+#define DIFF_FORMAT_RAW 1
+#define DIFF_FORMAT_PATCH 2
+#define DIFF_FORMAT_NO_OUTPUT 3
+#define DIFF_FORMAT_NAME 4
+#define DIFF_FORMAT_NAME_STATUS 5
+
+extern void diff_flush(struct diff_options*);
+
+/* diff-raw status letters */
+#define DIFF_STATUS_ADDED 'A'
+#define DIFF_STATUS_COPIED 'C'
+#define DIFF_STATUS_DELETED 'D'
+#define DIFF_STATUS_MODIFIED 'M'
+#define DIFF_STATUS_RENAMED 'R'
+#define DIFF_STATUS_TYPE_CHANGED 'T'
+#define DIFF_STATUS_UNKNOWN 'X'
+#define DIFF_STATUS_UNMERGED 'U'
+
+/* these are not diff-raw status letters proper, but used by
+ * diffcore-filter insn to specify additional restrictions.
+ */
+#define DIFF_STATUS_FILTER_AON '*'
+#define DIFF_STATUS_FILTER_BROKEN 'B'