Add macos_kernel_link_options for MacOS (#70)

Summary:
This addresses the linker issue on MacOS `ld: unknown option: --whole-archive`

Pull Request resolved: #70

Reviewed By: larryliu0820

Differential Revision: D48411148

Pulled By: huydhn

fbshipit-source-id: 7e8839dbf698c8290d4989f2ec00464659f700a2

Author: huydhn

CMakeLists.txt

@@ -259,7 +259,11 @@ target_link_libraries(portable_kernels_bindings INTERFACE portable_kernels)
 
 # Ensure that the load-time constructor functions run. By default, the linker
 # would remove them since there are no other references to them.
-kernel_link_options(portable_kernels_bindings)
+if(APPLE)
+  macos_kernel_link_options(portable_kernels_bindings)
+else()
+  kernel_link_options(portable_kernels_bindings)
+endif()
 
 #
 # executor_runner: A simple commandline tool that loads and runs a program file.

build/Utils.cmake

@@ -32,3 +32,11 @@ function(kernel_link_options target_name)
         -Wl,--no-whole-archive
     )
 endfunction()
+
+function(macos_kernel_link_options target_name)
+    target_link_options(${target_name}
+        INTERFACE
+        # Same as kernel_link_options but it's for MacOS linker
+        -Wl,-force_load,$<TARGET_FILE:${target_name}>
+    )
+endfunction()

examples/custom_ops/CMakeLists.txt

@@ -110,7 +110,11 @@ if(REGISTER_EXAMPLE_CUSTOM_OP_2)
 
   # Ensure that the load-time constructor functions run. By default, the linker
   # would remove them since there are no other references to them.
-  kernel_link_options("custom_ops_aot_lib")
+  if(APPLE)
+    macos_kernel_link_options("custom_ops_aot_lib")
+  else()
+    kernel_link_options("custom_ops_aot_lib")
+  endif()
 endif()
 
 # 1. C++ library to register custom ops into Executorch runtime.