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I want to integrate clangd with my IDE; where are the docs?

I am working on an IDE and I just discovered clangd. Sounds interesting. What do I need to do to integrate clangd with my IDE? Is there any documentation/examples/…?

Guessing from its name, I assume clangd is a daemon running in the background. How do I communicate with it?

Clangd is a language server. There’s a good overview at https://microsoft.github.io/language-server-protocol/overviews/lsp/overview/ and a detailed protocol spec that clangd implements much of.

You integrate with it by spawning it as a subprocess and speaking LSP via stdin/stdout. (There’s also a ClangdServer C++ API, but it has no stability guarantees, and no docs beyond what you’ll find in the code)


It’s also worth noting that, depending on your IDE’s implementation language, there may already be LSP client libraries that do a lot of the work for you. For example, for IDE’s written in Java there is LSP4J, and for IDE’s written in Javascript/Typescript there is vscode-languageserver-node.

Is there any information about specific extension of clangd ? Like the protocol specification for passing compiler arguments via the LSP instead of compile_commands.json ?

Extensions are here: http://clangd.llvm.org/extensions.html

Possible it’s not complete, though!

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