Revert "Generate tear-off closures dynamically."

dart/sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.dart

Index: dart/sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.dart b/dart/sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.dart
index 1ebb578d2635a53beb60969f7b8d5d76255c2bab..b8e8210ab1136caf110312b00277963789a796ed 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.dart
@@ -25,7 +25,7 @@ class ContainerBuilder extends CodeEmitterHelper {
    */
   void addParameterStub(FunctionElement member,
                         Selector selector,
-                        AddStubFunction addStub,
+                        DefineStubFunction defineStub,
                         Set<String> alreadyGenerated) {
     FunctionSignature parameters = member.computeSignature(compiler);
     int positionalArgumentCount = selector.positionalArgumentCount;
@@ -81,7 +81,10 @@ class ContainerBuilder extends CodeEmitterHelper {
 
     int parameterIndex = 0;
     parameters.orderedForEachParameter((Element element) {
-      String jsName = backend.namer.safeName(element.name);
+      // Use generic names for closures to facilitate code sharing.
+      String jsName = member is ClosureInvocationElement
+          ? 'p${parameterIndex++}'
+          : backend.namer.safeName(element.name);
       assert(jsName != receiverArgumentName);
       if (count < optionalParameterStart) {
         parametersBuffer[count] = new jsAst.Parameter(jsName);
@@ -118,30 +121,25 @@ class ContainerBuilder extends CodeEmitterHelper {
           member, isInterceptedMethod, invocationName,
           parametersBuffer, argumentsBuffer,
           indexOfLastOptionalArgumentInParameters);
-    } else if (member.isInstanceMember()) {
+    } else {
       body = [js.return_(
           js('this')[namer.getNameOfInstanceMember(member)](argumentsBuffer))];
-    } else {
-      body = [js.return_(namer.elementAccess(member)(argumentsBuffer))];
     }
 
     jsAst.Fun function = js.fun(parametersBuffer, body);
 
-    addStub(selector, function);
-  }
+    defineStub(invocationName, function);
 
-  void addParameterStubs(FunctionElement member, AddStubFunction defineStub,
-                         [bool canTearOff = false]) {
-    if (member.enclosingElement.isClosure()) {
-      ClosureClassElement cls = member.enclosingElement;
-      if (cls.supertype.element == compiler.boundClosureClass) {
-        compiler.internalErrorOnElement(cls.methodElement, 'Bound closure1.');
-      }
-      if (cls.methodElement.isInstanceMember()) {
-        compiler.internalErrorOnElement(cls.methodElement, 'Bound closure2.');
-      }
+    String reflectionName = task.getReflectionName(selector, invocationName);
+    if (reflectionName != null) {
+      var reflectable =
+          js(backend.isAccessibleByReflection(member) ? '1' : '0');
+      defineStub('+$reflectionName', reflectable);
     }
+  }
 
+  void addParameterStubs(FunctionElement member,
+                         DefineStubFunction defineStub) {
     // We fill the lists depending on the selector. For example,
     // take method foo:
     //    foo(a, b, {c, d});
@@ -167,59 +165,331 @@ class ContainerBuilder extends CodeEmitterHelper {
     // (4) No stub generated, call is direct.
     // (5) No stub generated, call is direct.
 
-    Set<Selector> selectors = member.isInstanceMember()
-        ? compiler.codegenWorld.invokedNames[member.name]
-        : null; // No stubs needed for static methods.
-
-    /// Returns all closure call selectors renamed to match this member.
-    Set<Selector> callSelectorsAsNamed() {
-      if (!canTearOff) return null;
-      Set<Selector> callSelectors = compiler.codegenWorld.invokedNames[
-          namer.closureInvocationSelectorName];
-      if (callSelectors == null) return null;
-      return callSelectors.map((Selector callSelector) {
-        return new Selector.call(
-            member.name, member.getLibrary(),
-            callSelector.argumentCount, callSelector.namedArguments);
-      }).toSet();
-    }
-    if (selectors == null) {
-      selectors = callSelectorsAsNamed();
-      if (selectors == null) return;
+    // Keep a cache of which stubs have already been generated, to
+    // avoid duplicates. Note that even if selectors are
+    // canonicalized, we would still need this cache: a typed selector
+    // on A and a typed selector on B could yield the same stub.
