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().

3 files changed, 225 insertions, 213 deletions

diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index 3926095..6672136 100644
--- a/Objects/bytearrayobject.c
+++ b/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 */
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 002a602..8d81566 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -2299,7 +2299,7 @@ MemoryError_dealloc(PyBaseExceptionObject *self)
     }
 }
 
-static void
+static int
 preallocate_memerrors(void)
 {
     /* We create enough MemoryErrors and then decref them, which will fill
@@ -2309,12 +2309,14 @@ preallocate_memerrors(void)
     for (i = 0; i < MEMERRORS_SAVE; i++) {
         errors[i] = MemoryError_new((PyTypeObject *) PyExc_MemoryError,
                                     NULL, NULL);
-        if (!errors[i])
-            Py_FatalError("Could not preallocate MemoryError object");
+        if (!errors[i]) {
+            return -1;
+        }
     }
     for (i = 0; i < MEMERRORS_SAVE; i++) {
         Py_DECREF(errors[i]);
     }
+    return 0;
 }
 
 static void
@@ -2433,31 +2435,6 @@ SimpleExtendsException(PyExc_Warning, ResourceWarning,
 
 
 
-#define PRE_INIT(TYPE) \
-    if (!(_PyExc_ ## TYPE.tp_flags & Py_TPFLAGS_READY)) { \
-        if (PyType_Ready(&_PyExc_ ## TYPE) < 0) \
-            Py_FatalError("exceptions bootstrapping error."); \
-        Py_INCREF(PyExc_ ## TYPE); \
-    }
-
-#define POST_INIT(TYPE) \
-    if (PyDict_SetItemString(bdict, # TYPE, PyExc_ ## TYPE)) \
-        Py_FatalError("Module dictionary insertion problem.");
-
-#define INIT_ALIAS(NAME, TYPE) Py_INCREF(PyExc_ ## TYPE); \
-    Py_XDECREF(PyExc_ ## NAME); \
-    PyExc_ ## NAME = PyExc_ ## TYPE; \
-    if (PyDict_SetItemString(bdict, # NAME, PyExc_ ## NAME)) \
-        Py_FatalError("Module dictionary insertion problem.");
-
-#define ADD_ERRNO(TYPE, CODE) { \
-    PyObject *_code = PyLong_FromLong(CODE); \
-    assert(_PyObject_RealIsSubclass(PyExc_ ## TYPE, PyExc_OSError)); \
-    if (!_code || PyDict_SetItem(errnomap, _code, PyExc_ ## TYPE)) \
-        Py_FatalError("errmap insertion problem."); \
-    Py_DECREF(_code); \
-    }
-
 #ifdef MS_WINDOWS
 #include <winsock2.h>
 /* The following constants were added to errno.h in VS2010 but have
@@ -2514,184 +2491,226 @@ SimpleExtendsException(PyExc_Warning, ResourceWarning,
 #endif
 #endif /* MS_WINDOWS */
 
-void
+_PyInitError
 _PyExc_Init(PyObject *bltinmod)
 {
+#define PRE_INIT(TYPE) \
+    if (!(_PyExc_ ## TYPE.tp_flags & Py_TPFLAGS_READY)) { \
+        if (PyType_Ready(&_PyExc_ ## TYPE) < 0) { \
+            return _Py_INIT_ERR("exceptions bootstrapping error."); \
+        } \
+        Py_INCREF(PyExc_ ## TYPE); \
+    }
+
+#define POST_INIT(TYPE) \
+    if (PyDict_SetItemString(bdict, # TYPE, PyExc_ ## TYPE)) { \
+        return _Py_INIT_ERR("Module dictionary insertion problem."); \
+    }
+
+#define INIT_ALIAS(NAME, TYPE) \
+    do { \
+        Py_INCREF(PyExc_ ## TYPE); \
+        Py_XDECREF(PyExc_ ## NAME); \
+        PyExc_ ## NAME = PyExc_ ## TYPE; \
+        if (PyDict_SetItemString(bdict, # NAME, PyExc_ ## NAME)) { \
+            return _Py_INIT_ERR("Module dictionary insertion problem."); \
+        } \
+    } while (0)
+
+#define ADD_ERRNO(TYPE, CODE) \
+    do { \
+        PyObject *_code = PyLong_FromLong(CODE); \
+        assert(_PyObject_RealIsSubclass(PyExc_ ## TYPE, PyExc_OSError)); \
+        if (!_code || PyDict_SetItem(errnomap, _code, PyExc_ ## TYPE)) \
+            return _Py_INIT_ERR("errmap insertion problem."); \
+        Py_DECREF(_code); \
+    } while (0)
+
     PyObject *bdict;
 
