Merge remote-tracking branch 'upstream/master' into 503-hover-doc-links

Hasn't fixed tests yet.

8 files changed, 520 insertions, 254 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 8c5e1b746..5d88c5c64 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -1,5 +1,5 @@
 //! FIXME: write short doc here
-use std::sync::Arc;
+use std::{iter, sync::Arc};
 
 use arrayvec::ArrayVec;
 use either::Either;
@@ -12,6 +12,7 @@ use hir_def::{
     import_map,
     per_ns::PerNs,
     resolver::{HasResolver, Resolver},
+    src::HasSource as _,
     type_ref::{Mutability, TypeRef},
     AdtId, AssocContainerId, ConstId, DefWithBodyId, EnumId, FunctionId, GenericDefId, HasModule,
     ImplId, LocalEnumVariantId, LocalFieldId, LocalModuleId, Lookup, ModuleId, StaticId, StructId,
@@ -25,21 +26,22 @@ use hir_expand::{
 use hir_ty::{
     autoderef,
     display::{HirDisplayError, HirFormatter},
-    expr::ExprValidator,
-    method_resolution,
-    unsafe_validation::UnsafeValidator,
-    ApplicationTy, Canonical, GenericPredicate, InEnvironment, Substs, TraitEnvironment, Ty,
-    TyDefId, TypeCtor,
+    method_resolution, ApplicationTy, CallableDefId, Canonical, FnSig, GenericPredicate,
+    InEnvironment, Substs, TraitEnvironment, Ty, TyDefId, TypeCtor,
 };
-use ra_db::{CrateId, CrateName, Edition, FileId};
+use ra_db::{CrateId, Edition, FileId};
 use ra_prof::profile;
-use ra_syntax::ast::{self, AttrsOwner, NameOwner};
+use ra_syntax::{
+    ast::{self, AttrsOwner, NameOwner},
+    AstNode,
+};
 use rustc_hash::FxHashSet;
+use stdx::impl_from;
 
 use crate::{
     db::{DefDatabase, HirDatabase},
     has_source::HasSource,
-    CallableDef, HirDisplay, InFile, Name,
+    HirDisplay, InFile, Name,
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
@@ -94,8 +96,8 @@ impl Crate {
         db.crate_graph()[self.id].edition
     }
 
-    pub fn display_name(self, db: &dyn HirDatabase) -> Option<CrateName> {
-        db.crate_graph()[self.id].display_name.as_ref().cloned()
+    pub fn display_name(self, db: &dyn HirDatabase) -> Option<String> {
+        db.crate_graph()[self.id].display_name.clone()
     }
 
     pub fn query_external_importables(
@@ -139,8 +141,8 @@ pub enum ModuleDef {
     TypeAlias(TypeAlias),
     BuiltinType(BuiltinType),
 }
-impl_froms!(
-    ModuleDef: Module,
+impl_from!(
+    Module,
     Function,
     Adt(Struct, Enum, Union),
     EnumVariant,
@@ -149,6 +151,7 @@ impl_froms!(
     Trait,
     TypeAlias,
     BuiltinType
+    for ModuleDef
 );
 
 impl ModuleDef {
@@ -376,8 +379,8 @@ pub struct Field {
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum FieldSource {
-    Named(ast::RecordFieldDef),
-    Pos(ast::TupleFieldDef),
+    Named(ast::RecordField),
+    Pos(ast::TupleField),
 }
 
 impl Field {
@@ -556,7 +559,7 @@ pub enum Adt {
     Union(Union),
     Enum(Enum),
 }
-impl_froms!(Adt: Struct, Union, Enum);
+impl_from!(Struct, Union, Enum for Adt);
 
 impl Adt {
     pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
@@ -599,7 +602,7 @@ pub enum VariantDef {
     Union(Union),
     EnumVariant(EnumVariant),
 }
-impl_froms!(VariantDef: Struct, Union, EnumVariant);
+impl_from!(Struct, Union, EnumVariant for VariantDef);
 
 impl VariantDef {
     pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
@@ -642,8 +645,7 @@ pub enum DefWithBody {
     Static(Static),
     Const(Const),
 }
-
-impl_froms!(DefWithBody: Function, Const, Static);
+impl_from!(Function, Const, Static for DefWithBody);
 
 impl DefWithBody {
     pub fn module(self, db: &dyn HirDatabase) -> Module {
@@ -694,13 +696,7 @@ impl Function {
     }
 
     pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
-        let _p = profile("Function::diagnostics");
-        let infer = db.infer(self.id.into());
-        infer.add_diagnostics(db, self.id, sink);
-        let mut validator = ExprValidator::new(self.id, infer.clone(), sink);
-        validator.validate_body(db);
-        let mut validator = UnsafeValidator::new(self.id, infer, sink);
-        validator.validate_body(db);
+        hir_ty::diagnostics::validate_body(db, self.id.into(), sink)
     }
 }
 
@@ -945,14 +941,15 @@ pub enum GenericDef {
     // consts can have type parameters from their parents (i.e. associated consts of traits)
     Const(Const),
 }
-impl_froms!(
-    GenericDef: Function,
+impl_from!(
+    Function,
     Adt(Struct, Enum, Union),
     Trait,
     TypeAlias,
     ImplDef,
     EnumVariant,
     Const
+    for GenericDef
 );
 
 impl GenericDef {
@@ -973,6 +970,16 @@ pub struct Local {
 }
 
 impl Local {
+    pub fn is_param(self, db: &dyn HirDatabase) -> bool {
+        let src = self.source(db);
+        match src.value {
+            Either::Left(bind_pat) => {
+                bind_pat.syntax().ancestors().any(|it| ast::Param::can_cast(it.kind()))
+            }
+            Either::Right(_self_param) => true,
+        }
+    }
+
     // FIXME: why is this an option? It shouldn't be?
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
         let body = db.body(self.parent.into());
@@ -1071,12 +1078,14 @@ pub struct ImplDef {
 
 impl ImplDef {
     pub fn all_in_crate(db: &dyn HirDatabase, krate: Crate) -> Vec<ImplDef> {
-        let impls = db.impls_in_crate(krate.id);
-        impls.all_impls().map(Self::from).collect()
+        let inherent = db.inherent_impls_in_crate(krate.id);
+        let trait_ = db.trait_impls_in_crate(krate.id);
+
+        inherent.all_impls().chain(trait_.all_impls()).map(Self::from).collect()
     }
     pub fn for_trait(db: &dyn HirDatabase, krate: Crate, trait_: Trait) -> Vec<ImplDef> {
-        let impls = db.impls_in_crate(krate.id);
-        impls.lookup_impl_defs_for_trait(trait_.id).map(Self::from).collect()
+        let impls = db.trait_impls_in_crate(krate.id);
+        impls.for_trait(trait_.id).map(Self::from).collect()
     }
 
     pub fn target_trait(self, db: &dyn HirDatabase) -> Option<TypeRef> {
@@ -1178,6 +1187,12 @@ impl Type {
         Type::new(db, krate, def, ty)
     }
 
+    pub fn is_unit(&self) -> bool {
+        matches!(
+            self.ty.value,
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::Tuple { cardinality: 0 }, .. })
+        )
+    }
     pub fn is_bool(&self) -> bool {
         matches!(self.ty.value, Ty::Apply(ApplicationTy { ctor: TypeCtor::Bool, .. }))
     }
@@ -1205,7 +1220,7 @@ impl Type {
             None => return false,
         };
 
