Preserve block unreachablility when checking function definitions with constrained TypeVars #18217
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hauntsaninja
approved these changes
Dec 1, 2024
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According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅ |
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Fixes #18210
When checking function definitions with constrained type variables (i.e. type variables with value restrictions), mypy expands the function definition for each possible type variable value. However, blocks in the expanded function definitions have their
is_unreachablereset toFalse, which leads to spurious errors in blocks that were marked as unreachable during semantic analysis.This PR preserves the value of
is_unreachableon blocks in the expanded function definitions.