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dllconditional-compilationfunction

Can I use #ifdef in a .def?

Can I use #ifdef sections in a .def file for a dll? E.g.:

LIBRARY "mydll"
EXPORTS
  checkRequirements
  createDevice
  installDriver
  isPastVersionInstalled
  removeDevice
  #ifdef myVar
  doSomethingElse
  #endif
Solution

  • No, not possible, it is not a file that's pre-processed. Although I supposed you could by running the preprocessor to generate another .def file and link that one.

    The more effective approach is to eliminate the need for a .def file completely. Use __declspec(dllexport) in your code on the functions that should be exported. Then any #ifdef in that code will automatically ensure that a function is neither compiled nor exported.