Re: [PATCH 2/3] checkpatch: Add error on use of attribute((weak)) or __weak

[Andrew Morton <akpm@linux-foundation.org>]

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)
{
	...
}