Abstract over ItemTreeLoc

crates/hir-def/src/attr.rs

@@ -24,12 +24,11 @@ use triomphe::Arc;
 
 use crate::{
     db::DefDatabase,
-    item_tree::{AttrOwner, Fields, ItemTreeId, ItemTreeModItemNode},
+    item_tree::{AttrOwner, Fields, ItemTreeNode},
     lang_item::LangItem,
     nameres::{ModuleOrigin, ModuleSource},
     src::{HasChildSource, HasSource},
-    AdtId, AssocItemLoc, AttrDefId, GenericParamId, ItemLoc, LocalFieldId, Lookup, MacroId,
+    AdtId, AttrDefId, GenericParamId, ItemTreeLoc, LocalFieldId, Lookup, MacroId, VariantId,
-    VariantId,
 };
 
 /// Desugared attributes of an item post `cfg_attr` expansion.
@@ -356,11 +355,7 @@ impl AttrsWithOwner {
             AttrDefId::FieldId(it) => {
                 return db.fields_attrs(it.parent)[it.local_id].clone();
             }
-            AttrDefId::EnumVariantId(it) => {
+            AttrDefId::EnumVariantId(it) => attrs_from_item_tree_loc(db, it),
-                let id = it.lookup(db).id;
-                let tree = id.item_tree(db);
-                tree.raw_attrs(id.value.into()).clone()
-            }
             AttrDefId::AdtId(it) => match it {
                 AdtId::StructId(it) => attrs_from_item_tree_loc(db, it),
                 AdtId::EnumId(it) => attrs_from_item_tree_loc(db, it),
@@ -369,15 +364,15 @@ impl AttrsWithOwner {
             AttrDefId::TraitId(it) => attrs_from_item_tree_loc(db, it),
             AttrDefId::TraitAliasId(it) => attrs_from_item_tree_loc(db, it),
             AttrDefId::MacroId(it) => match it {
-                MacroId::Macro2Id(it) => attrs_from_item_tree(db, it.lookup(db).id),
+                MacroId::Macro2Id(it) => attrs_from_item_tree_loc(db, it),
-                MacroId::MacroRulesId(it) => attrs_from_item_tree(db, it.lookup(db).id),
+                MacroId::MacroRulesId(it) => attrs_from_item_tree_loc(db, it),
-                MacroId::ProcMacroId(it) => attrs_from_item_tree(db, it.lookup(db).id),
+                MacroId::ProcMacroId(it) => attrs_from_item_tree_loc(db, it),
             },
             AttrDefId::ImplId(it) => attrs_from_item_tree_loc(db, it),
-            AttrDefId::ConstId(it) => attrs_from_item_tree_assoc(db, it),
+            AttrDefId::ConstId(it) => attrs_from_item_tree_loc(db, it),
-            AttrDefId::StaticId(it) => attrs_from_item_tree_assoc(db, it),
+            AttrDefId::StaticId(it) => attrs_from_item_tree_loc(db, it),
-            AttrDefId::FunctionId(it) => attrs_from_item_tree_assoc(db, it),
+            AttrDefId::FunctionId(it) => attrs_from_item_tree_loc(db, it),
-            AttrDefId::TypeAliasId(it) => attrs_from_item_tree_assoc(db, it),
+            AttrDefId::TypeAliasId(it) => attrs_from_item_tree_loc(db, it),
             AttrDefId::GenericParamId(it) => match it {
                 GenericParamId::ConstParamId(it) => {
                     let src = it.parent().child_source(db);
@@ -602,29 +597,14 @@ fn any_has_attrs<'db>(
     id.lookup(db).source(db).map(ast::AnyHasAttrs::new)
 }
 
-fn attrs_from_item_tree<N: ItemTreeModItemNode>(
+fn attrs_from_item_tree_loc<'db, N: ItemTreeNode>(
-    db: &dyn DefDatabase,
+    db: &(dyn DefDatabase + 'db),
-    id: ItemTreeId<N>,
+    lookup: impl Lookup<Database<'db> = dyn DefDatabase + 'db, Data = impl ItemTreeLoc<Id = N>>,
 ) -> RawAttrs {
+    let id = lookup.lookup(db).item_tree_id();
     let tree = id.item_tree(db);
-    let mod_item = N::id_to_mod_item(id.value);
+    let attr_owner = N::attr_owner(id.value);
-    tree.raw_attrs(mod_item.into()).clone()
+    tree.raw_attrs(attr_owner).clone()
-}
-
-fn attrs_from_item_tree_loc<'db, N: ItemTreeModItemNode>(
-    db: &(dyn DefDatabase + 'db),
-    lookup: impl Lookup<Database<'db> = dyn DefDatabase + 'db, Data = ItemLoc<N>>,
-) -> RawAttrs {
-    let id = lookup.lookup(db).id;
-    attrs_from_item_tree(db, id)
-}
-
-fn attrs_from_item_tree_assoc<'db, N: ItemTreeModItemNode>(
-    db: &(dyn DefDatabase + 'db),
-    lookup: impl Lookup<Database<'db> = dyn DefDatabase + 'db, Data = AssocItemLoc<N>>,
-) -> RawAttrs {
-    let id = lookup.lookup(db).id;
-    attrs_from_item_tree(db, id)
 }
 
