Merge upstream LLDB r194487:

  Log failure to restore thread state in ThreadPlanCallFunction::DoTakedown

  In order to help track down llvm.org/pr17226.

Sponsored by:	DARPA, AFRL

2 files changed, 6 insertions, 3 deletions

diff --git a/contrib/llvm/tools/lldb/source/Target/Thread.cpp b/contrib/llvm/tools/lldb/source/Target/Thread.cpp
index 98c26019b4a1..de3314540b48 100644
--- a/contrib/llvm/tools/lldb/source/Target/Thread.cpp
+++ b/contrib/llvm/tools/lldb/source/Target/Thread.cpp
@@ -511,8 +511,7 @@ Thread::CheckpointThreadState (ThreadStateCheckpoint &saved_state)
 bool
 Thread::RestoreRegisterStateFromCheckpoint (ThreadStateCheckpoint &saved_state)
 {
-    RestoreSaveFrameZero(saved_state.register_backup);
-    return true;
+    return RestoreSaveFrameZero(saved_state.register_backup);
 }
 
 bool
diff --git a/contrib/llvm/tools/lldb/source/Target/ThreadPlanCallFunction.cpp b/contrib/llvm/tools/lldb/source/Target/ThreadPlanCallFunction.cpp
index c9baaafffd6a..45ff3b4ba5d8 100644
--- a/contrib/llvm/tools/lldb/source/Target/ThreadPlanCallFunction.cpp
+++ b/contrib/llvm/tools/lldb/source/Target/ThreadPlanCallFunction.cpp
@@ -299,7 +299,11 @@ ThreadPlanCallFunction::DoTakedown (bool success)
         m_takedown_done = true;
         m_stop_address = m_thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC();
         m_real_stop_info_sp = GetPrivateStopInfo ();
-        m_thread.RestoreRegisterStateFromCheckpoint(m_stored_thread_state);
+        if (!m_thread.RestoreRegisterStateFromCheckpoint(m_stored_thread_state))
+        {
+            if (log)
+                log->Printf("ThreadPlanCallFunction(%p): DoTakedown failed to restore register state", this);
+        }
         SetPlanComplete(success);
         ClearBreakpoints();
         if (log && log->GetVerbose())