--- /dev/null
+# Adding a new lint
+
+You are probably here because you want to add a new lint to Clippy. If this is
+the first time you're contributing to Clippy, this document guides you through
+creating an example lint from scratch.
+
+To get started, we will create a lint that detects functions called `foo`,
+because that's clearly a non-descriptive name.
+
+- [Adding a new lint](#adding-a-new-lint)
+ - [Setup](#setup)
+ - [Getting Started](#getting-started)
+ - [Testing](#testing)
+ - [Rustfix tests](#rustfix-tests)
+ - [Edition 2018 tests](#edition-2018-tests)
+ - [Testing manually](#testing-manually)
+ - [Lint declaration](#lint-declaration)
+ - [Lint passes](#lint-passes)
+ - [Emitting a lint](#emitting-a-lint)
+ - [Adding the lint logic](#adding-the-lint-logic)
+ - [Specifying the lint's minimum supported Rust version (msrv)](#specifying-the-lints-minimum-supported-rust-version-msrv)
+ - [Author lint](#author-lint)
+ - [Documentation](#documentation)
+ - [Running rustfmt](#running-rustfmt)
+ - [Debugging](#debugging)
+ - [PR Checklist](#pr-checklist)
+ - [Adding configuration to a lint](#adding-configuration-to-a-lint)
+ - [Cheatsheet](#cheatsheet)
+
+## Setup
+
+See the [Basics](basics.md#get-the-code) documentation.
+
+## Getting Started
+
+There is a bit of boilerplate code that needs to be set up when creating a new
+lint. Fortunately, you can use the clippy dev tools to handle this for you. We
+are naming our new lint `foo_functions` (lints are generally written in snake
+case), and we don't need type information so it will have an early pass type
+(more on this later on). If you're not sure if the name you chose fits the lint,
+take a look at our [lint naming guidelines][lint_naming]. To get started on this
+lint you can run `cargo dev new_lint --name=foo_functions --pass=early
+--category=pedantic` (category will default to nursery if not provided). This
+command will create two files: `tests/ui/foo_functions.rs` and
+`clippy_lints/src/foo_functions.rs`, as well as run `cargo dev update_lints` to
+register the new lint. For cargo lints, two project hierarchies (fail/pass) will
+be created by default under `tests/ui-cargo`.
+
+Next, we'll open up these files and add our lint!
+
+## Testing
+
+Let's write some tests first that we can execute while we iterate on our lint.
+
+Clippy uses UI tests for testing. UI tests check that the output of Clippy is
+exactly as expected. Each test is just a plain Rust file that contains the code
+we want to check. The output of Clippy is compared against a `.stderr` file.
+Note that you don't have to create this file yourself, we'll get to
+generating the `.stderr` files further down.
+
+We start by opening the test file created at `tests/ui/foo_functions.rs`.
+
+Update the file with some examples to get started:
+
+```rust
+#![warn(clippy::foo_functions)]
+
+// Impl methods
+struct A;
+impl A {
+ pub fn fo(&self) {}
+ pub fn foo(&self) {}
+ pub fn food(&self) {}
+}
+
+// Default trait methods
+trait B {
+ fn fo(&self) {}
+ fn foo(&self) {}
+ fn food(&self) {}
+}
+
+// Plain functions
+fn fo() {}
+fn foo() {}
+fn food() {}
+
+fn main() {
+ // We also don't want to lint method calls
+ foo();
+ let a = A;
+ a.foo();
+}
+```
+
+Now we can run the test with `TESTNAME=foo_functions cargo uitest`,
+currently this test is meaningless though.
+
+While we are working on implementing our lint, we can keep running the UI
+test. That allows us to check if the output is turning into what we want.
+
+Once we are satisfied with the output, we need to run
+`cargo dev bless` to update the `.stderr` file for our lint.
+Please note that, we should run `TESTNAME=foo_functions cargo uitest`
+every time before running `cargo dev bless`.
