dolfin team mailing list archive

[Johan Hake <hake.dev@xxxxxxxxx>]

On 11/29/2012 02:42 PM, Joachim Berdal Haga wrote:
> Ok, no easy fix for this one then.

It does not look like it...

It is the runtime type info (RTTI) that is not well defined across
shared libraries, which we have with the SWIG interface.

>From a random web page:

There is no surprise here. Even for normal non-templated classes, you
should never expect the RTTI to work across shared-library boundaries.
For some compilers, on some OSes, with some compiler or linker options,
it might work, but in general, it will not, and is not required to
(explicitly left unspecified in the Standard). And even if you make it
work, it will be unsustainable in the long-run.


This does not sounds encouraging... I wonder if it is the compiler
version, which prevents it from working on the two buildbots.

Also there might be ways to get around using RTTI. For example:

 http://ciaranm.wordpress.com/2010/05/24/runtime-type-checking-in-c-without-rtti

If I did not miss something he assign an enumerate to each derived class
and use that to check for correct type. That sounds tedious, but maybe
not that bad considering we only need to check the Variable hierarchy?

Mvh

Johan

> I'm still inclined to suspect the swig type info, because it's the
> only thing I can think of that can plausibly explain the symptoms. The
> pointer (as seen in VTKPlotter) would be NULL, or perhaps
> reinterpret_cast-ed to something else. And it wouldn't be the first
> time swig was confused by templated types. Why it fails only on these
> machines is a mystery though.
> 
> -j.
> 
> On 29 November 2012 13:58, Johan Hake <hake.dev@xxxxxxxxx> wrote:
>> It has to do with a failing
>>
>> boost::dynamic_pointer_cast<const T >(var);
>>
>> where T is a shared_ptr type. See line 92 in VTKPlotter.cpp.
>>
>> This is the same problem we have with the uBLAS type converter we have
>> for a failing la unit test:
>>
>>   test/unit/la/python/test.py
>>
>> I challenge anyone with enough C++ foo to take this one head on!
>>
>> Johan
>>
>> On 11/29/2012 01:21 PM, Martin Sandve Alnæs wrote:
>>> Can someone who knows what the proper fix handle this? It would be nice
>>> to have a green buildbot again...
>>>
>>>
>>>
>>> ***
>>> -------------------------------------------------------------------------
>>> *** DOLFIN encountered an error. If you are not able to resolve this issue
>>> *** using the information listed below, you can ask for help at
>>> ***
>>> ***     https://answers.launchpad.net/dolfin
>>> ***
>>> *** Remember to include the error message listed below and, if possible,
>>> *** include a *minimal* running example to reproduce the error.
>>> ***
>>> ***
>>> -------------------------------------------------------------------------
>>> *** Error:   Unable to dolfin::plot.
>>> *** Reason:  Object type not supported for plotting.
>>> *** Where:   This error was encountered inside plot object.
>>> *** Process: 2
>>> ***
>>> -------------------------------------------------------------------------
>>>
>>>
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>>
>>
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