only load backend_cuda when available

CMakeLists.txt

@@ -6,8 +6,14 @@ file(STRINGS "${CMAKE_SOURCE_DIR}/version.txt" version)
 project(aidge_learning
         VERSION ${version}
         DESCRIPTION "Functions and alogrithms to train models in the AIDGE framework" 
-        LANGUAGES CXX CUDA)
+        LANGUAGES CXX)
 
+# Try to find CUDA
+find_package(CUDAToolkit)
+
+if(CUDAToolkit_FOUND)
+    enable_language(CUDA)
+endif()
 message(STATUS "Project name: ${CMAKE_PROJECT_NAME}")
 message(STATUS "Project version: ${version}")
 

unit_tests/CMakeLists.txt

@@ -22,25 +22,32 @@ if(NOT DEFINED CMAKE_CUDA_STANDARD)
   set(CMAKE_CUDA_STANDARD_REQUIRED ON)
 endif()
 
-enable_language(CUDA)
-find_package(CUDAToolkit REQUIRED)
-
-target_link_libraries( _aidge_backend_cuda
-      INTERFACE
-      cudart  # Ensure CUDA dependencies are included
-      cublas  # Include other CUDA components if needed
-      cudnn
+target_link_libraries(tests_exe
+  PUBLIC ${module_name} _aidge_backend_cpu
+  PRIVATE Catch2::Catch2WithMain
 )
 
-target_include_directories(_aidge_backend_cuda INTERFACE ${CUDAToolkit_INCLUDE_DIRS})
+if(aidge_backend_cuda_FOUND)
+  enable_language(CUDA)
+  find_package(CUDAToolkit REQUIRED)
 
-target_link_libraries(tests_exe
-      PUBLIC ${module_name} _aidge_backend_cpu _aidge_backend_cuda
-      PRIVATE Catch2::Catch2WithMain
-)
+  target_link_libraries( _aidge_backend_cuda
+        INTERFACE
+        cudart  # Ensure CUDA dependencies are included
+        cublas  # Include other CUDA components if needed
+        cudnn
+  )
+
+  target_include_directories(_aidge_backend_cuda INTERFACE ${CUDAToolkit_INCLUDE_DIRS})
+
+  target_link_libraries(tests_exe
+        PUBLIC ${module_name} _aidge_backend_cuda
+  )
+
+  # Define a preprocessor macro if aidge_backend_cuda is linked
+  target_compile_definitions(tests_exe PUBLIC USE_AIDGE_BACKEND_CUDA)
+endif()
 
-# Define a preprocessor macro if aidge_backend_cuda is linked
-target_compile_definitions(tests_exe PUBLIC USE_AIDGE_BACKEND_CUDA)
 
 list(APPEND CMAKE_MODULE_PATH ${catch2_SOURCE_DIR}/extras)
 include(CTest)