Re: [PATCH v4 2/2] diff: add SUBMODULE_DIFF format to display submodule diff

diff --git a/submodule.c b/submodule.c
index 1b5cdfb7e784..36f8fd00c3ce 100644
--- a/submodule.c
+++ b/submodule.c

@@ -333,6 +333,73 @@ static void print_submodule_summary(struct rev_info *rev, FILE *f,
 	strbuf_release(&sb);
 }
 
+void show_submodule_diff(FILE *f, const char *path,
+		const char *line_prefix,
+		unsigned char one[20], unsigned char two[20],
+		unsigned dirty_submodule, const char *meta,
+		const char *a_prefix, const char *b_prefix,
+		const char *reset)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+	struct strbuf sb = STRBUF_INIT;
+	struct strbuf submodule_git_dir = STRBUF_INIT;
+	const char *git_dir, *message = NULL;
+	int create_dirty_diff = 0;
+	FILE *diff;
+	char c;