https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81393
--- Comment #9 from Ian Lance Taylor <ian at airs dot com> --- Created attachment 41791 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41791&action=edit Possible patch I agree that the simplest approach is to not try to pick up the definitions from the header files for the older branches, but to just write them directly. I don't have a way to test a patch; can you see if this one works?