feat(codegen): support stable field naming and hot reload

[koenbeuk]

Problem

Adding serialized members can change generated serializer and copier fields. Existing generated instances have already run their constructors, so newly added dependencies must remain addressable and initialize on first use for Hot Reload to succeed.

Solution

• Give generated accessor fields stable names based on [Id] and generated codec/copier fields stable 64-bit type-identity names.
• Enable the Hot Reload generation shape explicitly with <OrleansHotReload>true</OrleansHotReload> so normal builds retain eager readonly initialization.
• Keep ICodecProvider available and lazily resolve dependencies added to existing serializer and copier instances.
• Preserve eager initialization for newly constructed instances and the normal optimized generation shape when the feature is disabled.
• Verify a real Roslyn metadata update against an existing generated copier, including a serialized member and concrete serializable type added in the same update.
• Document the supported additive workflow and serializer-manifest restart boundary.

Supported updates add strongly typed [Id] members to [GenerateSerializer] classes and records. A restart rebuilds serializer metadata after updates which introduce new types through polymorphic declarations or container element types. Grain interfaces and generated invokable types retain their existing compatibility requirements.

Microsoft Reviewers: Open in CodeFlow

[Copilot]

🔵 Needs a closer look

Pull request overview

Updates the Orleans code generator to produce Hot Reload–friendlier generated serializers/copiers by stabilizing generated field naming and (optionally) enabling lazy, self-healing resolution paths in Debug/HotReloadSafe builds.

Changes:

• Introduces stable generated field/accessor naming keyed by [Id] and by member type (with hash suffixes for collisions).
• Adds Hot Reload–safe codegen mode (defaulting to Debug optimization level, overridable via OrleansHotReload) which stores an ICodecProvider and uses lazy ??= initialization patterns for codecs/copiers/accessors.
• Adds targeted unit tests and refreshes source-generator snapshot baselines accordingly.

