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Date: Wed, 15 Oct 2014 12:50:00 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] checkpatch: Add error on use of attribute((weak))
 or __weak
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On Wed, 15 Oct 2014 12:45:48 -0700 Joe Perches <joe@perches.com> wrote:

> On Wed, 2014-10-15 at 12:42 -0700, Andrew Morton wrote:
> > On Wed, 15 Oct 2014 12:32:08 -0700 Joe Perches <joe@perches.com> wrote:
> > 
> > > Using weak can have unintended link defects.
> > > Emit an error on its use.
> > 
> > Well, we don't want a warning about use of __weak in function
> > definitions.  Only in declarations.
> 
> Why is that?

Because the problem we're trying to detect is when __weak is used on a
declaration.

This is OK:

foo.h:
extern int foo(void);
foo.c:
int __weak foo(void)
{
	...
}

But this is not OK:

foo.h:
extern __weak int foo(void);
foo.c:
int __weak foo(void)
{
	...
}