[msbuild/dotnet] Automatically link with Swift's system libraries if …

…a binding project has the IsSwift=true property. (#20546)

Add support for the LinkWithSwiftSystemLibraries metadata to specify whether a native library is a Swift library, in which case we'll automatically set the `LinkWithSwiftSystemLibraries` MSBuild property to `true`.

Also add a test.

Make.config

@@ -390,6 +390,8 @@ IOS_PACKAGE_UTI=com.xamarin.$(IOS_PACKAGE_NAME_LOWER).pkg
 
 IOS_COMMON_DEFINES=-DMONOTOUCH
 
+SWIFTC=$(XCODE_DEVELOPER_ROOT)/Toolchains/XcodeDefault.xctoolchain/usr/bin/swiftc
+
 IOS_CC=$(XCODE_CC)
 IOS_CXX=$(XCODE_CXX)
 SIMULATOR_BIN_PATH=$(XCODE_DEVELOPER_ROOT)/Platforms/iPhoneSimulator.platform/Developer/usr/bin
@@ -502,6 +504,38 @@ MAC_OBJC_CFLAGS= -mmacosx-version-min=$(MIN_MACOS_SDK_VERSION) -DMONOMAC -DMIN_X
 MAC_CFLAGS = -mmacosx-version-min=$(MIN_MACOS_SDK_VERSION) -DMONOMAC -g -DMIN_XM_MONO_VERSION=\"$(MIN_XM_MONO_VERSION)\" $(CFLAGS)
 MAC_LDFLAGS = -mmacosx-version-min=$(MIN_MACOS_SDK_VERSION) -framework AppKit
 
+# Swift compiler flags
+
+COMMON_SWIFTFLAGS=-g -emit-library
+
+IOS_SIMULATOR_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(SIMULATOR_SDK)
+IOS_SIMULATOR_ARM64_SWIFTFLAGS=$(IOS_SIMULATOR_COMMON_SWIFTFLAGS) -target arm64-apple-ios$(MIN_IOS_SDK_VERSION)-simulator
+IOS_SIMULATOR_X64_SWIFTFLAGS=$(IOS_SIMULATOR_COMMON_SWIFTFLAGS) -target x86_64-apple-ios$(MIN_IOS_SDK_VERSION)-simulator
+IOS_DEVICE_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(DEVICE_SDK)
+IOS_DEVICE_ARM64_SWIFTFLAGS=$(IOS_DEVICE_COMMON_SWIFTFLAGS) -target arm64-apple-ios$(MIN_IOS_SDK_VERSION)
+
+TVOS_SIMULATOR_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(SIMULATORTV_SDK)
+TVOS_SIMULATOR_ARM64_SWIFTFLAGS=$(TVOS_SIMULATOR_COMMON_SWIFTFLAGS) -target arm64-apple-tvos$(MIN_TVOS_SDK_VERSION)-simulator
+TVOS_SIMULATOR_X64_SWIFTFLAGS=$(TVOS_SIMULATOR_COMMON_SWIFTFLAGS) -target x86_64-apple-tvos$(MIN_TVOS_SDK_VERSION)-simulator
+TVOS_DEVICE_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(DEVICETV_SDK)
+TVOS_DEVICE_ARM64_SWIFTFLAGS=$(TVOS_DEVICE_COMMON_SWIFTFLAGS) -target arm64-apple-tvos$(MIN_TVOS_SDK_VERSION)
+
+WATCHOS_SIMULATOR_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(SIMULATORWATCH_SDK)
+WATCHOS_SIMULATOR_ARM64_SWIFTFLAGS=$(WATCHOS_SIMULATOR_COMMON_SWIFTFLAGS) -target arm64-apple-watchos$(MIN_WATCHOS_SDK_VERSION)-simulator
+WATCHOS_SIMULATOR_X64_SWIFTFLAGS=$(WATCHOS_SIMULATOR_COMMON_SWIFTFLAGS) -target x86_64-apple-watchos$(MIN_WATCHOS_SDK_VERSION)-simulator
+WATCHOS_SIMULATOR_X86_SWIFTFLAGS=$(WATCHOS_SIMULATOR_COMMON_SWIFTFLAGS) -target x86-apple-watchos$(MIN_WATCHOS_SDK_VERSION)-simulator
+WATCHOS_DEVICE_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(DEVICEWATCH_SDK)
+WATCHOS_DEVICE_ARM64_32_SWIFTFLAGS=$(WATCHOS_DEVICE_COMMON_SWIFTFLAGS) -target arm64_32-apple-watchos$(MIN_WATCHOS_SDK_VERSION)
+WATCHOS_DEVICE_ARMV7K_SWIFTFLAGS=$(WATCHOS_DEVICE_COMMON_SWIFTFLAGS) -target armv7k-apple-watchos$(MIN_WATCHOS_SDK_VERSION)
+
+MACCATALYST_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(XCODE_MAC_SDKROOT)
+MACCATALYST_ARM64_SWIFTFLAGS=$(MACCATALYST_COMMON_SWIFTFLAGS) -target arm64-apple-ios$(MIN_MACCATALYST_SDK_VERSION)-macabi
+MACCATALYST_X64_SWIFTFLAGS=$(MACCATALYST_COMMON_SWIFTFLAGS) -target x86_64-apple-ios$(MIN_MACCATALYST_SDK_VERSION)-macabi
+
+MACOS_COMMON_SWIFTFLAGS=$(COMMON_SWIFTFLAGS) -sdk $(XCODE_MAC_SDKROOT)
+MACOS_ARM64_SWIFTFLAGS=$(MACOS_COMMON_SWIFTFLAGS) -target arm64-apple-macos$(MIN_MACOS_SDK_VERSION)
+MACOS_X64_SWIFTFLAGS=$(MACOS_COMMON_SWIFTFLAGS) -target x86_64-apple-macos$(MIN_MACOS_SDK_VERSION)
+
 # paths to the modules we depend on, as variables, so people can put
 # things in other places if they absolutely must.
 MONO_PATH=$(TOP)/external/mono

