CLANG-TIDY(1)

📦
version 19.1.7 · 5 versions
, in debian bookworm, debian trixie

💖 CLANG-TIDY 💖

okay bestie, gather round, because this is the manual page for clang-tidy version 19 and she is that girl. it's a User Commands situation, she lives in section 1, and she is about to change your whole entire C++ life. no cap.

✨ NAME ✨

clang-tidy — the manual page for clang-tidy 19 🎀

🌸 DESCRIPTION 🌸

so here's the vibe. how you call her:

USAGE: clang-tidy [options] <source0> [... <sourceN>]

and then, obviously, the OPTIONS. let's go 💅

💜 Generic Options 💜

these are the classics, the little basics every tool has, and honestly? iconic for it.

  • --help — shows you the available options (and if you want the secret menu, use --help-hidden for more). bestie, treat yourself.
  • --help-list — prints out the list of available options (--help-list-hidden for more, again, the hidden lore).
  • --version — tells you which version of this program you're running. it's giving "who am I" but make it a flag.

🦋 clang-tidy options 🦋

this is the main event. the whole feast. let's get into it.

  • --allow-no-checks — allows an empty enabled checks list. basically it suppresses the "no checks enabled" error that shows up when you disable, like, all of the checks. sometimes you just want a clean slate, and that's valid.
  • --checks=<string> — a comma-separated list of globs, and any glob can have an optional - prefix. globs get processed in the order they appear in the list. globs without the - prefix add checks with matching names to the set; globs with the - prefix remove checks with matching names from the set of enabled checks. and this option's value gets appended to the value of the Checks option in the .clang-tidy file, if there is one.
  • --config=<string> — specifies a configuration in YAML/JSON format. like so:
-config="{Checks: '*',
CheckOptions: {x: y}}"

when the value is empty, clang-tidy will attempt to find a file named .clang-tidy for each source file in its parent directories.

  • --config-file=<string> — specify the path of a .clang-tidy or a custom config file, e.g. --config-file=/some/path/myTidyConfigFile. internally this option works exactly the same way as the --config option after reading the specified config file.
and listen: use either --config-file or --config, not both. pick a lane bestie, she can't do both.
  • --dump-config — dumps the configuration in YAML format to stdout. this one can be used along with a file name (and -- if the file is outside of a project with a configured compilation database). the configuration used for this file will be printed. use it along with -checks=* to include the configuration of all the checks.
  • --enable-check-profile — enables per-check timing profiles and prints a report to stderr.
  • --enable-module-headers-parsing — enables preprocessor-level module header parsing for C++20 and above, which empowers specific checks to detect macro definitions within modules.
heads up though: this feature may cause performance and parsing issues and is therefore considered experimental. proceed with caution, queen.
  • --exclude-header-filter=<string> — a regular expression matching the names of the headers to exclude diagnostics from. diagnostics from the main file of each translation unit are always displayed, no matter what.
must be used together with --header-filter. can be used together with -line-filter. this option overrides the ExcludeHeaderFilterRegex option in .clang-tidy file, if any.
  • --explain-config — for each enabled check, explains where it is enabled, i.e. in the clang-tidy binary, on the command line, or in a specific configuration file. detective work, but make it fashion 🔍
  • --export-fixes=<filename> — a YAML file to store suggested fixes in. the stored fixes can be applied to the input source code with clang-apply-replacements.
  • --extra-arg=<string> — an additional argument to append to the compiler command line.
  • --extra-arg-before=<string> — an additional argument to prepend to the compiler command line.
  • --fix — applies suggested fixes. without -fix-errors, clang-tidy will bail out if any compilation errors were found.
  • --fix-errors — applies suggested fixes even if compilation errors were found. and if the compiler errors have attached fix-its, clang-tidy will apply those as well. bold. fearless. slay.
  • --fix-notes — if a warning has no fix, but a single fix can be found through an associated diagnostic note, apply the fix. specifying this flag will implicitly enable the --fix flag.
  • --format-style=<string> — the style for formatting code around applied fixes. the options:
    • 'none' (the default) turns off formatting.
    • 'file' — and yes, literally 'file', not a placeholder — uses the .clang-format file in the closest parent directory.
    • '{ <json> }' specifies options inline, e.g. -format-style='{BasedOnStyle: llvm, IndentWidth: 8}'
    • 'llvm', 'google', 'webkit', 'mozilla'

see the clang-format documentation for the up-to-date information about formatting styles and options. this option overrides the FormatStyle option in .clang-tidy file, if any.

