dart2js cps_ir: Use interceptors for is-checks (version 2)

pkg/compiler/lib/src/js_backend/codegen/codegen.dart

Index: pkg/compiler/lib/src/js_backend/codegen/codegen.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/codegen.dart b/pkg/compiler/lib/src/js_backend/codegen/codegen.dart
index 963f1d7f43ae700436985490c217268f38209910..feafe06bc0ef16df526061fec7eea72e64785e62 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/codegen.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/codegen.dart
@@ -357,18 +357,6 @@ class CodeGenerator extends tree_ir.StatementVisitor
       glue.registerIsCheck(type, registry);
       ClassElement clazz = type.element;
 
-      // Handle some special checks against classes that exist only in
-      // the compile-time class hierarchy, not at runtime.
-      // TODO(sra): Is this correct? The field tests are only valid with the
-      // precondition that [value] is an Array. They will crash on `null`.
-      if (clazz == glue.jsExtendableArrayClass) {
-        assert(node.isTypeTest);
-        return js.js(r'!#.fixed$length', <js.Expression>[value]);
-      } else if (clazz == glue.jsMutableArrayClass) {
-        assert(node.isTypeTest);
-        return js.js(r'!#.immutable$list', <js.Expression>[value]);
-      }
-
       if (glue.isStringClass(clazz)) {
         if (node.isTypeTest) {
           return js.js(r'typeof # === "string"', <js.Expression>[value]);
@@ -428,6 +416,16 @@ class CodeGenerator extends tree_ir.StatementVisitor
   }
 
   @override
+  js.Expression visitGetTypeTestProperty(tree_ir.GetTypeTestProperty node) {
+    js.Expression object = visitExpression(node.object);
+    DartType dartType = node.dartType;
+    assert(dartType.isInterfaceType);
+    glue.registerIsCheck(dartType, registry);
+    js.Expression property = glue.getTypeTestTag(dartType);
+    return js.js(r'#.#', [object, property]);
+  }
+
+  @override
   js.Expression visitVariableUse(tree_ir.VariableUse node) {
     return buildVariableAccess(node.variable);
   }
@@ -819,11 +817,13 @@ class CodeGenerator extends tree_ir.StatementVisitor
   @override
   js.Expression visitTypeExpression(tree_ir.TypeExpression node) {
     List<js.Expression> arguments = visitExpressionList(node.arguments);
-    return glue.generateTypeRepresentation(node.dartType, arguments);
+    return glue.generateTypeRepresentation(node.dartType, arguments, registry);
   }
 
   js.Node handleForeignCode(tree_ir.ForeignCode node) {
     registry.registerStaticUse(node.dependency);
+    // TODO(sra): Should this be in CodegenRegistry?
+    glue.registerNativeBehavior(node.nativeBehavior, node);
     return node.codeTemplate.instantiate(visitExpressionList(node.arguments));
   }
 
@@ -893,6 +893,16 @@ class CodeGenerator extends tree_ir.StatementVisitor
         return js.js('Math.floor(#) === #', args);
       case BuiltinOperator.IsNumberAndFloor:
         return js.js('typeof # === "number" && Math.floor(#) === #', args);
+      case BuiltinOperator.IsFixedLengthJSArray:
+        // TODO(sra): Remove boolify (i.e. !!).
+        return js.js(r'!!#.fixed$length', args);
+      case BuiltinOperator.IsExtendableJSArray:
+        return js.js(r'!#.fixed$length', args);
+      case BuiltinOperator.IsModifiableJSArray:
+        return js.js(r'!#.immutable$list', args);
+      case BuiltinOperator.IsUnmodifiableJSArray:
+        // TODO(sra): Remove boolify (i.e. !!).
+        return js.js(r'!!#.immutable$list', args);
     }
   }