[DAS] Fixes false-positive on comment references for unnecessary_underscores

Fixes: #61558
Change-Id: I813e4390521c31660776b12c6cd0792f779ff675
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/464627
Auto-Submit: Felipe Morschel <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Samuel Rawlins <[email protected]>

Author: FMorschel

pkg/linter/lib/src/rules/unnecessary_underscores.dart

@@ -56,7 +56,13 @@ class _Visitor extends SimpleAstVisitor<void> {
 
   @override
   void visitFormalParameterList(FormalParameterList node) {
-    late Set<Element> referencedElements = collectReferences(node.parent);
+    late Set<Element> referencedElements = {
+      ...collectReferences(node.parent),
+      if (node.parent?.parent case FunctionDeclaration(
+        :var documentationComment,
+      ))
+        ...collectReferences(documentationComment),
+    };
 
     for (var parameter in node.parameters) {
       var parameterName = parameter.name;

pkg/linter/test/rules/unnecessary_underscores_test.dart

@@ -17,6 +17,22 @@ class UnnecessaryUnderscoresTest extends LintRuleTest {
   @override
   String get lintRule => 'unnecessary_underscores';
 
+  test_commentReferenceFunction() async {
+    await assertNoDiagnostics('''
+/// This is a reference to [__].
+void f(int __) {}
+''');
+  }
+
+  test_commentReferenceMethod() async {
+    await assertNoDiagnostics('''
+class C {
+  /// This is a reference to [__].
+  void m(int __) {}
+}
+''');
+  }
+
   test_enum_field_unused() async {
     await assertNoDiagnostics(r'''
 enum E {