CLANG-TIDY(1)

📦
version 13.0.1 · 3 versions
, in ubuntu jammy

🎀 NAME 🎀

clang-tidy — bestie, this is the manual page for clang-tidy 13, and honestly it's a lot, but we're gonna get through it together 💖 (it lives in section 1 of the manual, iykyk)

✨ DESCRIPTION ✨

okay so the whole vibe is you run it like this:

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

and then there are OPTIONS. so many options. let's go 🫶

🌈 Generic Options

  • --help — shows you all the available options (and if you want even more, there's --help-hidden 👀)
  • --help-list — shows you the whole list of available options (again, --help-list-hidden for the extra ones)
  • --version — tells you which version of this program you're running, slay

💅 clang-tidy options

  • --checks=<string> — a comma-separated list of globs, each one optionally prefixed with a -. The globs get processed in the order they show up in the list. Globs with no - prefix add checks whose names match into the set; globs with a - prefix remove checks with matching names from the set of enabled checks. And listen — this option's value gets appended onto the value of the 'Checks' option in the .clang-tidy file, if there is one.
  • --config=<string> — specifies a configuration in YAML/JSON format:
-config="{Checks: '*',
CheckOptions: [{key: x,
value: 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 .clang-tidy or a custom config file, like:
e.g. --config-file=/some/path/myTidyConfigFile

This option internally works exactly the same way as --config after reading the specified config file. Use either --config-file or --config, not both — pick a lane bestie 🙈

  • --dump-config — dumps the configuration in YAML format to stdout. This option can be used along with a file name (and '--' if the file is outside of a project with configured compilation database). The configuration used for this file will be printed. Use it along with -checks=* to include configuration of all checks. 👑
  • --enable-check-profile — enables per-check timing profiles, and prints a report to stderr. ✨
  • --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. the receipts, literally 🧾
  • --export-fixes=<filename> — 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 — apply suggested fixes. Without -fix-errors, clang-tidy will bail out if any compilation errors were found.
  • --fix-errors — apply suggested fixes even if compilation errors were found. If compiler errors have attached fix-its, clang-tidy will apply them as well.
  • --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> — style for formatting code around applied fixes:
    • 'none' (default) turns off formatting
    • 'file' (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> — 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> — 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 — list all enabled checks and exit. Use with -checks=* to list all available checks. 🌸
  • -p=<string> — build path
  • --quiet — run 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 — display the errors from system headers. no more hiding 💀
  • --use-color — use colors in diagnostics. If 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. 🌈
  • --vfsoverlay=<filename> — overlay the virtual filesystem described by 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 important context, because this part actually 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> ... specifies 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. If InheritParentConfig 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. If any configuration options have a corresponding command-line option, the command-line option takes precedence. The effective configuration can be inspected using -dump-config:

$ clang-tidy -dump-config

and here's what that looks like, bestie:

---

Checks: '-*,some-check'

WarningsAsErrors: ''

HeaderFilterRegex: ''

FormatStyle: none

InheritParentConfig: true
User: user
CheckOptions:
  - key: some-check.SomeOption
    value: 'some value'

...
⚠️ quick heads up: --config-file and --config are mutually exclusive — use one, not both. and command-line options always win over config file options, no cap.

that's the whole page!! go forth and tidy ur C++ 💜 this was clang-tidy version 13, dated July 2023 — she's a little vintage but she ate 👑💅

📦 where this page comes from