[Numpy-discussion] Solaris Sparc build broken

[David Cournapeau]

On Sat, Nov 7, 2009 at 2:10 AM, David Cournapeau <cournape at gmail.com> wrote:
> On Sat, Nov 7, 2009 at 12:05 AM, Charles R Harris
> <charlesr.harris at gmail.com> wrote:
>>
>>
>> On Fri, Nov 6, 2009 at 12:10 AM, David Cournapeau
>> <david at ar.media.kyoto-u.ac.jp> wrote:
>>>
>>> Charles R Harris wrote:
>>> >
>>> >
>>> > On Thu, Nov 5, 2009 at 10:35 PM, David Cournapeau
>>> > <david at ar.media.kyoto-u.ac.jp <mailto:david at ar.media.kyoto-u.ac.jp>>
>>> > wrote:
>>> >
>>> >     Charles R Harris wrote:
>>> >     > So you are going to leave us all hanging here in curiosity? What
>>> > is
>>> >     > your solution?
>>> >
>>> >     I had to sleep :)
>>> >
>>> >     The solution is based on parsing the generated binary code -
>>> >     that's how
>>> >     MPFR is doing it, so it has been tested in the wild. The code to
>>> >     compile
>>> >     is something like:
>>> >
>>> >     /* "before" is 16 bytes to ensure there's no padding between it
>>> >     and "x".
>>> >      *    We're not expecting any "long double" bigger than 16 bytes
>>> >     or with
>>> >      *       alignment requirements stricter than 16 bytes.  */
>>> >     typedef long double test_type;
>>> >
>>> >     struct {
>>> >            char         before[16];
>>> >            test_type    x;
>>> >            char         after[8];
>>> >     } foo = {
>>> >            { '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
>>> >              '\001', '\043', '\105', '\147', '\211', '\253', '\315',
>>> >     '\357' },
>>> >            -123456789.0,
>>> >            { '\376', '\334', '\272', '\230', '\166', '\124', '\062',
>>> >     '\020' }
>>> >     };
>>> >
>>> >     They compile it, parse with awk from the dump od -f.
>>> >
>>> >
>>> > So the before/after bits are tags that mark the beginning/end of the
>>> > type for the parse? Any particular reason not to use a string?
>>> As for why not using my name, I am not that megalomaniac, at least not
>>> yet :)
>>>
>>> od prints a dump in octal form, so a string is not much more readable. I
>>> am not sure why they use od instead of another dump format - but there
>>> is value if keeping the same format as them for testing, all other
>>> things being equal.
>>>
>>
>> Is od available on all platforms? Couldn't you just read the file using
>> Python?
>
> That's actually what I have done. I am pretty sure windows does not
> had od, for once :)

the implementation is here if you want to look at it:

http://svn.scipy.org/svn/numpy/trunk/numpy/core/setup_common.py

The code for pyod is ugly, there are wasteful back and forth
conversions, but it works, so..

David