[Xamarin.Android.Build.Tasks] Add Support for bundletool meta-data

Context dotnet#5378

Add a new property `AndroidCreateProguardMappingFile` to control the
creation of the proguard mapping file.
This will default to `False` because it does has some impact on the final
apk sizes.

Also Provide a default value for `AndroidProguardMappingFile` when using
`AndroidLinkTool=r8` and `AndroidCreateProguardMappingFile=True`.

Add support for providing meta-data files to `bundletool` when building
the app bundle. This allows developers to provide additional meta-data
such as the proguard mapping file. The new ItemGroup is called
`AndroidAppBundleMetaDataFile`.

Documentation/guides/building-apps/build-items.md

@@ -38,6 +38,26 @@ Used to provide an AOT profile, for use with profile-guided AOT.
 It can be also used from Visual Studio by setting the `AndroidAotProfile`
 build action to a file containing an AOT profile.
 
+## AndroidAppBundleMetaDataFile
+
+Specifies a file that will be included as metadata in the Android App Bundle.
+The format of the flag value is `<bundle-path>:<physical-file>` where
+`bundle-path` denotes the file location inside the App Bundle's metadata
+directory, and `physical-file` is an existing file containing the raw data
+to be stored.
+
+```xml
+<ItemGroup>
+  <AndroidAppBundleMetaDataFile
+    Include="com.android.tools.build.obfuscation/proguard.map:$(OutputPath)mapping.txt"
+  />
+</ItemGroup>
+```
+
+See [bundletool](https://developer.android.com/studio/build/building-cmdline#build_your_app_bundle_using_bundletool) documentation for more details.
+
+Added in Xamarin.Android 12.3.
+
 ## AndroidBoundLayout
 
 Indicates that the layout file is to have code-behind generated for it in case when

Documentation/guides/building-apps/build-properties.md

@@ -300,6 +300,28 @@ should be created instead of having support for all ABIs in a single `.apk`.
 See also the [Building ABI-Specific APKs](~/android/deploy-test/building-apps/abi-specific-apks.md)
 guide.
 
+## AndroidCreateProguardMappingFile
+
+A boolean property that controls if a proguard mapping file is
+generated as part of the build process.
+
+Adding the following to your csproj will cause the file to be
+generated. This uses the [`AndroidProguardMappingFile`](#androidproguardmappingfile) property
+to control the location of the final mapping file.
+
+```
+<AndroidCreateProguardMappingFile>True</AndroidCreateProguardMappingFile>
+```
+
+Note that if you are using `.aab` files the mapping file with be
+automatically included in your package. So there is no need to upload
+it to the Google Play Store manually. If you are using `.apk` files
+you will need to manually upload the [`AndroidProguardMappingFile`](#androidproguardmappingfile).
+
+The default value is `False`.
+
+Added in Xamarin.Android 12.3.
+
 ## AndroidDebugKeyAlgorithm
 
 Specifies the default
@@ -987,7 +1009,19 @@ mean the `mapping.txt` file will be produced in the `$(OutputPath)`
 folder. This file can then be used when uploading packages to the
 Google Play Store.
 
-The default value is `$(OutputPath)mapping.txt`.
+By default this file is not produced.
+
+If you do want to generate this mapping file you can use the
+[`AndroidCreateProguardMappingFile`](#androidcreateproguardmappingfile) property to create it .
+Add the following in your project
+
+```
+<AndroidCreateProguardMappingFile>True</AndroidCreateProguardMappingFile>
+```
+
+or use `-p:AndroidCreateProguardMappingFile=True` on the command line.
+
+This will then generate the following file `$(OutputPath)mapping.txt`.
 
 This property was added in Xamarin.Android 11.2.
 

