new classes: implement new.target passing to superclass constructor.

src/arm/full-codegen-arm.cc

Index: src/arm/full-codegen-arm.cc
diff --git a/src/arm/full-codegen-arm.cc b/src/arm/full-codegen-arm.cc
index a4a17efeec1194ac9acfc4e1fead128612b7962e..2ca8bd0af950e245b914beb5f6116c83b80cdea5 100644
--- a/src/arm/full-codegen-arm.cc
+++ b/src/arm/full-codegen-arm.cc
@@ -262,6 +262,10 @@ void FullCodeGenerator::Generate() {
     //   function, receiver address, parameter count.
     // The stub will rewrite receiever and parameter count if the previous
     // stack frame was an arguments adapter frame.
+    ArgumentsAccessStub::HasNewTarget has_new_target =
+        IsSubclassConstructor(info->function()->kind())

[arv (Not doing code reviews), 2015/02/10 20:15:18]

Do we do the right thing in the following case?

class C {
  constructor() {
    assertEquals(C, new.target);
  }
}
new C();

The function above is not a subclass constructor.

Maybe this is just a TODO?


Maybe add a function to SHF called, HasNewTarget()?

[Dmitry Lomov (no reviews), 2015/02/11 00:58:29]

Yes, we do not support new.target in general yet, just passing new.target
through subclass constructor.
I will add that when we support new.target proper

+            ? ArgumentsAccessStub::HAS_NEW_TARGET
+            : ArgumentsAccessStub::NO_NEW_TARGET;
     ArgumentsAccessStub::Type type;
     if (is_strict(language_mode())) {
       type = ArgumentsAccessStub::NEW_STRICT;
@@ -270,7 +274,7 @@ void FullCodeGenerator::Generate() {
     } else {
       type = ArgumentsAccessStub::NEW_SLOPPY_FAST;
     }
-    ArgumentsAccessStub stub(isolate(), type);
+    ArgumentsAccessStub stub(isolate(), type, has_new_target);
     __ CallStub(&stub);
 
     SetVar(arguments, r0, r1, r2);
@@ -450,7 +454,12 @@ void FullCodeGenerator::EmitReturnSequence() {
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
     { Assembler::BlockConstPoolScope block_const_pool(masm_);
-      int32_t sp_delta = (info_->scope()->num_parameters() + 1) * kPointerSize;
+      int32_t arg_count = info_->scope()->num_parameters() + 1;
+      if (FLAG_experimental_classes &&
+          IsSubclassConstructor(info_->function()->kind())) {
+        arg_count++;
+      }
+      int32_t sp_delta = arg_count * kPointerSize;
       CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
       // TODO(svenpanne) The code below is sometimes 4 words, sometimes 5!
       PredictableCodeSizeScope predictable(masm_, -1);
@@ -3257,6 +3266,11 @@ void FullCodeGenerator::VisitCallNew(CallNew* expr) {
 
 
 void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
+  Comment cmnt(masm_, "[ SuperConstructorCall");
+  Variable* new_target_var = scope()->DeclarationScope()->new_target_var();
+  GetVar(result_register(), new_target_var);
+  __ Push(result_register());
+
   SuperReference* super_ref = expr->expression()->AsSuperReference();
   EmitLoadSuperConstructor(super_ref);
   __ push(result_register());
@@ -3300,10 +3314,11 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
   __ Move(r2, FeedbackVector());
   __ mov(r3, Operand(SmiFromSlot(expr->CallFeedbackSlot())));
 
-  // TODO(dslomov): use a different stub and propagate new.target.
-  CallConstructStub stub(isolate(), RECORD_CONSTRUCTOR_TARGET);
+  CallConstructStub stub(isolate(), SUPER_CALL_RECORD_TARGET);
   __ Call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
 
+  __ Drop(1);
+
   RecordJSReturnSite(expr);
 
   EmitVariableAssignment(this_var, Token::INIT_CONST);