dotnet · simonrozsival · Jul 3, 2026 · Jul 3, 2026 · Jul 3, 2026 · Jul 3, 2026
@@ -518,7 +518,11 @@ internal static void ApplyPlaceholders (XDocument doc, string? placeholders, str
 				var eqIndex = entry.IndexOf ('=');
 				if (eqIndex > 0) {
 					var key = entry.Substring (0, eqIndex).Trim ();
-					var value = entry.Substring (eqIndex + 1).Trim ();
+					// Normalize '\' to the platform directory separator to match the legacy pipeline,
+					// where the substituted manifest is re-encoded by aapt2 (which rewrites backslashes
+					// to '/' on Unix). The trimmable generator writes the merged manifest directly, so we
+					// apply the same normalization here to keep placeholder values byte-for-byte identical.
+					var value = entry.Substring (eqIndex + 1).Trim ().Replace ('\\', Path.DirectorySeparatorChar);
 					replacements ["${" + key + "}"] = value;
 				} else if (eqIndex < 0) {
 					// An entry without '=' is not a valid key=value pair. Mirror the legacy

@@ -5,13 +5,22 @@
   <UsingTask TaskName="Xamarin.Android.Tasks.GenerateNativeAotProguardConfiguration" AssemblyFile="$(_XamarinAndroidBuildTasksAssembly)" />
 
   <PropertyGroup>
+    <!-- Controls DGML-based trimming of Java Callable Wrappers on the trimmable NativeAOT path.
+         When true, ILC emits a DGML dependency graph and _GenerateTrimmableTypeMapProguardConfiguration
+         turns it into R8 -keep rules so R8 can shrink the unused JCWs from classes.dex. Those DGML files
+         are very large (hundreds of MB) and dominate build time, so this defaults to false until ILC/illink
+         expose a leaner typemap dump: R8 still runs, but every JCW is kept (a few hundred kB of extra dex)
+         and the DGML is never generated. -->
+    <_AndroidTrimmableTypemapTrimJavaCode Condition=" '$(_AndroidTrimmableTypemapTrimJavaCode)' == '' ">false</_AndroidTrimmableTypemapTrimJavaCode>
     <_TrimmableRuntimeProviderJavaName Condition=" '$(_TrimmableRuntimeProviderJavaName)' == '' ">net.dot.jni.nativeaot.NativeAotRuntimeProvider</_TrimmableRuntimeProviderJavaName>
     <AndroidLinkTool Condition=" '$(AndroidLinkTool)' == '' ">r8</AndroidLinkTool>
     <AndroidDexTool Condition=" '$(AndroidLinkTool)' == 'r8' ">d8</AndroidDexTool>
     <AndroidEnableProguard Condition=" '$(AndroidLinkTool)' != '' ">True</AndroidEnableProguard>
     <AndroidCreateProguardMappingFile Condition=" '$(AndroidCreateProguardMappingFile)' == '' and '$(AndroidLinkTool)' == 'r8' ">True</AndroidCreateProguardMappingFile>
-    <IlcGenerateDgmlFile Condition=" '$(AndroidLinkTool)' != '' and '$(IlcGenerateDgmlFile)' == '' ">true</IlcGenerateDgmlFile>
+    <!-- Only ask ILC for the DGML when JCW trimming is enabled; it is only consumed to compute the keep rules. -->
+    <IlcGenerateDgmlFile Condition=" '$(_AndroidTrimmableTypemapTrimJavaCode)' == 'true' and '$(AndroidLinkTool)' != '' and '$(IlcGenerateDgmlFile)' == '' ">true</IlcGenerateDgmlFile>
     <_UseTrimmableNativeAotProguardConfiguration Condition=" '$(_UseTrimmableNativeAotProguardConfiguration)' == '' ">true</_UseTrimmableNativeAotProguardConfiguration>
+    <_TrimmableNativeAotProguardConfigurationInputsStamp>$(_AndroidStampDirectory)_GenerateTrimmableTypeMapProguardConfiguration.inputs</_TrimmableNativeAotProguardConfigurationInputsStamp>
     <_CompileToDalvikDependsOnTargets>$(_CompileToDalvikDependsOnTargets);_GenerateTrimmableTypeMapProguardConfiguration</_CompileToDalvikDependsOnTargets>
   </PropertyGroup>
 
