X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Finherent_to_string.rs;h=b62fad4bd39585e049fc5eef3428be53780bc875;hb=d9c3f0d69029cd9ffd97fe2d1b7a3701ea0ac51a;hp=5a577460c42409709fb47a316e563f329e5d4734;hpb=0480ff861a66239f5cd8496f12dc99da70124013;p=rust.git

diff --git a/clippy_lints/src/inherent_to_string.rs b/clippy_lints/src/inherent_to_string.rs
index 5a577460c42..b62fad4bd39 100644
--- a/clippy_lints/src/inherent_to_string.rs
+++ b/clippy_lints/src/inherent_to_string.rs
@@ -1,22 +1,23 @@
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::{get_trait_def_id, paths, return_ty, trait_ref_of_method};
 use if_chain::if_chain;
 use rustc_hir::{ImplItem, ImplItemKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-
-use crate::utils::{
-    get_trait_def_id, is_type_diagnostic_item, implements_trait, paths, return_ty, span_lint_and_help, trait_ref_of_method,
-    walk_ptrs_ty,
-};
+use rustc_span::sym;
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for the definition of inherent methods with a signature of `to_string(&self) -> String`.
-    ///
-    /// **Why is this bad?** This method is also implicitly defined if a type implements the `Display` trait. As the functionality of `Display` is much more versatile, it should be preferred.
+    /// ### What it does
+    /// Checks for the definition of inherent methods with a signature of `to_string(&self) -> String`.
     ///
-    /// **Known problems:** None
+    /// ### Why is this bad?
+    /// This method is also implicitly defined if a type implements the `Display` trait. As the functionality of `Display` is much more versatile, it should be preferred.
     ///
-    /// ** Example:**
+    /// ### Known problems
+    /// None
     ///
+    /// ### Example
     /// ```rust
     /// // Bad
     /// pub struct A;
@@ -46,14 +47,16 @@
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for the definition of inherent methods with a signature of `to_string(&self) -> String` and if the type implementing this method also implements the `Display` trait.
-    ///
-    /// **Why is this bad?** This method is also implicitly defined if a type implements the `Display` trait. The less versatile inherent method will then shadow the implementation introduced by `Display`.
+    /// ### What it does
+    /// Checks for the definition of inherent methods with a signature of `to_string(&self) -> String` and if the type implementing this method also implements the `Display` trait.
     ///
-    /// **Known problems:** None
+    /// ### Why is this bad?
+    /// This method is also implicitly defined if a type implements the `Display` trait. The less versatile inherent method will then shadow the implementation introduced by `Display`.
     ///
-    /// ** Example:**
+    /// ### Known problems
+    /// None
     ///
+    /// ### Example
     /// ```rust
     /// // Bad
     /// use std::fmt;
@@ -92,8 +95,8 @@
 
 declare_lint_pass!(InherentToString => [INHERENT_TO_STRING, INHERENT_TO_STRING_SHADOW_DISPLAY]);
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InherentToString {
-    fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx ImplItem<'_>) {
+impl<'tcx> LateLintPass<'tcx> for InherentToString {
+    fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<'_>) {
         if impl_item.span.from_expansion() {
             return;
         }
@@ -105,12 +108,13 @@ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx ImplI
             let decl = &signature.decl;
             if decl.implicit_self.has_implicit_self();
             if decl.inputs.len() == 1;
+            if impl_item.generics.params.is_empty();
 
             // Check if return type is String
-            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id), sym!(string_type));
+            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::string_type);
 
             // Filters instances of to_string which are required by a trait
-            if trait_ref_of_method(cx, impl_item.hir_id).is_none();
+            if trait_ref_of_method(cx, impl_item.hir_id()).is_none();
 
             then {
                 show_lint(cx, impl_item);
@@ -119,13 +123,12 @@ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx ImplI
     }
 }
 
-fn show_lint(cx: &LateContext<'_, '_>, item: &ImplItem<'_>) {
+fn show_lint(cx: &LateContext<'_>, item: &ImplItem<'_>) {
     let display_trait_id = get_trait_def_id(cx, &paths::DISPLAY_TRAIT).expect("Failed to get trait ID of `Display`!");
 
     // Get the real type of 'self'
-    let fn_def_id = cx.tcx.hir().local_def_id(item.hir_id);
-    let self_type = cx.tcx.fn_sig(fn_def_id).input(0);
-    let self_type = walk_ptrs_ty(self_type.skip_binder());
+    let self_type = cx.tcx.fn_sig(item.def_id).input(0);
+    let self_type = self_type.skip_binder().peel_refs();
 
     // Emit either a warning or an error
     if implements_trait(cx, self_type, display_trait_id, &[]) {
@@ -138,7 +141,7 @@ fn show_lint(cx: &LateContext<'_, '_>, item: &ImplItem<'_>) {
                 self_type.to_string()
             ),
             None,
-            &format!("remove the inherent method from type `{}`", self_type.to_string())
+            &format!("remove the inherent method from type `{}`", self_type.to_string()),
         );
     } else {
         span_lint_and_help(