Using ${.ALLSRC} here is dangerious as it sometimes picks up more

"sources" than desired.

gnu/usr.bin/cc/cpp0/Makefile

@@ -21,7 +21,7 @@ c-parse.c: c-parse.in
 	sed -e "/^ifobjc$$/,/^end ifobjc$$/d" \
 	    -e "/^ifc$$/d" \
 	    -e "/^end ifc$$/d" \
-	    ${.ALLSRC} > c-parse.y
+	    ${GCCDIR}/c-parse.in > c-parse.y
 	${YACC} -o c-parse.c.in c-parse.y
 	sed -e "s/malloc/xmalloc/g" \
 	    -e "s/realloc/xrealloc/g" \