user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Rollup merge of #140758 - dpaoliello:armhazard, r=jieyouxu

Browse source 
[win][arm64] Disable MSVC Linker 'Arm Hazard' warning

While trying to get the aarch64-msvc build working correctly (#140136), I observed the following test failure:

From <https://github.com/rust-lang/rust/pull/140136#issuecomment-2848179657>

```
  = note: main.main.d17f5fbe6225cf88-cgu.0.rcgu.o : fatal error LNK1322: cannot avoid potential ARM hazard (Cortex-A53 MPCore processor bug #843419) in section 0x57; please consider using compiler option /Gy if it was not used
```

This is warning of a code sequence that triggers a bug in Cortex-A53 processors: <https://developer.arm.com/documentation/epm048406/latest>

However, since Windows 10 isn't supported on the Cortex-A53, this warning is not required, so it can be suppressed using the undocumented `/arm64hazardfree` flag.
This commit is contained in:
Matthias Krüger 2025-05-08 13:55:45 +02:00 • committed by GitHub
commit 54f1da4486
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 6 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

7
compiler/rustc_target/src/spec/targets/aarch64_pc_windows_msvc.rs
View file

@ -1,10 +1,15 @@
use crate::spec::{Target, TargetMetadata, base};
use crate::spec::{LinkerFlavor, Lld, Target, TargetMetadata, base};
pub(crate) fn target() -> Target {
let mut base = base::windows_msvc::opts();
base.max_atomic_width = Some(128);
base.features = "+v8a,+neon,+fp-armv8".into();
// MSVC emits a warning about code that may trip "Cortex-A53 MPCore processor bug #843419" (see
// https://developer.arm.com/documentation/epm048406/latest) which is sometimes emitted by LLVM.
// Since Arm64 Windows 10+ isn't supported on that processor, it's safe to disable the warning.
base.add_pre_link_args(LinkerFlavor::Msvc(Lld::No), &["/arm64hazardfree"]);
Target {
llvm_target: "aarch64-pc-windows-msvc".into(),
metadata: TargetMetadata {