Bug 1083482 part 5 - Clean up CloseIterator, remove UnwindIteratorForException. r=arai

js/src/jit/BaselineIC.cpp

@@ -4274,16 +4274,15 @@ ICIteratorMore_Native::Compiler::generateStubCode(MacroAssembler& masm)
 // IteratorClose_Fallback
 //
 
-static bool
+static void
 DoIteratorCloseFallback(JSContext* cx, ICIteratorClose_Fallback* stub, HandleValue iterValue)
 {
     FallbackICSpew(cx, stub, "IteratorClose");
 
-    RootedObject iteratorObject(cx, &iterValue.toObject());
-    return CloseIterator(cx, iteratorObject);
+    CloseIterator(&iterValue.toObject());
 }
 
-typedef bool (*DoIteratorCloseFallbackFn)(JSContext*, ICIteratorClose_Fallback*, HandleValue);
+typedef void (*DoIteratorCloseFallbackFn)(JSContext*, ICIteratorClose_Fallback*, HandleValue);
 static const VMFunction DoIteratorCloseFallbackInfo =
     FunctionInfo<DoIteratorCloseFallbackFn>(DoIteratorCloseFallback, "DoIteratorCloseFallback",
                                             TailCall);

js/src/jit/CodeGenerator.cpp

@@ -9291,9 +9291,9 @@ CodeGenerator::visitIsNoIterAndBranch(LIsNoIterAndBranch* lir)
         masm.jump(ifFalse);
 }
 
-typedef bool (*CloseIteratorFn)(JSContext*, HandleObject);
-static const VMFunction CloseIteratorInfo =
-    FunctionInfo<CloseIteratorFn>(CloseIterator, "CloseIterator");
+typedef void (*CloseIteratorFromIonFn)(JSContext*, JSObject*);
+static const VMFunction CloseIteratorFromIonInfo =
+    FunctionInfo<CloseIteratorFromIonFn>(CloseIteratorFromIon, "CloseIteratorFromIon");
 
 void
 CodeGenerator::visitIteratorEnd(LIteratorEnd* lir)
@@ -9303,7 +9303,7 @@ CodeGenerator::visitIteratorEnd(LIteratorEnd* lir)
     const Register temp2 = ToRegister(lir->temp2());
     const Register temp3 = ToRegister(lir->temp3());
 
-    OutOfLineCode* ool = oolCallVM(CloseIteratorInfo, lir, ArgList(obj), StoreNothing());
+    OutOfLineCode* ool = oolCallVM(CloseIteratorFromIonInfo, lir, ArgList(obj), StoreNothing());
 
     LoadNativeIterator(masm, obj, temp1, ool->entry());
 

js/src/jit/JitFrames.cpp

@@ -139,7 +139,7 @@ CloseLiveIteratorIon(JSContext* cx, const InlineFrameIterator& frame, JSTryNote*
 
     if (cx->isExceptionPending()) {
         if (tn->kind == JSTRY_FOR_IN)
-            UnwindIteratorForException(cx, iterObject);
+            CloseIterator(iterObject);
         else
             IteratorCloseForException(cx, iterObject);
     } else {
@@ -429,14 +429,8 @@ ProcessTryNotesBaseline(JSContext* cx, const JSJitFrameIter& frame, EnvironmentI
             uint8_t* stackPointer;
             BaselineFrameAndStackPointersFromTryNote(tn, frame, &framePointer, &stackPointer);
             Value iterValue(*reinterpret_cast<Value*>(stackPointer));
-            RootedObject iterObject(cx, &iterValue.toObject());
-            if (!UnwindIteratorForException(cx, iterObject)) {
-                // See comment in the JSTRY_FOR_IN case in Interpreter.cpp's
-                // ProcessTryNotes.
-                SettleOnTryNote(cx, tn, frame, ei, rfe, pc);
-                MOZ_ASSERT(**pc == JSOP_ENDITER);
-                return false;
-            }
+            JSObject* iterObject = &iterValue.toObject();
+            CloseIterator(iterObject);
             break;
           }
 

js/src/jit/VMFunctions.cpp

@@ -1835,6 +1835,12 @@ GetPrototypeOf(JSContext* cx, HandleObject target, MutableHandleValue rval)
     return true;
 }
 
+void
+CloseIteratorFromIon(JSContext* cx, JSObject* obj)
+{
+    CloseIterator(obj);
+}
+
 typedef bool (*SetObjectElementFn)(JSContext*, HandleObject, HandleValue,
                                    HandleValue, HandleValue, bool);
 const VMFunction SetObjectElementInfo =

js/src/jit/VMFunctions.h

@@ -894,6 +894,9 @@ TypeOfObject(JSObject* obj, JSRuntime* rt);
 bool
 GetPrototypeOf(JSContext* cx, HandleObject target, MutableHandleValue rval);
 
