Re: [PATCH] staging: rtl8723bs: core: rtw_recv: fix warning Comparison to NULL

[Joe Perches]

On Thu, 2019-05-16 at 23:55 +0530, Hariprasad Kelam wrote:
> On Thu, May 16, 2019 at 11:00:56AM +0300, Dan Carpenter wrote:
> > On Wed, May 15, 2019 at 11:15:36PM +0530, Hariprasad Kelam wrote:
> > > @@ -1042,7 +1042,7 @@ sint sta2ap_data_frame(
> > >  		}
> > >  
> > >  		*psta = rtw_get_stainfo(pstapriv, pattrib->src);
> > > -		if (*psta == NULL) {
> > > +		if (!*psta == NULL) {
> >                     ^^^^^^^^^^^^^^
> > It's surprising that this didn't cause some kind of warning somewhere...
> 
> Thanks for pointing out this error. Here my intention is to write
>                 if(!*psta) 
> but somehow i missed it .
> 
> Will resend this patch after correcting the same.Like below
> 
> > -           if (*psta == NULL) {
> > > +           if (!*psta) {

You could run the coccinelle spatch file for bool
comparisons on the files instead.  It's much less
error prone.

$ spatch --sp-file scripts/coccinelle/misc/boolconv.cocci --in-place drivers/staging/rtl8723bs/

Or you could use a patch to checkpatch like below and then use

$ git ls-files drivers/staging/rtl8723bs | \
  xargs ./scripts/checkpatch.pl -f --fix-inplace --types=bool_comparison

but that definitely would not be as good as the coccinelle
tool use as coccinelle is much better at parsing expressions.

---
 scripts/checkpatch.pl | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 1c421ac42b07..fe83aa0b1f97 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6407,11 +6407,13 @@ sub process {
 					$op = "";
 				}
 
-				CHK("BOOL_COMPARISON",
-				    "Using comparison to $otype is error prone\n" . $herecurr);
-
+				if (CHK("BOOL_COMPARISON",
+					"Using comparison to $otype is error prone\n" . $herecurr) &&
+				    $fix) {
+					$fixed[$fixlinenr] =~ s/\b(?:true|false|$Lval)\s*(?:==|\!=)\s*(?:true|false|$Lval)\b/${op}${arg}/;
+				}
 ## maybe suggesting a correct construct would better
-##				    "Using comparison to $otype is error prone.  Perhaps use '${lead}${op}${arg}${trail}'\n" . $herecurr);
+##					"Using comparison to $otype is error prone.  Perhaps use '${lead}${op}${arg}${trail}'\n" . $herecurr);
 
 			}
 		}