dart2js: emit tear-offs in new emitter.

pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart

Index: pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart b/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
index d13108a3a767d5860f8f4e4d3794776291687681..7953b438e8c783029be3d766cec78d64b6e84f3e 100644
--- a/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
@@ -22,7 +22,7 @@ import 'package:_internal/compiler/js_lib/shared/embedded_names.dart' show
     METADATA,
     TYPE_TO_INTERCEPTOR_MAP;
 
-import '../js_emitter.dart' show NativeGenerator;
+import '../js_emitter.dart' show NativeGenerator, buildTearOffCode;
 import '../model.dart';
 
 class ModelEmitter {
@@ -108,6 +108,9 @@ class ModelEmitter {
         boilerplate,
         {'deferredInitializer': emitDeferredInitializerGlobal(program.loadMap),
          'holders': emitHolders(fragment.holders),
+         'tearOff': buildTearOffCode(backend),
+         'parseFunctionDescriptor':
+           js.js.statement(parseFunctionDescriptorBoilerplate),
          'cyclicThrow':
            backend.emitter.staticFunctionAccess(backend.getCyclicThrowHelper()),
          'outputContainsConstantList': program.outputContainsConstantList,
@@ -395,19 +398,12 @@ class ModelEmitter {
     } else {
       elements.add(_generateConstructor(cls));
     }
-    Iterable<Method> methods = cls.methods.expand((Method method) {
-      // TODO(floitsch): can there be anything else than a DartMethod?
-      if (method is DartMethod) {
-        return [method]..addAll(method.parameterStubs);
-      } else {
-        return [method];
-      }
-    });
+    Iterable<Method> methods = cls.methods;
     Iterable<Method> isChecks = cls.isChecks;
     Iterable<Method> gettersSetters = _generateGettersSetters(cls);
     Iterable<Method> allMethods =
         [methods, isChecks, gettersSetters].expand((x) => x);
-    elements.addAll(allMethods.expand((e) => [js.string(e.name), e.code]));
+    elements.addAll(allMethods.expand(emitInstanceMethod));
     return unparse(compiler, new js.ArrayInitializer(elements));
   }
 
@@ -416,6 +412,67 @@ class ModelEmitter {
     return unparse(compiler, field.code);
   }
 
+  static final String parseFunctionDescriptorBoilerplate = r"""
+function parseFunctionDescriptor(proto, name, desc) {
+  if (desc instanceof Array) {

[zarah, 2015/02/02 08:20:10]

It would be nice with a comment here describing the encoding or a pointer to
somewhere else where it is described.

+    proto[name] = desc[0];
+    var funs = [desc[0]];
+    funs[0].$callName = desc[1];
+    for (var pos = 4; pos < desc.length; pos += 3) {
+      var stub = desc[pos+2];
+      stub.$callName = desc[pos+1];
+      proto[desc[pos]] = stub;
+      funs.push(stub);
+    }
+    if (desc[2] != null) {
+      // TODO(floitsch): desc[3] should be the reflectionInfo, not
+      // isIntercepted.
+      var isIntercepted = desc[3];
+      var reflectionInfo = null;
+      proto[desc[2]] = tearOff(funs, reflectionInfo, false, name, isIntercepted);
+    }
+  } else {
+    proto[name] = desc;
+  }
+}
+""";
+
+  Iterable<js.Expression> emitInstanceMethod(Method method) {
+
+    List<js.Expression> makeNameCodePair(Method method) {
+      return [js.string(method.name), method.code];
+    }
+
+    List<js.Expression> makeNameCallNameCodeTriplet(ParameterStubMethod stub) {
+      js.Expression callName = stub.callName == null
+          ? new js.LiteralNull()
+          : js.string(stub.callName);
+      return [js.string(stub.name), callName, stub.code];
+    }
+
+    if (method is DartMethod) {
+      if (method.needsTearOff) {
+        bool isIntercepted = backend.isInterceptedMethod(method.element);
+        // [name, [function, callName, tearOffName, functionType,
+        //     stub1_name, stub1_callName, stub1_code, ...]
+        var data = [method.code];
+        data.add(js.string(method.callName));
+        data.add(js.string(method.tearOffName));
+        // TODO(floitsch): this field should be the type, not the bool if the
+        // method is intercepted.
+        // data.add(new js.LiteralNull());
+        data.add(new js.LiteralBool(isIntercepted));
+        data.addAll(method.parameterStubs.expand(makeNameCallNameCodeTriplet));
+        return [js.string(method.name), new js.ArrayInitializer(data)];
+      } else {
+        // TODO(floitsch): not the most efficient way...
+        return ([method]..addAll(method.parameterStubs)).expand(makeNameCodePair);

[zarah, 2015/02/02 08:20:11]

long line.

+      }
+    } else {
+      return makeNameCodePair(method);
+    }
+  }
+
   Iterable<js.Expression> emitStaticMethod(StaticMethod method) {
     js.Expression holderIndex = js.number(method.holder.index);
     List<js.Expression> output = <js.Expression>[];
@@ -441,7 +498,7 @@ class ModelEmitter {
 #deferredInitializer;
 
 !function(start, program) {
-
+  var functionCounter = 0;
   // Initialize holder objects.
   #holders;
 
@@ -530,6 +587,10 @@ class ModelEmitter {
     holder[name] = patch;
   }
 
+  #tearOff;
+
+  #parseFunctionDescriptor;
+
   function compileConstructor(name, descriptor) {
     descriptor = compile(name, descriptor);
     var prototype = determinePrototype(descriptor);
@@ -538,12 +599,12 @@ class ModelEmitter {
     if (typeof descriptor[2] !== 'function') {
       constructor = compileMixinConstructor(name, prototype, descriptor);
       for (var i = 4; i < descriptor.length; i += 2) {
-        prototype[descriptor[i]] = descriptor[i + 1];
+        parseFunctionDescriptor(prototype, descriptor);
       }
     } else {
       constructor = descriptor[2];
       for (var i = 3; i < descriptor.length; i += 2) {
-        prototype[descriptor[i]] = descriptor[i + 1];
+        parseFunctionDescriptor(prototype, descriptor[i], descriptor[i+1]);
       }
     }
     constructor.builtin\$cls = name;  // Needed for RTI.