Add Darwin support for ccls

[Kaali]

Motivation for this change

Darwin was not in supported branches.

Things done

Had to set a few compile flags to make it work. And set stdenv from llvmPackages_latest, as Darwin Clang is too old to compile and run CCLS. Visibility change fixes a lot of warnings regarding different visibility in different translation units re. llvmlib

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

[Mic92]

Thanks!

[bwolf]

I wonder how to use this. I cannot build it in my clone of Nixpkgs. I'm on 10.14.3 with Nix 2.2.1.

[ 86%] Building CXX object tools/extra/clangd/xpc/CMakeFiles/clangdXpcJsonConversions.dir/Conversion.cpp.o
In file included from /private/var/folders/pw/0qj665hx4w19p13bh8y630xm0000gp/T/nix-build-clang-8.0.0rc2.drv-0/clang/tools/extra/clangd/xpc/Conversion.cpp:10:
/private/var/folders/pw/0qj665hx4w19p13bh8y630xm0000gp/T/nix-build-clang-8.0.0rc2.drv-0/clang/tools/extra/clangd/xpc/../xpc/Conversion.h:14:10: fatal error: 'xpc/xpc.h' file not found
#include <xpc/xpc.h>
         ^~~~~~~~~~~
1 error generated.
make[2]: *** [tools/extra/clangd/xpc/CMakeFiles/clangdXpcJsonConversions.dir/build.make:63: tools/extra/clangd/xpc/CMakeFiles/clangdXpcJsonConversions.dir/Conversion.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:8424: tools/extra/clangd/xpc/CMakeFiles/clangdXpcJsonConversions.dir/all] Error 2

And later:

make: *** [Makefile:130: all] Error 2
builder for '/nix/store/n8gjmwfpl3cbiyb0v6ki09nnj2qzg67p-clang-8.0.0rc2.drv' failed with exit code 2
cannot build derivation '/nix/store/7hknhfb23ndwb444vc6mzcf2wvr20crh-ccls-0.20190301.drv': 1 dependencies couldn't be built
error: build of '/nix/store/7hknhfb23ndwb444vc6mzcf2wvr20crh-ccls-0.20190301.drv' failed

I issued the following commands to build:

export NIXPKGS=~/Code/Play/nixpkgs
nix-build $NIXPKGS -A ccls

[Kaali]

I tried the newest master of nixpkgs and it also fails for me. Even though with this PR it still worked. I haven't bisected yet why it doesn't work anymore.

[Kaali]

I tried building the commit that worked for me, which also doesn't work anymore. Even though I have a working version cached on my computer. Could it be a macOS system update related problem?

[Kaali]

It seems like PR #56645 changed something with llvmPackages. On macOS llvmPackages_latest doesn't provide the latest LLVM anymore. Version 5 is used instead, and ccls requires a newer version.

I could either set it to some specific version, or does somebody know why _latest returns version 5 here?

[bwolf]

It seems like PR #56645 changed something with llvmPackages. On macOS llvmPackages_latest doesn't provide the latest LLVM anymore. Version 5 is used instead, and ccls requires a newer version.

This is exactly the behaviour which I observed. For me this also applies to packages like cmake, which is annoying when you require a newer toolchain.