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

@@ -12,7 +12,7 @@ namespace Xamarin.Android.Tasks
 {
 	/// <summary>
 	/// Invokes `bundletool` to create an Android App Bundle (.aab file)
-	/// 
+	///
 	/// Usage: bundletool build-bundle --modules=base.zip --output=foo.aab --config=BundleConfig.json
 	/// </summary>
 	public class BuildAppBundle : BundleTool
@@ -63,9 +63,11 @@ public class BuildAppBundle : BundleTool
 		public string BaseZip { get; set; }
 
 		public string CustomBuildConfigFile { get; set; }
-		
+
 		public string [] Modules { get; set; }
 
+		public ITaskItem [] MetaDataFiles { get; set; }
+
 		[Required]
 		public string Output { get; set; }
 
@@ -130,6 +132,9 @@ internal override CommandLineBuilder GetCommandLineBuilder ()
 			cmd.AppendSwitchIfNotNull ("--modules ", string.Join (",", modules));
 			cmd.AppendSwitchIfNotNull ("--output ", Output);
 			cmd.AppendSwitchIfNotNull ("--config ", temp);
+			foreach (var file in MetaDataFiles ?? Array.Empty<ITaskItem> ()) {
+				cmd.AppendSwitch ($"--metadata-file={file.ItemSpec}");
+			}
 			return cmd;
 		}
 	}

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

@@ -125,7 +125,7 @@ protected override string GenerateCommandLineCommands ()
 					if (!string.IsNullOrEmpty (ProguardMappingFileOutput)) {
 						xamcfg.WriteLine ("-keepattributes SourceFile");
 						xamcfg.WriteLine ("-keepattributes LineNumberTable");
-						xamcfg.WriteLine ($"-printmapping {Path.GetFullPath (ProguardMappingFileOutput)}");
+						xamcfg.WriteLine ($"-printmapping \"{Path.GetFullPath (ProguardMappingFileOutput)}\"");
 					}
 				}
 			}

src/Xamarin.Android.Build.Tasks/Tasks/R8.cs

@@ -104,7 +104,7 @@ protected override CommandLineBuilder GetCommandLineBuilder ()
 						if (!string.IsNullOrEmpty (ProguardMappingFileOutput)) {
 							xamcfg.WriteLine ("-keepattributes SourceFile");
 							xamcfg.WriteLine ("-keepattributes LineNumberTable");
-							xamcfg.WriteLine ($"-printmapping {Path.GetFullPath (ProguardMappingFileOutput)}");
+							xamcfg.WriteLine ($"-printmapping \"{Path.GetFullPath (ProguardMappingFileOutput)}\"");
 						}
 					}
 				}
@@ -125,7 +125,7 @@ protected override CommandLineBuilder GetCommandLineBuilder ()
 				if (!string.IsNullOrEmpty (ProguardMappingFileOutput)) {
 					lines.Add ("-keepattributes SourceFile");
 					lines.Add ("-keepattributes LineNumberTable");
-					lines.Add ($"-printmapping {Path.GetFullPath (ProguardMappingFileOutput)}");
+					lines.Add ($"-printmapping \"{Path.GetFullPath (ProguardMappingFileOutput)}\"");
 				}
 				File.WriteAllLines (temp, lines);
 				tempFiles.Add (temp);

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

@@ -56,8 +56,8 @@ public void CheckProguardMappingFileExists ()
 			};
 			proj.SetProperty (proj.ReleaseProperties, KnownProperties.AndroidDexTool, "d8");
 			proj.SetProperty (proj.ReleaseProperties, KnownProperties.AndroidLinkTool, "r8");
-			// Projects must provide a $(AndroidProguardMappingFile) value to opt in
-			proj.SetProperty (proj.ReleaseProperties, "AndroidProguardMappingFile", @"$(OutputPath)\mapping.txt");
+			// Projects must set $(AndroidCreateProguardMappingFile) to true to opt in
+			proj.SetProperty (proj.ReleaseProperties, "AndroidCreateProguardMappingFile", true);
 
 			using (var b = CreateApkBuilder ()) {
 				string mappingFile = Path.Combine (Root, b.ProjectDirectory, proj.OutputPath, "mapping.txt");

src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets

@@ -1807,6 +1807,7 @@ because xbuild doesn't support framework reference assemblies.
 		_CreateApplicationSharedLibraries;
 		_GetMonoPlatformJarPath;
 		_GetLibraryImports;
+		_SetProguardMappingFileProperty;
 		_CalculateProguardConfigurationFiles;
 	</_CompileToDalvikDependsOnTargets>
 	<_CompileToDalvikInputs>
@@ -1826,6 +1827,12 @@ because xbuild doesn't support framework reference assemblies.
 	</_CompileDexDependsOn>
 </PropertyGroup>
 
