Confirmed with @jaraco that this indeed needs a fix.
A question that came up while I was digging into the code: I think `SelectableGroups` could similarly use `__slots__ = ()`, since its purpose seems only for convenience around `dict`, not to have attributes of its own.
Automerge-Triggered-By: GH:jaraco
* 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
* bpo-44893: Implement EntryPoint as simple class and deprecate tuple access in favor of attribute access. Syncs with importlib_metadata 4.8.1.
* Apply refactorings found in importlib_metadata 4.8.2.
* bpo-45514: Apply changes from importlib_resources@a3ef4128c6
* Mark legacy functions as deprecated in the docs and link to the migration docs in importlib_resources docs.
* Apply changes from importlib_resources@329ae9d5f2c.
* Indicate importlib.resources as a module.
Co-authored-by: Filipe Laíns <lains@riseup.net>
* Make internal APIs that take PyFrameConstructor take a PyFunctionObject instead.
* Add reference to function to frame, borrow references to builtins and globals.
* Add COPY_FREE_VARS instruction to allow specialization of calls to inner functions.
Rename namespace package __loader__ class to be public.
Make the old name, i.e. _NamespaceLoader, an alias for the public name, for backward compatibility.
Currently frozen modules do not have __file__ set. In their spec, origin is set to "frozen" and they are marked as not having a location. (Similarly, for frozen packages __path__ is set to an empty list.) However, for frozen stdlib modules we are able to extrapolate __file__ as long as we can determine the stdlib directory at runtime. (We now do so since gh-28586.) Having __file__ set is helpful for a number of reasons. Likewise, having a non-empty __path__ means we can import submodules of a frozen package from the filesystem (e.g. we could partially freeze the encodings module).
This change sets __file__ (and adds to __path__) for frozen stdlib modules. It uses sys._stdlibdir (from gh-28586) and the frozen module alias information (from gh-28655). All that work is done in FrozenImporter (in Lib/importlib/_bootstrap.py).
Also, if a frozen module is imported before importlib is bootstrapped (during interpreter initialization) then we fix up that module and its spec during the importlib bootstrapping step (i.e. imporlib._bootstrap._setup()) to match what gets set by FrozenImporter, including setting the file info (if the stdlib dir is known). To facilitate this, modules imported using PyImport_ImportFrozenModule() have __origname__ set using the frozen module alias info. __origname__ is popped off during importlib bootstrap.
(To be clear, even with this change the new code to set __file__ during fixups in imporlib._bootstrap._setup() doesn't actually get triggered yet. This is because sys._stdlibdir hasn't been set yet in interpreter initialization at the point importlib is bootstrapped. However, we do fix up such modules at that point to otherwise match the result of importing through FrozenImporter, just not the __file__ and __path__ parts. Doing so will require changes in the order in which things happen during interpreter initialization. That can be addressed separately. Once it is, the file-related fixup code from this PR will kick in.)
Here are things this change does not do:
* set __file__ for non-stdlib modules (no way of knowing the parent dir)
* set __file__ if the stdlib dir is not known (nor assume the expense of finding it)
* relatedly, set __file__ if the stdlib is in a zip file
* verify that the filename set to __file__ actually exists (too expensive)
* update __path__ for frozen packages that alias a non-package (since there is no package dir)
Other things this change skips, but we may do later:
* set __file__ on modules imported using PyImport_ImportFrozenModule()
* set co_filename when we unmarshal the frozen code object while importing the module (e.g. in FrozenImporter.exec_module()) -- this would allow tracebacks to show source lines
* implement FrozenImporter.get_filename() and FrozenImporter.get_source()
https://bugs.python.org/issue21736
In the list of generated frozen modules at the top of Tools/scripts/freeze_modules.py, you will find that some of the modules have a different name than the module (or .py file) that is actually frozen. Let's call each case an "alias". Aliases do not come into play until we get to the (generated) list of modules in Python/frozen.c. (The tool for freezing modules, Programs/_freeze_module, is only concerned with the source file, not the module it will be used for.)
