+dnl Test for gcc 9 or later. Some incremental tests fail with GCC 9 or
+dnl later.
+AC_CACHE_CHECK([for gcc >= 9], [gold_cv_prog_gcc9],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+#if !defined __GNUC__ || __GNUC__ < 9
+error
+#endif
+])], [gold_cv_prog_gcc9=yes], [gold_cv_prog_gcc9=no])])
+AM_CONDITIONAL(GCC9, [test "$gold_cv_prog_gcc9" = "yes"])
+
+dnl Test for -fcf-protection on x86-64. Some incremental tests fail with
+dnl -fcf-protection.
+AC_CACHE_CHECK([for -fcf-protection], [gold_cv_cflags_cf_protection],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+#if !defined __x86_64__ || !defined __CET__
+error
+#endif
+])], [gold_cv_cflags_cf_protection=yes], [gold_cv_cflags_cf_protection=no])])
+AM_CONDITIONAL(CFLAGS_CF_PROTECTION, [test "$gold_cv_cflags_cf_protection" = "yes"])
+