Minor clippy perf fixes

crates/hir_def/src/resolver.rs

@@ -640,8 +640,7 @@ pub trait HasResolver: Copy {
 impl HasResolver for ModuleId {
     fn resolver(self, db: &dyn DefDatabase) -> Resolver {
         let mut def_map = self.def_map(db);
-        let mut modules = Vec::new();
-        modules.push((def_map.clone(), self.local_id));
+        let mut modules = vec![(def_map.clone(), self.local_id)];
         while let Some(parent) = def_map.parent() {
             def_map = parent.def_map(db);
             modules.push((def_map.clone(), parent.local_id));

crates/hir_expand/src/builtin_macro.rs

@@ -202,7 +202,7 @@ fn assert_expand(
 
     let arg_tts = args.into_iter().flat_map(|arg| {
         quote! { &(#arg), }
-    }.token_trees).collect::<Vec<_>>();
+    }.token_trees);
 
     let expanded = quote! {
         { { (##arg_tts); } }
@@ -254,7 +254,7 @@ fn format_args_expand(
     let _format_string = args.remove(0);
     let arg_tts = args.into_iter().flat_map(|arg| {
         quote! { std::fmt::ArgumentV1::new(&(#arg), std::fmt::Display::fmt), }
-    }.token_trees).collect::<Vec<_>>();
+    }.token_trees);
     let expanded = quote! {
         std::fmt::Arguments::new_v1(&[], &[##arg_tts])
     };

crates/hir_ty/src/diagnostics/expr.rs

@@ -56,7 +56,7 @@ impl BodyValidationDiagnostic {
     pub fn collect(db: &dyn HirDatabase, owner: DefWithBodyId) -> Vec<BodyValidationDiagnostic> {
         let _p = profile::span("BodyValidationDiagnostic::collect");
         let infer = db.infer(owner);
-        let mut validator = ExprValidator::new(owner, infer.clone());
+        let mut validator = ExprValidator::new(owner, infer);
         validator.validate_body(db);
         validator.diagnostics
     }

crates/hir_ty/src/infer/expr.rs

@@ -367,7 +367,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
             Expr::Path(p) => {
                 // FIXME this could be more efficient...
                 let resolver = resolver_for_expr(self.db.upcast(), self.owner, tgt_expr);
-                self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or(self.err_ty())
+                self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or_else(|| self.err_ty())
             }
             Expr::Continue { .. } => TyKind::Never.intern(&Interner),
             Expr::Break { expr, label } => {
@@ -511,7 +511,7 @@ fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
                         _ => None,
                     }
                 })
-                .unwrap_or(self.err_ty());
+                .unwrap_or_else(|| self.err_ty());
                 let ty = self.insert_type_vars(ty);
                 self.normalize_associated_types_in(ty)
             }
@@ -818,8 +818,10 @@ fn infer_block(
         for stmt in statements {
             match stmt {
                 Statement::Let { pat, type_ref, initializer } => {
-                    let decl_ty =
-                        type_ref.as_ref().map(|tr| self.make_ty(tr)).unwrap_or(self.err_ty());
+                    let decl_ty = type_ref
+                        .as_ref()
+                        .map(|tr| self.make_ty(tr))
+                        .unwrap_or_else(|| self.err_ty());
 
                     // Always use the declared type when specified
                     let mut ty = decl_ty.clone();

crates/hir_ty/src/infer/pat.rs

@@ -192,7 +192,7 @@ pub(super) fn infer_pat(
             Pat::Path(path) => {
                 // FIXME use correct resolver for the surrounding expression
                 let resolver = self.resolver.clone();
-                self.infer_path(&resolver, path, pat.into()).unwrap_or(self.err_ty())
+                self.infer_path(&resolver, path, pat.into()).unwrap_or_else(|| self.err_ty())
             }
             Pat::Bind { mode, name: _, subpat } => {
                 let mode = if mode == &BindingAnnotation::Unannotated {

crates/hir_ty/src/lower.rs

@@ -562,7 +562,7 @@ fn select_associated_type(&self, res: Option<TypeNs>, segment: PathSegment<'_>)
                 },
             );
 
