45 lines
1.3 KiB
Rust
45 lines
1.3 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_help;
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use rustc_ast::ast::{BindingAnnotation, Pat, PatKind};
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use rustc_lint::{EarlyContext, EarlyLintPass};
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use rustc_session::{declare_lint_pass, declare_tool_lint};
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declare_clippy_lint! {
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/// ### What it does
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/// Checks for usages of the `ref` keyword.
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/// ### Why is this bad?
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/// The `ref` keyword can be confusing for people unfamiliar with it, and often
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/// it is more concise to use `&` instead.
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/// ### Example
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/// ```rust
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/// let opt = Some(5);
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/// if let Some(ref foo) = opt {}
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/// ```
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/// Use instead:
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/// ```rust
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/// let opt = Some(5);
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/// if let Some(foo) = &opt {}
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/// ```
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#[clippy::version = "1.71.0"]
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pub REF_PATTERNS,
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restriction,
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"use of a ref pattern, e.g. Some(ref value)"
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}
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declare_lint_pass!(RefPatterns => [REF_PATTERNS]);
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impl EarlyLintPass for RefPatterns {
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fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &Pat) {
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if let PatKind::Ident(BindingAnnotation::REF, _, _) = pat.kind
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&& !pat.span.from_expansion()
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{
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span_lint_and_help(
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cx,
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REF_PATTERNS,
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pat.span,
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"usage of ref pattern",
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None,
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"consider using `&` for clarity instead",
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);
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}
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}
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}
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