https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71851
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #2) > Any kind of such code goes strongly against build reproduceability, > -fcompare-debug etc., so not sure it would be really appreciated, it is a > direction against various changes done in gcc lately. > I think if you need something like that just pass > -DRANDOM=`dd if=/dev/random bs=8 count=1 2>/dev/null | md5sum | awk '{print > $1}'` > or something similar. I think he wants to have a new random value each time __RANDOM is "evaluated" (during C++ template instantiation - thus a preprocessor macro isn't really apppropriate).