Find holes in C structs due to alignment

Question

Is there a way in gcc or clang (or any other compiler) to spit information about whether a struct has holes (memory alignment - wise) in it ?

Thank you.

ps: If

Answer 1

You could explore this question by writing probe code for a particular struct using sizeof and &; if sizeof the nth member isn't equal to the address of the next member minus the address of that member, there's a hole.