Make gc visitors (gcHandler) static methods on the type being visited.

This serves two purposes.
1) Improve naming consistency (follow the format TYPENAME::gcHandler)
2) In the source file, the visit function declaration is closer to the
   fields of the objects. If a field is added, hopefully it will be
   easier to remember to update the GC visit function.

src/runtime/dict.cpp

@@ -682,7 +682,24 @@ extern "C" Box* dictInit(BoxedDict* self, BoxedTuple* args, BoxedDict* kwargs) {
     return None;
 }
 
-static void BoxedDictIterator:::gcHandler(GCVisitor* v, Box* b) {
+void BoxedDict::gcHandler(GCVisitor* v, Box* b) {
+    assert(isSubclass(b->cls, dict_cls));
+
+    boxGCHandler(v, b);
+
+    BoxedDict* d = (BoxedDict*)b;
+
+    // This feels like a cludge, but we need to find anything that
+    // the unordered_map might have allocated.
+    // Another way to handle this would be to rt_alloc the unordered_map
+    // as well, though that incurs extra memory dereferences which would
+    // be nice to avoid.
+    void** start = (void**)&d->d;
+    void** end = start + (sizeof(d->d) / 8);
+    v->visitPotentialRange(start, end);
+}
+
+void BoxedDictIterator::gcHandler(GCVisitor* v, Box* b) {
     assert(b->cls == dict_iterator_cls);
     boxGCHandler(v, b);
 
@@ -690,7 +707,7 @@ static void BoxedDictIterator:::gcHandler(GCVisitor* v, Box* b) {
     v->visit(it->d);
 }
 
-static void BoxedDictView::gcHandler(GCVisitor* v, Box* b) {
+void BoxedDictView::gcHandler(GCVisitor* v, Box* b) {
     assert(b->cls == dict_items_cls);
     boxGCHandler(v, b);
 
@@ -723,12 +740,12 @@ void setupDict() {
     dict_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedDictIterator::gcHandler, 0, 0,
                                                sizeof(BoxedDictIterator), false, "dictionary-itemiterator");
 
-    dict_keys_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedDictView::gcHandler, 0, 0, sizeof(BoxedDictView), false,
-                                           "dict_keys");
-    dict_values_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedDictView::gcHandler, 0, 0, sizeof(BoxedDictView),
-                                             false, "dict_values");
-    dict_items_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedDictView::gcHandler, 0, 0, sizeof(BoxedDictView),
-                                            false, "dict_items");
+    dict_keys_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedDictView::gcHandler, 0, 0, sizeof(BoxedDictView),
+                                           false, "dict_keys");
+    dict_values_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedDictView::gcHandler, 0, 0,
+                                             sizeof(BoxedDictView), false, "dict_values");
+    dict_items_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedDictView::gcHandler, 0, 0,
+                                            sizeof(BoxedDictView), false, "dict_items");
 
     dict_cls->giveAttr("__len__", new BoxedFunction(boxRTFunction((void*)dictLen, BOXED_INT, 1)));
     dict_cls->giveAttr("__new__", new BoxedFunction(boxRTFunction((void*)dictNew, UNKNOWN, 1, 0, true, true)));

src/runtime/generator.cpp

@@ -378,7 +378,7 @@ extern "C" BoxedGenerator::BoxedGenerator(BoxedFunctionBase* function, Box* arg1
     context = makeContext(stack_begin, (void (*)(intptr_t))generatorEntry);
 }
 
-extern "C" void generatorGCHandler(GCVisitor* v, Box* b) {
+void BoxedGenerator::gcHandler(GCVisitor* v, Box* b) {
     boxGCHandler(v, b);
 
     BoxedGenerator* g = (BoxedGenerator*)b;
@@ -434,8 +434,8 @@ void generatorDestructor(Box* b) {
 
 void setupGenerator() {
     generator_cls
-        = BoxedHeapClass::create(type_cls, object_cls, &generatorGCHandler, 0, offsetof(BoxedGenerator, weakreflist),
-                                 sizeof(BoxedGenerator), false, "generator");
+        = BoxedHeapClass::create(type_cls, object_cls, &BoxedGenerator::gcHandler, 0,
+                                 offsetof(BoxedGenerator, weakreflist), sizeof(BoxedGenerator), false, "generator");
     generator_cls->tp_dealloc = generatorDestructor;
     generator_cls->has_safe_tp_dealloc = true;
     generator_cls->giveAttr("__iter__",

src/runtime/inline/xrange.cpp

@@ -118,7 +118,7 @@ public:
         return boxInt(xrangeIteratorNextUnboxed(s));
     }
 