+    Set<String> generatedStubNames = new Set<String>();
+    bool isClosureInvocation =
+        member.name == namer.closureInvocationSelectorName;
+    if (backend.isNeededForReflection(member) ||
+        (compiler.enabledFunctionApply && isClosureInvocation)) {
+      // If [Function.apply] is called, we pessimistically compile all
+      // possible stubs for this closure.
+      FunctionSignature signature = member.computeSignature(compiler);
+      Set<Selector> selectors = signature.optionalParametersAreNamed
+          ? computeSeenNamedSelectors(member)
+          : computeOptionalSelectors(signature, member);
+      for (Selector selector in selectors) {
+        addParameterStub(member, selector, defineStub, generatedStubNames);
+      }
+      if (signature.optionalParametersAreNamed && isClosureInvocation) {
+        addCatchAllParameterStub(member, signature, defineStub);
+      }
     } else {
-      Set<Selector> callSelectors = callSelectorsAsNamed();
-      if (callSelectors != null) {
-        selectors = selectors.union(callSelectors);
+      Set<Selector> selectors = compiler.codegenWorld.invokedNames[member.name];
+      if (selectors == null) return;
+      for (Selector selector in selectors) {
+        if (!selector.applies(member, compiler)) continue;
+        addParameterStub(member, selector, defineStub, generatedStubNames);
       }
     }
-    Set<Selector> untypedSelectors = new Set<Selector>();
-    if (selectors != null) {
-      for (Selector selector in selectors) {
-        if (!selector.appliesUnnamed(member, compiler)) continue;
-        if (untypedSelectors.add(selector.asUntyped)) {
-          // TODO(ahe): Is the last argument to [addParameterStub] needed?
-          addParameterStub(member, selector, defineStub, new Set<String>());
-        }
+  }
+
+  Set<Selector> computeSeenNamedSelectors(FunctionElement element) {
+    Set<Selector> selectors = compiler.codegenWorld.invokedNames[element.name];
+    Set<Selector> result = new Set<Selector>();
+    if (selectors == null) return result;
+    for (Selector selector in selectors) {
+      if (!selector.applies(element, compiler)) continue;
+      result.add(selector);
+    }
+    return result;
+  }
+
+  void addCatchAllParameterStub(FunctionElement member,
+                                FunctionSignature signature,
+                                DefineStubFunction defineStub) {
+    // See Primities.applyFunction in js_helper.dart for details.
+    List<jsAst.Property> properties = <jsAst.Property>[];
+    for (Element element in signature.orderedOptionalParameters) {
+      String jsName = backend.namer.safeName(element.name);
+      Constant value = compiler.constantHandler.initialVariableValues[element];
+      jsAst.Expression reference = null;
+      if (value == null) {
+        reference = new jsAst.LiteralNull();
+      } else {
+        reference = task.constantReference(value);
       }
+      properties.add(new jsAst.Property(js.string(jsName), reference));
     }
-    if (canTearOff) {
-      selectors = compiler.codegenWorld.invokedNames[
-          namer.closureInvocationSelectorName];
-      if (selectors != null) {
-        for (Selector selector in selectors) {
-          selector = new Selector.call(
-              member.name, member.getLibrary(),
-              selector.argumentCount, selector.namedArguments);
-          if (!selector.appliesUnnamed(member, compiler)) continue;
-          if (untypedSelectors.add(selector)) {
-            // TODO(ahe): Is the last argument to [addParameterStub] needed?
-            addParameterStub(member, selector, defineStub, new Set<String>());
-          }
-        }
+    defineStub(
+        backend.namer.callCatchAllName,
+        js.fun([], js.return_(new jsAst.ObjectInitializer(properties))));
+  }
+
+  /**
+   * Compute the set of possible selectors in the presence of optional
+   * non-named parameters.
