14 files changed, 295 insertions, 218 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 12a8896a3..29e70d8fc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -45,7 +45,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "backtrace"
-version = "0.3.40"
+version = "0.3.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1113,7 +1113,7 @@ dependencies = [
 name = "ra_prof"
 version = "0.1.0"
 dependencies = [
- "backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.41 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "jemalloc-ctl 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "jemallocator 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1780,7 +1780,7 @@ dependencies = [
 "checksum atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
 "checksum autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
 "checksum autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
-"checksum backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)" = "924c76597f0d9ca25d762c25a4d369d51267536465dc5064bdf0eb073ed477ea"
+"checksum backtrace 0.3.41 (registry+https://github.com/rust-lang/crates.io-index)" = "a4ed64ae6d9ebfd9893193c4b2532b1292ec97bd8271c9d7d0fa90cd78a34cba"
 "checksum backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6575f128516de27e3ce99689419835fce9643a9b215a14d2b5b685be018491"
 "checksum base64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b41b7ea54a0c9d92199de89e20e58d49f02f8e699814ef3fdf266f6f748d15c7"
 "checksum bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e84c238982c4b1e1ee668d136c510c67a13465279c0cb367ea6baf6310620a80"
diff --git a/bors.toml b/bors.toml
index 0bc71860f..bf5553df4 100644
--- a/bors.toml
+++ b/bors.toml
@@ -1,6 +1,6 @@
 status = [
     "Rust (ubuntu-latest)",
-    "Rust (windows-latest)",
+    # "Rust (windows-latest)",
     "Rust (macos-latest)",
     "TypeScript"
 ]
diff --git a/crates/ra_assists/src/assists/add_custom_impl.rs b/crates/ra_assists/src/assists/add_custom_impl.rs
index 9b8955710..52e8c693d 100644
--- a/crates/ra_assists/src/assists/add_custom_impl.rs
+++ b/crates/ra_assists/src/assists/add_custom_impl.rs
@@ -49,7 +49,10 @@ pub(crate) fn add_custom_impl(ctx: AssistCtx<impl HirDatabase>) -> Option<Assist
     let annotated_name = annotated.syntax().text().to_string();
     let start_offset = annotated.syntax().parent()?.text_range().end();
 
-    ctx.add_assist(AssistId("add_custom_impl"), "add custom impl", |edit| {
+    let label =
+        format!("Add Custom impl '{}' for '{}'", trait_token.text().as_str(), annotated_name);
+
+    ctx.add_assist(AssistId("add_custom_impl"), label, |edit| {
         edit.target(attr.syntax().text_range());
 
         let new_attr_input = input
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index a177cebca..3b479356f 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -21,8 +21,8 @@ use hir_expand::{
     MacroDefId,
 };
 use hir_ty::{
-    autoderef, display::HirFormatter, expr::ExprValidator, ApplicationTy, Canonical, InEnvironment,
-    TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk,
+    autoderef, display::HirFormatter, expr::ExprValidator, method_resolution, ApplicationTy,
+    Canonical, InEnvironment, TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk,
 };
 use ra_db::{CrateId, Edition, FileId};
 use ra_prof::profile;
@@ -120,7 +120,8 @@ impl_froms!(
     BuiltinType
 );
 
-pub use hir_def::{attr::Attrs, visibility::Visibility};
+pub use hir_def::{attr::Attrs, visibility::Visibility, AssocItemId};
+use rustc_hash::FxHashSet;
 
 impl Module {
     pub(crate) fn new(krate: Crate, crate_module_id: LocalModuleId) -> Module {
@@ -878,6 +879,28 @@ impl Type {
         }
     }
 
+    /// Checks that particular type `ty` implements `std::future::Future`.
+    /// This function is used in `.await` syntax completion.
+    pub fn impls_future(&self, db: &impl HirDatabase) -> bool {
+        let krate = self.krate;
+
+        let std_future_trait =
+            db.lang_item(krate, "future_trait".into()).and_then(|it| it.as_trait());
+        let std_future_trait = match std_future_trait {
+            Some(it) => it,
+            None => return false,
+        };
+
+        let canonical_ty = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        method_resolution::implements_trait(
+            &canonical_ty,
+            db,
+            self.ty.environment.clone(),
+            krate,
+            std_future_trait,
+        )
+    }
+
     // 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)
@@ -986,6 +1009,65 @@ impl Type {
         None
     }
 
