[libcxxwrap-julia] Update for Julia 1.7

[fingolfin]

No description provided.

[fingolfin]

CC @barche @thofma @benlorenz

[fingolfin]

Argh, of course this fails because Julia 1.7.0-beta2 has buggy C headers, to be fixed via JuliaLang/julia#41382 in beta3 (by backporting JuliaLang/julia#41308)

So to continue, we first need to add a patch for libjulia with at least that fix backported, then rebuild that again. sigh

[barche]

Could it be enough to apply the patch here, or does it affect the libjulia binary as well?

[fingolfin]

It would be enough but then every single Jll package using libjulia would need it. That makes no sense to me. Let's just merge #3264 (after I fixed it)

[fingolfin]

OK, seems we should have at least one more tweak in libjulia_jll (namely turn libuv back into a dependency, instead of just a builddep).

Anyway, I worked around that by adding libuv as a builddep here; next I run into compiler errors in the cxxwrap C++ codebase:

• jl_get_ptls_states still exist but is not declared in julia.h anymore. Instead, use jl_current_task->ptls
• jl_new_datatype gained a new argument, fattrs (one can simply pass jl_emptysvec for that)

I've added a patch to resolve both, also submitted as JuliaInterop/libcxxwrap-julia#86

Now it dies in the linker:

undefined reference to `jl_get_pgcstack'

[benlorenz]

Now it dies in the linker:

undefined reference to `jl_get_pgcstack'

So we probably need a patch for libjulia_jll (+ backport) of JuliaLang/julia#41320
At least with a local build of 1.7 this seems to help.

[fingolfin]

@benlorenz thanks for pointing that one out. It doesn't seem to be in JuliaLang/julia#41382 though -- I guess that'd we should ask for that, then. Will do

[fingolfin]

Note that even if we apply JuliaLang/julia#41320 the resulting binaries won't work there.

[barche]

Same error when building libcxxwrap locally against the julia1.7 beta2 binariy.

[fingolfin]

Yeah, beta2 is just broken in several ways for anybody trying to link against its C ABI. We gotta hope beta3 will be better

[giordano]

% nm libjulia.v1.7.0.x86_64-linux-gnu-cxx11-julia_version+1.7.0/lib/libjulia.so | grep jl_get_pgcstack
% nm libjulia.v1.7.0.x86_64-linux-gnu-cxx11-julia_version+1.7.0/lib/libjulia-internal.so | grep jl_get_pgcstack
0000000000107fb0 T jl_get_pgcstack
0000000000498a48 d jl_get_pgcstack_cb
0000000000107e20 t jl_get_pgcstack_fallback
0000000000107e60 t jl_get_pgcstack_init

[fingolfin]

Yeah the symbol exists, it just is not exported; on master this was fixed in JuliaLang/julia#41320 but that one is not even scheduled for backporting yet :-(

[giordano]

but that one is not even scheduled for backporting yet :-(

[fingolfin]

Ah, great! Thanks @vchuravy

[giordano]

Issue JuliaLang/julia#41464 is probably going to track something relevant for you as well

[fingolfin]

With the new patched libjulia_jll this now builds. I also dropped the patches and instead switched to a newer commit of the libcxxwrap-julia git repository which already has those patches applied.

Seems to build now! yay

[fingolfin]

@giordano OK to merge?