86 lines
2.5 KiB
Rust
86 lines
2.5 KiB
Rust
use clippy_config::msrvs::{self, Msrv};
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use clippy_utils::diagnostics::span_lint_and_sugg;
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use rustc_ast::ast::{Expr, ExprKind};
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use rustc_errors::Applicability;
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use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
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use rustc_middle::lint::in_external_macro;
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use rustc_session::impl_lint_pass;
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declare_clippy_lint! {
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/// ### What it does
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/// Checks for fields in struct literals where shorthands
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/// could be used.
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///
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/// ### Why is this bad?
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/// If the field and variable names are the same,
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/// the field name is redundant.
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///
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/// ### Example
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/// ```no_run
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/// let bar: u8 = 123;
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///
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/// struct Foo {
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/// bar: u8,
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/// }
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///
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/// let foo = Foo { bar: bar };
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/// ```
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/// the last line can be simplified to
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/// ```ignore
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/// let foo = Foo { bar };
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/// ```
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#[clippy::version = "pre 1.29.0"]
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pub REDUNDANT_FIELD_NAMES,
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style,
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"checks for fields in struct literals where shorthands could be used"
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}
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pub struct RedundantFieldNames {
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msrv: Msrv,
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}
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impl RedundantFieldNames {
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#[must_use]
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pub fn new(msrv: Msrv) -> Self {
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Self { msrv }
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}
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}
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impl_lint_pass!(RedundantFieldNames => [REDUNDANT_FIELD_NAMES]);
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impl EarlyLintPass for RedundantFieldNames {
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fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
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if !self.msrv.meets(msrvs::FIELD_INIT_SHORTHAND) {
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return;
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}
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if in_external_macro(cx.sess(), expr.span) {
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return;
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}
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if let ExprKind::Struct(ref se) = expr.kind {
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for field in &se.fields {
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if field.is_shorthand {
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continue;
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}
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if let ExprKind::Path(None, path) = &field.expr.kind {
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if path.segments.len() == 1
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&& path.segments[0].ident == field.ident
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&& path.segments[0].args.is_none()
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{
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span_lint_and_sugg(
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cx,
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REDUNDANT_FIELD_NAMES,
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field.span,
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"redundant field names in struct initialization",
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"replace it with",
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field.ident.to_string(),
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Applicability::MachineApplicable,
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);
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}
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}
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}
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}
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}
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extract_msrv_attr!(EarlyContext);
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}
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