Re: [XEN PATCH 06/10] arm/smmu: address some violations of MISRA C Rule 20.7

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 29 Feb 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 change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
> ---
>  xen/drivers/passthrough/arm/smmu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/drivers/passthrough/arm/smmu.c 
> b/xen/drivers/passthrough/arm/smmu.c
> index 625ed0e41961..83196057a937 100644
> --- a/xen/drivers/passthrough/arm/smmu.c
> +++ b/xen/drivers/passthrough/arm/smmu.c
> @@ -242,7 +242,7 @@ struct arm_smmu_xen_device {
>       struct iommu_group *group;
>  };
>  
> -#define dev_archdata(dev) ((struct arm_smmu_xen_device *)dev->iommu)
> +#define dev_archdata(dev) ((struct arm_smmu_xen_device *)(dev)->iommu)
>  #define dev_iommu_domain(dev) (dev_archdata(dev)->domain)
>  #define dev_iommu_group(dev) (dev_archdata(dev)->group)

this is OK


> @@ -627,7 +627,7 @@ struct arm_smmu_master_cfg {
>  };
>  #define INVALID_SMENDX                       -1
>  #define for_each_cfg_sme(cfg, i, idx, num) \
> -     for (i = 0; idx = cfg->smendx[i], i < num; ++i)
> +     for (i = 0; idx = (cfg)->smendx[i], (i) < (num); ++(i))

The first i = 0 is missing parentheses?
Also idx misses parentheses?