[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[khoja]

khoja  added the comment:

I had an issue with yocto warrior and zeus branch for target simulation 
Qemu_x86. 
I did a report http://bugzilla.yoctoproject.org/show_bug.cgi?id=13842

Thank you to let me know what you think about It.

--
nosy: +medhi
type:  -> compile error
versions:  -Python 3.8

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Matthias Schoepfer]

Matthias Schoepfer  added the comment:

Hi Matthias,

thanks for clarification. Maybe I am under a totally wrong impression, but to 
me is having soft float comparable to not having some special SSE instruction 
sets with x86. You are missing some instructions, that your code may or may not 
need, and the compiler replaces them with some other, not hardware accelerated 
functions. 

To what extend is the handcrafted version better than the one, autotools are 
providing? 

I really like to learn here. 

Many thanks already!

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Matthias Klose]

Matthias Klose  added the comment:

You misunderstand. The GNU triplets are ambiguous. mips 32bit big endian soft 
float, and mips 32bit big endian hard float are *not* ABI compatible, but map 
to the same GNU triplet.

The check *is* cross compiler aware, it's run with the target 
preprocessor/compiler.

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Matthias Schoepfer]

Matthias Schoepfer  added the comment:

Hi Matthias,

thanks for your comment. I am not sure, if I understand correctly or if it is 
really the problem here. So, if you take a look at the patch, or at the current 
version of configure.ac right now, there is s section:

AC_MSG_CHECKING([for the platform triplet based on compiler characteristics])

There is a handcrafted C Program (well, rather C-Preprocessor), which tries to 
guess, for what Platform the compiler is used for. The initial problem with my 
platform is this line:

# elif defined(__mips_hard_float)

The reason beeing, on mips soft float, __mips_hard_float is not defined. But 
the triplet should be mips-linux-gnu. Otherwise, the build will fail later down 
the road. 

One could add || defined (__mips_soft_float) to fix this issue. Indeed, that 
was my first patch. But I was not really satisfied. I think, using a custom C 
program for finding out the target triplet is generally not the right approach, 
because, you will always miss an architecture or fail to correctly guess the 
triplet (my guess). I think, it is much better, to rely on autotools for this. 
At the end of the day, autotools where made for that purpose, right? 
So I replaced the whole program with AC_CANONICAL_TARGET. It should always do 
the right thing *and* is Cross-Compiler aware. In the end, the triplet is 
mips-linux-gnu. It also removes lots of hard to maintain code (seems, like 
nobody really knows its internals?!). 

My trouble is, that I do not know, what other side effects this might have. On 
the latest release of yocto, my patch is used, and at least, I am not aware of 
any problems, but that does not mean, that there are none... 

Regards,
   Matthias

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Matthias Klose]

Matthias Klose  added the comment:

The idea with the extension names is to have different names for different 
ABIs. See https://wiki.debian.org/Multiarch/Tuples for the list of ABIs that 
are "known", or documented.

mips-linux-gnu is documented as MIPS32r2+FPXX, which is a different ABI than 
MIPS32r2 apparently, and not compatible, so it should have a different name.

Other architectures like arm-linux-gnueabi and arm-linux-gnueabihf have the 
hard/soft difference encode in their GNU triplet name, and apparently nobody 
did that for mips.

One solution would be to define a mips-linux-gnusf Multiarch name, which then 
would be different than the GNU triplet.  Note that there's no "authority" to 
define the Multiarch names, however in most cases the GNU quadruplet without 
the vendor is chosen as the MA name.

Other solutions could be to define no MA name, or go with your solution, just 
ignoring things. I'd still prefer something defining a name for this ABI.

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Matthias Klose]

Matthias Klose  added the comment:

I'll get back on this

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Matthias Schoepfer]

Matthias Schoepfer  added the comment:

Hi!

I submitted this patch, it even is now on yocto zeus. Any progress, will 
someone review it?! 

Thanks and Regards,

Matthias

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[SilentGhost]

Change by SilentGhost :


--
nosy: +doko

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Roundup Robot]

Change by Roundup Robot :


--
pull_requests: +13107

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[SilentGhost]

SilentGhost  added the comment:

Matthias, would you be able to convert the patch into a Github PR? There are 
guidelines available at https://devguide.python.org/pullrequest/

--
nosy: +SilentGhost
stage:  -> patch review
versions: +Python 3.8

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue36852] Python3.7.2 fails to cross-compile (yocto / openembedded) when target is mips softfloat

[Matthias Schoepfer]

New submission from Matthias Schoepfer :

Python 3.7.2 fails to cross compile for yocto / openembedded when target is 
mips softfloat, because the OS triple is not detected correctly by 
configure.ac. The configure script magic just catches for __mips__hard_float 
defines, but I guess, __mips__soft_float also indicates a mips architecture. 

Added patch

--
components: Cross-Build
files: 0001-fixing-finding-of-triplet-on-softfloat-mips.patch
keywords: patch
messages: 341894
nosy: Alex.Willmer, mschoepf
priority: normal
severity: normal
status: open
title: Python3.7.2 fails to cross-compile (yocto / openembedded) when target is 
mips softfloat
versions: Python 3.7
Added file: 
https://bugs.python.org/file48318/0001-fixing-finding-of-triplet-on-softfloat-mips.patch

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com