[yocto] perl 5.22 and 32 bit targets

[Jens Rehsack]

> Am 23.03.2016 um 10:09 schrieb Gary Thomas <gary at mlbassoc.com>:
> 
> On 2016-03-23 09:57, Jens Rehsack wrote:
>> 
>>> Am 23.03.2016 um 09:40 schrieb Gary Thomas <gary at mlbassoc.com>:
>>> 
>>> On 2016-03-23 09:09, Gary Thomas wrote:
>>>> On 2016-03-23 06:36, Khem Raj wrote:
>>>>> On Tue, Mar 22, 2016 at 9:53 PM, Gary Thomas <gary at mlbassoc.com> wrote:
>>>>>> I hope this is the correct place to discuss this problem.  It
>>>>>> is all about a difference in behavior between a program built
>>>>>> using bitbake/OE (only OE-core is needed) vs building the program
>>>>>> on the target hardware itself.
>>>>>> 
>>>>>> I've been struggling with this problem since perl was upgraded
>>>>>> to version 5.22.  I'm working on Amanda (Advanced Maryland Archive
>>>>>> tool) which is written primarily in perl and uses swig interfaces
>>>>>> to access native C functions.  This code works great when using
>>>>>> the previous perl (5.20.x) but fails on all 32 bit targets with
>>>>>> perl 5.22
>>>>>> 
>>>>>> The interesting thing is that if I build Amanda on my target
>>>>>> directly (using SDK tools), it works perfectly even with perl
>>>>>> 5.22, so it seems that there is some [subtle] difference between
>>>>>> building using bitbake/OE than when built on the self-hosted
>>>>>> target.  I've compared the builds and the only thing I could
>>>>>> find (from the output of configure) is a difference in sizeof(off_t)
>>>>>> Sadly, when I tried to adjust this in the OE build, it didn't
>>>>>> make any difference, but perhaps I didn't make this change
>>>>>> correctly or completely.
>>>>> 
>>>>> do you have largefile support turned on ? if you do then it might
>>>>> be detecting it wrongly during configure since we cache it to a
>>>>> non-largefile case
>>>>> 
>>>>> so try to add something like
>>>>> 
>>>>> EXTRA_OECONF += "${@bb.utils.contains('DISTRO_FEATURES', 'largefile',
>>>>> 'ac_cv_sizeof_off_t=8', '', d)}"
>>>>> 
>>>>> while building perl or the affected program and see if that helps
>>>> 
>>>> Thanks for the idea, but that didn't help.  I also forced some CFLAGS
>>>> to match, in particular:
>>>>   -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
>>>> but this didn't make any difference either.
>>>> 
>>> 
>>> On a whim I just tried a little experiment where I took the *.o files
>>> from the perl subdirectory (where all the swig shims live) from a working
>>> (self-hosted) build and moved them to my bitbake/OE build.  I then touched
>>> all the *.o and *.lo files in the perl tree to force a relink. I then ran
>>>  % bitbake amanda -C compile && bitbake core-image-base
>>> to my surprise, amanda works!  So the culprit lies somewhere within the
>>> swig generated glue.  I've tried comparing these files before and I didn't
>>> find anything other than cosmetic differences (mostly comments about the
>>> name of the file processed, etc).  I've added this subtree to "results"
>>> in my github layer in case someone can see what might be relevant.
>>> 
>>> Any ideas what might be different and make this swig generated glue fail?
>>> Note that the swig interface files are rebuilt as part of the build process
>>> and both bitbake/OE and self-hosted are using the same swig version.
>> 
>> I digged a bit through your layer (while my up2date scanner over meta-cpan
>> blocks my build chain :P) and realized that you use perl-5.20.0 as it was
>> in poky. A "simple" downgrade would be more reasonable ... if reason applys
>> here in general :)
> 
> In practice, I am doing that.  However, I want to understand why perl 5.22
> breaks things and get it fixed.

I did a diff between your 5.20 and poky's 5.22 and realize some fixes applied
in 5.22 regarding library path's aren't applied in your copy. Maybe swig relies
on wrong library locations and when we know, we can fix.

So it's maybe not a 5.20 vs. 5.22 problem, it's maybe a weird swig setup problem.

>> When you fail on cross-build and succeed in target build, try to compare the
>> C files and includes (even swig libraries) used.
>> 
>> It smells more like a "wrong source" than a "perl problem" (and even when
>> I never would read any python thread, the same problem would likely occur
>> there, too ^^).
>> 
>> Which perl headers are used in your build? To dig down, more logs would
>> be reasonable ...
> 
> Everything comes from the same sources, same revisions, etc, as I'm using
> either a bitbake/OE build or the embedded (self-hosted) version from the
> same build plus SDK tools.

And your SDK does not include any host tools? Did you prove the intermediate
amanda build files (eg. generated by SWIG) for relicts from wrong source?
Did you check the logs which include directories had been used?

Cheers
--
Jens Rehsack - rehsack at gmail.com

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 842 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <http://lists.yoctoproject.org/pipermail/yocto/attachments/20160323/231a9827/attachment.pgp>