diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index d1e95db1de0cc..18adf37d08cf3 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -311,7 +311,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         error: &mut bool,
     ) {
         if let Some((if_span, msg)) = ret_reason {
-            err.span_label(if_span, msg.clone());
+            err.span_label(if_span, msg);
         } else if let ExprKind::Block(block, _) = then_expr.kind
             && let Some(expr) = block.expr
         {
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index ce0421ef62dd7..659716548d95d 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -452,7 +452,6 @@ impl<'a> Parser<'a> {
         let mut expected = self
             .expected_tokens
             .iter()
-            .cloned()
             .filter(|token| {
                 // Filter out suggestions that suggest the same token which was found and deemed incorrect.
                 fn is_ident_eq_keyword(found: &TokenKind, expected: &TokenType) -> bool {
@@ -464,7 +463,7 @@ impl<'a> Parser<'a> {
                     false
                 }
 
-                if *token != parser::TokenType::Token(self.token.kind.clone()) {
+                if **token != parser::TokenType::Token(self.token.kind.clone()) {
                     let eq = is_ident_eq_keyword(&self.token.kind, &token);
                     // If the suggestion is a keyword and the found token is an ident,
                     // the content of which are equal to the suggestion's content,
@@ -483,6 +482,7 @@ impl<'a> Parser<'a> {
                 }
                 false
             })
+            .cloned()
             .collect::<Vec<_>>();
         expected.sort_by_cached_key(|x| x.to_string());
         expected.dedup();
diff --git a/compiler/rustc_parse_format/src/lib.rs b/compiler/rustc_parse_format/src/lib.rs
index 0b65f400825ae..79aab47fbe717 100644
--- a/compiler/rustc_parse_format/src/lib.rs
+++ b/compiler/rustc_parse_format/src/lib.rs
@@ -893,7 +893,7 @@ impl<'a> Parser<'a> {
                 ParseError {
                     description: "expected format parameter to occur after `:`".to_owned(),
                     note: None,
-                    label: format!("expected `{}` to occur after `:`", alignment).to_owned(),
+                    label: format!("expected `{}` to occur after `:`", alignment),
                     span: pos.to(pos),
                     secondary_label: None,
                     suggestion: Suggestion::None,
diff --git a/src/tools/clippy/clippy_utils/src/diagnostics.rs b/src/tools/clippy/clippy_utils/src/diagnostics.rs
index 56978eb2ee805..5199959c0f2b3 100644
--- a/src/tools/clippy/clippy_utils/src/diagnostics.rs
+++ b/src/tools/clippy/clippy_utils/src/diagnostics.rs
@@ -84,9 +84,9 @@ pub fn span_lint_and_help<T: LintContext>(
     cx.span_lint(lint, span, msg.to_string(), |diag| {
         let help = help.to_string();
         if let Some(help_span) = help_span {
-            diag.span_help(help_span, help.to_string());
+            diag.span_help(help_span, help);
         } else {
-            diag.help(help.to_string());
+            diag.help(help);
         }
         docs_link(diag, lint);
     });