Re: PCI: Remove "extern" from function declarations

[Bjorn Helgaas]

On Wed, Apr 17, 2013 at 5:24 PM, Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> Hi Bjorn,
>
> I just noticed this commit (f39d5b72913e "PCI: Remove "extern" from
> function declarations") in the pci next branch.  Just wondering why you
> would do such a thing.  It is a lot of churn in quite a few header files
> and (in my opinion) goes the wrong way anyway.
>
> It may not actually make any difference to the compiler for functions, but
> for variables, it does.   A variable declared in a header file without
> "extern" will effectively define it in every compilation that includes
> the header file, one with "extern" will only produce references.
>
> So, since, the global variables really should have the "extern", the
> functions are now inconsistent with that.
>
> It also means that when someone copies a function declaration to make a
> "static inline" stub, the "extern" is a big hint for them to remember to
> make the stub "static" - I have seen several occasions when this was not
> done and that causes compilation failures (but usually only in the
> configuration that the author did not bother to test).

Good points.  The fact that some function declarations use "extern"
and some don't is just an annoying inconsistency.  I prefer fewer
words to read, so I removed them, but that's just a personal
preference, and I'd be OK it were always present, too.  I suppose if
anybody but me actually cared very much, we'd have checkpatch complain
about one way or the other, but I don't think it does.

Bjorn
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