Re: if(function()) BUG(); still bad?

[Roel Kluin <12o3l@tiscali.nl>]

Matthew Wilcox wrote:
> On Mon, Dec 03, 2007 at 01:20:20AM +0100, Roel Kluin wrote:
>> for instance in a patch I saw this:
>>
>>> +		if (__blk_end_request(rq, 0, 0))
>>> +			BUG();
>>>  		spin_unlock(q->queue_lock);
>> If it's still bad, what should the fix be? (I'll write a script and post
>> patches)
> 
> This one should not be converted to a BUG_ON.  We always want to call
> __blk_end_request(), whether we have CONFIG_BUG or not.  This case just
> wants to test the return value.
> 

Ok, from your reply I can make up it's bad if the function in the if()
assigns a value, or has pointers as arguments, which it modifies.