Throw AbstractClassInstantiationError on abstract classes.

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

Index: pkg/front_end/lib/src/fasta/kernel/body_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index ea4771d823e0373e761f6590219f2a9449ed5f18..8170579211a924826df28ee643e03b5f7b3f868a 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -1682,6 +1682,7 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
       {bool isConst: false, int charOffset: -1}) {
     List<TypeParameter> typeParameters = target.function.typeParameters;
     if (target is Constructor) {
+      assert(!target.enclosingClass.isAbstract);
       typeParameters = target.enclosingClass.typeParameters;
     }
     if (!checkArguments(target.function, arguments, typeParameters)) {
@@ -1775,7 +1776,13 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
           // Not found. Reported below.
         } else if (b.isConstructor) {
           if (type.isAbstract) {
-            // TODO(ahe): Generate abstract instantiation error.
+            push(buildMethodInvocation(
+                buildAbstractClassInstantiationError(
+                    type.name, nameToken.charOffset),
+                callName,
+                arguments,
+                arguments.fileOffset));
+            return;
           } else {
             target = b.target;
           }
@@ -2352,8 +2359,16 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
     String message = formatUnexpected(uri, charOffset, error);
     Builder constructor = library.loader.getCompileTimeError();
     return new Throw(buildStaticInvocation(constructor.target,
-        new Arguments(<Expression>[new StringLiteral(message)]),
-        isConst: false)); // TODO(ahe): Make this const.
+        new Arguments(<Expression>[new StringLiteral(message)])));
+  }
+
+  Expression buildAbstractClassInstantiationError(String className,
+      [int charOffset = -1]) {
+    warning("The class '$className' is abstract and can't be instantiated.",
+        charOffset);
+    Builder constructor = library.loader.getAbstractClassInstantiationError();
+    return new Throw(buildStaticInvocation(constructor.target,
+        new Arguments(<Expression>[new StringLiteral(className)])));
   }
 
   Statement buildCompileTimeErrorStatement(error, [int charOffset = -1]) {