Make function proxies work as constructors.

R=kmillikin@chromium.org
BUG=v8:1543
TEST=

Review URL: http://codereview.chromium.org/7628021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9310 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/builtins-arm.cc

@@ -619,12 +619,12 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   //  -- sp[...]: constructor arguments
   // -----------------------------------
 
-  Label non_function_call;
+  Label slow, non_function_call;
   // Check that the function is not a smi.
   __ JumpIfSmi(r1, &non_function_call);
   // Check that the function is a JSFunction.
   __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
-  __ b(ne, &non_function_call);
+  __ b(ne, &slow);
 
   // Jump to the function-specific construct stub.
   __ ldr(r2, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
@@ -633,10 +633,19 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
 
   // r0: number of arguments
   // r1: called object
+  // r2: object type
+  Label do_call;
+  __ bind(&slow);
+  __ cmp(r2, Operand(JS_FUNCTION_PROXY_TYPE));
+  __ b(ne, &non_function_call);
+  __ GetBuiltinEntry(r3, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
+  __ jmp(&do_call);
+
   __ bind(&non_function_call);
+  __ GetBuiltinEntry(r3, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
+  __ bind(&do_call);
   // Set expected number of arguments to zero (not changing r0).
   __ mov(r2, Operand(0, RelocInfo::NONE));
-  __ GetBuiltinEntry(r3, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
   __ SetCallKind(r5, CALL_AS_METHOD);
   __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
           RelocInfo::CODE_TARGET);

src/heap.cc

@@ -3634,6 +3634,7 @@ MaybeObject* Heap::ReinitializeJSReceiver(
 
   // Functions require some minimal initialization.
   if (type == JS_FUNCTION_TYPE) {
+    map->set_function_with_prototype(true);
     String* name;
     MaybeObject* maybe_name = LookupAsciiSymbol("<freezing call trap>");
     if (!maybe_name->To<String>(&name)) return maybe_name;

src/ia32/builtins-ia32.cc

@@ -80,12 +80,12 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   //  -- edi: constructor function
   // -----------------------------------
 
-  Label non_function_call;
+  Label slow, non_function_call;
   // Check that function is not a smi.
   __ JumpIfSmi(edi, &non_function_call);
   // Check that function is a JSFunction.
   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
-  __ j(not_equal, &non_function_call);
+  __ j(not_equal, &slow);
 
   // Jump to the function-specific construct stub.
   __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
@@ -95,10 +95,19 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
 
   // edi: called object
   // eax: number of arguments
+  // ecx: object map
+  Label do_call;
+  __ bind(&slow);
+  __ CmpInstanceType(ecx, JS_FUNCTION_PROXY_TYPE);
+  __ j(not_equal, &non_function_call);
+  __ GetBuiltinEntry(edx, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
+  __ jmp(&do_call);
+
   __ bind(&non_function_call);
+  __ GetBuiltinEntry(edx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
+  __ bind(&do_call);
   // Set expected number of arguments to zero (not changing eax).
   __ Set(ebx, Immediate(0));
-  __ GetBuiltinEntry(edx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
   Handle<Code> arguments_adaptor =
       masm->isolate()->builtins()->ArgumentsAdaptorTrampoline();
   __ SetCallKind(ecx, CALL_AS_METHOD);

src/proxy.js

@@ -41,14 +41,20 @@ $Proxy.createFunction = function(handler, callTrap, constructTrap) {
     throw MakeTypeError("handler_non_object", ["create"])
   if (!IS_SPEC_FUNCTION(callTrap))
     throw MakeTypeError("trap_function_expected", ["createFunction", "call"])
+  var construct
   if (IS_UNDEFINED(constructTrap)) {
-    constructTrap = callTrap
-  } else if (!IS_SPEC_FUNCTION(constructTrap)) {
+    construct = DerivedConstructTrap(callTrap)
+  } else if (IS_SPEC_FUNCTION(constructTrap)) {
+    construct = function() {
+      // Make sure the trap receives 'undefined' as this.
+      return $Function.prototype.apply.call(constructTrap, void 0, arguments)
+    }
+  } else {
     throw MakeTypeError("trap_function_expected",
                         ["createFunction", "construct"])
   }
   return %CreateJSFunctionProxy(
-    handler, callTrap, constructTrap, $Function.prototype)
+    handler, callTrap, construct, $Function.prototype)
 }
 
 
@@ -57,6 +63,17 @@ $Proxy.createFunction = function(handler, callTrap, constructTrap) {
 // Builtins
 ////////////////////////////////////////////////////////////////////////////////
 