+    pub fn iterate_method_candidates<T>(
+        &self,
+        db: &impl HirDatabase,
+        krate: Crate,
+        traits_in_scope: &FxHashSet<TraitId>,
+        name: Option<&Name>,
+        mut callback: impl FnMut(&Ty, Function) -> Option<T>,
+    ) -> Option<T> {
+        // 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 env = self.ty.environment.clone();
+        let krate = krate.id;
+
+        method_resolution::iterate_method_candidates(
+            &canonical,
+            db,
+            env,
+            krate,
+            traits_in_scope,
+            name,
+            method_resolution::LookupMode::MethodCall,
+            |ty, it| match it {
+                AssocItemId::FunctionId(f) => callback(ty, f.into()),
+                _ => None,
+            },
+        )
+    }
+
+    pub fn iterate_path_candidates<T>(
+        &self,
+        db: &impl HirDatabase,
+        krate: Crate,
+        traits_in_scope: &FxHashSet<TraitId>,
+        name: Option<&Name>,
+        mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
+    ) -> Option<T> {
+        // 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 env = self.ty.environment.clone();
+        let krate = krate.id;
+
+        method_resolution::iterate_method_candidates(
+            &canonical,
+            db,
+            env,
+            krate,
+            traits_in_scope,
+            name,
+            method_resolution::LookupMode::Path,
+            |ty, it| callback(ty, it.into()),
+        )
+    }
+
     pub fn as_adt(&self) -> Option<Adt> {
         let (adt, _subst) = self.ty.value.as_adt()?;
         Some(adt.into())
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 3d13978d4..a1cf89010 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -27,7 +27,7 @@ macro_rules! impl_froms {
 }
 
 pub mod db;
-pub mod source_binder;
+pub mod source_analyzer;
 
 pub mod diagnostics;
 
@@ -46,7 +46,7 @@ pub use crate::{
     },
     from_source::FromSource,
     has_source::HasSource,
-    source_binder::{PathResolution, ScopeEntryWithSyntax, SourceAnalyzer},
+    source_analyzer::{PathResolution, ScopeEntryWithSyntax, SourceAnalyzer},
 };
 
 pub use hir_def::{
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_analyzer.rs
index a2a9d968c..76e0bff34 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -15,17 +15,13 @@ use hir_def::{
     },
     expr::{ExprId, PatId},
     nameres::ModuleSource,
-    path::path,
     resolver::{self, resolver_for_scope, HasResolver, Resolver, TypeNs, ValueNs},
-    AssocItemId, DefWithBodyId,
+    DefWithBodyId, TraitId,
 };
 use hir_expand::{
     hygiene::Hygiene, name::AsName, AstId, HirFileId, InFile, MacroCallId, MacroCallKind,
 };
-use hir_ty::{
-    method_resolution::{self, implements_trait},
-    Canonical, InEnvironment, InferenceResult, TraitEnvironment, Ty,
-};
+use hir_ty::{InEnvironment, InferenceResult, TraitEnvironment};
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AstNode},
@@ -33,71 +29,13 @@ use ra_syntax::{
     SyntaxKind::*,
     SyntaxNode, SyntaxNodePtr, SyntaxToken, TextRange, TextUnit,
 };
+use rustc_hash::FxHashSet;
 
 use crate::{
-    db::HirDatabase, Adt, AssocItem, Const, DefWithBody, Enum, EnumVariant, FromSource, Function,
-    ImplBlock, Local, MacroDef, Name, Path, ScopeDef, Static, Struct, Trait, Type, TypeAlias,
-    TypeParam,
+    db::HirDatabase, Adt, Const, DefWithBody, Enum, EnumVariant, FromSource, Function, ImplBlock,
+    Local, MacroDef, Name, Path, ScopeDef, Static, Struct, Trait, Type, TypeAlias, TypeParam,
 };
 