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -1479,16 +1479,23 @@
 		</_LinkNativeExecutableDependsOn>
 	</PropertyGroup>
 
-	<Target Name="_AddSwiftLinkerFlags" Condition="'$(LinkWithSwiftSystemLibraries)' == 'true'" DependsOnTargets="_DetectSdkLocations">
+	<Target Name="_AddSwiftLinkerFlags" DependsOnTargets="_DetectSdkLocations">
 		<PropertyGroup>
 			<_SwiftTargetPlatform Condition="'$(_PlatformName)' == 'iOS' And '$(_SdkIsSimulator)' == 'true'">iphonesimulator</_SwiftTargetPlatform>
 			<_SwiftTargetPlatform Condition="'$(_PlatformName)' == 'iOS' And '$(_SdkIsSimulator)' != 'true'">iphoneos</_SwiftTargetPlatform>
 			<_SwiftTargetPlatform Condition="'$(_PlatformName)' == 'tvOS' And '$(_SdkIsSimulator)' == 'true'">appletvsimulator</_SwiftTargetPlatform>
 			<_SwiftTargetPlatform Condition="'$(_PlatformName)' == 'tvOS' And '$(_SdkIsSimulator)' != 'true'">appletvos</_SwiftTargetPlatform>
 			<_SwiftTargetPlatform Condition="'$(_PlatformName)' == 'MacCatalyst'">macosx</_SwiftTargetPlatform> <!-- yes, 'macosx' and not 'maccatalyst': even though the resulting maccatalyst directory exists, it doesn't have anything useful in it -->
 			<_SwiftTargetPlatform Condition="'$(_PlatformName)' == 'macOS'">macosx</_SwiftTargetPlatform>
+
+			<_HasBindingLibraryWithSwift Condition="@(_BindingLibraryLinkWith->WithMetadataValue('LinkWithSwiftSystemLibraries', 'true')->Count()) &gt; 0">true</_HasBindingLibraryWithSwift>
+			<_HasFrameworkNativeReferenceWithSwift Condition="@(_FrameworkNativeReference->WithMetadataValue('LinkWithSwiftSystemLibraries', 'true')->Count()) &gt; 0">true</_HasFrameworkNativeReferenceWithSwift>
+			<_HasFileNativeReferenceWithSwift Condition="@(_FileNativeReference->WithMetadataValue('LinkWithSwiftSystemLibraries', 'true')->Count()) &gt; 0">true</_HasFileNativeReferenceWithSwift>
+
+			<!-- Automatically link with Swift system libraries if any of the native libraries we link with has LinkWithSwiftSystemLibraries=true -->
+			<LinkWithSwiftSystemLibraries Condition="'$(LinkWithSwiftSystemLibraries)' == '' And ('$(_HasBindingLibraryWithSwift)' == 'true' Or '$(_HasFrameworkNativeReferenceWithSwift)' == 'true' Or '$(_HasFileNativeReferenceWithSwift)' == 'true')">true</LinkWithSwiftSystemLibraries>
 		</PropertyGroup>
-		<ItemGroup>
+		<ItemGroup Condition="'$(LinkWithSwiftSystemLibraries)' == 'true'">
 			<_MainLinkerFlags Include="-L$(_SdkDevPath)/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/$(_SwiftTargetPlatform)/" />
 			<_MainLinkerFlags Include="-L$(_SdkRoot)/usr/lib/swift/" />
 		</ItemGroup>

