29 files changed, 208 insertions, 91 deletions

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 4ee08ef21..97f162315 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -44,6 +44,7 @@ use hir_def::{
     per_ns::PerNs,
     resolver::{HasResolver, Resolver},
     src::HasSource as _,
+    type_ref::TraitRef,
     AdtId, AssocContainerId, AssocItemId, AssocItemLoc, AttrDefId, ConstId, ConstParamId,
     DefWithBodyId, EnumId, FunctionId, GenericDefId, HasModule, ImplId, LifetimeParamId,
     LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
@@ -1573,9 +1574,9 @@ impl Impl {
         };
 
         let filter = |impl_def: &Impl| {
-            let target_ty = impl_def.target_ty(db);
-            let rref = target_ty.remove_ref();
-            ty.equals_ctor(rref.as_ref().map_or(&target_ty.ty, |it| &it.ty))
+            let self_ty = impl_def.self_ty(db);
+            let rref = self_ty.remove_ref();
+            ty.equals_ctor(rref.as_ref().map_or(&self_ty.ty, |it| &it.ty))
         };
 
         let mut all = Vec::new();
@@ -1613,16 +1614,16 @@ impl Impl {
 
     // FIXME: the return type is wrong. This should be a hir version of
     // `TraitRef` (ie, resolved `TypeRef`).
-    pub fn target_trait(self, db: &dyn HirDatabase) -> Option<TypeRef> {
+    pub fn trait_(self, db: &dyn HirDatabase) -> Option<TraitRef> {
         db.impl_data(self.id).target_trait.clone()
     }
 
-    pub fn target_ty(self, db: &dyn HirDatabase) -> Type {
+    pub fn self_ty(self, db: &dyn HirDatabase) -> Type {
         let impl_data = db.impl_data(self.id);
         let resolver = self.id.resolver(db.upcast());
         let krate = self.id.lookup(db.upcast()).container.krate();
         let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
-        let ty = ctx.lower_ty(&impl_data.target_type);
+        let ty = ctx.lower_ty(&impl_data.self_ty);
         Type::new_with_resolver_inner(db, krate, &resolver, ty)
     }
 
diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
index 0be868ba2..214bcc648 100644
--- a/crates/hir_def/src/data.rs
+++ b/crates/hir_def/src/data.rs
@@ -10,7 +10,7 @@ use crate::{
     body::Expander,
     db::DefDatabase,
     item_tree::{AssocItem, FunctionQualifier, ItemTreeId, ModItem, Param},
-    type_ref::{TypeBound, TypeRef},
+    type_ref::{TraitRef, TypeBound, TypeRef},
     visibility::RawVisibility,
     AssocContainerId, AssocItemId, ConstId, ConstLoc, FunctionId, FunctionLoc, HasModule, ImplId,
     Intern, Lookup, ModuleId, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
@@ -156,8 +156,8 @@ impl TraitData {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImplData {
-    pub target_trait: Option<TypeRef>,
-    pub target_type: TypeRef,
+    pub target_trait: Option<TraitRef>,
+    pub self_ty: TypeRef,
     pub items: Vec<AssocItemId>,
     pub is_negative: bool,
 }
@@ -170,7 +170,7 @@ impl ImplData {
         let item_tree = impl_loc.id.item_tree(db);
         let impl_def = &item_tree[impl_loc.id.value];
         let target_trait = impl_def.target_trait.map(|id| item_tree[id].clone());
-        let target_type = item_tree[impl_def.target_type].clone();
+        let self_ty = item_tree[impl_def.self_ty].clone();
         let is_negative = impl_def.is_negative;
         let module_id = impl_loc.container;
         let container = AssocContainerId::ImplId(id);
@@ -187,7 +187,7 @@ impl ImplData {
         );
         let items = items.into_iter().map(|(_, item)| item).collect();
 
-        Arc::new(ImplData { target_trait, target_type, items, is_negative })
+        Arc::new(ImplData { target_trait, self_ty, items, is_negative })
     }
 }
 
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index ca0048b16..5449bbf5d 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -31,7 +31,7 @@ use crate::{
     db::DefDatabase,
     generics::GenericParams,
     path::{path, AssociatedTypeBinding, GenericArgs, ImportAlias, ModPath, Path, PathKind},
-    type_ref::{Mutability, TypeBound, TypeRef},
+    type_ref::{Mutability, TraitRef, TypeBound, TypeRef},
     visibility::RawVisibility,
 };
 
@@ -147,6 +147,7 @@ impl ItemTree {
                 vis,
                 generics,
                 type_refs,
+                trait_refs,
                 inner_items,
             } = &mut **data;
 
@@ -173,6 +174,7 @@ impl ItemTree {
             generics.arena.shrink_to_fit();
             type_refs.arena.shrink_to_fit();
             type_refs.map.shrink_to_fit();
+            trait_refs.map.shrink_to_fit();
 
             inner_items.shrink_to_fit();
         }
@@ -295,6 +297,32 @@ impl TypeRefStorage {
     }
 }
 
