Try to get more context trying to tp_traverse a free'd type

Author: timfel

graalpython/com.oracle.graal.python.cext/src/gcmodule.c

@@ -49,6 +49,18 @@ call_traverse(traverseproc traverse, PyObject *op, visitproc visit, void *arg)
                       Py_TYPE((op))->tp_name);
         return 0;
     } else {
+        if (_PyObject_IsFreed((PyObject *)Py_TYPE(op))) {
+            if (_PyObject_IsFreed(op)) {
+                PyTruffle_Log(PY_TRUFFLE_LOG_INFO,
+                              "we tried to call tp_traverse on a freed object at %p (ctx %p)!",
+                              op, arg);
+            } else {
+                PyTruffle_Log(PY_TRUFFLE_LOG_INFO,
+                              "we tried to call tp_traverse on an object at %p with a freed type at %p (ctx %p)!",
+                              op, Py_TYPE(op), arg);
+            }
+            return 0;
+        }
         return traverse(op, (visitproc)visit, arg);
     }
 

graalpython/com.oracle.graal.python.cext/src/longobject.c

@@ -1961,7 +1961,7 @@ PyLong_FromString(const char *str, char **pend, int base)
     // is a small integer cache and if we're lucky we can just return from
     // that.
     // In base 2, up to 8 digits may be a small integer, in base 36 8 digits
-    // still fit in 64 bits
+    // still fit easily in 64 bits
     for (int i = 0; i < 8; i++) {
         char c = str[i];
         if (c == '\0') {