 pub(crate) fn fields_attrs_source_map(

crates/hir-def/src/child_by_source.rs

@@ -14,11 +14,11 @@ use crate::{
         DynMap,
     },
     item_scope::ItemScope,
-    item_tree::ItemTreeModItemNode,
+    item_tree::ItemTreeNode,
     nameres::DefMap,
     src::{HasChildSource, HasSource},
-    AdtId, AssocItemId, AssocItemLoc, DefWithBodyId, EnumId, FieldId, ImplId, ItemLoc, Lookup,
+    AdtId, AssocItemId, DefWithBodyId, EnumId, FieldId, ImplId, ItemTreeLoc, Lookup, MacroId,
-    MacroId, ModuleDefId, ModuleId, TraitId, VariantId,
+    ModuleDefId, ModuleId, TraitId, VariantId,
 };
 
 pub trait ChildBySource {
@@ -61,13 +61,9 @@ impl ChildBySource for ImplId {
 
 fn add_assoc_item(db: &dyn DefDatabase, res: &mut DynMap, file_id: HirFileId, item: AssocItemId) {
     match item {
-        AssocItemId::FunctionId(func) => {
+        AssocItemId::FunctionId(func) => insert_item_loc(db, res, file_id, func, keys::FUNCTION),
-            insert_assoc_item_loc(db, res, file_id, func, keys::FUNCTION)
+        AssocItemId::ConstId(konst) => insert_item_loc(db, res, file_id, konst, keys::CONST),
-        }
+        AssocItemId::TypeAliasId(ty) => insert_item_loc(db, res, file_id, ty, keys::TYPE_ALIAS),
-        AssocItemId::ConstId(konst) => insert_assoc_item_loc(db, res, file_id, konst, keys::CONST),
-        AssocItemId::TypeAliasId(ty) => {
-            insert_assoc_item_loc(db, res, file_id, ty, keys::TYPE_ALIAS)
-        }
     }
 }
 
@@ -87,7 +83,7 @@ impl ChildBySource for ItemScope {
             .for_each(|ext| insert_item_loc(db, res, file_id, ext, keys::EXTERN_CRATE));
         self.use_decls().for_each(|ext| insert_item_loc(db, res, file_id, ext, keys::USE));
         self.unnamed_consts(db)
-            .for_each(|konst| insert_assoc_item_loc(db, res, file_id, konst, keys::CONST));
+            .for_each(|konst| insert_item_loc(db, res, file_id, konst, keys::CONST));
         self.attr_macro_invocs().filter(|(id, _)| id.file_id == file_id).for_each(
             |(ast_id, call_id)| {
                 res[keys::ATTR_MACRO_CALL].insert(ast_id.to_node(db.upcast()), call_id);
@@ -132,17 +128,13 @@ impl ChildBySource for ItemScope {
             }
             match item {
                 ModuleDefId::FunctionId(id) => {
-                    insert_assoc_item_loc(db, map, file_id, id, keys::FUNCTION)
+                    insert_item_loc(db, map, file_id, id, keys::FUNCTION)
-                }
-                ModuleDefId::ConstId(id) => {
-                    insert_assoc_item_loc(db, map, file_id, id, keys::CONST)
                 }
+                ModuleDefId::ConstId(id) => insert_item_loc(db, map, file_id, id, keys::CONST),
                 ModuleDefId::TypeAliasId(id) => {
-                    insert_assoc_item_loc(db, map, file_id, id, keys::TYPE_ALIAS)
+                    insert_item_loc(db, map, file_id, id, keys::TYPE_ALIAS)
-                }
-                ModuleDefId::StaticId(id) => {
-                    insert_assoc_item_loc(db, map, file_id, id, keys::STATIC)
                 }
+                ModuleDefId::StaticId(id) => insert_item_loc(db, map, file_id, id, keys::STATIC),
                 ModuleDefId::TraitId(id) => insert_item_loc(db, map, file_id, id, keys::TRAIT),
                 ModuleDefId::TraitAliasId(id) => {
                     insert_item_loc(db, map, file_id, id, keys::TRAIT_ALIAS)
@@ -215,36 +207,20 @@ impl ChildBySource for DefWithBodyId {
     }
 }
 
