/* Multi-process control for GDB, the GNU debugger.
Copyright (C) 2008-2019 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "exec.h"
#include "inferior.h"
#include "target.h"
#include "command.h"
#include "completer.h"
#include "gdbcmd.h"
#include "gdbthread.h"
#include "ui-out.h"
#include "observable.h"
#include "gdbcore.h"
#include "symfile.h"
#include "common/environ.h"
#include "cli/cli-utils.h"
#include "continuations.h"
#include "arch-utils.h"
#include "target-descriptions.h"
#include "readline/tilde.h"
#include "progspace-and-thread.h"
/* Keep a registry of per-inferior data-pointers required by other GDB
modules. */
DEFINE_REGISTRY (inferior, REGISTRY_ACCESS_FIELD)
struct inferior *inferior_list = NULL;
static int highest_inferior_num;
/* See inferior.h. */
int print_inferior_events = 1;
/* The Current Inferior. This is a strong reference. I.e., whenever
an inferior is the current inferior, its refcount is
incremented. */
static struct inferior *current_inferior_ = NULL;
struct inferior*
current_inferior (void)
{
return current_inferior_;
}
void
set_current_inferior (struct inferior *inf)
{
/* There's always an inferior. */
gdb_assert (inf != NULL);
inf->incref ();
current_inferior_->decref ();
current_inferior_ = inf;
}
private_inferior::~private_inferior () = default;
inferior::~inferior ()
{
inferior *inf = this;
discard_all_inferior_continuations (inf);
inferior_free_data (inf);
xfree (inf->args);
xfree (inf->terminal);
target_desc_info_free (inf->tdesc_info);
}
inferior::inferior (int pid_)
: num (++highest_inferior_num),
pid (pid_),
environment (gdb_environ::from_host_environ ()),
registry_data ()
{
inferior_alloc_data (this);
}
struct inferior *
add_inferior_silent (int pid)
{
inferior *inf = new inferior (pid);
if (inferior_list == NULL)
inferior_list = inf;
else
{
inferior *last;
for (last = inferior_list; last->next != NULL; last = last->next)
;
last->next = inf;
}
gdb::observers::inferior_added.notify (inf);
if (pid != 0)
inferior_appeared (inf, pid);
return inf;
}
struct inferior *
add_inferior (int pid)
{
struct inferior *inf = add_inferior_silent (pid);
if (print_inferior_events)
{
if (pid != 0)
printf_unfiltered (_("[New inferior %d (%s)]\n"),
inf->num,
target_pid_to_str (ptid_t (pid)).c_str ());
else
printf_unfiltered (_("[New inferior %d]\n"), inf->num);
}
return inf;
}
void
delete_inferior (struct inferior *todel)
{
struct inferior *inf, *infprev;
infprev = NULL;
for (inf = inferior_list; inf; infprev = inf, inf = inf->next)
if (inf == todel)
break;
if (!inf)
return;
for (thread_info *tp : inf->threads_safe ())
delete_thread_silent (tp);
if (infprev)
infprev->next = inf->next;
else
inferior_list = inf->next;
gdb::observers::inferior_removed.notify (inf);
/* If this program space is rendered useless, remove it. */
if (program_space_empty_p (inf->pspace))
delete_program_space (inf->pspace);
delete inf;
}
/* If SILENT then be quiet -- don't announce a inferior exit, or the
exit of its threads. */
static void
exit_inferior_1 (struct inferior *inftoex, int silent)
{
struct inferior *inf;
for (inf = inferior_list; inf; inf = inf->next)
if (inf == inftoex)
break;
if (!inf)
return;
for (thread_info *tp : inf->threads_safe ())
{
if (silent)
delete_thread_silent (tp);
else
delete_thread (tp);
}
gdb::observers::inferior_exit.notify (inf);
inf->pid = 0;
inf->fake_pid_p = 0;
inf->priv = NULL;
if (inf->vfork_parent != NULL)
{
inf->vfork_parent->vfork_child = NULL;
inf->vfork_parent = NULL;
}
if (inf->vfork_child != NULL)
{
inf->vfork_child->vfork_parent = NULL;
inf->vfork_child = NULL;
}
inf->pending_detach = 0;
/* Reset it. */
inf->control = inferior_control_state (NO_STOP_QUIETLY);
}
void
exit_inferior (inferior *inf)
{
exit_inferior_1 (inf, 0);
}
void
exit_inferior_silent (int pid)
{
struct inferior *inf = find_inferior_pid (pid);
exit_inferior_1 (inf, 1);