-        let canonical_ty = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical_ty = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
         method_resolution::implements_trait(
             &canonical_ty,
             db,
@@ -1229,15 +1244,20 @@ impl Type {
                 self.ty.environment.clone(),
                 hir_ty::Obligation::Trait(trait_ref),
             ),
-            num_vars: 0,
+            kinds: Arc::new([]),
         };
 
         db.trait_solve(self.krate, goal).is_some()
     }
 
-    // FIXME: this method is broken, as it doesn't take closures into account.
-    pub fn as_callable(&self) -> Option<CallableDef> {
-        Some(self.ty.value.as_callable()?.0)
+    pub fn as_callable(&self, db: &dyn HirDatabase) -> Option<Callable> {
+        let def = match self.ty.value {
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::FnDef(def), parameters: _ }) => Some(def),
+            _ => None,
+        };
+
+        let sig = self.ty.value.callable_sig(db)?;
+        Some(Callable { ty: self.clone(), sig, def, is_bound_method: false })
     }
 
     pub fn is_closure(&self) -> bool {
@@ -1304,7 +1324,7 @@ impl Type {
     pub fn autoderef<'a>(&'a self, db: &'a dyn HirDatabase) -> impl Iterator<Item = Type> + 'a {
         // There should be no inference vars in types passed here
         // FIXME check that?
-        let canonical = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
         let environment = self.ty.environment.clone();
         let ty = InEnvironment { value: canonical, environment };
         autoderef(db, Some(self.krate), ty)
@@ -1321,10 +1341,10 @@ impl Type {
         mut callback: impl FnMut(AssocItem) -> Option<T>,
     ) -> Option<T> {
         for krate in self.ty.value.def_crates(db, krate.id)? {
-            let impls = db.impls_in_crate(krate);
+            let impls = db.inherent_impls_in_crate(krate);
 
-            for impl_def in impls.lookup_impl_defs(&self.ty.value) {
-                for &item in db.impl_data(impl_def).items.iter() {
+            for impl_def in impls.for_self_ty(&self.ty.value) {
+                for &item in db.impl_data(*impl_def).items.iter() {
                     if let Some(result) = callback(item.into()) {
                         return Some(result);
                     }
@@ -1345,7 +1365,7 @@ impl Type {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
 
         let env = self.ty.environment.clone();
         let krate = krate.id;
@@ -1376,7 +1396,7 @@ impl Type {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
 
         let env = self.ty.environment.clone();
         let krate = krate.id;
@@ -1522,6 +1542,74 @@ impl HirDisplay for Type {
     }
 }
 
+// FIXME: closures
+#[derive(Debug)]
+pub struct Callable {
+    ty: Type,
+    sig: FnSig,
+    def: Option<CallableDefId>,
+    pub(crate) is_bound_method: bool,
+}
+
+pub enum CallableKind {
+    Function(Function),
+    TupleStruct(Struct),
+    TupleEnumVariant(EnumVariant),
+    Closure,
+}
+
+impl Callable {
+    pub fn kind(&self) -> CallableKind {
+        match self.def {
+            Some(CallableDefId::FunctionId(it)) => CallableKind::Function(it.into()),
+            Some(CallableDefId::StructId(it)) => CallableKind::TupleStruct(it.into()),
+            Some(CallableDefId::EnumVariantId(it)) => CallableKind::TupleEnumVariant(it.into()),
+            None => CallableKind::Closure,
+        }
+    }
+    pub fn receiver_param(&self, db: &dyn HirDatabase) -> Option<ast::SelfParam> {
+        let func = match self.def {
+            Some(CallableDefId::FunctionId(it)) if self.is_bound_method => it,
+            _ => return None,
+        };
+        let src = func.lookup(db.upcast()).source(db.upcast());
+        let param_list = src.value.param_list()?;
+        param_list.self_param()
+    }
+    pub fn n_params(&self) -> usize {
+        self.sig.params().len() - if self.is_bound_method { 1 } else { 0 }
+    }
+    pub fn params(
+        &self,
+        db: &dyn HirDatabase,
+    ) -> Vec<(Option<Either<ast::SelfParam, ast::Pat>>, Type)> {
+        let types = self
+            .sig
+            .params()
+            .iter()
+            .skip(if self.is_bound_method { 1 } else { 0 })
+            .map(|ty| self.ty.derived(ty.clone()));
+        let patterns = match self.def {
+            Some(CallableDefId::FunctionId(func)) => {
+                let src = func.lookup(db.upcast()).source(db.upcast());
+                src.value.param_list().map(|param_list| {
+                    param_list
+                        .self_param()
+                        .map(|it| Some(Either::Left(it)))
+                        .filter(|_| !self.is_bound_method)
+                        .into_iter()
+                        .chain(param_list.params().map(|it| it.pat().map(Either::Right)))
+                })
+            }
+            _ => None,
+        };
+        patterns.into_iter().flatten().chain(iter::repeat(None)).zip(types).collect()
+    }
+    pub fn return_type(&self) -> Type {
+        self.ty.derived(self.sig.ret().clone())
+    }
+}
+
 /// For IDE only
 #[derive(Debug)]
 pub enum ScopeDef {
@@ -1581,8 +1669,8 @@ pub enum AttrDef {
     MacroDef(MacroDef),
 }
 
-impl_froms!(
-    AttrDef: Module,
+impl_from!(
+    Module,
     Field,
     Adt(Struct, Enum, Union),
     EnumVariant,
@@ -1592,6 +1680,7 @@ impl_froms!(
     Trait,
     TypeAlias,
     MacroDef
+    for AttrDef
 );
 
 pub trait HasAttrs {
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index bb67952de..a2b9f3e35 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -11,15 +11,15 @@ pub use hir_def::db::{
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, InternEagerExpansionQuery, InternMacroQuery,
-    MacroArgQuery, MacroDefQuery, MacroExpandQuery, ParseMacroQuery,
+    MacroArgTextQuery, MacroDefQuery, MacroExpandQuery, ParseMacroQuery,
 };
 pub use hir_ty::db::{
     AssociatedTyDataQuery, AssociatedTyValueQuery, CallableItemSignatureQuery, FieldTypesQuery,
     GenericDefaultsQuery, GenericPredicatesForParamQuery, GenericPredicatesQuery, HirDatabase,
-    HirDatabaseStorage, ImplDatumQuery, ImplSelfTyQuery, ImplTraitQuery, ImplsFromDepsQuery,
-    ImplsInCrateQuery, InferQueryQuery, InternAssocTyValueQuery, InternChalkImplQuery,
-    InternTypeCtorQuery, InternTypeParamIdQuery, ReturnTypeImplTraitsQuery, StructDatumQuery,
-    TraitDatumQuery, TraitSolveQuery, TyQuery, ValueTyQuery,
+    HirDatabaseStorage, ImplDatumQuery, ImplSelfTyQuery, ImplTraitQuery, InferQueryQuery,
+    InherentImplsInCrateQuery, InternTypeParamIdQuery, ReturnTypeImplTraitsQuery, StructDatumQuery,
+    TraitDatumQuery, TraitImplsInCrateQuery, TraitImplsInDepsQuery, TraitSolveQuery, TyQuery,
+    ValueTyQuery,
 };
 
