Function clippy_utils::diagnostics::span_lint_and_note

pub fn span_lint_and_note<T: LintContext>(
    cx: &T,
    lint: &'static Lint,
    span: impl Into<MultiSpan>,
    msg: impl Into<DiagMessage>,
    note_span: Option<Span>,
    note: impl Into<SubdiagMessage>
)

Like span_lint but with a note section instead of a help message.

The note message is presented separately from the main lint message and is attached to a specific span:

If you change the signature, remember to update the internal lint CollapsibleCalls

NOTE: Lint emissions are always bound to a node in the HIR, which is used to determine the lint level. For the span_lint_and_note function, the node that was passed into the LintPass::check_* function is used.

If you’re emitting the lint at the span of a different node than the one provided by the LintPass::check_* function, consider using span_lint_hir_and_then instead. This is needed for #[allow] and #[expect] attributes to work on the node highlighted in the displayed warning.

If you’re unsure which function you should use, you can test if the #[allow] attribute works where you would expect it to. If it doesn’t, you likely need to use span_lint_hir_and_then instead.

Example

error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing.
  --> tests/ui/drop_forget_ref.rs:10:5
   |
10 |     forget(&SomeStruct);
   |     ^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D clippy::forget-ref` implied by `-D warnings`
note: argument has type &SomeStruct
  --> tests/ui/drop_forget_ref.rs:10:12
   |
10 |     forget(&SomeStruct);
   |            ^^^^^^^^^^^