How to distribute a wrapper for a C++ library?

Tooling Package Management
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1

Could anyone share experience on how to distribute a C++ wrapper through package manager?

My workflow idea is the following:

  • package is available from a third-party registry
  • wrapped library and C++ shim are packaged in binary form and available from the same registry

Given that the shim depends on the wrapped library and the Julia module needs to load the shim first to work, what would be the recommended way to specify the paths to the corresponding artifacts?

2

I think you want to create a JLL package – GitHub - JuliaPackaging/Yggdrasil: Collection of builder repositories for BinaryBuilder.jl is probably the way to go.

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Yes, I think so too but so far I don’t have experience with that.
Say, I’ve managed to build a JLL for a binary library.
Now, how should I get the path to the .so file associated with it? Would it be exported in JLL or maybe it’s going to be a fixed path relative to JULIA_DEPOT_PATH?

4

It’s a good practice to follow hello world samples,

for C:

C++:

FORTRAN:

GO:

OCaml:

Rust:

3 Likes
5

Let’s have a look at a JLL package.

julia> using OpenSlide_jll

julia> names(OpenSlide_jll)
2-element Vector{Symbol}:
 :OpenSlide_jll
 :libopenslide

julia> OpenSlide_jll.libopenslide
"/home/gunnar/.julia/artifacts/e6604bff9ad493834da0c27adf8174616d54864e/lib/libopenslide.so"
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Thank you all for the directions!
Now I have to dig deeper into the BinaryBuilder and JLLs.

8

For example, QML.jl uses CxxWrap.jl to provide C-callable wrappers for an external C++ library (Qt). It seems to compile the wrapper and the C++ library into a single library: GitHub - JuliaGraphics/jlqml: C++ component of the QML.jl package, which packages a library in Julia as jlqml_jll using this Yggdrasil build script.

9

I was thinking too if it would be logical to package both wrapper and the original library into a single JLL. Thanks for pointing to a way how it may be done!

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10

I think my problem is related to the original question, but not exactly the same. I cannot figure out how I would be packaging (i.e. publishing on the registry) a CxxWrap based project that needs a Visual studio build of libcxxwrap-julia. When CxxWrap is installed on Windows, it pulls in a Mingw build of libcxxwrap-julia, which is not compatible with the glue that I need, since I am wrapping a Visual Studio built library (this is a given). What magic do I need in my project to make CxxWrap not load the Mingw version, or am I asking the wrong question.