[TrimmableTypeMap] Fix app initialization and startup

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.

[simonrozsival]

Summary

Fixes CoreCLR app startup with _AndroidTypeMapImplementation=trimmable while keeping the trimmable typemap path trim-safe and avoiding broad test roots.

• initialize and register trimmable typemap data without broad assembly rooting
• use the UTF-8 JniType overload for mono/android/Runtime
• preserve trimmable activation/proxy lookup without delegate-registration or reflection-activation fallbacks
• emit pregenerated UCO native registration with JniNativeMethod rows and direct ldftn function pointers
• package trimmable typemap assemblies for each CoreCLR ABI
• avoid duplicate debug typemap entries
• keep CoreCLRTrimmable runtime-test discovery working with narrow roots
• avoid pulling standalone external Java.Interop into Androidized runtime tests
• keep generator tests focused on metadata/exception-region shape instead of brittle emitted-IL call-token byte patterns

Follow-up PR for the non-trivial generated IL maxstack work: #11260.

Details

Runtime initialization

The runtime initialization path now uses the UTF-8 JniType constructor for mono/android/Runtime and registers trimmable typemap data early enough for CoreCLR startup.

Trimmable typemap runtime behavior

The trimmable typemap runtime path preserves activation and proxy lookup for registered peer types without falling back to reflection activation or delegate registration. The scanner also avoids treating JNI primitive keyword signatures as normal peer mappings.

TypeMap generation and packaging

The typemap generator now emits the raw metadata needed by the runtime path, including pregenerated UCO native registration data. CoreCLR trimmable packaging batches typemap assemblies per ABI so generated typemap DLLs are included for each target ABI.

Test roots and Java.Interop references

The CoreCLRTrimmable device-test project uses narrow visible roots plus explicit startup-hook roots instead of broad default RootMode=All roots. The Androidized Java.Interop test project compiles the GenericMarshaler helper directly so it binds against Android's platform Java.Interop, avoiding the standalone external Java.Interop project/reference in runtime tests.

Test exclusions and coverage

Runtime behavior is covered by the CoreCLRTrimmable device-test lane, including TrimmableTypeMapTypeManagerTests. Generator tests continue to validate metadata shape and exception-region structure without depending on exact emitted IL call-token byte sequences.

Validation

Note: do not pass -p:ExcludeCategories=... for the CoreCLRTrimmable RunTestApp command below. ExcludeCategories is appended inside Mono.Android.NET-Tests.csproj; setting it as a global property prevents the project from adding trimmable-specific exclusions such as NativeTypeMap:Export.

• MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • passed
• dotnet test tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests.csproj -v minimal
  • 430 passed, 0 failed
• ./dotnet-local.sh test bin/TestDebug/net10.0/Xamarin.Android.Build.Tests.dll --filter "FullyQualifiedName~TrimmableTypeMapBuildTests"
  • 5 passed, 0 failed
• ANDROID_SERIAL=R58Y30HZ65V MSBUILDDISABLENODEREUSE=1 ./dotnet-local.sh build tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj -t:RunTestApp -c Release -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -nr:false -tl:off -v:minimal
  • 887 total, 0 errors, 0 failures, 51 ignored
• Clean local .NET MAUI app run:
  • Installed local MAUI Android/Tizen workload records with manifest updates disabled so the repo-local SDK can build UseMaui projects.
  • Removed bin/ and obj/ from /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5.
  • ANDROID_SERIAL=R58Y30HZ65V ./dotnet-local.sh build /Users/simonrozsival/Projects/dotnet/playground/TestBlankMauiP5/TestBlankMauiP5.csproj -t:Run -f net11.0-android -c Release -p:TargetFrameworks=net11.0-android -p:UseMonoRuntime=false -p:_AndroidTypeMapImplementation=trimmable -p:AndroidPackageFormat=apk -p:RestoreConfigFile=/Users/simonrozsival/Projects/dotnet/android/NuGet.config -nr:false -tl:off -v:minimal
  • passed; com.companyname.testblankmauip5/crc64f2a221357d608c26.MainActivity was installed and focused in the foreground on R58Y30HZ65V.

[Copilot]

Pull request overview

This PR adjusts the trimmable typemap startup sequence and typemap metadata generation so that managed typemap data is available before AndroidRuntime construction, while native registrations that require JniRuntime.Current happen after the runtime is set.

