bpo-32030: Split Py_Main() into subfunctions (#4399)

* Don't use "Python runtime" anymore to parse command line options or
  to get environment variables: pymain_init() is now a strict
  separation.
* Use an error message rather than "crashing" directly with
  Py_FatalError(). Limit the number of calls to Py_FatalError(). It
  prepares the code to handle errors more nicely later.
* Warnings options (-W, PYTHONWARNINGS) and "XOptions" (-X) are now
  only added to the sys module once Python core is properly
  initialized.
* _PyMain is now the well identified owner of some important strings
  like: warnings options, XOptions, and the "program name". The
  program name string is now properly freed at exit.
  pymain_free() is now responsible to free the "command" string.
* Rename most methods in Modules/main.c to use a "pymain_" prefix to
  avoid conflits and ease debug.
* Replace _Py_CommandLineDetails_INIT with memset(0)
* Reorder a lot of code to fix the initialization ordering. For
  example, initializing standard streams now comes before parsing
  PYTHONWARNINGS.
* Py_Main() now handles errors when adding warnings options and
  XOptions.
* Add _PyMem_GetDefaultRawAllocator() private function.
* Cleanup _PyMem_Initialize(): remove useless global constants: move
  them into _PyMem_Initialize().
* Call _PyRuntime_Initialize() as soon as possible:
  _PyRuntime_Initialize() now returns an error message on failure.
* Add _PyInitError structure and following macros:

  * _Py_INIT_OK()
  * _Py_INIT_ERR(msg)
  * _Py_INIT_USER_ERR(msg): "user" error, don't abort() in that case
  * _Py_INIT_FAILED(err)

1 files changed, 41 insertions, 36 deletions

diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index 4441c82..699cce9 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -182,31 +182,17 @@ static struct {
 
 
 #define _PyMem_Raw _PyRuntime.mem.allocators.raw
-static const PyMemAllocatorEx _pymem_raw = {
-#ifdef Py_DEBUG
-    &_PyMem_Debug.raw, PYRAWDBG_FUNCS
-#else
-    NULL, PYRAW_FUNCS
-#endif
-    };
 
 #define _PyMem _PyRuntime.mem.allocators.mem
-static const PyMemAllocatorEx _pymem = {
-#ifdef Py_DEBUG
-    &_PyMem_Debug.mem, PYDBG_FUNCS
-#else
-    NULL, PYMEM_FUNCS
-#endif
-    };
 
 #define _PyObject _PyRuntime.mem.allocators.obj
-static const PyMemAllocatorEx _pyobject = {
-#ifdef Py_DEBUG
-    &_PyMem_Debug.obj, PYDBG_FUNCS
-#else
-    NULL, PYOBJ_FUNCS
-#endif
-    };
+
+void
+_PyMem_GetDefaultRawAllocator(PyMemAllocatorEx *alloc_p)
+{
+    PyMemAllocatorEx alloc = {NULL, PYRAW_FUNCS};
+    *alloc_p = alloc;
+}
 
 int
 _PyMem_SetupAllocators(const char *opt)
@@ -267,34 +253,52 @@ _PyMem_SetupAllocators(const char *opt)
     return 0;
 }
 
-#undef PYRAW_FUNCS
-#undef PYMEM_FUNCS
-#undef PYOBJ_FUNCS
-#undef PYRAWDBG_FUNCS
-#undef PYDBG_FUNCS
 
-static const PyObjectArenaAllocator _PyObject_Arena = {NULL,
+void
+_PyObject_Initialize(struct _pyobj_runtime_state *state)
+{
+    PyObjectArenaAllocator _PyObject_Arena = {NULL,
 #ifdef MS_WINDOWS
-    _PyObject_ArenaVirtualAlloc, _PyObject_ArenaVirtualFree
+        _PyObject_ArenaVirtualAlloc, _PyObject_ArenaVirtualFree
 #elif defined(ARENAS_USE_MMAP)
-    _PyObject_ArenaMmap, _PyObject_ArenaMunmap
+        _PyObject_ArenaMmap, _PyObject_ArenaMunmap
 #else
-    _PyObject_ArenaMalloc, _PyObject_ArenaFree
+        _PyObject_ArenaMalloc, _PyObject_ArenaFree
 #endif
     };
 
-void
-_PyObject_Initialize(struct _pyobj_runtime_state *state)
-{
     state->allocator_arenas = _PyObject_Arena;
 }
 
+
 void
 _PyMem_Initialize(struct _pymem_runtime_state *state)
 {
-    state->allocators.raw = _pymem_raw;
-    state->allocators.mem = _pymem;
-    state->allocators.obj = _pyobject;
+    PyMemAllocatorEx pymem_raw = {
+#ifdef Py_DEBUG
+        &_PyMem_Debug.raw, PYRAWDBG_FUNCS
+#else
+        NULL, PYRAW_FUNCS
+#endif
+    };
+    PyMemAllocatorEx pymem = {
+#ifdef Py_DEBUG
+        &_PyMem_Debug.mem, PYDBG_FUNCS
+#else
+        NULL, PYMEM_FUNCS
+#endif
+    };
+    PyMemAllocatorEx pyobject = {
+#ifdef Py_DEBUG
+        &_PyMem_Debug.obj, PYDBG_FUNCS
+#else
+        NULL, PYOBJ_FUNCS
+#endif
+    };
+
+    state->allocators.raw = pymem_raw;
+    state->allocators.mem = pymem;
+    state->allocators.obj = pyobject;
 
 #ifdef WITH_PYMALLOC
     Py_BUILD_ASSERT(NB_SMALL_SIZE_CLASSES == 64);
@@ -311,6 +315,7 @@ _PyMem_Initialize(struct _pymem_runtime_state *state)
 #endif /* WITH_PYMALLOC */
 }
 
+
 #ifdef WITH_PYMALLOC
 static int
 _PyMem_DebugEnabled(void)