 #[test]
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index c82883d0c..266b513dc 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,4 +1,8 @@
 //! FIXME: write short doc here
 pub use hir_def::diagnostics::UnresolvedModule;
-pub use hir_expand::diagnostics::{AstDiagnostic, Diagnostic, DiagnosticSink};
-pub use hir_ty::diagnostics::{MissingFields, MissingMatchArms, MissingOkInTailExpr, NoSuchField};
+pub use hir_expand::diagnostics::{
+    AstDiagnostic, Diagnostic, DiagnosticSink, DiagnosticSinkBuilder,
+};
+pub use hir_ty::diagnostics::{
+    MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, NoSuchField,
+};
diff --git a/crates/ra_hir/src/has_source.rs b/crates/ra_hir/src/has_source.rs
index 76c32fc17..1c691d961 100644
--- a/crates/ra_hir/src/has_source.rs
+++ b/crates/ra_hir/src/has_source.rs
@@ -57,56 +57,56 @@ impl HasSource for Field {
     }
 }
 impl HasSource for Struct {
-    type Ast = ast::StructDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::StructDef> {
+    type Ast = ast::Struct;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Struct> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 impl HasSource for Union {
-    type Ast = ast::UnionDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::UnionDef> {
+    type Ast = ast::Union;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Union> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 impl HasSource for Enum {
-    type Ast = ast::EnumDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::EnumDef> {
+    type Ast = ast::Enum;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Enum> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 impl HasSource for EnumVariant {
-    type Ast = ast::EnumVariant;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::EnumVariant> {
+    type Ast = ast::Variant;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Variant> {
         self.parent.id.child_source(db.upcast()).map(|map| map[self.id].clone())
     }
 }
 impl HasSource for Function {
-    type Ast = ast::FnDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::FnDef> {
+    type Ast = ast::Fn;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Fn> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 impl HasSource for Const {
-    type Ast = ast::ConstDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::ConstDef> {
+    type Ast = ast::Const;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Const> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 impl HasSource for Static {
-    type Ast = ast::StaticDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::StaticDef> {
+    type Ast = ast::Static;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Static> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 impl HasSource for Trait {
-    type Ast = ast::TraitDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::TraitDef> {
+    type Ast = ast::Trait;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Trait> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 impl HasSource for TypeAlias {
-    type Ast = ast::TypeAliasDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::TypeAliasDef> {
+    type Ast = ast::TypeAlias;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::TypeAlias> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
@@ -120,14 +120,14 @@ impl HasSource for MacroDef {
     }
 }
 impl HasSource for ImplDef {
-    type Ast = ast::ImplDef;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::ImplDef> {
+    type Ast = ast::Impl;
+    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Impl> {
         self.id.lookup(db.upcast()).source(db.upcast())
     }
 }
 
 impl HasSource for TypeParam {
-    type Ast = Either<ast::TraitDef, ast::TypeParam>;
+    type Ast = Either<ast::Trait, ast::TypeParam>;
     fn source(self, db: &dyn HirDatabase) -> InFile<Self::Ast> {
         let child_source = self.id.parent.child_source(db.upcast());
         child_source.map(|it| it[self.id.local_id].clone())
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index fe34b30bc..e2d13dbfd 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -19,25 +19,6 @@
 
 #![recursion_limit = "512"]
 
-macro_rules! impl_froms {
-    ($e:ident: $($v:ident $(($($sv:ident),*))?),*$(,)?) => {
-        $(
-            impl From<$v> for $e {
-                fn from(it: $v) -> $e {
-                    $e::$v(it)
-                }
-            }
-            $($(
-                impl From<$sv> for $e {
-                    fn from(it: $sv) -> $e {
-                        $e::$v($v::$sv(it))
-                    }
-                }
-            )*)?
-        )*
-    }
-}
-
 mod semantics;
 pub mod db;
 mod source_analyzer;
@@ -51,10 +32,10 @@ mod has_source;
 
 pub use crate::{
     code_model::{
-        Adt, AsAssocItem, AssocItem, AssocItemContainer, AttrDef, Const, Crate, CrateDependency,
-        DefWithBody, Docs, Enum, EnumVariant, Field, FieldSource, Function, GenericDef, HasAttrs,
-        HasVisibility, ImplDef, Local, MacroDef, Module, ModuleDef, ScopeDef, Static, Struct,
-        Trait, Type, TypeAlias, TypeParam, Union, VariantDef, Visibility,
+        Adt, AsAssocItem, AssocItem, AssocItemContainer, AttrDef, Callable, CallableKind, Const,
+        Crate, CrateDependency, DefWithBody, Docs, Enum, EnumVariant, Field, FieldSource, Function,
+        GenericDef, HasAttrs, HasVisibility, ImplDef, Local, MacroDef, Module, ModuleDef, ScopeDef,
+        Static, Struct, Trait, Type, TypeAlias, TypeParam, Union, VariantDef, Visibility,
     },
     has_source::HasSource,
     semantics::{original_range, PathResolution, Semantics, SemanticsScope},
@@ -74,6 +55,7 @@ pub use hir_def::{
 pub use hir_expand::{
     hygiene::Hygiene,
     name::{AsName, Name},
-    HirFileId, InFile, MacroCallId, MacroCallLoc, MacroDefId, MacroFile, Origin,
+    HirFileId, InFile, MacroCallId, MacroCallLoc, MacroDefId, /* FIXME */
+    MacroFile, Origin,
 };
-pub use hir_ty::{display::HirDisplay, CallableDef};
+pub use hir_ty::display::HirDisplay;
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 6a49c424a..6f3b3dc9a 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -6,7 +6,7 @@ use std::{cell::RefCell, fmt, iter::successors};
 
 use hir_def::{
     resolver::{self, HasResolver, Resolver},
-    AsMacroCall, TraitId, VariantId,
+    AsMacroCall, FunctionId, TraitId, VariantId,
 };
 use hir_expand::{diagnostics::AstDiagnostic, hygiene::Hygiene, ExpansionInfo};
 use hir_ty::associated_type_shorthand_candidates;
@@ -24,8 +24,8 @@ use crate::{
     diagnostics::Diagnostic,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
-    AssocItem, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef, Module, ModuleDef,
-    Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam,
+    AssocItem, Callable, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef, Module,
+    ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, VariantDef,
 };
 use resolver::TypeNs;
 
@@ -83,7 +83,13 @@ impl PathResolution {
 /// Primary API to get semantic information, like types, from syntax trees.
 pub struct Semantics<'db, DB> {
     pub db: &'db DB,
+    imp: SemanticsImpl<'db>,
+}
+
+pub struct SemanticsImpl<'db> {
+    pub db: &'db dyn HirDatabase,
     s2d_cache: RefCell<SourceToDefCache>,
+    expansion_info_cache: RefCell<FxHashMap<HirFileId, Option<ExpansionInfo>>>,
     cache: RefCell<FxHashMap<SyntaxNode, HirFileId>>,
 }
 
