On 3/20/19 2:24 PM, Bjorn Helgaas wrote:
> On Wed, Mar 20, 2019 at 01:27:15PM -0500, Gustavo A. R. Silva wrote:
>> In preparation to enabling -Wimplicit-fallthrough, mark switch
>> cases where we are expecting to fall through.
>
> Does this fix all the remaining cases in drivers/pci? I'd like to fix
> them all at once.
>
These are actually the last ones.
> What's the best way to watch for new warnings being added? I fiddled
> with "make W=2" etc but it didn't seem useful. Does the 0-day robot
> warn when -Wimplicit-fallthrough warnings are added?
>
0-day robot doesn't know about these warnings yet. But it certainly
will once we finally enable -Wimplicit-fallthrough.
Add this to your Makefile to see the warnings:
KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=3,)
Thanks
--
Gustavo
> Bjorn
>
>> This patch fixes the following warnings:
>>
>> drivers/pci/proc.c: In function ‘proc_bus_pci_ioctl’:
>> drivers/pci/proc.c:216:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>> if (arch_can_pci_mmap_wc()) {
>> ^
>> drivers/pci/proc.c:225:2: note: here
>> default:
>> ^~~~~~~
>>
>> drivers/pci/xen-pcifront.c: In function ‘pcifront_backend_changed’:
>> drivers/pci/xen-pcifront.c:1105:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>> if (xdev->state == XenbusStateClosed)
>> ^
>> drivers/pci/xen-pcifront.c:1108:2: note: here
>> case XenbusStateClosing:
>> ^~~~
>>
>> Notice that, in this particular case, the /* fall through */
>> comment is placed at the very bottom of the case statement,
>> which is what GCC is expecting to find.
>>
>> Warning level 3 was used: -Wimplicit-fallthrough=3
>>
>> This patch is part of the ongoing efforts to enable
>> -Wimplicit-fallthrough.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
>> ---
>> drivers/pci/proc.c | 1 +
>> drivers/pci/xen-pcifront.c | 2 +-
>> 2 files changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
>> index 6fa1627ce08d..445b51db75b0 100644
>> --- a/drivers/pci/proc.c
>> +++ b/drivers/pci/proc.c
>> @@ -222,6 +222,7 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
>> }
>> /* If arch decided it can't, fall through... */
>> #endif /* HAVE_PCI_MMAP */
>> + /* fall through */
>> default:
>> ret = -EINVAL;
>> break;
>> diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
>> index eba6e33147a2..14cf0f41ecf0 100644
>> --- a/drivers/pci/xen-pcifront.c
>> +++ b/drivers/pci/xen-pcifront.c
>> @@ -1104,7 +1104,7 @@ static void __ref pcifront_backend_changed(struct xenbus_device *xdev,
>> case XenbusStateClosed:
>> if (xdev->state == XenbusStateClosed)
>> break;
>> - /* Missed the backend's CLOSING state -- fallthrough */
>> + /* fall through - Missed the backend's CLOSING state. */
>> case XenbusStateClosing:
>> dev_warn(&xdev->dev, "backend going away!\n");
>> pcifront_try_disconnect(pdev);
>> --
>> 2.21.0
>>
