Mac Arm64 Support & Example?

[cjgratacos]

Thanks for the awesome tool.

I was wondering if it is possible to cross compile to aarch64-apple-darwin rust target (arm64 darwin) since this is using https://github.com/tpoechtrager/osxcross? If so can an example be given and update the read me with it? I know the Readme talks about it but it is not clear and it doesn't work.

Example of how I am trying to compile the project:

docker run --rm \
    --volume "${PWD}/":/root/src:z \
    --workdir /root/src \
    joseluisq/rust-linux-darwin-builder:1.57.0 \
    sh -c "rustup target add aarch64-apple-darwin && CC=oa64-clang CXX=oa64-clang++ LIBZ_SYS_STATIC=1 cargo build --release --target aarch64-apple-darwin"

[joseluisq]

The image is amd64 only. So it's not supported out-of-the-box from the Docker image standing point.
However yeah it's possible to cross compile to aarch64-apple-darwin since we are using osxcross but this involves more setup to do.

So this issue should be a nice to have feature request.

[xrl]

What is the more work required? I started building aarch64 (but don't have an ARM64 Darwin laptop yet) with:

    rustup target add aarch64-apple-darwin      && \

added in to the Dockerfile. Then in my app's CI I can build the binary with:

    cargo build --target aarch64-apple-darwin --release

and my cargo-config.toml has this entry:

[target.aarch64-apple-darwin]
linker = "arm64e-apple-darwin21.1-clang"
ar = "arm64e-apple-darwin21.1-ar"

with all three of those tweaks, my CI builds go through, no error. The compiled aarch64 binary looks about the right size as the other artifacts. Your mileage may vary!

[joseluisq]

Yeah, that also was my impression at first glance. Like touching cargo config and adding the corresponding toolchain.
Honestly I didn't tried myself aarch64-apple-darwin since I don't target it.
But as I said should work unless the reporter needs some specific things.

[cjgratacos]

Sorry for the delay response, but the following works:

• adding the following to ./.cargo/config.toml

[target.aarch64-apple-darwin]
linker = "arm64e-apple-darwin21.1-clang"
ar = "arm64e-apple-darwin21.1-ar"

• running the following on the root of the project:

docker run --rm \
    --volume "${PWD}/":/root/src:z \
    --workdir /root/src \
    joseluisq/rust-linux-darwin-builder:1.60.0 \
    sh -c "rustup target add aarch64-apple-darwin && CC=oa64-clang CXX=oa64-clang++ LIBZ_SYS_STATIC=1 cargo build --release --target aarch64-apple-darwin"

Thanks to @xrl for the suggestion :)

[joseluisq]

Released on v1.65.0

[CGamesPlay]

Just wanted to publicly document some stupidity on my part. o64-clang is for x86_64, and oa64-clang is for aarch64. If you don't notice the "a", you will get many strange errors that do not appear to have anything to do with the C compiler. Here are a handful of the errors that I got that were all caused by using the wrong value for CC/CXX:

• NEON intrinsics not available with the soft-float ABI. Please use -mfloat-abi=softfp or -mfloat-abi=hard
  Attempting to add these flags would result in "ignored parameter" warnings, since the compiler you are using is wrong.
• ld: in .../target/aarch64-apple-darwin/release/deps/libring-0b5af5c61e1ef982.rlib(7effb53edfc7fa2d-mem.o), archive member '7effb53edfc7fa2d-mem.o' with length 3400 is not mach-o or llvm bitcode for architecture arm64
  Yep, because it was bitcode for x86_64.
• linking with `cc` failed: exit status: 1
  Rustc just uses the completely wrong linker (cc) despite the correct linker being configured. Unsure why this happens, but it's caused by using the wrong compiler.