It no longer depends on the order of arguments.
hash(int | str) == hash(str | int)
Co-authored-by: Jack DeVries <58614260+jdevries3133@users.noreply.github.com>
The non-GC-type branch of subtype_dealloc is using the type of an object after freeing in the same unsafe way as GH-26274 fixes. (I believe the old news entry covers this change well enough.)
https://bugs.python.org/issue44184
Patch by Erik Welch.
bpo-19072 (#8405) allows `classmethod` to wrap other descriptors, but this does
not work when the wrapped descriptor mimics classmethod. The current PR fixes
this.
In Python 3.8 and before, one could create a callable descriptor such that this
works as expected (see Lib/test/test_decorators.py for examples):
```python
class A:
@myclassmethod
def f1(cls):
return cls
@classmethod
@myclassmethod
def f2(cls):
return cls
```
In Python 3.8 and before, `A.f2()` return `A`. Currently in Python 3.9, it
returns `type(A)`. This PR make `A.f2()` return `A` again.
As of #8405, classmethod calls `obj.__get__(type)` if `obj` has `__get__`.
This allows one to chain `@classmethod` and `@property` together. When
using classmethod-like descriptors, it's the second argument to `__get__`--the
owner or the type--that is important, but this argument is currently missing.
Since it is None, the "owner" argument is assumed to be the type of the first
argument, which, in this case, is wrong (we want `A`, not `type(A)`).
This PR updates classmethod to call `obj.__get__(type, type)` if `obj` has
`__get__`.
Co-authored-by: Erik Welch <erik.n.welch@gmail.com>
* Fix issubclass() for None.
E.g. issubclass(type(None), int | None) returns now True.
* Fix issubclass() for virtual subclasses.
E.g. issubclass(dict, int | collections.abc.Mapping) returns now True.
* Fix crash in isinstance() if the check for one of items raises exception.
Heap types with the Py_TPFLAGS_IMMUTABLETYPE flag can now inherit the
PEP 590 vectorcall protocol. Previously, this was only possible for static types.
Co-authored-by: Victor Stinner <vstinner@python.org>
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>
_PyObject_GetMethod() now uses _PyType_IsReady() to decide if
PyType_Ready() must be called or not, rather than testing if
tp->tp_dict is NULL.
Move also variable declarations closer to where they are used, and
use Py_NewRef().
Add an internal _PyType_AllocNoTrack() function to allocate an object
without tracking it in the GC.
Modify dict_new() to use _PyType_AllocNoTrack(): dict subclasses are
now only tracked once all PyDictObject members are initialized.
Calling _PyObject_GC_UNTRACK() is no longer needed for the dict type.
Similar change in tuple_subtype_new() for tuple subclasses.
Replace tuple_gc_track() with _PyObject_GC_TRACK().
Remove 4 C API private trashcan functions which were only kept for
the backward compatibility of the stable ABI with Python 3.8 and
older, since the trashcan API was not usable with the limited C API
on Python 3.8 and older. The trashcan API was excluded from the
limited C API in Python 3.9.
Removed functions:
* _PyTrash_deposit_object()
* _PyTrash_destroy_chain()
* _PyTrash_thread_deposit_object()
* _PyTrash_thread_destroy_chain()
The trashcan C API was never usable with the limited C API, since old
trashcan macros accessed directly PyThreadState members like
"_tstate->trash_delete_nesting", whereas the PyThreadState structure
is opaque in the limited C API.
Exclude also the PyTrash_UNWIND_LEVEL constant from the C API.
The trashcan C API was modified in Python 3.9 by commit
38965ec541 and in Python 3.10 by commit
ed1a5a5bac to hide implementation
details.
PyModuleDef_Init() no longer tries to make PyModule_Type type: it's
already done by _PyTypes_Init() at Python startup. Replace
PyType_Ready() call with an assertion.
1. Remove conditions already checked by assert()
2. Remove object_init() call that effectively creates an empty tuple and
checks that this tuple is empty
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
* Specialize LOAD_ATTR with LOAD_ATTR_SLOT and LOAD_ATTR_SPLIT_KEYS
* Move dict-common.h to internal/pycore_dict.h
* Add LOAD_ATTR_WITH_HINT specialized opcode.
* Quicken in function if loopy
* Specialize LOAD_ATTR for module attributes.
* Add specialization stats
This is the same fix as for PyFrame_LocalsToFast() in gh-26609, but applied to PyFrame_FastToLocalsWithError(). (It should have been in that PR.)
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
* Add co_firstinstr field to code object.
* Implement barebones quickening.
* Use non-quickened bytecode when tracing.
* Add NEWS item
* Add new file to Windows build.
* Don't specialize instructions with EXTENDED_ARG.
* 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
The PyType_Ready() function now raises an error if a type is defined
with the Py_TPFLAGS_HAVE_GC flag set but has no traverse function
(PyTypeObject.tp_traverse).
* Move up the comment about fields using in hashing/comparision.
* Group the fields more clearly.
