checkpatch.pl: WARNING: else is not generally useful after a break or return
From: Luben Tuikov
Date: Fri Apr 17 2020 - 15:21:21 EST
Hi,
I'm getting what seems to be a false positive in this case:
:32: WARNING: else is not generally useful after a break or return
#32: FILE: drivers/gpu/drm/amd/amdgpu/amdgpu_job.c:55:
+ return 0;
+ } else {
for the following code, at the bottom of a function:
if (amdgpu_device_should_recover_gpu(ring->adev)) {
amdgpu_device_gpu_recover(ring->adev, job);
return 0;
} else {
drm_sched_suspend_timeout(&ring->sched);
return 1;
}
}
Which seems to be coming from commit:
commit 032a4c0f9a77ce565355c6e191553e853ba66f09
Author: Joe Perches <joe@xxxxxxxxxxx>
Date: Wed Aug 6 16:10:29 2014 -0700
checkpatch: warn on unnecessary else after return or break
Using an else following a break or return can unnecessarily indent code
blocks.
ie:
for (i = 0; i < 100; i++) {
int foo = bar();
if (foo < 1)
break;
else
usleep(1);
}
is generally better written as:
for (i = 0; i < 100; i++) {
int foo = bar();
if (foo < 1)
break;
usleep(1);
}
Warn when a bare else statement is preceded by a break or return
indented 1 tab more than the else.
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
While I agree with what the commit is trying to do,
it doesn't seem to apply to the if-else statement which I quoted
above. That is, the "else" is not "bare"--to use the lingo of
the commit.
I suggest that no warning is issued when the "else" is a compound
statement, as shown in my example at the top of this email.
It is only natural to write:
if (amdgpu_device_should_recover_gpu(ring->adev)) {
amdgpu_device_gpu_recover(ring->adev, job);
return 0;
} else {
drm_sched_suspend_timeout(&ring->sched);
return 1;
}
}
instead of,
if (amdgpu_device_should_recover_gpu(ring->adev)) {
amdgpu_device_gpu_recover(ring->adev, job);
return 0;
}
drm_sched_suspend_timeout(&ring->sched);
return 1;
}
Regards,
--
Luben