-    static void xrangeIteratorGCHandler(GCVisitor* v, Box* b) {
+    static void gcHandler(GCVisitor* v, Box* b) {
         boxGCHandler(v, b);
 
         BoxedXrangeIterator* it = (BoxedXrangeIterator*)b;
@@ -195,8 +195,8 @@ Box* xrangeLen(Box* self) {
 
 void setupXrange() {
     xrange_cls = BoxedHeapClass::create(type_cls, object_cls, NULL, 0, 0, sizeof(BoxedXrange), false, "xrange");
-    xrange_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedXrangeIterator::xrangeIteratorGCHandler, 0,
-                                                 0, sizeof(BoxedXrangeIterator), false, "rangeiterator");
+    xrange_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedXrangeIterator::gcHandler, 0, 0,
+                                                 sizeof(BoxedXrangeIterator), false, "rangeiterator");
 
     xrange_cls->giveAttr(
         "__new__",

src/runtime/iterobject.cpp

@@ -112,7 +112,7 @@ Box* seqiterNext(Box* s) {
     return r;
 }
 
-static void seqiterGCVisit(GCVisitor* v, Box* b) {
+void BoxedSeqIter::gcHandler(GCVisitor* v, Box* b) {
     assert(b->cls == seqiter_cls || b->cls == seqreviter_cls);
     boxGCHandler(v, b);
 
@@ -122,7 +122,7 @@ static void seqiterGCVisit(GCVisitor* v, Box* b) {
         v->visit(si->next);
 }
 
-static void iterwrapperGCVisit(GCVisitor* v, Box* b) {
+void BoxedIterWrapper::gcHandler(GCVisitor* v, Box* b) {
     assert(b->cls == iterwrapper_cls);
     boxGCHandler(v, b);
 
@@ -182,8 +182,8 @@ bool calliter_hasnext(Box* b) {
 
 
 void setupIter() {
-    seqiter_cls
-        = BoxedHeapClass::create(type_cls, object_cls, seqiterGCVisit, 0, 0, sizeof(BoxedSeqIter), false, "iterator");
+    seqiter_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedSeqIter::gcHandler, 0, 0, sizeof(BoxedSeqIter),
+                                         false, "iterator");
 
     seqiter_cls->giveAttr("next", new BoxedFunction(boxRTFunction((void*)seqiterNext, UNKNOWN, 1)));
     seqiter_cls->giveAttr("__hasnext__", new BoxedFunction(boxRTFunction((void*)seqiterHasnext, BOXED_BOOL, 1)));
@@ -192,8 +192,8 @@ void setupIter() {
     seqiter_cls->freeze();
     seqiter_cls->tpp_hasnext = seqiterHasnextUnboxed;
 
-    seqreviter_cls
-        = BoxedHeapClass::create(type_cls, object_cls, seqiterGCVisit, 0, 0, sizeof(BoxedSeqIter), false, "reversed");
+    seqreviter_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedSeqIter::gcHandler, 0, 0, sizeof(BoxedSeqIter),
+                                            false, "reversed");
 
     seqreviter_cls->giveAttr("next", new BoxedFunction(boxRTFunction((void*)seqiterNext, UNKNOWN, 1)));
     seqreviter_cls->giveAttr("__hasnext__", new BoxedFunction(boxRTFunction((void*)seqreviterHasnext, BOXED_BOOL, 1)));
@@ -201,8 +201,8 @@ void setupIter() {
 
     seqreviter_cls->freeze();
 
