specman - Specman e：“keep type .. is a”无法细化字段的类型

Question

我的验证环境中有下一个代码：

// seq_file.e
extend SPECIFIC_TYPE sequence {
    keep type driver is a SPECIFIC_TYPE sequence_driver;
    event some_event is @driver.as_a(SPECIFIC_TYPE sequence_driver).some_event;
};

extend SPECIFIC_TYPE SEQ_NAME sequence {
   body()@driver.clock is only {
      var foo := driver.specific_type_field;
   };
};

请注意，keep type driver is a..由于没有必要在driver' 行开始var foo..

但是，keep type driver is a..不影响some_event，即如果as_a从行中删除强制转换，则会出现编译错误'driver' does not have 'some_event' though its subtype do. use driver.as_a(SPECIFIC_TYPE sequence_driver)。

为什么keep type driver is a..无法投driver下线some_event..？

谢谢您的帮助

Answer 1

您的观察是正确的：字段访问（和方法调用）考虑了类型约束，但不考虑事件采样。这是一个限制，可能会在即将发布的版本中删除。我建议联系 Specman 官方支持以获取有关计划的确切信息。