mk/rules.mk

@@ -49,6 +49,9 @@ define NativeCompilationTemplate
 .libs/iphonesimulator/%$(1).x86_64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/iphonesimulator
 	$$(call Q_2,ASM,   [iphonesimulator]) $(SIMULATOR_CC) $(SIMULATOR64_CFLAGS)      $(SIM64_I) -g $(2) -c $$< -o $$@
 
+.libs/iphonesimulator/%$(1).x86_64.dylib: %.swift | .libs/iphonesimulator
+	$$(call Q_2,SWIFT, [iphonesimulator]) $(SWIFTC)       $(IOS_SIMULATOR_X64_SWIFTFLAGS)                 $$< -o $$@
+
 .libs/iphonesimulator/%$(1).x86_64.dylib: | .libs/iphonesimulator
 	$$(call Q_2,LD,    [iphonesimulator]) $(SIMULATOR_CC) $(SIMULATOR64_CFLAGS)      $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_IOSSIMULATOR_SDK)/lib -fapplication-extension
 
@@ -66,6 +69,9 @@ define NativeCompilationTemplate
 .libs/iphonesimulator/%$(1).arm64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/iphonesimulator
 	$$(call Q_2,ASM,   [iphonesimulator]) $(SIMULATOR_CC) $(SIMULATOR_ARM64_CFLAGS)      $(SIM64_I) -g $(2) -c $$< -o $$@
 
+.libs/iphonesimulator/%$(1).arm64.dylib: %.swift | .libs/iphonesimulator
+	$$(call Q_2,SWIFT, [iphonesimulator]) $(SWIFTC)       $(IOS_SIMULATOR_ARM64_SWIFTFLAGS)                    $$< -o $$@
+
 .libs/iphonesimulator/%$(1).arm64.dylib: | .libs/iphonesimulator
 	$$(call Q_2,LD,    [iphonesimulator]) $(SIMULATOR_CC) $(SIMULATOR_ARM64_CFLAGS)      $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_IOSSIMULATOR_SDK)/lib -fapplication-extension
 
@@ -108,6 +114,9 @@ define NativeCompilationTemplate
 .libs/iphoneos/%$(1).arm64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/iphoneos
 	$$(call Q_2,ASM,   [iphoneos]) $(DEVICE_CC) $(DEVICE64_CFLAGS)      $$(EXTRA_DEFINES) $(DEV64_I) -g $(2) -c $$< -o $$@
 
+.libs/iphoneos/%$(1).arm64.dylib: %.swift | .libs/iphoneos
+	$$(call Q_2,SWIFT, [iphoneos]) $(SWIFTC)    $(IOS_DEVICE_ARM64_SWIFTFLAGS)                                  $$< -o $$@
+
 .libs/iphoneos/%$(1).arm64.dylib: | .libs/iphoneos
 	$$(call Q_2,LD,    [iphoneos]) $(DEVICE_CC) $(DEVICE64_CFLAGS)      $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_IPHONEOS_SDK)/lib -fapplication-extension
 
