13 files changed, 60 insertions, 19 deletions

diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index 7a53268e8..6834fe11a 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -48,7 +48,13 @@ pub(super) fn element(
             match name_kind {
                 Some(NameClass::ExternCrate(_)) => SymbolKind::Module.into(),
                 Some(NameClass::Definition(def)) => {
-                    highlight_def(db, krate, def) | HlMod::Definition
+                    let mut h = highlight_def(db, krate, def) | HlMod::Definition;
+                    if let Definition::ModuleDef(hir::ModuleDef::Trait(trait_)) = &def {
+                        if trait_.is_unsafe(db) {
+                            h |= HlMod::Unsafe;
+                        }
+                    }
+                    h
                 }
                 Some(NameClass::ConstReference(def)) => highlight_def(db, krate, def),
                 Some(NameClass::PatFieldShorthand { field_ref, .. }) => {
@@ -87,20 +93,34 @@ pub(super) fn element(
 
                             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) {
+                            match def {
+                                Definition::Local(local)
+                                    if is_consumed_lvalue(
+                                        name_ref.syntax().clone().into(),
+                                        &local,
+                                        db,
+                                    ) =>
+                                {
                                     h |= HlMod::Consuming;
                                 }
-                            }
-
-                            if let Some(parent) = name_ref.syntax().parent() {
-                                if matches!(parent.kind(), FIELD_EXPR | RECORD_PAT_FIELD) {
-                                    if let Definition::Field(field) = def {
-                                        if let hir::VariantDef::Union(_) = field.parent_def(db) {
-                                            h |= HlMod::Unsafe;
+                                Definition::ModuleDef(hir::ModuleDef::Trait(trait_))
+                                    if trait_.is_unsafe(db) =>
+                                {
+                                    if ast::Impl::for_trait_name_ref(&name_ref).is_some() {
+                                        h |= HlMod::Unsafe;
+                                    }
+                                }
+                                Definition::Field(field) => {
+                                    if let Some(parent) = name_ref.syntax().parent() {
+                                        if matches!(parent.kind(), FIELD_EXPR | RECORD_PAT_FIELD) {
+                                            if let hir::VariantDef::Union(_) = field.parent_def(db)
+                                            {
+                                                h |= HlMod::Unsafe;
+                                            }
                                         }
                                     }
                                 }
+                                _ => (),
                             }
 
                             h
@@ -354,15 +374,7 @@ fn highlight_def(db: &RootDatabase, krate: Option<hir::Crate>, def: Definition)
 
                 h
             }
-            hir::ModuleDef::Trait(trait_) => {
-                let mut h = Highlight::new(HlTag::Symbol(SymbolKind::Trait));
-
-                if trait_.is_unsafe(db) {
-                    h |= HlMod::Unsafe;
-                }
-
-                h
-            }
+            hir::ModuleDef::Trait(_) => Highlight::new(HlTag::Symbol(SymbolKind::Trait)),
             hir::ModuleDef::TypeAlias(type_) => {
                 let mut h = Highlight::new(HlTag::Symbol(SymbolKind::TypeAlias));
 
diff --git a/crates/ide/src/syntax_highlighting/html.rs b/crates/ide/src/syntax_highlighting/html.rs
index 478facfee..21376a7ae 100644
--- a/crates/ide/src/syntax_highlighting/html.rs
+++ b/crates/ide/src/syntax_highlighting/html.rs
@@ -67,6 +67,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
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 a0ea1db34..4e85f7c0b 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
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html b/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html
index 921a956e6..79a285107 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlight_extern_crate.html b/crates/ide/src/syntax_highlighting/test_data/highlight_extern_crate.html
index ca9bb1e7d..13f589cc0 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_extern_crate.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_extern_crate.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
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 6202a03ce..50df376ae 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_injection.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_injection.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlight_strings.html b/crates/ide/src/syntax_highlighting/test_data/highlight_strings.html
index e860d713e..96cb09642 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_strings.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_strings.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
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 68165bdbf..55453468b 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_unsafe.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_unsafe.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
@@ -61,6 +62,11 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="field declaration">a</span><span class="colon">:</span> <span class="builtin_type">u16</span><span class="comma">,</span>
 <span class="brace">}</span>
 
+<span class="keyword unsafe">unsafe</span> <span class="keyword">trait</span> <span class="trait declaration unsafe">UnsafeTrait</span> <span class="brace">{</span><span class="brace">}</span>
+<span class="keyword unsafe">unsafe</span> <span class="keyword">impl</span> <span class="trait unsafe">UnsafeTrait</span> <span class="keyword">for</span> <span class="struct">Packed</span> <span class="brace">{</span><span class="brace">}</span>
+
+<span class="keyword">fn</span> <span class="function declaration">require_unsafe_trait</span><span class="angle">&lt;</span><span class="type_param declaration">T</span><span class="colon">:</span> <span class="trait">UnsafeTrait</span><span class="angle">&gt;</span><span class="parenthesis">(</span><span class="punctuation">_</span><span class="colon">:</span> <span class="type_param">T</span><span class="parenthesis">)</span> <span class="brace">{</span><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 associated declaration 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>
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlighting.html b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
index 59f1e8e4c..9232cf905 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlighting.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
diff --git a/crates/ide/src/syntax_highlighting/test_data/injection.html b/crates/ide/src/syntax_highlighting/test_data/injection.html
index 9ab46d05c..082837328 100644
--- a/crates/ide/src/syntax_highlighting/test_data/injection.html
+++ b/crates/ide/src/syntax_highlighting/test_data/injection.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
diff --git a/crates/ide/src/syntax_highlighting/test_data/rainbow_highlighting.html b/crates/ide/src/syntax_highlighting/test_data/rainbow_highlighting.html
index 666b0b228..763917714 100644
--- a/crates/ide/src/syntax_highlighting/test_data/rainbow_highlighting.html
+++ b/crates/ide/src/syntax_highlighting/test_data/rainbow_highlighting.html
@@ -15,6 +15,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .function.unsafe    { color: #BC8383; }
+.trait.unsafe       { color: #BC8383; }
 .operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
diff --git a/crates/ide/src/syntax_highlighting/tests.rs b/crates/ide/src/syntax_highlighting/tests.rs
index f7d8334a0..4f0b1ce85 100644
--- a/crates/ide/src/syntax_highlighting/tests.rs
+++ b/crates/ide/src/syntax_highlighting/tests.rs
@@ -527,6 +527,11 @@ struct Packed {
     a: u16,
 }
 
+unsafe trait UnsafeTrait {}
+unsafe impl UnsafeTrait for Packed {}
+
+fn require_unsafe_trait<T: UnsafeTrait>(_: T) {}
+
 trait DoTheAutoref {
     fn calls_autoref(&self);
 }
diff --git a/crates/syntax/src/ast/node_ext.rs b/crates/syntax/src/ast/node_ext.rs
index 3d27d2c1a..2bd9ad867 100644
--- a/crates/syntax/src/ast/node_ext.rs
+++ b/crates/syntax/src/ast/node_ext.rs
@@ -325,6 +325,15 @@ impl ast::Impl {
         let second = types.next();
         (first, second)
     }
+
+    pub fn for_trait_name_ref(name_ref: &ast::NameRef) -> Option<ast::Impl> {
+        let this = name_ref.syntax().ancestors().find_map(ast::Impl::cast)?;
+        if this.trait_()?.syntax().text_range().start() == name_ref.syntax().text_range().start() {
+            Some(this)
+        } else {
+            None
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]