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From:   Eric Sunshine <sunshine@sunshineco.com>
Date:   Sun, 10 Jul 2022 22:41:12 -0400
Message-ID: <CAPig+cQJWgerk08j=1b=aWRZsKBu3BnEACQuiqktU4BwzM-xaA@mail.gmail.com>
Subject: Re: [PATCH] unpack-objects: fix compilation warning/error due to
 missing braces
To:     Han Xin <chiyutianyi@gmail.com>
Cc:     Git List <git@vger.kernel.org>,
        =?UTF-8?B?w4Z2YXIgQXJuZmrDtnLDsCBCamFybWFzb24=?= <avarab@gmail.com>
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On Sun, Jul 10, 2022 at 10:00 PM Han Xin <chiyutianyi@gmail.com> wrote:
> On Sun, Jul 10, 2022 at 4:12 PM Eric Sunshine <sunshine@sunshineco.com> wrote:
> > On macOS High Sierra (10.13), Apple's `clang`[1] complains about missing
> > braces around initialization of a subobject, which is problematic when
> > building with `DEVELOPER=YesPlease` which enables `-Werror`:
> >
> >     builtin/unpack-objects.c:388:26: error: suggest braces around
> >         initialization of subobject [-Werror,-Wmissing-braces]
> >             git_zstream zstream = { 0 };
> >
> > [1]: `cc --version` => "Apple LLVM version 10.0.0 (clang-1000.10.44.4)"
> > -       git_zstream zstream = { 0 };
> > +       git_zstream zstream = {{ 0 }};
>
> Not a comment, just wondering, when should I use "{ { 0 } }" and when
> should I use "{ 0 }"?
>
> I didn't get the error with "Apple clang version 13.0.0
> (clang-1300.0.29.30)",  because it's
> a higher version ?

I don't have a good answer. More modern `clang` versions don't seem to
complain about plain old `{0}` here, but the older `clang` with which
I'm stuck does complain. Aside from actually building the project with
an older `clang` (or older Apple-specific `clang`), it may be
sufficient to inspect the structure that's being initialized to see if
the first element is itself a subobject. However, I'm not sure it's
worth the effort to do so considering how rare this problem seems to
be.