Hi, After your change, EmitCFIStartProcImpl in MCAsmStreamer does not match the signature of the EmitCFIStartProcImpl in MCStreamer and you end up not overriding the original function. One of the places where "virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) = 0" would have helped. :) Specifically, adding virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) { EmitCFIStartProcImpl(Frame, false); } to MCAsmStreamer gets llvm to pass all tests. I'm not familiar with this part of llvm, but my guess about the right thing to do is to change EmitCFIStartProcImpl in MCStreamer to take the Simple flag; and have _all_ subclasses of MCStreamer respect that. -- Sanjoy Das http://playingwithpointers.com