[net6] Strip framework native libraries

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.AssemblyResolution.targets

@@ -12,6 +12,7 @@ _ResolveAssemblies MSBuild target.
 
   <UsingTask TaskName="Xamarin.Android.Tasks.ProcessAssemblies"      AssemblyFile="$(_XamarinAndroidBuildTasksAssembly)" />
   <UsingTask TaskName="Xamarin.Android.Tasks.ProcessNativeLibraries" AssemblyFile="$(_XamarinAndroidBuildTasksAssembly)" />
+  <UsingTask TaskName="Xamarin.Android.Tasks.StripNativeLibraries" AssemblyFile="$(_XamarinAndroidBuildTasksAssembly)" />
 
   <PropertyGroup Condition=" '$(_ComputeFilesToPublishForRuntimeIdentifiers)' == 'true' ">
     <OutputPath Condition=" '$(_OuterOutputPath)' != '' ">$(_OuterOutputPath)</OutputPath>
@@ -168,6 +169,26 @@ _ResolveAssemblies MSBuild target.
         IncludeDebugSymbols="$(AndroidIncludeDebugSymbols)">
       <Output TaskParameter="OutputLibraries" ItemName="FrameworkNativeLibrary" />
     </ProcessNativeLibraries>
+    <ItemGroup>
+      <_StrippedFrameworkNativeLibrary Include="@(FrameworkNativeLibrary->'$(IntermediateOutputPath)native\%(RuntimeIdentifier)\%(Filename)%(Extension)')" />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_StripFrameworkNativeLibraries"
+      Condition=" '$(AndroidIncludeDebugSymbols)' != 'true' "
+      DependsOnTargets="_IncludeNativeSystemLibraries"
+      Inputs="@(FrameworkNativeLibrary)"
+      Outputs="@(_StrippedFrameworkNativeLibrary)">
+    <StripNativeLibraries
+        SourceFiles="@(FrameworkNativeLibrary)"
+        DestinationFiles="@(_StrippedFrameworkNativeLibrary)"
+        ToolPath="$(AndroidBinUtilsDirectory)"
+    />
+    <ItemGroup Condition=" '$(AndroidIncludeDebugSymbols)' != 'true' ">
+      <FrameworkNativeLibrary Remove="@(FrameworkNativeLibrary)"/>
+      <FrameworkNativeLibrary Include="@(_StrippedFrameworkNativeLibrary)"/>
+      <FileWrites Include="@(_StrippedFrameworkNativeLibrary)" />
+    </ItemGroup>
   </Target>
 
 </Project>

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.BuildOrder.targets

@@ -72,6 +72,7 @@ projects, these properties are set in Xamarin.Android.Legacy.targets.
       _CheckApkPerAbiFlag;
       _LintChecks;
       _IncludeNativeSystemLibraries;
+      _StripFrameworkNativeLibraries;
       _CheckGoogleSdkRequirements;
     </_PrepareBuildApkDependsOnTargets>
   </PropertyGroup>

