
293  return;
294 
295  inf = current_inferior ();
296  tinfo = get_inflow_inferior_data (inf);
297 
298  if (gdb_has_a_terminal ()
299  && tinfo->ttystate != NULL
300  && tinfo->run_terminal == NULL)
301  {
302  int result;
303 
304 #ifdef F_GETFL
305  /* Is there a reason this is being done twice? It happens both
306  places we use F_SETFL, so I'm inclined to think perhaps there
307  is some reason, however perverse. Perhaps not though... */
308  result = fcntl (0, F_SETFL, tinfo->tflags);
309  result = fcntl (0, F_SETFL, tinfo->tflags);
310  OOPSY ("fcntl F_SETFL");
311 #endif
312 
313  /* Because we were careful to not change in or out of raw mode in
314  terminal_ours, we will not change in our out of raw mode with
315  this call, so we don't flush any input. */
316  result = serial_set_tty_state (stdin_serial,
317  tinfo->ttystate);
318  OOPSY ("setting tty state");
319 
320  if (!job_control)
321  {
322  sigint_ours = (void (*)()) signal (SIGINT, SIG_IGN);
323 #ifdef SIGQUIT
324  sigquit_ours = (void (*)()) signal (SIGQUIT, SIG_IGN);
325 #endif
326  }
327 
328  /* If attach_flag is set, we don't know whether we are sharing a
329  terminal with the inferior or not. (attaching a process
330  without a terminal is one case where we do not; attaching a
331  process which we ran from the same shell as GDB via `&' is
332  one case where we do, I think (but perhaps this is not
333  `sharing' in the sense that we need to save and restore tty
334  state)). I don't know if there is any way to tell whether we
335  are sharing a terminal. So what we do is to go through all
336  the saving and restoring of the tty state, but ignore errors
337  setting the process group, which will happen if we are not
338  sharing a terminal). */
339 
340  if (job_control)
341  {
342 #ifdef HAVE_TERMIOS
343  result = tcsetpgrp (0, tinfo->process_group);
344  if (!inf->attach_flag)
345  OOPSY ("tcsetpgrp");
346 #endif
347 
348 #ifdef HAVE_SGTTY
349  result = ioctl (0, TIOCSPGRP, &tinfo->process_group);
350  if (!inf->attach_flag)
351  OOPSY ("TIOCSPGRP");
352 #endif
353  }
354 
355  }
356  terminal_is_ours = 0;
357 }
358 
359 /* Put some of our terminal settings into effect,
360  enough to get proper results from our output,
361  but do not change into or out of RAW mode
362  so that no input is discarded.
363 
364  After doing this, either terminal_ours or terminal_inferior
365  should be called to get back to a normal state of affairs.
366 
367  N.B. The implementation is (currently) no different than
368  child_terminal_ours. See child_terminal_ours_1. */
369 
370 void
372 {
374 }
375 
376 /* Put our terminal settings into effect.
377  First record the inferior's terminal settings
378  so they can be restored properly later.
