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/tmp/gdb-8.1/gdb/fork-child.c
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1 /* Fork a Unix child process, and set up to debug it, for GDB.
2
3 Copyright (C) 1990-2018 Free Software Foundation, Inc.
4
5 Contributed by Cygnus Support.
6
7 This file is part of GDB.
8
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.
13
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.
18
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/>. */
21
22 #include "defs.h"
23 #include "inferior.h"
24 #include "gdbcmd.h"
25 #include "terminal.h"
26 #include "gdbthread.h"
27 #include "top.h"
28 #include "job-control.h"
29 #include "filestuff.h"
30 #include "nat/fork-inferior.h"
31 #include "common/common-inferior.h"
32
33 /* The exec-wrapper, if any, that will be used when starting the
34 inferior. */
35
36 static char *exec_wrapper = NULL;
37
38 /* See common/common-inferior.h. */
39
40 const char *
41 get_exec_wrapper ()
42 {
43 return exec_wrapper;
44 }
45
46 /* See nat/fork-inferior.h. */
47
48 void
49 gdb_flush_out_err ()
50 {
51 gdb_flush (main_ui->m_gdb_stdout);
52 gdb_flush (main_ui->m_gdb_stderr);
53 }
54
55 /* The ui structure that will be saved on 'prefork_hook' and
56 restored on 'postfork_hook'. */
57 static struct ui *saved_ui = NULL;
58
59 /* See nat/fork-inferior.h. */
60
61 void
62 prefork_hook (const char *args)
63 {
64 const char *inferior_io_terminal = get_inferior_io_terminal ();
65
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;
70
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);
74 }
75
76 /* See nat/fork-inferior.h. */
77
78 void
79 postfork_hook (pid_t pid)
80 {
81 struct inferior *inf;
82
83 if (!have_inferiors ())
84 init_thread_list ();
85
86 inf = current_inferior ();
87
88 inferior_appeared (inf, pid);
89
90 /* Needed for wait_for_inferior stuff. */
91 inferior_ptid = pid_to_ptid (pid);
92
93 gdb_assert (saved_ui != NULL);
94 current_ui = saved_ui;
95 saved_ui = NULL;
96
97 new_tty_postfork ();
98 }
99
100 /* See nat/fork-inferior.h. */
101
102 void
103 postfork_child_hook ()
104 {
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
107 for debugging. */
108 static int debug_setpgrp = 657473;
109
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;
113
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)
117 {
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"));
123 }
124
125 /* Ask the tty subsystem to switch to the one we specified
126 earlier (or to share the current terminal, if none was
127 specified). */
128 new_tty ();
129 }
130
131 /* See inferior.h. */
132
133 ptid_t
134 gdb_startup_inferior (pid_t pid, int num_traps)
135 {
136 ptid_t ptid = startup_inferior (pid, num_traps, NULL, NULL);
137
138 /* Mark all threads non-executing. */
139 set_executing (ptid, 0);
140
141 return ptid;
142 }
143
144 /* Implement the "unset exec-wrapper" command. */
145
146 static void
147 unset_exec_wrapper_command (const char *args, int from_tty)
148 {
149 xfree (exec_wrapper);
150 exec_wrapper = NULL;
151 }
152
153 static void
154 show_startup_with_shell (struct ui_file *file, int from_tty,
155 struct cmd_list_element *c, const char *value)
156 {
157 fprintf_filtered (file,
158 _("Use of shell to start subprocesses is %s.\n"),
159 value);
160 }
161
162 void
163 _initialize_fork_child (void)
164 {
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."),
168 _("\
169 Show the wrapper for running programs."), NULL,
170 NULL, NULL,
171 &setlist, &showlist);
172
173 add_cmd ("exec-wrapper", class_run, unset_exec_wrapper_command,
174 _("Disable use of an execution wrapper."),
175 &unsetlist);
176
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,
181 NULL,
182 show_startup_with_shell,
183 &setlist, &showlist);
184 }
top.h
add_setshow_filename_cmd
void add_setshow_filename_cmd(const char *name, enum command_class theclass, char **var, const char *set_doc, const char *show_doc, const char *help_doc, cmd_const_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:591
