Re: [Outreachy kernel] [PATCH] Staging: android: Remove unneeded definition in header file

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Oct 01, 2015 at 11:44:00AM +0530, Sudip Mukherjee wrote:
> On Thu, Oct 01, 2015 at 07:56:24AM +0200, Greg KH wrote:
> > On Thu, Oct 01, 2015 at 09:49:26AM +0530, Shraddha Barke wrote:
> > > These struct are globally defined in source file but they have been
> > > defined as static in .h file. Remove definition in header file as
> > > it is not needed. Also fix the compiler warning.
> > > 
> > > Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
> > > ---
> > >  drivers/staging/android/sw_sync.h | 15 ---------------
> > >  1 file changed, 15 deletions(-)
> > > 
> > > diff --git a/drivers/staging/android/sw_sync.h b/drivers/staging/android/sw_sync.h
> > > index c87ae9e..a671595 100644
> > > --- a/drivers/staging/android/sw_sync.h
> > > +++ b/drivers/staging/android/sw_sync.h
> > > @@ -39,21 +39,6 @@ struct sw_sync_timeline *sw_sync_timeline_create(const char *name);
> > >  void sw_sync_timeline_inc(struct sw_sync_timeline *obj, u32 inc);
> > >  
> > >  struct sync_pt *sw_sync_pt_create(struct sw_sync_timeline *obj, u32 value);
> > > -#else
> > > -static inline struct sw_sync_timeline *sw_sync_timeline_create(const char *name)
> > > -{
> > > -	return NULL;
> > > -}
> > > -
> > > -static inline void sw_sync_timeline_inc(struct sw_sync_timeline *obj, u32 inc)
> > > -{
> > > -}
> > > -
> > > -static inline struct sync_pt *sw_sync_pt_create(struct sw_sync_timeline *obj,
> > > -						u32 value)
> > > -{
> > > -	return NULL;
> > > -}
> > >  #endif /* IS_ENABLED(CONFIG_SW_SYNC) */
> > >  
> > >  #endif /* _LINUX_SW_SYNC_H */
> > 
> > You just broke the build for systems that don't define CONFIG_SW_SYNC
> > yet still call these functions :(
> 
> I had the same doubt so i tested it with CONFIG_SW_SYNC disabled in my
> .config, but the build didn't break.

That is because this code is for out-of-tree code :(

> Is it because the only use of sw_sync_timeline_inc is from sw_sync.c
> which will build only if CONFIG_SW_SYNC is defined?

Yes, but other files might use those functions and they need to still
build if the config option is not enabled.

thanks,

greg k-h