detect: Make macOS implementation available on other Apple targets

.github/workflows/ci.yml

@@ -126,7 +126,10 @@ jobs:
             os: windows-latest
           - rust: nightly
             target: aarch64-apple-darwin
-            os: macos-14 # AArch64
+            os: macos-latest # AArch64
+          - rust: nightly
+            target: aarch64-apple-ios-macabi
+            os: macos-latest # AArch64
           - rust: '1.59' # LLVM 13
             target: aarch64-unknown-linux-gnu
           # - rust: '1.64' # LLVM 14

src/imp/atomic128/README.md

@@ -41,8 +41,8 @@ Here is the table of targets that support run-time CPU feature detection and the
 | aarch64     | android              | getauxval       | all      | Enabled by default |
 | aarch64     | freebsd              | elf_aux_info    | lse, lse2 | Enabled by default |
 | aarch64     | netbsd               | sysctl          | all      | Enabled by default |
-| aarch64     | openbsd              | sysctl          | all      | Enabled by default |
-| aarch64     | macos                | sysctl          | all      | Currently only used in tests because FEAT_LSE and FEAT_LSE2 are always available at compile-time. |
+| aarch64     | openbsd              | sysctlbyname    | all      | Enabled by default |
+| aarch64     | macos/ios/tvos/watchos/visionos | sysctlbyname    | all      | Currently only used in tests because FEAT_LSE and FEAT_LSE2 are always available at compile-time. |
 | aarch64     | windows              | IsProcessorFeaturePresent | lse | Enabled by default |
 | aarch64     | fuchsia              | zx_system_get_features | lse | Enabled by default |
 | powerpc64   | linux                | getauxval       | all      | Disabled by default |

src/imp/atomic128/aarch64.rs

@@ -141,9 +141,15 @@ mod detect_aa64reg;
 // mod detect_auxv;
 #[cfg(test)]
 #[cfg(not(portable_atomic_no_outline_atomics))]
-#[cfg(target_os = "macos")]
-#[path = "detect/aarch64_macos.rs"]
-mod detect_macos;
+#[cfg(any(
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "tvos",
+    target_os = "watchos",
+    target_os = "visionos",
+))]
+#[path = "detect/aarch64_apple.rs"]
+mod detect_apple;
 
 #[cfg(not(portable_atomic_no_asm))]
 use core::arch::asm;

src/imp/atomic128/detect/aarch64_aa64reg.rs

@@ -18,7 +18,7 @@ Supported platforms:
   https://github.com/torvalds/linux/commit/77c97b4ee21290f5f083173d957843b615abbff2
 - FreeBSD 12.0+ (emulate mrs instruction)
   https://github.com/freebsd/freebsd-src/commit/398810619cb32abf349f8de23f29510b2ee0839b
-- NetBSD 9.0+ (through sysctl)
+- NetBSD 9.0+ (through sysctl/sysctlbyname)
   https://github.com/NetBSD/src/commit/0e9d25528729f7fea53e78275d1bc5039dfe8ffb
 - OpenBSD 7.1+ (through sysctl)
   https://github.com/openbsd/src/commit/d335af936b9d7dd9cf655cae1ce19560c45de6c8

src/imp/atomic128/detect/aarch64_macos.rs → src/imp/atomic128/detect/aarch64_apple.rs

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 
 /*
-Run-time CPU feature detection on AArch64 macOS by using sysctl.
+Run-time CPU feature detection on AArch64 Apple targets by using sysctlbyname.
 
 This module is currently only enabled on tests because AArch64 macOS always supports FEAT_LSE and FEAT_LSE2.
 https://github.com/llvm/llvm-project/blob/llvmorg-18.1.2/llvm/include/llvm/TargetParser/AArch64TargetParser.h#L728
@@ -12,9 +12,10 @@ M4 is Armv9.2 and it doesn't support FEAT_LSE128/FEAT_LRCPC3.
 
 Refs: https://developer.apple.com/documentation/kernel/1387446-sysctlbyname/determining_instruction_set_characteristics
 
-Note that iOS doesn't support sysctl:
+TODO: non-macOS targets doesn't always supports FEAT_LSE2, but sysctl on them on app stores is...?
 - https://developer.apple.com/forums/thread/9440
 - https://nabla-c0d3.github.io/blog/2015/06/16/ios9-security-privacy
+- https://github.com/rust-lang/stdarch/pull/1636
 */
 
 include!("common.rs");
@@ -136,7 +137,14 @@ mod tests {
         clippy::no_effect_underscore_binding
     )]
     const _: fn() = || {
-        use test_helper::{libc, sys};
+        use test_helper::libc;
+        #[cfg(not(any(
+            target_os = "ios",
+            target_os = "tvos",
+            target_os = "watchos",
+            target_os = "visionos",
+        )))]
+        use test_helper::sys;
         let mut _sysctlbyname: unsafe extern "C" fn(
             *const ffi::c_char,
             *mut ffi::c_void,
@@ -145,6 +153,14 @@ mod tests {
             ffi::c_size_t,
         ) -> ffi::c_int = ffi::sysctlbyname;
         _sysctlbyname = libc::sysctlbyname;
-        _sysctlbyname = sys::sysctlbyname;
+        #[cfg(not(any(
+            target_os = "ios",
+            target_os = "tvos",
+            target_os = "watchos",
+            target_os = "visionos",
+        )))] // TODO
+        {
+            _sysctlbyname = sys::sysctlbyname;
+        }
     };
 }

src/imp/atomic128/detect/common.rs

@@ -148,23 +148,48 @@ mod c_types {
     // Hexagon https://lists.llvm.org/pipermail/llvm-dev/attachments/20190916/21516a52/attachment-0001.pdf
     // AIX https://www.ibm.com/docs/en/xl-c-aix/13.1.2?topic=descriptions-qchars
     // z/OS https://www.ibm.com/docs/en/zos/2.5.0?topic=specifiers-character-types
-    // (macOS is currently the only Apple target that uses this module, and Windows currently doesn't use this module)
-    #[cfg(not(target_os = "macos"))]
+    // (Windows currently doesn't use this module)
+    #[cfg(not(any(
+        target_os = "macos",
+        target_os = "ios",
+        target_os = "tvos",
+        target_os = "watchos",
+        target_os = "visionos",
+    )))]
     pub(crate) type c_char = u8;
     // c_char is i8 on all Apple targets
-    #[cfg(target_os = "macos")]
+    #[cfg(any(
+        target_os = "macos",
+        target_os = "ios",
+        target_os = "tvos",
+        target_os = "watchos",
+        target_os = "visionos",
+    ))]
     pub(crate) type c_char = i8;
 
     // Static assertions for C type definitions.
     #[cfg(test)]
     const _: fn() = || {
-        use test_helper::{libc, sys};
+        use test_helper::libc;
+        #[cfg(not(any(
+            target_os = "ios",
+            target_os = "tvos",
+            target_os = "watchos",
+            target_os = "visionos",
+        )))]
+        use test_helper::sys;
         let _: c_int = 0 as std::os::raw::c_int;
         let _: c_uint = 0 as std::os::raw::c_uint;
         let _: c_long = 0 as std::os::raw::c_long;
         let _: c_ulong = 0 as std::os::raw::c_ulong;
         let _: c_size_t = 0 as libc::size_t; // std::os::raw::c_size_t is unstable
         let _: c_char = 0 as std::os::raw::c_char;
+        #[cfg(not(any(
+            target_os = "ios",
+            target_os = "tvos",
+            target_os = "watchos",
+            target_os = "visionos",
+        )))] // TODO
         let _: c_char = 0 as sys::c_char;
     };
 }