Re: Potential static analysis ideas

[Dan Carpenter <dan.carpenter@oracle.com>]

On Sat, Jul 24, 2021 at 03:33:48PM +0200, Geert Uytterhoeven wrote:
> > Here is another example of something which I have a check for but I
> > haven't pushed.
> >
> >         ret = frob();
> >         if (!ret)
> >                 return ret;
> >
> > This code is normally correct but sometimes it means the if statement is
> > reversed and it should be "if (ret) return ret;".  To me returning a
> > literal is always more clear but but clearly the original author felt
> > "ret" was more clear...  It's only a few bugs per year so it's not a big
> > deal either way.
> 
> To make it work well, you need to know if frob() and/or the current
> function return an error code or not.  While you can use some heuristics
> (e.g. is there any return -Exxx), perhaps we can add an annotation to
> indicate if a function returns an error code, or an error pointer?

The function is normal return zero or error codes, but the question is
do we want to return for success or for failure.  This kind of bug is
normally caught very early in testing but some of the big refactor
patches can't be tested on every hardware.

regards,
dan carpenter