[LLVMdev] problem with multiple LLVM passes

[Susan Horwitz]

I'm trying to write two LLVM passes, one of which uses the results of the
other.  The first is LiveVars and the second is RemoveUseless.  In the
RemoveUseless class I have:
   virtual void getAnalysisUsage(AnalysisUsage &AU) const {
     AU.addRequired<LiveVars>();
   }

This compiles fine, but when I try to run it I get an error:
       Pass class not registered!

The error goes away if I take out that "addRequired".

The code for the LiveVars pass includes
 	RegisterPass<LiveVars> X("liveVars", "Live vars analysis", true,
 	true);

and I can run the LiveVars pass like this:
 	opt -load Debug/lib/dataflowAnalysis.so -f -analyze -liveVars ...

I've tried running the RemoveUseless pass with various combinations of flags 
(just -removeUseless, both -liveVars and -removeUseles, with and without 
-analyze), but I always get the same error.


Any help will be much appreciated!