379 
380  N.B. Targets that want to use this with async support must build that
381  support on top of this (e.g., the caller still needs to add stdin to the
382  event loop). E.g., see linux_nat_terminal_ours. */
383 
384 void
386 {
388 }
389 
390 /* output_only is not used, and should not be used unless we introduce
391  separate terminal_is_ours and terminal_is_ours_for_output
392  flags. */
393 
394 static void
395 child_terminal_ours_1 (int output_only)
396 {
397  struct inferior *inf;
398  struct terminal_info *tinfo;
399 
400  if (terminal_is_ours)
401  return;
402 
403  terminal_is_ours = 1;
404 
405  /* Checking inferior->run_terminal is necessary so that
406  if GDB is running in the background, it won't block trying
407  to do the ioctl()'s below. Checking gdb_has_a_terminal
408  avoids attempting all the ioctl's when running in batch. */
409 
410  inf = current_inferior ();
411  tinfo = get_inflow_inferior_data (inf);
412 
413  if (tinfo->run_terminal != NULL || gdb_has_a_terminal () == 0)
414  return;
415 
416  {
417 #ifdef SIGTTOU
418  /* Ignore this signal since it will happen when we try to set the
419  pgrp. */
420  void (*osigttou) () = NULL;
421 #endif
422  int result;
423 
424 #ifdef SIGTTOU
425  if (job_control)
426  osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
427 #endif
428 
429  xfree (tinfo->ttystate);
430  tinfo->ttystate = serial_get_tty_state (stdin_serial);
431 
432 #ifdef PROCESS_GROUP_TYPE
433  if (!inf->attach_flag)
434  /* If setpgrp failed in terminal_inferior, this would give us
435  our process group instead of the inferior's. See
436  terminal_inferior for details. */
437  tinfo->process_group = gdb_getpgrp ();
438 #endif
439 
440  /* Here we used to set ICANON in our ttystate, but I believe this
441  was an artifact from before when we used readline. Readline sets
442  the tty state when it needs to.
443  FIXME-maybe: However, query() expects non-raw mode and doesn't
444  use readline. Maybe query should use readline (on the other hand,
445  this only matters for HAVE_SGTTY, not termio or termios, I think). */
446 
447  /* Set tty state to our_ttystate. We don't change in our out of raw
448  mode, to avoid flushing input. We need to do the same thing
449  regardless of output_only, because we don't have separate
450  terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
451  though, since readline will deal with raw mode when/if it needs
452  to. */
453 
455  tinfo->ttystate);
456 
457  if (job_control)
458  {
459 #ifdef HAVE_TERMIOS
461 #if 0
462  /* This fails on Ultrix with EINVAL if you run the testsuite
463  in the background with nohup, and then log out. GDB never
464  used to check for an error here, so perhaps there are other
465  such situations as well. */
466  if (result == -1)
468  "[tcsetpgrp failed in child_terminal_ours: %s]\n",
469  safe_strerror (errno));
470 #endif
471 #endif /* termios */
472 
473 #ifdef HAVE_SGTTY
474  result = ioctl (0, TIOCSPGRP, &our_terminal_info.process_group);
475 #endif
476  }
477 
478 #ifdef SIGTTOU
479  if (job_control)
480  signal (SIGTTOU, osigttou);
481 #endif
482 
483  if (!job_control)
484  {
485  signal (SIGINT, sigint_ours);
486 #ifdef SIGQUIT
487  signal (SIGQUIT, sigquit_ours);
488 #endif
489  }
490 
491 #ifdef F_GETFL
492  tinfo->tflags = fcntl (0, F_GETFL, 0);
493 
494  /* Is there a reason this is being done twice? It happens both
495  places we use F_SETFL, so I'm inclined to think perhaps there
496  is some reason, however perverse. Perhaps not though... */
497  result = fcntl (0, F_SETFL, our_terminal_info.tflags);
498  result = fcntl (0, F_SETFL, our_terminal_info.tflags);
499 #endif
500  }
501 }
502 
503 /* Per-inferior data key. */
504 static const struct inferior_data *inflow_inferior_data;
505 
506 static void
508 {
509  struct terminal_info *info = arg;
510 
511  xfree (info->run_terminal);
512  xfree (info->ttystate);
