Mailman 3 August 2016 - cython-devel

cygdb: no debug files were found
by Nathan Goldbaum Sept. 14, 2016

Sept. 14, 2016

Hi all, I'm following the directions in the link below to debug some cython code using cygdb: http://docs.cython.org/src/userguide/debugging.html Unfortunately, when I try to actually debug my program using cygdb, I get a "no debug files were found" error. It looks like the error is getting raised here: https://github.com/cython/cython/blob/master/Cython/Debugger/Cygdb.py#L33 So for some reason the "cython_debug" folder isn't being generated at build time. I tried to follow the directions closely, you can see the notes I put together during the installation process here: https://bpaste.net/show/6b11f815d449 Unfortunately the library I'm trying to debug (yt: bitbucket.org/yt_analysis/yt) uses a somewhat nonstandard build setup based on numpy distutils, and I suspect that is breaking some of the assumptions that went into the cygdb instructions in the cython docs. Does anyone have any idea what went wrong here? For now I'm going to fall back to regular gdb, and debug the autogenerated cython sources. Thanks for your help, Nathan Goldbaum

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Minor issue with running tests and -Wlong-long
by Erik Bray Sept. 5, 2016

Sept. 5, 2016

Hello, As some of you already know I've been doing some work on Cython on Cygwin [in the process I I'm constantly mixing the two up in speech, but maybe in writing I'll do better :)]. There are several issues with the tests on Cygwin, and that's one thing I'll work on. But a major annoyance I've encountered when running any tests is a huge number of warnings from gcc such as: embray@PC-pret-47 ~/src/cython $ CFLAGS="-O0" ./runtests.py -vv --no-cpp addloop Python 2.7.10 (default, Jun 1 2015, 18:05:38) [GCC 4.9.2] Running tests against Cython 0.24 f68b5bd0fa620d0dc26166bffe5fe42d94068720 Backends: c runTest (__main__.CythonRunTestCase) compiling (c) and running addloop ... === C/C++ compiler error output: === In file included from /usr/include/python2.7/Python.h:58:0, from addloop.c:4: /usr/include/python2.7/pyport.h:69:27: warning: ISO C90 does not support ‘long long’ [-Wlong-long] #define PY_LONG_LONG long long ^ /usr/include/python2.7/pyport.h:793:34: note: in definition of macro ‘PyAPI_FUNC’ # define PyAPI_FUNC(RTYPE) RTYPE ^ /usr/include/python2.7/intobject.h:46:21: note: in expansion of macro ‘PY_LONG_LONG’ PyAPI_FUNC(unsigned PY_LONG_LONG) PyInt_AsUnsignedLongLongMask(PyObject *); ^ In file included from /usr/include/python2.7/Python.h:58:0, from addloop.c:4: ... And so on. For now an easy workaround is to add -Wno-long-long to the compiler flags. But I was curious why I was seeing this in Cygwin but not on my Ubuntu system, and here's why: In runtests.py there is a check https://github.com/cython/cython/blob/master/runtests.py#L829 if self.language=='c' and compiler='gcc': ext_compile_flags.extend(['-std=c89', '-pedantic']) where in this case `compiler` is assigned `sysconfig.get_config_var('CC')`. On my Linux system this expands to "x86_64-linux-gnu-gcc -pthread". Whereas on Cygwin (and probably many other systems) it expands simply to "gcc". I'm guessing that to do what it intended the above line should read "and 'gcc' in compiler". But this also raises the question: Why are the tests run with these flags? If Python was configured with HAVE_LONG_LONG, then these warnings will be inevitable. Thanks, Erik

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RFC: an inline_ function that dumps c/c++ code to the code emitter
by Jason Newton Aug. 23, 2016