+Running `TESTNAME=foo_functions cargo uitest` should pass then. When we commit
+our lint, we need to commit the generated `.stderr` files, too. In general, you
+should only commit files changed by `cargo dev bless` for the
+specific lint you are creating/editing. Note that if the generated files are
+empty, they should be removed.
+
+Note that you can run multiple test files by specifying a comma separated list:
+`TESTNAME=foo_functions,test2,test3`.
+
+### Cargo lints
+
+For cargo lints, the process of testing differs in that we are interested in
+the `Cargo.toml` manifest file. We also need a minimal crate associated
+with that manifest.
+
+If our new lint is named e.g. `foo_categories`, after running `cargo dev new_lint`
+we will find by default two new crates, each with its manifest file:
+
+* `tests/ui-cargo/foo_categories/fail/Cargo.toml`: this file should cause the new lint to raise an error.
+* `tests/ui-cargo/foo_categories/pass/Cargo.toml`: this file should not trigger the lint.
+
+If you need more cases, you can copy one of those crates (under `foo_categories`) and rename it.
+
+The process of generating the `.stderr` file is the same, and prepending the `TESTNAME`
+variable to `cargo uitest` works too.
+
+## Rustfix tests
+
+If the lint you are working on is making use of structured suggestions, the
+test file should include a `// run-rustfix` comment at the top. This will
+additionally run [rustfix] for that test. Rustfix will apply the suggestions
+from the lint to the code of the test file and compare that to the contents of
+a `.fixed` file.
+
+Use `cargo dev bless` to automatically generate the
+`.fixed` file after running the tests.
+
+[rustfix]: https://github.com/rust-lang/rustfix
+
+## Edition 2018 tests
+
+Some features require the 2018 edition to work (e.g. `async_await`), but
+compile-test tests run on the 2015 edition by default. To change this behavior
+add `// edition:2018` at the top of the test file (note that it's space-sensitive).
+
+## Testing manually
+
+Manually testing against an example file can be useful if you have added some
+`println!`s and the test suite output becomes unreadable. To try Clippy with
+your local modifications, run
+
+```
+env __CLIPPY_INTERNAL_TESTS=true cargo run --bin clippy-driver -- -L ./target/debug input.rs
+```
+
+from the working copy root. With tests in place, let's have a look at
+implementing our lint now.
+
+## Lint declaration
+
+Let's start by opening the new file created in the `clippy_lints` crate
+at `clippy_lints/src/foo_functions.rs`. That's the crate where all the
+lint code is. This file has already imported some initial things we will need:
+
+```rust
+use rustc_lint::{EarlyLintPass, EarlyContext};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_ast::ast::*;
+```
+
+The next step is to update the lint declaration. Lints are declared using the
+[`declare_clippy_lint!`][declare_clippy_lint] macro, and we just need to update
+the auto-generated lint declaration to have a real description, something like this:
+
+```rust
+declare_clippy_lint! {
+ /// **What it does:**
+ ///
+ /// **Why is this bad?**
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// // example code
+ /// ```
+ pub FOO_FUNCTIONS,
+ pedantic,
+ "function named `foo`, which is not a descriptive name"
+}
+```
+
+* The section of lines prefixed with `///` constitutes the lint documentation
+ section. This is the default documentation style and will be displayed
+ [like this][example_lint_page]. To render and open this documentation locally
+ in a browser, run `cargo dev serve`.
+* `FOO_FUNCTIONS` is the name of our lint. Be sure to follow the
+ [lint naming guidelines][lint_naming] here when naming your lint.
+ In short, the name should state the thing that is being checked for and
+ read well when used with `allow`/`warn`/`deny`.
+* `pedantic` sets the lint level to `Allow`.
+ The exact mapping can be found [here][category_level_mapping]
+* The last part should be a text that explains what exactly is wrong with the
+ code
+
+The rest of this file contains an empty implementation for our lint pass,
+which in this case is `EarlyLintPass` and should look like this:
+
+```rust
+// clippy_lints/src/foo_functions.rs
+
+// .. imports and lint declaration ..
