MalformedType used for all invalid type annotations.

sdk/lib/_internal/compiler/implementation/ssa/codegen.dart

Index: sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
diff --git a/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart b/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
index 202fb6e34606cd6c61706cfa16c3393d45d6146f..c494178f8f8d814007144579013c2cde27533736 100644
--- a/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
+++ b/sdk/lib/_internal/compiler/implementation/ssa/codegen.dart
@@ -2080,7 +2080,7 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
     });
     Element element = node.element;
     world.registerStaticUse(element);
-    ClassElement cls = element.getEnclosingClass();    
+    ClassElement cls = element.getEnclosingClass();
     if (element.isGenerativeConstructor()
         || (element.isFactoryConstructor() && cls == compiler.listClass)) {
       world.registerInstantiatedClass(cls);
@@ -2458,7 +2458,9 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
       "callTypeCheck":
           const SourceString("callTypeCast"),
       "propertyTypeCheck":
-          const SourceString("propertyTypeCast")
+          const SourceString("propertyTypeCast"),
+      "malformedTypeCheck":
+          const SourceString("malformedTypeCheck")
     };
 
     if (node.isChecked) {
@@ -2499,9 +2501,25 @@ abstract class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
       List<js.Expression> arguments = <js.Expression>[];
       use(node.checkedInput);
       arguments.add(pop());
-      if (helperElement.computeSignature(compiler).parameterCount != 1) {
+      int parameterCount =
+          helperElement.computeSignature(compiler).parameterCount;
+      if (parameterCount == 2) {
+        assert(!type.isMalformed);
         String additionalArgument = backend.namer.operatorIs(element);
         arguments.add(new js.LiteralString("'$additionalArgument'"));
+      } else if (parameterCount == 3) {
+        assert(type.isMalformed);
+        var reasons = new List<String>();
+        type.forEachMalformedType((MalformedType malformedType) {
+          ErroneousElement error = malformedType.element;
+          Message message = error.messageKind.message(error.messageArguments);
+          reasons.add(message.toString());
+          return true;
+        });
+        arguments.add(new js.LiteralString("'$type'"));
+        arguments.add(new js.LiteralString("'${Strings.join(reasons, ', ')}'"));
+      } else {
+        assert(!type.isMalformed);
       }
       String helperName = backend.namer.isolateAccess(helperElement);
       push(new js.Call(new js.VariableUse(helperName), arguments));