extract helper functions

too many lines no more!

Author: ada4a

clippy_lints/src/non_canonical_impls.rs

@@ -5,9 +5,9 @@ use clippy_utils::{
 };
 use rustc_errors::Applicability;
 use rustc_hir::def_id::LocalDefId;
-use rustc_hir::{Expr, ExprKind, ImplItem, ImplItemKind, LangItem, Node, UnOp};
+use rustc_hir::{Block, Body, Expr, ExprKind, ImplItem, ImplItemKind, Item, LangItem, Node, UnOp};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::ty::EarlyBinder;
+use rustc_middle::ty::{EarlyBinder, TraitRef};
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
 use rustc_span::symbol::kw;
@@ -112,7 +112,6 @@ declare_clippy_lint! {
 declare_lint_pass!(NonCanonicalImpls => [NON_CANONICAL_CLONE_IMPL, NON_CANONICAL_PARTIAL_ORD_IMPL]);
 
 impl LateLintPass<'_> for NonCanonicalImpls {
-    #[expect(clippy::too_many_lines)]
     fn check_impl_item<'tcx>(&mut self, cx: &LateContext<'tcx>, impl_item: &ImplItem<'tcx>) {
         if let Node::Item(item) = cx.tcx.parent_hir_node(impl_item.hir_id())
             && let Some(trait_impl) = cx.tcx.impl_trait_ref(item.owner_id).map(EarlyBinder::skip_binder)
@@ -128,114 +127,127 @@ impl LateLintPass<'_> for NonCanonicalImpls {
                 && let Some(copy_def_id) = cx.tcx.get_diagnostic_item(sym::Copy)
                 && implements_trait(cx, trait_impl.self_ty(), copy_def_id, &[])
             {
-                if impl_item.ident.name == sym::clone {
-                    if block.stmts.is_empty()
-                        && let Some(expr) = block.expr
-                        && let ExprKind::Unary(UnOp::Deref, deref) = expr.kind
-                        && let ExprKind::Path(qpath) = deref.kind
-                        && last_path_segment(&qpath).ident.name == kw::SelfLower
-                    {
-                    } else {
-                        span_lint_and_sugg(
-                            cx,
-                            NON_CANONICAL_CLONE_IMPL,
-                            block.span,
-                            "non-canonical implementation of `clone` on a `Copy` type",
-                            "change this to",
-                            "{ *self }".to_owned(),
-                            Applicability::MaybeIncorrect,
-                        );
-
-                        return;
-                    }
-                }
-
-                if impl_item.ident.name == sym::clone_from {
-                    span_lint_and_sugg(
-                        cx,
-                        NON_CANONICAL_CLONE_IMPL,
-                        impl_item.span,
-                        "unnecessary implementation of `clone_from` on a `Copy` type",
-                        "remove it",
-                        String::new(),
-                        Applicability::MaybeIncorrect,
-                    );
-                }
+                check_clone_on_copy(cx, impl_item, block);
             } else if trait_name == Some(sym::PartialOrd)
                 && impl_item.ident.name == sym::partial_cmp
                 && let Some(ord_def_id) = cx.tcx.get_diagnostic_item(sym::Ord)
                 && implements_trait(cx, trait_impl.self_ty(), ord_def_id, &[])
             {
-                // If the `cmp` call likely needs to be fully qualified in the suggestion
-                // (like `std::cmp::Ord::cmp`). It's unfortunate we must put this here but we can't
-                // access `cmp_expr` in the suggestion without major changes, as we lint in `else`.
-                let mut needs_fully_qualified = false;
+                check_partial_ord_on_ord(cx, impl_item, item, &trait_impl, body, block);
+            }
+        }
+    }
+}
 
-                if block.stmts.is_empty()
-                    && let Some(expr) = block.expr
-                    && expr_is_cmp(cx, expr, impl_item, &mut needs_fully_qualified)
-                {
-                    return;
-                }
-                // Fix #12683, allow [`needless_return`] here
-                else if block.expr.is_none()
-                    && let Some(stmt) = block.stmts.first()
-                    && let rustc_hir::StmtKind::Semi(Expr {
-                        kind: ExprKind::Ret(Some(ret)),
-                        ..
-                    }) = stmt.kind
-                    && expr_is_cmp(cx, ret, impl_item, &mut needs_fully_qualified)
-                {
-                    return;
-                }
-                // If `Self` and `Rhs` are not the same type, bail. This makes creating a valid
-                // suggestion tons more complex.
-                else if let [lhs, rhs, ..] = trait_impl.args.as_slice()
-                    && lhs != rhs
-                {
-                    return;
-                }
+fn check_clone_on_copy(cx: &LateContext<'_>, impl_item: &ImplItem<'_>, block: &Block<'_>) {
+    if impl_item.ident.name == sym::clone {
+        if block.stmts.is_empty()
+            && let Some(expr) = block.expr
+            && let ExprKind::Unary(UnOp::Deref, deref) = expr.kind
+            && let ExprKind::Path(qpath) = deref.kind
+            && last_path_segment(&qpath).ident.name == kw::SelfLower
+        {
+        } else {
+            span_lint_and_sugg(
+                cx,
+                NON_CANONICAL_CLONE_IMPL,
+                block.span,
+                "non-canonical implementation of `clone` on a `Copy` type",
+                "change this to",
+                "{ *self }".to_owned(),
+                Applicability::MaybeIncorrect,
+            );
+        }
+    }
 
