Re: [PATCH] git-compat-util.h: introduce CALLOC(x)

[Taylor Blau <me@ttaylorr.com>]

On Mon, Dec 05, 2022 at 08:43:50PM -0500, Jeff King wrote:
> On Mon, Dec 05, 2022 at 05:36:25PM -0500, Taylor Blau wrote:
>
> > On Mon, Dec 05, 2022 at 10:01:11PM +0100, René Scharfe wrote:
> > > This rule would turn this code:
> > >
> > > 	struct foo *bar = xcalloc(1, sizeof(*bar));
> > > 	int i;
> > >
> > > ... into:
> > >
> > > 	struct foo *bar;
> > > 	CALLOC(bar);
> > > 	int i;
> > >
> > > ... which violates the coding guideline to not mix declarations and
> > > statements (-Wdeclaration-after-statement).
> >
> > Yeah, I was wondering about this myself when I wrote this part of the
> > Coccinelle patch.
> >
> > Is there an intelligent way to tell it to put the first statement after
> > all declarations? I couldn't find anything after a quick scan of the
> > documentation nor our own patches.
>
> It feels like generating the code as above is not the end of the world.
> The most valuable thing that coccinelle is doing here is _finding_ the
> location, and telling you "it's supposed to be like this". It is great
> when the "this" post-image is perfect and doesn't need further tweaking.

I have to agree. If Coccinelle can generate the right output; great. But
if it can't, the amount of additional work to reorganize an already
generated and mostly correct *.patch from the tool seems minimal by
comparison.

> But if the compiler then reminds you "hey, you need to go a bit further
> manually", that doesn't seem so bad. In other words, I would be happy to
> follow that work flow if I introduced a bare xcalloc(). My only worry is
> that somebody less experienced with the project (or with C) would get
> confused.

Agreed.

Thanks,
Taylor