Merges locals and cells into a single array.
Saves a pointer in the interpreter and means that we don't need the LOAD_CLOSURE opcode any more
https://bugs.python.org/issue43693
A number of places in the code base (notably ceval.c and frameobject.c) rely on mapping variable names to indices in the frame "locals plus" array (AKA fast locals), and thus opargs. Currently the compiler indirectly encodes that information on the code object as the tuples co_varnames, co_cellvars, and co_freevars. At runtime the dependent code must calculate the proper mapping from those, which isn't ideal and impacts performance-sensitive sections. This is something we can easily address in the compiler instead.
This change addresses the situation by replacing internal use of co_varnames, etc. with a single combined tuple of names in locals-plus order, along with a minimal array mapping each to its kind (local vs. cell vs. free). These two new PyCodeObject fields, co_fastlocalnames and co_fastllocalkinds, are not exposed to Python code for now, but co_varnames, etc. are still available with the same values as before (though computed lazily).
Aside from the (mild) performance impact, there are a number of other benefits:
* there's now a clear, direct relationship between locals-plus and variables
* code that relies on the locals-plus-to-name mapping is simpler
* marshaled code objects are smaller and serialize/de-serialize faster
Also note that we can take this approach further by expanding the possible values in co_fastlocalkinds to include specific argument types (e.g. positional-only, kwargs). Doing so would allow further speed-ups in _PyEval_MakeFrameVector(), which is where args get unpacked into the locals-plus array. It would also allow us to shrink marshaled code objects even further.
https://bugs.python.org/issue43693
"Zero cost" exception handling.
* Uses a lookup table to determine how to handle exceptions.
* Removes SETUP_FINALLY and POP_TOP block instructions, eliminating (most of) the runtime overhead of try statements.
* Reduces the size of the frame object by about 60%.
* bpo-43926: Cleaner metadata with PEP 566 JSON support.
* Add blurb
* Add versionchanged and versionadded declarations for changes to metadata.
* Use descriptor for PEP 566
* Add length parameter to PyLineTable_InitAddressRange and doen't use sentinel values at end of table. Makes the line number table more robust.
* Update PyCodeAddressRange to match PEP 626.
* Handle check for sending None to starting generator and coroutine into bytecode.
* Document new bytecode and make it fail gracefully if mis-compiled.
* Use instruction offset, rather than bytecode offset. Streamlines interpreter dispatch a bit, and removes most EXTENDED_ARGs for jumps.
* Change some uses of PyCode_Addr2Line to PyFrame_GetLineNumber
* bpo-43428: Sync with importlib_metadata 3.7.3 (16ac3a95)
* Add 'versionadded' for importlib.metadata.packages_distributions
* Add section in what's new for Python 3.10 highlighting most salient changes and relevant backport.
* Unify behavior in ResourceReaderDefaultsTests and align with the behavior found in importlib_resources.
* Equip NamespaceLoader with a NamespaceReader.
* Apply changes from importlib_resources 5.0.4
* bpo-42382: In importlib.metadata, `EntryPoint` objects now expose a `.dist` object referencing the `Distribution` when constructed from a `Distribution`.
Also, sync importlib_metadata 3.3:
- Add support for package discovery under package normalization rules.
- The object returned by `metadata()` now has a formally-defined protocol called `PackageMetadata` with declared support for the `.get_all()` method.
* Add blurb
* Remove latent footnote.
Reduce memory footprint and improve performance of loading modules having many func annotations.
>>> sys.getsizeof({"a":"int","b":"int","return":"int"})
232
>>> sys.getsizeof(("a","int","b","int","return","int"))
88
The tuple is converted into dict on the fly when `func.__annotations__` is accessed first.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Inada Naoki <songofacandy@gmail.com>
Use @staticmethod on methods using @classmethod but don't use their
cls parameter on the following classes:
* BuiltinImporter
* FrozenImporter
* WindowsRegistryFinder
* PathFinder
Leave methods using @_requires_builtin or @_requires_frozen unchanged,
since this decorator requires the wrapped method to have an extra parameter
(cls or self).
Simplify the importlib external bootstrap code:
importlib._bootstrap_external now uses regular imports to import
builtin modules. When it is imported, the builtin __import__()
function is already fully working and so can be used to import
builtin modules like sys.
* bpo-41490: ``path`` method to aggressively close handles
* Add blurb
* In ZipReader.contents, eagerly evaluate the contents to release references to the zipfile.
* Instead use _ensure_sequence to ensure any iterable from a reader is eagerly converted to a list if it's not already a sequence.
* Provide native .files support on SourceFileLoader.
* Add native importlib.resources.files() support to zipimporter. Remove fallback support.
* make regen-all
* 📜🤖 Added by blurb_it.
* Move 'files' into the ResourceReader so it can carry the relevant module name context.
* Create 'importlib.readers' module and add FileReader to it.
* Add zip reader and rely on it for a TraversableResources object on zipimporter.
* Remove TraversableAdapter, no longer needed.
* Update blurb.
* Replace backslashes with forward slashes.
* Incorporate changes from importlib_metadata 2.0, finalizing the interface for extension via get_resource_reader.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
* bpo-39791: Update importlib.resources to support files() API (importlib_resources 1.5).
* 📜🤖 Added by blurb_it.
* Add some documentation about the new objects added.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Mark Shannon