-fn try_get_resolver_for_node(db: &impl HirDatabase, node: InFile<&SyntaxNode>) -> Option<Resolver> {
-    match_ast! {
-        match (node.value) {
-            ast::Module(it) => {
-                let src = node.with_value(it);
-                Some(crate::Module::from_declaration(db, src)?.id.resolver(db))
-            },
-             ast::SourceFile(it) => {
-                let src = node.with_value(ModuleSource::SourceFile(it));
-                Some(crate::Module::from_definition(db, src)?.id.resolver(db))
-            },
-            ast::StructDef(it) => {
-                let src = node.with_value(it);
-                Some(Struct::from_source(db, src)?.id.resolver(db))
-            },
-            ast::EnumDef(it) => {
-                let src = node.with_value(it);
-                Some(Enum::from_source(db, src)?.id.resolver(db))
-            },
-            ast::ImplBlock(it) => {
-                let src = node.with_value(it);
-                Some(ImplBlock::from_source(db, src)?.id.resolver(db))
-            },
-            ast::TraitDef(it) => {
-                let src = node.with_value(it);
-                Some(Trait::from_source(db, src)?.id.resolver(db))
-            },
-            _ => match node.value.kind() {
-                FN_DEF | CONST_DEF | STATIC_DEF => {
-                    let def = def_with_body_from_child_node(db, node)?;
-                    let def = DefWithBodyId::from(def);
-                    Some(def.resolver(db))
-                }
-                // FIXME add missing cases
-                _ => None
-            }
-        }
-    }
-}
-
-fn def_with_body_from_child_node(
-    db: &impl HirDatabase,
-    child: InFile<&SyntaxNode>,
-) -> Option<DefWithBody> {
-    let _p = profile("def_with_body_from_child_node");
-    child.cloned().ancestors_with_macros(db).find_map(|node| {
-        let n = &node.value;
-        match_ast! {
-            match n {
-                ast::FnDef(def)  => { return Function::from_source(db, node.with_value(def)).map(DefWithBody::from); },
-                ast::ConstDef(def) => { return Const::from_source(db, node.with_value(def)).map(DefWithBody::from); },
-                ast::StaticDef(def) => { return Static::from_source(db, node.with_value(def)).map(DefWithBody::from); },
-                _ => { None },
-            }
-        }
-    })
-}
-
 /// `SourceAnalyzer` is a convenience wrapper which exposes HIR API in terms of
 /// original source files. It should not be used inside the HIR itself.
 #[derive(Debug)]
@@ -409,68 +347,9 @@ impl SourceAnalyzer {
             .collect()
     }
 
-    pub fn iterate_method_candidates<T>(
-        &self,
-        db: &impl HirDatabase,
-        ty: &Type,
-        name: Option<&Name>,
-        mut callback: impl FnMut(&Ty, Function) -> Option<T>,
-    ) -> Option<T> {
-        // There should be no inference vars in types passed here
-        // FIXME check that?
-        // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: ty.ty.value.clone(), num_vars: 0 };
-        method_resolution::iterate_method_candidates(
-            &canonical,
-            db,
-            &self.resolver,
-            name,
-            method_resolution::LookupMode::MethodCall,
-            |ty, it| match it {
-                AssocItemId::FunctionId(f) => callback(ty, f.into()),
-                _ => None,
-            },
-        )
-    }
-
-    pub fn iterate_path_candidates<T>(
-        &self,
-        db: &impl HirDatabase,
-        ty: &Type,
-        name: Option<&Name>,
-        mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
-    ) -> Option<T> {
-        // There should be no inference vars in types passed here
-        // FIXME check that?
-        // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: ty.ty.value.clone(), num_vars: 0 };
-        method_resolution::iterate_method_candidates(
-            &canonical,
-            db,
-            &self.resolver,
-            name,
-            method_resolution::LookupMode::Path,
-            |ty, it| callback(ty, it.into()),
-        )
-    }
-
-    /// Checks that particular type `ty` implements `std::future::Future`.
-    /// This function is used in `.await` syntax completion.
-    pub fn impls_future(&self, db: &impl HirDatabase, ty: Type) -> bool {
-        let std_future_path = path![std::future::Future];
-
-        let std_future_trait = match self.resolver.resolve_known_trait(db, &std_future_path) {
-            Some(it) => it.into(),
-            _ => return false,
-        };
-
-        let krate = match self.resolver.krate() {
-            Some(krate) => krate,
-            _ => return false,
-        };
-
-        let canonical_ty = Canonical { value: ty.ty.value, num_vars: 0 };
-        implements_trait(&canonical_ty, db, &self.resolver, krate.into(), std_future_trait)
+    /// Note: `FxHashSet<TraitId>` should be treated as an opaque type, passed into `Type
+    pub fn traits_in_scope(&self, db: &impl HirDatabase) -> FxHashSet<TraitId> {
+        self.resolver.traits_in_scope(db)
     }
 