-fn insert_item_loc<ID, N>(
+fn insert_item_loc<ID, N, Data>(
     db: &dyn DefDatabase,
     res: &mut DynMap,
     file_id: HirFileId,
     id: ID,
     key: Key<N::Source, ID>,
 ) where
-    ID: for<'db> Lookup<Database<'db> = dyn DefDatabase + 'db, Data = ItemLoc<N>> + 'static,
+    ID: for<'db> Lookup<Database<'db> = dyn DefDatabase + 'db, Data = Data> + 'static,
-    N: ItemTreeModItemNode,
+    Data: ItemTreeLoc<Id = N>,
+    N: ItemTreeNode,
     N::Source: 'static,
 {
     let loc = id.lookup(db);
-    if loc.id.file_id() == file_id {
+    if loc.item_tree_id().file_id() == file_id {
-        res[key].insert(loc.source(db).value, id)
-    }
-}
-
-fn insert_assoc_item_loc<ID, N>(
-    db: &dyn DefDatabase,
-    res: &mut DynMap,
-    file_id: HirFileId,
-    id: ID,
-    key: Key<N::Source, ID>,
-) where
-    ID: for<'db> Lookup<Database<'db> = dyn DefDatabase + 'db, Data = AssocItemLoc<N>> + 'static,
-    N: ItemTreeModItemNode,
-    N::Source: 'static,
-{
-    let loc = id.lookup(db);
-    if loc.id.file_id() == file_id {
         res[key].insert(loc.source(db).value, id)
     }
 }

crates/hir-def/src/generics.rs

@@ -21,13 +21,13 @@ use crate::{
     db::DefDatabase,
     dyn_map::{keys, DynMap},
     expander::Expander,
-    item_tree::{ItemTree, ItemTreeModItemNode},
+    item_tree::ItemTree,
     lower::LowerCtx,
     nameres::{DefMap, MacroSubNs},
     src::{HasChildSource, HasSource},
     type_ref::{ConstRef, LifetimeRef, TypeBound, TypeRef},
-    AdtId, AssocItemLoc, ConstParamId, GenericDefId, HasModule, ItemLoc, LifetimeParamId,
+    AdtId, ConstParamId, GenericDefId, HasModule, LifetimeParamId, LocalLifetimeParamId,
-    LocalLifetimeParamId, LocalTypeOrConstParamId, Lookup, TypeOrConstParamId, TypeParamId,
+    LocalTypeOrConstParamId, Lookup, TypeOrConstParamId, TypeParamId,
 };
 
 /// Data about a generic type parameter (to a function, struct, impl, ...).

crates/hir-def/src/item_tree.rs

@@ -337,20 +337,15 @@ from_attrs!(
     LifetimeParamData(Idx<LifetimeParamData>),
 );
 
-/// Trait implemented by all item nodes in the item tree.
+/// Trait implemented by all nodes in the item tree.
-pub trait ItemTreeModItemNode: Clone {
+pub trait ItemTreeNode: Clone {
-    type Source: AstIdNode + Into<ast::Item>;
+    type Source: AstIdNode;
 
     fn ast_id(&self) -> FileAstId<Self::Source>;
 
     /// Looks up an instance of `Self` in an item tree.
     fn lookup(tree: &ItemTree, index: Idx<Self>) -> &Self;
-
+    fn attr_owner(id: FileItemTreeId<Self>) -> AttrOwner;
-    /// Downcasts a `ModItem` to a `FileItemTreeId` specific to this type.
-    fn id_from_mod_item(mod_item: ModItem) -> Option<FileItemTreeId<Self>>;
-
-    /// Upcasts a `FileItemTreeId` to a generic `ModItem`.
-    fn id_to_mod_item(id: FileItemTreeId<Self>) -> ModItem;
 }
 
 pub struct FileItemTreeId<N>(Idx<N>);
@@ -495,7 +490,7 @@ macro_rules! mod_items {
         )+
 
         $(
-            impl ItemTreeModItemNode for $typ {
+            impl ItemTreeNode for $typ {
                 type Source = $ast;
 
                 fn ast_id(&self) -> FileAstId<Self::Source> {
@@ -506,15 +501,8 @@ macro_rules! mod_items {
                     &tree.data().$fld[index]
                 }
 
-                fn id_from_mod_item(mod_item: ModItem) -> Option<FileItemTreeId<Self>> {
+                fn attr_owner(id: FileItemTreeId<Self>) -> AttrOwner {
-                    match mod_item {
+                    AttrOwner::ModItem(ModItem::$typ(id))
-                        ModItem::$typ(id) => Some(id),
-                        _ => None,
-                    }
-                }
-
-                fn id_to_mod_item(id: FileItemTreeId<Self>) -> ModItem {
-                    ModItem::$typ(id)
                 }
             }
 
@@ -578,17 +566,26 @@ impl Index<RawVisibilityId> for ItemTree {
     }
 }
 
-impl<N: ItemTreeModItemNode> Index<FileItemTreeId<N>> for ItemTree {
+impl<N: ItemTreeNode> Index<FileItemTreeId<N>> for ItemTree {
     type Output = N;
     fn index(&self, id: FileItemTreeId<N>) -> &N {
         N::lookup(self, id.index())
     }
 }
 
