[libvirt] [PATCH v2] build: silence a clang warning in virsh.c

[Ján Tomko]

On 11/19/2013 02:09 AM, Ryota Ozaki wrote:
> Hi Eric,
> 
> Thank you for very kind replying and investigations.
> And I'm sorry I'm slow to react.
> 
> On Tue, Nov 19, 2013 at 1:44 AM, Eric Blake <eblake at redhat.com> wrote:
>> On 11/18/2013 09:03 AM, Eric Blake wrote:
>>
>>>>> The warning happens because rl_readline_name on Mac OS X is still
>>>>> 'char *', while it is 'const char *' on most platforms.
>>>>
>>>> This is the real bug we are working around, not clang.
>>>>
>>
>>>
>>> Again, I think it's better to call out the faulty version of libreadline
>>> with the problem, rather than which compiler chokes on it.
>>
>> I did some history digging.  bash.git is not the world's friendliest git
>> repository (Chet insists on one mega commit per release rather than
>> individual commits per logical change, although he's at least gotten
>> better at weekly patches rather than waiting for major releases) - but
>> in spite of that, it only took me about 10 minutes to prove that
>> rl_readline_name was introduced non-const in bash 2.0.1 (and its
>> corresponding readline version 2.1 in June 1997) and made const in bash
>> 2.0.5 (and its corresponding readline version 4.2, released in Apr
>> 2001).
> 
> I have also dug readline.h. /usr/include/readline/readline.h
> (actually it's a link to ../editline/readline.h) on Mac OS X says that:
> 
>  /*      $NetBSD: readline.h,v 1.30 2009/09/07 21:24:34 christos Exp $   */
> 
>  /*-
>   * Copyright (c) 1997 The NetBSD Foundation, Inc.
>   * All rights reserved.
> 
> So as your investigation found out, the header file seems to come from
> around 1997 (NetBSD 1.2.1?) and not upgraded until now.
> 
> NetBSD of course has migrated to a recent readline (6.2
> according to ftp://ftp.netbsd.org/pub/pkgsrc/current/pkgsrc/devel/readline/README.html).

The lastest readline.h from libedit still uses 'extern char *rl_readline_name:

/*	$NetBSD: readline.h,v 1.34 2013/05/28 00:10:34 christos Exp $	*/

http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libedit/readline/readline.h?rev=1.34&content-type=text/x-cvsweb-markup&sortby=date

Jan

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