Implement Function.prototype.toMethod.

R=arv@chromium.org, verwaest@chromium.org
BUG=v8:3330
LOG=N

Review URL: https://codereview.chromium.org/475423003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23274 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUILD.gn

@@ -242,6 +242,7 @@ action("js2c_experimental") {
     "src/generator.js",
     "src/harmony-string.js",
     "src/harmony-array.js",
+    "src/harmony-classes.js",
   ]
 
   outputs = [

include/v8.h

@@ -5669,7 +5669,7 @@ class Internals {
   static const int kNullValueRootIndex = 7;
   static const int kTrueValueRootIndex = 8;
   static const int kFalseValueRootIndex = 9;
-  static const int kEmptyStringRootIndex = 161;
+  static const int kEmptyStringRootIndex = 162;
 
   // The external allocation limit should be below 256 MB on all architectures
   // to avoid that resource-constrained embedders run low on memory.

src/bootstrapper.cc

@@ -2063,6 +2063,7 @@ bool Genesis::InstallExperimentalNatives() {
     INSTALL_EXPERIMENTAL_NATIVE(i, generators, "generator.js")
     INSTALL_EXPERIMENTAL_NATIVE(i, strings, "harmony-string.js")
     INSTALL_EXPERIMENTAL_NATIVE(i, arrays, "harmony-array.js")
+    INSTALL_EXPERIMENTAL_NATIVE(i, classes, "harmony-classes.js")
   }
 
   InstallExperimentalNativeFunctions();

src/harmony-classes.js

+// Copyright 2014 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.
+//
+// This file relies on the fact that the following declarations have been made
+// in runtime.js:
+// var $Function = global.Function;
+// var $Array = global.Array;
+
+
+(function() {
+  function FunctionToMethod(homeObject) {
+    if (!IS_SPEC_FUNCTION(this)) {
+      throw MakeTypeError('toMethod_non_function',
+                          [%ToString(this), typeof this]);
+
+    }
+
+    if (!IS_SPEC_OBJECT(homeObject)) {
+      throw MakeTypeError('toMethod_non_object',
+                          [%ToString(homeObject)]);
+    }
+
+    return %ToMethod(this, homeObject);
+  }
+
+  %CheckIsBootstrapping();
+
+  InstallFunctions($Function.prototype, DONT_ENUM, $Array(
+      "toMethod", FunctionToMethod
+  ));
+}());

src/heap/heap.cc

@@ -2878,6 +2878,7 @@ void Heap::CreateInitialObjects() {
   set_observed_symbol(*factory->NewPrivateSymbol());
   set_stack_trace_symbol(*factory->NewPrivateSymbol());
   set_uninitialized_symbol(*factory->NewPrivateSymbol());
+  set_home_object_symbol(*factory->NewPrivateOwnSymbol());
 
   Handle<SeededNumberDictionary> slow_element_dictionary =
       SeededNumberDictionary::New(isolate(), 0, TENURED);

src/heap/heap.h

@@ -185,6 +185,7 @@ namespace internal {
   V(Symbol, stack_trace_symbol, StackTraceSymbol)                              \
   V(Symbol, detailed_stack_trace_symbol, DetailedStackTraceSymbol)             \
   V(Symbol, normal_ic_symbol, NormalICSymbol)                                  \
+  V(Symbol, home_object_symbol, HomeObjectSymbol)                              \
   V(FixedArray, materialized_objects, MaterializedObjects)                     \
   V(FixedArray, allocation_sites_scratchpad, AllocationSitesScratchpad)        \
   V(FixedArray, microtask_queue, MicrotaskQueue)

src/messages.js

@@ -44,6 +44,8 @@ var kMessages = {
   no_setter_in_callback:         ["Cannot set property ", "%0", " of ", "%1", " which has only a getter"],
   apply_non_function:            ["Function.prototype.apply was called on ", "%0", ", which is a ", "%1", " and not a function"],
   apply_wrong_args:              ["Function.prototype.apply: Arguments list has wrong type"],
+  toMethod_non_function:         ["Function.prototype.toMethod was called on ", "%0", ", which is a ", "%1", " and not a function"],
+  toMethod_non_object:           ["Function.prototype.toMethod: home object ", "%0", " is not an object"],
   invalid_in_operator_use:       ["Cannot use 'in' operator to search for '", "%0", "' in ", "%1"],
   instanceof_function_expected:  ["Expecting a function in instanceof check, but got ", "%0"],
   instanceof_nonobject_proto:    ["Function has non-object prototype '", "%0", "' in instanceof check"],