  • --header-filter=<string> — a regular expression matching the names of the headers to output diagnostics from. diagnostics from the main file of each translation unit are always displayed. can be used together with -line-filter. this option overrides the HeaderFilterRegex option in .clang-tidy file, if any.
  • --line-filter=<string> — a list of files with line ranges to filter the warnings. can be used together with -header-filter. the format of the list is a JSON array of objects:
[      {"name":"file1.cpp","lines":[[1,3],[5,7]]}, {"name":"file2.h"}
]
  • --list-checks — lists all enabled checks and exits. use it with -checks=* to list all available checks. the full tour, if you will 💖
  • --load=<pluginfilename> — loads the specified plugin.
  • -p <string> — build path.
  • --quiet — runs clang-tidy in quiet mode. this suppresses printing statistics about ignored warnings and warnings treated as errors if the respective options are specified.
  • --store-check-profile=<prefix> — by default, reports are printed in tabulated format to stderr. when this option is passed, these per-TU profiles are instead stored as JSON.
  • --system-headers — displays the errors from system headers. this option overrides the SystemHeaders option in .clang-tidy file, if any.
  • --use-color — uses colors in diagnostics. if it's not set, colors will be used if the terminal connected to standard output supports colors. this option overrides the UseColor option in .clang-tidy file, if any. (we love a colorful queen 🌈)
  • --verify-config — checks the config files to make sure every single check and option is recognized.
  • --vfsoverlay=<filename> — overlays the virtual filesystem described by the file over the real file system.
  • --warnings-as-errors=<string> — upgrades warnings to errors. same format as -checks. this option's value is appended to the value of the WarningsAsErrors option in .clang-tidy file, if any.

okay now, the -p lore, because it matters:

-p <build-path> is used to read a compile command database.

for example, it can be a CMake build directory in which a file named compile_commands.json exists (use the -DCMAKE_EXPORT_COMPILE_COMMANDS=ON CMake option to get this output). when no build path is specified, a search for compile_commands.json will be attempted through all parent paths of the first input file. see: https://clang.llvm.org/docs/HowToSetupToolingForLLVM.html for an example of setting up Clang Tooling on a source tree.

<source0> ... — these specify the paths of source files. these paths are looked up in the compile command database.

  • if the path of a file is absolute, it needs to point into CMake's source tree.
  • if the path is relative, the current working directory needs to be in the CMake source tree, and the file must be in a subdirectory of the current working directory.
  • "./" prefixes in the relative files will be automatically removed, but the rest of a relative path must be a suffix of a path in the compile command database.

🎀 Configuration files 🎀

clang-tidy attempts to read configuration for each source file from a .clang-tidy file located in the closest parent directory of the source file. the .clang-tidy file is specified in YAML format. and if any configuration options have a corresponding command-line option, the command-line option takes precedence. (command line stays winning 💅)

the following configuration options may be used in a .clang-tidy file:

  • CheckOptions — a list of key-value pairs defining check-specific options. example:
CheckOptions:
  some-check.SomeOption: 'some value'
  • Checks — same as --checks. additionally, the list of globs can be specified as a list instead of a string.
  • ExcludeHeaderFilterRegex — same as --exclude-header-filter.
  • ExtraArgs — same as --extra-args.
  • ExtraArgsBefore — same as --extra-args-before.
  • FormatStyle — same as --format-style.
  • HeaderFileExtensions — file extensions to consider to determine if a given diagnostic is located in a header file.
  • HeaderFilterRegex — same as --header-filter-regex.
  • ImplementationFileExtensions — file extensions to consider to determine if a given diagnostic is located in an implementation file.
  • InheritParentConfig — if this option is true in a config file, the configuration file in the parent directory (if any exists) will be taken, and the current config file will be applied on top of the parent one.
  • SystemHeaders — same as --system-headers.
  • UseColor — same as --use-color.
  • User — specifies the name or e-mail of the user running clang-tidy. this option is used, for example, to place the correct user name in TODO() comments in the relevant check.
  • WarningsAsErrors — same as --warnings-as-errors.

and the effective configuration can be inspected using --dump-config:

$ clang-tidy --dump-config
---
Checks:              '-*,some-check'
WarningsAsErrors:    ''
HeaderFileExtensions:      ['', 'h','hh','hpp','hxx']
ImplementationFileExtensions: ['c','cc','cpp','cxx']
HeaderFilterRegex:            ''
FormatStyle:                  none
InheritParentConfig:          true
User:                         user
CheckOptions:
  some-check.SomeOption: 'some value'
...
💀 and that's literally the whole page. every flag, every config key, every weird little '' — nothing skipped, bestie, we keep it thorough around here.

anyway, mwah 💖 this was clang-tidy 19, June 2025, from the CLANG-TIDY(1) page. go forth and lint, you absolute icon 👑✨

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