}
void
exit_inferior_silent (inferior *inf)
{
exit_inferior_1 (inf, 1);
}
/* See inferior.h. */
void
detach_inferior (inferior *inf)
{
/* Save the pid, since exit_inferior_1 will reset it. */
int pid = inf->pid;
exit_inferior_1 (inf, 0);
if (print_inferior_events)
printf_unfiltered (_("[Inferior %d (%s) detached]\n"),
inf->num,
target_pid_to_str (ptid_t (pid)).c_str ());
}
void
inferior_appeared (struct inferior *inf, int pid)
{
/* If this is the first inferior with threads, reset the global
thread id. */
if (!any_thread_p ())
init_thread_list ();
inf->pid = pid;
inf->has_exit_code = 0;
inf->exit_code = 0;
gdb::observers::inferior_appeared.notify (inf);
}
void
discard_all_inferiors (void)
{
for (inferior *inf : all_non_exited_inferiors ())
exit_inferior_silent (inf);
}
struct inferior *
find_inferior_id (int num)
{
for (inferior *inf : all_inferiors ())
if (inf->num == num)
return inf;
return NULL;
}
struct inferior *
find_inferior_pid (int pid)
{
/* Looking for inferior pid == 0 is always wrong, and indicative of
a bug somewhere else. There may be more than one with pid == 0,
for instance. */
gdb_assert (pid != 0);
for (inferior *inf : all_inferiors ())
if (inf->pid == pid)
return inf;
return NULL;
}
/* See inferior.h */
struct inferior *
find_inferior_ptid (ptid_t ptid)
{
return find_inferior_pid (ptid.pid ());
}
/* See inferior.h. */
struct inferior *
find_inferior_for_program_space (struct program_space *pspace)
{
struct inferior *cur_inf = current_inferior ();
if (cur_inf->pspace == pspace)
return cur_inf;
for (inferior *inf : all_inferiors ())
if (inf->pspace == pspace)
return inf;
return NULL;
}
struct inferior *
iterate_over_inferiors (int (*callback) (struct inferior *, void *),
void *data)
{
for (inferior *inf : all_inferiors_safe ())
if ((*callback) (inf, data))
return inf;
return NULL;
}
int
have_inferiors (void)
{
for (inferior *inf ATTRIBUTE_UNUSED : all_non_exited_inferiors ())
return 1;
return 0;
}
/* Return the number of live inferiors. We account for the case
where an inferior might have a non-zero pid but no threads, as
in the middle of a 'mourn' operation. */
int
number_of_live_inferiors (void)
{
int num_inf = 0;
for (inferior *inf : all_non_exited_inferiors ())
if (target_has_execution_1 (ptid_t (inf->pid)))
for (thread_info *tp ATTRIBUTE_UNUSED : inf->non_exited_threads ())
{
/* Found a live thread in this inferior, go to the next
inferior. */
++num_inf;
break;
}
return num_inf;
}
/* Return true if there is at least one live inferior. */
int
have_live_inferiors (void)
{
return number_of_live_inferiors () > 0;
}
/* Prune away any unused inferiors, and then prune away no longer used
program spaces. */
void
prune_inferiors (void)
{
struct inferior *ss, **ss_link;
ss = inferior_list;
ss_link = &inferior_list;
while (ss)
{
if (!ss->deletable ()
|| !ss->removable
|| ss->pid != 0)
{
ss_link = &ss->next;
ss = *ss_link;
continue;
}
*ss_link = ss->next;
delete_inferior (ss);
ss = *ss_link;
}
}
/* Simply returns the count of inferiors. */
int
number_of_inferiors (void)
{
auto rng = all_inferiors ();
return std::distance (rng.begin (), rng.end ());
}
/* Converts an inferior process id to a string. Like
target_pid_to_str, but special cases the null process. */
static std::string
inferior_pid_to_str (int pid)
{
if (pid != 0)
return target_pid_to_str (ptid_t (pid));
else
return _("<null>");
}
/* See inferior.h. */
void
print_selected_inferior (struct ui_out *uiout)
{
struct inferior *inf = current_inferior ();
const char *filename = inf->pspace->pspace_exec_filename;
if (filename == NULL)
filename = _("<noexec>");
uiout->message (_("[Switching to inferior %d [%s] (%s)]\n"),
inf->num, inferior_pid_to_str (inf->pid).c_str (), filename);
}
/* Prints the list of inferiors and their details on UIOUT. This is a
version of 'info_inferior_command' suitable for use from MI.
