Fix some exception related leaks

from_cpython/Objects/exceptions.c

@@ -87,18 +87,28 @@ PyObject* PyErr_CreateExceptionInstance(PyObject* _type, PyObject* arg) {
         PyObject_InitHcAttrs(&self->hcattrs);
         if (arg) {
             self->args = PyTuple_Pack(1, arg);
-            if (!self->args)
+            if (!self->args) {
+                Py_DECREF(self);
                 return NULL;
+            }
             self->message = arg;
         } else {
             self->args = PyTuple_New(0);
+            if (!self->args) {
+                Py_DECREF(self);
+                return NULL;
+            }
             self->message = PyString_FromString("");
-            if (!self->message)
+            if (!self->message) {
+                Py_DECREF(self->args);
+                Py_DECREF(self);
                 return NULL;
+            }
         }
         return (PyObject*)self;
     } else {
         // Fallback
+        PyObject* rtn;
         PyObject* args;
         if (arg == NULL)
             args = PyTuple_New(0);
@@ -108,7 +118,9 @@ PyObject* PyErr_CreateExceptionInstance(PyObject* _type, PyObject* arg) {
         if (args == NULL)
             return NULL;
 
-        return PyObject_Call(_type, args, NULL);
+        rtn = PyObject_Call(_type, args, NULL);
+        Py_DECREF(args);
+        return rtn;
     }
 }
 

src/runtime/exceptions.cpp

@@ -45,6 +45,7 @@ void raiseSyntaxError(const char* msg, int lineno, int col_offset, llvm::StringR
         AUTO_DECREF(loc);
 
         auto args = BoxedTuple::create({ autoDecref(boxString(file)), autoDecref(boxInt(lineno)), None, loc });
+        AUTO_DECREF(args);
         Box* exc = runtimeCall(SyntaxError, ArgPassSpec(2), autoDecref(boxString(msg)), args, NULL, NULL, NULL);
         assert(!PyErr_Occurred());
         throw ExcInfo(incref(exc->cls), exc, NULL);