bpo-35713: Rework Python initialization (GH-11647)

* The PyByteArray_Init() and PyByteArray_Fini() functions have been
  removed. They did nothing since Python 2.7.4 and Python 3.2.0, were
  excluded from the limited API (stable ABI), and were not
  documented.
* Move "_PyXXX_Init()" and "_PyXXX_Fini()" declarations from
  Include/cpython/pylifecycle.h to
  Include/internal/pycore_pylifecycle.h. Replace
  "PyAPI_FUNC(TYPE)" with "extern TYPE".
* _PyExc_Init() now returns an error on failure rather than calling
  Py_FatalError(). Move macros inside _PyExc_Init() and undefine them
  when done. Rewrite macros to make them look more like statement:
  add ";" when using them, add "do { ... } while (0)".
* _PyUnicode_Init() now returns a _PyInitError error rather than call
  Py_FatalError().
* Move stdin check from _PySys_BeginInit() to init_sys_streams().
* _Py_ReadyTypes() now returns a _PyInitError error rather than
  calling Py_FatalError().

Doc/whatsnew/3.8.rst

@@ -328,6 +328,10 @@ Optimizations
 Build and C API Changes
 =======================
 
+* The :c:func:`PyByteArray_Init` and :c:func:`PyByteArray_Fini` functions have
+  been removed. They did nothing since Python 2.7.4 and Python 3.2.0, were
+  excluded from the limited API (stable ABI), and were not documented.
+
 * The result of :c:func:`PyExceptionClass_Name` is now of type
   ``const char *`` rather of ``char *``.
   (Contributed by Serhiy Storchaka in :issue:`33818`.)

Include/cpython/pylifecycle.h

@@ -56,33 +56,6 @@ PyAPI_FUNC(void) _Py_SetProgramFullPath(const wchar_t *);
 PyAPI_FUNC(const char *) _Py_gitidentifier(void);
 PyAPI_FUNC(const char *) _Py_gitversion(void);
 
-/* Internal -- various one-time initializations */
-PyAPI_FUNC(PyObject *) _PyBuiltin_Init(void);
-PyAPI_FUNC(_PyInitError) _PySys_BeginInit(PyObject **sysmod);
-PyAPI_FUNC(int) _PySys_EndInit(PyObject *sysdict, PyInterpreterState *interp);
-PyAPI_FUNC(_PyInitError) _PyImport_Init(PyInterpreterState *interp);
-PyAPI_FUNC(void) _PyExc_Init(PyObject * bltinmod);
-PyAPI_FUNC(_PyInitError) _PyImportHooks_Init(void);
-PyAPI_FUNC(int) _PyFloat_Init(void);
-PyAPI_FUNC(int) PyByteArray_Init(void);
-PyAPI_FUNC(_PyInitError) _Py_HashRandomization_Init(const _PyCoreConfig *);
-
-/* Various internal finalizers */
-
-PyAPI_FUNC(void) PyMethod_Fini(void);
-PyAPI_FUNC(void) PyFrame_Fini(void);
-PyAPI_FUNC(void) PyCFunction_Fini(void);
-PyAPI_FUNC(void) PyDict_Fini(void);
-PyAPI_FUNC(void) PyTuple_Fini(void);
-PyAPI_FUNC(void) PyList_Fini(void);
-PyAPI_FUNC(void) PySet_Fini(void);
-PyAPI_FUNC(void) PyBytes_Fini(void);
-PyAPI_FUNC(void) PyByteArray_Fini(void);
-PyAPI_FUNC(void) PyFloat_Fini(void);
-PyAPI_FUNC(void) PyOS_FiniInterrupts(void);
-PyAPI_FUNC(void) PySlice_Fini(void);
-PyAPI_FUNC(void) PyAsyncGen_Fini(void);
-
 PyAPI_FUNC(int) _Py_IsFinalizing(void);
 
 /* Random */

Include/internal/pycore_pylifecycle.h

@@ -19,20 +19,45 @@ PyAPI_FUNC(void) _Py_ClearStandardStreamEncoding(void);
 
 PyAPI_FUNC(int) _Py_IsLocaleCoercionTarget(const char *ctype_loc);
 
