darling-gdb/gdb/interps.c
Pedro Alves 92bcb5f949 Make display_gdb_prompt CLI-only.
Enabling target-async by default will require implementing sync
execution on top of an async target, much like foreground command are
implemented on the CLI in async mode.

In order to do that, we will need better control of when to print the
MI prompt.  Currently the interp->display_prompt_p hook is all we
have, and MI just always returns false, meaning, make
display_gdb_prompt a no-op.  We'll need to be able to know to print
the MI prompt in some of the conditions that display_gdb_prompt is
called from the core, but not all.

This is all a litte twisted currently.  As we can see,
display_gdb_prompt is really CLI specific, so make the console
interpreters (console/tui) themselves call it.  To be able to do that,
and add a few different observers that the interpreters can use to
distinguish when or why the the prompt is being printed:

#1 - one called whenever a command is cancelled due to an error.
#2 - another for when a foreground command just finished.

In both cases, CLI wants to print the prompt, while MI doesn't.

MI will want to print the prompt in the second case when in a special
MI mode.

The display_gdb_prompt call in interp_set made me pause.  The comment
there reads:

  /* Finally, put up the new prompt to show that we are indeed here.
     Also, display_gdb_prompt for the console does some readline magic
     which is needed for the console interpreter, at least...  */

But, that looks very much like a no-op to me currently:

 - the MI interpreter always return false in the prompt hook, meaning
   actually display no prompt.

 - the interpreter used at that point is still quiet.  And the
   console/tui interpreters return false in the prompt hook if they're
   quiet, meaning actually display no prompt.

The only remaining possible use would then be the readline magic.  But
whatever that might have been, it's not reacheable today either,
because display_gdb_prompt returns early, before touching readline if
the interpreter returns false in the display_prompt_p hook.

Tested on x86_64 Fedora 20, sync and async modes.

gdb/
2014-05-29  Pedro Alves  <palves@redhat.com>

	* cli/cli-interp.c (cli_interpreter_display_prompt_p): Delete.
	(_initialize_cli_interp): Adjust.
	* event-loop.c: Include "observer.h".
	(start_event_loop): Notify 'command_error' observers instead of
	calling display_gdb_prompt.  Remove FIXME comment.
	* event-top.c (display_gdb_prompt): Remove call into the
	interpreters.
	* inf-loop.c: Include "observer.h".
	(inferior_event_handler): Notify 'command_error' observers instead
	of calling display_gdb_prompt.
	* infrun.c (fetch_inferior_event): Notify 'sync_execution_done'
	observers instead of calling display_gdb_prompt.
	* interps.c (interp_set): Don't call display_gdb_prompt.
	(current_interp_display_prompt_p): Delete.
	* interps.h (interp_prompt_p): Delete declaration.
	(interp_prompt_p_ftype): Delete.
	(struct interp_procs) <prompt_proc_p>: Delete field.
	(current_interp_display_prompt_p): Delete declaration.
	* mi-interp.c (mi_interpreter_prompt_p): Delete.
	(_initialize_mi_interp): Adjust.
	* tui-interp.c (tui_init): Install 'sync_execution_done' and
	'command_error' observers.
	(tui_on_sync_execution_done, tui_on_command_error): New
	functions.
	(tui_display_prompt_p): Delete.
	(_initialize_tui_interp): Adjust.

gdb/doc/
2014-05-29  Pedro Alves  <palves@redhat.com>

	* observer.texi (sync_execution_done, command_error): New
	subjects.
2014-05-29 13:47:09 +01:00