+function DerivedConstructTrap(callTrap) {
+  return function() {
+    var proto = this.prototype
+    if (!IS_SPEC_OBJECT(proto)) proto = $Object.prototype
+    var obj = new $Object()
+    obj.__proto__ = proto
+    var result = $Function.prototype.apply.call(callTrap, obj, arguments)
+    return IS_SPEC_OBJECT(result) ? result : obj
+  }
+}
+
 function DelegateCallAndConstruct(callTrap, constructTrap) {
   return function() {
     return %Apply(%_IsConstructCall() ? constructTrap : callTrap,

src/runtime.js

@@ -429,20 +429,10 @@ function CALL_FUNCTION_PROXY() {
 }
 
 
-function CALL_FUNCTION_PROXY_AS_CONSTRUCTOR(proxy) {
-  var arity = %_ArgumentsLength() - 1;
+function CALL_FUNCTION_PROXY_AS_CONSTRUCTOR() {
+  var proxy = this;
   var trap = %GetConstructTrap(proxy);
-  var receiver = void 0;
-  if (!IS_UNDEFINED(trap)) {
-    trap = %GetCallTrap(proxy);
-    var proto = proxy.prototype;
-    if (!IS_SPEC_OBJECT(proto) && proto !== null) {
-      throw MakeTypeError("proto_object_or_null", [proto]);
-    }
-    receiver = new global.Object();
-    receiver.__proto__ = proto;
-  }
-  return %Apply(trap, this, arguments, 1, arity);
+  return %Apply(trap, this, arguments, 0, %_ArgumentsLength());
 }
 
 

src/v8natives.js

@@ -1049,6 +1049,15 @@ function ProxyFix(obj) {
     var code = DelegateCallAndConstruct(callTrap, constructTrap);
     %Fix(obj);  // becomes a regular function
     %SetCode(obj, code);
+    // TODO(rossberg): What about length and other properties? Not specified.
+    // We just put in some half-reasonable defaults for now.
+    var prototype = new $Object();
+    $Object.defineProperty(prototype, "constructor",
+      {value: obj, writable: true, enumerable: false, configrable: true});
+    $Object.defineProperty(obj, "prototype",
+      {value: prototype, writable: true, enumerable: false, configrable: false})
+    $Object.defineProperty(obj, "length",
+      {value: 0, writable: true, enumerable: false, configrable: false});
   } else {
     %Fix(obj);
   }

src/x64/builtins-x64.cc

@@ -79,12 +79,12 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   //  -- rdi: constructor function
   // -----------------------------------
 
-  Label non_function_call;
+  Label slow, non_function_call;
   // Check that function is not a smi.
   __ JumpIfSmi(rdi, &non_function_call);
   // Check that function is a JSFunction.
   __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
-  __ j(not_equal, &non_function_call);
+  __ j(not_equal, &slow);
 
   // Jump to the function-specific construct stub.
   __ movq(rbx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
@@ -94,10 +94,19 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
 
   // rdi: called object
   // rax: number of arguments
+  // rcx: object map
+  Label do_call;
+  __ bind(&slow);
+  __ CmpInstanceType(rcx, JS_FUNCTION_PROXY_TYPE);
+  __ j(not_equal, &non_function_call);
+  __ GetBuiltinEntry(rdx, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
+  __ jmp(&do_call);
+
   __ bind(&non_function_call);
+  __ GetBuiltinEntry(rdx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
+  __ bind(&do_call);
   // Set expected number of arguments to zero (not changing rax).
   __ Set(rbx, 0);
-  __ GetBuiltinEntry(rdx, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
   __ SetCallKind(rcx, CALL_AS_METHOD);
   __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
           RelocInfo::CODE_TARGET);

test/mjsunit/harmony/proxies.js

@@ -30,8 +30,6 @@
 
 // TODO(rossberg): for-in for proxies not implemented.
 // TODO(rossberg): inheritance from proxies not implemented.
-// TODO(rossberg): function proxies as constructors not implemented.
-
 
 // Helper.
 
@@ -1586,23 +1584,30 @@ TestIsEnumerableThrow(Proxy.create({
 // Calling (call, Function.prototype.call, Function.prototype.apply,
 //          Function.prototype.bind).
 
-var global = this
+var global_object = this
 var receiver
 
+function CreateFrozen(handler, callTrap, constructTrap) {
+  if (handler.fix === undefined) handler.fix = function() { return {} }
+  var f = Proxy.createFunction(handler, callTrap, constructTrap)
+  Object.freeze(f)
+  return f
+}
+
 function TestCall(isStrict, callTrap) {
   assertEquals(42, callTrap(5, 37))
 // TODO(rossberg): unrelated bug: this does not succeed for optimized code.
-// assertEquals(isStrict ? undefined : global, receiver)
+// assertEquals(isStrict ? undefined : global_object, receiver)
 