-extern int _PyUnicode_Init(void);
+/* Various one-time initializers */
+
+extern _PyInitError _PyUnicode_Init(void);
 extern int _PyStructSequence_Init(void);
 extern int _PyLong_Init(void);
 extern _PyInitError _PyFaulthandler_Init(int enable);
 extern int _PyTraceMalloc_Init(int enable);
+extern PyObject * _PyBuiltin_Init(void);
+extern _PyInitError _PySys_BeginInit(PyObject **sysmod);
+extern int _PySys_EndInit(PyObject *sysdict, PyInterpreterState *interp);
+extern _PyInitError _PyImport_Init(PyInterpreterState *interp);
+extern _PyInitError _PyExc_Init(PyObject * bltinmod);
+extern _PyInitError _PyImportHooks_Init(void);
+extern int _PyFloat_Init(void);
+extern _PyInitError _Py_HashRandomization_Init(const _PyCoreConfig *);
 
 extern void _Py_ReadyTypes(void);
 
-PyAPI_FUNC(void) _PyExc_Fini(void);
-PyAPI_FUNC(void) _PyImport_Fini(void);
-PyAPI_FUNC(void) _PyImport_Fini2(void);
-PyAPI_FUNC(void) _PyGC_Fini(void);
-PyAPI_FUNC(void) _PyType_Fini(void);
-PyAPI_FUNC(void) _Py_HashRandomization_Fini(void);
+/* Various internal finalizers */
+
+extern void PyMethod_Fini(void);
+extern void PyFrame_Fini(void);
+extern void PyCFunction_Fini(void);
+extern void PyDict_Fini(void);
+extern void PyTuple_Fini(void);
+extern void PyList_Fini(void);
+extern void PySet_Fini(void);
+extern void PyBytes_Fini(void);
+extern void PyFloat_Fini(void);
+extern void PyOS_FiniInterrupts(void);
+extern void PySlice_Fini(void);
+extern void PyAsyncGen_Fini(void);
+
+extern void _PyExc_Fini(void);
+extern void _PyImport_Fini(void);
+extern void _PyImport_Fini2(void);
+extern void _PyGC_Fini(void);
+extern void _PyType_Fini(void);
+extern void _Py_HashRandomization_Fini(void);
 extern void _PyUnicode_Fini(void);
 extern void PyLong_Fini(void);
 extern void _PyFaulthandler_Fini(void);

Misc/NEWS.d/next/C API/2019-01-22-17-04-10.bpo-35713.fmehdG.rst

+The :c:func:`PyByteArray_Init` and :c:func:`PyByteArray_Fini` functions have
+been removed. They did nothing since Python 2.7.4 and Python 3.2.0, were
+excluded from the limited API (stable ABI), and were not documented.

Objects/bytearrayobject.c

@@ -17,17 +17,6 @@ class bytearray "PyByteArrayObject *" "&PyByteArray_Type"
 
 char _PyByteArray_empty_string[] = "";
 
-void
-PyByteArray_Fini(void)
-{
-}
-
-int
-PyByteArray_Init(void)
-{
-    return 1;
-}
-
 /* end nullbytes support */
 
 /* Helpers */

Objects/unicodeobject.c

@@ -15199,7 +15199,8 @@ PyTypeObject PyUnicode_Type = {
 
 /* Initialize the Unicode implementation */
 
-int _PyUnicode_Init(void)
+_PyInitError
+_PyUnicode_Init(void)
 {
     /* XXX - move this array to unicodectype.c ? */
     Py_UCS2 linebreak[] = {
@@ -15215,28 +15216,31 @@ int _PyUnicode_Init(void)
 
     /* Init the implementation */
     _Py_INCREF_UNICODE_EMPTY();
-    if (!unicode_empty)
-        Py_FatalError("Can't create empty string");
+    if (!unicode_empty) {
+        return _Py_INIT_ERR("Can't create empty string");
+    }
     Py_DECREF(unicode_empty);
 
-    if (PyType_Ready(&PyUnicode_Type) < 0)
-        Py_FatalError("Can't initialize 'unicode'");
+    if (PyType_Ready(&PyUnicode_Type) < 0) {
+        return _Py_INIT_ERR("Can't initialize unicode type");
+    }
 
     /* initialize the linebreak bloom filter */
     bloom_linebreak = make_bloom_mask(
         PyUnicode_2BYTE_KIND, linebreak,
         Py_ARRAY_LENGTH(linebreak));
 
-    if (PyType_Ready(&EncodingMapType) < 0)
-         Py_FatalError("Can't initialize encoding map type");
-
-    if (PyType_Ready(&PyFieldNameIter_Type) < 0)
-        Py_FatalError("Can't initialize field name iterator type");
-
-    if (PyType_Ready(&PyFormatterIter_Type) < 0)
-        Py_FatalError("Can't initialize formatter iter type");
+    if (PyType_Ready(&EncodingMapType) < 0) {
+         return _Py_INIT_ERR("Can't initialize encoding map type");
+    }
+    if (PyType_Ready(&PyFieldNameIter_Type) < 0) {
+        return _Py_INIT_ERR("Can't initialize field name iterator type");
+    }
+    if (PyType_Ready(&PyFormatterIter_Type) < 0) {
+        return _Py_INIT_ERR("Can't initialize formatter iter type");
+    }
 
