From 5e26508744850e9c541e83d27f710cf221360fbc Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Wed, 16 Mar 2016 05:47:18 -0400
Subject: [PATCH] refactor DefPathData variants

In particular, remove the name from the Impl, since that name is
synthesized and is not predictable (it tends to break incr. comp.).

Also rename the variants to be a bit more uniform and remove some
distinctions that we were not really taking advantage of anywhere.
---
 src/librustc/front/map/collector.rs   | 25 +++++++++++++++----------
 src/librustc/front/map/definitions.rs | 22 +++++++++-------------
 2 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/src/librustc/front/map/collector.rs b/src/librustc/front/map/collector.rs
index 7f66b56b2d3..4ae03b1b9d7 100644
--- a/src/librustc/front/map/collector.rs
+++ b/src/librustc/front/map/collector.rs
@@ -133,11 +133,16 @@ fn visit_item(&mut self, i: &'ast Item) {
         // Pick the def data. This need not be unique, but the more
         // information we encapsulate into
         let def_data = match i.node {
-            ItemDefaultImpl(..) | ItemImpl(..) => DefPathData::Impl(i.name),
-            ItemEnum(..) | ItemStruct(..) | ItemTrait(..) => DefPathData::Type(i.name),
-            ItemExternCrate(..) | ItemMod(..) => DefPathData::Mod(i.name),
-            ItemStatic(..) | ItemConst(..) | ItemFn(..) => DefPathData::Value(i.name),
-            _ => DefPathData::Misc,
+            ItemDefaultImpl(..) | ItemImpl(..) =>
+                DefPathData::Impl,
+            ItemEnum(..) | ItemStruct(..) | ItemTrait(..) |
+            ItemExternCrate(..) | ItemMod(..) | ItemForeignMod(..) |
+            ItemTy(..) =>
+                DefPathData::TypeNs(i.name),
+            ItemStatic(..) | ItemConst(..) | ItemFn(..) =>
+                DefPathData::ValueNs(i.name),
+            ItemUse(..) =>
+                DefPathData::Misc,
         };
 
         self.insert_def(i.id, NodeItem(i), def_data);
@@ -202,7 +207,7 @@ fn visit_item(&mut self, i: &'ast Item) {
     fn visit_foreign_item(&mut self, foreign_item: &'ast ForeignItem) {
         self.insert_def(foreign_item.id,
                         NodeForeignItem(foreign_item),
-                        DefPathData::Value(foreign_item.name));
+                        DefPathData::ValueNs(foreign_item.name));
 
         let parent_node = self.parent_node;
         self.parent_node = foreign_item.id;
@@ -222,8 +227,8 @@ fn visit_generics(&mut self, generics: &'ast Generics) {
 
     fn visit_trait_item(&mut self, ti: &'ast TraitItem) {
         let def_data = match ti.node {
-            MethodTraitItem(..) | ConstTraitItem(..) => DefPathData::Value(ti.name),
-            TypeTraitItem(..) => DefPathData::Type(ti.name),
+            MethodTraitItem(..) | ConstTraitItem(..) => DefPathData::ValueNs(ti.name),
+            TypeTraitItem(..) => DefPathData::TypeNs(ti.name),
         };
 
         self.insert(ti.id, NodeTraitItem(ti));
@@ -246,8 +251,8 @@ fn visit_trait_item(&mut self, ti: &'ast TraitItem) {
 
     fn visit_impl_item(&mut self, ii: &'ast ImplItem) {
         let def_data = match ii.node {
-            ImplItemKind::Method(..) | ImplItemKind::Const(..) => DefPathData::Value(ii.name),
-            ImplItemKind::Type(..) => DefPathData::Type(ii.name),
+            ImplItemKind::Method(..) | ImplItemKind::Const(..) => DefPathData::ValueNs(ii.name),
+            ImplItemKind::Type(..) => DefPathData::TypeNs(ii.name),
         };
 
         self.insert_def(ii.id, NodeImplItem(ii), def_data);
diff --git a/src/librustc/front/map/definitions.rs b/src/librustc/front/map/definitions.rs
index 4d5da12cad2..82574b85229 100644
--- a/src/librustc/front/map/definitions.rs
+++ b/src/librustc/front/map/definitions.rs
@@ -144,10 +144,9 @@ pub enum DefPathData {
     Misc,
 
     // Different kinds of items and item-like things:
-    Impl(ast::Name),
-    Type(ast::Name),
-    Mod(ast::Name),
-    Value(ast::Name),
+    Impl,
+    TypeNs(ast::Name), // something in the type NS
+    ValueNs(ast::Name), // something in the value NS
     MacroDef(ast::Name),
     ClosureExpr,
 
@@ -159,10 +158,6 @@ pub enum DefPathData {
     StructCtor, // implicit ctor for a tuple-like struct
     Initializer, // initializer for a const
     Binding(ast::Name), // pattern binding
-
-    // An external crate that does not have an `extern crate` in this
-    // crate.
-    DetachedCrate(ast::Name),
 }
 
 impl Definitions {
@@ -247,20 +242,21 @@ impl DefPathData {
     pub fn as_interned_str(&self) -> InternedString {
         use self::DefPathData::*;
         match *self {
-            Impl(name) |
-            Type(name) |
-            Mod(name) |
-            Value(name) |
+            TypeNs(name) |
+            ValueNs(name) |
             MacroDef(name) |
             TypeParam(name) |
             LifetimeDef(name) |
             EnumVariant(name) |
-            DetachedCrate(name) |
             Binding(name) |
             Field(name) => {
                 name.as_str()
             }
 
+            Impl => {
+                InternedString::new("{{impl}}")
+            }
+
             // note that this does not show up in user printouts
             CrateRoot => {
                 InternedString::new("{{root}}")
-- 
2.44.0