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[TrimmableTypeMap] Add TypeMap assembly and JCW Java source generators#10808

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[TrimmableTypeMap] Add TypeMap assembly and JCW Java source generators#10808
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@simonrozsival simonrozsival commented Feb 12, 2026

Part of #10789
Stacked on #10805

Summary

This PR adds the TypeMap assembly generators and JCW Java source generators on top of the scanner from PR1. Together, these components form the complete pipeline: scan assemblies → build model → emit TypeMap assemblies + JCW .java files.

What's included

TypeMap Assembly Generator (TypeMapAssemblyEmitter + ModelBuilder)

  • Per-assembly TypeMap DLLs: Emits TypeMapAttribute<Java.Lang.Object> (2-arg unconditional, 3-arg trimmable) with proxy self-application pattern
  • Root TypeMap assembly (_Microsoft.Android.TypeMaps.dll): Central assembly with TypeMapAssemblyTargetAttribute<Java.Lang.Object> pointing to all per-assembly TypeMap DLLs
  • CreateInstance method: Generates correct IL for 5 activation patterns:
    1. No activation → return null
    2. Generic definition → throw new NotSupportedException
    3. Interface with invoker → newobj TInvoker::.ctor(IntPtr, JniHandleOwnership)
    4. Leaf with own ctor → newobj T::.ctor(IntPtr, JniHandleOwnership)
    5. Inherited ctor → GetUninitializedObject + castclass + call Base::.ctor
  • [UnmanagedCallersOnly] wrappers: UCO-attributed static methods wrapping each marshal method for RegisterNatives
  • [IgnoresAccessChecksTo]: Emitted for all cross-assembly references (including base ctor assemblies)
  • TypeMapAssociationAttribute: Emitted for alias types pointing to their canonical peer

JCW Java Source Generator (JcwJavaSourceGenerator)

  • Generates .java files with registerNatives calls in static {} blocks
  • Streaming TextWriter-based output (no intermediate string allocations)
  • Generates constructors, exported methods, and proper super() calls
  • Handles throws clauses from ThrownNames

Scanner Enrichment (fix-up for generators)

  • JniParameterInfo / JavaConstructorInfo — structured JNI parameter data for JCW constructor generation
  • ParseJniParameters / BuildJavaConstructors — enrichment methods on scanner output
  • JniSignatureHelper — ParseParameterTypeStrings, ParseReturnTypeString for JNI signature decomposition

Performance Optimizations

  • Emitter: 3 reusable BlobBuilder fields with Clear(), pre-computed UCO attribute blob, (string, string) tuple cache key for type refs
  • Scanner: Deduplicated GetString calls, tuple cache key for extendsJavaPeerCache, clean StringBuilder hex formatting

Tests

  • 254 tests total (scanner + generator)
  • Model builder tests: verify correct model construction for all peer categories
  • Pipeline tests: full scan → build → emit → load → verify roundtrip
  • CreateInstance IL verification for all 5 patterns
  • TypeMapAssociation and IgnoresAccessChecksTo coverage
  • JCW output structure and content tests

Follow-up

  • PR3 will wire these generators into the MSBuild targets

@simonrozsival simonrozsival mentioned this pull request Feb 12, 2026
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@simonrozsival simonrozsival force-pushed the dev/simonrozsival/trimmable-typemap-02-scanner branch 5 times, most recently from 627fef2 to 408d73d Compare February 13, 2026 09:25
@simonrozsival simonrozsival force-pushed the dev/simonrozsival/trimmable-typemap-03-generators branch 2 times, most recently from ba936c9 to 61ac7ed Compare February 13, 2026 10:35
@simonrozsival simonrozsival mentioned this pull request Feb 13, 2026
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@simonrozsival simonrozsival force-pushed the dev/simonrozsival/trimmable-typemap-03-generators branch 2 times, most recently from ddddd2f to 83a50be Compare February 13, 2026 11:22
@simonrozsival simonrozsival added Area: NativeAOT Issues that only occur when using NativeAOT. Area: CoreCLR Issues that only occur when using CoreCLR. copilot `copilot-cli` or other AIs were used to author this trimmable-type-map labels Feb 13, 2026
@simonrozsival simonrozsival force-pushed the dev/simonrozsival/trimmable-typemap-03-generators branch from 83a50be to 4e7d06c Compare February 13, 2026 17:12
@simonrozsival simonrozsival force-pushed the dev/simonrozsival/trimmable-typemap-02-scanner branch 8 times, most recently from 2388cf1 to e92938e Compare February 16, 2026 21:04
@simonrozsival
[TypeMap] Add JCW and TypeMap assembly generators with IR model
f525db4 
Implements generators for #10799:

- JcwJavaSourceGenerator: generates .java files for ACW types from JavaPeerInfo
- TypeMapModelBuilder: transforms JavaPeerInfo → TypeMapAssemblyModel (IR/AST)
- TypeMapAssemblyEmitter: mechanical SRM-based PE emitter from IR model
- TypeMapAssemblyGenerator: high-level API composing builder + emitter
- JniSignatureHelper: JNI signature parsing and CLR type encoding

Key design:
- 1 typemap assembly per input assembly for better caching
- IR model separates 'what to generate' from 'how to serialize to IL'
- Model builder tests are the primary unit tests (148 total, all passing)

Generated assemblies contain:
- [assembly: TypeMap] attributes per JNI type
- Proxy types (JavaPeerProxy subclasses) with CreateInstance, TargetType
- [UnmanagedCallersOnly] UCO wrappers for marshal methods/constructors
- RegisterNatives with function pointer registration
- IgnoresAccessChecksToAttribute for cross-assembly calls
@simonrozsival
Rename model types: drop IR/IL/AST terminology
b979fb2 
- TypeMapAssemblyModel → TypeMapAssemblyData
- TypeMapEntryModel → TypeMapAttributeData
- ProxyTypeModel → JavaPeerProxyData
- TypeRefModel → TypeRefData
- UcoMethodModel → UcoMethodData
- UcoConstructorModel → UcoConstructorData
- NativeRegistrationModel → NativeRegistrationData
- TypeMapModelBuilder → ModelBuilder
@simonrozsival
Add extensive fixture-based model builder and pipeline tests
13844f4 
30 new tests covering every test fixture type:
- MCW types: Object, Activity, Throwable, Exception, Service, Context, View, Button
- User ACW types: MainActivity, MyHelper, TouchHandler, CustomView, AbstractBase
- Interface types: IOnClickListener (with invoker dedup)
- Nested types: Outer$Inner, ICallback$Result proxy naming
- Multi-interface: ClickableView, MultiInterfaceView
- Export methods: ExportExample
- Generic types: GenericHolder
- Full pipeline tests: scan → model → emit → read back PE

Validates UCO wrapper signatures for all JNI types (bool, int, float,
long, double, object, array), constructor wrappers, native registrations,
TypeMap attribute counts, and proxy type names in emitted assemblies.

178 tests pass, 1 skipped.
@simonrozsival
Add 3-arg trimmable TypeMap attrs, alias detection, root assembly gen…
b6568a2 
…erator

Critical changes for TrimmableTypeMap:

- TypeMapAttributeData now supports 2-arg (unconditional) and 3-arg (trimmable):
  - 2-arg: ACW user types (Android can instantiate), essential runtime types
    (java/lang/Object, Throwable, Exception, etc.)
  - 3-arg: MCW bindings and interfaces — trimmer preserves proxy only if
    target type is referenced by the app
- Alias detection: when multiple .NET types share the same JNI name,
  they get indexed entries ("jni/name", "jni/name[1]", "jni/name[2]")
  with distinct proxy types
- RootTypeMapAssemblyGenerator: generates _Microsoft.Android.TypeMaps.dll
  with [assembly: TypeMapAssemblyTarget("name")] for each per-assembly
  typemap assembly

208 tests pass, 1 skipped.
@simonrozsival
Fix review findings: ctor JNI sig bug, deterministic ordering, test c…
540c1bf 
…overage

Review-driven fixes:

Bug fixes:
- Fix critical bug: constructor JNI signatures were hardcoded to "()V"
  in BuildNativeRegistrations. Now propagated from JavaConstructorInfo
  through UcoConstructorData.JniSignature to NativeRegistrationData.
- Fix non-deterministic alias ordering: replaced Dictionary with
  SortedDictionary, sort alias peers by ManagedTypeName.
- Fix Export attribute ThrownNames parsing: string[] was not being
  decoded from ImmutableArray<CustomAttributeTypedArgument<string>>.