+/// `TraitRef` interner.
+#[derive(Default, Debug, Eq, PartialEq)]
+struct TraitRefStorage {
+    arena: Arena<Arc<TraitRef>>,
+    map: FxHashMap<Arc<TraitRef>, Idx<Arc<TraitRef>>>,
+}
+
+impl TraitRefStorage {
+    // Note: We lie about the `Idx<TraitRef>` to hide the interner details.
+
+    fn intern(&mut self, ty: TraitRef) -> Idx<TraitRef> {
+        if let Some(id) = self.map.get(&ty) {
+            return Idx::from_raw(id.into_raw());
+        }
+
+        let ty = Arc::new(ty);
+        let idx = self.arena.alloc(ty.clone());
+        self.map.insert(ty, idx);
+        Idx::from_raw(idx.into_raw())
+    }
+
+    fn lookup(&self, id: Idx<TraitRef>) -> &TraitRef {
+        &self.arena[Idx::from_raw(id.into_raw())]
+    }
+}
+
 #[derive(Default, Debug, Eq, PartialEq)]
 struct ItemTreeData {
     imports: Arena<Import>,
@@ -319,6 +347,7 @@ struct ItemTreeData {
     vis: ItemVisibilities,
     generics: GenericParamsStorage,
     type_refs: TypeRefStorage,
+    trait_refs: TraitRefStorage,
 
     inner_items: FxHashMap<FileAstId<ast::BlockExpr>, SmallVec<[ModItem; 1]>>,
 }
@@ -556,6 +585,14 @@ impl Index<Idx<TypeRef>> for ItemTree {
     }
 }
 
+impl Index<Idx<TraitRef>> for ItemTree {
+    type Output = TraitRef;
+
+    fn index(&self, id: Idx<TraitRef>) -> &Self::Output {
+        self.data().trait_refs.lookup(id)
+    }
+}
+
 impl<N: ItemTreeNode> Index<FileItemTreeId<N>> for ItemTree {
     type Output = N;
     fn index(&self, id: FileItemTreeId<N>) -> &N {
@@ -692,8 +729,8 @@ pub struct Trait {
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct Impl {
     pub generic_params: GenericParamsId,
-    pub target_trait: Option<Idx<TypeRef>>,
-    pub target_type: Idx<TypeRef>,
+    pub target_trait: Option<Idx<TraitRef>>,
+    pub self_ty: Idx<TypeRef>,
     pub is_negative: bool,
     pub items: Box<[AssocItem]>,
     pub ast_id: FileAstId<ast::Impl>,
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 3f558edd8..8d3862811 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -11,7 +11,7 @@ use syntax::{
 
 use crate::{
     generics::{GenericParams, TypeParamData, TypeParamProvenance},
-    type_ref::LifetimeRef,
+    type_ref::{LifetimeRef, TraitRef},
 };
 
 use super::*;
@@ -536,8 +536,11 @@ impl Ctx {
     fn lower_impl(&mut self, impl_def: &ast::Impl) -> Option<FileItemTreeId<Impl>> {
         let generic_params =
             self.lower_generic_params_and_inner_items(GenericsOwner::Impl, impl_def);
-        let target_trait = impl_def.trait_().map(|tr| self.lower_type_ref(&tr));
-        let target_type = self.lower_type_ref(&impl_def.self_ty()?);
+        // FIXME: If trait lowering fails, due to a non PathType for example, we treat this impl
+        // as if it was an non-trait impl. Ideally we want to create a unique missing ref that only
+        // equals itself.
+        let target_trait = impl_def.trait_().and_then(|tr| self.lower_trait_ref(&tr));
+        let self_ty = self.lower_type_ref(&impl_def.self_ty()?);
         let is_negative = impl_def.excl_token().is_some();
 
         // We cannot use `assoc_items()` here as that does not include macro calls.
@@ -554,7 +557,7 @@ impl Ctx {
             })
             .collect();
         let ast_id = self.source_ast_id_map.ast_id(impl_def);
-        let res = Impl { generic_params, target_trait, target_type, is_negative, items, ast_id };
+        let res = Impl { generic_params, target_trait, self_ty, is_negative, items, ast_id };
         Some(id(self.data().impls.alloc(res)))
     }
 
@@ -740,10 +743,16 @@ impl Ctx {
         self.data().vis.alloc(vis)
     }
 
+    fn lower_trait_ref(&mut self, trait_ref: &ast::Type) -> Option<Idx<TraitRef>> {
+        let trait_ref = TraitRef::from_ast(&self.body_ctx, trait_ref.clone())?;
+        Some(self.data().trait_refs.intern(trait_ref))
+    }
+
     fn lower_type_ref(&mut self, type_ref: &ast::Type) -> Idx<TypeRef> {
         let tyref = TypeRef::from_ast(&self.body_ctx, type_ref.clone());
         self.data().type_refs.intern(tyref)
     }
+
     fn lower_type_ref_opt(&mut self, type_ref: Option<ast::Type>) -> Idx<TypeRef> {
         match type_ref.map(|ty| self.lower_type_ref(&ty)) {
             Some(it) => it,
diff --git a/crates/hir_def/src/type_ref.rs b/crates/hir_def/src/type_ref.rs
index 049b2e462..4c24aae94 100644
--- a/crates/hir_def/src/type_ref.rs
+++ b/crates/hir_def/src/type_ref.rs
@@ -51,6 +51,23 @@ impl Rawness {
     }
 }
 