@@ -67,27 +76,63 @@
       DependsOnTargets="_GenerateTrimmableTypeMap" />
 
   <Target Name="_CollectTrimmableNativeAotDgmlFiles"
-      Condition=" '$(PublishTrimmed)' == 'true' and '$(_ProguardProjectConfiguration)' != '' ">
+      Condition=" '$(_AndroidTrimmableTypemapTrimJavaCode)' == 'true' and '$(PublishTrimmed)' == 'true' and '$(_ProguardProjectConfiguration)' != '' ">
     <ItemGroup>
       <_TrimmableNativeAotRuntimeIdentifiers Remove="@(_TrimmableNativeAotRuntimeIdentifiers)" />
       <_TrimmableNativeAotDgmlFiles Remove="@(_TrimmableNativeAotDgmlFiles)" />
+      <_TrimmableNativeAotCodegenDgmlFiles Remove="@(_TrimmableNativeAotCodegenDgmlFiles)" />
       <_TrimmableNativeAotRuntimeIdentifiers Include="$(RuntimeIdentifier)" Condition=" '$(RuntimeIdentifier)' != '' " />
       <_TrimmableNativeAotRuntimeIdentifiers Include="$(RuntimeIdentifiers)" Condition=" '$(RuntimeIdentifier)' == '' and '$(RuntimeIdentifiers)' != '' " />
-      <!-- RuntimeIdentifier, RuntimeIdentifiers, and no-RID publishes place ILC DGML under different intermediate paths. -->
-      <_TrimmableNativeAotDgmlFiles Include="$(NativeIntermediateOutputPath)$(TargetName).scan.dgml.xml" Condition=" '@(_TrimmableNativeAotRuntimeIdentifiers)' == '' " />
-      <_TrimmableNativeAotDgmlFiles Include="$(NativeIntermediateOutputPath)$(TargetName).scan.dgml.xml" Condition=" '$(RuntimeIdentifier)' != '' " />
-      <_TrimmableNativeAotDgmlFiles Include="$(IntermediateOutputPath)%(_TrimmableNativeAotRuntimeIdentifiers.Identity)\native\$(TargetName).scan.dgml.xml" Condition=" '$(RuntimeIdentifier)' == '' and '@(_TrimmableNativeAotRuntimeIdentifiers)' != '' " />
+      <!-- ILC writes each *.scan.dgml.xml into the per-RID inner build's NativeIntermediateOutputPath
+           (i.e. '<inner IntermediateOutputPath>/native/'). This target runs in the OUTER build, whose
+           '$(IntermediateOutputPath)' may or may not already carry the RID segment:
+             * a single explicit '$(RuntimeIdentifier)' set early -> the SDK already appended the RID,
+               so the DGML is at '$(NativeIntermediateOutputPath)' (== '$(IntermediateOutputPath)native/');
+             * a '$(RuntimeIdentifiers)' list, or a RID assigned late (e.g. by _GetPrimaryCpuAbi) -> the
+               outer path has no RID, so the DGML is at '$(IntermediateOutputPath)<rid>/native/'.
+           Emit both candidate paths and keep only the one(s) ILC actually produced; this stays correct
+           for single-RID (either flavor), multi-RID, and no-RID publishes without having to guess which
+           output-path shape the SDK chose. -->
+      <_TrimmableNativeAotDgmlFiles Include="$(NativeIntermediateOutputPath)$(TargetName).scan.dgml.xml"
+          Condition=" Exists('$(NativeIntermediateOutputPath)$(TargetName).scan.dgml.xml') " />
+      <_TrimmableNativeAotDgmlFiles Include="$(IntermediateOutputPath)%(_TrimmableNativeAotRuntimeIdentifiers.Identity)\native\$(TargetName).scan.dgml.xml"
+          Condition=" '@(_TrimmableNativeAotRuntimeIdentifiers)' != '' and Exists('$(IntermediateOutputPath)%(_TrimmableNativeAotRuntimeIdentifiers.Identity)\native\$(TargetName).scan.dgml.xml') " />
+      <!-- ILC only emits the scan graph (*.scan.dgml.xml) when its scanner phase runs (optimized/Release
+           builds). Unoptimized builds - e.g. Debug NativeAOT - emit only the codegen graph
+           (*.codegen.dgml.xml), which carries the same "Type metadata: [...]" nodes. Collect it at the same
+           two candidate locations and fall back to it only when no scan graph was found, so the ACW keep
+           rules are still generated (the codegen graph is larger, hence preferring the scan graph). -->
+      <_TrimmableNativeAotCodegenDgmlFiles Include="$(NativeIntermediateOutputPath)$(TargetName).codegen.dgml.xml"
+          Condition=" Exists('$(NativeIntermediateOutputPath)$(TargetName).codegen.dgml.xml') " />
+      <_TrimmableNativeAotCodegenDgmlFiles Include="$(IntermediateOutputPath)%(_TrimmableNativeAotRuntimeIdentifiers.Identity)\native\$(TargetName).codegen.dgml.xml"
+          Condition=" '@(_TrimmableNativeAotRuntimeIdentifiers)' != '' and Exists('$(IntermediateOutputPath)%(_TrimmableNativeAotRuntimeIdentifiers.Identity)\native\$(TargetName).codegen.dgml.xml') " />
+      <_TrimmableNativeAotDgmlFiles Include="@(_TrimmableNativeAotCodegenDgmlFiles)"
+          Condition=" '@(_TrimmableNativeAotDgmlFiles->Count())' == '0' " />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="_WriteTrimmableNativeAotProguardConfigurationInputs"
+      Condition=" '$(PublishTrimmed)' == 'true' and '$(_ProguardProjectConfiguration)' != '' ">
+    <MakeDir Directories="$(_AndroidStampDirectory)" Condition=" !Exists('$(_AndroidStampDirectory)') " />
+    <WriteLinesToFile
+        File="$(_TrimmableNativeAotProguardConfigurationInputsStamp)"
+        Lines="$(_AndroidTrimmableTypemapTrimJavaCode)"
+        Overwrite="true"
+        WriteOnlyWhenDifferent="true" />
+    <ItemGroup>
+      <FileWrites Include="$(_TrimmableNativeAotProguardConfigurationInputsStamp)" />
     </ItemGroup>
   </Target>
 
