3 files changed, 84 insertions, 12 deletions

diff --git a/crates/ide/src/syntax_highlighting.rs b/crates/ide/src/syntax_highlighting.rs
index 9df8d21af..cf1a8bad7 100644
--- a/crates/ide/src/syntax_highlighting.rs
+++ b/crates/ide/src/syntax_highlighting.rs
@@ -80,6 +80,7 @@ pub(crate) fn highlight(
         &mut hl,
         &sema,
         InFile::new(file_id.into(), &root),
+        sema.scope(&root).krate(),
         range_to_highlight,
         syntactic_name_ref_highlighting,
     );
@@ -90,6 +91,7 @@ fn traverse(
     hl: &mut Highlights,
     sema: &Semantics<RootDatabase>,
     root: InFile<&SyntaxNode>,
+    krate: Option<hir::Crate>,
     range_to_highlight: TextRange,
     syntactic_name_ref_highlighting: bool,
 ) {
@@ -209,6 +211,7 @@ fn traverse(
 
         if let Some((mut highlight, binding_hash)) = highlight::element(
             &sema,
+            krate,
             &mut bindings_shadow_count,
             syntactic_name_ref_highlighting,
             element_to_highlight.clone(),
diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index 058e37ff0..2d6d8d100 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -19,6 +19,7 @@ use crate::{
 
 pub(super) fn element(
     sema: &Semantics<RootDatabase>,
+    krate: Option<hir::Crate>,
     bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
     syntactic_name_ref_highlighting: bool,
     element: SyntaxElement,
@@ -46,8 +47,10 @@ pub(super) fn element(
 
             match name_kind {
                 Some(NameClass::ExternCrate(_)) => SymbolKind::Module.into(),
-                Some(NameClass::Definition(def)) => highlight_def(db, def) | HlMod::Definition,
-                Some(NameClass::ConstReference(def)) => highlight_def(db, def),
+                Some(NameClass::Definition(def)) => {
+                    highlight_def(db, krate, def) | HlMod::Definition
+                }
+                Some(NameClass::ConstReference(def)) => highlight_def(db, krate, def),
                 Some(NameClass::PatFieldShorthand { field_ref, .. }) => {
                     let mut h = HlTag::Symbol(SymbolKind::Field).into();
                     if let Definition::Field(field) = field_ref {
@@ -82,7 +85,7 @@ pub(super) fn element(
                                 }
                             };
 
-                            let mut h = highlight_def(db, def);
+                            let mut h = highlight_def(db, krate, def);
 
                             if let Definition::Local(local) = &def {
                                 if is_consumed_lvalue(name_ref.syntax().clone().into(), local, db) {
@@ -136,9 +139,11 @@ pub(super) fn element(
             let lifetime = element.into_node().and_then(ast::Lifetime::cast).unwrap();
 
