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From: "Martin Ågren" <martin.agren@gmail.com>
To: Jeff King <peff@peff.net>
Cc: Git Mailing List <git@vger.kernel.org>,
	"brian m . carlson" <sandals@crustytoothpaste.net>
Subject: Re: [PATCH v3 2/2] setup: fix memory leaks with `struct repository_format`
Date: Mon, 25 Feb 2019 20:21:07 +0100	[thread overview]
Message-ID: <CAN0heSq=0=B-FoPWcuRxp0oJ6capo3Pu4txZZOP2uDeNn5N1Og@mail.gmail.com> (raw)
In-Reply-To: <20190125195107.GA6520@sigill.intra.peff.net>

On Fri, 25 Jan 2019 at 20:51, Jeff King <peff@peff.net> wrote:
>
> > On Wed, 23 Jan 2019 at 06:57, Jeff King <peff@peff.net> wrote:
> > >
> > > On Tue, Jan 22, 2019 at 10:45:48PM +0100, Martin Ågren wrote:
> > >
> > > > Call `clear_...()` at the start of `read_...()` instead of just zeroing
> > > > the struct, since we sometimes enter the function multiple times. This
> > > > means that it is important to initialize the struct before calling
> > > > `read_...()`, so document that.
> > >
> > > This part is a little counter-intuitive to me. Is anybody ever going to
> > > pass in anything except a struct initialized to REPOSITORY_FORMAT_INIT?

> > > If so, might it be kinder for read_...() to not assume anything about
> > > the incoming struct, and initialize it from scratch? I.e., not to use
> > > clear() but just do the initialization step?
>
> I'm less worried about out-of-tree users, and more concerned with just
> having a calling convention that matches usual conventions (and is
> harder to get wrong).
>
> It's a pretty minor point, though, so I can live with it either way.

It's time to resurrect this thread. I've reworked this patch to avoid
the compound literal when re-initing a struct, and I've been going back
and forth on this point about having to initialize to `..._INIT` or risk
crashing. And I keep coming back to thinking that it's not *that*
different from how `STRBUF_INIT` works.

There's the obvious difference that there aren't as many functions to
call, so there's certainly a difference in scale. And you'd think that
you'll always start with `read_...()`, but another potential first
function to call is `clear_...()` (see builtin/init-db.c), in which case
you better have used `..._INIT` first.

I'm tempted to address this point by documenting as good as I can in the
.h-file that one has to use this initializer macro. I'll obviously
convert all users, so copy-paste programming should work fine...

How does that sound to you?

Martin

  reply	other threads:[~2019-02-25 19:21 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-18  7:25 [PATCH 0/3] setup: add `clear_repository_format()` Martin Ågren
2018-12-18  7:25 ` [PATCH 1/3] setup: drop return value from `read_repository_format()` Martin Ågren
2018-12-19 15:27   ` Jeff King
2018-12-19 21:42     ` Martin Ågren
2018-12-20  0:17     ` brian m. carlson
2018-12-20  2:52       ` Jeff King
2018-12-20  3:45         ` brian m. carlson
2018-12-20 14:53           ` Jeff King
2018-12-18  7:25 ` [PATCH 2/3] setup: do not use invalid `repository_format` Martin Ågren
2018-12-19  0:18   ` brian m. carlson
2018-12-19 21:43     ` Martin Ågren
2018-12-19 15:38   ` Jeff King
2018-12-19 21:46     ` Martin Ågren
2018-12-19 23:17       ` Jeff King
2018-12-20  0:21     ` brian m. carlson
2018-12-18  7:25 ` [PATCH 3/3] setup: add `clear_repository_format()` Martin Ågren
2018-12-19 15:48   ` Jeff King
2018-12-19 21:49     ` Martin Ågren
2019-01-14 18:34 ` [PATCH v2 0/3] " Martin Ågren
2019-01-14 18:34   ` [PATCH v2 1/3] setup: free old value before setting `work_tree` Martin Ågren
2019-01-14 18:34   ` [PATCH v2 2/3] setup: do not use invalid `repository_format` Martin Ågren
2019-01-15 19:31     ` Jeff King
2019-01-17  6:31       ` Martin Ågren
2019-01-22  7:07         ` Jeff King
2019-01-22 13:34           ` Martin Ågren
2019-01-22 21:45             ` [PATCH v3 0/2] setup: fix memory leaks with `struct repository_format` Martin Ågren
2019-01-22 21:45               ` [PATCH v3 1/2] setup: free old value before setting `work_tree` Martin Ågren
2019-01-22 21:45               ` [PATCH v3 2/2] setup: fix memory leaks with `struct repository_format` Martin Ågren
2019-01-23  5:57                 ` Jeff King
2019-01-24  0:14                   ` brian m. carlson
2019-01-25 19:25                     ` Martin Ågren
2019-01-25 19:24                   ` Martin Ågren
2019-01-25 19:51                     ` Jeff King
2019-02-25 19:21                       ` Martin Ågren [this message]
2019-02-26 17:46                         ` Jeff King
2019-02-28 20:36                           ` [PATCH v4 0/2] " Martin Ågren
2019-02-28 20:36                             ` [PATCH v4 1/2] setup: free old value before setting `work_tree` Martin Ågren
2019-02-28 20:36                             ` [PATCH v4 2/2] setup: fix memory leaks with `struct repository_format` Martin Ågren
2019-03-06  4:56                             ` [PATCH v4 0/2] " Jeff King
2019-01-14 18:34   ` [PATCH v2 3/3] setup: add `clear_repository_format()` Martin Ågren

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