524 lines
14 KiB
C

/* Manages interpreters for GDB, the GNU debugger.
Copyright (C) 2000-2014 Free Software Foundation, Inc.
Written by Jim Ingham <jingham@apple.com> of Apple Computer, 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/>. */
/* This is just a first cut at separating out the "interpreter"
functions of gdb into self-contained modules. There are a couple
of open areas that need to be sorted out:
1) The interpreter explicitly contains a UI_OUT, and can insert itself
into the event loop, but it doesn't explicitly contain hooks for readline.
I did this because it seems to me many interpreters won't want to use
the readline command interface, and it is probably simpler to just let
them take over the input in their resume proc. */
#include "defs.h"
#include "gdbcmd.h"
#include "ui-out.h"
#include "event-loop.h"
#include "event-top.h"
#include "interps.h"
#include "completer.h"
#include <string.h>
#include "gdb_assert.h"
#include "top.h" /* For command_loop. */
#include "exceptions.h"
#include "continuations.h"
/* True if the current interpreter in is async mode. See interps.h
for more details. This starts out disabled, until all the explicit
command line arguments (e.g., `gdb -ex "start" -ex "next"') are
processed. */
int interpreter_async = 0;
struct interp
{
/* This is the name in "-i=" and set interpreter. */
const char *name;
/* Interpreters are stored in a linked list, this is the next
one... */
struct interp *next;
/* This is a cookie that an instance of the interpreter can use.
This is a bit confused right now as the exact initialization
sequence for it, and how it relates to the interpreter's uiout
object is a bit confused. */
void *data;
/* Has the init_proc been run? */
int inited;
const struct interp_procs *procs;
int quiet_p;
};
/* Functions local to this file. */
static void initialize_interps (void);
/* The magic initialization routine for this module. */
void _initialize_interpreter (void);
/* Variables local to this file: */
static struct interp *interp_list = NULL;
static struct interp *current_interpreter = NULL;
static struct interp *top_level_interpreter_ptr = NULL;
static int interpreter_initialized = 0;
/* interp_new - This allocates space for a new interpreter,
fills the fields from the inputs, and returns a pointer to the
interpreter. */
struct interp *
interp_new (const char *name, const struct interp_procs *procs)
{
struct interp *new_interp;
new_interp = XNEW (struct interp);
new_interp->name = xstrdup (name);
new_interp->data = NULL;
new_interp->quiet_p = 0;
new_interp->procs = procs;
new_interp->inited = 0;
/* Check for required procs. */
gdb_assert (procs->command_loop_proc != NULL);
return new_interp;
}
/* Add interpreter INTERP to the gdb interpreter list. The
interpreter must not have previously been added. */
void
interp_add (struct interp *interp)
{
if (!interpreter_initialized)
initialize_interps ();
gdb_assert (interp_lookup (interp->name) == NULL);
interp->next = interp_list;
interp_list = interp;
}
/* This sets the current interpreter to be INTERP. If INTERP has not
been initialized, then this will also run the init proc. If the
init proc is successful, return 1, if it fails, set the old
interpreter back in place and return 0. If we can't restore the
old interpreter, then raise an internal error, since we are in
pretty bad shape at this point.
The TOP_LEVEL parameter tells if this new interpreter is
the top-level one. The top-level is what is requested
on the command line, and is responsible for reporting general
notification about target state changes. For example, if
MI is the top-level interpreter, then it will always report
events such as target stops and new thread creation, even if they
are caused by CLI commands. */
int
interp_set (struct interp *interp, int top_level)
{
struct interp *old_interp = current_interpreter;
int first_time = 0;
char buffer[64];
/* If we already have an interpreter, then trying to
set top level interpreter is kinda pointless. */
gdb_assert (!top_level || !current_interpreter);
gdb_assert (!top_level || !top_level_interpreter_ptr);
if (current_interpreter != NULL)
{
ui_out_flush (current_uiout);
if (current_interpreter->procs->suspend_proc
&& !current_interpreter->procs->suspend_proc (current_interpreter->
data))
{
error (_("Could not suspend interpreter \"%s\"."),
