A TypeError is now raised instead of an AttributeError in
"with" and "async with" statements for objects which do not
support the context manager or asynchronous context manager
protocols correspondingly.
The hard part was making all the tests pass; there are some subtle issues here, because apparently the future import wasn't tested very thoroughly in previous Python versions.
For example, `inspect.signature()` returned type objects normally (except for forward references), but strings with the future import. We changed it to try and return type objects by calling `typing.get_type_hints()`, but fall back on returning strings if that function fails (which it may do if there are future references in the annotations that require passing in a specific namespace to resolve).
* Reorder the __aenter__ and __aexit__ checks for async with
* Add assertions for async with body being skipped
* Swap __aexit__ and __aenter__ loading in the documentation
Modify test_coroutines, test_cprofile, test_generators, test_raise,
test_ssl and test_yield_from to use
support.catch_unraisable_exception() rather than
support.captured_stderr().
test_thread: remove test_save_exception_state_on_error() which is now
updated. test_unraisable_exception() checks that sys.unraisablehook()
is called to handle _thread.start_new_thread() exception.
test_cprofile now rely on unittest for test discovery: replace
support.run_unittest() with unittest.main().
It has been documented as deprecated and to be removed in 3.8;
From a comment on another thread – which I can't find ; leave get_coro_wrapper() for now, but always return `None`.
https://bugs.python.org/issue36933
* Copy test_exceptions.test_unraisable() to
test_sys.UnraisableHookTest().
* Use catch_unraisable_exception() in test_coroutines,
test_exceptions, test_generators.
* Added new opcode END_ASYNC_FOR.
* Setting global StopAsyncIteration no longer breaks "async for" loops.
* Jumping into an "async for" loop is now disabled.
* Jumping out of an "async for" loop no longer corrupts the stack.
* Simplify the compiler.
The commit removes one unnecessary "if" clause in genobject.c. That "if" clause was masking un-awaited coroutines warnings just to make writing unittests more convenient.
When an unawaited coroutine is collected very late in shutdown --
like, during the final GC at the end of PyImport_Cleanup -- then it
was triggering an interpreter abort, because we'd try to look up the
"warnings" module and not only was it missing (we were prepared for
that), but the entire module system was missing (which we were not
prepared for).
I've tried to fix this at the source, by making the utility function
get_warnings_attr robust against this in general. Note that it already
has the convention that it can return NULL without setting an error,
which is how it signals that the attribute it was asked to fetch is
missing, and that all callers already check for NULL returns.
There's a similar check for being late in shutdown at the top of
warn_explicit, which might be unnecessary after this fix, but I'm not
sure so I'm going to leave it.
* Add coro.cr_origin and sys.set_coroutine_origin_tracking_depth
* Use coroutine origin information in the unawaited coroutine warning
* Stop using set_coroutine_wrapper in asyncio debug mode
* In BaseEventLoop.set_debug, enable debugging in the correct thread