If REQUESTED_INFERIORS is not NULL, it's a list of GDB ids of the
inferiors that should be printed. Otherwise, all inferiors are
printed. */
static void
print_inferior (struct ui_out *uiout, const char *requested_inferiors)
{
int inf_count = 0;
/* Compute number of inferiors we will print. */
for (inferior *inf : all_inferiors ())
{
if (!number_is_in_list (requested_inferiors, inf->num))
continue;
++inf_count;
}
if (inf_count == 0)
{
uiout->message ("No inferiors.\n");
return;
}
ui_out_emit_table table_emitter (uiout, 4, inf_count, "inferiors");
uiout->table_header (1, ui_left, "current", "");
uiout->table_header (4, ui_left, "number", "Num");
uiout->table_header (17, ui_left, "target-id", "Description");
uiout->table_header (17, ui_left, "exec", "Executable");
uiout->table_body ();
for (inferior *inf : all_inferiors ())
{
if (!number_is_in_list (requested_inferiors, inf->num))
continue;
ui_out_emit_tuple tuple_emitter (uiout, NULL);
if (inf == current_inferior ())
uiout->field_string ("current", "*");
else
uiout->field_skip ("current");
uiout->field_int ("number", inf->num);
uiout->field_string ("target-id", inferior_pid_to_str (inf->pid));
if (inf->pspace->pspace_exec_filename != NULL)
uiout->field_string ("exec", inf->pspace->pspace_exec_filename);
else
uiout->field_skip ("exec");
/* Print extra info that isn't really fit to always present in
tabular form. Currently we print the vfork parent/child
relationships, if any. */
if (inf->vfork_parent)
{
uiout->text (_("\n\tis vfork child of inferior "));
uiout->field_int ("vfork-parent", inf->vfork_parent->num);
}
if (inf->vfork_child)
{
uiout->text (_("\n\tis vfork parent of inferior "));
uiout->field_int ("vfork-child", inf->vfork_child->num);
}
uiout->text ("\n");
}
}
static void
detach_inferior_command (const char *args, int from_tty)
{
if (!args || !*args)
error (_("Requires argument (inferior id(s) to detach)"));
number_or_range_parser parser (args);
while (!parser.finished ())
{
int num = parser.get_number ();
inferior *inf = find_inferior_id (num);
if (inf == NULL)
{
warning (_("Inferior ID %d not known."), num);
continue;
}
if (inf->pid == 0)
{
warning (_("Inferior ID %d is not running."), num);
continue;
}
thread_info *tp = any_thread_of_inferior (inf);
if (tp == NULL)
{
warning (_("Inferior ID %d has no threads."), num);
continue;
}
switch_to_thread (tp);
detach_command (NULL, from_tty);
}
}
static void
kill_inferior_command (const char *args, int from_tty)
{
if (!args || !*args)
error (_("Requires argument (inferior id(s) to kill)"));
number_or_range_parser parser (args);
while (!parser.finished ())
{
int num = parser.get_number ();
inferior *inf = find_inferior_id (num);
if (inf == NULL)
{
warning (_("Inferior ID %d not known."), num);
continue;
}
if (inf->pid == 0)
{
warning (_("Inferior ID %d is not running."), num);
continue;
}
thread_info *tp = any_thread_of_inferior (inf);
if (tp == NULL)
{
warning (_("Inferior ID %d has no threads."), num);
continue;
}
switch_to_thread (tp);
target_kill ();
}
bfd_cache_close_all ();
}
static void
inferior_command (const char *args, int from_tty)
{
struct inferior *inf;
int num;
num = parse_and_eval_long (args);
inf = find_inferior_id (num);
if (inf == NULL)
error (_("Inferior ID %d not known."), num);
if (inf->pid != 0)
{
if (inf != current_inferior ())
{
thread_info *tp = any_thread_of_inferior (inf);
if (tp == NULL)
error (_("Inferior has no threads."));
switch_to_thread (tp);
}
gdb::observers::user_selected_context_changed.notify
(USER_SELECTED_INFERIOR
| USER_SELECTED_THREAD
| USER_SELECTED_FRAME);
}
else
{
set_current_inferior (inf);
switch_to_no_thread ();
set_current_program_space (inf->pspace);
gdb::observers::user_selected_context_changed.notify
(USER_SELECTED_INFERIOR);
}
}
/* Print information about currently known inferiors. */
static void