-  var f = Proxy.createFunction({fix: function() { return {} }}, callTrap)
+  var f = Proxy.createFunction({}, callTrap)
   receiver = 333
   assertEquals(42, f(11, 31))
-  assertEquals(isStrict ? undefined : global, receiver)
+  assertEquals(isStrict ? undefined : global_object, receiver)
   var o = {}
   assertEquals(42, Function.prototype.call.call(f, o, 20, 22))
   assertEquals(o, receiver)
   assertEquals(43, Function.prototype.call.call(f, null, 20, 23))
-  assertEquals(isStrict ? null : global, receiver)
+  assertEquals(isStrict ? null : global_object, receiver)
   assertEquals(44, Function.prototype.call.call(f, 2, 21, 23))
   assertEquals(2, receiver.valueOf())
   receiver = 333
@@ -1616,7 +1621,7 @@ function TestCall(isStrict, callTrap) {
   assertEquals(32, Function.prototype.apply.call(ff, {}, [20]))
   assertEquals(o, receiver)
 
-  Object.freeze(f)
+  var f = CreateFrozen({}, callTrap)
   receiver = 333
   assertEquals(42, f(11, 31))
 // TODO(rossberg): unrelated bug: this does not succeed for optimized code.
@@ -1653,21 +1658,18 @@ TestCall(true, Proxy.createFunction({}, function(x, y) {
   receiver = this; return x + y
 }))
 
-var p = Proxy.createFunction({fix: function() {return {}}}, function(x, y) {
+TestCall(false, CreateFrozen({}, function(x, y) {
   receiver = this; return x + y
-})
-TestCall(false, p)
-Object.freeze(p)
-TestCall(false, p)
+}))
 
 
 function TestCallThrow(callTrap) {
-  var f = Proxy.createFunction({fix: function() {return {}}}, callTrap)
+  var f = Proxy.createFunction({}, callTrap)
   assertThrows(function(){ f(11) }, "myexn")
   assertThrows(function(){ Function.prototype.call.call(f, {}, 2) }, "myexn")
   assertThrows(function(){ Function.prototype.apply.call(f, {}, [1]) }, "myexn")
 
-  Object.freeze(f)
+  var f = CreateFrozen({}, callTrap)
   assertThrows(function(){ f(11) }, "myexn")
   assertThrows(function(){ Function.prototype.call.call(f, {}, 2) }, "myexn")
   assertThrows(function(){ Function.prototype.apply.call(f, {}, [1]) }, "myexn")
@@ -1675,8 +1677,139 @@ function TestCallThrow(callTrap) {
 
 TestCallThrow(function() { throw "myexn" })
 TestCallThrow(Proxy.createFunction({}, function() { throw "myexn" }))
+TestCallThrow(CreateFrozen({}, function() { throw "myexn" }))
 