Test improvements:
- Cache scanner results with static Lazy<> in all test classes
- Add parameterized constructor JNI signature test
- Add fixture-based CustomView constructor signature assertions
- Add PE blob validation tests (2-arg vs 3-arg TypeMap attributes)
- Add determinism test (same input → same output)
- Add Export with throws clause test fixture + JCW test
- Fix Build_CreatesOneEntryPerPeer for alphabetical ordering

Code quality:
- Add ECMA-335 comment explaining Type args as serialized strings
- Add comment explaining UCO constructor 2-param signature
- Fix doc comment: remove 'Intermediate representation' wording

215 tests pass, 1 skipped.
@simonrozsival
Fix review round 2: canonical string encoding, type ref caching, comp…
c0a9ace 
…uted IgnoresAccessChecksTo, edge-case tests
@simonrozsival
Fix review round 3: static ModelBuilder, Implementor/EventDispatcher …
5f19dde 
…exclusion, invoker filtering, managed-name proxy naming, root assembly cleanup

- Make ModelBuilder a static class with Build() method
- Add IsInvokerType() to filter invokers from alias grouping (get proxy, no TypeMap entry)
- Add IsImplementorOrEventDispatcher() to exclude from unconditional entries
- Change proxy naming from JNI-based to managed-name-based for uniqueness
- Remove unused stringRef/systemRuntimeInteropServicesRef from RootTypeMapAssemblyGenerator
- Add Implementor and EventDispatcher test fixtures
- Add tests for Implementor/EventDispatcher trimmability
- Add root assembly attribute blob value verification test
- All 225 tests pass
@simonrozsival
Fix review round 4: clear typeRefCache, extract constants, document n…
33d4dea 
…ame heuristics, add tests

- Clear _typeRefCache in Emit() alongside _asmRefCache to prevent stale handles on reuse
- Extract MonoAndroidPublicKeyToken and SystemRuntimeVersion as named constants
- Document name-based IsInvokerType/IsImplementorOrEventDispatcher heuristic limitations
- Fix stale doc comment on JavaPeerProxyData.TypeName
- Add FullPipeline_Mixed2ArgAnd3Arg_BothSurviveRoundTrip test
- Add FullPipeline_CustomView_UcoConstructorHasExactlyTwoParams PE-level test
- Add FullPipeline_GenericHolder_ProducesValidAssembly PE pipeline test
- Add edge case tests documenting name-based detection limitations
- Refactor ReadFirstTypeMapAttributeBlob into ReadAllTypeMapAttributeBlobs
- All 230 tests pass
@simonrozsival
Fix invoker handling, add dotnet version param, SuperArgumentsString …
f1ba60d 
…support

- Invoker types no longer get their own proxy types or TypeMap entries.
  They are only referenced as a TypeRef in the interface proxy's
  get_InvokerType property and CreateInstance method.
- Invoker detection now uses explicit relationship from [Register] third
  argument (InvokerTypeName) instead of name-based heuristic.
- Interface proxy CreateInstance creates the invoker type, not the
  interface itself.
- Added dotnetVersion parameter to TypeMapAssemblyEmitter,
  TypeMapAssemblyGenerator, and RootTypeMapAssemblyGenerator constructors
  (will be passed from $(DotNetTargetVersion) MSBuild property later).
- JCW generator now uses SuperArgumentsString for [Export] constructor
  super() calls instead of always forwarding all parameters.
- Documented PE-reading test helpers with clear comments explaining
  the approach and its limitations.
@simonrozsival
Change dotnetVersion parameter from int to Version
1a28d4c
@simonrozsival
Fix RootTypeMapAssemblyGenerator to use generic TypeMapAssemblyTarget…
0a6f267 
…Attribute<Java.Lang.Object>

