1 files changed, 91 insertions, 0 deletions
diff --git a/vendor/portable-atomic/src/imp/atomic128/detect/aarch64_fuchsia.rs b/vendor/portable-atomic/src/imp/atomic128/detect/aarch64_fuchsia.rs
new file mode 100644
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+++ b/vendor/portable-atomic/src/imp/atomic128/detect/aarch64_fuchsia.rs
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+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+// Run-time feature detection on aarch64 Fuchsia by using zx_system_get_features.
+//
+// As of nightly-2023-01-23, is_aarch64_feature_detected doesn't support run-time detection on Fuchsia.
+// https://github.com/rust-lang/stdarch/blob/a0c30f3e3c75adcd6ee7efc94014ebcead61c507/crates/std_detect/src/detect/mod.rs
+//
+// Refs:
+// - https://fuchsia.dev/fuchsia-src/reference/syscalls/system_get_features
+// - https://github.com/llvm/llvm-project/commit/4e731abc55681751b5d736b613f7720e50eb1ad4
+
+include!("common.rs");
+
+#[allow(non_camel_case_types)]
+mod ffi {
+    // https://fuchsia.googlesource.com/fuchsia/+/refs/heads/main/zircon/system/public/zircon/types.h
+    pub(crate) type zx_status_t = i32;
+
+    // https://fuchsia.googlesource.com/fuchsia/+/refs/heads/main/zircon/system/public/zircon/errors.h
+    pub(crate) const ZX_OK: zx_status_t = 0;
+    // https://fuchsia.googlesource.com/fuchsia/+/refs/heads/main/zircon/system/public/zircon/features.h
+    pub(crate) const ZX_FEATURE_KIND_CPU: u32 = 0;
+    pub(crate) const ZX_ARM64_FEATURE_ISA_ATOMICS: u32 = 1 << 8;
+
+    #[link(name = "zircon")]
+    extern "C" {
+        // https://fuchsia.dev/fuchsia-src/reference/syscalls/system_get_features
+        pub(crate) fn zx_system_get_features(kind: u32, features: *mut u32) -> zx_status_t;
+    }
+}
+
+fn zx_system_get_features(kind: u32) -> u32 {
+    let mut out = 0_u32;
+    // SAFETY: the pointer is valid because we got it from a reference.
+    let res = unsafe { ffi::zx_system_get_features(kind, &mut out) };
+    if res != ffi::ZX_OK {
+        return 0;
+    }
+    out
+}
+
+#[cold]
+fn _detect(info: &mut CpuInfo) {
+    let features = zx_system_get_features(ffi::ZX_FEATURE_KIND_CPU);
+    if features & ffi::ZX_ARM64_FEATURE_ISA_ATOMICS != 0 {
+        info.set(CpuInfo::HAS_LSE);
+    }
+}
+
+#[allow(
+    clippy::alloc_instead_of_core,
+    clippy::std_instead_of_alloc,
+    clippy::std_instead_of_core,
+    clippy::undocumented_unsafe_blocks,
+    clippy::wildcard_imports
+)]
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_fuchsia() {
+        let features = zx_system_get_features(ffi::ZX_FEATURE_KIND_CPU);
+        assert_ne!(features, 0);
+        std::eprintln!("features: {:b}", features);
+    }
+
+    // Static assertions for FFI bindings.
+    // This checks that FFI bindings defined in this crate and FFI bindings
+    // generated for the platform's latest header file using bindgen have
+    // compatible signatures (or the same values if constants).
+    // Since this is static assertion, we can detect problems with
+    // `cargo check --tests --target <target>` run in CI (via TESTS=1 build.sh)
+    // without actually running tests on these platforms.
+    // See also tools/codegen/src/ffi.rs.
+    // TODO(codegen): auto-generate this test
+    #[allow(
+        clippy::cast_possible_wrap,
+        clippy::cast_sign_loss,
+        clippy::cast_possible_truncation,
+        clippy::no_effect_underscore_binding
+    )]
+    const _: fn() = || {
+        use test_helper::sys;
+        // TODO(codegen): zx_system_get_features
+        let _: ffi::zx_status_t = 0 as sys::zx_status_t;
+        static_assert!(ffi::ZX_OK == sys::ZX_OK as ffi::zx_status_t);
+        static_assert!(ffi::ZX_FEATURE_KIND_CPU == sys::ZX_FEATURE_KIND_CPU);
+        static_assert!(ffi::ZX_ARM64_FEATURE_ISA_ATOMICS == sys::ZX_ARM64_FEATURE_ISA_ATOMICS);
+    };
+}