1 /* Fork a Unix child process, and set up to debug it, for GDB.
3 Copyright (C) 1990-2019 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/>. */
24 /* Local non-gdb includes. */
25 #include "common/common-inferior.h"
26 #include "common/filestuff.h"
27 #include "common/job-control.h"
29 #include "gdbthread.h"
31 #include "nat/fork-inferior.h"
35 /* The exec-wrapper, if any, that will be used when starting the
38 static char *exec_wrapper = NULL;
40 /* See common/common-inferior.h. */
48 /* See nat/fork-inferior.h. */
53 gdb_flush (main_ui->m_gdb_stdout);
54 gdb_flush (main_ui->m_gdb_stderr);
57 /* The ui structure that will be saved on 'prefork_hook' and
58 restored on 'postfork_hook'. */
59 static struct ui *saved_ui = NULL;
61 /* See nat/fork-inferior.h. */
64 prefork_hook (const char *args)
66 const char *inferior_io_terminal = get_inferior_io_terminal ();
68 gdb_assert (saved_ui == NULL);
69 /* Retain a copy of our UI, since the child will replace this value
70 and if we're vforked, we have to restore it. */
71 saved_ui = current_ui;
73 /* Tell the terminal handling subsystem what tty we plan to run on;
74 it will just record the information for later. */
75 new_tty_prefork (inferior_io_terminal);
78 /* See nat/fork-inferior.h. */
81 postfork_hook (pid_t pid)
83 inferior *inf = current_inferior ();
85 inferior_appeared (inf, pid);
87 /* Needed for wait_for_inferior stuff. */
88 inferior_ptid = ptid_t (pid);
90 gdb_assert (saved_ui != NULL);
91 current_ui = saved_ui;
97 /* See nat/fork-inferior.h. */
100 postfork_child_hook ()
102 /* This is set to the result of setpgrp, which if vforked, will be
103 visible to you in the parent process. It's only used by humans
105 static int debug_setpgrp = 657473;
107 /* Make sure we switch to main_ui here in order to be able to
108 use the fprintf_unfiltered/warning/error functions. */
109 current_ui = main_ui;
111 /* Create a new session for the inferior process, if necessary.
112 It will also place the inferior in a separate process group. */
113 if (create_tty_session () <= 0)
115 /* No session was created, but we still want to run the inferior
116 in a separate process group. */
117 debug_setpgrp = gdb_setpgid ();
118 if (debug_setpgrp == -1)
119 perror (_("setpgrp failed in child"));
122 /* Ask the tty subsystem to switch to the one we specified
123 earlier (or to share the current terminal, if none was
128 /* See inferior.h. */
131 gdb_startup_inferior (pid_t pid, int num_traps)
133 ptid_t ptid = startup_inferior (pid, num_traps, NULL, NULL);
135 /* Mark all threads non-executing. */
136 set_executing (ptid, 0);
141 /* Implement the "unset exec-wrapper" command. */
144 unset_exec_wrapper_command (const char *args, int from_tty)
146 xfree (exec_wrapper);
151 show_startup_with_shell (struct ui_file *file, int from_tty,
152 struct cmd_list_element *c, const char *value)
154 fprintf_filtered (file,
155 _("Use of shell to start subprocesses is %s.\n"),
160 _initialize_fork_child (void)
162 add_setshow_filename_cmd ("exec-wrapper", class_run, &exec_wrapper, _("\
163 Set a wrapper for running programs.\n\
164 The wrapper prepares the system and environment for the new program."),
166 Show the wrapper for running programs."), NULL,
168 &setlist, &showlist);
170 add_cmd ("exec-wrapper", class_run, unset_exec_wrapper_command,
171 _("Disable use of an execution wrapper."),
174 add_setshow_boolean_cmd ("startup-with-shell", class_support,
175 &startup_with_shell, _("\
176 Set use of shell to start subprocesses. The default is on."), _("\
177 Show use of shell to start subprocesses."), NULL,
179 show_startup_with_shell,
180 &setlist, &showlist);