Instrumenting C/C++ code using LLVM

Question

I want to write a LLVM pass to instrument every memory access. Here is what I am trying to do.

Given any C/C++ program (like the one given below), I am trying to insert

Answer 1

Try something like this: ( you need to fill in the blanks and make the iterator loop work despite the fact that items are being inserted )

class ThePass : public llvm::BasicBlockPass {
  public:
  ThePass() : BasicBlockPass() {}
  virtual bool runOnBasicBlock(llvm::BasicBlock &bb);
};
bool ThePass::runOnBasicBlock(BasicBlock &bb) {
  bool retval = false;
  for (BasicBlock::iterator bbit = bb.begin(), bbie = bb.end(); bbit != bbie;
   ++bbit) { // Make loop work given updates
   Instruction *i = bbit;

   CallInst * beforeCall = // INSERT THIS
   beforeCall->insertBefore(i);

   if (!i->isTerminator()) {
      CallInst * afterCall = // INSERT THIS
      afterCall->insertAfter(i);
   }
  }
  return retval;
}

Hope this helps!