-    PRE_INIT(BaseException)
-    PRE_INIT(Exception)
-    PRE_INIT(TypeError)
-    PRE_INIT(StopAsyncIteration)
-    PRE_INIT(StopIteration)
-    PRE_INIT(GeneratorExit)
-    PRE_INIT(SystemExit)
-    PRE_INIT(KeyboardInterrupt)
-    PRE_INIT(ImportError)
-    PRE_INIT(ModuleNotFoundError)
-    PRE_INIT(OSError)
-    PRE_INIT(EOFError)
-    PRE_INIT(RuntimeError)
-    PRE_INIT(RecursionError)
-    PRE_INIT(NotImplementedError)
-    PRE_INIT(NameError)
-    PRE_INIT(UnboundLocalError)
-    PRE_INIT(AttributeError)
-    PRE_INIT(SyntaxError)
-    PRE_INIT(IndentationError)
-    PRE_INIT(TabError)
-    PRE_INIT(LookupError)
-    PRE_INIT(IndexError)
-    PRE_INIT(KeyError)
-    PRE_INIT(ValueError)
-    PRE_INIT(UnicodeError)
-    PRE_INIT(UnicodeEncodeError)
-    PRE_INIT(UnicodeDecodeError)
-    PRE_INIT(UnicodeTranslateError)
-    PRE_INIT(AssertionError)
-    PRE_INIT(ArithmeticError)
-    PRE_INIT(FloatingPointError)
-    PRE_INIT(OverflowError)
-    PRE_INIT(ZeroDivisionError)
-    PRE_INIT(SystemError)
-    PRE_INIT(ReferenceError)
-    PRE_INIT(MemoryError)
-    PRE_INIT(BufferError)
-    PRE_INIT(Warning)
-    PRE_INIT(UserWarning)
-    PRE_INIT(DeprecationWarning)
-    PRE_INIT(PendingDeprecationWarning)
-    PRE_INIT(SyntaxWarning)
-    PRE_INIT(RuntimeWarning)
-    PRE_INIT(FutureWarning)
-    PRE_INIT(ImportWarning)
-    PRE_INIT(UnicodeWarning)
-    PRE_INIT(BytesWarning)
-    PRE_INIT(ResourceWarning)
+    PRE_INIT(BaseException);
+    PRE_INIT(Exception);
+    PRE_INIT(TypeError);
+    PRE_INIT(StopAsyncIteration);
+    PRE_INIT(StopIteration);
+    PRE_INIT(GeneratorExit);
+    PRE_INIT(SystemExit);
+    PRE_INIT(KeyboardInterrupt);
+    PRE_INIT(ImportError);
+    PRE_INIT(ModuleNotFoundError);
+    PRE_INIT(OSError);
+    PRE_INIT(EOFError);
+    PRE_INIT(RuntimeError);
+    PRE_INIT(RecursionError);
+    PRE_INIT(NotImplementedError);
+    PRE_INIT(NameError);
+    PRE_INIT(UnboundLocalError);
+    PRE_INIT(AttributeError);
+    PRE_INIT(SyntaxError);
+    PRE_INIT(IndentationError);
+    PRE_INIT(TabError);
+    PRE_INIT(LookupError);
+    PRE_INIT(IndexError);
+    PRE_INIT(KeyError);
+    PRE_INIT(ValueError);
+    PRE_INIT(UnicodeError);
+    PRE_INIT(UnicodeEncodeError);
+    PRE_INIT(UnicodeDecodeError);
+    PRE_INIT(UnicodeTranslateError);
+    PRE_INIT(AssertionError);
+    PRE_INIT(ArithmeticError);
+    PRE_INIT(FloatingPointError);
+    PRE_INIT(OverflowError);
+    PRE_INIT(ZeroDivisionError);
+    PRE_INIT(SystemError);
+    PRE_INIT(ReferenceError);
+    PRE_INIT(MemoryError);
+    PRE_INIT(BufferError);
+    PRE_INIT(Warning);
+    PRE_INIT(UserWarning);
+    PRE_INIT(DeprecationWarning);
+    PRE_INIT(PendingDeprecationWarning);
+    PRE_INIT(SyntaxWarning);
+    PRE_INIT(RuntimeWarning);
+    PRE_INIT(FutureWarning);
+    PRE_INIT(ImportWarning);
+    PRE_INIT(UnicodeWarning);
+    PRE_INIT(BytesWarning);
+    PRE_INIT(ResourceWarning);
 
