[LLVMdev] The "scope" of passes
criswell at uiuc.edu
Mon Apr 12 07:03:51 PDT 2010
ether zhhb wrote:
> hi all,
> i have some thing not so sure about "scope" of llvm passes:
> suppose i have a function pass PassF and a BasicBlock analysis pass
> PassB. if i want to use the analysis result of PassB for a BasicBlock
> in PassF, i think i can create PassB in runOnFunction of PassF, and
> call runOnBasicBlock manually to get the result:
> PassB pb; //create a PassB
> //we also need consider the analysis usage of PassB
> pb.runOnBasicBlock(bb); // run PassB on bb manually
> .... use the result of pb ......
> is there any other better way?
I think the correct way to do this is to declare PassB as a prerequisite
pass in PassF's getAnalysisUsage() method and then to use
getAnalysis<PassB>(BasicBlock * BB) in PassF.
A ModulePass can use a FunctionPass, so I assume a FunctionPass can use
a BasicBlockPass in this fashion.
-- John T.
> thanks very much
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