1 /* Fork a Unix child process, and set up to debug it, for GDB.
3 Copyright (C) 1990-2017 Free Software Foundation, Inc.
5 Contributed by Cygnus Support.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
26 #include "gdbthread.h"
28 #include "job-control.h"
29 #include "filestuff.h"
30 #include "nat/fork-inferior.h"
31 #include "common/common-inferior.h"
33 /* The exec-wrapper, if any, that will be used when starting the
36 static char *exec_wrapper
= NULL
;
38 /* See common/common-inferior.h. */
46 /* See nat/fork-inferior.h. */
51 gdb_flush (main_ui
->m_gdb_stdout
);
52 gdb_flush (main_ui
->m_gdb_stderr
);
55 /* The ui structure that will be saved on 'prefork_hook' and
56 restored on 'postfork_hook'. */
57 static struct ui
*saved_ui
= NULL
;
59 /* See nat/fork-inferior.h. */
62 prefork_hook (const char *args
)
64 const char *inferior_io_terminal
= get_inferior_io_terminal ();
66 gdb_assert (saved_ui
== NULL
);
67 /* Retain a copy of our UI, since the child will replace this value
68 and if we're vforked, we have to restore it. */
69 saved_ui
= current_ui
;
71 /* Tell the terminal handling subsystem what tty we plan to run on;
72 it will just record the information for later. */
73 new_tty_prefork (inferior_io_terminal
);
76 /* See nat/fork-inferior.h. */
79 postfork_hook (pid_t pid
)
83 if (!have_inferiors ())
86 inf
= current_inferior ();
88 inferior_appeared (inf
, pid
);
90 /* Needed for wait_for_inferior stuff. */
91 inferior_ptid
= pid_to_ptid (pid
);
93 gdb_assert (saved_ui
!= NULL
);
94 current_ui
= saved_ui
;
100 /* See nat/fork-inferior.h. */
103 postfork_child_hook ()
105 /* This is set to the result of setpgrp, which if vforked, will be
106 visible to you in the parent process. It's only used by humans
108 static int debug_setpgrp
= 657473;
110 /* Make sure we switch to main_ui here in order to be able to
111 use the fprintf_unfiltered/warning/error functions. */
112 current_ui
= main_ui
;
114 /* Create a new session for the inferior process, if necessary.
115 It will also place the inferior in a separate process group. */
116 if (create_tty_session () <= 0)
118 /* No session was created, but we still want to run the inferior
119 in a separate process group. */
120 debug_setpgrp
= gdb_setpgid ();
121 if (debug_setpgrp
== -1)
122 perror (_("setpgrp failed in child"));
125 /* Ask the tty subsystem to switch to the one we specified
126 earlier (or to share the current terminal, if none was
131 /* See inferior.h. */
134 gdb_startup_inferior (pid_t pid
, int num_traps
)
136 ptid_t ptid
= startup_inferior (pid
, num_traps
, NULL
, NULL
);
138 /* Mark all threads non-executing. */
139 set_executing (ptid
, 0);
144 /* Implement the "unset exec-wrapper" command. */
147 unset_exec_wrapper_command (const char *args
, int from_tty
)
149 xfree (exec_wrapper
);
154 show_startup_with_shell (struct ui_file
*file
, int from_tty
,
155 struct cmd_list_element
*c
, const char *value
)
157 fprintf_filtered (file
,
158 _("Use of shell to start subprocesses is %s.\n"),
163 _initialize_fork_child (void)
165 add_setshow_filename_cmd ("exec-wrapper", class_run
, &exec_wrapper
, _("\
166 Set a wrapper for running programs.\n\
167 The wrapper prepares the system and environment for the new program."),
169 Show the wrapper for running programs."), NULL
,
171 &setlist
, &showlist
);
173 add_cmd ("exec-wrapper", class_run
, unset_exec_wrapper_command
,
174 _("Disable use of an execution wrapper."),
177 add_setshow_boolean_cmd ("startup-with-shell", class_support
,
178 &startup_with_shell
, _("\
179 Set use of shell to start subprocesses. The default is on."), _("\
180 Show use of shell to start subprocesses."), NULL
,
182 show_startup_with_shell
,
183 &setlist
, &showlist
);