gha: test cross-compilation to other arches

.github/workflows/rust.yml

@@ -57,6 +57,40 @@ jobs:
  toolchain: ${{ env.RUST_MSRV }}
  - run: cargo check --workspace --all-features --all-targets
 
+ check-cross:
+ strategy:
+ fail-fast: false
+ matrix:
+ target:
+ - x86_64-unknown-linux-musl
+ - aarch64-unknown-linux-musl
+ - arm-unknown-linux-gnueabi
+ - arm-unknown-linux-gnueabihf
+ - armv7-unknown-linux-gnueabihf
+ - i686-unknown-linux-gnu
+ - loongarch64-unknown-linux-gnu
+ - loongarch64-unknown-linux-musl
+ - powerpc-unknown-linux-gnu
+ - powerpc64-unknown-linux-gnu
+ - powerpc64le-unknown-linux-gnu
+ - riscv64gc-unknown-linux-gnu
+ - sparc64-unknown-linux-gnu
+ - s390x-unknown-linux-gnu
+ name: cargo check (${{ matrix.target }})
+ runs-on: ubuntu-latest
+ steps:
+ - uses: actions/checkout@v4
+ - uses: dtolnay/rust-toolchain@stable
+ with:
+ # TODO: Should we use MSRV for this?
+ targets: ${{ matrix.target }}
+ - name: cargo check --target=${{ matrix.target }}
+ run: >-
+ cargo check --target=${{ matrix.target }} --workspace --all-features --all-targets
+ - name: cargo build --target=${{ matrix.target }}
+ run: >-
+ cargo build --target=${{ matrix.target }} --release --all-features
+
  rustdoc:
  name: cargo doc
  runs-on: ubuntu-latest
@@ -132,6 +166,7 @@ jobs:
  needs:
  - check
  - check-msrv
+ - check-cross
  - rustdoc
  - test
  - examples
@@ -155,6 +190,7 @@ jobs:
  needs:
  - check
  - check-msrv
+ - check-cross
  - rustdoc
  - test
  - examples

CHANGELOG.md

@@ -15,6 +15,14 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - python bindings: add `Root.creat_raw` to create a new file and wrap it in a
  raw `WrappedFd` (os opposed to `Root.creat` which returns an `os.fdopen`).
 
+### Fixes ###
+- multiarch: we now build correctly on 32-bit architectures as well as
+ architectures that have unsigned char. We also have CI jobs that verify that
+ builds work on a fairly large number of architectures (all relevant tier-1
+ and tier-2-with-host-tools architectures). If there is an architecture you
+ would like us to add to the build matrix and it is well-supported by `rustc`,
+ feel free to open an issue or PR!
+
 ### Changed ###
 - syscalls: switch to rustix for most of our syscall wrappers to simplify how
  much code we have for wrapper raw syscalls. This also lets us build on

Makefile

@@ -30,8 +30,8 @@ target/debug: $(SRC_FILES)
  # For some reason, --crate-types needs separate invocations. We can't use
  # #![crate_type] unfortunately, as using it with #![cfg_attr] has been
  # deprecated. <https://github.com/rust-lang/rust/issues/91632>
- $(CARGO) $(CARGO_FLAGS) rustc --crate-type=cdylib $(RUSTC_FLAGS)
- $(CARGO) $(CARGO_FLAGS) rustc --crate-type=staticlib $(RUSTC_FLAGS)
+ $(CARGO) rustc $(CARGO_FLAGS) --crate-type=cdylib $(RUSTC_FLAGS)
+ $(CARGO) rustc $(CARGO_FLAGS) --crate-type=staticlib $(RUSTC_FLAGS)
 
 .PHONY: release
 release: target/release
@@ -40,8 +40,8 @@ target/release: $(SRC_FILES)
  # For some reason, --crate-types needs separate invocations. We can't use
  # #![crate_type] unfortunately, as using it with #![cfg_attr] has been
  # deprecated. <https://github.com/rust-lang/rust/issues/91632>
- $(CARGO) $(CARGO_FLAGS) rustc --release --crate-type=cdylib $(RUSTC_FLAGS)
- $(CARGO) $(CARGO_FLAGS) rustc --release --crate-type=staticlib $(RUSTC_FLAGS)
+ $(CARGO) rustc $(CARGO_FLAGS) --release --crate-type=cdylib $(RUSTC_FLAGS)
+ $(CARGO) rustc $(CARGO_FLAGS) --release --crate-type=staticlib $(RUSTC_FLAGS)
 
 .PHONY: smoke-test
 smoke-test:
@@ -58,7 +58,7 @@ lint: lint-rust
 lint-rust:
  $(CARGO_NIGHTLY) fmt --all -- --check
  $(CARGO) clippy --all-features --all-targets
- $(CARGO) check --all-features --all-targets
+ $(CARGO) check $(CARGO_FLAGS) --all-features --all-targets
 
 .PHONY: test-rust-doctest
 test-rust-doctest:

src/flags.rs

@@ -106,6 +106,7 @@ bitflags! {
  const O_SYNC = libc::O_SYNC;
  const O_ASYNC = libc::O_ASYNC;
  const O_DSYNC = libc::O_DSYNC;
+ #[cfg(not(target_env = "musl"))] // musl doesn't provide FSYNC
  const O_FSYNC = libc::O_FSYNC;
  const O_RSYNC = libc::O_RSYNC;
  const O_DIRECT = libc::O_DIRECT;

src/utils/fd.rs

@@ -43,21 +43,22 @@ impl Metadata {
  }
 }
 
+#[allow(clippy::useless_conversion)] // 32-bit arches
 impl MetadataExt for Metadata {
  fn dev(&self) -> u64 {
- self.0.st_dev
+ self.0.st_dev.into()
  }
 
  fn ino(&self) -> u64 {
- self.0.st_ino
+ self.0.st_ino.into()
  }
 
  fn mode(&self) -> u32 {
  self.0.st_mode
  }
 
  fn nlink(&self) -> u64 {
- self.0.st_nlink
+ self.0.st_nlink.into()
  }
 
  fn uid(&self) -> u32 {
@@ -69,7 +70,7 @@ impl MetadataExt for Metadata {
  }
 
  fn rdev(&self) -> u64 {
- self.0.st_rdev
+ self.0.st_rdev.into()
  }
 
  fn size(&self) -> u64 {
@@ -174,9 +175,9 @@ fn proc_subpath<Fd: AsRawFd>(fd: Fd) -> Result<String, Error> {
 /// [kcommit-a481f4d91783]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a481f4d917835cad86701fc0d1e620c74bb5cd5f
 // TODO: Remove the explicit size once generic_arg_infer is stable.
 // <https://github.com/rust-lang/rust/issues/85077>
-const DANGEROUS_FILESYSTEMS: [i64; 2] = [
- libc::PROC_SUPER_MAGIC, // procfs
- 0x5a3c_69f0, // apparmorfs
+const DANGEROUS_FILESYSTEMS: [rustix_fs::FsWord; 2] = [
+ rustix_fs::PROC_SUPER_MAGIC, // procfs
+ 0x5a3c_69f0,  // apparmorfs
 ];
 
 impl<Fd: AsFd> FdExt for Fd {