https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108295
--- Comment #7 from Daniel Lundin <daniel.lundin.mail at gmail dot com> --- (In reply to Andrew Pinski from comment #6) > (In reply to Daniel Lundin from comment #5) > > (In reply to Andrew Pinski from comment #4) > > > Try -pedantic-errors. > > > > Yes I already did and then the error appears. But that would imply that this > > is a non-standard GNU extension and not an upcoming standard C23 feature, > > which still doesn't seem correct. > > > > If the intention was to add this as a GNU extension until formal release of > > C23, then the use of such GNU extensions will behave inconsistently between > > gcc <10.4 and gcc >11.0 when using the same compiler options. And I don't > > think that's documented anywhere either. > > https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gcc/Mixed-Labels-and-Declarations. > html#Mixed-Labels-and-Declarations > > Compared to > https://gcc.gnu.org/onlinedocs/gcc-9.5.0/gcc/Mixed-Declarations.html#Mixed- > Declarations > > Is definitely documented. Fair enough but GNU C mode is -std=gnu17 (the default setting), not -std=c17.
