[Lldb-commits] [lldb] Real-time console pane for output in lldb tui (PR #177160)
Nagesh Nazare via lldb-commits
lldb-commits at lists.llvm.org
Wed Jan 21 05:21:03 PST 2026
https://github.com/nageshnnazare updated https://github.com/llvm/llvm-project/pull/177160
>From 5b756054e45a6efc6792e031cd3d1ab33e416ac2 Mon Sep 17 00:00:00 2001
From: Nagesh Nazare <nageshnnazare at gmail.com>
Date: Wed, 21 Jan 2026 01:30:23 +0530
Subject: [PATCH] Adding Console window to lldb gui
This change implements the console window to output stdout / stderr
messages. Native lldb gui masks the output printed by the application
and it is difficult to debug if there are any required debug info
messages in the app.
---
lldb/source/Core/IOHandlerCursesGUI.cpp | 360 ++++++++++++++++++++++--
1 file changed, 342 insertions(+), 18 deletions(-)
diff --git a/lldb/source/Core/IOHandlerCursesGUI.cpp b/lldb/source/Core/IOHandlerCursesGUI.cpp
index 53d71db9b3b0c..437584f2361c2 100644
--- a/lldb/source/Core/IOHandlerCursesGUI.cpp
+++ b/lldb/source/Core/IOHandlerCursesGUI.cpp
@@ -6308,6 +6308,247 @@ HandleCharResult HelpDialogDelegate::WindowDelegateHandleChar(Window &window,
return eKeyHandled;
}
+class ConsoleOutputWindowDelegate : public WindowDelegate {
+private:
+ void PollProcessOutput() {
+ ExecutionContext exe_ctx =
+ m_debugger.GetCommandInterpreter().GetExecutionContext();
+ Process *process = exe_ctx.GetProcessPtr();
+
+ if (!process || !process->IsAlive()) return;
+
+ // Buffer for reading output
+ char buffer[1024];
+ Status error;
+
+ // Read stdout
+ size_t stdout_bytes = process->GetSTDOUT(buffer, sizeof(buffer) - 1, error);
+ if (stdout_bytes > 0) {
+ buffer[stdout_bytes] = '\0';
+ AppendOutput(buffer, false);
+ }
+
+ // Read stderr
+ size_t stderr_bytes = process->GetSTDERR(buffer, sizeof(buffer) - 1, error);
+ if (stderr_bytes > 0) {
+ buffer[stderr_bytes] = '\0';
+ AppendOutput(buffer, true);
+ }
+ }
+
+ void AppendOutput(const char *text, bool is_stderr) {
+ if (!text || text[0] == '\0') return;
+
+ std::lock_guard<std::mutex> lock(m_output_mutex);
+
+ // Split text into lines and add to buffer
+ std::string remaining = m_partial_line;
+ remaining += text;
+
+ size_t start = 0, pos = 0;
+ while ((pos = remaining.find('\n', start)) != std::string::npos) {
+ std::string line = remaining.substr(start, pos - start);
+ if (is_stderr) {
+ line = "[stderr] " + line;
+ }
+ m_output_lines.push_back(line);
+
+ // Keep buffer size under limit
+ while (m_output_lines.size() > m_max_lines) {
+ m_output_lines.pop_front();
+ if (m_first_visible_line > 0) {
+ --m_first_visible_line;
+ }
+ }
+
+ start = pos + 1;
+ }
+
+ // Save any remaining partial line
+ m_partial_line = remaining.substr(start);
+
+ // Auto-scroll to bottom if enabled
+ if (m_auto_scroll && !m_output_lines.empty()) {
+ m_first_visible_line =
+ m_output_lines.size() > 0 ? m_output_lines.size() - 1 : 0;
+ }
+ }
+
+public:
+ ConsoleOutputWindowDelegate(Debugger &debugger)
+ : m_debugger(debugger), m_first_visible_line(0),
+ m_auto_scroll(true), m_max_lines(10000) {}
+
+ ~ConsoleOutputWindowDelegate() override = default;
+
+ bool WindowDelegateDraw(Window &window, bool force) override {
+ // Poll for new output
+ PollProcessOutput();
+
+ std::lock_guard<std::mutex> lock(m_output_mutex);
+
+ window.Erase();
+ window.DrawTitleBox(window.GetName());
+
+ const int width = window.GetWidth();
+ const int height = window.GetHeight();
+
+ // Calculate the visible range
+ size_t total_lines = m_output_lines.size();
+ if (total_lines == 0) {
+ window.MoveCursor(2, 1);
+ window.PutCString("(no output yet)");
+ return true;
+ }
+
+ // Adjust scroll pos if needed
+ if (m_first_visible_line >= total_lines) {
+ m_first_visible_line =
+ total_lines > 0 ? total_lines - 1 : 0;
+ }
+
+ // Draw visible line
+ int visible_height = height - 2;
+ size_t start_line = m_first_visible_line;
+
+ // If we are at the end, display last N lines
+ if (m_auto_scroll || start_line + visible_height > total_lines) {
+ start_line =
+ total_lines > static_cast<size_t>(visible_height) ?
