BPF: review fixes

[rust.git] / src / tools / clippy / doc / adding_lints.md

diff --git a/src/tools/clippy/doc/adding_lints.md b/src/tools/clippy/doc/adding_lints.md
index 50f0d724016ff1b33039de9ae471d68b04fc0ced..5a06afedbf4c2e7b86afff20847a30456b7a6d41 100644 (file)
--- a/src/tools/clippy/doc/adding_lints.md
+++ b/src/tools/clippy/doc/adding_lints.md
@@ -390,17 +390,23 @@ pass.
 
 ## 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,
+Sometimes a lint makes suggestions that require a certain version of Rust. For example, the `manual_strip` lint suggests
+using `str::strip_prefix` and `str::strip_suffix` which is only available after Rust 1.45. In such cases, you need to
+ensure that the MSRV configured for the project is >= the MSRV of the required Rust feature. If multiple features are
+required, just use the one with a lower MSRV.
+
+First, add an MSRV alias for the required feature in [`clippy_utils::msrvs`](/clippy_utils/src/msrvs.rs). This can be
+accessed later as `msrvs::STR_STRIP_PREFIX`, for example.
 
 ```rust
-const MANUAL_STRIP_MSRV: RustcVersion = RustcVersion::new(1, 45, 0);
+msrv_aliases! {
+    ..
+    1,45,0 { STR_STRIP_PREFIX }
+}
 ```
 
-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`
+In order to access the project-configured MSRV, you need to have an `msrv` field in the LintPass struct, and a
+constructor to initialize the field. The `msrv` value is passed to the constructor in `clippy_lints/lib.rs`.
 
 ```rust
 pub struct ManualStrip {
@@ -415,11 +421,11 @@ impl ManualStrip {
 }
 ```
 
-The project's MSRV can then be matched against the lint's `msrv` in the LintPass
+The project's MSRV can then be matched against the feature MSRV in the LintPass
 using the `meets_msrv` utility function.
 
 ``` rust
-if !meets_msrv(self.msrv.as_ref(), &MANUAL_STRIP_MSRV) {
+if !meets_msrv(self.msrv.as_ref(), &msrvs::STR_STRIP_PREFIX) {
     return;
 }
 ```
@@ -448,7 +454,7 @@ in `clippy_lints/src/utils/conf.rs`:
 ```rust
 define_Conf! {
     /// Lint: LIST, OF, LINTS, <THE_NEWLY_ADDED_LINT>. The minimum rust version that the project supports
-    (msrv, "msrv": Option<String>, None),
+    (msrv: Option<String> = None),
     ...
 }
 ```
@@ -556,7 +562,7 @@ in the following steps:
     like this:
     ```rust
     /// Lint: LINT_NAME. <The configuration field doc comment>
-    (configuration_ident, "configuration_value": Type, DefaultValue),
+    (configuration_ident: Type = DefaultValue),
     ```
     The configuration value and identifier should usually be the same. The doc comment will be
     automatically added to the lint documentation.