| use clippy_utils::diagnostics::span_lint_and_sugg; |
| use clippy_utils::is_trait_method; |
| use clippy_utils::ty::has_iter_method; |
| use if_chain::if_chain; |
| use rustc_errors::Applicability; |
| use rustc_hir as hir; |
| use rustc_lint::LateContext; |
| use rustc_middle::ty::{self, Ty}; |
| use rustc_span::Span; |
| use rustc_span::symbol::{sym, Symbol}; |
| |
| use super::INTO_ITER_ON_REF; |
| |
| pub(super) fn check( |
| cx: &LateContext<'_>, |
| expr: &hir::Expr<'_>, |
| method_span: Span, |
| method_name: Symbol, |
| receiver: &hir::Expr<'_>, |
| ) { |
| let self_ty = cx.typeck_results().expr_ty_adjusted(receiver); |
| if_chain! { |
| if let ty::Ref(..) = self_ty.kind(); |
| if method_name == sym::into_iter; |
| if is_trait_method(cx, expr, sym::IntoIterator); |
| if let Some((kind, method_name)) = ty_has_iter_method(cx, self_ty); |
| then { |
| span_lint_and_sugg( |
| cx, |
| INTO_ITER_ON_REF, |
| method_span, |
| &format!( |
| "this `.into_iter()` call is equivalent to `.{method_name}()` and will not consume the `{kind}`", |
| ), |
| "call directly", |
| method_name.to_string(), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| } |
| |
| fn ty_has_iter_method(cx: &LateContext<'_>, self_ref_ty: Ty<'_>) -> Option<(Symbol, &'static str)> { |
| has_iter_method(cx, self_ref_ty).map(|ty_name| { |
| let ty::Ref(_, _, mutbl) = self_ref_ty.kind() else { |
| unreachable!() |
| }; |
| let method_name = match mutbl { |
| hir::Mutability::Not => "iter", |
| hir::Mutability::Mut => "iter_mut", |
| }; |
| (ty_name, method_name) |
| }) |
| } |