Re: [PATCH] net: xfrm_user: use BUG_ON instead of if condition followed by BUG

[Herbert Xu]

On Tue, Oct 24, 2017 at 05:48:42PM +0900, David Miller wrote:
> 
> This discussion has happened before.
> 
> But I'll explain the conclusion here for your benefit.
> 
> BUG_ON() is a statement and everything inside of it will
> always execute.
> 
> BUG_ON() is always preferred because it allows arch
> specific code to pass the conditional result properly
> into inline asm and builtins for optimal code generation.

This is a good point.  However, while a little bit more verbose you
can still achieve the same assembly-level result by something like

	int err;

	err = <insert real code here>;
	BUG_ON(err);

Having real code in BUG_ON may pose problems to people reading the
code because some of us tend to ignore code in BUG_ON and similar
macros such as BUILD_BUG_ON.

Cheers,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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