I’m trying to write a tool that will take as input some C code containing structs. It will compile the code, then find and output the size and offset of any padding the compiler decides to add to structs within it. This is pretty straightforward to do by hand for a known struct using offsetof, sizeof, and some addition, but I can’t figure out an easy way to do it automatically for any input struct.
If I knew how to iterate through all elements in a struct, I think I could get the tool written with no problems, but as far as I know there’s no way to do that. I’m hoping some StackOverflow people will know a way. However, I’m not stuck in my approach, and I’m certainly open to any alternate approaches to finding padding in a struct.
Isn’t this what pahole does?