@@ -95,23 +101,199 @@ impl<DB> fmt::Debug for Semantics<'_, DB> {
 
 impl<'db, DB: HirDatabase> Semantics<'db, DB> {
     pub fn new(db: &DB) -> Semantics<DB> {
-        Semantics { db, s2d_cache: Default::default(), cache: Default::default() }
+        let impl_ = SemanticsImpl::new(db);
+        Semantics { db, imp: impl_ }
     }
 
     pub fn parse(&self, file_id: FileId) -> ast::SourceFile {
-        let tree = self.db.parse(file_id).tree();
-        self.cache(tree.syntax().clone(), file_id.into());
-        tree
+        self.imp.parse(file_id)
     }
 
     pub fn ast<T: AstDiagnostic + Diagnostic>(&self, d: &T) -> <T as AstDiagnostic>::AST {
         let file_id = d.source().file_id;
         let root = self.db.parse_or_expand(file_id).unwrap();
-        self.cache(root, file_id);
-        d.ast(self.db)
+        self.imp.cache(root, file_id);
+        d.ast(self.db.upcast())
     }
 
     pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
+        self.imp.expand(macro_call)
+    }
+
+    pub fn expand_hypothetical(
+        &self,
+        actual_macro_call: &ast::MacroCall,
+        hypothetical_args: &ast::TokenTree,
+        token_to_map: SyntaxToken,
+    ) -> Option<(SyntaxNode, SyntaxToken)> {
+        self.imp.expand_hypothetical(actual_macro_call, hypothetical_args, token_to_map)
+    }
+
+    pub fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
+        self.imp.descend_into_macros(token)
+    }
+
+    pub fn descend_node_at_offset<N: ast::AstNode>(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> Option<N> {
+        self.imp.descend_node_at_offset(node, offset).find_map(N::cast)
+    }
+
+    pub fn original_range(&self, node: &SyntaxNode) -> FileRange {
+        self.imp.original_range(node)
+    }
+
+    pub fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
+        self.imp.diagnostics_range(diagnostics)
+    }
+
+    pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
+        self.imp.ancestors_with_macros(node)
+    }
+
+    pub fn ancestors_at_offset_with_macros(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> impl Iterator<Item = SyntaxNode> + '_ {
+        self.imp.ancestors_at_offset_with_macros(node, offset)
+    }
+
+    /// Find a AstNode by offset inside SyntaxNode, if it is inside *Macrofile*,
+    /// search up until it is of the target AstNode type
+    pub fn find_node_at_offset_with_macros<N: AstNode>(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> Option<N> {
+        self.imp.ancestors_at_offset_with_macros(node, offset).find_map(N::cast)
+    }
+
+    /// Find a AstNode by offset inside SyntaxNode, if it is inside *MacroCall*,
+    /// descend it and find again
+    pub fn find_node_at_offset_with_descend<N: AstNode>(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> Option<N> {
+        if let Some(it) = find_node_at_offset(&node, offset) {
+            return Some(it);
+        }
+
+        self.imp.descend_node_at_offset(node, offset).find_map(N::cast)
+    }
+
+    pub fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
+        self.imp.type_of_expr(expr)
+    }
+
+    pub fn type_of_pat(&self, pat: &ast::Pat) -> Option<Type> {
+        self.imp.type_of_pat(pat)
+    }
+
+    pub fn type_of_self(&self, param: &ast::SelfParam) -> Option<Type> {
+        self.imp.type_of_self(param)
+    }
+
+    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
+        self.imp.resolve_method_call(call).map(Function::from)
+    }
+
+    pub fn resolve_method_call_as_callable(&self, call: &ast::MethodCallExpr) -> Option<Callable> {
+        self.imp.resolve_method_call_as_callable(call)
+    }
+
+    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<Field> {
+        self.imp.resolve_field(field)
+    }
+
+    pub fn resolve_record_field(
+        &self,
+        field: &ast::RecordExprField,
+    ) -> Option<(Field, Option<Local>)> {
+        self.imp.resolve_record_field(field)
+    }
+
+    pub fn resolve_record_field_pat(&self, field: &ast::RecordFieldPat) -> Option<Field> {
+        self.imp.resolve_record_field_pat(field)
+    }
+
+    pub fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
+        self.imp.resolve_macro_call(macro_call)
+    }
+
+    pub fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
+        self.imp.resolve_path(path)
+    }
+
+    pub fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantDef> {
+        self.imp.resolve_variant(record_lit).map(VariantDef::from)
+    }
+
+    pub fn lower_path(&self, path: &ast::Path) -> Option<Path> {
+        self.imp.lower_path(path)
+    }
+
+    pub fn resolve_bind_pat_to_const(&self, pat: &ast::BindPat) -> Option<ModuleDef> {
+        self.imp.resolve_bind_pat_to_const(pat)
+    }
+
+    // FIXME: use this instead?
+    // pub fn resolve_name_ref(&self, name_ref: &ast::NameRef) -> Option<???>;
+
+    pub fn record_literal_missing_fields(&self, literal: &ast::RecordExpr) -> Vec<(Field, Type)> {
+        self.imp.record_literal_missing_fields(literal)
+    }
+
+    pub fn record_pattern_missing_fields(&self, pattern: &ast::RecordPat) -> Vec<(Field, Type)> {
+        self.imp.record_pattern_missing_fields(pattern)
+    }
+
+    pub fn to_def<T: ToDef>(&self, src: &T) -> Option<T::Def> {
+        let src = self.imp.find_file(src.syntax().clone()).with_value(src).cloned();
+        T::to_def(&self.imp, src)
+    }
+
+    pub fn to_module_def(&self, file: FileId) -> Option<Module> {
+        self.imp.to_module_def(file)
+    }
+
+    pub fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db> {
+        self.imp.scope(node)
+    }
+
+    pub fn scope_at_offset(&self, node: &SyntaxNode, offset: TextSize) -> SemanticsScope<'db> {
+        self.imp.scope_at_offset(node, offset)
+    }
+
+    pub fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db> {
+        self.imp.scope_for_def(def)
+    }
+
+    pub fn assert_contains_node(&self, node: &SyntaxNode) {
+        self.imp.assert_contains_node(node)
+    }
+}
+
+impl<'db> SemanticsImpl<'db> {
+    fn new(db: &'db dyn HirDatabase) -> Self {
+        SemanticsImpl {
+            db,
+            s2d_cache: Default::default(),
+            cache: Default::default(),
+            expansion_info_cache: Default::default(),
+        }
+    }
+
+    fn parse(&self, file_id: FileId) -> ast::SourceFile {
+        let tree = self.db.parse(file_id).tree();
+        self.cache(tree.syntax().clone(), file_id.into());
+        tree
+    }
+
+    fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
         let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
         let sa = self.analyze2(macro_call.map(|it| it.syntax()), None);
         let file_id = sa.expand(self.db, macro_call)?;
@@ -120,7 +302,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         Some(node)
     }
 
-    pub fn expand_hypothetical(
+    fn expand_hypothetical(
         &self,
         actual_macro_call: &ast::MacroCall,
         hypothetical_args: &ast::TokenTree,
@@ -130,24 +312,38 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
             self.find_file(actual_macro_call.syntax().clone()).with_value(actual_macro_call);
         let sa = self.analyze2(macro_call.map(|it| it.syntax()), None);
         let krate = sa.resolver.krate()?;
-        let macro_call_id = macro_call
-            .as_call_id(self.db, krate, |path| sa.resolver.resolve_path_as_macro(self.db, &path))?;
-        hir_expand::db::expand_hypothetical(self.db, macro_call_id, hypothetical_args, token_to_map)
-    }
-
-    pub fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
+        let macro_call_id = macro_call.as_call_id(self.db.upcast(), krate, |path| {
+            sa.resolver.resolve_path_as_macro(self.db.upcast(), &path)
+        })?;
+        hir_expand::db::expand_hypothetical(
+            self.db.upcast(),
+            macro_call_id,
+            hypothetical_args,
+            token_to_map,
+        )
+    }
+
+    fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
+        let _p = profile("descend_into_macros");
         let parent = token.parent();
         let parent = self.find_file(parent);
         let sa = self.analyze2(parent.as_ref(), None);
 
         let token = successors(Some(parent.with_value(token)), |token| {
+            self.db.check_canceled();
             let macro_call = token.value.ancestors().find_map(ast::MacroCall::cast)?;
             let tt = macro_call.token_tree()?;
             if !tt.syntax().text_range().contains_range(token.value.text_range()) {
                 return None;
             }
             let file_id = sa.expand(self.db, token.with_value(&macro_call))?;
-            let token = file_id.expansion_info(self.db)?.map_token_down(token.as_ref())?;
+            let token = self
+                .expansion_info_cache
+                .borrow_mut()
+                .entry(file_id)
+                .or_insert_with(|| file_id.expansion_info(self.db.upcast()))
+                .as_ref()?
+                .map_token_down(token.as_ref())?;
 
             self.cache(find_root(&token.value.parent()), token.file_id);
 
