Change FOR_ITER to have the same stack effect regardless of whether it branches or not.
Performance is unchanged as FOR_ITER (and specialized forms jump over the cleanup code).
In `_warnings.c`, in the C equivalent of `warnings.warn_explicit()`, if the module globals are given (and not None), the warning will attempt to get the source line for the issued warning. To do this, it needs the module's loader.
Previously, it would only look up `__loader__` in the module globals. In https://github.com/python/cpython/issues/86298 we want to defer to the `__spec__.loader` if available.
The first step on this journey is to check that `loader == __spec__.loader` and issue another warning if it is not. This commit does that.
Since this is a PoC, only manual testing for now.
```python
# /tmp/foo.py
import warnings
import bar
warnings.warn_explicit(
'warning!',
RuntimeWarning,
'bar.py', 2,
module='bar knee',
module_globals=bar.__dict__,
)
```
```python
# /tmp/bar.py
import sys
import os
import pathlib
# __loader__ = pathlib.Path()
```
Then running this: `./python.exe -Wdefault /tmp/foo.py`
Produces:
```
bar.py:2: RuntimeWarning: warning!
import os
```
Uncomment the `__loader__ = ` line in `bar.py` and try it again:
```
sys:1: ImportWarning: Module bar; __loader__ != __spec__.loader (<_frozen_importlib_external.SourceFileLoader object at 0x109f7dfa0> != PosixPath('.'))
bar.py:2: RuntimeWarning: warning!
import os
```
Automerge-Triggered-By: GH:warsaw
This is a small performance improvement, especially for one or two hot
places such as _handle_fromlist() that are called a lot and the
.format() method was being used just to join two strings with a dot.
Otherwise it is merely a readability improvement.
We keep `_ERR_MSG` and `_ERR_MSG_PREFIX` as those may be used elsewhere for canonical looking error messages.
Support for bytes broke sometime between Python 3.2 and 3.6 and has been broken ever since. Trying to bring back supports is surprisingly difficult in the face of -b and checking for keys in sys.path_importer_cache. Since the support was broken for so long, trying to overcome the difficulty of bringing back the support has been deemed not worth it.
Co-authored-by: Eryk Sun <eryksun@gmail.com>
Co-authored-by: Brett Cannon <brett@python.org>
Fix the importlib.resources.as_file() context manager to remove the
temporary file if destroyed late during Python finalization: keep a
local reference to the os.remove() function. Patch by Victor Stinner.
* Stores all location info in linetable to conform to PEP 626.
* Remove column table from code objects.
* Remove end-line table from code objects.
* Document new location table format
Nikita Sobolev
Irit Katriel
Anh71me
Mark Shannon
Jason R. Coombs
Barry Warsaw
Gregory P. Smith
Brett Cannon
Brandt Bucher
Thomas Grainger
Dennis Sweeney
Ken Jin
Victor Stinner
Christian Heimes
Serhiy Storchaka