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub struct TraitRef {
+    pub path: Path,
+}
+
+impl TraitRef {
+    /// Converts an `ast::PathType` to a `hir::TraitRef`.
+    pub(crate) fn from_ast(ctx: &LowerCtx, node: ast::Type) -> Option<Self> {
+        // FIXME: Use `Path::from_src`
+        match node {
+            ast::Type::PathType(path) => {
+                path.path().and_then(|it| ctx.lower_path(it)).map(|path| TraitRef { path })
+            }
+            _ => None,
+        }
+    }
+}
 /// Compare ty::Ty
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub enum TypeRef {
diff --git a/crates/hir_ty/src/diagnostics/match_check.rs b/crates/hir_ty/src/diagnostics/match_check.rs
index 5a5cdcbf3..9cb472b51 100644
--- a/crates/hir_ty/src/diagnostics/match_check.rs
+++ b/crates/hir_ty/src/diagnostics/match_check.rs
@@ -539,7 +539,7 @@ impl Matrix {
         if let Some(Pat::Or(pat_ids)) = row.get_head().map(|pat_id| pat_id.as_pat(cx)) {
             // Or patterns are expanded here
             for pat_id in pat_ids {
-                self.0.push(PatStack::from_pattern(pat_id));
+                self.0.push(row.replace_head_with([pat_id].iter()));
             }
         } else {
             self.0.push(row);
@@ -1085,6 +1085,20 @@ fn main() {
     }
 
     #[test]
+    fn or_pattern_no_diagnostic() {
+        check_diagnostics(
+            r#"
+enum Either {A, B}
+
+fn main() {
+    match (Either::A, Either::B) {
+        (Either::A | Either::B, _) => (),
+    }
+}"#,
+        )
+    }
+
+    #[test]
     fn mismatched_types() {
         // Match statements with arms that don't match the
         // expression pattern do not fire this diagnostic.
@@ -1336,30 +1350,6 @@ fn bang(never: !) {
     }
 
     #[test]
-    fn or_pattern_panic() {
-        check_diagnostics(
-            r#"
-pub enum Category { Infinity, Zero }
-
-fn panic(a: Category, b: Category) {
-    match (a, b) {
-        (Category::Zero | Category::Infinity, _) => (),
-        (_, Category::Zero | Category::Infinity) => (),
-    }
-
-    // FIXME: This is a false positive, but the code used to cause a panic in the match checker,
-    // so this acts as a regression test for that.
-    match (a, b) {
-        //^^^^^^ Missing match arm
-        (Category::Infinity, Category::Infinity) | (Category::Zero, Category::Zero) => (),
-        (Category::Infinity | Category::Zero, _) => (),
-    }
-}
-"#,
-        );
-    }
-
-    #[test]
     fn unknown_type() {
         check_diagnostics(
             r#"
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index c87789d45..afbfa12d5 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -15,7 +15,7 @@ use hir_def::{
     generics::{TypeParamProvenance, WherePredicate, WherePredicateTypeTarget},
     path::{GenericArg, Path, PathSegment, PathSegments},
     resolver::{HasResolver, Resolver, TypeNs},
-    type_ref::{TypeBound, TypeRef},
+    type_ref::{TraitRef as HirTraitRef, TypeBound, TypeRef},
     AdtId, AssocContainerId, AssocItemId, ConstId, ConstParamId, EnumId, EnumVariantId, FunctionId,
     GenericDefId, HasModule, ImplId, LocalFieldId, Lookup, StaticId, StructId, TraitId,
     TypeAliasId, TypeParamId, UnionId, VariantId,
@@ -667,14 +667,10 @@ impl<'a> TyLoweringContext<'a> {
 
     fn lower_trait_ref(
         &self,
-        type_ref: &TypeRef,
+        trait_ref: &HirTraitRef,
         explicit_self_ty: Option<Ty>,
     ) -> Option<TraitRef> {
-        let path = match type_ref {
-            TypeRef::Path(path) => path,
-            _ => return None,
-        };
-        self.lower_trait_ref_from_path(path, explicit_self_ty)
+        self.lower_trait_ref_from_path(&trait_ref.path, explicit_self_ty)
     }
 
     fn trait_ref_substs_from_path(
@@ -1253,7 +1249,7 @@ pub(crate) fn impl_self_ty_query(db: &dyn HirDatabase, impl_id: ImplId) -> Binde
     let generics = generics(db.upcast(), impl_id.into());
     let ctx =
         TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
-    Binders::new(generics.len(), ctx.lower_ty(&impl_data.target_type))
+    Binders::new(generics.len(), ctx.lower_ty(&impl_data.self_ty))
 }
 
