Export Qt Creator's special properties

That we add to plugin targets, so these are also available when building
external plugins. Helps for e.g. recursive PLUGIN_DEPENDS.

Change-Id: I89b10a58a9aa3ceb720c0dff4b76564d1cb06ca3
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

cmake/QtCreatorAPI.cmake

@@ -556,8 +556,8 @@ function(add_qtc_plugin target_name)
     CXX_EXTENSIONS OFF
     CXX_VISIBILITY_PRESET hidden
     VISIBILITY_INLINES_HIDDEN ON
-    _arg_DEPENDS "${_arg_PLUGIN_DEPENDS}"
+    QTC_PLUGIN_DEPENDS "${_arg_PLUGIN_DEPENDS}"
-    _arg_VERSION "${_arg_VERSION}"
+    QTC_PLUGIN_VERSION "${_arg_VERSION}"
     BUILD_RPATH "${_PLUGIN_RPATH};${CMAKE_BUILD_RPATH}"
     INSTALL_RPATH "${_PLUGIN_RPATH};${CMAKE_INSTALL_RPATH}"
     LIBRARY_OUTPUT_DIRECTORY "${_output_binary_dir}/${plugin_dir}"
@@ -570,6 +570,9 @@ function(add_qtc_plugin target_name)
     ${_arg_PROPERTIES}
   )
 
+  set_property(TARGET ${target_name} APPEND PROPERTY EXPORT_PROPERTIES
+      "QTC_PLUGIN_CLASS_NAME;QTC_PLUGIN_DEPENDS;QTC_PLUGIN_VERSION")
+
   if (NOT _arg_SKIP_PCH)
     enable_pch(${target_name})
   endif()

cmake/QtCreatorAPIInternal.cmake

@@ -364,7 +364,7 @@ function(find_dependent_plugins varName)
       continue()
     endif()
     set(_dep)
-    get_property(_dep TARGET "${i}" PROPERTY _arg_DEPENDS)
+    get_property(_dep TARGET "${i}" PROPERTY QTC_PLUGIN_DEPENDS)
     if (_dep)
       find_dependent_plugins(_REC ${_dep})
       list(APPEND _RESULT ${_REC})