+ total_lines - visible_height : 0;
+ }
+
+ for (int row = 1; row <= visible_height &&
+ (start_line + row - 1) < total_lines; ++row) {
+ window.MoveCursor(2, row);
+ const std::string &line = m_output_lines[start_line + row - 1];
+
+ // Highlight stderr lines?
+ bool is_stderr = (line.find("[stderr]") == 0);
+ if (is_stderr) {
+ window.AttributeOn(COLOR_PAIR(2));
+ }
+
+ // Truncate line to fit window width
+ int available_width = width - 3;
+ if (static_cast<int>(line.length()) > available_width) {
+ window.PutCString(line.substr(0, available_width).c_str());
+ } else {
+ window.PutCString(line.c_str());
+ }
+
+ if (is_stderr) {
+ window.AttributeOff(COLOR_PAIR(2));
+ }
+ }
+
+ return true;
+ }
+
+ HandleCharResult WindowDelegateHandleChar(Window &window, int key) override {
+ std::lock_guard<std::mutex> lock(m_output_mutex);
+
+ size_t total_lines = m_output_lines.size();
+ int visible_height = window.GetHeight() - 1;
+
+ switch (key) {
+ case KEY_UP:
+ if (m_first_visible_line > 0) {
+ --m_first_visible_line;
+ m_auto_scroll = false;
+ }
+ return eKeyHandled;
+
+ case KEY_DOWN:
+ if (m_first_visible_line + visible_height < total_lines) {
+ ++m_first_visible_line;
+ }
+ // Re-enable Auto-scroll at bottom
+ if (m_first_visible_line + visible_height >= total_lines) {
+ m_auto_scroll = true;
+ }
+ return eKeyHandled;
+
+ case KEY_PPAGE:
+ if (m_first_visible_line > static_cast<size_t>(visible_height)) {
+ m_first_visible_line -= visible_height;
+ } else {
+ m_first_visible_line = 0;
+ }
+ m_auto_scroll = false;
+ return eKeyHandled;
+
+ case KEY_NPAGE:
+ m_first_visible_line += visible_height;
+ if (m_first_visible_line + visible_height >= total_lines) {
+ m_first_visible_line = total_lines > static_cast<size_t>(visible_height)
+ ? total_lines - visible_height : 0;
+ m_auto_scroll = true;
+ }
+ return eKeyHandled;
+
+ case 'a':
+ m_auto_scroll = !m_auto_scroll;
+ if (m_auto_scroll && total_lines > 0) {
+ m_first_visible_line = total_lines > static_cast<size_t>(visible_height)
+ ? total_lines - visible_height : 0;
+ }
+ return eKeyHandled;
+
+ case 'c':
+ m_output_lines.clear();
+ m_partial_line.clear();
+ m_first_visible_line = 0;
+ return eKeyHandled;
+
+ case KEY_HOME:
+ m_first_visible_line = 0;
+ m_auto_scroll = false;
+ return eKeyHandled;
+
+ case KEY_END:
+ m_first_visible_line = total_lines > static_cast<size_t>(visible_height)
+ ? total_lines - visible_height : 0;
+ m_auto_scroll = true;
+ return eKeyHandled;
+
+ default:
+ break;
+ }
+
+ return eKeyNotHandled;
+ }
+
+ const char *WindowDelegateGetHelpText() override {
+ return "Console Output view shows stdout and stderr from the process.";
+ }
+
+ KeyHelp *WindowDelegateGetKeyHelp() override {
+ static curses::KeyHelp g_source_view_key_help[] = {
+ {KEY_UP, "Scroll up"},
+ {KEY_DOWN, "Scroll down"},
+ {KEY_PPAGE, "Page up"},
+ {KEY_NPAGE, "Page down"},
+ {KEY_HOME, "Go to top"},
+ {KEY_END, "Go to bottom"},
+ {'h', "Show help dialog"},
+ {'a', "Toggle auto-scroll"},
+ {'c', "Clear output"},
+ {'\0', nullptr}};
