+# Set the standard the C library headers should conform to.
+AH_VERBATIM([_POSIX_C_SOURCE], [/* The targeted POSIX standard. */
+#ifndef _POSIX_C_SOURCE
+# define _POSIX_C_SOURCE 200112L
+#endif])
+
+# Get compiler versions.
+SR_PROG_VERSION([$CC], [srd_cc_version])
+