     pub fn expand(
@@ -487,6 +366,64 @@ impl SourceAnalyzer {
     }
 }
 
+fn try_get_resolver_for_node(db: &impl HirDatabase, node: InFile<&SyntaxNode>) -> Option<Resolver> {
+    match_ast! {
+        match (node.value) {
+            ast::Module(it) => {
+                let src = node.with_value(it);
+                Some(crate::Module::from_declaration(db, src)?.id.resolver(db))
+            },
+             ast::SourceFile(it) => {
+                let src = node.with_value(ModuleSource::SourceFile(it));
+                Some(crate::Module::from_definition(db, src)?.id.resolver(db))
+            },
+            ast::StructDef(it) => {
+                let src = node.with_value(it);
+                Some(Struct::from_source(db, src)?.id.resolver(db))
+            },
+            ast::EnumDef(it) => {
+                let src = node.with_value(it);
+                Some(Enum::from_source(db, src)?.id.resolver(db))
+            },
+            ast::ImplBlock(it) => {
+                let src = node.with_value(it);
+                Some(ImplBlock::from_source(db, src)?.id.resolver(db))
+            },
+            ast::TraitDef(it) => {
+                let src = node.with_value(it);
+                Some(Trait::from_source(db, src)?.id.resolver(db))
+            },
+            _ => match node.value.kind() {
+                FN_DEF | CONST_DEF | STATIC_DEF => {
+                    let def = def_with_body_from_child_node(db, node)?;
+                    let def = DefWithBodyId::from(def);
+                    Some(def.resolver(db))
+                }
+                // FIXME add missing cases
+                _ => None
+            }
+        }
+    }
+}
+
+fn def_with_body_from_child_node(
+    db: &impl HirDatabase,
+    child: InFile<&SyntaxNode>,
+) -> Option<DefWithBody> {
+    let _p = profile("def_with_body_from_child_node");
+    child.cloned().ancestors_with_macros(db).find_map(|node| {
+        let n = &node.value;
+        match_ast! {
+            match n {
+                ast::FnDef(def)  => { return Function::from_source(db, node.with_value(def)).map(DefWithBody::from); },
+                ast::ConstDef(def) => { return Const::from_source(db, node.with_value(def)).map(DefWithBody::from); },
+                ast::StaticDef(def) => { return Static::from_source(db, node.with_value(def)).map(DefWithBody::from); },
+                _ => { None },
+            }
+        }
+    })
+}
+
 fn scope_for(
     scopes: &ExprScopes,
     source_map: &BodySourceMap,
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 3af05394c..d6a17e469 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -569,12 +569,19 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     ) -> Ty {
         let receiver_ty = self.infer_expr(receiver, &Expectation::none());
         let canonicalized_receiver = self.canonicalizer().canonicalize_ty(receiver_ty.clone());
-        let resolved = method_resolution::lookup_method(
-            &canonicalized_receiver.value,
-            self.db,
-            method_name,
-            &self.resolver,
-        );
+
+        let traits_in_scope = self.resolver.traits_in_scope(self.db);
+
+        let resolved = self.resolver.krate().and_then(|krate| {
+            method_resolution::lookup_method(
+                &canonicalized_receiver.value,
+                self.db,
+                self.trait_env.clone(),
+                krate,
+                &traits_in_scope,
+                method_name,
+            )
+        });
         let (derefed_receiver_ty, method_ty, def_generics) = match resolved {
             Some((ty, func)) => {
                 let ty = canonicalized_receiver.decanonicalize_ty(ty);
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index ffd358367..2c1d4831d 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -11,7 +11,7 @@ use hir_expand::name::Name;
 
 use crate::{db::HirDatabase, method_resolution, Substs, Ty, TypeWalk, ValueTyDefId};
 
