target arm64e-apple-darwin removing functions

[ds-ep]

I tried this code:

use ctor::ctor;

#[ctor]
fn testAAAA() {
    println!("TEST123");
    panic!();
}

pub fn test123() {
    println!("TEST123");
}

I expected to see this happen:
without specifying a target everything works fine (using cargo +nightly build)

Instead, this happened:
when i specify arm64e-apple-darwin (using: cargo +nightly build -Z build-std --target arm64e-apple-darwin) my function seems to be removed.

compiling both as dylib

Meta

rustc --version --verbose:

binary: rustc
commit-hash: eeb90cda1969383f56a2637cbd3037bdf598841c
commit-date: 2024-09-04
host: aarch64-apple-darwin
release: 1.81.0
LLVM version: 18.1.7

From aarch64-apple-darwin build in ghidra

whereas on the arm64e build there is no functions at all :|

CC @arttet

[bjorn3]

This is probably #130085. You can try linking using lld or downgrading to XCode 14 or lower. The issue I think this is only happens with the linker of XCode 15.

[ds-ep]

@bjorn3 I have xcode 16 btw, issue still exists. I tried using lld but then the output is arm64 not arm64e, and as far as im aware lld does not support arg -arch arm64e yet

[bjorn3]

I think your options for now are limited to downgrading to XCode 14 or trying to compile rustc against Apple's LLVM fork (https://github.com/swiftlang/llvm-project). XCode 14 should be compatible with the arm64e abi in upstream LLVM, and using Apple's LLVM fork should make rustc able to emit the new arm64e abi.

[arttet]

Hey @ds-ep,

I believe this is connected to the issue.

$ clang --version
Homebrew clang version 19.1.2
Target: x86_64-apple-darwin24.0.0
Thread model: posix
InstalledDir: /usr/local/Cellar/llvm/19.1.2/bin

$ echo "int main() { return 0; }" > foo.c
$ clang -o llvm_foo.o -c foo.c --target=arm64e-apple-darwin
$ clang -o llvm_foo llvm_foo.o --target=arm64e-apple-darwin -fuse-ld=lld
$ file llvm_foo
llvm_foo: Mach-O 64-bit executable arm64

So, there are significant differences between Apple's LLVM and the upstream LLVM.

[arttet]

This is also the known issue. We have to force using XCode 14. It seems that Apple's LLVM is not compatible with Rust and requires many patches.

[ds-ep]

For anyone coming across this on MacOS 15 where Xcode 14 is not compatible and will refuse to install. you can download CL tools for xcode 14 here: https://developer.apple.com/download/all/ and use that.