diff --git a/lldb/source/Core/SourceManager.cpp b/lldb/source/Core/SourceManager.cpp
--- a/lldb/source/Core/SourceManager.cpp
+++ b/lldb/source/Core/SourceManager.cpp
@@ -696,7 +696,7 @@
 }
 
 void SourceManager::SourceFileCache::AddSourceFile(const FileSP &file_sp) {
-  FileSpec file_spec;
+  FileSpec file_spec = file_sp->GetFileSpec();
   FileCache::iterator pos = m_file_cache.find(file_spec);
   if (pos == m_file_cache.end())
     m_file_cache[file_spec] = file_sp;