4 files changed, 21 insertions, 36 deletions
diff --git a/compiler/rustc_codegen_ssa/messages.ftl b/compiler/rustc_codegen_ssa/messages.ftl
index 95912b01600..a33c0aa5834 100644
--- a/compiler/rustc_codegen_ssa/messages.ftl
+++ b/compiler/rustc_codegen_ssa/messages.ftl
@@ -391,8 +391,6 @@ codegen_ssa_unknown_atomic_ordering = unknown ordering in atomic intrinsic
 
 codegen_ssa_unknown_reuse_kind = unknown cgu-reuse-kind `{$kind}` specified
 
-codegen_ssa_unsupported_arch = unsupported arch `{$arch}` for os `{$os}`
-
 codegen_ssa_unsupported_instruction_set = target does not support `#[instruction_set]`
 
 codegen_ssa_unsupported_link_self_contained = option `-C link-self-contained` is not supported on this target
diff --git a/compiler/rustc_codegen_ssa/src/back/apple.rs b/compiler/rustc_codegen_ssa/src/back/apple.rs
index bfa7635a869..24995be6f94 100644
--- a/compiler/rustc_codegen_ssa/src/back/apple.rs
+++ b/compiler/rustc_codegen_ssa/src/back/apple.rs
@@ -11,6 +11,24 @@ use crate::errors::AppleDeploymentTarget;
 #[cfg(test)]
 mod tests;
 
+/// The canonical name of the desired SDK for a given target.
+pub(super) fn sdk_name(target: &Target) -> &'static str {
+    match (&*target.os, &*target.abi) {
+        ("macos", "") => "MacOSX",
+        ("ios", "") => "iPhoneOS",
+        ("ios", "sim") => "iPhoneSimulator",
+        // Mac Catalyst uses the macOS SDK
+        ("ios", "macabi") => "MacOSX",
+        ("tvos", "") => "AppleTVOS",
+        ("tvos", "sim") => "AppleTVSimulator",
+        ("visionos", "") => "XROS",
+        ("visionos", "sim") => "XRSimulator",
+        ("watchos", "") => "WatchOS",
+        ("watchos", "sim") => "WatchSimulator",
+        (os, abi) => unreachable!("invalid os '{os}' / abi '{abi}' combination for Apple target"),
+    }
+}
+
 pub(super) fn macho_platform(target: &Target) -> u32 {
     match (&*target.os, &*target.abi) {
         ("macos", _) => object::macho::PLATFORM_MACOS,
diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 74597f6263d..776f381ded4 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -3201,9 +3201,7 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
 }
 
 fn add_apple_sdk(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) -> Option<PathBuf> {
-    let arch = &sess.target.arch;
     let os = &sess.target.os;
-    let llvm_target = &sess.target.llvm_target;
     if sess.target.vendor != "apple"
         || !matches!(os.as_ref(), "ios" | "tvos" | "watchos" | "visionos" | "macos")
         || !matches!(flavor, LinkerFlavor::Darwin(..))
@@ -3215,31 +3213,9 @@ fn add_apple_sdk(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) ->
         return None;
     }
 
-    let sdk_name = match (arch.as_ref(), os.as_ref()) {
-        ("aarch64", "tvos") if llvm_target.ends_with("-simulator") => "appletvsimulator",
-        ("aarch64", "tvos") => "appletvos",
-        ("x86_64", "tvos") => "appletvsimulator",
-        ("arm", "ios") => "iphoneos",
-        ("aarch64", "ios") if llvm_target.contains("macabi") => "macosx",
-        ("aarch64", "ios") if llvm_target.ends_with("-simulator") => "iphonesimulator",
-        ("aarch64", "ios") => "iphoneos",
-        ("x86", "ios") => "iphonesimulator",
-        ("x86_64", "ios") if llvm_target.contains("macabi") => "macosx",
-        ("x86_64", "ios") => "iphonesimulator",
-        ("x86_64", "watchos") => "watchsimulator",
-        ("arm64_32", "watchos") => "watchos",
-        ("aarch64", "watchos") if llvm_target.ends_with("-simulator") => "watchsimulator",
-        ("aarch64", "watchos") => "watchos",
-        ("aarch64", "visionos") if llvm_target.ends_with("-simulator") => "xrsimulator",
-        ("aarch64", "visionos") => "xros",
-        ("arm", "watchos") => "watchos",
-        (_, "macos") => "macosx",
-        _ => {
-            sess.dcx().emit_err(errors::UnsupportedArch { arch, os });
-            return None;
-        }
-    };
-    let sdk_root = match get_apple_sdk_root(sdk_name) {
+    let sdk_name = apple::sdk_name(&sess.target).to_lowercase();
+
+    let sdk_root = match get_apple_sdk_root(&sdk_name) {
         Ok(s) => s,
         Err(e) => {
             sess.dcx().emit_err(e);
diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs
index 0b7cad0c2fd..9c4c205dfe5 100644
--- a/compiler/rustc_codegen_ssa/src/errors.rs
+++ b/compiler/rustc_codegen_ssa/src/errors.rs
@@ -739,13 +739,6 @@ pub enum ExtractBundledLibsError<'a> {
 }
 
 #[derive(Diagnostic)]
-#[diag(codegen_ssa_unsupported_arch)]
-pub(crate) struct UnsupportedArch<'a> {
-    pub arch: &'a str,
-    pub os: &'a str,
-}
-
-#[derive(Diagnostic)]
 pub(crate) enum AppleDeploymentTarget {
     #[diag(codegen_ssa_apple_deployment_target_invalid)]
     Invalid { env_var: &'static str, error: ParseIntError },