__has_attribute  2172 daemons/controld/controld_execd.c #if __has_attribute(fallthrough)
__has_attribute   691 include/config.h #ifdef __has_attribute
__has_attribute   692 include/config.h # define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__)
__has_attribute    42 maint/gnulib/lib/cdefs.h #if (defined __has_attribute \
__has_attribute    45 maint/gnulib/lib/cdefs.h # define __glibc_has_attribute(attr) __has_attribute (attr)