ES7: Detect Tail Position Calls and pass that to the runtime

Doing the tail call in the runtime will come in a follow-up patch

Change-Id: I8224aac0edbdc765ee9b97703948edd52fd33f3e
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 9 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 7b1a38ff06..470629bd1f 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -1061,8 +1061,6 @@ ReturnedValue Runtime::method_loadSuperConstructor(ExecutionEngine *engine, cons
     return c->asReturnedValue();
 }
 
-
-
 #endif // V4_BOOTSTRAP
 
 uint RuntimeHelpers::equalHelper(const Value &x, const Value &y)
@@ -1538,6 +1536,15 @@ ReturnedValue Runtime::method_constructWithSpread(ExecutionEngine *engine, const
     return static_cast<const FunctionObject &>(function).callAsConstructor(arguments.argv, arguments.argc, &newTarget);
 }
 
+ReturnedValue Runtime::method_tailCall(ExecutionEngine *engine, const Value &function, const Value &thisObject, Value *argv, int argc)
+{
+    //### unwinding the stack, etc, is done in a subsequent patch
+    if (!function.isFunctionObject())
+        return engine->throwTypeError();
+
+    return static_cast<const FunctionObject &>(function).call(&thisObject, argv, argc);
+}
+
 void Runtime::method_throwException(ExecutionEngine *engine, const Value &value)
 {
     if (!value.isEmpty())