2
0
mirror of https://sourceware.org/git/binutils-gdb.git synced 2024-12-27 04:52:05 +08:00
binutils-gdb/gdb/interps.h
Pedro Alves 60eb5395fa Add new command to create extra console/mi UIs
With all the previous plumbing in place, it's now easy to add a
command that actually creates a new console/mi UI.

The intended use case is to make it possible and easy for MI frontends
to provide a fully featured GDB console to users, with readline
support, command line editing, history, etc., just like if gdb was
started on the command line.  Currently MI frontends have to try to
implement all of that theirselves and make use of "-interpreter-exec
console ...", which is far from perfect.  If you ever tried Eclipse's
gdb console window, you'll know what I mean...

Instead of trying to multiplex console through MI, this command let's
just leverage all the built in readline/editing support already inside
gdb.

The plan is for the MI frontend to start GDB in regular console mode,
running inside a terminal emulator widget embedded in Eclipse (which
already exists, for supporting the shell widget; other frontends have
similar widgets), and then tell GDB to run a full MI interpreter on an
specified input/output device, independent of the console.

My original prototype planned to do things the other way around --
start GDB in MI mode, and then start an extra CLI console on separate
tty.  I handed over that prototype to Marc Khouzam @ Eclipse CDT, and
after experimentation and discussion, we ended up concluding that
starting GDB in CLI mode instead was both easier and actually also
supported an interesting use case -- connect an Eclipse frontend to a
GDB that is already running outside Eclipse.

The current usage is "new-ui <interpreter> <tty>".

E.g., on a terminal run this scriplet:

 $ cat gdb-client
 #!/bin/bash

 reset
 tty
 tail -f /dev/null

 $ gdb-client
 /dev/pts/15

Now run gdb on another terminal, and tell it to start a MI interpreter
on the tty of the other terminal:

 ...
 (gdb) new-ui mi /dev/pts/15
 New UI allocated

Now back to the the gdb-client terminal, we'll get an MI prompt, ready
for MI input:

 /dev/pts/15
 =thread-group-added,id="i1"
 (gdb)

You can also start a new UI running a CLI, with:

 (gdb) new-ui console /dev/pts/15

Though note that this console won't support readline command editing.
It works as if "set editing off" was entered.

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

	* interps.c (set_top_level_interpreter): New function, factored
	out from captured_main.
	(interpreter_completer): Make extern.
	* interps.h (set_top_level_interpreter, interpreter_completer):
	New declarations.
	(captured_main): Use set_top_level_interpreter.
	* top.c [!O_NOCTTY] (O_NOCTTY): Define as 0.
	(open_terminal_stream, new_ui_command): New functions.
	(init_main): Install the "new-ui" command.
2016-06-21 01:11:55 +01:00

155 lines
5.8 KiB
C

/* Manages interpreters for GDB, the GNU debugger.
Copyright (C) 2000-2016 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/>. */
#ifndef INTERPS_H
#define INTERPS_H
struct ui_out;
struct interp;
struct ui;
typedef struct interp *(*interp_factory_func) (const char *name);
/* Each interpreter kind (CLI, MI, etc.) registers itself with a call
to this function, passing along its name, and a pointer to a
function that creates a new instance of an interpreter with that
name. */
extern void interp_factory_register (const char *name,
interp_factory_func func);
extern int interp_resume (struct interp *interp);
extern int interp_suspend (struct interp *interp);
extern struct gdb_exception interp_exec (struct interp *interp,
const char *command);
extern int interp_quiet_p (struct interp *interp);
typedef void *(interp_init_ftype) (struct interp *self, int top_level);
typedef int (interp_resume_ftype) (void *data);
typedef int (interp_suspend_ftype) (void *data);
typedef struct gdb_exception (interp_exec_ftype) (void *data,
const char *command);
typedef void (interp_pre_command_loop_ftype) (struct interp *self);
typedef struct ui_out *(interp_ui_out_ftype) (struct interp *self);
typedef int (interp_set_logging_ftype) (struct interp *self, int start_log,
struct ui_file *out,
struct ui_file *logfile);
typedef int (interp_supports_command_editing_ftype) (struct interp *self);
struct interp_procs
{
interp_init_ftype *init_proc;
interp_resume_ftype *resume_proc;
interp_suspend_ftype *suspend_proc;
interp_exec_ftype *exec_proc;
/* Returns the ui_out currently used to collect results for this
interpreter. It can be a formatter for stdout, as is the case
for the console & mi outputs, or it might be a result
formatter. */
interp_ui_out_ftype *ui_out_proc;
/* Provides a hook for interpreters to do any additional
setup/cleanup that they might need when logging is enabled or
disabled. */
interp_set_logging_ftype *set_logging_proc;
/* Called before starting an event loop, to give the interpreter a
chance to e.g., print a prompt. */
interp_pre_command_loop_ftype *pre_command_loop_proc;
/* Returns true if this interpreter supports using the readline
library; false if it uses GDB's own simplified readline
emulation. */
interp_supports_command_editing_ftype *supports_command_editing_proc;
};
extern struct interp *interp_new (const char *name,
const struct interp_procs *procs,
void *data);
extern void interp_add (struct ui *ui, struct interp *interp);
extern int interp_set (struct interp *interp, int top_level);
/* Look up the interpreter for NAME, creating one if none exists yet.
If NAME is not a interpreter type previously registered with
interp_factory_register, return NULL; otherwise return a pointer to
the interpreter. */
extern struct interp *interp_lookup (struct ui *ui, const char *name);
/* Set the current UI's top level interpreter to the interpreter named
NAME. Throws an error if NAME is not a known interpreter or the
interpreter fails to initialize. */
extern void set_top_level_interpreter (const char *name);
extern struct ui_out *interp_ui_out (struct interp *interp);
extern void *interp_data (struct interp *interp);
extern const char *interp_name (struct interp *interp);
extern struct interp *interp_set_temp (const char *name);
extern int current_interp_named_p (const char *name);
/* Call this function to give the current interpreter an opportunity
to do any special handling of streams when logging is enabled or
disabled. START_LOG is 1 when logging is starting, 0 when it ends,
and OUT is the stream for the log file; it will be NULL when
logging is ending. LOGFILE is non-NULL if the output streams
are to be tees, with the log file as one of the outputs. */
extern int current_interp_set_logging (int start_log, struct ui_file *out,
struct ui_file *logfile);
/* Returns opaque data associated with the top-level interpreter. */
extern void *top_level_interpreter_data (void);
extern struct interp *top_level_interpreter (void);
/* Return the current UI's current interpreter. */
extern struct interp *current_interpreter (void);
extern struct interp *command_interp (void);
extern void clear_interpreter_hooks (void);
/* Returns true if INTERP supports using the readline library; false
if it uses GDB's own simplified form of readline. */
extern int interp_supports_command_editing (struct interp *interp);
/* Called before starting an event loop, to give the interpreter a
chance to e.g., print a prompt. */
extern void interp_pre_command_loop (struct interp *interp);
/* List the possible interpreters which could complete the given
text. */
extern VEC (char_ptr) *interpreter_completer (struct cmd_list_element *ignore,
const char *text,
const char *word);
/* well-known interpreters */
#define INTERP_CONSOLE "console"
#define INTERP_MI1 "mi1"
#define INTERP_MI2 "mi2"
#define INTERP_MI3 "mi3"
#define INTERP_MI "mi"
#define INTERP_TUI "tui"
#define INTERP_INSIGHT "insight"
#endif