[PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Hannes Eder]

Impact: include a prototype for the exported function in the macro

Fix about 20 of this warnings:

  drivers/hid/hid-a4tech.c:162:1: warning: symbol 'hid_compat_a4tech' was not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
---
 include/linux/hid.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 215035b..81aa84d 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -793,6 +793,8 @@ dbg_hid(const char *fmt, ...)
 
 #ifdef CONFIG_HID_COMPAT
 #define HID_COMPAT_LOAD_DRIVER(name)	\
+/* prototype to avoid sparse warning */	\
+extern void hid_compat_##name(void);	\
 void hid_compat_##name(void) { }	\
 EXPORT_SYMBOL(hid_compat_##name)
 #else
-- 
1.5.6.3

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Jiri Kosina]

On Tue, 16 Dec 2008, Hannes Eder wrote:

> Impact: include a prototype for the exported function in the macro
> 
> Fix about 20 of this warnings:
> 
>   drivers/hid/hid-a4tech.c:162:1: warning: symbol 'hid_compat_a4tech' was not declared. Should it be static?
> 
> Signed-off-by: Hannes Eder <hannes@hanneseder.net>

Applied, thanks.

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Ben Dooks]

On Tue, Dec 16, 2008 at 01:31:31PM +0100, Hannes Eder wrote:
> Impact: include a prototype for the exported function in the macro
> 
> Fix about 20 of this warnings:
> 
>   drivers/hid/hid-a4tech.c:162:1: warning: symbol 'hid_compat_a4tech' was not declared. Should it be static?
> 
> Signed-off-by: Hannes Eder <hannes@hanneseder.net>
> ---
>  include/linux/hid.h |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/hid.h b/include/linux/hid.h
> index 215035b..81aa84d 100644
> --- a/include/linux/hid.h
> +++ b/include/linux/hid.h
> @@ -793,6 +793,8 @@ dbg_hid(const char *fmt, ...)
>  
>  #ifdef CONFIG_HID_COMPAT
>  #define HID_COMPAT_LOAD_DRIVER(name)	\
> +/* prototype to avoid sparse warning */	\
> +extern void hid_compat_##name(void);	\
>  void hid_compat_##name(void) { }	\

surely this could simply be changed to 'static void hid_compat_##name(void)'
if it is only being defined to be an empty function?

>  EXPORT_SYMBOL(hid_compat_##name)
>  #else
> -- 
> 1.5.6.3
> 
> --
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-- 
Ben (ben@fluff.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Jiri Kosina]

On Tue, 16 Dec 2008, Ben Dooks wrote:

> >  #ifdef CONFIG_HID_COMPAT
> >  #define HID_COMPAT_LOAD_DRIVER(name)	\
> > +/* prototype to avoid sparse warning */	\
> > +extern void hid_compat_##name(void);	\
> >  void hid_compat_##name(void) { }	\
> surely this could simply be changed to 'static void 
> hid_compat_##name(void)' if it is only being defined to be an empty 

This will cause gcc emit warnings about unused symbols.

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Ben Dooks]

On Tue, Dec 16, 2008 at 05:01:38PM +0100, Jiri Kosina wrote:
> On Tue, 16 Dec 2008, Ben Dooks wrote:
> 
> > >  #ifdef CONFIG_HID_COMPAT
> > >  #define HID_COMPAT_LOAD_DRIVER(name)	\
> > > +/* prototype to avoid sparse warning */	\
> > > +extern void hid_compat_##name(void);	\
> > >  void hid_compat_##name(void) { }	\
> > surely this could simply be changed to 'static void 
> > hid_compat_##name(void)' if it is only being defined to be an empty 
> 
> This will cause gcc emit warnings about unused symbols.

sorry, 'static inline void' then.
 
> -- 
> Jiri Kosina
> SUSE Labs
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

-- 
Ben (ben@fluff.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Hannes Eder]

On Tue, Dec 16, 2008 at 5:01 PM, Jiri Kosina <jkosina@suse.cz> wrote:
> On Tue, 16 Dec 2008, Ben Dooks wrote:
>
>> >  #ifdef CONFIG_HID_COMPAT
>> >  #define HID_COMPAT_LOAD_DRIVER(name)       \
>> > +/* prototype to avoid sparse warning */    \
>> > +extern void hid_compat_##name(void);       \
>> >  void hid_compat_##name(void) { }   \
>> surely this could simply be changed to 'static void
>> hid_compat_##name(void)' if it is only being defined to be an empty
>
> This will cause gcc emit warnings about unused symbols.

The real problem is that the symbol (in that case the function) is not
exported if defined static.

e.g.:

$ cat >foobar.c <<EOF
> static void foo(void) {}
> extern void foo(void);
>
> void bar(void) {}
> EOF
$ gcc -c foobar.c
$ nm foobar.o
00000005 T bar
00000000 t foo

from the nm manpage:
The  symbol  type. ... If lowercase, the symbol is local; if
uppercase, the symbol is global (external)

i.e. foo is local

see http://lkml.org/lkml/2008/9/4/495 for what ANSI C Std has to say
about that and about the proposed change.

But, don't ask my why the void functions with empty function bodies
are exported.

On Tue, Dec 16, 2008 at 8:41 PM, Ben Dooks <ben-linux@fluff.org> wrote:
> sorry, 'static inline void' then.

in that case the symbol would not even be local as it is not used with
the translation unit.

$ nm
00000005 T bar

-Hannes

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Jiri Slaby]

On 12/16/2008 08:44 PM, Hannes Eder wrote:
> But, don't ask my why the void functions with empty function bodies
> are exported.

Because of autoload to create a dependency. Note that this is a temporary
solution to workaround the non-presence of hid bus in module-init-tools and will
be removed in next few releases.

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Jiri Kosina]

On Fri, 19 Dec 2008, Jiri Slaby wrote:

> > But, don't ask my why the void functions with empty function bodies 
> > are exported.
> Because of autoload to create a dependency. Note that this is a temporary
> solution to workaround the non-presence of hid bus in module-init-tools and will
> be removed in next few releases.

BTW while we are at it -- what is the status with module-init-tools? Has 
the support been merged already?

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Jiri Slaby]

Jiri Kosina wrote:
> BTW while we are at it -- what is the status with module-init-tools? Has 
> the support been merged already?

As far as I can see, not yet. Jon, what's the status of hid bus support in
m-i-t, please?

Re: [PATCH] HID: avoid sparse warning in HID_COMPAT_LOAD_DRIVER

[Jiri Kosina]

On Sat, 20 Dec 2008, Jiri Slaby wrote:

> > BTW while we are at it -- what is the status with module-init-tools? Has 
> > the support been merged already?
> As far as I can see, not yet. Jon, what's the status of hid bus support in
> m-i-t, please?

Any update here please? What is the current status in m-i-t?

Thanks,

-- 
Jiri Kosina
SUSE Labs