Re: [patch 2/3] Add a WARN() macro; this is WARN_ON() + printk arguments

[Arjan van de Ven <arjan@infradead.org>]

On Wed, 7 May 2008 08:41:31 +0200
"Vegard Nossum" <vegard.nossum@gmail.com> wrote:

> Hi!
> 
> On Wed, May 7, 2008 at 8:21 AM, Arjan van de Ven
> <arjan@infradead.org> wrote:
> > Subject: Add a WARN() macro; this is WARN_ON() + printk arguments
> >  From: Arjan van de Ven <arjan@linux.intel.com>
> >
> >  Add a WARN() macro that acts like WARN_ON(), with the added
> > feature that it takes a printk like argument that is printed as
> > part of the warning message.
> 
> [...]
> 
> >  +#ifndef WARN
> >  +#define WARN(condition, format...)
> > ({                                          \
> >  +       int __ret_warn_on
> > = !!(condition);                              \
> >  +       if
> > (unlikely(__ret_warn_on))                                    \
> >  +
> > __WARN_printf(format);                                  \
> >  +
> > unlikely(__ret_warn_on);                                        \
> > +}) +#endif
> 
> Is there a good reason why this is not a static inline function? 

yes there is, and it's the same one that makes WARN_ON() not an inline
function (I tried); it's not possible to find a type for "condition"
that works for all callers.

> If WARN() is made a static inline, you can call
> __builtin_return_address(0) there and pass it into here instead. This
> seems like a kind of low-level internal function anyway, because of
> the file/line info.

if I could make it a static inline, I would make it an out of line
instead to save space ;)