strange code in linux kernel

Hi List,

I found that there are some weird looking instances in kernel where a
function has been DEFINED (as opposite to DECLARED) using and "extern"
keyword. For e.g., the following code in arch/alpha/include/asm/io.h:

extern inline void __iomem *generic_ioportmap(unsigned long a)
{
return alpha_mv.mv_ioportmap(a);
}

Using a definition along with extern does not make any sense to me.
Can some one please enlighten what is its use / purpose?

Thanks,

Rajat Jain

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Re: strange code in linux kernel

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Rajat Jain writes:
> I found that there are some weird looking instances in kernel where a
> function has been DEFINED (as opposite to DECLARED) using and "extern"
> keyword. For e.g., the following code in arch/alpha/include/asm/io.h:
>
> extern inline void __iomem *generic_ioportmap(unsigned long a)
> {
> return alpha_mv.mv_ioportmap(a);
> }
>
> Using a definition along with extern does not make any sense to me.
> Can some one please enlighten what is its use / purpose?

Note that at the same time an "inline" keyword has been used. You might
want to refer to GCC's documentation in particular
for more information.
Google also pointed to this site
which also might
have some insight.

=2D-=20
Best regards, _ _
.o. | Liege of Serenly Enlightened Majesty of o' \,=3D./ `o
..o | Computer Science, Michal "mina86" Nazarewicz (o o)
ooo +------ooO--(_)--Ooo--

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