* Add co_ncellvars and co_nfreevars.
* Raise ValueError if nlocals != len(varnames), rather than aborting.
Fix a regression in type() when a metaclass raises an exception. The
C function type_new() must properly report the exception when a
metaclass constructor raises an exception and the winner class is not
the metaclass.
Fix a crash at Python exit when a deallocator function removes the
last strong reference to a heap type.
Don't read type memory after calling basedealloc() since
basedealloc() can deallocate the type and free its memory.
_PyMem_IsPtrFreed() argument is now constant.
* Remove 'zombie' frames. We won't need them once we are allocating fixed-size frames.
* Add co_nlocalplus field to code object to avoid recomputing size of locals + frees + cells.
* Move locals, cells and freevars out of frame object into separate memory buffer.
* Use per-threadstate allocated memory chunks for local variables.
* Move globals and builtins from frame object to per-thread stack.
* Move (slow) locals frame object to per-thread stack.
* Move internal frame functions to internal header.
These are passed and called as PyCFunction, however they are defined here without the (ignored) args parameter.
This works fine in some C compilers, but fails in webassembly or anything else that has strict function pointer call type checking.
"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%.
check_set_special_type_attr() and type_set_annotations()
now check for immutable flag (Py_TPFLAGS_IMMUTABLETYPE).
Co-authored-by: Victor Stinner <vstinner@python.org>
The PyStdPrinter_Type type now uses the
Py_TPFLAGS_DISALLOW_INSTANTIATION flag to disallow instantiation,
rather than seting a tp_init method which always fail.
Write also unit tests for PyStdPrinter_Type.
Add a new Py_TPFLAGS_DISALLOW_INSTANTIATION type flag to disallow
creating type instances: set tp_new to NULL and don't create the
"__new__" key in the type dictionary.
The flag is set automatically on static types if tp_base is NULL or
&PyBaseObject_Type and tp_new is NULL.
Use the flag on the following types:
* _curses.ncurses_version type
* _curses_panel.panel
* _tkinter.Tcl_Obj
* _tkinter.tkapp
* _tkinter.tktimertoken
* _xxsubinterpretersmodule.ChannelID
* sys.flags type
* sys.getwindowsversion() type
* sys.version_info type
Update MyStr example in the C API documentation to use
Py_TPFLAGS_DISALLOW_INSTANTIATION.
Add _PyStructSequence_InitType() function to create a structseq type
with the Py_TPFLAGS_DISALLOW_INSTANTIATION flag set.
type_new() calls _PyType_CheckConsistency() at exit.
* Add Py_TPFLAGS_SEQUENCE and Py_TPFLAGS_MAPPING, add to all relevant standard builtin classes.
* Set relevant flags on collections.abc.Sequence and Mapping.
* Use flags in MATCH_SEQUENCE and MATCH_MAPPING opcodes.
* Inherit Py_TPFLAGS_SEQUENCE and Py_TPFLAGS_MAPPING.
* Add NEWS
* Remove interpreter-state map_abc and seq_abc fields.
While working on another issue, I noticed two minor nits in the C implementation of the module object. Both are related to getting a module's name.
First, the C function module_dir() (module.__dir__) starts by ensuring the module dict is valid. If the module dict is invalid, it wants to format an exception using the name of the module, which it gets from PyModule_GetName(). However, PyModule_GetName() gets the name of the module from the dict. So getting the name in this circumstance will never succeed.
When module_dir() wants to format the error but can't get the name, it knows that PyModule_GetName() must have already raised an exception. So it leaves that exception alone and returns an error. The end result is that the exception raised here is kind of useless and misleading: dir(module) on a module with no __dict__ raises SystemError("nameless module"). I changed the code to actually raise the exception it wanted to raise, just without a real module name: TypeError("<module>.__dict__ is not a dictionary"). This seems more useful, and would do a better job putting the programmer who encountered this on the right track of figuring out what was going on.
Second, the C API function PyModule_GetNameObject() checks to see if the module has a dict. If m->md_dict is not NULL, it calls _PyDict_GetItemIdWithError(). However, it's possible for m->md_dict to be None. And if you call _PyDict_GetItemIdWithError(Py_None, ...) it will *crash*.
Unfortunately, this crash was due to my own bug in the other branch. Fixing my code made the crash go away. I assert that this is still possible at the API level.
The fix is easy: add a PyDict_Check() to PyModule_GetNameObject().
Unfortunately, I don't know how to add a unit test for this. Having changed module_dir() above, I can't find any other interfaces callable from Python that eventually call PyModule_GetNameObject(). So I don't know how to trick the runtime into reproducing this error.
Since both these changes are minor--each entails only a small edit to only one line--I didn't bother with a news item.
Change class and module objects to lazy-create empty annotations dicts on demand. The annotations dicts are stored in the object's `__dict__` for backwards compatibility.