+
+declare_lint_pass!(FooFunctions => [FOO_FUNCTIONS]);
+
+impl EarlyLintPass for FooFunctions {}
+```
+
+Normally after declaring the lint, we have to run `cargo dev update_lints`,
+which updates some files, so Clippy knows about the new lint. Since we used
+`cargo dev new_lint ...` to generate the lint declaration, this was done
+automatically. While `update_lints` automates most of the things, it doesn't
+automate everything. We will have to register our lint pass manually in the
+`register_plugins` function in `clippy_lints/src/lib.rs`:
+
+```rust
+store.register_early_pass(|| box foo_functions::FooFunctions);
+```
+
+As one may expect, there is a corresponding `register_late_pass` method
+available as well. Without a call to one of `register_early_pass` or
+`register_late_pass`, the lint pass in question will not be run.
+
+One reason that `cargo dev` does not automate this step is that multiple lints
+can use the same lint pass, so registering the lint pass may already be done
+when adding a new lint. Another reason that this step is not automated is that
+the order that the passes are registered determines the order the passes
+actually run, which in turn affects the order that any emitted lints are output
+in.
+
+[declare_clippy_lint]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/lib.rs#L60
+[example_lint_page]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure
+[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
+[category_level_mapping]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/lib.rs#L110
+
+## Lint passes
+
+Writing a lint that only checks for the name of a function means that we only
+have to deal with the AST and don't have to deal with the type system at all.
+This is good, because it makes writing this particular lint less complicated.
+
+We have to make this decision with every new Clippy lint. It boils down to using
+either [`EarlyLintPass`][early_lint_pass] or [`LateLintPass`][late_lint_pass].
+
+In short, the `LateLintPass` has access to type information while the
+`EarlyLintPass` doesn't. If you don't need access to type information, use the
+`EarlyLintPass`. The `EarlyLintPass` is also faster. However linting speed
+hasn't really been a concern with Clippy so far.
+
+Since we don't need type information for checking the function name, we used
+`--pass=early` when running the new lint automation and all the imports were
+added accordingly.
+
+[early_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.EarlyLintPass.html
+[late_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.LateLintPass.html
+
+## Emitting a lint
+
+With UI tests and the lint declaration in place, we can start working on the
+implementation of the lint logic.
+
+Let's start by implementing the `EarlyLintPass` for our `FooFunctions`:
+
+```rust
+impl EarlyLintPass for FooFunctions {
+ fn check_fn(&mut self, cx: &EarlyContext<'_>, fn_kind: FnKind<'_>, span: Span, _: NodeId) {
+ // TODO: Emit lint here
+ }
+}
+```
+
+We implement the [`check_fn`][check_fn] method from the
+[`EarlyLintPass`][early_lint_pass] trait. This gives us access to various
+information about the function that is currently being checked. More on that in
+the next section. Let's worry about the details later and emit our lint for
+*every* function definition first.
+
+Depending on how complex we want our lint message to be, we can choose from a
+variety of lint emission functions. They can all be found in
+[`clippy_utils/src/diagnostics.rs`][diagnostics].
+
+`span_lint_and_help` seems most appropriate in this case. It allows us to
+provide an extra help message and we can't really suggest a better name
+automatically. This is how it looks:
+
+```rust
+impl EarlyLintPass for FooFunctions {
+ fn check_fn(&mut self, cx: &EarlyContext<'_>, fn_kind: FnKind<'_>, span: Span, _: NodeId) {
+ span_lint_and_help(
+ cx,
+ FOO_FUNCTIONS,
+ span,
+ "function named `foo`",
+ None,
+ "consider using a more meaningful name"
+ );
+ }
+}
+```
+
+Running our UI test should now produce output that contains the lint message.
+
+According to [the rustc-dev-guide], the text should be matter of fact and avoid
+capitalization and periods, unless multiple sentences are needed.
