prevent xercesc from being linked when no xml support is required

Former-commit-id: 63bf3c1a71

CMakeLists.txt

@@ -521,19 +521,21 @@ endif(ENABLE_MSAT)
 ##
 #############################################################
 
-find_package(Xerces)
-if(NOT XERCES_FOUND)
+if(STORM_SUPPORT_XML_INPUT_FORMATS)
+    find_package(Xerces)
+    if(NOT XERCES_FOUND)
             message(STATUS "Use shipped version of xerces")
             set(XERCES_ROOT ${CMAKE_BINARY_DIR}/resources/3rdparty/xercesc-3.1.2)
             set(XERCESC_INCLUDE ${XERCES_ROOT}/include)
             set(XERCES_LIBRARY_PATH ${XERCES_ROOT}/lib)
             set(XERCESC_LIBRARIES ${XERCES_LIBRARY_PATH}/libxerces-c.a)
-endif()
+    endif()
 
-set(STORM_HAVE_XERCES TRUE)
-if(STORM_HAVE_XERCES)
+    set(STORM_HAVE_XERCES TRUE)
+    if(STORM_HAVE_XERCES)
             include_directories(${XERCESC_INCLUDE})
             list(APPEND STORM_LINK_LIBRARIES ${XERCESC_LIBRARIES})
+    endif()
 endif()
 
 #############################################################