Re: [PATCH 2/3] combine-diff: suppress a clang warning

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 3, 2013, 19:58 UTC
Message-ID: <7vwqup890o.fsf@alter.siamese.dyndns.org>
In-Reply-To: <6995fd5e4d9cb3320ab80c983f1b25ae8a399284.1359901732.git.john@keeping.me.uk>

John Keeping <john@keeping.me.uk> writes:

Show 15 quoted lines

> When compiling combine-diff.c, clang 3.2 says:
>
>     combine-diff.c:1006:19: warning: adding 'int' to a string does not
> 	    append to the string [-Wstring-plus-int]
> 		prefix = COLONS + offset;
> 			 ~~~~~~~^~~~~~~~
>     combine-diff.c:1006:19: note: use array indexing to silence this warning
> 		prefix = COLONS + offset;
> 				^
> 			 &      [       ]
>
> Suppress this by making the suggested change.
>
> Signed-off-by: John Keeping <john@keeping.me.uk>
> ---

This was not lost in the noise.

I thought that this wasn't a serious patch, but your attempt to demonstrate to others why patches trying to squelch clang warnings are not necessarily a good thing to do.

Who is that compiler trying to help with such a warning message? After all, we are writing in C, and clang is supposed to be a C compiler. And adding integer to a pointer to (const) char is a straight-forward way to look at the trailing part of a given string.

> -		prefix = COLONS + offset;
> +		prefix = &COLONS[offset];

In other words, both are perfectly valid C. Why should we make it less readable to avoid a stupid compiler warning?