binutils-gdb/gdb/cli/cli-interp.c
Pedro Alves 3c216924d6 Make command line editing (use of readline) be per UI
Due to the way that readline's API works (based on globals), we can
only have one instance of readline in a process.  So the goal of this
patch is to only allow editing in the main UI, and make sure that only
one UI calls into readline.  Some MI paths touch readline variables
currently, which is bad as that is changing variables that matter for
the main console UI.  This patch fixes those.

This actually fixes a nasty bug -- starting gdb in MI mode ("gdb
-i=mi"), and then doing "set editing on" crashes GDB, because MI is
not prepared to use readline:

 set editing on
 &"set editing on\n"
 =cmd-param-changed,param="editing",value="on"
 ^done
 (gdb)
 p 1
 readline: readline_callback_read_char() called with no handler!
 Aborted (core dumped)

The fix for that was to add an interp_proc method to query the
interpreter whether it actually supports editing.  New test included.

gdb/ChangeLog:
2016-06-21  Pedro Alves  <palves@redhat.com>

	PR mi/20034
	* cli/cli-interp.c: Include cli-interp.h and event-top.h.
	(cli_interpreter_resume): Pass 1 to gdb_setup_readline.  Set the
	UI's input_handler here.
	(cli_interpreter_supports_command_editing): New function.
	(cli_interp_procs): Install it.
	* cli/cli-interp.h: New file.
	* event-top.c (async_command_editing_p): Rename to ...
	(set_editing_cmd_var): ... this.
	(change_line_handler): Add parameter 'editing', and use it.  Bail
	early if the interpreter doesn't support editing.  Don't touch
	readline state if editing is off.
	(gdb_rl_callback_handler_remove, gdb_rl_callback_handler_install)
	(gdb_rl_callback_handler_reinstall): Assert the current UI is the
	main UI.
	(display_gdb_prompt): Don't call gdb_rl_callback_handler_remove if
	not using readline.  Check whether the current UI is using command
	editing instead of checking the async_command_editing_p global.
	(set_async_editing_command): Delete.
	(gdb_setup_readline): Add 'editing' parameter.  Only allow editing
	on the main UI.  Don't touch readline state if editing is off.
	(gdb_disable_readline): Don't touch readline state if editing is
	off.
	* event-top.h (gdb_setup_readline): Add 'int' parameter.
	(set_async_editing_command): Delete declaration.
	(change_line_handler, command_line_handler): Declare.
	(async_command_editing_p): Rename to ...
	(set_editing_cmd_var): ... this.
	* infrun.c (reinstall_readline_callback_handler_cleanup): Check
	whether the current UI has editing enabled rather than checking
	the async_command_editing_p global.
	* interps.c (interp_supports_command_editing): New function.
	* interps.h (interp_supports_command_editing_ftype): New typedef.
	(struct interp_procs) <supports_command_editing_proc>: New field.
	(interp_supports_command_editing): Declare.
	* mi/mi-interp.c (mi_interpreter_resume): Pass 0 to
	gdb_setup_readline.  Don't clear the async_command_editing_p
	global.  Update comments.
	* top.c (gdb_readline_wrapper_line, gdb_readline_wrapper): Check
	whether the current UI has editing enabled rather than checking
	the async_command_editing_p global.  Don't touch readline state if
	editing is off.
	(undo_terminal_modifications_before_exit): Switch to the main UI.
	Unconditionally call gdb_disable_readline.
	(set_editing): New function.
	(show_async_command_editing_p): Rename to ...
	(show_editing): ... this.  Show the state of the current UI.
	(_initialize_top): Adjust.
	* top.h (struct ui) <command_editing>: New field.
	* tui/tui-interp.c: Include cli/cli-interp.h.
	(tui_resume): Pass 1 to gdb_setup_readline.  Set the UI's
	input_handler.
	(tui_interp_procs): Install
	cli_interpreter_supports_command_editing.
	* tui/tui-io.c (tui_getc): Check whether the current UI has
	editing enabled rather than checking the async_command_editing_p
	global.