Instead of defining a non-generic TypeMapAssemblyTargetAttribute in the
root assembly, reference the existing generic TypeMapAssemblyTargetAttribute`1
from System.Runtime.InteropServices and close it with Java.Lang.Object as
the type argument. This matches the runtime API:
https://learn.microsoft.com/en-us/dotnet/api/system.runtime.interopservices.typemapassemblytargetattribute-1
@simonrozsival
Refactor test sections into nested classes for better isolation
339549c 
Each '// ---- Section ----' comment block is now a nested class inside
the outer test class. This allows running individual test groups in
isolation and makes test failures easier to locate. Shared helpers
remain as static methods on the outer class.
@simonrozsival
Move Generator files to Microsoft.Android.Sdk.TrimmableTypeMap namespace
6a16b6a 
After rebasing onto the renamed base branch, Generator source and test
files landed under the old Microsoft.Android.Build.TypeMap paths. Move
them to the correct Microsoft.Android.Sdk.TrimmableTypeMap directories
and update all namespace references.
@simonrozsival
Fix CreateInstance to use proper activation patterns, add TypeMapAsso…
da5ae58 
…ciation, fix IgnoresAccessChecksTo

- Replace CreateManagedPeer with spec-compliant CreateInstance:
  - Leaf ctor: newobj T::.ctor(IntPtr, JniHandleOwnership)
  - Inherited ctor: GetUninitializedObject + call Base::.ctor
  - Interface: newobj TInvoker::.ctor(IntPtr, JniHandleOwnership)
  - Generic: throw new NotSupportedException()
- Add TypeMapAssociationAttribute emission for alias groups
- Include base ctor assembly in IgnoresAccessChecksTo
- Add ActivationCtorData and IsGenericDefinition to proxy model
- Add 5 new tests covering all CreateInstance paths, TypeMapAssociation,
  and IgnoresAccessChecksTo for inherited ctors
@simonrozsival
Simplify generator code
0b130ac 
- Make HasActivation a computed property (derived from ActivationCtor/InvokerType)
- Merge EmitSinglePeer into EmitPeers (handles both single and alias cases)
- Extract EmitCreateInstanceBody to deduplicate method signature across 5 paths
- Make BuildEntry's jniName parameter required (no longer optional)
@simonrozsival
Further simplify generator code
8dc353b 
- Remove ImplementsIAndroidCallableWrapper (was always == IsAcw)
- Collapse EmitTypeMapAttribute 2-arg/3-arg into shared blob writing
- Extract duplicated UCO signature lambda in EmitUcoMethod
- Simplify invoker filtering with LINQ
- Extract AddIfCrossAssembly helper for IgnoresAccessChecksTo
@simonrozsival
Remove redundant null checks in EmitCreateInstance
5bb64d6
@simonrozsival
Reduce allocations in TypeMapAssemblyEmitter
9c0bac5 
- Reuse 3 BlobBuilder instances (_sigBlob, _codeBlob, _attrBlob) instead
  of allocating a new one per method body, attribute, and member ref.
- Pre-compute the UCO attribute BlobHandle (always same 4 bytes).
- Use (string, string) tuple for type ref cache key instead of
  string interpolation — avoids allocation on every cache lookup.
@simonrozsival
Add generator model types and scanner enrichment for JCW/UCO generation
7420df4 
Add JniParameterInfo, JavaConstructorInfo, and additional properties to
MarshalMethodInfo and JavaPeerInfo that generators require (JniReturnType,
NativeCallbackName, Parameters, JavaConstructors, ManagedTypeNamespace,
ManagedTypeShortName). Extend JniSignatureHelper with raw type string
parsing. Enrich scanner output with these derived fields.
@simonrozsival
Fix UCO constructor wrappers to include full JNI parameter list
7088777 
The UCO constructor wrapper signature must match the JNI native method
signature (jnienv + self + constructor params) for correct ABI.
Previously it only accepted (IntPtr, IntPtr), causing a calling convention
mismatch when JNI dispatches constructors with parameters.

The body still calls ActivateInstance(self, typeof(T)) — the constructor
params are consumed but not forwarded, since peer activation uses the
(IntPtr, JniHandleOwnership) activation ctor, not the user constructor.
@simonrozsival simonrozsival force-pushed the dev/simonrozsival/trimmable-typemap-03-generators branch from 4e7d06c to 7088777 Compare February 16, 2026 22:25
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Area: CoreCLR Issues that only occur when using CoreCLR. Area: NativeAOT Issues that only occur when using NativeAOT. copilot `copilot-cli` or other AIs were used to author this trimmable-type-map

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