 pub(crate) fn const_param_ty_query(db: &dyn HirDatabase, def: ConstParamId) -> Ty {
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index 99276168f..67e2e5a1c 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -237,7 +237,7 @@ fn get_doc_link(db: &RootDatabase, definition: Definition) -> Option<String> {
                 .and_then(|assoc| match assoc.container(db) {
                     AssocItemContainer::Trait(t) => Some(t.into()),
                     AssocItemContainer::Impl(impld) => {
-                        impld.target_ty(db).as_adt().map(|adt| adt.into())
+                        impld.self_ty(db).as_adt().map(|adt| adt.into())
                     }
                 })
                 .unwrap_or_else(|| f.clone().into()),
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 02a1a5b37..7e35a1450 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -195,7 +195,7 @@ fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<Hov
     let adt = match def {
         Definition::ModuleDef(ModuleDef::Trait(it)) => return it.try_to_nav(db).map(to_action),
         Definition::ModuleDef(ModuleDef::Adt(it)) => Some(it),
-        Definition::SelfType(it) => it.target_ty(db).as_adt(),
+        Definition::SelfType(it) => it.self_ty(db).as_adt(),
         _ => None,
     }?;
     adt.try_to_nav(db).map(to_action)
@@ -318,7 +318,7 @@ fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String>
         Definition::ModuleDef(md) => match md {
             ModuleDef::Function(f) => match f.as_assoc_item(db)?.container(db) {
                 AssocItemContainer::Trait(t) => Some(t.name(db)),
-                AssocItemContainer::Impl(i) => i.target_ty(db).as_adt().map(|adt| adt.name(db)),
+                AssocItemContainer::Impl(i) => i.self_ty(db).as_adt().map(|adt| adt.name(db)),
             },
             ModuleDef::Variant(e) => Some(e.parent_enum(db).name(db)),
             _ => None,
@@ -376,7 +376,7 @@ fn hover_for_definition(
         },
         Definition::Local(it) => hover_for_local(it, db),
         Definition::SelfType(impl_def) => {
-            impl_def.target_ty(db).as_adt().and_then(|adt| from_hir_fmt(db, adt, mod_path))
+            impl_def.self_ty(db).as_adt().and_then(|adt| from_hir_fmt(db, adt, mod_path))
         }
         Definition::GenericParam(it) => from_hir_fmt(db, it, None),
         Definition::Label(it) => Some(Markup::fenced_block(&it.name(db))),
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 26d6dc9c9..98456967a 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -307,7 +307,7 @@ fn rename_to_self(sema: &Semantics<RootDatabase>, local: hir::Local) -> RenameRe
         hir::AssocItemContainer::Impl(impl_) => impl_,
     };
     let first_param_ty = first_param.ty();
-    let impl_ty = impl_.target_ty(sema.db);
+    let impl_ty = impl_.self_ty(sema.db);
     let (ty, self_param) = if impl_ty.remove_ref().is_some() {
         // if the impl is a ref to the type we can just match the `&T` with self directly
         (first_param_ty.clone(), "self")
diff --git a/crates/ide/src/runnables.rs b/crates/ide/src/runnables.rs
index 7e4c5a078..11bd385bb 100644
--- a/crates/ide/src/runnables.rs
+++ b/crates/ide/src/runnables.rs
@@ -298,7 +298,7 @@ fn module_def_doctest(sema: &Semantics<RootDatabase>, def: hir::ModuleDef) -> Op
             // FIXME: this also looks very wrong
             if let Some(assoc_def) = assoc_def {
                 if let hir::AssocItemContainer::Impl(imp) = assoc_def.container(sema.db) {
-                    let ty = imp.target_ty(sema.db);
+                    let ty = imp.self_ty(sema.db);
                     if let Some(adt) = ty.as_adt() {
                         let name = adt.name(sema.db);
                         let idx = path.rfind(':').map_or(0, |idx| idx + 1);
diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index b0cfdd8b7..5ccb84714 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -1,6 +1,6 @@
 //! Computes color for a single element.
 