@@ -159,35 +355,36 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         token.value
     }
 
-    pub fn descend_node_at_offset<N: ast::AstNode>(
+    fn descend_node_at_offset(
         &self,
         node: &SyntaxNode,
         offset: TextSize,
-    ) -> Option<N> {
+    ) -> impl Iterator<Item = SyntaxNode> + '_ {
         // Handle macro token cases
         node.token_at_offset(offset)
             .map(|token| self.descend_into_macros(token))
-            .find_map(|it| self.ancestors_with_macros(it.parent()).find_map(N::cast))
+            .map(|it| self.ancestors_with_macros(it.parent()))
+            .flatten()
     }
 
-    pub fn original_range(&self, node: &SyntaxNode) -> FileRange {
+    fn original_range(&self, node: &SyntaxNode) -> FileRange {
         let node = self.find_file(node.clone());
         original_range(self.db, node.as_ref())
     }
 
-    pub fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
+    fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
         let src = diagnostics.source();
         let root = self.db.parse_or_expand(src.file_id).unwrap();
         let node = src.value.to_node(&root);
         original_range(self.db, src.with_value(&node))
     }
 
-    pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
+    fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
         let node = self.find_file(node);
-        node.ancestors_with_macros(self.db).map(|it| it.value)
+        node.ancestors_with_macros(self.db.upcast()).map(|it| it.value)
     }
 
-    pub fn ancestors_at_offset_with_macros(
+    fn ancestors_at_offset_with_macros(
         &self,
         node: &SyntaxNode,
         offset: TextSize,
@@ -197,120 +394,104 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
             .kmerge_by(|node1, node2| node1.text_range().len() < node2.text_range().len())
     }
 
-    /// Find a AstNode by offset inside SyntaxNode, if it is inside *Macrofile*,
-    /// search up until it is of the target AstNode type
-    pub fn find_node_at_offset_with_macros<N: AstNode>(
-        &self,
-        node: &SyntaxNode,
-        offset: TextSize,
-    ) -> Option<N> {
-        self.ancestors_at_offset_with_macros(node, offset).find_map(N::cast)
+    fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
+        self.analyze(expr.syntax()).type_of_expr(self.db, &expr)
     }
 
-    /// Find a AstNode by offset inside SyntaxNode, if it is inside *MacroCall*,
-    /// descend it and find again
-    pub fn find_node_at_offset_with_descend<N: AstNode>(
-        &self,
-        node: &SyntaxNode,
-        offset: TextSize,
-    ) -> Option<N> {
-        if let Some(it) = find_node_at_offset(&node, offset) {
-            return Some(it);
-        }
-        self.descend_node_at_offset(&node, offset)
+    fn type_of_pat(&self, pat: &ast::Pat) -> Option<Type> {
+        self.analyze(pat.syntax()).type_of_pat(self.db, &pat)
     }
 
-    pub fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
-        self.analyze(expr.syntax()).type_of(self.db, &expr)
+    fn type_of_self(&self, param: &ast::SelfParam) -> Option<Type> {
+        self.analyze(param.syntax()).type_of_self(self.db, &param)
     }
 
-    pub fn type_of_pat(&self, pat: &ast::Pat) -> Option<Type> {
-        self.analyze(pat.syntax()).type_of_pat(self.db, &pat)
+    fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<FunctionId> {
+        self.analyze(call.syntax()).resolve_method_call(self.db, call)
     }
 
-    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
-        self.analyze(call.syntax()).resolve_method_call(self.db, call)
+    fn resolve_method_call_as_callable(&self, call: &ast::MethodCallExpr) -> Option<Callable> {
+        // FIXME: this erases Substs
+        let func = self.resolve_method_call(call)?;
+        let ty = self.db.value_ty(func.into());
+        let resolver = self.analyze(call.syntax()).resolver;
+        let ty = Type::new_with_resolver(self.db, &resolver, ty.value)?;
+        let mut res = ty.as_callable(self.db)?;
+        res.is_bound_method = true;
+        Some(res)
     }
 
-    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<Field> {
+    fn resolve_field(&self, field: &ast::FieldExpr) -> Option<Field> {
         self.analyze(field.syntax()).resolve_field(self.db, field)
     }
 
-    pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<(Field, Option<Local>)> {
+    fn resolve_record_field(&self, field: &ast::RecordExprField) -> Option<(Field, Option<Local>)> {
         self.analyze(field.syntax()).resolve_record_field(self.db, field)
     }
 
-    pub fn resolve_record_field_pat(&self, field: &ast::RecordFieldPat) -> Option<Field> {
+    fn resolve_record_field_pat(&self, field: &ast::RecordFieldPat) -> Option<Field> {
         self.analyze(field.syntax()).resolve_record_field_pat(self.db, field)
     }
 
-    pub fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
+    fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
         let sa = self.analyze(macro_call.syntax());
         let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
         sa.resolve_macro_call(self.db, macro_call)
     }
 
-    pub fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
+    fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
         self.analyze(path.syntax()).resolve_path(self.db, path)
     }
 
-    pub fn resolve_variant(&self, record_lit: ast::RecordLit) -> Option<VariantId> {
+    fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantId> {
         self.analyze(record_lit.syntax()).resolve_variant(self.db, record_lit)
     }
 
-    pub fn lower_path(&self, path: &ast::Path) -> Option<Path> {
+    fn lower_path(&self, path: &ast::Path) -> Option<Path> {
         let src = self.find_file(path.syntax().clone());
         Path::from_src(path.clone(), &Hygiene::new(self.db.upcast(), src.file_id.into()))
     }
 
-    pub fn resolve_bind_pat_to_const(&self, pat: &ast::BindPat) -> Option<ModuleDef> {
+    fn resolve_bind_pat_to_const(&self, pat: &ast::BindPat) -> Option<ModuleDef> {
         self.analyze(pat.syntax()).resolve_bind_pat_to_const(self.db, pat)
     }
 
-    // FIXME: use this instead?
-    // pub fn resolve_name_ref(&self, name_ref: &ast::NameRef) -> Option<???>;
-
-    pub fn record_literal_missing_fields(&self, literal: &ast::RecordLit) -> Vec<(Field, Type)> {
+    fn record_literal_missing_fields(&self, literal: &ast::RecordExpr) -> Vec<(Field, Type)> {
         self.analyze(literal.syntax())
             .record_literal_missing_fields(self.db, literal)
             .unwrap_or_default()
     }
 
-    pub fn record_pattern_missing_fields(&self, pattern: &ast::RecordPat) -> Vec<(Field, Type)> {
+    fn record_pattern_missing_fields(&self, pattern: &ast::RecordPat) -> Vec<(Field, Type)> {
         self.analyze(pattern.syntax())
             .record_pattern_missing_fields(self.db, pattern)
             .unwrap_or_default()
     }
 
