2018-06-07 20:07:04

by Corentin LABBE

Subject: [PATCH] usb: Replace empty define with do while

It's dangerous to use empty code define.
Furthermore it lead to the following warning:
"suggest braces around empty body in an « else » statement"

So let's replace emptyness by "do {} while(0)"

Signed-off-by: Corentin Labbe <[email protected]>
---
drivers/usb/host/ehci.h | 2 +-
drivers/usb/host/fotg210.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index c8e9a48e1d51..a60d91eac771 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -237,7 +237,7 @@ struct ehci_hcd { /* one per controller */
struct ehci_stats stats;
# define COUNT(x) ((x)++)
#else
-# define COUNT(x)
+# define COUNT(x) do {} while (0)
#endif

/* debug files */
diff --git a/drivers/usb/host/fotg210.h b/drivers/usb/host/fotg210.h
index 7fcd785c7bc8..dca46d04e288 100644
--- a/drivers/usb/host/fotg210.h
+++ b/drivers/usb/host/fotg210.h
@@ -179,7 +179,7 @@ struct fotg210_hcd { /* one per controller */
struct fotg210_stats stats;
# define COUNT(x) ((x)++)
#else
-# define COUNT(x)
+# define COUNT(x) do {} while (0)
#endif

/* debug files */
--
2.16.4

2018-06-07 20:18:02

by Joe Perches

Subject: Re: [PATCH] usb: Replace empty define with do while

On Thu, 2018-06-07 at 20:05 +0000, Corentin Labbe wrote:
> It's dangerous to use empty code define.
> Furthermore it lead to the following warning:
> "suggest braces around empty body in an ? else ? statement"
>
> So let's replace emptyness by "do {} while(0)"

I also suggest renaming COUNT to something more
intelligible like INCR as the uses are all for
incrementing variables that may not exist.

> diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
> index c8e9a48e1d51..a60d91eac771 100644
> --- a/drivers/usb/host/ehci.h
> +++ b/drivers/usb/host/ehci.h
> @@ -237,7 +237,7 @@ struct ehci_hcd { /* one per controller */
> struct ehci_stats stats;
> # define COUNT(x) ((x)++)
> #else
> -# define COUNT(x)
> +# define COUNT(x) do {} while (0)
> #endif
>
> /* debug files */
> diff --git a/drivers/usb/host/fotg210.h b/drivers/usb/host/fotg210.h
> index 7fcd785c7bc8..dca46d04e288 100644
> --- a/drivers/usb/host/fotg210.h
> +++ b/drivers/usb/host/fotg210.h
> @@ -179,7 +179,7 @@ struct fotg210_hcd { /* one per controller */
> struct fotg210_stats stats;
> # define COUNT(x) ((x)++)
> #else
> -# define COUNT(x)
> +# define COUNT(x) do {} while (0)
> #endif
>
> /* debug files */