Index: tools/dsymutil/DwarfLinker.cpp
===================================================================
--- tools/dsymutil/DwarfLinker.cpp
+++ tools/dsymutil/DwarfLinker.cpp
@@ -2449,6 +2449,8 @@
   Attr = Loc ? static_cast<DIEValueList *>(Loc)
              : static_cast<DIEValueList *>(Block);
 
+  assert(Attr && "DIEValue list needs to be not NULL");
+
   if (Loc)
     Value = DIEValue(dwarf::Attribute(AttrSpec.Attr),
                      dwarf::Form(AttrSpec.Form), Loc);