Add handling for missing nvml lib

app/CMakeLists.txt

@@ -4,15 +4,29 @@ project(fantasize VERSION 0.1.7)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
-find_package(nlohmann_json 3.11.2 REQUIRED)
+find_package(nlohmann_json 3.7 REQUIRED)
 find_package(Boost 1.80 COMPONENTS program_options log log_setup date_time REQUIRED)
 
+find_library(NVML_LIB nvidia-ml)
+
+set(ADDITIONAL_LIBS)
+
+if (NVML_LIB)
+    set(HAVE_NVML)
+
+    add_library(nvidia-sensor-lib STATIC
+      src/sensor/NvidiaSensor.cxx
+      src/sensor/GPUSensorsFacade.cxx)
+
+    target_link_libraries(nvidia-sensor-lib PUBLIC NVML_LIB)
+
+    list(APPEND ADDITIONAL_LIBS nvidia-sensor-lib)
+endif()
+
 add_executable(${PROJECT_NAME}
   src/main.cxx
   src/sensor/LMSensorsFacade.cxx
-  src/sensor/GPUSensorsFacade.cxx
   src/sensor/Sensor.cxx
-  src/sensor/NvidiaSensor.cxx
   src/sensor/LMSensor.cxx
   src/pwm/PWMControl.cxx
   src/pwm/PWMControlFacade.cxx
@@ -30,7 +44,8 @@ add_executable(${PROJECT_NAME}
 set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 20)
 
 target_include_directories(${PROJECT_NAME} PUBLIC include /opt/cuda)
-target_link_libraries(${PROJECT_NAME} PUBLIC sensors nvidia-ml nlohmann_json::nlohmann_json tbb ${Boost_LIBRARIES})
+
+target_link_libraries(${PROJECT_NAME} PUBLIC sensors nlohmann_json::nlohmann_json tbb ${Boost_LIBRARIES} ${ADDITIONAL_LIBS})
 
 install(TARGETS ${PROJECT_NAME} DESTINATION usr/local/bin)
 install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/unit/fantasize.service DESTINATION usr/lib/systemd/system)