binutils-gdb/gdb/terminal.h
Patrick Palka 6a06d66006 Don't propagate our current terminal state to the inferior
Currently when we start an inferior we have the inferior inherit our
terminal state.  Under TUI, our terminal is highly modified by ncurses
and readline.  So when starting an inferior under TUI, the inferior will
have a highly modified terminal state which will interfere with standard
I/O. For example,

$ gdb gdb
(gdb) break main
(gdb) run
(gdb) print puts ("a\nb")
a
b
$1 = 4
(gdb) [enter TUI mode]
(gdb) run
(gdb) [exit TUI mode]
(gdb) print puts ("a\nb")
a
 b
  $2 = 4
(gdb) print puts ("a\r\nb\r")
a
b
$3 = 6

As you can see, when we start the inferior under the regular interface,
puts() prints the text properly.  But when we start the inferior under
TUI, puts() does not print the text properly.  This is because when we
start the inferior under TUI it inherits our current terminal state
which has been modified by ncurses to, among other things, require an
explicit \r\n to print a new line. As a result the inferior performs
standard I/O in an unexpected way.

Because of this discrepancy, it doesn't seem like a good idea to have
the inferior inherit our _current_ terminal state for it may have been
modified by readline and/or ncurses.  Instead, we should have the
inferior inherit a pristine snapshot of our terminal state taken before
readline or ncurses have had a chance to alter it.  This enables the
inferior to run in a more accurate way, more closely mimicking the
program's behavior had it run standalone.  And it fixes the above
mentioned issue.

Tested on x86_64-unknown-linux-gnu.

gdb/ChangeLog:

	* terminal.h (set_initial_gdb_ttystate): Declare.
	* inflow.c (initial_gdb_ttystate): New static variable.
	(set_initial_gdb_ttystate): New setter.
	(child_terminal_init_with_pgrp): Copy initial_gdb_ttystate
	instead of our current terminal state.
	* top.c (gdb_init): Call set_initial_gdb_ttystate.
2015-01-07 09:02:07 -05:00

113 lines
3.3 KiB
C

/* Terminal interface definitions for GDB, the GNU Debugger.
Copyright (C) 1986-2015 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/>. */
#if !defined (TERMINAL_H)
#define TERMINAL_H 1
/* If we're using autoconf, it will define HAVE_TERMIOS_H,
HAVE_TERMIO_H and HAVE_SGTTY_H for us. One day we can rewrite
ser-unix.c and inflow.c to inspect those names instead of
HAVE_TERMIOS, HAVE_TERMIO and the implicit HAVE_SGTTY (when neither
HAVE_TERMIOS or HAVE_TERMIO is set). Until then, make sure that
nothing has already defined the one of the names, and do the right
thing. */
#if !defined (HAVE_TERMIOS) && !defined(HAVE_TERMIO) && !defined(HAVE_SGTTY)
#if defined(HAVE_TERMIOS_H)
#define HAVE_TERMIOS
#else /* ! defined (HAVE_TERMIOS_H) */
#if defined(HAVE_TERMIO_H)
#define HAVE_TERMIO
#else /* ! defined (HAVE_TERMIO_H) */
#if defined(HAVE_SGTTY_H)
#define HAVE_SGTTY
#endif /* ! defined (HAVE_SGTTY_H) */
#endif /* ! defined (HAVE_TERMIO_H) */
#endif /* ! defined (HAVE_TERMIOS_H) */
#endif /* !defined (HAVE_TERMIOS) && !defined (HAVE_TERMIO) &&
!defined (HAVE_SGTTY) */
#if defined(HAVE_TERMIOS)
#include <termios.h>
#endif
#if !defined(_WIN32) && !defined (HAVE_TERMIOS)
/* Define a common set of macros -- BSD based -- and redefine whatever
the system offers to make it look like that. FIXME: serial.h and
ser-*.c deal with this in a much cleaner fashion; as soon as stuff
is converted to use them, can get rid of this crap. */
#ifdef HAVE_TERMIO
#include <termio.h>
#undef TIOCGETP
#define TIOCGETP TCGETA
#undef TIOCSETN
#define TIOCSETN TCSETA
#undef TIOCSETP
#define TIOCSETP TCSETAF
#define TERMINAL struct termio
#else /* sgtty */
#include <fcntl.h>
#include <sgtty.h>
#include <sys/ioctl.h>
#define TERMINAL struct sgttyb
#endif /* sgtty */
#endif
struct inferior;
extern void new_tty_prefork (const char *);
extern void new_tty (void);
extern void new_tty_postfork (void);
extern void copy_terminal_info (struct inferior *to, struct inferior *from);
/* Do we have job control? Can be assumed to always be the same within
a given run of GDB. In inflow.c. */
extern int job_control;
extern pid_t create_tty_session (void);
/* Set the process group of the caller to its own pid, or do nothing if
we lack job control. */
extern int gdb_setpgid (void);
/* Set up a serial structure describing standard input. In inflow.c. */
extern void initialize_stdin_serial (void);
extern int gdb_has_a_terminal (void);
extern void gdb_save_tty_state (void);
extern void set_initial_gdb_ttystate (void);
/* Set the process group of the caller to its own pid, or do nothing
if we lack job control. */
extern int gdb_setpgid (void);
#endif /* !defined (TERMINAL_H) */