Rollup merge of #88860 - nbdd0121:panic, r=m-ou-se

[rust.git] / clippy_lints / src / copy_iterator.rs

diff --git a/clippy_lints/src/copy_iterator.rs b/clippy_lints/src/copy_iterator.rs
index c8d8da487856dc0e743031fcda48e08ac144247c..c2e9e8b3ab7f39d226f32df4449cfef0190cacbe 100644 (file)
--- a/clippy_lints/src/copy_iterator.rs
+++ b/clippy_lints/src/copy_iterator.rs
@@ -1,19 +1,22 @@
-use crate::utils::{is_copy, match_path, paths, span_note_and_lint};
-use rustc::declare_lint_pass;
-use rustc::hir::{Item, ItemKind};
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc_session::declare_tool_lint;
+use clippy_utils::diagnostics::span_lint_and_note;
+use clippy_utils::ty::is_copy;
+use rustc_hir::{Impl, Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
+
+use if_chain::if_chain;
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for types that implement `Copy` as well as
+    /// ### What it does
+    /// Checks for types that implement `Copy` as well as
     /// `Iterator`.
     ///
-    /// **Why is this bad?** Implicit copies can be confusing when working with
+    /// ### Why is this bad?
+    /// Implicit copies can be confusing when working with
     /// iterator combinators.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Example
     /// ```rust,ignore
     /// #[derive(Copy, Clone)]
     /// struct Countdown(u8);
@@ -32,18 +35,24 @@
 
 declare_lint_pass!(CopyIterator => [COPY_ITERATOR]);
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CopyIterator {
-    fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
-        if let ItemKind::Impl(_, _, _, _, Some(ref trait_ref), _, _) = item.kind {
-            let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
-
-            if is_copy(cx, ty) && match_path(&trait_ref.path, &paths::ITERATOR) {
-                span_note_and_lint(
+impl<'tcx> LateLintPass<'tcx> for CopyIterator {
+    fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+        if_chain! {
+            if let ItemKind::Impl(Impl {
+                of_trait: Some(ref trait_ref),
+                ..
+            }) = item.kind;
+            let ty = cx.tcx.type_of(item.def_id);
+            if is_copy(cx, ty);
+            if let Some(trait_id) = trait_ref.trait_def_id();
+            if cx.tcx.is_diagnostic_item(sym::Iterator, trait_id);
+            then {
+                span_lint_and_note(
                     cx,
                     COPY_ITERATOR,
                     item.span,
                     "you are implementing `Iterator` on a `Copy` type",
-                    item.span,
+                    None,
                     "consider implementing `IntoIterator` instead",
                 );
             }