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Date:   Mon, 8 Feb 2021 19:45:03 +0300
From:   Alexey Dobriyan <adobriyan@gmail.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] sched: make struct task_struct::state 32-bit
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On Mon, Feb 08, 2021 at 04:25:35PM +0100, Peter Zijlstra wrote:
> On Mon, Feb 08, 2021 at 05:52:45PM +0300, Alexey Dobriyan wrote:
> > On Mon, Feb 08, 2021 at 05:30:25PM +0300, Alexey Dobriyan wrote:
> > > On Mon, Feb 08, 2021 at 11:34:18AM +0100, Peter Zijlstra wrote:
> > > > On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> > > > 
> > > > > Silently delete "extern" from prototypes.
> > > > 
> > > > NAK, extern is right.
> > > 
> > > Extern is only necessary for variables.
> > 
> > Specifically C17, 6.2.2 p5 (linkage of identifiers):
> > 
> > 	if the declaration of an identifier for a function has no
> > 	storage-class specifier, its linkage is determined exactly as if
> > 	it were declared with the storage-class specifier "extern".
> > 
> > This is why nothing happens if "extern" is deleted.
> 
> I know, but I still very much like extern on the function declarations
> too. It tells me the definition isn't to be found in this TU.

What can I say. The absense of function body should tell that.