-use hir::{AsAssocItem, Semantics, VariantDef};
+use hir::{AsAssocItem, AssocItemContainer, Semantics, VariantDef};
 use ide_db::{
     defs::{Definition, NameClass, NameRefClass},
     RootDatabase, SymbolKind,
@@ -275,12 +275,24 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
             hir::ModuleDef::Module(_) => HlTag::Symbol(SymbolKind::Module),
             hir::ModuleDef::Function(func) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Function));
-                if func.as_assoc_item(db).is_some() {
+                if let Some(item) = func.as_assoc_item(db) {
                     h |= HlMod::Associated;
                     if func.self_param(db).is_none() {
                         h |= HlMod::Static
                     }
+
+                    match item.container(db) {
+                        AssocItemContainer::Impl(i) => {
+                            if i.trait_(db).is_some() {
+                                h |= HlMod::Trait;
+                            }
+                        }
+                        AssocItemContainer::Trait(_t) => {
+                            h |= HlMod::Trait;
+                        }
+                    }
                 }
+
                 if func.is_unsafe(db) {
                     h |= HlMod::Unsafe;
                 }
@@ -292,9 +304,20 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
             hir::ModuleDef::Variant(_) => HlTag::Symbol(SymbolKind::Variant),
             hir::ModuleDef::Const(konst) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Const));
-                if konst.as_assoc_item(db).is_some() {
-                    h |= HlMod::Associated
+                if let Some(item) = konst.as_assoc_item(db) {
+                    h |= HlMod::Associated;
+                    match item.container(db) {
+                        AssocItemContainer::Impl(i) => {
+                            if i.trait_(db).is_some() {
+                                h |= HlMod::Trait;
+                            }
+                        }
+                        AssocItemContainer::Trait(_t) => {
+                            h |= HlMod::Trait;
+                        }
+                    }
                 }
+
                 return h;
             }
             hir::ModuleDef::Trait(_) => HlTag::Symbol(SymbolKind::Trait),
@@ -362,6 +385,10 @@ fn highlight_method_call(
     if func.is_unsafe(sema.db) || sema.is_unsafe_method_call(&method_call) {
         h |= HlMod::Unsafe;
     }
+    if func.as_assoc_item(sema.db).and_then(|it| it.containing_trait(sema.db)).is_some() {
+        h |= HlMod::Trait
+    }
+
     if let Some(self_param) = func.self_param(sema.db) {
         match self_param.access(sema.db) {
             hir::Access::Shared => (),
diff --git a/crates/ide/src/syntax_highlighting/tags.rs b/crates/ide/src/syntax_highlighting/tags.rs
index 93db79b89..1cec991aa 100644
--- a/crates/ide/src/syntax_highlighting/tags.rs
+++ b/crates/ide/src/syntax_highlighting/tags.rs
@@ -58,6 +58,8 @@ pub enum HlMod {
     Associated,
     /// Used for intra doc links in doc injection.
     IntraDocLink,
+    /// Used for items in traits and trait impls.
+    Trait,
 
     /// Keep this last!
     Unsafe,
@@ -158,6 +160,7 @@ impl HlMod {
         HlMod::Callable,
         HlMod::Static,
         HlMod::Associated,
+        HlMod::Trait,
         HlMod::Unsafe,
     ];
 
@@ -174,6 +177,7 @@ impl HlMod {
             HlMod::IntraDocLink => "intra_doc_link",
             HlMod::Mutable => "mutable",
             HlMod::Static => "static",
+            HlMod::Trait => "trait",
             HlMod::Unsafe => "unsafe",
         }
     }
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlight_assoc_functions.html b/crates/ide/src/syntax_highlighting/test_data/highlight_assoc_functions.html
index 4635ea927..8cde3906c 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_assoc_functions.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_assoc_functions.html
@@ -47,12 +47,12 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="brace">}</span>
 
 <span class="keyword">trait</span> <span class="trait declaration">t</span> <span class="brace">{</span>
-    <span class="keyword">fn</span> <span class="function declaration static associated">t_is_static</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
-    <span class="keyword">fn</span> <span class="function declaration associated">t_is_not_static</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
+    <span class="keyword">fn</span> <span class="function declaration static associated trait">t_is_static</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
+    <span class="keyword">fn</span> <span class="function declaration associated trait">t_is_not_static</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
 <span class="brace">}</span>
 
 <span class="keyword">impl</span> <span class="trait">t</span> <span class="keyword">for</span> <span class="struct">foo</span> <span class="brace">{</span>
-    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration static associated">is_static</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
-    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration associated">is_not_static</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
+    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration static associated trait">is_static</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
+    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration associated trait">is_not_static</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
 <span class="brace">}</span>
         </code></pre>
\ No newline at end of file
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlight_injection.html b/crates/ide/src/syntax_highlighting/test_data/highlight_injection.html
index 9215ddd9e..7c6694a27 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_injection.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_injection.html
@@ -42,7 +42,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="keyword">fn</span> <span class="function declaration">main</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
     <span class="function">fixture</span><span class="parenthesis">(</span><span class="string_literal">r#"</span>
         <span class="keyword">trait</span> <span class="trait declaration">Foo</span> <span class="brace">{</span>
-            <span class="keyword">fn</span> <span class="function declaration static associated">foo</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
+            <span class="keyword">fn</span> <span class="function declaration static associated trait">foo</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
                 <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"2 + 2 = {}"</span><span class="comma">,</span> <span class="numeric_literal">4</span><span class="parenthesis">)</span><span class="semicolon">;</span>
             <span class="brace">}</span>
         <span class="brace">}</span><span class="string_literal">"#</span>
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlight_unsafe.html b/crates/ide/src/syntax_highlighting/test_data/highlight_unsafe.html
index 6a6555208..72910421d 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_unsafe.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_unsafe.html
@@ -62,11 +62,11 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="brace">}</span>
 
 <span class="keyword">trait</span> <span class="trait declaration">DoTheAutoref</span> <span class="brace">{</span>
-    <span class="keyword">fn</span> <span class="function declaration associated">calls_autoref</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+    <span class="keyword">fn</span> <span class="function declaration associated trait">calls_autoref</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span><span class="semicolon">;</span>
 <span class="brace">}</span>
 