+void
+CloseIteratorFromIon(JSContext* cx, JSObject* obj);
+
 extern const VMFunction SetObjectElementInfo;
 
 } // namespace jit

js/src/jsiter.cpp

@@ -1263,8 +1263,8 @@ js::ValueToIterator(JSContext* cx, unsigned flags, HandleValue vp)
     return GetIterator(cx, obj, flags);
 }
 
-bool
-js::CloseIterator(JSContext* cx, HandleObject obj)
+void
+js::CloseIterator(JSObject* obj)
 {
     if (obj->is<PropertyIteratorObject>()) {
         /* Remove enumerators from the active list, which is a stack. */
@@ -1283,22 +1283,6 @@ js::CloseIterator(JSContext* cx, HandleObject obj)
             ni->props_cursor = ni->props_array;
         }
     }
-
-    return true;
-}
-
-bool
-js::UnwindIteratorForException(JSContext* cx, HandleObject obj)
-{
-    RootedValue v(cx);
-    bool getOk = cx->getPendingException(&v);
-    cx->clearPendingException();
-    if (!CloseIterator(cx, obj))
-        return false;
-    if (!getOk)
-        return false;
-    cx->setPendingException(v);
-    return true;
 }
 
 bool

js/src/jsiter.h

@@ -182,11 +182,8 @@ NewEmptyPropertyIterator(JSContext* cx, unsigned flags);
 JSObject*
 ValueToIterator(JSContext* cx, unsigned flags, HandleValue vp);
 
-bool
-CloseIterator(JSContext* cx, HandleObject iterObj);
-
-bool
-UnwindIteratorForException(JSContext* cx, HandleObject obj);
+void
+CloseIterator(JSObject* obj);
 
 bool
 IteratorCloseForException(JSContext* cx, HandleObject obj);

js/src/proxy/CrossCompartmentWrapper.cpp

@@ -266,17 +266,16 @@ CanReify(HandleObject obj)
 
 struct AutoCloseIterator
 {
-    AutoCloseIterator(JSContext* cx, PropertyIteratorObject* obj) : cx(cx), obj(cx, obj) {}
+    AutoCloseIterator(JSContext* cx, PropertyIteratorObject* obj) : obj(cx, obj) {}
 
     ~AutoCloseIterator() {
         if (obj)
-            MOZ_ALWAYS_TRUE(CloseIterator(cx, obj));
+            CloseIterator(obj);
     }
 
     void clear() { obj = nullptr; }
 
   private:
-    JSContext* cx;
     Rooted<PropertyIteratorObject*> obj;
 };
 
@@ -314,7 +313,7 @@ Reify(JSContext* cx, JSCompartment* origin, HandleObject objp)
         }
 
         close.clear();
-        MOZ_ALWAYS_TRUE(CloseIterator(cx, iterObj));
+        CloseIterator(iterObj);
 
         obj = EnumeratedIdVectorToIterator(cx, obj, ni->flags, keys);
     }

js/src/vm/Interpreter.cpp

@@ -1270,16 +1270,8 @@ ProcessTryNotes(JSContext* cx, EnvironmentIter& ei, InterpreterRegs& regs)
             DebugOnly<jsbytecode*> pc = regs.fp()->script()->main() + tn->start + tn->length;
             MOZ_ASSERT(JSOp(*pc) == JSOP_ENDITER);
             Value* sp = regs.spForStackDepth(tn->stackDepth);
-            RootedObject obj(cx, &sp[-1].toObject());
-            if (!UnwindIteratorForException(cx, obj)) {
-                // We should only settle on the note only if
-                // UnwindIteratorForException itself threw, as
-                // onExceptionUnwind should be called anew with the new
-                // location of the throw (the iterator). Indeed, we must
-                // settle to avoid infinitely handling the same exception.
-                SettleOnTryNote(cx, tn, ei, regs);
-                return ErrorReturnContinuation;
-            }
+            JSObject* obj = &sp[-1].toObject();
+            CloseIterator(obj);
             break;
           }
 
@@ -2280,11 +2272,8 @@ CASE(JSOP_ENDITER)
 {
     MOZ_ASSERT(REGS.stackDepth() >= 1);
     COUNT_COVERAGE();
-    ReservedRooted<JSObject*> obj(&rootObject0, &REGS.sp[-1].toObject());
-    bool ok = CloseIterator(cx, obj);
+    CloseIterator(&REGS.sp[-1].toObject());
     REGS.sp--;
-    if (!ok)
-        goto error;
 }
 END_CASE(JSOP_ENDITER)