@@ -125,6 +134,9 @@ define NativeCompilationTemplate
 .libs/maccatalyst/%$(1).x86_64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/maccatalyst
 	$$(call Q_2,ASM,   [maccatalyst]) $(XCODE_CC) $(MACCATALYST_X86_64_CFLAGS)                        $(COMMON_I) -g $(2) -c $$< -o $$@
 
+.libs/maccatalyst/%$(1).x86_64.dylib: %.swift | .libs/maccatalyst
+	$$(call Q_2,SWIFT, [maccatalyst]) $(SWIFTC)   $(MACCATALYST_X64_SWIFTFLAGS)                                              $$< -o $$@
+
 .libs/maccatalyst/%$(1).x86_64.dylib: | .libs/maccatalyst
 	$$(call Q_2,LD,    [maccatalyst]) $(XCODE_CC) $(MACCATALYST_X86_64_CFLAGS)      $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_MACCATALYST_SDK)/lib -fapplication-extension
 
@@ -140,6 +152,9 @@ define NativeCompilationTemplate
 .libs/maccatalyst/%$(1).arm64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/maccatalyst
 	$$(call Q_2,ASM,   [maccatalyst]) $(XCODE_CC) $(MACCATALYST_ARM64_CFLAGS)                        $(COMMON_I) -g $(2) -c $$< -o $$@
 
+.libs/maccatalyst/%$(1).arm64.dylib: %.swift | .libs/maccatalyst
+	$$(call Q_2,SWIFT, [maccatalyst]) $(SWIFTC)   $(MACCATALYST_ARM64_SWIFTFLAGS)                                           $$< -o $$@
+
 .libs/maccatalyst/%$(1).arm64.dylib: | .libs/maccatalyst
 	$$(call Q_2,LD,    [maccatalyst]) $(XCODE_CC) $(MACCATALYST_ARM64_CFLAGS)      $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_MACCATALYST_SDK)/lib -fapplication-extension
 
@@ -157,6 +172,9 @@ define NativeCompilationTemplate
 .libs/watchsimulator/%$(1).x86.o: %.s $(EXTRA_DEPENDENCIES) | .libs/watchsimulator
 	$$(call Q_2,ASM,   [watchsimulator]) $(SIMULATOR_CC) $(SIMULATORWATCH_CFLAGS)        $$(EXTRA_DEFINES) $(SIMW_I) -g $(2) -c $$< -o $$@
 
+.libs/watchsimulator/%$(1).x86.dylib: %.swift | .libs/watchsimulator
+	$$(call Q_2,SWIFT, [watchsimulator]) $(SWIFTC)       $(WATCHOS_SIMULATOR_X86_SWIFTFLAGS)                                    $$< -o $$@
+
 .libs/watchsimulator/%$(1).x86.dylib: | .libs/watchsimulator
 	$$(call Q_2,LD,    [watchsimulator]) $(SIMULATOR_CC) $(SIMULATORWATCH_CFLAGS)        $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_WATCHSIMULATOR_SDK)/lib -fapplication-extension
 
@@ -172,6 +190,9 @@ define NativeCompilationTemplate
 .libs/watchsimulator/%$(1).x86_64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/watchsimulator
 	$$(call Q_2,ASM,   [watchsimulator]) $(SIMULATOR_CC) $(SIMULATORWATCH64_CFLAGS)      $$(EXTRA_DEFINES) $(SIMW64_I) -g $(2) -c $$< -o $$@
 
+.libs/watchsimulator/%$(1).x86_64.dylib: %.swift | .libs/watchsimulator
+	$$(call Q_2,SWIFT, [watchsimulator]) $(SWIFTC)       $(WATCHOS_SIMULATOR_X64_SWIFTFLAGS)                                      $$< -o $$@
+
 .libs/watchsimulator/%$(1).x86_64.dylib: | .libs/watchsimulator
 	$$(call Q_2,LD,    [watchsimulator]) $(SIMULATOR_CC) $(SIMULATORWATCH64_CFLAGS)      $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_WATCHSIMULATOR_SDK)/lib -fapplication-extension
 
@@ -186,6 +207,9 @@ define NativeCompilationTemplate
 .libs/watchos/%$(1).armv7k.o: %.c $(EXTRA_DEPENDENCIES) | .libs/watchos
 	$$(call Q_2,CC,    [watchos]) $(DEVICE_CC) $(DEVICEWATCH_CFLAGS)         $$(EXTRA_DEFINES) $(DEVW_I) -g $(2) -c $$< -o $$@ 
 
