MIPS: [runtime] Throw exception for derived constructors in correct context.

src/mips64/builtins-mips64.cc

Index: src/mips64/builtins-mips64.cc
diff --git a/src/mips64/builtins-mips64.cc b/src/mips64/builtins-mips64.cc
index a0bc3d3226ca1f79cb56d5d1ea17cc8a5ddcb9b2..0310173c0360a521ec72c0eeb46255d8d7edeb22 100644
--- a/src/mips64/builtins-mips64.cc
+++ b/src/mips64/builtins-mips64.cc
@@ -422,7 +422,8 @@ void Builtins::Generate_InOptimizationQueue(MacroAssembler* masm) {
 
 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                            bool is_api_function,
-                                           bool create_implicit_receiver) {
+                                           bool create_implicit_receiver,
+                                           bool check_derived_construct) {
   // ----------- S t a t e -------------
   //  -- a0     : number of arguments
   //  -- a1     : constructor function
@@ -677,6 +678,20 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
     // Leave construct frame.
   }
 
+  // ES6 9.2.2. Step 13+
+  // Check that the result is not a Smi, indicating that the constructor result
+  // from a derived class is neither undefined nor an Object.
+  if (check_derived_construct) {
+    Label dont_throw;
+    __ JumpIfNotSmi(v0, &dont_throw);
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ push(v0);

[Camillo Bruni, 2016/01/15 13:51:47]

same here ;)

[balazs.kilvady, 2016/01/15 13:59:44]

Done.

+      __ CallRuntime(Runtime::kThrowDerivedConstructorReturnedNonObject);
+    }
+    __ bind(&dont_throw);
+  }
+
   __ SmiScale(a4, a1, kPointerSizeLog2);
   __ Daddu(sp, sp, a4);
   __ Daddu(sp, sp, kPointerSize);
@@ -688,23 +703,23 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
 
 
 void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, false, true);
+  Generate_JSConstructStubHelper(masm, false, true, false);
 }
 
 
 void Builtins::Generate_JSConstructStubApi(MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, true, true);
+  Generate_JSConstructStubHelper(masm, true, true, false);
 }
 
 
 void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, false, false);
+  Generate_JSConstructStubHelper(masm, false, false, false);
 }
 
 
 void Builtins::Generate_JSBuiltinsConstructStubForDerived(
     MacroAssembler* masm) {
-  Generate_JSConstructStubHelper(masm, false, false);
+  Generate_JSConstructStubHelper(masm, false, false, true);
 }