[Build] passing --arm64 to ci_build/build.py has error in arm64 host

[aungthetnaing]

Describe the issue

--arm64 should not mean that there is cross-compilation. --arm64 flag should work in both arm64 and x64 hosts.

After this PR 8d09baf

--arm64 flag in arm64 host will fail with the following error-check.

CMAKE_HOST_SYSTEM_NAME: Windows CMake Error at external/onnxruntime_external_deps.cmake:189 (message): ONNX_CUSTOM_PROTOC_EXECUTABLE must be set to cross-compile. Call Stack (most recent call first): CMakeLists.txt:586 (include)

Urgency

No response

Target platform

arm64

Build script

build.bat --build_shared_lib --config Release --parallel --skip_submodule_sync --skip_tests --use_binskim_compliant_compile_flags --msvc_toolset v143 --arm64 --enable_msvc_static_runtime --cmake_extra_defines onnxruntime_BUILD_UNIT_TESTS=OFF "CMAKE_C_FLAGS=/Qspectre /guard:cf /Zi" "CMAKE_CXX_FLAGS=/Qspectre /guard:cf /Zi" "CMAKE_SHARED_LINKER_FLAGS=/guard:cf /DYNAMICBASE /DEBUG" "CMAKE_EXE_LINKER_FLAGS=/guard:cf /DYNAMICBASE /DEBUG"

Error / output

CMAKE_HOST_SYSTEM_NAME: Windows
CMake Error at external/onnxruntime_external_deps.cmake:189 (message):
ONNX_CUSTOM_PROTOC_EXECUTABLE must be set to cross-compile.
Call Stack (most recent call first):
CMakeLists.txt:586 (include)

Visual Studio Version

VS2022

GCC / Compiler Version

No response

[snnn]

Please download protobuf 3.21.12 from https://www.nuget.org/packages/Google.Protobuf, unzip the package, then set ONNX_CUSTOM_PROTOC_EXECUTABLE to the path of the x64 version of protoc.exe. Put ONNX_CUSTOM_PROTOC_EXECUTABLE
in cmake_extra_defines .

[aungthetnaing]

Please download protobuf 3.21.12 from https://www.nuget.org/packages/Google.Protobuf, unzip the package, then set ONNX_CUSTOM_PROTOC_EXECUTABLE to the path of the x64 version of protoc.exe. Put ONNX_CUSTOM_PROTOC_EXECUTABLE in cmake_extra_defines .

This step is not required for --arm64 flag run in host x64. So, I believe we should fix it in a way that --arm64 flag will behave the same in both x64 and arm64 host.

[skottmckay]

Platform flags like --arm64 or --x86 are intended for cross compiling. If you're not cross-compiling, simply don't add the --arm64 flag.