+   */
+  Set<Selector> computeOptionalSelectors(FunctionSignature signature,
+                                         FunctionElement element) {
+    Set<Selector> selectors = new Set<Selector>();
+    // Add the selector that does not have any optional argument.
+    selectors.add(new Selector(SelectorKind.CALL,
+                               element.name,
+                               element.getLibrary(),
+                               signature.requiredParameterCount,
+                               <String>[]));
+
+    // For each optional parameter, we increment the number of passed
+    // argument.
+    for (int i = 1; i <= signature.optionalParameterCount; i++) {
+      selectors.add(new Selector(SelectorKind.CALL,
+                                 element.name,
+                                 element.getLibrary(),
+                                 signature.requiredParameterCount + i,
+                                 <String>[]));
+    }
+    return selectors;
+  }
+
+  void emitStaticFunctionGetters(CodeBuffer eagerBuffer) {
+    task.addComment('Static function getters', task.mainBuffer);
+    for (FunctionElement element in
+             Elements.sortedByPosition(staticGetters.keys)) {
+      Element closure = staticGetters[element];
+      CodeBuffer buffer =
+          task.isDeferred(element) ? task.deferredConstants : eagerBuffer;
+      String closureClass = namer.isolateAccess(closure);
+      String name = namer.getStaticClosureName(element);
+
+      String closureName = namer.getStaticClosureName(element);
+      jsAst.Node assignment = js(
+          'init.globalFunctions["$closureName"] ='
+          ' ${namer.globalObjectFor(element)}.$name ='
+          ' new $closureClass(#, "$closureName")',
+          namer.elementAccess(element));
+      buffer.write(jsAst.prettyPrint(assignment, compiler));
+      buffer.write('$N');
+    }
+  }
+
+  void emitStaticFunctionClosures() {
+    Set<FunctionElement> functionsNeedingGetter =
+        compiler.codegenWorld.staticFunctionsNeedingGetter;
+    for (FunctionElement element in
+             Elements.sortedByPosition(functionsNeedingGetter)) {
+      String superName = namer.getNameOfClass(compiler.closureClass);
+      int parameterCount = element.functionSignature.parameterCount;
+      String name = 'Closure\$$parameterCount';
+      assert(task.instantiatedClasses.contains(compiler.closureClass));
+
+      ClassElement closureClassElement = new ClosureClassElement(
+          null, name, compiler, element,
+          element.getCompilationUnit());
+      // Now add the methods on the closure class. The instance method does not
+      // have the correct name. Since [addParameterStubs] use the name to create
+      // its stubs we simply create a fake element with the correct name.
+      // Note: the callElement will not have any enclosingElement.
+      FunctionElement callElement =
+          new ClosureInvocationElement(namer.closureInvocationSelectorName,
+                                       element);
+
+      String invocationName = namer.instanceMethodName(callElement);
+      String mangledName = namer.getNameOfClass(closureClassElement);
+
+      // Define the constructor with a name so that Object.toString can
+      // find the class name of the closure class.
+      ClassBuilder closureBuilder = new ClassBuilder();
+      // If a static function is used as a closure we need to add its name
+      // in case it is used in spawnFunction.
+      String methodName = namer.STATIC_CLOSURE_NAME_NAME;
+      List<String> fieldNames = <String>[invocationName, methodName];
+      closureBuilder.addProperty('',
+          js.string("$superName;${fieldNames.join(',')}"));
+
+      addParameterStubs(callElement, closureBuilder.addProperty);
+
+      void emitFunctionTypeSignature(Element method, FunctionType methodType) {
+        RuntimeTypes rti = backend.rti;
+        // [:() => null:] is dummy encoding of [this] which is never needed for
+        // the encoding of the type of the static [method].
+        jsAst.Expression encoding =
+            rti.getSignatureEncoding(methodType, js('null'));
+        String operatorSignature = namer.operatorSignature();
+        // TODO(johnniwinther): Make MiniJsParser support function expressions.