-impl Index<FileItemTreeId<Variant>> for ItemTree {
+impl ItemTreeNode for Variant {
-    type Output = Variant;
+    type Source = ast::Variant;
-    fn index(&self, id: FileItemTreeId<Variant>) -> &Variant {
+
-        &self[id.index()]
+    fn ast_id(&self) -> FileAstId<Self::Source> {
+        self.ast_id
+    }
+
+    fn lookup(tree: &ItemTree, index: Idx<Self>) -> &Self {
+        &tree.data().variants[index]
+    }
+
+    fn attr_owner(id: FileItemTreeId<Self>) -> AttrOwner {
+        AttrOwner::Variant(id)
     }
 }
 
@@ -1027,7 +1024,7 @@ impl AssocItem {
     }
 }
 
-#[derive(Debug, Eq, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Variant {
     pub name: Name,
     pub fields: Fields,

crates/hir-def/src/item_tree/lower.rs

@@ -13,7 +13,7 @@ use crate::{
 
 use super::*;
 
-fn id<N: ItemTreeModItemNode>(index: Idx<N>) -> FileItemTreeId<N> {
+fn id<N: ItemTreeNode>(index: Idx<N>) -> FileItemTreeId<N> {
     FileItemTreeId(index)
 }
 
@@ -267,7 +267,7 @@ impl<'a> Ctx<'a> {
             if let Some(data) = self.lower_variant(&variant) {
                 let idx = self.data().variants.alloc(data);
                 self.add_attrs(
-                    FileItemTreeId(idx).into(),
+                    id(idx).into(),
                     RawAttrs::new(self.db.upcast(), &variant, self.span_map()),
                 );
             }

crates/hir-def/src/lib.rs

@@ -98,8 +98,8 @@ use crate::{
     data::adt::VariantData,
     db::DefDatabase,
     item_tree::{
-        Const, Enum, ExternCrate, Function, Impl, ItemTreeId, ItemTreeModItemNode, Macro2,
+        Const, Enum, ExternCrate, Function, Impl, ItemTreeId, ItemTreeNode, Macro2, MacroRules,
-        MacroRules, Static, Struct, Trait, TraitAlias, TypeAlias, Union, Use, Variant,
+        Static, Struct, Trait, TraitAlias, TypeAlias, Union, Use, Variant,
     },
 };
 
@@ -212,28 +212,28 @@ impl ModuleId {
 pub type LocalModuleId = Idx<nameres::ModuleData>;
 
 #[derive(Debug)]
-pub struct ItemLoc<N: ItemTreeModItemNode> {
+pub struct ItemLoc<N: ItemTreeNode> {
     pub container: ModuleId,
     pub id: ItemTreeId<N>,
 }
 
-impl<N: ItemTreeModItemNode> Clone for ItemLoc<N> {
+impl<N: ItemTreeNode> Clone for ItemLoc<N> {
     fn clone(&self) -> Self {
         *self
     }
 }
 
-impl<N: ItemTreeModItemNode> Copy for ItemLoc<N> {}
+impl<N: ItemTreeNode> Copy for ItemLoc<N> {}
 
-impl<N: ItemTreeModItemNode> PartialEq for ItemLoc<N> {
+impl<N: ItemTreeNode> PartialEq for ItemLoc<N> {
     fn eq(&self, other: &Self) -> bool {
         self.container == other.container && self.id == other.id
     }
 }
 
-impl<N: ItemTreeModItemNode> Eq for ItemLoc<N> {}
+impl<N: ItemTreeNode> Eq for ItemLoc<N> {}
 
-impl<N: ItemTreeModItemNode> Hash for ItemLoc<N> {
+impl<N: ItemTreeNode> Hash for ItemLoc<N> {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.container.hash(state);
         self.id.hash(state);
@@ -241,34 +241,41 @@ impl<N: ItemTreeModItemNode> Hash for ItemLoc<N> {
 }
 
 #[derive(Debug)]
-pub struct AssocItemLoc<N: ItemTreeModItemNode> {
+pub struct AssocItemLoc<N: ItemTreeNode> {
     pub container: ItemContainerId,
     pub id: ItemTreeId<N>,
 }
 
-impl<N: ItemTreeModItemNode> Clone for AssocItemLoc<N> {
+impl<N: ItemTreeNode> Clone for AssocItemLoc<N> {
     fn clone(&self) -> Self {
         *self
     }
 }
 
-impl<N: ItemTreeModItemNode> Copy for AssocItemLoc<N> {}
+impl<N: ItemTreeNode> Copy for AssocItemLoc<N> {}
 
