Make sure that LCIO target is also available downstream (#59)

* Make sure that LCIO target is also available downstream

* Remove deprecated CMake variables for LCIO

CMakeLists.txt

@@ -38,8 +38,8 @@ endif()
 FIND_PACKAGE( GEAR REQUIRED )
 
 # export Marlin_DEPENDS_INCLUDE_DIRS to MarlinConfig.cmake
-SET( Marlin_DEPENDS_INCLUDE_DIRS ${LCIO_INCLUDE_DIRS} ${GEAR_INCLUDE_DIRS} ${streamlog_INCLUDE_DIRS} )
-SET( Marlin_DEPENDS_LIBRARY_DIRS ${LCIO_LIBRARY_DIRS} ${GEAR_LIBRARY_DIRS} ${streamlog_LIBRARY_DIRS} )
+SET( Marlin_DEPENDS_INCLUDE_DIRS ${GEAR_INCLUDE_DIRS} ${streamlog_INCLUDE_DIRS} )
+SET( Marlin_DEPENDS_LIBRARY_DIRS ${GEAR_LIBRARY_DIRS} ${streamlog_LIBRARY_DIRS} )
 SET( Marlin_DEPENDS_LIBRARIES LCIO::lcio ${GEAR_LIBRARIES} ${streamlog_LIBRARIES} )
 
 INCLUDE_DIRECTORIES( SYSTEM ${Marlin_DEPENDS_INCLUDE_DIRS} )

cmake/MarlinConfig.cmake.in

@@ -53,6 +53,19 @@ CHECK_PACKAGE_LIBS( Marlin Marlin MarlinXML )
 
 
 # ---------- dependencies -----------------------------------------------------
+include(CMakeFindDependencyMacro)
+find_dependency(LCIO)
+if(NOT TARGET LCIO::lcio)
+  message(STATUS "LCIO found without targets, bootstrapping them")
+  add_library(LCIO::lcio INTERFACE IMPORTED GLOBAL)
+  set_target_properties(LCIO::lcio
+    PROPERTIES
+    INTERFACE_INCLUDE_DIRECTORIES "${LCIO_INCLUDE_DIRS}"
+    INTERFACE_LINK_LIBRARIES "${LCIO_LIBRARIES}"
+  )
+endif()
+
+
 INCLUDE( "@ILCSOFT_CMAKE_MODULES_ROOT@/MacroExportPackageDeps.cmake" )
 # exports following package dependencies (if set)
 # first argument of macro should be the package name