6 files changed, 48 insertions, 24 deletions

diff --git a/crates/hir/src/attrs.rs b/crates/hir/src/attrs.rs
index 99fb65bac..9e6a3e155 100644
--- a/crates/hir/src/attrs.rs
+++ b/crates/hir/src/attrs.rs
@@ -2,6 +2,7 @@
 use hir_def::{
     attr::{Attrs, Documentation},
     path::ModPath,
+    per_ns::PerNs,
     resolver::HasResolver,
     AttrDefId, GenericParamId, ModuleDefId,
 };
@@ -112,6 +113,11 @@ fn resolve_doc_path(
     let path = ast::Path::parse(link).ok()?;
     let modpath = ModPath::from_src(path, &Hygiene::new_unhygienic()).unwrap();
     let resolved = resolver.resolve_module_path_in_items(db.upcast(), &modpath);
+    if resolved == PerNs::none() {
+        if let Some(trait_id) = resolver.resolve_module_path_in_trait_items(db.upcast(), &modpath) {
+            return Some(ModuleDefId::TraitId(trait_id));
+        };
+    }
     let def = match ns {
         Some(Namespace::Types) => resolved.take_types()?,
         Some(Namespace::Values) => resolved.take_values()?,
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 6cbf5cecf..c34a99d90 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -90,7 +90,7 @@ impl Crate {
     }
 
     pub fn root_module(self, db: &dyn HirDatabase) -> Module {
-        let module_id = db.crate_def_map(self.id).root;
+        let module_id = db.crate_def_map(self.id).root();
         Module::new(self, module_id)
     }
 
@@ -281,7 +281,7 @@ impl Module {
 
     /// Name of this module.
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         let parent = def_map[self.id.local_id].parent?;
         def_map[parent].children.iter().find_map(|(name, module_id)| {
             if *module_id == self.id.local_id {
@@ -302,12 +302,12 @@ impl Module {
     /// in the module tree of any target in `Cargo.toml`.
     pub fn crate_root(self, db: &dyn HirDatabase) -> Module {
         let def_map = db.crate_def_map(self.id.krate);
-        self.with_module_id(def_map.root)
+        self.with_module_id(def_map.root())
     }
 
     /// Iterates over all child modules.
     pub fn children(self, db: &dyn HirDatabase) -> impl Iterator<Item = Module> {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         let children = def_map[self.id.local_id]
             .children
             .iter()
@@ -318,7 +318,7 @@ impl Module {
 
     /// Finds a parent module.
     pub fn parent(self, db: &dyn HirDatabase) -> Option<Module> {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         let parent_id = def_map[self.id.local_id].parent?;
         Some(self.with_module_id(parent_id))
     }
@@ -339,7 +339,7 @@ impl Module {
         db: &dyn HirDatabase,
         visible_from: Option<Module>,
     ) -> Vec<(Name, ScopeDef)> {
-        db.crate_def_map(self.id.krate)[self.id.local_id]
+        self.id.def_map(db.upcast())[self.id.local_id]
             .scope
             .entries()
             .filter_map(|(name, def)| {
@@ -362,14 +362,14 @@ impl Module {
     }
 
     pub fn visibility_of(self, db: &dyn HirDatabase, def: &ModuleDef) -> Option<Visibility> {
-        db.crate_def_map(self.id.krate)[self.id.local_id].scope.visibility_of(def.clone().into())
+        self.id.def_map(db.upcast())[self.id.local_id].scope.visibility_of(def.clone().into())
     }
 
     pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
         let _p = profile::span("Module::diagnostics").detail(|| {
             format!("{:?}", self.name(db).map_or("<unknown>".into(), |name| name.to_string()))
         });
-        let crate_def_map = db.crate_def_map(self.id.krate);
+        let crate_def_map = self.id.def_map(db.upcast());
         crate_def_map.add_diagnostics(db.upcast(), self.id.local_id, sink);
         for decl in self.declarations(db) {
             match decl {
@@ -396,12 +396,12 @@ impl Module {
     }
 
     pub fn declarations(self, db: &dyn HirDatabase) -> Vec<ModuleDef> {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         def_map[self.id.local_id].scope.declarations().map(ModuleDef::from).collect()
     }
 
     pub fn impl_defs(self, db: &dyn HirDatabase) -> Vec<Impl> {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         def_map[self.id.local_id].scope.impls().map(Impl::from).collect()
     }
 
@@ -1000,7 +1000,7 @@ impl MacroDef {
     /// early, in `hir_expand`, where modules simply do not exist yet.
     pub fn module(self, db: &dyn HirDatabase) -> Option<Module> {
         let krate = self.id.krate;
-        let module_id = db.crate_def_map(krate).root;
+        let module_id = db.crate_def_map(krate).root();
         Some(Module::new(Crate { id: krate }, module_id))
     }
 