src/Xamarin.Android.Build.Tasks/Tasks/StripNativeLibraries.cs

@@ -0,0 +1,84 @@
+using System;
+using System.IO;
+using Microsoft.Build.Framework;
+using Microsoft.Android.Build.Tasks;
+using Xamarin.Android.Tools;
+using Microsoft.Build.Utilities;
+
+namespace Xamarin.Android.Tasks
+{
+	/// <summary>
+	/// Strips debug information from the native libraries
+	/// </summary>
+	public class StripNativeLibraries : AndroidToolTask
+	{
+		public override string TaskPrefix => "SNL";
+
+		public ITaskItem [] SourceFiles { get; set; }
+
+		public ITaskItem [] DestinationFiles { get; set; }
+
+		string triple;
+		ITaskItem source;
+		ITaskItem destination;
+
+		public override bool RunTask ()
+		{
+			if (SourceFiles.Length != DestinationFiles.Length)
+				throw new ArgumentException ("source and destination count mismatch");
+			if (SourceFiles == null || SourceFiles.Length == 0)
+				return true;
+
+			for (int i = 0; i < SourceFiles.Length; i++) {
+				source = SourceFiles [i];
+				destination = DestinationFiles [i];
+
+				var abi = AndroidRidAbiHelper.GetNativeLibraryAbi (source);
+				if (string.IsNullOrEmpty (abi)) {
+					var packageId = source.GetMetadata ("NuGetPackageId");
+					if (!string.IsNullOrEmpty (packageId)) {
+						Log.LogCodedWarning ("XA4301", source.ItemSpec, 0, Properties.Resources.XA4301_ABI_NuGet, source.ItemSpec, packageId);
+					} else {
+						Log.LogCodedWarning ("XA4301", source.ItemSpec, 0, Properties.Resources.XA4301_ABI, source.ItemSpec);
+					}
+					continue;
+				}
+
+				triple = GetNdkTripleFromAbi (abi);
+				Directory.CreateDirectory (Path.GetDirectoryName (destination.ItemSpec));
+
+				// This runs the tool
+				base.RunTask ();
+
+				// Stop early on failure
+				if (Log.HasLoggedErrors)
+					return false;
+			}
+
+			return !Log.HasLoggedErrors;
+		}
+
+		protected override string ToolName => OS.IsWindows ? $"{triple}-strip.exe" : $"{triple}-strip";
+
+		protected override string GenerateFullPathToTool () => Path.Combine (ToolPath, ToolName);
+
+		protected override string GenerateCommandLineCommands ()
+		{
+			var cmd = new CommandLineBuilder ();
+			cmd.AppendSwitchIfNotNull ("--strip-debug ", source.ItemSpec);
+			cmd.AppendSwitchIfNotNull ("-o ", destination.ItemSpec);
+			return cmd.ToString ();
+		}
+
+		string GetNdkTripleFromAbi (string abi)
+		{
+			return abi switch {
+				"arm64-v8a" => "aarch64-linux-android",
+				"armeabi-v7a" => "arm-linux-androideabi",
+				"x86" => "i686-linux-android",
+				"x86_64" => "x86_64-linux-android",
+				_ => throw new InvalidOperationException ($"Unknown ABI: {abi}"),
+			};
+		}
+	}
+}

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/XASdkTests.cs

@@ -385,8 +385,10 @@ public void DotNetBuild (string runtimeIdentifiers, bool isRelease)
 				Assert.IsTrue (StringAssertEx.ContainsText (dotnet.LastBuildOutput, " 0 Warning(s)"), "Should have no MSBuild warnings.");
 
 			var outputPath = Path.Combine (FullProjectDirectory, proj.OutputPath);
+			var intermediateOutputPath = Path.Combine (FullProjectDirectory, proj.IntermediateOutputPath);
 			if (!runtimeIdentifiers.Contains (";")) {
 				outputPath = Path.Combine (outputPath, runtimeIdentifiers);
+				intermediateOutputPath = Path.Combine (intermediateOutputPath, runtimeIdentifiers);
 			}
 
 			var files = Directory.EnumerateFileSystemEntries (outputPath)
@@ -411,6 +413,15 @@ public void DotNetBuild (string runtimeIdentifiers, bool isRelease)
 				Assert.IsNotNull (type, $"{assemblyPath} should contain {typeName}");
 			}
 
+			var rids = runtimeIdentifiers.Split (';');
+			if (isRelease) {
+				// Check for stripped native libraries
+				foreach (var rid in rids) {
+					FileAssert.Exists (Path.Combine (intermediateOutputPath, "native", rid, "libmono-android.release.so"));
+					FileAssert.Exists (Path.Combine (intermediateOutputPath, "native", rid, "libmonosgen-2.0.so"));
+				}
+			}
+
 			bool expectEmbeddedAssembies = !(CommercialBuildAvailable && !isRelease);
 			var apkPath = Path.Combine (outputPath, "UnnamedProject.UnnamedProject.apk");
 			FileAssert.Exists (apkPath);
@@ -419,7 +430,6 @@ public void DotNetBuild (string runtimeIdentifiers, bool isRelease)
 				apk.AssertContainsEntry (apkPath, $"assemblies/{proj.ProjectName}.pdb", shouldContainEntry: !CommercialBuildAvailable && !isRelease);
 				apk.AssertContainsEntry (apkPath, $"assemblies/System.Linq.dll",        shouldContainEntry: expectEmbeddedAssembies);
 				apk.AssertContainsEntry (apkPath, $"assemblies/es/{proj.ProjectName}.resources.dll", shouldContainEntry: expectEmbeddedAssembies);
-				var rids = runtimeIdentifiers.Split (';');
 				foreach (var abi in rids.Select (AndroidRidAbiHelper.RuntimeIdentifierToAbi)) {
 					apk.AssertContainsEntry (apkPath, $"lib/{abi}/libmonodroid.so");
 					apk.AssertContainsEntry (apkPath, $"lib/{abi}/libmonosgen-2.0.so");

