tests: Test m68k using QEMU

.github/.cspell/project-dictionary.txt

@@ -109,6 +109,7 @@ sltui
 sreg
 srlv
 stbar
+stdarch
 stdcx
 stilp
 stlxp

.github/dependabot.yml

@@ -5,6 +5,7 @@ updates:
       - /
       # crates with [workspace] table are not recognized by the above 'directory: /'
       - /tests/avr
+      # - /tests/m68k # This has a path dependency on a crate that does not exist at checkout that is initialized by the script.
       - /tests/msp430
       - /tests/no-std-qemu
       - /tests/xtensa

.github/workflows/ci.yml

@@ -405,7 +405,7 @@ jobs:
           - stable
           - nightly-2023-08-24 # Rust 1.74, LLVM 17 (oldest version that MaybeUninit register is supported)
           - nightly
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     timeout-minutes: 60
     steps:
       - uses: taiki-e/checkout-action@v1
@@ -435,6 +435,8 @@ jobs:
             apt_packages+=(
               avr-libc
               gcc-avr
+              gcc-m68k-linux-gnu
+              libc6-dev-m68k-cross
               qemu-system-sparc
               simavr
             )
@@ -470,6 +472,13 @@ jobs:
                 | tar xzf - --strip-components 1 -C "${HOME}"/tsim
               printf '%s\n' "${HOME}"/tsim/tsim/linux-x64 >>"${GITHUB_PATH}"
             fi
+            # https://github.com/taiki-e/dockerfiles/pkgs/container/qemu-user
+            retry docker create --name qemu-user ghcr.io/taiki-e/qemu-user
+            mkdir -p -- qemu-user
+            docker cp -- qemu-user:/usr/bin qemu-user/bin
+            docker rm -f -- qemu-user >/dev/null
+            sudo mv -- qemu-user/bin/qemu-* /usr/bin/
+            rm -rf -- ./qemu-user
           elif [[ "${{ matrix.rust }}" == "stable" ]]; then
             retry espup install --targets esp32,esp32s2,esp32s3
           fi

tests/m68k/.cargo/config.toml

@@ -0,0 +1,3 @@
+[target.m68k-unknown-linux-gnu]
+linker = "m68k-linux-gnu-gcc"
+runner = "qemu-m68k -L /usr/m68k-linux-gnu"

tests/m68k/.gitignore

@@ -0,0 +1 @@
+rust-src

tests/m68k/Cargo.toml

@@ -0,0 +1,46 @@
+[package]
+name = "no-core"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[features]
+default = ["isize", "usize", "i8", "u8"]
+# NB: Sync feature list with tools/no-std.sh
+isize = []
+usize = []
+i8 = []
+u8 = []
+i16 = []
+u16 = []
+i32 = []
+u32 = []
+i64 = []
+u64 = []
+
+[dependencies]
+# atomic-maybe-uninit = { path = "../.." }
+
+core = { path = "rust-src/core" }
+paste = "1"
+
+[workspace]
+resolver = "2"
+
+[lints.rust]
+rust_2018_idioms = "warn"
+single_use_lifetimes = "warn"
+# unsafe_op_in_unsafe_fn = "warn" # Set at crate-level instead since https://github.com/rust-lang/rust/pull/100081 is not available on MSRV
+
+[profile.dev]
+codegen-units = 1
+lto = true
+opt-level = "s"
+panic = "abort"
+
+[profile.release]
+codegen-units = 1
+lto = true
+# TODO: panic in cas test with -C opt-level=3
+opt-level = "s"
+panic = "abort"

tests/m68k/build.rs

@@ -0,0 +1 @@
+../../build.rs