Move Mach-O platform information to rustc_codegen_ssa::back::apple

To align with the general decision to have this sort of information
there instead.

Also use the visionOS values added in newer `object` release.

2 files changed, 17 insertions, 2 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/apple.rs b/compiler/rustc_codegen_ssa/src/back/apple.rs
index 939ce2e1a03..23460ae9e1e 100644
--- a/compiler/rustc_codegen_ssa/src/back/apple.rs
+++ b/compiler/rustc_codegen_ssa/src/back/apple.rs
@@ -7,6 +7,22 @@ use rustc_target::spec::Target;
 #[cfg(test)]
 mod tests;
 
+pub(super) fn macho_platform(target: &Target) -> u32 {
+    match (&*target.os, &*target.abi) {
+        ("macos", _) => object::macho::PLATFORM_MACOS,
+        ("ios", "macabi") => object::macho::PLATFORM_MACCATALYST,
+        ("ios", "sim") => object::macho::PLATFORM_IOSSIMULATOR,
+        ("ios", _) => object::macho::PLATFORM_IOS,
+        ("watchos", "sim") => object::macho::PLATFORM_WATCHOSSIMULATOR,
+        ("watchos", _) => object::macho::PLATFORM_WATCHOS,
+        ("tvos", "sim") => object::macho::PLATFORM_TVOSSIMULATOR,
+        ("tvos", _) => object::macho::PLATFORM_TVOS,
+        ("visionos", "sim") => object::macho::PLATFORM_XROSSIMULATOR,
+        ("visionos", _) => object::macho::PLATFORM_XROS,
+        _ => unreachable!("tried to get Mach-O platform for non-Apple target"),
+    }
+}
+
 /// Deployment target or SDK version.
 ///
 /// The size of the numbers in here are limited by Mach-O's `LC_BUILD_VERSION`.
diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs
index 1b11fe661db..5544f8d40c9 100644
--- a/compiler/rustc_codegen_ssa/src/back/metadata.rs
+++ b/compiler/rustc_codegen_ssa/src/back/metadata.rs
@@ -402,8 +402,7 @@ fn macho_object_build_version_for_target(sess: &Session) -> object::write::MachO
         (major << 16) | (minor << 8) | patch
     }
 
-    let platform =
-        rustc_target::spec::current_apple_platform(&sess.target).expect("unknown Apple target OS");
+    let platform = apple::macho_platform(&sess.target);
     let min_os = apple::deployment_target(sess);
 
     let mut build_version = object::write::MachOBuildVersion::default();