linux-kernel - Re: gcc fixed size char array initialization bug

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Message-ID: <p73vebxmysb.fsf@bingen.suse.de>
Date:	02 Aug 2007 23:06:44 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Guennadi Liakhovetski <g.liakhovetski@....de>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: gcc fixed size char array initialization bug - known?

Guennadi Liakhovetski <g.liakhovetski@....de> writes:

> Hi
> 
> I've run across the following gcc "feature":
> 
> 	char c[4] = "01234";
> 
> gcc emits a nice warning
> 
> warning: initializer-string for array of chars is too long
> 
> But do a
> 
> 	char c[4] = "0123";
> and - a wonder - no warning. 

It's required by the C standard.

6.7.8.14 of C99:
``
An array of character type may be initialized by a character string literal, optionally
enclosed in braces. Successive characters of the character string literal (including the
terminating null character if there is room or if the array is of unknown size) initialize the
elements of the array.
''

Note the "if there is room".

I believe the rationale is that it still allows to conveniently initialize 
non zero terminated strings.

-Andi
-
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