+        closureBuilder.addProperty(operatorSignature, encoding);
       }
+
+      FunctionType methodType = element.computeType(compiler);
+      Map<FunctionType, bool> functionTypeChecks =
+          task.typeTestEmitter.getFunctionTypeChecksOn(methodType);
+      task.typeTestEmitter.generateFunctionTypeTests(
+          element, methodType, functionTypeChecks,
+          emitFunctionTypeSignature);
+
+      closureClassElement =
+          addClosureIfNew(closureBuilder, closureClassElement, fieldNames);
+      staticGetters[element] = closureClassElement;
+
     }
   }
 
+  ClassElement addClosureIfNew(ClassBuilder builder,
+                               ClassElement closure,
+                               List<String> fieldNames) {
+    String key =
+        jsAst.prettyPrint(builder.toObjectInitializer(), compiler).getText();
+    return methodClosures.putIfAbsent(key, () {
+      String mangledName = namer.getNameOfClass(closure);
+      emitClosureInPrecompiledFunction(mangledName, fieldNames);
+      return closure;
+    });
+  }
+
+  void emitClosureInPrecompiledFunction(String mangledName,
+                                        List<String> fieldNames) {
+    List<String> fields = fieldNames;
+    String constructorName = mangledName;
+    task.precompiledFunction.add(new jsAst.FunctionDeclaration(
+        new jsAst.VariableDeclaration(constructorName),
+        js.fun(fields, fields.map(
+            (name) => js('this.$name = $name')).toList())));
+    task.precompiledFunction.addAll([
+        js('$constructorName.builtin\$cls = "$constructorName"'),
+        js('\$desc=\$collectedClasses.$constructorName'),
+        js.if_('\$desc instanceof Array', js('\$desc = \$desc[1]')),
+        js('$constructorName.prototype = \$desc'),
+    ]);
+
+    task.precompiledConstructorNames.add(js(constructorName));
+  }
+
+  /**
+   * Documentation wanted -- johnniwinther
+   *
+   * Invariant: [member] must be a declaration element.
+   */
+  void emitDynamicFunctionGetter(FunctionElement member,
+                                 DefineStubFunction defineStub) {
+    assert(invariant(member, member.isDeclaration));
+    assert(task.instantiatedClasses.contains(compiler.boundClosureClass));
+    // For every method that has the same name as a property-get we create a
+    // getter that returns a bound closure. Say we have a class 'A' with method
+    // 'foo' and somewhere in the code there is a dynamic property get of
+    // 'foo'. Then we generate the following code (in pseudo Dart/JavaScript):
+    //
+    // class A {
+    //    foo(x, y, z) { ... } // Original function.
+    //    get foo { return new BoundClosure499(this, "foo"); }
+    // }
+    // class BoundClosure499 extends BoundClosure {
+    //   BoundClosure499(this.self, this.name);
+    //   $call3(x, y, z) { return self[name](x, y, z); }
+    // }
+
+    bool hasOptionalParameters = member.optionalParameterCount(compiler) != 0;
+    int parameterCount = member.parameterCount(compiler);
+
+    // Intercepted methods take an extra parameter, which is the
+    // receiver of the call.
+    bool inInterceptor = backend.isInterceptedMethod(member);
+    List<String> fieldNames = <String>[];
+    compiler.boundClosureClass.forEachInstanceField((_, Element field) {
+      fieldNames.add(namer.instanceFieldPropertyName(field));
+    });
+
+    ClassElement classElement = member.getEnclosingClass();
+    String name = inInterceptor
+        ? 'BoundClosure\$i${parameterCount}'
+        : 'BoundClosure\$${parameterCount}';
+
+    ClassElement closureClassElement = new ClosureClassElement(
+        null, name, compiler, member,
+        member.getCompilationUnit());
+    String superName = namer.getNameOfClass(closureClassElement.superclass);
+
+    // Define the constructor with a name so that Object.toString can
+    // find the class name of the closure class.
+    ClassBuilder boundClosureBuilder = new ClassBuilder();
+    boundClosureBuilder.addProperty('',
+        js.string("$superName;${fieldNames.join(',')}"));
+    // Now add the methods on the closure class. The instance method does not
+    // have the correct name. Since [addParameterStubs] use the name to create
+    // its stubs we simply create a fake element with the correct name.