513  xfree (info);
514 }
515 
516 /* Get the current svr4 data. If none is found yet, add it now. This
517  function always returns a valid object. */
518 
519 static struct terminal_info *
521 {
522  struct terminal_info *info;
523 
524  info = inferior_data (inf, inflow_inferior_data);
525  if (info == NULL)
526  {
527  info = XCNEW (struct terminal_info);
528  set_inferior_data (inf, inflow_inferior_data, info);
529  }
530 
531  return info;
532 }
533 
534 /* This is a "inferior_exit" observer. Releases the TERMINAL_INFO member
535  of the inferior structure. This field is private to inflow.c, and
536  its type is opaque to the rest of GDB. PID is the target pid of
537  the inferior that is about to be removed from the inferior
538  list. */
539 
540 static void
542 {
543  struct terminal_info *info;
544 
545  info = inferior_data (inf, inflow_inferior_data);
546  if (info != NULL)
547  {
548  xfree (info->run_terminal);
549  xfree (info->ttystate);
550  xfree (info);
551  set_inferior_data (inf, inflow_inferior_data, NULL);
552  }
553 }
554 
555 void
557 {
558  struct terminal_info *tinfo_to, *tinfo_from;
559 
560  tinfo_to = get_inflow_inferior_data (to);
561  tinfo_from = get_inflow_inferior_data (from);
562 
563  xfree (tinfo_to->run_terminal);
564  xfree (tinfo_to->ttystate);
565 
566  *tinfo_to = *tinfo_from;
567 
568  if (tinfo_from->run_terminal)
569  tinfo_to->run_terminal
570  = xstrdup (tinfo_from->run_terminal);
571 
572  if (tinfo_from->ttystate)
573  tinfo_to->ttystate
574  = serial_copy_tty_state (stdin_serial, tinfo_from->ttystate);
575 }
576 
577 void
578 term_info (char *arg, int from_tty)
579 {
580  target_terminal_info (arg, from_tty);
581 }
582 
583 void
584 child_terminal_info (struct target_ops *self, const char *args, int from_tty)
585 {
586  struct inferior *inf;
587  struct terminal_info *tinfo;
588 
589  if (!gdb_has_a_terminal ())
590  {
591  printf_filtered (_("This GDB does not control a terminal.\n"));
592  return;
593  }
594 
596  return;
597 
598  inf = current_inferior ();
599  tinfo = get_inflow_inferior_data (inf);
600 
601  printf_filtered (_("Inferior's terminal status "
602  "(currently saved by GDB):\n"));
603 
604  /* First the fcntl flags. */
605  {
606  int flags;
607 
608  flags = tinfo->tflags;
609 
610  printf_filtered ("File descriptor flags = ");
611 
612 #ifndef O_ACCMODE
613 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
614 #endif
615  /* (O_ACCMODE) parens are to avoid Ultrix header file bug. */
616  switch (flags & (O_ACCMODE))
617  {
618  case O_RDONLY:
619  printf_filtered ("O_RDONLY");
620  break;
621  case O_WRONLY:
622  printf_filtered ("O_WRONLY");
623  break;
624  case O_RDWR:
625  printf_filtered ("O_RDWR");
626  break;
627  }
628  flags &= ~(O_ACCMODE);
629 
630 #ifdef O_NONBLOCK
631  if (flags & O_NONBLOCK)
632  printf_filtered (" | O_NONBLOCK");
633  flags &= ~O_NONBLOCK;
634 #endif
635 
636 #if defined (O_NDELAY)
637  /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
638  print it as O_NONBLOCK, which is good cause that is what POSIX
639  has, and the flag will already be cleared by the time we get here. */
640  if (flags & O_NDELAY)
641  printf_filtered (" | O_NDELAY");
642  flags &= ~O_NDELAY;
643 #endif
644 
645  if (flags & O_APPEND)
646  printf_filtered (" | O_APPEND");
647  flags &= ~O_APPEND;
648 
649 #if defined (O_BINARY)
650  if (flags & O_BINARY)
651  printf_filtered (" | O_BINARY");
652  flags &= ~O_BINARY;
653 #endif
654 
655  if (flags)
656  printf_filtered (" | 0x%x", flags);
657  printf_filtered ("\n");
658  }
659 
660 #ifdef PROCESS_GROUP_TYPE
661  printf_filtered ("Process group = %d\n", (int) tinfo->process_group);
662 #endif
663 
664  serial_print_tty_state (stdin_serial, tinfo->ttystate, gdb_stdout);
665 }
666 
667 /* NEW_TTY_PREFORK is called before forking a new child process,
668  so we can record the state of ttys in the child to be formed.
