"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%.
* 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.
* 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
* Mark bytecodes at end of try-except as artificial.
* Make sure that the CFG is consistent throughout optimiization.
* Extend line-number propagation logic so that implicit returns after 'try-except' or 'with' have the correct line numbers.
* Update importlib
* Delete jump instructions that bypass empty blocks
* Add news entry
* Explicitly check for unconditional jump opcodes
Using the is_jump function results in the inclusion of instructions like
returns for which this optimization is not really valid. So, instead
explicitly check that the instruction is an unconditional jump.
* Handle conditional jumps, delete jumps gracefully
* Ensure b_nofallthrough and b_reachable are valid
* Add test for redundant jumps
* Regenerate importlib.h and edit Misc/ACKS
* Fix bad whitespace
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.
This commit changes the parsing of f-string expressions with the new parser. The parser gets pre-fed with the location of the expression itself (not the f-string, which was what we were doing before). This allows us to completely skip the shifting of the AST nodes after the parsing is completed.
* 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.
* 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.
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.
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
The peephole optimizer was not optimizing correctly bytecode after negative deltas were introduced. This is due to the fact that some special values (255) were being searched for in both instruction pointer delta and line number deltas.
Add new sys.unraisablehook() function which can be overridden to
control how "unraisable exceptions" are handled. It is called when an
exception has occurred but there is no way for Python to handle it.
For example, when a destructor raises an exception or during garbage
collection (gc.collect()).
Changes:
* Add an internal UnraisableHookArgs type used to pass arguments to
sys.unraisablehook.
* Add _PyErr_WriteUnraisableDefaultHook().
* The default hook now ignores exception on writing the traceback.
* test_sys now uses unittest.main() to automatically discover tests:
remove test_main().
* Add _PyErr_Init().
* Fix PyErr_WriteUnraisable(): hold a strong reference to sys.stderr
while using it
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.
Ken Jin
Mark Shannon
Inada Naoki
Brett Cannon
Om G
Victor Stinner
Lysandros Nikolaou
Pablo Galindo
Serhiy Storchaka
Armin Rigo
Dino Viehland
Dong-hee Na
Zackery Spytz
Ngalim Siregar
Victor Stinner
Nina Zakharenko