-    pub fn to_def<T: ToDef>(&self, src: &T) -> Option<T::Def> {
-        let src = self.find_file(src.syntax().clone()).with_value(src).cloned();
-        T::to_def(self, src)
-    }
-
     fn with_ctx<F: FnOnce(&mut SourceToDefCtx) -> T, T>(&self, f: F) -> T {
         let mut cache = self.s2d_cache.borrow_mut();
         let mut ctx = SourceToDefCtx { db: self.db, cache: &mut *cache };
         f(&mut ctx)
     }
 
-    pub fn to_module_def(&self, file: FileId) -> Option<Module> {
+    fn to_module_def(&self, file: FileId) -> Option<Module> {
         self.with_ctx(|ctx| ctx.file_to_def(file)).map(Module::from)
     }
 
-    pub fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db, DB> {
+    fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db> {
         let node = self.find_file(node.clone());
         let resolver = self.analyze2(node.as_ref(), None).resolver;
         SemanticsScope { db: self.db, resolver }
     }
 
-    pub fn scope_at_offset(&self, node: &SyntaxNode, offset: TextSize) -> SemanticsScope<'db, DB> {
+    fn scope_at_offset(&self, node: &SyntaxNode, offset: TextSize) -> SemanticsScope<'db> {
         let node = self.find_file(node.clone());
         let resolver = self.analyze2(node.as_ref(), Some(offset)).resolver;
         SemanticsScope { db: self.db, resolver }
     }
 
-    pub fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db, DB> {
-        let resolver = def.id.resolver(self.db);
+    fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db> {
+        let resolver = def.id.resolver(self.db.upcast());
         SemanticsScope { db: self.db, resolver }
     }
 
@@ -331,12 +512,13 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
             ChildContainer::DefWithBodyId(def) => {
                 return SourceAnalyzer::new_for_body(self.db, def, src, offset)
             }
-            ChildContainer::TraitId(it) => it.resolver(self.db),
-            ChildContainer::ImplId(it) => it.resolver(self.db),
-            ChildContainer::ModuleId(it) => it.resolver(self.db),
-            ChildContainer::EnumId(it) => it.resolver(self.db),
-            ChildContainer::VariantId(it) => it.resolver(self.db),
-            ChildContainer::GenericDefId(it) => it.resolver(self.db),
+            ChildContainer::TraitId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::ImplId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::ModuleId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::EnumId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::VariantId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::TypeAliasId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::GenericDefId(it) => it.resolver(self.db.upcast()),
         };
         SourceAnalyzer::new_for_resolver(resolver, src)
     }
@@ -348,7 +530,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         assert!(prev == None || prev == Some(file_id))
     }
 
-    pub fn assert_contains_node(&self, node: &SyntaxNode) {
+    fn assert_contains_node(&self, node: &SyntaxNode) {
         self.find_file(node.clone());
     }
 
@@ -382,14 +564,14 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
 pub trait ToDef: AstNode + Clone {
     type Def;
 
-    fn to_def<DB: HirDatabase>(sema: &Semantics<DB>, src: InFile<Self>) -> Option<Self::Def>;
+    fn to_def(sema: &SemanticsImpl, src: InFile<Self>) -> Option<Self::Def>;
 }
 
 macro_rules! to_def_impls {
     ($(($def:path, $ast:path, $meth:ident)),* ,) => {$(
         impl ToDef for $ast {
             type Def = $def;
-            fn to_def<DB: HirDatabase>(sema: &Semantics<DB>, src: InFile<Self>) -> Option<Self::Def> {
+            fn to_def(sema: &SemanticsImpl, src: InFile<Self>) -> Option<Self::Def> {
                 sema.with_ctx(|ctx| ctx.$meth(src)).map(<$def>::from)
             }
         }
@@ -398,18 +580,18 @@ macro_rules! to_def_impls {
 
 to_def_impls![
     (crate::Module, ast::Module, module_to_def),
-    (crate::Struct, ast::StructDef, struct_to_def),
-    (crate::Enum, ast::EnumDef, enum_to_def),
-    (crate::Union, ast::UnionDef, union_to_def),
-    (crate::Trait, ast::TraitDef, trait_to_def),
-    (crate::ImplDef, ast::ImplDef, impl_to_def),
-    (crate::TypeAlias, ast::TypeAliasDef, type_alias_to_def),
-    (crate::Const, ast::ConstDef, const_to_def),
-    (crate::Static, ast::StaticDef, static_to_def),
-    (crate::Function, ast::FnDef, fn_to_def),
-    (crate::Field, ast::RecordFieldDef, record_field_to_def),
-    (crate::Field, ast::TupleFieldDef, tuple_field_to_def),
-    (crate::EnumVariant, ast::EnumVariant, enum_variant_to_def),
+    (crate::Struct, ast::Struct, struct_to_def),
+    (crate::Enum, ast::Enum, enum_to_def),
+    (crate::Union, ast::Union, union_to_def),
+    (crate::Trait, ast::Trait, trait_to_def),
+    (crate::ImplDef, ast::Impl, impl_to_def),
+    (crate::TypeAlias, ast::TypeAlias, type_alias_to_def),
+    (crate::Const, ast::Const, const_to_def),
+    (crate::Static, ast::Static, static_to_def),
+    (crate::Function, ast::Fn, fn_to_def),
+    (crate::Field, ast::RecordField, record_field_to_def),
+    (crate::Field, ast::TupleField, tuple_field_to_def),
+    (crate::EnumVariant, ast::Variant, enum_variant_to_def),
     (crate::TypeParam, ast::TypeParam, type_param_to_def),
     (crate::MacroDef, ast::MacroCall, macro_call_to_def), // this one is dubious, not all calls are macros
     (crate::Local, ast::BindPat, bind_pat_to_def),
@@ -419,12 +601,13 @@ fn find_root(node: &SyntaxNode) -> SyntaxNode {
     node.ancestors().last().unwrap()
 }
 
-pub struct SemanticsScope<'a, DB> {
-    pub db: &'a DB,
+#[derive(Debug)]
+pub struct SemanticsScope<'a> {
+    pub db: &'a dyn HirDatabase,
     resolver: Resolver,
 }
 
-impl<'a, DB: HirDatabase> SemanticsScope<'a, DB> {
+impl<'a> SemanticsScope<'a> {
     pub fn module(&self) -> Option<Module> {
         Some(Module { id: self.resolver.module()? })
     }
@@ -433,13 +616,13 @@ impl<'a, DB: HirDatabase> SemanticsScope<'a, DB> {
     // FIXME: rename to visible_traits to not repeat scope?
     pub fn traits_in_scope(&self) -> FxHashSet<TraitId> {
         let resolver = &self.resolver;
-        resolver.traits_in_scope(self.db)
+        resolver.traits_in_scope(self.db.upcast())
     }
 
     pub fn process_all_names(&self, f: &mut dyn FnMut(Name, ScopeDef)) {
         let resolver = &self.resolver;
 
-        resolver.process_all_names(self.db, &mut |name, def| {
+        resolver.process_all_names(self.db.upcast(), &mut |name, def| {
             let def = match def {
                 resolver::ScopeDef::PerNs(it) => {
                     let items = ScopeDef::all_items(it);
diff --git a/crates/ra_hir/src/semantics/source_to_def.rs b/crates/ra_hir/src/semantics/source_to_def.rs
index 8af64fdc1..d1994e2e7 100644
--- a/crates/ra_hir/src/semantics/source_to_def.rs
+++ b/crates/ra_hir/src/semantics/source_to_def.rs
@@ -16,6 +16,7 @@ use ra_syntax::{
     match_ast, AstNode, SyntaxNode,
 };
 use rustc_hash::FxHashMap;
+use stdx::impl_from;
 
 use crate::{db::HirDatabase, InFile, MacroDefId};
 
