Re: [PATCH v2 35/44] error: Eliminate error_propagate() with Coccinelle, part 2

[Eric Blake <eblake@redhat.com>]

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(..., &err)) {
> 	...
> 	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 <armbru@redhat.com>
> ---
>   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 <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
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