From: Tom de Vries Date: Sun, 30 Apr 2023 11:06:23 +0000 (+0200) Subject: [gdb/tui] Fix TUI resizing for TERM=ansi X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=deb1ba4e38bf1427d4297b1e9b3e5e73cbc9e456;p=binutils-gdb.git [gdb/tui] Fix TUI resizing for TERM=ansi With TERM=ansi, when resizing a TUI window from LINES/COLUMNS 31/118 (maximized) to 20/78 (de-maximized), I get a garbled screen (that ^L doesn't fix) and a message: ... @@ resize done 0, size = 77x20 ... with the resulting width being 77 instead of the expected 78. [ The discrepancy also manifests in CLI, filed as PR30346. ] The discrepancy comes from tui_resize_all, where we ask readline for the screen size: ... rl_get_screen_size (&screenheight, &screenwidth); ... As it happens, when TERM is set to ansi, readline decides that the terminal cannot auto-wrap lines, and reserves one column to deal with that, and as a result reports back one less than the actual screen width: ... $ echo $COLUMNS 78 $ TERM=xterm gdb -ex "show width" -ex q Number of characters gdb thinks are in a line is 78. $ TERM=ansi gdb -ex "show width" -ex q Number of characters gdb thinks are in a line is 77. ... In tui_resize_all, we need the actual screen width, and using a screenwidth of one less than the actual value garbles the screen. This is currently not causing trouble in testing because we have a workaround in place in proc Term::resize. If we disable the workaround: ... - stty columns [expr {$_cols + 1}] < $::gdb_tty_name + stty columns $_cols < $::gdb_tty_name ... and dump the screen we get the same type of screen garbling: ... 0 +---------------------------------------+| 1 || 2 || 3 || ... Another way to reproduce the problem is using command "maint info screen". After starting gdb with TERM=ansi, entering TUI, and issuing the command, we get: ... Number of characters curses thinks are in a line is 78. ... and after maximizing and demaximizing the window we get: ... Number of characters curses thinks are in a line is 77. ... If we use TERM=xterm, we do get the expected 78. Fix this by: - detecting when readline will report back less than the actual screen width, - accordingly setting a new variable readline_hidden_cols, - using readline_hidden_cols in tui_resize_all to fix the resize problem, and - removing the workaround in Term::resize. The test-case gdb.tui/empty.exp serves as regression test. I've applied the same fix in tui_async_resize_screen, the new test-case gdb.tui/resize-2.exp serves as a regression test for that change. Without that fix, we have: ... FAIL: gdb.tui/resize-2.exp: again: gdb width 80 ... Tested on x86_64-linux. PR tui/30337 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30337 --- diff --git a/gdb/testsuite/gdb.tui/resize-2.exp b/gdb/testsuite/gdb.tui/resize-2.exp new file mode 100644 index 00000000000..ebe8216c05d --- /dev/null +++ b/gdb/testsuite/gdb.tui/resize-2.exp @@ -0,0 +1,89 @@ +# Copyright 2023 Free Software Foundation, Inc. + +# 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 . + +# Test TUI resizing using maint screen info command. + +require allow_tui_tests + +tuiterm_env + +Term::clean_restart 24 80 +set screen_dim { 0 0 80 24 } + +# Use a layout with just a command window. +gdb_test "tui new-layout command-layout cmd 1" + +if {![Term::prepare_for_tui]} { + unsupported "TUI not supported" + return 0 +} + +# Enter TUI. +Term::command_no_prompt_prefix "layout command-layout" + +proc check_width { what n } { + set re "Number of characters $what thinks are in a line is $n" + Term::check_region_contents "$what width $n" {*}$::screen_dim $re +} + +# Check that curses has the correct notion of screen width. +Term::command "maint info screen" +check_width curses 80 +check_width gdb 80 + +# Resize with TUI enabled, wait for the resize message. +Term::resize 40 90 +set screen_dim { 0 0 90 40 } + +# Check that curses has the correct notion of screen width after resize. +Term::command "maint info screen" +check_width curses 90 +check_width gdb 90 + +# Temporarily disable TUI. +gdb_test_multiple "tui disable" "" { + -re "$gdb_prompt $" { + pass $gdb_test_name + } +} + +# Resize with TUI disabled, so don't wait for the resize message. +Term::resize 24 80 0 +set screen_dim { 0 0 80 24 } +gdb_test_multiple "" "two prompt redisplays after resize" { + -re "\r.*$gdb_prompt \r.*$gdb_prompt $" { + pass $gdb_test_name + } +} + +# At this point, curses still thinks the width is 90. This doesn't look +# harmful because TUI is disabled. +gdb_test "maint info screen" \ + "\r\nNumber of characters curses thinks are in a line is 90.