linux-kernel - Re: [PATCH v1 1/5] staging: wfx: fix warnings of no space is necessary

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Message-ID: <6e6bc92cac0858fe5bd37b28f688d3da043f4bef.camel@perches.com>
Date:   Sun, 20 Oct 2019 12:36:50 -0700
From:   Joe Perches <joe@...ches.com>
To:     Dan Carpenter <dan.carpenter@...cle.com>,
        Julia Lawall <julia.lawall@...6.fr>
Cc:     Jules Irenge <jbi.octave@...il.com>, devel@...verdev.osuosl.org,
        outreachy-kernel@...glegroups.com, linux-kernel@...r.kernel.org,
        gregkh@...uxfoundation.org
Subject: Re: [PATCH v1 1/5] staging: wfx: fix warnings of no space is
 necessary

On Sun, 2019-10-20 at 22:17 +0300, Dan Carpenter wrote:
> On Sat, Oct 19, 2019 at 01:02:31PM -0700, Joe Perches wrote:
> > diff -u -p a/rtl8723bs/core/rtw_mlme_ext.c b/rtl8723bs/core/rtw_mlme_ext.c
[]
> > @@ -1132,7 +1132,7 @@ unsigned int OnAuthClient(struct adapter
> >  				goto authclnt_fail;
> >  			}
> >  
> > -			memcpy((void *)(pmlmeinfo->chg_txt), (void *)(p + 2), len);
> > +			memcpy((void *)(pmlmeinfo->chg_txt), (p + 2), len);
> 
> I wonder why it didn't remove the first void cast?

drivers/staging/rtl8723bs/include/sta_info.h:151:       unsigned char chg_txt[128];

I think the cocci transforms for an array do not match a pointer
and I wrote the cocci script without much care.

btw;

There's probably a generic cocci mechanism to check function
prototypes and then remove uses of unnecessary void pointer casts
in function calls.  I'm not going to try to figure out that syntax.

> [ The rest of the email is bonus comments for outreachy developers ].
> 
> And someone needs to check the final patch probably to remove the extra
> parentheses around "(p + 2)".  Those were necessary when for the cast
> but not required after the cast is gone.
> 
> >  			pmlmeinfo->auth_seq = 3;
> >  			issue_auth(padapter, NULL, 0);
> >  			set_link_timer(pmlmeext, REAUTH_TO);
> 
> It's sort of tricky to know what "one thing per patch means".

It seems somewhat arbitrary and based on Greg's understanding
of the experience of the patch submitter and also the language
of the potential commit message.

> -       memset((void *)(&(pHTInfo->SelfHTCap)), 0,
> +       memset((&(pHTInfo->SelfHTCap)), 0,
>                 sizeof(pHTInfo->SelfHTCap));
> 
> Here the parentheses were never related to the cast so we should leave
> them as is.  In other words, in the first example, if we didn't remove
> the cast that would be "half a thing per patch" and in the second
> example that would be "two things in one patch".

For style patches, it's frequently easier and better to 
do all the code transformation at once.

IMO the last should be:

	memset(&pHTInfo->SelfHTCap, 0, sizeof(pHTInfo->SelfHTCap));

like it is here:

drivers/staging/rtl8192u/ieee80211/rtl819x_HTProc.c:1056:       memset(&pHTInfo->SelfHTCap, 0, sizeof(pHTInfo->SelfHTCap));

btw2:

I really dislike all the code inconsistencies and
unnecessary code duplication with miscellaneous changes
in the rtl staging drivers....

Horrid stuff.