Use libcxxwrap-julia directly

[SylvainCorlay]

No description provided.

[SylvainCorlay]

Using the compiled libcxxwrap-julia in CxxWrap

[SylvainCorlay]

Hey @barche (happy holidays!) I am working on updating the julia bindings stack here, and just released xtensor-julia 0.10.0.

In this PR, I am trying to test with conda's build of libcxxwrap, by

• linking directly with it in the test of xtensor-julia
• specifying the proper entry in Overrides toml when installing CxxWrap.

I have two questions:

• why do I need CxxWrap.jl at all?
• there seems to be some issue on OSX when doing this. C++ exception while wrapping module StdLib: Symbol for type CppBasicString was not found. Do you have any hints about what is going on?

[SylvainCorlay]

Symbol for type CppBasicString was not found

It may be that the override is not properly handled on OS X, and two different libcxxwrap versions are used.

[SylvainCorlay]

Symbol for type CppBasicString was not found

It may be that the override is not properly handled on OS X, and two different libcxxwrap versions are used.

OK, using a symlink instead of an overrides yields the same result. So there is something about the way libcxxwrap is built on conda-forge for OSX that does not work for CxxWrap.jl.

[barche]

Hi Sylvain, happy holidays too :)

• CxxWrap.jl is needed because some of the type mapping code is in Julia. This is no problem when compiling a wrapper, but when you want to use libcxxwrap-julia at runtime you also need the Julia part installed.
• For the error my guess would be a version mismatch too, although the lates release of CxxWrap and libcxxwrap should match...

[SylvainCorlay]

Thanks for responding.

Tag 0.8.3 is pointing to 15d30a1d5952ebacc6bb16a297a236b8be63b763.
libcxxwrap_julia_jll.j is pointing to 37743e11cda7363a17840fe2353ff78a7e964a2c.

Could the mismatch be due to the "bigobj" flag that was added between the two?

[barche]

It's not clear to me which libcxxwrap-julia is found, in the config output nothing is placed, because JlCxx_INCLUDE_DIRS is no longer defined, the location can now be obtained using e.g. get_target_property(JlCxx_location JlCxx::cxxwrap_julia LOCATION).

Still, it's probably picking up the right one from conda. I do think the symlink command has the wrong order here:

ln -s $CXXWRAP_PREFIX $CONDA_PREFIX

Although using the Overrides.toml should be cleaner, where is that set up?

[SylvainCorlay]

Thank you for your reply. I eventually got things to pass with the symlink. Now I have to find the right incantations of Overrides.toml to not have to do this.

[SylvainCorlay]

Eventually I will try to make a conda package for CxxWrap.jl that depends on the conda package for libcxxwrap-julia. That will be a really good test case for the conda packaging of julia package. Really, the outstanding question is the one asked in JuliaInterop/CxxWrap.jl#309.