Function builtin_diff

diff.c:3840–4154

}

static void builtin_diff(const char *name_a,
			 const char *name_b,
			 struct diff_filespec *one,
			 struct diff_filespec *two,
			 const char *xfrm_msg,
			 int must_show_header,
			 struct diff_options *o,
			 int complete_rewrite,
			 const struct range_set *line_ranges)
{
	mmfile_t mf1, mf2;
	const char *lbl[2];
	char *a_one, *b_two;
	const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
	const char *reset = diff_get_color_opt(o, DIFF_RESET);
	const char *a_prefix, *b_prefix;
	struct userdiff_driver *textconv_one = NULL;
	struct userdiff_driver *textconv_two = NULL;
	struct strbuf header = STRBUF_INIT;
	const char *line_prefix = diff_line_prefix(o);

	diff_set_mnemonic_prefix(o, "a/", "b/");
	if (o->flags.reverse_diff) {
		a_prefix = o->b_prefix;
		b_prefix = o->a_prefix;
	} else {
		a_prefix = o->a_prefix;
		b_prefix = o->b_prefix;
	}

	if (o->submodule_format == DIFF_SUBMODULE_LOG &&
	    (!one->mode || S_ISGITLINK(one->mode)) &&
	    (!two->mode || S_ISGITLINK(two->mode)) &&
	    (!diff_filepair_is_phoney(one, two))) {
		show_submodule_diff_summary(o, one->path ? one->path : two->path,
				&one->oid, &two->oid,
				two->dirty_submodule);
		o->found_changes = 1;
		return;
	} else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
		   (!one->mode || S_ISGITLINK(one->mode)) &&
		   (!two->mode || S_ISGITLINK(two->mode)) &&
		   (!diff_filepair_is_phoney(one, two))) {
		show_submodule_inline_diff(o, one->path ? one->path : two->path,
				&one->oid, &two->oid,
				two->dirty_submodule);
		o->found_changes = 1;
		return;
	}

	if (o->flags.allow_textconv) {
		textconv_one = get_textconv(o->repo, one);
		textconv_two = get_textconv(o->repo, two);
	}

	/* Never use a non-valid filename anywhere if at all possible */
	name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
	name_b = DIFF_FILE_VALID(two) ? name_b : name_a;