Re: [PATCH v2 3/4] strbuf_setlen: don't write to strbuf_slopbuf

From: Brandon Casey <drafnel@gmail.com>
Date: Aug 23, 2017, 22:39 UTC
Message-ID: <CA+sFfMdvOcXd_ePyqyiCXL9O6xpYxxn+iKw6NRJCYsiCFK_ADA@mail.gmail.com>
In-Reply-To: <xmqq378hylbd.fsf@gitster.mtv.corp.google.com>

On Wed, Aug 23, 2017 at 3:24 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 17 quoted lines

> Brandon Casey <drafnel@gmail.com> writes:
>
>> On Wed, Aug 23, 2017 at 2:04 PM, Junio C Hamano <gitster@pobox.com> wrote:
>>> Brandon Casey <drafnel@gmail.com> writes:
>>>
>>>> So is there any reason why didn't do something like the following in
>>>> the first place?
>>>
>>> My guess is that we didn't bother; if we cared, we would have used a
>>> single instance of const char in a read-only segment, instead of
>>> such a macro.
>>
>> I think you mean something like this:
>>
>>    const char * const strbuf_slopbuf = "";
>
> Rather, more like "const char slopbuf[1];"

You'd think that would be sufficient right? Apparently gcc and clang will only place a variable marked as const in the read-only section if you initialize it with a constant too. (gcc 4.9.2, clang 3.8.1 on linux, clang 8.1.0 on osx)

I might have to adjust my stance on initializing global variables moving forward :-)

-Brandon