CLANG-CHECK(1)

🌸 clang-check — NAME 💅

okay so bestie, clang-check is literally the manual page for clang-check 18. that's it, that's the name, and we're already slaying ✨

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🦋 DESCRIPTION

the whole vibe, in one line:

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

and now, the options. buckle up, there's a lot, but we're getting through this together 🫶

✨ Generic Options ✨

• --help — shows you all the available options (and if you want even more chaos, there's --help-hidden for that)
• --help-list — prints out a list of the available options (again, --help-list-hidden exists if you're feeling extra)
• --version — tells you what version of this program you're on

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🎀 clang-check options 🎀

• --analyze — runs the static analysis engine. it's giving detective energy 🔍
• --analyzer-output-path=<string> — writes the output to <file>
• --ast-dump — builds ASTs and then debug dumps them
• --ast-dump-filter=<string> — use this with -ast-dump or -ast-print to dump/print only the AST declaration nodes that have a certain substring in a qualified name. and if you need the list of all the filterable declaration node names, use -ast-list. iykyk 💅
• --ast-list — builds ASTs and prints the list of declaration node qualified names
• --ast-print — builds ASTs and then pretty-prints them. pretty-print, pretty slay ✨
• --extra-arg=<string> — an extra argument to append to the compiler command line
• --extra-arg-before=<string> — an extra argument to prepend to the compiler command line (yes bestie, order matters, we love that for us)
• --fix-what-you-can — applies fix-it advice even when there are unfixable errors hanging around. iconic resilience honestly
• --fixit — applies fix-it advice to the input source
• -p <string> — build path
• --syntax-tree-dump — dumps the syntax tree
• --tokens-dump — dumps the preprocessed tokens

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🧚 the -p build path situation 🧚

-p <build-path> is what you use to read a compile command database. fr fr, that's its whole job.

for example, it can be a CMake build directory that has a file named compile_commands.json sitting in it (use the -DCMAKE_EXPORT_COMPILE_COMMANDS=ON CMake option to get that output). when you don't specify a build path, it'll try to search for compile_commands.json through all the parent paths of the first input file. 💫

want an example of setting up Clang Tooling on a source tree? here you go:

https://clang.llvm.org/docs/HowToSetupToolingForLLVM.html

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🍓 the source files 🍓

<source0> ... is where you specify the paths of your source files. these paths get 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.

also, ./ prefixes in relative files get automatically removed — but the rest of a relative path has to be a suffix of a path in the compile command database. no cap, that's the rule 📏

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🌈 examples, because we love a demonstration 🌈

say you wanna run clang-check on every file in a subtree of the source tree. do this:

find path/in/subtree -name '*.cpp'|xargs clang-check

or, if you wanna use a specific build path:

find path/in/subtree -name '*.cpp'|xargs clang-check -p build/path

heads up bestie — path/in/subtree and your current directory both need to follow the rules we just talked about up there. don't skip that part 🙈

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and that's the whole page!! go forth and check some clang, you absolute main character 👑

this has been clang-check 18, from June 2025, signing off 💜 ✨ 🦋