669  TTYNAME is null if we are to share the terminal with gdb;
670  or points to a string containing the name of the desired tty.
671 
672  NEW_TTY is called in new child processes under Unix, which will
673  become debugger target processes. This actually switches to
674  the terminal specified in the NEW_TTY_PREFORK call. */
675 
676 void
677 new_tty_prefork (const char *ttyname)
678 {
679  /* Save the name for later, for determining whether we and the child
680  are sharing a tty. */
681  inferior_thisrun_terminal = ttyname;
682 }
683 
684 #if !defined(__GO32__) && !defined(_WIN32)
685 /* If RESULT, assumed to be the return value from a system call, is
686  negative, print the error message indicated by errno and exit.
687  MSG should identify the operation that failed. */
688 static void
689 check_syscall (const char *msg, int result)
690 {
691  if (result < 0)
692  {
693  print_sys_errmsg (msg, errno);
694  _exit (1);
695  }
696 }
697 #endif
698 
699 void
700 new_tty (void)
701 {
702  int tty;
703 
704  if (inferior_thisrun_terminal == 0)
705  return;
706 #if !defined(__GO32__) && !defined(_WIN32)
707 #ifdef TIOCNOTTY
708  /* Disconnect the child process from our controlling terminal. On some
709  systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
710  ignore SIGTTOU. */
711  tty = open ("/dev/tty", O_RDWR);
712  if (tty > 0)
713  {
714  void (*osigttou) ();
715 
716  osigttou = (void (*)()) signal (SIGTTOU, SIG_IGN);
717  ioctl (tty, TIOCNOTTY, 0);
718  close (tty);
719  signal (SIGTTOU, osigttou);
720  }
721 #endif
722 
723  /* Now open the specified new terminal. */
724  tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY);
726 
727  /* Avoid use of dup2; doesn't exist on all systems. */
728  if (tty != 0)
729  {
730  close (0);
731  check_syscall ("dup'ing tty into fd 0", dup (tty));
732  }
733  if (tty != 1)
734  {
735  close (1);
736  check_syscall ("dup'ing tty into fd 1", dup (tty));
737  }
738  if (tty != 2)
739  {
740  close (2);
741  check_syscall ("dup'ing tty into fd 2", dup (tty));
742  }
743 
744 #ifdef TIOCSCTTY
745  /* Make tty our new controlling terminal. */
746  if (ioctl (tty, TIOCSCTTY, 0) == -1)
747  /* Mention GDB in warning because it will appear in the inferior's
748  terminal instead of GDB's. */
749  warning (_("GDB: Failed to set controlling terminal: %s"),
750  safe_strerror (errno));
751 #endif
752 
753  if (tty > 2)
754  close (tty);
755 #endif /* !go32 && !win32 */
756 }
757 
758 /* NEW_TTY_POSTFORK is called after forking a new child process, and
759  adding it to the inferior table, to store the TTYNAME being used by
760  the child, or null if it sharing the terminal with gdb. */
761 
762 void
764 {
765  /* Save the name for later, for determining whether we and the child
766  are sharing a tty. */
767 
769  {
770  struct inferior *inf = current_inferior ();
771  struct terminal_info *tinfo = get_inflow_inferior_data (inf);
772 
773  tinfo->run_terminal = xstrdup (inferior_thisrun_terminal);
774  }
775 
777 }
778 
779 
780 /* Call set_sigint_trap when you need to pass a signal on to an attached
781  process when handling SIGINT. */
782 
783 static void
784 pass_signal (int signo)
785 {
786 #ifndef _WIN32
787  kill (ptid_get_pid (inferior_ptid), SIGINT);
788 #endif
789 }
790 
791 static void (*osig) ();
792 static int osig_set;
793 
794 void
796 {
797  struct inferior *inf = current_inferior ();
798  struct terminal_info *tinfo = get_inflow_inferior_data (inf);
799 
800  if (inf->attach_flag || tinfo->run_terminal)
801  {
802  osig = (void (*)()) signal (SIGINT, pass_signal);
803  osig_set = 1;
804  }
805  else
806  osig_set = 0;
807 }
808 
809 void
811 {
812  if (osig_set)
813  {
814  signal (SIGINT, osig);
815  osig_set = 0;
816  }
817 }
818 
819 
820 /* Create a new session if the inferior will run in a different tty.
