Recognize MacCatalyst as a superset of iOS

src/libraries/System.Private.CoreLib/src/System/OperatingSystem.cs

@@ -3,12 +3,13 @@
 
 using System.Diagnostics;
 using System.Runtime.Serialization;
+using System.Runtime.Versioning;
 
 namespace System
 {
  public sealed class OperatingSystem : ISerializable, ICloneable
  {
-#if TARGET_UNIX && !TARGET_OSX
+#if TARGET_UNIX && !TARGET_OSX && !TARGET_MACCATALYST && !TARGET_IOS
  private static readonly string s_osPlatformName = Interop.Sys.GetUnixName();
 #endif
 
@@ -101,6 +102,10 @@ public static bool IsOSPlatform(string platform)
  return platform.Equals("WINDOWS", StringComparison.OrdinalIgnoreCase);
 #elif TARGET_OSX
  return platform.Equals("OSX", StringComparison.OrdinalIgnoreCase) || platform.Equals("MACOS", StringComparison.OrdinalIgnoreCase);
+#elif TARGET_MACCATALYST
+ return platform.Equals("MACCATALYST", StringComparison.OrdinalIgnoreCase) || platform.Equals("IOS", StringComparison.OrdinalIgnoreCase);
+#elif TARGET_IOS
+ return platform.Equals("IOS", StringComparison.OrdinalIgnoreCase);
 #elif TARGET_UNIX
  return platform.Equals(s_osPlatformName, StringComparison.OrdinalIgnoreCase);
 #else
@@ -172,18 +177,20 @@ public static bool IsAndroidVersionAtLeast(int major, int minor = 0, int build =
  => IsAndroid() && IsOSVersionAtLeast(major, minor, build, revision);
 
  /// <summary>
- /// Indicates whether the current application is running on iOS.
+ /// Indicates whether the current application is running on iOS or MacCatalyst.
  /// </summary>
+ [SupportedOSPlatformGuard("maccatalyst")]
  public static bool IsIOS() =>
-#if TARGET_IOS
+#if TARGET_IOS || TARGET_MACCATALYST
  true;
 #else
  false;
 #endif
 
  /// <summary>
- /// Check for the iOS version (returned by 'libobjc.get_operatingSystemVersion') with a >= version comparison. Used to guard APIs that were added in the given iOS release.
+ /// Check for the iOS/MacCatalyst version (returned by 'libobjc.get_operatingSystemVersion') with a >= version comparison. Used to guard APIs that were added in the given iOS release.
  /// </summary>
+ [SupportedOSPlatformGuard("maccatalyst")]
  public static bool IsIOSVersionAtLeast(int major, int minor = 0, int build = 0)
  => IsIOS() && IsOSVersionAtLeast(major, minor, build, 0);
 

src/libraries/System.Runtime.Extensions/tests/System/OperatingSystemTests.cs

@@ -132,6 +132,23 @@ public static void OSX_Is_Treated_as_macOS()
  [Fact, PlatformSpecific(TestPlatforms.MacCatalyst)]
  public static void TestIsOSVersionAtLeast_MacCatalyst() => TestIsOSVersionAtLeast("MacCatalyst");
 
+ [Fact, PlatformSpecific(TestPlatforms.MacCatalyst)]
+ public static void MacCatalyst_Is_Also_iOS()
+ {
+ Assert.True(OperatingSystem.IsOSPlatform("IOS"));
+ Assert.True(OperatingSystem.IsIOS());
+
+ AssertVersionChecks(true, (major, minor, build, revision) => OperatingSystem.IsOSPlatformVersionAtLeast("IOS", major, minor, build, revision));
+ AssertVersionChecks(true, (major, minor, build) => OperatingSystem.IsOSPlatformVersionAtLeast("IOS", major, minor, build));
+ }
+
+ [Fact, PlatformSpecific(TestPlatforms.iOS)]
+ public static void IOS_Is_Not_Also_MacCatalyst()
+ {
+ Assert.False(OperatingSystem.IsOSPlatform("MacCatalyst"));
+ Assert.False(OperatingSystem.IsMacCatalyst());
+ }
+
  [Fact, PlatformSpecific(TestPlatforms.tvOS)]
  public static void TestIsOSPlatform_TvOS() => TestIsOSPlatform("tvOS", OperatingSystem.IsTvOS);
 