-    iterwrapper_cls = BoxedHeapClass::create(type_cls, object_cls, iterwrapperGCVisit, 0, 0, sizeof(BoxedIterWrapper),
-                                             false, "iterwrapper");
+    iterwrapper_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedIterWrapper::gcHandler, 0, 0,
+                                             sizeof(BoxedIterWrapper), false, "iterwrapper");
 
     iterwrapper_cls->giveAttr("next", new BoxedFunction(boxRTFunction((void*)iterwrapperNext, UNKNOWN, 1)));
     iterwrapper_cls->giveAttr("__hasnext__",

src/runtime/iterobject.h

@@ -36,6 +36,8 @@ public:
     BoxedSeqIter(Box* b, int64_t start) : b(b), idx(start), next(NULL) {}
 
     DEFAULT_CLASS(seqiter_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 extern BoxedClass* iterwrapper_cls;
@@ -49,6 +51,8 @@ public:
     BoxedIterWrapper(Box* iter) : iter(iter), next(NULL) {}
 
     DEFAULT_CLASS(iterwrapper_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 bool calliter_hasnext(Box* b);

src/runtime/list.cpp

@@ -917,12 +917,6 @@ Box* listRemove(BoxedList* self, Box* elt) {
 BoxedClass* list_iterator_cls = NULL;
 BoxedClass* list_reverse_iterator_cls = NULL;
 
-extern "C" void listIteratorGCHandler(GCVisitor* v, Box* b) {
-    boxGCHandler(v, b);
-    BoxedListIterator* it = (BoxedListIterator*)b;
-    v->visit(it->l);
-}
-
 Box* listNew(BoxedClass* cls, Box* container) {
     assert(isSubclass(cls->cls, type_cls));
     assert(isSubclass(cls, list_cls));
@@ -1097,10 +1091,31 @@ extern "C" int PyList_SetSlice(PyObject* a, Py_ssize_t ilow, Py_ssize_t ihigh, P
     }
 }
 
+void BoxedListIterator::gcHandler(GCVisitor* v, Box* b) {
+    boxGCHandler(v, b);
+    BoxedListIterator* it = (BoxedListIterator*)b;
+    v->visit(it->l);
+}
+
+void BoxedList::gcHandler(GCVisitor* v, Box* b) {
+    assert(isSubclass(b->cls, list_cls));
+
+    boxGCHandler(v, b);
+
+    BoxedList* l = (BoxedList*)b;
+    int size = l->size;
+    int capacity = l->capacity;
+    assert(capacity >= size);
+    if (capacity)
+        v->visit(l->elts);
+    if (size)
+        v->visitRange((void**)&l->elts->elts[0], (void**)&l->elts->elts[size]);
+}
+
 void setupList() {
-    list_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &listIteratorGCHandler, 0, 0,
+    list_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedListIterator::gcHandler, 0, 0,
                                                sizeof(BoxedListIterator), false, "listiterator");
-    list_reverse_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &listIteratorGCHandler, 0, 0,
+    list_reverse_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedListIterator::gcHandler, 0, 0,
                                                        sizeof(BoxedListIterator), false, "listreverseiterator");
 
     list_cls->giveAttr("__len__", new BoxedFunction(boxRTFunction((void*)listLen, BOXED_INT, 1)));

src/runtime/list.h

@@ -29,6 +29,8 @@ public:
     BoxedListIterator(BoxedList* l, int start);
 
     DEFAULT_CLASS(list_iterator_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 Box* listIter(Box* self) noexcept;

src/runtime/set.cpp

@@ -25,6 +25,21 @@ extern "C" Box* createSet() {
     return new BoxedSet();
 }
 
+void BoxedSet::gcHandler(GCVisitor* v, Box* b) {
+    boxGCHandler(v, b);
+
+    BoxedSet* s = (BoxedSet*)b;
+
+    // This feels like a cludge, but we need to find anything that
+    // the unordered_map might have allocated.
+    // Another way to handle this would be to rt_alloc the unordered_map
+    // as well, though that incurs extra memory dereferences which would
+    // be nice to avoid.
+    void** start = (void**)&s->s;
+    void** end = start + (sizeof(s->s) / 8);
+    v->visitPotentialRange(start, end);
+}
+
 namespace set {
 
 class BoxedSetIterator : public Box {
@@ -43,15 +58,15 @@ public:
         ++it;
         return rtn;
     }
-};
 
