/* TUI support I/O functions.
Copyright (C) 1998-2020 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/>. */
#include "defs.h"
#include "target.h"
#include "gdbsupport/event-loop.h"
#include "event-top.h"
#include "command.h"
#include "top.h"
#include "tui/tui.h"
#include "tui/tui-data.h"
#include "tui/tui-io.h"
#include "tui/tui-command.h"
#include "tui/tui-win.h"
#include "tui/tui-wingeneral.h"
#include "tui/tui-file.h"
#include "tui/tui-out.h"
#include "ui-out.h"
#include "cli-out.h"
#include <fcntl.h>
#include <signal.h>
#ifdef __MINGW32__
#include <windows.h>
#endif
#include "gdbsupport/filestuff.h"
#include "completer.h"
#include "gdb_curses.h"
#include <map>
/* This redefines CTRL if it is not already defined, so it must come
after terminal state releated include files like <term.h> and
"gdb_curses.h". */
#include "readline/readline.h"
#ifdef __MINGW32__
static SHORT ncurses_norm_attr;
#endif
static int tui_getc (FILE *fp);
static int
key_is_start_sequence (int ch)
{
return (ch == 27);
}
/* Use definition from readline 4.3. */
#undef CTRL_CHAR
#define CTRL_CHAR(c) \
((c) < control_character_threshold && (((c) & 0x80) == 0))
/* This file controls the IO interactions between gdb and curses.
When the TUI is enabled, gdb has two modes a curses and a standard
mode.
In curses mode, the gdb outputs are made in a curses command
window. For this, the gdb_stdout and gdb_stderr are redirected to
the specific ui_file implemented by TUI. The output is handled by
tui_puts(). The input is also controlled by curses with
tui_getc(). The readline library uses this function to get its
input. Several readline hooks are installed to redirect readline
output to the TUI (see also the note below).
In normal mode, the gdb outputs are restored to their origin, that
is as if TUI is not used. Readline also uses its original getc()
function with stdin.
Note SCz/2001-07-21: the current readline is not clean in its
management of the output. Even if we install a redisplay handler,
it sometimes writes on a stdout file. It is important to redirect
every output produced by readline, otherwise the curses window will
be garbled. This is implemented with a pipe that TUI reads and
readline writes to. A gdb input handler is created so that reading
the pipe is handled automatically. This will probably not work on
non-Unix platforms. The best fix is to make readline clean enough
so that is never write on stdout.
Note SCz/2002-09-01: we now use more readline hooks and it seems
that with them we don't need the pipe anymore (verified by creating
the pipe and closing its end so that write causes a SIGPIPE). The
old pipe code is still there and can be conditionally removed by
#undef TUI_USE_PIPE_FOR_READLINE. */
/* For gdb 5.3, prefer to continue the pipe hack as a backup wheel. */
#ifdef HAVE_PIPE
#define TUI_USE_PIPE_FOR_READLINE
#endif
/* #undef TUI_USE_PIPE_FOR_READLINE */
/* TUI output files. */
static struct ui_file *tui_stdout;
static struct ui_file *tui_stderr;
struct ui_out *tui_out;
/* GDB output files in non-curses mode. */
static struct ui_file *tui_old_stdout;
static struct ui_file *tui_old_stderr;
cli_ui_out *tui_old_uiout;
/* Readline previous hooks. */
static rl_getc_func_t *tui_old_rl_getc_function;
static rl_voidfunc_t *tui_old_rl_redisplay_function;
static rl_vintfunc_t *tui_old_rl_prep_terminal;
static rl_voidfunc_t *tui_old_rl_deprep_terminal;
static rl_compdisp_func_t *tui_old_rl_display_matches_hook;
static int tui_old_rl_echoing_p;
/* Readline output stream.
