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From: Junio C Hamano <gitster@pobox.com>
To: Johannes Sixt <j6t@kdbg.org>
Cc: Ramsay Jones <ramsay@ramsayjones.plus.com>,
	Thomas Gummerer <t.gummerer@gmail.com>,
	GIT Mailing-list <git@vger.kernel.org>
Subject: Re: [PATCH] range-diff: fix some 'hdr-check' and sparse warnings
Date: Fri, 12 Jul 2019 09:44:36 -0700	[thread overview]
Message-ID: <xmqqy313p5hn.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <41a60e60-d2c0-7d54-5456-e44d106548a4@kdbg.org> (Johannes Sixt's message of "Fri, 12 Jul 2019 07:21:08 +0200")

Johannes Sixt <j6t@kdbg.org> writes:

> Am 12.07.19 um 00:03 schrieb Ramsay Jones:
>> diff --git a/range-diff.c b/range-diff.c
>> index ba1e9a4265..0f24a4ad12 100644
>> --- a/range-diff.c
>> +++ b/range-diff.c
>> @@ -102,7 +102,7 @@ static int read_patches(const char *range, struct string_list *list)
>>  		}
>>  
>>  		if (starts_with(line, "diff --git")) {
>> -			struct patch patch = { 0 };
>> +			struct patch patch = { NULL };
>
> There is nothing wrong with 0 here. IMHO, zero-initialization should
> *always* be written as = { 0 } and nothing else. Changing 0 to NULL to
> pacify sparse encourages a wrong style.
>
> -- Hannes

Hmm, care to elaborate a bit?  Certainly, we have a clear preference
between these two:

	struct patch patch;
	patch.new_name = 0;
	patch.new_name = NULL;

where the "char *new_name" field is the first one in the structure.
We always try to write the latter, even though we know they ought to
be equivalent to the language lawyers.

Is the reason why you say 0 is fine here because we consider

	struct patch patch, *dpatch;
	memset(&patch, 0, sizeof(patch));
	dpatch = xcalloc(1, sizeof(patch));

are perfectly good way to trivially iniitialize an instance of the
struct?

Do we want to talk to sparse folks about this?


  reply	other threads:[~2019-07-12 16:44 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-11 22:03 [PATCH] range-diff: fix some 'hdr-check' and sparse warnings Ramsay Jones
2019-07-12  5:21 ` Johannes Sixt
2019-07-12 16:44   ` Junio C Hamano [this message]
2019-07-13 10:44     ` Johannes Sixt
2019-07-13 12:18       ` Johannes Sixt
2019-07-13 12:56       ` Carlo Arenas
2019-07-13 21:29       ` Junio C Hamano
2019-07-13 22:22         ` Carlo Arenas
2019-07-14  0:51           ` Jeff King
2019-07-14  8:30             ` Johannes Sixt
2019-07-15 14:46               ` Jeff King
2019-07-15 17:30                 ` Johannes Sixt
2019-07-15 18:15                   ` Jeff King
2019-07-16 19:01                     ` Junio C Hamano
2019-07-16 20:01                       ` Jeff King
2019-07-17 18:13                         ` Junio C Hamano
2019-07-17 19:21                           ` Jeff King
2019-07-17 20:10                             ` Junio C Hamano
2019-07-17 17:23                       ` Johannes Sixt
2019-07-15 14:47           ` Johannes Schindelin
2020-10-02 17:03             ` Junio C Hamano
2020-10-04 18:35               ` Johannes Schindelin
2019-07-14  8:15         ` Johannes Sixt

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