Fold typed-array attribute constraints into static definition emission

[jonathanvdc]

Goal

Typed-array attribute constraints should no longer have their own attribute-constraint emission kind or per-constraint generated assembly-format shim. Treat them like the other storage-backed attribute constraints: emit a static AttributeConstraintDefinition that points at a reusable runtime assembly format, and rely on the existing global::MLIR.ArrayAttr storage overlays for typed operation properties.

Background

src/MLIR.Generators/Prelude/Extensions/mlir/IR/CommonAttrConstraintsExtensions.td already describes TypedArrayAttrBase-style constraints as global::MLIR.ArrayAttr storage. The specific array constraints refine the public property type and storage conversion through ArrayAttrConstraintHelpers, for example:

• csharpStorageType = "global::MLIR.ArrayAttr"
• csharpReturnType = "global::System.Collections.Generic.IReadOnlyList<...>"
• csharpConvertFromStorage = "global::MLIR.Semantics.Attributes.Collections.ArrayAttrConstraintHelpers.GetItems(...)"
• csharpConstBuilderCall = "global::MLIR.Semantics.Attributes.Collections.ArrayAttrConstraintHelpers.Create(...)"

So the generated typed-array constraint classes are not needed as semantic storage. Today the remaining special case is only a generated assembly-format class like:

internal sealed class I32ArrayAttrConstraintAttributeValueAssemblyFormat
    : TypedArrayAttributeAssemblyFormat<int>
{
}

The TElement parameter is not used by TypedArrayAttributeAssemblyFormat<TElement> for parsing, binding, or printing: it parses an array literal, binds to ArrayAttr, and rebuilds from ArrayAttr.Value.

Proposed Change

1. Replace TypedArrayAttributeAssemblyFormat<TElement> with a non-generic reusable runtime format.

   Suggested shape:

   public sealed class TypedArrayAttributeAssemblyFormat : IAttributeAssemblyFormat
   {
       // same parse/bind/print behavior as the current generic base
   }

   Keep the existing behavior:

   • parse [ ... ] into ArrayAttributeValueSyntax
   • bind with ArrayAttrConstraintHelpers.BindFromSyntax(...)
   • print from reusable ArrayAttributeValueSyntax when available
   • otherwise print from ArrayAttr.Value

2. Make TypedArrayConstraintCodeStrategy use the normal static-definition path.

   It should provide an assembly format expression equivalent to:

   new global::MLIR.Dialects.Attributes.Collections.TypedArrayAttributeAssemblyFormat()

   This should make typed-array constraints look like dictionary/type/unit/elements constraints from the emitter's point of view.

3. Delete the typed-array-specific emission kind and emitter path.

   Remove:

   • AttributeConstraintEmissionKind.TypedArray
   • AttributeConstraintEmitter.EmitTypedArrayConstraint(...)
   • AttributeConstraintEmitter.GetTypedArrayElementTypeName(...)
   • generated per-constraint ...AssemblyFormat : TypedArrayAttributeAssemblyFormat<TElement> classes

4. Keep operation property typing and setter/getter behavior driven by AttrModel overlays.

   Do not regress the typed public surface for constraints such as:

   • I32ArrayAttr -> IReadOnlyList<int>
   • StrArrayAttr -> IReadOnlyList<string>
   • TypeArrayAttr -> IReadOnlyList<TypeReference>
   • DictArrayAttr -> IReadOnlyList<NamedAttributeCollection>

   These should continue to use ArrayAttrConstraintHelpers.GetItems(...) and ArrayAttrConstraintHelpers.Create(...) from the TableGen extensions.

Acceptance Criteria

• Typed-array constraints are emitted as ordinary static constraint-definition holders.
• No per-typed-array generated assembly format classes are emitted.
• No generated typed-array AttributeValue subclasses or helper Create/GetItems methods are emitted.
• The runtime has a single reusable typed-array/array attribute assembly format.
• Existing typed-array operation properties remain strongly typed through the csharpStorageType, csharpReturnType, csharpConvertFromStorage, and csharpConstBuilderCall overlays.
• Remove dead typed-array emission code from AttributeConstraintEmitter.

Suggested Validation

Run:

dotnet test tests/MLIR.Generators.Tests/MLIR.Generators.Tests.csproj -m:1
dotnet test tests/DialectTests/DialectTests.csproj -m:1
dotnet test tests/MLIR.Tests/MLIR.Tests.csproj -m:1
dotnet build samples/GeneratedDialectConsumer/GeneratedDialectConsumer.csproj -m:1

Strengthen TypedArrayAttrConstraintsAreGeneratedAsConstraintOnlyStaticClasses so it also asserts that typed-array constraints use the reusable runtime assembly format and do not emit per-constraint typed-array assembly-format classes.