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
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>
* 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
* Add PRECALL_FUNCTION opcode.
* Move 'call shape' varaibles into struct.
* Replace CALL_NO_KW and CALL_KW with KW_NAMES and CALL instructions.
* Specialize for builtin methods taking using the METH_FASTCALL | METH_KEYWORDS protocol.
* Allow kwnames for specialized calls to builtin types.
* Specialize calls to tuple(arg) and str(arg).
* Add RETURN_GENERATOR and JUMP_NO_INTERRUPT opcodes.
* Trim frame and generator by word each.
* Minor refactor of frame.c
* Update test.test_sys to account for smaller frames.
* Treat generator functions as normal functions when evaluating and specializing.
* Do not PUSH/POP traceback or type to the stack as part of exc_info
* Remove exc_traceback and exc_type from _PyErr_StackItem
* Add to what's new, because this change breaks things like Cython