Re: [Qemu-devel] [PATCH] pci: Set err to errp directly rather than through error_porpagate()

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 26 May 2017 16:29:25 +0800
Mao Zhongyi <maozy.fnst@cn.fujitsu.com> wrote:

> ioh3420_interrupts_init() and its callers, rp_realize() and
> pci_qdev_realize() fill error message to local_err, then
> propagate it to errp by error_porpagate(), which's not necessary.
> So eliminate it and pass errp directly instead of local_err.
> Of course, error_propagate() also will be removed.
> 
> Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com>
> ---
[...]

> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 98ccc27..0d4a3ff 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1982,7 +1982,6 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>  {
>      PCIDevice *pci_dev = (PCIDevice *)qdev;
>      PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(pci_dev);
> -    Error *local_err = NULL;
>      PCIBus *bus;
>      bool is_default_rom;
>  
> @@ -1999,9 +1998,8 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>          return;
>  
>      if (pc->realize) {
> -        pc->realize(pci_dev, &local_err);
> -        if (local_err) {
> -            error_propagate(errp, local_err);
> +        pc->realize(pci_dev, errp);
> +        if (errp && *errp) {
>              do_pci_unregister_device(pci_dev);
>              return;
>          }
> @@ -2014,9 +2012,8 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
>          is_default_rom = true;
>      }
>  
> -    pci_add_option_rom(pci_dev, is_default_rom, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +    pci_add_option_rom(pci_dev, is_default_rom, errp);
> +    if (errp && *errp) {
>          pci_qdev_unrealize(DEVICE(pci_dev), NULL);
>          return;
>      }

dropping local_error here looks wrong since it's used
to check error status inside these functions and to undo
side effects in case of failure.

consider if caller pass errp = NULL
then error handling path won't be executed.

So keep the rest of the patch but drop above hunks.