+ return g_source_view_key_help;
+ }
+
+protected:
+ Debugger &m_debugger;
+ std::deque<std::string> m_output_lines;
+ std::string m_partial_line;
+ size_t m_first_visible_line = 0;
+ bool m_auto_scroll = true;
+ size_t m_max_lines = 10000;
+ std::mutex m_output_mutex;
+};
+
+
class ApplicationDelegate : public WindowDelegate, public MenuDelegate {
public:
enum {
@@ -6339,6 +6580,7 @@ class ApplicationDelegate : public WindowDelegate, public MenuDelegate {
eMenuID_ViewSource,
eMenuID_ViewVariables,
eMenuID_ViewBreakpoints,
+ eMenuId_ViewConsole,
eMenuID_Help,
eMenuID_HelpGUIHelp
@@ -6579,6 +6821,7 @@ class ApplicationDelegate : public WindowDelegate, public MenuDelegate {
WindowSP main_window_sp = m_app.GetMainWindow();
WindowSP source_window_sp = main_window_sp->FindSubWindow("Source");
WindowSP variables_window_sp = main_window_sp->FindSubWindow("Variables");
+ WindowSP console_window_sp = main_window_sp->FindSubWindow("Console");
WindowSP registers_window_sp = main_window_sp->FindSubWindow("Registers");
const Rect source_bounds = source_window_sp->GetBounds();
@@ -6587,39 +6830,50 @@ class ApplicationDelegate : public WindowDelegate, public MenuDelegate {
main_window_sp->RemoveSubWindow(variables_window_sp.get());
- if (registers_window_sp) {
+ if (console_window_sp) {
+ Rect console_bounds = console_window_sp->GetBounds();
+ console_bounds.origin.x = variables_bounds.origin.x;
+ console_bounds.size.width = variables_bounds.size.width + console_bounds.size.width;
+ console_window_sp->SetBounds(console_bounds);
+ } else if (registers_window_sp) {
// We have a registers window, so give all the area back to the
// registers window
Rect registers_bounds = variables_bounds;
registers_bounds.size.width = source_bounds.size.width;
registers_window_sp->SetBounds(registers_bounds);
} else {
- // We have no registers window showing so give the bottom area back
+ // We have no console or registers window showing so give the bottom area back
// to the source view
source_window_sp->Resize(source_bounds.size.width,
source_bounds.size.height +
variables_bounds.size.height);
}
} else {
- Rect new_variables_rect;
- if (registers_window_sp) {
+ Rect new_vars_rect;
+ if (console_window_sp) {
+ // Console exists, so split the area
+ const Rect console_bounds = console_window_sp->GetBounds();
+ Rect new_console_rect;
+ console_bounds.VerticalSplitPercentage(0.50, new_vars_rect,
+ new_console_rect);
+ } else if (registers_window_sp) {
// We have a registers window so split the area of the registers
// window into two columns where the left hand side will be the
// variables and the right hand side will be the registers
- const Rect variables_bounds = registers_window_sp->GetBounds();
- Rect new_registers_rect;
- variables_bounds.VerticalSplitPercentage(0.50, new_variables_rect,
- new_registers_rect);
- registers_window_sp->SetBounds(new_registers_rect);
+ const Rect registers_bounds = registers_window_sp->GetBounds();
+ Rect new_regs_rect;
