Function Pointer Wrapper

Implmentation Specific Caveats

• Any new pass has to ensure that the check_ret is not added to any function matching _recfi_wrap, this change has been made for two and multi
• The wrapper pass has to run before the cfi pass
• We check if the wrapper is calling an internal function, however, if we pass an external function to the wrapper creator, this will fail (this can only happen if we are passing a deference of pointer to a pointer to a function as an argument).