On Fri, 2016-06-03 at 10:49 -0500, Andrew F. Davis wrote:
> On 06/03/2016 10:41 AM, Joe Perches wrote:
> > On Fri, 2016-06-03 at 10:25 -0500, Nishanth Menon wrote:
> > > In some functions, returning a -ve decimal value is actually a valid
> > > return condition when the function is returning a value, however, it
> > > can also be misused for returning an error value that should ideally
> > > be a valid error code defined in include/uapi/asm-generic/errno-base.h
> > > or include/uapi/asm-generic/errno.h
> > >
> > > Considering typical newbie error of doing the following:
> > > int fn(void)
> > > {
> > > /* ... error condition ... */
> > > return -1;
> > > }
> > >
> > > void fn1(void)
> > > {
> > > /* some code */
> > > if (fn() < 0) {
> > > pr_err("Error occurred\n");
> > > return;
> > > }
> > > /* other cases... */
> > > }
> > >
> > > Flag this as a check case for developer verification.
> > I think it's not a newbie error to have a -1 return and it
> > seems like rather too many cases to even suggest be changed.
> >
> > $ git grep -E "\breturn\s+\-\s*[0-9]+" * | grep -v "^tools" | wc -l
> > 8388
> >
> A quick look over some of these cases show many *should* be replaced
> with proper error codes.
>
> Removing the simple -1 case, which is often used for signaling one level
> up of an error, gives better results though:
>
> $ git grep -E "\breturn\s+\-\s*[2-9][0-9]*" * | grep -v "^tools" | wc -l
> 189
I did more or less the same grep, and that's somewhat true.
-1 though is very common and doesn't need to be replaced.
$ git grep -E "\breturn\s+\-\s*[0-9]+\s*;" * | grep -v "^tools" | grep -vP
"return\s*\-1;" | wc -l
211
Looking at some of the specific instances of negative return values
instead of the line counts though may show otherwise.
-EFOO errors aren't always better.
