Add lint writing documentation
[Rendered](https://github.com/phansch/rust-clippy/blob/adding_lints/doc/adding_lints.md)
This adds a new documentation page that explains how to write Clippy
lints. It guides the reader through creating a `foo` function lint.
I plan to iterate a bit more on the prose of some sections, but I think the
general structure is fine now, so I'm looking forward to feedback =)
One thing I'm not sure about: I felt like this is too big for CONTRIBUTING.md
so I put it into a new `doc/` directory. I can imagine having more
documentation in the future, so we might even want to create a book using
mdbook instead? Or should everything go into CONTRIBUTING.md?
Further things left to do:
- [x] Link from CONTRIBUTING.md
- [x] Remove things covered in this guide from CONTRIBUTING.md
- [x] Section about `clippy::author` attribute
- [x] Run `remark-lint` on CI over the `doc` directory and fix things
Start making clippy easier to invoke in non-cargo contexts
Clippy (clippy-driver) currently has a couple of strong but unnecessary couplings with cargo. This series:
1. makes detection of check builds more robust, and
2. make clippy-driver use the --sysroot specified on the command line as its internal sysroot.
This finishes up the rewrite of `update_lints.py` in Rust. More
specifically, this
* adds the `--check` flag and handling to clippy_dev
* tracks file changes over the different calls to `replace_region_in_file`
* only writes changes to files if the `--check` flag is *not* used
* runs `./util/dev update_lints --check` on CI instead of the old script
* replaces usage of the `update_lints.py` script with an error
`./util/dev update_lints` behaves 99% the same as the python script.
The only difference that I'm aware of is an ordering change to
`clippy_lints/src/lib.rs` because underscores seem to be sorted
differently in Rust and in Python.
🏁
3399: RIIR update lints: Generate modules section and lint group sections r=flip1995 a=phansch
This adds the last missing parts of the generating code.
cc #2882
Co-authored-by: Philipp Hansch <dev@phansch.net>
