Re: [XEN PATCH 05/11] drivers/pci: move variable definitions to address MISRA C:2012 Rule 2.1

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 2 Aug 2023, Nicola Vetrini wrote:
> Variable declarations between a switch statement guard and before
> any case label are unreachable code, and hence violate Rule 2.1:
> "A project shall not contain unreachable code".
> 
> Therefore the variable declarations are moved in the smallest enclosing
> scope, near other variable definitions.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
> ---
>  xen/drivers/passthrough/pci.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
> index 33452791a8..3f5fa5beef 100644
> --- a/xen/drivers/passthrough/pci.c
> +++ b/xen/drivers/passthrough/pci.c
> @@ -315,6 +315,7 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, 
> u8 bus, u8 devfn)
>      struct pci_dev *pdev;
>      unsigned int pos;
>      int rc;
> +    unsigned int cap, sec_bus, sub_bus;
>  
>      list_for_each_entry ( pdev, &pseg->alldevs_list, alldevs_list )
>          if ( pdev->bus == bus && pdev->devfn == devfn )
> @@ -343,8 +344,6 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, 
> u8 bus, u8 devfn)
>      /* update bus2bridge */
>      switch ( pdev->type = pdev_type(pseg->nr, bus, devfn) )
>      {
> -        unsigned int cap, sec_bus, sub_bus;

sub_bus and sec_bus could go under case DEV_TYPE_LEGACY_PCI_BRIDGE
cap could go under case DEV_TYPE_PCIe_ENDPOINT


>          case DEV_TYPE_PCIe2PCI_BRIDGE:
>          case DEV_TYPE_LEGACY_PCI_BRIDGE:
>              sec_bus = pci_conf_read8(pdev->sbdf, PCI_SECONDARY_BUS);
> @@ -424,11 +423,11 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, 
> u8 bus, u8 devfn)
>  
>  static void free_pdev(struct pci_seg *pseg, struct pci_dev *pdev)
>  {
> +    unsigned int sec_bus, sub_bus;
> +
>      /* update bus2bridge */
>      switch ( pdev->type )
>      {
> -        unsigned int sec_bus, sub_bus;

They could go under case DEV_TYPE_LEGACY_PCI_BRIDGE


>          case DEV_TYPE_PCIe2PCI_BRIDGE:
>          case DEV_TYPE_LEGACY_PCI_BRIDGE:
>              sec_bus = pci_conf_read8(pdev->sbdf, PCI_SECONDARY_BUS);
> @@ -1555,11 +1554,10 @@ int iommu_do_pci_domctl(
>      u8 bus, devfn;
>      int ret = 0;
>      uint32_t machine_sbdf;
> +    unsigned int flags;
>  
>      switch ( domctl->cmd )
>      {
> -        unsigned int flags;

it could go under case XEN_DOMCTL_test_assign_device


>      case XEN_DOMCTL_get_device_group:
>      {
>          u32 max_sdevs;
> -- 
> 2.34.1
>