current_interpreter->name);
}
}
else
{
first_time = 1;
}
current_interpreter = interp;
if (top_level)
top_level_interpreter_ptr = interp;
/* We use interpreter_p for the "set interpreter" variable, so we need
to make sure we have a malloc'ed copy for the set command to free. */
if (interpreter_p != NULL
&& strcmp (current_interpreter->name, interpreter_p) != 0)
{
xfree (interpreter_p);
interpreter_p = xstrdup (current_interpreter->name);
}
/* Run the init proc. If it fails, try to restore the old interp. */
if (!interp->inited)
{
if (interp->procs->init_proc != NULL)
{
interp->data = interp->procs->init_proc (interp, top_level);
}
interp->inited = 1;
}
/* Do this only after the interpreter is initialized. */
current_uiout = interp->procs->ui_out_proc (interp);
/* Clear out any installed interpreter hooks/event handlers. */
clear_interpreter_hooks ();
if (interp->procs->resume_proc != NULL
&& (!interp->procs->resume_proc (interp->data)))
{
if (old_interp == NULL || !interp_set (old_interp, 0))
internal_error (__FILE__, __LINE__,
_("Failed to initialize new interp \"%s\" %s"),
interp->name, "and could not restore old interp!\n");
return 0;
}
if (!first_time && !interp_quiet_p (interp))
{
xsnprintf (buffer, sizeof (buffer),
"Switching to interpreter \"%.24s\".\n", interp->name);
ui_out_text (current_uiout, buffer);
}
return 1;
}
/* interp_lookup - Looks up the interpreter for NAME. If no such
interpreter exists, return NULL, otherwise return a pointer to the
interpreter. */
struct interp *
interp_lookup (const char *name)
{
struct interp *interp;
if (name == NULL || strlen (name) == 0)
return NULL;
for (interp = interp_list; interp != NULL; interp = interp->next)
{
if (strcmp (interp->name, name) == 0)
return interp;
}
return NULL;
}
/* Returns the current interpreter. */
struct ui_out *
interp_ui_out (struct interp *interp)
{
if (interp != NULL)
return interp->procs->ui_out_proc (interp);
return current_interpreter->procs->ui_out_proc (current_interpreter);
}
int
current_interp_set_logging (int start_log, struct ui_file *out,
struct ui_file *logfile)
{
if (current_interpreter == NULL
|| current_interpreter->procs->set_logging_proc == NULL)
return 0;
return current_interpreter->procs->set_logging_proc (current_interpreter,
start_log, out,
logfile);
}
/* Temporarily overrides the current interpreter. */
struct interp *
interp_set_temp (const char *name)
{
struct interp *interp = interp_lookup (name);
struct interp *old_interp = current_interpreter;
if (interp)
current_interpreter = interp;
return old_interp;
}
/* Returns the interpreter's cookie. */
void *
interp_data (struct interp *interp)
{
return interp->data;
}
/* Returns the interpreter's name. */
const char *
interp_name (struct interp *interp)
{
return interp->name;
}
/* Returns true if the current interp is the passed in name. */
int
current_interp_named_p (const char *interp_name)
{
if (current_interpreter)
return (strcmp (current_interpreter->name, interp_name) == 0);
return 0;
}
/* The interpreter that is active while `interp_exec' is active, NULL
at all other times. */
static struct interp *command_interpreter;
/* The interpreter that was active when a command was executed.
Normally that'd always be CURRENT_INTERPRETER, except that MI's
-interpreter-exec command doesn't actually flip the current
interpreter when running its sub-command. The
`command_interpreter' global tracks when interp_exec is called
(IOW, when -interpreter-exec is called). If that is set, it is
INTERP in '-interpreter-exec INTERP "CMD"' or in 'interpreter-exec
INTERP "CMD". Otherwise, interp_exec isn't active, and so the
interpreter running the command is the current interpreter. */
struct interp *
command_interp (void)
{
if (command_interpreter != NULL)
return command_interpreter;
else
return current_interpreter;
}
/* Run the current command interpreter's main loop. */
void
current_interp_command_loop (void)
{
gdb_assert (current_interpreter != NULL);
current_interpreter->procs->command_loop_proc (current_interpreter->data);
}
int
interp_quiet_p (struct interp *interp)
{
if (interp != NULL)
return interp->quiet_p;
else
return current_interpreter->quiet_p;
}
static int
interp_set_quiet (struct interp *interp, int quiet)
{
int old_val = interp->quiet_p;
interp->quiet_p = quiet;
return old_val;
}
