Dynamic Cast C++ Fail

我在一个g++编译器（Redhat 5.5 gcc 3.4.6版）上遇到了动态强制转换失败，该编译器在Windows Visual studio 2003、2005和2010编译器上运行良好。为了理解我所看到的情况，我会尽快把问题分解。我们有一个从目录加载大量"插件"并动态加载这些插件（它们是动态链接的库）的过程。该过程应该比较不同的规则和数据类型以返回答案。为了使流程模块化，我们让流程了解"BaseDataType"，但不了解实际的特定类型（因此我们可以保持流程的通用性）。程序的流程是这样的：

我们所有的"SpecifcObject"类型都继承自类似的"BaseDataType"

class SpecificObject : public virtual BaseDataType {
   ... Class Items ...
}

这是来自过程的代码看起来像：

// Receive raw data 
void receive_data(void *buff, int size,DataTypeEnum type)
{
   // Get the plugin associated with this data
   ProcessPlugin *plugin = m_plugins[type];
   // Since we need to cast the data properly into its actual type and not its
   // base data type we need the plugin to cast it for us (so we can keep the 
   // process generic)
   BaseDataType *data = plugin->getDataObject(buff);
   if(data)
   {
     // Cast worked just fine 
     .... Other things happen (but object isn't modified) ....
     // Now compare our rule
     RuleObject obj = getRule();
     ResultObject *result = plugin->CompareData(obj,data);
     if(result)
        ... Success Case ...
     else
        ... Error Case ...
   } 
}

现在，这就是（一般）插件的样子

BaseDataType* ProcessPluginOne::getDataObject(unsigned char *buff)
{
    // SpecificObject inherits from BaseDataType using a "virtual" inheritance
    SpecificObject *obj = reinterpret_cast<SpecificObject*>(buff);
    if(obj)
       return (BaseDataType*)obj;
    else
       return NULL;
}
ResultObject* ProcessPluginOne::CompareData(RuleObject rule, BaseDataType *data)
{
   ResultObject *obj = NULL;
   // This method checks out fine
   if(data->GetSomeBaseMethod())
   {
      // This cast below FAILS every time in gcc but passes in Visual Studio
      SpecificObject *obj = dynamic_cast<SpecificObject*>(data);
      if(obj)
      { 
           ... Do Something ...
      }
   }
   return result;
}

同样，所有这些都可以在VisualStudio下工作，但不能在GCC下工作。为了调试程序，我开始在不同的部分添加一些代码。当我在主流程中完成以下操作时，我终于让它工作了（见下面添加的代码）：

// In process with Modification
void receive_data(void *buff, int size,DataTypeEnum type)
{
   // Get the plugin associated with this data
   ProcessPlugin *plugin = m_plugins[type];
   // Since we need to cast the data properly into its actual type and not its
   // base data type we need the plugin to cast it for us (so we can keep the 
   // process generic)
   BaseDataType *data = plugin->getDataObject(buff);
   if(data)
   {
     // Cast worked just fine 
     .... Other things happen (but object isn't modified) ....
     // Now compare our rule
     RuleObject obj = getRule();
     /** I included the specific data types in as headers for debugging and linked in 
      * all the specific classes and added the following code
      */
     SpecificObject *test_obj = dynamic_cast<SpecificObject*>(data);
     if(test_obj)
        cout << "Our was Data was casted correctly!" << endl;
     /// THE CODE ABOVE FIXES THE BAD CAST IN MY PLUGIN EVEN THOUGH 
     /// THE CODE ABOVE IS ALL I DO

     ResultObject *result = plugin->CompareData(obj,data);
     if(result)
        ... Success Case ...
     else
        ... Error Case ...
   } 
}

重要过程编译选项：

Compile: -m64 -fPIC -wno-non-template-friend -DNDEGBUG -I <Includes>
Link: -Wl -z muldefs -m64

重要插件编译选项

Compile: -Wall -wno-non-template-friend -O -O2
Link: -Wl -Bstatic -Bdynamic -z muldefs -shared -m64

由于我没有修改对象"数据"，我不知道为什么程序的其余部分会突然开始工作。我唯一能想到的是，虚拟表在这个过程中的某个地方被剥离了，"额外"的动态演员阵容迫使主进程保留表（这仍然没有多大意义）。

我试着去掉了gcc中的所有优化设置，它仍然是一样的。有什么想法吗？

谢谢。