+When code or an identifier must appear in a message or label, it should be
+surrounded with single grave accents \`.
+
+[check_fn]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.EarlyLintPass.html#method.check_fn
+[diagnostics]: https://github.com/rust-lang/rust-clippy/blob/master/clippy_utils/src/diagnostics.rs
+[the rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org/diagnostics.html
+
+## Adding the lint logic
+
+Writing the logic for your lint will most likely be different from our example,
+so this section is kept rather short.
+
+Using the [`check_fn`][check_fn] method gives us access to [`FnKind`][fn_kind]
+that has the [`FnKind::Fn`] variant. It provides access to the name of the
+function/method via an [`Ident`][ident].
+
+With that we can expand our `check_fn` method to:
+
+```rust
+impl EarlyLintPass for FooFunctions {
+ fn check_fn(&mut self, cx: &EarlyContext<'_>, fn_kind: FnKind<'_>, span: Span, _: NodeId) {
+ if is_foo_fn(fn_kind) {
+ span_lint_and_help(
+ cx,
+ FOO_FUNCTIONS,
+ span,
+ "function named `foo`",
+ None,
+ "consider using a more meaningful name"
+ );
+ }
+ }
+}
+```
+
+We separate the lint conditional from the lint emissions because it makes the
+code a bit easier to read. In some cases this separation would also allow to
+write some unit tests (as opposed to only UI tests) for the separate function.
+
+In our example, `is_foo_fn` looks like:
+
+```rust
+// use statements, impl EarlyLintPass, check_fn, ..
+
+fn is_foo_fn(fn_kind: FnKind<'_>) -> bool {
+ match fn_kind {
+ FnKind::Fn(_, ident, ..) => {
+ // check if `fn` name is `foo`
+ ident.name.as_str() == "foo"
+ }
+ // ignore closures
+ FnKind::Closure(..) => false
+ }
+}
+```
+
+Now we should also run the full test suite with `cargo test`. At this point
+running `cargo test` should produce the expected output. Remember to run
+`cargo dev bless` to update the `.stderr` file.
+
+`cargo test` (as opposed to `cargo uitest`) will also ensure that our lint
+implementation is not violating any Clippy lints itself.
+
+That should be it for the lint implementation. Running `cargo test` should now
+pass.
+
+[fn_kind]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/visit/enum.FnKind.html
+[`FnKind::Fn`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/visit/enum.FnKind.html#variant.Fn
+[ident]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/symbol/struct.Ident.html
+
+## Specifying the lint's minimum supported Rust version (msrv)
+
+Projects supporting older versions of Rust would need to disable a lint if it targets features
+present in later versions. Support for this can be added by specifying an msrv in your lint like so,
+
+```rust
+const MANUAL_STRIP_MSRV: RustcVersion = RustcVersion::new(1, 45, 0);
+```
+
+The project's msrv will also have to be an attribute in the lint so you'll have to add a struct
+and constructor for your lint. The project's msrv needs to be passed when the lint is registered
+in `lib.rs`
+
+```rust
+pub struct ManualStrip {
+ msrv: Option<RustcVersion>,
+}
+
+impl ManualStrip {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+```
+
+The project's msrv can then be matched against the lint's msrv in the LintPass using the `meets_msrv` utility
+function.
+
+``` rust
+if !meets_msrv(self.msrv.as_ref(), &MANUAL_STRIP_MSRV) {
+ return;
+}
+```
+
+The project's msrv can also be specified as an inner attribute, which overrides the value from
+`clippy.toml`. This can be accounted for using the `extract_msrv_attr!(LintContext)` macro and passing
+LateContext/EarlyContext.
+
+```rust
+impl<'tcx> LateLintPass<'tcx> for ManualStrip {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ ...
+ }
+ extract_msrv_attr!(LateContext);
+}
+```
+
+Once the msrv is added to the lint, a relevant test case should be added to `tests/ui/min_rust_version_attr.rs`
+which verifies that the lint isn't emitted if the project's msrv is lower.