info_inferiors_command (const char *args, int from_tty)
{
print_inferior (current_uiout, args);
}
/* remove-inferior ID */
static void
remove_inferior_command (const char *args, int from_tty)
{
if (args == NULL || *args == '\0')
error (_("Requires an argument (inferior id(s) to remove)"));
number_or_range_parser parser (args);
while (!parser.finished ())
{
int num = parser.get_number ();
struct inferior *inf = find_inferior_id (num);
if (inf == NULL)
{
warning (_("Inferior ID %d not known."), num);
continue;
}
if (!inf->deletable ())
{
warning (_("Can not remove current inferior %d."), num);
continue;
}
if (inf->pid != 0)
{
warning (_("Can not remove active inferior %d."), num);
continue;
}
delete_inferior (inf);
}
}
struct inferior *
add_inferior_with_spaces (void)
{
struct address_space *aspace;
struct program_space *pspace;
struct inferior *inf;
struct gdbarch_info info;
/* If all inferiors share an address space on this system, this
doesn't really return a new address space; otherwise, it
really does. */
aspace = maybe_new_address_space ();
pspace = new program_space (aspace);
inf = add_inferior (0);
inf->pspace = pspace;
inf->aspace = pspace->aspace;
/* Setup the inferior's initial arch, based on information obtained
from the global "set ..." options. */
gdbarch_info_init (&info);
inf->gdbarch = gdbarch_find_by_info (info);
/* The "set ..." options reject invalid settings, so we should
always have a valid arch by now. */
gdb_assert (inf->gdbarch != NULL);
return inf;
}
/* add-inferior [-copies N] [-exec FILENAME] */
static void
add_inferior_command (const char *args, int from_tty)
{
int i, copies = 1;
gdb::unique_xmalloc_ptr<char> exec;
symfile_add_flags add_flags = 0;
if (from_tty)
add_flags |= SYMFILE_VERBOSE;
if (args)
{
gdb_argv built_argv (args);
for (char **argv = built_argv.get (); *argv != NULL; argv++)
{
if (**argv == '-')
{
if (strcmp (*argv, "-copies") == 0)
{
++argv;
if (!*argv)
error (_("No argument to -copies"));
copies = parse_and_eval_long (*argv);
}
else if (strcmp (*argv, "-exec") == 0)
{
++argv;
if (!*argv)
error (_("No argument to -exec"));
exec.reset (tilde_expand (*argv));
}
}
else
error (_("Invalid argument"));
}
}
scoped_restore_current_pspace_and_thread restore_pspace_thread;
for (i = 0; i < copies; ++i)
{
struct inferior *inf = add_inferior_with_spaces ();
printf_filtered (_("Added inferior %d\n"), inf->num);
if (exec != NULL)
{
/* Switch over temporarily, while reading executable and
symbols.q. */
set_current_program_space (inf->pspace);
set_current_inferior (inf);
switch_to_no_thread ();
exec_file_attach (exec.get (), from_tty);
symbol_file_add_main (exec.get (), add_flags);
}
}
}
/* clone-inferior [-copies N] [ID] */
static void
clone_inferior_command (const char *args, int from_tty)
{
int i, copies = 1;
struct inferior *orginf = NULL;
if (args)
{
gdb_argv built_argv (args);
char **argv = built_argv.get ();
for (; *argv != NULL; argv++)
{
if (**argv == '-')
{
if (strcmp (*argv, "-copies") == 0)
{
++argv;
if (!*argv)
error (_("No argument to -copies"));
copies = parse_and_eval_long (*argv);
if (copies < 0)
error (_("Invalid copies number"));
}
}
else
{
if (orginf == NULL)
{
int num;
/* The first non-option (-) argument specified the
program space ID. */
num = parse_and_eval_long (*argv);
orginf = find_inferior_id (num);
if (orginf == NULL)
error (_("Inferior ID %d not known."), num);
continue;
}
else
error (_("Invalid argument"));
}
}
}
/* If no inferior id was specified, then the user wants to clone the
current inferior. */
if (orginf == NULL)
orginf = current_inferior ();
scoped_restore_current_pspace_and_thread restore_pspace_thread;
for (i = 0; i < copies; ++i)
{
struct address_space *aspace;
struct program_space *pspace;
struct inferior *inf;
/* If all inferiors share an address space on this system, this