 <span class="keyword">impl</span> <span class="trait">DoTheAutoref</span> <span class="keyword">for</span> <span class="builtin_type">u16</span> <span class="brace">{</span>
-    <span class="keyword">fn</span> <span class="function declaration associated">calls_autoref</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
+    <span class="keyword">fn</span> <span class="function declaration associated trait">calls_autoref</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
 <span class="brace">}</span>
 
 <span class="keyword">fn</span> <span class="function declaration">main</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
@@ -96,6 +96,6 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
         <span class="keyword">let</span> <span class="struct">Packed</span> <span class="brace">{</span> <span class="field">a</span><span class="colon">:</span> <span class="keyword unsafe">ref</span> <span class="variable declaration">_a</span> <span class="brace">}</span> <span class="operator">=</span> <span class="variable">packed</span><span class="semicolon">;</span>
 
         <span class="comment">// unsafe auto ref of packed field</span>
-        <span class="variable">packed</span><span class="operator">.</span><span class="field">a</span><span class="operator">.</span><span class="function associated unsafe">calls_autoref</span><span class="parenthesis">(</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+        <span class="variable">packed</span><span class="operator">.</span><span class="field">a</span><span class="operator">.</span><span class="function associated trait unsafe">calls_autoref</span><span class="parenthesis">(</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="brace">}</span>
 <span class="brace">}</span></code></pre>
\ No newline at end of file
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlighting.html b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
index 1eaa7b75b..973173254 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlighting.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
@@ -67,11 +67,11 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="brace">}</span>
 
 <span class="keyword">trait</span> <span class="trait declaration">Bar</span> <span class="brace">{</span>
-    <span class="keyword">fn</span> <span class="function declaration associated">bar</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span><span class="semicolon">;</span>
+    <span class="keyword">fn</span> <span class="function declaration associated trait">bar</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span><span class="semicolon">;</span>
 <span class="brace">}</span>
 
 <span class="keyword">impl</span> <span class="trait">Bar</span> <span class="keyword">for</span> <span class="struct">Foo</span> <span class="brace">{</span>
-    <span class="keyword">fn</span> <span class="function declaration associated">bar</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span> <span class="brace">{</span>
+    <span class="keyword">fn</span> <span class="function declaration associated trait">bar</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="builtin_type">i32</span> <span class="brace">{</span>
         <span class="self_keyword">self</span><span class="operator">.</span><span class="field">x</span>
     <span class="brace">}</span>
 <span class="brace">}</span>
diff --git a/crates/ide_assists/src/handlers/generate_default_from_new.rs b/crates/ide_assists/src/handlers/generate_default_from_new.rs
index 81c54ba3e..dc14552d6 100644
--- a/crates/ide_assists/src/handlers/generate_default_from_new.rs
+++ b/crates/ide_assists/src/handlers/generate_default_from_new.rs
@@ -92,7 +92,7 @@ fn is_default_implemented(ctx: &AssistContext, impl_: &Impl) -> bool {
         None => return false,
     };
 
-    let ty = impl_def.target_ty(db);
+    let ty = impl_def.self_ty(db);
     let krate = impl_def.module(db).krate();
     let default = FamousDefs(&ctx.sema, Some(krate)).core_default_Default();
     let default_trait = match default {
diff --git a/crates/ide_assists/src/handlers/generate_is_empty_from_len.rs b/crates/ide_assists/src/handlers/generate_is_empty_from_len.rs
index b8834d283..910010a04 100644
--- a/crates/ide_assists/src/handlers/generate_is_empty_from_len.rs
+++ b/crates/ide_assists/src/handlers/generate_is_empty_from_len.rs
@@ -91,7 +91,7 @@ fn get_impl_method(
 
     let scope = ctx.sema.scope(impl_.syntax());
     let krate = impl_def.module(db).krate();
-    let ty = impl_def.target_ty(db);
+    let ty = impl_def.self_ty(db);
     let traits_in_scope = scope.traits_in_scope();
     ty.iterate_method_candidates(db, krate, &traits_in_scope, Some(fn_name), |_, func| Some(func))
 }
diff --git a/crates/ide_assists/src/utils.rs b/crates/ide_assists/src/utils.rs
index 5f630ec75..d67524937 100644
--- a/crates/ide_assists/src/utils.rs
+++ b/crates/ide_assists/src/utils.rs
@@ -338,11 +338,11 @@ pub(crate) fn find_struct_impl(
         // (we currently use the wrong type parameter)
         // also we wouldn't want to use e.g. `impl S<u32>`
 
-        let same_ty = match blk.target_ty(db).as_adt() {
+        let same_ty = match blk.self_ty(db).as_adt() {
             Some(def) => def == struct_def,
             None => false,
         };
-        let not_trait_impl = blk.target_trait(db).is_none();
+        let not_trait_impl = blk.trait_(db).is_none();
 
         if !(same_ty && not_trait_impl) {
             None
diff --git a/crates/ide_completion/src/completions.rs b/crates/ide_completion/src/completions.rs
index 6d572a836..e2994eed4 100644
--- a/crates/ide_completion/src/completions.rs
+++ b/crates/ide_completion/src/completions.rs
@@ -220,7 +220,7 @@ fn complete_enum_variants(
         };
 