-impl<N: ItemTreeModItemNode> PartialEq for AssocItemLoc<N> {
+impl<N: ItemTreeNode> PartialEq for AssocItemLoc<N> {
     fn eq(&self, other: &Self) -> bool {
         self.container == other.container && self.id == other.id
     }
 }
 
-impl<N: ItemTreeModItemNode> Eq for AssocItemLoc<N> {}
+impl<N: ItemTreeNode> Eq for AssocItemLoc<N> {}
 
-impl<N: ItemTreeModItemNode> Hash for AssocItemLoc<N> {
+impl<N: ItemTreeNode> Hash for AssocItemLoc<N> {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.container.hash(state);
         self.id.hash(state);
     }
 }
 
+pub trait ItemTreeLoc {
+    type Container;
+    type Id;
+    fn item_tree_id(&self) -> ItemTreeId<Self::Id>;
+    fn container(&self) -> Self::Container;
+}
+
 macro_rules! impl_intern {
     ($id:ident, $loc:ident, $intern:ident, $lookup:ident) => {
         impl_intern_key!($id);
@@ -276,25 +283,44 @@ macro_rules! impl_intern {
     };
 }
 
+macro_rules! impl_loc {
+    ($loc:ident, $id:ident: $id_ty:ident, $container:ident: $container_type:ident) => {
+        impl ItemTreeLoc for $loc {
+            type Container = $container_type;
+            type Id = $id_ty;
+            fn item_tree_id(&self) -> ItemTreeId<Self::Id> {
+                self.$id
+            }
+            fn container(&self) -> Self::Container {
+                self.$container
+            }
+        }
+    };
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct FunctionId(salsa::InternId);
 type FunctionLoc = AssocItemLoc<Function>;
 impl_intern!(FunctionId, FunctionLoc, intern_function, lookup_intern_function);
+impl_loc!(FunctionLoc, id: Function, container: ItemContainerId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct StructId(salsa::InternId);
 type StructLoc = ItemLoc<Struct>;
 impl_intern!(StructId, StructLoc, intern_struct, lookup_intern_struct);
+impl_loc!(StructLoc, id: Struct, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct UnionId(salsa::InternId);
 pub type UnionLoc = ItemLoc<Union>;
 impl_intern!(UnionId, UnionLoc, intern_union, lookup_intern_union);
+impl_loc!(UnionLoc, id: Union, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct EnumId(salsa::InternId);
 pub type EnumLoc = ItemLoc<Enum>;
 impl_intern!(EnumId, EnumLoc, intern_enum, lookup_intern_enum);
+impl_loc!(EnumLoc, id: Enum, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct EnumVariantId(salsa::InternId);
@@ -306,6 +332,7 @@ pub struct EnumVariantLoc {
     pub index: u32,
 }
 impl_intern!(EnumVariantId, EnumVariantLoc, intern_enum_variant, lookup_intern_enum_variant);
+impl_loc!(EnumVariantLoc, id: Variant, parent: EnumId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct FieldId {
@@ -328,46 +355,55 @@ pub struct TupleFieldId {
 pub struct ConstId(salsa::InternId);
 type ConstLoc = AssocItemLoc<Const>;
 impl_intern!(ConstId, ConstLoc, intern_const, lookup_intern_const);
+impl_loc!(ConstLoc, id: Const, container: ItemContainerId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct StaticId(salsa::InternId);
 pub type StaticLoc = AssocItemLoc<Static>;
 impl_intern!(StaticId, StaticLoc, intern_static, lookup_intern_static);
+impl_loc!(StaticLoc, id: Static, container: ItemContainerId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TraitId(salsa::InternId);
 pub type TraitLoc = ItemLoc<Trait>;
 impl_intern!(TraitId, TraitLoc, intern_trait, lookup_intern_trait);
+impl_loc!(TraitLoc, id: Trait, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TraitAliasId(salsa::InternId);
 pub type TraitAliasLoc = ItemLoc<TraitAlias>;
 impl_intern!(TraitAliasId, TraitAliasLoc, intern_trait_alias, lookup_intern_trait_alias);
+impl_loc!(TraitAliasLoc, id: TraitAlias, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TypeAliasId(salsa::InternId);
 type TypeAliasLoc = AssocItemLoc<TypeAlias>;
 impl_intern!(TypeAliasId, TypeAliasLoc, intern_type_alias, lookup_intern_type_alias);
+impl_loc!(TypeAliasLoc, id: TypeAlias, container: ItemContainerId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct ImplId(salsa::InternId);
 type ImplLoc = ItemLoc<Impl>;
 impl_intern!(ImplId, ImplLoc, intern_impl, lookup_intern_impl);
+impl_loc!(ImplLoc, id: Impl, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct UseId(salsa::InternId);
 type UseLoc = ItemLoc<Use>;
 impl_intern!(UseId, UseLoc, intern_use, lookup_intern_use);
+impl_loc!(UseLoc, id: Use, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct ExternCrateId(salsa::InternId);
 type ExternCrateLoc = ItemLoc<ExternCrate>;
 impl_intern!(ExternCrateId, ExternCrateLoc, intern_extern_crate, lookup_intern_extern_crate);
+impl_loc!(ExternCrateLoc, id: ExternCrate, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct ExternBlockId(salsa::InternId);
 type ExternBlockLoc = ItemLoc<ExternBlock>;
 impl_intern!(ExternBlockId, ExternBlockLoc, intern_extern_block, lookup_intern_extern_block);
+impl_loc!(ExternBlockLoc, id: ExternBlock, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum MacroExpander {
@@ -389,6 +425,7 @@ pub struct Macro2Loc {
     pub edition: Edition,
 }
 impl_intern!(Macro2Id, Macro2Loc, intern_macro2, lookup_intern_macro2);
+impl_loc!(Macro2Loc, id: Macro2, container: ModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct MacroRulesId(salsa::InternId);
@@ -401,6 +438,7 @@ pub struct MacroRulesLoc {
     pub edition: Edition,
 }
 impl_intern!(MacroRulesId, MacroRulesLoc, intern_macro_rules, lookup_intern_macro_rules);
+impl_loc!(MacroRulesLoc, id: MacroRules, container: ModuleId);
 
