fix clippy errors

tracing-attributes/src/lib.rs

@@ -328,18 +328,16 @@ fn instrument_handle_recent_async_trait(
         let mut variable_rebindings = Vec::with_capacity(pre_statements.len());
         for stmt in pre_statements.iter() {
             if let Stmt::Local(Local {
-                pat,
+                pat: Pat::Ident(PatIdent { ident, .. }),
                 init: Some((_, source_path)),
                 ..
             }) = stmt
             {
-                if let Pat::Ident(PatIdent { ident, .. }) = pat {
-                    if let Expr::Path(source_path) = source_path.as_ref() {
-                        variable_rebindings.push((
-                            ident.clone(),
-                            Ident::new(&path_to_string(&source_path.path), source_path.span()),
-                        ));
-                    }
+                if let Expr::Path(source_path) = source_path.as_ref() {
+                    variable_rebindings.push((
+                        ident.clone(),
+                        Ident::new(&path_to_string(&source_path.path), source_path.span()),
+                    ));
                 }
             }
         }
@@ -395,8 +393,8 @@ fn instrument_handle_recent_async_trait(
 }
 
 // given an existing function, generate an instrumented version of that function
-fn gen_function<'a>(
-    input: &'a ItemFn,
+fn gen_function(
+    input: &ItemFn,
     args: InstrumentArgs,
     instrumented_function_name: String,
     variables_rebindings: Vec<(Ident, Ident)>,
@@ -549,7 +547,7 @@ fn gen_block<'a>(
         // eplace every use of a variable by its original name
         if let Some(Fields(ref mut fields)) = args.fields {
             let mut replacer = KnifeReplacer {
-                idents: param_names.clone(),
+                idents: param_names,
                 types: Vec::new(),
             };
 
@@ -1149,8 +1147,11 @@ struct KnifeReplacer<'a> {
 }
 
 impl<'a> syn::visit_mut::VisitMut for KnifeReplacer<'a> {
+    #[allow(clippy::cmp_owned)]
     fn visit_ident_mut(&mut self, id: &mut Ident) {
         for (old_ident, new_ident) in &self.idents {
+            // we deliberately compare strings because we want to ignore the spans
+            // If we apply clippy's lint, the behavior changes
             if id.to_string() == old_ident.to_string() {
                 *id = new_ident.clone();
             }
@@ -1184,17 +1185,19 @@ impl<'a> syn::visit::Visit<'a> for AsyncTraitBlockFinder<'a> {
     fn visit_block(&mut self, i: &'a Block) {
         let mut pre_statements = Vec::new();
         for (pos, stmt) in i.stmts.iter().enumerate() {
-            if let Stmt::Local(Local { pat, .. }) = stmt {
-                if let Pat::Type(PatType { pat: pat_type, .. }) = pat {
-                    if let Pat::Ident(PatIdent { ident, .. }) = pat_type.as_ref() {
-                        if ident == "__async_trait" {
-                            self.block = Some(AsyncTraitBlock {
-                                block: i,
-                                pre_statements,
-                                post_statements: i.stmts[pos + 1..].iter().collect(),
-                            });
-                            return;
-                        }
+            if let Stmt::Local(Local {
+                pat: Pat::Type(PatType { pat: pat_type, .. }),
+                ..
+            }) = stmt
+            {
+                if let Pat::Ident(PatIdent { ident, .. }) = pat_type.as_ref() {
+                    if ident == "__async_trait" {
+                        self.block = Some(AsyncTraitBlock {
+                            block: i,
+                            pre_statements,
+                            post_statements: i.stmts[pos + 1..].iter().collect(),
+                        });
+                        return;
                     }
                 }
             }