CLANG-CHECK(1)

🎀 CLANG-CHECK 🎀

okay so bestie, this is the manual page for clang-check, and she lives in section 1 of the manual — user commands, main character energy only. 💅 pull up a chair, grab a boba, we're going through every single flag together, and yes we're going through all of them, no skipping. 🫶

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💖 NAME 💖

clang-check — the manual page for clang-check 12 ✨

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🦋 DESCRIPTION 🦋

here's the whole vibe in one line, literally the entire synopsis, iconic:

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

then it's just… options. a whole buffet of them. let's go 🍓

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🌈 OPTIONS 🌈

🌸 Generic Options 🌸

the everyday, everybody-gets-them options, no gatekeeping:

• --help — displays the available options. and if you want even more, there's --help-hidden 🙈
• --help-list — displays the list of available options. and yeah, --help-list-hidden exists for more 👀
• --version — displays the version of this program. flex it. 👑

💅 clang-check options 💅

okay this is the good part, the actual clang-check-specific stuff, she ate:

• --analyze — runs the static analysis engine 🔥
• --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 wanna know which declaration node names are even filterable, use -ast-list to list them all 🧚
• --ast-list — builds ASTs and prints the list of declaration node qualified names
• --ast-print — builds ASTs and then pretty-prints them (pretty!! as promised 💖)
• --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 (yes, before. order matters bestie 😭)
• --fix-what-you-can — applies fix-it advice even in the presence of unfixable errors. she does what she can, okay?? 💪
• --fixit — applies fix-it advice to the input source
• -p=<string> — build path 📁

okay so about that last one, because -p is a whole situation:

-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 — and to get that output you use the -DCMAKE_EXPORT_COMPILE_COMMANDS=ON CMake option. when no build path is specified, a search for compile_commands.json will be attempted through all parent paths of the first input file. and if you want a full example of setting up Clang Tooling on a source tree, it's right here: https://clang.llvm.org/docs/HowToSetupToolingForLLVM.html ✨

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🦋 about <source0> ... 🦋

<source0> ... specify the paths of source files. these paths are looked up in the compile command database. now here's the rules, and she is strict:

• 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. no cap, that's the rule. 🎯

for example, to run clang-check on all files in a subtree of the source tree, use:

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

or, using a specific build path:

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

note, that path/in/subtree and current directory should follow the rules described above. 👑 don't skip this part, it WILL humble you.

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and that's the whole page, bestie 🌈 we did it, we read every single line, nobody skipped the boring bits, we're so valid.

clang-check 12 — February 2022 — CLANG-CHECK(1) 🫶 bye ily, go compile something beautiful 💖✨