@@ -64,53 +65,44 @@ impl SourceToDefCtx<'_, '_> {
         Some(ModuleId { krate: parent_module.krate, local_id: child_id })
     }
 
-    pub(super) fn trait_to_def(&mut self, src: InFile<ast::TraitDef>) -> Option<TraitId> {
+    pub(super) fn trait_to_def(&mut self, src: InFile<ast::Trait>) -> Option<TraitId> {
         self.to_def(src, keys::TRAIT)
     }
-    pub(super) fn impl_to_def(&mut self, src: InFile<ast::ImplDef>) -> Option<ImplId> {
+    pub(super) fn impl_to_def(&mut self, src: InFile<ast::Impl>) -> Option<ImplId> {
         self.to_def(src, keys::IMPL)
     }
-    pub(super) fn fn_to_def(&mut self, src: InFile<ast::FnDef>) -> Option<FunctionId> {
+    pub(super) fn fn_to_def(&mut self, src: InFile<ast::Fn>) -> Option<FunctionId> {
         self.to_def(src, keys::FUNCTION)
     }
-    pub(super) fn struct_to_def(&mut self, src: InFile<ast::StructDef>) -> Option<StructId> {
+    pub(super) fn struct_to_def(&mut self, src: InFile<ast::Struct>) -> Option<StructId> {
         self.to_def(src, keys::STRUCT)
     }
-    pub(super) fn enum_to_def(&mut self, src: InFile<ast::EnumDef>) -> Option<EnumId> {
+    pub(super) fn enum_to_def(&mut self, src: InFile<ast::Enum>) -> Option<EnumId> {
         self.to_def(src, keys::ENUM)
     }
-    pub(super) fn union_to_def(&mut self, src: InFile<ast::UnionDef>) -> Option<UnionId> {
+    pub(super) fn union_to_def(&mut self, src: InFile<ast::Union>) -> Option<UnionId> {
         self.to_def(src, keys::UNION)
     }
-    pub(super) fn static_to_def(&mut self, src: InFile<ast::StaticDef>) -> Option<StaticId> {
+    pub(super) fn static_to_def(&mut self, src: InFile<ast::Static>) -> Option<StaticId> {
         self.to_def(src, keys::STATIC)
     }
-    pub(super) fn const_to_def(&mut self, src: InFile<ast::ConstDef>) -> Option<ConstId> {
+    pub(super) fn const_to_def(&mut self, src: InFile<ast::Const>) -> Option<ConstId> {
         self.to_def(src, keys::CONST)
     }
-    pub(super) fn type_alias_to_def(
-        &mut self,
-        src: InFile<ast::TypeAliasDef>,
-    ) -> Option<TypeAliasId> {
+    pub(super) fn type_alias_to_def(&mut self, src: InFile<ast::TypeAlias>) -> Option<TypeAliasId> {
         self.to_def(src, keys::TYPE_ALIAS)
     }
-    pub(super) fn record_field_to_def(
-        &mut self,
-        src: InFile<ast::RecordFieldDef>,
-    ) -> Option<FieldId> {
+    pub(super) fn record_field_to_def(&mut self, src: InFile<ast::RecordField>) -> Option<FieldId> {
         self.to_def(src, keys::RECORD_FIELD)
     }
-    pub(super) fn tuple_field_to_def(
-        &mut self,
-        src: InFile<ast::TupleFieldDef>,
-    ) -> Option<FieldId> {
+    pub(super) fn tuple_field_to_def(&mut self, src: InFile<ast::TupleField>) -> Option<FieldId> {
         self.to_def(src, keys::TUPLE_FIELD)
     }
     pub(super) fn enum_variant_to_def(
         &mut self,
-        src: InFile<ast::EnumVariant>,
+        src: InFile<ast::Variant>,
     ) -> Option<EnumVariantId> {
-        self.to_def(src, keys::ENUM_VARIANT)
+        self.to_def(src, keys::VARIANT)
     }
     pub(super) fn bind_pat_to_def(
         &mut self,
@@ -162,38 +154,42 @@ impl SourceToDefCtx<'_, '_> {
                         let def = self.module_to_def(container.with_value(it))?;
                         def.into()
                     },
-                    ast::TraitDef(it) => {
+                    ast::Trait(it) => {
                         let def = self.trait_to_def(container.with_value(it))?;
                         def.into()
                     },
-                    ast::ImplDef(it) => {
+                    ast::Impl(it) => {
                         let def = self.impl_to_def(container.with_value(it))?;
                         def.into()
                     },
-                    ast::FnDef(it) => {
+                    ast::Fn(it) => {
                         let def = self.fn_to_def(container.with_value(it))?;
                         DefWithBodyId::from(def).into()
                     },
-                    ast::StructDef(it) => {
+                    ast::Struct(it) => {
                         let def = self.struct_to_def(container.with_value(it))?;
                         VariantId::from(def).into()
                     },
-                    ast::EnumDef(it) => {
+                    ast::Enum(it) => {
                         let def = self.enum_to_def(container.with_value(it))?;
                         def.into()
                     },
-                    ast::UnionDef(it) => {
+                    ast::Union(it) => {
                         let def = self.union_to_def(container.with_value(it))?;
                         VariantId::from(def).into()
                     },
-                    ast::StaticDef(it) => {
+                    ast::Static(it) => {
                         let def = self.static_to_def(container.with_value(it))?;
                         DefWithBodyId::from(def).into()
                     },
-                    ast::ConstDef(it) => {
+                    ast::Const(it) => {
                         let def = self.const_to_def(container.with_value(it))?;
                         DefWithBodyId::from(def).into()
                     },
+                    ast::TypeAlias(it) => {
+                        let def = self.type_alias_to_def(container.with_value(it))?;
+                        def.into()
+                    },
                     _ => continue,
                 }
             };
@@ -208,12 +204,12 @@ impl SourceToDefCtx<'_, '_> {
         for container in src.cloned().ancestors_with_macros(self.db.upcast()).skip(1) {
             let res: GenericDefId = match_ast! {
                 match (container.value) {
-                    ast::FnDef(it) => self.fn_to_def(container.with_value(it))?.into(),
-                    ast::StructDef(it) => self.struct_to_def(container.with_value(it))?.into(),
-                    ast::EnumDef(it) => self.enum_to_def(container.with_value(it))?.into(),
-                    ast::TraitDef(it) => self.trait_to_def(container.with_value(it))?.into(),
-                    ast::TypeAliasDef(it) => self.type_alias_to_def(container.with_value(it))?.into(),
-                    ast::ImplDef(it) => self.impl_to_def(container.with_value(it))?.into(),
+                    ast::Fn(it) => self.fn_to_def(container.with_value(it))?.into(),
+                    ast::Struct(it) => self.struct_to_def(container.with_value(it))?.into(),
+                    ast::Enum(it) => self.enum_to_def(container.with_value(it))?.into(),
+                    ast::Trait(it) => self.trait_to_def(container.with_value(it))?.into(),
+                    ast::TypeAlias(it) => self.type_alias_to_def(container.with_value(it))?.into(),
+                    ast::Impl(it) => self.impl_to_def(container.with_value(it))?.into(),
                     _ => continue,
                 }
             };
@@ -226,9 +222,9 @@ impl SourceToDefCtx<'_, '_> {
         for container in src.cloned().ancestors_with_macros(self.db.upcast()).skip(1) {
             let res: DefWithBodyId = match_ast! {
                 match (container.value) {
-                    ast::ConstDef(it) => self.const_to_def(container.with_value(it))?.into(),
-                    ast::StaticDef(it) => self.static_to_def(container.with_value(it))?.into(),
-                    ast::FnDef(it) => self.fn_to_def(container.with_value(it))?.into(),
+                    ast::Const(it) => self.const_to_def(container.with_value(it))?.into(),
+                    ast::Static(it) => self.static_to_def(container.with_value(it))?.into(),
+                    ast::Fn(it) => self.fn_to_def(container.with_value(it))?.into(),
                     _ => continue,
                 }
             };
@@ -246,19 +242,21 @@ pub(crate) enum ChildContainer {
     ImplId(ImplId),
     EnumId(EnumId),
     VariantId(VariantId),
+    TypeAliasId(TypeAliasId),
     /// XXX: this might be the same def as, for example an `EnumId`. However,
     /// here the children generic parameters, and not, eg enum variants.
     GenericDefId(GenericDefId),
 }
-impl_froms! {
-    ChildContainer:
+impl_from! {
     DefWithBodyId,
     ModuleId,
     TraitId,
     ImplId,
     EnumId,
     VariantId,
+    TypeAliasId,
     GenericDefId
+    for ChildContainer
 }
 
