[yocto] perl 5.22 and 32 bit targets

[Gary Thomas]

On 2016-03-23 10:48, Jens Rehsack wrote:
>
>> Am 23.03.2016 um 10:14 schrieb Jens Rehsack <rehsack at gmail.com>:
>>
>>>
>>> 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?
>
> I give it a quick shot and got:
>
> ../../arm-poky-linux-gnueabi-libtool  --tag=CC   --mode=compile arm-poky-linux-gnueabi-gcc  -march=armv7-a -marm  -mthumb-interwork -mfloat-abi=hard -mfpu=neon -mtune=cortex-a9 --sysroot=/homes/sno/fsl-release-bsp/ornithologen-kann-man-mit-voegeln-eine-freude-machen/tmp/sysroots/curie -DHAVE_CONFIG_H -I. -I../../config -I../../common-src -I../../common-src -I../../xfer-src -I../../gnulib -I../../ndmp-src -I/homes/sno/fsl-release-bsp/ornithologen-kann-man-mit-voegeln-eine-freude-machen/tmp/sysroots/x86_64-linux/usr/lib/perl-native/perl/5.22.1/CORE   -fno-strict-aliasing -D_GNU_SOURCE -pthread -I/homes/sno/fsl-release-bsp/ornithologen-kann-man-mit-voegeln-eine-freude-machen/tmp/sysroots/curie/usr/include/glib-2.0 -I/homes/sno/fsl-release-bsp/ornithologen-kann-man-mit-voegeln-eine-freude-machen/tmp/sysroots/curie/usr/lib/glib-2.0/include -DSWIG  -O2 -pipe -g -feliminate-unused-debug-types -fipa-pta -ftree-partial-pre -ftree-loop-distribution -ftree-loop-distribute-patterns -fgcse-afte
 r
-reload -fgcse-sm -fgcse-las  -fno-strict-aliasing  -c -o xferwrap.lo xferwrap.c
>
> Do you see the "-I/homes/sno/fsl-release-bsp/ornithologen-kann-man-mit-voegeln-eine-freude-machen/tmp/sysroots/x86_64-linux/usr/lib/perl-native/perl/5.22.1/CORE" ?
>
> Any further blames of perl-5.22? :)

I'm not sure what you are getting at here.  Indeed it is supposed to be
using perl-5.22.1 for everything.  The version 5.22.0 in meta-amanda layer
is just for testing and should not be used at the moment.

All of my comparisons and testing (see instructions in the README) are
for perl-5.22.1 only and in fact I've only been using the bits from bitbake/OE
and not building that any more (I found that it wasn't necessary - one only
needs to build amanda on the target)

Sorry for the confusion.


-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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