fix "unresolved names" code generation

pkg/dev_compiler/lib/src/compiler/code_generator.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:collection' show HashMap, HashSet;
 import 'dart:math' show min, max;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 2793 matching lines @@
     }
     return _callHelper('gbind(#, #)', [simpleId, typeArgs]);
   }
 
   /// Emits a simple identifier, handling implicit `this` as well as
   /// going through the qualified library name if necessary, but *not* handling
   /// inferred generic function instantiation.
   JS.Expression _emitSimpleIdentifier(SimpleIdentifier node) {
     var accessor = resolutionMap.staticElementForIdentifier(node);
     if (accessor == null) {
-      return js.commentExpression(
-          'Unimplemented unknown name', new JS.Identifier(node.name));
+      return _callHelper('throw("compile error: unresolved identifier: " + #)',
+          js.escapedString(node.name ?? '<null>'));
     }
 
     // Get the original declaring element. If we had a property accessor, this
     // indirects back to a (possibly synthetic) field.
     var element = accessor;
     if (accessor is PropertyAccessorElement) element = accessor.variable;
 
     // type literal
     if (element is TypeDefiningElement) {
       _declareBeforeUse(element);
@@ skipping 1268 matching lines @@
       ConstructorElement element,
       DartType type,
       SimpleIdentifier name,
       ArgumentList argumentList,
       bool isConst) {
     JS.Expression emitNew() {
       JS.Expression ctor;
       bool isFactory = false;
       bool isNative = false;
       if (element == null) {
-        // TODO(jmesserly): this only happens if we had a static error.
-        // Should we generate a throw instead?
-        ctor = _emitConstructorAccess(type,
-            nameType: options.hoistInstanceCreation,
-            hoistType: options.hoistInstanceCreation);
-        if (name != null) {
-          ctor = new JS.PropertyAccess(ctor, _propertyName(name.name));
-        }
+        ctor = _callHelper(
+            'throw("compile error: unresolved constructor: " + # + "." + #)', [
+          js.escapedString(type?.name ?? '<null>'),
+          js.escapedString(name?.name ?? '<unnamed>')
+        ]);
       } else {
         ctor = _emitConstructorName(element, type, name);
         isFactory = element.isFactory;
         var classElem = element.enclosingElement;
         isNative = _isJSNative(classElem);
       }
       var args = _emitArgumentList(argumentList);
       // Native factory constructors are JS constructors - use new here.
       return isFactory && !isNative
           ? new JS.Call(ctor, args)
@@ skipping 1869 matching lines @@
   if (targetIdentifier.staticElement is! PrefixElement) return false;
   var prefix = targetIdentifier.staticElement as PrefixElement;
 
   // The library the prefix is referring to must come from a deferred import.
   var containingLibrary = resolutionMap
       .elementDeclaredByCompilationUnit(target.root as CompilationUnit)
       .library;
   var imports = containingLibrary.getImportsWithPrefix(prefix);
   return imports.length == 1 && imports[0].isDeferred;
 }