[lldb] Do not stop the process on SIGWINCH by default.

[da-viper]

SIGWINCH is sent when the terminal window size changes.. Most people debugging do not want the process on this signal.

When using lldb-dap, the user may be using an integrated terminal and may resize the pane/window mulitple times when debugging. this causes the signal to be sent multiple times. It gets in the way.

The process ignores this signal by default

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Ebuka Ezike (da-viper)

Changes

SIGWINCH is sent when the terminal window size changes.. Most people debugging do not want the process on this signal.

When using lldb-dap, the user may be using an integrated terminal and may resize the pane/window mulitple times when debugging. this causes the signal to be sent multiple times. It gets in the way.

The process ignores this signal by default

---

Full diff: https://github.com/llvm/llvm-project/pull/163182.diff

2 Files Affected:

• (modified) lldb/source/Plugins/Process/Utility/GDBRemoteSignals.cpp (+1-1)
• (modified) lldb/source/Plugins/Process/Utility/LinuxSignals.cpp (+1-1)

diff --git a/lldb/source/Plugins/Process/Utility/GDBRemoteSignals.cpp b/lldb/source/Plugins/Process/Utility/GDBRemoteSignals.cpp
index 15981a2c1cb80..a8d18f774c361 100644
--- a/lldb/source/Plugins/Process/Utility/GDBRemoteSignals.cpp
+++ b/lldb/source/Plugins/Process/Utility/GDBRemoteSignals.cpp
@@ -47,7 +47,7 @@ void GDBRemoteSignals::Reset() {
   AddSignal(25,     "SIGXFSZ",      false,    true,   true,   "file size limit exceeded");
   AddSignal(26,     "SIGVTALRM",    false,    true,   true,   "virtual time alarm");
   AddSignal(27,     "SIGPROF",      false,    false,  false,  "profiling time alarm");
-  AddSignal(28,     "SIGWINCH",     false,    true,   true,   "window size changes");
+  AddSignal(28,     "SIGWINCH",     false,    false,   false,   "window size changes");
   AddSignal(29,     "SIGLOST",      false,    true,   true,   "resource lost");
   AddSignal(30,     "SIGUSR1",      false,    true,   true,   "user defined signal 1");
   AddSignal(31,     "SIGUSR2",      false,    true,   true,   "user defined signal 2");
diff --git a/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp b/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp
index 5346babc18576..dbbfc6a352e02 100644
--- a/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp
+++ b/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp
@@ -160,7 +160,7 @@ void LinuxSignals::Reset() {
   ADD_LINUX_SIGNAL(25,     "SIGXFSZ",      false,    true,   true,   "file size limit exceeded");
   ADD_LINUX_SIGNAL(26,     "SIGVTALRM",    false,    true,   true,   "virtual time alarm");
   ADD_LINUX_SIGNAL(27,     "SIGPROF",      false,    false,  false,  "profiling time alarm");
-  ADD_LINUX_SIGNAL(28,     "SIGWINCH",     false,    true,   true,   "window size changes");
+  ADD_LINUX_SIGNAL(28,     "SIGWINCH",     false,    false,   false,   "window size changes");
   ADD_LINUX_SIGNAL(29,     "SIGIO",        false,    true,   true,   "input/output ready/Pollable event", "SIGPOLL");
   ADD_LINUX_SIGNAL(30,     "SIGPWR",       false,    true,   true,   "power failure");
   ADD_LINUX_SIGNAL(31,     "SIGSYS",       false,    true,   true,   "invalid system call");

[JDevlieghere]

I think this is a good default.

[bulbazord]

+1

[bulbazord]

Can you add a line in the release notes about this change? I'm sure somebody will notice this change and we should have a place to point them.

[da-viper]

will do.

I also created an RFC just in case there is any reason it is off.
https://discourse.llvm.org/t/rfc-lldb-do-not-stop-the-process-on-signal-sigwinch-on-linux/88577

[DavidSpickett]

Sounds good to me. If it's not stopping on the BSDs or Darwin I don't see any particular reason it would stop on Linux.

In the release note, show the command to re-enable stopping for this signal.