     /* OSError subclasses */
-    PRE_INIT(ConnectionError)
-
-    PRE_INIT(BlockingIOError)
-    PRE_INIT(BrokenPipeError)
-    PRE_INIT(ChildProcessError)
-    PRE_INIT(ConnectionAbortedError)
-    PRE_INIT(ConnectionRefusedError)
-    PRE_INIT(ConnectionResetError)
-    PRE_INIT(FileExistsError)
-    PRE_INIT(FileNotFoundError)
-    PRE_INIT(IsADirectoryError)
-    PRE_INIT(NotADirectoryError)
-    PRE_INIT(InterruptedError)
-    PRE_INIT(PermissionError)
-    PRE_INIT(ProcessLookupError)
-    PRE_INIT(TimeoutError)
+    PRE_INIT(ConnectionError);
+
+    PRE_INIT(BlockingIOError);
+    PRE_INIT(BrokenPipeError);
+    PRE_INIT(ChildProcessError);
+    PRE_INIT(ConnectionAbortedError);
+    PRE_INIT(ConnectionRefusedError);
+    PRE_INIT(ConnectionResetError);
+    PRE_INIT(FileExistsError);
+    PRE_INIT(FileNotFoundError);
+    PRE_INIT(IsADirectoryError);
+    PRE_INIT(NotADirectoryError);
+    PRE_INIT(InterruptedError);
+    PRE_INIT(PermissionError);
+    PRE_INIT(ProcessLookupError);
+    PRE_INIT(TimeoutError);
 
