Issue 21668: The select and time modules uses libm functions without linking against it (original) (raw)
Created on 2014-06-05 12:56 by fornwall, last changed 2022-04-11 14:58 by admin. This issue is now closed.
Messages (15)
Author: Fredrik Fornwall (fornwall) *
Date: 2014-06-05 12:56
The select and time modules use functions from libm, but do not link against it.
- selectmodule.c calls ceil(3) in pyepoll_poll()
- timemodule.c calls fmod(3) and floor(3) in floatsleep()
Author: Fredrik Fornwall (fornwall) *
Date: 2014-06-05 12:57
Note: This causes problems at least when running on android, where the system is unable to find the symbols when loading the modules at runtime.
Author: Matt Frank (WanderingLogic) *
Date: 2014-10-27 15:54
Additionally,
- audioop calls floor()
- _ctypes_test calls sqrt()
Patch attached.
Author: STINNER Victor (vstinner) * 
Date: 2014-10-27 15:58
audioop_ctypes_test_link_with_libm.patch
libraries=['m'])
Why not using math_libs here? It would also be nice to add a comment explaining why libm is needed in each module.
Can someone please combine both patches?
Author: Matt Frank (WanderingLogic) *
Date: 2014-10-27 17:34
audioop_ctypes_test_link_with_libm.patch
libraries=['m'])Why not using math_libs here?
math_libs is defined in detect_modules(). But the _ctypes_test extension is defined in a different function: detect_ctypes().
The other option, would be to define math_libs=['m'] directly above this line and then use it once. I didn't think that added clarity, but I'd be happy to do it that way if it fits better with standard style.
It would also be nice to add a comment explaining why libm is needed in each module.
Done.
Can someone please combine both patches?
Done.
Author: (yan12125) *
Date: 2015-11-26 11:25
Bump. For rev c6930661599b timemodule.c and selectmodule.c no longer calls libm functions, while audioop.c and _ctypes_test.c still do. I have my updated patch here based on previous patches. Note that the introduction of detect_math_libs() is my naive try. Its naming and position in setup.py may need more consideration.
Here's the result before and after my patch.
Before: shell@GT-N7000:/data/local/tmp $ python3 Python 3.6.0a0 (default:6a8fbb97c8d8+, Nov 26 2015, 18:42:29) [GCC 4.9 20140827 (prerelease)] on linux Type "help", "copyright", "credits" or "license" for more information.
import select import time import audioop Traceback (most recent call last): File "", line 1, in ImportError: dlopen failed: cannot locate symbol "floor" referenced by "audioop.cpython-36m-arm-linux-gnueabi.so"... import _ctypes_test Traceback (most recent call last): File "", line 1, in ImportError: dlopen failed: cannot locate symbol "sqrt" referenced by "_ctypes_test.cpython-36m-arm-linux-gnueabi.so"...
After:
shell@GT-N7000:/data/local/tmp $ python3 Python 3.6.0a0 (default:c6930661599b+, Nov 26 2015, 19:10:15) [GCC 4.9 20140827 (prerelease)] on linux Type "help", "copyright", "credits" or "license" for more information.
import time import selectr Traceback (most recent call last): File "", line 1, in ImportError: No module named 'selectr' import select import audioop import _ctypes_test
Tested on Samsung Galaxy Note GT-N7000 with my custom build of CyanogenMod 11.0
Author: (yan12125) *
Date: 2015-11-26 11:27
Well, the hg revision of Python in two tests are different, because I hg pull -u each time I build.
Author: Xavier de Gaye (xdegaye) * 
Date: 2016-04-19 07:54
The _datetime module also calls functions in libm: delta_new() uses round() and accum() uses modf().
The attached patch updates setup.py for all the modules that use libm.
Author: (yan12125) *
Date: 2016-04-19 08:03
The approach with a helper function is better. See https://github.com/yan12125/python3-android/blob/038271d/mk/python/modules-link-libm.patch.
By the way, I have verified there are no libraries referencing libm functions with https://github.com/yan12125/python3-android/blob/cpython-hg/devscripts/import_all.py
Author: Roundup Robot (python-dev)
Date: 2016-04-19 13:58
New changeset f92fea23161d by Victor Stinner in branch '3.5': setup.py: add missing libm dependency https://hg.python.org/cpython/rev/f92fea23161d
New changeset 3a9b47b062b9 by Victor Stinner in branch 'default': Merge 3.5: Issue #21668 https://hg.python.org/cpython/rev/3a9b47b062b9
Author: STINNER Victor (vstinner) *
Date: 2016-04-19 14:00
I pushed ext_modules_libm.patch with the helper function proposed by Chi Hsuan Yen in https://github.com/yan12125/python3-android/blob/038271d/mk/python/modules-link-libm.patch.
Tell me if it's not enough. I hope that it will make CPython a little bit more portable ;-)
Author: Xavier de Gaye (xdegaye) *
Date: 2016-04-20 07:14
The patch should be acknowledged in Misc/NEWS to Chi Hsuan Yen and not to me.
Author: Roundup Robot (python-dev)
Date: 2016-04-20 07:58
New changeset f76753f26982 by Victor Stinner in branch 'default': Issue #21668: Fix author of the patch. https://hg.python.org/cpython/rev/f76753f26982
Author: Roundup Robot (python-dev)
Date: 2016-04-20 08:02
New changeset 7530caa5ed1a by Victor Stinner in branch 'default': Issue #21668: Add also Chi Hsuan Yen to Misc/ACKS https://hg.python.org/cpython/rev/7530caa5ed1a
Author: STINNER Victor (vstinner) *
Date: 2016-04-20 08:02
Xavier de Gaye: "The patch should be acknowledged in Misc/NEWS to Chi Hsuan Yen and not to me."
Oh sorry. I see 4 authors in attached patches, I picked the latest. Thank you to all authors for your contribution on this issue ;-) I fixed the author in Misc/NEWS.
History
Date
User
Action
Args
2022-04-11 14:58:04
admin
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github: 65867
2016-04-20 08:02:15
vstinner
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messages: +
2016-04-20 08:02:13
python-dev
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messages: +
2016-04-20 07:58:21
python-dev
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messages: +
2016-04-20 07:14:16
xdegaye
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messages: +
2016-04-19 14:00:07
vstinner
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status: open -> closed
resolution: fixed
messages: +
versions: + Python 3.6, - Python 3.4
2016-04-19 13:58:47
python-dev
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nosy: + python-dev
messages: +
2016-04-19 08:03:57
yan12125
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messages: +
2016-04-19 07:54:18
xdegaye
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files: + ext_modules_libm.patch
nosy: + xdegaye
messages: +
2015-11-26 11:27:38
yan12125
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messages: +
2015-11-26 11:25:35
yan12125
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files: + python-hg-modules-link-libm.patch
nosy: + yan12125
messages: +
2015-02-23 14:38:36
vstinner
link
2014-10-27 17:34:48
WanderingLogic
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files: + time_select_audioop_ctypes_test_link_with_libm.patch
messages: +
2014-10-27 15:58:49
vstinner
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messages: +
2014-10-27 15:57:51
WanderingLogic
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nosy: + freakboy3742
2014-10-27 15:54:51
WanderingLogic
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messages: +
2014-10-27 15:46:24
WanderingLogic
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files: + audioop_ctypes_test_link_with_libm.patch
nosy: + WanderingLogic
2014-06-05 13🔞30
vstinner
set
nosy: + vstinner
2014-06-05 12:57:24
fornwall
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messages: +
2014-06-05 12:56:33
fornwall
create