From e76eb034e25f53ef2c17eab700e95d07bbbdc7aa Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Mon, 7 Apr 2025 15:09:37 +0200 Subject: [PATCH] [gdb/tui] Don't try deferred curses initialization twice I noticed that if deferred curses initialization fails, for instance when using TERM=dumb, and we try the same again, we run into the same error: ... $ TERM=dumb gdb -batch -ex "tui enable" -ex "tui enable" Cannot enable the TUI: terminal doesn't support cursor addressing [TERM=dumb] Cannot enable the TUI: terminal doesn't support cursor addressing [TERM=dumb] ... I think it's better to try deferred curses initialization only once. Fix this by changing bool tui_finish_init into a tribool, and using TRIBOOL_UNKNOWN to represent the "initialization failed" state, such that we get instead: ... $ TERM=dumb gdb -batch -ex "tui enable" -ex "tui enable" Cannot enable the TUI: terminal doesn't support cursor addressing [TERM=dumb] Cannot enable the TUI ... Tested on x86_64-linux. --- gdb/tui/tui.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/gdb/tui/tui.c b/gdb/tui/tui.c index 59aa1bc1483..06a899e2418 100644 --- a/gdb/tui/tui.c +++ b/gdb/tui/tui.c @@ -67,7 +67,12 @@ show_tui_debug (struct ui_file *file, int from_tty, /* Tells whether the TUI is active or not. */ bool tui_active = false; -static bool tui_finish_init = true; + +/* Tells whether the TUI should do deferred curses initialization. + If TRIBOOL_TRUE, then yes. If TRIBOOL_FALSE. then no (because + initialization is already done). If TRIBOOL_UNKNOWN, then no (because + initialization failed). */ +static tribool tui_finish_init = TRIBOOL_TRUE; enum tui_key_mode tui_current_key_mode = TUI_COMMAND_MODE; @@ -390,7 +395,13 @@ tui_enable (void) /* To avoid to initialize curses when gdb starts, there is a deferred curses initialization. This initialization is made only once and the first time the curses mode is entered. */ - if (tui_finish_init) + if (tui_finish_init == TRIBOOL_UNKNOWN) + { + /* Initialization failed before, just throw a generic error, don't try + again. */ + error (_("Cannot enable the TUI")); + } + else if (tui_finish_init == TRIBOOL_TRUE) { WINDOW *w; SCREEN *s; @@ -410,6 +421,9 @@ tui_enable (void) if (!gdb_stderr->isatty ()) error (_("Cannot enable the TUI when output is not a terminal")); + /* Don't try initialization again. */ + tui_finish_init = TRIBOOL_UNKNOWN; + s = newterm (NULL, stdout, stdin); #ifdef __MINGW32__ /* The MinGW port of ncurses requires $TERM to be unset in order @@ -468,7 +482,7 @@ tui_enable (void) tui_set_win_focus_to (tui_src_win ()); keypad (tui_cmd_win ()->handle.get (), TRUE); wrefresh (tui_cmd_win ()->handle.get ()); - tui_finish_init = false; + tui_finish_init = TRIBOOL_FALSE; } else { base-commit: eaacf3d48a7f16f56d5a69d5fb03ac3638d7b957 -- 2.43.0