+    // Note: the callElement will not have any enclosingElement.
+    FunctionElement callElement = new ClosureInvocationElement(
+        namer.closureInvocationSelectorName, member);
+
+    String invocationName = namer.instanceMethodName(callElement);
+
+    List<String> parameters = <String>[];
+    List<jsAst.Expression> arguments =
+        <jsAst.Expression>[js('this')[fieldNames[0]]];
+    if (inInterceptor) {
+      arguments.add(js('this')[fieldNames[2]]);
+    }
+    for (int i = 0; i < parameterCount; i++) {
+      String name = 'p$i';
+      parameters.add(name);
+      arguments.add(js(name));
+    }
+
+    jsAst.Expression fun = js.fun(
+        parameters,
+        js.return_(
+            js('this')[fieldNames[1]]['call'](arguments)));
+    boundClosureBuilder.addProperty(invocationName, fun);
+
+    addParameterStubs(callElement, boundClosureBuilder.addProperty);
+
+    void emitFunctionTypeSignature(Element method, FunctionType methodType) {
+      jsAst.Expression encoding = backend.rti.getSignatureEncoding(
+          methodType, js('this')[fieldNames[0]]);
+      String operatorSignature = namer.operatorSignature();
+      boundClosureBuilder.addProperty(operatorSignature, encoding);
+    }
+
+    DartType memberType = member.computeType(compiler);
+    Map<FunctionType, bool> functionTypeChecks =
+        task.typeTestEmitter.getFunctionTypeChecksOn(memberType);
+
+    task.typeTestEmitter.generateFunctionTypeTests(
+        member, memberType, functionTypeChecks,
+        emitFunctionTypeSignature);
+
+    closureClassElement =
+        addClosureIfNew(boundClosureBuilder, closureClassElement, fieldNames);
+
+    String closureClass = namer.isolateAccess(closureClassElement);
+
+    // And finally the getter.
+    String getterName = namer.getterName(member);
+    String targetName = namer.instanceMethodName(member);
+
+    parameters = <String>[];
+    jsAst.PropertyAccess method =
+        backend.namer.elementAccess(classElement)['prototype'][targetName];
+    arguments = <jsAst.Expression>[js('this'), method];
+
+    if (inInterceptor) {
+      String receiverArg = fieldNames[2];
+      parameters.add(receiverArg);
+      arguments.add(js(receiverArg));
+    } else {
+      // Put null in the intercepted receiver field.
+      arguments.add(new jsAst.LiteralNull());
+    }
+
+    arguments.add(js.string(targetName));
+
+    jsAst.Expression getterFunction = js.fun(
+        parameters, js.return_(js(closureClass).newWith(arguments)));
+
+    defineStub(getterName, getterFunction);
+  }
+
   /**
    * Documentation wanted -- johnniwinther
    *
@@ -227,7 +497,7 @@ class ContainerBuilder extends CodeEmitterHelper {
    */
   void emitCallStubForGetter(Element member,
                              Set<Selector> selectors,
-                             AddPropertyFunction addProperty) {
+                             DefineStubFunction defineStub) {
     assert(invariant(member, member.isDeclaration));
     LibraryElement memberLibrary = member.getLibrary();
     // If the method is intercepted, the stub gets the
@@ -279,7 +549,7 @@ class ContainerBuilder extends CodeEmitterHelper {
             parameters,
             js.return_(buildGetter()[closureCallName](arguments)));
 
-        addProperty(invocationName, function);
+        defineStub(invocationName, function);
       }
     }
   }
@@ -296,6 +566,10 @@ class ContainerBuilder extends CodeEmitterHelper {
       if (selectors != null && !selectors.isEmpty) {
         emitCallStubForGetter(member, selectors, builder.addProperty);
       }
+    } else if (member.isFunction()) {
+      if (compiler.codegenWorld.hasInvokedGetter(member, compiler)) {
+        emitDynamicFunctionGetter(member, builder.addProperty);
+      }
     }
   }
 
@@ -321,182 +595,30 @@ class ContainerBuilder extends CodeEmitterHelper {
     jsAst.Expression code = backend.generatedCode[member];
     if (code == null) return;
     String name = namer.getNameOfMember(member);
-    task.interceptorEmitter.recordMangledNameOfMemberMethod(member, name);
-    FunctionSignature parameters = member.computeSignature(compiler);
-    bool needsStubs = !parameters.optionalParameters.isEmpty;
-    bool canTearOff = false;
-    bool isClosure = false;
-    String tearOffName;
-    if (!member.isFunction() || member.isConstructor() || member.isAccessor()) {
-      canTearOff = false;
-    } else if (member.isInstanceMember()) {
-      if (member.getEnclosingClass().isClosure()) {
-        canTearOff = false;
-        isClosure = true;
-      } else {
-        // Careful with operators.
