Simplify nativeaot typeloader - #134843
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MichalStrehovsky merged 6 commits intoOct 2, 2026
Merged
MichalStrehovsky merged 6 commits into
MichalStrehovsky merged 6 commits into
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Remove obsolete loader state and lookup abstractions, reuse template layouts, and preserve compiler-emitted interface slots. Correct multidimensional array component-size replacement and add active regression coverage. Retain lazy-generics support and leave the shared Common TypeSystem unchanged. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 20d0d104-fdd3-458f-985d-ea71d12d0065
Use resolved base dictionaries instead of cached presence checks, remove unused MethodTable setters and metadata-loading fallbacks, inline invoke-map parsing, and omit the unused native-format writer source. Add coverage for empty and reused base dictionaries. Preserve lazy generics and defer GCDesc emission changes. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 20d0d104-fdd3-458f-985d-ea71d12d0065
Translate boxed element GC series directly into array descriptors, removing the intermediate bitmap and its scanning helpers. Extend MD-array GC layout coverage. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: c1b4a0f0-8f10-4475-9efb-ef1edbac54d6
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Tagging subscribers to this area: @agocke, @dotnet/ilc-contrib |
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/azp run runtime-nativeaot-outerloop |
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This was referenced Sep 29, 2026
The array GCDesc "val_serie" encoding stores per-series run (nptrs) and skip counts in HALF_SIZE_T fields, which are uint32 on 64-bit targets. Both encoders wrote these fields by casting through a signed short, which sign-extended values in [32768, 65535] into 0xFFFFxxxx. The GC then walked such arrays with a bogus ~4GB stride, dropping or corrupting element references (and crashing) for element types with two GC references separated by a 32KB-64KB non-pointer gap. Cast through unsigned types (ushort/uint) so the values zero-extend: * GCDescEncoder / ObjectDataBuilder (AOT compiler path): rename EmitHalfNaturalInt(short) to EmitHalfNaturalUInt(ushort). * EETypeCreator.CreateMdArrayGCDesc (runtime type loader path): use unsigned pointer and cast types. The 32-bit path is byte-identical (the field is exactly uint16 there). Adds a regression test to the NativeAOT UnitTests smoke test exercising both encoder paths with a compacting GC. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: badcb654-1848-4160-b6f8-c6fad59803d7
MichalStrehovsky
marked this pull request as ready for review
September 30, 2026 08:22
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/azp run runtime-nativeaot-outerloop |
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Azure Pipelines: Successfully started running 1 pipeline(s). |
The type loader was previously happy to construct MethodTable for e.g. `int&[]` (considering it a reference type element). Now it asserts.
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Copilot review overview
🟡 Changes recommended
The new GC and interface-map regressions do not yet deterministically cover all affected configurations.
Review effort: Balanced
Findings: 2
Open (2)
What changed in this PR
Simplifies NativeAOT type loading by deriving runtime layout data directly from canonical templates and fixes GC descriptor, interface-map, and generic hierarchy handling.
Changes:
- Removes redundant type-loader state and lookup abstractions.
- Reuses template layouts for vtables, interfaces, statics, and arrays.
- Adds regression coverage for dynamic generics and array GC layouts, with two test-quality gaps noted.
