This fixes a bug where a member function pointer signed using a function type with noexcept as the discriminator was being authenticated using a function type without noexcept.
Fixes https://github.com/llvm/llvm-project/issues/106487.
Implement tests for the following PAuth-related features:
- driver, preprocessor and ELF codegen tests for type_info vtable
pointer discrimination #99726;
- driver, preprocessor, and ELF codegen (emitting function attributes) +
sema (emitting errors) tests for indirect gotos signing #97647;
- ELF codegen tests for ubsan type checks + auth #99590;
- ELF codegen tests for constant global init with polymorphic MI #99741;
- ELF codegen tests for C++ member function pointers auth #99576.
Introduces type based signing of member function pointers. To support
this discrimination schema we no longer emit member function pointer to
virtual methods and indices into a vtable but migrate to using thunks.
This does mean member function pointers are no longer necessarily
directly comparable, however as such comparisons are UB this is
acceptable.
We derive the discriminator from the C++ mangling of the type of the
pointer being authenticated.
Co-Authored-By: Akira Hatanaka ahatanaka@apple.com
Co-Authored-By: John McCall rjmccall@apple.com
Co-authored-by: Ahmed Bougacha <ahmed@bougacha.org>