-        canTearOff = compiler.codegenWorld.hasInvokedGetter(member, compiler);
-        tearOffName = namer.getterName(member);
-      }
-    } else {
-      canTearOff =
-          compiler.codegenWorld.staticFunctionsNeedingGetter.contains(member);
-      tearOffName = namer.getStaticClosureName(member);
+    if (backend.isInterceptedMethod(member)) {
+      task.interceptorEmitter.interceptorInvocationNames.add(name);
     }
-
-    bool canBeReflected = backend.isAccessibleByReflection(member);
-    bool needStructuredInfo =
-        canTearOff || canBeReflected || compiler.enabledFunctionApply;
-    if (!needStructuredInfo) {
-      builder.addProperty(name, code);
-      if (needsStubs) {
-        addParameterStubs(
-            member,
-            (Selector selector, jsAst.Fun function) {
-              builder.addProperty(namer.invocationName(selector), function);
-            });
+    code = task.metadataEmitter.extendWithMetadata(member, code);
+    builder.addProperty(name, code);
+    String reflectionName = task.getReflectionName(member, name);
+    if (reflectionName != null) {
+      var reflectable =
+          js(backend.isAccessibleByReflection(member) ? '1' : '0');
+      builder.addProperty('+$reflectionName', reflectable);
+      jsAst.Node defaultValues =
+          task.metadataEmitter.reifyDefaultArguments(member);
+      if (defaultValues != null) {
+        String unmangledName = member.name;
+        builder.addProperty('*$unmangledName', defaultValues);
       }
-      return;
     }
-
-    if (canTearOff) {
-      assert(invariant(member, !member.isGenerativeConstructor()));
-      assert(invariant(member, !member.isGenerativeConstructorBody()));
-      assert(invariant(member, !member.isConstructor()));
-    }
-
-    // This element is needed for reflection or needs additional stubs. So we
-    // need to retain additional information.
-
-    // The information is stored in an array with this format:
-    //
-    // 1.   The JS function for this member.
-    // 2.   First stub.
-    // 3.   Name of first stub.
-    // ...
-    // M.   Call name of this member.
-    // M+1. Call name of first stub.
-    // ...
-    // N.   Getter name for tearOff.
-    // N+1. (Required parameter count << 1) + (member.isAccessor() ? 1 : 0).
-    // N+2. (Optional parameter count << 1) +
-    //                      (parameters.optionalParametersAreNamed ? 1 : 0).
-    // N+3. Index to function type in constant pool.
-    // N+4. First default argument.
-    // ...
-    // O.   First parameter name (if needed for reflection or Function.apply).
-    // ...
-    // P.   Unmangled name (if reflectable).
-    // P+1. First metadata (if reflectable).
-    // ...
-
-    List expressions = [];
-
-    String callSelectorString = 'null';
-    if (member.isFunction()) {
-      Selector callSelector =
-          new Selector.fromElement(member, compiler).toCallSelector();
-      callSelectorString = '"${namer.invocationName(callSelector)}"';
-    }
-
-    // On [requiredParameterCount], the lower bit is set if this method can be
-    // called reflectively.
-    int requiredParameterCount = parameters.requiredParameterCount << 1;
-    if (member.isAccessor()) requiredParameterCount++;
-
-    int optionalParameterCount = parameters.optionalParameterCount << 1;
-    if (parameters.optionalParametersAreNamed) optionalParameterCount++;
-
-    expressions.add(code);
-
-    // TODO(ahe): Remove comments from output.
