bpo-43687: Py_Initialize() creates singletons earlier (GH-25147)

Reorganize pycore_interp_init() to initialize singletons before the
the first PyType_Ready() call. Fix an issue when Python is configured
using --without-doc-strings.

1 files changed, 72 insertions, 44 deletions

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 8309477..64723ce 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -628,43 +628,67 @@ pycore_create_interpreter(_PyRuntimeState *runtime,
 
 
 static PyStatus
-pycore_init_types(PyInterpreterState *interp)
+pycore_init_singletons(PyInterpreterState *interp)
 {
     PyStatus status;
-    int is_main_interp = _Py_IsMainInterpreter(interp);
 
-    status = _PyGC_Init(interp);
+    if (_PyLong_Init(interp) < 0) {
+        return _PyStatus_ERR("can't init longs");
+    }
+
+    if (_Py_IsMainInterpreter(interp)) {
+        _PyFloat_Init();
+    }
+
+    status = _PyBytes_Init(interp);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
+
+    status = _PyUnicode_Init(interp);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
 
-    // Create the empty tuple singleton. It must be created before the first
-    // PyType_Ready() call since PyType_Ready() creates tuples, for tp_bases
-    // for example.
     status = _PyTuple_Init(interp);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
 
+    return _PyStatus_OK();
+}
+
+
+static PyStatus
+pycore_init_types(PyInterpreterState *interp)
+{
+    PyStatus status;
+    int is_main_interp = _Py_IsMainInterpreter(interp);
+
     if (is_main_interp) {
+        if (_PyStructSequence_Init() < 0) {
+            return _PyStatus_ERR("can't initialize structseq");
+        }
+
         status = _PyTypes_Init();
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
-    }
 
-    if (!_PyLong_Init(interp)) {
-        return _PyStatus_ERR("can't init longs");
-    }
+        if (_PyLong_InitTypes() < 0) {
+            return _PyStatus_ERR("can't init int type");
+        }
 
-    status = _PyUnicode_Init(interp);
-    if (_PyStatus_EXCEPTION(status)) {
-        return status;
+        status = _PyUnicode_InitTypes();
+        if (_PyStatus_EXCEPTION(status)) {
+            return status;
+        }
     }
 
-    status = _PyBytes_Init(interp);
-    if (_PyStatus_EXCEPTION(status)) {
-        return status;
+    if (is_main_interp) {
+        if (_PyFloat_InitTypes() < 0) {
+            return _PyStatus_ERR("can't init float");
+        }
     }
 
     status = _PyExc_Init(interp);
@@ -672,17 +696,7 @@ pycore_init_types(PyInterpreterState *interp)
         return status;
     }
 
-    if (is_main_interp) {
-        if (!_PyFloat_Init()) {
-            return _PyStatus_ERR("can't init float");
-        }
-
-        if (_PyStructSequence_Init() < 0) {
-            return _PyStatus_ERR("can't initialize structseq");
-        }
-    }
-
-    status = _PyErr_Init();
+    status = _PyErr_InitTypes();
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -693,22 +707,15 @@ pycore_init_types(PyInterpreterState *interp)
         }
     }
 
-    if (_PyWarnings_InitState(interp) < 0) {
-        return _PyStatus_ERR("can't initialize warnings");
-    }
-
-    status = _PyAtExit_Init(interp);
-    if (_PyStatus_EXCEPTION(status)) {
-        return status;
-    }
-
     return _PyStatus_OK();
 }
 
 
 static PyStatus
-pycore_init_builtins(PyInterpreterState *interp)
+pycore_init_builtins(PyThreadState *tstate)
 {
+    PyInterpreterState *interp = tstate->interp;
+
     PyObject *bimod = _PyBuiltin_Init(interp);
     if (bimod == NULL) {
         goto error;
@@ -744,6 +751,7 @@ pycore_init_builtins(PyInterpreterState *interp)
     }
     interp->import_func = Py_NewRef(import_func);
 
+    assert(!_PyErr_Occurred(tstate));
     return _PyStatus_OK();
 
 error:
@@ -755,29 +763,49 @@ error:
 static PyStatus
 pycore_interp_init(PyThreadState *tstate)
 {
+    PyInterpreterState *interp = tstate->interp;
     PyStatus status;
     PyObject *sysmod = NULL;
 
-    status = pycore_init_types(tstate->interp);
+    // Create singletons before the first PyType_Ready() call, since
+    // PyType_Ready() uses singletons like the Unicode empty string (tp_doc)
+    // and the empty tuple singletons (tp_bases).
+    status = pycore_init_singletons(interp);
     if (_PyStatus_EXCEPTION(status)) {
-        goto done;
+        return status;
     }
 
-    status = _PySys_Create(tstate, &sysmod);
+    // The GC must be initialized before the first GC collection.
+    status = _PyGC_Init(interp);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
+
+    status = pycore_init_types(interp);
     if (_PyStatus_EXCEPTION(status)) {
         goto done;
     }
 
-    assert(!_PyErr_Occurred(tstate));
+    if (_PyWarnings_InitState(interp) < 0) {
+        return _PyStatus_ERR("can't initialize warnings");
+    }
+
+    status = _PyAtExit_Init(interp);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
 
-    status = pycore_init_builtins(tstate->interp);
+    status = _PySys_Create(tstate, &sysmod);
     if (_PyStatus_EXCEPTION(status)) {
         goto done;
     }
 
-    assert(!_PyErr_Occurred(tstate));
+    status = pycore_init_builtins(tstate);
+    if (_PyStatus_EXCEPTION(status)) {
+        goto done;
+    }
 
-    const PyConfig *config = _PyInterpreterState_GetConfig(tstate->interp);
+    const PyConfig *config = _PyInterpreterState_GetConfig(interp);
     if (config->_install_importlib) {
         /* This call sets up builtin and frozen import support */
         if (init_importlib(tstate, sysmod) < 0) {