Should be removed when readline is clean. */
static FILE *tui_rl_outstream;
static FILE *tui_old_rl_outstream;
#ifdef TUI_USE_PIPE_FOR_READLINE
static int tui_readline_pipe[2];
#endif
/* Print a character in the curses command window. The output is
buffered. It is up to the caller to refresh the screen if
necessary. */
static void
do_tui_putc (WINDOW *w, char c)
{
/* Expand TABs, since ncurses on MS-Windows doesn't. */
if (c == '\t')
{
int col;
col = getcurx (w);
do
{
waddch (w, ' ');
col++;
}
while ((col % 8) != 0);
}
else
waddch (w, c);
}
/* Update the cached value of the command window's start line based on
the window's current Y coordinate. */
static void
update_cmdwin_start_line ()
{
TUI_CMD_WIN->start_line = getcury (TUI_CMD_WIN->handle.get ());
}
/* Print a character in the curses command window. The output is
buffered. It is up to the caller to refresh the screen if
necessary. */
static void
tui_putc (char c)
{
do_tui_putc (TUI_CMD_WIN->handle.get (), c);
update_cmdwin_start_line ();
}
/* This maps colors to their corresponding color index. */
static std::map<ui_file_style::color, int> color_map;
/* This holds a pair of colors and is used to track the mapping
between a color pair index and the actual colors. */
struct color_pair
{
int fg;
int bg;
bool operator< (const color_pair &o) const
{
return fg < o.fg || (fg == o.fg && bg < o.bg);
}
};
/* This maps pairs of colors to their corresponding color pair
index. */
static std::map<color_pair, int> color_pair_map;
/* This is indexed by ANSI color offset from the base color, and holds
the corresponding curses color constant. */
static const int curses_colors[] = {
COLOR_BLACK,
COLOR_RED,
COLOR_GREEN,
COLOR_YELLOW,
COLOR_BLUE,
COLOR_MAGENTA,
COLOR_CYAN,
COLOR_WHITE
};
/* Given a color, find its index. */
static bool
get_color (const ui_file_style::color &color, int *result)
{
if (color.is_none ())
*result = -1;
else if (color.is_basic ())
*result = curses_colors[color.get_value ()];
else
{
auto it = color_map.find (color);
if (it == color_map.end ())
{
/* The first 8 colors are standard. */
int next = color_map.size () + 8;
if (next >= COLORS)
return false;
uint8_t rgb[3];
color.get_rgb (rgb);
/* We store RGB as 0..255, but curses wants 0..1000. */
if (init_color (next, rgb[0] * 1000 / 255, rgb[1] * 1000 / 255,
rgb[2] * 1000 / 255) == ERR)
return false;
color_map[color] = next;
*result = next;
}
else
*result = it->second;
}
return true;
}
/* The most recently emitted color pair. */
static int last_color_pair = -1;
/* The most recently applied style. */
static ui_file_style last_style;
/* If true, we're highlighting the current source line in reverse
video mode. */
static bool reverse_mode_p = false;
/* The background/foreground colors before we entered reverse
mode. */
static ui_file_style::color reverse_save_bg (ui_file_style::NONE);
static ui_file_style::color reverse_save_fg (ui_file_style::NONE);
/* Given two colors, return their color pair index; making a new one
if necessary. */
static int
get_color_pair (int fg, int bg)
{
color_pair c = { fg, bg };
auto it = color_pair_map.find (c);
if (it == color_pair_map.end ())
{
/* Color pair 0 is our default color, so new colors start at
1. */
int next = color_pair_map.size () + 1;
/* Curses has a limited number of available color pairs. Fall
back to the default if we've used too many. */
if (next >= COLOR_PAIRS)
return 0;
init_pair (next, fg, bg);
color_pair_map[c] = next;
return next;
}
return it->second;
}
/* Apply STYLE to W. */
void
tui_apply_style (WINDOW *w, ui_file_style style)
{
/* Reset. */
wattron (w, A_NORMAL);
wattroff (w, A_BOLD);
wattroff (w, A_DIM);
wattroff (w, A_REVERSE);
if (last_color_pair != -1)
wattroff (w, COLOR_PAIR (last_color_pair));
wattron (w, COLOR_PAIR (0));
const ui_file_style::color &fg = style.get_foreground ();
const ui_file_style::color &bg = style.get_background ();
if (!fg.is_none () || !bg.is_none ())
{
int fgi, bgi;