+.libs/watchos/%$(1).armv7k.dylib: %.swift | .libs/watchsimulator
+	$$(call Q_2,SWIFT, [watchos]) $(SWIFTC)    $(WATCHOS_DEVICE_ARMV7K_SWIFTFLAGS)                                  $$< -o $$@
+
 .libs/watchos/%$(1).armv7k.dylib: | .libs/watchos
 	$$(call Q_2,LD,    [watchos]) $(DEVICE_CC) $(DEVICEWATCH_CFLAGS)          $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_WATCHOS_SDK)/lib -fapplication-extension
 
@@ -198,6 +222,9 @@ define NativeCompilationTemplate
 .libs/watchos/%$(1).arm64_32.o: %.c $(EXTRA_DEPENDENCIES) | .libs/watchos
 	$$(call Q_2,CC,    [watchos]) $(DEVICE_CC) $(DEVICEWATCH64_32_CFLAGS)         $$(EXTRA_DEFINES) $(DEVW64_32_I) -g $(2) -c $$< -o $$@
 
+.libs/watchos/%$(1).arm64_32.dylib: %.swift | .libs/watchsimulator
+	$$(call Q_2,SWIFT, [watchos]) $(SWIFTC)    $(WATCHOS_DEVICE_ARM64_32_SWIFTFLAGS)                                          $$< -o $$@
+
 .libs/watchos/%$(1).arm64_32.dylib: | .libs/watchos
 	$$(call Q_2,LD,    [watchos]) $(DEVICE_CC) $(DEVICEWATCH64_32_CFLAGS)          $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_WATCHOS_SDK)/lib -fapplication-extension
 
@@ -217,6 +244,9 @@ define NativeCompilationTemplate
 .libs/tvsimulator/%$(1).x86_64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/tvsimulator
 	$$(call Q_2,ASM,   [tvsimulator]) $(SIMULATOR_CC) $(SIMULATORTV_CFLAGS)         $$(EXTRA_DEFINES) $(SIM_TV_I) -g $(2) -c $$< -o $$@
 
+.libs/tvsimulator/%$(1).x86_64.dylib: %.swift | .libs/tvsimulator
+	$$(call Q_2,SWIFT, [tvsimulator]) $(SWIFTC)      $(TVOS_SIMULATOR_X64_SWIFTFLAGS)                                        $$< -o $$@
+
 .libs/tvsimulator/%$(1).x86_64.dylib: | .libs/tvsimulator
 	$$(call Q_2,LD,    [tvsimulator]) $(SIMULATOR_CC) $(SIMULATORTV_CFLAGS)         $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_TVSIMULATOR_SDK)/lib -fapplication-extension
 
@@ -234,6 +264,9 @@ define NativeCompilationTemplate
 .libs/tvsimulator/%$(1).arm64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/tvsimulator
 	$$(call Q_2,ASM,   [tvsimulator]) $(SIMULATOR_CC) $(SIMULATORTV_ARM64_CFLAGS)         $$(EXTRA_DEFINES) $(SIM_ARM64_TV_I) -g $(2) -c $$< -o $$@
 
+.libs/tvsimulator/%$(1).arm64.dylib: %.swift | .libs/tvsimulator
+	$$(call Q_2,SWIFT, [tvsimulator]) $(SWIFTC)      $(TVOS_SIMULATOR_ARM64_SWIFTFLAGS)                                                  $$< -o $$@
+
 .libs/tvsimulator/%$(1).arm64.dylib: | .libs/tvsimulator
 	$$(call Q_2,LD,    [tvsimulator]) $(SIMULATOR_CC) $(SIMULATORTV_ARM64_CFLAGS)         $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_TVSIMULATOR_SDK)/lib -fapplication-extension
 
@@ -251,6 +284,9 @@ define NativeCompilationTemplate
 .libs/tvos/%$(1).arm64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/tvos
 	$$(call Q_2,ASM,   [tvos]) $(DEVICE_CC)    $(DEVICETV_CFLAGS)            $$(EXTRA_DEFINES) $(DEV_TV_I) -g $(2) -c $$< -o $$@
 
