Use POSITION_INDEPENDENT_CODE CMake property.

Added new BUILD_STATIC_PIC configuration option, PIC is now set only
when needed/requested.

src/MagnumPlugins/AnyImageImporter/CMakeLists.txt

@@ -29,17 +29,25 @@ set(AnyImageImporter_SRCS
 set(AnyImageImporter_HEADERS
     AnyImageImporter.h)
 
+# Objects shared between plugin and test library
 add_library(AnyImageImporterObjects OBJECT
     ${AnyImageImporter_SRCS}
     ${AnyImageImporter_HEADERS})
-set_target_properties(AnyImageImporterObjects PROPERTIES COMPILE_FLAGS "${CMAKE_SHARED_LIBRARY_CXX_FLAGS} -DAnyImageImporterObjects_EXPORTS")
+set_target_properties(AnyImageImporterObjects PROPERTIES COMPILE_FLAGS "-DAnyImageImporterObjects_EXPORTS")
+if(NOT BUILD_STATIC OR BUILD_STATIC_PIC)
+    set_target_properties(AnyImageImporterObjects PROPERTIES POSITION_INDEPENDENT_CODE ON)
+endif()
 
+# AnyImageImporter plugin
 add_plugin(AnyImageImporter ${MAGNUM_PLUGINS_IMPORTER_DEBUG_INSTALL_DIR} ${MAGNUM_PLUGINS_IMPORTER_RELEASE_INSTALL_DIR}
     AnyImageImporter.conf
     $<TARGET_OBJECTS:AnyImageImporterObjects>
     pluginRegistration.cpp)
-target_link_libraries(AnyImageImporter
-    ${MAGNUM_LIBRARIES})
+if(BUILD_STATIC_PIC)
+    set_target_properties(AnyImageImporter PROPERTIES POSITION_INDEPENDENT_CODE ON)
+endif()
+
+target_link_libraries(AnyImageImporter ${MAGNUM_LIBRARIES})
 
 install(FILES ${AnyImageImporter_HEADERS} DESTINATION ${MAGNUM_PLUGINS_INCLUDE_INSTALL_DIR}/AnyImageImporter)