Class Unreachable

mypyc/ir/ops.py:524–552

Mark the end of basic block as unreachable. This is sometimes necessary when the end of a basic block is never reached. This can also be explicitly added to the end of non-None returning functions (in None-returning function we can just return None). Mypy statically guarantees

@final
class Unreachable(ControlOp):
    """Mark the end of basic block as unreachable.

    This is sometimes necessary when the end of a basic block is never
    reached. This can also be explicitly added to the end of non-None
    returning functions (in None-returning function we can just return
    None).

    Mypy statically guarantees that the end of the function is not
    unreachable if there is not a return statement.

    This prevents the block formatter from being confused due to lack
    of a leave and also leaves a nifty note in the IR. It is not
    generally processed by visitors.
    """

    error_kind = ERR_NEVER

    def __init__(self, line: int = -1) -> None:
        super().__init__(line)

    def sources(self) -> list[Value]:
        return []

    def set_sources(self, new: list[Value]) -> None:
        assert not new

    def accept(self, visitor: OpVisitor[T]) -> T:
        return visitor.visit_unreachable(self)


class RegisterOp(Op):