# Copyright (c) 2020, 2023 Rocky Bernstein from decompyle3.scanners.tok import Token def ifstmts_jump_invalid( self, lhs: str, n: int, rule, tree, tokens: list, first: int, last: int ) -> bool: come_froms = tree[-1] # This is complicated, but note that the JUMP_IF instruction comes immediately # *before* _ifstmts_jump so that's what we have to test # the COME_FROM against. This can be complicated by intervening # POP_TOP, and pseudo COME_FROM, ELSE instructions # pop_jump_index = first - 1 while pop_jump_index > 0 and tokens[pop_jump_index] in ( "POP_TOP", "JUMP_FORWARD", "COME_FROM", ): pop_jump_index -= 1 if pop_jump_index == 0: return True jump_token = tokens[pop_jump_index] if jump_token.op not in self.opc.JUMP_OPS: return False # FIXME: something is fishy when and EXTENDED ARG is needed before the # pop_jump_index instruction to get the argument. In this case, the # _ifsmtst_jump can jump to a spot beyond the come_froms. # That is going on in the non-EXTENDED_ARG case is that the POP_JUMP_IF # jumps to a JUMP_(FORWARD) which is changed into an EXTENDED_ARG POP_JUMP_IF # to the jumped forwarded address if jump_token.attr > 256: return False pop_jump_offset = jump_token.off2int(prefer_last=False) if isinstance(come_froms, Token): if jump_token.attr < pop_jump_offset and tree[0] != "pass": # This is a jump backwards to a loop. All bets are off here when there the # unless statement is "pass" which has no instructions associated with it. return False return come_froms.attr is not None and pop_jump_offset > come_froms.attr elif len(come_froms) == 0: return False else: return pop_jump_offset > come_froms[-1].attr