[Question][Hw3] coverage of phi node + necessity of functions in Utils

[AnHaechan]

I found out the provided function Utils.debug_location returns None when PHI instruction is fed as its argument.

But according to the specification of the homework, we need to instrument __coverage__ for every instruction except instruction s.t. Utils.is_debug instruction = true, and I also checked the PHI node is really a 'instruction' In LLVM IR, from the LLVM document.

(1) Then, should we somehow get debug information of phi node without depending on the provided function in Utils?

I have one more question related to module Utils.
I really thought hard to come up with the reason why do I need some functions in Utils such as find_main, is_print, is_unary_op, string_of_exp but it was difficult to find out their usage.
For find_main, is_print, is_input, I don't understand why should we consider specific functions.
For is_assignment, is_unary_op, is_binary_op, I don't think method of inserting __coverage__ will differ because of the kind of instrunction..

(2) Are these things really necessary for good sanitizer?
If so, can you spare me some hints..?

Thanks.

[KihongHeo]

You can ignore all instructions such that Utils.debug_location returns None.