<rdar://problem/13194155>

Fixing an issue where threads and frames could get out of sync and cause ValueObjects to fail to retrieve their values correctly

llvm-svn: 177166

2 files changed, 16 insertions, 14 deletions

diff --git a/lldb/source/Target/ExecutionContext.cpp b/lldb/source/Target/ExecutionContext.cpp
index ae3fc20d028..9ace4c93b17 100644
--- a/lldb/source/Target/ExecutionContext.cpp
+++ b/lldb/source/Target/ExecutionContext.cpp
@@ -815,22 +815,20 @@ lldb::StackFrameSP
 ExecutionContextRef::GetFrameSP () const
 {
     lldb::StackFrameSP frame_sp (m_frame_wp.lock());
-    if (!frame_sp && m_stack_id.IsValid())
+    if (frame_sp)
     {
-        lldb::ThreadSP thread_sp (GetThreadSP());
-        if (thread_sp)
-        {
-            frame_sp = thread_sp->GetFrameWithStackID (m_stack_id);
-            m_frame_wp = frame_sp;
-        }
-        else
-        {
-            // If the thread that this frame was supposed to belong to is not valid, then
-            // return a NULL frame_sp.
-            frame_sp.reset();
-        }
+        lldb::ThreadSP frame_thread_sp(frame_sp->GetThread());
+        if (frame_thread_sp && frame_thread_sp->IsValid())
+            return frame_sp;
+    }
+    lldb::ThreadSP thread_sp (GetThreadSP());
+    if (thread_sp && thread_sp->IsValid())
+    {
+        frame_sp = thread_sp->GetFrameWithStackID (m_stack_id);
+        m_frame_wp = frame_sp;
+        return frame_sp;
     }
-    return frame_sp;
+    return lldb::StackFrameSP();
 }
 
 ExecutionContext
diff --git a/lldb/source/Target/StackFrameList.cpp b/lldb/source/Target/StackFrameList.cpp
index 0a45d33ea65..913456d2419 100644
--- a/lldb/source/Target/StackFrameList.cpp
+++ b/lldb/source/Target/StackFrameList.cpp
@@ -250,6 +250,10 @@ StackFrameList::SetCurrentInlinedDepth (uint32_t new_depth)
 void
 StackFrameList::GetFramesUpTo(uint32_t end_idx)
 {
+    // this makes sure we do not fetch frames for an invalid thread
+    if (m_thread.IsValid() == false)
+        return;
+
     // We've already gotten more frames than asked for, or we've already finished unwinding, return.
     if (m_frames.size() > end_idx || GetAllFramesFetched())
         return;