pytorch

b57cc9c7 - Reland "[pytorch][PR] Support dataclasses in TorchScript" (#74353)

Reland "[pytorch][PR] Support dataclasses in TorchScript" (#74353) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/74353 Repatched `d00de0d43598522b8f6ab2de553b6aaf6768faa5` by Nora Belrose (norabelrose). With following changes: * Register fake source of generated methods in linecache so that inspect.get_source will succeed. * this patching is only triggered if the given dataclass passed to torch.jit.script previously. Effectively we make this feature opt-in. ## Original Summary: Fixes #72901. Since we can't get access to the source code for synthesized magic methods on dataclasses, we have to synthesize our own versions. torch/jit/_dataclass_impls.py has the code that does this. What's supported Synthesized __init__, __eq__, and the comparison magic methods when order=True is set on the dataclass decorator Default values for fields __post_init__, including using InitVar fields inside of __post_init__, on Python 3.8+ Overriding __eq__ or any of the comparison magic methods to provide your own implementation What's not supported Default factory initializers for fields Frozen dataclasses InitVar on Python 3.7 __repr__ and __hash__ (these are actually implemented, but the TorchScript interpreter won't call them) Using the != operator on dataclasses inside TorchScript; this is because TorchScript requires that you implement __ne__ to use this operator, whereas in regular Python the != operator will resolve to the negation of whatever is returned by __eq__ if there's no __ne__. Dataclasses don't actually synthesize an __ne__ method for this reason. I've been toying with different ways to fix this but != is not working in this PR at the moment. Test Plan: unittest Also run previously failed test: ``` buck test mode/dev-nosan //fblearner/flow/projects/fluent2/definition/transformers/contrib/faim/test:tests -- --exact 'fblearner/flow/projects/fluent2/definition/transformers/contrib/faim/test:tests - test_mixmatch_multiclass (fblearner.flow.projects.fluent2.definition.transformers.contrib.faim.test.faim_mixmatch_test.TestFaimTransformerMixMatch)' ``` passes Reviewed By: zhxchen17 Differential Revision: D34808842 fbshipit-source-id: 02f807cff1ea99e606333960225c71a239743a4b (cherry picked from commit ec885a2bc04f9e5f65838fa5704d9a05815ebd37)