   <Target Name="_GenerateTrimmableTypeMapProguardConfiguration"
-      DependsOnTargets="_CollectTrimmableNativeAotDgmlFiles"
+      DependsOnTargets="_WriteTrimmableNativeAotProguardConfigurationInputs;_CollectTrimmableNativeAotDgmlFiles"
       Condition=" '$(PublishTrimmed)' == 'true' and '$(_ProguardProjectConfiguration)' != '' "
-      Inputs="@(_TrimmableNativeAotDgmlFiles);$(IntermediateOutputPath)acw-map.txt"
+      Inputs="$(_TrimmableNativeAotProguardConfigurationInputsStamp);@(_TrimmableNativeAotDgmlFiles);$(IntermediateOutputPath)acw-map.txt"
       Outputs="$(_ProguardProjectConfiguration)">
     <GenerateNativeAotProguardConfiguration
         NativeAotDgmlFiles="@(_TrimmableNativeAotDgmlFiles)"
         AcwMapFile="$(IntermediateOutputPath)acw-map.txt"
+        TrimJavaCallableWrappers="$(_AndroidTrimmableTypemapTrimJavaCode)"
         OutputFile="$(_ProguardProjectConfiguration)" />
     <ItemGroup>
       <FileWrites Include="$(_ProguardProjectConfiguration)" />

