4 files changed, 141 insertions, 34 deletions

diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index 058e37ff0..9503c936d 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 {
@@ -68,7 +71,7 @@ pub(super) fn element(
         }
         NAME_REF => {
             let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
-            highlight_func_by_name_ref(sema, &name_ref).unwrap_or_else(|| {
+            highlight_func_by_name_ref(sema, krate, &name_ref).unwrap_or_else(|| {
                 let is_self = name_ref.self_token().is_some();
                 let h = match NameRefClass::classify(sema, &name_ref) {
                     Some(name_kind) => match name_kind {
@@ -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) {
@@ -105,7 +108,7 @@ pub(super) fn element(
                         NameRefClass::FieldShorthand { .. } => SymbolKind::Field.into(),
                     },
                     None if syntactic_name_ref_highlighting => {
-                        highlight_name_ref_by_syntax(name_ref, sema)
+                        highlight_name_ref_by_syntax(name_ref, sema, krate)
                     }
                     None => HlTag::UnresolvedReference.into(),
                 };
@@ -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,
@@ -277,12 +282,12 @@ pub(super) fn element(
         hash((name, shadow_count))
     }
 }
-fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
-    match def {
-        Definition::Macro(_) => HlTag::Symbol(SymbolKind::Macro),
-        Definition::Field(_) => HlTag::Symbol(SymbolKind::Field),
+fn highlight_def(db: &RootDatabase, krate: Option<hir::Crate>, def: Definition) -> Highlight {
+    let mut h = match def {
+        Definition::Macro(_) => Highlight::new(HlTag::Symbol(SymbolKind::Macro)),
+        Definition::Field(_) => Highlight::new(HlTag::Symbol(SymbolKind::Field)),
         Definition::ModuleDef(def) => match def {
-            hir::ModuleDef::Module(_) => HlTag::Symbol(SymbolKind::Module),
+            hir::ModuleDef::Module(_) => Highlight::new(HlTag::Symbol(SymbolKind::Module)),
             hir::ModuleDef::Function(func) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Function));
                 if let Some(item) = func.as_assoc_item(db) {
@@ -314,14 +319,22 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                 if func.is_async(db) {
                     h |= HlMod::Async;
                 }
-                return h;
+
+                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),
+                };
+
+                Highlight::new(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::Variant(_) => Highlight::new(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) {
@@ -336,7 +349,7 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                     }
                 }
 
-                return h;
+                h
             }
             hir::ModuleDef::Trait(trait_) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Trait));
@@ -344,10 +357,12 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                 if trait_.is_unsafe(db) {
                     h |= HlMod::Unsafe;
                 }
-                return h;
+
+                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) {
@@ -361,23 +376,30 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                         }
                     }
                 }
-                return h;
+
+                h
             }
-            hir::ModuleDef::BuiltinType(_) => HlTag::BuiltinType,
+            hir::ModuleDef::BuiltinType(_) => Highlight::new(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;
                 }
-                return h;
+
+                h
             }
         },
-        Definition::SelfType(_) => HlTag::Symbol(SymbolKind::Impl),
+        Definition::SelfType(_) => Highlight::new(HlTag::Symbol(SymbolKind::Impl)),
         Definition::GenericParam(it) => match it {
-            hir::GenericParam::TypeParam(_) => HlTag::Symbol(SymbolKind::TypeParam),
-            hir::GenericParam::ConstParam(_) => HlTag::Symbol(SymbolKind::ConstParam),
-            hir::GenericParam::LifetimeParam(_) => HlTag::Symbol(SymbolKind::LifetimeParam),
+            hir::GenericParam::TypeParam(_) => Highlight::new(HlTag::Symbol(SymbolKind::TypeParam)),
+            hir::GenericParam::ConstParam(_) => {
+                Highlight::new(HlTag::Symbol(SymbolKind::ConstParam))
+            }
+            hir::GenericParam::LifetimeParam(_) => {
+                Highlight::new(HlTag::Symbol(SymbolKind::LifetimeParam))
+            }
         },
         Definition::Local(local) => {
             let tag = if local.is_self(db) {
@@ -395,28 +417,40 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
             if ty.as_callable(db).is_some() || ty.impls_fnonce(db) {
                 h |= HlMod::Callable;
             }
-            return h;
+            h
         }
-        Definition::Label(_) => HlTag::Symbol(SymbolKind::Label),
+        Definition::Label(_) => Highlight::new(HlTag::Symbol(SymbolKind::Label)),
+    };
+
+    let is_from_other_crate = def.module(db).map(hir::Module::krate) != krate;
+    let is_builtin_type = matches!(def, Definition::ModuleDef(hir::ModuleDef::BuiltinType(_)));
+
+    if is_from_other_crate && !is_builtin_type {
+        h |= HlMod::Library;
     }
-    .into()
+
+    h
 }
 
