PCL_EXPORTS seems to be implemented wrong

I currently still trying to compile everything with MSVC. I could fix already a lot of issues, but there is an error I couldn't fix:

LNK2001	unresolved external symbol "public: static struct QMetaObject const pcl::cloud_composer::PropertiesModel::staticMetaObject" (?staticMetaObject@PropertiesModel@cloud_composer@pcl@@2UQMetaObject@@B)	pcl_cc_tool_fpfh_estimation

In general I could fix all linker errors, except where we export a target with Q_OBJECT:

    class PCL_EXPORTS AbstractTool : public QObject
    {
      Q_OBJECT
      //...
    }

If you search the web for this issue you always find, that we need __declspec(dllimport). But PCL_EXPORTS expand always to __declspec(dllexport) or empty.

Further issue: PCL_ADD_LIBRARY always add symbol PCLAPI_EXPORTS. This seems at first look correct, but I believe this is partially wrong.

• Case 1: Someone build PCL and use installed libraries. In this case everything is fine, because PCLAPI_EXPORTS is not defined
• Case 2: A PCL library (LibA) is using another PCL library (LibB). In this case PCLAPI_EXPORTS should be true for all header files part of LibB but no defined for LibA during building LibB. So I believe it would be correct if define PCL_LibA_EXPORTS and PCL_LibB_EXPORTS instead of just PCL_EXPORTS.

And we use should CMake::GenerateExportHeader.

Start by reproducing the MSVC linker failure for Q_OBJECT classes and trace how PCL_EXPORTS and PCL_ADD_LIBRARY define export symbols. Compare the current behavior with CMake::GenerateExportHeader and verify that dependent libraries receive the correct import or export annotations without unresolved staticMetaObject symbols.