+
+## Author lint
+
+If you have trouble implementing your lint, there is also the internal `author`
+lint to generate Clippy code that detects the offending pattern. It does not
+work for all of the Rust syntax, but can give a good starting point.
+
+The quickest way to use it, is the
+[Rust playground: play.rust-lang.org][author_example].
+Put the code you want to lint into the editor and add the `#[clippy::author]`
+attribute above the item. Then run Clippy via `Tools -> Clippy` and you should
+see the generated code in the output below.
+
+[Here][author_example] is an example on the playground.
+
+If the command was executed successfully, you can copy the code over to where
+you are implementing your lint.
+
+[author_example]: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=9a12cb60e5c6ad4e3003ac6d5e63cf55
+
+## Documentation
+
+The final thing before submitting our PR is to add some documentation to our
+lint declaration.
+
+Please document your lint with a doc comment akin to the following:
+
+```rust
+declare_clippy_lint! {
+ /// **What it does:** Checks for ... (describe what the lint matches).
+ ///
+ /// **Why is this bad?** Supply the reason for linting the code.
+ ///
+ /// **Known problems:** None. (Or describe where it could go wrong.)
+ ///
+ /// **Example:**
+ ///
+ /// ```rust,ignore
+ /// // Bad
+ /// Insert a short example of code that triggers the lint
+ ///
+ /// // Good
+ /// Insert a short example of improved code that doesn't trigger the lint
+ /// ```
+ pub FOO_FUNCTIONS,
+ pedantic,
+ "function named `foo`, which is not a descriptive name"
+}
+```
+
+Once your lint is merged, this documentation will show up in the [lint
+list][lint_list].
+
+[lint_list]: https://rust-lang.github.io/rust-clippy/master/index.html
+
+## Running rustfmt
+
+[Rustfmt] is a tool for formatting Rust code according to style guidelines.
+Your code has to be formatted by `rustfmt` before a PR can be merged.
+Clippy uses nightly `rustfmt` in the CI.
+
+It can be installed via `rustup`:
+
+```bash
+rustup component add rustfmt --toolchain=nightly
+```
+
+Use `cargo dev fmt` to format the whole codebase. Make sure that `rustfmt` is
+installed for the nightly toolchain.
+
+[Rustfmt]: https://github.com/rust-lang/rustfmt
+
+## Debugging
+
+If you want to debug parts of your lint implementation, you can use the [`dbg!`]
+macro anywhere in your code. Running the tests should then include the debug
+output in the `stdout` part.
+
+[`dbg!`]: https://doc.rust-lang.org/std/macro.dbg.html
+
+## PR Checklist
+
+Before submitting your PR make sure you followed all of the basic requirements:
+
+<!-- Sync this with `.github/PULL_REQUEST_TEMPLATE` -->
+
+- \[ ] Followed [lint naming conventions][lint_naming]
+- \[ ] Added passing UI tests (including committed `.stderr` file)
+- \[ ] `cargo test` passes locally
+- \[ ] Executed `cargo dev update_lints`
+- \[ ] Added lint documentation
+- \[ ] Run `cargo dev fmt`
+
+## Adding configuration to a lint
+
+Clippy supports the configuration of lints values using a `clippy.toml` file in the workspace
+directory. Adding a configuration to a lint can be useful for thresholds or to constrain some
+behavior that can be seen as a false positive for some users. Adding a configuration is done
+in the following steps:
+
+1. Adding a new configuration entry to [clippy_utils::conf](/clippy_utils/src/conf.rs)
+ like this:
+ ```rust
+ /// Lint: LINT_NAME. <The configuration field doc comment>
+ (configuration_ident, "configuration_value": Type, DefaultValue),
+ ```
+ The configuration value and identifier should usually be the same. The doc comment will be
+ automatically added to the lint documentation.
