use SWAP macro

Apply the semantic patch swap.cocci to convert hand-rolled swaps to use
the macro SWAP.  The resulting code is shorter and easier to read, the
object code is effectively unchanged.

The patch for object.c had to be hand-edited in order to preserve the
comment before the change; Coccinelle tried to eat it for some reason.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/diff.c b/diff.c
index f08cd8e03..9de1ba264 100644
--- a/diff.c
+++ b/diff.c
@@ -5118,13 +5118,11 @@ void diff_change(struct diff_options *options,
 
 	if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
 		unsigned tmp;
-		const unsigned char *tmp_c;
-		tmp = old_mode; old_mode = new_mode; new_mode = tmp;
-		tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
+		SWAP(old_mode, new_mode);
+		SWAP(old_sha1, new_sha1);
 		tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
 			new_sha1_valid = tmp;
-		tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
-			new_dirty_submodule = tmp;
+		SWAP(old_dirty_submodule, new_dirty_submodule);
 	}
 
 	if (options->prefix &&