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useless_conversion: move all the impl to the same lint pass

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This commit is contained in:
Jason Newcomb 2025-07-14 12:02:19 -04:00
parent dcc790620a
commit 7796773d3e
2 changed files with 27 additions and 30 deletions
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4
clippy_lints/src/methods/mod.rs
View file

@ -5275,10 +5275,6 @@ impl Methods {
}
map_identity::check(cx, expr, recv, m_arg, name, span);
manual_inspect::check(cx, expr, m_arg, name, span, self.msrv);
crate::useless_conversion::check_function_application(cx, expr, recv, m_arg);
},
(sym::map_break | sym::map_continue, [m_arg]) => {
crate::useless_conversion::check_function_application(cx, expr, recv, m_arg);
},
(sym::map_or, [def, map]) => {
option_map_or_none::check(cx, expr, recv, def, map);

53
clippy_lints/src/useless_conversion.rs
View file

@ -176,6 +176,33 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {
}
},
ExprKind::MethodCall(path, recv, [arg], _) => {
if matches!(
path.ident.name,
sym::map | sym::map_err | sym::map_break | sym::map_continue
) && has_eligible_receiver(cx, recv, e)
&& (is_trait_item(cx, arg, sym::Into) || is_trait_item(cx, arg, sym::From))
&& let ty::FnDef(_, args) = cx.typeck_results().expr_ty(arg).kind()
&& let &[from_ty, to_ty] = args.into_type_list(cx.tcx).as_slice()
&& same_type_and_consts(from_ty, to_ty)
{
span_lint_and_then(
cx,
USELESS_CONVERSION,
e.span.with_lo(recv.span.hi()),
format!("useless conversion to the same type: `{from_ty}`"),
|diag| {
diag.suggest_remove_item(
cx,
e.span.with_lo(recv.span.hi()),
"consider removing",
Applicability::MachineApplicable,
);
},
);
}
},
ExprKind::MethodCall(name, recv, [], _) => {
if is_trait_method(cx, e, sym::Into) && name.ident.name == sym::into {
let a = cx.typeck_results().expr_ty(e);
@ -412,32 +439,6 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {
}
}
/// Check if `arg` is a `Into::into` or `From::from` applied to `receiver` to give `expr`, through a
/// higher-order mapping function.
pub fn check_function_application(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, arg: &Expr<'_>) {
if has_eligible_receiver(cx, recv, expr)
&& (is_trait_item(cx, arg, sym::Into) || is_trait_item(cx, arg, sym::From))
&& let ty::FnDef(_, args) = cx.typeck_results().expr_ty(arg).kind()
&& let &[from_ty, to_ty] = args.into_type_list(cx.tcx).as_slice()
&& same_type_and_consts(from_ty, to_ty)
{
span_lint_and_then(
cx,
USELESS_CONVERSION,
expr.span.with_lo(recv.span.hi()),
format!("useless conversion to the same type: `{from_ty}`"),
|diag| {
diag.suggest_remove_item(
cx,
expr.span.with_lo(recv.span.hi()),
"consider removing",
Applicability::MachineApplicable,
);
},
);
}
}
fn has_eligible_receiver(cx: &LateContext<'_>, recv: &Expr<'_>, expr: &Expr<'_>) -> bool {
if is_inherent_method_call(cx, expr) {
matches!(