@@ -44,6 +44,12 @@
          stays incremental while still reacting to post-trim JCW regeneration. -->
     <_TrimmableJavaSourceStamp Condition=" '$(_TrimmableJavaSourceStamp)' == '' and '$(_AndroidRuntime)' == 'CoreCLR' and '$(PublishTrimmed)' == 'true' ">$(_PostTrimTrimmableTypeMapJavaStamp)</_TrimmableJavaSourceStamp>
     <_TrimmableJavaSourceStamp Condition=" '$(_TrimmableJavaSourceStamp)' == '' ">$(_TrimmableTypeMapOutputStamp)</_TrimmableJavaSourceStamp>
+    <!-- On NativeAOT, ensure ILC's dynamic build properties (e.g. RuntimeIdentifier-derived
+         paths) are computed before the typemap is generated. -->
+    <_GenerateTrimmableTypeMapDependsOn Condition=" '$(_AndroidRuntime)' == 'NativeAOT' ">$(IlcDynamicBuildPropertyDependencies)</_GenerateTrimmableTypeMapDependsOn>
+    <!-- _GetLibraryImports populates @(ExtractedManifestDocuments) (the extracted library .aar
+         AndroidManifest.xml files) that the legacy manifest merger merges into the app manifest. -->
+    <_GenerateTrimmableTypeMapDependsOn>$(_GenerateTrimmableTypeMapDependsOn);_GetLibraryImports</_GenerateTrimmableTypeMapDependsOn>
     <!-- Max array rank for __ArrayMapRank{N} sentinel emission. Defaults to 3 when
          dynamic code is unavailable, so array creation uses the typemap path;
          defaults to 0 otherwise, where dynamic code can use Array.CreateInstance directly. -->
@@ -98,7 +104,7 @@
   <Target Name="_GenerateTrimmableTypeMap"
       Condition=" '$(_AndroidTypeMapImplementation)' == 'trimmable' and '$(DesignTimeBuild)' != 'true' and '@(ReferencePath->Count())' != '0' and '$(_OuterIntermediateOutputPath)' == '' "
       AfterTargets="CoreCompile"
-      DependsOnTargets="_GetLibraryImports"
+      DependsOnTargets="$(_GenerateTrimmableTypeMapDependsOn)"
       Inputs="@(ReferencePath);@(PrivateSdkAssemblies);@(FrameworkAssemblies);@(ExtractedManifestDocuments);$(IntermediateOutputPath)$(TargetFileName);$(_AndroidManifestAbs);$(_AndroidBuildPropertiesCache)"
       Outputs="$(_TrimmableTypeMapOutputStamp)">
 
@@ -375,6 +381,7 @@
         OutputDirectory="$(IntermediateOutputPath)android"
         TargetName="$(TargetName)"
         Environments="@(_EnvironmentFiles)"
+        AdditionalProviderSources="@(_AdditionalProviderSources)"
         EnableSGenConcurrent="$(AndroidEnableSGenConcurrent)" />
 
     <!-- Copy generated manifest to expected location -->
@@ -383,6 +390,15 @@
         SkipUnchangedFiles="true"
         Condition="Exists('$(_TypeMapBaseOutputDir)AndroidManifest.xml')" />
 