-use super::{ExprOrPatId, InferenceContext, TraitRef};
+use super::{ExprOrPatId, InferenceContext, TraitEnvironment, TraitRef};
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     pub(super) fn infer_path(
@@ -193,11 +193,16 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         }
 
         let canonical_ty = self.canonicalizer().canonicalize_ty(ty.clone());
+        let env = TraitEnvironment::lower(self.db, &self.resolver);
+        let krate = self.resolver.krate()?;
+        let traits_in_scope = self.resolver.traits_in_scope(self.db);
 
         method_resolution::iterate_method_candidates(
             &canonical_ty.value,
             self.db,
-            &self.resolver.clone(),
+            env,
+            krate,
+            &traits_in_scope,
             Some(name),
             method_resolution::LookupMode::Path,
             move |_ty, item| {
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index 888dc3116..5bacbbd7c 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -6,13 +6,13 @@ use std::sync::Arc;
 
 use arrayvec::ArrayVec;
 use hir_def::{
-    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocContainerId,
-    AssocItemId, FunctionId, HasModule, ImplId, Lookup, TraitId,
+    lang_item::LangItemTarget, type_ref::Mutability, AssocContainerId, AssocItemId, FunctionId,
+    HasModule, ImplId, Lookup, TraitId,
 };
 use hir_expand::name::Name;
 use ra_db::CrateId;
 use ra_prof::profile;
-use rustc_hash::FxHashMap;
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use super::Substs;
 use crate::{
@@ -144,14 +144,24 @@ impl Ty {
 pub(crate) fn lookup_method(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    traits_in_scope: &FxHashSet<TraitId>,
     name: &Name,
-    resolver: &Resolver,
 ) -> Option<(Ty, FunctionId)> {
-    iterate_method_candidates(ty, db, resolver, Some(name), LookupMode::MethodCall, |ty, f| match f
-    {
-        AssocItemId::FunctionId(f) => Some((ty.clone(), f)),
-        _ => None,
-    })
+    iterate_method_candidates(
+        ty,
+        db,
+        env,
+        krate,
+        &traits_in_scope,
+        Some(name),
+        LookupMode::MethodCall,
+        |ty, f| match f {
+            AssocItemId::FunctionId(f) => Some((ty.clone(), f)),
+            _ => None,
+        },
+    )
 }
 
 /// Whether we're looking up a dotted method call (like `v.len()`) or a path
@@ -172,7 +182,9 @@ pub enum LookupMode {
 pub fn iterate_method_candidates<T>(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
     mode: LookupMode,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
@@ -187,9 +199,7 @@ pub fn iterate_method_candidates<T>(
             // Also note that when we've got a receiver like &S, even if the method we
             // find in the end takes &self, we still do the autoderef step (just as
             // rustc does an autoderef and then autoref again).
-            let environment = TraitEnvironment::lower(db, resolver);
-            let ty = InEnvironment { value: ty.clone(), environment };
-            let krate = resolver.krate()?;
+            let ty = InEnvironment { value: ty.clone(), environment: env.clone() };
 
