__glibc_has_extension 55 maint/gnulib/lib/cdefs.h # define __glibc_has_extension(ext) __has_extension (ext) __glibc_has_extension 57 maint/gnulib/lib/cdefs.h # define __glibc_has_extension(ext) 0 __glibc_has_extension 149 maint/gnulib/lib/libc-config.h # undef __glibc_has_extension