[PATCH] xen: mark expected switch fall-through

[PATCH] xen: mark expected switch fall-through

[Gustavo A. R. Silva]

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warning:

drivers/xen/xen-pciback/xenbus.c: In function ‘xen_pcibk_frontend_changed’:
drivers/xen/xen-pciback/xenbus.c:545:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (xenbus_dev_is_online(xdev))
      ^
drivers/xen/xen-pciback/xenbus.c:548:2: note: here
  case XenbusStateUnknown:
  ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

Notice that, in this particular case, the code comment is modified
in accordance with what GCC is expecting to find.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/xen/xen-pciback/xenbus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 581c4e1a8b82..23f7f6ec7d1f 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -544,7 +544,7 @@ static void xen_pcibk_frontend_changed(struct xenbus_device *xdev,
 		xenbus_switch_state(xdev, XenbusStateClosed);
 		if (xenbus_dev_is_online(xdev))
 			break;
-		/* fall through if not online */
+		/* fall through - if not online */
 	case XenbusStateUnknown:
 		dev_dbg(&xdev->dev, "frontend is gone! unregister device\n");
 		device_unregister(&xdev->dev);
-- 
2.20.1

Re: [PATCH] xen: mark expected switch fall-through

[Boris Ostrovsky]

On Tue, Feb 12, 2019 at 02:37:20PM -0600, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch
> cases where we are expecting to fall through.
> 
> This patch fixes the following warning:
> 
> drivers/xen/xen-pciback/xenbus.c: In function ‘xen_pcibk_frontend_changed’:
> drivers/xen/xen-pciback/xenbus.c:545:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    if (xenbus_dev_is_online(xdev))
>       ^
> drivers/xen/xen-pciback/xenbus.c:548:2: note: here
>   case XenbusStateUnknown:
>   ^~~~
> 
> Warning level 3 was used: -Wimplicit-fallthrough=3
> 
> Notice that, in this particular case, the code comment is modified
> in accordance with what GCC is expecting to find.
> 
> This patch is part of the ongoing efforts to enable
> -Wimplicit-fallthrough.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Applied to for-linus-5.0

(xen-scsiback patch too)

-boris

Re: [PATCH] xen: mark expected switch fall-through

[Gustavo A. R. Silva]

On 2/12/19 5:50 PM, Boris Ostrovsky wrote:
> On Tue, Feb 12, 2019 at 02:37:20PM -0600, Gustavo A. R. Silva wrote:
>> In preparation to enabling -Wimplicit-fallthrough, mark switch
>> cases where we are expecting to fall through.
>>
>> This patch fixes the following warning:
>>
>> drivers/xen/xen-pciback/xenbus.c: In function ‘xen_pcibk_frontend_changed’:
>> drivers/xen/xen-pciback/xenbus.c:545:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>    if (xenbus_dev_is_online(xdev))
>>       ^
>> drivers/xen/xen-pciback/xenbus.c:548:2: note: here
>>   case XenbusStateUnknown:
>>   ^~~~
>>
>> Warning level 3 was used: -Wimplicit-fallthrough=3
>>
>> Notice that, in this particular case, the code comment is modified
>> in accordance with what GCC is expecting to find.
>>
>> This patch is part of the ongoing efforts to enable
>> -Wimplicit-fallthrough.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> 
> Applied to for-linus-5.0
> 
> (xen-scsiback patch too)
> 

Thank you, Boris.

--
Gustavo

Re: [PATCH] xen: mark expected switch fall-through

[Juergen Gross]

On 13/02/2019 00:50, Boris Ostrovsky wrote:
> On Tue, Feb 12, 2019 at 02:37:20PM -0600, Gustavo A. R. Silva wrote:
>> In preparation to enabling -Wimplicit-fallthrough, mark switch
>> cases where we are expecting to fall through.
>>
>> This patch fixes the following warning:
>>
>> drivers/xen/xen-pciback/xenbus.c: In function ‘xen_pcibk_frontend_changed’:
>> drivers/xen/xen-pciback/xenbus.c:545:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>    if (xenbus_dev_is_online(xdev))
>>       ^
>> drivers/xen/xen-pciback/xenbus.c:548:2: note: here
>>   case XenbusStateUnknown:
>>   ^~~~
>>
>> Warning level 3 was used: -Wimplicit-fallthrough=3
>>
>> Notice that, in this particular case, the code comment is modified
>> in accordance with what GCC is expecting to find.
>>
>> This patch is part of the ongoing efforts to enable
>> -Wimplicit-fallthrough.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> 
> Applied to for-linus-5.0
> 
> (xen-scsiback patch too)

I'm tending to delay those patches until 5.1, as we are pretty late in
the 5.0 cycle. We should add only really critical fixes to 5.0 now.


Juergen