+ registers_bounds.VerticalSplitPercentage(0.50, new_vars_rect,
+ new_regs_rect);
+ registers_window_sp->SetBounds(new_regs_rect);
} else {
- // No registers window, grab the bottom part of the source window
+ // No registers or console window, grab the bottom part of the source window
Rect new_source_rect;
source_bounds.HorizontalSplitPercentage(0.70, new_source_rect,
- new_variables_rect);
+ new_vars_rect);
source_window_sp->SetBounds(new_source_rect);
}
WindowSP new_window_sp = main_window_sp->CreateSubWindow(
- "Variables", new_variables_rect, false);
+ "Variables", new_vars_rect, false);
new_window_sp->SetDelegate(
WindowDelegateSP(new FrameVariablesWindowDelegate(m_debugger)));
}
@@ -6678,6 +6932,67 @@ class ApplicationDelegate : public WindowDelegate, public MenuDelegate {
}
return MenuActionResult::Handled;
+ case eMenuId_ViewConsole: {
+ WindowSP main_window_sp = m_app.GetMainWindow();
+ WindowSP source_window_sp = main_window_sp->FindSubWindow("Source");
+ WindowSP console_window_sp = main_window_sp->FindSubWindow("Console");
+ WindowSP variables_window_sp = main_window_sp->FindSubWindow("Variables");
+ WindowSP registers_window_sp = main_window_sp->FindSubWindow("Registers");
+ const Rect source_bounds = source_window_sp->GetBounds();
+
+ if (console_window_sp) {
+ const Rect console_bounds = console_window_sp->GetBounds();
+ main_window_sp->RemoveSubWindow(console_window_sp.get());
+
+ if (variables_window_sp) {
+ // Variables window exists, so give Console space to Variables
+ Rect variables_bounds = variables_window_sp->GetBounds();
+ variables_bounds.size.width = variables_bounds.size.width +
+ console_bounds.size.width;
+ variables_window_sp->SetBounds(variables_bounds);
+ } else if (registers_window_sp) {
+ // Registers window exists, so give Console space to Registers
+ Rect registers_bounds = registers_window_sp->GetBounds();
+ registers_bounds.size.width = source_bounds.size.width;
+ registers_window_sp->SetBounds(registers_bounds);
+ } else {
+ // No Variables or Registers window exists
+ source_window_sp->Resize(source_bounds.size.width,
+ source_bounds.size.height +
+ console_bounds.size.height);
+ }
+ } else {
+ Rect new_console_rect;
+ if (variables_window_sp) {
+ // Variable window exists, split area
+ const Rect variables_bounds = variables_window_sp->GetBounds();
+ Rect new_vars_rect;
+ variables_bounds.VerticalSplitPercentage(0.50, new_vars_rect,
+ new_console_rect);
+ variables_window_sp->SetBounds(new_vars_rect);
+ } else if (registers_window_sp) {
+ // Registers window exists, split area
+ const Rect registers_bounds = registers_window_sp->GetBounds();
+ Rect new_regs_rect;
+ registers_bounds.VerticalSplitPercentage(0.50, new_console_rect,
+ new_regs_rect);
+ registers_window_sp->SetBounds(new_regs_rect);
+ } else {
+ // No Registers or Variables window exists, split source area
+ Rect new_source_rect;
+ source_bounds.HorizontalSplitPercentage(0.70, new_source_rect,
+ new_console_rect);
+ source_window_sp->SetBounds(new_source_rect);
+ }
+ WindowSP new_window_sp =
