4 files changed, 37 insertions, 27 deletions

diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 5bb7961b3..a9982a70f 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -8,7 +8,7 @@ use ra_syntax::SmolStr;
 
 use crate::{
     debug::HirDebugDatabase,
-    generics::{GenericDef, GenericParams},
+    generics::GenericDef,
     ids,
     lang_item::{LangItemTarget, LangItems},
     ty::{
@@ -24,8 +24,9 @@ use crate::{
 
 pub use hir_def::db::{
     BodyQuery, BodyWithSourceMapQuery, CrateDefMapQuery, DefDatabase2, DefDatabase2Storage,
-    EnumDataQuery, ExprScopesQuery, ImplDataQuery, InternDatabase, InternDatabaseStorage,
-    RawItemsQuery, RawItemsWithSourceMapQuery, StructDataQuery, TraitDataQuery,
+    EnumDataQuery, ExprScopesQuery, GenericParamsQuery, ImplDataQuery, InternDatabase,
+    InternDatabaseStorage, RawItemsQuery, RawItemsWithSourceMapQuery, StructDataQuery,
+    TraitDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, MacroArgQuery, MacroDefQuery, MacroExpandQuery,
@@ -36,9 +37,6 @@ pub use hir_expand::db::{
 #[salsa::query_group(DefDatabaseStorage)]
 #[salsa::requires(AstDatabase)]
 pub trait DefDatabase: HirDebugDatabase + DefDatabase2 {
-    #[salsa::invoke(crate::generics::generic_params_query)]
-    fn generic_params(&self, def: GenericDef) -> Arc<GenericParams>;
-
     #[salsa::invoke(FnData::fn_data_query)]
     fn fn_data(&self, func: Function) -> Arc<FnData>;
 
diff --git a/crates/ra_hir/src/generics.rs b/crates/ra_hir/src/generics.rs
index caedb90e6..54ed03642 100644
--- a/crates/ra_hir/src/generics.rs
+++ b/crates/ra_hir/src/generics.rs
@@ -2,7 +2,7 @@
 use std::sync::Arc;
 
 use crate::{
-    db::{AstDatabase, DefDatabase, HirDatabase},
+    db::{DefDatabase, HirDatabase},
     Adt, Const, Container, Enum, EnumVariant, Function, ImplBlock, Struct, Trait, TypeAlias, Union,
 };
 
@@ -31,21 +31,6 @@ impl_froms!(
     Const
 );
 
-pub(crate) fn generic_params_query(
-    db: &(impl DefDatabase + AstDatabase),
-    def: GenericDef,
-) -> Arc<GenericParams> {
-    let parent = match def {
-        GenericDef::Function(it) => it.container(db).map(GenericDef::from),
-        GenericDef::TypeAlias(it) => it.container(db).map(GenericDef::from),
-        GenericDef::Const(it) => it.container(db).map(GenericDef::from),
-        GenericDef::EnumVariant(it) => Some(it.parent_enum(db).into()),
-        GenericDef::Adt(_) | GenericDef::Trait(_) => None,
-        GenericDef::ImplBlock(_) => None,
-    };
-    Arc::new(GenericParams::new(db, def.into(), parent.map(|it| db.generic_params(it))))
-}
-
 impl GenericDef {
     pub(crate) fn resolver(&self, db: &impl HirDatabase) -> crate::Resolver {
         match self {
@@ -78,6 +63,6 @@ where
     T: Into<GenericDef> + Copy,
 {
     fn generic_params(self, db: &impl DefDatabase) -> Arc<GenericParams> {
-        db.generic_params(self.into())
+        db.generic_params(self.into().into())
     }
 }
diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index c6cd4369b..844f8bbe8 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -8,13 +8,14 @@ use ra_syntax::ast;
 use crate::{
     adt::{EnumData, StructData},
     body::{scope::ExprScopes, Body, BodySourceMap},
+    generics::GenericParams,
     impls::ImplData,
     nameres::{
         raw::{ImportSourceMap, RawItems},
         CrateDefMap,
     },
     traits::TraitData,
-    DefWithBodyId, EnumId, ImplId, ItemLoc, StructOrUnionId, TraitId,
+    DefWithBodyId, EnumId, GenericDefId, ImplId, ItemLoc, StructOrUnionId, TraitId,
 };
 
 #[salsa::query_group(InternDatabaseStorage)]
@@ -71,4 +72,7 @@ pub trait DefDatabase2: InternDatabase + AstDatabase {
 
     #[salsa::invoke(ExprScopes::expr_scopes_query)]
     fn expr_scopes(&self, def: DefWithBodyId) -> Arc<ExprScopes>;
+
+    #[salsa::invoke(GenericParams::generic_params_query)]
+    fn generic_params(&self, def: GenericDefId) -> Arc<GenericParams>;
 }
diff --git a/crates/ra_hir_def/src/generics.rs b/crates/ra_hir_def/src/generics.rs
index 17a5d5f43..f794eefbc 100644
--- a/crates/ra_hir_def/src/generics.rs
+++ b/crates/ra_hir_def/src/generics.rs
@@ -5,13 +5,12 @@
 use std::sync::Arc;
 
 use hir_expand::name::{self, AsName, Name};
-
 use ra_syntax::ast::{self, NameOwner, TypeBoundsOwner, TypeParamsOwner};
 
 use crate::{
     db::DefDatabase2,
     type_ref::{TypeBound, TypeRef},
-    AdtId, AstItemDef, GenericDefId, HasSource, Lookup,
+    AdtId, AstItemDef, ContainerId, GenericDefId, HasSource, Lookup,
 };
 
 /// Data about a generic parameter (to a function, struct, impl, ...).
@@ -43,7 +42,15 @@ pub struct WherePredicate {
 }
 
 impl GenericParams {
-    pub fn new(
+    pub(crate) fn generic_params_query(
+        db: &impl DefDatabase2,
+        def: GenericDefId,
+    ) -> Arc<GenericParams> {
+        let parent_generics = parent_generic_def(db, def).map(|it| db.generic_params(it));
+        Arc::new(GenericParams::new(db, def.into(), parent_generics))
+    }
+
+    fn new(
         db: &impl DefDatabase2,
         def: GenericDefId,
         parent_params: Option<Arc<GenericParams>>,
@@ -161,3 +168,19 @@ impl GenericParams {
         vec
     }
 }
+
+fn parent_generic_def(db: &impl DefDatabase2, def: GenericDefId) -> Option<GenericDefId> {
+    let container = match def {
+        GenericDefId::FunctionId(it) => it.lookup(db).container,
+        GenericDefId::TypeAliasId(it) => it.lookup(db).container,
+        GenericDefId::ConstId(it) => it.lookup(db).container,
+        GenericDefId::EnumVariantId(it) => return Some(it.parent.into()),
+        GenericDefId::AdtId(_) | GenericDefId::TraitId(_) | GenericDefId::ImplId(_) => return None,
+    };
+
+    match container {
+        ContainerId::ImplId(it) => Some(it.into()),
+        ContainerId::TraitId(it) => Some(it.into()),
+        ContainerId::ModuleId(_) => None,
+    }
+}