 bitflags::bitflags! {
     #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -421,6 +459,7 @@ pub struct ProcMacroLoc {
     pub edition: Edition,
 }
 impl_intern!(ProcMacroId, ProcMacroLoc, intern_proc_macro, lookup_intern_proc_macro);
+impl_loc!(ProcMacroLoc, id: Function, container: CrateRootModuleId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct BlockId(salsa::InternId);
@@ -996,16 +1035,23 @@ pub trait HasModule {
     }
 }
 
-impl<N: ItemTreeModItemNode> HasModule for AssocItemLoc<N> {
+// In theory this impl should work out for us, but rustc thinks it collides with all the other
-    #[inline]
+// manual impls that do not have a ModuleId container...
-    fn module(&self, db: &dyn DefDatabase) -> ModuleId {
+// impl<N, ItemId, Data> HasModule for ItemId
-        self.container.module(db)
+// where
-    }
+//     N: ItemTreeNode,
-}
+//     ItemId: for<'db> Lookup<Database<'db> = dyn DefDatabase + 'db, Data = Data> + Copy,
+//     Data: ItemTreeLoc<Id = N, Container = ModuleId>,
+// {
+//     #[inline]
+//     fn module(&self, db: &dyn DefDatabase) -> ModuleId {
+//         self.lookup(db).container()
+//     }
+// }
 
 impl<N, ItemId> HasModule for ItemId
 where
-    N: ItemTreeModItemNode,
+    N: ItemTreeNode,
     ItemId: for<'db> Lookup<Database<'db> = dyn DefDatabase + 'db, Data = ItemLoc<N>> + Copy,
 {
     #[inline]
@@ -1031,10 +1077,7 @@ where
 #[inline]
 fn module_for_assoc_item_loc<'db>(
     db: &(dyn 'db + DefDatabase),
-    id: impl Lookup<
+    id: impl Lookup<Database<'db> = dyn DefDatabase + 'db, Data = AssocItemLoc<impl ItemTreeNode>>,
-        Database<'db> = dyn DefDatabase + 'db,
-        Data = AssocItemLoc<impl ItemTreeModItemNode>,
-    >,
 ) -> ModuleId {
     id.lookup(db).container.module(db)
 }

crates/hir-def/src/nameres/collector.rs

@@ -33,8 +33,8 @@ use crate::{
     db::DefDatabase,
     item_scope::{ImportId, ImportOrExternCrate, ImportType, PerNsGlobImports},
     item_tree::{
-        self, ExternCrate, Fields, FileItemTreeId, ImportKind, ItemTree, ItemTreeId,
+        self, ExternCrate, Fields, FileItemTreeId, ImportKind, ItemTree, ItemTreeId, ItemTreeNode,
-        ItemTreeModItemNode, Macro2, MacroCall, MacroRules, Mod, ModItem, ModKind, TreeId,
+        Macro2, MacroCall, MacroRules, Mod, ModItem, ModKind, TreeId,
     },
     macro_call_as_call_id, macro_call_as_call_id_with_eager,
     nameres::{

crates/hir-def/src/src.rs

@@ -4,91 +4,29 @@ use hir_expand::InFile;
 use la_arena::ArenaMap;
 use syntax::ast;
 
