(no subject)

Hi,

I wrote an analysis pass, myPass, inherited from both ModulePass and ProfileInfo, and this pass requires the CallGraph, i.e.,

class myPass : public ModulePass, public ProfileInfo { …};

void myPass::getAnalysisUsage(AnalysisUsage &AU) const {

AU.addRequired();
AU.setPreservesAll();
}

Then, I assumes the UnreachableBlockElim (inherited from FunctionPass) requires myPass, by revising the related function as follows:

UnreachableBlockElim::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addPreserved();
AU.addPreserved();
AU.addRequired();

}

Then, i built it, it is OK. I went on to run it. It failed with a segment error.
By debugging, it is found that in the following code,

const PassInfo *PI = PassRegistry::getPassRegistry()->getPassInfo(*I);
AnalysisPass = PI->createPass();

The return value of PassRegistry::getPassInfo(const void *TI) is NULL, thus the following dereference of PI is invalid.
I am using llvm 2.9, which is download from http://llvm.org/releases/.

Could anybody help me?