/* interp_exec - This executes COMMAND_STR in the current
interpreter. */
struct gdb_exception
interp_exec (struct interp *interp, const char *command_str)
{
struct gdb_exception ex;
struct interp *save_command_interp;
gdb_assert (interp->procs->exec_proc != NULL);
/* See `command_interp' for why we do this. */
save_command_interp = command_interpreter;
command_interpreter = interp;
ex = interp->procs->exec_proc (interp->data, command_str);
command_interpreter = save_command_interp;
return ex;
}
/* A convenience routine that nulls out all the common command hooks.
Use it when removing your interpreter in its suspend proc. */
void
clear_interpreter_hooks (void)
{
deprecated_init_ui_hook = 0;
deprecated_print_frame_info_listing_hook = 0;
/*print_frame_more_info_hook = 0; */
deprecated_query_hook = 0;
deprecated_warning_hook = 0;
deprecated_interactive_hook = 0;
deprecated_readline_begin_hook = 0;
deprecated_readline_hook = 0;
deprecated_readline_end_hook = 0;
deprecated_register_changed_hook = 0;
deprecated_context_hook = 0;
deprecated_target_wait_hook = 0;
deprecated_call_command_hook = 0;
deprecated_error_begin_hook = 0;
}
/* This is a lazy init routine, called the first time the interpreter
module is used. I put it here just in case, but I haven't thought
of a use for it yet. I will probably bag it soon, since I don't
think it will be necessary. */
static void
initialize_interps (void)
{
interpreter_initialized = 1;
/* Don't know if anything needs to be done here... */
}
static void
interpreter_exec_cmd (char *args, int from_tty)
{
struct interp *old_interp, *interp_to_use;
char **prules = NULL;
char **trule = NULL;
unsigned int nrules;
unsigned int i;
int old_quiet, use_quiet;
struct cleanup *cleanup;
if (args == NULL)
error_no_arg (_("interpreter-exec command"));
prules = gdb_buildargv (args);
cleanup = make_cleanup_freeargv (prules);
nrules = 0;
for (trule = prules; *trule != NULL; trule++)
nrules++;
if (nrules < 2)
error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
old_interp = current_interpreter;
interp_to_use = interp_lookup (prules[0]);
if (interp_to_use == NULL)
error (_("Could not find interpreter \"%s\"."), prules[0]);
/* Temporarily set interpreters quiet. */
old_quiet = interp_set_quiet (old_interp, 1);
use_quiet = interp_set_quiet (interp_to_use, 1);
if (!interp_set (interp_to_use, 0))
error (_("Could not switch to interpreter \"%s\"."), prules[0]);
for (i = 1; i < nrules; i++)
{
struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
if (e.reason < 0)
{
interp_set (old_interp, 0);
interp_set_quiet (interp_to_use, use_quiet);
interp_set_quiet (old_interp, old_quiet);
error (_("error in command: \"%s\"."), prules[i]);
}
}
interp_set (old_interp, 0);
interp_set_quiet (interp_to_use, use_quiet);
interp_set_quiet (old_interp, old_quiet);
do_cleanups (cleanup);
}
/* List the possible interpreters which could complete the given text. */
static VEC (char_ptr) *
interpreter_completer (struct cmd_list_element *ignore,
const char *text, const char *word)
{
int textlen;
VEC (char_ptr) *matches = NULL;
struct interp *interp;
textlen = strlen (text);
for (interp = interp_list; interp != NULL; interp = interp->next)
{
if (strncmp (interp->name, text, textlen) == 0)
{
char *match;
match = (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
if (word == text)
strcpy (match, interp->name);
else if (word > text)
{
/* Return some portion of interp->name. */
strcpy (match, interp->name + (word - text));
}
else
{
/* Return some of text plus interp->name. */
strncpy (match, word, text - word);
match[text - word] = '\0';
strcat (match, interp->name);
}
VEC_safe_push (char_ptr, matches, match);
}
}
return matches;
}
struct interp *
top_level_interpreter (void)
{
return top_level_interpreter_ptr;
}
void *
top_level_interpreter_data (void)
{
gdb_assert (top_level_interpreter_ptr);
return top_level_interpreter_ptr->data;
}
/* This just adds the "interpreter-exec" command. */
void
_initialize_interpreter (void)
{
struct cmd_list_element *c;
c = add_cmd ("interpreter-exec", class_support,
interpreter_exec_cmd, _("\
Execute a command in an interpreter. It takes two arguments:\n\
The first argument is the name of the interpreter to use.\n\
The second argument is the command to execute.\n"), &cmdlist);
set_cmd_completer (c, interpreter_completer);
}