38 lines
2 KiB
Markdown
38 lines
2 KiB
Markdown
|
# Using clang-tidy on C++ Code
|
||
|
|
|
||
|
|
[`clang-tidy`](https://clang.llvm.org/extra/clang-tidy/) is a tool to
|
||
|
|
automatically check C/C++/Objective-C code for style violations, programming
|
||
|
|
errors, and best practices.
|
||
|
|
|
||
|
|
Electron's `clang-tidy` integration is provided as a linter script which can
|
||
|
|
be run with `npm run lint:clang-tidy`. While `clang-tidy` checks your on-disk
|
||
|
|
files, you need to have built Electron so that it knows which compiler flags
|
||
|
|
were used. There is one required option for the script `--output-dir`, which
|
||
|
|
tells the script which build directory to pull the compilation information
|
||
|
|
from. A typical usage would be:
|
||
|
|
`npm run lint:clang-tiy --out-dir ../out/Testing`
|
||
|
|
|
||
|
|
With no filenames provided, all C/C++/Objective-C files will be checked.
|
||
|
|
You can provide a list of files to be checked by passing the filenames after
|
||
|
|
the options:
|
||
|
|
`npm run lint:clang-tiy --out-dir ../out/Testing shell/browser/api/electron_api_app.cc`
|
||
|
|
|
||
|
|
While `clang-tidy` has a
|
||
|
|
[long list](https://clang.llvm.org/extra/clang-tidy/checks/list.html)
|
||
|
|
of possible checks, in Electron only a few are enabled by default. At the
|
||
|
|
moment Electron doesn't have a `.clang-tidy` config, so `clang-tidy` will
|
||
|
|
find the one from Chromium at `src/.clang-tidy` and use the checks which
|
||
|
|
Chromium has enabled. You can change which checks are run by using the
|
||
|
|
`--checks=` option. This is passed straight through to `clang-tidy`, so see
|
||
|
|
its documentation for full details. Wildcards can be used, and checks can
|
||
|
|
be disabled by prefixing a `-`. By default any checks listed are added to
|
||
|
|
those in `.clang-tidy`, so if you'd like to limit the checks to specific
|
||
|
|
ones you should first exclude all checks then add back what you want, like
|
||
|
|
`--checks=-*,performance*`.
|
||
|
|
|
||
|
|
Running `clang-tidy` is rather slow - internally it compiles each file and
|
||
|
|
then runs the checks so it will always be some factor slower than compilation.
|
||
|
|
While you can use parallel runs to speed it up using the `--jobs|-j` option,
|
||
|
|
`clang-tidy` also uses a lot of memory during its checks, so it can easily
|
||
|
|
run into out-of-memory errors. As such the default number of jobs is one.
|