[PATCH] D23283: Debugging of optimized code: When locals have their address taken as part of a call use their stack slots as location expressions for debug info.

[Adrian Prantl via llvm-commits]

aprantl added a comment.

Thanks!

Why does this need to be restricted to "simple" derefs? I understand that it's easier to convince ourselves that a single DW_OP_deref is correct, but do you have a counterexample where checking whether the first opcode in the expression is a deref would not be correct?

I haven't checked the code yet, but maybe you already know the answer: Does this also work if the variable has more than one value? If the FrameIndexDbgValue also gets lowered into DBG_VALUE we should be fine. If it ends up as a stack slot entry in the MMI table the following example should break:

  void foo(bool c) {
    int i = 0;
    if (c)
      i = 1;
    else
      bar(&i)
    return i;
  }


https://reviews.llvm.org/D23283