     bdict = PyModule_GetDict(bltinmod);
-    if (bdict == NULL)
-        Py_FatalError("exceptions bootstrapping error.");
-
-    POST_INIT(BaseException)
-    POST_INIT(Exception)
-    POST_INIT(TypeError)
-    POST_INIT(StopAsyncIteration)
-    POST_INIT(StopIteration)
-    POST_INIT(GeneratorExit)
-    POST_INIT(SystemExit)
-    POST_INIT(KeyboardInterrupt)
-    POST_INIT(ImportError)
-    POST_INIT(ModuleNotFoundError)
-    POST_INIT(OSError)
-    INIT_ALIAS(EnvironmentError, OSError)
-    INIT_ALIAS(IOError, OSError)
+    if (bdict == NULL) {
+        return _Py_INIT_ERR("exceptions bootstrapping error.");
+    }
+
+    POST_INIT(BaseException);
+    POST_INIT(Exception);
+    POST_INIT(TypeError);
+    POST_INIT(StopAsyncIteration);
+    POST_INIT(StopIteration);
+    POST_INIT(GeneratorExit);
+    POST_INIT(SystemExit);
+    POST_INIT(KeyboardInterrupt);
+    POST_INIT(ImportError);
+    POST_INIT(ModuleNotFoundError);
+    POST_INIT(OSError);
+    INIT_ALIAS(EnvironmentError, OSError);
+    INIT_ALIAS(IOError, OSError);
 #ifdef MS_WINDOWS
-    INIT_ALIAS(WindowsError, OSError)
+    INIT_ALIAS(WindowsError, OSError);
 #endif
-    POST_INIT(EOFError)
-    POST_INIT(RuntimeError)
-    POST_INIT(RecursionError)
-    POST_INIT(NotImplementedError)
-    POST_INIT(NameError)
-    POST_INIT(UnboundLocalError)
-    POST_INIT(AttributeError)
-    POST_INIT(SyntaxError)
-    POST_INIT(IndentationError)
-    POST_INIT(TabError)
-    POST_INIT(LookupError)
-    POST_INIT(IndexError)
-    POST_INIT(KeyError)
-    POST_INIT(ValueError)
-    POST_INIT(UnicodeError)
-    POST_INIT(UnicodeEncodeError)
-    POST_INIT(UnicodeDecodeError)
-    POST_INIT(UnicodeTranslateError)
-    POST_INIT(AssertionError)
-    POST_INIT(ArithmeticError)
-    POST_INIT(FloatingPointError)
-    POST_INIT(OverflowError)
-    POST_INIT(ZeroDivisionError)
-    POST_INIT(SystemError)
-    POST_INIT(ReferenceError)
-    POST_INIT(MemoryError)
-    POST_INIT(BufferError)
-    POST_INIT(Warning)
-    POST_INIT(UserWarning)
-    POST_INIT(DeprecationWarning)
-    POST_INIT(PendingDeprecationWarning)
-    POST_INIT(SyntaxWarning)
-    POST_INIT(RuntimeWarning)
-    POST_INIT(FutureWarning)
-    POST_INIT(ImportWarning)
-    POST_INIT(UnicodeWarning)
-    POST_INIT(BytesWarning)
-    POST_INIT(ResourceWarning)
+    POST_INIT(EOFError);
+    POST_INIT(RuntimeError);
+    POST_INIT(RecursionError);
+    POST_INIT(NotImplementedError);
+    POST_INIT(NameError);
+    POST_INIT(UnboundLocalError);
+    POST_INIT(AttributeError);
+    POST_INIT(SyntaxError);
+    POST_INIT(IndentationError);
+    POST_INIT(TabError);
+    POST_INIT(LookupError);
+    POST_INIT(IndexError);
+    POST_INIT(KeyError);
+    POST_INIT(ValueError);
+    POST_INIT(UnicodeError);
+    POST_INIT(UnicodeEncodeError);
+    POST_INIT(UnicodeDecodeError);
+    POST_INIT(UnicodeTranslateError);
+    POST_INIT(AssertionError);
+    POST_INIT(ArithmeticError);
+    POST_INIT(FloatingPointError);
+    POST_INIT(OverflowError);
+    POST_INIT(ZeroDivisionError);
+    POST_INIT(SystemError);
+    POST_INIT(ReferenceError);
+    POST_INIT(MemoryError);
+    POST_INIT(BufferError);
+    POST_INIT(Warning);
+    POST_INIT(UserWarning);
+    POST_INIT(DeprecationWarning);
+    POST_INIT(PendingDeprecationWarning);
+    POST_INIT(SyntaxWarning);
+    POST_INIT(RuntimeWarning);
+    POST_INIT(FutureWarning);
+    POST_INIT(ImportWarning);
+    POST_INIT(UnicodeWarning);
+    POST_INIT(BytesWarning);
+    POST_INIT(ResourceWarning);
 
     if (!errnomap) {
         errnomap = PyDict_New();
-        if (!errnomap)
-            Py_FatalError("Cannot allocate map from errnos to OSError subclasses");
+        if (!errnomap) {
+            return _Py_INIT_ERR("Cannot allocate map from errnos to OSError subclasses");
+        }
     }
 