gdb/testsuite/ChangeLog:
2016-06-21  Pedro Alves  <palves@redhat.com>

	PR mi/20034
	* gdb.mi/mi-editing.exp: New file.
2016-06-21 01:11:48 +01:00

349 lines
8.5 KiB
C

/* CLI Definitions for GDB, the GNU debugger.
Copyright (C) 2002-2016 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 "cli-interp.h"
#include "interps.h"
#include "event-top.h"
#include "ui-out.h"
#include "cli-out.h"
#include "top.h" /* for "execute_command" */
#include "event-top.h"
#include "infrun.h"
#include "observer.h"
/* The console interpreter. */
struct cli_interp
{
/* The ui_out for the console interpreter. */
struct ui_out *cli_uiout;
};
/* Returns the INTERP's data cast as cli_interp if INTERP is a CLI,
and returns NULL otherwise. */
static struct cli_interp *
as_cli_interp (struct interp *interp)
{
if (strcmp (interp_name (interp), INTERP_CONSOLE) == 0)
return (struct cli_interp *) interp_data (interp);
return NULL;
}
/* Longjmp-safe wrapper for "execute_command". */
static struct gdb_exception safe_execute_command (struct ui_out *uiout,
char *command,
int from_tty);
/* Observers for several run control events. If the interpreter is
quiet (i.e., another interpreter is being run with
interpreter-exec), print nothing. */
/* Observer for the normal_stop notification. */
static void
cli_on_normal_stop (struct bpstats *bs, int print_frame)
{
struct switch_thru_all_uis state;
SWITCH_THRU_ALL_UIS (state)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
continue;
if (print_frame)
print_stop_event (cli->cli_uiout);
}
}
/* Observer for the signal_received notification. */
static void
cli_on_signal_received (enum gdb_signal siggnal)
{
struct switch_thru_all_uis state;
SWITCH_THRU_ALL_UIS (state)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
continue;
print_signal_received_reason (cli->cli_uiout, siggnal);
}
}
/* Observer for the end_stepping_range notification. */
static void
cli_on_end_stepping_range (void)
{
struct switch_thru_all_uis state;
SWITCH_THRU_ALL_UIS (state)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
continue;
print_end_stepping_range_reason (cli->cli_uiout);
}
}
/* Observer for the signalled notification. */
static void
cli_on_signal_exited (enum gdb_signal siggnal)
{
struct switch_thru_all_uis state;
SWITCH_THRU_ALL_UIS (state)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
continue;
print_signal_exited_reason (cli->cli_uiout, siggnal);
}
}
/* Observer for the exited notification. */
static void
cli_on_exited (int exitstatus)
{
struct switch_thru_all_uis state;
SWITCH_THRU_ALL_UIS (state)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
continue;
print_exited_reason (cli->cli_uiout, exitstatus);
}
}
/* Observer for the no_history notification. */
static void
cli_on_no_history (void)
{
struct switch_thru_all_uis state;
SWITCH_THRU_ALL_UIS (state)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
continue;
print_no_history_reason (cli->cli_uiout);
}
}
/* Observer for the sync_execution_done notification. */
static void
cli_on_sync_execution_done (void)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
return;
display_gdb_prompt (NULL);
}
/* Observer for the command_error notification. */
static void
cli_on_command_error (void)
{
struct cli_interp *cli = as_cli_interp (top_level_interpreter ());
if (cli == NULL)
return;
display_gdb_prompt (NULL);
}
/* These implement the cli out interpreter: */
static void *
cli_interpreter_init (struct interp *self, int top_level)
{
return interp_data (self);
}
static int
cli_interpreter_resume (void *data)
{
struct ui *ui = current_ui;
struct cli_interp *cli = (struct cli_interp *) data;
struct ui_file *stream;
/*sync_execution = 1; */