-var p = Proxy.createFunction(
-  {fix: function() {return {}}}, function() { throw "myexn" })
-Object.freeze(p)
-TestCallThrow(p)
+
+
+// Construction (new).
+
+var prototype = {}
+var receiver
+
+var handlerWithPrototype = {
+  fix: function() { return {prototype: prototype} },
+  get: function(r, n) { assertEquals("prototype", n); return prototype }
+}
+
+var handlerSansPrototype = {
+  fix: function() { return {} },
+  get: function(r, n) { assertEquals("prototype", n); return undefined }
+}
+
+function ReturnUndef(x, y) { "use strict"; receiver = this; this.sum = x + y }
+function ReturnThis(x, y) { "use strict"; receiver = this; this.sum = x + y; return this }
+function ReturnNew(x, y) { "use strict"; receiver = this; return {sum: x + y} }
+function ReturnNewWithProto(x, y) {
+  "use strict";
+  receiver = this;
+  var result = Object.create(prototype)
+  result.sum = x + y
+  return result
+}
+
+function TestConstruct(proto, constructTrap) {
+  TestConstruct2(proto, constructTrap, handlerWithPrototype)
+  TestConstruct2(proto, constructTrap, handlerSansPrototype)
+}
+
+function TestConstruct2(proto, constructTrap, handler) {
+  var f = Proxy.createFunction(handler, function() {}, constructTrap)
+  var o = new f(11, 31)
+  // TODO(rossberg): doesn't hold, due to unrelated bug.
+  // assertEquals(undefined, receiver)
+  assertEquals(42, o.sum)
+  assertSame(proto, Object.getPrototypeOf(o))
+
+  var f = CreateFrozen(handler, function() {}, constructTrap)
+  var o = new f(11, 32)
+  // TODO(rossberg): doesn't hold, due to unrelated bug.
+  // assertEquals(undefined, receiver)
+  assertEquals(43, o.sum)
+  assertSame(proto, Object.getPrototypeOf(o))
+}
+
+TestConstruct(Object.prototype, ReturnNew)
+TestConstruct(prototype, ReturnNewWithProto)
+
+TestConstruct(Object.prototype, Proxy.createFunction({}, ReturnNew))
+TestConstruct(prototype, Proxy.createFunction({}, ReturnNewWithProto))
+
+TestConstruct(Object.prototype, CreateFrozen({}, ReturnNew))
+TestConstruct(prototype, CreateFrozen({}, ReturnNewWithProto))
+
+
+function TestConstructFromCall(proto, returnsThis, callTrap) {
+  TestConstructFromCall2(proto, returnsThis, callTrap, handlerWithPrototype)
+  TestConstructFromCall2(proto, returnsThis, callTrap, handlerSansPrototype)
+}
+
+function TestConstructFromCall2(proto, returnsThis, callTrap, handler) {
+  var f = Proxy.createFunction(handler, callTrap)
+  var o = new f(11, 31)
+  if (returnsThis) assertEquals(o, receiver)
+  assertEquals(42, o.sum)
+  assertSame(proto, Object.getPrototypeOf(o))
+
+  var f = CreateFrozen(handler, callTrap)
+  var o = new f(11, 32)
+  if (returnsThis) assertEquals(o, receiver)
+  assertEquals(43, o.sum)
+  assertSame(proto, Object.getPrototypeOf(o))
+}
+
+TestConstructFromCall(Object.prototype, true, ReturnUndef)
+TestConstructFromCall(Object.prototype, true, ReturnThis)
+TestConstructFromCall(Object.prototype, false, ReturnNew)
+TestConstructFromCall(prototype, false, ReturnNewWithProto)
+
+TestConstructFromCall(Object.prototype, true, Proxy.createFunction({}, ReturnUndef))
+TestConstructFromCall(Object.prototype, true, Proxy.createFunction({}, ReturnThis))
+TestConstructFromCall(Object.prototype, false, Proxy.createFunction({}, ReturnNew))
+TestConstructFromCall(prototype, false, Proxy.createFunction({}, ReturnNewWithProto))
+
+TestConstructFromCall(Object.prototype, true, CreateFrozen({}, ReturnUndef))
+TestConstructFromCall(Object.prototype, true, CreateFrozen({}, ReturnThis))
+TestConstructFromCall(Object.prototype, false, CreateFrozen({}, ReturnNew))
+TestConstructFromCall(prototype, false, CreateFrozen({}, ReturnNewWithProto))
+
+ReturnUndef.prototype = prototype
+ReturnThis.prototype = prototype
+ReturnNew.prototype = prototype
+ReturnNewWithProto.prototype = prototype
+
+TestConstructFromCall(prototype, true, ReturnUndef)
+TestConstructFromCall(prototype, true, ReturnThis)
+TestConstructFromCall(Object.prototype, false, ReturnNew)
+TestConstructFromCall(prototype, false, ReturnNewWithProto)
+
+TestConstructFromCall(Object.prototype, true, Proxy.createFunction({}, ReturnUndef))
+TestConstructFromCall(Object.prototype, true, Proxy.createFunction({}, ReturnThis))
+TestConstructFromCall(Object.prototype, false, Proxy.createFunction({}, ReturnNew))
+TestConstructFromCall(prototype, false, Proxy.createFunction({}, ReturnNewWithProto))
+
+TestConstructFromCall(prototype, true, Proxy.createFunction(handlerWithPrototype, ReturnUndef))
+TestConstructFromCall(prototype, true, Proxy.createFunction(handlerWithPrototype, ReturnThis))
+TestConstructFromCall(Object.prototype, false, Proxy.createFunction(handlerWithPrototype, ReturnNew))
+TestConstructFromCall(prototype, false, Proxy.createFunction(handlerWithPrototype, ReturnNewWithProto))
+
+TestConstructFromCall(prototype, true, CreateFrozen(handlerWithPrototype, ReturnUndef))
+TestConstructFromCall(prototype, true, CreateFrozen(handlerWithPrototype, ReturnThis))
+TestConstructFromCall(Object.prototype, false, CreateFrozen(handlerWithPrototype, ReturnNew))
+TestConstructFromCall(prototype, false, CreateFrozen(handlerWithPrototype, ReturnNewWithProto))
+
+
+function TestConstructThrow(trap) {
+  TestConstructThrow2(Proxy.createFunction({fix: function() {return {}}}, trap))
+  TestConstructThrow2(Proxy.createFunction({fix: function() {return {}}},
+    function() {}, trap))
+}
+
+function TestConstructThrow2(f) {
+  assertThrows(function(){ new f(11) }, "myexn")
+  Object.freeze(f)
+  assertThrows(function(){ new f(11) }, "myexn")
+}
+
+TestConstructThrow(function() { throw "myexn" })
+TestConstructThrow(Proxy.createFunction({}, function() { throw "myexn" }))
+TestConstructThrow(CreateFrozen({}, function() { throw "myexn" }))