Aug. 23, 2016

Accidentally posted to an already-opened tab for the cython-users ML yesterday, moving to here. Following up from a github opened issue here: https://github.com/cython/cython/issues/1440 I was hoping we could give a way to drop straight into C/C++ inside of Cython pyx files. Why? -It [helps] avoid needing to declare every class/function in cython, a somewhat daunting/impossible task that I think everyone hates. Have you libraries like Eigen or others that use complex template based techniques? How about those with tons of [member] functions to boot or getting C++ inheritance involved. -It works around having the Cython compiler know about all of C++'s nuances - as an advanced C++ developer these are painful and it is a 2nd class citizen to Cython's simpler C-support - that's no good. Just right now I was bitten by yet another template argument bug and it's clear C++ template arguments have been kind of dicy since support appeared. -It would allow single source files - I think this is important for runtime compiled quasi-JIT/AOC fragments, like OpenCL/PyOpenCL/PyCUDA provide The idea is that Cython glue makes the playing field for extracting data easy, but that once it's extracted to a cdef variable for instance, cython doesn't need to know what happens. Maybe in a way sort of like the GCC asm extension. Hopefully simpler variable passing though. The alternative to not having this construct is a concrete wall. I'll have to segment up files for C++ for the rest of time until I get function forms that Cython can handle. At that point I just say screw it and use boost python. Of course cython does the definitions, data extraction, and compilation so much easier than boost.python. It would be a shame to not consider this plight C++ developers have been cornered into and you can't say the C++ libraries are broken, it is the strategy Cython is taking that cannot work. I did some examination of how this could be implemented - my idea was to base on the print/exec statements handling and simply emit their arguments from the Nodes to the code generator. Proposing inline_c or inline_ as the statement. Such a statement could be used to do macros, pull in includes, and modify/declare c-variables. -Jason

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Fwd: Re: [Speed] New benchmark suite for Python
by Stefan Behnel Aug. 18, 2016

Aug. 18, 2016

This could replace the benchmark runs that we had on Jenkins. Stefan -------- Forwarded Message -------- Subject: Re: [Speed] New benchmark suite for Python Date: Wed, 17 Aug 2016 23:47:29 -0500 From: Zachary Ware <zachary.ware+pydev(AT)gmail.com> To: speed(AT)python.org On Wed, Aug 17, 2016 at 7:37 PM, Victor Stinner wrote: > PyPy, Pyston, Pyjion, Numba, etc. : Hey! it's now time to start to > take a look at my project and test it ;-) Tell me what is broken, what > is missing, and I will try to help you to move your project to this > new benchmark suite! Also, if you're interested in having your interpreter benchmarked on speed.python.org, contact me with clear instructions (preferably in the form of a shell or Python script) on how to build, test, install, and invoke your interpreter from a fresh Ubuntu 16.04 installation. As an example, here's an untested version for CPython 3.x: #!/bin/sh # set up dependencies sudo apt-get build-dep -y python3 sudo apt-get install -y --no-install-recommends mercurial # get the code hg clone https://hg.python.org/cpython cd cpython # build ./configure --prefix=/opt/python/default make -j12 # test make buildbottest TESTOPTS=-j12 # install make install # invoke /opt/python/default/bin/python3 I don't know when I'll have a chance to work on it, but I'd like to get as many projects as possible benchmarked on speed.python.org. Victor: Thanks for getting the new repository set up and for all your work on the new runner! I'm looking forward to trying it out. -- Zach _______________________________________________ Speed mailing list https://mail.python.org/mailman/listinfo/speed

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Cython on GitHub
by Robert Bradshaw Aug. 18, 2016

Aug. 18, 2016

All of of Cython serving infrastructure, save the jenkins buildbot, has been moved to GitHub. (Documentation is served via readthedocs.org, and tarballs served from pypi, built from GitHub head). Each trac ticket has been migrated to a github issue. I have updated/redirected what links I can. As for backups, I created https://github.com/cython/cython-issues/tree/master to store the non-repository data, which will be periodically updated. Note that the original trac data (minus session/user info) is there as well. I will also be locally cloning all the repositories in the cython organization, and would recommend at least one other person do the same. - Robert

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Migration of tickets from trac to github
by Robert Bradshaw Aug. 17, 2016

