https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89864
--- Comment #65 from Jürgen Reuter <juergen.reuter at desy dot de> --- (In reply to Jakub Jelinek from comment #64) > Why is this a [9 Regression] BTW? If the failure is while compiling > darwin-driver.c and caused by system headers using _Atomic even in C++, when > gcc/config/darwin-driver.c is identical between 8.x and 9.x (except for > copyright year in a comment), I don't understand how gcc 9 could fail to > build with XCode 10.2 while gcc 8.3 would succeed. Sorry, Jakub, when I first stumbled over the problem I thought that this was triggered by a change in the gcc trunk, until I realized it was a change in the XCode/system code. Indeed, it is not a regression.