liveness.py 文件源码

def remove_id_assignment(self, JOIN, cfg_node):
        lvars = list()

        if isinstance(cfg_node, BBorBInode):
            lvars.append(cfg_node.left_hand_side)
        else:
            try:
                for expr in cfg_node.ast_node.targets:
                    vv = VarsVisitor()
                    vv.visit(expr)
                    lvars.extend(vv.result)
            except AttributeError:  # If it is AugAssign
                vv = VarsVisitor()
                vv.visit(cfg_node.ast_node.target)
                lvars.extend(vv.result)
        for var in lvars:
            if var in self.lattice.get_elements(JOIN):
                # Remove var from JOIN
                JOIN = JOIN ^ self.lattice.el2bv[var]
        return JOIN