40 lines
1.3 KiB
Rust
40 lines
1.3 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_sugg;
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use clippy_utils::is_slice_of_primitives;
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use clippy_utils::source::snippet_with_applicability;
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use if_chain::if_chain;
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use rustc_ast::LitKind;
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use rustc_errors::Applicability;
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use rustc_hir as hir;
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use rustc_lint::LateContext;
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use rustc_span::source_map::Spanned;
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use super::GET_FIRST;
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pub(super) fn check<'tcx>(
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cx: &LateContext<'tcx>,
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expr: &'tcx hir::Expr<'_>,
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recv: &'tcx hir::Expr<'_>,
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arg: &'tcx hir::Expr<'_>,
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) {
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if_chain! {
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if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
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if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
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if cx.tcx.type_of(impl_id).is_slice();
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if let Some(_) = is_slice_of_primitives(cx, recv);
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if let hir::ExprKind::Lit(Spanned { node: LitKind::Int(0, _), .. }) = arg.kind;
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then {
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let mut app = Applicability::MachineApplicable;
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let slice_name = snippet_with_applicability(cx, recv.span, "..", &mut app);
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span_lint_and_sugg(
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cx,
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GET_FIRST,
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expr.span,
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&format!("accessing first element with `{slice_name}.get(0)`"),
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"try",
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format!("{slice_name}.first()"),
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app,
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);
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}
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}
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}
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