[strong] Strong classes can't extend null

BUG=v8:3956
LOG=N

Review URL: https://codereview.chromium.org/1235883002

Cr-Commit-Position: refs/heads/master@{#29606}

src/compiler/ast-graph-builder.cc

@@ -1562,7 +1562,10 @@ void AstGraphBuilder::VisitClassLiteralContents(ClassLiteral* expr) {
   Node* script = jsgraph()->Constant(info()->script());
   Node* start = jsgraph()->Constant(expr->start_position());
   Node* end = jsgraph()->Constant(expr->end_position());
-  const Operator* opc = javascript()->CallRuntime(Runtime::kDefineClass, 6);
+  const Operator* opc = javascript()->CallRuntime(
+      is_strong(language_mode()) ? Runtime::kDefineClassStrong
+                                 : Runtime::kDefineClass,
+      6);
   Node* literal = NewNode(opc, name, extends, constructor, script, start, end);
   PrepareFrameState(literal, expr->CreateLiteralId(),
                     OutputFrameStateCombine::Push());

src/full-codegen.cc

@@ -1184,7 +1184,9 @@ void FullCodeGenerator::VisitClassLiteral(ClassLiteral* lit) {
     __ Push(Smi::FromInt(lit->start_position()));
     __ Push(Smi::FromInt(lit->end_position()));
 
-    __ CallRuntime(Runtime::kDefineClass, 6);
+    __ CallRuntime(is_strong(language_mode()) ? Runtime::kDefineClassStrong
+                                              : Runtime::kDefineClass,
+                   6);
     PrepareForBailoutForId(lit->CreateLiteralId(), TOS_REG);
 
     int store_slot_index = 0;

src/messages.h

@@ -230,6 +230,7 @@ class CallSite {
     "In strong mode, calling a function with too few arguments is deprecated") \
   T(StrongDeleteProperty,                                                      \
     "Deleting property '%' of strong object '%' is deprecated")                \
+  T(StrongExtendNull, "In strong mode, classes extending null are deprecated") \
   T(StrongImplicitConversion,                                                  \
     "In strong mode, implicit conversions are deprecated")                     \
   T(StrongRedefineDisallowed,                                                  \

src/runtime/runtime-classes.cc

@@ -93,16 +93,11 @@ RUNTIME_FUNCTION(Runtime_HomeObjectSymbol) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_DefineClass) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 6);
-  CONVERT_ARG_HANDLE_CHECKED(Object, name, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, super_class, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, 2);
-  CONVERT_ARG_HANDLE_CHECKED(Script, script, 3);
-  CONVERT_SMI_ARG_CHECKED(start_position, 4);
-  CONVERT_SMI_ARG_CHECKED(end_position, 5);
-
+static MaybeHandle<Object> DefineClass(Isolate* isolate, Handle<Object> name,
+                                       Handle<Object> super_class,
+                                       Handle<JSFunction> constructor,
+                                       Handle<Script> script,
+                                       int start_position, int end_position) {
   Handle<Object> prototype_parent;
   Handle<Object> constructor_parent;
 