         if let Some(impl_) = ctx.impl_def.as_ref().and_then(|impl_| ctx.sema.to_def(impl_)) {
-            if impl_.target_ty(ctx.db) == *ty {
+            if impl_.self_ty(ctx.db) == *ty {
                 for &variant in &variants {
                     let self_path = hir::ModPath::from_segments(
                         hir::PathKind::Plain,
diff --git a/crates/ide_completion/src/completions/pattern.rs b/crates/ide_completion/src/completions/pattern.rs
index b06498e6d..808d7ff7e 100644
--- a/crates/ide_completion/src/completions/pattern.rs
+++ b/crates/ide_completion/src/completions/pattern.rs
@@ -40,7 +40,7 @@ pub(crate) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
                 _ => false,
             },
             hir::ScopeDef::MacroDef(_) => true,
-            hir::ScopeDef::ImplSelfType(impl_) => match impl_.target_ty(ctx.db).as_adt() {
+            hir::ScopeDef::ImplSelfType(impl_) => match impl_.self_ty(ctx.db).as_adt() {
                 Some(hir::Adt::Struct(strukt)) => {
                     acc.add_struct_pat(ctx, strukt, Some(name.clone()));
                     true
diff --git a/crates/ide_completion/src/completions/qualified_path.rs b/crates/ide_completion/src/completions/qualified_path.rs
index 105ff6013..1891eb5b3 100644
--- a/crates/ide_completion/src/completions/qualified_path.rs
+++ b/crates/ide_completion/src/completions/qualified_path.rs
@@ -117,7 +117,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
             if let Some(krate) = ctx.krate {
                 let ty = match resolution {
                     PathResolution::TypeParam(param) => param.ty(ctx.db),
-                    PathResolution::SelfType(impl_def) => impl_def.target_ty(ctx.db),
+                    PathResolution::SelfType(impl_def) => impl_def.self_ty(ctx.db),
                     _ => return,
                 };
 
diff --git a/crates/ide_db/src/helpers/import_assets.rs b/crates/ide_db/src/helpers/import_assets.rs
index 3deb0d159..8ce648367 100644
--- a/crates/ide_db/src/helpers/import_assets.rs
+++ b/crates/ide_db/src/helpers/import_assets.rs
@@ -361,7 +361,7 @@ fn item_for_path_search(db: &RootDatabase, item: ItemInNs) -> Option<ItemInNs> {
             Some(assoc_item) => match assoc_item.container(db) {
                 AssocItemContainer::Trait(trait_) => ItemInNs::from(ModuleDef::from(trait_)),
                 AssocItemContainer::Impl(impl_) => {
-                    ItemInNs::from(ModuleDef::from(impl_.target_ty(db).as_adt()?))
+                    ItemInNs::from(ModuleDef::from(impl_.self_ty(db).as_adt()?))
                 }
             },
             None => item,
diff --git a/crates/profile/src/google_cpu_profiler.rs b/crates/profile/src/google_cpu_profiler.rs
index db865c65b..cae6caeaa 100644
--- a/crates/profile/src/google_cpu_profiler.rs
+++ b/crates/profile/src/google_cpu_profiler.rs
@@ -14,26 +14,31 @@ extern "C" {
     fn ProfilerStop();
 }
 
-static PROFILER_STATE: AtomicUsize = AtomicUsize::new(OFF);
 const OFF: usize = 0;
 const ON: usize = 1;
 const PENDING: usize = 2;
 
-pub fn start(path: &Path) {
-    if PROFILER_STATE.compare_and_swap(OFF, PENDING, Ordering::SeqCst) != OFF {
+fn transition(current: usize, new: usize) -> bool {
+    static STATE: AtomicUsize = AtomicUsize::new(OFF);
+
+    STATE.compare_exchange(current, new, Ordering::SeqCst, Ordering::SeqCst).is_ok()
+}
+
+pub(crate) fn start(path: &Path) {
+    if !transition(OFF, PENDING) {
         panic!("profiler already started");
     }
     let path = CString::new(path.display().to_string()).unwrap();
     if unsafe { ProfilerStart(path.as_ptr()) } == 0 {
         panic!("profiler failed to start")
     }
-    assert!(PROFILER_STATE.compare_and_swap(PENDING, ON, Ordering::SeqCst) == PENDING);
+    assert!(transition(PENDING, ON));
 }
 
