Jason Merrill <ja...@redhat.com> writes: > You shouldn't have to change any of those, just configure with CC="gcc > -fwhatever".
If it were so simple... Many Makefiles come with a habit of using not CC_FOR_BUILD, but just `cc', to build programs which are run on the build machine. These programs are intended to be as portable as possible (naturally, since Autoconf does not configure for the build machine). As a result, they are typically written in the subset of ANSI C that will compile with almost any C compiler, which is exactly what will cause problems with GCC's proposed new defaults.