startup_inferior
ptid_t startup_inferior(pid_t pid, int ntraps, struct target_waitstatus *last_waitstatus, ptid_t *last_ptid)
Definition: fork-inferior.c:472
gdb_setpgid
int gdb_setpgid()
Definition: job-control.c:41
current_ui
struct ui * current_ui
Definition: event-top.c:453
have_inferiors
int have_inferiors(void)
Definition: inferior.c:408
exec_wrapper
static char * exec_wrapper
Definition: fork-child.c:36
xfree
void xfree(void *)
pid
mach_port_t mach_port_t name mach_port_t mach_port_t name kern_return_t int int rusage_t pid_t pid
Definition: gnu-nat.c:1824
new_tty_prefork
void new_tty_prefork(const char *ttyname)
Definition: inflow.c:587
job-control.h
class_support
Definition: command.h:42
cmd_list_element
Definition: cli-decode.h:46
new_tty_postfork
void new_tty_postfork(void)
Definition: inflow.c:671
gdb_flush_out_err
void gdb_flush_out_err()
Definition: fork-child.c:49
new_tty
void new_tty(void)
Definition: inflow.c:610
inferior
Definition: inferior.h:310
prefork_hook
void prefork_hook(const char *args)
Definition: fork-child.c:62
add_cmd
struct cmd_list_element * add_cmd(const char *name, enum command_class theclass, const char *doc, struct cmd_list_element **list)
Definition: cli-decode.c:262
_
#define _(String)
Definition: gdb_locale.h:35
ui_file
Definition: ui-file.h:26
defs.h
show_startup_with_shell
static void show_startup_with_shell(struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value)
Definition: fork-child.c:154
arm-linux.inf
inf
Definition: arm-linux.py:13
terminal.h
setlist
struct cmd_list_element * setlist
Definition: cli-cmds.c:111
get_exec_wrapper
const char * get_exec_wrapper()
Definition: fork-child.c:41
unset_exec_wrapper_command
static void unset_exec_wrapper_command(const char *args, int from_tty)
Definition: fork-child.c:147
get_inferior_io_terminal
const char * get_inferior_io_terminal(void)
Definition: infcmd.c:131
fprintf_filtered
void fprintf_filtered(struct ui_file *stream, const char *format,...)
Definition: utils.c:2008
ptid_t
Definition: ptid.h:35
showlist
struct cmd_list_element * showlist
Definition: cli-cmds.c:119
pid_to_ptid
ptid_t pid_to_ptid(int pid)
Definition: ptid.c:39
gdbthread.h
inferior.h
unsetlist
struct cmd_list_element * unsetlist
Definition: cli-cmds.c:115
main_ui
struct ui * main_ui
Definition: event-top.c:452
inf
Definition: gnu-nat.c:174
ui
Definition: top.h:56
gdb_startup_inferior
ptid_t gdb_startup_inferior(pid_t pid, int num_traps)
Definition: fork-child.c:134
ui::m_gdb_stdout
struct ui_file * m_gdb_stdout
Definition: top.h:139
gdb_assert
#define gdb_assert(expr)
Definition: gdb_assert.h:32
value
Definition: value.c:169
saved_ui
static struct ui * saved_ui
Definition: fork-child.c:57
fork-inferior.h
postfork_hook
void postfork_hook(pid_t pid)
Definition: fork-child.c:79
inferior_ptid
ptid_t inferior_ptid
Definition: infcmd.c:94
_initialize_fork_child
void _initialize_fork_child(void)
Definition: fork-child.c:163
add_setshow_boolean_cmd
void add_setshow_boolean_cmd(const char *name, enum command_class theclass, int *var, const char *set_doc, const char *show_doc, const char *help_doc, cmd_const_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:569
current_inferior
struct inferior * current_inferior(void)
Definition: inferior.c:58
class_run
Definition: command.h:41
startup_with_shell
int startup_with_shell
Definition: infcmd.c:111
inferior::args
char * args
Definition: inferior.h:352
filestuff.h
gdb_flush
void gdb_flush(struct ui_file *file)
Definition: ui-file.c:93
create_tty_session
pid_t create_tty_session(void)
Definition: inflow.c:736
gdbcmd.h
set_executing
void set_executing(ptid_t ptid, int executing)
Definition: thread.c:991
common-inferior.h
inferior_appeared
void inferior_appeared(struct inferior *inf, int pid)
Definition: inferior.c:268
postfork_child_hook
void postfork_child_hook()
Definition: fork-child.c:103
init_thread_list
void init_thread_list(void)
Definition: thread.c:221
ui::m_gdb_stderr
struct ui_file * m_gdb_stderr
Definition: top.h:143