-use crate::{
+use crate::{db::DefDatabase, item_tree::ItemTreeNode, ItemTreeLoc, Lookup, UseId};
-    db::DefDatabase, item_tree::ItemTreeModItemNode, AssocItemLoc, EnumVariantLoc, ItemLoc, Lookup,
-    Macro2Loc, MacroRulesLoc, ProcMacroLoc, UseId,
-};
 
 pub trait HasSource {
     type Value;
     fn source(&self, db: &dyn DefDatabase) -> InFile<Self::Value>;
 }
 
-impl<N: ItemTreeModItemNode> HasSource for AssocItemLoc<N> {
+impl<T> HasSource for T
-    type Value = N::Source;
+where
-
+    T: ItemTreeLoc,
-    fn source(&self, db: &dyn DefDatabase) -> InFile<N::Source> {
+    T::Id: ItemTreeNode,
-        let tree = self.id.item_tree(db);
+{
-        let ast_id_map = db.ast_id_map(self.id.file_id());
+    type Value = <T::Id as ItemTreeNode>::Source;
-        let root = db.parse_or_expand(self.id.file_id());
-        let node = &tree[self.id.value];
-
-        InFile::new(self.id.file_id(), ast_id_map.get(node.ast_id()).to_node(&root))
-    }
-}
-
-impl<N: ItemTreeModItemNode> HasSource for ItemLoc<N> {
-    type Value = N::Source;
-
-    fn source(&self, db: &dyn DefDatabase) -> InFile<N::Source> {
-        let tree = self.id.item_tree(db);
-        let ast_id_map = db.ast_id_map(self.id.file_id());
-        let root = db.parse_or_expand(self.id.file_id());
-        let node = &tree[self.id.value];
-
-        InFile::new(self.id.file_id(), ast_id_map.get(node.ast_id()).to_node(&root))
-    }
-}
-
-impl HasSource for EnumVariantLoc {
-    type Value = ast::Variant;
-
-    fn source(&self, db: &dyn DefDatabase) -> InFile<ast::Variant> {
-        let tree = self.id.item_tree(db);
-        let ast_id_map = db.ast_id_map(self.id.file_id());
-        let root = db.parse_or_expand(self.id.file_id());
-        let node = &tree[self.id.value];
-
-        InFile::new(self.id.file_id(), ast_id_map.get(node.ast_id).to_node(&root))
-    }
-}
-
-impl HasSource for Macro2Loc {
-    type Value = ast::MacroDef;
 
     fn source(&self, db: &dyn DefDatabase) -> InFile<Self::Value> {
-        let tree = self.id.item_tree(db);
+        let id = self.item_tree_id();
-        let ast_id_map = db.ast_id_map(self.id.file_id());
+        let file_id = id.file_id();
-        let root = db.parse_or_expand(self.id.file_id());
+        let tree = id.item_tree(db);
-        let node = &tree[self.id.value];
+        let ast_id_map = db.ast_id_map(file_id);
+        let root = db.parse_or_expand(file_id);
+        let node = &tree[id.value];
 
-        InFile::new(self.id.file_id(), ast_id_map.get(node.ast_id()).to_node(&root))
+        InFile::new(file_id, ast_id_map.get(node.ast_id()).to_node(&root))
-    }
-}
-
-impl HasSource for MacroRulesLoc {
-    type Value = ast::MacroRules;
-
-    fn source(&self, db: &dyn DefDatabase) -> InFile<Self::Value> {
-        let tree = self.id.item_tree(db);
-        let ast_id_map = db.ast_id_map(self.id.file_id());
-        let root = db.parse_or_expand(self.id.file_id());
-        let node = &tree[self.id.value];
-
-        InFile::new(self.id.file_id(), ast_id_map.get(node.ast_id()).to_node(&root))
-    }
-}
-
-impl HasSource for ProcMacroLoc {
-    type Value = ast::Fn;
-
-    fn source(&self, db: &dyn DefDatabase) -> InFile<Self::Value> {
-        let tree = self.id.item_tree(db);
-        let ast_id_map = db.ast_id_map(self.id.file_id());
-        let root = db.parse_or_expand(self.id.file_id());
-        let node = &tree[self.id.value];
-
-        InFile::new(self.id.file_id(), ast_id_map.get(node.ast_id()).to_node(&root))
     }
 }
 