-extern "C" void setIteratorGCHandler(GCVisitor* v, Box* b) {
-    boxGCHandler(v, b);
+    static void gcHandler(GCVisitor* v, Box* b) {
+        boxGCHandler(v, b);
 
-    BoxedSetIterator* it = (BoxedSetIterator*)b;
+        BoxedSetIterator* it = (BoxedSetIterator*)b;
 
-    v->visit(it->s);
-}
+        v->visit(it->s);
+    }
+};
 
 Box* setiteratorHasnext(BoxedSetIterator* self) {
     RELEASE_ASSERT(self->cls == set_iterator_cls, "");
@@ -509,7 +524,7 @@ extern "C" PyObject* PyFrozenSet_New(PyObject* iterable) noexcept {
 using namespace pyston::set;
 
 void setupSet() {
-    set_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &setIteratorGCHandler, 0, 0,
+    set_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedSetIterator::gcHandler, 0, 0,
                                               sizeof(BoxedSetIterator), false, "setiterator");
     set_iterator_cls->giveAttr(
         "__iter__", new BoxedFunction(boxRTFunction((void*)setiteratorIter, typeFromClass(set_iterator_cls), 1)));

src/runtime/set.h

@@ -38,6 +38,8 @@ public:
     template <typename T> __attribute__((visibility("default"))) BoxedSet(T&& s) : s(std::forward<T>(s)) {}
 
     DEFAULT_CLASS(set_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 }
 

src/runtime/str.cpp

@@ -2311,13 +2311,13 @@ public:
         ++self->it;
         return characters[c & UCHAR_MAX];
     }
-};
 
-extern "C" void strIteratorGCHandler(GCVisitor* v, Box* b) {
-    boxGCHandler(v, b);
-    BoxedStringIterator* it = (BoxedStringIterator*)b;
-    v->visit(it->s);
-}
+    static void gcHandler(GCVisitor* v, Box* b) {
+        boxGCHandler(v, b);
+        BoxedStringIterator* it = (BoxedStringIterator*)b;
+        v->visit(it->s);
+    }
+};
 
 Box* strIter(BoxedString* self) noexcept {
     assert(PyString_Check(self));
@@ -2698,7 +2698,7 @@ static PyMethodDef string_methods[] = {
 void setupStr() {
     str_cls->tp_flags |= Py_TPFLAGS_HAVE_NEWBUFFER;
 
-    str_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &strIteratorGCHandler, 0, 0,
+    str_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedStringIterator::gcHandler, 0, 0,
                                               sizeof(BoxedStringIterator), false, "striterator");
     str_iterator_cls->giveAttr("__hasnext__",
                                new BoxedFunction(boxRTFunction((void*)BoxedStringIterator::hasnext, BOXED_BOOL, 1)));

src/runtime/tuple.cpp

@@ -412,12 +412,6 @@ extern "C" PyObject* PyTuple_New(Py_ssize_t size) noexcept {
 
 
 BoxedClass* tuple_iterator_cls = NULL;
-extern "C" void tupleIteratorGCHandler(GCVisitor* v, Box* b) {
-    boxGCHandler(v, b);
-    BoxedTupleIterator* it = (BoxedTupleIterator*)b;
-    v->visit(it->t);
-}
-
 static int64_t tuple_hash(BoxedTuple* v) noexcept {
     long x, y;
     Py_ssize_t len = Py_SIZE(v);
@@ -564,8 +558,21 @@ static Py_ssize_t tuplelength(PyTupleObject* a) {
     return Py_SIZE(a);
 }
 
+void BoxedTuple::gcHandler(GCVisitor* v, Box* b) {
+    boxGCHandler(v, b);
+
+    BoxedTuple* t = (BoxedTuple*)b;
+    v->visitRange((void* const*)&t->elts[0], (void* const*)&t->elts[t->size()]);
+}
+
+extern "C" void BoxedTupleIterator::gcHandler(GCVisitor* v, Box* b) {
+    boxGCHandler(v, b);
+    BoxedTupleIterator* it = (BoxedTupleIterator*)b;
+    v->visit(it->t);
+}
+
 void setupTuple() {
-    tuple_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &tupleIteratorGCHandler, 0, 0,
+    tuple_iterator_cls = BoxedHeapClass::create(type_cls, object_cls, &BoxedTupleIterator::gcHandler, 0, 0,
                                                 sizeof(BoxedTupleIterator), false, "tuple");
 
     tuple_cls->giveAttr("__new__", new BoxedFunction(boxRTFunction((void*)tupleNew, UNKNOWN, 1, 0, true, true)));

src/runtime/tuple.h

@@ -28,6 +28,8 @@ public:
     BoxedTupleIterator(BoxedTuple* t);
 
