])
+dnl Ensure we do not use a buggy M4.
+m4_if(m4_index([..wi.d.], [.d.]), [-1],
+ [m4_fatal(m4_do([m4 with buggy strstr detected. Please install
+GNU M4 1.4.16 or newer and set the M4 environment variable]))])
+
+
dnl Fix 2.64 cross compile detection for AVR and RTEMS
dnl by not trying to compile fopen.
m4_if(m4_defn([m4_PACKAGE_VERSION]), [2.64],