New upstream version 1.36.0+dfsg1

[rustc.git] / src / librustc / middle / lib_features.rs

diff --git a/src/librustc/middle/lib_features.rs b/src/librustc/middle/lib_features.rs
index ee8dd9e58b5ff9b2babee032a9575bfad06aeac1..76934ddd69b1bb7d9efab259f58e669fba61a630 100644 (file)
--- a/src/librustc/middle/lib_features.rs
+++ b/src/librustc/middle/lib_features.rs
@@ -8,7 +8,7 @@ use crate::ty::TyCtxt;
 use crate::hir::intravisit::{self, NestedVisitorMap, Visitor};
 use syntax::symbol::Symbol;
 use syntax::ast::{Attribute, MetaItem, MetaItemKind};
-use syntax_pos::Span;
+use syntax_pos::{Span, sym};
 use rustc_data_structures::fx::{FxHashSet, FxHashMap};
 use rustc_macros::HashStable;
 use errors::DiagnosticId;
@@ -51,12 +51,12 @@ impl<'a, 'tcx> LibFeatureCollector<'a, 'tcx> {
     }
 
     fn extract(&self, attr: &Attribute) -> Option<(Symbol, Option<Symbol>, Span)> {
-        let stab_attrs = vec!["stable", "unstable", "rustc_const_unstable"];
+        let stab_attrs = [sym::stable, sym::unstable, sym::rustc_const_unstable];
 
         // Find a stability attribute (i.e., `#[stable (..)]`, `#[unstable (..)]`,
         // `#[rustc_const_unstable (..)]`).
         if let Some(stab_attr) = stab_attrs.iter().find(|stab_attr| {
-            attr.check_name(stab_attr)
+            attr.check_name(**stab_attr)
         }) {
             let meta_item = attr.meta();
             if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta_item {
@@ -65,9 +65,9 @@ impl<'a, 'tcx> LibFeatureCollector<'a, 'tcx> {
                 for meta in metas {
                     if let Some(mi) = meta.meta_item() {
                         // Find the `feature = ".."` meta-item.
-                        match (mi.name_or_empty().get(), mi.value_str()) {
-                            ("feature", val) => feature = val,
-                            ("since", val) => since = val,
+                        match (mi.name_or_empty(), mi.value_str()) {
+                            (sym::feature, val) => feature = val,
+                            (sym::since, val) => since = val,
                             _ => {}
                         }
                     }
@@ -76,7 +76,7 @@ impl<'a, 'tcx> LibFeatureCollector<'a, 'tcx> {
                     // This additional check for stability is to make sure we
                     // don't emit additional, irrelevant errors for malformed
                     // attributes.
-                    if *stab_attr != "stable" || since.is_some() {
+                    if *stab_attr != sym::stable || since.is_some() {
                         return Some((feature, since, attr.span));
                     }
                 }