[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-trivial] Fix build break during configuration on musl-libc bas
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-trivial] Fix build break during configuration on musl-libc based Linux systems. |
Date: |
Fri, 17 Feb 2017 09:56:27 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 |
On 16/02/2017 18:23, Laszlo Ersek wrote:
> On 02/16/17 17:58, Paolo Bonzini wrote:
>>
>>
>> On 16/02/2017 17:30, Chad Joan wrote:
>>> Hello,
>>>
>>> This is a one-line patch to the configure script that will allow QEMU to be
>>> built on musl-libc based Linux systems. This problem is only noticeable
>>> when QEMU is built with --enable-curses.
>>>
>>> Detailed reading material if you want to know where this came from:
>>> https://bugs.gentoo.org/show_bug.cgi?id=609364
>>
>> Hi,
>>
>> can you explain exactly which function is missing without
>> -D_XOPEN_SOURCE=500? If it is curses' wide-char functions, why does it
>> fail with musl but not with glibc? Is _XOPEN_SOURCE always defined by
>> glibc if you have _D_GNU_SOURCE?
>
> It is not necessarily auto-defined, but the effect is "as if".
Ok, so the bug is that glibc _does_ auto-define _XOPEN_SOURCE:
#ifdef _GNU_SOURCE
# undef _ISOC95_SOURCE
# define _ISOC95_SOURCE 1
# undef _ISOC99_SOURCE
# define _ISOC99_SOURCE 1
# undef _ISOC11_SOURCE
# define _ISOC11_SOURCE 1
# undef _POSIX_SOURCE
# define _POSIX_SOURCE 1
# undef _POSIX_C_SOURCE
# define _POSIX_C_SOURCE 200809L
# undef _XOPEN_SOURCE
# define _XOPEN_SOURCE 700
# undef _XOPEN_SOURCE_EXTENDED
# define _XOPEN_SOURCE_EXTENDED 1
# undef _LARGEFILE64_SOURCE
# define _LARGEFILE64_SOURCE 1
# undef _DEFAULT_SOURCE
# define _DEFAULT_SOURCE 1
# undef _ATFILE_SOURCE
# define _ATFILE_SOURCE 1
#endif
and ncursesw looks for _XOPEN_SOURCE exclusively:
#ifndef NCURSES_WIDECHAR
#if defined(_XOPEN_SOURCE_EXTENDED) || (defined(_XOPEN_SOURCE) &&
(_XOPEN_SOURCE - 0 >= 500))
#define NCURSES_WIDECHAR 1
#else
#define NCURSES_WIDECHAR 0
#endif
#endif /* NCURSES_WIDECHAR */
So I do think that if musl wants to support _GNU_SOURCE, it should also
auto-define;
however it doesn't, see
https://git.musl-libc.org/cgit/musl/tree/include/features.h.
Alternatively, ncurses should be patched to look at _GNU_SOURCE in addition to
_XOPEN_SOURCE and _XOPEN_SOURCE_EXTENDED.
In any case, it's not a QEMU bug. Other packages likely are going to have the
same
issue, and fixing all of them is the wrong course of action.
Paolo
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., (continued)
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Eric Blake, 2017/02/20
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Eric Blake, 2017/02/17
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Chad Joan, 2017/02/19
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Eric Blake, 2017/02/20
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Markus Armbruster, 2017/02/21
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Peter Maydell, 2017/02/21
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., John Snow, 2017/02/17
- Re: [Qemu-trivial] Fix build break during configuration on musl-libc based Linux systems., Paolo Bonzini, 2017/02/17
- Re: [Qemu-trivial] Fix build break during configuration on musl-libc based Linux systems.,
Paolo Bonzini <=
- Re: [Qemu-trivial] Fix build break during configuration on musl-libc based Linux systems., Laszlo Ersek, 2017/02/17
- Re: [Qemu-trivial] Fix build break during configuration on musl-libc based Linux systems., Paolo Bonzini, 2017/02/17
- Re: [Qemu-trivial] Fix build break during configuration on musl-libc based Linux systems., Chad Joan, 2017/02/17
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Peter Maydell, 2017/02/17
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Paolo Bonzini, 2017/02/17
- Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Peter Maydell, 2017/02/17
Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Eric Blake, 2017/02/16
Re: [Qemu-trivial] [Qemu-devel] Fix build break during configuration on musl-libc based Linux systems., Peter Maydell, 2017/02/16