Re: [PATCH v2 01/13] block/stream: Remove redundant statement in stream_run()

[Kevin Wolf <kwolf@redhat.com>]

Am 26.02.2020 um 11:21 hat Chenqun (kuhn) geschrieben:
> 
> 
> >-----Original Message-----
> >From: Kevin Wolf [mailto:kwolf@redhat.com]
> >Sent: Wednesday, February 26, 2020 5:51 PM
> >To: Chenqun (kuhn) <kuhn.chenqun@huawei.com>
> >Cc: qemu-devel@nongnu.org; qemu-trivial@nongnu.org;
> >peter.maydell@linaro.org; Zhanghailiang <zhang.zhanghailiang@huawei.com>;
> >Euler Robot <euler.robot@huawei.com>; John Snow <jsnow@redhat.com>;
> >Max Reitz <mreitz@redhat.com>
> >Subject: Re: [PATCH v2 01/13] block/stream: Remove redundant statement in
> >stream_run()
> >
> >Am 26.02.2020 um 09:46 hat kuhn.chenqun@huawei.com geschrieben:
> >> From: Chen Qun <kuhn.chenqun@huawei.com>
> >>
> >> Clang static code analyzer show warning:
> >>   block/stream.c:186:9: warning: Value stored to 'ret' is never read
> >>         ret = 0;
> >>         ^     ~
> >> Reported-by: Euler Robot <euler.robot@huawei.com>
> >> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
> >> Reviewed-by: John Snow <jsnow@redhat.com>
> >
> >Let's mention that this is unnecessary since commit 1d809098aa9.
> >
> >Since the same commit, the initialisation 'int ret = 0;' is unnecessary because
> >we never read ret before overwriting the initial value. We could clean this up
> >in the same patch.
> 
> Yes, we can clean it and move 'ret'  declaration to the for() statement.
> 
> Modify just Like this：
> [...]

Godd point, makes sense to me. Please keep my R-b if you make this
change.

Kevin

> @@ -114,7 +114,6 @@ static int coroutine_fn stream_run(Job *job, Error **errp)
>      int64_t offset = 0;
>      uint64_t delay_ns = 0;
>      int error = 0;
> -    int ret = 0;
>      int64_t n = 0; /* bytes */
> 
>      if (bs == s->bottom) {
> @@ -139,6 +138,7 @@ static int coroutine_fn stream_run(Job *job, Error **errp)
> 
>      for ( ; offset < len; offset += n) {
>          bool copy;
> +        int ret;
> 
>          /* Note that even when no rate limit is applied we need to yield
>           * with no pending I/O here so that bdrv_drain_all() returns.
> @@ -183,7 +183,6 @@ static int coroutine_fn stream_run(Job *job, Error **errp)
>                  break;
>              }
>          }
> -        ret = 0;
> 
>          /* Publish progress */
>          job_progress_update(&s->common.job, n);
> 
> >
> >With or without the changes:
> >
> >Reviewed-by: Kevin Wolf <kwolf@redhat.com>
>