             // We have to be careful about the order we're looking at candidates
             // in here. Consider the case where we're resolving `x.clone()`
@@ -209,7 +219,9 @@ pub fn iterate_method_candidates<T>(
                 if let Some(result) = iterate_method_candidates_with_autoref(
                     &deref_chain[i..],
                     db,
-                    resolver,
+                    env.clone(),
+                    krate,
+                    traits_in_scope,
                     name,
                     &mut callback,
                 ) {
@@ -220,7 +232,15 @@ pub fn iterate_method_candidates<T>(
         }
         LookupMode::Path => {
             // No autoderef for path lookups
-            iterate_method_candidates_for_self_ty(&ty, db, resolver, name, &mut callback)
+            iterate_method_candidates_for_self_ty(
+                &ty,
+                db,
+                env,
+                krate,
+                traits_in_scope,
+                name,
+                &mut callback,
+            )
         }
     }
 }
@@ -228,7 +248,9 @@ pub fn iterate_method_candidates<T>(
 fn iterate_method_candidates_with_autoref<T>(
     deref_chain: &[Canonical<Ty>],
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
@@ -236,7 +258,9 @@ fn iterate_method_candidates_with_autoref<T>(
         &deref_chain[0],
         &deref_chain[1..],
         db,
-        resolver,
+        env.clone(),
+        krate,
+        &traits_in_scope,
         name,
         &mut callback,
     ) {
@@ -250,7 +274,9 @@ fn iterate_method_candidates_with_autoref<T>(
         &refed,
         deref_chain,
         db,
-        resolver,
+        env.clone(),
+        krate,
+        &traits_in_scope,
         name,
         &mut callback,
     ) {
@@ -264,7 +290,9 @@ fn iterate_method_candidates_with_autoref<T>(
         &ref_muted,
         deref_chain,
         db,
-        resolver,
+        env.clone(),
+        krate,
+        &traits_in_scope,
         name,
         &mut callback,
     ) {
@@ -277,14 +305,15 @@ fn iterate_method_candidates_by_receiver<T>(
     receiver_ty: &Canonical<Ty>,
     rest_of_deref_chain: &[Canonical<Ty>],
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
     // We're looking for methods with *receiver* type receiver_ty. These could
     // be found in any of the derefs of receiver_ty, so we have to go through
     // that.
-    let krate = resolver.krate()?;
     for self_ty in std::iter::once(receiver_ty).chain(rest_of_deref_chain) {
         if let Some(result) =
             iterate_inherent_methods(self_ty, db, name, Some(receiver_ty), krate, &mut callback)
@@ -296,7 +325,9 @@ fn iterate_method_candidates_by_receiver<T>(
         if let Some(result) = iterate_trait_method_candidates(
             self_ty,
             db,
-            resolver,
+            env.clone(),
+            krate,
+            &traits_in_scope,
             name,
             Some(receiver_ty),
             &mut callback,
@@ -310,17 +341,25 @@ fn iterate_method_candidates_by_receiver<T>(
 fn iterate_method_candidates_for_self_ty<T>(
     self_ty: &Canonical<Ty>,
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    let krate = resolver.krate()?;
     if let Some(result) = iterate_inherent_methods(self_ty, db, name, None, krate, &mut callback) {
         return Some(result);
     }
-    if let Some(result) =
-        iterate_trait_method_candidates(self_ty, db, resolver, name, None, &mut callback)
-    {
+    if let Some(result) = iterate_trait_method_candidates(
+        self_ty,
+        db,
+        env,
+        krate,
+        traits_in_scope,
+        name,
+        None,
+        &mut callback,
+    ) {
         return Some(result);
     }
     None
@@ -329,14 +368,13 @@ fn iterate_method_candidates_for_self_ty<T>(
 fn iterate_trait_method_candidates<T>(
     self_ty: &Canonical<Ty>,
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
     receiver_ty: Option<&Canonical<Ty>>,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    let krate = resolver.krate()?;
-    // FIXME: maybe put the trait_env behind a query (need to figure out good input parameters for that)
-    let env = TraitEnvironment::lower(db, resolver);
     // if ty is `impl Trait` or `dyn Trait`, the trait doesn't need to be in scope
     let inherent_trait = self_ty.value.inherent_trait().into_iter();
     // if we have `T: Trait` in the param env, the trait doesn't need to be in scope
@@ -344,8 +382,7 @@ fn iterate_trait_method_candidates<T>(
         .trait_predicates_for_self_ty(&self_ty.value)
         .map(|tr| tr.trait_)
         .flat_map(|t| all_super_traits(db, t));
-    let traits =
-        inherent_trait.chain(traits_from_env).chain(resolver.traits_in_scope(db).into_iter());
+    let traits = inherent_trait.chain(traits_from_env).chain(traits_in_scope.iter().copied());
     'traits: for t in traits {
         let data = db.trait_data(t);
 
@@ -465,7 +502,7 @@ fn transform_receiver_ty(
 pub fn implements_trait(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    env: Arc<TraitEnvironment>,
     krate: CrateId,
     trait_: TraitId,
 ) -> bool {
@@ -474,7 +511,6 @@ pub fn implements_trait(
         // anyway, but currently Chalk doesn't implement `dyn/impl Trait` yet
         return true;
     }
-    let env = TraitEnvironment::lower(db, resolver);
     let goal = generic_implements_goal(db, env, trait_, ty.clone());
     let solution = db.trait_solve(krate.into(), goal);
 
diff --git a/crates/ra_ide/src/completion/complete_dot.rs b/crates/ra_ide/src/completion/complete_dot.rs
index 210a685e4..2ca78c927 100644
--- a/crates/ra_ide/src/completion/complete_dot.rs
+++ b/crates/ra_ide/src/completion/complete_dot.rs
@@ -27,7 +27,7 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     complete_methods(acc, ctx, &receiver_ty);
 
