+dnl _XC_OVR_ZZ40_WITNESS
+dnl -------------------------------------------------
+dnl Private macro.
+dnl
+dnl Emits shell code that allows knowing wether macro
+dnl XC_CONFIGURE_PREAMBLE has expanded before configure
+dnl body begins, and if it has suceeded when configure
+dnl finally runs. Results are recorded in config.log
+
+AC_DEFUN([_XC_OVR_ZZ40_WITNESS],
+[dnl
+m4_divert_text([BODY],
+[dnl
+#
+# Witness that XC_CONFIGURE_PREAMBLE has been used.
+#
+
+if test -z "$xc_configure_preamble_result"; then
+ AC_MSG_WARN([a macro expansion problem has been detected])
+ if test -z "$PATH_SEPARATOR"; then
+ AC_MSG_ERROR([variable 'PATH_SEPARATOR' not set (internal problem)])
+ fi
+else
+ AC_MSG_CHECKING([whether some basic commands and utilities are available])
+ AC_MSG_RESULT([$xc_configure_preamble_result])
+fi
+])dnl
+])
+
+