On Fri, Jul 22, 2016 at 12:44:30PM +0200, Marek Polacek wrote:
> ...and the boring part. It found a few bugs, e.g. in jcf-dump.c
> and rs6000.c - I fixed those.
>
> I think generally it's better to use the attribute rather than a falls
> through comment, because the latter can't be followed by other comment
> or a macro to work.
The comment has the advantage (at least if it is some well standardized one)
that lint/coverity and other tools already understand it. So I think using
the comment in the cases where it really is immediately before case/default
is better.
> @@ -32335,6 +32341,7 @@ rs6000_handle_altivec_attribute (tree *node,
> case V4SImode: case V8HImode: case V16QImode: case V4SFmode:
> case V2DImode: case V2DFmode:
> result = type;
> + gcc_fallthrough ();
> default: break;
> }
> break;
> @@ -32345,6 +32352,7 @@ rs6000_handle_altivec_attribute (tree *node,
> case SImode: case V4SImode: result = bool_V4SI_type_node; break;
> case HImode: case V8HImode: result = bool_V8HI_type_node; break;
> case QImode: case V16QImode: result = bool_V16QI_type_node;
> + gcc_fallthrough ();
> default: break;
> }
> break;
> @@ -32352,6 +32360,7 @@ rs6000_handle_altivec_attribute (tree *node,
> switch (mode)
> {
> case V8HImode: result = pixel_V8HI_type_node;
> + gcc_fallthrough ();
> default: break;
> }
> default: break;
I thought we don't warn on these anymore?
Also, as others said, I think it would be best to split this patch into:
1) bugfixes part (where you've added break; that was missing and it changes
(fixes) behavior)
2) questionable cases (your XX), with request for the corresponding
maintainers to decide
3) the actual addition of the attribute/comments or tweaking their wording,
so that for intentional fallthrus we don't warn
Jakub
