[LLVMdev] Adding required function passes to CallGraphSCCPass

[Trevor Harmon]

Hi,

I have a FunctionPass that needs to process functions in bottom-up  
order on the call graph (callees before callers). CallGraphSCCPass can  
provide this ordering, but there's a snag. My pass depends on other  
passes, such as UnifyFunctionExitNodes and LoopInfo, to process the  
functions first. With a FunctionPass, I can specify these dependencies  
in FunctionPass::getAnalysisUsage, but if I convert the pass to a  
CallGraphSCCPass, I'm not sure what to do. Specifying the same pass  
dependencies in CallGraphSCCPass::getAnalysisUsage causes "Unable to  
schedule pass" errors. Any suggestions? Thanks,

Trevor