[Patch] selinux: remove an unreachable line

[Patch] selinux: remove an unreachable line

[Amerigo Wang]

This line is unreachable, remove it.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Eric Paris <eparis@parisplace.org>


---
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index b5407f1..a2f1034 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -544,7 +544,6 @@ int mls_compute_sid(struct context *scontext,
 	default:
 		return -EINVAL;
 	}
-	return -EINVAL;
 }
 
 #ifdef CONFIG_NETLABEL

Re: [Patch] selinux: remove an unreachable line

[Joe Perches]

On Tue, 2009-12-01 at 02:41 -0500, Amerigo Wang wrote:
> This line is unreachable, remove it.
[]
> diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
> index b5407f1..a2f1034 100644
> --- a/security/selinux/ss/mls.c
> +++ b/security/selinux/ss/mls.c
> @@ -544,7 +544,6 @@ int mls_compute_sid(struct context *scontext,
>  	default:
>  		return -EINVAL;
>  	}
> -	return -EINVAL;
>  }

I think it's better to remove the default case.

Re: [Patch] selinux: remove an unreachable line

[Cong Wang]

Joe Perches wrote:
> On Tue, 2009-12-01 at 02:41 -0500, Amerigo Wang wrote:
>> This line is unreachable, remove it.
> []
>> diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
>> index b5407f1..a2f1034 100644
>> --- a/security/selinux/ss/mls.c
>> +++ b/security/selinux/ss/mls.c
>> @@ -544,7 +544,6 @@ int mls_compute_sid(struct context *scontext,
>>  	default:
>>  		return -EINVAL;
>>  	}
>> -	return -EINVAL;
>>  }
> 
> I think it's better to remove the default case.
> 

This is totally a personal taste, I think.
Either is OK. James, any comments?

Re: [Patch] selinux: remove an unreachable line

[James Morris]

On Tue, 1 Dec 2009, Cong Wang wrote:

> > >  	default:
> > >  		return -EINVAL;
> > >  	}
> > > -	return -EINVAL;
> > >  }
> > 
> > I think it's better to remove the default case.
> > 
> 
> This is totally a personal taste, I think.
> Either is OK. James, any comments?

Leave the default: there but with a comment /* fall through */
instead of the return.



-- 
James Morris
<jmorris@namei.org>

Re: [Patch] selinux: remove an unreachable line

[Dan Carpenter]

On Tue, Dec 01, 2009 at 04:31:36PM +0800, Cong Wang wrote:
> Joe Perches wrote:
>> On Tue, 2009-12-01 at 02:41 -0500, Amerigo Wang wrote:
>>> This line is unreachable, remove it.
>> []
>>> diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
>>> index b5407f1..a2f1034 100644
>>> --- a/security/selinux/ss/mls.c
>>> +++ b/security/selinux/ss/mls.c
>>> @@ -544,7 +544,6 @@ int mls_compute_sid(struct context *scontext,
>>>  	default:
>>>  		return -EINVAL;
>>>  	}
>>> -	return -EINVAL;
>>>  }
>>
>> I think it's better to remove the default case.
>>
>
> This is totally a personal taste, I think.
> Either is OK. James, any comments?

I think the last unreachable return might also stop certain
versions of gcc complaining about control reaching the end of
a non void function.

regards,
dan carpenter

Re: [Patch] selinux: remove an unreachable line

[Cong Wang]

James Morris wrote:
> On Tue, 1 Dec 2009, Cong Wang wrote:
> 
>>>>  	default:
>>>>  		return -EINVAL;
>>>>  	}
>>>> -	return -EINVAL;
>>>>  }
>>> I think it's better to remove the default case.
>>>
>> This is totally a personal taste, I think.
>> Either is OK. James, any comments?
> 
> Leave the default: there but with a comment /* fall through */
> instead of the return.
> 

Ok, will do, thanks.

Re: [Patch] selinux: remove an unreachable line

[Cong Wang]

Dan Carpenter wrote:
> On Tue, Dec 01, 2009 at 04:31:36PM +0800, Cong Wang wrote:
>> Joe Perches wrote:
>>> On Tue, 2009-12-01 at 02:41 -0500, Amerigo Wang wrote:
>>>> This line is unreachable, remove it.
>>> []
>>>> diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
>>>> index b5407f1..a2f1034 100644
>>>> --- a/security/selinux/ss/mls.c
>>>> +++ b/security/selinux/ss/mls.c
>>>> @@ -544,7 +544,6 @@ int mls_compute_sid(struct context *scontext,
>>>>  	default:
>>>>  		return -EINVAL;
>>>>  	}
>>>> -	return -EINVAL;
>>>>  }
>>> I think it's better to remove the default case.
>>>
>> This is totally a personal taste, I think.
>> Either is OK. James, any comments?
> 
> I think the last unreachable return might also stop certain
> versions of gcc complaining about control reaching the end of
> a non void function.

Hmm, aren't those version of gcc buggy? Here we have return values
in all cases of 'switch', it shouldn't complain...

Re: [Patch] selinux: remove an unreachable line

[Joe Perches]

On Thu, 2009-12-03 at 16:39 +0800, Cong Wang wrote:
> Dan Carpenter wrote:
> > On Tue, Dec 01, 2009 at 04:31:36PM +0800, Cong Wang wrote:
> >> Joe Perches wrote:
> >>> On Tue, 2009-12-01 at 02:41 -0500, Amerigo Wang wrote:
> >>>> This line is unreachable, remove it.
> >>> []
> >>>> diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
> >>>> index b5407f1..a2f1034 100644
> >>>> --- a/security/selinux/ss/mls.c
> >>>> +++ b/security/selinux/ss/mls.c
> >>>> @@ -544,7 +544,6 @@ int mls_compute_sid(struct context *scontext,
> >>>>  	default:
> >>>>  		return -EINVAL;
> >>>>  	}
> >>>> -	return -EINVAL;
> >>>>  }
> >>> I think it's better to remove the default case.
> >>>
> >> This is totally a personal taste, I think.
> >> Either is OK. James, any comments?
> > 
> > I think the last unreachable return might also stop certain
> > versions of gcc complaining about control reaching the end of
> > a non void function.
> 
> Hmm, aren't those version of gcc buggy? Here we have return values
> in all cases of 'switch', it shouldn't complain...

Various versions of gcc do complain.

It's also a bit counter-expectation to
the reader to find no return at the end
of a non-void function.

As a reader, you then have to scan the
cases to find the default: case which
isn't necessarily at the end.

If it is a simple
	default:
		return foo;

I think it less jarring to omit
default from the switch statement
and use
	return foo;
}

at the function exit.