Knowledge of which frozen modules are aliases (and the identity of the original module) normally isn't important. However, this information is valuable when we go to set __file__ on frozen stdlib modules. This change updates Tools/scripts/freeze_modules.py to map aliases to the original module name (or None if not a stdlib module) in Python/frozen.c. We also add a helper function in Python/import.c to look up a frozen module's alias and add the result of that function to the frozen info returned from find_frozen().
https://bugs.python.org/issue45020
Before this change we end up duplicating effort and throwing away data in FrozenImporter.find_spec(). Now we do the work once in find_spec() and the only thing we do in FrozenImporter.exec_module() is turn the raw frozen data into a code object and then exec it.
We've added _imp.find_frozen(), add an arg to _imp.get_frozen_object(), and updated FrozenImporter. We've also moved some code around to reduce duplication, get a little more consistency in outcomes, and be more efficient.
Note that this change is mostly necessary if we want to set __file__ on frozen stdlib modules. (See https://bugs.python.org/issue21736.)
https://bugs.python.org/issue45324
Implements a two steps check in `importlib._bootstrap._find_and_load()` to avoid locking when the module has been already imported and it's ready.
---
Using `importlib.__import__()`, after this, does show a big difference:
Before:
```
$ ./python -c 'import timeit; print(timeit.timeit("__import__(\"timeit\")", setup="from importlib import __import__"))'
15.92248619502061
```
After:
```
$ ./python -c 'import timeit; print(timeit.timeit("__import__(\"timeit\")", setup="from importlib import __import__"))'
1.206068897008663
```
---
This PR is part of PEP 657 and augments the compiler to emit ending
line numbers as well as starting and ending columns from the AST
into compiled code objects. This allows bytecodes to be correlated
to the exact source code ranges that generated them.
This information is made available through the following public APIs:
* The `co_positions` method on code objects.
* The C API function `PyCode_Addr2Location`.
Co-authored-by: Batuhan Taskaya <isidentical@gmail.com>
Co-authored-by: Ammar Askar <ammar@ammaraskar.com>
Currently, if an arg value escapes (into the closure for an inner function) we end up allocating two indices in the fast locals even though only one gets used. Additionally, using the lower index would be better in some cases, such as with no-arg `super()`. To address this, we update the compiler to fix the offsets so each variable only gets one "fast local". As a consequence, now some cell offsets are interspersed with the locals (only when an arg escapes to an inner function).
https://bugs.python.org/issue43693
This was reverted in GH-26596 (commit 6d518bb) due to some bad memory accesses.
* Add the MAKE_CELL opcode. (gh-26396)
The memory accesses have been fixed.
https://bugs.python.org/issue43693
This moves logic out of the frame initialization code and into the compiler and eval loop. Doing so simplifies the runtime code and allows us to optimize it better.
https://bugs.python.org/issue43693
These were reverted in gh-26530 (commit 17c4edc) due to refleaks.
* 2c1e258 - Compute deref offsets in compiler (gh-25152)
* b2bf2bc - Add new internal code objects fields: co_fastlocalnames and co_fastlocalkinds. (gh-26388)
This change fixes the refleaks.
https://bugs.python.org/issue43693
* Revert "bpo-43693: Compute deref offsets in compiler (gh-25152)"
This reverts commit b2bf2bc1ec.
* Revert "bpo-43693: Add new internal code objects fields: co_fastlocalnames and co_fastlocalkinds. (gh-26388)"
This reverts commit 2c1e2583fd.
These two commits are breaking the refleak buildbots.
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>
Remove two unused imports: _thread and _weakref. Avoid creating a new
winreg builtin module if it's already available in sys.modules.
The winreg module is now stored as "winreg" rather than "_winreg".
* Hard reset + cherry piciking the changes.
* 📜🤖 Added by blurb_it.
