Function cmd_diff

builtin/diff.c:399–651

}

int cmd_diff(int argc,
	     const char **argv,
	     const char *prefix,
	     struct repository *repo UNUSED)
{
	int i;
	struct rev_info rev;
	struct object_array ent = OBJECT_ARRAY_INIT;
	int first_non_parent = -1;
	int blobs = 0, paths = 0;
	struct object_array_entry *blob[2];
	int nongit = 0, no_index = 0;
	int result;
	struct symdiff sdiff;

	/*
	 * We could get N tree-ish in the rev.pending_objects list.
	 * Also there could be M blobs there, and P pathspecs. --cached may
	 * also be present.
	 *
	 * N=0, M=0:
	 *      cache vs files (diff-files)
	 *
	 * N=0, M=0, --cached:
	 *      HEAD vs cache (diff-index --cached)
	 *
	 * N=0, M=2:
	 *      compare two random blobs.  P must be zero.
	 *
	 * N=0, M=1, P=1:
	 *      compare a blob with a working tree file.
	 *
	 * N=1, M=0:
	 *      tree vs files (diff-index)
	 *
	 * N=1, M=0, --cached:
	 *      tree vs cache (diff-index --cached)
	 *
	 * N=2, M=0:
	 *      tree vs tree (diff-tree)
	 *
	 * N=0, M=0, P=2:
	 *      compare two filesystem entities (aka --no-index).
	 *
	 * Other cases are errors.
	 */

	/* Were we asked to do --no-index explicitly? */
	for (i = 1; i < argc; i++) {
		if (!strcmp(argv[i], "--")) {
			i++;
			break;
		}
		if (!strcmp(argv[i], "--no-index"))
			no_index = DIFF_NO_INDEX_EXPLICIT;
		if (argv[i][0] != '-')
			break;
	}