+# Make sure that the compiler is able to generate an executable. If it
+# can't, we are probably in trouble. We don't care whether we can run the
+# executable--we might be using a cross compiler--we only care whether it
+# can be created. At this point the main configure script has set CC.
+echo "int main () { return 0; }" > conftest.c
+${CC} -o conftest ${CFLAGS} ${CPPFLAGS} ${LDFLAGS} conftest.c
+if [ $? = 0 ] && [ -s conftest ]; then
+ :
+else
+ echo 1>&2 "*** The command '${CC} -o conftest ${CFLAGS} ${CPPFLAGS} ${LDFLAGS} conftest.c' failed."
+ echo 1>&2 "*** You must set the environment variable CC to a working compiler."
+ rm -f conftest*
+ exit 1
+fi
+rm -f conftest*
+