Fix for resynthesizing invalid @functionName() annotations.

It should not cause an exception and resolution failure.

R=paulberry@google.com
BUG= https://github.com/dart-lang/sdk/issues/28099

Review-Url: https://codereview.chromium.org/2565173008 .

pkg/analyzer/lib/src/summary/resynthesize.dart

@@ -308,6 +308,8 @@ abstract class SummaryResynthesizer extends ElementResynthesizer {
  * Builder of [Expression]s from [UnlinkedExpr]s.
  */
 class _ConstExprBuilder {
+  static const ARGUMENT_LIST = 'ARGUMENT_LIST';
+
   final _UnitResynthesizer resynthesizer;
   final ElementImpl context;
   final UnlinkedExpr uc;
@@ -651,8 +653,12 @@ class _ConstExprBuilder {
       } else if (info.element is ClassElement) {
         constructorName = null;
       } else {
-        throw new StateError('Unsupported element for invokeConstructor '
-            '${info.element?.runtimeType}');
+        List<Expression> arguments = _buildArguments();
+        SimpleIdentifier name = AstTestFactory.identifier3(info.name);
+        name.staticElement = info.element;
+        name.setProperty(ARGUMENT_LIST, AstTestFactory.argumentList(arguments));
+        _push(name);
+        return;
       }
       InterfaceType definingType = resynthesizer._createConstructorDefiningType(
           context?.typeParameterContext, info, ref.typeArguments);
@@ -1530,8 +1536,11 @@ class _UnitResynthesizer {
     ElementAnnotationImpl elementAnnotation = new ElementAnnotationImpl(unit);
     Expression constExpr = _buildConstExpression(context, uc);
     if (constExpr is Identifier) {
+      ArgumentList arguments =
+          constExpr.getProperty(_ConstExprBuilder.ARGUMENT_LIST);
       elementAnnotation.element = constExpr.staticElement;
-      elementAnnotation.annotationAst = AstTestFactory.annotation(constExpr);
+      elementAnnotation.annotationAst =
+          AstTestFactory.annotation2(constExpr, null, arguments);
     } else if (constExpr is InstanceCreationExpression) {
       elementAnnotation.element = constExpr.staticElement;
       Identifier typeName = constExpr.constructorName.type.name;

pkg/analyzer/test/src/dart/analysis/driver_test.dart

@@ -653,6 +653,23 @@ class B extends A {
     expect(_getClassMethodReturnType(result.unit, 'B', 'm'), 'int');
   }
 
+  test_getResult_invalid_annotation_functionAsConstructor() async {
+    addTestFile(
+        r'''
+fff() {}
+
+@fff()
+class C {}
+''',
+        priority: true);
+
+    AnalysisResult result = await driver.getResult(testFile);
+    ClassDeclaration c = result.unit.declarations[1] as ClassDeclaration;
+    Annotation a = c.metadata[0];
+    expect(a.name.name, 'fff');
+    expect(a.name.staticElement, new isInstanceOf<FunctionElement>());
+  }
+
   test_getResult_invalidUri_exports_dart() async {
     String content = r'''
 export 'dart:async';

pkg/analyzer/test/src/summary/resynthesize_common.dart

@@ -4065,6 +4065,10 @@ class C {
     checkLibrary('@a import "foo.dart"; const a = b;');
   }
 
+  test_metadata_invalid_classDeclaration() {
+    checkLibrary('f(_) {} @f(42) class C {}');
+  }
+
   test_metadata_libraryDirective() {
     checkLibrary('@a library L; const a = null;');
   }