build, lte: Only enable emulation features when EmuNetDevice dependencies are met

build-support/macros-and-definitions.cmake

@@ -1174,6 +1174,15 @@ macro(process_options)
     set(ENABLE_TAP OFF)
     set(ENABLE_EMU OFF)
     set(ENABLE_FDNETDEV FALSE)
+    mark_as_advanced(
+      ENABLE_FDNETDEV ENABLE_DPDKDEVNET ENABLE_TAPNETDEV ENABLE_EMUNETDEV
+      ENABLE_NETMAP_EMU
+    )
+    set(ENABLE_FDNETDEV False CACHE INTERNAL "")
+    set(ENABLE_DPDKDEVNET False CACHE INTERNAL "")
+    set(ENABLE_TAPNETDEV False CACHE INTERNAL "")
+    set(ENABLE_EMUNETDEV False CACHE INTERNAL "")
+    set(ENABLE_NETMAP_EMU False CACHE INTERNAL "")
     list(REMOVE_ITEM libs_to_build fd-net-device)
     message(
       STATUS

src/lte/CMakeLists.txt

@@ -2,7 +2,9 @@ set(emu_sources)
 set(emu_headers)
 set(emu_features)
 set(emu_libraries)
-if(${ENABLE_EMU})
+if(${ENABLE_EMU}
+   AND ${ENABLE_EMUNETDEV}
+)
   set(emu_sources
       helper/emu-epc-helper.cc
   )

src/lte/examples/CMakeLists.txt

@@ -36,7 +36,9 @@ foreach(
   )
 endforeach()
 
-if(${ENABLE_EMU})
+if(${ENABLE_EMU}
+   AND ${ENABLE_EMUNETDEV}
+)
   build_lib_example(
     NAME lena-simple-epc-emu
     SOURCE_FILES lena-simple-epc-emu.cc