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Resources/Base/BuildReleaseArm64SimpleDotNet.apkdesc

@@ -29,37 +29,25 @@
       "Size": 316988
     },
     "assemblies/UnnamedProject.dll": {
-      "Size": 2955
-    },
-    "assemblies/System.Collections.Concurrent.dll": {
-      "Size": 9341
-    },
-    "assemblies/System.Collections.dll": {
-      "Size": 4490
+      "Size": 2959
     },
     "assemblies/System.Console.dll": {
-      "Size": 6209
-    },
-    "assemblies/System.Linq.Expressions.dll": {
-      "Size": 115171
+      "Size": 6214
     },
     "assemblies/System.Linq.dll": {
-      "Size": 16987
-    },
-    "assemblies/System.ObjectModel.dll": {
-      "Size": 3372
+      "Size": 15127
     },
     "assemblies/System.Private.CoreLib.dll": {
-      "Size": 527251
+      "Size": 516700
     },
     "assemblies/Java.Interop.dll": {
-      "Size": 67979
+      "Size": 63117
     },
     "assemblies/Mono.Android.dll": {
-      "Size": 108095
+      "Size": 86318
     },
     "lib/arm64-v8a/libxamarin-app.so": {
-      "Size": 11904
+      "Size": 68560
     },
     "lib/arm64-v8a/libSystem.IO.Compression.Native.so": {
       "Size": 776216
@@ -71,26 +59,26 @@
       "Size": 100464
     },
     "lib/arm64-v8a/libmonosgen-2.0.so": {
-      "Size": 18570656
+      "Size": 3831000
     },
     "lib/arm64-v8a/libmonodroid.so": {
-      "Size": 254616
+      "Size": 250136
     },
     "lib/arm64-v8a/libxa-internal-api.so": {
-      "Size": 66544
+      "Size": 65480
     },
     "lib/arm64-v8a/libxamarin-debug-app-helper.so": {
-      "Size": 191408
+      "Size": 31672
     },
     "META-INF/ANDROIDD.SF": {
-      "Size": 2948
+      "Size": 2512
     },
     "META-INF/ANDROIDD.RSA": {
       "Size": 1213
     },
     "META-INF/MANIFEST.MF": {
-      "Size": 2821
+      "Size": 2385
     }
   },
-  "PackageSize": 8050955
+  "PackageSize": 2938815
 }

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Resources/Base/BuildReleaseArm64SimpleLegacy.apkdesc

@@ -29,37 +29,37 @@
       "Size": 316956
     },
     "assemblies/UnnamedProject.dll": {
-      "Size": 2861
+      "Size": 2862
     },
     "assemblies/Java.Interop.dll": {
-      "Size": 75724
+      "Size": 75153
     },
     "assemblies/Mono.Android.dll": {
-      "Size": 264062
+      "Size": 264429
     },
     "assemblies/mscorlib.dll": {
-      "Size": 779345
+      "Size": 769824
     },
     "assemblies/System.Core.dll": {
-      "Size": 149498
+      "Size": 28190
     },
     "assemblies/System.dll": {
       "Size": 12986
     },
     "lib/arm64-v8a/libxamarin-app.so": {
-      "Size": 19824
+      "Size": 68560
     },
     "lib/arm64-v8a/libmonodroid.so": {
-      "Size": 254616
+      "Size": 250696
     },
     "lib/arm64-v8a/libxa-internal-api.so": {
-      "Size": 66544
+      "Size": 65184
     },
     "lib/arm64-v8a/libmono-btls-shared.so": {
       "Size": 2160056
     },
     "lib/arm64-v8a/libmonosgen-2.0.so": {
-      "Size": 6823104
+      "Size": 6819144
     },
     "lib/arm64-v8a/libmono-native.so": {
       "Size": 1150064
@@ -74,5 +74,5 @@
       "Size": 2098
     }
   },
-  "PackageSize": 5142228
+  "PackageSize": 5011156
 }