AW: Software Quality Binutils

[Christoph Hazott <Christoph dot Hazott at live dot de>]

Hi to all,

I'm very happy because I think we are at the same page here :-)
@John: CppCheck and pmccabe look already quite promising and could be a much better alternative than the sonar check I did. The pa_ip function is awesome I have to say :-D ~2000LOC with almost all loops and branches is a real challenge to maintain and much more of a challenge to refactor properly to not miss anything! 
@Nick: The check with sonar was done with the cx11 code rules from sonar. Also I don't like the bug term in sonar because a bug is something that is defined to lead to faults. An I personally think that this can be indicated by a static code analysis tool but real proof you only get over a dynamic code analysis (like unit testing). And to answer your questions. If "we" do static code analysis on the binutils we would need to have to define a set of rules and tools that really apply and make sense to further progress. The function John mentioned is a good example. If we assume that every node in the program is binary the CC tells us that 2^499 unit tests will cover this function. E.g. refactoring this to have 10 tests with a complexity of ~49 means we need around 10*2^49 tests to reach the same coverage. That's just a made up example but that's the direction where static code analysis is aiming.
@Paul: That's true and from my experience the graph system in the background of the tools I used so far was always able to identify the proper case.

Maybe it would be an idea that we pick out a module or function as a starting point which I then can work through to continue this conversation on a real example? The pa_ip function would already be quite an awesome challenge for this?

What do you think?

Regards,

Christoph


-----Ursprüngliche Nachricht-----
Von: Paul Koning [mailto:paulkoning@comcast.net] 
Gesendet: Tuesday, 14 August 2018 15:22
An: John Darrington
Cc: Nick Clifton; Christoph Hazott; binutils@sourceware.org
Betreff: Re: Software Quality Binutils



> On Aug 14, 2018, at 7:12 AM, John Darrington <john@darrington.wattle.id.au> wrote:
> 
> ...
> I think it's flagging things like:
> 
> if (cond)
> {
>  do_this ();
>  do_that ();
> }
> else
> {
>  do_this ();
> }
> 
> ... which it wants changed to:
> 
> do_this ();
> if (cond)
> do_that ();
> 
> 
> which of-course has the same effect iff evaluating cond does not
> have side effects.

Not so; if do_this() may change cond, then the two are semantically different.

	paul