+    <!-- The manifestmerger.jar path runs _ManifestMerger to produce android\AndroidManifest.xml from the
+         generated manifest. The legacy merger has no equivalent step, so on the trimmable path (where the
+         merged manifest was already produced, placeholders included, by _GenerateTrimmableTypeMap) copy it
+         into place directly; otherwise _ReadAndroidManifest and downstream packaging cannot find it. -->
+    <Copy SourceFiles="$(_TypeMapBaseOutputDir)AndroidManifest.xml"
+        DestinationFiles="$(IntermediateOutputPath)android\AndroidManifest.xml"
+        SkipUnchangedFiles="true"
+        Condition=" '$(AndroidManifestMerger)' != 'manifestmerger.jar' and Exists('$(_TypeMapBaseOutputDir)AndroidManifest.xml') " />
+
     <!-- acw-map.txt is populated by _GenerateTrimmableTypeMap with real managed→Java mappings.
          If that target was skipped (e.g., no input assemblies), create an empty placeholder so
          downstream targets (_ConvertCustomView, _UpdateAndroidResgen) can evaluate their Inputs. -->
@@ -392,6 +408,8 @@
     <ItemGroup>
       <FileWrites Include="$(IntermediateOutputPath)android/src/net/dot/android/ApplicationRegistration.java" />
       <FileWrites Include="$(IntermediateOutputPath)AndroidManifest.xml" />
+      <FileWrites Include="$(IntermediateOutputPath)android\AndroidManifest.xml"
+          Condition=" '$(AndroidManifestMerger)' != 'manifestmerger.jar' " />
       <FileWrites Include="$(IntermediateOutputPath)acw-map.txt" />
     </ItemGroup>
 
@@ -418,4 +436,41 @@
       <FileWrites Include="@(_TypeMapAssemblySource)" />
     </ItemGroup>
   </Target>
+
+  <!--
+    Keep the resource designer assembly on the trimmable type map path.
+
+    The non-trimmable path (Microsoft.Android.Sdk.TypeMap.LlvmIr.targets) runs
+    PreTrimmingFixLegacyDesigner, which rewrites legacy resource field loads into designer
+    property-getter calls so the trimmer can drop unused designer members. The trimmable path
+    does not run that rewrite. More importantly, resource ids are resolved via reflection at
+    runtime (Android.Runtime.ResourceIdManager then ResourceDesignerAttribute then Type.GetType /
+    UpdateIdValues), which neither ILLink nor ILC can follow. If the designer assembly is left
+    trimmable it gets removed entirely, and accessing any resource id (e.g. from a reflection-only
+    code path) throws a TypeInitializationException wrapping
+    System.IO.FileNotFoundException: _Microsoft.Android.Resource.Designer at runtime.
+
+    Keep the whole _Microsoft.Android.Resource.Designer assembly. Two things are required on the
+    NativeAOT (ILC) path:
+      * ILC only loads the assemblies passed to it as references; the designer is a compile-time
+        reference but is NOT in @(IlcReference), so add it. Rooting an assembly ILC never loaded
+        fails hard with "Failed to load assembly '_Microsoft.Android.Resource.Designer'".
+      * Root it so ILC/ILLink keep it whole (TrimMode-based rooting can't be used here because
+        _AndroidComputeIlcCompileInputs clears @(_IlcManagedInputAssemblies)).
+
+    Drive both off @(ReferencePath) filtered to the designer: the item is empty when the designer
+    assembly was not generated (e.g. no resources / AndroidGenerateResourceDesigner=false), so we
+    never reference or root a non-existent assembly. @(IlcReference) is ignored by ILLink, so the
+    CoreCLR path just gets the root.
+  -->
+  <Target Name="_RootResourceDesignerForTrimmableTypeMap"
+      Condition=" '$(AndroidUseDesignerAssembly)' == 'True' and '$(PublishTrimmed)' == 'true' "
+      BeforeTargets="PrepareForILLink;WriteIlcRspFileForCompilation">
+    <ItemGroup>
+      <_ResourceDesignerReferenceToRoot Include="@(ReferencePath)"
+          Condition=" '%(Filename)' == '_Microsoft.Android.Resource.Designer' " />
+      <IlcReference Include="@(_ResourceDesignerReferenceToRoot->'%(FullPath)')" />
+      <TrimmerRootAssembly Include="@(_ResourceDesignerReferenceToRoot->'%(Filename)')" />
+    </ItemGroup>
+  </Target>
 </Project>
@@ -70,18 +70,8 @@ void Generate (NativeCodeGenStateObject codeGenState)
 			Xamarin.Android.Tasks.AndroidRuntime.CoreCLR => true,
 			_ => false,
 		};
-		string providerTemplateFile = isMonoVM ?
-			"MonoRuntimeProvider.Bundled.java" :
-			"NativeAotRuntimeProvider.java";
-		string providerTemplate = GetResource (providerTemplateFile);
 
