Re: [PATCH] staging: rts5208: rewrite macro with GNU extension __auto_type

[Jules Irenge]

On Mon, 4 Nov 2019, Greg KH wrote:

> On Mon, Nov 04, 2019 at 04:44:00PM +0000, Jules Irenge wrote:
> > Rewrite macro function with GNU extension __auto_type
> > to remove issue detected by checkpatch tool.
> > CHECK: MACRO argument reuse - possible side-effects?
> > 
> > Signed-off-by: Jules Irenge <jbi.octave@xxxxxxxxx>
> > ---
> >  drivers/staging/rts5208/rtsx_chip.h | 92 +++++++++++++++++------------
> >  1 file changed, 55 insertions(+), 37 deletions(-)
> > 
> > diff --git a/drivers/staging/rts5208/rtsx_chip.h b/drivers/staging/rts5208/rtsx_chip.h
> > index bac65784d4a1..4b986d5c68da 100644
> > --- a/drivers/staging/rts5208/rtsx_chip.h
> > +++ b/drivers/staging/rts5208/rtsx_chip.h
> > @@ -386,23 +386,31 @@ struct zone_entry {
> >  
> >  /* SD card */
> >  #define CHK_SD(sd_card)			(((sd_card)->sd_type & 0xFF) == TYPE_SD)
> > -#define CHK_SD_HS(sd_card)		(CHK_SD(sd_card) && \
> > -					 ((sd_card)->sd_type & SD_HS))
> > -#define CHK_SD_SDR50(sd_card)		(CHK_SD(sd_card) && \
> > -					 ((sd_card)->sd_type & SD_SDR50))
> > -#define CHK_SD_DDR50(sd_card)		(CHK_SD(sd_card) && \
> > -					 ((sd_card)->sd_type & SD_DDR50))
> > -#define CHK_SD_SDR104(sd_card)		(CHK_SD(sd_card) && \
> > -					 ((sd_card)->sd_type & SD_SDR104))
> > -#define CHK_SD_HCXC(sd_card)		(CHK_SD(sd_card) && \
> > -					 ((sd_card)->sd_type & SD_HCXC))
> > -#define CHK_SD_HC(sd_card)		(CHK_SD_HCXC(sd_card) && \
> > -					 ((sd_card)->capacity <= 0x4000000))
> > -#define CHK_SD_XC(sd_card)		(CHK_SD_HCXC(sd_card) && \
> > -					 ((sd_card)->capacity > 0x4000000))
> > -#define CHK_SD30_SPEED(sd_card)		(CHK_SD_SDR50(sd_card) || \
> > -					 CHK_SD_DDR50(sd_card) || \
> > -					 CHK_SD_SDR104(sd_card))
> > +#define CHK_SD_HS(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD(_sd) && \
> > +					 (_sd->sd_type & SD_HS); })
> > +#define CHK_SD_SDR50(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD(_sd) && \
> > +					 (_sd->sd_type & SD_SDR50); })
> > +#define CHK_SD_DDR50(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD(_sd) && \
> > +					 (_sd->sd_type & SD_DDR50); })
> > +#define CHK_SD_SDR104(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD(_sd) && \
> > +					 (_sd->sd_type & SD_SDR104); })
> > +#define CHK_SD_HCXC(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD(_sd) && \
> > +					 (_sd->sd_type & SD_HCXC); })
> > +#define CHK_SD_HC(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD_HCXC(_sd) && \
> > +					(_sd->capacity <= 0x4000000); })
> > +#define CHK_SD_XC(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD_HCXC(_sd) && \
> > +					 (_sd->capacity > 0x4000000); })
> > +#define CHK_SD30_SPEED(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_SD_SDR50(_sd) || \
> > +					CHK_SD_DDR50(_sd) || \
> > +					CHK_SD_SDR104(_sd); })
> >  
> >  #define SET_SD(sd_card)			((sd_card)->sd_type = TYPE_SD)
> >  #define SET_SD_HS(sd_card)		((sd_card)->sd_type |= SD_HS)
> > @@ -420,18 +428,24 @@ struct zone_entry {
> >  /* MMC card */
> >  #define CHK_MMC(sd_card)		(((sd_card)->sd_type & 0xFF) == \
> >  					 TYPE_MMC)
> > -#define CHK_MMC_26M(sd_card)		(CHK_MMC(sd_card) && \
> > -					 ((sd_card)->sd_type & MMC_26M))
> > -#define CHK_MMC_52M(sd_card)		(CHK_MMC(sd_card) && \
> > -					 ((sd_card)->sd_type & MMC_52M))
> > -#define CHK_MMC_4BIT(sd_card)		(CHK_MMC(sd_card) && \
> > -					 ((sd_card)->sd_type & MMC_4BIT))
> > -#define CHK_MMC_8BIT(sd_card)		(CHK_MMC(sd_card) && \
> > -					 ((sd_card)->sd_type & MMC_8BIT))
> > -#define CHK_MMC_SECTOR_MODE(sd_card)	(CHK_MMC(sd_card) && \
> > -					 ((sd_card)->sd_type & MMC_SECTOR_MODE))
> > -#define CHK_MMC_DDR52(sd_card)		(CHK_MMC(sd_card) && \
> > -					 ((sd_card)->sd_type & MMC_DDR52))
> > +#define CHK_MMC_26M(sd_card)\
> > +	({__auto_type _sd = sd_card; CHK_MMC(_sd) && \
> > +					 (_sd->sd_type & MMC_26M); })
> 
> Ick, no.  These are obviously pointers, which can not be "evaluated
> twice" so this whole thing is just fine.
> 
> checkpatch is just a "hint" that you might want to look at the code.
> This stuff is just fine, look at how it is being used for proof of that.
> 
> thanks,
> 
> greg k-h
> 
Thanks for the feedback. It's good to know. I really appreciate.
Kind regards,
Jules