Re: [PATCH] x86/pci: Add missing forward declaration for pci_numachip_init()

[Thomas Gleixner <tglx@linutronix.de>]

On Fri, Jul 30 2021 at 16:19, Bjorn Helgaas wrote:
> On Thu, Jul 29, 2021 at 11:40:59PM +0000, Krzysztof Wilczyński wrote:
> What should be done with the pci_numachip_init() declaration in
> arch/x86/include/asm/numachip/numachip.h?  It doesn't seem like we
> should have *two* declarations.

Right. Include that file in the C file and be done with it.

> The one in arch/x86/include/asm/numachip/numachip.h is:
>
>   extern int __init pci_numachip_init(void);
>
> I'm not enough of a C language lawyer to know whether "__init" in a
> declaration is useful.  It doesn't *seem* like it would be useful
> since this is not a definition and the compiler isn't generating code
> here.  But "git grep __init include/ arch/*/include" finds quite a few
> of them.

__init on the prototype is not having any effect except perhaps
documentary value at least with current compilers.

The attribute magic is vague in both the C specification and the
compiler manuals, but that might change some day in the future. But in
which direction is unknown :)

Thanks,

        tglx