连接到DLL库？ [英] Connecting to DLL library?

问题描述

嗨伙计：

  在VS 2017社区开发，Win 10 Pro，所有C ++，没有MFC。 

   Developing on VS 2017 Community, Win 10 Pro, all C++, no MFC. 

  我有时会使用其他来源的图书馆。 我不记得遇到这个问题。 

   I sometimes use libraries from other sources.  I don't remember running into this problem. 

  我正在尝试链接到Botan加密库。 我在执行调试版本时收到此警告：

   I'm trying to link to the Botan crypto library.  I'm getting this warning when performing debug builds:

6>d:\utilities\code\windows_files\headers\botan\exceptn.h(22): 
   warning C4275: non dll-interface class 'std::exception' used as base for dll-interface class 'Botan::Exception'

  有问题的异常类：

   The exception class in question:

/**
* Base class for all exceptions thrown by the library
*/
class BOTAN_DLL Exception : public std::exception
   {
   public:
      explicit Exception(const std::string& msg) : m_msg(msg) {}
      Exception(const char* prefix, const std::string& msg) : m_msg(std::string(prefix) + " " + msg) {}
      const char* what() const BOTAN_NOEXCEPT override { return m_msg.c_str(); }
   private:
      std::string m_msg;
   };

  我不想改变Botan图书馆的来源。 我愿意将参数更改为其构建脚本。 

   I don't want to alter the Botan library's source.  I am open to changing parameters to its build script. 

  我需要做什么，源代码或构建参数，以避免此警告？

   What do I need to do on my end, source code or build parameters, to avoid this warning?

     谢谢你
     拉里

      Thanks
      Larry

推荐答案

据我所知，警告是因为std :: exception不是导出的类而引起的。 根据

https://social.msdn.microsoft.com/Forums/en-US/d3eb2bb6-03eb-4a2e-9c1a-94821905ba3f/warning-c4275-non-dllinterface-class?forum = vclanguage 如果使用相同的编译器构建指定了/ MD的所有模块，以便
共享相同的运行时，则可以安全地忽略此警告。

As I understand it the warning is caused because std::exception is not an exported class.  According to the discussion at https://social.msdn.microsoft.com/Forums/en-US/d3eb2bb6-03eb-4a2e-9c1a-94821905ba3f/warning-c4275-non-dllinterface-class?forum=vclanguage this warning may be safely ignored if the same compiler is used to build all modules with /MD specified so that they share the same runtime.

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