crates/hir-ty/src/display.rs

@@ -814,9 +814,8 @@ impl HirDisplay for Ty {
 
                             // Don't count Sized but count when it absent
                             // (i.e. when explicit ?Sized bound is set).
-                            let default_sized = SizedByDefault::Sized {
+                            let default_sized =
-                                anchor: func.lookup(db.upcast()).module(db.upcast()).krate(),
+                                SizedByDefault::Sized { anchor: func.krate(db.upcast()) };
-                            };
                             let sized_bounds = bounds
                                 .skip_binders()
                                 .iter()
@@ -1025,7 +1024,7 @@ impl HirDisplay for Ty {
                         let data =
                             (*datas).as_ref().map(|rpit| rpit.impl_traits[idx].bounds.clone());
                         let bounds = data.substitute(Interner, &parameters);
-                        let krate = func.lookup(db.upcast()).module(db.upcast()).krate();
+                        let krate = func.krate(db.upcast());
                         write_bounds_like_dyn_trait_with_prefix(
                             f,
                             "impl",
@@ -1191,7 +1190,7 @@ impl HirDisplay for Ty {
                         let data =
                             (*datas).as_ref().map(|rpit| rpit.impl_traits[idx].bounds.clone());
                         let bounds = data.substitute(Interner, &opaque_ty.substitution);
-                        let krate = func.lookup(db.upcast()).module(db.upcast()).krate();
+                        let krate = func.krate(db.upcast());
                         write_bounds_like_dyn_trait_with_prefix(
                             f,
                             "impl",

crates/hir-ty/src/lower.rs

@@ -1225,7 +1225,7 @@ impl<'a> TyLoweringContext<'a> {
                 .collect();
 
             if !ctx.unsized_types.borrow().contains(&self_ty) {
-                let krate = func.lookup(ctx.db.upcast()).module(ctx.db.upcast()).krate();
+                let krate = func.krate(ctx.db.upcast());
                 let sized_trait = ctx
                     .db
                     .lang_item(krate, LangItem::Sized)
@@ -1824,11 +1824,10 @@ impl CallableDefId {
     pub fn krate(self, db: &dyn HirDatabase) -> CrateId {
         let db = db.upcast();
         match self {
-            CallableDefId::FunctionId(f) => f.lookup(db).module(db),
+            CallableDefId::FunctionId(f) => f.krate(db),
-            CallableDefId::StructId(s) => s.lookup(db).container,
+            CallableDefId::StructId(s) => s.krate(db),
-            CallableDefId::EnumVariantId(e) => e.module(db),
+            CallableDefId::EnumVariantId(e) => e.krate(db),
         }
-        .krate()
     }
 }
 

crates/hir/src/lib.rs

@@ -44,7 +44,7 @@ use hir_def::{
     data::adt::VariantData,
     generics::{LifetimeParamData, TypeOrConstParamData, TypeParamProvenance},
     hir::{BindingAnnotation, BindingId, ExprOrPatId, LabelId, Pat},
-    item_tree::ItemTreeModItemNode,
+    item_tree::ItemTreeNode,
     lang_item::LangItemTarget,
     layout::{self, ReprOptions, TargetDataLayout},
     nameres::{self, diagnostics::DefDiagnostic},
@@ -1768,7 +1768,7 @@ pub struct Function {
 
 impl Function {
     pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.id.lookup(db.upcast()).module(db.upcast()).into()
+        self.id.module(db.upcast()).into()
     }
 
     pub fn name(self, db: &dyn HirDatabase) -> Name {
@@ -1909,8 +1909,7 @@ impl Function {
         {
             return None;
         }
-        let loc = self.id.lookup(db.upcast());
+        let def_map = db.crate_def_map(HasModule::krate(&self.id, db.upcast()));
-        let def_map = db.crate_def_map(HasModule::krate(&loc, db.upcast()));
         def_map.fn_as_proc_macro(self.id).map(|id| Macro { id: id.into() })
     }
 
@@ -2119,7 +2118,7 @@ pub struct Const {
 
 impl Const {
     pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
+        Module { id: self.id.module(db.upcast()) }
     }
 
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
@@ -2174,7 +2173,7 @@ pub struct Static {
 
 impl Static {
     pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
+        Module { id: self.id.module(db.upcast()) }
     }
 
     pub fn name(self, db: &dyn HirDatabase) -> Name {
@@ -2293,7 +2292,7 @@ impl TypeAlias {
     }
 
     pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
+        Module { id: self.id.module(db.upcast()) }
     }
 
     pub fn type_ref(self, db: &dyn HirDatabase) -> Option<TypeRef> {
@@ -2566,15 +2565,15 @@ impl AsAssocItem for DefWithBody {
     }
 }
 
-fn as_assoc_item<'db, ID, DEF, AST>(
+fn as_assoc_item<'db, ID, DEF, LOC>(
     db: &(dyn HirDatabase + 'db),
     ctor: impl FnOnce(DEF) -> AssocItem,
     id: ID,
 ) -> Option<AssocItem>
 where
-    ID: Lookup<Database<'db> = dyn DefDatabase + 'db, Data = AssocItemLoc<AST>>,
+    ID: Lookup<Database<'db> = dyn DefDatabase + 'db, Data = AssocItemLoc<LOC>>,
     DEF: From<ID>,
-    AST: ItemTreeModItemNode,
+    LOC: ItemTreeNode,
 {
     match id.lookup(db.upcast()).container {
         ItemContainerId::TraitId(_) | ItemContainerId::ImplId(_) => Some(ctor(DEF::from(id))),