if (get_color (fg, &fgi) && get_color (bg, &bgi))
{
#ifdef __MINGW32__
/* MS-Windows port of ncurses doesn't support implicit
default foreground and background colors, so we must
specify them explicitly when needed, using the colors we
saw at startup. */
if (fgi == -1)
fgi = ncurses_norm_attr & 15;
if (bgi == -1)
bgi = (ncurses_norm_attr >> 4) & 15;
#endif
int pair = get_color_pair (fgi, bgi);
if (last_color_pair != -1)
wattroff (w, COLOR_PAIR (last_color_pair));
wattron (w, COLOR_PAIR (pair));
last_color_pair = pair;
}
}
switch (style.get_intensity ())
{
case ui_file_style::NORMAL:
break;
case ui_file_style::BOLD:
wattron (w, A_BOLD);
break;
case ui_file_style::DIM:
wattron (w, A_DIM);
break;
default:
gdb_assert_not_reached ("invalid intensity");
}
if (style.is_reverse ())
wattron (w, A_REVERSE);
last_style = style;
}
/* Apply an ANSI escape sequence from BUF to W. BUF must start with
the ESC character. If BUF does not start with an ANSI escape,
return 0. Otherwise, apply the sequence if it is recognized, or
simply ignore it if not. In this case, the number of bytes read
from BUF is returned. */
static size_t
apply_ansi_escape (WINDOW *w, const char *buf)
{
ui_file_style style = last_style;
size_t n_read;
if (!style.parse (buf, &n_read))
return n_read;
if (reverse_mode_p)
{
/* We want to reverse _only_ the default foreground/background
colors. If the foreground color is not the default (because
the text was styled), we want to leave it as is. If e.g.,
the terminal is fg=BLACK, and bg=WHITE, and the style wants
to print text in RED, we want to reverse the background color
(print in BLACK), but still print the text in RED. To do
that, we enable the A_REVERSE attribute, and re-reverse the
parsed-style's fb/bg colors.
Notes on the approach:
- there's no portable way to know which colors the default
fb/bg colors map to.
- this approach does the right thing even if you change the
terminal colors while GDB is running -- the reversed
colors automatically adapt.
*/
if (!style.is_default ())
{
ui_file_style::color bg = style.get_background ();
ui_file_style::color fg = style.get_foreground ();
style.set_fg (bg);
style.set_bg (fg);
}
/* Enable A_REVERSE. */
style.set_reverse (true);
}
tui_apply_style (w, style);
return n_read;
}
/* See tui.io.h. */
void
tui_set_reverse_mode (WINDOW *w, bool reverse)
{
ui_file_style style = last_style;
reverse_mode_p = reverse;
style.set_reverse (reverse);
if (reverse)
{
reverse_save_bg = style.get_background ();
reverse_save_fg = style.get_foreground ();
}
else
{
style.set_bg (reverse_save_bg);
style.set_fg (reverse_save_fg);
}
tui_apply_style (w, style);
}
/* Print LENGTH characters from the buffer pointed to by BUF to the
curses command window. The output is buffered. It is up to the
caller to refresh the screen if necessary. */
void
tui_write (const char *buf, size_t length)
{
/* We need this to be \0-terminated for the regexp matching. */
std::string copy (buf, length);
tui_puts (copy.c_str ());
}
static void
tui_puts_internal (WINDOW *w, const char *string, int *height)
{
char c;
int prev_col = 0;
bool saw_nl = false;
while ((c = *string++) != 0)
{
if (c == '\n')
saw_nl = true;
if (c == '\1' || c == '\2')
{
/* Ignore these, they are readline escape-marking
sequences. */
}
else
{
if (c == '\033')
{
size_t bytes_read = apply_ansi_escape (w, string - 1);
if (bytes_read > 0)
{
string = string + bytes_read - 1;
continue;
}
}
do_tui_putc (w, c);
if (height != nullptr)
{
int col = getcurx (w);
if (col <= prev_col)
++*height;
prev_col = col;
}
}
}
if (TUI_CMD_WIN != nullptr && w == TUI_CMD_WIN->handle.get ())
update_cmdwin_start_line ();
if (saw_nl)
wrefresh (w);
}
/* Print a string in the curses command window. The output is
buffered. It is up to the caller to refresh the screen if
necessary. */
void
tui_puts (const char *string, WINDOW *w)
{
if (w == nullptr)
w = TUI_CMD_WIN->handle.get ();
tui_puts_internal (w, string, nullptr);
}
/* Readline callback.
