#define RANGE_DIFF_CREATION_FACTOR_DEFAULT 60
+/*
+ * Compare series of commmits in RANGE1 and RANGE2, and emit to the
+ * standard output. NULL can be passed to DIFFOPT to use the built-in
+ * default.
+ */
int show_range_diff(const char *range1, const char *range2,
int creation_factor, int dual_color,
struct diff_options *diffopt);