Make LLDB skip server-client roundtrip for signals that don't require any actions

If QPassSignals packaet is supported by lldb-server, lldb-client will
utilize it and ask the server to ignore signals that don't require stops
or notifications.
Such signals will be immediately re-injected into inferior to continue
normal execution.

Differential Revision: https://reviews.llvm.org/D30520

llvm-svn: 297231

1 files changed, 14 insertions, 0 deletions

diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index d0651e6bda7..e2006f4bbc3 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -2778,6 +2778,10 @@ Error Process::Launch(ProcessLaunchInfo &launch_info) {
             if (!m_os_ap)
                 LoadOperatingSystemPlugin(false);
 
+            // We successfully launched the process and stopped,
+            // now it the right time to set up signal filters before resuming.
+            UpdateAutomaticSignalFiltering();
+
             // Note, the stop event was consumed above, but not handled. This
             // was done
             // to give DidLaunch a chance to run. The target is either stopped
@@ -3257,6 +3261,10 @@ Error Process::PrivateResume() {
                 m_mod_id.GetStopID(), StateAsCString(m_public_state.GetValue()),
                 StateAsCString(m_private_state.GetValue()));
 
+  // If signals handing status changed we might want to update
+  // our signal filters before resuming.
+  UpdateAutomaticSignalFiltering();
+
   Error error(WillResume());
   // Tell the process it is about to resume before the thread list
   if (error.Success()) {
@@ -6219,3 +6227,9 @@ bool Process::RouteAsyncStructuredData(
   find_it->second->HandleArrivalOfStructuredData(*this, type_name, object_sp);
   return true;
 }
+
+Error Process::UpdateAutomaticSignalFiltering() {
+  // Default implementation does nothign.
+  // No automatic signal filtering to speak of.
+  return Error();
+}