Redisplay the command line with its prompt after readline has
changed the edited text. */
void
tui_redisplay_readline (void)
{
int prev_col;
int height;
int col;
int c_pos;
int c_line;
int in;
WINDOW *w;
const char *prompt;
int start_line;
/* Detect when we temporarily left SingleKey and now the readline
edit buffer is empty, automatically restore the SingleKey
mode. The restore must only be done if the command has finished.
The command could call prompt_for_continue and we must not
restore SingleKey so that the prompt and normal keymap are used. */
if (tui_current_key_mode == TUI_ONE_COMMAND_MODE && rl_end == 0
&& !gdb_in_secondary_prompt_p (current_ui))
tui_set_key_mode (TUI_SINGLE_KEY_MODE);
if (tui_current_key_mode == TUI_SINGLE_KEY_MODE)
prompt = "";
else
prompt = rl_display_prompt;
c_pos = -1;
c_line = -1;
w = TUI_CMD_WIN->handle.get ();
start_line = TUI_CMD_WIN->start_line;
wmove (w, start_line, 0);
prev_col = 0;
height = 1;
if (prompt != nullptr)
tui_puts_internal (w, prompt, &height);
prev_col = getcurx (w);
for (in = 0; in <= rl_end; in++)
{
unsigned char c;
if (in == rl_point)
{
getyx (w, c_line, c_pos);
}
if (in == rl_end)
break;
c = (unsigned char) rl_line_buffer[in];
if (CTRL_CHAR (c) || c == RUBOUT)
{
waddch (w, '^');
waddch (w, CTRL_CHAR (c) ? UNCTRL (c) : '?');
}
else if (c == '\t')
{
/* Expand TABs, since ncurses on MS-Windows doesn't. */
col = getcurx (w);
do
{
waddch (w, ' ');
col++;
} while ((col % 8) != 0);
}
else
{
waddch (w, c);
}
if (c == '\n')
TUI_CMD_WIN->start_line = getcury (w);
col = getcurx (w);
if (col < prev_col)
height++;
prev_col = col;
}
wclrtobot (w);
TUI_CMD_WIN->start_line = getcury (w);
if (c_line >= 0)
wmove (w, c_line, c_pos);
TUI_CMD_WIN->start_line -= height - 1;
wrefresh (w);
fflush(stdout);
}
/* Readline callback to prepare the terminal. It is called once each
time we enter readline. Terminal is already setup in curses
mode. */
static void
tui_prep_terminal (int notused1)
{
}
/* Readline callback to restore the terminal. It is called once each
time we leave readline. There is nothing to do in curses mode. */
static void
tui_deprep_terminal (void)
{
}
#ifdef TUI_USE_PIPE_FOR_READLINE
/* Read readline output pipe and feed the command window with it.
