https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94337
--- Comment #3 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> --- Hmm... The code might actually be invalid, but I'm not sure. In all the accesses, the effective type is the union type. But the C standard does not say what happens when one takes the member of a union type. * If the effective type remains the same (a union), then using any pointer cast to another type would be invalid, but this could be unintuitive and break a lot of code (and GCC should have emitted a warning for both printf lines). * I suspect that the effective type is locally[*] changed to the type implied by the type of the union member (this would be consistent with the GCC warning). However, it seems that there is nothing about that in the C standard, probably because the above example is really a corner case. [*] not sure how this is supposed to mean precisely.
