CODEWITHSUNDEEP
cllvm
Hif
Hif

Reputation: 165

Get variable name in LLVM pass

I have following LLVM IR and I want to extract the variable name string from the store instruction. Please guide me on how can I do this.

 %call = call noalias i8* @malloc(i64 100) #3
 store i8* %call, i8** %string, align 8

My LLVM pass looks like

virtual bool runOnModule(Module &M) {
  for (Function &F: M) { 
    for (BasicBlock &B: F) {
        for (Instruction &I: B) {
            if(CallInst* call_inst = dyn_cast<CallInst>(&I)) {
                Function* fn = call_inst->getCalledFunction();
                StringRef fn_name = fn->getName();
                errs() << fn_name << " : " << call_inst->getArgOperand(0) << "\n";
                //for(auto args = fn->arg_begin(); args != fn->arg_end(); ++args) {
                    //  ConstantInt* arg = dyn_cast<ConstantInt>(&(*args));
                    //  errs() << arg->getValue() << "\n";
                //}    
            } else {
                       errs() << I.getName() << "\n" << I.getOpcodeName();
            }
    }
     }  
  }
  return false;
}

Upvotes: 4

Views: 3097

Answers (1)

arrowd
arrowd

Reputation: 34411

After checking that I is a StoreInst you can iterate between I.op_begin() and I.op_end():

for (auto op = I.op_begin(); op != I.op_end(); op++) {
  Value* v = op.get();
  StringRef name = v->getName();
}

Upvotes: 3

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