[Bug c/81629] redefined memcpy leads to segmentation fault

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81629

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
             Status|ASSIGNED                    |NEW
          Component|middle-end                  |c
           Assignee|rguenth at gcc dot gnu.org         |unassigned at gcc dot gnu.org

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Oh.  The real issue is that the FE registers the function with the bogus
prototype as builtin.  So gimple_builtin_call_types_compatible_p sees the call
matches
the prototype.

That this is BUILT_IN_MEMCPY is simply a lie by the FE.

Still invalid input.

We also do not even warn about the bogus prototype given.