Should be removed when readline is clean. */
static void
tui_readline_output (int error, gdb_client_data data)
{
int size;
char buf[256];
size = read (tui_readline_pipe[0], buf, sizeof (buf) - 1);
if (size > 0 && tui_active)
{
buf[size] = 0;
tui_puts (buf);
}
}
#endif
/* TUI version of displayer.crlf. */
static void
tui_mld_crlf (const struct match_list_displayer *displayer)
{
tui_putc ('\n');
}
/* TUI version of displayer.putch. */
static void
tui_mld_putch (const struct match_list_displayer *displayer, int ch)
{
tui_putc (ch);
}
/* TUI version of displayer.puts. */
static void
tui_mld_puts (const struct match_list_displayer *displayer, const char *s)
{
tui_puts (s);
}
/* TUI version of displayer.flush. */
static void
tui_mld_flush (const struct match_list_displayer *displayer)
{
wrefresh (TUI_CMD_WIN->handle.get ());
}
/* TUI version of displayer.erase_entire_line. */
static void
tui_mld_erase_entire_line (const struct match_list_displayer *displayer)
{
WINDOW *w = TUI_CMD_WIN->handle.get ();
int cur_y = getcury (w);
wmove (w, cur_y, 0);
wclrtoeol (w);
wmove (w, cur_y, 0);
}
/* TUI version of displayer.beep. */
static void
tui_mld_beep (const struct match_list_displayer *displayer)
{
beep ();
}
/* A wrapper for wgetch that enters nonl mode. We We normally want
curses' "nl" mode, but when reading from the user, we'd like to
differentiate between C-j and C-m, because some users bind these
keys differently in their .inputrc. So, put curses into nonl mode
just when reading from the user. See PR tui/20819. */
static int
gdb_wgetch (WINDOW *win)
{
nonl ();
int r = wgetch (win);
nl ();
return r;
}
/* Helper function for tui_mld_read_key.
This temporarily replaces tui_getc for use during tab-completion
match list display. */
static int
tui_mld_getc (FILE *fp)
{
WINDOW *w = TUI_CMD_WIN->handle.get ();
int c = gdb_wgetch (w);
return c;
}
/* TUI version of displayer.read_key. */
static int
tui_mld_read_key (const struct match_list_displayer *displayer)
{
rl_getc_func_t *prev = rl_getc_function;
int c;
/* We can't use tui_getc as we need NEWLINE to not get emitted. */
rl_getc_function = tui_mld_getc;
c = rl_read_key ();
rl_getc_function = prev;
return c;
}
/* TUI version of rl_completion_display_matches_hook.
See gdb_display_match_list for a description of the arguments. */
static void
tui_rl_display_match_list (char **matches, int len, int max)
{
struct match_list_displayer displayer;
rl_get_screen_size (&displayer.height, &displayer.width);
displayer.crlf = tui_mld_crlf;
displayer.putch = tui_mld_putch;
displayer.puts = tui_mld_puts;
displayer.flush = tui_mld_flush;
displayer.erase_entire_line = tui_mld_erase_entire_line;
displayer.beep = tui_mld_beep;
displayer.read_key = tui_mld_read_key;
gdb_display_match_list (matches, len, max, &displayer);
}
/* Setup the IO for curses or non-curses mode.
- In non-curses mode, readline and gdb use the standard input and
standard output/error directly.
- In curses mode, the standard output/error is controlled by TUI
with the tui_stdout and tui_stderr. The output is redirected in
the curses command window. Several readline callbacks are installed
so that readline asks for its input to the curses command window
with wgetch(). */
void
tui_setup_io (int mode)
{
extern int _rl_echoing_p;
if (mode)
{
/* Ensure that readline has been initialized before saving any
of its variables. */
tui_ensure_readline_initialized ();
/* Redirect readline to TUI. */
tui_old_rl_redisplay_function = rl_redisplay_function;
tui_old_rl_deprep_terminal = rl_deprep_term_function;
tui_old_rl_prep_terminal = rl_prep_term_function;
tui_old_rl_getc_function = rl_getc_function;
tui_old_rl_display_matches_hook = rl_completion_display_matches_hook;
tui_old_rl_outstream = rl_outstream;
tui_old_rl_echoing_p = _rl_echoing_p;
rl_redisplay_function = tui_redisplay_readline;
rl_deprep_term_function = tui_deprep_terminal;
rl_prep_term_function = tui_prep_terminal;
rl_getc_function = tui_getc;
_rl_echoing_p = 0;
rl_outstream = tui_rl_outstream;
rl_prompt = 0;
rl_completion_display_matches_hook = tui_rl_display_match_list;
rl_already_prompted = 0;
/* Keep track of previous gdb output. */
tui_old_stdout = gdb_stdout;
