On Wed, Apr 25, 2018 at 9:53 AM, Andrew Haley <a...@redhat.com> wrote: > On 04/25/2018 01:23 PM, Jonathan Wakely wrote: > >> We enabled -Wreturn-type by default in GCC 8, so code using the >> extension will get warnings even without -Wall now. Users might want >> to use -Werror=return-type to ensure they aren't bitten by the new >> optimizations that assume control never reaches the end of a >> non-void function. > > But ISO C++ allows control to reach the end of main(), and > automagically returns 0. I guess you didn't mean that, but your reply > was confusing. > > N4659, Section 6.6.1 Para 5: > > If control flows off the end of the compound-statement of main, the > effect is equivalent to a return with operand 0 (see also 18.3).
Indeed, so that optimization doesn't affect main, because there is no undefined behavior. The warning by default seems sufficient to me. Jason
