Re: [XEN PATCH v2 1/3] drivers: char: address violation of MISRA C Rule 20.7

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Tue, 30 Apr 2024, Nicola Vetrini wrote:
> MISRA C Rule 20.7 states: "Expressions resulting from the expansion
> of macro parameters shall be enclosed in parentheses". Therefore, some
> macro definitions should gain additional parentheses to ensure that all
> current and future users will be safe with respect to expansions that
> can possibly alter the semantics of the passed-in macro parameter.
> 
> No functional chage.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
> Changes in v2:
> - drop excess parentheses from val parameter.
> ---
>  xen/drivers/char/omap-uart.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/drivers/char/omap-uart.c b/xen/drivers/char/omap-uart.c
> index 03b5b66e7acb..e0128225f927 100644
> --- a/xen/drivers/char/omap-uart.c
> +++ b/xen/drivers/char/omap-uart.c
> @@ -48,8 +48,9 @@
>  /* System configuration register */
>  #define UART_OMAP_SYSC_DEF_CONF   0x0d   /* autoidle mode, wakeup is enabled 
> */
>  
> -#define omap_read(uart, off)       readl((uart)->regs + (off<<REG_SHIFT))
> -#define omap_write(uart, off, val) writel((val), (uart)->regs + 
> (off<<REG_SHIFT))
> +#define omap_read(uart, off)       readl((uart)->regs + ((off) << REG_SHIFT))
> +#define omap_write(uart, off, val) writel(val, (uart)->regs + \
> +                                               ((off) << REG_SHIFT))

the alignment looks off but could be fixed on commit


>  static struct omap_uart {
>      u32 baud, clock_hz, data_bits, parity, stop_bits, fifo_size;