+2. Adding the configuration value to the lint impl struct:
+ 1. This first requires the definition of a lint impl struct. Lint impl structs are usually
+ generated with the `declare_lint_pass!` macro. This struct needs to be defined manually
+ to add some kind of metadata to it:
+ ```rust
+ // Generated struct definition
+ declare_lint_pass!(StructName => [
+ LINT_NAME
+ ]);
+
+ // New manual definition struct
+ #[derive(Copy, Clone)]
+ pub struct StructName {}
+
+ impl_lint_pass!(StructName => [
+ LINT_NAME
+ ]);
+ ```
+
+ 2. Next add the configuration value and a corresponding creation method like this:
+ ```rust
+ #[derive(Copy, Clone)]
+ pub struct StructName {
+ configuration_ident: Type,
+ }
+
+ // ...
+
+ impl StructName {
+ pub fn new(configuration_ident: Type) -> Self {
+ Self {
+ configuration_ident,
+ }
+ }
+ }
+ ```
+3. Passing the configuration value to the lint impl struct:
+
+ First find the struct construction in the [clippy_lints lib file](/clippy_lints/src/lib.rs).
+ The configuration value is now cloned or copied into a local value that is then passed to the
+ impl struct like this:
+ ```rust
+ // Default generated registration:
+ store.register_*_pass(|| box module::StructName);
+
+ // New registration with configuration value
+ let configuration_ident = conf.configuration_ident.clone();
+ store.register_*_pass(move || box module::StructName::new(configuration_ident));
+ ```
+
+ Congratulations the work is almost done. The configuration value can now be accessed
+ in the linting code via `self.configuration_ident`.
+
+4. Adding tests:
+ 1. The default configured value can be tested like any normal lint in [`tests/ui`](/tests/ui).
+ 2. The configuration itself will be tested separately in [`tests/ui-toml`](/tests/ui-toml).
+ Simply add a new subfolder with a fitting name. This folder contains a `clippy.toml` file
+ with the configuration value and a rust file that should be linted by Clippy. The test can
+ otherwise be written as usual.
+
+## Cheatsheet
+
+Here are some pointers to things you are likely going to need for every lint:
+
+* [Clippy utils][utils] - Various helper functions. Maybe the function you need
+ is already in here (`implements_trait`, `match_path`, `snippet`, etc)
+* [Clippy diagnostics][diagnostics]
+* [The `if_chain` macro][if_chain]
+* [`from_expansion`][from_expansion] and [`in_external_macro`][in_external_macro]
+* [`Span`][span]
+* [`Applicability`][applicability]
+* [Common tools for writing lints](common_tools_writing_lints.md) helps with common operations
+* [The rustc-dev-guide][rustc-dev-guide] explains a lot of internal compiler concepts
+* [The nightly rustc docs][nightly_docs] which has been linked to throughout
+ this guide
+
+For `EarlyLintPass` lints:
+
+* [`EarlyLintPass`][early_lint_pass]
+* [`rustc_ast::ast`][ast]
+
+For `LateLintPass` lints:
+
+* [`LateLintPass`][late_lint_pass]
+* [`Ty::TyKind`][ty]
+
+While most of Clippy's lint utils are documented, most of rustc's internals lack
+documentation currently. This is unfortunate, but in most cases you can probably
+get away with copying things from existing similar lints. If you are stuck,
+don't hesitate to ask on [Zulip] or in the issue/PR.
+
+[utils]: https://github.com/rust-lang/rust-clippy/blob/master/clippy_utils/src/lib.rs
+[if_chain]: https://docs.rs/if_chain/*/if_chain/
+[from_expansion]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.Span.html#method.from_expansion
+[in_external_macro]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/lint/fn.in_external_macro.html
+[span]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.Span.html
+[applicability]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_errors/enum.Applicability.html
+[rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org/
+[nightly_docs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/
+[ast]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/ast/index.html
+[ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/sty/index.html
+[Zulip]: https://rust-lang.zulipchat.com/#narrow/stream/clippy
projects / rustc.git / blobdiff