gh-149459: Fix segfault when _LOAD_SPECIAL guard deoptimizes#149478
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cocolato wants to merge 4 commits intopython:mainfrom
Open
gh-149459: Fix segfault when _LOAD_SPECIAL guard deoptimizes#149478cocolato wants to merge 4 commits intopython:mainfrom
cocolato wants to merge 4 commits intopython:mainfrom
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cocolato
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markshannon,
savannahostrowski and
tomasr8
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LOAD_SPECIALexpands as:_RECORD_TOS_TYPE + _INSERT_NULL + _LOAD_SPECIAL_INSERT_NULLalters the actual stack structure:Before modification:
[..., self]After modification:
[..., NULL, self]The optimizer has introduced
_GUARD_TYPE_VERSION. If a guard is placed after_INSERT_NULL, and the guard fails resulting in a side exit, the interpreter will deopt back to the originalLOAD_SPECIAL. However, by this point, the stack has already been modified by_INSERT_NULLto[..., NULL, self]._PyObject_LookupSpecialMethod#149459