# Specify the output files to avoid problems on different file systems.
AT_CHECK([bison calc.y -o calc.c patsubst([$1], [--yyerror-verbose])],
[0], [], [])
-AT_CHECK([$CC $CFLAGS calc.c -o calc], 0, [], [])
+AT_CHECK([$CC $CFLAGS $CPPFLAGS calc.c -o calc], 0, [], [])
# Test the priorities.
_AT_CHECK_CALC([$1],