Aug. 17, 2016

Please see https://github.com/robertwb/issues-import-test/issues/ as to what this would look like. (This is a partial import, due to github API rate limiting issues.) Unless something looks terribly wrong, I'll start the real migration shortly. - Robert

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Any way to embed C/C++ in a single source compilation of a pyx file?
by Jason Newton Aug. 14, 2016

Aug. 14, 2016

I just added inline_module's and submitted a PR today here: https://github.com/cython/cython/pull/555 My intent was something like OpenCL's JIT/AOC compilation (PyCUDA/PyOpenCL also work this way) which is simple and high performance, and I saw cython had this capability and just needed a little bit of a wrapper to expose it better. But after trying to put it into use for my own problems, where I would regularly want to use Eigen or other integration problems I realized I'd still have to write and save [many] code fragments to other files which cythonize-ing would read in through includes, when you need to work with something that doesn't have a cython cimport module. This is pretty ugly and doesn't achieve the easier flow that I had wanted. However if there was a way to embed C/C++ inside a pyx file (that is inline to strings), there would be no such issue. I submitted an issue here https://github.com/cython/cython/issues/556 but I was hoping to get the ball rolling if the ML is where the development conversations happen - it's not clear to me right now the best place for the Cython project to request this from, so sorry to cross post. Regards, -Jason

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long_double_to_float_int failure on s390x (BE) (0.24.1)
by Yaroslav Halchenko Aug. 11, 2016

Aug. 11, 2016

Dear Cython ppl, Didn't spot any obvious commit/log since 0.24.1 so decided just to report: full build log: https://buildd.debian.org/status/fetch.php?pkg=cython&arch=s390x&ver=0.24.1… 1 test has failed on s390x (only). Quick resolution would help to assure cython's healthy status in debian coming to a freeze point. ====================================================================== FAIL: long_double_to_float_int (line 195) (int_float_builtins_as_casts_T400.__test__) Doctest: int_float_builtins_as_casts_T400.__test__.long_double_to_float_int (line 195) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/python2.7/doctest.py", line 2226, in runTest raise self.failureException(self.format_failure(new.getvalue())) AssertionError: Failed doctest test for int_float_builtins_as_casts_T400.__test__.long_double_to_float_int (line 195) File "/«PKGBUILDDIR»/build/work-dir/run/c/int_float_builtins_as_casts_T400/int_float_builtins_as_casts_T400.so", line unknown line number, in long_double_to_float_int (line 195) ---------------------------------------------------------------------- File "/«PKGBUILDDIR»/build/work-dir/run/c/int_float_builtins_as_casts_T400/int_float_builtins_as_casts_T400.so", line ?, in int_float_builtins_as_casts_T400.__test__.long_double_to_float_int (line 195) Failed example: long_double_to_float_int(4.1) Expected: 4.0 Got: 0.0 ---------------------------------------------------------------------- File "/«PKGBUILDDIR»/build/work-dir/run/c/int_float_builtins_as_casts_T400/int_float_builtins_as_casts_T400.so", line ?, in int_float_builtins_as_casts_T400.__test__.long_double_to_float_int (line 195) Failed example: long_double_to_float_int(-4.1) Expected: -4.0 Got: 0.0 ---------------------------------------------------------------------- File "/«PKGBUILDDIR»/build/work-dir/run/c/int_float_builtins_as_casts_T400/int_float_builtins_as_casts_T400.so", line ?, in int_float_builtins_as_casts_T400.__test__.long_double_to_float_int (line 195) Failed example: long_double_to_float_int(4) Expected: 4.0 Got: 0.0 ---------------------------------------------------------------------- Ran 9957 tests in 4237.557s FAILED (failures=1, skipped=2) -- Yaroslav O. Halchenko Center for Open Neuroscience http://centerforopenneuroscience.org Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755 Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419 WWW: http://www.linkedin.com/in/yarik

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Cython docs are for version 0.15pre
by Jeroen Demeyer Aug. 1, 2016

Aug. 1, 2016

The page https://cython.readthedocs.io/en/latest/ has the documentation for Cython version 0.15pre. How did that happen???

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