8 files changed, 138 insertions, 134 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 9b6276b51..c5539e076 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -30,7 +30,7 @@ use crate::{
         AstItemDef, ConstId, EnumId, FunctionId, MacroDefId, StaticId, StructId, TraitId,
         TypeAliasId,
     },
-    resolve::{Resolver, Scope, TypeNs},
+    resolve::{HasResolver, TypeNs},
     ty::{InferenceResult, Namespace, TraitRef},
     Either, HasSource, ImportId, Name, ScopeDef, Source, Ty,
 };
@@ -223,11 +223,6 @@ impl Module {
         }
     }
 
-    pub(crate) fn resolver(self, db: &impl DefDatabase) -> Resolver {
-        let def_map = db.crate_def_map(self.id.krate);
-        Resolver::default().push_module_scope(def_map, self.id.module_id)
-    }
-
     pub fn declarations(self, db: &impl DefDatabase) -> Vec<ModuleDef> {
         let def_map = db.crate_def_map(self.id.krate);
         def_map[self.id.module_id].scope.declarations().map(ModuleDef::from).collect()
@@ -315,15 +310,6 @@ impl Struct {
         db.type_for_def(self.into(), Namespace::Values)
     }
 
-    // FIXME move to a more general type
-    /// Builds a resolver for type references inside this struct.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        // take the outer scope...
-        let r = self.module(db).resolver(db);
-        // ...and add generic params, if present
-        r.push_generic_params_scope(db, self.into())
-    }
-
     fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
         db.struct_data(self.id.into()).variant_data.clone()
     }
@@ -339,22 +325,13 @@ impl Union {
         db.struct_data(self.id.into()).name.clone()
     }
 
-    pub fn module(self, db: &impl HirDatabase) -> Module {
+    pub fn module(self, db: &impl DefDatabase) -> Module {
         Module { id: self.id.0.module(db) }
     }
 
     pub fn ty(self, db: &impl HirDatabase) -> Ty {
         db.type_for_def(self.into(), Namespace::Types)
     }
-
-    // FIXME move to a more general type
-    /// Builds a resolver for type references inside this union.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        // take the outer scope...
-        let r = self.module(db).resolver(db);
-        // ...and add generic params, if present
-        r.push_generic_params_scope(db, self.into())
-    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -394,16 +371,6 @@ impl Enum {
     pub fn ty(self, db: &impl HirDatabase) -> Ty {
         db.type_for_def(self.into(), Namespace::Types)
     }
-
-    // FIXME: move to a more general type
-    /// Builds a resolver for type references inside this struct.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        // take the outer scope...
-        let r = self.module(db).resolver(db);
-        // ...and add generic params, if present
-        let r = r.push_generic_params_scope(db, self.into());
-        r.push_scope(Scope::AdtScope(self.into()))
-    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -475,14 +442,6 @@ impl Adt {
             .krate(),
         )
     }
-
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        match self {
-            Adt::Struct(it) => it.resolver(db),
-            Adt::Union(it) => it.resolver(db),
-            Adt::Enum(it) => it.resolver(db),
-        }
-    }
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
@@ -533,15 +492,6 @@ pub enum DefWithBody {
 impl_froms!(DefWithBody: Function, Const, Static);
 
 impl DefWithBody {
-    /// Builds a resolver for code inside this item.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        match self {
-            DefWithBody::Const(c) => c.resolver(db),
-            DefWithBody::Function(f) => f.resolver(db),
-            DefWithBody::Static(s) => s.resolver(db),
-        }
-    }
-
     pub(crate) fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
         match self {
             DefWithBody::Const(c) => c.krate(db),
@@ -738,15 +688,6 @@ impl Function {
         }
     }
 
-    // FIXME: move to a more general type for 'body-having' items
-    /// Builds a resolver for code inside this item.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        // take the outer scope...
-        let r = self.container(db).map_or_else(|| self.module(db).resolver(db), |c| c.resolver(db));
-        // ...and add generic params, if present
-        r.push_generic_params_scope(db, self.into())
-    }
-
     pub fn diagnostics(self, db: &impl HirDatabase, sink: &mut DiagnosticSink) {
         let infer = self.infer(db);
         infer.add_diagnostics(db, self, sink);
@@ -804,17 +745,6 @@ impl Const {
             ContainerId::ModuleId(_) => None,
         }
     }
-
-    // FIXME: move to a more general type for 'body-having' items
-    /// Builds a resolver for code inside this item.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        // take the outer scope...
-        let r = self
-            .impl_block(db)
-            .map(|ib| ib.resolver(db))
-            .unwrap_or_else(|| self.module(db).resolver(db));
-        r
-    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -874,12 +804,6 @@ impl Static {
         db.static_data(self)
     }
 
