Re: [PATCH] mailinfo: resolve -Wstring-plus-int warning

From: Eric Sunshine <sunshine@sunshineco.com>
Date: Sep 22, 2014, 21:10 UTC
Message-ID: <CAPig+cTAFaG5H8rmf1jrvFwr_OOH7u19JMKDUE12UddokUmfaQ@mail.gmail.com>
In-Reply-To: <xmqqk34vlfhz.fsf@gitster.dls.corp.google.com>

On Mon, Sep 22, 2014 at 1:41 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 12 quoted lines

> Eric Sunshine <sunshine@sunshineco.com> writes:
>
>> The just-released Apple Xcode 6.0.1 has -Wstring-plus-int enabled by
>> default which complains about pointer arithmetic applied to a string
>> literal:
>>
>>     builtin/mailinfo.c:303:24: warning:
>>         adding 'long' to a string does not append to the string
>>             return !memcmp(SAMPLE + (cp - line), cp, strlen(SAMPLE) ...
>>                            ~~~~~~~^~~~~~~~~~~~~
>
> And why is that a warning-worthy violation?

Not being privy to Apple's decision making process, I can only guess that it is in response to their new Swift programming language which they are pushing heavily on iOS (and soon Mac OS X), in which '+' is the string concatenation operator. For projects written in Swift and incorporating legacy or portable components in C, C++, or Objective-C, the warning may help programmer's avoid the pitfall of thinking that '+' is also concatenation in the C-based languages.

> Can we have them fix their compiler instead?

If the above supposition is correct, then it's likely that Apple considers this a feature, not a bug which needs to be fixed.

>> Resolve this issue.
>>
>> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>