821  A session is UNIX's way of grouping processes that share a controlling
822  terminal, so a new one is needed if the inferior terminal will be
823  different from GDB's.
824 
825  Returns the session id of the new session, 0 if no session was created
826  or -1 if an error occurred. */
827 pid_t
829 {
830 #ifdef HAVE_SETSID
831  pid_t ret;
832 
834  return 0;
835 
836  ret = setsid ();
837  if (ret == -1)
838  warning (_("Failed to create new terminal session: setsid: %s"),
839  safe_strerror (errno));
840 
841  return ret;
842 #else
843  return 0;
844 #endif /* HAVE_SETSID */
845 }
846 
847 /* This is here because this is where we figure out whether we (probably)
848  have job control. Just using job_control only does part of it because
849  setpgid or setpgrp might not exist on a system without job control.
850  It might be considered misplaced (on the other hand, process groups and
851  job control are closely related to ttys).
852 
853  For a more clean implementation, in libiberty, put a setpgid which merely
854  calls setpgrp and a setpgrp which does nothing (any system with job control
855  will have one or the other). */
856 int
858 {
859  int retval = 0;
860 
861  if (job_control)
862  {
863 #if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
864 #ifdef HAVE_SETPGID
865  /* The call setpgid (0, 0) is supposed to work and mean the same
866  thing as this, but on Ultrix 4.2A it fails with EPERM (and
867  setpgid (getpid (), getpid ()) succeeds). */
868  retval = setpgid (getpid (), getpid ());
869 #else
870 #ifdef HAVE_SETPGRP
871 #ifdef SETPGRP_VOID
872  retval = setpgrp ();
873 #else
874  retval = setpgrp (getpid (), getpid ());
875 #endif
876 #endif /* HAVE_SETPGRP */
877 #endif /* HAVE_SETPGID */
878 #endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
879  }
880 
881  return retval;
882 }
883 
884 /* Get all the current tty settings (including whether we have a
885  tty at all!). We can't do this in _initialize_inflow because
886  serial_fdopen() won't work until the serial_ops_list is
887  initialized, but we don't want to do it lazily either, so
888  that we can guarantee stdin_serial is opened if there is
889  a terminal. */
890 void
892 {
893  stdin_serial = serial_fdopen (0);
894 }
895 
896 void
898 {
899  add_info ("terminal", term_info,
900  _("Print inferior's saved terminal status."));
901 
902  add_setshow_auto_boolean_cmd ("interactive-mode", class_support,
903  &interactive_mode, _("\
904 Set whether GDB's standard input is a terminal."), _("\
905 Show whether GDB's standard input is a terminal."), _("\
906 If on, GDB assumes that standard input is a terminal. In practice, it\n\
907 means that GDB should wait for the user to answer queries associated to\n\
908 commands entered at the command prompt. If off, GDB assumes that standard\n\
909 input is not a terminal, and uses the default answer to all queries.\n\
910 If auto (the default), determine which mode to use based on the standard\n\
911 input settings."),
912  NULL,
914  &setlist, &showlist);
915 
916  terminal_is_ours = 1;
917 
918  /* OK, figure out whether we have job control. If neither termios nor
919  sgtty (i.e. termio or go32), leave job_control 0. */
920 
921 #if defined (HAVE_TERMIOS)
922  /* Do all systems with termios have the POSIX way of identifying job
