Author: Jonas Devlieghere Date: 2025-07-03T10:21:49-07:00 New Revision: 2f75f658b18aed4bbcab391063bceb7ccaf8a6ec
URL: https://github.com/llvm/llvm-project/commit/2f75f658b18aed4bbcab391063bceb7ccaf8a6ec DIFF: https://github.com/llvm/llvm-project/commit/2f75f658b18aed4bbcab391063bceb7ccaf8a6ec.diff LOG: [lldb] Take a sledgehammer approach to resizing the statusline (#146578) Terminal resizing continues to be a source of statusline bugs, so much so that some users have started disabling it altogether. Different operating systems and terminal emulators exhibit subtly different behaviors, making it nearly impossible to handle resizing reliably across the board. This patch sidesteps those issues by clearing the entire screen when the terminal is resized. This avoids having to account for the previous, potentially wrapped statusline, the underlying cause of many of the aforementioned bugs. The obvious downside is that this clears the on-screen history, but I believe that’s a reasonable trade-off. Note that this only happens when resizing the terminal; when launching LLDB, the statusline is drawn without clearing the screen. rdar://154778410 Added: Modified: lldb/include/lldb/Core/Statusline.h lldb/source/Core/Statusline.cpp lldb/test/API/functionalities/statusline/TestStatusline.py Removed: ################################################################################ diff --git a/lldb/include/lldb/Core/Statusline.h b/lldb/include/lldb/Core/Statusline.h index 521b9f2526f6b..6bda153f822d2 100644 --- a/lldb/include/lldb/Core/Statusline.h +++ b/lldb/include/lldb/Core/Statusline.h @@ -36,12 +36,10 @@ class Statusline { /// Draw the statusline with the given text. void Draw(std::string msg); - /// Update terminal dimensions. - void UpdateTerminalProperties(); - enum ScrollWindowMode { EnableStatusline, DisableStatusline, + ResizeStatusline, }; /// Set the scroll window for the given mode. diff --git a/lldb/source/Core/Statusline.cpp b/lldb/source/Core/Statusline.cpp index 8ec57c9fa5bac..393d427241021 100644 --- a/lldb/source/Core/Statusline.cpp +++ b/lldb/source/Core/Statusline.cpp @@ -24,6 +24,7 @@ #define ANSI_SAVE_CURSOR ESCAPE "7" #define ANSI_RESTORE_CURSOR ESCAPE "8" #define ANSI_CLEAR_BELOW ESCAPE "[J" +#define ANSI_CLEAR_SCREEN ESCAPE "[2J" #define ANSI_SET_SCROLL_ROWS ESCAPE "[1;%ur" #define ANSI_TO_START_OF_ROW ESCAPE "[%u;1f" #define ANSI_REVERSE_VIDEO ESCAPE "[7m" @@ -41,10 +42,12 @@ Statusline::Statusline(Debugger &debugger) Statusline::~Statusline() { Disable(); } void Statusline::TerminalSizeChanged() { - UpdateTerminalProperties(); + m_terminal_width = m_debugger.GetTerminalWidth(); + m_terminal_height = m_debugger.GetTerminalHeight(); - // This definitely isn't signal safe, but the best we can do, until we - // have proper signal-catching thread. + UpdateScrollWindow(ResizeStatusline); + + // Draw the old statusline. Redraw(/*update=*/false); } @@ -85,13 +88,6 @@ void Statusline::Draw(std::string str) { locked_stream << ANSI_RESTORE_CURSOR; } -void Statusline::UpdateTerminalProperties() { - UpdateScrollWindow(DisableStatusline); - m_terminal_width = m_debugger.GetTerminalWidth(); - m_terminal_height = m_debugger.GetTerminalHeight(); - UpdateScrollWindow(EnableStatusline); -} - void Statusline::UpdateScrollWindow(ScrollWindowMode mode) { assert(m_terminal_width != 0 && m_terminal_height != 0); @@ -99,24 +95,33 @@ void Statusline::UpdateScrollWindow(ScrollWindowMode mode) { if (!stream_sp) return; - const unsigned scroll_height = - (mode == DisableStatusline) ? m_terminal_height : m_terminal_height - 1; - + const unsigned reduced_scroll_window = m_terminal_height - 1; LockedStreamFile locked_stream = stream_sp->Lock(); - if (mode == EnableStatusline) { + switch (mode) { + case EnableStatusline: // Move everything on the screen up. locked_stream << '\n'; locked_stream.Printf(ANSI_UP_ROWS, 1); - } - - locked_stream << ANSI_SAVE_CURSOR; - locked_stream.Printf(ANSI_SET_SCROLL_ROWS, scroll_height); - locked_stream << ANSI_RESTORE_CURSOR; - - if (mode == DisableStatusline) { + // Reduce the scroll window. + locked_stream << ANSI_SAVE_CURSOR; + locked_stream.Printf(ANSI_SET_SCROLL_ROWS, reduced_scroll_window); + locked_stream << ANSI_RESTORE_CURSOR; + break; + case DisableStatusline: + // Reset the scroll window. + locked_stream << ANSI_SAVE_CURSOR; + locked_stream.Printf(ANSI_SET_SCROLL_ROWS, 0); + locked_stream << ANSI_RESTORE_CURSOR; // Clear the screen below to hide the old statusline. locked_stream << ANSI_CLEAR_BELOW; + break; + case ResizeStatusline: + // Clear the screen and update the scroll window. + // FIXME: Find a better solution (#146919). + locked_stream << ANSI_CLEAR_SCREEN; + locked_stream.Printf(ANSI_SET_SCROLL_ROWS, reduced_scroll_window); + break; } m_debugger.RefreshIOHandler(); diff --git a/lldb/test/API/functionalities/statusline/TestStatusline.py b/lldb/test/API/functionalities/statusline/TestStatusline.py index ca2f10820d56d..087e62b387d77 100644 --- a/lldb/test/API/functionalities/statusline/TestStatusline.py +++ b/lldb/test/API/functionalities/statusline/TestStatusline.py @@ -67,9 +67,7 @@ def test(self): self.expect('set set separator "| "') # Hide the statusline and check or the control character. - self.expect( - "set set show-statusline false", ["\x1b[1;{}r".format(self.TERMINAL_HEIGHT)] - ) + self.expect("set set show-statusline false", ["\x1b[1;0r"]) def test_no_color(self): """Basic test for the statusline with colors disabled.""" @@ -114,6 +112,6 @@ def test_resize(self): self.resize() self.expect("set set show-statusline true", ["no target"]) self.resize(20, 60) - # Check for the escape code to resize the scroll window, followed by - # the prompt. - self.child.expect(re.escape("\x1b[1;19r\x1b8(lldb)")) + # Check for the escape code to resize the scroll window. + self.child.expect(re.escape("\x1b[1;19r")) + self.child.expect("(lldb)") _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
