Found some issues

src/core/types.h

@@ -385,6 +385,9 @@ class BoxedString;
 
 class Box {
 public:
+    // Add a no-op constructor to make sure that we don't zero-initialize cls
+    Box() {}
+
     void* operator new(size_t size, BoxedClass* cls) __attribute__((visibility("default")));
     void operator delete(void* ptr) __attribute__((visibility("default"))) { abort(); }
 

src/runtime/capi.cpp

@@ -63,17 +63,6 @@ int Py_Py3kWarningFlag;
 
 BoxedClass* capifunc_cls;
 
-extern "C" PyObject* PyType_GenericAlloc(PyTypeObject* cls, Py_ssize_t nitems) noexcept {
-    RELEASE_ASSERT(nitems == 0, "unimplemented");
-    RELEASE_ASSERT(cls->tp_itemsize == 0, "unimplemented");
-
-    auto rtn = (PyObject*)gc_alloc(cls->tp_basicsize, gc::GCKind::PYTHON);
-    memset(rtn, 0, cls->tp_basicsize);
-
-    PyObject_Init(rtn, cls);
-    return rtn;
-}
-
 BoxedClass* wrapperdescr_cls, *wrapperobject_cls;
 
 Box* BoxedWrapperDescriptor::__get__(BoxedWrapperDescriptor* self, Box* inst, Box* owner) {

src/runtime/types.cpp

@@ -57,9 +57,7 @@ bool IN_SHUTDOWN = false;
 #define SLICE_STOP_OFFSET ((char*)&(((BoxedSlice*)0x01)->stop) - (char*)0x1)
 #define SLICE_STEP_OFFSET ((char*)&(((BoxedSlice*)0x01)->step) - (char*)0x1)
 
-PyObject* PyType_GenericAlloc(BoxedClass* cls, Py_ssize_t nitems) noexcept {
-    abort(); // untested
-
+extern "C" PyObject* PyType_GenericAlloc(BoxedClass* cls, Py_ssize_t nitems) noexcept {
     assert(cls);
     RELEASE_ASSERT(nitems == 0, "");
     RELEASE_ASSERT(cls->tp_itemsize == 0, "");
@@ -75,6 +73,7 @@ PyObject* PyType_GenericAlloc(BoxedClass* cls, Py_ssize_t nitems) noexcept {
     Box* rtn = static_cast<Box*>(mem);
 
     PyObject_Init(rtn, cls);
+    assert(rtn->cls);
 
     return rtn;
 }
@@ -898,6 +897,7 @@ void setupRuntime() {
 
     none_cls = new BoxedHeapClass(object_cls, NULL, 0, sizeof(Box), false);
     None = new (none_cls) Box();
+    assert(None->cls);
     gc::registerPermanentRoot(None);
 
     // You can't actually have an instance of basestring