Add top-level CMake backends target

ghstack-source-id: b51770c
ghstack-comment-id: 3099241838
Pull-Request: #12689

Author: GregoryComer

CMakeLists.txt

@@ -351,6 +351,9 @@ add_library(executorch_core ${_executorch_core__srcs})
 # Legacy name alias.
 add_library(executorch_no_prim_ops ALIAS executorch_core)
 
+# A list of all configured backends.
+set(_executorch_backends "")
+
 target_link_libraries(executorch_core PRIVATE program_schema)
 if(ANDROID)
   target_link_libraries(executorch_core PUBLIC log)
@@ -494,6 +497,7 @@ install(FILES tools/cmake/Utils.cmake tools/cmake/executorch-config.cmake
 
 if(EXECUTORCH_BUILD_ARM_BAREMETAL)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/arm)
+  list(APPEND _executorch_backends executorch_delegate_ethos_u)
 endif()
 
 if(EXECUTORCH_BUILD_CADENCE)
@@ -502,30 +506,37 @@ endif()
 
 if(EXECUTORCH_BUILD_NXP_NEUTRON)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/nxp)
+  list(APPEND _executorch_backends executorch_delegate_neutron)
 endif()
 
 if(EXECUTORCH_BUILD_COREML)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/apple/coreml)
+  list(APPEND _executorch_backends coremldelegate)
 endif()
 
 if(EXECUTORCH_BUILD_MPS)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/apple/mps)
+  list(APPEND _executorch_backends mpsdelegate)
 endif()
 
 if(EXECUTORCH_BUILD_NEURON)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/mediatek)
+  list(APPEND _executorch_backends neuron_backend)
 endif()
 
 if(EXECUTORCH_BUILD_OPENVINO)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/openvino)
+  list(APPEND _executorch_backends openvino_backend)
 endif()
 
 if(EXECUTORCH_BUILD_QNN)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/qualcomm)
+  list(APPEND _executorch_backends qnn_executorch_backend)
 endif()
 
 if(EXECUTORCH_BUILD_XNNPACK)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/xnnpack)
+  list(APPEND _executorch_backends xnnpack_backend)
 endif()
 
 if(EXECUTORCH_BUILD_CORTEX_M)
@@ -689,6 +700,17 @@ if(EXECUTORCH_BUILD_KERNELS_QUANTIZED)
   target_link_options_shared_lib(quantized_ops_lib)
 endif()
 
+if(EXECUTORCH_BUILD_VULKAN)
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backends/vulkan)
+  list(APPEND _executorch_backends vulkan_backend)
+endif()
+
+# Top-level interface targets.
+add_library(executorch_backends INTERFACE)
+
+# A target containing all configured backends.
+target_link_libraries(executorch_backends INTERFACE ${_executorch_backends})
+
 if(EXECUTORCH_BUILD_EXECUTOR_RUNNER)
   # Baseline libraries that executor_runner will link against.
   set(_executor_runner_libs executorch gflags)

tools/cmake/executorch-config.cmake

@@ -57,18 +57,28 @@ set(EXECUTORCH_FOUND ON)
 
 target_link_libraries(executorch INTERFACE executorch_core)
 
-set(lib_list
-    flatccrt
-    etdump
-    bundled_program
-    extension_data_loader
-    extension_flat_tensor
+set(backend_lib_list
     coreml_util
     coreml_inmemoryfs
     coremldelegate
     mpsdelegate
     neuron_backend
     qnn_executorch_backend
+    # Start XNNPACK Lib Deps
+    XNNPACK
+    xnnpack-microkernels-prod
+    kleidiai
+    # End XNNPACK Lib Deps
+    xnnpack_backend
+    vulkan_backend
+)
+
+set(lib_list
+    flatccrt
+    etdump
+    bundled_program
+    extension_data_loader
+    extension_flat_tensor
     portable_ops_lib
     custom_ops
     extension_module
@@ -77,15 +87,8 @@ set(lib_list
     extension_tensor
     extension_threadpool
     extension_training
-    xnnpack_backend
-    # Start XNNPACK Lib Deps
-    XNNPACK
-    xnnpack-microkernels-prod
-    kleidiai
-    # End XNNPACK Lib Deps
     cpuinfo
     pthreadpool
-    vulkan_backend
     optimized_kernels
     optimized_portable_kernels
     cpublas
@@ -96,6 +99,9 @@ set(lib_list
     quantized_ops_lib
     quantized_ops_aot_lib
 )
+
+list(APPEND lib_list ${backend_lib_list})
+
 foreach(lib ${lib_list})
   # Name of the variable which stores result of the find_library search
   set(lib_var "LIB_${lib}")
@@ -198,3 +204,12 @@ if(TARGET xnnpack_backend)
   )
   target_link_options_shared_lib(xnnpack_backend)
 endif()
+
+# An interface target containing all available backends.
+add_library(executorch_backends INTERFACE)
+
+foreach(lib ${backend_lib_list})
+  if(TARGET ${lib})
+    target_link_options(executorch_backends INTERFACE ${lib})
+  endif()
+endforeach()