CLANGD(1)

📦
version 20.1.8 · 4 versions
, in ubuntu stonking

💖 CLANGD 💖

okay bestie, welcome to the clangd manual page, straight from the User Commands corner of the universe ✨ this is the page for clangd 20, and no cap, it's a lot — but I got you, we're going through every single flag together 🫶

🌸 NAME 🌸

clangd — manual page for clangd 20 💅

✨ DESCRIPTION ✨

OVERVIEW: clangd is a language server that provides IDE-like features to editors 👑

Real talk: you should be using it via an editor plugin, not by yeeting it at your terminal directly. It's literally not built for that vibe. For more info, go look at:

https://clangd.llvm.org/
https://microsoft.github.io/language-server-protocol/

clangd accepts flags on the commandline, and in the CLANGD_FLAGS environment variable 🎀 (yes, the env var is real, it's giving main character energy)

USAGE: clangd [options]

OPTIONS:

🔧 GENERIC OPTIONS 🔧

  • --help — Show you the available options. And if that's not enough for you (valid), --help-hidden shows more 👀
  • --help-list — Show you a list of the available options. If you want more, --help-list-hidden has you covered ✨
  • --version — Print the version of this program. Simple. Iconic. Slay 💅

🧚 clangd compilation flags options 🧚

  • --compile-commands-dir=<string> — Point clangd at a path where it should go looking for compile_commands.json 📂 If that path is invalid, clangd will look in the current directory and in the parent paths of each source file instead — it's flexible like that.
  • --query-driver=<string> — A comma separated list of globs that white-lists gcc-compatible drivers that are safe to execute ⚠️ Drivers matching any of these globs will be used to extract system includes. For example: /usr/bin/**/clang-*,/path/to/repo/**/g++-*

👑 clangd feature options 👑

  • --all-scopes-completion — If set to true, code completion will include index symbols that are not defined in the scopes (e.g. namespaces) visible from the code completion point. Such completions can insert scope qualifiers 🔥
  • --background-index — Index your project code in the background and persist that index on disk. Obsessed with this one honestly 💾
  • --background-index-priority=<value> — Thread priority for building the background index. Heads up bestie: the effect of this flag is OS-specific 🙈
    • =background — Minimum priority, runs on idle CPUs. May leave 'performance' cores unused 😴
    • =low — Reduced priority compared to interactive work.
    • =normal — Same priority as other clangd work.
  • --clang-tidy — Enable clang-tidy diagnostics ✅
  • --completion-style=<value> — Granularity of code completion suggestions 🎀
    • =detailed — One completion item for each semantically distinct completion, with full type information 🔍
    • =bundled — Similar completion items (e.g. function overloads) are combined. Type information shown where possible 🎁
  • --experimental-modules-support — Experimental support for standard C++ modules 🧪 (experimental! be aware!)
  • --fallback-style=<string> — The clang-format style to apply by default when no .clang-format file is found 💄
  • --function-arg-placeholders=<string> — When disabled (0), completions contain only parentheses for function calls. When enabled (1), completions also contain placeholders for method parameters 🫶
  • --header-insertion=<value> — Add #include directives when accepting code completions 📥
    • =iwyu — Include what you use. Insert the owning header for top-level symbols, unless the header is already directly included or the symbol is forward-declared.
    • =never — Never insert #include directives as part of code completion 🚫
  • --header-insertion-decorators — Prepend a circular dot or space before the completion label, depending on whether an include line will be inserted or not ⭐
  • --import-insertions — If header insertion is enabled, add #import directives when accepting code completions or fixing includes in Objective-C code 🍎
  • --limit-references=<int> — Limit the number of references returned by clangd. 0 means no limit (default=1000) 🔢
  • --limit-results=<int> — Limit the number of results returned by clangd. 0 means no limit (default=100) 🔢
  • --project-root=<string> — Path to the project root. Requires remote-index-address to be set 🔗
  • --remote-index-address=<string> — Address of the remote index server 🌐
  • --rename-file-limit=<int> — Limit the number of files to be affected by symbol renaming. 0 means no limit (default=50) 🏷️

🌈 clangd miscellaneous options 🌈

  • --check[=<string>] — Parse one file in isolation instead of acting as a language server. Super useful to investigate/reproduce crashes or configuration problems 🕵️ With --check=<filename>, it attempts to parse a particular file.
  • --enable-config — Read user and project configuration from YAML files 📄 Project config is from a .clangd file in the project directory. User config is from clangd/config.yaml in the following directories:
    • Windows: %USERPROFILE%\AppData\Local
    • Mac OS: ~/Library/Preferences/
    • Others: $XDG_CONFIG_HOME, usually ~/.config

Configuration is documented at https://clangd.llvm.org/config.html 📚

  • -j <uint> — Number of async workers used by clangd. The background index also uses this many workers 🧑🤝🧑
  • --malloc-trim — Release memory periodically via malloc_trim(3) 🧹
  • --pch-storage=<value> — Storing PCHs in memory increases memory usage, but may improve performance ⚖️
    • =disk — store PCHs on disk 💽
    • =memory — store PCHs in memory 🧠

💜 clangd protocol and logging options 💜

  • --log=<value> — Verbosity of log messages written to stderr 📝
    • =error — Error messages only 🚨
    • =info — High level execution tracing 🔎
    • =verbose — Low level details 🗣️
  • --offset-encoding=<value> — Force the offsetEncoding used for character positions. This bypasses negotiation via client capabilities 🎯
    • =utf-8 — Offsets are in UTF-8 bytes
    • =utf-16 — Offsets are in UTF-16 code units
    • =utf-32 — Offsets are in unicode codepoints
  • --path-mappings=<string> — Translates between client paths (as seen by a remote editor) and server paths (where clangd sees files on disk) 🗺️ Comma separated list of '<client_path>=<server_path>' pairs, the first entry matching a given path is used. e.g. /home/project/incl=/opt/include,/home/project=/workarea/project
  • --pretty — Pretty-print JSON output 🌸 (your eyes will thank you)

and that's the whole page bestie, you ate that 🫶 this was clangd 20, dated September 2026, living in the User Commands family — go forth and be the main character of your own editor 💅✨🎀

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