-    /// Builds a resolver for code inside this item.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        // take the outer scope...
-        self.module(db).resolver(db)
-    }
-
     pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
         db.infer(self.into())
     }
@@ -975,12 +899,6 @@ impl Trait {
     pub fn is_auto(self, db: &impl DefDatabase) -> bool {
         self.trait_data(db).auto
     }
-
-    pub(crate) fn resolver(self, db: &impl DefDatabase) -> Resolver {
-        let r = self.module(db).resolver(db);
-        // add generic params, if present
-        r.push_generic_params_scope(db, self.into())
-    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -1032,17 +950,6 @@ impl TypeAlias {
     pub fn name(self, db: &impl DefDatabase) -> Name {
         db.type_alias_data(self).name.clone()
     }
-
-    /// Builds a resolver for the type references in this type alias.
-    pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
-        // take the outer scope...
-        let r = self
-            .impl_block(db)
-            .map(|ib| ib.resolver(db))
-            .unwrap_or_else(|| self.module(db).resolver(db));
-        // ...and add generic params, if present
-        r.push_generic_params_scope(db, self.into())
-    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -1058,15 +965,6 @@ pub enum Container {
 }
 impl_froms!(Container: Trait, ImplBlock);
 
-impl Container {
-    pub(crate) fn resolver(self, db: &impl DefDatabase) -> Resolver {
-        match self {
-            Container::Trait(trait_) => trait_.resolver(db),
-            Container::ImplBlock(impl_block) => impl_block.resolver(db),
-        }
-    }
-}
-
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum AssocItem {
     Function(Function),
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index 8bfdda45e..869879bdf 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -11,6 +11,7 @@ use rustc_hash::FxHashSet;
 use crate::{
     db::HirDatabase,
     diagnostics::{MissingFields, MissingOkInTailExpr},
+    resolve::HasResolver,
     ty::{ApplicationTy, InferenceResult, Ty, TypeCtor},
     Adt, DefWithBody, Function, HasBody, Name, Path, Resolver,
 };
diff --git a/crates/ra_hir/src/generics.rs b/crates/ra_hir/src/generics.rs
index 54ed03642..f1bf2ee9d 100644
--- a/crates/ra_hir/src/generics.rs
+++ b/crates/ra_hir/src/generics.rs
@@ -2,8 +2,8 @@
 use std::sync::Arc;
 
 use crate::{
-    db::{DefDatabase, HirDatabase},
-    Adt, Const, Container, Enum, EnumVariant, Function, ImplBlock, Struct, Trait, TypeAlias, Union,
+    db::DefDatabase, Adt, Const, Container, Enum, EnumVariant, Function, ImplBlock, Struct, Trait,
+    TypeAlias, Union,
 };
 
 pub use hir_def::generics::{GenericParam, GenericParams, WherePredicate};
@@ -31,20 +31,6 @@ impl_froms!(
     Const
 );
 
-impl GenericDef {
-    pub(crate) fn resolver(&self, db: &impl HirDatabase) -> crate::Resolver {
-        match self {
-            GenericDef::Function(inner) => inner.resolver(db),
-            GenericDef::Adt(adt) => adt.resolver(db),
-            GenericDef::Trait(inner) => inner.resolver(db),
-            GenericDef::TypeAlias(inner) => inner.resolver(db),
-            GenericDef::ImplBlock(inner) => inner.resolver(db),
-            GenericDef::EnumVariant(inner) => inner.parent_enum(db).resolver(db),
-            GenericDef::Const(inner) => inner.resolver(db),
-        }
-    }
-}
-
 impl From<Container> for GenericDef {
     fn from(c: Container) -> Self {
         match c {
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index 492d964a4..964a3da8c 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -5,7 +5,7 @@ use ra_syntax::ast::{self};
 
 use crate::{
     db::{AstDatabase, DefDatabase, HirDatabase},
-    resolve::Resolver,
+    resolve::HasResolver,
     ty::Ty,
     AssocItem, Crate, HasSource, ImplBlock, Module, Source, TraitRef,
 };
@@ -50,12 +50,4 @@ impl ImplBlock {
     pub fn krate(&self, db: &impl DefDatabase) -> Crate {
         Crate { crate_id: self.module(db).id.krate }
     }
-
-    pub(crate) fn resolver(self, db: &impl DefDatabase) -> Resolver {
-        let r = self.module(db).resolver(db);
-        // add generic params, if present
-        let r = r.push_generic_params_scope(db, self.into());
-        let r = r.push_impl_block_scope(self);
-        r
-    }
 }
diff --git a/crates/ra_hir/src/resolve.rs b/crates/ra_hir/src/resolve.rs
index e5e768be9..b8e1b4dad 100644
--- a/crates/ra_hir/src/resolve.rs
+++ b/crates/ra_hir/src/resolve.rs
@@ -15,8 +15,8 @@ use crate::{
     db::{DefDatabase, HirDatabase},
     expr::{ExprScopes, PatId, ScopeId},
     generics::{GenericParams, HasGenericParams},
-    Adt, Const, DefWithBody, Enum, EnumVariant, Function, GenericDef, ImplBlock, Local, MacroDef,
-    ModuleDef, PerNs, Static, Struct, Trait, TypeAlias,
+    Adt, Const, Container, DefWithBody, Enum, EnumVariant, Function, GenericDef, ImplBlock, Local,
+    MacroDef, Module, ModuleDef, PerNs, Static, Struct, Trait, TypeAlias, Union,
 };
 