     DEFAULT_CLASS(tuple_iterator_cls);
+
+    static void gcHandler(GCVisitor* v, Box* _o);
 };
 
 Box* tupleIter(Box* self) noexcept;

src/runtime/types.h

@@ -298,6 +298,8 @@ public:
     static BoxedHeapClass* create(BoxedClass* metatype, BoxedClass* base, gcvisit_func gc_visit, int attrs_offset,
                                   int weaklist_offset, int instance_size, bool is_user_defined, llvm::StringRef name);
 
+    static void gcHandler(GCVisitor* v, Box* b);
+
 private:
     // These functions are not meant for external callers and will mostly just be called
     // by BoxedHeapClass::create(), but setupRuntime() also needs to do some manual class
@@ -471,6 +473,8 @@ public:
     : in_weakreflist(NULL), obj(obj), func(func), im_class(im_class) {}
 
     DEFAULT_CLASS_SIMPLE(instancemethod_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 class GCdArray {
@@ -505,6 +509,8 @@ public:
     static const int INITIAL_CAPACITY;
 
     DEFAULT_CLASS_SIMPLE(list_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 static_assert(sizeof(BoxedList) <= sizeof(PyListObject), "");
 static_assert(sizeof(BoxedList) >= sizeof(PyListObject), "");
@@ -639,6 +645,8 @@ public:
         return rtn;
     }
 
+    static void gcHandler(GCVisitor* v, Box* b);
+
 private:
     BoxedTuple() {}
 
@@ -697,6 +705,8 @@ public:
             return p->second;
         return NULL;
     }
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 static_assert(sizeof(BoxedDict) == sizeof(PyDictObject), "");
 
@@ -737,6 +747,8 @@ public:
                   Box* globals = NULL);
 
     DEFAULT_CLASS(function_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 class BoxedBuiltinFunctionOrMethod : public BoxedFunctionBase {
@@ -790,6 +802,8 @@ public:
     BoxedSlice(Box* lower, Box* upper, Box* step) : start(lower), stop(upper), step(step) {}
 
     DEFAULT_CLASS_SIMPLE(slice_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 static_assert(sizeof(BoxedSlice) == sizeof(PySliceObject), "");
 static_assert(offsetof(BoxedSlice, start) == offsetof(PySliceObject, start), "");
@@ -855,6 +869,8 @@ public:
         : prop_get(get), prop_set(set), prop_del(del), prop_doc(doc) {}
 
     DEFAULT_CLASS_SIMPLE(property_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 class BoxedStaticmethod : public Box {
@@ -864,6 +880,8 @@ public:
     BoxedStaticmethod(Box* callable) : sm_callable(callable){};
 
     DEFAULT_CLASS_SIMPLE(staticmethod_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 class BoxedClassmethod : public Box {
@@ -873,6 +891,8 @@ public:
     BoxedClassmethod(Box* callable) : cm_callable(callable){};
 
     DEFAULT_CLASS_SIMPLE(classmethod_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 // TODO is there any particular reason to make this a Box, i.e. a python-level object?
@@ -896,6 +916,8 @@ public:
         memset((void*)rtn->elts, 0, sizeof(Box*) * nelts);
         return rtn;
     }
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 class BoxedGenerator : public Box {
@@ -923,6 +945,8 @@ public:
     BoxedGenerator(BoxedFunctionBase* function, Box* arg1, Box* arg2, Box* arg3, Box** args);
 
     DEFAULT_CLASS(generator_cls);
+
+    static void gcHandler(GCVisitor* v, Box* b);
 };
 
 struct wrapper_def {