Re: [PATCH v2 35/44] error: Eliminate error_propagate() with Coccinelle, part 2
Eric Blake writes:
> On 7/2/20 10:49 AM, Markus Armbruster wrote:
>> When all we do with an Error we receive into a local variable is
>> propagating to somewhere else, we can just as well receive it there
>> right away. The previous commit did that with a Coccinelle script I
>> consider fairly trustworthy. This commit uses the same script with
>> the matching of return taken out, i.e. we convert
>>
>> if (!foo(..., )) {
>> ...
>> error_propagate(errp, err);
>> ...
>> }
>>
>> to
>>
>> if (!foo(..., errp)) {
>> ...
>> ...
>> }
>>
>> This is unsound: @err could still be read between afterwards. I don't
>> know how to express "no read of @err without an intervening write" in
>> Coccinelle. Instead, I manually double-checked for uses of @err.
>>
>> Suboptimal line breaks tweaked manually. qdev_realize() simplified
>> further to placate scripts/checkpatch.pl.
>>
>> Signed-off-by: Markus Armbruster
>> ---
>> block.c | 6 ++
>> block/blkdebug.c | 7 ++-
>> block/blklogwrites.c | 3 +--
>> block/blkverify.c| 3 +--
>> block/crypto.c | 4 +---
>> block/file-posix.c | 6 ++
>> block/file-win32.c | 6 ++
>> block/gluster.c | 4 +---
>> block/iscsi.c| 3 +--
>> block/nbd.c | 8 ++--
>> block/qcow2.c| 13 -
>> block/raw-format.c | 4 +---
>> block/sheepdog.c | 8 ++--
>> block/ssh.c | 4 +---
>> block/throttle.c | 4 +---
>> block/vmdk.c | 4 +---
>> block/vpc.c | 3 +--
>> block/vvfat.c| 3 +--
>> blockdev.c | 3 +--
>> hw/intc/xics.c | 4 +---
>> hw/vfio/pci.c| 3 +--
>> net/tap.c| 3 +--
>> qom/object.c | 4 +---
>> 23 files changed, 32 insertions(+), 78 deletions(-)
>
> Small enough to review each instance.
>
> Reviewed-by: Eric Blake
I tried *really* hard to make part 1's script powerful and safe, to give
the unsafe / manual parts (this commit and next) a chance of meaningful
review. Thanks for providing it!
Re: [PATCH v2 35/44] error: Eliminate error_propagate() with Coccinelle, part 2
On 7/2/20 10:49 AM, Markus Armbruster wrote:
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away. The previous commit did that with a Coccinelle script I
consider fairly trustworthy. This commit uses the same script with
the matching of return taken out, i.e. we convert
if (!foo(..., )) {
...
error_propagate(errp, err);
...
}
to
if (!foo(..., errp)) {
...
...
}
This is unsound: @err could still be read between afterwards. I don't
know how to express "no read of @err without an intervening write" in
Coccinelle. Instead, I manually double-checked for uses of @err.
Suboptimal line breaks tweaked manually. qdev_realize() simplified
further to placate scripts/checkpatch.pl.
Signed-off-by: Markus Armbruster
---
block.c | 6 ++
block/blkdebug.c | 7 ++-
block/blklogwrites.c | 3 +--
block/blkverify.c| 3 +--
block/crypto.c | 4 +---
block/file-posix.c | 6 ++
block/file-win32.c | 6 ++
block/gluster.c | 4 +---
block/iscsi.c| 3 +--
block/nbd.c | 8 ++--
block/qcow2.c| 13 -
block/raw-format.c | 4 +---
block/sheepdog.c | 8 ++--
block/ssh.c | 4 +---
block/throttle.c | 4 +---
block/vmdk.c | 4 +---
block/vpc.c | 3 +--
block/vvfat.c| 3 +--
blockdev.c | 3 +--
hw/intc/xics.c | 4 +---
hw/vfio/pci.c| 3 +--
net/tap.c| 3 +--
qom/object.c | 4 +---
23 files changed, 32 insertions(+), 78 deletions(-)
Small enough to review each instance.
Reviewed-by: Eric Blake
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