@@ -1051,6 +1051,16 @@ impl AsAssocItem for TypeAlias {
         as_assoc_item(db, AssocItem::TypeAlias, self.id)
     }
 }
+impl AsAssocItem for ModuleDef {
+    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
+        match self {
+            ModuleDef::Function(it) => it.as_assoc_item(db),
+            ModuleDef::Const(it) => it.as_assoc_item(db),
+            ModuleDef::TypeAlias(it) => it.as_assoc_item(db),
+            _ => None,
+        }
+    }
+}
 fn as_assoc_item<ID, DEF, CTOR, AST>(db: &dyn HirDatabase, ctor: CTOR, id: ID) -> Option<AssocItem>
 where
     ID: Lookup<Data = AssocItemLoc<AST>>,
@@ -1091,6 +1101,13 @@ impl AssocItem {
             AssocContainerId::ContainerId(_) => panic!("invalid AssocItem"),
         }
     }
+
+    pub fn containing_trait(self, db: &dyn HirDatabase) -> Option<Trait> {
+        match self.container(db) {
+            AssocItemContainer::Trait(t) => Some(t),
+            _ => None,
+        }
+    }
 }
 
 impl HasVisibility for AssocItem {
@@ -2029,7 +2046,7 @@ impl Callable {
 pub enum ScopeDef {
     ModuleDef(ModuleDef),
     MacroDef(MacroDef),
-    GenericParam(TypeParam),
+    GenericParam(GenericParam),
     ImplSelfType(Impl),
     AdtSelfType(Adt),
     Local(Local),
diff --git a/crates/hir/src/db.rs b/crates/hir/src/db.rs
index d5d4cf5b6..d444f4bbb 100644
--- a/crates/hir/src/db.rs
+++ b/crates/hir/src/db.rs
@@ -1,13 +1,13 @@
 //! FIXME: write short doc here
 
 pub use hir_def::db::{
-    AttrsQuery, BodyQuery, BodyWithSourceMapQuery, ConstDataQuery, CrateDefMapQueryQuery,
-    CrateLangItemsQuery, DefDatabase, DefDatabaseStorage, EnumDataQuery, ExprScopesQuery,
-    FunctionDataQuery, GenericParamsQuery, ImplDataQuery, ImportMapQuery, InternConstQuery,
-    InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery, InternImplQuery,
-    InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery, InternUnionQuery,
-    ItemTreeQuery, LangItemQuery, StaticDataQuery, StructDataQuery, TraitDataQuery,
-    TypeAliasDataQuery, UnionDataQuery,
+    AttrsQuery, BlockDefMapQuery, BodyQuery, BodyWithSourceMapQuery, ConstDataQuery,
+    CrateDefMapQueryQuery, CrateLangItemsQuery, DefDatabase, DefDatabaseStorage, EnumDataQuery,
+    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, ImportMapQuery,
+    InternConstQuery, InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery,
+    InternImplQuery, InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery,
+    InternUnionQuery, ItemTreeQuery, LangItemQuery, StaticDataQuery, StructDataQuery,
+    TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, HygieneFrameQuery, InternEagerExpansionQuery,
diff --git a/crates/hir/src/has_source.rs b/crates/hir/src/has_source.rs
index 7c57d8378..262002671 100644
--- a/crates/hir/src/has_source.rs
+++ b/crates/hir/src/has_source.rs
@@ -24,12 +24,12 @@ pub trait HasSource {
 impl Module {
     /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
     pub fn definition_source(self, db: &dyn HirDatabase) -> InFile<ModuleSource> {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         def_map[self.id.local_id].definition_source(db.upcast())
     }
 
     pub fn is_mod_rs(self, db: &dyn HirDatabase) -> bool {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         match def_map[self.id.local_id].origin {
             ModuleOrigin::File { is_mod_rs, .. } => is_mod_rs,
             _ => false,
@@ -39,7 +39,7 @@ impl Module {
     /// Returns a node which declares this module, either a `mod foo;` or a `mod foo {}`.
     /// `None` for the crate root.
     pub fn declaration_source(self, db: &dyn HirDatabase) -> Option<InFile<ast::Module>> {
-        let def_map = db.crate_def_map(self.id.krate);
+        let def_map = self.id.def_map(db.upcast());
         def_map[self.id.local_id].declaration_source(db.upcast())
     }
 }
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index ab213e04c..0a30b4f5b 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -814,7 +814,7 @@ impl<'a> SemanticsScope<'a> {
                 }
                 resolver::ScopeDef::ImplSelfType(it) => ScopeDef::ImplSelfType(it.into()),
                 resolver::ScopeDef::AdtSelfType(it) => ScopeDef::AdtSelfType(it.into()),
-                resolver::ScopeDef::GenericParam(id) => ScopeDef::GenericParam(TypeParam { id }),
+                resolver::ScopeDef::GenericParam(id) => ScopeDef::GenericParam(id.into()),
                 resolver::ScopeDef::Local(pat_id) => {
                     let parent = resolver.body_owner().unwrap().into();
                     ScopeDef::Local(Local { parent, pat_id })
diff --git a/crates/hir/src/semantics/source_to_def.rs b/crates/hir/src/semantics/source_to_def.rs
index 9bf60c72a..775f7ec8b 100644
--- a/crates/hir/src/semantics/source_to_def.rs
+++ b/crates/hir/src/semantics/source_to_def.rs
@@ -31,6 +31,7 @@ impl SourceToDefCtx<'_, '_> {
     pub(super) fn file_to_def(&mut self, file: FileId) -> Option<ModuleId> {
         let _p = profile::span("SourceBinder::to_module_def");
         let (krate, local_id) = self.db.relevant_crates(file).iter().find_map(|&crate_id| {
+            // FIXME: inner items
             let crate_def_map = self.db.crate_def_map(crate_id);
             let local_id = crate_def_map.modules_for_file(file).next()?;
             Some((crate_id, local_id))
@@ -60,7 +61,7 @@ impl SourceToDefCtx<'_, '_> {
         }?;
 
         let child_name = src.value.name()?.as_name();
-        let def_map = self.db.crate_def_map(parent_module.krate);
+        let def_map = parent_module.def_map(self.db.upcast());
         let child_id = *def_map[parent_module.local_id].children.get(&child_name)?;
         Some(ModuleId { krate: parent_module.krate, local_id: child_id })
     }