Add new PyCode_HasFreeVars implementation

In Pyston the PyCodeObject just an opaque pointer. Which can't calculate
the number of freevars. Implement a function to check whether there has
freevars in BoxedCode object.

from_cpython/Include/code.h

@@ -74,7 +74,10 @@ PyAPI_DATA(PyTypeObject*) code_cls;
 #define PyCode_Type (*code_cls)
 
 #define PyCode_Check(op) (Py_TYPE(op) == &PyCode_Type)
-#define PyCode_GetNumFree(op) (PyTuple_GET_SIZE((op)->co_freevars))
+// Pyston change: disable this macro.
+// In Pyston the PyCodeObject is just an opaque pointer, get its size
+// directly will cause error.
+// #define PyCode_GetNumFree(op) (PyTuple_GET_SIZE((op)->co_freevars))
 
 /* Public interface */
 PyAPI_FUNC(PyCodeObject *) PyCode_New(
@@ -95,6 +98,7 @@ PyAPI_FUNC(int) PyCode_Addr2Line(PyCodeObject *, int) PYSTON_NOEXCEPT;
 PyAPI_FUNC(int) PyCode_GetArgCount(PyCodeObject *) PYSTON_NOEXCEPT;
 PyAPI_FUNC(BORROWED(PyObject*)) PyCode_GetFilename(PyCodeObject *) PYSTON_NOEXCEPT;
 PyAPI_FUNC(BORROWED(PyObject*)) PyCode_GetName(PyCodeObject *) PYSTON_NOEXCEPT;
+PyAPI_FUNC(int) PyCode_HasFreeVars(PyCodeObject* ) PYSTON_NOEXCEPT;
 
 /* for internal use only */
 #define _PyCode_GETCODEPTR(co, pp) \

src/runtime/code.cpp

@@ -200,11 +200,17 @@ extern "C" BORROWED(PyObject*) PyCode_GetFilename(PyCodeObject* op) noexcept {
     RELEASE_ASSERT(PyCode_Check((Box*)op), "");
     return BoxedCode::filename((Box*)op, NULL);
 }
+
 extern "C" BORROWED(PyObject*) PyCode_GetName(PyCodeObject* op) noexcept {
     RELEASE_ASSERT(PyCode_Check((Box*)op), "");
     return BoxedCode::name((Box*)op, NULL);
 }
 
+extern "C" int PyCode_HasFreeVars(PyCodeObject* _code) noexcept {
+    BoxedCode* code = (BoxedCode*)_code;
+    return code->f->source->getScopeInfo()->takesClosure() ? 1 : 0;
+}
+
 void setupCode() {
     code_cls
         = BoxedClass::create(type_cls, object_cls, 0, 0, sizeof(BoxedCode), false, "code", false,

src/runtime/frame.cpp

@@ -347,6 +347,7 @@ extern "C" PyFrameObject* PyFrame_New(PyThreadState* tstate, PyCodeObject* code,
 extern "C" BORROWED(PyObject*) PyFrame_GetGlobals(PyFrameObject* f) noexcept {
     return BoxedFrame::globals((Box*)f, NULL);
 }
+
 extern "C" BORROWED(PyObject*) PyFrame_GetCode(PyFrameObject* f) noexcept {
     return BoxedFrame::code((Box*)f, NULL);
 }