\\r\n.*" \ + "curses width after resize with TUI disabled" + +# Re-enable TUI. +send_gdb "tui enable\n" +# The "tui enable" command is issued on the CLI screen, on the TUI we have the +# last command issued there: "tui disable". +Term::wait_for "tui disable" + +# Check that curses has the correct notion of screen width after screen resize +# with TUI disabled. +Term::command "maint info screen" +with_test_prefix again { + check_width curses 80 + check_width gdb 80 +} diff --git a/gdb/testsuite/lib/tuiterm.exp b/gdb/testsuite/lib/tuiterm.exp index d8a99d2798a..8f78c320b66 100644 --- a/gdb/testsuite/lib/tuiterm.exp +++ b/gdb/testsuite/lib/tuiterm.exp @@ -1111,7 +1111,7 @@ namespace eval Term { } } - proc resize {rows cols} { + proc resize {rows cols {wait_for_msg 1}} { variable _rows variable _cols variable _resize_count @@ -1122,17 +1122,15 @@ namespace eval Term { # explicit here. This also simplifies waiting for the redraw. _do_resize $rows $_cols stty rows $_rows < $::gdb_tty_name - # Due to the strange column resizing behavior, and because we - # don't care about this intermediate resize, we don't check - # the size and the "@@ " prefix here. - wait_for "resize done $_resize_count" + if { $wait_for_msg } { + wait_for "@@ resize done $_resize_count, size = ${_cols}x${rows}" + } incr _resize_count - # Somehow the number of columns transmitted to gdb is one less - # than what we request from expect. We hide this weird - # details from the caller. _do_resize $_rows $cols - stty columns [expr {$_cols + 1}] < $::gdb_tty_name - wait_for "@@ resize done $_resize_count, size = ${_cols}x${rows}" + stty columns $_cols < $::gdb_tty_name + if { $wait_for_msg } { + wait_for "@@ resize done $_resize_count, size = ${_cols}x${rows}" + } incr _resize_count } } diff --git a/gdb/tui/tui-win.c b/gdb/tui/tui-win.c index 3b17cb8dd29..7eac03f47a1 100644 --- a/gdb/tui/tui-win.c +++ b/gdb/tui/tui-win.c @@ -36,6 +36,7 @@ #include "gdbsupport/event-loop.h" #include "gdbcmd.h" #include "async-event.h" +#include "utils.h" #include "tui/tui.h" #include "tui/tui-io.h" @@ -528,6 +529,8 @@ tui_resize_all (void) int screenheight, screenwidth; rl_get_screen_size (&screenheight, &screenwidth); + screenwidth += readline_hidden_cols; + width_diff = screenwidth - tui_term_width (); height_diff = screenheight - tui_term_height (); if (height_diff || width_diff) @@ -576,6 +579,7 @@ tui_async_resize_screen (gdb_client_data arg) int screen_height, screen_width; rl_get_screen_size (&screen_height, &screen_width); + screen_width += readline_hidden_cols; set_screen_width_and_height (screen_width, screen_height); /* win_resized is left set so that the next call to tui_enable() diff --git a/gdb/utils.c b/gdb/utils.c index 002a5885aff..e10198accd0 100644 --- a/gdb/utils.c +++ b/gdb/utils.c @@ -1116,6 +1116,14 @@ static bool filter_initialized = false; +/* See readline's rlprivate.h. */ + +EXTERN_C int _rl_term_autowrap; + +/* See utils.h. */ + +int readline_hidden_cols = 0; + /* Initialize the number of lines per page and chars per line. */ void @@ -1144,6 +1152,19 @@ init_page_info (void) /* Get the screen size from Readline. */ rl_get_screen_size (&rows, &cols); + + /* Readline: + - ignores the COLUMNS variable when detecting screen width + (because rl_prefer_env_winsize defaults to 0) + - puts the detected screen width in the COLUMNS variable + (because rl_change_environment defaults to 1) + - may report one less than the detected screen width in + rl_get_screen_size (when _rl_term_autowrap == 0). + We could set readline_hidden_cols by comparing COLUMNS to cols as + returned by rl_get_screen_size, but instead simply use + _rl_term_autowrap. */ + readline_hidden_cols = _rl_term_autowrap ? 0 : 1; + lines_per_page = rows; chars_per_line = cols; diff --git a/gdb/utils.h b/gdb/utils.h index a383036bcfe..29ff376bb52 100644 --- a/gdb/utils.h +++ b/gdb/utils.h @@ -335,4 +335,11 @@ extern void copy_bitwise (gdb_byte *dest, ULONGEST dest_offset, const gdb_byte *source, ULONGEST source_offset, ULONGEST nbits, int bits_big_endian); +/* When readline decides that the terminal cannot auto-wrap lines, it reduces + the width of the reported screen width by 1. This variable indicates + whether that's the case or not, allowing us to add it back where + necessary. See _rl_term_autowrap in readline/terminal.c. */ + +extern int readline_hidden_cols; + #endif /* UTILS_H */