LLD ThinLto Issues with Swift codebase

[chiragramani]

When using thin lto with Swift, we see a couple of LLD crashes.

All crashes seen so far are in AArch64 Instruction Selection stages.

Setup:

1. Build with Xcode 16.4 toolchain.

2. Only use LLD for ThinLto.

3. Reproducer attached rep 2.zip

4. bazelisk build :Buttons --features=swift.thin_lto --features=thin_lto --features=swift.emit_bc --ios_multi_cpus=arm64

LLVM ERROR: Unsupported stack probing method
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0.      Running pass 'Function Pass Manager' on module 'bazel-out/ios_arm64-fastbuild-ios-arm64-min15.0-applebin_ios-ST-4adaf0076b5c/bin/libNeedleFoundation.a(NonCoreComponent.swift.bc)259720'.
1.      Running pass 'AArch64 Instruction Selection' on function '@"$s16NeedleFoundation16NonCoreComponentC6parentACyxGAA5Scope_p_tcfC"'
LLVM ERROR: Unsupported stack probing method
clang: error: unable to execute command: Abort trap: 6
clang: error: linker command failed due to signal (use -v to see invocation)
Apple clang version 17.0.0 (clang-1700.0.13.5)
Target: arm64-apple-ios15.0
Thread model: posix
InstalledDir: /Applications/Xcode.16.4.0.16F6.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

Author: Chirag Ramani (chiragramani)

When using thin lto with Swift, we see a couple of LLD crashes.

All crashes seen so far are in AArch64 Instruction Selection stages.

Setup:

1. Build with Xcode 16.4 toolchain.

2. Only use LLD for ThinLto.

3. Reproducer attached rep 2.zip

4. bazelisk build :Buttons --features=swift.thin_lto --features=thin_lto --features=swift.emit_bc --ios_multi_cpus=arm64

LLVM ERROR: Unsupported stack probing method
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0.      Running pass 'Function Pass Manager' on module 'bazel-out/ios_arm64-fastbuild-ios-arm64-min15.0-applebin_ios-ST-4adaf0076b5c/bin/libNeedleFoundation.a(NonCoreComponent.swift.bc)259720'.
1.      Running pass 'AArch64 Instruction Selection' on function '@"$s16NeedleFoundation16NonCoreComponentC6parentACyxGAA5Scope_p_tcfC"'

[chiragramani]

cc: @ellishg

[asl]

Likely dup of #95804 – one cannot mix and match LLVM IR produced by downstream Apple clang and mainline LLVM

[cachemeifyoucan]

Correct. There is no defined compatibility between LLVM IR between Apple clang and mainline. It might work if the branch point from apple clang is close enough but there is no guarantee.

This specific error is coming from apple specific stack probing method that is not available in mainline. -fno-stack-check might workaround by disabling the stack probing function.