[alsa-devel] ["PATCH alsa-lib"] Change snd_dlopen() function to return the error string

[Jaroslav Kysela]

Dne 27.11.2017 v 21:24 Takashi Iwai napsal(a):
> On Mon, 27 Nov 2017 19:19:51 +0100,
> Takashi Sakamoto wrote:
>>
>> Hi Jaroslav,
>>
>> On Nov 27 2017 17:50, Jaroslav Kysela wrote:
>>> The dlopen() function might fail also for another reason than
>>> a missing file, thus return the error string from dlerror().
>>>
>>> Signed-off-by: Jaroslav Kysela <perex at perex.cz>
>>> ---
>>>   include/global.h        |  2 +-
>>>   src/Versions.in         |  5 +++++
>>>   src/conf.c              | 13 ++++++-----
>>>   src/dlmisc.c            | 60 +++++++++++++++++++++++++++++++++++++++----------
>>>   src/hwdep/hwdep.c       |  6 ++---
>>>   src/mixer/simple_abst.c | 10 ++++-----
>>>   src/pcm/pcm_hooks.c     |  8 +++----
>>>   src/pcm/pcm_meter.c     |  6 ++---
>>>   src/rawmidi/rawmidi.c   |  6 ++---
>>>   src/seq/seq.c           |  6 ++---
>>>   src/timer/timer.c       |  6 ++---
>>>   src/timer/timer_query.c |  6 ++---
>>>   12 files changed, 88 insertions(+), 46 deletions(-)
>>
>> Unfortunately, this patch brings build error in my environment (Ubuntu
>> 17.10 amd64, gcc7.2.0 from gcc-7 7.2.0-8ubuntu3).
>>
>> $ ./gitcompile
>> $ make
>> make[2]: Entering directory '/tmp/alsa-lib/src'
>>   CCLD     libasound.la
>> /usr/bin/ld: unable to find version dependency `ALSA_1.1.6'
>> pcm/.libs/libpcm.a(pcm_generic.o): In function `snd1_pcm_generic_hwsync':
>> /tmp/alsa-lib/src/pcm/pcm_generic.c:142: warning:
>> collect2: error: ld returned 1 exit status
>> Makefile:491: recipe for target 'libasound.la' failed
>> make[2]: *** [libasound.la] Error 1
>>
>> At present, I don't know exactly the reason, but I'll start
>> investigating it in next morning (I'd like to have sleep...).
> 
> It's likely a bogus definition in version symbols.
> It has to be a form like:
> 
>   ALSA_1.1.6 {
>     global:
>       @SYMBOL_PREFIX at snd_dlopen;
>   } ALSA_1.1.5;
> 
> while the patch put "ALSA_1.1.6" to both places.

Yes, I forgot to modify src/Versions.in (I modified only src/Versions
for my local build).

> Besides that, I'm scared by the versioned symbols, of which I have
> only a bad memory.

I know, but the major issue that we forgot to apply old symbol versions
to some functions in the past, right ? I don't see any drawback.

I applied this patchset with other configure.ac cleanups. I need to fix
build for python3, but that's a different story.

				Jaroslav

-- 
Jaroslav Kysela <perex at perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.