Re: [boost] Are warnings acceptable artifacts from builds?

Subject: Re: [boost] Are warnings acceptable artifacts from builds?
From: Stewart, Robert (Robert.Stewart_at_[hidden])
Date: 2009-09-09 11:22:12

Vinnie wrote:
>
> >From http://sqlite.org/testing.html#coverage
>
> "Static analysis means analyzing code at or before
> compile-time to check for correctness. Static analysis
> consists mostly of making sure SQLite compiles without
> warnings, even when all warnings are enabled. SQLite is
> developed primarily using GCC and it does compile without
> warnings on GCC using the -Wall and -Wextra flags. There are
> occasional reports of warnings coming from VC++, however.
>
> Static analysis has not proven to be helpful in finding bugs.
> We cannot call to mind a single problem in SQLite that was
> detected by static analysis that was not first seen by one of
> the other testing methods described above. On the other hand,
> we have on occasion introduced new bugs in our efforts to get
> SQLite to compile without warnings.
>
> Our experience, then, is that static analysis is
> counter-productive to quality. In other words, focusing on
> static analysis (being concerned with compiler warnings)
> actually reduces the quality of the code. Nevertheless, we
> developers have capitulated to pressure from users and
> actively work to eliminate compiler warnings. We are willing
> to do this because the other tests described above do an
> excellent job of finding the bugs that are often introduced
> when removing compiler warnings, so that product quality is
> probably not decreased as a result."

My experience has been quite the contrary.  Chasing down compiler warnings has eliminated a good number of bugs in shared code here.  Sure, some of the bugs could have been found with better testing, but we have what we have.  Using a belt and suspenders is often helpful!

Even for the SQLite team, eliminating all warnings makes new ones more promiment such that a developer is quickly alerted to what might be an issue before the code is checked in or undergoes testing.

_____
Rob Stewart                           robert.stewart_at_[hidden]
Software Engineer, Core Software      using std::disclaimer;
Susquehanna International Group, LLP  http://www.sig.com

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