923  control? I hope so. */
924 #ifdef _POSIX_JOB_CONTROL
925  job_control = 1;
926 #else
927 #ifdef _SC_JOB_CONTROL
928  job_control = sysconf (_SC_JOB_CONTROL);
929 #else
930  job_control = 0; /* Have to assume the worst. */
931 #endif /* _SC_JOB_CONTROL */
932 #endif /* _POSIX_JOB_CONTROL */
933 #endif /* HAVE_TERMIOS */
934 
935 #ifdef HAVE_SGTTY
936 #ifdef TIOCGPGRP
937  job_control = 1;
938 #else
939  job_control = 0;
940 #endif /* TIOCGPGRP */
941 #endif /* sgtty */
942 
944 
946  = register_inferior_data_with_cleanup (NULL, inflow_inferior_data_cleanup);
947 }
#define target_terminal_info(arg, from_tty)
Definition: target.h:1510
int terminal_is_ours
Definition: inflow.c:118
void set_sigint_trap(void)
Definition: inflow.c:795
void child_terminal_info(struct target_ops *self, const char *args, int from_tty)
Definition: inflow.c:584
int ptid_equal(ptid_t ptid1, ptid_t ptid2)
Definition: ptid.c:76
void serial_print_tty_state(struct serial *scb, serial_ttystate ttystate, struct ui_file *stream)
Definition: serial.c:500
void xfree(void *)
Definition: common-utils.c:97
void new_tty_prefork(const char *ttyname)
Definition: inflow.c:677
void new_tty_postfork(void)
Definition: inflow.c:763
void warning(const char *fmt,...)
Definition: errors.c:26
void new_tty(void)
Definition: inflow.c:700
tuple inf
Definition: arm-linux.py:13
struct ui_file * gdb_stdout
Definition: main.c:71
static void(* sigint_ours)()
Definition: inflow.c:104
void print_sys_errmsg(const char *string, int errcode)
Definition: utils.c:1001
static void(* osig)()
Definition: inflow.c:791
static void check_syscall(const char *msg, int result)
Definition: inflow.c:689
struct observer * observer_attach_inferior_exit(observer_inferior_exit_ftype *f)
#define _(String)
Definition: gdb_locale.h:40
static PROCESS_GROUP_TYPE gdb_getpgrp(void)
Definition: inflow.c:122
void set_initial_gdb_ttystate(void)
Definition: inflow.c:166
int gdb_has_a_terminal(void)
Definition: inflow.c:173
void printf_filtered(const char *format,...)
Definition: utils.c:2388
int serial_set_tty_state(struct serial *scb, serial_ttystate ttystate)
Definition: serial.c:494
char * run_terminal
Definition: inflow.c:61
mach_port_t kern_return_t mach_port_t msgports mach_port_t kern_return_t pid_t pid mach_port_t kern_return_t mach_port_t task mach_port_t kern_return_t int flags
Definition: gnu-nat.c:1885
struct cmd_list_element * setlist
Definition: cli-cmds.c:135
struct serial * serial_fdopen(const int fd)
Definition: serial.c:291
void add_setshow_auto_boolean_cmd(const char *name, enum command_class theclass, enum auto_boolean *var, const char *set_doc, const char *show_doc, const char *help_doc, cmd_sfunc_ftype *set_func, show_value_ftype *show_func, struct cmd_list_element **set_list, struct cmd_list_element **show_list)
Definition: cli-decode.c:516
int * from
Definition: varobj.h:282
static int osig_set
Definition: inflow.c:792
static void child_terminal_ours_1(int)
Definition: inflow.c:395
#define PROCESS_GROUP_TYPE
Definition: inflow.h:26
void gdb_save_tty_state(void)
Definition: inflow.c:256
static void show_interactive_mode(struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value)
Definition: inflow.c:151
void fprintf_filtered(struct ui_file *stream, const char *format,...)