 fn highlight_func_by_name_ref(
     sema: &Semantics<RootDatabase>,
+    krate: Option<hir::Crate>,
     name_ref: &ast::NameRef,
 ) -> Option<Highlight> {
     let mc = name_ref.syntax().parent().and_then(ast::MethodCallExpr::cast)?;
-    highlight_method_call(sema, &mc)
+    highlight_method_call(sema, krate, &mc)
 }
 
 fn highlight_method_call(
     sema: &Semantics<RootDatabase>,
+    krate: Option<hir::Crate>,
     method_call: &ast::MethodCallExpr,
 ) -> Option<Highlight> {
     let func = sema.resolve_method_call(&method_call)?;
+
     let mut h = SymbolKind::Function.into();
     h |= HlMod::Associated;
+
     if func.is_unsafe(sema.db) || sema.is_unsafe_method_call(&method_call) {
         h |= HlMod::Unsafe;
     }
@@ -424,7 +458,10 @@ fn highlight_method_call(
         h |= HlMod::Async;
     }
     if func.as_assoc_item(sema.db).and_then(|it| it.containing_trait(sema.db)).is_some() {
-        h |= HlMod::Trait
+        h |= HlMod::Trait;
+    }
+    if Some(func.module(sema.db).krate()) != krate {
+        h |= HlMod::Library;
     }
 
     if let Some(self_param) = func.self_param(sema.db) {
@@ -473,7 +510,11 @@ fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
     tag.into()
 }
 
-fn highlight_name_ref_by_syntax(name: ast::NameRef, sema: &Semantics<RootDatabase>) -> Highlight {
+fn highlight_name_ref_by_syntax(
+    name: ast::NameRef,
+    sema: &Semantics<RootDatabase>,
+    krate: Option<hir::Crate>,
+) -> Highlight {
     let default = HlTag::UnresolvedReference;
 
     let parent = match name.syntax().parent() {
@@ -484,7 +525,7 @@ fn highlight_name_ref_by_syntax(name: ast::NameRef, sema: &Semantics<RootDatabas
     match parent.kind() {
         METHOD_CALL_EXPR => {
             return ast::MethodCallExpr::cast(parent)
-                .and_then(|it| highlight_method_call(sema, &it))
+                .and_then(|it| highlight_method_call(sema, krate, &it))
                 .unwrap_or_else(|| SymbolKind::Function.into());
         }
         FIELD_EXPR => {
diff --git a/crates/ide/src/syntax_highlighting/tags.rs b/crates/ide/src/syntax_highlighting/tags.rs
index 27473a2f9..9d481deae 100644
--- a/crates/ide/src/syntax_highlighting/tags.rs
+++ b/crates/ide/src/syntax_highlighting/tags.rs
@@ -37,6 +37,8 @@ pub enum HlTag {
     None,
 }
 
+// Don't forget to adjust the feature description in crates/ide/src/syntax_highlighting.rs.
+// And make sure to use the lsp strings used when converting to the protocol in crates\rust-analyzer\src\semantic_tokens.rs, not the names of the variants here.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
 #[repr(u8)]
 pub enum HlMod {
@@ -67,6 +69,8 @@ pub enum HlMod {
     Trait,
     /// Used with keywords like `async` and `await`.
     Async,
+    /// Used for items from other crates.
+    Library,
     // Keep this last!
     /// Used for unsafe functions, unsafe traits, mutable statics, union accesses and unsafe operations.
     Unsafe,
@@ -189,6 +193,7 @@ impl HlMod {
         HlMod::Static,
         HlMod::Trait,
         HlMod::Async,
+        HlMod::Library,
         HlMod::Unsafe,
     ];
 
