diff mbox series

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

Message ID 20200226084647.20636-2-kuhn.chenqun@huawei.com (mailing list archive)
State New, archived
Headers show
Series redundant code: Fix warnings reported by Clang static code analyzer | expand

Commit Message

Chen Qun Feb. 26, 2020, 8:46 a.m. UTC 
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>
---
Cc: John Snow <jsnow@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
---
 block/stream.c | 1 -
 1 file changed, 1 deletion(-)

Comments

Kevin Wolf Feb. 26, 2020, 9:51 a.m. UTC | #1 
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.

With or without the changes:

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Chen Qun Feb. 26, 2020, 10:21 a.m. UTC | #2 
>-----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：
@@ -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>
Kevin Wolf Feb. 26, 2020, 10:36 a.m. UTC | #3 
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>
>
Chen Qun Feb. 26, 2020, 10:41 a.m. UTC | #4 
>-----Original Message-----
>From: Kevin Wolf [mailto:kwolf@redhat.com]
>Sent: Wednesday, February 26, 2020 6:36 PM
>To: Chenqun (kuhn) <kuhn.chenqun@huawei.com>
>Cc: John Snow <jsnow@redhat.com>; qemu-devel@nongnu.org; qemu-
>trivial@nongnu.org; peter.maydell@linaro.org; Zhanghailiang
><zhang.zhanghailiang@huawei.com>; Euler Robot
><euler.robot@huawei.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 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.
OK, no problem！

Thanks.
>
>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>
>>
diff mbox series

Patch

diff --git a/block/stream.c b/block/stream.c
index 5562ccbf57..d78074ac80 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -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);