hash the contents of impl-item-ref by adding them to visitor

Also simplify some of the `ty::AssociatedItem` representation,
in particular by folding `has_value` into `hir::Defaultness`

3 files changed, 18 insertions, 21 deletions

diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs
index ba85544326f..6dbcfc8523d 100644
--- a/src/librustc_metadata/decoder.rs
+++ b/src/librustc_metadata/decoder.rs
@@ -834,7 +834,6 @@ impl<'a, 'tcx> CrateMetadata {
                     kind: ty::AssociatedKind::Const,
                     vis: item.visibility,
                     defaultness: container.defaultness(),
-                    has_value: container.has_value(),
                     def_id: self.local_def_id(id),
                     container: container.with_def_id(parent),
                     method_has_self_argument: false
@@ -848,7 +847,6 @@ impl<'a, 'tcx> CrateMetadata {
                     kind: ty::AssociatedKind::Method,
                     vis: item.visibility,
                     defaultness: data.container.defaultness(),
-                    has_value: data.container.has_value(),
                     def_id: self.local_def_id(id),
                     container: data.container.with_def_id(parent),
                     method_has_self_argument: data.has_self
@@ -861,7 +859,6 @@ impl<'a, 'tcx> CrateMetadata {
                     kind: ty::AssociatedKind::Type,
                     vis: item.visibility,
                     defaultness: container.defaultness(),
-                    has_value: container.has_value(),
                     def_id: self.local_def_id(id),
                     container: container.with_def_id(parent),
                     method_has_self_argument: false
diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs
index 2d96eeb8f20..d1508d7e9b3 100644
--- a/src/librustc_metadata/encoder.rs
+++ b/src/librustc_metadata/encoder.rs
@@ -460,10 +460,13 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let ast_item = tcx.map.expect_trait_item(node_id);
         let trait_item = tcx.associated_item(def_id);
 
-        let container = if trait_item.has_value {
-            AssociatedContainer::TraitWithDefault
-        } else {
-            AssociatedContainer::TraitRequired
+        let container = match trait_item.defaultness {
+            hir::Defaultness::Default { has_value: true } =>
+                AssociatedContainer::TraitWithDefault,
+            hir::Defaultness::Default { has_value: false } =>
+                AssociatedContainer::TraitRequired,
+            hir::Defaultness::Final =>
+                span_bug!(ast_item.span, "traits cannot have final items"),
         };
 
         let kind = match trait_item.kind {
@@ -501,7 +504,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                     Some(self.encode_item_type(def_id))
                 }
                 ty::AssociatedKind::Type => {
-                    if trait_item.has_value {
+                    if trait_item.defaultness.has_value() {
                         Some(self.encode_item_type(def_id))
                     } else {
                         None
@@ -530,8 +533,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let impl_def_id = impl_item.container.id();
 
         let container = match impl_item.defaultness {
-            hir::Defaultness::Default => AssociatedContainer::ImplDefault,
+            hir::Defaultness::Default { has_value: true } => AssociatedContainer::ImplDefault,
             hir::Defaultness::Final => AssociatedContainer::ImplFinal,
+            hir::Defaultness::Default { has_value: false } =>
+                span_bug!(ast_item.span, "impl items always have values (currently)"),
         };
 
         let kind = match impl_item.kind {
diff --git a/src/librustc_metadata/schema.rs b/src/librustc_metadata/schema.rs
index d7a5f7ad715..7553b2e05a7 100644
--- a/src/librustc_metadata/schema.rs
+++ b/src/librustc_metadata/schema.rs
@@ -310,21 +310,16 @@ impl AssociatedContainer {
         }
     }
 
-    pub fn has_value(&self) -> bool {
-        match *self {
-            AssociatedContainer::TraitRequired => false,
-
-            AssociatedContainer::TraitWithDefault |
-            AssociatedContainer::ImplDefault |
-            AssociatedContainer::ImplFinal => true,
-        }
-    }
-
     pub fn defaultness(&self) -> hir::Defaultness {
         match *self {
-            AssociatedContainer::TraitRequired |
+            AssociatedContainer::TraitRequired => hir::Defaultness::Default {
+                has_value: false,
+            },
+
             AssociatedContainer::TraitWithDefault |
-            AssociatedContainer::ImplDefault => hir::Defaultness::Default,
+            AssociatedContainer::ImplDefault => hir::Defaultness::Default {
+                has_value: true,
+            },
 
             AssociatedContainer::ImplFinal => hir::Defaultness::Final,
         }