@@ -207,6 +212,7 @@ impl HlMod {
             HlMod::Static => "static",
             HlMod::Trait => "trait",
             HlMod::Async => "async",
+            HlMod::Library => "library",
             HlMod::Unsafe => "unsafe",
         }
     }
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlighting.html b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
index 878431b56..0264e39a3 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlighting.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
@@ -248,4 +248,20 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="brace">}</span>
 
 <span class="keyword unsafe">unsafe</span> <span class="keyword">trait</span> <span class="trait declaration unsafe">Dangerous</span> <span class="brace">{</span><span class="brace">}</span>
-<span class="keyword">impl</span> <span class="trait unsafe">Dangerous</span> <span class="keyword">for</span> <span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span></code></pre>
\ No newline at end of file
+<span class="keyword">impl</span> <span class="trait unsafe">Dangerous</span> <span class="keyword">for</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">use_foo_items</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
+    <span class="keyword">let</span> <span class="variable declaration">bob</span> <span class="operator">=</span> <span class="module library">foo</span><span class="operator">::</span><span class="struct library">Person</span> <span class="brace">{</span>
+        <span class="field library">name</span><span class="colon">:</span> <span class="string_literal">"Bob"</span><span class="comma">,</span>
+        <span class="field library">age</span><span class="colon">:</span> <span class="module library">foo</span><span class="operator">::</span><span class="module library">consts</span><span class="operator">::</span><span class="constant library">NUMBER</span><span class="comma">,</span>
+    <span class="brace">}</span><span class="semicolon">;</span>
+
+    <span class="keyword">let</span> <span class="variable declaration">control_flow</span> <span class="operator">=</span> <span class="module library">foo</span><span class="operator">::</span><span class="function library">identity</span><span class="parenthesis">(</span><span class="module library">foo</span><span class="operator">::</span><span class="enum library">ControlFlow</span><span class="operator">::</span><span class="enum_variant library">Continue</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+
+    <span class="keyword control">if</span> <span class="variable">control_flow</span><span class="operator">.</span><span class="function associated consuming library">should_die</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
+        foo::<span class="macro">die!</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/tests.rs b/crates/ide/src/syntax_highlighting/tests.rs
index 9ce26e930..662b53481 100644
--- a/crates/ide/src/syntax_highlighting/tests.rs
+++ b/crates/ide/src/syntax_highlighting/tests.rs
@@ -10,6 +10,7 @@ use crate::{fixture, FileRange, HlTag, TextRange};
 fn test_highlighting() {
     check_highlighting(
         r#"
+//- /main.rs crate:main deps:foo
 use inner::{self as inner_mod};
 mod inner {}
 
@@ -222,6 +223,49 @@ async fn async_main() {
 
 unsafe trait Dangerous {}
 impl Dangerous for () {}
+
+fn use_foo_items() {
+    let bob = foo::Person {
+        name: "Bob",
+        age: foo::consts::NUMBER,
+    };
+
+    let control_flow = foo::identity(foo::ControlFlow::Continue);
+
+    if control_flow.should_die() {
+        foo::die!();
+    }
+}
+
+
+//- /foo.rs crate:foo
+pub struct Person {
+    pub name: &'static str,
+    pub age: u8,
+}
+
+pub enum ControlFlow {
+    Continue,
+    Die,
+}
+
+impl ControlFlow {
+    pub fn should_die(self) -> bool {
+        matches!(self, ControlFlow::Die)
+    }
+}
+
+pub fn identity<T>(x: T) -> T { x }
+
+pub mod consts {
+    pub const NUMBER: i64 = 92;
+}
+
+macro_rules! die {
+    () => {
+        panic!();
+    };
+}
 "#
         .trim(),
         expect_file!["./test_data/highlighting.html"],