Changes:

• Move trimmable typemap data initialization earlier in JNIEnvInit.Initialize() and register mono.android.Runtime.registerNatives(Class) after JniRuntime.SetCurrent().
• Update root typemap generation to emit TypeMapAssemblyTargetAttribute<T> with per-assembly anchors in aggregate mode and a shared anchor in merged mode, with new metadata-level tests.
• Refine scanning/model building and runtime lookup to treat GenerateJavaPeer=false peers as direct typemap entries, suppress inherited activation ctor resolution for them, and split “target type” vs “proxy type” lookup paths.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs	Adds a Java.Interop-style activation ctor to support activation-ctor scanning scenarios in tests.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/JavaPeerScannerTests.cs	Adds coverage ensuring GenerateJavaPeer=false peers do not inherit activation ctors.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Ensures non-generated peers without activation ctors produce no proxy types/associations.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/RootTypeMapAssemblyGeneratorTests.cs	Adds tests validating per-assembly vs shared anchor behavior by decoding attribute/type spec metadata.
src/Mono.Android/Microsoft.Android.Runtime/TrimmableTypeMap.cs	Splits native registration from initialization and adds separate caches for target-type and proxy lookup.
src/Mono.Android/Microsoft.Android.Runtime/SingleUniverseTypeMap.cs	Splits target-type enumeration from proxy-type enumeration and centralizes alias entry traversal.
src/Mono.Android/Microsoft.Android.Runtime/ITypeMapWithAliasing.cs	Updates interface to expose separate target/proxy enumeration methods.
src/Mono.Android/Microsoft.Android.Runtime/AggregateTypeMap.cs	Implements new interface shape across multiple universes.
src/Mono.Android/Android.Runtime/JNIEnvInit.cs	Adjusts initialization ordering and registers typemap native bridge after JniRuntime.Current exists.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Suppresses inherited activation ctor discovery for IsFromJniTypeSignature && DoNotGenerateAcw.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/RootTypeMapAssemblyGenerator.cs	Emits TypeMapAssemblyTargetAttribute<T> using per-assembly anchors in aggregate mode.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs	Extracts proxy-creation predicate to keep direct typemap entries for non-generated peers.

[simonrozsival]

⚠️ Needs Changes pending CI. I didn't find any blocking code correctness issues in the final diff, but the internal Xamarin.Android-PR check is still in progress, so this isn't merge-ready yet.

Issue counts: ❌ 0, ⚠️ 0, 💡 1. The trimmable runtime/device coverage and removal of brittle IL token assertions are good improvements.

[simonrozsival]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[github-actions]

✅ LGTM — well-structured initialization fix

Summary: This PR correctly reorders trimmable typemap initialization to fix CoreCLR app startup. The changes are architecturally sound, well-tested, and consistent with existing patterns.

Key observations

Initialization ordering (core fix): Splitting TypeMapLoader.Initialize() (data loading, before runtime) from TrimmableTypeMap.RegisterNativeMethods() (JNI registration, after runtime) is the right architectural fix. The JniType("mono/android/Runtime"u8) switch is now safe because the runtime's ClassLoader is available at the point of native registration.

UCO forwarder try/catch: The emitted WaitForBridgeProcessing → try { callback } catch { UnhandledException } pattern correctly mirrors the legacy JNINativeWrapper.g.cs wrappers. Unconditional catch (vs. the legacy exception filter) is correct for [UnmanagedCallersOnly] on CoreCLR.

Debug typemap duplicate fix (TypeMappingDebugNativeAssemblyGeneratorCLR.cs): Good bug fix — the old code was using entry.ManagedName/entry.AssemblyName when it should have been using managedEntry.* after resolving duplicates.

Per-assembly anchors (RootTypeMapAssemblyGenerator.cs): The split into EmitSharedUniverseAssemblyTargetAttributes vs EmitPerAssemblyUniverseAssemblyTargetAttributes correctly ensures TypeMapAssemblyTargetAttribute<T>'s anchor T matches what TypeMapping.GetOrCreate*TypeMapping<T>() expects at runtime.

MSBuild target extraction (_PrepareTrimmableTypeMapAssemblies): Correctly fixes the incremental build item-group problem — _GenerateJavaStubs can be skipped, which would leave assembly items empty for downstream targets.

Issues by severity

Severity	Count	Details
💡 Suggestion	1	MSBuild: use ->Count() instead of != '' for item empty checks (line 68, 76 in CoreCLR.targets)

CI Status

• license/cla: ✅ passed
• dotnet-android: ⚠️action_required (may need approval/re-trigger)
• Xamarin.Android-PR: not yet visible

Note: PR has merge conflicts (mergeable_state: dirty) — will need a rebase before merge.

Generated by Android PR Reviewer for issue #11252 · ● 15.3M

[jonathanpeppers]

Just one minor comment.

[jonathanpeppers]

Could this be:

<TrimmerRootAssemblyInclude="StartupHook"RootMode="All"Condition=" '$(StartupHookSupport)' == 'true' " />

[simonrozsival]

Yeah, this can be simplified. I will merge this PR now since it's green and open a follow-up PR.