From: "Jörg Krause" <jkrause@posteo.de>
To: musl@lists.openwall.com
Subject: Re: why is there no __MUSL__ macro?
Date: Fri, 12 Sep 2014 09:35:22 +0200 [thread overview]
Message-ID: <5412A23A.6080503@posteo.de> (raw)
In-Reply-To: <20140911164711.248bf3d7@ncopa-desktop.alpinelinux.org>
On 09/11/2014 04:47 PM, Natanael Copa wrote:
> On Thu, 11 Sep 2014 13:00:09 +0200
> Jörg Krause <jkrause@posteo.de> wrote:
>
>> Hi,
>>
>> I am trying to add support for the musl toolchain to FFmpeg.
>>
>> FFmpeg needs support for library features defined in POSIX.1-2001 with
>> XSI extension and the standards below. Currently configure probes the
>> host and target libc by checking for defined macros like __GLIBC__ and
>> __UCLIBC__. In case of glibc and uclibc it sets -D_XOPEN_SOURCE=600
>> properly.
>>
>> After this it checks for some combinations of hardware and the probed
>> libc to set some more compile options, if necessary.
>>
>> I know that musl does not have a macro __MUSL__ and I have read the
>> explanation. However, I don't understand what's meant by "[..] it's a
>> bug to assume a certain implementation has particular properties rather
>> than testing." and how does it affect the way FFmpeg probes for the libc.
>>
>> What could be a solution which supports musl?
>>
>> Many thanks!
>> Jörg
> This is what we do on alpine linux:
> http://git.alpinelinux.org/cgit/aports/tree/main/ffmpeg/fix-defines.patch
>
> --- ffmpeg-1.2.2.orig/libavutil/error.c
> +++ ffmpeg-1.2.2/libavutil/error.c
> @@ -17,6 +17,7 @@
> */
>
> #undef _GNU_SOURCE
> +#define _XOPEN_SOURCE 600
> #include "avutil.h"
> #include "avstring.h"
> #include "common.h"
>
Hi Natanal,
I had a look to alpine already. I submitted this patch to FFmpeg, but
building FFmpeg with my configuration libavutils/error.c is not the only
file which needs a feature test macro. The people of FFmpeg did not like
the idea to have a lot of test macros in there source so I stopped with
this solution and looked for a way to adopt the musl toolchain to their
configure file.
next prev parent reply other threads:[~2014-09-12 7:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-11 11:00 Jörg Krause
2014-09-11 11:09 ` Laurent Bercot
2014-09-11 11:17 ` Szabolcs Nagy
2014-09-11 12:02 ` Jörg Krause
2014-09-11 12:38 ` Szabolcs Nagy
2014-09-11 13:33 ` Jörg Krause
2014-09-11 14:48 ` Szabolcs Nagy
2014-09-11 14:30 ` Christian Neukirchen
2014-09-11 11:17 ` Jens
2014-09-11 12:24 ` Jörg Krause
2014-09-11 14:53 ` Isaac Dunham
2014-09-12 7:39 ` Jörg Krause
2014-09-11 14:47 ` Natanael Copa
2014-09-12 7:35 ` Jörg Krause [this message]
2014-09-12 15:37 ` Rich Felker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5412A23A.6080503@posteo.de \
--to=jkrause@posteo.de \
--cc=musl@lists.openwall.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/musl/
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).