             match NameClass::classify_lifetime(sema, &lifetime) {
-                Some(NameClass::Definition(def)) => highlight_def(db, def) | HlMod::Definition,
+                Some(NameClass::Definition(def)) => {
+                    highlight_def(db, krate, def) | HlMod::Definition
+                }
                 None => match NameRefClass::classify_lifetime(sema, &lifetime) {
-                    Some(NameRefClass::Definition(def)) => highlight_def(db, def),
+                    Some(NameRefClass::Definition(def)) => highlight_def(db, krate, def),
                     _ => SymbolKind::LifetimeParam.into(),
                 },
                 _ => Highlight::from(SymbolKind::LifetimeParam) | HlMod::Definition,
@@ -277,10 +282,26 @@ pub(super) fn element(
         hash((name, shadow_count))
     }
 }
-fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
+fn highlight_def(db: &RootDatabase, krate: Option<hir::Crate>, def: Definition) -> Highlight {
     match def {
-        Definition::Macro(_) => HlTag::Symbol(SymbolKind::Macro),
-        Definition::Field(_) => HlTag::Symbol(SymbolKind::Field),
+        Definition::Macro(m) => {
+            let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Macro));
+
+            if m.krate(db) != krate {
+                h |= HlMod::Foreign;
+            }
+
+            return h;
+        }
+        Definition::Field(field) => {
+            let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Field));
+
+            if Some(field.parent_def(db).krate(db)) != krate {
+                h |= HlMod::Foreign;
+            }
+
+            return h;
+        }
         Definition::ModuleDef(def) => match def {
             hir::ModuleDef::Module(_) => HlTag::Symbol(SymbolKind::Module),
             hir::ModuleDef::Function(func) => {
@@ -314,14 +335,37 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                 if func.is_async(db) {
                     h |= HlMod::Async;
                 }
+                if func.krate(db) != krate {
+                    h |= HlMod::Foreign;
+                }
+                return h;
+            }
+            hir::ModuleDef::Adt(adt) => {
+                let h = match adt {
+                    hir::Adt::Struct(_) => HlTag::Symbol(SymbolKind::Struct),
+                    hir::Adt::Enum(_) => HlTag::Symbol(SymbolKind::Enum),
+                    hir::Adt::Union(_) => HlTag::Symbol(SymbolKind::Union),
+                };
+                let mut h = Highlight::new(h);
+
+                if Some(adt.krate(db)) != krate {
+                    h |= HlMod::Foreign;
+                }
+
+                return h;
+            }
+            hir::ModuleDef::Variant(variant) => {
+                let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Variant));
+
+                if Some(variant.krate(db)) != krate {
+                    h |= HlMod::Foreign;
+                }
+
                 return h;
             }
-            hir::ModuleDef::Adt(hir::Adt::Struct(_)) => HlTag::Symbol(SymbolKind::Struct),
-            hir::ModuleDef::Adt(hir::Adt::Enum(_)) => HlTag::Symbol(SymbolKind::Enum),
-            hir::ModuleDef::Adt(hir::Adt::Union(_)) => HlTag::Symbol(SymbolKind::Union),
-            hir::ModuleDef::Variant(_) => HlTag::Symbol(SymbolKind::Variant),
             hir::ModuleDef::Const(konst) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Const));
+
                 if let Some(item) = konst.as_assoc_item(db) {
                     h |= HlMod::Associated;
                     match item.container(db) {
@@ -336,6 +380,10 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                     }
                 }
 
+                if konst.krate(db) != krate {
+                    h |= HlMod::Foreign;
+                }
+
                 return h;
             }
             hir::ModuleDef::Trait(trait_) => {
@@ -344,10 +392,16 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                 if trait_.is_unsafe(db) {
                     h |= HlMod::Unsafe;
                 }
+
+                if Some(trait_.krate(db)) != krate {
+                    h |= HlMod::Foreign;
+                }
+
                 return h;
             }
             hir::ModuleDef::TypeAlias(type_) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::TypeAlias));
+
                 if let Some(item) = type_.as_assoc_item(db) {
                     h |= HlMod::Associated;
                     match item.container(db) {
@@ -361,15 +415,26 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                         }
                     }
                 }
+
+                if Some(type_.krate(db)) != krate {
+                    h |= HlMod::Foreign;
+                }
+
                 return h;
             }
             hir::ModuleDef::BuiltinType(_) => HlTag::BuiltinType,
             hir::ModuleDef::Static(s) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Static));
+
                 if s.is_mut(db) {
                     h |= HlMod::Mutable;
                     h |= HlMod::Unsafe;
                 }
+
+                if s.krate(db) != krate {
+                    h |= HlMod::Foreign;
+                }
+
                 return h;
             }
         },
diff --git a/crates/ide/src/syntax_highlighting/tags.rs b/crates/ide/src/syntax_highlighting/tags.rs
index 27473a2f9..755599cba 100644
--- a/crates/ide/src/syntax_highlighting/tags.rs
+++ b/crates/ide/src/syntax_highlighting/tags.rs
@@ -67,6 +67,8 @@ pub enum HlMod {
     Trait,
     /// Used with keywords like `async` and `await`.
     Async,
+    /// Used for items from other crates.
+    Foreign,
     // Keep this last!
     /// Used for unsafe functions, unsafe traits, mutable statics, union accesses and unsafe operations.
     Unsafe,
@@ -189,6 +191,7 @@ impl HlMod {
         HlMod::Static,
         HlMod::Trait,
         HlMod::Async,
+        HlMod::Foreign,
         HlMod::Unsafe,
     ];
 
@@ -207,6 +210,7 @@ impl HlMod {
             HlMod::Static => "static",
             HlMod::Trait => "trait",
             HlMod::Async => "async",
+            HlMod::Foreign => "foreign",
             HlMod::Unsafe => "unsafe",
         }
     }