From: Tom de Vries <tdevries@suse.de>
To: gdb-patches@sourceware.org
Subject: [PATCH 2/2] [gdb/tui] Fix resizing of terminal to 1 or 2 lines
Date: Thu, 9 Nov 2023 13:04:55 +0100 [thread overview]
Message-ID: <20231109120455.4741-2-tdevries@suse.de> (raw)
In-Reply-To: <20231109120455.4741-1-tdevries@suse.de>
When starting TUI in a terminal with 3 lines:
...
$ echo $LINES
3
$ gdb -q -tui
...
and resizing the terminal to 2 lines we run into a segfault.
The problem is that for the source window:
- the minimum height is 3 (the default), but
- the maximum height is only 2 because there are only 2 lines.
This discrepancy eventually leads to a call to newwin in make_window with:
...
(gdb) p height
$1 = 3
(gdb) p width
$2 = 56
(gdb) p y
$3 = -1
(gdb) p x
$4 = 0
...
which results in a nullptr.
This violates the assumption here in tui_apply_current_layout:
....
/* Get the new list of currently visible windows. */
std::vector<tui_win_info *> new_tui_windows;
applied_layout->get_windows (&new_tui_windows);
...
that get_windows only returns visible windows, which leads to tui_windows
holding a dangling pointer, which results in the segfault.
Fix this by:
- making sure get_windows only returns visible windows, and
- detecting the situation and dropping windows from the layout if
there's no room for them.
Tested on x86_64-linux.
PR tui/31044
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31044
---
gdb/testsuite/gdb.tui/resize.exp | 9 +++++++++
gdb/tui/tui-layout.c | 22 ++++++++++++++++++++--
gdb/tui/tui-layout.h | 6 +++++-
3 files changed, 34 insertions(+), 3 deletions(-)
diff --git a/gdb/testsuite/gdb.tui/resize.exp b/gdb/testsuite/gdb.tui/resize.exp
index 60d5116886b..e15f8a2f507 100644
--- a/gdb/testsuite/gdb.tui/resize.exp
+++ b/gdb/testsuite/gdb.tui/resize.exp
@@ -39,3 +39,12 @@ Term::check_contents "source at startup" "\\|.*21 *return 0"
Term::resize 40 90
Term::check_box "source box after resize" 0 0 90 26
+
+# Check that resizing to less than 3 lines doesn't cause problems.
+foreach lines { 2 1 } {
+ with_test_prefix lines=$lines {
+ Term::resize $lines 90 0
+ Term::wait_for ""
+ Term::check_region_contents "has prompt" 0 0 90 $lines "$gdb_prompt"
+ }
+}
diff --git a/gdb/tui/tui-layout.c b/gdb/tui/tui-layout.c
index 159445dc520..4f8a4bc3bcc 100644
--- a/gdb/tui/tui-layout.c
+++ b/gdb/tui/tui-layout.c
@@ -452,6 +452,13 @@ tui_layout_window::apply (int x_, int y_, int width_, int height_,
width = width_;
height = height_;
gdb_assert (m_window != nullptr);
+ if (width == 0 || height == 0)
+ {
+ /* The window was dropped, so it's going to be deleted, reset the
+ soon to be dangling pointer. */
+ m_window = nullptr;
+ return;
+ }
m_window->resize (height, width, x, y);
}
@@ -833,6 +840,7 @@ tui_layout_split::apply (int x_, int y_, int width_, int height_,
int available_size = m_vertical ? height : width;
int last_index = -1;
int total_weight = 0;
+ int prev = -1;
for (int i = 0; i < m_splits.size (); ++i)
{
bool cmd_win_already_exists = TUI_CMD_WIN != nullptr;
@@ -864,6 +872,14 @@ tui_layout_split::apply (int x_, int y_, int width_, int height_,
info[i].max_size = info[i].min_size;
}
+ if (info[i].min_size > info[i].max_size)
+ {
+ /* There is not enough room for this window, drop it. */
+ info[i].min_size = 0;
+ info[i].max_size = 0;
+ continue;
+ }
+
if (info[i].min_size == info[i].max_size)
available_size -= info[i].min_size;
else
@@ -874,10 +890,12 @@ tui_layout_split::apply (int x_, int y_, int width_, int height_,
/* Two adjacent boxed windows will share a border, making a bit
more size available. */
- if (i > 0
- && m_splits[i - 1].layout->last_edge_has_border_p ()
+ if (prev != -1
+ && m_splits[prev].layout->last_edge_has_border_p ()
&& m_splits[i].layout->first_edge_has_border_p ())
info[i].share_box = true;
+
+ prev = i;
}
/* If last_index is set then we have a window that is not of a fixed
diff --git a/gdb/tui/tui-layout.h b/gdb/tui/tui-layout.h
index a6d34851bef..4d29c0570ac 100644
--- a/gdb/tui/tui-layout.h
+++ b/gdb/tui/tui-layout.h
@@ -189,7 +189,11 @@ class tui_layout_window : public tui_layout_base
/* See tui_layout_base::get_windows. */
void get_windows (std::vector<tui_win_info *> *windows) override
{
- windows->push_back (m_window);
+ if (m_window != nullptr && m_window->is_visible ())
+ {
+ /* Only get visible windows. */
+ windows->push_back (m_window);
+ }
}
protected:
--
2.35.3
next prev parent reply other threads:[~2023-11-09 12:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-09 12:04 [PATCH 1/2] [gdb/tui] Allow command window of " Tom de Vries
2023-11-09 12:04 ` Tom de Vries [this message]
2023-11-13 17:36 ` Tom Tromey
2023-11-13 20:20 ` Tom de Vries
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