-pub fn stop() {
-    if PROFILER_STATE.compare_and_swap(ON, PENDING, Ordering::SeqCst) != ON {
+pub(crate) fn stop() {
+    if !transition(ON, PENDING) {
         panic!("profiler is not started")
     }
     unsafe { ProfilerStop() };
-    assert!(PROFILER_STATE.compare_and_swap(PENDING, OFF, Ordering::SeqCst) == PENDING);
+    assert!(transition(PENDING, OFF));
 }
diff --git a/crates/profile/src/lib.rs b/crates/profile/src/lib.rs
index 9ca6341db..a31fb8f43 100644
--- a/crates/profile/src/lib.rs
+++ b/crates/profile/src/lib.rs
@@ -52,7 +52,7 @@ impl Drop for Scope {
 /// Usage:
 /// 1. Install gpref_tools (https://github.com/gperftools/gperftools), probably packaged with your Linux distro.
 /// 2. Build with `cpu_profiler` feature.
-/// 3. Tun the code, the *raw* output would be in the `./out.profile` file.
+/// 3. Run the code, the *raw* output would be in the `./out.profile` file.
 /// 4. Install pprof for visualization (https://github.com/google/pprof).
 /// 5. Bump sampling frequency to once per ms: `export CPUPROFILE_FREQUENCY=1000`
 /// 6. Use something like `pprof -svg target/release/rust-analyzer ./out.profile` to see the results.
@@ -60,8 +60,17 @@ impl Drop for Scope {
 /// For example, here's how I run profiling on NixOS:
 ///
 /// ```bash
-/// $ nix-shell -p gperftools --run \
-///     'cargo run --release -p rust-analyzer -- parse < ~/projects/rustbench/parser.rs > /dev/null'
+/// $ bat -p shell.nix
+/// with import <nixpkgs> {};
+/// mkShell {
+///   buildInputs = [ gperftools ];
+///   shellHook = ''
+///     export LD_LIBRARY_PATH="${gperftools}/lib:"
+///   '';
+/// }
+/// $ set -x CPUPROFILE_FREQUENCY 1000
+/// $ nix-shell --run 'cargo test --release --package rust-analyzer --lib -- benchmarks::benchmark_integrated_highlighting --exact --nocapture'
+/// $ pprof -svg target/release/deps/rust_analyzer-8739592dc93d63cb crates/rust-analyzer/out.profile > profile.svg
 /// ```
 ///
 /// See this diff for how to profile completions:
@@ -81,7 +90,9 @@ pub fn cpu_span() -> CpuSpan {
 
     #[cfg(not(feature = "cpu_profiler"))]
     {
-        eprintln!("cpu_profiler feature is disabled")
+        eprintln!(
+            r#"cpu profiling is disabled, uncomment `default = [ "cpu_profiler" ]` in Cargo.toml to enable."#
+        )
     }
 
     CpuSpan { _private: () }
@@ -91,7 +102,23 @@ impl Drop for CpuSpan {
     fn drop(&mut self) {
         #[cfg(feature = "cpu_profiler")]
         {
-            google_cpu_profiler::stop()
+            google_cpu_profiler::stop();
+            let profile_data = std::env::current_dir().unwrap().join("out.profile");
+            eprintln!("Profile data saved to:\n\n    {}\n", profile_data.display());
+            let mut cmd = std::process::Command::new("pprof");
+            cmd.arg("-svg").arg(std::env::current_exe().unwrap()).arg(&profile_data);
+            let out = cmd.output();
+
+            match out {
+                Ok(out) if out.status.success() => {
+                    let svg = profile_data.with_extension("svg");
+                    std::fs::write(&svg, &out.stdout).unwrap();
+                    eprintln!("Profile rendered to:\n\n    {}\n", svg.display());
+                }
+                _ => {
+                    eprintln!("Failed to run:\n\n   {:?}\n", cmd);
+                }
+            }
         }
     }
 }
diff --git a/crates/rust-analyzer/src/benchmarks.rs b/crates/rust-analyzer/src/benchmarks.rs
index a6f997af8..bf569b40b 100644
--- a/crates/rust-analyzer/src/benchmarks.rs
+++ b/crates/rust-analyzer/src/benchmarks.rs
@@ -51,6 +51,7 @@ fn benchmark_integrated_highlighting() {
     }
 
     profile::init_from("*>100");
+    // let _s = profile::heartbeat_span();
 
     {
         let _it = stdx::timeit("change");
@@ -63,6 +64,7 @@ fn benchmark_integrated_highlighting() {
 
     {
         let _it = stdx::timeit("after change");
+        let _span = profile::cpu_span();
         let analysis = host.analysis();
         analysis.highlight_as_html(file_id, false).unwrap();
     }
diff --git a/crates/rust-analyzer/src/semantic_tokens.rs b/crates/rust-analyzer/src/semantic_tokens.rs
index a3c5e9ccf..2dc8a42f1 100644
--- a/crates/rust-analyzer/src/semantic_tokens.rs
+++ b/crates/rust-analyzer/src/semantic_tokens.rs
@@ -88,6 +88,7 @@ define_semantic_token_modifiers![
     (CONSUMING, "consuming"),
     (UNSAFE, "unsafe"),
     (ATTRIBUTE_MODIFIER, "attribute"),
+    (TRAIT_MODIFIER, "trait"),
     (CALLABLE, "callable"),
     (INTRA_DOC_LINK, "intraDocLink"),
 ];
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index e297a72e6..c3820944b 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -474,6 +474,7 @@ fn semantic_token_type_and_modifiers(
             HlMod::Callable => semantic_tokens::CALLABLE,
             HlMod::Static => lsp_types::SemanticTokenModifier::STATIC,
             HlMod::IntraDocLink => semantic_tokens::INTRA_DOC_LINK,
+            HlMod::Trait => semantic_tokens::TRAIT_MODIFIER,
             HlMod::Associated => continue,
         };
         mods |= modifier;