/* gdb_setup_readline will change gdb_stdout. If the CLI was
previously writing to gdb_stdout, then set it to the new
gdb_stdout afterwards. */
stream = cli_out_set_stream (cli->cli_uiout, gdb_stdout);
if (stream != gdb_stdout)
{
cli_out_set_stream (cli->cli_uiout, stream);
stream = NULL;
}
gdb_setup_readline (1);
ui->input_handler = command_line_handler;
if (stream != NULL)
cli_out_set_stream (cli->cli_uiout, gdb_stdout);
return 1;
}
static int
cli_interpreter_suspend (void *data)
{
gdb_disable_readline ();
return 1;
}
static struct gdb_exception
cli_interpreter_exec (void *data, const char *command_str)
{
struct cli_interp *cli = (struct cli_interp *) data;
struct ui_file *old_stream;
struct gdb_exception result;
/* FIXME: cagney/2003-02-01: Need to const char *propogate
safe_execute_command. */
char *str = (char *) alloca (strlen (command_str) + 1);
strcpy (str, command_str);
/* gdb_stdout could change between the time cli_uiout was
initialized and now. Since we're probably using a different
interpreter which has a new ui_file for gdb_stdout, use that one
instead of the default.
It is important that it gets reset everytime, since the user
could set gdb to use a different interpreter. */
old_stream = cli_out_set_stream (cli->cli_uiout, gdb_stdout);
result = safe_execute_command (cli->cli_uiout, str, 1);
cli_out_set_stream (cli->cli_uiout, old_stream);
return result;
}
int
cli_interpreter_supports_command_editing (struct interp *interp)
{
return 1;
}
static struct gdb_exception
safe_execute_command (struct ui_out *command_uiout, char *command, int from_tty)
{
struct gdb_exception e = exception_none;
struct ui_out *saved_uiout;
/* Save and override the global ``struct ui_out'' builder. */
saved_uiout = current_uiout;
current_uiout = command_uiout;
TRY
{
execute_command (command, from_tty);
}
CATCH (exception, RETURN_MASK_ALL)
{
e = exception;
}
END_CATCH
/* Restore the global builder. */
current_uiout = saved_uiout;
/* FIXME: cagney/2005-01-13: This shouldn't be needed. Instead the
caller should print the exception. */
exception_print (gdb_stderr, e);
return e;
}
static struct ui_out *
cli_ui_out (struct interp *self)
{
struct cli_interp *cli = (struct cli_interp *) interp_data (self);
return cli->cli_uiout;
}
/* The CLI interpreter's vtable. */
static const struct interp_procs cli_interp_procs = {
cli_interpreter_init, /* init_proc */
cli_interpreter_resume, /* resume_proc */
cli_interpreter_suspend, /* suspend_proc */
cli_interpreter_exec, /* exec_proc */
cli_ui_out, /* ui_out_proc */
NULL, /* set_logging_proc */
cli_command_loop, /* command_loop_proc */
cli_interpreter_supports_command_editing, /* supports_command_editing_proc */
};
/* Factory for CLI interpreters. */
static struct interp *
cli_interp_factory (const char *name)
{
struct cli_interp *cli = XNEW (struct cli_interp);
/* Create a default uiout builder for the CLI. */
cli->cli_uiout = cli_out_new (gdb_stdout);
return interp_new (name, &cli_interp_procs, cli);
}
/* Standard gdb initialization hook. */
extern initialize_file_ftype _initialize_cli_interp; /* -Wmissing-prototypes */
void
_initialize_cli_interp (void)
{
interp_factory_register (INTERP_CONSOLE, cli_interp_factory);
/* If changing this, remember to update tui-interp.c as well. */
observer_attach_normal_stop (cli_on_normal_stop);
observer_attach_end_stepping_range (cli_on_end_stepping_range);
observer_attach_signal_received (cli_on_signal_received);
observer_attach_signal_exited (cli_on_signal_exited);
observer_attach_exited (cli_on_exited);
observer_attach_no_history (cli_on_no_history);
observer_attach_sync_execution_done (cli_on_sync_execution_done);
observer_attach_command_error (cli_on_command_error);
}