* Added @vstinner News
* Update Misc/NEWS.d/next/Library/2020-02-11-13-01-38.bpo-38691.oND8Sk.rst
Co-Authored-By: Victor Stinner <vstinner@python.org>
* Hard reset to master
* Hard reset to master + latest changes
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
* Improve zipfile.Path performance on zipfiles with a large number of entries.
* 📜🤖 Added by blurb_it.
* Add bpo to blurb
* Sync with importlib_metadata 1.5 (6fe70ca)
* Update blurb.
* Remove compatibility code
* Add stubs module, omitted from earlier commit
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
* Add DICT_UPDATE and DICT_MERGE bytecodes. Use them for ** unpacking.
* Remove BUILD_MAP_UNPACK and BUILD_MAP_UNPACK_WITH_CALL, as they are now unused.
* Update magic number for ** unpacking opcodes.
* Update dis.rst to incorporate new bytecodes.
* Add blurb entry.
* Add three new bytecodes: LIST_TO_TUPLE, LIST_EXTEND, SET_UPDATE. Use them to implement star unpacking expressions.
* Remove four bytecodes BUILD_LIST_UNPACK, BUILD_TUPLE_UNPACK, BUILD_SET_UNPACK and BUILD_TUPLE_UNPACK_WITH_CALL opcodes as they are now unused.
* Update magic number and dis.rst for new bytecodes.
* bpo-39336: Allow setattr to fail on modules which aren't assignable
When attaching a child module to a package if the object in sys.modules raises an AttributeError (e.g. because it is immutable) it causes the whole import to fail. This now allows immutable packages to exist and an ImportWarning is reported and the AttributeError exception is ignored.
Break up COMPARE_OP into four logically distinct opcodes:
* COMPARE_OP for rich comparisons
* IS_OP for 'is' and 'is not' tests
* CONTAINS_OP for 'in' and 'is not' tests
* JUMP_IF_NOT_EXC_MATCH for checking exceptions in 'try-except' statements.
* bpo-39022, bpo-38594: Sync with importlib_metadata 1.3 including improved docs for custom finders and better serialization support in EntryPoints.
* 📜🤖 Added by blurb_it.
* Correct module reference
Remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY and POP_FINALLY bytecodes. Implement finally blocks by code duplication.
Reimplement frame.lineno setter using line numbers rather than bytecode offsets.
Capturing exceptions into names can lead to reference cycles though the __traceback__ attribute of the exceptions in some obscure cases that have been reported previously and fixed individually. As these variables are not used anyway, we can remove the binding to reduce the chances of creating reference cycles.
See for example GH-13135
Imports now raise `TypeError` instead of `ValueError` for relative import failures. This makes things consistent between `builtins.__import__` and `importlib.__import__` as well as using a more natural import for the failure.
https://bugs.python.org/issue37444
Automerge-Triggered-By: @brettcannon
This commit contains the implementation of PEP570: Python positional-only parameters.
* Update Grammar/Grammar with new typedarglist and varargslist
* Regenerate grammar files
* Update and regenerate AST related files
* Update code object
* Update marshal.c
* Update compiler and symtable
* Regenerate importlib files
* Update callable objects
* Implement positional-only args logic in ceval.c
* Regenerate frozen data
* Update standard library to account for positional-only args
* Add test file for positional-only args
* Update other test files to account for positional-only args
* Add News entry
* Update inspect module and related tests
* bpo-35321: Set the spec origin to frozen in frozen modules
This fix correctly sets the spec origin to
"frozen" for the _frozen_importlib module. Note that the
origin was already correctly set in _frozen_importlib_external.
* 📜🤖 Added by blurb_it.
Two kind of mistakes:
1. Missed space. After concatenating there is no space between words.
2. Missed comma. Causes unintentional concatenating in a list of strings.
Modules imported last are now cleared first at interpreter shutdown.
A newly imported module is moved to the end of sys.modules, behind
modules on which it depends.
Since `SourceFileLoader.set_data()` catches exceptions raised by `_write_atomic()` and logs an informative message consequently, always logging successful outcome in 'SourceLoader.get_code()' seems redundant.
https://bugs.python.org/issue35024