tui_old_stderr = gdb_stderr;
tui_old_uiout = dynamic_cast<cli_ui_out *> (current_uiout);
gdb_assert (tui_old_uiout != nullptr);
/* Reconfigure gdb output. */
gdb_stdout = tui_stdout;
gdb_stderr = tui_stderr;
gdb_stdlog = gdb_stdout; /* for moment */
gdb_stdtarg = gdb_stderr; /* for moment */
gdb_stdtargerr = gdb_stderr; /* for moment */
current_uiout = tui_out;
/* Save tty for SIGCONT. */
savetty ();
}
else
{
/* Restore gdb output. */
gdb_stdout = tui_old_stdout;
gdb_stderr = tui_old_stderr;
gdb_stdlog = gdb_stdout; /* for moment */
gdb_stdtarg = gdb_stderr; /* for moment */
gdb_stdtargerr = gdb_stderr; /* for moment */
current_uiout = tui_old_uiout;
/* Restore readline. */
rl_redisplay_function = tui_old_rl_redisplay_function;
rl_deprep_term_function = tui_old_rl_deprep_terminal;
rl_prep_term_function = tui_old_rl_prep_terminal;
rl_getc_function = tui_old_rl_getc_function;
rl_completion_display_matches_hook = tui_old_rl_display_matches_hook;
rl_outstream = tui_old_rl_outstream;
_rl_echoing_p = tui_old_rl_echoing_p;
rl_already_prompted = 0;
/* Save tty for SIGCONT. */
savetty ();
/* Clean up color information. */
last_color_pair = -1;
last_style = ui_file_style ();
color_map.clear ();
color_pair_map.clear ();
}
}
#ifdef SIGCONT
/* Catch SIGCONT to restore the terminal and refresh the screen. */
static void
tui_cont_sig (int sig)
{
if (tui_active)
{
/* Restore the terminal setting because another process (shell)
might have changed it. */
resetty ();
/* Force a refresh of the screen. */
tui_refresh_all_win ();
}
signal (sig, tui_cont_sig);
}
#endif
/* Initialize the IO for gdb in curses mode. */
void
tui_initialize_io (void)
{
#ifdef SIGCONT
signal (SIGCONT, tui_cont_sig);
#endif
/* Create tui output streams. */
tui_stdout = new tui_file (stdout);
tui_stderr = new tui_file (stderr);
tui_out = tui_out_new (tui_stdout);
/* Create the default UI. */
tui_old_uiout = cli_out_new (gdb_stdout);
#ifdef TUI_USE_PIPE_FOR_READLINE
/* Temporary solution for readline writing to stdout: redirect
readline output in a pipe, read that pipe and output the content
in the curses command window. */
if (gdb_pipe_cloexec (tui_readline_pipe) != 0)
error (_("Cannot create pipe for readline"));
tui_rl_outstream = fdopen (tui_readline_pipe[1], "w");
if (tui_rl_outstream == 0)
error (_("Cannot redirect readline output"));
setvbuf (tui_rl_outstream, NULL, _IOLBF, 0);
#ifdef O_NONBLOCK
(void) fcntl (tui_readline_pipe[0], F_SETFL, O_NONBLOCK);
#else
#ifdef O_NDELAY
(void) fcntl (tui_readline_pipe[0], F_SETFL, O_NDELAY);
#endif
#endif
add_file_handler (tui_readline_pipe[0], tui_readline_output, 0);
#else
tui_rl_outstream = stdout;
#endif
#ifdef __MINGW32__
/* MS-Windows port of ncurses doesn't support default foreground and
background colors, so we must record the default colors at startup. */
HANDLE hstdout = (HANDLE)_get_osfhandle (fileno (stdout));
DWORD cmode;
CONSOLE_SCREEN_BUFFER_INFO csbi;
if (hstdout != INVALID_HANDLE_VALUE
&& GetConsoleMode (hstdout, &cmode) != 0
&& GetConsoleScreenBufferInfo (hstdout, &csbi))
ncurses_norm_attr = csbi.wAttributes;
#endif
}
/* Dispatch the correct tui function based upon the control
character. */
static unsigned int
tui_dispatch_ctrl_char (unsigned int ch)
{
struct tui_win_info *win_info = tui_win_with_focus ();
/* Handle the CTRL-L refresh for each window. */
if (ch == '\f')
tui_refresh_all_win ();
/* If no window has the focus, or if the focus window can't scroll,
just pass the character through. */
if (win_info == NULL || !win_info->can_scroll ())
return ch;
switch (ch)
{
case KEY_NPAGE:
win_info->forward_scroll (0);
break;
case KEY_PPAGE:
win_info->backward_scroll (0);
break;
case KEY_DOWN:
case KEY_SF:
win_info->forward_scroll (1);
break;
case KEY_UP:
case KEY_SR:
win_info->backward_scroll (1);
break;
case KEY_RIGHT:
win_info->left_scroll (1);
break;
case KEY_LEFT:
win_info->right_scroll (1);
break;
case '\f':
break;
default:
/* We didn't recognize the character as a control character, so pass it
through. */
return ch;
}
/* We intercepted the control character, so return 0 (which readline
will interpret as a no-op). */
return 0;
}
/* Main worker for tui_getc. Get a character from the command window.
