cps_ir: Add JS checks, use argument nullability

pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart

 // Copyright (c) 2013, 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.
 
 library dart2js.ir_builder_task;
 
 import '../closure.dart' as closurelib;
 import '../closure.dart' hide ClosureScope;
 import '../common.dart';
 import '../common/names.dart' show
@@ skipping 25 matching lines @@
     TypeMask;
 import '../universe/call_structure.dart' show
     CallStructure;
 import '../universe/selector.dart' show
     Selector;
 import '../constants/values.dart' show
     ConstantValue;
 import 'cps_ir_nodes.dart' as ir;
 import 'cps_ir_builder.dart';
 import '../native/native.dart' show
-    NativeBehavior;
+    NativeBehavior,
+    HasCapturedPlaceholders;
 
 // TODO(karlklose): remove.
 import '../js/js.dart' as js show js, Template, Expression, Name;
 import '../ssa/ssa.dart' show TypeMaskFactory;
 import '../util/util.dart';
 
 import 'package:js_runtime/shared/embedded_names.dart'
     show JsBuiltin, JsGetName;
 import '../constants/values.dart';
 import 'type_mask_system.dart' show
@@ skipping 3425 matching lines @@
     NativeBehavior behavior =
         compiler.enqueuer.resolution.nativeEnqueuer.getNativeBehaviorOf(node);
     switch (function.name) {
       case 'JS':
         validateArgumentCount(minimum: 2);
         // The first two arguments are the type and the foreign code template,
         // which already have been analyzed by the resolver and can be retrieved
         // using [NativeBehavior]. We can ignore these arguments in the backend.
         List<ir.Primitive> arguments =
             argumentNodes.skip(2).mapToList(visit, growable: false);
+        if (behavior.codeTemplate.positionalArgumentCount != arguments.length) {
+          reporter.reportErrorMessage(
+              node, MessageKind.GENERIC,
+              {'text':
+                'Mismatch between number of placeholders'
+                ' and number of arguments.'});
+          return irBuilder.buildNullConstant();
+        }
+
+        if (HasCapturedPlaceholders.check(behavior.codeTemplate.ast)) {
+          reporter.reportErrorMessage(node, MessageKind.JS_PLACEHOLDER_CAPTURE);
+          return irBuilder.buildNullConstant();
+        }
+
         return irBuilder.buildForeignCode(behavior.codeTemplate, arguments,
             behavior);
 
       case 'DART_CLOSURE_TO_JS':
         // TODO(ahe): This should probably take care to wrap the closure in
         // another closure that saves the current isolate.
       case 'RAW_DART_FUNCTION_REF':
         validateArgumentCount(exactly: 1);
 
         ast.Node argument = node.arguments.single;
@@ skipping 150 matching lines @@
       callStructure = translateStaticArguments(argumentsNode, function,
           callStructure, arguments);
       return irBuilder.buildStaticFunctionInvocation(function,
           callStructure,
           arguments,
           sourceInformation:
               sourceInformationBuilder.buildCall(node, node.selector));
     }
   }
 }