+.libs/tvos/%$(1).arm64.dylib: %.swift | .libs/tvos
+	$$(call Q_2,SWIFT, [tvos]) $(SWIFTC)      $(TVOS_DEVICE_ARM64_SWIFTFLAGS)                                         $$< -o $$@
+
 .libs/tvos/%$(1).arm64.dylib: | .libs/tvos
 	$$(call Q_2,LD,    [tvos]) $(DEVICE_CC)    $(DEVICETV_CFLAGS)            $$(EXTRA_FLAGS) -dynamiclib -o $$@ $$^ -L$(IOS_DESTDIR)$(XAMARIN_TVOS_SDK)/lib -fapplication-extension
 
@@ -268,6 +304,12 @@ define NativeCompilationTemplate
 .libs/mac/%$(1).x86_64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/mac
 	$$(call Q_2,ASM,   [mac]) $(MAC_CC) $(MAC_CFLAGS)                        -arch x86_64  $(COMMON_I) -g $(2) -c $$< -o $$@
 
+.libs/mac/%$(1).x86_64.dylib: %.swift | .libs/mac
+	$$(call Q_2,SWIFT, [mac]) $(SWIFTC) $(MACOS_X64_SWIFTFLAGS)                                                   $$< -o $$@
+
+.libs/macos/%$(1).x86_64.dylib: %.swift | .libs/mac
+	$$(call Q_2,SWIFT, [macos]) $(SWIFTC) $(MACOS_X64_SWIFTFLAGS)                                                 $$< -o $$@
+
 .libs/mac/%$(1).x86_64.dylib: | .libs/mac
 	$$(call Q_2,LD,    [mac]) $(MAC_CC) $(MAC_CFLAGS)      $$(EXTRA_FLAGS) -arch x86_64 -dynamiclib -o $$@ $$^ -L$(MAC_DESTDIR)$(XAMARIN_MACOS_SDK)/lib -fapplication-extension
 
@@ -283,6 +325,12 @@ define NativeCompilationTemplate
 .libs/mac/%$(1).arm64.o: %.s $(EXTRA_DEPENDENCIES) | .libs/mac
 	$$(call Q_2,ASM,   [mac]) $(MAC_CC) $(MAC_CFLAGS)                        -arch arm64  $(COMMON_I) -g $(2) -c $$< -o $$@
 
+.libs/mac/%$(1).arm64.dylib: %.swift | .libs/mac
+	$$(call Q_2,SWIFT, [mac]) $(SWIFTC) $(MACOS_ARM64_SWIFTFLAGS)                                                $$< -o $$@
+
+.libs/macos/%$(1).arm64.dylib: %.swift | .libs/mac
+	$$(call Q_2,SWIFT, [macos]) $(SWIFTC) $(MACOS_ARM64_SWIFTFLAGS)                                              $$< -o $$@
+
 .libs/mac/%$(1).arm64.dylib: | .libs/mac
 	$$(call Q_2,LD,    [mac]) $(MAC_CC) $(MAC_CFLAGS)      $$(EXTRA_FLAGS) -arch arm64 -dynamiclib -o $$@ $$^ -L$(MAC_DESTDIR)$(XAMARIN_MACOS_SDK)/lib -fapplication-extension
 

msbuild/Xamarin.MacDev.Tasks/Tasks/CreateBindingResourcePackage.cs

@@ -137,7 +137,7 @@ static bool ContainsSymlinks (ITaskItem [] items)
 			return false;
 		}
 
-		string [] NativeReferenceAttributeNames = new string [] { "Kind", "ForceLoad", "SmartLink", "Frameworks", "WeakFrameworks", "LinkerFlags", "NeedsGccExceptionHandling", "IsCxx" };
+		string [] NativeReferenceAttributeNames = new string [] { "Kind", "ForceLoad", "SmartLink", "Frameworks", "WeakFrameworks", "LinkerFlags", "NeedsGccExceptionHandling", "IsCxx", "LinkWithSwiftSystemLibraries" };
 