-            ty.unwrap_or(TyKind::Error.intern(&Interner))
+            ty.unwrap_or_else(|| TyKind::Error.intern(&Interner))
         } else {
             TyKind::Error.intern(&Interner)
         }

crates/ide/src/goto_type_definition.rs

@@ -25,7 +25,7 @@ pub(crate) fn goto_type_definition(
     let token: SyntaxToken = pick_best(file.syntax().token_at_offset(position.offset))?;
     let token: SyntaxToken = sema.descend_into_macros(token);
 
-    let (ty, node) = sema.token_ancestors_with_macros(token.clone()).find_map(|node| {
+    let (ty, node) = sema.token_ancestors_with_macros(token).find_map(|node| {
         let ty = match_ast! {
             match node {
                 ast::Expr(it) => sema.type_of_expr(&it)?,

crates/ide_assists/src/handlers/remove_dbg.rs

@@ -35,14 +35,14 @@ pub(crate) fn remove_dbg(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
                             .prev_sibling_or_token()
                             .and_then(whitespace_start)
                             .map(|start| TextRange::new(start, macro_call.syntax().text_range().end()))
-                            .unwrap_or(macro_call.syntax().text_range())
+                            .unwrap_or_else(|| macro_call.syntax().text_range())
                     },
                     ast::ExprStmt(it) => {
                         let start = it
                             .syntax()
                             .prev_sibling_or_token()
                             .and_then(whitespace_start)
-                            .unwrap_or(it.syntax().text_range().start());
+                            .unwrap_or_else(|| it.syntax().text_range().start());
                         let end = it.syntax().text_range().end();
 
                         TextRange::new(start, end)

crates/proc_macro_api/src/version.rs

@@ -28,23 +28,23 @@ macro_rules! err {
 
     let ver_str = read_version(dylib_path)?;
     let mut items = ver_str.split_whitespace();
-    let tag = items.next().ok_or(err!("version format error"))?;
+    let tag = items.next().ok_or_else(|| err!("version format error"))?;
     if tag != "rustc" {
         return Err(err!("version format error (No rustc tag)"));
     }
 
-    let version_part = items.next().ok_or(err!("no version string"))?;
+    let version_part = items.next().ok_or_else(|| err!("no version string"))?;
     let mut version_parts = version_part.split('-');
-    let version = version_parts.next().ok_or(err!("no version"))?;
+    let version = version_parts.next().ok_or_else(|| err!("no version"))?;
     let channel = version_parts.next().unwrap_or_default().to_string();
 
-    let commit = items.next().ok_or(err!("no commit info"))?;
+    let commit = items.next().ok_or_else(|| err!("no commit info"))?;
     // remove (
     if commit.len() == 0 {
         return Err(err!("commit format error"));
     }
     let commit = commit[1..].to_string();
-    let date = items.next().ok_or(err!("no date info"))?;
+    let date = items.next().ok_or_else(|| err!("no date info"))?;
     // remove )
     if date.len() == 0 {
         return Err(err!("date format error"));

crates/project_model/src/build_data.rs

@@ -187,7 +187,7 @@ fn collect(
                 let mut deserializer = serde_json::Deserializer::from_str(line);
                 deserializer.disable_recursion_limit();
                 let message = Message::deserialize(&mut deserializer)
-                    .unwrap_or(Message::TextLine(line.to_string()));
+                    .unwrap_or_else(|_| Message::TextLine(line.to_string()));
 
                 match message {
                     Message::BuildScriptExecuted(BuildScript {

crates/test_utils/src/fixture.rs

@@ -131,7 +131,7 @@ pub fn parse(ra_fixture: &str) -> (Option<MiniCore>, Vec<Fixture>) {
                 res.push(meta)
             } else {
                 if line.starts_with("// ")
-                    && line.contains(":")
+                    && line.contains(':')
                     && !line.contains("::")
                     && line.chars().all(|it| !it.is_uppercase())
                 {