This changeset fixes a number of compiler warnings in the Python Launcher
binary for OSX. It also cleans up whitespace usage in those sources.

This changeset fixes a number of compiler warnings in the Python Launcher
binary for OSX. It also cleans up whitespace usage in those sources.

Reformulated the textual change, and applied it to the docstring as well.

Reformulated the textual change, and applied it to the docstring as well.

According to VirtualFree() documentation, the size must be zero if the "free
type" is MEM_RELEASE.

a stack overflow in the marshal module (fix a crash in test_marshal).
Patch written by Jeremy Kloth.

Add new enum:

* PyMemAllocatorDomain

Add new structures:

* PyMemAllocator
* PyObjectArenaAllocator

Add new functions:

* PyMem_RawMalloc(), PyMem_RawRealloc(), PyMem_RawFree()
* PyMem_GetAllocator(), PyMem_SetAllocator()
* PyObject_GetArenaAllocator(), PyObject_SetArenaAllocator()
* PyMem_SetupDebugHooks()

Changes:

* PyMem_Malloc()/PyObject_Realloc() now always call malloc()/realloc(), instead
  of calling PyObject_Malloc()/PyObject_Realloc() in debug mode.
* PyObject_Malloc()/PyObject_Realloc() now falls back to
  PyMem_Malloc()/PyMem_Realloc() for allocations larger than 512 bytes.
* Redesign debug checks on memory block allocators as hooks, instead of using C
  macros

to be consistent with practices in other modules.

Hoist conditional expression out of the loop.
Use rightblock as the guard instead of checking for NULL.

importlib._bootstrap._get_sourcefile().

Thanks to its only use by the C API, it was never properly tested
until now.

Thanks to Neal Norwitz for discovering the bug and Madison May for the patch.

The private attribute was leaking out of importlib and led to at least
one person noticing it. Switch to another hack which won't leak
outside of importlib and is nearly as robust.

(3.3->default) Issue #12990: The "Python Launcher" on OSX could not launch python scripts that have paths that include wide characters.

Issue #12990: The "Python Launcher" on OSX could not launch python scripts that have paths that include wide characters.

(3.3->default) Issue #17860: explicitly mention that std* streams are opened in binary mode by default.

The documentation does mention that the streams are opened in text mode
when univeral_newlines is true, but not that that they are opened in
binary mode when that argument is false and that seems to confuse at
least some users.

The documentation does mention that the streams are opened in text mode
when univeral_newlines is true, but not that that they are opened in
binary mode when that argument is false and that seems to confuse at
least some users.

The division and modulo calculation in deque_item() can be compiled
to fast bitwise operations when the BLOCKLEN is a power of two.

Timing before:

 ~/cpython $ py -m timeit -r7 -s 'from collections import deque' -s 'd=deque(range(10))' 'd[5]'
10000000 loops, best of 7: 0.0627 usec per loop

Timing after:

~/cpython $ py -m timeit -r7 -s 'from collections import deque' -s 'd=deque(range(10))' 'd[5]'
10000000 loops, best of 7: 0.0581 usec per loop

ModuleNotFoundError.