@@ -146,13 +163,13 @@ public static void OSX_Is_Treated_as_macOS()
 
  private static void TestIsOSPlatform(string currentOSName, Func<bool> currentOSCheck)
  {
- foreach (string platfromName in AllKnownPlatformNames)
+ foreach (string platformName in AllKnownPlatformNames)
  {
- bool expected = currentOSName.Equals(platfromName, StringComparison.OrdinalIgnoreCase);
+ bool expected = currentOSName.Equals(platformName, StringComparison.OrdinalIgnoreCase);
 
- Assert.Equal(expected, OperatingSystem.IsOSPlatform(platfromName));
- Assert.Equal(expected, OperatingSystem.IsOSPlatform(platfromName.ToUpper()));
- Assert.Equal(expected, OperatingSystem.IsOSPlatform(platfromName.ToLower()));
+ Assert.Equal(expected, OperatingSystem.IsOSPlatform(platformName));
+ Assert.Equal(expected, OperatingSystem.IsOSPlatform(platformName.ToUpper()));
+ Assert.Equal(expected, OperatingSystem.IsOSPlatform(platformName.ToLower()));
  }
 
  Assert.True(currentOSCheck());
@@ -176,13 +193,13 @@ private static void TestIsOSPlatform(string currentOSName, Func<bool> currentOSC
 
  private static void TestIsOSVersionAtLeast(string currentOSName)
  {
- foreach (string platfromName in AllKnownPlatformNames)
+ foreach (string platformName in AllKnownPlatformNames)
  {
- bool isCurrentOS = currentOSName.Equals(platfromName, StringComparison.OrdinalIgnoreCase);
+ bool isCurrentOS = currentOSName.Equals(platformName, StringComparison.OrdinalIgnoreCase);
 
- AssertVersionChecks(isCurrentOS, (major, minor, build, revision) => OperatingSystem.IsOSPlatformVersionAtLeast(platfromName, major, minor, build, revision));
- AssertVersionChecks(isCurrentOS, (major, minor, build, revision) => OperatingSystem.IsOSPlatformVersionAtLeast(platfromName.ToLower(), major, minor, build, revision));
- AssertVersionChecks(isCurrentOS, (major, minor, build, revision) => OperatingSystem.IsOSPlatformVersionAtLeast(platfromName.ToUpper(), major, minor, build, revision));
+ AssertVersionChecks(isCurrentOS, (major, minor, build, revision) => OperatingSystem.IsOSPlatformVersionAtLeast(platformName, major, minor, build, revision));
+ AssertVersionChecks(isCurrentOS, (major, minor, build, revision) => OperatingSystem.IsOSPlatformVersionAtLeast(platformName.ToLower(), major, minor, build, revision));
+ AssertVersionChecks(isCurrentOS, (major, minor, build, revision) => OperatingSystem.IsOSPlatformVersionAtLeast(platformName.ToUpper(), major, minor, build, revision));
  }
 
  AssertVersionChecks(currentOSName.Equals("Android", StringComparison.OrdinalIgnoreCase), OperatingSystem.IsAndroidVersionAtLeast);

src/libraries/System.Runtime/ref/System.Runtime.cs

@@ -4965,7 +4965,9 @@ public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, S
  public static bool IsFreeBSDVersionAtLeast(int major, int minor = 0, int build = 0, int revision = 0) { throw null; }
  public static bool IsAndroid() { throw null; }
  public static bool IsAndroidVersionAtLeast(int major, int minor = 0, int build = 0, int revision = 0) { throw null; }
+ [System.Runtime.Versioning.SupportedOSPlatformGuardAttribute("maccatalyst")]
  public static bool IsIOS() { throw null; }
+ [System.Runtime.Versioning.SupportedOSPlatformGuardAttribute("maccatalyst")]
  public static bool IsIOSVersionAtLeast(int major, int minor = 0, int build = 0) { throw null; }
  public static bool IsMacOS() { throw null; }
  public static bool IsMacOSVersionAtLeast(int major, int minor = 0, int build = 0) { throw null; }