Metal Shaders support

[yaroslavyaroslav]

Description

Currently when I'm opening metal and defining it as a c++ scope I got AST error from sourcekit-lsp. This way there's actually a lack of metal shaders development support out of Xcode in both completion and diagnostic. It would be great to bring such support to sourcekit-lsp even though metal is Apple's proprietary technology.

[ahoppen]

Synced to Apple’s issue tracker as rdar://132478984

[yaroslavyaroslav]

Haven't tried it with sourcekit-lsp directly, but this config works well with clangd.

Put .clangd in the root folder of the project with the following content:

If:
  PathMatch: .*\.metal?

CompileFlags:
  Add:
    - '--std'
    - 'c++17'
    - '-x'
    - 'c++'
    - '-I'
    - '/System/Library/Frameworks'
    - '-I'
    - '/Library/Frameworks'
    - '-I'
    - '/usr/local/include'
    - '-I'
    - '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/metal/32023/lib/clang/32023.335/include'
    - '-I'
    - '/System/Library/PrivateFrameworks/GPUCompiler.framework/Versions/32023/Libraries/lib/clang/32023.401/include/metal'

After clangd server restarted completion works well with in metal files in Sublime Text.

@ahoppen I wonder if it's worth it to mention this configuration somewhere in the sourcekit-lsp docs to ease other folks of cracking that down?

UPD: All the other missing headers can be found following the steps below:

1. mdfind -name [missing_header]
2. Add such in a separate line with -I flag to the config.

[ahoppen]

IIRC, Metal is a proper extension of C++ and has syntax constructs that won’t be supported by clangd. While your solution might cover many or most cases, I think the fact that it works is more a coincidence than proper support and thus I am very hesitant to offer it as any kind of officially supported solution in SourceKit-LSP’s docs.

[yaroslavyaroslav]

Yeah, fair enough. So looking forward to metal compiler will be supported by clangd as cuda did.