 impl ChildContainer {
@@ -271,6 +269,7 @@ impl ChildContainer {
             ChildContainer::ImplId(it) => it.child_by_source(db),
             ChildContainer::EnumId(it) => it.child_by_source(db),
             ChildContainer::VariantId(it) => it.child_by_source(db),
+            ChildContainer::TypeAliasId(_) => DynMap::default(),
             ChildContainer::GenericDefId(it) => it.child_by_source(db),
         }
     }
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index 1d6c47103..f2e630ef1 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -14,11 +14,11 @@ use hir_def::{
     },
     expr::{ExprId, Pat, PatId},
     resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs},
-    AsMacroCall, DefWithBodyId, FieldId, LocalFieldId, VariantId,
+    AsMacroCall, DefWithBodyId, FieldId, FunctionId, LocalFieldId, VariantId,
 };
 use hir_expand::{hygiene::Hygiene, name::AsName, HirFileId, InFile};
 use hir_ty::{
-    expr::{record_literal_missing_fields, record_pattern_missing_fields},
+    diagnostics::{record_literal_missing_fields, record_pattern_missing_fields},
     InferenceResult, Substs, Ty,
 };
 use ra_syntax::{
@@ -115,7 +115,7 @@ impl SourceAnalyzer {
         Some(res)
     }
 
-    pub(crate) fn type_of(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<Type> {
+    pub(crate) fn type_of_expr(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<Type> {
         let expr_id = self.expr_id(db, expr)?;
         let ty = self.infer.as_ref()?[expr_id].clone();
         Type::new_with_resolver(db, &self.resolver, ty)
@@ -127,13 +127,24 @@ impl SourceAnalyzer {
         Type::new_with_resolver(db, &self.resolver, ty)
     }
 
+    pub(crate) fn type_of_self(
+        &self,
+        db: &dyn HirDatabase,
+        param: &ast::SelfParam,
+    ) -> Option<Type> {
+        let src = InFile { file_id: self.file_id, value: param };
+        let pat_id = self.body_source_map.as_ref()?.node_self_param(src)?;
+        let ty = self.infer.as_ref()?[pat_id].clone();
+        Type::new_with_resolver(db, &self.resolver, ty)
+    }
+
     pub(crate) fn resolve_method_call(
         &self,
         db: &dyn HirDatabase,
         call: &ast::MethodCallExpr,
-    ) -> Option<Function> {
+    ) -> Option<FunctionId> {
         let expr_id = self.expr_id(db, &call.clone().into())?;
-        self.infer.as_ref()?.method_resolution(expr_id).map(Function::from)
+        self.infer.as_ref()?.method_resolution(expr_id)
     }
 
     pub(crate) fn resolve_field(
@@ -148,7 +159,7 @@ impl SourceAnalyzer {
     pub(crate) fn resolve_record_field(
         &self,
         db: &dyn HirDatabase,
-        field: &ast::RecordField,
+        field: &ast::RecordExprField,
     ) -> Option<(Field, Option<Local>)> {
         let expr = field.expr()?;
         let expr_id = self.expr_id(db, &expr)?;
@@ -235,7 +246,7 @@ impl SourceAnalyzer {
             }
         }
 
-        if let Some(rec_lit) = path.syntax().parent().and_then(ast::RecordLit::cast) {
+        if let Some(rec_lit) = path.syntax().parent().and_then(ast::RecordExpr::cast) {
             let expr_id = self.expr_id(db, &rec_lit.into())?;
             if let Some(VariantId::EnumVariantId(variant)) =
                 self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
@@ -273,7 +284,7 @@ impl SourceAnalyzer {
     pub(crate) fn record_literal_missing_fields(
         &self,
         db: &dyn HirDatabase,
-        literal: &ast::RecordLit,
+        literal: &ast::RecordExpr,
     ) -> Option<Vec<(Field, Type)>> {
         let krate = self.resolver.krate()?;
         let body = self.body.as_ref()?;
@@ -341,13 +352,13 @@ impl SourceAnalyzer {
         let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
             self.resolver.resolve_path_as_macro(db.upcast(), &path)
         })?;
-        Some(macro_call_id.as_file())
+        Some(macro_call_id.as_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
     }
 
     pub(crate) fn resolve_variant(
         &self,
         db: &dyn HirDatabase,
-        record_lit: ast::RecordLit,
+        record_lit: ast::RecordExpr,
     ) -> Option<VariantId> {
         let infer = self.infer.as_ref()?;
         let expr_id = self.expr_id(db, &record_lit.into())?;
@@ -394,8 +405,7 @@ fn scope_for_offset(
             )
         })
         .map(|(expr_range, scope)| {
-            adjust(db, scopes, source_map, expr_range, offset.file_id, offset.value)
-                .unwrap_or(*scope)
+            adjust(db, scopes, source_map, expr_range, offset).unwrap_or(*scope)
         })
 }
 
@@ -406,8 +416,7 @@ fn adjust(
     scopes: &ExprScopes,
     source_map: &BodySourceMap,
     expr_range: TextRange,
-    file_id: HirFileId,
-    offset: TextSize,
+    offset: InFile<TextSize>,
 ) -> Option<ScopeId> {
     let child_scopes = scopes
         .scope_by_expr()
@@ -415,7 +424,7 @@ fn adjust(
         .filter_map(|(id, scope)| {
             let source = source_map.expr_syntax(*id).ok()?;
             // FIXME: correctly handle macro expansion
-            if source.file_id != file_id {
+            if source.file_id != offset.file_id {
                 return None;
             }
             let root = source.file_syntax(db.upcast());
@@ -423,7 +432,7 @@ fn adjust(
             Some((node.syntax().text_range(), scope))
         })
         .filter(|&(range, _)| {
-            range.start() <= offset && expr_range.contains_range(range) && range != expr_range
+            range.start() <= offset.value && expr_range.contains_range(range) && range != expr_range
         });
 
     child_scopes