@@ -113,26 +108,30 @@ RUNTIME_FUNCTION(Runtime_DefineClass) {
       prototype_parent = isolate->factory()->null_value();
     } else if (super_class->IsSpecFunction()) {
       if (Handle<JSFunction>::cast(super_class)->shared()->is_generator()) {
-        THROW_NEW_ERROR_RETURN_FAILURE(
+        THROW_NEW_ERROR(
             isolate,
-            NewTypeError(MessageTemplate::kExtendsValueGenerator, super_class));
+            NewTypeError(MessageTemplate::kExtendsValueGenerator, super_class),
+            Object);
       }
-      ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      ASSIGN_RETURN_ON_EXCEPTION(
           isolate, prototype_parent,
           Runtime::GetObjectProperty(isolate, super_class,
                                      isolate->factory()->prototype_string(),
-                                     SLOPPY));
+                                     SLOPPY),
+          Object);
       if (!prototype_parent->IsNull() && !prototype_parent->IsSpecObject()) {
-        THROW_NEW_ERROR_RETURN_FAILURE(
+        THROW_NEW_ERROR(
             isolate, NewTypeError(MessageTemplate::kPrototypeParentNotAnObject,
-                                  prototype_parent));
+                                  prototype_parent),
+            Object);
       }
       constructor_parent = super_class;
     } else {
       // TODO(arv): Should be IsConstructor.
-      THROW_NEW_ERROR_RETURN_FAILURE(
+      THROW_NEW_ERROR(
           isolate,
-          NewTypeError(MessageTemplate::kExtendsValueNotFunction, super_class));
+          NewTypeError(MessageTemplate::kExtendsValueNotFunction, super_class),
+          Object);
     }
   }
 
@@ -155,42 +154,88 @@ RUNTIME_FUNCTION(Runtime_DefineClass) {
   JSFunction::SetPrototype(constructor, prototype);
   PropertyAttributes attribs =
       static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE | READ_ONLY);
-  RETURN_FAILURE_ON_EXCEPTION(
-      isolate, JSObject::SetOwnPropertyIgnoreAttributes(
-                   constructor, isolate->factory()->prototype_string(),
-                   prototype, attribs));
+  RETURN_ON_EXCEPTION(isolate,
+                      JSObject::SetOwnPropertyIgnoreAttributes(
+                          constructor, isolate->factory()->prototype_string(),
+                          prototype, attribs),
+                      Object);
 
   // TODO(arv): Only do this conditionally.
   Handle<Symbol> home_object_symbol(isolate->heap()->home_object_symbol());
-  RETURN_FAILURE_ON_EXCEPTION(
+  RETURN_ON_EXCEPTION(
       isolate, JSObject::SetOwnPropertyIgnoreAttributes(
-                   constructor, home_object_symbol, prototype, DONT_ENUM));
+                   constructor, home_object_symbol, prototype, DONT_ENUM),
+      Object);
 
   if (!constructor_parent.is_null()) {
-    RETURN_FAILURE_ON_EXCEPTION(
-        isolate,
-        JSObject::SetPrototype(constructor, constructor_parent, false));
+    RETURN_ON_EXCEPTION(
+        isolate, JSObject::SetPrototype(constructor, constructor_parent, false),
+        Object);
   }
 
   JSObject::AddProperty(prototype, isolate->factory()->constructor_string(),
                         constructor, DONT_ENUM);
 
   // Install private properties that are used to construct the FunctionToString.
-  RETURN_FAILURE_ON_EXCEPTION(
+  RETURN_ON_EXCEPTION(
       isolate, Object::SetProperty(constructor,
                                    isolate->factory()->class_script_symbol(),
-                                   script, STRICT));
-  RETURN_FAILURE_ON_EXCEPTION(
+                                   script, STRICT),
+      Object);
+  RETURN_ON_EXCEPTION(
       isolate,
       Object::SetProperty(
           constructor, isolate->factory()->class_start_position_symbol(),
-          handle(Smi::FromInt(start_position), isolate), STRICT));
-  RETURN_FAILURE_ON_EXCEPTION(
+          handle(Smi::FromInt(start_position), isolate), STRICT),
+      Object);
+  RETURN_ON_EXCEPTION(
       isolate, Object::SetProperty(
                    constructor, isolate->factory()->class_end_position_symbol(),
-                   handle(Smi::FromInt(end_position), isolate), STRICT));
+                   handle(Smi::FromInt(end_position), isolate), STRICT),
+      Object);
+
+  return constructor;
+}
+
+
+RUNTIME_FUNCTION(Runtime_DefineClass) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 6);
+  CONVERT_ARG_HANDLE_CHECKED(Object, name, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, super_class, 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Script, script, 3);
+  CONVERT_SMI_ARG_CHECKED(start_position, 4);
+  CONVERT_SMI_ARG_CHECKED(end_position, 5);
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, DefineClass(isolate, name, super_class, constructor,
+                                   script, start_position, end_position));
+  return *result;
+}
+
+
+RUNTIME_FUNCTION(Runtime_DefineClassStrong) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 6);
+  CONVERT_ARG_HANDLE_CHECKED(Object, name, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, super_class, 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Script, script, 3);
+  CONVERT_SMI_ARG_CHECKED(start_position, 4);
+  CONVERT_SMI_ARG_CHECKED(end_position, 5);
 
