Use a default check for the "env" variable in apple_sdk_name (#1605)

Author: aomahony-saronic

src/target/apple.rs

@@ -3,16 +3,20 @@ use super::TargetInfo;
 impl TargetInfo<'_> {
     pub(crate) fn apple_sdk_name(&self) -> &'static str {
         match (self.os, self.env) {
-            ("macos", "") => "macosx",
-            ("ios", "") => "iphoneos",
+            // The target_env variable, as written here:
+            // https://doc.rust-lang.org/reference/conditional-compilation.html#target_env
+            // is only really used for disambiguation, so we use a "default" case instead of
+            // checking for a blank string.
+            ("macos", _) => "macosx",
             ("ios", "sim") => "iphonesimulator",
             ("ios", "macabi") => "macosx",
-            ("tvos", "") => "appletvos",
+            ("ios", _) => "iphoneos",
             ("tvos", "sim") => "appletvsimulator",
-            ("watchos", "") => "watchos",
+            ("tvos", _) => "appletvos",
             ("watchos", "sim") => "watchsimulator",
-            ("visionos", "") => "xros",
+            ("watchos", _) => "watchos",
             ("visionos", "sim") => "xrsimulator",
+            ("visionos", _) => "xros",
             (os, _) => panic!("invalid Apple target OS {}", os),
         }
     }
@@ -31,18 +35,22 @@ impl TargetInfo<'_> {
         // https://clang.llvm.org/docs/AttributeReference.html#availability
         // https://gcc.gnu.org/onlinedocs/gcc/Darwin-Options.html#index-mmacosx-version-min
         match (self.os, self.env) {
-            ("macos", "") => format!("-mmacosx-version-min={min_version}"),
-            ("ios", "") => format!("-miphoneos-version-min={min_version}"),
+            // The target_env variable, as written here:
+            // https://doc.rust-lang.org/reference/conditional-compilation.html#target_env
+            // is only really used for disambiguation, so we use a "default" case instead of
+            // checking for a blank string.
+            ("macos", _) => format!("-mmacosx-version-min={min_version}"),
             ("ios", "sim") => format!("-mios-simulator-version-min={min_version}"),
             ("ios", "macabi") => format!("-mtargetos=ios{min_version}-macabi"),
-            ("tvos", "") => format!("-mappletvos-version-min={min_version}"),
+            ("ios", _) => format!("-miphoneos-version-min={min_version}"),
             ("tvos", "sim") => format!("-mappletvsimulator-version-min={min_version}"),
-            ("watchos", "") => format!("-mwatchos-version-min={min_version}"),
+            ("tvos", _) => format!("-mappletvos-version-min={min_version}"),
             ("watchos", "sim") => format!("-mwatchsimulator-version-min={min_version}"),
+            ("watchos", _) => format!("-mwatchos-version-min={min_version}"),
             // `-mxros-version-min` does not exist
             // https://github.com/llvm/llvm-project/issues/88271
-            ("visionos", "") => format!("-mtargetos=xros{min_version}"),
             ("visionos", "sim") => format!("-mtargetos=xros{min_version}-simulator"),
+            ("visionos", _) => format!("-mtargetos=xros{min_version}"),
             (os, _) => panic!("invalid Apple target OS {}", os),
         }
     }