-    return 0;
+    return _Py_INIT_OK();
 }
 
 /* Finalize the Unicode implementation */

Python/pylifecycle.c

@@ -608,9 +608,6 @@ _Py_InitializeCore_impl(PyInterpreterState **interp_p,
     if (!_PyLong_Init())
         return _Py_INIT_ERR("can't init longs");
 
-    if (!PyByteArray_Init())
-        return _Py_INIT_ERR("can't init bytearray");
-
     if (!_PyFloat_Init())
         return _Py_INIT_ERR("can't init float");
 
@@ -634,9 +631,10 @@ _Py_InitializeCore_impl(PyInterpreterState **interp_p,
     PyDict_SetItemString(interp->sysdict, "modules", modules);
     _PyImport_FixupBuiltin(sysmod, "sys", modules);
 
-    /* Init Unicode implementation; relies on the codec registry */
-    if (_PyUnicode_Init() < 0)
-        return _Py_INIT_ERR("can't initialize unicode");
+    err = _PyUnicode_Init();
+    if (_Py_INIT_FAILED(err)) {
+        return err;
+    }
 
     if (_PyStructSequence_Init() < 0)
         return _Py_INIT_ERR("can't initialize structseq");
@@ -651,7 +649,10 @@ _Py_InitializeCore_impl(PyInterpreterState **interp_p,
     Py_INCREF(interp->builtins);
 
     /* initialize builtin exceptions */
-    _PyExc_Init(bimod);
+    err = _PyExc_Init(bimod);
+    if (_Py_INIT_FAILED(err)) {
+        return err;
+    }
 
     /* Set up a preliminary stderr printer until we have enough
        infrastructure for the io module in place. */
@@ -1146,7 +1147,6 @@ Py_FinalizeEx(void)
     PyList_Fini();
     PySet_Fini();
     PyBytes_Fini();
-    PyByteArray_Fini();
     PyLong_Fini();
     PyFloat_Fini();
     PyDict_Fini();
@@ -1302,7 +1302,10 @@ new_interpreter(PyThreadState **tstate_p)
     }
 
     /* initialize builtin exceptions */
-    _PyExc_Init(bimod);
+    err = _PyExc_Init(bimod);
+    if (_Py_INIT_FAILED(err)) {
+        return err;
+    }
 
     if (bimod != NULL && sysmod != NULL) {
         PyObject *pstderr;
@@ -1682,6 +1685,20 @@ init_sys_streams(PyInterpreterState *interp)
     _PyInitError res = _Py_INIT_OK();
     _PyCoreConfig *config = &interp->core_config;
 
+    /* Check that stdin is not a directory
+       Using shell redirection, you can redirect stdin to a directory,
+       crashing the Python interpreter. Catch this common mistake here
+       and output a useful error message. Note that under MS Windows,
+       the shell already prevents that. */
+#ifndef MS_WINDOWS
+    struct _Py_stat_struct sb;
+    if (_Py_fstat_noraise(fileno(stdin), &sb) == 0 &&
+        S_ISDIR(sb.st_mode)) {
+        return _Py_INIT_USER_ERR("<stdin> is a directory, "
+                                 "cannot continue");
+    }
+#endif
+
     char *codec_name = get_codec_name(config->stdio_encoding);
     if (codec_name == NULL) {
         return _Py_INIT_ERR("failed to get the Python codec name "

Python/sysmodule.c

@@ -2381,22 +2381,6 @@ _PySys_BeginInit(PyObject **sysmod)
     }
     sysdict = PyModule_GetDict(m);
 
-    /* Check that stdin is not a directory
-       Using shell redirection, you can redirect stdin to a directory,
-       crashing the Python interpreter. Catch this common mistake here
-       and output a useful error message. Note that under MS Windows,
-       the shell already prevents that. */
-#ifndef MS_WINDOWS
-    {
-        struct _Py_stat_struct sb;
-        if (_Py_fstat_noraise(fileno(stdin), &sb) == 0 &&
-            S_ISDIR(sb.st_mode)) {
-            return _Py_INIT_USER_ERR("<stdin> is a directory, "
-                                     "cannot continue");
-        }
-    }
-#endif
-
     /* stdin/stdout/stderr are set in pylifecycle.c */
 
     SET_SYS_FROM_STRING_BORROW("__displayhook__",