doesn't really return a new address space; otherwise, it
really does. */
aspace = maybe_new_address_space ();
pspace = new program_space (aspace);
inf = add_inferior (0);
inf->pspace = pspace;
inf->aspace = pspace->aspace;
inf->gdbarch = orginf->gdbarch;
/* If the original inferior had a user specified target
description, make the clone use it too. */
if (target_desc_info_from_user_p (inf->tdesc_info))
copy_inferior_target_desc_info (inf, orginf);
printf_filtered (_("Added inferior %d.\n"), inf->num);
set_current_inferior (inf);
switch_to_no_thread ();
clone_program_space (pspace, orginf->pspace);
}
}
/* Print notices when new inferiors are created and die. */
static void
show_print_inferior_events (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
fprintf_filtered (file, _("Printing of inferior events is %s.\n"), value);
}
/* Return a new value for the selected inferior's id. */
static struct value *
inferior_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
void *ignore)
{
struct inferior *inf = current_inferior ();
return value_from_longest (builtin_type (gdbarch)->builtin_int, inf->num);
}
/* Implementation of `$_inferior' variable. */
static const struct internalvar_funcs inferior_funcs =
{
inferior_id_make_value,
NULL,
NULL
};
void
initialize_inferiors (void)
{
struct cmd_list_element *c = NULL;
/* There's always one inferior. Note that this function isn't an
automatic _initialize_foo function, since other _initialize_foo
routines may need to install their per-inferior data keys. We
can only allocate an inferior when all those modules have done
that. Do this after initialize_progspace, due to the
current_program_space reference. */
current_inferior_ = add_inferior_silent (0);
current_inferior_->incref ();
current_inferior_->pspace = current_program_space;
current_inferior_->aspace = current_program_space->aspace;
/* The architecture will be initialized shortly, by
initialize_current_architecture. */
add_info ("inferiors", info_inferiors_command,
_("Print a list of inferiors being managed.\n\
Usage: info inferiors [ID]...\n\
If IDs are specified, the list is limited to just those inferiors.\n\
By default all inferiors are displayed."));
c = add_com ("add-inferior", no_class, add_inferior_command, _("\
Add a new inferior.\n\
Usage: add-inferior [-copies N] [-exec FILENAME]\n\
N is the optional number of inferiors to add, default is 1.\n\
FILENAME is the file name of the executable to use\n\
as main program."));
set_cmd_completer (c, filename_completer);
add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
Remove inferior ID (or list of IDs).\n\
Usage: remove-inferiors ID..."));
add_com ("clone-inferior", no_class, clone_inferior_command, _("\
Clone inferior ID.\n\
Usage: clone-inferior [-copies N] [ID]\n\
Add N copies of inferior ID. The new inferior has the same\n\
executable loaded as the copied inferior. If -copies is not specified,\n\
adds 1 copy. If ID is not specified, it is the current inferior\n\
that is cloned."));
add_cmd ("inferiors", class_run, detach_inferior_command, _("\
Detach from inferior ID (or list of IDS).\n\
Usage; detach inferiors ID..."),
&detachlist);
add_cmd ("inferiors", class_run, kill_inferior_command, _("\
Kill inferior ID (or list of IDs).\n\
Usage: kill inferiors ID..."),
&killlist);
add_cmd ("inferior", class_run, inferior_command, _("\
Use this command to switch between inferiors.\n\
Usage: inferior ID\n\
The new inferior ID must be currently known."),
&cmdlist);
add_setshow_boolean_cmd ("inferior-events", no_class,
&print_inferior_events, _("\
Set printing of inferior events (such as inferior start and exit)."), _("\
Show printing of inferior events (such as inferior start and exit)."), NULL,
NULL,
show_print_inferior_events,
&setprintlist, &showprintlist);
create_internalvar_type_lazy ("_inferior", &inferior_funcs, NULL);
}