misc

Author: ada4a

clippy_lints/src/use_self.rs

@@ -9,13 +9,14 @@ use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{InferKind, Visitor, VisitorExt, walk_ty};
 use rustc_hir::{
-    self as hir, AmbigArg, Expr, ExprKind, FnRetTy, FnSig, GenericArgsParentheses, GenericParam, GenericParamKind,
-    HirId, Impl, ImplItemKind, Item, ItemKind, Pat, PatExpr, PatExprKind, PatKind, Path, QPath, Ty, TyKind,
+    self as hir, AmbigArg, Expr, ExprKind, FnRetTy, FnSig, GenericArgsParentheses, GenericParamKind, HirId, Impl,
+    ImplItemKind, Item, ItemKind, Pat, PatExpr, PatExprKind, PatKind, Path, QPath, Ty, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::Ty as MiddleTy;
 use rustc_session::impl_lint_pass;
 use rustc_span::Span;
+use std::iter;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -101,17 +102,11 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             let types_to_skip = generics
                 .params
                 .iter()
-                .filter_map(|param| match param {
-                    GenericParam {
-                        kind:
-                            GenericParamKind::Const {
-                                ty: Ty { hir_id, .. }, ..
-                            },
-                        ..
-                    } => Some(*hir_id),
+                .filter_map(|param| match param.kind {
+                    GenericParamKind::Const { ty, .. } => Some(ty.hir_id),
                     _ => None,
                 })
-                .chain(std::iter::once(self_ty.hir_id))
+                .chain([self_ty.hir_id])
                 .collect();
             StackItem::Check {
                 impl_id: item.owner_id.def_id,
@@ -212,9 +207,9 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             && let impl_ty = cx.tcx.type_of(impl_id).instantiate_identity()
             && same_type_and_consts(ty, impl_ty)
             // Ensure the type we encounter and the one from the impl have the same lifetime parameters. It may be that
-            // the lifetime parameters of `ty` are elided (`impl<'a> Foo<'a> { fn new() -> Self { Foo{..} } }`, in
+            // the lifetime parameters of `ty` are elided (`impl<'a> Foo<'a> { fn new() -> Self { Foo{..} } }`), in
             // which case we must still trigger the lint.
-            && (has_no_lifetime(ty) || same_lifetimes(ty, impl_ty))
+            && (!has_lifetime(ty) || same_lifetimes(ty, impl_ty))
             && self.msrv.meets(cx, msrvs::TYPE_ALIAS_ENUM_VARIANTS)
         {
             span_lint(cx, hir_ty.span);
@@ -227,18 +222,16 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             && cx.typeck_results().expr_ty(expr) == cx.tcx.type_of(impl_id).instantiate_identity()
             && self.msrv.meets(cx, msrvs::TYPE_ALIAS_ENUM_VARIANTS)
         {
-        } else {
-            return;
-        }
-        match expr.kind {
-            ExprKind::Struct(QPath::Resolved(_, path), ..) => check_path(cx, path),
-            ExprKind::Call(fun, _) => {
-                if let ExprKind::Path(QPath::Resolved(_, path)) = fun.kind {
-                    check_path(cx, path);
-                }
-            },
-            ExprKind::Path(QPath::Resolved(_, path)) => check_path(cx, path),
-            _ => (),
+            match expr.kind {
+                ExprKind::Struct(QPath::Resolved(_, path), ..) => check_path(cx, path),
+                ExprKind::Call(fun, _) => {
+                    if let ExprKind::Path(QPath::Resolved(_, path)) = fun.kind {
+                        check_path(cx, path);
+                    }
+                },
+                ExprKind::Path(QPath::Resolved(_, path)) => check_path(cx, path),
+                _ => (),
+            }
         }
     }
 
@@ -308,36 +301,32 @@ fn lint_path_to_variant(cx: &LateContext<'_>, path: &Path<'_>) {
     }
 }
 
-/// Returns `true` if types `a` and `b` have the same lifetime parameters, otherwise returns
-/// `false`.
+/// Checks whether types `a` and `b` have the same lifetime parameters.
 ///
 /// This function does not check that types `a` and `b` are the same types.
 fn same_lifetimes<'tcx>(a: MiddleTy<'tcx>, b: MiddleTy<'tcx>) -> bool {
     use rustc_middle::ty::{Adt, GenericArgKind};
-    match (&a.kind(), &b.kind()) {
-        (&Adt(_, args_a), &Adt(_, args_b)) => {
-            args_a
-                .iter()
-                .zip(args_b.iter())
-                .all(|(arg_a, arg_b)| match (arg_a.kind(), arg_b.kind()) {
-                    // TODO: Handle inferred lifetimes
-                    (GenericArgKind::Lifetime(inner_a), GenericArgKind::Lifetime(inner_b)) => inner_a == inner_b,
-                    (GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => same_lifetimes(type_a, type_b),
-                    _ => true,
-                })
+    match (a.kind(), b.kind()) {
+        (Adt(_, args_a), Adt(_, args_b)) => {
+            iter::zip(*args_a, *args_b).all(|(arg_a, arg_b)| match (arg_a.kind(), arg_b.kind()) {
+                // TODO: Handle inferred lifetimes
+                (GenericArgKind::Lifetime(inner_a), GenericArgKind::Lifetime(inner_b)) => inner_a == inner_b,
+                (GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => same_lifetimes(type_a, type_b),
+                _ => true,
+            })
         },
         _ => a == b,
     }
 }
 
-/// Returns `true` if `ty` has no lifetime parameter, otherwise returns `false`.
-fn has_no_lifetime(ty: MiddleTy<'_>) -> bool {
+/// Checks whether `ty` has lifetime parameters.
+fn has_lifetime(ty: MiddleTy<'_>) -> bool {
     use rustc_middle::ty::{Adt, GenericArgKind};
     match ty.kind() {
-        &Adt(_, args) => !args
+        Adt(_, args) => args
             .iter()
             // TODO: Handle inferred lifetimes
             .any(|arg| matches!(arg.kind(), GenericArgKind::Lifetime(..))),
-        _ => true,
+        _ => false,
     }
 }

clippy_utils/src/ty/mod.rs

@@ -522,16 +522,11 @@ pub fn same_type_and_consts<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
                 return false;
             }
 
-            args_a
-                .iter()
-                .zip(args_b.iter())
-                .all(|(arg_a, arg_b)| match (arg_a.kind(), arg_b.kind()) {
-                    (GenericArgKind::Const(inner_a), GenericArgKind::Const(inner_b)) => inner_a == inner_b,
-                    (GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => {
-                        same_type_and_consts(type_a, type_b)
-                    },
-                    _ => true,
-                })
+            iter::zip(*args_a, *args_b).all(|(arg_a, arg_b)| match (arg_a.kind(), arg_b.kind()) {
+                (GenericArgKind::Const(inner_a), GenericArgKind::Const(inner_b)) => inner_a == inner_b,
+                (GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => same_type_and_consts(type_a, type_b),
+                _ => true,
+            })
         },
         _ => a == b,
     }