-  return *constructor;
+  if (super_class->IsNull()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewTypeError(MessageTemplate::kStrongExtendNull));
+  }
+
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, DefineClass(isolate, name, super_class, constructor,
+                                   script, start_position, end_position));
+  return *result;
 }
 
 

src/runtime/runtime.h

@@ -76,6 +76,7 @@ namespace internal {
   F(ToMethod, 2, 1)                           \
   F(HomeObjectSymbol, 0, 1)                   \
   F(DefineClass, 6, 1)                        \
+  F(DefineClassStrong, 6, 1)                  \
   F(DefineClassMethod, 3, 1)                  \
   F(ClassGetSourceCode, 1, 1)                 \
   F(LoadFromSuper, 4, 1)                      \

test/mjsunit/strong/class-extend-null.js

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --strong-mode --allow-natives-syntax
+
+(function() {
+"use strict";
+
+let foo = null;
+
+function nullLiteral() {
+  class Class1 extends null {
+    constructor() {
+      super();
+    }
+  }
+}
+
+function nullVariable() {
+  class Class2 extends foo {
+    constructor() {
+      super();
+    }
+  }
+}
+
+function nullLiteralClassExpr() {
+  (class extends null {});
+}
+
+function nullVariableClassExpr() {
+  (class extends foo {});
+}
+
+assertDoesNotThrow(nullLiteral);
+%OptimizeFunctionOnNextCall(nullLiteral);
+assertDoesNotThrow(nullLiteral);
+
+assertDoesNotThrow(nullVariable);
+%OptimizeFunctionOnNextCall(nullVariable);
+assertDoesNotThrow(nullVariable);
+
+assertDoesNotThrow(nullLiteralClassExpr);
+%OptimizeFunctionOnNextCall(nullLiteralClassExpr);
+assertDoesNotThrow(nullLiteralClassExpr);
+
+assertDoesNotThrow(nullVariableClassExpr);
+%OptimizeFunctionOnNextCall(nullVariableClassExpr);
+assertDoesNotThrow(nullVariableClassExpr);
+})();
+
+(function() {
+"use strong";
+
+let foo = null;
+
+function nullLiteral() {
+  class Class1 extends null {
+    constructor() {
+      super();
+    }
+  }
+}
+
+function nullVariable() {
+  class Class2 extends foo {
+    constructor() {
+      super();
+    }
+  }
+}
+
+function nullLiteralClassExpr() {
+  (class extends null {});
+}
+
+function nullVariableClassExpr() {
+  (class extends foo {});
+}
+
+assertThrows(nullLiteral, TypeError);
+%OptimizeFunctionOnNextCall(nullLiteral);
+assertThrows(nullLiteral, TypeError);
+
+assertThrows(nullVariable, TypeError);
+%OptimizeFunctionOnNextCall(nullVariable);
+assertThrows(nullVariable, TypeError);
+
+assertThrows(nullLiteralClassExpr, TypeError);
+%OptimizeFunctionOnNextCall(nullLiteralClassExpr);
+assertThrows(nullLiteralClassExpr, TypeError);
+
+assertThrows(nullVariableClassExpr, TypeError);
+%OptimizeFunctionOnNextCall(nullVariableClassExpr);
+assertThrows(nullVariableClassExpr, TypeError);
+})();