-                span_lint_and_then(
-                    cx,
-                    NON_CANONICAL_PARTIAL_ORD_IMPL,
-                    item.span,
-                    "non-canonical implementation of `partial_cmp` on an `Ord` type",
-                    |diag| {
-                        let [_, other] = body.params else {
-                            return;
-                        };
-                        let Some(std_or_core) = std_or_core(cx) else {
-                            return;
-                        };
+    if impl_item.ident.name == sym::clone_from {
+        span_lint_and_sugg(
+            cx,
+            NON_CANONICAL_CLONE_IMPL,
+            impl_item.span,
+            "unnecessary implementation of `clone_from` on a `Copy` type",
+            "remove it",
+            String::new(),
+            Applicability::MaybeIncorrect,
+        );
+    }
+}
 
-                        let suggs = match (other.pat.simple_ident(), needs_fully_qualified) {
-                            (Some(other_ident), true) => vec![(
-                                block.span,
-                                format!("{{ Some({std_or_core}::cmp::Ord::cmp(self, {})) }}", other_ident.name),
-                            )],
-                            (Some(other_ident), false) => {
-                                vec![(block.span, format!("{{ Some(self.cmp({})) }}", other_ident.name))]
-                            },
-                            (None, true) => vec![
-                                (
-                                    block.span,
-                                    format!("{{ Some({std_or_core}::cmp::Ord::cmp(self, other)) }}"),
-                                ),
-                                (other.pat.span, "other".to_owned()),
-                            ],
-                            (None, false) => vec![
-                                (block.span, "{ Some(self.cmp(other)) }".to_owned()),
-                                (other.pat.span, "other".to_owned()),
-                            ],
-                        };
+fn check_partial_ord_on_ord<'tcx>(
+    cx: &LateContext<'tcx>,
+    impl_item: &ImplItem<'_>,
+    item: &Item<'_>,
+    trait_impl: &TraitRef<'_>,
+    body: &Body<'_>,
+    block: &Block<'tcx>,
+) {
+    // If the `cmp` call likely needs to be fully qualified in the suggestion
+    // (like `std::cmp::Ord::cmp`). It's unfortunate we must put this here but we can't
+    // access `cmp_expr` in the suggestion without major changes, as we lint in `else`.
 
-                        diag.multipart_suggestion("change this to", suggs, Applicability::Unspecified);
-                    },
-                );
-            }
-        }
+    let mut needs_fully_qualified = false;
+    if block.stmts.is_empty()
+        && let Some(expr) = block.expr
+        && expr_is_cmp(cx, expr, impl_item, &mut needs_fully_qualified)
+    {
+        return;
+    }
+    // Fix #12683, allow [`needless_return`] here
+    else if block.expr.is_none()
+        && let Some(stmt) = block.stmts.first()
+        && let rustc_hir::StmtKind::Semi(Expr {
+            kind: ExprKind::Ret(Some(ret)),
+            ..
+        }) = stmt.kind
+        && expr_is_cmp(cx, ret, impl_item, &mut needs_fully_qualified)
+    {
+        return;
+    }
+    // If `Self` and `Rhs` are not the same type, bail. This makes creating a valid
+    // suggestion tons more complex.
+    else if let [lhs, rhs, ..] = trait_impl.args.as_slice()
+        && lhs != rhs
+    {
+        return;
     }
+
+    span_lint_and_then(
+        cx,
+        NON_CANONICAL_PARTIAL_ORD_IMPL,
+        item.span,
+        "non-canonical implementation of `partial_cmp` on an `Ord` type",
+        |diag| {
+            let [_, other] = body.params else {
+                return;
+            };
+            let Some(std_or_core) = std_or_core(cx) else {
+                return;
+            };
+
+            let suggs = match (other.pat.simple_ident(), needs_fully_qualified) {
+                (Some(other_ident), true) => vec![(
+                    block.span,
+                    format!("{{ Some({std_or_core}::cmp::Ord::cmp(self, {})) }}", other_ident.name),
+                )],
+                (Some(other_ident), false) => {
+                    vec![(block.span, format!("{{ Some(self.cmp({})) }}", other_ident.name))]
+                },
+                (None, true) => vec![
+                    (
+                        block.span,
+                        format!("{{ Some({std_or_core}::cmp::Ord::cmp(self, other)) }}"),
+                    ),
+                    (other.pat.span, "other".to_owned()),
+                ],
+                (None, false) => vec![
+                    (block.span, "{ Some(self.cmp(other)) }".to_owned()),
+                    (other.pat.span, "other".to_owned()),
+                ],
+            };
+
+            diag.multipart_suggestion("change this to", suggs, Applicability::Unspecified);
+        },
+    );
 }
 
 /// Return true if `expr_kind` is a `cmp` call.