 #[derive(Debug, Clone, Default)]
@@ -486,3 +486,130 @@ impl Scope {
         }
     }
 }
+
+pub(crate) trait HasResolver {
+    /// Builds a resolver for type references inside this def.
+    fn resolver(self, db: &impl DefDatabase) -> Resolver;
+}
+
+impl HasResolver for Module {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        let def_map = db.crate_def_map(self.id.krate);
+        Resolver::default().push_module_scope(def_map, self.id.module_id)
+    }
+}
+
+impl HasResolver for Trait {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.module(db).resolver(db).push_generic_params_scope(db, self.into())
+    }
+}
+
+impl HasResolver for Struct {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.module(db)
+            .resolver(db)
+            .push_generic_params_scope(db, self.into())
+            .push_scope(Scope::AdtScope(self.into()))
+    }
+}
+
+impl HasResolver for Union {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.module(db)
+            .resolver(db)
+            .push_generic_params_scope(db, self.into())
+            .push_scope(Scope::AdtScope(self.into()))
+    }
+}
+
+impl HasResolver for Enum {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.module(db)
+            .resolver(db)
+            .push_generic_params_scope(db, self.into())
+            .push_scope(Scope::AdtScope(self.into()))
+    }
+}
+
+impl HasResolver for Adt {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        match self {
+            Adt::Struct(it) => it.resolver(db),
+            Adt::Union(it) => it.resolver(db),
+            Adt::Enum(it) => it.resolver(db),
+        }
+    }
+}
+
+impl HasResolver for Function {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.container(db)
+            .map(|c| c.resolver(db))
+            .unwrap_or_else(|| self.module(db).resolver(db))
+            .push_generic_params_scope(db, self.into())
+    }
+}
+
+impl HasResolver for DefWithBody {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        match self {
+            DefWithBody::Const(c) => c.resolver(db),
+            DefWithBody::Function(f) => f.resolver(db),
+            DefWithBody::Static(s) => s.resolver(db),
+        }
+    }
+}
+
+impl HasResolver for Const {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.container(db).map(|c| c.resolver(db)).unwrap_or_else(|| self.module(db).resolver(db))
+    }
+}
+
+impl HasResolver for Static {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.module(db).resolver(db)
+    }
+}
+
+impl HasResolver for TypeAlias {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.container(db)
+            .map(|ib| ib.resolver(db))
+            .unwrap_or_else(|| self.module(db).resolver(db))
+            .push_generic_params_scope(db, self.into())
+    }
+}
+
+impl HasResolver for Container {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        match self {
+            Container::Trait(trait_) => trait_.resolver(db),
+            Container::ImplBlock(impl_block) => impl_block.resolver(db),
+        }
+    }
+}
+
+impl HasResolver for GenericDef {
+    fn resolver(self, db: &impl DefDatabase) -> crate::Resolver {
+        match self {
+            GenericDef::Function(inner) => inner.resolver(db),
+            GenericDef::Adt(adt) => adt.resolver(db),
+            GenericDef::Trait(inner) => inner.resolver(db),
+            GenericDef::TypeAlias(inner) => inner.resolver(db),
+            GenericDef::ImplBlock(inner) => inner.resolver(db),
+            GenericDef::EnumVariant(inner) => inner.parent_enum(db).resolver(db),
+            GenericDef::Const(inner) => inner.resolver(db),
+        }
+    }
+}
+
+impl HasResolver for ImplBlock {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.module(db)
+            .resolver(db)
+            .push_generic_params_scope(db, self.into())
+            .push_impl_block_scope(self)
+    }
+}
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index fd9994098..727310f06 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -23,7 +23,7 @@ use crate::{
     db::HirDatabase,
     expr::{self, BodySourceMap, ExprScopes, ScopeId},
     ids::LocationCtx,
-    resolve::{ScopeDef, TypeNs, ValueNs},
+    resolve::{HasResolver, ScopeDef, TypeNs, ValueNs},
     ty::method_resolution::{self, implements_trait},
     AssocItem, Const, DefWithBody, Either, Enum, FromSource, Function, GenericParam, HasBody,
     HirFileId, Local, MacroDef, Module, Name, Path, Resolver, Static, Struct, Ty,
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index 092bc3a3f..7f9e81d64 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -40,7 +40,7 @@ use crate::{
     code_model::TypeAlias,
     db::HirDatabase,
     expr::{BindingAnnotation, Body, ExprId, PatId},
-    resolve::{Resolver, TypeNs},
+    resolve::{HasResolver, Resolver, TypeNs},
     ty::infer::diagnostics::InferenceDiagnostic,
     Adt, AssocItem, ConstData, DefWithBody, FloatTy, FnData, Function, HasBody, IntTy, Path,
     StructField, VariantDef,
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index 91e60b5ab..397ee7d5f 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -22,7 +22,7 @@ use crate::{
     db::HirDatabase,
     generics::HasGenericParams,
     generics::{GenericDef, WherePredicate},
-    resolve::{Resolver, TypeNs},
+    resolve::{HasResolver, Resolver, TypeNs},
     ty::{
         primitive::{FloatTy, IntTy, Uncertain},
         Adt,