| File | Description |
|---|---|
src/tests/nativeaot/SmokeTests/UnitTests/MiscTests.cs |
Adds large-struct array GC regression. |
src/tests/nativeaot/SmokeTests/UnitTests/Generics.cs |
Tests hierarchy dictionaries and template array layouts. |
src/tests/nativeaot/SmokeTests/DynamicGenerics/interfaces.cs |
Extends collapsed-interface tests. |
src/tests/nativeaot/SmokeTests/DynamicGenerics/arrays.cs |
Expands dynamic multidimensional-array coverage. |
src/coreclr/tools/Common/Internal/Runtime/MappingTableFlags.cs |
Removes unused mapping flags. |
src/coreclr/tools/Common/Internal/Runtime/ITargetBinaryWriter.cs |
Makes half-width emission unsigned. |
src/coreclr/tools/Common/Internal/Runtime/GCDescEncoder.cs |
Prevents signed extension in GC descriptors. |
src/coreclr/tools/Common/Internal/NativeFormat/NativeFormat.cs |
Retires unused static-size entries. |
src/coreclr/tools/Common/Compiler/DependencyAnalysis/ObjectDataBuilder.cs |
Implements unsigned half-width emission. |
src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/VirtualMethodCallHelper.cs |
Simplifies base-slot calculation. |
src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ReflectionFieldMapNode.cs |
Removes obsolete canonical-entry flag. |
src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/NativeLayoutVertexNode.cs |
Stops emitting redundant static sizes. |
src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs |
Simplifies template vtable traversal. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/System.Private.TypeLoader.csproj |
Removes deleted source files. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/TypeSystem/TypeSystemContext.Runtime.cs |
Removes obsolete template accessor. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/TypeSystem/TypeDesc.Runtime.cs |
Requires templates consistently. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/TypeSystem/RuntimeMethodDesc.cs |
Inherits directly from MethodDesc. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/TypeSystem/NoMetadataMethodDesc.cs |
Deletes redundant abstraction. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/TypeSystem/MethodDesc.Runtime.cs |
Removes unused shareability cache. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/TypeSystem/InstantiatedMethod.Runtime.cs |
Removes redundant override. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/TypeSystem/DefType.Runtime.cs |
Deletes obsolete native-layout helpers. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeSystemExtensions.cs |
Removes unused generic-type helper. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderTypeSystemContext.cs |
Uses native-layout interfaces for unbuilt types. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.Metadata.cs |
Simplifies invoke-map lookup. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.GVMResolution.cs |
Removes redundant GVM conversions and lookup. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.FieldAccess.cs |
Removes unused module metadata. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.cs |
Specializes canonicalization and lookups. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.ConstructedGenericMethodsLookup.cs |
Replaces lookup class hierarchy with a struct. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeBuilderState.cs |
Removes computed layout caches. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeBuilder.cs |
Simplifies preparation and finishing. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TemplateLocator.cs |
Specializes template lookup to specific canon. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/NativeLayoutInterfacesAlgorithm.cs |
Reads compiler-emitted slot ordering directly. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/ModuleList.cs |
Simplifies immutable module lookup. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/MetadataNameExtensions.cs |
Removes unused metadata-name support. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/GenericDictionaryCell.cs |
Removes redundant dictionary-write hook. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/GenericDictionary.cs |
Writes created cells directly. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/EETypeCreator.cs |
Copies template layouts and rebuilds MD-array GC descriptors. |
src/coreclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/CanonicallyEquivalentEntryLocator.cs |
Uses specific-canonical helpers directly. |
src/coreclr/nativeaot/System.Private.Reflection.Execution/src/Internal/Reflection/Execution/ExecutionEnvironmentImplementation.MappingTables.cs |
Removes obsolete invoke checks and wrapper. |
src/coreclr/nativeaot/System.Private.CoreLib/src/System/Reflection/Runtime/General/TypeUnifier.cs |
Centralizes array element validation. |
src/coreclr/nativeaot/Common/src/Internal/Runtime/MethodTable.cs |
Removes unused setters and safely replaces component size. |
jkotas
reviewed
Oct 1, 2026
Pack mapping flags, remove redundant template validation, strengthen GC descriptor assertions, and retain original references in GC regression tests. Account for the post-decremented pointer in the descriptor size assertion. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 63b522df-2411-47e5-a588-7dfa448e93e0
jkotas
approved these changes
Oct 2, 2026
This was referenced Oct 2, 2026
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/ba-g failure is #67070. we have tons of issues about this, all in the Future milestone https://github.com/dotnet/runtime/issues?q=is%3Aissue+state%3Aopen+Multiple_From_Watched_To_Unwatched_Mac |
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Fixes 3 bugs.
Deletes 10+% of the runtime type loader code.