[llvm-dev] How can I call AAResults::getModRefInfo in module pass

[Xu Mingjie via llvm-dev]

Hi,

I' m writing a module pass with LLVM 7.0.0.

I want to use AAResults::getModRefInfo(const Instruction *I, const Optional<MemoryLocation> &OptLoc) to check if somes instructions may write the specified memory location in my module pass.



So in getAnalyisisUsage function of my pass I have:

    AU.addRequired<llvm::AAResultsWrapperPass>();

    AU.addRequired<llvm::DominatorTreeWrapperPass>();

    AU.addRequired<llvm::TargetLibraryInfoWrapperPass>();



And I get the AAResults by

    AAResults& AA = getAnalysis<AAResultsWrapperPass>(*I->getFunction()).getAAResults();



In the main function I define a legacy::PassManager, and I do this

    PassRegistry &Registry = *PassRegistry::getPassRegistry();

    initializeCore(Registry);

    initializeScalarOpts(Registry);

    initializeIPO(Registry);

    initializeAnalysis(Registry);

    initializeTransformUtils(Registry);

    initializeInstCombine(Registry);

    initializeInstrumentation(Registry);

    initializeTarget(Registry);



Then I call

    Passes.add(new MyModulePass());

    Passes.run(M);



However I get a segmentation fault when AAResults::getModRefInfo() encounters a StoreInst.

Could you please tell me if there is something that I’m doing wrong?



Thanks.