Set the default deployment target for Macos ARM64 to 11.0.

11.0 (Big Sur) is the first version which supports ARM64 so we use that as default.

Author: hkratz

compiler/rustc_target/src/spec/apple_base.rs

@@ -13,8 +13,10 @@ pub fn opts(os: &str) -> TargetOptions {
  // warnings about the usage of ELF TLS.
  //
  // Here we detect what version is being requested, defaulting to 10.7. ELF
- // TLS is flagged as enabled if it looks to be supported.
- let version = macos_deployment_target();
+ // TLS is flagged as enabled if it looks to be supported. The architecture
+ // only matters for default deployment target which is 11.0 for ARM64 and
+ // 10.7 for everything else.
+ let has_elf_tls = macos_deployment_target("x86_64") >= (10, 7);
 
  TargetOptions {
  os: os.to_string(),
@@ -31,7 +33,7 @@ pub fn opts(os: &str) -> TargetOptions {
  has_rpath: true,
  dll_suffix: ".dylib".to_string(),
  archive_format: "darwin".to_string(),
- has_elf_tls: version >= (10, 7),
+ has_elf_tls,
  abi_return_struct_as_int: true,
  emit_debug_gdb_scripts: false,
  eh_frame_header: false,
@@ -63,12 +65,17 @@ fn deployment_target(var_name: &str) -> Option<(u32, u32)> {
  .and_then(|(a, b)| a.parse::<u32>().and_then(|a| b.parse::<u32>().map(|b| (a, b))).ok())
 }
 
-fn macos_deployment_target() -> (u32, u32) {
- deployment_target("MACOSX_DEPLOYMENT_TARGET").unwrap_or((10, 7))
+fn macos_default_deployment_target(arch: &str) -> (u32, u32) {
+ if arch == "arm64" { (11, 0) } else { (10, 7) }
+}
+
+fn macos_deployment_target(arch: &str) -> (u32, u32) {
+ deployment_target("MACOSX_DEPLOYMENT_TARGET")
+ .unwrap_or_else(|| macos_default_deployment_target(arch))
 }
 
 pub fn macos_llvm_target(arch: &str) -> String {
- let (major, minor) = macos_deployment_target();
+ let (major, minor) = macos_deployment_target(arch);
  format!("{}-apple-macosx{}.{}.0", arch, major, minor)
 }