src/objects.cc

@@ -9284,6 +9284,30 @@ void JSFunction::MarkInOptimizationQueue() {
 }
 
 
+Handle<JSFunction> JSFunction::CloneClosure(Handle<JSFunction> function) {
+  Isolate* isolate = function->GetIsolate();
+  Handle<Map> map(function->map());
+  Handle<SharedFunctionInfo> shared(function->shared());
+  Handle<Context> context(function->context());
+  Handle<JSFunction> clone =
+      isolate->factory()->NewFunctionFromSharedFunctionInfo(shared, context);
+
+  if (shared->bound()) {
+    clone->set_function_bindings(function->function_bindings());
+  }
+
+  // In typical case, __proto__ of ``function`` is the default Function
+  // prototype, which means that SetPrototype below is a no-op.
+  // In rare cases when that is not true, we mutate the clone's __proto__.
+  Handle<Object> original_prototype(map->prototype(), isolate);
+  if (*original_prototype != clone->map()->prototype()) {
+    JSObject::SetPrototype(clone, original_prototype, false).Assert();
+  }
+
+  return clone;
+}
+
+
 void SharedFunctionInfo::AddToOptimizedCodeMap(
     Handle<SharedFunctionInfo> shared,
     Handle<Context> native_context,

src/objects.h

@@ -7711,6 +7711,11 @@ class JSFunction: public JSObject {
   static void SetInstancePrototype(Handle<JSFunction> function,
                                    Handle<Object> value);
 
+  // Creates a new closure for the fucntion with the same bindings,
+  // bound values, and prototype. An equivalent of spec operations
+  // ``CloneMethod`` and ``CloneBoundFunction``.
+  static Handle<JSFunction> CloneClosure(Handle<JSFunction> function);
+
   // After prototype is removed, it will not be created when accessed, and
   // [[Construct]] from this function will not be allowed.
   bool RemovePrototype();

src/runtime.cc

@@ -2051,6 +2051,25 @@ RUNTIME_FUNCTION(Runtime_PreventExtensions) {
 }
 
 
+RUNTIME_FUNCTION(Runtime_ToMethod) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, fun, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, home_object, 1);
+  Handle<JSFunction> clone = JSFunction::CloneClosure(fun);
+  Handle<Symbol> home_object_symbol(isolate->heap()->home_object_symbol());
+  JSObject::SetOwnPropertyIgnoreAttributes(clone, home_object_symbol,
+                                           home_object, DONT_ENUM).Assert();
+  return *clone;
+}
+
+
+RUNTIME_FUNCTION(Runtime_HomeObjectSymbol) {
+  DCHECK(args.length() == 0);
+  return isolate->heap()->home_object_symbol();
+}
+
+
 RUNTIME_FUNCTION(Runtime_IsExtensible) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);