     /* OSError subclasses */
-    POST_INIT(ConnectionError)
-
-    POST_INIT(BlockingIOError)
-    ADD_ERRNO(BlockingIOError, EAGAIN)
-    ADD_ERRNO(BlockingIOError, EALREADY)
-    ADD_ERRNO(BlockingIOError, EINPROGRESS)
-    ADD_ERRNO(BlockingIOError, EWOULDBLOCK)
-    POST_INIT(BrokenPipeError)
-    ADD_ERRNO(BrokenPipeError, EPIPE)
+    POST_INIT(ConnectionError);
+
+    POST_INIT(BlockingIOError);
+    ADD_ERRNO(BlockingIOError, EAGAIN);
+    ADD_ERRNO(BlockingIOError, EALREADY);
+    ADD_ERRNO(BlockingIOError, EINPROGRESS);
+    ADD_ERRNO(BlockingIOError, EWOULDBLOCK);
+    POST_INIT(BrokenPipeError);
+    ADD_ERRNO(BrokenPipeError, EPIPE);
 #ifdef ESHUTDOWN
-    ADD_ERRNO(BrokenPipeError, ESHUTDOWN)
+    ADD_ERRNO(BrokenPipeError, ESHUTDOWN);
 #endif
-    POST_INIT(ChildProcessError)
-    ADD_ERRNO(ChildProcessError, ECHILD)
-    POST_INIT(ConnectionAbortedError)
-    ADD_ERRNO(ConnectionAbortedError, ECONNABORTED)
-    POST_INIT(ConnectionRefusedError)
-    ADD_ERRNO(ConnectionRefusedError, ECONNREFUSED)
-    POST_INIT(ConnectionResetError)
-    ADD_ERRNO(ConnectionResetError, ECONNRESET)
-    POST_INIT(FileExistsError)
-    ADD_ERRNO(FileExistsError, EEXIST)
-    POST_INIT(FileNotFoundError)
-    ADD_ERRNO(FileNotFoundError, ENOENT)
-    POST_INIT(IsADirectoryError)
-    ADD_ERRNO(IsADirectoryError, EISDIR)
-    POST_INIT(NotADirectoryError)
-    ADD_ERRNO(NotADirectoryError, ENOTDIR)
-    POST_INIT(InterruptedError)
-    ADD_ERRNO(InterruptedError, EINTR)
-    POST_INIT(PermissionError)
-    ADD_ERRNO(PermissionError, EACCES)
-    ADD_ERRNO(PermissionError, EPERM)
-    POST_INIT(ProcessLookupError)
-    ADD_ERRNO(ProcessLookupError, ESRCH)
-    POST_INIT(TimeoutError)
-    ADD_ERRNO(TimeoutError, ETIMEDOUT)
-
-    preallocate_memerrors();
+    POST_INIT(ChildProcessError);
+    ADD_ERRNO(ChildProcessError, ECHILD);
+    POST_INIT(ConnectionAbortedError);
+    ADD_ERRNO(ConnectionAbortedError, ECONNABORTED);
+    POST_INIT(ConnectionRefusedError);
+    ADD_ERRNO(ConnectionRefusedError, ECONNREFUSED);
+    POST_INIT(ConnectionResetError);
+    ADD_ERRNO(ConnectionResetError, ECONNRESET);
+    POST_INIT(FileExistsError);
+    ADD_ERRNO(FileExistsError, EEXIST);
+    POST_INIT(FileNotFoundError);
+    ADD_ERRNO(FileNotFoundError, ENOENT);
+    POST_INIT(IsADirectoryError);
+    ADD_ERRNO(IsADirectoryError, EISDIR);
+    POST_INIT(NotADirectoryError);
+    ADD_ERRNO(NotADirectoryError, ENOTDIR);
+    POST_INIT(InterruptedError);
+    ADD_ERRNO(InterruptedError, EINTR);
+    POST_INIT(PermissionError);
+    ADD_ERRNO(PermissionError, EACCES);
+    ADD_ERRNO(PermissionError, EPERM);
+    POST_INIT(ProcessLookupError);
+    ADD_ERRNO(ProcessLookupError, ESRCH);
+    POST_INIT(TimeoutError);
+    ADD_ERRNO(TimeoutError, ETIMEDOUT);
+
+    if (preallocate_memerrors() < 0) {
+        return _Py_INIT_ERR("Could not preallocate MemoryError object");
+    }
+    return _Py_INIT_OK();
+
+#undef PRE_INIT
+#undef POST_INIT
+#undef INIT_ALIAS
+#undef ADD_ERRNO
 }
 
 void
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index f1d23b6..ea7bcab 100644
--- a/Objects/unicodeobject.c
+++ b/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 */