Re: [PATCH v2 03/44] qdev: Use returned bool to check for qdev_realize() etc. failure

[Vladimir Sementsov-Ogievskiy]

02.07.2020 18:49, Markus Armbruster wrote:
> Convert
>
>      foo(..., &err);
>      if (err) {
>          ...
>      }
>
> to
>
>      if (!foo(..., &err)) {
>          ...
>      }
>
> for qdev_realize(), qdev_realize_and_unref(), qbus_realize() and their
> wrappers isa_realize_and_unref(), pci_realize_and_unref(),
> sysbus_realize(), sysbus_realize_and_unref(), usb_realize_and_unref().
> Coccinelle script:
>
>      @@
>      identifier fun = {isa_realize_and_unref, pci_realize_and_unref, 
> qbus_realize, qdev_realize, qdev_realize_and_unref, sysbus_realize, 
> sysbus_realize_and_unref, usb_realize_and_unref};
>      expression list args, args2;
>      typedef Error;
>      Error *err;
>      @@
>      -    fun(args, &err, args2);
>      -    if (err)
>      +    if (!fun(args, &err, args2))
>           {
>               ...
>           }
>
> Chokes on hw/arm/musicpal.c's lcd_refresh() with the unhelpful error
> message "no position information".  Nothing to convert there; skipped.
>
> Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by
> ARMSSE being used both as typedef and function-like macro there.
> Converted manually.
>
> A few line breaks tidied up manually.
>
> Signed-off-by: Markus Armbruster<armbru@redhat.com>


Sorry me, reviewing this patch with help of script:
#!/usr/bin/env python3

import sys
import re

with open(sys.argv[1]) as f:
    patch = f.read()

regex = re.compile(r'^- *(?P<func_call>(?P<func>\w+)\(.*, &(?P<err>\w+)\));\n'
                   r'^- *if \((?P=err)( != NULL)?\) \{\n'
                   r'^\+ *if \(!(?P=func_call)\) \{$', flags=re.MULTILINE)

for chunk in re.split('^@', patch, flags=re.MULTILINE):
    filtered = regex.sub('OK', chunk)

    if re.search('^[+-][^+-]', filtered, flags=re.MULTILINE):
        print(re.sub('^', '   ', '@' + chunk, flags=re.MULTILINE))


funcs = set()

for m in regex.finditer(patch):
    funcs.add(m.group('func'))

print()
for func in funcs:
    print(func)


====
output:

   @@ -34,9 +34,7 @@ static void virtio_gpu_pci_base_realize(VirtIOPCIProxy 
*vpci_dev, Error **errp)
        Error *local_error = NULL;
    
        virtio_pci_force_virtio_1(vpci_dev);
   -    qdev_realize(vdev, BUS(&vpci_dev->bus), &local_error);
   -
   -    if (local_error) {
   +    if (!qdev_realize(vdev, BUS(&vpci_dev->bus), &local_error)) {
            error_propagate(errp, local_error);
            return;
        }
   diff --git a/hw/display/virtio-vga.c b/hw/display/virtio-vga.c
   index 67f409e106..0fc00fee1f 100644
   --- a/hw/display/virtio-vga.c
   +++ b/hw/display/virtio-vga.c
   
   @@ -444,15 +444,13 @@ static void realize_event_facility(DeviceState *dev, Error **errp)
        SCLPEventFacility *event_facility = EVENT_FACILITY(dev);
        Error *local_err = NULL;
    
   -    qdev_realize(DEVICE(&event_facility->quiesce),
   -                 BUS(&event_facility->sbus), &local_err);
   -    if (local_err) {
   +    if (!qdev_realize(DEVICE(&event_facility->quiesce),
   +                      BUS(&event_facility->sbus), &local_err)) {
            error_propagate(errp, local_err);
            return;
        }
   -    qdev_realize(DEVICE(&event_facility->cpu_hotplug),
   -                 BUS(&event_facility->sbus), &local_err);
   -    if (local_err) {
   +    if (!qdev_realize(DEVICE(&event_facility->cpu_hotplug),
   +                      BUS(&event_facility->sbus), &local_err)) {
            error_propagate(errp, local_err);
            qdev_unrealize(DEVICE(&event_facility->quiesce));
            return;
   diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
   index 142e52a8ff..0517901024 100644
   --- a/hw/s390x/s390-pci-bus.c
   +++ b/hw/s390x/s390-pci-bus.c
   

usb_realize_and_unref
sysbus_realize
sysbus_realize_and_unref
qdev_realize
qdev_realize_and_unref

===

So, the remaning non-matching seems correct, and all found functions seems to 
have corresponding semantics:

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

--
Best regards,
Vladimir