f2py broken on some mac systems

[flawrence]

Any use of f2py, e.g. following the examples at http://www.sagemath.org/doc/numerical_sage/f2py.html lead to a crash:

error: Command "sage_fortran -Wall -shared /var/folders/LQ/LQFRAKFTGCCurtDiHcxv1k++-5I/-Tmp-
/tmpisjCMl/var/folders/LQ/LQFRAKFTGCCurtDiHcxv1k++-5I/-Tmp-
/tmpisjCMl/src.macosx-10.6-i386-2.6/fortran_module_0module.o 
/var/folders/LQ/LQFRAKFTGCCurtDiHcxv1k++-5I/-Tmp-
/tmpisjCMl/var/folders/LQ/LQFRAKFTGCCurtDiHcxv1k++-5I/-Tmp-
/tmpisjCMl/src.macosx-10.6-i386-2.6/fortranobject.o 
/var/folders/LQ/LQFRAKFTGCCurtDiHcxv1k++-5I/-Tmp-
/tmpisjCMl/Users/felix/.sage/temp/<my domain name>/52076/tmp_0.o -L"Using built-in specs.
/Applications/sage-4.3.1.rc1/local/bin/../lib/gcc/i686-apple-darwin8/4.2.3/x86_64" 
-lgfortran -o ./fortran_module_0.so" failed with exit status 1

i686-apple-darwin8-gfortran-4.2: no input files
i686-apple-darwin8-gfortran-4.2: no input files
i686-apple-darwin8-gfortran-4.2: unrecognized option '-shared'
i686-apple-darwin8-gfortran-4.2: no input files
i686-apple-darwin8-gfortran-4.2: unrecognized option '-shared'
i686-apple-darwin8-gfortran-4.2: no input files
i686-apple-darwin8-gfortran-4.2: no input files
i686-apple-darwin8-gfortran-4.2: no input files
i686-apple-darwin8-gfortran-4.2: unrecognized option '-shared'
i686-apple-darwin8-gfortran-4.2: no input files
i686-apple-darwin8-gfortran-4.2: unrecognized option '-shared'
i686-apple-darwin8-gfortran-4.2: no input files
Using built-in specs.
Target: i686-apple-darwin8
Configured with: /Builds/unix/gcc/gcc-4.2/configure --prefix=/usr/local 
--mandir=/share/man --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ 
--build=i686-apple-darwin8 --host=i686-apple-darwin8 --target=i686-apple-
darwin8 --enable-languages=fortran
Thread model: posix
gcc version 4.2.3

<SNIP>

This is using 4.3.1rc1 on 10.6, 64-bit.

The problem is that local/lib/python2.6/site-packages/numpy/distutils/fcompiler/gnu.py adds a "-shared" flag when linking, even though OS X doesn't support it.

[mvngu]

An updated spkg with Felix's patch is available at

 http://sage.math.washington.edu/home/mvngu/spkg/standard/numpy/version2/numpy-1.3.0.p3.spkg

This ticket might clash with #7831.

[drkirkby]

Has this been checked on Solaris?

There's general information about building on Solaris at

 http://wiki.sagemath.org/solaris

Information specifically for 't2' at

 http://wiki.sagemath.org/devel/Building-Sage-on-the-T5240-t2

Both the source (4.3.0.1 is the latest to build on Solaris) and a binary which will run on any SPARC can be found at http://www.sagemath.org/download-source.html

Dave

[flawrence]

I haven't checked this on Solaris, but it shouldn't affect behaviour on any platform other than OS X. All this patch does is substitute the options "-undefined dynamic_lookup -bundle" for "-shared" under OS X, since on OS X the compiler doesn't support "-shared".

This platform-check and substitution is already being done elsewhere in the file (in the Sage_FCompiler class), but was not being done in Sage_FCompiler_1, so it's a pretty innocuous patch.

Cheers, Felix

[drkirkby]

The title says this breaks on "on some mac systems", but the patch is applied on all Mac systems (well, all running OS X). Is that wise?

It would be good if it could be tested on Solaris too, as often what are perceived as pretty innocuous patches do break on some systems.

[flawrence]

Mac OS X (Darwin) compilers do not support the "-shared" option. The class Sage_FCompiler_1 currently calls compilers on all platforms using the "-shared" option. So whenever this class is used on Mac, it fails. On my computer, this led to f2py failing. This is a five line patch (plus documentation) that changes the compiler options on Mac to be in line with those already used in Sage_FCompiler, while leaving the compiler options on other platforms such as Solaris unchanged. If you'd like to check it on Solaris, then go ahead, but the patch was intentionally written to avoid changing behaviour on platforms other than OS X.

This breaks "on some mac systems" - f2py is broken on my 64-bit sage, but seems to be working on 32-bit mac systems without this patch. My guess is that 32-bit macs use Sage_FCompiler rather than Sage_FCompiler_1. Anyone who is familiar with the numpy spkg, please confirm or correct me!