bpo-38631: Avoid Py_FatalError() in handle_legacy_finalizers() (GH-17266)

* Rename _PyGC_Initialize() to _PyGC_InitializeRuntime()
* Add _PyGC_Init(): initialize _PyRuntime.gc.garbage list
* Call _PyGC_Init() before _PyTypes_Init()

2 files changed, 12 insertions, 5 deletions

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 1bfc7c1..9739bb1 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -558,9 +558,16 @@ pycore_create_interpreter(_PyRuntimeState *runtime,
 
 
 static PyStatus
-pycore_init_types(void)
+pycore_init_types(_PyRuntimeState *runtime)
 {
-    PyStatus status = _PyTypes_Init();
+    PyStatus status;
+
+    status = _PyGC_Init(runtime);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
+
+    status = _PyTypes_Init();
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -683,7 +690,7 @@ pyinit_config(_PyRuntimeState *runtime,
     config = &tstate->interp->config;
     *tstate_p = tstate;
 
-    status = pycore_init_types();
+    status = pycore_init_types(runtime);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -1447,7 +1454,7 @@ new_interpreter(PyThreadState **tstate_p)
     }
     config = &interp->config;
 
-    status = pycore_init_types();
+    status = pycore_init_types(runtime);
 
     /* XXX The following is lax in error checking */
     PyObject *modules = PyDict_New();
diff --git a/Python/pystate.c b/Python/pystate.c
index b4b1247..06cc9a8 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -58,7 +58,7 @@ _PyRuntimeState_Init_impl(_PyRuntimeState *runtime)
     runtime->open_code_userdata = open_code_userdata;
     runtime->audit_hook_head = audit_hook_head;
 
-    _PyGC_Initialize(&runtime->gc);
+    _PyGC_InitializeRuntime(&runtime->gc);
     _PyEval_Initialize(&runtime->ceval);
 
     PyPreConfig_InitPythonConfig(&runtime->preconfig);