CLANGD(1)

✨ NAME ✨

clangd — a language server that hands your editor IDE-level superpowers, bestie 💖 (this is the manual page for clangd 17, and yes, she's that girl)

🦋 DESCRIPTION 🦋

OVERVIEW: clangd is a language server that provides IDE-like features to editors. It's giving your text editor a full glow-up, no cap.

Okay so important vibe check first: it should be used via an editor plugin rather than invoked directly. Do NOT just run it in your terminal and expect magic — that's not the assignment, bestie 😭

For more information, see:

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

clangd accepts flags on the commandline, and in the CLANGD_FLAGS environment variable. Both. She's flexible like that 💅

USAGE:

clangd [options]

💫 OPTIONS 💫

🎀 Generic Options 🎀

• --help — Display available options (--help-hidden for more)
• --help-list — Display list of available options (--help-list-hidden for more)
• --version — Display the version of this program

🔥 clangd compilation flags options 🔥

• --compile-commands-dir=<string> — Specify a path to look for compile_commands.json. If path is invalid, clangd will look in the current directory and parent paths of each source file
• --query-driver=<string> — Comma separated list of globs for white-listing gcc-compatible drivers that are safe to execute. Drivers matching any of these globs will be used to extract system includes. e.g. /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 project code in the background and persist index on disk.
• --background-index-priority=<value> — Thread priority for building the background index. 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
• --fallback-style=<string> — clang-format style to apply by default when no .clang-format file is found
• --function-arg-placeholders — When disabled, completions contain only parentheses for function calls. When enabled, 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. Useful to investigate/reproduce crashes or configuration problems. With --check=<filename>, 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. 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 usages, 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

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And that's the whole page, bestie 🫶 go forth and let your editor slay. This was clangd 17, June 2025 — mwah 💋