https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63765
--- Comment #12 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> --- > --- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> --- > Let's go with the one defining _XOPEN_SOURCE only for Solaris until someone > programs David's suggestion of the host-specific configure file. Huh? As I've just checked, both Solaris and Linux/x86_64 do fine without any definition of _XOPEN_SOURCE at all, as does AIX. Only if _XOPEN_SOURCE is defined at all does Solaris need a value >= 600 with C99 and beyond. The attached patch does just that. Rainer