From 8fcdb6b4fafdf3229f2f2f4b5dd66dc662ee66ec Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 19 Jul 2025 09:45:56 +0200
Subject: [PATCH] CI: add windows-arm runner

---
 .github/workflows/ci.yml |  8 ++++++++
 cargo-miri/src/phases.rs |  8 ++++----
 ci/ci.sh                 | 12 ++++++++----
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 11c0f08deb..1af4438039 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -45,6 +45,8 @@ jobs:
             os: macos-latest
           - host_target: i686-pc-windows-msvc
             os: windows-latest
+          - host_target: aarch64-pc-windows-msvc
+            os: windows-11-arm
     runs-on: ${{ matrix.os }}
     env:
       HOST_TARGET: ${{ matrix.host_target }}
@@ -63,6 +65,12 @@ jobs:
           sudo apt update
           # Install needed packages
           sudo apt install $(echo "libatomic1: zlib1g-dev:" | sed 's/:/:${{ matrix.multiarch }}/g')
+      - name: Install rustup on Windows ARM
+        if: ${{ matrix.os == 'windows-11-arm' }}
+        run: |
+            curl -LOs https://static.rust-lang.org/rustup/dist/aarch64-pc-windows-msvc/rustup-init.exe
+            ./rustup-init.exe -y --no-modify-path
+            echo "$USERPROFILE/.cargo/bin" >> "$GITHUB_PATH"
       - uses: ./.github/workflows/setup
         with:
           toolchain_flags: "--host ${{ matrix.host_target }}"
diff --git a/cargo-miri/src/phases.rs b/cargo-miri/src/phases.rs
index b72b974bdb..efb9053f69 100644
--- a/cargo-miri/src/phases.rs
+++ b/cargo-miri/src/phases.rs
@@ -1,9 +1,9 @@
 //! Implements the various phases of `cargo miri run/test`.
 
 use std::env;
-use std::fs::{self, File};
+use std::fs::File;
 use std::io::BufReader;
-use std::path::{Path, PathBuf};
+use std::path::{self, Path, PathBuf};
 use std::process::Command;
 
 use rustc_version::VersionMeta;
@@ -222,12 +222,12 @@ pub fn phase_cargo_miri(mut args: impl Iterator<Item = String>) {
     // that to be the Miri driver, but acting as rustc, in host mode.
     //
     // In `main`, we need the value of `RUSTC` to distinguish RUSTC_WRAPPER invocations from rustdoc
-    // or TARGET_RUNNER invocations, so we canonicalize it here to make it exceedingly unlikely that
+    // or TARGET_RUNNER invocations, so we make it absolute to make it exceedingly unlikely that
     // there would be a collision with other invocations of cargo-miri (as rustdoc or as runner). We
     // explicitly do this even if RUSTC_STAGE is set, since for these builds we do *not* want the
     // bootstrap `rustc` thing in our way! Instead, we have MIRI_HOST_SYSROOT to use for host
     // builds.
-    cmd.env("RUSTC", fs::canonicalize(find_miri()).unwrap());
+    cmd.env("RUSTC", path::absolute(find_miri()).unwrap());
     // In case we get invoked as RUSTC without the wrapper, let's be a host rustc. This makes no
     // sense for cross-interpretation situations, but without the wrapper, this will use the host
     // sysroot, so asking it to behave like a target build makes even less sense.
diff --git a/ci/ci.sh b/ci/ci.sh
index 5767d17827..b66530e77b 100755
--- a/ci/ci.sh
+++ b/ci/ci.sh
@@ -142,7 +142,6 @@ case $HOST_TARGET in
     # Host
     GC_STRESS=1 MIR_OPT=1 MANY_SEEDS=64 TEST_BENCH=1 CARGO_MIRI_ENV=1 run_tests
     # Extra tier 1
-    MANY_SEEDS=64 TEST_TARGET=i686-unknown-linux-gnu run_tests
     MANY_SEEDS=64 TEST_TARGET=x86_64-apple-darwin run_tests
     MANY_SEEDS=64 TEST_TARGET=x86_64-pc-windows-gnu run_tests
     ;;
@@ -161,8 +160,6 @@ case $HOST_TARGET in
   aarch64-unknown-linux-gnu)
     # Host
     GC_STRESS=1 MIR_OPT=1 MANY_SEEDS=64 TEST_BENCH=1 CARGO_MIRI_ENV=1 run_tests
-    # Extra tier 1 candidate
-    MANY_SEEDS=64 TEST_TARGET=aarch64-pc-windows-msvc run_tests
     # Extra tier 2
     MANY_SEEDS=16 TEST_TARGET=arm-unknown-linux-gnueabi run_tests # 32bit ARM
     MANY_SEEDS=16 TEST_TARGET=aarch64-pc-windows-gnullvm run_tests # gnullvm ABI
@@ -189,13 +186,20 @@ case $HOST_TARGET in
     ;;
   i686-pc-windows-msvc)
     # Host
-    # Without GC_STRESS as this is the slowest runner.
+    # Without GC_STRESS as this is a very slow runner.
     MIR_OPT=1 MANY_SEEDS=64 TEST_BENCH=1 run_tests
     # Extra tier 1
     # We really want to ensure a Linux target works on a Windows host,
     # and a 64bit target works on a 32bit host.
     TEST_TARGET=x86_64-unknown-linux-gnu run_tests
     ;;
+  aarch64-pc-windows-msvc)
+    # Host
+    # Without GC_STRESS as this is a very slow runner.
+    MIR_OPT=1 MANY_SEEDS=64 TEST_BENCH=1 CARGO_MIRI_ENV=1 run_tests
+    # Extra tier 1
+    MANY_SEEDS=64 TEST_TARGET=i686-unknown-linux-gnu run_tests
+    ;;
   *)
     echo "FATAL: unknown host target: $HOST_TARGET"
     exit 1