old-cross-binutils/gdb/tui/tui.h
Pedro Alves 84eda397bc PR tui/16138, PR tui/17519, and misc failures to initialize the terminal
PR tui/16138 is about failure to initialize curses resulting in GDB
exiting instead of throwing an error.  E.g.:

 $ TERM=foo gdb
 (gdb) layout asm
 Error opening terminal: foo.
 $

The problem is that we're calling initscr to initialize the screen.
As mentioned in
http://pubs.opengroup.org/onlinepubs/7908799/xcurses/initscr.html:

 If errors occur, initscr() writes an appropriate error message to
 standard error and exits.
                    ^^^^^

Instead, we should use newterm:

 "A program that needs an indication of error conditions, so it can
 continue to run in a line-oriented mode if the terminal cannot support
 a screen-oriented program, would also use this function."

After the patch:

 $ TERM=foo gdb -q -nx
 (gdb) layout asm
 Cannot enable the TUI: error opening terminal [TERM=foo]
 (gdb)

And then PR tui/17519 is about GDB not validating whether the terminal
has the necessary capabilities when enabling the TUI.  If one tries to
enable the TUI with TERM=dumb (and e.g., from a shell within emacs),
GDB ends up with a clear screen, the cursor is placed at the
bottom/right corner of the screen, there's no prompt, typing shows no
echo, and there's no indication of what's going on.  c-x,a gets you
out of the TUI, but it's completely non-obvious.

After the patch, we get:

 $ TERM=dumb gdb -q -nx
 (gdb) layout asm
 Cannot enable the TUI: terminal doesn't support cursor addressing [TERM=dumb]
 (gdb)

While at it, I've moved all the tui_allowed_p validation to
tui_enable, and expanded the error messages.  Previously we'd get:

 $ gdb -q -nx -i=mi
 (gdb)
 layout asm
 &"layout asm\n"
 &"TUI mode not allowed\n"
 ^error,msg="TUI mode not allowed"

and:

 $ gdb -q -nx -ex "layout asm" > foo
 TUI mode not allowed

While now we get:

 $ gdb -q -nx -i=mi
 (gdb)
 layout asm
 &"layout asm\n"
 &"Cannot enable the TUI when the interpreter is 'mi'\n"
 ^error,msg="Cannot enable the TUI when the interpreter is 'mi'"
 (gdb)

and:

 $ gdb -q -nx -ex "layout asm" > foo
 Cannot enable the TUI when output is not a terminal

Tested on x86_64 Fedora 20.

gdb/
2014-10-29  Pedro Alves  <palves@redhat.com>

	PR tui/16138
	PR tui/17519
	* tui/tui-interp.c (tui_is_toplevel): Delete global.
	(tui_allowed_p): Delete function.
	* tui/tui.c: Include "interps.h".
	(tui_enable): Don't use tui_allowed_p.  Error out here with
	detailed error messages if the TUI is the top level interpreter,
	or if output is not a terminal.  Use newterm instead of initscr,
	and error out if initializing the terminal fails.  Also error out if
	the terminal doesn't support cursor addressing.
	* tui/tui.h (tui_allowed_p): Delete declaration.
2014-10-29 14:23:57 +00:00

101 lines
2.6 KiB
C

/* External/Public TUI Header File.
Copyright (C) 1998-2014 Free Software Foundation, Inc.
Contributed by Hewlett-Packard Company.
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 TUI_H
#define TUI_H
struct ui_file;
extern void strcat_to_buf (char *, int, const char *);
/* Types of error returns. */
enum tui_status
{
TUI_SUCCESS,
TUI_FAILURE
};
/* Types of windows. */
enum tui_win_type
{
SRC_WIN = 0,
DISASSEM_WIN,
DATA_WIN,
CMD_WIN,
/* This must ALWAYS be AFTER the major windows last. */
MAX_MAJOR_WINDOWS,
/* Auxillary windows. */
LOCATOR_WIN,
EXEC_INFO_WIN,
DATA_ITEM_WIN,
/* This must ALWAYS be next to last. */
MAX_WINDOWS,
UNDEFINED_WIN /* LAST */
};
/* GENERAL TUI FUNCTIONS */
/* tui.c */
extern CORE_ADDR tui_get_low_disassembly_address (struct gdbarch *,
CORE_ADDR, CORE_ADDR);
extern void tui_show_assembly (struct gdbarch *gdbarch, CORE_ADDR addr);
extern int tui_is_window_visible (enum tui_win_type type);
extern int tui_get_command_dimension (unsigned int *width,
unsigned int *height);
/* Initialize readline and configure the keymap for the switching
key shortcut. */
extern void tui_initialize_readline (void);
/* Enter in the tui mode (curses). */
extern void tui_enable (void);
/* Leave the tui mode. */
extern void tui_disable (void);
enum tui_key_mode
{
/* Plain command mode to enter gdb commands. */
TUI_COMMAND_MODE,
/* SingleKey mode with some keys bound to gdb commands. */
TUI_SINGLE_KEY_MODE,
/* Read/edit one command and return to SingleKey after it's
processed. */
TUI_ONE_COMMAND_MODE
};
extern enum tui_key_mode tui_current_key_mode;
/* Change the TUI key mode by installing the appropriate readline
keymap. */
extern void tui_set_key_mode (enum tui_key_mode mode);
extern int tui_active;
extern void tui_show_source (const char *fullname, int line);
extern struct ui_out *tui_out_new (struct ui_file *stream);
/* tui-layout.c */
extern enum tui_status tui_set_layout_for_display_command (const char *);
#endif