File summaries

File	Description
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestWithSuppressReferenceTrackingAttribute.verified.cs	Snapshot update for hot-reload-safe ctor/field shape.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestWithOmitDefaultMemberValuesAnnotation.verified.cs	Snapshot update for hot-reload-safe ctor/field shape.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestRecordsWithParameterIdAttributes.verified.cs	Snapshot update for stable accessor naming and lazy accessors/codecs.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestRecords.verified.cs	Snapshot update for stable type-keyed codec/copier field names and lazy init.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestGrainWithMultipleInterfaces.verified.cs	Snapshot update (formatting/line shifts) from generator changes.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestGrainWithDifferentKeyTypes.verified.cs	Snapshot update for codec/copier ctor signature changes and stored codec provider.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestGrainMethodAnnotatedWithResponseTimeout.verified.cs	Snapshot update (formatting/line shifts) from generator changes.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestGrainMethodAnnotatedWithInvokableBaseType.verified.cs	Snapshot update for codec/copier ctor signature changes and stored codec provider.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestGrainComplexGrain.verified.cs	Snapshot update for stable field naming (e.g., _copier_ComplexData) and codec-provider storage.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestGenericClassWithConstructorParameters.verified.cs	Snapshot update for type-keyed codec/copier fields and hot-reload-safe ??= access.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestGenericClass.verified.cs	Snapshot update for type-keyed codec/copier fields and hot-reload-safe ??= access.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestCompoundTypeAlias.verified.cs	Snapshot update for codec-provider storage in codec/copier.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassWithParameterizedConstructor.verified.cs	Snapshot update for codec/copier ctor signature changes and type-keyed fields.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassWithOptionalConstructorParameters.verified.cs	Snapshot update for stable accessor naming and lazy accessors.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassWithNoPublicConstructors.verified.cs	Snapshot update for codec/copier ctor signature changes and codec-provider storage.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassWithInterfaceConstructorParameter.verified.cs	Snapshot update for type-keyed codec/copier fields and hot-reload-safe ??= access.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassWithGenerateSerializerAnnotation.verified.cs	Snapshot update for type-keyed codec fields and codec-provider storage.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassWithGenerateMethodSerializersAnnotation.verified.cs	Snapshot update (formatting/line shifts) from generator changes.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassReferenceProperties.verified.cs	Snapshot update for stable accessor naming and lazy accessors.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassPrimitiveTypesUsingFullName.verified.cs	Snapshot update for type-keyed codec/copier fields and hot-reload-safe ??= access.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassPrimitiveTypes.verified.cs	Snapshot update for type-keyed codec/copier fields and hot-reload-safe ??= access.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassNestedTypes.verified.cs	Snapshot update for stable type-keyed codec/copier fields and lazy init.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestClassesWithGeneratedActivatorConstructorAnnotation.verified.cs	Snapshot update for codec-provider storage in codec/copier.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestBasicStruct.verified.cs	Snapshot update for codec-provider storage in value serializer.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestBasicGrain.verified.cs	Snapshot update for codec/copier ctor signature changes and codec-provider storage.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestBasicClassWithoutNamespace.verified.cs	Snapshot update for codec-provider storage in codec/copier.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestBasicClassWithInheritance.verified.cs	Snapshot update for codec-provider storage and stable generated field naming.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestBasicClassWithDifferentAccessModifiers.verified.cs	Snapshot update for codec-provider storage in codec/copier.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestBasicClassWithAnnotatedFields.verified.cs	Snapshot update for stable accessor naming and lazy accessors.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestBasicClass.verified.cs	Snapshot update for codec-provider storage in codec/copier.
test/Orleans.CodeGenerator.Tests/snapshots/OrleansSourceGeneratorTests.TestAlias.verified.cs	Snapshot update for codec-provider storage in value serializer.
test/Orleans.CodeGenerator.Tests/HotReloadCodegenTests.cs	Adds tests validating Hot Reload–safe shapes, lazy init behavior, and property override behavior.
test/Orleans.CodeGenerator.Tests/GeneratedFieldNamesTests.cs	Adds unit tests for stable accessor/type-keyed naming and collision handling.
src/Orleans.CodeGenerator/SyntaxGeneration/GeneratedFieldNames.cs	Adds stable field/accessor naming helpers (with collision hashing).
src/Orleans.CodeGenerator/SourceGeneratorOptionsParser.cs	Adds Orleans_HotReload option parsing and defaults HotReloadSafe based on optimization level.
src/Orleans.CodeGenerator/SerializerGenerator.cs	Implements hot-reload-safe serializer shape (codec provider storage, lazy ??= usage, stable naming).
src/Orleans.CodeGenerator/SerializableSourceOutputGenerator.cs	Wires compilation into options creation so optimization level can drive HotReloadSafe.
src/Orleans.CodeGenerator/ReferenceAssemblyDataProvider.cs	Wires compilation into options creation so optimization level can drive HotReloadSafe.
src/Orleans.CodeGenerator/ProxySourceOutputGenerator.cs	Wires compilation into options creation so optimization level can drive HotReloadSafe.
src/Orleans.CodeGenerator/Model/SerializableTypeDescription.cs	Declares serializable types as supporting hot-reload member addition.
src/Orleans.CodeGenerator/Model/ProxyMethodDescription.cs	Marks generated invokables as not supporting hot-reload member addition.
src/Orleans.CodeGenerator/Model/ISerializableTypeDescription.cs	Adds SupportsHotReloadMemberAddition contract for generators.
src/Orleans.CodeGenerator/Model/GeneratedInvokableDescription.cs	Marks generated invokables as not supporting hot-reload member addition.
src/Orleans.CodeGenerator/CopierGenerator.cs	Implements hot-reload-safe copier shape (codec provider storage, lazy ??= usage, stable naming).
src/Orleans.CodeGenerator/CodeGeneratorOptions.cs	Adds HotReloadSafe option controlling hot-reload-safe generation paths.
src/Orleans.CodeGenerator/build/Microsoft.Orleans.CodeGenerator.props	Exposes OrleansHotReload (via compiler-visible Orleans_HotReload) to the generator.

Review details

• Files reviewed: 43/46 changed files
• Comments generated: 1
• Review effort level: Lite

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[Copilot]

🔵 Needs a closer look

Review details

• Files reviewed: 43/46 changed files
• Comments generated: 0 new
• Review effort level: Lite

[Copilot]

🟡 Changes recommended

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Review details

• Files reviewed: 43/46 changed files
• Comments generated: 1
• Review effort level: Lite

[Copilot]

🔵 Needs a closer look

Review details

• Files reviewed: 43/46 changed files
• Comments generated: 0 new
• Review effort level: Lite

[Copilot]

🔵 Needs a closer look

Review details

• Files reviewed: 29/46 changed files
• Comments generated: 0 new
• Review effort level: Lite