+<Target Name="_SetProguardMappingFileProperty">
+	<PropertyGroup>
+		<AndroidProguardMappingFile Condition=" '$(AndroidLinkTool)' == 'r8' And '$(AndroidCreateProguardMappingFile)' == 'True' ">$(OutputPath)mapping.txt</AndroidProguardMappingFile>
+	</PropertyGroup>
+</Target>
+
 <Target Name="_CalculateProguardConfigurationFiles">
   <!-- Support the $(ProguardConfigFiles) property to keep backwards compatibility -->
   <ItemGroup Condition=" '$(ProguardConfigFiles)' != '' ">
@@ -1967,6 +1974,12 @@ because xbuild doesn't support framework reference assemblies.
       $(ApkFileIntermediate)
     </_BuildApkEmbedOutputs>
   </PropertyGroup>
+  <ItemGroup>
+    <AndroidAppBundleMetaDataFile
+        Condition=" '$(AndroidProguardMappingFile)' != '' And Exists ('$(AndroidProguardMappingFile)') "
+        Include="com.android.tools.build.obfuscation/proguard.map:$(AndroidProguardMappingFile)"
+    />
+  </ItemGroup>
 </Target>
 
 <PropertyGroup>
@@ -2064,6 +2077,7 @@ because xbuild doesn't support framework reference assemblies.
       Output="$(_AppBundleIntermediate)"
       UncompressedFileExtensions="$(AndroidStoreUncompressedFileExtensions)"
       CustomBuildConfigFile="$(AndroidBundleConfigurationFile)"
+      MetaDataFiles="@(AndroidAppBundleMetaDataFile)"
   />
 </Target>
 

tests/apk-sizes-reference/com.companyname.vsandroidapp-Signed-Release.apkdesc

@@ -5,13 +5,13 @@
       "Size": 2896
     },
     "assemblies/assemblies.blob": {
-      "Size": 2026794
+      "Size": 2027538
     },
     "assemblies/assemblies.manifest": {
       "Size": 1574
     },
     "classes.dex": {
-      "Size": 2940564
+      "Size": 2940568
     },
     "lib/armeabi-v7a/libmono-btls-shared.so": {
       "Size": 1112688
@@ -20,16 +20,16 @@
       "Size": 736396
     },
     "lib/armeabi-v7a/libmonodroid.so": {
-      "Size": 232320
+      "Size": 234328
     },
     "lib/armeabi-v7a/libmonosgen-2.0.so": {
-      "Size": 4456332
+      "Size": 4456576
     },
     "lib/armeabi-v7a/libxa-internal-api.so": {
       "Size": 48844
     },
     "lib/armeabi-v7a/libxamarin-app.so": {
-      "Size": 46832
+      "Size": 46844
     },
     "lib/x86/libmono-btls-shared.so": {
       "Size": 1459584
@@ -38,16 +38,16 @@
       "Size": 803352
     },
     "lib/x86/libmonodroid.so": {
-      "Size": 303316
+      "Size": 305648
     },
     "lib/x86/libmonosgen-2.0.so": {
-      "Size": 4212220
+      "Size": 4212336
     },
     "lib/x86/libxa-internal-api.so": {
       "Size": 61112
     },
     "lib/x86/libxamarin-app.so": {
-      "Size": 45500
+      "Size": 45632
     },
     "META-INF/android.arch.core_runtime.version": {
       "Size": 6
@@ -1610,5 +1610,5 @@
       "Size": 320016
     }
   },
-  "PackageSize": 9500681
+  "PackageSize": 9504777
 }