Context

Base issue: #11225
Reference package path: System.Memory
Roslyn-based GenAPI location: https://github.com/dotnet/sdk/tree/main/src/GenAPI/

Usage:

/repos/source-build-reference-packages]# ./generate.sh --pkg microsoft.extensions.logging,2.1.1 --genapi-backend roslyn --dest /repos/source-build-reference-packages/src/referencePackages/roslyn/

Steps:

1. Generate SBRP package using SBRP generator with the roslyn-based backend
2. Compare cci-based <-> roslyn-based reference assemblies
3. Build the SBRP generated with the roslyn-based backend
4. Collect issues, their occurrence, create bugs for each.
5. Run the sdk/ApiCompat tool to compare generated API with original

How to compile project in SBRP

Use a docker or a VM and from root folder of source-build-reference-packages run:

/repos/source-build-reference-packages]# ./build.sh --projects ./build.sh --projects /repos/source-build-reference-packages/src/referencePackages/roslyn/system.memory/4.5.1/System.Memory.4.5.1.csproj

How to use the ApiCompat tool

sdk\artifacts\bin\Microsoft.DotNet.ApiCompat.Tool\Debug\net6.0> .\Microsoft.DotNet.ApiCompat.Tool.exe --strict-mode true --enable-rule-attributes-must-match true --enable-rule-cannot-change-parameter-name true --lref ... --rref ... -l ... -r ...

Found Issues:

• The SyntaxGenerator class does not generate default values for parameters of methods/constructors. #11734

Occurrence: 40+

• Add support for the implicit conversion operator generation to the SyntaxGenerator #11848

Occurrence: 11

• For a compile-time compat add synthesized private fields for a value type (struct) #11347

Occurrence: 7

• The DeclarationModifiers class does not properly handle readonly keyword for struct \s #11850

Occurrence: 5

+ public readonly partial struct Memory<T>
- public partial struct Memory<T>

• The SyntaxGenerator omits ref, readonly, new keywords for return types. #11881

Occurrence: 7+
The CCi-based output has ref T, Roslyn-based not

+ public ref T GetPinnableReference() { throw null; }
- public T GetPinnableReference() { throw null; }

+ public ref readonly T this[int index] { get { throw null; } }
- public T this[int index] { get { throw null; } }

• The SyntaxGenerator adds redundant static keyword to constant fields #11934

Occurrence: 1
error CS0504: The constant 'MaxPrecision' cannot be marked static

+ public const byte MaxPrecision = (byte)99;
- public static const byte MaxPrecision = 99;

• Add support for an explicit interface implementation method in SyntaxGenerator #11895

/// error CS0535: 'MemoryManager<T>' does not implement interface member 'IDisposable.Dispose()'
///     expects `void IDisposable.Dispose() { }`
public abstract partial class MemoryManager<T> : IMemoryOwner<T>, IDisposable, IPinnable
{
/// ...
        protected abstract void Dispose(bool disposing);
        public abstract Span<T> GetSpan();
/// ...
}

• The Roslyn-based GenAPI must substitute operator's implementation body throw null #11814

Occurrence: 5+

• The SyntaxGenerator omits accessibility level for accessors #11935

Occurrence: 3

public abstract partial class ReadOnlySequenceSegment<T>
{
/// ...
+     public System.ReadOnlyMemory<T> Memory { get { throw null; } protected set { } }
-     public System.ReadOnlyMemory<T> Memory { get { throw null; } set { } }
/// ...
}