resolve: improve/remove allocations

[rust.git] / src / librustc_resolve / macros.rs

diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs
index c31b558dedea03452bebb1a0010ec62f01465332..28284a45bcdd5f03098cf665c25e79013840cb28 100644 (file)
--- a/src/librustc_resolve/macros.rs
+++ b/src/librustc_resolve/macros.rs
@@ -203,9 +203,7 @@ fn visit_ast_fragment_with_placeholders(&mut self, mark: Mark, fragment: &AstFra
         self.current_module = invocation.module.get();
         self.current_module.unresolved_invocations.borrow_mut().remove(&mark);
         self.current_module.unresolved_invocations.borrow_mut().extend(derives);
-        for &derive in derives {
-            self.invocations.insert(derive, invocation);
-        }
+        self.invocations.extend(derives.iter().map(|&derive| (derive, invocation)));
         let mut visitor = BuildReducedGraphVisitor {
             resolver: self,
             current_legacy_scope: invocation.parent_legacy_scope.get(),
@@ -277,11 +275,12 @@ fn find_legacy_attr_invoc(&mut self, attrs: &mut Vec<ast::Attribute>, allow_deri
                     if traits.is_empty() {
                         attrs.remove(i);
                     } else {
-                        let mut tokens = Vec::new();
+                        let mut tokens = Vec::with_capacity(traits.len() - 1);
                         for (j, path) in traits.iter().enumerate() {
                             if j > 0 {
                                 tokens.push(TokenTree::Token(attrs[i].span, Token::Comma).into());
                             }
+                            tokens.reserve((path.segments.len() * 2).saturating_sub(1));
                             for (k, segment) in path.segments.iter().enumerate() {
                                 if k > 0 {
                                     tokens.push(TokenTree::Token(path.span, Token::ModSep).into());
@@ -692,7 +691,7 @@ struct Flags: u8 {
                     }
                 }
                 WhereToResolve::ExternPrelude => {
-                    if use_prelude && self.session.extern_prelude.contains(&ident.name) {
+                    if use_prelude && self.extern_prelude.contains(&ident.name) {
                         let crate_id =
                             self.crate_loader.process_path_extern(ident.name, ident.span);
                         let crate_root =