This is called from the readline package, but wrapped in a
try/catch by tui_getc. */
static int
tui_getc_1 (FILE *fp)
{
int ch;
WINDOW *w;
w = TUI_CMD_WIN->handle.get ();
#ifdef TUI_USE_PIPE_FOR_READLINE
/* Flush readline output. */
tui_readline_output (0, 0);
#endif
ch = gdb_wgetch (w);
/* The \n must be echoed because it will not be printed by
readline. */
if (ch == '\n' || ch == '\r')
{
/* When hitting return with an empty input, gdb executes the last
command. If we emit a newline, this fills up the command window
with empty lines with gdb prompt at beginning. Instead of that,
stay on the same line but provide a visual effect to show the
user we recognized the command. */
if (rl_end == 0 && !gdb_in_secondary_prompt_p (current_ui))
{
wmove (w, getcury (w), 0);
/* Clear the line. This will blink the gdb prompt since
it will be redrawn at the same line. */
wclrtoeol (w);
wrefresh (w);
napms (20);
}
else
{
/* Move cursor to the end of the command line before emitting the
newline. We need to do so because when ncurses outputs a newline
it truncates any text that appears past the end of the cursor. */
int px, py;
getyx (w, py, px);
px += rl_end - rl_point;
py += px / TUI_CMD_WIN->width;
px %= TUI_CMD_WIN->width;
wmove (w, py, px);
tui_putc ('\n');
}
}
/* Handle prev/next/up/down here. */
ch = tui_dispatch_ctrl_char (ch);
if (ch == KEY_BACKSPACE)
return '\b';
if (current_ui->command_editing && key_is_start_sequence (ch))
{
int ch_pending;
nodelay (w, TRUE);
ch_pending = gdb_wgetch (w);
nodelay (w, FALSE);
/* If we have pending input following a start sequence, call the stdin
event handler again because ncurses may have already read and stored
the input into its internal buffer, meaning that we won't get an stdin
event for it. If we don't compensate for this missed stdin event, key
sequences as Alt_F (^[f) will not behave promptly.
(We only compensates for the missed 2nd byte of a key sequence because
2-byte sequences are by far the most commonly used. ncurses may have
buffered a larger, 3+-byte key sequence though it remains to be seen
whether it is useful to compensate for all the bytes of such
sequences.) */
if (ch_pending != ERR)
{
ungetch (ch_pending);
call_stdin_event_handler_again_p = 1;
}
}
return ch;
}
/* Get a character from the command window. This is called from the
readline package. */
static int
tui_getc (FILE *fp)
{
try
{
return tui_getc_1 (fp);
}
catch (const gdb_exception &ex)
{
/* Just in case, don't ever let an exception escape to readline.
This shouldn't ever happen, but if it does, print the
exception instead of just crashing GDB. */
exception_print (gdb_stderr, ex);
/* If we threw an exception, it's because we recognized the
character. */
return 0;
}
}