+/* --- @SOD__HAVE_VARARGS_MACROS@ --- *
+ *
+ * Use: Defined if the compiler supports C99-style variadic macros.
+ *
+ * This is more complicated than just checking the value of
+ * @__STDC_VERSION__@ because GCC has traditionally claimed C89
+ * by default, but provides the functionality anyway unless it's
+ * been explicitly turned off.
+ */
+
+#if __STDC_VERSION__ >= 199901
+ /* The feature exists. All is well with the world. */
+
+# define SOD__HAVE_VARARGS_MACROS
+
+#elif __GNUC__ >= 3
+ /* We're using GCC, which is trying to deny it but we don't believe it.
+ * Unfortunately there's a fly in the ointment: if `-pedantic' -- or,
+ * worse, `-pedantic-errors' -- is set, then GCC will warn about these
+ * macros being defined, and there isn't a way to detect pedantry from the
+ * preprocessor.
+ *
+ * We must deploy bodges. There doesn't seem to be a good way to suppress
+ * particular warnings from the preprocessor: in particular, messing about
+ * with `pragma GCC diagnostic' doesn't help. So we're left with this
+ * hack: just declare all Sod-generated header files which try to do
+ * varargs macro things to be `system headers', which means that GCC's
+ * preprocessor will let them get away with all manner of nefarious stuff.
+ */
+
+# define SOD__HAVE_VARARGS_MACROS
+# define SOD__VARARGS_MACROS_PREAMBLE _Pragma("GCC system_header")
+
+#endif
+
+/* Make sure this gratuitous hack is understood, at least vacuously. */
+#ifndef SOD__VARARGS_MACROS_PREAMBLE
+# define SOD__VARARGS_MACROS_PREAMBLE
+#endif
+
+/* We're going to want to make use of this ourselves. */
+SOD__VARARGS_MACROS_PREAMBLE
+