https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109836
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- This is already enabled by -Wall and -pedantic and error with -pedantic-errors, I'm not sure we want to warn by default here. At least, we'd need details on how many extra warnings does that result on real-world code. I think it doesn't create too much harm not to warn by default, especially because it is fine for aliasing.
