+extern int git_diff_config(const char *var, const char *value);
+extern void diff_setup(struct diff_options *);
+extern int diff_opt_parse(struct diff_options *, const char **, int);
+extern int diff_setup_done(struct diff_options *);
+
+#define DIFF_DETECT_RENAME 1
+#define DIFF_DETECT_COPY 2
+
+#define DIFF_PICKAXE_ALL 1
+
+extern void diffcore_std(struct diff_options *);
+
+extern void diffcore_std_no_resolve(struct diff_options *);
+
+#define COMMON_DIFF_OPTIONS_HELP \
+"\ncommon diff options:\n" \
+" -z output diff-raw with lines terminated with NUL.\n" \
+" -p output patch format.\n" \
+" -u synonym for -p.\n" \
+" --name-only show only names of changed files.\n" \
+" --name-status show names and status of changed files.\n" \
+" --full-index show full object name on index ines.\n" \
+" -R swap input file pairs.\n" \
+" -B detect complete rewrites.\n" \
+" -M detect renames.\n" \
+" -C detect copies.\n" \
+" --find-copies-harder\n" \
+" try unchanged files as candidate for copy detection.\n" \
+" -l<n> limit rename attempts up to <n> paths.\n" \
+" -O<file> reorder diffs according to the <file>.\n" \
+" -S<string> find filepair whose only one side contains the string.\n" \
+" --pickaxe-all\n" \
+" show all files diff when -S is used and hit is found.\n"