-    List tearOffInfo =
-        [new jsAst.LiteralString('$callSelectorString /* tearOffInfo */')];
-
-    if (needsStubs || canTearOff) {
-      addParameterStubs(member, (Selector selector, jsAst.Fun function) {
-        expressions.add(function);
-        if (member.isInstanceMember()) {
-          Set invokedSelectors =
-              compiler.codegenWorld.invokedNames[member.name];
-          if (invokedSelectors != null && invokedSelectors.contains(selector)) {
-            expressions.add(js.string(namer.invocationName(selector)));
-          } else {
-            // Don't add a stub for calling this as a regular instance method,
-            // we only need the "call" stub for implicit closures of this
-            // method.
-            expressions.add("null");
-          }
-        } else {
-          // Static methods don't need "named" stubs as the default arguments
-          // are inlined at call sites. But static methods might need "call"
-          // stubs for implicit closures.
-          expressions.add("null");
-          // TOOD(ahe): Since we know when reading static data versus instance
-          // data, we can eliminate this element.
-        }
-        Set<Selector> callSelectors = compiler.codegenWorld.invokedNames[
-            namer.closureInvocationSelectorName];
-        Selector callSelector = selector.toCallSelector();
-        String callSelectorString = 'null';
-        if (canTearOff && callSelectors != null &&
-            callSelectors.contains(callSelector)) {
-          callSelectorString = '"${namer.invocationName(callSelector)}"';
-        }
-        tearOffInfo.add(
-            new jsAst.LiteralString('$callSelectorString /* tearOffInfo */'));
-      }, canTearOff);
-    }
-
-    jsAst.Expression memberTypeExpression;
-    if ((canTearOff || canBeReflected) &&
-        !member.isGenerativeConstructorBody()) {
-      DartType memberType = member.computeType(compiler);
-      if (memberType.containsTypeVariables) {
-        jsAst.Expression thisAccess = js(r'this.$receiver');
-        memberTypeExpression =
-            backend.rti.getSignatureEncoding(memberType, thisAccess);
-      } else {
-        memberTypeExpression =
-            js.toExpression(task.metadataEmitter.reifyType(memberType));
+    if (member.isInstanceMember()) {
+      // TODO(ahe): Where is this done for static/top-level methods?
+      FunctionSignature parameters = member.computeSignature(compiler);
+      if (!parameters.optionalParameters.isEmpty) {
+        addParameterStubs(member, builder.addProperty);
       }
-    } else {
-      memberTypeExpression = js('null');
     }
-
-    expressions
-        ..addAll(tearOffInfo)
-        ..add((tearOffName == null || member.isAccessor())
-              ? js("null") : js.string(tearOffName))
-        ..add(requiredParameterCount)
-        ..add(optionalParameterCount)
-        ..add(memberTypeExpression)
-        ..addAll(task.metadataEmitter.reifyDefaultArguments(member));
-
-    if (canBeReflected || compiler.enabledFunctionApply) {
-      parameters.orderedForEachParameter((Element parameter) {
-        expressions.add(task.metadataEmitter.reifyName(parameter.name));
-      });
-    }
-    if (canBeReflected) {
-      jsAst.LiteralString reflectionName;
-      if (member.isConstructor()) {
-        String reflectionNameString = task.getReflectionName(member, name);
-        reflectionName =
-            new jsAst.LiteralString(
-                '"new ${Elements.reconstructConstructorName(member)}"'
-                ' /* $reflectionNameString */');
-      } else {
-        reflectionName = js.string(member.name);
-      }
-      expressions
-          ..add(reflectionName)
-          ..addAll(task.metadataEmitter.computeMetadata(member));
-    } else if (isClosure && compiler.enabledFunctionApply) {
-      expressions.add(js.string(member.name));
-    }
-
-    builder.addProperty(name, js.toExpression(expressions));
   }
 
   void addMemberField(VariableElement member, ClassBuilder builder) {