Definition: utils.c:2351
static struct terminal_info our_terminal_info
Definition: inflow.c:80
static const struct inferior_data * inflow_inferior_data
Definition: inflow.c:504
static void pass_signal(int)
Definition: inflow.c:784
int job_control
void fprintf_unfiltered(struct ui_file *stream, const char *format,...)
Definition: utils.c:2361
struct cmd_list_element * showlist
Definition: cli-cmds.c:143
PROCESS_GROUP_TYPE process_group
Definition: inflow.c:69
void term_info(char *arg, int from_tty)
Definition: inflow.c:578
static serial_ttystate initial_gdb_ttystate
Definition: inflow.c:84
void child_terminal_init_with_pgrp(int pgrp)
Definition: inflow.c:226
Definition: inflow.c:141
void clear_sigint_trap(void)
Definition: inflow.c:810
struct cmd_list_element * add_info(const char *name, cmd_cfunc_ftype *fun, const char *doc)
Definition: cli-decode.c:857
Definition: gnu-nat.c:163
Definition: serial.h:227
static enum auto_boolean interactive_mode
Definition: inflow.c:146
void _initialize_inflow(void)
Definition: inflow.c:897
static struct terminal_info * get_inflow_inferior_data(struct inferior *)
Definition: inflow.c:520
serial_ttystate ttystate
Definition: inflow.c:65
serial_ttystate serial_get_tty_state(struct serial *scb)
Definition: serial.c:482
int attach_flag
Definition: inferior.h:340
void child_terminal_init(struct target_ops *self)
Definition: inflow.c:266
static const char * inferior_thisrun_terminal
Definition: inflow.c:112
Definition: value.c:172
void initialize_stdin_serial(void)
Definition: inflow.c:891
int ptid_get_pid(ptid_t ptid)
Definition: ptid.c:52
static struct serial * stdin_serial
Definition: inflow.c:51
static void inflow_inferior_exit(struct inferior *inf)
Definition: inflow.c:541
void child_terminal_ours(struct target_ops *self)
Definition: inflow.c:385
serial_ttystate serial_copy_tty_state(struct serial *scb, serial_ttystate ttystate)
Definition: serial.c:488
#define O_BINARY
Definition: defs.h:100
ptid_t null_ptid
Definition: ptid.c:25
int gdb_setpgid(void)
Definition: inflow.c:857
int serial_noflush_set_tty_state(struct serial *scb, serial_ttystate new_ttystate, serial_ttystate old_ttystate)
Definition: serial.c:508
struct ui_file * gdb_stderr
Definition: main.c:72
ptid_t inferior_ptid
Definition: infcmd.c:124
char * safe_strerror(int)
#define O_ACCMODE
Definition: inflow.c:141
static void inflow_inferior_data_cleanup(struct inferior *inf, void *arg)
Definition: inflow.c:507
struct inferior * current_inferior(void)
Definition: inferior.c:57
auto_boolean
Definition: defs.h:196
#define OOPSY(what)
Definition: inflow.c:217
void child_terminal_ours_for_output(struct target_ops *self)
Definition: inflow.c:371
void * serial_ttystate
Definition: serial.h:27
int tcsetpgrp(int fd, pid_t pgid)
Definition: go32-nat.c:2140
void child_terminal_inferior(struct target_ops *self)
Definition: inflow.c:287
pid_t tcgetpgrp(int fd)
Definition: go32-nat.c:2131
#define O_NOCTTY
Definition: inflow.c:40
int int * to
Definition: varobj.h:282
PROCESS_GROUP_TYPE inferior_process_group(void)
Definition: inflow.c:93
int tflags
Definition: inflow.c:73
pid_t create_tty_session(void)
Definition: inflow.c:828
static void(* sigquit_ours)()
Definition: inflow.c:105
void copy_terminal_info(struct inferior *to, struct inferior *from)
Definition: inflow.c:556
enum @89 gdb_has_a_terminal_flag