[runtime] Fix ES6 9.2.1 [[Call]] when encountering a classConstructor.

src/x64/builtins-x64.cc

Index: src/x64/builtins-x64.cc
diff --git a/src/x64/builtins-x64.cc b/src/x64/builtins-x64.cc
index 2e3adb73c566612247f73c3a1fa62c6ebac6623f..885aa12c5e8269e33f44b3c4be80ee03d5f433bc 100644
--- a/src/x64/builtins-x64.cc
+++ b/src/x64/builtins-x64.cc
@@ -1707,6 +1707,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
 
 // static
 void Builtins::Generate_CallFunction(MacroAssembler* masm) {
+  // ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
   // ----------- S t a t e -------------
   //  -- rax : the number of arguments (not including the receiver)
   //  -- rdi : the function to call (checked to be a JSFunction)
@@ -1715,16 +1716,30 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm) {
   Label convert, convert_global_proxy, convert_to_object, done_convert;
   StackArgumentsAccessor args(rsp, rax);
   __ AssertFunction(rdi);
-  // TODO(bmeurer): Throw a TypeError if function's [[FunctionKind]] internal
-  // slot is "classConstructor".
+  STATIC_ASSERT(SharedFunctionInfo::kNativeByteOffset ==

[Benedikt Meurer, 2015/10/22 11:08:05]

Move the STATIC_ASSERT to the actual use site.

[Camillo Bruni, 2015/11/03 16:05:26]

done

+                SharedFunctionInfo::kStrictModeByteOffset);
+
+  __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
+  {
+    Label non_classConstructor;
+    __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));

[Benedikt Meurer, 2015/10/22 11:08:04]

No need to load the shared function info twice.

[Camillo Bruni, 2015/11/03 16:05:26]

done

+    // Check whether the current function is a classConstructor
+    __ testb(FieldOperand(rdx, SharedFunctionInfo::kIsArrowByteOffset),

[Benedikt Meurer, 2015/10/22 11:08:04]

kIsArrowByteOffset is very confusing.

[Camillo Bruni, 2015/11/03 16:05:26]

done

+             Immediate(FunctionKind::kClassConstructor));
+    __ j(zero, &non_classConstructor);

[Benedikt Meurer, 2015/10/22 11:08:04]

You can use Label::kNear here.

[Camillo Bruni, 2015/11/03 16:05:27]

done

+    // Step: 2, If we call a classConstructor Function throw a TypeError.
+    {
+      FrameScope frame(masm, StackFrame::INTERNAL);
+      __ CallRuntime(Runtime::kThrowConstructorNonCallableError, 0);
+    }
+    __ bind(&non_classConstructor);

[Benedikt Meurer, 2015/10/22 11:08:04]

Nit: non_class_constructor

[Camillo Bruni, 2015/11/03 16:05:26]

done

+  }
+
   // Enter the context of the function; ToObject has to run in the function
   // context, and we also need to take the global proxy from the function
   // context in case of conversion.
-  // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
-  STATIC_ASSERT(SharedFunctionInfo::kNativeByteOffset ==
-                SharedFunctionInfo::kStrictModeByteOffset);
   __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
-  __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
+
   // We need to convert the receiver for non-native sloppy mode functions.
   __ testb(FieldOperand(rdx, SharedFunctionInfo::kNativeByteOffset),
            Immediate((1 << SharedFunctionInfo::kNativeBitWithinByte) |