+ main_window_sp->CreateSubWindow("Console", new_console_rect, false);
+ new_window_sp->SetDelegate(
+ WindowDelegateSP(new ConsoleOutputWindowDelegate(m_debugger)));
+ }
+ touchwin(stdscr);
+ }
+ return MenuActionResult::Handled;
+
case eMenuID_ViewBreakpoints: {
WindowSP main_window_sp = m_app.GetMainWindow();
WindowSP threads_window_sp = main_window_sp->FindSubWindow("Threads");
@@ -7629,9 +7944,10 @@ void IOHandlerCursesGUI::Activate() {
"Source", nullptr, 's', ApplicationDelegate::eMenuID_ViewSource));
view_menu_sp->AddSubmenu(std::make_shared<Menu>(
"Variables", nullptr, 'v', ApplicationDelegate::eMenuID_ViewVariables));
- view_menu_sp->AddSubmenu(
- std::make_shared<Menu>("Breakpoints", nullptr, 'b',
- ApplicationDelegate::eMenuID_ViewBreakpoints));
+ view_menu_sp->AddSubmenu(std::make_shared<Menu>(
+ "Breakpoints", nullptr, 'b', ApplicationDelegate::eMenuID_ViewBreakpoints));
+ view_menu_sp->AddSubmenu(std::make_shared<Menu>(
+ "Console", nullptr, 'o', ApplicationDelegate::eMenuId_ViewConsole));
MenuSP help_menu_sp(
new Menu("Help", "F6", KEY_F(6), ApplicationDelegate::eMenuID_Help));
@@ -7655,12 +7971,16 @@ void IOHandlerCursesGUI::Activate() {
Rect status_bounds = content_bounds.MakeStatusBar();
Rect source_bounds;
Rect variables_bounds;
+ Rect console_bounds;
Rect threads_bounds;
Rect source_variables_bounds;
+ Rect variables_console_bounds;
content_bounds.VerticalSplitPercentage(0.80, source_variables_bounds,
threads_bounds);
source_variables_bounds.HorizontalSplitPercentage(0.70, source_bounds,
- variables_bounds);
+ variables_console_bounds);
+ variables_console_bounds.VerticalSplitPercentage(0.50, variables_bounds,
+ console_bounds);
WindowSP menubar_window_sp =
main_window_sp->CreateSubWindow("Menubar", menubar_bounds, false);
@@ -7672,10 +7992,12 @@ void IOHandlerCursesGUI::Activate() {
WindowSP source_window_sp(
main_window_sp->CreateSubWindow("Source", source_bounds, true));
- WindowSP variables_window_sp(
- main_window_sp->CreateSubWindow("Variables", variables_bounds, false));
WindowSP threads_window_sp(
main_window_sp->CreateSubWindow("Threads", threads_bounds, false));
+ WindowSP variables_window_sp(
+ main_window_sp->CreateSubWindow("Variables", variables_bounds, false));
+ WindowSP console_window_sp(
+ main_window_sp->CreateSubWindow("Console", console_bounds, false));
WindowSP status_window_sp(
main_window_sp->CreateSubWindow("Status", status_bounds, false));
status_window_sp->SetCanBeActive(
@@ -7686,6 +8008,8 @@ void IOHandlerCursesGUI::Activate() {
WindowDelegateSP(new SourceFileWindowDelegate(m_debugger)));
variables_window_sp->SetDelegate(
WindowDelegateSP(new FrameVariablesWindowDelegate(m_debugger)));
+ console_window_sp->SetDelegate(
+ WindowDelegateSP(new ConsoleOutputWindowDelegate(m_debugger)));
TreeDelegateSP thread_delegate_sp(new ThreadsTreeDelegate(m_debugger));
threads_window_sp->SetDelegate(WindowDelegateSP(
new TreeWindowDelegate(m_debugger, thread_delegate_sp)));
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