3 files changed, 45 insertions, 39 deletions

diff --git a/crates/ra_hir/src/lang_item.rs b/crates/ra_hir/src/lang_item.rs
index 89fd85f59..55f0c3a13 100644
--- a/crates/ra_hir/src/lang_item.rs
+++ b/crates/ra_hir/src/lang_item.rs
@@ -1,13 +1,14 @@
 //! FIXME: write short doc here
 
-use rustc_hash::FxHashMap;
 use std::sync::Arc;
 
-use ra_syntax::{ast::AttrsOwner, SmolStr};
+use hir_def::{AdtId, AttrDefId, ModuleDefId};
+use ra_syntax::SmolStr;
+use rustc_hash::FxHashMap;
 
 use crate::{
     db::{AstDatabase, DefDatabase, HirDatabase},
-    Adt, Crate, Enum, Function, HasSource, ImplBlock, Module, ModuleDef, Static, Struct, Trait,
+    Crate, Enum, Function, ImplBlock, Module, Static, Struct, Trait,
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -95,26 +96,27 @@ impl LangItems {
 
     fn collect_lang_items(&mut self, db: &(impl DefDatabase + AstDatabase), module: Module) {
         // Look for impl targets
-        for impl_block in module.impl_blocks(db) {
-            let src = impl_block.source(db);
-            if let Some(lang_item_name) = lang_item_name(&src.value) {
-                self.items
-                    .entry(lang_item_name)
-                    .or_insert_with(|| LangItemTarget::ImplBlock(impl_block));
-            }
+        let def_map = db.crate_def_map(module.id.krate);
+        let module_data = &def_map[module.id.module_id];
+        for &impl_block in module_data.impls.iter() {
+            self.collect_lang_item(db, impl_block, LangItemTarget::ImplBlock)
         }
 
-        for def in module.declarations(db) {
+        for def in module_data.scope.declarations() {
             match def {
-                ModuleDef::Trait(trait_) => {
+                ModuleDefId::TraitId(trait_) => {
                     self.collect_lang_item(db, trait_, LangItemTarget::Trait)
                 }
-                ModuleDef::Adt(Adt::Enum(e)) => self.collect_lang_item(db, e, LangItemTarget::Enum),
-                ModuleDef::Adt(Adt::Struct(s)) => {
+                ModuleDefId::AdtId(AdtId::EnumId(e)) => {
+                    self.collect_lang_item(db, e, LangItemTarget::Enum)
+                }
+                ModuleDefId::AdtId(AdtId::StructId(s)) => {
                     self.collect_lang_item(db, s, LangItemTarget::Struct)
                 }
-                ModuleDef::Function(f) => self.collect_lang_item(db, f, LangItemTarget::Function),
-                ModuleDef::Static(s) => self.collect_lang_item(db, s, LangItemTarget::Static),
+                ModuleDefId::FunctionId(f) => {
+                    self.collect_lang_item(db, f, LangItemTarget::Function)
+                }
+                ModuleDefId::StaticId(s) => self.collect_lang_item(db, s, LangItemTarget::Static),
                 _ => {}
             }
         }
@@ -135,26 +137,18 @@ impl LangItems {
         }
     }
 
-    fn collect_lang_item<T, N>(
+    fn collect_lang_item<T, D>(
         &mut self,
         db: &(impl DefDatabase + AstDatabase),
         item: T,
-        constructor: fn(T) -> LangItemTarget,
+        constructor: fn(D) -> LangItemTarget,
     ) where
-        T: Copy + HasSource<Ast = N>,
-        N: AttrsOwner,
+        T: Into<AttrDefId> + Copy,
+        D: From<T>,
     {
-        let node = item.source(db).value;
-        if let Some(lang_item_name) = lang_item_name(&node) {
-            self.items.entry(lang_item_name).or_insert_with(|| constructor(item));
+        let attrs = db.attrs(item.into());
+        if let Some(lang_item_name) = attrs.find_string_value("lang") {
+            self.items.entry(lang_item_name).or_insert_with(|| constructor(D::from(item)));
         }
     }
 }
-
-fn lang_item_name<T: AttrsOwner>(node: &T) -> Option<SmolStr> {
-    node.attrs()
-        .filter_map(|a| a.as_simple_key_value())
-        .filter(|(key, _)| key == "lang")
-        .map(|(_, val)| val)
-        .nth(0)
-}
diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index ce397f6b0..eee5e44bf 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -53,28 +53,38 @@ impl Attrs {
                     }
                 }
             }
-            AttrDefId::AdtId(it) => match it {
-                AdtId::StructId(it) => attrs_from_ast(it.0.lookup_intern(db).ast_id, db),
-                AdtId::EnumId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
-                AdtId::UnionId(it) => attrs_from_ast(it.0.lookup_intern(db).ast_id, db),
-            },
             AttrDefId::EnumVariantId(it) => {
                 let src = it.parent.child_source(db);
                 let hygiene = Hygiene::new(db, src.file_id);
                 Attr::from_attrs_owner(&src.value[it.local_id], &hygiene)
             }
+            AttrDefId::AdtId(it) => match it {
+                AdtId::StructId(it) => attrs_from_ast(it.0.lookup_intern(db).ast_id, db),
+                AdtId::EnumId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
+                AdtId::UnionId(it) => attrs_from_ast(it.0.lookup_intern(db).ast_id, db),
+            },
             AttrDefId::StaticId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
+            AttrDefId::TraitId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
+            AttrDefId::MacroDefId(it) => attrs_from_ast(it.ast_id, db),
+            AttrDefId::ImplId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
             AttrDefId::ConstId(it) => attrs_from_loc(it.lookup(db), db),
             AttrDefId::FunctionId(it) => attrs_from_loc(it.lookup(db), db),
-            AttrDefId::TraitId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
             AttrDefId::TypeAliasId(it) => attrs_from_loc(it.lookup(db), db),
-            AttrDefId::MacroDefId(it) => attrs_from_ast(it.ast_id, db),
         }
     }
 
     pub fn has_atom(&self, atom: &str) -> bool {
         self.iter().any(|it| it.is_simple_atom(atom))
     }
+
+    pub fn find_string_value(&self, key: &str) -> Option<SmolStr> {
+        self.iter().filter(|attr| attr.is_simple_atom(key)).find_map(|attr| {
+            match attr.input.as_ref()? {
+                AttrInput::Literal(it) => Some(it.clone()),
+                _ => None,
+            }
+        })
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index 1bcdf9b78..20d4deadb 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -489,6 +489,7 @@ pub enum AttrDefId {
     TraitId(TraitId),
     TypeAliasId(TypeAliasId),
     MacroDefId(MacroDefId),
+    ImplId(ImplId),
 }
 
 impl_froms!(
@@ -501,7 +502,8 @@ impl_froms!(
     FunctionId,
     TraitId,
     TypeAliasId,
-    MacroDefId
+    MacroDefId,
+    ImplId
 );
 
 trait Intern {