From: Joerg Bruehe
Date: September 24 2010 7:33am
Subject: Re: [STYLE] could we allow // for comments alone on their line?
List-Archive: http://lists.mysql.com/internals/38112
Message-Id: <4C9C543F.1030600@oracle.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-15
Content-Transfer-Encoding: quoted-printable

Hi Guilhem, all!


To me, your question has both a style and a technical aspect.

Guilhem Bichot wrote:
> [[...]]
>=20
> So the proposal is merely to allow
> // this is a comment which is alone on its line
> in C++ code.
> I'm fine if we continue forbidding
> // this is
> // a multi-line
> // comment
> and require /* */ instead.
>=20

My technical comment on "//":

The increased use of "//" comments in C++ files raises the risk of using
them in C files, which will not be rejected by most C compilers
(including gcc) but will cause compilation failures with IBM C (which we
use on AIX and i5/os).

We have had several release builds fail because of this, it is simply
detected too late. So the build team has to fix it, push, and start a
rebuild. Considering that AIX and i5os are not our fastest platforms and
that we might not detect the failure immediately, the delay may be
significant.

I would prefer not to use "//" at all, just to avoid that it might
become a habit which then affects C files.


My style comment (includes technical reasoning):

For multi-line comments, my preference would be
   /*
    * the real comment
    * maybe several lines
    */
so that a commented code line returned by "grep" does not look like
active code. (I have been bitten several times by this when checking
MySQL code: a variable looked like being used when in fact all use was
already turned into comments.)
However, this style differs from current MySQL conventions so I will not
pursue this myself (but would support others who feel similar).


Regards,
J=F6rg

--=20
Joerg Bruehe,  MySQL Build Team,  joerg.bruehe@stripped
               (+49 30) 417 01 487
ORACLE Deutschland B.V. & Co. KG,   Komturstrasse 18a,   D-12099 Berlin
Geschaeftsfuehrer: Juergen Kunz, Marcel v.d. Molen, Alexander v.d. Ven
Amtsgericht Muenchen: HRA 95603