     // Suggest .await syntax for types that implement Future trait
-    if ctx.analyzer.impls_future(ctx.db, receiver_ty) {
+    if receiver_ty.impls_future(ctx.db) {
         CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
             .detail("expr.await")
             .insert_text("await")
@@ -53,13 +53,16 @@ fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Ty
 }
 
 fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
-    let mut seen_methods = FxHashSet::default();
-    ctx.analyzer.iterate_method_candidates(ctx.db, receiver, None, |_ty, func| {
-        if func.has_self_param(ctx.db) && seen_methods.insert(func.name(ctx.db)) {
-            acc.add_function(ctx, func);
-        }
-        None::<()>
-    });
+    if let Some(krate) = ctx.module.map(|it| it.krate()) {
+        let mut seen_methods = FxHashSet::default();
+        let traits_in_scope = ctx.analyzer.traits_in_scope(ctx.db);
+        receiver.iterate_method_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, func| {
+            if func.has_self_param(ctx.db) && seen_methods.insert(func.name(ctx.db)) {
+                acc.add_function(ctx, func);
+            }
+            None::<()>
+        });
+    }
 }
 
 #[cfg(test)]
@@ -525,6 +528,7 @@ mod tests {
 
             //- /std/lib.rs
             pub mod future {
+                #[lang = "future_trait"]
                 pub trait Future {}
             }
             "###, CompletionKind::Keyword),
diff --git a/crates/ra_ide/src/completion/complete_path.rs b/crates/ra_ide/src/completion/complete_path.rs
index 0dce9dc2d..af24e9f48 100644
--- a/crates/ra_ide/src/completion/complete_path.rs
+++ b/crates/ra_ide/src/completion/complete_path.rs
@@ -49,22 +49,24 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) {
                 hir::ModuleDef::TypeAlias(a) => a.ty(ctx.db),
                 _ => unreachable!(),
             };
-            ctx.analyzer.iterate_path_candidates(ctx.db, &ty, None, |_ty, item| {
-                match item {
-                    hir::AssocItem::Function(func) => {
-                        if !func.has_self_param(ctx.db) {
-                            acc.add_function(ctx, func);
-                        }
-                    }
-                    hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
-                    hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
-                }
-                None::<()>
-            });
             // Iterate assoc types separately
             // FIXME: complete T::AssocType
             let krate = ctx.module.map(|m| m.krate());
             if let Some(krate) = krate {
+                let traits_in_scope = ctx.analyzer.traits_in_scope(ctx.db);
+                ty.iterate_path_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, item| {
+                    match item {
+                        hir::AssocItem::Function(func) => {
+                            if !func.has_self_param(ctx.db) {
+                                acc.add_function(ctx, func);
+                            }
+                        }
+                        hir::AssocItem::Const(ct) => acc.add_const(ctx, ct),
+                        hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
+                    }
+                    None::<()>
+                });
+
                 ty.iterate_impl_items(ctx.db, krate, |item| {
                     match item {
                         hir::AssocItem::Function(_) | hir::AssocItem::Const(_) => {}
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index a592f0a12..d5a8bbe4d 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -710,6 +710,7 @@ pub fn handle_code_action(
             title: command.title.clone(),
             kind: match assist.id {
                 AssistId("introduce_variable") => Some("refactor.extract.variable".to_string()),
