[Users] failed build on local mac osx yosemite [POSSIBLE SOLUTION TO THE PROBLEM]

[Erik Schnetter]

On Fri, May 22, 2015 at 12:38 PM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:

>
> On 22 May 2015, at 18:34, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>
>
> On 22 May 2015, at 16:10, Roberto De Pietri <roberto.depietri at unipr.it>
> wrote:
>
> Hi Ian:
>
>
> Thanks for the answer. I followed exactly your procedure and I was very
> surprised of having
> a failing compilation. Than I starting tracing back the problem.
> * All the thorns except one were compiling correctly.
> * The failing thorn was CarpetIOHDF5 and of the 5 source files present
> only 3 failed
> * The error was very strange because the only real problem was related to
>  a system include
> “/opt/local/lib/gcc49/gcc/x86_64-apple-darwin14/4.9.2/include/mmintrin.h”
>  and was related to conversion using AVX intel intrinsic. The error were
> of the type:
>
>  error: can’t convert between vector values of different size
>     return (__m64) __builtin_ia32_vec_init_v2si (__i, 0);
>
>
> There is a stackoverflow post (
> http://stackoverflow.com/questions/19043109/gcc-4-8-1-combining-c-code-with-c11-code
> ) which describes a similar problem, which I haven't studied in depth, but
> they seem to suggest that it's a bug in gcc, and that setting
> --std=gnu++11 instead of --std=c++11 in CXXFLAGS will work around the
> problem.
>
> Yes, it seems that this describes the problem we're having. GCC uses
__attribute__ to provide certain language extensions, e.g. for
vectorization. These are not optional declarations -- these modify function
definition and can't just be omitted.

And HDF5 does just that: it #defines __attribute__ to be empty (file
H5api_adpt.h, near the beginning) if the file is included from C++. I have
no idea why they would think this is legal, or why they would think this is
even a good idea. We use __attribute__ in Cactus (after checking via
autoconf whether it is supported) for a variety of optimizations and
security checks.

I would try adding the line

#undef __attribute__

right after (below) any line that says

#include <hdf5.h>

to undo (part of) the damage that HDF5 does. We should also complain to the
HDF5 authors.

-erik


>  We currently have
>
> CXXFLAGS = -g -std=c++14
>
> so I'm guessing that changing this to
>
> CXXFLAGS = -g -std=gnu++14
>
> might have the same effect.
>
> What I don't understand is why we didn't pick this up in testing.  I
> successfully compiled the whole ET using exactly that set of MacPorts
> packages and the optionlist before the release, and the gcc49 macports
> package hasn't been updated since 4 weeks ago.
>
>
> I should add that I tested it on 10.9.5, since I haven't been brave enough
> to update to 10.10 yet.  I think Erik was testing on 10.10, but he can
> confirm that.
>
> --
> Ian Hinder
> http://members.aei.mpg.de/ianhin
>
>
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>


-- 
Erik Schnetter <schnetter at cct.lsu.edu>
http://www.perimeterinstitute.ca/personal/eschnetter/
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