 		string CreateManifest (string resourcePath)
 		{

msbuild/Xamarin.MacDev.Tasks/Tasks/PrepareNativeReferences.cs

@@ -148,6 +148,7 @@ public override bool Execute ()
 				text.AppendFormat ("[assembly: ObjCRuntime.LinkWith (\"{0}\"", logicalName);
 				AppendLinkTargetProperty (text, NativeReferences [i]);
 				AppendBooleanProperty (text, NativeReferences [i], "IsCxx");
+				AppendBooleanProperty (text, NativeReferences [i], "LinkWithSwiftSystemLibraries");
 				AppendBooleanProperty (text, NativeReferences [i], "NeedsGccExceptionHandling");
 				AppendBooleanProperty (text, NativeReferences [i], "SmartLink", true);
 				AppendBooleanProperty (text, NativeReferences [i], "ForceLoad");

msbuild/Xamarin.MacDev.Tasks/Tasks/ResolveNativeReferences.cs

@@ -352,6 +352,7 @@ void ProcessSidecar (ITaskItem r, string resources, List<ITaskItem> native_frame
 				t.SetMetadata ("ForceLoad", "False");
 				t.SetMetadata ("NeedsGccExceptionHandling", "False");
 				t.SetMetadata ("IsCxx", "False");
+				t.SetMetadata ("LinkWithSwiftSystemLibraries", "False");
 				t.SetMetadata ("SmartLink", "True");
 
 				// values from manifest, overriding defaults if provided

src/ObjCRuntime/LinkWithAttribute.cs

@@ -104,6 +104,12 @@ public LinkWithAttribute ()
 			get; set;
 		}
 
+		/// <summary>Determines whether the library uses Swift.</summary>
+		/// <remarks>If this is true, the app will automatically link with the Swift system libraries.</remarks>
+		public bool LinkWithSwiftSystemLibraries {
+			get; set;
+		}
+
 		public bool SmartLink {
 			get; set;
 		}

tests/bindings-test/ApiDefinition.cs

@@ -456,4 +456,12 @@ interface ProtocolWithBlockProperties {
 		SimpleCallback MyOptionalStaticProperty { get; set; }
 	}
 	interface IProtocolWithBlockProperties { }
+
+#if NET
+	[BaseType (typeof (NSObject))]
+	interface SwiftTestClass {
+		[Export ("SayHello")]
+		string SayHello ();
+	}
+#endif
 }

tests/bindings-test/RuntimeTest.cs

@@ -95,5 +95,15 @@ public override void AssertMainThreadBlockReleaseCallback (InnerBlock completion
 				completionHandler (42);
 			}
 		}
+
+#if NET
+		[Test]
+		public void SwiftTest ()
+		{
+			TestRuntime.AssertXcodeVersion (13, 0);
+			using var obj = new SwiftTestClass ();
+			Assert.AreEqual ("Hello from Swift", obj.SayHello (), "Hello");
+		}
+#endif
 	}
 }

tests/bindings-test/dotnet/shared.csproj

@@ -38,6 +38,11 @@
       <Kind>Static</Kind>
       <Frameworks>CoreLocation Foundation ModelIO</Frameworks>
     </NativeReference>
+
+    <NativeReference Include="$(TestLibrariesDirectory)\.libs\SwiftTest.xcframework">
+      <Kind>Framework</Kind>
+      <LinkWithSwiftSystemLibraries>true</LinkWithSwiftSystemLibraries>
+    </NativeReference>
   </ItemGroup>
 
   <ItemGroup>

tests/dotnet/UnitTests/ProjectTest.cs

@@ -190,7 +190,7 @@ public void BuildBindingsTest (ApplePlatform platform)
 			// Verify that there's one resource in the binding assembly, and its name
 			var ad = AssemblyDefinition.ReadAssembly (asm, new ReaderParameters { ReadingMode = ReadingMode.Deferred });
 			Assert.That (ad.MainModule.Resources.Count, Is.EqualTo (0), "no embedded resources");
-			var resourceBundle = Path.Combine (project_dir, "bin", "Debug", platform.ToFramework (), assemblyName + ".resources");
+			var resourceBundle = Path.Combine (project_dir, "bin", "Debug", platform.ToFramework (), assemblyName + ".resources.zip");
 			Assert.That (resourceBundle, Does.Exist, "Bundle existence");
 		}