46 lines
1.3 KiB
Python
46 lines
1.3 KiB
Python
import sys
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import warnings
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from ._utils import get_linter_option
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__all__ = ["UnusedMustUse", "MustUse"]
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class UnusedMustUse(Warning):
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pass
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class MustUse:
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_MustUse__silence = False
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_MustUse__warning = UnusedMustUse
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def __new__(cls, *args, src_loc_at=0, **kwargs):
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frame = sys._getframe(1 + src_loc_at)
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self = super().__new__(cls)
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self._MustUse__used = False
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self._MustUse__context = dict(
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filename=frame.f_code.co_filename,
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lineno=frame.f_lineno,
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source=self)
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return self
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def __del__(self):
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if self._MustUse__silence:
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return
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if hasattr(self, "_MustUse__used") and not self._MustUse__used:
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if get_linter_option(self._MustUse__context["filename"],
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self._MustUse__warning.__name__, bool, True):
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warnings.warn_explicit(
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"{!r} created but never used".format(self), self._MustUse__warning,
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**self._MustUse__context)
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_old_excepthook = sys.excepthook
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def _silence_elaboratable(type, value, traceback):
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# Don't show anything if the interpreter crashed; that'd just obscure the exception
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# traceback instead of helping.
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MustUse._MustUse__silence = True
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_old_excepthook(type, value, traceback)
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sys.excepthook = _silence_elaboratable
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