-		foreach (var provider in AdditionalProviderSources) {
-			var contents = providerTemplate.Replace (isMonoVM ? "MonoRuntimeProvider" : "NativeAotRuntimeProvider", provider);
-			var real_provider = isMonoVM ?
-				Path.Combine (OutputDirectory, "src", "mono", provider + ".java") :
-				Path.Combine (OutputDirectory, "src", "net", "dot", "jni", "nativeaot", provider + ".java");
-			Files.CopyIfStringChanged (contents, real_provider);
-		}
+		WriteAdditionalRuntimeProviderSources (OutputDirectory, isMonoVM, AdditionalProviderSources);
 
 		// For NativeAOT, generate JavaInteropRuntime.java and NativeAotEnvironmentVars.java
 		if (androidRuntime == Xamarin.Android.Tasks.AndroidRuntime.NativeAOT) {
@@ -122,6 +112,29 @@ static string GetResource (string resource)
 			return reader.ReadToEnd ();
 	}
 
+	/// <summary>
+	/// Writes the additional per-process runtime provider Java sources (e.g. NativeAotRuntimeProvider_1.java)
+	/// by cloning the runtime provider template for each name. Shared between the legacy (ILLink) and
+	/// trimmable build paths so both emit the extra providers a multi-process app declares in its manifest.
+	/// </summary>
+	internal static void WriteAdditionalRuntimeProviderSources (string outputDirectory, bool isMonoVM, string [] additionalProviderSources)
+	{
+		if (additionalProviderSources.Length == 0) {
+			return;
+		}
+		string providerTemplateFile = isMonoVM ?
+			"MonoRuntimeProvider.Bundled.java" :
+			"NativeAotRuntimeProvider.java";
+		string providerTemplate = GetResource (providerTemplateFile);
+		foreach (var provider in additionalProviderSources) {
+			var contents = providerTemplate.Replace (isMonoVM ? "MonoRuntimeProvider" : "NativeAotRuntimeProvider", provider);
+			var realProvider = isMonoVM ?
+				Path.Combine (outputDirectory, "src", "mono", provider + ".java") :
+				Path.Combine (outputDirectory, "src", "net", "dot", "jni", "nativeaot", provider + ".java");
+			Files.CopyIfStringChanged (contents, realProvider);
+		}
+	}
+
 	void SaveResource (string resource, string filename, string destDir, Func<string, string> applyTemplate)
 	{
 		string template = GetResource (resource);

@@ -29,11 +29,19 @@ public sealed class GenerateNativeAotBootstrapSources : AndroidTask
 
 	public bool EnableSGenConcurrent { get; set; }
 
+	// Names of the extra per-process runtime providers (e.g. NativeAotRuntimeProvider_1) that the
+	// manifest declares for components with a non-default android:process; their Java sources must be
+	// generated too. On the legacy path GenerateAdditionalProviderSources writes these; the trimmable
+	// path has no such task, so the bootstrap step handles them here.
+	public string [] AdditionalProviderSources { get; set; } = [];
+
 	public override bool RunTask ()
 	{
 		GenerateAdditionalProviderSources.GenerateNativeAotBootstrapFiles (
 			Log, OutputDirectory, TargetName, Environments, EnableSGenConcurrent);
 
+		GenerateAdditionalProviderSources.WriteAdditionalRuntimeProviderSources (OutputDirectory, isMonoVM: false, AdditionalProviderSources);
+
 		return !Log.HasLoggedErrors;
 	}
 }