Accessing the following attributes will now fire PEP 578 style audit hooks as ("object.__getattr__", obj, name):
* PyTracebackObject: tb_frame
* PyFrameObject: f_code
* PyGenObject: gi_code, gi_frame
* PyCoroObject: cr_code, cr_frame
* PyAsyncGenObject: ag_code, ag_frame
Add an AUDIT_READ attribute flag aliased to READ_RESTRICTED.
Update obsolete flag documentation.
* 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.
Introduce Py_TPFLAGS_IMMUTABLETYPE flag for immutable type objects, and
modify PyType_Ready() to set it for static types.
Co-authored-by: Victor Stinner <vstinner@python.org>
To improve the user experience understanding what part of the error messages associated with SyntaxErrors is wrong, we can highlight the whole error range and not only place the caret at the first character. In this way:
>>> foo(x, z for z in range(10), t, w)
File "<stdin>", line 1
foo(x, z for z in range(10), t, w)
^
SyntaxError: Generator expression must be parenthesized
becomes
>>> foo(x, z for z in range(10), t, w)
File "<stdin>", line 1
foo(x, z for z in range(10), t, w)
^^^^^^^^^^^^^^^^^^^^
SyntaxError: Generator expression must be parenthesized
Add pycore_moduleobject.h internal header file with static inline
functions to access module members:
* _PyModule_GetDict()
* _PyModule_GetDef()
* _PyModule_GetState()
These functions don't check at runtime if their argument has a valid
type and can be inlined even if Python is not built with LTO.
_PyType_GetModuleByDef() uses _PyModule_GetDef().
Replace PyModule_GetState() with _PyModule_GetState() in the
extension modules, considered as performance sensitive:
* _abc
* _functools
* _operator
* _pickle
* _queue
* _random
* _sre
* _struct
* _thread
* _winapi
* array
* posix
The following extensions are now built with the Py_BUILD_CORE_MODULE
macro defined, to be able to use the internal pycore_moduleobject.h
header: _abc, array, _operator, _queue, _sre, _struct.
PyType_Ready() now ensures that a type MRO cannot be empty.
_PyType_GetModuleByDef() no longer checks "i < PyTuple_GET_SIZE(mro)"
at the first loop iteration to optimize the most common case, when
the argument is the defining class.
_PyType_GetModuleByDef() no longer checks if types are heap types.
_PyType_GetModuleByDef() must only be called on a heap type created
by PyType_FromModuleAndSpec() or on its subclasses.
type_ready_mro() ensures that a static type cannot inherit from a
heap type.
When printing NameError raised by the interpreter, PyErr_Display
will offer suggestions of simmilar variable names in the function that the exception
was raised from:
>>> schwarzschild_black_hole = None
>>> schwarschild_black_hole
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name 'schwarschild_black_hole' is not defined. Did you mean: schwarzschild_black_hole?
When printing AttributeError, PyErr_Display will offer suggestions of similar
attribute names in the object that the exception was raised from:
>>> collections.namedtoplo
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: module 'collections' has no attribute 'namedtoplo'. Did you mean: namedtuple?
* Rename functions
* Only pass type parameter to "add_xxx" functions.
* Clarify the role of the type_ready_inherit_as_structs() function.
* Move type_dict_set_doc() code to call it in type_ready_fill_dict().
* Split PyType_Ready() into sub-functions.
* type_ready_mro() now checks if bases are static types earlier.
* Check tp_name earlier, in type_ready_checks().
* Add _PyType_IsReady() macro to check if a type is ready.
Add the Py_Is(x, y) function to test if the 'x' object is the 'y'
object, the same as "x is y" in Python. Add also the Py_IsNone(),
Py_IsTrue(), Py_IsFalse() functions to test if an object is,
respectively, the None singleton, the True singleton or the False
singleton.
* Split type_new() into into many small functions.
* Add type_new_ctx structure to pass variables between subfunctions.
* Initialize some PyTypeObject and PyHeapTypeObject members earlier
in type_new_alloc().
* Rename variables to more specific names.
* Add "__weakref__" identifier for type_new_visit_slots().
* Factorize code to convert a method to a classmethod
(__init_subclass__ and __class_getitem__).
* Add braces to respect PEP 7.
* Move variable declarations where the variables are initialized.
Static methods (@staticmethod) and class methods (@classmethod) now
inherit the method attributes (__module__, __name__, __qualname__,
__doc__, __annotations__) and have a new __wrapped__ attribute.
Changes:
* Add a repr() method to staticmethod and classmethod types.
* Add tests on the @classmethod decorator.
Serhiy Storchaka
T. Wouters
Łukasz Langa
Mark Shannon
Erlend Egeberg Aasland
Ammar Askar
Gabriele N. Tornetta
Yurii Karabas
Pablo Galindo
Batuhan Taskaya
Ken Jin
Victor Stinner
Miguel Brito
Guido van Rossum
Sergey Fedoseev
Eric Snow
Mark Dickinson
Tim Peters
E-Paine
Inada Naoki
Joe Marshall
Jakub Kulík
larryhastings
Steve Dower
Ryan Hileman
Hristo Venev
Raymond Hettinger
Dennis Sweeney