+                AssistId("add_custom_impl") => Some("refactor.rewrite.add_custom_impl".to_string()),
                 _ => None,
             },
             diagnostics: None,
diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index 3059323aa..746dd4bc3 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -889,32 +889,32 @@
             }
         },
         "vscode-jsonrpc": {
-            "version": "5.0.0-next.5",
-            "resolved": "https://registry.npmjs.org/vscode-jsonrpc/-/vscode-jsonrpc-5.0.0-next.5.tgz",
-            "integrity": "sha512-k9akfglxWgr0dtLNscq2uBq48XJwnhf4EaDxn05KQowRwR0DkNML0zeYqFRLtXZe6x5vpL5ppyu4o6GqL+23YQ=="
+            "version": "5.0.0-next.7",
+            "resolved": "https://registry.npmjs.org/vscode-jsonrpc/-/vscode-jsonrpc-5.0.0-next.7.tgz",
+            "integrity": "sha512-DZuEyxaWuA0srFh9kKu2fudVG6d5CJhte3OW2ILM8lZqpHjI+/D2byrowFd0YmEbyQB2nh0yqg0sa1mhxOtivA=="
         },
         "vscode-languageclient": {
-            "version": "6.0.0-next.9",
-            "resolved": "https://registry.npmjs.org/vscode-languageclient/-/vscode-languageclient-6.0.0-next.9.tgz",
-            "integrity": "sha512-NEpeeFM9FKrrRqlBHXGfwpkhtnjruDz3zfFBP+Cymr10qigAEtE/JsODJsIG/ErGqjh3/JXxu8SUOVTGu5oK+w==",
+            "version": "6.0.0-next.10",
+            "resolved": "https://registry.npmjs.org/vscode-languageclient/-/vscode-languageclient-6.0.0-next.10.tgz",
+            "integrity": "sha512-xJ9KNJnHfGIMz7ewuXijtUTje1Tc2fpuyYS/DHZI/MBwYRLp7L38KnivvYJmUICdPnrQTSvPSWKbjlwWhMlKwQ==",
             "requires": {
                 "semver": "^6.3.0",
-                "vscode-languageserver-protocol": "^3.15.0-next.14"
+                "vscode-languageserver-protocol": "^3.15.0-next.15"
             }
         },
         "vscode-languageserver-protocol": {
-            "version": "3.15.0-next.14",
-            "resolved": "https://registry.npmjs.org/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.15.0-next.14.tgz",
-            "integrity": "sha512-xUwwno6Q6RFd2Z2EWV9D3dQlsKPnHyiZMNWq+EC7JJdp2WH1gRlD+KPX4UGRCnJK0WI5omqHV313IESPwRY5xA==",
+            "version": "3.15.0-next.15",
+            "resolved": "https://registry.npmjs.org/vscode-languageserver-protocol/-/vscode-languageserver-protocol-3.15.0-next.15.tgz",
+            "integrity": "sha512-c1f47pxAtUE+gYTGLoySVA+nBUbPtz8NMOLOB69RiTBQobSJBO1XXKB8TXz8BSxpG5T8qRXeEm2vXrM/eepYKg==",
             "requires": {
-                "vscode-jsonrpc": "^5.0.0-next.5",
-                "vscode-languageserver-types": "^3.15.0-next.9"
+                "vscode-jsonrpc": "^5.0.0-next.7",
+                "vscode-languageserver-types": "^3.15.0-next.10"
             }
         },
         "vscode-languageserver-types": {
-            "version": "3.15.0-next.9",
-            "resolved": "https://registry.npmjs.org/vscode-languageserver-types/-/vscode-languageserver-types-3.15.0-next.9.tgz",
-            "integrity": "sha512-Rl/8qJ6932nrHCdPn+9y0x08uLVQaSLRG+U4JzhyKpWU4eJbVaDRoAcz1Llj7CErJGbPr6kdBvShPy5fRfR+Uw=="
+            "version": "3.15.0-next.10",
+            "resolved": "https://registry.npmjs.org/vscode-languageserver-types/-/vscode-languageserver-types-3.15.0-next.10.tgz",
+            "integrity": "sha512-s9Psd+0sQVkH4o1U7hwTNJRuXQQgFvGVZIim7Wb44tcq54rZou3kJKCtdFEm0aHUuYxIrMPYrzuh1jlqCbRegw=="
         },
         "wrappy": {
             "version": "1.0.2",
diff --git a/editors/code/package.json b/editors/code/package.json
index 7c22d21d3..fe2948861 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -25,7 +25,7 @@
     "dependencies": {
         "jsonc-parser": "^2.1.0",
         "seedrandom": "^3.0.5",
-        "vscode-languageclient": "^6.0.0-next.9"
+        "vscode-languageclient": "^6.0.0-next.10"
     },
     "devDependencies": {
         "@rollup/plugin-commonjs": "^11.0.0",