Refactor `CrateConfig`.

3 files changed, 6 insertions, 44 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 8de843fdcb8..3664cc8e064 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -25,6 +25,7 @@ use print::pprust;
 use ptr::P;
 use tokenstream::{TokenTree};
 
+use std::collections::HashSet;
 use std::fmt;
 use std::rc::Rc;
 use std::u32;
@@ -485,7 +486,7 @@ pub struct WhereEqPredicate {
 
 /// The set of MetaItems that define the compilation environment of the crate,
 /// used to drive conditional compilation
-pub type CrateConfig = Vec<P<MetaItem>>;
+pub type CrateConfig = HashSet<(Name, Option<InternedString>)>;
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct Crate {
@@ -519,7 +520,7 @@ pub type MetaItem = Spanned<MetaItemKind>;
 /// A compile-time attribute item.
 ///
 /// E.g. `#[test]`, `#[derive(..)]` or `#[feature = "foo"]`
-#[derive(Clone, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum MetaItemKind {
     /// Word meta item.
     ///
@@ -535,34 +536,6 @@ pub enum MetaItemKind {
     NameValue(Name, Lit),
 }
 
-// can't be derived because the MetaItemKind::List requires an unordered comparison
-impl PartialEq for MetaItemKind {
-    fn eq(&self, other: &MetaItemKind) -> bool {
-        use self::MetaItemKind::*;
-        match *self {
-            Word(ref ns) => match *other {
-                Word(ref no) => (*ns) == (*no),
-                _ => false
-            },
-            List(ref ns, ref miss) => match *other {
-                List(ref no, ref miso) => {
-                    ns == no &&
-                        miss.iter().all(|mi| {
-                            miso.iter().any(|x| x.node == mi.node)
-                        })
-                }
-                _ => false
-            },
-            NameValue(ref ns, ref vs) => match *other {
-                NameValue(ref no, ref vo) => {
-                    (*ns) == (*no) && vs.node == vo.node
-                }
-                _ => false
-            },
-        }
-    }
-}
-
 /// A Block (`{ .. }`).
 ///
 /// E.g. `{ .. }` as in `fn foo() { .. }`
diff --git a/src/libsyntax/attr.rs b/src/libsyntax/attr.rs
index 220ecf52ae0..f84199fb29e 100644
--- a/src/libsyntax/attr.rs
+++ b/src/libsyntax/attr.rs
@@ -400,18 +400,6 @@ pub fn mk_sugared_doc_attr(id: AttrId, text: InternedString, lo: BytePos, hi: By
     }
 }
 
-/* Searching */
-/// Check if `needle` occurs in `haystack` by a structural
-/// comparison. This is slightly subtle, and relies on ignoring the
-/// span included in the `==` comparison a plain MetaItem.
-pub fn contains(haystack: &[P<MetaItem>], needle: &MetaItem) -> bool {
-    debug!("attr::contains (name={})", needle.name());
-    haystack.iter().any(|item| {
-        debug!("  testing: {}", item.name());
-        item.node == needle.node
-    })
-}
-
 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
     debug!("attr::list_contains_name (name={})", name);
     items.iter().any(|item| {
@@ -558,7 +546,7 @@ pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Feat
             if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
                 gated_cfg.check_and_emit(sess, feats);
             }
-            contains(&sess.config, cfg)
+            sess.config.contains(&(cfg.name(), cfg.value_str()))
         }
     }
 }
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 12408c7d3c9..7feb745259c 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -22,6 +22,7 @@ use str::char_at;
 use tokenstream;
 
 use std::cell::RefCell;
+use std::collections::HashSet;
 use std::iter;
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
@@ -64,7 +65,7 @@ impl ParseSess {
         ParseSess {
             span_diagnostic: handler,
             unstable_features: UnstableFeatures::from_environment(),
-            config: Vec::new(),
+            config: HashSet::new(),
             included_mod_stack: RefCell::new(vec![]),
             code_map: code_map
         }