Patch changes needed for ios/android build

Summary:
Mostly tweaks for android/ios tool chain

iOS doesn't like binary

Android tool chains seems using clang but the default one is not linking the kernel library and the `--whole-archive` works

Reviewed By: larryliu0820

Differential Revision: D48203714

fbshipit-source-id: 731bb13068fc61f06725d5b08af667b64d088aee

Author: cccclai

CMakeLists.txt

@@ -42,6 +42,7 @@
 
 cmake_minimum_required(VERSION 3.13)
 project(executorch)
+include(build/Utils.cmake)
 
 # option to register custom operator `my_ops::mul3` in
 # `examples/custom_ops/custom_ops_1.py`
@@ -260,33 +261,35 @@ target_link_libraries(portable_kernels_bindings INTERFACE portable_kernels)
 # would remove them since there are no other references to them.
 if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang" OR CMAKE_CXX_COMPILER_ID STREQUAL
                                              "AppleClang")
-  target_link_options(
-    portable_kernels_bindings
-    INTERFACE
-    # TODO(dbort): This will cause the .a to show up on the link line twice for
-    # targets that depend on this library; once because CMake will add it, and
-    # once because it's in this list of args. See if there's a way to avoid
-    # that.
-    -Wl,-force_load,libportable_kernels_bindings.a)
-elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  if(CMAKE_TOOLCHAIN_FILE MATCHES ".*android\.toolchain\.cmake$")
+    # For Android tool chain
+    gcc_kernel_link_options(portable_kernels_bindings)
+  else()
+    # For host tool chain
+    clang_kernel_link_options(portable_kernels_bindings)
+  endif()
+elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
   # Using gcc
-  target_link_options(
-    portable_kernels_bindings INTERFACE
-    # TODO(dbort): This will cause the .a to show up on the link line twice
-    -Wl,--whole-archive libportable_kernels_bindings.a -Wl,--no-whole-archive)
+  gcc_kernel_link_options(portable_kernels_bindings)
 endif()
 
 #
 # executor_runner: A simple commandline tool that loads and runs a program file.
 #
 
-add_executable(executor_runner ${_executor_runner__srcs})
-target_link_libraries(executor_runner executorch portable_kernels_bindings
-                      gflags)
-target_compile_options(executor_runner PUBLIC ${_common_compile_options})
+# ios can only build library but not binary
+if(NOT CMAKE_TOOLCHAIN_FILE MATCHES ".*ios\.toolchain\.cmake$")
+  add_executable(executor_runner ${_executor_runner__srcs})
+  target_link_libraries(executor_runner executorch portable_kernels_bindings
+                        gflags)
+  target_compile_options(executor_runner PUBLIC ${_common_compile_options})
+endif()
 
 # Generate custom_ops_lib based on REGISTER_EXAMPLE_CUSTOM_OPS
 if(REGISTER_EXAMPLE_CUSTOM_OP_1 OR REGISTER_EXAMPLE_CUSTOM_OP_2)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/examples/custom_ops)
   target_link_libraries(executor_runner custom_ops_lib)
 endif()
+
+# Print all summary
+executorch_print_configuration_summary()

build/Utils.cmake

@@ -0,0 +1,46 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+# This file is intended to have helper functions to keep the CMakeLists.txt concise. If there are any helper function can be re-used, it's recommented to add them here.
+
+
+# Public function to print summary for all configurations. For new variable, it's recommended to add them here.
+function(executorch_print_configuration_summary)
+    message(STATUS "")
+    message(STATUS "******** Summary ********")
+    message(STATUS "  BUCK                          : ${BUCK2}")
+    message(STATUS "  CMAKE_CXX_STANDARD            : ${CMAKE_CXX_STANDARD}")
+    message(STATUS "  CMAKE_CXX_COMPILER_ID         : ${CMAKE_CXX_COMPILER_ID}")
+    message(STATUS "  CMAKE_TOOLCHAIN_FILE          : ${CMAKE_TOOLCHAIN_FILE}")
+    message(STATUS "  FLATBUFFERS_BUILD_FLATC       : ${FLATBUFFERS_BUILD_FLATC}")
+    message(STATUS "  FLATBUFFERS_BUILD_FLATHASH    : ${FLATBUFFERS_BUILD_FLATHASH}")
+    message(STATUS "  FLATBUFFERS_BUILD_FLATLIB     : ${FLATBUFFERS_BUILD_FLATLIB}")
+    message(STATUS "  FLATBUFFERS_BUILD_TESTS       : ${FLATBUFFERS_BUILD_TESTS}")
+    message(STATUS "  REGISTER_EXAMPLE_CUSTOM_OPS   : ${REGISTER_EXAMPLE_CUSTOM_OPS}")
+endfunction()
+
+# This is the funtion to use -Wl to link static library, used for clang
+function(clang_kernel_link_options target_name)
+    target_link_options(${target_name}
+        INTERFACE
+        # TODO(dbort): This will cause the .a to show up on the link line twice
+        # for targets that depend on this library; once because CMake will add
+        # it, and once because it's in this list of args. See if there's a way
+        # to avoid that.
+        -Wl,$<TARGET_FILE:${target_name}>
+    )
+endfunction()
+
+# This is the funtion to use -Wl, --whole-archive to link static library, used for gcc
+function(gcc_kernel_link_options target_name)
+    target_link_options(${target_name}
+        INTERFACE
+        # TODO(dbort): This will cause the .a to show up on the link line twice
+        -Wl,--whole-archive
+        $<TARGET_FILE:${target_name}>
+        -Wl,--no-whole-archive
+    )
+endfunction()