test/mjsunit/harmony/toMethod.js

+// Copyright 2014 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: --harmony-classes --allow-natives-syntax
+
+
+(function TestSingleClass() {
+  function f(x) {
+    var a = [0, 1, 2]
+    return a[x];
+  }
+
+  function ClassD() { }
+
+  assertEquals(1, f(1));
+  var g = f.toMethod(ClassD.prototype);
+  assertEquals(1, g(1));
+  assertEquals(undefined, f[%HomeObjectSymbol()]);
+  assertEquals(ClassD.prototype, g[%HomeObjectSymbol()]);
+}());
+
+
+(function TestClassHierarchy() {
+  function f(x) {
+    return function g(y)  { x++; return x + y; };
+  }
+
+  function Base() {}
+  function Derived() { }
+  Derived.prototype = Object.create(Base.prototype);
+
+  var q = f(0);
+  assertEquals(2, q(1));
+  assertEquals(3, q(1));
+  var g = q.toMethod(Derived.prototype);
+  assertFalse(g === q);
+  assertEquals(4, g(1));
+  assertEquals(5, q(1));
+}());
+
+
+(function TestErrorCases() {
+  var sFun = Function.prototype.toMethod;
+  assertThrows(function() { sFun.call({}); }, TypeError);
+  assertThrows(function() { sFun.call({}, {}); }, TypeError);
+  function f(){};
+  assertThrows(function() { f.toMethod(1); }, TypeError);
+}());
+
+
+(function TestPrototypeChain() {
+  var o = {};
+  var o1 = {};
+  function f() { }
+
+  function g() { }
+
+  var fMeth = f.toMethod(o);
+  assertEquals(o, fMeth[%HomeObjectSymbol()]);
+  g.__proto__ = fMeth;
+  assertEquals(undefined, g[%HomeObjectSymbol()]);
+  var gMeth = g.toMethod(o1);
+  assertEquals(fMeth, gMeth.__proto__);
+  assertEquals(o, fMeth[%HomeObjectSymbol()]);
+  assertEquals(o1, gMeth[%HomeObjectSymbol()]);
+}());
+
+
+(function TestBoundFunction() {
+  var o = {};
+  var p = {};
+
+
+  function f(x, y, z, w) {
+    assertEquals(o, this);
+    assertEquals(1, x);
+    assertEquals(2, y);
+    assertEquals(3, z);
+    assertEquals(4, w);
+    return x+y+z+w;
+  }
+
+  var fBound = f.bind(o, 1, 2, 3);
+  var fMeth = fBound.toMethod(p);
+  assertEquals(10, fMeth(4));
+  assertEquals(10, fMeth.call(p, 4));
+  var fBound1 = fBound.bind(o, 4);
+  assertEquals(10, fBound1());
+  var fMethBound = fMeth.bind(o, 4);
+  assertEquals(10, fMethBound());
+}());
+
+(function TestOptimized() {
+  function f(o) {
+    return o.x;
+  }
+  var o = {x : 15};
+  assertEquals(15, f(o));
+  assertEquals(15, f(o));
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals(15, f(o));
+  var g = f.toMethod({});
+  var o1 = {y : 1024, x : "abc"};
+  assertEquals("abc", f(o1));
+  assertEquals("abc", g(o1));
+} ());
+
+(function TestExtensibility() {
+  function f() {}
+  Object.preventExtensions(f);
+  assertFalse(Object.isExtensible(f));
+  var m = f.toMethod({});
+  assertTrue(Object.isExtensible(m));
+}());

test/mjsunit/runtime-gen/homeobjectsymbol.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
+// Flags: --allow-natives-syntax --harmony --harmony-proxies
+%HomeObjectSymbol();

test/mjsunit/runtime-gen/tomethod.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
+// Flags: --allow-natives-syntax --harmony --harmony-proxies
+var _fun = function() {};
+var _home_object = new Object();
+%ToMethod(_fun, _home_object);

tools/generate-runtime-tests.py

@@ -47,8 +47,8 @@ EXPAND_MACROS = [
 # that the parser doesn't bit-rot. Change the values as needed when you add,
 # remove or change runtime functions, but make sure we don't lose our ability
 # to parse them!
-EXPECTED_FUNCTION_COUNT = 429
-EXPECTED_FUZZABLE_COUNT = 330
+EXPECTED_FUNCTION_COUNT = 431
+EXPECTED_FUZZABLE_COUNT = 332
 EXPECTED_CCTEST_COUNT = 7
 EXPECTED_UNKNOWN_COUNT = 17
 EXPECTED_BUILTINS_COUNT = 808

tools/gyp/v8.gyp

@@ -1425,6 +1425,7 @@
           '../../src/generator.js',
           '../../src/harmony-string.js',
           '../../src/harmony-array.js',
+          '../../src/harmony-classes.js',
         ],
         'libraries_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries.bin',
         'libraries_experimental_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-experimental.bin',