only build xercesc if xml input format support is required

Former-commit-id: ce58e72eed

CMakeLists.txt

@@ -34,6 +34,7 @@ set(MSAT_ROOT "" CACHE STRING "The root directory of MathSAT (if available).")
 set(ADDITIONAL_INCLUDE_DIRS "" CACHE STRING "Additional directories added to the include directories.")
 set(ADDITIONAL_LINK_DIRS "" CACHE STRING "Additional directories added to the link directories.")
 set(CUSTOM_BOOST_ROOT "" CACHE STRING "A custom path to the Boost root directory.")
+set(STORM_SUPPORT_XML_INPUT_FORMATS 0)
 
 # If the DEBUG option was turned on, we will target a debug version and a release version otherwise.
 if (STORM_DEBUG)

resources/3rdparty/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_custom_target(resources) 
 add_custom_target(test-resources)
 
+if(STORM_SUPPORT_XML_FORMATS)
     include(ExternalProject)
     ExternalProject_Add(
             xercesc
@@ -14,6 +15,7 @@ ExternalProject_Add(
             LOG_INSTALL ON
     )
     add_dependencies(resources xercesc)
+endif()
 
 ExternalProject_Add(
     glpk